Heating structure and heating device

Abstract

Provided are a heating structure and a heating device capable of efficiently raising the temperature of a heating element. A heating structure 8 includes: a heating element 14 having a support body, in which Joule heat is generated by the flow of current, and a multilayer film, which is provided on the support body and generates heat by the occlusion and release of hydrogen; and a pair of electrode parts 15 provided on the support body and connected to a current source 19. The multilayer film has a first layer formed of a hydrogen-occluding metal or a hydrogen-occluding alloy and having a thickness of less than 1000 nm, and a second layer formed of a ceramic or a different hydrogen-occluding metal or hydrogen-occluding alloy than the first layer and having a thickness of less than 1000 nm. The support body generates heat when a current is applied from the current source 19 through the pair of electrode parts 15, and heats the multilayer film.

Description

Heat-generating structure and heat-generating device

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

[0002] Recently, a heating device has been proposed that includes a sealed container to which hydrogen-containing gas is supplied and a heating structure having a heating element that generates heat by absorbing and releasing hydrogen (see Patent Document 1). The heating structure is housed in the sealed container. The heating element includes a base formed of a hydrogen storage metal, a hydrogen storage alloy, or a proton conductor, and a multilayer film provided on the base. The multilayer film includes a first layer formed of a hydrogen storage metal or a hydrogen storage alloy and having a thickness of less than 1000 nm, and a second layer formed 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. An interface of different materials is formed between the first and second layers. The heating device of Patent Document 1 includes a cylindrical heater as an example of a means for heating the heating element, and the heating element is disposed in the space inside the heater. In the heat generating device of Patent Document 1, after hydrogen is absorbed into the heat generating element, the inside of the sealed container is evacuated and the heat generating element is heated, causing the hydrogen to permeate the interface of different materials in the heat generating element by quantum diffusion, or the hydrogen to diffuse the interface of different materials by quantum diffusion, generating excess heat.

[0003] Japanese Patent Application Laid-Open No. 2021-107744

[0004] However, in the heating device of Patent Document 1, the heater is configured to heat not only the inner space but also the outer space, so energy loss occurs when heating the heating element located inside the heater, and it takes time for the heating element to reach an optimum temperature for heat generation. Therefore, it is desirable to efficiently raise the temperature of the heating element.

[0005] An object of the present invention is to provide a heat generating structure and a heat generating device that can efficiently increase the temperature of a heat generating element.

[0006] The heat-generating structure of the present invention comprises a support that generates Joule heat when an electric current flows through it, a heat generating element having a multilayer film provided on the support that generates heat by absorbing and releasing hydrogen, and a pair of electrode portions provided on the support and connected to a current source, the multilayer film having a first layer less than 1000 nm thick and made of a hydrogen-absorbing metal or hydrogen-absorbing alloy, and a second layer less than 1000 nm thick and made of a hydrogen-absorbing metal, hydrogen-absorbing alloy or ceramic different from the first layer, the support generates heat when an electric current is applied from the current source via the pair of electrode portions, thereby heating the multilayer film.

[0007] 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 unit that supplies a hydrogen-based gas containing hydrogen into the sealed container, an exhaust unit that exhausts the hydrogen-based gas from the sealed container, and a current source connected to the pair of electrode units.

[0008] According to the present invention, the temperature of the heating element can be increased efficiently.

[0009] FIG. 1 is a conceptual diagram showing the configuration of a heat utilization system according to a first embodiment; FIG. 2 is a cross-sectional view showing the configuration of a heating element formed in a band shape; FIG. 3 is an explanatory diagram for explaining an example of a method for manufacturing a heating element; FIG. 4 is a cross-sectional view showing the configuration of a heating element formed in a line shape; FIG. 5 is a top view of a heating structure having a configuration in which heating elements are arranged in a spiral shape on the surface of a plate-shaped insulator; FIG. 6 is a side view of a heating structure having a configuration in which heating elements are arranged in a spiral shape on the surface of a plate-shaped insulator; FIG. 7 is a conceptual diagram showing the configuration of a heat utilization system according to a second embodiment; FIG. 8 is a conceptual diagram showing the configuration of a heat utilization system according to a third embodiment; FIG. 9 is a conceptual diagram showing the configuration of a heat utilization system according to a fourth embodiment.

[0010] 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.

[0011] (1) Heat Utilization System According to the First Embodiment In Fig. 1, the heat utilization system 1 includes a piping path 2 through which a heat medium flows, a heat generating device 3 that heats the heat medium flowing through the piping path 2, and a heat utilization device 4 that uses the heat medium heated by the heat generating device 3 as a heat source. The heat generating device 3 and the heat utilization device 4 are incorporated into the piping path 2. The piping path 2 forms a sealed circulation path between the heat generating device 3 and the heat utilization device 4.

[0012] The heat transfer medium may be a gas or a liquid, and is preferably one that has excellent thermal conductivity and is chemically stable. Examples of the gas that can be used include helium gas, argon gas, hydrogen gas, nitrogen gas, water vapor, air, and carbon dioxide. Examples of the liquid that can be used include water and molten salt (KNO ３ (40%)-NaNO ３ (60%)), liquid metal (Pb, etc.), etc. may be used. Alternatively, a multiphase heat transfer medium in which solid particles are dispersed in a gas or liquid may be used as the heat transfer medium. The solid particles may be metals, metal compounds, alloys, ceramics, etc. Metals may include Cu, Ni, Ti, Co, etc. Metal compounds may include oxides, nitrides, silicides, etc. of the above metals. Alloys may include stainless steel, chromium molybdenum steel, etc. Ceramics may include alumina, etc. In this embodiment, helium gas is used as the heat transfer medium, but this may be changed as appropriate within the scope of the present invention.

[0013] The heat generating device 3 comprises a hollow sealed container 5 , a hydrogen tank 6 connected to the sealed container 5 , a vacuum pump 7 connected to the sealed container 5 , and a heat generating structure 8 housed in the sealed container 5 .

[0014] The sealed container 5 is heat-resistant and pressure-resistant. The sealed container 5 is made of, for example, stainless steel, heat-resistant non-ferrous alloy steel, or the like. A material appropriate for the operating temperature is used for the sealed container 5. For example, stainless steel is used when the operating temperature is up to about 700°C, and heat-resistant non-ferrous alloy steel is used when the operating temperature exceeds 700°C. The sealed container 5 is cylindrical. The sealed container 5 is composed of a body, an upper lid attached to the upper end of the body, and a lower lid attached to the lower end of the body. The upper end of the body is airtightly closed with the upper lid, and the lower end of the body is airtightly closed with the lower lid, thereby defining a space 9 inside the sealed container 5. The shape of the sealed container 5 is not limited to a cylindrical shape, and may be an elliptical cylinder, a rectangular cylinder, a sphere, or the like. In the heating device 3, the upper lid side of the sealed container 5 is referred to as the upper side, and the lower lid side of the sealed container 5 is referred to as the lower side.

