Stationary fuel cell system

Abstract

A stationary fuel cell system comprising: two power generation modules provided with a fuel cell stack, and an auxiliary equipment structure including auxiliary equipment that transfers gas to and from the fuel cell stack; a piping module provided with an intake pipe through which air supplied to the power generation module flows, and an exhaust pipe through which air exhausted from the power generation module flows; and an electrical equipment module provided with a main power line that is connected to a branch power line drawn out from the fuel cell stack and that sends power generated by the power generation module to an external power converter, wherein the two power generation modules are arranged overlapping vertically, the piping module and the main power line are placed between the two power generation modules arranged overlapping, the intake pipe and the exhaust pipe are arranged side by side, and the main power line is placed aligned with the intake pipe and the exhaust pipe at a position facing the exhaust pipe and sandwiching the intake pipe.

Description

Technical Field

[0001] The present invention relates to a stationary fuel cell system.

Background Art

[0002] JP2020-98749A discloses a fuel cell module in which one end of a bus bar connected to a fuel cell stack protrudes from a heat insulating material surrounding the fuel cell stack, and an electric wire connection part which is a connection part with an electric wire from a harness is provided at the other end.

[0003] The above bus bar is drawn out from the side surface of the fuel cell stack and extends in the horizontal direction. Further, in the above module, an exhaust gas discharge pipe protrudes in the same direction from the same surface as the surface of the heat insulating material from which the bus bar protrudes. That is, the bus bar and the exhaust gas discharge pipe are arranged in parallel. In this configuration, the bus bar and the electric wire may be heated to a high temperature by radiant heat or convective heat transfer from the exhaust gas discharge pipe, resulting in performance degradation and thermal deterioration.

[0004] Therefore, an object of the present invention is to provide a stationary fuel cell system capable of suppressing the temperature rise of the bus bar and the electric wire due to radiant heat or convective heat transfer from the exhaust gas discharge pipe.

[0005] According to one aspect of the present invention, a stationary fuel cell system is provided, comprising: an auxiliary equipment structure including an auxiliary device for exchanging gas with a fuel cell stack; two power generation modules each having a fuel cell stack connected to at least one of the vertical surfaces of the auxiliary equipment structure; a piping module having an intake pipe through which air supplied to the power generation modules flows and an exhaust pipe through which air discharged from the power generation modules flows; and an electrical module connected to a branch power line drawn from the fuel cell stack and having a main power line for sending the power generated by the power generation modules to an external power converter. In this system, the two power generation modules are arranged stacked vertically, the piping module and the main power line are arranged between the two stacked power generation modules, the intake pipe and the exhaust pipe are arranged side by side, and the main power line is arranged side by side with the intake pipe and the exhaust pipe at a position opposite the exhaust pipe with the intake pipe in between. [Brief explanation of the drawing]

[0006] [Figure 1] Figure 1 is a perspective view showing the schematic configuration of a stationary fuel cell system. [Figure 2] Figure 2 is a front view of a stationary fuel cell system. [Figure 3] Figure 3 is a rear view of a stationary fuel cell system. [Figure 4] Figure 4 is a left side view of a stationary fuel cell system. [Figure 5] Figure 5 shows an excerpt of the fuel system components of a stationary fuel cell system. [Figure 6] Figure 6 shows the pair of cross members and the power generation module as viewed from the rear before assembly. [Figure 7] Figure 7 is a front view of a power plant utilizing the fuel cell system shown in Figure 1. [Figure 8A] Figure 8A shows the piping route of the intake system. [Figure 8B] Figure 8B shows the piping route of the exhaust system. [Figure 8C] Figure 8C shows a power system circuit. [Modes for carrying out the invention]

[0007] Embodiments of the present invention will be described below with reference to the drawings.

[0008] Figure 1 is a perspective view showing the schematic configuration of a stationary fuel cell system (hereinafter also simply referred to as the fuel cell system) 1 according to an embodiment of the present invention. Figure 2 is a front view of the fuel cell system 1. Figure 3 is a rear view of the fuel cell system 1. Figure 4 is a left side view of the fuel cell system 1. Figure 5 is a diagram showing an excerpt of the fuel system components of the fuel cell system 1. In this embodiment, the height direction of the fuel cell system 1 is defined as the up-down direction, the flow path direction of the intake pipe 8 and exhaust pipe 9, etc., which will be described later, is defined as the left-right direction, and the direction perpendicular to the up-down and left-right directions is defined as the front-back direction. Furthermore, in the front-back direction, the side on which the connection parts with each pipe 13, 14 of the auxiliary equipment structure 7, which will be described later, are provided is defined as the front (front). The left-right direction is based on the front view.

[0009] The fuel cell system 1 according to this embodiment is intended for stationary use. The fuel cell used in the fuel cell system 1 is a solid oxide fuel cell.

[0010] The fuel cell system 1 comprises two power generation modules 2, one piping module 3, one power recovery module 4 as an electrical module, and a frame 5 that supports them.

[0011] The power generation module 2 comprises an auxiliary structure 7, a first fuel cell stack 6A arranged on one of the upper and lower surfaces of the auxiliary structure 7, and a second fuel cell stack 6B arranged on the other surface. The fuel cell stack 6 consists of multiple single cells stacked in the vertical direction. The vertical dimension of the first fuel cell stack 6A is larger than that of the second fuel cell stack 6B. In other words, the first fuel cell stack 6A has a greater number of stacked single cells than the second fuel cell stack 6B.

