Hydrogen heating apparatus for blast furnaces, hydrogen heating method for blast furnaces, and blast furnace operation method

Abstract

To provide a novel hydrogen heating apparatus for blast furnace, a hydrogen heating method for blast furnace and a blast furnace operation method in which a generation amount of CO2 can be suppressed even if hydrogen-based gas is used as reducing gas.SOLUTION: A hydrogen heating apparatus for blast furnace 11 comprises: a sealed container 15 into which hydrogen-based gas is introduced; a heat generator 14 which is provided inside sealed container 15, and generates heat by storage and emission of hydrogen; and a temperature adjustment part which adjusts the temperature of the heat generator 14; where the heat generator 14 has one or more laminates 14a that consist of a support body 61 which is formed of at least any one of a porous body, a hydrogen permeable membrane, and a proton conductor, and a multilayer film 62 supported by the support body 61, the multilayer film 62 has: a first layer which is formed of hydrogen storage metal or hydrogen storage alloy, and has the thickness of less than 1000 nm; and a second layer which is formed of hydrogen storage metal, hydrogen storage alloy or ceramics different from the first layer, and has the thickness of less than 1000 nm, and hydrogen-based gas is heated to a predetermined temperature by heating by heat generator 14.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a hydrogen heating apparatus for blast furnaces, a hydrogen heating method for blast furnaces, and a blast furnace operation method. [Background technology]

[0002] Generally, in integrated steelworks equipped with blast furnaces, converters, rolling mills, and energy supply facilities, coal (coke) is used as the primary energy source. The majority of the coal is consumed in the ironmaking process (blast furnaces, coke ovens, and sintering machines), and the waste heat from by-product gases generated in the ironmaking process is effectively utilized as an energy source for various facilities within the steelworks.

[0003] On the other hand, in the context of global environmental problems, there is a demand to reduce CO2 emissions. Of the CO2 emitted from the entire steelworks, the majority is generated from the ironmaking process, with the blast furnace emitting the largest amount. For this reason, measures to improve reduction efficiency, such as improving the reducibility of the raw materials used in the blast furnace and optimizing the distribution of top charges, are being considered to enable operation at a low reducing agent ratio. Specifically, reducing the reducing agent (coke) and replacing it partially or entirely with hydrogen-containing hydrogen-based gases are being considered.

[0004] The coke reduction reaction using coke in conventional ironmaking processes (a reaction that oxidizes carbon to CO2 and reduces Fe2O3 to Fe) is an exothermic reaction. This reduction reaction is characterized by its spontaneous nature.

[0005] On the other hand, hydrogen reduction using hydrogen instead of coke (a reaction that oxidizes H2 to H2O and reduces Fe2O3 to Fe) is an endothermic reaction. Because it is an endothermic reaction, the reduction rate decreases. Furthermore, improving the reduction efficiency of the blast furnace reduces the calorific value of the gas emitted from the blast furnace. For this reason, if the amount of energy supplied to the various facilities of the steelworks falls below the amount of demand, energy must be procured from external sources.

[0006] Non-Patent Document 1 describes that hydrogen injection in the ironmaking process causes a temperature drop near 200 to 600 °C in the blast furnace. Since the reaction progresses directly below the iron ore inlet, the temperature drop near the inlet is particularly significant.

[0007] Patent Document 1 also describes that in order to maintain the calorific value of a blast furnace that performs hydrogen reduction in the ironmaking process, the injection amount of the hydrogen-based gas is determined based on the action line obtained in advance.

[0008] Patent Document 2 also describes that in the ironmaking process, instead of coke, a heated hydrogen-based gas is used as a reducing gas. By using a heated hydrogen-based gas in the ironmaking process, the injection amount of the hydrogen-based gas can be increased and the reduction efficiency can be improved.

Prior Art Documents

Patent Documents

[0009]

Patent Document 1

Patent Document 2

Non-Patent Documents

[0010]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0011] As described in Patent Document 2 above, when using heated hydrogen-based gas as a reducing gas in the ironmaking process, direct heating of the hydrogen-based gas carries the risk of ignition because the ignition point of hydrogen is low at 500°C, so indirect heating is being considered. Generally, indirect heating reduces heat transfer efficiency, so heating hydrogen-based gas consumes more energy than direct heating. Also, since a large amount of hydrogen is consumed, a large amount of hydrogen-based gas needs to be heated, and this heating requires a huge amount of energy. Thus, when some or all of the reducing agent is replaced with hydrogen-based gas in order to suppress the amount of CO2 generated, a large amount of energy is consumed to heat the hydrogen-based gas, and as a result, it is difficult to suppress the amount of CO2 generated.

[0012] Therefore, the present invention aims to provide a novel hydrogen heating apparatus for blast furnaces, a hydrogen heating method for blast furnaces, and a blast furnace operation method that can suppress the amount of CO2 generated even when a hydrogen-based gas is used as the reducing gas. [Means for solving the problem]

[0013] The hydrogen heating apparatus for a blast furnace according to the present invention is a hydrogen heating apparatus for a blast furnace that heats a hydrogen-containing hydrogen-based gas and supplies it to a blast furnace, comprising: a sealed container into which the hydrogen-based gas is introduced; a heating element provided inside the sealed container and generating heat by the absorption and release of the hydrogen; and a temperature control unit for adjusting the temperature of the heating element, wherein the heating element has one or more laminates comprising a support made of at least one of a porous material, a hydrogen permeable membrane, and a proton conductor, and a multilayer film supported on the support, wherein the multilayer film has a first layer made of a hydrogen-absorbing metal or hydrogen-absorbing alloy with a thickness of less than 1000 nm, and a second layer made of a hydrogen-absorbing metal, hydrogen-absorbing alloy, or ceramic different from the first layer with a thickness of less than 1000 nm, and the hydrogen-based gas is heated to a predetermined temperature by heating with the heating element.

[0014] The hydrogen heating method for a blast furnace according to the present invention is a hydrogen heating method for a blast furnace that heats a hydrogen-containing hydrogen-based gas and supplies it to a blast furnace, comprising: an introduction step in which the hydrogen-based gas is introduced into a sealed container; a temperature control step in which the temperature of a heating element provided inside the sealed container is adjusted by a temperature control unit; and a heat generation step in which heat is generated from the heating element by the absorption and release of hydrogen in the heating element, wherein the heating element has one or more laminates comprising a support made of at least one of a porous material, a hydrogen permeable membrane, and a proton conductor, and a multilayer film supported on the support, wherein the multilayer film has a first layer made of a hydrogen-absorbing metal or hydrogen-absorbing alloy with a thickness of less than 1000 nm, and a second layer made of a hydrogen-absorbing metal, hydrogen-absorbing alloy, or ceramic different from the first layer with a thickness of less than 1000 nm, and the hydrogen-based gas is heated to a predetermined temperature by heating with the heating element.

[0015] The blast furnace operation method according to the present invention is a blast furnace operation method that includes a step of blowing a hydrogen-based gas into the inside of the blast furnace from the tuyeres of the blast furnace as a reducing gas, wherein the hydrogen-based gas is a hydrogen-based gas heated by the above-mentioned hydrogen heating device for blast furnaces. [Effects of the Invention]

[0016] According to the present invention, since hydrogen-based gases can be heated without consuming a large amount of energy, the amount of CO2 generated can be suppressed accordingly. Therefore, by using the hydrogen-based gas heated in this way as a reducing gas in a blast furnace, the amount of CO2 generated can be suppressed even when using hydrogen-based gas as a reducing gas. [Brief explanation of the drawing]

[0017] [Figure 1] This is a schematic diagram of a hydrogen heating device for a blast furnace according to the first embodiment, installed in a blast furnace. [Figure 2] This is a cross-sectional view showing the structure of the heating element. [Figure 3] This is a cross-sectional view showing the structure of a laminate having a first layer and a second layer. [Figure 4]This is an explanatory diagram to illustrate the generation of excess heat. [Figure 5] This is an explanatory diagram illustrating the operation of a hydrogen heating device for blast furnaces. [Figure 6] This is a cross-sectional view showing the structure of a first modified heating element in which multiple laminates are stacked. [Figure 7] This is an explanatory diagram for illustrating the heating element in the first modified example. [Figure 8] This is an explanatory diagram illustrating a second modified heating element having multilayer films on both sides. [Figure 9] This is an explanatory diagram illustrating a third modified heating element having a first layer, a second layer, and a third layer. [Figure 10] This is an explanatory diagram illustrating a fourth modified heating element having a first layer, a second layer, a third layer, and a fourth layer. [Figure 11] This graph shows the relationship between the ratio of the thicknesses of each layer in a multilayer film and excess heat. [Figure 12] This graph shows the relationship between the number of layers in a multilayer film and excess heat. [Figure 13] This graph shows the relationship between the materials used in multilayer films and excess heat. [Figure 14] This is a cross-sectional view of a heating element formed in a bottomed cylindrical shape. [Figure 15] This is a schematic diagram of the fifth modified example of a hydrogen heating apparatus for a blast furnace. [Figure 16] This is a cross-sectional view of a heating element having a columnar support. [Figure 17] This is a schematic diagram of the sixth modified example of a hydrogen heating apparatus for a blast furnace. [Figure 18] This is a schematic diagram of the seventh modified example of a hydrogen heating apparatus for a blast furnace. [Figure 19] This is a schematic diagram of the eighth modified example of a hydrogen heating apparatus for a blast furnace. [Figure 20] This is an explanatory diagram illustrating a nozzle section having multiple nozzle openings. [Figure 21] This is a cross-sectional view of a cylindrical heating element with open ends. [Figure 22] This is a schematic diagram of the ninth modified example of a hydrogen heating apparatus for a blast furnace. [Figure 23] This is a schematic diagram of the 10th modified example of a hydrogen heating apparatus for a blast furnace. [Figure 24] This is an explanatory diagram illustrating the first mode of the hydrogen pressure control unit. [Figure 25] This is an explanatory diagram illustrating the second mode of the hydrogen pressure control unit. [Figure 26] This is a schematic diagram of the 11th modified example of a hydrogen heating apparatus for a blast furnace. [Figure 27] This is an explanatory diagram illustrating the operation of a hydrogen heating device for a blast furnace in the 11th modified example. [Figure 28] This is a cross-sectional view of the 12th modified example of a hydrogen heating apparatus for a blast furnace. [Figure 29] This graph shows the relationship between hydrogen permeation rate, hydrogen supply pressure, and sample temperature in a reference experiment. [Figure 30] This graph shows the relationship between sample temperature and input power in a reference experiment. [Figure 31] This graph shows the relationship between the heating element temperature and excess heat in Experimental Example 26. [Figure 32] This graph shows the relationship between the heating element temperature and excess heat in Experimental Example 27. [Figure 33] This is a schematic diagram of a hydrogen heating apparatus for a blast furnace according to a second embodiment. [Figure 34] This is a schematic diagram of a hydrogen heating apparatus for a blast furnace according to the third embodiment. [Figure 35] This is an exploded perspective view of the heat-generating structure. [Modes for carrying out the invention]

[0018] [First Embodiment] As shown in Figure 1, the blast furnace equipment 10 comprises a blast furnace hydrogen heating device 11 and a blast furnace 12. During blast furnace operation, the blast furnace equipment 10 heats a hydrogen-containing hydrogen gas with the heat generated by the heating element 14 of the blast furnace hydrogen heating device 11, and supplies the heated hydrogen-containing gas as a reducing gas from the blast furnace hydrogen heating device 11 to the blast furnace 12, blowing it into the interior of the blast furnace 12 through the tuyeres of the blast furnace 12.

[0019] For example, the blast furnace 12 is not particularly limited, and a blast furnace described in Patent Document 1 or Patent Document 2 can be used. For example, iron-based raw materials are inserted into the blast furnace from the top of the furnace, and hydrogen-based gas heated as a reducing gas is blown in along with hot air from tuyeres provided in the blast furnace.

[0020] The blast furnace hydrogen heating apparatus 11 comprises a heating element 14, a sealed container 15, a temperature control unit 16, a hydrogen flow line 17 having an introduction line 29 and an outlet line 30, and a control unit 18. The heating element 14 is housed in the sealed container 15 and is heated by a heater 16b of the temperature control unit 16, which will be described later. The heating element 14 generates heat (hereinafter referred to as excess heat) above the heating temperature of the heater 16b by absorbing and releasing hydrogen. By generating excess heat, the heating element 14 heats the permeating hydrogen-based gas to a temperature within the range of, for example, 50°C to 1000°C. In this example, the heating element 14 is formed in the shape of a plate with a front and a back surface. The detailed configuration of the heating element 14 will be described later using separate drawings.

[0021] The sealed container 15 is a hollow container that houses the heating element 14 inside. The sealed container 15 is made of, for example, stainless steel. In this example, the sealed container 15 has a shape in which the longitudinal direction is parallel to the direction perpendicular to the surface or back surface of the heating element 14. Inside the sealed container 15, there is an installation section 20 for installing the heating element 14.

[0022] The sealed container 15 has a first chamber 21 and a second chamber 22 inside, separated by a heating element 14. The first chamber 21 is formed by the surface, which is one side of the heating element 14, and the inner surface of the sealed container 15. The first chamber 21 has an inlet 23 that connects to the introduction line 29 of the hydrogen flow line 17. Hydrogen-based gas flowing through the hydrogen flow line 17 is introduced into the first chamber 21 through the inlet 23. The second chamber 22 is formed by the back surface, which is the other side of the heating element 14, and the inner surface of the sealed container 15. The second chamber 22 has an outlet 24 that connects to the outlet line 30 of the hydrogen flow line 17. The hydrogen-based gas in the second chamber 22 is supplied from the second chamber 22 to the blast furnace 12 via the outlet line 30 connected to the outlet 24.

[0023] The first chamber 21 is pressurized by the introduction of a hydrogen-based gas. The second chamber 22 is depressurized by the release of the hydrogen-based gas. As a result, the hydrogen pressure in the first chamber 21 is higher than the hydrogen pressure in the second chamber 22. The hydrogen pressure in the first chamber 21 is, for example, 100 [kPa]. The hydrogen pressure in the second chamber 22 is, for example, 1 × 10⁻⁶ -4 The pressure is set to be less than or equal to [Pa]. The second chamber 22 may be in a vacuum state. Thus, the hydrogen pressure is different in the first chamber 21 and the second chamber 22. For this reason, a pressure difference is created inside the sealed container 15 on both sides of the heating element 14.

[0024] When a pressure difference occurs on both sides of the heating element 14, hydrogen molecules contained in the hydrogen-based gas are adsorbed on one side (front surface) of the heating element 14 that is positioned on the high-pressure side, and these hydrogen molecules dissociate into two hydrogen atoms. The dissociated hydrogen atoms penetrate into the interior of the heating element 14. In other words, hydrogen is absorbed into the heating element 14. The hydrogen atoms diffuse through the interior of the heating element 14. On the other side (back surface) of the heating element 14 that is positioned on the low-pressure side, the hydrogen atoms that have passed through the heating element 14 recombine and are released as hydrogen molecules. In other words, hydrogen is released from the heating element 14.

[0025] In this way, the heating element 14 allows hydrogen to permeate from the high-pressure side to the low-pressure side. "Permeation" means that hydrogen is absorbed on one side of the heating element and released from the other side. As will be explained in more detail later, the heating element 14 generates heat by absorbing hydrogen and also by releasing hydrogen. Therefore, the heating element 14 generates heat through the permeation of hydrogen. In the following explanation, "hydrogen permeation" of the heating element may be referred to as "hydrogen-based gas permeation."

[0026] Inside the first chamber 21, there is a pressure sensor (not shown) for detecting the pressure inside the first chamber 21. Inside the second chamber 22, there is a pressure sensor (not shown) for detecting the pressure inside the second chamber 22. Each pressure sensor in the first chamber 21 and the second chamber 22 is electrically connected to the control unit 18 and outputs a signal corresponding to the detected pressure to the control unit 18.

[0027] The temperature control unit 16 adjusts the temperature of the heating element 14 and maintains it at a temperature suitable for heating. The temperature suitable for heating in the heating element 14 is, for example, within the range of 50°C to 1000°C. The temperature control unit 16 has a temperature sensor 16a and a heater 16b. The temperature sensor 16a detects the temperature of the heating element 14. The temperature sensor 16a is, for example, a thermocouple and is installed in the installation section 20 of the sealed container 15. The temperature sensor 16a is electrically connected to the control unit 18 and outputs a signal corresponding to the detected temperature to the control unit 18.

[0028] The heater 16b heats the heating element 14. The heater 16b is, for example, an electric resistance heating wire, which is wrapped around the outer circumference of the sealed container 15. The heater 16b is electrically connected to the power supply 26 and generates heat when power is input from the power supply 26. The heater 16b may also be an electric furnace positioned to cover the outer circumference of the sealed container 15.

