JP2005206457A - Hydrogen generator, and fuel cell system using hydrogen generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inhibit the deterioration of characteristics of a carbon monoxide reduction catalyst caused by condensed water which arises from water vapor retained in a hydrogen generator when the operation of the hydrogen generator is stopped. <P>SOLUTION: The hydrogen generator is provided with a reforming part 101 having a reforming catalyst to generate a hydrogen-rich reformed gas by reacting a raw material with water, a heating part 104 of the reforming part to heat the reforming part, carbon monoxide reduction parts 111 and 121 each having the carbon monoxide reduction catalyst which reduces carbon monoxide in the reformed gas, carbon monoxide reduction heating parts 112 and 123 which heat at least any one of the carbon monoxide reduction parts, the carbon monoxide reduction catalysts, and the reformed gas passing through the carbon monoxide reduction parts, and a controlling section 200 which puts the carbon monoxide reduction heating parts into operation. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a hydrogen generator for generating hydrogen to be supplied to a fuel cell, and a fuel cell system using the hydrogen generator. More specifically, the present invention relates to a hydrogen generator that performs heating so that water vapor does not condense in the carbon monoxide reduction unit during a shutdown operation, and a fuel cell system using the hydrogen generator.

  A fuel cell cogeneration system with high power generation efficiency and high overall efficiency has attracted attention as a distributed power generator that effectively uses energy.

  Many fuel cells, for example, phosphoric acid fuel cells that have been put into practical use and solid polymer fuel cells (hereinafter referred to as PEFC) that are being developed, generate electricity using hydrogen as fuel. However, since hydrogen is not provided as infrastructure, it must be generated at the site where the system is installed.

  One of the hydrogen generation methods is a steam reforming method. In the steam reforming method, natural gas, LPG, naphtha, gasoline, kerosene and other hydrocarbon-based materials such as methanol are mixed with water, and a steam reforming reaction is performed in a reforming section provided with a reforming catalyst. And generating hydrogen.

  In this steam reforming reaction, carbon monoxide (hereinafter referred to as CO) is generated as a subcomponent, and about 10 to 15% of CO is contained in the reformed gas after the reforming section. The CO contained in the reformed gas poisons the electrode catalyst of the polymer electrolyte fuel cell and lowers the power generation capacity. Therefore, a CO reduction unit is provided and the CO concentration in the reformed gas at the hydrogen generator outlet Must be removed to 100 ppm or less, preferably 10 ppm or less.

  In general, the CO reduction unit of the hydrogen generator includes a shift reaction unit having a shift reaction catalyst that causes a water gas shift reaction in which CO and steam react to generate hydrogen and carbon dioxide, and oxygen in the air by supplying air. And a CO removal section having at least one of a selective oxidation catalyst for selectively oxidizing CO and a methanation catalyst for removing CO by methanation, thereby connecting the CO concentration in the reformed gas to 10 ppm or less. To remove.

  By the way, it is necessary to start and stop PEFC according to the demand for electric power in order to improve energy utilization efficiency. In response to this, it is necessary to start and stop the hydrogen generator.

A method has been proposed in which the combustible gas remaining in the hydrogen generator is purged using water vapor in consideration of safety and durability of the reforming catalyst when the hydrogen generator is stopped (see, for example, Patent Document 1). ).
JP 2002-93447 A

  When stopping the hydrogen generator to stop the PEFC that was generating electricity, the temperature of each part is usually high, so even if purging with steam, the steam is purged with air or source gas and then hydrogen If discharged outside the generator, water will not condense inside the hydrogen generator.

On the other hand, when the hydrogen generator is started, raw material and water are supplied from the raw material supply unit and the water supply unit to the reforming unit, respectively, and the reforming unit is heated by the reforming unit heating unit. The reformed gas that has passed through the shift reaction section and the CO removal section conducts heat to raise the temperature of the shift reaction section and the CO removal section.

  For this reason, it takes time to raise the temperature of the shift reaction unit and the CO removal unit. In one example, when the temperatures of the shift reaction unit and the CO removal unit were detected, it took 30 to 40 minutes for the temperature to exceed 100 ° C., depending on the size and configuration of the apparatus.

  As described above, especially when the hydrogen generator has to be stopped for some reason during the start-up, the CO reduction unit in the downstream portion of the hydrogen generator is often in a state close to normal temperature. If purging with water vapor at that time, water may condense in the CO reduction part and may condense on the CO reduction catalyst housed in the CO reduction part. Condensation of water on the CO-reducing catalyst has a problem in that the characteristics of the CO-reducing catalyst are deteriorated.

  Moreover, although there exist some which used heating means, such as a heater, in the hydrogen production | generation apparatus, it was used only for heating a catalyst at the time of starting, and the catalyst was not heated at the time of a stop. Therefore, when the operation is stopped immediately after startup, the temperature of the CO reduction unit is not sufficiently increased, so that water contained in the purge gas may condense and cause deterioration of the catalyst. It was.

  In view of the above-described conventional problems, an object of the present invention is to provide a hydrogen generator that does not condense water in the CO reduction unit when stopped, and a fuel cell system using the same.

  In order to achieve the above object, a first aspect of the present invention provides a reforming unit having a reforming catalyst that generates a hydrogen-rich reformed gas by reacting a raw material with water, and for heating the reforming unit. A reforming section heating section, a carbon monoxide reduction section having a carbon monoxide reduction catalyst for reducing carbon monoxide in the reformed gas, the carbon monoxide reduction section, the carbon monoxide reduction catalyst, and the one A carbon monoxide reduction heating unit for heating at least one of the reformed gas that passes through the carbon oxide reduction unit, and a control unit, at the time of shutdown operation, by the control of the control unit, In the hydrogen generating apparatus, the carbon monoxide reduction heating unit is operated so as to be equal to or higher than a first predetermined temperature at which water vapor in the carbon monoxide reduction unit is not condensed.

  In the second aspect of the present invention, the carbon monoxide reduction unit is a shift reaction unit and a CO removal unit, and the carbon monoxide reduction heating unit is a shift reaction unit heating unit and a CO removal unit heating unit, The carbon monoxide reduction catalyst of the shift reaction unit is a shift reaction catalyst, and the carbon monoxide reduction catalyst of the CO removal unit includes at least one of a selective oxidation catalyst and a methanation catalyst. This is a hydrogen generator.

  The third aspect of the present invention further includes a carbon monoxide reduction unit temperature detection unit that detects a temperature of the carbon monoxide reduction unit, and the temperature of the carbon monoxide reduction unit is at least the first when the operation is stopped. The hydrogen generating device according to the first aspect of the present invention operates the carbon monoxide reduction heating unit under the control of the control unit while the temperature is below the predetermined temperature.

  The fourth aspect of the present invention is the hydrogen generator according to the first aspect of the present invention, wherein the carbon monoxide reduction heating unit is operated by the control of the control unit based on a stop command during the operation stop operation.

  The fifth aspect of the present invention is the hydrogen generator according to the fourth aspect of the present invention, wherein the operation of the carbon monoxide reduction heating unit is stopped under the control of the control unit after a predetermined time has elapsed since the stop command was issued. is there.

  In addition, the sixth aspect of the present invention includes a reforming unit temperature detection unit that detects the temperature of the reforming unit, and stops the supply of raw materials and water by the control of the control unit during the operation stop operation. When the temperature detected by the reforming unit temperature detection unit reaches a temperature at which no carbon is deposited on the reforming catalyst, the control unit controls the control unit to operate the carbon monoxide reduction heating unit. The raw material is supplied by control to purge the inside of the hydrogen generator, and then the supply of the raw material and the operation of the carbon monoxide reduction heating unit are stopped by the control of the control unit. It is the hydrogen generator of the invention.

