Patent ID: 11953240
Assignee: TRANE INTERNATIONAL INC.
Field: Thermal processes and apparatus (Mechanical engineering)
Classification: CPC F | IPC F

Claim 7:
8. A reversible heat pump system for heating and cooling a process fluid of a chiller system, comprising:
a compressor, a first heat exchanger, an expansion device, a second heat exchanger for heat exchange with the process fluid of the chiller system, and a suction line economiser heat exchanger;
wherein the reversible heat pump system is operable in:
a cooling configuration in which there is a sequential flow path for a working fluid through the reversible heat pump system from the compressor through the first heat exchanger, a liquid line pathway, the expansion device, the second heat exchanger and a suction line pathway to the compressor; and
a heating configuration in which there is a sequential flow path for the working fluid from the compressor through the second heat exchanger, a liquid line, the expansion device, the first heat exchanger and a suction line pathway to the compressor;

wherein the second heat exchanger has a process fluid inlet, a process fluid outlet and a process fluid pathway therebetween for heat exchange between the process fluid provided from the chiller system and the working fluid provided to the second heat exchanger;
wherein the reversible heat pump system is configured so that working fluid is provided to the second heat exchanger along the respective sequential flow path:
along a flow direction which opposes flow of the process fluid along the process fluid pathway in the heating configuration in a counterflow arrangement, such that in the heating configuration an inlet for providing working fluid to the second heat exchanger is proximal to the process fluid outlet; and
along a flow direction which corresponds to flow of the process fluid along the process fluid pathway in the cooling configuration in a co-current flow arrangement, such that in the cooling configuration an inlet for providing working fluid to the second heat exchanger is proximal to the process fluid inlet;

wherein in each of the cooling configuration and the heating configuration, the suction line economiser heat exchanger is configured to provide working fluid in the respective liquid line pathway in heat exchange communication with working fluid in the respective suction line pathway; and
a controller configured to:
control the expansion device to maintain a target superheat of the working fluid at a target location along the suction line;
determine a saturation temperature parameter corresponding to a saturation temperature of the working fluid in the suction line; and wherein the control to maintain the target superheat is at least partly based on the saturation temperature parameter.