Heating device

Abstract

To provide a heating device that can improve startup performance and durability. [Solution] The heating device 3 comprises a sealed container 5 to which a hydrogen-containing hydrogen-based gas is supplied, a first heating structure 8 having a first heater 15 and provided inside the sealed container 5, a plurality of second heating structures 9 having a heating element 14b and a second heater 16 that generate heat by the absorption and release of hydrogen, provided inside the sealed container 5 and arranged to surround the first heating structure 8, and a control unit 21 that controls the on / off of the first heater 15 and the second heater 16. The heat capacity of the first heater 15 is smaller than the heat capacity of the second heater 16, and the control unit 21 performs startup control by turning on the first heater 15 and the second heater 16 at startup, and turning off the first heater 15 while keeping the second heater 16 on when startup is complete.

Description

Technical Field

[0001] The present invention relates to a heating device.

Background Art

[0002] In recent years, a heating device has been proposed that includes a container into which a hydrogen-based gas that contributes to heat generation is introduced, a heating element provided inside the container, and a heater that heats the heating element (see Patent Document 1). The container is connected to a hydrogen-based gas introduction path having a tank for storing a hydrogen-based gas and an exhaust path having a dry pump. The heater is a ceramic heater. The heating element includes a pedestal made of a hydrogen storage metal, a hydrogen storage alloy, or a proton conductor, and a multilayer film formed on the surface of the pedestal. The multilayer film includes a layered first layer made of a hydrogen storage metal or a hydrogen storage alloy and having a thickness of less than 1000 nm, and a layered 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, and the first layer and the second layer are laminated. A heterogeneous material interface is formed between the first layer and the second layer. In the heating device of Patent Document 1, after introducing a hydrogen-based gas into the container and causing the heating element to absorb hydrogen, the inside of the container is evacuated and the heating element is heated, so that hydrogen permeates through the heterogeneous material interface by quantum diffusion in the heating element, or hydrogen diffuses through the heterogeneous material interface by quantum diffusion, and the heating element generates excess heat.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the heating device described in Patent Document 1, it takes time from the time the heater is turned on and the heating element starts heating until the heating element generates excessive heat. If excessive power is supplied to the heater to speed up the heating rate, the heater will be damaged and its lifespan will be shortened.

[0005] The present invention aims to provide a heating device that can improve startup performance and durability. [Means for solving the problem]

[0006] The heating device according to the present invention comprises a sealed container to which a hydrogen-containing hydrogen-based gas is supplied, a first heating structure provided inside the sealed container having a first heater that generates heat when electricity is supplied, a plurality of second heating structures provided inside the sealed container and arranged to surround the first heating structure, having a heating element that generates heat by the absorption and release of hydrogen and a second heater that generates heat when electricity is supplied, and a control unit that controls the on / off of the first heater and the second heater, wherein the heating element has a support made of a hydrogen storage metal, a hydrogen storage alloy, or a proton conductor, and the support The second heating structure has a multilayer film, the multilayer film having 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, the heating element of the second heating structure is arranged so as to surround the second heater, the heat capacity of the first heater is smaller than the heat capacity of the second heater, and the control unit performs startup control by turning on the first heater and the second heater at startup, and turning off the first heater while keeping the second heater on when startup is complete. [Effects of the Invention]

[0007] According to the present invention, startup performance and durability can be improved. [Brief explanation of the drawing]

[0008] [Figure 1]This is a conceptual diagram illustrating the heating device. [Figure 2A] This is a perspective view of the first heat-generating structure and a plurality of second heat-generating structures. [Figure 2B] This is a top view of the first heat-generating structure and multiple second heat-generating structures. [Figure 3] This graph shows the startup characteristics of lamp heaters, sheathed heaters, and ceramic heaters. [Figure 4] This is a cross-sectional view showing the configuration of the heating element. [Figure 5] This is an explanatory diagram for explaining startup control. [Figure 6] This is a flowchart showing the operation of the heating device. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In the following description and drawings, common components are denoted by the same reference numerals. Descriptions of components denoted by the same reference numerals will be omitted as appropriate.

[0010] In Figure 1, the heat utilization system 1 comprises a piping route 2 through which a heat transfer medium flows, a heating device 3 that heats the heat transfer medium flowing through the piping route 2, and a heat utilization device 4 that uses the heat transfer medium heated by the heating device 3 as a heat source. The heating device 3 and the heat utilization device 4 are incorporated into the piping route 2. The piping route 2 forms a sealed circulation path between the heating device 3 and the heat utilization device 4.

[0011] As a heat transfer medium, a gas or liquid can be used, and one with excellent thermal conductivity and chemical stability is preferred. Examples of gases include helium, argon, hydrogen, nitrogen, water vapor, air, and carbon dioxide. Examples of liquids include water, molten salts (such as KNO3 (40%)-NaNO3 (60%)), and liquid metals (such as Pb). Alternatively, a multiphase heat transfer medium in which solid particles are dispersed in a gas or liquid may be used. The solid particles may be metals, metal compounds, alloys, or ceramics. Examples of metals include Cu, Ni, Ti, and Co. Examples of metal compounds include oxides, nitrides, and silicides of the above metals. Examples of alloys include stainless steel and chromium-molybdenum steel. Examples of ceramics include alumina.

[0012] The heating device 3 will now be described. The heating 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, a first heating structure 8 housed in the sealed container 5, and a plurality of second heating structures 9 housed in the sealed container 5.

