Stationary fuel cell systems and power plants

Abstract

This stationary fuel cell system comprises: a plurality of power generation modules, which comprise an auxiliary machine structure that includes an auxiliary machine for exchanging gas with fuel cell stacks, a first fuel cell stack connected to one surface of the auxiliary machine structure in the vertical direction, and a second fuel cell stack connected to the other surface of the auxiliary machine structure in the vertical direction; and a piping module, which comprises an intake pipe through which air supplied to the power generation modules flows, an exhaust pipe through which gas discharged from the power generation modules flows, and a fuel pipe through which fuel supplied to the power generation modules flows. The plurality of power generation modules are disposed so as to be stacked in the vertical direction, and the piping module is disposed between two of the stacked power generation modules.

Description

Technical Field

[0001] The present invention relates to a stationary fuel cell system and a power generation plant.

Background Art

[0002] JP2018 - 41720A discloses a multi-stack fuel cell system (hereinafter also referred to as a multi-stack FC) including two fuel cell stack assemblies stacked along a vertical direction and a heat exchanger assembly disposed therebetween. Further, the above document discloses a power generation plant in which a plurality of multi-stack FCs are arranged two-dimensionally in a horizontal direction. In this power generation plant, a part of a duct for exchanging fuel and air between the multi-stack FC and BOP (Balance Of Plant) is routed to the side of each multi-stack FC.

Summary of the Invention

[0003] In a configuration in which multi-stack FCs are arranged two-dimensionally in a horizontal direction, as in the power generation plant disclosed in the above document, there is a problem that the installation area, including the area for arranging ducts, becomes larger as the number of multi-stack FCs used increases.

[0004] Therefore, an object of the present invention is to provide a fuel cell system in which the area required for installing fuel cells is smaller and a power generation plant including the same.

[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; a plurality of power generation modules, each having a first fuel cell stack connected to one vertical surface of the auxiliary equipment structure and a second fuel cell stack connected to the other vertical surface of the auxiliary equipment structure; and a piping module having an intake pipe through which air supplied to the power generation modules flows, an exhaust pipe through which gas discharged from the power generation modules flows, and a fuel piping through which fuel supplied to the power generation modules flows. In this stationary fuel cell system, the plurality of power generation modules are arranged in a vertical stack, and the piping module is arranged between two stacked power generation modules.

[0006] According to another aspect of the present invention, a power plant is provided that includes the above-described stationary fuel cell system. This power plant includes a plurality of stationary fuel cell systems arranged in a direction perpendicular to the vertical direction, and a power converter that aggregates and outputs the electricity generated by these plurality of stationary fuel cell systems. [Brief explanation of the drawing]

[0007] [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. [Modes for carrying out the invention]

[0008] Embodiments of the present invention will be described below with reference to the drawings.

[0009] 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 connections to the respective pipes 13 and 14 of the auxiliary equipment structure 7, which will be described later, are provided is defined as the front. In the left-right direction, the front view is used as the reference.

[0010] 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.

[0011] The fuel cell system 1 comprises two power generation modules 2, one piping module 3, one power recovery module 4, and a frame 5 that supports them.

[0012] 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.

[0013] 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.

[0014] 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.

[0015] 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.

[0016] 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 gas 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 12 may be referred to as the inlet cooling water pipe 12, and cooling water pipe 10 as the outlet cooling water pipe 10.

[0017] 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 in power and control input / output signals necessary for driving auxiliary equipment from external facilities.

[0018] 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.

[0019] Inside the frame 5, two power generation modules 2 are arranged stacked vertically, with a piping module 3 placed between them. Hereafter, when it is necessary to distinguish between the upper and lower power generation modules 2, the upper one will be referred to as the upper power generation module 2A, and the lower one as the lower power generation module 2B.

[0020] By stacking two power generation modules 2 vertically, the area required for installing the fuel cell system 1 can be reduced compared to a configuration where two power generation modules 2 are installed on the same plane (hereinafter also referred to as a flat layout). Furthermore, in the case of a flat layout, piping such as intake pipes 8 and exhaust pipes 9 are placed between adjacent power generation modules 2, and piping branching from there to each auxiliary equipment structure 7 is installed. In contrast, in the fuel cell system 1 of this embodiment, the piping module 3 is placed between the power generation modules 2 that are stacked vertically, so when viewed from above, the area occupied by piping is smaller compared to a flat layout. In other words, according to the fuel cell system 1 of this embodiment, it is possible to further reduce the area required for installing a fuel cell system 1 equipped with multiple power generation modules 2.

