JP2004292293A - Apparatus for generating hydrogen and method of its operation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the working efficiency by reducing the time and energy needed for starting and stopping by suppressing complication of the system constitution. <P>SOLUTION: A starting catalytic combustor 25 is packed with a combustion catalyst inside and burns an off-gas containing combustible gases such as hydrogen and carbon monoxide, which are supplied from an off-gas tank 36 of a pressure-swing adsorption (PSA) apparatus 12, with the air supplied from an air blower 26 in starting the operation of the apparatus 10 for generating hydrogen. The resulting combustion heat is supplied through the combustion gas to a reformer 22 to warm up the reformer 22. When the operation of the apparatus 10 for generating hydrogen is stopped, the operations of the reforming apparatus 11 and the PSA apparatus 12 are stopped after the pressure corresponding to the quantity of the off-gas needed for starting the reformer 22 and an evaporator 21 up to the operational conditions required in the next starting is secured in the off-gas tank 36. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a hydrogen generator and a method for operating the hydrogen generator.
[0002]
[Prior art]
Conventionally, for example, as in a solid polymer membrane fuel cell including a stack formed by stacking a plurality of cells formed by sandwiching a solid polymer electrolyte membrane between a fuel electrode (anode) and an oxygen electrode (cathode) from both sides. At the same time, hydrogen is supplied as fuel to the fuel electrode, air is supplied to the oxygen electrode as an oxidant, and hydrogen ions generated by a catalytic reaction at the fuel electrode move through the solid polymer electrolyte membrane to the oxygen electrode, 2. Description of the Related Art Fuel cells that generate an electric power by causing an electrochemical reaction with oxygen at an oxygen electrode are known.
A fuel provided with a reformer that generates hydrogen supplied as a fuel to such a fuel cell from a liquid fuel containing hydrocarbons (for example, methanol or gasoline) or a gaseous fuel (for example, methane or ethane). Battery systems are known.
[0003]
Then, at the time of starting such a fuel cell system, as a warm-up operation for raising the temperature of the reforming catalyst provided in the reformer to a predetermined catalyst activation temperature, for example, starting fuel such as methanol in a starting combustor is used. There is known a method of burning and supplying this combustion heat to a reformer via a combustion gas (for example, see Patent Document 1).
In addition, as a start-up operation of the fuel cell system, for example, air and a fuel such as methanol are supplied at a predetermined theoretical mixing ratio to a catalytic combustor arranged upstream of the reformer, for example, and the catalytic combustion is performed by self-ignition. A method in which an excess amount of liquid fuel is supplied to a catalytic combustor to evaporate it, and a raw material gas for reforming obtained by mixing steam is supplied to the reformer (for example, see Patent Document 2). )It has been known.
[0004]
[Patent Document 1]
JP 2000-323163 A
[Patent Document 2]
JP 2000-191304 A
[0005]
[Problems to be solved by the invention]
However, in the method according to the prior art, if the starting fuel such as methanol is directly combusted, the combustion temperature becomes excessively high and the nitrogen oxides (NO _X ) Is increased.
Further, in the catalytic combustor, catalytic combustion of fuel such as methanol does not occur at normal temperature, and therefore, as described above, a device for mixing air and fuel at a predetermined theoretical mixing ratio, or increasing the temperature of the catalyst is used. For this purpose, a special device such as an electric heater is required, which complicates the configuration of the device and increases the cost and power consumption required for the device configuration. In addition, when the temperature of the catalyst in the catalytic combustor is not properly raised, unburned fuel and carbon monoxide are discharged.
The present invention has been made in view of the above circumstances, and a hydrogen generator capable of improving operation efficiency by reducing the time and energy required for starting and stopping while suppressing the device configuration from becoming complicated. An object of the present invention is to provide a method for operating a hydrogen generator.
[0006]
[Means for Solving the Problems]
In order to solve the above-mentioned problems and achieve the above object, a hydrogen generator according to the present invention according to claim 1 reforms a raw fuel containing hydrogen into a hydrogen-rich reformed gas by a reforming reaction. A hydrogen generator comprising a device and a pressure swing adsorption device that separates and purifies purified hydrogen gas by a pressure swing adsorption method from the reformed gas generated by the reformer, wherein the pressure swing adsorption device comprises: An adsorption tower that adsorbs impurities other than hydrogen in the reformed gas; and a reformed gas supply unit that pressurizes the reformed gas generated by the reformer and supplies the reformed gas to the adsorption tower (for example, as described below). A PSA compressor 31) according to the embodiment, and an off-gas tank for storing an off-gas obtained by desorbing the impurities adsorbed in the adsorption tower into the purified hydrogen gas. A starting catalyst combustor (for example, a starting catalyst combustor 25 in an embodiment described later) that includes a combustion catalyst capable of burning the off-gas and warms up the reformer when the hydrogen generator starts. It is characterized by having.
[0007]
According to the hydrogen generator having the above configuration, the off-gas supplied from the off-gas tank to the starting catalytic combustor includes a flammable gas such as hydrogen or carbon monoxide, such as an electric heater for warming up the starting catalytic combustor. It is possible to cause off-gas catalytic combustion without requiring a special device, and to surely warm up the reformer while preventing the device configuration from becoming complicated.
Thereby, for example, compared with a case where a hydrocarbon fuel such as methanol is burned in a starting catalytic combustor from the beginning of the start of the hydrogen generator, for example, nitrogen oxides (NO _X ) And the emission of unburned fuel and carbon monoxide.
Moreover, since the combustible range with respect to the mixing ratio with air is relatively wide as compared with, for example, a hydrocarbon fuel such as methanol, the off-gas rich ratio in which the off-gas content is relatively high in the mixing of air and off-gas. By performing catalytic combustion in the state described above, reducing gas can be easily generated.
The predetermined operation start state of the reformer is, for example, a state in which a predetermined amount of reformed gas can be discharged.
[0008]
Further, in the hydrogen generator according to the present invention, a fuel supply means (for example, a fuel supply device according to an embodiment described later) for supplying fuel that can be catalyzed by the combustion catalyst to the starting catalyst combustor. Device 40).
[0009]
According to the hydrogen generator having the above configuration, the supply of the off gas is stopped when the warm-up of the starting catalytic combustor is completed by, for example, the catalytic combustion of the off gas, and the fuel can be supplied from the fuel supply unit to the starting catalytic combustor. it can. That is, only the off-gas is supplied until the combustion catalyst of the starting catalytic combustor is in a state in which fuel composed of, for example, liquid fuel (for example, methanol or gasoline) or gaseous fuel (for example, methane or ethane) can be catalytically burned. It is possible to prevent excessive consumption of off-gas at the time of starting the hydrogen generator.
[0010]
Further, the hydrogen generator of the present invention according to claim 3 is a bypass flow path that connects the reformed gas supply unit and the off-gas tank to bypass the adsorption tower (for example, in an embodiment described later). A bypass flow passage 41) and a bypass control valve (for example, an adsorption tower bypass valve 42 in an embodiment described later) that controls a flow state of the reformed gas in the bypass flow passage.
