KR101216456B1 - Reformer - Google Patents

Abstract

The present invention relates to a fuel conversion device, comprising a cylindrical catalytic combustion unit having an inlet tube and an outlet tube, an inlet tube and an outlet tube, and including a reforming reaction unit and a combustion gas discharge tube configured to surround the outside of the catalytic combustion unit. By including a heating unit configured to cover the outer portion of the reforming reaction unit and a heating source installed at the inner lower end of the reforming unit, the thermal efficiency of the steam reforming type fuel converter used in the small-scale hydrogen fuel cell for power generation, and maximize the thermal independence and fuel reforming The efficiency can be improved.

Description

Fuel converter {REFORMER}

The present invention relates to a fuel conversion device, and in particular, it is possible to obtain heat required for a reforming reaction using catalytic combustion heat and heat of a heat generating source, and maximize the thermal efficiency of the fuel conversion device by constructing a reaction section in which the reforming reaction occurs. The present invention relates to a fuel conversion device and an operating method thereof capable of improving thermal independence and reforming efficiency.

In general, a fuel cell refers to a device for directly converting an energy difference before and after the reaction into electrical energy using an electrochemical reaction between hydrogen and oxygen, without using a combustion (oxidation) reaction of the fuel.

The fuel cell supplies fuel (hydrogen gas or hydrocarbon) to the anode and produces oxygen by supplying oxygen to the cathode, and a typical small scale hydrogen fuel cell system for power generation is shown in FIG. 1.

Referring to the drawings, a typical small-scale hydrogen fuel cell system for power generation includes a fuel cell stack unit 100 including a fuel electrode 110 and an air electrode 120 to generate electrical energy by an electrochemical reaction between hydrogen and oxygen, and a fuel ( Hydrogen gas (H2) is produced from the LNG (1) and oxygen is supplied to the fuel supply unit 200 for supplying the anode 110 of the fuel cell stack 100 and the air electrode 120 of the fuel cell stack 100. The air supply unit 300 to supply, the electrical energy output unit 400 for supplying the electrical energy generated by the fuel cell stack unit 100 to the load, and each of the above-described parts 100, 200, 300, 400 It is composed of a control unit (not shown) for appropriately adjusting.

In this state, when the control unit (not shown) gives an operation command, the fuel 1 passes through the fuel supply unit 200, generates hydrogen gas, is supplied to the anode 110 of the fuel cell stack 100, and the air supply unit ( Air is supplied from the 300 to the cathode 120 of the fuel cell stack 100.

The air supplied from the air supply unit 300 generates electric energy while causing an oxidation reaction and a reduction reaction together with the fuel 1 supplied to the anode 110.

The reformer (reformer) is one of the components constituting the raw material supply unit 200, and generates hydrogen gas from the fuel 1 through the reforming reaction. At this time, since the heat is required for the reforming reaction, a heat source such as a burner is provided in the fuel converter to supply heat to the reaction part.

At this time, since the steam reforming fuel converter in a small-scale power generation hydrogen fuel cell receives heat by relying only on the burner that uses the hydrocarbon raw material as fuel, the overall efficiency of the fuel converter decreases by the amount of hydrocarbon raw material consumed. .

Therefore, there is a need for a fuel converter capable of maximizing thermal efficiency and improving thermal independence and fuel reforming efficiency.

The present invention has been made in view of the above-described problems of the prior art, and maximizes the thermal efficiency of the steam reforming type fuel converter used in a small-scale hydrogen fuel cell for power generation, and can improve thermal independence and fuel reforming efficiency. To provide.

A fuel conversion device according to an aspect of the present invention includes a reforming reaction part and a combustion gas discharge pipe having a cylindrical catalytic combustion part, an inlet pipe, and an discharge pipe having an inlet pipe and an outlet pipe, and configured to surround an outer portion of the catalytic burner. And a heating part configured to surround the outer portion of the reforming reaction part and a heating source installed at an inner lower end of the heating part, wherein the reforming reaction part has a 'H' shape in cross section.

In the fuel conversion device, the steam reforming reaction part may be formed into a cylindrical partition wall so that a passage is formed downward, and thus may be divided into a first reaction part and a second reaction part.

The fuel conversion device may be provided with an input pipe to the upper end of the first reaction unit and a discharge pipe to the upper end of the second reaction unit.

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In the fuel converter, off-gas generated from an anode of a fuel cell stack may be supplied to an inlet pipe of the catalytic combustion unit.

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According to the fuel conversion device of the present invention, it is possible to maximize the thermal efficiency of the steam reforming type fuel conversion device used in the small-scale hydrogen fuel cell for power generation, and to improve thermal independence and fuel reforming efficiency.