[0029] The hydrogen distribution line 17 is located outside the sealed container 15 and introduces hydrogen-containing hydrogen gas from the outside to the inside of the sealed container 15, and discharges heated hydrogen-containing gas from the inside to the outside of the sealed container 15. In addition to the introduction line 29 and the discharge line 30, the hydrogen distribution line 17 includes a hydrogen tank 28 and a filter 31. Although not shown in Figure 1, the blast furnace hydrogen heating device 11 is equipped with a supply line for supplying hydrogen-containing gas to the hydrogen tank 28 and an exhaust line for exhausting hydrogen-containing gas from the hydrogen distribution line 17. For example, when the blast furnace hydrogen heating device 11 starts operation, hydrogen-containing gas is supplied from the supply line to the hydrogen tank 28, and when the blast furnace hydrogen heating device 11 stops operation, the hydrogen-containing gas from the hydrogen distribution line 17 is exhausted to the exhaust line.

[0030] Hydrogen tank 28 stores hydrogen-based gas. Hydrogen-based gas is a gas containing isotopes of hydrogen. At least one of deuterium gas or light hydrogen gas is used as the hydrogen-based gas. Light hydrogen gas includes a naturally occurring mixture of light hydrogen and deuterium, i.e., a mixture in which the abundance of light hydrogen is 99.985% and the abundance of deuterium is 0.015%.

[0031] The introduction line 29 connects the hydrogen tank 28 to the inlet 23 of the first chamber 21 and introduces the hydrogen-based gas from the hydrogen tank 28 into the first chamber 21. The introduction line 29 has a pressure regulating valve 32. The pressure regulating valve 32 reduces the pressure of the hydrogen-based gas supplied from the hydrogen tank 28 to a predetermined pressure. The pressure regulating valve 32 is electrically connected to the control unit 18. The introduction line 29 has a pump 33. The pump 33 introduces the hydrogen-based gas from the hydrogen tank 28 into the first chamber 21. For example, a metal bellows pump is used as the pump 33. The pump 33 is electrically connected to the control unit 18.

[0032] The discharge line 30 connects the outlet 24 of the second chamber 22 to the blast furnace 12 and supplies the hydrogen-based gas that has permeated from the first chamber 21 to the second chamber 22 via the heating element 14 to the blast furnace 12.

[0033] The filter 31 installed in the introduction line 29 is for removing impurities contained in the hydrogen-based gas. Here, the amount of hydrogen that permeates through the heating element 14 (hereinafter referred to as hydrogen permeation) is determined by the temperature of the heating element 14, the pressure difference on both sides of the heating element 14, and the surface condition of the heating element 14. If the hydrogen-based gas contains impurities, the impurities may adhere to the surface of the heating element 14, and the surface condition of the heating element 14 may deteriorate. If impurities adhere to the surface of the heating element 14, the adsorption and dissociation of hydrogen molecules on the surface of the heating element 14 is inhibited, and the hydrogen permeation decreases.

[0034] Substances that inhibit the adsorption and dissociation of hydrogen molecules on the surface of the heating element 14 include, for example, water (including water vapor), hydrocarbons (methane, ethane, methanol, ethanol, etc.), C, S, and Si. Water is thought to be released from the inner wall of the sealed container 15, or from the reduction of an oxide film contained in components provided inside the sealed container 15 by hydrogen. Hydrocarbons, C, S, and Si are thought to be released from various components provided inside the sealed container 15. Therefore, the filter 31 removes at least water (including water vapor), hydrocarbons, C, S, and Si as impurities. By removing impurities contained in the hydrogen-based gas, the filter 31 suppresses the decrease in hydrogen permeation in the heating element 14.

[0035] The control unit 18 controls the operation of each part of the blast furnace hydrogen heating apparatus 11. The control unit 18 mainly includes, for example, a central processing unit, and storage units such as read-only memory and random access memory. The central processing unit performs various calculations using, for example, programs and data stored in the storage units.

[0036] The control unit 18 is electrically connected to the temperature sensor 16a, the power supply 26, the pressure regulating valve 32, and the pump 33. The control unit 18 controls the output of excess heat generated by the heating element 14 by adjusting the input power of the heater 16b, the pressure of the sealed container 15, and the like.

[0037] The control unit 18 functions as an output control unit that controls the output of the heater 16b based on the temperature detected by the temperature sensor 16a. The control unit 18 maintains the heating element 14 at an appropriate temperature for heating by controlling the power supply 26 and adjusting the input power to the heater 16b.

[0038] The control unit 18 adjusts the pressure difference of hydrogen generated between the first chamber 21 and the second chamber 22 by controlling the pressure regulating valve 32 and the pump 33 based on the pressure detected by the respective pressure sensors (not shown) provided in the first chamber 21 and the second chamber 22.

[0039] The control unit 18 performs a hydrogen storage step in which hydrogen is absorbed into the heating element 14, and a hydrogen release step in which hydrogen is released from the heating element 14. In this embodiment, the control unit 18 performs the hydrogen storage step and the hydrogen release step simultaneously by generating a hydrogen pressure difference between the first chamber 21 and the second chamber 22. The control unit 18 introduces a hydrogen-based gas from the introduction line 29 into the first chamber 21 and discharges the hydrogen-based gas from the second chamber 22 to the discharge line 30, thereby making the first chamber 21 more pressure than the second chamber 22, and maintaining a state in which hydrogen is absorbed on the surface of the heating element 14 and hydrogen is released on the back surface of the heating element 14 simultaneously.

[0040] In this disclosure, "simultaneous" means completely simultaneous or within a time frame so short that it can be considered substantially simultaneous. By performing the hydrogen storage process and the hydrogen release process simultaneously, hydrogen continuously permeates the heating element 14, thereby efficiently generating excess heat in the heating element 14. The control unit 18 may also alternately repeat the hydrogen storage process and the hydrogen release process. That is, the control unit 18 may first perform the hydrogen storage process to cause the heating element 14 to absorb hydrogen, and then perform the hydrogen release process to release the hydrogen absorbed in the heating element 14. By alternately repeating the hydrogen storage process and the hydrogen release process in this way, excess heat can also be generated from the heating element 14.

[0041] The blast furnace hydrogen heating device 11 generates a hydrogen pressure difference between the first chamber 21 and the second chamber 22, which are arranged with a heating element 14 in between. This causes hydrogen to permeate the heating element 14, generating excess heat. As the hydrogen-based gas permeates the heating element 14, it is heated by the excess heat generated by the heating element 14. The thicker the heating element 14 and the longer the distance the hydrogen-based gas has to permeate it, the longer the time it is heated by the excess heat generated by the heating element 14, and consequently, the higher its temperature when it is discharged into the second chamber 22 after passing through the heating element 14. The hydrogen-based gas is heated to a predetermined temperature by the heating of the heating element 14.

[0042] Next, the detailed structure of the heating element 14 will be described using Figures 2 and 3. As shown in Figure 2, the heating element 14 has a laminate 14a having a support 61 and a multilayer film 62.

[0043] Here, for example, a hydrogen-based gas at about 25°C permeates through the heating element 14, causing the hydrogen-based gas to be heated by the heating element 14. After passing through the heating element 14, the hydrogen-based gas becomes 50°C to 1000°C, preferably 600°C to 1000°C. In this embodiment, Figure 2 shows the case where the hydrogen-based gas permeates from the support 61 at the left end of the paper to the multilayer film 62 at the right end of the paper. However, the present invention is not limited to this, and the hydrogen-based gas may also permeate from the multilayer film 62 at the right end of the paper to the support 61 at the left end of the paper.

[0044] The support 61 is formed of at least one of a porous body, a hydrogen permeable membrane, and a proton conductor. In this example, the support 61 is formed in a plate shape having a front surface and a back surface. The porous body has pores of a size that allows the passage of hydrogen-based gases. The porous body is formed of, for example, a metal, a non-metal, ceramics, or the like. 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 (hereinafter referred to as the exothermic reaction). The hydrogen permeable membrane is formed of, for example, a hydrogen storage metal or a hydrogen storage alloy. As the hydrogen storage metal, Ni, Pd, V, Nb, Ta, Ti, or the like is used. As the hydrogen storage alloy, LaNi5, CaCu5, MgZn2, ZrNi2, ZrCr2, TiFe, TiCo, Mg2Ni, Mg2Cu, or the like is used. The hydrogen permeable membrane includes those having a mesh-like sheet. As the proton conductor, BaCeO3-based (e.g., Ba(Ce 0.95 Y 0.05 )O 3-6 ), SrCeO3-based (e.g., Sr(Ce 0.95 Y 0.05 )O 3-6 ), CaZrO3-based (e.g., CaZr 0.95 Y 0.05 O 3-α ), SrZrO3-based (e.g., SrZr 0.9 Y 0.1 O 3-α ), β Al2O3, β Ga2O3, or the like is used.

[0045] As shown in Figure 3, the multilayer film 62 is provided on the support 61. The multilayer film 62 is formed of a first layer 71 made of a hydrogen-absorbing metal or hydrogen-absorbing alloy, and a second layer 72 made of a hydrogen-absorbing metal, hydrogen-absorbing alloy, or ceramic different from the first layer 71. A heterogeneous material interface 73, described later, is formed between the support 61, the first layer 71, and the second layer 72. In Figure 3, the multilayer film 62 is formed by alternately stacking the first layer 71 and the second layer 72 in this order on one surface (e.g., the front) of the support 61. The first layer 71 and the second layer 72 each consist of 5 layers. The number of layers in each of the first layer 71 and the second layer 72 may be changed as appropriate. The multilayer film 62 may also be formed by alternately stacking the second layer 72 and the first layer 71 in this order on the surface of the support 61. The multilayer film 62 only needs to have one or more first layers 71 and one or more second layers 72, and to have one or more dissimilar material interfaces 73 formed.

[0046] The first layer 71 is formed from, for example, Ni, Pd, Cu, Mn, Cr, Fe, Mg, Co, or an alloy thereof. Preferably, the alloy forming the first layer 71 is an alloy consisting of two or more of Ni, Pd, Cu, Mn, Cr, Fe, Mg, and Co. As the alloy forming the first layer 71, an alloy in which additive elements are added to Ni, Pd, Cu, Mn, Cr, Fe, Mg, or Co may be used.

[0047] The second layer 72 is formed from, for example, Ni, Pd, Cu, Mn, Cr, Fe, Mg, Co, alloys thereof, or SiC. The alloy forming the second layer 72 is preferably an alloy consisting of two or more of Ni, Pd, Cu, Mn, Cr, Fe, Mg, and Co. As the alloy forming the second layer 72, an alloy in which additive elements are added to Ni, Pd, Cu, Mn, Cr, Fe, Mg, or Co may also be used.

[0048] When expressing the combination of the first layer 71 and the second layer 72 as "first layer 71 - second layer 72 (second layer 72 - first layer 71)", the elements are preferably Pd-Ni, Ni-Cu, Ni-Cr, Ni-Fe, Ni-Mg, and Ni-Co. If the second layer 72 is made of ceramics, then it is preferable that "first layer 71 - second layer 72" is Ni-SiC.

[0049] As shown in Figure 4, the heterogeneous material interface 73 allows hydrogen atoms to pass through. Figure 4 is a schematic diagram showing how hydrogen atoms in the metal lattice of the first layer 71 move through the heterogeneous material interface 73 into the metal lattice of the second layer 72 in the first layer 71 and second layer 72 formed by a face-centered cubic hydrogen-absorbing metal. Hydrogen is light and is known to quantum diffuse by hopping between sites (octohedral and tetrahedral sites) occupied by hydrogen in a given material A and material B. For this reason, hydrogen absorbed into the heating element 14 quantum diffuses by hopping within the multilayer film 62. In the heating element 14, hydrogen permeates through the first layer 71, the heterogeneous material interface 73, and the second layer 72 by quantum diffusion.

[0050] The thickness of the first layer 71 and the second layer 72 are preferably less than 1000 nm each. If the thicknesses of the first layer 71 and the second layer 72 are 1000 nm or more, hydrogen will have difficulty permeating through the multilayer film 62. Furthermore, by having the thicknesses of the first layer 71 and the second layer 72 less than 1000 nm each, it is possible to maintain a nanostructure that does not exhibit bulk properties. It is more preferable that the thicknesses of the first layer 71 and the second layer 72 are less than 500 nm each. By having the thicknesses of the first layer 71 and the second layer 72 less than 500 nm each, it is possible to maintain a nanostructure that does not exhibit bulk properties at all.

[0051] Next, an example of a method for manufacturing the heating element 14 will be described. In this case, a plate-shaped support 61 is prepared, and using a vapor deposition apparatus, a hydrogen-absorbing metal or hydrogen-absorbing alloy that will become the first layer 71 and the second layer 72 is brought into a gas phase state, 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 forms a laminate 14a having a multilayer film 62 on the surface of the support 61. It is preferable that the first layer 71 and the second layer 72 are deposited continuously under vacuum conditions. As a result, no native oxide film is formed between the first layer 71 and the second layer 72, and only a heterogeneous material interface 73 is formed. As the vapor deposition apparatus, a physical vapor deposition apparatus that deposits the hydrogen-absorbing metal or hydrogen-absorbing alloy by a physical method is used. As the physical vapor deposition apparatus, sputtering apparatuses, vacuum vapor deposition apparatuses, and CVD (Chemical Vapor Deposition) apparatuses are preferred. Alternatively, a hydrogen-absorbing metal or hydrogen-absorbing alloy may be deposited on the surface of the support 61 by electroplating, and the first layer 71 and the second layer 72 may be formed alternately.

[0052] As shown in Figure 5, the heating element 14 is configured such that, for example, the support 61 of the laminate 14a at one end is positioned on the first chamber 21 side (high pressure side), and the multilayer film 62 of the laminate 14a at the other end is positioned on the second chamber 22 side (low pressure side). Due to the hydrogen pressure difference between the first chamber 21 and the second chamber 22, the hydrogen introduced into the first chamber 21 permeates through the inside of the heating element 14, in the order of support 61 and then multilayer film 62, and moves to the second chamber 22. The heating element 14 generates excess heat when hydrogen permeates through the multilayer film 62, that is, through the absorption of hydrogen into the multilayer film 62 and the release of hydrogen from the multilayer film 62. Alternatively, the heating element 14 may have the support 61 positioned on the second chamber 22 side (low pressure side) and the multilayer film 62 positioned on the first chamber 21 side (high pressure side).

[0053] The heating element 14 heats the permeating hydrogen-based gas with the excess heat it generates. Since the heating element 14 uses hydrogen to generate heat, it does not produce greenhouse gases such as carbon dioxide, making it a clean thermal energy source. Furthermore, the hydrogen used can be produced from water, making it inexpensive. Moreover, the heat generated by the heating element 14 is considered safe because, unlike nuclear fission reactions, there is no chain reaction. Therefore, the blast furnace hydrogen heating device 11 can heat the hydrogen-based gas using such a heating element 14 as a thermal energy source, thereby supplying the hydrogen-based gas heated using an inexpensive, clean, and safe thermal energy source to the blast furnace 12 as a reducing gas.

[0054] In the hydrogen heating device 11 for blast furnaces of this embodiment, since it is possible to heat hydrogen-based gas without consuming a large amount of energy, the amount of CO2 generated can be suppressed accordingly. Therefore, in the hydrogen heating device 11 for blast furnaces, when the blast furnace is in operation, the amount of CO2 generated can be suppressed even when hydrogen-based gas is used as a reducing gas in the blast furnace 12 by using the hydrogen-based gas heated in this way as a reducing gas in the blast furnace 12.

[0055] The present invention is not limited to the first embodiment described above, and can be modified as appropriate without departing from the spirit of the invention. Hereinafter, modifications of the first embodiment will be described. In the drawings and descriptions of the modifications, the same reference numerals are used for components and members that are the same or equivalent as those in the first embodiment. Descriptions that overlap with the first embodiment will be omitted as appropriate, and the differences from the first embodiment will be described in detail.

[0056] [First variation] As shown in Figure 6, the heating element 19 has a structure in which multiple laminates 14a, each having a support 61 and a multilayer film 62, are stacked. Furthermore, the thickness of the heating element 19 through which the hydrogen-based gas permeates is adjusted by changing the number of stacks of the laminates 14a. Specifically, the more stacks of the laminates 14a there are, the thicker the heating element 19 becomes, and the longer the distance the hydrogen-based gas has to permeate through the heating element 19 becomes. Therefore, the more stacks of the laminates 14a there are, the higher the temperature of the hydrogen-based gas after it has permeated through the heating element 19. On the other hand, the fewer stacks of the laminates 14a there are, the thinner the heating element 19 becomes, and the shorter the distance the hydrogen-based gas has to permeate through the heating element 19 becomes. Therefore, the fewer stacks of the laminates 14a there are, the lower the temperature of the hydrogen-based gas after it has permeated through the heating element 19 becomes.

[0057] When setting the number of layers of the laminate 14a, it is desirable to determine in advance, based on past operational experience, the relationship between the temperature of the hydrogen-based gas after it has permeated the heating element 19 and the number of layers of the laminate 14a, and then determine the number of layers of the laminate 14a so that the hydrogen-based gas reaches the desired temperature.

