JP6387521B2 - Hydrogen generator and fuel cell system using the same - Google Patents

Description

  The present invention uses a hydrocarbon fuel such as city gas or LPG as a raw material gas to generate a gas containing high-concentration hydrogen, and to generate power using the hydrogen generated by the hydrogen generator. The present invention relates to a fuel cell system including a fuel cell.

  A fuel cell system is mainly composed of a hydrogen generator that generates a gas containing high-concentration hydrogen and a fuel cell that generates power using the hydrogen generated by the hydrogen generator. It is common to install and use outdoors due to the combination of

  The hydrogen generator constituting the fuel cell system uses a hydrocarbon-based fuel such as city gas or LPG as a raw material gas, and performs a steam reforming reaction between the raw material gas and water using a reforming catalyst, thereby producing hydrogen, methane, Carbon monoxide (about 10 to 15%), a reforming section that generates reformed gas containing carbon dioxide and water vapor, and carbon monoxide that has a poisoning effect on the fuel cell are removed from the reformed gas. And a carbon oxide removing unit.

  When using a polymer electrolyte fuel cell, it is necessary to remove the carbon monoxide concentration contained in the reformed gas to about 10 ppm. Therefore, the carbon monoxide removal unit is controlled by a shift reaction using a shift catalyst. The carbon monoxide is oxidized by a selective oxidation reaction to reduce the carbon monoxide concentration to about 10 ppm or less by mixing with oxygen using a selective oxidation catalyst by removing the carbon oxide to about 0.5%. Generally, it comprises a selective oxidation part.

  Conventionally, various proposals have been made for hydrogen generators from the viewpoints of miniaturization, high efficiency, improved startability, improved operational stability, and cost reduction by simplifying the structure. For a small and highly efficient hydrogen generator, the reformer and carbon monoxide remover are integrated into a single structure, and a heating burner is installed inside them to dissipate heat to the outside of the hydrogen generator. The heat balance in the device is optimized, and at the same time, the cost is reduced by simplifying the structure.

  In the hydrogen generator disclosed in Patent Document 1, as shown in FIG. 13, a combustion air supply passage 33 that supplies air to a burner 32 provided inside the combustion air cylinder 31 is adjacent to the combustion exhaust gas passage 34. It is configured to exchange heat.

  Here, the combustion air exchanges heat with the combustion exhaust gas so that the air can be preheated. The amount of heat used for preheating the air is reused for heating the reforming catalyst via the combustion exhaust gas, so that the reforming section is heated while maintaining the reforming catalyst in an appropriate temperature distribution. After that, the energy of the combustion exhaust gas is effectively recovered, and the energy efficiency of the hydrogen generator itself is improved.

  Further, the combustion exhaust gas is adjacent to the water evaporation section 35 located outside and the carbon monoxide removal section 36 located outside the combustion exhaust gas, and is configured so that the entire temperature state becomes an optimum state by heat exchange. ing.

  However, the air supplied to the burner 32 is often used outside the fuel cell system, that is, by taking in the outside air at the place where the apparatus is installed. However, the temperature of the outside air changes depending on the day and night and the season, and is considerably large considering the region. change.

For example, even in Japan alone, there are regions where the temperature is 40 ° C. in the summer and other regions where the temperature is −20 ° C. in the winter. Here, when the temperature of the air supplied to the hydrogen generator changes from a high temperature to a low temperature according to the outside air, the temperature balance is adjusted when the heat exchange with the air taken in adjacent to the combustion air supply path 33 is excessive. There is a possibility that the combustion exhaust gas to be maintained, the water evaporation unit 35, and the carbon monoxide removal unit 36 cannot be maintained at an optimum temperature state.

  If the temperature cannot be maintained optimally, for example, if the temperature of the carbon monoxide removal unit 36 is too low or too high, carbon monoxide cannot be sufficiently removed due to the reaction characteristics of the carbon monoxide removal catalyst. In addition to increasing the carbon monoxide in the product gas from the hydrogen generator and exceeding 10 ppm, dew condensation occurs in the combustion exhaust gas flow path 34 due to the temperature of the combustion exhaust gas becoming lower and lower than the dew point of the exhaust gas. There is a possibility of causing corrosion of the combustion exhaust gas flow path 34 in FIG.

  In the hydrogen generator disclosed in Patent Document 2, as shown in FIG. 14, a burner 4 to which a fuel gas containing a combustible gas and combustion air are supplied, and a combustion exhaust gas flow path 17 from the burner 4 are disposed inside. A reforming catalyst layer 9 which is disposed outside the second cylinder 20 and generates reformed gas containing hydrogen by supplying raw material gas and water vapor, and reforming from the reforming catalyst layer 9. It has a shift catalyst layer 10 for removing carbon monoxide contained in the gas and a selective oxidation catalyst layer 11.

  A combustion exhaust gas flows outside the air passage 2 to which combustion air is supplied, and a heat insulating material 5 that suppresses heat transfer is provided between the air passage 2 and the combustion exhaust passage 17.

  As a result, even if the outside air temperature of the apparatus changes and the air temperature supplied to the burner 4 changes, the combustion exhaust gas disposed further around the heat insulating material 5 by the heat insulating material 5 installed around the air flow path 2. Temperature effects on the water evaporation section 8, the shift catalyst layer 10 and the selective oxidation catalyst layer 11 can be minimized, and the optimum temperatures can be maintained, so that stable operation of the hydrogen generator is realized. be able to.

JP 2007-55892 A JP 2007-274914 A

  However, in a hydrogen generator that has a heat insulation configuration that suppresses heat transfer between the air flow path and the combustion exhaust gas flow path, the preheating of the combustion air that is performed by the heat of the combustion exhaust gas is suppressed and recovered to the combustion air side. The amount of heat of the combustion exhaust gas is reduced. As a result, there is a problem that the amount of heat of the combustion exhaust gas that is not recovered by the combustion air and discharged from the exhaust port increases, thereby deteriorating the energy efficiency of the hydrogen generator.

  At this time, in order to avoid a decrease in the energy efficiency of the hydrogen generator, it is necessary to increase the heat transfer area necessary for recovering the heat of the combustion exhaust gas. As a result, the hydrogen generator is large and the cost is high. There was a problem.

  The present invention has been made in view of the above problems, and even if the air temperature in the air flow path supplied to the burner changes due to a change in the outside air temperature of the device, etc., the adjacent combustion exhaust gas, water evaporation section, An object of the present invention is to provide a hydrogen generator with high energy efficiency by recovering the heat of combustion exhaust gas to the combustion air side while having a structure that can realize stable operation without affecting the temperature of the carbon oxide removal unit It is.

