JP6402362B2 - Hydrogen generator and fuel cell system - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a fuel cell power generation apparatus that generates electricity using a hydrocarbon-based raw material, and more specifically, a hydrogen generation apparatus having a hydrodesulfurizer that is contained in the raw material and removes sulfur compounds harmful to the hydrogen generation apparatus. And a fuel cell system including the same.

  In recent years, fuel cell power generation systems that enable highly efficient power generation even with small devices have been developed as power generation systems for distributed energy sources. Hydrogen gas or hydrogen-containing gas used as fuel during power generation has not been developed as a general infrastructure.

  For this reason, for example, a hydrogen generator that uses raw materials supplied from existing fossil raw material infrastructure such as city gas and propane gas, and generates hydrogen-containing gas by reforming reaction of those raw materials and steam (water) is additionally provided. The

  Generally, a hydrogen generator includes a reforming unit that causes a reforming reaction between a raw material and water to generate a hydrogen-containing gas. Moreover, the structure which provides the carbon monoxide reduction part which reduces carbon monoxide in hydrogen-containing gas, the conversion part which carries out water-gas shift reaction of carbon monoxide and water vapor | steam, and the selective oxidation part which oxidizes carbon monoxide is taken. There are many cases.

  In these reaction parts, a catalyst suitable for each reaction, for example, a Ru catalyst or Ni catalyst is used in the reforming part, a Cu-Zn catalyst is used in the shift part, and a Ru catalyst is used in the selective oxidation part. Each reaction section has a suitable temperature. The reforming section is often used at about 650 ° C., the transformation section is used at about 200 ° C., and the selective oxidation section is used at about 150 ° C. in many cases.

  In addition, the sulfur compound added as an odorant or the sulfur compound originally contained in the raw material is mixed in the raw material supplied from the existing fossil raw material infrastructure such as city gas and propane gas. These sulfur compounds poison the catalyst used in the reformer and deprive its activity. Therefore, the sulfur compound in the raw material needs to be removed by a desulfurization apparatus before being supplied to the reformer.

  Currently, two types of desulfurization apparatuses are used: an adsorption desulfurization method and a hydrodesulfurization method. The adsorptive desulfurization method is a method of desulfurizing by passing the raw material through an adsorptive desulfurizer filled with an adsorbing desulfurizing agent that adsorbs sulfur compounds, and has the advantage that it is very easy to handle because it performs adsorptive desulfurization at room temperature. .

  On the other hand, in the hydrodesulfurization method, hydrogen sulfide is easily adsorbed by adding hydrogen to a raw material and passing it through a hydrodesulfurizer filled with a hydrodesulfurization catalyst heated to about 220 ° C. to 320 ° C. The hydrogen sulfide produced is adsorbed and removed with an adsorbing desulfurizing agent, and since the adsorption capacity is large, there is an advantage that it is not necessary to replace the adsorbing desulfurizing agent over a long period of time.

  Now, when the fuel cell power generation system is used for home use, it is possible to operate with high energy efficiency by performing the start / stop operation every day according to the power load at home. However, start / stop operation places a heavy burden on the fuel cell power generation system.

Particularly, since the hydrogen generator is repeatedly operated at a high temperature and cooled to room temperature, a large thermal strain is applied every day. As a result, the catalyst in the apparatus is pulverized to generate dust. In order to prevent the catalyst from flowing out from the reactor due to dusting and not contributing to the catalytic reaction, a configuration is proposed in which a filter is provided in the reforming tube to prevent the dust from flowing out (for example, Patent Document 1).

  In addition, in order to prevent a part of the catalyst in the reaction part from collapsing and the flow path of the reforming reaction gas (hydrogen-containing gas) to become obstructive, a partition member is provided in the reaction part to prevent the catalyst from collapsing. The structure which performs is proposed (for example, refer patent document 2).

  Furthermore, the reforming catalyst powder that dusts and accumulates is effectively trapped to prevent clogging of the flow path due to dust (see, for example, Patent Document 3), and a recess is provided for the shift catalyst that dusts and drops. A configuration that does not adversely affect the reaction (see, for example, Patent Document 4) has also been proposed.

