JP4471634B2 - Fuel reformer storage container - Google Patents

Description

  The present invention relates to a fuel reformer for constituting a fuel reformer using a fuel reformer that generates hydrogen gas from a variety of fuels using a steam reforming reaction that is an endothermic catalytic reaction, for example, in a fuel cell system The present invention relates to a storage container and a fuel reformer.

  In recent years, fuel cell systems have been in the limelight as next-generation power systems that produce electric energy efficiently and cleanly. In the cogeneration power generation system market, which is already represented by the automobile market and household fuel cell power generation systems. In the field, field tests for practical application aiming at low cost are actively conducted.

  More recently, the fuel cell system has been reduced in size and is being studied for use as a power source for portable devices such as mobile phones, PDAs (Personal Digital Assistants), notebook computers, digital video cameras, and digital still cameras.

  In general, a fuel cell uses, for example, a hydrocarbon gas such as methane or natural gas (CNG) or an alcohol such as methanol or ethanol as a fuel. A fuel reformer using a fuel reformer uses a steam reforming reaction to generate hydrogen gas and After reforming to other gas, power is generated by supplying this hydrogen gas to a power generation device called a power generation cell.

  The reforming of the fuel by the fuel reformer here refers to a process in which reformable fuel is combined with water vapor to generate hydrogen gas by a catalytic reaction.

For example, when methanol is used as a fuel, a steam reforming reaction as shown in the following chemical reaction formula (1) (in formula (1), steam is combined with methanol to form hydrogen and carbon dioxide. This refers to a process of generating hydrogen gas (H ₂ ) by a reforming reaction). Note that a very small amount of product gas (mainly CO ₂ ) other than hydrogen produced by this reforming reaction is usually discharged into the atmosphere.

CH ₃ OH + H ₂ O → 3H ₂ + CO ₂ (1)
Further, since such a steam reforming reaction is an endothermic reaction, it is necessary to maintain the reaction temperature by heating from the outside with a heater or the like. Therefore, in order to reform the fuel in the fuel reformer, for example, methanol was used as the fuel in order to prevent the steam reforming activity of the catalyst from being lowered and to maintain a high concentration of generated hydrogen gas. In some cases, a temperature of about 200 to 500 ° C. is required, and in the case of using methane gas, a high temperature of about 300 to 800 ° C. is required.

Therefore, in a cogeneration power generation system typified by a household fuel cell system, since this system itself is large, the outer wall of the fuel reformer storage container is made into a double structure to form a vacuum container, or 2 By filling a heat insulating material between the inner and outer walls having a heavy structure, the heat inside the fuel reformer is prevented from being conducted to the outside and the temperature of the fuel reformer is lowered. Therefore, when storing the fuel reformer in the fuel reformer storage container, the fuel reformer can be directly mounted and fixed on the inner wall of the double structure of the fuel reformer storage container. It is.
JP 2003-2602 A

  However, fuel cell systems for portable devices are required to be reduced in size and height to be housed in portable devices. On the other hand, the conventional structure of the outer wall of the fuel reformer storage container having a double structure cannot be employed in a fuel cell system for portable devices because the entire fuel cell system becomes complicated and large. . In addition, when the fuel reformer is directly mounted and fixed to the inner wall of the double structure of the fuel reformer storage container, the heat of the fuel reformer is stored in the fuel reformer from the bonded portion. Conducts directly to the container. As a result, the temperature of the surface of the fuel reformer storage container rises, and there is a risk that other parts in the portable device may be destroyed by the heat, or the user of the portable device may be burned.

  Further, since the steam reforming reaction as shown in the chemical reaction formula (1) is an endothermic reaction, in order to reform the fuel with the fuel reformer, the fuel reformer is heated with a heater or the like. It is necessary to maintain the reaction temperature at a constant temperature. However, the heat generated in the fuel reformer is conducted to the fuel reformer storage container, so that the temperature of the fuel reformer decreases. Therefore, in order to maintain the reaction temperature, it is necessary to increase the heating value of the heater. Increasing the heating value of the heater increases the electric capacity used for heating the heater in the total electric capacity generated by the power generation cells of the fuel cell, resulting in an increase in power generation loss of the entire fuel cell system. There was a point.

The present invention has been completed in view of the above-described problems in the prior art, and its purpose is to supply fuel to the fuel reformer satisfactorily, as well as hydrogen gas reformed by the fuel reformer, etc. with the gas can be safely discharged out of the fuel reformer housing container, to provide a low power loss fuel reformer accommodating container.

