JP7195942B2 - Hydrogen production system, hydrogen production device control program, and hydrogen production device cleaning method - Google Patents

Description

The present invention relates to a hydrogen production system having a plurality of hydrogen production devices, a hydrogen production device control program, and a cleaning method for a hydrogen production device.

Conventionally, as a hydrogen production device for obtaining hydrogen, after reforming the raw material hydrocarbon into a reformed gas in a reformer, it is supplied to a PSA (Pressure Swing Adsorption) device to purify the reformed gas. A method for obtaining pure hydrogen is known (see, for example, Patent Document 1). As described above, when using a hydrogen purifier, substances other than hydrogen may remain in the hydrogen purifier, so it is necessary to clean the hydrogen purifier to remove impurities in the hydrogen purifier at the time of startup, etc. done.

JP 2017-88490 A

Hydrogen gas is used for the above cleaning, and if a hydrogen gas tank or the like is installed to supply the hydrogen gas for cleaning, the device configuration becomes complicated. It is desired to clean the hydrogen purifier with a simple configuration.

The present invention has been made in view of the above circumstances, and provides a hydrogen production system, a hydrogen production device control program, and a method of cleaning a hydrogen production device that can clean a hydrogen purifier with a simple configuration. intended to

In the hydrogen production system according to claim 1 of the present invention, the reformed gas from a reformer that reforms a raw material to generate a reformed gas containing hydrogen as a main component is divided into a hydrogen-rich gas and an off-gas containing impurities. a plurality of hydrogen production apparatuses each having a hydrogen purifier having an off-gas delivery path for separating and delivering the off-gas and a hydrogen gas delivery path for delivering the hydrogen-rich gas; and a cleaning gas supply path for supplying to the hydrogen purifier of another hydrogen production device.

A hydrogen production system according to claim 1 comprises a plurality of hydrogen production devices. In each hydrogen production apparatus, the raw material is reformed in the reformer to produce a reformed gas, and the reformed gas is separated into a hydrogen-rich gas and an off-gas containing impurities in the hydrogen purifier. The hydrogen purifier has an off-gas delivery path for delivering the separated off-gas and a hydrogen gas delivery path for delivering the hydrogen-rich gas. Between the plurality of hydrogen production apparatuses, a cleaning gas supply path for supplying the hydrogen-rich gas sent from the hydrogen gas delivery path to the hydrogen purifier of the other hydrogen production apparatus is provided.

According to the hydrogen production system of claim 1, the hydrogen-rich gas is supplied from some of the plurality of hydrogen production devices to the hydrogen purifiers of the other hydrogen production devices through the other device cleaning gas supply path. can do. Therefore, hydrogen gas for cleaning the hydrogen purifier can be obtained from another device, and the hydrogen purifier can be cleaned with a simple configuration.

In the hydrogen production system according to claim 2, each of the hydrogen purifiers of the plurality of hydrogen production devices has an adsorption unit that adsorbs the impurities, and among the plurality of hydrogen production devices, Stopping the reformed gas from flowing into the adsorption unit of the cleaning hydrogen production apparatus, and supplying a cleaning gas supply path from another hydrogen production apparatus, which is different from the hydrogen production apparatus to be cleaned, among the plurality of hydrogen production apparatuses. a cleaning execution unit that supplies the hydrogen-rich gas to the adsorption unit of the hydrogen producing apparatus to be cleaned via the cleaning unit as a cleaning gas for other equipment to perform cleaning processing of the adsorption unit.

In the hydrogen production system according to claim 2, the cleaning process is performed by the cleaning execution unit. In the cleaning process, the reformed gas is stopped from flowing into the adsorption section of the hydrogen production device to be cleaned, and hydrogen is supplied from the other hydrogen production device to the adsorption section of the hydrogen production device to be cleaned through the other cleaning gas supply passage. This is done by supplying the rich gas as the other machine cleaning gas. In this way, by using the hydrogen-rich gas refined by another hydrogen production apparatus for cleaning the hydrogen purifier of the hydrogen production apparatus to be cleaned, the hydrogen purifier can be cleaned with a simple configuration.

In the hydrogen production system according to claim 3, the cleaning execution unit sends the hydrogen-rich gas after being used in the cleaning process from the hydrogen purifier of the hydrogen production apparatus to be cleaned to the offgas delivery path.

According to the hydrogen production system of claim 3, the hydrogen-rich gas after being used in the cleaning process is delivered to the off-gas path, so the hydrogen-rich gas delivered together with the impurities is replaced with the off-gas separated in the normal hydrogen refining process. can be processed in the same way as

In the hydrogen production system according to claim 4, the cleaning execution unit performs the cleaning when the hydrogen purity of the hydrogen-rich gas in the hydrogen gas delivery path of the other hydrogen production device is equal to or higher than the cleaning purity lower than the threshold value of the product hydrogen purity. and supplying the hydrogen-rich gas to the hydrogen purifier of the hydrogen-producing device to be cleaned as a cleaning gas for cleaning the hydrogen-producing device to be cleaned.

According to the hydrogen production system of claim 4, since the hydrogen-rich gas having a cleaning purity or higher is supplied as the cleaning gas for cleaning the hydrogen production device to be cleaned, the cleaning process can be performed effectively.

According to a fifth aspect of the present invention, there is provided a method for cleaning a hydrogen production apparatus, in which a reformed gas containing hydrogen as a main component supplied from a reformer is supplied from a reformer in some of the plurality of hydrogen production apparatuses. separates it into a hydrogen-rich gas and an off-gas containing impurities, sends the off-gas to an off-gas delivery line, sends the hydrogen-rich gas to the hydrogen gas delivery line, and delivers it from the hydrogen gas delivery line of the hydrogen production apparatus of 1. The hydrogen-rich gas thus obtained is supplied to the hydrogen purifier of the hydrogen production device to be cleaned as a cleaning gas for the hydrogen production device to be cleaned among the plurality of hydrogen production devices, and is subjected to cleaning treatment. .

