AU2011100896A4 - A heat exchanger - Google Patents

Abstract

There is disclosed a heat exchanger. The heat exchanger comprises a container adapted to house a primary fluid; two or more pipes located within the container and each adapted to convey a secondary fluid and facilitate heat transfer between the primary fluid and the secondary fluid; and four or more side ports located at a side of the container, wherein at least one of the four or more side ports is adapted to allow the primary fluid to be supplied to the container at a heated state and at least one of the four or more side ports is adapted to allow the primary fluid at a cooled state to be removed from the container, and wherein at least one of the four or more side ports is adapted to allow the secondary fluid at a heated state to be supplied to a first of the two or more pipes and at least one of the four or more side ports is adapted to allow the secondary fluid at a cooled state to be removed from the first of the one or more pipes. 40e 40d 30c 40c 40b 30b 40b 30a 40a Fig. 2

Description

5 AUSTRALIA Patents Act 1990 10 COMPLETE SPECIFICATION 15 INNOVATION PATENT A HEAT EXCHANGER 20 The following statement is a full description of this invention, including the best method of performing it known to us: 1 Field of the Invention The present invention relates to a heat exchanger. The invention has been developed primarily for use in water heating and will be described hereinafter with reference to this application. However, it will be appreciated that the 5 invention is not limited to this particular field of use. Background of the Invention Heated water is an important utility in both domestic and commercial settings that can be used for activities such as cooking, cleaning, bathing, pool heating and space heating (hydronic heating). 10 Typically, in a water heating system, an energy source is utilised to generate heat. The most common energy sources being fossil fuels such as natural gas, liquid petroleum gas (LPG) and oil. Increasingly, however, renewable energy such as solar or geothermal is being used to provide clean and sustainable energy sources. Furthermore, a heat exchanger is used to transfer the heat generated by the energy source to the water. Most heat exchangers have a 15 container for storing the heated water in an insulated environment such that the heated water can be provided at high flow rates. Access to within the container to provide water and heat and to extract the heated water is generally only possible via ports located at the top of the container. It is to be understood that, if any prior art information is referred to herein, such reference 20 does not constitute an admission that the information forms part of the common general knowledge in the art, in Australia or any other country. 2 Summary of the Invention The present invention seeks to provide a heat exchanger which will overcome or substantially ameliorate at least some of the deficiencies of the prior art, or to at least provide an alternative. 5 According to one aspect, there is provided a heat exchanger, comprising: a container adapted to house a primary fluid; two or more pipes located within the container and each adapted to convey a secondary fluid and facilitate heat transfer between the primary fluid and the secondary fluid; and 10 four or more side ports located at a side of the container, wherein at least one of the four or more side ports is adapted to allow the primary fluid to be supplied to the container at a heated state and at least one of the four or more side ports is adapted to allow the primary fluid at a cooled state to be removed from the container, and wherein at least one of the four or more side ports is adapted to allow the 15 secondary fluid at a heated state to be supplied to a first of the two or more pipes and at least one of the four or more side ports is adapted to allow the secondary fluid at a cooled state to be removed from the first of the one or more pipes. Advantageously, the four or more side ports are located at the side of the container such that the four or more side ports are more easily accessible. Furthermore, due to the location of 20 the four or more side ports, the four or more side ports is able to be located in close proximity to the two or more pipes. Advantageously, the secondary fluid at a heated state is able to transfer heat to the primary fluid at a cooled state. Preferably, the container is not pressurised. 3 Advantageously, the container is able to be opened with relative ease to provide access therein such that the container can be modified or maintained. Preferably, an internal volume of the container is generally cylindrical in shape. Advantageously, the cylindrical shape of the internal volume allows for better thermal 5 distribution. Therefore, the primary fluid housed in the container can be efficiently heated. Preferably, at least a portion of each of the one or more pipes is configured in a helix. Advantageously, the one or more pipes are able to be compact and yet have longer lengths. Therefore, the surface areas of the one or more pipes are increased to promote heat transfer between the primary and secondary fluids. 10 Preferably, the heat exchanger further comprises two or more top ports located at a top of the container, wherein at least one of the two or more top ports is adapted to allow the secondary fluid at a cooled state to be supplied to a second of the two or more pipes and at least one of the two or more top ports is adapted to allow the secondary fluid at a heated state to be removed from the second of the two or more pipes. 15 Advantageously, the primary fluid at a heated state is able to transfer heat to the secondary fluid at a cooled state. Other aspects of the invention are also disclosed. Brief Description of the Drawings Notwithstanding any other forms which may fall within the scope of the present invention, a 20 preferred embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Fig. 1 is a side view of a heat exchanger in accordance with a preferred embodiment of the present invention; and Fig. 2 is a partial cross sectional side view of the heat exchanger of Fig. 1. 4 Detailed Description of Specific Embodiments It should be noted in the following description that like or the same reference numerals in different embodiments denote the same or similar features. According to a preferred embodiment of the present invention, there is provided a heat 5 exchanger 10 as shown in Figs. 1 and 2. The heat exchanger 10 comprises a container 20, four pipes 30a, 30b, 30c, 30d and five side ports 40a, 40b, 40c, 40d, 40e. Although it is show in Figs. 1 and 2 that the heat exchanger 10 comprises four pipes 30a, 30b, 30c, 30d and five side ports 40a, 40b, 40c, 40d, 40e, it will be appreciated that the heat exchanger 10 may comprise one or more pipes and one or more ports. 