WO2014064859A1

WO2014064859A1 - Fuel cell system and method for manufacturing same

Info

Publication number: WO2014064859A1
Application number: PCT/JP2013/003426
Authority: WO
Inventors: 徹壽川; 鵜飼　邦弘; 谷口　昇
Original assignee: パナソニック株式会社
Priority date: 2012-10-25
Filing date: 2013-05-30
Publication date: 2014-05-01
Also published as: JP6195123B2; JP6583752B2; JP6369771B2; JPWO2014064859A1; JP2017228536A; JP2018113260A

Abstract

This fuel cell system is provided with: an impurity removal device (3) for removing impurities that are contained in a starting material gas; an evaporator (9) for producing water vapor by evaporating water supplied thereto; a reformer (4) for producing a reformed gas, which serves as a fuel, by means of a reforming reaction between the water vapor produced by the evaporator (9) and the starting material gas from which impurities are removed by the impurity removal device (3); a fuel cell (6) which generates power by means of a power generation reaction utilizing the fuel and air supplied thereto; a combustion unit (23) for combusting some fuel that has been unused in the fuel cell (6); a case (7) for housing the evaporator (9), the reformer (4), the fuel cell (6) and the combustion unit (23); an exhaust gas passage (20) where an exhaust gas produced by the combustion in the combustion unit (23) passes through in order to be discharged from the inside of the case (7) to the outside of the system; and a housing space which is provided midway along the exhaust gas passage (20) so as to constitute a part of the exhaust gas passage (20), and in which the impurity removal device (3) is arranged.

Description

Fuel cell system and manufacturing method thereof

The present invention relates to a fuel cell system including an impurity remover for removing impurities contained in a raw material gas, and a method for manufacturing the fuel cell system.

In a fuel cell system using hydrocarbons as a raw material gas, for example, steam reforming using steam is used to reform the raw material gas. A steam reforming catalyst is used to promote this steam reforming, but the raw material gas contains, for example, a sulfur compound as an odorant, and these steam reforming catalysts are deteriorated by these. There is a fear. Therefore, in order to prevent deterioration of the steam reforming catalyst, a desulfurizer that reduces the sulfur compound contained in the raw material gas is used.

As such a desulfurizer, for example, a sulfur compound is reacted with hydrogen on a catalyst (Ni—Mo system, Co—Mo system) to convert it into hydrogen sulfide, and the hydrogen sulfide is taken into zinc oxide and removed. Examples thereof include a hydrodesulfurization apparatus that performs desulfurization by a so-called hydrodesulfurization method.

The hydrodesulfurization apparatus requires hydrogen when desulfurization is performed by the hydrodesulfurization method, and requires temperature control suitable for the desulfurization reaction. Therefore, a fuel cell system having a configuration for controlling the temperature of the desulfurizer has been proposed (for example, Patent Documents 1 to 3).

More specifically, in Patent Document 1, the desulfurizer 110 is heated by heat transfer such as radiant heat discharged from the fuel cell stack 104 or the reformer 103 as shown in FIG. Further, the temperature of the desulfurizer 110 is controlled by selecting the gas (cooling gas or heating gas) to be circulated by the control device and adjusting the flow rate so that the temperature of the desulfurizer 110 becomes 100 to 300 ° C.

Further, in Patent Document 2, as shown in FIG. 25, a desulfurizer 202 is installed between the heat insulating tank 201 and the internal housing 216, and the desulfurizer 202 is heated by propagation of combustion heat released from the combustor 207.

In Patent Document 3, as shown in FIG. 26, a desulfurizer 301 is provided outside a high-temperature heat insulating portion provided so that the inside is kept at a high temperature. And it is comprised so that the desulfurizer 301 may be maintained in a predetermined | prescribed temperature range using the waste heat of the solid oxide fuel cell which propagates through a high temperature heat insulation part.

Also, a fuel cell system that heats the desulfurizer using high-temperature exhaust gas generated from the fuel cell has been proposed (for example, Patent Documents 4 and 5). In the fuel cell system (SOFC system) of Patent Document 4, the fuel cell 430 is accommodated and the high-temperature exhaust gas discharged from the fuel cell 430 is shielded from the outside, or as shown in FIG. Further, a configuration in which a desulfurizer 411 is housed in a heating chamber 400 provided separately from the combustion chamber 420 is disclosed. In the fuel cell system of Patent Document 4, the desulfurizer 411 in the combustion chamber 420 or the heating chamber 400 is heated by exhaust gas.

Further, in Patent Document 5, as shown in FIG. 28, in a housing (housing) 500, a preheater 501 that heats a raw material gas, an oxidant gas, and water, and a reformer that performs steam reforming on the raw material gas. A fuel cell system that houses a mass device 502 and a fuel cell main body 503 is disclosed. In the fuel cell system of Patent Document 5, the exhaust gas discharged from the fuel cell main body 503 is guided to a desulfurizer 504 disposed outside the housing 500, and the desulfurizer 504 is heated.

JP 2010-272333 A JP 2011-216308 A Japanese Patent No. 4911927 JP 2006-309982 A JP 2012-155978 A Japanese Patent No. 2999307 JP 63-44934 A

However, in the fuel cell system disclosed in Patent Document 1, the desulfurizer 110 is heated by heat transfer such as radiant heat discharged from the fuel cell stack 104 or the reformer 103, and therefore the entire desulfurizer is uniformly distributed without temperature unevenness. It is difficult to heat the glass quickly, and it is difficult to prevent overheating. Further, as shown in FIG. 24, there is a problem that switching of a plurality of valves and a control device are separately required. Similarly, the fuel cell systems disclosed in

Patent Documents

2 and 3 are configured to heat the desulfurizer by the propagation of combustion heat released from the combustor as shown in FIGS. Problems similar to Patent Document 1 such as generation of unevenness and excessive temperature rise cannot be avoided.

In addition, as shown in FIG. 27, the fuel cell system (SOFC system) disclosed in Patent Document 4 includes a water heating means 410, a vaporizer 412 and a desulfurizer 411 in the same casing (heating chamber 400). These are provided in close proximity to each other. Here, since the water heating means 410 and the vaporizer 412 consume a large amount of heat to vaporize water and kerosene, the temperature distribution of the exhaust gas in the heating chamber 400 becomes non-uniform. For this reason, there is a problem that it becomes difficult to heat the entire desulfurizer 411 with exhaust gas at a uniform temperature.

In the fuel cell system disclosed in Patent Document 5, exhaust gas is used as a heating source of the desulfurizer 504. However, the entire desulfurizer 504 is not covered with the exhaust gas and heated, and the entire desulfurizer 504 is not heated. There is a problem that it becomes difficult to heat the glass at a uniform temperature.

The present invention has been made in view of the above-described problems, and an object thereof is to provide a fuel cell system capable of heating the entire impurity remover for removing impurities at a uniform temperature and a method for manufacturing the same. There is.

In order to solve the above-described problem, the fuel cell system according to the present invention includes an impurity remover that removes impurities contained in the supplied source gas, and an evaporator that evaporates the supplied water to generate water vapor. A reformer that generates a reformed gas as a fuel by a reforming reaction from the water vapor generated by the evaporator and the source gas from which impurities have been removed by the impurity remover; the supplied air; and A fuel cell that generates power by a power generation reaction using fuel, a combustion unit that burns unused fuel in the fuel cell, and the evaporator, the reformer, the fuel cell, and the combustion unit are accommodated In order to exhaust the exhaust gas generated by the combustion in the housing and the combustion section from the inside of the housing to the outside of the fuel cell system, the exhaust gas passage through which the exhaust gas flows and the exhaust gas in the middle of the exhaust gas route Provided so as to constitute a part of the scan path, and a housing space for placing the impurity remover.

The fuel cell system according to the present invention is configured as described above, and has an effect that the entire impurity remover can be heated at a uniform temperature.

1 is a schematic diagram illustrating an example of a configuration of a fuel cell system according to Embodiment 1. FIG. In the structure of the fuel cell system which concerns on Embodiment 1, it is the schematic diagram which showed the structure at the time of isolate | separating a housing | casing and a container. It is the schematic diagram which showed an example of the structure of the fuel cell system which concerns on the modification of Embodiment 1 of this invention. In the structure of the fuel cell system which concerns on the modification of Embodiment 1, it is the schematic diagram which showed the structure at the time of isolate | separating a housing | casing and a container. 6 is a schematic diagram illustrating an example of a configuration of a fuel cell system according to Embodiment 2. FIG. 6 is a schematic diagram illustrating an example of a configuration of a fuel cell system according to Embodiment 2. FIG. FIG. 5 is a schematic diagram illustrating an example of a configuration of a fuel cell system according to Modification 1 of Embodiment 2. 6 is a schematic diagram illustrating an example of a configuration of a fuel cell system according to Modification 2 of Embodiment 2. FIG. FIG. 10 is a schematic diagram illustrating an example of a configuration of a fuel cell system according to Modification 3 of Embodiment 2. FIG. 10 is a schematic diagram illustrating an example of a configuration of a fuel cell system according to Modification 4 of Embodiment 2. FIG. 10 is a schematic diagram illustrating an example of a configuration of a fuel cell system according to Modification 4 of Embodiment 2. FIG. 10 is a schematic diagram illustrating an example of a configuration of a fuel cell system according to Modification 5 of Embodiment 2. FIG. 10 is a schematic diagram illustrating an example of a configuration of a fuel cell system according to Modification 6 of Embodiment 2. FIG. 10 is a schematic diagram illustrating an example of a configuration of a fuel cell system according to Modification 6 of Embodiment 2. FIG. 10 is a schematic diagram illustrating an example of a configuration of a fuel cell system according to Modification Example 7 of Embodiment 2. 6 is a schematic diagram illustrating an example of a configuration of a fuel cell system according to Embodiment 3. FIG. 6 is a schematic diagram illustrating an example of a configuration of a fuel cell system according to Embodiment 3. FIG. 6 is a schematic diagram illustrating an example of a configuration of a fuel cell system according to Embodiment 3. FIG. FIG. 10 is a schematic diagram illustrating an example of a configuration of a fuel cell system according to a modification example of Embodiment 3. FIG. 10 is a schematic diagram illustrating an example of a configuration of a fuel cell system according to a modification example of Embodiment 3. FIG. 10 is a schematic diagram illustrating an example of a configuration of a fuel cell system according to a modification example of Embodiment 3. FIG. 10 is a diagram illustrating an example of a configuration in which a container is separated from a housing in a fuel cell system according to a modification of the third embodiment. 5 is a flowchart showing an example of a method for manufacturing a fuel cell system according to

Embodiments

1 and 3. It is a schematic diagram which shows a prior art and shows an example of a structure of a fuel cell system. It is a schematic diagram which shows a prior art and shows an example of a structure of a fuel cell system. It is a schematic diagram which shows a prior art and shows an example of a structure of a fuel cell system. It is a schematic diagram which shows a prior art and shows an example of a structure of a fuel cell system. It is a schematic diagram which shows a prior art and shows an example of a structure of a fuel cell system.

The present invention provides the following aspects.

The fuel cell system according to the first aspect of the present invention includes an impurity remover that removes impurities contained in a supplied raw material gas, an evaporator that evaporates supplied water to generate water vapor, and the evaporator A reformer that generates a reformed gas to be a fuel by a reforming reaction from the water vapor generated by the impurity and the source gas from which impurities have been removed by the impurity remover, and the supplied air and the fuel are used A fuel cell that generates power by a power generation reaction, a combustion unit that burns unused fuel in the fuel cell, a housing that houses the evaporator, the reformer, the fuel cell, and the combustion unit; In order to exhaust the exhaust gas generated by the combustion in the combustion section from the inside of the housing to the outside of the fuel cell system, an exhaust gas path through which the exhaust gas flows and a part of the exhaust gas path are formed in the middle of the exhaust gas path. Provided to, and a housing space for placing the impurity remover.

