Heaters and fluid heating devices

Abstract

The objective is to provide a heater and a fluid heating device that can suppress localized temperature increases of the heating element, even when the detection element is positioned to overlap with the heating element when viewed from a direction intersecting the base surface. [Solution] The heater according to the embodiment is a heater that comes into contact with a fluid. The heater has a plate shape and comprises a base portion that extends in a first direction and has a first surface and a second surface opposite to the first surface; a heating element provided on the side of the first surface, extending in the first direction and having a low-resistance portion; and a detection element provided at a position that overlaps with the low-resistance portion when viewed from a direction intersecting the first surface. The resistance value of the low-resistance portion is smaller than the resistance value of the portion of the heating element that does not have the low-resistance portion.

Description

Technical Field

[0001] Embodiments of the present invention relate to a heater and a fluid heating device.

Background Art

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

[0003] As such a heater, for example, a PTC (Positive Temperature Coefficient) heater has been proposed. When a current flows through the 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 value of the PTC heater increases, making it difficult for current to flow through the PTC heater, thereby suppressing the temperature rise of the PTC heater. When the temperature of the PTC heater decreases due to the suppression of its temperature rise, current easily flows through the PTC heater again, causing the temperature of the PTC heater to rise again. Therefore, the heating temperature can be self-controlled by using a PTC heater.

[0004] However, heat generated in the PTC heater is transferred to the fluid via heat exchange fins. Since a plurality of plate members are three-dimensionally arranged in the heat exchange fins, the use of a PTC heater poses a problem that miniaturization becomes difficult. There is also another problem that it is difficult to improve the heating efficiency of the fluid because the fluid is indirectly heated via the heat exchange fins.

[0005] Furthermore, a heater has been proposed that includes a plate-shaped base portion and a heating element provided on one surface side of the base portion and extending in a direction in which the base portion extends. If such a heater is used for heating a fluid, the heater can be miniaturized and the fluid can be directly heated.

[0006] Furthermore, such heaters may be equipped with a detection element to detect the temperature of the heating element. In this case, if the detection element is positioned so as to overlap with the heating element when viewed from a direction intersecting the base surface, the distance between the detection element and the heating element can be reduced. Therefore, the temperature of the heating element can be detected accurately and quickly.

[0007] However, if the detection element is positioned in this way relative to the heat-generating element, the heat dissipation from the heat-generating element may be obstructed by the detection element, causing the temperature of the heat-generating element opposite the detection element to become too high. In this case, the cross-sectional dimensions of the heating element (thickness and width) when viewed from the direction in which the heating element extends are small. Therefore, if the temperature of the heating element facing the detection element becomes too high, there is a risk that the heating element may melt or its lifespan may be shortened.

[0008] Therefore, there was a need for the development of a technology that could suppress the localized increase in the temperature of the heating element, even when the detection element is positioned to overlap with the heating element when viewed from a direction intersecting the base surface. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2014-054934 [Patent Document 2] Japanese Patent Publication No. 2001-223068 [Overview of the project] [Problems that the invention aims to solve]

[0010] The problem that the present invention aims to solve is to provide a heater and a fluid heating device that can suppress a localized increase in the temperature of a heating element, even when the detection element is positioned to overlap with the heating element when viewed from a direction intersecting the surface of the base. [Means for solving the problem]

[0011] The heater according to this embodiment is a heater that comes into contact with a fluid. The heater has a plate-like shape and has a first surface and a second surface opposite to the first surface, and a base extending in a first direction; A heating element provided on the first surface side, extending in the first direction, and having a low-resistance portion; The device comprises a detection body provided at a position overlapping the low-resistance portion when viewed from a direction intersecting the first surface; the resistance value of the low-resistance portion is smaller than the resistance value of the portion of the heating element where the low-resistance portion is not provided. [Effects of the Invention]

[0012] According to embodiments of the present invention, even when the detection element is positioned to overlap with the heating element when viewed from a direction intersecting the base surface, it is possible to provide a heater and a fluid heating device that can suppress a localized increase in the temperature of the heating element. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic plan view of the heater according to this embodiment, as seen from the side where the heating element is provided. [Figure 2] This is a schematic cross-sectional view of the heater in the direction of line AA in Figure 1. [Figure 3] This is a schematic plan view of the heater according to this embodiment, as seen from the side opposite to the side on which the heating element is provided. [Figure 4] This is a schematic cross-sectional view illustrating the arrangement of the detection body according to another embodiment. [Figure 5] This is a schematic cross-sectional view illustrating the arrangement of the detection body according to another embodiment. [Figure 6] This is a schematic diagram illustrating a fluid heating device according to this embodiment. [Modes for carrying out the invention]

[0014] Hereinafter, embodiments will be illustrated with reference to the drawings. In each drawing, similar constituent elements are denoted by the same reference numerals, and detailed descriptions thereof are omitted as appropriate.

