JP7031482B2 - Ejector refrigeration cycle and flow control valve - Google Patents

Description

The present invention relates to an ejector-type refrigeration cycle including an ejector and a flow control valve applied to the ejector-type refrigeration cycle.

Conventionally, an ejector type refrigeration cycle, which is a steam compression type refrigeration cycle equipped with an ejector, is known. In this type of ejector refrigeration cycle, the pressure of the intake refrigerant sucked into the compressor can be increased by the pressurizing action of the diffuser portion of the ejector. As a result, in the ejector type refrigeration cycle, the power consumption of the compressor can be reduced and the coefficient of performance (COP) of the cycle can be improved.

For example, Patent Document 1 discloses an ejector-type refrigeration cycle that is applied to an air conditioner and cools blown air blown to an air-conditioned space.

More specifically, the ejector type refrigeration cycle of Patent Document 1 includes a branch portion for branching the flow of the high pressure refrigerant flowing out from the radiator, and a suction side evaporator for evaporating the low pressure refrigerant to cool the blown air. There is. Then, one of the refrigerants branched at the branch portion flows into the nozzle portion of the ejector, and the other refrigerant branched at the branch portion is decompressed by the suction side decompression unit and flows into the suction side evaporator. Further, the cycle configuration is such that the refrigerant flowing out from the suction side evaporator is sucked from the refrigerant suction port of the ejector.

Further, in Patent Document 1, as a suction side decompression unit, a temperature type expansion valve that adjusts the throttle opening so that the superheat degree of the refrigerant on the outlet side of the suction side evaporator approaches a predetermined standard superheat degree is adopted. Examples are also disclosed.

Japanese Patent No. 5217121

By the way, as in Patent Document 1, by adjusting the throttle opening of the suction side decompression unit, the refrigerant sucked from the refrigerant suction port of the ejector can be surely used as a gas phase refrigerant having a degree of superheat. According to this, it is possible to suppress an unnecessary increase in the flow rate (mass flow rate) of the refrigerant sucked from the refrigerant suction port, and to suppress a decrease in the amount of boosting in the diffuser portion. That is, it is possible to suppress a decrease in COP of the cycle.

However, during low load operation, the flow rate of the refrigerant flowing into the suction side evaporator decreases, so the temperature distribution of the blown air cooled by the suction side evaporator may expand. .. That is, even if the throttle opening of the suction side decompression portion is adjusted so that the superheat degree of the refrigerant on the outlet side of the suction side evaporator approaches a predetermined standard superheat degree as in Patent Document 1, the load of the cycle fluctuates. Therefore, the flow rate of the refrigerant flowing into the suction side evaporator cannot be adjusted appropriately.

In view of the above points, it is an object of the present invention to provide an ejector type refrigerating cycle in which the flow rate of the refrigerant flowing into the suction side evaporator can be appropriately adjusted.

Another object of the present invention is to provide a flow rate adjusting valve capable of appropriately adjusting the flow rate of the refrigerant flowing into the suction side evaporator when applied to the ejector type refrigeration cycle.

In order to achieve the above object, the invention according to claim 1 is from a compressor (11) that compresses and discharges the refrigerant, a radiator (12) that dissipates the refrigerant discharged from the compressor, and a radiator. The refrigerant is sucked from the refrigerant suction port (14c) by the suction action of the jet refrigerant jetted from the nozzle portion (14a) that depressurizes the outflowing refrigerant, and the mixed refrigerant of the jet refrigerant and the suction refrigerant sucked from the refrigerant suction port is sucked. An ejector (14) for boosting the pressure, a suction side decompression unit (15) for depressurizing the refrigerant, and a suction side evaporator (19) for evaporating the decompressed refrigerant at the suction side decompression unit and flowing it out to the refrigerant suction port side. A bypass passage (16) that guides the refrigerant on the inlet side of the suction side decompression section to the inlet side of the suction side evaporator by bypassing the suction side decompression section, and a variable throttle mechanism that adjusts the flow rate of the refrigerant flowing through the bypass passage. With the part (17)
The suction side decompression unit changes the throttle opening so that the superheat degree (SH1) of the refrigerant on the outlet side of the suction side evaporator approaches a predetermined standard superheat degree (KSH1).
The variable throttle mechanism unit has a function of opening and closing the bypass passage, and opens the bypass passage when the flow rate (Ge1) of the refrigerant flowing out from the suction side decompression unit is equal to or less than a predetermined reference flow rate (KGe1). It is an ejector type refrigeration cycle.

According to this, the variable throttle mechanism unit (17) is bypassed under operating conditions where the flow rate (Ge1) of the refrigerant flowing out from the suction side decompression unit (15) is larger than the reference flow rate (KGe1) as in normal operation. Close the passage (16). As a result, the refrigerant decompressed by the suction side decompression unit (15) can flow into the suction side evaporator (19).

Therefore, under operating conditions where the flow rate of the refrigerant flowing into the suction side evaporator (19) is relatively large, the suction side decompression unit (15) changes the throttle opening degree to change the throttle opening, so that the outlet of the suction side evaporator (19). The flow rate of the refrigerant flowing into the suction side evaporator (19) can be appropriately adjusted so that the degree of superheat of the side refrigerant approaches the reference degree of superheat.

On the other hand, when the flow rate (Ge1) of the refrigerant flowing out from the suction side decompression unit (15) is equal to or less than the reference flow rate (KGe1) as in low load operation, the variable throttle mechanism unit (17) is bypassed. Open the passage (16). As a result, the refrigerant on the inlet side of the suction side decompression unit (15) can flow into the suction side evaporator (19) via the bypass passage (16).

Therefore, under operating conditions where the flow rate of the refrigerant flowing into the suction side evaporator (19) is relatively small, even if the suction side decompression unit (15) reduces the throttle opening, it passes through the bypass passage (16). The refrigerant can be reliably flowed into the suction side evaporator (19). As a result, it is possible to prevent the flow rate of the refrigerant flowing into the suction side evaporator (19) from becoming insufficient.

That is, according to the first aspect of the present invention, it is possible to provide an ejector type refrigerating cycle in which the flow rate of the refrigerant flowing into the suction side evaporator (19) can be appropriately adjusted according to the load fluctuation of the cycle. ..

The invention according to claim 4 is a compressor (11) that compresses and discharges the refrigerant, a radiator (12) that dissipates the refrigerant discharged from the compressor, and decompresses the refrigerant that has flowed out of the radiator. The ejector (14) sucks the refrigerant from the refrigerant suction port (14c) by the suction action of the injection refrigerant injected from the nozzle portion (14a), and boosts the pressure of the mixed refrigerant of the injection refrigerant and the suction refrigerant sucked from the refrigerant suction port. ), The suction side decompression unit (15) that decompresses the refrigerant, the suction side evaporator (19) that evaporates the decompressed refrigerant in the suction side decompression unit and discharges it to the refrigerant suction port side, and the suction side decompression unit. A bypass passage (16) that bypasses the suction side decompression section and guides the refrigerant on the inlet side to the inlet side of the suction side evaporator is provided.
The suction-side decompression section is in accordance with the encapsulation space (52c) in which the temperature-sensitive medium whose pressure changes with the temperature change of the refrigerant on the outlet side of the suction-side evaporator is enclosed, and the pressure of the temperature-sensitive medium in the encapsulation space. It has a throttle valve (51) that is displaced, and changes the throttle opening so that the superheat degree (SH1) of the refrigerant on the outlet side of the suction side evaporator approaches a predetermined reference superheat degree (KSH1).
The value obtained by subtracting the saturation pressure of the temperature-sensitive medium at the predetermined reference medium temperature from the outlet side pressure, which is the pressure of the refrigerant flowing out from the suction side evaporator, is defined as the valve opening set pressure (Y), and is defined as the valve opening set pressure (Y). When the ratio (Apt / Ax) of the minimum passage cross-sectional area (Apt) of the bypass passage to the maximum passage cross-sectional area (Aex) is defined as the area ratio X,
-170X + 3 ≧ Y
and,
Y ≧ -350X-9
It is an ejector type refrigeration cycle.

According to this, both the refrigerant decompressed by the suction side decompression unit (15) and the refrigerant that has passed through the bypass passage (16) can flow into the suction side evaporator (19).

Then, under operating conditions where the flow rate of the refrigerant flowing into the suction side evaporator (19) is relatively large as in normal operation, the suction side decompression unit (15) increases the throttle opening. Therefore, the ratio of the flow rate of the refrigerant flowing into the suction side evaporator (19) through the suction side decompression unit (15) increases from the flow rate of the refrigerant flowing into the suction side evaporator (19).

Therefore, under operating conditions where the flow rate of the refrigerant flowing into the suction side evaporator (19) is relatively large, the suction side decompression unit (15) changes the throttle opening degree to change the throttle opening, so that the outlet of the suction side evaporator (19). The flow rate of the refrigerant flowing into the suction side evaporator (19) can be appropriately adjusted so that the degree of superheat of the side refrigerant approaches the reference degree of superheat.

On the other hand, under operating conditions where the flow rate of the refrigerant flowing into the suction side evaporator (19) is relatively small, such as during low load operation, the suction side decompression unit (15) reduces the throttle opening. Therefore, the ratio of the flow rate of the refrigerant passing through the bypass passage (16) to the flow rate of the refrigerant flowing into the suction side evaporator (19) increases.

Therefore, under operating conditions where the flow rate of the refrigerant flowing into the suction side evaporator (19) is relatively small, even if the suction side decompression unit (15) reduces the throttle opening, it passes through the bypass passage (16). The refrigerant can be reliably flowed into the suction side evaporator (19). As a result, it is possible to prevent the flow rate of the refrigerant flowing into the suction side evaporator (19) from becoming insufficient.

That is, according to the invention of claim 4, it is possible to provide an ejector type refrigerating cycle in which the flow rate of the refrigerant flowing into the suction side evaporator (19) can be appropriately adjusted according to the load fluctuation of the cycle. ..

Further, the invention according to claim 6 sucks the refrigerant from the refrigerant suction port (14c) by the suction action of the injection refrigerant injected from the nozzle portion (14a) for reducing the pressure of the refrigerant, and sucks from the injection refrigerant and the refrigerant suction port. It is applied to an ejector type refrigeration cycle (10, 10a) having an ejector (14) for boosting the pressure of the mixed refrigerant with the suctioned refrigerant and a suction side evaporator (19) for evaporating the refrigerant and flowing it out to the refrigerant suction port side. It is a flow control valve
The suction side decompression section (15) that changes the throttle opening so that the superheat degree (SH1) of the refrigerant on the outlet side of the suction side evaporator approaches the predetermined standard superheat degree (KSH1), and the inlet of the suction side decompression section. A bypass passage (16) that bypasses the suction side decompression section and guides the side refrigerant to the outlet side of the suction side decompression section, and a variable throttle mechanism section (17) that adjusts the flow rate of the refrigerant flowing through the bypass passage. Prepare,
The refrigerant inlet side of the suction side evaporator is connected to the evaporator side outlet (21b) that discharges the decompressed refrigerant at the suction side decompression unit.
The variable throttle mechanism has a function of opening and closing the bypass passage, and the flow rate (Ge1) of the refrigerant flowing out from the suction side decompression unit to the refrigerant inlet side of the suction side evaporator is equal to or less than a predetermined reference flow rate (KGe1). It is a flow control valve that opens the bypass passage while the engine is running.

