JP2020083740A - Hydrogen production apparatus and hydrogen production method - Google Patents

Abstract

To provide a hydrogen production apparatus and a hydrogen production method, which prevent supply of a reformed gas that does not reach a predetermined hydrogen concentration at the time of start of a reformer, and improve a thermal efficiency of entire apparatus.SOLUTION: A hydrogen gas production apparatus 10, when a reformed gas in the reformer 12 does not reach a predetermined hydrogen concentration, closes a first on-off valve 102 and opens a second on-off valve 104 to supply the reformed gas to an off-gas tank 112 and supply to a burner 26 of the reformer 12 via an off-gas reflux pipe 110 to burn in a combustion chamber 25. Thus, the reformed gas that does not reach a predetermined hydrogen concentration is supplied to a hydrogen purifier 90 to prevent the purity of produced hydrogen from decreasing, and to supply to the burner 26 of the reformer 12 as a combustion gas to improve a thermal efficiency of an entire hydrogen production apparatus.SELECTED DRAWING: Figure 1

Description

The present invention relates to a hydrogen production apparatus and a hydrogen production method, and more particularly to a hydrogen production apparatus and a hydrogen production method for reforming a hydrocarbon raw material to produce hydrogen.

2. Description of the Related Art Conventionally, as a hydrogen production device for obtaining hydrogen, one that feeds a raw material hydrocarbon to a reformed gas (steam) by a reformer and then supplies it to a PSA (Pressure Swing Adsorption) device (hydrogen purifier) Are known. Hydrogen separated from impurities by the PSA is extracted from the reformed gas.

In the reformer, the hydrogen concentration of the reformed gas obtained by steam reforming the raw material hydrocarbon may not reach the predetermined concentration. For example, when the reformer is started, the internal temperature of the reformer may not rise to a predetermined temperature, and the steam-reformed reformed gas may not reach a predetermined hydrogen concentration (high carbon monoxide concentration). .. Therefore, in the hydrogen production apparatus of Patent Document 1, the reformed gas generated in the reformer and having a hydrogen concentration not reaching a predetermined level is supplied to the flare. That is, by not supplying the reformed gas generated in the reformer and having not reached the predetermined hydrogen concentration to the hydrogen purifier, it is possible to prevent production of product hydrogen that has not reached the predetermined quality.

JP, 2009-149466, A

The hydrogen production apparatus described in Patent Document 1 is excellent from the viewpoint of preventing production of product hydrogen that has not reached a predetermined quality, but there is room for improvement in terms of the thermal efficiency of the hydrogen production apparatus.

An object of the present invention is to provide a hydrogen production apparatus and a hydrogen production method in which a reformed gas which has not reached a predetermined hydrogen concentration is prevented from being supplied to a hydrogen purifier and which improves the thermal efficiency of the entire apparatus. That is.

The hydrogen producing apparatus according to claim 1, which is connected to a reformer that reforms hydrocarbons supplied as a raw material to generate a reformed gas containing hydrogen as a main component, and is connected to the reformer. A hydrogen purifier that purifies the product hydrogen by separating the gas into product hydrogen and off gas that is an impurity, an off gas flow path that returns the off gas as fuel from the hydrogen refiner to the combustion chamber of the reformer, and the off gas An off-gas tank that is provided on the flow path and temporarily stores the off-gas, and then supplies the off-gas to the reformer, and a reformed gas flow path from the reformer to the hydrogen purifier to branch to the off-gas tank. The reformed gas branch passage reaching the upstream side of the branch position to the reformed gas branch passage in the reformed gas passage, and one of the downstream side and the reformed gas branch passage. And switching means for disconnecting the other.

In this hydrogen production device, if the internal temperature of the reformer does not reach the predetermined temperature, steam reforming is not sufficiently performed in the reformer and reformed gas that does not reach the predetermined hydrogen concentration is generated. ..

For example, when the reformer is started up, the reformer produces reformed gas that has not reached the predetermined hydrogen concentration until the internal temperature reaches the predetermined temperature. At this time, in the hydrogen production device, the upstream side and the downstream side of the reformed gas flow path can be blocked by the switching means, and the upstream side and the reformed gas branch flow path can be communicated with each other. As a result, the reformed gas generated in the reformer is supplied to the off-gas tank, is supplied from the off-gas tank to the combustion chamber of the reformer as fuel, and is used for heating the reformer.

That is, the reformed gas generated in the reformer that does not reach the predetermined hydrogen concentration is prevented from reaching the hydrogen purifier, and the reformed gas that does not reach the predetermined hydrogen concentration is supplied to the flare. In comparison, the thermal efficiency of the entire device is improved.

On the other hand, for example, after a lapse of a predetermined time from the start-up time of the reformer, the internal temperature of the reformer rises and reaches a predetermined temperature, and the reformer produces a reformed gas having a predetermined hydrogen concentration. .. At this time, in the hydrogen production device, the upstream side and the downstream side of the reformed gas passage can be communicated by the switching means, and the upstream side and the reformed gas branch passage can be blocked. As a result, the reformed gas reaches the hydrogen purifier from the reformer to produce product hydrogen of a predetermined quality, and the off gas returns from the hydrogen purifier to the combustion chamber of the reformer as fuel through the offgas tank. And is used for heating the reformer. Also in this case, the thermal efficiency of the entire hydrogen production apparatus is improved as compared with the hydrogen production apparatus that does not supply the offgas as fuel to the reformer.

Furthermore, at the time of this switching, the reformed gas stored in the off-gas tank until the reformed gas reaches the hydrogen purifier and the off-gas separated from the reformed gas in the hydrogen purifier reaches the off-gas tank. It can be fed to the combustion chamber of the reformer. Therefore, the fuel supply to the combustion chamber of the reformer at the time of switching can be stably maintained and the reformer can be heated.

Thereby, the thermal efficiency of the entire hydrogen production apparatus is further improved as compared with the hydrogen production apparatus that supplies the reformed gas that does not reach the predetermined hydrogen concentration to the flare.

A hydrogen producing apparatus according to claim 2 is the hydrogen producing apparatus according to claim 1, wherein temperature detecting means for detecting a temperature of the reformed gas in the reformer, and the reforming detected by the temperature detecting means. A control unit that controls the switching unit based on the temperature of the gas.

In this hydrogen production device, the control unit determines whether the reformed gas generated based on the temperature of the reformed gas detected by the temperature detection unit has a predetermined quality, and switches the switching unit.

The control unit determines whether or not the hydrogen concentration of the reformed gas has reached a predetermined concentration based on the temperature of the reformed gas detected by the temperature detection means. For example, when the temperature of the reformed gas is lower than the predetermined temperature, the control unit determines that the reformed gas has not reached the predetermined hydrogen concentration, and the switching unit determines the upstream side and the downstream side of the reformed gas flow path. Is cut off, and the upstream side and the reformed gas branch flow path are connected. As a result, the reformed gas that has not reached the predetermined hydrogen concentration is supplied as fuel from the reformer to the combustion chamber of the reformer through the offgas tank. That is, the reformed gas that has not reached the predetermined hydrogen concentration is used for heating the reformer.

On the other hand, when the temperature of the reformed gas in the reformer is equal to or higher than the predetermined temperature, the control unit determines that the reformed gas has reached the predetermined hydrogen concentration, and the switching unit upstream side of the reformed gas flow path. And the downstream side are communicated with each other, and the upstream side and the reformed gas branch flow path are blocked. As a result, the reformed gas that has reached the predetermined hydrogen concentration is supplied to the hydrogen purifier to produce product hydrogen.

In this way, the control unit determines whether or not the reformed gas has reached a predetermined hydrogen concentration based on the reformed gas temperature of the reformer, and controls the switching means based on this, so that the product The thermal efficiency of the entire apparatus can be improved while maintaining the quality of hydrogen.

The hydrogen producing apparatus according to claim 3 is the hydrogen producing apparatus according to claim 2, wherein the off gas flow path is provided downstream of the off gas tank in the off gas flow passage, and a gas flow rate detecting unit for detecting a gas flow rate is provided. An air supply flow path for supplying air to the combustion chamber of the reactor, and an air flow rate adjusting valve provided on the air supply flow path for adjusting the flow rate of air supplied to the combustion chamber, and the control unit includes: Based on the gas flow rate detected by the gas flow rate detecting means, the air flow rate adjusting valve is controlled to adjust the air flow rate.

In this hydrogen production device, the switching means is switched based on the temperature of the reformed gas, so that the reformed gas that has not reached the predetermined hydrogen concentration is supplied as fuel to the reformer via the off-gas tank. At this time, the flow rate of the reformed gas is detected by the gas flow rate detection means provided in the off-gas flow path, and the control unit adjusts the flow rate of the air supplied to the combustion chamber of the reformer based on the reformed gas flow rate. By doing so, the combustibility of the combustion chamber is maintained well.

The hydrogen production apparatus according to claim 4 is the hydrogen production apparatus according to claim 2, wherein the reforming is provided in the off-gas passage downstream of the off-gas tank, and detects gas flow rate, and the reformer. An air supply flow path for supplying air to the combustion chamber of the reactor, and an air flow rate adjusting valve provided on the air supply flow path for adjusting the flow rate of the air supplied to the combustion chamber, and the control unit, Based on the temperature of the reformed gas and the gas flow rate detected by the gas flow rate detecting means, the air flow rate is adjusted by controlling the air flow rate adjusting valve.

In this hydrogen production device, the switching means is switched based on the temperature of the reformed gas, so that the reformed gas that has not reached the predetermined hydrogen concentration is supplied as fuel to the reformer via the off-gas tank. At this time, the flow rate of the reformed gas is detected by the gas flow rate detection means provided in the off-gas flow path, and the control section adjusts the flow rate of the air flowing into the combustion chamber of the reformer based on the flow rate and the temperature of the reformed gas. By doing so, the combustibility of the combustion chamber is maintained well.

