Energy efficient heat pump with flow regulation system

Abstract

An energy efficient heat pump for a heating, ventilation, and air conditioning (HVAC) system includes a compressor system having a plurality of compressors configured to direct a working fluid along a working fluid circuit of the heat pump, a suction conduit configured to direct the working fluid to the compressor system, a first suction conduit portion extending from the suction conduit to a first compressor of the plurality of compressors, a second suction conduit portion extending from the suction conduit to a second compressor of the plurality of compressors, and a control valve disposed along the suction conduit between the first suction conduit portion and the second suction conduit portion.

1 . A heat pump for a heating, ventilation, and air conditioning (HVAC) system, comprising:
 a first compressor configured to direct a working fluid along a working fluid circuit of the heat pump;   a second compressor configured to direct the working fluid along the working fluid circuit;   a valve disposed along a suction conduit portion of the working fluid circuit extending between a first suction inlet of the first compressor and a second suction inlet of the second compressor; and   a controller configured to:
 receive a call for conditioning, wherein the call for conditioning is indicative of a load demand of a thermal load; 
 determine an operating mode of the heat pump based on the load demand; and 
 adjust operation of the first compressor, the second compressor, and the valve to operate the heat pump in the operating mode. 
   
     
     
         2 . The heat pump of  claim 1 , wherein the valve is a first valve and the heat pump comprises:
 a second valve disposed along the working fluid circuit and configured to adjust a flow of the working fluid toward the suction conduit portion; and   a reversing valve disposed along the working fluid circuit and adjustable between a first configuration and a second configuration, wherein the controller is configured to adjust operation of the second valve and the reversing valve based on the operating mode.   
     
     
         3 . The heat pump of  claim 2 , wherein the controller is configured to:
 select a first heating mode as the operating mode in response to a determination that the load demand is a heating demand less than a first threshold heating demand level; and   adjust or retain the reversing valve in the first configuration, operate the first compressor, stay operation of the second compressor, open the first valve, and close the second valve to operate the heat pump in the first heating mode.   
     
     
         4 . The heat pump of  claim 3 , wherein controller is configured to:
 select a second heating mode as the operating mode in response to a determination that the load demand is a heating demand greater than the first threshold heating demand level and less than a second threshold heating demand level, wherein the second threshold heating demand level is greater than the first threshold heating demand level; and   adjust or retain the reversing valve in the first configuration, operate the second compressor, stay operation of the first compressor, open the first valve, and close the second valve to operate the heat pump in the second heating mode.   
     
     
         5 . The heat pump of  claim 4 , wherein the controller is configured to:
 select a third heating mode as the operating mode in response to a determination that the load demand is a heating demand greater than the second threshold heating demand level; and   adjust or retain the reversing valve in the first configuration, operate the first compressor, operate the second compressor, adjust the first valve towards a closed position, and open the second valve to operate the heat pump in the third heating mode.   
     
     
         6 . The heat pump of  claim 5 , comprising an intermediate heat exchanger disposed along the working fluid circuit between the second valve and the suction conduit portion, wherein the intermediate heat exchanger is configured to place a first flow of the working fluid in a heat exchange relationship with a second flow of the working fluid, and the suction conduit portion is configured to direct the second flow of the working fluid from the intermediate heat exchanger and toward the first compressor. 
     
     
         7 . The heat pump of  claim 2 , wherein the controller is configured to:
 select a first cooling mode as the operating mode in response to a determination that the load demand is a cooling demand less than a first threshold cooling demand level; and   adjust or retain the reversing valve in the second configuration, operate the first compressor, stay operation of the second compressor, open the first valve, and close the second valve to operate the heat pump in the first cooling mode.   
     
     
         8 . The heat pump of  claim 7 , wherein the controller is configured to:
 select a second cooling mode as the operating mode in response to a determination that the load demand is a cooling demand greater than the first threshold cooling demand level and less than a second threshold cooling demand level, wherein the second threshold cooling demand level is greater than the first threshold cooling demand level; and   adjust or retain the reversing valve in the second configuration, operate the second compressor, stay operation of the first compressor, open the first valve, and close the second valve to operate the heat pump in the second cooling mode.   
     
     
         9 . The heat pump of  claim 8 , wherein the controller is configured to:
 select a third cooling mode as the operating mode in response to a determination that the load demand is a cooling demand greater than the second threshold cooling demand level; and   adjust or retain the reversing valve in the second configuration, operate the first compressor, operate the second compressor, open the first valve, and close the second valve to operate the heat pump in the third cooling mode.   
     
     
         10 . The heat pump of  claim 9 , wherein the controller is configured to adjust or retain the reversing valve in the second configuration, operate the first compressor, operate the second compressor, adjust the first valve toward a closed position, and open the second valve to operate the heat pump in an efficiency cooling mode. 
     
