Refrigerated Case

Abstract

In a self-contained plug-in display cabinet system ( 100 ), the evaporation temperature of the evaporator ( 25 ) is between −4° C. and 2° C., and with the adaption of constant pre-cooling means ( 22 ), the high-temperature and high-pressure refrigerant gas discharged by the compressor ( 21 ) is pre-cooled allowing use of a low system pressure ratio and, thus, a high temperature compressor ( 21 ). Furthermore, there may be no need for the evaporator to be defrosted, which overcomes the drawbacks of the currently available display cabinet systems that the refrigeration cycles have to be interrupted for defrosting the evaporator, thereby having further energy saving and being advantageous in keeping the temperature of the food stable.

1 . A self contained plug in display cabinet system ( 100 ), characterized in that the system comprises:
 a display cabinet ( 110 ) containing a product display area ( 140 ) and a compartment ( 120 ,  130 ) separated from the display area;   an airflow circulation channel ( 112 ,  114 ,  116 ) connecting the airflow between the display area and the compartment of the display cabinet; and   a refrigeration system ( 20 ) disposed in the compartment of the display cabinet and comprising an air-conditioning compressor ( 21 ), a condenser ( 23 ), a throttling mechanism ( 24 ), an evaporator ( 25 ), and pipelines ( 26 ) connecting these parts, wherein the evaporation temperature of the evaporator is −4° C. to 2° C.   
     
     
         2 . The self-contained plug-in display cabinet system as claimed in  claim 1 , characterized in that the suction temperature (SST) of said air-conditioning compressor is above −5° C. 
     
     
         3 . The self-contained plug-in display cabinet system as claimed in  claim 1 , characterized in that said refrigeration system further comprises condensed water evaporating and cooling means for pre-cooling the high-temperature and high-pressure refrigerant flowing out of the outlet of the air-conditioning compressor. 
     
     
         4 . The self-contained plug-in display cabinet system as claimed in  claim 3 , characterized in that said condensed water evaporating and cooling means comprises a cooling water container and a coiled evaporation pipe disposed within the cooling water container, and said cooling water container can collect and contain the water condensed on the surface of heat exchange fins of the evaporator for pre-cooling the refrigerant. 
     
     
         5 . The self-contained plug-in display cabinet system as claimed in  claim 4 , characterized in that said display cabinet contains a first compartment connected with the airflow circulation channel, and said evaporator is disposed in the first compartment of the display cabinet. 
     
     
         6 . The self-contained plug-in complete display cabinet system as claimed in  claim 5 , characterized in that said display cabinet further contains a second compartment, and said air-conditioning compressor, condensed water evaporating and cooling means, condenser and throttling mechanism are disposed in the second compartment. 
     
     
         7 . A refrigerating system, characterized in that it comprises an air-conditioning compressor, a condenser, a throttling mechanism, an evaporator and pipelines connecting the parts, wherein the evaporation temperature of the evaporator is −4 to 2° C. 
     
     
         8 . The refrigerating system as claimed in  claim 7 , characterized in that the saturated suction temperature of said air-conditioning compressor is above −5° C. 
     
     
         9 . The refrigerating system as claimed in  claim 7 , characterized in that it further comprises condensed water evaporating and cooling means for pre-cooling the high-temperature and high-pressure refrigerant flowing out of the outlet of the air-conditioning compressor. 
     
     
         10 . The refrigerating system as claimed in  claim 9 , characterized in that said condensed water evaporating and cooling means comprises a cooling water container and an coiled evaporation pipe disposed within said cooling water container, and said cooling water container can collect and contain the water condensed on the surface of heat exchange fins of the evaporator for pre-cooling the refrigerant. 
     
     
         11 . A method for operating a refrigerated display cabinet system, the system comprising:
 a display cabinet ( 110 ) containing a product display area ( 140 ); and   a refrigeration system ( 20 ) comprising a compressor ( 21 ), a heat rejection heat exchanger ( 23 ), an expansion device ( 24 ), and an evaporator ( 25 ),   the method comprising:   pre-cooling refrigerant flowing from the compressor to the condenser via condensate collected from the evaporator, the pre-cooling effective to maintain an evaporation temperature of the evaporator of −4° C. to 2° C.   
     
     
         12 . The method of  claim 11  wherein:
 at least 50% of the pre-cooling occurs before at least 50% of an air cooling of refrigerant in the condenser.   
     
     
         13 . The method of  claim 11  wherein:
 the condensate is continuously collected over at least 90% of an operational cycle.   
     
     
         14 . The method of  claim 13  wherein:
 there is no defrosting.   
     
     
         15 . The method of  claim 13  wherein:
 a characteristic operational system pressure ratio is 2.4-2.8.