JP6738144B2 - Fuel cell cartridge, fuel cell module, and method for cooling fuel cell stack - Google Patents

Description

The present invention relates to a fuel cell cartridge, a fuel cell module including the fuel cell cartridge, and a method for cooling a fuel cell stack.

2. Description of the Related Art Fuel cells that generate electricity by chemically reacting a fuel gas with an oxidizing gas such as air are known. Among them, solid oxide fuel cells (SOFCs) use ceramics such as zirconia ceramics as an electrolyte. For example, hydrogen (H ₂ ) and carbon monoxide (CO), methane (CH ₄ ) are used. It is a fuel cell that is operated by using as a fuel a gas produced from a carbonaceous raw material such as a hydrocarbon gas such as, city gas, natural gas, petroleum, methanol, and coal gasification gas by a gasification facility. Such an SOFC has a high operating temperature of about 700 to 1000° C. in order to increase the ionic conductivity, and is known as a high-efficiency high-temperature fuel cell having a wide range of applications (see Patent Documents 1 to 3).

A combined power generation system has been developed in which such an SOFC is combined with an internal combustion engine such as a micro gas turbine (hereinafter, referred to as “MGT”). In this MGT, the compressed air discharged from the compressor is supplied to the SOFC air electrode as an oxidizing gas, and the high temperature exhaust fuel gas discharged from the SOFC is supplied to the MGT combustor via a blower. Combustion is performed, and the combustion gas generated in the combustor is used to rotate the turbine of the MGT to drive the generator to rotate, thereby enabling power generation with high power generation efficiency.

Further, a triple combined cycle in which such an SOFC is combined with a GTCC (gas turbine combined cycle) is also under development. GTCC has a system that recovers the high exhaust gas energy of a gas turbine with an exhaust gas boiler and a steam turbine. There is a combined cycle that combines a gas turbine, an exhaust gas boiler, and a steam turbine to achieve high plant efficiency. Is possible. It is possible to achieve higher plant efficiency by further combining SOFC on the topping side (gas turbine side) of the GTCC to form a triple combined cycle.

JP, 1-320773, A JP, 2014-164903, A JP, 2014-192123, A

By the way, the SOFC is usually configured as a fuel cell module including a plurality of fuel cell cartridges in a casing containing a heat insulating material. In the fuel cell cartridge, a plurality of fuel cell cell stacks are arranged in parallel with each other with respect to the supply of the fuel gas and the oxidizing gas, and are assembled. It is configured by providing an oxidizing gas discharge header and a fuel supply header on the end side. By flowing the fuel from the other end side to the one end side inside the fuel cell stack, and the oxidizing gas from the one end side to the other end side around the fuel cell stack, respectively, by the reaction between the fuel and the oxidizing gas, Generate electricity.

In the SOFC, the temperature of the power generation part during power generation of each fuel cell stack is generally about 700 to 1000° C. from the viewpoint of performance and durability, but the power generation reaction of the fuel cell is an exothermic reaction. Therefore, if it is attempted to improve the power generation output, the temperature of each part of the cell stack rises while further inducing the temperature rise of the power generation part of the fuel cell stack, and the temperature of each component of the fuel cell cartridge rises. , It is necessary to consider not to damage each component.

Further, in each fuel cell stack of the fuel cell cartridge, heat is added by an electrochemical power generation reaction and the temperature of the power generation section rises, but since there is no power generation section at both ends in the longitudinal axis direction of the fuel cell stack. No fever occurs. In addition, the end portion of the fuel cell stack is likely to be radiated to the outside of the fuel cell cartridge. For this reason, the central portion in the longitudinal direction of the fuel cell stack tends to reach a relatively high temperature because a large amount of heat is generated during the power generation reaction and is not easily dissipated to the surroundings. Becomes

Further, in the fuel cell cartridge, since heat is dissipated to the periphery of the fuel cell cartridge, the fuel cell stack near the center in the parallel direction of the fuel cell cartridge has a fuel cell stack around the fuel cell cartridge. Compared with the above, heat dissipation is reduced, which is one of the factors causing the temperature difference between the fuel cell stacks.

As described above, the temperature distribution between the fuel cell stacks of the fuel cell cartridge tends to be uneven. On the other hand, in the electrochemical power generation reaction of the fuel cell, the internal resistance is lower in the region where the temperature is higher than in the region where the temperature is lower, and therefore the electrochemical reaction is more likely to proceed. Becomes larger, the electrochemical reaction decreases, and the amount of power generation decreases. That is, the power generation output can be increased by making the temperature distribution of each fuel cell stack of the fuel cell cartridge uniform.

Therefore, in order to prevent excessive temperature rise while improving the power generation output of the fuel cell cartridge, it is desired to make the temperature distribution in the fuel cell cartridge uniform, and to promote cooling of the power generation section of the fuel cell stack. However, it is necessary to keep the temperature within the upper limit of the above temperature range.

In Patent Document 3, a heat exchanger for air is installed in an upper part (upper part of a fuel cell cartridge) in a casing, and power-generating air (oxidizing gas) introduced from the outside by the heat exchanger for air and fuel are used. It is described that heat exchange is performed with the combustion gas (exhaust oxidizing gas) that has become a high temperature by reaction to preheat the power generation air (paragraph 0066, etc.).
From this, it can be recalled that the power generation part of the fuel cell stack is cooled by paying attention to the heat transfer of the oxidizing gas and the combustion gas.

That is, in the fuel cell cartridge, since the temperature of the oxidizing gas supplied to the fuel cell stack is lower than the temperature of the power generation section of the fuel cell stack, the oxidizing gas supplied to the power generation section of the fuel cell cartridge is , Plays a role of cooling the heat generation in the power generation reaction. Therefore, if the supply amount of this oxidizing gas is increased, it becomes possible to further cool the power generation unit, and it is possible to prevent an excessive temperature rise of the power generation unit. The output of the fuel cell cartridge can be increased until the upper limit is reached, and the system output and efficiency can be improved.

Therefore, as a means for increasing the supply amount of the oxidizing gas to the fuel cell stack, it is possible to configure a recirculation system in which exhausted oxidizing gas is recycled and returned to the oxidizing gas supply header of the fuel cell stack. Conceivable. However, in this case, auxiliary equipment such as a blower for recirculation is required, and new problems such as increased equipment cost, increased running cost, expanded space, and complicated operation/control occur. There is a demand for the development of a cooling technology for the power generation section that can be solved.

The present invention was devised in view of such problems, and promotes cooling of the power generation unit of the fuel cell stack while avoiding cost increase, space expansion, and operation/control complication as much as possible. It is an object of the present invention to provide a fuel cell cartridge, a fuel cell module including the same, and a method for cooling a fuel cell stack, which are capable of performing the above.

(1) In order to achieve the above object, a fuel cell cartridge of the present invention is provided with a fuel cell stack and an oxidizing gas supplied from an oxidizing gas supply pipe, which is disposed on one end side of the plurality of fuel cell stacks. An oxidizing gas supply header that supplies gas to the periphery of the fuel cell stack, and an oxidizing gas that is disposed on the other end side of the fuel cell stack and that discharges the oxidizing gas that has passed around the fuel cell stack. A fuel cell cartridge equipped with a gas discharge header and provided in a module container, wherein an internal space of the oxidizing gas discharge header is communicated with a space inside the module container and outside the fuel cell cartridge. By means of an ejector action using the communication hole and the flow of the oxidizing gas supplied from the oxidizing gas supply pipe to the oxidizing gas supply header, at least a part of the oxidizing gas in the module container is oxidized. It is characterized in that it is equipped with a peripheral fluid suction tool to be introduced into the gas supply header.

(2) The peripheral fluid suction tool is preferably provided between the oxidizing gas supply pipe and the oxidizing gas supply header.

(3) The oxidizing gas supply header is formed in the oxidizing gas supply duct to which the oxidizing gas supply pipe is connected and the oxidizing gas supply duct, and the oxidizing gas is supplied into the oxidizing gas supply duct. comprising a plurality of outlet holes for blowing out the sex gas, the oxidation gas discharged from the outlet hole, and a wall portion having a guide surface for guiding the oxidizing gas supply space leading to oxidation gas supply gap, said The peripheral fluid suction tool is preferably provided between the oxidizing gas supply pipe and the oxidizing gas supply duct.

