Heater

Abstract

To provide a heater capable of miniaturizing and improving heating efficiency of a fluid.SOLUTION: A heater according to an embodiment is a heater that contacts a fluid. The heater includes at least one base portion having a plate-shaped first portion and a plate-shaped second portion intersecting the first portion and extending in a first direction, and a heat generating portion provided in at least one of the first portion and the second portion and extending in the first direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD OF THE INVENTION An embodiment of the present invention relates to a heater. [Background technology]

[0002] There are heaters that heat fluids such as air and water. Heaters that heat fluids are provided, for example, in heating devices that heat air and in hot water devices that heat water.

[0003] One such heater proposed is a PTC (Positive Temperature Coefficient) heater. When a current flows through a PTC heater, the temperature of the PTC heater rises in accordance with the magnitude of the current. When the temperature of the PTC heater exceeds the Curie temperature, the resistance of the PTC heater increases, making it difficult for current to flow through the PTC heater, and the temperature rise of the PTC heater is suppressed. When the temperature of the PTC heater drops due to the suppression of the temperature rise of the PTC heater, current flows more easily through the PTC heater, and the temperature of the PTC heater rises again. Therefore, the use of a PTC heater allows for self-control of the heating temperature.

[0004] However, the heat generated in the PTC heater is transferred to the fluid via heat exchange fins, which are made up of multiple plates arranged three-dimensionally, making it difficult to miniaturize the device when using a PTC heater.

[0005] Additionally, heaters that use thermal conduction to heat solids such as toner have been proposed. Such heaters have a flat base that extends in one direction and a heating element provided on one side of the base. Therefore, if a heater with a flat base is used to heat a fluid, it can be made smaller. However, when a heater having a flat base is used to heat a fluid, there is a problem in that it becomes difficult to improve the efficiency of heating the fluid.

[0006] Therefore, there has been a demand for the development of a heater that can be made smaller and has improved fluid heating efficiency. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-054934 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-240606 Summary of the Invention [Problem to be solved by the invention]

[0008] The problem to be solved by the present invention is to provide a heater that can be made smaller and that can improve the efficiency of heating a fluid. [Means for solving the problem]

[0009] A heater according to an embodiment is a heater that contacts a fluid, and includes at least one base portion having a plate-like first portion and a plate-like second portion intersecting the first portion and extending in a first direction; and a heat generating portion provided in at least one of the first portion and the second portion and extending in the first direction. [Effects of the Invention]

[0010] According to an embodiment of the present invention, it is possible to provide a heater that can be made smaller and that can improve the efficiency of heating a fluid. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic perspective view illustrating a heater according to an embodiment of the present invention. [Figure 2] 10A and 10B are schematic diagrams illustrating the effects of a heater according to a comparative example. [Figure 3]10(a) and 10(b) are schematic diagrams illustrating the action and effect of a heater. [Figure 4] FIG. 10 is a schematic perspective view illustrating a heater according to another embodiment. [Figure 5] FIG. 10 is a schematic perspective view illustrating a heater according to another embodiment. [Figure 6] FIG. 10 is a schematic perspective view illustrating a heater according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments will be illustrated with reference to the drawings. In the drawings, like components are designated by like reference numerals and detailed descriptions thereof will be omitted where appropriate.

[0013] The heater 1 according to this embodiment comes into contact with a fluid such as a gas or a liquid and heats the fluid. The gas is, for example, air contained in the environment in which the heater 1 is installed. The liquid is, for example, water or a solution such as a coolant liquid. However, the type of fluid is not limited to those exemplified.

[0014] FIG. 1 is a schematic perspective view illustrating a heater 1 according to the present embodiment. As shown in FIG. 1, the heater 1 includes, for example, a base portion 10, an insulating portion 20, a heat generating portion 30, a wiring portion 40, and a protective portion 50.

[0015] The base 10 extends in one direction (corresponding to an example of the first direction). The base 10 has, for example, a first portion 11 and a second portion 12. The first portion 11 and the second portion 12 extend in the direction in which the base 10 extends. The first portion 11 and the second portion 12 are plate-shaped. When viewed from the thickness direction of the first portion 11, the shape of the first portion 11 is, for example, rectangular. When viewed from the thickness direction of the second portion 12, the shape of the second portion 12 is, for example, rectangular.