  In order to solve the above-described conventional problems, a hydrogen generator of the present invention includes a reforming catalyst layer that is supplied with a raw material gas and steam and generates reformed gas by a steam reforming reaction, and is included in the reformed gas. A carbon monoxide removal layer that removes carbon monoxide, a burner that is supplied with fuel gas and combustion air and emits combustion exhaust gas, the combustion exhaust gas that flows in a direction opposite to the flow direction of the combustion air, and the A first wall that partitions the combustion air flow path and the combustion exhaust gas flow path so that heat exchange with the combustion air is possible, the source gas flowing in a direction opposite to the flow direction of the combustion exhaust gas, and The flow direction of the source gas and the water vapor is a second wall that partitions the flow path of the combustion exhaust gas and the source gas and the water vapor channel so that the water vapor and the combustion exhaust gas can exchange heat. The reformed gas flowing in the opposite direction and the front A third wall that partitions the flow path of the raw material gas and the water vapor and the flow path of the reformed gas so that the raw material gas and the steam can exchange heat, and the reforming catalyst layer includes the combustion Provided on the downstream side of the flow path of the raw material gas and the water vapor so as to exchange heat with the exhaust gas, and the carbon monoxide removal layer of the reformed gas so as to exchange heat with the raw material gas and the water vapor. A hydrogen generation device provided on the downstream side of the flow path, wherein the first wall and the second wall are interposed in a peripheral portion of the third wall facing the carbon monoxide removal layer. The heat exchange performance with the combustion air is such that the portion of the third wall facing the carbon monoxide removal layer and the combustion air through the first wall and the second wall It has the structure which has a part which becomes higher than the heat exchange performance in between.

  With this configuration, the recovery of the heat of combustion exhaust gas to the combustion air and the excessive cooling of the carbon monoxide layer removal layer can be prevented, the temperature can be stabilized, hydrogen can be generated stably, and the energy It becomes possible to constitute a highly efficient hydrogen generator.

  According to the present invention, even if the outside air temperature of the apparatus changes and the air temperature supplied to the burner changes, the temperature influence on the combustion exhaust gas, the water evaporation section, the shift catalyst layer and the selective oxidation catalyst layer is minimized, Each optimum temperature can be maintained, and by recovering and reusing the thermal energy of the combustion exhaust gas and the product gas, a highly efficient and stable operation of the hydrogen generator can be realized.

Schematic sectional view showing an example of a hydrogen generator in Embodiment 1 of the present invention Main part schematic sectional drawing which shows the example which extended the heat-transfer promotion wall of the hydrogen generator in Embodiment 1 of this invention to the upstream of the air flow path rather than the example of FIG. Main part schematic sectional drawing which shows the example which shifted arrangement | positioning of the heat-transfer promotion wall of the hydrogen generator in Embodiment 1 of this invention to the upstream of an air flow path rather than the example of FIG. 1 is a schematic cross-sectional view of an essential part showing an example of a structure in which a heat transfer promoting wall of a hydrogen generator in Embodiment 1 of the present invention is fixed to a fuel gas supply pipe on the upstream side of an air flow path. 1 is a schematic cross-sectional view of an essential part showing an example of a structure in which a heat transfer promoting wall of a hydrogen generator in Embodiment 1 of the present invention is fixed to a fuel gas supply pipe on the downstream side of an air flow path. Unevenness for promoting heat transfer partially on both the inner peripheral surface and the outer peripheral surface of the first wall that partitions the combustion air flow path and the combustion exhaust gas flow path of the hydrogen generator in Embodiment 1 of the present invention The main part schematic sectional drawing which shows the example which provided 2 shows an example in which unevenness for promoting heat transfer is partially provided on the outer peripheral surface of the first wall that partitions the combustion air flow path and the combustion exhaust gas flow path of the hydrogen generator in Embodiment 1 of the present invention. Schematic sectional view of main parts 2 shows an example in which unevenness for promoting heat transfer is partially provided on the outer peripheral surface of the first wall that partitions the combustion air flow path and the combustion exhaust gas flow path of the hydrogen generator in Embodiment 1 of the present invention. Schematic sectional view of main parts Schematic cross-sectional view showing an example of a hydrogen generator in Embodiment 2 of the present invention Main part schematic sectional drawing which shows the modification of the hydrogen generator in Embodiment 2 of this invention Schematic sectional view of a hydrogen generator in Embodiment 3 of the present invention Block diagram showing an example of a fuel cell system in Embodiment 4 of the present invention Schematic cross-sectional view of a conventional hydrogen generator disclosed in Patent Document 1 Schematic cross-sectional view of a conventional hydrogen generator disclosed in Patent Document 2

  According to a first aspect of the present invention, there is provided a hydrogen generator, a reforming catalyst layer that is supplied with a raw material gas and steam to generate a reformed gas by a steam reforming reaction, and that removes carbon monoxide contained in the reformed gas. Heat exchange is possible between the carbon oxide removal layer, a burner that is supplied with fuel gas and combustion air and emits combustion exhaust gas, and the combustion exhaust gas that flows in the direction opposite to the flow direction of the combustion air and the combustion air In this way, the first wall partitioning the combustion air flow path and the combustion exhaust gas flow path, the raw material gas flowing in the direction opposite to the flow direction of the combustion exhaust gas, the water vapor, and the combustion exhaust gas are The reformed gas that flows in a direction opposite to the flow direction of the source gas and the water vapor, and a second wall that partitions the flow path of the combustion exhaust gas and the flow path of the source gas and the water vapor so that heat exchange is possible And the raw material gas and the water vapor A third wall that divides the flow path of the raw material gas and the water vapor and the flow path of the reformed gas so that they can be exchanged, so that the reformed catalyst layer can exchange heat with the combustion exhaust gas. Provided on the downstream side of the flow path of the raw material gas and the water vapor, and the carbon monoxide removal layer is provided on the downstream side of the flow path of the reformed gas so as to be able to exchange heat with the raw material gas and the water vapor. In the hydrogen generator, the heat of the combustion air via the first wall and the second wall is formed around the portion of the third wall facing the carbon monoxide removal layer. The exchange performance is more than the heat exchange performance between the portion of the third wall facing the carbon monoxide removal layer and the combustion air through the first wall and the second wall. It has a configuration that has a higher portion.

  With this configuration, the recovery of the heat of combustion exhaust gas to the combustion air and the excessive cooling of the carbon monoxide layer removal layer can be prevented, the temperature can be stabilized, hydrogen can be generated stably, and the energy It becomes possible to constitute a highly efficient hydrogen generator.

  In particular, the second aspect of the present invention is the hydrogen generator according to the first aspect of the present invention, wherein heat transfer is promoted to promote heat transfer from the combustion air flow path to the combustion exhaust gas flow path through the first wall. In the first wall, a portion is provided so as to avoid a region including a portion in a position where heat exchange is most easily performed with a portion of the third wall facing the carbon monoxide removal layer.

  With such a configuration, the temperature of the carbon monoxide removal layer is stabilized while suppressing the influence of the combustion air temperature change to the portion facing the carbon monoxide removal layer through the heat transfer promotion portion, and the heat transfer By recovering the heat of the combustion exhaust gas into the combustion air via the promotion unit and reusing it for heating the reforming catalyst, it becomes possible to generate hydrogen with high efficiency and stability.

  In particular, the third aspect of the present invention is the hydrogen generator according to the second aspect of the invention, wherein the heat transfer promoting portion is located on the first wall, the portion facing the carbon monoxide removal layer on the third wall. It is set as the structure provided in the upstream or downstream of the flow path of the said combustion air rather than the part in the position which is easy to heat-exchange.

  With such a configuration, the temperature of the carbon monoxide removal layer is stabilized while suppressing the influence of the combustion air temperature change to the portion facing the carbon monoxide removal layer through the heat transfer promotion portion, and the heat transfer By recovering the heat of the combustion exhaust gas into the combustion air via the promotion unit and reusing it for heating the reforming catalyst, it becomes possible to generate hydrogen with high efficiency and stability.

  According to a fourth aspect of the invention, in particular, in the hydrogen generator of the second or third aspect of the invention, the heat transfer promoting portion is provided in the vicinity of a surface of the first wall that contacts the combustion air. The structure includes an accelerating wall and a guiding portion that guides the combustion air to a gap between the first wall and the heat transfer accelerating wall.