  A seventh aspect of the present invention is a first purge gas supply unit for supplying a first purge gas, a second purge gas supply unit for supplying a second purge gas, A reforming unit temperature detection unit that detects the temperature of the reforming unit, and when the temperature detected by the reforming unit temperature detection unit is equal to or lower than a second predetermined temperature at the time of the shutdown operation, The second supply unit is operated under the control of the control unit until the hydrogen generation device is filled with the second purge gas, and the temperature detected by the reforming unit temperature detection unit is a second value. When the temperature is not lower than a predetermined temperature, the first purge gas supply unit is operated by the control of the control unit, and the temperature detected by the reforming unit temperature detection unit becomes equal to or lower than the second predetermined temperature. The second purge gas supply unit is controlled by the control unit. The hydrogen generator is operating to be filled with the second purge gas is any hydrogen generator of the present invention the first to 5.

  According to an eighth aspect of the present invention, the first purge gas is water vapor, the second purge gas is air, and the second predetermined temperature does not oxidize the reforming catalyst. It is a hydrogen generator of the 7th present invention which is temperature.

  According to a ninth aspect of the present invention, the first purge gas is water vapor, the second purge gas is a raw material, and the second predetermined temperature is defined as carbon on the reforming catalyst. This is the hydrogen generator of the seventh aspect of the present invention at a temperature at which no precipitation occurs.

  A tenth aspect of the present invention is the hydrogen generator according to the seventh aspect of the present invention, wherein the first purge gas is either a combustion exhaust gas or an inert gas.

  An eleventh aspect of the present invention is a fuel cell system comprising the hydrogen generator according to any one of the first to tenth aspects of the present invention, and a fuel cell that generates power using the hydrogen generated by the hydrogen generator. It is.

  According to the present invention, it is possible to provide a hydrogen generator that does not condense water in the CO reduction section when stopped, and a fuel cell system using the same.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Embodiment 1)
FIG. 1 is a configuration diagram of the hydrogen generation apparatus according to the first embodiment.

  As shown in FIG. 1, the hydrogen generator 1 of Embodiment 1 includes a reforming unit 101 having a reforming catalyst that generates a hydrogen-rich gas from a hydrocarbon-based material and water, and a raw material in the reforming unit 101. A raw material supply unit 102 for supplying water and a water supply unit 103 for supplying water to the reforming unit 101 are provided.

  The reforming unit 101 is provided with a reforming unit heating unit 104 that heats the reforming unit 101 and a reforming unit temperature detection unit 105 that detects the temperature of the reforming unit 101. The supplied raw material and water are heated in the reforming unit 101 by the reforming unit heating unit 104 to generate a reformed gas. The amount of heating by the reforming unit heating unit 104 is determined by the temperature of the reforming catalyst detected by the reforming unit temperature detection unit 105.

  The reforming unit temperature detecting unit 105 may be configured to detect the temperature of the reformed gas after passing through the reforming catalyst. Moreover, the raw material supplied from the raw material supply unit 102 only needs to contain a compound composed of at least carbon and hydrogen, and examples thereof include hydrocarbon raw materials such as natural gas, LPG, naphtha, gasoline, kerosene, methanol, and the like. Alcohol raw materials such as

  In addition, a shift reaction catalyst (not shown) for reducing CO in the reformed gas supplied from the reforming unit 101 by a water gas shift reaction is provided downstream of the reforming unit 101 with reference to the raw material supply direction. The shift reaction part 111 which has is installed. The shift reaction unit 111 includes a shift reaction unit 111, a shift reaction catalyst, a shift reaction unit heating unit 112 for heating the reformed gas, and a temperature for detecting the temperature of the reformed gas flowing in the shift reaction unit 111. A shift reaction unit temperature detection unit 113 is provided. The shift reaction unit 111 is an example of the carbon monoxide reduction unit of the present invention. The shift reaction catalyst is an example of the carbon monoxide reduction catalyst of the present invention. The shift reaction part heating part 112 is an example of the carbon monoxide reduction heating part of the present invention. The shift reaction part temperature detection part 113 is an example of the carbon monoxide reduction part temperature detection part of this invention.

In the first embodiment, an electric heater is used as the shift reaction unit heating unit 112 and is attached to the outside of the shift reaction unit 111. Moreover, the shift reaction part heating part 112 should just be what can heat the shift reaction part 111, such as not only an electric heater but a burner and a catalytic combustion system. Note that the shift reaction unit temperature detection unit 113 may detect the temperature of the shift reaction catalyst.

  Further, a CO removal unit 121 having a CO removal catalyst for further reducing CO in the reformed gas after passing through the shift reaction unit 111 is installed on the downstream side of the shift reaction unit 111. The CO removal unit 121 includes a CO removal unit heating unit 123 that heats at least one of the CO removal unit 121, the CO removal catalyst, and the reformed gas, and a reformed gas that flows through the CO removal unit 121. A CO removal unit temperature detection unit 124 for detecting the temperature is installed. An air supply unit 122 for supplying air is installed between the CO removal unit 121 and the shift reaction unit 111. In the CO removal unit, oxygen in the air supplied from the air supply unit 122 and CO in the reformed gas are reduced by a selective oxidation reaction. The CO removing unit 121 is an example of the carbon monoxide reducing unit of the present invention. The CO removal catalyst is an example of the carbon monoxide reduction catalyst of the present invention. The CO removal unit heating unit 123 is an example of the carbon monoxide reduction heating unit of the present invention. The CO removal unit temperature detection unit 124 is an example of a carbon monoxide reduction unit temperature detection unit of the present invention.

  The CO removal catalyst may be a catalyst that reduces CO in the reformed gas by a methanation reaction. Further, a catalyst for promoting the selective oxidation reaction and a catalyst for promoting the methanation reaction may be used in combination. That is, the CO removal catalyst may include one or both of a selective oxidation catalyst that catalyzes a selective oxidation reaction, a methanation catalyst that catalyzes a methanation reaction, or both. In the first embodiment, an electric heater is used as the CO removal unit heating unit 123 and is attached to the outside of the CO removal unit 121. Note that the CO removal unit heating unit 123 is not limited to an electric heater, and any unit that can heat the CO removal unit 121 such as a burner or a catalytic combustion method may be used. The CO removal unit temperature detection unit 124 may detect the temperature of the CO removal catalyst.

  Further, the hydrogen generator 1 of the first embodiment includes a purge air supply unit 106 for supplying air when the hydrogen generator 1 is stopped on the upstream side of the reforming unit 101.

  In addition, the solid line in the figure indicates the relationship in which the raw material, water, air, and hydrogen-rich gas are sent between each element, and the solid line arrow indicates the direction in which the raw material, water, air, and hydrogen-rich gas are sent. Indicates.

  In addition, during the stop operation of the hydrogen generation operation 1, the amount of heating of the shift reaction unit heating unit 112 and the CO removal unit heating unit 123 is controlled, and the control for controlling the operation of each component such as the stop of the raw material supply unit 102 is performed. Part 200 is installed. The control unit 200 controls the raw material supply unit 102, the water supply unit 103, the purge air supply unit 106, the reforming unit heating unit 104, the shift reaction unit heating unit 112, the CO removal unit heating unit 123, and the air supply unit 122. Connected to control. Further, the control unit 200 is connected to receive signals sent from the reforming unit temperature detection unit 105, the shift reaction unit temperature detection unit 113, and the CO removal unit temperature detection unit 124. In addition, the dotted line in a figure shows the connection relationship in which a signal is transmitted / received between control parts, and a dotted line arrow shows the direction where a signal is sent.

  The carbon monoxide reduction unit of the present invention is configured by the shift reaction unit 111 and the CO removal unit 121 in the first embodiment, but when the CO concentration may be equal to or lower than the predetermined concentration, one of the carbon monoxide reduction units is adjusted to the predetermined concentration. You may comprise only.

