JP2016130191A - Hydrogen generator and fuel cell system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove a stable sulfur compound in a hydrogen generator equipped with an ejector for sucking a hydrogen-containing gas from a recycled gas path in a passage for supplying a raw material gas to a hydrogenation desulfurizer.SOLUTION: There is provided a hydrogen generator which comprises: a reformer 4 for reforming a raw material gas passed through a hydrogenation desulfurizer 1 to generate a fuel gas containing hydrogen; a fuel gas path 5 for discharging the fuel gas from the reformer 4; a recycled gas path 6 which branches from the fuel gas path 5 and converges to a raw material supply path 2 at the downstream side of the flow of the raw material gas from a raw material supplier 3 and mixes a part of the fuel gas discharged from the reformer 4 with the raw material gas; an ejector 7 disposed at a first converging portion where the raw material supply path 2 and the recycled gas path 6 are converged; and a raw material circulation path 8 which branches from between the ejector 7 and the hydrogenation desulfurizer 1 and is connected to the upstream side of the flow of the raw material gas from the raw material supplier 3 and is configured so that a part of the raw material gas is supplied to the raw material supplier 3.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a hydrogen generator equipped with a hydrodesulfurizer and a fuel cell system.

  Conventionally, in a fuel cell system, since a hydrogen-containing gas used as a fuel for power generation has not been developed as a general raw material infrastructure, a hydrogen-containing gas is usually generated from natural gas or LPG which is a general raw material infrastructure. A hydrogen generator having a reformer is provided.

  In the reformer, a steam reforming reaction is generally used. In this steam reforming reaction, for example, a raw city gas and steam are reacted at a high temperature of about 600 ° C. to 700 ° C. using a Ru-based noble metal-based reforming catalyst or a Ni-based reforming catalyst. Thus, a hydrogen-containing gas mainly containing hydrogen is generated.

  By the way, sulfur gas is contained in source gas, such as city gas, and since this sulfur compound is especially a poisoning substance of a reforming catalyst or a fuel cell stack catalyst, it must be removed by some method.

  As a hydrogen generator for removing a sulfur compound, there is a hydrogen generator for mixing a hydrogen-containing gas and a raw material gas and removing them by hydrodesulfurization using a hydrodesulfurization catalyst. As a method of supplying the hydrogen-containing gas, a method of returning the hydrogen-containing gas generated by the reforming catalyst to the raw material gas supply path (hereinafter referred to as recycling) is generally used.

  Here, as a method of recycling the hydrogen-containing gas into the raw material gas, an ejector is provided in the path for supplying the raw material gas to the hydrodesulfurization catalyst, the hydrogen-containing gas is sucked by the venturi effect by the ejector, and the raw material gas and the hydrogen-containing gas are A hydrogen generator to be mixed has been proposed (see, for example, Patent Document 1).

  FIG. 10 shows a schematic configuration of the hydrogen generator described in Patent Document 1. As shown in FIG. 10, the hydrogen generator 100 includes a hydrodesulfurizer 1, a raw material supply path 2, a raw material supplier 3, a reformer 4, a fuel gas path 5, a recycle gas path 6, It consists of an ejector 7.

  By this hydrogen generator 100, a part of the fuel gas containing hydrogen generated by the reformer 4 is supplied to the ejector 7 through the recycle gas path 6. The raw material gas and the fuel gas are mixed in the ejector 7, and the sulfur compound and hydrogen in the raw material gas react in the hydrodesulfurizer 1 to remove the sulfur compound.

JP 2013-222573 A

However, in the conventional configuration described above, in order to suck the fuel gas, which is a hydrogen-containing gas, from the recycle gas path 6 by the ejector 7, it is necessary to supply the raw material gas to the ejector 7 at a flow rate higher than a predetermined flow rate. When the raw material gas flowing to the ejector 7 falls below a predetermined flow rate, the gas suction capability due to the venturi effect is reduced in the ejector 7, and the necessary fuel gas cannot be sucked from the recycle gas path 6, and sulfur compounds are removed by hydrodesulfurization. Had the problem of not being able to do.

  The present invention solves the above-mentioned conventional problems, and in a hydrogen generator for sucking a hydrogen-containing gas from a recycle gas path by an ejector provided in a path for supplying a source gas to a hydrodesulfurizer, the source gas An object of the present invention is to enable a hydrogen-containing gas to be sucked by an ejector by a venturi effect even when the flow rate is reduced below a predetermined flow rate, and to remove sulfur compounds by stable hydrodesulfurization.

  In order to solve the above-described conventional problems, the hydrogen generator of the present invention includes a hydrodesulfurizer that removes a sulfur compound in a raw material gas by reacting with hydrogen, and a raw material that supplies the raw gas to the hydrodesulfurizer A supply path, a raw material supply apparatus that is disposed in the raw material supply path and supplies the raw material gas to the hydrodesulfurizer, and reforms the raw material gas that has passed through the hydrodesulfurizer to generate a fuel gas containing hydrogen A reformer, a fuel gas path for discharging the fuel gas from the reformer, and a branch from the fuel gas path, and joins the raw material supply path downstream of the raw material gas flow from the raw material supplier. A recycle gas path for mixing a part of the fuel gas discharged from the reformer with a raw material gas; an ejector disposed at a first merge portion where the raw material supply path and the recycle gas path merge; Ejector and hydrodesulfurization And a raw material circulation path connected to the upstream side of the flow of the raw material gas from the raw material supplier and configured to supply a part of the raw material gas to the raw material supplier. is there.

  As a result, in addition to the raw material gas supplied from the outside to the hydrogen generator, a mixed gas of the raw material gas and the recycle gas that is circulated through the raw material circulation path can be circulated to the ejector. The flow rate can be increased.

  As a result, even when the flow rate of the raw material gas supplied from the outside to the hydrogen generator is small and the venturi effect is difficult to exert in the ejector, the flow rate of gas flowing to the ejector can be increased, and the venturi effect in the ejector is sufficient. The recycle gas can be sucked by the ejector, and stable desulfurization performance by hydrodesulfurization can be exhibited.

  The fuel cell system of the present invention includes the above-described hydrogen generator of the present invention and a fuel cell that generates power using fuel gas supplied from the hydrogen generator.

  This makes it possible to generate power in the fuel cell using the fuel gas from which sulfur compounds in the raw material gas have been stably removed by hydrodesulfurization.

  A hydrogen generation apparatus and a fuel cell system according to the present invention include a hydrogen generation apparatus that sucks a hydrogen-containing gas from a recycle gas path by an ejector provided in a path for supplying a raw material gas to a hydrodesulfurizer. It is possible to remove the sulfur compound stably without running out of the flow rate of the recycle gas to circulate, and it is possible to realize the operation with improved reliability.

The block diagram which shows an example of schematic structure of the hydrogen generator in Embodiment 1 of this invention The block diagram which shows an example of schematic structure of the hydrogen generator in the 1st modification of Embodiment 1 of this invention. The block diagram which shows an example of schematic structure of the hydrogen generator in Embodiment 2 of this invention The block diagram which shows an example of schematic structure of the hydrogen generator in the 1st modification of Embodiment 2 of this invention. The flowchart which shows an example of the operating method of the hydrogen generator in the 1st modification of Embodiment 2 of this invention. The block diagram which shows an example of schematic structure of the hydrogen generator in the 1st modification of Embodiment 3 of this invention. The block diagram which shows an example of schematic structure of the hydrogen generator in the 2nd modification of Embodiment 3 of this invention. The block diagram which shows an example of schematic structure of the hydrogen generator in Embodiment 4 of this invention FIG. 9 is a block diagram showing an example of a schematic configuration of a fuel cell system according to Embodiment 5 of the present invention. A block diagram showing an example of a schematic configuration of a conventional hydrogen generator

  A first invention is a hydrodesulfurizer that removes sulfur compounds in a raw material gas by reacting with hydrogen, a raw material supply path that supplies the raw material gas to the hydrodesulfurizer, a raw material supply path, and a raw material gas A raw material supplier for supplying hydrogen to the hydrodesulfurizer, a reformer for reforming the raw material gas that has passed through the hydrodesulfurizer to produce a fuel gas containing hydrogen, and a fuel for discharging the fuel gas from the reformer Recycle that branches from the gas path and the fuel gas path, joins the raw material supply path downstream of the raw material gas flow from the raw material supplier, and mixes part of the fuel gas discharged from the reformer with the raw material gas The gas path, the ejector disposed at the first junction where the raw material supply path and the recycle gas path merge, and the ejector and the hydrodesulfurizer branch from the upstream of the raw material gas flow from the raw material supplier. A part of the raw material gas is supplied to the raw material. Is a hydrogen generating apparatus and a material circulation path configured to supply the.

