JP3481138B2 - Refrigeration cycle with bypass line - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating cycle with a bypass pipe, in which an evaporator normally used for cooling can be used for auxiliary heating as needed.

[0002]

2. Description of the Related Art In an automobile air conditioner, a general refrigeration cycle is used for cooling, and warmed engine cooling water is used for heating.

However, when the efficiency of an engine is improved, such as in a gasoline-injection engine of recent years, the temperature of the cooling water does not rise as much as before, so that the heating temperature does not rise sufficiently in winter.

Therefore, conventionally, as shown in FIG. 9, for example, the high-pressure refrigerant gas sent from the compressor 1 of the refrigeration cycle is sent to the evaporator 4 inside the passenger compartment without passing through the condenser 2 outside the passenger compartment. An evaporator 4 with a bypass pipe line 5
There is a system that uses heat as an auxiliary heating by exchanging heat to remove sensible heat.

Reference numeral 3 is an expansion valve, 10 is a liquid tank for temporarily storing high-pressure refrigerant liquid, 7 is a check valve, and 8 is a high-pressure refrigerant sent from the compressor 1 to the condenser 2 or bypass. A pipe line switching valve for switching between passage through the pipe line 5 and a constant differential pressure valve 9 that acts as an expansion valve when the refrigerant flows through the bypass pipe line 5.

[0006]

However, in the conventional refrigeration cycle with a bypass line as described above, since the refrigerant does not pass through the liquid tank 10 in the auxiliary heating mode, the amount of circulating refrigerant becomes constant. Since the amount of the refrigerant cannot be controlled according to the load and the like, there is a drawback that heating corresponding to the situation is not performed.

Therefore, in the present invention, in the refrigerating cycle with a bypass pipe line in which heat can be exchanged for heating in the evaporator without passing the refrigerant through the condenser, the amount of circulating refrigerant is controlled according to the load or the like. In addition, it is an object of the present invention to provide a refrigeration cycle with a bypass pipe that can perform heating suitable for the situation.

[0008]

In order to achieve the above object, the refrigerating cycle with a bypass line of the present invention uses a refrigerant,
After the refrigerant is compressed by the compressor and then condensed by the condenser, the refrigerant is not passed through the refrigeration cycle in which it is sent to the evaporator while being adiabatically expanded by the expansion valve, evaporated and then returned to the compressor. Along with a bypass pipeline for sending from the compressor to the evaporator, an accumulator for temporarily storing low-pressure refrigerant liquid is connected between the outlet of the evaporator and the inlet of the compressor. Then, the circulation amount of the refrigerant is controlled in the accumulator when the refrigerant circulates in the bypass pipe line without passing through the condenser.

It is to be noted that the expansion for adiabatic expansion of the refrigerant sent from the compressor and sent to the evaporator through the bypass pipe line without passing through the condenser before entering the evaporator. A valve may be provided.

Further, the refrigerant fed into the accumulator after passing through the evaporator without passing through the condenser,
An expansion valve may be provided for performing adiabatic expansion before entering the accumulator.

A heat exchanger for exchanging heat between the refrigerant and the heat emitted from the energy source of the vehicle equipped with the refrigeration cycle may be incorporated in the accumulator.

Also, a heat exchanger for exchanging heat between the heat generated from the energy source of the automobile equipped with the refrigeration cycle and the refrigerant is adjacent to the accumulator and is connected to the refrigerant pipe line on the upstream side of the accumulator. It may be plugged and connected.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings. FIG. 1 schematically shows the entire configuration of a refrigeration cycle used in an automobile air conditioner according to a first embodiment of the present invention, where 1 is a compressor, 2 is a condenser arranged outside the vehicle compartment, and 3 is a condenser. The expansion valve 4, an evaporator arranged in an air duct communicating with the vehicle interior, and an accumulator 6 for temporarily storing a low-pressure refrigerant form a normal refrigeration cycle.

As the expansion valve 3, in addition to a general mechanical expansion valve, an orifice tube (for example, a diameter of 1.6 m) is used.
m, length 33 mm), a supercooling control valve that keeps the supercooling degree constant by increasing the valve opening degree when the supercooling degree on the inlet side becomes large, or an electrically controlled expansion valve or the like can be used. .

In addition to the normal refrigeration cycle described above, in order to perform auxiliary heating using the evaporator 4, the high pressure refrigerant gas sent from the compressor 1 is passed through the evaporator 4 without passing through the condenser 2. The bypass pipe line 5 for sending in is also installed.

Reference numeral 7 indicates a check valve, and 8 indicates whether the high-pressure refrigerant sent from the compressor 1 is directed to the condenser 2 or the bypass line 5.
A pipe line switching valve (three-way valve) 9 for switching between passing through and a constant pressure differential valve for decompression that acts as an expansion valve when the refrigerant flows through the bypass pipe line 5.