  Next, the control unit 200 will be described. FIG. 8 is a wiring diagram illustrating a schematic configuration of the control device 200. The control device 200 includes an I / O input port 201, a CPU 202, a storage device 203, an I / O output port 204, a bus 205, an input device 206, and an output device 207. The I / O input port 201, the CPU 202, the storage device 203, and the I / O output port 204 are connected to each other via a bus 205. The input device 206 is connected to the I / O input port 201. The output device 207 is connected to the I / O output port 204. The I / O input port 201 is also connected to a detection device that detects a controlled amount, that is, a reforming unit temperature detection unit 105, a shift reaction unit temperature detection unit 113, and a CO removal unit temperature detection unit 124. The I / O output port 204 includes control targets, that is, a raw material supply unit 102, a water supply unit 103, a reforming unit heating unit 104, a purge air supply unit 106, a shift reaction unit heating unit 112, an air supply unit 122, A CO removal unit heating unit 123 is also connected.

  In this embodiment, a keyboard or the like is used as the input device 206, and a display or the like is used as the output device 207.

  Next, the operation of the control device 200 will be described with reference to FIG. A set value such as a hydrogen generation amount is input by the input device 206 and sent to the CPU 202 via the I / O input port 201. The CPU 202 stores such information in the storage device 203 as necessary. A signal indicating the detected value of the controlled amount detected by each detection device is sent to the CPU 202 via the I / O input port 201. The CPU 202 stores the detected values in the storage device 203 as necessary. The control program is stored in advance in the storage device 203. The CPU 202 calculates a control target value and the like to be controlled using a detection value and a control program stored in the storage device 203. Further, the CPU 202 rewrites the control target value and the like stored in the storage device 203 if necessary from the calculation result. Further, if necessary, the CPU 202 transmits a signal indicating the operation amount to the control target via the I / O output port 204 to the control target. The control target value, detection value, control program, etc. stored in the storage device 203 are output by the output device 207 via the I / O output port 204 and confirmed. With the operation as described above, the control device 200 detects and controls the value of the controlled amount, and the hydrogen generator 1 is operated.

  Here, the reformed gas containing hydrogen whose CO is reduced by the hydrogen generator 1 in the first embodiment is supplied to the PEFC (not shown) and reacted with the oxidant containing oxygen supplied to the PEFC. To generate electricity.

  The operation of the hydrogen generator 1 of the first embodiment having the above configuration will be described based on an example.

  During the operation of the hydrogen generator 1, the raw material is supplied from the raw material supply unit 102 and the water is supplied from the water supply unit 103 to the reforming catalyst stored in the reforming unit 101. Then, the reforming section heating section 104 is heated so that the temperature detected by the reforming section temperature detection section 105 is 650 ° C., and the steam reforming reaction proceeds. The CO concentration in the reformed gas after passing through the reforming unit 101 is about 10%.

  The reformed gas after passing through the reforming unit 101 is supplied to the reformed gas shift reaction unit 111 in order to reduce CO in the reformed gas. The CO in the reformed gas is reduced as the water gas shift reaction proceeds by the shift reaction catalyst stored in the shift reaction unit 111. The CO concentration in the reformed gas after passing through the shift reaction unit 111 is about 0.3%.

Further, in order to reduce CO in the reformed gas, air is supplied from the air supply unit 122 to the reformed gas that has passed through the shift reaction unit 111 and mixed, and then supplied to the CO removal unit 121. The CO concentration in the reformed gas is reduced to 100 ppm or less by the selective oxidation reaction by the CO removal catalyst housed in the CO removal unit 121. The reformed gas with reduced CO concentration is supplied to the PEFC to generate power.

  An example of the control program at the time of the operation stop operation of the hydrogen generator 1 according to Embodiment 1 will be described with reference to the flowchart of FIG. The operation stop includes not only the end of the operation but also the operation in every case of stopping the production of hydrogen such as interruption. The operation stop operation time refers to the time during which a series of operations are performed from when a stop command is issued until the hydrogen generator is stopped.

  First, the reforming unit heating unit 104 is stopped by the control unit 200 in step S1.

  Next, in step S2, the temperature detected by the shift reaction unit temperature detection unit 113 or the temperature detected by the CO removal unit temperature detection unit 124 is 100 ° C. or less, which is an example of the first predetermined temperature of the present invention. Is determined by the control unit 200.

  Here, the first predetermined temperature is a dew point of water vapor inside the shift reaction unit 111 and the CO removal unit 121. During the shutdown operation, the internal atmospheric pressure is higher than atmospheric pressure, and when purging with water vapor, the internal water vapor partial pressure is approximately 100%, but the internal dew point is approximately 100 ° C. Therefore, hereinafter, in this specification, the first predetermined temperature is assumed to be 100 ° C. However, depending on the internal pressure or the partial pressure of water vapor, the dew point may not always be 100 ° C. Therefore, the first predetermined temperature is not limited to 100 ° C., and may be any temperature as long as the water vapor does not condense in the shift reaction unit 111 and the CO removal unit 121 (that is, a temperature higher than the dew point).

  Next, when the temperature is 100 ° C. or lower, in step S3, the control unit 200 operates the shift reaction unit heating unit 112 and the CO removal unit heating unit 123 to start heating the shift reaction unit 111 and the CO removal unit 121. At this time, the control unit 200 controls heating so that the temperatures detected by the shift reaction unit temperature detection unit 113 and the CO removal unit temperature detection unit 124 are higher than 100 ° C. By this heating, the water vapor supplied later is not condensed on the shift reaction catalyst and the CO removal catalyst, and is discharged out of the hydrogen generator 1.

  Next, in step S4, the control unit 200 determines whether or not the temperature detected by the reforming unit temperature detection unit 105 is 200 ° C. or more, which is an example of the second predetermined temperature of the present invention. This determination is made because if the air is supplied when the temperature of the reforming unit 101 is 200 ° C. or higher, the reforming catalyst is oxidized and deteriorated.

  If it is 200 ° C. or higher in step S4, the raw material supply unit 102 is stopped by the control unit 200 in step S5. By stopping the raw material supply unit 102 and continuing the supply of water from the water supply unit 103, the supplied water is water vapor that is an example of the first purge gas of the present invention in the reforming unit 101. It becomes. In the present embodiment, the water supply unit 103 serves as the first purge gas supply unit of the present invention. Then, the gas passes through the shift reaction unit 111 and the CO removal unit 121 and is discharged while purging the combustible gas mainly composed of hydrogen remaining in the hydrogen generator 1.

  Next, in step S <b> 6, the control unit 200 performs detection until the temperature detected by the reforming unit temperature detection unit 105 is less than 200 ° C.

  Next, after the temperature in the reforming unit 101 becomes less than 200 ° C., the operation of the water supply unit 103 is stopped by the control unit 200 in step S7, whereby the water vapor supply is stopped.

  Next, in step S8, the control unit 200 starts the operation of the purge air supply unit 106 and operates it for a predetermined time, so that the air is purged from the hydrogen generator 1 while purging the remaining water vapor in the hydrogen generator 1. Is discharged. That is, in the present embodiment, air becomes the second purge gas of the present invention. Further, the purge air supply unit 106 is the second purge gas supply unit of the present invention. Here, the predetermined time is a time sufficient to expel water vapor from the hydrogen generator 1, but when the shift reaction unit 111 and the CO removal unit 121 are not higher than 100 ° C. by step S8. Even if the air purge operation in step S8 is performed, it is necessary to perform the air purge for a predetermined time after the temperature becomes higher than 100 ° C. If the water vapor purge is performed when the temperature is not higher than 100 ° C, the water vapor may be condensed. However, after the temperature is higher than 100 ° C, the condensed water can be evaporated and discharged by purging the air for a predetermined time. is there.

