Medium heating device and automobile

Abstract

The embodiment of the invention discloses a medium heating device and an automobile, and the medium heating device comprises a shell which is provided with a containing cavity, and the shell is provided with a first liquid pipe and a second liquid pipe; the first flow channel and the second flow channel are accommodated in the accommodating cavity; the shell has a second direction y, and the first flow channel and the second flow channel are stacked in the second direction y; in the second direction y, the first heating element is stacked on the side, away from the second flow channel, of the first flow channel, and the second heating element is stacked on the side, away from the first flow channel, of the second flow channel. According to the water tank, the technical scheme that the double flow channels and the double heating elements are stacked is adopted, the larger heat dissipation area is achieved, the heating efficiency is improved, meanwhile, the size of the water tank is reduced, and the water tank can be suitable for more vehicle types.

Description

Technical Field

[0001] The invention relates to the technical field of electric heating devices, and in particular to a medium heating device and a car. Background Art

[0002] The car fluid heater heats the car's circulating medium (such as antifreeze, etc.) and transfers the heat directly to the car's radiator, defroster and battery, providing a heat source for low-temperature starting of the car and heating the cabin.

[0003] Car liquid heaters on the market usually use thick film or PTC as heating elements. PTC has low manufacturing cost, simple structure and fast heat output, but PTC has high energy consumption and does not meet the low energy consumption requirements of new energy vehicles. However, although the thermal conversion rate of thick film is higher than that of PTC, its heating capacity and heat dissipation capacity are lower than those of PTC. A larger area of ​​thick film is required to heat the same volume of liquid to the same temperature. Therefore, in the prior art, car liquid heaters that use thick film as heating elements occupy a larger volume in the car than car liquid heaters that use PTC as heating elements. Summary of the invention

[0004] The embodiments of the present invention provide a medium heating device and a vehicle, which can reduce the overall volume while expanding the heating area and improving the heating efficiency through a double-layer flow channel and a double-layer heating element matched therewith.

[0005] In order to solve the above technical problems, the embodiments of the present invention disclose the following technical solutions:

[0006] In one aspect, a medium heating device is provided, comprising:

[0007] A housing having a receiving cavity, wherein a first liquid pipe and a second liquid pipe are provided on the housing;

[0008] A first flow channel and a second flow channel, the first flow channel and the second flow channel are accommodated in the accommodating chamber; the shell has a second direction y, the first flow channel and the second flow channel are stacked along the second direction y; the first flow channel includes a first liquid inlet end and a first liquid outlet end, the second flow channel includes a second liquid inlet end and a second liquid outlet end, the first liquid inlet end and the second liquid inlet end are adjacent to each other and are connected to the first liquid pipe; the first liquid outlet end and the second liquid outlet end are adjacent to each other and are connected to the second liquid pipe; liquid flows into the first liquid pipe and then is separated to the first liquid inlet end and the second liquid inlet end, and liquid flows out of the first liquid outlet end and the second liquid outlet end and then merges and flows out of the second liquid pipe;

[0009] A first heating element and a second heating element, wherein in the second direction y, the first heating element is stacked on a side of the first flow channel away from the second flow channel, and the second heating element is stacked on a side of the second flow channel away from the first flow channel;

[0010] A controller is installed on one side of the shell, and the controller includes a shell and a circuit board arranged in the shell, the shell and the shell are an integrated structure, and the circuit board is electrically connected to the first heating element and the second heating element.

[0011] Additionally or alternatively to one or more of the features disclosed above, the first heating element and the second heating element are thick film heating elements.

[0012] In addition to or as an alternative to one or more of the features disclosed above, the housing further comprises a flow channel plate, which is disposed in the accommodating cavity; in the second direction y, the flow channel plate has a first surface and a second surface opposite to each other, and the first surface and the second surface are respectively provided with a first guide groove and a second guide groove;

[0013] The medium heating device further comprises: a first sealing plate and a second sealing plate, wherein the first sealing plate is arranged on the first surface, the first sealing plate and the first guide groove are arranged to form the first flow channel, and the second sealing plate and the second guide groove are arranged to form the second flow channel;

[0014] A first heating element and a second heating element, wherein the first heating element is arranged on a side of the first sealing plate away from the first flow channel, and the second heating element is arranged on a side of the second sealing plate away from the second flow channel.

[0015] In addition to or as an alternative to one or more of the features disclosed above, a first window is provided at a position of the flow channel plate close to the first liquid pipe, the first window penetrates the flow channel plate along the second direction y, and the first window connects the first flow channel and the second flow channel;

[0016] A second window is provided at a position of the flow channel plate close to the second liquid pipe. The second window penetrates the flow channel plate along the second direction y. The second window connects the first flow channel and the second flow channel.

