JPH02101314A - Modifying apparatus - Google Patents

Abstract

PURPOSE:To prevent modifying tubes from being over-heated in a modifying apparatus for a fuel battery power plant by blowing a portion of combustion air for a burner towards modifying tubes. CONSTITUTION:A portion of combustion air 11 for a burner 9 is branched and supplied to air supply lines 17 of an air supply unit 16, and blown towards the top portion of modifying tubes 2 through nozzles 18 after the air flow rate is regulated by valves 19. The air blown is mixed with high temperature combustion gas 8 to decrease the temperature of the high temperature combustion gas 8 that flows towards the over-heated reforming tubes 2, thereby decreasing the temperature of the modifying tubes. Thus, the modifying tubes 2 is prevented from being over-heated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Objectives of the Invention) (Industrial Application Field) The present invention relates to a reformer for a fuel cell power generation plant, and more particularly to a reformer that prevents overheating of the reforming tube.

(Prior art) In a fuel cell power generation plant, in order to obtain hydrogen gas, which is the fuel for the fuel cell itself, raw fuels for the plant, such as natural gas, naphtha, and methanol, are converted into steam at a high temperature of about 800°C under a catalyst. A fuel reforming process is being carried out to convert hydrogen into a hydrogen-rich gas fuel by combining it with hydrogen. A fuel reforming plant that performs the above process, which is an endothermic reaction, usually contains raw fuel for the plant during startup and temperature rise, and surplus hydrogen gas in the fuel cell body during plant load operation. It is a heating reactor whose heat source is a burner that uses battery waste fuel as fuel, and is generally combined with a reformer (
It is called rifoma).

An example of a conventional reformer will be explained using FIG. 4.

A large number of reforming tubes 2 extending in the vertical direction are accommodated in the pressure vessel 1, and each reforming tube 2 consists of an outer tube 2a and an inner tube 2b extending on the same axis. ) is occluded. Between the outer tube 2a and the inner tube 2b of the reforming tube 2 and the inner tube 2b constitute a flow path for the process gas 3.
A contact plate 4 is provided between the inner tube 2b and the inner tube 2b. The process gas 3 consists of a mixed gas of the raw fuel and steam, and the reformer tube 2 is a heat exchanger tube made of a heat-resistant alloy steel tube.

The container 1 has an inlet 5 for introducing the process gas 3 into the reforming tube 2, and a reformed gas (hydrogen) generated in response to the process gas 3 flowing through the reforming tube 2. An outflow hole 7 for sending out rich gas) 6 is provided.

On the other hand, a burner 9 is provided in the upper part of the pressure vessel 1 to supply high-temperature combustion gas 8 to heat the reforming tube 2.
10tfi of burner fuel such as the raw fuel or battery waste fuel is used.
At the same time, combustion air 11 for combusting this burner fuel 10 is also introduced.

The pressure volume 41 has an outlet 14 for discharging the burner gas 13 generated after the reformer tube 2 is heated by the high-temperature combustion gas 8 generated by burning the burner fuel 10 in the combustion chamber 12 by the burner 9 .

In the reformer, the process gas 3 introduced into the pressure vessel 1 from the inlet 5 rises inside the reforming tube 2 through the flow path formed between the outer tube 2a and the inner tube 2b, During that time, due to the action of the catalyst 4 provided between the outer tube 2a and the inner tube 2b and the supply of heat from the high temperature f1 burnt gas 8 supplied from the burner 9, the raw fuel and water vapor are combined, resulting in hydrogen-rich gas. becomes.

After this hydrogen-rich gas hits the top of the outside @ 2a of the reforming tube 2, it changes direction and flows downward through the inner tube 2b, and from the outflow lower provided at the bottom of the pressure vessel 1, the reformed gas 6 sent out as.

(Problems to be Solved by the Invention) In the conventional reformer, combustion is carried out under pressure within the pressure vessel 1.
Although it is possible to reduce the size of the container and reduce heat loss, it is also possible to reduce the size of the combustion chamber 12 due to restrictions on the shape and dimensions of the combustion chamber 12, which is the space where the burner 9 performs combustion, and the mounting position and direction of the burner 9. The combustion gas temperature distribution in the radial direction and circumferential direction tends to be uneven. Further, due to variations in pressure loss between the inside and outside channels of the reforming tubes 2, the flow rate distribution of the high-temperature combustion gas 8 and the process gas 3 may be uneven between the reforming tubes 2.

For this reason, some of the reformer tubes 2 may be locally overheated and damaged, or other reformers 1rff 12 may not be heated to a temperature high enough for the fuel reforming reaction.

The present invention has been made in consideration of the circumstances described in -F, and an object of the present invention is to provide a reformer that can prevent local overheating of a reforming tube housed in a pressure vessel.

