Heat source unit and refrigeration apparatus

Abstract

A heat source unit includes a controller configured to control the subcooling-side decompression valve according to a degree of subcooling of a refrigerant flowing out of the first flow path of the subcooling heat exchanger. Under a condition that the opening degree of a subcooling-side decompression valve is equal to or greater than a predetermined opening degree, the controller determines that there is a shortage of a refrigerant in the refrigerant circuit.

1 . A heat source unit, comprising:
 a refrigerant circuit including a compression unit, a heat-source-side heat exchanger, a subcooling-side decompression valve, and a subcooling heat exchanger having a first flow path and a second flow path, where the first flow path is a flow path through which a refrigerant having dissipated heat in the heat-source-side heat exchanger flows, and where the second flow path is a flow path through which a refrigerant passing through the first flow path and then decompressed by the subcooling-side decompression valve flows; and   a controller configured to control the subcooling-side decompression valve according to a degree of subcooling of a refrigerant flowing out of the first flow path of the subcooling heat exchanger, wherein   based on a fact that an opening degree of the subcooling-side decompression valve becomes larger, the controller determines whether there is a shortage of a refrigerant in the refrigerant circuit.   
     
     
         2 . The heat source unit of  claim 1 , wherein
 under a condition that the opening degree of a subcooling-side decompression valve is equal to or greater than a predetermined opening degree, the controller determines that there is a shortage of a refrigerant in the refrigerant circuit.   
     
     
         3 . The heat source unit of  claim 2 , wherein
 under a condition that the opening degree of the subcooling-side decompression valve continues to remain equal to or greater than a predetermined opening degree for a predetermined duration time or more, the controller determines that there is a shortage of a refrigerant.   
     
     
         4 . The heat source unit of  claim 3 , wherein
 under a condition that the opening degree of the subcooling-side decompression valve continues to remain equal to or greater than a first opening degree for a first duration time or more, or under a condition that the opening degree of the subcooling-side decompression valve continues to remain equal to or greater than a second opening degree for a second duration time or more, the controller determines that there is a shortage of a refrigerant,   the second duration time is longer than the first duration time, and   the second opening degree is smaller than the first opening degree.   
     
     
         5 . The heat source unit of  claim 1 , wherein
 under a condition that the opening degree of the subcooling-side decompression valve is the opening degree of the subcooling-side decompression valve that is fully opened, the controller determines that there is a shortage of a refrigerant in the refrigerant circuit.   
     
     
         6 . The heat source unit of  claim 1 , wherein
 the refrigerant circuit is configured to be able to perform a refrigeration cycle in which a high pressure is equal to or greater than a critical pressure.   
     
     
         7 . The heat source unit of  claim 1 , wherein
 the refrigerant circuit is provided with a gas-liquid separator between the heat-source-side heat exchanger and the first flow path of the subcooling heat exchanger.   
     
     
         8 . A refrigeration apparatus, comprising:
 the heat source unit of  claim 1 ; and   a utilization unit.