[0012] In addition, when there is no need to distinguish between the first fuel cell stack 6A and the second fuel cell stack 6B, they will be referred to as fuel cell stack 6. Furthermore, although this embodiment describes a configuration in which the fuel cell stacks 6 are arranged on both the upper and lower sides of the auxiliary structure 7, a configuration in which the fuel cell stacks 6 are arranged on only one side is also acceptable.

[0013] The auxiliary equipment structure 7 is a housing that includes auxiliary equipment (such as a heat exchanger and a combustor) that exchanges gas with the fuel cell stack 6.

[0014] Furthermore, the power generation module 2 includes a fuel injection unit 24 that injects fuel to be supplied to the fuel cell stack 6 of the power generation module 2. The fuel injection unit 24 in this embodiment has two fuel injection valves, but the number of fuel injection valves is not limited to this.

[0015] The piping module 3 includes an intake pipe 8 through which air supplied to the power generation module 2 flows, an exhaust pipe 9 through which air discharged from the power generation module 2 flows, a fuel pipe 11 through which fuel supplied to the power generation module 2 flows, and cooling water pipes 10 and 12 for the injection unit through which cooling water for cooling the fuel injection unit 24 flows. In the following description, the cooling water pipes 10 and 12 for the injection unit may be simply referred to as "cooling water pipes 10 and 12". Also, cooling water pipe 10 may be referred to as the inlet cooling water pipe 10, and cooling water pipe 12 as the outlet cooling water pipe 12.

[0016] The power recovery module 4 includes a power box 19 that houses equipment and wiring for recovering the power generated by the power generation module 2 and transmitting it to the power converter 43 (described later), as well as equipment and wiring for drawing power necessary for driving auxiliary equipment from external facilities. The power box 19 is made of an insulated metal component. Known methods can be used for the insulation treatment.

[0017] The frame 5 consists of multiple frame members, a cross member 20, and first and second stays 21 and 22, arranged to surround two power generation modules 2 and one piping module 3.

[0018] Inside the frame body 5, the two power generation modules 2 are arranged one above the other in the vertical direction, and a piping module 3 is arranged therebetween. Hereinafter, when it is necessary to distinguish between the upper and lower power generation modules 2, the upper one is referred to as the upper power generation module 2A, and the lower one is referred to as the lower power generation module 2B.

[0019] By arranging the two power generation modules 2 one above the other in the vertical direction, the area required for installing the fuel cell system 1 can be reduced compared to a configuration in which the two power generation modules 2 are installed on the same plane (hereinafter, this is also referred to as being placed flat). Further, in the case of being placed flat, pipes such as the intake pipe 8 and the exhaust pipe 9 are arranged between adjacent power generation modules 2, and pipes branched from there to each auxiliary structure 7 are installed. On the other hand, in the fuel cell system 1 of the present embodiment, since the piping module 3 is arranged between the power generation modules 2 arranged one above the other in the vertical direction, when viewed from above, the area occupied by the pipes is smaller than that in the case of being placed flat. That is, according to the fuel cell system 1 of the present embodiment, it is possible to further reduce the area required for installing the fuel cell system 1 including a plurality of power generation modules 2.

[0020] The frame body 5 includes, for example, an upper portion surrounding the upper power generation module 2A, a lower portion surrounding the lower power generation module 2B, and an intermediate portion surrounding the piping module 3. The upper portion includes at least 12 frame members assembled in a box shape so as to surround the upper power generation module 2A, a cross member 20 arranged so as to cross the left and right side surfaces defined by the frame members in the front-rear direction, and a first stay 22 and a second stay 21 arranged so as to cross the front and rear side surfaces (that is, the front and the back) defined by the frame members in the left-right direction. The lower portion has the same configuration as the upper portion. The intermediate portion includes at least four frame members that connect the upper portion and the lower portion with a predetermined interval in the vertical direction.

[0021] The fuel cell system 1 is equipped with power lines to supply power necessary for the operation of the fuel injection unit 24, the auxiliary equipment included in the auxiliary equipment structure 7, the valve bodies and actuators that drive each valve body in the intake branch pipe 13 and exhaust branch pipe 14 (described later) (hereinafter collectively referred to as "auxiliary equipment") from an externally installed power source. The fuel cell system 1 is also equipped with signal lines to send the necessary control signals from an externally installed control device to the auxiliary equipment. Hereinafter, these will be collectively referred to as "power and signal lines". The power and signal lines are routed along the frame members of the frame 5 from the power recovery module 4 to the connected auxiliary equipment. The power and signal lines can be divided into main wiring connected to the externally installed power source and control device, and branch wiring that branches off from the main wiring and connects to the auxiliary equipment of each fuel cell system 1.