(4) The oxidizing gas supply header is formed on the oxidizing gas supply duct to which the oxidizing gas supply pipe is connected and the oxidizing gas supply duct, and the oxidizing gas is supplied to the oxidizing gas supply duct. comprising a plurality of outlet holes for blowing out the sex gas, an oxidizing gas blown out from the outlet hole, and a wall portion having a guide surface for guiding the oxidizing gas supply space leading to oxidation gas supply gap, said The peripheral fluid suction tool is preferably provided between at least a part of the plurality of blowout holes and the oxidizing gas supply space.

(5) The wall having the guide surface may be provided with an inlet for introducing at least a part of the oxidizing gas in the module container into the oxidizing gas supply header. preferable.

(6) The peripheral fluid suction tool has a nozzle portion that injects the oxidizing gas supplied from the oxidizing gas supply pipe, and an opening that is provided on the downstream side of the nozzle portion and into which the injected oxidizing gas is introduced. And a suction chamber for sucking at least a part of the oxidizing gas in the module container at the opening of the diffuser portion.

(7) The fuel cell module of the present invention is characterized in that a plurality of fuel cell cartridges according to any one of (1) to (6) are provided in a module container.

(8) In the method for cooling a fuel cell stack of the present invention, a fuel cell stack and an oxidizing gas supplied from an oxidizing gas supply pipe, which is disposed at one end side of the plurality of fuel cell stacks, is used as the fuel. An oxidizing gas supply header to be supplied to the periphery of the battery cell stack, and an oxidizing gas discharge header that is disposed on the other end side of the fuel cell stack and discharges the oxidizing gas that has passed around the fuel cell stack. And a method for cooling the fuel cell stack, wherein a part of the oxidizing gas inside the oxidizing gas discharge header is provided inside the module container. And is discharged to the space outside the fuel cell cartridge, and is discharged into the module container by an ejector action utilizing the flow of the oxidizing gas supplied from the oxidizing gas supply pipe to the oxidizing gas supply header. At least a part of the oxidizing gas is introduced into the oxidizing gas supply header to increase the flow rate of the oxidizing gas supplied to the fuel cell stack.

According to the present invention, a part of the oxidizing gas inside the oxidizing gas discharge header is discharged into the module container, and the flow of the oxidizing gas supplied from the oxidizing gas supply pipe to the oxidizing gas supply header is used. By the ejector action to do, since the oxidizing gas discharged into the module container is introduced into the oxidizing gas supply header, the amount of the oxidizing gas supplied to the periphery of the fuel cell stack can be increased, Cooling of the power generation part of the fuel cell stack can be promoted by the oxidizing gas.

It is an exploded perspective view showing the fuel cell module concerning a 1st and 2nd embodiment. It is sectional drawing which shows the fuel cell cartridge which concerns on 1st, 2nd embodiment. It is sectional drawing which shows the fuel cell stack which concerns on 1st, 2nd embodiment. FIG. 3 is a schematic cross-sectional view of a fuel cell module for explaining the concept of a method for cooling the fuel cell stack of the fuel cell cartridge according to the first and second embodiments. It is a perspective view which shows the oxidizing gas supply header which concerns on 1st Embodiment. It is a figure which shows the oxidizing gas supply header which concerns on 1st Embodiment, (a) is the top view, (b) is the side view [a part is DD sectional view taken on the line of FIG. 6(a)]. , (C) is a lateral view thereof [a sectional view taken along the line CC in FIG. 6(a)]. It is a perspective view which shows the oxidizing gas discharge header which concerns on 1st, 2nd embodiment. It is a perspective view which shows the oxidizing gas supply header which concerns on 2nd Embodiment. It is a figure which shows the oxidizing gas supply header which concerns on 2nd Embodiment, (a) is the top view, (b) is the side view. It is sectional drawing which shows the oxidizing gas supply header which concerns on 2nd Embodiment, (a) is a sectional view on the AA arrow of FIG. 9(a), (b) is a BB arrow of FIG. 9(a). FIG.

Embodiments of the present invention will be described below with reference to the drawings.
Here, two embodiments of the first embodiment and the second embodiment will be described. First, referring to FIGS. 1 to 3, a fuel cell module, a fuel cell cartridge, and a fuel cell which are common to the respective embodiments. The stack will be described. After that, the concept of the cooling method of the fuel cell stack of the fuel cell cartridge common to the first and second embodiments will be described with reference to FIGS. 2 and 4, and further with reference to FIGS. The configuration of the oxidizing gas supply header according to the first embodiment and the configuration of the oxidizing gas supply header according to the second embodiment will be described with reference to FIGS. 8 to 10. In the description of the configuration common to the first embodiment and the second embodiment, each embodiment will be simply referred to as an embodiment without distinction.
Further, in the following, regarding a solid oxide fuel cell (SOFC), a fuel cell is referred to as an SOFC cell, a fuel cell stack is referred to as a cell stack, a fuel cell cartridge is referred to as an SOFC cartridge, and a fuel cell module is referred to as an SOFC module. ..

[1. SOFC Module, SOFC Cartridge, Cell Stack of Each Embodiment]
In the following, for convenience of description, the positional relationship between the respective constituent elements is specified using the expressions “upper” and “lower” with reference to the paper surface, but this need not always be the case with respect to the vertical direction. For example, the upward direction on the paper surface may correspond to the downward direction on the vertical direction. Further, the vertical direction on the paper surface may correspond to the horizontal direction perpendicular to the vertical direction.
Further, in the following, a cylindrical type is described as an example of a cell stack of a solid oxide fuel cell (SOFC), but the cell stack is not necessarily limited to this, and may be a flat cell stack, for example.

(Structure of cylindrical cell stack)
First, the cylindrical cell stack according to each embodiment will be described with reference to FIG. Here, FIG. 3 illustrates one aspect of the cell stack according to each embodiment. The cell stack 101 includes a cylindrical base tube 103, a plurality of fuel battery cells 105 formed on the outer peripheral surface of the base tube 103, and an interconnector 107 formed between adjacent fuel battery cells 105. The fuel cell 105 is formed by stacking a fuel electrode 109, a solid electrolyte 111, and an air electrode 113. In addition, the cell stack 101 is connected to the air electrode 113 of the fuel cell 105 formed at the end in the axial direction of the base tube 103 among the plurality of fuel cell 105 formed on the outer peripheral surface of the base tube 103. It has a lead film 115 electrically connected via a connector 107.

(Explanation of materials and functions of each component of the cell stack)
The substrate tube 103 is made of a porous material, and is, for example, CaO-stabilized ZrO ₂ (CSZ), Y ₂ O ₃ -stabilized ZrO ₂ (YSZ), or MgAl ₂ O ₄ . The base tube 103 supports the fuel cell unit 105, the interconnector 107, and the lead film 115, and allows the fuel gas supplied to the inner peripheral surface of the base tube 103 to pass through the pores of the base tube 103. Is diffused to the fuel electrode 109 formed on the outer peripheral surface of the.

The fuel electrode 109 is composed of an oxide of a composite material of Ni and a zirconia-based electrolyte material, and for example, Ni/YSZ is used. In this case, in the fuel electrode 109, Ni, which is a component of the fuel electrode 109, has a catalytic action on the fuel gas. This catalytic action causes a fuel gas supplied through the base pipe 103, for example, a mixed gas of methane (CH ₄ ) and steam to react with each other and reform it into hydrogen (H ₂ ) and carbon monoxide (CO). It is a thing. Further, the fuel electrode 109 interfaces hydrogen (H ₂ ) and carbon monoxide (CO) obtained by reforming and oxygen ions (O ²⁻ ) supplied via the solid electrolyte 111 with the solid electrolyte 111. It is an electrochemical reaction in the vicinity to generate water (H ₂ O) and carbon dioxide (CO ₂ ). At this time, the fuel cell unit 105 generates electricity by electrons emitted from oxygen ions.

