JP2000026101A - Apparatus for reforming fuel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the apparatus for reforming fuel, having a long operation life and easy to control the temp., in which the difference of temp. in the peripheral direction of a tube-like reforming pipe is suppressed low. SOLUTION: The apparatus for reforming fuel is equipped with a reforming pipe 1 having a catalyst layer 5 between an inner tube body 11 and an intermediate tube body 12 and a combustion tube body 8 which is installed on the inside of the reforming pipe 1 while providing a space between the combustion tube body 8 and the reforming pipe 1. A heat medium generated from a burner provided at the center part is passed through the inside of the combustion tube body 8 and introduced in an annular space between the inner tube body 11 and the combustion tube body 8. The heat medium is further passed through the annular space in order to heat the catalyst layer 5. In the annular space between the inner tube body 11 and the combustion tube body 8, a spiral blade 20 is provided, which is formed by winding a rod-like member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel in which a hydrocarbon-based raw fuel is passed through a reforming pipe, and the raw fuel is steam-reformed by a granular reforming catalyst to reform hydrogen-rich reformed gas. The present invention relates to a fuel reformer used for producing a fuel gas for a battery power generator or the like, and relates to a configuration in which transfer of heat between a heat medium and a raw material gas is improved.

[0002]

2. Description of the Related Art As a fuel reformer of this type, steam is added to a hydrocarbon-based raw fuel such as natural gas or naphtha, and reformed by a granular reforming catalyst while heating with a heat medium to produce hydrogen. A fuel reformer that generates a rich reformed gas and supplies the reformed gas to a fuel cell via a carbon monoxide converter, etc. It is disclosed in Japanese Patent Application Laid-Open No. 3-97602, and an improved version of this is filed in Japanese Patent Application No. 10-34778.

FIG. 4 is a longitudinal sectional view showing a typical configuration example of a conventional fuel reformer filed in Japanese Patent Application No. 10-34778, and FIG. 5 is a fuel reformer shown in FIG. It is a cross-sectional view in the BB plane. As shown in FIG. 4, the present fuel reformer has a reforming tube 1 configured by using three cylindrical bodies.
It comprises a burner 2 arranged inside the reforming tube 1 and a heat insulating layer 4 covering the outside and the lower part of the reforming tube 1. The reforming tube 1 made of a metal material includes a cylindrical intermediate cylinder 12 erected in the vertical direction, an inner cylinder 11 concentrically disposed inside the intermediate cylinder 12, and a concentric outer cylinder 11 outside the intermediate cylinder 12. It consists of three cylinders of the arranged outer cylinder 13, and the upper end of the inner cylinder 11 and the upper end of the outer cylinder 13 are both joined to the upper side surface of the intermediate cylinder 12, and the upper end of the intermediate cylinder 12 is It is joined to the plate 14. Also, of these three cylindrical bodies, the lower end of the inner cylindrical body 11 and the lower end of the outer cylindrical body 13 are disc-shaped bottom plates 15.
The lower end of the intermediate cylindrical body 12 is
From a predetermined gap.

An annular inner tank formed between the intermediate cylinder 12 and the inner cylinder 11 is provided with a catalyst layer 5 filled with a granular reforming catalyst used for reforming a raw material gas. A wire mesh 6A for preventing scattering of the particulate reforming catalyst is provided at an upper end of the catalyst layer 5, and an outflow of the particulate reforming catalyst is provided in a gap between the lower end of the intermediate cylindrical body 12 below the catalyst layer 5 and the bottom plate 15. A wire mesh 6B for prevention is provided. In order to effectively heat the catalyst layer 5, as shown in FIG.
A large number of heat transfer fins 16 extending in the vertical direction are joined to the outer peripheral portion of the inner cylindrical body 11 that is in contact with the inner cylindrical body 11 by welding or the like.

A supply port for introducing a raw material gas is provided on an upper side surface of the intermediate cylindrical body 12, and an outlet for taking out a reformed gas obtained by reforming the raw material gas is provided on an upper side surface of the outer cylindrical body 13. Is provided. The raw material gas introduced from the above supply port flows downward through the annular inner tank formed between the intermediate cylindrical body 12 and the inner cylindrical body 11, passes through the wire mesh 6A, and reaches the catalyst layer 5. Is reformed by flowing through the inside of the catalyst layer 5.
The obtained reformed gas passes through the wire mesh 6B at the lower end, enters an annular outer tank formed between the intermediate cylinder 12 and the outer cylinder 13, and is taken out from the above-mentioned outlet.