  With this configuration, the combustion air is guided to flow along the vicinity of the first wall, and the flow velocity is increased by reducing the flow passage area of the combustion air. It is possible to promote heat transfer to the third wall through the wall, thereby recovering the heat of the combustion exhaust gas into the combustion air and reusing it for heating the reforming catalyst. And it becomes possible to produce | generate hydrogen stably.

  According to a fifth aspect of the invention, in particular, in the hydrogen generator of the fourth aspect of the invention, the heat transfer promoting wall is attached to a fuel gas supply pipe that supplies the fuel gas to the burner via the induction portion. To do.

  With such a configuration, the heat transfer promoting wall and the guiding portion are configured integrally with the burner and the fuel gas supply pipe, and it is possible to configure a hydrogen generator that is simple and easy to assemble.

  In a sixth aspect of the invention, in particular, in the hydrogen generator according to the second or third aspect of the invention, the heat transfer accelerating portion is a surface in contact with the combustion air or a surface in contact with the combustion exhaust gas in the first wall. It is set as the structure which makes the surface area of at least any one of these wide.

  With this configuration, the heat transfer area from the combustion air to the combustion exhaust gas via the first wall is increased, and the heat transfer from the combustion exhaust gas to the combustion air via the first wall is promoted. Thereby, it becomes possible to generate hydrogen with high efficiency by recovering the heat of the combustion exhaust gas into the combustion air and reusing it for heating the reforming catalyst.

  In a seventh aspect of the invention, in particular, in the hydrogen generator according to any one of the second to sixth aspects of the invention, the heat transfer promoting portion is provided downstream of the combustion air from the carbon monoxide removal layer. The configuration.

  With such a configuration, it is possible to avoid the temperature of the combustion exhaust gas from excessively decreasing near the exhaust outlet on the downstream side of the combustion exhaust gas flow path and avoid unstable operation of the apparatus due to condensation, and stably generate hydrogen. It becomes possible.

In an eighth aspect of the invention, in particular, in the hydrogen generator according to any one of the second to sixth aspects of the invention, the carbon monoxide removal layer includes a shift catalyst layer that reduces carbon monoxide by a shift reaction. The heat promotion part is configured to be provided on the downstream side of the combustion air with respect to the shift catalyst layer.

  With this configuration, the temperature is stabilized by suppressing the influence of the change in the combustion air temperature to the portion facing the shift catalyst layer, which is the carbon monoxide removal layer, through the heat transfer promoting portion, and hydrogen is stably supplied. Can be generated.

In a ninth aspect of the invention, in particular, in the hydrogen generator according to any one of the second to sixth aspects of the invention, the carbon monoxide removal layer is mixed with an oxidizing agent containing oxygen in the reformed gas to perform monoxide. A selective oxidation catalyst layer that removes carbon is included, and the heat transfer promoting portion is provided downstream of the combustion air from the selective oxidation catalyst layer.

With such a configuration, it becomes possible to stabilize the temperature by suppressing the influence of the combustion air temperature change to the portion facing the selective oxidation catalyst layer that is the carbon monoxide removal layer via the heat transfer promoting portion, It becomes possible to generate hydrogen stably.

  According to a tenth aspect of the invention, in particular, in the hydrogen generator according to any one of the seventh to ninth aspects, the heat transfer promoting portion is provided upstream of the combustion air with respect to the reforming catalyst layer. And

  With this configuration, the amount of heat exchange between the combustion air flow path and the combustion exhaust gas flow path can be reduced in the vicinity of the reforming catalyst layer, thereby reducing the temperature of the combustion exhaust gas near the reforming catalyst layer. As a result, the heating of the reforming catalyst layer is prevented from being hindered, and hydrogen can be efficiently generated.

In an eleventh aspect of the invention, in particular, in the hydrogen generator of any one of the second to sixth aspects of the invention, the carbon monoxide removal layer includes a shift catalyst layer that reduces carbon monoxide by a shift reaction, and the shift catalyst. And a selective oxidation catalyst layer that removes carbon monoxide by mixing an oxidant containing oxygen into the shift gas from the bed, and the heat transfer promoting portion is arranged upstream of the combustion air from the shift catalyst layer. A configuration is provided on the downstream side of the combustion air with respect to the selective oxidation catalyst layer.

  With such a configuration, the temperature is stabilized by suppressing the influence of the change in the combustion air temperature to the portion facing the shift catalyst layer that is the carbon monoxide removal layer and the selective oxidation catalyst layer through the heat transfer promoting portion. It becomes possible.

  In addition, by cooling the gas flowing into the selective oxidation catalyst layer, local temperature rise due to the selective oxidation reaction can be mitigated, and the selective oxidation catalyst can be prevented from deteriorating due to high temperature, and hydrogen can be generated stably. It becomes possible.

  In a twelfth aspect of the invention, in particular, in the hydrogen generator of the first aspect of the invention, heat transfer suppression that suppresses heat transfer from the combustion air flow path to the combustion exhaust gas flow path through the first wall. In the first wall, a portion is provided in a region including a portion at a position where heat exchange is most easily performed with a portion of the third wall facing the carbon monoxide removal layer.

  With this configuration, heat transfer from the part facing the carbon monoxide removal layer to the combustion air is suppressed, and the temperature is stabilized by minimizing the influence of the temperature change of the combustion air on the carbon monoxide removal layer. And stable generation of hydrogen.

  According to a thirteenth aspect of the present invention, in the hydrogen generator of the twelfth aspect of the invention, the region where the heat transfer suppression portion is provided faces the carbon monoxide removal layer on the third wall in the first wall. It is configured to include a region on the upstream side of the flow path of the combustion air with respect to the portion that is most easily exchanged with the portion.

  With this configuration, the temperature of the combustion exhaust gas is excessively lowered in the vicinity of the exhaust port from which the combustion exhaust gas is exhausted from the apparatus, and the operation of the apparatus is prevented from becoming unstable due to condensation, and hydrogen is stably generated. It becomes possible.

  According to a fourteenth aspect of the invention, in particular, in the hydrogen generator of the twelfth or thirteenth aspect, the heat transfer suppression portion is provided on a surface of the first wall facing the combustion air passage. To do.

  With this configuration, the heat exchange between the combustion exhaust gas and the combustion air through the first wall is suppressed, thereby suppressing the influence of the temperature change of the combustion air on the carbon monoxide removal layer, By stabilizing the temperature of the carbon monoxide removal layer, it becomes possible to generate hydrogen stably.

  According to a fifteenth aspect of the invention, in the hydrogen generator according to the fourteenth aspect of the invention, the heat transfer suppression portion is constituted by a heat insulating material provided on a surface of the first wall facing the combustion air passage.

  With this configuration, the heat exchange between the combustion exhaust gas and the combustion air through the first wall is suppressed, thereby suppressing the influence of the temperature change of the combustion air on the carbon monoxide removal layer, By stabilizing the temperature of the carbon monoxide removal layer, it becomes possible to generate hydrogen stably.

  In a sixteenth aspect of the present invention, in particular, in the hydrogen generator according to the fourteenth aspect of the present invention, an air insulation layer is formed between the heat transfer suppression portion and a surface of the first wall facing the combustion air passage. It consists of a heat shield.

