Improvements in systems for heating water

Abstract

A system for heating water in a hot water storage tank, comprising a heater; and means for drawing water onto the heater to be heated from beneath the heater.

What is claimed is: 
     
         1 . A system for heating water in a hot water storage tank, comprising:
 a heater; and   means for drawing water onto the heater to be heated from beneath the heater.   
     
     
         2 . A system according to  claim 1 , wherein the means for drawing water is arranged to prolong the dwell time of water proximate to the heater. 
     
     
         3 . A system according to  claim 1  or  2 , wherein the means for drawing water is arranged to channel the flow of water at least partway along the length of the heater. 
     
     
         4 . A system according to any of  claims 1  to  3 , wherein the means for drawing water comprises a cover arranged to shroud at least part of the heater. 
     
     
         5 . A system according to  claim 4 , wherein the means for drawing water is arranged to feed drawn water into the cover. 
     
     
         6 . A system according to  claim 5 , wherein the means for drawing water is arranged to generate swirl in the drawn water as it is fed into the cover. 
     
     
         7 . A system according to any of  claims 4  to  6 , wherein the cover is arranged to be secured to a wall of the storage tank with the heater substantially enclosed within. 
     
     
         8 . A system according to any of  claims 4  to  7 , wherein the cover is provided with one or more openings through which drawn water can discharge. 
     
     
         9 . A system according to  claim 8 , wherein the one or more openings are spaced from the region of the cover where drawn water is fed into the cover, such that drawn water fed into the cover must pass at least part of the heater before it can discharge through the one or more openings. 
     
     
         10 . A system according to any of  claim 8  or  9 , wherein the one or more openings are configured to control the flow direction of heated water as it discharges out of the cover. 
     
     
         11 . A system according to any of  claims 8  to  10 , wherein the one or more openings are configured to control the flow rate of the heated water in different directions as it discharges out of the cover. 
     
     
         12 . A system according to any of  claims 8  to  11 , wherein the one or more openings are of non-uniform size, shape and/or distribution about the cover, such that a flow of heated water can be directed in a particular direction. 
     
     
         13 . A system according to any of  claims 4  to  12 , wherein the cover is arranged to enclose substantially said at least part of the heater, preferably wherein the cover is arranged to enclose substantially the entire heater, for example wherein the cover is arranged as a canister. 
     
     
         14 . A system according to any preceding claim, wherein the means for drawing water is arranged to draw water from the base of the storage tank. 
     
     
         15 . A system according to any preceding claim, wherein the means for drawing water comprises a fluid conduit that is external of the storage tank. 
     
     
         16 . A system according to  claim 15 , wherein the fluid conduit extends between a fluid outlet and a fluid inlet on the storage tank, and wherein the fluid outlet is lower than the fluid inlet. 
     
     
         17 . A system according to  claim 15  or  16 , further comprising a pump configured to draw fluid along the fluid conduit. 
     
     
         18 . A system according to  claim 17 , wherein the pump is configured to provide a flow rate of between 0.2 litres/min and 15 litres/min. 
     
     
         19 . A system according to  claim 17  or  18 , wherein the pump is controllable such that the flow rate of the drawn water can be controlled. 
     
     
         20 . A system according to any of  claims 17  to  19 , wherein the pump is arranged in-line with the fluid conduit. 
     
     
         21 . A system according to any of  claims 15  to  20 , wherein the means for drawing water further comprises a non-return valve. 
     
     
         22 . A system according to  claim 21 , wherein the non-return valve is configured to open at a threshold pressure of about 0.1 MPa. 
     
     
         23 . A system according to  claim 21  or  22 , wherein the non-return valve is arranged in-line in the fluid conduit. 
     
     
         24 . A system according to  claim 23 , wherein the non-return valve is arranged downstream of the pump. 
     
     
         25 . A system according to any preceding claim, wherein the heater comprises an immersion heater. 
     
     
         26 . A system according to  claim 25 , wherein the immersion heater is arranged to be mounted in an immersion heater port on a wall of the storage tank. 
     
     
         27 . A system according to  claim 25  or  26 , wherein the immersion heater comprises at least one heating element having a power rating of between about 2 kW and about 4 kW, and preferably about 3 kW. 
     
     
         28 . A system according to any preceding claim, wherein the heater a is a heat exchanger disposed inside the storage tank, the heat exchanger preferably being arranged to receive a heated fluid from an external heat source. 
     
