Refrigeration apparatus

Abstract

A refrigeration apparatus includes a first heat exchanger, a compressor, and an expansion valve that are located in an outdoor space and connected to first piping that allows a first working medium to circulate through the first heat exchanger, the compressor, and the expansion valve (outdoor-side circuit). The refrigeration apparatus includes a second heat exchanger located in an indoor space and connected to second piping that allows a second working medium to circulate through the second heat exchanger (indoor-side circuit). The refrigeration apparatus further includes a secondary heat exchanger located between the first piping and the second piping and in the outdoor space to effect heat exchange between the first working medium and the second working medium. The first working medium contains at least a fluoroolefin, and the second working medium contains no fluoroolefin.

1 . A refrigeration apparatus comprising:
 a first heat exchanger;   a second heat exchanger;   a compressor; and   an expansion mechanism, wherein   the first heat exchanger, the compressor, and the expansion mechanism are located in an outdoor space and connected to first piping that allows a first working medium to circulate through the first heat exchanger, the compressor, and the expansion mechanism, the first heat exchanger, the compressor, the expansion mechanism, and the first piping constituting an outdoor-side circuit,   the second heat exchanger is located in an indoor space and connected to second piping that allows a second working medium to circulate through the second heat exchanger, the second heat exchanger and the second piping constituting an indoor-side circuit,   the refrigeration apparatus further comprises a secondary heat exchanger located between the first piping and the second piping to effect heat exchange between the first working medium and the second working medium,   the secondary heat exchanger is located in the outdoor space,   the first working medium contains at least a fluoroolefin, and   the second working medium contains no fluoroolefin.   
     
     
         2 . The refrigeration apparatus according to  claim 1 , further comprising bypass piping connected to the first piping in parallel to the secondary heat exchanger and including a shut-off valve, wherein
 the bypass piping is located in the outdoor space.   
     
     
         3 . The refrigeration apparatus according to  claim 1 , wherein
 the indoor-side circuit includes
 a pump that pumps the second working medium to the second heat exchanger, and 
 an indoor-side inflow shut-off valve that blocks inflow of the second working medium into the secondary heat exchanger, and 
   the pump is stopped in case that the indoor-side inflow shut-off valve blocks the inflow of the second working medium.   
     
     
         4 . The refrigeration apparatus according to  claim 1 , wherein
 the indoor-side circuit further includes a gas-liquid separator connected to the second piping and located in the outdoor space, and   the gas-liquid separator includes a safety valve that discharges a gas at a predetermined pressure.   
     
     
         5 . The refrigeration apparatus according to  claim 4 , wherein
 the indoor-side circuit further includes an indoor-side outflow shut-off valve located to block outflow from the gas-liquid separator.   
     
     
         6 . The refrigeration apparatus according to  claim 2 , further comprising:
 a controller; and   a first working medium temperature detector that measures a temperature of the first working medium flowing in the first piping, wherein   the controller opens the shut-off valve of the bypass piping in case that the temperature measured by the first working medium temperature detector has reached a predetermined temperature.   
     
     
         7 . The refrigeration apparatus according to  claim 2 , further comprising:
 a controller; and   a first working medium temperature detector that measures a temperature of the first working medium flowing in the first piping, wherein   the outdoor-side circuit further includes an outdoor-side flow shut-off valve that blocks inflow of the first working medium into the secondary heat exchanger and outflow of the first working medium from the secondary heat exchanger, and   the controller closes the outdoor-side flow shut-off valve and stops operation of the outdoor-side circuit in case that the temperature measured by the first working medium temperature detector has reached a predetermined temperature.   
     
     
         8 . The refrigeration apparatus according to  claim 1 , wherein
 the secondary heat exchanger is a plate heat exchanger, a double pipe heat exchanger, or a shell-and-tube heat exchanger.   
     
     
         9 . The refrigeration apparatus according to  claim 8 , wherein
 the first working medium is a refrigerant mixture containing propane in addition to the fluoroolefin.   
     
     
         10 . The refrigeration apparatus according to  claim 1 , wherein
 the first working medium further contains a disproportionation inhibitor.   
     
     
         11 . The refrigeration apparatus according to  claim 8 , wherein
 the second working medium is a liquid refrigerant or a low-pressure refrigerant.