Heat generating structure and heat generating device

Abstract

The present invention provides a heating structure and a heating device capable of improving the stability and controllability of heat generation by a heating element. The heating structure (2) includes a silicon substrate (13) and a heating element (14) that generates heat by absorbing and releasing hydrogen, the heating element (14) has a support (61) provided on the silicon substrate (13) and a multilayer film (62) provided on the support (61), the support (61) being formed of at least one of a porous body, a hydrogen permeable film, and a proton conductor, the multilayer film (62) having a first layer (71) less than 1000 nm thick and made of a hydrogen storage metal or a hydrogen storage alloy, and a second layer (72) less than 1000 nm thick and made of a hydrogen storage metal, a hydrogen storage alloy, or a ceramic different from the first layer (71).

Description

[Technical field]

[0001] The present invention relates to a heat generating structure and a heat generating device. [Background technology]

[0002] In recent years, a heat generation phenomenon has been reported in which nanostructures formed from hydrogen storage metals and the like generate heat by absorbing and releasing hydrogen (see Non-Patent Document 1). This heat generation phenomenon can produce greater thermal energy than chemical reactions, so it is expected to be used as an effective heat source or power source.

[0003] The inventors of the present application have previously proposed a heating device including a heating element having a base made of a hydrogen storage metal, a hydrogen storage alloy, or a proton conductor, and a multilayer film formed on the surface of the base (see Patent Document 1). The heating element is provided inside a container into which hydrogen-based gas that contributes to heat generation is introduced. The multilayer film has a structure in which a first layer made of a hydrogen storage metal or a hydrogen storage alloy and having a thickness of less than 1000 nm and a second layer made of a hydrogen storage metal, a hydrogen storage alloy, or a ceramic different from the first layer and having a thickness of less than 1000 nm are laminated, and a heterogeneous material interface is formed between the first layer and the second layer. In the heating device of Patent Document 1, after hydrogen is absorbed in the heating element, the heating element is heated by a heater and the inside of the container is evacuated, whereby hydrogen permeates the heterogeneous material interface by quantum diffusion, or hydrogen diffuses through the heterogeneous material interface by quantum diffusion, generating heat in the heating element. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] A. Kitamura, A. Takahashi, K. Takahashi, R. Seto, T. Hatano, Y. Iwamura, T. Itoh, J. Kasagi, M. Nakamura, M. Uchimura, H. Takahashi, S. Sumitomo, T. Hioki, T. Motohiro, Y. Furuyama, M. Kishida, H. Matsune, “Excess heat evolution from nanocomposite samples under exposure to “hydrogen isotope gases”, International Journal of Hydrogen Energy 43 (2018) 16187-16200. [Patent documents]

[0005] [Patent Document 1] International Publication No. 2018 / 230447 Summary of the Invention [Problem to be solved by the invention]

[0006] However, when minute irregularities occur on the surface of the base, it is difficult to form a smooth interface between different materials, which poses a problem of reduced stability and controllability of heat generation by the heating element.

[0007] An object of the present invention is to provide a heat-generating structure and a heat-generating device that can improve the stability and controllability of heat generation by a heat generating element. [Means for solving the problem]

[0008] The heat generating structure of the present invention comprises a silicon substrate and a heat generating element that generates heat by absorbing and releasing hydrogen, the heat generating element having a support provided on the silicon substrate and a multilayer film provided on the support, the support being formed of at least one of a porous body, a hydrogen permeable film, and a proton conductor, the multilayer film having a first layer less than 1000 nm in thickness formed of a hydrogen storage metal or a hydrogen storage alloy, and a second layer less than 1000 nm in thickness formed of a hydrogen storage metal, hydrogen storage alloy or ceramic different from the first layer.

[0009] The heat generating device according to the present invention comprises the above-mentioned heat generating structure, a sealed container that houses the heat generating structure, a supply section that supplies a hydrogen-based gas containing the hydrogen to the inside of the sealed container, and an exhaust section that exhausts the hydrogen-based gas from inside the sealed container. Effect of the Invention

[0010] According to the present invention, a support is provided on a silicon substrate, and a multilayer film is provided on the support, thereby forming a smooth interface between different materials, thereby providing a heating structure and a heating device that can improve the stability and controllability of heat generation by the heating element. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is an explanatory diagram illustrating a configuration of a heat generating device according to the present embodiment. [Diagram 2] 1 is an explanatory diagram illustrating a configuration of a heat generating structure according to an embodiment of the present invention. [Diagram 3] FIG. 2 is a cross-sectional view showing the structure of a heating element. [Figure 4] FIG. 2 is a cross-sectional view showing the structure of a laminate having a first layer and a second layer. [Diagram 5] FIG. 1 is an explanatory diagram for explaining generation of excess heat. [Figure 6] FIG. 11 is an explanatory diagram for explaining a heating element of a first modified example having a first layer, a second layer, and a third layer. [Figure 7]FIG. 13 is an explanatory diagram for explaining a heating element of a second modified example having a first layer, a second layer, a third layer, and a fourth layer. [Figure 8] FIG. 4 is an explanatory diagram for explaining a heating method. [Figure 9] FIG. 2 is an explanatory diagram illustrating a state in which crystallites of a ternary alloy are formed. [Figure 10] 1A and 1B are explanatory diagrams for explaining the alteration and reduction of an interface between different materials; [Figure 11] 13 is an explanatory diagram illustrating a configuration of a heat generating device according to another embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description and drawings, common components are designated by common reference numerals. Descriptions of components designated by common reference numerals will be omitted as appropriate.

[0013] (heating device) 1 is an explanatory diagram illustrating the configuration of a heat generating device 1 according to this embodiment. In FIG. 1, the heat generating device 1 includes a heat generating structure 2, a sealed container 3, a supply unit 4, a discharge unit 5, a vacuum exhaust unit 6, a control unit 7, and a support mechanism 8.

