Refrigerated display case systems

Abstract

A refrigerated display case system includes a display case that defines an inner volume; a closed-circuit refrigeration system; and a control system. The closed-circuit refrigeration system includes a compressor; a condenser assembly; and a cooling assembly that includes a cooling coil and an evaporator fan configured to circulate an airflow from the inner volume through the cooling coil to cool the airflow with a liquid phase of a hydrocarbon refrigerant supplied from the condensing unit. The evaporator fan is configured to circulate the cooled airflow to the inner volume to adjust or maintain a temperature of the inner volume. The control system is configured to perform operations including operating the condensing unit and the cooling assembly in a refrigeration cycle to cool the inner volume and a defrost cycle to defrost the cooling assembly; and operating the evaporator fan independent of the refrigeration cycle and the defrost cycle.

What is claimed is: 
     
         1 . A refrigerated display case system, comprising:
 a display case that defines an inner volume configured to store one or more perishable items;   a closed-circuit refrigeration system, comprising:
 a condensing unit comprising at least one compressor and at least one condenser assembly; and 
 a cooling assembly that comprises at least one cooling coil and at least one evaporator fan configured to circulate an airflow from the inner volume through the at least one cooling coil to cool the airflow with a liquid phase of a hydrocarbon refrigerant supplied from the condensing unit, the at least one evaporator fan configured to circulate the cooled airflow to the inner volume to adjust or maintain a temperature of the inner volume; and 
   a control system communicably coupled to the cooling assembly and the condensing unit and configured to perform operations comprising:
 operating the condensing unit and the cooling assembly in a refrigeration cycle to cool the inner volume and a defrost cycle to defrost the cooling assembly; and 
 operating the evaporator fan independent of the refrigeration cycle and the defrost cycle. 
   
     
     
         2 . The refrigerated display case system of  claim 1 , wherein the condensing unit comprises at least one condenser fan, and the control system is configured to perform operations comprising:
 operating the condenser fan independent of the refrigeration cycle and the defrost cycle.   
     
     
         3 . The refrigerated display case system of  claim 1 , wherein the hydrocarbon refrigerant comprises propane. 
     
     
         4 . The refrigerated display case system of  claim 1 , wherein the condensing unit comprises a panel positioned in an interior volume of the condensing unit to separate the interior volume into a first plenum and a second plenum that is substantially fluidly separated from the first plenum, the at least one compressor and at least one condenser assembly positioned in the first plenum and an electrical junction box positioned in the second plenum. 
     
     
         5 . A refrigerated display case system, comprising:
 a display case that defines an inner volume configured to store one or more perishable items;   a closed-circuit refrigeration system, comprising:
 a condensing unit comprising at least one compressor and at least one condenser assembly that includes a condenser fan; and 
 a cooling assembly that comprises at least one cooling coil and at least one evaporator fan configured to circulate an airflow from the inner volume through the at least one cooling coil to cool the airflow with a liquid phase of a hydrocarbon refrigerant supplied from the condensing unit, the at least one evaporator fan configured to circulate the cooled airflow to the inner volume to adjust or maintain a temperature of the inner volume; and 
   a control system communicably coupled to the cooling assembly and the condensing unit and configured to perform operations comprising:
 operating the condensing unit and the cooling assembly in a refrigeration cycle to cool the inner volume and a defrost cycle to defrost the cooling assembly; and 
 operating the condenser fan independent of the refrigeration cycle and the defrost cycle. 
   
     
     
         6 . The refrigerated display case system of  claim 5 , wherein the control system is configured to perform operations comprising:
 operating the evaporator fan independent of the refrigeration cycle and the defrost cycle.   
     
     
         7 . The refrigerated display case system of  claim 5 , wherein the hydrocarbon refrigerant comprises propane. 
     
     
         8 . The refrigerated display case system of  claim 5 , wherein the condensing unit comprises a panel positioned in an interior volume of the condensing unit to separate the interior volume into a first plenum and a second plenum that is substantially fluidly separated from the first plenum, the at least one compressor and at least one condenser assembly positioned in the first plenum and an electrical junction box positioned in the second plenum. 
     