[0011]
According to the hydrogen generator having the above configuration, when the hydrogen generator is stopped, a desired amount of off-gas required to warm up the reformer at the next start-up is required in the off-gas tank. The reformed gas can be supplied to the off-gas tank via the passage and the bypass control valve.
That is, regardless of the operation state of the pressure swing adsorption device, it is possible to secure a desired amount of off-gas including reformed gas required to warm up the reformer, and to reduce the time required to stop the hydrogen generator. And energy can be reduced.
[0012]
In addition, a method for operating a hydrogen generator according to the present invention according to claim 4 includes a reforming apparatus that reforms a raw fuel containing hydrogen into a hydrogen-rich reformed gas by a reforming reaction; An adsorption tower that adsorbs impurities other than hydrogen to separate and purify purified hydrogen gas, and a reformed gas supply unit that pressurizes the reformed gas generated by the reformer and supplies the reformed gas to the adsorption tower (for example, A PSA compressor 31) according to an embodiment of the present invention, and a pressure swing adsorption device including an off-gas tank for storing an off-gas obtained by desorbing the impurities adsorbed in the adsorption tower into the purified hydrogen gas. An operation method of the generator, wherein the hydrogen generator includes a starting catalyst combustor including a combustion catalyst capable of burning the off-gas supplied from the off-gas tank (for example, an embodiment described below). And supplying the off-gas stored in the off-gas tank to the starting catalytic combustor when the hydrogen generator is started (for example, a step in an embodiment described later). S02), the reformer is warmed up by combustion heat generated by the combustion of the off-gas in the starting catalytic combustor (for example, step S02 in an embodiment described later also serves), and the reformer When the operation start state is reached, supply of the off-gas to the starting catalytic combustor is stopped (for example, step S04 in an embodiment described later).
[0013]
According to the operation method of the hydrogen generator described above, at the time of starting the hydrogen generator, it is possible to warm up the reformer without requiring special processing only for warming up the starting catalytic combustor, for example. Thus, the time and energy required to start the hydrogen generator can be reduced, and the hydrogen generator can be operated efficiently. The predetermined operation start state of the reformer is, for example, a state in which a predetermined amount of reformed gas can be discharged.
[0014]
In addition, according to a fifth aspect of the present invention, there is provided a method for operating a hydrogen generator according to the present invention, comprising: Tower for separating and purifying purified hydrogen gas by adsorbing impurities other than hydrogen in the reformed gas, and reformed gas supply means for pressurizing the reformed gas generated in the reformer and supplying the reformed gas to the adsorption tower A pressure swing adsorption apparatus comprising (for example, a PSA compressor 31 in an embodiment described later) and an off-gas tank for storing an off-gas obtained by desorbing the impurities adsorbed in the adsorption tower into the purified hydrogen gas. A method for operating a hydrogen generator comprising: a starting catalyst combustor (for example, described later) including a combustion catalyst capable of burning the off-gas supplied from the off-gas tank. And a fuel supply unit (for example, a fuel supply device 40 according to an embodiment described later) that supplies fuel that can be catalyzed by the combustion catalyst to the start catalyst combustor. And supplying the off-gas stored in the off-gas tank to the starting catalytic combustion (for example, step S02 in an embodiment described later) at the time of starting the hydrogen generating device. The reformer is warmed up by the combustion heat generated by the combustion of the off-gas in step (for example, step S02 in an embodiment described later also serves), and the combustion catalyst of the starting catalyst combustor is brought into a predetermined active state. If it has reached, the supply of the off-gas to the starting catalytic combustor is stopped (for example, step S33 in an embodiment described later), and the fuel is supplied by the fuel supply unit. The fuel is supplied to the starting catalytic combustor (for example, step S32 in an embodiment described later), and when the reformer reaches a predetermined operation start state, the supply of the fuel to the starting catalytic combustor is stopped. (For example, step S37 in the embodiment described later).
[0015]
According to the operating method of the hydrogen generator, the combustion catalyst of the starting catalytic combustor is in a predetermined active state, for example, a fuel composed of a liquid fuel (for example, methanol or gasoline) or a gaseous fuel (for example, methane or ethane). It is only necessary to supply the off-gas until the catalyst can be catalyzed, so that it is possible to prevent the off-gas from being excessively consumed when the hydrogen generator is started.
[0016]
Further, in the method for operating a hydrogen generator according to the present invention as set forth in claim 6, when the hydrogen generator is stopped, the pressure of the off-gas in the off-gas tank, which changes according to the operation state of the pressure swing adsorption device, is increased. A predetermined pressure (for example, a restart lower limit pressure PL in an embodiment described later) corresponding to the amount of the off-gas required to warm up the reformer at the next start of the hydrogen generator. In this case, the operation of the reformer and the pressure swing adsorption device is stopped (for example, step S22 in an embodiment described later).
[0017]
According to the operation method of the hydrogen generator, the hydrogen generator can be reliably started in an appropriate state at the next start. In addition, a desired off-gas pressure can be secured at a predetermined timing according to the operation state of the pressure swing adsorption device. For example, the pressure swing adsorption device can be operated efficiently without having to increase the capacity of the off gas tank. Can be.
[0018]
Further, in the operation method of the hydrogen generator according to the present invention, the hydrogen generator bypasses the adsorption tower and connects the reformed gas supply unit to the off-gas tank. For example, a bypass passage 41 in an embodiment described later) and a bypass control valve for controlling a flow state of the reformed gas in the bypass passage (for example, an adsorption tower bypass valve 42 in an embodiment described later). When the hydrogen generator is stopped, the operation of the pressure swing adsorption device is stopped (for example, step S41 in an embodiment described later), the bypass control valve is set to an open state, and High-quality gas is supplied from the reformed gas supply unit to the off-gas tank bypassing the adsorption tower (for example, step S42 in an embodiment described later), and The pressure of the off-gas containing the reformed gas is a predetermined pressure (for example, as described later) corresponding to the amount of the off-gas containing the reformed gas required to warm up the reformer at the next start of the hydrogen generator. In this case, the bypass control valve is set to a closed state (for example, step S44 in an embodiment described later), and the operation of the reforming apparatus is started. Is stopped (for example, step S45 in an embodiment described later).
[0019]
According to the method of operating the hydrogen generator, the desired amount of off-gas including reformed gas required to warm up the reformer at the next start is ensured regardless of the operation state of the pressure swing adsorption device. And the time and energy required to stop the hydrogen generator can be reduced.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a hydrogen generator and an operation method of the hydrogen generator according to an embodiment of the present invention will be described with reference to the accompanying drawings.
The hydrogen generator 10 according to the present embodiment converts a liquid fuel (for example, methanol or gasoline) or a gaseous fuel (for example, methane or ethane) containing hydrocarbon supplied from a fuel supply unit (not shown) to hydrogen. Is reformed into a hydrogen-rich gas with an increased content of, for example, to generate a fuel gas to be supplied to a fuel electrode of a fuel cell (not shown). For example, as shown in FIG. Reformer 11 that generates a hydrogen-rich reformed gas from a raw fuel (hereinafter, simply referred to as fuel) composed of gaseous or gaseous fuel, and an impurity such as carbon monoxide or nitrogen from the hydrogen-rich reformed gas. A PSA (Pressure Swing Absorption: Pressure Swing Adsorption) device 12 for removing and purifying hydrogen gas is provided.