  Next, after the inside of the hydrogen generator 1 is completely purged with air, the shift reaction unit heating unit 112 and the CO removal unit heating unit 123 are stopped by the control unit 200 in step S9.

  Finally, in step S10, the air supply from the purge air supply unit 106 is also stopped, and the hydrogen generator 1 stop operation ends.

  On the other hand, if the temperatures detected by the shift reaction unit temperature detection unit 113 and the CO removal unit temperature detection unit 124 are not both 100 ° C. or lower in step S2, the condensation of water vapor does not occur even if heating is not performed. Therefore, the shift reaction unit heating unit 112 and the CO removal unit heating unit 123 are not operated, and the process proceeds to step S14.

  Next, in step S14, the control unit 200 determines whether or not the temperature in the reforming unit 101 is 200 ° C. or higher (same as step S4 above).

  Next, in step S15, the raw material supply unit 102 is stopped (same as step S5 above).

  Next, detection is performed until the temperature detected by the reforming unit temperature detection unit 105 is less than 200 ° C. in step S16 (same as step S6 above).

  After the temperature in the reforming unit 101 becomes less than 200 ° C., the operation of the water supply unit 103 is stopped in step 17 (same as step S7).

  Next, in step 18, the operation of the purge air supply unit 106 is started, and the operation is continued for a predetermined time, whereby the inside of the hydrogen generator 1 is completely purged with air (same as step S8 above). .

  Finally, in step S10, the supply of air from the purge air supply unit 106 is stopped.

  On the other hand, in step S4 and step S14, when the temperature reformed by the reforming unit temperature detecting unit 105 is not 200 ° C. or higher, purging in the hydrogen generator 1 with water vapor (first purging gas) is performed. Even if purging with air (second purge gas) is performed, the reforming catalyst is not oxidized. Therefore, when the temperature in the reforming unit 101 is not 200 ° C. or higher, the raw material supply unit 102 and the water supply unit 103 are stopped (step S11) from step S4, and the process proceeds to step S8 for further air supply. . In step S14, the raw material supply unit 102 and the water supply unit 103 are stopped (step S12), and the process further proceeds to step S18.

  As described above, the shift reaction unit 111 and the CO removal unit 121 can be held at a temperature higher than 100 ° C. by performing a stop operation that activates the shift reaction unit heating unit 112 and the CO removal unit heating unit 123. For this reason, the water vapor at the time of purging does not condense in the shift reaction unit 111 and the CO removal unit 121, and the water vapor does not remain in the shift reaction unit 111 and the CO removal unit 121 to condense. It is possible to prevent a decrease in catalyst characteristics.

  The stop operation as described above is not limited to the unsteady state immediately after the hydrogen generator 1 starts to start, but may correspond to the operation in the steady state.

  In steps S2 and S3, both of the heating are performed when the temperature in the shift reaction unit 111 or the CO removing unit 121 is 100 ° C. or lower. Good.

  Further, in steps S2, S4, and S14, the next step differs depending on the determination result, but the operations in steps S1 to S10 may always be performed without providing the determination in steps S2, S4, and S14. However, if air supply is performed at an internal temperature of the reforming unit 101 of 200 ° C. or higher, the reforming catalyst may be oxidized and deteriorated. Therefore, it is preferable to perform the determination in step S6.

  In addition, the shift reaction unit heating unit 112 and the CO removal unit heating unit 123 are stopped in step S9. However, the shift reaction unit temperature detection unit 113 and the CO removal unit temperature detection unit 124 are not limited to step S9. 111 and the temperature in the CO removing unit 121 may be monitored, and control may be performed so as to operate when the temperature is 100 ° C. or lower and to stop when the temperature is not lower than 100 ° C.

  If the temperature in the shift reaction unit 111 or the CO removal unit 121 is not 100 ° C. or lower in step S2, the shift reaction unit heating unit 112 and the CO removal unit heating unit 123 are not operated, and the process from step S14 to step S18 is performed. Although the operation is performed, the temperature may be monitored and the shift reaction unit heating unit 112 and the CO removal unit heating unit 123 may be heated when the temperature becomes 100 ° C. or lower.

  The determination of whether or not the shift reaction unit 111 and the CO removal unit 121 are 100 ° C. or less (step S2) and the operation of the shift reaction unit heating unit 112 and the CO removal unit heating unit 123 (step S3) are for purging. The operation may be performed immediately before the operation of the air supply unit 106 is started (step S8). Alternatively, the purging air supply unit 106 may be operated to purge the inside of the hydrogen generator 1 with air. In any case, if the temperature of the shift reaction unit 111 and the CO removal unit 121 is adjusted so that the condensed water does not remain in the shift reaction unit 111 and the CO removal unit 121 at the end of the purge, the shift reaction unit heating is performed. The unit 112 and the CO removal unit heating unit 123 may be operated at any timing.

  In this embodiment, the shift reaction unit temperature detection unit 113 and the CO removal unit temperature detection unit 124 monitor the temperatures in the shift reaction unit 111 and the CO removal unit 121. However, whether or not to operate the shift reaction unit heating unit 112 and the CO removal unit heating unit 123 may be determined using a physical quantity related to the temperature in the shift reaction unit 111 and the CO removal unit 121. Specifically, for example, the temperature of the reforming unit 101 detected by the reforming unit temperature detection unit 105, the time elapsed since startup, the amount of water supplied to the reforming unit 101, the shift reaction unit 111, and It may be determined whether the shift reaction unit heating unit 112 and the CO removal unit heating unit 123 are to be operated by detecting the humidity or the like in the CO removal unit 121 and using the result.

Further, the hydrogen generator 1 according to the present embodiment does not necessarily need to be used for fuel supply to the PEFC, but is a chemical plant that requires the effects of supplying fuel to other fuel cells and synthesizing high-purity hydrogen. Etc.
(Embodiment 2)
FIG. 3 is a configuration diagram of the hydrogen generator 1 according to the second embodiment. The second embodiment is different from the first embodiment in that the shift reaction unit 111 and the CO removal unit 121 are not provided with a temperature detection unit, and the shift reaction is performed regardless of the temperature of the shift reaction unit 111 and the CO removal unit 121. Operating the part heating unit 112 and the CO removing unit heating unit 123. That is, the shift reaction unit 111 and the CO removal unit 121 are always heated without performing the determination based on the temperature during the shutdown operation. In FIG. 3, the same components as those in FIG.

  Below, an example of the control program at the time of the shutdown operation of the hydrogen generator 1 will be described with reference to FIG. The operation stop includes not only the end of the operation but also the operation in every case of stopping the production of hydrogen such as interruption. The operation stop operation time refers to the time during which a series of operations are performed from when a stop command is issued until the hydrogen generator is stopped. The difference from the first embodiment of the operation stopping method according to the second embodiment is that there is no determination step in step S2 (whether the shift reaction unit 111 or the CO removal unit 121 is 100 ° C. or less) and a step branching therefrom. Is a point.

  First, the reforming unit heating unit 104 is stopped by the control unit 200 in step S21.

  Next, in step S <b> 22, the control unit 200 operates the shift reaction unit heating unit 112 and the CO removal unit heating unit 123 to start heating the shift reaction unit 111 and the CO removal unit 121. By this heating, the water vapor supplied later is not condensed on the shift reaction catalyst and the CO removal catalyst, and is discharged out of the hydrogen generator 1. Note that the capacity, heating time and intensity of the shift reaction unit heating unit 112 and the CO removal unit heating unit 123 are shifted by excessive temperature rise so that condensation does not occur in the shift reaction unit 111 and the CO removal unit 121. It adjusts moderately so that the reaction part 111 and the CO removal part 121 may not be damaged.