[0014] The sealed container 3 is a hollow container composed of an upper portion 3a, a bottom portion 3b, and a side portion 3c. At least one of the upper portion 3a and the bottom portion 3b of the sealed container 3 is configured to be detachable from the side portion 3c, and the sealed container 3 is sealed by attaching the upper portion 3a and the bottom portion 3b to the side portion 3c. The sealed container 3 is provided with a pressure sensor (not shown) that detects the pressure inside the sealed container 3. The sealed container 3 is made of a material having heat resistance and pressure resistance such as carbon steel, austenitic stainless steel, heat-resistant non-ferrous alloy steel, or a material that reflects radiant heat such as Ni, Cu, Mo, etc. The shape of the sealed container 3 is not particularly limited, and may be a cylindrical shape, an elliptical cylindrical shape, a square cylindrical shape, or the like.

[0015] A hydrogen-based gas is introduced into the sealed container 3. The hydrogen-based gas is a gas containing hydrogen isotopes. As the hydrogen-based gas, heavy hydrogen gas, light hydrogen gas, heavy hydrogen gas, or a mixture of light hydrogen gas and an inert gas is used. Light hydrogen gas includes a mixture of naturally occurring light hydrogen and deuterium, that is, a mixture in which the abundance ratio of light hydrogen is 99.985% and the abundance ratio of deuterium is 0.015%. In the following description, when there is no need to distinguish between light hydrogen and deuterium, they are written as "hydrogen" or "H2". As the inert gas, for example, Ar gas, N2 gas, He gas, Ne gas, etc. are used.

[0016] The supply unit 4 has a pipe 4a connected to the sealed container 3 and an on-off valve 4b provided on the pipe 4a. Although not shown, the supply unit 4 further has a tank for storing the hydrogen-based gas, a pump for sending the hydrogen-based gas in the tank to the sealed container 3, a pressure sensor for detecting the pressure inside the pipe 4a, and the like. The on-off valve 4b is a pressure regulating valve configured to open and close according to the pressure inside the pipe 4a.

[0017] The exhaust unit 5 has a pipe 5a connected to the sealed container 3 and an on-off valve 5b provided on the pipe 5a. The exhaust unit 5 functions as a safety mechanism for preventing the sealed container 3 from being destroyed when excessive heat is generated and the pressure inside the sealed container 3 rises excessively. Although not shown, the exhaust unit 5 further has a pump for exhausting the hydrogen-based gas inside the sealed container 3, a pressure sensor for detecting the pressure inside the pipe 5a, and the like. The on-off valve 5b is a pressure regulating valve configured to open and close according to the pressure inside the pipe 5a.

[0018] The vacuum exhaust unit 6 has a pipe 6a connected to the sealed container 3, and an on-off valve 6b provided on the pipe 6a. Although not shown, the vacuum exhaust unit 6 further has a pump that evacuates the inside of the sealed container 3, a pressure sensor that detects the pressure inside the pipe 6a, and the like. The on-off valve 6b is a pressure regulating valve configured to open and close according to the pressure inside the pipe 6a.

[0019] The control unit 7 mainly includes, for example, a central processing unit, a storage unit such as a read only memory or a random access memory, etc. The computing unit executes various types of arithmetic processing using, for example, programs and data stored in the storage unit.

[0020] The control unit 7 controls the operations of the supply unit 4, exhaust unit 5, and vacuum exhaust unit 6 of the heat generating device 1. The control unit 7 is electrically connected to a pressure sensor and on-off valve 4b provided in the piping 4a of the supply unit 4, and controls the opening and closing of the on-off valve 4b based on the pressure detected by the pressure sensor. The control unit 7 is electrically connected to a pressure sensor and on-off valve 5b provided in the piping 5a of the exhaust unit 5, and controls the opening and closing of the on-off valve 5b based on the pressure detected by the pressure sensor. The control unit 7 is electrically connected to a pressure sensor and on-off valve 6b provided in the piping 6a of the vacuum exhaust unit 6, and controls the opening and closing of the on-off valve 6b based on the pressure detected by the pressure sensor.

[0021] The control unit 7 is electrically connected to the heater 15 and temperature sensor 16 described below, and controls the output of the heater 15 based on the temperature detected by the temperature sensor 16. The control unit 7 controls the output of the heater 15 to adjust the temperature of the heating element 14 and maintain the heating element 14 at an optimum temperature for heat generation (for example, 300°C to 1000°C).

[0022] The support mechanism 8 is provided inside the sealed container 3 and supports the heat generating structure 2. The support mechanism 8 has a mounting portion 8a on which the heat generating structure 2 is mounted, and a support portion 8b that fixes the mounting portion 8a to the sealed container 3. The support mechanism 8 has, for example, four support portions 8b protruding from the bottom of the mounting portion 8a, and these four support portions 8b are fixed to the bottom portion 3b of the sealed container 3.

[0023] (heat generating structure) Fig. 2 is an explanatory diagram illustrating the configuration of the heat generating structure 2 according to this embodiment. As shown in Fig. 2, the heat generating structure 2 includes a silicon substrate 13, a heat generating element 14, a heater 15, and a temperature sensor 16. In this embodiment, the heat generating structure 2 has a configuration in which the silicon substrate 13, the heat generating element 14, the heater 15, and the temperature sensor 16 are unitized. The heat generating structure 2 is configured to be detachably attached to the installation portion 8a of the support mechanism 8.