In the fuel cell according to the present embodiment, for example, a solid polymer electrolyte membrane composed of a cation exchange membrane or the like is combined with a fuel electrode (anode) composed of an anode catalyst and a gas diffusion layer and an oxygen electrode composed of a cathode catalyst and a gas diffusion layer. A large number of fuel cell units, each of which has an electrolyte electrode structure sandwiched between electrodes (cathodes) and is further sandwiched between a pair of separators, are stacked. The hydrogen ionized by the catalytic reaction on the anode catalyst of the anode of the fuel cell moves to the cathode through the moderately humidified solid polymer electrolyte membrane, and electrons generated by this movement are generated in an external circuit. (Not shown) and used as DC electric energy. In addition, air containing oxygen is supplied to the cathode, where hydrogen ions, electrons, and oxygen react to generate water.
[0021]
The reformer 11 includes, for example, an evaporator 21, a reformer 22, a shift converter 23, a catalytic combustor 24, a starting catalytic combustor 25, an air blower 26, and a switching flow control valve 27. It is configured.
[0022]
For example, the evaporator 21 heats and vaporizes water supplied from the outside to generate reformed steam, and converts the reformed steam from liquid fuel or gaseous fuel supplied from a fuel supply unit (not shown). The reforming fuel (hereinafter, simply referred to as reformed fuel) and the reforming air (hereinafter, simply referred to as reformed air) are supplied to the reformer 22.
The liquid fuel supplied from the fuel supply unit (not shown) is supplied to the reformer 22 in a state of being vaporized by being mixed with, for example, steam generated in the evaporator 21.
[0023]
The reformer 22 includes, for example, a Rh-based or Ru-based reforming catalyst therein, and the reformed fuel is partially oxidized by reforming air in the reformer 22 by the catalytic action of the reforming catalyst. In addition to oxidizing, the reformed fuel undergoes steam reforming by a reforming reaction using reformed steam to generate a hydrogen-rich reformed gas. Here, the oxidation reaction by the reforming air replenishes the heat required for the reforming reaction, which is an endothermic reaction.
Further, in the reformer 22, carbon monoxide is generated by a decomposition reaction of the reformed fuel which is inevitably generated, and is included in the reformed gas.
Since the reformed gas discharged from the reformer 22 has a relatively high temperature, the reformed gas is cooled to a predetermined temperature by a heat exchanger (not shown) or the like and then supplied to the shift converter 23.
[0024]
The shift converter 23 includes, for example, a shift catalyst such as a CuZn-based catalyst or a Pt-based shift catalyst, and a monoxide contained in the reformed gas discharged from the reformer 22 in the shift converter 23 by the catalytic action of the shift catalyst. The carbon is converted to carbon dioxide by a conversion reaction.
The reformed gas having the reduced carbon monoxide content in the shift converter 23 is supplied to the PSA device 12 or the catalytic combustor through the switching flow control valve 27 in accordance with the operation state of the hydrogen generator 10 as described later. 24 and the like.
[0025]
The catalytic combustor 24 includes, for example, a combustion catalyst therein, and, as described later, an off-gas containing a combustible gas such as hydrogen supplied from the PSA device 12 and a transformer 23 according to the operation state of the hydrogen generator 10. A hydrogen-rich reformed gas supplied from the fuel cell or an exhaust fuel containing, for example, unreacted hydrogen discharged from the fuel electrode of the fuel cell is burned by the air supplied from the air blower 26, and the combustion generated by this combustion is performed. Heat is supplied to the evaporator 21 via the combustion gas.
That is, the evaporator 21 generates the reformed steam by the combustion heat supplied from the catalytic combustor 24, and the used combustion gas is exhausted to the atmosphere.
[0026]
The starting catalyst combustor 25 includes, for example, a combustion catalyst therein, and supplies an off-gas containing a combustible gas such as hydrogen supplied from the PSA device 12 to the air blower 26 at the time of starting the hydrogen generator 10 as described later. The combustion heat generated by the combustion is supplied to the reformer 22 via the combustion gas, and the reformer 22 is warmed up.
[0027]
The PSA device 12 is, for example, a three-column pressure swing adsorption device, and includes a PSA compressor 31 for pressurizing reformed gas, first to third switching control valves 32a, 32b, 32c, and first to third adsorption devices. The towers 33a, 33b, 33c, the first to third equalizing pressure control valves 34a, 34b, 34c, the hydrogen storage unit 35, the off gas tank 36, the off gas flow control valve 37, the starting off gas supply valve 38, An off-gas supply valve 39 is provided.
The off-gas tank 36 is provided with a pressure sensor 36a that detects the pressure of the off-gas in the off-gas tank 36.
[0028]
The PSA compressor 31 is connected to each of the adsorption towers 33a, 33b, and 33c via each of the switching control valves 32a, 32b, and 32c, which are, for example, three-way switching valves. Pressurized, it can be supplied to each of the adsorption towers 33a, 33b, 33c filled with an adsorbent such as activated carbon or zeolite.
That is, in the adsorption process described later, each of the adsorption towers 33a, 33b, and 33c adsorbs and removes impurities such as carbon monoxide and nitrogen contained in the hydrogen-rich reformed gas, and is not adsorbed by the adsorbent. The reformed gas that has passed through each of the adsorption towers 33a, 33b, and 33c is converted into a purified hydrogen gas having an increased content of hydrogen gas and flows to a hydrogen storage unit 35 connected to each of the adsorption towers 33a, 33b, and 33c. It is supposed to.
As will be described later, in this adsorption process, one of the first to third switching control valves 32a, 32b, and 32c is operated in the flow direction FIN from the PSA compressor 31 to each of the adsorption towers 33a, 33b, and 33c. Is set.
[0029]
Further, each of the adsorption towers 33a, 33b, 33c is connected to the off-gas tank 36 via each of the switching control valves 32a, 32b, 32c, and is discharged from any of the first to third adsorption towers 33a, 33b, 33c. The purified hydrogen gas that has flowed through each of the adsorption towers 33a, 33b, 33c is allowed to flow to the off-gas tank 36 as off-gas.
That is, in the cleaning process described below, when purified hydrogen gas discharged from any of the first to third adsorption towers 33a, 33b, 33c flows through each of the adsorption towers 33a, 33b, 33c, each of the adsorption towers 33a, 33b. , 33c are adsorbed by the adsorbent in the adsorbent, are desorbed and discharged together with the purified hydrogen gas to the off-gas tank 36, and the inside of each of the adsorption towers 33a, 33b, 33c is washed, so to speak. It becomes.