[0015] The heat generating device 3 has an inlet pipe 10 that connects the sealed container 5 and the hydrogen tank 6, and an exhaust pipe 11 that connects the sealed container 5 and the vacuum pump 7. The inlet pipe 10 extends from the bottom lid of the sealed container 5 and is connected to the hydrogen tank 6, forming an inlet path that guides the hydrogen-based gas stored in the hydrogen tank 6 to the internal space 9 of the sealed container 5. The exhaust pipe 11 extends from the top lid of the sealed container 5 and is connected to the vacuum pump 7, forming an exhaust path that guides the hydrogen-based gas sucked into the vacuum pump 7 from the internal space 9 of the sealed container 5.

[0016] The inlet pipe 10 has a supply valve 12 provided between the sealed container 5 and the hydrogen tank 6. The supply valve 12 adjusts the flow rate of the hydrogen-based gas flowing through the inlet pipe 10. For example, an electromagnetic valve or an air valve is used as the supply valve 12. The inlet pipe 10 may have a pressure sensor that detects the pressure of the hydrogen-based gas flowing through the inlet pipe 10.

[0017] The exhaust pipe 11 has an exhaust valve 13 provided between the sealed container 5 and the vacuum pump 7. The exhaust valve 13 adjusts the flow rate of the hydrogen-based gas flowing through the exhaust pipe 11. For example, an electromagnetic valve or an air valve is used as the exhaust valve 13. The exhaust pipe 11 may have a pressure sensor that detects the pressure of the hydrogen-based gas flowing through the exhaust pipe 11.

[0018] When the exhaust valve 13 is closed and the supply valve 12 is opened, it becomes possible to supply hydrogen-based gas from the hydrogen tank 6 to the space 9 inside the sealed container 5. When the supply valve 12 is closed and the exhaust valve 13 is opened, it becomes possible to exhaust the hydrogen-based gas from the space 9 inside the sealed container 5 by the vacuum pump 7.

[0019] The hydrogen tank 6 stores a hydrogen-based gas. In this example, when the supply valve 12 is opened, the hydrogen-based gas is supplied from the high-pressure hydrogen tank 6 to the internal space 9 of the low-pressure sealed container 5 via the inlet pipe 10. The hydrogen-based gas is a gas containing hydrogen isotopes. At least one of deuterium gas and protium gas is used as the hydrogen-based gas. The protium gas includes a mixture of naturally occurring protium and deuterium, i.e., a mixture in which the abundance ratio of protium is 99.985% and the abundance ratio of deuterium is 0.015%. The inlet pipe 10 may have a pump that sends the hydrogen-based gas stored in the hydrogen tank 6 to the internal space 9 of the sealed container 5.

[0020] The vacuum pump 7 exhausts the hydrogen-based gas from the inside of the sealed container 5 through the exhaust pipe 11. The space 9 inside the sealed container 5 is depressurized by driving the vacuum pump 7. The vacuum pump 7 is composed of, for example, a turbomolecular pump and a dry pump. The turbomolecular pump adjusts the rotation speed of the turbine blades based on a control signal input from a control unit 21, which will be described later. The speed at which the space 9 is depressurized is adjusted according to the rotation speed of the turbomolecular pump.

[0021] The heat generating structure 8 heats the heat medium flowing along the outer surface of the sealed container 5 through the sealed container 5. The temperature of the heat medium heated by the heat generating structure 8 reaches a range of, for example, 50°C to 1500°C. In this example, the temperature of the heat medium is set to 700°C.

[0022] The heating structure 8 includes a heating element 14 that generates heat by absorbing and releasing hydrogen, a pair of electrode portions 15 that are provided on the heating element 14 and electrically connected to a current source 19, an insulator 16 that supports the heating element 14, and a temperature sensor 17 that detects the temperature of the heating element 14.

[0023] The heating element 14 is a flexible, elongated member. The heating element 14 is formed in a strip shape. The heating element 14 is spirally wound around the outer peripheral surface of a cylindrical insulator 16 (described later). The spiral shape refers to a shape that is wound around an axis and extends continuously along the axial direction. The spiral shape includes a circular wound shape, an elliptical wound shape, a polygonal wound shape, and the like. In FIG. 1 , one end of the heating element 14 is disposed on the lower end side of the body of the sealed container 5, and the other end of the heating element 14 is disposed on the upper end side of the body of the sealed container 5. A pair of electrodes 15 is provided on both ends of the heating element 14. The configuration of the heating element 14 will be described later.

[0024] The pair of electrode units 15 are provided on a support 61 of the heating element 14, which will be described later. The pair of electrode units 15 are connected to conductive wires 18. The conductive wires 18 are connected to a current source 19, and electrically connect the pair of electrode units 15 and the current source 19. The current source 19 generates a current. Although the pair of electrode units 15 extend from the inside to the outside of the sealed container 5 in FIG. 1 , they may be housed inside the sealed container 5. For example, a pair of connection terminals may be provided on the upper and lower lids of the sealed container 5, the pair of connection terminals may be connected to the conductive wires 18, and the pair of electrode units 15 may be connected to the pair of connection terminals inside the sealed container 5.

[0025] The insulator 16 is formed in a hollow or solid cylindrical shape. In this embodiment, the insulator 16 is formed in a hollow cylindrical shape and has a uniform diameter throughout the entire axial length of the insulator 16. Note that "uniform" includes not only strictly uniform but also nearly uniform, i.e., variations within a range that does not deviate from the spirit of the invention (for example, variations within a tolerance range determined at the time of design). The shape of the insulator 16 is not limited to a cylindrical shape, and may be any other appropriate shape, such as an elliptical cylindrical shape, a rectangular cylindrical shape, or a spherical shape.

[0026] The insulator 16 is fixed to the inner wall surface of the sealed container 5 by a fixing member (not shown). The insulator 16 has the rigidity to support the heating element 14 and maintain the shape of the heating element 14. The insulator 16 is made of quartz or ceramics. Quartz and ceramics have rigidity and excellent heat resistance.

[0027] The temperature sensor 17 outputs a detection signal that specifies the detected temperature. The temperature sensor 17 has, for example, a thermocouple embedded in the heating element 14. The thermocouple outputs a voltage that specifies the detected temperature.

[0028] The heat generating device 3 includes a control unit 21 electrically connected to the vacuum pump 7, the supply valve 12, the exhaust valve 13, the temperature sensor 17, and the current source 19. The control unit 21 includes, for example, a microprocessor (MPU) that performs arithmetic processing based on an application program stored in a read-only memory (ROM) or other storage unit, and a random access memory (RAM) that temporarily stores programs and data during arithmetic processing.

[0029] The control unit 21 outputs control signals that control the operations of the vacuum pump 7, the supply valve 12, the exhaust valve 13, and the current source 19. The vacuum pump 7, the supply valve 12, the exhaust valve 13, and the current source 19 operate based on the control signals input from the control unit 21.

[0030] The control unit 21 closes the supply valve 12 , opens the exhaust valve 13 , and drives the vacuum pump 7 to exhaust (evacuate) the hydrogen-based gas from the space 9 inside the sealed container 5 .

[0031] The control unit 21 stops the operation of the vacuum pump 7 , closes the exhaust valve 13 , and opens the supply valve 12 , thereby supplying the hydrogen-based gas to the space 9 inside the sealed container 5 .

[0032] The control unit 21 controls the output of the current source 19 to adjust the magnitude of the current flowing from the current source 19 to the heating element 14 via the conductive wire 18 and the pair of electrodes 15. By controlling the output of the current source 19, the temperature of the heating element 14 is adjusted, and it becomes possible to maintain the heating element 14 within an optimum temperature range for heat generation (for example, 50°C to 1500°C).