(Structure of the Invention) (Means for Solving the Problems) The reformer according to the present invention includes a large number of reforming tubes in a B-force vessel, through which process gas flows and is converted into reformed gas by the action of a catalyst. In a reformer that is housed in a reformer and is equipped with a burner that supplies high-temperature combustion gas that heats these reforming tubes, a part of the combustion air from the burner is blown toward the reforming tubes to perform reforming. It is equipped with an air supply system to prevent overheating of the pipes.

(Function) When local overheating occurs in the reforming tube in the pressure vessel, a part of the combustion air of the burner is blown toward the superheated reforming tube by the air supply system, and the area near the reforming tube is By lowering the temperature of the combustion gas, overheating of the reformer tube can be reduced.

Therefore, damage to the reforming tube can be prevented.

(Actual ttgti*> An embodiment of the reformer according to the present invention will be described with reference to FIGS. 1 to 3.

In FIGS. 1 to 3, the same parts as in FIG. 4 are designated by the same reference numerals, and detailed description thereof will be omitted.

A part of the combustion air 11 of the burner 9 is transferred to the reformer through a reforming tube 2.
An air supply system a16 is provided to prevent the reformer tube 2 from overheating by blowing toward the reformer tube 2.

The air supply system 16 includes an air supply line 17 that branches off and guides a part of the combustion air 11, and the air guided by the air supply line 17 is directed toward the top of the reforming tube 2 and is connected to the combustion chamber. An air inlet nozzle 18 for blowing into the air filter 12 and a valve for regulating the air flow are provided. It is desirable that the air inflow nozzles 18 are provided at least four places on the immediate side in the circumferential direction of the pressure vessel 1. However, the first
In the figure and FIG. 2, only two locations in the cross section are shown. The air inflow nozzle 18 includes a head plate 20 provided to cover the outer periphery of the pressure vessel 1 and a heat insulating material 2 provided inside the head plate 20.
1 and the setting is -J.

Next, the operation of the above embodiment will be explained.

In the embodiment described above, first, all the valves 19 are set to full position or set to the same opening degree before operation.

Suppose now that during operation, for some reason, the reforming tube group 22 shown by hatching in FIG. 3 becomes heated.

In that case, as shown in FIG.
By opening the valve 19a of the air inflow nozzle 18a facing the air inflow nozzle 18a, air 23 is blown from the air supply line 17a through the valve 19a1 and the air inflow nozzle 18a toward the heated reforming tube group 22. The blown air 23 mixes with the high-temperature combustion gas 8 to lower the temperature of the high-temperature combustion gas 8a heading toward the superheated reformer tube gT 22, and as a result, the temperature of the 4-quality tube group 22 decreases.

In this way, according to the above embodiment, the local 'i4 heat of the reforming tube 2 provided in the reformer is reduced by the local reduction of the combustion gas temperature by blowing air into the combustion chamber 12. In addition to silently preventing damage to the reforming tube 2, by uniformly increasing the reforming tube temperature to the high temperature section where sufficient reforming reaction takes place, the system can be operated properly. can be achieved.

It should be noted that the present invention is not limited to the above-described embodiments, but may also include an orifice or the like used as the W4X means for inflowing air blown into the combustion chamber 12, or an air inflow nozzle 18 provided in the body of the pressure vessel 1. It also includes those in which air inflow nozzles 18 are provided not only in the circumferential direction of the end plate 20 but also in the radial direction.

〔Effect of the invention〕

The reformer according to the present invention is equipped with an air supply system that blows part of the combustion air of the burner toward the reforming tube to prevent the reforming tube from overheating. It is possible to prevent local overheating of the quality tube and ensure proper system operation.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the configuration of a reformer according to the present invention, and FIG.
The figure is an enlarged cross-sectional view showing the vicinity of the combustion chamber in the above-mentioned JPA, Figure 3 is a cross-sectional view taken along the line ■-■ in Figure 2, and Figure 4 is a cross-sectional view showing a conventional reformer. be. 1... Pressure vessel, 2... Reforming pipe, 4... Catalyst, 9
... Burner, 16... Air supply system. Representative Patent Attorney Nori Chika Ken Shu Kanshu Daiko Maru Ken Figure 1 Figure Figure Figure Figure 1

Claims (1)

[Claims] A reformer is equipped with a pressure vessel containing a large number of reforming tubes that circulate process gas and convert it into reformed gas through the action of a catalyst, and is equipped with a burner that supplies high-temperature combustion gas to heat these reforming tubes. A reformer comprising an air supply system that blows part of the combustion air of the burner toward the reforming tube to prevent overheating of the reforming tube.