Hydrogen fuse and hydrogen detector

Abstract

To detect the presence of a hydrogen gas in an atmosphere without requiring such a special energy as electricity and cut off the conduction state of electricity.SOLUTION: The hydrogen fuse includes: an insulation case which is a hollow case; a heat generation unit arranged outside the insulation case, the heat generation unit including a normal-temperature catalyst for catalyst-burning a hydrogen gas at normal temperatures; a pair of lead terminals of which top ends are separately arranged in the insulation case; and a soluble alloy body hung between the lead terminals in the insulation case, the soluble alloy body making the lead terminals conductive with each other and cutting off the conduction between the lead terminals by dissolving by heat generation in the heat generation unit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a hydrogen fuse that detects hydrogen gas in the atmosphere and interrupts electrical continuity, and to a hydrogen detection device equipped with the hydrogen fuse. [Background technology]

[0002] From the viewpoint of carbon neutrality, various hydrogen consuming devices are being developed. At the same time, from the viewpoint of safety, it is also required to detect when hydrogen leaks into the atmosphere. Patent Document 1 discloses a hydrogen gas detection sensor that detects hydrogen gas by detecting the voltage generated by thermoelectric conversion of heat generated by a catalytic reaction between hydrogen gas and a catalyst. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-201100 Summary of the Invention [Problem to be solved by the invention]

[0004] In the technology described in Patent Document 1, since the catalyst is heated to a predetermined temperature, combustible gases other than hydrogen gas are also burned, so it is unclear whether the heat generated is due to the catalytic reaction of hydrogen gas. Furthermore, a power source is required to heat the catalyst.

[0005] An object of the present disclosure is to provide a hydrogen fuse and a hydrogen detection device that sense the presence of hydrogen gas in the atmosphere and interrupt electrical conduction without requiring any particular energy such as electricity. [Means for solving the problem]

[0006] A first aspect of the hydrogen fuse comprises a hollow insulating case, a heat generating portion disposed outside the insulating case and including a room temperature catalyst for catalytically combusting hydrogen gas at room temperature, a pair of lead terminals disposed at a distance from each other within the insulating case, and a fusible alloy body disposed between the pair of lead terminals within the insulating case, connecting the pair of lead terminals and melting due to heat generated in the heat generating portion to cut off electrical continuity between the pair of lead terminals.

[0007] In the hydrogen fuse of the first embodiment, when hydrogen gas is present in the atmosphere, a heat generating portion containing a room-temperature catalyst that catalytically combusts hydrogen gas at room temperature generates heat. This heat generation melts the fusible alloy body that spans the pair of lead terminals inside the insulating case, interrupting electrical continuity between the pair of lead terminals. This makes it possible to interrupt electrical continuity through the lead terminals without requiring any special energy such as electricity.

[0008] A hydrogen fuse according to a second aspect has a sealing portion that covers the opening of the insulating case and seals the pair of lead terminals and the fusible alloy body within the insulating case.

[0009] According to the hydrogen fuse of the second aspect, the pair of lead terminals and the fusible alloy element can be protected by being sealed in the insulating case by the sealing portion.

[0010] In a third aspect of the hydrogen fuse, the insulating case contains aluminum nitride (a material with high thermal conductivity).

[0011] According to the third aspect of the hydrogen fuse, since it contains aluminum nitride, a material with high thermal conductivity, heat is more easily transferred from the heat-generating portion to the fusible alloy body in the insulating case, thereby improving the thermal response of the fusible alloy body.

[0012] The hydrogen fuse of the fourth aspect has a heat transfer promoting portion that promotes heat conduction from the heat generating portion to the fusible alloy body.

[0013] According to the hydrogen fuse of the fourth aspect, the heat transfer promotion portion promotes heat conduction to the fusible alloy body, thereby improving the thermal response of the fusible alloy body.

[0014] The hydrogen detection device of the fifth aspect includes a hydrogen fuse according to the first aspect 1 or the second aspect, and an alarm unit that notifies of the detection of hydrogen gas when the electrical connection between the pair of lead terminals in the hydrogen fuse is interrupted.

