JPS6156438B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention mainly provides a refrigeration system capable of air conditioning or air conditioning, specifically a refrigeration system that is equipped with a compressor, controls the capacity of the compressor, and performs refrigeration operation with improved cooling or heating capacity. refrigeration equipment.

Conventionally, in a refrigeration system, a rotary compressor is used as the compressor, and a cylinder having a suction port and a discharge port is provided with an injection port that opens into a pumping chamber between the ports. The refrigerant circuit connected to the suction port and discharge port of the system is equipped with two heat exchangers serving as a condenser and an evaporator, as well as a gas-liquid separator located between these heat exchangers. A gas injection passage is connected to the gas region of the separator, the passage is communicated with the injection extraction port, and the intermediate pressure gas refrigerant separated by the gas-liquid separator is injected into the pumping chamber of the cylinder. A system for increasing the capacity of the refrigeration system by increasing the capacity of the compressor above the rated capacity is known, for example, as shown in Japanese Patent Laid-Open No. 54-6162.

However, in this conventional device, the angle between the center of the injection port and the center of the blade relative to the rotation center of the rotor is 15 to 60 degrees.
After the internal contact point of the rotor to the cylinder chamber passes through the suction port, in other words, the suction stroke is completed and the compression stroke begins, the injection exit port opens and the intermediate After the gas refrigerant at the pressure is injected and the internal pressure of the cylinder becomes higher than the injection pressure of the gas refrigerant to be injected,
The injection port is then closed.

As a result, the angle from the start to the end of injection, that is, the injection angle, is small, and the amount of injection is reduced accordingly.Moreover, the gas refrigerant that has been injection flows back until the injection port is closed.
This resulted in a decrease in the amount of injection, resulting in the problem that sufficient capacity could not be increased.Furthermore, the internal pressure in the cylinder chamber at the start of the compression stroke was the suction pressure, even though intermediate pressure gas refrigerant was being injected. First, there was a problem in that the energy efficiency by injection extraction could not be sufficiently improved.

An object of the present invention is to effectively utilize the gas refrigerant to be injected by forming the injection port opening into the cylinder chamber of the compressor at a predetermined position based on the flow rate of the intermediate pressure gas refrigerant to be injected. This makes it possible to sufficiently increase capacity and also sufficiently improve energy efficiency.

The configuration of the present invention is such that the injection port of a compressor equipped with an injection port is connected to a first circular arc at a rotor position where the internal pressure of the cylinder chamber becomes the injection pressure during the compression stroke of the rotor, and a cylinder of the rotor. An internal point of contact with the chamber passes through the suction port and is located backward in the rotational direction corresponding to the time period in which the gas refrigerant injected from the injection exit port reaches the suction port, relative to the position where the suction port is closed. The injection exit port is provided at the intersection of the displaced rotor position with the second circular arc on the discharge port side, and the injection exit port is configured such that it begins to open at the rotor position of the second circular arc and closes at the rotor position of the first circular arc, and the gas refrigerant In addition, the internal pressure in the cylinder chamber at the start of the compression stroke is immediately raised to the injection pressure, making it possible to operate the compressor with high energy efficiency.

Embodiments of the refrigeration system of the present invention will be described below based on the drawings.

The basic structure of the refrigeration system of the present invention is as schematically shown in FIG. 1, and includes a rotary compressor 1,
A refrigerant circuit 8 having two heat exchangers 2, 3, an expansion mechanism 4, 5 divided into two, a gas-liquid separator 6 and an accumulator 7 provided at an intermediate position between these expansion mechanisms 4, 5, and the gas-liquid separator. Extending from the gas region of vessel 6,
The compressor 1 is provided with an injection passage 9 connected to an injection exit port (to be described later), and by injecting intermediate pressure gas refrigerant from the injection passage 9 into the pumping chamber of the compressor 1, capacity is increased. It was done as expected.

In the circuit shown in FIG. 1, the refrigerant circuit 8 is equipped with a four-way switching valve 10, and by switching the switching valve 10, a cooling cycle indicated by a solid line arrow and a heating cycle indicated by a dotted line arrow are formed. , an indoor heat exchanger 2 provided on the indoor side among the heat exchangers 2 and 3;
In the cooling cycle, the evaporator is used for cooling, and in the heating cycle, the condenser is used for heating.