[0058] The heating element 19 is constructed by placing a support 61 of a second laminate 14a on the multilayer film 62 of a first laminate 14a, and then placing a support 61 of a third laminate 14a on the multilayer film 62 of the second laminate 14a, and so on, with multiple laminates 14a being stacked sequentially. As a result, the heating element 19 shown in Figure 6 has a configuration in which the support 61 and multilayer film 62 are arranged alternately from left to right, such as support 61, multilayer film 62, support 61 and multilayer film 62. In this embodiment, the case where a hydrogen-based gas permeates from the support 61 at the left end of the page to the multilayer film 62 at the right end of the page is illustrated, but the present invention is not limited to this, and the hydrogen-based gas may also permeate from the multilayer film 62 at the right end of the page to the support 61 at the left end of the page.

[0059] A heating element 19 can be manufactured by preparing multiple laminates 14a, overlapping the back surface of the support 61 of another laminate 14a onto the surface of the multilayer film 62 of one laminate 14a, and stacking a predetermined number of laminates 14a. Alternatively, after forming one laminate 14a, a new support 61 may be laminated onto the surface of the multilayer film 62 of that laminate 14a, and a first layer 71 and a second layer 72 may be alternately deposited on the surface of the new support 61 using a vapor deposition apparatus, thereby sequentially forming new laminates 14a on the surface of one laminate 14a.

[0060] As shown in Figure 7, the heating element 19 is configured such that, for example, the support 61 of the laminate 14a at one end is positioned on the first chamber 21 side (high pressure side), and the multilayer film 62 of the laminate 14a at the other end is positioned on the second chamber 22 side (low pressure side). Due to the hydrogen pressure difference between the first chamber 21 and the second chamber 22, the hydrogen introduced into the first chamber 21 permeates through the inside of the heating element 19 in the order of support 61, multilayer film 62, support 61, multilayer film 62... and moves to the second chamber 22. The heating element 19 generates excess heat as hydrogen permeates through each multilayer film 62, that is, through the absorption of hydrogen into each multilayer film 62 and the release of hydrogen from each multilayer film 62. Alternatively, the heating element 19 may have the support 61 positioned on the second chamber 22 side (low pressure side) and the multilayer film 62 positioned on the first chamber 21 side (high pressure side).

[0061] [Second variation] As shown in Figure 8, the hydrogen heating device 11 for the blast furnace may also use a heating element 74 in which a multilayer film 62 is provided on the back surface of the support 61 of the laminated body 14a located at one end, and the multilayer film 62 is provided on both sides of the support 61. The heating element 74 permeates through the multilayer film 62, support 61, multilayer film 62, support 61, multilayer film 62... in that order, and excess heat is generated by the absorption and release of hydrogen in each multilayer film 62. By using the heating element 74, the output of excess heat can be increased.

[0062] [Third variation] The blast furnace hydrogen heating device 11 may be equipped with a heating element 75 as shown in Figure 9 instead of the heating element 14. The heating element 75 shown in Figure 9 has a laminated multilayer film 62 that further includes a third layer 77 in addition to the first layer 71 and the second layer 72. The third layer 77 is formed of a hydrogen storage metal, hydrogen storage alloy, or ceramic different from the first layer 71 and the second layer 72. The thickness of the third layer 77 is preferably less than 1000 nm. In Figure 9, the first layer 71, the second layer 72, and the third layer 77 are laminated on the surface of the support 61 in the order of first layer 71, second layer 72, first layer 71, and third layer 77. Alternatively, the first layer 71, the second layer 72, and the third layer 77 may be laminated on the surface of the support 61 in the order of first layer 71, third layer 77, first layer 71, and second layer 72. In other words, the multilayer film 62 has a laminated structure in which the first layer 71 is provided between the second layer 72 and the third layer 77. The multilayer film 62 only needs to have one or more third layers 77. The heterogeneous material interface 78 formed between the first layer 71 and the third layer 77 allows hydrogen atoms to pass through, similar to the heterogeneous material interface 73.

[0063] The third layer 77 is formed from, for example, Ni, Pd, Cu, Cr, Fe, Mg, Co, alloys thereof, SiC, CaO, Y2O3, TiC, LaB6, SrO, or BaO. The alloy forming the third layer 77 is preferably an alloy consisting of two or more of Ni, Pd, Cu, Cr, Fe, Mg, and Co. As the alloy forming the third layer 77, an alloy in which additive elements are added to Ni, Pd, Cu, Cr, Fe, Mg, or Co may also be used.

[0064] In particular, the third layer 77 is preferably formed from one of CaO, Y2O3, TiC, LaB6, SrO, or BaO. A heating element 75 having a third layer 77 formed from one of CaO, Y2O3, TiC, LaB6, SrO, or BaO increases the amount of hydrogen absorbed, increases the amount of hydrogen that permeates through the heterogeneous material interface 73 and the heterogeneous material interface 78, and enables higher output of excess heat. The third layer 77 formed from one of CaO, Y2O3, TiC, LaB6, SrO, or BaO is preferably 10 nm or less in thickness. This allows hydrogen atoms to easily permeate the multilayer film 62. The third layer 77 formed from one of CaO, Y2O3, TiC, LaB6, SrO, or BaO may not be formed as a complete film but as an island. Furthermore, the first layer 71 and the third layer 77 are preferably deposited continuously under vacuum conditions. As a result, no native oxide film is formed between the first layer 71 and the third layer 77, and only a heterogeneous material interface 78 is formed.

[0065] The combination of the first layer 71, the second layer 72, and the third layer 77, when the types of elements are represented as "first layer 71 - third layer 77 - second layer 72", is Pd-CaO-Ni, Pd-Y2O3-Ni, Pd-TiC-Ni, Pd-LaB6-Ni, Ni-CaO-Cu, Ni-Y2O3-Cu, Ni-TiC-Cu, Ni-LaB6-Cu, Ni-Co-Cu, Ni-CaO-Cr, Ni-Y2O3-Cr, Ni-TiC-Cr, Ni-LaB6- Cr, Ni-CaO-Fe, Ni-Y2O3-Fe, Ni-TiC-Fe, Ni-LaB6-Fe, Ni-Cr-Fe, Ni-CaO-Mg, Ni-Y2O3-Mg, Ni-TiC-Mg, Ni-LaB6-Mg, N Preferred are i-CaO-Co, Ni-Y2O3-Co, Ni-TiC-Co, Ni-LaB6-Co, Ni-CaO-SiC, Ni-Y2O3-SiC, Ni-TiC-SiC, and Ni-LaB6-SiC.

[0066] [Fourth variation] The blast furnace hydrogen heating device 11 may also include a heating element 80 as shown in Figure 10 instead of the heating element 14. The heating element 80 shown in Figure 10 has a multilayer film 62 of a laminate that further includes a fourth layer 82 in addition to the first layer 71, second layer 72, and third layer 77. The fourth layer 82 is formed of a hydrogen storage metal, hydrogen storage alloy, or ceramic different from the first layer 71, second layer 72, and third layer 77. The thickness of the fourth layer 82 is preferably less than 1000 nm. In Figure 10, the first layer 71, second layer 72, third layer 77, and fourth layer 82 are laminated on the surface of the support 61 in the order of first layer 71, second layer 72, first layer 71, third layer 77, first layer 71, and fourth layer 82. The first layer 71, second layer 72, third layer 77, and fourth layer 82 may be stacked on the surface of the support 61 in the order of first layer 71, fourth layer 82, first layer 71, third layer 77, first layer 71, and second layer 72. That is, the multilayer film 62 has a stacked structure in which the second layer 72, third layer 77, and fourth layer 82 are stacked in any order, and the first layer 71 is provided between each of the second layer 72, third layer 77, and fourth layer 82. The multilayer film 62 only needs to have one or more fourth layers 82. The heterogeneous material interface 83 formed between the first layer 71 and the fourth layer 82 allows hydrogen atoms to pass through, similar to the heterogeneous material interface 73 and the heterogeneous material interface 78.

[0067] The fourth layer 82 is formed from, for example, Ni, Pd, Cu, Cr, Fe, Mg, Co, alloys thereof, SiC, CaO, Y2O3, TiC, LaB6, SrO, or BaO. The alloy forming the fourth layer 82 is preferably an alloy consisting of two or more of Ni, Pd, Cu, Cr, Fe, Mg, and Co. As the alloy forming the fourth layer 82, an alloy in which additive elements are added to Ni, Pd, Cu, Cr, Fe, Mg, or Co may also be used.

[0068] In particular, the fourth layer 82 is preferably formed from one of CaO, Y2O3, TiC, LaB6, SrO, or BaO. A heating element 80 having a fourth layer 82 formed from one of CaO, Y2O3, TiC, LaB6, SrO, or BaO increases the amount of hydrogen absorbed, increases the amount of hydrogen permeating through the heterogeneous material interface 73, the heterogeneous material interface 78, and the heterogeneous material interface 83, and can achieve higher output of excess heat. The fourth layer 82, formed from one of CaO, Y2O3, TiC, LaB6, SrO, or BaO, is preferably 10 nm or less in thickness. This allows hydrogen atoms to easily permeate the multilayer film 62. The fourth layer 82, formed from one of CaO, Y2O3, TiC, LaB6, SrO, or BaO, may not be formed as a complete film but as an island. Furthermore, the first layer 71 and the fourth layer 82 are preferably deposited continuously under vacuum conditions. As a result, no native oxide film is formed between the first layer 71 and the fourth layer 82, and only a heterogeneous material interface 83 is formed.

[0069] The combination of the first layer 71, the second layer 72, the third layer 77, and the fourth layer 82 is preferably Ni-CaO-Cr-Fe, Ni-Y2O3-Cr-Fe, Ni-TiC-Cr-Fe, and Ni-LaB6-Cr-Fe, when the types of elements are expressed as "first layer 71 - fourth layer 82 - third layer 77 - second layer 72".

[0070] Furthermore, the heating element may be a mixture of two or more of the following: the laminated heating element 14a shown in Figure 3, the laminated heating element 75 shown in Figure 9, and the laminated heating element 80 shown in Figure 10, with multiple types of laminates stacked alternately or in any order. The configuration of the multilayer film 62, for example, the ratio of the thicknesses of each layer, the number of layers in each layer, and the material may be appropriately changed depending on the temperature at which it is used. Below, we will explain the relationship between the ratio of the thicknesses of each layer in the multilayer film and excess heat, the relationship between the number of layers in the multilayer film and excess heat, and the relationship between the material of the multilayer film and excess heat, and then an example of the configuration of the multilayer film 62 according to temperature will be described.

[0071] The relationship between the ratio of the thicknesses of each layer of a multilayer film and excess heat, the relationship between the number of layers of a multilayer film and excess heat, and the relationship between the material of the multilayer film and excess heat were investigated by preparing an experimental blast furnace hydrogen heating apparatus (not shown) and conducting experiments using this apparatus to determine whether a heating element consisting of a single layer generates excess heat. The experimental blast furnace hydrogen heating apparatus comprises a sealed container, two heating elements placed inside the sealed container, and a heater to heat each heating element. The heating elements are formed in a plate shape. The heater is a plate-shaped ceramic heater with a built-in thermocouple. The heater is located between the two heating elements. The sealed container is connected to a hydrogen-based gas supply path and an exhaust path. The hydrogen-based gas supply path connects a gas cylinder storing hydrogen-based gas to the sealed container. The hydrogen-based gas supply path is equipped with a control valve for adjusting the amount of hydrogen-based gas supplied from the gas cylinder to the sealed container. The exhaust path connects the dry pump, which is used to evacuate the inside of the sealed container, to the sealed container itself. The exhaust path is equipped with control valves and other devices to adjust the amount of gas being exhausted.

[0072] An experimental blast furnace hydrogen heating device generates excess heat from a heating element by repeatedly performing alternating hydrogen storage and hydrogen release processes. Specifically, the experimental blast furnace hydrogen heating device stores hydrogen in the heating element during the hydrogen storage process, and then releases the stored hydrogen during the hydrogen release process. In the hydrogen storage process, a hydrogen-based gas is supplied into the sealed container. In the hydrogen release process, the sealed container is evacuated and the heating element is heated.

[0073] This section explains the relationship between the thickness ratio of each layer in a multilayer film and excess heat. First, focusing on a single laminate 14a, we used a heating element 14 having a support 61 made of Ni and a multilayer film 62 formed by a first layer 71 made of Cu and a second layer 72 made of Ni, to investigate the relationship between the thickness ratio of the first layer 71 and the second layer 72 and excess heat. Hereafter, the thickness ratio of each layer in the multilayer film 62 will be denoted as Ni:Cu.

[0074] Eight types of heating elements 14 were fabricated by forming a multilayer film 62 under the same conditions except for Ni:Cu, and these were designated as Experimental Examples 1 to 8. The multilayer film 62 was formed only on the surface of the support 61. The Ni:Cu ratios of each heating element 14 in Experimental Examples 1 to 8 were 7:1, 14:1, 4.33:1, 3:1, 5:1, 8:1, 6:1, and 6.5:1. In each heating element 14 in Experimental Examples 1 to 8, the multilayer film 62 had a repeating stacked structure of a first layer 71 and a second layer 72. Each heating element 14 in Experimental Examples 1 to 8 had a stacking configuration of 5 layers in the multilayer film 62 (hereinafter referred to as the number of multilayer layers). The overall thickness of the multilayer film 62 was approximately the same for each heating element 14 in Experimental Examples 1 to 8.

[0075] The heating elements 14 from Experimental Examples 1-8 were placed inside a sealed container of an experimental blast furnace hydrogen heating apparatus, and hydrogen storage and hydrogen release processes were repeatedly performed alternately. Light hydrogen gas (Numata Oxygen Co., Ltd., Grade 2, purity 99.999 vol% or higher) was used as the hydrogen gas. In the hydrogen storage process, the hydrogen gas was supplied to the inside of the sealed container at approximately 50 Pa. The time for hydrogen storage in the heating element 14 was approximately 64 hours. Prior to the hydrogen storage process, the inside of the sealed container was baked at over 200°C for approximately 36 hours using a heater to remove any water or other contaminants adhering to the surface of the heating element 14.

[0076] In the hydrogen release process, the heater input power was set to 9W, 18W, and 27W, with the hydrogen storage process in between. The temperature of the heating element 14 during each hydrogen release process was measured using a thermocouple built into the heater. The results are shown in Figure 11. Figure 11 is a graph fitted with the measured data using a predetermined method. In Figure 11, the heater temperature is shown on the horizontal axis, and the power of excess heat is shown on the vertical axis. The heater temperature is the temperature of the heating element 14 at the predetermined input power. In Figure 11, Experiment Example 1 is denoted as "Ni:Cu = 7:1", Experiment Example 2 as "Ni:Cu = 14:1", Experiment Example 3 as "Ni:Cu = 4.33:1", Experiment Example 4 as "Ni:Cu = 3:1", Experiment Example 5 as "Ni:Cu = 5:1", Experiment Example 6 as "Ni:Cu = 8:1", Experiment Example 7 as "Ni:Cu = 6:1", and Experiment Example 8 as "Ni:Cu = 6.5:1".

[0077] Figure 11 confirms that excess heat is generated in all of the heating elements 14 in experimental examples 1 to 8. Therefore, it was confirmed that the hydrogen-based gas can be heated when it permeates through a heating element 14 consisting of a single laminate 14a. Furthermore, if the heating element 14 is made up of multiple such laminates 14a stacked together, the distance the gas permeates through the laminates 14a that generate excess heat is extended, thus increasing the heating time for the hydrogen-based gas and raising its temperature. Therefore, it was found that the temperature of the hydrogen-based gas after it has passed through the heating element 14 can be adjusted by changing the number of layers of laminates 14a stacked in the heating element 14.

[0078] When comparing the heating elements 14 of Experimental Examples 1-8 at heater temperatures above 700°C, it can be seen that Experimental Example 1 generates the largest amount of excess heat. The heating element of Experimental Example 3 generates excess heat over a wide range of heater temperatures, from 300°C to 1000°C, compared to the heating elements 14 of Experimental Examples 1, 2, and 4-8. The heating elements 14 of Experimental Examples 1, 3-8, where the Ni:Cu ratio of the multilayer film 62 is 3:1 to 8:1, show an increase in excess heat as the heater temperature increases. The heating element 14 of Experimental Example 2, where the Ni:Cu ratio of the multilayer film 62 is 14:1, shows a decrease in excess heat at heater temperatures above 800°C. Thus, the fact that excess heat does not simply increase with the ratio of Ni to Cu is thought to be due to the quantum effect of hydrogen in the multilayer film 62.

[0079] Next, we will explain the relationship between the number of layers of a multilayer film and excess heat. Using a heating element 14 consisting of a single laminate 14a made up of a support 61 made of Ni and a multilayer film 62 formed from a first layer 71 made of Cu and a second layer 72 made of Ni, we investigated the relationship between the number of layers of the multilayer film 62 and excess heat.

[0080] Eight types of heating elements 14 (each heating element 14 having one laminate 14a) were fabricated under the same conditions as the heating element 14 in Experimental Example 1, except for the number of layers of the multilayer film 62, and these were designated as Experimental Examples 9 to 16. The number of layers of the multilayer film 62 in each heating element 14 in Experimental Examples 1, 9 to 16 were 5, 3, 7, 6, 8, 9, 12, 4, and 2, respectively.

