JP2023153738A - fuel cell module - Google Patents

Abstract

To provide a fuel cell module capable of suppressing the generation of damages of a conductive part by a thermal expansion while suppressing an expansion of a temperature distribution in each of a plurality of fuel battery cells.SOLUTION: A fuel cell module comprises: a plurality of cell stacks CS into which a plurality of fuel battery cells is laminated; a bus bar that fetches an electric energy output from each fuel battery cell; a conductive part 80 that electrically connects adjacent two cell stacks or the cell stack and the bus bar; a housing that houses the plurality of cell stacks and the conductive part; and a warming burner 65 that generates a fuel gas for heating each fuel battery cell. The two cell stacks are arranged oppositely by a fuel gas with a predetermined interval so as to allow warming. The conductive part includes: plate-like extension parts 812 and 912 extended to a stack arrangement direction in a plane surface; and a stress release part 83 that is easily deformed as compared with the other part when it is heated by the fuel gas flowing the cell stacks to be a thermal expansion.SELECTED DRAWING: Figure 6

Description

The present disclosure relates to fuel cell modules.

Conventionally, an electrochemical cell stack in which a plurality of solid oxide fuel cells are arranged in eight rows of 16 solid oxide fuel cells has been known (for example, see Patent Document 1). In this electrochemical cell stack, adjacent solid oxide fuel cells are electrically connected by a current collecting member.

Further, Patent Document 1 describes an example in which a stress relaxation part formed by flattening a part of the current collecting member is provided in the current collecting member. According to this, even if the fuel cells thermally expand due to heating and the relative positions of adjacent fuel cells change, the flattened portion of the current collecting member can be relatively easily removed. It is bent and deformed by force. Therefore, even if the fuel cell thermally expands and the relative positions of adjacent fuel cells change, the stress generated at the joint between the fuel cell and the current collecting member is alleviated. Therefore, the risk of damage to the joint between the fuel cell and the current collecting member can be reduced.

JP 2021-36504 Publication

By the way, in a fuel cell module having a plurality of solid oxide fuel cells as described in Patent Document 1, it is necessary to heat each of the plurality of fuel cells in order to start the fuel cells. In addition, in a fuel cell module having multiple fuel cells, when the fuel cells generate electricity, the temperature of each of the multiple fuel cells is need to be adjusted.

Here, when a fuel cell module has a plurality of cell stacks accommodating a plurality of stacked fuel cells, if the temperature distribution of each combustion battery cell housed in each cell stack expands, the efficiency of the fuel cell module deteriorates. do. For this reason, the fuel cell module is required to reduce the temperature distribution of each combustion battery cell housed in each cell stack.

In addition, when a plurality of cell stacks are electrically connected using a conductive part that electrically connects the cell stacks, the fuel cell module is configured such that when the conductive part is heated together with the fuel cell, the conductive part is required to be resistant to damage due to thermal expansion.

An object of the present disclosure is to provide a fuel cell module that can suppress the expansion of the temperature distribution of each of a plurality of combustion battery cells and suppress the occurrence of damage to conductive parts due to thermal expansion.

A fuel cell module,
a plurality of cell stacks (CS) in which a plurality of fuel cells (C) are stacked to output electrical energy through an electrochemical reaction between fuel gas and oxidant gas;
a bus bar (BB) provided between the plurality of cell stacks and for extracting electrical energy output from the fuel cell;
Among the plurality of cell stacks, the cell stack is provided spanning either between two adjacent cell stacks or between one of the two cell stacks and a bus bar, and is provided between two cell stacks or one of the two cell stacks. a conductive part (80, 90) that electrically connects the cell stack and the bus bar;
a housing (70) having a housing space (BS) that accommodates a plurality of cell stacks and a conductive part;
A warm-up burner (65) that generates combustion gas to warm up the plurality of cell stacks and heat the fuel cells and blows it into the storage space,
The two cell stacks are arranged opposite to each other at a predetermined interval so that combustion gas can flow between the two cell stacks to warm up the cell stacks.
The conductive parts are plate-shaped extension parts (812, 822, 842, 845, 851, 852a, 861a, 862a, 912 ), and stress relaxation parts (83, 843, 846, 852c, 852e, 861c) that are more easily deformed than other parts when the conductive part is heated and thermally expanded by the combustion gas flowing between the two cell stacks. , 862c, 92).

According to this, combustion gas flowing between two adjacent cell stacks causes a gap between the two cell stacks or between one of the two cell stacks and the bus bar. It is possible to heat the extending portion of the conductive portion provided across the conductive portion. Therefore, even if heat is released from the outermost fuel cell among the plurality of fuel cells stacked in the cell stack, the emitted heat is blocked by the heated extension section. Therefore, the heat released from the fuel cell becomes difficult to be released to the outside of the cell stack. Therefore, the temperature distribution between the outermost fuel cell of the stacked fuel cells and the fuel cells located inside the outermost fuel cell increases. can be restrained from doing so.

Further, even if the conductive part is heated and thermally expanded by the combustion gas flowing between two adjacent cell stacks, the stress relaxation part, which is more easily deformed than other parts, is deformed. Therefore, by absorbing the amount of deformation of the conductive part due to thermal expansion as the amount of deformation of the stress relaxation part, the stress generated between the conductive part and the cell stack due to the thermal expansion of the conductive part is alleviated. can do. Therefore, it is possible to suppress the occurrence of damage to the connecting portion between the conductive part and the cell stack.

Note that the reference numerals in parentheses attached to each component etc. indicate an example of the correspondence between the component etc. and specific components etc. described in the embodiments to be described later.

1 is a schematic configuration diagram of a fuel cell system including a fuel cell module according to a first embodiment. FIG. 2 is an explanatory diagram for explaining an electrochemical reaction inside a fuel cell. FIG. 2 is a schematic perspective view of a cell stack according to the first embodiment. FIG. 3 is a schematic vertical cross-sectional view showing the arrangement of cell stacks within the battery container of the first embodiment. FIG. 2 is a schematic cross-sectional view showing the arrangement of cell stacks within a battery container. It is a typical perspective view showing the arrangement form of a cell stack and a stack connection part of a 1st embodiment in a battery container. It is a typical top view showing the arrangement form of the cell stack and the stack connection part of a 1st embodiment in a battery container. FIG. 2 is a schematic perspective view showing the arrangement of the cell stack and the busbar connection portion of the first embodiment within the battery container. FIG. 3 is a perspective view of the stack connection section of the first embodiment. It is a figure showing the connection part of the stack connection part and the cell stack of 1st Embodiment. It is a top view of a thin plate connection part. FIG. 3 is an explanatory diagram for explaining a state during warm-up processing in a fuel cell module. FIG. 3 is an explanatory diagram for explaining a state during power generation processing in a fuel cell module. It is a figure for explaining the state in which the thin plate connection part of 1st Embodiment deforms. It is a typical perspective view showing the arrangement form of the cell stack and the busbar connection part of a 2nd embodiment in the battery container of a 2nd embodiment. It is a perspective view of the stack connection part of 2nd Embodiment. It is a figure which shows the state at the time of assembling the stack connection part of 2nd Embodiment. It is a figure for explaining the state in which the stack connection part of 2nd Embodiment deforms. FIG. 7 is an explanatory diagram for explaining the flow of combustion gas during warm-up processing in the fuel cell module of the second embodiment. It is a perspective view of the stack connection part of 3rd Embodiment. It is a perspective view of the stack connection part of 4th embodiment. It is a figure for explaining the state in which the stack connection part of 4th Embodiment deforms.

Embodiments of the present disclosure will be described below with reference to the drawings. In the following embodiments, parts that are the same or equivalent to those described in the preceding embodiments are given the same reference numerals, and their explanations may be omitted. Further, in the embodiment, when only some of the constituent elements are described, the constituent elements explained in the preceding embodiment can be applied to other parts of the constituent element. The following embodiments can be partially combined with each other, even if not explicitly stated, as long as the combination does not cause any problems.

(First embodiment)
This embodiment will be described with reference to FIGS. 1 to 14. In this embodiment, as shown in FIG. 1, an example in which a fuel cell module 1 of the present disclosure is applied to a fuel cell system FS including a solid oxide fuel cell 10 will be described.

The fuel cell module 1 is a hot module that includes a fuel processing system and a battery system, and maintains a high temperature by covering these with a heat insulating material. The fuel cell module 1 includes a solid oxide fuel cell 10, an air preheater 22, a stack temperature controller 23, a reformer 33, an off-gas combustor 63, a catalytic combustor 69, a container 70, an ejector 51, and a warm-up unit. It includes a burner 65 and the like.

The solid oxide fuel cell 10 is generally called SOFC (Solid Oxide Fuel Cell), and operates at a high temperature (eg, 500° C. to 1000° C.). The fuel cell 10 includes a plurality of fuel cells C that output electrical energy through an electrochemical reaction between a fuel gas and an oxidant gas (oxygen in the air in this example). Hereinafter, the fuel cell C will be simply referred to as cell C.

As shown in FIG. 2, the cell C includes an electrolyte body EL, an air electrode (i.e., cathode) CA, a fuel electrode (i.e., anode) AN, and a separator (not shown) that forms an air flow path and a fuel flow path. has been done. Cell C uses hydrogen and carbon monoxide as fuel gas. This fuel gas is produced by reforming city gas (that is, gas whose main component is methane), which is a raw material for reforming. Note that the reforming raw material to be used may be a gas other than city gas as long as it is a hydrocarbon gas.

Cell C outputs electrical energy to external circuit EC through an electrochemical reaction of hydrogen and oxygen shown in reaction formulas F1 and F2 below.

(Fuel electrode) 2H ₂ +2O ^2- → 2H ₂ O+4e ^- … (F1)

(Air electrode) O ₂ +4e ⁻ →2O ²⁻ …(F2)
Further, the cell C outputs electrical energy to the external circuit EC through an electrochemical reaction of carbon monoxide and oxygen shown in reaction formulas F3 and F4 below.

(Fuel electrode) 2CO+2O ^2- →2CO ₂ +4e ^- …(F3)

(Air electrode) O ₂ +4e ⁻ →2O ²⁻ …(F4)
The fuel cell 10 includes a plurality of cell stacks CS configured by stacking a predetermined number of cells C. As shown in FIG. 3, in the cell stack CS, flat cells C are stacked in a predetermined stacking direction DRst. A predetermined number of cells C constituting the cell stack CS are electrically connected in series. The cell stack CS is a stacked body in which a predetermined number of cells C are stacked in a line. Cell stack CS is held by holder case HC. Holder case HC is a case that accommodates cell stack CS.

The cell stack CS has a fuel gas inlet IPH, an oxidizing gas inlet IPO, a fuel gas outlet OPH, and an oxidizing gas outlet OPH on one side of the stacked end face EF located at the end of the cell C in the stacking direction DRst. An outlet OPO is formed.

As shown in FIG. 1, the fuel cell 10 configured in this manner has an air preheater 22, a stack temperature regulator 23, a reformer 33, an off-gas combustor 63, a catalytic combustor 69, an ejector 51, etc., and has an adiabatic property. It is arranged inside a container 70 having a. The arrangement of the fuel cell 10 inside the container 70 will be described later.

Furthermore, an inverter INV for extracting electrical energy generated by the fuel cell 10 is connected to the fuel cell 10 . The inverter INV converts DC power generated by the fuel cell 10 into AC power. Specifically, the inverter INV includes a DC-AC inverter that converts DC power generated by the fuel cell 10 into AC power.

An air path 20 that is an air distribution path is connected to the fuel cell 10 . The air path 20 is composed of piping and the like. The air path 20 is provided with a pressure blower 21 that pumps air to the fuel cell 10, an air preheater 22 that heats the air supplied to the fuel cell 10, and a stack temperature regulator 23.

The pressure blower 21 is an oxidizer pump that sucks air from the atmosphere and supplies it to the fuel cell 10. The pressure blower 21 is an electric blower whose operation is controlled by a control signal from an electronic control unit 100, which will be described later.

The air preheater 22 is a heat exchanger that heats the air pumped from the pressure blower 21 by exchanging heat with the combustion gas generated by the off-gas combustor 63 when the fuel cell 10 generates power. The air preheater 22 is provided to reduce the temperature difference between the air supplied to the fuel cell 10 and the fuel gas, thereby improving the power generation efficiency of the fuel cell 10.

The stack temperature controller 23 is connected between the air preheater 22 and the fuel cell 10 so that the air that has passed through the air preheater 22 flows. Thereby, the oxidant gas flows through the stack temperature controller 23 before being supplied to the cell stack CS.

The stack temperature regulator 23 is disposed facing the cell stack CS of the fuel cell 10 at a predetermined distance so as to be able to exchange heat with the cell stack CS. In the stack temperature regulator 23 and the cell stack CS, heat from the stack temperature regulator 23 is transferred to the cell stack CS when the fuel cell 10 is started. Further, in the stack temperature regulator 23 and the cell stack CS, heat from the cell stack CS is transmitted to the stack temperature regulator 23 side when the fuel cell 10 generates power.

The stack temperature controller 23 is a warm-up burner so that when the fuel cell 10 is started, the oxidant gas flowing through the stack temperature controller 23 and the combustion gas generated by a warm-up burner 65 (described later) can exchange heat. It is provided adjacent to a combustion gas flow path 67 through which the combustion gas generated in step 65 flows.

Specifically, the stack temperature regulator 23 includes a first temperature regulator 24 adjacent to the combustion gas flow path 67 and a second temperature regulator 25 into which the oxidant gas that has passed through the first temperature regulator 24 flows. , a connection flow path 26 that connects the first temperature regulator 24 and the second temperature regulator 25. The first temperature regulator 24, the second temperature regulator 25, and the connection channel 26 are integrally configured with a battery container 71, which will be described later.

The first temperature regulator 24 has a first temperature regulating channel 240 into which the air that has passed through the air preheater 22 flows. The first temperature regulator 24 is arranged between the combustion gas flow path 67 and the cell stack CS of the fuel cell 10. The first temperature regulator 24 receives heat from the combustion gas flowing through the combustion gas flow path 67 when the fuel cell 10 is activated, and is heated together with the air flowing through the first temperature adjustment flow path 240 . When starting up the fuel cell 10, heat from the first temperature controller 24 is radiated to the cell stack CS. Furthermore, when the fuel cell 10 generates power, the first temperature regulator 24 absorbs heat from the cell stack CS, which has risen in temperature due to self-heating caused by the power generation, and adjusts the temperature of the cell stack CS.

The second temperature regulator 25 has a second temperature regulating channel 250 into which the air that has passed through the first temperature regulator 24 flows through the connecting channel 26 . The second temperature regulator 25 is arranged on the opposite side of the first temperature regulator 24 with the cell stack CS of the fuel cell 10 interposed therebetween. The air heated by the first temperature regulator 24 flows through the second temperature regulator 25 when the fuel cell 10 is started. When starting up the fuel cell 10, heat from the second temperature controller 25 is radiated to the cell stack CS. Further, when the fuel cell 10 generates power, the second temperature regulator 25 absorbs heat from the cell stack CS, which has risen in temperature due to self-heating due to power generation, and adjusts the temperature of the cell stack CS.

Further, the fuel cell 10 is connected to a fuel path 30 that is a distribution path for reforming raw materials and fuel gas. The fuel path 30 is composed of piping and the like. The fuel path 30 is provided with a fuel pump 31, a desulfurizer 32, an ejector 51, and a reformer 33 in this order from the upstream side.

The fuel pump 31 is a pump for supplying reforming raw material toward the fuel cell 10 side. The fuel pump 31 is an electric pump whose operation is controlled by a control signal from an electronic control unit 100, which will be described later.

The desulfurizer 32 is a device for removing sulfur components contained in the reforming raw material supplied from the fuel pump 31. Note that city gas contains an odorant (specifically, a sulfur component). Since the sulfur component is a catalyst poisoning substance, it needs to be removed upstream of the reformer 33.

The reformer 33 is for reforming the reforming raw material supplied from the fuel pump 31 using steam to generate fuel gas. The reformer 33 includes, for example, a steam reforming catalyst containing a noble metal such as rhodium or ruthenium.

Specifically, the reformer 33 heats a mixed gas containing a raw material for reforming and steam by exchanging heat with combustion gas, and also performs a reforming reaction shown in the following reaction formula F5 and a reaction formula F6. Fuel gas (hydrogen, carbon monoxide) is generated by the shift reaction shown.

_CH4 + _H2O →CO+ _3H2 ...(F5)
CO+ _H2O → _CO2 + _H2 ...(F6)
Here, the steam reforming in the reformer 33 is an endothermic reaction, and has a characteristic that the reforming rate improves under high temperature conditions. For this reason, it is desirable that the reformer 33 be disposed around the fuel cell 10 so that it can absorb the radiant heat released from the cell stack CS to the surroundings when the fuel cell 10 generates power.