[0022] The upper power generation module 2A has the first fuel cell stack 6A positioned above the auxiliary structure 7 and the second fuel cell stack 6B positioned below it. This state will also be referred to as the upright state. On the other hand, the lower power generation module 2B has the same structure as the upper power generation module 2A, but the first fuel cell stack 6A is positioned below the auxiliary structure 7 and the second fuel cell stack 6B is positioned above it. In other words, it is the upper power generation module 2A inverted vertically around an axis extending in the front-to-back direction. This state will also be referred to as the inverted state. Similarly, the part of the frame 5 surrounding the upper power generation module 2A and the part of the frame 5 surrounding the lower power generation module 2B have the same structure but inverted vertically. In this way, by using two power generation modules 2 with the same structure, one in the upright state and the other in the inverted state, costs can be reduced compared to using multiple types of power generation modules 2. Furthermore, by adopting the same structure for both the upper and lower sections, the same shape and dimensions can be used for the piping and wiring between the piping module 3 and the power generation module 2, which also reduces costs.

[0023] Also, the two power generation modules 2 are arranged at positions where the central axis Cm in the front-rear direction is offset to the rear side with respect to the central axis Cf in the front-rear direction of the frame body 5 (see FIG. 4). The power generation module 2 is fixedly supported by a pair of cross members 20 provided on the right and left side surfaces of the frame body 5 and a first stay 22 provided on the rear surface of the frame body 5. The cross member 20 connects a pair of frame members extending in the vertical direction among the frame members defining the left and right side surfaces of the frame body. The first stay 22 connects a pair of frame members defining the rear surface of the frame body 5. Note that the method of fixing the power generation module 2 to the frame body 5 will be described later.

[0024] Each pipe of the piping module 3 is arranged such that the direction of the flow path is in the left-right direction of the frame body 5. The intake pipe 8 and the exhaust pipe 9 are supported by the frame body 5 via stays or the like not shown. Also, the fuel pipe 11 and the cooling water pipes 10 and 12 are supported by brackets 25 provided on the frame body 5.

[0025] The piping module 3 is arranged between the upper power generation module 2A and the lower power generation module 2B as described above. More specifically, the intake pipe 8 is arranged at a position overlapping the fuel cell stack 6 in a top view, and the exhaust pipe 9 is arranged at a position not overlapping the fuel cell stack 6 in a top view. By arranging the exhaust pipe 9 through which high-temperature exhaust flows in this way, the heat emitted from the exhaust pipe 9 can easily escape upward, so that the temperature rise of electrical components such as the fuel injection unit 24 can be suppressed.

[0026] Flange portions are provided at both left and right ends of the intake pipe 8 and the exhaust pipe 9. And when connecting a plurality of fuel cell systems 1 in the left-right direction as described later, these flange portions are fastened by bolts or the like.

[0027] The exhaust pipe 9 is a cylindrical single-pipe member except for the flanges at both ends. In contrast, the intake pipe 8 has a larger flow path cross-sectional area in the portion sandwiched between the flanges at both ends compared to the area of ​​the openings provided in the flanges. Furthermore, the flow path cross-sectional area in the portion sandwiched between the flanges at both ends of the intake pipe 8 is larger than the flow path cross-sectional area in the portion sandwiched between the flanges at both ends of the exhaust pipe 9. In other words, the intake pipe 8 has a larger flow path volume than the exhaust pipe 9. In this embodiment, the intake pipe 8 is a rectangular parallelepiped with circular openings on its left and right sides, but it is not limited to this, and any shape that satisfies the above-mentioned conditions is acceptable.

[0028] The fuel pipe 11 and the cooling water pipes 10 and 12 are fitted with ribs (not shown) at both ends. When multiple fuel cell systems 1 are connected in the left-right direction, the fuel pipes 11 and cooling water pipes 10 and 12 of adjacent fuel cell systems 1 are connected to each other via rubber pipes or the like (not shown).

[0029] The intake pipe 8 and the power generation module 2 are connected via an intake branch pipe 13. More specifically, the intake branch pipe 13, which branches off from the intake pipe 8, is connected to an intake port 7A provided in the auxiliary equipment structure 7.

[0030] The exhaust pipe 9 and the power generation module 2 are connected via an exhaust branch pipe 14. More specifically, the exhaust branch pipe 14, which branches off from the exhaust pipe 9, is connected to an exhaust port 7B provided on the auxiliary equipment structure 7. The exhaust gas discharged from the power generation module 2 becomes hot, and the connection point between the auxiliary equipment structure 7 and the exhaust branch pipe 14 also becomes hot, so the exhaust branch pipe is made of metal. In addition, since the temperature of the air flowing inside the intake branch pipe 13 and the temperature of the connection point between the auxiliary equipment structure 7 and the intake branch pipe 13 are lower than that of the exhaust branch pipe 14, rubber piping can be used in parts where heat is not easily transferred from the high-temperature power generation module 2, exhaust branch pipe 14, and exhaust pipe 9.

[0031] As described above, the upper power generation module 2A is in an upright position, and the lower power generation module 2B is in an inverted position, with the piping module 3 positioned between the two power generation modules 2. As a result, in both power generation modules 2, the second fuel cell stack 6B, which has a shorter vertical dimension than the first fuel cell stack 6A, is positioned closer to the piping module 3. In other words, the distance from the piping module 3 to each auxiliary equipment structure 7 is shorter compared to the case where the upper power generation module 2A is in an inverted position and the lower power generation module 2B is in an upright position.

