Hydrogen generation apparatus

Abstract

To provide a technique for accurately detecting temperature at a desired position in a hydrogen generation apparatus.SOLUTION: A hydrogen generation apparatus 100 comprises: an outer cylinder 103; a reforming unit 112 disposed inside the outer cylinder 103 and generating hydrogen-containing gas from a raw material gas and water; a temperature sensor 121 disposed so that a tip portion thereof contacts an outer surface 103b of the outer cylinder 103; and an absorption portion 128 disposed outside the outer cylinder 103 and absorbing expansion and contraction of the temperature sensor 121 so that a contact state between a tip portion 121a of the temperature sensor 121 and the outer surface 103b of the outer cylinder 103 is maintained.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a hydrogen generation device. [Background technology]

[0002] Patent Document 1 discloses a hydrogen production device that has a housing provided at the bottom of an outer cylinder, a reforming temperature measurement unit configured by housing a temperature sensor in the housing for detecting the temperature of the reforming unit, and a cover plate that fixes a flange of the housing to fix the temperature sensor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-176398 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present disclosure is to provide a technique for accurately detecting the temperature at a desired position in a hydrogen generation device. [Means for solving the problem]

[0005] The present disclosure provides: A container and a reforming unit disposed inside the vessel and generating a hydrogen-containing gas from a raw material gas and water; a temperature sensor disposed so that a tip thereof is in contact with the outer surface of the container; an absorbing portion disposed outside the container and absorbing expansion and contraction of the temperature sensor so that the tip of the temperature sensor is maintained in contact with the outer surface of the container; The present invention provides a hydrogen generating device comprising: [Effects of the Invention]

[0006] According to the present disclosure, the temperature of the reforming section in the hydrogen generation device can be accurately detected. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a longitudinal cross-sectional view of a hydrogen generation device according to a first embodiment. [Figure 2] Enlarged view of part of Figure 1 [Figure 3] FIG. 1 is a plan view of the bottom of the outer cylinder of the hydrogen generation device according to the first embodiment. [Figure 4A] First diagram to explain the expansion and contraction of the temperature sensor due to thermal changes [Figure 4B] Second diagram to explain expansion and contraction of the temperature sensor due to thermal changes [Figure 4C] The third figure illustrates the expansion and contraction of the temperature sensor due to thermal changes. [Figure 4D] The fourth figure illustrates the expansion and contraction of the temperature sensor due to thermal changes. [Figure 5] 10 is a longitudinal cross-sectional view of a hydrogen generation device according to a second embodiment. [Figure 6] FIG. 10 is a plan view of the bottom of the outer cylinder of the hydrogen generation device according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] (Findings that formed the basis of this disclosure) Because the temperature required for steam reforming is high, the surface of the hydrogen generator's container is also hot. Therefore, if a temperature sensor is fixed directly to the container's surface, heat is transferred from the container to the temperature sensor, causing the temperature sensor to expand. When the hydrogen generator is stopped, the temperature sensor contracts. Because the temperature sensor expands and contracts, it is difficult to maintain contact between the temperature sensor and the container's surface. This makes it difficult to accurately detect the temperature.

[0009] In the prior art (Patent Document 1), a tube was installed at the bottom of the outer cylinder of the hydrogen generator, and a temperature sensor was inserted into the tube, which detected the temperature of the reforming section and controlled the hydrogen generator. However, due to dimensional tolerances of the tube and the temperature sensor, the position of the tip of the temperature sensor varied from product to product, which could result in differences in the detected temperature.

[0010] Based on these findings, the present inventors have come to form the subject of the present disclosure.

[0011] Therefore, an object of the present disclosure is to provide a technique for accurately detecting the temperature at a desired position in a hydrogen generation device.

[0012] Hereinafter, embodiments will be described in detail with reference to the drawings. However, unnecessary detailed description may be omitted. For example, detailed description of already well-known matters or redundant description of substantially the same configuration may be omitted.

[0013] The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter recited in the claims.

[0014] (Embodiment 1) Hereinafter, the first embodiment will be described with reference to FIGS.

[0015] [1-1.Configuration] Fig. 1 is a longitudinal sectional view of the hydrogen generator of Embodiment 1. In Fig. 1, the hydrogen generator 100 includes a heating section 110, an evaporation section 111, a reforming section 112, a partition wall 101, an inner cylinder 102, an outer cylinder 103, a heat insulating member 120, a temperature sensor 121, and an elastic body 122.

[0016] The hydrogen generator 100 of this embodiment can be applied to, for example, a polymer electrolyte fuel cell (PEFC).