  With this configuration, the heat exchange between the combustion exhaust gas and the combustion air through the first wall is suppressed, thereby suppressing the influence of the temperature change of the combustion air on the carbon monoxide removal layer, By stabilizing the temperature of the carbon monoxide removal layer, it becomes possible to generate hydrogen stably.

  According to a seventeenth aspect of the invention, in particular, in the hydrogen generator according to any one of the first to sixteenth aspects of the invention, the burner is arranged in the innermost part, the first wall is arranged outside the burner, The second wall is disposed outside the first wall, and the third wall is disposed outside the second wall.

  With this configuration, the high temperature burner is placed in the center of the configuration, and the periphery is surrounded by a relatively low temperature flow path, thereby suppressing an increase in the surface temperature of the hydrogen generation device, and a highly efficient hydrogen generation device with less heat dissipation. Can be configured.

  According to an eighteenth aspect of the invention, in particular, the hydrogen generator according to the seventeenth aspect of the invention is configured such that the first wall, the second wall, and the third wall are concentrically centered on the burner. The configuration is arranged.

  With such a configuration, in each cross section perpendicular to the flow of the flow path, the distance from each part of the flow path and the burner disposed at the center is equal, and heat is evenly transferred from the burner to each part of the flow path. It becomes possible to avoid deterioration of the catalyst due to local high temperature and damage to the structure due to thermal stress.

  In order to solve the above conventional problems, the fuel cell system of the present invention is supplied from the hydrogen generator of any one of the first to eighteenth inventions, the oxidizing gas containing oxygen, and the hydrogen generator. It is set as the structure provided with the fuel cell which produces electric power using the generated gas.

  With this configuration, it is possible to form a fuel cell system capable of generating hydrogen efficiently and stably in the hydrogen generator, and thereby generating electricity with high efficiency and stability.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the present embodiment.

(Embodiment 1)
FIG. 1 is a schematic cross-sectional view of a hydrogen generator in Embodiment 1 of the present invention.

  As shown in FIG. 1, the hydrogen generator according to the present embodiment is formed inside the first cylinder 21 that is the first wall from the fuel gas supplied from the fuel gas supply unit 1 and the air fan 3. It has a burner 4 that mixes with the air supplied through the air flow path 2 to form a flame.

The combustion exhaust gas generated in the burner 4 passes through the combustion exhaust gas flow path 17 formed between the first cylinder 21 and the second cylinder 20 which is the second wall located outside the first cylinder 21. The air is exhausted from the exhaust port 13 through the exhaust port 13.

  Here, in the air flow path 2 inside the first cylinder 21, the cylindrical heat transfer promotion wall 22 and the guide portion 23 are provided with the shift catalyst layer 10 and the selective oxidation catalyst layer 11 that are carbon monoxide removal layers. It is arranged downstream of the air flow path 2, which is a position avoided, and the air from the air fan 3 is configured to flow between the heat transfer promoting wall 22 and the first cylinder 21.

  The heat transfer promotion wall 22 and the guide portion 23 may be installed at any position as long as the air flow path 2 is located in the vicinity of the shift catalyst layer 10 and the selective oxidation catalyst layer 11, and the air flow path 2 shown in FIG. You may install not only downstream but upstream.

  Outside the second cylinder 20, a water evaporation unit 8 to which the source gas from the source gas supply unit 6 and the water from the water supply unit 7 are supplied is provided. The water evaporation part 8 is formed of a second cylinder 20 and a third cylinder 25 which is a third wall disposed outside the second cylinder 20. The mixed gas of the raw material gas and water vapor sent from the water evaporation unit 8 is supplied to the reforming catalyst layer 9 located outside the second cylinder 20 and below the water evaporation unit 8.

  The reformed gas sent out from the reforming catalyst layer 9 is supplied to the shift catalyst layer 10 which is a carbon monoxide removal layer disposed outside the water evaporation section 8, and the shift gas sent from the shift catalyst layer 10 is After being mixed with the air from the selective oxidation air supply unit 15, it is supplied to the selective oxidation catalyst layer 11, which is also a carbon monoxide removal layer, located above the shift catalyst layer 10 outside the water evaporation unit 8. .

  The product gas exiting the selective oxidation catalyst layer 11 is sent from the product gas outlet 12 as a product gas containing a high concentration of hydrogen having a carbon monoxide concentration of 10 ppm or less from the hydrogen generator.

  In the hydrogen generator configured as described above, the burner 4 having a high temperature is arranged at the center of the apparatus, and the surroundings are surrounded by a relatively low temperature flow path and a catalyst layer, thereby increasing the surface temperature of the hydrogen generator. Therefore, it is possible to configure a highly efficient hydrogen generator with low heat dissipation.

  Further, in this embodiment, the container of the apparatus is formed of a cylinder, and each part of the flow path is evenly heated from the burner 4 disposed at the center, and deterioration of the catalyst due to local high temperature and thermal stress. It is possible to avoid the damage of the structure due to the above and to stably generate hydrogen.

  The carbon monoxide removal layer may be anything as long as it can remove carbon monoxide in the reformed gas by a catalytic reaction, and is not limited to the two-layer configuration of the shift catalyst layer 10 and the selective oxidation catalyst layer 11. .

  Here, the temperature of the reformed gas from the reforming catalyst layer 9 is detected by the reformed gas temperature sensor 14, and the fuel gas and air amount supplied to the burner 4 are controlled by the fuel gas supply unit 1 and the air fan 3. Can be done.

  The fuel gas supply unit 1, the air fan 3, the raw material gas supply unit 6, the water supply unit 7, and the selective oxidation air supply unit 15 are each supplied with a combustible gas such as fuel gas, raw material gas, water, off-gas, etc. It is possible to adjust the flow rate of the air), and it may be a supply pump (driving means) capable of changing the discharge flow rate of the supply, and is provided in the supply source and the downstream flow path. It may be a fluid mechanism combined with a supply flow rate adjusting valve.

The reformed gas temperature sensor 14 can measure the temperature of a thermistor, a thermocouple, etc. installed in a place where the reformed gas temperature from the reforming catalyst layer 9 can be representatively measured (for example, near the outlet of the shift catalyst layer 10). Anything is acceptable.

  Next, each part operation | movement of a hydrogen generator in the said structure is demonstrated.

  In the burner 4, the fuel gas and the air are mixed, and a high voltage discharge is performed on the mixed gas (a configuration is not shown) to form a flame, thereby producing a high-temperature combustion exhaust gas to produce the second cylinder. It is supplied to the combustion exhaust gas flow path 17 between 20 and the first cylinder 21.

  The water evaporation section 8 supplied with water and raw material gas receives the heat from the combustion exhaust gas flowing inside the second cylinder 20 to evaporate the water, and simultaneously flows in the same flow path of the water evaporation section 8. The raw material gas is mixed and supplied to the reforming catalyst layer 9 as a mixed gas.

  The reforming catalyst layer 9 is heated to a high temperature (generally 600 to 700 ° C.) with a high-temperature combustion exhaust gas flowing inside the second cylinder 20, and is supplied with a mixed gas of a raw material gas and water vapor. A reformed gas containing hydrogen, carbon monoxide, carbon dioxide, etc. is generated by the quality reaction.

  The shift catalyst layer 10 is heated and maintained at a temperature (150 to 300 ° C.) optimum for the shift reaction by the water evaporation section 8 which is heat balanced by heat exchange with the combustion exhaust gas flowing inside the second cylinder 20, and reforming is performed. The carbon monoxide concentration is reduced (around 0.5%) by changing carbon monoxide (10-15%) in the gas to carbon dioxide.