     
         11 . The heat pump of  claim 10 , comprising an intermediate heat exchanger disposed along the working fluid circuit between the second valve and the suction conduit portion, wherein the intermediate heat exchanger is configured to place a first flow of the working fluid in a heat exchange relationship with a second flow of the working fluid, and the suction conduit portion is configured to direct the second flow of the working fluid from the intermediate heat exchanger and toward the first compressor. 
     
     
         12 . A heat pump for a heating, ventilation, and air conditioning (HVAC) system, comprising:
 a first compressor fluidly coupled to a working fluid circuit;   a second compressor fluidly coupled to the working fluid circuit, wherein the first compressor and the second compressor are arranged in parallel with one another, and a first capacity of the first compressor is less than a second capacity of the second compressor;   a first control valve fluidly coupled to the working fluid circuit and configured to adjust flow of working fluid to the first compressor or the second compressor;   a second control valve fluidly coupled to the working fluid circuit and configured to adjust flow of working fluid to a heat exchanger disposed along the working fluid circuit, wherein the heat exchanger is configured to place a first flow of working fluid in a second heat exchange relationship with a second flow of working fluid; and   a controller communicatively coupled to the first compressor, the second compressor, the first control valve, and the second control valve, wherein the controller is configured to:
 receive a call for conditioning associated with a conditioned space; 
 determine a conditioning demand of the conditioned space based on the call for conditioning; and 
 control operation of the first compressor, the second compressor, the first control valve, and the second control valve in an operating mode based on the conditioning demand. 
   
     
     
         13 . The heat pump of  claim 12 , wherein the controller is configured to:
 determine the conditioning demand is below a first threshold heating demand level; and   operate the first compressor, stay operation of the second compressor, open the first control valve, and close the second control valve to operate the heat pump in a first heating mode based on the conditioning demand being below the first threshold heating demand level.   
     
     
         14 . The heat pump of  claim 13 , wherein the controller is configured to:
 determine the conditioning demand is greater than the first threshold heating demand level and below a second threshold heating demand level; and   operate the second compressor, stay operation of the first compressor, open the first control valve, and close the second control valve to operate the heat pump in a second heating mode based on the conditioning demand being above the first threshold heating demand level and below the second threshold heating demand level.   
     
     
         15 . The heat pump of  claim 14 , wherein the controller is configured to:
 determine the conditioning demand is above the second threshold heating demand level; and   operate the first compressor, operate the second compressor, adjust the first control valve toward a closed position, and open the second control valve to operate the heat pump in a third heating mode based on the conditioning demand being above the second threshold heating demand level.   
     
     
         16 . A controller for a heat pump of a heating, ventilation, and air conditioning (HVAC) system, wherein the controller is configured to:
 receive a call for conditioning associated with a space configured to be conditioned by the HVAC system;   determine a conditioning demand of the space based on the call for conditioning; and   based on a comparison of the conditioning demand to one or more threshold demand levels, adjust operation of:
 a first compressor of the heat pump configured to direct a working fluid along a working fluid circuit of the heat pump, 
 a second compressor of the heat pump configured to direct the working fluid along the working fluid circuit, wherein the first compressor comprises a first capacity and the second compressor comprises a second capacity greater than the first capacity, and 
 a valve disposed along the working fluid circuit between a first suction conduit fluidly coupling the working fluid circuit to a first inlet of the first compressor and a second suction conduit fluidly coupling the working fluid circuit to a second inlet of the second compressor. 
   
     
     
         17 . The controller of  claim 16 , wherein the one or more threshold demand levels comprises a first threshold demand level, and the controller is configured to operate the first compressor, stay operation of the second compressor, and open the valve based on a determination that the conditioning demand is less than the first threshold demand level. 
     
     
         18 . The controller of  claim 17 , wherein the one or more demand levels comprises a second threshold demand level, and the controller is configured to operate the second compressor, stay operation of the first compressor, and open the valve based on a determination that the conditioning demand is greater than the first threshold demand level and less than the second threshold demand level. 
     
     
         19 . The controller of  claim 18 , wherein the controller is configured to operate the first compressor, operate the second compressor, and open the valve based on a determination that the conditioning demand is greater than the second threshold demand level. 
     
     
         20 . The controller of  claim 19 , wherein the valve is a first valve, and the controller is configured to:
 control operation of a second valve disposed along the working fluid circuit to control flow of the working fluid to a heat exchanger disposed along the working fluid circuit, wherein the heat exchanger is configured to place two flows of the working fluid in a heat exchange relationship with one another; and   operate the first compressor, operate the second compressor, adjust the first valve toward a closed position, and open the second valve to operate the heat pump in an efficiency cooling mode.