JP2021118067A - Fuel cell cartridge and fuel cell module - Google Patents

Abstract

To provide a fuel cell cartridge and a fuel cell module, which achieve a high output by suppressing the generation of ground fault current in a high temperature range.SOLUTION: A fuel cell cartridge includes: a thermal insulation member that at least partially demarcates a power generation chamber that contains fuel cells; a conductive member that is provided to an outer side; and an insulation member that has higher insulating properties than the thermal insulation member in temperature ranges higher than an ordinary temperature. The insulation member is configured such that, when a lead portion of a cell stack is in contact with the thermal insulation member, a conductive channel formed between the lead portion and the conductive member is at least partially blocked.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to a fuel cell cartridge and a fuel cell module.

A fuel cell that generates electricity by chemically reacting a fuel gas and an oxidizing gas has characteristics such as excellent power generation efficiency and environmental friendliness. Of these, solid oxide fuel cells (SOFCs) use ceramics such as zirconia ceramics as the electrolyte, and gasify hydrogen, city gas, natural gas, petroleum, methanol, and carbon-containing raw materials. Gas such as gasification gas produced in the above is supplied as fuel gas and reacted in a high temperature atmosphere of about 700 ° C. to 1000 ° C. to generate power.

For example, Patent Document 1 discloses an example of a solid oxide fuel cell. In this document, a power generation chamber having a high temperature atmosphere inside is defined so as to be surrounded by a heat insulating member, and the outside thereof is surrounded by a casing made of a conductive material such as metal.

Japanese Unexamined Patent Publication No. 2018-139193

In Patent Document 1, a casing containing a conductive material is arranged outside the heat insulating member that defines the power generation chamber, and the heat insulating member and the casing are in contact with each other. The heat insulating member is _{composed of an insulating material such as silica (SiO 2} ) or alumina (Al ₂ O ₃ ), and such a heat insulating member is good at room temperature (for example, in a temperature range of about 0 ° C. to 40 ° C.). Although it exhibits insulating properties, the insulating properties may decrease as the temperature rises.

Here, in Patent Document 1, in order to take out the electric power generated in the power generation chamber to the outside, the lead portion of the cell stack including the fuel cell extends from the power generation chamber to the outside of the heat insulating member. The lead part is designed so that the lead part does not come into contact with the heat insulating member in the normal temperature range by inserting the lead part into a hole provided in the heat insulating member with a diameter larger than that of the lead part. When it reaches, the lead portion may come into contact with the heat insulating member due to the influence of thermal deformation or the like. At this time, if the insulating property of the heat insulating member is deteriorated, a ground fault current may be generated between the lead portion and the casing due to the potential difference between the two. In order to prevent the occurrence of such a ground fault current, it is necessary to suppress the output voltage from the cell stack, and it has been difficult to realize a high output fuel cell cartridge.

At least one embodiment of the present disclosure has been made in view of the above circumstances, and provides a high-output fuel cell cartridge and a fuel cell module by suppressing the generation of a ground fault current in a high temperature region. The purpose.

The fuel cell cartridge according to at least one embodiment of the present disclosure is used to solve the above problems.
A power generation room containing fuel cell cells that make up the cell stack,
With a heat insulating member that at least partially defines the power generation chamber,
A conductive member provided outside the heat insulating member when viewed from the power generation chamber, and
It has a higher insulating property than the heat insulating member in a temperature range higher than normal temperature, and at least a conductive path formed between the lead portion and the conductive member when the lead portion of the cell stack comes into contact with the heat insulating member. Insulation members configured to partially block,
To be equipped.

According to at least one embodiment of the present disclosure, a high output fuel cell cartridge and a fuel cell module can be provided by suppressing the generation of a ground fault current in a high temperature region.

It shows one aspect of the cell stack which concerns on embodiment. It shows one aspect of the fuel cell module which concerns on this embodiment. It shows the cross-sectional view of one aspect of the fuel cell cartridge which concerns on this embodiment. This is a first modification of FIG. This is a second modification of FIG. This is a third modification of FIG. This is a fourth modification of FIG.

Hereinafter, an embodiment of the fuel cell cartridge and the fuel cell module according to the present disclosure will be described with reference to the drawings.

In the following, for convenience of explanation, the positional relationships of the respective components described using the expressions “upper” and “lower” with respect to the paper surface indicate the vertically upper side and the vertically lower side, respectively. Further, in the present embodiment, the one that can obtain the same effect in the vertical direction and the horizontal direction is not necessarily limited to the vertical vertical direction on the paper surface, but may correspond to the horizontal direction orthogonal to the vertical direction, for example. good.

Further, in the following, a cylindrical (cylindrical) cell stack will be described as an example of the solid oxide fuel cell (SOFC) cell stack, but this is not necessarily the case, and for example, a flat cell stack. May be good. The fuel cell is formed on the substrate, but the electrode (fuel electrode or air electrode) is formed thicker instead of the substrate, and the substrate may also be used.

First, as an example of the present embodiment with reference to FIG. 1, a cylindrical cell stack using a substrate tube will be described. When the base tube is not used, for example, the fuel electrode may be formed thick and the base tube may also be used, and the use of the base tube is not limited. Further, although the substrate tube in the present embodiment will be described using a cylindrical shape, the substrate tube may be tubular, and the cross section is not necessarily limited to a circular shape, and may be, for example, an elliptical shape. A cell stack such as a flat cylinder in which the peripheral side surface of the cylinder is vertically crushed may be used. Here, FIG. 1 shows one aspect of the cell stack according to the embodiment. As an example, the cell stack 101 includes a cylindrical base tube 103, a plurality of fuel cell 105 formed on the outer peripheral surface of the base tube 103, and an interconnector 107 formed between adjacent fuel cell 105. .. The fuel cell 105 is formed by laminating a fuel electrode 109, a solid electrolyte membrane 111, and an air electrode 113. Further, the cell stack 101 is attached to the air electrode 113 of the fuel cell 105 formed at one end of the plurality of fuel cell 105 formed on the outer peripheral surface of the base tube 103 in the axial direction of the base tube 103. , A lead film 115 electrically connected via an interconnector 107, and a lead film 115 electrically connected to a fuel electrode 109 of a fuel cell 105 formed at the other end of the end (cell). The lead portion 252 of the stack 101 (see FIG. 3 and the like) includes the lead film 115).