The solid electrolyte 111 is mainly made of YSZ, which has gas-tightness that makes it difficult for gas to pass through and high oxygen ion conductivity at high temperatures. The solid electrolyte 111 moves oxygen ions (O ²⁻ ) generated at the air electrode to the fuel electrode 109.
The air electrode 113 is made of, for example, LaSrMnO ₃ -based oxide or LaCoO ₃ -based oxide. The air electrode 113 dissociates oxygen in the oxidizing gas such as air supplied near the interface with the solid electrolyte 111 to generate oxygen ions (O ²⁻ ).

The interconnector 107 is composed of a conductive perovskite-type oxide represented by M _1-x L _x TiO ₃ (M is an alkaline earth metal element, L is a lanthanoid element) such as SrTiO ₃ system, and is composed of a fuel gas and an oxide. It is a dense film so that it does not mix with the volatile gas. Further, the interconnector 107 has stable electric conductivity in both the oxidizing atmosphere and the reducing atmosphere. This interconnector 107 electrically connects the air electrode 113 of one fuel battery cell 105 and the fuel electrode 111 of the other fuel battery cell 105 in the adjacent fuel battery cells 105 so that adjacent fuel battery cells 105 are connected to each other. Are connected in series.

Since the lead film 115 needs to have electronic conductivity and has a thermal expansion coefficient close to that of other materials forming the cell stack 101, Ni such as Ni/YSZ and a zirconia-based electrolyte material are required. Composed of composite material. The lead film 115 guides the DC power generated by the plurality of fuel cells 105 connected in series by the interconnector to the vicinity of the end of the cell stack 101.

(Description of SOFC module structure and function of each element)
Next, the SOFC module and the SOFC cartridge according to each embodiment will be described with reference to FIGS. 1 and 2.
As shown in FIG. 1, the SOFC module 201 includes, for example, a plurality of SOFC cartridges 203 and a pressure container (module container) 205 that houses the plurality of SOFC cartridges 203. Further, the SOFC module 201 has a fuel gas supply main pipe 207 and a plurality of fuel gas supply branch pipes 207a. Further, the SOFC module 201 has a fuel gas discharge main pipe 209 and a plurality of fuel gas discharge branch pipes 209a. Further, the SOFC module 201 has an oxidizing gas supply main pipe (not shown) and an oxidizing gas supply branch pipe 220a. Although only the end portion of the oxidizing gas supply branch pipe 220a is shown in FIG. 2, here, the oxidizing gas supply pipe 220 is a combination of the oxidizing gas supply main pipe and the oxidizing gas supply branch pipe 220a. Further, the SOFC module 201 has an oxidizing gas discharge main pipe (not shown) and a plurality of oxidizing gas discharge branch pipes (oxidizing gas discharge pipe of the present invention) 222a. Although only the end of the oxidizing gas discharge branch pipe 222a is shown in FIG. 2, here, a combination of the oxidizing gas discharge main pipe and the oxidizing gas discharge branch pipe 222 is referred to as an oxidizing gas discharge pipe 222.

The fuel gas supply main pipe 207 is provided outside the pressure vessel 205, and is connected to a fuel gas supply unit that supplies a fuel gas of a predetermined gas composition and a predetermined flow rate as indicated by an arrow G, corresponding to the power generation amount of the SOFC module 201. At the same time, it is connected to a plurality of fuel gas supply branch pipes 207a. The fuel gas supply main pipe 207 is for guiding the fuel gas at a predetermined flow rate, which is supplied from the above-mentioned fuel gas supply unit, into a plurality of fuel gas supply branch pipes 207a in a branched manner. Further, the fuel gas supply branch pipe 207 a is connected to the fuel gas supply main pipe 207 and also to the plurality of SOFC cartridges 203. The fuel gas supply branch pipe 207a guides the fuel gas supplied from the fuel gas supply main pipe 207 to the plurality of SOFC cartridges 203 at substantially equal flow rates, and makes the power generation performances of the plurality of SOFC cartridges 203 substantially uniform. ..

The fuel gas discharge branch pipe 209a is connected to the plurality of SOFC cartridges 203 and is also connected to the fuel gas discharge main pipe 209. The fuel gas supply branch pipe 209 a guides the exhaust fuel gas discharged from the SOFC cartridge 203 to the fuel gas discharge main pipe 209. Further, the fuel gas discharge main pipe 209 is connected to the plurality of fuel gas supply branch pipes 209 a, and a part thereof is arranged outside the pressure vessel 205. The fuel gas discharge main pipe 209 guides the exhaust fuel gas, which is discharged from the fuel gas discharge branch pipe 209a at a substantially uniform flow rate, to the outside of the pressure vessel 205.

Since the pressure vessel 205 is operated at an internal pressure of 0.1 MPa to about 1 MPa and an internal temperature of about atmospheric temperature to about 550° C., it has durability and corrosion resistance to an oxidizing agent such as oxygen contained in the oxidizing gas. The possessed material is used. For example, a stainless steel material such as SUS304 is suitable.

Here, in each embodiment, a mode in which a plurality of SOFC cartridges 203 are collected and housed in the pressure container 205 is described, but the embodiment is not limited to this. It may be configured to be housed in the container 205.

As shown in FIG. 2, the SOFC cartridge 203 includes a plurality of cell stacks 101, a power generation unit 215, a fuel gas supply header (fuel gas supply chamber) 217, a fuel gas discharge header (fuel gas discharge chamber) 219, and an oxidizer. An oxidizing gas supply header (oxidizing gas supply chamber) 221 and an oxidizing gas discharge header (oxidizing gas discharge chamber) 223 are provided. A plurality of cell stacks 101 are assembled and installed in parallel. The SOFC cartridge 203 also includes an upper tube plate 225a, a lower tube plate 225b, an upper heat insulator 227a, and a lower heat insulator 227b. In each embodiment, the SOFC cartridge 203 has a fuel gas supply header 217, a fuel gas discharge header 219, an oxidizing gas supply header 221, and an oxidizing gas discharge header 223 arranged as shown in FIG. The fuel gas and the oxidizing gas have a structure in which they flow inside and outside the cell stack 101 so as to face each other. However, this is not always necessary. For example, the fuel gas and the oxidizing gas flow inside and outside the cell stack 101 in parallel. Alternatively, the oxidizing gas may flow in a direction orthogonal to the longitudinal direction of the cell stack.

The power generation unit 215 is a region formed between the upper heat insulator 227a and the lower heat insulator 227b. The power generation unit 215 is a region where the fuel cells 105 of the cell stack 101 are arranged and which electrochemically reacts a fuel gas and an oxidizing gas to generate power. Further, an intermediate portion of the power generation unit 215 in the longitudinal direction of the cell stack 101 serves as a power generation unit for generating power, and the temperature near the central portion in the longitudinal direction of the cell stack 101 is steadily operated by the heat generated by the power generation of the SOFC module 201. At times, it becomes a high temperature atmosphere of about 700 to 1000°C.

The fuel gas supply header 217 is a region surrounded by the upper casing 229a of the SOFC cartridge 203 and the upper tube sheet 225a. Further, the fuel gas supply header 217 is communicated with the fuel gas supply branch pipe 207a through a fuel gas supply hole 231a provided in the upper casing 229a. Further, in the fuel gas supply header 217, one end of the cell stack 101 is arranged such that the inside of the base pipe 105 of the cell stack 101 is open to the fuel gas discharge header 219. The fuel gas supply header 217 guides the fuel gas supplied from the fuel gas supply branch pipe 207a through the fuel gas supply holes 231a into the base pipes 105 of the plurality of cell stacks 101 at a substantially uniform flow rate, thereby providing a plurality of fuel gas. The power generation performance of the cell stack 101 is made substantially uniform.