[0015] In addition, arrow X, arrow Y, and arrow Z in each drawing represent directions that intersect each other. For example, the X direction (corresponding to an example of a first direction) may be the longitudinal direction of the base 10. For example, the Y direction may be the transverse direction (width direction) of the base 10. For example, the Z direction may be a direction (thickness direction) intersecting the surface 10a (corresponding to an example of a first surface) of the base 10.

[0016] (Heater) The heater 1 according to the present embodiment, for example, contacts a flowing fluid 100 and heats the contacted fluid 100. The fluid 100 may be, for example, a gas (e.g., air) contained in the environment where the heater 1 is installed, or a liquid such as water or a solution (e.g., coolant). However, the type of the fluid 100 is not limited to those illustrated. Hereinafter, as an example, the heater 1 for heating a liquid will be described.

[0017] FIG. 1 is a schematic plan view of the heater 1 according to the present embodiment as viewed from the side where the heating element 31 is provided. FIG. 2 is a schematic cross-sectional view of the heater 1 in FIG. 1 taken along line A-A. FIG. 3 is a schematic plan view of the heater 1 according to the present embodiment as viewed from the side opposite to the side where the heating element 31 is provided. As shown in FIG. 1 to FIG. 3, the heater 1 includes, for example, a base 10, an insulating part 20, a heat generating part 30, a protective part 40, an insulating part 50, a detection part 60, and a protective part 70.

[0018] The base portion 10 is plate-shaped and has a surface 10a and a surface 10b (corresponding to an example of a second surface) opposite to surface 10a. The base portion 10 extends in the X direction. When viewed from the Z direction, the shape of the base portion 10 is, for example, a rectangle. The shape of the base portion 10 when viewed from the Z direction can be appropriately changed according to the shape of the container 201 of the fluid heating device 200, which will be described later. For example, the shape of the base portion 10 when viewed from the Z direction may be a circle, an ellipse, a part of a circle or ellipse, a polygon, a part of a polygon, etc.

[0019] The dimensions of the base 10 in the X direction (length dimension of the base 10) and the dimensions of the base 10 in the Y direction (width dimension of the base 10) can be appropriately changed according to the dimensions of the container 201 of the fluid heating device 200 (described later) in which the heater 1 is installed, the number of heating elements 31, the dimensions of the heating elements 31 in the X and Y directions, etc. The dimensions of the base 10 in the Z direction (thickness dimension of the base 10) can be appropriately changed, for example, according to the force applied to the heater 1 when the fluid 100 flows inside the container 201.

[0020] The base 10 is formed from a material that has heat resistance and high thermal conductivity. For example, the base 10 can be formed from a metal such as stainless steel or aluminum alloy, or from an insulating material such as ceramics.

[0021] Here, the thermal conductivity of metal is higher than that of insulating materials such as ceramics. Therefore, if the base 10 is made of metal, the heating time of the heater 1 can be shortened. Also, the rigidity of metal is higher than that of insulating materials such as ceramics. Therefore, if the base 10 is made of metal, the rigidity of the heater 1 can be improved. As a result, damage to the heater 1 when the fluid 100 flows inside the container 201 can be suppressed.

[0022] On the other hand, if the base 10 is made of an insulating material, the insulating parts 20 and 50 described later can be omitted. For example, if the base 10 is made of an insulating material, the heating element 30 and the detection element 60 can be directly provided on the base 10. Furthermore, if the base portion 10 is formed from an insulating material, it is possible to suppress the occurrence of short circuits and leakage currents even when heating a conductive fluid 100.

[0023] The heater 1 illustrated in Figures 1 and 2 includes a base 10 containing metal. Therefore, an insulating section 20 is provided between the heating section 30 and the surface 10a of the base 10. An insulating section 50 is provided between the detection section 60 and the surface 10b of the base 10.

[0024] The insulating portion 20 is provided, for example, on the surface 10a of the base portion 10. The insulating portion 20 insulates the conductive base portion 10 from the heat-generating portion 30. Therefore, the insulating portion 20 covers at least the area of ​​the surface 10a of the base portion 10 where the heat-generating portion 30 is provided. The thickness of the insulating portion 20 is not particularly limited as long as insulation is ensured. The insulating portion 20 is formed from a material that has heat resistance and insulating properties. The insulating portion 20 can be formed from, for example, ceramics or glass materials. The insulating portion 20 can be formed by, for example, thermal spraying or firing.

[0025] The heating element 30 includes, for example, a heating element 31 and wiring 32. The heating element 31 and wiring 32 are provided, for example, on the surface 10a side of the base 10. If the base 10 is made of a conductive material, the heating element 31 and wiring 32 are provided on the insulating part 20. If the base 10 is made of an insulating material, the heating element 31 and wiring 32 are provided directly on the surface 10a of the base 10.

