Refrigeration system anad a method for regulating the refrigeration capacity of such a system

摘要

A refrigeration system whose refrigeration capacity can be regulated continuously in a simple and reliable manner by gradually restricting the flow of refrigerant through an economizer channel to the compressor. The refrigeration system includes a rotary screw compressor, a condenser, a first pressure reducing valve, an economizer, a second pressure reducing valve, and an evaporator connected in sequence by respective channels. An outlet channel connects the evaporator to a low pressure inlet port of the rotary screw compressor to form a closed loop for a refrigerant. An economizer channel selectively connects the economizer to a closed working chamber of the rotary screw compressor. An adjustable valve provided in the economizer channel continuously regulates a mass flow of gaseous refrigerant through the economizer channel. And a sensing device senses a value of at least one parameter of the refrigerant in the closed loop which is indicative of a required refrigeration capacity. The adjustable valve is governed based on the at least one parameter sensed by the sensing device, and the at least one parameter is at least one of a temperature of refrigerant in the outlet channel of the evaporator and a pressure of refrigerant in the outlet channel of the evaporator.