JPH0821664A - Refrigerating cycle device - Google Patents

Abstract

PURPOSE:To improve a coefficient of performance of a refrigerating cycle, reduce the discharging gas temperature of a compressor, and effectively utilize cold heat upon defrosting operation with a simple constitution. CONSTITUTION:Upon normal operation, refrigerant from a compressor 1 is guided to a condenser 3 through a four-way valve 2, gas refrigerant, separated by a gas/liquid separator 6 and whose pressure is reduced in a first choking device 5, is guided to the injection port of the compressor 1 through a second evaporator 9 while liquid refrigerant is guided to the suction port of the compressor 1 through a second choking device 7, the first evaporator 8 and the four-way valve 2. Upon defrosting operation, the refrigerant from the compressor 1 is guided to the first evaporator 8 by switching the four-way valve 2 and the refrigerant, liquefied in the first evaporator 8, is guided to the injection port 11 of the compressor 1 through the gas/liquid separator 6, the second evaporator 9 and the second choking device 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a refrigerating cycle device which improves the efficiency of a refrigerating cycle used in a refrigerator and a refrigerator.

[0002]

2. Description of the Related Art A conventional refrigeration cycle apparatus, for example, a refrigerator-freezer, has a compressor for compressing a refrigerant, a condenser for cooling a high-temperature and high-pressure gas refrigerant discharged from the compressor into a liquid refrigerant, and a decompressing liquid refrigerant. A refrigeration cycle is configured by sequentially connecting the expansion device and the evaporator that evaporates the liquid refrigerant and removes heat in the refrigerator.

In such a freezer-refrigerator, the liquid refrigerant liquefied in the condenser is decompressed by the expansion device, the refrigerant is flown into the evaporator, and the freezing chamber is cooled by exchanging heat with the air in the refrigerator by a cooling fan or the like. A portion of the cold air in the freezer compartment is guided to the medium temperature refrigerator compartment through the air passage in the refrigerator, and the temperature of the refrigerator compartment is maintained at a temperature higher than the freezer compartment temperature by adjusting the amount of that cool air with a damper or the like. ing.

Further, in the defrosting operation which is regularly performed to remove frost from the evaporator, the frost removing heater provided in the vicinity of the evaporator is energized to heat the evaporator through the air so that the outside of the evaporator is cooled. Was melting the frost.

[0005]

However, in such a conventional freezer-refrigerator, one evaporator is intended to cool the freezing compartment and the refrigerating compartment at different temperatures, so that the evaporator has a low temperature. Therefore, the suction pressure of the compressor is lowered, the compression ratio of the compressor is increased, and the discharge temperature is increased and the coefficient of performance is decreased.

Further, since the pressure at the inlet of the evaporator is low, the refrigerant at the inlet of the evaporator is in a state of containing a large amount of gas refrigerant, and the coefficient of performance is further lowered due to the increase of the pressure loss in the evaporator.

Further, in the defrosting operation, the electric heater provided near the evaporator was heated, so that the power consumption in that case was high.

The present invention has been made in view of the above points, and solves the technical problem of the conventional refrigeration cycle apparatus, and improves the coefficient of performance during operation with a relatively simple structure. It is also an object of the present invention to provide a refrigeration cycle device that can reduce not only the discharge gas temperature of the compressor but also the power consumption during the defrosting operation.

[0009]

SUMMARY OF THE INVENTION The present invention is directed to a compressor for compressing a refrigerant, a condenser for cooling the refrigerant discharged from the compressor, a throttle device for decompressing the refrigerant from the condenser, and a decompressor. A refrigeration cycle apparatus including an evaporator that evaporates the refrigerant and discharges the refrigerant to the suction port of the compressor, and a sub-throttle device that further depressurizes the refrigerant that has been decompressed by the expansion device and supplies the refrigerant to the evaporator. On the other hand, a sub-evaporator into which the refrigerant branched between the expansion device and the sub expansion device is introduced is provided, and the refrigerant evaporated in the sub-evaporator is separated from the compressor different from the suction port. It is designed to be introduced into the injection port, which is the suction port of the.

Further, according to the present invention, heat is exchanged between the pipes extending from the respective evaporators to the respective suction ports of the compressor.

Further, according to the present invention, the refrigerant discharged from the compressor is guided to the evaporator, and the refrigerant discharged from the evaporator is passed through the sub-throttle device and the sub-evaporator to the compressor. It is provided with a switching means for performing a defrosting operation by switching to a pipe introduced to another suction port.

