Patent ID: 8302415
Filing Date: 2012-11-06
Classification: F25B

Abstract:
1. A method for controlling a refrigeration system comprising a compressor rack having a variable compressor capacity, at least two refrigeration entities, each having an evaporator being passed by an individually controllable flow of refrigerant, and a pressure control unit, the method comprising the steps of: determining a suction pressure of the refrigeration system, controlling the suction pressure by individually permitting or preventing flow of refrigerant into the evaporator of one or more of the refrigeration entities in response to a control signal from the pressure control unit, so as to maintain the suction pressure within a predetermined suction pressure range, and controlling the compressor capacity so as to match a desired capacity level, based on a signal derived from an average temperature of the at least two refrigeration entities and from a change in refrigeration demand of the refrigeration system determined by the difference between the number of refrigeration entities to which a flow of refrigerant into the evaporator has been individually permitted and the number of refrigeration entities to which a flow of refrigerant into the evaporator has been individually prevented during a specific time period, wherein the step of controlling the suction pressure is performed in such a way that each refrigeration entity maintains a temperature within a predetermined temperature range, and wherein the predetermined temperature range is defined individually for each refrigeration entity.