In the method for cleaning a hydrogen production device according to claim 5, the hydrogen-rich gas refined by the hydrogen purifier of a part of the hydrogen production devices out of the plurality of hydrogen production devices is removed from the other hydrogen production device to be cleaned. Used as machine cleaning gas. Therefore, hydrogen gas for cleaning the hydrogen purifier can be obtained from another device, and the hydrogen purifier can be cleaned with a simple configuration. Note that the partial hydrogen production device may be one of a plurality of hydrogen production devices, or may be two or more devices, but does not mean all devices.

A method for cleaning a hydrogen production device according to claim 6, wherein the hydrogen purifier of each of the plurality of hydrogen production devices has an adsorption unit that adsorbs the impurities, and the cleaning process includes the hydrogen production device to be cleaned. stop the inflow of the reformed gas into the adsorption unit of the hydrogen-rich gas from another hydrogen-producing device different from the hydrogen-producing device to be cleaned to the adsorption member of the hydrogen-producing device to be cleaned as a cleaning gas for other devices. supply.

According to the method for cleaning a hydrogen production device according to claim 6, the reformed gas is stopped from flowing into the adsorption section of the hydrogen production device to be cleaned, and the hydrogen to be cleaned is removed from another hydrogen production device different from the hydrogen production device to be cleaned. The cleaning process can be performed by supplying the hydrogen-rich gas to the adsorption unit of the manufacturing apparatus as the cleaning gas for the other machine.

According to a seventh aspect of the present invention, there is provided a method for cleaning a hydrogen production apparatus, in which the hydrogen-rich gas after being used in the cleaning process is delivered from the hydrogen purifier of the hydrogen production apparatus to be cleaned to the offgas delivery path.

According to the method for cleaning a hydrogen production apparatus according to claim 7, the hydrogen-rich gas that has been used in the cleaning process is delivered to the off-gas path. It can be treated like the separated off-gas.

A cleaning method for a hydrogen production device according to claim 8, wherein the hydrogen purity of the hydrogen-rich gas in the hydrogen gas delivery passage of another hydrogen production device different from the hydrogen production device to be cleaned is lower than the threshold value of the product hydrogen purity. In the above case, the hydrogen-rich gas is supplied to the hydrogen purifier of the hydrogen-producing device to be cleaned as a cleaning gas for cleaning the hydrogen-producing device to be cleaned.

According to the method for cleaning a hydrogen production apparatus according to claim 8, the hydrogen-rich gas having a cleaning purity or higher is supplied as the cleaning gas for cleaning the hydrogen production apparatus to be cleaned, so that the cleaning process can be performed effectively. .

A hydrogen production apparatus control program according to claim 9 is a program for causing a computer to function as each part of the hydrogen production apparatus according to any one of claims 1 to 4.

According to the hydrogen generator control program according to claim 9, the hydrogen-rich gas is supplied from some of the plurality of hydrogen generators to the hydrogen purifiers of the other hydrogen generators through the other-machine cleaning gas supply path. Each hydrogen production device can be controlled to supply

According to the present invention, it is possible to clean the hydrogen purifier with a simple configuration.

1 is a schematic configuration diagram showing a hydrogen production device according to an embodiment; FIG. FIG. 2 is a cross-sectional view showing a multi-cylinder reformer of the hydrogen production apparatus according to the present embodiment; It is a block diagram of the control part of the hydrogen production apparatus which concerns on this embodiment, and its connection member. 1 is a schematic configuration diagram of a hydrogen purifier according to an embodiment; FIG. 4 is a flow chart showing the flow of other machine cleaning processing according to the present embodiment. FIG. 11 is a flow chart showing the flow of other machine cleaning processing according to a modification of the present embodiment; FIG. It is a schematic block diagram which showed a part of hydrogen production system which concerns on the modification of this embodiment.

An example of a hydrogen production device system according to an embodiment of the present invention will be described with reference to the drawings.

A hydrogen production system 70 of this embodiment includes a plurality of hydrogen production devices 10 . FIG. 1 shows an example in which two hydrogen production apparatuses 10 are provided, and each hydrogen production apparatus 10 has the same configuration. In this embodiment, the hydrogen generators 10 are referred to as hydrogen generators 10A and 10B in order to distinguish between them.

A hydrogen production apparatus 10 (10A, 10B) according to this embodiment includes a multi-cylinder reformer 12, a compressor 14, a hydrogen purifier 16, and an off-gas tank 18. In addition, a pre-pressurization water separation section 30 , a post-pressurization water separation section 32 , and a combustion exhaust gas water separation section 34 are provided. This hydrogen production apparatus 10 produces hydrogen from a hydrocarbon feedstock, and in this embodiment, a case where city gas containing methane as a main component is used as an example of the hydrocarbon feedstock will be described. Note that FIG. 1 schematically shows the configuration of the hydrogen production device 10, and the hydrogen production device 10 may include other configurations.

The hydrogen production system 70 also includes a control unit 60 that controls each hydrogen production device 10 (see FIG. 3). The control unit 60 has a CPU (Central Processing Unit: processor) 60A, a ROM (Read Only Memory) 60B, a RAM (Random Access Memory) 60C, a storage 60D, and an input/output interface (I/F) 60E. Each component is communicatively connected to each other via a bus 62 .