10 The container 20 has an internal volume 50 adapted to house a primary fluid. In this embodiment, the primary fluid is water but, in other embodiments, the primary fluid may be any other thermal conductive fluid such as synthetic oil or molten salt. The container 20 is cylindrical in shape and has a top end 60 and a bottom end 70. The top end 60 is removable to provide access to the internal volume 50 for maintenance or modification. In this 15 embodiment, the container 20 is not pressurized such that the top end 60 can removed with relative ease. The heat exchanger 10 further comprises six top ports (not shown) located at the top end 60 that are adapted to provide access to the internal volume 50. The bottom end 70 is planar and adapted to support the container 20 in an upright position in use. The internal volume 50 is also cylindrical in shape such that thermal distribution within the internal 20 volume 50 will be more even. The internal volume 50 is insulated such that heat is retained within the internal volume 50. In this embodiment, the internal volume 50 may be surrounded by material such as Polyether Polyol and Isocyanate to provide the insulation. An internal surface of the container 20, defining the internal volume 50, is manufactured from a polymer that is chemically inert such as polypropylene. An external surface of the container 20 is 5 manufactured from a polymer that is impact and puncture resistant such as Linear low density polyethylene (LLDPE). Referring to Fig. 2, the pipes 30a, 30b, 30c, 30d are located within the internal volume 50 and immersed in the primary fluid in use. Each of the pipes 30a, 30b, 30c, 30d is adapted to 5 convey a secondary fluid. In this embodiment, the secondary fluid is water but, in other embodiments, the secondary fluid may be any other thermal conductive fluid such as synthetic oil or molten salt. Each of the pipes 30a, 30b, 30c, 30d is further adapted to facilitate heat transfer between the primary fluid and the secondary fluid by conduction. The pipes 30a, 30b, 30c, 30d are manufactured from steel which has a high thermal conductivity. 10 The pipes 30a, 30b, 30c, 30d are corrugated such that the surface area of pipes 30a, 30b, 30c, 30d between the primary fluid and the secondary fluid is increased to further promote heat transfer. In other embodiments, the pipes 30a, 30b, 30c, 30d may be manufactured from any other suitable material such as copper. Each of the pipes 30a, 30b, 30c, 30d is configured in a helix around the longitudinal axis of 15 the container 20 such that the pipes 30a, 30b, 30c, 30d are able to be compact and yet have longer lengths immersed in the primary fluid. Therefore, the surface areas of the pipes 30a, 30b, 30c, 30d are increased to further promote heat transfer between the primary and secondary fluids. In this embodiment, the pipe 30a is located at the bottom of the internal volume 20 adjacent to the bottom end 70. The pipe 30d is located at the top of the internal 20 volume 20 adjacent to the top end 60. The pipe 30c is located between the pipe 30a and the pipe 30d. The pipe 30b is located between pipe 30a and pipe 30c. The helix configuration of the pipe 30b is smaller in diameter than the helix configuration of the pipes 30a, 30c such that the pipe 30b is able to be partially within the pipes 30a, 30c. 6 Referring to Figs. 1 and 2, each of the side ports 40a, 40b, 40c, 40d, 40e is adapted to provide access to the internal volume 50. It will be appreciated that the side ports 40a, 40b, 40c, 40d, 40e are able to be sealed such that when not in use the primary fluid does not leak out of the internal volume 50. The side ports 40a, 40b, 40c, 40d, 40e are located at a side of 5 the container 20 along the length of the container 20 and aligned with each other. The side port 40a is located adjacent to the bottom end 70, the side port 40b is located above the side port 40a, the side port 40c is located above the side port 40b, the side port 40d is located above side port 40c and the side port 40e is located above side port 40d and adjacent to the top end 60. 10 In this embodiment, the ports 40a, 40b are connected to a solar heater located outside the container 20. In use, the solar heater receives the secondary fluid from the port 40a to be heated with solar energy and provides the port 40b with the secondary fluid at a heated state. In other embodiments, the ports 40a, 40b may be adapted to connect to any other heater which employs another energy source to heat the secondary fluid such as natural gas, 15 liquid petroleum gas (LPG) and oil. The ports 40a, 40b are further connected to the pipe 30a such that the secondary fluid at a heated state can be received by the pipe 30a via the port 40b, conveyed downwardly through the pipe 30a and then expelled via the port 40a at a cooled state in use. It will be appreciated that, as the secondary fluid at a heated state conveys downwardly through the pipe 30a in use, heat will transfer from the secondary fluid 20 to the primary fluid and thereby cool the secondary fluid to a cooled state and heat the primary fluid to a heated state. As the pipe 30 a is located at the bottom of the internal volume 50, due to convection the primary fluid in a heated state will rise to the top of the internal volume 50 and the primary fluid in a cooled state will fall to the bottom of the internal volume 50 to be heated by heat transferred by the secondary fluid conveying through the 7 pipe 30a in use. It will be appreciated that a pump will be utilised to allow the secondary fluid to flow from the solar heater, through the pipe 30a and back to the solar heater. The ports 40c, 40d are connected to a gas heater located outside the container 20. In use, the heater receives the primary fluid from the internal volume 50 via port 40c to be heated 5 with energy formed by the combustion of natural gas and provides the internal volume 50 with the primary fluid at a heated state via the port 40d. In other embodiments, the ports 40c, 40d may be connected to another heater which employs another energy source to heat the primary fluid such as solar, liquid petroleum gas (LPG) and oil. It will be appreciated that, due to convection the primary fluid at a heated state will rise within the internal volume 50 and the 10 primary fluid at a cooled state will fall towards the bottom of the internal volume 50. Therefore, the port 40c, located below port 40d, is able to provide the gas heater with the primary fluid at a cooler state. It will also be appreciated that a pump will be utilised