  Next, in step S23, the control unit 200 determines whether or not the temperature detected by the reforming unit temperature detection unit 105 is 200 ° C. or more, which is an example of the second predetermined temperature of the present invention. This determination is made because if the air is supplied when the temperature of the reforming unit 101 is 200 ° C. or higher, the reforming catalyst is oxidized and deteriorated.

  If it is 200 ° C. or higher in step S23, the raw material supply unit 102 is stopped by the control unit 200 in step S24. By stopping the raw material supply unit 102 and continuing the supply of water from the water supply unit 103, the supplied water is water vapor that is an example of the first purge gas of the present invention in the reforming unit 101. It becomes. The water vapor passes through the shift reaction unit 111 and the CO removal unit 121 and is discharged while purging the combustible gas mainly composed of hydrogen remaining in the hydrogen generator 1. The water supply unit 103 is the first purge gas supply unit of the present invention.

  Next, in step S <b> 25, the control unit 200 performs detection until the temperature detected by the reforming unit temperature detection unit 105 is less than 200 ° C.

  Next, after the temperature in the reforming unit 101 becomes less than 200 ° C., the operation of the water supply unit 103 is stopped by the control unit 200 in step S26, whereby the water vapor supply is stopped.

  Next, in step S27, the operation of the purge air supply unit 106 is started by the control unit 200, and the operation is continued for a predetermined time. As a result, the air is discharged out of the hydrogen generator 1 while purging the remaining water vapor in the hydrogen generator 1. That is, in the present embodiment, air becomes the second purge gas of the present invention. Further, the purge air supply unit 106 is the second purge gas supply unit of the present invention.

  Next, after the inside of the hydrogen generator 1 is completely purged with air, the shift reaction unit heating unit 112 and the CO removal unit heating unit 123 are stopped by the control unit 200 in step S28.

  Finally, in step S29, the air supply from the purge air supply unit 106 is also stopped, and the hydrogen generator 1 stop operation ends.

  On the other hand, if the temperature reformed by the reforming unit temperature detecting unit 105 is not 200 ° C. or higher in step S23, the reforming is possible even if purging with air is performed without purging the hydrogen generator 1 with steam. The quality catalyst is not oxidized. Therefore, when the temperature in the reforming unit 101 is not 200 ° C. or higher, the raw material supply unit 102 and the water supply unit 103 are stopped (step S30), and the process proceeds to step S27 in which air is further supplied.

  In the second embodiment, the shift reaction unit heating unit 112 and the CO removal unit heating unit 123 are operated even if the shift reaction unit 111 and the CO removal unit 121 are not higher than 100 ° C. As a result, unlike the first embodiment, there is no need to provide the shift reaction unit temperature detection unit 113 and the CO removal unit temperature detection unit 124, so that the apparatus configuration can be simplified and the cost can be reduced.

  The time for operating or stopping the shift reaction unit heating unit 112 and the CO removal unit heating unit 123 may vary depending on the apparatus configuration, the catalyst, and the like, and is not necessarily limited to the example described in the present embodiment. If the temperature of the shift reaction unit 111 and the CO removal unit 121 is adjusted so that the condensed water does not remain in the shift reaction unit 111 and the CO removal unit 121 at the end of the purge, the shift reaction unit heating unit 112 and The CO removal unit heating unit 123 may be operated at any timing.

Further, the hydrogen generator 1 according to the present embodiment does not necessarily need to be used for fuel supply to the PEFC, but is a chemical plant that requires the effects of supplying fuel to other fuel cells and synthesizing high-purity hydrogen. Etc.
(Procedure for Embodiments 1 and 2)
Further, the set temperature may vary depending on the apparatus configuration, the catalyst, etc., and is not necessarily limited to the temperature described in the first and second embodiments.

  Moreover, the operation stop method described in the first and second embodiments is an example, and is not limited to the described method. In the first embodiment, for example, step S2 (determination of the temperature in the shift reaction unit 111 and the CO removal unit 121) is performed before step S1 (stops the reforming unit heating unit 104), and heating is started. Good. Alternatively, step S10 (stop of the purge air supply unit 106) may be performed before step S9 (stop of the shift reaction unit heating unit 112 and the CO removal unit heating unit 123). Also in the second embodiment, step S22 may be performed before step S21, and step S29 may be performed before step S28.

  In the first and second embodiments, the first purge gas supply unit of the present invention also serves as the water supply unit 103 that supplies water for the reforming reaction. In addition, the first purge gas of the present invention is water vapor in the first and second embodiments, but may be a raw material gas or an inert gas. Further, the reforming section heating section 104 and the shift reaction section heating are possible. Combustion exhaust gas in which either the unit 112 or the CO removal unit heating unit 123 is operated may be used.

  Further, the second purge gas supply unit of the present invention corresponds to the purge air supply unit 106 in the first and second embodiments, and the second purge gas corresponds to air, but the purge air supply unit. The part 106 may be omitted, and the raw material may be the second purge gas. That is, the raw material may be supplied from the raw material supply unit 102 in order to purge and discharge the water vapor.

  In the first and second embodiments, the inside of the hydrogen generator 1 may be purged using an inert gas when stopped. Even at this time, the water vapor remaining in the reforming unit 101 does not condense in the shift reaction unit 111 and the CO removal unit 121.

  The program of the present invention is a program for causing a computer to execute the functions of the control unit of the hydrogen generator 1 of the present invention described above, and is a program that operates in cooperation with the computer.

  The recording medium of the present invention is a recording medium carrying a program for causing a computer to execute all or part of the functions of the control unit of the hydrogen generator 1 of the present invention described above, and is readable by a computer. The read program is a recording medium for executing the function in cooperation with the computer.

  Moreover, the function of the said control part of this invention means all or one part function.

  Further, one usage form of the program of the present invention may be an aspect in which the program is recorded on a computer-readable recording medium and operates in cooperation with the computer.

  Further, one usage form of the program of the present invention may be an aspect in which the program is transmitted through a transmission medium, read by a computer, and operated in cooperation with the computer.

  The data structure of the present invention includes a database, data format, data table, data list, data type, and the like.

  The recording medium includes a ROM and the like, and the transmission medium includes a transmission medium such as the Internet, light, radio waves, sound waves, and the like.

  The computer of the present invention described above is not limited to pure hardware such as a CPU, but may include firmware, an OS, and peripheral devices.

As described above, the configuration of the present invention may be realized by software or hardware.
(Embodiment 3)
FIG. 5 is a configuration diagram of the hydrogen generator 1 according to the third embodiment. The third embodiment is different from the first embodiment in that after the combustible gas mainly composed of hydrogen is purged with water vapor, the water vapor is purged with the raw material and discharged. Therefore, FIG. 5 has a configuration in which the purge air supply unit 106 used in the first embodiment is omitted. In FIG. 5, the same reference numerals are used for the same components as in FIG.

  An example of the control program during the operation stop operation of the hydrogen generator 1 of Embodiment 3 will be described with reference to the flowchart of FIG. The operation stop includes not only the end of the operation but also the operation in every case of stopping the production of hydrogen such as interruption. The operation stop operation time refers to the time during which a series of operations are performed from when a stop command is issued until the hydrogen generator is stopped.

  First, the reforming unit heating unit 104 is stopped by the control unit 200 in step S31.

  Next, in step S32, the temperature detected by the shift reaction unit temperature detection unit 113 or the temperature detected by the CO removal unit temperature detection unit 124 is 100 ° C. or less, which is an example of the first predetermined temperature of the present invention. Is determined by the control unit 200.