The CPU 60A is a central processing unit that executes various programs and controls each section. That is, the CPU 60A reads a program from the ROM 60B or the storage 60D and executes the program using the RAM 60C as a work area. The CPU 60A performs control of the above components and various arithmetic processing according to programs recorded in the ROM 60B or the storage 60D.

The ROM 60B stores various programs and various data. RAM 60C temporarily stores programs or data as a work area. The storage 60D is configured by a HDD (Hard Disk Drive) or an SSD (Solid State Drive), and stores various programs including an operating system and various data. In the present embodiment, the ROM 60B or the storage 60D stores programs and the like for cleaning the hydrogen purifiers 16 of the hydrogen production apparatuses 10A and 10B, which will be described later. The input/output I/F 60E is connected to on-off valves V1 to V5, a hydrogen purity sensor 46, a first switching section 15 and a second switching section 17, which will be described later, of each hydrogen production device 10 via signal lines.

(reformer)
As shown in FIG. 2, the multiple cylindrical reformer 12 has multiple cylindrical walls 20A, 20B, 20C, and 20D. A plurality of cylindrical walls 20A, 20B, 20C, and 20D are formed in a cylindrical shape or an elliptical cylindrical shape, for example. A combustion section 21, which is a combustion space, is formed inside the first cylindrical wall 20A from the inside among the plurality of cylindrical walls 20A, 20B, 20C, and 20D. A flue gas flow path 23 is formed between the first tubular wall 20A and the second tubular wall 20B. A first flow path 24 is formed between the second tubular wall 20B and the third tubular wall 20C. Furthermore, a second flow path 25 is formed between the third tubular wall 20C and the fourth tubular wall 20D. Note that the multiple cylinder reformer 12 is an example of a reformer, and other forms of reformers may be used.

An upper portion of the first flow path 24 is formed as a preheating flow path 24A, and the preheating flow path 24A is provided with a spiral member 24B. The helical member 24B forms the preheating flow path 24A in a helical shape. A raw material supply pipe P1 for supplying city gas as a raw material and a reforming water supply pipe P9 for supplying reforming water are connected to the upper end of the preheating channel 24A. City gas is supplied from the raw material supply pipe P1 and reforming water is supplied from the reforming water supply pipe P9 to the preheating flow path 24A. The city gas and the reformed water flow through the preheating channel 24A from the upper side to the lower side, heat exchange with the combustion exhaust gas through the second cylindrical wall 20B, and the water is vaporized. In the preheating flow path 24A, a mixed gas is generated by mixing the city gas and gas-phase reforming water (steam).

In the present embodiment, city gas is used as a raw material, but any gas that can be steam reformed is not particularly limited, and a hydrocarbon fuel can be used. Examples of hydrocarbon fuels include natural gas, LP gas (liquefied petroleum gas), reformed coal gas, and lower hydrocarbon gas.

Below the preheating channel 24A in the first channel 24, a reforming catalyst layer 24C is provided. The reforming catalyst layer 24C is provided with a catalyst for steam reforming city gas to generate a reformed gas containing hydrogen as a main component. The mixed gas generated in the preheating flow path 24A is supplied to the reforming catalyst layer 24C. In the reforming catalyst layer 24C, the mixed gas is heated by the flue gas flowing through the flue gas passage 23, and a reformed gas containing hydrogen as a main component is generated by a steam reforming reaction.

The second flow path 25 is arranged radially outside the first flow path 24 , and the lower end of the second flow path 25 communicates with the lower end of the first flow path 24 . A CO shift conversion catalyst layer 26 and a CO selective oxidation catalyst layer 27 are formed in the second channel 25 at positions corresponding to the preheating channel 24A. In the CO conversion catalyst layer 26, carbon monoxide contained in the reformed gas reacts with water vapor to be converted into hydrogen and carbon dioxide, thereby reducing carbon monoxide.

The CO selective oxidation catalyst layer 27 is arranged downstream of the CO conversion catalyst layer 26 . An oxidant gas supply pipe P2B for supplying an oxidant gas is connected between the CO transformation catalyst layer 26 and the CO selective oxidation catalyst layer 27 . In the CO selective oxidation catalyst layer 27, carbon monoxide reacts with oxygen to be converted into carbon dioxide, and carbon monoxide is removed. A reformed gas discharge pipe P3 is connected to the upper end portion of the second flow path 25 on the downstream side of the CO selective oxidation catalyst layer 27 . After carbon monoxide is removed by the CO selective oxidation catalyst layer 27, the reformed gas is sent out from the reformed gas discharge pipe P3.

Although the CO selective oxidation catalyst layer 27 is provided in the present embodiment, the CO selective oxidation catalyst layer 27 is not essential, and a configuration in which the CO selective oxidation catalyst layer 27 is not provided is also possible. In this case, the oxidant gas supply pipe P2B is also unnecessary.

A burner 22 is arranged downward in the upper portion of the combustion section 21 . An off-gas pipe P7 is connected to the burner 22, and off-gas, which will be described later, is supplied as fuel from the off-gas pipe P7. Furthermore, an air supply pipe P2 for supplying combustion air is connected to the upper end of the combustion section 21 . The burner 22 is also connected to a raw material branch pipe P1A branched from the raw material supply pipe P1. An air branch pipe P2A branched from the air supply pipe P2 is connected to the raw material branch pipe P1A. Gas in which air is mixed with city gas is supplied to the burner 22 separately from the off-gas. Either one or both of off-gas and town gas for combustion are supplied as required.