The fuel gas discharge header 219 is an area surrounded by the lower casing 229b and the lower tube plate 225b of the SOFC cartridge 203. Further, the fuel gas discharge header 219 is communicated with the fuel gas discharge branch pipe 209a through a fuel gas discharge hole 231b provided in the lower casing 229b. Further, in the fuel gas discharge header 219, the other end of the cell stack 101 is arranged such that the inside of the base pipe 105 of the cell stack 101 is open to the fuel gas discharge header 219. The fuel gas discharge header 219 collects the exhaust fuel gas that passes through the insides of the base pipes 105 of the plurality of cell stacks 101 and is supplied to the fuel gas discharge header 219, and the fuel gas discharge holes 231b are used to collect the fuel gas. It leads to the discharge branch pipe 209a.

Corresponding to the power generation amount of the SOFC module 201, an oxidizing gas having a predetermined gas composition and a predetermined flow rate is branched into an oxidizing gas supply branch pipe 220a and supplied to a plurality of SOFC cartridges 203. The oxidizing gas supply header 221 is an area surrounded by the lower casing 229b, the lower tube plate 225b, and the lower support 227b of the SOFC cartridge 203. In addition, the oxidizing gas supply header 221 is connected to the oxidizing gas supply branch pipe of the oxidizing gas supply pipe 220 through the oxidizing gas supply hole 233a provided in the lower casing 229b. In the oxidizing gas supply header 221, a predetermined flow rate of the oxidizing gas supplied from the oxidizing gas supply pipe 220 through the oxidizing gas supply hole 233a is passed through an oxidizing gas supply gap 235a, which will be described later, and the power generation unit 215. Will lead to.

The oxidizing gas discharge header 223 is an area surrounded by the upper casing 229a, the upper tube sheet 225a, and the upper support 227a of the SOFC cartridge 203. Further, the oxidizing gas discharge header 223 is communicated with the oxidizing gas discharge branch pipe 222a of the oxidizing gas discharge pipe 222 through the oxidizing gas discharge hole 233b provided in the upper casing 229a. The oxidizing gas exhaust header 223 oxidizes exhaust oxidizing gas supplied from the power generation unit 215 to the fuel gas exhaust header 223 via the oxidizing gas exhaust gap 235b described later via the oxidizing gas exhaust hole 233b. The exhaust gas exhaust pipe 222 is guided to the oxidizing gas exhaust branch pipe 222a.

The upper tube plate 225a is arranged such that the upper tube plate 225a and the upper plate of the upper casing 229a are substantially parallel to the upper plate 225a between the upper plate of the upper casing 229a and the upper heat insulator 227a. It is fixed to the side plate. The upper tube sheet 225a has a plurality of holes corresponding to the number of cell stacks 101 provided in the SOFC cartridge 203, and the cell stacks 101 are inserted into the holes, respectively. The upper tube sheet 225a hermetically supports one end portion of the plurality of cell stacks 101 via one or both of a seal member and an adhesive member, and at the same time, a fuel gas supply header 217 and an oxidizing gas discharge header 223. It isolates and.

The lower tube plate 225b is provided on a side plate of the lower casing 229b so that the lower tube plate 225b, the bottom plate of the lower casing 229b, and the lower heat insulator 227b are substantially parallel to each other between the bottom plate of the lower casing 229b and the lower heat insulator 227b. It is fixed. Further, the lower tube sheet 225b has a plurality of holes corresponding to the number of the cell stacks 101 provided in the SOFC cartridge 203, and the cell stacks 101 are inserted into the holes, respectively. The lower tube sheet 225b hermetically supports the other ends of the plurality of cell stacks 101 via one or both of the seal member and the adhesive member, and also the fuel gas discharge header 219 and the oxidizing gas supply header 221. It isolates and.

The upper heat insulator 227a is arranged at the lower end of the upper casing 229a so that the upper heat insulator 227a, the top plate of the upper casing 229a, and the upper tube plate 225a are substantially parallel to each other, and is fixed to the side plate of the upper casing 227a. There is. Further, the upper heat insulator 227a is provided with a plurality of holes corresponding to the number of cell stacks 101 included in the SOFC cartridge 203. The diameter of this hole is set larger than the outer diameter of the cell stack 101. The upper heat insulator 227a has an oxidizing gas discharge gap 235b formed between the inner surface of this hole and the outer surface of the cell stack 101 inserted through the upper heat insulator 227a.

The upper heat insulator 227a partitions the power generation unit 215 and the oxidizing gas discharge header 223, and the atmosphere around the upper tube sheet 225a is heated to lower the strength or corrode due to the oxidizing agent contained in the oxidizing gas. Suppress increasing. The upper tube sheet 225a and the like are made of a metal material having high temperature durability such as Inconel, but when the upper tube sheet 225a and the like are exposed to the high temperature in the power generation unit 215, the temperature difference in the upper tube sheet 225a and the like becomes large. It prevents thermal deformation. In addition, the upper heat insulator 227a guides the exhaust oxidizing gas that has passed through the power generation unit 215 and has been exposed to high temperature to the oxidizing gas exhaust header 223 through the oxidizing gas exhaust gap 235b.

According to the present embodiment, the structure of the SOFC cartridge 203 described above allows the fuel gas and the oxidizing gas to flow inside and outside the cell stack 101 so as to face each other. As a result, the exhausted oxidizing gas exchanges heat with the fuel gas supplied to the power generation unit 105 through the inside of the base tube 105, and the upper tube sheet 225a made of a metal material causes buckling or the like. It is cooled to a temperature at which it is not deformed and supplied to the oxidizing gas discharge header 223. Further, the fuel gas is heated by heat exchange with the exhaust oxidizing gas discharged from the power generation unit 215 and is supplied to the power generation unit 215. As a result, the fuel gas preheated to a temperature suitable for power generation can be supplied to the power generation unit 215 without using a heater or the like.

The lower heat insulator 227b is arranged on the upper end of the lower casing 229b so that the lower heat insulator 227b, the bottom plate of the lower casing 229b, and the lower tube plate 225b are substantially parallel to each other, and is fixed to the side plate of the upper casing 227a. .. Further, the lower heat insulator 227b is provided with a plurality of holes corresponding to the number of cell stacks 101 included in the SOFC cartridge 203. The diameter of this hole is set larger than the outer diameter of the cell stack 101. The lower heat insulator 227b has an oxidizing gas supply gap 235a formed between the inner surface of this hole and the outer surface of the cell stack 101 inserted through the lower heat insulator 227b.

The lower heat insulator 227b partitions the power generation unit 215 and the oxidizing gas supply header 221, and the atmosphere around the lower tube sheet 225b is heated to a high temperature, and strength is reduced and corrosion due to an oxidizing agent contained in the oxidizing gas is caused. Suppress increasing. The lower tube sheet 225b and the like are made of a metal material having high temperature durability such as Inconel. However, when the lower tube sheet 225b and the like are exposed to high temperature, the temperature difference in the lower tube sheet 225b and the like becomes large, and thus the lower tube sheet 225b and the like are thermally deformed. To prevent. Further, the lower heat insulator 227b guides the oxidizing gas supplied to the oxidizing gas supply header 233 to the power generation unit 215 through the oxidizing gas supply gap 235a.

According to the present embodiment, the structure of the SOFC cartridge 203 described above allows the fuel gas and the oxidizing gas to flow inside and outside the cell stack 101 so as to face each other. As a result, the exhausted fuel gas that has passed through the power generation unit 215 through the inside of the base pipe 105 undergoes heat exchange with the oxidizing gas supplied to the power generation unit 215, and the lower tube sheet 225b made of a metal material. Are cooled to a temperature at which they do not deform such as buckling and are supplied to the fuel gas discharge header 219. Further, the oxidizing gas is heated by heat exchange with the exhaust fuel gas and is supplied to the power generation unit 215. As a result, the oxidizing gas heated to a temperature required for power generation can be supplied to the power generation unit 215 without using a heater or the like.

