Air-conditioning apparatus

Abstract

Providing an air-conditioning apparatus that is capable of securing safety while reducing load to the environment. The air-conditioning apparatus 100 includes a concentration detection device 305 that detects the concentration of a heat source side refrigerant leaking from the refrigerant circuit, shut off devices (first shut off device 303 and second shut off device 304 ) that shut off the circulation of the heat source side refrigerant on the basis of information from the concentration detection device 305.

1 . An air-conditioning apparatus, comprising:
 an outdoor unit including at least a compressor and a heat source side heat exchanger;   an indoor unit including at least an expansion device and a use side heat exchanger;   a refrigerant circuit being formed by refrigerant piping connecting the compressor, the heat source side heat exchanger, the expansion device, and the use side heat exchanger, the refrigerant circuit in which a heat source side refrigerant that transmits to in a supercritical state circulates;   a concentration detection device detecting a concentration of the refrigerant that has leaked from the refrigerant circuit, the concentration detection device being provided in the indoor unit or in the installation space of the indoor unit;   a shut off device that shuts off the circulation of the heat source side refrigerant on the basis of information from the concentration detection device, the shut off device being provided on both sides of refrigerant outlet and inlet in the indoor unit; and   the shut off device makes an electrical component thereof driven by DC power supply, is in an opened state when energized, and is in a closed state when not energized.   
     
     
         2 . An air-conditioning apparatus, comprising:
 an outdoor unit including at least a compressor and a heat source side heat exchanger;   a heat medium relay unit including at least a heat exchanger related to heat medium, an expansion device, and a pump;   an indoor unit including at least a use side heat exchanger;   a refrigerant circuit being formed by refrigerant piping serially connecting the compressor, the heat source side heat exchanger, the expansion device, and a refrigerant side passage of the heat exchanger related to heat medium, the refrigerant circuit in which a heat source side refrigerant that transmits to a supercritical state circulates;   a heat medium circuit being formed by piping serially connecting a heat medium side passage of the heat exchanger related to heat medium, the pump, and the use side heat exchanger, the heat medium circuit in which a heat medium circulates;   a concentration detection device detecting a concentration of the refrigerant that has leaked from the refrigerant circuit, the concentration detection device being provided in the heat medium relay unit or in the installation space of the heat medium relay unit;   a shut off device that shuts off the circulation of the heat source side refrigerant on the basis of information from the concentration detection device, the shut off device being provided on both sides of refrigerant outlet and inlet in the heat medium relay; and   the shut off device makes an electrical component thereof driven by DC power supply, is in an opened state when energized, and is in a closed state when not energized.   
     
     
         3 . (canceled) 
     
     
         4 . The air-conditioning apparatus of  claim 1 , wherein the energization of the shut off device is turned off when the concentration of the heat source side refrigerant that is detected by the concentration detection device is at or more than a predetermined concentration. 
     
     
         5 . The air-conditioning apparatus of  claim 4 , wherein the predetermined concentration is set under a practical limit of leakage. 
     
     
         6 . (canceled) 
     
     
         7 . The air-conditioning apparatus of  claim 1 , wherein the shut off device includes a stepping motor as the electrical component. 
     
     
         8 . The air-conditioning apparatus of  claim 1 , wherein an amount of leakage of the heat source side refrigerant from the shut off device is 3.0×10 −9  (m 3 /sec) or less. 
     
     
         9 . The air-conditioning apparatus of  claim 1 , wherein during cooling operation the CV value of the shut off device disposed on the high-pressure side is 1 or more and the CV value of the shut off device disposed on the low-pressure side is 5 or more. 
     
     
         10 . The air-conditioning apparatus of  claim 1 , wherein a minimum operating pressure differential of the shut off device is at around 0 (kgf/cm 2 ). 
     
     
         11 . The air-conditioning apparatus of  claim 1 , wherein the shut off device is capable of passing the heat source side refrigerant in both directions. 
     
     
         12 . The air-conditioning apparatus of  claim 1 , wherein
 an electric power supply to the concentration detection device is from a commercial power supply or from a battery.