[0024] The silicon substrate 13 is used as a base for the heating element 14. The silicon substrate 13 has a smooth surface, on which the heating element 14 is provided. The surface roughness of the smooth surface of the silicon substrate 13 is preferably 10 nm or less, and more preferably 1 nm or less. The surface roughness can be calculated, for example, based on the arithmetic mean roughness Ra defined in the Japanese Industrial Standard JIS B 0601:2013. The thickness of the silicon substrate 13 is not particularly limited, but is, for example, 1 mm or less.

[0025] The silicon substrate 13 is a single crystal silicon wafer having a silicon oxide film 13a. As the single crystal silicon wafer having the silicon oxide film 13a, for example, a disc-shaped commercially available product is used. The thickness of the silicon substrate 13 is not particularly limited, but is, for example, 1 mm or less. The thickness of the silicon oxide film 13a is not particularly limited, but is, for example, 3 nm to 100 nm. The silicon substrate 13 is not limited to a single crystal silicon wafer having the silicon oxide film 13a, and may be, for example, a single crystal silicon wafer without a silicon oxide film.

[0026] The purity of the silicon substrate 13 is preferably 99.99999% or higher, and more preferably 99.999999999 or higher.

[0027] Heat generating element 14 generates heat by absorbing and releasing hydrogen. Heat generating element 14 has a support 61 provided on silicon substrate 13 and a multilayer film 62 provided on support 61. The detailed configuration of heat generating element 14 will be described later with reference to another drawing.

[0028] The heater 15 heats the heating element 14. The heater 15 increases in temperature in response to the power supplied thereto. A power source that supplies power to the heater 15 is provided in, for example, the control unit 7. In this embodiment, the heater 15 is a plate-shaped ceramic heater having a configuration in which a conductor is provided inside a base body formed of ceramics.

[0029] The temperature sensor 16 detects the temperature of the heating element 14. In this embodiment, the temperature sensor 16 is a thermocouple built into the heater 15, and is configured to detect the temperature of the heating element 14 via the heater 15.

[0030] (heating element) Next, a detailed structure of the heating element 14 will be described with reference to Figures 3 and 4. As shown in Figure 3, the heating element 14 has a laminate 14a having a support 61 and a multilayer film 62.

[0031] The support 61 may have any structure that allows the hydrogen-based gas to be absorbed in the heating element 14 and released from the heating element 14, and is formed of at least one of a porous body, a hydrogen-permeable membrane, and a proton conductor. In this example, the support 61 is formed in a plate shape having a front surface and a back surface. The porous body has holes of a size that allows the hydrogen-based gas to pass through. The porous body is formed of, for example, a metal, a nonmetal, or a ceramic. It is preferable that the porous body is formed of a material that does not inhibit the reaction between the hydrogen-based gas and the multilayer film 62 (hereinafter referred to as the exothermic reaction). The hydrogen-permeable membrane is formed of, for example, a hydrogen storage metal or a hydrogen storage alloy. Examples of the hydrogen storage metal include Ni, Pd, V, Nb, Ta, and Ti. Examples of the hydrogen storage alloy include LaNi5, Ca5Cu, Mg2Zn, ZrNi2, ZrCr2, TiFe, TiCo, Mg2Ni, and Mg2Cu. The hydrogen-permeable membrane includes a membrane having a mesh-like sheet. As proton conductors, BaCeO3-based (e.g. Ba(Ce 0.95 Y 0.05 )O 3-δ ), SrCeO3 system (e.g. Sr(Ce 0.95 Y 0.05 )O 3-δ), CaZrO3 system (e.g. CaZr 0.95 Y 0.05 O 3-α ), SrZrO3 series (e.g. SrZr 0.9 Y 0.1 O 3-α ), β Al2O3, β Ga2O3, etc. are used.

[0032] As shown in FIG. 4, the multilayer film 62 is provided on the support 61. The multilayer film 62 is formed of a first layer 71 formed of a hydrogen storage metal or a hydrogen storage alloy, and a second layer 72 formed of a hydrogen storage metal, a hydrogen storage alloy, or a ceramic different from the first layer 71. A different material interface 73 described later is formed between the first layer 71 and the second layer 72. In FIG. 4, the multilayer film 62 is formed by alternately stacking the first layer 71 and the second layer 72 in this order on one side (for example, the front side) of the support 61. The first layer 71 and the second layer 72 each have five layers. The number of layers of the first layer 71 and the second layer 72 may be changed as appropriate. The multilayer film 62 may be formed by alternately stacking the second layer 72 and the first layer 71 in this order on the front side of the support 61. The multilayer film 62 may have one or more first layers 71 and one or more second layers 72, and may have one or more dissimilar material interfaces 73. When the first layer 71 and the second layer 72 are alternately stacked in this order on the surface of the support 61 as shown in Fig. 2, the dissimilar material interface 73 is also formed between the first layer 71 and the support 61. Although not shown, when the second layer 72 and the first layer 71 are alternately stacked in this order on the surface of the support 61, the dissimilar material interface 73 is also formed between the second layer 72 and the support 61.

[0033] The first layer 71 is formed of, for example, any one of Ti, V, Ni, Pd, Cu, Mn, Cr, Fe, Mg, Co, Ca, Zr, Nb, Mo, Ta, or an alloy thereof. The alloy forming the first layer 71 is preferably an alloy consisting of two or more of Ti, V, Ni, Pd, Cu, Mn, Cr, Fe, Mg, Co, Ca, Zr, Nb, Mo, and Ta. The alloy forming the first layer 71 may be an alloy in which an additive element is added to Ti, V, Ni, Pd, Cu, Mn, Cr, Fe, Mg, Co, Ca, Zr, Nb, Mo, or Ta.