[0015] In the hydrogen detection device of the fifth aspect, when hydrogen gas is present in the atmosphere, heat is generated, causing the fusible alloy body to melt and interrupting electrical continuity between the pair of lead terminals. This interruption of electrical continuity causes the notification unit to notify the detection of hydrogen gas. This makes it possible to know that hydrogen gas is present in the atmosphere without requiring any particular energy source such as electricity. [Effects of the Invention]

[0016] According to the present disclosure, it is possible to provide a hydrogen fuse and a hydrogen detection device that sense the presence of hydrogen gas in the atmosphere and interrupt electrical conduction without requiring any particular energy such as electricity. [Brief explanation of the drawings]

[0017] [Figure 1] 1A is a longitudinal cross-sectional view of a hydrogen fuse according to a first embodiment, and FIG. 1B is a cross-sectional view taken along line AA. [Figure 2] 1 is a vertical cross-sectional view of a hydrogen fuse according to a first embodiment in a conduction-interrupted state. [Figure 3] FIG. 2 is a schematic diagram showing an electric circuit in which a hydrogen fuse is provided. [Figure 4] FIG. 4 is a radial cross-sectional view of a hydrogen fuse according to a modified example of the first embodiment. [Figure 5] 1A is a longitudinal cross-sectional view of a hydrogen fuse according to a second embodiment, and FIG. 1B is a partially cutaway cross-sectional view. [Figure 6] FIG. 10 is a vertical cross-sectional view of the hydrogen fuse according to the second embodiment in a conduction-interrupted state. [Figure 7] 10A and 10B are schematic diagrams of a hydrogen detection device according to a second embodiment, in which (A) shows a state in which the relay switch is off, and (B) shows a state in which the relay switch is on. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, each embodiment of the present invention will be described with reference to the drawings. The size of each part and the ratio between each part in each drawing referred to below are expressed schematically and do not necessarily reflect the actual size of each part and the ratio between each part. Note that symbols commonly assigned in each drawing indicate the same object unless otherwise specified.

[0019] First Embodiment As shown in Figures 1(A) and 1(B), the hydrogen fuse 10 according to the first embodiment of the present invention comprises an insulating case 12, a pair of lead terminals 14A, 14B, a fusible alloy body 16, flux 18, a sealing material 20, and a heat generating portion 24.

[0020] The insulating case 12 is cylindrical and hollow. The insulating case 12 is made of an electrically insulating material. The insulating case 12 preferably contains a material with high thermal conductivity, such as fine ceramics, such as aluminum nitride or silicon carbide.

[0021] A pair of lead terminals 14A, 14B are formed at the tip of the lead wire 14, and are arranged in the insulating case 12 so that the tip surfaces face each other but are spaced apart. The lead wires 14 extending from each of the lead terminals 14A, 14B are arranged along the cylindrical axis of the insulating case 12 and extend outward from the opening of the insulating case 12.

[0022] The fusible alloy body 16 is disposed so as to bridge the pair of lead terminals 14A, 14B, and electrically connects the pair of lead terminals 14A, 14B. A fusible alloy body generally used as a material for thermal fuses can be used for the fusible alloy body 16, and a material with an appropriate composition is selected so that it melts at a predetermined temperature. Specific examples of such materials include alloys of metals such as tin and lead, and the melting temperature can be controlled by adjusting the composition ratio of these metals.

[0023] The flux 18 is provided so as to cover the entire circumference of the fusible alloy body 16 and the joints between the fusible alloy body 16 and the lead terminals 14A, 14B. The flux 18 is used to promote spheroidization of the fusible alloy body 16 when it melts, and is generally a rosin-based or water-soluble flux.

[0024] The sealing material 20 is provided so as to cover the openings at both ends of the insulating case 12, and seals the pair of lead terminals 14A, 14B, the fusible alloy body 16, and the flux 18 within the insulating case 12. The sealing material 20 may be made of resin.

[0025] The heat generating unit 24 is provided on the outside of the insulating case 12 so as to cover the outer peripheral surface, and is formed to include a room temperature catalyst that catalytically combusts hydrogen gas at room temperature. The room temperature catalyst generates heat through catalytic combustion when hydrogen gas is present in the atmosphere.

[0026] An example of such a room-temperature catalyst is a catalyst containing 0.2 mass % or more of platinum. Here, room temperature refers to a temperature at which no special heating or cooling is performed, specifically a temperature in the range of approximately 15 to 30°C. Catalytic combustion at room temperature refers to a case in which the combustion section is not heated by a heater or the like when the measurement gas is brought into contact with the catalyst.

[0027] The room-temperature catalyst is capable of burning hydrogen at room temperature, and examples of such catalysts include platinum catalysts supported on metal oxides, such as alumina-supported platinum catalysts (Pt-Al2O3). For example, it is known that when 1000 ppm of hydrogen is burned using a catalyst in which 0.2 mass% of platinum is supported on an alumina carrier (0.2% Pt-Al2O3 catalyst), the combustion initiation temperature is room temperature (Sadamori, Hiroki, "Special Feature on Special Combustion Technology: Current Status of Catalytic Combustion Technology, Focusing on Catalytic Combustion Burners," Journal of the Fuel Association, Vol. 58, No. 626, June 1979, pp. 422-423).