Japanese Patent Application Laid-Open No. 5-76775 International Publication No. 2007/40146 JP 2011-6289 A JP 2012-201546 A

  In order to reduce the size and cost of a fuel cell power generation system, it is necessary to reduce the size of the hydrogen generator, and for that purpose, the amount of desulfurization agent and catalyst mounted on the hydrogen generator is set to the minimum required amount. It will be necessary.

  In order to reduce the amount of desulfurizing agent and catalyst to the required minimum amount, it is necessary to react the entire amount of desulfurizing agent or catalyst effectively, and against the upstream surface of the desulfurizing agent layer and catalyst layer installed in the hydrogen generator. It is necessary to apply the gas evenly.

  As a means for this, a configuration in which several gas flow holes are provided upstream of the desulfurization agent or catalyst and gas is ejected from the flow holes to the upstream surface of the desulfurization agent layer or catalyst layer is effective. In the configuration in which the gas passes from the bottom to the top in the direction of gravity of the desulfurizing agent layer or catalyst layer, a flow hole must be installed below the desulfurizing agent or catalyst layer. The catalyst may be pulverized and fall off to block the flow hole. When the flow hole is blocked, the pressure in the gas path increases and the operation cannot be continued.

  Then, this invention aims at providing the hydrogen generator which can prevent that the pressure | pressure of a gas path | route raises and it becomes impossible to continue an operation | movement by obstruct | occluding a through-hole by the desulfurization agent or the pulverized material from a catalyst. Yes.

  In order to solve the above-mentioned problems of the prior art, a hydrogen generator of the present invention comprises a reaction vessel provided in a gas flow path and containing a desulfurization agent or catalyst, and the desulfurization agent or catalyst disposed in the reaction vessel. A bottom lid that is supported from below and through which the gas passes, and at least one or more gas circulation holes and an inclined portion through which the gas flows are provided, and the interior of the reaction vessel is spaced from the bottom lid below the bottom lid. And a reservoir for storing the desulfurizing agent or catalyst powder on the lower side in the inclination direction of the inclined portion, the gas flow hole is provided in the inclined portion, and the gas flow hole The gas that has passed through is configured to flow toward the bottom lid.

As a result, in the configuration in which the gas is circulated from the bottom to the top in the direction of gravity of the desulfurizing agent or catalyst, even if the desulfurized agent or catalyst powder falls off to the lower part, the powdered material slides down the inclined portion.
It does not stay in the circulation hole, but accumulates in the reservoir.

  Further, the hydrogen generator according to the present invention is configured such that the reservoir is provided in proximity to a side wall opposite to a side wall that is heated from the outside among opposing side walls that constitute the reaction vessel. It has been done.

  As a result, even if the desulfurization agent or catalyst powder is accumulated in the accumulation portion, the amount of heating from the heating portion outside the reaction vessel to the reaction vessel is hardly affected.

  The hydrogen generator according to the present invention is operated even if a flow hole is installed below the desulfurizing agent or catalyst, and the pressure in the gas path increases due to the flow hole being blocked by the powder from the desulfurizing agent or catalyst. Can be prevented from continuing.

Schematic longitudinal cross-sectional view showing the configuration of the hydrogen generator in Embodiment 1 of the present invention Schematic longitudinal cross-sectional view which shows the structure of the hydrodesulfurizer in the hydrogen generator of Embodiment 2 of this invention Schematic longitudinal cross-sectional view which shows the structure of the hydrodesulfurizer in the hydrogen generator of Embodiment 3 of this invention Schematic longitudinal cross-sectional view which shows the structure of the hydrodesulfurizer in the hydrogen generator of Embodiment 4 of this invention Schematic longitudinal cross-sectional view which shows the structure of the hydrodesulfurizer in the hydrogen generator of Embodiment 5 of this invention Schematic longitudinal cross-sectional view which shows the structure of the hydrogen generator in Embodiment 6 of this invention

  A first invention is a reaction vessel provided in a gas flow path and containing a desulfurizing agent or a catalyst, a bottom lid disposed in the reaction vessel that supports the desulfurizing agent or the catalyst from below, and a gas passes therethrough. And at least one gas flow hole and an inclined portion provided in the reaction vessel at a distance from the bottom lid below the bottom lid, and a desulfurizing agent below the inclined direction in the inclined portion And a reservoir for storing the powdered catalyst, the gas flow hole is provided in the inclined portion, and the gas that has passed through the gas flow hole is configured to flow toward the bottom cover.