In particular, the control unit refers to not only the flow rate of the reformed gas but also the temperature of the reformed gas to adjust the flow rate of the air supplied to the combustion chamber in accordance with the composition of the reformed gas that varies depending on the temperature. The combustibility of the chamber is further improved.
The hydrogen production method according to claim 5 is the hydrogen production apparatus according to claim 1, wherein when the hydrogen concentration of the reformed gas produced in the reformer has not reached a predetermined hydrogen concentration, By the switching means, the upstream side and the downstream side of the branch position to the reformed gas branch channel in the reformed gas channel are blocked, and the upstream side and the reformed gas branch channel are communicated with each other, When the hydrogen concentration of the reformed gas generated in the reformer reaches a predetermined hydrogen concentration, the switching unit causes the reformed gas passage to branch to the reformed gas branch passage from the branch position. Also connects the upstream side and the downstream side, and blocks the upstream side and the reformed gas branch flow path.
In this hydrogen production method, when the hydrogen concentration of the reformed gas generated in the reformer does not reach the predetermined hydrogen concentration, the switching means shuts off the upstream side and the downstream side of the reformed gas passage. , The upstream side and the reformed gas branch passage are communicated with each other. As a result, the reformed gas generated in the reformer is supplied to the off-gas tank, is supplied from the off-gas tank to the combustion chamber of the reformer as fuel, and is used for heating the reformer.

That is, the reformed gas generated in the reformer that does not reach the predetermined hydrogen concentration is prevented from reaching the hydrogen purifier, and the reformed gas that does not reach the predetermined hydrogen concentration is supplied to the flare. In comparison, the thermal efficiency of the entire device is improved.

On the other hand, when the reformed gas generated in the reformer reaches a predetermined hydrogen concentration, the switching means connects the upstream side and the downstream side of the reformed gas passage, and the upstream side and the reformed gas branch passage. Shut off. As a result, the reformed gas reaches the hydrogen purifier from the reformer to produce product hydrogen of a predetermined quality, and the off gas returns from the hydrogen purifier to the combustion chamber of the reformer as fuel through the offgas tank. And is used for heating the reformer. Also in this case, the thermal efficiency of the entire hydrogen production apparatus is improved as compared with the hydrogen production apparatus that does not supply the offgas as fuel to the reformer.

Furthermore, at the time of this switching, the reformed gas stored in the off-gas tank until the reformed gas reaches the hydrogen purifier and the off-gas separated from the reformed gas in the hydrogen purifier reaches the off-gas tank. It can be fed to the combustion chamber of the reformer. Therefore, the fuel supply to the combustion chamber of the reformer at the time of switching can be stably maintained and the reformer can be heated.

Thereby, the thermal efficiency of the entire hydrogen production apparatus is further improved as compared with the hydrogen production apparatus that supplies the reformed gas that does not reach the predetermined hydrogen concentration to the flare.
A hydrogen producing method according to claim 6 is the hydrogen producing apparatus according to claim 1, wherein when the temperature of the reformed gas generated in the reformer is less than a threshold value, the reforming is performed by the switching means. Generated by the reformer by blocking the upstream side and the downstream side of the branch position to the reformed gas branch channel in the gas channel, connecting the upstream side and the reformed gas branch channel. When the temperature of the reformed gas is equal to or higher than a threshold value, the switching means connects the upstream side and the downstream side of a branch position to the reformed gas branch channel in the reformed gas channel, The upstream side and the reformed gas branch flow path are blocked.
In this hydrogen production method, when the temperature of the reformed gas generated in the reformer is less than the threshold value, it is determined that the reformed gas has not reached a predetermined hydrogen concentration, and the switching means changes the reformed gas flow path. The upstream side and the downstream side are blocked, and the upstream side and the reformed gas branch passage are communicated. As a result, the reformed gas that has not reached the predetermined hydrogen concentration is supplied as fuel from the reformer to the combustion chamber of the reformer through the offgas tank. That is, the reformed gas that has not reached the predetermined hydrogen concentration is used for heating the reformer.

On the other hand, when the temperature of the reformed gas generated in the reformer is equal to or higher than the threshold value, it is determined that the reformed gas has reached a predetermined hydrogen concentration, and the switching means causes the reformed gas passage to have an upstream side and a downstream side. The upstream side and the reformed gas branch flow path are cut off from each other. As a result, the reformed gas that has reached the predetermined hydrogen concentration is supplied to the hydrogen purifier to produce product hydrogen.

Thus, in this hydrogen production method, it is determined whether the reformed gas has reached a predetermined hydrogen concentration based on the reformed gas temperature of the reformer, and the switching means is controlled based on this. Therefore, the thermal efficiency of the entire device can be improved while maintaining the quality of the product hydrogen.
The hydrogen production method according to claim 7, wherein in the hydrogen production method according to claim 6, at least when the temperature of the reformed gas is lower than a threshold value, a gas flow rate on the downstream side of the offgas tank in the offgas passage. The flow rate of air supplied to the combustion chamber of the reformer is adjusted based on the above.
In this hydrogen production method, at least when the temperature of the reformed gas is lower than the threshold value, the upstream side and the downstream side of the reformed gas passage are shut off by the switching means, and the upstream side and the reformed gas branch passage are connected. Communicate. As a result, the reformed gas that has not reached the predetermined hydrogen concentration is supplied as fuel to the reformer via the off-gas tank. At this time, the combustibility of the combustion chamber can be favorably maintained by adjusting the flow rate of the air supplied to the combustion chamber of the reformer based on the gas flow rate on the downstream side of the offgas tank in the offgas passage. it can.
The hydrogen production method according to claim 8 is the hydrogen production method according to claim 6, wherein at least when the temperature of the reformed gas is lower than a threshold value, the temperature of the reformed gas and the off-gas in the off-gas passage are changed. The flow rate of air supplied to the combustion chamber of the reformer is adjusted based on the gas flow rate on the downstream side of the gas tank.
In this hydrogen production method, at least when the temperature of the reformed gas is lower than the threshold value, the upstream side and the downstream side of the reformed gas passage are shut off by the switching means, and the upstream side and the reformed gas branch passage are connected. Communicate. As a result, the reformed gas that has not reached the predetermined hydrogen concentration is supplied as fuel to the reformer via the off-gas tank. At this time, the combustibility of the combustion chamber is improved by adjusting the flow rate of the air supplied to the combustion chamber of the reformer based on the temperature of the reformed gas and the gas flow rate on the downstream side of the offgas tank in the offgas passage. Can be maintained well.

Since the hydrogen production device according to the invention of claims 1 and 2 has the above-mentioned configuration, reformed gas which has not reached a predetermined hydrogen concentration can be supplied to the hydrogen purifier when the reformer is started. In addition to being prevented, the thermal efficiency of the entire device can be improved.

Further, since the hydrogen producing device according to the invention of claims 3 and 4 has the above-mentioned configuration, the combustibility of the reformed gas in the combustion chamber can be improved.

Further, since the hydrogen production method according to the invention of claims 5 and 6 has the above-mentioned configuration, the reformed gas which has not reached the predetermined hydrogen concentration when the reformer is started is supplied to the hydrogen purifier. This can be prevented and the thermal efficiency of the entire device can be improved.

Further, since the hydrogen producing method according to the invention of claims 7 and 8 has the above-mentioned configuration, the combustibility of the reformed gas in the combustion chamber can be improved.

It is a schematic block diagram which showed the hydrogen production apparatus which concerns on 1st Embodiment of this invention. It is a sectional view showing a multi-cylinder type reformer concerning a 1st embodiment of the present invention. FIG. 3 is a block diagram showing a control configuration of the hydrogen production device according to the first embodiment of the present invention. It is a schematic block diagram which showed the hydrogen production apparatus which concerns on 2nd Embodiment of this invention. It is the block diagram which showed the control structure of the hydrogen production apparatus which concerns on 2nd Embodiment of this invention.

[First Embodiment]
An example of the hydrogen production apparatus and the hydrogen production method according to the first embodiment of the present invention will be described with reference to FIGS. 1 and 2.

<Hydrogen production equipment>
As shown in FIG. 1, the hydrogen production device 10 includes a multi-cylinder reformer (hereinafter, may be referred to as a “reformer”) 12 that produces a reformed gas obtained by steam reforming hydrocarbons (city gas). A compressor 80 for compressing the reformed gas, and a hydrogen purifier 90 for purifying hydrogen gas by removing impurities from the compressed reformed gas. The hydrogen production device 10 includes a pre-pressurization water separation unit 50, a post-pressurization water separation unit 60, which separates and removes water from the reformed gas on the upstream side and the downstream side of the compressor 80, respectively, and a reformer 12 which will be described later. Combustion exhaust gas water separation unit 70 for separating and removing water from the combustion exhaust gas.

The hydrogen producing apparatus 10 produces hydrogen from a hydrocarbon raw material, and in the present embodiment, a case where city gas containing methane as a main component is used as an example of the hydrocarbon raw material will be described.

(Multiple cylinder reformer)
As shown in FIG. 2, the multi-tubular reformer 12 has a plurality of tubular walls 21, 22, 23, 24 (hereinafter, may be referred to as “cylindrical walls 21-24”) arranged in multiple layers. Have The plurality of cylindrical walls 21 to 24 are formed in, for example, a cylindrical shape or an elliptic cylindrical shape. A combustion chamber 25 is formed inside the first cylindrical wall 21 from the inner side among the plurality of cylindrical walls 21 to 24, and a burner 26 is arranged downward on the combustion chamber 25. There is. The multi-tubular reformer 12 is an example of a reformer.

Further, an air supply pipe 40 for supplying combustion air from the outside is connected to the upper end of the combustion chamber 25. A raw material branch pipe 33A branched from a raw material supply pipe 33 for further supplying city gas is connected to the burner 26. An air branch pipe 40A branched from the air supply pipe 40 is connected to the raw material branch pipe 33A. Therefore, the burner 26 is configured to be supplied with gas in which city gas is mixed with air. The air supply pipe 40 corresponds to the “air supply passage”.