The DC power generated by the power generation unit 215 is led to the vicinity of the end of the cell stack 101 by the lead film 115 made of Ni/YSZ or the like provided in the plurality of fuel battery cells 105, and then the collector rod (not connected to the SOFC cartridge 203). Current is collected via a collector plate (not shown) in the drawing) and taken out to the outside of each SOFC cartridge 203. The electric power led to the outside of the SOFC cartridge 203 by the current collector is connected to the generated electric power of each SOFC cartridge 203 in a predetermined number of series and parallel, and is led to the outside of the SOFC module 201 to be illustrated. Not converted into a predetermined AC power by an inverter or the like and supplied to a power load.

[2. Method for cooling cell stack of SOFC cartridge of each embodiment]
Next, the concept of the cooling method of the cell stack in the SOFC cartridge of each embodiment will be described.

As shown in FIGS. 2 and 4, in the SOFC cartridge 203, the oxidizing gas discharge header 223 has a communication hole that communicates with the inside and outside of the oxidizing gas discharge header 223, separately from the oxidizing gas discharge hole 233b. 20 is provided in the vicinity of the opening joint portion 61 of the outer peripheral wall 67 of the short side portion 60S. The oxidizing gas supply header 221 communicates with the outside or inside of the oxidizing gas supply header 221 by utilizing the flow of the oxidizing gas supplied from the oxidizing gas supply pipe 220 to the oxidizing gas supply header 221. A peripheral fluid suction tool 10 for introducing the oxidizing gas (exhausted oxidizing gas) discharged into the pressure vessel 205 through the hole 20 into the oxidizing gas supply header 221 is provided.

The peripheral fluid suction tool 10 has a nozzle portion 11 for injecting the oxidizing gas supplied from the oxidizing gas supply pipe 220, and an inlet side provided on the downstream side of the nozzle portion 11 for introducing the injected oxidizing gas. It is a so-called ejector having a diffuser portion 12 having an opening 12a and a suction chamber 13 for sucking the oxidizing gas in the pressure vessel 205 into the opening 12a of the diffuser portion 12. The peripheral fluid suction tool 10 uses the pressure energy possessed by the oxidizing gas to be supplied and does not need to be powered by a pump or the like. The suction chamber 13 is provided with an inlet 13a for introducing an oxidizing gas, which is a fluid outside the SOFC cartridge 203, into the suction chamber 13. The term "outside" as used herein refers to a space that is an outer side space of the SOFC cartridge 203 surrounded by a heat insulating material and a casing, and a space that is an inner side of the pressure container 205. A specific example of the "external fluid" in the present embodiment is, for example, a gas in which a part of the oxidizing gas supplied to the SOFC cartridge 203 leaks into the exhausted oxidizing gas discharged, It is a gas that can be used as a recirculating oxidizing gas containing oxygen.

As shown in FIGS. 2 and 6, since the nozzle portion 11 of the peripheral fluid suction tool 10 is formed in a tapered shape in which the flow passage cross-sectional area gradually decreases toward the ejection port 11a, the oxidizing gas supply pipe 220 is provided. The oxidizing gas supplied from the inside of the nozzle portion 11 and circulated inside the nozzle portion 11 is jetted at high speed. The fluid ejected from the nozzle portion 11 recirculates in the suction chamber 13 from the outside (outside the suction chamber 13 in the pressure vessel 205), entrains and mixes the oxidizing gas, and reduces the speed. Enter the diffuser section 12. The diffuser portion 12 has a slightly enlarged diameter in the vicinity of the opening 12a toward the upstream side so as to easily suck the fluid ejected from the ejection port 11a and the fluid in the suction chamber 13, but the downstream side from this portion is The cross-sectional area of the channel gradually increases toward the downstream. Therefore, the oxidizing gas is reduced in flow velocity in the diffuser portion 12, recovers pressure energy with almost no loss, and is discharged downstream from the diffuser portion 12. 2 and 4, a solid arrow indicates an oxidizing gas introduced from the outside of the pressure vessel 205, and a broken arrow indicates an oxidizing gas that is recirculated outside (inside the pressure vessel 205).

As a result, an increase in the flow rate of the recirculating oxidizing gas (exhaust oxidizing gas) mixed and mixed in the suction chamber 13 increases the flow rate from the oxidizing gas supply header 221 to the inside of the power generation unit 215 via the oxidizing gas supply gap 235a. The flow rate of the oxidizing gas introduced around each cell stack 101 increases. Since the temperature of the oxidizing gas supplied to the periphery of the cell stack 101 is lower than the temperature of the power generation section of the cell stack 101, the oxidizing gas supplied to the power generation section serves to cool the heat generated in the power generation reaction. Especially, in the region where the temperature is relatively high near the axially intermediate portion of the cell stack 101, the cooling effect becomes large because the temperature difference with the oxidizing gas is large. That is, it is effective to enhance the cooling effect of the cell stack 101 by increasing the flow rate of the oxidizing gas. Due to the increase in the flow rate of the oxidizing gas, the amount of cooling in the high temperature region in the central portion of the cell stack 101 in the axial direction is increased, and the equalization of the temperature distribution in the power generation unit is promoted.

Hereinafter, specific configuration examples of the oxidizing gas supply header 221 provided with the peripheral fluid suction tool 10 and the oxidizing gas discharge header 223 having the communication hole 220 will be described as a first embodiment and a second embodiment. In the first embodiment, the peripheral fluid suction tool 10 is externally attached to the oxidizing gas supply header 221, and in the second embodiment, the peripheral fluid suction tool 10 is built in the oxidizing gas supply header 221.

[3. First Embodiment]
(Constitution)
As shown in FIGS. 5 and 6, the oxidizing gas supply header 221 according to the first embodiment includes an oxidizing gas supply duct 50. The oxidizing gas supply duct 50 supplies the oxidizing gas to each of the oxidizing gas supply gaps 235a after the oxidizing gas is uniformly distributed in the circumferential direction of the SOFC cartridge 203, and blows the oxidizing gas to the power generation unit 215 substantially uniformly. This is for homogenizing the oxidizing gas used.

As shown in FIG. 6, the oxidizing gas supply duct 50 is arranged in the outer peripheral portion of the oxidizing gas supply header 221, and the long side portions 50L, 50L are arranged along the outer peripheral shape of the oxidizing gas supply header 221 in plan view. It is formed in a rectangular frame shape composed of 50L and short side portions 50S, 50S. Each of the short side portions 50S, 50S is provided with two opening joint portions 51 to which the connection pipes 14 connected to the peripheral fluid suction tool 10 are connected.

Except for the portion where the opening joint portion 51 is provided, the oxidizing gas supply duct 50 is formed in any transverse section perpendicular to the longitudinal direction as shown in FIG. 6(c). That is, there is a space 52 having a rectangular cross section inside the oxidizing gas supply duct 50, and the oxidizing gas flows and fills the space 52. The bottom wall 58 of the space 52 is provided with a blow hole 53 for blowing the oxidizing gas in the space 52 downward in the vertical direction.

As shown in FIG. 6A, a large number of the blowout holes 53 are formed side by side in a line in the bottom walls 58 of the long side portions 50L, 50L and the short side portions 50S, 50S. Here, the blowout holes 53 are dense near the ends of the long side portions 50L, 50L and the short side portions 50S, 50S, and are sparse toward the middle portions of the long side portions 50L, 50L and the short side portions 50S, 50S. It is arranged so that. With such arrangement of the blowout holes 53, the oxidizing gas is uniformly distributed in the circumferential direction of the SOFC cartridge 203, and then is supplied to the oxidizing gas supply gaps 235a so that the blowing amount to each cell stack 101 is increased. It can be uniformly optimized.

Further, as shown in FIG. 6C, in a space 55 below the oxidizing gas supply duct 50 in the vertical direction, through which the oxidizing gas is blown out from the blowout holes 53, a wall portion having an L-shaped cross section is formed. 54 is formed along the oxidizing gas supply duct 50. The inner surface 54a of the wall portion 54 serves as a guide surface for guiding the oxidizing gas blown out from the blowout hole 53 to the oxidizing gas supply space 56 which is the internal space of the oxidizing gas supply header 221. The oxidizing gas supply space 56 communicates with the power generation unit 215 via the oxidizing gas supply gap 235a as shown in FIG.