[0016] The second portion 12 intersects with the first portion 11. For example, the short side of the first portion 11 is connected to the short side of the second portion 12. For example, the first portion 11 and the second portion 12 can be formed integrally.

[0017] When viewed from the extending direction of the base 10, the angle θ between the first portion 11 and the second portion 12 can be, for example, not less than 80° and not more than 160°.

[0018] The thickness of the first portion 11 is, for example, about 0.3 mm to 1.0 mm. The length (width) of the first portion 11 in a direction intersecting the direction in which the first portion 11 extends (for example, the short side direction) is, for example, about 5 mm to 15 mm. The width of the first portion 11 can be changed as appropriate depending on the number and arrangement of the heat generating portions 30 provided in the first portion 11.

[0019] The thickness of the second portion 12 is, for example, about 0.3 mm to 1.0 mm. The length (width) of the second portion 12 in a direction intersecting the direction in which the second portion 12 extends (for example, the short side direction) is, for example, about 5 mm to 15 mm. The width of the second portion 12 can be changed as appropriate depending on the number and arrangement of the heat generating portions 30 provided in the second portion 12.

[0020] In this case, the thickness of the second portion 12 may be the same as or different from the thickness of the first portion 11. In addition, the width dimension of the second portion 12 may be the same as or different from the width dimension of the first portion 11.

[0021] The length of the first portion 11 and the length of the second portion 12 in the direction in which the base 10 extends can be changed as appropriate depending on the space in which the heater 1 is provided, etc. In this case, the length of the second portion 12 can be the same as the length of the first portion 11, or can be different from the length of the first portion 11.

[0022] The first portion 11 and the second portion 12 are made of a heat-resistant material with high thermal conductivity. For example, the first portion 11 and the second portion 12 can be made of a metal such as stainless steel or an aluminum alloy, or an inorganic material such as ceramics.

[0023] In this case, the thermal conductivity of metal is higher than that of inorganic materials such as ceramics. Therefore, if the first portion 11 and the second portion 12 are made of metal, the heating time of the heater 1 can be shortened. Furthermore, the rigidity of metal is higher than that of inorganic materials such as ceramics. Therefore, if the first portion 11 and the second portion 12 are made of metal, the rigidity of the heater 1 can be improved. Furthermore, if the first portion 11 and the second portion 12 are made of metal, the base 10 can be formed by plastic processing such as bending or pressing, or by drawing. Therefore, the manufacturing cost of the base 10, and therefore the manufacturing cost of the heater 1, can be reduced.

[0024] On the other hand, inorganic materials such as ceramics generally have insulating properties, so if the first portion 11 and the second portion 12 are made of an inorganic material, the insulating portion 20 described below can be omitted. The heater 1 illustrated in FIG. 1 has a base portion 10 containing metal and an insulating portion 20.

[0025] The insulating section 20, the heat generating section 30, the wiring section 40, and the protective section 50 can be provided in at least one of the first section 11 and the second section 12. In the heater 1 illustrated in Fig. 1, the insulating section 20, the heat generating section 30, the wiring section 40, and the protective section 50 are provided in the first section 11 and the second section 12, respectively.

[0026] In this case, the insulating part 20, the heating part 30, the wiring part 40, and the protective part 50 can be provided on the concave side surface of the base 10, or on the convex side surface of the base 10, or on the concave side surface of the base 10 and the convex side surface of the base 10. In the heater 1 illustrated in FIG. 1, the insulating part 20, the heating part 30, the wiring part 40, and the protective part 50 are provided on the concave side surface of the base 10.

[0027] The insulating portion 20 is provided to insulate the conductive base portion 10 from the heat generating portion 30 and the wiring portion 40. Therefore, the insulating portion 20 covers at least the area of ​​the surface of the base portion 10 where the heat generating portion 30 and the wiring portion 40 are provided. The thickness of the insulating portion 20 is not particularly limited as long as insulation can be ensured. The insulating portion 20 is formed from a material that is heat resistant and insulating. The insulating portion 20 can be formed from, for example, ceramics or glass material. The insulating portion 20 can be formed by, for example, thermal spraying or firing.