Here, the accommodation space provided in the exhaust gas path is formed by, for example, a container that is provided to communicate with the exhaust gas path in the middle of the exhaust gas path (arbitrary position) and that can accommodate the impurity remover. It may be a space. Alternatively, if the path cross section of the exhaust gas path is sufficiently large to accommodate the impurity remover, a space formed by the exhaust gas path itself may be used.

According to the above-described configuration, since the impurity remover is disposed in the accommodating space provided in the middle of the exhaust gas path, the entire impurity remover can be covered with the exhaust gas generated in the combustion section and heated. Here, the exhaust gas guided to the impurity remover is heat-utilized by the evaporator and the reformer accommodated in the casing, and is in a predetermined temperature range when leaving the casing. . In addition, the temperature unevenness in the exhaust gas is eliminated at the time of exiting from the housing. Therefore, the entire impurity remover can be heated by the exhaust gas in a predetermined temperature range without temperature unevenness.

Therefore, the fuel cell system according to the first aspect of the present invention has the effect that the entire impurity remover can be heated at a uniform temperature.

Further, in the fuel cell system according to the second aspect of the present invention, in the first aspect described above, the impurity remover may be a desulfurizer that removes a sulfur component as an impurity from the raw material gas.

According to the above configuration, since the impurity remover is a desulfurizer, it is possible to remove a sulfur component that causes deterioration of the catalyst as an impurity contained in the raw material gas.

The fuel cell system according to a third aspect of the present invention is the fuel cell system according to the second aspect described above, wherein a raw material gas path for circulating the raw material gas to supply the raw material gas to the desulfurizer, A recycle path for guiding gas to the source gas path, and the desulfurizer uses the hydrogen-containing gas flowing through the source gas path to remove sulfur components as impurities from the source gas by hydrodesulfurization. It may be configured to be removed. According to the above configuration, since the desulfurizer can remove the sulfur component from the raw material gas by the hydrodesulfurization, the sulfur component can be removed with high efficiency.

The fuel cell system according to a fourth aspect of the present invention is the fuel cell system according to the third aspect, wherein a part of the reformed gas generated by the reformer circulates in the recycling path as the hydrogen-containing gas. It may be configured as follows.

According to the configuration described above, the reformed gas that is a hydrogen-containing gas can be guided to the raw material gas path. For example, when the remover is a desulfurizer that performs hydrodesulfurization, it is necessary for this hydrodesulfurization. Hydrogen can be supplied.

Further, in the fuel cell system according to the fifth aspect of the present invention, in any one of the first to fourth aspects described above, the impurity remover may have a flat plate shape. Since the impurity remover has a flat plate shape, the impurity remover disposed in the exhaust gas path can be covered substantially uniformly with the exhaust gas discharged from the casing. For this reason, the impurity remover can be heated with exhaust gas without temperature unevenness.

The fuel cell system according to a sixth aspect of the present invention is the fuel cell system according to any one of the first to fifth aspects, wherein the exhaust gas is cooled by heat exchange between the air supplied to the fuel cell and the exhaust gas. An air heat exchanger may be provided in the housing.

According to the configuration described above, since the air heat exchanger is provided, the temperature of the exhaust gas from the combustion section can be adjusted to an appropriate temperature in the casing. For this reason, the impurity remover can be heated at an appropriate temperature by heat exchange with the exhaust gas adjusted to an appropriate temperature.

In addition, a fuel cell system according to a seventh aspect of the present invention includes, in any one of the first to sixth aspects described above, a storage device that forms the storage space for disposing the impurity remover. The container may be configured to be connected to the housing.

According to the above configuration, since the storage device for forming the storage space for storing the impurity remover is provided, it is easy to control the temperature of the impurity remover disposed in the storage device with the exhaust gas flowing through the exhaust gas path. Become. In addition, since the impurity remover can be stored and managed in the container, the impurity remover can be easily managed.

In addition, the fuel cell system according to the eighth aspect of the present invention may be configured such that in the seventh aspect described above, the container can be attached to and detached from the housing.

According to the above-described configuration, the manufacturing process for attaching the container to the housing becomes easy, and it becomes easy to remove the container from the housing when replacement is necessary for maintenance or the like.

The fuel cell system according to a ninth aspect of the present invention is the fuel cell system according to any one of the first to eighth aspects, wherein the housing includes at least the evaporator, the reformer, the fuel cell, and the fuel cell system. You may be comprised so that the 1st housing | casing which accommodates a combustion part and the 2nd housing | casing surrounding the outer periphery of said 1st housing | casing may be provided.

According to the configuration described above, since the wall can be provided twice with the first casing and the second casing, heat radiation from the inside of the casing to the outside can be suppressed.

In the fuel cell system according to the tenth aspect of the present invention, in the ninth aspect described above, a heat insulating material is accommodated in at least a part between the first casing and the second casing. May be.

According to the configuration described above, since the heat insulating material is accommodated between the first housing and the second housing, heat radiation from the inside of the housing to the outside can be further reliably suppressed.

A fuel cell system manufacturing method according to an eleventh aspect of the present invention includes a fuel cell that generates power by a power generation reaction using supplied air and fuel generated from a raw material gas, and is not used in the fuel cell. A combustion section that burns the fuel, an impurity remover that removes impurities contained in the raw material gas using the heat held in the exhaust gas generated by the combustion in the combustion section, and water vapor that evaporates the supplied water An evaporator to be generated, a reformer that generates a reformed gas as a fuel by a reforming reaction from water vapor generated by the evaporator and a raw material gas from which impurities have been removed by the impurity remover, and the fuel A casing housing the battery, the combustion section, the evaporator, and the reformer; and exhaust gas generated by combustion in the combustion section is discharged from the casing to the outside of the fuel cell system. Therefore, the exhaust gas path through which the exhaust gas circulates and is detachable from the housing, and is provided so as to constitute a part of the exhaust gas path in the middle of the exhaust gas path, and the impurity remover is disposed And a container for housing the impurity remover in a state where the impurity remover is removed from the housing. A first step of heating, a second step of reducing the catalyst filled in the impurity remover, and a third step of attaching the container to the housing.

According to the above-described method, the step of performing the heating and reduction treatment necessary for activating the catalyst filled in the impurity remover, that is, the first step and the second step are performed, and the impurity remover is provided in the casing. Can be done before installation. Therefore, it is not necessary to add components to the impurity removal device or the container other than the container that contains the impurity removal device in the heating and reduction process, and an efficient fuel cell system manufacturing method can be realized without using wasted energy. It becomes.

(Embodiment 1)
Hereinafter, an embodiment (Embodiment 1) of the present invention will be described with reference to the drawings. In the following, the same or corresponding components are denoted by the same reference numerals throughout all the drawings, and the description thereof is omitted.

A fuel cell system according to Embodiment 1 of the present invention will be described with reference to FIG. FIG. 1 is a schematic diagram illustrating an example of the configuration of the fuel cell system according to the first embodiment. In FIG. 1, the structure when the fuel cell system which concerns on Embodiment 1 is seen from the side part is shown typically.

As shown in FIG. 1, the fuel cell system includes a raw material gas path 1, an impurity remover 3, a reformer 4, an air heat exchanger 5, a fuel cell 6, an evaporator 9, an air path 10, and a reformed water path 11. , Reformed air path 12, post-desulfurization source gas path 14, fuel gas path 16, air supply path 17, decompression section 18, recycle path 19, casing 7, first heat insulating section (heat insulating material) 22, and combustion section 23. It is the structure which comprises.

In the fuel cell system according to the first embodiment, the reformer 4, the air heat exchanger 5, the fuel cell 6, the evaporator 9, and the combustion unit 23 are arranged in the space surrounded by the casing 7. And inside the housing | casing 7, the combustion part 23 is provided in the upper part of the fuel cell 6 so that the reformer 4 may be opposed.

As shown in FIG. 1, the casing 7 includes a first casing 7 a that houses at least the fuel cell 6 and the combustion unit 23, and a second casing 7 b that surrounds the outer periphery of the first casing 7 a. It is configured. And the 1st heat insulation part (heat insulation material) 22 is provided in at least one part between these 1st housing | casing 7a and 2nd housing | casing 7b.

Note that the members accommodated in the housing 7 are not limited to these members, and it is sufficient that at least the fuel cell 6 and the combustion unit 23 are accommodated in the housing 7. That is, the reformer 4 and the air heat exchanger 5 are not necessarily provided in the housing 7. For example, in the fuel cell system according to Embodiment 1, the fuel cell 6 may be a fuel cell that generates power at a high temperature (600 ° C. or higher), such as a molten carbonate fuel cell or a solid oxide fuel cell. When these fuel cells are used, it is possible to generate power by internally reforming the raw material gas at the electrode of the fuel cell without providing the reformer 4. For this reason, the reformer 4 is not provided in the housing 7 in the case of a configuration in which power is generated by performing internal reforming. However, in view of the durability of the fuel cell, it is desirable to provide the reformer 4. For this reason, in the fuel cell system according to Embodiment 1, a configuration in which the reformer 4 is provided in the first casing 7a will be described as an example.

Further, in the fuel cell system, when the appropriately heated air is guided to the fuel cell 6, it is not necessary to provide the air heat exchanger 5. For this reason, when the air heated appropriately is guided to the fuel cell 6, the air heat exchanger 5 is not provided in the housing 7.

In this fuel cell system, a solid oxide fuel cell can be more suitably used as the fuel cell 6. For this reason, in Embodiment 1 of the present invention, a configuration using a solid oxide fuel cell as the fuel cell 6 will be described as an example.

(Composition of combustion battery system)
In the fuel cell system according to Embodiment 1, the reformer 4 reforms the raw material gas (raw fuel gas) supplied from the outside of the casing 7 (first casing 7a and second casing 7b). The fuel cell 6 is configured to generate electric power by a power generation reaction using the reformed reformed gas and air supplied from the outside. In this specification, the gas supplied from the outside through the raw material gas path 1 is referred to as a raw material gas (raw material), the sulfur component is removed from the raw material gas, and the reformer reformed by the reforming reaction in the reformer 4. The quality gas is referred to as fuel gas (fuel).

In the fuel cell system, when the fuel cell 6 operates (power generation), the combustion unit 23 burns fuel gas and air that have not been used for the power generation reaction to generate high-temperature exhaust gas, and its thermal energy. Highly efficient operation is realized by effectively using the. The generated exhaust gas flows out through the exhaust gas path 20 communicating from the inside of the first housing 7a to the outside. The exhaust gas guided from the first housing 7a to the exhaust gas path 20 is heat-utilized by the reformer 4, the air heat exchanger 5, the evaporator 9 and the like disposed in the first housing 7a. Thus, the temperature is within a predetermined temperature range. In addition, the exhaust gas is in a state in which temperature unevenness generated due to the difference in the amount of heat consumed in each member arranged in the first housing 7a is eliminated. That is, for example, even if a state in which the temperature distribution is not uniform in the casing 7 occurs, such as in the vicinity of the evaporator 9 that consumes a large amount of heat, the exhaust gas temperature is lower than in other places, the combustion unit 23 is moved upward. The exhaust gas is guided by being diffused substantially uniformly. For this reason, as a result, the temperature distribution on the upper surface side of the housing 7 is made substantially uniform.

In the fuel cell system according to the first embodiment of the present invention, the impurity remover 3 is disposed in the accommodating space provided in the exhaust gas path 20, so that the impurity remover 3 and the exhaust gas flowing through the exhaust gas path 20 are disposed. It is configured to exchange heat. That is, the exhaust gas flowing through the exhaust gas path 20 covers the entire impurity removing device 3 and passes through, so that the entire impurity removing device 3 can be heated. Further, the impurity remover 3 has, for example, a flat plate shape as shown in FIG. 1 so as to be heated as uniformly as possible by the exhaust gas introduced through the exhaust gas passage 20. The shape of the impurity remover 3 is not limited to this flat plate shape, and the impurity can be sufficiently removed from the supplied raw materials, and the exhaust gas flowing around the outer periphery of the impurity remover 3 is used as a whole. Any shape that can be uniformly heated may be used.