According to this, the flow rate (Ge1) of the refrigerant flowing out from the suction side decompression unit (15) in the applied ejector type refrigeration cycle (10, 10a) becomes larger than the reference flow rate (KGe1) as in the normal operation. When the condition is met, the variable throttle mechanism portion (17) closes the bypass passage (16). As a result, the refrigerant decompressed by the suction side decompression unit (15) can be discharged to the suction side evaporator (19) side.

Therefore, when the applied ejector type refrigerating cycle (10, 10a) is in an operating condition for flowing a relatively large amount of refrigerant into the suction side evaporator (19), the suction side decompression unit (15) By changing the throttle opening, the flow rate of the refrigerant flowing into the suction side evaporator (19) is appropriately adjusted so that the superheat degree of the refrigerant on the outlet side of the suction side evaporator (19) approaches the reference superheat degree. Can be adjusted.

On the other hand, under the operating condition that the flow rate (Ge1) of the refrigerant flowing out from the suction side decompression unit (15) is equal to or less than the reference flow rate (KGe1) as in the low load operation of the applied ejector type refrigeration cycle (10, 10a). When it is, the variable throttle mechanism portion (17) opens the bypass passage (16). As a result, the refrigerant on the inlet side of the suction side decompression unit (15) can be discharged to the suction side evaporator (19) side through the bypass passage (16).

Therefore, when the applied ejector type refrigeration cycle (10, 10a) is under the operating condition for flowing the refrigerant having a relatively small flow rate into the suction side evaporator (19), the suction side decompression unit (15) is used. Even if the throttle opening is reduced, the refrigerant that has passed through the bypass passage (16) can be reliably flowed into the suction side evaporator (19). As a result, it is possible to prevent the flow rate of the refrigerant flowing into the suction side evaporator (19) from becoming insufficient.

That is, according to the invention of claim 6, when applied to the ejector type refrigeration cycle (10, 10a), the flow rate of the refrigerant flowing into the suction side evaporator (19) according to the load fluctuation of the cycle. A flow rate control valve that can be appropriately adjusted can be provided.

Further, according to the ninth aspect of the present invention, the refrigerant is sucked from the refrigerant suction port (14c) by the suction action of the injection refrigerant injected from the nozzle portion (14a) for reducing the pressure of the refrigerant, and is sucked from the injection refrigerant and the refrigerant suction port. It is applied to an ejector type refrigerating cycle (10, 10a) having an ejector (14) for boosting the pressure of the mixed refrigerant with the suctioned refrigerant and a suction side evaporator (19) for evaporating the refrigerant and flowing it out to the refrigerant suction port side. It is a flow control valve
The suction side decompression section (15) that changes the throttle opening so that the superheat degree (SH1) of the refrigerant on the outlet side of the suction side evaporator approaches the predetermined standard superheat degree (KSH1), and the inlet of the suction side decompression section. A bypass passage (16) that bypasses the suction side decompression section and guides the side refrigerant to the outlet side of the suction side decompression section is provided.
The suction-side decompression unit is an enclosed space (52c) in which a temperature-sensitive medium whose pressure changes with the temperature change of the refrigerant on the outlet side of the suction-side evaporator is enclosed, and a throttle valve that is displaced according to the pressure of the temperature-sensitive medium. The refrigerant inlet side of the suction side evaporator is connected to the evaporator side outlet (21b) having (51) and causing the decompressed refrigerant to flow out at the suction side decompression section.
The value obtained by subtracting the saturation pressure of the temperature-sensitive medium at the predetermined reference medium temperature from the outlet side pressure, which is the pressure of the refrigerant flowing out from the suction side evaporator, is defined as the valve opening set pressure (Y), and is defined as the valve opening set pressure (Y). When the ratio (Apt / Ax) of the minimum passage cross-sectional area (Apt) of the bypass passage to the maximum passage cross-sectional area (Aex) is defined as the area ratio X,
-170X + 3 ≧ Y
and,
Y ≧ -350X-9
It is a flow rate control valve.

According to this, both the refrigerant decompressed by the suction side decompression unit (15) and the refrigerant that has passed through the bypass passage (16) can be discharged to the refrigerant inlet side of the suction side evaporator (19).

Then, when the applied ejector type refrigerating cycle (10, 10a) is in an operating condition for flowing a relatively large flow rate of the refrigerant into the suction side evaporator (19) as in normal operation, suction is performed. The side decompression unit (15) increases the throttle opening. Therefore, the ratio of the flow rate of the refrigerant flowing out to the refrigerant inlet side of the suction side evaporator (19) via the suction side decompression unit (15) is the ratio of the flow rate of the refrigerant flowing out to the suction side evaporator (19) side. To increase.

Therefore, when the applied ejector type refrigerating cycle (10, 10a) is in an operating condition for flowing a relatively large amount of refrigerant into the suction side evaporator (19), the suction side decompression unit (15). ) Changes the throttle opening, so that the flow rate of the refrigerant flowing into the suction side evaporator (19) is appropriate so that the degree of superheat of the refrigerant on the outlet side of the suction side evaporator (19) approaches the reference superheat degree. Can be adjusted to.

On the other hand, the operating condition in which the applied ejector type refrigeration cycle (10, 10a) causes the refrigerant having a relatively small flow rate to flow from the suction side decompression unit (15) to the suction side evaporator (19) as in the case of low load operation. When it is, the suction side decompression unit (15) reduces the throttle opening. Therefore, the ratio of the flow rate of the refrigerant passing through the bypass passage (16) to the flow rate of the refrigerant flowing out to the suction side evaporator (19) side increases.

Therefore, when the applied ejector type refrigeration cycle (10, 10a) is under the operating condition for flowing the refrigerant having a relatively small flow rate into the suction side evaporator (19), the suction side decompression unit (15) Even if the throttle opening is reduced, the refrigerant that has passed through the bypass passage (16) can be reliably flowed into the suction side evaporator (19). As a result, it is possible to prevent the flow rate of the refrigerant flowing into the suction side evaporator (19) from becoming insufficient.

That is, according to the invention of claim 9, when applied to the ejector type refrigeration cycle (10, 10a), the flow rate of the refrigerant flowing into the suction side evaporator (19) according to the load fluctuation of the cycle. A flow rate control valve that can be appropriately adjusted can be provided.

It should be noted that the reference numerals in parentheses of each means described in this column and the scope of claims are examples showing the correspondence with the specific means described in the embodiments described later.

It is an overall block diagram of the ejector type refrigeration cycle of 1st Embodiment. It is a schematic cross-sectional view when the flow rate control valve of 1st Embodiment is in a fully closed state of a bypass passage. It is a schematic cross-sectional view when the flow rate control valve of 1st Embodiment is in a throttle state of a bypass passage. It is a schematic cross-sectional view when the flow rate control valve of 1st Embodiment is in a state of a bypass passage fully opened. It is a schematic cross-sectional view when the flow rate control valve of the 2nd Embodiment is in a state of a bypass passage fully opened. It is a schematic cross-sectional view when the flow rate control valve of the 3rd Embodiment is in the bypass passage fully open state. It is a schematic cross-sectional view of the flow rate control valve of 4th Embodiment. It is explanatory drawing for demonstrating the measuring method of the valve opening set pressure of 4th Embodiment. It is a graph which shows the relationship between the area ratio of 4th Embodiment, and the valve opening set pressure. It is a schematic cross-sectional view of the flow rate control valve of the modification of 4th Embodiment. It is an overall block diagram of the ejector type refrigeration cycle of 5th Embodiment. It is an overall block diagram of the ejector type refrigeration cycle of the sixth embodiment. It is an overall block diagram of the ejector type refrigeration cycle of 7th Embodiment.

(First Embodiment)
The first embodiment of the present invention will be described with reference to FIGS. 1 to 4. The ejector type refrigeration cycle 10 of the present embodiment is applied to a vehicle air conditioner, and fulfills a function of cooling the blown air blown into the vehicle interior, which is a space to be air-conditioned. Therefore, the cooling target fluid of the ejector type refrigeration cycle 10 is blown air.

The ejector type refrigeration cycle 10 employs an HFO-based refrigerant (specifically, R1234yf) as a refrigerant, and constitutes a subcritical refrigeration cycle in which the high-pressure side refrigerant pressure of the cycle does not exceed the critical pressure of the refrigerant. Further, the refrigerant contains refrigerating machine oil for lubricating the compressor 11. In addition, a part of the refrigerating machine oil circulates in the cycle together with the refrigerant.

In the ejector type refrigeration cycle 10 shown in the overall configuration diagram of FIG. 1, the compressor 11 sucks in the refrigerant, compresses it, and discharges it. More specifically, the compressor 11 of the present embodiment is an electric compressor configured by accommodating a fixed-capacity compression mechanism and an electric motor for driving the compression mechanism in one housing.

As the compression mechanism, various compression mechanisms such as a scroll type compression mechanism and a vane type compression mechanism can be adopted. Further, the electric motor is one in which the rotation speed (that is, the refrigerant discharge capacity) is controlled by the control signal output from the air conditioning control device 40, and any type of AC motor or DC motor may be adopted. good.

The refrigerant inlet side of the radiator 12 is connected to the discharge port of the compressor 11. The radiator 12 is a heat exchanger for condensation that exchanges heat between the high-pressure refrigerant discharged from the compressor 11 and the outside air (outside air) blown by the cooling fan 12a to dissipate the high-pressure refrigerant and condense it. The cooling fan 12a is an electric blower whose rotation speed (blower air amount) is controlled by a control voltage output from the air conditioning control device 40.

The inlet side of the branch portion 13 is connected to the refrigerant outlet of the radiator 12. The branch portion 13 branches the flow of the refrigerant flowing out of the radiator 12. The branch portion 13 has a three-way joint structure having three refrigerant inflow ports communicating with each other, and one of the three refrigerant inflow ports is used as a refrigerant inlet and the other two are used as a refrigerant outlets. ..

The inlet side of the nozzle portion 14a of the ejector 14 is connected to one of the refrigerant outlets of the branch portion 13. The refrigerant inlet 21a side formed in the body portion 21 of the flow rate adjusting valve 20 is connected to the other refrigerant outlet of the branch portion 13.

The ejector 14 has a nozzle portion 14a that decompresses and injects the refrigerant flowing out of the radiator 12, and functions as a refrigerant decompression portion. Further, the ejector 14 functions as a refrigerant circulation unit that sucks and circulates the refrigerant from the outside by the suction action of the injection refrigerant injected from the refrigerant injection port of the nozzle unit 14a.

In addition to this, the ejector 14 converts the kinetic energy of the mixed refrigerant of the injected refrigerant injected from the nozzle portion 14a and the suction refrigerant sucked from the refrigerant suction port 14c into pressure energy, and energy conversion for boosting the mixed refrigerant. It functions as a department.

More specifically, the ejector 14 has a nozzle portion 14a and a body portion 14b. The nozzle portion 14a is made of a substantially cylindrical metal (stainless steel alloy in this embodiment) or the like that gradually tapers in the flow direction of the refrigerant. The nozzle portion 14a is used to reduce the pressure of the refrigerant isotropically in the refrigerant passage formed inside.

