Air-conditioning apparatus

Abstract

In an air-conditioning apparatus, a heat source side heat exchanger, intermediate heat exchangers, and use side heat exchangers are formed in separate bodies respectively and adapted to be disposed at separate locations one another. In a heat medium circulation circuit where the intermediate heat exchanger and the use side heat exchanger are connected, temperature sensors are installed. An anti-freezing operation mode is provided in which, when the detection temperatures of the temperature sensors become equal to or lower than a set temperature Ts while a compressor or pumps are stopped, the heat medium is circulated to perform anti-freezing of the heat medium.

1 . An air-conditioning apparatus, comprising:
 an intermediate heat exchanger that exchanges heat between a refrigerant and a different heat medium from said refrigerant such as water and brine;   a refrigeration cycle that connects a compressor, a heat source side heat exchanger, at least one expansion valve, and a refrigerant side flow path of said intermediate heat exchanger via piping through which said refrigerant flows; and   a heat medium circulation circuit that connects a heat medium side flow path of said intermediate heat exchanger, a pump, and a use side heat exchanger via piping through which said heat medium flows,   a temperature sensor that detects a temperature of said heat medium, installed in said heat medium circulation circuit, wherein   said heat source side heat exchanger, said intermediate heat exchanger, and said use side heat exchanger are formed in separate bodies respectively, and   there is provided an anti-freezing operation mode in which anti-freezing operation of said heat medium is performed when a detection temperature of said temperature sensor becomes equal to or lower than a set temperature while said compressor or said pump is stopped, and wherein   as said intermediate heat exchanger, an intermediate heat exchanger that heats said heat medium and an intermediate heat exchanger that cools said heat medium are provided,   flow path switching valves that switch the flow path to each intermediate heat exchanger at the inlet side and outlet side of a heat medium side flow path of said use side heat exchanger are provided, and   in said anti-freezing operation mode for said heat medium, said flow path switching valves are controlled so that the heat medium from both the flow path connected with one of said intermediate heat exchangers and the flow path connected with the other intermediate heat exchanger is mixed by said flow path switching valves, and part of the mixed heat medium circulates in said heat medium circulation circuit corresponding to said temperature sensor that detected a temperature equal to or lower than said set temperature.   
     
     
         2 . The air-conditioning apparatus of  claim 1 , wherein
 in the anti-freezing operation mode of said heat medium, said temperature sensor is installed in an inlet side flow path or an outlet side flow path of said pump, said pump is operated corresponding to said intermediate heat exchanger corresponding to said temperature sensor that detected a temperature equal to or lower than said set temperature, and said heat medium is made to circulate using said heat medium circulation circuit.   
     
     
         3 . The air-conditioning apparatus of  claim 1 , wherein
 a bypass is connected between a heat medium inlet side flow path and a heat medium outlet side flow path of said use side heat exchanger to adjust said heat medium flowing through said use side heat exchanger, and   in the anti-freezing operation, said heat medium is made to circulate through said bypass.   
     
     
         4 . The air-conditioning apparatus of  claim 1 , wherein
 a high-temperature high-pressure refrigerant is made to flow into said intermediate heat exchanger corresponding to said temperature sensor that detected a temperature equal to or lower than said set temperature.   
     
     
         5 . (canceled) 
     
     
         6 . The air-conditioning apparatus of  claim 1 , wherein
 in the anti-freezing operation mode of said heat medium, a flow path switching valve is provided that switches the flow path according to a plurality of said intermediate heat exchangers to an inlet side and an outlet side of the heat medium side flow path of said use side heat exchanger, respectively,   said compressor is operated and part of a plurality of said intermediate heat exchangers is operated for heating the heat medium,   said flow path switching valve is switched and the heat medium is circulated from the intermediate heat exchanger for heating the heat medium to said intermediate heat exchanger corresponding to said temperature sensor that detected a temperature equal to or lower than said set temperature.   
     
     
         7 . The air-conditioning apparatus of  claim 1 , wherein
 a flow amount adjustment valve is installed at a heat medium inlet side flow path or a heat medium outlet side flow path of said use side heat exchanger, and before or as soon as said pump is operated, said flow amount adjustment valve is controlled in the direction in which a circulation flow path of said heat medium is established.   
     
     
         8 . (canceled)