JPS6065472A - Fuel cell device - Google Patents

Abstract

PURPOSE:To reduce combustion temperature by providing a reaction chamber burning the newly supplied fuel with the active heat of the combustion gas generated in the combustion chamber together with the remaining oxygen downstream the catalyst charge and combustion chamber in a fuel hydrogen generation device. CONSTITUTION:A reaction chamber 10A is attached to the lower reaches of the catalyst charge and combustion chamber 10 of the fuel hydrogen generation device for obtaining the fuel for a fuel cell by reforming a kind of hydrogen carbonate under heating. And the waste gas from the battery positive pole together with the added auxillary fuel and the air from the compressor are put into the mixing chamber 11 from the nozzles 12 and 13 and passed through the ceramic tray 14 followed by being burnt in the combustion chamber 10 charged with a catalyst 15 followed by burning the remaining fuel together with the waste gas from the second stage nozzle 12A in the reaction chamber 10A under its active heat and the remaining oxygen. Accordingly, it is sufficient to feed 50-60% of the whole fuel to the combustion chamber 10 while dividing the combustion part thus making it possible to perform reduction of thermal stability while lowering the combustion temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel cell device, and more particularly to a fuel hydrogen generating device for a fuel cell device suitable for lowering the combustion temperature in a catalyst-filled combustion section.

A conventional device of this kind, as shown in FIG. 1, includes a fuel hydrogen generator 17 having a structure shown in FIG. 2, which will be described later;
A fuel cell 18 equipped with an anode electrode 19 and a cathode electrode 22 operates in response to supply of hydrogen-containing reformed gas generated in the device, and waste gas discharged from the fuel hydrogen generator 17 (fuel hydrogen generator 17 The waste gas turbine 2o rotates based on the heat source of the reforming reaction (used waste gas), and the recovery power of the collapsed gas turbine 2o drives the waste gas turbine 2o, and the air is used as fuel for the hydrogen generator 17 (for combustion). and a compressor 21 for supplying to the cathode 22 of the fuel cell 18, a chimney 23 for discharging the waste gas that has passed through the waste gas turbine 20 and the waste gas that has passed through the cathode 22 out of the system, and from the anode 19. In order to use the discharged waste gas as fuel, it is composed of a line 24 for circulating the waste gas to the imitation material quality control device 17 while adding a combustion aid. As shown in FIG. 2, the fuel hydrogen generator 17 described above includes a hollow cylindrical upper head 2 equipped with a supply nozzle l for the reforming reaction raw material and an exhaust nozzle 8 for the generated hydrogen-containing reformed gas; A plurality of reforming reaction inner pipes 5 branch from a collection chamber 7 connected to the discharge nozzle 8 and extend downward into a heating chamber 9 in an open shape, and a space for filling a reforming catalyst 4 is provided on the outside of the inner pipe. A reforming reaction outer tube 3 whose upper part is open to the upper head 2 and whose lower part is sealed by a bend-shaped part 6, and a ceramic tray 1 below the heating chamber 9 are provided.
It consists of a mixing chamber 11 for fuel and oxygen-containing gas (air) and a catalyst-filled combustion chamber 10, which are provided in sequence upward (in the gas flow direction) via the fuel cell 4. In addition, in Figure 2, 1
Nozzles 2 and 13 supply fuel and air to the mixing chamber 11, respectively, and nozzle 16 discharges combustion gas led to the heating chamber 9.

In an apparatus having such a configuration, light hydrocarbons, such as LNG and steam, which are raw materials for the reforming reaction, are supplied to the supply nozzle 1.
is introduced into the upper head 2, and then passed through the upper opening of the reforming reaction tube 3 to 40 layers of reforming catalyst filled in the reaction tube, during which time it is indirectly heated by high-temperature combustion gas. The reforming reaction proceeds to produce a hydrogen-containing reformed gas having a composition generally shown in Table 1 below.

Table 1: vol. It rises and reaches the gathering chamber 7, after which it is supplied to the anode electrode 19 of the fuel cell 18 through the discharge nozzle 8, and after being pressurized by a separate compressor 21, it is supplied to the cathode electrode 2.
Along with the air distributed to 2, a predetermined cell reaction (Ih +
1/20x→IhO).

In addition, in this cell reaction, H2 in the supplied reformed gas
Generally, only 80 to 85 sections are consumed, so
The residual H2-containing waste gas from the anode is recirculated to the fuel hydrogen generator 17 via line 24 and used as fuel during combustion as described below.