[0026] The heating element 31 converts the applied power into heat (Joule heat). For example, the heating element 31 is linear and extends in the X direction. Furthermore, in the heater 1 illustrated in Figures 1 and 2, five heating elements 31 are provided on the surface 10a side of the base 10, but at least one heating element 31 can be provided. When multiple heating elements 31 are provided, they can be arranged in a row with a predetermined interval in the Y direction.

[0027] Furthermore, when multiple heating elements 31 are provided, it is preferable that the dimensions of the heating elements 31 in the X direction (length dimension of the heating element 31), the dimensions of the heating elements 31 in the Y direction (width dimension of the heating element 31), and the dimensions of the heating elements 31 in the Z direction (thickness dimension of the heating element 31) are all approximately the same. In this way, the amount of heat generated by the multiple heating elements 31 will be approximately the same, so the temperature variation within the plane of the heater 1 can be reduced.

[0028] Furthermore, when multiple heating elements 31 are provided, they can be connected in series, in parallel, or in series and parallel. In the heater 1 illustrated in Figures 1 and 2, five heating elements 31 are connected in series.

[0029] The number, arrangement, length, width, thickness, and connection configuration of the heating elements 31 can be appropriately changed according to the amount of heat required from the heater 1 and the size of the container 201 in which the heater 1 is installed.

[0030] The heating element 31 can be formed using, for example, ruthenium oxide (RuO2), silver-palladium (Ag-Pd) alloy, silver-platinum (Ag-Pt) alloy, etc. The heating element 31 can be formed by, for example, applying a paste-like material onto the insulating part 20 using a screen printing method, and then hardening it using a firing method, etc. If the base 10 is made of an insulating material, the heating element 31 can be formed by, for example, applying a paste-like material onto the surface 10a of the base 10 using a screen printing method, and then hardening it using a firing method, etc.

[0031] The thickness of the heating element 31 formed in this manner is, for example, about 0.005 mm to 0.02 mm, and the width of the heating element 31 is, for example, about 0.5 mm to 4 mm.

[0032] The wiring 32 has, for example, a terminal 32a and a connection portion 32b. Terminal 32a is electrically connected to the heating element 31. For example, a pair of terminals 32a may be provided. Terminal 32a may be provided, for example, near the end of the base 10 in the X direction.

[0033] The pair of terminals 32a are electrically connected to a controller 203 (described later) via a connector or external wiring. If a conductive fluid 100 comes into contact with the heater 1, a waterproof connector can be used, or the connection between the terminals 32a and the external wiring can be covered with silicone resin or the like.

[0034] The connection section 32b is provided, for example, to connect multiple heating elements 31 in series, in parallel, or in series-parallel. In Figure 1, five heating elements 31 are connected in series by four connection sections 32b. Note that if only one heating element 31 is provided, the connection sections 32b can be omitted.

[0035] Furthermore, the connection part 32b can also electrically connect the heating element 31 and the terminal 32a. In this way, the pair of terminals 32a can be placed at any position, which simplifies the wiring work when connecting the heater 1 to the controller 203 or the like, and reduces the wiring space required.

[0036] The terminals 32a and the connecting portion 32b are formed using materials such as silver or copper. For example, the terminals 32a and the connecting portion 32b can be formed by applying a paste-like material onto the insulating portion 20 using a screen printing method or the like, and then curing it using a firing method or the like. If the base portion 10 is made of an insulating material, the terminals 32a and the connecting portion 32b can be formed by applying a paste-like material onto the surface 10a of the base portion 10 using a screen printing method or the like, and then curing it using a firing method or the like.

[0037] The protective portion 40 is provided on the side of the base portion 10 where the heating portion 30 is provided. The protective portion 40 is provided, for example, on the insulating portion 20 and covers the heating element 31 and the connecting portion 32b. In this case, the terminal 32a is exposed from the protective portion 40. If the base portion 10 is formed from an insulating material, the protective portion 40 is provided, for example, directly on the surface 10a of the base portion 10 and covers, for example, the heating element 31 and the connecting portion 32b.

[0038] The protective unit 40 has, for example, the function of insulating the heating element 31 and the connecting part 32b, the function of transferring the heat generated in the heating element 31 to the outside, and the function of protecting the heating element 31 and the connecting part 32b from external forces and the fluid 100 to be heated.

[0039] The protective part 40 is formed from a material that has heat resistance and insulation properties, as well as high chemical stability and thermal conductivity. For example, the protective part 40 is formed from a glass material. In this case, the protective part 40 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 40 can be, for example, about 10 μm to 60 μm.

[0040] The protective portion 40 can be formed, for example, by applying a paste-like material onto the insulating portion 20, the heating element 31, and the connecting portion 32b using a screen printing method, and then curing it using a firing method. If the base portion 10 is made of an insulating material, the protective portion 40 can be formed, for example, by applying a paste-like material onto the surface 10a of the base portion 10, the heating element 31, and the connecting portion 32b using a screen printing method, and then curing it using a firing method.