Substrate tube 103 is made of a porous material, for example, CaO-stabilized _ZrO 2 (CSZ), a mixture of CSZ and nickel oxide (NiO) (CSZ + NiO) , or _Y 2 _{O 3} stabilized _ZrO 2 (YSZ), or The main component is _{MgAl 2} O _{4 and the like.} The base tube 103 supports the fuel cell 105, the interconnector 107, and the lead film 115, and the fuel gas supplied to the inner peripheral surface of the base tube 103 is supplied to the inner peripheral surface of the base tube 103 through the pores of the base tube 103. It is diffused in the fuel electrode 109 formed on the outer peripheral surface of the above.

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. The thickness of the fuel pole 109 is 50 μm to 250 μm, and the fuel pole 109 may be formed by screen printing the slurry. 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 reacts a fuel gas supplied via the substrate tube 103, for example, _{a mixed gas of methane (CH 4} ) and water vapor, and _{reforms it into hydrogen (H 2} ) and carbon monoxide (CO). It is a thing. Further, in the fuel electrode 109, hydrogen (H ₂ ^{) and carbon monoxide (CO) obtained by reforming and oxygen ions (O 2-} ) supplied via the solid electrolyte film 111 are combined with the solid electrolyte film 111. Water (H2O) and carbon dioxide (CO2) are produced by electrochemically reacting in the vicinity of the interface between the two. At this time, the fuel cell 105 generates electricity by the electrons emitted from the oxygen ions.
The fuel gases that can be supplied and used for the fuel electrode 109 of the solid oxide fuel cell include _{hydrocarbon gases such as hydrogen (H 2} ), carbon monoxide (CO), and methane (CH ₄ ), city gas, and natural gas. In addition, gasification gas produced by gasifying equipment for carbon-containing raw materials such as petroleum, methanol, and coal can be mentioned.

As the solid electrolyte membrane 111, YSZ having airtightness that makes it difficult for gas to pass through and high oxygen ion conductivity at high temperature is mainly used. The solid electrolyte membrane 111 ^{moves oxygen ions (O2-} ) generated at the air electrode to the fuel electrode. The film thickness of the solid electrolyte film 111 located on the surface of the fuel electrode 109 is 10 μm to 100 μm, and the solid electrolyte film 111 may be formed by screen printing the slurry.

The air electrode 113 is composed of, for example, a LaSrMnO _3- based oxide or a LaCoO _3- based oxide, and the air electrode 113 is coated with a slurry by screen printing or using a dispenser. The air electrode 113 dissociates oxygen in an oxidizing gas such as air to be supplied in the vicinity of the interface with the solid electrolyte membrane 111 to generate ^{oxygen ions (O 2-).}
The air electrode 113 may have a two-layer structure. In this case, the air electrode layer (air electrode intermediate layer) on the solid electrolyte membrane 111 side is made of a material showing high ionic conductivity and excellent catalytic activity. The air electrode layer (air electrode conductive layer) on the air electrode intermediate layer may be composed of a perovskite-type oxide represented by _{Sr and Ca-doped LaMnO 3.} By doing so, the power generation performance can be further improved.
The oxidizing gas is a gas containing approximately 15% to 30% of oxygen, and air is typically preferable. However, in addition to air, a mixed gas of combustion exhaust gas and air, a mixed gas of oxygen and air, etc. Can be used.

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 and L is a lanthanoid element) such as _{SrTiO 3 system, and screen prints a slurry.} do. The interconnector 107 has a dense film so that the fuel gas and the oxidizing gas do not mix with each other. Further, the interconnector 107 has stable durability and electrical conductivity in both an oxidizing atmosphere and a reducing atmosphere. In the adjacent fuel cell 105, the interconnector 107 electrically connects the air electrode 113 of one fuel cell 105 and the fuel electrode 109 of the other fuel cell 105, and the adjacent fuel cell 105 are connected to each other. Are connected in series.

Since the lead film 115 needs to have electron conductivity and a coefficient of thermal expansion close to that of other materials constituting the cell stack 101, Ni such as Ni / YSZ and a zirconia-based electrolyte material are used. It is composed of M1-xLxTiO ₃ (M is an alkaline earth metal element and L is a lanthanoid element) such as a composite material and SrTiO _{3 system.} The lead film 115 derives the DC power generated by the plurality of fuel cell 105s connected in series by the interconnector 107 to the lead portion 252 (see FIG. 3 and the like) near the end of the cell stack 101. It is a thing.

Next, the fuel cell module and the fuel cell cartridge according to the present embodiment will be described with reference to FIGS. 2 and 3. Here, FIG. 2 shows one aspect of the fuel cell module according to the present embodiment. Further, FIG. 3 shows a cross-sectional view of one aspect of the fuel cell cartridge according to the present embodiment.
In FIG. 2, in order to show the internal configuration of the fuel cell module in an easy-to-understand manner, a part of the heat insulating member shown in FIG. 3 is partially omitted.