It goes without saying that the outdoor heat exchanger 3 provided on the outdoor side functions as a condenser in the cooling cycle and as an evaporator in the heating cycle.

Further, the expansion mechanisms 4 and 5 are constructed by connecting capillary reach tubes 4a and 5a, which act during cooling, and capillary reach tubes 4b, 5b, which act during heating, in parallel, respectively. , each of the capillary reach tubes 4a,
5a, 4b, 5b have check valves 11, 1, respectively.
2, 13, and 14 are connected in series.

Further, in the above configuration, the expansion mechanisms 4, 5
Capillary reach tubes 4a, 5a, 4 constituting
By adjusting the length of the capillary reach tube 4a or 5b located at the front stage of the gas-liquid separator 6 with respect to the capillary reach tube 5a or 4b located at the rear stage among the capillary reach tubes 5a and 5b, the gas-liquid separator 6 The pressure of the refrigerant in the gas-liquid separator 6 is determined, and the amount of intermediate-pressure gas generated in the gas-liquid separator 6 can be adjusted.

As shown in FIG. 2, the compressor 1 includes a closed housing 20 consisting of a cylindrical housing body 20a, a housing top 20b and a housing bottom 20c, and a rotor 21a, a drive shaft 21b, a stator 21c, etc. A motor 21 consisting of
and a cylinder block 22 to be described later,
A drive shaft 2 fixed to the rotor 21a of the motor 21
1b through the cylinder block 22,
Rotor 23 installed inside the cylinder block 22
The cylinder block 22 includes a cylinder body 24 provided with a cylinder chamber 24a in the center thereof having a circular cylinder wall concentric with the axis of the drive shaft 21b, and the cylinder chamber 24a. It consists of a front head 25 and a rear head 26 having a closed plane, and the rotor 23, which rotates eccentrically with respect to the axis of the drive shaft 21b, is housed in the cylinder chamber 24a.

The compressor 1 shown in FIGS. 2 to 4 is a stationary blade rotary compressor, and the rotor 23 includes a cam 23a having a circular outer circumferential surface extending integrally from the drive shaft 21b; and a roller 23b that fits around the outer periphery of the cam 23a, and makes the center O ₄ of the cam 23a eccentric to the axis O ₃ of the drive shaft 21b, in other words, the center O ₃ of the cylinder chamber 24a. The height of the roller 23b is approximately equal to the height of the cylinder chamber 24a, in other words, the length between the planes of the respective heads 25 and 26, and its outer peripheral surface is brought into contact with the cylinder wall. , the internal contact point _O1 of the roller 23b to the cylinder wall moves in the circumferential direction along the cylinder wall.

A blade 27 having a sealing surface that comes into close contact with the outer peripheral surface of the roller 23b is attached to the cylinder body 24, and an opening is opened into the cylinder chamber 24a at a position close to both sides of the blade 27. A suction port 28 and a discharge port 29 are provided, and each of these ports 28, 2
An injection exit port 30 is provided at an intermediate position (to be described later) of 9, and the intake port 28
The roller 23 is provided between the roller 23 and the discharge port 29.
A pumping chamber 31 is defined by an internal contact point O ₁ of the blade 27 and a contact point O ₂ of the blade 27 with the roller 23b. Further, the blade 27 has a width equal to the axial length of the roller 23b, as shown in FIG.
A pair of blade springs 32 are slidably supported in guide grooves formed in the cylinder body 24 and have one end supported by the cylinder body 24.
The blade 27 is urged to protrude into the cylinder chamber 24a, and the sealing surface of the blade 27 is always in contact with the outer peripheral surface of the roller 23b.

Further, the suction port 28 is provided horizontally on one side of the cylinder body 24, penetrating the cylinder wall, and the discharge port 29 is provided horizontally through the cylinder wall.
is provided in the front head 25 vertically through the plane, and at the opening of the discharge port 29 to the sealed housing 20,
A discharge valve 33 is provided with one end supported on the front head 25.