[0034] The second layer 72 is formed of, for example, any of Ti, V, Ni, Pd, Cu, Mn, Cr, Fe, Mg, Co, Ca, Zr, Nb, Mo, Ta, alloys thereof, and SiC. The alloy forming the second layer 72 is preferably an alloy consisting of two or more of Ti, V, Ni, Pd, Cu, Mn, Cr, Fe, Mg, Co, Ca, Zr, Nb, Mo, and Ta. The alloy forming the second layer 72 may be an alloy in which an additive element is added to Ti, V, Ni, Pd, Cu, Mn, Cr, Fe, Mg, Co, Ca, Zr, Nb, Mo, or Ta.

[0035] As a combination of the first layer 71 and the second layer 72, when the types of elements are expressed as "first layer 71-second layer 72 (second layer 72-first layer 71)", it is preferable that the combination is Pd-Ni, Ni-Cu, Ni-Cr, Ni-Fe, Ni-Mg, Ni-Co, or Ni-Ca. When the second layer 72 is made of ceramics, it is preferable that the "first layer 71-second layer 72" is Ni-SiC.

[0036] As shown in FIG. 5, the dissimilar material interface 73 allows hydrogen atoms to pass through. FIG. 5 is a schematic diagram showing how hydrogen atoms in the metal lattice of the first layer 71 pass through the dissimilar material interface 73 and move into the metal lattice of the second layer 72 in the first layer 71 and the second layer 72 formed of a hydrogen-storing metal with a face-centered cubic structure. It is known that hydrogen is light and quantum-diffuses while hopping between sites (octohedral or tetrahedral sites) occupied by hydrogen in a certain material A and a certain material B. For this reason, hydrogen absorbed in the heating element 14 quantum-diffuses while hopping inside the multilayer film 62. In the heating element 14, hydrogen passes through the first layer 71, the dissimilar material interface 73, and the second layer 72 by quantum diffusion.

[0037] The thickness of the first layer 71 and the thickness of the second layer 72 are preferably less than 1000 nm. If the thickness of each of the first layer 71 and the second layer 72 is 1000 nm or more, hydrogen is less likely to permeate the multilayer film 62. Furthermore, by making the thickness of each of the first layer 71 and the second layer 72 less than 1000 nm, a nanostructure that does not exhibit bulk characteristics can be maintained. It is more preferable that the thickness of each of the first layer 71 and the second layer 72 is less than 500 nm. By making the thickness of each of the first layer 71 and the second layer 72 less than 500 nm, a nanostructure that does not exhibit bulk characteristics at all can be maintained.

[0038] Next, an example of a method for manufacturing the heating element 14 will be described. In this case, a plate-shaped support 61 is prepared, and a vapor deposition apparatus is used to convert the hydrogen storage metal or alloy to be the first layer 71 and the second layer 72 into a gas phase state, and the first layer 71 and the second layer 72 are alternately formed on the surface of the support 61 by aggregation or adsorption. This forms a laminate 14a having a multilayer film 62 on the surface of the support 61. It is preferable that the first layer 71 and the second layer 72 are continuously formed in a vacuum state. This forms only a different material interface 73 between the first layer 71 and the second layer 72 without forming a natural oxide film. As the vapor deposition apparatus, a physical vapor deposition apparatus that vapor deposits the hydrogen storage metal or the hydrogen storage alloy by a physical method is used. As the physical vapor deposition apparatus, a sputtering apparatus, a vacuum vapor deposition apparatus, or a CVD (Chemical Vapor Deposition) apparatus is preferable. Alternatively, the hydrogen storage metal or the hydrogen storage alloy may be precipitated on the surface of the support 61 by an electroplating method, and the first layer 71 and the second layer 72 may be alternately formed.

[0039] As described above, the heating element 14 is provided on the smooth surface of the silicon substrate 13 serving as a base. Therefore, by forming the support 61 on the smooth surface of the silicon substrate 13 and forming the multilayer film 62 on the support 61, a smooth interface 73 between different materials can be formed.

[0040] The support 61 functions as a hydrogen storage layer that stores hydrogen. The thickness of the support 61 is predetermined according to the thickness of the multilayer film 62. The thickness of the support 61 is approximately the same as or slightly larger than the thickness of the multilayer film 62. Specifically, when the thickness of the support 61 is T1 and the thickness of the multilayer film 62 is T2, T1 / T2 is preferably 0.1 or more and 2.0 or less, and more preferably 0.2 or more and 1.0 or less.

[0041] In this embodiment, the support 61 is made of Pd. The support 61 has a thickness of 20 nm. The multilayer film 62 is composed of a first layer 71 made of Cu and a second layer 72 made of Ni. The first layer 71 and the second layer 72 each have six layers. The first layer 71 has a thickness of 2 nm. The second layer 72 has a thickness of 14 nm.

[0042] Although the heat generating device 1 includes a heat generating element 14 in this embodiment, the heat generating device 1 may include a heat generating element having a different configuration from the heat generating element 14. A first modified example will be described with reference to Fig. 6, and a second modified example will be described with reference to Fig. 7.

[0043] [First Modification] The heating device 1 includes a heating element 75 shown in FIG. 6 instead of the heating element 14. In the heating element 75 shown in FIG. 6, the multilayer film 62 of the laminate further includes a third layer 77 in addition to the first layer 71 and the second layer 72. The third layer 77 is formed of a hydrogen storage metal, a hydrogen storage alloy, or a ceramic different from the first layer 71 and the second layer 72. The thickness of the third layer 77 is preferably less than 1000 nm. In FIG. 6, the first layer 71, the second layer 72, and the third layer 77 are laminated on the surface of the support 61 in the order of the first layer 71, the second layer 72, the first layer 71, and the third layer 77. Note that the first layer 71, the second layer 72, and the third layer 77 may be laminated on the surface of the support 61 in the order of the first layer 71, the third layer 77, the first layer 71, and the second layer 72. That is, the multilayer film 62 has a laminated structure in which the first layer 71 is provided between the second layer 72 and the third layer 77. The multilayer film 62 only needs to have one or more third layers 77. A dissimilar material interface 78 formed between the first layer 71 and the third layer 77 allows hydrogen atoms to pass through, similar to the dissimilar material interface 73.