[0021] The frame 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 comprises at least 12 frame members assembled in a box shape to surround the upper power generation module 2A, a cross member 20 arranged to cross the left and right sides defined by the frame members in the front-rear direction, and first stays 22 and second stays 21 arranged to cross the front and rear sides (i.e., the front and 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 comprises at least 4 frame members connecting the upper portion and the lower portion at predetermined intervals in the vertical direction.

[0022] The upper power generation module 2A has a state in which the first fuel cell stack 6A is disposed above the auxiliary structure 7 and the second fuel cell stack 6B is disposed below. Hereinafter, this state is also 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 disposed below the auxiliary structure 7 and the second fuel cell stack 6B is disposed above. That is, it is in a state where the upper power generation module 2A is vertically inverted about an axis extending in the front-rear direction. Hereinafter, this state is also referred to as the inverted state. In addition, the portion surrounding the upper power generation module 2A of the frame body 5 and the portion surrounding the lower power generation module 2B of the frame body 5 are also in a relationship where the same structure is vertically inverted. Thus, by using two power generation modules 2 of the same structure, one in the upright state and the other in the inverted state, the cost can be reduced compared to the case of using a plurality of types of power generation modules 2. Furthermore, by adopting the same structure for the upper and lower parts, the same shape and dimensions can be used for each pipe and each wiring between the piping module 3 and the power generation module 2, and the cost can also be reduced thereby.

[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 back 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 back 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 back surface of the frame body 5. 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, 12 are supported by brackets 25 provided on the frame body 5.

[0025] Flanges are provided at both ends of the intake pipe 8 and exhaust pipe 9 in the left-right direction. When multiple fuel cell systems 1 are connected in the left-right direction, as will be described later, these flanges are fastened together with bolts or the like.

[0026] 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).

[0027] 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.

[0028] 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 in the auxiliary equipment structure 7.

[0029] 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.

[0030] The intake port 7A and exhaust port 7B are located on the front side of the auxiliary equipment 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.

[0031] 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.

[0032] 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 control valves, shut-off valves, and actuators that drive each valve body (none 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.

[0033] 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.

[0034] 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. As a result, ancillary equipment such as shut-off valves (not shown) included in the piping module 3 can also be concentrated on the front side. Therefore, according to 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.

[0035] 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.

[0036] 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 air 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.

[0037] 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, and from the fuel injection unit 24 to the power generation module 2 via a fuel supply pipe 26. 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 12 are connected by a first coolant branch pipe 16, and the coolant gallery 27 and the outlet coolant piping 10 are connected by a second coolant branch pipe 17. In other words, coolant is supplied from the inlet coolant piping 12 to the coolant gallery 27 via the first coolant branch pipe 16, where it cools the fuel injector, and then flows into the outlet coolant piping 10 via the second coolant branch pipe 17.

[0038] 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. The busbar 18 is taken out from the side opposite to the side in contact with the auxiliary structure 7 of the fuel cell stack 6 and connected to the power box 19 through a wiring passage 23 provided along the frame member of the frame 5.

[0039] 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.

[0040] Next, with reference to Figure 6, the method for attaching the power generation module 2 to the frame 5 will be explained.

[0041] 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.

[0042] Guide grooves 33 are provided on the opposing surfaces of the pair of cross members 20, 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.

[0043] Then, the back surface of the frame 5 is used as the insertion surface, and the power generation module 2 is moved from this insertion surface along the guide groove 33 using the first slide portion 31 and the second slide portion 32, 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. This makes positioning easier. Also, since the insertion surface is on the back side and the connection parts between the auxiliary structure 7 and each pipe are on the front side of the auxiliary structure 7, the power generation module 2 can be removed from the frame 5 by disconnecting the connection to each pipe. In other words, when replacing the power generation module 2, etc., it is not necessary to remove each pipe from the frame 5.

[0044] 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.

[0045] Next, a power plant utilizing fuel cell system 1 will be described with reference to Figure 7.

[0046] Figure 7 is a front view of a power plant utilizing fuel cell system 1.