A combustion exhaust gas passage 27 is formed between the first tubular wall 21 and the second tubular wall 22. A lower end portion of the combustion exhaust gas passage 27 communicates with the combustion chamber 25, and a gas exhaust pipe 28 for exhausting gas is connected to an upper end portion of the combustion exhaust gas passage 27. The combustion exhaust gas discharged from the combustion chamber 25 flows from the lower side to the upper side in the combustion exhaust gas flow path 27 and is sent to the combustion exhaust gas water separation unit 70 through the gas discharge pipe 28.

A first flow path 31 is formed between the second tubular wall 22 and the third tubular wall 23. An upper portion of the first flow passage 31 is formed as a preheating flow passage 32, and a raw material supply pipe 33 for supplying city gas and reforming water are supplied to an upper end portion of the preheating flow passage 32. Is connected to the reforming water supply pipe 34. Further, a spiral member 35 is provided between the second cylindrical wall 22 and the third cylindrical wall 23, and the preheating flow passage 32 is formed in a spiral shape by the spiral member 35. There is.

City gas can be supplied to the preheating channel 32 from the raw material supply pipe 33, and further reforming water can be supplied from the reforming water supply pipe 34. The city gas and the reforming water flow from the upper side to the lower side in the preheating channel 32, and are heat-exchanged with the combustion exhaust gas through the second cylindrical wall 22 to vaporize the water. In the preheating channel 32, the mixed gas is generated by mixing the city gas and the vapor-phase reforming water (steam).

A reforming catalyst layer 36 is provided below the preheating channel 32 in the first channel 31, and the mixed gas generated in the preheating channel 32 is supplied to the reforming catalyst layer 36. It is a configuration. The reforming catalyst layer 36 receives heat from the combustion exhaust gas flowing through the combustion exhaust gas passage 27 and undergoes a steam reforming reaction of the mixed gas to generate a reformed gas containing hydrogen as a main component.

A temperature sensor 37 that detects the temperature of the generated reformed gas is disposed downstream of the reforming catalyst layer 36 in the first flow path 31. The detection signal of the temperature sensor 37 is output to the control unit 106 described later. The temperature sensor 37 corresponds to "temperature detecting means".

Further, a second flow path 42 is formed between the third tubular wall 23 and the fourth tubular wall 24. The lower end of the second flow path 42 communicates with the lower end of the first flow path 31. A lower portion of the second flow passage 42 is formed as a reformed gas flow passage 43, and a reformed gas discharge pipe 44 is connected to an upper end portion of the second flow passage 42.

Further, a CO shift catalyst layer 45 is provided above the reformed gas passage 43 in the second passage 42, and the reformed gas generated in the reformed catalyst layer 36 is the reformed gas passage. After passing through 43, the CO conversion catalyst layer 45 is supplied. In the CO conversion catalyst layer 45, carbon monoxide contained in the reformed gas reacts with steam to be converted into hydrogen and carbon dioxide (aqueous shift reaction), and carbon monoxide in the reformed gas can be reduced. ..

Further, an oxidant gas supply pipe 46 is connected to the upper side of the CO shift catalyst layer 45, and a CO selective oxidation catalyst layer 47 is provided above the CO shift catalyst layer 45 in the second flow path 42. ing. The oxidant gas (for example, air) introduced through the oxidant gas supply pipe 46 and the reformed gas that has passed through the CO shift catalyst layer 45 are supplied to the CO selective oxidation catalyst layer 47. In the CO selective oxidation catalyst layer 47, carbon monoxide reacts with oxygen and is converted into carbon dioxide on a noble metal catalyst such as platinum or ruthenium, and carbon monoxide can be removed. The reformed gas G1 in which carbon monoxide is reduced in the CO shift catalyst layer 45 and the CO selective oxidation catalyst layer 47 is discharged through the reformed gas discharge pipe 44.

As shown in FIG. 1, the reformed gas generated in the multi-tubular reformer 12 passes through the pre-pressurization water separation unit 50, the compressor 80, the post-pressurization water separation unit 60, and the hydrogen purifier 90 in this order. Flowing. That is, in the gas flow direction, from the upstream side to the downstream side, the multi-tubular reformer 12, the pre-pressurization water separation unit 50, the compressor 80, the post-pressurization water separation unit 60, and the hydrogen purifier 90 are arranged in this order. It is arranged.

(Pre-pressurization water separator)
The downstream end of a reformed gas discharge pipe 44, into which the reformed gas G1 flows from the multi-cylinder reformer 12, is connected to the pre-pressurization water separation unit 50. A water recovery pipe 59 is connected to the bottom of the pre-pressurization water separation unit 50, and a communication channel pipe 56 is connected to the top of the pre-pressurization water separation unit 50. The reformed gas G1 is condensed and separated in the heat exchanger HE1 arranged in the reformed gas discharge pipe 44 upstream of the pre-pressurization water separation unit 50 by cooling by heat exchange with cooling water, and before the pressurization. Water (liquid phase) can be stored under the water separation unit 50. The water (liquid phase) is sent to the water recovery pipe 59. The reformed gas G2 after the water is condensed is sent to the communication flow path pipe 56.

The connecting flow pipe 56 is connected to the upstream end of the branch pipe 100 midway. The downstream end of the branch pipe 100 is connected to an offgas tank 112 described later. Further, in the communication flow path pipe 56, a first opening/closing valve 102 that connects or disconnects the pre-pressurization water separation unit 50 and the compressor 80 is disposed on the downstream side of the branch position with the branch pipe 100. .. Further, the branch pipe 100 is provided with a second opening/closing valve 104 that connects or disconnects the pre-pressurization water separation unit 50 and the offgas tank 112. The branch pipe 100 corresponds to the “reformed gas branch flow path”. The first on-off valve 102 and the second on-off valve 104 correspond to "switching means".

As shown in FIG. 3, the first opening/closing valve 102 and the second opening/closing valve 104 are configured to be opened/closed by a control signal from the control unit 106.

Specifically, when the temperature of the reformed gas detected by the temperature sensor 37 is lower than the threshold value, the first opening/closing valve 102 is closed and the second opening/closing valve 104 is opened. That is, the pre-pressurization water separation unit 50 and the compressor 80 are shut off, and the pre-pressurization water separation unit 50 and the offgas tank 112 are connected.

On the other hand, when the temperature of the reformed gas detected by the temperature sensor 37 is equal to or higher than the threshold value, the first opening/closing valve 102 is opened and the second opening/closing valve 104 is closed. That is, the pre-pressurizing water separator 50 and the compressor 80 are communicated with each other, and the pre-pressurizing water separator 50 and the offgas tank 112 are shut off.

(Compressor)
In the compressor 80, there are a communication flow passage pipe 56 through which the reformed gas G2 from the pre-pressurization water separation unit 50 flows, and a communication flow passage pipe 66 through which the reformed gas G2 supplied to the post-pressurization water separation unit 60 flows. It is connected. The compressor 80 is capable of compressing the reformed gas G2 supplied from the pre-pressurization water separation unit 50 and supplying it to the post-pressurization water separation unit 60.

(Water separation unit after pressurization)
To the post-pressurization water separation unit 60, a downstream end of a communication flow pipe 66 that allows the reformed gas G2 to flow from the compressor 80 is connected. A water recovery pipe 69 is connected to the bottom of the post-pressurization water separation unit 60, and a communication channel pipe 68 is connected to the top of the post-pressurization water separation unit 60. The reformed gas G2 is condensed and separated by cooling by heat exchange with cooling water in the heat exchanger HE2 arranged in the communication flow path pipe 66 upstream of the post-pressurization water separation section 60, and the post-pressurization water is separated. Water (liquid phase) can be stored under the separation unit 60. The water (liquid phase) is sent to the water recovery pipe 69. The reformed gas G3 after the water is condensed is sent to the communication flow path pipe 68.

(Hydrogen refiner)
The hydrogen purifier 90 has a downstream end of a communication flow pipe 68 through which the reformed gas G3 from the post-pressurization water separation unit 60 flows, an upstream end of a hydrogen supply pipe 92 to which purified hydrogen is delivered, and hydrogen purification. The upstream end of the off-gas recirculation pipe 110 to which the off-gas separated by the vessel 90 is delivered is connected.

As the hydrogen purifier 90, a PSA device is used as an example. The hydrogen purifier 90 includes a pair of adsorption tanks, one adsorption tank performs an adsorption step of adsorbing impurities on the adsorbent, and the other adsorption tank performs a desorption step of desorbing the impurities adsorbed on the adsorbent, Next, the desorption process is performed in one adsorption tank, and the adsorption process is performed in the other adsorption tank. By repeating this periodically, the reformed gas G3 is continuously separated into hydrogen and impurities containing carbon monoxide (off gas OG), and hydrogen is purified. The purified hydrogen is sent to the hydrogen supply pipe 92, can be stored in a tank (not shown), or can be sent to the hydrogen supply line.

The off gas of the hydrogen purifier 90 can be supplied to the burner 26 provided in the combustion chamber 25 of the reformer 12 via the off gas recirculation pipe 110. The offgas recirculation pipe 110 corresponds to the “offgas flow path”. In addition, the flow path of the reformed gas from the reformer 12 to the hydrogen purifier 90, specifically, the reformed gas discharge pipe 44, the pre-pressurizing water separator 50, the communication flow pipe 56, the compressor 80, The communication flow path pipe 66, the post-pressurization water separation unit 60, and the communication flow path pipe 68 correspond to the “reformed gas flow path”.

(Combustion exhaust gas water separation unit)
The downstream end of a gas exhaust pipe 28 that guides the combustion exhaust gas from the combustion exhaust gas flow path 27 of the reformer 12 is connected to the combustion exhaust gas water separation unit 70. A water recovery pipe 78 is connected to the bottom of the combustion exhaust gas water separation unit 70, and a gas discharge pipe 76 is connected to the upper portion of the combustion exhaust gas water separation unit 70. The combustion exhaust gas discharged from the combustion chamber 25 is separated and condensed in the heat exchanger HE3 arranged in the gas discharge pipe 28 upstream of the combustion exhaust gas water separation unit 70 by cooling by heat exchange with cooling water. Water (liquid phase) can be stored under the combustion exhaust gas water separation unit 70. The water (liquid phase) is sent to the water recovery pipe 78. The combustion exhaust gas after the water has been condensed is discharged from the gas discharge pipe 76 into the outside air.