The combustion exhaust gas flow path 23 is formed radially outside the combustion section 21 , and the lower end portion of the combustion exhaust gas flow path 23 communicates with the combustion section 21 . A gas discharge pipe P10 for discharging gas is connected to the upper end portion of the combustion exhaust gas flow path 23 . The gas discharge pipe P10 is connected to the upper end surface of the multiple cylinder reformer 12 . The combustion exhaust gas discharged from the combustion section 21 flows from the bottom to the top through the combustion exhaust gas flow path 23 and is discharged to the outside of the multiple cylinder reformer 12 through the gas discharge pipe P10.

The reformed gas sent from the multiple cylinder reformer 12 to the reformed gas discharge pipe P3 is, as shown in FIG. It flows through the hydrogen purifier 16 in this order. That is, from the upstream side to the downstream side in the direction of gas flow, the multiple cylinder reformer 12, the pre-pressurization water separator 30, the compressor 14, the post-pressurization water separator 32, and the hydrogen purifier 16 are arranged in this order. are placed.

(separation section before boosting)
The pre-pressurization water separation unit 30 has a gas chamber 30A in the upper portion and a liquid chamber 30B in the lower portion. A downstream end of a reformed gas discharge pipe P3 is connected to the gas chamber 30A. The gas chamber 30A is also connected to the upstream end of the communication channel pipe P4. A water delivery port 30C is formed at the bottom of the liquid chamber 30B, and a reformed gas water pipe P8A is connected to the water delivery port 30C. The water vapor in the reformed gas is cooled and condensed in the heat exchanger HE<b>1 arranged upstream of the pre-pressurization water separation section 30 . The water separated from the reformed gas by condensation is stored in the liquid chamber 30B and sent to the reformed gas water pipe P8A.

(compressor)
Connected to the compressor 14 are a communication channel pipe P4 through which the reformed gas from the pre-pressurization water separation unit 30 flows, and a communication channel pipe P5 through which the reformed gas supplied to the post-pressurization water separation unit 32 flows. ing. The compressor 14 compresses and pressurizes the reformed gas supplied from the pre-pressurization water separation unit 30 , and supplies the pressurized pressurized gas to the post-pressurization water separation unit 32 .

(separation section after boosting)
The post-pressurization water separation section 32 has a gas chamber 32A in the upper portion and a liquid chamber 32B in the lower portion. The gas chamber 32A is connected to the downstream end of the communication channel pipe P5. The gas chamber 32A is also connected to the upstream end of the communication flow path pipe P6. A water delivery port 32C is formed at the bottom of the liquid chamber 32B, and a reformed gas water pipe P8B is connected to the water delivery port 32C. The steam in the reformed gas is condensed by being cooled in the heat exchanger HE2 arranged upstream of the water separator 32 after pressurization. The water separated from the reformed gas by condensation is stored in the liquid chamber 32B and sent to the reformed gas water pipe P8B. A downstream end of the communication flow pipe P6 is connected to the hydrogen purifier 16 .

A buffer tank 36 is provided downstream of the post-pressurization water separator 32 and upstream of the hydrogen purifier 16 . The buffer tank 36 accumulates the reformed gas supplied from the post-pressurization water separator 32 . The reformed gas once accumulated in the buffer tank 36 is sent to the hydrogen purifier 16 . An on-off valve V5 is provided on the downstream side of the buffer tank 36 of the communication passage pipe P6.

(hydrogen purifier)
The hydrogen purifier 16 is connected to the downstream end of a communication passage pipe P6 through which the reformed gas from the post-pressurization water separator 32 flows. A PSA device is used as an example of the hydrogen purifier 16 . The hydrogen purifier 16, as shown in FIG. 4, has two adsorption units 16A and 16B. The downstream end of the connecting flow pipe P6 and the upstream end of the offgas pipe P7 are connected to each of the two adsorption units 16A and 16B via the first switching unit 15 . Also, the upstream end of the hydrogen gas delivery pipe P11 and the downstream end of the cleaning gas pipe P12 are connected to each of the two adsorption units 16A and 16B via the second switching unit 17 . The cleaning gas pipe P12 is provided with an on-off valve V4 (see FIG. 1).

The first switching portion 15 and the adsorption portion 16A are connected via a pipe P15A, and the first switching portion 15 and the adsorption portion 16B are connected via a pipe P15B. The second switching portion 17 and the adsorption portion 16A are connected via a pipe P17A, and the second switching portion 17 and the adsorption portion 16B are connected via a pipe P17B.

The first switching section 15 and the second switching section 17 are configured including connection paths and a plurality of electromagnetic valves, and are connected to the control section 60 via signal lines. Each solenoid valve in the first switching section 15 and the second switching section 17 is controlled by the control section 60 to switch between inflow/outflow and stop of the gas to the adsorption sections 16A and 16B.

Adsorbents are accommodated in the adsorption portions 16A and 16B, and impurities are adsorbed by the adsorption portions 16A and 16B, thereby separating the reformed gas into a hydrogen-rich gas and an off-gas containing impurities. The reformed gas flows from the connection side of the pipes P15A and 15B, and is purified by adsorbing impurities before reaching the connection side of the pipes P17A and 17B. The hydrogen-rich gas that has permeated the adsorption portions 16A and 16B is delivered to a hydrogen gas delivery pipe P11 arranged on the hydrogen-rich gas outlet side of the hydrogen purifier 16 . Impurities adsorbed by the adsorption units 16A and 16B are desorbed from the adsorbent by decompressing the adsorption units 16A and 16B at a predetermined timing, and sent to an offgas pipe P7, which will be described later, arranged on the offgas outlet side. be.

As shown in FIG. 1, the hydrogen gas delivery pipe P11 is branched into three into a hydrogen supply pipe P11A, an off-gas junction pipe P11B, and a cleaning gas supply pipe for other equipment P11C.