  Next, when the temperature is 100 ° C. or lower, in step S33, the control unit 200 operates the shift reaction unit heating unit 112 and the CO removal unit heating unit 123 to start heating the shift reaction unit 111 and the CO removal unit 121. At this time, the control unit 200 controls heating so that the temperatures detected by the shift reaction unit temperature detection unit 113 and the CO removal unit temperature detection unit 124 are higher than 100 ° C. By this heating, the water vapor supplied later is not condensed on the shift reaction catalyst and the CO removal catalyst, and is discharged out of the hydrogen generator 1.

  Next, in step S34, the control unit 200 determines whether or not the temperature detected by the reforming unit temperature detection unit 105 is 400 ° C. or more, which is an example of the second predetermined temperature of the present invention. This determination is made when the supply of water is stopped and only the raw material is supplied when the temperature of the reforming unit 101 is 400 ° C. or higher, and carbon is deposited on the reforming catalyst, resulting in a decrease in catalyst characteristics. It is because it ends up.

  When the temperature is 400 ° C. or higher in step S34, the raw material supply unit 102 is stopped by the control unit 200 in step S35. By stopping the raw material supply unit 102 and continuing the supply of water from the water supply unit 103, the supplied water is water vapor that is an example of the first purge gas of the present invention in the reforming unit 101. It becomes. The water vapor passes through the shift reaction unit 111 and the CO removal unit 121 and is discharged while purging the combustible gas mainly composed of hydrogen remaining in the hydrogen generator 1. In the present embodiment, the water supply unit 103 serves as the first purge gas supply unit of the present invention.

  Next, in step S36, the control unit 200 performs detection until the temperature detected by the reforming unit temperature detection unit 105 is less than 400 ° C.

  Next, after the temperature in the reforming unit 101 becomes less than 400 ° C., the operation of the water supply unit 103 is stopped by the control unit 200 in step S37, whereby the water vapor supply is stopped.

  Next, in step S38, the control unit 200 restarts the operation of the raw material supply unit 102 and continues the operation for a predetermined time, so that the raw material is purged from the hydrogen generating device 1 while purging the remaining water vapor in the hydrogen generating device 1. Is discharged. That is, in the present embodiment, the raw material is the second purge gas of the present invention. The raw material supply unit 102 is the second purge gas supply unit of the present invention. Here, the predetermined time is a time sufficient to expel water vapor from the hydrogen generator 1, but when the shift reaction unit 111 and the CO removal unit 121 are not higher than 100 ° C. by step S38. Even if the raw material purge operation in step S38 is performed, it is necessary to perform the raw material purge for a predetermined time after the temperature becomes higher than 100 ° C. If the water vapor purge is performed when the temperature is not higher than 100 ° C., the water vapor may be condensed. is there.

  Next, after the inside of the hydrogen generator 1 is completely purged with the raw material, the shift reaction unit heating unit 112 and the CO removal unit heating unit 123 are stopped by the control unit 200 in step S39.

  Finally, in step S40, the raw material supply from the raw material supply unit 102 is also stopped, and the hydrogen generator 1 stopping operation ends.

  On the other hand, if the temperatures detected by the shift reaction unit temperature detection unit 113 and the CO removal unit temperature detection unit 124 are not both 100 ° C. or lower in step S32, condensation of water vapor does not occur even if heating is not performed. Therefore, the shift reaction unit heating unit 112 and the CO removal unit heating unit 123 are not operated. Proceed to step S44.

  Next, in step S44, the controller 200 determines whether or not the temperature in the reforming unit 101 is 400 ° C. or higher (same as step S34 above).

  Next, in step S45, the raw material supply unit 102 is stopped (same as step S35).

  Next, detection is performed until the temperature detected by the reforming unit temperature detection unit 105 is less than 400 ° C. in step S46 (same as step S36).

  After the temperature in the reforming unit 101 becomes less than 400 ° C., the operation of the water supply unit 103 is stopped in step S47 (same as step S37 above).

  Next, in step S48, the operation of the raw material supply unit 102 is resumed and the operation is continued for a predetermined time, whereby the inside of the hydrogen generator 1 is completely purged with the raw material (same as step S38 above).

  Finally, in step S40, the supply of the raw material from the raw material supply unit 102 is stopped.

  On the other hand, if the temperature reformed by the reforming unit temperature detection unit 105 is not 400 ° C. or higher in step S34 and step S44, purging with the raw material is performed without purging the hydrogen generator 1 with water vapor. However, carbon does not deposit on the reforming catalyst and the catalytic properties are not deteriorated. Therefore, when the temperature in the reforming unit 101 is not 400 ° C. or higher, the water supply unit 103 is stopped (step S49) from step S34, and then the process proceeds to step S39. In step S44, the water supply unit 103 is stopped (step S50), and then the process proceeds to step S40.

  As described above, the shift reaction unit 111 and the CO removal unit 121 can be held at a temperature higher than 100 ° C. by performing a stop operation that activates the shift reaction unit heating unit 112 and the CO removal unit heating unit 123. For this reason, the water vapor at the time of purging does not condense in the shift reaction unit 111 and the CO removal unit 121, and the water vapor does not remain in the shift reaction unit 111 and the CO removal unit 121 to condense. It is possible to prevent a decrease in catalyst characteristics.

  The stop operation as described above is not limited to the unsteady state immediately after the hydrogen generator 1 starts to start, but may correspond to the operation in the steady state.

  In steps S32 and S33, both the heating is performed when the temperature in the shift reaction unit 111 or the CO removal unit 121 is 100 ° C. or lower. Good.

  Further, in steps S32, S34, and S44, the next step differs depending on the determination result, but the operations in steps S31 to S40 may always be performed without providing the determination in steps S32, S34, and S44. However, if the supply of water is stopped when the internal temperature of the reforming unit 101 is 400 ° C. or more and only the raw material is supplied, carbon may be deposited on the reforming catalyst and the catalyst characteristics may be deteriorated. Is preferred.

  In step S39, the shift reaction unit heating unit 112 and the CO removal unit heating unit 123 are stopped. However, the shift reaction unit temperature detection unit 113 and the CO removal unit temperature detection unit 124 are not limited to step S39. 111 and the temperature in the CO removal unit 121 may be monitored, and control may be performed so that the operation is performed when the temperature is 100 ° C. or lower, and is stopped when the temperature is not 100 ° C. or lower.

  If the temperature in the shift reaction unit 111 or the CO removal unit 121 is not 100 ° C. or lower in step S32, the shift reaction unit heating unit 112 and the CO removal unit heating unit 123 are not operated, and the process from step S44 to step S48 is performed. Although the operation is performed, the temperature may be monitored and the shift reaction unit heating unit 112 and the CO removal unit heating unit 123 may be heated when the temperature becomes 100 ° C. or lower.

  The determination of whether or not the shift reaction unit 111 and the CO removal unit 121 are 100 ° C. or less (step S32) and the operation of the shift reaction unit heating unit 112 and the CO removal unit heating unit 123 (step S33) are as follows. The operation may be performed immediately before the operation of the unit 102 is resumed (step S38). Alternatively, the raw material supply unit 102 may be operated to purge the inside of the hydrogen generator 1 with the raw material. In any case, if the temperature of the shift reaction unit 111 and the CO removal unit 121 is adjusted so that the condensed water does not remain in the shift reaction unit 111 and the CO removal unit 121 at the end of the purge, the shift reaction unit heating is performed. The unit 112 and the CO removal unit heating unit 123 may be operated at any timing.

  Further, as shown in the second embodiment, the shift reaction unit 111 and the CO removal unit 121 may always be heated without performing the determination based on the temperature in the operation stop operation. . In this case, the shift detection unit 111 and the CO removal unit 121 may not be provided with a temperature detection unit.

