fuel cell device

Abstract

To provide a fuel cell device, excellent in safety and reliability, in which a pipe connecting a raw fuel supply source to an on-off valve hardly comes off in a fuel supply passage.SOLUTION: In a raw fuel passage 22 for supplying raw fuel to a reformer 12, a fuel cell device 100 has a first pipe 60 which connects an on-off valve 150 to a raw fuel joint 156. The first pipe 60 comprises: a first opening 611; a second opening 612; a linearly-shaped first straight passage 621 including the first opening 611; and a linearly-shaped second straight passage 622 including the second opening 612. A first central axis L1 which is a central axis of the first straight passage 621 and a second central axis L2 which is a central axis of the second straight passage 622 form an angle of 90 degrees. Thus, the first pipe 60 is fixed with its both ends stretched in directions shifted at 90 degrees so that it becomes possible to effectively prevent the pipe from coming off by itself due to vibration and so forth.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a fuel cell device. [Background technology]

[0002] Fuel cell devices are known that generate electricity using a hydrogen-containing fuel gas and an oxygen-containing gas (air) and supply the electricity to the outside. They are configured to include a fuel cell module that generates electricity and auxiliary equipment for operating the fuel cell module within a housing.

[0003] Such fuel cell devices include a reformer that steam-reforms raw fuel such as natural gas or LP gas to generate fuel gas to be supplied to the fuel cell module. A vaporizer is provided upstream of the reformer, which vaporizes water to generate steam, and the raw fuel and water are introduced into the vaporizer. The steam generated in the vaporizer is mixed with the raw fuel and introduced into a downstream reforming section, where fuel gas is generated in the reformer (see, for example, Patent Document 1).

[0004] In addition, the fuel supply device that supplies the raw fuel to the vaporizer is equipped with auxiliary equipment from the upstream side, such as a double solenoid valve that blocks the raw fuel gas supplied from the supply source, a pressure sensor that detects the pressure of the raw fuel gas, a flow sensor that detects the flow rate of the raw fuel gas, a gas pump that delivers the raw fuel gas, and a desulfurizer that removes sulfur contained in the raw fuel gas, and the raw fuel gas supply source and each of the auxiliary equipment are connected by gas supply pipes. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2018-49783 Summary of the Invention [Problem to be solved by the invention]

[0006] In a flow path through which raw fuel gas flows, such as in the fuel supply device described above, if the piping connecting the auxiliary devices becomes disconnected, gas leakage may occur, potentially leading to a dangerous situation such as a fire or explosion. In particular, if the piping upstream of the solenoid valve becomes disconnected within the device, the raw fuel gas cannot be stopped, further increasing the risk. Therefore, structures are employed to prevent the auxiliary devices from easily disconnecting from the piping. For example, quick fasteners and other fasteners are commonly used to connect the auxiliary devices to the piping. One example of this is the provision of metal fittings to prevent the quick fasteners from coming loose. However, the provision of such metal fittings increases the number of parts, which inevitably increases the assembly time and part costs.

[0007] The present invention is intended to solve the above-mentioned problems, and aims to provide a fuel cell device that is safe and reliable, in which the piping connecting the raw fuel supply source and the solenoid valve in the fuel supply flow path does not easily come off. [Means for solving the problem]

[0008] The present invention provides a fuel cell that generates electricity using a fuel gas and an oxygen-containing gas, a reformer that reforms a raw fuel to generate the fuel gas; a raw fuel flow path that supplies the raw fuel to the reformer; an on-off valve provided in the raw fuel flow path; a raw fuel joint for connecting an external fuel supply source to the raw fuel flow path; the raw fuel flow path has a first pipe connecting the on-off valve and the raw fuel joint, The first pipe includes a first opening at one end, a second opening at the other end, a first linear flow path that is linear and includes the first opening, and a second linear flow path that is linear and includes the second opening. In the fuel cell device, a first central axis that is the central axis of the first straight flow path and a second central axis that is the central axis of the second straight flow path form an angle of 90 degrees. [Effects of the Invention]