A hydrogen purity sensor 46 is provided upstream of the three-branched portion of the hydrogen gas delivery pipe P11. The hydrogen purity sensor 46 detects the hydrogen purity of the hydrogen-rich gas delivered to the hydrogen gas delivery pipe P11. The higher the purity detected, the higher the hydrogen concentration. The hydrogen purity sensor 46 is connected to the control unit 60 via a signal line, and data regarding the detected hydrogen purity (hydrogen purity data) is sent to the control unit 60 . As the hydrogen purity sensor 46 that detects the purity of hydrogen, for example, a hydrogen purity meter that uses the principle that the resonance frequency of a thin film cylinder changes depending on the density of the surrounding gas, a sensor that optically detects the purity of hydrogen, etc. Any sensor that can detect the purity of hydrogen may be used.

The hydrogen supply pipe P11A is provided with an on-off valve V1. The on-off valve V1 is opened when the value of the hydrogen purity data D1 detected by the hydrogen purity sensor 46 is equal to or greater than the threshold value α, and product hydrogen is delivered to the hydrogen supply pipe P11A. The threshold α can be set according to the required hydrogen purity, and can be set to 99.99%, for example. Product hydrogen is stored in a tank (not shown) or sent to a hydrogen supply line.

The other device cleaning gas supply pipe P11C is connected to the other hydrogen production device 10 (if the hydrogen production device 10A, the other hydrogen production device is the hydrogen production device 10B; if the hydrogen production device 10B, the other hydrogen production device is the hydrogen production device 10A) and connected to the cleaning gas pipe P12 of another hydrogen production apparatus 10.

An on-off valve V3 is provided in the other machine cleaning gas supply pipe P11C. The on-off valve V3 is opened in the hydrogen production apparatus 10 that supplies the other-machine cleaning gas during the other-machine cleaning process, which will be described later.

In the present embodiment, the hydrogen purity sensor 46 detects the hydrogen purity of the hydrogen-rich gas delivered to the hydrogen gas delivery pipe P11, but the temperature of the reforming catalyst is detected with respect to the threshold value β, and the temperature is adjusted accordingly. hydrogen purity may be estimated. For example, it can be determined that the hydrogen purity is lower than the threshold value β when the temperature of the reforming catalyst is L1, which is lower than during operation when hydrogen is produced in rated operation.

Further, with respect to the threshold β, the pressure differential in the operation of the hydrogen purifier 16 may be detected to estimate the hydrogen purity corresponding to the pressure differential. For example, it can be determined that the hydrogen purity is lower than the threshold value β when the pressure difference is L2, which is smaller than that during operation when hydrogen is produced in rated operation. Further, the hydrogen purity may be estimated by combining the temperature of the reforming catalyst and the pressure difference.

The offgas junction pipe P11B joins with an offgas pipe P7, which will be described later. An on-off valve V2 is provided in the offgas junction pipe P11B. The on-off valve V2 is opened when the value of the hydrogen purity data D1 detected by the hydrogen purity sensor 46 is less than the threshold value α. Further, during the other machine cleaning process, which will be described later, it is opened when the value of the hydrogen purity data D1 detected by the hydrogen purity sensor 46 is less than the threshold value β.

The on-off valves V1 to V5 are connected to the control unit 60 by signal lines, and are controlled by the control unit 60 to open and close.

An upstream end of an offgas pipe P7 is connected to the offgas outlet side of the hydrogen purifier 16 . An offgas junction pipe P11B is connected to the offgas pipe P7. A downstream end of the offgas pipe P7 is connected to the burner 22 of the multiple cylinder reformer 12 . The separated off-gas is delivered from the hydrogen purifier 16 to the off-gas pipe P7. An offgas tank 18 is provided in the offgas pipe P7. The off-gas is temporarily stored in the off-gas tank 18, flows through the off-gas pipe P7, and is supplied to the burner 22 (see FIG. 2) of the multiple cylinder reformer 12 as fuel.

(Combustion exhaust gas water separator)
The combustion exhaust gas water separator 34 has a gas chamber 34A at its upper portion and a liquid chamber 34B at its lower portion. A downstream end of a gas discharge pipe P10 is connected to the gas chamber 34A. An external discharge pipe P13 is connected to the gas chamber 34A. A water delivery port 34C is formed at the bottom of the liquid chamber 34B, and a combustion exhaust gas water pipe P8C is connected to the water delivery port 34C. The flue gas water separator 34 has a larger capacity than the pre-pressurization water separator 30 and the post-pressurization water separator 32 . It is preferable that the flue gas water separator 34 has a larger capacity than the pre-pressurization water separator 30 and the post-pressurization water separator 32 by increasing the bottom area.

The flue gas is sent out from the combustion section 21 through the flue gas passage 23 to the gas discharge pipe P10. Water vapor in the flue gas is condensed by being cooled in the heat exchanger HE3 arranged upstream of the flue gas water separator 34 . The water separated from the flue gas by condensation is stored in the liquid chamber 34B and sent to the flue gas water pipe P8C. The combustion exhaust gas from which water has been separated is discharged to the outside through an external discharge pipe P13.

A water tank 40 is arranged at the bottom of the hydrogen production device 10 . A water inlet 40A is formed in the top surface of the water tank 40, and the reformed gas water pipes P8A and P8B and the flue gas water pipe P8C are connected to the water inlet 40A after joining. The pipe after joining is called a water inflow pipe P8. The water separated by the pre-pressurization water separator 30, the post-pressurization water separator 32, and the combustion exhaust gas water separator 34 flows into the water tank 40 and is stored therein.