Further, an assembly of connecting pipes 34 and 35 is connected to the suction port 28 via a joint pipe 36 as shown in FIG. A suction pipe 8a extending from the outlet side of the accumulator 7 is connected to the discharge port 29, which opens into the housing 20 via the discharge valve 33, and the gas refrigerant discharged from the discharge port 29 is , and is discharged through the discharge pipe 8b of the refrigerant circuit 8, which is connected to the housing top 20b.

In FIG. 2, 37 is a bracket that fixes the compressor 1, 38 is a terminal that supplies power to the stator 21c of the motor 21, 39 is a terminal guard, and 40 is a terminal cover.
Further, 41 is a balance weight fixed to the rotor 21a of the motor 21, and 42 is a magnet attached to the housing bottom 20c, which removes iron powder etc. mixed into the lubricating oil filled in the bottom of the housing 20. It is. Also, 43 is
An oil pump attached to the lower end of the drive shaft 21b,
The lubricating oil is discharged into an oil passage 44 provided at the center of the drive shaft 21b. The oil passage 44 also includes a cam 23 that constitutes the rotor 23.
A supply path 44a that supplies the lubricating oil to the oil chambers 23c formed above and below the cam 23a, and the lubricating oil is provided between the front head 25, the rear head 26, and the drive shaft 21b, which are located above and below the cam 23a. It has a supply path 44b for supplying oil.

A muffler 45 covers the upper part of the front head 25 and is used to reduce noise caused by refrigerant discharged from the discharge port 29.

Next, the injection port 30 of the compressor 1 in the refrigeration system configured as above will be explained.

The injection extension port 30 is mainly formed in the rear head 26 or the front head 25 so as to open in a direction perpendicular to the cylinder chamber 24a. It communicates with the injection passage 9 via the injection passage 9.

The communication passages 50, 51 and the injection passage 9 are connected by attaching a connecting pipe 52 passing through the housing body 20a to the opening of the communication passage 50 that opens to the cylinder body 24.
This is done by connecting the injection passage 9 to this connecting pipe 52 via a joint pipe 53.

The formation position of the injection port 30 formed as described above will now be explained.

In the compressor 1, discharge is performed once for each rotation of the rotor 23. Looking at one pumping chamber 31, as shown in FIGS. 5 to 8, the rotor 23
It is designed to be discharged in two rotations.

That is, as shown in FIG. 5, if the angular position where the internal contact point O ₁ of the rotor 23 to the cylinder wall is located at the contact point O ₂ of the blade 27 to the rotor 23 is the base point 0°, then at this base point position , the volume of the pumping chamber 31 is zero, and when the internal contact point O ₁ enters the opening position of the suction port 28 from this base position, the pumping chamber 3
1 increases, and gas refrigerant is sucked in from the suction port 28. Then, as shown in FIG. 7, the rotor 23 rotates 380 degrees from the base position, the internal contact point _O1 passes through the suction port 28, and suction ends when the suction port 28 is closed. At this time, the pumping chamber 31 has a maximum volume. Thereafter, the volume of the pumping chamber 31 decreases as the rotor 23 rotates to compress the sucked gas refrigerant, and the discharge valve 33 opens at a position where the rotor 23 has rotated, for example, 570 degrees with respect to the base position. , starts discharging the compressed high-pressure gas refrigerant, and when the internal contact point _O1 returns to the position shown in FIG. 5, that is, the rotor 23 moves from the base position.
Dispensing ends when it rotates 720 degrees.

In the compressor 1 that operates as described above, the injection port 30 is opened and closed by the rotor 23 due to eccentric rotation of the rotor 23. To determine the position of the injection port 30, As shown in FIG. 4, in the compression stroke, the rotor position is just before the angular position where the discharge valve 33 opens and the internal pressure of the pumping chamber 31 becomes the injection pressure. is not limited to the position where the pressure is equal to the injection pressure, but also includes a position slightly lower than the injection pressure.) and the inner contact point O ₁
The gas refrigerant that is injected from the injection exit port 30 passes through the suction port 28 and the port 28 is closed.
The injection port 30 is set at the discharge port side intersection K with the second arc B of the rotor position displaced backward in the rotational direction corresponding to the time to reach the suction port 28, and the injection exit port 30 is set at the rotor position of the second arc B. It begins to open and finishes closing at the rotor position of the first circular arc A.

