JP7454764B2 - hydrogen generator - Google Patents

Description

TECHNICAL FIELD This disclosure relates to a hydrogen generation device.

Patent Document 1 discloses a hydrogen generator. This hydrogen generator consists of a heating part that burns fuel to produce combustion gas, an inner cylinder placed outside the heating part, and an inner cylinder bottom plate (hereinafter referred to as a bottom mirror plate) that closes the lower opening of the inner cylinder. ), a middle cylinder arranged on the outside of the inner cylinder, a reforming catalyst held in the space formed between the inner cylinder and the middle cylinder, and a reforming catalyst installed in a position facing the heating part of the bottom end plate. It includes a heat insulating material and a fixing part that fixes the heat insulating material.

JP2011-102223A

The present disclosure provides a hydrogen generator that can reliably fix a heat insulating material to a bottom mirror plate without using fixing fittings.

The hydrogen generation device in the present disclosure includes: a heating section that burns fuel to generate combustion exhaust gas; an inner cylinder having a central axis in a substantially vertical direction and disposed outside the heating section so as to surround the heating section; A downwardly convex bottom mirror plate that closes the opening on the lower side of the inner cylinder, a middle cylinder that has a center axis in a substantially vertical direction and is arranged on the outside of the inner cylinder so as to surround the inner cylinder; It includes a reforming catalyst held in a space formed between the inner cylinder and a heat insulating material covering a surface of the bottom end plate facing the heating section.

The lower end of the inner cylinder is shrink-processed so that the joint part with the bottom end plate is substantially flush with the outer peripheral surface, and the inner diameter of the shrink-processed part of the inner cylinder is The end face of the tube shrinking part, which is smaller than the outer diameter of the heat insulating material, comes into contact with the heat insulating material and fixes the heat insulating material to the bottom mirror plate.

In the hydrogen generator according to the present disclosure, the end face of the tube shrinking part serves as a fixing part that constantly presses the heat insulating material from above, so the heat insulating material can be reliably fixed to the bottom mirror plate without using a fixing fitting.

Schematic configuration diagram of a hydrogen generator in Embodiment 1 A schematic diagram explaining the issues discovered at the time of ideation

(Findings, etc. that formed the basis of this disclosure)
At the time the inventors came up with the present disclosure, hydrogen was generated from hydrocarbon fuel such as city gas through a steam reforming reaction, and impurities such as by-product carbon monoxide (CO) were removed. There is a technology that generates hydrogen-rich reformed gas that can be used as fuel gas for fuel cell power generation equipment.

This technology has a reaction tube composed of multiple cylinders whose overall shape is cylindrical, and the reaction tube has a combustor that is a heating section inside, and a combustion tube that forms the outer wall of the combustor. An inner cylinder arranged on the outside of the combustion cylinder, a mirror bottom plate that closes the opening on the lower side of the inner cylinder, a middle cylinder arranged on the outside of the inner cylinder, an outer cylinder arranged on the outside of the middle cylinder, A reforming catalyst filled in an annular space formed between the inner cylinder and the middle cylinder, a CO reduction catalyst and a CO removal catalyst filled in the annular space formed between the middle cylinder and the outer cylinder, It was obtained using a hydrogen generator consisting of:

Further, a heat insulating material was installed on the bottom mirror plate at a position opposing the heating part, and a fixing part for fixing the heat insulating material was provided.

The fixing parts are generally made of metal fittings in order to withstand severe vibrations caused by transportation before the hydrogen generator is installed, and to prevent them from coming off even if exposed to combustion exhaust gas of 800°C or higher during operation of the hydrogen generator. It is necessary to securely attach the metal fittings to the inner cylinder by welding while holding down the insulation material.

However, if the inner cylinder and bottom mirror plate are manufactured as one piece, it will take a long distance to approach the fixed part from the upper opening of the inner cylinder, so it is difficult to securely attach the insulation material to the metal fittings. It was difficult to hold it down and fix it.

Under such circumstances, the inventors designed the bottom end plate of the inner cylinder and the cylinder as separate parts, taking into account the viewpoint of designing a product that achieves low cost and high durability for the hydrogen generator. In order to ensure high durability, the bottom mirror plate was designed to be thicker than the tube, and the tube was designed to be thinner than the bottom mirror plate.