[0041] The detection unit 60 can be provided on either the surface 10a side or the surface 10b side of the base 10. In the heater 1 illustrated in Figures 1 to 3, the detection unit 60 is provided on the surface 10b side of the base 10.

[0042] If the base portion 10 is made of metal and the detection portion 60 is provided on the surface 10b side of the base portion 10, an insulating portion 50 can be provided on the surface 10b of the base portion 10. The insulating portion 50 can be the same as the insulating portion 20 described above. If the base portion 10 is made of an insulating material, the insulating portion 50 can be omitted.

[0043] If an insulating portion 50 is provided, the detection portion 60 is provided on the insulating portion 50. If the insulating portion 50 is omitted, the detection portion 60 is provided on the surface 10b of the insulating base portion 10.

[0044] The detection unit 60 includes, for example, a detection body 61 and wiring 62. The detection body 61 can be, for example, a thermistor. The detection body 61 can be formed by, for example, applying a paste-like material onto the insulating part 50 using a screen printing method and curing it using a firing method. If the base 10 is made of an insulating material, the detection body 61 can be formed by, for example, applying a paste-like material to the surface 10b of the base 10 using a screen printing method and curing it using a firing method. The material of the thermistor can include, for example, manganese and cobalt, and at least one of copper and nickel.

[0045] Furthermore, the thermistor can also be a chip-shaped element. The chip-shaped thermistor can be mounted on the connection portion 62b of the wiring 62.

[0046] The thermistor can be, for example, an NTC (negative temperature coefficient) thermistor, a PTC (positive temperature coefficient) thermistor, or a CTR (critical temperature resistor) thermistor.

[0047] In this case, the resistance of a PTC thermistor increases rapidly with increasing temperature. The resistance of a CTR thermistor decreases rapidly with increasing temperature. Therefore, if the detection element 61 is a PTC thermistor or a CTR thermistor, temperature abnormalities of the heat-generating element 31 can be detected quickly. Furthermore, although the controllability is reduced compared to an NTC thermistor, it is also possible to control the temperature of the heat-generating element 31, and consequently the temperature of the fluid 100, using a PTC thermistor or a CTR thermistor.

[0048] An NTC thermistor exhibits a gradual decrease in resistance as its temperature rises. Therefore, if the detection element 61 is an NTC thermistor, it becomes easier to keep the temperature of the fluid 100 within a predetermined range. Furthermore, although its responsiveness is reduced compared to PTC and CTR thermistors, an NTC thermistor can also be used to detect temperature anomalies in the heat-generating element 31.

[0049] The type of thermistor can be selected according to specifications such as the required heat output for heater 1 and the state of the fluid 100. In this case, since an abnormal temperature of the heating element 31 can lead to melting or shortening of the heating element 31's lifespan, it is preferable to use a PTC thermistor or CTR thermistor from a safety standpoint.

[0050] Furthermore, a detection unit equipped with a PTC thermistor or CTR thermistor for detecting temperature abnormalities of the heating element 31 may be provided, and a detection unit equipped with an NTC thermistor for controlling the temperature of the heating element 31 may also be provided.

[0051] The wiring 62 has, for example, a terminal 62a and a connection portion 62b. Terminal 62a is electrically connected to the detection body 61. For example, a pair of terminals 62a can be provided. Terminal 62a can be provided, for example, near the end of the base 10. For example, as shown in Figure 3, a pair of terminals 62a can be provided near one end of the base 10 in the X direction.

[0052] The pair of terminals 62a are electrically connected to the controller 203, which will be described later, for example, via a connector or external wiring. If a conductive fluid 100 comes into contact with the heater 1, a waterproof connector can be used, or the connection between the terminals 62a and the external wiring can be covered with silicone resin or the like.

[0053] The connection part 62b electrically connects, for example, the detection body 61 and the terminal 62a. The terminals 62a and the connecting portion 62b are formed using materials such as silver or copper. For example, the terminals 62a and the connecting portion 62b can be formed by applying a paste-like material onto the insulating portion 50 using a screen printing method or the like, and then curing it using a firing method or the like. If the base portion 10 is made of an insulating material, the terminals 62a and the connecting portion 62b can be formed by applying a paste-like material onto the surface 10b of the base portion 10 using a screen printing method or the like, and then curing it using a firing method or the like.

[0054] The protective portion 70 is provided on the side of the base portion 10 where the detection portion 60 is provided. The protective portion 70 is provided, for example, on the insulating portion 50 and covers the detection body 61 and the connection portion 62b. In this case, the terminal 62a is exposed from the protective portion 70. If the base portion 10 is formed from an insulating material, the protective portion 70 is provided, for example, directly on the surface 10b of the base portion 10 and covers, for example, the detection body 61 and the connection portion 62b.

