WO2016015098A1

WO2016015098A1 - Heating apparatus, system and method

Info

Publication number: WO2016015098A1
Application number: PCT/AU2015/050424
Authority: WO
Inventors: Jin Fu DI
Original assignee: DI, Shi
Priority date: 2014-07-29
Filing date: 2015-07-28
Publication date: 2016-02-04
Also published as: AU2015296894A1; AU2015296894B2

Abstract

An apparatus (5) for heating water, the apparatus (4) including a non-pressurised tank (14) adapted to contain a heat exchange media, a heat pump (12) in fluid communication with the non-pressurised tank (14), a controller (104) in communication with the heat pump (12) and a temperature sensor (102) in communication with controller (104). The tank (14) includes a first conduit (16) in fluid communication with the heat pump (12) so as to carry a refrigerant, and a second conduit (18) arranged to be communicable with an external water source so as to carry water, the first conduit (16) and the second conduit (18) being arranged relative to one another within the tank (14) such that heat from the refrigerant carried by the first conduit (16) is transferable through the heat exchange media to the second conduit (18) so as to allow heating of the water carried by the second conduit (18). The temperature sensor (102) is arranged relative to the heat exchange media to provide temperature information to the controller (104) indicative of the temperature of the heat exchange media, the controller (104) being configurable to receive the temperature information to thereby allow selective operation of the heat pump (12) to maintain the heat exchange media above pre-determined minimum temperature. A water heating system and a method for heating water is also disclosed.

Description

Heating Apparatus, System and Method

Technical Field

[001] The invention relates to a heating apparatus, system and method. More specifically, the invention relates to a heating apparatus, system, and method for heating a fluid such as water.

Background

[002] It is often desirable to heat water. Accordingly, various apparatuses, systems and methods have been devised to heat water. One such way of heating water is a heat pump water system.

[003] Such a heat pump water system utilises a refrigeration circuit having a heat exchanger, an evaporator, a compressor to heat the refrigerant entering the heat exchanger and an expansion valve to cool the refrigerant leaving the heat exchanger. The evaporator includes an electrically powered fan to draw outside air past the cooled refrigerant so as to warm the refrigerant entering the compressor. The heat exchanger unit includes a pressurised tank and a heat exchanger coil passing through the tank. Pressured potable water is contained by and flows through the pressurised tank so as to be heated by the coil. The pressured potable water is then heated and may be consumed by an end user.

[004] A problem with these heat pump systems is that the potable water in the pressurised tank is directly exposed to the heat exchanger coils that contain the refrigerant. Accordingly, if there is a leak in the heat exchanger coil the water may become contaminated with refrigerant fluid.

[005] Another problem with these heat pump systems is that the tank is sealed and pressurised which limits the ability to connect non-pressurised or low-pressure water sources to the tank. [006] Another problem with these type of water systems is that the pressurised tank may become exposed or contain contaminants such as bacteria which grow within the pressurised tanks and contaminate the pressurised water. This may require periodic cleaning or inspection that has associated costs.

[007] The invention disclosed herein seeks to overcome one or more of the above identified problems or at least provide a useful alternative.

Summary

[008] In accordance with a first main aspect there is provided, an apparatus for heating water, the apparatus including a non-pressurised tank adapted to contain a heat exchange media. The apparatus may include a heat pump in fluid communication with the non-pressurised tank and in some examples the apparatus may also a controller in communication with the heat pump and a temperature sensor in communication with controller. The tank may include a first conduit in fluid communication with the heat pump so as to carry a refrigerant, and a second conduit arranged to communicate with an external water source so as to carry water, the first conduit and the second conduit being arranged relative to one another within the tank such that heat from the refrigerant carried by the first conduit is transferable through the heat exchange media to the second conduit so as to allow heating of the water carried by the second conduit. The temperature sensor may be arranged relative to the heat exchange media to provide temperature information to the controller indicative of the temperature of the heat exchange media, the controller being configurable to receive the temperature information to thereby allow selective operation of the heat pump to maintain the heat exchange media above pre-determined minimum temperature.

[009] In an aspect, the temperature sensor is directly contacted with the heat exchange media within the tank.

[0010] In another aspect, the tank includes a vent arranged to communicate the heat exchange media with the external atmosphere so as to be non-pressurised. [001 1] In yet another aspect, the heat exchange media is water.

[0012] In yet another aspect, the heat pump is located above the tank such that a condensate fluid associated with the heat pump is drainable into the tank.

[0013] In yet another aspect, the heat pump is seated directly atop the tank with a condensate fluid associated with the heat pump being selectively gravity fed via a fluid control device into the tank.

[0014] In yet another aspect, the apparatus further includes a flow control device arranged to selectively direct the condensate fluid to the tank, the flow control device being moveable between an open condition, whereby the condensate fluid may pass into the tank, and a closed condition in which the condensate fluid is inhibited from entering the tank.

[0015] In yet another aspect, the flow control device includes a valve which is adapted to be moveable between the open and closed conditions to selectively allow passage of the condensate fluid between heat pump and the tank.

[0016] In yet another aspect, the flow control device includes a measuring component coupled to the valve, the measuring component being arranged to determine the heat exchange media level in the tank so as to move the valve to the open condition when the level of the heat exchange media in the tank is below a pre-determined level, and move the valve to the closed condition when the level of the heat exchange media in the tank is above the predetermined level.

[0017] In yet another aspect, the measuring component is a float arranged to be located at or adjacent to a surface of the heat exchange media within the tank.