Further, in FIG. 6(c), members located in the periphery when the oxidizing gas supply duct 50 is installed as the oxidizing gas supply header 221 are shown by a chain double-dashed line, and the oxidizing gas supply duct 50 is It is installed along the side wall of the lower casing 229b between the lower heat insulator 227b and the lower tube sheet 225b. An oxidizing gas supply gap 235a is formed between the lower heat insulator 227b and the outer surface (lead portion 115) of the inserted cell stack 101 (see FIG. 2).

In the present embodiment, the peripheral fluid suction device 10 includes the oxidizing gas supply branch pipe 220a of the oxidizing gas supply pipe 220 connected to the SOFC cartridge 203 in each of the short sides 50S and 50S of the oxidizing gas supply duct 50. , Is provided between the oxidizing gas supply duct 50 and the opening joint portion 51. Two opening joint parts 51 are provided on each of the short side parts 50S, 50S, but the peripheral fluid suction tool 10 is connected to each opening joint part 51 via the connecting pipe 14 whose downstream side is bifurcated. Therefore, only one peripheral fluid suction tool 10 is installed on each short side portion 50S, 50S. The number of the opening joint portions 51 is not limited to two, and may be one or three or more. The connection pipes 14 are prepared and connected so that the number of branches matches the number of the opening joint portions 51.

As described above, the peripheral fluid suction device 10 includes the nozzle portion 11, the diffuser portion 12, and the suction chamber 13, and the upstream end of the nozzle portion 11 is connected to the downstream end of the oxidizing gas supply branch pipe 220a. The downstream end (opening end on the outlet side) of the diffuser portion 12 is communicatively connected to the upstream end of the connecting pipe 14. Each of the two downstream ends of the connecting pipe 14 is connected to the corresponding opening joint portion 51. In FIG. 5, the display of the suction chamber 13 is omitted.

The nozzle portion 11 is formed in a tapered shape in which the flow passage cross-sectional area gradually decreases toward the ejection port 11a. The diffuser part 12 has a slightly enlarged diameter in the vicinity of the opening 12a toward the upstream side, and it is easy to suck the fluid injected from the injection port 11a and the fluid (oxidizing gas) in the suction chamber 13 from this part. On the downstream side, the cross-sectional area of the flow passage gradually increases toward the downstream side. Further, the suction chamber 13 is provided with an inlet port 13 a for introducing an external fluid (oxidizing gas) into the suction chamber 13.

Further, the oxidizing gas discharge header 223 according to the first embodiment is provided with an exhaust oxidizing gas discharge duct 60 as shown in FIG. 7. The exhaust oxidizing gas exhaust duct 60 uniformizes and exhausts the exhaust oxidizing gas in the circumferential direction from the oxidizing gas exhaust gaps 235b, thereby rectifying the flow of the oxidizing gas to the cell stacks 101. This is for making the flow rate of the oxidizing gas supplied uniform.

The exhausted oxidizing gas exhaust duct 60 is disposed on the outer peripheral portion of the oxidizing gas exhaust header 223, and the long side portions 60L and 60L and the short side portion 60S are arranged along the outer peripheral shape of the oxidizing gas exhaust header 223 in plan view. , 60S in a rectangular frame shape. Each of the short sides 60S, 60S is provided with an opening joint portion 61 connected to the oxidizing gas discharge branch pipe 222a of the oxidizing gas discharge pipe 222.

Exhaust oxidizing gas exhaust duct 60 is formed as shown in FIG. 7(b) in any cross section except for the portion where this opening joint portion 61 is provided. That is, a space 62 having a rectangular cross section is provided inside the exhaust oxidizing gas exhaust duct 60, and an inner wall 67 of the exhaust oxidizing gas exhaust duct 60 communicates with the internal space 65 of the oxidizing gas exhaust header 223. A discharge hole 63 is provided. The internal space 65 communicates with the power generation unit 215 via the oxidizing gas discharge gap 235b.

As shown in FIG. 7A, a large number of the discharge holes 63 are formed on the inner side walls 67 of the long side portions 60L, 60L and the short side portions 60S, 60S side by side in a row. Here, the discharge holes 63 are arranged at the long side portions 60L, 60L and the short side portions 60S, 60S at substantially equal intervals, but it is more preferable in order to further optimize the uniformity of the oxidizing gas in the circumferential direction. If there is an arrangement interval, the discharge holes 63 may be arranged accordingly.

For example, like the blow-out hole 53 in the oxidizing gas supply duct 50 described with reference to FIG. 6A, the exhaust hole 63 in the exhaust oxidizing gas exhaust duct 60 has the long side portions 60L, 60L and the short side portions 60S, By arranging so as to become dense near each end portion of 60S and become sparse toward the middle portion of the long side portions 60L, 60L and the short side portions 60S, 60S, the discharge amount of the exhaust oxidizing gas in the circumferential direction. The homogenization may be optimized.

Note that, in FIG. 7B, the members located in the periphery when the exhaust oxidizing gas exhaust duct 60 is installed as the exhaust oxidizing gas exhaust header 223 are indicated by a chain double-dashed line. 60 is installed along the side wall of the upper casing 229a between the upper heat insulator 227a and the upper tube sheet 225a. An oxidizing gas discharge gap 235b is formed between the upper heat insulator 227a and the outer surface of the inserted cell stack 101 (see FIG. 2).

As a result, the oxidizing gas that has been used for power generation in the power generation unit 215 is introduced into the internal space 65 through the oxidizing gas discharge gap 235b, and is further introduced into the space 62 through the discharge hole 63. The gas is discharged from the opening joint portion 61 to the outside of the pressure vessel 205 through the oxidizing gas discharge pipe 222. Since the opening joint portion 61 does not directly open to the internal space 65, and the internal space 65 communicates with the opening joint portion 61 via the exhaust hole 63 and the exhausted oxidizing gas exhaust duct 60, each oxidizing The oxidizing gas is uniformly discharged in the circumferential direction from the gas discharge gap 235b.

Then, as shown in FIG. 7A, the outer wall 67 of the exhaust oxidizing gas exhaust duct 60 has a space 62 inside the exhaust oxidizing gas exhaust duct 60 and the outside (SOFC cartridge inside the pressure vessel 205 inside). A communication hole 20 that communicates with a space (outside of 203) is formed. Here, the communication hole 20 is formed at one position on each of the outer side walls 67 of the short side portions 60S, 60S, and is equal to or slightly larger than the total exhaust area of the multiple discharge holes 63. The diametrical size is formed so as to ensure uniform exhaust from the internal space 65 of the oxidizing gas exhaust header 223.

That is, in the space 62 of the exhaust oxidizing gas exhaust duct 60, the oxidizing gas introduced from the exhaust hole 63 is exhausted to the outside of the pressure vessel 205 mainly from the opening joint portion 61 through the oxidizing gas exhaust pipe 222. However, a part thereof is led out to the outside of the oxidizing gas discharge header 223 through the communication hole 20. A part of the oxidizing gas (exhaust oxidizing gas) led out from the communication hole 20 flows into the suction chamber 13 of the peripheral fluid suction tool 10 in the pressure container 205, and then flows from the outside of the SOFC cartridge 203 to the inside again. In order to smoothly perform this recirculation, the communication hole 20 is provided so as to limit the discharge place only to the short side portions 60S, 60S above the peripheral fluid suction device 10. ..

(Action and effect)
Since the SOFC cartridge 203 according to the first embodiment is equipped with the peripheral fluid suction tool 10 at the inlet portion of the oxidizing gas supply header 221, the peripheral fluid suction tool 10 allows the oxidizing gas supply header 10 to operate. The flow rate of the oxidizing gas introduced into 221 increases, and the flow rate of the oxidizing gas introduced around each cell stack 101 in the power generation unit 215 increases. Since the temperature of the oxidizing gas supplied to the periphery of the cell stack 101 is lower than the temperature of the power generation section of the cell stack 101, the oxidizing gas supplied to the power generation section serves to cool the heat generated in the power generation reaction. The cooling effect of the power generation part of the cell stack 101 is enhanced by the increased flow rate of the oxidizing gas. Further, the increase in the flow rate increases the cooling amount in the high temperature region of the central portion of the cell stack 101 in the axial direction, and promotes the equalization of the temperature distribution in the power generation unit.