As shown in FIG. 2, the fuel cell module 201 includes, for example, a plurality of fuel cell cartridges 203 and a pressure vessel 205 for accommodating the plurality of fuel cell cartridges 203. Although the cell stack 101 of the cylindrical fuel cell is illustrated in FIG. 2, this is not necessarily the case, and for example, a flat cell stack may be used. Further, the fuel cell module 201 includes a fuel gas supply pipe 207, a plurality of fuel gas supply branch pipes 207a, a fuel gas discharge pipe 209, and a plurality of fuel gas discharge branch pipes 209a. Further, the fuel cell module 201 includes an oxidizing gas supply pipe (not shown), an oxidizing gas supply branch pipe 211a (see FIG. 3), an oxidizing gas discharge pipe (not shown), and a plurality of oxidizing gas discharge branches. It includes 211b (see FIG. 3).

A plurality of fuel gas supply pipes 207 are provided outside the pressure vessel 205 and are connected to a fuel gas supply unit that supplies fuel gas having a predetermined gas composition and a predetermined flow rate according to the amount of power generated by the fuel cell module 201. It is connected to the fuel gas supply branch pipe 207a of. The fuel gas supply pipe 207 branches and guides a predetermined flow rate of fuel gas supplied from the above-mentioned fuel gas supply unit to a plurality of fuel gas supply branch pipes 207a. Further, the fuel gas supply branch pipe 207a is connected to the fuel gas supply pipe 207 and is also connected to a plurality of SOFC fuel cell cartridges 203. The fuel gas supply branch pipe 207a guides the fuel gas supplied from the fuel gas supply pipe 207 to the plurality of fuel cell cartridges 203 at a substantially equal flow rate, and substantially equalizes the power generation performance of the plurality of fuel cell cartridges 203. Is.

The fuel gas discharge branch pipe 209a is connected to a plurality of fuel cell cartridges 203 and is also connected to the fuel gas discharge pipe 209. The fuel gas discharge branch pipe 209a guides the exhaust fuel gas discharged from the fuel cell cartridge 203 to the fuel gas discharge pipe 209. Further, the fuel gas discharge pipe 209 is connected to a plurality of fuel gas discharge branch pipes 209a, and a part of the fuel gas discharge pipe 209 is arranged outside the pressure vessel 205. The fuel gas discharge pipe 209 guides the exhaust fuel gas led out from the fuel gas discharge branch pipe 209a at a substantially equal 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 3 MPa and an internal temperature of atmospheric temperature to about 550 ° C., it has a proof stress and corrosion resistance against an oxidizing agent such as oxygen contained in the oxidizing gas. The material you have is used. For example, a stainless steel material such as SUS304 is suitable.

Here, in the present embodiment, a mode in which a plurality of fuel cell cartridges 203 are assembled and stored in the pressure vessel 205 will be described, but the present invention is not limited to this, and for example, the fuel cell cartridge 203 is not assembled. It can also be stored in the pressure vessel 205.

As shown in FIG. 3, the fuel cell cartridge 203 includes a plurality of cell stacks 101, a power generation chamber 215, a fuel gas supply header 217, a fuel gas discharge header 219, an oxidizing gas (air) supply header 221 and oxidation. It is provided with a sex gas discharge header 223.

In the present embodiment, in the fuel cell cartridge 203, the fuel gas supply header 217, the fuel gas discharge header 219, the oxidizing gas supply header 221 and the oxidizing gas discharge header 223 are arranged as shown in FIG. The structure is such that the fuel gas and the oxidizing gas flow toward the inside and the outside of the cell stack 101, but this is not always necessary. For example, the inside and the outside of the cell stack 101 are parallel to each other. The flowing or oxidizing gas may be allowed to flow in a direction orthogonal to the longitudinal direction of the cell stack 101.

The power generation chamber 215 is a region in which the fuel cell 105 of the cell stack 101 is arranged, and is a region in which the fuel gas and the oxidizing gas are electrochemically reacted to generate electricity. Further, the temperature near the central portion of the cell stack 101 in the longitudinal direction of the power generation chamber 215 is monitored by a temperature measuring unit (temperature sensor, thermocouple, etc.) (not shown), and is approximately 700 during steady operation of the fuel cell module 201. It becomes a high temperature atmosphere of ℃ to 1000 ℃.

The fuel gas supply header 217 is a region defined by the hollow upper casing 229a, and is communicated with the fuel gas supply branch pipe 207a in the fuel gas supply hole 231a provided in the upper part of the upper casing 229a. Further, the upper casing 229a has a hole on the lower surface through which the end portion of the cell stack 101 is inserted, and is tightly joined to the end portion of the cell stack 101 via a seal member 237a. The holes have a plurality of holes corresponding to the number of cell stacks 101 provided in the fuel cell cartridge 203, and the cell stacks 101 are inserted into the holes, respectively. The fuel gas supply header 217 guides the fuel gas supplied from the fuel gas supply branch pipe 207a through the fuel gas supply hole 231a from the ends of the plurality of cell stacks 101 into the base pipe 103 at a substantially uniform flow rate. The power generation performance of the plurality of cell stacks 101 is made substantially uniform.

The fuel gas discharge header 219 is a region defined by the hollow lower casing 229b, and is communicated with the fuel gas discharge branch pipe 209a in the fuel gas discharge hole 231b provided in the lower part of the lower casing 229b. Further, the lower casing 229 has a hole on the upper surface through which the end portion of the cell stack 101 is inserted, and is tightly joined to the end portion of the cell stack 101 via a seal member 237b. The holes have a plurality of holes corresponding to the number of cell stacks 101 provided in the fuel cell cartridge 203, and the cell stacks 101 are inserted into the holes, respectively. The fuel gas discharge header 219 passes through the inside of the base pipe 103 of the plurality of cell stacks 101, aggregates the exhaust fuel gas supplied from the end to the fuel gas discharge header 219, and passes through the fuel gas discharge hole 231b. It leads to the fuel gas discharge branch pipe 209a.