The downstream ends of the water recovery pipes 59, 69, and 78 are connected to the reforming water supply pipe 34. The reforming water supply pipe 34 is provided with a water treatment device (ion exchange resin) 34A for removing dissolved ion components. The external water supply unit 17 is connected to the reforming water supply pipe 34. For example, pure water or city water is supplied from the external water supply unit 17 to the reforming water supply pipe 34.

Further, the reforming water supply pipe 34 is provided with a pump P1. The water separated by the pre-pressurization water separation unit 50, the post-pressurization water separation unit 60, the combustion exhaust gas water separation unit 70, or the water supplied from the external water supply unit 17 is sent to the multi-tubular reformer 12 by the pump P1. It is a configuration to be supplied.

<Off gas tank>
The offgas tank 112 is provided on the offgas reflux pipe 110 that connects the hydrogen purifier 90 and the burner 26 of the reformer 12 to each other. Further, the downstream end of the branch pipe 100 is connected to the offgas tank 112.

Therefore, when the first on-off valve 102 is opened and the second on-off valve 104 is closed, the off gas supplied from the hydrogen purifier 90 is temporarily stored in the off gas tank 112, and the flow rate and composition are leveled. After that, it is supplied to the burner 26 of the reformer 12.

On the other hand, when the first opening/closing valve 102 is closed and the second opening/closing valve 104 is opened, after the reformed gas supplied from the pre-pressurization water separation unit 50 is temporarily stored in the off-gas tank 112, It is configured to be supplied to the burner 26 of the reformer 12 via the off-gas recirculation pipe 110.

(Control unit)
Next, the control unit 106 that controls the opening/closing of the first opening/closing valve 102 and the second opening/closing valve 104 will be described.

As shown in FIG. 3, the control unit 106 receives the detection signal of the temperature sensor 37 and outputs control signals (a valve opening signal and a valve closing signal) to the first opening/closing valve 102 and the second opening/closing valve 104. It is a configuration. In particular, the control unit 106 outputs a valve opening signal to one of the first opening/closing valve 102 and the second opening/closing valve 104 and a valve closing signal to the other.

The control unit 106 stores a temperature threshold value of the reformed gas that determines whether or not the reformed gas (not shown) has reached a predetermined hydrogen concentration. That is, when the temperature of the reformed gas detected by the temperature sensor 37 is input, the control unit 106 is configured to compare the temperature of the reformed gas with the stored threshold value.

When the temperature of the reformed gas detected by the temperature sensor 37 is equal to or higher than the threshold value, the control unit 106 determines that the reformed gas that has reached a predetermined hydrogen concentration is generated, and then performs the first opening/closing operation. The valve 102 outputs a valve opening signal and the second opening/closing valve 104 outputs a valve closing signal.

On the contrary, when the temperature of the reformed gas detected by the temperature sensor 37 is lower than the threshold value, the control unit 106 determines that the reformed gas that has not reached the predetermined hydrogen concentration is generated, and determines the first on-off valve. A valve closing signal is output to 102 and a valve opening signal is output to the second opening/closing valve 104.

(Action)
Next, the operation of the hydrogen production device 10 and the hydrogen production method will be described.

City gas is supplied from the raw material supply pipe 33 to the multi-cylinder reformer 12. As shown in FIG. 2, the city gas supplied to the multi-cylinder reformer 12 is heated while being mixed with the reforming water in the preheating channel 32 of the multi-cylinder reformer 12, and the reforming catalyst It is supplied to the layer 36. The reforming catalyst layer 36 receives heat from the combustion exhaust gas flowing through the combustion exhaust gas passage 27 and produces a reformed gas containing hydrogen as a main component from the mixed gas by the steam reforming reaction. The reformed gas is supplied to the CO shift catalyst layer 45 through the reformed gas passage 43. In the CO conversion catalyst layer 45, carbon monoxide contained in the reformed gas reacts with steam to be converted into hydrogen and carbon dioxide, and carbon monoxide is reduced.

Further, the reformed gas that has passed through the CO conversion catalyst layer 45 is supplied to the CO selective oxidation catalyst layer 47 together with the oxidizing gas (air) supplied from the oxidizing gas supply pipe 46, and carbon monoxide is converted into oxygen on the precious metal catalyst. Reacts with and is converted to carbon dioxide, and carbon monoxide is removed. The reformed gas G1 in which carbon monoxide is reduced in the CO selective oxidation catalyst layer 47 is sent to the reformed gas discharge pipe 44.

At this time, in the combustion chamber 25 of the multi-cylinder reformer 12, the burner 26 burns a gas obtained by mixing the city gas and the air supplied from the raw material branch pipe 33A and the air branch pipe 40A. The combustion exhaust gas is supplied from the combustion chamber 25 to the combustion exhaust gas water separation unit 70 via the combustion exhaust gas flow passage 27 and the gas exhaust pipe 28. As shown in FIG. 1, the water contained in the combustion exhaust gas is cooled and condensed by heat exchange in the heat exchanger HE3, stored in the combustion exhaust gas water separation unit 70, and sent to the water recovery pipe 78. The combustion exhaust gas from which the water has been separated is discharged from the gas discharge pipe 76 into the outside air.

Here, when the hydrogen generator 10 (reformer 12) is started, it takes time for the temperature inside the reformer to reach a predetermined temperature because the burner 26 is burned in the combustion chamber 25 of the reformer 12. .. During this period, the reformed gas generated by the steam reforming in the reforming catalyst layer 36 does not reach a predetermined hydrogen concentration due to heat exchange with the combustion exhaust gas flowing through the combustion exhaust gas passage 27. The temperature of the reformed gas that has not reached the predetermined hydrogen concentration is lower than the temperature of the reformed gas that has reached the predetermined hydrogen concentration.

The temperature of the generated reformed gas is detected by the temperature sensor 37 provided on the downstream side of the reforming catalyst layer 36 in the first flow path 31. The control unit 106 determines whether the temperature of the reformed gas detected by the temperature sensor 37 is equal to or higher than a threshold value.

When the temperature of the reformed gas is less than the threshold value, it is determined that the reformed gas has not reached the predetermined hydrogen concentration, a valve closing signal is output to the first opening/closing valve 102, and the second opening/closing valve 104 is opened. Output valve signal.

As a result, the first opening/closing valve 102 is closed and the second opening/closing valve 104 is opened. As a result, the pre-pressurization water separation unit 50 and the compressor 80 are shut off, and the pre-pressurization water separation unit 50 and the off-gas tank 112 communicate with each other.

In this state, the reformed gas G1 that has been sent from the reformer 12 to the reformed gas discharge pipe 44 and has not reached the predetermined hydrogen concentration is supplied to the pre-pressurization water separation unit 50. In the pre-pressurization water separation unit 50, water condensed by cooling by heat exchange in the heat exchanger HE1 is stored and sent to the water recovery pipe 59.

The reformed gas G2 from which the water has been separated is supplied from the communication flow path pipe 56 to the offgas tank 112 via the branch pipe 100. The reformed gas G2 once stored in the off-gas tank 112 is supplied to the burner 26 of the reformer 12 via the off-gas recirculation pipe 110 and burned in the combustion chamber 25 (used for heating the reformer 12). ).

On the other hand, the control unit 106 determines that the reformed gas generated in the reformer 12 has reached a predetermined hydrogen concentration when the temperature of the reformed gas detected by the temperature sensor 37 is equal to or higher than the threshold value. Then, a valve opening signal is output to the first opening/closing valve 102 and a valve closing signal is output to the second opening/closing valve 104.

As a result, the first opening/closing valve 102 is opened and the second opening/closing valve 104 is closed. As a result, the pre-pressurization water separation unit 50 and the compressor 80 are communicated with each other, and the pre-pressurization water separation unit 50 and the offgas tank 112 are shut off.

Therefore, as shown in FIG. 1, the reformed gas G1 of a predetermined quality delivered from the reformer 12 is supplied to the pre-pressurized water separation unit 50 via the reformed gas discharge pipe 44. In the pre-pressurization water separation unit 50, water condensed by cooling by heat exchange in the heat exchanger HE1 is stored and sent to the water recovery pipe 59. The reformed gas G2 from which the water has been separated is supplied to the compressor 80 from the communication flow path pipe 56 and is compressed by the compressor 80.

The compressed reformed gas G2 is supplied from the communication flow path pipe 66 to the water separation unit 60 after pressurization. In the post-pressurization water separation unit 60, water condensed by cooling by heat exchange in the heat exchanger HE2 is stored and sent to the water recovery pipe 69. The reformed gas G3 from which water has been separated is supplied to the hydrogen purifier 90 from the communication flow path pipe 68.

The water sent from the pre-pressurization water separation unit 50, the post-pressurization water separation unit 60, and the combustion exhaust gas water separation unit 70 to the water recovery pipes 59, 69, and 78, respectively, is returned to the reforming water supply pipe 34. By driving the pump P1, the reforming water supply pipe 34 supplies the reforming water to the multi-cylinder reformer 12.

The hydrogen purifier 90 employs a pressure swing method, in which one of the pair of adsorption tanks adsorbs impurities other than hydrogen in the adsorbent, and the other adsorption tank desorbs the impurities adsorbed in the adsorbent. .. In the hydrogen purifier 90, the adsorption step and the desorption step are repeated in each adsorption tank at a constant cycle to continuously separate hydrogen and impurities from the reformed gas G3 to purify hydrogen.

Hydrogen as a product purified by the hydrogen purifier 90 is sent to the hydrogen supply pipe 92, stored in a tank (not shown), or sent to the hydrogen supply line.