[0044] The third layer 77 is formed of, for example, any one of Ti, V, Ni, Pd, Cu, Cr, Fe, Mg, Co, Ca, Zr, Nb, Mo, Ta, alloys thereof, SiC, CaO, Y2O3, TiC, LaB6, SrO, and BaO. The alloy forming the third layer 77 is preferably an alloy consisting of two or more of Ti, V, Ni, Pd, Cu, Cr, Fe, Mg, Co, Ca, Zr, Nb, Mo, and Ta. The alloy forming the third layer 77 may be an alloy in which an additive element is added to Ti, V, Ni, Pd, Cu, Cr, Fe, Mg, Co, Ca, Zr, Nb, Mo, or Ta.

[0045] In particular, the third layer 77 is preferably formed of any one of CaO, Y2O3, TiC, LaB6, SrO, and BaO. The heating element 75 having the third layer 77 formed of any one of CaO, Y2O3, TiC, LaB6, SrO, and BaO has an increased hydrogen storage amount, and the amount of hydrogen permeating the dissimilar material interface 73 and the dissimilar material interface 78 is increased, thereby achieving high output of excess heat. The third layer 77 formed of any one of CaO, Y2O3, TiC, LaB6, SrO, and BaO is preferably 10 nm or less in thickness. This allows the multilayer film 62 to easily permeate hydrogen atoms. The third layer 77 formed of any one of CaO, Y2O3, TiC, LaB6, SrO, and BaO may be formed in an island shape rather than in a complete film shape. In addition, the first layer 71 and the third layer 77 are preferably formed successively in a vacuum state. As a result, no native oxide film is formed between the first layer 71 and the third layer 77, and only a different material interface 78 is formed.

[0046] Combinations of the first layer 71, the second layer 72, and the third layer 77, when the types of elements are expressed as "first layer 71-third layer 77-second layer 72", are as follows: Pd-CaO-Ni, Pd-Y2O3-Ni, Pd-TiC-Ni, Pd-LaB6-Ni, Ni-CaO-Cu, Ni-Y2O3-Cu, Ni-TiC-Cu, Ni-LaB6-Cu, Ni-Co-Cu, Ni-CaO-Cr, Ni-Y2O3-Cr, Ni-TiC-Cr, Ni-LaB6- Cr, Ni-CaO-Fe, Ni-Y2O3-Fe, Ni-TiC-Fe, Ni-LaB6-Fe, Ni-Cr-Fe, Ni-CaO-Mg, Ni-Y2O3-Mg, Ni-TiC-Mg, Ni-LaB6-Mg, N Preferred are i-CaO-Co, Ni-Y2O3-Co, Ni-TiC-Co, Ni-LaB6-Co, Ni-CaO-SiC, Ni-Y2O3-SiC, Ni-TiC-SiC, and Ni-LaB6-SiC.

[0047] The heating element 75 is provided on the smooth surface of the silicon substrate 13 serving as a base, similar to the heating element 14. For this reason, by forming the support 61 on the smooth surface of the silicon substrate 13 and forming the multilayer film 62 on the support 61, it is possible to form smooth dissimilar material interfaces 73 and 78.

[0048] [Second modified example] The heating device 1 includes a heating element 80 shown in FIG. 7 instead of the heating element 14. In the heating element 80 shown in FIG. 7, the multilayer film 62 of the laminate further includes a fourth layer 82 in addition to the first layer 71, the second layer 72, and the third layer 77. The fourth layer 82 is formed of a hydrogen storage metal, a hydrogen storage alloy, or a ceramic different from the first layer 71, the second layer 72, and the third layer 77. The thickness of the fourth layer 82 is preferably less than 1000 nm. In FIG. 7, the first layer 71, the second layer 72, the third layer 77, and the fourth layer 82 are laminated on the surface of the support 61 in the order of the first layer 71, the second layer 72, the first layer 71, the third layer 77, the first layer 71, and the fourth layer 82. The first layer 71, the second layer 72, the third layer 77, and the fourth layer 82 may be laminated on the surface of the support 61 in the order of the first layer 71, the fourth layer 82, the first layer 71, the third layer 77, the first layer 71, and the second layer 72. That is, the multilayer film 62 has a laminated structure in which the second layer 72, the third layer 77, and the fourth layer 82 are laminated in any order, and the first layer 71 is provided between each of the second layer 72, the third layer 77, and the fourth layer 82. The multilayer film 62 may have one or more fourth layers 82. The dissimilar material interface 83 formed between the first layer 71 and the fourth layer 82 allows hydrogen atoms to pass through, similar to the dissimilar material interface 73 and the dissimilar material interface 78.

[0049] The fourth layer 82 is formed of, for example, any one of Ti, V, Ni, Pd, Cu, Cr, Fe, Mg, Co, Ca, Zr, Nb, Mo, Ta, alloys thereof, SiC, CaO, Y2O3, TiC, LaB6, SrO, and BaO. The alloy forming the fourth layer 82 is preferably an alloy consisting of two or more of Ti, V, Ni, Pd, Cu, Cr, Fe, Mg, Co, Ca, Zr, Nb, Mo, and Ta. The alloy forming the fourth layer 82 may be an alloy in which an additive element is added to Ti, V, Ni, Pd, Cu, Cr, Fe, Mg, Co, Ca, Zr, Nb, Mo, or Ta.