The upstream end of the reforming water supply pipe P9 is connected to the water tank 40 . The reformed water supply pipe P9 is provided with a water treatment device (ion exchange resin) 42 for removing dissolved ion components. The reformed water supply pipe P9 is provided with a pump 44. By driving the pump 44, the water stored in the water tank 40 is supplied to the multiple cylinder reformer 12 through the water treatment device 42. be.

It should be noted that water may be supplied from the outside to the water tank 40 to make up for the shortage of reforming water.

(action)
Next, the action of the hydrogen production system 70 will be described.

First, the general flow of the hydrogen production process by each hydrogen production device 10 (10A, 10B) will be described. The city gas supplied from the raw material supply pipe P1 to the multiple cylinder reformer 12 is heated while being mixed with the reforming water in the preheating passage 24A, becomes a mixed gas, and is supplied to the reforming catalyst layer 24C. In the reforming catalyst layer 24C, the mixed gas is steam-reformed by receiving heat from the flue gas flowing through the flue gas passage 23, and a reformed gas containing hydrogen as a main component is generated. The reformed gas is supplied to the CO conversion catalyst layer 26 through the reformed gas channel 25 . In the CO conversion catalyst layer 26, carbon monoxide contained in the reformed gas reacts with water vapor to be converted into hydrogen and carbon dioxide, thereby reducing carbon monoxide. The reformed gas that has passed through the CO conversion catalyst layer 26 is supplied to the CO selective oxidation catalyst layer 27 together with the oxidizing gas (air) supplied from the oxidizing gas supply pipe P2B, and carbon monoxide reacts with oxygen on the catalyst. is converted to carbon dioxide and carbon monoxide is removed. The reformed gas whose carbon monoxide has been reduced by the CO selective oxidation catalyst layer 27 is sent to the reformed gas discharge pipe P3.

The reformed gas is supplied to the gas chamber 30A of the pre-pressurization water separation section 30 through the heat exchanger HE1 provided in the reformed gas discharge pipe P3. Water contained in the reformed gas supplied to the gas chamber 30A is condensed by cooling in the heat exchanger HE1, stored in the liquid chamber 30B, and delivered to the water tank 40 through the reformed gas water pipe P8A. From the gas chamber 30A, the reformed gas from which water has been separated flows through the communication flow pipe P4, is supplied to the compressor 14, and is compressed by the compressor 14.

The compressed reformed gas flows through the connecting flow pipe P6 and is supplied to the gas chamber 32A of the water separator 32 after being pressurized. The water vapor contained in the reformed gas supplied to the gas chamber 32A is condensed by cooling in the heat exchanger HE2, stored in the liquid chamber 32B, and delivered to the water tank 40 through the reformed gas water pipe P8B. From the gas chamber 32A, the reformed gas from which water has been separated flows through the connecting flow pipe P6 and is supplied to the hydrogen purifier 16. As shown in FIG.

In the hydrogen purifier 16, impurities are adsorbed in the adsorption units 16A and 16B, whereby the reformed gas is separated into an off-gas and a hydrogen-rich gas. 12 burners 22 are supplied. In the combustion section 21 of the multiple cylinder reformer 12, the off-gas is combusted, and the flue gas is supplied to the gas chamber 34A of the flue gas water separation section 34 through the gas discharge pipe P10. Water vapor contained in the flue gas supplied to the gas chamber 34A is condensed by cooling in the heat exchanger HE3, stored in the liquid chamber 34B, and delivered to the water tank 40 through the flue gas water pipe P8C. The combustion exhaust gas from which water has been separated is discharged to the outside through an external discharge pipe P13. The hydrogen-rich gas is delivered to the hydrogen gas delivery pipe P11.

Next, the other machine cleaning process will be described. This other machine cleaning process is performed to remove impurities remaining in the adsorption section 16A when the purity of the product hydrogen delivered from the hydrogen purifier 16 is lowered or after a predetermined period of time has elapsed. It is also performed before starting the operation of the hydrogen production device 10 and before stopping the operation. In this embodiment, the case where both the hydrogen production devices 10A and 10B are in hydrogen production operation and the hydrogen production device 10A is cleaned (the hydrogen production device 10A is the hydrogen production device to be cleaned) will be described.

When the user initiates an instruction to perform the other machine cleaning process for the hydrogen production apparatus 10A, the control unit 60 executes the other machine cleaning process shown in FIG. First, in step S10, the on-off valve V1 of the hydrogen production device 10B is closed, and the on-off valve V3 is opened. In step S12, the on-off valve V4 of the hydrogen production device 10A is opened. Then, in step S14, the first switching unit 15 and the second switching unit 17 of the hydrogen production device 10A are controlled to perform the first cleaning process. The first cleaning process is a process for cleaning the adsorption section 16A, in which cleaning gas for other machines is supplied to the adsorption section 16A, and used cleaning gas for other machines is sent from the adsorption section 16A to the offgas pipe P7. The first switching unit 15 and the second switching unit 17 are controlled so that the reformed gas is supplied to the adsorption unit 16B and the hydrogen-rich gas not adsorbed by the adsorption unit 16B is delivered from the adsorption unit 16B to the hydrogen gas delivery pipe P11. be.

As a result, the hydrogen-rich gas is supplied from the hydrogen production apparatus 10B to the adsorption unit 16A as the cleaning gas for the other machine, and the cleaning gas for the other machine passes through the adsorption section 16A and is sent to the offgas pipe P7. Note that the supply of the reformed gas to the adsorption section 16A is stopped, and the adsorption section 16A is in the same reduced pressure state as when the offgas is exhausted. Also, in the adsorption section 16B, hydrogen-rich gas is purified in the normal hydrogen purification mode.