[0017] In addition to or as an alternative to one or more of the features disclosed above, the first guide groove and the second guide groove are groove-like structures that bend back and forth between the first liquid pipe and the second liquid pipe.

[0018] In addition to or as an alternative to one or more of the features disclosed above, a plurality of ribs are provided in the first guide groove and the second guide groove.

[0019] In addition to or as an alternative to one or more of the features disclosed above, the ribs include triangular ribs.

[0020] In addition to or instead of one or more of the features disclosed above, the controller further comprises a high voltage connector, a low voltage connector and a power supply interface mounted on the circuit board and exposed from the housing, wherein the power supply interface is electrically connected to the first heating element.

[0021] In addition to or as an alternative to one or more features disclosed above, the flow channel plate has a through hole, the through hole penetrates the flow channel plate along the second direction y, and the through hole is isolated from the first flow channel and the second flow channel;

[0022] A wiring harness is provided at one end of the first heating element away from the power supply interface. The wiring harness passes through the through hole and electrically connects the first heating element and the second heating element.

[0023] On the other hand, a vehicle is further disclosed. In addition to or as an alternative to one or more of the features disclosed above, the vehicle comprises a medium heating device as described in any one of the above items.

[0024] One of the above technical solutions has the following advantages or beneficial effects: The technical solution of the present application adopts a technical solution of stacking double flow channels and double heating elements, which has a larger heat dissipation area, improves heating efficiency, reduces the volume of the water tank, and can be adapted to more types of vehicles. Under the same flow rate, the flow resistance of the double-layer flow channel is smaller than that of the single-layer flow channel, which better matches the requirements of various OEMs for flow resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The technical solutions and other beneficial effects of the present invention will be made apparent by describing in detail the specific embodiments of the present invention in conjunction with the accompanying drawings.

[0026] Figure 1 is a structural schematic diagram of a medium heating device provided according to an embodiment of the present invention;

[0027] Figure 2 is a schematic diagram of an exploded structure of a water tank in a medium heating device provided according to an embodiment of the present invention;

[0028] Figure 3 is a schematic structural diagram of a medium heating device provided according to an embodiment of the present invention after the first cover plate is removed;

[0029] Figure 4 is a schematic structural diagram of a medium heating device provided according to an embodiment of the present invention after the second cover plate is removed;

[0030] Figure 5 is a structural schematic diagram of an outer shell and a casing in a medium heating device provided according to an embodiment of the present invention;

[0031] Figure 6 is a structural schematic diagram of a shell in a medium heating device provided according to an embodiment of the present invention;

[0032] Figure 7 is a structural schematic diagram of a shell in a medium heating device provided by an embodiment of the present invention from another perspective;

[0033] Figure 8 is a structural schematic diagram of a controller in a medium heating device provided according to an embodiment of the present invention;

[0034] Fig. 9 is a bottom view of a controller in a medium heating device provided by an embodiment of the present invention with a bottom cover removed;

[0035] In the figure: 10-water tank; 100-shell; 101-first liquid pipe; 102-second liquid pipe; 103-flow channel plate; 104-through hole; 105-second through-opening; 106-rib; 110-first guide groove; 111-first liquid inlet end; 112-first liquid outlet end; 120-second guide groove; 121-second liquid inlet end; 122-second liquid outlet end; 131-first window; 132-second window; 210-first sealing plate; 220-second sealing plate; 310-first heating element; 320-second heating element; 301-wiring harness; 20-controller; 21-high voltage connector; 22-low voltage connector; 23-power supply interface; 24-circuit board; 25-shell; 251-first through-opening. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and beneficial effects of the present invention more clear, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described in this specification are only for explaining the present invention, not for limiting the present invention.

[0037] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" refers to two or more, unless otherwise clearly and specifically defined.