[0017] The heating unit 110 is housed inside the outer cylinder 103 and heats the inside of the hydrogen generator 100. In this embodiment, the heating unit 110 is a burner that burns combustible gas. The burner burns fuel gas, which is a mixture of combustion air and fuel. The burner forms a downward flame.

[0018] The partition wall 101 is a cylindrical member with a bottom and a central axis O in the vertical direction. The partition wall 101 is typically cylindrical in shape. The partition wall 101 houses the heating section 110. The partition wall 101 is arranged coaxially with the heating section 110. A combustion exhaust gas flow path 140 is provided between the heating section 110 and the partition wall 101. Heat from the burner of the heating section 110 and heat from the combustion exhaust gas are applied to the partition wall 101. An outlet pipe (not shown) is provided at the top of the partition wall 101. The combustion exhaust gas is discharged from the outlet pipe.

[0019] The inner cylinder 102 is a tubular member having a central axis O in the vertical direction. The inner cylinder 102 is typically cylindrical in shape. The inner cylinder 102 surrounds the outer periphery of the partition wall 101. The inner cylinder 102 is arranged coaxially with the partition wall 101. The inner cylinder 102 includes an upper portion and a lower portion. The diameter of the lower portion is larger than the diameter of the upper portion. A gap is provided between the inner cylinder 102 and the partition wall 101. The inner cylinder 102 is a metal member. A supply pipe 130 is connected to the inner cylinder 102. A raw material gas containing hydrocarbon and water are supplied to the supply pipe 130. The raw material gas and water are supplied to the evaporation section 111.

[0020] The evaporation section 111 is disposed inside the outer cylinder 103. The evaporation section 111 is provided on the upstream side of the space between the partition wall 101 and the inner cylinder 102. The upper side of the partition wall 101 is bent to have a convex structure that protrudes outward. This convex structure has a spiral structure. The spiral structure functions as a partition that helically divides the inner region of the upper part of the inner cylinder 102, thereby defining a space 171. The evaporation section 111 is composed of the upper part of the inner cylinder 102, the upper structure of the partition wall 101, and the space 171. In the space 171 of the evaporation section 111, the raw material gas and water flow, and the water evaporates into steam due to heat transferred from the partition wall 101. The evaporation section 111 guides the raw material gas and water to the reforming section 112 while heating them with heat from the heating section 110.

[0021] The reforming section 112 is disposed inside the outer cylinder 103. The reforming section 112 is provided downstream of the space between the partition wall 101 and the inner cylinder 102. The reforming section 112 is provided in the cylindrical space between the partition wall 101 and the inner cylinder 102. A space 172 is provided between the lower structure 162 of the partition wall 101 and the lower part of the inner cylinder 102. A reforming catalyst is filled in the space 172. The lower structure 162, the lower part of the inner cylinder 102, the space 172, and the reforming catalyst constitute the reforming section 112. The reforming section 112 is heated by heat transferred from the partition wall 101. The raw material gas and steam flowing out from the evaporation section 111 flow in the space 172 of the reforming section 112. The reforming section 112 generates a hydrogen-containing gas by a reforming reaction from a mixed gas of the raw material gas and steam heated in the evaporating section 111. The hydrogen-containing gas generated in the reforming section 112 flows toward the inner surface 103a of the bottom of the outer cylinder 103.

[0022] The outer cylinder 103 is a tubular member having a central axis O in the vertical direction. The outer cylinder 103 is typically cylindrical in shape. The outer cylinder 103 has an outer periphery and a bottom. The outer cylinder 103 is a container that houses various components of the hydrogen generation device 100. The outer cylinder 103 houses the heating section 110, the evaporation section 111, and the reforming section 112 inside. The outer cylinder 103 is arranged coaxially with the inner cylinder 102. The central axes O of the partition wall 101, the inner cylinder 102, and the outer cylinder 103 are aligned with one another. The outer cylinder 103 is a metal member. The outer cylinder 103 surrounds the inner cylinder 102. A return flow path 131 is provided between the lower portion of the outer cylinder 103 and the lower portion of the inner cylinder 102. The return flow path 131 redirects the flow of hydrogen-containing gas that flows downward from the reforming section 112 upward. The outer cylinder 103 is provided with a hydrogen gas exhaust pipe 132. The hydrogen-containing gas flowing out from the reforming section 112 is sprayed onto the inner surface 103a at the bottom of the outer cylinder 103. Thereafter, the hydrogen-containing gas flows upward through the return flow path 131. The hydrogen-containing gas passes through the return flow path 131 and is discharged from the hydrogen gas exhaust pipe 132 to the outside of the hydrogen generation device 100.

