JPS6379707A - Burner of reformer for fuel cell - Google Patents

Abstract

PURPOSE:To reduce the consumption of energy required to fire liq. fuel and to prevent the wasteful flow of liq. fuel and the contamination of the combustion part of a burner in which liq. fuel is burned, by putting a catalyst for ignition under the flame generating spots of the combustion part. CONSTITUTION:Plural fuel feeding nozzles 2 are fitted to the outside of a circular fuel evaporator 1 and mixed liq. fuel consisting of methanol and water is fed from the nozzles 2. A burner 3 is placed under the evaporator 1 and the liq. fuel is gasified by heating with the burner 3. Plural reaction tubes 4 are connected to the top of the evaporator 1 and packed with a catalyst to form catalyst beds 5. A catalyst 17 for ignition is fitted to combustion tubes 13 for liq. fuel so that liq. fuel can be fired in the initial stage without preheating with large electric power. Even when liq. fuel leaks out of the small holes 15 of the tubes 13 before ignition, it is captured by the lower catalyst 17 and is not dropped.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a combustion device provided as a heat source for a fuel cell reformer.

[Prior art]

A fuel cell mainly consists of a reformer that changes fuel into a reformed gas consisting mainly of hydrogen, and a system that reacts the hydrogen in the reformed gas generated by this reformer with air (oxygen) to convert it into water and electrical energy. It consists of a fuel cell body. A reformer requires a heat source to vaporize liquid fuel such as methanol and to react the vaporized fuel in the catalyst layer to form reformed gas, and a combustor (burner) is used as the heat source. It is common to

By the way, when liquid fuel is used as the fuel for the combustor, it has the advantage that the storage capacity of the liquid fuel is smaller than that of gaseous fuel, so the device can be made more compact, which is particularly advantageous for portable fuel cells. It is. However, on the other hand, since liquid fuel has poor initial ignition properties, it is necessary to preheat it with a heater or the like in order to ignite it, which has the disadvantage that energy consumption such as electric power is considerably large. Furthermore, the fuel discharged from the combustion section before ignition drips downward, causing contamination and wasting the fuel.

[Purpose of the invention]

An object of the present invention is to reduce the energy consumption for ignition when using liquid fuel, which is advantageous for making the device more compact, and to prevent wasteful dripping of fuel and fouling of the combustion section. An object of the present invention is to provide a combustion device for a reformer.

[Structure of the invention]

To achieve the above object, the present invention provides a fuel cell reformer in which a fuel evaporator is heated by a combustor, and the fuel vaporized by the fuel evaporator is converted into reformed gas by a catalyst layer. It is characterized by having an ignition catalyst disposed below the flame generating part of the combustion part.

〔Example〕

1 to 3 show a combustion apparatus according to an embodiment of the present invention, and FIG. 4 shows an example of a fuel cell reforming system and a wheat dressing in which the combustion apparatus is used.

In FIG. 4, 1 is an annularly formed fuel evaporator;
Around it a fuel supply nozzle 2,-.

2 are attached to multiple locations to supply a liquid fuel mixture of methanol and water. A combustor 3, the details of which will be described later, is installed below the fuel evaporator 1, and the liquid fuel is vaporized by heating by the combustor 3.

On the upper surface of the fuel evaporator 1, there are a plurality of reaction tubes 4. ..., 4
are connected, and the inside of each reaction tube 4 is filled with a catalyst to form a catalyst layer 5. In this catalyst layer 5, the fuel vaporized in the fuel evaporator 1 undergoes a reaction to change into reformed gas consisting mainly of hydrogen, which is collected in an upper collecting chamber 6 and further sent to the fuel cell main body (not shown). It has become.

In addition, a plurality of reaction tubes 4. -, 4 are surrounded by a heat insulating wall 7, forming a space heated by the heated gas rising from the combustor 3. A large number of exhaust holes 8, -, 8 are provided in the upper part of the heat insulating wall 7, and the heated gas in the heating space is discharged to the outside.

In the combustor 3 shown in FIGS. 1 to 3, 18 is a gaseous fuel supply pipe through which surplus hydrogen discharged without reacting with air (oxygen) in the fuel cell body is supplied as gaseous fuel. This gaseous fuel supply pipe 18 is connected to an annular combustion pipe 19, and a large number of small holes 20 are bored along the circumferential direction of the combustion pipe 19. - Gaseous fuel flows out from the -220 and burns.

On the other hand, 10 is a liquid fuel supply pipe, and the amount of liquid fed (rotation speed)
A pump 11 is connected to the pump 11 and supplies liquid fuel such as methanol from a fuel tank (not shown). This liquid fuel supply pipe 10 is connected to a distribution pipe 12, and the distribution pipe 12 further includes a large number of combustion pipes 13. -.-913 is connected.