As will be described later, in this cleaning process, one of the first to third switching control valves 32a, 32b, 32c is connected to the flow direction FOUT from each of the adsorption towers 33a, 33b, 33c to the PSA off-gas tank 36. Is set to
[0030]
Further, each of the adsorption towers 33a, 33b, 33c is connected to the pressure equalizing control flow path 34 via each pressure equalizing control valve 34a, 34b, 34c, for example, which is a three-way switching valve. A flow direction OUT from each of the adsorption towers 33a, 33b, 33c to the equalization control flow path 34, or a flow from the equalization control flow path 34 to each of the adsorption towers 33a, 33b, 33c. Switching to the direction IN is enabled.
That is, in the equalizing-in process and the equalizing-out process described later, one of the first to third equalizing control valves 34a, 34b, and 34c is set to a closed state, and the other two are set. One is set in the flow direction OUT toward the equalization control flow path 34 and the other is set in the flow direction IN toward each of the adsorption towers 33a, 33b, 33c, so that the first to third adsorption towers 33a, 33b are set. , 33c have the same internal pressure.
[0031]
That is, the switching of the flow direction in each of the switching control valves 32a, 32b, 32c and each of the equalizing control valves 34a, 34b, 34c is controlled, so that, for example, as shown in FIG. A series of processes including pressure release, pressure reduction, washing, equalization-in, and pressure increase are repeatedly executed.
[0032]
For example, from time t0 to time t1 shown in FIG. 2, the first switching control valve 32a is set in the flow direction FIN, and the first pressure equalizing control valve 34a is set in the closed state, so that the inside of the first adsorption tower 33a is set. Is supplied, and the purified hydrogen gas purified and separated in the first adsorption tower 33a is discharged toward the hydrogen storage unit 35 (first adsorption tower 33a: adsorption).
At this time, the second pressure equalizing control valve 34b is set in the flow direction IN and the third pressure equalizing control valve 34c is set in the flow direction OUT, so that the gas flows from the third adsorption tower 33c to the second adsorption tower 33b. The second adsorption tower 33b is washed with the purified hydrogen gas, the third adsorption tower 33c is depressurized, and the second switching control valve 32b is set in the flow direction FOUT. The off-gas flows to 36, and the pressure of the off-gas tank 36 changes in a rising tendency.
[0033]
Next, from time t1 to t2 shown in FIG. 2, the second switching control valve 32b is set to the closed state, and the supply of the off gas toward the off gas tank 36 is stopped, so that the pressure of the off gas tank 36 tends to decrease. Changes to
Further, the purified hydrogen gas flowing from the third adsorption tower 33c to the second adsorption tower 33b causes the pressures of the second adsorption tower 33b and the third adsorption tower 33c to have the same value (the second adsorption tower 33b: Input, third adsorption tower 33c: pressure equalization-output).
[0034]
Next, from time t2 to time t3 shown in FIG. 2, the first equalization control valve 34a is set in the flow direction OUT, and the third equalization control valve 34c is set in the closed state, whereby the first adsorption tower is set. The pressure of the second adsorption tower 33b is increased by the purified hydrogen gas flowing from the third adsorption tower 33b to the second adsorption tower 33b.
At this time, when the third switching control valve 32c is set in the flow direction FOUT, the off-gas flows from the third adsorption tower 33c to the off-gas tank 36, and the pressure in the third adsorption tower 33c is reduced. The pressure at 36 changes in an upward trend.
[0035]
Next, from time t3 to time t4 shown in FIG. 2, the first switching control valve 32a is set to the closed state, the second switching control valve 32b is set to the flow direction FIN, and the second equalizing control valve 34b is closed. By setting to the state, the pressurized reformed gas is supplied into the second adsorption tower 33a, and the purified hydrogen gas purified in the second adsorption tower 33b is discharged toward the hydrogen storage unit 35. (Second adsorption tower 33b: adsorption).
At this time, the third equalizing control valve 34c is set in the flow direction IN, and the third switching control valve 32c is set in the flow direction FOUT, so that the purified hydrogen gas flows from the first adsorption tower 33a to the third adsorption tower 33c. Flows, the pressure of the first adsorption tower 33a is reduced, the third adsorption tower 33c is washed, off-gas flows from the third adsorption tower 33c to the off-gas tank 36, and the pressure of the off-gas tank 36 tends to increase. Change.
[0036]
Next, from time t4 to time t5 shown in FIG. 2, the third switching control valve 32c is set to the closed state, and the purified hydrogen gas flowing from the first adsorption tower 33a to the third adsorption tower 33c causes the first adsorption tower 33a to be closed. And the third adsorption tower 33c have the same pressure (the first adsorption tower 33a: equalization-out, the third adsorption tower 33c: equalization-in).
At this time, the supply of the off-gas toward the off-gas tank 36 is stopped, so that the pressure of the off-gas tank 36 changes in a decreasing tendency.
[0037]
Next, from time t5 to time t6 shown in FIG. 2, the first equalization control valve 34a is set to the closed state, and the second equalization control valve 34b is set to the flow direction OUT, whereby the second adsorption tower is set. The pressure of the third adsorption tower 33c is increased by the purified hydrogen gas flowing from the third adsorption tower 33c to the third adsorption tower 33c.
At this time, when the first switching control valve 32a is set in the flow direction FOUT, the off-gas flows from the first adsorption tower 33a to the off-gas tank 36, and the first adsorption tower 33a is depressurized. The pressure at 36 changes in an upward trend.
[0038]
Next, from time t6 to t7 shown in FIG. 2, the second switching control valve 32b is set to the closed state, the third switching control valve 32c is set to the flow direction FIN, and the third equalizing control valve 34c is closed. By setting to the state, the pressurized reformed gas is supplied into the third adsorption tower 33c, and the purified hydrogen gas purified in the third adsorption tower 33c is discharged toward the hydrogen storage unit 35. (Third adsorption tower 33c: adsorption).
At this time, the first equalization control valve 34a is set in the flow direction IN, and the first switching control valve 32a is set in the flow direction FOUT, so that the purified hydrogen gas flows from the second adsorption tower 33b to the first adsorption tower 33a. Flows, the pressure of the second adsorption tower 33b is reduced, the first adsorption tower 33a is washed, off-gas flows from the first adsorption tower 33a to the off-gas tank 36, and the pressure of the off-gas tank 36 tends to increase. Change.
[0039]
Next, from time t7 to time t8 shown in FIG. 2, the first switching control valve 32a is set to the closed state, and the purified hydrogen gas flowing from the second adsorption tower 33b to the first adsorption tower 33a causes the first adsorption tower 33a to be closed. And the pressure of the second adsorption tower 33b are equivalent (the first adsorption tower 33a: pressure equalization-in, the second adsorption tower 33b: pressure equalization-out).
At this time, the supply of the off-gas toward the off-gas tank 36 is stopped, so that the pressure of the off-gas tank 36 changes in a decreasing tendency.
[0040]
Next, from time t8 to t9 shown in FIG. 2, the second equalization control valve 34b is set to the closed state, and the third equalization control valve 34c is set to the flow direction OUT, so that the third adsorption tower is set. The pressure of the first adsorption tower 33a is increased by the purified hydrogen gas flowing from the first adsorption tower 33a to the first adsorption tower 33a.