Then, in order to reduce the amount of material used for the bottom panel, the height of the bottom panel was minimized, and instead of minimizing the height of the bottom panel, the idea was to lengthen the length of the tube and connect it by welding. I got it.

FIG. 2 is a schematic diagram illustrating the problems discovered at the time of ideation. The inventors believe that in order to realize this idea, as shown in Figure 2, in the process of welding the bottom mirror plate and the metal fittings, the welding reliability of the welding part B to be welded later must be ensured. In order to prevent this, it is necessary to keep the distance between welded part A and welded part B at least 10 mm on the outer circumferential surface of the inner cylinder, and the height of the bottom mirror plate cannot be minimized; We discovered that there is a problem that the length is wasted, and in order to solve this problem, we have come to form the subject of the present disclosure.

Therefore, the present disclosure makes it possible to separate the bottom end plate of the inner cylinder and the cylinder of the inner cylinder, to lower the height of the bottom end plate as much as possible, and to securely fix the heat insulating material without using a fixing fitting. Provides hydrogen generation equipment.

Hereinafter, embodiments will be described in detail with reference to the drawings. However, more detailed explanation than necessary may be omitted. For example, detailed explanations of well-known matters or redundant explanations of substantially the same configurations may be omitted. This is to avoid making the following description unnecessarily redundant and to facilitate understanding by those skilled in the art.

The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter recited in the claims.

(Embodiment 1)
Embodiment 1 will be described below using FIG. 1.

[1-1. composition]
As shown in FIG. 1, the hydrogen generator 100 includes a heating section 20, an inner cylinder 21, a bottom mirror plate 22,
A middle cylinder 23, a reforming catalyst 24, a heat insulating material 25, a tube shrinking part 26, an outer cylinder 27, a water supply part 28, a raw material supply part 29, an evaporator 30, a CO reduction catalyst 31, and , a CO removal catalyst 32, an outlet pipe 33, an exhaust gas outlet pipe 34, and a reforming catalyst temperature detection section 35.

The heating unit 20 is a combustor that burns fuel to generate combustion exhaust gas, and is arranged at the center of the hydrogen generator 100. The inner cylinder 21 has a central axis in a substantially vertical direction, and is arranged outside the heating section 20 so as to surround the heating section 20 . The bottom mirror plate 22 has a downwardly convex shape and is arranged so as to close the lower opening of the inner tube 21 . The middle cylinder 23 has a center axis in a substantially vertical direction, and is arranged outside the inner cylinder 21 so as to surround the inner cylinder 21.

The reforming catalyst 24 is held in a space formed between the inner cylinder 21 and the middle cylinder 23. The heat insulating material 25 covers the surface of the bottom mirror plate 22 that faces the heating section 20 . The outer cylinder 27 has a center axis in a substantially vertical direction, and is arranged outside the middle cylinder 23 so as to surround the middle cylinder 23.

The water supply unit 28 is configured to supply water to an upstream portion between the inner cylinder 21 and the middle cylinder 23. The raw material supply section 29 is configured to supply raw materials to an upstream portion between the inner cylinder 21 and the middle cylinder 23.

The evaporator 30 has an inner cylinder 21 and a middle cylinder 23 so that after water and raw materials are supplied, heat from the inner cylinder 21 heated by the heating section 20 generates a mixed gas of water and raw materials. It is composed between

The CO reduction catalyst 31 is held in a space formed between the inner cylinder 23 and the outer cylinder 27 in order to reduce CO in the reformed gas reacted by the reforming catalyst 24.

The CO removal catalyst 32 is a space formed between the inner cylinder 23 and the outer cylinder 27 downstream of the CO reduction catalyst 31 in order to further reduce the CO concentration in the converted gas reacted with the CO reduction catalyst 31. is maintained.

The outlet pipe 33 is configured to communicate with the space between the middle cylinder 23 and the outer cylinder 27 at the upper part of the outer cylinder 27 so that the gas after CO removal reacted with the CO removal catalyst 32 can be discharged to the outside. ing.

The exhaust gas outlet pipe 34 is connected to the upper part of the hydrogen generator 100 and communicates with the space between the heating section 20 and the inner cylinder 21 so that the combustion exhaust gas generated by burning fuel in the heating section 20 can be discharged to the outside. is configured to do so.