  With the above configuration, in addition to the raw material gas supplied to the hydrogen generator from the outside, the mixed gas of the raw material gas and the recycle gas that is circulated through the raw material circulation path can be circulated to the ejector, and is distributed to the ejector. The gas flow rate can be increased.

  As a result, even when the raw material gas flow rate supplied to the hydrogen generator from the outside is small and it is difficult to exert the gas suction capability due to the venturi effect in the ejector, the flow rate of gas flowing to the ejector can be increased. The venturi effect can be sufficiently exerted, and even when the flow rate of the raw material gas supplied without going through the raw material circulation path falls below a predetermined flow rate, the recycle gas can be sucked by the ejector. This makes it possible to remove a stable sulfur compound by hydrodesulfurization.

  In particular, the second invention is provided with an on-off valve in the raw material circulation path of the hydrogen generator of the first invention.

  With the above configuration, the flow rate of the fuel gas supplied from the recycle gas path and mixed with the raw material gas in the ejector is not short of the flow rate of the fuel gas required for the hydrogenation reaction in the hydrodesulfurizer. It is possible to control the fuel gas suction capability of the ejector by opening and closing the on-off valve of the raw material circulation path to increase or decrease the gas flow rate flowing to the ejector, and to supply fuel gas stably to the hydrodesulfurizer Become.

In particular, in addition to the configuration of the hydrogen generator of the first invention, the third invention is supplied to the on-off valve arranged in the raw material circulation path and the second junction where the raw material circulation path joins the raw material supply path. And a controller for controlling the on-off valve based on the flow rate of the raw material gas in the raw material supply path.

  With the above configuration, it is possible to open and close the on-off valve of the raw material circulation path according to the flow rate of the raw material gas supplied to the hydrogen generator, and open the open / close valve when the flow rate of the raw material gas supplied to the hydrogen generator is small This increases the flow rate of the gas flowing to the ejector, and when the flow rate of the raw material gas supplied to the hydrogen generator is large, the recycle flows through the recycle gas path by closing the on-off valve and not increasing the flow rate of the gas flowing to the ejector. It is possible to prevent the gas flow rate from being insufficient, and to stably perform hydrodesulfurization in the hydrodesulfurizer.

  In particular, the fourth aspect of the invention detects the flow rate of the raw material gas in the raw material supply path supplied to the second junction where the raw material circulation path joins the raw material supply path in addition to the configuration of the hydrogen generator of the third aspect of the invention. If the flow rate of the raw material gas detected by the raw material supply amount detection means is not more than the first predetermined value, the controller controls to open the on-off valve.

  With the above configuration, the flow rate of the raw material gas supplied to the hydrogen generator is detected, and when the raw material gas flow rate is equal to or lower than the first predetermined value, the on-off valve can be opened, and the flow rate of the gas supplied to the ejector is reduced. The fuel gas suction flow rate from the recycle gas path by the ejector can be increased.

  In the fifth aspect of the invention, in particular, the raw material supply amount detection means in the hydrogen generator of the fourth aspect of the present invention is a raw material supply path upstream of the flow of the raw material gas from the second joining portion where the raw material circulation path joins the raw material supply path. Or, a raw material supply path downstream of the flow of the raw material gas from the branch portion where the raw material circulation path branches from the raw material supply path, or a raw material gas path from the hydrodesulfurizer to the reformer, or a reformer To the recycle gas path, or the first flow meter arranged in the fuel gas path after branching the recycle gas path.

  With the above configuration, the raw material gas flow from the raw material supply path upstream of the flow of the raw material gas from the second merging portion where the raw material circulation path merges with the raw material supply route, or the branch portion where the raw material circulation path branches from the raw material supply route The feed gas supply path on the downstream side, the feed gas path from the hydrodesulfurizer to the reformer, the fuel gas path from the reformer to the recycle gas path, or the recycle gas path The on-off valve can be controlled based on the gas flow rate detected by the first flow meter disposed in the fuel gas path after the fuel gas flow is prevented, and the fuel gas flow rate through the recycle gas path is prevented from being insufficient. Sulfur compounds can be stably removed with a desulfurizer.

  In the sixth aspect of the invention, in particular, in addition to the configuration of the hydrogen generator of the first aspect of the invention, the on-off valve is controlled based on the on-off valve disposed in the raw material circulation path and the flow rate of the raw material gas flowing through the ejector. It is equipped with a controller.

  With the above configuration, the fuel gas suction capacity from the recycle gas path in the ejector can be understood from the flow rate of the raw material gas flowing through the ejector, so that it is possible to supply fuel gas that is sufficient hydrogen-containing gas to the hydrodesulfurizer. If fuel gas is insufficient, open the on-off valve to increase the flow rate of gas flowing to the ejector, increase the flow rate of fuel gas supplied to the hydrodesulfurizer, and feed the flow through the ejector When the gas flow rate is high, the on-off valve is closed so that the flow rate of the fuel gas supplied from the recycle gas path is not increased, so that the suction of the fuel gas through the recycle gas path is stabilized by the ejector, and hydrodesulfurization The sulfur compound can be stably removed by hydrodesulfurization in a vessel.

In particular, the seventh invention includes an ejector flow rate detecting means for detecting the flow rate of the raw material gas flowing through the ejector in addition to the configuration of the hydrogen generator of the sixth invention, and is detected by the ejector flow rate detecting means. If the flow rate of the raw material gas is equal to or less than the second predetermined value, the controller controls to open the on-off valve.

  With the above configuration, the flow rate of the raw material gas flowing through the ejector is detected, and if the flow rate is less than or equal to the second predetermined value, the on-off valve is opened to increase the flow rate of the gas flowing through the ejector and sucked from the recycle gas path. Therefore, it is possible to stably remove the sulfur compound by hydrodesulfurization in the hydrodesulfurizer by increasing the fuel gas flow rate.

  In the eighth aspect of the invention, in particular, the output of the raw material supplier is used as the ejector flow rate detection means in the hydrogen generator of the seventh aspect of the invention.

  With the above configuration, it is not necessary to separately provide an ejector flow rate detecting means, and the flow rate of the raw material gas supplied to the hydrodesulfurizer can be detected by the output of the raw material supplier.

  In the ninth aspect of the invention, in particular, as the ejector flow rate detection means in the hydrogen generator of the seventh aspect of the invention, the second merging portion where the raw material circulation path merges with the raw material supply path, and the raw material circulation path branches from the raw material supply path A second flow meter disposed in the raw material supply path between the branch portion and the branch portion is used.

  With the above configuration, the flow rate of the gas flowing through the ejector can be detected by the second flow meter, and the controller controls the on-off valve based on the gas flow rate flowing through the ejector. It is possible to stably remove the sulfur compound by hydrodesulfurization of the catalyst.

  The tenth aspect of the invention includes, in particular, a pressure gauge for detecting the differential pressure on the inlet side and the outlet side of the ejector as the ejector flow rate detecting means in the hydrogen generator of the seventh aspect of the invention, and the differential pressure detected by the pressure gauge is If it is below the third predetermined value set in advance, the controller controls to open the on-off valve.