  As a result, even if the powdered material falls below the desulfurizing agent or the catalyst in the configuration in which the gas flows from the bottom to the top in the gravity direction of the desulfurizing agent or the catalyst, the powdered material slides down the inclined portion. Is not retained, but is accumulated in the reservoir, so that it is possible to prevent the flow hole from being blocked and the pressure in the gas path from rising to stop the operation.

In the second invention, in particular, in the hydrogen generator according to the first invention, the gas that has passed through the gas flow hole is introduced to approximately the center in the width direction of the desulfurizing agent or catalyst.

  As a result, the gas is uniformly applied to the upstream surface of the desulfurization agent layer and catalyst layer mounted on the hydrogen generator, and the performance of the desulfurization agent and the catalyst can be fully exhibited. Can be designed to the minimum required.

  In the third aspect of the invention, particularly in the hydrogen generator of the first or second aspect of the invention, the induction part is connected to the upper part of the partition member that divides the inside of the reaction vessel into a gas passage and a reservoir part. It is.

  Thereby, since the powdered material can be reliably collected in the accumulation part by gravity, the powdered material can be prevented from adversely affecting the performance of the device.

  According to a fourth aspect of the present invention, in the hydrogen generators of the first to third aspects of the invention, the reservoir is formed on the side wall opposite to the side wall heated from the outside among the opposing side walls constituting the reaction vessel. , Provided in close proximity.

  Thereby, even if pulverized material accumulates in the reservoir, the amount of heating from the outside of the reaction vessel to the reaction vessel is not reduced, and the performance of the hydrogen generator is not affected.

  In a fifth aspect of the invention, in particular, in the hydrogen generators of the first to fourth aspects of the invention, the reaction vessel is concentrically formed on a substantially cylindrical first wall whose central axis is in the vertical direction and on the outer peripheral side of the first wall. The second wall is disposed, and between the first wall and the second wall, a heating unit for heating the reaction vessel is provided on the inner peripheral side of the first wall.

  As a result, the gas is more easily distributed uniformly throughout the desulfurizing agent and the catalyst layer, and the guide portion and the reservoir portion including the flow holes are cylindrical, so that it is easily processed and molded.

  6th invention is a fuel cell system provided with the hydrogen generator of the 1st-4th invention, and the fuel cell which generates electric power using the hydrogen content gas supplied from this hydrogen generator.

  Hereinafter, embodiments of the hydrogen generator of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the present embodiment.

(Embodiment 1)
FIG. 1 is a schematic longitudinal sectional view showing a configuration of a hydrogen generator 1 according to Embodiment 1 of the present invention.

  In FIG. 1, the raw city gas supplied by adjusting the flow rate is supplied from a raw material supplier 2 to a hydrodesulfurizer 4 as a reaction vessel through a pipe 3. Here, the hydrodesulfurizer 4 is configured by being filled with a desulfurizing agent 5. The raw material from which sulfur has been removed by the hydrodesulfurizer 4 is mixed with the reforming water supplied from the water pipe 7 through the second pipe 6, and sent to the evaporator 9 through the mixing pipe 8.

  The mixed gas of the raw material and steam undergoes a steam reforming reaction by the reforming catalyst layer 11 heated to a high temperature in the reformer 10, and changes to a reformed gas containing hydrogen, carbon dioxide, and carbon monoxide. . The reformed gas passes through the reformed gas flow path 12 and enters the CO reduction catalyst layer 14 in the CO reducer 13, where the carbon monoxide concentration is reduced, and is taken out from the fuel pipe 17 as fuel gas. It is supplied to the fuel cell 18.