Oxidizing gas having a predetermined gas composition and a predetermined flow rate is branched into the oxidizing gas supply branch pipe 211a according to the amount of power generation of the fuel cell module 201, and is supplied to the plurality of fuel cell cartridges 203. The oxidizing gas supply header 221 is a region surrounded by the upper surface of the lower casing 229b and the first lower heat insulating body 227c that defines the lower side of the power generation chamber 215, and the oxidizing gas supply hole 233a provided on the side surface thereof. Is communicated with the oxidizing gas supply branch pipe 211a. The oxidizing gas supply header 221 transfers the oxidizing gas of a predetermined flow rate supplied from the oxidizing gas supply branch pipe 211a through the oxidizing gas supply hole 233a to the power generation chamber via the oxidizing gas supply gap 235a described later. It leads to 215.

The oxidizing gas discharge header 223 is a region surrounded by the lower surface of the upper casing 229a and the first upper heat insulating body 227a defining the upper side of the power generation chamber 215, and the oxidizing gas discharge hole 233b provided on the side surface thereof. Is communicated with the oxidizing gas discharge branch pipe 211b. The oxidizing gas discharge header 223 transfers the oxidative gas supplied from the power generation chamber 215 to the oxidative gas discharge header 223 via the oxidative gas discharge gap 235b, which will be described later, through the oxidative gas discharge hole 233b. It leads to the oxidizing gas discharge branch pipe 211b.

The heat insulating member defines the power generation chamber 215 at least partially, and the first upper heat insulating body 227a, the second upper heat insulating body 227b, the first lower heat insulating body 227c, the second lower heat insulating body 227d, and the first side. Includes a square insulation 227e and a second lateral insulation 227f. Note that FIG. 3 shows an example of the layout of each heat insulating body constituting the heat insulating member 227, but this is not necessarily the case. Further, in the following description, the first upper heat insulating body 227a, the second upper heat insulating body 227b, the first lower heat insulating body 227c, the second lower heat insulating body 227d, the first side heat insulating body 227e and the second side heat insulating body 227f Are collectively referred to as "insulation member 227".

The first upper heat insulating body 227a is arranged on the lower side of the upper casing 229a and is fixed to the first side heat insulating body 227e fixed to the side plate of the upper casing 229a. Further, the first upper heat insulating body 227a is provided with a plurality of holes corresponding to the number of cell stacks 101 provided in the fuel cell cartridge 203. The diameter of this hole is set to be larger than the outer diameter of the cell stack 101. The first upper heat insulating body 227a includes an oxidizing gas discharge gap 235b formed between the inner surface of the hole and the outer surface of the cell stack 101 inserted through the first upper heat insulating body 227a.

Further, the first upper heat insulating body 227a is arranged so as to partition the power generation chamber 215 and the oxidizing gas discharge header 223. Further, the first upper heat insulating body 227a guides the oxidative gas that has passed through the power generation chamber 215 and exposed to high temperature to the oxidative gas discharge header 223 by passing through the oxidative gas discharge gap 235b.

According to the present embodiment, due to the structure of the fuel cell cartridge 203 described above, the fuel gas and the oxidizing gas flow toward the inside and the outside of the cell stack 101. As a result, the oxidative gas exchanges heat with the fuel gas supplied to the power generation chamber 215 through the inside of the base tube 103, and the upper casing 229a and the like made of a metal material are deformed such as buckling. It is cooled to a temperature that does not allow it to be supplied to the oxidizing gas discharge header 223. Further, the fuel gas is heated by heat exchange with the oxidative gas discharged from the power generation chamber 215 and supplied to the power generation chamber 215. As a result, the fuel gas preheated to a temperature suitable for power generation can be supplied to the power generation chamber 215 without using a heater or the like.

The second upper heat insulating body 227b is arranged on the upper side of the upper casing 229a so as to be substantially parallel to the top plate of the upper casing 229a, and is fixed to the first side heat insulating body 227e fixed to the side plate of the upper casing 229a. Has been done. Further, the second upper heat insulating body 227b is provided with an opening for communicating the fuel gas supply branch pipe 207a connected to the fuel gas supply hole 231a provided in the upper part of the upper casing 229a.

The first lower heat insulating body 227c is arranged on the upper side of the lower casing 229b, is arranged so as to be substantially parallel to the bottom plate of the lower casing 229b, and is attached to the first side heat insulating body 227e fixed to the side plate of the lower casing 229b. It is fixed. Further, the first lower heat insulating body 227c is provided with a plurality of holes corresponding to the number of cell stacks 101 provided in the fuel cell cartridge 203. The diameter of this hole is set to be larger than the outer diameter of the cell stack 101. The first lower heat insulating body 227c includes an oxidizing gas supply gap 235a formed between the inner surface of the hole and the outer surface of the cell stack 101 inserted through the first lower heat insulating body 227c.

Further, the first lower heat insulating body 227c is arranged so as to partition the power generation chamber 215 and the oxidizing gas supply header 221. Further, the first lower heat insulating body 227c guides the oxidizing gas supplied to the oxidizing gas supply header 221 to the power generation chamber 215 through the oxidizing gas supply gap 235a.

The second lower heat insulating body 227d is arranged below the lower casing 229b so as to be substantially parallel to the bottom plate of the lower casing 229b, and is fixed to the first lateral heat insulating body 227e fixed to the side plate of the lower casing 229b. ing. Further, the second lower heat insulating body 227d is provided with an opening for communicating the fuel gas discharge branch pipe 209a connected to the fuel gas discharge hole 231b provided in the lower part of the lower casing 229b.

The first lateral heat insulating body 227e is provided on the side of the power generation chamber 215 with respect to the extending direction of the cell stack 101. Further, the first side heat insulating body 227e is provided between the upper casing 229a and the lower casing 229b, and both ends thereof are fixed to the first upper heat insulating body 227a and the first lower heat insulating body 227c, respectively, and the upper casing 229a and the upper casing 229a It is fixed to the side plate of the lower casing 229b. Further, the first lateral heat insulating body 227e has a closed cross-sectional shape in a plane perpendicular to the extending direction of the cell stack 101 so as to surround the power generation chamber 215 over the entire circumference.

