JPH07138001A - Vaporizer for fuel-reforming apparatus - Google Patents

Abstract

PURPOSE:To provide a vaporizer for a fuel-reforming apparatus excellent in efficiency of heat exchange between hot air and a liquid fuel and having a long service life and improve the reforming efficiency of the fuel-reforming apparatus. CONSTITUTION:In this fuel-reforming apparatus 1, a fuel pipeline 20 where a liquid fuel is allowed to pass is set in an outer cylinder 11 where hot air (X) is allowed to pass. The fuel pipeline 20 has a coiled-shape in which mutually adjacent fuel pipes are close to each other and the whole body has a cylindrical shape 21 along the inside wall of the outer cylinder 11. The cylindrical body 21 is equipped with the first partition plate 13 having a shape capable of clogging a gap between the cylindrical body 21 and the outer cylinder 11 along the inside wall of the outer cylinder 11 in the neighborhood of the hot air inlet side end. This cylindrical body 21 is also equipped with the second partition plate 12 having a shape capable of closing the opening part of the cylindrical body 21 in the neighborhood of the hot air outlet side end.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vaporizer for a fuel reformer, and more particularly to improvement of a fuel line.

[0002]

2. Description of the Related Art A fuel reformer is a device for reforming a liquid fuel such as natural gas, methanol or naphtha to obtain a hydrogen-rich reformed fuel. The reformed fuel obtained is a fuel for a fuel cell. Used as. The structure of the fuel reformer differs depending on the type of fuel and the scale of processing, but in the case of a fuel cell reformer that uses methanol fuel, generally, as shown in FIG. 2, a burner 104 for heating air, a vaporizer 110 for heating and vaporizing liquid fuel by heated air are housed, and a plurality of reformers 130 having a catalyst layer are arranged around the burner 104.

In such a fuel reformer, the mechanism of reforming the liquid fuel is such that the liquid fuel such as hydrous methanol is first introduced into the vaporizer 110, while the burner 1 is used.
The heated air heated in 04 passes through the heat insulating cylinder 111 of the vaporizer 110 and supplies heat to the liquid fuel. The liquid fuel is vaporized by the heat received to become vaporized fuel, is discharged from the vaporizer 110, is then sent to the reformers 130 through the branch pipe 140, and passes through the catalyst layer in the reformer 130. . On the other hand, the heated air that has passed around the vaporizer 110 heats the reformer 130 with residual heat while passing around the reformers 130 .... In the reformer 130, the vaporized fuel causes a chemical reaction (reforming reaction), and hydrogen-rich fuel gas is generated.

In such a conventional vaporizer 110, a vaporizing cylindrical tube 121 is mainly used for heat exchange.
That is, the heated air passes between the inside and outside surfaces 126 of the inner side surface 127 and the heat insulating cylinder 111, and the liquid fuel passes through the cylindrical conduit 1 sandwiched between the outside surface 126 and the inner side surface 127.
It goes down 28. A ring-shaped or spiral (ring-shaped in the figure) metal heat transfer member 129 made of copper or the like is placed in the cylindrical pipe path 128 in order to improve heat exchange efficiency. Road 1
The liquid fuel in 28 receives heat while flowing through the metal heat transfer member 129.

[0005]

A conventional carburetor 110 is used.
Has been devised to improve the efficiency of heat exchange, as described above, but the heated air flows through the gap between the outer surface 126 and the heat insulating cylinder 111, and the conduit surrounded by the inner surface 127. Since it passes straightly, a part of the heated air passing therethrough passes without coming into contact with the outer side surface 126 or the inner side surface 127, and also the heat insulating cylinder 111 from the heated air.
There is also a problem that heat of the heated air is released from the vaporizer 110 without being sufficiently utilized for vaporizing the liquid fuel.

In order to improve the reforming reaction,
Since the temperature of the vaporized fuel entering the reformer 130 must be high to some extent, if the heat loss in the vaporizer is large as described above, combustion in the burner must be increased to compensate for it, resulting in The loss of fuel was increasing. For example, when such a fuel reformer is used in a fuel cell, normally, the remaining exhaust gas used in the fuel cell as reformed fuel is used as the fuel for the burner. Only about 40% of the fuel can be used in the fuel cell, and the rest is used for combustion in the burner.

Further, as described above, when a ring-shaped metal heat transfer body is used in the vaporizer for a fuel reformer, since the ring-shaped metal heat transfer bodies are stacked in large numbers, the apparatus is repeated. There was also a problem that cracks are likely to occur during use as a result, that is, deterioration of the vaporizer for the fuel reformer. In view of the above problems, the present invention provides a vaporizer for a fuel reformer, which has high efficiency of heat exchange between heated air and liquid fuel, and also has excellent durability, and improves the reforming efficiency of the fuel reformer. The purpose is to let.