[0033] In the heat generating device 3, the hydrogen tank 6, the inlet pipe 10, and the supply valve 12 constitute a supply section that supplies a hydrogen-based gas containing hydrogen into the sealed container 5. In the heat generating device 3, the vacuum pump 7, the exhaust pipe 11, and the exhaust valve 13 constitute an exhaust section that exhausts the hydrogen-based gas from the sealed container 5.

[0034] The heat utilization device 4 includes a containment vessel 41 that stores the sealed container 5 of the heat generation device 3, a first power generation unit 42 that generates power inside the containment vessel 41 using the heat medium (helium gas in this example) heated by the heat generation device 3, a pressure pump 43 that sends the heat medium from the first power generation unit 42 toward the containment vessel 41, and a flow control valve 44 provided between the pressure pump 43 and the containment vessel 41.

[0035] The containment vessel 41 has thermal insulation and pressure resistance. It is made of, for example, stainless steel, heat-resistant non-ferrous alloy steel, or the like. A material appropriate for the operating temperature is used for the containment vessel 41. For example, stainless steel is used when the operating temperature is up to about 700°C, and heat-resistant non-ferrous alloy steel is used when the operating temperature exceeds 700°C. The containment vessel 41 has an inlet 41a through which the heat medium flows and an outlet 41b through which the heat medium flows. The heat medium that flows into the containment vessel 41 from the inlet 41a flows along the outer surface of the sealed container 5 of the heat-generating device 3 housed inside the containment vessel 41 and is heated by the heat-generating structure 8 housed in the sealed container 5. The temperature of the heat medium rises inside the containment vessel 41, and a high-temperature heat medium is obtained. The high-temperature heat medium flows out of the outlet 41b of the containment vessel 41 and flows into the first power generation unit 42.

[0036] The first power generating unit 42 includes a compressor (not shown) that compresses the high-temperature heat medium supplied from the containment vessel 41, a gas turbine 42a that is driven by the high-temperature, high-pressure heat medium compressed by the compressor, and a generator 42b connected to the gas turbine 42a. In the first power generating unit 42, the temperature of the heat medium is adjusted to, for example, a range of 600°C to 1500°C. The output shaft of the gas turbine 42a is connected to the input shaft of the generator 42b. Rotation of the turbine blades of the gas turbine 42a drives the rotor of the generator 42b, which then generates electricity (power). The heat medium whose heat has been utilized in the first power generating unit 42 flows out of the first power generating unit 42 and into the pressure pump 43.

[0037] The pressure pump 43 sends the heat medium supplied from the first power generation unit 42 at a predetermined pressure toward the containment vessel 41. The pressure pump 43 is, for example, a metal bellows pump.

[0038] The flow control valve 44 adjusts the flow rate of the heat medium flowing from the pressure pump 43 toward the containment vessel 41. As the flow control valve 44, for example, a variable leak valve is used.

[0039] Next, the configuration of the heating element 14 will be described. FIG. 2 is a cross-sectional view showing the configuration of the heating element 14 formed in a band shape. As shown in FIG. 2, the heating element 14 includes a support 61 and a multilayer film 62 provided on the support 61. The multilayer film 62 includes a first layer 71 made of a hydrogen storage metal or a hydrogen storage alloy and having a thickness of less than 1000 nm, and a second layer 72 made of a hydrogen storage metal, a hydrogen storage alloy, or a ceramic different from the first layer 71 and having a thickness of less than 1000 nm. Interfaces 73 of different materials are formed between the first layer 71 and the second layer 72 and between the support 61 and the multilayer film 62. The interfaces 73 of different materials allow hydrogen atoms to pass through the interfaces 73 of different materials. The heating element 14 generates excess heat by hydrogen atoms passing through the interfaces 73 of different materials by quantum diffusion or by hydrogen atoms diffusing through the interfaces 73 of different materials by quantum diffusion. The multilayer film 62 is a multilayer film disclosed in International Publication WO2018 / 230447, International Publication WO2020 / 122097, International Publication WO2020 / 122098, etc. The detailed configuration, function, and manufacturing method of the multilayer film 62 are the same as those disclosed in International Publication WO2018 / 230447, International Publication WO2020 / 122097, International Publication WO2020 / 122098, etc., and therefore will not be described here.

[0040] The support 61 is formed in a strip shape. The support 61 has a rectangular cross section. The dimensions of the support 61 are, for example, 2423.5 mm in length, 5 mm in width, and 0.02 mm in thickness. Note that the support 61 is not limited to having a rectangular cross section, and may have an elliptical or polygonal cross section.

[0041] The support 61 is connected to the pair of electrode portions 15. A current flows in one direction between the pair of electrode portions 15 in the support 61. The support 61 has a uniform electrical resistance in the direction in which the current flows. The support 61 has a uniform cross-sectional area in the direction in which the current flows. The support 61 generates heat when a current is applied from the current source 19 via the pair of electrode portions 15, thereby heating the multilayer film 62. The support 61 functions as a resistance heating heater.

[0042] The support 61 generates Joule heat when a current flows through it. Examples of materials that can be used for the support 61 include Ni, Mo, Cu, Au, Pd, Fe, Co, Pt, Os, Cr, V, Ti, W, and alloys thereof (e.g., SUS304 and NCF600). The support 61 may be made of at least one of a hydrogen storage metal, a hydrogen storage alloy, and a proton conductor. Examples of hydrogen storage metals that can be used include Ni, Pd, V, Nb, Ta, and Ti. Examples of hydrogen storage alloys include LaNi. ５ , CaCu ５ , MgZn ２ , ZrNi ２ , ZrCr ２ , TiFe, TiCo, Mg ２ Ni, Mg ２ Cu is used as the proton conductor. BaCeO ３ system (e.g., Ba(Ce ０．９５ Y ０．０５ )O ３－６ ), SrCeO ３ System (e.g., Sr(Ce ０．９５ Y ０．０５ )O ３－６ ), CaZrO ３ system (e.g., CaZr ０．９５ Y ０．０５ O ３－α ), SrZrO ３ system (e.g., SrZr ０．９ Y ０．１ O ３－α） , β Al ２ O ３ , β Ga ２ O ３ The support 61 may be formed of a porous body or a hydrogen-permeable membrane. The porous body has pores of a size that allows hydrogen-based gas to pass through. The porous body is formed of, for example, a metal, a non-metal, or a ceramic. The porous body is preferably formed of a material that does not inhibit the reaction between the hydrogen-based gas and the multilayer film 62. The hydrogen-permeable membrane is formed of, for example, a hydrogen-storing metal or a hydrogen-storing alloy. The hydrogen-permeable membrane includes a membrane having a mesh-like sheet.

[0043] In FIG. 2, the multilayer film 62 is configured to be laminated on one surface (e.g., the front surface) of the support 61, but this is not limited thereto, and the multilayer film 62 may be configured to be laminated on the other surface (e.g., the back surface) of the support 61, or the multilayer film 62 may be configured to be laminated on both surfaces (the front surface and the back surface) of the support 61.