The reforming catalyst temperature detection unit 35 detects that the reformed gas reacted at the reforming catalyst 24 is transferred from the flow path between the inner cylinder 21 and the middle cylinder 23 to the middle cylinder 23 and the outer cylinder 27 below the bottom end plate 22. It is configured to detect the representative temperature of the reforming catalyst 24 at the portion that moves to the flow path between.

The lower end of the inner tube 21 is reduced so that the joint portion with the bottom mirror plate 22 is substantially flush with the outer peripheral surface. Further, the inner diameter of the tube-shrinking portion 26 of the inner cylinder 21 is smaller than the outer diameter of the heat insulating material 25.

Then, the end face of the tube shrinking portion 26 comes into contact with the heat insulating material 25, thereby fixing the heat insulating material 25 to the bottom mirror plate 22.

[1-2. motion]
The operation and effects of the hydrogen generator 100 configured as above will be described below.

In order to obtain the amount of hydrogen required by the hydrogen generator 100, city gas is supplied from the raw material supply section 29 and water from the water supply section 28, respectively, to the evaporator 30 between the inner cylinder 21 and the middle cylinder 23. .

At this time, the city gas and water are supplied to the evaporator 30 so that the amount of water vapor is approximately 3 moles per 1 mole of carbon atoms in the average molecular formula of the city gas. The supplied water is evaporated into water vapor in the evaporator 30 and mixed with city gas.

The mixed gas of city gas and steam is supplied to the reforming catalyst 24 section, and by the action of the reforming catalyst 24, a steam reforming reaction is performed and becomes reformed gas. The reformed gas discharged from the reforming catalyst 24 part is supplied to the CO reduction catalyst 31 part, and due to the action of the CO reduction catalyst 31, the CO in the reformed gas and water vapor react, and the CO concentration in the reformed gas is reduced. is reduced to about 0.1 to 0.2%.

The reformed gas whose CO concentration has been reduced by the CO reduction catalyst 31 is further supplied to the CO removal catalyst 32 section, and by the action of the CO removal catalyst 32, CO is removed to a CO concentration of several ppm. It is discharged to the outside.

The combustion exhaust gas discharged from the heating section 20, which is a combustor, is discharged toward the bottom plate 22, then turned around near the bottom plate 22, heats the reforming catalyst 24 through the inner cylinder 21, and is heated to the evaporator. After exchanging heat with the exhaust gas 30, the exhaust gas is discharged from the exhaust gas outlet pipe 34.

Since the bottom mirror plate 22 is directly exposed to high-temperature combustion exhaust gas, the material is made thicker than the inner cylinder 21 to maintain high-temperature strength, and a heat insulating material 25 is provided to suppress the temperature rise of the bottom mirror plate 22. In addition, by adjusting the thickness of the heat insulating material 25, the temperature of the reforming catalyst 24 and the temperature of the reforming catalyst temperature detection section 35 are made to be approximately the same, so that the temperature of the reforming catalyst temperature detection section 35 detects the temperature of the reforming catalyst 24. temperature is being detected.

The inner diameter of the tube shrinking portion 26 is smaller than the outer diameter of the heat insulating material 25, and the end face of the tube shrinking portion 26 is brought into contact with the heat insulating material 25, thereby fixing the heat insulating material 25 to the bottom mirror plate 22.

The bottom mirror plate 22 and the inner cylinder 21 are each composed of separate parts.The bottom mirror plate 22 has excellent high-temperature strength and is thicker than the inner cylinder 21 to ensure high durability. It is constructed with a thin wall compared to the .

The bottom mirror plate 22 and the inner cylinder 21 are joined by welding.

[1-3. Effects, etc.]
As described above, in the present embodiment, the hydrogen generator 100 includes the heating section 20, the inner cylinder 21, the bottom mirror plate 22, the middle cylinder 23, the reforming catalyst 24, and the heat insulating material 25. ing.