The thermally integrated fuel conversion device of the present invention has a structure in which the reforming reaction part is formed of a concentric tube flow path and induces mutual heat exchange between the catalytic combustion part and the heating part and the reforming reaction part, thereby maximizing the heat receiving area and the heat transfer efficiency and being compact. The device can be implemented.

In addition, the thermal independence of the fuel converter can be improved by recovering and using the exhaust gas of the stack anode, and the reforming efficiency of the fuel converter can be improved as the amount of hydrocarbon fuel used is reduced compared to the supply of heat using only the burner. have.

In addition, stable and excellent startability of the fuel cell system can be expected by complementary complementation of two heat sources using catalytic combustion heat as a main heat source and heating source as an auxiliary heat source.

In addition, the combustion gas path at the outermost portion can minimize the heat loss of the entire fuel converter.

1 is a view showing a typical small-scale hydrogen fuel cell system for power generation.
2 is a view showing a fuel conversion device according to a first embodiment of the present invention.
3 is a view showing a fuel conversion device according to a second embodiment of the present invention.
4 is a view showing a fuel conversion device according to a third embodiment of the present invention.
FIG. 5 is a sectional view taken along the AA direction of FIG. 4; FIG.
6 is a flowchart illustrating a method of converting fuel using a fuel conversion device according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings, It will be possible. The present invention is capable of various modifications and various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific disclosure, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a view showing a fuel conversion device according to a first embodiment of the present invention.

Referring to the drawings, the fuel conversion apparatus according to the first embodiment of the present invention includes a catalytic combustion unit 10, a reforming reaction unit 20, a heating unit 30, and a heating source 40.

The catalytic combustion unit 10 is formed in a cylindrical shape having an inlet pipe 11 and an outlet pipe 13 and reforming reaction in the reforming reaction unit 20 to be described later by catalytic combustion of the reaction material flowing from the inlet pipe 11. Supply heat for this to happen.

In detail, the catalytic combustion unit 10 includes an inlet pipe 11 and an outlet pipe 13 through which a space is formed and connects the space and the outside to the inside, and the catalyst 15 is provided in the space. ) Is filled.

In this state, hydrogen gas, which is a reactant, is introduced through the inlet pipe 11, and the introduced hydrogen gas reacts with the catalyst 15 charged in the space to generate heat. The catalytic combustion gas that is a product is discharged through the discharge pipe (13).

At this time, the reactant flowing into the inlet pipe 11 of the catalytic combustion unit 10 is preferably such that the exhaust gas (Off-Gas) generated from the anode 110 of the fuel cell stack 100 is supplied.

Exhaust gas generated from the anode 110 of the stack 100 is generally emitted to the atmosphere, and contains a hydrocarbon fuel of several percent to several ten percent and a hydrogen gas of several to ten percent percent. It is possible to recycle the exhaust gas by catalytic combustion using).

In this case, the inlet pipe 11 and the outlet pipe 13 of the catalytic combustion unit 10 are positioned in opposite directions to allow the combustion reaction by the catalyst 15 to be performed in the entire space inside the catalytic combustion unit 10. It is preferable to.

The reforming reaction unit 20 includes an inlet tube 21 and an outlet tube 23, and is configured to surround the outside of the catalytic combustion unit 10 to supply hydrocarbon fuel and steam supplied to the inlet tube 21. The reformed gas is generated in the discharge pipe 23.

Hydrocarbon fuel is used here, for example, LNG (Liguefied Natural Gas) and the reformed gas discharged is hydrogen gas (H2).

In detail, the reforming reaction unit 20 has a structure that surrounds the outer portion of the catalytic combustion unit 10 with a predetermined space, and the catalyst 25 is filled in the space. In addition, one end of the reforming reaction unit 20 is provided with an inlet tube 21 into which the reforming reactant is introduced, and the other end is provided with a discharge tube 23 through which the product of the reforming reaction is discharged.

As described above, since the reforming reaction unit 20 has a structure surrounding the outer portion of the catalytic combustion unit 10, it is possible to transfer the heat of combustion generated from the catalytic combustion unit 10 to the reforming reaction unit 20 without loss.

The catalyst 15 charged in the space of the reforming reaction unit 20 allows hydrogen to be separated from the hydrocarbon fuel introduced from the inlet tube 21, and the separated hydrogen gas is discharged to the product discharge pipe 23 to provide a fuel cell stack ( 100).

The heating unit 30 includes a combustion gas discharge pipe 33 and is configured to surround the outside of the reforming reaction unit 20, and a heating source 40 is installed at an inner lower end of the heating unit 30. Accordingly, the heat of the heating source 40 is supplied to the reforming reaction unit 20.

