Water heating system

Abstract

A modular heat pump water tank is provided. The modular heat pump water tank comprises a tank unit including a tank for containing heated water; a heat pump unit including a heat pump for providing heat to the tank; and a heat exchanger arranged externally to the tank for transferring heat from the heat pump to water from the tank. The tank unit and the heat pump unit are adapted for mounting to one another to form an integrated heat pump water tank.

1 . A modular heat pump water tank comprising:
 a tank unit including a tank for containing heated water;   a heat pump unit including a heat pump for providing heat to the tank; and   a heat exchanger arranged externally to the tank for transferring heat from the heat pump to water from the tank;   
       wherein the tank unit and the heat pump unit are adapted for mounting to one another to form an integrated heat pump water tank. 
     
     
         2 . A modular heat pump water tank according to  claim 1 , wherein the heat pump unit and the tank unit are contained in a common housing or share a common fascia or are fixedly attached to one another. 
     
     
         3 . A modular heat pump water tank according to  claim 1 or 2 , wherein the tank unit and the heat pump unit are reversibly attachable to one another and/or detachable without damage. 
     
     
         4 . A modular heat pump water tank according to  any preceding claim , wherein the heat pump unit and/or the tank unit is adapted for mounting the heat pump unit above the tank unit in use. 
     
     
         5 . A modular heat pump water tank according to  any preceding claim , wherein the heat pump unit and/or the tank unit comprises one or more mounting guides for positioning and orienting the heat pump unit to the tank unit. 
     
     
         6 . A modular heat pump water tank according to  any preceding claim , wherein the heat pump unit and/or the tank unit comprises one or more attachment means for fixing the heat pump unit and the tank unit to one another. 
     
     
         7 . A modular heat pump water tank according to  any preceding claim , wherein the heat pump unit and/or the tank unit comprises one or more module sensors for sensing presence or absence of a heat pump unit at a tank unit. 
     
     
         8 . A modular heat pump water tank according to  any preceding claim , wherein the heat pump unit and/or the tank unit comprises one or more module recognition components for providing characteristics to an associated tank unit or heat pump unit and/or identifying characteristics of an associated tank unit or heat pump unit. 
     
     
         9 . A modular heat pump water tank according to  any preceding claim , wherein the heat pump unit comprises the heat exchanger, preferably wherein the heat exchanger is a plate heat exchanger. 
     
     
         10 . A modular heat pump water tank according to  any preceding claim , further comprising: a conduit providing a flow path from a portion of the tank via the heat exchanger back to the tank; and a pump, preferably a variable speed pump, arranged to pump water through the conduit. 
     
     
         11 . A modular heat pump water tank according to  claim 10 , wherein the conduit provides a flow path external to the tank from a lower portion of the tank via the heat exchanger back to an upper portion of the tank and/or back to the lower portion of the tank. 
     
     
         12 . A modular heat pump water tank according to  claim 10 or 11 , further comprising a valve arrangement arranged in the flow path for selection of a first branch of the conduit or a second branch of the conduit. 
     
     
         13 . A modular heat pump water tank according to any of  claims 10 to 12 , further comprising a non-return valve arranged to prevent water flow from an upper portion of the tank a lower portion of the tank via the conduit. 
     
     
         14 . A tank unit for use in a modular heat pump water tank according to  any preceding claim , wherein the tank unit is adapted for mounting to a heat pump unit to form an integrated heat pump water tank. 
     
     
         15 . A heat pump unit for use in a modular heat pump water tank according to  any preceding claim , wherein the heat pump unit is adapted for mounting to a tank unit to form an integrated heat pump water tank. 
     
     
         16 . An integrated heat pump water tank comprising:
 a heat pump for providing heat;   a tank for containing heated water;   a heat exchanger arranged externally to the tank for transferring heat from the heat pump to water from the tank;   a conduit providing a flow path external to the tank from a portion of the tank via the heat exchanger back to the tank; and   a pump, preferably a variable speed pump, arranged to pump water through the conduit.   
     