[0044] An example of a manufacturing method for the heating element 14 will be described. First, a large foil-shaped support 61 is prepared. Next, using a vapor deposition apparatus, a hydrogen-storing metal or alloy that will become the first layer 71 and the second layer 72 is converted into a gas phase, and the first layer 71 and the second layer 72 are alternately deposited on the surface of the support 61 by aggregation and adsorption. This results in a multilayer film 62 on the surface of the support 61. The first layer 71 and the second layer 72 are preferably deposited consecutively in a vacuum. This results in only a dissimilar material interface 73 being formed between the first layer 71 and the second layer 72, without any native oxide film being formed. A physical vapor deposition apparatus that physically deposits the hydrogen-storing metal or hydrogen-storing alloy is used as the vapor deposition apparatus. Examples of the physical vapor deposition apparatus include a sputtering apparatus, a vacuum deposition apparatus, and a CVD (Chemical Vapor Deposition) apparatus. Alternatively, the first layer 71 and the second layer 72 may be alternately deposited by electroplating the hydrogen-storing metal or hydrogen-storing alloy on the surface of the support 61.

[0045] Next, as shown in FIG. 3 , the support 61 and the multilayer film 62 are cut into strips. This results in the heating element 14 as a flexible, elongated member. In FIG. 3 , the heating element 14 has a plurality of parallel portions 74a extending parallel to one another, a first folded portion 74b connecting and folding back one ends of adjacent parallel portions 74a, and a second folded portion 74c connecting and folding back the other ends of adjacent parallel portions 74a. The plurality of parallel portions 74a are folded back at the first folded portions 74b and the second folded portions 74c, forming a single continuous body extending in a zigzag pattern. The first folded portions 74b and the second folded portions 74c are rounded so that the cross-sectional areas of the parallel portions 74a, the first folded portions 74b, and the second folded portions 74c are the same. In addition, "same" includes not only being strictly the same, but also being almost the same, i.e., being different within the scope of the invention without departing from the spirit of the invention (for example, being different within the tolerance range determined at the time of design).

[0046] A pair of electrodes 15 are connected to both ends of the support 61 of the heating element 14, and the heating element 14 is spirally wound around the outer circumferential surface of the insulator 16, thereby producing the heating structure 8.

[0047] The operation and effects of the heating device 3 according to this embodiment will be described. First, the sealed container 5 is opened, the heating structure 8 is placed inside the sealed container 5, and the sealed container 5 is sealed. The pair of electrodes 15 of the heating structure 8 are connected to the current source 19 via the conductive wires 18. The exhaust valve 13 is opened, and the vacuum pump 7 is driven. The space 9 inside the sealed container 5 is evacuated. The vacuum pump 7 is stopped, the exhaust valve 13 is closed, and the current source 19 is driven. A current is applied from the current source 19 to the support 61 of the heating element 14 via the conductive wires 18 and the pair of electrodes 15. The support 61 generates Joule heat as a result of the current flow. The heat generated by the support 61 heats the multilayer film 62 provided on the support 61. In this manner, the temperature of the heating element 14 rises. For example, by raising the temperature of the heating element 14 to approximately 200°C, moisture can be removed from the heating element 14.

[0048] Next, the output of the current source 19 is increased, further increasing the temperature of the heating element 14. For example, the temperature of the heating element 14 is set to about 300°C. The supply valve 12 is opened. Hydrogen-based gas flows from the hydrogen tank 6 into the space 9 inside the sealed container 5. The space 9 inside the sealed container 5 is filled with the hydrogen-based gas. The heating element 14 absorbs hydrogen. Specifically, a hydrogen molecule in the space 9 is adsorbed onto the surface of the multilayer film 62 of the heating element 14 (the surface opposite the support 61), and this hydrogen molecule dissociates into two hydrogen atoms. The dissociated hydrogen atoms then penetrate (absorb) into the interior of the multilayer film 62.

[0049] After hydrogen is absorbed into the heating element 14, the supply valve 12 is closed. The output of the current source 19 is controlled to set the temperature of the heating element 14 to a desired temperature (e.g., approximately 700°C) within the optimum temperature range for heat generation. At this time, the exhaust valve 13 is opened and the vacuum pump 7 is driven. Hydrogen-based gas is exhausted from the space 9 inside the sealed container 5. The heating element 14 releases hydrogen. Specifically, hydrogen atoms that have penetrated into the interior of the multilayer film 62 return to the surface of the multilayer film 62, recombine, and are released as hydrogen molecules. As a result, the hydrogen atoms pass through the dissimilar material interface 73 by quantum diffusion, or the hydrogen atoms diffuse through the dissimilar material interface 73 by quantum diffusion, generating excess heat in the heating element 14.

[0050] In the heating structure 8, the support 61 is connected to a pair of electrodes 15, and when a current is applied from the current source 19 to the support 61 via the pair of electrodes 15, the support 61 generates heat, thereby heating the multilayer film 62. Because the multilayer film 62 is formed on the support 61, the heat of the support 61 is efficiently transferred to the multilayer film 62. Because the support 61 and the multilayer film 62 are integrally configured, the heat capacity of the multilayer film 62 can be designed to be small, allowing the multilayer film 62 to be heated quickly. Therefore, the heating structure 8 can efficiently increase the temperature of the heating element 14.

[0051] The heating device 3 applies a current to the support 61, causing the support 61 to generate heat, which heats the multilayer film 62 and can raise the temperature of the heating element 14 to a desired temperature in a short time, eliminating the need for a separate heater such as an electric furnace, thereby reducing manufacturing costs and power consumption. When a separate heater is used to heat the heating element, a complex design is required to efficiently transfer the heat from the separate heater to the heating element, but the heating device 3 allows the support 61, which is configured integrally with the multilayer film 62, to function as a heater, thereby simplifying the design.

[0052] The support 61 has a uniform electrical resistance in the direction in which the current flows. When a current flows through the support 61 between the pair of electrode parts 15, the heat generated is uniform throughout the direction in which the current flows. The multilayer film 62 provided on the support 61 is uniformly heated by the support 61. Since the temperature of the heating element 14 is uniform, the heat generation of the heating element 14 is well controlled.

[0053] The support 61 has a uniform cross-sectional area in the direction of current flow. The uniform cross-sectional area contributes to establishing uniform electrical resistance in the support 61. Since the electrical resistance varies depending on the size of the cross-sectional area of ​​the support 61, the electrical resistance of the support 61 can be well controlled.

[0054] The heating element 14 is flexible. The support 61 and the multilayer film 62 deform integrally. The shape of the multilayer film 62 can be changed in accordance with changes in the shape of the support 61, which improves the degree of freedom in designing the heating element 14.

[0055] The heating element 14 is an elongated member, and by adjusting the length of the heating element 14, the excess heat output can be controlled.

[0056] The heating elements 14 are spirally wound around the outer circumferential surface of a cylindrical insulator 16. When winding the heating elements 14 around the insulator 16, the spacing between adjacent heating elements 14 is adjusted, and the density of the heating elements 14 in the insulator 16 is adjusted, thereby controlling the output of excess heat.

[0057] The insulator 16 supports the heating element 14 and maintains the spiral shape of the heating element 14. The insulator 16 is made of quartz or ceramics. Quartz or ceramics has rigidity and excellent heat resistance, so even if the heating element 14 reaches a high temperature, the insulator 16 can favorably support the heating element 14 without being damaged.