In detail, the heating unit 30 has a structure surrounding the outside of the reforming reaction unit 20 with a predetermined space 37 and the space 37 is in an empty state. In addition, both ends of the heating unit 30 is provided with a combustion gas discharge pipe 33.

In addition, a heating source 40 is installed at an inner lower end of the heating part 30, which is a position corresponding to the center of the heating part 30, and the heat generated from the heating source 40 is evenly transmitted to the entire heating part 30. Play a role.

By the structure as described above, the heat generated from the heating source 40 moves along the space 37 of the heating unit 30 to supply heat to the reforming reaction unit 20 and the combustion gas generated at this time is the combustion gas It is discharged through the discharge pipe (33).

The heating source 40 of the heating unit 30 may employ an element capable of supplying heat by heat transfer action such as conduction, convection, and radiation, in addition to, for example, a burner. In addition, the heating unit may be configured without the combustion gas discharge pipe 33 according to the type of the heating source 40.

In the above description, the reforming reaction unit 20 has been described with reference to one layer, but it is preferable to cover the outside of the catalytic combustion unit 10 in multiple layers.

3 is a view showing a fuel conversion device according to a second embodiment of the present invention.

Referring to the drawings, in the fuel conversion apparatus according to the second embodiment of the present invention, the reforming reaction unit 20 includes two layers, and the reforming reaction unit 20 has a cylindrical partition wall so as to form a passage downward. 29) is formed to be divided into a first reaction unit 271 and a second reaction unit (272).

In detail, the reforming reaction unit 20 includes a first reaction unit 271 having a passage structure in contact with the catalytic combustion unit 10, and a heating unit which is divided into the first reaction unit and the partition wall and described later. And a second reaction part 272 which is a passage structure in contact with 30) and a connection part 273 which is a passage structure connecting the first reaction part and the second reaction part.

Here, the first reaction unit 271 refers to a portion of the passage structure in which the catalytic combustion unit 10 can receive heat directly from the catalytic combustion unit 10, and the second reaction unit 272 is the passage structure. It means the portion that can receive heat directly from the heating unit 30 in contact with the heating unit 30 and the connecting portion 273 is a reaction material from the first reaction unit 271 to the second reaction unit 272 It means a part that is open and connected to move.

By the dual structure of the passage structure of the reforming reaction unit 20 as described above, it is possible to lengthen the reaction path causing the reforming reaction, thereby producing more hydrogen gas and easy heat transfer.

At this time, the reactant inlet tube 21 is provided at the upper end of the first reaction unit 271 in contact with the catalytic combustion unit 10, and the product discharge tube 13 is disposed at the upper end of the second reaction unit 272 in contact with the combustion unit. ), The reforming reaction proceeds sequentially through the first reaction part 271 to the second reaction part 272, so that the catalytic combustion part 10 in contact with the first reaction part 271 is the primary source of heat. Can be used as

In addition, the reforming reaction unit 20 is preferably made of a cross-section 'H' shape.

4 is a view showing a fuel conversion device according to a third embodiment of the present invention.

As shown in the figure, when the cross-section of the reforming reaction unit 20 is formed in an 'H' shape, the catalytic combustion unit 10 and the heating unit 30 to be contacted with the reforming reaction unit 20 also have corresponding shapes. Becomes

In this case, the area of the reforming reaction unit 20 in contact with the heating unit 30 is larger than in the second embodiment. Therefore, when the heat of combustion of the catalytic combustion unit 10 is not sufficient for the reforming reaction, the heating source 40 may be operated to supply heat required for the reforming reaction within a short time.

In the above description, the reforming reaction unit 20 has been described on the basis of having a double passage structure. However, even when the reforming reaction unit 20 has a single passage structure, the same effect may be obtained when the cross section of the reforming reaction unit 20 has a 'H' shape. You can get it.

In addition, as shown in FIG. 5, when the partition wall 29 ′ is formed in the radial direction, hydrogen gas may be produced by independently reforming hydrocarbon fuel and water vapor introduced from the plurality of input pipes 21.

Next, a method of producing hydrogen gas using a fuel converter according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

6 is a flowchart illustrating a method of converting fuel using a fuel conversion device according to an embodiment of the present invention.

The following description assumes that the exhaust gas generated from the stack 100 is supplied to the inlet pipe 11 of the combustion catalyst 15, but other gases capable of catalytic combustion may be used.

First, when the fuel cell system is started, the heating source 40 of the fuel converter is operated to supply heat (S601). At this time, the amount of heat supplied from the catalytic combustion section 10 is small.

