SUPERHEAT AND SUB-COOLING CONTROL OF REFRIGERATION SYSTEM

摘要

A refrigeration vapor compression system including a compressor, an electronic expansion valve with closed loop feedback into a controller, sensors to measure and monitor the system superheat and sub-cooling, and condenser fans controlling the flow of air through the condensing coils, the refrigeration system is operated in at least one of two functional modes to either give priority control to the level of superheat in the system or maintain a minimum level of sub-cooling in the system.

主权项

1. A refrigerant vapor compression system comprising:
a compressor; first and second heat exchangers fluidly coupled to the compressor; a variable orifice expansion valve located between the first and second heat exchangers; at least one sensor for sensing operating conditions of the system related to a system superheat level and a system subcooling level; a controller operative to receive sensed data from the at least one sensor and, based at least in part thereon, control at least one system component to optimize system performance, the controller configured to:
monitor the system superheat level to determine whether the system superheat level is within a prescribed range of a system superheat setpoint;monitor the system subcooling level to determine whether the system subcooling level is within a prescribed range of a system subcooling setpoint; and,iteratively:
adjust at least one system setting to restore the system subcooling level to within the prescribed range of the system subcooling setpoint while the system superheat level is within its prescribed range;increment the system superheat setpoint when either the system subcooling level or the system superheat level cannot be maintained within their respective prescribed ranges; andadjust at least one system setting to achieve the incremented superheat setpoint.