[0006] Between the inner cylinder 11 of the reforming tube 1, the furnace vessel 3 and the burner 2, a combustion cylinder 12 provided with a heat insulating layer 7 and a heat insulating material 9 on the inner side surface is concentric, and a bottom plate 15 is formed. It is arranged leaving a gap between them. Inner cylinder 11 and combustion cylinder 12
Is used as a flow path through which the high-temperature heat medium generated by the burner 2 flows, and a heat medium discharge outlet is provided on the uppermost side surface of the inner cylindrical body 11. ing. The heat medium obtained by taking the fuel and the combustion air into the burner 2 and burning it flows down the internal space of the combustion cylinder 12, and then flows from the lower end to the inner cylinder 11 and the combustion cylinder 1.
2 and flows upward through the annular space between them, and heats the catalyst layer 5 incorporated in the reforming tube 1 via the inner cylindrical body 11 and the heat transfer fins 16 to promote the reforming reaction. To contribute.
The heat medium that has passed through this annular space is discharged outside through the heat medium discharge outlet.

In this configuration, a configuration is adopted in which the reformed gas, which has been reformed in the catalyst layer 5 and has become high temperature, flows into the outer space. As shown in Japanese Patent Application No. 10-34778,
Since the catalyst layer 5 is heated not only from the inner side but also from the outer side, heat exchange is performed very efficiently. Further, the temperature difference between the inside and the outside of the catalyst layer 5 does not become excessive, and the reforming reaction is stably and efficiently performed.

When the raw fuel such as natural gas is subjected to steam reforming, the reforming reaction is carried out at an extremely high operating temperature. Therefore, the reforming pipe 1 is entirely made of heat-resistant steel. Further, the heat insulating layer 4 covering the outer periphery of the reforming tube 1 is made of a refractory heat insulating material, suppresses the heat medium generated by the burner 2 from radiating to the outside, and maintains the heat medium at a predetermined temperature. Play a role. The heat-insulating layer 7 disposed near the outlet of the burner 2 on the upper inner wall of the inner cylinder 11 is also made of a refractory heat-insulating material, and serves to prevent damage to the combustion cylinder 12 due to a high-temperature heat medium immediately after generation. Plays.
The heat insulating material 9 is provided for adjusting the amount of heat transfer to the reforming tube 1 and controlling the temperature gradient in the vertical direction.

[0009]

As described above, in a conventional fuel reformer, a combustion cylinder is disposed concentrically inside a reforming pipe composed of a plurality of cylinders, and a combustion cylinder is disposed inside the reforming pipe. The heat medium obtained by the burner is passed through the annular space between the cylinder and the combustion cylinder to heat the catalyst layer filled inside the reforming tube to reform the raw fuel. Although a highly efficient reforming reaction is to be performed, the fuel reformer thus configured still has the following problems.

That is, in this configuration, the heat medium guided into the annular space between the inner cylinder of the reforming tube and the combustion cylinder does not always flow uniformly distributed in the circumferential direction. The deviation of the flow channel width caused by the production error of the operation or the disposition of the heating medium in the circumferential direction due to the provision of a temperature control thermometer (not shown) causes the heating amount of the reforming tube to be uneven, and In addition, there is a risk that the temperature distribution in the circumferential direction of the catalyst layer becomes excessive. In general, the fuel reformer of this configuration is operated while maintaining the temperature at the outlet of the catalyst layer at an average of about 700 ° C.
Approximately 200 between the highest and lowest temperature when measured at
A temperature difference of ° C. was observed. When such a large temperature difference occurs, the installation position of the thermometer used to control the temperature of the catalyst layer cannot be said to be at a typical temperature, and the temperature rise locally becomes excessively large. There is a risk that the life of the member may be reduced, or the reaction temperature may be too low to obtain a predetermined reforming reaction.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned disadvantages of the prior art, and has as its object to adjust the deviation of the flow rate of the heat medium in the annular space between the inner cylinder of the reforming tube and the combustion cylinder. It is an object of the present invention to provide a fuel reformer in which the temperature difference in the circumferential direction of the reforming pipe caused by the above is low, the service life is long and the temperature control is easy.