     
         29 . A system according to any preceding claim, further arranged such that the water is heated external to the tank. 
     
     
         30 . A system according to any preceding claim, further comprising at least one heat exchanger arranged external to the tank, wherein the heat exchanger is arranged to heat the water before it reaches the heater. 
     
     
         31 . A system according to  claim 30 , wherein the at least one heat exchanger is a plate heat exchanger, for example supplied with heated water from a boiler or heat pump. 
     
     
         32 . A system according to any of  claims 29  to  31 , further comprising a second heat exchanger, wherein at least one of the heat exchangers is supplied with waste heat harvested from a computing application, such as a microprocessor or a central processing unit (CPU). 
     
     
         33 . A system according to  claim 32 , further comprising an electric heater arranged in series with the two heat exchangers, for example wherein the electric heater is an immersion heater disposed inside the tank, preferably wherein at least part of the immersion heater is shrouded. 
     
     
         34 . A system according to any of  claims 14  to  32 , further comprising a diffuser element disposed inside the tank proximate to a fluid inlet of the tank, wherein the diffuser element is arranged to diffuse water as it enters the tank via said inlet. 
     
     
         35 . A system according to  claim 34 , wherein the fluid inlet is arranged to inlet fluid towards the top of the tank, for example via an immersion port. 
     
     
         36 . A system according to any preceding claim, further comprising means for sensing the temperature of the heated water. 
     
     
         37 . A system according to  claim 36 , further comprising means for controlling the heater to heat drawn water to a desired temperature. 
     
     
         38 . A system according to  claim 36  or  37 , further comprising means for controlling the flow rate of water being drawn onto the heater. 
     
     
         39 . A system according to any preceding claim, comprising a thermocline sensor arranged to determine the position of a thermocline in the water stored in the storage tank. 
     
     
         40 . A system according to any preceding claim, further comprising a user interface arranged to receive a user input indicating that a particular draw event is required, determine a time period until a predetermined volume of heated water associated with the indicated draw event is available; and display the determined time period to the user. 
     
     
         41 . A method of heating water in a hot water storage tank, comprising the steps of:
 providing a heater; and   drawing water onto the heater to be heated from beneath the heater.   
     
     
         42 . A method according to  claim 41 , further comprising:
 sensing the temperature of the drawn water heated by the heater; and   controlling the heater to heat the drawn water to a desired temperature.   
     
     
         43 . A method according to  claim 41  or  42 , further comprising:
 sensing the temperature of the drawn water heated by the heater; and 
 controlling the flow rate of the drawn water onto the heater such that the drawn water is heated to a desired temperature by the heater. 
 
     
     
         44 . A method according to any of  claims 41  to  43 , further comprising monitoring the position of the thermocline in the storage tank to determine a volume of heated water that is available at the desired temperature. 
     
     
         45 . A method according to  claim 44 , further comprising controlling the supply of energy to the heater based on the determined volume of available heated water. 
     
     
         46 . A method according to  claim 45 , wherein the supply of heat is controlled based on a difference between the determined volume of available heated water and an expected volume of available heated water. 
     
     
         47 . A method according to any of  claims 41  to  46 , wherein the heater is a heat exchanger. 
     
     
         48 . A method according to any of  claims 41  to  47 , further comprising providing a (further) heat exchanger in series with said heater, wherein the heat exchanger is configured to pre-heat water before it reaches said heater. 
     
     
         49 . A method according to any of  claims 41  to  48 , further comprising:
 receiving a user input indicating that a draw event is required from the hot water storage tank; 
 determining a time delay required to ensure that a predetermined volume of water associated with the draw event is heated to a predetermined temperature; and 
 informing the user of the determined time delay. 
 
     
     
         50 . A method according to any of  claims 41  to  49 , further comprising:
 determining an average volume of heated water taken from the storage tank over a predetermined period; and 
 heating water drawn from beneath the heater until a volume of heated water roughly equal to the determined average volume of heated water used is available. 
 
     
     
         51 . A method according to any of  claims 41  to  50 , further comprising positioning a diffuser element inside the tank, wherein the diffuser element is arranged to intercept the heated water as it enters the tank so as to diffuse the flow of water. 
     