Further, in the fuel cell system, a first heat insulating portion (heat insulating member) 22 made of a heat insulating material is provided between the first housing 7a and the second housing 7b, and the interior of the first housing 7a. It is configured to block heat dissipation from the outside to the outside as much as possible.

Further, in the fuel cell system according to Embodiment 1 of the present invention, the booster 2 is disposed outside the first casing 7a and the second casing 7b. And the pressure | voltage rise part 2 is comprised so that the source gas supplied through the source gas path | route 1 may be pressure | voltage-rised, and it may introduce into the impurity remover 3 arrange | positioned in the housing | casing 7b. In addition, as the source gas supplied through the source gas path 1, city gas or gas mainly composed of hydrocarbons such as propane gas can be used. And in the fuel cell system which concerns on Embodiment 1 of this invention, the desulfurizer which removes a sulfur component by a hydrodesulfurization system is used as the impurity removal device 3 which removes the impurity contained in source gas.

The source gas and impurity remover 3 are not limited to those described above. For example, from the viewpoint of effective use of resources and reduction of waste, gas produced from biomass or waste can be used as a raw material gas. However, when a gas produced from biomass or waste is used as a raw material gas, it is necessary to remove impurities such as mercury or halide from the gas. Therefore, when such a gas is used as a raw material gas, the impurity remover 3 can be a heavy metal removing device filled with an impurity removing agent for removing impurities such as mercury or halides.

In the fuel cell system according to the first embodiment, as shown in FIG. 1, the impurity remover 3 is housed in a housing 27 that forms a housing space together with a part of the exhaust gas path 20. Then, the impurity remover 3 is heated using heat transfer by heat transfer of the exhaust gas as a heat source.

The fuel cell system according to Embodiment 1 further includes an air heat exchanger 5 in the first casing 7a for exchanging heat between the exhaust gas from the combustion unit 23 and the air supplied to the fuel cell 6. It has become. If such a structure is taken, it can cool with the air heat exchanger 5 so that the temperature of the waste gas from the combustion part 23 may become a predetermined range. Therefore, it becomes easier to maintain the impurity remover 3 at an appropriate temperature without separately providing a temperature adjusting unit for adjusting the temperature of the impurity remover 3. In addition, since the air heat exchanger 5 uses the amount of heat recovered by heat exchange with the exhaust gas for heating the air supplied to the fuel cell 6, an efficient operation is possible.

When the impurity remover 3 functions as a desulfurizer, examples of the desulfurizer filled in the impurity remover 3 include a desulfurizer containing copper and zinc (for example, Patent Document 6). The desulfurizing agent is not limited to this desulfurizing agent as long as hydrodesulfurization can be performed, and may be a combination of a Ni—Mo based or Co—Mo based catalyst and zinc oxide. In the case of a desulfurization agent in which a Ni—Mo or Co—Mo catalyst and zinc oxide are combined, the impurity remover 3 hydrocrackes organic sulfur in the raw material gas in a temperature range of 350 to 400 ° C. Then, the impurity remover 3 removes the generated H ₂ S by adsorbing it to ZnO in a temperature range of 350 to 400 ° C.

For example, when the source gas is city gas, dimethyl sulfide (C ₂ H ₆ S, DMS), which is a sulfur compound, is contained as an odorant. This DMS is removed by the desulfurization agent in the impurity remover 3 in the form of ZnS according to the following reaction formulas (formulas (1) and (2)) or in the form of physical adsorption.
C ₂ H ₆ S + 2H ₂ → 2CH ₄ + H ₂ S (1)
H ₂ S + ZnO → H ₂ O + ZnS (2)
The odorant is not limited to the above-described DMS, and may be another sulfur compound such as TBM (C ₄ H ₁₀ S) or THT (C ₄ H ₈ S).

When the desulfurizing agent to be filled contains copper and zinc, the impurity remover 3 performs desulfurization in a temperature range of about 10 to 400 ° C., preferably about 150 to 300 ° C. This copper zinc-based desulfurization agent has a physical adsorption capability in addition to a hydrodesulfurization capability, and can mainly perform physical adsorption at low temperatures and chemical adsorption (H ₂ S + ZnO → H ₂ O + ZnS) at high temperatures. In this case, the sulfur content contained in the raw material gas after desulfurization is 1 vol ppb (parts per billion) or less, usually 0.1 vol ppb or less.

Thus, when the impurity remover 3 is filled with a Ni—Mo-based or Co—Mo-based catalyst, or a desulfurizing agent containing either copper and zinc, the amount of sulfur component removed per unit volume increases. . Therefore, when the above-described desulfurizing agent is used, the amount of the desulfurizing agent necessary for removing sulfur to a desired sulfur concentration can be reduced.

The raw material gas desulfurized by the impurity remover 3 as described above is supplied to the reformer 4 (evaporator 9) through the raw material gas path 14 after desulfurization.

Next, the reformer 4 will be described. The reformer 4 may be used for partial oxidation reforming. However, in order to realize more efficient operation, the reformer 4 is designed to perform not only partial oxidation reforming reaction but also steam reforming reaction. It is advantageous to keep it. As shown in FIG. 1, in the first embodiment, an evaporator 9 is arranged on the upstream side of the reformer 4 (the side where the raw material gas path 14 after desulfurization is arranged), and the reforming water path 11 is externally provided by the evaporator 9. Water (reformed water) supplied through is evaporated to generate water vapor. The steam generated by the evaporator 9 and the desulfurized source gas are mixed and supplied to the reformer 4.

As the reforming catalyst filled in the reformer 4, the Al ₂ O ₃ (alumina) sphere surface is impregnated with Ni and supported, or the Al ₂ O ₃ sphere surface is provided with ruthenium. Can be used as appropriate.

By the way, when the fuel cell system is started, heat energy is insufficient to perform the steam reforming reaction which is an endothermic reaction in the reformer 4. Therefore, when the fuel cell system is started, the reformer 4 uses the air introduced into the reformer 4 through the reformed air path 12 without supplying water from the reformed water path 11 to the evaporator 9. A partial oxidation reforming reaction represented by the following formula (3) is performed to generate hydrogen gas and carbon monoxide as a hydrogen-containing gas.

_{_{C n H m + (n /}} 2) O 2 → n · CO + (m / 2) H 2 (n, m is an arbitrary natural number) (3)
Then, these hydrogen gas and carbon monoxide are supplied to the fuel cell 6 through the fuel gas supply path 16, and together with the air supplied through the air supply path 17, a power generation reaction is performed.

As the fuel cell system starts and power generation proceeds, the temperature of the reformer 4 increases. That is, the partial oxidation reforming reaction represented by the above formula (3) is an exothermic reaction, and furthermore, the heat of the exhaust gas generated in the combustion unit 23 and the radiant heat from the combustion heat 23 (due to the combustion of the combustion unit 23) The temperature of the reformer 4 is raised by the combustion heat. And if the temperature of the reformer 4 becomes 400 degreeC or more, for example, it will become possible to perform the steam reforming reaction represented by the following formula | equation (4) in parallel.

_{_{_{C n H m + n · H}}} 2 O → n · CO + (m / 2 + n) H 2 (n, m is an arbitrary natural number) (4)
Compared with the partial oxidation reforming reaction represented by the formula (3), the steam reforming reaction represented by the formula (4) described above has a larger amount of hydrogen that can be generated from the same amount of hydrocarbon (C _n H _m ). As a result, the amount of reformed gas available for the power generation reaction in the fuel cell 6 increases. That is, the reforming gas can be generated more efficiently by the steam reforming reaction.

Further, since the steam reforming reaction shown in the formula (4) is an endothermic reaction, the heat generated by the partial oxidation reforming reaction shown in the formula (3), the heat held in the exhaust gas discharged from the combustion unit 23, and the combustion unit 23 The steam reforming reaction is allowed to proceed while supplementing the necessary amount of heat using the radiant heat from. And, if the temperature of the reformer 4 becomes 600 ° C. or more, for example, the amount of heat necessary for the steam reforming reaction of the formula (4) can be supplemented only with the heat of the exhaust gas and the radiant heat from the combustion section 23. Therefore, it is possible to switch to the operation of only the steam reforming reaction.

The evaporator 9 is installed to perform a steam reforming reaction in the reformer 4. In the evaporator 9, the water (reformed water) supplied from the reformed water path 11 is vaporized using the heat of the exhaust gas discharged from the combustor 23 and the radiant heat from the combustor 23, and the impurity remover 3. And mixed with the raw material gas after desulfurization supplied from. Then, the evaporator 9 introduces the mixed raw material gas into the reformer 4.

As described above, the fuel cell 6 generates power by a power generation reaction using the fuel (reformed gas) supplied through the fuel gas path 16 and the air (power generation air) supplied through the air supply path 17. Is. That is, the solid oxide fuel cell used for the fuel cell 6 has a fuel electrode to which fuel (reformed gas) is supplied and an air electrode to which power generation air is supplied, and is provided between the fuel electrode and the air electrode. A cell stack is formed by connecting a plurality of fuel cell single cells that generate power by performing a power generation reaction in series. In addition, the fuel cell 6 is good also as a structure which connected the cell stack further connected in series in parallel.

The fuel cell unit cell constituting the solid oxide fuel cell used for the fuel cell 6 includes, for example, a zirconia doped with yttria (YSZ), a zirconia doped with yttrium or scandium, or a lanthanum gallate solid electrolyte. A single cell can be used. For example, when the single fuel cell is YSZ, the power generation reaction is performed in a temperature range of about 600 to 900 ° C., depending on the thickness.

Further, in the fuel cell system according to Embodiment 1, the fuel gas supply path 16 toward the fuel cell 6 is branched in the middle, and a part of the reformed gas supplied from the reformer 4 is used as a hydrogen-containing gas as a raw material gas. A recycling path 19 for returning to the path 1 is provided. For this reason, it becomes possible to add hydrogen to the raw material gas that flows through the raw material gas path 1 and is supplied to the impurity remover 3, and the impurity remover 3 uses the hydrogen to perform the hydrodesulfurization described above. It is configured to be able to do.

A decompression unit 18 is provided in the vicinity of the branch point between the fuel gas supply path 16 and the recycle path 19 and in the recycle path 19. The decompression unit 18 adjusts the flow rate of the reformed gas flowing through the recycle path 19 and can be realized by, for example, a capillary tube. That is, the decompression unit 18 is configured so that the reformed gas flows through the recycle path 19 by a desired flow rate by narrowing the flow path with a capillary tube or the like and increasing the pressure loss.

In the first embodiment of the present invention, the impurity remover 3 is housed in the container 27. As shown in FIG. 1, the container 27 extends in the left-right direction in FIG. 1 on the upper surface of the housing 7 and has a structure in which the inside is hollow. And the protrusion part which protruded below in the perpendicular direction is formed so that it may connect with the exhaust gas path | route 20 in one edge part (left edge part in FIG. 1). The other end (the right end in FIG. 1) is formed with a protruding portion that protrudes upward in the vertical direction so that the exhaust gas flowing through the container 27 is discharged outside the system. . In this way, the container 27 and the exhaust gas path 20 communicate with each other. In other words, at least a part of the exhaust gas path 20 is formed in the container 27.

Furthermore, a second heat insulating part (heat insulating material) 33 is provided inside the container 27. Thereby, the heat radiation from the inside of the container 27 to the outside can be blocked as much as possible. Further, the housing 7 and the container 27 are connected by a raw material gas path connection part (second connection part) 32 and an exhaust gas path connection part 31. And the 2nd connection part 32 and the waste gas path | route connection part 31 are comprised so that the source gas or waste gas which distribute | circulates the inside of a path | route may not leak outside. Specifically, as a member constituting the exhaust gas path connection portion 31 and the second connection portion 32, for example, a joint represented by Swagelok (registered trademark) can be suitably used.

As shown in FIG. 2, the fuel cell system according to Embodiment 1 has a configuration in which the container 27 can be detached from the housing 7 via the exhaust gas path connection portion 31 and the second connection portion 32. FIG. 2 is a schematic diagram showing a configuration when the casing 7 and the container 27 are separated from each other in the configuration of the fuel cell system according to the first embodiment.