A water supply path 40 is connected to the fuel path 30 between the desulfurizer 32 and the reformer 33 . The water supply path 40 is provided with a water pump 41 and a water evaporator 42 . The water pump 41 is a pump that supplies water to the water evaporator 42. The water pump 41 is an electric pump whose operation is controlled by a control signal from an electronic control unit 100, which will be described later. The water evaporator 42 has an evaporation function that converts water from the water pump 41 into steam (that is, gas).

Further, in the fuel path 30, an ejector 51 is provided between the desulfurizer 32 and the reformer 33, downstream of a portion to which the water supply path 40 is connected. The ejector 51 uses the raw fuel upstream of the reformer 33 as a driving flow to suck in off-gas fuel flowing through a suction path 52, which will be described later, and supplies it to the reformer 33 together with the raw fuel.

Specifically, the ejector 51 includes a nozzle section 511 that injects fluid, a suction section 512 that sucks fluid from the outlet side of the fuel cell 10, and a fluid that is injected from the nozzle section 511 and a fluid that is sucked from the suction section 512. It has a discharge part 513 that mixes the mixture and discharges it toward the reformer 33.

The nozzle portion 511 has a constriction structure capable of ejecting fluid. The nozzle portion 511 has a fixed aperture structure with a fixed aperture opening. Further, the discharge section 513 has a flow passage cross-sectional area expanding toward the downstream side so that the pressure is increased after the fluid from the nozzle section 511 and the fluid from the suction section 512 are mixed. Note that the nozzle portion 511 may have a variable aperture structure that can change the aperture opening.

The suction section 512 of the ejector 51 is configured to suck fluid from the exit side of the fuel cell 10 using negative pressure on the exit side of the nozzle section 511 . Specifically, a suction path 52 branching from the fuel discharge path 62 is connected to the suction portion 512 so that fluid flowing through a fuel discharge path 62, which will be described later, is suctioned.

Further, the fuel path 30 is connected to a circulation path 55 that returns a portion of the reformed fuel flowing downstream of the reformer 33 in the fuel path 30 to the upstream side of the fuel pump 31 in the fuel path 30 as circulating gas. The circulation path 55 has one end connected to the fuel path 30 downstream of the reformer 33 and the other end connected to the fuel path 30 upstream of the fuel pump 31 .

The circulation path 55 is provided with a radiator 56 and a circulation adjustment valve 57. The radiator 56 is a heat exchanger that cools the reformed fuel flowing through the circulation path 55 by exchanging heat between the reformed fuel flowing through the circulation path 55 and the water flowing through the water supply path 40 . The circulation adjustment valve 57 is a flow rate adjustment member that adjusts the flow rate of the reformed fuel flowing through the circulation path 55. The circulation regulating valve 57 is composed of an electromagnetic valve whose operation is controlled by a control signal from an electronic control unit 100, which will be described later.

Here, the ejector 51 has a characteristic that as the mass flow rate of the fluid flowing into the nozzle part 511 as a driving flow increases, the flow rate of the suction fluid sucked from the suction part 512 increases. Therefore, by increasing the mass flow rate of the fluid flowing into the nozzle portion 511 of the ejector 51, it is possible to increase the suction flow rate of off-gas fuel sucked from the suction portion 512.

For example, by opening the circulation regulating valve 57 to increase the circulating gas flowing through the circulation path 55, the driving flow of the ejector 51 can be increased without increasing the amount of fuel supplied from outside the system.

Furthermore, an off-gas path 60 through which off-gas discharged from the fuel cell 10 flows is connected to the fuel cell 10 . Specifically, the fuel cell 10 is connected to an air exhaust path 61 through which the oxidant off-gas discharged from the fuel cell 10 flows, and a fuel exhaust path 62 through which the fuel off-gas discharged from the fuel cell 10 flows. has been done.

An off-gas combustor 63 is connected to the off-gas path 60. The off-gas combustor 63 generates combustion gas that raises the temperature of the reformer 33 and the like by burning fuel off-gas and the like. For example, the off-gas combustor 63 burns a mixture of oxidizer off-gas and fuel off-gas as combustible gas during power generation by the fuel cell 10, thereby producing combustion gas for raising the temperature of each device of the fuel cell system FS. generate. The off-gas combustor 63 has an off-gas burner 631 for burning fuel off-gas. In the off-gas combustor 63, combustion of the fuel off-gas is started by ignition of the off-gas burner 631, and combustion gas is generated.

An exhaust gas path 64 for discharging high-temperature exhaust gas is connected to the off-gas combustor 63. The exhaust gas path 64 is connected to the reformer 33 and the air preheater 22 in order from the upstream side in order to effectively utilize the heat of the exhaust gas flowing therein. Thereby, the heat of the off-gas combustor 63 is transferred to the reformer 33 and the air preheater 22. Note that the order in which the combustion gas flows through each device may be changed depending on the amount of heat required by each device.

Further, the exhaust gas path 64 is provided with a catalytic combustor 69 . The catalytic combustor 69 burns the off-fuel and off-air flowing through the exhaust gas path 64. The catalytic combustor 69 is provided on the downstream side of the exhaust gas path 64. Specifically, the catalytic combustor 69 is connected downstream of the air preheater 22 in the exhaust gas path 64 . Note that the catalytic combustor 69 is not limited to this, and may be connected to other positions in the exhaust gas path 64.

Although not shown, an oxidation catalyst is arranged inside the catalytic combustor 69. The catalytic combustor 69 generates combustion heat through an oxidation reaction of off-fuel and off-air at an oxidation catalyst. The catalytic combustor 69 is configured to combust exhaust gas without producing a flame, such as a catalytic converter that purifies exhaust gas from automobiles.

Here, the fuel cell module 1 is provided with a warm-up burner 65 that generates combustion gas for warming up the cell stack CS when the fuel cell 10 is started. The warm-up burner 65 includes a warm-up air path 27 which is an air distribution path provided separately from the air path 20, and a warm-up fuel path 35 through which a portion of the reforming raw material flowing through the fuel path 30 flows. is connected.

The warm-up air path 27 and the warm-up fuel path 35 are configured by piping and the like. The warm-up air path 27 is provided with a warm-up pressure blower 28 that force-feeds air to the warm-up burner 65 . The warm-up pressure blower 28 is an oxidizer pump that sucks air from the atmosphere and supplies it to the warm-up burner 65. The warming-up pressure blower 28 is an electric blower whose operation is controlled by a control signal from an electronic control unit 100, which will be described later.

The warm-up fuel path 35 is provided with a warm-up fuel pump 36 that supplies reforming raw material to the warm-up burner 65. The warm-up fuel pump 36 is a pump that pumps reforming raw material toward the warm-up burner 65. The warm-up fuel pump 36 includes an electric blower whose operation is controlled by a control signal from an electronic control unit 100, which will be described later.

The warm-up burner 65 burns the mixed gas of the air blown from the warm-up pressure blower 28 and the reforming raw material supplied from the warm-up fuel pump 36 as combustible gas. The warm-up burner 65 is connected to a combustion gas passage 67 through which high-temperature combustion gas generated by combustion of combustible gas flows. The combustion gas passage 67 is supplied with high-temperature combustion gas generated by the warm-up burner 65 . Further, this combustion gas flow path 67 is connected to a warm-up air path 27 through which air blown from the warm-up pressure blower 28 flows. As a result, not only combustible gas but also a portion of the air blown from the warm-up pressure blower 28 is introduced into the combustion gas flow path 67 .

The fuel cell 10, the air preheater 22, the reformer 33, the ejector 51, the off-gas combustor 63, the warm-up burner 65, and the like are arranged inside a heat-insulating container 70. The container 70 is a casing that forms the outer shell of the fuel cell module 1. Although not shown, the air preheater 22 and the reformer 33 are installed around the off-gas combustor 63 and the warm-up burner 65 inside the container 70 so as to receive the heat of the off-gas combustor 63 and the warm-up burner 65. It is located in Note that the fuel cell 10 is provided with a separate space insulated from the space in which the air preheater 22, reformer 33, ejector 51, off-gas combustor 63, etc. are housed so as not to directly receive the heat of the off-gas combustor 63. It is located in the space of

The container 70 has a battery container 71 that accommodates the fuel cell 10, as shown in FIGS. 4 and 5. The battery container 71 has a double cylinder structure, and has a donut-shaped space formed inside. This space constitutes an accommodation space BS in which a substantially rectangular parallelepiped cell stack CS is accommodated. The battery container 71 is arranged in such a manner that the axis CL of the battery container 71 extends along the direction in which gravity acts (that is, the vertical direction).

In this embodiment, the direction extending along the axis CL of the battery container 71 is referred to as an axial direction DRa, and the direction passing through the axis CL of the battery container 71 and orthogonal to the axial direction DRa is referred to as the radial direction DRr. The direction along the circle centered on the axis CL is defined as the circumferential direction DRc.

A combustion gas passage 67 through which combustion gas flows is formed inside the container 70 along the axial direction DRa. Further, a housing space BS is formed outside the combustion gas flow path 67 in the radial direction DRr. In the housing space BS inside the battery housing 71, a plurality of cell stacks CS are arranged radially around the axis CL of the battery housing 71. That is, the plurality of cell stacks CS are arranged radially around the combustion gas flow path 67. In other words, the plurality of cell stacks CS are arranged at equal intervals in the circumferential direction DRc in the accommodation space BS. Therefore, the circumferential direction DRc corresponds to the stack arrangement direction, which is the direction in which the plurality of cell stacks CS are arranged. Note that the intervals in the circumferential direction DRc in the plurality of cell stacks CS do not need to be the same, and may be partially different.

The plurality of cell stacks CS arranged radially are electrically connected in series, and adjacent cell stacks CS are electrically connected via stack connection parts 80, which will be described later. The cell stack CS has a terminal T, which will be described later, to which a stack connection section 80 is connected.

At one end and the other end of the plurality of cell stacks CS connected in series, a bus bar BB (to be described later) for extracting the electrical energy output by the electrochemical reaction of the fuel cell 10 is connected to an electric bus bar BB. connected. One end and the other end of the plurality of cell stacks CS are connected to a bus bar BB via a bus bar connection section 90, which will be described later. Then, bus bar BB is connected to inverter INV. In addition, in FIG. 5, the stack connection part 80, the busbar connection part 90, and the busbar BB are omitted.

Among the plurality of cell stacks CS, cell stacks CS that are adjacent to each other in the circumferential direction DRc are arranged with stacked end faces EF facing each other. In other words, the stacked end faces EF of adjacent cell stacks CS in the circumferential direction DRc face each other in the circumferential direction DRc with a predetermined interval therebetween. In addition, in the plurality of cell stacks CS, a part of the side surface extending along the stacking direction DRst faces the inside of the battery container 71 as an inner surface IS, and a part of the other side surface faces the battery container 71 as an outer surface OS. facing the outside. The inner surface IS of the cell stack CS constitutes an inner portion of the cell stack CS when a plurality of cell stacks CS are arranged radially inside the container 70. Further, the outer surface OS of the cell stack CS constitutes an outer portion of the cell stack CS when a plurality of cell stacks CS are arranged radially inside the container 70.

In the plurality of cell stacks CS arranged in the housing space BS in this manner, the interval between two adjacent cell stacks CS in the circumferential direction DRc increases from the inside to the outside in the radial direction DRr. That is, in two cell stacks CS adjacent to each other in the circumferential direction DRc, the distance between the mutually opposing stacked end surfaces EF becomes narrower from the outside to the inside in the radial direction DRr.

As shown in FIG. 4, the battery container 71 of this embodiment includes an inner cylinder 72, an outer cylinder 73 located outside the inner cylinder 72, an upper lid 74 that covers the upper part of the outer cylinder 73, a bottom part of the inner cylinder 72, and an outer cylinder 73 located outside the inner cylinder 72. It is configured to include a base plate 75 that connects the bottom parts of the cylinders 73.

The inner cylinder 72 is located inside the plurality of cell stacks CS in the battery container 71, and is formed to extend along the axial direction DRa. A portion of the inner cylinder 72 protrudes above the upper lid 74. The outer cylinder 73 is positioned outside the plurality of cell stacks CS in the battery container 71. A housing space BS is defined by the inner cylinder 72, the outer cylinder 73, the upper lid 74, and the base plate 75. The inner cylinder 72 and the outer cylinder 73 are each formed into a cylindrical shape. The inner cylinder 72 and the outer cylinder 73 are arranged so that their central axes are coaxial.

The inner cylinder 72 constitutes the first temperature regulator 24 of the stack temperature regulator 23 described above. The inner cylinder 72 is disposed facing the cell stack CS at a predetermined distance so as to be able to exchange heat with the cell stack CS. Specifically, the inner cylinder 72 is disposed facing the cell stack CS at a predetermined interval so as to be able to exchange heat with each of the plurality of cells C stacked in the cell stack CS. The inner cylinder 72 faces the inner surface IS of the cell stack CS with a predetermined distance therebetween so as to receive radiant heat from the cell stack CS when the fuel cell 10 generates power. The dimension of the inner cylinder 72 in the axial direction DRa is larger than the dimension of the cell stack CS in the axial direction DRa so that the inner cylinder 72 can cover the entire inner surface IS of the cell stack CS.

Further, the inner cylinder 72 has a double wall structure including a first inner wall 721 and a first outer wall 722 so that fluid can pass therethrough. The first inner wall 721 and the first outer wall 722 are each formed of a cylindrical body. The first inner wall 721 and the first outer wall 722 are arranged so that their central axes are coaxial. A gap defining portion such as a spacer or a dowel is provided between the first inner wall 721 and the first outer wall 722, and a substantially constant gap is formed by the spacing defining portion.

Air that exchanges heat with the inner surface IS of the cell stack CS is introduced into the gap flow path formed between the first inner wall 721 and the first outer wall 722. Specifically, the air flowing through the gap flow path formed between the first inner wall 721 and the first outer wall 722 flows through a portion of each of the plurality of cells C stacked in the cell stack CS that faces the inner surface IS. exchange heat with In this embodiment, the gap flow path formed in the inner cylinder 72 constitutes the first temperature adjustment flow path 240 . Hereinafter, the gap flow path formed in the inner cylinder 72 will be referred to as a first temperature control flow path 240.

Inside the first inner wall 721, a warm-up burner 65 is arranged on one side in the axial direction DRa, and a combustion gas flow path 67 is formed on the other side of the warm-up burner 65 in the axial direction DRa. ing. That is, the inner cylinder 72 serving as the first temperature regulator 24 is provided adjacent to the combustion gas passage 67 so as to be able to exchange heat between the combustion gas and the oxidizing gas. The inner cylinder 72 is arranged between the combustion gas flow path 67 and the cell stack CS.

A gas introduction hole 723 is formed in the inner cylinder 72 for guiding the combustion gas flowing through the combustion gas passage 67 to the housing space BS of the cell stack CS. The combustion gas flowing through the combustion gas flow path 67 is introduced into the housing space BS through the gas introduction hole 723.

The gas introduction hole 723 is configured to prevent a predetermined cell C from being heated among the plurality of cells C stacked in the cell stack CS by blowing high-temperature combustion gas to a local portion of the cell stack CS. The position of the opening on the housing space BS side is set. That is, the gas introduction hole 723 has an opening on the accommodation space BS side located in a portion of the inner cylinder 72 that does not face the cell stack CS in the direction in which the inner cylinder 72 and the cell stack CS are lined up (radial direction DRr in this example). is formed.

The opening of the gas introduction hole 723 on the side of the combustion gas flow path 67 is formed in a portion of the inner cylinder 72 that does not face the cell stack CS. Specifically, as shown in FIG. 5, the gas introduction holes 723 are connected to adjacent cell stacks CS in the inner cylinder 72 so that combustion gas is introduced into the gap between the adjacent cell stacks CS. It is formed at a position corresponding to the gap between. In other words, the plurality of cell stacks CS are arranged at predetermined intervals in the circumferential direction DRc so that combustion gas blown out from the gas introduction holes 723 can be warmed up by flowing between adjacent cell stacks CS. Ru.

Further, as shown in FIG. 4, the gas introduction hole 723 is located at a position closer to the base plate 75 than the upper lid 74 in the inner cylinder 72 so that combustion gas is also introduced into the gap between the cell stack CS and the base plate 75. It is provided. That is, the gas introduction hole 723 is provided below the center in the axial direction DRa of the portion of the inner cylinder 72 accommodated on the accommodation space BS side.

The outer cylinder 73 constitutes the second temperature regulator 25 of the stack temperature regulator 23 described above. The outer cylinder 73 is formed to extend along the axial direction DRa. The outer cylinder 73 is disposed facing the cell stack CS at a predetermined distance so as to be able to exchange heat with the cell stack CS. Specifically, the outer cylinder 73 is disposed facing the cell stack CS at a predetermined interval so as to be able to exchange heat with each of the plurality of cells C stacked in the cell stack CS. The outer cylinder 73 faces the outer surface OS of the cell stack CS at a predetermined distance so as to receive radiant heat from the cell stack CS when the fuel cell 10 generates power. The dimension of the outer cylinder 73 in the axial direction DRa is larger than the dimension of the cell stack CS in the axial direction DRa so that the outer cylinder 73 can cover the entire outer surface OS of the cell stack CS.

