Refrigeration/air conditioning equipment

Abstract

Refrigeration/air conditioning equipment includes a first internal heat exchanger for exchanging heat between a refrigerant to be sucked in a compressor and a high-pressure liquid refrigerant, an injection circuit for evaporating a bypassed high-pressure liquid at intermediate pressure and injecting the vaporized refrigerant into the compressor, a second internal heat exchanger for exchanging heat between the high-pressure liquid refrigerant and the refrigerant to be injected, and a heat source for heating the refrigerant to be injected.

1. Refrigeration/air conditioning equipment comprising:
 a compressor; 
 a four-way valve; 
 an indoor heat exchanger; 
 a first decompressor; and 
 an outdoor heat exchanger, 
 wherein these components are coupled circularly, and heat is supplied from the indoor heat exchanger, 
 the refrigeration/air conditioning equipment further comprising: 
 an intermediate-pressure receiver disposed between the indoor heat exchanger and the first decompressor; 
 a first internal heat exchanger that exchanges heat between a refrigerant in the intermediate-pressure receiver and a refrigerant in a suction pipe of the compressor; and 
 an injection circuit in which part of a refrigerant between the indoor heat exchanger and the first decompressor is bypassed and is injected into a compression chamber in the compressor, 
 the injection circuit comprising:
 a second decompressor; 
 a second internal heat exchanger that exchanges heat between a refrigerant having a pressure reduced by the second decompressor and the refrigerant between the indoor heat exchanger and the first decompressor; and 
 a heat source for heating a refrigerant, disposed between the second internal heat exchanger and the compressor. 
 
 
     
     
       2. The refrigeration/air conditioning equipment according to  claim 1 , wherein a third decompressor is provided between the indoor heat exchanger and the intermediate-pressure receiver. 
     
     
       3. The refrigeration/air conditioning equipment according to  claim 1 , further comprising a controller for controlling the degree of superheat of a refrigerant sucked into the compressor or the degree of superheat of a refrigerant at the outlet of the outdoor hear exchanger to a predetermined value by adjusting the first decompressor. 
     
     
       4. The refrigeration/air conditioning equipment according to  claim 1 , further comprising a controller for controlling the discharge temperature or the degree of superheat of a refrigerant at the outlet of the compressor to a predetermined value by adjusting the second decompressor. 
     
     
       5. The refrigeration/air conditioning equipment according to  claim 2 , further comprising a controller for controlling the degree of supercooling of a refrigerant at the outlet of the indoor heat exchanger to a predetermined value by adjusting the third decompressor. 
     
     
       6. The refrigeration/air conditioning equipment according to  claim 2 , further comprising a controller for controlling the degree of superheat of a refrigerant sucked into the compressor or the degree of superheat of a refrigerant at the outlet of the outdoor hear exchanger to a predetermined value by adjusting the first decompressor. 
     
     
       7. The refrigeration/air conditioning equipment according to  claim 2 , further comprising a controller for controlling the discharge temperature or the degree of superheat of a refrigerant at the outlet of the compressor to a predetermined value by adjusting the second decompressor. 
     
     
       8. Heating equipment, comprising:
 a first heat exchanger that makes a refrigerant absorb heat of air;   a compressor that sucks the refrigerant from the first heat exchanger;   a second heat exchanger that provides a load side medium with heat of the refrigerant discharged from the compressor;   a first expansion valve that decompresses the refrigerant flowing from the second heat exchanger to the first heat exchanger, the first heat exchanger, compressor, second heat exchanger and first expansion valve being connected so as to circulate the refrigerant;   a third heat exchanger that exchanges heat between the refrigerant flowing from an outlet of the second heat exchanger to an inlet of the first heat exchanger and the refrigerant flowing from the first heat exchanger toward a suction inlet of the compressor;   an injection circuit that merges part of the refrigerant flowing from the second heat exchanger to the first heat exchanger with the refrigerant that is sucked by the compressor via the first heat exchanger to be compressed to an intermediate pressure;   a second expansion valve that is installed in the injection circuit and decompresses the refrigerant flowing in the injection circuit;   a fourth heat exchanger that is installed in the injection circuit to supply heat of the refrigerant flowing from the second heat exchanger toward the first heat exchanger to the refrigerant flowing toward an injection inlet of the compressor in the injection circuit; and   a controller that controls an opening degree of the first and the second expansion valves.   
     
     
       9. The heating equipment of claim 8, wherein
 the controller controls the second expansion valve so that the refrigerant flowing in the injection circuit becomes a gas-liquid two phase state.   
     
     
       10. The heating equipment of claim 8, wherein
 the injection circuit branches from between the second heat exchanger and the first expansion valve.   
     
     
       11. The heating equipment of claim 10, wherein
 the injection circuit branches from between the third heat exchanger and the fourth heat exchanger.   
     