[0023] The heat insulating member 120 covers the outer cylinder 103. The heat insulating member 120 includes a cylindrical portion 120a that surrounds the side surface of the outer cylinder 103 and a bottom portion 120b that encases the bottom of the outer cylinder 103. The heat insulating member 120 is composed of, for example, a plurality of fumed silica heat insulating plates stacked vertically. The bottom portion 120b of the heat insulating member 120 is provided with a through hole 124 that communicates with the outer surface 103b of the bottom of the outer cylinder 103. The cross section perpendicular to the length direction of the through hole 124 is typically circular. The bottom portion 120b of the heat insulating member 120 is provided with a recess 125 that communicates with the through hole 124. The cross section perpendicular to the depth direction of the recess 125 is typically circular. The central axes O of the through hole 124 and the recess 125 are aligned. In this embodiment, the central axis O of the through-hole 124 and the recess 125 coincides with the central axis O of the partition wall 101, the inner cylinder 102, and the outer cylinder 103. The diameter of the through-hole 124 is smaller than the diameter of the upper portion of the recess 125.

[0024] A temperature sensor 121 for measuring the temperature of the reforming section 112 is disposed in the through-hole 124. An elastic body 122 is disposed in the recess 125. The recess 125 is covered by a flange 123. The temperature sensor 121 and the elastic body 122 are disposed so as to penetrate the bottom 120b of the heat insulating member 120. The longitudinal dimensions of the temperature sensor 121 and the elastic body 122 are determined by the thickness of the bottom 120b of the heat insulating member 120. The thickness of the bottom 120b of the heat insulating member 120 determines the distance between the flange 123 and the outer surface 103b of the bottom of the outer cylinder 103.

[0025] Figure 2 is a partial enlarged view of Figure 1. In Figure 2, temperature sensor 121 is arranged so that tip 121a is in contact with outer surface 103b of the bottom of outer cylinder 103. Elastic body 122 is arranged between temperature sensor 121 and flange 123. Elastic body 122 and flange 123 form absorbing section 128. Absorbing section 128 absorbs expansion and contraction of temperature sensor 121 so that tip 121a of temperature sensor 121 is maintained in contact with outer surface 103b of outer cylinder 103.

[0026] The absorbing portion 128 is disposed outside the through-hole 124. The absorbing portion 128 is disposed in the recess 125. The flange 123 is a part of the absorbing portion 128. A part of the absorbing portion 128 fixed to the heat insulating member 120 includes the flange 123 fixed to the surface of the heat insulating member 120 adjacent to the recess. The flange 123 closes the recess 125. The flange 123 is fixed to the heat insulating member 120 outside the recess 125 by a fixing member 123a.

[0027] The temperature sensor 121 is disposed between the elastic body 122 and the outer surface 103b of the outer cylinder 103. The central axis O of the outer cylinder 103, the temperature sensor 121, and the elastic body 122 coincides. The temperature sensor 121 includes a tip portion 121a, a rod-shaped main body portion 121b including the tip portion 121a, and a flange portion 121c fixed to the main body portion 121b. The main body portion 121b of the temperature sensor 121 is disposed in the through-hole 124. The main body portion 121b of the temperature sensor 121 reaches the outer surface 103b of the outer cylinder 103 through the through-hole 124 provided in the heat insulating member 120. The tip portion 121a of the temperature sensor 121 is disposed so as to contact the outer surface 103b of the outer cylinder 103. The tip portion 121a of the temperature sensor contacts the outer surface 103b of the outer cylinder 103 at a position overlapping with the central axis O. The flange portion 121c is disposed in the recess 125. In the recess 125, a gap is provided above the flange portion 121c of the temperature sensor 121 (on the outer cylinder 103 side in FIG. 2). However, this gap is not essential.

[0028] The temperature sensor 121 may include a thermocouple. A thermocouple is formed by joining two wires made of different metals. The thermocouple measures temperature using the thermoelectromotive force generated by the temperature at the junction. In this embodiment, a grounded sheathed thermocouple is used as the temperature sensor 121. The tip (junction) of this sheathed thermocouple is inserted into a sheath tube so as to contact the bottom of the sheath tube. Therefore, the tip of the sheath tube where the junction is located is the part that measures heat. The inside of the sheath tube is filled with a powdered inorganic insulator (e.g., MgO) to fill the gap with the thermocouple. The tip 121a of the temperature sensor 121 is the tip of the sheath tube. The main body 121b of the temperature sensor 121 is the sheath tube. The flange 121c closes the open end of the sheath tube. The flange 121c may be fixed to the elastic body 122. A through-hole (not shown) is formed in the flange portion 121c, and the thermocouple (indicated by the broken line in FIG. 2) is led out of the sheath tube through the through-hole in the flange portion 121c.

