JPS62154474A - Fuel reformer of fuel cell - Google Patents

Abstract

PURPOSE:To increase heat efficiency and to make compact and to obtain a large amount of reformed gas by arranging a heater in the lower part of a fuel evaporator, jointly mounting a reaction tube in the upper part, and connecting the heater and the reaction tube through a heating gas passage formed in the inside of the region surrounding the outermost circumference. CONSTITUTION:A fuel evaporator 1 is directly heated with a burner 3 to vaporize liquid fuel, the vaporized fuel is supplied to plural reaction tubes 4. Heating gas in the burner 3 passes upward through a passage 15 formed in the center of the fuel evaporator 1 and heats the reaction tubes from the outside to convert vaporized fuel into reformed gas mainly comprising hydrogen gas by water vapor reforming reaction. Thereby, a system is made compact and heat of heating gas is effectively utilized to decrease loss and also obtain a large amount of reformed gas.

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. ing.

In the past, fuel cells were mainly developed for large, plant-grade ones that used liquefied natural gas as fuel, but recently, fuel cells that use liquid fuel such as a mixture of methanol and water and can be easily transported by cars etc. There is also a demand for the development of a small-sized device that can do this.

The challenge for such small fuel cells is to increase the thermal efficiency of the fuel reformer that obtains reformed gas mainly composed of hydrogen gas from mixed liquid fuel, and to make it possible to obtain a large amount of reformed gas while maintaining a compact configuration. That's true.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a fuel reformer for a fuel cell that has high thermal efficiency and is compact in structure, yet can efficiently obtain a large amount of reformed gas.

[Structure of the invention]

The fuel reformer of the present invention that achieves the above object has a heater disposed at the bottom of the fuel evaporator that vaporizes liquid fuel, a reaction tube integrally mounted on the upper surface, and the outermost periphery of the fuel evaporator. A heating gas passage is formed inside the surrounding area, and the heater side and the reaction tube side are communicated via this heating gas passage.

〔Example〕

Hereinafter, the present invention will be explained 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
A 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 steam reforming reaction in the reformer 30 is performed as an endothermic reaction represented by the following reaction formula.

CH30H+HzO-3Hz+C(h -11,8kc
Air is separately supplied to the fuel cell main body 31, and hydrogen gas in the reformed gas reacts 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. Reference numeral 1 denotes a fuel evaporator, which is formed into an annular shape having a heating gas passage 15 in the center. There are nozzles 2. . . . -12 is attached so that a liquid fuel mixture of methanol and water is supplied inside. A heater 14 consisting of a burner 3 housed in a case 13 is provided below the fuel evaporator 1 .

A cylindrical inner wall 8 is provided around the fuel evaporator 1, and an outer wall 10 is provided on the outside thereof with a heat insulating layer 9 such as glass wool or ceramic wool interposed therebetween. On the upper surface of the fuel evaporator 1, there are a plurality of reaction tubes 4 along its annular shape.
. . . , 4 are vertically erected integrally, and the reaction tube 4 is filled with a catalyst layer 5 made of a pellet-shaped catalyst such as copper, platinum, or rhodium. Multiple reaction tubes 4,...
. . , 4 is connected to a collecting portion 6 at its upper end and communicates with the inside of these reaction tubes. Further, the collecting portion 6 closes the upper end portion of the inner wall 8 with its lower surface, thereby preventing the heating gas from the burner 3 from escaping upward. In the upper part of the inner wall 8, there are a number of exhaust holes 11.・・・・−
..., 11 is a heat insulating layer 9. It is provided so as to communicate to the outside through the outer wall IO.

In addition, a plurality of reaction tubes 4. A dispersion plate having a large number of through holes 12a, . . . , 12a in an inner space surrounded by these reaction tubes is located at an intermediate position in the length direction of 4. 12 is attached. This dispersion plate 12 is
The heating gas passing from the lower burner 3 through the passage 15 provided at the center of the fuel evaporator 1 is uniformly dispersed so as to come into contact with the outer wall of each reaction tube 4 evenly.

As mentioned above, the fuel evaporator 1 includes a reaction tube 4. Gathering section 6. Although it has an integral structure with the heat insulating part 9 and the like, it is detachable from the heater 14 arranged at the bottom. That is, the lower end of the cylindrical inner wall 8 fixed to the outer periphery of the fuel evaporator 1
Bolts 16 and 7 bolts 17 are attached to the upper end of the case 13 of 4.
The structure is such that they can be detachably connected.

According to the above-described fuel reformer, the fuel evaporator l is directly heated by the burner 3 to vaporize the liquid fuel therein, and the vaporized fuel is sent to the plurality of reaction tubes 4 above. −
・・・・Distributed supply to 4. The heating gas of the burner 3 passes upward through a passage 15 provided in the center of the fuel evaporator 1, and passes through the reaction tube 4. -...-, heat these while contacting the outer walls of 4. Therefore, the vaporized fuel in the reaction tube 4 undergoes the above-mentioned steam reforming reaction to convert the reformed gas to be mainly hydrogen gas.

In this manner, in the fuel reformer having the above configuration, the fuel evaporator 1
The structure of the reactor tube 4 and the reaction tube 4 are integrated, making it compact. Moreover, because of this integration, the heat of the heating gas is effectively used for the vaporization of the liquid fuel and the next steam reforming reaction, so there is no loss during the process, and a large amount of reforming is possible. You can get quality gas.

Further, since the heating gas passage 15 is provided with the fuel evaporator 1 in the center and does not protrude outward, it does not become bulky and has a more compact structure.

Furthermore, since the passage of the heating gas is straight in the vertical direction, the flow is smooth, and since it does not pass outside the fuel evaporator 1, there is no exposure to the outside, and heat loss can be reduced. can.

In the above embodiment, the heating gas passage 15 is formed to pass through the center of the fuel evaporator 1, but this arrangement is not necessarily limited to the area surrounding the outermost periphery of the fuel evaporator 1. It doesn't have to be central.

〔Effect of the invention〕

As described above, in the fuel reformer of the present invention, the heater is disposed at the bottom of the fuel evaporator that vaporizes liquid fuel, the reaction tube is integrally erected on the upper surface, and the outermost periphery of the fuel evaporator is A heating gas passage is formed inside the surrounding area, and the heater side and the reaction tube side are communicated via this heating gas passage. In this way, by integrating the fuel evaporator and the reaction tube, the device becomes compact, and heat loss during the process can be eliminated, allowing a steam reforming reaction to occur with high thermal efficiency. Furthermore, since the heating gas passage is provided in the area surrounding the outermost periphery of the fuel evaporator, the heating gas passage does not become larger due to protruding outward.
A more compact configuration can be achieved.

[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 n-■ arrow in FIG. 1, and FIG. 3 is a view to which the above fuel reformer is applied. FIG. 2 is a system diagram of a fuel cell. 1-fuel evaporator, 3...-burner, 4--reaction tube,
5-catalyst layer, 14...heater, 15-...(
(heating gas) passage. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] A heater is placed at the bottom of the fuel evaporator that vaporizes liquid fuel, a reaction tube is integrally installed on the top surface, and a heating gas passage is formed inside the area surrounding the outermost periphery of the fuel evaporator. A fuel reforming device for a fuel cell, characterized in that the heater side and the reaction tube side are communicated via the heating gas passage.