[0058] Here, the results of a trial calculation of the power required to raise the temperature of the support 61 to a desired temperature (referred to as the target temperature) in a preset time (referred to as the set time) will be explained. The power P was calculated as the sum of the amount of heat Q1 (also referred to as the heat radiation amount) from the surface of the support 61 at the target temperature T and the amount of heat Q2 required to raise the temperature of the support 61 to the target temperature T in the set time t. The support 61 used was a strip of Ni foil with a length of 2423.5 mm, a width of 5 mm, and a thickness of 0.02 mm. The surface area A of the Ni foil was 12214.512 mm. ２ The volume V of the Ni foil is 242.35 mm ３ (0.00024235 L). The set time t was 0.17 h (10 min). The target temperature T of the Ni foil was 800 ° C. The initial temperature T of the Ni foil ０ The target temperature T was set to -85°C. ０ The temperature difference ΔT obtained by subtracting this is 885°C.

[0059] First, the amount of heat Q1 radiated from the surface of the support 61 (Ni foil) at the target temperature T (800° C.) was calculated using the following formula (1): Q1=σ×ε×T ４ × A (1) where σ is the Stefan-Boltzmann constant, ε is the total emissivity of the surface of the Ni foil, T is the target temperature, and A is the surface area of ​​the Ni foil. Note that in equation (1), the target temperature T is an absolute temperature.

[0060] The Stefan-Boltzmann constant σ is 5.67 × 10 －８ W / (m ２ ・K ４ The total emissivity ε of the surface of the Ni foil was 0.2. The target temperature T was 1073 K. The surface area A of the Ni foil was 12214.512 mm ２Therefore, the amount of heat dissipation Q1 from the surface of the Ni foil at 1073 K is calculated to be 183.6 W from the above formula (1).

[0061] Next, the amount of heat Q2 required to raise the temperature of the support 61 (Ni foil) to the target temperature T (800°C) in a set time t (0.17 h) was calculated using the following formula (2): Q2 = (0.2778 x c x ρ x V x ΔT / t) x α (2) where c is the specific heat of Ni, ρ is the density of Ni, V is the volume of the Ni foil, and ΔT is the ratio between the target temperature T and the initial temperature T of the Ni foil. ０ is the temperature difference between the temperature of the target object and the temperature of the target object, t is the set time, and α is the safety factor taking into account manufacturing errors, etc.

[0062] The specific heat c of Ni was set to 0.44 kJ / (kg·°C). The density ρ of Ni was set to 8.9 kg / L. The volume V of the Ni foil was 0.000242 L. The temperature difference ΔT was 885°C. The set time t was 0.17 h. The safety factor α was set to 1.25. Therefore, the amount of heat Q2 required to raise the temperature of the Ni foil to 800°C in 0.17 h was calculated to be 1.75 W using the above formula (2).

[0063] As described above, the heat quantity Q1 due to radiation from the surface of the support 61 at 800°C is 183.6 W, and the heat quantity Q2 required to raise the temperature of the support 61 to 800°C in 0.17 h is 1.75 W, so the power P required to raise the temperature of the support 61 to 800°C in 0.17 h is estimated to be 185.4 W.

[0064] The operation and effects of the heat utilization system 1 according to this embodiment will now be described. In the piping path 2, helium gas as a heat medium flows into the containment vessel 41 by the pressure pump 43. In the containment vessel 41, heat is transferred from the heat generating device 3 to the helium gas, causing the temperature of the helium gas to rise. The high-temperature helium gas flowing out of the containment vessel 41 flows into the compressor (not shown) of the first power generation unit 42. The high-temperature, high-pressure helium gas flowing out of the compressor flows into the gas turbine 42a and rotates the turbine blades of the gas turbine 42a. The rotation of the turbine blades is transferred to the rotor of the generator 42b. Electric power is generated in the generator 42b.

[0065] The thermal energy of the helium gas is consumed to rotate the turbine blades of the gas turbine 42a. As the temperature of the helium gas decreases in the gas turbine 42a, the pressure also decreases. The helium gas flowing out of the gas turbine 42a is sucked into the pressure pump 43. The pressure pump 43 sends the helium gas toward the containment vessel 41. Power generation continues as the helium gas circulates.

[0066] As described above, the heat utilization system 1 uses, as a heat source, a heat medium heated by a heat generating device 3 equipped with a heating element 14 that generates heat by absorbing and releasing hydrogen, and therefore can supply energy cheaply, cleanly, and safely.

[0067] The heating device 3 is not limited to having one heating structure 8, but may be one that includes multiple heating structures 8. The heating structure 8 is not limited to having one heating element 14, but may be one that includes multiple heating elements 14. The heating element 14 is not limited to being wound spirally around the outer circumferential surface of the insulator 16, but may be attached spirally along the inner circumferential surface of the insulator 16.

[0068] The heating structure 8 may include a linear heating element 90 as shown in FIG. 4 instead of the band-shaped heating element 14. FIG. 4 is a cross-sectional view showing the configuration of the linear heating element 90. While the heating element 90 in FIG. 4 has a circular cross section, the cross section is not limited thereto and may have a polygonal cross section. The heating element 90 is a flexible, elongated member. The heating element 90 is wound spirally around the outer peripheral surface of the insulator 16. A pair of electrodes 15 is provided on both ends of the heating element 90. The pair of electrodes 15 is electrically connected to a current source 19 via conductive wires 18.

[0069] The heating element 90 includes a support 91 and a multilayer film 92. The support 91 is formed in a linear shape. While the support 91 has a circular cross section in FIG. 4, the cross section is not limited to this and may have a polygonal cross section. The dimensions of the support 91 are, for example, 2423.5 mm in length and 0.5 mm in diameter.

[0070] The support 91 is connected to a pair of electrode units 15. A current flows in one direction between the pair of electrode units 15 in the support 91. The support 91 has a uniform electrical resistance in the direction in which the current flows. The support 91 has a uniform cross-sectional area in the direction in which the current flows. The outer peripheral surface of the support 91 is covered with a multilayer film 92. When a current is applied from the current source 19 via the pair of electrode units 15, the support 91 generates heat, heating the multilayer film 92. The support 91 has the same configuration and function as the support 61 described above.

[0071] The multilayer film 92 is provided on a support 91. The multilayer film 92 is preferably formed continuously on the outer peripheral surface of the support 91. The multilayer film 92 is formed in a cylindrical shape. Although the multilayer film 92 has a circular cross section in FIG. 4, the cross section is not limited to this and may have a polygonal cross section. The multilayer film 92 has the same configuration and function as the multilayer film 62 described above. That is, the multilayer film 92 has a first layer 71 and a second layer 72. The first layer 71 and the second layer 72 are not shown in FIG. 4.

[0072] In the heating element 90, similar to the heating element 14, dissimilar material interfaces 73 are formed between the first layer 71 and the second layer 72 and between the support 91 and the multilayer film 92. In FIG. 4 , the dissimilar material interface 73 formed between the support 91 and the multilayer film 92 is illustrated, but the dissimilar material interface 73 formed between the first layer 71 and the second layer 72 is not illustrated. In the heating element 90, hydrogen atoms pass through the dissimilar material interface 73 by quantum diffusion, or hydrogen atoms diffuse through the dissimilar material interface 73 by quantum diffusion, thereby generating excess heat. The heating element 90 has a function similar to that of the heating element 14.