[0013] The sealed container 5 has heat resistance and pressure resistance. The sealed container 5 is made of, for example, stainless steel or heat-resistant non-ferrous alloy steel. The material used for the sealed container 5 is appropriate to the operating temperature. 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 formed in a cylindrical shape. The sealed container 5 consists of a body, an upper lid provided at the upper end of the body, and a lower lid provided at 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 partitioning the space S inside the sealed container 5. The shape of the sealed container 5 is not limited to a cylindrical shape, but may also be elliptical, rectangular, spherical, etc. In the heating device 3, the upper lid side of the sealed container 5 is considered the upper side, and the lower lid side of the sealed container 5 is considered the lower side.

[0014] The heating device 3 has an introduction pipe 10 connecting the sealed container 5 and the hydrogen tank 6, and an exhaust pipe 11 connecting the sealed container 5 and the vacuum pump 7. The introduction pipe 10 extends from the lower lid of the sealed container 5 and is coupled to the hydrogen tank 6, constituting an introduction path for guiding the hydrogen-based gas stored in the hydrogen tank 6 into the internal space S of the sealed container 5. The exhaust pipe 11 extends from the upper lid of the sealed container 5 and is coupled to the vacuum pump 7, constituting an exhaust path for guiding the hydrogen-based gas sucked from the internal space S of the sealed container 5 to the vacuum pump 7.

[0015] The introduction 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 introduction pipe 10. As the supply valve 12, for example, an electromagnetic valve or an air valve is used. The introduction pipe 10 may have a pressure sensor for detecting the pressure of the hydrogen-based gas flowing through the introduction pipe 10.

[0016] 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. As the exhaust valve 13, for example, an electromagnetic valve or an air valve is used. The exhaust pipe 11 may have a pressure sensor for detecting the pressure of the hydrogen-based gas flowing through the exhaust pipe 11.

[0017] When the exhaust valve 13 is closed and the supply valve 12 is opened, it becomes possible to supply the hydrogen-based gas from the hydrogen tank 6 to the internal space S of the sealed container 5. When the supply valve 12 is closed and the exhaust valve 13 is opened, it becomes possible to discharge the hydrogen-based gas in the internal space S of the sealed container 5 by the vacuum pump 7.

[0018] 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 space S inside the low-pressure sealed container 5 through the introduction pipe 10. The hydrogen-based gas is a gas containing isotopes of hydrogen. As the hydrogen-based gas, at least one of deuterium gas and light hydrogen gas is used. The light hydrogen gas includes a naturally occurring mixture of 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%. The introduction pipe 10 may have a pump that sends out the hydrogen-based gas stored in the hydrogen tank 6 to the space S inside the sealed container 5.

[0019] The vacuum pump 7 discharges the hydrogen-based gas from the inside of the sealed container 5 through the exhaust pipe 11. By driving the vacuum pump 7, the space S inside the sealed container 5 is decompressed. The vacuum pump 7 is composed of, for example, a turbo molecular pump and a dry pump. The turbo molecular pump adjusts the rotational speed of the turbine blades based on a control signal input from a control unit 21 described later. The decompression rate of the space S is adjusted according to the rotational speed of the turbo molecular pump.

[0020] The first heat generating structure 8 and the plurality of second heat generating structures 9 heat 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 first heat generating structure 8 and the plurality of second heat generating structures 9 reaches, for example, a range of 50°C or more and 1500°C or less.

[0021] The configurations of the first heat generating structure 8 and the plurality of second heat generating structures 9 will be described with reference to FIGS. 2A and 2B. FIG. 2A is a perspective view of the first heat generating structure 8 and the plurality of second heat generating structures 9. FIG. 2B is a top view of the first heat generating structure 8 and the plurality of second heat generating structures 9. The first heat generating structure 8 is provided inside the sealed container 5. The plurality of second heat generating structures 9 are provided inside the sealed container 5 and are arranged so as to surround the first heat generating structure 8. In the present embodiment, the heat generating device 3 includes one first heat generating structure 8 and six second heat generating structures 9, and has a configuration in which the six second heat generating structures 9 are arranged so as to surround the one first heat generating structure 8.

[0022] The first heat-generating structure 8 has a heat-generating element 14 that generates heat by the absorption and release of hydrogen, and a first heater 15 that generates heat by the supply of electricity. The second heat-generating structure 9 has a heat-generating element 14 that generates heat by the absorption and release of hydrogen, and a second heater 16 that generates heat by the supply of electricity. The heat-generating element 14 of the first heat-generating structure 8 and the heat-generating element 14 of the second heat-generating structure 9 have the same configuration. Hereinafter, when distinguishing between the heat-generating element 14 of the first heat-generating structure 8 and the heat-generating element 14 of the second heat-generating structure 9, the heat-generating element 14 of the first heat-generating structure 8 will be referred to as heat-generating element 14a, and the heat-generating element 14 of the second heat-generating structure 9 will be referred to as heat-generating element 14b.

[0023] The heating element 14 is formed in a cylindrical shape. In this embodiment, the heating element 14 is formed in a cylindrical shape. The heating element 14 has a uniform diameter along its entire length in the direction along the central axis. Note that "uniform" includes not only cases where it is strictly uniform, but also cases where it is approximately uniform, that is, cases where it differs within a range that does not depart from the spirit of the invention. The heating element 14 is not limited to being cylindrical, but may also be polygonal cylindrical. If the heating element 14 is polygonal cylindrical, the diameter of the heating element 14 is the diameter of the circumscribed circle of the heating element 14. The configuration of the heating element 14 will be described later with reference to separate drawings.