  A heat insulating material 30 is disposed outside the reformer 10 and the hydrodesulfurizer 4. The hydrogen that has not been consumed in the fuel cell 18 is supplied to the combustor 20 through the off-gas pipe 19 and used as a heat source for heating the hydrogen generator 1. The exhaust gas burned in the combustor 20 is exhausted through the exhaust gas pipe 21.

  Next, in the hydrogen generator 1 of the present embodiment, constituent parts until the city gas is supplied from the pipe 3 to the desulfurizing agent 5 will be described in more detail.

Below the desulfurization agent 5, a bottom lid 41 that supports the desulfurization agent 5 from below and through which city gas passes, at least one gas circulation hole 42 through which city gas flows, and an inclined portion 43 are installed. Is done. Further, below the bottom cover 41, a guide part 44 is provided at a distance from the bottom cover 41, and a reservoir part 45 for storing the powdered desulfurization agent 5 on the lower side in the inclined direction of the inclined part 43 is provided. ing.

  In FIG. 1, the gas circulation hole 42 is provided in the inclined portion 43 so that the city gas that has passed through the gas circulation hole 42 flows toward the bottom lid 41. Here, the city gas is configured such that the gas is once throttled through the gas circulation holes 42 and then dispersed in the desulfurizing agent 5.

  Since the city gas that has passed through the gas circulation holes 42 is introduced to the center of the desulfurizing agent 5 in the width direction, the entire amount of the desulfurizing agent 5 can react effectively. Designed. The guide portion 44 is connected to an upper portion of a partition member 46 that partitions the interior of the hydrodesulfurizer 4 into a city gas passage and a reservoir portion 45.

  The operation and action of the hydrogen generator 1 of the present embodiment configured as described above will be described below.

  Since the hydrogen generator 1, operation at high temperature, and cooling to room temperature are repeated, a large thermal strain is applied every day. As a result, the desulfurizing agent 5 may be pulverized and fall off to the lower part. In addition, the desulfurization agent 5 may be pulverized and fall off to the lower part when vertical, left and right vibrations are applied to the hydrogen generator 1 during transportation before equipment installation.

  When the desulfurizing agent 5 is pulverized and falls to the lower part, there is a concern that the gas flow hole 42 is blocked by the pulverized material, but the powdered material slides down the inclined portion 43, and thus the gas flow hole 42. It moves to the reservoir 45 instead of staying on. Therefore, it can be prevented that the gas flow hole 42 is blocked by the pulverized material from the desulfurizing agent 5 to increase the pressure of the gas path and the operation cannot be continued.

(Embodiment 2)
FIG. 2 is a schematic longitudinal sectional view showing the configuration of the hydrodesulfurizer 4 in the hydrogen generator 1 according to Embodiment 2 of the present invention. The difference from the hydrodesulfurizer 4 of the hydrogen generator 1 of Embodiment 1 of the present invention is that the angle of the inclined portion 43 is 90 degrees, and the gas flow holes 42 are horizontal, and other configurations are carried out. This is the same as the hydrogen generator 1 of the first embodiment.

  Since the hydrodesulfurizer 4 in the hydrogen generator 1 of Embodiment 2 has the gas flow hole 42 in a horizontal position, the gas flow hole 42 is blocked by the pulverized material from the desulfurizing agent 5, thereby causing a pressure in the gas path. It is possible to prevent the situation where the vehicle rises and the driving cannot be continued.

(Embodiment 3)
FIG. 3 is a schematic longitudinal sectional view showing the configuration of the hydrodesulfurizer 4 in the hydrogen generator 1 according to Embodiment 3 of the present invention. The difference from the hydrodesulfurizer 4 of the hydrogen generator 1 of Embodiment 1 of the present invention is that the angle of the inclined portion 43 is an angle exceeding 90 degrees, and the gas flow hole 42 is inclined downward, Other configurations are the same as those of the hydrogen generator 1 of the first embodiment.