The upper end of each combustion tube 13 is rounded into a loop shape to form a bifurcated shape, both legs of which are connected to the annular distribution pipe 12, and the inside is filled with asbestos.

A melt 14 made of glass fiber or the like is inserted. Furthermore, one or more small holes 15. -..., 15 are bored, and the dissolved fuel 14 inside faces the outside air through the small holes 15, from which the liquid fuel evaporates and burns.

Multiple combustion tubes 13. -..., 13, a horizontal member 16 is fixed near the upper end thereof so as to straddle the entirety thereof,
Each combustion tube 13 is stabilized so as not to vibrate. Further, a mat-like ignition catalyst 17 is held between the horizontal member 16 and the gaseous fuel combustion pipe 19, and the combustion pipe 13
．． It is located below the small hole 15.20 which is the flame generating part of No. 19. Furthermore, a heater 21 such as a nichrome wire is buried in the ignition catalyst 17 in an annular shape (see Fig. 3).
, the ignition catalyst 17 is activated by generating heat by applying electricity from the lead wires 22 and 22.

Further, on the outer periphery of this ignition catalyst 17, nozzles 23. -..., 23 are arranged so that liquid fuel is injected toward the ignition catalyst.

Since the liquid fuel is injected from this nozzle 23 only at the time of ignition, a fuel supply system separate from the liquid fuel supply pipe 10 is provided, and from the ignition liquid fuel supply pipe 24 to the distribution pipe 25.
It is to be supplied via. Further, since the fuel is not for combustion, no dissolved gas is inserted into this nozzle 23.

According to the above-mentioned combustion device, since the ignition catalyst 17 is attached to the combustion pipe 13 for liquid fuel, initial ignition can be performed without preheating with large electric power as in the conventional case. Moreover, since the ignition catalyst 17 is arranged below the flame generating part (small hole 15) of the combustion tube 13, it is not constantly exposed to flame after ignition, and the life of the catalyst can be extended.

Further, even if liquid fuel leaks from the small hole 15 of the combustion tube 13 before ignition, it will be captured by the ignition catalyst 17 below, so it will not drip downward. Since the fuel is burned and extinguished at the same time as ignition, fuel is not wasted and the combustion section is not contaminated.

Further, when igniting, if liquid fuel is actively injected from the nozzle 23 to the ignition catalyst 17 as in the above embodiment, the ignition time can be shortened. Furthermore, if the heater 21 is used in combination to activate the catalyst as in the embodiment, it is possible to shorten the -layer ignition time.

Since this heater 21 only activates the catalyst, it does not consume a large amount of electric power unlike the fuel preheating heater of the conventional device, and the amount of energy consumption can be extremely reduced.

〔Effect of the invention〕

As mentioned above, the present invention uses an ignition catalyst in the combustion section that burns liquid fuel, so the energy consumption for ignition is reduced compared to the conventional device that preheats with a heater. can do. Moreover, since the above-mentioned ignition catalyst is placed on the lower side of the flame generation part of the combustion part,
Even after ignition, the ignition catalyst is not exposed to flame, and the life of the ignition catalyst can be extended.

Furthermore, even if liquid fuel leaks from the combustion section before ignition, it is captured by the ignition catalyst below, so it burns and disappears at the same time as ignition, thereby preventing contamination of the combustion section and waste of fuel.

[Brief explanation of the drawing]

FIG. 1 is a side view showing a combustion device according to an embodiment of the present invention;
2 is a plan view of the same, FIG. 3 is a view taken along the line mm in FIG. 1, and FIG. 4 is a longitudinal cross-sectional view showing an example of a fuel cell reformer using the same combustion apparatus. DESCRIPTION OF SYMBOLS 1...Fuel evaporator, 3...Combustor, 4...Reaction tube, 5...Catalyst layer, 1O...Liquid fuel supply pipe, 12...Distribution pipe, 13...Combustion Tube, 14...
・Dissolved, 15... Small hole (flame generation part), 17...
Catalyst for ignition, 23... Nozzle, 24... Liquid fuel supply pipe for ignition, 25... Distribution pipe. Figure 4

Claims (3)

[Claims] (1) In a fuel cell reformer that heats a fuel evaporator with a combustor and converts the vaporized fuel in the fuel evaporator into reformed gas in a catalyst layer, the combustor is combusted with liquid fuel, and the combustion A combustion device for a fuel cell reformer, characterized in that an ignition catalyst is disposed on the lower side of a flame generating section. (2) A combustion device for a fuel cell reformer according to claim 1, wherein the combustion section comprises a wick combustion mechanism. (3) A combustion device for a fuel cell reformer according to claim 2, further comprising an ignition fuel system for injecting liquid fuel to an ignition catalyst, in addition to a combustion fuel system for the combustion section.