JP2006056722A - Fuel reformer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology for suppressing uneven supply of a fluid from a fluid passage having bent parts in a fuel reformer for producing hydrogen from a fuel to be reformed. <P>SOLUTION: The invention is for a fuel reformer which produces hydrogen from a fuel to be reformed. The fuel reformer is provided with a reaction part, and the fluid passage which is for supplying a fluid and has bent parts to bend the advancing direction of the fluid. The bent parts are characterised by being provided with flow velocity dispersion suppressing parts for suppressing the dispersion of the flow velocity of components in the fluid supply direction. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fuel reformer that generates hydrogen from a reformed fuel containing a hydrocarbon-based compound.

  Conventionally, a fuel reformer has been proposed as a fuel gas supply source of a fuel cell. The fuel reformer is desired to be miniaturized due to the mounting of the fuel cell system on the vehicle and other reasons. Miniaturization of the fuel reformer can also be realized by providing a bent portion in a part of the fluid passage of the fuel reformer.

JP 2003-261303 A

  However, if a bent portion is provided in the fluid passage of the fuel reformer, for example, it is expected that the supply of fluid to the reforming reaction portion becomes non-uniform. This is because the bent portion generates a turbulent flow having a velocity vector in the traveling direction of the fluid. Such non-uniform fluid supply to the reforming reaction section may cause non-uniform reaction temperature in the reforming reaction section and other adverse effects on the reforming reaction. Further, such a non-uniform fluid supply may adversely affect not only the reforming reaction but also the shift reaction and other reactions.

  The present invention has been made to solve the above-described problem, and in a fuel reformer that generates hydrogen from reformed fuel, it suppresses uneven supply of fluid from a fluid passage having a bent portion. The purpose is to provide technology.

The present invention is a fuel reformer for generating hydrogen from reformed fuel,
A reaction part;
A fluid passage having a bent portion for supplying a fluid to the reaction portion and bending a traveling direction of the fluid;
With
The bending portion includes a flow velocity dispersion suppressing portion that suppresses dispersion of the flow velocity of the fluid supply direction component.

  In the fuel reformer of the present invention, since the dispersion (variation) of the flow velocity of the fluid supply direction component is suppressed, the fluid supplied from the bent portion can be uniformly supplied to the reaction portion. Thereby, miniaturization of the fuel reformer can be realized while suppressing variation in chemical reaction in the reaction section.

  Here, the “reaction part” includes components that cause a reforming reaction, a shift reaction, and other chemical reactions. Moreover, suppression of dispersion | distribution of the flow velocity of the fluid supply direction component can be implement | achieved by various techniques, such as stirring of the fluid in a bending part and boundary layer control. These techniques will be described later.

  In the fuel reformer, the flow velocity dispersion suppressing unit may include a stirring unit that stirs the fluid in the bent portion. By so doing, it is possible to make uniform the variation in the fluid temperature in the fluid passage.

  In the fuel reformer, the agitation unit may include a fluid swirl unit configured to swirl the fluid around an axis in a traveling direction of the fluid passage.

  In this way, if the fluid is swirled around the axis of the fluid passage in the traveling direction, the velocity vector in the traveling direction of the fluid passage is not excessively formed while the fluid is agitated. It is possible to efficiently achieve uniform speed.

In the fuel reformer, the agitating unit is configured to swirl the fluid around an axis in a traveling direction of the fluid passage, and a first fluid swirling unit on the upstream side and a second fluid on the downstream side. A swivel unit;
The first fluid swirling unit and the second fluid swirling unit may be configured to swirl the fluid in opposite directions with respect to the axis of the fluid passage.

  Thus, if the swirl of the fluid formed around the axis of the fluid passage is reversed, the speed of the fluid passage in the direction of travel can be made more uniform.

In the fuel reformer, the agitating unit is configured to swirl the fluid around an axis in a traveling direction of the fluid passage, and a first fluid swirling unit on the upstream side and a second fluid on the downstream side. A swivel unit;
The first fluid swirl unit and the second fluid swirl unit may be configured to swirl the fluid in the same direction with respect to the axis of the fluid passage in the traveling direction.