[0029] The elastic body 122 continuously applies a load to the temperature sensor 121 in a direction toward the outer surface 103 b of the bottom of the outer cylinder 103 .

[0030] The elastic body 122 is disposed between the flange portion 121c of the temperature sensor 121 and the flange 123. The elastic body 122 is disposed in the recess 125. One end of the elastic body 122 is fixed to the flange portion 121c of the temperature sensor 121. The other end of the elastic body 122 is fixed to the flange 123. This allows the temperature sensor 121 to be stably attached. The elastic body 122 is disposed while being compressed in a direction connecting the temperature sensor 121 and the flange 123. The elastic body 122 continuously applies a load to the flange portion 121c of the temperature sensor 121 in a direction toward the outer surface 103b of the bottom of the outer cylinder 103. In this embodiment, the elastic body 122 is a metal spring. The spring is typically a coil spring. The thermocouple of the temperature sensor 121 is inserted inside the coil spring.

[0031] A through-hole (not shown) is formed in the flange 123. A thermocouple (indicated by a broken line in FIG. 2) is led out through the through-hole in the flange 123. The thermocouple is housed and protected inside a protective tube 126. The thermocouple (indicated by a broken line in FIG. 2) is electrically connected to a control unit (not shown) by appropriate wiring. With this configuration, the temperature sensor 121 can detect the temperature of the reforming unit 112 through the bottom of the outer cylinder 103.

[0032] Data relating to the temperature of the reforming section 112 detected by the temperature sensor 121 is transmitted to the control section. The control section controls the hydrogen generator 100 based on the temperature of the reforming section 112 detected by the temperature sensor 121. Specifically, the control section controls the supply amounts of raw material gas, water, and air, the amount of combustion in the heating section 110, etc., based on the temperature of the reforming section 112, to generate a desired amount of hydrogen. Therefore, if the temperature of the reforming section 112 can be accurately detected, the performance of the hydrogen generator 100 can be improved.

[0033] [1-2. Operation] The operation of the hydrogen generator 100 configured as above will be described below.

[0034] The hydrogen generator 100 is started when a control signal for starting operation is output from a control unit (not shown). The heating unit 110 combusts combustible gas and discharges combustion exhaust gas (see FIG. 1). The combustion exhaust gas flows upward through a combustion exhaust gas flow path 140 and is discharged to the outside. When the heating unit 110 burns the combustible gas, the heat is transmitted to the reforming unit 112. This allows the reforming unit 112 to be heated to a desired temperature. The temperature of the reforming unit 112 is constantly detected by a temperature sensor 121. The detected temperature is sent to the control unit (not shown).

[0035] A raw material gas such as city gas and liquid water are supplied to evaporation section 111, and the water is vaporized by heat transmitted through partition wall 101, resulting in a mixed gas of the raw material gas and water vapor (see FIG. 1). The mixed gas in evaporation section 111 flows toward inner surface 103a at the bottom of outer cylinder 103.

[0036] Since the hydrogen generator 100 has a cylindrical container (outer cylinder 103 in FIG. 1), the mixed gas in the evaporator 111 flows not only in the axial direction but also in the rotational direction around the heating unit 110 as a concentric axis in FIG. 1. Therefore, the reformer 112 also has a roughly doughnut-like shape, and the mixed gas flows into the reformer 112 from all around.

[0037] The mixed gas of raw material gas and steam that flows into the reforming section 112 is heated to 600°C by the heat of the heating section 110, and is reformed by the reforming catalyst into a hydrogen-containing gas that also contains carbon monoxide (see FIG. 1). At this time, a reaction occurs in which hydrogen and carbon dioxide are produced from methane and water as shown in chemical formula (1), and a reaction occurs in which hydrogen and carbon monoxide are produced from methane and water as shown in chemical formula (2). CH4+ 2H2O → 4H2+ CO2···(1) CH4 + H2O → 3H2 + CO ···(2) However, 600°C is a typical temperature, and the temperature inside the reforming section 112 due to the reaction varies depending on the structure, material, and size of the reforming section 112. For example, it can range from 400°C to 650°C.

[0038] The hydrogen-containing gas flows out from the downstream end of the reforming section 112 and is sprayed onto the inner surface 103a at the bottom of the outer cylinder 103 (see FIG. 1). Thereafter, the hydrogen-containing gas flows into the return flow passage 131. The return flow passage 131 has a doughnut shape, and the hydrogen-containing gas flows axially upward along the entire circumference of the return flow passage 131. The hydrogen-containing gas passes through the return flow passage 131 and is discharged from the hydrogen gas exhaust pipe 132 to the outside of the hydrogen generation device 100.