[0012]

In the refrigeration cycle apparatus of the present invention, the sub-throttle device for further depressurizing the refrigerant depressurized by the throttling device and leading it to the evaporator is provided, while branching between the sub-throttle device and the sub-throttle device. With the provision of a sub-evaporator into which the compressed refrigerant is introduced, the refrigerant evaporated in this sub-evaporator is introduced into an injection port, which is another suction port of the compressor different from the suction port, Then, low-temperature cold heat is generated, and on the other hand, the branched refrigerant has a small latent heat of itself, so that the sub-evaporator generates medium-temperature cold heat. The refrigerant discharged from the sub-evaporator is sucked into the injection port of the compressor to reduce the required power of the compressor and contribute to the cooling of the compressor, so that the reliability of the compressor can be enhanced. Furthermore, by introducing the branched gas refrigerant into the sub-evaporator, the gas refrigerant flowing into the evaporator can be reduced, so that the pressure loss in the evaporator is reduced and the coefficient of performance can be improved.

Further, in the refrigeration cycle apparatus of the present invention, since the pipes from each of the evaporators to each of the suction ports of the compressor are heat-exchanged, the refrigerant from the evaporator which generates low temperature cold heat is Since the temperature rises due to the replacement, no condensation occurs in the pipe leading to the compressor.

Furthermore, in the refrigeration cycle apparatus of the present invention,
The high temperature and high pressure refrigerant discharged from the compressor is guided to the evaporator, and the refrigerant from the evaporator is introduced into the another suction port of the compressor via the sub expansion device and the sub evaporator. Since there is a switching means for switching to the pipe and performing the defrosting operation, the defrosting time is shortened by heating the evaporator from the inside of the pipe, and moreover, the refrigerant liquefied from the evaporator is guided to the sub-evaporator. As a result, cold heat is generated, so that the amount of heat generated during defrosting can be effectively used.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a schematic circuit diagram of a refrigerating cycle apparatus according to an embodiment of the present invention. In this embodiment, a refrigerating refrigerator will be described.

In the figure, 1 is a compressor, 2 is a four-way valve constituting a switching means, 3 is a condenser, 4 is a check valve, and 5 is a first valve.
A throttle device, 6 is a gas-liquid separator, 7 is a second throttle device as a sub-throttle device, and 8 is a first evaporator, which is connected in sequence to pipes and constitutes a refrigeration cycle for returning to the four-way valve 2 again. The upper part of the gas-liquid separator 6 is connected to the second evaporator 9 as a sub-evaporator, and a heat exchanger 10 is provided at the outlet thereof so that heat is exchanged with the outlet pipe of the first evaporator 8. Further, it is connected to a gas injection port 10 as another suction port of the compressor 1.

In such a refrigeration cycle apparatus, when the compressor 1 is in operation, by connecting the four-way valve to the circuit of the solid line, as shown by the solid line arrow A, the refrigerant compressed to high temperature and high pressure in the compressor 1 is discharged. It passes through the four-way valve 2, is liquefied in the condenser 3, is further throttled to an intermediate pressure by the check valve 4 and the first expansion device 5, and flows into the gas-liquid separator 6. Here, the refrigerant is separated into liquid and gas, and the liquid refrigerant therein is throttled to a low pressure by the second expansion device 7 and flows into the first evaporator 8. Here, cold heat is generated to cool a freezer compartment (not shown) which is a colder compartment.

On the other hand, the gas component separated by the gas-liquid separator 6 flows into the second evaporator 9, but here, since the latent heat of the refrigerant is small, a refrigerating chamber (not shown in the figure) which is a medium temperature chamber is provided. ) Cool.

In the conventional example, one evaporator is used to cool the freezing compartment and the refrigerating compartment, so that the temperature of the evaporator into which all the refrigerants are introduced needs to be lower than the freezing compartment temperature. Then, since the refrigerant is branched and a part of the refrigerant is guided to the second evaporator, the remaining refrigerant is guided to the first evaporator.
Only in the evaporator, it is necessary to keep the temperature below the freezing compartment, which can reduce the required power of the compressor.

Further, in this embodiment, the refrigerant discharged from the first evaporator 8 exchanges heat with the refrigerant discharged from the second evaporator in the heat exchanger 10, so that the refrigerant discharged from the first evaporator 8 is removed. Since the temperature rises, dew condensation due to heat exchange with air on the pipe leading to the four-way valve 2 does not occur. On the contrary, since the temperature of the refrigerant exiting the second evaporator 9 is lowered by the heat exchanger 10, the temperature of the refrigerant flowing into the gas injection port 11 of the compressor 1 is lowered, and the compressor 1 can be cooled more. Not only is it possible, but the gas generated in the gas-liquid separator 6 is not allowed to flow into the low-pressure first evaporator 8. Therefore, the pressure loss here is reduced and the coefficient of performance of the refrigeration cycle is improved. In addition, as another embodiment of the present invention, the heat exchanger 10 may be omitted.