At this time, when the second switching control valve 32b is set in the flow direction FOUT, the off-gas flows from the second adsorption tower 33b to the off-gas tank 36, and the pressure in the second adsorption tower 33b is reduced. The pressure at 36 changes in an upward trend.
Then, in the following, a series of processes from time t0 to time t9 described above is repeatedly executed.
[0041]
The off-gas discharged from the off-gas tank 36 toward the reforming apparatus 11 is adjusted in flow rate appropriately by an off-gas flow rate adjusting valve 37, and then, for example, according to the operation state of the hydrogen generator 10 or the like, the starting off-gas supply valve 38 And supplied to the catalytic combustor 24 via the off-gas supply valve 39.
[0042]
The hydrogen generator 10 according to the present embodiment has the above-described configuration. Next, a method of operating the hydrogen generator 10 will be described with reference to the accompanying drawings.
[0043]
Hereinafter, the process of the start control of the hydrogen generator 10 will be described.
First, for example, in step S01 shown in FIG. 3, air is supplied from the air blower 26 to the catalytic combustor 24 and the starting catalytic combustor 25. Thereby, the flow rate of the air supplied to the catalytic combustor 24 and the starting catalytic combustor 25 is set to a predetermined value, for example, at time S01 shown in FIGS. 4B and 4E.
Next, in step S02, the starting off-gas supply valve 38 and the off-gas supply valve 39 are set to the open state, and the off-gas, that is, purified hydrogen gas and monoxide are supplied from the off-gas tank 36 to the catalyst combustor 24 and the starting catalyst combustor 25. A gas containing impurities such as carbon and nitrogen is supplied. Thereby, the flow rate of the off-gas supplied to the catalytic combustor 24 and the starting catalytic combustor 25 is set to a predetermined value by the off-gas flow control valve 37 and the like, for example, at time S02 shown in FIGS. 4 (c) and 4 (f). Is set.
As a result, combustible gases such as hydrogen and carbon monoxide contained in the off-gas are burned by the combustion catalysts of the catalytic combustor 24 and the starting catalytic combustor 25, and the combustion gas generated by these combustions is converted into the reformer 22. Then, the temperature of the reformer 22 and the temperature of the evaporator 21 are changed to increase, for example, at time a1 shown in FIG.
[0044]
Next, in step S03, it is determined whether or not the temperature of the reformer 22 has reached a predetermined reformer activation start temperature TA, that is, a temperature at which the reforming catalyst is in a predetermined active state.
If this determination is "NO", the flow returns to step S03.
On the other hand, when the determination result is “YES”, for example, when the temperature of the reformer 22 reaches the predetermined reformer activation start temperature TA as at time S03 shown in FIG. Proceed to.
At time S03 shown in FIG. 4, the temperature of the reformer 22 reaches a predetermined reformer activation start temperature TA, and the temperature of the evaporator 21 reaches a predetermined start completion temperature TS. ing.
[0045]
In step S04, the starting off-gas supply valve 38 is set to the closed state, and the supply of the off-gas to the starting catalytic combustor 25 is stopped. Thereby, the flow rate of the off-gas supplied to the starting catalytic combustor 25 is set to zero, for example, at time S04 shown in FIG.
Next, in step S05, the supply of air from the air blower 26 to the starting catalytic combustor 25 is stopped. Thereby, the flow rate of the air supplied to the starting catalytic combustor 25 is set to zero, for example, at time S05 shown in FIG.
Next, in step S06, the supply of the reforming steam from the evaporator 21 to the reformer 22 is started because the evaporator 21 has already reached the predetermined start completion state at the time S03 described above. Thereby, the flow rate of the reforming steam supplied to the reformer 22 is set to a predetermined value, for example, at time S06 shown in FIG.
[0046]
Next, in step S07, supply of the reformed fuel to the reformer 22 is started. Thereby, the flow rate of the reformed fuel supplied to the reformer 22 is set to a predetermined value, for example, at time S07 shown in FIG.
Next, in step S08, supply of the reforming air to the reformer 22 is started. Thereby, the flow rate of the reforming air supplied to the reformer 22 is set to a predetermined value, for example, at time S08 shown in FIG.
Along with this, the operation of the reformer 22 is started, and the temperature of the reformer 22 further changes, for example, at time a2 shown in FIG.
[0047]
Next, in step S09, it is determined that the reformer 22 is reaching a predetermined operating state, and the reformer 22 is discharged from the reformer 22, for example, after time S09 shown in FIG. The reformed gas is supplied to the catalytic combustor 24 via the shift converter 23 and the switching flow control valve 27. Along with this, for example, the off-gas flow control valve 37 causes the catalyst to be removed from the off-gas tank 36 in response to the increase in the flow rate of the reformed gas supplied to the catalytic combustor 24, as shown after time S09 shown in FIG. The flow rate of the off gas supplied to the combustor 24 is reduced.
Then, in step S10, when the flow rate of the reformed gas supplied from the shift converter 23 to the catalytic combustor 24 reaches a predetermined value, for example, at time S10 shown in FIG. The flow rate adjusting valve 37 sets the flow rate of the off-gas supplied from the off-gas tank 36 to the catalytic combustor 24 to zero.
[0048]
Next, in step S11, it is determined whether or not the composition of the reformed gas discharged from the reformer 22 is stable. Here, for example, it is determined whether the time variation of the detected value of the concentration of each gas such as hydrogen, carbon hydroxide, carbon monoxide, etc. contained in the reformed gas discharged from the reformer 22 has decreased to a predetermined variation or less. Or, for example, data on the time variation of the concentration of each gas such as hydrogen, carbon hydroxide, and carbon monoxide contained in the reformed gas discharged in the warm-up operation state of the reformer 22. It is stored in advance, and from this data, the time required for the time variation of the detected value of the concentration of each gas to be reduced to a predetermined variation or less is acquired, and it is determined whether or not this time has elapsed.
If this determination is "NO", the flow returns to step S11.
On the other hand, if the result of this determination is "YES", the flow proceeds to step S12, in which the supply of the reformed gas to the PSA device 12 is started, and a series of processing ends.
Here, the supply of the reformed gas to the catalytic combustor 24 is stopped by the switching control of the switching flow rate control valve 27 and supplied to the catalytic combustor 24, for example, at time a4 shown in FIG. The reformed gas is supplied to the PSA device 12. As a result, the operation of the PSA device 12 is started, and the amount of off gas stored in the off gas tank 36 of the PSA device 12 changes in a tendency to increase. For example, as shown at time S12 shown in FIG. The flow rate of the off-gas supplied from the off-gas tank 36 to the catalytic combustor 24 via the flow-rate adjusting valve 37 changes in an increasing manner.
[0049]
Hereinafter, the process of the stop control of the hydrogen generator 10 will be described.
First, for example, in step S21 shown in FIG. 5, it is determined whether or not the pressure of the off-gas tank 36 is equal to or higher than a predetermined restart lower limit pressure PL.
If this determination is "NO", the flow returns to step S21.
On the other hand, if the result of this determination is “YES”, the flow proceeds to step S22.