[0018] In yet another aspect, the pre-determining minimum temperature is in the range of 40 to 90 degrees centigrade. [0019] In yet another aspect, the pre-determining minimum temperature is about 60 degrees centigrade.

[0020] In yet another aspect, the first and second conduits each include a respective first coil portion and second coil portion.

[0021] In yet another aspect, the first and second coil portions are concentrically arranged with the first coil portion being an inner coil and the second coil portion being an outer coil.

[0022] In yet another aspect, the inner coil and the outer coil are arranged to extend lengthwise between opposing top and bottom ends of the tank.

[0023] In yet another aspect, the tank includes an inner vessel containing a heat exchange material and the inner coil is arranged to at least partial skirt the inner vessel.

[0024] In yet another aspect, the vessel is a sealed elongate tube extending lengthwise of the tank and wherein the inner coil is contacted with and spirals at least partially along the tube.

[0025] In yet another aspect, the heat exchange material is a material having a phase change in the temperature range of about 35 to 50 degrees centigrade.

[0026] In yet another aspect, the heat exchange material is paraffin.

[0027] In yet another aspect, the tank includes a third inlet and a third outlet are arranged to communicate the heat exchange media with a further external heating source.

[0028] In yet another aspect, the heat pump includes a compressor, an expander, and a fan driven evaporator located between compressor and the expander to heat a refrigerant fluid which provides the first fluid that circulates through the first conduit in the tank. [0029] In accordance with a second main aspect there is provided, a water heating system including an apparatus according to any one of the previous claims and a solar heating arrangement, the solar heating arrangement including at least one solar collector and a pump in fluid communication with the heat exchange media within the tank so as to circulate the heat exchange media between the tank and the at least one solar collector.

[0030] In one aspect, wherein the temperature sensor is located at a solar collector outlet so as to measure the temperature of the heat exchange media heated by the at least one solar collector.

[0031] In accordance with a third main aspect there is provided, an apparatus for heating water, the apparatus including a non-pressurised tank adapted to contain a heat exchange fluid, a heat pump in fluid communication with the non-pressurised tank and a flow control device arranged to allow fluid communication between the heat pump and the non-pressurised tank; wherein the tank includes a first conduit in fluid communication with the heat pump so as to carry a refrigerant, and a second conduit in fluid communication with a water source so as to carry water, the first conduit and second conduit being arranged relative to one another within the tank such that heat from the refrigerant fluid carried by first conduit is transferred through the heat exchange fluid to the second conduit so as to allow heating of the water carried by the second conduit, and wherein the flow control device is arranged to selectively direct a condensate fluid associated with the heat pump to the tank, the flow control device being moveable between an open condition, whereby the condensate fluid may pass into the tank, and a closed condition in which the condensate fluid is inhibited from entering the tank.

[0032] In accordance with a fourth main aspect there is provided, system for heating water, the system including a non-pressurised tank adapted to contain a heat exchange fluid, a heat pump in fluid communication with the non-pressurised tank and a solar heating circuit in communication with the non-pressurised tank; wherein the non- pressurised tank includes a first conduit and a second conduit which are each arranged to extend into the tank so as to be at least partially submersed in the heat exchange fluid; wherein the first conduit includes a first inlet and a first outlet connectable with the heat pump such that the first conduit is arranged to carry a first fluid heated by the heat pump, and wherein the second conduit includes a second inlet and a second outlet connectable with a second fluid source such that the second conduit is arranged to carry a second fluid, the first conduit and second conduit being arranged relative to one another such that heat from the first conduit is transferred through the heat exchange fluid to the second conduit so as to allow heating of the second fluid carried by the second conduit, and wherein the tank includes a third inlet and a third outlet arranged to communicate the heat exchange fluid with the solar heating circuit, the solar heating circuit including a solar collector and a pump arranged to circulate the heat exchange fluid between the tank and the solar collector.

[0033] In accordance with a fifth main aspect there is provided, an integral unit for heating water, the integral unit including a tank and a heat pump supported atop the tank, the tank including a tank body having insulated walls adapted to contain a heat exchange fluid, a first heat exchange conduit arranged to communicate with the heat pump so as to carry a refrigerant and a second heat exchange conduit arranged to communicate with an external water source so as to carry water, the first and second heat exchange conduits being arranged within the tank to transfer heat therebetween through the heat exchange fluid such that the water is heatable.

[0034] In accordance with a sixth main aspect there is provided, a method of heating water, the method including the steps of: Providing a non-pressurised tank and a heat pump in fluid communication with the non-pressurised tank, the non-pressurised the tank including a tank body adapted to contain a heat exchange fluid, and first and second conduits that are at least partially immersable in the heat exchange fluid; and Passing a heated refrigerant through the first conduit so as to circulate between the heat pump and the first conduit; and Passing water between an external water source and the second conduit so as to pass through the second conduit, and Positioning the first and second conduits proximate to one another within the heat exchange fluid such that heat is passed form the heated refrigerant within first heat exchange coil the via the heat exchange fluid to the water in the second heat exchange coil thereby heating the water. [0035] In an aspect, the method further includes the steps of: measuring, via a sensor of a control system, heat exchange fluid temperature information indicative of the heat exchange fluid temperature; and Controlling the heat pump, via a controller of the control system, to maintain the heat exchange fluid temperature above a minimum predetermined temperature.