In the refrigerant passage formed inside the nozzle portion 14a, there is a throat portion that minimizes the passage cross-sectional area, and a divergent portion in which the passage cross-sectional area gradually expands toward the refrigerant injection port that injects the refrigerant from the throat portion. Is formed. That is, the nozzle portion 14a of the present embodiment is configured as a Laval nozzle.

Further, in the present embodiment, the nozzle portion 14a is set so that the flow velocity of the injected refrigerant injected from the refrigerant injection port during the normal operation of the cycle is equal to or higher than the speed of sound. Of course, the nozzle portion 14a may be configured with a tapered nozzle.

The body portion 14b is made of a substantially cylindrical metal (aluminum in this embodiment). The body portion 14b functions as a fixing member for supporting and fixing the nozzle portion 14a inside, and also forms the outer shell of the ejector 14. More specifically, the nozzle portion 14a is fixed by press fitting so as to be accommodated inside the body portion 14b on one end side in the longitudinal direction. The body portion 14b may be made of resin.

On the outer peripheral surface of the body portion 14b, a refrigerant suction port 14c provided so as to penetrate the inside and outside of the outer peripheral surface of the nozzle portion 14a and communicate with the refrigerant injection port of the nozzle portion 14a is formed. ing. The refrigerant suction port 14c is a through hole for sucking the refrigerant flowing out of the suction side evaporator 19, which will be described later, into the inside of the ejector 14 by the suction action of the jet refrigerant jetted from the nozzle portion 14a.

A suction passage and a diffuser portion 14d are formed inside the body portion 14b. The suction passage is a refrigerant passage that guides the suction refrigerant sucked from the refrigerant suction port 14c to the refrigerant injection port side of the nozzle portion 14a. The diffuser unit 14d is a boosting unit that mixes the suction refrigerant and the injection refrigerant to increase the pressure.

The suction passage is formed in the space between the outer peripheral side around the tapered tip portion of the nozzle portion 14a and the inner peripheral side of the body portion 14b, and the refrigerant passage area of the suction passage is directed toward the refrigerant flow direction. It is gradually shrinking. As a result, the flow velocity of the suction refrigerant flowing through the suction passage is gradually increased, and the energy loss (so-called mixing loss) when the suction refrigerant and the injection refrigerant are mixed in the diffuser portion 14d is reduced.

The diffuser portion 14d is a portion where a refrigerant passage extending in a truncated cone shape is formed so as to be continuous with the outlet of the suction passage. In the diffuser portion 14d, the cross-sectional area of the passage gradually expands toward the downstream side of the refrigerant flow. The diffuser portion 14d converts the kinetic energy of the mixed refrigerant into pressure energy by such a passage shape.

More specifically, the cross-sectional shape of the inner peripheral wall surface of the body portion 14b forming the diffuser portion 14d of the present embodiment is formed by combining a plurality of curves. Then, the degree of expansion of the cross-sectional area of the refrigerant passage of the diffuser portion 14d gradually increases in the direction of the flow of the refrigerant and then decreases again, so that the refrigerant can be is isotropically boosted.

The refrigerant inlet side of the outflow side evaporator 18 is connected to the outlet of the diffuser portion 14d. The outflow side evaporator 18 exchanges heat between the refrigerant flowing out from the diffuser unit 14d and the blown air blown from the indoor blower 18a toward the vehicle interior, and evaporates the refrigerant to exert a heat absorbing action to exert the blown air. It is a heat exchanger for heat absorption that cools.

The indoor blower 18a is an electric blower whose rotation speed (that is, the amount of blown air) is controlled by a control voltage output from the air conditioning control device 40. Further, the suction port side of the compressor 11 is connected to the refrigerant outlet side of the outflow side evaporator 18.

Next, the flow rate adjusting valve 20 will be described. The flow rate control valve 20 is an integrated (in other words, modularized) cycle component device surrounded by a broken line in FIG. More specifically, the flow rate adjusting valve 20 integrates a suction side decompression device 15, a bypass passage 16, a variable throttle device 17, and the like.

The suction side decompression device 15 is a suction side decompression unit that decompresses the other refrigerant branched at the branch portion 13 until it becomes a low pressure refrigerant. The suction side decompression device 15 is a variable throttle configured so that the passage cross-sectional area (that is, the throttle opening degree) of the throttle passage 20a for depressurizing the refrigerant can be changed. The suction side decompression device 15 causes the decompressed refrigerant to flow out to the refrigerant inlet side of the suction side evaporator 19, which will be described later.

The bypass passage 16 bypasses the suction side decompression device 15 (more specifically, the suction side decompression device 15) with the refrigerant on the inlet side of the suction side decompression device 15 (more specifically, the throttle passage 20a). It is a refrigerant passage leading to the outlet side (in other words, the refrigerant inlet side of the suction side evaporator 19) of the throttle passage 20a).

The variable throttle device 17 is a variable throttle mechanism unit that adjusts the flow rate of the refrigerant flowing through the bypass passage 16 (specifically, it is a mass flow rate, and the same applies to other flow rates). Further, the variable diaphragm device 17 has a function of opening and closing the bypass passage 16. More specifically, the variable throttle device 17 opens the bypass passage 16 when the flow rate Ge1 of the refrigerant flowing out from the suction side decompression device 15 is equal to or less than a predetermined reference flow rate KGe1.

The reference flow rate KGe1 is based on the temperature distribution of the blown air cooled by the suction side evaporator 19 when the variable throttle device 17 closes the bypass passage 16 and reduces the flow rate of the circulating refrigerant circulating in the cycle. It is set to a value that expands beyond the temperature difference.

The temperature distribution of the blown air is defined by the temperature difference obtained by subtracting the lowest temperature from the maximum temperature of the blown air immediately after being cooled by the suction side evaporator 19. Further, the reference temperature difference is set to a value at which the occupant begins to feel uncomfortable due to the temperature distribution.

The detailed configuration of the flow rate control valve 20 will be described with reference to FIGS. 2 to 4. The upper and lower arrows in FIGS. 2 to 4 indicate the upper and lower directions when the flow rate adjusting valve 20 is mounted on the vehicle.

The flow rate adjusting valve 20 has a body portion 21. The body portion 21 is formed by combining a plurality of metal components (in this embodiment, aluminum). The body portion 21 forms the outer shell of the flow rate adjusting valve 20 and functions as a housing for accommodating a part of the constituent devices such as the suction side decompression device 15 and the variable throttle device 17 inside. The body portion 21 may be made of resin.

Inside the body portion 21, various refrigerant passages such as a bypass passage 16, a throttle passage 20a, and a temperature-sensitive passage 20b are formed. A plurality of refrigerant inlets / outlets such as a refrigerant inlet 21a, an evaporator side outlet 21b, an evaporator side inlet 21c, and a low pressure outlet 21d are provided on the outer surface of the body portion 21.

The other refrigerant outlet side of the branch portion 13 is connected to the refrigerant inlet 21a. The refrigerant inlet 21a is a refrigerant inlet into which the other refrigerant branched at the branch portion 13 flows. The refrigerant inlet 21a communicates with the inlet side of the throttle passage 20a of the suction side decompression device 15 and the inlet side of the bypass passage 16 inside the body portion 21.

The refrigerant inlet side of the suction side evaporator 19 is connected to the evaporator side outlet 21b. The evaporator side outlet 21b is a refrigerant outlet that discharges the refrigerant decompressed by the suction side decompression device 15 and the refrigerant that has passed through the bypass passage 16 to the refrigerant inlet side of the suction side evaporator 19. The refrigerant outlet side of the suction side evaporator 19 is connected to the evaporator side inlet 21c. The evaporator side inlet 21c is a refrigerant inlet that allows the refrigerant flowing out of the suction side evaporator 19 to flow into the temperature sensitive passage 20b.

The refrigerant suction port 14c side of the ejector 14 is connected to the low pressure outlet 21d. The low-pressure outlet 21d is a refrigerant outlet that causes the refrigerant that has flowed through the temperature-sensitive passage 20b to flow out to the refrigerant suction port 14c side.

The suction side decompression device 15 has a throttle passage 20a, a throttle valve 51, a drive mechanism 52, and the like. The throttle passage 20a is a refrigerant passage that reduces the pressure of the other refrigerant branched at the branch portion 13 by reducing the cross-sectional area of the passage. The throttle passage 20a is formed in a rotating body shape such as a hemispherical shape or a truncated cone shape. The throttle passage 20a of the present embodiment is integrally formed with the body portion 21. Of course, the throttle passage 20a may be formed by fixing the orifice formed of another member to the body portion 21 to the body portion 21 by means such as press fitting.

The throttle valve 51 is formed in a spherical shape and is displaced in the central axis direction of the throttle passage 20a to change the minimum passage cross-sectional area (that is, the throttle opening degree) of the throttle passage 20a. Further, the throttle passage 20a can be closed by bringing the throttle valve 51 into contact with the outlet portion of the throttle passage 20a. The throttle valve 51 receives a load from the coil spring 52e, which is an elastic member, on the side that reduces the throttle opening of the throttle passage 20a.

The drive mechanism 52 is a drive unit that displaces the throttle valve 51 in the central axis direction of the throttle passage 20a. The drive mechanism 52 is composed of a mechanical mechanism. The drive mechanism 52 has a temperature-sensitive portion 52a in which a diaphragm 52b, which is a deforming member that deforms according to the temperature and pressure of the refrigerant flowing out of the suction side evaporator 19, is arranged. In the drive mechanism 52, the throttle valve 51 is displaced by transmitting the deformation of the diaphragm 52b to the throttle valve 51 via the operating rod 53.

The diaphragm 52b divides the space formed in the temperature-sensitive portion 52a into an enclosed space 52c and an introduction space 52d. In the enclosed space 52c, a temperature-sensitive medium whose pressure changes with a temperature change is enclosed. In the present embodiment, as the temperature-sensitive medium, a medium containing a refrigerant circulating in the ejector type refrigeration cycle 10 as a main component is adopted.

Further, the temperature sensitive portion 52a is fixed to the body portion 21 so that the introduction space 52d communicates with the temperature sensitive passage 20b. Therefore, the pressure of the temperature-sensitive medium in the enclosed space 52c changes according to the temperature of the refrigerant flowing through the temperature-sensitive passage 20b (that is, the refrigerant flowing out from the suction side evaporator 19). Then, the diaphragm 52b is deformed according to the pressure difference between the pressure of the refrigerant flowing through the temperature-sensitive passage 20b and the pressure of the temperature-sensitive medium in the enclosed space 52c.

Therefore, it is desirable that the diaphragm 52b is made of a material that is highly elastic and has excellent pressure resistance and airtightness. Therefore, in the present embodiment, a circular metal thin plate made of stainless steel (specifically, SUS304) is adopted as the diaphragm 52b. Of course, as the diaphragm 52b, one made of rubber containing a base cloth (for example, polyester) (for example, ethylene propylene diene rubber or hydrogenated nitrile rubber) may be adopted.

In the temperature sensitive portion 52a of the present embodiment, when the temperature (superheat degree) of the refrigerant flowing through the temperature sensitive passage 20b rises, the saturation pressure of the temperature sensitive medium in the sealed space 52c of the drive mechanism 52 rises, and the sealed space The pressure difference between the pressure of the temperature-sensitive medium in 52c and the pressure of the refrigerant flowing through the temperature-sensitive passage 20b becomes large. As a result, when the diaphragm 52b is deformed, the throttle valve 51 is displaced to the side where the throttle opening of the throttle passage 20a is increased.