[0024] In this embodiment, the central axis of the heating element 14a is referred to as the central axis of the first heating structure 8, and the central axis of the heating element 14b is referred to as the central axis of the second heating structure 9. In the first heating structure 8 and the second heating structure 9, the direction along the central axis is defined as the axial direction, the direction perpendicular to the central axis is defined as the radial direction, and the direction around the central axis is defined as the circumferential direction.

[0025] A first heater 15 is positioned on the inner diameter side of the heating element 14a. The heating element 14a constitutes the outer shape of the first heating structure 8. That is, the first heating structure 8 has a cylindrical outer shape and is configured such that the heating element 14a surrounds the first heater 15. The heating surface of the first heating structure 8 is made up of the heating element 14a. The diameter of the first heating structure 8 is the diameter of the heating element 14a.

[0026] A second heater 16 is positioned on the inner diameter side of the heating element 14b. The heating element 14b constitutes the outer shape of the second heating structure 9. That is, the second heating structure 9 has a cylindrical outer shape and is configured such that the heating element 14b surrounds the second heater 16. The heating surface of the second heating structure 9 is made up of the heating element 14b. The diameter of the second heating structure 9 is the diameter of the heating element 14b.

[0027] The first heater 15 is surrounded by the heating element 14a. The first heater 15 is formed in a cylindrical shape. The central axis of the first heater 15 coincides with the central axis of the heating element 14a. "Coincidence" includes not only cases where they are exactly the same, but also cases where they are approximately the same, i.e., cases where they differ within the scope of the invention. In this embodiment, the first heater 15 is formed in a cylindrical shape. The first heater 15 has a uniform diameter along its entire length in the direction along the central axis (axial direction). The first heater 15 is not limited to being cylindrical, but may also be polygonal. If the first heater 15 is polygonal, the diameter of the first heater 15 is the diameter of the circumscribed circle of the first heater 15.

[0028] The first heater 15 is a lamp heater. The lamp heater has a hollow pipe made of quartz glass, a filament provided inside the pipe, and lead wires connected to the filament and extending to the outside of the pipe. An inert gas is sealed inside the pipe. The lamp heater generates heat in the filament when the lead wires are electrically connected to a power source and power is supplied from the power source to the filament via the lead wires. The pipe allows the radiant heat generated from the filament to pass through. For example, a halogen heater can be used as a lamp heater. A halogen heater has a configuration in which a tungsten filament is sealed together with halogen gas inside a quartz glass pipe.

[0029] The first heater 15 has a pair of electrode portions 20a (see Figure 1). The pair of electrode portions 20a are connected to a conductive wire 18a. The conductive wire 18a is connected to a power supply 19, electrically connecting the pair of electrode portions 20a and the power supply 19. The first heater 15 generates radiant heat when power is supplied from the power supply 19 via the conductive wire 18a and the pair of electrode portions 20a. The first heater 15 heats the heating element 14a with radiant heat. In Figure 1, the pair of electrode portions 20a are provided at one end of the first heater 15, but they may be provided at the other end or both ends of the first heater 15.

[0030] The second heater 16 is surrounded by the heating element 14b (see Figures 2A and 2B). The second heater 16 is formed in a cylindrical shape. The central axis of the second heater 16 coincides with the central axis of the heating element 14b. In this embodiment, the second heater 16 is formed in a cylindrical shape. The second heater 16 has a uniform diameter along its entire length in the direction along the central axis (axial direction). The second heater 16 is not limited to being cylindrical, but may also be polygonal. If the second heater 16 is polygonal, the diameter of the second heater 16 is the diameter of the circumscribed circle of the second heater 16.

[0031] The second heater 16 is either a sheathed heater or a ceramic heater. A sheathed heater has a hollow pipe made of metal or an alloy, a heating resistor provided inside the pipe, and terminals connected to the heating resistor and extending to the outside of the pipe. An insulator is housed inside the pipe. The sheathed heater generates heat in the heating resistor when the terminals are electrically connected to a power source and current is supplied from the power source to the heating resistor via the terminals. The pipe is heated by the heat generated in the heating resistor. A ceramic heater has a cylindrical pipe made of ceramics, a heating resistor provided inside the pipe, and terminals connected to the heating resistor and extending to the outside of the pipe. The ceramic heater generates heat in the heating resistor when the terminals are electrically connected to a power source and current is supplied from the power source to the heating resistor via the terminals. The pipe is heated by the heat generated in the heating resistor. In this embodiment, the second heater 16 is a sheathed heater.

[0032] The second heater 16 has a pair of electrode portions 20b (see Figure 1). The pair of electrode portions 20b are connected to a conductive wire 18b. The conductive wire 18b is connected to a power supply 19, electrically connecting the pair of electrode portions 20b to the power supply 19. The second heater 16 generates radiant heat when power is supplied from the power supply 19 via the conductive wire 18b and the pair of electrode portions 20b. The second heater 16 heats the heating element 14b with radiant heat. In Figure 1, the pair of electrode portions 20b are provided at one end of the second heater 16, but they may be provided at the other end or both ends of the second heater 16.

[0033] The heat capacity of the first heater 15 is smaller than that of the second heater 16. When the first heater 15 and the second heater 16 are turned on simultaneously, the time it takes for the first heater 15 to reach a specific temperature is shorter than the time it takes for the second heater 16 to reach a specific temperature. In other words, the first heater 15 starts up faster than the second heater 16. The specific temperature is set, for example, within the range of the optimal temperature for heating the heating element 14 (for example, between 50°C and 1500°C). The first heater 15 can bring the heating element 14 to the optimal temperature for heating in a shorter time than the second heater 16. The first heater 15 has better temperature control responsiveness than the second heater 16. The time it takes from turning on the heater to reaching a specific temperature is also called the start-up time.

