Refrigeration system

A refrigeration system comprising a compressor operable to supply compressed refrigerant vapour, a condenser to liquify compressed refrigerant vapour from the compressor, a thermostatic expansion valve to vaporize liquified refrigerant from the condenser, an evaporator to cool the surrounding atmosphere by vaporized refrigerant from the thermostatic expansion valve, a superheat sensor to improve control of the thermostatic expansion valve, a compressor discharge line to convey compressed refrigerant vapour from the compressor to the condenser, a return line to convey liquified refrigerant from the condenser to the expansion valve, a suction line including said superheat sensor to convey vaporized refrigerant from the evaporator to the compressor,

• a liquid refrigerant stabilizer in said liquid return line and said suction line operable to convey liquid refrigerant in said return line and vaporized refrigerant in said suction line in heat exchange relationships with each other to cause liquid refrigerant in said return line to be cooled by vaporized refrigerant in said suction line,
• a surge tank, a drain line connected between a portion of the return line upstream of the stabilizer and the surge tank, and a surge line connected between the surge tank and a portion of the return line downstream of the stabilizer,
• a shut-off valve in the drain line between the return line upstream of the stabilizer and the surge tank, and a temperature sensor to sense temperature of refrigerant in the return line between the condenser and the stabilizer and operable to open said shut-off valve when said temperature is below a pre-determined value and close the shut-off valve when the temperature is above a pre-determined value relative to the saturated temperature of the refrigerant in the condenser.