On the other hand, when the temperature (superheat degree) of the low-pressure refrigerant flowing through the temperature-sensitive passage 20b decreases, the saturation pressure of the temperature-sensitive medium in the enclosed space 52c decreases, and the pressure of the temperature-sensitive medium in the enclosed space 52c reduces the temperature. The pressure difference between the pressures of the low-pressure refrigerant flowing through the passage 20b becomes small. As a result, when the diaphragm 52b is deformed, the throttle valve 51 is displaced to the side where the throttle opening of the throttle passage 20a is reduced.

That is, the drive mechanism 52 can displace the throttle valve 51 according to the temperature and pressure of the refrigerant on the outlet side of the suction side evaporator 19, similarly to the so-called thermal expansion valve. In other words, the drive mechanism 52 can displace the throttle valve 51 according to the degree of superheat of the refrigerant on the outlet side of the suction side evaporator 19.

Therefore, in the drive mechanism 52, the throttle valve 51 is displaced so that the superheat degree SH1 of the refrigerant on the outlet side of the suction side evaporator 19 approaches a predetermined reference superheat degree KSH1 (specifically, 0 ° C.). In other words, the suction side decompression device 15 changes the throttle opening degree so that the superheat degree SH1 of the refrigerant on the outlet side of the suction side evaporator 19 approaches the reference superheat degree KSH1. Further, the reference superheat degree KSH1 can be adjusted by changing the load of the coil spring 52e.

The bypass passage 16 is formed by a part of the first passage 16a formed in the body portion 21 and the second passage 16b. The first passage 16a is formed so as to connect the inlet side (specifically, the inlet side of the throttle passage 20a) of the suction side decompression device 15 and the temperature sensitive passage 20b. The first passage 16a is formed in a substantially columnar shape. The central axis of the first passage 16a extends parallel to the displacement direction of the throttle valve 51.

The second passage 16b is formed so as to connect the first passage 16a and the outlet side of the suction side decompression device 15 (specifically, the outlet side of the throttle passage 20a). The second passage 16b is formed in a substantially columnar shape. The second passage 16b extends from a portion of the body portion 21 forming the side surface of the first passage 16a in a direction perpendicular to the central axis of the first passage 16a.

Inside the first passage 16a, a substantially columnar valve body portion 17a constituting the variable throttle device 17 is arranged. Inside the valve body portion 17a, a communication passage for communicating the first passage 16a and the second passage 16b is formed.

The valve body portion 17a is displaced in the direction of the central axis of the first passage 16a to open and close the inlet portion of the second passage 16b, thereby opening and closing the bypass passage 16. Further, the valve body portion 17a is displaced in the central axis direction of the first passage 16a to change the passage cross-sectional area of the inlet portion of the second passage 16b, thereby changing the throttle opening of the variable throttle device 17 as a whole. Let me.

The valve body portion 17a flows through an inlet-side pressure receiving surface that receives the inlet-side pressure Pri, which is the pressure of the refrigerant that has flowed in from the refrigerant inlet 21a (that is, the refrigerant on the inlet side of the suction-side decompression device 15), and the temperature-sensitive passage 20b. It has an outlet-side pressure receiving surface that receives the outlet-side pressure Peo, which is the pressure of the refrigerant (that is, the refrigerant flowing out of the suction-side evaporator 19.). The area of the pressure receiving surface on the inlet side and the area of the pressure receiving surface on the lower stage side are set to be approximately the same.

Further, a sealing member such as an O-ring is interposed in the gap between the inner peripheral surface of the first passage 16a and the outer peripheral surface of the valve body portion 17a, and the refrigerant does not leak from the gap between these members. Further, the valve body portion 17a receives a load on the side that opens the bypass passage 16 from the coil spring 17b, which is an elastic member.

Therefore, the valve body portion 17a of the present embodiment is displaced according to the load generated by the pressure difference ΔP (ΔP = Pri-Peo) obtained by subtracting the outlet side pressure Peo from the inlet side pressure Pri and the load received from the coil spring 17b. ..

More specifically, in the variable throttle device 17 of the present embodiment, when the pressure difference ΔP is larger than the predetermined reference pressure difference KΔP, as shown in FIG. 2, the coil spring 17b is compressed. The valve body portion 17a is displaced to bring the bypass passage 16 into a fully closed state.

When the pressure difference ΔP becomes equal to or less than the reference pressure difference KΔP, as shown in FIG. 3, the position where the valve body portion 17a communicates with the first passage 16a and the second passage 16b by the load of the coil spring 17b. Displace to. Then, by slightly opening the inlet portion of the second passage 16b, the throttle state in which the decompression action is exerted is achieved.

Further, as the pressure difference ΔP is reduced, the throttle opening degree is increased. Then, as shown in FIG. 4, the valve body portion 17a is displaced until the passage cross-sectional area of the entrance portion of the second passage 16b is maximized, so that the bypass passage 16 is fully opened.

In the present embodiment, the pressure difference ΔP at which the flow rate Ge1 of the refrigerant flowing out from the suction side decompression device 15 becomes the reference flow rate KGe1 is set as the reference pressure difference KΔP. Therefore, the variable throttle device 17 opens the bypass passage 16 when the flow rate Ge1 of the refrigerant flowing out from the suction side decompression device 15 is equal to or less than the reference flow rate KGe1. Further, the reference pressure difference KΔP can be adjusted by changing the load of the coil spring 17b.

As shown in FIG. 1, the refrigerant inlet side of the suction side evaporator 19 is connected to the evaporator side outlet 21b of the flow rate adjusting valve 20. The suction side evaporator 19 exchanges heat between the refrigerant flowing out from the evaporator side outlet 21b of the flow control valve 20 and the blown air passing through the outflow side evaporator 18 to evaporate the refrigerant and exert a heat absorbing action. It is a heat absorber for heat absorption that cools the blown air.

The evaporator side inlet 21c side of the flow rate adjusting valve 20 is connected to the refrigerant outlet of the suction side evaporator 19. As described above, the refrigerant suction port 14c side of the ejector 14 is connected to the low pressure outlet 21d of the flow rate adjusting valve 20. That is, the refrigerant suction port 14c side of the ejector 14 is connected to the refrigerant outlet of the suction side evaporator 19 via the temperature sensitive passage 20b of the flow rate adjusting valve 20.

Further, the outflow side evaporator 18 and the suction side evaporator 19 of the present embodiment are integrally configured. Specifically, the outflow side evaporator 18 and the suction side evaporator 19 both aggregate or distribute a plurality of tubes through which the refrigerant flows, and the refrigerants arranged on both ends of the plurality of tubes and flowing through the tubes. It is composed of a so-called tank-and-tube type heat exchanger having a pair of collecting and distributing tanks.

Then, the outflow side evaporator 18 and the suction side evaporator 19 are integrated by forming the collective distribution tank of the outflow side evaporator 18 and the suction side evaporator 19 with the same member. In the present embodiment, the outflow side evaporator 18 and the suction side evaporator 19 are arranged in series with respect to the blown air flow so that the outflow side evaporator 18 is arranged on the upstream side of the blown air flow with respect to the suction side evaporator 19. It is placed in. Therefore, the blast air flows as shown by the arrow drawn by the two-dot chain line in FIG.

Next, the electric control unit of the ejector type refrigeration cycle 10 of the present embodiment will be described. The air-conditioning control device 40 (not shown) is composed of a well-known microcomputer including a CPU, ROM, RAM, etc. and its peripheral circuits, performs various calculations and processes based on the air-conditioning control program stored in the ROM, and performs various calculations and processes on the output side. It controls the operation of various controlled devices 11, 12a, 18a connected to the above.

On the input side of the air conditioning control device 40, an inside temperature sensor that detects the vehicle interior temperature Tr, an outside temperature sensor that detects the outside temperature Tam, a solar radiation sensor that detects the amount of solar radiation As in the vehicle interior, and a suction side evaporator 19 blow out. A sensor group for air conditioning control such as an evaporator temperature sensor that detects the blown air temperature (evaporator temperature) Tefin is connected, and the detection value of these air conditioning sensor groups is input.

Further, an operation panel (not shown) is connected to the input side of the air conditioning control device 40, and operation signals from various operation switches provided on the operation panel are input to the air conditioning control device 40. As various operation switches provided on the operation panel, an air-conditioning operation switch that requires air conditioning, a vehicle interior temperature setting switch that sets the vehicle interior temperature, and the like are provided.

The air-conditioning control device 40 of the present embodiment is integrally composed of a control unit that controls the operation of various controlled devices connected to the output side of the air-conditioning control device 40. The configuration (hardware and software) that controls the operation of the controlled device constitutes the control unit of each controlled device. For example, a configuration that controls the operation of the compressor 11 constitutes a discharge capacity control unit.

Next, the operation of the ejector type refrigeration cycle 10 of the present embodiment in the above configuration will be described. When the air-conditioning operation switch on the operation panel is turned on (ON), the air-conditioning control device 40 executes the air-conditioning control program stored in advance to control the operation of the various controlled devices 11, 12a, 18a.

In this air conditioning control program, the target blowing temperature TAO of the blown air blown into the vehicle interior is calculated based on the detection signal of the sensor group for air conditioning control and the operation signal from the operation panel. Then, the operating state of each controlled device is determined based on the target blowing temperature TAO or the like. For example, with respect to the compressor 11, it is determined that the refrigerant discharge capacity (in the present embodiment, the number of revolutions) is reduced as the target blowout temperature TAO rises.

Here, the target blowout temperature TAO is a value having a correlation with the amount of heat (in other words, the heat load of the ejector type refrigerating cycle 10) that the ejector type refrigerating cycle needs to generate in order to keep the vehicle interior at a desired temperature. .. Therefore, when cooling the vehicle interior, reducing the refrigerant discharge capacity of the compressor 11 as the target outlet temperature TAO rises reduces the refrigerant discharge capacity of the compressor 11 as the cooling heat load decreases. It means to lower it.

Then, when the air conditioning control device 40 reduces the refrigerant discharge capacity of the compressor 11 as the cooling heat load decreases, the flow rate of the circulating refrigerant circulating in the cycle decreases, and the refrigerant flowing out from the suction side decompression device 15 decreases. The flow rate Ge1 also decreases. Further, when the refrigerant discharge capacity of the compressor 11 is reduced as the cooling heat load is reduced, the inlet side pressure Pri is lowered and the pressure difference ΔP is also reduced.

Therefore, in the present embodiment, the operating condition in which the cooling heat load is relatively high and the flow rate Ge1 of the refrigerant flowing out from the suction side decompression device 15 is larger than the reference flow rate KGe1 is defined as normal operation. Normal operation is performed when the outside temperature is relatively high, for example, in the summer.

Further, an operating condition in which the cooling heat load is relatively low and the flow rate Ge1 of the refrigerant flowing out from the suction side decompression device 15 is equal to or less than the reference flow rate KGe1 is defined as low load operation. The low load operation is executed, for example, when the outside air temperature is relatively low such as in spring or autumn, or when the vehicle window is protected from fogging when the outside air temperature is low.