As the constant differential pressure valve 9, the control differential pressure is controlled in two stages (for example, 13 atm and 7 atm) by a solenoid or the like.
Alternatively, a switchable type of three or more stages may be used, and an electric control valve may be used.

In the refrigerating cycle with a bypass line according to the embodiment thus configured, the compressor 1 is used during cooling.
The conduit switching valve 8 is set so that the high-pressure refrigerant sent out from the condenser 2 is entirely sent to the condenser 2 without going to the bypass conduit 5. Then, the evaporator 4 in the vehicle compartment acts as an original evaporator, and cooling is performed by heat exchange between the surrounding air and the refrigerant therein.

During the auxiliary heating, the line switching valve 8 is switched, and the high-pressure refrigerant sent from the compressor 1 does not go to the condenser 2 but all flows in the bypass line 5 and the evaporator 4 to the accumulator. It is set so as to be returned to the compressor 1 via 6.

Then, when the refrigerant expanded and decompressed by passing through the constant differential pressure valve 9 passes through the evaporator 4, heat exchange is performed to remove the sensible heat given in the compressor 1 from the refrigerant, and the evaporation is performed. The container 4 acts as a radiator for heating.

FIG. 2 shows the characteristics of the cycle at that time by a solid line. Is the outlet of the compressor 1, is the inlet of the evaporator 4, is the outlet of the evaporator 4, is the inlet of the accumulator 6, and is the inlet of the compressor 1.
The space between the two is expansion, the space between-is the heat radiation, and the space between-is the compression.

Thus, when the refrigerant passes through the bypass line 5 and is in the auxiliary heating mode, the accumulator 6 exists in the refrigerant circulation line. Therefore, when the load is small, a large amount of refrigerant is stored in the accumulator 6, and when the load is large, the amount of refrigerant discharged from the accumulator 6 is large, and the circulating refrigerant amount changes according to the load. As a result, it is possible to obtain the heating effect corresponding to the need.

FIG. 3 shows a refrigerating cycle with a bypass line according to a second embodiment of the present invention. For example, a second expansion valve 19 composed of a constant differential pressure valve for decompression, an evaporator 4 and an accumulator 6 are provided. It is provided between and. No constant differential pressure valve (expansion valve) is provided between the compressor 1 and the evaporator 4. Other configurations are the same as those in the first embodiment.

In the refrigerating cycle with the bypass pipe constructed as described above, when the refrigerant is flown to the bypass pipe 5 side, as shown in the characteristic diagram of FIG.
Functions as a condenser in the case of a general refrigeration cycle,
The heat is dissipated between − to obtain the heating effect.

Also in this case, the circulation amount of the refrigerant is controlled according to the load by the accumulator 6 existing in the refrigerant circulation line, and the heating effect corresponding to the need can be obtained.

FIG. 5 shows a refrigerating cycle with a bypass line according to a third embodiment of the present invention, in which a constant differential pressure valve 9 is inserted between the line switching valve 8 and the evaporator 4. In addition, a second expansion valve 19 is inserted and connected between the evaporator 4 and the accumulator 6.

As a result, the expansion of the refrigerant during heating is performed at two locations, the constant differential pressure valve 9 functioning as an expansion valve and the second expansion valve 19. Therefore, the pressure of the refrigerant passing through the evaporator 4 is lower than in the second embodiment, and the pressure resistance of the evaporator 4 can be set low.

Reference numeral 20 is an open / close valve that is opened to bypass the refrigerant from the second expansion valve 19 in the normal cooling mode in which the refrigerant does not flow in the bypass conduit 5. Other configurations are the same as those in the first embodiment.

The second expansion valve 19 may be of a type that functions as a constant differential pressure valve, but when the pressure on the outlet side exceeds a predetermined pressure (for example, 4 atm), the valve opening degree is reduced and the valve on the outlet side is reduced. A pressure control valve that keeps the pressure below a certain level, a variable pressure control valve that can change the set pressure with electromagnetic force,
Alternatively, an electric control valve or the like may be used.

Further, as the constant differential pressure valve 9 provided in the bypass line 5, when the pressure on the outlet side exceeds a predetermined pressure (for example, 10 atm), the valve opening is reduced to keep the pressure on the outlet side below a certain level. A pressure regulating valve to be maintained or a variable pressure regulating valve whose set pressure can be varied by electromagnetic force may be used (same in other embodiments), and in that case, the second expansion valve 19 As the above, an orifice whose channel cross-sectional area is simply reduced may be used.