That is, in the suction stroke, at the rotor position (FIG. 6) just before the injection port 30 begins to open by the rotor 23 and the rotation of the rotor 23, the internal contact point _O1 passes through the suction port 28, Rotor position with the port 28 closed (Fig. 7)
The angle with respect to the rotation center O of the rotor 23 is defined as a return angle θ, and when the rotor position (FIG. 7) where the internal contact point O ₁ closes the suction port 28 and the rotation of the rotor 23, the injection exit port 3
0 is the closed rotor position (Fig. 8) and the angle with respect to the rotation center O is the injection angle α, Pi is the injection pressure, Ps is the suction pressure, and the radius of the rotor 23 is R. As such, the injection exit port 30
It sets the position of.

In the above equation, C is the flow coefficient, g is the acceleration of gravity, and γ is the specific weight of the gas refrigerant.
The denominator is _the time t ₁ during which the rotor 23 rotates through the return angle θ. Therefore, in the previous equation, t ₁ /t ₂ =1 is preferable, but as mentioned above, t ₁ /t ₂ <1 (however, t ₁ /t ₂ ≒
1).

Further, in the above configuration, the rotor 23
is formed by a cam 23a and a roller 23b, and an oil chamber 23c is located between the cam 23a and the roller 23b, and high-pressure lubricating oil is supplied thereto. is preferably located at a position radially outward from an imaginary circle drawn with the drive shaft 21b as the center and a radius having a dimension extending to the inner surface of the roller 23b on a line connecting the center to the inner contact point _O1 , and The diameter of the injection port 30 is smaller than the width of the roller 23b in the radial direction, and is normally about 1.8 mm. In addition, the injection pressure Pi is set in relation to the bore diameter, but is usually 7 to 10
Kg/ ^cm2 .

By the way, the diameter of the injection port 30 is
1.8 mm and the injection extension pressure Pi is 8Kg/cm ² , the return angle θ is approximately 50 degrees, and the injection extension angle α is approximately 130 degrees.
The injection port 30 is opened within a total range of 180 degrees, and injection is performed.

As described above, the injection port 30
is open to the pumping chamber 31 when the rotor 23 is within the range of the return angle θ and the injection angle α, and
In the intermediate-pressure gas refrigerant, injection starts at the starting point of the return angle θ in the suction stroke, and ends at the ending point of the injection exit angle α.

Therefore, when the rotor 23 is at the return angle θ, both the suction port 28 and the intermediate pressure port 51 are opened in the pumping chamber 31, so that the injected gas refrigerant is However, the return angle θ is set based on the time the gas refrigerant injected from the injection exit port 30 reaches the suction port 28. The suction port 28 is closed before the fluid flows out.

Therefore, at the return angle θ, all of the injected gas refrigerant can be effectively used to increase the capacity, and the internal pressure of the chamber 31 at the end of the suction stroke can be brought to the injection pressure Pi.

Further, when the rotor 23 passes through the return angle θ, the suction stroke ends, and the intake stroke enters the injection angle α and shifts to the compression stroke. This injection angle α
In this case, only the injection port 30 opens into the pumping chamber 31, and the injection port 30 is
Since the chamber 31 is closed at the rotor position where the internal pressure is approximately equal to the injection exit pressure, all of the injection gas refrigerant can be effectively used without flowing back into the injection exit port 30. The total amount of gas refrigerant that is injected at the angle θ is the same as that of the pumping chamber 31.
The injection efficiency can be improved to 99.6%, and the capacity of the compressor 1 can be increased, making it possible to increase the capacity by 18 to 25%.

Moreover, the chamber 31 at the start of the compression stroke
The internal pressure of can be made into the injection pressure Pi, so
Energy efficiency can also be improved, and highly efficient compression operation becomes possible.

Next, the fact that capacity is increased by injection of intermediate pressure gas will be explained with reference to the Mollier diagram shown in FIG.