[0032] The intake port 7A and exhaust port 7B are located on the front side of the auxiliary structure 7 when viewed from above. Also, as described above, the power generation module 2 is positioned offset to the rear side relative to the frame 5. Therefore, a distance is secured between the intake port 7A and exhaust port 7B and the frame 5, providing ample space for routing the intake branch pipe 13 and exhaust branch pipe 14. In this embodiment, the exhaust branch pipe 14 is located on the underside of the portion of the auxiliary structure 7 that protrudes to the front side relative to the fuel cell stack 6, and is connected from below; this is also included in "located on the front side of the auxiliary structure 7 when viewed from above." Alternatively, the exhaust port 7B may open in the forward direction, similar to the intake port 7A, and the exhaust branch pipe 14 may be connected from the front.

[0033] Furthermore, if either the air intake port 7A or the exhaust port 7B is located on the rear side of the auxiliary equipment structure 7 when viewed from above, the amount by which the power generation module 2 can be offset to the rear side is limited due to the presence of piping connected to it. As a result, dead space is created on both the front and rear sides. On the other hand, in the fuel cell system 1 of this embodiment, the air intake port 7A and the exhaust port 7B are concentrated on the front side, so the rear side of the power generation module 2 can be brought closer to the rear side of the frame 5. In other words, according to this embodiment, the dead space (IS in Figure 4) that occurs between the rear side of the frame 5 and the rear side of the power generation module 2 can be made smaller.

[0034] Furthermore, in the upper power generation module 2A, the intake port 7A is located on the left side and the exhaust port 7B is located on the right side when viewed from the front. On the other hand, in the lower power generation module 2B, the intake port 7A is located on the right side and the exhaust port 7B is located on the left side when viewed from the front. In other words, the arrangement of the intake port 7A and exhaust port 7B is reversed between the upper power generation module 2A and the lower power generation module 2B. This allows the positions of the intake pipe 8's connection point to the intake branch pipe 13 for the upper power generation module 2A and the connection point to the intake branch pipe 13 for the lower power generation module 2B to be shifted laterally. The intake branch pipe 13 has ancillary equipment such as a valve body and an actuator that drives the valve body (neither of which are shown), but by shifting the positions of the two connection points laterally in this way, the positions of the ancillary equipment can be distributed, and there is more flexibility in the routing of the two intake branch pipes 13. Furthermore, if the two connection points are located close together, problems may arise such as difficulty in air flowing to one of the intake branch pipes 13. However, as described above, this problem can be resolved by shifting the positions of the two connection points to the left and right. The same applies to the connection points of the exhaust pipe 9 to the two exhaust branch pipes 14.

[0035] In this embodiment, since the same power generation module 2 is used in both an upright and inverted state, it is natural that the arrangement of the air intake port 7A and exhaust port 7B is reversed as described above. However, even if two power generation modules 2 with different structures are used, the arrangement of the air intake port 7A and exhaust port 7B is reversed between the upper power generation module 2A and the lower power generation module 2B in order to resolve the above-mentioned problem.

[0036] Incidentally, when using the fuel cell system 1 in a power plant or the like, maintenance and inspection work is required, such as checking for leaks from each pipe and replacing consumables or faulty parts. In this embodiment of the fuel cell system 1, the power generation module 2 is positioned offset to the rear side relative to the frame 5, and the air intake ports 7A and exhaust ports 7B of the upper and lower power generation modules 2 are all located on the front side. Therefore, ancillary equipment such as shut-off valves, which will be described later, included in the piping module 3 can also be concentrated on the front side. As a result, with this embodiment of the fuel cell system 1, the amount of movement required by workers during maintenance and inspection work is reduced, and work efficiency can be improved.

[0037] Furthermore, during maintenance and inspection work, if the work area is low, workers will have to bend down or, in some cases, lie down. Conversely, if the work area is high, workers will have to stretch or stand on a step stool. In either case, it will worsen work efficiency. However, in the fuel cell system 1 of this embodiment, the upper power generation module 2A is in an upright position, and the lower power generation module 2B is in an inverted position, with the piping module 3 positioned between the two power generation modules 2. As a result, the positions of the auxiliary equipment structures 7 of the upper and lower power generation modules 2 are centered in the vertical direction of the fuel cell system 1, thus suppressing deterioration of work efficiency.

[0038] Furthermore, the inventors' investigation revealed that if the height of the work area from the installation surface is within the range of approximately 400mm-1500mm, the deterioration of workability can be suppressed. Therefore, although the dimensions of the power generation module 2 and the frame 5 can be set arbitrarily, from the viewpoint of the above-mentioned workability, the dimensions of the power generation module 2 and the frame 5 are set so that the height of the intake port 7A and exhaust port 7B of the upper and lower power generation modules 2 from the installation surface is within the range of 400mm-1500mm. It is also desirable that the connection between the fuel supply pipe 26 and the auxiliary equipment structure 7, which will be described later, be within this range.