     
         9 . A refrigerated display case system, comprising:
 a display case that defines an inner volume configured to store one or more perishable items;   a closed-circuit refrigeration system, comprising:
 a condensing unit comprising at least one compressor and at least one condenser assembly that includes at least one condenser fan; and 
 a cooling assembly that comprises at least one cooling coil and at least one evaporator fan configured to circulate an airflow from the inner volume through the at least one cooling coil to cool the airflow with a liquid phase of a hydrocarbon refrigerant supplied from the condensing unit, the at least one evaporator fan configured to circulate the cooled airflow to the inner volume to adjust or maintain a temperature of the inner volume; 
   at least one exhaust fan positioned adjacent or near the display case; and   a control system communicably coupled to the cooling assembly, the condensing unit, and the at least one exhaust fan, the control system configured to perform operations comprising:
 operating the condensing unit and the cooling assembly in a refrigeration cycle to cool the inner volume and a defrost cycle to defrost the cooling assembly; and 
 operating the at least one exhaust fan independent of the refrigeration cycle and the defrost cycle. 
   
     
     
         10 . The refrigerated display case system of  claim 9 , wherein the control system is configured to perform operations comprising:
 operating the at least one condenser fan independent of the refrigeration cycle and the defrost cycle.   
     
     
         11 . The refrigerated display case system of  claim 9 , wherein the control system is configured to perform operations comprising:
 operating the at least one evaporator fan independent of the refrigeration cycle and the defrost cycle.   
     
     
         12 . The refrigerated display case system of  claim 9 , comprising a conduit coupled to the at least one exhaust fan. 
     
     
         13 . The refrigerated display case system of  claim 12 , wherein the conduit comprises an inlet at or near a low point of the inner volume and an outlet external to the display case. 
     
     
         14 . The refrigerated display case system of  claim 13 , wherein the low point is at or near a condensate drain of the display case. 
     
     
         15 . The refrigerated display case system of  claim 9 , wherein the at least one exhaust fan is mounted at or on a top portion of the display case. 
     
     
         16 . The refrigerated display case system of  claim 9 , wherein the hydrocarbon refrigerant comprises propane. 
     
     
         17 . The refrigerated display case system of  claim 9 , wherein the condensing unit comprises a panel positioned in an interior volume of the condensing unit to separate the interior volume into a first plenum and a second plenum that is substantially fluidly separated from the first plenum, the at least one compressor and at least one condenser assembly positioned in the first plenum and an electrical junction box positioned in the second plenum. 
     
     
         18 . A refrigerated display case system, comprising:
 a display case that defines an inner volume configured to store one or more perishable items;   a closed-circuit refrigeration system, comprising:
 a condensing unit comprising at least one compressor and at least one condenser assembly that includes at least one condenser fan; and 
 a cooling assembly that comprises at least one cooling coil and at least one evaporator fan configured to circulate an airflow from the inner volume through the at least one cooling coil to cool the airflow with a liquid phase of a hydrocarbon refrigerant supplied from the condensing unit, the at least one evaporator fan configured to circulate the cooled airflow to the inner volume to adjust or maintain a temperature of the inner volume; 
   a refrigerant leak detection sensor; and   a control system communicably coupled to the cooling assembly, the condensing unit, and the refrigerant leak detection sensor, the control system configured to perform operations comprising:
 operating the condensing unit and the cooling assembly in a refrigeration cycle to cool the inner volume; and 
 operating at least one of the condensing unit or the cooling assembly in a defrost cycle to defrost the cooling assembly. 
   
     
     
         19 . The refrigerated display case system of  claim 18 , wherein the refrigerant leak detection sensor comprises a refrigerant gas sensor, and the operations comprise:
 determining that the refrigerant gas sensor detects a refrigerant leak greater than a specified leak threshold; and   based on the determination, operating at least one of the evaporator fan, the condenser fan, or an exhaust fan independent of the refrigeration cycle and the defrost cycle.   
     
     
         20 . The refrigerated display case system of  claim 18 , wherein the refrigerant leak detection sensor comprises a door open sensor or case proximity sensor or motion sensor, and the operations comprise:
 determining that the door open sensor or case proximity sensor or motion sensor is tripped; and   based on the determination, operating at least one of the evaporator fan, the condenser fan, or an exhaust fan independent of the refrigeration cycle and the defrost cycle.   
     