[0009] With the above-described configuration, the first pipe connecting the fuel supply source and the on-off valve can be effectively prevented from spontaneously coming off due to vibration, etc. This results in a fuel cell device with excellent safety and reliability. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a system configuration diagram of a fuel cell device according to an embodiment of the present invention. [Figure 2] 3 is a diagram showing a connection structure between a first solenoid valve and a raw fuel joint in the present embodiment. FIG. [Figure 3] FIG. 3 is a diagram showing a first pipe according to the present embodiment. [Figure 4] 10A and 10B are diagrams showing other examples of the first pipe of the present embodiment. [Figure 5] FIG. 10 is an explanatory diagram of how to determine the pipe length y of the first pipe. [Figure 6] FIG. 2 is an exploded view of the housing of the fuel cell device. [Figure 7] FIG. 2 is a diagram showing the structure of the right side panel. [Figure 8] FIG. 10 is a diagram showing the arrangement of a raw fuel coupling and a first electromagnetic valve relative to an exterior panel. DETAILED DESCRIPTION OF THE INVENTION

[0011] A preferred embodiment of the present invention will be briefly described below, showing the operation of the present invention.

[0012] The present invention provides a fuel cell device having a first pipe connecting an on-off valve and a raw fuel joint to a raw fuel flow path that supplies raw fuel to a reformer, the first pipe having a first opening at one end, a second opening at the other end, a first linear flow path that is linear and includes the first opening, and a second linear flow path that is linear and includes the second opening, and the first central axis that is the central axis of the first linear flow path and the second central axis that is the central axis of the second linear flow path form an angle of 90 degrees. As a result, the first pipe connecting the fuel supply source and the on-off valve is fixed by being stretched at both ends in directions that are 90 degrees apart, effectively preventing the pipe from becoming detached due to vibration or the like. This results in a fuel cell device that is excellent in safety and reliability.

[0013] Furthermore, the on-off valve and the raw fuel joint are disposed at positions equidistant from the intersection of the first central axis and the second central axis, which allows the first opening and the second opening of the first pipe to be connected to either the on-off valve or the raw fuel joint, eliminating the risk of incorrect assembly and allowing assembly without worrying about the orientation of the first pipe.

[0014] The first pipe is arranged in a line that divides the angle between the first central axis and the second central axis equally. name This means that the shape of the first pipe remains the same regardless of the direction in which it is connected, so interference with other components that make up the fuel cell device can be avoided without having to worry about the direction of the pipe.

[0015] In addition, the raw fuel joint is attached to the housing, and the on-off valve is indirectly connected to the housing via one or more members, which prevents the positional relationship between the on-off valve and the raw fuel joint from changing, making it more difficult for the first piping to become disconnected. [Example]

[0016] An embodiment of the present invention will now be described with reference to the drawings.

[0017] 1 is a system configuration diagram of a fuel cell device according to this embodiment. The fuel cell device 100 includes a fuel cell module 1, and a plurality of accessories for operating the fuel cell module 1, such as a first heat exchanger 2, a heat storage tank 3, a condensed water tank 4, a radiator 5, an air supply device 14, a fuel supply device 15, and a reforming water supply device 16, are housed in a housing 50. It is not necessary to house all of the above-mentioned devices within the housing 50; for example, the first heat exchanger 2 and the heat storage tank 3 may be provided outside the housing 50. It is also possible to omit some of the above-mentioned devices in a fuel cell device.

[0018] The fuel cell module 1 is constructed by housing, inside a box-shaped storage container 10, a fuel cell 11 that generates electricity using fuel gas and oxygen-containing gas, and a reformer 12 that generates fuel gas to be supplied to the fuel cell 11.

