Refrigerating apparatus

Abstract

A refrigerating apparatus includes a refrigerating cycle including a compressor, a condenser, a flow divider, a first heat exchanger, a second heat exchanger, a decompressing device, and an evaporator. The refrigerant cycle has sealed therein a mixed refrigerant obtained by mixing at least first to third refrigerants with different evaporation temperatures. The first heat exchanger and the second heat exchanger each includes a double pipe to form a first flow passage in an inner pipe of the double pipe, a second flow passage in an outer pipe of the double pipe, and an intermediate port in a piping connecting between the second flow passage of the first heat exchanger and the second flow passage of the second heat exchanger. A high-temperature and high-pressure refrigerant discharged from the compressor is cooled by the condenser to liquefy the first refrigerant having a high evaporation temperature into a liquid refrigerant.

1 . A refrigerating apparatus comprising:
 a refrigerating cycle including a compressor, a condenser, a flow divider, a first heat exchanger, a second heat exchanger, a decompressing device, and an evaporator, connected circularly with a refrigerant piping, the refrigerant cycle having sealed therein a mixed refrigerant obtained by mixing at least first to third refrigerants with different evaporation temperatures,   the first heat exchanger and the second heat exchanger each including a double pipe to form a first flow passage in an inner pipe of the double pipe, a second flow passage in an outer pipe of the double pipe, and an intermediate port in a piping connecting between the second flow passage of the first heat exchanger and the second flow passage of the second heat exchanger,   a high-temperature and high-pressure refrigerant discharged from the compressor being cooled by the condenser to liquefy the first refrigerant having a high evaporation temperature into a liquid refrigerant, and thereafter,
 the liquid refrigerant obtained by dividing a refrigerant in the flow divider being decompressed, and thereafter supplied to the second flow passage of the first heat exchanger via the intermediate port, evaporated toward one port of the second flow passage, and supplied to a sucking side of the compressor via the one port of the second flow passage of the first heat exchanger, 
 a gas-state refrigerant obtained by dividing a refrigerant in the flow divider being supplied to the first flow passage of the first heat exchanger, and thereafter passing through the first flow passage to liquefy the second refrigerant with an evaporation temperature lower than the evaporation temperature of the first refrigerant, and thereafter passing through the first flow passage of the second heat exchanger to liquefy the third refrigerant, and thereafter, via the decompressing device, passing through the evaporator to evaporate the second and third refrigerants, and thereafter passing through the second flow passage of the second heat exchanger and the second flow passage of the first heat exchanger, and thereafter departing from the other port of the second flow passage of the first heat exchanger via the one port and arriving at the sucking side of the compressor, and thereby 
   a refrigerant in the first flow passage of the first heat exchanger and the second heat exchanger and a refrigerant in the second flow passage of the first heat exchanger and the second heat exchanger having a countercurrent relationship, and having a temperature relationship in a manner that the refrigerant flowing through the second flow passage cools the refrigerant flowing through the first flow passage.   
     
     
         2 . The refrigerating apparatus according to  claim 1 , wherein
 a part of the third refrigerant is evaporated in the second flow passage of the second heat exchanger.   
     
     
         3 . The refrigerating apparatus according to  claim 1 , wherein
 the decompressing device includes a capillary tube, and the capillary tube is wound around a piping extending from the evaporator to the second heat exchanger.   
     
     
         4 . The refrigerating apparatus according to  claim 1 , further comprising:
 an insulation housing including an inner box whose boundary portion at least between both side plates and a back plate has a curved face, an outer box covering the inner box, and an insulation material filled between the inner box and the outer box;   an insulation door configured to open or close an opening at a front of the insulation housing; and   two refrigerating cycles including the refrigerating cycle according to  claim 1  as a first refrigerating cycle and a second refrigerating cycle, wherein   a first evaporation pipe constituting an evaporator of the first refrigerating cycle is attached to an outside of a top plate, the both side plates, the back plate, and a bottom plate of the inner box in such a manner that, as the first evaporation pipe goes from an upstream side to a downstream side of a flow of the refrigerant, the first evaporation pipe meanders outside the top plate, meanders outside the both side plates across a width extending through the both side plates and the back plate, further meanders outside the bottom plate, and wherein   a second evaporation pipe constituting an evaporator of the second refrigerating cycle is attached to an outside of the top plate, the both side plates, the back plate, and the bottom plate of the inner box in such a manner that as the second evaporation pipe goes from an upstream side to a downstream side of the flow of the refrigerant, the second evaporation pipe meanders outside the top plate so as not to overlap the first evaporation pipe, meanders outside the both side plates and the back plate across a width extending through the both side plates and the back plate from an upper side to a lower side, further meanders outside the bottom plate.   
     
     
         5 . The refrigerating apparatus according to  claim 4 , wherein
 the first evaporation pipe and the second evaporation pipe alternately meander outside the top plate, the both side plates, the back plate, and the bottom plate.