[0008]

In order to solve the above problems, the present invention is for a fuel reformer in which a fuel pipe through which liquid fuel passes is installed in an outer cylinder through which heated air passes. In the carburetor, the fuel pipeline is a coil shape in which adjacent fuel pipelines are adjacent to each other, and is a fuel pipeline that entirely forms a tubular body along the inner wall of the outer cylinder, and the heating of the tubular body is performed. A first partition plate having a shape that closes the gap between the cylinder and the outer cylinder is provided near the end on the air inlet side along the inner wall of the outer cylinder, and near the end on the heated air outlet side of the cylinder, Second shape that closes the mouth of the cylinder
It is characterized by including a partition plate.

[0009]

In the carburetor for a fuel reformer having the above-described structure, the entire fuel pipe line through which the liquid fuel passes forms a cylinder along the inner wall of the outer cylinder, so that the heating air passing through the outer cylinder is heated. Flows in a direction passing through this cylinder. The first partition plate provided near the end of the tubular body on the heated air inlet side has a shape that closes the gap between the tubular body and the outer barrel along the inner wall of the outer barrel.
The flow of the heated air is regulated by the first partition plate and flows so as to enter the inside of the cylindrical body. Further, since the second partition plate provided near the end on the heated air outlet side of the tubular body has a shape that closes the mouth of the tubular body, the heated air that has entered the inside of the tubular body remains inside the tubular body. You can't get out.

Since the fuel pipe has a coil shape, the heated air that has entered the inside of the cylinder passes through the gap between the fuel pipe and the fuel pipe and escapes to the outside of the cylinder. It will be. Since the adjacent fuel pipes are close to each other, the heated air comes into contact with the fuel pipes when passing through the gap between the fuel pipes. Therefore, while the heated air passes through the tubular body, it always comes into contact with the fuel pipeline, and heat exchange is effectively performed. Further, since the heated air does not come into contact with the outer cylinder before passing through the gap while the heated air passes through the cylindrical body, heat loss to the outer cylinder can be prevented.

Further, since the fuel pipeline is a coil-shaped pipeline, it can be formed by winding a single pipe, and a ring-shaped or spiral-shaped metal heat transfer body having a problem of durability is formed. No need to use.

[0012]

【Example】

(Embodiment) FIG. 1 is a perspective view (partial cross section) of a fuel reformer according to an embodiment of the present invention. This fuel reformer 1
Is for supplying reformed fuel to an external fuel cell (not shown).

The fuel reforming apparatus 1 has a main body housed in a cylindrical outer container 2 made of a heat insulating material, and has a size of, for example, 600 mm in height and 300 mm in diameter.
In the apparatus main body, a cylindrical burner 4 for heating air is installed in the central portion on the bottom surface 3 of the outer container 2, and a cylindrical vaporizer 10 for vaporizing liquid fuel by the heated air is provided by the burner 4
Are installed on the upper part of the carburetor, and four cylindrical reformers 30 ... Reforming vaporized fuel are installed around the carburetor 10.
Branch pipe 40 for branching vaporized fuel from the reformer 30 ...
Is installed above the vaporizer 10.

During steady operation, the burner 4 burns the hydrogen-rich reformed fuel discharged from the fuel reforming apparatus 1 with the remaining fuel exhaust gas used in the external fuel cell, so that the bottom surface 3 is pushed from below. The air blown into the burner 4 from the combustion air pipe 5 penetrating upward and communicating with the burner 4 is heated, and the heated air is blown upward. In addition, during the initial operation, part of the liquid fuel can be supplementarily burned in order to increase the amount of combustion. The heated air thus heated by the burner 4 is blown into the cylindrical vaporizer 10.

The carburetor 10 has a cylindrical heat insulating cylinder 11 which forms an upward passage of the heated air sent from the burner 4.
Is installed on the burner 4, and its insulating cylinder 1
1, a coiled fuel conduit 20 through which liquid fuel passes
Is installed and configured. The fuel line 20 includes a cylindrical tubular main coil portion 21 along the inner wall of the heat insulating cylinder 11.
The spiral portion 22 formed between the main coil portion 21 and the burner 4 and the straight pipe 23 passing vertically through the center of the main coil portion 21 are continuously formed, and the vaporizer 1
The liquid fuel that has entered the fuel conduit 20 from above 0 is vaporized by being heated by the heated air while descending the main coil portion 21, further heated while passing through the spiral portion 22 and rising in the straight pipe 23, Vaporizer 10 as high temperature vaporized fuel
Is discharged from above.