  With the above configuration, it becomes possible to detect the gas flow rate flowing through the ejector with the pressure gauge, and if the detected pressure is equal to or lower than the third predetermined value, the on-off valve is opened to flow through the recycle gas path. It is possible to prevent the flow rate of the fuel gas from decreasing and to stably remove the sulfur compound by hydrodesulfurization in the hydrodesulfurizer.

  In an eleventh aspect of the invention, in particular, in addition to the configuration of the hydrogen generator of the first aspect, an on-off valve is provided on the basis of an on-off valve disposed in the raw material circulation path and a flow rate of fuel gas flowing through the recycle gas path. It has a controller to control.

  With the above configuration, it is possible to prevent the fuel gas flowing through the recycle gas path from being insufficient, and it is possible to stably flow the fuel gas through the recycle gas path, and sulfur due to hydrodesulfurization in the hydrodesulfurizer. It is possible to stably remove the compound.

  In particular, the twelfth invention includes, in addition to the configuration of the hydrogen generator of the eleventh invention, a recycle gas path flow rate detecting means for detecting the flow rate of the fuel gas flowing through the recycle gas path. If the flow rate of the fuel gas detected by the flow rate detection means is equal to or lower than the fourth predetermined value, the controller controls to open the on-off valve.

  With the above configuration, it is possible to increase the suction ability of the fuel gas by the ejector, increase the flow rate of the fuel gas flowing through the recycle gas path, and stably remove sulfur compounds by hydrodesulfurization in the hydrodesulfurizer. It becomes possible.

  In the thirteenth aspect of the invention, in particular, the recycle gas path flow rate detecting means in the hydrogen generator of the twelfth aspect of the invention is a third flow meter arranged in the recycle gas path.

  With the above configuration, the flow rate of the fuel gas flowing through the recycle gas path can be detected with the third flow meter arranged in the recycle gas path.

  In the fourteenth aspect of the invention, in particular, the controller in the hydrogen generator of the fifth aspect of the invention controls the raw material gas supplier based on the flow rate detected by the first flow meter.

  With the above configuration, it is possible to supply the raw material gas at a necessary flow rate to the hydrogen generator, and it is possible to stably generate the fuel gas that is a hydrogen-containing gas.

  In particular, the fifteenth aspect of the invention includes, in addition to the configuration of the hydrogen generator according to any one of the first to fourth and sixth to thirteenth aspects, a second merging portion where the raw material circulation path merges with the raw material supply path. A fourth flow meter arranged in the raw material supply path upstream of the raw material gas flow is provided, and the controller controls the raw material gas supply device based on the flow rate detected by the fourth flow meter.

  With the above configuration, it is possible to supply the raw material gas at a necessary flow rate to the hydrogen generator, and it is possible to stably generate the fuel gas that is a hydrogen-containing gas.

  A sixteenth aspect of the invention is a fuel cell system comprising, in particular, the hydrogen generator of any one of the first to fifteenth aspects of the invention and a fuel cell that generates power using fuel gas supplied from the hydrogen generator. is there.

  With the above configuration, it becomes possible to generate power from the fuel gas from which sulfur compounds have been removed, prevent deterioration due to sulfur poisoning of the fuel cell system equipped with a hydrodesulfurizer, and realize stable power generation. Reliability can be improved.

  Hereinafter, embodiments 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 block diagram showing an example of a schematic configuration of a hydrogen generator according to Embodiment 1 of the present invention.

  In FIG. 1, the hydrogen generator 100 of the present embodiment includes a hydrodesulfurizer 1, a raw material supply path 2, a raw material supply apparatus 3, a reformer 4, a fuel gas path 5, and a recycle gas path 6. And a first junction, an ejector 7 and a raw material circulation path 8.

  The hydrodesulfurizer 1 that removes sulfur compounds in the raw material gas supplied to the reformer 4 has a configuration in which a desulfurization agent for hydrodesulfurization is filled in a container. Examples of the desulfurization agent for hydrodesulfurization include, for example, a CoMo-based catalyst that converts a sulfur compound in a raw material into hydrogen sulfide, and a ZnO-based catalyst that is a sulfur adsorbent that is provided downstream thereof to adsorb and remove hydrogen sulfide, or It is comprised with a CuZn-type catalyst.

  The desulfurization agent for hydrodesulfurization is not limited to this example, and may be composed of only a CuZn-based catalyst having both a function of converting a sulfur compound into hydrogen sulfide and a function of adsorbing hydrogen sulfide. Further, the hydrodesulfurizer 1 reacts the sulfur compound in the raw material gas with hydrogen-containing gas to convert it into hydrogen sulfide, and then not only adsorbs and removes the hydrogen sulfide, but also in the raw material gas without the hydrogen-containing gas. It is also possible to physically adsorb the sulfur compounds directly.

  However, since physical adsorption requires a larger amount of desulfurization agent for hydrodesulfurization than adsorption removal with hydrogen sulfide, adsorption removal with hydrogen sulfide is common in normal use. However, physical adsorption is used in the present embodiment only when the hydrogen generator is started or stopped, which is the timing when the hydrogen-containing gas is not generated.

  The raw material supply path 2 is a path for supplying a raw material gas to the hydrodesulfurizer 1 and is a pipe or the like that guides the raw material gas supplied to the hydrogen generator 100 to the hydrodesulfurizer 1. The raw material supply path 2 may have any configuration as long as the raw material gas can flow.

  The raw material supplier 3 is a device that is disposed in the raw material supply path 2 and supplies the raw material gas to the hydrodesulfurizer 1, and adjusts the flow rate of the raw material gas supplied to the hydrodesulfurizer 1. For example, although it is configured by a booster and a flow rate adjustment valve, it may be configured by any one of these.

  As the booster, for example, a constant displacement pump is used, but is not limited thereto. The source gas is supplied from the source supply source through the source supply path 2. The raw material supply source has a predetermined supply pressure, and examples thereof include a raw material gas cylinder and a raw material gas infrastructure.

  The reformer 4 reforms the raw material gas from which the sulfur compound is removed by the hydrodesulfurizer 1 to generate a fuel gas containing hydrogen. Specifically, in the reforming catalyst section (not shown) in the reformer 4, the raw material gas undergoes a reforming reaction to generate a hydrogen-containing gas. The reforming reaction may take any form, and examples thereof include a steam reforming reaction, an autothermal reaction, and a partial oxidation reaction.

  Although not shown in FIG. 1, equipment required for each reforming reaction is provided as appropriate. For example, if the reforming reaction is a steam reforming reaction, a combustor that heats the reforming catalyst unit, an evaporator that generates steam, and a water supplier that supplies water to the evaporator are provided. If the reforming reaction is an autothermal reaction, the hydrogen generator 100 is further provided with an air supply device (not shown) for supplying air to the reformer.

  The source gas contains an organic compound composed of at least carbon and hydrogen, such as city gas mainly composed of methane, natural gas, and LPG.

  The fuel gas path 5 is a path for discharging the fuel gas, which is a hydrogen-containing gas generated in the reformer 4, from the reformer 4. The fuel gas is supplied through a fuel gas path 5 to a device that uses the fuel gas. Examples of equipment that uses a hydrogen-containing gas include a fuel cell.

  The recycle gas path 6 branches a part of the fuel gas sent from the reformer 4 through the fuel gas path 5 from the fuel gas path 5, and the raw material supply path downstream of the raw material gas flow from the raw material supplier 3. 2, and a part of the fuel gas discharged from the reformer 4 is mixed with the raw material gas. By branching the fuel gas path 5, a part of the fuel gas is sent to the raw material supply path 2, where the raw material gas and the fuel gas that is a hydrogen-containing gas are mixed.

  The upstream end of the recycle gas path 6 may be connected to any location as long as the fuel gas sent from the reformer 4 flows. For example, when a CO reducer that reduces carbon monoxide in the fuel gas is provided downstream of the reformer 4, the upstream end of the recycle gas path 6 is a flow path between the reformer 4 and the CO reducer. May be connected to the CO reducer, or may be connected to the CO reducer, or may be connected downstream of the CO reducer.

