Refrigeration cycle device and air conditioner

Abstract

The present invention addresses the problem of providing a refrigeration cycle device that can suppress a disproportionation reaction even if a circulation composition ratio of a refrigerant changes during operation. A refrigeration cycle device 1 comprises a refrigerant circuit in which a compressor 4, an outdoor heat exchanger 10, an indoor heat exchanger 11, an expansion valve 20, and a receiver 30 are connected through piping, and in which a mixed refrigerant that includes an ethylene-based HFO refrigerant circulates. The receiver 30 adjusts the refrigerant amount of the mixed refrigerant circulating in the refrigerant circuit, and the volume of the receiver is set such that the circulation composition ratio of the ethylene-based HFO refrigerant when the mixed refrigerant circulates in the refrigerant circuit is equal to or less than a composition ratio at which a disproportionation reaction occurs.

Claims

1. A refrigeration cycle apparatus comprising a compressor, a condenser, an evaporator, a throttling device, and a receiver connected by piping, comprising a refrigerant circuit through which a mixed refrigerant containing an ethylene-based HFO refrigerant circulates, wherein the receiver stores a portion of the mixed refrigerant circulating in the refrigerant circuit, and the capacity of the receiver is set such that the circulating composition ratio of the ethylene-based HFO refrigerant when the mixed refrigerant circulates in the refrigerant circuit is less than or equal to the composition ratio at which a disproportionation reaction occurs.

2. The refrigeration cycle apparatus according to claim 1, further comprising a protective device that protects the compressor when the temperature and pressure inside the compressor exceed a protective threshold, wherein the protective threshold is the temperature and pressure inside the compressor at the maximum value of the circulating composition ratio of the ethylene-based HFO refrigerant in the mixed refrigerant sealed in the refrigerant circuit when the maximum amount of the mixed refrigerant is stored in the receiver.

3. A refrigeration cycle apparatus comprising: a compressor, a condenser, an evaporator, a throttling device, and a receiver connected by piping, a refrigerant circuit through which a mixed refrigerant containing an ethylene-based HFO refrigerant circulates; and a protective device that protects the compressor when the temperature and pressure inside the compressor exceed a protective threshold, wherein the protective threshold is the temperature and pressure inside the compressor at the maximum value of the circulating composition ratio of the ethylene-based HFO refrigerant in the mixed refrigerant sealed in the refrigerant circuit when the receiver is filled with the maximum amount of the mixed refrigerant.

4. The refrigeration cycle apparatus according to any one of claims 1 to 3, wherein the capacity of the receiver is set to be less than or equal to the value obtained by the formula: first amount × third amount / fourth amount, where the amount of refrigerant in the mixed refrigerant sealed in the refrigerant circuit is the first amount, the maximum value of the circulating composition ratio of the ethylene-based HFO refrigerant in the mixed refrigerant is the second amount, the amount of liquid refrigerant stored in the receiver is divided by the first amount and the remaining refrigerant amount ratio is the third amount, and the saturated liquid density of the mixed refrigerant is the fourth amount.

5. The refrigeration cycle apparatus according to claim 4, characterized in that the first amount is the initial filling amount of the mixed refrigerant at the time of factory shipment.

6. The refrigeration cycle apparatus according to claim 4 or 5, characterized in that the ratio of retained refrigerant volume and the saturated liquid density are values ​​at the refrigerant temperature in the receiver, and the refrigerant temperature is the lowest temperature used in the refrigeration cycle.

7. The refrigeration cycle apparatus according to claim 6, characterized in that the minimum temperature is -40°C.

8. The refrigeration cycle apparatus according to any one of claims 1 to 7, characterized in that the receiver is disposed between the evaporator and the compressor.

9. The refrigeration cycle apparatus according to claim 2 or 3, further comprising a control unit that changes the protection threshold from an initial value based on the operating state of the refrigerant circuit.

10. The refrigeration cycle apparatus according to claim 9, further comprising a detection unit for detecting the amount of refrigerant in the receiver, wherein the control unit changes the protection threshold to the high temperature / high pressure side as the amount of refrigerant in the receiver detected by the detection unit decreases, and changes the protection threshold to the low temperature / low pressure side as the amount of refrigerant in the receiver detected by the detection unit increases.

11. The refrigeration cycle apparatus according to claim 10, characterized in that the detection unit is a liquid level sensor installed in the receiver.

12. The refrigeration cycle apparatus according to any one of claims 9 to 11, characterized in that the control unit reduces the amount of change in the protection threshold as the refrigerant temperature of the mixed refrigerant in the receiver increases.

13. The refrigeration cycle apparatus according to any one of claims 9 to 12, characterized in that the control unit changes the protection threshold when the operating frequency of the compressor is above a predetermined frequency.

14. The refrigeration cycle apparatus according to any one of claims 9 to 13, characterized in that the refrigerant circuit is connected to a plurality of indoor units, and the control unit changes the protection threshold to the high temperature / high pressure side as the number of indoor units in operation decreases, and changes the protection threshold to the low temperature / low pressure side as the number of indoor units in operation increases.

15. The refrigeration cycle apparatus according to any one of claims 9 to 14, characterized in that the protective device stops the operation of the compressor when the temperature and pressure inside the compressor exceed the protective threshold, and the compressor remains stopped until the operation restart procedure is performed.

16. An air conditioner using a refrigeration cycle device according to any one of claims 1 to 15.

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