Leak detection device

Abstract

The problem to be solved by the present invention is to provide a leak detection device capable of suppressing an increase in working man-hours in a manufacturing process of a fuel cell stack, thereby improving energy efficiency. In order to solve the problem, a leak detection device (1, 61) is provided with: a pressing device (15) that presses stacked fuel cells in a state in which the fuel cells are housed in a fuel cell case (FC) in a state in which one end is closed and the other end is not closed by a lid; a supply device (61) that supplies gas to the fuel cell case (C) in a state in which the pressing by the pressing device (15) is equal to or greater than a predetermined pressure; and a detection device (61) that detects a leakage of gas from the fuel cell case (C) in a state in which the gas is supplied by the supply device (61).

Description

Technical Field

[0001] The invention relates to a leakage detection device. Background Art

[0002] Conventionally, there is known a leakage detection device that performs a gas leakage inspection after a plurality of stacked fuel cell units are housed in a fuel cell case during a fuel cell stack manufacturing process (see Patent Document 1).

[0003] [Prior Art Literature]

[0004] (Patent Document)

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2022-077045 Summary of the Invention

[0006] [Problems to be solved by the invention]

[0007] In the aforementioned leak detection device, after the fuel cell cells stacked in the fuel cell casing of the fuel cell stack are housed, the fuel cell stack is tightened with an arbitrary load using a tightening device that tightens the cover to the opening of the fuel cell casing, and then leak detection is performed. If a leak is detected by the leak detection device, the fuel cell stack must be disassembled while the cover is tightened to the fuel cell casing, and the fuel cell cells must be replaced, resulting in increased labor hours in the fuel cell stack manufacturing process.

[0008] An object of the present invention is to provide a leakage detection device that can suppress an increase in working man-hours in a fuel cell stack manufacturing process and thereby improve energy efficiency.

[0009] [Technical means to solve the problem]

[0010] To achieve the above-mentioned object, the present invention provides a leakage detection device (e.g., "casing holder 1, pressure detection and inspection device 61" described below) that detects leakage of a fuel cell casing (e.g., "fuel cell casing C" described below) that houses a plurality of stacked fuel cell cells (e.g., "fuel cell cells FC" described below), the leakage detection device comprising: a pressing device (e.g., "pressing device 15" described below) that presses the stacked fuel cell cells that are housed in the fuel cell casing with one end closed and the other end not closed by a cover; a supply device (e.g., "pressure detection and inspection device 61" described below) that supplies gas to the fuel cell casing when the pressure exerted by the pressing device is at or above a predetermined pressure; and a detection device (e.g., "pressure detection and inspection device 61" described below) that detects leakage of gas from the fuel cell casing when the gas is supplied by the supply device.

[0011] In the above invention, the leak detection device preferably includes an end fixture (e.g., "lower fixture 20" described below) connected to one end of the fuel cell casing and supplying gas through the fuel cell casing. Furthermore, the gas is preferably supplied via a gas flow path that is supplied during operation of the fuel cell. Furthermore, the leak detection device preferably includes another end fixture (e.g., "upper fixture 30" described below) having a sealing structure that seals the other end of the fuel cell casing to prevent leakage of the supplied gas from the fuel cell casing.

[0012] (Effects of the Invention)

[0013] According to the present invention, it is possible to provide a leakage detection device that can suppress an increase in working man-hours in a fuel cell stack manufacturing process and thereby achieve improved energy efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a diagram for explaining the leakage detection device according to this embodiment.

[0015] Figure 2 It is an upper perspective view illustrating the lower jig of the leakage detection device according to the present embodiment.

[0016] Figure 3 This is a bottom perspective view illustrating the lower jig of the leakage detection device according to the present embodiment.

[0017] Figure 4 It is an upper perspective view illustrating the upper jig of the leakage detection device according to the present embodiment.

[0018] Figure 5 It is a side view explaining the bolts attached to the upper clamp of the leakage detection device according to the present embodiment.

[0019] Figure 6 It is a diagram for explaining the process of leak detection by the leak detection device according to this embodiment.

[0020] Figure 7 This is a flowchart illustrating the process of leak detection by the leak detection device according to this embodiment. DETAILED DESCRIPTION

[0021] The following describes the embodiments of the present invention. Figure 1 As shown, the leakage detection device is a device for detecting gas leakage in the fuel cell case C after the fuel cell unit FC is housed in the fuel cell case C constituting the fuel cell stack and before the cover F is fastened to the fuel cell case C, and includes a case holding portion 1 and a pressure detection inspection device 61.

[0022] The housing holder 1 includes a bottom portion 11, a top plate 12, support columns 13, an upper support portion 14, a pressing device 15, a lower clamp 20 serving as one end fixture, and an upper clamp 30 serving as the other end fixture. Furthermore, one end portion of each of pipe members 62, 63, and 64 is connected to a pressure detection and inspection device 61.