On the other hand, the offgas OG discharged from the hydrogen purifier 90 is supplied to the reformer 12 via the offgas reflux pipe 110. That is, after being temporarily stored in the off-gas tank 112 provided on the off-gas recirculation pipe 110, it is supplied to the burner 26 of the reformer 12.

The offgas OG contains carbon monoxide that could not be completely removed by the reformer 12 and hydrogen that could not be completely separated by the hydrogen purifier 90. Therefore, the off gas is combusted in the combustion chamber 25 by being supplied to the burner 26 (provided for heating the reformer 12).

By the way, when the first opening/closing valve 102 is switched from the closed valve to the open valve and the second opening/closing valve 104 is switched from the open valve to the closed valve (hereinafter, referred to as “switching”), the reformed gas is pressurized before water separation unit. It takes time to reach the hydrogen purifier 90 from 50, and the off gas OG separated from the reformed gas G3 in the hydrogen purifier 90 reaches the off gas tank 112 through the off gas recirculation pipe 110.

During this time, there is no combustible gas (reformed gas G2 and off gas OG) supplied to the off gas tank 112, but the reformed gas G2 stored in the off gas tank 112 is supplied from the off gas tank 112 to the burner 26 of the reformer 12. To be done. That is, the supply of the fuel gas (the reformed gas G2 or the off gas OG) from the off gas tank 112 to the burner 26 is continued without being interrupted. Therefore, the combustion state of the burner 26 is maintained in good condition.

As described above, in the hydrogen production device 10, when the reformed gas generated in the reformer 12 does not reach the predetermined hydrogen concentration, the first opening/closing valve 102 is closed and the second opening/closing valve 104 is opened. By opening the valve, the gas can be supplied to the off-gas tank 112 provided on the off-gas recirculation pipe 110 via the branch pipe 100. As a result, the reformed gas that has not reached the predetermined hydrogen concentration is supplied from the off-gas tank 112 to the burner 26 of the reformer 12 as fuel and burned in the combustion chamber 25.

Therefore, the reformed gas that has not reached the predetermined hydrogen concentration is prevented from being supplied to the hydrogen purifier 90, and the purity (quality) of the (product) hydrogen purified by the hydrogen purifier 90 is prevented from being lowered. (High quality product hydrogen can be maintained).

In addition, compared with a hydrogen production apparatus that supplies the reformed gas that has not reached a predetermined hydrogen concentration to the burner 26 of the reformer 12 and burns it in the combustion chamber 25, the reformed gas is supplied to the flare. The thermal efficiency of the hydrogen production device 10 is improved.

Further, since the control unit 106 determines whether or not the reformed gas has reached a predetermined quality based on the temperature of the reformed gas detected by the temperature sensor 37, the quality of the reformed gas can be accurately measured. Can be determined.

Furthermore, when switching from the state where the reformed gas is being supplied to the offgas tank 112 to the state where the offgas is being supplied to the offgas tank 112 (during switching), the supply of the reformed gas to the offgas tank 112 has stopped. From the state until the off gas reaches the off gas tank 112, the reformed gas stored in the off gas tank 112 is supplied to the burner 26 of the reformer 12. Therefore, the supply of fuel gas (reforming gas or off gas) from the off-gas tank 112 to the burner 26 is not interrupted, and the burnability of the burner 26 is maintained good.

When the supply of fuel gas (reforming gas or offgas) from the offgas tank 112 to the burner 26 is cut off, it is necessary to supply city gas to the burner 26 or to increase the supply amount of city gas. .. In the hydrogen production device 10, since the supply of the fuel gas (reformed gas or off gas) from the off gas tank 112 to the burner 26 is not interrupted at the time of switching, the fuel gas (reformed gas, off gas, city gas) to the burner 26 is not supplied. The flow rate control is simplified and the thermal efficiency of the entire device is further improved.

An off-gas tank 112 is provided in the middle of the off-gas recirculation pipe 110, and the off-gas OG is temporarily stored in the off-gas tank 112, so that, for example, when the hydrogen purifier 90 is a PSA device, the flow rate and composition of the off-gas vary periodically. Can be leveled and supplied to the burner 26 of the reformer 12. Thereby, the burnability of the burner 26 can be favorably maintained.

[Second Embodiment]
A hydrogen production apparatus 200 and a hydrogen production method according to the second embodiment of the present invention will be described with reference to FIGS. 4 and 5. The same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. Further, since the hydrogen production apparatus 200 only has the flow rate detector 202 and the flow rate control valve 204 added to the hydrogen production apparatus 10, only the configuration and operation relating to the relevant portion will be described, and the same operational effect as the first embodiment will be described. Will not be described in detail.

(Constitution)
As shown in FIG. 4, the hydrogen production apparatus 200 is provided with a flow rate detector 202 on the offgas recirculation pipe 110 downstream of the offgas tank 112 for detecting the gas flow rate flowing through the offgas recirculation pipe 110. As shown in FIG. 5, the detection signal of the flow rate detector 202 is output to the control unit 106. The flow rate detector 202 corresponds to “flow rate detecting means”.

Further, as shown in FIG. 4, a flow rate control valve 204 for adjusting the flow rate of the air flowing through the air supply pipe 40 is provided on the air supply pipe 40. As shown in FIG. 5, the flow rate control valve 204 is driven by receiving a control signal from the control unit 106, and adjusts the flow rate of air flowing through the air supply pipe 40. This flow control valve 204 corresponds to an “air flow control valve”.

As shown in FIG. 5, in the control unit 106, the detection signals of the temperature sensor 37 and the flow rate detector 202 are input, and the control signals are output to the first opening/closing valve 102, the second opening/closing valve 104, and the flow rate control valve 204. It is a configuration that is done.

Further, the control unit 106 has a flow rate and a temperature of the reformed gas detected by the flow rate detector 202 and the temperature sensor 37, and an air flow rate flowing through the air supply pipe 40 corresponding thereto (opening degree of the air flow rate adjusting valve). A table indicating the correspondence relationship with is stored. This is because when the burner 26 is burned by supplying the reformed gas, the composition of the reformed gas differs depending on the temperature of the reformed gas, so that the combustion chamber 25 corresponds to the flow rate and the temperature of the reformed gas. The combustibility (air-fuel ratio) in the combustion chamber 25 is appropriately adjusted by adjusting the flow rate of air supplied to the.

Therefore, the control unit 106 outputs a control signal to the first opening/closing valve 102 and the second opening/closing valve 104 to perform opening/closing control by comparing the temperature detected by the temperature sensor 37 with a threshold value, and the opening/closing control When the reformed gas is supplied to the off-gas tank 112, a control signal referring to a table (not shown) is output to the flow rate control valve 204.

(Action)
Next, the operation of the hydrogen production apparatus 200 and the hydrogen production method will be described.
When the temperature of the reformed gas detected by the temperature sensor 37 is lower than the threshold when the reformer 12 is started, the control unit 106 of the hydrogen production apparatus 200 has reached a predetermined hydrogen concentration in the reformed gas. When it is determined that there is not, the first opening/closing valve 102 outputs a valve closing signal and the second opening/closing valve 104 outputs an opening signal. As a result, the first opening/closing valve 102 is closed and the second opening/closing valve 104 is opened.

As a result, the reformed gas generated in the reformer 12 at the time of starting the apparatus and having not reached the predetermined hydrogen concentration is supplied from the pre-pressurization water separation unit 50 to the offgas tank 112. The reformed gas is supplied from the offgas tank 112 to the burner 26 of the reformer 12 via the offgas reflux pipe 110. At this time, the flow rate detector 202 detects the flow rate of the reformed gas flowing in the off-gas recirculation pipe 110.

In the control unit 106, when the reformed gas temperature is lower than the threshold value as described above, the reformed gas is supplied to the burner 26 of the combustion chamber 25. Therefore, the temperature sensor 37 and the flow rate are referred to by referring to a table (not shown). The opening of the flow rate control valve 204 is determined from the temperature and flow rate of the reformed gas detected by the detector 202, and a control signal corresponding to this is output to the flow rate control valve 204.

The flow rate control valve 204 adjusts the opening degree to a predetermined value based on the control signal, so that the air flow rate supplied from the air supply pipe 40 to the combustion chamber 25 becomes a predetermined flow rate. As a result, the combustion state of the reformed gas supplied to the burner 26 in the combustion chamber 25 is more favorably maintained.

In this case, since the composition of the reformed gas is considered by referring to not only the flow rate of the reformed gas but also the temperature of the reformed gas, the burnability of the burner 26 in the combustion chamber 25 is further improved.

[Other]
In each of the hydrogen production devices 10 and 200, the reformer 12 is a multi-cylinder reformer, but is not limited to this. It is sufficient that the city gas can be reformed into a reformed gas containing hydrogen as a main component.

Further, in the hydrogen producing apparatuses 10 and 200, the case where the hydrogen purifier 90 is a PSA apparatus has been described, but the hydrogen purifying apparatus 90 is not limited to this as long as hydrogen can be purified from the reformed gas G3.

Further, in the hydrogen production devices 10 and 200, by providing the first opening/closing valve 102 on the downstream side of the branch position with the branch pipe 100 on the communication flow path pipe 56 and the second opening/closing valve 104 on the branch pipe 100, Although the pre-pressurizing water separation unit 50 and the compressor 80 or the off-gas tank 112 are selectively communicated with each other, the pre-pressurizing water separation is provided by providing a three-way valve at a branch position with the branch pipe 100 on the communication flow path pipe 56. The configuration may be such that the section 50 and the compressor 80 or the off-gas tank 112 are selectively communicated with each other.

In the hydrogen producing devices 10 and 200, the control unit 106 determines the hydrogen concentration of the reformed gas based on the temperature of the reformed gas detected by the temperature sensor 37, and based on the determination result, the first on-off valve 102, Although the configuration is such that the opening/closing control of the second opening/closing valve 104 is performed, the operator evaluates the hydrogen concentration of the reformed gas based on the temperature of the reformed gas, and opens/closes the first opening/closing valve 102 and the second opening/closing valve 104. It may be configured to be performed.