[0073] An example of a manufacturing method for the heating element 90 will be described. First, a linear support 91 is prepared. Next, similar to the manufacturing method for the heating element 14, first layers 71 and second layers 72 are alternately formed on the surface of the support 91. This forms a multilayer film 92 on the surface of the support 91, thereby obtaining the heating element 90. Alternatively, the heating element 90 can be obtained by preparing a large foil-shaped support 91, forming the multilayer film 92 on the surface of the support 91, and cutting the support 91 and the multilayer film 92 into a linear shape.

[0074] The heating device 3 is not limited to a heating structure 8 having a configuration in which the heating element 14 is wound spirally around the outer peripheral surface of a cylindrical insulator 16, but may also have a heating structure 98 having a configuration in which the heating element 94 is arranged in a spiral shape on the surface of a plate-shaped insulator 96, as shown in FIG. 5 . FIG. 5 is a top view of a heating structure 98 having a configuration in which the heating element 94 is arranged in a spiral shape on the surface of the plate-shaped insulator 96. FIG. 6 is a side view of a heating structure 98 having a configuration in which the heating element 94 is arranged in a spiral shape on the surface of the plate-shaped insulator 96. The term "spiral shape" refers to a shape that extends continuously while winding from the center toward the outside or from the outside toward the center. The spiral shape includes a circular wound shape, an elliptical wound shape, a polygonal wound shape, and the like.

[0075] The heating structure 98 includes a plurality of heating elements 94, a pair of electrodes 95 provided on the respective supports 61 of the plurality of heating elements 94 and electrically connected to the current source 19, a plurality of insulators 96 supporting the plurality of heating elements 94, and a temperature sensor 17 (not shown) for detecting the temperature of the plurality of heating elements 94. In this example, the heating elements 94 have the same configuration as the heating element 14. That is, the heating element 94 includes the support 61 that generates Joule heat when a current flows through it, and a multilayer film 62 that is provided on the support 61 and generates heat by absorbing and releasing hydrogen. Note that the heating element 94 is not limited to having the same configuration as the heating element 14, and may have the same configuration as the heating element 90.

[0076] In the heating structure 98, the supports 61 of each of the multiple heating elements 94 are connected to a pair of electrode portions 95, and when a current is applied from the current source 19 to each support 61 via the pair of electrode portions 95, each support 61 generates heat, thereby heating each multilayer film 62. In Fig. 6, the heating structure 98 includes 15 heating elements 94 and insulators 96, but is not limited to this and may include one or more heating elements 94 and insulators 96.

[0077] The plurality of heating elements 94 are arranged at intervals in the vertical direction (see FIG. 6). In this example, the plurality of heating elements 94 each have the same configuration. Below, the configuration of the heating element 94 will be described using the uppermost heating element 94 shown in FIG. 5 as a representative example of the plurality of heating elements 94 arranged in the vertical direction.

[0078] The heating element 94 is a flexible, elongated member. The heating element 94 is formed in a strip shape. The heating element 94 has one end 94a in the longitudinal direction, another end 94b opposite the one end 94a in the longitudinal direction, and a center 94c between the one end 94a and the other end 94b. The length between the one end 94a and the center 94c is the same as the length between the other end 94b and the center 94c. In FIG. 5 , the heating element 94 has one end 94a and the other end 94b arranged symmetrically with respect to the center 94c, and extends in a spiral shape clockwise from the center 94c toward the one end 94a and from the center 94c toward the other end 94b. In other words, the heating element 94 extends counterclockwise in a spiral shape from one end 94a toward the center 94c, turns back at the center 94c, and then extends clockwise in a spiral shape from the center 94c toward the other end 94b.

[0079] The pair of electrode portions 95 are formed in a hollow or solid cylindrical shape. In this example, the pair of electrode portions 95 are formed in a solid cylindrical shape. The pair of electrode portions 95 extend in the vertical direction. The pair of electrode portions 95 are connected to conductive wires 18 (not shown). The conductive wires 18 are connected to a current source 19 (not shown) and electrically connect the pair of electrode portions 95 to the current source 19. For example, the upper end of each of the pair of electrode portions 95 is connected to the conductive wires 18, and the lower end of each of the pair of electrode portions 95 is fixed to the bottom lid of the sealed container 5 by a fixing member (not shown). In this example, a male thread is formed on the outer circumferential surface of each of the pair of electrode portions 95. The pair of electrode portions 95 is not limited to being cylindrical, and may be formed in any other appropriate shape, such as an elliptical cylindrical shape, a rectangular cylindrical shape, or a spherical shape.

[0080] The insulators 96 are arranged at intervals in the vertical direction (see FIG. 6 ). In this example, the insulators 96 each have the same configuration. The configuration of the insulator 96 will be described below using the topmost insulator 96 shown in FIG. 5 as a representative example of the insulators 96 arranged in the vertical direction.

[0081] The insulator 96 is formed in a plate shape. In Fig. 5, the insulator 96 is formed in a circular shape. A pair of through holes is formed in the insulator 96. A pair of electrode portions 95 are inserted into the pair of through holes. The shape of the insulator 96 is not limited to a circular shape, and may be any other appropriate shape, such as an elliptical shape or a polygonal shape.

[0082] The insulator 96 has the rigidity to support the heating element 94 and maintain the shape of the heating element 94. The insulator 96 is made of quartz or ceramics. Quartz and ceramics have rigidity and excellent heat resistance.

[0083] The insulators 96 are fixed to the pair of electrode portions 95 by fastening members 97 (see FIG. 6 ). The fastening members 97 are provided so as to contact the surfaces of the insulators 96. Of the multiple insulators 96 arranged vertically, the lowest insulator 96 is provided with a fastening member 97 so as to contact its surface and a fastening member 97 so as to contact its back surface. In this example, the fastening member 97 is a nut with a female thread formed on its inner circumferential surface. The female thread formed on the inner circumferential surface of the fastening member 97 screws into a male thread formed on the outer circumferential surface of the electrode portion 95.

[0084] The fastening member 97 is made of a conductive material such as metal or an insulating material such as ceramic. When the fastening member 97 is made of a conductive material, the support 61 of the heating element 94 and the electrode portion 95 may be electrically connected via the fastening member 97. When the fastening member 97 is made of an insulating material, the support 61 of the heating element 94 and the electrode portion 95 are directly connected.

[0085] Of the multiple insulators 96 arranged vertically, spacers 99 are provided between adjacent insulators 96. In Fig. 6, of the insulators 96 arranged vertically adjacent to each other, the spacer 99 is provided so as to come into contact with the back surface of the upper insulator 96. The spacer 99 is made of an insulating material such as ceramics.