  Since the hydrodesulfurizer 4 in the hydrogen generator 1 of Embodiment 3 has the gas flow holes 42 obliquely downward, the gas flow holes 42 are blocked by the pulverized material from the desulfurizing agent 5, thereby causing a gas path. It is possible to prevent a situation in which the operation of the vehicle cannot be continued due to an increase in pressure.

(Embodiment 4)
FIG. 4 is a schematic longitudinal sectional view showing the configuration of the hydrodesulfurizer 4 in the hydrogen generator 1 according to Embodiment 4 of the present invention. The difference from the hydrodesulfurizer 4 of the hydrogen generator 1 according to Embodiment 1 of the present invention is that the angle of the inclined portion 43 is 180 degrees and the gas flow hole 42 faces downward, and other configurations are carried out. This is the same as the hydrogen generator 1 of the first embodiment.

  Since the hydrodesulfurizer 4 in the hydrogen generator 1 of Embodiment 4 has the gas flow hole 42 facing downward, the gas flow hole 42 is blocked by the pulverized material from the desulfurizing agent 5, thereby causing the gas flow hole 42 to close. It is possible to prevent a situation in which the pressure increases and the operation cannot be continued.

(Embodiment 5)
FIG. 5 is a schematic longitudinal sectional view showing the configuration of the hydrodesulfurizer 4 in the hydrogen generator 1 according to Embodiment 5 of the present invention.

  The difference from the hydrodesulfurizer 4 of the hydrogen generator 1 of Embodiment 1 of the present invention is that the angle of the inclined portion 43 is 90 degrees, and the partition member 46 is divided into a partition member 46A which is a cylindrical two-part and a partition member 46A. And the reservoir 45 is installed in the space formed between the partition member 46A and the partition member 46B, and the other configuration is the same as that of the hydrogen generator 1 of the first embodiment. It is the same.

  Since the hydrodesulfurizer 4 in the hydrogen generator 1 of Embodiment 5 has the gas flow hole 42 in a horizontal position, the gas flow hole 42 is blocked by the pulverized material from the desulfurizing agent 5, thereby causing a pressure in the gas path. It is possible to prevent the situation where the vehicle rises and the driving cannot be continued.

(Embodiment 6)
FIG. 6 is a schematic longitudinal sectional view showing the configuration of the hydrogen generator 1 according to Embodiment 6 of the present invention.

  In FIG. 6, the raw city gas supplied by adjusting the flow rate is supplied from the raw material supplier 2 to the hydrogen generator 1 through the pipe 3, mixed with the reforming water supplied from the water pipe 7, and mixed with the mixing pipe 8. To the evaporator 9. The mixed gas of the raw material and steam undergoes a steam reforming reaction by the reforming catalyst layer 11 heated to a high temperature in the reformer 10, and changes to a reformed gas containing hydrogen, carbon dioxide, and carbon monoxide. .

  The reformed gas passes through the reformed gas flow path 12 and enters the CO reduction catalyst layer 14 in the CO reducer 13, where the carbon monoxide concentration is reduced, and is taken out from the fuel pipe 17 as fuel gas. It is supplied to the fuel cell 18.

  A heat insulating material 30 is disposed outside the reformer 10. The hydrogen that has not been consumed in the fuel cell 18 is supplied to the combustor 20 through the off-gas pipe 19 and used as a heat source for heating the hydrogen generator 1. The exhaust gas burned in the combustor 20 is exhausted through the exhaust gas pipe 21.

  Next, in the hydrogen generator 1 of the present embodiment, the constituent parts until the reformed gas enters the CO reduction catalyst layer 14 from the reformed gas channel 12 will be described in more detail.

  Below the CO reduction catalyst layer 14, a bottom lid 41 that supports the CO reduction catalyst layer 14 from below and through which the reformed gas passes, at least one gas flow hole 42 through which the reformed gas flows, and an inclined portion 43 are installed respectively. Further, below the bottom lid 41, there are provided a guide portion 44 spaced apart from the bottom lid 41, and a reservoir portion 45 for storing the pulverized product of the CO reducing catalyst on the lower side in the inclined direction of the inclined portion 43. ing.