  The selective oxidation catalyst layer 11 is also maintained at the optimum temperature (around 150 ° C.) for the selective oxidation reaction by the water evaporation section 8 which is heat balanced by heat exchange with the combustion exhaust gas flowing inside the second cylinder 20 and is selected as a modified gas. By mixing the air from the oxidant air supply unit 15, the carbon monoxide in the modified gas is in a state of extremely low concentration of 10 ppm or less by a selective oxidation reaction.

  Here, the hydrogen generator controls the reformed gas temperature at the outlet of the reforming catalyst layer 9 to be constant so that each catalyst layer can realize an optimum temperature state with a simple configuration and control.

  That is, in a simple structure configuration in which the reforming catalyst layer 9, the shift catalyst layer 10, and the selective oxidation catalyst layer 11 are integrated, the fuel gas supply unit 1 and the air fan 3 according to the output from the reformed gas temperature sensor 14. By controlling this, the amount of combustion in the burner 4 is changed so that the output of the reformed gas temperature sensor 14 becomes constant.

  If the temperature of the reformed gas temperature sensor 14 is constant, the reformed gas temperature supplied to the shift catalyst layer 10 is constant, and if the temperature of the shift catalyst layer 10 is constant, it is supplied to the selective oxidation catalyst layer 11. The metamorphic gas temperature to be produced is also constant.

  Therefore, if the reformed gas temperature sensor 14 is controlled to be constant, the entire temperature from the reforming catalyst layer 9 to the selective oxidation catalyst layer 11 can be maintained at an optimum temperature for the catalytic reaction. Achieves carbon removal.

  Here, the temperature of the reforming catalyst layer 9 is the temperature of the combustion exhaust gas flowing inside the reforming catalyst layer 9 from the burner 4, that is, the inside of the second cylinder 20, and the reforming flowing around the reforming catalyst layer 9. Although it depends on the reformed gas exiting the catalyst layer 9, the reformed gas temperature sensor 14 detects the temperature of the reformed gas exiting the reformed catalyst layer 9, and therefore reforms flowing around the reformed catalyst layer 9. The gas temperature is also controlled.

  Therefore, if the reformed gas temperature sensor 14 is controlled to a constant temperature, the temperature of the entire reforming catalyst layer 9 can be maintained at a stable temperature.

  On the other hand, the shift catalyst layer 10 and the selective oxidation catalyst layer 11 are surrounded by a high-performance heat insulating material 18, and the hydrogen generator covered with the heat insulating material 18 is disposed in the casing of the system. The temperature of the shift catalyst layer 10 and the selective oxidation catalyst layer 11 is determined by the water evaporation section 8 that is thermally balanced by heat exchange with the combustion exhaust gas.

  Here, since the burner 4 is located in the vicinity of the upstream portion of the reforming catalyst layer 9, the burner 4 is disposed inside the combustion exhaust gas channel 17 inside the water evaporation portion 8 located above the reforming catalyst layer 9. The air flow path 2 to be supplied is located.

  Here, the air flowing through the air flow path 2 exchanges heat with the combustion exhaust gas flowing through the combustion exhaust gas flow path 17 so that the air can be preheated. Since the amount of heat used for preheating the air is reused for heating the reforming catalyst via the combustion exhaust gas, the combustion exhaust gas flow path 17 is maintained while maintaining the reforming catalyst in an appropriate temperature distribution. Thus, the energy of the combustion exhaust gas discharged from the vicinity of the reforming catalyst layer 9 can be effectively recovered, and the energy efficiency of the hydrogen generator itself can be improved.

  Here, the air is taken in from the outside air outside the apparatus, and the outside air changes from a low temperature to a high temperature (for example, -20 to 40 ° C.) depending on the season and region. At this time, the temperature of the combustion exhaust gas is the air fan 3. Under the influence of the air flowing through the supplied air flow path 2, the temperature of the combustion exhaust gas changes.

  Moreover, the temperature change of combustion exhaust gas causes the temperature change of the water evaporation part 8, and changes the temperature of the shift catalyst layer 10 or the selective oxidation catalyst layer 11.

  At this time, since the temperature of the outlet of the reforming catalyst layer 9 is controlled to be constant, the selective oxidation is located away from the outlet of the reforming catalyst layer 9 and is located near the inlet of air whose temperature varies depending on the outside air temperature. The catalyst layer 11 and the product gas after the selective oxidation catalyst layer 11 are more greatly affected by the temperature change of the air.

  If the temperature of the shift catalyst layer 10 or the selective oxidation catalyst layer 11 changes, there is a possibility that the optimum temperature for the catalytic reaction will be deviated.

  When leaving the optimum temperature, the concentration of carbon monoxide in the shift gas increases, and the concentration of carbon monoxide in the product gas after the selective oxidation catalyst layer 11 increases, making it impossible to maintain a stable product gas state of the hydrogen generator. there is a possibility.

  In addition, the temperature of the combustion exhaust gas that exchanges heat with air is also separated from the reforming catalyst layer 9 that is controlled at a constant temperature, and the temperature of the air in the vicinity of the combustion exhaust gas outlet portion where the temperature has decreased to a level close to room temperature. When the temperature drops due to the influence and falls below the dew point temperature of the combustion exhaust gas, water vapor in the combustion exhaust gas is condensed and adheres to the wall surfaces of the second cylinder 20 and the first cylinder 21 as water droplets.

  When the adhering water droplets gather to some extent, they flow along the combustion exhaust gas flow path 17 to the high temperature part in the lower direction according to gravity.

  At this time, there is a possibility that the second cylinder 20 or the first cylinder 21 made of a metal material such as stainless steel may be corroded. In order to take away the heat of large evaporation latent heat from the surroundings, a local temperature drop is generated, which affects the reactivity of the catalyst and the evaporation performance of the water evaporation unit 8, and the hydrogen generator may not function.

  For this reason, the air flow path 2 and the flue gas flow path 17 are configured so as not to exchange heat excessively. At the same time, preheating of the air is also inhibited, and the energy of the flue gas is effectively recovered. There is a problem that the energy efficiency of the hydrogen generator itself cannot be reduced.

  Therefore, in the present invention, the air flow path 2 has a higher temperature than the shift catalyst layer 10 and the selective oxidation catalyst layer 11, which is less affected by the temperature change of the air supplied from the air fan 3, which varies depending on the temperature of the outside air. The heat transfer promotion wall 22 and the guide part 23 are installed at the position of.

  By configuring in this way, the air supplied to the burner 4 is guided to flow along the first cylinder 21 in contact with the combustion exhaust gas flow channel 17 and at the same time the flow velocity is increased, thereby the air flow channel. 2 and the combustion exhaust gas flow path 17 can be promoted, and the thermal energy of the combustion exhaust gas can be effectively recovered. As a result, the energy efficiency of the hydrogen generator can be improved.

  In addition, the shape of the heat transfer promotion wall 22 and the induction | guidance | derivation part 23 should just be a shape which can guide | invade air to the 1st cylinder 21 wall vicinity.

  For example, the upstream end portion of the air flow path 2 in the heat transfer promotion wall 22 shown in FIG. 1 is fixed to the fuel gas supply pipe 19 by the guide portion 23 and the downstream end portion of the air flow path 2 in the heat transfer promotion wall 22 is also fuel. The shape fixed to the gas supply pipe 19 may be a shape in which only the upstream end portion of the air flow path 2 in the heat transfer promotion wall 22 shown in FIG.