The second side heat insulating body 227f is provided outside the first side heat insulating body 227e when viewed from the power generation chamber 215. Further, the second side heat insulating body 227f is provided between the second upper heat insulating body 227b and the second lower heat insulating body 227d, and both ends thereof are fixed to the second upper heat insulating body 227b and the second lower heat insulating body 227d, respectively. There is. Further, the second side heat insulating body 227f has a closed cross-sectional shape in a plane perpendicular to the extending direction of the cell stack 101 so as to surround the first side heat insulating body 227e over the entire circumference.

Further, an outer shell casing 250 for defining the outer shell of the fuel cell cartridge 203 is provided on the outside of the second lower heat insulating body 227d and the second side heat insulating body 227f. The outer shell casing 250 is configured to include a conductive material such as metal. Further, the outer shell casing 250 has a lower surface 251 located outside the second lower heat insulating body 227d and arranged so as to face the pedestal 270 when installed on the grounded pedestal 270.

The outer shell casing 250 of the present embodiment has a bottomed shape in which the outside of the second upper heat insulating body 227b opens upward, but the fuel cell extends to the outside of the second upper heat insulating body 227b. It may be configured to surround the entire cartridge 203.

According to the present embodiment, due to the structure of the fuel cell cartridge 203 described above, the fuel gas and the oxidizing gas flow toward the inside and the outside of the cell stack 101. As a result, the exhaust fuel gas that has passed through the inside of the base pipe 103 and passed through the power generation chamber 215 undergoes heat exchange with the oxidizing gas supplied to the power generation chamber 215 and is supplied to the fuel gas discharge header 219. NS. Further, the oxidizing gas is heated by heat exchange with the exhaust fuel gas and supplied to the power generation chamber 215. As a result, the oxidizing gas heated to the temperature required for power generation can be supplied to the power generation chamber 215 without using a heater or the like.

The DC power generated in the power generation chamber 215 is led out to the lead portion 252 near 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 cell 105, and then the fuel cell cartridge. The current is collected by the current collector rod (not shown) of 203 via the current collector plate (not shown), and is taken out to the outside of each fuel cell cartridge 203. The DC power led out to the outside of the fuel cell cartridge 203 by the current collector rod connects the generated power of each fuel cell cartridge 203 to a predetermined number in series and in parallel, and is led out to the outside of the fuel cell module 201. Then, it is converted into a predetermined AC power by a power conversion device (inverter or the like) such as a power conditioner (not shown) and supplied to a power supply destination (for example, a load facility or a power system).

Here, an outer shell casing 250 is arranged outside each heat insulating member 227 that defines the power generation chamber 215 at least partially, and the heat insulating member 227 and the outer shell casing 250 are in contact with each other. The heat insulating member 227 is made of an insulating material such as silica (SiO ₂ ) or alumina (Al ₂ O ₃ ), and such a heat insulating member 227 is at room temperature (for example, in a temperature range of about 0 ° C. to 40 ° C.). Although it shows good insulation, it may decrease as the temperature rises.

On the other hand, in order to take out the electric power generated in the power generation chamber 215 to the outside, the lead portion 252 including the lead film 115 of the cell stack 101 is moved from the power generation chamber 215 to the outside of the first upper heat insulating body 227a and the first lower heat insulating body 227c. It extends all the way. The lead portion 252 is inserted into the oxidizing gas discharge gap 235b provided in the first upper heat insulating body 227a and the oxidizing gas supply gap 235a provided in the first lower heat insulating body 227c, so that the lead portion 252 is inserted in the oxidizing gas supply gap 235a provided in the first lower heat insulating body 227c. The lead portion 252 is designed so as not to come into contact with the first upper heat insulating body 227a and the first lower heat insulating body 227c. 1 It may come into contact with the upper heat insulating body 227a and the first lower heat insulating body 227c. At this time, if the insulating property of the heat insulating member 227 is deteriorated, a ground fault current may be generated between the lead portion 252 and the outer shell casing 250 due to the potential difference between the two.

In order to solve such a problem, in the present embodiment, when the lead portion 252 comes into contact with the heat insulating member 227, the conductive path formed between the lead portion 252 and the outer shell casing 250 can be blocked at least partially. The insulating member 260 configured in the above is provided. The insulating member 260 is composed of an insulating material having a higher insulating property than the heat insulating member 227 in a temperature range higher than normal temperature, for example, high-purity alumina (Al ₂ O ₃ ), mica, and the like. By blocking the conductive path 254 at least partially by such an insulating member 260, the ground fault current can be effectively suppressed.

In the following description, when the lead portion 252 comes into contact with the heat insulating member 227, the insulating member is configured so as to be able to at least partially block the conductive path formed between the lead portion 252 and the outer shell casing 250. Although 260 will be described, the insulating member 260 may be configured to at least partially block any conductive path formed between the lead portion 252 and the other conductive member. For example, since the upper casing 229a and the lower casing 229b are also made of a conductive material, the insulating member 260 is provided so as to at least partially block the conductive path formed between these conductive members and the lead portion 252. It may be provided.

In some embodiments, the insulating member 260 is provided between the lead portion 252 and the outer shell casing 250 (in other words, at least the insulating member 260 on a straight line connecting the lead portion 252 and the outer shell casing 250). Some are arranged so that they intersect). By arranging the insulating member 260 in this way, the conductive path can be effectively blocked.

In the embodiment shown in FIG. 3, the insulating member 260 is provided between the outer shell casing 250 and the heat insulating member. More specifically, the insulating member 260 is provided along the boundary between the inner wall surface of the outer shell casing 250 and the second lateral heat insulating body 227f. By arranging the insulating member 260 between the outer shell casing 250 adjacent to each other and the second side heat insulating body 227f in this way, the conductive path can be effectively blocked.