[0036] In another aspect, the method further includes the steps of: measuring, via a sensor associated with the heat exchange fluid, temperature information indicative of the heat exchange fluid temperature; receiving, at a controller operatively associated with the heat pump, the temperature information; determining, at the controller if the heat exchange fluid temperature is less that a predetermined minimum temperature; and activating, the heat pump if the heat exchange fluid temperature is less that a predetermined minimum temperature so as to heat the heat exchange fluid.

[0037] In another aspect, the method further includes the steps of: Locating the heat pump above the tank such that a condensate associated with the heat pump is drainable into the tank.

[0038] In accordance with a seventh main aspect there is provided, an apparatus for connection with a heat pump to heat water, the apparatus including a non-pressurised tank adapted to contain a heat exchange fluid, a first conduit and a second conduit which are each arranged to extend into the tank so as to be at least partially submersed in the heat exchange fluid; wherein the first conduit includes a first inlet and a first outlet connectable with the heat pump such that the first conduit is arranged to carry a first fluid heated by the heat pump, and wherein the second conduit includes a second inlet and a second outlet connectable with a second fluid source such that the second conduit is arranged to carry a second fluid; and wherein the first conduit and second conduit are arranged relative to one another such that heat from the first conduit is transferred through the heat exchange fluid to the second conduit so as to heat the second fluid carried by the second conduit.

[0039] In accordance with a eighth main aspect there is provided, a non-pressurised tank adapted to contain a heat exchange fluid, the tank including: a first conduit and a second conduit which are each arranged to extend within the tank so as to be at least partially submersed in the heat exchange fluid; and an inner vessel containing a heat exchange material at least partially immersed in the heat exchange fluid; wherein the first conduit includes a first inlet and a first outlet connectable with a heat source such that the first conduit is arranged to carry a first fluid heated by the heat source, the first conduit including a first coil portion between the first inlet and first outlet; and wherein the second conduit includes a second inlet and a second outlet connectable with a second fluid source such that the second conduit is arranged to carry a second fluid, the second conduit including a second coil portion between the second inlet and second outlet; and wherein the first coil portion is arranged to at least partially skirt the inner vessel so as to exchange heat therebetween and the second coil portion is arranged concentrically outwardly of the first coil portion such that heat is exchanged with the second coil portion via the heat exchange fluid at least partially surrounding the inner vessel and the first coil portion.

[0040] In accordance with a ninth main aspect there is provided, a non-pressurised tank adapted to contain a heat exchange fluid, the tank including: at least one conduit arranged to extend within the tank so as to be at least partially submersed in the heat exchange fluid, the at least one conduit being formed from a heat conductive material; and an inner vessel containing a phase change material at least partially immersed in the heat exchange fluid, the vessel being formed from a heat conductive material; and wherein the at least one conduit is arranged adjacent to the vessel so as to exchange heat between a fluid carried by the at least one conduit and the phase change material carried by the vessel, and wherein the vessel is arranged to exchange heat between the phase change material and the surrounding heat exchange fluid.

Brief Description of the Figures

[0041] The invention is described, by way of non-limiting example only, by reference to the accompanying figures, in which;

[0042] Figure 1 is a perspective view illustrating a heating apparatus including a tank assembly and a heat pump;

[0043] Figure 2a is a side sectional view illustrating the apparatus; [0044] Figure 2b is an idealised system block diagram of heat exchange components of the apparatus and a control system;

[0045] Figure 3 is an side sectional view illustrating a flow control device of the apparatus;

[0046] Figure 4 is an side sectional view illustrating the apparatus fitted with the flow control device between the heat pump and a tank of the apparatus; and

[0047] Figure 5 is a side sectional view illustrating another example of the apparatus fitted with a central tube containing a heat transfer and storage material;

[0048] Figure 6 is a top sectional view illustrating section A-A as indicated on Figure

5;

[0049] Figure 7 is a side sectional view illustrating another example of a heating system including a control system and a solar thermal collector;

[0050] Figure 8 is system block diagram illustrating the components of the system as shown in Figure 7;

[0051] Figure 9a is a perspective view of a further example of the system including a further heat exchanger; and

[0052] Figure 9b is an idealised system block diagram of heat exchange components of another example of the apparatus and control system.

Detailed Description

[0053] Referring to Figures 1 and 2a, there is shown a heating apparatus 5 including a tank assembly 10 and a heat pump 12. The tank assembly 10 includes a non- pressurised tank 14 adapted to contain a heat exchange or transfer media that may be a fluid, a first conduit 16 and a second conduit 18 which are each arranged to extend into the tank 14 so as to be at least partially submersed in the heat exchange fluid. The heat pump 12 includes a fan 7 and is supported on top of the non-pressurised tank 14. In this example, the a heat exchange or transfer fluid may be water that provides a heated water bath through which the heat exchange occurs between the first conduit 16 and the second conduit 18.

[0054] The first conduit 16 includes a first inlet 20 and a first outlet 22 connectable with the heat pump 12 such that the first conduit 16 is arranged to carry a first fluid heated by the heat pump 12. The first fluid carried by the first conduit 16 may be a refrigerant fluid suitable for use with the heat pump 12, as is further detailed below.

[0055] The second conduit 18 includes a second inlet 24 and a second outlet 26 connectable with an external water source such that the second conduit 18 is arranged to carry a second fluid. In this example, the second fluid is potable or consumable water. The first conduit 16 and second conduit 18 are arranged relative to one another within the tank 14 such that heat from the first conduit 16 is transferable through the heat exchange fluid to the second conduit 18 so as to heat the water carried by the second conduit 18 when the tank assembly 10 is operatively connected with the heat pump 12.