[0039] The fuel injection unit 24 is fixedly supported by a second stay 21 provided on the front of the frame 5. Fuel is supplied from the fuel piping 11 to the fuel injection unit 24 via a fuel branch pipe 15, from the fuel injection unit 24 to the auxiliary equipment structure 7 via a fuel supply pipe 26, and from there to the power generation module 2. The connection between the fuel supply pipe 26 and the auxiliary equipment structure 7 is located on the front side of the auxiliary equipment structure 7 when viewed from above, similar to the intake port 7A and the exhaust port 7B. The fuel injection unit 24 also includes a coolant gallery 27 surrounding the injection part of the fuel injector. The coolant gallery 27 and the inlet coolant piping 10 are connected by a first coolant branch pipe 17, and the coolant gallery 27 and the outlet coolant piping 12 are connected by a second coolant branch pipe 16. In other words, the coolant is supplied from the inlet coolant pipe 10 to the coolant gallery 27 via the first coolant branch pipe 17, where it cools the fuel injection valve, and then flows into the outlet coolant pipe 12 via the second coolant branch pipe 16.

[0040] The inlet coolant pipe 10 is located on the non-insertion side relative to the fuel pipe 11, while the outlet coolant pipe 12 is located on the insertion side relative to the fuel pipe 11. In other words, the inlet coolant pipe 10 is located at the position furthest from the exhaust pipe 9, the outlet coolant pipe 12 is located at the position closest to the exhaust pipe 9, and the fuel pipe 11 is located between the inlet coolant pipe 10 and the outlet coolant pipe 12. The reason for this arrangement is as follows.

[0041] As mentioned above, the coolant flowing through the coolant pipes 10 and 12 is for cooling the fuel injection unit 24. Therefore, it is desirable that the inlet coolant pipe 10, through which the coolant flows before being used to cool the fuel injection unit 24, receive less heat from the exhaust pipe 9 through which the high-temperature exhaust gas flows. On the other hand, the coolant used to cool the fuel injection unit 24 is then cooled by a radiator (not shown), so the outlet coolant pipe 12 has a larger tolerance for heat transfer from the exhaust pipe 9 compared to the inlet coolant pipe 10. Also, from the viewpoint of reactivity in the fuel cell stack 6, it is desirable for the fuel to evaporate easily (i.e., at a higher temperature), but it is undesirable for the fuel to become so hot that bubbles are generated in the fuel pipe 11. Therefore, the inlet coolant pipe 10, through which we want to suppress heat transfer from the exhaust pipe 9, is positioned furthest from the exhaust pipe 9, the outlet coolant pipe 12, through which the heat from the exhaust pipe 9 has less negative impact, is positioned closest to the exhaust pipe 9, and the fuel pipe 11, through which it is desirable for the temperature to rise to a temperature at which fuel is easily evaporated after injection, is positioned between these two.

[0042] The power box 19 is located on the rear of the frame 5, between the upper and lower power generation modules 2. The power generation modules 2 and the power box 19 are electrically connected via a busbar 18, which serves as a branch power line. The busbar 18 is taken out from the surface opposite to the surface in contact with the auxiliary structure 7 of the fuel cell stack 6 (i.e., the top and bottom surfaces), extends in a direction different from the direction of the exhaust pipe 9, and is connected to the power box 19 through a wiring passage 23 provided along the frame member of the frame 5. Here, "extending in a direction different from the direction of the exhaust pipe 9" means not approaching the exhaust pipe 9. The power box 19 houses the main power line 53, which is connected to an externally installed power converter 43, and the busbar 18 is connected to this main power line 53. The wiring passage 23 is also made of insulated metal material, similar to the power box 19. This reduces the frequency with which live parts such as the busbar 18 and electrical wires come into contact with the frame member when the unit is disassembled for maintenance and inspection work.

[0043] When two power generation modules 2 are laid flat, it is necessary to provide a separate space for the power box 19 from the installation space for the power generation modules 2. However, with the configuration of this embodiment, this is no longer necessary. In other words, the area required for the installation of the fuel cell system 1 can be reduced.

[0044] Next, with reference to Figure 6, the method for attaching the power generation module 2 to the frame 5 will be explained.

[0045] Figure 6 shows the pair of cross members 20 and the power generation module 2 as seen from the rear before assembly. Note that at this stage, the first stay 22 is not attached to the frame 5.

[0046] On the opposing surfaces of the pair of cross members 20, guide grooves 33 are provided that extend in the front-rear direction (horizontal direction), with at least the rear end being an open end. The auxiliary structure 7 of the power generation module 2 is provided with a first slide portion 31 and a second slide portion 32, which have shapes corresponding to the guide grooves 33. In Figure 6, the slide member 30, which includes the second slide portion 32, is manufactured separately from the auxiliary structure 7 and attached to the auxiliary structure 7, but the second slide portion 32 may also be formed integrally with the housing of the auxiliary structure 7.

