Method and apparatus to control discharge cooling in a refrigeration system

Abstract

A method and apparatus for operating a discharge cooling cycle in a refrigeration system. The method includes determining a first operating condition of the refrigeration system. The method also includes, based on the determination of the operating condition, activating an evaporator fan for a first predetermined period of time, deactivating the evaporator fan for a second predetermined period of time, and repeating the activating and deactivating until a second operating condition is detected.

1 . A method of operating a refrigeration system, the method comprising:
 determining a first operating condition of the refrigeration system; and   based on the determination of the first operating condition,
 activating an evaporator fan for a first predetermined period of time, 
 deactivating the evaporator fan for a second predetermined period of time, and 
 repeating the activating and deactivating until a second operating condition is detected. 
   
     
     
         2 . The method of  claim 1 , wherein the first operating condition is a start of a pulldown state or a reload state, and the second operating condition is an end of the pulldown state or the reload state. 
     
     
         3 . The method of  claim 1 , wherein the first operating condition is a discharge gas temperature above a first predetermined level. 
     
     
         4 . The method of  claim 3 , wherein the second operating condition is the discharge gas temperature below a second predetermined level. 
     
     
         5 . The method of  claim 1 , wherein the first operating condition is an ambient temperature outside the refrigeration system above a predetermined level and the second operating condition is the ambient temperature outside the refrigeration system at or below the predetermined level. 
     
     
         6 . The method of  claim 1 , wherein the first predetermined period of time is approximately thirty minutes and the second predetermined period of time is approximately five minutes. 
     
     
         7 . The method of  claim 1 , wherein the refrigeration system is disposed in a vending machine. 
     
     
         8 . An apparatus, comprising:
 a refrigeration system comprising a compressor and an evaporator fan; and   a controller communicatively coupled to the refrigeration system, the controller configured to:   determine a first operating condition of the refrigeration system; and   based on the determination of the first operating condition,
 activate the evaporator fan for a first predetermined period of time, 
 deactivate the evaporator fan for a second predetermined period of time, and 
 repeat the activation and deactivation until a second operating condition is detected. 
   
     
     
         9 . The apparatus of  claim 8 , wherein the first operating condition is a start of a pulldown state or a reload state, and the second operating condition is an end of the pulldown state or the reload state. 
     
     
         10 . The apparatus of  claim 8 , wherein the first operating condition is a discharge gas temperature above a first predetermined level. 
     
     
         11 . The apparatus of  claim 10 , wherein the second operating condition is the discharge gas temperature below a second predetermined level. 
     
     
         12 . The apparatus of  claim 8 , wherein the first operating condition is an ambient temperature outside the refrigeration system above a predetermined level and the second operating condition is the ambient temperature outside the refrigeration system at or below the predetermined level. 
     
     
         13 . The apparatus of  claim 8 , wherein the first predetermined period of time is approximately thirty minutes and the second predetermined period of time is approximately five minutes. 
     
     
         14 . The apparatus of  claim 8 , wherein the apparatus is disposed in a vending machine. 
     
     
         15 . A vending machine, comprising:
 a product storage area;   a refrigeration system comprising a compressor and an evaporator fan, the refrigeration system configured to cool the product storage area; and   a controller communicatively coupled to the refrigeration system, the controller configured to:   determine a first operating condition of the refrigeration system; and   based on the determination of the first operating condition,
 activate the evaporator fan for a first predetermined period of time, 
 deactivate the evaporator fan for a second predetermined period of time, and 
 repeat the activation and deactivation until a second operating condition is detected. 
   
     
     
         16 . The apparatus of  claim 15 , wherein the first operating condition is a start of a pulldown state or a reload state, and the second operating condition is an end of the pulldown state or the reload state. 
     
     
         17 . The apparatus of  claim 15 , wherein the first operating condition is a discharge gas temperature above a first predetermined level. 
     
     
         18 . The apparatus of  claim 17 , wherein the second operating condition is the discharge gas temperature below a second predetermined level. 
     
     
         19 . The apparatus of  claim 15 , wherein the first operating condition is an ambient temperature outside the product storage area above a predetermined level and the second operating condition is the ambient temperature outside the product storage area at or below the predetermined level. 
     
     
         20 . The apparatus of  claim 15 , wherein the first predetermined period of time is approximately thirty minutes and the second predetermined period of time is approximately five minutes.