  The container for housing a fuel reformer of the present invention includes a base body having a recess on the upper surface that houses a fuel reformer that generates a reformed gas containing hydrogen gas from fuel, and the upper surface of the base body covers the recess. And a lid that is attached to the fuel reformer by passing through at least one of the base body and the lid, and the fuel reformer is connected to the bottom surface of the lid and the recess. A supply pipe for supplying the fuel to the fuel reformer, which is floated and fixed in a space therebetween, and at least one of the base body and the lid body, the tip is joined to the fuel reformer And a discharge pipe for discharging the reformed gas, which floats and fixes the fuel reformer in a space between the lid and the bottom surface of the recess.

  In the fuel reformer storage container of the present invention, preferably, the supply pipe and the discharge pipe have a thermal conductivity of 120 W / m · K or less.

  In the fuel reformer storage container of the present invention, preferably, the discharge pipe has an opening area larger than an opening area of the discharge hole of the fuel reformer.

The container for housing a fuel reformer according to the present invention includes a base body having a concave portion for accommodating therein a fuel reformer for generating a reformed gas containing hydrogen gas from the fuel, and a concave portion on the upper surface of the base body. The attached lid, and at least one of the base body and the lid, penetrate the tip and are joined to the fuel reformer, and the fuel reformer is floated and fixed in a space between the lid and the bottom surface of the recess. A feed pipe for supplying fuel to the fuel reformer, and at least one of the base body and the lid body, the tip is joined to the fuel reformer, and the fuel reformer is connected to the bottom surface of the lid body and the recess. fixing the float in the space between the to and a discharge pipe for discharging the reformed gas, from Rukoto the reformer is fixed only by the supply pipe and the discharge pipe, the base and lid The entire back surface of the fuel reformer can be directly joined to the inside or via a base There is no need to engage or fuel reformer heat can be effectively prevented from being transmitted to the substrate and the lid. As a result, the fuel reformer can be insulated to suppress the temperature drop of the fuel reformer, and a large amount of electric power is supplied to the heater to maintain the temperature necessary for operating the fuel reformer well. There is no need to continue, and the power generation efficiency can be significantly improved.

  In addition, since the heat conduction from the fuel reformer to the base body and the lid can be greatly reduced, it is possible to effectively suppress the temperature rise on the outer wall surface of the fuel reformer storage container. As a result, it is possible to effectively prevent other components in the portable device from being destroyed or causing a burn to the user of the portable device.

  In the fuel reformer storage container of the present invention, the heat conductivity of the supply pipe and the discharge pipe is 120 W / m · K or less. The heat transmitted to the fuel can be more effectively reduced, and the temperature reduction of the fuel reformer and the temperature rise of the fuel reformer storage container can be more effectively performed.

  Since the opening area of the discharge pipe is larger than the opening area of the discharge hole of the fuel reformer, the fuel reformer storage container of the present invention has a resistance to the flow of reformed gas from the fuel reformer to the discharge pipe. The fuel reforming efficiency can be greatly improved by smoothly discharging the reformed gas from the fuel reformer.

  Embodiments of the fuel reformer storage container of the present invention will be described in detail below.

  FIG. 1 is a sectional view showing an example of an embodiment of a fuel cell storage container according to the present invention. 1 is a base, 2 is a lead terminal as a wiring, 3 is a bonding wire, 4 is a lid, 5a is a supply pipe as a supply path for supplying fuel, 5b is a discharge pipe as a discharge path for discharging reformed gas, 7 is an electrode, 8 is an insulating sealing material for sealing and fixing the lead terminal 2 in the through hole of the base body 1 while insulating, 9 is a fuel reformer, and these base body 1, lid body 4, supply A fuel reformer storage container 11 for storing the fuel reformer 9 is constituted by the pipe 5a and the discharge pipe 5b.

Both the base body 1 and the lid body 4 in the present invention have a role as a container for storing the fuel reformer 9. They are, for example Fe-based alloy, oxygen-free copper, or a metal material such as SUS, aluminum oxide _(Al 2 _{O 3)} sintered material, mullite _{(3Al 2 O 3 · 2SiO 2} ) sintered material, silicon carbide ( SiC) sintered body, aluminum nitride (AlN) sintered body, silicon nitride (Si ₃ N ₄ ) sintered body, glass ceramics and other ceramic materials, and high heat resistant resin materials such as polyimide Yes.