[0023] The bottom portion 11 is the lowest portion of the housing holding portion 1 and supports the top plate 12, pillars 13, and other components that constitute the housing holding portion 1. The top plate 12 is located vertically above the bottom portion 11 and is supported by a plurality of pillars 13 extending upward from the bottom portion 11. The upper support portion 14 is supported by the plurality of pillars 13 so as to be movable vertically relative to the pillars 13 along the pillars 13.

[0024] The upper support portion 14 is provided with a pressing device 15. The pressing device 15 is electrically connected to the pressure detection and inspection device 61 via an electrical line 65 such as a wire or a wireless line. As will be described later, the pressure applied by the pressing device 15 to the stacked fuel cell units FC can be detected by the pressure detection and inspection device 61.

[0025] An upper clamp 30 is fixed to the lower end of the pressing device 15. A lower clamp 20 is provided at the portion of the bottom 11 vertically below the upper clamp 30. The bottom of the fuel cell casing C is placed on the upper surface of the lower clamp 20. The upper clamp 30 is configured to airtightly seal the opening of the upper end of the fuel cell casing C placed on the upper surface of the lower clamp 20. Specifically, as shown in FIG. Figure 5As shown, the upper clamp 30 is connected to the upper end of the fuel cell case C via bolts 36 with O-rings 362 mounted therearound. The opening of the upper end of the fuel cell case C forms a sealed structure in which the upper clamp 30 hermetically seals the opening.

[0026] like Figure 3 As shown, the lower clamp 20 has: a rectangular plate-shaped central base 21; a pair of tube support portions 22, which are respectively connected to a pair of short sides of the rectangular central base 21; and a loading portion 23, which is arranged on almost the entire upper surface of the central base 21 and loads the bottom of the fuel cell shell C.

[0027] The other ends of the pipe members 62, 63, and 64 are fixed to the pair of pipe supports 22 of the lower clamp 20, respectively. The pipe members 62, 63, and 64 are connected to the flow paths of hydrogen, air, and cooling water as a refrigerant supplied to the fuel cell stack FCS when the fuel cell stack FCS is in use (operating) (hereinafter referred to as "flow paths of the fuel cell stack FCS"). Figure 1 For ease of explanation, each of the tube members 62, 63, and 64 is shown as a single tube member, but a pair is provided on the supply side and the discharge side. The supply-side ends of the tube members 62, 63, and 64 are fixed to one of the pair of tube supports 22, while the discharge-side ends of the tube members 62, 63, and 64 are fixed to the other of the pair of tube supports 22.

[0028] Helium gas for gas leak detection can be supplied from the pressure detection and inspection device 61 to the pipe members 62, 63, and 64. Helium gas can flow through the flow path of the fuel cell stack FCS instead of these gases and the coolant.

[0029] A control device is provided inside the pressure detection and inspection device 61. The control device provided inside the pressure detection and inspection device 61 controls the value of the pressure applied to the stacked fuel cell units FC by the pressing device 15 via the line 65. In addition, the control device provided inside the pressure detection and inspection device 61 controls the supply and circulation of helium gas into the fuel cell housing C via the pipe member 62, the pipe member 63, the pipe member 64, and the lower clamp 20. The pressure detection and inspection device 61 constitutes a supply device for supplying helium gas. In addition, the pressure detection and inspection device 61 constitutes a leakage detection device that detects leakage of helium gas from the fuel cell housing C by detecting the pressure of the helium gas supplied from the fuel cell housing C while the helium gas is being supplied.

[0030] Next, refer to Figure 6 as well as Figure 7The process of leak detection performed by the above-mentioned leak detection device is described. In the leak detection process, first, Figure 7 In step S11, the fuel cell casing C, with the stacked fuel cell units FC housed therein and the opening at the upper end open, is placed on the upper surface of the lower jig 20. Next, the other ends of the tube members 62, 63, and 64 are each secured to the lower jig 20 and connected to the flow paths of the fuel cell stack FCS.

[0031] Next, the upper support portion 14 is slid relative to the support column 13 to move the upper clamp 30 downward, thereby sealing the opening at the upper end of the fuel cell casing C and sealing the fuel cell casing C and the upper clamp 30 to form an airtight seal so that the helium gas supplied from the pressure detection inspection device 61 will not leak.

[0032] Next, in Figure 7 In step S12, in addition, as Figure 6 As shown in the "arbitrary load" in FIG, the stacked fuel cell units FC are pressurized (pressed) by applying an arbitrary load to the stacked fuel cell units FC by the pressing device 15. Figure 6 As shown in "Pressure Detection" in FIG, when the pressing device 15 is pressing at a predetermined pressure or above, pressure detection is performed to detect the pressure of helium gas while helium gas is being supplied from the pressure detection and inspection device 61 to the fuel cell case C. The predetermined pressure is, for example, a pressure equivalent to the pressure applied to the stacked fuel cell cells FC in a manufactured fuel cell stack FCS.

