JPS6071861A - Refrigeration cycle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a refrigeration cycle that is particularly provided with a refrigerant control valve, a gas-liquid separator, and a gas bypass circuit, and particularly relates to a refrigeration cycle that reduces power consumption of the refrigeration cycle. It is suitable for It is also suitable for reducing the cost of the compressor starting device.

[Background of the invention]

Conventionally, in this type of refrigerator, the temperature inside the refrigerator is controlled by intermittent operation of a compressor forming a cooling system using a temperature detection thermostat provided inside the refrigerator. Particularly when using a rotary compressor, the weight of refrigerant in the compressor and condenser is large, so when the compressor is stopped, hot gas flows from the compressor and condenser into the evaporator, resulting in a drop in evaporator temperature. This increases the heat load inside the refrigerator and increases power consumption.

Therefore, as a preventive measure, between the high pressure side and the low pressure side.

A refrigerant control valve is installed to prevent hot gas on the high pressure side from flowing into the evaporator when the compressor is stopped, and to prevent hot gas from flowing back into the evaporator from the high pressure side via the compressor. It is shut off by a check valve installed between the machines. In such a refrigeration cycle, if there is little hot gas leaking from the high-pressure side to the low-pressure side via the compressor when the compressor is stopped, the pressure balance between the compressor suction side and the discharge side is poor, and the load on the compressor when the compressor is started will increase. becomes larger, and a compressor with larger starting torque is required. In this way, in conventional refrigeration cycles, even if hot gas is prevented from flowing from the high-pressure side to the low-pressure side when the compressor is stopped, as the coefficient of performance of rotary compressors improves, hot gas flows from the high-pressure side inside the compressor to the low-pressure side. If the leakage of hot gas to the compressor is reduced, the starting torque of the compressor must be increased.

In addition, solenoid valves are generally used as refrigerant control valves installed to prevent the inflow of hot gas, but they have problems such as requiring electrical input or making impact noises when opening and closing, resulting in low power consumption. There were disadvantages such as an increase in noise and the installation of soundproofing equipment.

[Purpose of the invention]

The present invention focuses on this type of problem, improves the above-mentioned drawbacks, and improves the efficiency of the refrigeration cycle during operation, thereby reducing power consumption, downsizing the compressor, and simplifying the starting device. Our objective is to provide a refrigeration cycle that achieves cost reduction.

[Summary of the invention]

In the present invention, even if the condensed gas refrigerant flows into the evaporator during compressor operation, no refrigeration effect can be obtained, so the gas refrigerant is bypassed to the compressor suction side by the gas-liquid separator, so when the compressor is stopped, The pressures on the compressor suction side and discharge side are balanced.

Furthermore, when the compressor is stopped, the refrigerant control valve prevents hot gas from flowing into the evaporator from the compressor and condenser, thereby reducing power consumption.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 2 and 4. 1 is a compressor, 2 is a condenser, and 4 is a pressure reducer.

5 is an evaporator, and 6 is a check valve, which are connected in sequence to form a refrigeration cycle. 7 is a gas-liquid separator.

3 is a refrigerant control valve, and 10 is a communication pipe for opening and closing the refrigerant control valve, which is led from between the compressor suction port and the check valve. 8 is connected to the upper end of the gas-liquid separator, and the other end is a bypass circuit connected between the suction port of the compressor and the check valve, and a capillary tube 9 is connected in the middle. The refrigerant control valve 3 is connected between the pressure reducer and the gas-liquid separator between the condenser and the pressure reducer.

Next, the operation of this refrigeration cycle will be explained with reference to FIG.