When the air conditioning control device 40 operates the compressor 11, the high-temperature high-pressure refrigerant discharged from the compressor 11 flows into the radiator 12. The refrigerant flowing into the radiator 12 exchanges heat with the outside air blown from the cooling fan 12a, and is cooled and condensed. The flow of the refrigerant flowing out of the radiator 12 is branched at the branch portion 13. One of the refrigerants branched at the branch portion 13 flows into the nozzle portion 14a of the ejector 14.

The refrigerant that has flowed into the nozzle portion 14a of the ejector 14 is isotropically depressurized by the nozzle portion 14a and is injected from the refrigerant injection port of the nozzle portion 14a. Then, due to the suction action of the injected refrigerant, the refrigerant flowing out of the suction side evaporator 19 is sucked from the refrigerant suction port 14c through the temperature sensitive passage 20b of the flow rate adjusting valve 20.

The injection refrigerant injected from the refrigerant injection port of the nozzle portion 14a and the suction refrigerant sucked from the refrigerant suction port 14c flow into the diffuser portion 14d. In the diffuser portion 14d, the velocity energy of the refrigerant is converted into pressure energy by expanding the refrigerant passage area. As a result, the pressure of the mixed refrigerant of the injection refrigerant and the suction refrigerant increases. The refrigerant boosted by the diffuser unit 14d flows into the outflow side evaporator 18.

The refrigerant flowing into the outflow side evaporator 18 absorbs heat from the blown air blown by the indoor blower 18a and evaporates. As a result, the blown air blown by the indoor blower 18a is cooled. The refrigerant flowing out of the outflow side evaporator 18 is sucked into the compressor 11 and compressed again.

On the other hand, the other refrigerant branched at the branch portion 13 flows into the refrigerant inlet 21a of the flow rate adjusting valve 20. Here, since the variable throttle device 17 closes the bypass passage 16 during normal operation, the total flow rate of the refrigerant flowing into the refrigerant inlet 21a of the flow rate adjusting valve 20 is reduced by the suction side decompression device 15 to adjust the flow rate. It flows out from the evaporator side outlet 21b of the valve 20.

Further, since the variable throttle device 17 opens the bypass passage 16 during low load operation, the refrigerant flowing into the refrigerant inlet 21a of the flow rate adjusting valve 20 is decompressed by both the suction side decompression device 15 and the bypass passage 16. Then, it flows out from the evaporator side outlet 21b of the flow rate adjusting valve 20.

At this time, in the suction side decompression device 15, the superheat degree SH1 of the refrigerant on the outlet side of the suction side evaporator 19 approaches the reference superheat degree KSH1 in both normal operation and low load operation regardless of the load fluctuation. The aperture opening is adjusted so as to.

The refrigerant flowing out from the evaporator side outlet 21b of the flow rate adjusting valve 20 flows into the suction side evaporator 19. The refrigerant flowing into the suction side evaporator 19 absorbs heat from the blown air after passing through the outflow side evaporator 18 and evaporates. As a result, the blown air after passing through the outflow side evaporator 18 is further cooled. The refrigerant flowing out of the suction side evaporator 19 is sucked from the refrigerant suction port 14c.

Therefore, according to the ejector type refrigeration cycle 10 of the present embodiment, the outflow side evaporator 18 and the suction side evaporator 19 are used in the vehicle interior regardless of the load fluctuation, both in the normal operation and in the low load operation. The blown air blown to can be cooled.

Further, in the ejector type refrigeration cycle 10 of the present embodiment, the refrigerant boosted by the diffuser portion 14d of the ejector 14 is sucked into the compressor 11 via the outflow side evaporator 18. According to this, the coefficient of performance of the cycle is reduced by reducing the power consumption of the compressor 11 as compared with a normal refrigerating cycle device in which the refrigerant evaporation pressure in the evaporator and the pressure of the suction refrigerant sucked into the compressor are substantially equal to each other. (COP) can be improved.

Further, in the ejector type refrigeration cycle 10 of the present embodiment, the variable throttle device 17 of the flow rate adjusting valve 20 closes the bypass passage 16 during normal operation. Therefore, during normal operation, the suction side decompression device 15 adjusts the throttle opening degree, so that the refrigerant on the outlet side of the suction side evaporator 19 can be used as a vapor phase refrigerant having a degree of superheat.

According to this, it is possible to suppress an unnecessary increase in the flow rate of the refrigerant sucked from the refrigerant suction port 14c of the ejector 14, and to suppress a decrease in the boosting amount in the diffuser portion 14d. can. That is, it is possible to prevent the COP of the cycle from decreasing.

However, even during low load operation, if the suction side decompression device 15 adjusts the throttle opening as in normal operation, the flow rate of the refrigerant flowing into the suction side evaporator 19 decreases, so that the suction side evaporator 19 The temperature distribution generated in the blown air cooled by is expanded. That is, even if the throttle opening of the suction side decompression device 15 is adjusted so that the superheat degree SH1 of the refrigerant on the outlet side of the suction side evaporator 19 approaches the reference superheat degree KSH1, the suction side according to the load fluctuation of the cycle. The flow rate of the refrigerant flowing into the evaporator 19 cannot be adjusted appropriately.

On the other hand, in the ejector type refrigeration cycle 10 of the present embodiment, the variable throttle device 17 of the flow rate adjusting valve 20 opens the bypass passage 16 during the low load operation, so that the suction side pressure reducing device 15 reduces the throttle opening. Even so, the refrigerant that has passed through the bypass passage 16 can be reliably discharged to the inlet side of the suction side evaporator 19. Therefore, it is possible to prevent the flow rate of the refrigerant flowing into the suction side evaporator 19 from becoming insufficient during low load operation.

That is, according to the flow rate adjusting valve 20 of the present embodiment, when applied to the ejector type refrigerating cycle 10, the flow rate of the refrigerant flowing into the suction side evaporator 19 is appropriately adjusted according to the load fluctuation of the cycle. be able to. In other words, according to the ejector type refrigeration cycle 10 of the present embodiment, since the flow rate adjusting valve 20 is provided, the flow rate of the refrigerant flowing into the suction side evaporator 19 is appropriately adjusted according to the load fluctuation of the cycle. be able to.

Further, the variable throttle device 17 of the flow rate adjusting valve 20 of the present embodiment increases the throttle opening degree as the pressure difference ΔP decreases. Therefore, as the flow rate Ge1 of the refrigerant flowing out from the suction side decompression device 15 decreases, the flow rate of the refrigerant flowing out to the inlet side of the suction side evaporator 19 through the bypass passage 16 can be increased. According to this, the flow rate of the refrigerant flowing into the suction side evaporator 19 can be adjusted more appropriately according to the load fluctuation of the cycle.

(Second Embodiment)
In this embodiment, as shown in FIG. 5, an example in which the configuration of the flow rate adjusting valve 20 is changed with respect to the first embodiment will be described. FIG. 5 is a drawing in which the variable diaphragm device 17 of the present embodiment is in a fully open state of the bypass passage 16 as in FIG. 4 described in the first embodiment. Further, in FIG. 5, the same or equal parts as those in the first embodiment are designated by the same reference numerals. This also applies to the following drawings.

More specifically, in the flow rate adjusting valve 20 of the present embodiment, one end of the first passage 16a of the bypass passage 16 is on the inlet side of the suction side decompression device 15 (specifically, the inlet side of the throttle passage 20a). However, the other end of the first passage 16a does not communicate with the temperature sensitive passage 20b.

Further, in the present embodiment, the inner peripheral surface of the first passage 16a and the valve body portion 17a so that the pressure Psp in the spring chamber 17c in which the coil spring 17b is housed becomes equal to the refrigerant pressure on the outlet side of the throttle passage 20a. A part of the sealing member interposed in the gap between the outer peripheral surface and the outer peripheral surface is omitted. Therefore, the valve body portion 17a of the present embodiment is displaced according to the pressure difference obtained by subtracting the pressure Psp in the spring chamber 17c from the inlet side pressure Pri and the load received from the coil spring 17b.

Here, since the gap between the inner wall surface of the first passage 16a and the valve body portion 17a is relatively small, the pressure Psp in the spring chamber 17c has high responsiveness according to the change in the refrigerant pressure on the outlet side of the throttle passage 20a. It does not change, but is a substantially constant value. Therefore, the valve body portion 17a of the present embodiment is substantially displaced according to the load generated by the inlet side pressure Pri and the load received from the coil spring 17b.

More specifically, when the inlet side pressure Pri is larger than the predetermined reference pressure KPri, the valve body portion 17a is displaced to the side where the coil spring 17b is compressed, and the bypass passage 16 is fully closed. do.

When the inlet side pressure Pri becomes equal to or less than the reference pressure KPri, the valve body portion 17a is displaced to a position where the first passage 16a and the second passage 16b communicate with each other by the load of the coil spring 17b, and the bypass passage 16 is formed. Set to the squeezed state.

Further, as the inlet side pressure Pri decreases, the throttle opening degree is increased. Then, as shown in FIG. 5, the valve body portion 17a is displaced until the passage cross-sectional area of the inlet portion of the second passage 16b is maximized, and the bypass passage 16 is fully opened.

Further, in the present embodiment, the inlet pressure Pri at which the flow rate Ge1 of the refrigerant flowing out from the suction side decompression device 15 becomes the reference flow rate KGe1 is set to the reference pressure KPri. As a result, the variable throttle device 17 opens the bypass passage 16 when the flow rate Ge1 of the refrigerant flowing out from the suction side decompression device 15 is equal to or less than the reference flow rate KGe1. The reference pressure KPri can be adjusted by changing the load of the coil spring 17b.

The other flow control valves 20 and the ejector type refrigeration cycle 10 are configured and operated in the same manner as in the first embodiment. That is, during the normal operation of the ejector type refrigeration cycle 10, the variable throttle device 17 of the flow rate adjusting valve 20 closes the bypass passage 16. Further, during the low load operation of the ejector type refrigeration cycle 10, the variable throttle device 17 of the flow rate adjusting valve 20 opens the bypass passage 16.

Therefore, according to the flow rate adjusting valve 20 of the present embodiment, as in the first embodiment, when applied to the ejector type refrigerating cycle 10, it flows into the suction side evaporator 19 according to the load fluctuation of the cycle. The flow rate of the refrigerant can be adjusted appropriately. In other words, according to the ejector type refrigeration cycle 10 of the present embodiment, since the flow rate adjusting valve 20 is provided, the flow rate of the refrigerant flowing into the suction side evaporator 19 is appropriately adjusted according to the load fluctuation of the cycle. be able to.

Further, the variable throttle device 17 of the flow rate adjusting valve 20 of the present embodiment increases the throttle opening degree as the inlet side pressure Pri decreases. Therefore, as the flow rate Ge1 of the refrigerant flowing out from the suction side decompression device 15 decreases, the flow rate of the refrigerant flowing out to the inlet side of the suction side evaporator 19 through the bypass passage 16 can be increased. According to this, the flow rate of the refrigerant flowing into the suction side evaporator 19 can be adjusted more appropriately according to the load fluctuation of the cycle.

(Third Embodiment)
In this embodiment, as shown in FIG. 6, an example in which the configuration of the flow rate adjusting valve 20 is changed will be described. FIG. 6 is a drawing in which the variable diaphragm device 17 of the present embodiment is in a fully open state of the bypass passage 16 as in FIG. 4 described in the first embodiment. In the variable throttle device 17 of the flow rate adjusting valve 20 of the present embodiment, the throttle opening can be increased with higher accuracy than that of the second embodiment as the inlet side pressure Pri decreases.