In the SOFC cartridge 203, since the internal resistance becomes small in the high temperature region, the electrochemical reaction easily proceeds, but conversely, the electric resistance becomes large in the low temperature region, the electrochemical reaction decreases, and the power generation amount decreases. Therefore, by making the temperature distribution of the power generation section of each SOFC stack 101 of the SOFC cartridge 203 more uniform, it is possible to further increase the power generation output.

The peripheral fluid suction tool 10 uses the pressure energy possessed by the oxidizing gas to be supplied, does not need to be powered, such as a pump, and does not require auxiliary equipment such as a blower for recirculation. The structure is simple and can be installed in a small space. Therefore, the cooling effect of the power generation section of the cell stack 101 can be enhanced without introducing new problems such as increased cost, increased space, and complicated operation/control.
That is, since the exhausted oxidizing gas in the pressure vessel 205 is drawn in by utilizing the flow of the pressure energy of the oxidizing gas supplied from outside the SOFC module 201, there is a temperature difference between the power generation unit and the inside of the pressure vessel 205. Even when the convection is small and the stack effect from the lower part to the upper part of the SOFC cartridge 203 in the vertical direction is small, the backflow of the oxidizing gas can be reliably prevented, so that the cooling effect of the power generation part is promoted.

Further, the oxidizing gas supply header 221 uniformly supplies the oxidizing gas from the lower portion of the SOFC cartridge 203 to the cell stack 101, and the oxidizing gas discharge header 223 uniformly discharges the oxidizing gas from the power generation unit 215. In addition to this, by discharging the oxidizing gas into the pressure vessel 205 as the discharged acidified gas from the communication hole 20 of the oxidizing gas discharge header 223, Since it is recirculated so as to flow from the outside to the inside of the SOFC cartridge 203 again, there is an effect that the flow of the acidified gas in the power generation unit is made uniform and the temperature distribution in the power generation unit can be made uniform.

In addition, the peripheral fluid suction tool 10 of the present embodiment is provided between the oxidizing gas supply branch pipe 220a of the oxidizing gas supply pipe 220 and the opening joint portion 51 of the oxidizing gas supply duct 50, that is, the oxidizing gas supply. Since it is externally mounted on the outside of the header 221, the existing SOFC cartridge 203 can be implemented with only a slight change, and the cost increase can be suppressed.

[4. Second Embodiment]
(Constitution)
As shown in FIGS. 8 to 10, the oxidizing gas supply header 221 according to the second embodiment also includes an oxidizing gas supply duct 50A similar to the oxidizing gas supply duct 50 of the first embodiment. 8 to 10, the same reference numerals as those in FIGS. 5 and 6 indicate the same members, and therefore the description thereof will be simplified and the configuration unique to the oxidizing gas supply duct 50A of the present embodiment will be mainly described. Explained.

As shown in FIGS. 8 and 9, the oxidizing gas supply duct 50A is arranged on the outer peripheral portion of the oxidizing gas supply header 221, and has long sides along the outer peripheral shape of the oxidizing gas supply header 221 in plan view. The parts 50L and 50L and the short side parts 50S and 50S are formed in a rectangular frame shape.

Each of the short sides 50S, 50S is provided with two opening joint parts 51 to which the oxidizing gas supply branch pipes 220a of the oxidizing gas supply pipe 220 are connected in communication. When only one oxidizing gas supply branch pipe 220a is provided for each short side portion 50S, 50S, as in the first embodiment, the oxidizing gas supply branch pipe 220a is connected via the connecting pipe 14 whose downstream is branched. The supply branch pipe 220a and the opening joint 51 are connected.

As shown in FIGS. 10A and 10B, the oxidizing gas supply duct 50A also has a space 52 having a rectangular cross section inside, and the oxidizing gas flows through the space 52. Further, the bottom wall 58 of the space 52 is provided with a blowout hole 53 for blowing out the oxidizing gas in the space 52 downward.

As shown in FIGS. 9A, 10A, and 10B, the blowout holes 53 are installed in series on the bottom walls 58 of the long side portions 50L and 50L and the short side portions 50S and 50S. And are formed side by side. Here, the blowout holes 53 are dense near the ends of the long side portions 50L, 50L and the short side portions 50S, 50S, and are sparse toward the middle portions of the long side portions 50L, 50L and the short side portions 50S, 50S. It is arranged so that. With such arrangement of the blowout holes 53, the oxidizing gas is evenly distributed in the circumferential direction of the SOFC cartridge 203, and then is supplied to the oxidizing gas supply gaps 235a to control the blowing amount of each of the cell stacks 101. The uniformity can be optimized.

As shown in FIG. 10, a wall portion 54 having an L-shaped cross section is provided in the oxidizing gas supply duct 50 in a space 55 below the oxidizing gas supply duct 50A where the oxidizing gas is blown from the blowout holes 53. It is formed along. The inner surface 54a of the wall portion 54 serves as a guide surface for guiding the oxidizing gas blown out from the blowout hole 53 to the oxidizing gas supply space 56 which is the internal space of the oxidizing gas supply header 221. The oxidizing gas supply space 56 communicates with the power generation unit 215 via the oxidizing gas supply gap 235a.

In the present embodiment, as shown in FIGS. 8 to 10, the peripheral fluid suction device 10A is provided in a position corresponding to a part of the blowout holes 53 in the space 55, and is oxidized to the opening 12b on the outlet side. The gas stream is designed to flow.
As described above, the peripheral fluid suction device 10A includes the nozzle portion 11A, the diffuser portion 12A, and the suction chamber 13A.

As shown in FIGS. 10A and 10B, the nozzle portion 11A is connected so that its upstream end communicates with the blowout hole 53, and the middle portion is bent so that the injection port 11a has an oxidizing gas supply header 221. Of the oxidizing gas supply space 56. The diffuser portion 12 has an opening 12a on the inlet side arranged at a position where the injected oxidizing gas is introduced, a downstream side of which the diameter is increased is directed to the oxidizing gas supply space 56, and an opening 12b on the outlet side is formed by the oxidizing gas. It opens to the supply space 56. Further, a wall portion 59 is provided between the space 55 and the oxidizing gas supply space 56 to partition a portion of the diffuser portion 12 other than the downstream side opening. The suction chamber 13A is formed by being partitioned by the wall portion 59 and also by partitioning the interior of the space 55 in the longitudinal direction (direction orthogonal to the paper surface of FIG. 10) by a wall portion (not shown).

The outlet holes 53 and the outlet-side openings 12b are formed in a long and narrow slit shape so that the oxidizing gas flowing from the outlet holes 53 to the outlet-side openings 12b is uniformly ejected and flows in the oxidizing gas supply duct 50A. It may have been done. Further, the blowout holes 53 and the openings 12b on the outlet side do not necessarily have to be arranged at equal intervals, and the sparse portion and the dense portion may be arranged to improve the uniformity.

Further, an inlet port 15 for introducing an external oxidizing gas (external to the SOFC cartridge 203 in the pressure container 205) into the suction chamber 13A is provided in a part of the side wall of the wall 54 that defines the space 55. ing. Here, as shown in FIG. 10A, the inlet port 15 is provided on the axis of the diffuser portion 12A of the peripheral fluid suction tool 10A provided corresponding to the lower portion of the paper of the opening joint portion 51. Therefore, two introduction ports 15 are provided for each short side portion 50S, 50S.

On the other hand, in the peripheral fluid suction tool 10A provided on each of the long side portions 50L and 50L, as shown in FIG. 10B, the introduction port 15 is not directly provided in the vicinity thereof, but the oxidizing gas supply duct 50A is provided. An inner space 55 extends in the longitudinal direction and communicates with each other, and the exhausted oxidizing gas introduced from the introduction port 15 can be introduced over the entire circumference of the peripheral fluid suction device 10A.