[0081] Each heating element 14 from Experimental Examples 1, 9-16 was installed inside a sealed container of an experimental blast furnace hydrogen heating apparatus. The experimental blast furnace hydrogen heating apparatus is the same apparatus used to investigate the "relationship between the ratio of thicknesses of each layer of a multilayer film and excess heat" described above. In the experimental blast furnace hydrogen heating apparatus, the temperature of the heating element 14 during the hydrogen release process was measured using the same method as described above for the "relationship between the ratio of thicknesses of each layer of a multilayer film and excess heat". The results are shown in Figure 12. Figure 12 is a graph in which the measured data was fitted using a predetermined method. In Figure 12, the heater temperature is shown on the horizontal axis and the power of excess heat is shown on the vertical axis. In Figure 12, based on the thickness of each layer, Experimental Example 1 is shown as "Ni 0.875 Cu 0.125 5 layers", Experimental example 9 is "Ni 0.875 Cu 0.125 "3 layers", Experimental example 10 is "Ni 0.875 Cu 0.125 7 layers", Experimental example 11 is "Ni 0.875 Cu 0.125 6 layers", Experimental example 12 is "Ni 0.875 Cu 0.125 8 layers", Experimental example 13 is "Ni 0.875 Cu 0.125 9 layers", Experimental example 14 is "Ni 0.875 Cu 0.125 12 layers", Experimental example 15 is "Ni 0.875 Cu 0.125 4 layers", Experimental example 16 is "Ni 0.875 Cu 0.125 It was labeled as "2 layers".

[0082] Figure 12 confirms that all heating elements 14 in experimental examples 1, 9 to 16 generate excess heat. When comparing the heating elements 14 in experimental examples 1, 9 to 16 at heater temperatures of 840°C or higher, it can be seen that experimental example 11, with 6 layers of multilayer film 62, generates the largest amount of excess heat, while experimental example 12, with 8 layers of multilayer film 62, generates the smallest amount. Thus, the excess heat does not simply increase with the number of layers of multilayer film 62, which is thought to be because the wavelength of the wave behavior of hydrogen in the multilayer film 62 is on the order of nanometers and interferes with the multilayer film 62.

[0083] Next, we will explain the relationship between the material of the multilayer film and excess heat. Using a heating element 75 consisting of a single laminate having a multilayer film 62 formed by a first layer 71 made of Ni, a second layer 72 made of Cu, and a third layer 77 made of a hydrogen-absorbing metal, hydrogen-absorbing alloy, or ceramic different from the first layer 71 and the second layer 72, we investigated the relationship between the type of material forming the third layer 77 and excess heat.

[0084] Nine types of heating elements 75 were fabricated by forming a multilayer film 62 under the same conditions except for the type of material forming the third layer 77, and these were designated as Experimental Examples 17 to 25. In each heating element 75 of Experimental Examples 17 to 25, the type of material forming the third layer 77 was CaO, SiC, Y2O3, TiC, Co, LaB6, ZrC, TiB2, and CaOZrO.

[0085] Each heating element 75 from Experimental Examples 17-25 was placed inside a sealed container of an experimental blast furnace hydrogen heating apparatus. The experimental blast furnace hydrogen heating apparatus is the same apparatus used to investigate the "relationship between the ratio of thicknesses of each layer of a multilayer film and excess heat" described above. In the experimental blast furnace hydrogen heating apparatus, the temperature of the heating element 75 during the hydrogen release process was measured using the same method as described above for the "relationship between the ratio of thicknesses of each layer of a multilayer film and excess heat." The results are shown in Figure 13. Figure 13 is a graph in which the measured data was fitted using a predetermined method. In Figure 13, the heater temperature is shown on the horizontal axis and the power of excess heat is shown on the vertical axis. In Figure 13, based on the thickness of each layer, Experimental Example 17 is shown as "Ni 0.793 CaO 0.113 Cu 0.094 Experimental example 18 is "Ni 0.793 SiC 0.113 Cu 0.094 Experimental example 19 is "Ni 0.793 Y2O 30.113 Cu 0.094 Experimental example 20 is "Ni 0.793 TiC 0.113 Cu 0.094 Experimental example 21 is "Ni 0.793 Co 0.113 Cu 0.094 Experimental example 22 is "Ni 0.793 LaB 60.113 Cu 0.094 Experimental example 23 is "Ni0.793 ZrC 0.113 Cu 0.094 Experimental example 24 is "Ni 0.793 TiB 20.113 Cu 0.094 Experimental example 25 is "Ni 0.793 CaOZrO 0.113 Cu 0.094 It was written as "".

[0086] Figure 13 shows that all of the heating elements 75 in experimental examples 17-25 generated excess heat. Therefore, it was confirmed that the hydrogen-based gas can be heated when it permeates through a heating element 75 consisting of a single laminate. Furthermore, if the heating element 75 is made up of multiple such laminates, the distance the gas permeates through the laminate that generates excess heat increases, thus extending the heating time for the hydrogen-based gas and allowing the temperature of the hydrogen-based gas to be raised. Therefore, it was found that the temperature of the hydrogen-based gas after it has passed through the heating element 75 can be adjusted by changing the number of laminates in the heating element 75.

[0087] In particular, in Experimental Example 17, Experimental Example 20, and Experimental Example 22, where the material forming the third layer 77 is CaO, TiC, and LaB6, it can be seen that the excess heat increases almost linearly over a wide range of heater temperatures from 400°C to 1000°C, compared to the other Experimental Examples 18, 19, 21, 23-25. The materials forming the third layer 77 in Experimental Examples 17, 20, and 22 have smaller work functions than the materials in the other Experimental Examples 18, 19, 21, 23-25. From this, it can be seen that a material with a small work function is preferable for forming the third layer 77. These results suggest that the electron density within the multilayer film 62 may contribute to the exothermic reaction.

[0088] An example of the configuration of the multilayer film 62 according to the temperature of the heating element 14 is described below. Considering the relationship between the ratio of the thickness of each layer of the multilayer film and excess heat as described above for the heating element 14, when the temperature of the heating element 14 is low (for example, in the range of 50°C to 500°C), it is preferable that the ratio of the thickness of each layer of the multilayer film 62 is in the range of 2:1 to 5:1. When the temperature of the heating element 14 is medium (for example, in the range of 500°C to 800°C), it is preferable that the ratio of the thickness of each layer of the multilayer film 62 is in the range of 5:1 to 6:1. When the temperature of the heating element 14 is high (for example, in the range of 800°C to 1000°C), it is preferable that the ratio of the thickness of each layer of the multilayer film 62 is in the range of 6:1 to 12:1.

[0089] Considering the "relationship between the number of layers of the multilayer film and excess heat" described above, when the temperature of the heating element 14 is low, medium, or high, it is preferable that the first layer 71 of the multilayer film 62 is in the range of 2 to 18 layers, and the second layer 72 is in the range of 2 to 18 layers.

[0090] Regarding the heating element 75, considering the "relationship between the multilayer film material and excess heat" described above, when the temperature of the heating element 75 is low, it is preferable that the first layer 71 is Ni, the second layer 72 is Cu, and the third layer 77 is Y2O3. When the temperature of the heating element 75 is medium, it is preferable that the first layer 71 is Ni, the second layer 72 is Cu, and the third layer 77 is TiC. When the temperature of the heating element 75 is high, it is preferable that the first layer 71 is Ni, the second layer 72 is Cu, and the third layer 77 is CaO or LaB6.

[0091] [Fifth variation] Figure 14 is a cross-sectional view of a heating element 90 formed in the shape of a bottomed cylindrical body with one end open and the other end closed. The heating element 90 is provided with a plurality of laminates 90a having a support 91 and a multilayer film 92. In this case, the multilayer film 92 is formed along the outer circumferential surface and outer bottom surface of the support 91, which is formed in the shape of a bottomed cylindrical body with one end open and the other end closed, and the multilayer film 92 is also formed in the shape of a bottomed cylindrical body with one end open and the other end closed.

[0092] The heating element 90 has a support 91 of the outer laminate 90a provided along the outer peripheral surface and outer bottom surface of the multilayer film 92 of the inner laminate 90a, and the support 91 and multilayer film 92 are alternately stacked from the inner side to the outer side, in the order of support 91, multilayer film 92, support 91 and multilayer film 92. In this way, the heating element 90 has multiple bottomed cylindrical laminates 90a stacked on top of each other, and the number of stacks of the laminates 90a is set so that the hydrogen-based gas that permeates through the heating element 90 is heated to a predetermined temperature.

[0093] Each support 91 is formed from at least one of a porous material, a hydrogen permeable membrane, and a proton conductor. Each multilayer film 92 is formed from a hydrogen-absorbing metal or hydrogen-absorbing alloy and has a thickness of less than 1000 nm, and has a second layer (not shown) which is formed from a different hydrogen-absorbing metal, hydrogen-absorbing alloy, or ceramic and has a thickness of less than 1000 nm. In Figure 14, the heating element 90 is formed in the shape of a bottomed cylindrical shape, but it may also be formed in the shape of a bottomed rectangular tube.

[0094] Next, an example of a method for manufacturing the heating element 90 will be described. The heating element 90 is manufactured by preparing a support 91 formed in the shape of a bottomed cylindrical body and forming a multilayer film 92 on the support 91 using a wet film deposition method. In this example, the multilayer film 92 is formed on the outer surface of the support 91. This forms the innermost bottomed cylindrical laminate 90a. Next, another support 91 formed in the shape of a sheet is prepared and a multilayer film 92 is formed on the outer surface of the sheet support 91 using a wet film deposition method to form a new bottomed cylindrical sheet laminate 90a. Then, by repeatedly stacking the other sheet laminates 90a on the outer surface of the innermost laminate 90a, a heating element 90 can be manufactured in which multiple laminates 90a are stacked. Alternatively, the support 91 and the multilayer film 92 may be formed sequentially, for example, by forming the multilayer film 92 on the outer surface of the innermost bottomed cylindrical support 91, then forming a sheet support 91 on the outer surface and bottom of the multilayer film 92, and then forming the multilayer film 92 again on the outer surface and bottom of the support 91.

[0095] Wet film deposition methods include spin coating, spray coating, and dipping. The multilayer film 92 may also be formed using ALD (Atomic Layer Deposition), or the multilayer film 92 may be formed on the support 91 while rotating it using a sputtering apparatus equipped with a rotating mechanism for rotating the support 91. The multilayer film 92 may also be provided on the innermost surface of the support 91, so that the innermost support 91 has multilayer films 92 on both sides.

[0096] As shown in Figure 15, the blast furnace equipment 95 comprises a blast furnace hydrogen heating device 96 and a blast furnace 12. The blast furnace hydrogen heating device 96 differs from the blast furnace hydrogen heating device 11 of the above embodiment in that it includes a heating element 90 instead of a heating element 14. The heating element 90 is attached to the sealed container 15 using a mounting pipe 97. Although not shown in Figure 15, the blast furnace hydrogen heating device 96 includes a temperature sensor for detecting the temperature of the heating element 90, a power supply for inputting power to the heater 16b, and a control unit as an output control unit that controls the output of the heater 16b based on the temperature detected by the temperature sensor. The temperature sensor is provided, for example, on the outer surface of the heating element 90.

[0097] The connecting pipe 97 is made of, for example, stainless steel. The connecting pipe 97 penetrates the sealed container 15, with one end positioned on the outside of the sealed container 15 and the other end positioned inside the sealed container 15. One end of the connecting pipe 97 is connected to the introduction line 29 of the hydrogen distribution line 17. A heating element 90 is provided at the other end of the connecting pipe 97.

[0098] In the fifth modified example, the first chamber 21 is formed by the inner surface of the heating element 90. The second chamber 22 is formed by the inner surface of the sealed container 15 and the outer surface of the heating element 90. Therefore, the support 91 of the heating element 90 is positioned on the first chamber 21 side (high pressure side), and the multilayer film 92 is positioned on the second chamber 22 side (low pressure side) (see Figure 14). Due to the pressure difference between the first chamber 21 and the second chamber 22, hydrogen introduced into the first chamber 21 permeates through the inside of the heating element 90 in the order of support 91, multilayer film 92, support 91, multilayer film 92, ... and moves to the second chamber 22. That is, hydrogen permeates through a predetermined number of stacked layers 90a from the inner surface to the outer surface of the heating element 90. As a result, each stacked layer 90a of the heating element 90 generates excess heat when hydrogen is released from the multilayer film 92. Therefore, the hydrogen heating device 96 for blast furnaces has the same effects and advantages as the hydrogen heating device 11 for blast furnaces in the above embodiment.

[0099] The blast furnace hydrogen heating device 96 may also be equipped with a heating element 98 as shown in Figure 16 instead of the heating element 90. The heating element 98 differs from the heating element 90 in that its innermost laminated body 90b has a columnar support 91a. The support 91a, like the support 61, is formed from at least one of a porous material, a hydrogen permeable membrane, and a proton conductor. The support 91a improves the mechanical strength of the heating element 98 while allowing the passage of hydrogen-based gas. Although the support 91a is formed in a cylindrical shape in Figure 16, it may also be formed in a prismatic shape. Furthermore, although the fifth modified example above shows a configuration in which multiple laminated bodies 90a are stacked, a configuration with only one laminated body 90a is also possible.

[0100] [Sixth variation] As shown in Figure 17, the blast furnace equipment 115 comprises a blast furnace hydrogen heating device 121 and a blast furnace 12. The blast furnace hydrogen heating device 121 differs from the blast furnace hydrogen heating device 11 of the above embodiment in that it has a sealed container 123 instead of a sealed container 15. The sealed container 123 is a hollow container that houses a heating element 14 inside. The sealed container 123 is covered with an insulating material 51. The sealed container 123 is provided with a mounting pipe 125 for attaching the heating element 14.

[0101] The connecting pipe 125 is made of, for example, stainless steel. The connecting pipe 125 penetrates the sealed container 123, with one end located outside the sealed container 123 and the other end located inside the sealed container 123. In this example, one end of the connecting pipe 125 is located inside the insulation material 51. One end of the connecting pipe 125 is connected to the introduction line 29 of the hydrogen distribution line 17. A heating element 14 is provided at the other end of the connecting pipe 125. A heater 16b of the temperature control section (not shown) is wrapped around the outer circumference of the connecting pipe 125.

[0102] The sealed container 123 has a first chamber 126 and a second chamber 127, separated by a connecting pipe 125 and a heating element 14. The first chamber 126 is formed by the surface of the heating element 14 and the inner surface of the connecting pipe 125. The first chamber 126 has an inlet 23 that connects to the introduction line 29. The second chamber 127 is formed by the inner surface of the sealed container 123, the back surface of the heating element 14 and the outer surface of the connecting pipe 125. The second chamber 127 has an outlet 24 that connects to the discharge line 30. In Figure 17, the outlet 24 is located approximately in the center of the longitudinal direction of the sealed container 123. The first chamber 126 is pressurized when a hydrogen-based gas is introduced. The second chamber 127 is depressurized when the hydrogen-based gas is exhausted. As a result, the hydrogen pressure in the first chamber 126 is higher than the hydrogen pressure in the second chamber 127. The hydrogen pressures in the first chamber 126 and the second chamber 127 are different. As a result, a pressure difference is created inside the sealed container 123 on both sides of the heating element 14.

[0103] The heated hydrogen-based gas flowing through the outlet line 30 is sent to the inside of the blast furnace 12 via the outlet line 30 from the tuyeres of the blast furnace 12, as in the embodiment described above, and is used as a reducing gas in the blast furnace 12.

[0104] As described above, in the blast furnace hydrogen heating device 121, hydrogen-based gas flows from the first chamber 126 inside the mounting pipe 125 to the second chamber 127 through the heating element 14 provided at the tip of the mounting pipe 125, within the sealed container 123. The heat generated by each layer 14a of the heating element 14 heats the hydrogen-based gas. In this case, the blast furnace hydrogen heating device 121 can also raise the temperature of the hydrogen-based gas to a predetermined temperature by setting the number of layers 14a of the heating element 14 to a predetermined number, thus having the same effects as the blast furnace hydrogen heating device 11 of the above embodiment.

[0105] [7th variation] As shown in Figure 18, the blast furnace equipment 145 comprises a blast furnace hydrogen heating device 146 and a blast furnace 12. The blast furnace hydrogen heating device 146 has a heater 137 in the introduction line 29 and a nozzle section 148 arranged inside a sealed container 15. The blast furnace hydrogen heating device 146 differs from the blast furnace hydrogen heating device 11 of the above embodiment in the arrangement of the heater 137 in the temperature control section (not shown), and in the provision of the nozzle section 148 and the non-permeable gas recovery line 149, which will be described later. The temperature control section (not shown) is formed by a temperature sensor 16a, a heater 137, and a control unit 18 as an output control unit.

