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. A controller of heating equipment including a primary refrigerant circuit 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, wherein the first heat exchanger, the compressor, the second heat exchanger and the first expansion valve are connected so as to circulate the refrigerant;   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 third heat exchanger that is installed in the primary refrigerant circuit and the injection circuit and supplies heat of the refrigerant flowing from the second heat exchanger toward the first heat exchanger to the refrigerant flowing in the injection circuit;   a second expansion valve that is installed in the injection circuit and decompresses the refrigerant flowing in the injection circuit;   a first temperature sensor that detects a discharge temperature of the refrigerant discharged from the compressor; and   a controller that controls an opening degree of the second expansion valve so that the discharge temperature detected by the first temperature sensor, which is correlated with the refrigerant flow amount flowing in the injection circuit, coincides with a predetermined target value in order to adjust heating ability of the second heat exchanger by a refrigerant flow amount flowing in the injection circuit.   
     
     
       9. The controller of the heating equipment of claim 8, wherein
 the controller controls such that the opening degree of the second expansion valve is increased so as to decrease an enthalpy of the refrigerant flowing in the injection circuit when the discharge temperature detected by the first temperature sensor is higher than the target value and the opening degree of the second expansion valve is decreased so as to increase the enthalpy of the refrigerant flowing in the injection circuit when the discharge temperature is lower than the target value.   
     
     
       10. The controller of the heating equipment of claim 8, comprising;
 a second temperature sensor for detecting a temperature of the refrigerant in the first heat exchanger, and a fourth temperature sensor for detecting a temperature of the refrigerant flowing into the compressor, wherein   the controller calculates a degree of superheat of the refrigerant at a suction side of the compressor based on the temperature detected by the second temperature sensor and the temperature detected by the fourth temperature sensor, and controls the first expansion valve such that a predetermined target value of the degree of superheat of the refrigerant is calculated.   
     
     
       11. The controller of the heating equipment of claim 8, wherein the injection circuit branches from between the second heat exchanger and the first expansion valve. 
     
     
       12. The controller of the heating equipment of claim 8, wherein the refrigerant is a CO2 refrigerant. 
     
     
       13. The controller of the heating equipment of claim 8, wherein the refrigerant is a HC type refrigerant. 
     
     
       14. The controller of the heating equipment of claim 8, wherein
 the load side medium that exchanges heat with the refrigerant discharged from the compressor in the heat exchanger on the load side is air.   
     
     
       15. The controller of the heating equipment of claim 8, wherein
 the load side medium that exchanges heat with the refrigerant discharged from the compressor in the heat exchanger on the load side is water.