Further, the insulating member 260 of FIG. 3 covers the corner portions C1 and C2 in the vicinity of the opening through which the oxidizing gas supply branch pipe 221a and the oxidizing gas discharge branch pipe 221b of the second side heat insulating body 227f are inserted. May be formed in. As a result, the insulating member 260 can be interposed up to the surface where the second side heat insulating body 227f comes into contact with the oxidizing gas supply branch pipe 221a and the oxidizing gas discharging branch pipe 221b, and the conductive path can be more effectively performed. Can be blocked.

FIG. 4 is a first modification of FIG. FIG. 5 is a second modification of FIG. FIG. 6 is a third modification of FIG. In the first modification to the third modification, the insulating member 260 is provided between a plurality of heat insulating bodies constituting the heat insulating member 227. By interposing the insulating member 260 between the plurality of heat insulating bodies constituting the heat insulating member 227 in this way, the conductive path formed between the lead portion 252 and the outer shell casing 250 can be effectively blocked.

In the first modification shown in FIG. 4, the insulating member 260 is provided between the first side heat insulating body 227e and the second side heat insulating body 227f. As described above, in the first modification, the insulating member 260 is interposed between the plurality of heat insulating bodies laminated along the inner and outer directions when viewed from the power generation chamber 215, so that the lead portion 252 and the outer shell casing 250 are separated from each other. The conductive path formed in the can be effectively blocked.

Further, the insulating member 260 of FIG. 4 may be formed so as to cover the corner portions C3 and C4 of the first side heat insulating body 227e at the upper end portion and the lower end portion of the first side heat insulating body 227e. As a result, the insulating member 260 can be interposed on the surface where the first lateral heat insulating body 227e comes into contact with the constituent members of the oxidizing gas supply hole 233a and the oxidizing gas discharge hole 233b, and the conductive path can be more effectively provided. It can be blocked.

In the second modification shown in FIG. 5, the insulating member 260 is between the first upper heat insulating body 227a and the first side heat insulating body 227e, and the first lower heat insulating body 227c and the first side heat insulating body 227e. It is provided between each. That is, the upper connecting portion 272a in which the first upper heat insulating body 227a and the first side heat insulating body 227e are fixed to each other, and the lower connecting portion 227c in which the first lower heat insulating body 227c and the first side heat insulating body 227e are fixed to each other. In the portion 272b, the insulating member 260 is arranged so as to intervene. As described above, in the second modification, by arranging the insulating member 260 in the upper connecting portion 272a and the lower connecting portion 272b, the conductive path formed between the lead portion 252 and the outer shell casing 250 is effectively provided. Can be blocked.

In the third modification shown in FIG. 6, the insulating member 260 is arranged in the upper connecting portion 272a and the lower connecting portion 272b as in FIG. On the other hand, in FIG. 6, the upper connecting portion 272a has a substantially L-shape in a cross section passing through the central axis of the power generation chamber 215 along the axial direction of the cell stack 101, and the insulating member 260 has such an upper connecting portion 272a. It is provided along. By forming the upper connecting portion 272a in a substantially L shape in this way, the facing area between the first upper heat insulating body 227a and the first lateral heat insulating body 227e in the upper connecting portion 272a increases. By providing the insulating member 260 along the upper connecting portion 272a in which the facing area is increased in this way, the conductive path formed between the lead portion 252 and the outer shell casing 250 can be effectively blocked.

Further, the lower connecting portion 272b has a substantially L-shape in a cross section passing through the central axis of the power generation chamber 215 along the axial direction of the cell stack 101, and the insulating member 260 is provided along such a lower connecting portion 272b. By forming the lower connecting portion 272b in a substantially L shape in this way, the facing area between the first lower heat insulating body 227c and the first lateral heat insulating body 227e in the lower connecting portion 272b increases. By providing the insulating member 260 along the lower connecting portion 272b in which the facing area is increased in this way, the conductive path formed between the lead portion 252 and the outer shell casing 250 can be effectively blocked.

FIG. 7 is a fourth modification of FIG. In the fourth modification, the insulating member 260 is formed so as to cover the lower surface 251 of the outer shell casing 250. As a result, when the fuel cell cartridge is installed on the gantry 270, the lead portion 252 and the outer shell casing 250 are connected by interposing the insulating member 260 between the lower surface 251 of the outer shell casing 250 and the gantry 270. The conductive path formed between them can be effectively blocked.

Further, in FIG. 7, the insulating member 260a is provided so as to be interposed in the middle of the fuel gas supply branch pipe 207a connected to the fuel gas supply hole 231a. Further, an insulating member 260b is provided in the middle of the fuel gas discharge branch pipe 209a connected to the fuel gas discharge hole 231b. Further, an insulating member 260c is provided in the middle of the oxidizing gas supply branch pipe 211a connected to the oxidizing gas supply hole 233a. Further, an insulating member 260d is provided in the middle of the oxidizing gas discharge branch pipe 211b connected to the oxidizing gas discharge hole 233b. By arranging the insulating members 260a to 260d in this way, the conductive path formed between the lead portion 252 and the outer shell casing 250 can be effectively blocked.

As described above, according to the above-described embodiment, when the lead portion 252 electrically connected to the fuel cell in a temperature range higher than normal temperature comes into contact with the heat insulating member 227, the lead portion 252 and the conductive member are separated from each other. The conductive path formed in is at least partially blocked by the insulating member 260. As a result, the ground fault current flowing through the conductive path formed between the lead portion 252 and the heat insulating member 227 is suppressed, so that the output voltage of the fuel cell cartridge can be improved. As a result, a high output fuel cell module can be realized.

In addition, it is possible to replace the components in the above-described embodiments with well-known components as appropriate without departing from the spirit of the present disclosure, and the above-described embodiments may be combined as appropriate.

The contents described in each of the above embodiments are grasped as follows, for example.