[0038] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0040] See also Figure 1 , Figure 2 , Figure 1 and Figure 2The structural schematic diagram and the exploded structural schematic diagram of a medium heating device in an embodiment of the present application are respectively shown. The medium heating device provided in an embodiment of the present application includes a water tank 10 and a controller 20. The water tank 10 includes a first liquid pipe 101 and a second liquid pipe 102 for the inflow and outflow of liquid respectively. The water tank 10 has a first direction x, a second direction y and a third direction z that intersect and are perpendicular to each other. The water tank 10 also includes a first flow channel and a second flow channel that enable the liquid flowing into the water tank 10 to flow in parallel and synchronously, and the first flow channel and the second flow channel are stacked along the second direction y. The first flow channel and the second flow channel are independent of each other. Combined Figure 6 As shown, the first flow channel includes a first liquid inlet end 111 for inletting liquid and a first liquid outlet end 112 for outletting liquid; the second flow channel includes a second liquid inlet end 121 for inletting liquid and a second liquid outlet end 122 for outletting liquid. After the liquid flows into the first liquid pipe 101, it is divided into the first flow channel and the second flow channel, and finally the liquid converges and flows out from the second liquid pipe 102 together. The first flow channel and the second flow channel are respectively provided with a first heating element 310 and a second heating element 320 at corresponding positions. The first heating element 310 and the second heating element 320 are respectively arranged on both sides of the second direction y of the water tank 10. The first heating element 310 and the second heating element 320 respectively cover the area through which the first flow channel and the second flow channel flow, so as to heat the liquid in the first flow channel and the second flow channel. The controller 20 is electrically connected to the first heating element 310 and the second heating element 320 in the water tank 10, and the controller 20 supplies power to the first heating element 310 and the second heating element 320 while controlling the working state.

[0041] The present application adopts a technical solution of stacking double flow channels and double heating elements, which has a larger heat dissipation area, improves the heating efficiency, reduces the volume of the water tank 10, and can be adapted to more types of vehicles. At the same flow rate, the flow resistance of the double-layer flow channel is smaller than that of the single-layer flow channel, which better matches the requirements of various OEMs for flow resistance.

[0042] Combination Figure 2 , Figure 3 , Figure 4In some embodiments, the water tank 10 includes a housing 100, a first sealing plate 210, a second sealing plate 220, a first heating element 310, a second heating element 320, a first cover plate 410 and a second cover plate 420. The water tank 10 has a first open surface and a second open surface opposite to each other on both sides of the second direction y, the first cover plate 410 and the second cover plate 420 are respectively arranged on the first open surface and the second open surface, and the housing 100, the first cover plate 410 and the second cover plate 420 surround a receiving cavity. The water tank 10 is provided with a first liquid pipe 101 and a second liquid pipe 102 at one end away from the controller 20. The plane where the first direction x and the third direction z are located is the first plane, and the housing 100 includes a flow channel plate 103 extending along the first plane, and the flow channel plate 103 has a first surface and a second surface opposite to each other on both sides of the second direction y, and a first guide groove 110 and a second guide groove 120 are provided on the first surface and the second surface of the flow channel plate 103, and the first guide groove 110 and the second guide groove 120 are both connected to the first liquid pipe 101 and the second liquid pipe 102. The first guide groove 110 and the second guide groove 120 are arranged on the flow channel plate 103 in a serpentine shape. The first guide groove 110 and the second guide groove 120 are provided with a first window 131 at the end close to the first liquid pipe 101, which connects the first guide groove 110 and the second guide groove 120, and the first window 131 penetrates the flow channel plate 103 along the second direction y, so that the liquid entering from the first liquid pipe 101 is divided into the first guide groove 110 and the second guide groove 120 at the first window 131. The first guide groove 110 and the second guide groove 120 are provided with a second window 132 at the end close to the second liquid pipe 102 to connect the first guide groove 110 and the second guide groove 120. The second window 132 penetrates the flow channel plate 103 along the second direction y, so that the liquid guided by the first guide groove 110 and the second guide groove 120 converges at the second window 132 and then flows out of the liquid tank from the second liquid pipe 102.

[0043] In this embodiment, the first guide groove 110 and the second guide groove 120 are both groove-shaped structures that bend back and forth between the first liquid pipe 101 and the second liquid pipe 102. Optionally, other bending shapes can also be set according to actual needs, which are not specifically limited here.

[0044] In this embodiment, the first guide groove 110 and the second guide groove 120 are mirror-symmetrical along the first plane where the flow channel plate 103 is located. Optionally, the first guide groove 110 and the second guide groove 120 can also be designed as a non-mirror stacked structure according to actual needs, which is not specifically limited here.

[0045] The first sealing plate 210 and the second sealing plate 220 are respectively arranged at positions corresponding to the first guide groove 110 and the second guide groove 120. The first sealing plate 210 and the second sealing plate 220 are respectively attached to and fixedly connected with the first surface and the second surface of the flow channel plate 103, so that the first guide groove 110 and the first sealing plate 210 are surrounded to form a first flow channel, and the second guide groove 120 and the second sealing plate 220 are surrounded to form a second flow channel. The extension direction of the first flow channel and the second flow channel are both parallel to the first surface or the second surface. The first sealing plate 210 and the second sealing plate 220 are not only adjacent to the first flow channel and the second flow channel respectively, but also abut the flow channel plate 103, so that heat can not only be directly transferred to the liquid in the first flow channel or the second flow channel through the first sealing plate 210 or the second sealing plate 220, but also indirectly heated by transferring heat to the flow channel plate 103 and then to the liquid in the first flow channel or the second flow channel, thereby improving the heating efficiency.