When the CO reducer includes a shifter that reduces carbon monoxide by a shift reaction and a CO remover that reduces carbon monoxide by at least one of an oxidation reaction and a methanation reaction, the recycle gas path 6 You may comprise so that the upstream end of may be connected to the flow path between a transformer and a CO remover. Moreover, you may connect the upstream end of the recycle gas path | route 6 to the downstream flow path of the hydrogen utilization apparatus using hydrogen containing gas.

  Note that the hydrogen generator 100 does not necessarily have a CO reducer or a CO remover. If the hydrogen generator 100 can provide the necessary performance for an apparatus that uses the fuel gas generated by the hydrogen generator 100, It does n’t matter.

  The first junction (not shown) is a portion where the raw material supply path 2 and the recycle gas path 6 merge. The raw material gas that circulates through the raw material supply path 2 and the fuel gas that circulates through the recycle gas path 6 merge and mix at the first merging portion.

  The ejector 7 is disposed in a first junction where the raw material supply path 2 and the recycle gas path 6 merge. The ejector 7 increases the flow rate of the gas by narrowing the cross-sectional area of the flow path through which the raw material gas pumped by the raw material supplier 3 such as a booster, and at the position where the flow velocity of the raw material gas becomes maximum, the recycle gas path 6 is an apparatus configured to join the raw material supply path 2.

  By increasing the flow velocity, the pressure of the raw material gas at that portion can be reduced by the venturi effect. At the position where the flow rate of the raw material gas is maximum, the pressure of the raw material gas is the lowest. By designing this pressure to be lower than the pressure upstream of the recycle gas path 6, the hydrogen-containing gas can flow into the raw material supply path 2 through the recycle gas path 6.

  If the hydrogen-containing gas can flow into the raw material supply path 2 by the Venturi effect, the hydrogen-containing gas does not necessarily have to flow in at a position where the flow rate of the raw material gas becomes maximum.

  The raw material circulation path 8 branches from between the ejector 7 and the hydrodesulfurizer 1, is connected to the upstream side of the flow of the raw material gas from the raw material supplier 3, and is supplied from the ejector 7 to the hydrodesulfurizer 1. It is a path | route comprised so that a part of may be supplied to the raw material supply device 3. The raw material circulation path 8 may have any configuration as long as gas can flow.

  The operation and action of the hydrogen generator 100 configured as described above will be described below with reference to FIG.

  First, when the hydrogen generator 100 generates fuel gas containing hydrogen, the following operation is performed.

  The raw material gas is supplied to the hydrodesulfurizer 1 through the raw material supply path 2 by the raw material supplier 3, and the sulfur compound in the raw material gas is removed by the hydrodesulfurizer 1. The raw material gas from which the sulfur compound is removed is supplied to the reformer 4 to generate a fuel gas containing hydrogen.

  A part of the fuel gas generated by the reformer 4 is sucked by the venturi effect by the ejector 7 through the recycle gas path 6. The sucked fuel gas and the raw material gas are mixed and then supplied to the hydrodesulfurizer 1.

  In the ejector 7, the flow path cross-sectional area of the raw material gas distribution path gradually narrows, and then merges with the recycle gas path 6 and then the flow path cross-sectional area of the flow path through which the mixed gas of the raw material gas and the recycle gas flows. Is configured to gradually increase. As a result, the flow rate of the raw material becomes the fastest and the pressure of the raw material becomes the lowest at the junction of the raw material gas and the recycle gas.

  By designing the cross-sectional area of the flow path so that the pressure of the source gas at this time is lower than the pressure on the upstream side of the recycle gas path 6, the recycle gas can be drawn into the source supply path 2.

  When the fuel gas is supplied to the hydrodesulfurizer 1, the sulfur compound and hydrogen react with each other in the hydrodesulfurizer 1 to form hydrogen sulfide, which is adsorbed and removed by the hydrodesulfurization catalyst.

  Until the fuel gas is supplied to the hydrodesulfurizer 1, it is possible to physically adsorb and remove sulfur compounds in the hydrodesulfurizer 1. Since the desulfurization catalyst physically removes the sulfur compound by adsorption and removes the sulfur compound by using hydrogen-containing fuel gas, the load is large and the catalyst life is shortened. Until the gas is supplied, the sulfur compound in the raw material gas may be removed by a separate adsorption desulfurizer (not shown).

  While the fuel gas is being generated in the hydrogen generator 100, the fuel that is a hydrogen-containing gas in the hydrodesulfurizer 1 is supplied by supplying the fuel gas to the hydrodesulfurizer 1 through the recycle gas path 6. Sulfur compounds can be removed using gas.

  However, if the fuel gas cannot be normally supplied to the hydrodesulfurizer 1 through the recycle gas path 6, the hydrodesulfurizer 1 will perform adsorption removal of physical sulfur compounds, and the hydrodesulfurizer 1 The hydrodesulfurization catalyst contained deteriorates faster than expected, and the hydrodesulfurizer 1 does not function. As a result, there is a possibility that a device using the fuel gas generated by the reformer 4 or the hydrogen generator 100 is deteriorated.

  In order to prevent such a situation, it is necessary to normally supply the fuel gas to the hydrodesulfurizer 1 through the recycle gas path 6.

  Here, if the flow rate of the fuel gas produced by the hydrogen generator 100 is to be increased or decreased, the supply flow rate of the raw material gas that is the source of the fuel gas must also be increased or decreased. When the flow rate of the fuel gas that must be generated decreases, the flow rate of the raw material gas supplied to the hydrogen generator 100 also decreases.

  When the raw material gas flow rate decreases, the raw material gas flow rate flowing through the ejector 7 also decreases, the venturi effect at the ejector 7 decreases, and the recycle gas flow rate sucked through the recycle gas path 6 also decreases.

  If the raw material gas flow rate falls below the predetermined flow rate, the venturi effect at the ejector 7 cannot be sufficiently exerted, and the recycle gas cannot be sucked through the recycle gas path 6. If it becomes so, it will become impossible to supply the gas containing hydrogen with respect to the hydrodesulfurizer 1, and it will become a removal of a physical sulfur compound instead of hydrodesulfurization, and will deteriorate a hydrodesulfurization catalyst.

  In order to prevent such a problem when the raw material gas flow rate is reduced, the raw material circulation path 8 is used to increase the gas flow rate flowing through the ejector 7 more than the raw material gas flow rate supplied to the hydrogen generator 100.

  The raw material circulation path 8 branches from between the ejector 7 and the hydrodesulfurizer 1, is connected to the upstream side of the flow of the raw material gas from the raw material supplier 3, and is supplied from the ejector 7 to the hydrodesulfurizer 1. It is a path | route comprised so that a part of may be supplied to the raw material supply device 3.

  The upstream side of the raw material supply unit 3 with respect to the flow of the raw material gas is a low pressure gas supplied from a raw material gas infrastructure or the like, and the low pressure raw material gas is pressurized by the raw material supply unit 3 to generate hydrogen. It is possible to overcome the flow path resistance of the devices connected to the apparatus 100 and the hydrogen generation apparatus 100 and to distribute the raw material gas and the fuel gas.

  Therefore, the gas pressure between the ejector 7 and the hydrodesulfurizer 1 can be designed to be higher than the raw material gas pressure on the upstream side of the raw material supplier 3. With such a design, the gas branched from between the ejector 7 and the hydrodesulfurizer 1 can be supplied from the raw material supplier 3 to the upstream side of the flow of the raw material gas.

  As described above, the gas branched from between the ejector 7 and the hydrodesulfurizer 1 is supplied to the upstream side of the flow of the raw material gas from the raw material supplier 3 through the raw material circulation path 8, and thus circulates to the ejector 7. The gas flow rate can be increased, the gas suction capability by the venturi effect in the ejector 7 is improved, and the recycle gas flow rate through the recycle gas path 6 can be increased.

