Refrigeration System with Hot Gas Defrost Mode

Abstract

The present application provides a refrigeration system with a flow of refrigerant therein for a refrigerant mode or a defrost mode. The refrigeration system may include a four way valve, an evaporator in communication with the four way valve, a compressor in communication with the four way valve, and a condenser in communication with the four way valve. The four way valve directs the flow of refrigerant to the condenser in the refrigeration mode or to the evaporator in the defrost mode.

We claim: 
     
         1 . A refrigeration system with a flow of refrigerant therein, comprising:
 a four way valve;   an evaporator in communication with the four way valve;   a compressor in communication with the four way valve; and   a condenser in communication with the four way valve;   wherein the four way valve directs the flow of refrigerant to the condenser in a refrigeration mode or to the evaporator in a defrost mode.   
     
     
         2 . The refrigeration system of  claim 1 , further comprising a suction accumulator in communication with the four way valve and the compressor. 
     
     
         3 . The refrigeration system of  claim 1 , further comprising a receiver in communication with the condenser. 
     
     
         4 . The refrigeration system of  claim 3 , wherein the receiver is in communication with the condenser via a refrigerant receiver conduit in the refrigeration mode and a defrost receiver conduit in the defrost mode. 
     
     
         5 . The refrigeration system of  claim 4 , wherein the defrost receiver conduit comprises an electronic pressure regulator thereon to modulate the flow of refrigerant to the condenser in the defrost mode. 
     
     
         6 . The refrigeration system of  claim 3 , further comprising a sub-cooler in communication with the receiver and the evaporator. 
     
     
         7 . The refrigeration system of  claim 6 , wherein the sub-cooler is in communication with the receiver via a sub-cooler input conduit. 
     
     
         8 . The refrigeration system of  claim 6 , wherein the sub-cooler is in communication with the evaporator via a sub-cooler output conduit. 
     
     
         9 . The refrigeration system of  claim 3 , wherein the receiver is in communication with the evaporator via a sub-cooler bypass conduit in the defrost mode. 
     
     
         10 . The refrigeration system of  claim 3 , further comprising an evaporator bypass conduit in communication with the four way valve and the receiver in the defrost mode. 
     
     
         11 . The refrigeration system of  claim 1 , further comprising an electronic expansion valve in communication with the evaporator in the refrigeration mode to modulate the flow of refrigerant thereto. 
     
     
         12 . The refrigeration system of  claim 1 , further comprising a drain pan loop in communication with the four way valve and the evaporator in the defrost mode. 
     
     
         13 . The refrigeration system of  claim 1 , further comprising one or more filter driers. 
     
     
         14 . The refrigeration system of  claim 1 , further comprising a plurality of temperature sensors and a plurality of pressure sensors. 
     
     
         15 . A method of operating a refrigeration system, comprising:
 directing a flow of refrigerant by a four way valve to a condenser and then to an evaporator in a refrigeration mode;   modulating the flow of refrigerant to the evaporator with an electronic expansion valve in the refrigeration mode;   directing the flow refrigerant by the four way valve to the evaporator and then to the condenser in a defrost mode; and   modulating the flow of refrigerant to the condenser with an electronic pressure regulator in the defrost mode.   
     
     
         16 . A refrigeration system with a flow of refrigerant therein, comprising:
 a four way valve;   an evaporator in communication with the four way valve;   a condenser in communication with the four way valve;   wherein the four way valve directs the flow of refrigerant to the condenser in a refrigeration mode or to the evaporator in a defrost mode;   an electronic expansion valve for modulating the flow of refrigerant to the evaporator in the refrigeration mode; and   an electronic pressure regulator for modulating the flow of refrigerant to the condenser in the defrost mode.   
     
     
         17 . The refrigeration system of  claim 16 , further comprising a compressor and a suction accumulator in communication with the four way valve. 
     
     
         18 . The refrigeration system of  claim 16 , further comprising a receiver in communication with the condenser and the evaporator. 
     
     
         19 . The refrigeration system of  claim 18 , wherein the receiver is in communication with the condenser via a refrigerant receiver conduit in the refrigeration mode and a defrost receiver conduit for use defrost mode. 
     
     
         20 . The refrigeration system of  claim 18 , further comprising an evaporator bypass conduit in communication with the four way valve and the receiver in the defrost mode.