[0039] 3 is a plan view of the hydrogen generation device 100, observed in a direction from the reforming section 112 toward the inner surface 103a at the bottom of the outer cylinder 103. In FIG. 3, the inner surface 103a includes an overlapping portion 180 that overlaps with the reforming section 112. The overlapping portion 180 is a donut-shaped region surrounded by a two-dot chain line. The high-temperature hydrogen-containing gas generated in the reforming section 112 is blown in a donut-shaped manner toward the inner surface 103a at the bottom of the outer cylinder 103.

[0040] Meanwhile, the temperature sensor 121 detects the temperature of the reforming section 112 through the bottom of the outer cylinder 103. A tip 121a (indicated by a dashed line in FIG. 3) of the temperature sensor 121 is in contact with the outer surface 103b of the bottom of the outer cylinder 103 at a position overlapping the central axis O (see FIG. 2). This allows the temperature sensor 121 to detect a representative temperature averaged over the entire circumferential direction. This makes it possible to suppress deviations in specific temperatures in the circumferential direction.

[0041] [1-3. Operation of the absorption unit] The temperature of the reforming section 112 is detected by the temperature sensor 121 via the bottom of the outer cylinder 103, but the hydrogen-containing gas sprayed toward the inner surface 103a of the bottom of the outer cylinder 103 is at a high temperature. Therefore, heat is transferred from the outer surface of the outer cylinder 103 to the tip 121a of the temperature sensor 121, and thermal changes can cause the temperature sensor 121 to expand and contract. The absorbing section 128 absorbs the expansion and contraction of the temperature sensor 121, thereby maintaining a state of contact between the tip 121a of the temperature sensor 121 and the outer surface 103b of the outer cylinder 103.

[0042] The following describes the operation of the absorbing section 128. Figures 4A to 4D are diagrams for explaining expansion and contraction of the temperature sensor 121 due to thermal changes. Note that for the sake of convenience, some components are shown in a simplified manner in Figures 4A to 4D.

[0043] FIG. 4A shows the state of the temperature sensor 121 and absorbing unit 128 immediately after assembly. The length of the main body 121b of the temperature sensor 121 is defined as L. The elastic body 122 of the absorbing unit 128 continuously applies a load to the flange 121c of the temperature sensor 121 in a direction toward the outer surface 103b of the bottom of the outer cylinder 103. In this embodiment, the direction in which the load of the elastic body 122 acts on the temperature sensor 121 is parallel to the central axis O of the outer cylinder 103. The elastic body 122 is compressed in the direction connecting the flange and the temperature sensor 121, so a repulsive force acts upward. This maintains contact between the tip 121a of the temperature sensor 121 and the outer surface 103b of the outer cylinder 103. A gap G is provided between the flange 121c of the temperature sensor 121 and the bottom surface 125p of the recess 125 of the heat insulating member 120.

[0044] FIG. 4B shows the state of the temperature sensor 121 and the absorption part 128 when a thermal change occurs after the hydrogen generation apparatus 100 starts operating. The temperature sensor 121 expands due to thermal expansion. As a result, the length of the main body 121b of the temperature sensor 121 changes to L+ΔL1. ΔL1 is the length expanded by the temperature sensor 121 due to thermal expansion. At this time, the elastic body 122 contracts by ΔL1 to absorb the expansion of the temperature sensor 121. This maintains contact between the tip 121a of the temperature sensor 121 and the outer surface 103b of the outer cylinder 103.

[0045] 4C shows the state of the temperature sensor 121 and the absorption part 128 when the operation of the hydrogen generation apparatus 100 is stopped. The temperature sensor 121 shrinks due to thermal contraction. As a result, the length of the main body part 121b of the temperature sensor 121 becomes L-ΔL2. ΔL2 is the length of the temperature sensor 121 that has shrunk due to thermal contraction.

[0046] At this time, as shown in Fig. 4D, elastic body 122 expands by ΔL2 to absorb the contraction of temperature sensor 121. Furthermore, in recess 125, gap G is provided between flange portion 121c of temperature sensor 121 and bottom surface 125p of recess 125, so temperature sensor 121 moves upward in conjunction with the movement of elastic body 122. This eliminates the gap between tip end 121a of temperature sensor 121 and outer surface 103b of outer cylinder 103, maintaining contact.

[0047] The absorbing section 128 absorbs expansion and contraction of the temperature sensor 121 due to thermal changes, thereby maintaining contact between the tip 121a of the temperature sensor 121 and the outer surface 103b of the outer cylinder 103. This makes it possible to prevent a gap from being generated between the tip of the temperature sensor 121 and the outer surface 103b of the outer cylinder 103. Therefore, this configuration is suitable for accurately detecting the temperature of the reforming section 112 in the hydrogen generator 100.