  Moreover, the shape which fixed only the downstream end part of the air flow path 2 in the heat-transfer promotion wall 22 shown in FIG.

  Moreover, it is preferable that the heat transfer promotion wall 22 and the guide portion 23 are attached to the fuel gas supply pipe 19 and maintained in their positions. This is because the configuration is simplified by integrating with the fuel gas supply pipe 19, and the burner 4, the fuel gas supply pipe 19, the heat transfer promoting wall 22 and the guide portion 23 are integrated with the first cylinder 21. This is because a hydrogen generation apparatus that can be assembled by being inserted as parts configured in (1) can be assembled.

  In addition, as a structure which accelerates | stimulates the heat exchange of the air flow path 2 and the combustion exhaust gas flow path 17, as shown in FIG. 6, the structure which processed the 1st cylinder 21 partially in the shape of a wave may be sufficient.

  This is because the surface area of the first cylinder 21 is larger than the surrounding area in the wavy processed portion, heat exchange between the air flow path 2 and the flue gas flow path 17 is promoted in the wavy area, and the heat energy of the flue gas is reduced. It is because it can collect | recover effectively.

  Further, as a configuration for promoting heat exchange between the air passage 2 and the flue gas passage 17, as shown in FIGS. 7 and 8, the outer peripheral surface or inner peripheral surface of the first cylinder 21 is partially shaved. The structure may be uneven.

  This is because the surface area of the first cylinder 21 becomes larger than the surrounding area in the part where the outer peripheral surface or inner peripheral surface of the first cylinder 21 is partially cut and made uneven, and the air flow path 2 and the flue gas flow path 17 are increased. This is because heat exchange with the combustion exhaust gas is promoted, and the thermal energy of the combustion exhaust gas can be effectively recovered.

In addition, it is preferable to arrange | position the installation position of the heat-transfer promotion wall 22 and the induction | guidance | derivation part 23 in the downstream of the air flow path 2 rather than the shift catalyst layer 10 and the selective oxidation catalyst layer 11 vicinity. This is because the arrangement avoiding the downstream side of the combustion exhaust gas flow path 17 avoids the temperature of the combustion exhaust gas from excessively decreasing near the exhaust port 13 and the unstable operation of the apparatus due to condensation. This is because hydrogen can be generated stably.

  If the heat transfer promotion wall 22 and the induction portion 23 are installed at a heat balance in which the temperature distribution of the selective oxidation catalyst layer 11 is maintained in an optimum range for the reaction, as shown in FIG. The position including the vicinity of the shift catalyst layer 10 may be provided on the downstream side of the air flow path 2 from the vicinity of the layer 11.

  This is because the influence of the temperature change of the air supplied from the air fan 3 is large in the selective oxidation catalyst layer 11 close to the air inlet, but the heat transfer promotion wall 22 and the induction portion 23 are closer to the selective oxidation catalyst layer 11 than in the vicinity. However, when the temperature of the air supplied from the air fan 3 fluctuates due to fluctuations in the outside air temperature, the temperature of the selective oxidation catalyst layer 11 falls within the optimum temperature range by being arranged on the downstream side of the air flow path 2. This is because hydrogen can be stably generated.

  In addition, it is preferable that the installation position of the heat transfer promotion wall 22 and the guide portion 23 is arranged at a position upstream of the air flow path 2 from the vicinity of the reforming catalyst layer 9.

  This is because the amount of heat exchange between the air passage 2 and the combustion exhaust gas passage 17 can be reduced in the vicinity of the reforming catalyst layer 9, thereby reducing the temperature of the combustion exhaust gas near the reforming catalyst layer 9. As a result, the heating of the reforming catalyst layer 9 is prevented from being hindered, and hydrogen can be generated efficiently.

  If the heat transfer promoting wall 22 and the guide portion 23 are installed at a heat balance in which the temperature distribution of the selective oxidation catalyst layer 11 is maintained in an optimum range for the reaction, as shown in FIG. It may be located downstream of the air flow path 2 relative to the vicinity of the layer 11 and upstream of the air flow path 2 relative to the vicinity of the shift catalyst layer 10.

  This is because the heat transfer promotion wall 22 and the induction portion 23 are arranged at positions avoiding the selective oxidation catalyst layer 11 and the shift catalyst layer 10, so that the temperature of the air supplied from the air fan 3 due to fluctuations in the outside air temperature. Even when fluctuates, the temperatures of the selective oxidation catalyst layer 11 and the shift catalyst layer 10 are maintained in the optimum temperature range, and hydrogen can be generated stably.

  Further, the modified gas flowing into the selective oxidation catalyst layer 11 is cooled by heat exchange with the air supplied from the air fan 3 via the first cylinder 21, the second cylinder 20 and the third cylinder 25. The local temperature rise of the selective oxidation catalyst layer 11 due to the selective oxidation reaction between the air supplied from the selective oxidation air supply unit 15 and the modified gas is mitigated, and the selective oxidation catalyst is prevented from deteriorating due to a high temperature, This is because hydrogen can be generated stably.

(Embodiment 2)
FIG. 9 is a schematic cross-sectional view of a hydrogen generator according to Embodiment 2 of the present invention.

  The difference from the configuration of the first embodiment is that the heat transfer promotion wall 22 and the induction portion 23 are not provided, and the air flow path 2 inside the first cylinder 21 is on the lower temperature side above the shift catalyst layer 10. The cylindrical heat insulating material 5 which is a heat insulation suppression part is installed in the position, and the air from the air fan 3 is configured to flow inside the heat insulating material 5.

  The temperature of the shift catalyst layer 10 and the selective oxidation catalyst layer 11 is determined by the water evaporation unit 8 that is heat balanced by heat exchange with the combustion exhaust gas, and the temperature of the combustion exhaust gas flowing through the combustion exhaust gas channel 17 flows through the air channel 2. It is determined by heat exchange performed through air and the heat insulating material 5.

  Here, the combustion exhaust gas and the air supplied from the air fan 3 fluctuate depending on the outside air temperature. As a result, the temperatures of the shift catalyst layer 10 and the selective oxidation catalyst layer 11 are affected by the temperature change of the air. The catalyst layer 10 and the selective oxidation catalyst layer 11 are preferably configured so as not to excessively exchange heat with the combustion exhaust gas and the air supplied from the air fan 3, but at this time, the remaining heat of the air is also inhibited at the same time. Thus, there is a problem that the energy of the combustion exhaust gas cannot be effectively recovered and the energy efficiency of the hydrogen generator itself is lowered.

  Therefore, in the present embodiment, the heat insulating material 5 that is a heat transfer suppressing portion is arranged in a region including the vicinity of the shift catalyst layer 10 and the selective oxidation catalyst layer 11 in a part of the inner surface of the first cylinder 21. .

  With this configuration, even when the temperature of the air supplied from the air fan 3 fluctuates due to fluctuations in the outside air temperature, the temperatures of the selective oxidation catalyst layer 11 and the shift catalyst layer 10 are kept in the optimum temperature range. , Can stably generate hydrogen.

  At the same time, heat exchange between the combustion exhaust gas flowing through the combustion exhaust gas flow channel 17 and the air flowing through the air flow channel 2 is efficient in a region of the air flow channel 2 away from the vicinity of the shift catalyst layer 10 and the selective oxidation catalyst layer 11. As a result, the energy of the combustion exhaust gas can be effectively recovered by preheating the air, and as a result, the energy efficiency of the hydrogen generator can be improved.