[0028] The heat generating portion 30 converts the applied power into heat (Joule heat). The heat generating portion 30 is provided on at least one of the first portion 11 and the second portion 12 via the insulating portion 20. If the base portion 10 is made of an insulating material, the heat generating portion 30 can be provided directly on the base portion 10. The heat generating portion 30 is linear and extends in the same direction as the base portion 10 extends.

[0029] The electrical resistance value per unit length of the heat generating part 30 can be approximately uniform in the direction in which the base 10 extends, or can vary. The electrical resistance value per unit length of the heat generating part 30 illustrated in FIG. 1 is approximately uniform in the direction in which the base 10 extends. For example, the width and thickness dimensions of the heat generating part 30 illustrated in FIG. 1 are approximately constant. To change the electrical resistance value per unit length of the heat generating part 30, it is sufficient to change at least one of the width and thickness dimensions.

[0030] The heat generating portion 30 can be formed using, for example, ruthenium oxide (RuO), a silver-palladium (Ag-Pd) alloy, a silver-platinum (Ag-Pt) alloy, or the like. The heat generating portion 30 can be formed, for example, by applying a paste-like material onto the insulating portion 20 using a method such as screen printing, and then curing the paste using a method such as firing. When the base 10 is formed from an insulating material, the heat generating portion 30 can be formed, for example, by applying a paste-like material onto the base 10 using a method such as screen printing, and then curing the paste using a method such as firing.

[0031] Furthermore, although the above describes an example in which one heat generating portion 30 is provided in each of the first portion 11 and the second portion 12, multiple heat generating portions 30 may be provided in at least one of the first portion 11 and the second portion 12. In this case, the multiple heat generating portions 30 may be arranged at predetermined intervals in a direction intersecting the direction in which the base portion 10 extends. The number of multiple heat generating portions 30 may be changed as appropriate depending on the amount of heat required for the heater 1, etc.

[0032] The wiring portion 40 is provided on at least one of the first portion 11 and the second portion 12 via the insulating portion 20. When the base portion 10 is made of an insulating material, the wiring portion 40 can be provided directly on the base portion 10.

[0033] The wiring section 40 includes, for example, a terminal 41 and a wiring 42 . For example, a pair of terminals 41 may be provided. For example, one terminal 41 may be provided on one end side of the base 10 in the direction in which the base 10 extends. For example, the other terminal 41 may be provided on the other end side of the base 10 in the direction in which the base 10 extends. The pair of terminals 41 are electrically connected to a temperature control device or the like via a connector, wiring, or the like. Note that, if a conductive fluid comes into contact with the heater 1, a waterproof connector may be used, or the connection portion between the terminal 41 and the wiring may be covered with silicone resin or the like.

[0034] The wiring 42 electrically connects the terminal 41 and the heat generating portion 30. The wiring 42 can be provided between the terminal 41 and the heat generating portion 30. The wiring 42 is not necessarily required and can be omitted. For example, the terminal 41 can be directly connected to the end of the heat generating portion 30. However, as long as the wiring 42 is provided, the arrangement of the pair of terminals 41 can be changed as desired. For example, the pair of terminals 41 can be provided side by side on one end of the base 10 in the direction in which the base 10 extends. If the pair of terminals 41 are provided side by side on one end of the base 10, the heater 1 can be electrically connected to a temperature control device or the like on one end of the heater 1. This reduces the wiring space and makes the wiring work easier.

[0035] The terminals 41 and the wiring 42 are formed using a material containing, for example, silver or copper. For example, the terminals 41 and the wiring 42 can be formed by applying a paste-like material onto the insulating portion 20 using a method such as screen printing, and then curing the paste using a method such as baking. Note that, when the base 10 is formed from an insulating material, the terminals 41 and the wiring 42 can be formed by applying a paste-like material directly onto the base 10 using a method such as screen printing, and then curing the paste using a method such as baking.

[0036] The protective part 50 is provided on at least one of the first part 11 and the second part 12, for example, via the insulating part 20. The protective part 50 covers the heat generating part 30. The protective part 50 can also cover at least a part of the wiring 42. The terminals 41 are exposed from the protective part 50. Note that, when the base part 10 is made of an insulating material, the protective part 50 is provided directly on the base part 10 and covers the heat generating part 30.