[0055] The protective part 70 has, for example, the function of insulating the detection body 61 and the connection part 62b, and the function of protecting the detection body 61 and the connection part 62b from external forces and the fluid 100 that is subject to heating. The material and forming method of the protective part 70 can be the same as, for example, the material and forming method of the protective part 40.

[0056] Here, the coefficient of linear expansion of the base 10 is different from the coefficient of linear expansion of the insulating part 20 and the protective part 40. Therefore, for example, when the heating element 31 generates heat, thermal stress may occur between the base 10 and the insulating part 20 and protective part 40, causing significant warping of the heater 1.

[0057] In this case, if the insulating part 50 and the protective part 70 are provided, thermal stress can also be generated on the surface 10b side of the base part 10. Therefore, the thermal stress generated on the surface 10a side of the base part 10 can be offset by the thermal stress generated on the surface 10b side of the base part 10, thus suppressing warping of the heater 1. In this case, if the material and volume of the insulating part 50 and the protective part 70 are made to be approximately the same as the material and volume of the insulating part 20 and the protective part 40, warping of the heater 1 can be effectively suppressed.

[0058] On the other hand, if the insulating part 50 and the protective part 70 are provided only in the area where the detection part 60 is provided, the material costs of the insulating part 50 and the protective part 70 can be reduced, and consequently, the manufacturing cost of the heater 1 can be reduced.

[0059] Here, if the detection element 61 is located near the heating element 31, the temperature of the heating element 31 can be detected accurately and quickly. In this case, if the detection element 61 is located in a position that overlaps with the heating element 31 when viewed from a direction intersecting the surface 10a of the base 10, the distance between the detection element 61 and the heating element 31 can be reduced. Therefore, the temperature of the heating element 31 can be detected accurately and quickly.

[0060] However, if the position of the detection element 61 relative to the heating element 31 is as described, the heat dissipation from the heating element 31 may be obstructed by the detection element 61, causing the temperature of the heating element 31 facing the detection element 61 to become excessively high.

[0061] As described above, the heating element 31 is formed by applying a paste-like material to the insulating part 20 or to the surface 10a of the insulating base part 10 using a screen printing method or the like, and then curing it using a firing method or the like.

[0062] Therefore, when viewed from the direction in which the heating element 31 extends, the cross-sectional dimensions of the heating element 31 (the thickness dimension of the heating element 31 and the width dimension of the heating element 31) become smaller. As a result, if the temperature of the heating element 31 becomes locally high, there is a risk that the heating element 31 may melt or break in the area where the temperature of the heating element 31 has become locally high, or that the lifespan of the heating element 31 may be shortened.

[0063] Therefore, as shown in Figure 1, the heating element 31 has a low-resistance section 31a. The low-resistance section 31a is electrically connected to the heating element 31. The resistance value of the low-resistance section 31a is smaller than the resistance value of the portion of the heating element 31 where the low-resistance section 31a is not provided.

[0064] If the low-resistance section 31a is electrically connected to the heating element 31, then when power is applied to the heating element 31, power is also applied to the low-resistance section 31a. Since the resistance value of the low-resistance section 31a is smaller than the resistance value of the part of the heating element 31 where the low-resistance section 31a is not provided, the amount of heat generated by the low-resistance section 31a when power is applied to both the heating element 31 and the low-resistance section 31a will be less than the amount of heat generated by the part of the heating element 31 where the low-resistance section 31a is not provided.

[0065] Therefore, even if heat dissipation from the low-resistance section 31a is obstructed by the detection element 61, it is possible to suppress the temperature of the low-resistance section 31a from rising. By suppressing the temperature of the low-resistance section 31a, it is possible to prevent the low-resistance section 31a from melting or its lifespan from being shortened.

[0066] Furthermore, there is a positive correlation between the temperature of the low-resistance section 31a and the temperature of the portion of the heating element 31 that does not have the low-resistance section 31a. Therefore, if the relationship between the temperature of the low-resistance section 31a and the temperature of the portion of the heating element 31 that does not have the low-resistance section 31a is determined in advance through experiments or simulations, the temperature of the heating element 31 can be determined from the temperature of the low-resistance section 31a detected by the detector 61.

[0067] If the temperature of the portion of the heating element 31 that does not have a low-resistance portion 31a can be determined from the temperature of the low-resistance portion 31a, then the temperature of the heating element 31, and consequently the temperature of the fluid 100, can be controlled. Furthermore, when the power applied to the heating element 31 fluctuates, or when the temperature or flow rate of the fluid 100 fluctuates, the temperature of the part of the heating element 31 that does not have a low-resistance section 31a may become too high, potentially causing the small cross-sectional portion of the heating element 31 that does not have a low-resistance section 31a to melt or shortening the lifespan of the heating element 31. If the temperature of the part of the heating element 31 that does not have a low-resistance section 31a can be determined, it is possible to detect when the temperature of the heating element 31 has become too high. If the temperature of the heating element 31 has become too high, the power application to the heating element 31 can be stopped or the power applied to the heating element 31 can be reduced.