[0106] The heater 137 is located in the introduction line 29 and heats the heating element 14 by heating the hydrogen-based gas flowing through the introduction line 29. The heater 137 is electrically connected to the power supply 26 and generates heat when power is input from the power supply 26. The power input to the power supply 26 is controlled by the control unit 18. The control unit 18 maintains the heating element 14 at an appropriate temperature for heating by adjusting the power input to the heater 137 based on the temperature detected by the temperature sensor 16a.

[0107] The blast furnace hydrogen heating device 146 has a heater 137 in the introduction line 29, which allows heated hydrogen-based gas to be sent into the sealed container 15. This heated hydrogen-based gas heats the heating element 14, maintaining the heating element 14 at a temperature suitable for heat generation. Even with this configuration, it has the same effects and advantages as the blast furnace hydrogen heating device 11 of the above embodiment.

[0108] The nozzle section 148 is provided between the inlet 23 and the heating element 14. The nozzle section 148 is connected to the introduction line 29 via the inlet 23. The nozzle section 148 injects hydrogen-based gas, which has flowed through the introduction line 29 and had impurities removed by the filter 31, from an injection port provided at the nozzle tip. The distance between the nozzle tip and the surface of the heating element 14 is, for example, 1 to 2 cm. The orientation of the nozzle tip is perpendicular to the surface of the heating element 14. As a result, the nozzle section 148 injects hydrogen-based gas over the entire surface of one side of the heating element 14. Preferably, the distance between the nozzle tip and the surface of the heating element 14, or the orientation of the nozzle tip, is such that the hydrogen-based gas emitted from the nozzle tip is blown over the entire surface of the heating element 14.

[0109] The impermeable gas recovery line 149 is connected to an impermeable gas recovery port 151 located in the first chamber 21, and recovers impermeable gas from the hydrogen-based gas introduced into the first chamber 21 that did not permeate the heating element 14. The impermeable gas recovery line 149 is connected to the hydrogen tank 28, and the recovered impermeable gas is returned to the hydrogen tank 28. The impermeable gas recovery port 151 is located next to the inlet 23.

[0110] In the above configuration, the hydrogen-based gas introduced into the first chamber 21 is heated by the heat of each layer 14a as it sequentially permeates through each layer 14a of the heating element 14. The hydrogen-based gas heated by permeating through the heating element 14 is discharged to the discharge line 30. The hydrogen-based gas discharged to the discharge line 30 is supplied to the blast furnace 12 via the pressure regulating valve 32.

[0111] Meanwhile, the remaining hydrogen-based gas introduced into the first chamber 21 that did not permeate the heating element 14 is recovered as impermeable gas in the impermeable gas recovery line 149. The impermeable gas flows through the impermeable gas recovery line 149 back to the hydrogen tank 28, then flows again through the introduction line 29 and is introduced into the first chamber 21 as hydrogen-based gas. In other words, the impermeable gas recovery line 149 connects the first chamber 21 and the introduction line 29, recovers the impermeable gas that did not permeate the heating element 14 from the hydrogen-based gas introduced into the first chamber 21 from the introduction line 29, and returns it back to the introduction line 29.

[0112] The impermeable gas recovery line 149 includes an impermeable gas flow rate control unit 152 and a circulation pump 153. The impermeable gas flow rate control unit 152 has, for example, a variable leak valve as a control valve. The impermeable gas flow rate control unit 152 controls the flow rate of the impermeable gas based on the temperature detected by the temperature sensor 16a. For example, if the temperature of the heating element 14 detected by the temperature sensor 16a exceeds the upper limit temperature of the temperature range appropriate for the heating element 14 to generate heat, the impermeable gas flow rate control unit 152 increases the circulation flow rate of the impermeable gas. If the temperature of the heating element 14 detected by the temperature sensor 16a falls below the lower limit temperature of the temperature range appropriate for the heating element 14 to generate heat, the impermeable gas flow rate control unit 152 decreases the flow rate of the impermeable gas. In this way, the impermeable gas flow rate control unit 152 maintains the heating element 14 at a temperature appropriate for generating heat by increasing or decreasing the circulation flow rate of the impermeable gas.

[0113] The circulation pump 153 recovers the impermeable gas from the first chamber 21 through the impermeable gas recovery port 151 and sends it to the hydrogen tank 28. For example, a metal bellows pump is used as the circulation pump 153. The circulation pump 153 is electrically connected to the control unit 18.

[0114] In the blast furnace hydrogen heating device 146, the nozzle section 148 allows the hydrogen-based gas, after impurities have been removed, to be directly blown onto the surface of the heating element 14. As a result, in the blast furnace hydrogen heating device 146, impurities on and around the surface of the heating element 14 are blown away, and the surface of the heating element 14 is placed in an atmosphere formed by fresh hydrogen-based gas from which impurities have been removed by the filter 31, thereby enabling high output of excess heat.

[0115] [8th variation] As shown in Figure 19, the blast furnace equipment 155 comprises a blast furnace hydrogen heating device 156 and a blast furnace 12. The blast furnace hydrogen heating device 156 is equipped with a heating element 90 instead of a heating element 14, and has a nozzle section 158 located inside a sealed container 15. In this example, an inlet 23 and a non-permeable gas recovery port 151 are provided side by side on the mounting pipe 97.

[0116] The nozzle section 158 is located between the inlet 23 and the heating element 90, with one end connected to the inlet 23 and the other end extending to the other end of the heating element 90. The nozzle section 158 is connected to the inlet line 29 via the inlet 23.

[0117] As shown in Figure 20, the cylindrical nozzle portion 158 has a plurality of injection ports 159 formed on its circumferential surface along the axial direction of the heating element 90. In addition, the nozzle portion 158 according to this embodiment also has injection ports 159 formed on its bottom surface. The nozzle portion 158 injects hydrogen-based gas from the plurality of injection ports 159 onto the entire inner surface (inner circumferential surface and inner bottom surface) of the heating element 90. It is preferable that the plurality of injection ports 159 are arranged at equal intervals. By arranging the plurality of injection ports 159 at equal intervals, the hydrogen-based gas is uniformly injected onto the entire inner surface of the heating element 90. The number and diameter of the injection ports 159 may be changed as appropriate. Furthermore, although the eighth modified example above shows a configuration in which multiple laminates 90a are stacked, a configuration with only one laminate 90a is also possible.

[0118] Furthermore, the heating element 90 has a configuration in which an impermeable gas recovery line 149 is connected to an impermeable gas recovery port 151 provided in the first chamber 21, and impermeable gas from the hydrogen-based gas introduced into the first chamber 21 that did not permeate the heating element 14 can be recovered from the impermeable gas recovery line 149.

[0119] Furthermore, the hydrogen heating device 156 for blast furnaces injects hydrogen-based gas from the nozzle section 158, which blows away impurities from the inner surface and surrounding area of ​​the heating element 90. At the same time, the inside of the heating element 90 is filled with an atmosphere formed by fresh hydrogen-based gas from which impurities have been removed by the filter 31, thereby enabling increased output of excess heat.

[0120] [9th variation] Figure 21 is a cross-sectional view of a cylindrical heating element 160 with open ends. The heating element 160 has a plurality of laminates 160a, each having a support 161 and a multilayer film 162. In this case, each laminate 160a has a configuration in which a cylindrical multilayer film 162 is formed on the outer surface of a cylindrical support 161. In the heating element 160, the support 161 of one laminate 160a is provided on the outer surface of the multilayer film 162 of another laminate 160a, and the support 161 and multilayer film 162 are arranged sequentially and alternately from the inside out, so as follows: support 161, multilayer film 162, support 161, multilayer film 162. In this way, the heating element 160 has a plurality of cylindrical laminates 160a stacked on top of each other, and the number of stacks of the laminates 160a is set so that the hydrogen-based gas that permeates through the heating element 160 is heated to a predetermined temperature.

[0121] The support 161 is formed of at least one of a porous material, a hydrogen permeable membrane, and a proton conductor. The multilayer film 162 has a first layer (not shown) formed of a hydrogen-absorbing metal or hydrogen-absorbing alloy with a thickness of less than 1000 nm, and a second layer (not shown) formed of a hydrogen-absorbing metal, hydrogen-absorbing alloy, or ceramic different from the first layer with a thickness of less than 1000 nm. The method for manufacturing the heating element 160 is the same as the method for manufacturing the heating element 90, except for preparing a cylindrical support 161 with both ends open, so the explanation is omitted. In Figure 21, the heating element 160 is formed in a cylindrical shape with both ends open, but it may also be formed in a rectangular tube shape with both ends open. In addition, although the ninth modified example above shows a configuration in which multiple laminates 160a are stacked, it may also be a configuration having only one laminate 160a.

[0122] As shown in Figure 22, the blast furnace equipment 165 comprises a blast furnace hydrogen heating device 166 and a blast furnace 12. The blast furnace hydrogen heating device 166 differs from the blast furnace hydrogen heating device 156 of the eighth modified example above in that it is equipped with a heating element 160 instead of a heating element 90.

[0123] The heating element 160 is provided with connecting pipes 97 at both ends. The connecting pipe 97 at one end of the heating element 160 is connected to the introduction line 29. The connecting pipe 97 at the other end of the heating element 160 is connected to the non-permeable gas recovery line 149. In other words, one end of the heating element 160 is connected to the introduction line 29, and the other end is connected to the non-permeable gas recovery line 149. Therefore, the blast furnace hydrogen heating device 166, like the blast furnace hydrogen heating device 156 of the eighth modified example described above, can recover non-permeable gas from the non-permeable gas recovery line 149 from the hydrogen-based gas introduced into the first chamber 21 that did not permeate the heating element 160.

[0124] [10th variation] In the above embodiments and each of the above modifications, a hydrogen pressure difference is generated between the first and second chambers by introducing a hydrogen-based gas from the introduction line to the first chamber and releasing the hydrogen-based gas from the second chamber to the discharge line via a hydrogen flow line. However, in the 10th modification, instead of using a hydrogen flow line, a hydrogen storage metal or hydrogen storage alloy is used to generate a hydrogen pressure difference between the first and second chambers by utilizing the absorption and release of hydrogen. The 10th modification hydrogen heating apparatus for blast furnaces will now be described, focusing on its differences from the above embodiments and each of the above modifications.

[0125] As shown in Figure 23, the blast furnace hydrogen heating device 171 comprises a heating element 14, a sealed container 173, a first hydrogen absorption and release section 174, a second hydrogen absorption and release section 175, a first temperature sensor 176, a second temperature sensor 177, a first heater 178, a second heater 179, a first pressure gauge 180, a second pressure gauge 181, and a hydrogen pressure control unit 182. The heating element 14 may be configured as a single laminated body 14a (see Figure 2), or as a configuration in which multiple laminated bodies 14a are stacked in a predetermined number of layers (see Figure 6). The blast furnace hydrogen heating device 171 further includes a control unit as an output control unit (not shown). A temperature control unit (not shown) is formed by the control unit, which acts as an output control unit, the first temperature sensor 176, the second temperature sensor 177, the first heater 178, and the second heater 179. The temperature control unit adjusts the temperature of the heating element 14 and maintains it at a temperature appropriate for heat generation.

[0126] The sealed container 173 has a first chamber 184 and a second chamber 185 separated by a heating element 14. The hydrogen pressures in the first chamber 184 and the second chamber 185 are switched by a hydrogen pressure control unit 182, which will be described later. The first chamber 184 is formed by the surface of the heating element 14 and the inner surface of the sealed container 173. The second chamber 185 is formed by the back surface of the heating element 14 and the inner surface of the sealed container 173. Although not shown in Figure 23, the sealed container 173 is provided with an inlet in either the first chamber 184 or the second chamber 185, and an inlet line for introducing hydrogen-based gas is connected to the inlet. Also, although not shown in Figure 23, the sealed container 173 is provided with an outlet in either the first chamber 184 or the second chamber 185, and an outlet line for discharging the hydrogen-based gas heated by the heating element 14 to the blast furnace is connected to the outlet.

[0127] The first hydrogen storage and release section 174 is located in the first chamber 184. The first hydrogen storage and release section 174 is made of a hydrogen storage metal or a hydrogen storage alloy. The first hydrogen storage and release section 174 stores and releases hydrogen. The hydrogen storage and release of the first hydrogen storage and release section 174 are sequentially switched by the hydrogen pressure control section 182, which will be described later.

[0128] The second hydrogen storage and release section 175 is located in the second chamber 185. The second hydrogen storage and release section 175 is made of a hydrogen storage metal or hydrogen storage alloy. The second hydrogen storage and release section 175 stores and releases hydrogen. The hydrogen storage and release of the second hydrogen storage and release section 175 are sequentially switched by the hydrogen pressure control unit 182, which will be described later.

[0129] The first temperature sensor 176 is provided in the first hydrogen storage and release section 174 and detects the temperature of the first hydrogen storage and release section 174. The second temperature sensor 177 is provided in the second hydrogen storage and release section 175 and detects the temperature of the second hydrogen storage and release section 175.

[0130] The first heater 178 is provided in the first hydrogen storage and release section 174 and heats the first hydrogen storage and release section 174. The first heater 178 is electrically connected to the power supply 187 and generates heat when power is input from the power supply 187. The second heater 179 is provided in the second hydrogen storage and release section 175 and heats the second hydrogen storage and release section 175. The second heater 179 is electrically connected to the power supply 188 and generates heat when power is input from the power supply 188.

[0131] The first pressure gauge 180 is located inside the first chamber 184 and detects the hydrogen pressure in the first chamber 184. The second pressure gauge 181 is located inside the second chamber 185 and detects the hydrogen pressure in the second chamber 185.

[0132] The hydrogen pressure control unit 182 is electrically connected to the first temperature sensor 176, the second temperature sensor 177, the first pressure gauge 180, the second pressure gauge 181, the power supply 187, and the power supply 188.

[0133] The hydrogen pressure control unit 182 controls the temperature of the first hydrogen storage and release unit 174 based on the temperature detected by the first temperature sensor 176. The hydrogen pressure control unit 182 heats the first hydrogen storage and release unit 174 to a predetermined temperature by turning on the power supply 187 and adjusting the input power to the first heater 178. The hydrogen pressure control unit 182 also cools the first hydrogen storage and release unit 174 by turning off the power supply 187. The first hydrogen storage and release unit 174 may also be cooled using a cooling device (not shown).

[0134] The hydrogen pressure control unit 182 controls the temperature of the second hydrogen storage and release unit 175 based on the temperature detected by the second temperature sensor 177. The hydrogen pressure control unit 182 heats the second hydrogen storage and release unit 175 to a predetermined temperature by turning on the power supply 188 and adjusting the input power to the second heater 179. The hydrogen pressure control unit 182 also cools the second hydrogen storage and release unit 175 by turning off the power supply 188. The second hydrogen storage and release unit 175 may also be cooled using a cooling device (not shown).

[0135] The hydrogen pressure control unit 182 has a first mode in which the hydrogen pressure in the first chamber 184 is made higher than the hydrogen pressure in the second chamber 185, and a second mode in which the hydrogen pressure in the second chamber 185 is made higher than the hydrogen pressure in the first chamber 184.

[0136] In the first mode, as shown in Figure 24, the hydrogen pressure control unit 182 heats the first hydrogen storage and release unit 174 with the first heater 178 and cools the second hydrogen storage and release unit 175. The first hydrogen storage and release unit 174 releases hydrogen when heated. The first chamber 184 is pressurized as hydrogen is released from the first hydrogen storage and release unit 174. Meanwhile, the second hydrogen storage and release unit 175 absorbs hydrogen when cooled. The second chamber 185 is depressurized as hydrogen is absorbed into the second hydrogen storage and release unit 175. As a result, the hydrogen pressure in the first chamber 184 is made higher than the hydrogen pressure in the second chamber 185. Due to the hydrogen pressure difference between the first chamber 184 and the second chamber 185, the hydrogen in the first chamber 184 permeates through the heating element 14 and moves to the second chamber 185. The heating element 14 generates excess heat as hydrogen permeates through it.

[0137] In the second mode, as shown in Figure 25, the hydrogen pressure control unit 182 cools the first hydrogen storage and release unit 174 and heats the second hydrogen storage and release unit 175 with the second heater 179. The first hydrogen storage and release unit 174 absorbs hydrogen as it is cooled. The first chamber 184 is depressurized as hydrogen is absorbed into the first hydrogen storage and release unit 174. On the other hand, the second hydrogen storage and release unit 175 releases hydrogen as it is heated. The second chamber 185 is pressurized as hydrogen is released from the second hydrogen storage and release unit 175. As a result, the hydrogen pressure in the second chamber 185 is made higher than the hydrogen pressure in the first chamber 184. Due to the hydrogen pressure difference between the first chamber 184 and the second chamber 185, the hydrogen in the second chamber 185 permeates through the heating element 14 and moves to the first chamber 184. The heating element 14 generates excess heat as hydrogen permeates through it.

