Cooling and heating system

Abstract

There is disclosed a cooling and heating system in which a refrigerant is used in a supercritical state and in which cooling and heating capacity can be controlled so as to maximize a coefficient of performance. A cooling and heating system 130 includes: an outdoor unit 101 indicating a compressor 102 and an outdoor heat exchanger 103 a ; a plurality of indoor units 105 including indoor heat exchangers 106 ; a high pressure tube 111 ; a low pressure tube 112 ; and an intermediate tube 113 . The system includes: a refrigerant pressure detection unit P C01 for measuring a pressure of the refrigerant discharged from the compressor 102 ; a first refrigerant temperature detection unit T C03 which measures an outlet temperature of the refrigerant in a case where the outdoor heat exchanger 103 functions as a gas cooler and which measures an inlet temperature of the refrigerant in a case where the outdoor heat exchanger 103 functions as an evaporator; and a second refrigerant temperature detection unit T CO8 which measures an outlet temperature of the refrigerant in a case where the indoor heat exchanger 106 functions as a gas cooler and which measures an inlet temperature of the refrigerant in a case where the indoor heat exchanger 106 functions as an evaporator.

1 . A cooling and heating system including: an outdoor unit including a compressor and an outdoor heat exchanger; and a plurality of indoor units including indoor heat exchangers and connected to one another by a pipe between the units, one end of the outdoor heat exchanger being selectively connected to a refrigerant discharge tube and a refrigerant suction tube of the compressor, the pipe between the units including: a high pressure tube connected to the refrigerant discharge tube; a low pressure tube connected to the refrigerant suction tube; and an intermediate pressure tube connected to the other end of the outdoor heat exchanger, one end of the indoor heat exchanger of each indoor unit being selectively connected to the high pressure tube and the low pressure tube, the other end of the indoor heat exchanger being connected to the intermediate pressure tube, the plurality of indoor units being simultaneously allowed to perform a cooling operation or a heating operation or the plurality of indoor units being allowed to perform a cooling operation and a heating operation simultaneously in a mixed manner, 
 the cooling and heating system comprising:    refrigerant pressure measurement means for measuring a pressure of the refrigerant discharged from the compressor;    first refrigerant temperature measurement means which is disposed in the outdoor unit and which measures an outlet temperature of the refrigerant in a case where the outdoor heat exchanger functions as a gas cooler and which measures an inlet temperature of the refrigerant in a case where the outdoor heat exchanger functions as an evaporator; and    second refrigerant temperature measurement means which is disposed in the indoor unit and which measures an outlet temperature of the refrigerant in a case where the indoor heat exchanger functions as a gas cooler and which measures an inlet temperature of the refrigerant in a case where the indoor heat exchanger functions as an evaporator.    
   
   
       2 . A cooling and heating system including: an outdoor unit including a compressor and an outdoor heat exchanger; and a plurality of indoor units including indoor heat exchangers and connected to one another by a pipe between the units, one end of the outdoor heat exchanger being selectively connected to a refrigerant discharge tube and a refrigerant suction tube of the compressor, the pipe between the units including: a high pressure tube connected to the refrigerant discharge tube; a low pressure tube connected to the refrigerant suction tube; and an intermediate pressure tube connected to the other end of the outdoor heat exchanger, one end of the indoor heat exchanger of each indoor unit being selectively connected to the high pressure tube and the low pressure tube, the other end of the indoor heat exchanger being connected to the intermediate pressure tube, the plurality of indoor units being simultaneously allowed to perform a cooling operation or a heating operation or the plurality of indoor units being allowed to perform a cooling operation and a heating operation simultaneously in a mixed manner, 
 the cooling and heating system comprising:    discharge temperature measurement means for measuring a temperature of the refrigerant discharged from the compressor;    first refrigerant temperature measurement means which is disposed in the outdoor unit and which measures an outlet temperature of the refrigerant in a case where the outdoor heat exchanger functions as a gas cooler and which measures an inlet temperature of the refrigerant in a case where the outdoor heat exchanger functions as an evaporator; and    second refrigerant temperature measurement means which is disposed in the indoor unit and which measures an outlet temperature of the refrigerant in a case where the indoor heat exchanger functions as a gas cooler and which measures an inlet temperature of the refrigerant in a case where the indoor heat exchanger functions as an evaporator.    
   
   
       3 . The cooling and heating system according to  claim 1  or  2 , 
 wherein the high side pressure of the refrigeration cycle is above the critical pressure of the refrigerant during the operation of the cooling and heating system.    
   
   
       4 . The cooling and heating system according to  claim 3 , wherein carbon dioxide is used as the refrigerant.