[First Modification]
FIG. 2 is a block diagram showing an example of a schematic configuration of the hydrogen generator in the first modification of the first embodiment of the present invention.

  As shown in FIG. 2, in this modification, the raw material circulation path 8 is provided with an on-off valve 9.

  With this configuration, the gas can be circulated through the raw material circulation path 8 only when the raw material gas flow rate supplied to the hydrogen generator 100 is small. When the raw material gas flow rate is large, the on-off valve 9 is closed to close the raw material circulation path. The gas circulation through 8 can be stopped, and the flow rate of the recycle gas flowing through the recycle gas path 6 can be stabilized.

  The hydrogen generator 100 of this modification may be configured in the same manner as in the first embodiment except for the above features.

  The on-off valve 9 is a valve provided in the raw material circulation path 8. The on-off valve 9 is closed to stop the gas flow in the raw material circulation path 8, or the on-off valve 9 is opened to open the raw material circulation path 8. Or start the gas flow inside. The on-off valve 9 may be driven by electric power like an electromagnetic valve, or may be driven by gas pressure. Any configuration may be used as long as the gas path in the raw material circulation path 8 can be closed or opened.

  When the flow rate of the raw material gas supplied to the hydrogen generator 100 is higher than a predetermined flow rate, it is necessary for the hydrodesulfurization in the hydrodesulfurizer 1 due to the venturi effect that occurs when the flow rate of the raw material gas flows to the ejector 7. Since it is possible to secure a recycle gas flow rate, it is not necessary to circulate the gas in the material circulation path 8, and the on-off valve 9 is closed. This prevents excessive fuel gas from flowing through the recycle gas path 6.

  If excessive fuel gas flows through the recycling path, the hydrodesulfurization catalyst of the hydrodesulfurizer 1 deteriorates due to the influence of water vapor contained in the fuel gas, and it becomes necessary to accumulate more hydrodesulfurization catalysts. And may increase the volume of equipment. Further, if the configuration is such that the water vapor in the recycle gas is removed, an apparatus for removing the water vapor is required, leading to an increase in cost.

When the flow rate of the raw material gas supplied to the hydrogen generator 100 is equal to or lower than the predetermined flow rate, only the venturi effect that occurs when the raw material gas flow rate flows to the ejector 7 is necessary for the hydrodesulfurization in the hydrodesulfurizer 1. Since the recycle gas flow rate cannot be secured, the on-off valve 9 is opened in order to circulate the gas in the raw material circulation path 8. As a result, the recycle gas necessary for the hydrodesulfurization in the hydrodesulfurizer 1 can be circulated through the recycle gas path 6.

  The determination of opening / closing the on-off valve 9 may be the flow rate of the raw material gas supplied to the hydrogen generator 100 or the flow rate of the fuel gas flowing through the recycle gas path 6. As long as the flow rate of the fuel gas flowing through can be ensured, it may be anything.

(Embodiment 2)
FIG. 3 is a block diagram showing an example of a schematic configuration of the hydrogen generator according to Embodiment 2 of the present invention.

  In the example shown in FIG. 3, the hydrogen generator 100 according to the present embodiment includes a hydrodesulfurizer 1, a raw material supply path 2, a raw material supply apparatus 3, a reformer 4, a fuel gas path 5, and a recycling. A gas path 6, a first junction part, an ejector 7, a raw material circulation path 8, an on-off valve 9, a second junction part 10, and a controller 11 are provided.

  In the configuration of the hydrogen generator 100 of the present embodiment shown in FIG. 3, the hydrodesulfurizer 1, the raw material supply path 2, the raw material supply apparatus 3, the reformer 4, the fuel gas path 5, the recycle gas path 6, the first The merging section, the ejector 7, the raw material circulation path 8, and the on-off valve 9 are the same as those in the first modification of the first embodiment, and thus description thereof is omitted.

  The second joining unit 10 is a part where the material circulation path 8 joins the material supply path 2. The raw material gas flowing through the raw material supply path 2 and the mixed gas of the raw material gas and fuel gas flowing through the raw material circulation path 8 are merged and mixed in the second merging section 10.

  The controller 11 is a device that controls the on-off valve 9 based on the flow rate of the raw material gas in the raw material supply path 2 supplied to the second junction 10. For example, the on-off valve 9 is closed when the flow rate of the raw material gas in the raw material supply path 2 supplied to the second junction 10 is higher than a predetermined flow rate, and the open / close valve 9 is opened when the flow rate is lower than the predetermined flow rate. The flow rate of the fuel gas flowing through the recycle gas path 6 is ensured.

  As long as the flow rate of the fuel gas flowing through the recycle gas path 6 can secure a flow rate necessary for removing sulfur compounds in the raw material gas in the hydrodesulfurizer 1, the open / close valve 9 can be opened or closed in any condition. I do not care.

  The controller 11 only needs to have a control function, and includes an arithmetic processing unit (not shown) and a storage unit (not shown) that stores a control program. Examples of the arithmetic processing unit include an MPU and a CPU. An example of the storage unit is a memory. The controller 11 may be composed of a single controller that performs centralized control, or may be composed of a plurality of controllers that perform distributed control in cooperation with each other.

  The operation and action of the hydrogen generator 100 of the present embodiment configured as described above will be described below.

  Since the operation of the hydrogen generation apparatus 100 of the present embodiment is the same as that of the hydrogen generation apparatus 100 of the first embodiment and the first modification of the first embodiment, the operation of the hydrogen generation apparatus 100 of the present embodiment is the same. Features will be described with reference to FIG.

  As shown in FIG. 3, the flow rate of the raw material gas supplied to the hydrogen generator 100 is the same as the flow rate of the raw material gas in the raw material supply path 2 supplied to the second junction 10.

  In order to measure the flow rate of the raw material gas in the raw material supply path 2 supplied to the second merging section 10, a flow meter for the raw material gas is installed in the raw material supply path 2 supplied to the second merging section 10. It does not matter (not shown), and a flow meter capable of measuring the flow rate of the source gas supplied to the hydrogen generator 100 may be installed (not shown). Further, the raw material gas flow rate may be detected by any method without using a flow meter.

  Based on the flow rate of the raw material gas, it is determined whether the required flow rate of the fuel gas through the recycle gas path 6 in the ejector 7 flows, and the open / close valve 9 is opened and distributed to the ejector 7 so as not to run short. The amount of fuel gas flowing through the recycle gas path 6 is increased by increasing the gas flow rate. If the required flow rate of the fuel gas flowing through the recycle gas path 6 can be secured even when the on-off valve 9 is closed, the on-off valve 9 is closed.

  On the basis of the flow rate of the raw material gas supplied to the hydrogen generator 100, the on-off valve 9 is opened and closed, and the flow rate of the fuel gas flowing through the recycle gas path 6 is appropriately controlled to perform hydrodesulfurization in the hydrodesulfurizer 1. Any method may be used as long as a necessary hydrogen gas flow rate can be secured.

  The flow rate of the source gas supplied to the hydrogen generator 100 is the detected flow rate of a flow meter (hereinafter referred to as a fourth flow meter) provided upstream from the flow of the source gas from the second junction 10. The adjustment may be made by controlling the raw material supplier 3. The fourth flow meter may be the same as the raw material gas flow meter for determining the opening / closing of the on-off valve 9 in the present embodiment, or may be separately installed.

[First Modification]
FIG. 4 is a block diagram showing an example of a schematic configuration of the hydrogen generator in the first modification of the second embodiment of the present invention.

  As shown in FIG. 4, in this modification, a raw material supply amount detection means for detecting the flow rate of the raw material gas in the raw material supply path 2 supplied to the second junction 10 where the raw material circulation path 8 joins the raw material supply path 2. (The first flow meter 12 in FIG. 4), and if the flow rate of the raw material gas detected by the raw material supply amount detection means (the first flow meter 12 in FIG. 4) is equal to or lower than the first predetermined value, the controller 11 Control is performed to open the on-off valve 9.