Next, in step S16, it is determined whether or not the predetermined time T1 has elapsed. The time T1 here is set to the time required to send out the impurities remaining in the adsorption section 16A to the offgas pipe P7. If the predetermined time T1 has not elapsed, the process waits until the predetermined time T1 has elapsed.

After the predetermined time T1 has elapsed, the process proceeds to step S18, where the first switching section 15 and the second switching section 17 of the hydrogen production device 10A are controlled to perform the second cleaning process. The second cleaning process is a process for cleaning the adsorption unit 16B, in which the cleaning gas for the other machine is supplied to the adsorption unit 16B, and the used cleaning gas for the other machine is sent from the adsorption unit 16B to the offgas pipe P7. The first switching unit 15 and the second switching unit 17 are controlled so that the reformed gas is supplied to the adsorption unit 16A and the hydrogen-rich gas not adsorbed by the adsorption unit 16A is delivered from the adsorption unit 16A to the hydrogen gas delivery pipe P11. be.

As a result, the hydrogen-rich gas is supplied from the hydrogen production apparatus 10B to the adsorption section 16B as the cleaning gas for the other machine, and the cleaning gas for the other machine passes through the adsorption section 16B and is sent to the offgas pipe P7. Note that the supply of the reformed gas to the adsorption section 16B is stopped, and the reduced pressure state is the same as when the offgas is exhausted. Also, in the adsorption section 16A, hydrogen-rich gas is purified in the normal hydrogen purification mode.

Next, in step S20, it is determined whether or not a predetermined time T2 has elapsed. The time T2 here is set to the time required to send out the impurities remaining in the adsorption section 16B to the offgas pipe P7. If the predetermined time T2 has not elapsed, the process waits until the predetermined time T2 elapses.

After the predetermined time T2 has elapsed, the process proceeds to step S22 to close the on-off valve V4 of the hydrogen production device 10A, and in step S24 to close the on-off valve V3 of the hydrogen production device 10B and open the on-off valve V1. End the process. Note that the processing order of steps S22 and S24 may be reversed. The closing of the on-off valve V4 of the hydrogen production device 10A, the closing of the on-off valve V3 of the hydrogen production device 10B, and the opening of the on-off valve V1 are performed almost simultaneously.

By this other machine cleaning process, the impurities remaining in the adsorption units 16A and 16B are removed, and the amount of impurities contained in the hydrogen-rich gas delivered to the hydrogen gas delivery pipe P11 can be reduced.

In addition, since the hydrogen purifier 16 of the own device (hydrogen production device 10A) is cleaned using hydrogen-rich gas refined by another device (hydrogen production device 10B), there is no need to provide a hydrogen tank for cleaning. The hydrogen purifier 16 can be cleaned with a simple configuration.

Further, in the present embodiment, since the cleaning gas used for cleaning is sent to the offgas pipe P7, the used cleaning gas for other machines can be treated in the same manner as the offgas.

In this embodiment, the example in which the other equipment cleaning process is performed during operation of both the hydrogen production apparatuses 10A and 10B has been described, but the hydrogen production apparatus 10A may be cleaned when the hydrogen production apparatus 10B is started.

The other machine cleaning process in this case is executed by the control unit 60 when an instruction to perform the other machine cleaning process is input at the start of operation of the hydrogen production apparatus 10B. As shown in FIG. 6, first, in step S30, the hydrogen production apparatus 10B is activated to start production of hydrogen. Next, in step S32, the on-off valves V2 and V5 of the hydrogen production device 10B are opened. Thereby, hydrogen production is started in the hydrogen production apparatus 10B.

At step S34, the hydrogen purity data D1 is acquired from the hydrogen purity sensor 46, and at step S36, it is determined whether or not the hydrogen purity data D1 is equal to or greater than the threshold value β. If the hydrogen purity data D1 is less than the threshold value β, the process waits until the hydrogen purity data D1 becomes equal to or greater than the threshold value β. The on-off valve V2 of the device 10B is closed and the on-off valve V3 is opened.

Next, in step S40, a cleaning process is performed. This cleaning process is the same as the process from step S12 to step S22 shown in FIG.

As a result, the hydrogen-rich gas separated by the hydrogen purifier 16 of the hydrogen production device 10B passes through the hydrogen gas delivery pipe P11, the cleaning gas supply pipe P11C for other equipment, and the cleaning gas pipe P12, and then the hydrogen purifier 16 of the hydrogen production device 10A. supplied to This hydrogen-rich gas is usually low-purity hydrogen gas because the hydrogen production apparatus 10B has just started up.

In the hydrogen purifier 16 of the hydrogen production device 10A, the supplied low-purity hydrogen gas sequentially cleans the adsorption portions 16A and 16B. During the process, the gas separated as off-gas is delivered to the off-gas tank 18 in the hydrogen generator 10A or the low-purity hydrogen tank 50 of the hydrogen generator 10A depending on the hydrogen purity. As a result, impurities remaining in the adsorption sections 16A and 16B of the hydrogen production device 10A are removed.

Next, in step S42, the on-off valve V3 of the hydrogen production device 10B is closed, the on-off valve V1 is opened, and the process ends.

In this other machine cleaning process as well, impurities remaining in the adsorption units 16A and 16B of the hydrogen purifier 16 are removed, and the amount of impurities contained in the hydrogen-rich gas delivered to the hydrogen gas delivery pipe P11 in the hydrogen production device 10A is can be reduced.