[0050] In particular, the fourth layer 82 is preferably formed of any one of CaO, Y2O3, TiC, LaB6, SrO, and BaO. The heating element 80 having the fourth layer 82 formed of any one of CaO, Y2O3, TiC, LaB6, SrO, and BaO has an increased hydrogen storage amount, and the amount of hydrogen permeating the dissimilar material interface 73, the dissimilar material interface 78, and the dissimilar material interface 83 is increased, thereby achieving high output of excess heat. The fourth layer 82 formed of any one of CaO, Y2O3, TiC, LaB6, SrO, and BaO is preferably 10 nm or less in thickness. This allows the multilayer film 62 to easily permeate hydrogen atoms. The fourth layer 82 formed of any one of CaO, Y2O3, TiC, LaB6, SrO, and BaO may be formed in an island shape rather than in a complete film shape. In addition, the first layer 71 and the fourth layer 82 are preferably formed successively in a vacuum state. As a result, no native oxide film is formed between the first layer 71 and the fourth layer 82, and only a different material interface 83 is formed.

[0051] As for the combination of the first layer 71, the second layer 72, the third layer 77, and the fourth layer 82, when the types of elements are expressed as "first layer 71-fourth layer 82-third layer 77-second layer 72", it is preferable that the combination is Ni-CaO-Cr-Fe, Ni-Y2O3-Cr-Fe, Ni-TiC-Cr-Fe, or Ni-LaB6-Cr-Fe.

[0052] Similar to the heating element 14, the heating element 80 is provided on the smooth surface of the silicon substrate 13 serving as a base. For this reason, by forming the support 61 on the smooth surface of the silicon substrate 13 and forming the multilayer film 62 on the support 61, it is possible to form smooth dissimilar material interfaces 73, 78, and 83.

[0053] The heating element having multiple layers may be a mixture of two or more of heating element 14 shown in Fig. 4, heating element 75 shown in Fig. 6, and heating element 80 shown in Fig. 7. Heating elements having multiple layer configurations may be arranged in any order. The configuration of multilayer film 62, for example, the ratio of thicknesses of each layer, the number of layers, and materials, may be appropriately changed depending on the temperature to be used.

[0054] (Action and Effects) In the heat generating device 1 configured as above, the sealed container 3 is opened, and the heat generating structure 2 is placed on the installation portion 8a of the support mechanism 8 provided inside the sealed container 3. The sealed container 3 is sealed, and the pump of the vacuum exhaust portion 6 is driven to evacuate the inside of the sealed container 3. The heater 15 is driven to heat the heat generating element 14. For example, the temperature of the heat generating element 14 is raised to about 200° C. by the heater 15, thereby removing moisture from the heat generating element 14.

[0055] The output of the heater 15 is increased, and the heating element 14 is further heated. For example, the temperature of the heating element 14 is set to about 300° C. by the heater 15. The pump of the supply unit 4 is driven, and the hydrogen-based gas stored in a tank (not shown) flows through the pipe 4a and is introduced into the sealed container 3. As a result, hydrogen is absorbed into the support 61 and the multilayer film 62 of the heating element 14. For example, a mixed gas containing H2 and Ar (3% H2 / Ar gas) is used as the hydrogen-based gas. After the heating element 14 absorbs hydrogen, the supply unit 4 is stopped. The output of the heater 15 is controlled, and the temperature of the heating element 14 is set to an arbitrary temperature (for example, about 700° C.) within the range of temperatures optimal for heat generation, and the heating element 14 is heated. As the heating element 14 is heated, the pump of the vacuum exhaust unit 6 is driven, and the hydrogen-based gas inside the sealed container 3 flows through the pipe 6a and is discharged. This puts the heating element 14 in a state in which it generates heat (hereinafter referred to as a heat generating state). That is, hydrogen absorbed in the support 61 and the multilayer film 62 of the heating element 14 permeates the dissimilar material interface 73 by quantum diffusion, or hydrogen diffuses through the dissimilar material interface 73 by quantum diffusion, generating excess heat in the heating element 14.

[0056] When the vacuum exhaust unit 6 continues to evacuate, the hydrogen absorbed in the heating element 14 is gradually released (discharged). For this reason, when the heating element 14 is to continue to generate heat for a long period of time, the operation of the vacuum exhaust unit 6 is stopped, and the supply unit 4 is driven to introduce hydrogen-based gas into the sealed container 3, causing the heating element 14 to absorb (supply) hydrogen. For example, the hydrogen-based gas is gradually introduced until the inside of the sealed container 3 reaches 1 atm. At this time, the output of the heater 15 is controlled to maintain the temperature of the heating element 14 within a temperature range optimal for heat generation. After the heating element 14 absorbs hydrogen, the operation of the supply unit 4 is stopped and the vacuum exhaust unit 6 is driven, allowing the heating element 14 to continue to generate heat.

[0057] FIG. 8 is an explanatory diagram for explaining the heating method. In FIG. 8, the heater 15 and the temperature sensor 16 of the heating structure 2 are omitted. When a hydrogen-based gas is introduced into the sealed container 3, a hydrogen molecule is adsorbed on the surface (the surface opposite to the support 61) of the multilayer film 62 of the heating element 14, and the hydrogen molecule is dissociated into two hydrogen atoms. Then, the dissociated hydrogen atoms penetrate (occlude) into the multilayer film 62 and the support 61. At this time, the hydrogen atoms that penetrate into the multilayer film 62 and the support 61 do not penetrate into the silicon substrate 13. When the hydrogen-based gas in the sealed container 3 is discharged, the hydrogen atoms that penetrate into the multilayer film 62 and the support 61 return to the surface of the multilayer film 62, recombine, and are released as hydrogen molecules. As a result, hydrogen atoms pass through the dissimilar material interface 73 (see FIG. 5) by quantum diffusion, or hydrogen atoms diffuse through the dissimilar material interface 73 by quantum diffusion, causing the temperature of the heating element 14 to rise to a temperature equal to or higher than the heating temperature by the heater 15, thereby generating excess heat.