Furthermore, the control unit 106 may determine whether the reformed gas has reached a predetermined hydrogen concentration based on the temperature of the reformed gas. For example, whether or not the reformed gas has reached a predetermined hydrogen concentration may be determined based on the rate of temperature rise of the reformed gas.

In the hydrogen production apparatus 200, the control unit 106 adjusts the flow rate of air supplied to the combustion chamber 25 of the reformer 12 by the flow rate control valve 204 based on the temperature and flow rate of the reformed gas. A configuration may be used in which the flow rate of air supplied to the combustion chamber 25 is adjusted according to only the flow rate.

Furthermore, in the hydrogen production apparatus 200, the flow control valve 204 is adjusted to adjust the flow rate of the air supplied to the combustion chamber 25 only when the reformed gas is supplied to the burner 26 of the reformer 12. The same adjustment may be performed when the off gas is supplied to the burner 26. However, in this case, the control unit 106 stores a table showing the correspondence relationship between the flow rate of the off gas and the air flow rate (the opening degree of the flow rate control valve 204), and the table is obtained from the off gas flow rate detected by the flow rate detector 202. It is conceivable to control the flow rate control valve 204 with reference to to adjust the air flow rate.

In addition, one end of the branch pipe 100 in the hydrogen production devices 10 and 200 is connected to the pre-pressurization water separation unit 50, but the present invention is not limited to this. That is, one end of the branch pipe 100 has a pipe line (the reformed gas discharge pipe 44, the pre-pressurizing water separation unit 50, the communication flow pipe 56, the compressor 80, the communication flow passage) that connects the reformer 12 and the hydrogen purifier 90. It suffices if it is connected to the pipe 66, the post-pressurization water separation unit 60, and the connecting flow pipe 68). However, when one end of the branch pipe 100 is connected to the downstream side of the pre-pressurization water separation unit 50, the flow path until the reformed gas is supplied to the off-gas tank 112 becomes longer, which is a comparison with the present embodiment. Is disadvantageous. Further, when the branch pipe 100 is connected from the reformed gas discharge pipe 44 to the offgas tank 112, the reformed gas containing a large amount of steam (water) is supplied to the burner 26 of the reformer 12 in the present embodiment. It is more disadvantageous than the form.

Furthermore, although the other end of the branch pipe 100 is directly connected to the offgas tank 112, the present invention is not limited to this. That is, the other end of the branch pipe 100 may be connected to the upstream side of the offgas tank 112 in the offgas recirculation pipe 110.

Further, in the hydrogen production devices 10 and 200, the reformer 12 (hydrogen production devices 10 and 200) is described as being activated, but the reformed gas is not limited to the activation and reformed gas that does not reach a predetermined hydrogen concentration is reformed. It is supplied to twelve burners 26.

10, 200 Hydrogen production device 12 Multiple cylinder type reformer (reformer)
37 Temperature sensor (temperature detection means)
40 Air supply pipe (air supply flow path)
44 Reformed gas discharge pipe (reformed gas flow path)
50 Pre-pressurization water separation unit (reformed gas flow path)
56 Communication flow path pipe (reformed gas flow path)
80 Compressor (reformed gas flow path)
66 Communication flow path pipe (reformed gas flow path)
60 Water separation after pressure increase (reformed gas flow path)
68 Communication flow channel (reformed gas flow channel)
100 Branch pipe (reformed gas branch flow path)
102 First on-off valve (switching means)
104 Second on-off valve (switching means)
106 control unit 110 off-gas recirculation pipe (off-gas flow path)
112 Off-gas tank 202 Flow rate detector (flow rate detection means)
204 Flow rate control valve (air flow rate adjustment valve)

The hydrogen production apparatus according to claim 1, which is a reformer that reforms the hydrocarbon supplied as a raw material to generate a reformed gas containing hydrogen as a main component, and reforms the hydrocarbon by steam reforming. A reformer having a high quality catalyst layer and a carbon monoxide removing unit that removes carbon monoxide from the reformed gas on the downstream side of the reforming catalyst layer, and the reformer is connected to the reformer. A hydrogen purifier that purifies the product hydrogen by separating the gas into product hydrogen and off gas that is an impurity, an off gas flow path that returns the off gas as fuel from the hydrogen refiner to the combustion chamber of the reformer, and the off gas An off-gas tank that is provided on the flow path and temporarily stores the off-gas, and then supplies the off-gas to the reformer, and a reformed gas flow path from the reformer to the hydrogen purifier to branch to the off-gas tank. The reformed gas branch passage reaching the upstream side of the branch position to the reformed gas branch passage in the reformed gas passage, and one of the downstream side and the reformed gas branch passage. However, the switching means for shutting off the other and the reforming gas flow path of the reformer, which is disposed between the reforming catalyst layer and the carbon monoxide removing portion, the reforming gas The temperature detection means detects a temperature, and the control part which controls the switching means based on the temperature of the reformed gas detected by the temperature detection means .

The control unit determines whether or not the hydrogen concentration of the reformed gas has reached a predetermined concentration based on the temperature of the reformed gas detected by the temperature detection means. For example, when the temperature of the reformed gas is lower than the predetermined temperature, the control unit determines that the reformed gas has not reached the predetermined hydrogen concentration, and the switching unit determines the upstream side and the downstream side of the reformed gas flow path. Is cut off, and the upstream side and the reformed gas branch flow path are connected. As a result, the reformed gas that has not reached the predetermined hydrogen concentration is supplied as fuel from the reformer to the combustion chamber of the reformer through the offgas tank. That is, the reformed gas that has not reached the predetermined hydrogen concentration is used for heating the reformer.

On the other hand, when the temperature of the reformed gas in the reformer is equal to or higher than the predetermined temperature, the control unit determines that the reformed gas has reached the predetermined hydrogen concentration, and the switching unit upstream side of the reformed gas flow path. And the downstream side are communicated with each other, and the upstream side and the reformed gas branch flow path are blocked. As a result, the reformed gas that has reached the predetermined hydrogen concentration is supplied to the hydrogen purifier to produce product hydrogen. Further, off-gas is returned from the hydrogen purifier to the combustion chamber of the reformer as fuel via the off-gas tank, and is used for heating the reformer. Also in this case, the thermal efficiency of the entire hydrogen production apparatus is improved as compared with the hydrogen production apparatus that does not supply the offgas as fuel to the reformer.

Thereby, the thermal efficiency of the entire hydrogen production apparatus is further improved as compared with the hydrogen production apparatus that supplies the reformed gas that does not reach the predetermined hydrogen concentration to the flare.
In this way, the control unit determines whether or not the reformed gas has reached a predetermined hydrogen concentration based on the reformed gas temperature of the reformer, and controls the switching means based on this, so that the product The thermal efficiency of the entire apparatus can be improved while maintaining the quality of hydrogen.

The hydrogen production apparatus according to claim 2 is the hydrogen production apparatus according to claim 1 , wherein the off gas passage is provided on a downstream side of the off gas tank, the gas flow rate detection means for detecting a gas flow rate, and the reforming. An air supply flow path for supplying air to the combustion chamber of the reactor, and an air flow rate adjusting valve provided on the air supply flow path for adjusting the flow rate of the air supplied to the combustion chamber, and the control unit, Based on the gas flow rate detected by the gas flow rate detecting means, the air flow rate adjusting valve is controlled to adjust the air flow rate.

Hydrogen generating device according to claim 3, wherein, in the hydrogen generating device according to claim 1, wherein, provided on the downstream side of the off-gas tank of the off-gas channel, and the gas flow rate detection means for detecting the gas flow rate, the reforming An air supply flow path for supplying air to the combustion chamber of the reactor, and an air flow rate adjusting valve provided on the air supply flow path for adjusting the flow rate of the air supplied to the combustion chamber, and the control unit, Based on the temperature of the reformed gas and the gas flow rate detected by the gas flow rate detecting means, the air flow rate is adjusted by controlling the air flow rate adjusting valve.

In particular, the control unit refers to not only the flow rate of the reformed gas but also the temperature of the reformed gas to adjust the flow rate of the air supplied to the combustion chamber in accordance with the composition of the reformed gas that varies depending on the temperature. The combustibility of the chamber is further improved.
The hydrogen production apparatus according to claim 4, which is connected to the reformer that reforms the hydrocarbon supplied as a raw material to generate a reformed gas containing hydrogen as a main component, and is connected to the reformer. A hydrogen purifier that purifies the product hydrogen by separating the gas into product hydrogen and off gas that is an impurity, an off gas flow path that returns the off gas as fuel from the hydrogen refiner to the combustion chamber of the reformer, and the off gas An off-gas tank that is provided on the flow path and temporarily stores the off-gas, and then supplies the off-gas to the reformer, and a reformed gas flow path from the reformer to the hydrogen purifier to branch to the off-gas tank. The reformed gas branch passage reaching the upstream side of the branch position to the reformed gas branch passage in the reformed gas passage, and one of the downstream side and the reformed gas branch passage. However, based on the temperature of the reformed gas detected by the temperature detecting means and the temperature detecting means for detecting the temperature of the reformed gas in the reformer, the switching means, A control unit for controlling, a gas flow rate detection unit that is provided on the downstream side of the off-gas tank in the off-gas channel, detects gas flow rate, and an air supply channel that supplies air to the combustion chamber of the reformer. And an air flow rate adjusting valve provided on the air supply flow path for adjusting the flow rate of the air supplied to the combustion chamber, wherein the control unit controls the temperature of the reformed gas and the gas flow rate detecting means. Based on the detected gas flow rate, the air flow rate is adjusted by controlling the air flow rate adjusting valve.

