Heat exchanger

Abstract

A heat exchanger for use in a reversible refrigeration system. The exchanger is divided into a plurality of heat transfer zones containing one or more circuits. Control means are provided to route refrigerant through each zone in a series progression when the heat exchanger is serving as a condenser. The flow geometry is automatically changed when the function of the exchanger is reversed from condenser to evaporator so that refrigerant flows simultaneously through each of the heat transfer zones.

What is claimed is: .[.1. A heat exchanger suitable for use in a heat pump wherein the exchanger acts as a condenser when the flow of refrigerant through the exchanger is in one direction and as an evaporator when the flow of refrigerant through the exchanger is in the opposite direction, the exchanger including 
     
        contains one circuit..]. .[.4.  The heat exchanger of claim 2 wherein the control means is further operable when the flow of refrigerant is in the opposite direction to route refrigerant simultaneously into each of the circuits in each zone..]. .[.5. The heat exchanger of claim 4 further including an expansion device for expanding refrigerant into each of the circuits when the flow of refrigerant is in said opposite direction..]. 
     
     
           A heat exchanger for use in a heat pump wherein the exchanger serves as a condenser when the flow of refrigerant to the exchanger is in one direction and as an evaporator when the flow of refrigerant to the exchanger is in the opposite direction, the exchanger including a coil having a plurality of refrigerant flow circuits passing therethrough,   a first set of said circuits running between a primary header and an intermediate header, the primary header being connected to a compressor line for delivering refrigerant into the exchanger when the refrigerant flow to the exchanger is in one direction,   a second set of said circuits running between said intermediate header and a secondary header, said secondary header being connected to a liquid line for delivering refrigerant to the exchanger when the flow of refrigerant to the exchanger is in the opposite direction and positioned with respect to the first set of said circuits so that when air flows through the heat exchanger the air flow through the first set of said circuits is in parallel with the air flow through the second set of said circuits,   a check valve operatively positioned between the primary and secondary headers, the valve being arranged to prevent refrigerant from moving therethrough when the flow of refrigerant to the exchanger is in said one direction whereby the refrigerant is caused to move in series through the first and then the second set of circuits and to pass refrigerant directly from the secondary header into the primary header when the flow is in the opposite direction,   an expansion device operatively connected to the liquid line and arranged to expand refrigerant into each of the circuits between the intermediate header and the coil, and   a second check valve positioned in the liquid line between the secondary header and the expansion device arranged to operate in opposition to said first check valve to prevent refrigerant from moving into said secondary header from said liquid line when the flow is in the opposite direction whereby the refrigerant moving in the opposite direction is passed simultaneously into each circuit through said expansion device and to   
     
     
        permit passage of refrigerant when the flow is in said one direction. 7. The heat exchanger of claim 6 wherein the number of circuits in the 
     
     
        first set is greater than in the second set. 8. The heat exchanger of claim 7 further including one additional circuit passing through the coil and being interposed between the secondary header and the liquid line, the additional circuit being operatively connected to the expansion device whereby refrigerant flows in series from the second set of circuits through the additional circuit when the flow is in said one direction and simultaneously through the additional circuit and the other circuits when 
     
     
        the flow is in said opposite direction. 9. The heat exchanger of claim 8 wherein the expansion device includes a distributor operatively connected to the liquid line, and   a series of capillary tubes running from the distributor to each of the circuits. .[.10. A method of routing refrigerant through a heat exchanger arranged to serve as a condenser when the flow of refrigerant to the exchanger is in one direction and as an evaporator is in the opposite direction, the steps including   dividing the heat exchanger into a plurality of heat transfer zones arranged so that when air flows through the heat exchanger, the air flows through the zones in parallel paths,   directing refrigerant in a series flow progession through each of the heat transfer zones when the flow to the exchanger is in one direction, and   rerouting the refrigerant through each of the heat transfer zones simultaneously when the flow to the exchanger is in the opposite direction..]. .[.11. The method of claim 10 further including the step of expanding the refrigerant simultaneously into each of the circuits when the flow is in the opposite direction..]. .[.12. The method of claim 10 including the step of arranging the heat transfer zones such that each subsequent zone in the direction of flow in said one direction has less   
     
     
        circuits than the previous zone..]. .[.13.  The method of claim 12 wherein the zones are arranged so that the last zone in the series has a single circuit..]..Iadd. 14. A heat exchanger suitable for use in a heat pump wherein the exchanger acts as a condenser when the flow of refrigerant through the exchanger is in one direction and as an evaporator when the flow of refrigerant through the exchanger is in the opposite direction, the exchanger including one or more refrigerant flow circuits contained within the exchanger,   means to separate the circuits into a plurality of heat transfer zones that are arranged so that when the air flows through the heat exchanger, the air flows through the heat transfer zones in parallel, the number of circuits contained in each zone being different, and   control means operatively associated with the last mentioned means for routing refrigerant in series through the heat transfer zones when the flow of refrigerant through the heat exchanger is one direction and to route the refrigerant simultaneously through each of the zones when the flow of refrigerant is in the opposite direction, said refrigerant being routed through the zones in a descending order relating to the number of circuits in each zone when the flow of refrigerant through the exchanger is in said one direction. .Iaddend..Iadd. 15. The heat exchanger of claim 14 wherein the last zone in the series contains one circuit. .Iaddend..Iadd. 16. The heat exchanger of claim 14 wherein the control means is further operable when the flow of refrigerant is in the opposite direction to route refrigerant simultaneously into each of the circuits in each zone. .Iaddend. .Iadd. 17. The heat exchanger of claim 16 further including an expansion device for expanding refrigerant into each of the circuits when the flow of refrigerant is in said opposite direction. .Iaddend..Iadd. 18. A method of routing refrigerant through the heat exchanger arranged to serve as a condenser when the flow of refrigerant to the exchanger is in one direction and as an evaporator when the flow to the exchanger is in the opposite direction, the steps including   dividing the heat exchanger into a plurality of heat transfers zones arranged so that when air flows through the heat exchanger, the air flows through the zones in parallel paths,   directing refrigerant in series flow progression through each of the heat transfer zones when the flow to the exchanger is in one direction,   rerouting the refrigerant through each of the heat transfer zones simultaneously when the flow to the exchanger is in the opposite direction, and   arranging the heat transfer zones such that each subsequent zone in the direction of flow in said one direction has less circuits than the previous zone. .Iaddend..Iadd. 19. The method as set forth in claim 18 wherein the zones are arranged so that the last zone in the series has a single circuit. .Iaddend.