Heat pump charge compensation for cooling mode operation

Abstract

An HVAC system includes a first heat exchange coil with a plurality of coil circuits, a second heat exchange coil, and an expansion valve. For each coil circuit of the plurality of circuits, there is a conduit coupling the coil circuit to the expansion valve. A check valve is positioned in a first conduit coupling a first coil circuit of the plurality of coil circuits to the expansion valve. The check valve is configured to prevent flow of refrigerant from the first coil circuit to the expansion valve when the HVAC system is operating in a cooling mode.

What is claimed is: 
     
         1 . A heating, ventilation, and air conditioning (HVAC) system configured to regulate a temperature of a space, the HVAC system comprising:
 a first heat exchange coil comprising a plurality of coil circuits;   a second heat exchange coil;   an expansion valve;   for each coil circuit of the plurality of circuits, a conduit coupling the coil circuit to the expansion valve; and   a check valve positioned in a first conduit coupling a first coil circuit of the plurality of coil circuits to the expansion valve, wherein the check valve is configured to prevent flow of refrigerant from the first coil circuit to the expansion valve when the HVAC system is operating in a cooling mode.   
     
     
         2 . The HVAC system of  claim 1 , wherein the check valve is further configured to allow flow of refrigerant from the expansion valve to the first coil circuit when the HVAC system is operating in a heating mode. 
     
     
         3 . The HVAC system of  claim 1 , further comprising, for each coil circuit of the plurality of circuits, a manifold line fluidly coupling the coil circuit to a compressor of the HVAC system. 
     
     
         4 . The HVAC system of  claim 1 , wherein the first heat exchange coil is an outdoor coil, and second heat exchange coil is an indoor coil. 
     
     
         5 . The HVAC system of  claim 1 , further comprising a liquid line fluidly coupling the expansion valve to the second heat exchange coil. 
     
     
         6 . The system of  claim 1 , wherein the first coil circuit is configured to store refrigerant when the HVAC system is operating in the cooling mode. 
     
     
         7 . A heating, ventilation, and air conditioning (HVAC) system configured to regulate a temperature of a space, the HVAC system comprising:
 a first heat exchange coil comprising a plurality of coil circuits;   for each coil circuit of the plurality of circuits, a conduit coupling the coil circuit to an expansion valve; and   a check valve positioned in a first conduit coupling a first coil circuit of the plurality of coil circuits to the expansion valve, wherein the check valve is configured to prevent flow of refrigerant from the first coil circuit to the expansion valve when the HVAC system is operating in a cooling mode; and   a controllable valve located in a manifold line fluidly coupling the first coil circuit to a compressor and configured to be open for at least a period of time when the HVAC system is operating in the cooling mode, such that refrigerant is stored in the first coil circuit.   
     
     
         8 . The HVAC system of  claim 7 , wherein the check valve is further configured to allow flow of refrigerant from the expansion valve to the first coil circuit when the HVAC system is operating in a heating mode. 
     
     
         9 . The HVAC system of  claim 7 , further comprising, for each coil circuit of the plurality of circuits, a manifold line fluidly coupling the coil circuit to a compressor of the HVAC system. 
     
     
         10 . The HVAC system of  claim 7 , further comprising:
 a second heat exchange coil; and   a liquid line fluidly coupling the expansion valve to the second heat exchange coil.   
     
     
         11 . The HVAC system of  claim 10 , wherein the first heat exchange coil is an outdoor coil, and second heat exchange coil is an indoor coil. 
     
     
         12 . The HVAC system of  claim 7 , wherein the controllable valve is further configured to close after a predetermined period of time of operating the HVAC system in the cooling mode. 
     
     
         13 . The HVAC system of  claim 7 , wherein the controllable valve is further configured to close after a predetermined volume of refrigerant is stored in the first coil circuit. 
     
     
         14 . The HVAC system of  claim 7 , wherein the controllable valve is configured to be open when the HVAC system is operating in a heating mode. 
     
     
         15 . A heating, ventilation, and air conditioning (HVAC) system configured to regulate a temperature of a space, the HVAC system comprising:
 a first heat exchange coil comprising a plurality of coil circuits;   for each coil circuit of the plurality of circuits, a manifold line fluidly coupling the coil circuit to a compressor of the HVAC system; and   a check valve positioned in a first manifold line coupling a first coil circuit of the plurality of coil circuits to the compressor, wherein the check valve is configured to prevent flow of refrigerant from the compressor to the first coil circuit when the HVAC system is operating in a cooling mode.   
     
     
         16 . The HVAC system of  claim 15 , wherein the check valve is further configured to allow flow of refrigerant from the first coil circuit to the compressor when the HVAC system is operating in a heating mode. 
     
     
         17 . The HVAC system of  claim 15 , further comprising:
 a second heat exchange coil; and   an expansion valve positioned between the first heat exchange coil and the second heat exchange coil.   
     
     
         18 . The HVAC system of  claim 17 , wherein the first heat exchange coil is an outdoor coil, and second heat exchange coil is an indoor coil. 
     
     
         19 . The HVAC system of  claim 17 , further comprising, for each coil circuit of the plurality of coil circuits, a conduit coupling the coil circuit to the expansion valve. 
     
     
         20 . The HVAC system of  claim 17 , further comprising a liquid line fluidly coupling the expansion valve to the second heat exchange coil.