[0046] Combination Figure 6 , Figure 7 As shown, a plurality of ribs 106 are provided in the first guide groove 110 and the second guide groove 120 , and the ribs 106 are provided near the bends in the first guide groove 110 and the second guide groove 120 .

[0047] The rib 106 is a delta-wing vortex generator, i.e., a triangular rib, which can generate a longitudinal vortex with the rotation axis as the mainstream flow direction. Based on the principle of heat transfer, the temperature boundary layer can be destroyed, the convection heat transfer effect can be enhanced, the surface temperature of the heating element 310 and the heating element 320 can be reduced, and the heating performance can be improved. Furthermore, the material of the housing 100 is a metal material. Preferably, the material of the housing 100 is an aluminum alloy material, which has the advantages of good thermal conductivity, easy machining, low processing cost and high strength.

[0048] like Figure 8 , Fig. 9 As shown, Figure 8 , Fig. 9The schematic diagram and bottom view of the controller 20 in a car liquid heater according to an embodiment of the present invention are respectively shown. The controller 20 includes a housing 25, a circuit board 24 disposed in the housing 25, and a high-voltage connector 21, a low-voltage connector 22 and a power supply interface 23 mounted on the circuit board 24 and exposed from the housing 25, forming an external conductive loop of an external control signal, a low-voltage control power supply and a high-voltage load power supply. Specifically, the power supply interface 23 is electrically connected to the first heating element 310 and the second heating element 320, the high-voltage connector 21 serves as a connector for powering the first heating element 310 and the second heating element 320, and the low-voltage connector 22 provides low-voltage power supply to the circuit board 24 and receives external signals. Exemplarily, the high-voltage connector 21 is connected to the battery, and the low-voltage connector 22 is connected to the BMS or HCU.

[0049] The first heating element 310 and the second heating element 320 are respectively arranged on a side of the first sealing plate 210 away from the first flow channel and a side of the second sealing plate 220 away from the second flow channel. The first heating element 310 and the second heating element 320 are both thick film heating elements, which adopt a thick film screen printing process, and successively print an insulating medium, a heating resistor, a conductor and an insulating protective layer on the first sealing plate 210 or the second sealing plate 220, and form the thick film heating element after high temperature sintering.

[0050] The power supply interface 23 is fixedly mounted on the circuit board 24. The power supply interface 23 extends toward the water tank 10 and sequentially passes through the first through hole 251 of the housing 25 of the controller 20 and the second through hole 105 at the bottom of the housing 100 to enter the space between the first sealing plate 210 and the first cover plate 410. The power supply interface 23 is electrically connected to the first heating element 310. The first heating element 310 is provided with a wiring harness 301 extending toward the second heating element 320 at one end away from the controller 20. The wiring harness 301 passes through a through hole 104 that penetrates the flow channel plate 103 along the second direction y. The wiring harness 301 is electrically connected to the second heating element 320 so that the first heating element 310 and the second heating element 320 are connected in series. The controller 20 supplies power to the first heating element 310 and the second heating element 320 through the power supply interface 23 and the wiring harness 301.

[0051] Furthermore, if Figure 5 As shown, the housing 25 of the controller 20 and the housing 100 are an integrated structure. It should be noted that in this embodiment, the housing 25 of the controller 20 and the housing 100 are an integrated structure. In other embodiments, according to different requirements, the housing 25 of the controller and the housing 100 may also be a split structure, which is not specifically limited here.

[0052] Specifically, the power supply interface 23 has four parallel terminals, the wiring harness 301 has four parallel sub-wires, the first heating element 310 and the second heating element 320 each have two heating elements, each terminal and each sub-wire corresponds to and is electrically connected to a heating element in the first heating element 310 and the second heating element 320, and the heating elements in the first heating element 310 or the second heating element 320 are in parallel, so that when some of the heating elements fail and do not work, the heating elements on the non-faulty lines can still work normally. In this embodiment, the power supply interface 23 has four terminals and the wiring harness 301 has four parallel sub-wires. Optionally, a corresponding number of terminals and sub-wires can also be set according to the number of heating elements in the first heating element 310 and the second heating element 320, which is not specifically limited here.

