Refrigeration system

Abstract

A reversible refrigeration system including a compressor arranged to compress gaseous refrigerant, a four-way valve switchable between a heating position in which a payload is heated and a cooling position in which the payload is cooled. A payload heat exchanger is connected to the payload requiring heating or cooling, and a dump heat exchanger, two one-way valves, and two controllable expansion valves as well, wherein the one-way valves each are connected parallel to a corresponding expansion valve, wherein switching of the four-way valve between the heating position and the cooling position controls a flow of pressurized refrigerant to either of the payload heat exchanger or the dump heat exchanger and wherein the heat exchanger which receives the flow of pressurized refrigerant functions as a condenser and the other heat exchanger functions as an evaporator.

1 - 3 . (canceled) 
     
     
         4 . A reversible refrigeration system comprising a compressor arranged to compress gaseous refrigerant, a four-way valve switchable between a heating position in which a payload is heated and a cooling position in which the payload is cooled, a payload heat exchanger connected to the payload requiring heating or cooling, a dump heat exchanger, a first one-way valve, a second one-way valve, a first controllable expansion valve and a second controllable expansion valve,
 wherein the dump heat exchanger comprises first, second, third and fourth large port openings and first and second small port openings,   wherein the payload heat exchanger comprises first, second, third and fourth large port openings and first and second small port openings,   wherein the first controllable expansion valve is arranged between the first small port opening of the payload heat exchanger and the second large port opening of the payload heat exchanger, and the second controllable expansion valve is arranged between the second small port opening of the dump heat exchanger and the second large port opening of the dump heat exchanger, wherein switching of the four-way valve between the heating position and the cooling position controls a flow of pressurized refrigerant to the first large port opening of either of the payload heat exchanger or the dump heat exchanger, wherein the heat exchanger which receives the flow of pressurized refrigerant functions as a condenser and the other heat exchanger functions as an evaporator,   wherein, when the four-way valve is in the heating position and the payload heat exchanger functions as a condenser, the first expansion valve is closed, and a flow of liquid high pressure refrigerant exiting the payload heat exchanger will pass through the first one-way valve, enter the second small port opening of the dump heat exchanger, exit through the first small port opening of the dump heat exchanger, pass through the second expansion valve, enter the second large port opening of the dump heat exchanger, exchange heat with a dump heat exchange liquid in a co-current mode, and then exchange heat with the refrigerant that passes between the second small port opening and the first small port opening of the dump heat exchanger, wherein low pressure gaseous refrigerant exits the dump heat exchanger through the first large port opening thereof.   
     
     
         5 . The reversible refrigeration system of  claim 4 , wherein, when the four-way valve is in the heating position, the heat exchange in the payload heat exchanger is in a counter-current mode. 
     
     
         6 . The reversible refrigeration system of  claim 4 , wherein, when the four-way valve is in the cooling position, the heat exchange in the payload heat exchanger is in a co-current mode, wherein the heat exchange in the dump heat exchanger is in a counter-current mode. 
     
     
         7 . The reversible refrigeration system according to  claim 4 , wherein, when the four-way valve is in the cooling position, the second expansion valve is closed and the second one-way valve is open.