Intelligent charge compensation in a heat pump system

Abstract

An HVAC system includes a first heat exchange coil with a plurality of coil circuits. For each coil circuit of the plurality of circuits, there is a manifold line fluidly coupling the coil circuit to a compressor. A first controllable valve is positioned in a first manifold line coupling a first coil circuit of the plurality of coil circuits to the compressor. A second controllable valve is located in a conduit fluidly coupling the first coil circuit to a second heat exchange coil. A controller is communicatively coupled to the first and second controllable valves and operates the valves to provide charge compensation in a heating and/or 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;   for each coil circuit of the plurality of circuits, a manifold line fluidly coupling the coil circuit to a compressor of the HVAC system;   a first controllable valve positioned in a first manifold line coupling a first coil circuit of the plurality of coil circuits to the compressor;   a second controllable valve located in a conduit fluidly coupling the first coil circuit to a second heat exchange coil; and   a controller communicatively coupled to the first controllable valve and the second controllable valve, wherein the controller is configured to:
 determine that the HVAC system is operating in a heating mode; 
 determine that charge compensation is needed; 
 after determining that the HVAC system is operating in the heating mode and that charge compensation is needed:
 cause the first controllable valve to be in a closed position for at least a period of time, such that flow of refrigerant from the first coil circuit to the compressor is prevented; and 
 cause the second controllable valve to be in an open position. 
 
   
     
     
         2 . The HVAC system of  claim 1 , wherein the controller is further configured to cause the second controllable valve to close after a predetermined period of time of operating the HVAC system in the heating mode. 
     
     
         3 . The HVAC system of  claim 1 , wherein the controller is further configured to cause the second controllable valve to close after a predetermined volume of refrigerant is stored in the first coil circuit. 
     
     
         4 . 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;   a first controllable valve positioned in a first manifold line coupling a first coil circuit of the plurality of coil circuits to the compressor;   a second controllable valve located in a conduit fluidly coupling the first coil circuit to a second heat exchange coil; and   a controller communicatively coupled to the first controllable valve and the second controllable valve, wherein the controller is configured to:
 determine that the HVAC system is operating in a normal cooling mode; 
 after determining that the HVAC system is operating in the normal cooling mode:
 cause the first controllable valve to be in an open position; and 
 cause the second controllable valve to be in an open position such that flow of refrigerant from the first coil circuit to a second heat exchanger coil is permitted. 
 
   
     
     
         5 . 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;   a first controllable valve positioned in a first manifold line coupling a first coil circuit of the plurality of coil circuits to the compressor;   a second controllable valve located in a conduit fluidly coupling the first coil circuit to a second heat exchange coil; and   a controller communicatively coupled to the first controllable valve and the second controllable valve, wherein the controller is configured to:
 determine that the HVAC system is operating in a low-demand cooling mode or a low-demand heating mode; 
 after determining that the HVAC system is operating in the low-demand cooling mode or the low-demand heating mode:
 cause the first controllable valve to be in a closed position; and 
 cause the second controllable valve to be in a closed position such that flow of refrigerant from the first coil circuit to a second heat exchange coil is prevented. 
 
   
     
     
         6 . A method of operating a heating, ventilation, and air conditioning (HVAC) system, the method comprising:
 determining that the HVAC system is operating in a heating mode;   determining that charge compensation is needed;   after determining that the HVAC system is operating in the heating mode and that charge compensation is needed:
 causing a first controllable valve to be in a closed position for at least a period of time such that flow of refrigerant from the first coil circuit to the compressor is prevented, wherein the first controllable valve is positioned in a first manifold line coupling a first coil circuit of a first heat exchange coil to a compressor; and 
 causing a second controllable valve to be in an open position such that flow of refrigerant from the first coil circuit to a second heat exchanger coil is permitted. 
   
     
     
         7 . The method of  claim 6 , wherein further comprising causing the second controllable valve to close after a predetermined period of time of operating the HVAC system in the heating mode. 
     
     
         8 . The method of  claim 6 , further comprising causing the second controllable valve to close after a predetermined volume of refrigerant is stored in the first coil circuit. 
     
     
         9 . A method of operating a heating, ventilation, and air conditioning (HVAC) system, the method comprising:
 determining that the HVAC system is operating in a normal cooling mode;   after determining that the HVAC system is operating in the normal cooling mode:
 causing a first controllable valve to be in an open position, wherein the first controllable valve is positioned in a first manifold line coupling a first coil circuit of a first heat exchange coil to a compressor; and 
 causing a second controllable valve to be in an open position such that flow of refrigerant from the first coil circuit to a second heat exchanger coil is permitted. 
   
     
     
         10 . A method of operating a heating, ventilation, and air conditioning (HVAC) system, the method comprising:
 determining that the HVAC system is operating in a low-demand cooling mode or a low-demand heating mode;   after determining that the HVAC system is operating in the low-demand cooling mode or the low-demand heating mode:
 causing a first controllable valve to be in a closed position, wherein the first controllable valve is positioned in a first manifold line coupling a first coil circuit of a first heat exchange coil to a compressor; and 
 causing a second controllable valve to be in a closed position such that flow of refrigerant from the first coil circuit to a second heat exchange coil is prevented.