[0028] The heat generating portion 24 can be formed by a coating film, and one example of a method for forming the heat generating portion 24 is to apply a liquid catalyst, which is a mixture of a powdered catalyst that burns hydrogen at room temperature, such as an alumina-supported platinum catalyst, and distilled water, to the surface of the insulating case 12 and then dry it.

[0029] The hydrogen fuse 10 can be electrically incorporated into an electrical circuit 50 including an AC power source 52 and an electrical device 54, as shown in Figures 3 and 5. The electrical device 54 may be a device that consumes hydrogen or a device that is dangerous to use in the presence of hydrogen. When the hydrogen fuse 10 is conductive, power is supplied to the electrical circuit 50, and the electrical device 54 operates. On the other hand, when the hydrogen fuse 10 is non-conductive, the power supply to the electrical circuit 50 is stopped.

[0030] Next, the operation of the hydrogen fuse 10 of this embodiment will be described.

[0031] When hydrogen gas leaks or the like and enters the atmosphere in which the electric circuit 50 incorporating the hydrogen fuse 10 and the electric device 54 is installed, the room-temperature catalyst in the heat-generating portion 24 of the hydrogen fuse 10 burns the hydrogen, causing the heat-generating portion 24 to rise in temperature. When the ambient temperature of the fusible alloy body 16 rises and reaches its melting point, the fusible alloy body 16 melts and condenses around the lead terminals 14A, 14B, causing it to break apart, as shown in Figure 2. This causes the hydrogen fuse 10 to become non-conductive, and the power supply to the electric device 54 is stopped.

[0032] In this way, the hydrogen fuse 10 of this embodiment heats up due to the presence of hydrogen gas in the atmosphere without requiring any special energy such as electricity, and is therefore able to interrupt electrical conduction through the lead terminals 14A and 14B.

[0033] Furthermore, in the hydrogen fuse 10 of this embodiment, the pair of lead terminals 14A, 14B and the fusible alloy body 16 are sealed in the insulating case 12 by the sealing material 20, so that they can be protected from the environment.

[0034] In addition, in this embodiment, the constituent material of the insulating case 12 contains aluminum nitride, which is a material with high thermal conductivity, so that heat is more easily transferred from the heat-generating portion 24 to the fusible alloy body 16 inside the insulating case 12, thereby improving the thermal response of the fusible alloy body 16.

[0035] In this embodiment, the outer surface of the insulating case 12 is flat, but as shown in Fig. 4, recesses 25 extending along the cylindrical axis direction may be provided at multiple locations in the circumferential direction (four locations in Fig. 4), and the heat generating portion 24A may also be formed as a coating in the recesses 25. By providing the recesses 25 to form the heat generating portion 24 in this manner, the area of ​​the heat generating portions 24, 24A is increased and the distance between the heat generating portion 24A and the fusible alloy body 16 is also reduced compared to when the recesses 25 are not provided. As a result, the recesses 25 function as heat conducting portions that promote heat conduction from the heat generating portions 24, 24A to the fusible alloy body 16, and the thermal response of the hydrogen fuse 10 can be improved.

[0036] Second Embodiment A hydrogen fuse 30 according to a second embodiment of the present invention will be described with reference to the drawings. In this embodiment, detailed descriptions of the same parts as in the first embodiment will be omitted.

[0037] As shown in Figures 5(A) and 5(B), the hydrogen fuse 30 of this embodiment comprises an insulating case 32, a pair of lead terminals 34A, 34B, a fusible alloy body 36, flux 38, a sealing material 40, and a heat generating portion 44.

[0038] The insulating case 32 is hollow and rectangular, with one side open, and is made of an electrically insulating material, similar to the first embodiment.

[0039] A pair of lead terminals 34A, 34B are formed at the ends of the lead wires 34, and are inserted from the opening of the insulating case 32 along the opposing inner walls of the insulating case 32, and are arranged parallel to each other. The lead wires 34 extend outward from the opening of the insulating case 32.

[0040] The fusible alloy body 36 is disposed so as to bridge the pair of lead terminals 34A and 34B, and electrically connects the pair of lead terminals 34A and 34B. The material of the fusible alloy body 36 can be the same as that of the first embodiment.

[0041] The flux 38 is provided so as to cover the entire circumference of the fusible alloy body 36 and the joints between the fusible alloy body 36 and the lead terminals 34A, 34B. The flux 38 may be the same as that in the first embodiment.