In this way, by adopting a configuration in which the storage device 27 can be detached from the housing 7, the storage device 27 containing the impurity remover 3 can be easily attached to the housing 7 when the fuel cell system is manufactured. Is possible. Further, even after a long time has passed since the fuel cell system was operated, even if the catalyst charged in the impurity remover 3 is deteriorated and the impurity remover 3 needs to be replaced, the container 7 can be replaced with the container. It is easy to remove 27 and remove the impurity remover 3 accommodated in the container 27. Therefore, a fuel cell system excellent in maintainability can be configured.

In addition, as described above, when the impurity remover 3 is filled with a desulfurization agent in which a Ni—Mo or Co—Mo catalyst and zinc oxide are combined, the temperature range of 350 to 400 ° C. or the desulfurization agent is copper. When zinc is contained, the temperature is set to about 10 to 400 ° C., preferably about 150 to 300 ° C. Therefore, for example, as shown in FIG. 16 to be described later, a raw material gas path connection portion (first connection portion) 30 for connecting the impurity remover 3 in the storage device 27 and the raw material gas path 14 after desulfurization, and the storage device. The exhaust gas path connection portion 31 that connects the exhaust gas path 27 and the exhaust gas path 20 also has the same temperature range as the impurity remover 3. And these connection parts are also configured to be accommodated in the first heat insulating part (heat insulating material part) 22 or in the second heat insulating part (heat insulating material part) 33, so that radiation from the combustion part 23 and exhaust gas from Due to heat transfer such as heat transfer, it is possible to suppress the occurrence of problems such as exposure to high temperatures (400 ° C. or higher) for a long time and thermal degradation.

(Modification of Embodiment 1)
Next, the configuration of a fuel cell system according to a modification of the first embodiment of the present invention will be described with reference to FIG. FIG. 3 is a schematic diagram showing an example of the configuration of a fuel cell system according to a modification of Embodiment 1 of the present invention. In FIG. 3, the structure when the fuel cell system which concerns on the modification of Embodiment 1 is seen from the side part is shown typically.

The fuel cell system according to the modification of the first embodiment is different from the first embodiment in the position where the container 27 is disposed. Specifically, in the fuel cell system according to Embodiment 1, the container 27 is disposed on the upper surface of the second casing 7b. On the other hand, in the fuel cell system according to the modification of the first embodiment, as shown in FIG. 3, the container 27 is disposed so as to be accommodated between the first casing 7a and the second casing 7b. ing. That is, the surface exposed to the outside of the container 27 is disposed so as to be substantially at the same height as the upper surface of the second housing 7b. The fuel cell system according to the modification of the first embodiment has the same configuration as the fuel cell system according to the first embodiment except for the arrangement of the container 27. For this reason, the same code | symbol is attached | subjected to the same member and description of each member is abbreviate | omitted, respectively.

In the fuel cell system according to the modification of the first embodiment, the container 27 is disposed at the above-described position. Therefore, the container 27 is further provided from the upper surface of the second housing 7b as in the fuel cell system according to the first embodiment. However, the size of the entire fuel cell system can be reduced. Moreover, if the thickness of the 1st heat insulation part 22 and the 2nd heat insulation part 33 between the 1st housing | casing 7a and the container 27 is taken sufficiently, by heat transfer, such as radiant heat from the 1st housing | casing 7a, The impurity remover 3 is prevented from being heated, and the temperature of the impurity remover 3 can be controlled by the exhaust gas flowing through the exhaust gas path 20.

In addition, the fuel cell system according to the modification of the first embodiment includes the second connection portion 32 and the exhaust gas path connection portion 31 as in the fuel cell system according to the first embodiment. Therefore, as shown in FIG. 27 can be attached to and detached from the housing 7 (second housing 7b). FIG. 4 is a schematic diagram showing a configuration when the first casing 7a and the container 27 are separated in the configuration of the fuel cell system according to the modification of the first embodiment. Since the container 27 is configured to be detachable from the second housing 7b as described above, the impurity remover 3 can be easily detached or attached in the fuel cell system. Therefore, manufacture and maintenance of the fuel cell system are facilitated.

In the above description, the impurity remover 3 is housed in the container 27 and heated to be maintained at a predetermined temperature by the exhaust gas flowing through the exhaust gas path 20. However, the impurity remover 3 is not limited to the configuration housed in the container 27 as described above, and is inside the housing 7, that is, between the first housing 7a and the second housing 7b. The structure which the impurity removal device 3 is provided in the heat insulation part provided in the middle may be sufficient. Hereinafter, the case of such a configuration will be described as a second embodiment.

(Embodiment 2)
A fuel cell system according to Embodiment 2 will be described with reference to FIGS. 5 and 6. 5 and 6 are schematic diagrams illustrating an example of the configuration of the fuel cell system according to Embodiment 2. FIG. In FIG. 5, the structure when the fuel cell system which concerns on Embodiment 2 is seen from the side part is shown typically. In FIG. 6, the structure when the inside of the housing | casing 7 of the fuel cell system which concerns on Embodiment 2 is seen from the top is shown typically. The housing 7 is composed of a first housing 7a and a second housing 7b as in the first embodiment, but is not particularly shown here.

As shown in FIGS. 5 and 6, the fuel cell system according to the second embodiment is similar to the fuel cell system according to the first embodiment described above, with the impurity remover 3, the reformer 4, the air heat exchanger 5, The fuel cell 6, the evaporator 9, and the decompression unit 18 are arranged inside the housing 7. A combustion unit 23 is provided on the upper portion of the fuel cell 6 so as to face the reformer 4.

Further, in the fuel cell system according to the second embodiment, the raw material gas (raw fuel gas) supplied from the outside of the housing 7 is reformed by the reformer 4 as in the fuel cell system according to the first embodiment described above. The fuel cell 6 is configured to generate power by a power generation reaction using the reformed reformed gas and air supplied from the outside.

That is, the fuel cell system according to Embodiment 2 is different from the fuel cell system according to Embodiment 1 in that the impurity remover 3 is housed in the first heat insulating portion 22 instead of the housing 27. . Since it becomes the same structure except it, the same code | symbol is attached | subjected to the same member and the description is abbreviate | omitted.

Also in the fuel cell system according to Embodiment 2, the impurity remover 3 can be a desulfurizer that removes sulfur components contained in the raw material gas by, for example, a hydrodesulfurization method. In the second embodiment, the impurity remover 3 is disposed below the side surface on the right side of the casing 7 in FIG.

Further, in the fuel cell system according to Embodiment 2, the decompression unit 18 is provided in the housing 7, but the position where the decompression unit 18 is provided is not limited to this position. For example, the above-described Embodiment 1, Alternatively, as shown in the fuel cell system according to Embodiment 3 described later, a decompression unit 18 may be provided outside the housing 7.

Next, a process in which the exhaust gas generated in the combustion unit 23, which is a characteristic configuration of the fuel cell system according to Embodiment 2, circulates in the exhaust gas path 20, and an impurity remover 3 provided in a part of the exhaust gas path 20, Will be described. In addition, the exhaust gas path 20 is formed in the 1st heat insulation part 22, and it is comprised so that the heat radiation from this exhaust gas path 20 can be reduced as much as possible.

By the way, about the flow volume and temperature of the exhaust gas produced | generated in the combustion part 23, the fuel utilization rate (ratio consumed by the fuel cell 6 as a fuel by power generation reaction) of the fuel gas and air (power generation air) in the fuel cell 6 is shown. It is possible to control by adjusting. In the second embodiment, for example, the fuel utilization rate of the fuel gas and air in the fuel cell 6 is set so that the temperature range of the combustion unit 23 is about 600 to 900 ° C.

In the second embodiment, the reformer 4 is first heated by the exhaust gas generated by burning unused fuel gas and air in the combustion unit 23. Thereby, a part of the heat of the exhaust gas is consumed. Further, the air heat exchanger 5 is heated by the exhaust gas in which a part of the heat is consumed. Due to the heat exchange between the air and the exhaust gas by the air heat exchanger 5, the heat of the exhaust gas is further deprived and the temperature is lowered to an appropriate temperature for heating the impurity remover 3. The exhaust gas whose temperature has been lowered in this way flows through the exhaust gas path 20 and is supplied to the impurity remover 3.

That is, the temperature of the exhaust gas generated in the combustion section 23 is as high as about 600 ° C. to 900 ° C., for example. However, if the reformer 4 is heated by this exhaust gas, and heat exchange with air is further performed by the air heat exchanger 5, and the air is heated, the temperature of the exhaust gas decreases until reaching the exhaust gas path 20. In particular, when generating 1 kW, for example, using a fuel cell, it is necessary to heat air of 50 L / min or more from the outside temperature to about 400 to 800 ° C. Therefore, the air heat exchanger 5 has a large amount of heat. Is required. Therefore, this necessary amount of heat is covered by the amount of heat of the exhaust gas.

As described above, the temperature of the exhaust gas flowing through the exhaust gas path 20 includes the flow rate and temperature of the exhaust gas generated in the combustion unit 23, the amount of heat absorbed by the reformer 4, the amount of heat absorbed by the air heat exchanger 5, and the like. Is controlled to take a desired value. Then, the exhaust gas that has reached the exhaust gas path 20 circulates in the path and flows to the impurity remover 3. And exhaust gas is discharged | emitted out of a flow system, surrounding the outer periphery of the impurity removal part 3. FIG.

Next, the exhaust gas temperature when reaching the impurity remover 3 will be described.

When the impurity remover 3 is filled with a desulfurization agent containing copper and zinc (for example, Patent Document 6), the combustion section 23 is set so that the exhaust gas temperature when reaching the impurity remover 3 is about 150 to 350 ° C. The flow rate and temperature of the exhaust gas generated in step 1, the amount of heat absorbed by the reformer 4, the amount of heat absorbed by the air heat exchanger 5, and the like are adjusted. In this way, the impurity remover 3 is set to a temperature (150 to 300 ° C.) suitable for hydrodesulfurization.

In addition, when the impurity remover 3 is filled with a desulfurization agent that is a combination of a Ni—Mo or Co—Mo catalyst and zinc oxide, the exhaust gas temperature when reaching the impurity remover 3 is about 350 to 450 ° C. Thus, the flow rate and temperature of the exhaust gas generated in the combustion unit 23, the amount of heat absorbed by the reformer 4, and the amount of heat absorbed by the air heat exchanger 5 are adjusted. In this way, the impurity remover 3 is similarly set to a temperature (350 to 400 ° C.) suitable for hydrodesulfurization.

As described above, by installing the impurity remover 3 in the exhaust gas path 20, the impurity remover 3 can be set to a desired temperature suitable for hydrodesulfurization.

Further, the impurity remover 3 is installed so as to be covered with the first heat insulating portion 22. By doing so, it is possible to prevent heat from being removed from the impurity remover 3 and to prevent the impurity remover 3 from being directly exposed to the heat of 500 to 600 ° C. in the housing 7. Furthermore, since the impurity remover 3 is covered by the first heat insulating portion 22, the temperature distribution in the impurity remover 3 can be made as uniform as possible to suppress variations. Therefore, temperature control in the impurity remover 3 can be facilitated.

In addition, when the reforming catalyst charged in the impurity remover 3 deteriorates after a long operation, there is a concern that the performance of the entire fuel cell system is remarkably lowered. Therefore, the impurity remover 3 is detachable from the housing 7. For this reason, it is possible to operate for a longer time by simply replacing the impurity remover 3 with the deteriorated reforming catalyst with a new impurity remover 3.

(Modification 1 of Embodiment 2)
Next, Modification 1 of the fuel cell system according to Embodiment 2 will be described with reference to FIG. FIG. 7 is a schematic diagram showing an example of the configuration of a fuel cell system according to Modification 1 of Embodiment 2. In FIG. 7, the structure when the fuel cell system which concerns on the modification 1 of Embodiment 2 is seen from the side part is shown typically. In addition, since the structure when the inside of the housing 7 of the fuel cell system according to Modification 1 of Embodiment 2 is viewed from above is similar to the structure of the fuel cell system shown in FIG. 6, it is not shown.