[0012]

In order to achieve the above object, according to the present invention, there is provided a reforming pipe comprising a plurality of cylindrical bodies arranged concentrically at intervals, and A combustion cylinder disposed at an interval inside the inner cylinder, and a burner disposed in an inner space of the combustion cylinder, a heat medium supplied by the burner is supplied to the inside of the combustion cylinder. After passing through, the space between the combustion cylinder and the inner cylinder of the reforming pipe is passed, and the catalyst layer filled with the granular reforming catalyst provided inside the reforming pipe is heated. And a fuel reformer for reforming the hydrocarbon-based raw fuel introduced into the reforming pipe into a hydrogen-rich reformed gas. A spiral blade is provided in the space, and the heat medium flows in the circumferential direction in a spiral manner while flowing in the circumferential direction.

(2) Further, the above-mentioned reforming tube has an intermediate cylinder disposed at an interval between the outer cylinder and the inner cylinder. Between the inner cylinder and the intermediate cylinder, and then through the space between the intermediate cylinder and the outer cylinder after the introduced raw fuel flows through the space between the inner cylinder and the intermediate cylinder. It is configured to be discharged outside. (3) Further, in the above (1) or (2), the spiral blade is formed from a rod-shaped member spirally wound around the outer periphery of the combustion cylinder.

(4) Alternatively, the spiral blade is formed from a tubular member spirally wound around the outer periphery of a combustion cylinder, and a thermometer used for controlling the heating temperature of the catalyst layer around the tubular member. Shall be inserted. With the configuration as described in the above (1), the heat medium guided to the space between the inner cylinder of the reforming tube and the combustion cylinder causes the annular space to follow the flow path formed by the spiral blades. It flows spirally in the axial direction while flowing in the circumferential direction, and heats the catalyst layer focused inside via the inner cylinder of the reforming tube, so that the catalyst layer is more uniformly heated in the circumferential direction. The temperature difference in the circumferential direction can be kept lower. further,
In the case of (2), the catalyst layer contained in the reforming tube is heated not only from the inside but also from the outside, so that heat is efficiently exchanged.

[0015] Further, according to the above (3) or (4), a spiral blade having a predetermined function can be easily formed. In particular, if the spiral blade is formed of a tubular member as in (4) and a thermometer used for controlling the heating temperature of the catalyst layer is inserted therein, the flow of the heat medium is not affected. Since a thermometer is provided,
This is effective for keeping the temperature difference in the circumferential direction low.

[0016]

FIG. 1 is a longitudinal sectional view showing the basic structure of a first embodiment of a fuel reformer according to the present invention. FIG. 2 is a cross-sectional view taken along the line AA of the fuel reformer of FIG. 1 and 2, components having the same functions as those of the conventional fuel reformer shown in FIGS. 4 and 5 are denoted by the same reference numerals, and description thereof will be omitted.

The difference between this embodiment and the conventional example is that the combustion cylinder 8
A spiral member 20 is formed in an annular space between the inner cylinder 11 and the combustion cylinder 8 by winding a rod-shaped member around the outer periphery of the cylinder, and the heat medium guided to this annular space flows in the circumferential direction. While it is configured to flow spirally from below to above. In this configuration, the catalyst layer accommodated in the reforming tube 1 is heated via the inner cylindrical body 11 by the helically flowing heat medium, so that the temperature distribution in the circumferential direction of the catalyst layer is more uniform than before. It will be.

As shown in FIG. 2, four spiral blades 20 are formed in an annular space between the inner cylinder 11 and the combustion cylinder 8, and the flow of the heat medium is divided into four streams to form a ring. In a fuel reformer configured to spirally flow through a space, thermometers were installed at eight locations on the periphery of the outlet portion of the catalyst layer and measured according to the experimental results of the present inventors. The difference between the highest temperature and the lowest temperature was about 100 ° C. This temperature value is about half the value of the conventional fuel reformer, and the temperature control of the catalyst layer 5 can be performed more safely and stably.

In the illustrated embodiment, four spiral blades 20 are formed in the annular space between the inner cylinder 11 and the combustion cylinder 8, but the number of spiral blades 20 is four. The present invention is not limited to this, and may be appropriately selected according to the size and shape of the annular space. Further, in the embodiment, the spiral blade 20 is formed by a rod member having a substantially circular cross section. However, the spiral blade 20 may be formed by using a bar member having a flat or square cross section. It is clear when considering the function.

