Water heating appliance and method, and inlet dip tube for use in the appliance or method

Abstract

A system for heating water includes a heat exchange assembly having a heat source and a pump that moves water to be heated at a flow rate; a water storage tank with a water port receiving water inlet flow into the interior of the water storage tank and delivering recirculating water out from the interior of the water storage tank; and a conduit assembly including a valve having an inlet that receives water from water supply, an outlet that delivers water to be heated to the heat exchange assembly at the flow rate, and a port that delivers at least a portion of the water inlet flow to the water storage tank when the water supply flow rate exceeds the flow rate, and receives recirculating water from the water storage tank when the flow rate exceeds the water supply flow rate.

What is claimed is: 
     
         1 . A system for heating water comprising:
 a heat exchange assembly configured to heat water, the heat exchange assembly including
 a water inlet for receiving water to be heated, 
 a water outlet for delivering heated water, 
 a heat exchanger interposed between the water inlet of the heat exchange assembly and the water outlet of the heat exchange assembly and having a heat source positioned to transfer heat to the water to be heated, and 
 a pump configured to move the water to be heated from the water inlet of the heat exchange assembly toward the water outlet of the heat exchange assembly at a flow rate; 
   a water storage tank associated with the heat exchange assembly, the water storage tank defining
 an interior, 
 a water port configured for receiving water inlet flow into the interior of the water storage tank at a water inlet flow rate and for delivering recirculating water outlet flow out from the interior of the water storage tank at a recirculating water outlet flow rate, 
 a recirculating water inlet for receiving recirculating water inlet flow into the interior of the water storage tank at a recirculating water inlet flow rate, and 
 a heated water outlet for delivering heated water outlet flow from the interior of the water storage tank at a heated water outlet flow rate; and 
   a conduit assembly directly or indirectly coupled to the water inlet of the heat exchange assembly and the water port of the water storage tank, the conduit assembly comprising a valve having:
 an inlet configured to receive the water supply flow from the water supply when the conduit assembly is coupled to the water supply, 
 an outlet configured to deliver the water to be heated to the water inlet of the heat exchange assembly at the flow rate, and 
 a port configured to deliver at least a portion of the water inlet flow to the water port of the water storage tank when the water supply flow rate exceeds the flow rate, and receive the recirculating water outlet flow from the water port of the water storage tank when the flow rate exceeds the water supply flow rate. 
   
     
     
         2 . The system of  claim 1 , the heat source of the heat exchanger comprising a gas burner. 
     
     
         3 . The system of  claim 1 , the water inlet of the heat exchange assembly being interposed between the pump and the heat exchanger. 
     
     
         4 . The system of  claim 1 , the water storage tank further comprising an inlet dip tube coupled to the water port and extending into the interior of the water storage tank. 
     
     
         5 . The system of  claim 4 , the inlet dip tube having a wall defining a flow passage for at least a portion of the water inlet flow. 
     
     
         6 . The system of  claim 5 , the wall of the inlet dip tube defining plural flow apertures. 
     
     
         7 . The system of  claim 4 , the inlet dip tube having an end opening for at least a portion of the water inlet flow. 
     
     
         8 . The system of  claim 4 , the inlet dip tube having a flow restrictor positioned to restrict or modulate at least a portion of the water inlet flow or at least a portion of the recirculating water outlet flow. 
     
     
         9 . The system of  claim 8 , the flow restrictor comprising a check valve. 
     
     
         10 . The system of  claim 1 , further comprising a recirculating water circuit including the interior and the water port of the water storage tank, the conduit assembly, the water inlet and the water outlet of the heat exchange assembly, and the recirculating water inlet of the water storage tank, such that the recirculating water circuit does not require any additional opening in the water storage tank, other than the water port and the recirculating water inlet, to complete the recirculating water circuit. 
     
     
         11 . The system of  claim 1 , wherein the pump is configured to move the water to be heated from the water inlet of the heat exchange assembly toward the water outlet of the heat exchange assembly at a predetermined flow rate, a selected nominal flow rate, a constant flow rate, a variable flow rate, or a non-variable flow rate. 
     
     
         12 . A method of heating water comprising the steps of:
 activating a pump, in response to at least one of an elapsed time period, a control signal, a sensed temperature, a rate of change of the sensed temperature, or a demand for heated water, to move water to be heated from a water inlet of a heat exchanger assembly toward a water outlet of the heat exchange assembly at a flow rate;   receiving water supply flow from a water supply at a water supply flow rate;   delivering at least a portion of the water inlet flow to a water port of a water storage tank when the water supply flow rate exceeds the flow rate; and   receiving recirculating water outlet flow from the water port of the water storage tank when the flow rate exceeds the water supply flow rate;   wherein the flow rate is maintained substantially constant and the water supply flow rate fluctuates based at least in part on a heated water outlet flow rate of heated water outlet flow from a heated water outlet of the water storage tank.   
     
     
         13 . The method of  claim 12 , further comprising restricting or modulating at least a portion of the water inlet flow into the water storage tank or at least a portion of the recirculating water outlet flow delivered by the water storage tank. 
     
     
         14 . The method of  claim 13 , further comprising restricting or modulating at least a portion of the water inlet flow or at least a portion of the recirculating water outlet flow using a check valve. 
     
     
         15 . The method of  claim 12 , further comprising delivering at least a portion of the water inlet flow to the water storage tank when the water supply flow rate exceeds the flow rate, and receiving recirculating water outlet flow from the water storage tank when the flow rate exceeds the water supply flow rate, without any additional opening in the water storage tank, other than the water port and the recirculating water inlet, to complete a recirculating water circuit. 
     
     
         16 . An inlet dip tube for a water heating appliance, the inlet dip tube comprising:
 a proximal end portion configured to be coupled to a water port when the inlet dip tube is installed in the water heating appliance;   a distal end portion configured to extend into an interior of the water heating appliance when the inlet dip tube is installed in the water heating appliance;   a wall extending from the proximal end portion to the distal end portion, the wall defining a flow passage, plural flow apertures, and an end opening; and   a flow restrictor positioned to restrict or modulate flow of water into the water heating appliance through the inlet dip tube or flow of water from the water heating appliance through the inlet dip tube when the inlet dip tube is installed in the water heating appliance.   
     
     
         17 . The inlet dip tube of  claim 16 , wherein the flow restrictor comprises a check valve. 
     
     
         18 . The inlet dip tube of  claim 17 , the check valve being a swing check valve. 
     
     
         19 . The inlet dip tube of  claim 17 , the check valve having a spring positioned to bias the check valve in a closed position. 
     
     
         20 . The inlet dip tube of  claim 17 , the check valve being positioned adjacent the end opening defined by the wall. 
     
     
         21 . The inlet dip tube of  claim 16 , one or more of the flow apertures being positioned at the distal end portion of the inlet dip tube. 
     
     
         22 . The inlet dip tube of  claim 16 , the flow apertures being sized to permit flow of water into an interior of the inlet dip tube yet restrict the entrance of scale into the interior of the inlet dip tube. 
     
     
         23 . The inlet dip tube of  claim 16 , the dip tube being configured for flow into the water heater appliance and out from the water heater appliance. 
     
     
         24 . The inlet dip tube of  claim 16 , wherein the flow apertures include apertures positioned near the proximal end of the dip tube to facilitate improved stratification characteristics. 
     
     
         25 . The inlet dip tube of  claim 16 , the inlet dip tube providing a flow conduit configured for directing water flow into a heat exchanger, the inlet dip tube having flow apertures configured to trap scale in a reservoir where it can be cleaned out, serviced, and/or blown back out by reverse flow.