  Thus, if the fluid formed around the axis of the fluid passage is swung in the same direction, the speed in the direction of travel can be made uniform without excessively increasing the flow resistance of the fluid passage. Can do.

  In the fuel reformer, the fluid passage may receive the fluid from a heat exchange unit that performs heat exchange of the fluid. In this way, the temperature gradient in the fluid generated by heat exchange can be reduced, and the effects of the present invention can be significantly achieved.

  In the fuel reformer, the reaction unit may perform a reforming reaction that reforms the reformed fuel into a reformed gas. In this case, since the homogenization of the reaction is particularly important in the reforming reaction, the effect of the present invention can be remarkably exhibited if the fluid supply rate to the reforming reaction is uniformized.

  The present invention can be realized in various other modes such as a fuel cell system including a fuel reforming device, a moving body equipped with a fuel cell system including a fuel reforming device, and the like.

Hereinafter, embodiments of the present invention will be described in the following order based on examples.
A. Schematic configuration of a fuel cell system in an embodiment of the present invention:
B. Hardware configuration of a fuel reformer in an embodiment of the present invention:
C. Variations:

A. Schematic configuration of the fuel cell system 10:
FIG. 1 is an explanatory diagram showing a schematic configuration of a fuel cell system 10 according to an embodiment of the present invention. The fuel cell system 10 includes a fuel cell 100, a fuel reformer 200, an oxidizing gas supply unit 300, and a control unit 600 for controlling the operation of the entire fuel cell system. The fuel cell 100 generates power using the fuel gas supplied from the fuel reformer 200 and the oxidizing gas supplied from the oxidizing gas supply unit 300. The fuel reformer 200 reforms the raw fuel and supplies fuel gas containing hydrogen gas to the fuel cell 100. The oxidizing gas supply unit 300 supplies an oxidizing gas (air) containing oxygen gas to the fuel cell 100 using the blower 310.

  The fuel reformer 200 includes a premixed fuel tank 210, a blower 220, a vaporizer 230, a reformer 240, a first heat exchange unit 250, a shift unit 260, a hydrogen separator 270, 2 heat exchange part 280 and purification part 290 are provided.

  The premixed fuel tank 210 is a tank that stores a premixed fuel in which a hydrocarbon-based raw fuel and water are mixed in advance. The premixed fuel is supplied to the vaporizer 230 using the pump 212 and the injection valve 214. The blower 220 supplies air to the vaporization unit 230 via the first heat exchange unit 250. The reason why the air is supplied via the first heat exchange unit 250 is to supply heated air to the vaporization unit 230.

  The vaporizing unit 230 vaporizes the premixed fuel injected by the injection valve 214 using the heating unit 232. As a result, a mixed gas of raw fuel, water vapor, and air is generated and supplied to the reforming unit 240.

  The reforming unit 240 reforms the raw fuel contained in the mixed gas into a reformed gas containing hydrogen gas and carbon monoxide gas using water vapor and oxygen gas in the air. This reforming reaction is performed using a reforming catalyst (not shown).

  The first heat exchange unit 250 cools the reformed gas supplied from the reforming unit 240 and supplies it to the shift unit 260. The reformed gas is cooled because the reaction temperature in the shift unit 260 is lower than the reaction temperature in the reforming unit 240.

  The shift unit 260 converts the carbon monoxide gas in the reformed gas into hydrogen gas and carbon dioxide gas to reduce the carbon monoxide gas concentration in the reformed gas. The reason why the concentration of carbon monoxide gas in the reformed gas is lowered is to suppress poisoning of the noble metal catalyst supported on the electrode inside the fuel cell 100. The shift reaction is performed using a shift catalyst (not shown).