The glass ceramics applicable to the substrate 1 and the lid 4 are composed of a glass component and a filler component. As the glass component, for example, SiO ₂ —B ₂ O ₃ system, SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ system, SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ —MO system (where M is Ca, Sr, Mg, Ba or Zn), SiO ₂ —Al ₂ O ₃ —M ¹ O—M ² O system (where M ¹ and M ² are the same or different and Ca, Sr, Mg, Ba or Zn), SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ —M ¹ O—M ² O system (where M ¹ and M ² are the same as above), SiO ₂ —B ₂ O ₃ — M ³ ₂ O system (where M ³ represents Li, Na or K), SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ —M ³ ₂ O system (where M ³ is the same as above) , Pb glass, Bi glass and the like.

Examples of the filler component include a composite oxide of Al ₂ O ₃ , SiO ₂ , ZrO ₂ and an alkaline earth metal oxide, a composite oxide of TiO ₂ and an alkaline earth metal oxide, Al ₂ O _3. And composite oxides containing at least one selected from SiO ₂ (for example, spinel, mullite, cordierite) and the like.

  On the other hand, when the base body 1 and the lid 4 are formed of a dense aluminum oxide sintered body having a relative density of 95% or more, for example, first, rare earth oxide powder or aluminum oxide powder is added to the aluminum oxide powder. A raw material powder of an aluminum oxide sintered body is prepared by adding and mixing a sintering aid such as the above. Next, an organic binder and a dispersion medium are added to this raw material powder, mixed to form a paste, and this paste is green by a doctor blade method, or an organic binder is added to the raw material powder, and press forming, rolling forming, etc. A sheet is produced. Then, after aligning and laminating and pressing a predetermined number of sheet-shaped molded bodies, the laminated body is fired at a firing maximum temperature of 1200 to 1500 ° C. in a non-oxidizing atmosphere, for example. A base body 1 and a lid 4 made of the product are obtained. The base 1 and the lid 4 may be molded by a powder molding press method.

  On the other hand, when the base 1 and the lid 4 are made of a metal material, they are formed into a predetermined shape by a cutting method, a press method, a MIM (Metal Injection Mold) method, or the like.

  Further, when the base 1 and the lid 4 are made of a metal material, the surface thereof is subjected to a coating treatment such as Au or Ni plating or a resin coating such as polyimide in order to prevent corrosion. Is desirable. For example, in the case of Au plating treatment, the thickness is desirably about 0.1 to 5 μm.

  Further, by covering at least the inner surface of the fuel reformer storage container 11 composed of the base body 1 and the lid 4 with a plating film of Au or Al, the radiant heat generated in the stored fuel reformer 9 is generated. This can be prevented efficiently, and the temperature rise of the fuel reformer storage container 11 can be suppressed.

Bending over the base body 1 and the lid body 4, such as the downsizing of the fuel reformer housing container 11, although in order to enable low profile should reduce the thickness, the mechanical strength The strength is preferably 200 MPa or more.

  Next, the lead terminal 2 in the present invention is preferably made of a metal having the same or approximate thermal expansion coefficient as that of the base body 1 and the lid body 4, for example, made of Fe—Ni alloy or Fe—Ni—Co alloy. However, it is possible to prevent the occurrence of thermal strain with respect to temperature changes during practical use. In addition, a good sealing property between the lead terminal 2 and the substrate 1 can be obtained, the bonding property is excellent, and the strength necessary for mounting and good solderability and weldability can be secured.

Further, the insulating sealing material 8 of the present invention is made of, for example, a glass material such as borosilicate glass, alkali glass, or insulating glass mainly containing lead, or a ceramic material such as aluminum oxide, and is formed on the substrate 1. The base 1 and the lead terminal 2 are electrically insulated by the insulating sealing material 8 in the through hole, and the lead terminal 2 is sealed and fixed. The through-hole through which the lead terminal 2 formed in the base body 1 is inserted needs to have a size that prevents the base body 1 and the lead terminal 2 from coming into electrical contact with each other. An inner diameter that can secure a distance of 0.1 mm or more from the base 1 to the base 1 is required.

When the insulating sealing material 8 is made of a ceramic material such as aluminum oxide, the lead terminal 2 is inserted into the through hole of the base 1 through the insulating sealing material 8 made of, for example, a cylindrical ceramic material, and the insulating sealing material 8 is sealed. The connection between the stopper 7 and the substrate 1 and the insulation sealing material 8 and the lead terminal 2 can be made with a brazing material such as Au—Ge or Ag—Cu.

The electrode 7 on the fuel reformer 9 and the lead terminal 2 are electrically connected via the bonding wire 3. By further seals the recess of the base body 1 with the lid 4, seal the fuel reformer 9 accommodated in the recess of the fuel reformer housing container 11 airtight.