[0033] If the pressure test result is normal and no leakage is detected (step S12: qualified (OK)), then Figure 7 In step S13, in addition, as Figure 6 As shown in "Fastening" in FIG, the upper clamp 30 is removed from the fuel cell case C, and the opening at the upper end of the fuel cell case C is sealed with the cover F to form an airtight seal between the fuel cell case C and the cover F. Then, the process proceeds to step S15.

[0034] If the result of the pressure test is that leakage is detected (step S12: unqualified (NG)), Figure 7 In step S14 , the fuel cells FC are pressed in with a higher load, or the stacking length of the stacked fuel cells FC is adjusted, and the process returns to step S12 .

[0035] exist Figure 7 In step S15, with the opening of the upper end of the fuel cell casing C sealed with the cover F, helium is supplied to the fuel cell casing C from the pressure detection and inspection device 61 again to perform pressure detection, and the result is confirmed to be normal. Figure 7In step S16, in the fuel cell stack FCS, the insulation between the insulating shell and the metal part is checked, and then Figure 7 In step S17, check whether the wiring harness is installed properly (C2C short circuit check). Figure 7 In step S18, the fuel cell stack FCS is taken out and the manufacturing process is completed.

[0036] The effects of the above-described embodiment are as follows.

[0037] In this embodiment, the leakage detection device includes: a pressing device 15 for pressing the stacked fuel cell monomers FC, wherein the fuel cell monomers FC are in a state of being housed in a fuel cell shell C in which the lower end serving as one end is closed and the upper end serving as the other end is not closed by a cover F; a pressure detection inspection device 61 as a supply device for supplying gas to the fuel cell shell C in a state in which the pressure applied by the pressing device 15 is above a specified pressure; and a pressure detection inspection device 61 as a leakage detection device for detecting leakage of helium from the fuel cell shell C in a state in which helium is supplied by the pressure detection inspection device 61.

[0038] This allows the pressure test (pressure inspection) to be checked before the cover F is fastened to the fuel cell case C. This significantly reduces the amount of reassembly work required in the event of a pressure inspection failure (NG) after the cover F is fastened to the fuel cell case C.

[0039] Furthermore, in this embodiment, the leak detection device includes a lower fixture 20 as one end fixture, which is connected to the lower end portion of the fuel cell case C, and is supplied with helium gas through the fuel cell case C. Thus, by supplying helium gas to the lower fixture 20, helium gas can be circulated through the fuel cell case C into the interior of the fuel cell case C. Therefore, there is no need to provide a separate structure for supplying and circulating helium gas into the interior of the fuel cell case C, and pressure detection can be easily performed.

[0040] In this embodiment, helium is supplied through the same flow paths as hydrogen, air, and refrigerant that are supplied during operation of the fuel cell stack (FCS). This allows for pressure detection in the flow paths used during actual operation of the fuel cell stack (FCS). Furthermore, since pressure detection uses helium atoms, which have a small diameter and are non-explosive, leak detection is possible with high accuracy and safety.

[0041] Furthermore, in this embodiment, the leakage detection device includes an upper clamp 30 as the other end clamp. The upper clamp 30 has a sealing structure that seals the opening at the upper end of the fuel cell casing C, which serves as the other end, to prevent the supplied helium gas from leaking from the fuel cell casing C. Thus, similar to the fuel cell stack FCS, pressure detection can be performed while the upper end is sealed by the sealing structure. Consequently, pressure detection can be performed with high accuracy.

[0042] In addition, the present invention is not limited to the above-described embodiment, and modifications, improvements, etc. within the scope that can achieve the object of the present invention are included in the present invention.

[0043] For example, the configurations of the pressing device, supply device, leakage detection device, and other components of the present invention are not limited to the pressing device 15 and pressure detection and inspection device 61 in this embodiment.

[0044] Reference numerals

[0045] 1: Housing holding part (leak detection device)

[0046] 15: Pressing device

[0047] 20: Lower side fixture (one end fixture)

[0048] 30: Upper side fixture (other end fixture)

[0049] 61: Pressure detection and inspection device (leak detection device, supply device, detection device)

[0050] C: Fuel cell housing

[0051] FC: fuel cell monomer

Claims

1. A leak detection device for detecting leakage in a fuel cell casing containing a plurality of stacked fuel cell units, the leak detection device comprising: a pressing device for pressing the stacked fuel cell units, the fuel cell units being housed in the fuel cell housing with one end closed and the other end not closed by a cover; a supply device for supplying gas to the fuel cell casing when the pressing device is pressed to a predetermined pressure or above; and The detection device detects leakage of gas from the fuel cell casing while the gas is being supplied by the supply device.

2. The leakage detection device according to claim 1, wherein: The leakage detection device includes an end fixture connected to one end of the fuel cell casing and supplied with gas through the fuel cell casing.

3. The leakage detection device according to claim 2, wherein: The gas is supplied through a gas flow path that is supplied when the fuel cell is in use.

4. The leakage detection device according to claim 1, wherein: The leakage detection device includes a second end fixture having a sealing structure that seals the second end side of the fuel cell case to prevent the supplied gas from leaking from the fuel cell case.

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