Non-condensable gas purge system for refrigeration circuit

A refrigeration circuit for a chiller system, the refrigeration circuit comprising:

• a loop including a compressor, a condenser, an expansion valve, and an evaporator connected together, the loop containing a low pressure refrigerant;
• and
• a non-condensable gas purge system including
• a purge tank, an interior of the purge tank defining a liquid condensing chamber, the purge tank having a tank inlet, a tank outlet, and a purge outlet;
• a vapor feed line connected to the tank inlet, the vapor feed line being arranged to feed the low pressure refrigerant from the condenser to the liquid condensing chamber;
• a liquid return line connected to the tank outlet, the liquid return line being arranged to return the low pressure refrigerant from the liquid condensing chamber to the evaporator;
• a purge vent line connected to the purge outlet, the purge vent line being arranged to guide non-condensable gas from the liquid condensing chamber to an ambient atmosphere;
• and
• a purge heat exchanger coil disposed inside the liquid condensing chamber of the purge tank, an upper end of the purge heat exchanger coil being fluidly connected to a coil liquid supply line of the refrigerant circuit through an upper portion of the purge tank such that the low pressure refrigerant contained in the loop passes through the purge heat exchanger coil without using a dedicated purge system compressor.