More specifically, in the flow rate adjusting valve 20 of the present embodiment, a part of the first passage 16a of the bypass passage 16 is formed into a rotating body shape such as a hemispherical shape or a truncated cone shape similar to the throttle passage 20a. There is. Further, as the valve body portion 17d, a spherical one similar to the throttle valve 51 is adopted. The valve body portion 17d receives a load from the coil spring 17b on the side that reduces the cross-sectional area of a part of the first passage 16a.

In the flow rate adjusting valve 20 of the present embodiment, the minimum passage cross-sectional area (that is, the throttle opening) of the first passage 16a can be changed by displacing the valve body portion 17d. Further, the first passage 16a can be closed by bringing the valve body portion 17d into contact with the first passage 16a.

Further, the flow rate adjusting valve 20 of the present embodiment has a drive mechanism 71 for the variable throttle device 17 as a drive unit for driving and displacementing the valve body portion 17d. The basic configuration of the drive mechanism 71 for the variable aperture device 17 is the same as that of the drive mechanism 52.

Therefore, the drive mechanism 71 has a temperature sensitive portion 72. The temperature-sensitive portion 72 has a diaphragm 72b which is a deformable member that partitions the space inside the temperature-sensitive portion 72 into an enclosed space 72c and an introduction space 72d. An inert gas (nitrogen gas in this embodiment) is enclosed in the enclosed space 72c of the drive mechanism 71. The introduction space 72d of the drive mechanism 71 is fixed to the body portion 21 so as to communicate with the inlet side of the suction side decompression device 15 (specifically, the throttle passage 20a).

Therefore, the diaphragm 72b is deformed according to the pressure difference between the pressure of the refrigerant on the inlet side of the suction side decompression device 15 and the pressure of the inert gas in the enclosed space 72c. Further, in the drive mechanism 71, the valve body portion 17d is displaced by transmitting the deformation of the diaphragm 72b to the valve body portion 17d via the operating rod 73.

Here, the volume change due to the temperature of the inert gas is relatively small. Therefore, even if the temperature of the refrigerant on the inlet side of the suction side decompression device 15 introduced into the introduction space 72d and the outside air temperature change, the pressure of the inert gas in the enclosed space 72c becomes substantially constant. Therefore, in the variable throttle device 17 of the present embodiment, the throttle opening can be increased with the decrease of the inlet side pressure Pri with higher accuracy than that of the second embodiment.

The configuration and operation of the other flow rate control valve 20 and the ejector type refrigeration cycle 10 are the same as those in the second embodiment. Therefore, the same effect as that of the second embodiment can be obtained in the flow rate control valve 20 and the ejector type refrigeration cycle 10 of the present embodiment.

(Fourth Embodiment)
In this embodiment, as shown in FIG. 7, an example in which the configuration of the flow rate adjusting valve 20 is changed with respect to the first embodiment will be described. Specifically, in the flow rate adjusting valve 20 of the present embodiment, the variable throttle device 17 is abolished. Therefore, in the flow rate adjusting valve 20 of the present embodiment, the passage cross-sectional area of the bypass passage 16 can appropriately adjust the flow rate of the refrigerant flowing into the suction side evaporator 19 according to the load fluctuation of the cycle. Is set to.

Specifically, in the present embodiment, a predetermined reference medium temperature (that is, the outlet side pressure Peo) determined from the pressure of the refrigerant flowing through the temperature sensitive passage 20b of the flow control valve 20 and flowing out from the low pressure outlet 21d (this embodiment). In the embodiment, the value obtained by subtracting the saturation pressure of the temperature-sensitive medium at 0 ° C.) is defined as the valve opening set pressure Y. The detailed measurement method of the valve opening set pressure Y will be described later.

Further, the maximum value of the passage cross-sectional area of the suction side decompression device 15 is defined as the maximum throttle cross-sectional area Ax, and the minimum value of the passage cross-sectional area of the bypass passage 16 is defined as the minimum passage cross-sectional area Apt. Further, the ratio (Apt / Ax) of the maximum passage cross-sectional area Apt to the maximum throttle cross-sectional area Ax is defined as the area ratio X.

Here, the maximum throttle cross-sectional area Ax can be determined based on the maximum circulation flow rate of the refrigerant circulating in the cycle. Therefore, in the flow rate adjusting valve 20, the area ratio X can be changed mainly by changing the minimum passage cross-sectional area Apt.

Further, as the area ratio X increases, the ratio of the flow rate of the refrigerant flowing into the suction side evaporator 19 through the bypass passage 16 tends to increase. Therefore, if the area ratio X is set large, even if the suction side decompression device 15 changes the throttle opening during normal operation, the superheat degree SH1 of the refrigerant on the outlet side of the suction side evaporator 19 becomes the reference superheat degree KSH1. It may be difficult to approach.

On the other hand, as the area ratio X becomes smaller, the ratio of the flow rate of the refrigerant flowing into the suction side evaporator 19 through the bypass passage 16 decreases. Therefore, if the area ratio X is set small, the flow rate of the refrigerant flowing into the suction side evaporator 19 may be insufficient when the suction side decompression device 15 reduces the throttle opening during low load operation. be.

For this reason, it is necessary to adjust the area ratio X to a predetermined range in order to allow the refrigerant having an appropriate flow rate to flow into the suction side evaporator 19 during both normal operation and low load operation. However, it is difficult to accurately set an appropriate area ratio X according to the cooling capacity actually required for the ejector type refrigeration cycle 10.

Therefore, the present inventors have focused on the fact that the valve opening set pressure Y of the flow rate adjusting valve 20 is related to the flow rate of the refrigerant flowing from the flow rate adjusting valve 20 to the suction side evaporator 19, and the valve opening setting pressure. In relation to Y, we examined how to determine the area ratio X systematically.

Here, the valve opening set pressure Y in the present embodiment is determined in advance from the "expansion valve outlet pressure" in the "static superheat degree test method for expansion valves for automobile air conditioners" of the "Japan Refrigeration and Air Conditioning Industry Association Standard". It corresponds to the pressure obtained by subtracting the saturation pressure of the temperature-sensitive medium in the enclosed space 52c at the reference medium temperature (0 ° C. in this embodiment).

More specifically, in the present embodiment, as shown in FIG. 8, the pressure Py of the refrigerant flowing out from the low pressure outlet 21d of the flow rate adjusting valve 20 is measured, and the valve opening set pressure Y is determined using this value. ing. First, air having a test reference pressure KTPa (KTPa = 1.03 ± 0.05 MPa in this embodiment) is made to flow into the refrigerant inlet 21a of the flow rate adjusting valve 20.

The inlet portion of the pressure vessel BT is connected to the evaporator side outlet 21b of the flow rate adjusting valve 20, and the evaporator side inlet 21c of the flow rate regulating valve 20 is connected to the outlet portion of the pressure vessel BT. The pressure vessel BT forms a buffer space corresponding to the suction side evaporator 19. In this embodiment, a pressure vessel BT having an internal volume of the buffer space of 0.001 m ³ is adopted.

Then, the pressure Py of the air flowing out from the low pressure outlet 21d of the flow rate adjusting valve 20 is measured with the temperature of the temperature sensitive medium in the enclosed space 52c as the reference medium temperature. On the downstream side of the low pressure outlet 21d, an orifice that causes a predetermined pressure loss for measuring the pressure Py is arranged. The pressure Py is substantially a pressure corresponding to the outlet side pressure Peo, which is the pressure of the refrigerant flowing out from the suction side evaporator during the operation of the ejector type refrigeration cycle 10. Further, a value obtained by subtracting the saturation pressure of the temperature-sensitive medium, which is the reference medium temperature, from the pressure Py is determined as the valve opening set pressure Y.

The valve opening set pressure Y is adjusted by changing the load of the coil spring 52e, similarly to the reference superheat degree KSH1.

Therefore, when the reference superheat degree KSH1 is determined, the throttle opening of the suction side decompression device 15 increases as the valve opening set pressure Y is set to a high value. Therefore, the area ratio X may be lowered as the valve opening set pressure Y is set to a high value. On the other hand, as the valve opening set pressure Y is set to a low value, the throttle opening degree of the suction side decompression device 15 decreases. Therefore, the area ratio X may be increased as the valve opening set pressure Y is set to a low value.

As a result, as shown in FIG. 9, the present inventors set the area ratio X and the valve opening set pressure Y so as to satisfy the following formulas F1 and F2 during normal operation to obtain an appropriate flow rate. It was confirmed that the refrigerant could be supplied to the suction side evaporator 19.

-170X + 3 ≧ Y… (F1)
Y ≧ -175X-60… (F2)
On the other hand, during low load operation, it is confirmed that the refrigerant of an appropriate flow rate can be supplied to the suction side evaporator 19 by setting the area ratio X and the valve opening set pressure Y so as to satisfy the following formula F3. did.

Y ≧ -350X-9… (F3)
Then, the present inventors determine the area ratio X and the valve opening set pressure Y so as to satisfy the mathematical formulas F1 and F3 (so as to enter the shaded hatching region of FIG. 9) as practically effective ranges. ing. In other words, the loads of the maximum throttle cross-sectional area Ax, the minimum passage cross-sectional area Apt, and the coil spring 52e are adjusted so as to satisfy the equations F1 and F3.

That is, by satisfying the formula F1, the area ratio X and the valve opening set pressure are not unnecessarily increased so that the ratio of the flow rate of the refrigerant flowing into the suction side evaporator 19 through the bypass passage 16 does not increase unnecessarily during normal operation. Y is decided. Further, by satisfying the equation F3, the area ratio X and the valve opening set pressure Y are determined so that the flow rate of the refrigerant flowing into the suction side evaporator 19 is not insufficient during the low load operation.

Other configurations of the flow rate control valve 20 and the ejector type refrigeration cycle 10 are the same as those of the first embodiment.

Therefore, when the ejector type refrigerating cycle 10 of the present embodiment is operated, the refrigerant decompressed by the suction side decompression device 15 regardless of the load fluctuation, regardless of whether it is in normal operation or low load operation. Both the refrigerant and the refrigerant that has passed through the bypass passage 16 can flow out from the evaporator side outlet 21b and flow into the suction side evaporator 19.

Here, under operating conditions where the flow rate of the refrigerant flowing into the suction side evaporator 19 is relatively large as in normal operation, the suction side decompression device 15 increases the throttle opening degree. Therefore, the ratio of the flow rate of the refrigerant flowing into the suction side evaporator 19 through the suction side decompression device 15 increases from the flow rate of the refrigerant flowing into the suction side evaporator 19. In other words, the degree of influence of the change in the throttle opening of the suction side decompression device 15 becomes large with respect to the change in the flow rate of the refrigerant flowing into the suction side evaporator 19.

Further, in the present embodiment, the area ratio X and the valve opening set pressure Y are set so as to satisfy the above formula F1. Therefore, even if the bypass passage 16 is not closed, the suction side decompression device 15 changes the throttle opening so that the superheat degree of the refrigerant on the outlet side of the suction side evaporator 19 approaches the reference superheat degree. The flow rate of the refrigerant flowing into the suction side evaporator 19 can be adjusted.