[0034] Figure 3 is a graph showing the rise characteristics of a lamp heater, sheath heater, and ceramic heater. In Figure 3, the horizontal axis represents time [min], and the vertical axis represents the temperature attainment rate [%], which is the percentage of time it takes to reach a specific temperature. In Figure 3, the lamp heater is shown by a solid line, the sheath heater by a dotted line, and the ceramic heater by a dashed line.

[0035] As shown in Figure 3, when the lamp heater, sheath heater, and ceramic heater are turned on simultaneously, the rise time to reach a specific temperature is shortest in the order of lamp heater, sheath heater, and ceramic heater. In other words, the rise time is fastest in the order of lamp heater, sheath heater, and ceramic heater. The lamp heater has a steeper rise time characteristic than the sheath heater and ceramic heater, and can bring the heating element 14 to the optimal temperature for heating in a shorter time than the sheath heater and ceramic heater. The sheath heater has a steeper rise time characteristic than the ceramic heater, and can bring the heating element 14 to the optimal temperature for heating in a shorter time than the ceramic heater. Although not shown in the figure, when the lamp heater, sheath heater, and ceramic heater are turned off simultaneously, the fall time is fastest in the order of lamp heater, sheath heater, and ceramic heater.

[0036] The heating device 3 has multiple second heating structures 9 arranged at equal intervals in the circumferential direction of the first heating structure 8, and also at equal intervals from the central axis of the first heating structure 8. Hydrogen-based gas flows through the gaps between the first heating structure 8 and each of the second heating structures 9, and between adjacent second heating structures 9 among the multiple second heating structures 9. The gaps between the first heating structure 8 and each of the second heating structures 9, and between adjacent second heating structures 9 among the multiple second heating structures 9, constitute a flow path for the hydrogen-based gas.

[0037] The vacuum conductance in the gap between the first heat-generating structure 8 and the second heat-generating structure 9 is C[cm 3 When the correction coefficient is Ks, the diameter of the second heating structure 9 is R[mm], and the dimension of the second heating structure 9 in the direction along the longer side of the flow channel cross-section (cross-section perpendicular to the circumferential direction) is a[mm], the heating device 3 is provided with a gap L[mm] between the first heating structure 8 and the second heating structure 9 that satisfies Equation 1. {C / (30.9Ks)×(πR / 2) / a} (1 / 2) ≦L≦1.2 (Formula 1)

[0038] If the gap L between the first heating structure 8 and the second heating structure 9 is too narrow, gas will not be exhausted from the gap between the first heating structure 8 and the second heating structure 9 to the exhaust pipe 11, and the hydrogen-based gas introduced from the inlet pipe 10 will not be able to reach the gap between the first heating structure 8 and the second heating structure 9, preventing the heating element 14 from absorbing sufficient hydrogen. As a result, it becomes difficult to increase the heat output of the heating element 14, and it becomes difficult to improve the COP (coefficient of performance), which is the ratio of the heat output of the heating element 14 to the power supplied to the first heater 15 and the second heater 16. If the gap L between the first heating structure 8 and the second heating structure 9 is too wide, the amount of heat radiated from each heating surface of the first heating structure 8 and the second heating structure 9 to the surroundings increases, and heat loss due to radiation increases. As a result, the power required to keep the heating element 14 within the optimal temperature range for heating (for example, 50°C to 1500°C), i.e., the power supplied to the first heater 15 and the second heater 16, increases, and the COP decreases.

[0039] The heating device 3 has a gap L [mm] between the first heating structure 8 and the second heating structure 9 that satisfies Equation 1. As a result, gas is exhausted from the gap between the first heating structure 8 and the second heating structure 9, and hydrogen-based gas spreads throughout the gap, allowing sufficient hydrogen to be absorbed by the heating element 14, thereby improving the amount of heat generated by the heating element 14. The amount of heat radiated to the surroundings from each heating surface of the first heating structure 8 and the second heating structure 9 is reduced, reducing heat loss due to radiation, allowing the heating element 14 to be heated efficiently, and reducing the power supplied to the first heater 15 and the second heater 16. Therefore, the heating device 3 can improve the COP.

[0040] The structure of the heating element 14 will be explained using Figure 4. Figure 4 is a cross-sectional view showing the structure of the heating element 14. As shown in Figure 4, the heating element 14 has a support 61 (also referred to as a base) made of a hydrogen-absorbing metal, hydrogen-absorbing alloy, or proton conductor, and a multilayer film 62 provided on the support 61. The multilayer film 62 has a first layer 71 less than 1000 nm thick made of a hydrogen-absorbing metal or hydrogen-absorbing alloy, and a second layer 72 less than 1000 nm thick made of a hydrogen-absorbing metal, hydrogen-absorbing alloy, or ceramic different from the first layer 71. A heterogeneous material interface 73 is formed between the first layer 71 and the second layer 72, and between the support 61 and the multilayer film 62. The heterogeneous material interface 73 allows hydrogen atoms to pass through. The heating element 14 generates excess heat when hydrogen atoms pass through the heterogeneous material interface 73 by quantum diffusion, or when hydrogen atoms diffuse through the heterogeneous material interface 73 by quantum diffusion. As the heating element 14, heating elements disclosed in International Publications WO2018 / 230447, WO2020 / 122097, WO2020 / 122098, etc., can be used. The detailed configuration, function, and manufacturing method of the heating element 14 are the same as those disclosed in International Publications WO2018 / 230447, WO2020 / 122097, WO2020 / 122098, etc., and therefore will not be explained here.