Further, the outer cylinder 73 has a double wall structure including a second inner wall 731 and a second outer wall 732 so that fluid can pass therethrough. The second inner wall 731 and the second outer wall 732 are each configured as a cylindrical body.

The second inner wall 731 and the second outer wall 732 are arranged such that their central axes are coaxial. A gap defining portion such as a spacer or a dowel is provided between the second inner wall 731 and the second outer wall 732, and a substantially constant gap is formed by the spacing defining portion. Air that exchanges heat with the outer surface OS of the cell stack CS is introduced into the gap flow path formed between the second inner wall 731 and the second outer wall 732.

Specifically, the air flowing through the gap flow path formed between the second inner wall 731 and the second outer wall 732 flows through a portion facing the outer surface OS of each of the plurality of cells C stacked in the cell stack CS. exchange heat with In this embodiment, the gap flow path formed in the outer cylinder 73 constitutes the second temperature control flow path 250. Hereinafter, the gap flow path formed in the outer cylinder 73 will be referred to as a second temperature control flow path 250. The second temperature control channel 250 has the other side in the axial direction DRa communicating with a communication path 750, which will be described later, and the one side in the axial direction DRa being connected to the cell stack CS via a pipe or the like (not shown).

The upper lid 74 covers the upper part of the outer cylinder 73, and has a donut-like shape so that a part of the inner cylinder 72 can protrude outward. Piping for supplying fuel gas to the cell stack CS, piping constituting the air exhaust path 61, piping constituting the fuel exhaust path 62, and the like pass through the upper lid 74.

The base plate 75 connects the bottom of the inner cylinder 72 and the bottom of the outer cylinder 73, and has a disk shape. The base plate 75 is a base portion that supports a plurality of cell stacks CS via a stack connection portion 80, a support portion 76 described below, and the like. The base plate 75 faces the lower surface of the cell stack CS. The base plate 75 has a size that can cover the entire lower surface of each of the plurality of cell stacks CS accommodated in the accommodation space BS.

The base plate 75 has a double wall structure including an upper wall 751 and a lower wall 752 to allow fluid to pass through. The upper wall 751 and the lower wall 752 are formed to extend along the radial direction DRr. That is, the upper wall 751 and the lower wall 752 of this embodiment are formed to extend along the horizontal direction. A gap defining portion such as a spacer or a dowel is provided between the upper wall 751 and the lower wall 752, and a substantially constant gap is formed by the spacing defining portion.

The base plate 75 has an upper wall 751 connected to a first outer wall 722 of the inner cylinder 72 and a second inner wall 731 of the outer cylinder 73, and a lower wall 752 connected to the first inner wall 721 of the inner cylinder 72 and the second outer wall 731 of the outer cylinder 73. It is connected to the. A communication passage 750 is formed between the upper wall 751 and the lower wall 752 to communicate the gap passage in the inner cylinder 72 and the gap passage in the outer cylinder 73. That is, the first temperature regulation channel 240 and the second temperature regulation channel 250 are in communication via the communication channel 750.

The communication path 750 formed in this way covers the lower surfaces of all the plurality of cell stacks CS accommodated in the accommodation space BS. Further, the communication path 750 covers a portion of the accommodation space BS that does not face the lower surface of the cell stack CS. That is, the communication path 750 covers the lower surfaces of all the cell stacks CS accommodated in the accommodation space BS, as well as the gaps between adjacent cell stacks CS among the plurality of cell stacks CS accommodated in the accommodation space BS. is covered. The communication path 750 corresponds to the connection flow path 26 described above.

Furthermore, a plurality of cell stacks CS are provided on the base plate 75 to be arranged within the accommodation space BS. Specifically, as shown in FIG. 4, the base plate 75 is provided with a support part 76 that supports the cell stack CS, and the support part 76 supports each of the plurality of cell stacks CS arranged in the accommodation space BS. is supported. The support portion 76 has, for example, a cylindrical shape extending in the axial direction DRa, and one side in the axial direction DRa is connected to the cell stack CS, and the other side is connected to the base plate 75. Since the cell stack CS is supported by the support portion 76, the combustion gas blown out from the gas introduction hole 723 into the accommodation space BS can be introduced into the gap between the cell stack CS and the base plate 75. Note that the shape of the support portion 76 is not limited to a cylindrical shape, and may be a shape other than a cylindrical shape, such as a cubic shape.

Here, the inner tube 72 has a larger curvature than the outer tube 73, and has a smaller area at a portion facing the cell stack CS. Therefore, the heat transfer area of the inner tube 72 with the cell stack CS is smaller than the heat transfer area of the outer tube 73 with the cell stack CS. In the battery container 71, when the heat transfer area is different between the inside and the outside, fluid at the same temperature and flow rate flows through the gap flow path formed in the inner tube 72 and the gap flow path formed in the outer tube 73. Then, the amount of heat transferred by convection becomes smaller on the inside of the cell stack CS than on the outside.

Specifically, when fluids of the same temperature and the same flow rate flow in the first temperature control flow path 240 and the second temperature control flow path 250, a portion facing the outer surface OS of each of the plurality of cells C in the cell stack CS The amount of heat transferred by convection is smaller in the portion facing the inner surface IS than in the portion opposite to the inner surface IS. This difference in heat transfer amount becomes a factor in expanding the temperature distribution between the inner portion and the outer portion of each of the plurality of cells C in the cell stack CS. Such an expansion of the temperature distribution is undesirable because it leads to a decrease in power generation efficiency and durability.

Taking these into consideration, the battery container 71 has a cell stack that flows into the first temperature control flow path 240 formed in the inner cylinder 72 compared to the fluid flowing into the second temperature control flow path 250 formed in the outer cylinder 73. A fluid having a large temperature difference with the CS flows. For example, when the temperature of the cell C in the cell stack CS is low and it is necessary to warm up the cell C, the first temperature control channel 240 has a temperature higher than the temperature of the fluid flowing into the second temperature control channel 250. A hot fluid is flowing through it. Furthermore, when it is necessary to cool or keep warm the cells C in the cell stack CS, a fluid having a lower temperature than the fluid flowing through the second temperature control flow path 250 flows through the first temperature control flow path 240. ing. Note that the cells C in the cell stack CS need to be cooled or kept warm mainly when the fuel cell 10 is generating power.

Specifically, the communicating path 750 is connected to the downstream side of the first temperature regulating channel 240 and to the upstream side of the second temperature regulating channel 250. As a result, when the fuel cell 10 is started, air heated by the combustion gas flows into the first temperature control flow path 240 , and the first temperature control flow path 240 and the communication path 750 flow into the second temperature control flow path 250 . As the air passes through, heat-radiated air flows into each cell C in the cell stack CS. Furthermore, when the fuel cell 10 generates electricity, air heated by the air preheater 22 flows into the first temperature control flow path 240 and flows through the first temperature control flow path 240 and the communication path 750 into the second temperature control flow path 250. When passing through the cell stack CS, the air receives heat from the cell stack CS and becomes heated.

Further, in the inner cylinder 72 and the outer cylinder 73 of this embodiment, the distance between the first inner wall 721 and the first outer wall 722 and the distance between the second inner wall 731 and the second outer wall 732 are approximately the same size. The inner cylinder 72 has a smaller radius of curvature than the outer cylinder 73. Therefore, the cross-sectional area of the first temperature regulating channel 240 is smaller than that of the second temperature regulating channel 250. According to the law of continuity, when a steady state fluid flows through an unbranched channel, the mass flow rate at any cross section of the channel is equal. In the battery container 71 of this embodiment, the first temperature control flow path 240 and the second temperature control flow path 250 are continuous flow paths in series, and the flow path cross-sectional area of the first temperature control flow path 240 is the same as that of the first temperature control flow path 240. It is smaller than the flow path cross-sectional area of the two-temperature control flow path 250. Therefore, air having a higher flow velocity than the air flowing through the second temperature control flow path 250 flows into the first temperature control flow path 240 .

Next, the stack connection section 80 and the bus bar connection section 90 will be explained with reference to FIGS. 6 to 11. The stack connection portion 80 constitutes a current line that electrically connects each of the plurality of cell stacks CS arranged in the circumferential direction DRc within the housing space BS. As shown in FIGS. 6 and 7, the stack connecting portion 80 is provided across two adjacent cell stacks CS among the plurality of cell stacks CS arranged in the accommodation space BS.

The bus bar connection unit 90 electrically connects each of the cell stacks CS provided at one end and the other end of the plurality of cell stacks CS connected in series in the accommodation space BS to the bus bar BB. It constitutes the current line to be connected. As shown in FIG. 8, the bus bar connection section 90 is located between a cell stack CS provided at one end of a plurality of cell stacks CS connected in series and a bus bar BB and at the other end. It is provided straddling between the provided cell stack CS and the bus bar BB.

Note that the bus bar BB is for extracting the electrical energy output by the electrochemical reaction of the fuel cell 10 to the outside of the fuel cell module 1. Therefore, the cell stack CS provided at one end and the cell stack CS provided at the other end are defined at both ends of the plurality of cell stacks CS connected in series in the direction in which current flows. This is the cell stack CS to be placed.

The plurality of stack connection parts 80 provided across each of two adjacent cell stacks CS have the same configuration. Therefore, only the stack connection section 80 provided across two predetermined cell stacks CS will be described in detail, and detailed explanations of the other stack connection sections 80 will be omitted. Furthermore, the busbar connection portion 90 provided across the cell stack CS at one end and the bus bar BB and the busbar connection portion 90 provided across the cell stack CS at the other end and the busbar BB are connected to each other. The configuration is similar. For this reason, only one busbar connection section 90 will be explained in detail, and a detailed explanation of the other busbar connection section 90 will be omitted. In this embodiment, the stack connection section 80 and the bus bar connection section 90 correspond to the conductive section.

First, the stack connection section 80 provided across two adjacent cell stacks CS will be described. The stack connection portion 80 provided across the mutually adjacent cell stacks CS electrically connects the two cell stacks CS. As shown in FIG. 6, the stack connecting portion 80 is provided in a space below the space between the two cell stacks CS in the axial direction DRa in the accommodation space BS. The stack connecting portion 80 is heated together with the plurality of cells C stacked on each of the two cell stacks CS by introducing combustion gas between the two cell stacks CS.

As shown in FIGS. 6, 7, and 9, the stack connecting portion 80 is connected to a first thick plate connecting portion 81 connected to one of the two cell stacks CS, and to the other cell stack CS. A second thick plate connection portion 82 is connected to the second thick plate connection portion 82. Further, the stack connecting portion 80 includes a thin plate connecting portion 83 disposed between the first thick plate connecting portion 81 and the second thick plate connecting portion 82 . The thin plate connecting portion 83 is held between the first thick plate connecting portion 81 and the second thick plate connecting portion 82 .

The stack connecting portion 80 configured by the first thick plate connecting portion 81, the second thick plate connecting portion 82, and the thin plate connecting portion 83 has a shape that is aligned with the axis CL of the battery container 71 when viewed from the direction along the axial direction DRa. It is formed in a substantially fan shape with the center at the center. Hereinafter, of the two cell stacks CS, the cell stack CS on the side connected to the first thick plate connection part 81 is also referred to as the first cell stack CS1, and the cell stack CS on the side connected to the second thick plate connection part 82 is also called the second cell stack CS2.

The first thick plate connection portion 81 is a member that is difficult to thermally expand even when heated by a current having a relatively large current value, and is made of a heat-resistant metal such as stainless steel. ing. Note that the member of the first thick plate connecting portion 81 is not limited, and may be made of a metal different from stainless steel. The first thick plate connecting portion 81 has a plate shape and is bent so that a cross-sectional view in the radial direction DRr has a substantially U-shape projecting downward in the axial direction DRa.

The first thick plate connecting portion 81 is supported by a first stack contact portion 811 connected to the first cell stack CS1 among the first cell stack CS1 and second cell stack CS2 adjacent to each other, and the base plate 75. It has a first support part 812. Further, the first thick plate connecting portion 81 has a first thin plate side connecting portion 813 that is connected to the thin plate connecting portion 83 . The first stack contact portion 811, the first support portion 812, and the first thin plate side connection portion 813 are integrally formed and have the same size in the thickness direction.

As shown in FIG. 9, the first stack contact portion 811 is connected to one side of the first support portion 812 in the circumferential direction DRc. The first stack abutting portion 811 is a portion of the stack connecting portion 80 that is formed in a substantially fan shape when viewed from the direction along the axial direction DRa, and constitutes one side that extends linearly along the radial direction DRr. It is. The first stack contact portion 811 has a flat plate shape having a plate surface in a direction intersecting the circumferential direction DRc, and extends in a planar shape along the axial direction DRa and the radial direction DRr. The first stack contact portion 811 is formed to have a larger size in the radial direction DRr than in the axial direction DRa. The first stack contact portion 811 has a through hole (not shown) formed therein, and is fixed to the first cell stack CS1 by a fastening screw N fitted into the through hole, as shown in FIG. 10 . Specifically, the first stack contact portion 811 is fixed by a fastening screw N to a terminal T that projects downward from the first cell stack CS1 toward the base plate 75.

The terminal T is made of a conductive member made of a thin metal plate, and has a rectangular plate surface as shown in FIGS. 6 and 10. The terminal T extends along the axial direction DRa and the radial direction DRr in accordance with the shape of the cell stack CS. The terminal T has a terminal surface TS that contacts the first stack contact portion 811. The first stack contact portion 811 has a first stack contact surface 811a that contacts the terminal surface TS. The first stack contact surface 811a extends in a plane along the terminal surface TS.

The first support part 812 is a member that supports the first thick plate connection part 81 and is arranged on the base plate 75. The first support portion 812 is not fixed to the base plate 75, but is placed on the base plate 75. The first support portion 812 has a substantially triangular shape having a thickness direction in the axial direction DRa, and extends in a planar shape along the radial direction DRr and the circumferential direction DRc.

The first support portion 812 covers a portion of the base plate 75 above the axial direction DRa. Specifically, the first support portion 812 covers a portion of the base plate 75 located between the first cell stack CS1 and the second cell stack CS2. That is, in the first support portion 812, the lower surface in the axial direction DRa contacts the base plate 75, and the upper surface faces the accommodation space BS side. The upper surface of the first support portion 812 faces the space between the first cell stack CS1 and the second cell stack CS2. As a result, when the fuel cell 10 generates power, the upper surface of the first support portion 812 receives heat from the first cell stack CS1 and the second cell stack CS2. Hereinafter, the surface of the first support part 812 located on the accommodation space BS side and facing the first cell stack CS1 and the second cell stack CS2 will also be referred to as the first support surface 812a.

The first support surface 812a is formed to expand along the radial direction DRr and the circumferential direction DRc so that the area facing the first cell stack CS1 and the second cell stack CS2 is as large as possible. That is, the first support surface 812a of this embodiment is formed to extend horizontally along the upper wall 751 of the base plate 75.

The first thin plate side connecting portion 813 is connected to the other side of the first supporting portion 812 in the circumferential direction DRc. The first thin plate side connecting portion 813 has a flat plate shape having a plate surface in a direction intersecting the circumferential direction DRc, and extends in a planar shape along the axial direction DRa. The first thin plate side connecting portion 813 has a substantially right triangular shape when viewed in cross section in a direction perpendicular to the plate thickness direction. The first thin plate side connecting portion 813 has a triangular flat plate shape whose base is the portion connected to the first supporting portion 812, and the size in the axial direction DRa decreases from the outside to the inside in the radial direction DRr. ing.

The thin plate connecting portion 83 is fixed to the surface of the first thin plate side connecting portion 813 facing the outer cylinder 73 by, for example, welding. Hereinafter, the surface of the first thin plate side connecting portion 813 to which the thin plate connecting portion 83 is fixed is also referred to as the first thin plate connecting surface 813a. The first thin plate connection surface 813a extends in the axial direction DRa. Note that the method of fixing the first thin plate side connecting portion 813 and the thin plate connecting portion 83 is not limited to welding, and may be fixed using an adhesive or the like, for example.

The second thick plate connecting portion 82 is made of stainless steel, which is the same member as the first thick plate connecting portion 81. The second thick plate connecting portion 82 has a plate shape and is bent so that a cross-sectional view in the radial direction DRr has a substantially U-shape projecting downward in the axial direction DRa. The second thick plate connecting portion 82 is connected to a second stack contact portion 821 connected to the second cell stack CS2 of two adjacent cell stacks CS, and a second support portion 822 supported by the base plate 75. , and a second thin plate side connecting portion 823 connected to the thin plate connecting portion 83. The second stack contact portion 821, the second support portion 822, and the second thin plate side connection portion 823 are integrally formed and have the same size in the thickness direction.