The hydrogen production method according to claim 5 , wherein the reformer reforms the hydrocarbon supplied as a raw material to produce a reformed gas containing hydrogen as a main component, and reforms the hydrocarbon by steam reforming. A reformer having a high quality catalyst layer and a carbon monoxide removing unit that removes carbon monoxide from the reformed gas on the downstream side of the reforming catalyst layer, and the reformer is connected to the reformer. A hydrogen purifier that separates a quality gas into product hydrogen and off gas that is an impurity to purify product hydrogen; an off gas flow path that returns the off gas as a fuel from the hydrogen refiner to the combustion chamber of the reformer; An off-gas tank provided on an off-gas flow path, which temporarily stores the off-gas and then supplies it to the reformer, and a off-gas tank branched from a reformed gas flow path from the reformer to the hydrogen purifier. To the reformed gas branch channel in the reformed gas channel, and one of the downstream side or the reformed gas branch channel. The reforming gas is provided between the reforming catalyst layer and the carbon monoxide removing unit on the flow path of the reformer through which the reforming gas flows, the switching unit communicating with the reforming gas. When the temperature of the reformed gas generated in the reformer is lower than a threshold value, the reforming gas flow path is changed by the switching unit. The upstream side and the downstream side of the branch position to the reformed gas branch flow path in, the communication between the upstream side and the reformed gas branch flow path, and the reformer generated in the reformer. When the temperature of the quality gas is equal to or higher than a threshold value, the switching means connects the upstream side and the downstream side of the branch position to the reformed gas branch channel in the reformed gas channel, and the upstream side. The reformed gas branch flow path is shut off .
In this hydrogen production method, when the temperature of the reformed gas generated in the reformer is less than the threshold value, it is determined that the reformed gas has not reached a predetermined hydrogen concentration, and the switching means changes the reformed gas flow path. The upstream side and the downstream side are blocked, and the upstream side and the reformed gas branch passage are communicated. As a result, the reformed gas that has not reached the predetermined hydrogen concentration is supplied as fuel from the reformer to the combustion chamber of the reformer through the offgas tank. That is, the reformed gas that has not reached the predetermined hydrogen concentration is used for heating the reformer.

Thus, in this hydrogen production method, it is determined whether the reformed gas has reached a predetermined hydrogen concentration based on the reformed gas temperature of the reformer, and the switching means is controlled based on this. Therefore, the thermal efficiency of the entire device can be improved while maintaining the quality of the product hydrogen.
The hydrogen production method according to claim 6 , wherein in the hydrogen production method according to claim 5 , at least when the temperature of the reformed gas is lower than a threshold value, a gas flow rate on the downstream side of the offgas tank in the offgas passage. The flow rate of air supplied to the combustion chamber of the reformer is adjusted based on the above.
In this hydrogen production method, at least when the temperature of the reformed gas is lower than the threshold value, the upstream side and the downstream side of the reformed gas passage are shut off by the switching means, and the upstream side and the reformed gas branch passage are connected. Communicate. As a result, the reformed gas that has not reached the predetermined hydrogen concentration is supplied as fuel to the reformer via the off-gas tank. At this time, the combustibility of the combustion chamber can be favorably maintained by adjusting the flow rate of the air supplied to the combustion chamber of the reformer based on the gas flow rate on the downstream side of the offgas tank in the offgas passage. it can.
The method of hydrogen production according to claim 7, wherein, in the process for producing hydrogen according to claim 5, when the temperature of at least the reformed gas is less than the threshold value, the temperature of the reformed gas, the off in the off-gas channel The flow rate of air supplied to the combustion chamber of the reformer is adjusted based on the gas flow rate on the downstream side of the gas tank.
In this hydrogen production method, at least when the temperature of the reformed gas is lower than the threshold value, the upstream side and the downstream side of the reformed gas passage are shut off by the switching means, and the upstream side and the reformed gas branch passage are connected. Communicate. As a result, the reformed gas that has not reached the predetermined hydrogen concentration is supplied as fuel to the reformer via the off-gas tank. At this time, the combustibility of the combustion chamber is improved by adjusting the flow rate of the air supplied to the combustion chamber of the reformer based on the temperature of the reformed gas and the gas flow rate on the downstream side of the offgas tank in the offgas passage. Can be maintained well.
The hydrogen production method according to claim 8, wherein a reformer for reforming the hydrocarbon supplied as a raw material to generate a reformed gas containing hydrogen as a main component is connected to the reformer, and the reformer is connected to the reformer. A hydrogen purifier that purifies the product hydrogen by separating the gas into product hydrogen and off gas that is an impurity, an off gas flow path that returns the off gas as fuel from the hydrogen refiner to the combustion chamber of the reformer, and the off gas An off-gas tank that is provided on the flow path and temporarily stores the off-gas, and then supplies the off-gas to the reformer, and a reformed gas flow path from the reformer to the hydrogen purifier to branch to the off-gas tank. The reformed gas branch passage reaching the upstream side of the branch position to the reformed gas branch passage in the reformed gas passage, and one of the downstream side and the reformed gas branch passage. However, when the temperature of the reformed gas generated in the reformer is less than the threshold value, the reforming gas flow path is changed by the switching unit. The upstream side and the downstream side of the branch position to the reformed gas branch flow path in, the communication between the upstream side and the reformed gas branch flow path, and the reformer generated in the reformer. When the temperature of the quality gas is equal to or higher than a threshold value, the switching means connects the upstream side and the downstream side of the branch position to the reformed gas branch channel in the reformed gas channel, and the upstream side. While blocking the reformed gas branch passage, at least when the temperature of the reformed gas is less than a threshold value, the temperature of the reformed gas, and the gas on the downstream side of the off gas tank in the off gas passage. The flow rate of air supplied to the combustion chamber of the reformer is adjusted based on the flow rate.

Since the hydrogen production apparatus according to the inventions of claims 1 and 4 has the above-mentioned configuration, reformed gas that has not reached a predetermined hydrogen concentration can be supplied to the hydrogen purifier when the reformer is started. In addition to being prevented, the thermal efficiency of the entire device can be improved.

Further, since the hydrogen production device according to the invention of claims 2 to 4 has the above-mentioned configuration, it is possible to improve the combustibility of the reformed gas in the combustion chamber.

Further, since the hydrogen producing method according to the invention of claims 5 and 8 is configured as described above, the reformed gas that has not reached the predetermined hydrogen concentration when the reformer is started is supplied to the hydrogen purifier. This can be prevented and the thermal efficiency of the entire device can be improved.

Further, since the hydrogen production method according to the inventions of claims 6 to 8 has the above-mentioned configuration, the combustibility of the reformed gas in the combustion chamber can be improved.

The hydrogen production apparatus according to claim 1, which is a reformer that reforms the hydrocarbon supplied as a raw material to generate a reformed gas containing hydrogen as a main component, and reforms the hydrocarbon by steam reforming. A reformer having a high quality catalyst layer and a carbon monoxide removing unit that removes carbon monoxide from the reformed gas on the downstream side of the reforming catalyst layer, and the reformer is connected to the reformer. A hydrogen purifier that purifies the product hydrogen by separating the gas into product hydrogen and off gas that is an impurity, an off gas flow path that returns the off gas as fuel from the hydrogen refiner to the combustion chamber of the reformer, and the off gas An off-gas tank that is provided on the flow path and temporarily stores the off-gas, and then supplies the off-gas to the reformer, and a reformed gas flow path from the reformer to the hydrogen purifier to branch to the off-gas tank. The reformed gas branch passage reaching the upstream side of the branch position to the reformed gas branch passage in the reformed gas passage, and one of the downstream side and the reformed gas branch passage. However, the switching means for shutting off the other and the reforming gas flow path of the reformer, which is disposed between the reforming catalyst layer and the carbon monoxide removing portion, the reforming gas Temperature detection means for detecting the temperature, based on the temperature of the reformed gas detected by the temperature detection means, a control unit for controlling the switching means, downstream of the off-gas tank of the off-gas passage A gas flow rate detection unit that is provided to detect a gas flow rate, an air supply channel that supplies air to the combustion chamber of the reformer, and an air flow rate that is provided on the air supply channel and is supplied to the combustion chamber. And an air flow rate adjusting valve for adjusting the air flow rate adjusting valve, wherein the control unit controls the air flow rate adjusting valve based on the temperature of the reformed gas and the gas flow rate detected by the gas flow rate detecting means. Adjust the air flow rate .

Further, in this hydrogen production device, the switching means is switched based on the temperature of the reformed gas, so that the reformed gas that has not reached the predetermined hydrogen concentration is supplied as fuel to the reformer via the off-gas tank. It At this time, the flow rate of the reformed gas is detected by the gas flow rate detection means provided in the off-gas flow path, and the control section adjusts the flow rate of the air flowing into the combustion chamber of the reformer based on the flow rate and the temperature of the reformed gas. By doing so, the combustibility of the combustion chamber is maintained well.

In particular, the control unit refers to not only the flow rate of the reformed gas but also the temperature of the reformed gas to adjust the flow rate of the air supplied to the combustion chamber in accordance with the composition of the reformed gas that varies depending on the temperature. The combustibility of the chamber is further improved.
The hydrogen production apparatus according to claim 2 is connected to a reformer that reforms hydrocarbons supplied as a raw material to generate a reformed gas containing hydrogen as a main component, and the reformer is connected to the reformer. A hydrogen purifier that purifies the product hydrogen by separating the gas into product hydrogen and off gas that is an impurity, an off gas flow path that returns the off gas as fuel from the hydrogen refiner to the combustion chamber of the reformer, and the off gas An off-gas tank that is provided on the flow path and temporarily stores the off-gas, and then supplies the off-gas to the reformer, and a reformed gas flow path from the reformer to the hydrogen purifier to branch to the off-gas tank. The reformed gas branch passage reaching the upstream side of the branch position to the reformed gas branch passage in the reformed gas passage, and one of the downstream side and the reformed gas branch passage. However, based on the temperature of the reformed gas detected by the temperature detecting means and the temperature detecting means for detecting the temperature of the reformed gas in the reformer, the switching means, A control unit for controlling, a gas flow rate detection unit that is provided on the downstream side of the off-gas tank in the off-gas channel, detects gas flow rate, and an air supply channel that supplies air to the combustion chamber of the reformer. And an air flow rate adjusting valve provided on the air supply flow path for adjusting the flow rate of the air supplied to the combustion chamber, wherein the control unit controls the temperature of the reformed gas and the gas flow rate detecting means. Based on the detected gas flow rate, the air flow rate adjusting valve is controlled to adjust the air flow rate.