[0047] As shown in the diagram, 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 rigidly connected pair of frame members function as reinforcing members for each other, suppressing deformation of the frames 5. In addition, 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 directly or via connecting piping. The same applies to the exhaust pipes 9. The fuel piping 11 and cooling water piping 10, 12 of adjacent fuel cell systems 1 are connected via connecting piping (e.g., rubber piping). As a result, the connected linear intake pipes 8, exhaust pipes 9, 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 housed in the power boxes 19 of adjacent fuel cell systems 1 is electrically connected.

[0048] 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.

[0049] 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 intake 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, intake 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.

[0050] 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.

[0051] The other end of the intake pipe 41 is connected to an intake system (not shown) equipped with a blower or the like, 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.

[0052] 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.

[0053] 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 intake pipe 41, exhaust 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.

[0054] Next, we will explain the effects obtained from the fuel cell system 1 described above and the power plant using it.

[0055] The fuel cell system 1 of this embodiment includes a plurality of (two in this embodiment) power generation modules 2, each comprising an auxiliary equipment structure 7 including an auxiliary equipment for exchanging gas with a fuel cell stack 6, a first fuel cell stack 6A connected to one vertical surface of the auxiliary equipment structure 7, and a second fuel cell stack 6B connected to the other vertical surface of the auxiliary equipment structure 7, and a piping module 3 comprising an intake pipe 8 through which air supplied to the power generation modules 2 flows, an exhaust pipe 9 through which gas discharged from the power generation modules 2 flows, a fuel pipe 11 through which fuel supplied to the power generation modules 2 flows, and cooling water pipes 10 and 12 for injection units through which cooling water for cooling the fuel injection units flows. The plurality of power generation modules 2 are arranged stacked vertically, and the piping module 3 is positioned between two stacked power generation modules 2.

[0056] This reduces the area required for installing the fuel cell system 1 compared to when multiple power generation modules 2 are laid flat. Furthermore, in the case of flat placement, piping such as intake pipes 8 and exhaust pipes 9 are placed between adjacent power generation modules 2, and piping branching from there to each auxiliary equipment structure 7 is installed. In contrast, in this embodiment, the piping module 3 is placed between the power generation modules 2 which are stacked vertically, so when viewed from above, the area occupied by piping is smaller compared to flat placement. In other words, according to this embodiment, it is possible to further reduce the area required for installing the fuel cell system 1 equipped with multiple power generation modules 2, which leads to an improvement in the power density and power generation efficiency of the fuel cell system 1.

[0057] The fuel cell system 1 of this embodiment further comprises a frame 5 that houses the power generation module 2 and the piping module 3, an intake branch pipe 13 that connects the intake pipe 8 to the auxiliary structure 7, an exhaust branch pipe 14 that connects the auxiliary structure 7 to the exhaust pipe 9, and a fuel branch pipe 15 that connects the fuel piping 11 to the auxiliary structure 7 via a fuel injection unit 24. The intake branch pipe 13, exhaust branch pipe 14, and fuel branch pipe 15 are all connected to the front side of the auxiliary structure 7 when viewed from above, and each power generation module 2 is housed in the frame 5 with the front-to-rear central axis Cm of the first fuel cell stack 6A and the second fuel cell stack 6B offset from the front-to-rear central axis Cf of the frame 5. This ensures a distance between the intake port 7A and the exhaust port 7B and the frame 5, and provides ample space for routing the intake branch pipe 13 and the exhaust branch pipe 14.

[0058] The fuel cell system 1 of this embodiment further includes an intake branch pipe 13 connecting the intake pipe 8 to the auxiliary structure 7, an exhaust branch pipe 14 connecting the auxiliary structure 7 to the exhaust pipe 9, and a fuel branch pipe 15 connecting the fuel piping 11 to the auxiliary structure 7 via a fuel injection unit 24. The intake branch pipe 13, exhaust branch pipe 14, and fuel branch pipe 15 are all connected to the front side of the auxiliary structure 7 when viewed from above, and the intake, exhaust, and fuel inlets and outlets of the auxiliary structure 7 are aligned in the left-right direction when viewed from the front, with the arrangement of the intake, exhaust, and fuel inlets and outlets of the auxiliary structure 7 being reversed between the power generation module 2A above the piping module 3 and the power generation module 2B below the piping module 3. This allows the position of the auxiliary equipment of the intake branch pipe 13 to be distributed, and provides more flexibility in the routing of the intake branch pipe 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.