     
         17 . An integrated heat pump water tank according to  claim 16 , wherein the heat pump and the tank are contained in a common housing or share a common fascia or are fixedly attached to one another. 
     
     
         18 . An integrated heat pump water tank according to  claim 16 or 17 , wherein the conduit provides a flow path external to the tank from a lower portion of the tank via the heat exchanger back to an upper portion of the tank and/or back to the lower portion of the tank. 
     
     
         19 . An integrated heat pump water tank according to any of  claims 16 to 18 , further comprising a valve arrangement arranged in the flow path for selection of a first branch of the conduit or a second branch of the conduit. 
     
     
         20 . An integrated heat pump water tank according to any of  claims 16 to 19 , further comprising a non-return valve arranged to prevent water flow from an upper portion of the tank a lower portion of the tank via the conduit. 
     
     
         21 . An integrated heat pump water tank according to any of  claims 16 to 20 , wherein the heat pump is arranged above the tank in use. 
     
     
         22 . An integrated heat pump water tank according to any of  claims 16 to 21 , wherein the heat exchanger is a plate heat exchanger. 
     
     
         23 . An integrated heat pump water tank according to any of  claims 16 to 22 , comprising a tank unit including the tank and a heat pump unit including the heat pump, wherein the tank unit and the heat pump unit are modular. 
     
     
         24 . A kit of parts for an integrated heat pump water tank, the kit of parts comprising:
 a tank for containing heated water;   a heat pump for providing heat to the tank; and   a heat exchanger for arrangement external to the tank for transferring heat from the heat pump to water from the tank;   a conduit for providing a flow path external to the tank from a portion of the tank via the heat exchanger back to the tank; and   a pump, preferably a variable speed pump, for pumping water through the conduit;   wherein the tank and the heat pump are reversibly attachable to one another to form an integrated heat pump water tank.   
     
     
         25 . A kit of parts according to  claim 24  adapted to form an integrated heat pump water tank according to any of  claims 16 to 23 . 
     
     
         26 . A heating system comprising: a heat pump for providing heat; a tank for containing heated water; a heat exchanger arranged externally to the tank for transferring heat from the heat pump to water from the tank; a conduit providing a flow path external to the tank from a lower portion of the tank to an upper portion of the tank via the heat exchanger; a pump arranged to pump water through the conduit from the lower portion of the tank to the upper portion of the tank via the heat exchanger; and a non-return valve arranged in the conduit to prevent water flow from the upper portion of the tank the lower portion of the tank via the conduit. 
     
     
         27 . The heating system of  claim 26 , wherein the tank and the heat pump are an integrated heat pump water tank (optionally a cylinder), optionally a modular integrated heat pump water tank. 
     
     
         28 . The heating system of  claim 26 or 27 , wherein the non-return valve is arranged downstream of the pump, and preferably upstream of the heat exchanger. 
     
     
         29 . The heating system of any of  claims 26 to 28 , wherein the non-return valve is a swing valve. 
     
     
         30 . The heating system of any of  claims 26 to 29 , wherein the heat exchanger is a plate heat exchanger. 
     
     
         31 . The heating system of any of  claims 26 to 30 , wherein the heat exchanger is arranged above the tank. 
     
     
         32 . The heating system of any of  claims 26 to 31 , wherein the heat exchanger is arranged at the heat pump. 
     
     
         33 . The heating system of any of  claims 26 to 32 , wherein the heat exchanger is arranged external to a thermal insulation of the tank. 
     
     
         34 . The heating system of any of  claims 26 to 33 , wherein a first branch of the conduit provides a first flow path from the heat exchanger to an upper portion of the tank and a second branch of the conduit provides a second flow path from the heat exchanger to an intermediate portion of the tank, with a valve arrangement for selection of the first or second flow path. 
     
     
         35 . The heating system of any of  claims 26 to 34 , wherein the pump is a variable speed pump. 
     
     
         36 . The heating system of any of  claims 26 to 35 , wherein the tank is for containing pressurised heated water. 
     
     
         37 . The heating system of any of  claims 26 to 36 , wherein the heat pump is arranged above the tank. 
     