[0041] In Figure 4, the multilayer film 62 is shown as being laminated on one side (e.g., the front surface) of the support 61. However, the design is not limited to this configuration. The multilayer film 62 may also be laminated on the other side (e.g., the back surface) of the support 61, or it may be laminated on both sides (the front and back surfaces) of the support 61.

[0042] The heating device 3 includes a temperature sensor 17 that detects the temperature of the heating element 14 (see Figure 1). The temperature sensor 17 is located inside the sealed container 5. The temperature sensor 17 outputs a detection signal that identifies the detected temperature. The temperature sensor 17 has, for example, a thermocouple embedded in the heating element 14. The thermocouple outputs a voltage that identifies the detected temperature. The temperature sensor 17 is not limited to being located inside the sealed container 5, but may also be located outside the sealed container 5. When the temperature sensor 17 is located outside the sealed container 5, an infrared radiation thermometer may be used as the temperature sensor 17. By providing a viewport made of an infrared-transmitting material such as Kovar glass in the sealed container 5, the temperature of the heating element 14 can be detected by the temperature sensor 17 as an infrared radiation thermometer through the viewport.

[0043] When distinguishing between heating element 14a and heating element 14b, the temperature sensor 17 that detects the temperature of heating element 14a is referred to as temperature sensor 17a, and the temperature sensor 17 that detects the temperature of heating element 14b is referred to as temperature sensor 17b. In this embodiment, temperature sensor 17a detects the temperature of heating element 14a at a position 1 / 4 of the diameter of the first heating structure 8 from its center. Temperature sensor 17b detects the temperature of heating element 14b at a position 1 / 4 of the diameter of the second heating structure 9 from its center.

[0044] The heating device 3 includes a vacuum pump 7, a supply valve 12, an exhaust valve 13, a temperature sensor 17 (temperature sensors 17a, 17b), and a control unit 21 electrically connected to a power supply 19. The control unit 21 includes, for example, a microprocessor (MPU) that performs arithmetic processing based on application programs stored in read-only memory (ROM) or other storage units, and random access memory (RAM) that temporarily holds programs and data during arithmetic processing.

[0045] The control unit 21 outputs control signals to control the operation of the vacuum pump 7, the supply valve 12, the exhaust valve 13, and the power supply 19, respectively. The vacuum pump 7, the supply valve 12, the exhaust valve 13, and the power supply 19 operate based on the control signals input from the control unit 21.

[0046] The control unit 21 supplies hydrogen-based gas to the space S inside the sealed container 5 by stopping the operation of the vacuum pump 7, closing the exhaust valve 13, and opening the supply valve 12. The control unit 21 then discharges the hydrogen-based gas from the space S inside the sealed container 5 (vacuum evacuation) by closing the supply valve 12, opening the exhaust valve 13, and driving the vacuum pump 7. In the heating device 3, the hydrogen tank 6, the introduction pipe 10, and the supply valve 12 constitute a supply unit that supplies hydrogen-based gas containing hydrogen to the inside of the sealed container 5. In the heating device 3, the vacuum pump 7, the exhaust pipe 11, and the exhaust valve 13 constitute a discharge unit that discharges the hydrogen-based gas from inside the sealed container 5. In other words, the heating device 3 comprises a supply unit that supplies hydrogen-based gas containing hydrogen to the inside of the sealed container 5 and a discharge unit that discharges the hydrogen-based gas from inside the sealed container 5.

[0047] The control unit 21 is configured to control the on / off state of the first heater 15 and the second heater 16. The control unit 21 controls the output of the power supply 19 and controls the power supplied from the power supply 19 to the first heater 15 and the second heater 16 via conductive wires 18a, 18b and a pair of electrode sections 20a, 20b, thereby switching the first heater 15 and the second heater 16 on / off.

[0048] The control unit 21 adjusts the amount of power supplied from the power supply 19 to the first heater 15 and the second heater 16 via conductive wires 18a, 18b and a pair of electrode sections 20a, 20b. By adjusting the amount of power, the temperature of the heating element 14 heated by the first heater 15 and the second heater 16 is adjusted, making it possible to maintain the heating element 14 within an optimal temperature range for heating (for example, 50°C to 1500°C).

[0049] The control unit 21 controls the operation of the vacuum pump 7, supply valve 12, exhaust valve 13, and power supply 19, respectively, when the heating device 3 is started and stopped. The heating device 3 is equipped with a start switch (not shown). When the start switch is turned ON, a start signal is input from the start switch to the control unit 21. When the start switch is turned OFF, a stop signal is input from the start switch to the control unit 21. Upon receiving the start signal from the start switch, the control unit 21 operates the vacuum pump 7, supply valve 12, exhaust valve 13, and power supply 19 to generate heat in the heating element 14. Upon receiving the stop signal from the start switch, the control unit 21 stops the operation of the vacuum pump 7, supply valve 12, exhaust valve 13, and power supply 19, and stops the heating of the heating element 14.