(1) The fuel cell cartridge according to at least one embodiment of the present disclosure is
A power generation chamber (for example, a power generation chamber 215 of the above embodiment) including a fuel cell constituting a cell stack (for example, the cell stack 101 of the above embodiment) and a power generation chamber (for example, the power generation chamber 215 of the above embodiment).
A heat insulating member that at least partially defines the power generation chamber (for example, the heat insulating member 227 of the above embodiment) and
A conductive member (for example, the outer shell casing 250 of the above embodiment) provided outside the heat insulating member when viewed from the power generation chamber, and
It has a higher insulating property than the heat insulating member in a temperature range higher than normal temperature, and when the lead portion of the cell stack (for example, the lead portion 252 of the above embodiment) comes into contact with the heat insulating member when it is in the high temperature range, the lead portion An insulating member (for example, the insulating member 260 of the above embodiment) configured to at least partially block the conductive path formed between the conductive member and the conductive member.
To be equipped.

According to the aspect (1) above, when the lead portion electrically connected to the fuel cell in a temperature range higher than room temperature comes into contact with the heat insulating member, the conductive path formed between the lead portion and the conductive member. Is at least partially blocked by the insulating member. As a result, the ground fault current flowing through the conductive path formed between the lead portion and the heat insulating member is suppressed, so that the output voltage of the fuel cell cartridge can be improved.

(2) In one aspect, in the above aspect (1),
The insulating member is provided between the lead portion and the conductive member when the lead portion comes into contact with the heat insulating member.

According to the aspect (2) above, by arranging the insulating member between the heat insulating member and the conductive member, the conductive path formed between the lead portion and the conductive member can be effectively blocked.

(3) In one aspect, in the above aspect (1) or (2),
The insulating member is provided between the conductive member and the heat insulating member.

According to the aspect (3) above, by arranging the insulating member between the conductive member and the heat insulating member adjacent to each other, the conductive path formed between the lead portion and the conductive member can be effectively blocked. ..

(4) In one aspect, in the above aspect (3),
The conductive member is an outer shell casing that defines the outer shell of the fuel cell cartridge.
The insulating member is formed along the inner wall surface of the outer shell casing.

According to the aspect (4) above, by providing the insulating member along the inner wall surface of the outer shell casing, the conductive path formed between the lead portion and the outer shell casing can be effectively blocked.

(5) In one aspect, in the above aspect (1) or (2),
The insulating member is provided between a plurality of heat insulating bodies constituting the heat insulating member.

According to the aspect (5) above, by interposing the insulating member between the plurality of heat insulating bodies constituting the heat insulating member, the conductive path formed between the lead portion and the conductive member can be effectively blocked. ..

(6) In one aspect, in the above aspect (5),
The plurality of heat insulators
A first side heat insulating body (for example, the first side heat insulating body 227e of the above embodiment) provided on the side of the power generation chamber with respect to the extending direction of the cell stack, and
A second side heat insulating body (for example, the second side heat insulating body 227f of the above embodiment) arranged outside the first side heat insulating body when viewed from the power generation chamber, and
Including
The insulating member is provided between the first side heat insulating body and the second side heat insulating body.

According to the aspect (6) above, the lead portion and the lead portion are formed by interposing an insulating member between the first side heat insulating body and the second side heat insulating body which are laminated along the inner and outer directions when viewed from the power generation chamber. The conductive path formed between the conductive member and the conductive member can be effectively blocked.

(7) In one aspect, in the above aspect (5),
The plurality of heat insulators
A first side heat insulating body (for example, the first side heat insulating body 227e of the above embodiment) provided on the side of the power generation chamber with respect to the extending direction of the cell stack.
A first upper heat insulating body (for example, the first upper heat insulating body 227a of the above embodiment) provided above the power generation chamber so as to intersect in the extending direction of the cell stack, and
A first lower heat insulating body (for example, the first lower heat insulating body 227c of the above embodiment) provided below the power generation chamber so as to intersect in the extending direction of the cell stack.
Including
The insulating member is provided between the first lateral heat insulating body and the first upper heat insulating body or the first lower heat insulating body.

According to the aspect (7) above, by providing an insulating member between the first lateral heat insulating body and the first upper heat insulating body or the first lower heat insulating body, it is formed between the lead portion and the conductive member. Can effectively block the conductive path.

(8) In one aspect, in the above aspect (7),
The connecting portion between the first lateral heat insulating body and the first upper heat insulating body or the first lower heat insulating body (for example, the upper connecting portion 272a or the lower connecting portion 272b of the above embodiment) is in the extending direction of the cell stack. It has a substantially L-shape in a cross section passing through the central axis of the power generation chamber along the above.
The insulating member is provided along the connecting portion.

According to the aspect (8) above, the connecting portion between the first lateral heat insulating body and the first upper heat insulating body or the first lower heat insulating body is formed in a substantially L shape, and the insulating member is formed along the connecting portion. Provided. By forming the connecting portion in a substantially L shape in this way, the contact area between the two at the connecting portion increases. Then, by providing the insulating member along the connecting portion having an increased area in this way, the conductive path formed between the lead portion and the conductive member can be effectively blocked.

(9) In one aspect, in any one of the above (1) to (8),
The conductive member is a casing (for example, the outer shell casing 250 of the above embodiment) that defines the outer shell of the fuel cell cartridge.
The insulating member is formed so as to cover the lower surface of the casing (for example, the lower surface 251 of the above embodiment).

According to the aspect (9) above, the insulating member is provided so as to cover the lower surface of the outer shell casing that defines the outer shell of the fuel cell cartridge. As a result, when the fuel cell cartridge is installed on the gantry, an insulating member is interposed between the lower surface of the casing and the gantry, so that the conductive path formed between the reed portion and the conductive member is effective. Can be blocked.