The branch pipe 40 that branches in four directions is a carburetor 1.
The vaporized fuel discharged from the upper part of 0 is evenly divided into 4
One reformer 30 ... Four cylindrical reformer 30
Is a space between the heat insulating cylinder 11 and the side surface of the outer container 2,
It is arranged so as to surround the heat insulating cylinder 11. In the reformer 30, a catalyst layer 31 is formed by packing a reforming catalyst (for example, a commercially available copper / zinc-based methanol reforming catalyst) in a metal cylindrical container. Reformer 3
The lower part of 0 ... penetrates the bottom surface 3 and communicates with the confluence pipe 32,
The merging pipe 32 communicates with an external fuel cell. Therefore,
The vaporized fuel that has entered the upper portion of the reformer 30 from the branch pipe 40 causes a reforming reaction while descending in the catalyst layers 31 to become reformed fuel, which is collected by the confluent pipe 32 and is supplied to an external fuel cell. Sent.

FIG. 2 is a sectional view of the main part of the vaporizer 10.
In the carburetor 10, the fuel conduit 20 is formed of a single stainless steel pipe (outer diameter 9.5 mm), and the main coil portion 21 has an outer diameter 100 mm and a height 1 as shown in FIG.
It is a cylindrical tube of 90 mm, the total length of the coil is about 5 m, the number of coil turns is 18, and the interval between adjacent tubes is 1 mm. Further, at the upper end of the main coil portion 21, a disc-shaped upper partition plate 12 that covers the upper surface of the cylindrical tubular main coil portion 21 is installed,
At the lower end of the main coil portion 21, a donut-shaped lower partition plate 13 that covers the gap between the main coil portion 21 and the heat insulating cylinder 11 is installed.

1 and 2, the arrow X indicates the flow of heated air, and the arrow Y indicates the flow of liquid fuel, vaporized fuel or reformed fuel. As shown in the figure, the heat insulating cylinder 1 has the structure of the vaporizer 10 as described above.
Since the heated air rising inside 1 is prevented from directly flowing into the outer space 24 between the main coil portion 21 and the heat insulating cylinder 11 by the lower partition plate 13 at the lower end of the main coil portion 21. , And flows into the inner space 25 of the main coil portion 21 through the inside of the lower partition plate 13. On the other hand, at the upper end of the main coil portion 21, the upper partition plate 12 is regulated so as not to be able to directly escape upward from the inner space 25. Therefore, the heated air flowing into the inner space 25 of the main coil portion 21 is It passes through the gaps 26 between adjacent stainless steel pipes of the main coil portion 21 and escapes to the outer space 24, and then passes upward between the upper partition plate 12 and the heat insulating cylinder 11. Therefore, the heated air passing through the carburetor 10 is always a pipe in which the liquid fuel flows, and a gap 26 sandwiched between the pipes.
Will pass through. Since the gaps 26 ... Are only 1 mm, when the heated air passes through the gaps 26 ..., the heated air comes into contact with the fuel conduit 20 and efficient heat exchange between the heated air and the liquid fuel is performed.

(Comparative Example) FIG. 3 is a schematic perspective view (partial cross section) showing an example of a conventional fuel reformer. This fuel reforming apparatus 101 has an apparatus main body housed in an outer container 102 similar to the cylindrical outer container 2 of the embodiment, and the apparatus main body is air installed below an upper surface 103 of the outer container 102. A burner 104 for heating, a cylindrical vaporizer 110 installed under the burner 104, a reformer 130 installed around the vaporizer 110, and a branch installed below the vaporizer 110. It is composed of a tube 140.

The burner 104 has the same function as the burner 4 of the embodiment, but takes in air from the upper combustion air pipe 105 and blows heated air downward.
The vaporizer 110 is a heat insulating cylinder 1 that forms a passage for heated air.
11, a vaporization cylindrical tube 121 through which liquid fuel passes,
The spiral portion 122 and the straight pipes 123 and 124 passing vertically through the center of the vaporization cylindrical pipe 121 are formed to communicate with each other, and the upper pipe 125 of the vaporizer 110 is connected to the vaporization cylindrical pipe 1.
The liquid fuel put in 21 goes down the inside of the vaporizing cylindrical pipe 121, rises in the straight pipe 124, passes through the spiral portion 122, and is heated by heated air while descending the straight pipe 123 to become vaporized fuel, It is discharged below the vaporizer 110.