The fuel cell system according to Modification 1 of Embodiment 2 is different from the fuel cell system according to Embodiment 2 described above in that an exhaust gas heat exchanger 21 is further provided on the outer periphery of the impurity remover 3. For this reason, the same code | symbol is attached | subjected to the member similar to the fuel cell system which concerns on Embodiment 2, and the description shall be abbreviate | omitted.

The exhaust gas heat exchanger 21 heats the impurity remover 3 to a desired temperature by exchanging heat between the exhaust gas flowing in the exhaust gas path 20 and the impurity remover 3. In order to reduce the heat radiation from the exhaust gas path 20 as much as possible, it is beneficial that the exhaust gas heat exchanger 21 is also formed in the first heat insulating portion 22. Since the fuel cell system according to the first modification of the second embodiment includes the exhaust gas heat exchanger 21 as described above, the heat transfer area between the impurity remover 3 and the exhaust gas flowing through the exhaust gas path 20 is increased and the heat is increased. The transmission rate can be improved. Therefore, it is possible to quickly heat the impurity remover 3 so that the temperature is suitable for hydrodesulfurization.

(Modification 2 of Embodiment 2)
Furthermore, Modification 2 of the fuel cell system according to Embodiment 2 will be described with reference to FIG. FIG. 8 is a schematic diagram illustrating an example of a configuration of a fuel cell system according to Modification 2 of Embodiment 2. In FIG. 8, the structure when the fuel cell system which concerns on the modification 2 of Embodiment 2 is seen from the side part is shown typically. In addition, since the structure when the inside of the housing | casing 7 of the fuel cell system which concerns on the modification 2 of Embodiment 2 is seen from the top becomes the same as that of the structure of the fuel cell system shown in FIG. 6, it is not illustrated.

The fuel cell system according to Modification 2 of Embodiment 2 is different from the fuel cell system according to Embodiment 2 described above in that it further includes an exhaust gas heat exchanger 21 and a condenser 24. That is, the fuel cell system according to Modification 2 of Embodiment 2 is a configuration further including a condenser 24 in the configuration of the fuel cell system according to Modification 1 of Embodiment 2. For this reason, the same code | symbol is attached | subjected to the member similar to the fuel cell system which concerns on Embodiment 2, or the fuel cell system which concerns on the modification 1 of Embodiment 2, and the description shall be abbreviate | omitted.

The condenser 24 is provided in the recycle path 19 and condenses water contained in the fuel gas flowing through the recycle path 19. The water obtained by condensation is stored in a drain tank (not shown).

As described above, the fuel cell system according to Modification 2 of Embodiment 2 includes the condenser 24. Therefore, when the circulating fuel gas is cooled in the recycling path 19, the condenser 24 collects moisture. Can do. For this reason, it is possible to suppress problems such as water in the flow path (recycle path 19) due to condensed water, that is, corrosion and breakage of the pressure increasing unit 2.

(Modification 3 of Embodiment 2)
Next, Modification 3 of the fuel cell system according to Embodiment 2 will be described with reference to FIG. FIG. 9 is a schematic diagram illustrating an example of a configuration of a fuel cell system according to Modification 3 of Embodiment 2. In FIG. 9, the structure when the fuel cell system which concerns on the modification 3 of Embodiment 2 is seen from the side part is shown typically. In addition, since the structure when the inside of the housing | casing 7 of the fuel cell system which concerns on the modification 3 of Embodiment 2 is seen from the top becomes the same as the structure shown in FIG. 6, it is not illustrated.

The fuel cell system according to Modification 3 of Embodiment 2 differs from the fuel cell system according to Embodiment 2 described above in that it further includes an exhaust gas heat exchanger 21, a condenser 24, and a fan 25. . That is, the fuel cell system according to Modification 3 of Embodiment 2 has a configuration in which the fan 25 is further provided outside the housing 7 in the configuration of the fuel cell system according to Modification 2 of Embodiment 2. For this reason, the same code | symbol is attached | subjected to the member similar to the fuel cell system which concerns on Embodiment 2, or the fuel cell system which concerns on the

modifications

1 and 2, and the description shall be abbreviate | omitted.

The fan 25 is a blower for sending air to cool the impurity remover 3. Since the fuel cell system according to Modification 3 of Embodiment 2 includes the fan 25, when the temperature of the impurity remover 3 rises excessively, it is easily cooled to a desired temperature by forced convection from the fan 25. be able to.

In addition, it is advantageous that the surface on the side where the impurity remover 3 is cooled by the fan 25 is not covered with the first heat insulating portion 22 in order to increase the cooling efficiency.

(Modification 4 of Embodiment 2)
Next, a fuel cell system according to Modification 4 of Embodiment 2 will be described with reference to FIGS. 10 and 11 are schematic views showing an example of the configuration of a fuel cell system according to Modification 4 of Embodiment 2. In FIG. 10, the structure when the fuel cell system which concerns on the modification 4 of Embodiment 2 is seen from the side part is shown typically. In FIG. 11, the structure when the inside of the housing | casing 7 of the fuel cell system which concerns on the modification 4 of Embodiment 2 is seen from the top is shown typically.

The fuel cell system according to Modification 4 of Embodiment 2 differs from the fuel cell system according to Embodiment 2 shown in FIGS. That is, in the fuel cell system according to the second embodiment, the impurity remover 3 is disposed below the right side surface of the casing 7, whereas the fuel cell system according to the fourth modification of the second embodiment It differs in that it is arranged at a substantially central part (position facing the combustion part 23) on the upper surface side of the body 7. For this reason, the same code | symbol is attached | subjected to the member similar to the fuel cell system which concerns on Embodiment 2, and the description shall be abbreviate | omitted.

In the fuel cell system according to Modification 4 of Embodiment 2, the impurity remover 3 is disposed on the upper surface side of the housing 7 and at a position facing the combustion unit 23. The exhaust gas holding the heat generated by the fuel cell 6 and the combustion heat generated by the combustion of the combustion section 23 rises toward the upper surface of the casing 7, first heating the reformer 4, and then the air heat exchanger In the state where a part of the heat held by heat exchange with the heat exchanger 5 is taken away, it goes to the impurity remover 3 above the combustion section 23. That is, the exhaust gas goes to the impurity remover 3 in a state where the exhaust gas is lowered to a temperature suitable for the desulfurizing agent charged in the impurity remover 3.

Here, since the exhaust gas is diffused and guided substantially uniformly above the combustion section 23, the temperature distribution on the upper surface side of the housing 7 is made substantially uniform. Therefore, the temperature distribution of the impurity remover 3 can be made uniform, and the hydrodesulfurization can be efficiently performed on the impurity remover 3. And the exhaust gas which heated the impurity removal device 3 uniformly in this way distribute | circulates the exhaust gas path | route 20, and is discharged | emitted outside the housing | casing 7. FIG.

The upper surface of the housing 7 is detachable, and the impurity remover 3 is detachable from the upper surface. For this reason, when replacing the impurity remover 3, first, the upper surface of the housing 7 is removed, and then the impurity remover 3 is removed from the upper surface of the housing 7.

(Modification 5 of Embodiment 2)
Next, a fuel cell system according to Modification 5 of Embodiment 2 will be described with reference to FIG. FIG. 12 is a schematic diagram illustrating an example of a configuration of a fuel cell system according to Modification 5 of Embodiment 2. In FIG. 12, the structure when the fuel cell system which concerns on the modification 5 of Embodiment 2 is seen from the side part is shown typically. In addition, since the structure when the inside of the housing | casing 7 of the fuel cell system which concerns on the modification 5 of Embodiment 2 is seen from the top becomes the same as the structure of the modification 4 shown in FIG. 11, it is not illustrated.

The fuel cell system according to Modification 5 of Embodiment 2 differs from the fuel cell system according to Embodiment 2 shown in FIGS. That is, in the fuel cell system according to the second embodiment, the impurity remover 3 is disposed below the right side surface of the housing 7, whereas the fuel cell system according to the fifth modification of the second embodiment It differs in that it is arranged at a substantially central part (position facing the combustion part 23) on the upper surface side of the body 7. Another difference is that a condenser 24 is further provided in the recycling path 19. That is, it can be said that the fuel cell system according to Modification 5 of Embodiment 2 has a configuration in which the condenser 24 is further provided in the recycling path 19 in the configuration of Modification 4 of Embodiment 2 described above. For this reason, the same code | symbol is attached | subjected to the member similar to the fuel cell system which concerns on Embodiment 2, and the description shall be abbreviate | omitted.

In the fuel cell according to Modification 5 of Embodiment 2, the impurity remover 3 is disposed on the upper surface side of the housing 7 and at a position facing the combustion unit 23. For this reason, the impurity remover 3 is heated substantially uniformly by the exhaust gas generated by the combustion unit 23. A condenser 24 is provided in the recycle path 19. As described above, the fuel cell system according to Modification 5 of Embodiment 2 includes the condenser 24, and therefore, when the circulating fuel gas is cooled in the recycling path 19, water is collected by the condenser 24. Can do. For this reason, it is possible to suppress problems such as water in the flow path (recycle path 19) due to condensed water, that is, corrosion and breakage of the pressure increasing unit 2.

(Modification 6 of Embodiment 2)
Next, a fuel cell system according to Modification 6 of Embodiment 2 will be described with reference to FIGS. 13 and 14 are schematic views showing an example of the configuration of a fuel cell system according to Modification 6 of Embodiment 2. In FIG. 13, the structure when the fuel cell system which concerns on the modification 6 of Embodiment 2 is seen from the side part is shown typically. In FIG. 14, the structure when the inside of the housing | casing 7 of the fuel cell system which concerns on the modification 6 of Embodiment 2 is seen from the top is shown typically.

The fuel cell system according to Modification 6 of Embodiment 2 differs from the fuel cell system according to Embodiment 2 shown in FIGS. That is, in the fuel cell system according to the second embodiment, the impurity remover 3 is disposed below the right side surface of the housing 7, whereas the fuel cell system according to the sixth modification of the second embodiment It is different in that it is arranged at a substantially central portion on the upper surface side of the body 7. Further, the exhaust gas path 20 is different in that it includes an exhaust gas heat exchanger 21 that performs heat exchange between the impurity remover 3 and the exhaust gas flowing through the exhaust gas path 20. That is, it can be said that the fuel cell system according to Modification 6 of Embodiment 2 has a configuration in which the exhaust gas heat exchanger 21 is further provided in the exhaust gas path 20 in the configuration of Modification 4 of Embodiment 2 described above. For this reason, the same code | symbol is attached | subjected to the member similar to the fuel cell system which concerns on Embodiment 2, and the description shall be abbreviate | omitted.

In the fuel cell according to Modification 6 of Embodiment 2, the impurity remover 3 is disposed on the upper surface side of the casing 7 and at a position facing the combustion unit 23. For this reason, the impurity remover 3 is heated substantially uniformly by the exhaust gas generated by the combustion unit 23. In particular, since the fuel cell according to Modification 6 of Embodiment 2 includes the exhaust gas heat exchanger 21 in the exhaust gas path 20, the heat transfer area between the impurity remover 3 and the exhaust gas flowing through the exhaust gas path 20. Can be expanded and the heat transfer rate can be improved. Therefore, it is possible to raise the temperature to a temperature suitable for performing hydrodesulfurization quickly while keeping the temperature distribution of the impurity remover 3 uniform.

(Modification 7 of Embodiment 2)
Next, a fuel cell system according to Modification 7 of Embodiment 2 will be described with reference to FIG. FIG. 15 is a schematic diagram illustrating an example of a configuration of a fuel cell system according to Modification 7 of Embodiment 2. FIG. 15 schematically shows a configuration when the fuel cell system according to Modification 7 of Embodiment 2 is viewed from the side. In addition, since the structure when the inside of the housing | casing 7 of the fuel cell system which concerns on the modification 7 of Embodiment 2 is seen from the top becomes the same as the structure of the modification 6 shown in FIG. 14, it is not illustrated.