[0019] The configuration of the fuel cell 11 is not particularly limited, but may have, for example, a cell stack structure in which a plurality of fuel cell units are arranged. The fuel cell 11 having a cell stack structure is constructed, for example, by fixing the lower end of each fuel cell unit to a manifold using an insulating bonding material such as a glass sealant.

[0020] The reformer 12 steam reforms raw fuel gas such as natural gas or LP gas to generate fuel gas to be supplied to the fuel cell 11. The reformer 12 is connected to a fuel supply device 15 that supplies the raw fuel gas and a reforming water supply device 16 that supplies reforming water, and the raw fuel gas and the reforming water undergo a reforming reaction in the heated reformer 12 to generate fuel gas containing hydrogen.

[0021] The fuel cell 11 is supplied with fuel gas produced in the reformer 12 and air (oxygen-containing gas) introduced by the air supply device 14. As the fuel gas passes through the fuel cell, it reacts with the oxygen-containing gas to generate electricity. The fuel gas and oxygen-containing gas that are not used for power generation join together at the top of the fuel cell 11 and are burned. This combustion of the fuel gas generates high-temperature exhaust gas, which heats the reformer 12. The exhaust gas produced in this way within the fuel cell module 1 is supplied to the first heat exchanger 2.

[0022] The first heat exchanger 2 is connected to a heat storage tank 3, a heat medium pump P1, and a radiator 5 via piping, forming a first heat medium circulation line HC1. A heat medium is introduced into this first heat medium circulation line HC1, and in the first heat exchanger 2, heat exchange occurs between this heat medium and the exhaust gas, heating the heat medium. Water or the like can be used as the heat medium, and the heat storage tank 3 stores the heat medium whose temperature has been increased by heat exchange. The heat medium stored in the heat storage tank 3 is sent to the radiator 5 to be cooled, and then exchanges heat with the exhaust gas again in the first heat exchanger 2 before returning to the heat storage tank 3. As a result, high-temperature heat medium is stored in the heat storage tank 3 from the top, forming a temperature stratification.

[0023] In addition, a condensed water tank 4 is connected to the first heat exchanger 2 via a condensed water recovery path 20. When the exhaust gas generated in the fuel cell module 1 is cooled by heat exchange, the water vapor contained in the exhaust gas is separated into water and gas, and the separated water is recovered in the condensed water tank 4 through the condensed water recovery path 20. In the condensed water tank 4, the recovered water is purified by removing impurities through an ion exchanger (not shown) or the like. The purified water is supplied to the reformer 12 by the water supply device 16 and used as reforming water. Meanwhile, the gas from which the water has been removed passes through the exhaust path 21 and is then discharged to the outside of the housing 50.

[0024] The fuel supply device 15, which supplies raw fuel to the reformer 12, is provided with accessories such as a first solenoid valve 150, a pressure sensor 151, a desulfurizer 152, a gas flow meter 153, a fuel pump 154, and a second solenoid valve 155 on a raw fuel flow path 22 connected to a fuel supply source. A raw fuel joint 156 is attached to the side of the exterior case 50, and this raw fuel joint 156 connects the raw fuel flow path 22 to a fuel supply source external to the fuel cell device 100. The reforming water supply device 16, which supplies reforming water to the reformer 12, is provided with accessories such as a reforming water pump 160 on a reforming water flow path 23 connected to the condensed water tank 4. The air supply device 14, which supplies oxygen-containing gas to the fuel cell module 1, is provided with accessories such as an air filter 140, an air flow meter 1412, and a blower 142 on an oxygen-containing gas flow path 24. The accessories listed here are merely examples, and other accessories may be included.

[0025] Furthermore, the fuel cell device 100 is provided with a control device 30 that controls the operation of various devices, as well as a power supply adjustment unit (power conditioner) 40 that converts the DC power generated by the fuel cell module 1 into AC power and adjusts the amount of the converted electricity supplied to an external load.