On the other hand, under operating conditions where the flow rate of the refrigerant flowing into the suction side evaporator 19 is relatively small, such as during low load operation, the suction side decompression device 15 reduces the throttle opening. Therefore, the ratio of the flow rate of the refrigerant passing through the bypass passage 16 to the flow rate of the refrigerant flowing into the suction side evaporator 19 increases. In other words, the degree of influence of the change in the throttle opening of the suction side decompression device 15 is small with respect to the change in the flow rate of the refrigerant flowing into the suction side evaporator 19 during low load operation.

Further, in the present embodiment, the area ratio X and the valve opening set pressure Y are set so as to satisfy the above formula F3. Therefore, during low load operation, even if the suction side decompression device 15 reduces the throttle opening degree, the refrigerant that has passed through the bypass passage 16 can be reliably flowed into the suction side evaporator 19. As a result, it is possible to prevent the flow rate of the refrigerant flowing into the suction side evaporator 19 from becoming insufficient.

That is, according to the flow rate adjusting valve 20 of the present embodiment, when applied to the ejector type refrigerating cycle 10, the flow rate of the refrigerant flowing into the suction side evaporator 19 is appropriately adjusted according to the load fluctuation of the cycle. be able to. In other words, according to the ejector type refrigeration cycle 10 of the present embodiment, since the flow rate adjusting valve 20 is provided, the flow rate of the refrigerant flowing into the suction side evaporator 19 is appropriately adjusted according to the load fluctuation of the cycle. be able to.

Further, according to the study by the present inventors, in the above equations F1 and F2, the differential pressure is obtained by subtracting the saturation pressure determined by the physical properties of the refrigerant from the area ratio X which is a dimensionless number and the outlet side pressure Peo. Since the valve opening set pressure Y is used, it has been confirmed that it can be applied to a wide range of refrigerants without being limited to R1234yf.

That is, by setting the area ratio X and the valve opening set pressure Y so as to satisfy the above equations F1 and F2, the ejector type refrigerating cycle 10 that employs a wide range of refrigerants is suitable for both normal operation and low load operation. A refrigerant having a high flow rate can flow into the suction side evaporator 19.

In the above-described embodiment, as in the first embodiment, the refrigerant on the inlet side of the suction side decompression device 15 is guided to the outlet side of the suction side decompression device 15 by bypassing the suction side decompression device 15. Although the example in which the bypass passage 16 is arranged has been described, the arrangement of the bypass passage 16 is not limited to this.

That is, in the suction side decompression device 15, the portion where the refrigerant is actually decompressed is near the minimum passage cross-sectional area of the throttle passage 20a. Therefore, as shown in the modified example of FIG. 10, the bypass passage 16 is provided by connecting the upstream side of the minimum passage cross-sectional area of the throttle passage 20a and the downstream side of the minimum passage cross-sectional area of the throttle passage 20a. It may be shortened.

(Fifth Embodiment)
In this embodiment, an example in which the nozzle-side decompression device 25 is added to the ejector type refrigeration cycle 10 will be described with respect to the first embodiment as shown in the overall configuration diagram of FIG. The nozzle-side decompression device 25 is a variable throttle mechanism that decompresses the refrigerant branched at the branch portion 13 on the upstream side of the nozzle portion 14a. Further, the nozzle-side decompression device 25 functions as a flow rate adjusting device for adjusting the flow rate of the refrigerant flowing into the nozzle portion 14a.

The basic configuration of the nozzle-side decompression device 25 is a temperature-type expansion valve similar to the suction-side decompression device 15 described in the first embodiment. In the nozzle-side decompression device 25, the nozzle-side reference superheat degree KSH (in the present embodiment) in which the superheat degree SH of the refrigerant on the outlet side of the outflow-side evaporator 18 (that is, the suction refrigerant sucked into the compressor 11) is predetermined. The throttle opening is displaced so as to approach 1 ° C.).

Other ejector-type refrigeration cycles 10 are configured and operated in the same manner as in the first embodiment. Therefore, the same effect as that of the first embodiment can be obtained in the flow rate control valve 20 and the ejector type refrigeration cycle 10 of the present embodiment. Further, since the ejector type refrigeration cycle 10 of the present embodiment is provided with the nozzle-side decompression device 25, the liquid compression of the compressor 11 can be reliably suppressed.

(Sixth Embodiment)
In this embodiment, an example in which the intermediate pressure depressurizing device 26 is added to the ejector type refrigerating cycle 10 will be described with respect to the first embodiment as shown in the overall configuration diagram of FIG. The intermediate pressure depressurizing device 26 is a variable throttle mechanism that decompresses the refrigerant flowing out of the radiator 12 until it becomes an intermediate pressure refrigerant on the upstream side of the branch portion 13. Further, the intermediate pressure depressurizing device 26 functions as a flow rate adjusting device for adjusting the flow rate of the refrigerant flowing into the branch portion 13.

The basic configuration of the intermediate pressure decompression device 26 is a temperature type expansion valve similar to the suction side decompression device 15 described in the first embodiment. In the intermediate pressure depressurizing device 26, the superheat degree SH of the refrigerant on the outlet side of the outflow side evaporator 18 (that is, the suction refrigerant sucked into the compressor 11) is a predetermined nozzle side reference superheat degree KSH (in the present embodiment). The throttle opening is displaced so as to approach 1 ° C.).

Other ejector-type refrigeration cycles 10 are configured and operated in the same manner as in the first embodiment. Therefore, the same effect as that of the first embodiment can be obtained in the flow rate control valve 20 and the ejector type refrigeration cycle 10 of the present embodiment. Further, since the ejector type refrigeration cycle 10 of the present embodiment is provided with the intermediate pressure depressurizing device 26, the liquid compression of the compressor 11 can be reliably suppressed.

(7th Embodiment)
In this embodiment, an example in which the flow rate control valve 20 described in the above-described embodiment is applied to the ejector type refrigeration cycle 10a shown in the overall configuration diagram of FIG. 13 will be described.

In the ejector type refrigeration cycle 10a, the branch portion 13 and the outflow side evaporator 18 are abolished with respect to the ejector type refrigeration cycle 10 described in the first embodiment, and a gas-liquid separator 27 is provided. The gas-liquid separator 27 is a gas-liquid separator unit that separates the gas-liquid of the refrigerant flowing out from the diffuser unit 14d and stores the separated excess liquid-phase refrigerant.

Further, in the ejector type refrigeration cycle 10a, the inlet side of the nozzle portion 14a of the ejector 14 is connected to the outlet of the radiator 12. Further, the suction port side of the compressor 11 is connected to the gas-phase refrigerant outlet of the gas-liquid separator 27, and the refrigerant inlet 21a side of the flow rate adjusting valve 20 is connected to the liquid-phase refrigerant outlet of the gas-liquid separator 27. There is.

Other configurations of the ejector type refrigeration cycle 10a are the same as those of the ejector type refrigeration cycle 10 described in the first embodiment.

Next, the operation of the ejector type refrigeration cycle 10a in the above configuration will be described. When the air conditioning control device 40 operates the compressor 11, the high-temperature high-pressure refrigerant discharged from the compressor 11 flows into the radiator 12. The refrigerant flowing into the radiator 12 exchanges heat with the outside air blown from the cooling fan 12a, and is cooled and condensed. The refrigerant flowing out of the radiator 12 flows into the nozzle portion 14a of the ejector 14.

The refrigerant that has flowed into the nozzle portion 14a of the ejector 14 is isotropically depressurized by the nozzle portion 14a and is injected from the refrigerant injection port of the nozzle portion 14a. Then, due to the suction action of the injected refrigerant, the refrigerant flowing out of the suction side evaporator 19 is sucked from the refrigerant suction port 14c through the temperature sensitive passage 20b of the flow rate adjusting valve 20.

The injection refrigerant injected from the refrigerant injection port of the nozzle portion 14a and the suction refrigerant sucked from the refrigerant suction port 14c flow into the diffuser portion 14d. The refrigerant boosted by the diffuser unit 14d flows into the gas-liquid separator 27. The gas-phase refrigerant separated by the gas-liquid separator 27 is
It is sucked into the compressor 11 and compressed again. On the other hand, the liquid phase refrigerant separated by the gas-liquid separator 27 flows into the refrigerant inlet 21a of the flow rate adjusting valve 20.

At this time, as in the first embodiment, during normal operation, the refrigerant decompressed by the suction side decompression device 15 flows out from the evaporator side outlet 21b of the flow rate adjusting valve 20 and flows into the suction side evaporator 19. do. Further, during low load operation, the refrigerant decompressed by the suction side decompression device 15 and the refrigerant that has passed through the bypass passage 16 flow out from the evaporator side outlet 21b of the flow rate adjusting valve 20 and flow into the suction side evaporator 19. do.

The refrigerant flowing into the suction side evaporator 19 absorbs heat from the blown air blown by the indoor blower 18a and evaporates. As a result, the blown air blown by the indoor blower 18a is cooled. The refrigerant flowing out of the suction side evaporator 19 is sucked from the refrigerant suction port 14c.

Therefore, according to the ejector type refrigerating cycle 10a of the present embodiment, the blown air blown into the vehicle interior by the suction side evaporator 19 regardless of the load fluctuation, both in the normal operation and in the low load operation. Can be cooled. Then, the same effect as that of the ejector type refrigeration cycle 10 described in the first embodiment can be obtained.

That is, even if the flow rate adjusting valve 20 is applied to the ejector type refrigeration cycle 10a, the flow rate of the refrigerant flowing into the suction side evaporator 19 can be appropriately adjusted. In other words, according to the ejector type refrigerating cycle 10a of the present embodiment, since the flow rate adjusting valve 20 is provided, the flow rate of the refrigerant flowing into the suction side evaporator 19 is appropriately adjusted according to the load fluctuation of the cycle. be able to.

(Other embodiments)
The present invention is not limited to the above-described embodiment, and can be variously modified as follows without departing from the spirit of the present invention.

(1) In the above-described embodiment, an example in which the suction side decompression device 15, the bypass passage 16, and the variable throttle device 17 are integrated as the flow rate adjusting valve 20 has been described, but the present invention is not limited thereto. For example, even if the ejector type refrigeration cycles 10 and 10a are provided with the suction side decompression device 15, the bypass passage 16, and the variable throttle device 17 as separate components, the same effect can be obtained. Further, the branch portion 13, the ejector 14, and the like may be integrated with the flow rate adjusting valve 20.

(2) In the above-mentioned second embodiment, an example in which the pressure Psp of the spring chamber 17c is set to the refrigerant pressure on the outlet side of the throttle passage 20a has been described, but the present invention is not limited to this. For example, the spring chamber 17c may be communicated with the outside air, and the pressure Psp of the spring chamber 17c may be used as the outside air pressure. Further, the spring chamber 17c may be evacuated. In this case, as in the first embodiment, the seal member may be arranged in the gap between the inner wall surface of the first passage 16a and the valve body portion 17a.

(3) In the above-mentioned fourth embodiment, as shown in FIG. 7, an example in which the bypass passage 16 is arranged has been described, but the present invention is not limited to this. For example, it may be a bypass passage 16 having a relatively short distance extending from immediately before the throttle passage 20a to the downstream side of the throttle passage 20a. Further, the bypass passage 16 may be formed by cutting out a part of the inner peripheral surface of the portion of the body 21 that forms the throttle passage 20a.

(4) Each component device constituting the ejector type refrigeration cycle 10 is not limited to those disclosed in the above-described embodiment.