[0050] As shown in Figure 5, the control unit 21 performs startup control by turning on the first heater 15 and the second heater 16 at startup, and turning off the first heater 15 while keeping the second heater 16 on when startup is complete. In Figure 5, the horizontal axis represents time [min] and the vertical axis represents temperature [°C]. In Figure 5, the temperature of the first heater 15 is shown by a solid line, the temperature of the second heater 16 is shown by a dotted line, and the temperature at a position 1 / 4 of the diameter of the second heating structure 9 from the center of the second heating structure 9 (i.e., the temperature of the heating element 14b detected by the temperature sensor 17b) is shown by a dashed line. Startup occurs when a startup switch (not shown) is turned on. Startup completion occurs when each of the heating elements 14b of the multiple second heating structures 9 reaches the optimal temperature for heating. The heating element 14a of the first heating structure 8 is arranged to surround the first heater 15 and is heated by the first heater 15, causing its temperature to rise instantaneously. Therefore, when each of the heating elements 14b of the multiple second heating structures 9 reaches the optimal temperature for heating, the heating element 14a of the first heating structure 8 also reaches the optimal temperature for heating.

[0051] Here, heaters that generate heat when power is supplied tend to have a shorter lifespan the smaller their heat capacity. Heating device 3 is equipped with a first heater 15 and a second heater 16 that generate heat when power is supplied. When the first heater 15 and the second heater 16 are turned on at startup, the first heater 15, which has a small heat capacity, can quickly bring the heating element 14 to the optimal temperature for heating. At the end of startup, the second heater 16 is left on and the first heater 15 is turned off, allowing the second heater 16 to maintain the heating element 14 at the optimal temperature for heating while extending the lifespan of the first heater 15. The first heater 15 is turned on when the heating device 3 is started and functions as an ignition heater that quickly brings the heating element 14 to the optimal temperature for heating.

[0052] In this embodiment, the control unit 21 turns on the first heater 15 and the second heater 16 at startup, and then reduces the output of the first heater 15 when heat generation begins. That is, the control unit 21 turns on the first heater 15 and the second heater 16 at startup, reduces the output of the first heater 15 when heat generation begins, and turns off the first heater 15 while keeping the second heater 16 on when startup is complete. Heat generation begins when the heating element 14b of any one of the multiple second heat generation structures 9 reaches the optimal temperature for heat generation and heat generation begins. The temperature at which the heating element 14b of any one of the multiple second heat generation structures 9 reaches the optimal temperature for heat generation is called the heat generation start temperature. When the heating element 14b of any one of the multiple second heating structures 9 reaches its heating start temperature, the heat generated by that heating element 14b heats the heating element 14b of the second heating structure 9 adjacent to that second heating structure 9. The heating element 14b of one adjacent second heating structure 9 functions as a heat source for the heating element 14b of the other second heating structure 9, thereby efficiently heating the heating element 14b of the other second heating structure 9. Even if the output of the first heater 15 is reduced at the start of heating, the multiple heating elements 14b can be brought to the optimal temperature for heating.

[0053] The heating device 3 is provided between the first heating structure 8 and the second heating structure 9 and includes a spacer 22 having a coefficient of linear expansion less than or equal to that of the heating elements 14 (heating elements 14a and 14b) (see Figure 2B). The spacer 22 is in contact with the heating element 14a of the first heating structure 8 and with the heating element 14b of the second heating structure 9. Compared to the case where the coefficient of linear expansion of the spacer 22 is greater than that of the heating elements 14a and 14b, the heating device 3 reduces the thermal stress at the contact surface between the heating element 14a and the spacer 22, and also reduces the thermal stress at the contact surface between the heating element 14b and the spacer 22. Therefore, damage to the heating elements 14a and 14b at the contact surface can be prevented. In this embodiment, the first heating structure 8 has a heating element 14a and a first heater 15, and the heating element 14a is arranged to surround the first heater 15. However, if the first heating structure 8 consists only of the first heater 15, the spacer 22 will be in contact with the first heater 15 of the first heating structure 8 and also in contact with the heating element 14b of the second heating structure 9. In this case, it is preferable that the spacer 22 has a coefficient of linear expansion less than or equal to the coefficient of linear expansion of the heating element 14b or the first heater 15. Compared to the case where the coefficient of linear expansion of the spacer 22 is greater than the coefficient of linear expansion of the heating element 14b or the first heater 15, the thermal stress at the contact surface between the heating element 14b and the spacer 22 will be smaller, and the thermal stress at the contact surface between the first heater 15 and the spacer 22 will be smaller. Therefore, damage to the heating element 14b at the contact surface can be prevented.

[0054] As for the material used for the spacer 22, for example, if the surface of the heating element 14 is made of Ni (coefficient of linear expansion is approximately 12.8E-6 / °C), then Ni, SUS430 (coefficient of linear expansion is approximately 10.4E-6 / °C), SUS410 (coefficient of linear expansion is approximately 9.9E-6 / °C), SUS630 (coefficient of linear expansion is approximately 10.8E-6 / °C), alumina (coefficient of linear expansion is approximately 7.0E-6 / °C), silicon carbide (coefficient of linear expansion is approximately 4.0E-6 / °C), silicon nitride (coefficient of linear expansion is approximately 3.0E-6 / °C), zirconia (coefficient of linear expansion is approximately 10.0E-6 / °C), and aluminum nitride (coefficient of linear expansion is approximately 5.0E-6 / °C) can be used. Note that SUS430, SUS410, and SUS630 are stainless steels specified by the Japanese Industrial Standards (JIS).