In FIG. 9, ~ indicates the refrigeration cycle, indicates the high-pressure gas refrigerant discharged from the discharge port 29 of the compressor 1, indicates the high-pressure liquid refrigerant at the outlet side of the heat exchanger 2 or 3 serving as the condenser, and indicates the previous stage side. The liquid-gas mixed refrigerant that has been reduced to an intermediate pressure by the expansion mechanism 4 or 5 is the intermediate-pressure liquid refrigerant that has been separated by the gas-liquid separator 6. The liquid-gas mixed refrigerant indicates the state of the low-pressure gas refrigerant sucked from the suction port 28 of the compressor 1 on the outlet side of the heat exchanger 3 or 2 serving as the evaporator, or the gas-liquid separator. 6 shows an intermediate pressure gas refrigerant separated at 6.

Therefore, at the time of injection, the intermediate pressure gas refrigerant separated by the gas-liquid separator 6 is injection-extracted into the pumping chamber 31. When the circulation amount of refrigerant returning to the suction port 28 of the compressor 1 through the side expansion mechanism 5 or 4 and the heat exchanger 3 or 2 serving as an evaporator is G, the discharge port 2 of the compressor 1
The discharge amount of the high pressure gas refrigerant discharged from G
+g, and the discharge amount increases by the injection amount g.

Therefore, during heating, the amount of refrigerant flowing through the indoor heat exchanger 2, which performs a condensing action, increases, increasing the heating capacity. The liquid refrigerant at intermediate pressure is on the saturated liquid line as shown in the Mollier diagram of FIG. 9, and the latent heat of vaporization increases by Δi, and the cooling capacity can also be increased.

The embodiment described above uses a stationary blade type rotary compressor, but
A rotary blade type rotary compressor may also be used.

As described above, the present invention provides the cylinder chamber 2 of the compressor 1.
The position of the injection exit port 30 that opens at 4a is set at the first arc A of the rotor position where the internal pressure of the cylinder chamber 24a becomes the injection pressure during the compression stroke of the rotor 23, and the internal contact point of the rotor 23 to the cylinder chamber 24a. However, the gas refrigerant that is injected from the injection exit port 30 passes through the suction port 28 and closes the suction port 28 .
The injection exit port 30 is provided at the intersection point on the discharge port side with the second circular arc B of the rotor position displaced rearward in the rotational direction corresponding to the time up to
Since it started opening at the rotor position of arc B and ended closing at the rotor position of the first arc A,
All of the gas refrigerant that is injected can be used effectively, and the injection efficiency can be improved to nearly 100%, making it possible to increase the capacity to a high level.

Moreover, the cylinder chamber pressure at the start of the compression stroke is
Since the injection pressure can be maintained, energy efficiency can also be improved, allowing energy-saving refrigeration operation.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram showing an embodiment of the present invention;
2 is a longitudinal sectional view of the compressor used in the embodiment shown in FIG. 1, FIG. 3 is a sectional view taken along the line shown in FIG. 5 to 8 are explanatory diagrams showing the suction and compression strokes of the compressor, and FIG. 9 is a Mollier diagram. 1... Compressor, 2, 3... Heat exchanger, 6... Gas-liquid separator, 8... Refrigerant circuit, 9... Injection passageway, 23... Rotor, 24a... Cylinder chamber, 28... Suction Port, 29...Discharge port,
30... Injection port.

Claims (1)

[Claims] 1 Suction port 28 that opens into the cylinder chamber 24a
and a discharge port 29, and an injection exit port 30 between the suction port 28 and the discharge port 29, and a rotor 23 in the cylinder chamber 24a.
In a refrigeration system equipped with a rotary compressor 1 incorporating a rotary compressor 1 and an injection passage 9 communicating with the injection exit port 30, the injection exit port 30 is connected to the internal pressure of the cylinder chamber 24a during the compression stroke of the rotor 23. a first circular arc A at the rotor position where is the injection pressure;
When the internal contact point of the rotor 23 to the cylinder chamber 24 a passes through the suction port 28 and closes the suction port 28 , the gas refrigerant injected from the injection exit port 30 passes through the suction port 28 . The second circular arc B of the rotor position displaced backward in the rotational direction corresponding to the time to reach
The refrigeration system is characterized in that the injection port 30 is provided at the intersection point on the discharge port side with the injection port 30, and the injection port 30 begins to open at the rotor position of the second circular arc B and finishes closing at the rotor position of the first circular arc A.