<Embodiment 2> FIG. 3 is a longitudinal sectional view showing the basic structure of a second embodiment of the fuel reformer of the present invention. The feature of this embodiment is that the spiral blade 21 disposed in the annular space between the inner cylinder 11 and the combustion cylinder 8 is formed by a tubular member, and furthermore, the catalyst is provided inside the spiral blade 21. Layer 5
The thermometer 22 used for the temperature control is inserted, and the spiral blade 21 also has the function of the protective tube of the thermometer 22.

In this configuration, the flow of the heat medium is made more uniform by the action of the spiral blades 21 as in the first embodiment, and the variation in the temperature of the catalyst layer 5 heated by the heat medium is suppressed to a low level. . Further, since the thermometer 22 for temperature control is inserted in the spiral blade 21 in advance, it is possible to accurately measure the surface temperature of the inner cylinder 11 of the reforming tube 1 without separately installing a thermometer. Temperature control with high reliability.

[0022]

As described above, according to the present invention, since the fuel reformer is configured as described in claim 1, the temperature difference in the circumferential direction of the catalyst layer can be suppressed low, Thus, a fuel reformer that can avoid a significant temperature rise and has a long service life and easy temperature control can be obtained.

Further, according to the second aspect of the present invention, the catalyst layer built in the reforming tube is heated not only from the inside but also from the outside, and heat is exchanged more efficiently. It is suitable as a fuel reformer with easy control. Further, according to the third or fourth aspect, a spiral blade having a predetermined function can be easily formed. In particular, if the spiral blade is formed by inserting a thermometer inside the tubular member formed as described in claim 5, the temperature for controlling the heating temperature can be easily controlled without affecting the flow of the heat medium. Since the meter is provided, it is more suitable as a fuel reformer having a long life and easy temperature control.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a basic configuration of a first embodiment of a fuel reformer of the present invention.

FIG. 2 is a cross-sectional view taken along the line AA of the first embodiment of the fuel reformer of the present invention shown in FIG.

FIG. 3 is a longitudinal sectional view showing a basic configuration of a second embodiment of the fuel reformer of the present invention.

FIG. 4 is a longitudinal sectional view showing a typical configuration example of a conventional fuel reformer.

FIG. 5 is a cross-sectional view of the conventional fuel reformer shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reforming pipe 2 Burner 4 Heat insulation layer 5 Catalyst layer 6a, 6b Wire mesh 7 Heat insulation layer 8 Combustion cylinder 9 Heat insulation material 11 Inner cylinder 12 Intermediate cylinder 13 Outer cylinder 14 Upper plate 15A Bottom plate 16 Heat transfer fin 20 Spiral Blade 21 Spiral blade 22 Thermometer

Claims (5)

[Claims] 1. A reforming pipe comprising a plurality of cylinders arranged concentrically at intervals, and a combustion cylinder arranged at intervals inside an inner cylinder of the reforming pipe. Comprises a burner disposed in the inner space of the combustion cylinder, and after allowing the heat medium supplied by the burner to flow through the inside of the combustion cylinder,
Allow the space between the combustion cylinder and the inner cylinder of the reforming tube to flow,
Fuel reforming that heats the catalyst layer filled with the particulate reforming catalyst provided inside the reforming tube to reform the hydrocarbon-based raw fuel introduced into the reforming tube into a hydrogen-rich reformed gas In the vessel, a spiral blade is provided in a space between the inner cylindrical body and the combustion cylindrical body of the reforming tube, and the heat medium is configured to flow helically in the axial direction while flowing in the circumferential direction. A fuel reformer characterized by the above. 2. The reforming pipe according to claim 1, further comprising an intermediate cylinder disposed at a distance between the outer cylinder and the inner cylinder, and between the inner cylinder and the intermediate cylinder. With the catalyst layer, the introduced raw fuel flows through the space between the inner cylinder and the intermediate cylinder, and then flows through the space between the intermediate cylinder and the outer cylinder to be discharged to the outside. 2. The apparatus according to claim 1, wherein
A fuel reformer according to claim 1. 3. The fuel reformer according to claim 1, wherein the spiral blade is formed by spirally winding a rod-shaped member around an outer periphery of the combustion cylinder. . 4. The fuel reformer according to claim 1, wherein the spiral blade is formed by spirally winding a tubular member around an outer periphery of the combustion cylinder. . 5. The fuel reformer according to claim 4, wherein a thermometer used for controlling a heating temperature of the catalyst layer is inserted in a tube of the spiral blade formed from the tubular member. Porcelain.