Further, the hydrogen generator 1 according to the present embodiment does not necessarily need to be used for fuel supply to the PEFC, but is a chemical plant that requires the effects of supplying fuel to other fuel cells and synthesizing high-purity hydrogen. Etc.
(Embodiment 4)
The configuration diagram of the hydrogen generator 1 in the fourth embodiment is FIG. 5 as in the third embodiment. The fourth embodiment is different from the third embodiment in that purging with a raw material is performed without purging with water vapor.

  An example of the control program during the operation stop operation of the hydrogen generator 1 of Embodiment 4 will be described with reference to the flowchart of FIG. The operation stop includes not only the end of the operation but also the operation in every case of stopping the production of hydrogen such as interruption. The operation stop operation time refers to the time during which a series of operations are performed from when a stop command is issued until the hydrogen generator is stopped.

  First, the reforming unit heating unit 104 is stopped by the control unit 200 in step S51.

  Next, in step S52, the temperature detected by the shift reaction unit temperature detection unit 113 or the temperature detected by the CO removal unit temperature detection unit 124 is 100 ° C. or less, which is an example of the first predetermined temperature of the present invention. Is determined by the control unit 200.

  Next, in the case of 100 ° C. or lower, in step S53, the control unit 200 operates the shift reaction unit heating unit 112 and the CO removal unit heating unit 123 to start heating the shift reaction unit 111 and the CO removal unit 121. At this time, the control unit 200 controls heating so that the temperatures detected by the shift reaction unit temperature detection unit 113 and the CO removal unit temperature detection unit 124 are higher than 100 ° C. By this heating, the water vapor supplied later is not condensed on the shift reaction catalyst and the CO removal catalyst, and is discharged out of the hydrogen generator 1.

  Next, in step S54, the control unit 200 determines whether or not the temperature detected by the reforming unit temperature detection unit 105 is 400 ° C. or more, which is an example of the second predetermined temperature of the present invention. This determination is made when the supply of water is stopped and only the raw material is supplied when the temperature of the reforming unit 101 is 400 ° C. or higher, and carbon is deposited on the reforming catalyst, resulting in a decrease in catalyst characteristics. It is because it ends up.

  When the temperature is 400 ° C. or higher in step S54, the raw material supply unit 102 and the water supply unit 103 are stopped by the control unit 200 in step S55.

  Next, in step S56, the control unit 200 performs detection until the temperature detected by the reforming unit temperature detection unit 105 is less than 400 ° C.

  Next, after the temperature in the reforming unit 101 becomes less than 400 ° C., in step S57, the control unit 200 restarts the operation of the raw material supply unit 102 and operates for a predetermined time. The inside of the hydrogen generator 1 is discharged while purging the combustible gas mainly composed of hydrogen. Here, the predetermined time is a time sufficient to expel water vapor from the hydrogen generator 1, but when the shift reaction unit 111 and the CO removal unit 121 are not higher than 100 ° C. by step S57. Even if the raw material purge operation in step S57 is performed, it is necessary to perform the raw material purge for a predetermined time after the temperature becomes higher than 100 ° C. If the water vapor purge is performed when the temperature is not higher than 100 ° C., the water vapor may be condensed. is there.

  Next, after the inside of the hydrogen generator 1 is completely purged with the raw material, the shift reaction unit heating unit 112 and the CO removal unit heating unit 123 are stopped by the control unit 200 in step S58.

  Finally, in step S59, the raw material supply from the raw material supply unit 102 is also stopped, and the hydrogen generator 1 stopping operation is completed.

  On the other hand, if both the temperatures detected by the shift reaction unit temperature detection unit 113 and the CO removal unit temperature detection unit 124 are not 100 ° C. or lower in step S52, condensation of water vapor does not occur even if heating is not performed. Therefore, the shift reaction unit heating unit 112 and the CO removal unit heating unit 123 are not operated. Proceed to step S64.

  Next, in step S64, it is determined by the control unit 200 whether or not the temperature in the reforming unit 101 is 400 ° C. or higher (same as step S54 above).

  Next, in step S65, the raw material supply unit 102 and the water supply unit 103 are stopped (same as step S55 above).

  Next, detection is performed until the temperature detected by the reforming unit temperature detection unit 105 is less than 400 ° C. in step S66 (same as step S56 above).

  After the temperature in the reforming unit 101 becomes less than 400 ° C., the operation of the raw material supply unit 102 is restarted in step S67, and the operation is continued for a predetermined time. Purged (same as step S57 above).

  Finally, in step S59, the supply of the raw material from the raw material supply unit 102 is stopped.

  On the other hand, in step S54 and step S64, when the temperature reformed by the reforming unit temperature detection unit 105 is not 400 ° C. or higher, purging with the raw material is performed without purging the hydrogen generator 1 with steam. However, carbon does not deposit on the reforming catalyst and the catalytic properties are not deteriorated. Therefore, if the temperature in the reforming unit 101 is not 400 ° C. or higher, the water supply unit 103 is stopped (step S68) from step S54, and then the process proceeds to step S58. Further, from step S64, the water supply unit 103 is stopped (step S69), and then the process proceeds to step S59.

As described above, the shift reaction unit 111 and the CO removal unit 121 can be held at a temperature higher than 100 ° C. by performing a stop operation that activates the shift reaction unit heating unit 112 and the CO removal unit heating unit 123. For this reason, water vapor at the time of purging does not condense in the shift reaction unit 111 and the CO removal unit 121, and water vapor does not remain and condense in the shift reaction unit 111 and the CO removal unit 121. It is possible to prevent a decrease in catalyst characteristics.
Further, by omitting the purge operation with water vapor, the time during which the catalyst is exposed to water vapor is reduced, so that the deterioration of the catalyst characteristics can be further prevented.

  The stop operation as described above is not limited to the unsteady state immediately after the hydrogen generator 1 starts to start, but may correspond to the operation in the steady state.

  In steps S52 and S53, both of the heating are performed when the temperature in the shift reaction unit 111 or the CO removing unit 121 is 100 ° C. or lower. Good.

  Further, in steps S52, S54, and S64, the next step differs depending on the determination result, but the operations in steps S51 to S59 may always be performed without providing the determination in steps S52, S54, and S64. However, if the supply of water is stopped when the internal temperature of the reforming unit 101 is 400 ° C. or higher and only the raw material is supplied, carbon may be deposited on the reforming catalyst and the catalyst characteristics may be deteriorated. Is preferred.

  In addition, the shift reaction unit heating unit 112 and the CO removal unit heating unit 123 are stopped in step S58. However, the shift reaction unit temperature detection unit 113 and the CO removal unit temperature detection unit 124 are not limited to step S58. 111 and the temperature in the CO removing unit 121 may be monitored, and control may be performed so as to operate when the temperature is 100 ° C. or lower and to stop when the temperature is not lower than 100 ° C.

  If the temperature in the shift reaction unit 111 or the CO removal unit 121 is not 100 ° C. or lower in step S52, the shift reaction unit heating unit 112 and the CO removal unit heating unit 123 are not operated, and the process from step S64 to step S67 is performed. Although the operation is performed, the temperature may be monitored and the shift reaction unit heating unit 112 and the CO removal unit heating unit 123 may be heated when the temperature becomes 100 ° C. or lower.

  The determination of whether or not the shift reaction unit 111 and the CO removal unit 121 are 100 ° C. or lower (step S52) and the operation of the shift reaction unit heating unit 112 and the CO removal unit heating unit 123 (step S53) The operation may be performed immediately before the operation of the unit 102 is resumed (step S57). Alternatively, the raw material supply unit 102 may be operated to purge the inside of the hydrogen generator 1 with the raw material. In any case, if the temperature of the shift reaction unit 111 and the CO removal unit 121 is adjusted so that the condensed water does not remain in the shift reaction unit 111 and the CO removal unit 121 at the end of the purge, the shift reaction unit heating is performed. The unit 112 and the CO removal unit heating unit 123 may be operated at any timing.