The second stack contact portion 821 is connected to the other side of the second support portion 822 in the circumferential direction DRc. The second stack contact portion 821 is a portion forming the other side of the stack connection portion 80 that is formed in a substantially fan shape when viewed from the direction along the axial direction DRa, and extends linearly along the radial direction DRr. It is. The second stack contact portion 821 has a flat plate shape having a plate surface in a direction intersecting the circumferential direction DRc, and extends in a planar shape along the axial direction DRa and the radial direction DRr. The second stack contact portion 821 is formed to have a larger size in the radial direction DRr than in the axial direction DRa. The second stack contact portion 821 has a through hole (not shown) formed therein, and is fixed to the second cell stack CS2 by a fastening screw N fitted into the through hole. Specifically, the second stack contact portion 821 is fixed by a fastening screw N to a terminal T that projects downward from the second cell stack CS2 toward the base plate 75. The terminal T is made of a conductive member made of a thin metal plate, and has a rectangular plate surface. The second stack contact portion 821 has a second stack contact surface 821a that contacts the terminal T. The second stack abutting surface 821a extends along a plane like the first stack abutting surface 811a.

In this way, in the stack connecting part 80, the first stack contact part 811 constitutes one side of the stack connecting part 80 formed in a substantially fan shape and extends linearly along the radial direction DRr, and The contact portion 821 constitutes the other side that extends linearly along the radial direction DRr. Therefore, when arranging the stack connection portion 80 between the first cell stack CS1 and the second cell stack CS2, which become narrower from the outside to the inside in the radial direction DRr, Since it is easier to insert the connector, it is possible to improve the ease of assembly. Then, it becomes easier to bring the first stack contact surface 811a and the second stack contact surface 821a into contact with the terminals T of the first cell stack CS1 and the second cell stack CS2, respectively.

The second support portion 822 is a member that supports the second thick plate connection portion 82 and is disposed on the base plate 75. The second support portion 822 is not fixed to the base plate 75, but is placed on the base plate 75. The second support portion 822 has a substantially rectangular parallelepiped shape with the thickness direction in the axial direction DRa, and extends in a planar manner along the radial direction DRr and the circumferential direction DRc.

The second support portion 822 covers a portion of the base plate 75 above the axial direction DRa. Specifically, the second support portion 822 covers a part of the base plate 75 located between the first cell stack CS1 and the second cell stack CS2. That is, in the second support portion 822, the lower surface in the axial direction DRa contacts the base plate 75, and the upper surface faces the accommodation space BS side. The upper surface of the second support portion 822 faces the space between the first cell stack CS1 and the second cell stack CS2. As a result, when the fuel cell 10 generates power, the upper surface of the second support portion 822 receives heat from the first cell stack CS1 and the second cell stack CS2. Hereinafter, the surface of the second support part 822 located on the accommodation space BS side and facing the first cell stack CS1 and the second cell stack CS2 will also be referred to as the second support surface 822a.

The second support surface 822a is formed to expand along the radial direction DRr and the circumferential direction DRc so that the area facing the first cell stack CS1 and the second cell stack CS2 is as large as possible. That is, the second support surface 822a of this embodiment is formed to extend horizontally along the upper wall 751 of the base plate 75. Although the second support part 822 has a different shape from the first support part 812, the shapes of the first support part 812 and the second support part 822 are not limited, and may have the same shape as the first support part 812. It may be. In this embodiment, the first support part 812 and the second support part 822 correspond to the extension part in the stack connection part 80.

The second thin plate side connecting portion 823 is connected to one side of the second support portion 822 in the circumferential direction DRc. The second thin plate side connecting portion 823 has a flat plate shape having a plate surface in a direction intersecting the circumferential direction DRc, and extends in a planar shape along the axial direction DRa. The second thin plate side connecting portion 823 has a substantially right triangular shape when viewed in cross section in a direction perpendicular to the axial direction DRa plate thickness direction. The second thin plate side connecting portion 823 has a triangular flat plate shape whose base is the portion connected to the second support portion 822, and the size in the axial direction DRa decreases from the outside to the inside in the radial direction DRr. ing.

Further, the second thin plate side connecting portion 823 is arranged to face the first thin plate side connecting portion 813, and has the same shape. The thin plate connecting portion 83 is fixed to the surface of the second thin plate side connecting portion 823 facing the outer cylinder 73 by, for example, welding. Hereinafter, the surface of the second thin plate side connecting portion 823 to which the thin plate connecting portion 83 is fixed is also referred to as the second thin plate connecting surface 823a. The second thin plate connecting surface 823a extends in the axial direction DRa.

The thin plate connecting portion 83 is made of stainless steel, which is the same material as the first thick plate connecting portion 81 and the second thick plate connecting portion 82, and is formed into a thin plate shape. However, the thin plate connecting portion 83 is formed of a thin plate member whose size in the thickness direction is smaller than the size of the first thick plate connecting portion 81 and the second thick plate connecting portion 82 in the thickness direction. That is, the first thick plate connecting portion 81 and the second thick plate connecting portion 82 are formed of thick plate members whose size in the thickness direction is larger than the size of the thin plate connecting portion 83 in the thickness direction. . In other words, the thin plate connecting portion 83 is smaller in size in the plate thickness direction than the first supporting portion 812 and the second supporting portion 822. Further, the first thick plate connecting portion 81, the second thick plate connecting portion 82, and the thin plate connecting portion 83 are formed separately from each other.

The thin plate connecting portion 83 is formed by being bent so that its cross-sectional view in the axial direction DRa has a V-shape. That is, as shown in FIG. 11, the thin plate connecting portion 83 is bent into a V-shape such that a first plate portion 831 having a rectangular parallelepiped shape and a second plate portion 832 having a rectangular parallelepiped shape face each other. It is formed by The thin plate connecting portion 83 is bent in a direction intersecting the circumferential direction DRc.

The thin plate connecting portion 83 has a side facing the inner tube 72 where the first plate portion 831 and a second plate portion 832 are connected, and a side facing the outer tube 73 is open. In the thin plate connecting portion 83, the first plate portion 831 is connected to the first thin plate connecting surface 813a, and the second plate portion 832 is connected to the second thin plate connecting surface 823a. That is, the thin plate connecting portion 83 is connected to the first supporting portion 812 via the first thin plate side connecting portion 813 and to the second supporting portion 822 via the second thin plate side connecting portion 823. Thereby, the thin plate connecting portion 83 is held between the first thin plate side connecting portion 813 and the second thin plate side connecting portion 823. In this embodiment, the first thin plate side connecting part 813 corresponds to the first clamping part, the first thin plate connecting surface 813a corresponds to the first clamping surface, and the second thin plate side connecting part 823 corresponds to the second clamping part. However, the second thin plate connecting surface 823a corresponds to the second clamping surface.

The first plate portion 831 extends along the axial direction DRa. Further, the first plate portion 831 extends toward the inner cylinder 72 from a portion connected to the first thin plate connecting surface 813a. The first plate portion 831 is formed to have a larger size in the axial direction DRa than in a direction toward the inner cylinder 72 from a portion connected to the first thin plate connecting surface 813a. That is, the first plate portion 831 is formed so that the size of the plate surface in the axial direction DRa is larger than the size in the direction perpendicular to the axial direction DRa.

Hereinafter, as shown in FIG. 11, the imaginary straight line along which the first plate portion 831 extends toward the inner cylinder 72 will also be referred to as the first imaginary straight line CL1. The first imaginary straight line CL1 is an imaginary line along the direction in which the plate surface on the side facing the second plate part 832 in a cross-sectional view of the first plate part 831 in the axial direction DRa extends.

The second plate portion 832 extends along the axial direction DRa. Further, the second plate portion 832 extends toward the inner cylinder 72 from a portion connected to the second thin plate connecting surface 823a. The size of the second plate portion 832 in the axial direction DRa is larger than the size in the direction toward the inner cylinder 72 from the portion connected to the second thin plate connecting surface 823a. That is, the second plate portion 832 is formed so that the size of the plate surface in the axial direction DRa is larger than the size in the direction perpendicular to the axial direction DRa.

Hereinafter, as shown in FIG. 11, the imaginary straight line along which the second plate portion 832 extends toward the inner tube 72 will also be referred to as the second imaginary straight line CL2. The second imaginary straight line CL2 is an imaginary line along the direction in which the plate surface on the side facing the first plate part 831 in a cross-sectional view of the second plate part 832 in the axial direction DRa extends.

The thin plate connecting portion 83 in this embodiment is formed so that the bending angle θ, which is the angle formed by the first virtual straight line CL1 and the second virtual straight line CL2, is an acute angle. Specifically, the thin plate connecting portion 83 is formed so that the bending angle θ is 60° or less. Note that the thin plate connection portion 83 may be formed so that the bending angle θ is an acute angle, so that the bending angle θ is smaller than 60° (for example, 45° or less), or may be formed at an angle larger than 60°. (for example, 70 degrees or more).

When combustion gas is introduced into the gap between the first cell stack CS1 and the second cell stack CS2, the combustion gas is blown onto the thin plate connecting portion 83 configured in this way, as shown in FIG. Then, when the stack connecting portion 80 is heated by being blown with combustion gas, the thin plate connecting portion 83 is heated together with the first thick plate connecting portion 81 and the second thick plate connecting portion 82 .

When the stack connecting portion 80 is heated by the combustion gas and thermally expands, the thin plate connecting portion 83 is pressed by the thermally expanding first thick plate connecting portion 81 and second thick plate connecting portion 82. , has a structure that is more easily deformed than other parts of the stack connection part 80. Specifically, the thin plate connecting portion 83 is configured such that the V-shaped portion thereof is more easily deformed than other portions of the stack connecting portion 80 . Hereinafter, the V-shaped bent portion will also be referred to as the V-shaped bent portion 833. In this embodiment, the thin plate connecting portion 83 corresponds to the stress relaxation portion in the stack connecting portion 80 and the V-shaped bent portion 833 corresponds to the bent portion in the stack connecting portion 80.

Next, the bus bar connection section 90 provided across the cell stack CS and the bus bar BB will be explained. As shown in FIG. 8, the busbar connection section 90 includes a stack side connection section 91 connected to the cell stack CS and a busbar side connection section 92 connected to the busbar BB.

The stack side connecting portion 91 is made of stainless steel, which is the same material as the first thick plate connecting portion 81 and the second thick plate connecting portion 82. Further, the stack side connecting portion 91 is plate-shaped like the first thick plate connecting portion 81, and has a substantially U-shape in cross section in the radial direction DRr that protrudes downward in the axial direction DRa. It is formed by being bent. The stack side connection section 91 has a first connection section 911 connected to the cell stack CS, a connection support section 912 supported by the base plate 75, and a second connection section 913 connected to the busbar side connection section 92. . The stack side connecting portion 91 is formed to have substantially the same shape as the second thick plate connecting portion 82 .

Specifically, the first connection portion 911 has substantially the same shape as the second stack contact portion 821. The connection support portion 912 has the same shape as the second support portion 822 . The second connection portion 913 has the same shape as the second thin plate side connection portion 823. The first connecting portion 911, the connecting support portion 912, and the second connecting portion 913 are integrally formed and have the same size in the thickness direction. In the stack-side connecting portion 91, a first connecting portion 911 is fixed to the terminal T of the cell stack CS by a fastening screw N. In this embodiment, the connection support portion 912 corresponds to the extension portion of the busbar connection portion 90.

The bus bar side connecting portion 92 is made of stainless steel, which is the same material as the thin plate connecting portion 83, and is formed in substantially the same shape as the thin plate connecting portion 83. That is, the bus bar side connecting portion 92 is formed by bending a thin plate member so that the cross-sectional view in the axial direction DRa is V-shaped. In the busbar side connecting portion 92, the plate portions on one side and the plate portions on the other side face each other so as to face each other.

Of these one side plate part and the other side plate part, one side plate part is fixed to the second connection part 913 of the stack side connection part 91 by, for example, welding, and the other side plate part is fixed to the bus bar BB. For example, it is fixed by welding. The busbar side connecting portion 92 is smaller in size in the thickness direction than the stack side connecting portion 91. Further, the stack side connecting portion 91 and the bus bar side connecting portion 92 are formed separately from each other.

In the bus bar side connection part 92 configured in this way, the connection support part 912 is heated by introducing combustion gas into the gap between the cell stacks CS provided at one end and the other end. When expanded, it is pressed against the connection support part 912. The busbar side connection portion 92 is configured to be more easily deformed when pressed by the connection support portion 912 than other portions of the busbar connection portion 90 . Specifically, the bus bar side connecting portion 92 has a configuration in which the V-shaped bent portion is more easily deformed than other portions of the stack connecting portion 80 . Hereinafter, the V-shaped bent portion will also be referred to as the busbar side bent portion 921. In the present embodiment, the busbar side connecting portion 92 corresponds to the stress relaxation portion in the busbar connecting portion 90 , and the busbar side bent portion 921 corresponds to the bent portion in the busbar connecting portion 90 .

Next, the electronic control unit 100 of the fuel cell system FS will be explained. The electronic control unit 100 is composed of a microcomputer including a processor and memory, and its peripheral circuits. The electronic control unit 100 performs various calculations and processes based on a control program stored in a memory, and controls the operations of various control devices connected to the output side.

A temperature sensor (not shown) or the like is connected to the input side of the electronic control unit 100, and the detection result of the sensor is input to the electronic control unit 100. Further, an operation panel (not shown) is connected to the input side of the electronic control unit 100. The operation panel is an operation unit that includes a start switch for turning on and off power generation of the fuel cell 10.

In addition, on the output side of the electronic control unit 100, as control devices, a pressure blower 21, a warm-up pressure blower 28, a fuel pump 31, a warm-up fuel pump 36, a water pump 41, an off-gas burner 631, and a warm-up burner are installed. A control device such as 65 is connected. The operation of these control devices is controlled according to control signals output from the electronic control section 100.

Next, the overall operation of the fuel cell system FS will be explained. The fuel cell system FS is executed by the electronic control unit 100 when the start switch is turned on. When the start switch is turned on, the electronic control unit 100 executes a warm-up process.

The warm-up process is a process of raising the temperature of various devices including the cell stack CS to an appropriate temperature. During the warm-up process, the electronic control unit 100 operates the warm-up pressure blower 28 and the warm-up fuel pump 36, and also operates the warm-up burner 65 while supplying fuel and air to the combustion gas flow path 67. ignite. When the warm-up burner 65 is ignited, a mixed gas of fuel and air is burned as a combustible gas, thereby generating high-temperature combustion gas.

In the stack temperature regulator 23 of this embodiment, the first temperature regulator 24 is provided adjacent to the combustion gas flow path 67. Therefore, the temperature of the air flowing through the first temperature regulator 24 and the first temperature regulating channel 240 is increased by the combustion gas flowing through the combustion gas channel 67. The air heated in the first temperature regulator 24 flows to the second temperature regulator 25 via the connection channel 26, and then is supplied to the cell stack CS. As a result, during the warm-up process, as shown in FIG. The inside of the cell stack CS is heated by introducing the air into the cell stack CS. Specifically, during warm-up processing, each of the plurality of cells C stacked inside the cell stack CS is heated from the outside by radiant heat transfer H1, H2, and H3, and the air heated by the stack temperature controller 23 is heated. As a result, these plurality of cells C are heated from inside.

Moreover, the high temperature combustion gas flowing through the combustion gas flow path 67 is introduced into the housing space BS through the gas introduction hole 723, and flows into each of the gaps between the plurality of cell stacks CS lined up along the circumferential direction DRc. Then, the outside of each cell stack CS is heated by convection heat transfer H4 caused by the combustion gas flowing into each of the gaps between the plurality of cell stacks CS.

Further, when performing the warm-up process, the convection heat transfer H4 caused by the combustion gas causes the stack connection portion 80 and the bus bar connection portion 90 to be provided across each of two adjacent cell stacks CS in the plurality of cell stacks CS. is heated. Specifically, the first thick plate connecting portion 81, the second thick plate connecting portion 82, and the thin plate connecting portion 83 of the stack connecting portion 80 are heated by convective heat transfer H4 caused by the combustion gas. Further, the stack-side connection portion 91 and the bus-bar side connection portion 92 of the bus-bar connection portion 90 are heated by convection heat transfer H4 caused by the combustion gas.

The combustion gas introduced into the housing space BS is introduced into the exhaust gas path 64 via the air exhaust path 61 of the off-gas path 60 and the off-gas combustor 63. The combustion gas introduced into the exhaust gas path 64 radiates heat to the reformer 33 and the air preheater 22 while flowing through the exhaust gas path 64 . As a result, the temperatures of the reformer 33 and the air preheater 22 rise.

After starting the warm-up process, the electronic control unit 100 continues the warm-up process until the power generation conditions are met. The power generation conditions include, for example, the reformer 33 reaches a temperature (e.g., 300°C) at which it can generate fuel gas, and the cell C reaches a temperature (e.g., 500°C or higher) suitable for power generation by the fuel cell 10. Occasionally it is true. The electronic control unit 100 continues the warm-up process until the power generation conditions are met. Furthermore, when the power generation conditions are met, the electronic control unit 100 executes power generation processing.