[0048] (Embodiment 2) Hereinafter, the second embodiment will be described with reference to Figures 5 and 6. The same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

[0049] [2-1.Configuration] FIG. 5 is a vertical cross-sectional view of the hydrogen generation device 100A of the second embodiment.

[0050] 5, the positions of the temperature sensor 121 and the elastic body 122 in the hydrogen generator 100A of the present embodiment are different from the positions of the temperature sensor 121 and the elastic body 122 in the first embodiment (FIG. 1). Except for this point, the hydrogen generator 100A of the present embodiment has the same configuration as the hydrogen generator 100 of the first embodiment.

[0051] In this embodiment, the central axes of the temperature sensor 121 and the elastic body 122 do not coincide with the central axis O of the outer cylinder 103. At a position facing the reforming section 112, the tip end 121a of the temperature sensor 121 contacts the outer surface 103b of the bottom of the outer cylinder 103. The tip end 121a of the temperature sensor 121 contacts the outer surface 103b of the bottom of the outer cylinder 103 at a horizontal position corresponding to the most downstream part of the reforming section 112.

[0052] FIG. 6 is a plan view of the hydrogen generator 100A when observed along the direction from the reforming section 112 toward the inner surface 103a of the bottom of the outer cylinder 103.

[0053] 6, the inner surface 103a of the bottom of the outer cylinder 103 includes an overlapping portion 180 that overlaps with the reforming section 112. The overlapping portion 180 is a donut-shaped region surrounded by a two-dot chain line. The high-temperature hydrogen-containing gas generated in the reforming section 112 is blown in a donut-shaped manner toward the inner surface 103a of the bottom of the outer cylinder 103.

[0054] Meanwhile, the temperature sensor 121 detects the temperature of the reforming section 112 through the bottom of the outer cylinder 103. A tip 121a (indicated by a broken line in FIG. 6) of the temperature sensor 121 is in contact with the outer surface 103b of the bottom of the outer cylinder 103 corresponding to the overlapping portion 180. This allows the temperature of the reforming section to be detected accurately.

[0055] (Other variations) Although the tip 121b of the temperature sensor 121 is configured to be in direct contact with the outer surface 103b of the outer cylinder 103, this is not limiting. For example, the tip 121b of the temperature sensor 121 may be configured to be indirectly in contact with the outer surface 103b of the outer cylinder 103 via another member. The other member may be a thermally conductive member.

[0056] The tip 121a of the temperature sensor 121 may be disposed on the outer surface 103b of the outer periphery of the outer cylinder 103. If the hydrogen-containing gas generated in the reforming section 112 is blown toward the inner surface 103a of the outer periphery of the outer cylinder 103, the temperature sensor 121 can detect the temperature of the reforming section 112 via the outer periphery of the outer cylinder 103.

[0057] Although the temperature sensor 121 is a grounded sheathed thermocouple, the type of sheathed thermocouple is not limited to this. An ungrounded sheathed thermocouple or an exposed sheathed thermocouple may also be used. Thermocouples have high heat resistance and can accurately measure the temperature of hydrogen-containing gas, which can reach 600°C or higher. Therefore, the temperature sensor 121 may be a thermocouple other than a sheathed thermocouple. In contrast, thermistors have limited heat resistance and are therefore not suitable for measuring the temperature of hydrogen-containing gas.

[0058] Although both ends of the elastic body 122 are fixed to the temperature sensor 121 (flange portion 121c) and the flange 123, this is not limiting. As long as the elastic body 122 is configured to be able to continuously apply a load to the temperature sensor 121 in a direction toward the outer surface 103b of the bottom of the outer cylinder 103, the both ends of the elastic body 122 do not have to be directly fixed to the temperature sensor 121 and the flange 123. The both ends of the elastic body 122 may be indirectly fixed to the temperature sensor 121 and the flange 123 via another member. Alternatively, the elastic body 122 may be arranged in a state where both ends of the elastic body 122 are sandwiched between the temperature sensor 121 and the flange 123 and compressed in a direction connecting the temperature sensor 121 and the flange 123.

[0059] The elastic body 122 may be a resin spring. By adjusting the thickness of the heat insulating member 120, even a member with low heat resistance may be used as the elastic body 122. Other materials such as rubber and elastomer may also be used.

[0060] The hydrogen generator of this embodiment is not limited to polymer electrolyte fuel cells (PEFCs) and can be applied to fuel cells equipped with a reforming unit, such as solid oxide fuel cells (SOFCs).