  The hydrogen separation unit 270 extracts hydrogen gas from the gas supplied from the shift unit 260 and supplies it to the second heat exchange unit 280. The gas supplied from the shift unit 260 is put into the supply chamber 272 of the hydrogen separation unit 270. Since the supply chamber 272 faces the extraction chamber 274 through a hydrogen permeable membrane 270f that selectively permeates hydrogen gas, only the hydrogen gas is supplied to the extraction chamber 274. The hydrogen gas supplied to the extraction chamber 274 is supplied to the fuel cell 100 via the second heat exchange unit 280 by the oxidation off gas supplied from the fuel cell 100. On the other hand, the residual gas that has not permeated through the hydrogen permeable membrane 270 f is sent to the purification unit 290.

  The purification unit 290 converts the carbon monoxide gas discharged without being converted in the shift unit 260 into harmless carbon dioxide gas using oxygen gas in the air and discharges it to the atmosphere.

  Thus, the fuel reformer 200 generates fuel gas by performing chemical reactions in a plurality of stages. The components that perform chemical reactions in the plurality of stages are connected by a plurality of fluid passages having curved portions as described later.

B. Hardware configuration of a fuel reformer in an embodiment of the present invention:
FIG. 2 is a layout diagram showing a hardware configuration of the fuel reformer 200 according to the embodiment of the present invention. This layout diagram shows the arrangement of each component of the fuel reformer 200 in the schematic configuration diagram (FIG. 1) of the fuel cell system 10.

  Each component of the fuel reformer 200 is compactly arranged using two U-shaped fluid passages 110 and 120. Specifically, between the vaporization unit 230 and the reforming unit 240 and between the first heat exchange unit 250 and the shift unit 260, a U-shaped fluid passage 110 and a U-shaped fluid passage 120, respectively. It is connected.

  FIG. 3 is an explanatory diagram showing how the fluid flows inside the U-shaped fluid passage 110a when the present invention is not applied. As can be seen from FIG. 3, the fluid supplied from the vaporization unit 230 is separated from the inner wall of the fluid passage to generate a turbulent flow (vortex). Since this turbulent flow has a velocity vector in the fluid traveling direction, the supply of fluid to the reforming unit 240 becomes non-uniform. That is, a portion where the fluid flow rate is fast and a portion where the fluid is flowed are generated at the entrance to the reforming unit 240, and a portion where a large amount of fluid is supplied and a portion where a small amount of fluid is supplied are generated.

  If the supply of fluid to the reforming unit 240 becomes non-uniform, the amount of reforming reaction also becomes non-uniform. As a result, the heat generated by the reforming reaction also becomes non-uniform, and a thermal gradient is generated in the reforming unit 240. Such a thermal gradient makes it difficult to control the reaction temperature in the reforming unit 240, and thus becomes a factor that hinders an appropriate reforming reaction. Furthermore, such a thermal gradient may adversely affect not only the reforming reaction but also the shift reaction and other chemical reactions.

  FIG. 4 is an explanatory diagram showing the internal configuration of the U-shaped fluid passage 110 in the embodiment of the present invention. The fluid passage 110 is connected to the upstream outer pipe 111u, the upstream inner pipe 112u, the downstream outer pipe 111d, the downstream inner pipe 112d, the connecting pipe 118 connecting them, and the upstream outer pipe 111u. An upstream throttle plate 116u provided between the pipe 118, a downstream throttle plate 116d provided between the downstream outer pipe 111d and the connecting pipe 118, and an upstream swivel provided on the upstream inner pipe 112u. The blade group 114u and the downstream swirl blade group 114d provided in the downstream inner pipe 112d are provided. The internal configuration of the U-shaped fluid passage 120 is the same as that of the U-shaped fluid passage 110.

  In the U-shaped fluid passage 110, the fluid flows as follows. The fluid supplied from the vaporization unit 230 first flows into the upstream inner pipe 112u. This fluid flows into the upstream outer pipe 111u while swirling through the gap between the upstream swirl blade groups 114u mounted on the upstream inner pipe 112u. Since this swirling flow has a velocity vector in a direction perpendicular to the central axis of the fluid passage 110, the fluid can be stirred in a direction perpendicular to the central axis of the fluid passage 110. This agitation can produce an effect of reducing the velocity gradient (or dispersion) in the direction of the central axis of the fluid passage 110 in the direction perpendicular to the central axis of the fluid passage 110.