The predetermined restart lower limit pressure PL depends on the amount of off-gas required to start the reformer 22 or the evaporator 21 to a predetermined operation state in the start control processing in steps S01 to S12 described above. As shown in FIG. 2, for example, as shown in FIG. 2, the pressure of the off-gas tank 36 exceeds the restart lower limit pressure PL in a predetermined operation state of the PSA device 12.
[0050]
In step S22, it is determined that the reformer 22 and the evaporator 21 can be started up to a predetermined operation state in the next start control process, and the operation of the reformer 11 and the PSA device 12 is started. Is stopped, and a series of processing ends.
[0051]
As described above, according to the hydrogen generator 10 of the present embodiment, the combustible gas such as hydrogen or carbon monoxide is contained in the catalytic combustor 24 and the starting catalytic combustor 25 from the off-gas tank 36 of the PSA device 12. With the configuration in which the off-gas can be supplied, a special device such as an electric heater for warming up the catalytic combustor 24 and the starting catalytic combustor 25 is not required at the time of starting the hydrogen generator 10 or the like. In addition, the reformer 22 and the evaporator 21 can be warmed up and started up to a desired operation state, and the configuration of the apparatus can be simplified.
[0052]
Moreover, according to the operating method of hydrogen generator 10 according to the present embodiment, when starting hydrogen generator 10, special time and energy are used only for warming up catalytic combustor 24 and starting catalytic combustor 25. Can be prevented, and the time and energy efficiency required for starting the hydrogen generator 10 can be improved.
Furthermore, for example, compared to the case where hydrocarbon fuel such as methanol is burned in the catalytic combustor 24 and the starting catalytic combustor 25 from the start of the hydrogen generator 10, for example, nitrogen oxides (NO _X ) And the emission of unburned fuel and carbon monoxide.
Moreover, since the combustible range with respect to the mixing ratio with air is relatively wide as compared with, for example, a hydrocarbon fuel such as methanol, the off-gas rich ratio in which the off-gas content is relatively high in the mixing of air and off-gas. By performing catalytic combustion in the state described above, reducing gas can be easily generated.
[0053]
Further, when the hydrogen generator 10 is stopped, a pressure corresponding to the amount of off gas required to start the reformer 22 and the evaporator 21 to a predetermined operation state at the next start is ensured in the off gas tank 36. In addition, the hydrogen generator 10 can be reliably started in an appropriate state. In addition, a desired pressure can be secured at a predetermined timing according to the operation state of the PSA device 12, and the PSA device 12 can be operated efficiently without, for example, increasing the capacity of the off-gas tank 36.
[0054]
In the above-described embodiment, in the process of the start control of the hydrogen generator 10, the temperature of the reformer 22 is set to a predetermined reformer activation start temperature TA, that is, a temperature at which the reforming catalyst becomes a predetermined active state. The off-gas is supplied from the off-gas tank 36 to the starting catalytic combustor 25 until the temperature of the evaporator 21 reaches the predetermined starting completion temperature TS, and the reformer 22 The off-gas is supplied from the off-gas tank 36 to the catalytic combustor 24 over a period from when the operation state is reached and a predetermined amount of the reformed gas is discharged. However, the present invention is not limited to this. The off-gas supply to the catalytic combustor 24 and the starting catalytic combustor 25 may be stopped at a timing before the temperature of the reactor 22 reaches the predetermined reformer activation start temperature TA.
In this case, for example, as in the hydrogen generator 10 according to the first modified example of the present embodiment shown in FIG. 6, liquid fuel (for example, methanol or gasoline) is supplied to the catalytic combustor 24 and the starting catalytic combustor 25. The hydrogen generator 10 is provided with a fuel supply device 40 capable of supplying a fuel composed of a gaseous fuel (for example, methane or ethane). Then, when each of the combustion catalysts provided in the catalytic combustor 24 and the starting catalytic combustor 25 reaches a state in which fuel composed of liquid fuel or gaseous fuel can be catalytically combusted, the catalytic combustor 24 and the starting catalytic combustor 25 are activated. The supply of off-gas to the fuel cell is stopped and the fuel is switched to supply fuel composed of liquid fuel or gaseous fuel.
[0055]
That is, in the processing of the start control of the hydrogen generator 10 according to the first modification of the present embodiment shown in FIG. 7, the difference from the processing of the start control in steps S01 to S12 in the above-described embodiment is, for example, The processing of steps S31 to S36 is added between steps S02 and S03, the processing of step S37 is executed instead of step S04, and the processing of step S38 is executed instead of step S10. is there.
The description of the same parts as those of the above-described embodiment will be simplified or omitted below.
[0056]
That is, in the first modified example, for example, in step S31 shown in FIG. 7, the temperature of the reformer 22 related to the temperature of the combustion catalyst of the starting catalyst combustor 25 is changed so that the combustion catalyst in the starting catalyst combustor 25 is It is determined whether or not a predetermined catalyst activation temperature TC (catalyst activation temperature TC <reformer activation start temperature TA) has been reached at which a fuel composed of fuel and gaseous fuel can be catalytically burned.
If this determination is "NO", the flow returns to step S31.
On the other hand, when the determination result is “YES”, for example, when the temperature of the reformer 22 has reached the predetermined catalyst activation temperature TC as at time S31 shown in FIG. 8A, the process proceeds to step S32.
[0057]
In step S32, it is determined that the combustion catalyst is capable of catalytic combustion in the starting catalyst combustor 25, and the fuel is supplied to the starting catalyst combustor 25, for example, after time S32 shown in FIG. To start. Accordingly, the flow rate of the fuel supplied to the starting catalytic combustor 25 changes in an increasing tendency.
Then, in step S33, when the flow rate of the fuel supplied to the starting catalytic combustor 25 reaches a predetermined value, for example, after time S33 shown in FIG. 8 (g), for example, the starting off-gas supply valve By 38, the flow rate of the off-gas supplied from the off-gas tank 36 to the starting catalytic combustor 25 is changed to a decreasing tendency to zero.
[0058]
Next, in step S34 shown in FIG. 7, the temperature of the evaporator 21 related to the temperature of the combustion catalyst of the catalyst combustor 24 is such that the combustion catalyst in the catalyst combustor 24 is capable of catalytically combusting a fuel composed of liquid fuel or gaseous fuel. It is determined whether or not a predetermined catalyst activation temperature TC has been reached (however, the catalyst activation temperature TC <start completion temperature TS).
If this determination is "NO", the flow returns to step S34.
On the other hand, when the result of this determination is “YES”, for example, when the temperature of the evaporator 21 has reached the predetermined catalyst activation temperature TC as at time S34 shown in FIG.
[0059]
In step S35, it is determined that the combustion catalyst is capable of catalytic combustion of the fuel in the catalytic combustor 24, and the supply of the fuel to the catalytic combustor 24 is started, for example, after time S35 shown in FIG. I do. Along with this, the flow rate of the fuel supplied to the catalytic combustor 24 changes in a tendency to increase.
Then, in step S36, when the flow rate of the fuel supplied to the catalytic combustor 24 reaches a predetermined value, for example, after time S36 shown in FIG. The flow rate of off-gas supplied from the off-gas tank 36 to the catalytic combustor 24 is changed to a decreasing tendency to zero.