The refrigerant control valve 3 is open during compressor operation. The gas refrigerant and liquid refrigerant are separated by the gas-liquid separator, and the gas refrigerant passes through the gas bypass circuit 8 and flows into the compressor suction port. The refrigeration cycle in this case is as shown by the broken line in Figure 4, and the gas refrigerant being condensed does not need to be cooled down to the temperature of the evaporator 5, but only by the difference in gas enthalpy that is lowered to the temperature of the evaporator 5 than in the conventional cycle. This has the advantage of increasing the enthalpy of the liquid refrigerant flowing within the evaporator. Additionally, when the compressor is stopped, high-pressure gas from the condenser passes through the bypass circuit and flows between the compressor suction port and the check valve, so the pressure between the compressor suction port and the check valve increases rapidly. .

The refrigerant control valve is closed to apply pressure through the communication tube 10 to the diaphragm or bellows within the refrigerant control valve.

Therefore, while the compressor is stopped, hot gas in the compressor and condenser can be prevented from flowing into the evaporator.Furthermore, since the pressure on the compressor suction side increases, the pressure on the compressor discharge side is reduced. is balanced.

Further, by providing the capillary tube 9 in the gas bypass circuit 8, it is possible to reduce the refrigerant noise generated when the pressures on the suction side and the discharge side of the compressor are balanced after the compressor is stopped.

As described above, according to the present invention, a refrigerant control valve and a gas-liquid separator are combined and used in a refrigeration cycle, thereby discharging hot water from the compressor and condenser to the evaporator while the compressor is stopped during compressor operation. By preventing gas inflow and reducing power consumption, and by creating a perfect pressure balance between the suction side and the discharge side of the compressor 1, the starting torque of the compressor can be reduced. It is possible to reduce the size of the device and reduce the cost of the starting device.

Although the refrigerant control valve of the present invention has been described as a differential pressure valve that operates using differential pressure, the present invention is not limited to this.

Similar effects can be achieved with solenoid valves and instantaneous energization valves.

〔Effect of the invention〕

According to the present invention, in a refrigeration cycle that performs intermittent operation, the pressure between the compressor suction port and the check valve increases through the gas bypass circuit while the compressor is stopped, so that the refrigerant control valve closes and the compressor It is possible to prevent hot gas from flowing into the evaporator from the refrigerator and the condenser, and to cut off the heat load entering the refrigerator, reducing power consumption by 15 to 20%.

Furthermore, hot gas flows from the gas bypass circuit between the compressor suction port and the check valve, and the pressures on the compressor suction side and discharge side are balanced, reducing the compressor starting torque or reducing the compressor speed. It is possible to downsize or reduce the cost of the starting device.

Furthermore, during compressor operation, the gas refrigerant separated by the gas-liquid separator flows into the compressor suction side through the gas bypass circuit, so it is on the saturated liquidus line at the inlet of the pressure reducer, and the gas refrigerant is depressurized from that point. There is no need to cool the refrigerant to the evaporator temperature, and the amount of heat is used for cooling, so power is saved and power consumption can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional refrigeration cycle. FIG. 2 is a block diagram of a refrigeration cycle according to the present invention. FIG. 3 is a Mollier diagram showing a conventional refrigeration cycle. FIG. 4 is a Mollier diagram for explaining the refrigeration cycle of the present invention. DESCRIPTION OF SYMBOLS 1... Compressor, 2... Condenser, 3... Refrigerant control valve, 4... Pressure reducer, 5... Evaporator, 6... Check valve,
7... Gas-liquid separator, 8... Gas bypass circuit, 9...
...Capillary tube, 10...Communication tube. Agent Patent Attorney Akio Takahashi: lf, s＠ ′＄4 Enthalpy 0

Claims (1)

[Claims] In a refrigeration cycle formed by sequentially connecting a compressor, a condenser, a pressure reducer, an evaporator, and a check valve, a gas-liquid separator is provided between the condenser and the pressure reducer. A refrigeration cycle characterized in that a refrigerant control valve is provided in the middle of the pressure reducer, and a gas bypass circuit is provided from the gas-liquid separator to between the compressor suction port and the check valve. 2. The refrigeration cycle according to claim 1, wherein the compressor is a rotary compressor. 3. The refrigeration cycle according to claim 1, characterized in that a capillary tube is provided in the gas bypass circuit according to claim 1.