  The fluid stirred in this manner passes through the upstream throttle formed by the upstream throttle plate 116u and is supplied to the connecting pipe 118. This restriction can produce an effect of further reducing the velocity gradient in the central axis direction of the fluid passage 110. The fluid that has passed through the connecting pipe 118 passes through the downstream throttle formed by the downstream throttle plate 116d and flows into the downstream outer pipe 111d. The fluid is supplied to the reforming unit 240 via the inside of the downstream inner pipe 112d while swirling through the gap between the downstream swirl blade groups 114d provided in the downstream inner pipe 112d.

  As described above, in this embodiment, by stirring the fluid that is the mixed gas, variations in the concentration distribution and fluid temperature in the fluid passage, and further, variations in the flow velocity in the central axis direction of the fluid passage 110 are suppressed. become. In this way, since the concentration distribution, temperature distribution, and supply amount of the fluid that is the mixed gas are supplied to the reforming unit 240 in a state of being uniformized in the fluid passage, a homogeneous chemical reaction in the reforming unit 240 is realized. can do.

  In this embodiment, the downstream inner pipe 112d including the downstream swirl blade group 114d, the upstream inner pipe 112u including the upstream swirl blade group 114u, and the two throttle plates 116u and 116d are claimed. This corresponds to the “flow velocity dispersion suppression unit”.

  In addition, the swirl direction may be configured such that the upstream swirl blade group 114u and the downstream swirl blade group 114d are swung in the same direction with respect to the axis of the fluid passage. May be. However, if it is configured to rotate in the same direction, there is an advantage that the flow path resistance of the fluid passage can be reduced, and if it is configured to be reversed, the speed in the traveling direction of the fluid passage can be made more uniform. There is an advantage that can be.

C. Variations:
As mentioned above, although several embodiment of this invention was described, this invention is not limited to such embodiment at all, and implementation in a various aspect is possible within the range which does not deviate from the summary. It is. For example, the following modifications are possible.

C-1. In the above embodiment, both the U-shaped fluid passage 110 that supplies fluid to the reforming unit 240 and the U-shaped fluid passage 120 that supplies fluid to the shift unit 260 are equipped with flow velocity dispersion suppression units. However, for example, only the U-shaped fluid passage 110 that supplies the fluid to the reforming unit 240 may be provided with the flow velocity dispersion suppression unit. In general, the present invention only needs to be configured such that a flow velocity dispersion suppression unit is provided in at least a part of a fluid passage that supplies a fluid to a component that performs a chemical reaction such as a reforming reaction or a shift reaction.

  However, when the flow velocity dispersion suppression unit is provided only in the fluid passage that supplies the fluid to some of the reaction units, the fluid is supplied to the reforming unit 240 that performs the reforming reaction to reform the reformed fuel into the reformed gas. It is preferable to equip the fluid passage to be supplied with a flow velocity dispersion suppressing portion. This is because the homogenization of the reaction is particularly important in the reforming reaction, so that the effect of the present invention can be remarkably exhibited if the fluid supply rate to the reforming reaction is uniformized.

  In addition, since heat exchange tends to cause non-uniformity in fluid temperature, the flow rate dispersion suppressing unit is configured to be provided in a bent portion of a fluid passage that receives fluid from a heat exchange unit that performs heat exchange of fluid. It is preferable.

C-2. In the above embodiment, the flow velocity dispersion suppressing unit swirls the fluid by using the downstream inner tube 112d including the downstream swirl blade group 114d and the upstream inner tube 112u including the upstream swirl blade group 114u. As shown in FIG. 5, for example, a plurality of holes are formed in the two inner pipes 112m instead of swirling blades to stir the fluid. Also good.

C-3. In the above embodiment, the dispersion (variation) in the flow velocity of the component in the fluid supply direction is suppressed by stirring. However, for example, separation of the fluid from the inner wall of the fluid passage at the bent portion is suppressed, and the fluid from the fluid passage is prevented. You may make it suppress supply nonuniformity. Such fluid separation can be suppressed, for example, by providing a large number of small protrusions on the inner wall of the fluid passage and generating a large number of small vortices in the boundary layer of the nearby fluid (boundary layer control). Generally, the flow velocity dispersion suppressing unit used in the present invention only needs to be configured to suppress the dispersion of the flow velocity of the fluid supply direction component.