(10) In one aspect, in any one of the above (1) to (9),
The insulating member includes a fuel gas supply branch pipe (for example, the fuel gas supply branch pipe 207a of the above embodiment) connected to a fuel gas supply hole for supplying fuel gas to the cell stack, and the fuel gas from the cell stack. Connected to a fuel gas discharge branch pipe (for example, the fuel gas discharge branch pipe 209a of the above embodiment) connected to a fuel gas discharge hole for discharging the celstac, and an oxidizing gas supply hole for supplying the oxidative gas to the cell stac. Oxidizing gas supply branch pipe (for example, the oxidizing gas supply branch pipe 211a of the above embodiment) or an oxidizing gas connected to the oxidizing gas discharge hole for discharging the oxidizing gas from the cell stack. It is provided in at least one of the discharge branch pipes (for example, the oxidizing gas discharge branch pipe 211b of the above embodiment).

According to the aspect (10) above, by arranging the insulating member in at least one of the fuel gas supply branch pipe, the fuel gas discharge branch pipe, the oxidizing gas supply branch pipe, or the oxidizing gas discharge branch pipe, The conductive path formed between the lead portion and the conductive member can be effectively blocked.

(11) The fuel cell module according to at least one embodiment of the present disclosure is
At least one fuel cell cartridge according to any one of the above (1) to (10) is provided.

According to the aspect (11) above, a fuel cell module having a high output can be realized by providing a fuel cell cartridge having a high output voltage.

101 Cell stack 103 Base tube 105 Fuel cell cell 107 Interconnector 109 Fuel pole 111 Solid electrolyte membrane 113 Air pole 115 Lead membrane 201 Fuel cell module 203 Fuel cell cartridge 205 Pressure vessel 207 Fuel gas supply pipe 207a Fuel gas supply branch pipe 209 Fuel Gas discharge pipe 209a Fuel gas discharge branch pipe 211a Oxidizing gas supply branch pipe 211b Oxidizing gas discharge branch pipe 215 Power generation room 217 Fuel gas supply header 219 Fuel gas discharge header 221 Oxidizing gas supply header 221 Supply header 223 Oxidizing gas discharge Header 227 Insulation member 227a First upper insulation 227b Second upper insulation 227c First lower insulation 227d Second lower insulation 227e First side insulation 227f Second side insulation 229b Lower casing 229a Upper casing 231a Fuel Gas supply hole 231b Fuel gas discharge hole 233a Oxidizing gas supply hole 233b Oxidizing gas discharge hole 235a Oxidizing gas supply gap 235b Oxidizing gas discharge gap 237a, 237b Seal member 250 Outer shell casing 251 Bottom surface 252 Lead part 254 Conductive path 260 Insulating member 270 Stand 272a Upper connecting part 272b Lower connecting part

Claims (11)

A power generation room containing fuel cell cells that make up the cell stack,
With a heat insulating member that at least partially defines the power generation chamber,
A conductive member provided outside the heat insulating member when viewed from the power generation chamber, and
It has higher insulating properties than the heat insulating member in a temperature range higher than normal temperature, and when the lead portion of the cell stack comes into contact with the heat insulating member when it is in the high temperature range, it is formed between the lead portion and the conductive member. An insulating member configured to at least partially block the conductive path
A fuel cell cartridge. The fuel cell cartridge according to claim 1, wherein the insulating member is provided between the lead portion and the conductive member when the lead portion comes into contact with the heat insulating member. The fuel cell cartridge according to claim 1 or 2, wherein the insulating member is provided between the conductive member and the heat insulating member. The conductive member is an outer shell casing that defines the outer shell of the fuel cell cartridge.
The fuel cell cartridge according to claim 3, wherein the insulating member is formed along the inner wall surface of the outer shell casing. The fuel cell cartridge according to claim 1 or 2, wherein the insulating member is provided between a plurality of heat insulating bodies constituting the heat insulating member. The plurality of heat insulators
A first lateral heat insulating body provided on the side of the power generation chamber with respect to the extending direction of the cell stack,
A second side heat insulating body arranged outside the first side heat insulating body when viewed from the power generation chamber, and a second side heat insulating body.
Including
The fuel cell cartridge according to claim 5, wherein the insulating member is provided between the first side heat insulating body and the second side heat insulating body. The plurality of heat insulators
A first lateral heat insulating body provided on the side of the power generation chamber with respect to the extending direction of the cell stack,
A first upper heat insulating body provided above the power generation chamber so as to intersect in the extending direction of the cell stack,
A first lower heat insulating body provided below the power generation chamber so as to intersect in the extending direction of the cell stack,
Including
The fuel cell cartridge according to claim 5, wherein the insulating member is provided between the first lateral heat insulating body and the first upper heat insulating body or the first lower heat insulating body. The connecting portion between the first lateral heat insulating body and the first upper heat insulating body or the first lower heat insulating body has a substantially L shape in a cross section passing through the central axis of the power generation chamber along the extending direction of the cell stack. Has a shape,
The fuel cell cartridge according to claim 7, wherein the insulating member is provided along the connecting portion. The conductive member is a casing that defines the outer shell of the fuel cell cartridge.
The fuel cell cartridge according to any one of claims 1 to 8, wherein the insulating member is formed so as to cover the lower surface of the casing. The insulating member is connected to a fuel gas supply branch pipe connected to a fuel gas supply hole for supplying fuel gas to the cell stack, and a fuel gas discharge hole for discharging the fuel gas from the cell stack. A fuel gas discharge branch pipe, an oxidizing gas supply branch pipe connected to an oxidizing gas supply hole for supplying the oxidizing gas to the cell stack, or an oxidizing for discharging the oxidizing gas from the cell stack. The fuel cell cartridge according to any one of claims 1 to 9, which is provided in at least one of the oxidizing gas discharge branch pipes connected to the gas discharge hole. A fuel cell module comprising at least one fuel cell cartridge according to any one of claims 1 to 10.

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