[0037] The protective section 50 has, for example, the function of insulating the heat generating section 30 and the wiring 42, the function of transferring the heat generated in the heat generating section 30 to the outside, and the function of protecting the heat generating section 30 and the wiring 42 from external forces and fluids to be heated.

[0038] The protective part 50 is formed from a material that is heat-resistant and insulating, and has high chemical stability and thermal conductivity. The protective part 50 is formed from, for example, a glass material. In this case, the protective part 50 can also be formed using a glass material to which a filler containing a material with high thermal conductivity, such as aluminum oxide, has been added. The thermal conductivity of the glass material to which the filler has been added can be, for example, 2 [W / (m·K)] or more. The thickness of the protective part 50 can be, for example, approximately 10 μm to 60 μm.

[0039] The protective portion 50 can be formed, for example, by applying a paste-like material onto the insulating portion 20, the heat generating portion 30, and the wiring 42 using a method such as screen printing, and then curing the material using a method such as baking. In this case, the terminals 41 are exposed from the protective portion 50. When the base 10 is made of an insulating material, the protective portion 50 can be formed, for example, by applying a paste-like material onto the base 10, the heat generating portion 30, and the wiring 42 using a method such as screen printing, and then curing the material using a method such as baking.

[0040] The heater 1 may further be provided with a detection unit that detects the temperature of the heat generating unit 30. The detection unit may be, for example, a thermistor. The thermistor may be formed, for example, by applying a paste-like material onto the insulating unit 20 using a screen printing method or the like, and then curing the material using a baking method or the like. If the base 10 is formed from an insulating material, the detection unit may be formed, for example, by applying a paste-like material directly onto the base 10 using a screen printing method or the like, and then curing the material using a baking method or the like. The thermistor material may, for example, contain manganese and cobalt, and at least one of copper and nickel.

[0041] A wiring section electrically connected to the detection section may be provided. The wiring section may have terminals and wiring, similar to the wiring section 40 described above. In this case, the protection section 50 may cover the detection section and wiring. The terminals may be exposed from the protection section 50.

[0042] Furthermore, although the above describes an example in which the insulating section 20, the heat generating section 30, the wiring section 40, and the protective section 50 are sequentially formed on the base 10 having the first section 11 and the second section 12, it is also possible to sequentially form at least one set of the insulating section 20, the heat generating section 30, the wiring section 40, and the protective section 50 on the surface of a flat plate-like material, and then bend this to form the base 10 having the first section 11 and the second section 12. In this way, the insulating section 20, the heat generating section 30, the wiring section 40, and the protective section 50 can be easily formed, thereby reducing the manufacturing cost and shortening the manufacturing period of the heater 1.

[0043] Next, the function and effect of the heater 1 will be described. First, the function and effect of the heater 101 according to the comparative example will be described. FIG. 2 is a schematic diagram illustrating the effects of the heater 101 according to the comparative example. In FIG. 2, in order to avoid complication, only the outer shape of the heater 101 as viewed from the direction in which the heater 101 extends is depicted.

[0044] 2, when the fluid G is supplied to the heater 101 from a direction intersecting the extension direction of the heater 101, the fluid G that comes into contact with the heater 101 flows out from the end of the heater 101 in the width direction. This shortens the time that the fluid G is in contact with the heater 101, making it difficult to improve the heating efficiency of the fluid G. In this case, if the heating efficiency is improved by increasing the length of the heater 101 in the width direction, the heater 101 will become larger, which may make it difficult to install the heater 101.

[0045] 3(a) and (b) are schematic diagrams illustrating the effects of the heater 1. FIG. 3(a) and 3(b), in order to avoid complication, only the outer shape of the heater 1 as viewed from the direction in which the heater 1 extends is depicted.

[0046] As shown in FIGS. 3(a) and 3(b), the heater 1 can be provided inside the flowing fluid G. 3(a), when fluid G is supplied to the concave side portion of heater 1 from a direction intersecting the extension direction of heater 1, fluid G that comes into contact with heater 1 flows out from the short-side end of heater 1. In this case, fluid G flowing through the concave side portion of heater 1 is less likely to leave the concave side portion of heater 1, thereby improving the heating efficiency of fluid G.

