Method and apparatus for refrigeration system control having electronic evaporat or pressure regulators

Abstract

A method and apparatus for refrigeration system control includes a control system operable to modulate a suction pressure of each of the refrigeration circuits by controlling an evaporator pressure regulator respectively associated with each of the refrigeration circuits independently of evaporator refrigerant superheat to meet cooling demand. A sensor assembly provides refrigeration case temperature and evaporator pressure regulator valve position data to the control system to determine cooling demand.

1 . In a refrigeration system having a plurality of refrigeration circuits, a control system operable to modulate a suction pressure of each of said refrigeration circuits by controlling an evaporator pressure regulator respectively associated with said each of said refrigeration circuits independently of evaporator refrigerant superheat to meet cooling demand, and a sensor assembly providing refrigeration case temperature and evaporator pressure regulator valve position data to said control system to determine cooling demand.  
   
   
       2 . The system of  claim 1 , further operable to adaptively control a suction pressure of said refrigeration system until said evaporator pressure regulator is approximately fully open.  
   
   
       3 . The system of  claim 1 , wherein said refrigeration case temperature is an average of multiple temperature measurements.  
   
   
       4 . A method comprising: 
 measuring a refrigeration system operating parameter;    determining a demand for cooling;    controlling electronic variable valves independently of expansion valves to meet the demand for cooling;    positioning at least one of said electronic variable valves at approximately fully open;    positioning another of said electronic variable valves at less than approximately fully open.    
   
   
       5 . The method of  claim 4 , further comprising controlling a compressor.  
   
   
       6 . The method of  claim 4 , wherein said refrigeration system operating parameter is temperature.  
   
   
       7 . The method of  claim 4 , wherein said refrigeration system operating parameter is an average of multiple temperature measurements.  
   
   
       8 . The method of  claim 4 , wherein said refrigeration system operating parameter is pressure.  
   
   
       9 . The method of  claim 4 , wherein said refrigeration system operating parameter is an evaporator pressure regulator valve position.