The heating unit 20 is configured to burn fuel and generate combustion exhaust gas. The inner cylinder 21 has a center axis in a substantially vertical direction, and is arranged outside the heating section 20 so as to surround the heating section 20 . The bottom mirror plate 22 has a downwardly convex shape and is configured to close the opening on the lower side of the inner tube 21. The middle cylinder 23 has a center axis in a substantially vertical direction, and is arranged outside the inner cylinder 21 so as to surround the inner cylinder 21. The reforming catalyst 24 is held in a space formed between the inner cylinder 21 and the middle cylinder 23. The heat insulating material 25 covers the surface of the bottom mirror plate 22 that faces the heating section 20 .

The lower end of the inner tube 21 is reduced so that the joint portion with the bottom mirror plate 22 is substantially flush with the outer peripheral surface. Further, the inner diameter of the tube-shrinking portion 26 in the inner cylinder 21 is the same as that of the heat insulating material 2.
It is smaller than the outer diameter of 5.

The end face of the shrinking section 26 abuts against the insulation material 25, fixing the insulation material 25 to the bottom plate 22.

Thereby, the end face of the tube shrinking portion 26 can form a fixing portion that constantly presses the heat insulating material 25 from above. Therefore, the heat insulating material 25 can be reliably fixed to the bottom mirror plate 22 without using a separate fixing fitting.

As in the present embodiment, in the hydrogen generator 100, the thickness of the inner cylinder 21 may be made thinner than the thickness of the bottom mirror plate 22.

Thereby, only the bottom mirror plate 22 that requires high temperature strength can be made thicker, and the inner cylinder 21, which does not require higher temperature strength than the bottom mirror plate 22, can be made thinner than the bottom mirror plate 22. Therefore, it is possible to realize an inexpensive hydrogen generating device 100 without spending more material costs on the inner cylinder 21 than necessary.

As in this embodiment, in the hydrogen generator 100, the inner cylinder 21 and the bottom mirror plate 22 may be joined by welding.

As a result, even if the hydrogen generator 100 is subjected to vibration during transportation, the contact portion between the inner cylinder 21 and the bottom end plate 22 will not come off, and the exhaust gas flowing inside the inner cylinder 21 and the bottom end plate 22 will not come off. It is possible to reliably seal the reformed gas flowing outside the inner cylinder 21 and the bottom end plate 22 so that they do not mix with each other.

Note that the above-described embodiments are for illustrating the technology of the present disclosure, and therefore various changes, substitutions, additions, omissions, etc. can be made within the scope of the claims or equivalents thereof.

The present disclosure can be applied to a container by fixing the heat insulating material to the bottom surface of the end plate without using a fixing metal fitting. Specifically, the present disclosure is applicable to hydrogen generators, general pressure containers having end plates, and the like.

20 Heating part 21 Inner cylinder 22 Bottom end plate 23 Middle cylinder 24 Reforming catalyst 25 Heat insulating material 26 Pipe shrinking part 27 Outer cylinder 28 Water supply part 29 Raw material supply part 30 Evaporator 31 CO reduction catalyst 32 CO removal catalyst 33 Outlet piping 34 Exhaust gas outlet piping 35 Reforming catalyst temperature detection section 100 Hydrogen generator

Claims (3)

a heating section that burns fuel to generate combustion exhaust gas;
an inner cylinder having a central axis in a substantially vertical direction and disposed outside the heating unit so as to surround the heating unit;
a downwardly convex bottom mirror plate that closes a lower opening of the inner cylinder;
a middle cylinder having a central axis in a substantially vertical direction and disposed outside the inner cylinder so as to surround the inner cylinder;
a reforming catalyst held in a space formed between the inner cylinder and the middle cylinder;
A hydrogen generator comprising: a heat insulating material covering a surface of the bottom mirror plate facing the heating section,
The lower end of the inner cylinder is reduced so that the joint part with the bottom end plate is substantially flush with the outer peripheral surface side,
The inner diameter of the tube shrinking processed portion of the inner cylinder is smaller than the outer diameter of the heat insulating material,
A hydrogen generating device, wherein an end face of the tube shrinking part contacts the heat insulating material to fix the heat insulating material to the bottom mirror plate. The hydrogen generator according to claim 1, wherein the inner cylinder has a thickness thinner than the bottom mirror plate. The hydrogen generator according to claim 1 or 2, wherein the inner cylinder and the bottom mirror plate are joined by welding.

Images