     
         21 . The refrigerated display case system of  claim 18 , wherein the refrigerant leak detection sensor comprises a refrigerant suction pressure sensor, and the operations comprise:
 determining that a value of a refrigerant suction pressure determined by the refrigerant suction pressure sensor is less than a specified value; and   based on the determination, operating at least one of the evaporator fan, the condenser fan, or an exhaust fan independent of the refrigeration cycle and the defrost cycle.   
     
     
         22 . The refrigerated display case system of  claim 18 , wherein the hydrocarbon refrigerant comprises propane. 
     
     
         23 . The refrigerated display case system of  claim 18 , wherein the condensing unit comprises a panel positioned in an interior volume of the condensing unit to separate the interior volume into a first plenum and a second plenum that is substantially fluidly separated from the first plenum, the at least one compressor and at least one condenser assembly positioned in the first plenum and an electrical junction box positioned in the second plenum. 
     
     
         24 . A refrigerated display case system, comprising:
 a display case that defines an inner volume configured to store one or more perishable items;   a closed-circuit refrigeration system, comprising:
 a condensing unit comprising at least one compressor and at least one condenser assembly that includes at least one condenser fan; and 
 a cooling assembly that comprises at least one cooling coil and at least one evaporator fan configured to circulate an airflow from the inner volume through the at least one cooling coil to cool the airflow with a liquid phase of a hydrocarbon refrigerant supplied from the condensing unit, the at least one evaporator fan configured to circulate the cooled airflow to the inner volume to adjust or maintain a temperature of the inner volume; 
   a condensing unit housing that at least partially encloses the condensing unit on a top portion of the display case; and   a refrigerant piping chase that extends at or adjacent the condensing unit housing to at or adjacent the cooling assembly, the refrigerant piping chase configured to at least partially enclose one or more refrigerant piping conduits between the condensing unit and the cooling assembly.   
     
     
         25 . The refrigerated display case system of  claim 24 , wherein the condensing unit comprises an airflow opening. 
     
     
         26 . The refrigerated display case system of  claim 24 , wherein the refrigerant piping chase comprises a first chase portion mounted on the top portion of the display case and a second case portion mounted to a back panel of the display case. 
     
     
         27 . The refrigerated display case system of  claim 24 , wherein the hydrocarbon refrigerant comprises propane. 
     
     
         28 . The refrigerated display case system of  claim 24 , wherein the condensing unit comprises a panel positioned in an interior volume of the condensing unit to separate the interior volume into a first plenum and a second plenum that is substantially fluidly separated from the first plenum, the at least one compressor and at least one condenser assembly positioned in the first plenum and an electrical junction box positioned in the second plenum. 
     
     
         29 . A refrigerated display case system, comprising:
 a display case that defines an inner volume configured to store one or more perishable items;   a closed-circuit refrigeration system, comprising:
 a condensing unit comprising at least one compressor and at least one condenser assembly that includes at least one condenser fan; and 
 a cooling assembly that comprises at least one cooling coil and at least one evaporator fan configured to circulate an airflow from the inner volume through the at least one cooling coil to cool the airflow with a liquid phase of a hydrocarbon refrigerant supplied from the condensing unit, the at least one evaporator fan configured to circulate the cooled airflow to the inner volume to adjust or maintain a temperature of the inner volume; 
   a grease and condensate trap assembly fluidly coupled to at least one drain of the display case, the grease and condensate trap assembly configured to receive liquid and particulates from the at least one drain and separate the liquid from the particulates; and   a condensate pump positioned in a liquid reservoir of the grease and condensate trap assembly and configured to circulate the separated liquid from the liquid reservoir to an evaporator pan of the condensing unit.   
     
     
         30 . The refrigerated display case system of  claim 29 , wherein the grease and condensate trap assembly comprises:
 a particulate reservoir separate from the liquid reservoir; and   a strainer positioned in the particulate reservoir.   
     
     
         31 . The refrigerated display case system of  claim 29 , wherein the at least one drain is positioned at a low point location of the display case. 
     
     
         32 . The refrigerated display case system of  claim 29 , wherein the hydrocarbon refrigerant comprises propane. 
     
     
         33 . The refrigerated display case system of  claim 29 , wherein the condensing unit comprises a panel positioned in an interior volume of the condensing unit to separate the interior volume into a first plenum and a second plenum that is substantially fluidly separated from the first plenum, the at least one compressor and at least one condenser assembly positioned in the first plenum and an electrical junction box positioned in the second plenum.