FIG. 6 shows a refrigeration cycle with a bypass pipe according to a fourth embodiment of the present invention. In the same refrigeration cycle as that of the third embodiment, the refrigeration cycle is discharged from an automobile engine, motor or battery. A heat exchanger 21 for exchanging the generated heat with the refrigerant is added to the accumulator 6. 22 is a flow rate control valve for controlling the flow rate of water or the like, which is a medium for transmitting waste heat.

By doing so, the heat given to the refrigerant from the heat exchanger 21 in the accumulator 6 can also be used for heating, and when the refrigerant flows to the side of the bypass pipe line 5, as shown in FIG. As shown in the characteristic diagram, a large amount of heat is dissipated in the evaporator 4 between and, and a higher heating effect can be obtained.

Also in this case, the circulation amount of the refrigerant is controlled by the accumulator 6 existing in the refrigerant circulation line in accordance with the load, and the heating effect corresponding to the need can be obtained.

FIG. 8 shows a refrigeration cycle with a bypass pipe according to a fifth embodiment of the present invention, which is heat for exchanging heat released from an automobile engine, motor or battery with a refrigerant. The exchanger 21 is arranged between the second expansion valve 19 and the accumulator 6, and it is possible to obtain the same effect as that of the third embodiment.

Further, the conduit switching valve 8 is functionally divided into two opening / closing valves 28, 29, and the three opening / closing valves 28, 29, 20 are combined with the opening / closing valve 20 for bypassing the refrigerant. I am trying to configure them in blocks.

[0036]

According to the present invention, a bypass pipe line for sending the refrigerant from the compressor to the evaporator without passing through the condenser is provided, and an accumulator for temporarily storing the low-pressure refrigerant liquid is provided. By connecting between the outlet of the evaporator and the inlet of the compressor, the refrigerant circulation amount when the refrigerant circulates in the bypass pipeline without passing through the condenser is controlled in the accumulator. Even when performing heat exchange for heating in the evaporator without passing the refrigerant through the condenser, the circulating refrigerant amount can be appropriately controlled according to the load, etc., and the heating effect corresponding to the situation can be obtained. .

[Brief description of drawings]

FIG. 1 is a schematic diagram of an overall configuration of a refrigeration cycle with a bypass line according to a first embodiment of the present invention.

FIG. 2 is a characteristic diagram of the first embodiment of the present invention.

FIG. 3 is a schematic diagram of an overall configuration of a refrigeration cycle with a bypass line according to a second embodiment of the present invention.

FIG. 4 is a characteristic diagram of the second embodiment of the present invention.

FIG. 5 is a schematic diagram of an overall configuration of a refrigeration cycle with a bypass line according to a third embodiment of the present invention.

FIG. 6 is a schematic diagram of the overall configuration of a refrigeration cycle with a bypass line according to a fourth embodiment of the present invention.

FIG. 7 is a characteristic diagram of a fourth embodiment of the present invention.

FIG. 8 is a schematic diagram of the overall configuration of a refrigeration cycle with a bypass line according to a fifth embodiment of the present invention.

FIG. 9 is a schematic view of a conventional refrigeration cycle with a bypass line.

[Explanation of symbols]

1 compressor 3,19 Expansion valve 4 evaporator 5 Bypass pipeline 6 Accumulator 8 conduit switching valve 9 Constant differential pressure valve (expansion valve) 21 heat exchanger

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Claims (4)

(57) [Claims] 1. A refrigeration cycle in which a refrigerant is compressed by a compressor and then condensed by a condenser, and then sent to an evaporator while being adiabatically expanded by an expansion valve to be evaporated and then returned to the compressor, Along with a bypass pipe for sending the refrigerant from the compressor to the evaporator without passing through the condenser, an accumulator for temporarily storing a low-pressure refrigerant liquid is provided with the outlet of the evaporator and the compression. Connected to the inlet of the machine, so that the circulation amount of the refrigerant is controlled in the accumulator when the refrigerant circulates in the bypass pipe without passing through the condenser, and further, the condenser
Through the evaporator without passing through the accumulator
The refrigerant sent to the
A refrigeration cycle with a bypass line, which is provided with an expansion valve for thermal expansion . 2. An expansion for adiabatically expanding the refrigerant, which is sent from the compressor and is sent to the evaporator through the bypass line without passing through the condenser, before entering the evaporator. The refrigeration cycle with a bypass line according to claim 1, wherein a valve is provided. 3. The bypass according to claim 1 or 2, wherein a heat exchanger for exchanging heat between a refrigerant and heat generated from an energy source of an automobile equipped with the refrigeration cycle is built in the accumulator. Refrigeration cycle with pipeline. 4. A heat exchanger for exchanging heat between a refrigerant and heat generated from an energy source of an automobile equipped with the refrigerating cycle is provided adjacent to the accumulator in a refrigerant pipe line on an upstream side thereof. The refrigeration cycle with a bypass pipe line according to claim 1 or 2, which is plugged and connected.