to allow the primary fluid to flow to and from the gas heater. In use, in this embodiment, the solar heater indirectly heats the primary fluid and the gas 15 heater directly heats the primary fluid. The combined use of the solar heater and the gas heater allows the primary fluid to be heated even when, for example, there is limited solar energy to heat the secondary fluid. Also, when there is ample solar energy, the gas heater could be switched off to limit the combustion of natural gas. The pipes 30b, 30c, 30d are each connected to two respective top ports. In this embodiment, 20 the top ports connected to the pipe 30d are further connected to a hot water system located outside the container 20. The hot water system is adapted to provide hot water to residential or commercial buildings. In use, the hot water system provides the secondary fluid at a cooled state to the pipe 30d via one of the respective top ports such that the secondary fluid conveys upwardly through the pipe 30d and back to the hot water system via the other 8 respective top port. As the pipe 30d is located at the top of the internal volume 50 and adjacent to the top end 60, the pipe 30d is surrounded by the primary fluid at a heated state in use. Therefore, as the secondary fluid at a cooled state conveys upwardly through the pipe 30d, the secondary fluid is heated to a heated state from the heat transferred from the 5 primary fluid. Thus, when the secondary fluid is returned back to the hot water system the secondary fluid is at a heated state. It will be appreciated that the primary fluid at the top of the internal volume 50 has the highest temperature relative to the other primary fluid in the internal volume 50 such that the secondary fluid will be heated to a high temperature. The top ports connected to the pipe 30c are further connected to a hydronic heating system 10 located outside the container 20. The hydronic heating system is adapted to provide heat to a residential or commercial building. In use, the hydronic heating system provides the secondary fluid at a cooled state to the pipe 30c via one of the respective top ports such that the secondary fluid conveys upwardly through the pipe 30c and back to the hydronic heating system via the other respective top port. As the pipe 30c is located in the middle of the 15 internal volume 50, the pipe 30c is surrounded by the primary fluid at a semi heated state in use. Therefore, as the secondary fluid at a cooled state conveys upwardly through the pipe 30c, the secondary fluid is heated to a semi heated state from the heat transferred from the primary fluid. Thus, when the secondary fluid is returned back to the hydronic heating system the secondary fluid is at a semi heated state. It will be appreciated that the secondary fluid 20 only needs to be at a semi heated state to provide adequate heat for the hydronic heating system. Similarly, the top ports connected to the pipe 30b are further connected to a pool heating system located outside the container 20. The pool heating system is adapted to provide heat to a swimming pool. In use, the pool heating system provides the secondary fluid at a cooled state to the pipe 30b via one of the respective top ports such that the 9 secondary fluid conveys upwardly through the pipe 30b and back to the pool heating system via the other respective top port. As the pipe 30b is located in the middle of the internal volume 50 just below the pipe 30c, the pipe 30b is surrounded by the primary fluid at a semi heated state in use at a slightly lower temperature than the primary fluid surrounding pipe 5 30c. Therefore, as the secondary fluid at a cooled state conveys upwardly through the pipe 30b, the secondary fluid is heated to a semi heated state from the heat transferred from the primary fluid. Thus, when the secondary fluid is returned back to the pool heating system the secondary fluid is at a semi heated state. It will be appreciated that the secondary fluid only needs to be at a semi heated state to provide adequate heat for the pool heating system. 10 Interpretation Embodiments: Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the 15 phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments. 20 Similarly it should be appreciated that in the above description of example embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed 10 invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the Detailed Description of Specific Embodiments are hereby expressly incorporated into this Detailed Description of Specific 5 Embodiments, with each claim standing on its own as a separate embodiment of this invention. Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be 10 understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination. Specific Details In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific 15 details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description. Terminology In describing the preferred embodiment of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, the invention is not intended 20 to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar technical purpose. Terms such as "forward", "rearward", "radially", "peripherally", "upwardly", "downwardly", and the like are used as words of convenience to provide reference points and are not to be construed as limiting terms. 11 Comprising and Including In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" are used in an inclusive sense, 5 i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention. Any one of the terms: including or which includes or that includes as used herein is also an open term that also means including at least the elements/features that follow the term, but not excluding others. Thus, including is synonymous with and means comprising. 10 Scope of Invention Thus, while there has been described what are believed to be the preferred embodiments of the invention, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such changes and modifications as fall within the scope of the invention. For example, 15 any formulas given above are merely representative of procedures that may be used. Functionality may be added or deleted from the block diagrams and operations may be interchanged among functional blocks. Steps may be added or deleted to methods described within the scope of the present invention. Although the invention has been described with reference to specific examples, it will be 20 appreciated by those skilled in the art that the invention may be embodied in many other forms. Industrial Applicability It is apparent from the above, that the arrangements described are applicable to the industries related to heating and the manufacture of heating equipment. 12

