Patent ID: 8424328
Filing Date: 2013-04-23
Classification: F25B

Abstract:
1. A refrigerant system comprising: a compressor, a condenser downstream of said compressor, an expansion device downstream of said condenser and an evaporator downstream of said expansion device; a suction pulse width modulation valve positioned between said evaporator and said compressor; a control for selectively operating said suction pulse width modulation valve to deliver refrigerant to said compressor, said control being operable to utilize a pulse width modulation signal to operate the suction pulse width modulation valve, and a duty cycle of said pulse width modulation signal being controlled to control fluctuations in a sensed system pressure; and an upper limit and a lower limit are set for said system pressure, and a control monitors said system pressure to ensure it is maintained within said upper and lower limits. and said control adjusting said duty cycle of said suction pulse width modulation valve to ensure said system pressure is maintained between said upper and lower limits.