Further, the oxidizing gas discharge header 223 according to the second embodiment is provided with the discharged oxidizing gas discharge duct 60 similarly to the oxidizing gas discharge header 223 according to the first embodiment shown in FIG. 7, and here, To simplify the description, the internal space of the oxidizing gas exhaust header 223 (the space 62 of the exhaust oxidizing gas exhaust duct 60) and the external space (inside the pressure vessel 205 and outside the SOFC cartridge 203) communicate with each other. A communication hole 20 is formed.

(Action and effect)
Since the SOFC cartridge 203 according to the present embodiment is equipped with the peripheral fluid suction tool 10A inside the acid-oxidizing gas supply header 221, as described above, a part of the oxidizing gas exhausted by the peripheral fluid suction tool 10 is used. Is taken in as a recirculation, the flow rate of the oxidizing gas introduced around each cell stack 101 in the power generation unit 215 increases. Since the temperature of the oxidizing gas supplied around the cell stack 101 is lower than the temperature of the power generation unit of the cell stack 101, the oxidizing gas supplied to the power generation unit 215 plays a role of cooling the heat generated in the power generation reaction. As a result, the cooling effect of the power generation part of the cell stack 101 can be enhanced by the increased flow rate of the oxidizing gas. Further, the increase in the flow rate increases the cooling amount in the high temperature region of the central portion of the cell stack 101 in the axial direction, and promotes the equalization of the temperature distribution in the power generation unit. The SOFC cartridge 203 can further increase the power generation output by making the temperature distribution of the power generation unit of each SOFC stack 101 more uniform.

Similar to the first embodiment, the peripheral fluid suction tool 10 uses the pressure energy possessed by itself, does not require the application of power such as a pump, and does not require auxiliary equipment such as a blower for recirculation. Besides, the structure is simple and it can be installed in a small space. Therefore, the cooling effect of the power generation unit of the cell stack 101 can be enhanced without introducing new problems such as increased cost, increased space, and complicated operation/control.

Further, since the peripheral fluid suction tool 10 of the present embodiment can be installed inside the oxidizing gas supply header 221, the power generation unit of the cell stack 101 can be installed without increasing the outer shape of the cell stack 101. It is possible to enhance the cooling effect, improve the temperature distribution of the plurality of cell stacks 101, and increase the power generation output.

[5. Other]
Although the embodiments of the present invention have been described above, the present invention can be implemented by appropriately modifying each embodiment without departing from the spirit of the present invention.
For example, it is effective to combine the first embodiment and the second embodiment.

In addition, the peripheral fluid suction tool sucks the exhausted oxidizing gas as the peripheral fluid by the ejector action using the flow of the oxidizing gas supplied from the oxidizing gas supply pipe to the oxidizing gas supply header to supply the oxidizing gas. Anything can be introduced as long as it can be introduced into the header, and the present invention is not limited to the above embodiment.
Further, the location of the peripheral fluid suction tool is not limited to that in the above embodiment.

In addition, for example, in the case where the oxidizing gas supply duct is used to install the peripheral fluid suction tool as in the second embodiment, the oxidizing gas supply duct in the oxidizing gas supply header and the oxidizing gas discharge header in the oxidizing gas supply header are excluded. The exhaust oxidizing gas exhaust duct is not essential and can be omitted.

10 Peripheral fluid suction tool 11 Nozzle part 11a Nozzle part 11
12 Diffuser part 12a Entrance side opening of the diffuser part 12b 12b Exit side opening 13 Suction chamber 13a Inlet port 14 Connection pipe 15 Inlet port 20 Communication hole 50, 50A Oxidizing gas supply duct 53 Outlet hole 54 Wall having guide surface 54a Part 54a Guide surface 56 Oxidizing gas supply space 60 Exhaust oxidizing gas exhaust duct 101 Fuel cell stack (cell stack)
201 Fuel cell module (SOFC module)
203 Fuel cell cartridge (SOFC cartridge)
205 Pressure vessel (module vessel)
215 Power generation unit 220 Oxidizing gas supply pipe 220a Oxidizing gas supply branch pipe 221 Oxidizing gas supply header (oxidizing gas supply chamber)
222 Oxidizing gas exhaust pipe 222a Oxidizing gas exhaust branch pipe 223 Oxidizing gas exhaust header (oxidizing gas exhaust chamber)
235a Oxidizing gas supply gap 235b Oxidizing gas discharge gap

Claims (8)

A fuel cell stack,
An oxidizing gas supply header that is arranged on one end side of the plurality of fuel cell stacks and supplies the oxidizing gas supplied from an oxidizing gas supply pipe to the periphery of the fuel cell stacks,
An oxidizing gas discharge header that is disposed on the other end side of the fuel cell stack and discharges the oxidizing gas that has passed around the fuel cell stack,
And a fuel cell cartridge equipped in a module container,
A communication hole that communicates the internal space of the oxidizing gas discharge header with the space inside the module container and outside the fuel cell cartridge;
At least a part of the oxidizing gas in the module container is introduced into the oxidizing gas supply header by an ejector action utilizing the flow of the oxidizing gas supplied from the oxidizing gas supply pipe to the oxidizing gas supply header. A fuel cell cartridge, which is equipped with a peripheral fluid suction tool to be introduced. 2. The fuel cell cartridge according to claim 1, wherein the peripheral fluid suction tool is provided between the oxidizing gas supply pipe and the oxidizing gas supply header. The oxidizing gas supply header is
An oxidizing gas supply duct to which the oxidizing gas supply pipe is connected,
A plurality of blow-out holes formed in the oxidizing gas supply duct, for blowing out the oxidizing gas supplied in the oxidizing gas supply duct;
And a wall portion having a guide surface which the oxidation gas discharged from the outlet hole for guiding the oxidizing gas supply space leading to oxidation gas supply gap,
3. The fuel cell cartridge according to claim 2, wherein the peripheral fluid suction tool is provided between the oxidizing gas supply pipe and the oxidizing gas supply duct. The oxidizing gas supply header is
An oxidizing gas supply duct to which the oxidizing gas supply pipe is connected,
A plurality of blow-out holes formed in the oxidizing gas supply duct, for blowing out the oxidizing gas supplied in the oxidizing gas supply duct;
And a wall portion having a guide surface the oxidizing gases blown out of the outlet hole, to guide the oxidizing gas supply space leading to oxidation gas supply gap,
The fuel cell cartridge according to claim 1, wherein the peripheral fluid suction tool is provided between at least a part of the plurality of outlets and the oxidizing gas supply space. The wall portion having the guide surface is provided with an inlet for introducing at least a part of the oxidizing gas in the module container into the oxidizing gas supply header. The fuel cell cartridge according to claim 4. The peripheral fluid suction device is
A nozzle portion for injecting the oxidizing gas supplied from the oxidizing gas supply pipe,
A diffuser portion provided on the downstream side of the nozzle portion and having an opening into which the injected oxidizing gas is introduced;
A suction chamber for sucking at least a part of the oxidizing gas in the module container into the opening of the diffuser portion;
The fuel cell cartridge according to any one of claims 1 to 5, further comprising: A fuel cell module comprising a plurality of fuel cell cartridges according to any one of claims 1 to 6 in a module container. A fuel cell stack,
An oxidizing gas supply header that is arranged on one end side of the plurality of fuel cell stacks and supplies the oxidizing gas supplied from an oxidizing gas supply pipe to the periphery of the fuel cell stacks,
An oxidizing gas discharge header that is disposed on the other end side of the fuel cell stack and discharges the oxidizing gas that has passed around the fuel cell stack,
In a fuel cell cartridge provided in a module container, a method for cooling the fuel cell stack, comprising:
Part of the oxidizing gas inside the oxidizing gas discharge header is discharged into the space inside the module container and outside the fuel cell cartridge,
At least a part of the oxidizing gas discharged into the module container is supplied to the oxidizing gas by an ejector action utilizing the flow of the oxidizing gas supplied from the oxidizing gas supply pipe to the oxidizing gas supply header. A method for cooling a fuel cell stack, comprising: introducing into a header to increase a flow rate of the oxidizing gas supplied to the fuel cell stack.

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