The fuel cell system according to Modification 7 of Embodiment 2 differs from the fuel cell system according to Embodiment 2 shown in FIGS. That is, in the fuel cell system according to the second embodiment, the impurity remover 3 is disposed below the right side surface of the casing 7, whereas the fuel cell system according to the seventh modification of the second embodiment It differs in that it is arranged at a substantially central part (position facing the combustion part 23) on the upper surface side of the body 7. Further, the exhaust gas path 20 is different in that it includes an exhaust gas heat exchanger 21 that performs heat exchange between the impurity remover 3 and the exhaust gas that flows through the exhaust gas path 20, and also includes a condenser 24 in the recycle path 19. That is, it can be said that the fuel cell system according to Modification 7 of Embodiment 2 has a configuration in which the condenser 24 is further provided in the recycling path 19 in the configuration of Modification 6 of Embodiment 2 described above. For this reason, the same code | symbol is attached | subjected to the member similar to the fuel cell system which concerns on Embodiment 2, and the description shall be abbreviate | omitted.

In the fuel cell according to Modification Example 7 of Embodiment 2, the impurity remover 3 is disposed on the upper surface side of the housing 7 and at a position facing the combustion unit 23. For this reason, the impurity remover 3 is heated substantially uniformly by the exhaust gas generated by the combustion unit 23. In particular, since the fuel cell according to Modification 7 of Embodiment 2 includes the exhaust gas heat exchanger 21 in the exhaust gas path 20, the heat transfer area between the impurity remover 3 and the exhaust gas flowing through the exhaust gas path 20. Can be expanded and the heat transfer rate can be improved. Therefore, it is possible to raise the temperature to a temperature suitable for performing hydrodesulfurization quickly while keeping the temperature distribution of the impurity remover 3 uniform.

Also, a condenser 24 is provided in the recycling path 19. Thus, since the fuel cell system according to Modification 7 of Embodiment 2 includes the condenser 24, when the circulating fuel gas is cooled in the recycle path 19, water is collected by the condenser 24. Can do. For this reason, it is possible to suppress problems such as water in the flow path (recycle path 19) due to condensed water, that is, corrosion and breakage of the pressure increasing unit 2.

As described above, the fuel cell system according to Embodiment 2 can provide a fuel cell system that operates stably with high efficiency.

That is, the fuel cell system according to Embodiment 2 uses a fuel cell 6 (for example, a solid oxide fuel cell) that generates electricity by a power generation reaction using supplied fuel and air, and is unused in the fuel cell 6. A reforming gas to be the fuel is generated from the supplied raw material by a reforming reaction using the combustion part 23 that burns fuel and air, and the heat of the exhaust gas that holds the combustion heat generated by the combustion of the combustion part 23 The reformer 4, the evaporator 9 that evaporates the water supplied by using the heat of the exhaust gas and generates water vapor, and the heat of the exhaust gas after being used by the reformer 4 The air heat exchanger 5 that heats the air supplied to the battery 6 and the heat of the exhaust gas after being heat-utilized by the air heat exchanger 5 are used to hydrodesulfurize the sulfur component contained in the supplied raw material. Removing impurities and supplying them to the reformer 4 Vessel 3 (e.g., desulfurizer) is provided with a, a.

Thus, since the fuel cell system according to Embodiment 2 includes the impurity remover 3, the fuel cell system can be supplied to the reformer 4 with the sulfur component removed from the raw material. For this reason, since the deterioration of the reforming catalyst of the reformer 4 due to the sulfur component can be prevented, the reformer 4 can be used for a long term. Therefore, in the fuel cell system, the long-term durability of the system can be ensured.

The impurity remover 3 is configured to perform hydrodesulfurization using the heat of the exhaust gas that has been used by the reformer 4 and the air heat exchanger 5 and has been lowered to a predetermined temperature. That is, the impurity remover 3 can be heated with exhaust gas so as to have a desired temperature suitable for hydrodesulfurization.

Therefore, the fuel cell system according to Embodiment 2 can control the temperature of the impurity remover 3 so as to be a temperature suitable for hydrodesulfurization and ensure long-term durability. Furthermore, the fuel cell system according to Embodiment 2 is a configuration in which the impurity remover 3 may be disposed above the combustion unit 23 and at a position facing the fuel cell system in the configuration described above.

Here, the exhaust gas that retains the heat generated by the fuel cell 6 and the combustion heat generated by the combustion of the combustion section 23 heats the position above and facing the combustion section 23 with a substantially uniform temperature distribution. According to the above-described configuration, the impurity remover 3 is disposed above and corresponding to the combustion unit 23, so that the impurity remover 3 can be heated uniformly. For this reason, the impurity remover 3 can efficiently desulfurize the raw material gas. Furthermore, the impurity remover 3 is arranged in a housing space (housing device 27) provided so as to constitute a part of the exhaust gas route 20 in the middle of the exhaust gas route 20, and circulates around the outer periphery of the impurity remover 3. It is the structure heated by the waste gas which does. For this reason, the entire impurity remover 3 can be heated substantially uniformly by the exhaust gas.

In addition, the fuel cell system according to Embodiment 2 may further include an exhaust gas heat exchanger 21 that performs heat exchange between the impurity remover 3 and the exhaust gas in the configuration described above.

According to this configuration, since the exhaust gas heat exchanger 21 is provided, it is possible to expand the heat transfer area and improve the heat transfer coefficient between the impurity remover 3 and the exhaust gas flowing through the exhaust gas path 20. The temperature of the impurity remover 3 can be quickly set to a desired temperature.

Further, the fuel cell system according to Embodiment 2 is configured such that, in the configuration described above, the reformer 4 has an evaporator 9 for vaporizing water supplied for use in the steam reforming reaction. It may be.

According to this configuration, since the evaporator 9 is provided and the reformer 4 can perform the steam reforming reaction of the fuel gas, a fuel cell system with excellent fuel efficiency can be realized.

Further, the fuel cell system according to Embodiment 2 may be configured such that the impurity remover 3 is detachably provided in the fuel cell system in the configuration described above.

According to this configuration, since the impurity remover 3 is detachably provided in the fuel cell system, the impurity remover 3 can be easily replaced when the desulfurization catalyst charged in the impurity remover 3 deteriorates. it can. Therefore, further long-term operation of the fuel cell system can be facilitated.

Further, the fuel cell system according to Embodiment 2 has the above-described configuration, and a housing 7 that houses at least the fuel cell 6, the combustion unit 23, the reformer 4, the air heat exchanger 5, and the impurity remover 3, A first heat insulating part 22 disposed on the inner wall of the housing 7, and at least a part of the impurity remover 3 may be disposed within the first heat insulating part 22.

Further, the fuel cell system according to Embodiment 2 accommodates at least the fuel cell 6, the combustion unit 23, the reformer 4, the air heat exchanger 5, the impurity remover 3, and the exhaust gas heat exchanger 21 in the configuration described above. And a first heat insulating portion 22 disposed on the inner wall of the housing 7, and at least a part of the impurity remover 3 and the exhaust gas heat exchanger 21 are disposed in the first heat insulating portion 22. It may be configured to be.

According to this configuration, since at least a part of the impurity remover 3 and the exhaust gas heat exchanger 21 is disposed in the first heat insulating portion 22, heat radiation from the impurity remover 3 or the exhaust gas heat exchanger 21 can be suppressed. . Therefore, the impurity remover 3 can be easily heated to a desired temperature.

Further, the fuel cell system according to Embodiment 2 may be configured to further include a fan 25 that cools the impurity remover 3 outside the housing 7 in the configuration described above.

According to this configuration, since the fan 25 is provided, when the impurity remover 3 is excessively heated, it can be easily cooled by forced convection from the fan 25.

In addition, the fuel cell system according to Embodiment 2 is provided in the recycling path 19 and the boosting section 2 that boosts the raw material flowing through the raw material gas path 1 and supplies it to the impurity remover 3 in the configuration described above. And a condenser 24 that condenses moisture contained in the fuel flowing through the recycle path 19, and the recycle path 19 may be configured to guide a part of the fuel to the upstream side of the booster 2 in the source gas path 1. .

According to this configuration, the condenser 24 is provided in the recycling path 19. For this reason, when the fuel flowing through the recycling path 19 is lowered in temperature, water can be collected by the condenser 24, so that water clogging in the path due to condensed water can be suppressed. Further, the recycle path 19 is configured to guide part of the fuel to the upstream side of the booster 2. For this reason, this fuel can be guided to the pressure-increasing unit 2 in a state in which moisture generated by the low temperature of the fuel is recovered by the condenser 24. Therefore, it is possible to suppress problems such as corrosion or breakage of the booster 2 due to moisture.

By the way, for example, the catalyst filled in the impurity remover 3 such as a desulfurizer is deteriorated by use, and therefore needs to be replaced. However, for example, in the configuration of the fuel cell system disclosed in Patent Documents 1 to 3, since the impurity remover 3 is installed in the internal space of the housing (for example, the heat insulating tank 102 of Patent Document 1), impurities There was a problem that it was difficult to remove the remover 3 itself.

Further, for example, as in the configuration shown in the modification 4 of the second embodiment, the upper surface of the housing 7 provided with the impurity remover 3 can be removed from the main body of the housing 7. It may be possible to replace the impurity remover 3. However, even in such a configuration, when the size of the housing 7 is large, it is difficult to remove the upper surface from the housing 7, and the impurity remover 3 may not be easily removed.

Therefore, the inventor has made it possible to easily remove the impurity remover 3 and studied the configuration of the fuel cell system that can be easily manufactured and maintained. As a result, the fuel cell system according to Embodiment 1 described above has been studied. As described above, it has been found that it is effective to adopt a configuration in which the impurity remover 3 is stored in the container 27.

Hereinafter, as a configuration in which the impurity remover 3 is stored in the container 27, a configuration different from the first embodiment will be specifically described as a third embodiment. The configuration of the third embodiment will be described by comparison with the second embodiment having a more similar configuration.

(Embodiment 3)
A fuel cell system according to Embodiment 3 will be described with reference to FIGS. 16 and 17. 16 and 17 are schematic views showing an example of the configuration of the fuel cell system according to the third embodiment. In FIG. 16, the structure when the fuel cell system which concerns on Embodiment 3 is seen from the side part is shown typically. FIG. 17 shows an example of a configuration when the container 27 described later is separated from the casing 7 in the fuel cell system shown in FIG.

The fuel cell system according to Embodiment 3 differs from the fuel cell system according to Embodiment 2 shown in FIGS. That is, in the fuel cell system according to the second embodiment, the impurity remover 3 is accommodated in the first heat insulating portion 22, whereas in the fuel cell system according to the third embodiment, the impurity remover 3 is accommodated. It is different in that it is accommodated in the container 27.

In the fuel cell system according to the second embodiment, the impurity remover 3 is disposed below the right side surface of the casing 7, whereas in the fuel cell system according to the third embodiment, the upper surface of the casing 7 is arranged. It differs also in the point arrange | positioned in the approximate center part (position facing the combustion part 23) in the side. However, the arrangement of the impurity remover 3 according to the third embodiment is not limited to this, and may be a configuration arranged below the right side surface of the housing 7 as in the fuel cell system according to the second embodiment. Good.

Further, an exhaust gas path 20 is provided for guiding the exhaust gas in the housing 7 into the container 27 and for guiding the exhaust gas circulated in the container 27 to the outside of the container 27, so that the exhaust gas path 20 communicates with the upstream side exhaust gas. It differs also in the point provided with the two exhaust gas path connection parts 31 for connecting the path | route 20a and the waste gas path 20c in a storage device, and connecting the downstream exhaust gas path 20b and the waste gas path 20c in a storage device. That is, an in-container exhaust gas path 20c, which is a flow path for exhaust gas to circulate, is formed in the container 27 so as to surround the outer periphery of the impurity remover 3. The in-container exhaust gas path 20c is configured to be connected to the upstream side exhaust gas path 20a and the downstream side exhaust gas path 20b by the exhaust gas path connection portion 31, respectively.