[0056] The tank 14 includes a voluminous tank body 15 which may be cylindrical or rectangular in having side walls 17, a top end 19 and a bottom end 21. The walls 17 of the tank body 15 include insulation and are arranged to support the heat pump 12 atop the top end 19 of the tank body 15. The first and second inlets 20, 24 and the first and second outlets are each located toward the top end 19 of the tank 12. The heat pump 12 may have a casing 51 seated on and arranged to fit with the walls 17 of the tank body 15. Accordingly, the tank 14 and heat pump 12 may be preferably provided as an integral unit 11.

[0057] The top end 19 includes an opening or vent 23 arranged to vent the tank 14 to the external environment. The opening 23 may also provide a condensate fluid inlet 42 of the tank 14. The condensate fluid inlet 42 of the tank 14 may receive condensate fluid from the heat pump 12 as is further described below with reference to Figure 4. The vent 23 may also provides an overflow outlet for the tank 14. [0058] The top end 19 of the tank 14 also includes first apertures 25 which may be fitted with first connectors 27 arranged to allow passage or connection of the first conduit 16 with the heat pump 12. The side walls 17 also include second apertures 29 which may be fitted with second connectors 31 arranged to allow passage or connection of the second conduit 18 with the external water source.

[0059] More specifically, in this example, the second connectors 31 include a water input 33 and a water outlet or return 35, and in use the consumable or potable water passes through the water input 33, through the second conduit 18 and returns heated water to the water outlet 35. The water input and outlet 33, 35 are located on the side walls 17 toward or adjacent to the top end 1 of the tank body 15. The side walls 17 of the tank body 15 also include a heating fluid inlet 13, located at to toward the bottom end 21 of the tank body 15, and a heating fluid outlet 9, located toward or adjacent to the top end 19 of the tank body 15, which may be used to circulate the heating fluid within the tank 14 with a solar system as is further detailed below with reference to Figure 7.

[0060] Turning to the arrangement of the first and second conduits 16, 18 in more detail, the first and second conduits 16, 18 each include respective first and second coiled portions 28, 30, and first and second non-coiled or straight portions 37, 38. The first and second coiled portions 28, 30 are concentrically arranged with the first coil portion 28 being an inner coil 32 and the second coil portion 30 being an outer coil 34.

[0061] The inner coil 32 and the outer coil 34 are arranged to extend lengthwise between opposing top end 19 and bottom end 21 of the tank 14. More specifically, the non-coiled portion 37 of the first conduit 16 extends from the first inlet 20 vertically downwardly into the tank body 15 toward the bottom end 21 of the tank body 15, the first conduit 16 that then spirals upwardly to form the first coil portion 28 internally of the second coil portion 30. The first coil portion 28 terminates short of the second coil portion 30 and then returns to the first non-coiled portion of the first conduit 16 that extends vertically upwardly to the first outlet 22. [0062] The second non-coiled or straight portion 39 of the second conduit 18 extends from the second inlet 24 vertically downwardly into the tank body 15 toward the bottom end 21 of the tank body 15 In this example, the second conduit 18 does not extend as deep into the tank body 15 as the first conduit 16. The second conduit 16 then spirals upwardly to form the second coil portion 30 around or skirting the first coil portion 28. The second coil portion 30 extends past the first coil portion 28 to a location adjacent to a surface level of the heat transfer or exchange fluid, the second conduit 18 then returns to the second straight portion 39 and proceeds to the second outlet 26.

[0063] The first coil portion 28 which carries heated refrigerant fluid is located internally of and at least partially below the second coil portion 30. The second coil portion 30 which carries the water to be heated extends past the first coil portion 28 toward to top end 19 of the tank body 15. Accordingly, the first coiled portion 28 includes a lower section below the second coil portion 30 and the second coil portion 30 includes an upper section above the first coiled portion 28, and each of the first and second coiled portions include a main and intermediate overlapping or adjacent zone 38.

[0064] In this example, the tank 14 may have a volume of about 300 to 500 litres. The first conduit 16 having the inner coil 32 is arranged to have a static capacity of about 7 litres and the second conduit 18 having the outer coil 34 is arranged to have a static capacity of about 7 litres. The first conduit 16 having the inner coil 32, and the second conduit 18 having the outer coil 34 may be formed from metal including stainless steel such as 316 stainless or titanium. Other heat conductive materials may also be used. The flow rate of the refrigerant through the first conduit 16 having the inner coil 32 is determined by the heat pump 12, as is further detailed below. The flow rate of the water to be heated through the second conduit 18 having the outer coil 34 may be about 12 litres per minute for a 300 litre tank. For the 500 litre tank the flow rate may be increased as required.

[0065] Referring additionally to Figure 2b, the apparatus 5 may be configured as a heating system 125 having a control system or arrangement 100 configured to maintain the temperature of the heat exchange media. The control system 100 includes one or more temperature sensors 102 and a control unit 104. In this example, the temperature sensor 102 may be located in the tank 14 so as to directly measure the temperature of the heat transfer media that in this example is a vented static water bath.