During power generation processing, the electronic control unit 100 controls the pressure blower 21, the fuel pump 31, and the water pump 41 so that the fuel cell 10 is supplied with an amount of oxidizing gas and fuel gas suitable for power generation. Further, the electronic control unit 100 turns off the warm-up pressure blower 28, the warm-up fuel pump 36, and the warm-up burner 65, and ignites the off-gas burner 631.

Thereby, as shown in FIG. 13, the fuel gas generated in the reformer 33 is supplied to the cell stack CS. Further, the oxidant gas blown out from the pressure blower 21 flows into the air preheater 22 and is heated by heat exchange with the combustion gas flowing through the exhaust gas path 64 . The air that has passed through the air preheater 22 flows through the first temperature control channel 240, the communication path 750, and the second temperature control channel 250 in this order. The air passing through the first temperature control flow path 240, the communication path 750, and the second temperature control flow path 250 absorbs heat from the fuel cell 10 and rises in temperature to around the cell temperature of the fuel cell 10, and then flows into the fuel cell 10. .

At this time, air with a low temperature and a high flow velocity flows into the first temperature regulation channel 240, which has a smaller heat transfer area with the cell stack CS than the second temperature regulation channel 250. According to this, the difference between the amount of heat transfer due to convection on the inside of the cell stack CS in the radial direction DRr and the amount of heat transfer due to convection on the outside of the radial direction DRr becomes smaller, and each of the plurality of cells C in the cell stack CS The temperature distribution between the part and the outer part is reduced.

When the oxidant gas and fuel gas are supplied to the cell stack CS, the cell C outputs electrical energy through the reactions shown in the above reaction formulas F1 to F4. Then, the off-gas discharged from the cell stack CS is burned in the off-gas combustor 63 as combustible gas. The combustion gas generated in the off-gas combustor 63 radiates heat to the reformer 33, the air preheater 22, and the water evaporator 42 while flowing through the exhaust gas path 64.

After starting the power generation process, the electronic control unit 100 determines whether a stop condition for stopping the power generation of the fuel cell 10 is satisfied. The stop condition is satisfied, for example, when the start switch is turned off. The electronic control unit 100 continues the power generation process until the stop condition is satisfied. Further, when the stop condition is satisfied, the electronic control unit 100 stops the operation of the pressure blower 21, the fuel pump 31, and the water pump 41.

By the way, heat radiation from the fuel cell 10 to the air passing through the first temperature control flow path 240 etc. during power generation processing is due to the heat dissipation from each cell C stacked in the cell stack CS due to self-heat generation accompanying power generation. This is done by releasing heat to the outside of the cell stack CS. Among the plurality of cells C stacked in the cell stack CS, the further away from the center of the cell stack CS the cell stack CS is provided, the more easily its own heat is released to the outside of the cell stack CS. Therefore, the amount of heat released to the outside of the cell stack CS is the largest from the outermost cell C among the stacked cells C.

On the other hand, a cell C provided inside the outermost cell C is adjacent to a cell C other than itself whose temperature has been raised by self-heating, so it transfers its own heat to the outside of the cell stack CS. is difficult to release. For this reason, there is a possibility that the temperature distribution may expand between the outermost cell C among the plurality of stacked cells C and the cells C provided inside the outermost cell C. .

In contrast, when the fuel cell module 1 of the present embodiment executes the warm-up process, the combustion gas flows into the gaps between each of the plurality of cell stacks CS arranged at equal intervals in the circumferential direction DRc. The stack connection portion 80 is heated by this. Specifically, the first support part 812 and the second support part 822 of the stack connection part 80 provided across the two cell stacks CS are heated by the combustion gas flowing into the gap between the two cell stacks CS adjacent to each other. . The first support portion 812 and the second support portion 822 extend in a planar manner along the radial direction DRr and the circumferential direction DRc, and cover a portion of the base plate 75 between the two cell stacks CS. .

In addition, in the fuel cell module 1 of this embodiment, when performing warm-up processing, the cell stacks provided at one end and the other end of the plurality of cell stacks CS connected in series. The busbar connection portion 90 is heated by the combustion gas flowing into the gap with the CS. Specifically, the combustion gas flowing into the gap between the cell stacks CS provided at one end and the other end supports the connection of the busbar connection portion 90 provided across these two cell stacks CS and the busbar BB. 912 is heated. The connection support portion 912 extends in a planar manner along the radial direction DRr and the circumferential direction DRc similarly to the first support portion 812 and the second support portion 822. That is, the connection support portion 912 covers the base plate 75 between the cell stacks CS provided at one end and the other end.

Therefore, as shown in FIG. 13, radiation heat is transferred from the outermost cell C of the stacked cells C toward the heated first support part 812 and second support part 822. Even if H5 is released, this radiant heat transfer H5 is blocked by the heated first support part 812 and second support part 822. Therefore, the radiant heat transfer H5 emitted from the cell C becomes difficult to be emitted to the outside of the cell stack CS.

Furthermore, even if heat is released from the outermost cell C of the stacked cells C toward the heated connection support part 912, the released heat is transferred to the heated connection support part 912. Blocked at 912. Therefore, the heat emitted from the cell C becomes difficult to be emitted to the outside of the cell stack CS. Therefore, the amount of heat emitted from the outermost cell C among the plurality of stacked cells C and the amount of heat emitted from the cells C provided inside the outermost cell C are different. It is possible to suppress the difference from expanding.

Therefore, expansion of the temperature distribution between the outermost cell C among the plurality of stacked cells C and the cell C provided inside the outermost cell C is suppressed. can do.

Furthermore, when the stack connecting portion 80 is heated by the combustion gas flowing into the gap between two adjacent cell stacks CS during the warm-up process, the stack connecting portion 80 may thermally expand and deform. There is.

Here, as described above, in the warm-up burner 65 of this embodiment, the warm-up burner 65 is arranged on one side in the axial direction DRa inside the first inner wall 721. A combustion gas flow path 67 is formed on the other side in the axial direction DRa. Further, the gas introduction hole 723 for introducing high-temperature combustion gas into the housing space BS is provided below the center in the axial direction DRa of the portion of the inner cylinder 72 that is accommodated on the housing space BS side. Therefore, the combustion gas generated by the warm-up burner 65 flows through the combustion gas passage 67 from one side in the axial direction DRa to the other side and is blown out from the gas introduction hole 723 into the housing space BS. It flows within the space BS toward the other side in the axial direction DRa. Thereby, the combustion gas blown out into the accommodation space BS can easily flow toward the stack connection part 80. Therefore, in the stack connecting portion 80, the first thick plate connecting portion 81, the second thick plate connecting portion 82, and the thin plate connecting portion 83 are heated and thermally expanded by the combustion gas blown into the housing space BS.

However, since the first stack contact portion 811 is fixed to the terminal T of the first cell stack CS1 by the fastening screw N, the first thick plate connecting portion 81 thermally expands away from the first cell stack CS1. . Further, since the second stack contact portion 821 is fixed to the terminal T of the second cell stack CS2 by the fastening screw N, the second thick plate connecting portion 82 thermally expands away from the second cell stack CS2. . For this reason, the thin plate connecting part 83 provided between the first thick plate connecting part 81 and the second thick plate connecting part 82 expands thermally. Pressed by

Here, the stack connection part 80 of this embodiment is a V-shaped bent part in the thin plate connection part 83 when the stack connection part 80 is heated and thermally expanded by the combustion gas flowing into the gap between two adjacent cell stacks CS. 833 is more easily deformed than other parts. Therefore, when the thin plate connecting part 83 is pressed by the first thick plate connecting part 81 and the second thick plate connecting part 82 due to thermal expansion of the first thick plate connecting part 81 and the second thick plate connecting part 82, , the bent portion of the thin plate connecting portion 83 can be easily deformed. Specifically, when the first thick plate connecting portion 81 and the second thick plate connecting portion 82 thermally expand in mutually opposite directions in the circumferential direction DRc, the thin plate connecting portion 83 By being pressed by the plate connecting portion 82, as shown in FIG. 14, the bending angle θ is deformed to become smaller.

Thereby, the amount of deformation of the first thick plate connecting portion 81 due to thermal expansion and the amount of deforming of the second thick plate connecting portion 82 due to thermal expansion can be absorbed as the amount of deformation of the thin plate connecting portion 83. Therefore, the stress generated between the stack connection part 80 and the first cell stack CS1 due to thermal expansion of the stack connection part 80 and the stress generated between the stack connection part 80 and the second cell stack CS2 can be alleviated. Therefore, it is possible to suppress the occurrence of damage to the stack connection portion 80 and the connection portion between the stack connection portion 80 and the cell stack CS.

Furthermore, when performing the warm-up process, the bus bar connection section 90 connects to the gap between the cell stacks CS provided at one end and the other end of the plurality of cell stacks CS connected in series. The bus bar connection portion 90 may be heated and thermally expanded by the flowing combustion gas.

Here, as described above, the combustion gas blown out from the gas introduction hole 723 into the accommodation space BS flows toward the other side in the axial direction DRa. Thereby, the combustion gas blown out into the accommodation space BS can easily flow toward the bus bar connection portion 90. Therefore, in the busbar connection portion 90, the stack side connection portion 91 and the busbar side connection portion 92 are heated and thermally expand.

However, since the first connecting portion 911 is fixed to the terminal T of the cell stack CS by the fastening screw N, the stack side connecting portion 91 thermally expands away from the cell stack CS. Further, the bus bar side connecting portion 92 is fixed to the bus bar BB on the side opposite to the side to which the stack side connecting portion 91 is connected. Therefore, the busbar side connection part 92 provided between the stack side connection part 91 and the bus bar BB is pressed by the thermally expanding stack side connection part 91.

Here, in the busbar connection part 90 of this embodiment, when the busbar connection part 90 is heated and thermally expanded by the combustion gas flowing into the gap of the cell stack CS, the busbar side bending part 921 of the busbar side connection part 92 is It is easier to deform than other parts. Therefore, when the busbar side connection part 92 is pressed against the stack side connection part 91 due to thermal expansion of the stack side connection part 91, the bent portion of the busbar side connection part 92 can be easily deformed. Specifically, when the stack side connection portion 91 thermally expands toward the busbar side connection portion 92 in the circumferential direction DRc, the busbar side connection portion 92 is pressed by the stack side connection portion 91, so that the busbar side connection portion 92 is further bent.

Thereby, the amount of deformation of the stack-side connection portion 91 due to thermal expansion can be absorbed as the amount of deformation of the bus-bar side connection portion 92. Therefore, stress generated between the busbar connection portion 90 and the cell stack CS due to thermal expansion of the busbar connection portion 90 can be alleviated. Therefore, it is possible to suppress the occurrence of damage to the bus bar connection portion 90 and the connection portion between the bus bar connection portion 90 and the cell stack CS.

Furthermore, according to this embodiment, the following effects can be obtained.

(1) The thin plate connecting portion 83 of this embodiment is formed by being bent in a direction intersecting the circumferential direction DRc. One side in the circumferential direction DRc of the thin plate connecting part 83 is connected to the first supporting part 812 via a first thin plate side connecting part 813, and the other side in the circumferential direction DRc is connected to the first supporting part 812 via a second thin plate side connecting part 823. 2 support part 822.

According to this, when the thin plate connecting portion 83 is deformed by thermal expansion of the first support portion 812 and the second supporting portion 822 due to heating of the combustion gas, the thin plate connecting portion 83 is easily bent. Therefore, the amount of deformation of the first support portion 812 and the second support portion 822 due to thermal expansion of the first support portion 812 and the second support portion 822 can be absorbed as the amount of change in the amount of bending of the thin plate connection portion 83. can. Therefore, it is possible to further suppress the occurrence of damage to the stack connection portion 80 and the damage to the connection portion between the stack connection portion 80 and the cell stack CS.

(2) The thin plate connecting portion 83 of this embodiment is formed by bending a first plate portion 831 and a second plate portion 832 into a V shape so as to face each other. The thin plate connecting portion 83 is deformed so that the bending angle θ is reduced by being pressed by the thermally expanding first support portion 812 and second support portion 822.

According to this, the amount of deformation of the first support portion 812 and the second support portion 822 due to thermal expansion of the first support portion 812 and the second support portion 822 is absorbed as the amount of change in the bending angle θ of the thin plate connection portion 83. can be done. Therefore, it is possible to further suppress the occurrence of damage to the stack connection portion 80 and the damage to the connection portion between the stack connection portion 80 and the cell stack CS.

(3) In this embodiment, the thin plate connection portion 83, the first support portion 812, and the second support portion 822 are each formed separately from each other.

By the way, when assembling the thin plate connecting portion 83, the first supporting portion 812, and the second supporting portion 822 to the fuel cell module 1, the assembly positions of the thin plate connecting portion 83, the first supporting portion 812, and the second supporting portion 822 are It may shift from the designed position. However, by configuring the thin plate connection part 83, the first support part 812, and the second support part 822 separately, these thin plate connection part 83, the first support part 812, and the second support part 822 can be connected to the fuel cell module 1. The connection position can be adjusted during assembly. Therefore, even if the thin plate connecting portion 83, the first support portion 812, and the second support portion 822 deviate from the designed position, the deviation from the designed position can be easily absorbed.

(4) In this embodiment, the stack connection section 80 has a first thin plate side connection section 813 and a second thin plate side connection section 823 that sandwich the thin plate connection section 83. The first thin plate side connecting portion 813 is connected to the thin plate connecting portion 83 and has a first thin plate connecting surface 813a extending in the axial direction DRa.The second thin plate side connecting portion 823 is connected to the thin plate connecting portion 83 and has a first thin plate connecting surface 813a extending in the axial direction DRa. It has a second thin plate connection surface 823a extending to DRa. The thin plate connecting portion 83 extends along the axial direction DRa, which is the direction in which the first thin plate connecting surface 813a and the second thin plate connecting surface 823a extend.

According to this, when connecting the thin plate connection part 83 to the first support part 812 and the second support part 822, the connection position can be adjusted in the axial direction DRa. Therefore, even if the assembly positions of the first support part 812 and the second support part 822 are shifted in the axial direction DRa, the assembly position of the first support part 812 and the second support part 822 is The connection position of the thin plate connection portion 83 can be adjusted in the axial direction DRa.

(5) In the present embodiment, the size of the thin plate connecting portion 83 in the thickness direction is smaller than the size of the first support portion 812 and the second support portion 822 in the thickness direction.

According to this, compared to the case where the size of the thin plate connecting part 83 in the plate thickness direction is larger than the size of the first supporting part 812 and the second supporting part 822 in the plate thickness direction, the thin plate connecting part 83 When pressed by the first support part 812 and the second support part 822, it becomes easier to bend. Therefore, it is possible to further suppress the occurrence of damage to the stack connection portion 80 and the damage to the connection portion between the stack connection portion 80 and the cell stack CS.

Furthermore, as the size of the thin plate connecting portion 83 in the thickness direction is reduced, the electrical resistance value of the stack connecting portion 80 increases. It is larger than the thin plate connecting portion 83. Therefore, the electrical resistance value of the stack connection section 80 can be reduced by the first support section 812 and the second support section 822 which are relatively large in size in the thickness direction. Therefore, even if the electric resistance value increases by providing the thin plate connection part 83 having a relatively small size in the thickness direction in the stack connection part 80, the first support having a relatively large size in the thickness direction The portion 812 and the second support portion 822 can compensate for the increase.

(6) In this embodiment, each of the plurality of cell stacks CS has a terminal T connected to the stack connection portion 80 and having a terminal surface TS extending in a planar manner. The stack connecting portion 80 also includes a first thick plate connecting portion 81 having a first stack contacting surface 811a that extends in a planar manner and comes into contact with the terminal surface TS, and a second stack contacting portion 81 that extends in a planar shape and has a first stack contacting surface 811a that comes into contact with the terminal T. It has a second thick plate connection part 82 having a contact surface 821a.

According to this, the terminal surface TS, which extends in a planar manner, can be covered by the first stack abutting surface 811a and the second stack abutting surface 821a, which extend in a planar manner. Therefore, the heat generated when the cell C generates power is difficult to be released to the outside of the cell stack CS via the terminal surface TS. Therefore, the temperature of the plurality of cells C stacked in the cell stack CS can be easily adjusted.

(7) In this embodiment, the container 70 has the combustion gas passage 67 having the gas introduction hole 723 that guides the combustion gas to the storage space BS. The plurality of cell stacks CS are arranged radially around the combustion gas flow path 67. Further, the gas introduction hole 723 is formed at a position corresponding to a gap between adjacent cell stacks CS among the plurality of cell stacks CS.

According to this, the combustion gas blown out from the gas introduction hole 723 can flow into each of the gaps between the plurality of cell stacks CS, so that the temperature of each of the plurality of cell stacks CS can be heated to be uniform. .