  Further, the fuel reformer 9 accommodated in the fuel reformer accommodating container 11 of the present invention applies a semiconductor manufacturing technology as a fine chemical device, for example, a semiconductor such as silicon, quartz, glass, ceramics, etc. A liquid channel is created by forming a narrow groove on the base material of the inorganic material by a cutting method, an etching method, a blasting method, etc., and a cover such as a glass plate is provided for the purpose of preventing evaporation of the liquid during operation. Used in close contact with the surface by anodic bonding brazing or the like.

  A thin film heater (not shown) composed of a temperature control mechanism, for example, a resistance layer, is formed in the fuel reformer 9, and an electrode 7 is formed on the surface as a terminal for supplying power to the thin film heater. The By adjusting the temperature condition to about 200 to 800 ° C. corresponding to the fuel reforming condition by this temperature adjusting mechanism, the fuel supplied from the fuel supply port to which the supply pipe 5a is connected is combined with the steam, The reforming reaction for generating hydrogen gas from the discharge pipe 5b connected to the discharge port can be favorably promoted.

The fuel reformer 9 has a cover 4 attached to the base 1 so as to cover the concave portion by bonding with a metal brazing material such as Au alloy, Ag alloy, Al alloy, or a glass material, or by a seam weld method. The fuel reformer is stored in the container 11 for storing the fuel reformer.

  For example, in the case of joining with an Au—Sn brazing material, an Au—Sn brazing material formed by welding a Au—Sn brazing material to the lid 4 in advance or punching using a mold or the like is used. After the material is placed between the base body 1 and the lid body 4, the lid body 4 is joined to the base body 1 by a sealing furnace or a seam welder to thereby reform the fuel inside the fuel reformer storage container 11. The vessel 9 can be sealed.

To further improve the thermal insulation of the fuel reformer housing container 11 is Ru effective der to the fuel reformer accommodating container 11 to a vacuum. The fuel reformer housing container 11 to the vacuum, when sealing the fuel reformer 9, perform the sealing by seam weld technique in the sealing or vacuum chamber by the brazing material in a vacuum oven It ’s fine.

  In the fuel reformer 9, the electrode 7 on the fuel reformer 9 is electrically connected to the lead terminal 2 provided on the substrate 1 through the bonding wire 3. Thereby, the heater formed on the fuel reformer 9 can be heated through the electrode 7. As a result, the reaction temperature can be maintained in the fuel reformer 9, and the fuel reforming reaction can be stabilized.

The supply pipe 5a and the discharge pipe 5b are a supply path for raw materials and fuel gas fluid and a discharge path for reformed gas containing hydrogen, respectively. These include, for example, Fe-Ni alloy, Fe-Ni-Co alloy, a metal material such as SUS, _Al 2 _{O 3} sintered _material, 3Al ₂ O 3 · 2SiO ₂ sintered material, SiC sintered material, It is formed of a ceramic material such as an AlN sintered body, a Si ₃ N ₄ sintered body, a glass ceramic sintered body, a high heat-resistant resin material such as polyimide, or glass.

  Preferably, it is difficult to be embrittled by hydrogen contained in the reformed gas. Such materials include Fe alloys, ceramics, and glass.

  The heat conductivity of the supply pipe 5a and the discharge pipe 5b is preferably 120 W / m · K or less. Thereby, the heat transmitted from the fuel reformer 9 to the base body 1 and the lid body 4 through the supply pipe 5a and the discharge pipe 5b can be more effectively reduced, and the temperature drop of the fuel reformer 9 can be suppressed. It is possible to more effectively suppress the high temperature of the fuel reformer storage container 11.

  The opening area of the discharge pipe 5b is preferably larger than the opening area of the discharge hole of the fuel reformer 9. Thereby, the resistance of the reformed gas flow from the fuel reformer 9 to the discharge pipe 5b can be reduced, and the reformed gas can be smoothly discharged from the fuel reformer 9 to improve the efficiency of fuel reforming. It can be greatly improved.

Specifically, the difference between the opening area of the discharge pipe 5b and the opening area of the discharge hole of the fuel reformer 9 is preferably 350 mm ² or less. As a result, it is possible to effectively suppress the occurrence of stress due to thermal expansion or the like at the joint portion between the exhaust pipe 5b and the fuel reformer 9, and to maintain the joint strength of this joint portion, and to improve the discharge efficiency of the reformed gas Can be further improved.