In addition, in this embodiment, an operating time integrator 12 for integrating the operating time of the compressor 1 is provided, and when the operating time integrator 12 exceeds a predetermined time, the four-way valve 2 as a switching means is operated. By switching to the circuit of the broken line, the refrigerant compressed to high temperature and high pressure in the compressor 1 as shown by the broken line arrow B passes through the four-way valve 2 and radiates heat in the first evaporator 8 to release the first evaporation. Defrosting operation is performed to melt the frost on the vessel.

In this case, since the heating is performed directly from the inside of the tube of the first evaporator, the defrosting time can be drastically shortened as compared with the conventional method of indirectly heating with a heater. .

Further, the refrigerant radiated by the first evaporator 8 and liquefied is decompressed by the second expansion device 7, becomes a low temperature and flows into the second evaporator 9 through the gas-liquid separator 6, so that Thus, cold heat can be generated to contribute to the cooling of the interior (not shown) of the second evaporator 9. Further, the gasified refrigerant is sucked from the gas injection port 11 of the compressor 1 via the heat exchanger 10 and circulated,
The defrosting time can be shortened and the cold heat at the time of defrosting can be effectively used.

As another embodiment of the present invention, it goes without saying that the operation may be switched to the defrosting operation as required by a changeover switch or the like.

[0026]

As described above, in the refrigeration cycle apparatus of the present invention, low-temperature cold heat is generated in the evaporator depressurized by the expansion device and the sub expansion device, while the branched refrigerant is heated to a medium temperature in the sub evaporator. The cold heat of the compressor is generated and sucked into the injection port, which is another suction port of the compressor, which reduces the required power of the compressor and contributes to the cooling of the compressor, thus improving the reliability of the compressor. it can. Further, by branching the gas refrigerant and guiding it to the sub-evaporator, the gas refrigerant flowing into the evaporator can be reduced, so that the pressure loss in the evaporator is reduced and the coefficient of performance can be improved.

Further, in the refrigeration cycle apparatus of the present invention, the pipes from the respective evaporators to the respective suction ports of the compressor are heat-exchanged, so that the refrigerant from the evaporator which generates low temperature cold heat is As the temperature rises due to replacement,
Condensation does not occur in the piping leading to the compressor.

Further, during the defrosting operation, the connection of the pipes is switched by the switching means so that the high-temperature and high-pressure refrigerant is flown into the evaporator to heat it from the inside of the pipe to accelerate the defrosting time and to liquefy from the evaporator. Since the refrigerant is guided to the sub-evaporator to generate cold heat, the heat quantity generated at the time of defrosting can be effectively used, which is a great effect.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a refrigeration cycle apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 1 Compressor 2 4-way valve 3 Condenser 4 Check valve 5 1st expansion device 6 Gas-liquid separator 7 2nd expansion device 8 1st evaporator 9 2nd evaporator 10 Heat exchanger 11 Gas injection port 12 Operating time integration Total

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technology display location F25B 47/02 J (72) Inventor Yuji Yoshida 1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric Industrial Co., Ltd. Within

Claims (4)

[Claims] 1. A compressor for compressing a refrigerant, a condenser for cooling the refrigerant drawn from the compressor, a throttle device for depressurizing the refrigerant from the condenser, and a compressor for evaporating the depressurized refrigerant. In a refrigeration cycle apparatus including an evaporator that is led to a suction port of a machine, a refrigerant that is decompressed by the expansion device is further decompressed, and a sub expansion device that supplies the refrigerant to the evaporator is provided, while the expansion device and the sub device A sub-evaporator into which a refrigerant branched between the expansion device is introduced is provided, and the refrigerant evaporated in the sub-evaporator is introduced into another suction port of the compressor different from the suction port. A characteristic refrigeration cycle device. 2. The refrigeration cycle apparatus according to claim 1, wherein the pipes from the respective evaporators to the respective suction ports of the compressor are heat-exchanged. 3. A suction port of the compressor, which introduces the refrigerant discharged from the compressor to the evaporator and allows the refrigerant from the evaporator to pass through the sub expansion device and the sub evaporator. The refrigeration cycle apparatus according to claim 1, further comprising switching means for switching to a pipe to be introduced into the pipe and performing a defrosting operation. 4. The refrigeration cycle apparatus according to claim 3, wherein the switching means switches to the defrosting operation when the operating time accumulator for accumulating the operating time exceeds a predetermined time.