[0026] The fuel cell device 100 may also include a second heat exchanger 6, a heat pump P2 that circulates the heat medium from the heat storage tank 3, and a second heat medium circulation line HC2 that includes piping connecting these. In the second heat medium circulation line HC2, tap water supplied from the outside via a supply flow path 25 is heated in the second heat exchanger 6 using the high-temperature heat medium stored in the heat storage tank 3. The heated water can be supplied to a reheating device such as an external water heater via a supply flow path 26. The fuel cell device 100 may be a so-called monogeneration system that does not supply hot water to the outside.

[0027] 2 is a diagram showing the connection structure between the first solenoid valve and the raw fuel joint. A first pipe 60 is provided between the first solenoid valve 150 and the raw fuel joint 156. The first solenoid valve 150 is configured by arranging two solenoid valves 150a and 150b in a casing as shown in FIG. 1, and by opening and closing these solenoid valves 150a and 150b, the raw fuel flow path 22 is switched between an open state and a closed state, thereby controlling the supply and cut-off of raw fuel to the reformer 12.

[0028] The first pipe 60 is one of the multiple pipes that make up the raw fuel flow path 22, and is made of copper pipe with high thermal conductivity, which has been subjected to bending processing. In this embodiment, the first pipe 60 is substantially L-shaped, with its upstream end connected to the raw fuel joint 156 and its downstream end connected to the first solenoid valve 150. A quick fastener 65 is attached and fixed to the connection point between the raw fuel joint 156 and the first solenoid valve 150.

[0029] 3 is a diagram illustrating a first pipe according to this embodiment. The first pipe 60 has a first opening 611 formed at one end and a second opening 612 formed at the other end. The flow path connecting the first opening 611 and the second opening 612 includes a first straight flow path 621 extending linearly and including the first opening 611 at one end, a second straight flow path 622 extending linearly and including the second opening 612 at the other end, and a curved flow path 623 connecting the first straight flow path 621 and the second straight flow path 622. The central axis of the first straight flow path 621 is defined as a first central axis L1, and the central axis of the second straight flow path 622 is defined as a second central axis L2. When these central axes are extended, the first central axis L1 and the second central axis L2 intersect at an angle of approximately 90 degrees.

[0030] Furthermore, if the intersection of the first central axis L1 and the second central axis L2 is defined as X, the length from the first opening 611 to X is equal to the length from the second opening 612 to X. In other words, the first solenoid valve 150 and the raw fuel coupling 156 are disposed at positions equidistant from the intersection X of the first central axis L1 and the second central axis L2.

[0031] Because the first central axis L1 and the second central axis L2 intersect at a 90-degree angle, tension forces act in 90-degree different directions between the first solenoid valve 150 and the raw fuel coupling 156, which are connected to both ends of the first piping 60. Because both ends of the piping are tensioned and fixed in 90-degree different directions, the first piping 60 cannot be pulled out unless it is intentionally pulled. Therefore, even if the quick fastener 65 comes off due to vibrations or the like associated with operation of the fuel cell device 100, the first piping 60 will not come off as well, so there is no risk of gas leakage and the device can be used safely. Furthermore, because metal fittings for fixing the quick fastener 65, as in the past, are no longer necessary, parts costs can be reduced.

[0032] Furthermore, because the first solenoid valve 150 and the raw fuel joint 156 are disposed at positions equidistant from the intersection X of the first central axis L1 and the second central axis L2, the first piping 60 can be connected in either direction. That is, the first opening 611 may be connected to either the first solenoid valve 150 or the raw fuel joint 156. This eliminates the risk of incorrect assembly, and allows assembly without having to worry about the orientation of the first piping 60, improving ease of assembly.

[0033] The shape of the first piping 60 can be changed by changing the lengths of the first straight flow path 621 and the second straight flow path 622 or by changing the shape of the flow path connecting the first straight flow path 621 and the second straight flow path 622. However, as long as the first central axis L1 and the second central axis L2 intersect at 90 degrees, the effect of making the first piping 60 less likely to come off can be obtained. Therefore, the first piping 60 is not limited to the L-shape shown in FIG. 3.