[0066] The control unit 104 is operatively communicated with the heat pump 12 to control the heat output from the heat pump 12, specifically the refrigerant temperature, so as to control the temperature of the heat exchange media in the tank at or above a pre-determined temperature. For example, the pre-determined temperature may be about 60 degrees centigrade and when the heat transfer media in the tank 14 is at about 60 degrees the control unit 104 communicates a signal to the heat pump 12 to turn the heat pump off or to a lower heat and/or power setting, and when the temperature of the heat transfer fluid drops below a minimum predetermined temperature of about 60 degrees the control unit 104 communicates another signal to the heat pump 12 to turn the heat pump 12 on or to a higher heat and/or power settings. The control unit 104 may be a computer controller such as a PLC (Programmable Logic Controller) or the like.

[0067] The heat pump 12 may preferably be an air sourced heat pump (ASHP) unit. These types of units are well known and readily commercially available. For a 300 litre tank a 1.25 Horse Power ASHP unit may be used and for a larger 500 litre tank a 2 Horse Power ASHP unit may be used. An ASHP typically includes a heat exchanger coil (also known as a condenser coil) that in this example is the first conduit 16 located within the tank 14 between a compressor 41 and an expander 43, and an evaporator 45 driven by the fan 7 located between the compressor and the expander.

[0068] The evaporator 45 is exposed to the external environment so as to absorb heat from the outside air. The compressor 41 pushes the refrigerant gas through the system compressing it until it is at the desired temperature (typically up to about 45-60 degrees Celcius). The hot refrigerant then passes through the heat exchanger coil, being in this example the first conduit 16, where the heat from the refrigerant is transferred to the heat transfer fluid within the tank 14. The refrigerant then passes back through the expander 43 and into the evaporator 45 to collect further heat from the external environment. During this process the fan driven evaporator 45 generates condensation as the air is cooled when contacting the evaporator. The heat pump 12 may include a condensation reservoir to collect the condensation fluid or condensate. The condensation reservoir may include a drip tray 84 or similar fluid collection structure, as shown below in Figure 5 which collects the condensate and directs the collected condensate fluid into the tank 14, via the inlet 42, to maintain a fluid level in the tank 14.

[0069] Referring now to Figures 3 and 4, the tank assembly 10 may further include a flow control device 40 arranged between a condensate outlet 62 of the drip tray 84 (shown in Figure 5) of the heat pump 12 and the condensate fluid inlet 42 of the tank 14. The flow control device 40 includes conduit body 46 which is arranged to provide an inlet 48, a tank outlet 50 and an condensate overflow outlet 52 The flow control device 40 includes a valve 44 housed by the conduit body 46 which is adapted to be moveable between an open condition, whereby condensate fluid may pass through the tank outlet 50 into the tank 14, and a closed condition, whereby the condensate fluid is directed to the over flow outlet 52.

[0070] The flow control device 40 includes a measuring component or part 54 coupled to the valve 44. The measuring component 54 is arranged to determine the fluid level of the heat transfer fluid in the tank 14 so as to move the valve 44 to the open condition when the level of the heat transfer fluid in the tank 14 is below a predetermined level, and move the valve 44 to the closed condition when the level of the heat transfer fluid in the tank 14 is above the predetermined level. The predetermined level is shown as 'L' on Figure 4.

[0071] In more detail, in this example, the measuring component 54 is a float 56 arranged to be located at or adjacent to a surface of the heat transfer fluid within the tank 14, and the valve 44 is provided in the form of a piston 58 coupled to the float 56. In this example, the conduit body 46 is substantially T-shaped with a straight section extending 62 between the inlet 48 and the outlet 50, and a perpendicular section 64 extending from the straight section 62 to provide the overflow outlet 52. The straight section 64 includes a fluid guide 66 located above a retaining portion 68. In this example, the fluid guide 66 is provide in the form of a v-shaped funnel 70 and the retaining portion 68 is arranged to provide upper and lower travel stops or limits for the head 69 of the piston 58. The upper end of travel stop being provided by an underside of the funnel and the lower end of the travel stop being provided by an intermediate wall 72 located between the funnel 70 and the outlet 50. The intermediate wall 72 and an outlet wall 74 each include apertures 76 to allow the passage of the condensate there through.

[0072] Accordingly, in use, the float 56 maintains the piston 58 in a closed condition when the heat transfer fluid in the tank 14 is above the predetermined level. In the closed condition the head 69 of the piston 58 is abutted against an underside of the funnel 70 which seals or closes the funnel 70 such that any condensation entering the flow control device 40 is directed to the overflow outlet 52. When the heat transfer fluid in the tank 14 is less than the predetermined level, the head 69 of the piston 58 moves downwardly to open the funnel 70. It is noted that the funnel 70 provides or collects a small volume of condensate which assists to urge the piston 58 downwardly and toward the open condition.

[0073] Referring now to Figures 5 and 6, another example of the heating apparatus 5 is provided and like numerals are used to denote like parts. In this example, the apparatus 5 includes an additional sealed vessel 79 provided in the form of a tube 80 arranged lengthwise within the tank 14. More specifically, the tube 80 is cylindrical and extends between the top end 19 of the tank body 15 and the bottom end 21 of the tank body 14. The tube 80 is formed from a heat conductive material, in this example, stainless steel. The tube 80 is adapted to contain a phase change material such as paraffin as is further described below.