[0047] Then, with the back of the frame 5 as the insertion surface and the front as the non-insertion surface, the power generation module 2 is moved from the insertion surface along the guide groove 33 by aligning the first slide portion 31 and the second slide portion 32 with the guide groove 33, thereby inserting the power generation module 2 into the inside of the frame 5. After insertion, the power generation module 2 and the frame 5 are rigidly connected using the first stay 22. This fixes the power generation module 2 to the frame 5. At this time, if the guide groove 33 is provided from one end to the other of the cross member 20, it would be necessary to insert the power generation module 2 into the frame 5 while checking its position to position the power generation module 2. However, in this embodiment, the position of the front end of the guide groove 33 is aligned with the position of the first slide portion 31 when the power generation module 2 is properly positioned. In other words, the positioning of the power generation module 2 is completed when the first slide portion 31 is inserted until it contacts the front end of the guide groove 33. This makes positioning easier. Furthermore, the insertion surface is on the rear side, the connection points between the auxiliary structure 7 and each pipe are on the front side of the auxiliary structure 7, and each pipe is routed to avoid interference with the trajectory when the auxiliary structure 7 slides. Therefore, the power generation module 2 can be removed from the frame 5 by disconnecting the connections to each pipe. In other words, there is no need to remove each pipe from the frame 5 when replacing the power generation module 2, etc.

[0048] Furthermore, when the power generation module 2 is fixed to the frame 5 as described above, the auxiliary structure 7 of the power generation module 2 also functions as a structural member connecting the pair of cross members 20 provided on the left and right sides of the frame 5. The upper part of the frame 5 has its surface rigidity strengthened by the pair of cross members 20 on each of the left and right sides, by the second stay 21 on the front, and by the second stay 21 on the back. However, the auxiliary structure 7 functions as a structural member that crosses each of the left and right sides, thereby improving the rigidity of the entire upper part. The same applies to the lower part. This helps to suppress deformation and collapse due to external forces such as earthquakes.

[0049] Next, a power plant utilizing fuel cell system 1 will be described with reference to Figure 7.

[0050] Figure 7 is a front view of a power plant utilizing fuel cell system 1.

[0051] As shown in the figure, multiple fuel cell systems 1 are arranged adjacent to each other in the left-right direction, and their respective frames 5 are rigidly connected to each other by bolts or the like. As a result, the pair of rigidly connected frame members function as reinforcing members for each other, suppressing deformation of the frame 5. The intake pipes 8, exhaust pipes 9, fuel piping 11, and cooling water piping 10, 12 of each fuel cell system 1 are also connected. The intake pipes 8 of adjacent fuel cell systems 1 are connected via connecting pipes. The same applies to the exhaust pipes 9. The connecting pipes have flanges at both ends and are formed from cylindrical pipe members whose flow path cross-section is the same shape as the openings provided in the flanges of the intake pipes 8 and exhaust pipes 9. The fuel piping 11 and cooling water piping 10, 12 of adjacent fuel cell systems 1 are connected via connecting pipes (e.g., rubber piping). As a result, the connected linear intake pipe (main intake piping) 8, exhaust pipe (main exhaust piping) 9, fuel piping (main fuel piping) 11, and cooling water piping 10, 12 are positioned between the row of upper power generation modules 2A and the row of lower power generation modules 2B. In addition, the wiring contained within the power boxes 19 of adjacent fuel cell systems 1 are electrically connected.

[0052] As described above, the intake pipe 8, exhaust pipe 9, fuel pipe 11, and cooling water pipes 10 and 12 are connected in a straight line, which suppresses pressure loss compared to cases where there are bends. In addition, all of these pipes are accessible from the front, resulting in excellent workability.

[0053] Furthermore, as described above, in each fuel cell system 1, the intake pipe 8 has a flow path cross-sectional area in the portion sandwiched between flanges on the left and right sides (hereinafter also referred to as the "flow path portion") which is larger than the area of ​​the opening provided in the flange, and the volume of the flow path portion is larger than that of the exhaust pipe 9. For this reason, the air supplied to the intake pipe 8 via the aforementioned joint is stored in the flow path portion before flowing into the intake branch pipe 13 connected to the upper power generation module 2A and the intake branch pipe 13 connected to the lower power generation module 2B. In other words, the flow path portion functions similarly to a surge tank in the intake system of an internal combustion engine, and effects such as equalization of the air supplied to the two upper and lower power generation modules 2 can be obtained.

[0054] A second frame 40 is connected to one end (the right end in Figure 7) in the left-right direction of a row of multiple fuel cell systems 1 connected together (hereinafter also referred to as the fuel cell row). The second frame 40 is fixedly supported by an air inlet pipe 41, one end of which is connected to an intake pipe 8; an exhaust outlet pipe 42, one end of which is connected to an exhaust pipe 9; a power converter 43; a fuel inlet pipe 45, one end of which is connected to a fuel pipe 11; a cooling water inlet pipe 44, one end of which is connected to a cooling water pipe 10; and a cooling water outlet pipe 46, one end of which is connected to a cooling water pipe 12. Hereinafter, the second frame 40, air inlet pipe 41, exhaust outlet pipe 42, power converter 43, fuel inlet pipe 45, cooling water inlet pipe 44, and cooling water outlet pipe 46 will be collectively referred to as the external connection module 47.

[0055] At the other end of the fuel cell array in the left-right direction, the openings of the intake pipe 8, exhaust pipe 9, and fuel pipe 11 are closed with lids or plugs. Also, the end of the cooling water pipe 10 and the end of the cooling water pipe 12 are connected.

[0056] The other end of the air intake pipe 41 is connected to an intake system (not shown) equipped with a blower 57, etc., located outside the fuel cell train. The other end of the exhaust outlet pipe 42 is open to the atmosphere. Alternatively, the other end of the exhaust outlet pipe 42 may be connected to an exhaust treatment system (not shown) located outside the fuel cell train.