[0138] The hydrogen pressure control unit 182 performs switching control to switch between the first mode and the second mode. An example of the switching control is described below. When the pressure detected by the first pressure gauge 180 falls below a predetermined threshold during the first mode, the hydrogen pressure control unit 182 switches from the first mode to the second mode. When the pressure detected by the second pressure gauge 181 falls below a predetermined pressure during the second mode, the hydrogen pressure control unit 182 switches from the second mode to the first mode. By performing switching control between the first mode and the second mode, the hydrogen pressure control unit 182 switches the direction in which hydrogen permeates the heating element 14, which is made up of a predetermined number of stacked layers of laminate 14a, thereby intermittently sustaining the generation of excess heat in the heating element 14.

[0139] Therefore, even in this case, the blast furnace hydrogen heating device 171 can heat the hydrogen-based gas to a predetermined temperature by heating with the heating element 14 by setting the number of stacks of the heating element 14, thus having the same effects as the blast furnace hydrogen heating device 11 of the above embodiment. Furthermore, the blast furnace hydrogen heating device 171 can be miniaturized because it can generate a hydrogen pressure difference between the first chamber and the second chamber without using a hydrogen flow line.

[0140] [11th variation] Although the hydrogen heating apparatus for blast furnaces in the above embodiments and each of the above modifications uses a heating element, multiple heating elements may be used.

[0141] As shown in Figure 26, the blast furnace equipment 190 comprises a blast furnace hydrogen heating device 191 and a blast furnace 12. The blast furnace hydrogen heating device 191 comprises a plurality of heating elements 14, a sealed container 193 housing the plurality of heating elements 14, and an impermeable gas recovery line 149, etc. The plurality of heating elements 14 are each formed in a plate shape. The plurality of heating elements 14 are arranged with gaps between them so that their surfaces face each other. In this example, six heating elements 14 are arranged inside the sealed container 193 (see Figures 26 and 27). A heater 16b of a temperature control unit (not shown) is provided on the outer circumference of the sealed container 193. The heater 16b heats the plurality of heating elements 14 by receiving power from a power source (not shown).

[0142] The sealed container 193 is provided with a plurality of inlets 23, a plurality of outlets 24, and a plurality of impermeable gas recovery ports 151. The inlets 23 are positioned opposite the impermeable gas recovery ports 151. The outlets 24 and impermeable gas recovery ports 151 are arranged alternately in the direction of the arrangement of the plurality of heating elements 14. The plurality of inlets 23 are connected to an introduction line 29 using, for example, a gas introduction branch pipe (not shown). The plurality of outlets 24 are connected to an outlet line 30 using, for example, a gas introduction branch pipe (not shown).

[0143] The sealed container 193 has multiple first chambers 194 and multiple second chambers 195 separated by multiple heating elements 14. The first chambers 194 and second chambers 195 are gaps between heating elements 14 with their faces facing each other, and are arranged alternately in the direction of the arrangement of the multiple heating elements 14. The first chambers 194 have an inlet 23 and an impermeable gas recovery port 151. The second chambers 195 have an outlet 24. The first chambers 194 are pressurized when hydrogen-based gas is introduced from the inlet line 29. The second chambers 195 are depressurized when hydrogen-based gas is discharged to the outlet line 30. As a result, the hydrogen pressure in the first chambers 194 is higher than the hydrogen pressure in the second chambers 195.

[0144] As shown in Figure 27, due to the hydrogen pressure difference between the first chamber 194 and the second chamber 195, a portion of the hydrogen-based gas introduced into the first chamber 194 permeates the heating element 14, which is made up of a predetermined number of stacked layers 14a, moves to the second chamber 195, and is led out to the discharge line 30. On the other hand, the non-permeable gas of the hydrogen-based gas introduced into the first chamber 194 that does not permeate the heating element 14 is recovered in the non-permeable gas recovery line 149. Each heating element 14 generates excess heat as the hydrogen-based gas permeates through it. Therefore, in the blast furnace hydrogen heating device 191, as in the above embodiment, a hydrogen-based gas at a predetermined temperature can be obtained by setting the number of stacked layers 14a to a predetermined number in advance. Furthermore, in this blast furnace hydrogen heating device 191, the output of excess heat can be increased by providing multiple heating elements 14. In addition, although the 11th modified example above shows a configuration in which multiple stacked layers 14a are stacked, a configuration with only one stacked layer 14a is also possible.

[0145] In the 11th modified example described above, the non-permeable gas that did not permeate the heating element 14 was recovered in the non-permeable gas recovery line 149 and returned to the introduction line 29 to circulate the non-permeable gas. However, the present invention is not limited to this, and a hydrogen heating device for a blast furnace may be provided without the non-permeable gas recovery line 149, and without the circulation of non-permeable gas. In this case, the first chamber 194 is configured such that the non-permeable gas recovery port 151 is not provided in a position opposite the introduction port 23, and only the introduction port 23 is provided.

[0146] The hydrogen-based gas introduced into the first chamber 194 then permeates through the heating element 14, moves to the second chamber 195, and is discharged to the discharge line 30. As the hydrogen-based gas permeates through each stack 14a of the heating element 14, excess heat is generated in each stack 14a, and the gas is heated by the excess heat generated in these stacks 14a before moving to the second chamber 195. Therefore, in this blast furnace hydrogen heating apparatus as well, similar to the 11th modified example described above, a hydrogen-based gas at a predetermined temperature can be obtained by setting the number of stacks of the multiple stacks 14a in advance.

[0147] In the 11th modified example described above, the present invention is not limited to the case in which multiple plate-shaped heating elements 14 are provided. For example, the present invention may also be a hydrogen heating device for a blast furnace that provides multiple bottomed cylindrical heating elements 90 as shown in Figures 14 and 20, heating element 98 as shown in Figure 16, or cylindrical heating element 160 as shown in Figure 21. Alternatively, the present invention may be a hydrogen heating device for a blast furnace that provides a mixture of multiple heating elements with different configurations, such as bottomed cylindrical heating elements 90 and cylindrical heating elements 160.

[0148] Furthermore, if multiple heating elements such as heating element 14, heating element 90, heating element 98, and / or heating element 160 are provided inside a single sealed container, the temperature of each heating element may be controlled independently within the sealed container. For example, if multiple heating elements 90 are provided inside a single sealed container, one temperature sensor and heater are provided for each heating element 90. That is, one temperature sensor detects the temperature of one heating element 90. The multiple temperature sensors are electrically connected to the control unit 18 and output a signal to the control unit 18 corresponding to the temperature of each heating element 90 detected. The control unit 18 independently controls the output of each heater based on the temperature detected by each temperature sensor. Therefore, in such a hydrogen heating apparatus for blast furnaces, the temperature of each heating element 90 is controlled independently, and the multiple heating elements 90 are maintained at temperatures appropriate for heating, thereby stabilizing the output of excess heat.

[0149] Furthermore, if multiple heating elements such as heating element 14, heating element 90, heating element 98, and / or heating element 160 are provided, each heating element may be placed in a different sealed container. In addition, a flow control valve may be provided for each heating element or each sealed container, and the flow rate of the hydrogen-based gas introduced to each heating element may be controlled by the flow control valve.

[0150] Alternatively, the hydrogen-based gas that has permeated the heating element may be sampled, the sampled hydrogen-based gas may be analyzed, and the heating may be controlled based on the analysis results. For example, as shown in Figure 15, if we consider a configuration in which one heating element 90 is provided inside one sealed container 15, then in this case, there will be a configuration in which multiple sealed containers 15, each containing a heating element 90, are provided. Then, an analysis unit is provided for each sealed container 15 containing a heating element 90, and for each sealed container 15, the hydrogen-based gas that has permeated the heating element 90 is sampled, and the sampled hydrogen-based gas is analyzed by the analysis unit.

[0151] The analysis unit analyzes the hydrogen-based gas after it has permeated the heating element 90 to determine, for example, whether or not a specific gas generated by the exothermic reaction of the heating element 90 is contained in the hydrogen-based gas. With such a blast furnace hydrogen heating device, based on the analysis results from the analysis unit, the control unit 18 adjusts the flow rate of the hydrogen-based gas for each sealed container 15, thereby performing heat generation control to maintain the temperature of the heating element 90 at a temperature appropriate for heat generation.

[0152] In addition, the electrical resistance of the hydrogen storage metal or hydrogen storage alloy may be measured, and heat generation control may be performed based on the measured electrical resistance value. For example, in an example where multiple heating elements 90 are provided, an electrical resistance measuring unit is provided for each heating element 90, and the electrical resistance of the hydrogen storage metal or hydrogen storage alloy of the heating element 90 is measured by the electrical resistance measuring unit. Here, the heating element 90 is designed so that the more hydrogen the hydrogen storage metal or hydrogen storage alloy absorbs, the more likely the exothermic reaction is to occur. Also, the electrical resistance of the heating element 90 decreases as the hydrogen storage amount of the hydrogen storage metal or hydrogen storage alloy increases. Therefore, the amount of hydrogen absorbed can be estimated by measuring the electrical resistance of the hydrogen storage metal or hydrogen storage alloy of the heating element 90. The multiple electrical resistance measuring units are electrically connected to the control unit 18, and the measurement results of the electrical resistance are output to the control unit 18.

[0153] The control unit 18 can perform heat generation control to maintain the temperature of the heating element 90 at an appropriate temperature for heat generation by adjusting the circulation flow rate of the hydrogen-based gas for each heating element 90 based on the electrical resistance value measured by the electrical resistance measuring unit.

[0154] [12th variation] As shown in Figure 28, the hydrogen heating device 256 for the blast furnace includes a heating element 14, a plurality of temperature sensors 257a to 257c for detecting the temperature of the heating element 14, and a plurality of nozzles 258a to 258c for injecting hydrogen-based gas onto the surface of the heating element 14. Note that other components such as the blast furnace connected to the discharge line 30 will be omitted here to avoid repetition in the explanation, and the following description will focus on components that differ from the above embodiment and modified examples.

[0155] In this example, hydrogen-based gas is injected from multiple nozzles 258a to 258c onto a single heating element 14. Although Figure 28 shows three temperature sensors 257a to 257c and three nozzles 258a to 258c as an example, it is preferable that the temperature sensors 257a to 257c and the nozzles 258a to 258c be arranged in an array, such as a 3x3 configuration.

[0156] In this case, temperature sensors 257a to 257c are arranged at equal intervals in a two-dimensional manner on the back surface of the heating element 14. Each of the temperature sensors 257a to 257c has a defined temperature measurement target area where the sensor can detect temperature, and the temperature of each temperature measurement target area corresponding to each temperature sensor 257a to 257c is detected. For example, temperature sensor 257a detects the temperature of one predetermined temperature measurement target area on the back surface of the heating element 14. In the following description, when temperature sensors 257a to 257c are not distinguished, they will be referred to as temperature sensor 257.

[0157] Multiple nozzle sections 258a to 258c are arranged for each temperature measurement area. In the following description, when nozzle sections 258a to 258c are not distinguished, they will be referred to as nozzle section 258.

[0158] The temperature sensor 257 is electrically connected to the control unit 18 and outputs a signal to the control unit 18 corresponding to the temperature of the area to be measured. The nozzle unit 258 is attached to a mounting plate 259 provided on the inlet 23 of the sealed container 15. The nozzle unit 258 is connected to the introduction line 29 via the inlet 23 and injects hydrogen-based gas onto the surface of the heating element 14.

[0159] The blast furnace hydrogen heating device 256 further comprises a control unit 18, a gas introduction branch pipe 208, and a plurality of flow control valves 237. One end of the gas introduction branch pipe 208 is connected to the introduction line 29, and the other end branches off to connect to a plurality of nozzle sections 258. The gas introduction branch pipe 208 and the plurality of nozzle sections 258 are detachable. The plurality of flow control valves 237 are provided on the gas introduction branch pipe 208. The blast furnace hydrogen heating device 256 is configured to control the flow rate of hydrogen gas for each nozzle section 258 by providing one flow control valve 237 for each nozzle section 258.

[0160] The control unit 18 performs modification control to change the nozzle section 258 that injects hydrogen-based gas based on the temperatures detected by the multiple temperature sensors 257. The modification control will be described below.

[0161] When the blast furnace hydrogen heating device 256 starts operating, the control unit 18 sets the input power to the heater (not shown) and the opening of all flow control valves 237 to predetermined initial values. As a result, the temperature of the heating element 14 rises to a temperature suitable for heating. At the initial values, hydrogen-based gas is injected from all nozzles 258. The heater (not shown) is, for example, provided on the outer circumference of the sealed container 15, as in the blast furnace hydrogen heating device 11 of the above embodiment.

[0162] The control unit 18 acquires the temperature detected by each temperature sensor 257 and compares each acquired temperature with a reference temperature. The reference temperature is, for example, a temperature at which it can be estimated that no excess heat is being generated in the temperature measurement area. The reference temperature is pre-stored in the control unit 18 for each temperature measurement area.

[0163] The control unit 18 determines that no excess heat is being generated in the temperature measurement area where the temperature was obtained if the temperature obtained from the temperature sensor 257 is below the reference temperature. The control unit 18 maintains the input power to the heater (not shown) and the opening degree of the flow control valve 237 corresponding to the temperature measurement area where no excess heat is being generated at the initial settings. This makes it possible to encourage the generation of excess heat in the temperature measurement area where no excess heat is being generated among the heating elements 14.

[0164] On the other hand, if the temperature obtained from the temperature sensor 257 exceeds the reference temperature, the control unit 18 determines that excess heat is being generated in the temperature measurement area where the temperature was obtained. The control unit 18 increases the flow rate of hydrogen-based gas injected from the nozzle 258 into the temperature measurement area by increasing the opening of the flow control valve 237 corresponding to the temperature measurement area where excess heat has been determined to be occurring. The temperature of the temperature measurement area, which has risen due to the generation of excess heat, is returned to a temperature appropriate for heat generation by the increase in the flow rate of hydrogen-based gas. This makes it possible to increase the output of excess heat to the temperature measurement area where excess heat is being generated.

[0165] The hydrogen heating device 256 for blast furnaces changes the nozzle section 258 that injects hydrogen-based gas according to the heat generation status of the heating element 14, which changes over time, by performing change control for each of the multiple temperature measurement target areas. This stabilizes the output of excess heat from the heating element 14.

[0166] Furthermore, the hydrogen heating device 256 for the blast furnace may perform heat generation control on the temperature measurement area that is not emitting excess heat, rather than the temperature measurement area that is emitting excess heat. This increases the number of temperature measurement areas that are emitting excess heat, thereby increasing the output of excess heat for the entire heating element 14 and the entire device.

[0167] The hydrogen heating device 256 for blast furnaces may be equipped with multiple heating elements 14. By performing change control for each heating element 14, the output of excess heat from the entire device can be further increased.

[0168] [experiment] An experimental hydrogen heating apparatus for a blast furnace was prepared by partially modifying the configuration of the blast furnace hydrogen heating apparatus 121 (see Figure 17) of the sixth modified example described above. An experiment was conducted to evaluate the excess heat of a heating element consisting of a single laminate using the experimental hydrogen heating apparatus for a blast furnace. First, the experimental hydrogen heating apparatus for a blast furnace will be described, followed by a description of the experimental method and experimental results.

[0169] In the sixth modified example of the blast furnace hydrogen heating apparatus 121 described above, an electric heating wire serving as a heater 16b is wrapped around the outer circumference of the mounting pipe 125. However, in the experimental blast furnace hydrogen heating apparatus, the electric furnace was positioned to cover the outer circumference of the sealed container. Furthermore, the experimental blast furnace hydrogen heating apparatus used a heating element consisting of a single laminate with multilayer films on both sides of the support.

[0170] A specific description will be given of an experimental hydrogen heating device for blast furnaces. The experimental hydrogen heating device for blast furnaces comprises a heating element consisting of a single laminate that generates heat through the absorption and release of hydrogen, a sealed container having a first chamber and a second chamber separated by the heating element, and a temperature control unit that adjusts the temperature of the heating element.

[0171] The heating element will now be described. The heating element consists of a single laminate with multilayer films on both sides of a plate-shaped support. Two types of heating elements with different multilayer film configurations were fabricated and designated as Experimental Examples 26 and 27. A substrate made of Ni with a diameter of 20 mm and a thickness of 0.1 mm was used as the support. The support was prepared by vacuum annealing at 900°C for 72 hours in a vacuum, followed by etching both sides with concentrated nitric acid.

[0172] Multilayer films were formed on both sides of the support using an ion beam sputtering apparatus. The multilayer film in Experimental Example 26 has a first layer made of Cu and a second layer made of Ni. The number of layers in the stacked structure of the first and second layers in Experimental Example 26 (number of layers in the multilayer film) was set to 6. The multilayer film in Experimental Example 27 has a first layer made of Cu, a second layer made of Ni, and a third layer made of CaO. The number of layers in the stacked structure of the first, second, and third layers in Experimental Example 27 (number of layers in the multilayer film) was set to 6.

[0173] This section describes a sealed container. The sealed container consists of a quartz glass tube, vacuum piping for evacuating the inside of the quartz glass tube, and mounting pipes for installing a heating element inside the quartz glass tube. The quartz glass tube has a sealed end and an open base.