On the other hand, the combustion of the tank that supplies the heat source for the reforming reaction is performed as follows. That is, an auxiliary fuel such as LNG is added to the waste gas from the anode that is recirculated as described above, and this and the air that is pressurized by the compressor 21 and sent separately are introduced into the mixing chamber 11 through the nozzles 12 and 13, respectively. he,
Then, after passing through a ceramic tray 14, it is sent to a combustion chamber 10 filled with a catalyst 15, where it is combusted. The high-temperature combustion gas generated at this time rises and enters the heating chamber 9, is used as a heat source for the reforming reaction, and is then discharged from the nozzle 16.Then, the power is recovered by the waste gas turbine 20, and then from the chimney 23 into the atmosphere. released into the body.

However, in such a fuel cell device, the amount of heat generated during combustion is extremely large, and the temperature of the combustion gas is generally 120°C.
There is a problem that the temperature reaches 0 to 1400°C. this is,
This is due to the addition of high-calorie auxiliary fuel to improve the combustibility of the low-calorie anode exhaust gas, and the use of air with high oxygen intensity as the oxygen-containing gas for combustion. It seems to be. As a result, thermal deterioration and activity reduction of the combustion catalyst occur, making it impossible to use it for long periods of time, and requiring heat resistance for equipment materials.
The lower pend-shaped part of the outer reforming reaction tube, which is susceptible to the effects of high-temperature gases on bamboo, requires membrane-preservation measures such as insulation on the outer surface, which is disadvantageous in terms of equipment design and cost. There are drawbacks. Another drawback is that the waste gas from the cathode, which generally has the temperature, pressure, and composition shown in Table 2 below, is simply dissipated through the chimney, resulting in a large overall reduction in thermal efficiency.

Table 2 An object of the present invention is to provide a fuel cell device capable of lowering the combustion temperature in a combustion section including a catalyst filling section and preferably improving thermal efficiency.

To achieve the above object, the present invention provides a method for reforming (light) hydrocarbons under heating to obtain fuel hydrogen for fuel cells, in which fuel and oxygen-containing hydrogen are sequentially used as a supply part of the heating source. In a fuel cell device equipped with a fuel hydrogen generator provided with a gas mixing chamber and a catalyst-filled combustion chamber, sensible heat of the combustion gas generated in the combustion chamber and residual oxygen are generated downstream of the catalyst-filled combustion chamber. It is characterized by the provision of a reaction chamber in which the newly supplied fuel is combusted.

With the above configuration, the combustion section is divided into parts, and therefore, it is generally sufficient to supply 50 to 60% of the total fuel to the catalyst-filled combustion chamber in the previous stage, so the amount of heat generated is reduced and the combustion The temperature of the gas becomes relatively low. The remaining fuel is then introduced into the reaction chamber in the latter stage, where it comes into contact with the combustion gas generated in the combustion chamber in the previous stage and is slowly combusted under its sensible heat and residual 02, so the combustion gas generated by the combustion temperature is also kept relatively low.

In the present invention, the oxygen-containing gas for combustion supplied to the combustion section may be air as in the conventional case, but it is preferable to use waste gas from the cathode electrode with a low oxygen concentration as listed in Table 2 above. preferable. When this cathode exhaust gas is used, since the O22 content is low, combustion in the combustion section can be made more gradual, thereby making it possible to further lower the temperature of the combustion gas. Moreover, since the heat and pressure retained in the waste gas can be effectively used, the overall thermal efficiency can be improved.

Hereinafter, the present invention will be explained in more detail with reference to embodiments shown in the drawings.

FIG. 3 shows a side cross section of a fuel hydrogen generation device R (17A) for a fuel cell according to an embodiment of the present invention.
2, a reaction chamber 10A provided downstream of the catalyst-filled combustion chamber 1o via a ceramic tray 14A, and a fuel supply to the reaction chamber 10A. The second stage nozzle 12A is mainly configured to supply the water.

In a device with such a configuration, the supplied fuel is 5% of the total fuel.
Fuel and air are introduced into the mixing chamber 11 in the same manner as in the case of Fig. 2, except that the range is 0 to 60 degrees, and then combustion occurs in the combustion chamber 10. Therefore, the temperature of the generated combustion gas also becomes relatively low.

On the other hand, the remaining fuel is supplied to the reaction chamber 10A through the second stage nozzle 12A, contacts the combustion gas, and is combusted under its sensible heat and residual O2. This combustion takes place in the absence of a catalyst, so it is slow, and therefore the temperature of the combustion gas generated is relatively low. Therefore, not only can deterioration of the catalyst be reduced, but also the heat resistance of the device material can be reduced.