  The fuel pipe 5a and the discharge pipe 5b are inserted into through holes formed in the base 1 or around the through holes inside the base 1 with the supply pipe 5a and the discharge pipe 5b of the base 1 being divided. And it joins so that a through hole may be inserted | pinched around the through hole of the base | substrate 1 outer side. As this joining method, depending on the material constituting the supply pipe 5a, the discharge pipe 5b, and the substrate 1, ultrasonic joining, thermal welding, pressure bonding, adhesion with a resin adhesive, or a brazing material such as Au—Si or Ag—Cu is used. Various methods such as bonding, bonding with glass such as borosilicate glass, and simultaneous sintering are appropriately used.

  The inner diameters of the supply pipe 5a and the discharge pipe 5b are preferably set to φ0.1 mm or more so as to suppress the pressure loss of the fluid and to be φ5 mm or less for miniaturization and low profile.

  The cross-sectional shape of the joint portion between the supply pipe 5a and the discharge pipe 5b may be generally circular, but is not limited thereto. That is, besides the circular shape, there are an elliptical shape and a rectangular shape whose side can be aligned with the fluid flow direction, for example, a square shape and a rectangular shape. Further, the thickness needs to be a thickness that does not deform due to the pressure of the raw material supply or reaction gas discharge. When the material is made of the above-mentioned materials, it is usually 0.1 mm or more when used for a portable device or the like. Further, the length in the flow direction is preferably as long as possible to make it difficult for heat generated in the fuel reformer 9 to be transmitted to the power generation cell, but it should be taken into consideration in consideration of the size of the entire fuel cell system.

  Further, the supply pipe 5a and the discharge pipe 5b are formed with a plurality of grooves parallel to the axial direction or a plurality of grooves perpendicular to the axial direction on the outer surface of the portion inside the fuel reformer storage container 11. Is good. As a result, the heat conduction of the supply pipe 5a and the discharge pipe 5b can be reduced to more effectively suppress the heat conduction from the fuel reformer 9 to the base body 1 and the lid body 4, and the supply pipe 5a and the discharge pipe 5b can be appropriately controlled. And the stress can be relieved by appropriate deformation of the supply pipe 5a and the discharge pipe 5b, the joint between the supply pipe 5a and the discharge pipe 5b and the fuel reformer 9, and the supply pipe It is possible to favorably maintain the joint of the joint portion between the base 5 or the discharge pipe 5b and the base body 1 or the lid body 4.

Further, the fuel supply port of the fuel reformer 9, the fuel discharge port, and the supply pipe 5a and the discharge pipe 5b are connected to glass such as quartz glass and borosilicate glass, various ceramics, an inorganic adhesive containing an inorganic polymer, From adhesives containing high heat-resistant organic materials such as polyimide amide, organosilicon compounds such as silicone rubber and silicon resin, various brazing materials such as Au-Sn alloy, Au-Si alloy, Au-Ge alloy, Ag-Cu alloy connection to use those made, the connection method by anodic bonding without using a bonding material can be applied, thereby hermetically sealed.

  In addition, this invention is not limited to the example of the above embodiment, A various change may be added in the range which does not deviate from the summary of this invention. For example, in the example shown in FIG. 1, the fuel pipe 5a and the discharge pipe 5b are joined to the lower surface of the fuel reformer 9, but these are joined to the upper surface according to the specifications of the fuel reformer 9. Also good. A plurality of supply pipes 5a and discharge pipes 5b may be formed.

It is sectional drawing which shows an example of embodiment of the container for fuel reformer accommodation of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Base | substrate 4 ... Lid body 5a ... Supply pipe 5b ... Discharge pipe 9 ... Fuel reformer
11 ・ ・ ・ ・ ・ Fuel reformer storage container

Claims (3)

A base body having a recess on its upper surface that accommodates a fuel reformer that generates a reformed gas containing hydrogen gas from fuel; a lid that is attached to the upper surface of the base body so as to cover the recess; and The fuel reformer, which penetrates at least one of the lids and has a tip joined to the fuel reformer and floats and fixes the fuel reformer in a space between the lid and the bottom surface of the recess. A supply pipe for supplying the fuel to a mass device, and at least one of the base body and the lid body, the tip is joined to the fuel reformer, and the fuel reformer is connected to the lid body and the lid A discharge pipe for discharging the reformed gas, which floats and is fixed in a space between the bottom surface of the recess, and the reformer is fixed only by the supply pipe and the discharge pipe. A fuel reformer storage container. 2. The fuel reformer storage container according to claim 1, wherein the supply pipe and the discharge pipe have a thermal conductivity of 120 W / m · K or less. 3. The fuel reformer storage container according to claim 1, wherein an opening area of the exhaust pipe is larger than an opening area of an exhaust hole of the fuel reformer.

Images