[0068] However, if the resistance value of the low-resistance section 31a is made too small, there is a risk that the temperature variation within the plane of the heater 1 will increase. Therefore, the resistance value of the low-resistance section 31a should be set such that the temperature of the low-resistance section 31a, whose heat dissipation is suppressed by the detection element 61, is approximately the same as the temperature of the portion of the heating element 31 where the low-resistance section 31a is not provided.

[0069] The resistance value of the low-resistance portion 31a can be set by, for example, at least one of the dimensions of the low-resistance portion 31a in the Y direction (width dimension of the low-resistance portion 31a), the dimensions of the low-resistance portion 31a in the Z direction (thickness dimension of the low-resistance portion 31a), the dimensions of the low-resistance portion 31a in the X direction (length dimension of the low-resistance portion 31a), and the material of the low-resistance portion 31a.

[0070] For example, when viewed from the X direction, the cross-sectional dimensions of the low-resistance section 31a (width and thickness) can be made larger than the cross-sectional dimensions of the heating element 31 in the portion where the low-resistance section 31a is not provided (width and thickness). In this way, the resistance value of the low-resistance section 31a can be made smaller than the resistance value of the heating element 31 in the portion where the low-resistance section 31a is not provided. Furthermore, if the cross-sectional dimensions of the low-resistance section 31a are made larger, even if the temperature of the low-resistance section 31a rises due to heat dissipation being suppressed by the detection element 61, it is possible to suppress the melting of the low-resistance section 31a or shortening of its lifespan.

[0071] Furthermore, for example, by reducing the length dimension of the low-resistance section 31a in the X direction, the resistance value of the low-resistance section 31a can be reduced. However, if the resistance value of the low-resistance portion 31a is set based on its length, the portion where the temperature is low may become too small, potentially reducing the detection accuracy of the detection body 61. Therefore, it is preferable to set the resistance value of the low-resistance portion 31a based on at least one of its width, thickness, and material. In this case, the length of the low-resistance portion 31a can be, for example, approximately the same as the dimensions of the detection body 61 in the X direction (length of the detection body 61). For example, the length of the low-resistance portion 31a can be approximately 3 mm to 20 mm.

[0072] When setting the resistance value of the low-resistance portion 31a by its width dimension, the heating element 31 having the low-resistance portion 31a can be formed as follows. For example, by providing a screen printing plate with holes for forming the portion of the heating element 31 that does not have a low-resistance portion 31a, and holes for forming the low-resistance portion 31a, a heating element 31 having a low-resistance portion 31a can be formed in one step. This simplifies the manufacturing process and, consequently, reduces manufacturing costs. It also shortens the manufacturing period.

[0073] Furthermore, when setting the resistance value of the low-resistance section 31a by its material, the material of the low-resistance section 31a should be different from the material of the heating element 31. For example, the low-resistance section 31a can be formed using a material with a lower resistance value than the material of the heating element 31. For example, if the material of the heating element 31 is a silver-palladium alloy, the material of the low-resistance section 31a can be a silver-palladium alloy with a higher silver content than the silver-palladium alloy contained in the heating element 31, thereby lowering its resistance value. Alternatively, the low-resistance section 31a can be formed using a material with a lower resistance value obtained by adding a material with high conductivity to the material of the heating element 31.

[0074] When setting the resistance value of the low-resistance portion 31a by at least one of the thickness dimension of the low-resistance portion 31a and the material of the low-resistance portion 31a, for example, the formation of the portion of the heating element 31 that does not have the low-resistance portion 31a and the formation of the low-resistance portion 31a can be carried out separately.

[0075] Figure 4 is a schematic cross-sectional view illustrating the arrangement of the detection body 61 according to another embodiment. As shown in Figure 4, the detection body 61 and the low-resistance portion 31a can be provided on the surface 10a side of the base portion 10. In this case, the detection body 61 can be provided on the protective portion 40, and the protective portion 41 can cover the detection body 61 and the connecting portion 62b. The material and forming method of the protective portion 41 can be the same as, for example, the material and forming method of the protective portion 40.

[0076] Furthermore, when viewed from a direction intersecting the surface 10a of the base 10, the detection element 61 can be positioned to overlap with the low-resistance portion 31a. In this case, the distance between the detection element 61 and the low-resistance portion 31a in the Z direction should be determined considering the dielectric strength. For example, the distance between the detection element 61 and the low-resistance portion 31a in the Z direction can be 0.3 mm or more. Therefore, the distance between the detection element 61 and the low-resistance portion 31a in the Z direction can be made smaller than the thickness dimension of the base 10, allowing for more accurate and rapid detection of the temperature of the low-resistance portion 31a.