     
         38 . The heating system of any of  claims 26 to 37 , wherein the conduit provides a flow path from the bottom of the tank to an upper portion of the tank via the heat exchanger. 
     
     
         39 . The heating system of any of  claims 26 to 38 , wherein the conduit is arranged external to a thermal insulation of the tank. 
     
     
         40 . The heating system of any of  claims 26 to 39 , further comprising one or more sensors for sensing a temperature of the heating system, preferably an array of temperature sensors for sensing temperatures at different locations in the tank. 
     
     
         41 . The heating system of any of  claims 26 to 40 , further comprising a controller configured to control the pump to continue pumping after the heat pump is switched off. 
     
     
         42 . A heating system comprising: a heat pump for providing heat; a tank for containing heated water; a heat exchanger arranged externally to the tank for transferring heat from the heat pump to water from the tank; a conduit providing a flow path external to the tank from a lower portion of the tank to an upper portion of the tank via the heat exchanger; a pump arranged to pump water through the conduit from the lower portion of the tank to the upper portion of the tank via the heat exchanger; and a controller configured to control the pump to continue pumping after the heat pump is switched off. 
     
     
         43 . The heating system of  claim 41 or 42 , wherein the controller is configured to control the pump to continue pumping for a pre-determined period after the heat pump is switched off. 
     
     
         44 . The heating system of  claim 43 , wherein the pre-determined period is at least 3 seconds, preferably at least 5 seconds, further preferably at least 10 seconds, yet further preferably in the range of 10-30 seconds or around 15 seconds. 
     
     
         45 . The heating system of  claim 41 or 42 , wherein the controller is configured to control the pump to continue pumping after the heat pump is switched off until a pre-determined temperature is sensed in water between the heat exchanger and an outlet of the conduit at the upper portion of the tank. 
     
     
         46 . The heating system of any of  claim 42 or claims 43-45  when dependant on  claim 42 , wherein the tank and the heat pump are an integrated heat pump water tank (optionally a cylinder), optionally a modular integrated heat pump water tank. 
     
     
         47 . The heating system of any of  claim 42 or claims 43-45  when dependant on  claim 42 or claim 46 , wherein the heat exchanger is a plate heat exchanger. 
     
     
         48 . The heating system of any of  claim 42 or claims 43-45  when dependant on  claim 42 or claims 46-47 , wherein the heat exchanger and/or the conduit is arranged external to a thermal insulation of the tank. 
     
     
         49 . The heating system of any of  claim 42 or claims 43-45  when dependant on  claim 42 or claims 46-48 , wherein a first branch of the conduit provides a first flow path from the heat exchanger to an upper portion of the tank and a second branch of the conduit provides a second flow path from the heat exchanger to an intermediate portion of the tank, with a valve arrangement for selection of the first or second flow path. 
     
     
         50 . The heating system of any of  claim 42 or claims 43-45  when dependant on  claim 42 or claims 46-49 , further comprising one or more sensors for sensing a temperature of the heating system, preferably an array of temperature sensors for sensing temperatures at different locations in the tank. 
     
     
         51 . A heating system comprising:
 a plate heat exchanger having a first side for connection to a heat pump and a second side for receiving fluid to be heated;   a pump arranged to pump fluid through the second side of the plate heat exchanger;   
       a first flow path arranged to carry water to be heated from a water source to the second side of the plate heat exchanger and to carry heated water away from the second side of the plate heat exchanger; and
 a second flow path arranged to carry descaling fluid to the second side of the plate heat exchanger and to carry descaling fluid away from the second side of the plate heat exchanger, 
 
       wherein the first flow path and the second flow path include the pump. 
     
     
         52 . The heating system of  claim 51 , wherein the second flow path comprises a descaling fluid reservoir. 
     
     
         53 . The heating system of  claim 52 , wherein the second flow path is arranged to carry descaling fluid from the descaling fluid reservoir to the plate heat exchanger and away from the plate heat exchanger. 
     
     
         54 . The heating system of any of  claims 51-53 , wherein the second flow path is a loop. 
     