[0061] (Other embodiments) As described above, Embodiments 1 and 2 have been described as examples of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to these and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made. Furthermore, it is also possible to combine the components described in Embodiments 1 and 2 above to create new embodiments.

[0062] The above description of the embodiments discloses the following techniques.

[0063] (Technology 1) A container and a reforming unit disposed inside the vessel and generating a hydrogen-containing gas from a raw material gas and water; a temperature sensor disposed so that a tip thereof is in contact with the outer surface of the container; an absorbing portion disposed outside the container and absorbing expansion and contraction of the temperature sensor so that the tip of the temperature sensor is maintained in contact with the outer surface of the container; A hydrogen generating device comprising:

[0064] In this configuration, hydrogen-containing gas is generated in a reforming section disposed inside the container. The temperature of the reforming section is detected by a temperature sensor disposed so that its tip is in contact with the outer surface of the container. Because the hydrogen-containing gas is hot, heat is transferred from the outer surface of the container to the tip of the temperature sensor, which can cause the temperature sensor to expand and contract. The absorption section disposed outside the container absorbs the expansion and contraction of the temperature sensor due to thermal changes, maintaining contact between the tip of the temperature sensor and the outer surface of the container. This makes it possible to prevent a gap from occurring between the tip of the temperature sensor and the outer surface of the container. Therefore, with this configuration, the temperature of the reforming section can be accurately detected in the hydrogen generation device.

[0065] (Technology 2) The hydrogen generation device according to technique 1 further includes a heat insulating member covering the container, the temperature sensor including a rod-shaped main body including the tip, the main body of the temperature sensor reaching the outer surface of the container through a through-hole provided in the heat insulating member, and the absorption unit being disposed outside the through-hole. With this configuration, the temperature sensor can be stably fixed.

[0066] (Technology 3) The hydrogen generation device according to Technical Problem 2, wherein the heat insulating member includes a recess communicating with the through-hole, the absorption unit is disposed in the recess, and a portion of the absorption unit is fixed to the heat insulating member outside the recess. This configuration allows the absorption unit to be stably fixed. Furthermore, the heat insulating member makes it difficult for heat from a high-temperature portion (the outer surface of the container) to be transferred to the absorption unit. This makes it possible to suppress deterioration of the absorption unit due to temperature changes on the outer surface of the container.

[0067] (Technology 4) The hydrogen generation apparatus according to technique 3, wherein a part of the absorption unit fixed to the heat insulating member includes a flange fixed to a surface of the heat insulating member adjacent to the recess. With this configuration, the absorption unit can be stably fixed.

[0068] (Technology 5) The hydrogen generation device according to any one of Techniques 1 to 4, wherein the absorption unit includes an elastic body that continuously applies a load to the temperature sensor in a direction toward the outer surface of the container. This configuration can prevent a gap from being generated between the tip of the temperature sensor and the outer surface of the container.

[0069] (Technology 6) The hydrogen generation apparatus according to technique 5, wherein the temperature sensor includes a rod-shaped main body including the tip and a flange fixed to the main body, and the elastic body applies the load to the flange. This configuration can prevent a gap from being generated between the tip of the temperature sensor and the outer surface of the container.

[0070] (Technology 7) The hydrogen generation device according to any one of Techniques 1 to 6, wherein the absorber includes a resin spring. This configuration allows the absorber to have elasticity. Furthermore, the resin spring is less susceptible to deterioration than the temperature sensor, which is constantly exposed to high temperatures. Therefore, the resin spring can be used repeatedly when replacing the temperature sensor, thereby reducing maintenance costs.

[0071] (Technology 8) The hydrogen generation device according to any one of Techniques 1 to 6, wherein the absorption unit includes a metal spring. This configuration allows the absorber to have elasticity. Furthermore, metal springs are less susceptible to deterioration than temperature sensors, which are constantly exposed to high temperatures. Therefore, the metal springs can be reused when replacing the temperature sensors, thereby reducing maintenance costs. Furthermore, metal springs are less susceptible to performance degradation due to temperature changes than resin springs.

[0072] (Technology 9) The hydrogen generation device according to any one of Techniques 1 to 8, further comprising a heating unit disposed inside the container, the container including a cylindrical partition wall surrounding the heating unit, an inner cylinder surrounding the partition wall, and an outer cylinder surrounding the inner cylinder, a reforming unit located in the space between the partition wall and the inner cylinder, and the tip of the temperature sensor contacting the outer surface of the bottom of the outer cylinder, which is the outer surface of the container, at a position facing the reforming unit. High-temperature hydrogen-containing gas generated in the reforming unit is sprayed in a doughnut shape toward the inner surface of the bottom of the outer cylinder. By bringing the tip of the temperature sensor into contact with the outer surface of the bottom of the outer cylinder at a position facing the reforming unit, the temperature of the reforming unit can be accurately detected.