[0057] The other end of the fuel inlet pipe 45 is connected to a fuel system (not shown) that includes a fuel tank, a pressure regulating valve, etc. The other ends of the cooling water inlet pipe 44 and the cooling water outlet pipe 46 are connected to a cooling system (not shown) that includes a cooling water tank, a circulation pump, a radiator, etc.

[0058] The power converter 43 is electrically connected to each power box 19 of the fuel cell array via power wiring. In other words, the power generated by each power generation module 2 of the fuel cell array is output through a single power converter 43. By consolidating the power converter 43 into one in this way, the following effects can be obtained. First, the installation area of ​​the power plant can be reduced compared to a configuration in which a power converter 43 is placed for each individual fuel cell system 1. Also, when a cooling mechanism for the power converter 43 is provided, the cooling mechanism configuration is simplified because there is only one cooling target, and costs can be reduced. Furthermore, when connecting even more fuel cell systems 1, a fuel cell array may be formed to the right of the external connection module 47 in Figure 7, similar to the left side. In this case, the air inlet pipe 41, exhaust outlet pipe 42, fuel inlet pipe 45, cooling water inlet pipe 44, and cooling water outlet pipe 46 are each branched and connected to the fuel cell array connected to the right side. The power wiring is similar, and the fuel cell array on the right side is also electrically connected to the power converter 43.

[0059] Each fuel cell system 1's power generation module 2 can be removed from the insertion surface by disconnecting the connections between the pipes 13, 14, and 26 and the auxiliary structure 7 from the non-insertion surface side, disconnecting the main power line and branch power line on the insertion surface side, and disconnecting the main power and signal line wiring and branch wiring. However, in a power plant consisting of multiple fuel cell systems 1, since the intake pipes 8 and exhaust pipes 9 of each fuel cell system 1 are connected in series, simply disconnecting the connections between the auxiliary structure 7 and the intake branch pipe 13 and exhaust branch pipe 14 will leave the intake port 7A and exhaust port 7B open to the atmosphere. In this case, the power plant must be shut down to replace one power generation module 2.

[0060] Furthermore, when the fuel cell system 1 is shut down for inspection or other purposes, it is necessary to stop the supply of air and fuel gas. However, in order to inspect only a specific power generation module 2 while the power plant is operating, a mechanism is needed to stop the supply only to the power generation module 2 being inspected. The same applies to the power transmission path, including the busbar 18, and the power and signal lines.

[0061] Therefore, the fuel cell system 1 of this embodiment has a mechanism described below that makes it possible to stop only the specific power generation module 2 mentioned above.

[0062] Figure 8(A) shows the piping route of the intake system, Figure 8(B) shows the piping route of the exhaust system, and Figure 8(C) shows the circuit of the power system that transmits the electricity generated by the power generation module 2.

[0063] As shown in Figure 8(A), the intake system comprises an intake main piping consisting of intake pipes 8 of each fuel cell system 1 and fittings 54 connecting them, an air inlet pipe 41 connected to the intake main piping, a blower 57 that supplies air to the intake main piping via the air inlet pipe 41, and intake branch pipes 13 of each fuel cell system 1. Each intake branch pipe 13 is provided with a shut-off valve 50 that can open and close the flow path. Note that the shut-off valves 50 are omitted in Figures 1 to 7.

[0064] As shown in Figure 8(B), the exhaust system comprises an exhaust main pipe consisting of exhaust pipes 9 for each fuel cell system 1 and fittings 55 connecting them, an exhaust outlet pipe 42 connected to the exhaust main pipe, and exhaust branch pipes 14 for each fuel cell system 1. Each exhaust branch pipe 14 is provided with a shut-off valve 51 that can open and close the flow path. Note that the shut-off valves 51 are omitted in Figures 1 to 7.

[0065] As shown in Figure 8(C), the power system comprises the main power lines 53 of each fuel cell system 1, the power lines 56 connecting them, the power converter 43, and the busbars 18 of each fuel cell system 1. Each busbar 18 is equipped with a circuit breaker 52. Note that the circuit breakers 52 are omitted in Figures 1 to 7.

[0066] Although not shown in the diagram, a shut-off valve is also provided between the fuel pipe 11 and the fuel injection unit 24.

[0067] Next, we will explain the effects obtained from the fuel cell system 1 described above and the power plant using it.

[0068] According to this embodiment, a stationary fuel cell system 1 is provided, comprising: an auxiliary equipment structure 7 including an auxiliary device for exchanging gas with a fuel cell stack 6; two power generation modules 2 each having a first fuel cell stack 6A connected to at least one of the vertical surfaces of the auxiliary equipment structure 7; a piping module 3 having an intake pipe 8 through which air supplied to the power generation modules 2 flows, and an exhaust pipe 9 through which air discharged from the power generation modules 2 flows; and a power recovery module (electrical equipment module) 4 connected to a branch power line 18 drawn from the fuel cell stack 6 and having a main power line 53 that sends the power generated by the power generation modules 2 to an external power converter 43. In this system, the two power generation modules 2 are arranged stacked vertically, the piping module 3 and the main power line 53 are arranged between the two stacked power generation modules 2, the intake pipe 8 and the exhaust pipe 9 are arranged side by side, and the main power line 53 is arranged side by side with the intake pipe 8 and the exhaust pipe 9 at a position facing the exhaust pipe 9 with the intake pipe 8 in between. This suppresses heat transfer from the exhaust pipe 9 to the main power line 53 due to radiation and convection. As a result, thermal degradation of the main power line 53 can be suppressed. In addition, a fuel cell stack (second fuel cell stack 6B) may be connected to the other side of the auxiliary equipment structure 7 in the vertical direction. In this case, the installation area will be the same as when only the first fuel cell stack 6A is used, so the output performance can be further improved.

