Low pressure integrated purge

A heating, ventilation, air conditioning and refrigeration system comprising:

• a heat transfer fluid circulation loop configured to circulate a refrigerant therethrough;
• a purge gas outlet in operable communication with the heat transfer fluid circulation loop;
• at least one gas permeable membrane having a first side in operable communication with the purge gas outlet and a second side, said membrane comprising a plurality of pores of a size to allow passage of contaminants through the membrane, while restricting passage of the refrigerant through the membrane, and further restricting passage of a vapor phase corrosion inhibiter through the membrane;
• and
• a purge heat exchanger in operable communication with the second side of the permeable membrane, the purge heat exchanger configured to receive a purge gas from the permeable membrane, the purge heat exchanger located downstream of the permeable membrane such that a flow of purge gas from the purge gas outlet first flows across the permeable through the purge heat exchanger;
• wherein the purge heat exchanger is a component of a thermal purge unit, the thermal purge unit including:
• a purge condenser configured to receive purge gas from the membrane via a purge line;
• and
• a purge condenser coil configured to flow a purge refrigerant therethrough;
• wherein the refrigerant is condensed at the purge condenser via thermal exchange with the purge refrigerant flowing through the purge coil;
• wherein the purge heat exchanger is configured as the purge condenser.

A method of operating a heating, ventilation, air conditioning and refrigeration system, comprising:

• circulating a refrigerant through a heat transfer fluid circulation loop;
• diverting a purge gas comprising contaminants from a purge gas outlet at a condenser of the fluid circulation loop;
• transferring the contaminants across a permeable membrane directly from the condenser, said membrane comprising a plurality of pores of a size to allow passage of contaminants through the membrane, while restricting passage of the refrigerant through the membrane, and further restricting passage of a vapor phase corrosion inhibiter through the membrane;
• and
• urging the purge gas from the permeable membrane to a purge heat exchanger;
• separating refrigerant from the contaminants at the purge heat exchanger;
• and
• directing the refrigerant to an evaporator of the heat transfer fluid circulation loop via a return line;
• wherein the purge heat exchanger is located downstream of the permeable membrane such that the purge gas from the purge gas outlet first flows across the permeable membrane before flowing through the purge heat exchanger.