[0074] In this example, the inner coil 32 of the first conduit 16 is arranged to skirt a lower portion or half 82 of the tube 80. At the lower portion 82 the inner coil 32 is arranged to contact or abut with the tube 80 to promote heat transfer between the tube 80 and the inner coil 32. More specifically, the non-coiled portion 37 of the first conduit 16 extends from the first inlet 20 vertically downwardly into the tank body 15 to a position intermediate the tube 80. The first conduit 16 spirals downwardly to form the inner coil 32 toward the bottom end 21 of the tank 14 around the bottom portion 82 of the tube 80, and then spirals back to the position intermediate the tube 80. The inner coil 32 then returns to the first non-coiled portion 37 of the first conduit 16 that extends vertically upwardly to the first outlet 22.

[0075] In this example, the outer coil 34 is arranged to substantially span the length of the tube 80 and is outwardly spaced apart from the inner coil 32. More specifically, the second non-coiled portion 39 of the second conduit 18 extends from the second inlet 24 vertically downwardly into the tank body 15 toward the bottom end 21 of the tank body 15 and the tube 80. The second conduit 16 then spirals upwardly to form the outer coil 34 around or skirting the inner coil 32. The outer coil 34 extends upwardly past the inner coil 34 to a location adjacent to a surface level of the heat transfer fluid, the second conduit 18 then returns to the second straight portion 39 and proceeds to the second outlet 26. Accordingly, in this arrangement, the inner and outer coils 32, 34 main overlapping or adjacent zone 38 along the lower portion or half 82 of the tube 80.

[0076] This example of the apparatus 5 operates in a similar way to the example described with reference to Figures 1 to 4. However, in this example, the phase change material contained in the tube 80 provides additional thermal capacity. More specifically, in some examples, the phase change material may be paraffin which has a melting temperature of about 37 to 40 degrees centigrade and a boiling temperature of over 300 degrees centigrade. Accordingly, in operation, the temperature of water within the tank 14 may be, for example, in the range of 50 to 60 degrees centigrade. At this temperature the paraffin is substantially in liquid form. If the tank water temperature then drops to below about 40 degrees centigrade, the paraffin will begin to solidify and release its latent heat into the tank water thereby assisting to maintain the tank water above or at about 37 to 40 degrees centigrade. It is also noted that the inner coil 32 being in direct contact with the tube 80 assist to directly conductively transfer heat to the paraffin to keep the paraffin heated, and the tube 80 presents a relatively large external surface to the surrounding tank water thereby allowing heat transfer from the paraffin, via the tube 80, into the tank water.

[0077] In this example, the heat pump 12 is also shown with a drip tray 84 which is arranged to direct condensate fluid to condensate inlet 62 and the flow control device 40 which is fitted to the tank body 15. The flow control device 40 functions in the same way as that described above in with reference to Figure 3 and 4, and maintains the fluid level within the tank 14 at the pre-determined full level using the condensate fluid. Accordingly, an automatic refill is provided which keeps the vented tank 14 at the pre-determined full level.

[0078] Turning now to Figures 7 and 8, the apparatus 5 may form part of a further heating system 250 that includes a solar collector arrangement 150 and fluid communication with the apparatus 5. The solar collector arrangement 150 is arranged to provide additional heat to and circulate the heat transfer fluid in the tank 14. Advantageously, as the tank 14 is a non-pressurised vented tank, the tank 14 may be optionally fitted connected to a standard solar collector arrangement or system 150 as is further described below.

[0079] The solar thermal collector arrangement 150 includes a water pump 152 and one or more solar collectors 154. When configured for use with a solar collector arrangement 150, the tank body 15 includes the third or solar water inlet 9 and the third or solar outlet 13 that are arranged to communicate the heat transfer fluid with the solar collector arrangement 150. The solar water inlet 9 is provided at the side wall 17 of the tank body 15 at a location adjacent or near to the top end 19, and the solar water outlet 13 is provided at the side wall 17 of the tank body 15 at a location adjacent or near to the bottom end 21. This arrangement of the solar water inlet 9 and the solar water outlet 13 moves or circulates the heat transfer fluid generally vertically downwardly past and generally counter current to the flow direction in first and second coil portions 28, 30.

[0080] The solar thermal collector arrangement 150 further includes a first pipe 159 located between the outlet 13 and the solar collectors 154. The water pump 152 may be fitted to the first pipe 159 to urge the flow to the solar collectors 154. In this example, the temperature sensor or a further temperature sensor 102 is located at a solar collector outlet 155 so as to measure the temperature of the heat transfer fluid heated by the solar collector 154. This provides a direct temperature reference point for the control unit 104 so as to control the heat pump 12 in response the temperature at the solar collector outlet 155. The control unit 104 of the heat pump 12 may be used to directly control the water pump 152. The solar collector 154 is a standard water heating arrangement having a heat absorbing panel 158 and an array or series of pipes 160 which carry the heat transfer fluid along the underside of the heat absorbing panel so as to heat the heat transfer fluid. The heat transfer fluid in this example being water.

[0081] Referring to Figures 9a and 9b, a further example of the system 5 is shown with like numerals denoting like part. In this example, the system 5 further includes an additional heat exchanger 200 in the heat pump refrigeration loop so that the cold energy can be used through the heat exchanger 200 for air conditioning unit 212.

[0082] The heat exchanger 200 includes a heat exchanger body 202 having a water inlet 204 and a water outlet 206 in fluid commendation wit the conditioning unit 212, and a refrigerant inlet and outlet 208, 210 in fluid communication within the refrigerant circuit of the heat pump 12 as is best shown in Figure 9b.