  The heat insulating material 5 installed in the first cylinder 21 only needs to suppress heat exchange between the combustion exhaust gas channel 17 and the air channel 2, and not only the inner surface of the first cylinder 21, It may be installed on the outside.

  The heat insulating material 5 installed in the air flow path 2 may be anything as long as it is configured to suppress heat transfer between the air flow path 2 and the combustion exhaust gas flow path 17, and for example, a heat shield plate 24 as shown in FIG. It may be. This is because the heat shield plate 24 forms a stagnation region that does not flow, and the stagnation region suppresses heat exchange between the air passage 2 and the combustion exhaust gas passage 17.

(Embodiment 3)
FIG. 11 is a schematic cross-sectional view of a hydrogen generator according to Embodiment 3 of the present invention.

  As shown in FIG. 11, the hydrogen generator of the present embodiment is composed of a plurality of flat plate-shaped containers, and has at least a reforming section container 44 and a combustion container 43. The reforming catalyst layer 9, the shift catalyst layer 10, and the selective oxidation catalyst layer 11 are provided inside the container, and the combustion container 43 includes the burner 4, the heat insulating material 5, and the fuel gas supply pipe 19 inside the container. Yes.

  Further details of the basic configuration and gas flow of the hydrogen generator of the present embodiment will be described.

  The hydrogen generator of the present embodiment includes a water evaporation unit 8 that evaporates the water supplied from the water supply unit 7 and preheats the mixed gas of the source gas and water vapor supplied from the source gas supply unit 6.

  In addition, the reforming catalyst layer 9 that promotes the reforming reaction between the raw material gas and the steam, and the carbon monoxide in the reformed gas generated in the reforming catalyst layer 9 and the steam are subjected to a modification reaction, thereby the reformed gas. The shift catalyst layer 10 for reducing the carbon monoxide concentration is provided.

Further, the carbon monoxide remaining in the hydrogen-containing gas after passing through the shift catalyst layer 10 is used using air supplied from the selective oxidation air supply unit 15 to the hydrogen-containing gas after passing through the shift catalyst layer 10. The selective oxidation catalyst layer 11 is mainly oxidized and removed.

  The shift catalyst layer 10 and the selective oxidation catalyst layer 11 constitute a carbon monoxide reduction unit.

  The reforming catalyst layer 9 is provided with a Ru-based reforming catalyst having a spherical catalyst having a diameter of about 3 mm. The shift catalyst layer 10 is provided with a Cu—Zn shift catalyst having a cylindrical shape with a diameter of about 3 mm and a height of 3 mm. The selective oxidation catalyst layer 11 is provided with a Ru-based selective oxidation catalyst having a spherical shape with a diameter of about 3 mm.

  Further, in order to supply reaction heat necessary for the reforming reaction in the reforming catalyst layer 9, the combustion container 43 has a burner 4 that burns combustion gas and serves as a heating source, and the burner 4 includes an air fan. Fuel air is supplied from 3, and fuel is supplied from the fuel gas supply unit 1.

  And the hydrogen containing gas produced | generated by the hydrogen production | generation apparatus which has the said structure is supplied to the fuel cell (not shown) etc. installed outside from the production gas exit 12, and is used for the electric power generation of a fuel cell.

  Further, the combustion exhaust gas generated by the burner 4 is guided to the combustion exhaust gas passage 17, and the heat of the combustion exhaust gas is transferred to the reforming catalyst layer 9 and the water evaporation unit 8, and the reforming unit container 44 and the combustion container 43 are heated. Supplied through the second wall 40, which is the wall surface in contact. The combustion exhaust gas is exhausted from the exhaust port at the lower part of the combustion container 43 to the outside of the hydrogen generator.

  Here, the temperature of the reforming catalyst layer 9 is the same as that of the combustion exhaust gas flowing from the burner 4 through the combustion exhaust gas passage 17 and the reforming catalyst layer 9 that flows adjacent to the reforming catalyst layer 9 and exits the reforming catalyst layer 9. The reformed gas temperature sensor 14 detects the temperature of the reformed gas exiting the reforming catalyst layer 9 and controls the temperature of the reformed gas exiting from the reforming catalyst layer 9. Therefore, if the reformed gas temperature sensor 14 is controlled to a constant temperature, the temperature of the entire reforming catalyst layer 9 can be maintained at a stable temperature.

  On the other hand, the shift catalyst layer 10 and the selective oxidation catalyst layer 11 are surrounded by a high-performance heat insulating material 18, and the hydrogen generator covered with the heat insulating material 18 is disposed in the casing of the system. The temperature of the shift catalyst layer 10 and the selective oxidation catalyst layer 11 is determined by the water evaporation section 8 that is thermally balanced by heat exchange with the combustion exhaust gas.

  Here, since the burner 4 is located in the vicinity of the upstream portion of the reforming catalyst layer 9, the reforming portion container 44 of the combustion exhaust gas channel 17 adjacent to the water evaporation portion 8 located below the reforming catalyst layer 9. The air flow path 2 to be supplied to the burner 4 is located at a position on the opposite side.

  Here, the air flowing through the air flow path 2 exchanges heat with the combustion exhaust gas flowing through the combustion exhaust gas flow path 17 so that the air can be preheated.

  Since the amount of heat used for preheating the air is reused for heating the reforming catalyst via the combustion exhaust gas, the combustion exhaust gas flow path 17 is maintained while maintaining the reforming catalyst in an appropriate temperature distribution. Thus, the energy of the combustion exhaust gas discharged from the vicinity of the reforming catalyst layer 9 can be effectively recovered, and the energy efficiency of the hydrogen generator itself can be improved.

Here, the combustion exhaust gas and the air supplied from the air fan 3 fluctuate depending on the outside air temperature. As a result, the temperatures of the shift catalyst layer 10 and the selective oxidation catalyst layer 11 are affected by the temperature change of the air. The temperature of the catalyst layer 10 and the selective oxidation catalyst layer 11 is preferably configured so that heat exchange between the exhaust gas and the air supplied from the air fan 3 is not performed excessively. There is also a problem that the energy of the combustion exhaust gas cannot be effectively recovered and the energy efficiency of the hydrogen generator itself is lowered.

  Therefore, in the present embodiment, in a part of the surface of the first wall 41 facing the air flow path 2, the region including the vicinity of the shift catalyst layer 10 and the selective oxidation catalyst layer 11, the heat transfer suppression unit A certain heat insulating material 5 is arranged.

  With this configuration, even when the temperature of the air supplied from the air fan 3 fluctuates due to fluctuations in the outside air temperature, the temperatures of the selective oxidation catalyst layer 11 and the shift catalyst layer 10 are kept in the optimum temperature range. , Can stably generate hydrogen.

  At the same time, heat exchange between the combustion exhaust gas flowing through the combustion exhaust gas flow channel 17 and the air flowing through the air flow channel 2 is efficient in a region of the air flow channel 2 away from the vicinity of the shift catalyst layer 10 and the selective oxidation catalyst layer 11. As a result, the energy of the combustion exhaust gas can be effectively recovered by preheating the air, and as a result, the energy efficiency of the hydrogen generator can be improved.

(Embodiment 4)
Next, the fuel cell system in Embodiment 4 of this invention is demonstrated using FIG. FIG. 12 is a block diagram showing an example of the fuel cell system in the fourth embodiment.