C-4. In the above embodiment, the U-shaped fluid passages 110 and 120 are used as the fluid passages having the bent portions, and the fluid traveling direction is bent by 180 degrees. However, the fluid traveling direction may be bent by 90 degrees, for example. The present invention is applicable. The present invention can be applied to a fuel reformer that uses a fluid passage having a bent portion that bends the traveling direction of fluid widely regardless of the angle.

BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing which shows schematic structure of the fuel cell system 10 in the Example of this invention. The layout figure which shows the hardware constitutions of the fuel reforming apparatus 200 in the Example of this invention. Explanatory drawing which shows a mode that a fluid flows in the inside of the U-shaped fluid channel | path 110a when this invention is not applied. Explanatory drawing which shows the internal structure of the U-shaped fluid channel | path 110 in the Example of this invention. Explanatory drawing which shows a part of internal structure of the U-shaped fluid channel | path in the modification of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Fuel cell system 100 ... Fuel cell 110, 110a ... Fluid passage 111d ... Downstream side outer tube 111u ... Upstream side outer tube 112d ... Downstream side inner tube 112u ... Upstream side inner tube 112m ... Modified inner tube 114d ... Downstream side Swirling blade group 114u ... Upstream swirl blade group 116d, 116u ... Restriction forming plate 118 ... Connecting pipe 120 ... Fluid passage 200 ... Fuel reformer 210 ... Premixed fuel tank 212 ... Pump 214 ... Injection valve 220 ... Blower 230 ... Vaporization Unit 232 ... heating unit 240 ... reforming unit 250 ... first heat exchange unit 260 ... shift unit 270 ... hydrogen separation unit 270f ... hydrogen permeable membrane 272 ... supply chamber 274 ... extraction chamber 280 ... second heat exchange unit 290 ... Purification unit 300 ... oxidizing gas supply unit 310 ... blower 600 ... control unit

Claims (7)

A fuel reformer that generates hydrogen from reformed fuel,
A reaction part;
A fluid passage having a bent portion for supplying a fluid to the reaction portion and bending a traveling direction of the fluid;
With
The fuel reforming apparatus according to claim 1, wherein the bending portion includes a flow velocity dispersion suppressing portion that suppresses dispersion of the flow velocity of the fluid supply direction component. The fuel reformer according to claim 1, wherein
The said flow velocity dispersion | distribution suppression part is a fuel reformer provided with the stirring part which stirs the said fluid in the said bending part. The fuel reformer according to claim 2, wherein
The fuel reformer, wherein the agitation unit includes a fluid swirl unit configured to swirl the fluid around an axis in a traveling direction of the fluid passage. The fuel reformer according to claim 2, wherein
The agitation unit includes an upstream first fluid swirl unit and a downstream second fluid swirl unit configured to swirl the fluid about an axis in a traveling direction of the fluid passage;
The fuel reformer is configured such that the first fluid swirl unit and the second fluid swirl unit are configured to swirl the fluid in a reverse direction with respect to an axis in a traveling direction of the fluid passage. The fuel reformer according to claim 2, wherein
The agitation unit includes an upstream first fluid swirl unit and a downstream second fluid swirl unit configured to swirl the fluid about an axis in a traveling direction of the fluid passage;
The fuel reformer is configured such that the first fluid swirling unit and the second fluid swirling unit are configured to swirl the fluid in the same direction with respect to an axis in a traveling direction of the fluid passage. A fuel reformer according to any one of claims 1 to 5,
The fluid passage is a fuel reformer that receives the fluid from a heat exchange unit that performs heat exchange of the fluid. The fuel reformer according to any one of claims 1 to 6,
The said reaction part is a fuel reformer which performs the reforming reaction which reforms the said reformed fuel into reformed gas.

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