Control of pull-down in refrigeration systems

摘要

A method for operating a refrigeration system (100) for a container to pull down the temperature of cargo from ambient to a predetermined set-point temperature, and a system employing the method. The method includes operating a compressor (110) at a first power to compress a refrigerant and direct the refrigerant through a condenser (120) and an evaporator (140) of the refrigeration system, initially operating an evaporator fan (150) at a first speed to supply refrigerated supply air from the evaporator to the cargo within the container, sensing the temperature of the supply air, comparing the temperature of the supply air with a predetermined set-point temperature, and increasing the speed of the evaporator fan (150) to a second speed faster than the first when the temperature of the supply air is lower than the predetermined set-point temperature to maintain the temperature of the supply air at the predetermined set-point temperature.