The hydrogen producing method according to claim 3 , wherein the reformer reforms the hydrocarbon supplied as a raw material to generate a reformed gas containing hydrogen as a main component, and reforms the hydrocarbon by steam reforming. A reformer having a high quality catalyst layer and a carbon monoxide removing unit that removes carbon monoxide from the reformed gas on the downstream side of the reforming catalyst layer, and the reformer is connected to the reformer. A hydrogen purifier that separates a quality gas into product hydrogen and off gas that is an impurity to purify product hydrogen; an off gas flow path that returns the off gas as a fuel from the hydrogen refiner to the combustion chamber of the reformer; An off-gas tank provided on an off-gas flow path, which temporarily stores the off-gas and then supplies it to the reformer, and a off-gas tank branched from a reformed gas flow path from the reformer to the hydrogen purifier. To the reformed gas branch channel in the reformed gas channel, and one of the downstream side or the reformed gas branch channel. The reforming gas is provided between the reforming catalyst layer and the carbon monoxide removing unit on the flow path of the reformer through which the reforming gas flows, the switching unit communicating with the reforming gas. When the temperature of the reformed gas generated in the reformer is lower than a threshold value, the reforming gas flow path is changed by the switching unit. The upstream side and the downstream side of the branch position to the reformed gas branch flow path in, the communication between the upstream side and the reformed gas branch flow path, and the reformer generated in the reformer. When the temperature of the quality gas is equal to or higher than the threshold value, the switching means connects the upstream side and the downstream side of the branch position to the reformed gas branch channel in the reformed gas channel, and the upstream side. While blocking the reformed gas branch passage , at least when the temperature of the reformed gas is less than a threshold value, the temperature of the reformed gas, and the gas on the downstream side of the off gas tank in the off gas passage. The flow rate of air supplied to the combustion chamber of the reformer is adjusted based on the flow rate .
In this hydrogen production method, when the temperature of the reformed gas generated in the reformer is lower than the threshold value, it is determined that the reformed gas has not reached a predetermined hydrogen concentration, and the switching means changes the reformed gas flow path. The upstream side and the downstream side are blocked, and the upstream side and the reformed gas branch passage are communicated. As a result, the reformed gas that has not reached the predetermined hydrogen concentration is supplied as fuel from the reformer to the combustion chamber of the reformer via the offgas tank. That is, the reformed gas that has not reached the predetermined hydrogen concentration is used for heating the reformer.

Thus, in this hydrogen production method, it is determined whether the reformed gas has reached a predetermined hydrogen concentration based on the reformed gas temperature of the reformer, and the switching means is controlled based on this. Therefore, the thermal efficiency of the entire device can be improved while maintaining the quality of the product hydrogen.
Further, in this hydrogen production method, at least when the temperature of the reformed gas is lower than the threshold value, the switching means shuts off the upstream side and the downstream side of the reformed gas passage, and the upstream side and the reformed gas branch passage. And communicate with. As a result, the reformed gas that has not reached the predetermined hydrogen concentration is supplied as fuel to the reformer via the off-gas tank. At this time, the combustibility of the combustion chamber is improved by adjusting the flow rate of the air supplied to the combustion chamber of the reformer based on the temperature of the reformed gas and the gas flow rate on the downstream side of the offgas tank in the offgas passage. Can be maintained well.
The hydrogen production method according to claim 4 , wherein a reformer for reforming the hydrocarbon supplied as a raw material to generate a reformed gas containing hydrogen as a main component, and a reformer connected to the reformer, A hydrogen purifier that purifies the product hydrogen by separating the gas into product hydrogen and off gas that is an impurity, an off gas flow path that returns the off gas as fuel from the hydrogen refiner to the combustion chamber of the reformer, and the off gas An off-gas tank that is provided on the flow path and temporarily stores the off-gas, and then supplies the off-gas to the reformer, and a reformed gas flow path from the reformer to the hydrogen purifier to branch to the off-gas tank. The reformed gas branch passage reaching the upstream side of the branch position to the reformed gas branch passage in the reformed gas passage, and one of the downstream side and the reformed gas branch passage. However, when the temperature of the reformed gas generated in the reformer is less than the threshold value, the reforming gas flow path is changed by the switching unit. The upstream side and the downstream side of the branch position to the reformed gas branch flow path in, the communication between the upstream side and the reformed gas branch flow path, and the reformer generated in the reformer. When the temperature of the quality gas is equal to or higher than a threshold value, the switching means connects the upstream side and the downstream side of the branch position to the reformed gas branch channel in the reformed gas channel, and the upstream side. While blocking the reformed gas branch passage, at least when the temperature of the reformed gas is less than a threshold value, the temperature of the reformed gas, and the gas on the downstream side of the off gas tank in the off gas passage. The flow rate of air supplied to the combustion chamber of the reformer is adjusted based on the flow rate.

Since the hydrogen production apparatus according to the first and second aspects of the present invention is configured as described above, reformed gas that has not reached a predetermined hydrogen concentration at the time of starting the reformer can be supplied to the hydrogen purifier. In addition to being prevented, the thermal efficiency of the entire device can be improved.

Further, since the hydrogen production device according to the invention of claims 1 and 2 has the above-mentioned configuration, it is possible to improve the combustibility of the reformed gas in the combustion chamber.

Further, since the method for producing hydrogen according to the third and fourth aspects of the present invention is configured as described above, the reformed gas that has not reached the predetermined hydrogen concentration when the reformer is started is supplied to the hydrogen purifier. This can be prevented and the thermal efficiency of the entire device can be improved.

Further, since the hydrogen producing method according to the inventions of claims 3 and 4 has the above-mentioned configuration, the combustibility of the reformed gas in the combustion chamber can be improved.

Claims (8)

A reformer for reforming the hydrocarbon supplied as a raw material to generate a reformed gas containing hydrogen as a main component,
A hydrogen purifier that is connected to the reformer and separates the reformed gas into product hydrogen and off gas that is an impurity to purify product hydrogen;
An offgas flow path for returning the offgas as fuel from the hydrogen purifier to the combustion chamber of the reformer,
An off-gas tank provided on the off-gas channel, which temporarily stores the off-gas and then supplies the off-gas to the reformer,
A reformed gas branch passage branched from the reformed gas passage from the reformer to the hydrogen purifier to the off-gas tank,
An upstream side of a branch position to the reformed gas branch channel in the reformed gas channel, a switching unit that communicates with either the downstream side or the reformed gas branch channel, and shuts off from the other.
Hydrogen production device equipped with. Temperature detection means for detecting the temperature of the reformed gas in the reformer,
Based on the temperature of the reformed gas detected by the temperature detection means, a control unit for controlling the switching means,
The hydrogen production apparatus according to claim 1, further comprising: A gas flow rate detection unit that is provided on the downstream side of the off gas tank in the off gas flow path and detects a gas flow rate,
An air supply flow path for supplying air to the combustion chamber of the reformer,
An air flow rate adjusting valve that is provided on the air supply flow path and adjusts the flow rate of air supplied to the combustion chamber,
3. The hydrogen production apparatus according to claim 2, further comprising: a control unit configured to control the air flow rate adjusting valve to adjust the air flow rate based on the gas flow rate detected by the gas flow rate detecting unit. A gas flow rate detection unit that is provided on the downstream side of the off gas tank in the off gas flow path and detects a gas flow rate,
An air supply flow path for supplying air to the combustion chamber of the reformer,
An air flow rate adjusting valve that is provided on the air supply flow path and adjusts the flow rate of air supplied to the combustion chamber,
The control unit adjusts the air flow rate by controlling the air flow rate control valve based on the temperature of the reformed gas and the flow rate of the reformed gas detected by the gas flow rate detection means. Item 2. The hydrogen production device according to item 2. Using the hydrogen production apparatus according to claim 1,
When the hydrogen concentration of the reformed gas generated in the reformer has not reached a predetermined hydrogen concentration, the switching position of the reformed gas flow passage to the reformed gas branch flow passage in the reformed gas flow passage by the switching unit. The upstream side and the downstream side are cut off from each other, and the upstream side and the reformed gas branch passage are communicated with each other,
When the hydrogen concentration of the reformed gas generated in the reformer reaches a predetermined hydrogen concentration, the switching unit causes the reformed gas passage to branch to the reformed gas branch passage from the branch position. Also, a method for producing hydrogen in which the upstream side and the downstream side are communicated with each other and the upstream side and the reformed gas branch flow path are blocked from each other. Using the hydrogen production apparatus according to claim 1,
When the temperature of the reformed gas generated in the reformer is lower than a threshold value, the switching means upstream and downstream of the branch position of the reformed gas passage to the reformed gas branch passage. And to connect the upstream side and the reformed gas branch flow path,
When the temperature of the reformed gas generated in the reformer is equal to or higher than a threshold value, upstream and downstream of the branch position in the reformed gas flow passage in the reformed gas flow passage by the switching unit. And a reformed gas branch flow path are cut off from each other. At least when the temperature of the reformed gas is lower than a threshold value, the flow rate of air supplied to the combustion chamber of the reformer is adjusted based on the gas flow rate on the downstream side of the offgas tank in the offgas passage. Item 6. The method for producing hydrogen according to Item 6. When the temperature of the reformed gas is at least lower than the threshold value, the reformed gas is introduced into the combustion chamber of the reformer based on the temperature of the reformed gas and the gas flow rate on the downstream side of the offgas tank in the offgas passage. The method for producing hydrogen according to claim 6, wherein the flow rate of the supplied air is adjusted.