In FIG. 6, the gas flow hole 42 is provided in the inclined portion 43 so that the reformed gas that has passed through the gas flow hole 42 flows toward the bottom lid 41. Here, the reformed gas is once squeezed through the gas flow holes 42, and then the gas is dispersed in the CO reduction catalyst layer 14. The reformed gas that has passed through the gas circulation holes 42 is configured to be led to substantially the center in the width direction of the CO reducing catalyst layer 14.

  With this configuration, even if the CO reduction catalyst of the CO reduction catalyst layer 14 is pulverized and falls to the lower part, the pulverized material slides down the inclined portion 43, so that it does not stay in the gas flow hole 42 but moves to the reservoir 45. . Therefore, it can be prevented that the gas flow hole 42 is blocked by the pulverized material from the CO reducing catalyst in the CO reducing catalyst layer 14 and the pressure in the gas path rises so that the operation cannot be continued.

  In addition, it cannot be overemphasized that the fuel cell system can be comprised with the hydrogen generator 1 in any one of Embodiment 1-6 and the fuel cell 18 which generate | occur | produces electricity using the hydrogen containing gas supplied from this hydrogen generator 1. .

  As described above, the hydrogen generator according to the present invention has a structure in which a gas ejection hole is provided below the desulfurization agent or the catalyst layer, and even if the desulfurization agent or the catalyst is pulverized and dropped, the gas ejection port is blocked. Therefore, the operation can be continued without increasing the pressure of the gas path, so that it can be applied not only to a hydrogen generator having a hydrodesulfurizer but generally to a device having a desulfurizing agent or a catalyst.

DESCRIPTION OF SYMBOLS 1 Hydrogen generator 2 Raw material supply device 3 Piping 4 Hydrodesulfurizer 5 Desulfurization agent 6 2nd piping 7 Water piping 8 Mixing piping 9 Evaporator 10 Reformer 11 Reforming catalyst layer 12 Reformed gas flow path 13 CO reducer 14 CO Reduction Catalyst Layer 17 Fuel Pipe 18 Fuel Cell 19 Off Gas Pipe 20 Combustor 21 Exhaust Gas Pipe 30 Heat Insulation Material 41 Bottom Cover 42 Gas Flow Hole 43 Inclined Part 44 Guide Part 45 Reservoir Part 46 Partition Member 46A Partition Member 46B Partition Member

Claims (6)

A reaction vessel provided in a gas flow path and containing a desulfurizing agent or a catalyst;
A bottom lid disposed in the reaction vessel for supporting the desulfurizing agent or catalyst from below and through which the gas passes;
At least one gas flow hole through which the gas flows and an inclined part, and a guide part disposed in the reaction vessel at a distance from the bottom cover below the bottom cover;
A reservoir for storing the desulfurizing agent or catalyst powder on the lower side of the inclined portion in the inclined direction;
With
The gas flow hole is provided in the inclined portion, and the gas that has passed through the gas flow hole is configured to flow toward the bottom cover.
Hydrogen generator. The hydrogen generation apparatus according to claim 1, wherein the gas that has passed through the gas flow hole is led to substantially the center in the width direction of the desulfurization agent or catalyst. The guide portion is connected to an upper portion of a partition member that partitions the inside of the reaction vessel into the gas passage and the pool portion,
The hydrogen generator according to claim 1 or 2. The reservoir is provided close to a side wall opposite to the side wall heated from the outside among the opposing side walls constituting the reaction vessel,
The hydrogen generator according to any one of claims 1 to 3. The reaction vessel includes a substantially cylindrical first wall whose central axis is vertical, and a second wall disposed concentrically on the outer peripheral side of the first wall, the first wall and the second wall A heating part for heating the reaction vessel on the inner peripheral side of the first wall,
The hydrogen generator according to any one of claims 1 to 4.   A fuel cell system comprising: the hydrogen generator according to any one of claims 1 to 5; and a fuel cell that generates electric power using a hydrogen-containing gas supplied from the hydrogen generator.

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