Claims (5)

1. A heat exchanger, comprising: 5 a container adapted to house a primary fluid; two or more pipes located within the container and each adapted to convey a secondary fluid and facilitate heat transfer between the primary fluid and the secondary fluid; and four or more side ports located at a side of the container, wherein at least one 10 of the four or more side ports is adapted to allow the primary fluid to be supplied to the container at a heated state and at least one of the four or more side ports is adapted to allow the primary fluid at a cooled state to be removed from the container, and wherein at least one of the four or more side ports is adapted to allow the secondary fluid at a heated state to be supplied to a first of the two or more pipes and 15 at least one of the four or more side ports is adapted to allow the secondary fluid at a cooled state to be removed from the first of the one or more pipes.

2. A heat exchanger as claimed in claim 1, wherein the container is not pressurised.

3. A heat exchanger as claimed in claim 1, wherein an internal volume of the container is generally cylindrical in shape. 20

4. A heat exchanger as claimed in claim 1, wherein at least a portion of each of the one or more pipes is configured in a helix.

5. A heat exchanger as claimed in claim 1, further comprising two or more top ports located at a top of the container, wherein at least one of the two or more top ports is adapted to allow the secondary fluid at a cooled state to be supplied to a second of 13 the two or more pipes and at least one of the two or more top ports is adapted to allow the secondary fluid at a heated state to be removed from the second of the two or more pipes. 5 14