[0058] According to the heating structure 2 of this embodiment, the heating element 14 is provided on the silicon substrate 13 serving as a base, thereby forming a smooth interface 73 between different materials, thereby improving the stability and controllability of the heat generation by the heating element 14.

[0059] The heating structure 2 can be easily and inexpensively manufactured because a commercially available single crystal silicon wafer having a silicon oxide film 13a can be used as the silicon substrate 13. In addition, by using a large-diameter single crystal silicon wafer as the silicon substrate 13 and providing a large-diameter heating element 14 on its surface, high output can be achieved.

[0060] Since the purity of the silicon substrate 13 in the heating structure 2 is 99.99999% or more, contamination and alteration of the dissimilar material interface 73 caused by impurities contained in the silicon substrate 13 is suppressed, thereby further improving the stability and controllability of the heat generation by the heating element 14.

[0061] The heat generating structure 2 has a unitary configuration of a silicon substrate 13, a heat generating element 14, a heater 15, and a temperature sensor 16. Therefore, it is easy to increase or decrease the number of heat generating structures 2 to be installed in the heat generating device 1, and the degree of freedom in designing the heat generating device 1 can be improved.

[0062] According to the heat generating device 1 of the present embodiment, by including the heat generating structure 2 described above, it is possible to improve the stability and controllability of heat generation by the heat generating element 14.

[0063] In addition, in the heating device 1, when the temperature T of the heating element 14 reaches the critical temperature Tc, a chemical reaction or alloying reaction occurs between the metal constituting the first layer 71, the metal constituting the second layer 72, and the metal constituting the support 61, and crystallites of a ternary alloy with different alloy concentrations (alloy compositions) are formed. The critical temperature Tc is the temperature at which the metal constituting the support 61, the metal constituting the first layer 71, and the metal constituting the second layer 72 are alloyed, and is also called the alloying reaction start temperature. For example, if the first layer 71 is made of Cu, the second layer 72 is made of Ni, and the support 61 is made of Pd, the critical temperature Tc is 500°C, and when the temperature T of the heating element 14 reaches the critical temperature Tc (500°C), crystallites of a ternary alloy (Pd-Ni-Cu alloy) are formed.

[0064] FIG. 9 is an explanatory diagram for explaining the state in which the crystallites of the ternary alloy are formed. As shown in FIG. 9, when the condition of T=Tc is satisfied, in the heating element 14, the metal constituting the first layer 71, the metal constituting the second layer 72, and the metal constituting the support 61 are alloyed, and the crystallites 90 of the ternary alloy having different alloy concentrations are formed. In FIG. 9, the difference in the alloy concentration of the crystallites 90 is expressed by different types of hatching. A dissimilar material interface 91 different from the dissimilar material interface 73 is formed between the crystallites 90 of the ternary alloy having different alloy concentrations. Here, for convenience, the formation of the dissimilar material interface 91 different from the dissimilar material interface 73 is referred to as "alteration of the dissimilar material interface". Note that the silicon atoms constituting the silicon substrate 13 do not diffuse and penetrate into the support 61 or the multilayer film 62 (the first layer 71 and the second layer 72). In addition, since the silicon substrate 13 is high purity, the impurity elements in the silicon substrate 13 do not segregate into the support 61 or the multilayer film 62.

[0065] When the thickness of the support 61 is approximately the same as or slightly larger than the thickness of the multilayer film 62, after the ternary alloy crystallites 90 are formed, the metals constituting the support 61 do not further diffuse into the ternary alloy crystallites 90. Although the alloying reaction causes the interface of different substances to change, the decrease (also called dilution) of the interface of different substances is suppressed. In the heat generating device 1, although the interface of different substances changes, the interface of different substances 91 is formed, and hydrogen atoms can pass through the interface of different substances 91 by quantum diffusion, or hydrogen atoms can diffuse through the interface of different substances 91 by quantum diffusion, thereby generating excess heat in the heat generating body 14 that is equal to or higher than the heating temperature.

[0066] In this embodiment, the thickness of the support 61 is approximately the same as or slightly larger than the thickness of the multilayer film 62, but if the thickness of the support is, for example, three or more orders of magnitude thicker than the thickness of the multilayer film, when the temperature T of the heating element exceeds the critical temperature Tc, the alteration and reduction of the interface between the different materials may progress. Below, as a comparative example of the heating element, a case where the thickness of the support is, for example, three or more orders of magnitude thicker than the thickness of the multilayer film will be described.

[0067] The alteration and reduction of the interface between different materials will be explained using Figure 10. Figure 10(a) shows a state where the temperature T of the heating element is below the critical temperature Tc. Figure 10(b) shows a state where the temperature T of the heating element has reached the critical temperature Tc. Figure 10(c) shows a state where the temperature T of the heating element has exceeded the critical temperature Tc.

[0068] As shown in FIG. 10(a), the heating element 214 has a support 261 and a multilayer film 262 provided on the support 261. The multilayer film 262 has a first layer 271 and a second layer 272. A dissimilar material interface 273 is formed between the first layer 271 and the second layer 272. The thickness of the support 261 is, for example, three or more orders of magnitude thicker than the thickness of the multilayer film 262. In the state shown in FIG. 10(a), the dissimilar material interface 273 does not change in quality. Therefore, the heating element 214 can generate heat as designed.

