JPS62138305A - Device for reforming fuel for fuel cell - Google Patents

Abstract

PURPOSE:To reform a large amt. of fuel uniformly and with high reaction efficiency using a compact constitution of a device by evaporating fuel fed from fuel feeding nozzles having >=2 branches with the top ends of the ejecting ports of the branches arranged dispersedly in a fuel evaporating device. CONSTITUTION:Large amt. of methanol/water fuel mixture ejected dispersedly through fuel feeding nozzles 2 having top end ejecting ports 2c arranged dispersedly to plurally branched parts, for example, to two branched parts 2a, 2b fitted to positions opposing to each other, in an evaporator 1, is evaporated uniformly by heating directly the fuel evaporator 1 with a burner 3 of a fuel reforming device 30, and the evaporated fuel mixture is fed to plural reaction tubes 4 provided with a catalyst layer 5 packed with pelletized catalyst, wherein said reaction tubes are erected vertically on the upper surface of the evaporator 1 along its annular periphery. Simultaneously, the reaction tubes 4 are heated with heating gas dispersed by dispersing plates 12 provided with many through holes 12a having function for controlling heating, at 150-500 deg.C to convert to reformed gas consisting principally of H2. The gas is collected in a collecting section 6 and then fed to a main body of a fuel cell from an outlet 7.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a fuel reformer for a fuel cell.

[Prior art]

A fuel cell consists of a reformer that reforms fuel into hydrogen gas, and a fuel cell that reacts the hydrogen gas generated by the reformer with air (oxygen) to convert it into water and electrical energy. It has become. In the past, fuel cells have mainly been developed for large, plant-grade fuel cells that use liquefied natural gas as fuel, but recently there has been a demand for the development of small-sized fuel cells that can be easily transported by automobiles or the like.

Such small fuel cells generally use a liquid mixture of methanol and water as fuel, and this mixed fuel is vaporized and reacted at high temperatures to generate reformed gas, which is mainly hydrogen gas. ing. A fuel reformer that converts this mixed fuel into reformed gas needs to be as compact as possible to improve portability, but on the other hand, it must be able to process as much mixed fuel as possible to increase power generation capacity. It is necessary to do so. That is,
It is required to simultaneously satisfy two mutually contradictory requirements: a compact configuration and the ability to process a large amount of fuel.

[Purpose of the invention]

An object of the present invention is to provide a fuel reformer that can efficiently process a large amount of fuel while having a compact configuration.

[Structure of the invention]

The fuel reformer of the present invention that achieves the above object has a reaction tube connected to the top of the fuel evaporator, and a fuel supply nozzle inserted into the single fuel generator that is branched into two or more branches. The fuel evaporator is characterized in that the discharge ports at the tip are distributed within the fuel evaporator.

〔Example〕

The present invention will be explained below with reference to embodiments shown in the drawings.

FIG. 3 is a system diagram of a fuel cell using a mixed fuel of methanol and water. 30 is a reformer whose details will be described later, and the mixed fuel of methanol and water is
The reaction is carried out at a high temperature of 0 to 500° C. to produce a reformed gas containing hydrogen gas as a main component, which is then supplied to the fuel cell main body 31. The reaction in the reformer 30 is an endothermic reaction expressed by the following reaction formula.

CH,OH+1(2o-3Hz+COz-11,8
kcal Air is separately supplied to the fuel cell main body 31, and hydrogen gas in the reformed gas is reacted with oxygen in the air to generate water and electricity. This electricity can be used as direct current, but if converted by the inverter 32, it can also be used as alternating current.

1 and 2 show the reformer 30 according to an embodiment of the present invention. 1 is a fuel evaporator formed in an annular shape,
Two fuel supply nozzles 2, 2 are attached at mutually opposing positions around the periphery. This fuel supply nozzle 2 supplies a mixed fuel of methanol and water, and is internally divided into two branch parts 2a and 2b, with a discharge port 2 at the tip thereof.
The positions of c and 2c are not concentrated in one place in the fuel evaporator 1, but are dispersed. The number of branches of this nozzle is not limited to two, but may be more than two.

The distribution of the discharge ports 2c is preferably point-symmetrical with respect to the center of the annular fuel evaporator 1, or line-symmetrical with respect to a line passing through the center.

A vanina 3 is provided below such a fuel evaporator 1,
The burner 3 directly heats the fuel evaporator 1, and the liquid fuel supplied from the fuel supply nozzle 2 is vaporized.

