Patent ID: 8590328

Claim:
A refrigeration system with a multi-function heat exchanger for providing cooling to one or more loads within a facility, comprising: a heat exchanger shell having an internal partition separating the shell into a top portion defining a condenser, and a bottom portion defining a subcooler and an evaporator; a discharge gas inlet, a condensate outlet, a condensing fluid inlet and a condensing fluid outlet disposed on the top portion; a liquid subcooler inlet, a subcooled liquid outlet, an evaporator gas inlet, a suction evaporator outlet, a secondary coolant inlet, and a secondary coolant outlet disposed on the bottom portion; an expansion device disposed external of the shell and in fluid communication with the subcooled liquid outlet and the evaporator gas inlet; a primary refrigeration loop having a compressor and configured to circulate a refrigerant from the compressor through a refrigerant flow path including the discharge gas inlet, the condenser, the condensate outlet, the liquid subcooler inlet, the subcooler, the subcooled liquid outlet, the expansion device, the evaporator gas inlet, the evaporator, the suction evaporator outlet, and back to the compressor; a secondary coolant loop configured to circulate a coolant from the loads through a secondary cooling flow path including the secondary coolant inlet, the secondary coolant outlet, and back to the loads, wherein the coolant first subcools the refrigerant and the coolant is then cooled by the refrigerant as the coolant travels along the secondary coolant flow path between the secondary coolant inlet and the secondary coolant outlet; a control system including a control module configured to receive a first signal representative of refrigerant temperature proximate the suction evaporator outlet and a second signal representative of refrigerant pressure proximate the suction evaporator outlet, and to provide a control signal to the expansion device to maintain a superheat temperature of the refrigerant proximate the suction evaporator outlet within a predetermined range; and a condenser cooling loop having an outdoor heat exchanger and configured to circulate a condensing fluid from the outdoor heat exchanger through a condensing flow path including the condensing fluid inlet, the condenser, the condensing fluid outlet, and back to the outdoor heat exchanger.