  With this configuration, the gas can be circulated through the raw material circulation path 8 only when the raw material gas flow rate supplied to the hydrogen generator 100 is small, and the recycle gas flow rate flowing through the recycle gas path 6 can be stabilized.

  The hydrogen generator 100 of this modification may be configured in the same manner as in the second embodiment except for the above features.

  The raw material supply amount detection means detects the flow rate of the raw material gas in the raw material supply path 2 supplied to the second junction 10 where the raw material circulation path 8 joins the raw material supply path 2. Any means can be used as long as the flow rate of the source gas can be detected. For example, there are means for detecting the flow rate such as a differential pressure type, a hot wire type, an ultrasonic type, and a turbine type. In the present embodiment, the first flow meter 12 is installed as the raw material supply amount detection means.

Here, the part where the raw material supply amount detection means detects the gas flow rate is the raw material supply path 2 upstream of the flow of the raw material gas from the second junction 10 where the raw material circulation path 8 joins the raw material supply path 2. The raw material supply path 2 may be the downstream of the raw material gas flow from the branch portion where the raw material supply path 2 branches from the raw material supply path 2, and from the hydrodesulfurizer 1 to the reformer 4. The fuel gas path 5 from the reformer 4 to the recycle gas path 6 may be used, or the fuel gas path 5 after the recycle gas path 6 is branched. It does not matter.

  Although the gas flowing in each part is different, the controller 11 opens and closes the on-off valve 9 with a flow rate suitable for each part as a threshold value, and the flow rate of the fuel gas flowing through the recycle gas path 6 is changed to the raw material gas flow rate. On the other hand, the flow rate may be measured at any part as long as it can be appropriately controlled.

  The gas flowing in each part is as follows.

  The raw material gas supplied to the hydrogen generator 100 flows in the raw material supply path 2 upstream of the flow of the raw material gas from the second joining portion 10 where the raw material circulation path 8 joins the raw material supply path 2, and the raw material supply path 2, a mixed gas of the source gas supplied to the hydrogen generator 100 and the fuel gas flowing in the recycle gas path 6 flows in the source supply path 2 downstream of the source gas flow from the branch portion where the source circulation path 8 branches. ing.

  In the raw material gas path from the hydrodesulfurizer 1 to the reformer 4, a mixed gas of the raw material gas supplied to the hydrogen generator 100 and the fuel gas flowing through the recycle gas path 6 flows. A mixed gas of the source gas supplied to the hydrogen generator 100 and the fuel gas flowing through the recycle gas path 6 flows through the fuel gas path 5 from the reformer 4 to the recycle gas path 6.

  In the fuel gas path 5 after branching the recycle gas path 6, the flow rate of the fuel gas flowing in the recycle gas path 6 from the mixed gas of the source gas supplied to the hydrogen generator 100 and the fuel gas flowing in the recycle gas path 6 The mixed gas with reduced flow.

  In FIG. 4, as an example, a schematic configuration in the case where the first flow meter 12 is installed in the raw material supply path 2 upstream of the flow of the raw material gas from the second joining portion 10 where the raw material circulation path 8 joins the raw material supply path 2 is shown. It is shown, and the case where the first flow meter 12 is installed in other parts is not shown.

  FIG. 5 is a flowchart showing an example of an operation method of the hydrogen generator in the first modification of the second embodiment of the present invention.

  FIG. 5 shows an example of conditions for opening and closing the on-off valve 9. The flow rate detected by the first flow meter 12 is compared with a first predetermined value (S 301), and the detected flow rate of the first flow meter 12 is If it is 1 or less, the on-off valve 9 is opened (S302). If the detected flow rate of the first flow meter 12 is not less than the first predetermined value, the on-off valve 9 is closed (S303).

  The first predetermined value may be set so that the gas flow rate flowing to the ejector 7 can be secured so that the recycle gas flow rate can be sufficiently secured with respect to the raw material gas flow rate supplied to the hydrodesulfurizer 1. Any value can be used as long as stable hydrodesulfurization can be performed. Moreover, since the first predetermined value varies depending on the installation site of the first flow meter 12, it is necessary to set the first predetermined value optimally for each site.

  Further, the condition for opening and closing the on-off valve 9 does not necessarily have to be the same first predetermined value. For example, the condition for opening the on-off valve 9 is equal to or less than the first predetermined value, but the condition for closing the on-off valve 9 May be greater than or equal to a value greater than the first predetermined value.

  Since the flow rate of the gas flowing through the first flow meter 12 varies depending on the open / close state of the open / close valve 9 depending on the installation site of the first flow meter 12, the open / close valve 9 can be repeatedly opened and closed by controlling the open / close valve 9 only with the first predetermined value. There is sex. Therefore, it is preferable to set the opening / closing conditions of the opening / closing valve 9 according to the installation site of the first flow meter 12.

  Note that the flow control of the raw material gas supplied to the hydrogen generator 100 may control the raw material supplier 3 based on the flow rate detected by the first flow meter 12. In addition, a flow meter may be separately installed for controlling the flow rate of the source gas supplied to the hydrogen generator 100.

(Embodiment 3)
The configuration of the hydrogen generator of the present embodiment is the same as that of the hydrogen generator 100 of the second embodiment shown in FIG.

  The operation and action of the hydrogen generator 100 of the present embodiment configured as described above will be described below.

  In order to control the on-off valve 9 based on the flow rate of the raw material gas flowing through the ejector 7, an ejector flow rate detecting means (not shown) for detecting the flow rate of the raw material gas flowing through the ejector is provided. As the ejector flow rate detection means, flow meters may be installed before and after the ejector 7, or the flow rate may be detected from the output of the raw material supplier 3.

  As a method of detecting the flow rate from the output of the raw material supplier 3, the supply gas flow rate is estimated from the operation capability, power consumption, command voltage, manipulated variable, etc. of the raw material supplier 3. Further, if the raw material supplier 3 is a constant displacement pump, the flow rate can be directly detected. The ejector flow rate detecting means may be any means as long as the gas flow rate flowing through the ejector 7 can be detected.

  If the flow rate of the raw material gas flowing through the ejector 7 detected by the ejector flow rate detecting means is equal to or less than the second predetermined value, the controller 11 controls to open the on-off valve 9.

  Here, the second predetermined value is used to determine whether or not the recycle gas suction capacity of the ejector 7 can be higher than the recycle gas flow rate required for the hydrodesulfurizer 1, and the recycle gas flow rate is necessary. Before the flow rate drops below the flow rate, it is necessary to open the on-off valve 9 to improve the recycle gas suction capability. The second predetermined value may be any value as long as stable hydrodesulfurization can be performed in the hydrodesulfurizer 1.

  The condition for closing the on-off valve 9 may be that the gas flow rate detected by the ejector flow rate detecting means is not less than the second predetermined value, or a threshold value exceeding the second predetermined value may be provided. Since the flow rate of the gas flowing through the ejector 7 also changes depending on the open / close state of the open / close valve 9, a threshold value exceeding the second predetermined value is set as the close condition of the open / close valve 9 so that the open / close valve 9 does not continue to open and close repeatedly. Is desirable.

  The hydrogen generator 100 according to the present embodiment may be configured in the same manner as in the first embodiment, the first modification of the first embodiment, and the second embodiment except for the above characteristics.

[First Modification]
FIG. 6 is a block diagram showing an example of a schematic configuration of the hydrogen generator in the first modification of Embodiment 3 of the present invention.

  As shown in FIG. 6, in this modification, the ejector flow rate detection means includes a second junction 10 where the material circulation path 8 merges with the material supply path 2, and the material circulation path 8 branches from the material supply path 2. It is the 2nd flow meter 13 arrange | positioned at the raw material supply path | route 2 between a branch part.

  With this configuration, the gas flow rate flowing through the ejector 7 can be detected by the second flow meter 13, and the on-off valve 9 can be controlled according to the gas flow rate detected by the second flow meter 13. Become.