[0086] An example of a manufacturing method for the heating element 94 will be described. First, similar to the manufacturing method for the heating element 14, a large foil-shaped support 61 is prepared, and first layers 71 and second layers 72 are alternately formed on the surface of the support 61. Next, the support 61 and the multilayer film 62 are cut out into a spiral shape. This results in a spiral-shaped heating element 94. The heating element 94 has one end 94a in the longitudinal direction, another end 94b opposite the one end 94a in the longitudinal direction, and a center 94c between the one end 94a and the other end 94b. The one end 94a and the other end 94b are arranged symmetrically with respect to the center 94c. The heating element 94 is configured as a single continuous body that spirally extends clockwise from the center 94c toward the one end 94a and from the center 94c toward the other end 94b. Alternatively, a spiral heating element 94 can be obtained by preparing a large foil-shaped support 61, alternately depositing first layers 71 and second layers 72 on the surface of the support 61, cutting the support 61 and the multilayer film 62 into strips, and arranging them in a spiral on the surface of a plate-shaped insulator 96.

[0087] In the heating structure 98, the support 61 is connected to a pair of electrode portions 95, and when a current is applied from the current source 19 to the support 61 via the pair of electrode portions 95, the support 61 generates heat, thereby heating the multilayer film 62. Because the multilayer film 62 is formed on the support 61, the heat of the support 61 is efficiently transferred to the multilayer film 62. Because the support 61 and the multilayer film 62 are configured integrally, the heat capacity of the multilayer film 62 can be designed to be small, allowing the multilayer film 62 to be heated quickly. Therefore, the heating structure 98 can efficiently increase the temperature of the heating element 94.

[0088] The heating element 94 is flexible. The support 61 and the multilayer film 62 deform integrally. The shape of the multilayer film 62 can be changed in accordance with changes in the shape of the support 61, which improves the degree of freedom in designing the heating element 94.

[0089] The heating element 94 is an elongated member, and by adjusting the length of the heating element 94, the excess heat output can be controlled.

[0090] The heating elements 94 are arranged in a spiral on the surface of a plate-shaped insulator 96. By adjusting the spacing between adjacent heating elements 94 and adjusting the density of the heating elements 94 on the insulator 96, the output of excess heat can be controlled.

[0091] The insulator 96 supports the heating element 94 and maintains the spiral shape of the heating element 94. The insulator 96 is made of quartz or ceramics. Quartz or ceramics has rigidity and excellent heat resistance, so even if the heating element 94 reaches a high temperature, the insulator 96 can favorably support the heating element 94 without being damaged.

[0092] The one end 94a and the other end 94b of the heating element 94 are not limited to being arranged symmetrically with respect to the center 94c, but the positions of the one end 94a and the other end 94b can be changed.

[0093] The heating element 94 is not limited to a configuration in which it extends in a spiral shape clockwise from the center 94c toward the one end 94a and also from the center 94c toward the other end 94b, with the center 94c being the center. For example, the heating element 94 may have a configuration in which it extends in a spiral shape clockwise or counterclockwise from the one end 94a toward the other end 94b.

[0094] The heating structure 98 is not limited to a configuration in which the heating elements 94 are spirally arranged on the surface of the plate-shaped insulator 96, but may also have a configuration in which the heating elements 94 are spirally arranged on the back surface of the plate-shaped insulator 96. The heating structure 98 may also have a configuration in which one heating element 94 is spirally arranged on the surface of the plate-shaped insulator 96, and another heating element 94 is spirally arranged on the back surface of the plate-shaped insulator 96.

[0095] The heating structure 98 may have a heating element 90 instead of the heating element 94, and may have a configuration in which the heating element 90 is arranged in a spiral shape on at least one of the front and back surfaces of a plate-shaped insulator 96.

[0096] (2) Heat Utilization System According to the Second Embodiment Fig. 7 is a conceptual diagram showing the configuration of a heat utilization system 1a according to the second embodiment. The heat utilization system 1a includes a heat utilization device 4a instead of the heat utilization device 4 of the first embodiment. The heat utilization device 4a is incorporated into the piping path 2 together with the heat generating device 3. In the second embodiment, water is used as the heat medium. Note that components and members that are the same as or equivalent to those in the first embodiment are designated by the same reference numerals and will not be described again.

[0097] The heat utilization device 4a includes a boiler 101 that houses the sealed container 5 of the heat generation device 3, a second power generation unit 102 that generates power based on the gas phase heat medium supplied from the boiler 101, a condenser 103 that cools the gas phase heat medium supplied from the second power generation unit 102 to convert it into a liquid phase heat medium, and a water supply pump 104 that pressurizes the liquid phase heat medium supplied from the condenser 103 and sends it toward the boiler 101.

[0098] The boiler 101 houses a pipe 105 that functions as an evaporator. Water is supplied to the pipe 105 from a water supply pump 104. The pipe 105 is exposed to heat from the heat generating device 3. Heat is transferred from the sealed container 5 to the pipe 105. The boiler 101 generates high-temperature, high-pressure steam (gas-phase heat medium) inside the pipe 105. The high-temperature, high-pressure steam is supplied from the boiler 101 to the second power generation unit 102.

[0099] The second power generating unit 102 includes a steam turbine 102a driven by high-temperature, high-pressure steam supplied from the boiler 101, and a generator 102b connected to the steam turbine 102a. In the second power generating unit 102, the temperature of the steam is adjusted, for example, within a range of 300°C to 700°C. The output shaft of the steam turbine 102a is connected to the input shaft of the generator 102b. Rotation of the turbine blades of the steam turbine 102a drives the rotor of the generator 102b, which generates electricity. The steam after heat utilization is supplied from the second power generating unit 102 to a condenser 103.

[0100] The condenser 103 cools the steam supplied from the second power generation unit 102 using cooling water 103a to return it to water (a liquid-phase heat medium). The condenser 103 outputs low-pressure water. The low-pressure water is supplied from the condenser 103 to a feedwater pump 104. The feedwater pump 104 sends the water supplied from the condenser 103 to the boiler 101 at a predetermined pressure.

[0101] As described above, the heat utilization system 1a uses, as a heat source, a heat medium heated by a heat generating device 3 equipped with a heating element 14 that generates heat by absorbing and releasing hydrogen, and therefore can supply energy cheaply, cleanly, and safely.

[0102] Instead of water, the heat medium may be a substance that changes from a liquid phase to a gas phase in response to the heat of the heat generating device 3. It is preferable to use a substance that has excellent thermal conductivity and is chemically stable as the heat medium.

[0103] (3) Heat Utilization System According to the Third Embodiment Fig. 8 is a conceptual diagram showing the configuration of a heat utilization system 1b according to the third embodiment. The heat utilization system 1b includes a heat utilization device 4b instead of the heat utilization device 4 of the first embodiment. The heat utilization device 4b includes a Stirling engine 110 that receives heat from the heat-generating device 3 to drive it, and a generator 111 connected to the Stirling engine 110. Note that components and members that are the same as or equivalent to those in the above embodiments are designated by the same reference numerals, and descriptions thereof will be omitted.

[0104] The Stirling engine 110 includes a first cylinder 112 having a closed end at one end, an expansion piston 114 housed in the first cylinder 112 at a position facing the closed end and defining an expansion chamber 113 between itself and the closed end, a second cylinder 115 having a closed end at one end, a compression piston 117 housed in the second cylinder 115 at a position facing the closed end and defining a compression chamber 116 between itself and the closed end, a heater 118 connecting the expansion chamber 113 and the compression chamber 116 and receiving thermal energy from the sealed container 5 of the heat generating device 3, a cooler 119 disposed between the compression chamber 116 and the heater 118, a regenerator 120 disposed between the cooler 119 and the heater 118, and a crankshaft 122 as an output shaft connected to the expansion piston 114 and the compression piston 117 individually by connecting rods 121 a and 121 b.