  As shown in FIG. 12, a fuel cell system 500 according to Embodiment 4 includes a hydrogen generator 100 and a fuel cell 400 that generates power using a hydrogen-containing gas supplied from the hydrogen generator 100.

  The hydrogen generator 100 is any one of the hydrogen generators described in the first to third embodiments so far. The fuel cell 400 may be any fuel cell such as a solid polymer fuel cell and a solid oxide fuel cell as long as it is a fuel cell that generates power using a hydrogen-containing gas.

  As described above, it is possible to obtain a fuel cell system that is small and highly efficient and can generate power stably.

  The hydrogen generator of the present invention is a high-concentration hydrogen-containing gas in which carbon monoxide is reduced to an extremely low concentration without reducing the energy efficiency of the hydrogen generator even under conditions in which the outside air temperature at the installation of the device greatly changes. For example, it is useful as an apparatus for supplying a product gas containing hydrogen to a domestic fuel cell system.

DESCRIPTION OF SYMBOLS 1 Fuel gas supply part 2 Air flow path 3 Air fan 4 Burner 5 Heat insulating material 6 Raw material gas supply part 7 Water supply part 8 Water evaporation part 9 Reforming catalyst layer 10 Shifting catalyst layer 11 Selective oxidation catalyst layer 12 Product gas outlet 13 Exhaust gas Port 14 Reformed gas temperature sensor 15 Selective oxidized air supply unit 17 Combustion exhaust gas flow path 18 Heat insulating material 19 Fuel gas supply pipe 20 Second cylinder 21 First cylinder 22 Heat transfer promoting wall 23 Inducting part 24 Heat shield plate 25 First Three cylinders 40 Second wall 41 First wall 43 Combustion vessel 44 Reformer vessel 100 Hydrogen generator 400 Fuel cell 500 Fuel cell system

Claims (19)

A reforming catalyst layer that is supplied with raw material gas and steam to generate reformed gas by a steam reforming reaction;
A carbon monoxide removal layer for removing carbon monoxide contained in the reformed gas;
A burner which is supplied with fuel gas and combustion air and emits combustion exhaust gas;
A first wall that separates the combustion air flow path and the combustion exhaust gas flow path so that heat exchange can be performed between the combustion exhaust gas flowing in a direction opposite to the flow direction of the combustion air and the combustion air. When,
First, the flow path of the combustion exhaust gas and the flow path of the raw material gas and the water vapor are partitioned so that heat exchange is possible between the raw material gas and the water vapor flowing in a direction opposite to the flow direction of the combustion exhaust gas and the combustion exhaust gas. Two walls,
The flow path of the source gas and the steam and the flow of the reformed gas so that the reformed gas flowing in the direction opposite to the flow direction of the source gas and the steam can exchange heat with the source gas and the steam. A third wall that partitions the road,
The reforming catalyst layer is provided on the downstream side of the flow path of the raw material gas and the water vapor so that heat exchange with the combustion exhaust gas is possible,
The carbon monoxide removal layer was provided on the downstream side of the flow path of the reformed gas so that heat exchange with the raw material gas and the water vapor was possible.
A hydrogen generator,
In the periphery of the portion of the third wall facing the carbon monoxide removal layer, heat exchange performance with the combustion air via the first wall and the second wall is the third wall. The wall is configured to have a portion that is higher than the heat exchange performance between the portion facing the carbon monoxide removal layer and the combustion air through the first wall and the second wall. Was
Hydrogen generator. A heat transfer promoting part for promoting heat transfer from the combustion air flow path to the combustion exhaust gas flow path via the first wall is provided in the first wall, the first wall in the third wall. Provided avoiding the area including the part facing the carbon oxide removal layer and the part that is most easily heat exchanged,
The hydrogen generator according to claim 1. In the first wall, the heat transfer facilitating portion is more flowable than the portion of the third wall that is most easily exchanged with the portion of the third wall facing the carbon monoxide removal layer. Provided upstream or downstream of
The hydrogen generator according to claim 2. The heat transfer promotion part includes a heat transfer promotion wall provided close to a surface of the first wall that contacts the combustion air, the first wall, and the heat transfer promotion wall. Including a guiding part that guides to the gap of
The hydrogen generator according to claim 2 or 3. The heat transfer promotion wall is attached to a fuel gas supply pipe that supplies the fuel gas to the burner via the guide portion.
The hydrogen generator according to claim 4. The heat transfer promoting part widens the surface area of at least one of the surface in contact with the combustion air or the surface in contact with the combustion exhaust gas in the first wall.
The hydrogen generator according to claim 2 or 3. The heat transfer promoting part is provided on the downstream side of the combustion air from the carbon monoxide removal layer,
The hydrogen generator according to any one of claims 2 to 6. The carbon monoxide removal layer includes a shift catalyst layer that reduces carbon monoxide by a shift reaction,
The heat transfer promoting part is provided on the downstream side of the combustion air from the shift catalyst layer,
The hydrogen generator according to any one of claims 2 to 6. The carbon monoxide removal layer includes a selective oxidation catalyst layer that removes carbon monoxide by mixing an oxidant containing oxygen in the reformed gas,
The heat transfer promoting part is provided on the downstream side of the combustion air with respect to the selective oxidation catalyst layer,
The hydrogen generator according to any one of claims 2 to 6. The heat transfer promotion part is provided on the upstream side of the combustion air with respect to the reforming catalyst layer.
The hydrogen generator according to any one of claims 7 to 9. The carbon monoxide removal layer includes a shift catalyst layer that reduces carbon monoxide by a shift reaction, and a selective oxidation catalyst layer that removes carbon monoxide by mixing an oxidant containing oxygen in the shift gas from the shift catalyst layer. And is divided into
The heat transfer promoting part is provided on the upstream side of the combustion air with respect to the shift catalyst layer and on the downstream side of the combustion air with respect to the selective oxidation catalyst layer.
The hydrogen generator according to any one of claims 2 to 6. A heat transfer suppression unit configured to suppress heat transfer from the combustion air flow path to the combustion exhaust gas flow path via the first wall in the first wall; Provided in a region including a portion that is most easily heat exchanged with a portion facing the carbon oxide removal layer,
The hydrogen generator according to claim 1. The region where the heat transfer suppression portion is provided is a region where the combustion air is more in the first wall than the portion in the third wall that is most easily heat exchanged with the portion facing the carbon monoxide removal layer. Including the area upstream of the flow path,
The hydrogen generator according to claim 12. The heat transfer suppression portion is provided on the surface side of the first wall facing the combustion air passage.
The hydrogen generator according to claim 12 or 13. The heat transfer suppression part is a heat insulating material provided on a surface of the first wall facing the combustion air passage.
The hydrogen generator according to claim 14. The heat transfer suppression unit is a heat shield plate that forms a heat insulating layer of air between a surface of the first wall facing the combustion air passage.
The hydrogen generator according to claim 14. The burner is disposed in the innermost portion, the first wall is disposed outside the burner, the second wall is disposed outside the first wall, and the second wall is disposed outside the second wall. 3 walls were placed,
The hydrogen generator according to any one of claims 1 to 16. The first wall, the second wall, and the third wall are arranged concentrically around the burner.
The hydrogen generator according to claim 17.   A fuel cell system comprising: the hydrogen generator according to any one of claims 1 to 18; and a fuel cell that generates electric power using an oxidizing gas containing oxygen and a product gas supplied from the hydrogen generator.

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