[0055] Ceramics such as alumina, silicon carbide, silicon nitride, zirconia, and aluminum nitride are preferable from the viewpoint of thermal stress because they have a smaller coefficient of thermal expansion compared to metals such as Ni and alloys such as SUS430, SUS410, and SUS630. However, they are more brittle than metals and alloys and may break when placed between the first heating structure 8 and the second heating structure 9. For this reason, the spacer 22 is preferably made of metal or an alloy.

[0056] The heat utilization device 4 will now be described. The heat utilization device 4 comprises a containment vessel 41 that houses the sealed container 5 of the heat generating device 3, a power generation unit 42 that generates electricity based on a heat transfer medium (e.g., helium gas) heated by the heat generating device 3 inside the containment vessel 41, a pressure pump 43 that sends the heat transfer medium from the power generation unit 42 to the containment vessel 41, and a flow control valve 44 provided between the pressure pump 43 and the containment vessel 41.

[0057] The containment vessel 41 has thermal insulation and pressure resistance. The containment vessel 41 is made of, for example, stainless steel or heat-resistant non-ferrous alloy steel. The material used for the containment vessel 41 is appropriate to the operating temperature. 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 transfer medium flows in and an outlet 41b through which the heat transfer medium flows out. The heat transfer medium that flows into the interior of the containment vessel 41 from the inlet 41a flows along the outer surface of the sealed container 5 of the heating device 3 housed inside the containment vessel 41, and is heated by the first heating structure 8 and a plurality of second heating structures 9 housed in the sealed container 5. The temperature of the heat transfer medium rises inside the containment vessel 41, and a high-temperature heat transfer medium is obtained. The high-temperature heat transfer medium flows out from the outlet 41b of the containment vessel 41 and flows into the power generation unit 42.

[0058] The power generation unit 42 generates electricity based on a heat transfer medium heated by the heat generating device 3 inside the containment vessel 41. An example of the configuration of the power generation unit 42 is described below. The power generation unit 42 includes a compressor that compresses the high-temperature heat transfer medium supplied from the containment vessel 41, a gas turbine 42a that is driven by the high-temperature and high-pressure heat transfer medium compressed by the compressor, and a generator 42b connected to the gas turbine 42a. In the power generation unit 42, the temperature of the heat transfer medium is adjusted to a range of, for example, 600°C to 1500°C. The output shaft of the gas turbine 42a is connected to the input shaft of the generator 42b. As the turbine blades of the gas turbine 42a rotate, the rotor of the generator 42b is driven, and electricity is generated (powered) by the generator 42b. The heat transfer medium from which heat has been utilized in the power generation unit 42 flows out of the power generation unit 42 and flows into the pressure pump 43. The power generation unit 42 is not limited to a configuration having a gas turbine 42a, but may also have a configuration having, for example, a steam turbine, a Stirling engine, or an ORCS (Organic Rankine Cycle System).

[0059] The pressure pump 43 sends the heat transfer medium supplied from the power generation unit 42 towards the containment vessel 41 at a predetermined pressure. For example, a metal bellows pump is used as the pressure pump 43.

[0060] The flow control valve 44 adjusts the flow rate of the heat transfer medium flowing from the pressure pump 43 to the containment vessel 41. For example, a variable leak valve can be used as the flow control valve 44.

[0061] The heat utilization device 4 is not limited to a configuration having a power generation unit 42, but may also have a configuration having a heat exchanger, for example. Examples of heat exchangers include devices that perform heat exchange between a heat transfer medium and a gas, devices that perform heat exchange between a heat transfer medium and a liquid, and devices that perform heat exchange between a heat transfer medium and a solid. Devices that perform heat exchange between a heat transfer medium and a gas are used for air conditioning, preheating of air supplied to combustion devices, and generation of hot air for drying and heating. Examples of combustion devices include boilers, rotary kilns, metal heat treatment furnaces, metalworking heating furnaces, hot air furnaces, ceramic firing furnaces, petroleum refining towers, carbonization furnaces, and drying furnaces. Devices that perform heat exchange between a heat transfer medium and a liquid are used as heat sources for boilers, for oil heating, and in chemical reaction vessels. Devices that perform heat exchange between a heat transfer medium and a solid are used in double-tube rotary heaters and for heating particulate matter in double tubes. The heat utilization device 4 may also be a thermoelectric element that converts the thermal energy of the heat generating device 3 into electrical energy via a heat transfer medium.

[0062] The operation and effects of the heating device 3 according to this embodiment will be explained using Figure 6. As shown in Figure 6, when the heating device 3 is started, the control unit 21 turns on the first heater 15 and the second heater 16 (S1). The first heater 15 and the second heater 16 are supplied with predetermined power from the power supply 19. The first heater 15 heats the heating element 14a. The second heater 16 heats the heating element 14b. The temperatures of heating elements 14a and 14b rise. Since the heat capacity of the first heater 15 is smaller than the heat capacity of the second heater 16, the heating element 14a heated by the first heater 15 heats up faster than the heating element 14b heated by the second heater 16, reaches the optimal temperature for heating, and generates excess heat. The heating element 14a that generates excess heat becomes a heat source that heats the multiple heating elements 14b arranged to surround the heating element 14a. The control unit 21 keeps the first heater 15 and the second heater 16 on until the heating element 14b of any one of the multiple second heating structures 9 reaches its heating start temperature (S2: NO). When the heating element 14b of any one of the multiple second heating structures 9 reaches its heating start temperature (S2: YES), the control unit 21 reduces the power supplied to the first heater 15 (S3). The heating element 14b that has reached its heating start temperature generates excess heat. The heating element 14b that generates excess heat becomes a heat source that heats adjacent heating elements 14b. The control unit 21 reduces the power supplied to the first heater 15 until the heating device 3 has finished starting up (S4: NO). When the heating device 3 has finished starting up (S4: YES), the control unit 21 turns off the first heater 15 (S5). After startup is complete, the second heater 16 heats the heating element 14b to maintain it at the optimal temperature for heating, and the heating element 14b heats the heating element 14a to maintain it at the optimal temperature for heating.

