Dual function water heater and air-conditioning unit

Abstract

A dual function water heater and air-conditioning unit including air-conditioner and water heater subassemblies. In the operational cycle illustrated, the unit heats the water in a geyser and operates an air-conditioner in cooling mode. The geyser heat exchanger acts as a condenser in which the refrigerant transitions from a vapor phase to a liquid phase. The liquid refrigerant is conveyed to an interior unit expansion valve where the liquid refrigerant is flash evaporated and conveyed to the interior unit heat exchanger operating as an evaporator, in which adiabatic cooling of the refrigerant causes extraction of heat from air flowing over the interior unit heat exchanger tubes. The extracted heat is transferred to the refrigerant, causing evaporation of the liquid refrigerant to a gaseous refrigerant, which is directed, from the internal unit heat exchanger to the compressor, for repetition of the cycle.

What is claimed is: 
     
         1 - 11 . (canceled) 
     
     
         12 . A dual function water heater and air-conditioning unit comprising an air-conditioner subassembly and a water heater subassembly interconnected for circulation of a refrigerant within a fluidic circuit configured as a vapour compression refrigeration circuit:
 the air-conditioner subassembly comprising an interior air-conditioning unit configured for installation within a building and an exterior air-conditioning unit configured for installation outside the building;   the interior air-conditioning unit including a first heat exchanger interconnected in-circuit in the refrigeration circuit;   the exterior air-conditioning unit including a second heat exchanger interconnected in-circuit in the refrigeration circuit;   the water heater subassembly including a water tank and a third heat exchanger interconnected in-circuit in the refrigeration circuit and configured for location within the water tank;   the first and second heat exchangers each including outlet tubes and first and second inlet tubes in-circuit in the refrigeration circuit;   the third heat exchanger including inlet and outlet tubes in-circuit in the refrigeration circuit;   the first refrigerant inlet tube of each of the first and second heat exchangers having an expansion valve installed in the refrigeration circuit upstream of the heat exchanger;   the second refrigerant inlet tube of each heat exchanger having no expansion valve;   the refrigeration circuit including a plurality of control valves settable to direct the refrigerant within the refrigeration circuit;   the control valves being settable such that:
 at least one of the first or second heat exchangers is configured to operate as an evaporator, in which setting of the control valves, refrigerant is introduced into the heat exchanger through the expansion valve installed in the first inlet tube of that heat exchanger; 
 at least one of the first or second heat exchangers may be configured to operate as a condenser, in which setting of the control valves, refrigerant is introduced into the heat exchanger through the second inlet tube of that heat exchanger; and 
 the third heat exchanger may be configured to operate as a water heater within the water tank, in which setting of the control valves, the third heat exchanger is configured to operate as a condenser. 
   
     
     
         13 . The dual function water heater and air-conditioning unit of  claim 12 , in which the control valves are preferably settable such that the unit is configured to operate in one of a plurality of modes of operation selected from:
 a first mode of operation—water heating only;   a second mode of operation—water heating and air conditioner cooling;   a third mode of operation—air-conditioning cooling only; and   a fourth mode of operation—air-conditioning heating only.   
     
     
         14 . The dual function water heater and air-conditioning unit of  claim 13 , wherein, in the first mode of operation—water heating only—the control valves are set such that:
 the first heat exchanger is switched out of the refrigeration circuit and no refrigerant is supplied to the first heat exchanger; 
 the third heat exchanger is configured to operate as a condenser, in which setting of the control valves, refrigerant is introduced from the compressor into the third heat exchanger by way of the third heat exchanger inlet tube; and 
 the second heat exchanger is configured to operate as an evaporator, in which setting of the control valves, refrigerant is supplied to the second heat exchanger from the third heat exchanger outlet tube through the first inlet tube of the second heat exchanger, by way of the expansion valve of the second heat exchanger. 
 
     
     
         15 . The dual function water heater and air-conditioning unit of  claim 13 , wherein, in the second mode of operation—water heating and air conditioner cooling—the control valves are set such that;
 the second heat exchanger is switched out of the refrigeration circuit and no refrigerant is supplied to the second heat exchanger; 
 the third heat exchanger is configured to operate as a condenser, in which setting of the control valves, refrigerant is introduced from the compressor into the third heat exchanger by way of the third heat exchanger inlet tube; and 
 the first heat exchanger is configured to operate as an evaporator, in which setting of the control valves, refrigerant is supplied to the first heat exchanger from the third heat exchanger outlet tube through the first inlet tube of the first heat exchanger, by way of the expansion valve of the first heat exchanger. 
 
     
     
         16 . The dual function water heater and air-conditioning unit of  claim 13 , wherein, in the third mode of operation—air-conditioning cooling only—the control valves are set such that:
 the third heat exchanger is switched out of the refrigeration circuit and no refrigerant is supplied to the third heat exchanger; 
 the second heat exchanger is configured to operate as a condenser, in which setting of the control valves, refrigerant is introduced from the compressor into the second heat exchanger by way of the second inlet tube of the second heat exchanger; and 
 the first heat exchanger is configured to operate as an evaporator, in which setting of the control valves, refrigerant is supplied to the first heat exchanger from the second heat exchanger outlet tube through the first inlet tube of the first heat exchanger, by way of the expansion valve of the first heat exchanger. 
 
     
     
         17 . The dual function water heater and air-conditioning unit of  claim 13 , wherein, in the fourth mode of operation—air-conditioning heating only—the control valves are set such that:
 the third heat exchanger is switched out of the refrigeration circuit and no refrigerant is supplied to the third heat exchanger; 
 the first heat exchanger is configured to operate as a condenser, in which setting of the control valves, refrigerant is introduced from the compressor into the first heat exchanger by way of the second inlet tube of the first heat exchanger; and 
 the second heat exchanger is configured to operate as an evaporator, in which setting of the control valves, refrigerant is supplied to the second heat exchanger from the second heat exchanger outlet tube through the first inlet tube of the second heat exchanger, by way of the expansion valve of the second heat exchanger. 
 
     
     
         18 . The dual function water heater and air-conditioning unit of  claim 13 , in which the water tank is the water tank of a water heater/geyser. 
     
     
         19 . The dual function water heater and air-conditioning unit of  claim 13 , including an electric heater element located in the water tank. 
     
     
         20 . The dual function water heater and air-conditioning unit of  claim 12 , in which the third heat exchanger is configured as a direct-heating immersion heating element comprising a finned tube heat exchanger that is installed within the interior of the geyser for direct heat transfer from the heat exchanger to the water within the geyser. 
     
     
         21 . The dual function water heater and air-conditioning unit of  claim 20 , in which the third heat exchanger includes a protector tube secured to the heat exchanger and configured to extend about the outside of the finned tubes of the heat exchanger. 
     
     
         22 . The dual function water heater and air-conditioning unit of  claim 20 , in which the third heat exchanger is configured to conform in shape, size, general form factor and physical connection equipment to current standardised conventional electric water heater elements, such that the water heater heat exchanger is capable of being retrofitted into a conventional electric water heater in place of the conventional electrical element. 
     
     
         23 . The dual function water heater and air-conditioning unit of  claim 22 , in which the third heat exchanger includes a protector tube secured to the heat exchanger to extend about the outside of the finned tubes of the heat exchanger.