  In the hydrogen generator of this modification, except for the above features, the same as the first embodiment, the first modification of the first embodiment, the second embodiment, the first modification of the second embodiment, and the third embodiment. You may comprise.

  The second flow meter 13 is disposed in the raw material supply path 2 between the second junction 10 where the raw material circulation path 8 joins the raw material supply path 2 and the branch where the raw material circulation path 8 branches from the raw material supply path 2. Flow meter. By installing the second flow meter 13 at this site, it becomes possible to directly measure the flow rate of the gas flowing through the ejector 7.

  The installation position of the second flow meter 13 may be between the raw material supplier 3 and the ejector 7. Since the flowing gas in each part differs depending on whether or not it contains the recycle gas, the on-off valve 9 may be controlled with a second predetermined value corresponding to each part.

  The second flow meter 13 may have any configuration as long as it can detect the gas flow rate flowing through the ejector 7, such as a differential pressure type, a hot wire type, an ultrasonic type, a turbine type, etc. There is a means to detect the flow rate.

  In addition, about control of the on-off valve 9, since it is the same as Embodiment 3, it abbreviate | omits.

[Second Modification]
FIG. 7 is a block diagram showing an example of a schematic configuration of the hydrogen generator in the second modification of the third embodiment of the present invention.

  As shown in FIG. 7, in the present modification, a pressure gauge 14 that detects the differential pressure on the inlet side and the outlet side of the ejector 7 is provided as the ejector flow rate detection means. If the detected differential pressure is equal to or less than a third predetermined value set in advance, control is performed to open the on-off valve 9.

  With this configuration, the gas flow rate flowing through the ejector 7 can be detected from the differential pressure detected by the pressure gauge 14, and the on-off valve 9 can be controlled according to the detected pressure of the pressure gauge 14. It becomes.

  In the hydrogen generator 100 of the present modification, except for the above features, the first embodiment, the first modification of the first embodiment, the second embodiment, the first modification of the second embodiment, the third embodiment, You may comprise similarly to the hydrogen generator 100 of the 1st modification of Embodiment 3. FIG.

  The pressure gauge 14 detects a differential pressure between the inlet side and the outlet side of the ejector 7. Any configuration can be used as long as the pressure difference can be detected.

The ejector 7 has a narrowed gas flow path in order to exert a venturi effect. Therefore, when the gas flows through the ejector, the pressure held by the gas decreases due to the flow path resistance. This pressure drop increases as the flow rate of gas flowing through the flow path increases with respect to the same flow path, and decreases as the flow rate decreases.

  Therefore, by detecting the pressure difference between the inlet side and the outlet side of the ejector 7 with the pressure gauge 14, it is possible to detect the flow rate of gas flowing through the ejector. Based on this gas flow rate, it can be determined whether the fuel gas necessary for hydrodesulfurization in the hydrodesulfurizer 1 can be supplied through the recycle gas path 6. Therefore, it is possible to control the opening / closing of the on-off valve 9 from the differential pressure detected by the pressure gauge 14.

  If the detected pressure of the pressure gauge 14 is equal to or lower than the third predetermined value, the controller 11 opens the on-off valve 9 in order to secure the flow rate of the recycle gas supplied to the hydrodesulfurizer 1. The second predetermined value may be any value as long as hydrodesulfurization in the hydrodesulfurizer 1 can be maintained.

  The condition for closing the on-off valve 9 may be when the pressure detected by the pressure gauge 14 exceeds the second predetermined value, or by setting a predetermined threshold value that is larger than the second predetermined value. For example, the on-off valve 9 may be closed.

  Since the flow rate of the gas flowing through the ejector 7 varies due to the opening / closing of the opening / closing valve 9, a condition for closing the opening / closing valve 9 is set so that the opening / closing operation of the opening / closing valve 9 does not continue to be repeated due to the variation. It is desirable. For example, when the on-off valve 9 is opened, the flow rate of gas flowing through the ejector 7 increases compared to when the on-off valve 9 is closed, so that the pressure value detected by the pressure gauge 14 also increases.

  Therefore, if the threshold value for opening and closing the on-off valve 9 is the same, the pressure detected by the pressure gauge 14 exceeds the threshold value by simply changing the on-off valve 9 from the closed state to the open state, and the on-off valve 9 is immediately closed. There is a possibility. Therefore, it is preferable to set a threshold value for closing the on-off valve 9 so as to be larger than the second predetermined value more than the fluctuation of the value of the pressure gauge 14 accompanying the operation of the on-off valve 9.

(Embodiment 4)
FIG. 8 is a block diagram showing an example of a schematic configuration of the hydrogen generator in Embodiment 4 of the present invention.

  In the example shown in FIG. 8, the hydrogen generator 100 of the present embodiment includes a hydrodesulfurizer 1, a raw material supply path 2, a raw material supply apparatus 3, a reformer 4, a fuel gas path 5, and a recycling. A gas path 6, a first junction, an ejector 7, a raw material circulation path 8, an on-off valve 9, a second junction 10, a controller 11, a recycled gas passage flow rate detecting means, a third A flow meter 15.

  In the configuration of the hydrogen generator 100 of the present embodiment shown in FIG. 8, the hydrodesulfurizer 1, the raw material supply path 2, the raw material supplier 3, the reformer 4, the fuel gas path 5, the recycle gas path 6, the first About 1 junction part, the ejector 7, the raw material circulation path 8, the on-off valve 9, the 2nd junction part 10, and the controller 11, Embodiment 1 and its modification, Embodiment 2, and its modification, Embodiment 3 And since it is the same as that of the modification, the overlapping description is omitted.

  The recycle gas passage flow rate detecting means detects the flow rate of the fuel gas flowing through the recycle gas path 6. Any device may be used as long as it can detect the flow rate of the fuel gas. In the present embodiment, the third flow meter 15 that is a flow meter is used as the recycled gas flow path flow rate detecting means. Examples of the flow meter include means for detecting a flow rate such as a differential pressure type, a hot wire type, an ultrasonic type, and a turbine type.

The hydrogen generator 100 of the present embodiment is the hydrogen generator 1 of any one of the first embodiment and its modification, the second embodiment and its modification, the third embodiment and its modification, except for the above features.
You may comprise similarly to 00.

  The operation and action of the hydrogen generator 100 of the present embodiment configured as described above will be described below.

  The operation of the hydrogen generator 100 of the present embodiment is the same as that of the first embodiment, the first modification of the first embodiment, the second embodiment, the first modification of the second embodiment, the third embodiment, and the second embodiment. Since the operation is the same as that of the hydrogen generator 100 of the first modification of the third embodiment and the second modification of the third embodiment, the features of the hydrogen generator 100 of the present embodiment will be described with reference to FIG. .

  As shown in FIG. 8, the flow rate of the fuel gas flowing through the recycle gas path 6 is detected by a third flow meter that is the recycle gas path flow rate detecting means 18, and the on-off valve 9 is controlled based on the flow rate.

  The third flow rate indicates whether the flow rate of fuel gas supplied from the recycle gas path 6 satisfies the flow rate required for hydrodesulfurization in the hydrodesulfurizer 1 with respect to the flow rate of raw material gas supplied to the hydrogen generator 100. Judgment can be made by checking the flow rate detected by the meter.

  If the flow rate of the fuel gas supplied from the recycle gas path 6 is reduced, the on-off valve 9 is opened before the fuel gas flow rate becomes insufficient, and the flow rate of the fuel gas supplied from the recycle gas path 6 is increased.

  As a condition for opening the on-off valve 9, a fourth predetermined value is set. When the flow rate of the fuel gas supplied from the recycle gas path 6 becomes equal to or lower than the fourth predetermined value, the controller 11 opens the on-off valve 9. The fourth predetermined value may be any value as long as the flow rate of the fuel gas supplied from the recycle gas path 6 is not insufficient and can be stably supplied.