[0077] Furthermore, as shown in Figure 4, even when the detection body 61 is provided on the surface 10a side of the base 10, the protective part 70 can also be provided on the surface 10b side of the base 10. In this way, the thermal stress generated on the surface 10a side of the base 10 can be offset by the thermal stress generated on the surface 10b side of the base 10. Therefore, warping of the heater 1 can be suppressed.

[0078] Figure 5 is a schematic cross-sectional view illustrating the arrangement of the detection body 61 according to another embodiment. As shown in Figure 5, the detection element 61 and the low-resistance portion 31a can be provided on the surface 10a side of the base portion 10. In this case, the detection element 61 can be provided on the insulating portion 20, and a protective portion 42 can be provided to cover the detection element 61 and the connecting portion 62b. The heating element 31, the low-resistance portion 31a, and the protective portion 40 can be provided on the protective portion 42. The material and forming method of the protective portion 42 can be the same as, for example, the material and forming method of the protective portion 40.

[0079] Furthermore, when viewed from a direction intersecting the surface 10a of the base 10, the detection element 61 can be positioned to overlap with the low-resistance portion 31a. In this case, the distance between the detection element 61 and the low-resistance portion 31a in the Z direction should be determined considering the dielectric strength. For example, the distance between the detection element 61 and the low-resistance portion 31a in the Z direction can be 0.3 mm or more. Therefore, the distance between the detection element 61 and the low-resistance portion 31a in the Z direction can be made smaller than the thickness dimension of the base 10, allowing for more accurate and rapid detection of the temperature of the low-resistance portion 31a.

[0080] Furthermore, the detection element 61 is located between the low-resistance section 31a and the base section 10. As a result, the distance between the detection element 61 and the fluid 100 is increased, which suppresses fluctuations in the detection value by the detection element 61 when the temperature of the fluid 100 pulsates.

[0081] Furthermore, as shown in Figure 5, even when the detection body 61 is provided on the surface 10a side of the base 10, the protective part 70 can also be provided on the surface 10b side of the base 10. In this way, the thermal stress generated on the surface 10a side of the base 10 can be offset by the thermal stress generated on the surface 10b side of the base 10. Therefore, warping of the heater 1 can be suppressed.

[0082] As explained above, when viewed from a direction intersecting the surface 10a of the base 10, a low-resistance portion 31a is provided on the heating element 31 at a position overlapping with the detection element 61. Therefore, even if heat dissipation from the low-resistance portion 31a is obstructed by the detection element 61, it is possible to suppress the temperature of the low-resistance portion 31a from rising. In other words, by using a heating element 31 with a low-resistance portion 31a, it is possible to suppress the localized increase in the temperature of the heating element 31. Therefore, it is possible to prevent the heating element 31 (low-resistance portion 31a) from melting or shortening the lifespan of the heating element 31 (low-resistance portion 31a).

[0083] (Fluid heating device) In one embodiment of the present invention, a fluid heating device 200 equipped with a heater 1 can be provided. The above-described description of the heater 1, and variations of the heater 1 (for example, the arrangement of the detection body 61 relative to the low-resistance section 31a, or additions, deletions, or design changes of components as appropriate by those skilled in the art, which are all characterized by the present invention) can be applied to the fluid heating device 200.

[0084] In the following explanation, we will describe the case where two heaters 1 are provided as an example. However, the number of heaters 1 is not limited to this. It is sufficient to have at least one heater 1.

[0085] Figure 6 is a schematic diagram illustrating the fluid heating device 200 according to this embodiment. As shown in Figure 6, the fluid heating device 200 includes, for example, a heater 1, a container 201, a supply unit 202, and a controller 203.

[0086] The container 201 has an internal space into which the fluid 100 is supplied. There are no particular limitations on the external shape of the container 201. For example, the external shape of the container 201 may be a rectangular parallelepiped, a cylinder, a prism, a sphere, etc. The external shape of the container 201 illustrated in Figure 6 is a rectangular parallelepiped. The container 201 may also be bent or curved. The external shape of the container 201 can be appropriately changed depending on the environment in which the container 201 is installed.

[0087] The container 201 is provided with a supply pipe 201a and a discharge pipe 201b. For example, the supply pipe 201a can be provided at one end of the container 201 in the X direction. The discharge pipe 201b can be provided at the other end of the container 201 in the X direction.

[0088] A heater 1 is provided inside the container 201. In the X direction, the heater 1 extends from one inner wall side to the other inner wall side of the container 201. Therefore, the heater 1 is immersed in the fluid 100 supplied to the inside of the container 201, and the fluid 100 flows along the longitudinal direction of the heater 1. In this way, the heating efficiency of the fluid 100 can be improved.

[0089] The supply unit 202 is connected to the supply pipe 201a of the container 201 via piping or the like. The supply unit 202 supplies fluid 100 into the container 201. If the fluid 100 is a liquid, the supply unit 202 may include, for example, a tank and a pump. If the fluid 100 is a gas, the supply unit 202 may be a blower such as a fan. The supply unit 202 may also be a factory pipe or the like that supplies the fluid 100.