[0034] 4A and 4B are diagrams showing modified examples of the first pipe. In (A), the lengths of the first straight flow path 621 and the second straight flow path 622 are shorter than those in FIG. 3, and a straight flow path extending diagonally is provided between the first straight flow path 621 and the second straight flow path 622. In (B), a modified example of (A), a straight flow path extending diagonally between the first straight flow path 621 and the second straight flow path 622 is provided, and the lengths of the first straight flow path 621 and the second straight flow path 622 are different. In (C), an arc-shaped flow path is provided between the first straight flow path 621 and the second straight flow path 622. In (D), a stepped flow path is provided between the first straight flow path 621 and the second straight flow path 622. As described above, although the shape of the first pipe 60 is different, in all of (A) to (D), the first central axis L1 and the second central axis L2 intersect at an angle of 90 degrees.

[0035] In addition, when a bisector M is drawn to bisect the angle between the first central axis L1 and the second central axis L2, the first piping 60 has a line pair with the bisector M. name Since the angle between the first central axis L1 and the second central axis L2 is 90 degrees, the bisector M is a line that forms an angle of 45 degrees with the first central axis L1 (or the second central axis L2). In FIG. 3, the bisector M is shown by a dashed line, and the first pipe 60 is aligned with the bisector M. name In this way, the first pipe 60 is formed as a wire pair. name If the shape is made as shown in FIG. 1, the shape will be the same regardless of the direction in which the first pipe 60 is connected.

[0036] A large number of auxiliary devices are provided inside the fuel cell device 100, and in order to reduce the size, various auxiliary devices and the piping connecting them are densely arranged in a small space. Therefore, if the shape of the first piping 60 changes depending on the installation direction, it may interfere with other parts or piping, and the installation direction may end up being limited. In response to this, the first piping 60 is wire-coupled. name By adopting this shape, the shape does not change regardless of the orientation in which it is used, so that the first pipe 60 can be used without worrying about the orientation.

[0037] A method for setting the piping length of the first piping 60 will be described with reference to Fig. 5. In Fig. 5, three points A, B, and C are assigned to the first piping 60, and the length of AB (=BC) is defined as the piping length y of the first piping 60. Then, ∠ACB is represented by α, the angle at which the first piping 60 can be inclined with respect to the raw fuel joint 156 is represented by θ, and the length from the opening of the first solenoid valve 150 to the seal surface is represented by s. In this case, the maximum length of the piping length y of the first piping 60 can be calculated using the following formula. √2·y·sin(α―θ)=ys y=-s / (√2·sin(α―θ))-1

[0038] Next, the housing 50 of the fuel cell device 100 will be described.

[0039] FIG. 6 is an exploded view of the housing of the fuel cell device of this embodiment, and FIG. 7 is a diagram showing the structure of the right side panel of this embodiment. The housing 50 of the fuel cell device 100 has a rectangular parallelepiped shape and includes a bottom plate 51, a top panel 52, and multiple side panels 53 to 56. The side panels include a left side panel 53, a right side panel 54, a front panel 55, and a rear panel 56, and the bottom plate 51 and each of the panels 52 to 56 are formed by bending sheet metal members. Each of the panels 52 to 56 may be composed of a single member, or may be formed by combining multiple members in advance. Furthermore, the housing 50 of this embodiment is configured so that the side panels 53 to 56 can be attached to the bottom plate 51 without using a frame, but a configuration including a frame is also possible.

[0040] A maintenance surface for performing maintenance is set in advance on the fuel cell device 100. The top panel 52 and some of the side panels 53 to 56 are maintenance panels that are removed during maintenance.