[0060]
In step S37, the supply of fuel to the starting catalytic combustor 25 is stopped. Thereby, the flow rate of the fuel supplied to the starting catalytic combustor 25 is set to zero, for example, at time S37 shown in FIG.
[0061]
Further, in step S09, it is determined that the reformer 22 is approaching the predetermined operating state, and the reformer 22 discharged from the reformer 22, for example, after time S09 shown in FIG. The raw gas is supplied to the catalytic combustor 24 via the transformer 23 and the switching flow control valve 27. Accordingly, for example, after the time S09 shown in FIG. 8D, the flow rate of the fuel supplied to the catalytic combustor 24 is reduced in accordance with the increase in the flow rate of the reformed gas supplied to the catalytic combustor 24. Lower.
Then, in step S38, when the flow rate of the reformed gas supplied from the shift converter 23 to the catalytic combustor 24 reaches a predetermined value, for example, at time S38 shown in FIG. The flow rate of the fuel supplied to the vessel 24 is set to zero.
[0062]
According to the hydrogen generator 10 and the method of operating the hydrogen generator 10 according to the first modification, the combustion catalyst of the catalytic combustor 24 or the starting catalytic combustor 25 can catalytically combust a fuel composed of a liquid fuel or a gaseous fuel. The off-gas supply can be stopped in a state, that is, in a state in which the warming-up of the catalytic combustor 24 and the starting catalytic combustor 25 is completed, and the pressure of the off-gas to be secured for the next start when the hydrogen generator 10 is stopped. Can be reduced, and the PSA device 12 can be operated efficiently.
Further, in the catalytic combustor 24 and the starting catalytic combustor 25 whose warm-up is completed by the supply of the off-gas, the catalytic combustion can be appropriately performed without the need to vaporize the liquid fuel. It is only necessary to provide a device for performing the operation, and the device configuration can be simplified.
[0063]
In the above-described embodiment, the operation of the reformer 11 and the PSA device 12 are stopped when the pressure of the off-gas tank 36 exceeds the restart lower limit pressure PL in a predetermined operation state of the PSA device 12. However, the present invention is not limited to this. For example, as in a hydrogen generator 10 according to a second modification of the present embodiment shown in FIG. 9, the PSA compressor 31 bypasses the first to third adsorption towers 33a, 33b, 33c. A bypass channel 41 and an adsorption tower bypass valve 42 for connecting to the off-gas tank 36 are provided, and the pressure of the off-gas tank 36 can be set to exceed the restart lower limit pressure PL regardless of the operating state of the PSA device 12. Good.
Here, during the operation of the PSA device 12, the adsorption tower bypass valve 42 is set to a closed state.
[0064]
That is, for example, in the process of stopping control of the hydrogen generator 10 according to the second modification of the present embodiment shown in FIG. 10, first, in step S21, whether the pressure of the off-gas tank 36 is equal to or higher than a predetermined restart lower limit pressure PL. Determine whether or not.
If this determination is "YES", the flow proceeds to step S22 described above.
On the other hand, if the result of this determination is “NO”, the flow proceeds to step S41.
[0065]
In step S41, the operation of the PSA device 12 is stopped.
Next, in step S42, the adsorption tower bypass valve 42 is set to the open state. Thereby, the reformed gas supplied from the PSA compressor 31 bypasses the adsorption towers 33a, 33b, 33c and flows to the off-gas tank 36.
Next, in step S43, it is determined whether or not the pressure of the off-gas tank 36 is equal to or higher than a predetermined restart lower limit pressure PL.
If this determination is "NO", the flow returns to step S43.
On the other hand, when the result of this determination is “YES”, the flow proceeds to step S44.
[0066]
In step S44, the adsorption tower bypass valve 42 is set to a closed state.
Next, in step S45, the operation of the reforming apparatus 11 is stopped, and a series of processing ends.
[0067]
According to the hydrogen generator 10 and the method of operating the hydrogen generator 10 according to the second modified example, a desired pressure for the next start can be ensured regardless of the operating state of the PSA device 12, The time and energy required to stop the hydrogen generator 10 can be reduced.
[0068]
【The invention's effect】
As described above, according to the hydrogen generator of the present invention, it is possible to surely warm up the reformer while preventing the device configuration from becoming complicated. Also, for example, compared to the case where a hydrocarbon fuel such as methanol is burned in a starting catalytic combustor from the start of the hydrogen generator, for example, nitrogen oxides (NO _X ) And the amount of unburned fuel and carbon monoxide emitted can be reduced, and by performing catalytic combustion in an off-gas rich state, a reducing gas can be easily generated.
Furthermore, according to the hydrogen generator of the present invention described in claim 2, it is possible to prevent the off gas from being excessively consumed when the hydrogen generator is started.
Furthermore, according to the hydrogen generator of the present invention as set forth in claim 3, the desired amount of off-gas including reformed gas required for warming up the reformer, regardless of the operation state of the pressure swing adsorption device. The time and energy required to stop the hydrogen generator can be reduced.
[0069]
Further, according to the method for operating a hydrogen generator of the present invention as set forth in claim 4, when the hydrogen generator is started, for example, a special treatment only for warming up the starting catalytic combustor is not required, and the modification can be performed. The heater can be warmed up, the time and energy required to start the hydrogen generator can be reduced, and the hydrogen generator can be operated efficiently.
Further, according to the method for operating the hydrogen generator of the present invention described in claim 5, it is possible to prevent the off-gas from being excessively consumed when the hydrogen generator is started.
[0070]
Further, according to the method for operating the hydrogen generator of the present invention, it is possible to reliably start the hydrogen generator in an appropriate state at the next start.
Further, according to the operation method of the hydrogen generator of the present invention, the reforming required for warming up the reformer at the next start-up regardless of the operation state of the pressure swing adsorption device. A desired amount of off-gas including gas can be secured, and the time and energy required for stopping the hydrogen generator can be reduced.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a hydrogen generator according to an embodiment of the present invention.
FIG. 2 is a graph showing an example of a pressure change of an off-gas tank according to an operation state of the PSA device shown in FIG.
FIG. 3 is a flowchart showing an operation method of the hydrogen generator shown in FIG. 1, in particular, a process of start control.
FIG. 4 (a) is a graph showing an example of a time change of the temperature of the reformer and the evaporator, and FIG. 4 (b) is an example of a time change of the air flow rate in the catalytic combustor. FIG. 4C is a graph showing an example of a temporal change in the flow rate of the off gas in the catalytic combustor, and FIG. 4D is a graph showing the temporal change in the flow rate of the reformed gas in the catalytic combustor. FIG. 4 (e) is a graph showing one example, and FIG. 4 (e) is a graph showing an example of a time change of the flow rate of air in the starting catalytic combustor; FIG. 4G is a graph showing an example of the change, FIG. 4G is a graph showing an example of a change over time of the flow rate of the reforming steam in the reformer, and FIG. FIG. 4 (i) is a graph showing an example of the change over time of the flow rate of Is a graph showing an example of a temporal change in the flow rate of reforming air in.