[0053] The first cover plate 410 and the second cover plate 420 are respectively arranged on the first open surface and the second open surface of the shell 100. There is a certain interval between the first cover plate 410 and the first heating element 310 on the first sealing plate 210, and there is a certain interval between the second cover plate 420 and the second heating element 320 to avoid the first cover plate 410 or the second cover plate 420 from contacting the heating element and dissipating heat to the outside of the water tank 10, thereby reducing the heating efficiency of the present application.

[0054] Specifically, when the engine, battery or air conditioner needs heat, the BMS or HCU sends a working signal to the controller 20 to control the first heating element 310 and the second heating element 320 to start working, the battery supplies power, and the first heating element 310 and the second heating element 320 convert electrical energy into heat energy. The liquid passes through the first liquid pipe 101 from the external waterway, and enters the first flow channel and the second flow channel after being split at the first window 131. In this process, the liquid absorbs heat from the first heating element 310 and the second heating element 320, and flows out of the second liquid pipe 102 after converging at the second window 132, and enters the external waterway. Heat is transported to the engine, air conditioner or battery through the liquid, thereby achieving the thermal management requirements of the cockpit.

[0055] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0056] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A medium heating device, characterized in that: include: A housing having a receiving cavity, wherein a first liquid pipe and a second liquid pipe are provided on the housing; A first flow channel and a second flow channel, the first flow channel and the second flow channel are accommodated in the accommodating chamber; the shell has a second direction y, the first flow channel and the second flow channel are stacked along the second direction y; the first flow channel includes a first liquid inlet end and a first liquid outlet end, the second flow channel includes a second liquid inlet end and a second liquid outlet end, the first liquid inlet end and the second liquid inlet end are adjacent to each other and are connected to the first liquid pipe; the first liquid outlet end and the second liquid outlet end are adjacent to each other and are connected to the second liquid pipe; liquid flows into the first liquid pipe and then is separated to the first liquid inlet end and the second liquid inlet end, and liquid flows out of the first liquid outlet end and the second liquid outlet end and then merges and flows out of the second liquid pipe; A first heating element and a second heating element, wherein in the second direction y, the first heating element is stacked on a side of the first flow channel away from the second flow channel, and the second heating element is stacked on a side of the second flow channel away from the first flow channel; A controller is installed on one side of the shell, and the controller includes a shell and a circuit board arranged in the shell, the shell and the shell are an integrated structure, and the circuit board is electrically connected to the first heating element and the second heating element.

2. The medium heating device according to claim 1, characterized in that: The first heating element and the second heating element are thick film heating elements.

3. The medium heating device according to claim 1, characterized in that: The housing further comprises a flow channel plate, which is arranged in the accommodating cavity; in the second direction y, the flow channel plate has a first surface and a second surface opposite to each other, and the first surface and the second surface are respectively provided with a first guide groove and a second guide groove; The medium heating device further comprises: a first sealing plate and a second sealing plate, wherein the first sealing plate is arranged on the first surface, the first sealing plate and the first guide groove are arranged to form the first flow channel, and the second sealing plate and the second guide groove are arranged to form the second flow channel; A first heating element and a second heating element, wherein the first heating element is arranged on a side of the first sealing plate away from the first flow channel, and the second heating element is arranged on a side of the second sealing plate away from the second flow channel.

4. The medium heating device according to claim 3, characterized in that: A first window is provided at a position of the flow channel plate close to the first liquid pipe, the first window penetrates the flow channel plate along the second direction y, and the first window connects the first flow channel and the second flow channel; A second window is provided at a position of the flow channel plate close to the second liquid pipe. The second window penetrates the flow channel plate along the second direction y. The second window connects the first flow channel and the second flow channel.

5. The medium heating device according to claim 3, characterized in that: The first guide groove and the second guide groove are respectively groove-shaped structures that bend back and forth between the first liquid pipe and the second liquid pipe.

6. The medium heating device according to claim 3, characterized in that: A plurality of ribs are arranged in the first guide groove and the second guide groove.

7. The medium heating device according to claim 6, characterized in that: The ribs include triangular ribs.

8. The medium heating device according to claim 3, characterized in that: The controller further includes a high voltage connector, a low voltage connector and a power supply interface which are mounted on the circuit board and exposed from the housing, and the power supply interface is electrically connected to the first heating element.

9. The medium heating device according to claim 8, characterized in that: The flow channel plate has a through hole, the through hole penetrates the flow channel plate along the second direction y, and the through hole is isolated from the first flow channel and the second flow channel; A wiring harness is provided at one end of the first heating element away from the power supply interface. The wiring harness passes through the through hole and electrically connects the first heating element and the second heating element.

10. An automobile, characterized in that: It comprises the medium heating device as described in any one of claims 1 to 9.

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