(8) In this embodiment, the container 70 has a support part 76 that supports a plurality of cell stacks CS, and a base plate 75 to which the plurality of cell stacks CS supported by the support part 76 are attached. A gap is provided between the base plate 75 and the plurality of cell stacks CS, through which the combustion gas blown into the housing space BS flows.

According to this, the combustion gas blown into the housing space BS can flow between the base plate 75 and the plurality of cell stacks CS, so that the temperature of each of the plurality of cell stacks CS becomes uniform. be able to.

However, when performing the warm-up process, the base plate 75 may be heated by the combustion gas flowing between the base plate 75 and the plurality of cell stacks CS, and the base plate 75 may thermally expand and deform. For this reason, among the plurality of cell stacks CS attached to the base plate 75 via the support part 76, there is a possibility that the distance between adjacent cell stacks CS becomes large.

However, in the stack connection portion 80 of this embodiment, the V-shaped bent portion 833 in the thin plate connection portion 83 is more easily deformed than other portions. Therefore, even if the distance between adjacent cell stacks CS increases due to thermal expansion of the base plate 75, the V-shaped bent portion 833 deforms so that the bending angle θ becomes larger, and the change in the distance between the cell stacks CS is suppressed. This can be absorbed as the amount of deformation of the thin plate connecting portion 83.

This alleviates the stress generated between the stack connection portion 80 and the first cell stack CS1 and the stress generated between the stack connection portion 80 and the second cell stack CS2 due to thermal expansion of the base plate 75. can do. Therefore, it is possible to suppress the occurrence of damage to the stack connection portion 80 and the connection portion between the stack connection portion 80 and the cell stack CS.

Note that the effects shown in (1) to (5) above have been explained only with respect to the stack connection section 80, but the effects of the bus bar connection section 90, which can be achieved from a configuration similar to or equivalent to the stack connection section 80, are as follows. It can be obtained similarly to the stack connection part 80.

(First modification of the first embodiment)
In the first embodiment described above, the thin plate connecting portion 83 has the side facing the inner cylinder 72 where the first plate part 831 and the second plate part 832 are connected, and the side facing the outer cylinder 73 is open. Although an example of a V-shape has been described, the present invention is not limited to this. For example, the thin plate connecting portion 83 has a side facing the outer cylinder 73 where the first plate portion 831 and a second plate portion 832 are connected, and a side facing the inner cylinder 72 has an open V-shape. This may also be an example.

(Second modification of the first embodiment)
In the first embodiment described above, the thin plate connecting portion 83 is connected to the first thin plate connecting surface 813a and the second thin plate connecting surface 823a facing the outer cylinder 73 in the first thin plate side connecting portion 813 and the second thin plate side connecting portion 823. Although a fixed example has been described, the present invention is not limited to this. For example, the thin plate connecting portion 83 may be fixed to a portion of the first thin plate side connecting portion 813 and the second thin plate side connecting portion 823 that faces the inside of the battery container 71. Further, the thin plate connecting portion 83 may be fixed to a portion of the first thin plate side connecting portion 813 and the second thin plate side connecting portion 823 facing upward or downward in the axial direction DRa.

(Third modification of the first embodiment)
In the above-described first embodiment, an example has been described in which the first plate portion 831 is formed so that the size in the axial direction DRa on the plate surface is larger than the size in the direction perpendicular to the axial direction DRa. Not limited. Further, although an example has been described in which the size of the plate surface of the second plate portion 832 in the axial direction DRa is larger than the size in the direction perpendicular to the axial direction DRa, the present invention is not limited thereto. For example, the first plate portion 831 may be formed such that the size of the plate surface in the axial direction DRa is equal to or less than the size in the direction perpendicular to the axial direction DRa. Further, the second plate portion 832 may be formed such that the size of the plate surface in the axial direction DRa is equal to or less than the size in the direction perpendicular to the axial direction DRa.

(Fourth modification of the first embodiment)
In the first embodiment described above, the thin plate connecting portion 83 is formed of a thin plate member that is smaller in the thickness direction than the first thick plate connecting portion 81 and the second thick plate connecting portion 82, and the thin plate connecting portion 83 is 81 and the second thick plate connecting portion 82 have been described, but the present invention is not limited thereto. For example, if the thin plate connecting portion 83 is large enough to be easily deformed compared to other parts when the stack connecting portion 80 thermally expands, the size in the thickness direction is larger than that of the first thick plate connecting portion 81 and the first thick plate connecting portion 81. It may be formed of a thin plate member that is larger in the thickness direction than the two-thick plate connecting portion 82. Further, the thin plate connecting portion 83 has the same size in the thickness direction as the first thick plate connecting portion 81 and the second thick plate connecting portion 82, and the first thick plate connecting portion 81 and the second thick plate connecting portion It may be formed integrally with the plate connecting portion 82.

(Second embodiment)
Next, a second embodiment will be described with reference to FIGS. 15 to 19. In this embodiment, the shape of the stack connection portion 80 is different from that in the first embodiment. Other than this, the second embodiment is the same as the first embodiment. Therefore, in this embodiment, parts that are different from the first embodiment will be mainly described, and descriptions of parts similar to the first embodiment may be omitted.

The stack connection portion 80 of this embodiment is formed by bending one thin plate member 84 multiple times, as shown in FIGS. 15 and 16. Further, the stack connecting portion 80 has a substantially fan shape centered on the axis CL of the battery container 71, and extends along the radial direction DRr and the circumferential direction DRc. The stack connection portion 80 faces the gas introduction hole 723 in the radial direction DRr. Furthermore, the position of the gas introduction hole 723 in the present embodiment in the axial direction DRa overlaps with the position of the other end of the cell stack CS in the axial direction DRa.

Furthermore, the size of the stack connection portion 80 in the radial direction DRr is smaller than the size of the radial direction DRr of the cell stack CS. The position of the stack connection portion 80 in the radial direction DRr is included in the position where the cell stack CS is arranged. Specifically, the stack connecting portion 80 has an inner end in the radial direction DRr located outside in the radial direction DRr than an inner end in the radial direction DRr of the cell stack CS. The outer end of the stack connecting portion 80 in the radial direction DRr is positioned inside the radial direction DRr than the outer end of the cell stack CS in the radial direction DRr.

The stack connection part 80 of this embodiment includes a first thin plate connection part 841 connected to the first cell stack CS1, a first flat plate part 842 continuous to the first thin plate connection part 841, and a first thin plate part 842 in the first flat plate part 842. It has a first bent portion 843 extending opposite to the side to which the thin plate connecting portion 841 is connected.

The stack connecting portion 80 also includes a second thin plate connecting portion 844 connected to the second cell stack CS2, a second flat plate portion 845 continuous to the second thin plate connecting portion 844, and a second thin plate connection in the second flat plate portion 845. It has a second bent part 846 extending opposite to the side to which the part 844 is connected. Further, the stack connecting portion 80 has a bent portion 847 that is bent into a U-shape. The bent portion 847 is continuous with the first bent portion 843 and the second bent portion 846 between the first bent portion 843 and the second bent portion 846.

The first thin plate connecting portion 841, the first flat plate portion 842, the first bent portion 843, the second thin plate connecting portion 844, the second flat plate portion 845, the second bent portion 846, and the bent portion 847 are each formed integrally. , are formed to have the same size in the thickness direction. Further, a notch 848 is formed in the stack connecting portion 80 so as to penetrate in the thickness direction.

As shown in FIG. 15, the first thin plate connecting portion 841 is connected to one side of the first flat plate portion 842 in the circumferential direction DRc. The first thin plate connecting portion 841 is a portion connected to the terminal T of the first cell stack CS1, and extends along the direction in which the terminal plate surface TN of the terminal T extends. That is, the first thin plate connecting portion 841 extends in a planar manner along the axial direction DRa and the radial direction DRr. The first thin plate connecting portion 841 is fixed to the terminal T of the first cell stack CS1 by a fastening portion such as a bolt (not shown).

The first flat plate portion 842 is connected to the upper side of the first thin plate connecting portion 841 in the axial direction DRa, and extends in a planar manner along the radial direction DRr and the circumferential direction DRc. Furthermore, the first flat plate portion 842 is not in contact with the base plate 75 and is placed floating with respect to the base plate 75.

Here, as shown in FIG. 15, a portion of the upper wall 751 of the base plate 75 that faces the first flat plate portion 842 is referred to as a first flat plate opposing portion 7511. A gap is formed between the first flat plate part 842 and the first flat plate facing part 7511. As will be described later, combustion gas blown into the accommodation space BS from the gas introduction hole 723 flows through the gap formed between the first flat plate part 842 and the first flat plate facing part 7511. In other words, the first thin plate connecting portion 841 forms a gap between the first flat plate portion 842 and the first flat plate opposing portion 7511 to form the first gas flow path portion 85 through which combustion gas flows. The first flat plate facing portion 7511 functions as a stretched facing portion. The first thin plate connecting portion 841 functions as a flow path forming portion. The first flat plate part 842 covers a part of the upper side of the base plate 75 in the axial direction DRa via the first gas flow path part 85, which is a space between the first flat plate part 842 and the base plate 75.

That is, the first flat plate portion 842 has a lower surface in the axial direction DRa facing the first flat plate opposing portion 7511 of the base plate 75, an upper surface facing the accommodation space BS side, and a lower surface facing the first flat plate portion 7511 in the axial direction DRa. and the second cell stack CS2. As a result, when the fuel cell 10 generates power, the upper surface of the first flat plate portion 842 receives heat from the first cell stack CS1 and the second cell stack CS2.

The first bent portion 843 is formed by bending the other end of the first flat plate portion 842 in the circumferential direction DRc. Specifically, the first bent portion 843 is formed by bending the other end of the first flat plate portion 842 in the circumferential direction DRc upward in the axial direction DRa. Note that the first bent portion 843 may be bent away from the upward direction of the axial direction DRa as long as it intersects the direction perpendicular to the plate surface of the first flat plate portion 842.

The second thin plate connecting portion 844 is connected to the other side of the second flat plate portion 845 in the circumferential direction DRc. The second thin plate connecting portion 844 is a portion connected to the terminal T of the second cell stack CS2, and extends along the direction in which the terminal plate surface TN of the terminal T extends. That is, the second thin plate connecting portion 844 extends in a planar manner along the axial direction DRa and the radial direction DRr. The second thin plate connecting portion 844 is fixed to the terminal T of the second cell stack CS2 by a fastening portion such as a bolt (not shown).

The second flat plate portion 845 is connected to the upper side of the second thin plate connecting portion 844 in the axial direction DRa, and extends in a planar manner along the radial direction DRr and the circumferential direction DRc. Further, the second flat plate portion 845 is not in contact with the base plate 75 and is placed in a floating state with respect to the base plate 75.

Here, as shown in FIG. 15, a portion of the base plate 75 that faces the second flat plate portion 845 is referred to as a second flat plate facing portion 7512. A gap is formed between the second flat plate portion 845 and the second flat plate facing portion 7512. As will be described later, combustion gas blown into the accommodation space BS from the gas introduction hole 723 flows through the gap formed between the second flat plate part 845 and the second flat plate facing part 7512. In other words, the second thin plate connecting portion 844 forms a gap between the second flat plate portion 845 and the second flat plate facing portion 7512 to form the second gas flow path portion 86 through which combustion gas flows. The second flat plate facing portion 7512 functions as a stretched facing portion. The second thin plate connecting portion 844 functions as a flow path forming portion. The second flat plate part 845 covers a part of the upper side of the base plate 75 in the axial direction DRa via the second gas flow path part 86 which is a space between the second flat plate part 845 and the base plate 75.

That is, the second flat plate portion 845 has a lower surface in the axial direction DRa facing the second flat plate opposing portion 7512 of the base plate 75, an upper surface facing the accommodation space BS side, and a lower surface facing the second flat plate opposing portion 7512 in the axial direction DRa. and the second cell stack CS2. As a result, when the fuel cell 10 generates power, the upper surface of the second flat plate portion 845 receives heat from the first cell stack CS1 and the second cell stack CS2. Further, the second flat plate portion 845 is arranged so that the installation position in the axial direction DRa is the same as that of the first flat plate portion 842. In this embodiment, the first flat plate part 842 and the second flat plate part 845 correspond to the extending part.

The second bent portion 846 is formed by bending one end of the second flat plate portion 845 in the circumferential direction DRc. Specifically, the second bent portion 846 is formed by bending an end portion of the second flat plate portion 845 on one side in the circumferential direction DRc upward in the axial direction DRa. Note that the second bent portion 846 may be bent away from the upward direction of the axial direction DRa as long as it intersects in a direction perpendicular to the plate surface of the second flat plate portion 845.

The bent portion 847 is a portion that connects the first bent portion 843 and the second bent portion 846, and is provided between the first bent portion 843 and the second bent portion 846. The bent portion 847 is formed by being bent so as to protrude upward in the axial direction DRa.

The bent portion 847 has a U-shaped cross-sectional view in the radial direction DRr, and one side in the circumferential direction DRc is connected to the first bent portion 843, and the other side is connected to the second bent portion 846. In other words, the first bent portion 843, the bent portion 847, and the second bent portion 846 are arranged in this order along the circumferential direction DRc. By providing the bent portion 847 between the first bent portion 843 and the second bent portion 846 in this manner, the first bent portion 843 and the second bent portion 846 are arranged to face each other in the circumferential direction DRc. be done. A predetermined gap S is formed between the first bent portion 843 and the second bent portion 846 in the circumferential direction DRc.

Note that the bent portion 847 may have a shape different from the U-shape when viewed in cross section in the radial direction DRr. For example, the bent portion 847 may have a V-shape or a U-shape when viewed in cross section in the radial direction DRr. Further, the bent portion 847 may be formed by being bent so as to protrude downward in the axial direction DRa.

In addition, in the stack connection portion 80 of this embodiment, a plurality of notches 848 are provided across the first flat plate portion 842, the first bent portion 843, the bent portion 847, the second bent portion 846, and the second flat plate portion 845. It is formed. The cutout portion 848 is formed along a direction perpendicular to the axial direction DRa and the radial direction DRr. Moreover, a plurality of notches 848 are formed at equal intervals along the radial direction DRr.

In the stack connecting portion 80 configured in this manner, when the stack connecting portion 80 is heated by introducing combustion gas into the gap between the first cell stack CS1 and the second cell stack CS2, the first flat plate portion 842 And the second flat plate portion 845 is heated. The first bent part 843 and the second bent part 846 are pressed by the first flat plate part 842 and the second flat plate part 845, which are heated by the combustion gas and thermally expand, so that the other parts of the stack connection part 80 It has a structure that can be easily deformed compared to . In this embodiment, the first bent part 843 and the second bent part 846 correspond to the bent part of the stress relaxation part, and the bent part 847 corresponds to the bent connection part.

Further, the first thin plate connecting portion 841 and the second thin plate connecting portion 844 extend along the direction in which the terminal plate surface TN of the terminal T to which they are connected extends. Therefore, as shown in FIG. 17, when assembling the stack connecting portion 80 between the first cell stack CS1 and the second cell stack CS2 along the radial direction DRr, the stack connecting portion 80 is attached to the first cell stack CS1 and the second cell stack CS2. It can be easily brought into contact with the terminal T of the 2-cell stack CS2. Specifically, the first thin plate connecting portion 841 and the second thin plate connecting portion 844 of the stack connecting portion 80 can be easily brought into contact with the terminal surfaces TS of the first cell stack CS1 and the second cell stack CS2, respectively.

Although not shown, the bus bar connection portion 90 in this embodiment may have the same shape as the stack connection portion 80 in this embodiment. That is, the bus bar connection part 90 in this embodiment may be formed by bending one thin plate member multiple times like the stack connection part 80 in this embodiment.

The stack connecting portion 80 configured in this manner is heated by the combustion gas flowing into the gaps between each of the plurality of cell stacks CS arranged at equal intervals in the circumferential direction DRc when the warm-up process is executed. be done. Specifically, the first flat plate part 842 and the second flat plate part 845 of the stack connection part 80 provided across the two cell stacks CS are heated by the combustion gas flowing into the gap between the two cell stacks CS adjacent to each other. . The first flat plate portion 842 and the second flat plate portion 845 extend in a planar manner along the radial direction DRr and the circumferential direction DRc, and cover a portion of the base plate 75 between the two cell stacks CS. .

Therefore, even if heat is released from the outermost cell C of the stacked cells C toward the heated first flat plate part 842 and second flat plate part 845, the heat is not released. Heat is blocked by the heated first flat plate part 842 and second flat plate part 845. Therefore, the heat emitted from the cell C becomes difficult to be emitted to the outside of the cell stack CS. Therefore, the amount of heat emitted from the outermost cell C among the plurality of stacked cells C and the amount of heat emitted from the cells C provided inside the outermost cell C are different. It is possible to suppress the difference from expanding.

Therefore, expansion of the temperature distribution between the outermost cell C among the plurality of stacked cells C and the cell C provided inside the outermost cell C is suppressed. can do.