  Further, the fourth threshold value may be varied depending on the flow rate of the source gas supplied to the hydrogen generator 100.

  Further, the condition for closing the on-off valve 9 may be when the flow rate detected by the third flow meter exceeds the fourth predetermined value, or even when a threshold value greater than the fourth predetermined value is provided and exceeded. I do not care. Since the flow rate detected by the third flow meter varies depending on whether the on-off valve 9 is open or closed, it is preferable to set conditions for opening the on-off valve 9 so that the on-off valve 9 does not continue to open and close repeatedly.

(Embodiment 5)
FIG. 9 is a block diagram showing an example of a schematic configuration of a fuel cell system according to Embodiment 5 of the present invention.

  In the example shown in FIG. 9, the fuel cell system 200 of the present embodiment includes the first embodiment, the first modification of the first embodiment, the second embodiment, the first modification of the second embodiment, and the implementation. The hydrogen generation device 100 according to any one of the third embodiment, the first modification of the third embodiment, the second modification of the third embodiment, and the fourth embodiment, and the fuel cell 16 are provided.

  The fuel cell 16 may be any type of fuel cell as long as it generates electricity using a fuel gas containing hydrogen supplied from the hydrogen generator 100. For example, a solid polymer fuel cell, A polymer electrolyte fuel cell, a solid oxide fuel cell, a phosphoric acid fuel cell, or the like can be used.

  During the power generation operation, the fuel cell system 200 generates power using the hydrogen-containing gas supplied from the hydrogen generator 100. The operation of the hydrogen generator 100 in the present embodiment is the same as that of the fuel cell 16, in the first modification, the first modification of the first embodiment, the second modification, the first modification of the second embodiment, and the like. If it considers it as the hydrogen utilization apparatus which uses the hydrogen containing gas produced | generated from the hydrogen generator 100 of the form 3, the 1st modification of Embodiment 3, the 2nd modification of Embodiment 3, or Embodiment 4. First Embodiment, First Modification of First Embodiment, Second Embodiment, First Modification of Second Embodiment, Third Embodiment, First Modification of Third Embodiment, Third Embodiment This is the same as the second modification of the fourth embodiment. Therefore, detailed description is omitted.

  From the foregoing description, many modifications and other embodiments of the present invention are apparent to persons skilled in the art. Accordingly, the foregoing description should be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode of carrying out the invention. The details of the structure and / or function may be substantially changed without departing from the spirit of the invention.

  As described above, the present invention is a recycling system that circulates a recycle gas path in a hydrogen generator that sucks a hydrogen-containing gas from a recycle gas path by an ejector provided in a path for supplying a raw material gas to a hydrodesulfurizer. Since it is possible to remove sulfur compounds stably without a shortage of gas flow and to realize an operation with improved reliability, an ejector provided in the path for supplying the raw material gas to the hydrodesulfurizer The present invention is useful for a hydrogen generator that sucks a hydrogen-containing gas from a recycle gas path and a fuel cell system including the hydrogen generator.

DESCRIPTION OF SYMBOLS 1 Hydrodesulfurizer 2 Raw material supply path 3 Raw material supply apparatus 4 Reformer 5 Fuel gas path 6 Recycle gas path 7 Ejector 8 Raw material circulation path 9 On-off valve 10 2nd junction part 11 Controller 12 1st flow meter 13 2nd Flow meter 14 Pressure gauge 15 Third flow meter 16 Fuel cell 100 Hydrogen generator 200 Fuel cell system

Claims (16)

A hydrodesulfurizer that reacts and removes sulfur compounds in the raw material gas with hydrogen; a raw material supply path that supplies the raw material gas to the hydrodesulfurizer; and the raw material supply path that is disposed in the raw material gas, A raw material supplier that supplies the desulfurizer, a reformer that reforms the raw material gas that has passed through the hydrodesulfurizer to generate a fuel gas containing hydrogen, and a fuel gas that discharges the fuel gas from the reformer And a branch from the fuel gas path, merged with the raw material supply path downstream of the raw material gas flow from the raw material supplier, and a part of the fuel gas discharged from the reformer becomes the raw material gas Recycle gas path to be mixed, an ejector disposed in a first junction where the raw material supply path and the recycle gas path merge, and a branch from between the ejector and the hydrodesulfurizer to supply the raw material Of raw material gas flow It is connected to the flow side, the part of the raw material gas and a raw material circulation path configured to supply to the raw material supplier, the hydrogen generator. The hydrogen generator according to claim 1, further comprising an on-off valve in the raw material circulation path. The on-off valve is controlled based on the flow rate of the raw material gas in the raw material supply path supplied to the on-off valve disposed in the raw material circulation path and the second junction where the raw material circulation path joins the raw material supply path. A hydrogen generator according to claim 1, comprising a controller. The raw material circulation path includes a raw material supply amount detection means for detecting the flow rate of the raw material gas in the raw material supply path supplied to the second joining portion that joins the raw material supply path, and is detected by the raw material supply amount detection means. The hydrogen generator according to claim 3, wherein the controller controls the open / close valve to be opened if the flow rate of the source gas is equal to or less than a first predetermined value. The raw material supply amount detection means is configured such that the raw material supply path is upstream of the flow of the raw material gas from the second junction where the raw material circulation path joins the raw material supply path, or the raw material supply path is branched from the raw material supply path. The raw material supply path downstream of the flow of the raw material gas from the branching section, the raw material gas path from the hydrodesulfurizer to the reformer, or the reformer branches to the recycle gas path 6. The hydrogen generator according to claim 4, wherein the hydrogen generator is a first flow meter arranged in the fuel gas path up to or after the recycle gas path is branched. 2. The hydrogen generator according to claim 1, comprising: an on-off valve disposed in the raw material circulation path; and a controller that controls the on-off valve based on a flow rate of the raw material gas flowing through the ejector. Ejector flow rate detection means for detecting the flow rate of the raw material gas flowing through the ejector, and if the flow rate of the raw material gas detected by the ejector flow rate detection means is equal to or less than a second predetermined value, the controller The hydrogen generator according to claim 6, wherein the on / off valve is controlled to open. 8. The hydrogen generator according to claim 7, wherein an output of the raw material supplier is used for the ejector flow rate detecting means. The ejector flow rate detecting means is disposed in a raw material supply path between a second junction where the raw material circulation path merges with the raw material supply path and a branch where the raw material circulation path branches from the raw material supply path. The hydrogen generator according to claim 7, wherein the second flow meter is a second flow meter. The ejector flow rate detecting means includes a pressure gauge that detects a differential pressure on the inlet side and the outlet side of the ejector, and the controller is configured to set a differential pressure detected by the pressure gauge to a third predetermined value. The hydrogen generator according to claim 7, wherein if it is equal to or less than the value, control is performed to open the on-off valve. 2. The hydrogen generator according to claim 1, comprising: an on-off valve disposed in the raw material circulation path; and a controller that controls the on-off valve based on a flow rate of fuel gas flowing through the recycle gas path. . Recycle gas path flow rate detection means for detecting the flow rate of fuel gas flowing through the recycle gas path is provided, and if the flow rate of fuel gas detected by the recycle gas path flow rate detection means is equal to or less than a fourth predetermined value The hydrogen generator according to claim 11, wherein the controller controls to open the on-off valve. The hydrogen generation apparatus according to claim 12, wherein the recycle gas path flow rate detecting means is a third flow meter arranged in the recycle gas path. The hydrogen generator according to claim 5, wherein the controller controls the raw material supplier based on a flow rate detected by the first flow meter. The raw material circulation path includes a fourth flow meter arranged in the raw material supply path upstream of the flow of the raw material gas from the second merging portion where the raw material supply path merges, and the controller includes the fourth flow meter. The hydrogen generator according to claim 1, wherein the raw material supplier is controlled based on a detected flow rate. A fuel cell system comprising: the hydrogen generator according to any one of claims 1 to 15; and a fuel cell that generates power using fuel gas supplied from the hydrogen generator.

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