[0083] In this configuration, the control system 100, in particular the control unit 104, may be programmed to have several modes of operation. For example, mode 1 may configured the system 5 as a hot water supply only via the tank 14, mode 2 may configured the system 5 for hot water supply via the tank and space cooling via the air conditioning unit 212, and mode 3 may configure the system 5 for hot water supply via the tank 14 and space heating via the air conditioning unit 212. The air conditioning unit 212 may be an indoor fan unit and a pump may be used to cycle water between the heat exchanger 200 and the indoor fan unit.

[0084] Advantageously, there has been described a heating apparatus and system in which the water being heated, being potable water, is maintained separate from the water within the tank. This has safety advantages whereby the potable water it less likely to become contaminated by the heating system such as by leaking of refrigerant fluid into the potable water. Furthermore, as the potable water is separated from the heat transfer media in the tank, which in this case is water, the tank is not pressurised which allows the tank to be connected to other heating systems such as to solar thermal collectors. [0085] The refrigerant and the potable water are each separately contained in inner and outer coils, respectively, which are arranged to transfer heat from the refrigerant carrying inner coil, to the heat transfer fluid and then to the outer coil carrying the potable water to be heated. The hotter refrigerant being in the inner coil which assists with efficiently transferring heat to the outer coil carrying the colder water to be heated.

[0086] The heating and control of temperature of the heat exchange media allows the control system to selectively operate the heat pump to heat the heat exchange media. The heat exchange media, preferably being water that has a relatively high thermal capacity, thereby allowing the efficient heating of the coil carrying the potable water even when the heat pump is not in active operation.

[0087] The above described heating apparatus and system also have further advantages such as a flow control device arranged to allow condensate from the heat pump to flow into the tank to maintain the fluid level in the tank at a full level. The tank may also be fitted with an inner vessel having a phase change material, in this case being paraffin, which provides a thermal buffer to maintain the heat transfer fluid temperature within the tank. The inner coil carrying the refrigerant is wrapped around the lower half of the vessel to heat the paraffin, and the paraffin in turn heats the vessel which in turn heats the surrounding heat transfer fluid, in this example water, within the tank. The tank water then heating the potable water to be heated within the outer coil.

[0088] Furthermore, the above described heating apparatus and system also may be provided as an integral unit enabling "all in one" type functionality that reduces complexity and installation time, and further examples of the system may also include further heat exchangers that allow the system to be further connected to an air conditioning unit.

[0089] Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

[0090] The reference in this specification to any known matter or any prior publication is not, and should not be taken to be, an acknowledgment or admission or suggestion that the known matter or prior art publication forms part of the common general knowledge in the field to which this specification relates.

[0091] While specific examples of the invention have been described, it will be understood that the invention extends to alternative combinations of the features disclosed or evident from the disclosure provided herein.

[0092] Many and various modifications will be apparent to those skilled in the art without departing from the scope of the invention disclosed or evident from the disclosure provided herein.

Claims

The claims defining the Invention are as follows:

1. An apparatus for heating water, the apparatus including a non-pressurised tank adapted to contain a heat exchange media, a heat pump in fluid communication with the non-pressurised tank, a controller in communication with the heat pump and a temperature sensor in communication with controller;

wherein the tank includes a first conduit in fluid communication with the heat pump so as to carry a refrigerant, and a second conduit arranged to be communicable with an external water source so as to carry water, the first conduit and the second conduit being arranged relative to one another within the tank such that heat from the refrigerant carried by the first conduit is transferable through the heat exchange media to the second conduit so as to allow heating of the water carried by the second conduit, and

wherein the temperature sensor is arranged relative to the heat exchange media to provide temperature information to the controller indicative of the temperature of the heat exchange media, the controller being configurable to receive the temperature information to thereby allow selective operation of the heat pump to maintain the heat exchange media above pre-determined minimum temperature.

2. The apparatus according to claim 1, wherein the temperature sensor is directly contacted with the heat exchange media within the tank.

3. The apparatus according to claim 1 or claim 2, wherein the tank includes a vent arranged to communicate the heat exchange media with the external atmosphere so as to be non-pressurised.

4. The apparatus according to any one of claims 1 to 3, wherein the heat exchange media is water.

5. The apparatus according to claim 4, wherein the heat pump is located above the tank such that a condensate fluid associated with the heat pump is drainable into the tank.

6. The apparatus according to claim 4, wherein the heat pump is seated directly atop the tank with a condensate fluid associated with the heat pump being selectively gravity fed via a fluid control device into the tank.

7. The apparatus according to claim 5, wherein the apparatus further includes a flow control device arranged to selectively direct the condensate fluid to the tank, the flow control device being moveable between an open condition, whereby the condensate fluid may pass into the tank, and a closed condition in which the condensate fluid is inhibited from entering the tank.

8. The system according to claim 7, wherein the flow control device includes a valve which is adapted to be moveable between the open and closed conditions to selectively allow passage of the condensate fluid between heat pump and the tank.

9. The system according to claim 8, wherein the flow control device includes a measuring component coupled to the valve, the measuring component being arranged to determine the heat exchange media level in the tank so as to move the valve to the open condition when the level of the heat exchange media in the tank is below a predetermined level, and move the valve to the closed condition when the level of the heat exchange media in the tank is above the predetermined level.

10. The system according to claim 9, wherein the measuring component is a float arranged to be located at or adjacent to a surface of the heat exchange media within the tank.

11. The system according to any one of the previous claims, wherein the predetermining minimum temperature is in the range of 40 to 85 degrees centigrade.

