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AssigneeThermo King Corporation
InventorsJames H. Haley, Gillian M. Drake, Doyle G. Herrig
Estimating the term…
In a transport temperature control system having a cooling and heating mode of operation an apparatus and method are provided for enhancing the heating capacity during the heating mode of operation. A second expansion valve is provided to connect the higher pressure liquid line to the refrigerant circuit downstream of the evaporator. When additional refrigerant is needed in the heating circuit to increase heating capacity, especially during low ambient temperature operating conditions, the second expansion valve is caused to open to admit more refrigerant to the system. After passing through the second expansion valve low pressure gas is passed to the compressor, optimizing compressor efficiency such that an increased amount of hot refrigerant gas is delivered to the evaporator for enhanced heating capacity.
In a transport temperature control system having cooling and heating cycles, a first refrigerant circuit which includes a compressor, condenser, receiver, first expansion valve means, and evaporator, a second refrigerant circuit which includes the compressor and evaporator, and mode selector means having cooling and heating output ports selectively connectable to the first and second refrigerant circuits, respectively, the improvement comprising second expansion valve means having its inlet connected between the receiver and an inlet to said first expansion valve means, an outlet connected between the evaporator and the compressor and sensing means for sensing a superheat condition of the refrigerant at a location between the evaporator and the compressor, such that the opening of said second expansion valve means is controlled according to a predetermined level of the superheat condition.
A method of operating a transport temperature control system having a heating cycle, the system comprising a first refrigerant circuit which includes a compressor, condenser, receiver, first expansion valve and evaporator, and a second refrigerant circuit which includes the compressor and evaporator, mode selector means having cooling and heating output ports selectively connectable to the first and second refrigerant circuits, respectively, and a second expansion valve having its inlet connected between the receiver and an inlet to the first expansion valve and an outlet connected between the evaporator and the compressor, said method comprising the step of:
Dependencies are inferred from the claim text.