[0063] In this embodiment, the heating device 3 has the first heater 15 and the second heater 16 turned on at startup, and the first heater 15 is turned off while the second heater 16 remains on when startup is complete. At startup, the first heater 15, which has a smaller heat output than the second heater 16, heats up instantaneously, allowing the heating elements 14a and 14b to reach the optimal temperature for heating in a short time, thereby shortening the startup time. When startup is complete, the first heater 15, which has a shorter lifespan than the second heater 16, is turned off, extending the lifespan of the first heater 15. Therefore, the heating device 3 can improve both its startup performance and durability.

[0064] The heating device 3 has a gap L [mm] between the first heating structure 8 and the second heating structure 9 that satisfies Equation 1. Gas is exhausted from the gap between the first heating structure 8 and the second heating structure 9, and hydrogen-based gas spreads throughout the gap, allowing sufficient hydrogen to be absorbed by the heating element 14, thereby improving the amount of heat generated by the heating element 14. In addition, the amount of heat radiated to the surroundings from the heating surfaces of the first heating structure 8 and the second heating structure 9 is reduced, reducing heat loss due to radiation, allowing the heating element 14 to be heated efficiently, and reducing the power supplied to the first heater 15 and the second heater 16. Therefore, the heating device 3 can improve the COP.

[0065] The heating device 3 includes a spacer 22 between the first heating structure 8 and the second heating structure 9, the spacer having a coefficient of linear expansion less than or equal to that of the heating element 14. Compared to the case where the coefficient of linear expansion of the spacer 22 is greater than that of the heating element 14, the thermal stress at the contact surface between the heating element 14 and the spacer 22 is reduced, thereby preventing damage to the heating element 14 at the contact surface.

[0066] The first heating structure 8 has a heating element 14a and a first heater 15, with the heating element 14a arranged to surround the first heater 15. The second heating structure 9 has a heating element 14b and a second heater 16, with the heating element 14b arranged to surround the second heater 16. The heating element 14a of the first heating structure 8 and the heating element 14b of the second heating structure 9 are heated by the heat generated by each other. Therefore, the heating device 3 can efficiently raise the temperature of the heating elements 14a and 14b, further improving its start-up performance.

[0067] The first heater 15 is a lamp heater, and the second heater 16 is a sheathed heater or a ceramic heater. The lamp heater has a steep start-up characteristic and excellent starting performance. The sheathed heater or ceramic heater has a long lifespan and excellent durability. The heating device 3 can ensure both starting performance and durability.

[0068] The present invention is not limited to the embodiments described above, and can be modified as appropriate without departing from the spirit of the invention. [Explanation of symbols]

[0069] 3. Heating device 5. Airtight container 8. First Heat-Generating Structure 9. Second heating structure 14 Heating element 15. First heater 16. Second heater 21 Control Unit 22 Spacers 61 Support 62 Multilayer film 71 1st layer 72 2nd layer

Claims

1. A sealed container to which hydrogen-containing hydrogen gas is supplied, A first heating structure is provided inside the sealed container, and has a first heater that generates heat when electricity is supplied to it. The heating element generates heat by the absorption and release of hydrogen, and the second heater generates heat by the supply of electricity, and the plurality of second heating elements are provided inside the sealed container and arranged to surround the first heating element, A control unit that controls the on / off state of the first heater and the second heater, and Equipped with, The heating element comprises a support made of a hydrogen storage metal, a hydrogen storage alloy, or a proton conductor, and a multilayer film provided on the support. The multilayer film comprises a first layer less than 1000 nm thick, formed from a hydrogen-absorbing metal or hydrogen-absorbing alloy, and a second layer less than 1000 nm thick, formed from a hydrogen-absorbing metal, hydrogen-absorbing alloy, or ceramic different from the first layer. The second heating structure has a configuration in which the heating element is arranged to surround the second heater. The heat capacity of the first heater is smaller than the heat capacity of the second heater. The control unit is a heating device that performs startup control by turning on the first heater and the second heater at startup, and turning off the first heater while keeping the second heater on when startup is complete.

2. The first heating structure and the second heating structure have a cylindrical outer shape. The heating device according to claim 1, wherein a gap L [mm] satisfying formula 1 is provided between the first heating structure and the second heating structure. {C / (30.9Ks)×(πR / 2) / a} （１／２） ≦L≦1.2 (Equation 1) However, C: vacuum conductance [cm] in the gap between the first heating structure and the second heating structure. ３ / s] Ks: Correction coefficient R: Diameter of the second heating structure [mm] a: Dimensions of the second heating structure in the direction along the long side of the flow channel cross-section [mm]

3. The heating device according to claim 1, further comprising a spacer provided between the first heating structure and the second heating structure, the spacer having a coefficient of linear expansion less than or equal to the coefficient of linear expansion of the heating element or the first heater.

4. The heating device according to claim 1, wherein the first heating structure has the heating element, and the heating element is arranged to surround the first heater.

5. The first heater is a lamp heater, The heating device according to claim 1, wherein the second heater is a sheathed heater or a ceramic heater.

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