12. The system according to claim 1 1, wherein the pre-determining minimum temperature is about 60 degrees centigrade.

13. The apparatus according to any one of the previous claims, wherein the first and second conduits each include a respective first coil portion and second coil portion.

14. The apparatus according to claim 13, wherein the first and second coil portions are concentrically arranged with the first coil portion being an inner coil and the second coil portion being an outer coil.

15. The apparatus according to claim 14, wherein the inner coil and the outer coil are arranged to extend lengthwise between opposing top and bottom ends of the tank.

16. The apparatus according to claim 15, wherein the tank includes a first inlet and first outlet between which the first conduit extends, and a second inlet and a second outlet between which the second conduit extends, the first and second inlets and outlets being each located toward the top end of the tank.

17. The apparatus according to any one of claims 13 to 16, wherein the tank includes an inner vessel containing a heat exchange material and the inner coil is arranged to at least partial skirt the inner vessel.

18. The apparatus according to claim 17, wherein the vessel is a sealed elongate tube extending lengthwise of the tank and wherein the inner coil is contacted with and spirals at least partially along the tube.

19. The apparatus according to claim 18, wherein the heat exchange material is a material having a phase change in the temperature range of about 35 to 50 degrees centigrade.

20. The apparatus according to claim 19, wherein the heat exchange material is paraffin.

21. The apparatus according to any one of the previous claims, wherein the tank is arranged to communicate the heat exchange media with a further external heating source.

22. The apparatus according to any one of the previous claims, wherein the heat pump includes a compressor, an expander, and a fan driven evaporator located between compressor and the expander to heat a refrigerant fluid that provides the first fluid that circulates through the first conduit in the tank.

23. A water heating system including an apparatus according to any one of the previous claims and a solar heating arrangement, the solar heating arrangement including at least one solar collector and a pump in fluid communication with the heat exchange media within the tank so as to circulate the heat exchange media between the tank and the at least one solar collector.

24. The system according to claim 23, wherein the temperature sensor is located at a solar collector outlet so as to measure the temperature of the heat exchange media heated by the at least one solar collector.

25. An apparatus for heating water, the apparatus including a non-pressurised tank adapted to contain a heat exchange fluid, a heat pump in fluid communication with the non-pressurised tank and a flow control device arranged to allow fluid communication between the heat pump and the non-pressurised tank;

wherein the tank includes a first conduit in fluid communication with the heat pump so as to carry a refrigerant, and a second conduit in fluid communication with a water source so as to carry water, the first conduit and second conduit being arranged relative to one another within the tank such that heat from the refrigerant fluid carried by first conduit is transferred through the heat exchange fluid to the second conduit so as to allow heating of the water carried by the second conduit, and

wherein the flow control device is arranged to selectively direct a condensate fluid associated with the heat pump to the tank, the flow control device being moveable between an open condition, whereby the condensate fluid may pass into the tank, and a closed condition in which the condensate fluid is inhibited from entering the tank.

26. A system for heating water, the system including a non-pressurised tank adapted to contain a heat exchange fluid, a heat pump in fluid communication with the non-pressurised tank and a solar heating circuit in communication with the non- pressurised tank; wherein the non-pressurised tank includes a first conduit and a second conduit which are each arranged to extend into the tank so as to be at least partially submersed in the heat exchange fluid;

wherein the first conduit includes a first inlet and a first outlet connectable with the heat pump such that the first conduit is arranged to carry a first fluid heated by the heat pump, and wherein the second conduit includes a second inlet and a second outlet connectable with a second fluid source such that the second conduit is arranged to carry a second fluid, the first conduit and second conduit being arranged relative to one another such that heat from the first conduit is transferred through the heat exchange fluid to the second conduit so as to allow heating of the second fluid carried by the second conduit, and

wherein the tank includes a third inlet and a third outlet arranged to communicate the heat exchange fluid with the solar heating circuit, the solar heating circuit including a solar collector and a pump arranged to circulate the heat exchange fluid between the tank and the solar collector.

27. A integral unit for heating water, the integral unit including a tank and a heat pump supported atop the tank, the tank including a tank body having insulated walls adapted to contain a heat exchange fluid, a first heat exchange conduit arranged to communicate with the heat pump so as to carry a refrigerant and a second heat exchange conduit arranged to communicate with an external water source so as to carry water, the first and second heat exchange conduits being arranged within the tank to transfer heat therebetween through the heat exchange fluid such that the water is heatable.

28. A method of heating water, the method including the steps of:

Providing a non-pressurised tank and a heat pump in fluid communication with the non-pressurised tank, the non-pressurised the tank including a tank body adapted to contain a heat exchange fluid, and first and second conduits that are at least partially immersable in the heat exchange fluid; and

Passing a heated refrigerant through the first conduit so as to circulate between the heat pump and the first conduit; and

Passing water between an external water source and the second conduit so as to pass through the second conduit, and Positioning the first and second conduits proximate to one another within the heat exchange fluid such that heat is passed form the heated refrigerant within first heat exchange coil the via the heat exchange fluid to the water in the second heat exchange coil thereby heating the water.

29. The method according to claim 28, further including the steps of:

Measuring, via a sensor of a control system, heat exchange fluid temperature information indicative of the heat exchange fluid temperature;

Controlling the heat pump, via a controller of the control system, to maintain the heat exchange fluid temperature above a minimum predetermined temperature.

30. The method according to claim 28, further including the steps of:

Locating the heat pump above the tank such that a condensate associated with the heat pump is drainable into the tank.