Furthermore, when the stack connecting portion 80 is heated by the combustion gas flowing into the gap between two adjacent cell stacks CS during the warm-up process, the stack connecting portion 80 may thermally expand and deform. There is. However, in the stack connecting portion 80, the first thin plate connecting portion 841 is fixed to the terminal T of the first cell stack CS1, and the second thin plate connecting portion 844 is fixed to the terminal T of the second cell stack CS2. Therefore, in the stack connecting portion 80, the first flat plate portion 842 thermally expands so as to separate from the first cell stack CS1, and the second flat plate portion 845 thermally expands so as to separate from the second cell stack CS2. Therefore, the first bent part 843 connected to the first flat plate part 842 is pressed by the thermally expanding first flat plate part 842, and the second bent part 846 connected to the second flat plate part 845 is pressed by the thermally expanded second flat part 845. be done.

However, in the stack connecting portion 80 of the present embodiment, when the stack connecting portion 80 is heated and thermally expanded by the combustion gas flowing into the gap between two adjacent cell stacks CS, the first bent portion 843 and the second bent portion 846 is more easily deformed than other parts. Therefore, when the first bent part 843 and the second bent part 846 are pressed by the first flat part 842 and the second flat part 845 due to thermal expansion of the first flat part 842 and the second flat part 845, The first bent portion 843 and the second bent portion 846 can be easily deformed.

Specifically, when the stack connecting portion 80 is heated by combustion gas and the first flat plate portion 842 and the second flat plate portion 845 thermally expand in mutually opposite directions in the circumferential direction DRc, the first bent portion 843 and the second bent portion The portion 846 is pressed against the first flat plate portion 842 and the second flat plate portion 845. The first bent part 843 and the second bent part 846 are further arranged so that a predetermined gap S formed between the first bent part 843 and the second bent part 846 becomes smaller, as shown in FIG. Bend.

This allows the amount of deformation of the first flat plate portion 842 due to thermal expansion and the amount of deformation of the second flat portion 845 due to thermal expansion to be absorbed as the amount of deformation of the first bent portion 843 and the second bent portion 846. can. Therefore, stress generated between the stack connection part 80 and the cell stack CS due to thermal expansion of the stack connection part 80 can be alleviated. Therefore, it is possible to suppress the occurrence of damage to the stack connection portion 80 and the connection portion between the stack connection portion 80 and the cell stack CS.

Furthermore, according to this embodiment, the following effects can be obtained.

(1) In the stack connecting portion 80 of this embodiment, a cutout portion 848 is formed in the first bent portion 843 and the second bent portion 846 to penetrate in the thickness direction.

According to this, when the first bent part 843 and the second bent part 846 are pressed by the first flat part 842 and the second flat part 845, the first bent part 843 and the second bent part 846 are further bent. The portion 843 and the second bent portion 846 become easier to bend. Therefore, it is possible to further suppress the occurrence of damage to the stack connection portion 80 and the connection portion between the stack connection portion 80 and the cell stack CS.

In addition, in the stack connection part 80 of this embodiment, a notch part 848 is formed across the first flat part 842, the first bent part 843, the bent part 847, the second bent part 846, and the second flat part 845. . For this reason, it becomes easier to deform in the twisting direction compared to a configuration without the notch 848. Therefore, even if the positions of the first cell stack CS1 and the second cell stack CS2 to which the stack connection part 80 is assembled may deviate from the designed positions, the stack connection part 80 can be deformed in the torsional direction. 80 becomes easier to assemble.

(2) The stack connection part 80 of this embodiment includes a first thin plate connection part 841, a first flat plate part 842, a first bending part 843, a second thin plate connection part 844, a second flat plate part 845, and a second bending part 846. , and the bent portions 847 are integrally formed. Therefore, each of the first thin plate connecting portion 841, first flat plate portion 842, first bent portion 843, second thin plate connecting portion 844, second flat plate portion 845, second bent portion 846, and bent portion 847 is a separate body. The number of parts can be reduced compared to the case where the configuration is configured.

(3) The stack connection section 80 of this embodiment is provided between each of the plurality of cell stacks CS. The stack connecting portion 80 has a first gas flow path portion 85 through which combustion gas flows between the first flat plate portion 842 and the first flat plate opposing portion 7511, and the second flat plate portion 845 and the second flat plate opposing portion 7511. 7512, there is a second gas passage section 86 through which combustion gas flows.

In the fuel cell module 1 configured in this way, when the warm-up process is executed, the combustion gas blown out from the gas introduction hole 723 into the accommodation space BS is arranged at equal intervals in the circumferential direction DRc. It flows into the gaps between each of the plurality of cell stacks CS. Further, as described in the first embodiment, the combustion gas blown out from the gas introduction hole 723 into the accommodation space BS flows toward the other side in the axial direction DRa, as shown by the arrow in FIG. 21. The combustion gas blown out toward the other side in the axial direction DRa flows along the surface of the base plate 75 from the inside to the outside in the radial direction DRr.

Therefore, the combustion gas blown out into the housing space BS from the gas introduction hole 723 flows between the first gas flow path section 85 and the second gas flow path between the adjacent cell stacks CS, as shown by the arrow in FIG. The water flows through the passage 86 from the inside to the outside in the radial direction DRr. That is, the first gas flow path section 85 and the second gas flow path section 86 direct the combustion gas blown into the accommodation space BS from the gas introduction hole 723 into the accommodation space BS by bypassing the adjacent cell stacks CS. It flows from the inside to the outside in the radial direction DRr.

The combustion gas passes through the first gas flow path section 85 and the second gas flow path section 86 and is blown out toward the outside of the first gas flow path section 85 and the second gas flow path section 86 in the radial direction DRr. flows from the cell stack CS to the outside in the radial direction DRr. That is, the first gas flow path section 85 and the second gas flow path section 86 guide the combustion gas blown into the accommodation space BS from the gas introduction hole 723 to the outside of the cell stack CS in the radial direction DRr. Then, the combustion gas that has flowed from the cell stack CS to the outside in the radial direction DRr collides with the second inner wall 731 of the outer cylinder 73 and changes its flow direction, and flows along the wall surface of the second inner wall 731 to one side in the axial direction DRa. flowing towards the side. The first gas flow path section 85 and the second gas flow path section 86 function as a detour flow path section.

In this manner, the stack connection portion 80 of the present embodiment can prevent the combustion gas blown into the accommodation space BS from the gas introduction hole 723 from directly hitting the cell stack CS. In other words, the stack connection part 80 can circulate the combustion gas blown into the accommodation space BS into the accommodation space BS, bypassing the cell stack CS. According to this, since the high temperature combustion gas directly hits the cell stack CS, it is possible to suppress a partial temperature rise of the cell stack CS. This makes it difficult for temperature differences to occur between the plurality of cells C stacked and arranged in the cell stack CS. Therefore, it is possible to suppress a decrease in the performance of the cell stack CS due to an increase in the temperature difference between the plurality of cells C.

(4) The stack connection part 80 of this embodiment forms a gap between the first flat plate facing part 7511 and the first flat plate part 842 through which the combustion gas blown into the accommodation space BS flows, so that the first gas flow It has a first thin plate connection portion 841 forming a path portion 85 . In addition, the stack connecting portion 80 forms a gap between the second flat plate facing portion 7512 and the second flat plate portion 845 through which the combustion gas blown into the accommodation space BS flows, thereby forming a second gas flow path portion 86. A second thin plate connecting portion 844 is provided.

According to this, for example, the first gas flow path section 85 and the second gas flow path section 86 can be easily formed compared to the case where the first gas flow path section 85 and the second gas flow path section 86 are formed only by the shape of the stack connection section 80. A second gas flow path section 86 can be formed.

(5) In the stack connecting portion 80 of this embodiment, the first gas flow path portion 85 and the second gas flow path portion 86 guide combustion gas to the outside in the radial direction DRr from the cell stack CS.

According to this, it becomes easy to prevent the combustion gas blown into the accommodation space BS from the gas introduction hole 723 from directly hitting the cell stack CS.

(First modification of the second embodiment)
In the second embodiment described above, an example has been described in which the stack connecting portion 80 has one bent portion 847 and two bent portions 843 and 846 formed side by side, but the shape of the stack connecting portion 80 is limited to this. Not done. For example, the stack connection portion 80 may have a structure in which a plurality of portions corresponding to the bent portion 847 and portions corresponding to the bent portions 843 and 846 are arranged alternately in a wave shape.

(Second modification of the second embodiment)
In the second embodiment described above, the stack connecting portion 80 forms a gap between the first flat plate opposing portion 7511 and the first flat plate portion 842 through which the combustion gas blown into the accommodation space BS flows, and the first gas It has a first thin plate connection portion 841 that forms a flow path portion 85 . In addition, the stack connecting portion 80 forms a gap between the second flat plate facing portion 7512 and the second flat plate portion 845 through which the combustion gas blown into the accommodation space BS flows, thereby forming a second gas flow path portion 86. An example in which the second thin plate connecting portion 844 is provided has been described. However, the shape of the stack connection portion 80 is not limited to this.

For example, the stack connecting portion 80 may form the first gas flow path portion 85 and the second gas flow path portion 86 in a portion that does not face the first flat plate facing portion 7511 and the second flat plate facing portion 7512. .

(Third modification of second embodiment)
In the second embodiment described above, an example has been described in which the first gas flow path section 85 and the second gas flow path section 86 guide the combustion gas to the outside of the cell stack CS in the radial direction DRr, but the present invention is not limited to this.

For example, the first gas flow path section 85 and the second gas flow path section 86 may be configured to guide the combustion gas inside the cell stack CS in the radial direction DRr.

(Third embodiment)
Next, a third embodiment will be described with reference to FIG. 20. In this embodiment, the shape of the stack connection portion 80 is different from that in the second embodiment. Other than this, the second embodiment is the same as the second embodiment. Therefore, in this embodiment, parts that are different from the second embodiment will be mainly described, and descriptions of parts similar to the second embodiment may be omitted.

As shown in FIG. 20, the stack connection section 80 of this embodiment includes a first thin plate part 851 and a second thin plate part 852. The first thin plate portion 851 is a portion connected to the first cell stack CS1. The second thin plate portion 852 is a portion connected to the second cell stack CS2. The first thin plate portion 851 and the second thin plate portion 852 are configured separately from each other. However, the first thin plate portion 851 and the second thin plate portion 852 have approximately the same size in the thickness direction.

One end of the first thin plate portion 851 in the circumferential direction DRc is bent downward in the axial direction DRa, and the bent portion is connected to the terminal T of the first cell stack CS1. The first thin plate portion 851 corresponds to the first thin plate connecting portion 841 and the first flat plate portion 842 in the second embodiment. The other side of the first thin plate portion 851 in the circumferential direction DRc extends in a planar manner along the radial direction DRr and the circumferential direction DRc. The first thin plate portion 851 is formed with a notch 853 penetrating in the thickness direction at a portion extending planarly along the radial direction DRr and the circumferential direction DRc. A portion of the lower surface of the first thin plate portion 851 in the axial direction DRa is connected to the second thin plate portion 852 by, for example, welding.

The second thin plate portion 852 has a second thin plate flat portion 852a extending planarly along the radial direction DRr and the circumferential direction DRc on one side in the circumferential direction DRc, and is formed in a wave shape on the other side in the circumferential direction DRc. It has a second thin plate corrugated portion 852b. In the second thin plate portion 852, a portion of the upper surface of the second thin plate flat portion 852a in the axial direction DRa is connected to a portion of the lower surface of the first thin plate portion 851 in the axial direction DRa.

The second thin plate corrugated portion 852b includes a first thin plate bent portion 852c continuous to the second thin plate flat portion 852a, a first thin plate bent portion 852d continuous to the first thin plate bent portion 852c, and a second thin plate bent portion 852d continuous to the first thin plate bent portion 852d. It has a thin plate bent portion 852e. Further, the second thin plate corrugated portion 852b has a second bent portion 852f that is continuous with the second thin plate bent portion 852e. The first thin plate bent portion 852c, the first thin plate bent portion 852d, the second thin plate bent portion 852e, and the second bent portion 852f are arranged in this order along the circumferential direction DRc. The second thin plate portion 852 has cutout portions 854 penetrating in the thickness direction, including a second thin plate flat portion 852a, a first thin plate bent portion 852c, a first thin plate bent portion 852d, a second thin plate bent portion 852e, and a second thin plate bent portion 852e. It is formed across the two-folded portion 852f.

The first thin plate bent portion 852c is different from the first bent portion 843 in the second embodiment in the bending direction, but is otherwise similar to the first bent portion 843. The first thin plate bent portion 852d is different from the bent portion 847 in the second embodiment in the bending direction, but is otherwise similar to the bent portion 847. The second thin plate bent portion 852e is different from the second bent portion 846 in the second embodiment in the bending direction, but is otherwise similar to the second bent portion 846. In this embodiment, the first thin plate bent portion 852c and the second thin plate bent portion 852e correspond to the bent portion of the stress relaxation portion, and the first thin plate bent portion 852d corresponds to the bent connection portion.

Further, the other end of the second bent portion 852f in the circumferential direction DRc is connected to the terminal T of the second cell stack CS2. Further, the second bent portion 852f has the other side surface in the circumferential direction DRc extending along the direction in which the terminal plate surface TN of the terminal T extends. That is, the second bent portion 852f has a surface on the other side in the circumferential direction DRc extending in a planar manner along the axial direction DRa and the radial direction DRr. The second bent portion 852f is fixed to the terminal T of the second cell stack CS2 by a fastening portion such as a bolt (not shown).

Although not shown, the bus bar connection portion 90 in this embodiment may have the same shape as the stack connection portion 80 in this embodiment. That is, the bus bar connection section 90 in this embodiment is a combination of a thin plate-like member having a planarly extending portion and a thin plate-like member having a wave-like extending portion, like the stack connecting portion 80 in this embodiment. It may be configured by

The stack connecting portion 80 configured as described above is heated by the combustion gas flowing into the gaps between each of the plurality of cell stacks CS arranged at equal intervals in the circumferential direction DRc when the warm-up process is executed. The first thin plate portion 851 and the second thin plate portion 852 are heated.

Therefore, even if heat is released from the outermost cell C of the stacked cells C toward the heated first thin plate part 851 and second thin plate flat part 852a, it is not released. The generated heat is blocked by the heated first thin plate portion 851 and second thin plate flat portion 852a. Therefore, the heat emitted from the cell C becomes difficult to be emitted to the outside of the cell stack CS. Therefore, the amount of heat emitted from the outermost cell C among the plurality of stacked cells C and the amount of heat emitted from the cells C provided inside the outermost cell C are different. It is possible to suppress the difference from expanding.

Therefore, expansion of the temperature distribution between the outermost cell C among the plurality of stacked cells C and the cell C provided inside the outermost cell C is suppressed. can do.

In addition, the stack connecting portion 80 of this embodiment has a first thin plate bent portion 852c and a second thin plate bent portion when the stack connecting portion 80 is heated and thermally expanded by combustion gas flowing between two adjacent cell stacks CS. The portion 852e is more easily deformed than other portions. Therefore, as the first thin plate part 851 and the second thin plate flat part 852a expand thermally, the first thin plate bent part 852c and the second thin plate bent part 852e are pressed against the first thin plate part 851 and the second thin plate flat part 852a. When doing so, the first thin plate bent portion 852c and the second thin plate bent portion 852e can be easily deformed.

Specifically, when the stack connecting portion 80 is heated by combustion gas and the first thin plate portion 851 and the second thin plate flat portion 852a thermally expand in the circumferential direction DRc, the first thin plate bent portion 852c and the second thin plate bent portion 852e It is further bent so that the gap formed between it becomes smaller.

Thereby, the amount of deformation of the first thin plate portion 851 and the second thin plate flat portion 852a due to thermal expansion can be absorbed as the amount of deformation of the first thin plate bent portion 852c and the second thin plate bent portion 852e. Therefore, stress generated between the stack connection part 80 and the cell stack CS due to thermal expansion of the stack connection part 80 can be alleviated. Therefore, it is possible to suppress the occurrence of damage to the stack connection portion 80 and the connection portion between the stack connection portion 80 and the cell stack CS.

(Fourth embodiment)
Next, a fourth embodiment will be described with reference to FIG. 21. In this embodiment, the shape of the stack connection portion 80 is different from that in the second embodiment. Other than this, the second embodiment is the same as the second embodiment. Therefore, in this embodiment, parts that are different from the second embodiment will be mainly described, and descriptions of parts similar to the second embodiment may be omitted.

As shown in FIG. 21, the stack connection part 80 of this embodiment has a thin plate-like one side thin plate part 861 and a thin plate-like second side thin plate part 862. The one side thin plate portion 861 is a portion connected to the first cell stack CS1. The other thin plate portion 862 is a portion connected to the second cell stack CS2. The thin plate portion 861 on one side and the thin plate portion 862 on the other side are configured separately from each other. However, the thin plate portion 861 on one side and the thin plate portion 862 on the other side have substantially the same size in the thickness direction.