[0069] In this embodiment, the system includes a frame 5 that houses the power generation module 2 and the piping module 3, a wiring passage 23 formed along the frame members constituting the frame 5 through which at least a portion of the busbar 18 passes, and a power box 19 that houses the main power line 53. The wiring passage 23 and the power box 19 are made of insulated metal members. This reduces the frequency with which live parts such as the busbar 18 and electrical wires come into contact with the frame members when the system is disassembled for maintenance and inspection work.

[0070] In this embodiment, the piping module 3 further includes an intake branch pipe 13 connecting the intake pipe 8 to the auxiliary equipment structure 7, and an exhaust branch pipe 14 connecting the exhaust pipe 9 to the auxiliary equipment structure 7. Shut-off valves 50 and 51 are interposed in the intake branch pipe 13 and the exhaust branch pipe 14, and a circuit breaker 52 is interposed in the busbar (branch power line) 18. This makes it possible to stop only any fuel cell system 1 in a power plant composed of multiple fuel cell systems 1, thereby improving the efficiency of maintenance and inspection work.

[0071] In this embodiment, the intake pipe 8 has a flow path portion sandwiched between the openings at both ends, and the cross-sectional area of ​​that portion is larger than the area of ​​the openings. As a result, the flow path portion functions similarly to a surge tank in the intake system of an internal combustion engine, achieving effects such as equalization of the air supplied to the two upper and lower power generation modules 2.

[0072] In this embodiment, when viewed from above, the intake pipe 8 is positioned to overlap with the fuel cell stack 6, while the exhaust pipe 9 is positioned not to overlap with the fuel cell stack 6. This allows heat emitted from the exhaust pipe 9 to escape upwards more easily, thereby suppressing the temperature rise of electrical components such as the fuel injection unit 24.

[0073] In this embodiment, the busbar 18 extends from the upper or lower surface of the fuel cell stack 6 in a direction different from the direction of the exhaust pipe 9 and is connected to the main power line 53. This suppresses heat transfer from the exhaust pipe 9 to the busbar 18.

[0074] Although embodiments of the present invention have been described above, these embodiments only represent a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

Claims

1. An auxiliary equipment structure including an auxiliary device for exchanging gas with a fuel cell stack, and two power generation modules each having a fuel cell stack connected to at least one of the vertical surfaces of the auxiliary equipment structure, A piping module comprising an intake pipe through which air supplied to the power generation module flows, and an exhaust pipe through which air discharged from the power generation module flows, An electrical module having a main power line connected to a branch power line drawn from the fuel cell stack, which sends the power generated by the power generation module to an external power converter, In a stationary fuel cell system equipped with, The two aforementioned power generation modules are arranged stacked vertically, The piping module and the main power line are positioned between the two power generation modules that are stacked on top of each other. The intake pipe and the exhaust pipe are arranged side by side. The main power line is positioned parallel to the intake pipe and the exhaust pipe, facing the exhaust pipe with the intake pipe in between. Stationary fuel cell system.

2. In the stationary fuel cell system according to claim 1, A frame for housing the power generation module and the piping module, A wiring passage is formed along the frame member constituting the frame, through which at least a portion of the branch power line passes, A power box in which the aforementioned main power lines are housed, Equipped with, A stationary fuel cell system in which the wiring passage and the power box are formed from insulated metal components.

3. In the stationary fuel cell system according to claim 1, The piping module further comprises an intake branch pipe connecting the intake pipe and the auxiliary structure, and an exhaust branch pipe connecting the exhaust pipe and the auxiliary structure. A shut-off valve is interposed between the intake branch pipe and the exhaust branch pipe. Circuit breakers are installed in the aforementioned branch power lines. Stationary fuel cell system.

4. In the stationary fuel cell system according to claim 1, The aforementioned intake pipe is a stationary fuel cell system in which the cross-sectional area of ​​the flow path portion sandwiched between the openings at both ends is larger than the area of ​​the openings.

5. In the stationary fuel cell system according to claim 1, A stationary fuel cell system in which, when viewed from above, the intake pipe is positioned to overlap with the fuel cell stack, and the exhaust pipe is positioned not to overlap with the fuel cell stack.

6. In the stationary fuel cell system according to claim 5, A stationary fuel cell system in which the branch power lines extend from the upper or lower surface of the fuel cell stack in a direction different from the direction of the exhaust pipe and are connected to the main power line.

7. In the stationary fuel cell system according to claim 1, A stationary fuel cell system in which a fuel cell stack is also connected to the other side of the aforementioned auxiliary structure in the vertical direction.

Images