[0105] A crankshaft 122 (output shaft) of the Stirling engine 110 is connected to an input shaft of the generator 111. When the crankshaft 122 rotates, the rotor of the generator 111 is driven, and the generator 111 generates electricity.

[0106] The expansion piston 114 is displaced within the first cylinder 112 along the axial direction of the first cylinder 112. When the expansion piston 114 moves away from the closed end of the first cylinder 112, the expansion chamber 113 expands. When the expansion piston 114 approaches the closed end of the first cylinder 112, the expansion chamber 113 contracts. The axial reciprocating motion of the expansion piston 114 is converted into rotational motion of the crankshaft 122. A working fluid is sealed in the expansion chamber 113. Here, helium gas is used as the working fluid. In addition to helium gas, a hydrogen-based gas or air may also be used as the working fluid.

[0107] The compression piston 117 is displaced within the second cylinder 115 along the axial direction of the second cylinder 115. When the compression piston 117 moves away from the closed end of the second cylinder 115, the compression chamber 116 expands. When the compression piston 117 approaches the closed end of the second cylinder 115, the compression chamber 116 contracts. The rotational motion of the crankshaft 122 is converted into axial reciprocating motion of the compression piston 117. Because the compression chamber 116 is connected to the expansion chamber 113, the compression chamber 116 is filled with working fluid in the same way as the expansion chamber 113. The working fluid travels between the expansion chamber 113 and the compression chamber 116 via a heater 118, a regenerator 120, and a cooler 119.

[0108] The heater 118 transfers heat from the sealed container 5 to the working fluid. The working fluid is heated by the heat-generating structure 8 housed in the sealed container 5 and flows into the expansion chamber 113. The expansion chamber 113 expands in response to the expansion of the working fluid. The expansion piston 114 is displaced toward the crankshaft 122. The high-temperature, high-pressure working fluid flows from the heater 118 into the regenerator 120 in response to the contraction of the expansion chamber 113.

[0109] The cooler 119 cools the working fluid using a cooling medium (not shown). The cooling medium is, for example, water. The working fluid is cooled by the cooling medium and flows into the compression chamber 116. The compression chamber 116 expands. The compression piston 117 is displaced toward the crankshaft 122. As the compression chamber 116 contracts, the low-temperature, low-pressure working fluid flows from the regenerator 120 into the heater 118.

[0110] The regenerator 120 absorbs and stores thermal energy from the working fluid flowing in from the heater 118, and transfers the stored thermal energy to the working fluid flowing in from the cooler 119. Therefore, the working fluid in the expansion chamber 113 releases thermal energy in the regenerator 120 before flowing into the cooler 119. The working fluid in the compression chamber 116 is heated in the regenerator 120 before flowing into the heater 118.

[0111] As described above, the heat utilization system 1b uses, as a heat source, a heat medium heated by a heat generating device 3 equipped with a heating element 14 that generates heat by absorbing and releasing hydrogen, and therefore can supply energy cheaply, cleanly, and safely.

[0112] (4) Heat Utilization System According to the Fourth Embodiment Fig. 9 is a conceptual diagram showing the general configuration of a heat utilization system 1c according to the fourth embodiment. The heat utilization system 1c includes a heat utilization device 4c instead of the heat utilization device 4 of the first embodiment. The heat utilization device 4c includes a thermoelectric converter 130 that generates electricity based on a temperature difference. Note that components and members that are the same as or equivalent to those in the above embodiments are designated by the same reference numerals and will not be described again.

[0113] The thermoelectric converter 130 has a heat receiving plate 131 and a heat dissipation plate 132. A high-temperature pipe 133 is in contact with the heat receiving plate 131. The high-temperature pipe 133 is connected to the pipe path 2 and allows a heat medium to flow through it. A low-temperature pipe 134 is in contact with the heat dissipation plate 132. The low-temperature pipe 134 allows cooling water to flow through it.

[0114] The thermoelectric converter 130 is sandwiched between a heat receiving plate 131 and a heat dissipation plate 132, and includes a p-type semiconductor 135a and an n-type semiconductor 135b arranged in parallel between the heat receiving plate 131 and the heat dissipation plate 132. The p-type semiconductor 135a and the n-type semiconductor 135b are electrically connected in series alternately based on a first electrode fixed to the heat receiving plate 131 and a second electrode fixed to the heat dissipation plate 132. Electric power is extracted from the second electrodes located at both ends of the series connection.

[0115] As described above, the heat utilization system 1c uses, as a heat source, a heat medium heated by a heat generating device 3 equipped with a heating element 14 that generates heat by absorbing and releasing hydrogen, and therefore can supply energy cheaply, cleanly, and safely.

[0116] The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, in the heat utilization systems 1a, 1b, and 1c, the heat generating device 3 may include a heat generating element 90 instead of the heat generating element 14. In the heat utilization systems 1a, 1b, and 1c, the heat generating device 3 may include a heat generating structure 98 instead of the heat generating structure 8.

[0117] 3 Heat generating device 5 Sealed container 6 Hydrogen tank 7 Vacuum pump 8, 98 Heat generating structure 9 Space 10 Inlet pipe 11 Exhaust pipe 12 Supply valve 13 Exhaust valve 14, 90, 94 Heat generating element 15, 95 Electrode portion 16, 96 Insulator 18 Conductive wire 17 Temperature sensor 19 Current source 21 Control unit 61, 91 Support 62, 92 Multilayer film 71 First layer 72 Second layer 73 Interface between different materials

Claims

1. A heating element comprising a support that generates Joule heat when an electric current flows through it, and a multilayer film attached to the support that generates heat by absorbing and releasing hydrogen; and a pair of electrodes attached to the support and connected to a current source, wherein the multilayer film has a first layer less than 1000 nm thick made of a hydrogen storage metal or hydrogen storage alloy, and a second layer less than 1000 nm thick made of a hydrogen storage metal, hydrogen storage alloy or ceramic different from the first layer, wherein the support generates heat when an electric current is applied from the current source via the pair of electrodes, thereby heating the multilayer film.

2. The heat generating structure according to claim 1, wherein said support has a uniform electrical resistance in the direction in which said current flows.

3. The heat generating structure according to claim 2, wherein the support has a uniform cross-sectional area in the direction in which the current flows.

4. The heat generating structure according to claim 1, wherein the heat generating element is a long member.

5. The heat generating structure according to claim 4, further comprising an insulator supporting said heat generating element.

6. The heat generating structure according to claim 5, wherein the insulator is formed in a cylindrical shape, and the heat generating element is wound spirally around the outer circumferential surface of the insulator.

7. The heat generating structure according to claim 5, wherein the insulator is formed in a plate shape, and the heat generating element is arranged in a spiral on the surface of the insulator.

8. The heat generating structure according to claim 5, wherein the insulator is made of quartz or ceramics.

9. A heating device comprising: a heating structure according to any one of claims 1 to 8; a sealed container that houses said heating structure; a supply unit that supplies a hydrogen-based gas containing hydrogen into the sealed container; a discharge unit that discharges the hydrogen-based gas from the sealed container; and a current source connected to said pair of electrodes.

Images