In the example shown in FIG. 16, among the exhaust gas path connection portions 31, the storage device side exhaust gas path connection portion 31 a is provided on the bottom surface of the storage device 27 serving as a surface in contact with the housing 7. On the other hand, the casing-side exhaust gas path connection portion 31 b is provided with a casing-side exhaust gas path connection portion 31 b at the bottom of a recess formed on the upper surface of the casing 7 so that the container 27 can be accommodated. More specifically, the housing-side exhaust gas path connection portion 31b is a position corresponding to the housing-side exhaust gas path connection portion 31a when the storage device 27 is attached to the housing 7 at the bottom of the recess. 1 is provided in the heat insulating portion 22.

Furthermore, the first connecting portion 30 that connects the housing 7 and the container 27 so that the source gas path 1 and the impurity remover 3 communicate with each other, and the source gas path 14 and the impurity remover 3 after deflowing communicate with each other. This is also different in that a second connection portion 32 for connecting the housing 7 and the container 27 is provided. The first connection part 30 and the second connection part 32 realize the source gas path connection part of the present invention.

That is, in the fuel cell system according to Embodiment 3, the container 27 is connected to the housing 7 by the raw material gas path connection portion (the first connection portion 30 and the second connection portion 32). Further, the container 27 is connected to the housing 7 by two exhaust gas path connection portions 31. Except for the points described above, the configuration is the same as that of the second embodiment.

As shown in FIG. 16, in the fuel cell system according to Embodiment 3, a container 27 that contains the impurity remover 3 is disposed on the upper surface side of the housing 7 and at a position facing the combustion unit 23. . Then, the exhaust gas holding the reaction heat generated in the fuel cell 6 and the combustion heat generated by the combustion of the combustion unit 23 rises toward the upper surface of the casing 7, and first heats the reformer 4 and the evaporator 9. Furthermore, the heat removal with the air heat exchanger 5 proceeds toward the impurity remover 3 above the combustion unit 23 in a state where a part of the heat held is taken away. That is, the exhaust gas goes to the impurity remover 3 in a state where the exhaust gas is lowered to a temperature suitable for the desulfurizing agent charged in the impurity remover 3.

Thus, in the fuel cell system according to Embodiment 3, the reformer 4, the evaporator 9, and the air heat exchanger 5 are configured to take away a part of the heat held by the exhaust gas. For this reason, the exhaust gas produced | generated in the combustion part 23 can be cooled to appropriate temperature, and the calorie | heat amount which the exhaust gas supplied in the storage device 27 can be suppressed can be suppressed.

Therefore, it is not necessary to separately provide a temperature adjusting unit for adjusting the temperature of the impurity remover 3 accommodated in the container 27, and the impurity remover 3 can be easily maintained at an appropriate temperature. Further, since the heat recovered by the air heat exchanger 5 through heat exchange with the exhaust gas can be used for heating the air supplied to the fuel cell, an efficient operation of the fuel cell system can be realized.

Further, the exhaust gas lowered to a temperature suitable for the desulfurizing agent filled in the impurity removing device 3 is formed in the storage device 27 from one end side of the storage device 27 through the upstream exhaust gas path 20a. Into the exhaust gas path 20c. And the exhaust gas which distribute | circulates the waste gas path | route 20c in a storage device and the impurity removal device 3 exchange heat.

Thus, the temperature of the exhaust gas can be lowered to a temperature suitable for the desulfurizing agent 3. For this reason, the radiant heat from the combustion unit 23 or the heat possessed by the exhaust gas, which has become a high temperature due to a system failure or the like, heats the first heat insulating unit 22, and the temperature of the impurity remover 3 is higher than the appropriate temperature. Even if the temperature becomes high, it can be cooled by the exhaust gas flowing through the in-container exhaust gas flow path 20c. Therefore, in the fuel cell system according to Embodiment 3, it is easy to maintain the impurity remover 3 at an appropriate temperature.

The exhaust gas that has flowed through the in-container exhaust gas path 20 c flows out from the other end side of the storage container 27 to the downstream exhaust gas path 20 b and is guided to the outside of the housing 7. As shown in FIG. 16, in the fuel cell system according to Embodiment 3, the impurity remover 3 is arranged in the middle of the exhaust gas path 20 as in the fuel cell system according to Embodiment 2. An upstream exhaust gas path 20 a is disposed upstream of the impurity remover 3, and a downstream exhaust gas path 20 b is disposed downstream of the impurity remover 3.

The container 27 in which the impurity remover 3 is housed is provided with a second heat insulating part (second heat insulating material part) 33 on the inside thereof, and heat is radiated from the inside of the container 27 to the outside and from the outside. It is configured to block heat transfer as much as possible. In the fuel cell system according to Embodiment 3, as shown in FIG. 16, the second heat insulating portion 33 is provided inside the surface of the storage device 27 excluding the bottom surface where the storage device side exhaust gas path connection portion 31 a is formed. Yes. That is, at least a part (the bottom surface in FIG. 16) of the container 27 is provided so as to be detachable from the housing 7 in contact with the first heat insulating portion 22. Furthermore, a second heat insulating portion 33 is provided at least inside the surface of the container 27 that is not in contact with the first heat insulating portion 22.

For this reason, while heating the impurity remover 3 so that it may become a suitable temperature by heat exchange with exhaust gas, the heat of impurities other than the heat which the exhaust gas has transmitted to the impurity remover 3 is interrupted, and the temperature of the impurity remover 3 is made suitable temperature Can be maintained.

In addition, the material of the 2nd heat insulation part 33 may be the same as the material of the 1st heat insulation part 22, and a different material may be sufficient as it. For example, since the second heat insulating portion 33 is not exposed to a higher temperature than the first heat insulating portion 22, the second heat insulating portion 33 does not need to be made of a material that can withstand a higher temperature than the first heat insulating portion 22.

Further, the housing 7 and the container 27 are connected by the first connection part 30, the second connection part 32, and the two exhaust gas path connection parts 31 as described above. And these 1st connection parts 30, the 2nd connection part 32, and the waste gas path connection part 31 are airtight so that the flowing source gas or exhaust gas may not leak.

Further, as shown in FIG. 17, in the fuel cell system according to Embodiment 3, the container 27 is stored in the housing 7 by the first connection part 30, the second connection part 32, and the exhaust gas path connection part 31 described above. Is configured to be removable. The first connection part 30, the second connection part 32, and the exhaust gas path connection part 31 are, for example, the same as the raw material gas path connection part (first connection part 30) and the exhaust gas path connection part 31 of the first embodiment. It may be a fastening member represented by a registered trademark. Thus, by making the container 27 detachable from the casing 7, the impurity remover 3 can be easily attached to the casing 7 when the fuel cell system is manufactured.

Further, even when the catalyst filled in the impurity remover 3 deteriorates after long use, and the impurity remover 3 needs to be replaced, the container 27 is removed from the housing 7 and the container 27 is removed. The impurity remover 3 can be easily taken out from the inside. Therefore, a fuel cell system excellent in maintainability can be configured.

Further, as described above, the impurity remover 3 has a temperature range of 350 to 400 ° C. when the desulfurizing agent is a combination of a Ni—Mo based or Co—Mo based catalyst and zinc oxide, or the desulfurizing agent is copper. In the case of containing zinc and zinc, the temperature range is about 10 to 400 ° C., preferably about 150 to 300 ° C.

By the way, in the fuel cell system according to Embodiment 3, the first connection part 30 (the container side first connection part 30a, the housing side first connection part 30b) and the second connection part 32 (the container side second connection part). 32 a and the housing side second connection tool 32 b) are configured to be accommodated in the first heat insulating part 22 or the second heat insulating part 33. Further, the exhaust gas path connecting portion 31 is also accommodated in the first heat insulating portion 22. Thus, since these connection parts are accommodated in the 1st heat insulation part 22 or the 2nd heat insulation part 33, they are not directly exposed to the high temperature heat inside the housing | casing 7, but the impurity remover 3 and Keep in the same temperature range.

Therefore, the first connection part 30, the second connection part, and the exhaust gas path connection part 31 are exposed to high-temperature heat (for example, heat of 400 ° C. or more) for a long time due to radiant heat from the combustion part 23 or heat of the exhaust gas. It is possible to suppress the occurrence of problems such as thermal degradation.

Further, in the fuel cell system according to Embodiment 3, as shown in FIGS. 16 and 17, the in-container exhaust gas path 20 c is formed in the container 27 so as to surround the outer periphery of the impurity remover 3. However, it is not limited to the configuration in which the in-container exhaust gas path 20c is formed in this way.

For example, when the thickness of the impurity remover 3 is thin, the in-container exhaust gas path 20c may be arranged as shown in FIG. FIG. 18 is a schematic diagram showing an example of the configuration of the fuel cell system according to Embodiment 3 of the present invention. As shown in FIG. 18, one side surface of the impurity remover 3 is in contact with the second heat insulating portion 33, and the in-container exhaust gas path 20 c is formed only on the other side surface side of the impurity remover 3. That is, when the impurity remover 3 is thin enough to be maintained at an appropriate temperature by heat exchange with the exhaust gas flowing through the in-container exhaust gas path 20c formed only on one side surface of the impurity remover 3, the impurity removal is performed. It is not necessary to form the in-container exhaust gas path 20c so as to surround the outer periphery of the container 3. Thus, when the exhaust gas path 20c in the container is formed only on one side surface side of the impurity remover 3, the thickness of the container 3 that accommodates the impurity remover 3 can be further reduced and the size can be reduced. Can be planned.

In the fuel cell system according to Embodiment 3 described above, the impurity remover 3 is configured to be maintained at an appropriate temperature by heat exchange with the exhaust gas flowing through the in-container exhaust gas path 20c. However, for example, the heat possessed by the exhaust gas in the housing 7 and the radiant heat of the combustion unit 23 may be configured to heat the first heat insulating unit 22 so that the temperature of the impurity remover 3 becomes an appropriate temperature. . Such a configuration will be specifically described with reference to FIGS. 19 and 20 as a modification of the third embodiment.

(Modification of Embodiment 3)
Hereinafter, a modification of the fuel cell system according to Embodiment 3 will be described with reference to FIGS. 19 and 20. 19 and 20 are schematic diagrams illustrating an example of the configuration of a fuel cell system according to a modification of the third embodiment. In FIG. 19, the structure when the fuel cell system which concerns on the modification of Embodiment 3 is seen from the side part is shown typically. FIG. 20 shows an example of the configuration when the container 27 is separated from the housing 7 in the fuel cell system shown in FIG.

The fuel cell system according to the modified example of the third embodiment is different from the fuel cell system of the third embodiment described above in that the container exhaust gas path 20c is not formed in the container 27. Another difference is that the upstream exhaust gas path 20a and the downstream exhaust gas path 20b are not configured to be connected to the in-container exhaust gas path 20c by the exhaust gas path connection portion 31. That is, in the fuel cell system according to the modification of the third embodiment, the exhaust gas path 20 extends from the inside of the casing 7 through the first heat insulating portion 22 and extends to the outside of the casing 7.

Except for the points described above, the configuration of the fuel cell system according to the modification of the third embodiment is the same as the configuration of the fuel cell system of the third embodiment. For this reason, the same code | symbol is attached | subjected to the member similar to the fuel cell system which concerns on Embodiment 2, and the description shall be abbreviate | omitted.

As shown in FIG. 19, in the fuel cell system according to the modification of the third embodiment, the container 27 that houses the impurity remover 3 is disposed on the upper surface side of the housing 7 and at a position facing the combustion unit 23. Has been. Then, the exhaust gas holding the reaction heat generated in the fuel cell 6 and the combustion heat generated by the combustion of the combustion unit 23 rises toward the upper surface of the casing 7, and first heats the reformer 4 and the evaporator 9. Furthermore, the heat which is held by the heat exchange with the air heat exchanger 5 is deprived to the upper side of the combustion unit 23. And the heat which the waste gas of the state by which the temperature was lowered, and the radiant heat from the combustion part 23, ie, the combustion heat by combustion of the combustion part 23, heat-transfers the 1st heat insulation part 22, and heats the impurity removal device 3.