  Further, as shown in the second embodiment, the shift reaction unit heating unit 112 and the CO removal unit heating unit 123 may be operated for a predetermined time. In this case, the shift detection unit 111 and the CO removal unit 121 may not be provided with a temperature detection unit.

Further, the hydrogen generator 1 according to the present embodiment does not necessarily need to be used for fuel supply to the PEFC, but is a chemical plant that requires the effects of supplying fuel to other fuel cells and synthesizing high-purity hydrogen. Etc.
(Embodiment 5)
The present embodiment is a fuel cell system 2 including the hydrogen generator 1 and the fuel cell according to the first to fourth embodiments. The fuel cell system 2 uses the hydrogen-rich gas generated by the hydrogen generator 1 according to Embodiments 1 to 4 as the fuel for the fuel cell 125.

  FIG. 9 is a block diagram showing an example of a schematic configuration of the fuel cell system 2 according to the present embodiment. The fuel cell system 2 shown in FIG. 9 is obtained by adding a fuel cell 125 to the hydrogen generator 1 according to the first embodiment. Therefore, elements common in FIGS. 1 and 9 are denoted by the same reference numerals and description thereof is omitted.

  The fuel cell 125 is a fuel cell that generates power using hydrogen-rich gas as fuel. The fuel supply port of the fuel cell 125 is connected to the CO removal unit 121. The hydrogen-rich gas generated by the hydrogen generator 1 is supplied to the fuel cell 125. In the present embodiment, for example, a polymer electrolyte fuel cell (PEFC) is used as the fuel cell 125.

  By having the above-described configuration, the fuel cell system 2 according to the present embodiment can prevent water from condensing in the carbon monoxide reduction unit during the shutdown operation. Therefore, it is possible to prevent the catalyst of the carbon monoxide reduction unit from deteriorating. Therefore, the life of the fuel cell system can be extended.

  Note that the hydrogen generator 1 in the present embodiment is not limited to the hydrogen generator 1 in the first embodiment, and the hydrogen generator 1 in the second to fourth embodiments may be used.

  The hydrogen generator according to the present invention has an effect of further preventing deterioration of the catalyst, and is useful for use in a fuel cell or the like that generates power using the generated hydrogen. It is also applicable to chemical plants that require the effect of synthesizing high purity hydrogen.

It is a block diagram of the hydrogen generator in Embodiment 1 concerning this invention. It is a flowchart explaining an example of the control program at the time of the operation stop operation of the hydrogen generator in Embodiment 1 concerning this invention. It is a block diagram of the hydrogen generator in Embodiment 2 concerning this invention. It is a flowchart explaining an example of the control program at the time of operation stop operation of the hydrogen generator in Embodiment 2 concerning this invention. It is a block diagram of the hydrogen generator in Embodiment 3 concerning this invention. It is a flowchart explaining an example of the control program at the time of the operation stop operation of the hydrogen generator in Embodiment 3 concerning this invention. It is a flowchart explaining an example of the control program at the time of the operation stop operation of the hydrogen generator in Embodiment 4 concerning this invention. It is a wiring diagram which shows schematic structure of the control apparatus 200 in Embodiment 1 concerning this invention. It is a block diagram which shows an example of schematic structure of the fuel cell system 2 in Embodiment 5 concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydrogen generator 2 Fuel cell system 101 Reforming part 102 Raw material supply part 103 Water supply part 104 Reforming part heating part 105 Reforming part temperature detection part 106 Purge air supply part 111 Shift reaction part 112 Shift reaction part heating part 113 Shift reaction unit temperature detection unit 121 CO removal unit 122 Air supply unit 123 CO removal unit heating unit 124 CO removal unit temperature detection unit 125 Fuel cell 200 Control unit 201 I / O input port 202 CPU
203 Storage Device 204 I / O Output Port 205 Bus 206 Input Device 207 Output Device

Claims (11)

A reforming section having a reforming catalyst that reacts the raw material with water to generate a hydrogen-rich reformed gas;
A reforming section heating section for heating the reforming section;
A carbon monoxide reduction section having a carbon monoxide reduction catalyst for reducing carbon monoxide in the reformed gas;
A carbon monoxide reduction heating unit for heating at least one of the carbon monoxide reduction unit, the carbon monoxide reduction catalyst, and the reformed gas passing through the carbon monoxide reduction unit;
A control unit,
Hydrogen generation characterized by operating the carbon monoxide reduction heating unit so as to be higher than a first predetermined temperature at which the water vapor in the carbon monoxide reduction unit does not condense when the operation is stopped apparatus. The carbon monoxide reduction unit is a shift reaction unit or a CO removal unit,
The carbon monoxide reduction heating unit is a shift reaction unit heating unit or a CO removal unit heating unit,
The carbon monoxide reduction catalyst of the shift reaction unit is a shift reaction catalyst,
The carbon monoxide reduction catalyst that the CO removal unit has includes at least one of a selective oxidation catalyst and a methanation catalyst,
The hydrogen generator according to claim 1. A carbon monoxide reduction unit temperature detection unit for detecting the temperature of the carbon monoxide reduction unit;
During the shutdown operation, while the temperature of the carbon monoxide reduction unit is at least the first predetermined temperature or less, the control unit controls the carbon monoxide reduction heating unit.
The hydrogen generator according to claim 1. When the operation is stopped, based on the stop command, the control unit controls the carbon monoxide reduction heating unit.
The hydrogen generator according to claim 1. After a certain time has elapsed since the stop command was issued, the operation of the carbon monoxide reduction heating unit is stopped by the control of the control unit,
The hydrogen generator according to claim 4. A reforming unit temperature detection unit for detecting the temperature of the reforming unit;
During the shutdown operation, the control of the control unit stops the supply of raw materials and water,
Under the control of the control unit, the carbon monoxide reduction heating unit is operated,
When the temperature detected by the reforming unit temperature detection unit reaches a temperature at which no carbon is deposited on the reforming catalyst, the control of the control unit supplies the raw material to purge the inside of the hydrogen generator,
Thereafter, the control of the control unit stops the supply of the raw material and the operation of the carbon monoxide reduction heating unit.
The hydrogen generator according to claim 1. A first purge gas supply unit for supplying a first purge gas;
A second purge gas supply unit for supplying a second purge gas;
A reforming unit temperature detection unit for detecting the temperature of the reforming unit,
During the stop operation,
When the temperature detected by the reforming unit temperature detection unit is lower than the second predetermined temperature, the second generation gas is controlled by the control unit until the hydrogen generator is filled with the second purge gas. Operate the supply section,
When the temperature detected by the reforming unit temperature detection unit is not less than a second predetermined temperature, the control unit controls the first purge gas supply unit to operate the reforming unit temperature detection unit. After the detected temperature by the temperature becomes lower than the second predetermined temperature, the control of the control unit causes the second purge gas supply unit to be filled with the second purge gas under the control of the control unit. Make it work,
The hydrogen generator according to claim 1. The first purge gas is water vapor;
The second purge gas is air;
The second predetermined temperature is a temperature at which the reforming catalyst is not oxidized.
The hydrogen generator according to claim 7. The first purge gas is water vapor;
The second purge gas is a raw material,
The second predetermined temperature is a temperature at which carbon is not deposited on the reforming catalyst.
The hydrogen generator according to claim 7. The first purge gas is either a combustion exhaust gas or an inert gas.
The hydrogen generator according to claim 7. A hydrogen generator according to any one of claims 1 to 10,
A fuel cell that generates power using hydrogen generated by the hydrogen generator,
Fuel cell system.

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