Heat Pump Liquid Heater

Abstract

A heat pump liquid heater for heating a liquid comprising: a heat pump; a liquid tank in heat communication with the heat pump, wherein the liquid tank comprises the liquid; and at least one metal condenser tube immersed into the liquid, wherein the metal condenser tube forms at least one coil. The metal condenser tube has a flattened double-tube configuration and a cross-section defined by concentric ovals such that at least a portion of the concentric ovals is in contact with one another thereby minimizing space between the flattened double-tubes. The heat pump comprises a tube-in-tube heat exchanger and a compressor, wherein the tube-in-tube heat exchanger recovers heat from refrigerant returning from the liquid tank and transfers the recovered heat to refrigerant going to the compressor thereby superheating the refrigerant.

1 - 14 . (canceled) 
   
   
       15 . A heat pump liquid heater for heating a liquid comprising:
 a heat pump;   a liquid tank in heat communication with the heat pump, wherein the liquid tank comprises the liquid;   at least one metal condenser tube immersed into the liquid, wherein the metal condenser tube comprises a refrigerant;   a tube-in-tube heat exchanger in fluid communication with a compressor, wherein the tube-in-tube heat exchanger recovers heat from refrigerant returning from the liquid tank and transfers the recovered heat to refrigerant going to the compressor thereby superheating the refrigerant; and   an adaptor to couple the heat pump to the liquid tank, the adapter configured to support the metal condenser tube.   
   
   
       16 . The heat pump liquid heater of  claim 15 , wherein the metal condenser tube has a flattened double-tube configuration and a cross-section defined by concentric ovals such that at least a portion of the concentric ovals is in contact with one another. 
   
   
       17 . A heat pump liquid heater for heating a liquid in a liquid tank comprising:
 a heat pump;   an adaptor assembly to couple the heat pump to a liquid tank; and   at least one metal condenser tube coupled to the heat pump for immersion in the liquid in the liquid tank, the metal condenser tube having an outgoing leg for a compressed refrigerant to flow from the heat pump to the liquid tank and a return leg for the compressed refrigerant to return to the heat pump, the metal condenser tube configured to transfer heat from the compressed refrigerant to the liquid,   wherein the heat pump comprises a heat exchange chamber to receive the return leg of the metal condenser tube such that the return leg transfers heat from the returning compressed refrigerant to a refrigerant flowing through the heat exchange chamber to generate a superheated refrigerant, and   wherein the adaptor assembly is configured to support the outgoing leg and the return leg of the at least one metal condenser tube.   
   
   
       18 . The heat pump liquid heater of  claim 17 , wherein the metal condenser tube has a flattened double-tube configuration and a cross-section defined by concentric ovals such that at least a portion of the concentric ovals is in contact with one another. 
   
   
       19 . The heat pump liquid heater of  claim 17 , wherein the metal condenser tube is a single continuous coiled tube. 
   
   
       20 . The heat pump liquid heater of  claim 19 , wherein the metal condenser tube has a whisk configuration with multiple smaller diameter condenser tubes emerging from the metal condenser tube, wherein the smaller diameter condenser tubes form coils. 
   
   
       21 . The heat pump liquid beater of  claim 17 , wherein the heat pump comprises a compressor coupled to the heat exchange chamber to output the compressed refrigerant by compressing the superheated refrigerant. 
   
   
       22 . The heat pump liquid heater of  claim 21 , wherein the compressor is powered by a solar energy source. 
   
   
       23 . The heat pump liquid heater of  claim 17 , wherein the adaptor assembly is configured to provide a liquid-tight seal about the outgoing leg and the return leg. 
   
   
       24 . The heat pump liquid heat of  claim 17 , wherein the adaptor assembly is further configured to support a thermostat bulb for immersion in the liquid. 
   
   
       25 . A method of heating a liquid comprising:
 supplying a compressed refrigerant from a heat pump via at least one metal condenser tube;   transferring heat from the compressed refrigerant to the liquid in a liquid tank such that the liquid is heated to a predetermined temperature controlled by a thermostat, and   returning refrigerant to the heat pump via the at least one metal condenser tube; and   transferring heat from the returning refrigerant to superheat a refrigerant flowing in the heat pump; and   compressing the superheated refrigerant in the heat pump to supply the compressed refrigerant.   
   
   
       26 . The method of  claim 25 , wherein the metal condenser tube has a flattened double-tube configuration and a cross-section defined by concentric ovals such that at least a portion of the concentric ovals is contact with one another thereby minimizing space between the flattened double-tubes. 
   
   
       27 . The method of  claim 25 , further comprising powering the heat pump from a solar energy source. 
   
   
       28 . The method of  claim 25 , further comprising coupling the heat pump to the liquid tank via an adaptor assembly, the adaptor assembly configured to support the metal condenser tube. 
   
   
       29 . The method of  claim 28 , wherein the adaptor assembly is further configured to support a temperature sensor coupled to the thermostat, the thermostat bulb to sense temperature of the liquid.