In order to operate the heating source 40 as described above, in order for the reaction to occur in the reforming reaction unit 20, a temperature of 700 degrees or more needs to be maintained, and at the start-up, sufficient exhaust gas is generated from the stack 100. This is because it is difficult to supply sufficient heat through the catalytic combustion unit 10.

At this time, the hydrocarbon fuel and the water vapor introduced into the reactant inlet tube 21 of the reforming reaction unit 20 sequentially heat the first reaction unit 271 and the second reaction unit 272 while heating the heat from the heating source 40. To be supplied. In addition, hydrogen is separated while reacting with the catalyst 15 charged in the space inside the reforming reaction unit 20, and the generated hydrogen gas is discharged to the product discharge pipe 13.

As the exhaust gas of the stack 100 is supplied a lot, the combustion reaction of the exhaust gas and the catalyst 15 filled in the catalytic combustion unit 10 is activated, so that the temperature of the catalytic combustion unit 10 is maintained at 700 degrees or more. If (S602) the heating source 40 is stopped (S603). Here, the temperature of 700 degrees is a value preset in the control unit (not shown) of the fuel converter as an example.

At this time, the hydrocarbon fuel and the water vapor introduced into the reactant inlet tube 21 of the reforming reaction unit 20 sequentially flow through the first reaction unit 271 and the second reaction unit 272 to heat the catalyst from the catalytic combustion unit 10. To be supplied. In addition, hydrogen is separated while reacting with the catalyst 15 charged in the space inside the reforming reaction unit 20, and the generated hydrogen gas is discharged to the product discharge pipe 13.

 Next, when the temperature of the reforming reaction unit 20 becomes 700 degrees or less (S602), the heating source 40 is restarted to utilize heat using both the heat generated from the heating source 40 and the catalytic combustion unit 10. Supply (S604).

At this time, the hydrocarbon fuel and water vapor introduced into the reactant inlet tube 21 of the reforming reaction unit 20 sequentially flow through the first reaction unit 271 and the second reaction unit 272, and thus the catalytic combustion unit 10 and the heating source. Heat is supplied from 40. In addition, hydrogen is separated while reacting with the catalyst 15 charged in the space inside the reforming reaction unit 20, and the generated hydrogen gas is discharged to the product discharge pipe 13.

In the above description, the catalyst combustion unit 10 and the heating unit 30 are automatically switched to operate, but the catalyst 15 can be operated by manually selecting the combustion and operation of the heating unit 30. Do.

As described above, the heat required for steam reforming of the hydrocarbon raw material is simultaneously or separately obtained by the catalytic combustion unit 10 and the heating unit 30, and the reforming reaction unit 20 in the form of a double concentric tube can be employed to generate hydrogen for small-scale power generation. A thermally integrated fuel converter that can maximize thermal efficiency, improve thermal independence and fuel reforming efficiency of a steam reforming fuel converter used in a fuel cell can be implemented.

In the detailed description of the present invention described above with reference to the preferred embodiments of the present invention, those skilled in the art or those skilled in the art having ordinary skill in the art will be described in the claims to be described later And it will be understood that various modifications and changes of the present invention can be made without departing from the scope of the art.

10: catalytic combustion unit 11: inlet pipe
13: discharge pipe 15: catalyst
20: reforming reaction unit 21: input pipe
23 discharge pipe 25 catalyst
29: partition 30: heating portion
33: combustion gas discharge pipe 37: space
40: heating source
271: first reaction unit 272: second reaction unit
273: connection

Claims (6)

Cylindrical catalytic combustion unit 10 having an inlet pipe 11 and the discharge pipe 13;
A reforming reaction unit (20) having an input pipe (21) and a discharge pipe (23) and configured to surround an outer portion of the catalytic combustion unit (10);
A heating unit 30 having a combustion gas discharge pipe 33 and configured to surround the outside of the reforming reaction unit 20;
Including a heating source 40 installed on the inner bottom of the heating unit 30,
The reforming reaction unit 20, the fuel conversion device, characterized in that the cross section 'H' shape.
The method of claim 1,
The reforming reaction unit (20) is a fuel conversion device, characterized in that the cylindrical partition (29) is formed so that the passage is formed in the lower side is divided into the first reaction unit (271) and the second reaction unit (272).
The method of claim 2,
The fuel conversion device, characterized in that the input pipe 21 is provided at the upper end of the first reaction unit (271) and the discharge pipe (23) is provided at the upper end of the second reaction unit (272).
delete The method of claim 1,
A fuel converter characterized in that the off-gas generated from the anode of the fuel cell stack is supplied to the inlet pipe (11) of the catalytic combustion unit (10).
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