Control for refrigeration system centrifugal compressor

Abstract

Abstract A REFRIGERATION SYSTEM IS PROVIDED WITH A CENTRIFUGAL REFRIGERANT GAS COMPRSSOR HAVING MOVABLE CAPACITY CONTROL MEANS IN ITS INLET AND A FLUID PRESSURE RESPONSIVE PISTON IS MOVABLE TO MOVE THE CAPACITY CONTROL MEANS ACCORDINGLY. FIRST AND SECOND SOLENOID OPERATED FLUID VALVES ARE ARRANGED TO BE NORMALLY DEENERGIZED IN A SYSTEM TO SUPPLY FLUID PRESSURE EQUALLY TO BOTH SIDES OF THE PISTION AND MAINTAIN THE CAPACITY CONTROL IMMOVABLE AT A PARTICULAR CAPACITY POSITION. WHEN A RESPECIVE ONE OF THE VALVES IS ENERGIZED, THE PISTION WILL BE MOVED IN A RESPECTIVE DIRECTION TO CHANGE THE POSITION OF THE CAPACITY CONTROL AND INCREASE OR LOWER THE CAPACITY CONTROL, ACCORDINGLY. A REFRIGERATION SYSTEM CONDITION SENSING CONTROL RESPONDS TO PROVIDE A RESPECTIVE ELECTRIC ENERGIZING SIGNAL TO THE RESPECTIVE VALVE SOLENOID IN THE FORM OF AN INTERMITTENT SIGNAL INCREASING IN FREQUENCY AND/OR DUTY CYCLY TO A CONTINUOUS SIGNAL AS THE SENSED CONDITION LOWERS OR RISES FROM A PRESET CONDITION, RESPECTIVELY, THUS INCREASING CAPACITY CONTROL SENSITIVITY WITHOUT INSTABILITY ABOUT THE PRESET CONDITION.

Inventors

• 👤 Douglas K Richardson

Bibliographic Details