The one-side thin plate portion 861 has a one-side flat portion 861a that extends in a planar manner along the radial direction DRr and the circumferential direction DRc, and the one-side and other-side ends of the one-side flat portion 861a in the circumferential direction DRc are axial. It is bent upward in the direction DRa. That is, the one side thin plate portion 861 is bent and formed so as to protrude downward in the axial direction DRa.

One side thin plate part 861 has one side connection part 861b connected to terminal T of first cell stack CS1 on one side in circumferential direction DRc of one side flat part 861a, and has one side connection part 861b connected to terminal T of first cell stack CS1 on the other side in circumferential direction DRc. It has one side bent portion 861c. Further, the one-side thin plate portion 861 has a plate-shaped one-side bent plate portion 861d that is continuous with the one-side bent portion 861c and extends in the direction in which the one-side bent portion 861c is bent. A notch 861e penetrating in the thickness direction is formed in the one side flat portion 861a. The one side flat portion 861a has a substantially fan shape, and the size in the circumferential direction DRc decreases from the outside to the inside in the radial direction DRr. The one side flat portion 861a corresponds to the first flat plate portion 842 in the second embodiment.

The one-side connecting portion 861b is formed by being bent along the thickness direction of the one-side flat portion 861a. The one-side connecting portion 861b is a portion connected to the terminal T of the first cell stack CS1, and extends along the direction in which the terminal plate surface TN of the terminal T extends. That is, the one-side connecting portion 861b extends in a planar manner along the axial direction DRa and the radial direction DRr. The one side connecting portion 861b corresponds to the first thin plate connecting portion 841 in the second embodiment.

The one-side bent portion 861c is formed by being bent in the same direction as the one-side connecting portion 861b, which is along the thickness direction of the one-side flat portion 861a. Note that the one-side bent portion 861c may be bent away from the direction along the thickness direction of the one-side flat portion 861a.

The one side bent plate part 861d is a part to which the other side thin plate part 862 is connected. The one-side bent plate portion 861d extends in a planar manner along the direction in which the one-side bent portion 861c is bent (in the present embodiment, the axial direction DRa).

The other side thin plate portion 862 has the other side flat portion 862a that extends planarly along the radial direction DRr and the circumferential direction DRc, and the ends of the other side flat portion 862a on one side and the other side in the circumferential direction DRc are axially It is bent downward in the direction DRa. That is, the other side thin plate portion 862 is bent and formed so as to protrude upward in the axial direction DRa.

The other side thin plate part 862 has the other side connecting part 862b connected to the terminal T of the second cell stack CS2 on the other side in the circumferential direction DRc of the other side flat part 862a, and on one side in the circumferential direction DRc, It has the other side bent portion 862c. Further, the other side thin plate portion 862 has a plate-shaped other side bent plate portion 862d that is continuous with the other side bent portion 862c and extends in the direction in which the other side bent portion 862c is bent. A notch 862e penetrating in the thickness direction is formed in the other side flat portion 862a. The other side flat portion 862a has a substantially fan shape, and the size in the circumferential direction DRc decreases from the outside to the inside in the radial direction DRr. The other side flat portion 862a corresponds to the second flat plate portion 845 in the second embodiment.

The other side connecting portion 862b is formed by being bent along the thickness direction of the other side flat portion 862a. The other side connecting portion 862b is a portion connected to the terminal T of the second cell stack CS2, and extends along the direction in which the terminal plate surface TN of the terminal T extends. That is, the other side connecting portion 862b extends in a planar manner along the axial direction DRa and the radial direction DRr. The other side connecting portion 862b corresponds to the second thin plate connecting portion 844 in the second embodiment.

The other side bent portion 862c is formed by being bent in the same direction as the other side connecting portion 862b, which is along the thickness direction of the other side flat portion 862a. Further, the other side bent portion 862c is bent in the opposite direction to the direction in which the one side bent portion 861c is bent. That is, the one-side bent portion 861c and the other-side bent portion 862c are formed such that their bending directions are opposite to each other.

The other side bent plate portion 862d is formed by being bent in the same direction as the direction in which the other side connecting portion 862b is bent, which is along the thickness direction of the other side flat portion 862a. The other side bent plate part 862d is a part to which the one side bent plate part 861d of the one side thin plate part 861 is connected. The one side bent plate part 861d and the other side bent plate part 862d have plate surfaces facing each other connected to each other by, for example, welding or the like.

In the stack connecting portion 80 configured in this manner, one side flat portion 861a and the other side flat portion 862a are arranged side by side in the circumferential direction DRc. The one side bent plate part 861d that is continuous to the other side in the circumferential direction DRc of the one side flat part 861a and the other side bent plate part 862d that is continuous to one end of the other side plane part 862a in the circumferential direction DRc are mutually The plate surfaces of are connected. The one-side bent portion 861c and the other-side bent portion 862c are formed such that their bending directions are opposite to each other.

According to this, when the stack connection part 80 is heated by introducing combustion gas into the gap between the first cell stack CS1 and the second cell stack CS2, the one side flat part 861a and the other side flat part 861a The side plane portion 862a is heated. The one side bent portion 861c and the other side bent portion 862c are pressed by the one side flat portion 861a and the other side flat portion 862a, which are heated by the combustion gas and thermally expand, so that the other portions of the stack connection portion 80 It has a structure that can be easily deformed compared to . In this embodiment, the one side bent portion 861c and the other side bent portion 862c correspond to the bent portion of the stress relaxation portion.

Although not shown, the bus bar connection portion 90 in this embodiment may have the same shape as the stack connection portion 80 in this embodiment. That is, the bus bar connection part 90 in this embodiment may be configured by combining two plate-shaped members with both ends bent, like the stack connection part 80 in this embodiment.

When the stack connecting portion 80 is warmed up, the one side flat portion 861a is caused by the combustion gas flowing into the gaps between the plurality of cell stacks CS arranged at equal intervals in the circumferential direction DRc. And the other side flat portion 862a is heated.

For this reason, even if heat is released from the outermost cell C of the stacked cells C toward the heated one side flat part 861a and the other side flat part 862a, the heat is not released. Heat is blocked by the heated one-side flat portion 861a and the other-side flat portion 862a. Therefore, the heat emitted from the cell C becomes difficult to be emitted to the outside of the cell stack CS. Therefore, the amount of heat emitted from the outermost cell C among the plurality of stacked cells C and the amount of heat emitted from the cells C provided inside the outermost cell C are different. It is possible to suppress the difference from expanding.

Therefore, expansion of the temperature distribution between the outermost cell C among the plurality of stacked cells C and the cell C provided inside the outermost cell C is suppressed. can do.

Furthermore, when the stack connecting portion 80 is heated by the combustion gas flowing into the gap between two adjacent cell stacks CS during the warm-up process, the stack connecting portion 80 may thermally expand and deform. There is.

However, in the stack connecting portion 80 of this embodiment, when the stack connecting portion 80 is heated and thermally expanded by the combustion gas flowing into the gap between two adjacent cell stacks CS, the one side bent portion 861c and the other side bent portion 862c is more easily deformed than other parts. Therefore, when the one side bent portion 861c and the other side bent portion 862c are pressed by the one side flat portion 861a and the other side flat portion 862a due to thermal expansion of the one side flat portion 861a and the other side flat portion 862a, The one side bent portion 861c and the other side bent portion 862c can be easily deformed.

Specifically, when the stack connecting portion 80 is heated by combustion gas and the one side flat portion 861a and the other side flat portion 862a thermally expand in the circumferential direction DRc, the one side bent plate portion 861d and the other side bent plate portion 862d are pressed in opposite directions in the thickness direction of each other. Therefore, as illustrated in FIG. 22, the one-side bent portion 861c continuous with the one-side bent plate portion 861d is further bent toward one side in the thickness direction of the one-side bent plate portion 861d. Then, the other side bent portion 862c that continues to the other side bent plate portion 862d is further bent in the thickness direction of the other side bent plate portion 862d, and in the opposite direction to the direction in which the one side bent portion 861c is bent.

As a result, the amount of deformation of the one side flat portion 861a and the other side flat portion 862a due to thermal expansion of the one side flat portion 861a and the other side flat portion 862a is defined as the amount of deformation of the one side bent portion 861c and the other side bent portion 862c. It can be absorbed.

Therefore, the stress generated between the stack connection part 80 and the first cell stack CS1 due to thermal expansion of the stack connection part 80 and the stress generated between the stack connection part 80 and the second cell stack CS2 can be alleviated. Therefore, it is possible to suppress the occurrence of damage to the stack connection portion 80 and the connection portion between the stack connection portion 80 and the cell stack CS.

(Other embodiments)
Although typical embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and can be modified in various ways, for example, as described below.

In the second to fourth embodiments described above, an example has been described in which the stack connecting portion 80 has the notches 848, 853, 861e, and 862e, but the present invention is not limited thereto. For example, the stack connection portion 80 may have a configuration in which the cutouts 848, 853, 861e, and 862e are not formed.

In the embodiment described above, a portion of the stack connection portion 80 and the busbar connection portion 90 are bent. Although an example has been described in which the bent portion is more easily deformed than other portions when the stack connecting portion 80 and the bus bar connecting portion 90 thermally expand, the present invention is not limited thereto.

For example, a part of the stack connection part 80 and the bus bar connection part 90 may be made of a member having lower bending rigidity and shear rigidity than other parts. In this case, when the stack connection portion 80 and the bus bar connection portion 90 are heated and thermally expanded, the portions made of members having low bending rigidity and shear rigidity can be deformed.

In the above-described embodiment, an example will be described in which the parts of the stack connection part 80 and the bus bar connection part 90 that are connected to the terminal T extend in a planar manner, and the planarly extended parts cover a part of the terminal surface TS. However, it is not limited to this. For example, the portions of the stack connecting portion 80 and the bus bar connecting portion 90 that are connected to the terminal T extend linearly, and the stack connecting portion 80 and the bus bar connecting portion 90 do not cover a part of the terminal surface TS. You can.

In the embodiment described above, the gas introduction holes 723 are arranged radially around the combustion gas flow path 67 and are formed at positions corresponding to gaps between adjacent cell stacks among the plurality of cell stacks CS. has been described, but is not limited thereto.

For example, the gas introduction holes 723 may be arranged radially around the combustion gas flow path 67 and may be formed at positions facing a region where a plurality of cell stacks CS are provided.

In the embodiments described above, it goes without saying that the elements constituting the embodiments are not necessarily essential, except in cases where it is specifically specified that they are essential, or where they are clearly considered essential in principle.

In the above-described embodiment, an example has been described in which the stack connecting portion 80 and the bus bar connecting portion 90 are provided in the space below the space between the two cell stacks CS in the axial direction DRa in the accommodation space BS. It is not limited to this. For example, the stack connecting portion 80 and the bus bar connecting portion 90 may be provided in a space above the axial direction DRa from the space between the two cell stacks CS in the accommodation space BS.

In the embodiments described above, when numerical values such as the number, numerical value, amount, range, etc. of the constituent elements of the embodiment are mentioned, it is especially specified that it is essential, or it is clearly limited to a specific number in principle. It is not limited to that specific number, except in certain cases.

In the above-described embodiments, when referring to the shape, positional relationship, etc. of components, etc., we refer to the shape, positional relationship, etc., unless explicitly stated or in principle limited to a specific shape, positional relationship, etc. etc., but not limited to.

65 Warm-up burner 80 Conductive part 83 Stress relaxation part 812, 822 Stretching part CS Cell stack BS Accommodation space

Claims (16)

A fuel cell module,
a plurality of cell stacks (CS) in which a plurality of fuel cells (C) are stacked to output electrical energy through an electrochemical reaction between fuel gas and oxidant gas;
a bus bar (BB) provided between the plurality of cell stacks and for extracting electrical energy output from the fuel cell;
Among the plurality of cell stacks, the cell stack is provided straddling either between two adjacent cell stacks or between one of the two cell stacks and the bus bar, and a conductive part (80, 90) that electrically connects the cell stack or the one cell stack and the bus bar;
a housing (70) having a housing space (BS) that houses the plurality of cell stacks and the conductive part;
a warm-up burner (65) that generates combustion gas for warming up the plurality of cell stacks and heating the fuel cells, and blows it into the accommodation space;
The two cell stacks are arranged opposite to each other at a predetermined interval so that the combustion gas can be warmed up by flowing into a space including between the two cell stacks,
When the direction in which the two cell stacks are arranged is defined as the stack arrangement direction, the conductive part is a plate-shaped extension part (812, 822, 842, 845, 851, 852a, 861a, 862a, 912), and stress relaxation parts (83, 843, 846, 852c, 852e, 861c, 862c, 92). The stress relaxation part has a bent part (833, 921, 843, 846, 852c, 852e, 861c, 862c) in which a plate-shaped member is bent in a direction intersecting the stack arrangement direction,
The fuel cell module according to claim 1, wherein the bending section is connected to the extension section, and is pressed by the extension section and further bent when the extension section is heated and thermally expanded by the combustion gas. . The bent portion is formed by bending a plate-shaped first plate portion (831) and a plate-shaped second plate portion (832) into a V-shape so as to face each other, and the first plate portion When the angle formed by the first imaginary straight line (CL1) in the extending direction and the second imaginary straight line (CL2) in the extending direction of the second plate part is defined as the bending angle (θ), by being pressed by the extending part The fuel cell module according to claim 2, wherein the fuel cell module is deformed so that the bending angle becomes smaller. The stress relaxation part has a plurality of bending parts and a bending connection part (847, 852d) that connects the plurality of bending parts,
Two adjacent bent portions among the plurality of bent portions are arranged to face each other with a predetermined gap therebetween, and are further arranged such that the predetermined gap is reduced by being pressed by the extending portion. The fuel cell module according to claim 2, which is foldable. The conductive part has a plurality of the extending parts arranged in line in the stack arrangement direction,
The stress relaxation part is connected to at least one end of one side and the other side in the stack arrangement direction of each of the plurality of stretching parts, and the bent part bent in the thickness direction of the stretching part, It has a plate-shaped bent plate part (861d, 862d) that is connected to the bent part and extends in a direction in which the bent part is bent,
Among the plurality of extension parts, the bend plate part is connected to the bend part provided at one end in the stack arrangement direction of one of the two extension parts adjacent to each other; The bent plate portions connected to the bent portions provided at the other end in the stack arrangement direction of the other extending portion of the extending portions have their plate surfaces connected to each other,
3. The fuel cell module according to claim 2, wherein the two bent portions connected to each of the bent plate portions whose plate surfaces are connected to each other are formed such that their bending directions are opposite to each other. The fuel cell module according to any one of claims 3 to 5, wherein the bent portion is provided with a notch (848, 853, 854, 861e, 862e) that penetrates in the thickness direction of the bent portion. . The fuel cell module according to claim 6, wherein the stress relaxation section and the extension section are formed separately from each other. The conductive part has a first clamping part (813) and a second clamping part (823) that clamp the stress relaxation part,
The first clamping part has a first clamping surface (813a) to which the stress relaxation part is connected and extends in a predetermined direction,
The second clamping part has a second clamping surface (823a) to which the stress relaxation part is connected and extends in the predetermined direction,
The fuel cell module according to claim 7, wherein the bent portion extends along the predetermined direction. The fuel cell module according to claim 8, wherein the bent portion has a smaller size in the thickness direction than the extended portion. The fuel cell module according to claim 6, wherein the stress relaxation section and the extension section are integrally formed. Each of the plurality of cell stacks has a terminal (T) extending in a planar shape and having a terminal surface (TS) connected to the conductive part,
The fuel cell module according to claim 1, wherein the conductive portion has a stack contact portion (811, 821) having a stack contact surface (811a, 821a) that extends in a planar shape and contacts the terminal surface. The casing has a combustion gas flow path (67) having a gas introduction hole (723) that guides the combustion gas to the accommodation space,
The plurality of cell stacks are arranged radially around the combustion gas flow path,
The fuel cell module according to claim 1, wherein the gas introduction hole is formed at a position corresponding to a gap between adjacent cell stacks among the plurality of cell stacks. When the radial direction is a direction extending radially around the combustion gas flow path, the conductive portion directs the combustion gas blown out from the gas introduction hole into the accommodation space between the mutually adjacent cell stacks. The fuel cell module according to claim 12, further comprising detour flow path portions (85, 86) that bypass the mutually adjacent cell stacks by flowing from the inside to the outside in the radial direction. The casing has a stretched opposing portion (7511, 7512) that faces the stretched portion,
The conductive part includes a flow path forming part (841, 14. The fuel cell module according to claim 13, having: 844). The fuel cell module according to claim 13 or 14, wherein the detour flow path portion guides the combustion gas outward in the radial direction from the cell stack. The casing has a support part (76) that supports the plurality of cell stacks, and a base part (75) to which the plurality of cell stacks supported by the support part are attached,
The fuel cell module according to claim 1, wherein a gap is provided between the base portion and the plurality of cell stacks, through which the combustion gas blown into the accommodation space flows.

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