[0073] (Technology 10) The hydrogen generation device according to any one of the first to ninth embodiments further includes a heating unit disposed inside the container, the container including a cylindrical partition wall surrounding the heating unit, an inner cylinder surrounding the partition wall, and an outer cylinder surrounding the inner cylinder, the central axes of the partition wall, the inner cylinder, and the outer cylinder being aligned with one another, and the tip of the temperature sensor contacting the outer surface of the outer cylinder, which is the outer surface of the container, at a position overlapping the central axis. The high-temperature hydrogen-containing gas generated in the reforming unit is sprayed in a donut-like pattern toward the inner surface of the bottom of the outer cylinder. By contacting the tip of the temperature sensor with the outer surface of the bottom of the outer cylinder at a position overlapping the central axis of the outer cylinder, an average representative temperature in the entire circumferential direction can be obtained. This can suppress bias in a specific temperature in the circumferential direction. Furthermore, since the tip of the temperature sensor is in contact with the center of the bottom of the outer cylinder, assembly of the temperature sensor is easier than contacting it at a position corresponding to the reforming unit. [Industrial Applicability]

[0074] The technology of the present disclosure is useful for a hydrogen generator equipped with a reforming unit, and is also applicable to a fuel cell equipped with a reforming unit. [Explanation of symbols]

[0075] 100, 100A Hydrogen Generator 101 Bulkhead 102 Inner cylinder 103 Outer cylinder 103a Inner surface 103b Outer surface 110 Heating section 111 Evaporation section 112 Reforming section 120 Heat insulating material 121 Temperature Sensor 121a Tip 121b Main body 121c flange 122 Elastic Body 123 flange 124 Through Hole 125 recess 126 Protection tube 128 Absorption section 130 Supply pipe 131 Return flow path 132 Hydrogen gas exhaust pipe 140 Combustion exhaust gas flow path 171, 172 space 180 Overlapping part O center axis

Claims

1. A container and a reforming unit disposed inside the vessel and generating a hydrogen-containing gas from a raw material gas and water; a temperature sensor disposed so that a tip thereof is in contact with the outer surface of the container; an absorbing portion disposed outside the container and absorbing expansion and contraction of the temperature sensor so that the tip of the temperature sensor is maintained in contact with the outer surface of the container; A hydrogen generating device comprising:

2. Further provided is a heat insulating member covering the container, the temperature sensor includes a rod-shaped main body including the tip portion, the main body of the temperature sensor reaches the outer surface of the container through a through hole provided in the heat insulating member, The absorption portion is disposed outside the through hole. The hydrogen generation device according to claim 1 .

3. the heat insulating member includes a recess communicating with the through hole, The absorbing portion is disposed in the recess, a part of the absorption section fixed to the heat insulating member outside the recess; The hydrogen generation device according to claim 2 .

4. a portion of the absorption section fixed to the heat insulating member including a flange fixed to a surface of the heat insulating member adjacent to the recess; The hydrogen generator according to claim 3 .

5. the absorption section includes an elastic body that continuously applies a load to the temperature sensor in a direction toward the outer surface of the container. The hydrogen generation device according to claim 1 .

6. the temperature sensor includes a rod-shaped main body portion including the tip portion and a flange fixed to the main body portion, The elastic body applies the load to the flange. The hydrogen generation device according to claim 5 .

7. The absorbing portion includes a resin spring. The hydrogen generation device according to claim 1 .

8. The absorbing portion includes a metal spring. The hydrogen generation device according to claim 1 .

9. Further comprising a heating unit disposed inside the container, the container includes a cylindrical partition wall surrounding the heating unit, an inner cylinder surrounding the partition wall, and an outer cylinder surrounding the inner cylinder, a reforming section is located in a space between the partition wall and the inner cylinder, the tip of the temperature sensor is in contact with the outer surface of the outer cylinder, which is the outer surface of the container, at a position facing the reforming unit; The hydrogen generation device according to claim 1 .

10. Further comprising a heating unit disposed inside the container, the container includes a cylindrical partition wall surrounding the heating unit, an inner cylinder surrounding the partition wall, and an outer cylinder surrounding the inner cylinder, the partition wall, the inner cylinder, and the outer cylinder have central axes that coincide with each other; the tip of the temperature sensor is in contact with the outer surface of the outer cylinder, which is the outer surface of the container, at a position overlapping with the central axis; The hydrogen generation device according to claim 1 .

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