[0047] Furthermore, the length of the heater 1 in the short side direction can be made shorter than the length of the heater 101 described above. In this case, even if the length of the heater 1 in the short side direction is the same as the length of the heater 101 described above, the total length of the first portion 11 and the second portion 12 can be made longer than the length of the heater 101. If the total length of the first portion 11 and the second portion 12 is longer, the heating efficiency of the fluid G can be improved.

[0048] Therefore, the heater 1 can be made compact and the efficiency of heating the fluid G can be improved.

[0049] 3(b), when fluid G is supplied to the convex side of heater 1 from a direction intersecting the extension direction of heater 1, fluid G that comes into contact with heater 1 flows out from the short-side end of heater 1. At this time, fluid G flowing through the convex side of heater 1 flows smoothly through the convex side, and therefore, a decrease in the flow velocity and flow rate of heated fluid G can be suppressed. Furthermore, as described above, it is possible to achieve a reduction in size and an improvement in the heating efficiency of the fluid G.

[0050] Furthermore, when fluid G is supplied to heater 1 from the direction in which heater 1 extends, fluid G flowing through the concave side of heater 1 is less likely to leave the concave side of heater 1, thereby improving the heating efficiency of fluid G.

[0051] Therefore, even when the fluid G is supplied to the heater 1 from the direction in which the heater 1 extends, it is possible to achieve a reduction in size and an improvement in the heating efficiency of the fluid G.

[0052] FIG. 4 is a schematic perspective view illustrating a heater 1a according to another embodiment. As shown in FIG. 4, the heater 1a may include, for example, a plurality of the bases 10 described above. The plurality of bases 10 may be arranged, for example, in a direction intersecting the direction in which the bases 10 extend. In this case, the first portion 11 of a base 10 may be connected to the second portion 12 of an adjacent base 10. The plurality of bases 10 may also be formed integrally. For example, a flat plate material may be folded multiple times to form the plurality of bases 10 integrally. The number of the plurality of bases 10 may be changed as appropriate depending on the heat generation amount required for the heater 1a, the space in which the heater 1a is provided, and the like.

[0053] 4 illustrates an example in which multiple bases 10 having the same configuration are provided, but multiple bases 10 with different configurations may be provided. For example, the angle θ between the first portion 11 and the second portion 12 may be different, the width dimensions of the first portion 11 and the width dimensions of the second portion 12 may be different, the lengths of the first portion 11 and the second portion 12 in the extending direction of the base 10 may be different, or the arrangement and number of the heat generating portions 30 may be different.

[0054] FIG. 5 is a schematic perspective view illustrating a heater 1b according to another embodiment. The heater 1b may further have at least one hole 10a formed in the base 10. In this case, as shown in Fig. 5, a plurality of holes 10a may be arranged in the direction in which the base 10 extends. The hole 10a may be formed in each of the plurality of bases 10, or may be formed in any one of the plurality of bases 10.

[0055] As described above, the fluid G supplied to the concave side portion of the base 10 or the convex side portion of the base 10 flows out from the end portion in the lateral direction of the heater 1. Therefore, if multiple bases 10 are arranged side by side in the lateral direction of the bases 10, the flow rate of the fluid G flowing in the space opposite the central region of the heater 1b may be insufficient, or the temperature of the fluid G flowing in the space opposite the central region of the heater 1b may be uneven.

[0056] If holes 10a are provided, fluid G supplied to the concave side portion of base 10 or the convex side portion of base 10 can flow through holes 10a into the space facing the central region of heater 1b. This makes it possible to prevent a shortage of the flow rate of fluid G flowing into the space facing the central region of heater 1b and to prevent temperature distribution of fluid G flowing into the space facing the central region of heater 1b.

[0057] The size, number, pitch and the like of the holes 10a can be changed as appropriate depending on the size of the heater 1b, the flow rate of the fluid G flowing in the space opposite the central region of the heater 1b and the like.