     
         52 . A method of supplying energy to a heater arranged to heat water for storing in a hot water storage tank, comprising:
 monitoring the position of the thermocline in the storage tank;   determining the volume of heated water that is available at a desired temperature based on the position of the thermocline; and   supplying energy to the heater, for example based on a difference between the determined volume of available heated water and an expected volume of available heated water.   
     
     
         53 . A heater assembly for heating water in a hot water storage tank, comprising an immersion heater having a heating element; and means for shrouding at least part of the heating element. 
     
     
         54 . A heater assembly according to  claim 53 , wherein the heater assembly comprises a fluid inlet arranged to provide a fluid path into the water storage tank via the immersion heater. 
     
     
         55 . A heater assembly according to  claim 54 , wherein the fluid inlet is arranged to extend at least partway along the length of the heating element. 
     
     
         56 . A heater assembly according to any of  claims 53  to  55 , wherein the means for shrouding is arranged to have one or more openings through which water contained inside the cover can discharge. 
     
     
         57 . A heater assembly according to  claim 56 , wherein the one or more openings in the means for shrouding are spaced from the end of the fluid inlet. 
     
     
         58 . A heater assembly according to any of  claims 53  to  57 , wherein the means for shrouding is a cover having a length of between about 100 mm and about 300 mm, and preferably about 200 mm. 
     
     
         59 . A heater assembly according to any of  claims 53  to  58 , wherein the means for shrouding is a generally cylindrical cover, preferably having a diameter of about of about 40 mm to about 150 mm, and preferably about 100 mm, for example wherein the means for shrouding is arranged as a canister. 
     
     
         60 . A heater assembly according to  claims 53  to  59 , and configured to be mounted in an immersion port on a water storage tank. 
     
     
         61 . A heater assembly according to any of  claims 53  to  60 , wherein the means for shrouding is arranged to be inserted through an immersion port of a water tank. 
     
     
         62 . A heater assembly according to  claim 61 , wherein the means for shrouding is configured to expand once inserted through the immersion port. 
     
     
         63 . A heater assembly according to any of  claims 53  to  62 , further comprising a temperature sensor arranged to detect the temperature of the drawn water. 
     
     
         64 . An immersion heater for a water storage tank, comprising a fluid inlet arranged to provide a fluid pathway into the water storage tank when mounted therein. 
     
     
         65 . An immersion heater for a hot water storage tank, comprising:
 a plug arranged to be mounted to the hot water storage tank; and   a heating element arranged to extend away from the plug into the hot water storage tank;   wherein the plug is further arranged to provide a fluid inlet to the hot water storage tank.   
     
     
         66 . An immersion heater according to  claim 65 , further comprising a tube that extends at least partially through the fluid inlet in the plug. 
     
     
         67 . A water storage tank, incorporating a system according to any of  claims 1  to  40 . 
     
     
         68 . A water storage tank comprising a heater assembly or immersion heater according to any of  claims 53  to  66 . 
     
     
         69 . A kit of parts, comprising:
 a heater for a hot water storage tank; and   a cover arranged to be placed over the heater, for example when inside the hot water storage tank,   such that the cover at least partially shrouds the heater.   
     
     
         70 . A kit of parts according to  claim 69 , wherein the cover is provided with one or more openings through which water can discharge. 
     
     
         71 . A kit of parts according to  claim 69  or  70 , wherein the cover is arranged to enclose substantially at least part of the heater, for example wherein the openings are provided towards an end of the cover and a substantially opposing end of the cover into which the heater is received is substantially closed. 
     
     
         72 . A kit of parts according to  claims 69  to  71 , wherein the cover is arranged to be secured over the heater to a wall of a hot water storage tank, preferably an internal wall. 
     
     
         73 . A kit of parts according to  claim 72 , wherein the cover is provided with one or more fixing points such that it can be secured to a wall of a water storage tank, preferably using a welding process. 
     
     
         74 . A water storage tank substantially as described herein and illustrated in the accompanying drawings. 
     
     
         75 . A method of heating water substantially as described herein and illustrated in the accompanying drawings. 
     
     
         76 . A system for heating water substantially as described herein and illustrated in the accompanying drawings. 
     
     
         77 . An immersion heater substantially as described herein and illustrated in the accompanying drawings. 
     
     
         78 . A heater assembly substantially as described herein and illustrated in the accompanying drawings.