FIG. 5 is a flowchart showing a method of operating the hydrogen generator shown in FIG. 1, particularly a process of stop control.
FIG. 6 is a configuration diagram of a hydrogen generator according to a first modification of the present embodiment.
FIG. 7 is a flowchart showing an operation method of the hydrogen generator according to the first modification of the present embodiment shown in FIG. 6, in particular, a start control process.
FIG. 8 (a) is a graph showing an example of a time change of the temperature of the reformer and the evaporator, and FIG. 8 (b) is an example of a time change of the air flow rate in the catalytic combustor. FIG. 8C is a graph showing an example of a temporal change in the flow rate of the off gas in the catalytic combustor, and FIG. 8D is a graph showing an example of a temporal change in the fuel flow in the catalytic combustor. FIG. 8E is a graph showing an example of a time change of the flow rate of the reformed gas in the catalytic combustor. FIG. 8F is a graph showing a time change of the air flow rate in the starting catalytic combustor. FIG. 8 (g) is a graph showing an example of a change over time of the flow rate of the off-gas in the starting catalytic combustor, and FIG. 8 (h) is a graph showing the fuel flow rate in the starting catalytic combustor. FIG. 8 (i) is a graph showing an example of a time change, and FIG. FIG. 8 (j) is a graph showing an example of a temporal change in the flow rate of reformed steam in the reformer, and FIG. 8 (j) is a graph showing an example of a temporal change in the flow rate of reformed fuel in the reformer. k) is a graph showing an example of a change over time in the flow rate of reformed air in the reformer.
FIG. 9 is a configuration diagram of a hydrogen generator according to a second modification of the present embodiment.
FIG. 10 is a flowchart showing a method of operating the hydrogen generator according to a second modification of the present embodiment shown in FIG. 9, particularly a process of stop control.
[Explanation of symbols]
10 Hydrogen generator
11 Reformer
12 PSA device (pressure swing adsorption device)
24 catalytic combustor
25 Starting catalytic combustor
31 PSA compressor (reformed gas supply means)
33a first adsorption tower
33b second adsorption tower
33c third adsorption tower
36 Off-gas tank
40 Fuel supply device (fuel supply means)
41 Bypass channel
42 Adsorption tower bypass valve (bypass control valve)

Claims (7)

A reformer for reforming a raw fuel containing hydrogen into a hydrogen-rich reformed gas by a reforming reaction;
A pressure swing adsorption device that separates and purifies purified hydrogen gas by a pressure swing adsorption method from the reformed gas generated by the reforming device,
The pressure swing adsorption apparatus includes an adsorption tower that adsorbs impurities other than hydrogen in the reformed gas, and a reformed gas that pressurizes the reformed gas generated by the reformer and supplies the reformed gas to the adsorption tower. Supply means, comprising an off-gas tank for storing an off-gas obtained by desorbing the impurities adsorbed in the adsorption tower in the purified hydrogen gas,
A hydrogen generator comprising: a combustion catalyst capable of burning the off-gas supplied from the off-gas tank; and a starting catalyst combustor for warming up the reformer when the hydrogen generator is started. 2. The hydrogen generator according to claim 1, further comprising a fuel supply unit configured to supply a fuel that can be catalyzed by the combustion catalyst to the starting catalyst combustor. 3. A bypass flow path connecting the reformed gas supply means and the off-gas tank bypassing the adsorption tower,
3. The hydrogen generator according to claim 1, further comprising a bypass control valve configured to control a flow state of the reformed gas in the bypass passage. 4. A reformer for reforming a raw fuel containing hydrogen into a hydrogen-rich reformed gas by a reforming reaction;
An adsorption tower for adsorbing impurities other than hydrogen in the reformed gas to separate and purify purified hydrogen gas, and a reformed gas supplied to the adsorption tower by pressurizing the reformed gas generated by the reformer and supplying the reformed gas to the adsorption tower A pressure swing adsorption device comprising: a supply means; and an off-gas tank for storing an off-gas obtained by desorbing the impurities adsorbed in the adsorption tower into the purified hydrogen gas. ,
The hydrogen generator includes a starting catalyst combustor including a combustion catalyst capable of burning the off-gas supplied from the off-gas tank,
At the time of starting the hydrogen generator, supplying the offgas stored in the offgas tank to the starting catalytic combustor,
Warming up the reformer by combustion heat generated by the combustion of the off-gas in the starting catalytic combustor,
A method for operating a hydrogen generator, wherein the supply of the off-gas to the starting catalytic combustor is stopped when the reformer reaches a predetermined operation start state. A reformer for reforming a raw fuel containing hydrogen into a hydrogen-rich reformed gas by a reforming reaction of a reforming catalyst;
An adsorption tower for adsorbing impurities other than hydrogen in the reformed gas to separate and purify purified hydrogen gas, and a reformed gas supplied to the adsorption tower by pressurizing the reformed gas generated by the reformer and supplying the reformed gas to the adsorption tower A pressure swing adsorption device comprising: a supply means; and an off-gas tank for storing an off-gas obtained by desorbing the impurities adsorbed in the adsorption tower into the purified hydrogen gas. ,
The hydrogen generator includes a starting catalyst combustor including a combustion catalyst capable of burning the off-gas supplied from the off-gas tank, and a fuel for supplying the starting catalyst combustor with a fuel that can be catalyzed by the combustion catalyst. Supply means,
At the time of starting the hydrogen generator, supplying the offgas stored in the offgas tank to the starting catalytic combustion,
Warming up the reformer by combustion heat generated by the combustion of the off-gas in the starting catalytic combustor,
When the combustion catalyst of the starting catalyst combustor has reached a predetermined active state, stop supplying the off-gas to the starting catalyst combustor,
Supplying the fuel to the starting catalytic combustor by the fuel supply means,
A method for operating a hydrogen generator, wherein the supply of the fuel to the starting catalytic combustor is stopped when the reforming device reaches a predetermined operation start state. When the hydrogen generator is stopped, the pressure of the off-gas in the off-gas tank, which changes according to the operation state of the pressure swing adsorption device, warms up the reformer at the next start of the hydrogen generator. The hydrogen according to claim 4 or 5, wherein the operation of the reformer and the pressure swing adsorption device is stopped when the pressure becomes equal to or higher than a predetermined pressure corresponding to the amount of the off-gas required for the hydrogen supply. How to operate the generator. A bypass passage connecting the reformed gas supply unit and the off-gas tank bypassing the adsorption tower; and a bypass control valve controlling a flow state of the reformed gas in the bypass passage. With
When the hydrogen generator is stopped,
Stop the operation of the pressure swing adsorption device,
Setting the bypass control valve to an open state, supplying the reformed gas to the off-gas tank from the reformed gas supply means bypassing the adsorption tower,
The pressure of the off-gas containing the reformed gas in the off-gas tank was dependent on the amount of the off-gas containing the reformed gas required to warm up the reformer at the next start of the hydrogen generator. When the pressure is equal to or higher than a predetermined pressure, the bypass control valve is set to a closed state,
The operation method of the hydrogen generator according to claim 6, wherein the operation of the reformer is stopped.

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