Branch pipe 140, reformer 130 ..., Collecting pipe 1
32 is the branch pipe 140 and the reformer 1 of the above embodiment, respectively.
30 ..., having the same function as the collecting pipe 132,
The vaporized fuel that has flowed out of 0 is supplied from the branch pipe 140 to the reformer 130.
The vaporized fuel that has entered the ... causes a reforming reaction to become reformed fuel, which is collected by the confluence pipe 132 and sent to the external fuel cell.

In the vaporizer 110, the vaporizing cylindrical tube 1
21 has an outer side surface 126 and an inner side surface 127, and a gap between the outer side surface 126 and the heat insulating cylinder 111, and an inner side surface 127.
The heated air passes from top to bottom in a line surrounded by. On the other hand, the liquid fuel that has entered the vaporized cylindrical pipe from the pipe 124 receives heat from the heated air while descending in the cylindrical conduit 128 sandwiched between the outer surface 126 and the inner surface 127. Here, in order to improve the efficiency of heat exchange, a ring-shaped or spiral (ring-shaped in the figure) metal heat transfer member 129 made of copper or the like is stacked in the cylindrical conduit 128. . Since the methanol fuel descending in the cylindrical pipe 128 flows down along the metal heat transfer member 129 in order from the top, it is easy to receive heat from the heated air.

[Experiment] Using the fuel reforming apparatus 1 of the above embodiment and the fuel reforming apparatus 101 of the comparative example, an aqueous methanol solution was reformed under predetermined conditions, and the vaporizer 10 of the embodiment and the comparative example were compared. A test was conducted to compare the heat receiving efficiency of the vaporizer 110. The operating condition of the fuel reformer is that the supply rate of methanol supplied to the vaporizer 10 and the vaporizer 110 is 80 ml / mi.
Further, the heat of combustion of the burner 4 and the burner 104 was set to 44.3 kcal / min. The test results are shown in Table 1.
Shown in.

[0024]

[Table 1]

As can be seen from Table 1, in the fuel reformer 1, the heat receiving efficiency of the liquid fuel, that is, the heat receiving amount of the liquid fuel with respect to the combustion heat quantity of the burner is greatly improved as compared with the fuel reformer 101. It is considered that this is because the vaporizer 10 has improved heat exchange efficiency as compared with the vaporizer 110. In addition, the main reason why the efficiency of heat exchange is improved is that the heated air passing through the vaporizer 10 is
It is considered that this is because the liquid fuel always passes through the narrow gaps 26, and at that time, the liquid fuel comes into contact with the pipe flowing therein.

In the fuel reformer 1 of the above embodiment, the burner 4 is installed in the lower part, but even when the burner 4 is installed in the upper part, the same effect is obtained with respect to the heat receiving efficiency of the carburetor 10. Is obtained. Further, in the above embodiment,
The carburetor 10 has a cylindrical shape and the main coil portion 21 has a cylindrical tubular shape, but the same can be applied to a rectangular vaporizer and a rectangular tube-shaped main coil portion. Further, in the above embodiment, an example in which methanol is used as the liquid fuel has been shown,
Similar effects can be obtained with natural gas, naphtha, and the like.

[0027]

As described above, according to the present invention, it is possible to provide a vaporizer for a fuel reformer, which has a high efficiency of heat exchange between the heated air and the liquid fuel and is also excellent in durability. Since this fuel reformer vaporizer improves the reforming efficiency of the fuel reformer, it is economical because it can save liquid fuel when used in a fuel cell or the like.

[Brief description of drawings]

FIG. 1 is a perspective view (partial cross section) of a fuel reformer according to an embodiment of the present invention.

FIG. 2 is a sectional view of a main part of the vaporizer 10.

FIG. 3 is a schematic perspective view (partial cross section) showing an example of a conventional fuel reformer.

[Explanation of symbols]

 10 Vaporizer 11 Insulating cylinder 12 Upper partition plate 13 Lower partition plate 20 Fuel line 21 Main coil part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masatoshi Ueda 2-5-5 Keihan Hondori, Moriguchi City Sanyo Electric Co., Ltd.

Claims (1)

[Claims] 1. A carburetor for a fuel reformer in which a fuel pipe through which liquid fuel passes is installed in an outer cylinder through which heated air passes, wherein the fuel lines are adjacent fuel pipes. The fuel tubes are coiled so that the passages are in close proximity to each other, and the whole forms a cylinder along the inner wall of the outer cylinder, and in the vicinity of the end on the heated air inlet side of the cylinder, the outer cylinder A first shape that closes the gap between the cylindrical body and the outer cylinder along the inner wall
And a second partition plate having a shape that closes the mouth of the tubular body in the vicinity of the end of the tubular body on the heated air outlet side.