[0069] As shown in FIG. 10(b), when the temperature T of the heating element 214 reaches the critical temperature Tc, the metal constituting the support 261, the metal constituting the first layer 271, and the metal constituting the second layer 272 are alloyed, and ternary alloy crystallites 290 with different alloy concentrations are formed. A dissimilar material interface 291 different from the dissimilar material interface 273 is formed between the ternary alloy crystallites 290 with different alloy concentrations. In other words, the dissimilar material interface is altered. In the state shown in FIG. 10(b), the dissimilar material interface 291 is formed as a result, and the heating element 214 can generate heat approximately as designed.

[0070] 10(c), when the temperature T of the heating element 214 exceeds the critical temperature Tc, the metal constituting the support 261 diffuses and penetrates into the ternary alloy crystallites 290. As a result, the number of crystallites in which the ratio of the metal constituting the support 261 is close to 100% increases, and the number of dissimilar substance interfaces 291 decreases. In the state shown in FIG. 10(c), the number of dissimilar substance interfaces 291 decreases, thereby suppressing heat generation in the heating element 214.

[0071] (Other embodiments) In the above-described embodiment, the heat generating device 1 including one heat generating structure 2 has been described, but the present invention is not limited to this.

[0072] 11 is an explanatory diagram illustrating the configuration of a heat generating device 100 according to another embodiment. The same reference numerals are used for components and members that are the same as or equivalent to those in the above embodiment. Explanations that overlap with the above embodiment will be omitted as appropriate, and the description will focus on the configuration that differs from the above embodiment.

[0073] 11, the heat generating device 100 includes three heat generating structures 2, a sealed container 3, a supply unit 4, a discharge unit 5, a vacuum exhaust unit 6, a control unit 7, and a support mechanism 108. The heater 15 and temperature sensor 16 of each heat generating structure 2 are electrically connected to the control unit 7. The control unit 7 controls the output of the heater 15 for each heat generating structure 2 based on the temperature detected by the temperature sensor 16. The heat generating device 100 includes three heat generating structures 2 in this embodiment, but is not limited to this and may include two or four or more heat generating structures 2.

[0074] The support mechanism 108 is provided inside the sealed container 3 and supports each of the heat generating structures 2. The support mechanism 108 has three mounting portions 108a on which the three heat generating structures 2 are respectively mounted, and a support portion 108b that fixes the three mounting portions 108a to the sealed container 3. The three mounting portions 108a are disposed at different heights and fixed to the support portion 108b. The support portion 108b is fixed to the top 3a and bottom 3b of the sealed container 3.

[0075] As in the above-described embodiment, the heat generating device 100 includes the heat generating structure 2, thereby improving the stability and controllability of heat generation by the heat generating element 14. Furthermore, the heat generating device 100 includes a plurality of heat generating structures 2, thereby achieving high output.

[0076] The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

[0077] In the above embodiment, the heat generating structure 2 has a configuration in which the silicon substrate 13, the heat generating element 14, the heater 15, and the temperature sensor 16 are unitized, but the present invention is not limited to this. The heat generating structure 2 may be any structure that includes the silicon substrate 13 and the heat generating element 14. For example, in the heat generating device 1, the heater 15 and the temperature sensor 16 may be provided on the installation portion 8a of the support mechanism 8, and the heat generating structure 2 including the silicon substrate 13 and the heat generating element 14 may be detachably attached to the heater 15. In this case, for example, when replacing the heat generating structure 2 with another heat generating structure, it is possible to replace only the heat generating structure 2 while leaving the heater 15 and the temperature sensor 16 provided on the installation portion 8a of the support mechanism 8.

[0078] Although the hydrogen storage metal has a face-centered cubic crystal structure in FIG. 5, the crystal structure is not limited to the face-centered cubic structure, and may have a body-centered cubic structure or the like.

[0079] When the thickness of the support 61 is T1 and the thickness of the multilayer film 62 is T2, T1 / T2 is preferably 0.1 or more and 5.0 or less, and more preferably 0.2 or more and 3.0 or less. [Explanation of symbols]

[0080] 1 Heating device 2 Heat generating structure 3. Airtight containers 4 Supply section 4a Piping 4b On-off valve 5 Discharge section 5a Piping 5b On-off valve 6 Vacuum exhaust section 6a Piping 6b On-off valve 7 Control section 8 Support mechanism 8a Installation part 8b Support column 13 Silicon substrate 13a Silicon oxide film 14 Heating element 14a Laminate 15 Heater 16 Temperature Sensor 61 Support 62 Multilayer film 71 1st layer 72 2nd layer 73 Different materials interface 75 Heating element 77 3rd layer 78 Different materials interface 80 Heating element 82 4th layer 83 Different materials interface 100 Heating device 108 Support mechanism 108a Installation part 108b Support section

Claims

1. A silicon substrate; A heating element that generates heat by absorbing and releasing hydrogen; Equipped with the heating element includes a support provided on the silicon substrate and a multilayer film provided on the support, the support is formed of at least one of a porous body, a hydrogen-permeable membrane, and a proton conductor; the multilayer film has a first layer formed of a hydrogen storage metal or a hydrogen storage alloy, and a second layer formed of a hydrogen storage metal, a hydrogen storage alloy, or a ceramic different from that of the first layer, the first layer is less than 1000 nm thick; The heat generating structure wherein the second layer is less than 1000 nm thick.

2. 2. The heat generating structure according to claim 1, wherein the silicon substrate is a single crystal silicon wafer having a silicon oxide film.

3. 2. The heat generating structure according to claim 1, wherein the purity of the silicon substrate is 99.99999% or more.

4. A heater that heats the heating element; A temperature sensor for detecting the temperature of the heating element; The heat generating structure according to claim 1 .

5. A heat generating structure according to any one of claims 1 to 4, A sealed container for storing the heat generating structure; a supply unit for supplying a hydrogen-based gas containing hydrogen into the sealed container; an exhaust section for exhausting the hydrogen-based gas from inside the sealed container; A heating device comprising:

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