[0174] The vacuum piping is connected to the base end of the quartz glass tube. A recovery line for recovering the gas inside the quartz glass tube is connected to the vacuum piping. Here, in order to check whether or not excess heat is generated from the heating element, the hydrogen-based gas taken out of the sealed container is recovered by the recovery line and returned to the sealed container. The recovery line is equipped with a vacuum exhaust section having a turbomolecular pump and a dry pump, a pressure sensor for detecting the pressure inside the quartz glass tube, and a vacuum gauge for measuring the amount of hydrogen that permeates through the heating element (hydrogen permeation rate). Note that the vacuum exhaust section is not connected to the connecting pipe. Therefore, the inside of the connecting pipe is not evacuated.

[0175] The connecting pipe is inserted into the quartz glass tube through the vacuum piping, with one end positioned outside the vacuum piping (outside the quartz glass tube) and the other end positioned inside the quartz glass tube. The connecting pipe is made of stainless steel (SUS).

[0176] An introduction line for introducing hydrogen-based gas into the interior of the connecting pipe is connected to one end of the connecting pipe. The introduction line is equipped with a hydrogen cylinder for storing hydrogen-based gas, a pressure sensor for detecting the pressure inside the connecting pipe, a hydrogen supply valve for supplying and stopping the hydrogen-based gas to the connecting pipe, and a regulator valve for adjusting the pressure.

[0177] The other end of the mounting pipe is provided with a VCR fitting that allows for the attachment and detachment of a heating element. The VCR fitting has two leak holes that penetrate the inner and outer surfaces of the fitting at the location where the heating element is placed. The heating element is placed inside the VCR fitting, sandwiched between two SUS gaskets.

[0178] In a sealed container, a heating element separates the internal space of the connecting tube from the internal space of the quartz glass tube. The internal space of the connecting tube is pressurized by the introduction of a hydrogen-based gas. The internal space of the quartz glass tube is depressurized by the vacuum evacuation of the gas. As a result, the hydrogen pressure in the internal space of the connecting tube is made higher than the hydrogen pressure in the internal space of the quartz glass tube. The internal space of the connecting tube functions as the first chamber, and the internal space of the quartz glass tube functions as the second chamber.

[0179] A pressure difference is created on both sides of the heating element, causing hydrogen to permeate from the internal space of the connecting pipe (high pressure side) to the internal space of the quartz glass tube (low pressure side). As described above, in the process of permeating hydrogen, the heating element generates heat by absorbing hydrogen from one side (front surface) located on the high-pressure side, and generates excess heat by releasing hydrogen from the other side (back surface) located on the low-pressure side.

[0180] The temperature control unit will now be described. The temperature control unit includes a temperature sensor for detecting the temperature of the heating element, a heater for heating the heating element, and an output control unit that controls the output of the heater based on the temperature detected by the temperature sensor. A thermocouple (K-type sheathed thermocouple) was used as the temperature sensor. In the experiment, two thermocouples (a first thermocouple and a second thermocouple) were prepared and inserted into the two leak holes of the VCR joint. The two thermocouples were brought into contact with the heating element, and the temperature of the heating element was measured. An electric furnace was used as the heater. The electric furnace was positioned to cover the outer circumference of the quartz glass tube. A control thermocouple was provided in the electric furnace. The output control unit is electrically connected to the control thermocouple and the electric furnace, and drives the electric furnace at a predetermined voltage based on the temperature detected by the control thermocouple. The electric furnace is driven by a 100V AC power supply. The input power to the electric furnace was measured using a power meter.

[0181] Next, the experimental method and results will be described. The heating element was sandwiched between two SUS gaskets, fixed to the other end of the mounting pipe using a VCR fitting, and placed inside a quartz glass tube. Before starting the experiment, the heating element was baked at 300°C for three days.

[0182] The experiment began after the baking process described above. The hydrogen supply valve was opened to supply hydrogen-based gas to the connecting pipe, and the pressure in the first chamber (internal space of the connecting pipe) (also called the hydrogen supply pressure) was adjusted to 100 kPa using the regulator valve. The quartz glass tube was evacuated, and the pressure in the second chamber (internal space of the quartz glass tube) was set to 1 × 10⁻⁶ kPa. -4 The temperature was adjusted to [Pa]. The electric furnace was driven, and the heating element was heated to the predetermined set temperature. The set temperature was changed approximately every half day, gradually increasing within the range of 300°C to 900°C.

[0183] A reference experiment was conducted prior to the experiments in Experimental Examples 26 and 27. In the reference experiment, a reference sample consisting only of a support (Ni substrate with a diameter of 20 mm and a thickness of 0.1 mm) was prepared and used. The reference experiment was performed twice, with a different reference sample each time.

[0184] Figure 29 is a graph showing the relationship between hydrogen permeation rate, hydrogen supply pressure, and sample temperature in the reference experiment. In Figure 29, the horizontal axis represents time (h), the first vertical axis on the left represents hydrogen permeation rate (SCCM), and the second vertical axis on the right represents hydrogen supply pressure (kPa), the temperature of the first sample (°C), and the temperature of the second sample (°C). The hydrogen permeation rate was calculated from the values ​​of a flow-calibrated vacuum gauge. The temperature of the first sample is the temperature detected by the first thermocouple, and the temperature of the second sample is the temperature detected by the second thermocouple. From Figure 29, it was confirmed that the temperature of the first sample and the temperature of the second sample were approximately the same, indicating that the temperature of the reference experiment sample was accurately measured. It was also confirmed that the hydrogen permeation rate increased in accordance with the rise in the temperature of the reference experiment sample. Note that Figure 29 shows the results of the first reference experiment. The results of the second reference experiment were approximately the same as those of the first reference experiment, so the explanation is omitted.

[0185] Figure 30 is a graph showing the relationship between sample temperature and input power in the reference experiment. In Figure 30, the horizontal axis represents sample temperature (°C), and the vertical axis represents input power (W). Input power refers to the power input to the electric furnace. Because the measured values ​​of the power meter fluctuate significantly due to the ON / OFF control of the AC power supply, the measured values ​​were accumulated for each set temperature, and the input power was calculated based on the slope. The calculation of input power was performed in the region where sufficient time had passed after changing the set temperature and the measured values ​​of the power meter had stabilized. For each of the aforementioned regions, the average value of the detected temperature of the first thermocouple and the average value of the detected temperature of the second thermocouple were calculated, and the average of these two average values ​​was taken as the sample temperature. Figure 30 plots the results of two reference experiments and is a calibration curve created using the least squares method. In Figure 30, Y represents the function representing the calibration curve, M0 represents the constant term, M1 represents the coefficient of the first order, M2 represents the coefficient of the second order, and R represents the correlation coefficient. The excess heat in Experimental Example 26 and Experimental Example 27 was evaluated based on the results of this reference experiment.

[0186] Figure 31 is a graph showing the relationship between the heating element temperature and excess heat in Experimental Example 26. In Figure 31, the horizontal axis represents the heating element temperature (°C), and the vertical axis represents excess heat (W). The average values ​​of the detected temperatures of the first thermocouple and the second thermocouple were determined using the same method as for calculating the sample temperature in the reference experiment, and the average of these two average values ​​was taken as the heating element temperature. The method for determining excess heat is explained below. First, the heating element temperature at a specific input power is measured (referred to as the measured temperature). Next, the input power of the reference experiment corresponding to the measured temperature (referred to as the converted power) is determined using the calibration curve shown in Figure 30. Then, the difference between the converted power and the specific input power is calculated, and this is taken as the power of the excess heat. The method for calculating the specific input power is the same as the method for calculating the input power in the reference experiment. In Figure 31, the power of the excess heat is denoted as "Excess Heat (W)". From Figure 31, it was confirmed that excess heat is generated when the heating element temperature is in the range of 300°C to 900°C. It was confirmed that the excess heat was approximately 2W at temperatures below 600°C, increased above 700°C, and reached about 10W around 800°C.

[0187] Figure 32 is a graph showing the relationship between the heating element temperature and excess heat in Experimental Example 27. In Figure 32, the horizontal axis represents the heating element temperature (°C), and the vertical axis represents the excess heat (W). From Figure 32, it was confirmed that excess heat is generated when the heating element temperature is in the range of 200°C to 900°C. The excess heat is approximately 4W at its maximum in the range of 200°C to 600°C, increases above 700°C, and exceeds 20W around 800°C.

[0188] Comparing Experiment 26 and Experiment 27, it can be seen that below 600°C, Experiment 27 tends to generate more excess heat. Both Experiment 26 and Experiment 27 tend to increase excess heat above 700°C. Above 700°C, the excess heat in Experiment 27 increases to approximately twice that of Experiment 26.

[0189] When calculating the excess heat per unit area at around 800°C for Experimental Example 11 (see Figure 12), Experimental Example 26 (see Figure 31), and Experimental Example 27 (see Figure 32), the result for Experimental Example 11 is approximately 0.5 W / cm². 2 In experimental example 26, the power was approximately 5 W / cm². 2 In experimental example 27, the power was approximately 10 W / cm². 2 This result shows that, compared to experimental example 11, experimental example 26 generated approximately 10 times more excess heat, and experimental example 27 generated approximately 20 times more excess heat.

[0190] From the above, it can be seen that even a heating element consisting of only one laminate generates excess heat, and this excess heat can heat hydrogen-based gases. Furthermore, as the number of laminates increases, the thickness of the heating element increases, and the distance the hydrogen-based gas has to pass through the heating element increases. As a result, the heating time also increases, and the temperature of the hydrogen-based gas after passing through the heating element becomes higher as the number of laminates increases. Therefore, it can be seen that the temperature of the hydrogen-based gas heated by the heating element can be adjusted by adjusting the number of laminates.

[0191] [Second Embodiment] In the second embodiment, the partial pressure of hydrogen in the gas introduced into the first chamber is different from the partial pressure of hydrogen in the gas introduced into the second chamber, and the pressure difference of hydrogen between the first and second chambers is used to allow hydrogen to permeate the heating element. In the second embodiment, "hydrogen pressure" refers to "partial pressure of hydrogen."

[0192] As shown in Figure 33, the blast furnace equipment 265 comprises a blast furnace hydrogen heating device 266 and a blast furnace 12. The blast furnace hydrogen heating device 266 comprises a heating element 268 that generates heat by the absorption and release of hydrogen, a sealed container 271 having a first chamber 269 and a second chamber 270 separated by the heating element 268, and a temperature control unit 272 that adjusts the temperature of the heating element 268. Note that the structure separating the first chamber 269 and the second chamber 270 is not limited to consisting only of the heating element 268, but may also be a wall structure in which part is the heating element 268 and the other part is a metal or oxide that shields hydrogen.

[0193] The heating element 268 is formed in a bottomed cylindrical shape. The heating element 268 can have a similar configuration to the heating element 90 shown in Figure 14, for example, and consists of a predetermined number of laminates 90a stacked together. That is, the heating element 268 is formed by stacking a predetermined number of laminates, each having a multilayer film on the outer surface of a bottomed cylindrical support, with the support and multilayer film arranged alternately from the inside to the outside. Alternatively, the multilayer film may be provided on the inner surface of the support, with the multilayer film and support arranged alternately from the inside to the outside, or the multilayer film may be provided on both the inner and outer surfaces of the innermost support. Furthermore, although this embodiment shows a configuration with multiple laminates 90a stacked together, a configuration with only one laminate 90a is also possible.

[0194] The support is not limited to a bottomed cylindrical shape, but may also be a bottomed rectangular tube or a flat plate. The support is preferably made of a material that is permeable to hydrogen and has heat resistance and pressure resistance, and can be formed from the same material as the support 61, for example. The multilayer film can have the same configuration as the multilayer film 62, for example. In this example, there is one heating element 268, but there may be two or more.

[0195] The sealed container 271 is a hollow container that houses the heating element 268 inside. The sealed container 271 is preferably made of a material that has heat resistance and pressure resistance. Examples of materials for the sealed container 271 include metals and ceramics. Examples of metals include Ni, Cu, Ti, carbon steel, austenitic stainless steel, heat-resistant non-ferrous alloy steel, and ceramics. Examples of ceramics include Al2O3, SiO2, SiC, and ZnO2. It is desirable to cover the outer periphery of the sealed container 271 with an insulating material. In this example, there is one sealed container 271 containing the heating element 268, but there may be two or more.

[0196] The first chamber 269 is formed by the inner surface of the heating element 268. The first chamber 269 has an inlet 274 that connects to the hydrogen introduction line 273. The hydrogen introduction line 273 is equipped with a hydrogen tank 275 for storing hydrogen-based gas. Hydrogen-based gas flowing through the hydrogen introduction line 273 is introduced into the first chamber 269 through the inlet 274.

[0197] The second chamber 270 is formed by the outer surface of the heating element 268 and the inner surface of the sealed container 271. The second chamber 270 has an inlet 277 connected to the hydrogen tank 280 and an outlet 278 connected to the outlet line 276. From the inlet 277, a circulating blower 279 introduces hydrogen-based gas from the hydrogen tank 280 into the second chamber 270 (sealed container 271). The outlet line 276 is connected to the blast furnace 12.

[0198] The partial pressure of hydrogen in the hydrogen-based gas introduced into the first chamber 269 and the partial pressure of hydrogen in the hydrogen-based gas introduced into the second chamber 270 are measured by a hydrogen sensor (not shown). It is desirable that the partial pressure of hydrogen in the first chamber 269 be, for example, 10 to 10,000 times that of the partial pressure of hydrogen in the second chamber 270. As an example, the partial pressure of hydrogen in the first chamber 269 is set to 10 kPa to 1 MPa, and the partial pressure of hydrogen in the second chamber 270 is set to 1 Pa to 10 kPa. This causes the hydrogen in the first chamber 269 to permeate through the heating element 268 and move to the second chamber 270. The heating element 268 generates excess heat as hydrogen permeates through it. By circulating a heat transfer medium into the second chamber 270, the excess heat from the heating element 268 can be transferred to the heat transfer medium, and the partial pressure of hydrogen in the second chamber 270 can be lower than that in the first chamber 269.

[0199] The blast furnace hydrogen heating device 266 has a control unit (not shown) configured to control the hydrogen partial pressure of the first chamber 269 and the hydrogen partial pressure of the second chamber 270. For example, by increasing the hydrogen partial pressure of the first chamber 269 and increasing the difference in hydrogen partial pressure between the first chamber 269 and the second chamber 270, the amount of hydrogen permeation can be increased, promoting the generation of excess heat from the heating element 268. Alternatively, by decreasing the hydrogen partial pressure of the first chamber 269 and reducing the difference in hydrogen partial pressure between the first chamber 269 and the second chamber 270, the amount of hydrogen permeation can be decreased, suppressing the generation of excess heat from the heating element 268. Instead of changing the hydrogen partial pressure of the first chamber 269, it is also possible to promote or suppress the generation of excess heat from the heating element 268 by decreasing or increasing the hydrogen partial pressure of the second chamber 270. Both the hydrogen partial pressure of the first chamber 269 and the hydrogen partial pressure of the second chamber 270 may be changed. Furthermore, the generation of excess heat from the heating element 268 can be adjusted by changing the flow rate and temperature of the hydrogen-based gas at the inlet 277.

[0200] The temperature control unit 272 includes a temperature sensor 281 for detecting the temperature of the heating element 268, a heater 282 for heating the heating element 268, and an output control unit 283 that controls the output of the heater 282 based on the temperature detected by the temperature sensor 281. In Figure 33, the temperature sensor 281 is provided on the outer surface of the heating element 268, but it may also be configured to detect the temperature of a part of the heating element 268 from which its temperature can be estimated. The heater 282 is activated when the blast furnace hydrogen heating device 266 starts up or when the temperature of the heating element 268 drops. The heater 282 heats the hydrogen-based gas from the hydrogen tank 280, introduces the heated hydrogen-based gas into the second chamber 270, and heats the heating element 268.

[0201] The blast furnace hydrogen heating device 266 generates excess heat from the heating element 268, and sends the hydrogen-based gas heated by the heating element 268 to the blast furnace 12 via the discharge line 276, where it can be used as a reducing gas in the blast furnace 12.

[0202] As described above, the blast furnace hydrogen heating device 266 is configured to raise the temperature of the hydrogen-based gas to a predetermined temperature, and is also configured to allow hydrogen to permeate the heating element 268 by utilizing the difference in hydrogen partial pressure between the first chamber 269 and the second chamber 270. Therefore, the blast furnace hydrogen heating device 266 achieves the same effects as the above embodiment, and does not require the generation of an apparent pressure difference between the first chamber 269 and the second chamber 270 obtained by a pressure sensor, for example, by creating a vacuum in the second chamber 270. Consequently, the risk of deformation or damage to the blast furnace hydrogen heating device 266 is reduced.

[0203] In the hydrogen heating device 266 for blast furnaces of this embodiment, since it is possible to heat hydrogen-based gas without consuming a large amount of energy, the amount of CO2 generated can be suppressed accordingly. Therefore, in the hydrogen heating device for blast furnaces, by using the hydrogen-based gas heated in this way as a reducing gas in the blast furnace during blast furnace operation, the amount of CO2 generated can be suppressed even when hydrogen-based gas is used as a reducing gas in the blast furnace.