Next, FIG. 4 shows the fuel hydrogen generator 17A shown in FIG.
This shows a system of a fuel cell device according to another embodiment of the present invention, which is constructed by incorporating A line 25 for guiding the extremely waste gas to the oxygen-containing gas supply nozzle 13 of the fuel hydrogen generator 17A is branched from an anode extremely waste gas circulation line 24, and a part of the waste gas is sent to the fuel hydrogen generator 17A. A second stage nozzle 1 provided
It mainly consists of a circulation branch line 26 for leading to 2A. Note that this device includes a line and a compressor 21 for guiding extremely high cathode gas to the chimney 23, as shown in FIG.
A fuel hydrogen generator 17 branched from an air line connected to
The line that reaches it is also omitted.

In an apparatus with such a configuration, the cathode waste gas is supplied to the mixing chamber 11 (see Fig. 2) of the fuel hydrogen generator ti7A after passing through the line 25, and this gas is supplied from the above-mentioned Table 2. As is clear, since 02fil Me is low, the combustion in the combustion chamber is more gradual than in the above embodiments, and the temperature of the combustion gas is accordingly low, generally about 700-950''C. Furthermore, for the same reason, combustion in the reaction chamber provided downstream of the combustion chamber becomes even more gradual, and the temperature of the combustion gas is generally 100°C.
Since the temperature is about 0 to 1100°C, the low temperature effect of the above embodiment is further promoted. In addition, in this embodiment, the heat and pressure retained in the cathode waste gas can be effectively used, so the overall thermal efficiency can be improved.

As described above, according to the present invention, the fuel is newly supplied to the wake of the catalyst-filled combustion chamber that constitutes a part of the fuel hydrogen generator by combining the sensible heat of the combustion gas generated in the combustion chamber and the residual oxygen. In addition to providing a reaction chamber in which combustion occurs, it is preferable to use waste gas with a low oxygen concentration discharged from the cathode electrode of the fuel cell as the oxygen-containing gas for combustion during the above-mentioned sintering, thereby achieving a high combustion characteristic range. Combustion in a catalyst-filled combustion chamber takes place with a small amount of fuel supplied in portions and a low oxygen concentration;
In addition, the subsequent combustion of the remaining fuel takes place in a chamber with low combustion characteristics, which slows down the combustion process.As a result, the combustion temperature is lowered, making it possible to prevent thermal deterioration of the catalyst and reduce the heat resistance of equipment materials. becomes.

Furthermore, since the heat and pressure retained in the cathode waste gas can be effectively used, the overall thermal efficiency can also be improved.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of a conventional fuel cell device, FIG. 2 is a side cross-sectional view of a fuel hydrogen generator that constitutes a part of the conventional fuel cell device, and FIG. 3 is a diagram showing an embodiment of the present invention. 4th sectional side view of the fuel hydrogen generating device constituting a part of the fuel cell device;
The figure is a system diagram of a fuel cell device according to another embodiment of the present invention. 1... Raw material supply nozzle, 3... Reforming reaction outer tube, 4...
... u2.5 before reforming... Reforming reaction inner tube, 6... Bend-shaped body, 8... Reformed gas discharge nozzle, 9... Heating chamber, 10... Catalyst filling combustion chamber, 10A...reaction chamber,
11... Mixing chamber, 12... Fuel supply nozzle, 12 people... Second stage (fuel supply) nozzle, 13... Air (oxygen-containing gas) supply nozzle, 14.14A- Ceramic tray, 15... (combustion) catalyst, 16... combustion gas discharge nozzle, 17.17A... fuel hydrogen generator,
18...Fuel cell, 19...Anode electrode, 20...
・Waste gas turbine, 21... Compressor, 22...
- Cathode electrode, 24... Anode waste gas circulation line, 25... Cathode waste gas supply line, 26...
Anode waste gas circulation branch line. Agent Patent Attorney Takeshi Kawakita 2nd Kun 1

Claims (3)

[Claims] (1) In order to obtain hydrogen fuel for fuel cells by reforming hydrocarbons under heating, as a supply part of the heating source,
In the fuel cell device 1, which is equipped with a fuel hydrogen generator equipped with a mixing chamber for twisted and oxygen-containing gas and a catalyst-filled combustion section, combustion gas generated in the combustion chamber is located downstream of the catalyst-filled combustion section. A fuel cell device characterized by being provided with a reaction chamber that burns heat, residual oxygen, and fuel newly supplied from a trap. (2) /I? In claim 1, the fuel supplied to the mixing chamber and the reaction chamber are both waste gases discharged from the anode electrode of the fuel cell.
This is a fuel cell device. (3)/I'ff In claim M1, at least a part of the oxygen-containing gas supplied to the mixing chamber is waste gas discharged from the cathode of the fuel cell Oki 1.