[0058] FIG. 6 is a schematic perspective view illustrating a heater 1c according to another embodiment. The heater 1c can be configured such that the position of the hole 10a in the heater 1b described above is changed. In the heater 1b described above, the hole 10a is provided at the connection between the first portion 11 and the second portion 12. Therefore, the flow direction of the fluid G flowing through the hole 10a is substantially the same as the flow direction of the fluid G supplied to the concave portion of the base 10 or the convex portion of the base 10. In contrast, in the heater 1c, the hole 10a is provided in the first portion 11. Therefore, the flow direction of the fluid G flowing through the hole 10a can be made different from the flow direction of the fluid G supplied to the concave portion of the base 10 or the convex portion of the base 10. Even in this configuration, the fluid G supplied to the concave portion of the base 10 or the convex portion of the base 10 can flow through the hole 10a into the space opposite the central region of the heater 1c. Therefore, it is possible to prevent the flow rate of the fluid G flowing in the space opposite the central region of the heater 1c from becoming insufficient and to prevent the temperature of the fluid G flowing in the space opposite the central region of the heater 1c from being unevenly distributed. Also, by changing the flow direction of the fluid G, it is possible to agitate the fluid G flowing in the space opposite the central region of the heater 1c.

[0059] Although the holes 10a are provided in the first portion 11 in FIG. 6, the holes 10a can also be provided in the second portion 12. That is, at least one hole 10a can be provided in at least one of the first portion 11, the second portion 12, and the connection portion between the first portion 11 and the second portion 12.

[0060] Furthermore, although the above describes an example in which a hole 10a is provided in each of the multiple bases 10, at least one hole 10a may be provided in at least one of the multiple bases 10. In this case, the number, arrangement, pitch dimension, etc. of the holes 10a can be appropriately set depending on the size of the heater and the flow rate and temperature of the fluid G flowing in the space opposite the central region of the heater. For example, the number, arrangement, pitch dimension, etc. of the holes 10a can be set by conducting experiments or simulations.

[0061] Furthermore, the heater 1 illustrated in FIG. 1 has one base 10, but even in such a case, the base 10 can be provided with at least one hole 10a.

[0062] Although several embodiments of the present invention have been described above, these embodiments are presented by way of example only and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, modifications, etc. can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as set forth in the claims. Furthermore, the above-described embodiments can be implemented in combination with each other.

[0063] The following are additional notes regarding the above-described embodiment.

[0064] (Appendix 1) A heater in contact with a fluid, comprising: At least one base portion extending in a first direction has a first portion having a plate shape and a second portion also having a plate shape and intersecting the first portion; a heat generating portion provided in at least one of the first portion and the second portion and extending in the first direction; A heater equipped with:

[0065] (Appendix 2) the first portion and the second portion are integrally formed, 2. The heater according to claim 1, wherein a short side of the first portion and a short side of the second portion are connected to each other.

[0066] (Appendix 3) 3. The heater according to claim 2, wherein at least one hole is provided in at least one of the first portion, the second portion, and the connection portion between the first portion and the second portion.

[0067] (Appendix 4) The base portion is provided in plurality, 4. The heater according to any one of claims 1 to 3, wherein the plurality of base portions are arranged in a second direction intersecting the first direction.

[0068] (Appendix 5) 5. The heater according to any one of claims 1 to 4, wherein the heater is provided inside the flowing fluid. [Explanation of symbols]

[0069] 1 heater, 1a to 1c heater, 10 base, 10a hole, 11 first part, 12 second part, 20 insulating part, 30 heat generating part, 40 wiring part, 50 protective part, G fluid

Claims

1. A heater in contact with a fluid, comprising: At least one base portion extending in a first direction, the base portion having a first portion having a plate shape and a second portion having a plate shape and intersecting the first portion; a heat generating portion provided in at least one of the first portion and the second portion and extending in the first direction; A heater equipped with:

2. the first portion and the second portion are integrally formed, 2. The heater according to claim 1, wherein a short side of the first portion and a short side of the second portion are connected to each other.

3. 3. The heater according to claim 2, wherein at least one hole is provided in at least one of the first portion, the second portion, and a connecting portion between the first portion and the second portion.

4. The base portion is provided in plurality, 4. The heater according to claim 1, wherein the plurality of base portions are arranged in a second direction that intersects with the first direction.

5. 4. The heater according to claim 1, wherein the heater is provided inside the flowing fluid.

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