Note that the threshold value β related to the hydrogen purity of the hydrogen-rich gas used for cleaning is set as the hydrogen purity that can be used for cleaning the hydrogen purifier 16, and can be set within the range of 77% to 99.99%. Note that the threshold value β is preferably 99.5% or more in order to perform cleaning more effectively and lengthen the cleaning interval. In the summer when the outside air temperature is high, the temperature inside the hydrogen purifier 16 rises and the adsorption performance of the adsorption sections 16A and 16B tends to decrease. Therefore, the threshold value β may be changed according to the outside air temperature. That is, when the outside temperature is high, the threshold β may be set relatively high, and when the outside temperature is low, the threshold β may be set relatively low.

In addition, in the present embodiment, the case of having a plurality of hydrogen production apparatuses having the same configuration has been described, but each hydrogen production apparatus may have a different configuration as long as it has a reformer and a hydrogen purifier. may

Further, in the present embodiment, the cleaning gas supply pipe P11C for other equipment extends to another hydrogen production device 10 and is connected to the cleaning gas pipe P12 of the other hydrogen production device 10. The connection with the manufacturing apparatus 10 may have other configurations. For example, as in the hydrogen production system 70A shown in FIG. 7, when there are three or more hydrogen production devices 10 (hydrogen production devices 10A, 10B, and 10C), the other devices are connected to each other by a common pipe P18. you can go In this case, the other equipment cleaning gas supply pipe P11C and the cleaning gas pipe P12 in each hydrogen production device 10 are connected to the common pipe P18.

10, 10A, 10B Hydrogen production device 12 Multi-cylinder reformer (reformer)
15 first switching unit (cleaning execution unit)
17 second switching unit (cleaning execution unit)
16 hydrogen purifiers 16A, 16B adsorption unit 60 control unit (cleaning execution unit)
70 Hydrogen production system P7 off-gas pipe (off-gas delivery path)
P11 hydrogen gas delivery pipe (hydrogen gas delivery path)
P11C Other machine cleaning gas supply pipe (other machine cleaning gas supply path)

Claims (9)

an off-gas delivery path for separating the reformed gas from a reformer that reforms a raw material to produce a reformed gas containing hydrogen as a main component into a hydrogen-rich gas and an off-gas containing impurities and delivering the off-gas; a plurality of hydrogen production apparatuses each having a hydrogen purifier having a hydrogen gas delivery path for delivering hydrogen-rich gas;
a cleaning gas supply path branched from the hydrogen gas delivery path and supplying the hydrogen-rich gas to the hydrogen purifier of another hydrogen production apparatus;
Hydrogen production system with Each of the hydrogen purifiers of the plurality of hydrogen production devices has an adsorption unit that adsorbs the impurities,
stopping the flow of the reformed gas into the adsorption unit of the hydrogen producing device to be cleaned among the plurality of hydrogen producing devices, and the hydrogen producing device to be cleaned among the plurality of hydrogen producing devices; The hydrogen-rich gas is supplied from a different hydrogen production apparatus to the adsorption unit of the hydrogen production apparatus to be cleaned through the other apparatus cleaning gas supply path as the other apparatus cleaning gas to perform cleaning of the adsorption unit. part,
The hydrogen production system according to claim 1, comprising: 3. The hydrogen production system according to claim 2, wherein said cleaning execution unit delivers said hydrogen-rich gas after being used in said cleaning process from said hydrogen purifier of said hydrogen production apparatus to be cleaned to said offgas delivery path. When the hydrogen purity of the hydrogen-rich gas in the hydrogen gas delivery path of the other hydrogen production apparatus is equal to or higher than the cleaning purity lower than the threshold value of the hydrogen purity of the product , the cleaning execution unit converts the hydrogen-rich gas into the hydrogen to be cleaned. 4. The hydrogen production system according to claim 2, wherein the gas is supplied to the hydrogen purifier of the hydrogen production device to be cleaned as a cleaning gas for cleaning the production device. In some of the plurality of hydrogen production apparatuses, a reformed gas mainly composed of hydrogen supplied from a reformer is separated into a hydrogen-rich gas and an off-gas containing impurities by a hydrogen purifier, delivering the off-gas to the off-gas delivery path and delivering the hydrogen-rich gas to the hydrogen gas delivery path;
The hydrogen-rich gas delivered from the hydrogen gas delivery path of the one of the hydrogen production devices is used as a cleaning gas for another hydrogen production device to be cleaned among the plurality of hydrogen production devices. A method for cleaning a hydrogen production device, which comprises supplying a hydrogen purifier of the hydrogen production device to perform cleaning treatment. Each of the hydrogen purifiers of the plurality of hydrogen production devices has an adsorption unit that adsorbs the impurities,
In the cleaning process, the reformed gas is stopped from flowing into the adsorption unit of the hydrogen production device to be cleaned, and the adsorption part of the hydrogen production device to be cleaned is removed from another hydrogen production device different from the hydrogen production device to be cleaned. 6. The method for cleaning a hydrogen production apparatus according to claim 5, wherein the hydrogen-rich gas is supplied to the unit as a cleaning gas for other equipment. 7. The method for cleaning a hydrogen production apparatus according to claim 5, wherein the hydrogen-rich gas after being used in the cleaning process is delivered from the hydrogen purifier of the hydrogen production apparatus to be cleaned to the offgas delivery path. . When the hydrogen purity of the hydrogen-rich gas in the hydrogen gas delivery path of another hydrogen production device different from the hydrogen production device to be cleaned is equal to or higher than the cleaning purity lower than the threshold value of the product hydrogen purity , the hydrogen-rich gas is removed from the to-be-cleaned hydrogen production device. 8. The method for cleaning a hydrogen production device according to claim 5, wherein the gas is supplied to the hydrogen purifier of the hydrogen production device to be cleaned as a cleaning gas for cleaning the hydrogen production device. A hydrogen production apparatus control program for causing a computer to function as each part of the hydrogen production apparatus according to any one of claims 1 to 4.

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