     
       12. The heating equipment of claim 8 comprising:
 a third expansion valve provided between the second heat exchanger and the third heat exchanger to be controlled by the controller.   
     
     
       13. The heating equipment of claim 12, wherein
 the third heat exchanger has a receiver provided with a function to store part of the refrigerant flowing from the second heat exchanger to the first heat exchanger, and exchanges heat between the refrigerant stored within the receiver and the refrigerant flowing from the first heat exchanger to the compressor.   
     
     
       14. The heating equipment of claim 13, wherein
 the third expansion valve decompresses the refrigerant flowing from the second heat exchanger to the receiver.   
     
     
       15. The heating equipment of claim 8, wherein
 the second heat exchanger is a condenser.   
     
     
       16. The heating equipment of claim 8, wherein
 the load side medium that exchanges heat with the refrigerant discharged from the compressor in the second heat exchanger is air.   
     
     
       17. The heating equipment of claim 8, wherein
 the load side medium that exchanges heat with the refrigerant discharged from the compressor in the second heat exchanger is water.   
     
     
       18. The heating equipment of claim 8 comprising a
 temperature sensor that detects a discharge temperature of the refrigerant discharged from the compressor, wherein   the controller controls an opening degree of the second expansion valve to be large so as to decrease enthalpy of the refrigerant when the discharge temperature detected by the temperature sensor is higher than a target value, and controls the opening degree of the second expansion valve to be small so as to increase enthalpy of the refrigerant when the discharge temperature is lower than the target value.   
     
     
       19. An outdoor unit of heating equipment including a first heat exchanger that makes a refrigerant absorb heat of air, a compressor that sucks the refrigerant from the first heat exchanger and discharges the refrigerant to a second heat exchanger that is externally installed, and a first expansion valve that decompresses the refrigerant flowing toward the first heat exchanger after providing a load side medium with heat in the second heat exchanger, comprising
 a third heat exchanger that exchanges heat between the refrigerant flowing from an outlet of the second heat exchanger toward an inlet of the first heat exchanger and the refrigerant flowing from the first heat exchanger toward a suction inlet the compressor;   an injection circuit that merges part of the refrigerant flowing from the second heat exchanger toward the first heat exchanger with the refrigerant that is sucked by the compressor via the first heat exchanger to be compressed to an intermediate pressure;   a second expansion valve that is installed in the injection circuit and decompresses the refrigerant flowing in the injection circuit;   a fourth heat exchanger that is installed in the injection circuit to supply heat of the refrigerant flowing from the second heat exchanger toward the first heat exchanger to the refrigerant flowing toward an injection inlet of the compressor in the injection circuit; and   a controller that controls an opening degree of the first and the second expansion valves.   
     
     
       20. The outdoor unit of heating equipment of claim 19, wherein
 the controller controls the second expansion valve so that the refrigerant flowing in the injection circuit becomes a gas-liquid two phase state.   
     
     
       21. The outdoor unit of heating equipment of claim 19, wherein
 the injection circuit branches from between the second heat exchanger and the first expansion valve.   
     
     
       22. The outdoor unit of heating equipment of claim 21, wherein
 the injection circuit branches from between the third heat exchanger and the fourth heat exchanger.   
     
     
       23. The outdoor unit of heating equipment of claim 19 comprising:
 a third expansion valve provided between the second heat exchanger and the third heat exchanger to be controlled by the controller.   
     
     
       24. The outdoor unit of heating equipment of claim 23, wherein
 the third heat exchanger has a receiver having a function to store part of a refrigerant flowing from the second heat exchanger to the first heat exchanger, and exchanges heat between the refrigerant stored in the receiver and the refrigerant flowing from the first heat exchanger to the compressor.   
     
     
       25. The outdoor unit of heating equipment of claim 24, wherein
 the third expansion valve decompresses the refrigerant flowing from the second heat exchanger to the receiver.   
     
     
       26. The outdoor unit of heating equipment of claim 19, wherein
 the second heat exchanger is a condenser.   
     
     
       27. The outdoor unit of heating equipment of claim 19, wherein
 the load side medium that exchanges heat with the refrigerant discharged from the compressor in the second heat exchanger is air.   
     
     
       28. The outdoor unit of heating equipment of claim 19, wherein
 the load side medium that exchanges heat with the refrigerant discharged from the compressor in the second heat exchanger is water.   
     
     
       29. The outdoor unit of heating equipment of claim 19 including a temperature sensor that detects a discharge temperature of the refrigerant discharged from the compressor, wherein
 the controller controls an opening degree of the second expansion valve to be large so as to decrease enthalpy of the refrigerant when the discharge temperature detected by the temperature sensor is higher than a target value and controls the opening degree of the second expansion valve to be small so as to increase enthalpy of the refrigerant when the discharge temperature is lower than the target value.