[0042] The sealing material 40 is provided so as to cover the opening of the insulating case 32, and seals the pair of lead terminals 34A, 34B, the fusible alloy body 36, and the flux 38 inside the insulating case 32. The sealing material 40 may be made of resin, as in the first embodiment.

[0043] The heat generating portion 44 is formed on the outer surface of the insulating case 32 facing the opening. As in the first embodiment, the heat generating portion 44 is formed to include a room temperature catalyst that catalytically combusts hydrogen gas at room temperature. The heat generating portion 44 can be formed by a coating film in the same manner as in the first embodiment.

[0044] The hydrogen fuse 30 of this embodiment can be incorporated into an electric circuit and used in the same way as the hydrogen fuse 10 of the first embodiment. When hydrogen gas flows into the atmosphere, the room-temperature catalyst in the heat-generating portion 44 burns the hydrogen, causing the heat-generating portion 44 to heat up and the fusible alloy body 16 to melt, condensing around and breaking the lead terminals 34A and 34B as shown in Fig. 6. This causes the hydrogen fuse 30 to become non-conductive, and the power supply to the electric device is stopped.

[0045] In this way, the hydrogen fuse 30 of this embodiment can also interrupt electrical conduction by the presence of hydrogen gas in the atmosphere, without requiring any particular energy such as electricity.

[0046] <Third embodiment> In the first and second embodiments, examples were described in which the power supply to the electrical device 54 is stopped when the hydrogen fuses 10, 30 become non-conductive. In this embodiment, an example is described in which the hydrogen fuses 10, 30 are incorporated into and used in a hydrogen detection device 60 shown in Figures 7(A) and 7(B).

[0047] The hydrogen detection device 60 includes an electric circuit 50 incorporating a hydrogen fuse 10 (or hydrogen fuse 30), and an alarm circuit 66. The alarm circuit 66 has a battery 61 and an alarm unit 62, and is connected to the electric circuit 50 via a relay switch 64.

[0048] The relay switch 64 has a movable part 64A and an electromagnet part 64B, and the movable part 64A is connected to the alarm circuit 66. The electromagnet part 64B is connected to the electric circuit 50. When electricity is flowing through the electric circuit 50, the relay switch 64 is turned off as the movable part 64A is attracted to the electromagnet part 64B against the biasing force (see FIG. 7(A)). When electricity is not flowing through the electric circuit 50, the relay switch 64 is turned on as the biasing force of the movable part 64A is positioned to make the alarm circuit 66 conductive (see FIG. 7(B)).

[0049] The alarm unit 62 uses power supplied from the battery 61 to alert the user of a hydrogen leak. The alert can be generated by a warning sound, voice, lighting of a warning light, display on a display unit (not shown), transmission of warning information to a service provider, etc. Here, because power is supplied from the battery 61 only when an alert is issued, a small capacity is sufficient; for example, a button battery would suffice.

[0050] In the hydrogen detection device 60 of this embodiment, when the hydrogen fuse 10 is interrupted due to a temperature rise, the power supply to the electromagnet portion 64B is stopped, the movable portion 64A is moved by the biasing force to a position that makes the alarm circuit 66 conductive, and the relay switch 64 is turned on. This allows the alarm portion 62 to notify the user of a hydrogen leak. [Explanation of symbols]

[0051] 10, 30 Hydrogen fuse 12, 32 Insulation case 14A, 14B, 34A, 34B lead terminals 16, 36 Fusible alloy body 20, 40 Encapsulating material 24, 24A, 44 Heating part 25 Recessed portion (heat transfer promotion portion) 60 Hydrogen detector 62 Information Department

Claims

1. a hollow insulating case; a heat generating portion disposed outside the insulating case and including a room temperature catalyst for catalytically combusting hydrogen gas at room temperature; a pair of lead terminals spaced apart from each other within the insulating case; a fusible alloy body that is bridged between the pair of lead terminals in the insulating case, electrically connects the pair of lead terminals, and melts when heated by the heat generating portion to interrupt electrical connection between the pair of lead terminals; A hydrogen fuse equipped with

2. a sealing portion that covers the opening of the insulating case and seals the pair of lead terminals and the fusible alloy body in the insulating case; The hydrogen fuse of claim 1 .

3. The insulating case contains fine ceramics. The hydrogen fuse of claim 1 .

4. a heat transfer promoting portion that conducts heat from the heat generating portion to the fusible alloy body; The hydrogen fuse of claim 1 .

5. A hydrogen fuse according to any one of claims 1 to 4; a notification unit that notifies the detection of hydrogen gas when the conduction between the pair of lead terminals in the hydrogen fuse is interrupted; A hydrogen detection device comprising:

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