For example, in the above-described embodiment, an example in which an electric compressor is adopted as the compressor 11 has been described, but the compressor 11 is driven by a rotational driving force transmitted from a vehicle traveling engine via a pulley, a belt, or the like. An engine-driven compressor may be adopted. Furthermore, as an engine-driven compressor, a variable displacement compressor that can adjust the refrigerant discharge capacity by changing the discharge capacity, or a variable capacity compressor that can adjust the refrigerant discharge capacity by changing the operating rate of the compressor by engaging and disengaging the electromagnetic clutch. A fixed capacity compressor can be adopted.

Further, in the above-described embodiment, the detailed configuration of the radiator 12 is not mentioned, but the radiator 12 is a receiver-integrated condenser having a receiver unit (in other words, a liquid receiver) for storing the condensed refrigerant. May be adopted. Further, a so-called subcool type condenser having a supercooling section for supercooling the liquid phase refrigerant flowing out from the receiver section may be adopted.

Further, in the above-described embodiment, an example in which a three-way joint structure is adopted as the branch portion 13 has been described, but the branch portion 13 is not limited to this. For example, as the branch portion 13, a centrifugal separation type gas-liquid separator structure may be adopted as the branch portion 13. In this case, the relatively dry refrigerant on the turning center side is discharged to the nozzle portion 14a side of the ejector 14, and the relatively low dry refrigerant on the outer peripheral side is discharged to the refrigerant inlet 21a side of the flow rate adjusting valve 20. May be.

Further, in the above-described embodiment, the example in which the outflow side evaporator 18 and the suction side evaporator 19 are integrally configured has been described, but the outflow side evaporator 18 and the suction side evaporator 19 are configured separately. May be good. Then, the outflow side evaporator 18 and the suction side evaporator 19 may cool the different refrigerant target fluids in different temperature zones.

Further, in the above-described embodiment, an example in which R1234yf is adopted as the refrigerant has been described, but the refrigerant is not limited to this. For example, R134a, R600a, R410A, R404A, R32, R407C, etc. may be adopted. Alternatively, a mixed refrigerant or the like in which a plurality of types of these refrigerants are mixed may be adopted. Further, carbon dioxide may be adopted as the refrigerant to form a supercritical refrigeration cycle in which the pressure of the refrigerant on the high pressure side is equal to or higher than the critical pressure of the refrigerant.

(5) In each of the above-described embodiments, the ejector type refrigeration cycle 10 according to the present invention is applied to the vehicle air conditioner, but the application of the ejector type refrigeration cycle 10 is not limited to this. For example, it may be applied to a stationary air conditioner, a cold storage, and other cooling / heating devices.

(6) Further, the means disclosed in each of the above embodiments may be appropriately combined to the extent practicable. For example, the flow rate adjusting valve 20 described in the second to fourth embodiments may be applied to the ejector type refrigeration cycles 10 and 10a described in the fifth to seventh embodiments.

10, 10a Ejector type refrigeration cycle 12 Heat sink 14 Ejector 14a Nozzle part 14c Refrigerant suction port 15 Suction side decompression device (suction side decompression part)
16 Bypass passage 17 Variable aperture device (variable aperture mechanism)
19 Suction side evaporator 20 Flow control valve

Claims (9)

A compressor (11) that compresses and discharges the refrigerant,
A radiator (12) that dissipates heat from the refrigerant discharged from the compressor, and
The refrigerant is sucked from the refrigerant suction port (14c) by the suction action of the jet refrigerant jetted from the nozzle portion (14a) that depressurizes the refrigerant flowing out of the radiator, and the suction sucked from the jet refrigerant and the refrigerant suction port. Ejector (14) that boosts the pressure of the mixed refrigerant with the refrigerant,
The suction side decompression unit (15) that decompresses the refrigerant, and
A suction side evaporator (19) that evaporates the decompressed refrigerant in the suction side decompression unit and causes it to flow out to the refrigerant suction port side.
A bypass passage (16) that guides the refrigerant on the inlet side of the suction side decompression section to the inlet side of the suction side evaporator by detouring the suction side decompression section.
A variable throttle mechanism unit (17) for adjusting the flow rate of the refrigerant flowing through the bypass passage is provided.
The suction-side decompression unit changes the throttle opening so that the superheat degree (SH1) of the refrigerant on the outlet side of the suction-side evaporator approaches a predetermined standard superheat degree (KSH1).
The variable throttle mechanism unit has a function of opening and closing the bypass passage, and when the flow rate (Ge1) of the refrigerant flowing out from the suction side decompression unit is equal to or less than a predetermined reference flow rate (KGe1), the variable throttle mechanism unit is described. An ejector-type refrigeration cycle that opens a bypass passage. The variable throttle mechanism unit subtracts the outlet side pressure (Peo), which is the pressure of the refrigerant flowing out of the suction side evaporator, from the inlet side pressure (Pri), which is the pressure of the refrigerant on the inlet side of the suction side decompression unit. The ejector type refrigeration cycle according to claim 1, wherein the throttle opening degree is increased as the pressure difference (ΔP) is reduced. The ejector type according to claim 1, wherein the variable throttle mechanism portion increases the throttle opening degree as the inlet side pressure (Pri), which is the pressure of the refrigerant on the inlet side of the suction side decompression section, decreases. Refrigeration cycle. A compressor (11) that compresses and discharges the refrigerant,
A radiator (12) that dissipates heat from the refrigerant discharged from the compressor, and
The refrigerant is sucked from the refrigerant suction port (14c) by the suction action of the jet refrigerant jetted from the nozzle portion (14a) that depressurizes the refrigerant flowing out of the radiator, and the suction sucked from the jet refrigerant and the refrigerant suction port. Ejector (14) that boosts the pressure of the mixed refrigerant with the refrigerant,
The suction side decompression unit (15) that decompresses the refrigerant, and
A suction side evaporator (19) that evaporates the decompressed refrigerant in the suction side decompression unit and causes it to flow out to the refrigerant suction port side.
A bypass passage (16) for guiding the refrigerant on the inlet side of the suction side decompression section to the inlet side of the suction side evaporator by detouring the suction side decompression section is provided.
The suction side decompression unit is displaced according to the encapsulation space (52c) in which the temperature sensitive medium whose pressure changes with the temperature change of the refrigerant on the outlet side of the suction side evaporator is enclosed, and the pressure of the temperature sensitive medium. The throttle valve (51) is provided, and the throttle opening is changed so that the superheat degree (SH1) of the refrigerant on the outlet side of the suction side evaporator approaches a predetermined reference superheat degree (KSH1).
The value obtained by subtracting the saturation pressure of the temperature-sensitive medium at a predetermined reference medium temperature from the outlet-side pressure, which is the pressure of the refrigerant flowing out from the suction-side evaporator, is defined as the valve opening set pressure (Y), and the suction-side is defined as the valve opening set pressure (Y). When the ratio (Apt / Ax) of the minimum passage cross-sectional area (Apt) of the bypass passage to the maximum passage cross-sectional area (Aex) of the decompression section is defined as the area ratio X,
-170X + 3 ≧ Y
and,
Y ≧ -350X-9
Ejector type refrigeration cycle. A branch portion (13) for branching the flow of the refrigerant flowing out of the radiator is provided.
The inlet side of the nozzle portion is connected to one of the outlets of the branch portion (13).
The ejector-type refrigeration cycle according to any one of claims 1 to 4, wherein the inlet side of the suction side decompression portion is connected to the other outlet of the branch portion (13). The refrigerant is sucked from the refrigerant suction port (14c) by the suction action of the jet refrigerant jetted from the nozzle portion (14a) that depressurizes the refrigerant, and the mixed refrigerant of the jet refrigerant and the suction refrigerant sucked from the refrigerant suction port is sucked. A flow control valve applied to an ejector type refrigeration cycle (10, 10a) having an ejector (14) for boosting the pressure and a suction side evaporator (19) for evaporating the refrigerant and flowing it out to the refrigerant suction port side.
A suction side decompression unit (15) that changes the throttle opening so that the superheat degree (SH1) of the refrigerant on the outlet side of the suction side evaporator approaches a predetermined reference superheat degree (KSH1).
A bypass passage (16) that guides the refrigerant on the inlet side of the suction side decompression section to the outlet side of the suction side decompression section by bypassing the suction side decompression section.
A variable throttle mechanism unit (17) for adjusting the flow rate of the refrigerant flowing through the bypass passage is provided.
The refrigerant inlet side of the suction side evaporator is connected to the evaporator side outlet (21b) from which the decompressed refrigerant is discharged by the suction side decompression unit.
The variable throttle mechanism unit has a function of opening and closing the bypass passage, and the flow rate (Ge1) of the refrigerant flowing out from the suction side decompression unit to the refrigerant inlet side of the suction side evaporator is a predetermined reference flow rate (KGe1). ) A flow rate adjusting valve that opens the bypass passage when the value is as follows. The variable throttle mechanism unit subtracts the outlet side pressure (Peo), which is the pressure of the refrigerant flowing out from the suction side evaporator, from the inlet side pressure (Pri), which is the pressure of the refrigerant on the inlet side of the suction side decompression unit. The flow rate adjusting valve according to claim 6, wherein the throttle opening degree is increased as the pressure difference (ΔP) is reduced. The flow rate adjustment according to claim 6, wherein the variable throttle mechanism portion increases the throttle opening degree as the inlet side pressure (Pri), which is the pressure of the refrigerant on the inlet side of the suction side decompression section, decreases. valve. The refrigerant is sucked from the refrigerant suction port (14c) by the suction action of the jet refrigerant jetted from the nozzle portion (14a) that depressurizes the refrigerant, and the mixed refrigerant of the jet refrigerant and the suction refrigerant sucked from the refrigerant suction port is sucked. A flow rate adjusting valve applied to an ejector type refrigeration cycle (10, 10a) having an ejector (14) for boosting the pressure and a suction side evaporator (19) for evaporating the refrigerant and causing the refrigerant to flow out to the refrigerant suction port side.
A suction side decompression unit (15) that changes the throttle opening so that the superheat degree (SH1) of the refrigerant on the outlet side of the suction side evaporator approaches a predetermined reference superheat degree (KSH1).
A bypass passage (16) for guiding the refrigerant on the inlet side of the suction side decompression section to the outlet side of the suction side decompression section by detouring the suction side decompression section is provided.
The suction-side decompression unit is displaced according to the encapsulation space (52c) in which the temperature-sensitive medium whose pressure changes with the temperature change of the refrigerant on the outlet side of the suction-side evaporator is enclosed, and the pressure of the temperature-sensitive medium. Has a throttle valve (51)
The refrigerant inlet side of the suction side evaporator is connected to the evaporator side outlet (21b) from which the decompressed refrigerant is discharged by the suction side decompression unit.
The value obtained by subtracting the saturation pressure of the temperature-sensitive medium at a predetermined reference medium temperature from the outlet side pressure, which is the pressure of the refrigerant flowing out from the suction side evaporator, is defined as the valve opening set pressure (Y), and the suction side. When the ratio (Apt / Ax) of the minimum passage cross-sectional area (Apt) of the bypass passage to the maximum passage cross-sectional area (Aex) of the decompression section is defined as the area ratio X,
-170X + 3 ≧ Y
and,
Y ≧ -350X-9
Flow control valve.

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