[0059] In this embodiment, the fuel cell system 1 has the same structure for both the upper power generation module 2A and the lower power generation module 2B relative to the piping module 3. The upper power generation module 2A is housed upright relative to the piping module 3, while the lower power generation module 2B is housed in an inverted position relative to the piping module 3, both within the frame 5. This reduces costs compared to using multiple types of power generation modules 2.

[0060] The fuel cell system 1 of this embodiment further includes a power box 19 for recovering electricity generated by the power generation module 2, and the power box 19 is positioned together with the piping module 3 between two stacked power generation modules 2. This reduces the area required for the installation of the fuel cell system 1.

[0061] The power plant of this embodiment, which includes the fuel cell system 1 described above, has multiple fuel cell systems 1 arranged in a direction perpendicular to the vertical direction, and is equipped with a power converter 43 that aggregates and outputs the electricity generated by these multiple fuel cell systems 1. This reduces the area required for the installation of the power plant compared to the case where a power converter 43 is provided for each fuel cell system 1.

[0062] 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. A plurality of power generation modules comprising: an auxiliary equipment structure including an auxiliary device for exchanging gas with a fuel cell stack; a first fuel cell stack connected to one of the vertical surfaces of the auxiliary equipment structure; and a second fuel cell stack connected to the other vertical surface of the auxiliary equipment structure; A piping module comprising: an intake pipe through which air supplied to the power generation module flows; an exhaust pipe through which gas discharged from the power generation module flows; and a fuel pipe through which fuel supplied to the power generation module flows. In a stationary fuel cell system equipped with, Multiple of the aforementioned power generation modules are arranged stacked vertically, A stationary fuel cell system in which the piping module is positioned between two of the power generation modules that are stacked on top of each other.

2. In the stationary fuel cell system according to claim 1, A frame for housing the power generation module and the piping module, An intake branch pipe connecting the intake pipe and the auxiliary equipment structure, An exhaust branch pipe connecting the auxiliary equipment structure and the exhaust pipe, A fuel branch pipe connecting the fuel piping and the auxiliary equipment structure via a fuel injection unit, Furthermore, The intake branch pipe, the exhaust branch pipe, and the fuel branch pipe are all connected to the front side of the auxiliary equipment structure when viewed from above. A stationary fuel cell system in which each of the aforementioned power generation modules is housed in the frame such that the front-to-rear central axes of the first fuel cell stack and the second fuel cell stack are offset from the front-to-rear central axis of the frame.

3. In the stationary fuel cell system according to claim 1, A frame for housing the power generation module and the piping module, An intake branch pipe connecting the intake pipe and the auxiliary equipment structure, An exhaust branch pipe connecting the auxiliary equipment structure and the exhaust pipe, A fuel branch pipe connecting the fuel piping and the auxiliary equipment structure via a fuel injection unit, Furthermore, The intake branch pipe, the exhaust branch pipe, and the fuel branch pipe are all connected to the front side of the auxiliary equipment structure when viewed from above. The intake, exhaust, and fuel inlets and outlets of the aforementioned auxiliary structure are arranged in the left-right direction when viewed from the front. A stationary fuel cell system in which the arrangement of the intake, exhaust, and fuel inlets and outlets of the auxiliary equipment structure is reversed between the power generation module above the piping module and the power generation module below the piping module.

4. In the stationary fuel cell system according to claim 3, The power generation module above the piping module and the power generation module below the piping module have the same structure. A stationary fuel cell system in which the upper power generation module is housed in an upright position relative to the piping module, and the lower power generation module is housed in an inverted position relative to the piping module, both within the frame.

5. In the stationary fuel cell system according to claim 1, The system further includes a power box for recovering the electricity generated by the aforementioned power generation module. A stationary fuel cell system in which the power box is positioned together with the piping module between two stacked power generation modules.

6. In a power plant equipped with a stationary fuel cell system as described in claim 1, Multiple stationary fuel cell systems are arranged in a direction perpendicular to the vertical direction, A power plant equipped with a power converter that aggregates and outputs the electricity generated by these multiple stationary fuel cell systems.

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