[0090] The controller 203 controls the operation of each element provided in the fluid heating device 200. The controller 203 may include, for example, a computer, a temperature control device, and a power supply.

[0091] For example, the controller 203 is electrically connected to the supply unit 202 and to the heating element 31 and detection element 61 provided on the heater 1.

[0092] For example, the controller 203 controls the power applied to the heating element 31, and consequently the temperature of the fluid 100, based on the signal from the detection element 61. Furthermore, if the temperature detected by the detection element 61 exceeds a predetermined temperature, the controller 203 can stop or reduce the power applied to the heating element 31. In this case, the controller 203 can also issue an alarm.

[0093] For example, the controller 203 controls the supply unit 202 to control the flow rate of the fluid 100 supplied into the container 201, and consequently, the flow rate of the heated fluid 100 discharged from the container 201.

[0094] For example, in the case of a hot water system or a hot air system that consumes a fluid 100 heated by a heater 1, a tank 300 for storing the heated fluid 100 and a nozzle for discharging the heated fluid 100 can be connected to the discharge pipe 201b of the container 201 via piping or the like.

[0095] Furthermore, when the fluid 100 is used as a heat transfer medium, the heated fluid 100 can be supplied to the component 400 to be heated. For example, if the temperature of the battery installed in an EV (Electric Vehicle) becomes too low, the rate of chemical reactions occurring within the battery slows down, and the amount of electricity that can be generated decreases. In such cases, the heated fluid 100 (for example, coolant) can be supplied to the outer wall of the battery to keep the battery temperature within an appropriate range.

[0096] Furthermore, when the fluid 100 is used as a heat transfer medium, the fluid 100 discharged from the component 400 (the fluid 100 used to heat the component 400) can be recovered and reused. For example, the fluid 100 discharged from the component 400 can be returned to the tank of the supply unit 202. In this way, the fluid 100 circulates between the component 400 and the tank, which can suppress the consumption of the fluid 100 or reduce the power consumption of the heater 1 by reheating the high-temperature fluid 100.

[0097] Although several embodiments of the present invention have been illustrated above, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. Furthermore, the embodiments described above can be implemented in combination with each other.

[0098] The following are additional notes regarding the embodiments described above.

[0099] (Note 1) A heater that comes into contact with a fluid, It has a plate-like shape, a first surface, a second surface facing the first surface, and a base extending in a first direction; A heating element provided on the first surface side, extending in the first direction, and having a low-resistance portion; A detection body provided at a position overlapping with the low-resistance portion when viewed from a direction intersecting the first surface; It is equipped with, A heater in which the resistance value of the low-resistance portion is smaller than the resistance value of the portion of the heating element in which the low-resistance portion is not provided.

[0100] (Note 2) The detection body is a heater as described in Appendix 1, provided on the first side or the second side.

[0101] (Note 3) The heater according to Appendix 1 or 2, wherein, when viewed from the first direction, the cross-sectional dimensions of the low-resistance portion are larger than the cross-sectional dimensions of the portion of the heating element where the low-resistance portion is not provided.

[0102] (Note 4) The heater according to Appendix 1 or 2, wherein the material of the low-resistance portion is different from the material of the portion of the heating element where the low-resistance portion is not provided.

[0103] (Note 5) A container having a space inside into which a fluid is supplied; A heater as described in Appendix 1 or 2 is provided inside the container; A fluid heating device equipped with the following. [Explanation of Symbols]

[0104] 1 Heater, 10 Base, 10a Surface, 10b Surface, 20 Insulation, 30 Heating element, 31 Heating component, 31a Low-resistance component, 60 Detection unit, 61 Detection element, 100 Fluid, 200 Fluid heating device, 201 Container, 202 Supply unit, 203 Controller

Claims

1. A heater that comes into contact with a fluid, It has a plate-like shape, a first surface, a second surface facing the first surface, and a base portion extending in a first direction; A heating element provided on the first surface side, extending in the first direction, and having a low-resistance portion; A detection body provided in a position overlapping with the low-resistance portion when viewed from a direction intersecting the first surface; It is equipped with, A heater in which the resistance value of the low-resistance portion is smaller than the resistance value of the portion of the heating element in which the low-resistance portion is not provided.

2. The heater according to claim 1, wherein the detection body is provided on the first side or the second side.

3. The heater according to claim 1 or 2, wherein, when viewed from the first direction, the cross-sectional dimensions of the low-resistance portion are greater than the cross-sectional dimensions of the portion of the heating element in which the low-resistance portion is not provided.

4. The heater according to claim 1 or 2, wherein the material of the low-resistance portion is different from the material of the portion of the heating element in which the low-resistance portion is not provided.

5. A container having a space inside into which a fluid is supplied; A heater according to claim 1 or 2 is provided inside the container; A fluid heating device equipped with the following.

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