[0041] The right side panel 54 is made up of an upper panel 541 and a lower panel 542. The upper panel 541 has an openable cover 541a, and removing this cover 541a allows the power switch and breaker switch of the fuel cell device 100 to be operated. During maintenance, the upper panel 541 can be removed alone, while the lower panel 542 remains attached. The panel that can be removed during maintenance is not limited to the above-mentioned upper panel 541; other panels can also be designed to be removable. Furthermore, pipes for fuel, water, etc. are connected to the lower panel 542 via joints. A raw fuel joint 156 to which the first pipe 60 is connected is also attached to the lower panel 542.

[0042] The lower panel 542 has a pipe connection plate 542a to which pipes and the like are connected, and holding frames 542b attached to both left and right ends of the pipe connection plate 542a.

[0043] 8 is a diagram showing the arrangement of the raw fuel coupling and the first solenoid valve relative to the exterior panel. The raw fuel coupling 156 is attached by penetrating the lower panel 542, which is part of the right side panel 54. A solenoid valve fixing bracket 70 is attached to the first solenoid valve 150, and this solenoid valve fixing bracket 70 is connected to a holding frame 542b. Because the holding frame 542b is connected to the lower panel 542 and the bottom plate 51, the first solenoid valve 150 is connected to the exterior panel that constitutes the housing 50 via the solenoid valve fixing bracket 70 and the holding frame 542b. In other words, because both the first solenoid valve 150 and the raw fuel coupling 156 are directly or indirectly connected to the exterior panel that constitutes the housing 50 of the fuel cell device 100, misalignment of the positional relationship between the first solenoid valve 150 and the raw fuel coupling 156 is prevented. This prevents unnecessary external force from being applied to the first pipe 60 arranged between the first solenoid valve 150 and the raw fuel joint 156, making it more difficult for the first pipe 60 to become detached.

[0044] The solenoid valve fixture 70 of this embodiment is configured with a first member 71 screwed to the first solenoid valve 150 and a second member 72 screwed to the first member 71, and the second member 72 is connected to the holding frame 542b. However, the configuration of the solenoid valve fixture 70 is not limited to that described above, and the solenoid valve fixture 70 may be attached to the lower panel 542 rather than the holding frame 542b. However, if the first solenoid valve 150 and the raw fuel joint 156 are connected to a maintenance panel, there is a risk that their positional relationship will be shifted when the panel is removed during maintenance. For this reason, it is preferable that the first solenoid valve 150 and the raw fuel joint 156 are connected to an exterior panel or frame that will not be removed during maintenance. [Explanation of symbols]

[0045] 11 Fuel Cell 12 Reformer 22 Raw fuel flow path 150 First solenoid valve (on-off valve) 156 Raw fuel joint 50 cabinets 60 First Pipe 611 First opening 612 Second opening 621 First Straight Channel 622 Second Straight Channel L1 First center axis L2 Second center axis

Claims

1. a fuel cell that generates electricity using a fuel gas and an oxygen-containing gas; a reformer that reforms a raw fuel to generate the fuel gas; a raw fuel flow path that supplies the raw fuel to the reformer; an on-off valve provided in the raw fuel flow path; a raw fuel joint for connecting an external fuel supply source to the raw fuel flow path; the raw fuel flow path has a first pipe connecting the on-off valve and the raw fuel joint, The first pipe includes a first opening at one end, a second opening at the other end, a first linear flow path that is linear and includes the first opening, and a second linear flow path that is linear and includes the second opening. A fuel cell device in which a first central axis that is the central axis of the first straight flow path and a second central axis that is the central axis of the second straight flow path form an angle of 90 degrees.

2. 2. The fuel cell device according to claim 1, wherein the on-off valve and the raw fuel joint are disposed at positions equidistant from an intersection of the first central axis and the second central axis.

3. 3. The fuel cell device according to claim 2, wherein the first pipe has a shape that is symmetrical with respect to a line that equally divides the angle between the first central axis and the second central axis.

4. The raw fuel coupling is attached to a housing; 4. The fuel cell device according to claim 1, wherein the on-off valve is indirectly connected to the housing via one or more members.

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