Thus, in the fuel cell system according to the modification of the third embodiment, the reformer 4 and the air heat exchanger 5 are configured to take away a part of the heat retained by the exhaust gas. For this reason, the exhaust gas produced | generated in the combustion part 23 can be cooled to desired temperature, and the calorie | heat amount which the exhaust gas transmitted in the container 27 through the 1st heat insulation part 22 can be suppressed can be suppressed.

Therefore, it is not necessary to separately provide a temperature adjusting unit for adjusting the temperature of the impurity remover 3 accommodated in the container 27, and the impurity remover 3 can be maintained at an appropriate temperature. However, as in the fuel cell system according to the third embodiment, the configuration in which the exhaust gas is guided into the container 27 and heat exchange is performed between the exhaust gas and the impurity remover 3 causes the impurity remover 3 to have a higher temperature. In this case, it is advantageous in that the temperature can be lowered to an appropriate temperature by exhaust gas.

The container 27 in which the impurity remover 3 is housed is provided with a second heat insulating portion 33 on the inner side in the same manner as in the configuration shown in the third embodiment, and heat is radiated from the inside of the container 27 to the outside. It is configured to block as much as possible.

Further, the housing 7 and the container 27 are connected by the first connection part 30 and the second connection part 32. And these 1st connection parts 30 and the 2nd connection part 32 are ensuring airtightness so that the flowing raw material gas may not leak.

Further, as shown in FIG. 20, in the fuel cell system according to the modification of the third embodiment, the container 27 can be attached to and detached from the housing 7 by the first connection portion 30 and the second connection portion 32. It is configured. In this way, if the container 27 is configured to be detachable from the housing 7, the container 27 containing the impurity remover 3 can be easily attached to the housing 7 when the fuel cell system is manufactured. Can be attached.

Further, in the fuel cell system according to the modification of the third embodiment, the first connection portion 30 (the container side first connection portion 30a, the housing side first connection portion 30b) and the second connection portion 32 (the container side first connection). 2 connection part 32a and the housing | casing side 2nd connection tool 32b) are comprised so that it may be accommodated in the 1st heat insulation part 22 or the 2nd heat insulation part 33. FIG. Thus, since these connection parts are accommodated in the 1st heat insulation part 22 or the 2nd heat insulation part 33, they are not directly exposed to the high temperature inside the housing | casing 7, but are substantially the same temperature as the impurity removal device 3. Kept in range.

Accordingly, the first connection part 30 and the second connection part 32 are exposed to a high temperature (for example, 400 ° C. or more) for a long time due to the radiant heat from the combustion part 23 and the heat of the exhaust gas. Can be suppressed.

In addition, when the reformer 4 is heated in the casing 7 and the radiant heat, exhaust gas, and the like from the combustion unit 23 are lowered to a desired temperature, the air heat exchanger 5 is necessarily provided as shown in FIG. There is no need. FIG. 21 is a schematic diagram illustrating an example of a configuration of a fuel cell system according to a modification of the third embodiment. However, the configuration including the air heat exchanger 5 is advantageous in that the amount of heat recovered by heat exchange with the exhaust gas can be used for heating the air supplied to the fuel cell.

Further, in the fuel cell system according to the third embodiment and the modified example of the third embodiment, the container 27 is configured to be accommodated in the first heat insulating portion 22 of the housing 7. However, it is not limited to such a configuration.

For example, as shown in FIG. 22, the container 27 may be attached in a state of protruding upward from the upper surface of the housing 7.

FIG. 22 is a diagram illustrating an example of a configuration in which the container 27 is separated from the housing 7 in the fuel cell system according to the modification of the third embodiment. In FIG. 22, for convenience of explanation, the configuration of the fuel cell system according to the modification of the third embodiment is described as an example. However, the fuel cell system according to the third embodiment can be similarly configured. It is.

As shown in FIG. 22, the container 27 has a substantially U-shaped cross section in which both end portions in the longitudinal direction protrude downward. A second heat insulating portion 33 is provided in the portion protruding downward, and the container-side first connection portion 30a and the container-side second in the second heat insulating portion 33 at the end of the protruding portion. Connection portions 32a are provided.

On the other hand, the housing 7 is formed with a recess so as to accommodate the protruding end of the container 27 at a position where the container 27 is attached. And the housing | casing side 1st connection part 30b and the housing | casing side 2nd connection part 32b are each provided in the 1st heat insulation part 22 at the bottom of this recessed part. Moreover, the structure provided with the O-ring 34 which is a sealing member in the position which is the edge of the recessed part formed in the housing | casing 7, and the housing | casing 7 and the container 27 contact | abut may be sufficient.

As described above, the container 27 may be attached so as to protrude outward from the housing 7.

(Method for Manufacturing Fuel Cell System of Embodiments 1 and 3)
Next, a manufacturing method of the fuel cell system will be described with reference to FIG. In particular, a method for manufacturing the fuel cell system according to

Embodiments

1 and 3 in which the impurity remover 3 is stored in the storage device 27 and the storage device 27 can be easily attached to and detached from the fuel cell system will be described. FIG. 23 is a flowchart illustrating an example of a manufacturing method of the fuel cell system according to

Embodiments

1 and 3.

(Manufacturing method of fuel cell system)
Next, a method for manufacturing the fuel cell system according to Embodiment 1 or Embodiment 3 of the present invention described above will be described with reference to FIG. FIG. 23 is a flowchart showing an example of a method for manufacturing a fuel cell system according to Embodiment 1 or Embodiment 3 of the present invention.

Generally, when using an apparatus filled with a catalyst, first, heating and reduction treatment is performed in order to activate the catalyst (for example, Patent Document 7). Therefore, in the manufacturing method of the present invention, heating and reduction treatment are performed before the container 27 is attached to the housing 7.

Specifically, first, as a first step (S1), heat treatment is performed so as to reach a temperature (150 to 300 ° C.) for activating the catalyst charged in the impurity remover 3. This first step (S1) can be performed only on the impurity remover 3 in a state where it is removed from the housing 7, but it can also be performed on the container 27 containing the impurity remover 3. Is possible.

Next, in the second step (S2), a reducing gas containing 0.1 to 5% hydrogen in an inert gas (for example, nitrogen) is stored in the impurity remover 3 or the impurity remover 3 accommodated therein. The reduction process is performed by distributing the flow through the container 27. With this reducing gas, the oxidized catalyst is reduced and the catalyst is activated. In the third step (S3), the container 27 that houses the impurity remover 3 is attached to the second casing 7b.

According to the above manufacturing method, the above-described first step (S1) and second step (S2) necessary for activating the catalyst charged in the impurity remover 3 are accommodated in the second casing 7b. This can be done before the third step of attaching the vessel 27. Therefore, it is not necessary to add components other than the impurity remover 3 or the storage device 27 to the heating and reduction process, so that unnecessary energy and gas consumption can be suppressed. Therefore, an efficient manufacturing method of the fuel cell system can be realized.

From the above invention, many modifications and other embodiments of the present invention are apparent to persons skilled in the art. Accordingly, the foregoing description should be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode of carrying out the invention. The details of the structure and / or function may be substantially changed without departing from the spirit of the invention.

The fuel cell system of the present invention has a configuration capable of managing the impurity remover 3 that performs hydrodesulfurization so as to be in an appropriate temperature range. Therefore, it can be widely applied to fuel cell systems equipped with a desulfurizer that removes sulfur components from raw material gas by hydrodesulfurization.

DESCRIPTION OF SYMBOLS 1 Source gas path | route 2 Booster part 3 Impurity remover 4 Reformer 5 Air heat exchanger 6 Fuel cell 7 Case 7a First case 7b Second case 9 Evaporator 10 Air supply path 11 Reformed water path 12 reformed air path 14 raw material gas path 16 after desulfurization fuel gas supply path 17 air supply path 18 decompression part 19 recycle path 20 exhaust gas path 20a upstream exhaust gas path 20b downstream exhaust gas path 20c exhaust gas path 21 in the container exhaust gas heat exchanger 22 1st heat insulation part 23 Combustion part 24 Condenser 25 Fan 27 Container 30 1st connection part 30a Container side 1st connection part 30b Case side 1st connection part 31 Exhaust gas path connection part 31a Container side exhaust gas path connection part 31b Case side exhaust gas path connection part 32 Second connection part 32a Container side second connection part 32b Case side first connection 33 and the second insulating section

Claims

An impurity remover for removing impurities contained in the supplied source gas;
An evaporator for evaporating supplied water to generate water vapor;
A reformer that generates a reformed gas as a fuel by a reforming reaction from the water vapor generated by the evaporator and the raw material gas from which impurities are removed by the impurity remover;
A fuel cell that generates electricity by a power generation reaction using the supplied air and the fuel;
A combustion section for burning unused fuel in the fuel cell;
A housing for housing the evaporator, the reformer, the fuel cell, and the combustion unit;
In order to discharge the exhaust gas generated by combustion in the combustion section from the inside of the housing to the outside of the fuel cell system, an exhaust gas path through which the exhaust gas flows,
A fuel cell system comprising: a housing space provided in the middle of the exhaust gas path so as to constitute a part of the exhaust gas path and for arranging the impurity remover.
The fuel cell system according to claim 1, wherein the impurity remover is a desulfurizer that removes a sulfur component as an impurity from the raw material gas.
In order to supply the raw material gas to the desulfurizer, a raw material gas path through which the raw material gas is circulated,
A recycling path for guiding the hydrogen-containing gas to the source gas path,
The fuel cell system according to claim 2, wherein the desulfurizer uses a hydrogen-containing gas flowing through the raw material gas path to remove sulfur components as impurities from the raw material gas by hydrodesulfurization.
4. The fuel cell system according to claim 3, wherein a part of the reformed gas generated by the reformer circulates through the recycling path as the hydrogen-containing gas.
The fuel cell system according to any one of claims 1 to 4, wherein the impurity remover has a flat plate shape.
The fuel cell system according to any one of claims 1 to 5, wherein an air heat exchanger that cools the exhaust gas by heat exchange between the air supplied to the fuel cell and the exhaust gas is provided in the housing.
A storage device for forming the storage space for disposing the impurity remover;
The fuel cell system according to claim 1, wherein the container is connected to the housing.
The fuel cell system according to claim 7, wherein the container is configured to be detachable from the housing.
The casing includes at least a first casing that houses the evaporator, the reformer, the fuel cell, and the combustion unit;
A fuel cell system according to any one of claims 1 to 8, further comprising a second casing surrounding an outer periphery of the first casing.
10. The fuel cell system according to claim 9, wherein a heat insulating material is accommodated in at least a part between the first casing and the second casing.
A fuel cell that generates power by a power generation reaction using supplied air and fuel generated from the raw material gas;
A combustion section for burning unused fuel in the fuel cell;
An impurity remover that removes impurities contained in the raw material gas using heat held by exhaust gas generated by combustion in the combustion section;
An evaporator that evaporates the supplied water to generate water vapor;
A reformer that generates a reformed gas as a fuel by a reforming reaction from the water vapor generated by the evaporator and the raw material gas from which impurities are removed by the impurity remover;
A housing for housing the fuel cell, the combustion section, the evaporator, and the reformer;
In order to discharge the exhaust gas generated by combustion in the combustion section from the inside of the housing to the outside of the fuel cell system, an exhaust gas path through which the exhaust gas flows,
A container that is detachable with respect to the housing and is provided so as to constitute a part of the exhaust gas path in the middle of the exhaust gas path, and forms a storage space for arranging the impurity remover; A method of manufacturing a fuel cell system comprising:
A first step of heating the impurity remover or the container containing the impurity remover in a state where the impurity remover is detached from the housing;
A second step of reducing the catalyst charged in the impurity remover;
And a third step of attaching the container to the housing.