     
         55 . The heating system of any of  claims 51-54 , wherein the first flow path is arranged to carry water to be heated from a vessel and return heated water to the vessel. 
     
     
         56 . The heating system of  claim 55 , wherein the first flow path comprises a first return pipe for returning heated water to the vessel at a first height and a second return pipe for returning heated water the vessel at a second height. 
     
     
         57 . The heating system of  claim 56 , wherein the first return pipe includes the pump, and the second return pipe includes a further pump. 
     
     
         58 . The heating system of any of  claims 51-57  comprising:
 a first three port junction arranged upstream of the pump and the plate heat exchanger to receive fluid from the first flow path at a first junction port and from the second flow path at a second junction port and to direct fluid to the pump and plate heat exchanger from a third junction port; and 
 a second three port junction arranged downstream of the pump and the plate heat exchanger to receive fluid from the plate heat exchanger at a first junction port and to direct fluid onward to the first flow path from a second junction port and to the second flow path from a third junction port. 
 
     
     
         59 . The heating system of any of  claims 51-58 , further comprising a valve arrangement for isolating the second flow path from the first flow path. 
     
     
         60 . The heating system of  claim 59 , wherein the valve arrangement comprises manually actuatable valves. 
     
     
         61 . The heating system of  claim 59 or claim 60 , wherein the valve arrangement comprises electronically actuatable valves. 
     
     
         62 . The heating system of any of  claims 59-61 , wherein the valve arrangement comprises:
 a first three port valve arranged upstream of the pump and the plate heat exchanger; and   a second three port valve arranged downstream of the pump and the plate heat exchanger.   
     
     
         63 . The heating system of any of  claims 51-62 , wherein the pump is a variable speed pump. 
     
     
         64 . The heating system of any of  claims 51-63 , further comprising:
 one or more sensors for sensing one or more of:   a temperature of the heating system, preferably a temperature of water in a water vessel;   a flow rate of the heating system, preferably a flow rate of water through the plate heat exchanger;   a heat flow of the heating system, preferably a heat flow from the first side of the plate heat exchanger to the second side of the plate heat exchanger; and   a heat transfer rate of the heating system, preferably a heat transfer rate from the first side of the plate heat exchanger to the second side of the plate heat exchanger.   
     
     
         65 . The heating system of any of  claims 51-64 , further comprising:
 a controller for controlling the heating system.   
     
     
         66 . The heating system of  claim 65  when dependent on  claim 59  wherein the controller is configured to control the valve arrangement. 
     
     
         67 . The heating system of  claim 65 or claim 66  wherein the controller is configured to determine a heat transfer rate of the heating system. 
     
     
         68 . The heating system of any of  claims 65-67  wherein the controller is configured to determine a scale condition of the heating system. 
     
     
         69 . The heating system of any of  claims 65-68  wherein the controller is configured to generate an alert related to a scale condition of the heating system. 
     
     
         70 . The heating system of any of  claims 65-69  wherein the controller is configured to control the heating system according to a descaling programme. 
     
     
         71 . The heating system of  claim 70  wherein the descaling programme comprises one or more of:
 a descaling schedule; 
 a pump operating condition; 
 a heat pump operating condition; and 
 a valve arrangement configuration. 
 
     
     
         72 . The heating system of any of  claims 51-71 , wherein the second flow path and/or the descaling fluid reservoir are retrofittable and/or detachably attachable to the heating system. 
     
     
         73 . A method of descaling a heating system, the method comprising:
 forming a fluid circuit to connect a plate heat exchanger and a pump to a water source and a descaling fluid reservoir;   controlling the fluid circuit to isolate the water source from the descaling fluid reservoir; and   controlling the pump to pump descaling fluid from the descaling fluid reservoir through the plate heat exchanger.   
     
     
         74 . The method of  claim 73 , further comprising controlling a heat pump to heat the descaling fluid via the plate heat exchanger, preferably to between 50° C. and 70° C. 
     
     
         75 . The method of  claim 73 or claim 74  wherein descaling fluid is pumped through the plate heat exchanger for between 20 minutes and one hour.