A plurality of reaction tubes 4 are arranged along the annular shape on the upper surface of the fuel evaporator 1.
．． -...=, 4 are vertically arranged and communicate with the inside of the fuel evaporator 1, respectively. Inside the reaction tube 4 are pelleted platinum and rhodium.

Alternatively, a catalyst layer 5 filled with a copper-based catalyst or the like is provided. The entire periphery of the integral structure consisting of the fuel evaporator 1 and the reaction tube 4 is a heat insulating section consisting of a cylindrical inner wall 8, a heat insulating layer 9 made of glass wool, ceramic wool, or foam thereof, and an outer wall 10. being surrounded.

Above inner wall 8. Heat insulation layer9. The lower end of the heat insulating section made of the outer wall 10 is formed to extend further downward from the lower surface of the fuel evaporator 1.

The plurality of reaction tubes 4. ...-24 is connected to a collecting part 6 that communicates with the inside of these reaction tubes, and at the same time, the collecting part 6 closes the upper end of the cylindrical inner wall 8 with its lower surface, and the burner 3 is closed. Prevents heated gas from escaping upwards. In the upper part of such an inner wall 8, a large number of exhaust holes 11°--------, 11 are provided with a heat insulating layer 9. It is provided so as to communicate to the outside through the outer wall 10. In addition, a plurality of reaction tubes 4. A dispersion plate 12 having a large number of through holes 12a, . . . 112a is attached at an intermediate position in the length direction of 4, in an inner space surrounded by the plurality of reaction tubes. ing. This dispersion plate 12 uniformly disperses the heated gas from the burner 3 passing upward through the central space of the annular fuel evaporator 1, and brings it into uniform contact with the outer wall of each reaction tube 4. That is, the dispersion Fi 12 has a heating control capability of 48 m, and by varying the number of through holes 12a and the opening area, the required heating control can be achieved.

In the above-mentioned device, the tip discharge port 2 of the fuel supply nozzle 2
The fuel gas of methanol and water discharged from the fuel evaporator 1 from the reactor tubes 4. −・
. . , 4, and when passing through the gap in the catalyst layer 5, the above-mentioned endothermic reaction occurs, and the reformed gas mainly consists of hydrogen gas and carbon dioxide gas. This reformed gas contains by-products such as carbon monoxide and methane gas, as well as unreacted methanol and water residues. After this reformed gas escapes upward and collects in the collecting section 6, it is sent to the fuel cell main body 31 mentioned above from the outlet lower.

According to the fuel reformer described above, the fuel supply nozzle 2 branches into a plurality of parts within the fuel evaporator 1, and the branch parts 2a,
Since the tip discharge ports 2c, 2c of the fuel pump 2b are arranged in a distributed manner, even if a large amount of fuel is supplied, the fuel is dispersed and discharged in small amounts to each tip discharge port 2C. Therefore, the amount of fuel evaporated per unit volume in the fuel evaporator is increased, and evaporation is performed with high heat receiving efficiency, so the throughput is significantly improved despite the compact configuration.

Further, by distributing the discharge ports 2C, it is possible to uniformly supply the vaporized fuel to each reaction tube 4, and to perform an endothermic reaction with good thermal efficiency.

Since the device of the present invention described above can be made compact, it is particularly effective when used as a portable fuel cell.

〔Effect of the invention〕

In the fuel reformer of the present invention, a reaction tube is connected to the top of the fuel evaporator, and the fuel supply nozzle inserted into the fuel evaporator is branched into two or more parts, and these branch parts Since the discharge ports at the tip are distributed in the fuel evaporator, the amount of fuel evaporated per unit volume of the fuel evaporator can be increased, thereby making it possible to efficiently vaporize a large amount of fuel despite the compact configuration. Furthermore, since there is no imbalance in the vaporized fuel, the reaction efficiency in the reaction tube can be improved.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a fuel reformer for a fuel cell according to an embodiment of the present invention, FIG. 2 is a view taken along the ■-■ arrow in FIG. 1, and FIG. 3 is a view taken along the mm--m arrow in FIG. 4 are system diagrams of a fuel cell to which the above fuel reformer is applied. 1--Fuel evaporator, 2-Fuel supply nozzle, 2a, 2
b-branch, 2cm discharge port, 3--burner, 4
~・Reaction tube.

Claims (1)

[Claims] A reaction tube is connected above the fuel evaporator, and the fuel supply nozzle inserted into the fuel evaporator is branched into two or more parts, and the discharge ports at the tips of these branch parts are distributed in the fuel evaporator. Characteristic fuel reformer for fuel cells.