Air conditioning system

Abstract

An air conditioning system includes a refrigerant circuit, a heat exchanger, a shutoff valve, and a refrigerant leakage sensor. The refrigerant circuit includes a first part and a second part. The heat exchanger is provided in the first part and exchanges heat between a refrigerant and air in an air conditioning target space. The shutoff valve is provided in the refrigerant circuit and shuts off communication between the first part and the second part. The refrigerant leakage sensor detects that refrigerant concentration is within a first range and detects the refrigerant leaked from the first part. The shutoff valve is placed to set the refrigerant concentration in the air conditioning target space within a second range larger than the first range, when it is assumed that all the refrigerant present in the first part has leaked to the air conditioning target space.

1 . An air conditioning system comprising:
 a refrigerant circuit including a first part and a second part;   a heat exchanger provided in the first part and configured to cool or heat air in an air conditioning target space by exchanging heat between a refrigerant and the air in the air conditioning target space;   a shutoff valve provided in the refrigerant circuit and configured to shut off communication between the first part and the second part; and   a refrigerant leakage sensor configured to detect the refrigerant leaked from the first part,   wherein   the refrigerant leakage sensor detects that refrigerant concentration is within a first range, and   the shutoff valve is placed to set the refrigerant concentration in the air conditioning target space within a second range that is a range larger than the first range when it is assumed that all the refrigerant present in the first part has leaked to the air conditioning target space.   
     
     
         2 . The air conditioning system according to  claim 1 , wherein
 when a lower limit concentration of combustion of the refrigerant is LFL [kg/m 3 ],   the first range is from LFL/X1 to LFL/X2,   the second range is from LFL/Y1 to LFL/Y2, and   X1 is larger than Y1, and X2 is larger than Y2.   
     
     
         3 . The air conditioning system according to  claim 1 , wherein
 the refrigerant circuit includes a utilization-side refrigerant flow path that is part of the first part, a heat source-side refrigerant flow path that is part of the second part, and a first connection flow path and a second connection flow path connecting the utilization-side refrigerant flow path to the heat source-side refrigerant flow path,   the shutoff valve includes a first shutoff valve provided in the first connection flow path and a second shutoff valve provided in the second connection flow path,   the first connection flow path includes a utilization-side first connection flow path between the utilization-side refrigerant flow path and the first shutoff valve, and a heat source-side first connection flow path between the heat source-side refrigerant flow path and the first shutoff valve,   the second connection flow path includes a utilization-side second connection flow path between the utilization-side refrigerant flow path and the second shutoff valve, and a heat source-side second connection flow path between the heat source-side refrigerant flow path and the second shutoff valve, and   the first shutoff valve and the second shutoff valve are placed based on volume of the utilization-side refrigerant flow path, volume of the utilization-side first connection flow path, volume of the utilization-side second connection flow path, and volume of the air conditioning target space.   
     
     
         4 . The air conditioning system according to  claim 2 , wherein
 the refrigerant circuit includes a utilization-side refrigerant flow path that is part of the first part, a heat source-side refrigerant flow path that is part of the second part, and a first connection flow path and a second connection flow path connecting the utilization-side refrigerant flow path to the heat source-side refrigerant flow path,   the shutoff valve includes a first shutoff valve provided in the first connection flow path and a second shutoff valve provided in the second connection flow path,   the first connection flow path includes a utilization-side first connection flow path between the utilization-side refrigerant flow path and the first shutoff valve, and a heat source-side first connection flow path between the heat source-side refrigerant flow path and the first shutoff valve,   the second connection flow path includes a utilization-side second connection flow path between the utilization-side refrigerant flow path and the second shutoff valve, and a heat source-side second connection flow path between the heat source-side refrigerant flow path and the second shutoff valve, and   the first shutoff valve and the second shutoff valve are placed based on volume of the utilization-side refrigerant flow path, volume of the utilization-side first connection flow path, volume of the utilization-side second connection flow path, and volume of the air conditioning target space.