A cooling system

Abstract

A cooling system 10 comprises a cooling apparatus for a volume to be cooled. The apparatus comprises a compressor 10, a condenser unit 14, an expansion valve 16, an evaporator unit 12, and a central processing unit 60. The system further comprises a first 40 and a second 42 temperature sensor arranged to determine the superheat in the evaporator unit. The processing unit receives information regarding the superheat in the evaporator unit and controls the compressor and / or expansion valve according to the received information. The first and second sensors may monitor respective temperatures of refrigerant at an inlet and outlet of the evaporator. The compressor speed may be adjusted according to the determined superheat. At least one further sensor may measure ambient air temperature 44, 48, product temperature in a cooling space 46, refrigerant liquid line temperature 50, compressor temperature 52, ambient external air temperature or refrigerant suction pressure. An evaporator fan 32 may be controlled. A method of operating the cooling system is disclosed whereby when superheat is above a predetermined temperature the speed of the compressor is reduced / stopped, and the compressor may be restarted after a time delay and / or the superheat is under a predetermined threshold. Figure 1 to accompany abstract