[0204] [Third Embodiment] In the first and second embodiments described above, a hydrogen heating device for a blast furnace was described in which a first chamber and a second chamber are provided inside a sealed container, and a hydrogen-based gas is circulated from the first chamber to the second chamber via a heating element, with the hydrogen-based gas permeating the heating element, and the hydrogen-based gas is heated by the excess heat generated by the heating element. However, the present invention is not limited to this. For example, as shown in Figure 34, a hydrogen heating device for a blast furnace 301 may be provided in which, instead of providing a first chamber and a second chamber inside the sealed container 302, excess heat is generated in a heating element 14 provided inside the sealed container 302, and the temperature of the hydrogen-based gas is adjusted by adjusting the number of layers of the laminate provided on the heating element.

[0205] Figure 34 shows a schematic diagram of a hydrogen heating device 301 for a blast furnace according to the third embodiment. In this case, the blast furnace equipment 300 comprises a hydrogen heating device 301 for a blast furnace and a blast furnace 12. The hydrogen heating device 301 for a blast furnace comprises a sealed container 302 into which a hydrogen-based gas is introduced, a heat-generating structure 303 provided inside the sealed container 302, and a temperature control unit 320 that adjusts the temperature of the heating element 14 of the heat-generating structure 303. Similar to the first embodiment described above, in the hydrogen heating device 301 for a blast furnace, after the hydrogen-based gas is introduced into the sealed container 302, the heating element 14 in the heat-generating structure 303 is heated by the temperature control unit 320, thereby generating excess heat in the heating element 14. Note that the configuration of the heating element 14 is the same as in the first embodiment described above, so to avoid duplication of explanation, its description is omitted here.

[0206] The sealed container 302 is made of, for example, stainless steel (SUS306 or SUS316). 302a is a window made of a transparent material such as Kovar glass, allowing the operator to directly visually inspect the contents of the sealed container 302 while maintaining its airtight state. The sealed container 302 is provided with an introduction line 316, through which hydrogen-based gas is introduced into the sealed container 302 via regulating valves 317a and 317b. Subsequently, the introduction of hydrogen-based gas from the introduction line 316 is stopped by the regulating valves 317a and 317b, and a certain amount of hydrogen-based gas is stored inside the sealed container 302. 319 is a dry pump, which, if necessary, can discharge the gas inside the sealed container 302 to the outside via the outlet line 318 and regulating valve 317c to perform vacuum evacuation, pressure adjustment, etc.

[0207] The temperature control unit 320 adjusts the temperature of the heating element 14 and maintains it at a temperature suitable for heating. The temperature suitable for heating in the heating element 14 is, for example, within the range of 50°C to 1000°C. The temperature control unit 320 includes temperature sensors 311a, 311b, 312a, 312b, and 312c, and a heater (not shown) for heating the heating element 14.

[0208] In this embodiment, temperature sensors 311a and 311b are provided along the inner wall of the sealed container 302 and measure the temperature of the inner wall. The other temperature sensors 312a to 312c are provided in the holder 304 that holds the heating element 14 in the heating structure 303 and measure the temperature of the holder 304. The temperature sensors 312a to 312c are of different lengths, and for example, they measure the temperature of the lower section close to the heating element 14, the upper section further away from the heating element 14, and the middle section located between the lower and upper sections in the holder 304.

[0209] The temperature sensors 311a, 311b, 312a, 312b, and 312c are electrically connected to a control unit 18 (not shown) and output a signal corresponding to the detected temperature to the control unit.

[0210] The heater that heats the heating element 14 is, for example, an electric resistance heating wire, which is wrapped around the outer circumference of the sealed container 302 or installed on the holder 304. The heater is electrically connected to the power supply 313 and generates heat when power is input from the power supply 313. Alternatively, the heater may be an electric furnace positioned to cover the outer circumference of the sealed container 302. In addition, a heater may be provided in the introduction line 316, and the heating element 14 may be heated by heating the hydrogen-based gas flowing through the introduction line 316 with the heater.

[0211] In this embodiment, for example, a heater is provided in the holder 304, and the heater and the power supply 313 are connected by wirings 310a and 310b. 314 is a current and voltage meter provided in the wirings 310a and 310b, which can measure the input current and input power applied to the heater when heating the heater.

[0212] Next, the heating structure 303 will be described. As shown in Figure 35, the heating structure 303 has a holder 304 composed of a pair of holder halves 304a and 304b, and a heating element 14 made up of multiple laminates 14a consisting of a support 61 and a multilayer film 62 is sandwiched between the holder halves 304a and 304b. The heater is not shown, but for example, it is a plate-shaped ceramic heater and is provided at a predetermined position in the holder 304. Alternatively, the heater may be sandwiched together with the heating element 14 between the holder halves 304a and 304b.

[0213] One half of the holder 304, 304a, is formed from ceramics in a rectangular shape, with an opening 309a at a predetermined position. In the first half of the holder 304a, a heating element 14 is placed in the opening 309a, exposing the heating element 14 from the area of ​​the opening 309a. The other half of the holder 304b is also formed from ceramics in a rectangular shape, similar to the first half of the holder 304a. The other half of the holder 304b has an opening 309b at a position that overlaps with the opening 309a of the first half of the holder 304a when it is stacked and integrated with the first half of the holder 304a.

[0214] The other holder half 304b is provided with a stepped portion 309c on the periphery of the opening 309b of the contact surface 309d that abuts against the other holder half 304a. The heating element 14 is fitted into and positioned in the stepped portion 309c. As a result, in the other holder half 304b, the heating element 14 is positioned in the opening 309b by being fitted into the stepped portion 309c, and the heating element 14 is exposed from the area of ​​the opening 309b. When the holder halves 304a and 304b are stacked on top of each other, the heating element 14 fitted into the stepped portion 309c is held down by the contact surface on the periphery of the opening 309a of one holder half 304a, and is housed within the stepped portion 309c and built into the holder 304.

[0215] As described above, in the hydrogen heating apparatus 301 for blast furnaces according to the third embodiment, hydrogen is absorbed and released in the heating element 14, and heat is generated by the absorption of hydrogen in the heating element 14, as well as by the release of hydrogen, resulting in excess heat. The hydrogen-based gas is heated in the heating element 14 by the excess heat generated in the heating element 14. The thicker the heating element 14, the easier the hydrogen-based gas is heated by the excess heat generated in the heating element 14, and the higher the temperature of the hydrogen-based gas.

[0216] Therefore, in this blast furnace hydrogen heating device 301, a hydrogen-based gas at a predetermined temperature can be obtained, similar to the first embodiment described above. Thus, in the blast furnace hydrogen heating device 301, the hydrogen-based gas is heated using a heating element that generates heat through the absorption and release of hydrogen. Therefore, the hydrogen-based gas heated using an inexpensive, clean, and safe thermal energy source can be supplied to the blast furnace 12 as a reducing gas.

[0217] In this embodiment, a configuration in which multiple laminates 14a are stacked is shown, but a configuration having only one laminate 14a is also possible.

[0218] In the hydrogen heating apparatus for blast furnaces of this embodiment, since it is possible to heat hydrogen-based gases without consuming a large amount of energy, the amount of CO2 generated can be suppressed accordingly. Therefore, in the hydrogen heating apparatus for blast furnaces, by using the hydrogen-based gas heated in this way as a reducing gas in the blast furnace during blast furnace operation, the amount of CO2 generated can be suppressed even when hydrogen-based gas is used as a reducing gas in the blast furnace.

[0219] Furthermore, the heating element is not limited to being formed in the shape of a plate or a cylinder. For example, each laminate of the heating element may consist of a powder made of a hydrogen-absorbing metal or hydrogen-absorbing alloy, housed in a container made of a hydrogen-permeable material (e.g., a porous material, a hydrogen-permeable membrane, and a proton conductor).

[0220] The hydrogen heating apparatus for blast furnaces is not limited to those described in the above embodiments and modifications, and may be configured by appropriately combining the hydrogen heating apparatus for blast furnaces of the above embodiments and modifications. Furthermore, for example, although a pump 33 is provided in the introduction line 29 to bring the inside of the sealed container 15 to a predetermined pressure and send the hydrogen-based gas to the blast furnace 12, the present invention is not limited to this, and a pump 33 may also be provided in the discharge line 30 to bring the inside of the sealed container 15 to a predetermined pressure and send the hydrogen-based gas to the blast furnace 12.

[0221] Furthermore, in the above embodiments, a case was described in which a heating element having a laminate is applied by stacking multiple laminates, each laminated with a support and a multilayer film, but the present invention is not limited to this. In any embodiment, for example, a heating element having one or more laminates may be used, such as using a heating element consisting of a single laminate (one layer each of support and multilayer film). [Explanation of Symbols]

[0222] 11,96,121,146,156,166,191,256,266,301 Hydrogen heating equipment for blast furnaces 12 Blast Furnace 14,19,74,75,80,90,98,160,268 Heating element 15,123,173,193,271,302 airtight containers 16 Temperature control section 21,126,184,194,269 Room 1 22,127,185,195,270 Room 2 61,91,91a Support 62,92 Multilayer film 71 1st layer 72 2nd layer 77 3rd layer 82 4th layer

Claims

1. A hydrogen heating device for blast furnaces that heats hydrogen-containing hydrogen-based gas and supplies it to the blast furnace, A sealed container into which the hydrogen gas is introduced, A heat-generating element provided inside the sealed container, which generates heat through the absorption and release of hydrogen, A temperature control unit that adjusts the temperature of the heating element, Inlet line and outlet line, Equipped with, The heating element has one or more laminates comprising a support formed of at least one of a porous material, a hydrogen permeable membrane, and a proton conductor, and a multilayer film supported on the support. The multilayer film comprises a first layer formed of a hydrogen-absorbing metal or hydrogen-absorbing alloy with a thickness of less than 1000 nm, and a second layer formed of a hydrogen-absorbing metal, hydrogen-absorbing alloy, or ceramic different from the first layer, with a thickness of less than 1000 nm. The hydrogen-based gas is heated to a predetermined temperature by the heating element. The sealed container is divided into a first chamber and a second chamber by the heating element. The first chamber and the second chamber have different hydrogen pressures, and by utilizing the difference in hydrogen pressure between the first chamber and the second chamber, the hydrogen is permeated into the heating element, thereby generating heat from the heating element. The first chamber has an inlet into which the hydrogen-based gas is introduced. The second chamber has an outlet from which the hydrogen-based gas is discharged. The hydrogen pressure in the first chamber is set higher than the hydrogen pressure in the second chamber. The introduction line connects the hydrogen tank in which the hydrogen-based gas is stored to the inlet of the first chamber, and introduces the hydrogen-based gas from the hydrogen tank into the first chamber. The discharge line connects the outlet of the second chamber to the blast furnace and supplies the hydrogen-based gas, which has been heated to a predetermined temperature by the heating element as it permeates from the first chamber to the second chamber via the heating element, to the blast furnace. Hydrogen heating device for blast furnaces.

2. Multiple of the aforementioned laminates are stacked, A hydrogen heating apparatus for a blast furnace according to claim 1.

3. The heating element is formed in a bottomed cylindrical shape, The first chamber is formed by the inner surface of the heating element, The second chamber is formed by the outer surface of the heating element and the inner surface of the sealed container. A hydrogen heating apparatus for a blast furnace according to claim 1.

4. The first chamber has a non-permeable gas recovery port, The system includes a non-permeable gas recovery line that connects the non-permeable gas recovery port of the first chamber to the hydrogen tank, and recovers the non-permeable gas from the non-permeable gas recovery port that did not permeate the heating element among the hydrogen-based gas introduced into the first chamber from the inlet, and returns it to the hydrogen tank. A hydrogen heating apparatus for a blast furnace according to claim 1.

5. The non-permeable gas recovery line includes a non-permeable gas flow control unit that controls the flow rate of the non-permeable gas based on the temperature of the heating element detected by a temperature sensor provided in the temperature control unit. The hydrogen heating apparatus for a blast furnace according to claim 4.

6. The following is provided between the inlet and the heating element, and includes a nozzle that injects the hydrogen-based gas, which is led out from the inlet into the inside of the sealed container, onto the heating element. A hydrogen heating apparatus for a blast furnace according to claim 1.

7. The heating element is formed in a bottomed cylindrical shape, The nozzle portion has a plurality of injection ports arranged in the axial direction of the heating element, and the hydrogen-based gas is injected from the plurality of injection ports onto the entire inner surface of the heating element. The hydrogen heating apparatus for a blast furnace according to claim 6.

8. The heating element is formed in the shape of a plate, The nozzle portion injects the hydrogen-based gas onto the entire surface of one side of the heating element. The hydrogen heating apparatus for a blast furnace according to claim 6.

9. The heating element is formed in a cylindrical shape with both ends open, one end connected to the inlet and the other end connected to the non-permeable gas recovery line. A hydrogen heating apparatus for a blast furnace according to claim 4 or 5.

10. The temperature control unit heats the hydrogen-based gas flowing through the introduction line with a heater provided in the introduction line, and heats the heating element with the hydrogen-based gas that has been heated by the heater and introduced into the first chamber through the introduction port. A hydrogen heating apparatus for a blast furnace according to any one of claims 1 to 9.

11. A first hydrogen storage and release section is provided in the first chamber, which is made of a hydrogen storage metal or hydrogen storage alloy and is used for the storage and release of hydrogen, A second hydrogen storage and release section is provided in the second chamber, which is made of a hydrogen storage metal or hydrogen storage alloy and is used for the storage and release of hydrogen, The system includes a hydrogen pressure control unit that controls switching between a first mode in which the hydrogen pressure in the first chamber is higher than the hydrogen pressure in the second chamber, and a second mode in which the hydrogen pressure in the second chamber is higher than the hydrogen pressure in the first chamber. A hydrogen heating apparatus for a blast furnace according to claim 1.

12. The hydrogen pressure control unit, In the first mode, the first hydrogen storage and release section is heated, and the second hydrogen storage and release section is cooled. In the second mode, the second hydrogen storage and release section is heated, and the first hydrogen storage and release section is cooled. The hydrogen heating apparatus for a blast furnace according to claim 11.

13. The sealed container houses a plurality of the heating elements, Multiple heating elements are formed in a plate shape and arranged with gaps between them so that their surfaces face each other. The first and second chambers are provided in multiple locations inside the sealed container and are arranged alternately in the direction of the arrangement of the multiple heating elements. A hydrogen heating apparatus for a blast furnace according to claim 1.

14. The first layer is formed from Ni, Pd, Cu, Mn, Cr, Fe, Mg, Co, or an alloy thereof. The second layer is formed from one of the following: Ni, Pd, Cu, Mn, Cr, Fe, Mg, Co, alloys thereof, or SiC. A hydrogen heating apparatus for a blast furnace according to any one of claims 1 to 13.

15. The multilayer film has, in addition to the first and second layers, a third layer formed from a hydrogen-absorbing metal, hydrogen-absorbing alloy, or ceramic different from the first and second layers, and having a thickness of less than 1000 nm. A hydrogen heating apparatus for a blast furnace according to any one of claims 1 to 14.

16. The aforementioned third layer is CaO, Y 2 O 3 TiC, LaB 6 It is formed from either SrO or BaO. The hydrogen heating apparatus for a blast furnace according to claim 15.

17. The multilayer film has, in addition to the first, second, and third layers, a fourth layer formed from a hydrogen-absorbing metal, hydrogen-absorbing alloy, or ceramic different from the first, second, and third layers, and having a thickness of less than 1000 nm. A hydrogen heating apparatus for a blast furnace according to claim 15 or 16.

18. The fourth layer consists of Ni, Pd, Cu, Cr, Fe, Mg, Co, their alloys, SiC, CaO, and Y. 2 O 3 TiC, LaB 6 It is formed from either SrO or BaO. The hydrogen heating apparatus for a blast furnace according to claim 17.

19. A blast furnace hydrogen heating method comprising heating a hydrogen-containing hydrogen gas using a blast furnace hydrogen heating apparatus according to any one of claims 1 to 18 and supplying it to a blast furnace, An introduction step in which the hydrogen-based gas is introduced into the sealed container, A temperature control step in which the temperature of the heating element provided inside the sealed container is controlled by the temperature control unit, A heat generation step in which heat is generated from the heating element by the absorption and release of hydrogen in the heating element, Includes, The hydrogen-based gas is heated to a predetermined temperature by the heating element that generates heat in the heat generation step, and the hydrogen-based gas heated to the predetermined temperature is supplied to the blast furnace via the outlet line of the hydrogen heating device for the blast furnace. A hydrogen heating method for blast furnaces.

20. A blast furnace operation method that includes the step of blowing a hydrogen-based gas into the interior of the blast furnace from the tuyeres of the blast furnace as a reducing gas, The hydrogen-based gas is a hydrogen-based gas heated by a hydrogen heating apparatus for blast furnaces according to any one of claims 1 to 18. In the blowing step, the hydrogen-based gas, heated to a predetermined temperature by the heating element of the hydrogen heating device for the blast furnace, is supplied to the blast furnace via the discharge line. Blast furnace operation methods.

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