JP2011090864A - Fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell system, which determines, whether feed rates of raw material and water supplied from raw material and water supply parts to a hydrogen generation device are adequate. <P>SOLUTION: An operation control unit 16 has functions to operate a fuel cell 8 without following a change in power load for a preset period after generation of optional electricity of the fuel cell 8; operate a raw material supply unit 4 and a water supply unit 3 at preset instruction values; determine, when a temperature difference between a predicted reforming temperature predicted from the instruction values and a detected reforming temperature detected by a reforming temperature detection unit 24 is a predetermined temperature difference or more, that raw material corresponding to the preset instruction value is not supplied from the raw material supply unit 4 as instructed, or that water corresponding to the preset instruction value is not supplied from the water supply unit 3 as instructed; and further correct the feed rate of raw material corresponding to a raw material instruction value or the feed rate of water corresponding to a water instruction value, or the operation control unit has a function to externally output an alarm. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a fuel cell system including a hydrogen generator that generates a hydrogen-containing gas having a low carbon monoxide concentration from a fossil raw material or the like.

  Development of a fuel cell system using a fuel cell stack (hereinafter simply referred to as “fuel cell”) that enables high-efficiency power generation even with a small device as a distributed energy supply source is in progress. A fuel cell system supplies a hydrogen-containing gas and an oxygen-containing gas to a fuel cell, which is the main body of a power generation unit, and proceeds with an electrochemical reaction between hydrogen and oxygen to generate chemical energy. This is a system that generates electricity by taking it out as natural energy.

  In general, hydrogen-containing gas is not supplied from the infrastructure. Therefore, a conventional fuel cell system uses a city gas or LPG supplied from an existing infrastructure as a raw material, and reforms with a steam reaction at a temperature of 600 to 700 ° C. using a Ru catalyst or a Ni catalyst. A hydrogen generation apparatus having a section is provided. Note that the hydrogen-containing gas obtained by the reforming reaction usually contains carbon monoxide derived from the raw material, and when the concentration is high, the power generation characteristics of the fuel cell are degraded. Therefore, in addition to the reforming unit, the hydrogen generator has a Cu—Zn-based catalyst or a noble metal that reduces carbon monoxide by advancing a transformation reaction between carbon monoxide and water vapor at a temperature of 200 ° C. to 350 ° C. And a reaction section such as a selective oxidation section equipped with a Ru catalyst or a PT catalyst, which selectively reduces carbon monoxide by selectively oxidizing carbon monoxide at a temperature of 100 ° C. to 200 ° C. Is provided. Further, in order to improve the efficiency of the fuel cell system, a hydrogen-containing gas (hereinafter referred to as “anode off gas”) discharged from the anode during power generation of the fuel cell is often burned by a hydrogen generator and used for the reforming reaction. .

  As described above, the hydrogen generator is composed of a reforming unit, a shift unit, a selective oxidation unit, and the like, and generates a certain amount of hydrogen and hydrogen with a low carbon monoxide concentration in a steady state and a transitional period. In order to achieve this, it is necessary to strictly control the temperature of the catalyst in each reaction section within a certain range. Therefore, a temperature detector is installed near the downstream side of the reforming unit, the transformation unit, and the selective oxidation unit. In the reforming unit, the heating amount of the reforming unit is increased or decreased based on the temperature detected by the temperature detector, and the selective oxidation is performed. In the unit, the temperature of each reaction unit is appropriately controlled by increasing or decreasing the cooling amount of the cooler provided on the upstream side based on the temperature detected by the temperature detector (for example, Patent Documents). 1). Also, the temperature of the shift section is appropriately controlled by increasing or decreasing the amount of water supplied to the preheating evaporator or increasing or decreasing the combustion air supply to the heating section based on the temperature detected by the temperature detector of the shift section. The structure is taken (for example, refer patent document 2).

JP 2001-180905 A JP 2008-0119159 A

However, due to an abnormality in the raw material supply unit and the water supply unit supplied to the hydrogen generator, the raw material instruction value, the raw material supply amount corresponding to the water instruction value, and the water supply amount are not supplied to the hydrogen generator. And it cannot produce hydrogen with low carbon monoxide concentration. Further, when the ratio of water to the raw material (steam carbon ratio (hereinafter referred to as “S / C”)) becomes small, carbon is deposited on the reforming catalyst, leading to failure of the hydrogen generator. Furthermore, the ratio of water to raw material (S / C
) Increases, moisture condenses at low temperatures, and the catalyst deteriorates, leading to failure of the hydrogen generator. Therefore, it is desired to realize a hydrogen generator that can easily and quickly grasp whether the supply amount from each supply unit is appropriate.

  In order to solve the above problems, in the fuel cell system of the present invention, a reforming unit that supplies raw material and water to generate a hydrogen-containing gas by a reforming reaction, and the reforming unit according to the raw material supply amount instruction value A raw material supply unit that supplies the raw material, a water supply unit that supplies water to the reforming unit according to the water supply amount instruction value, and a modification that reduces the concentration of carbon monoxide in the hydrogen-containing gas generated by the reforming unit. And a transformation temperature detection unit for detecting the temperature of the transformation unit, and a hydrogen-containing gas and an oxygen-containing gas having a reduced carbon monoxide concentration are supplied to the power generation unit to generate power and change the power load of the power supply destination. Necessary for the reforming reaction of the reforming unit by burning the remaining fuel-containing gas that was not consumed by the fuel cell among the fuel cell that generates power by following and the hydrogen-containing gas whose carbon monoxide concentration was reduced in the shift unit Detected by the combustor that supplies heat and the metamorphic temperature detector An operation control unit that outputs a raw material supply amount instruction value to the raw material supply unit based on the transformation temperature and outputs a water supply amount instruction value to the water supply unit, and the operation control unit includes an arbitrary power generation amount that the fuel cell has The fuel cell is operated without following the change in the power load for a preset period after the power is generated, and the raw material supply unit and the water supply unit are operated at the preset instruction values, and are predicted from the instruction values. If the temperature difference between the expected transformation temperature and the detected transformation temperature detected by the transformation temperature detection unit is equal to or greater than the predetermined temperature difference, the raw material corresponding to the preset instruction value is supplied from the raw material supply unit as instructed. It is determined that the water corresponding to the command value not set or set in advance is not supplied from the water supply unit as instructed, and further, the raw material supply amount corresponding to the material command value or the water command value Correct the water supply corresponding to Made with a function, or a configuration made with a function of external output an alarm.

  According to the fuel cell system of the present invention, it is determined whether the raw material supply amount and the water supply amount supplied from the raw material supply unit and the water supply unit to the hydrogen generator are appropriate, and further, the raw material supply corresponding to the raw material indication value The water supply amount corresponding to the amount or the water indication value can be corrected. As a result, a certain amount of hydrogen and hydrogen with a low carbon monoxide concentration can be generated. Further, it is possible to determine whether the raw material supply amount and the water supply amount supplied from the raw material supply unit and the water supply unit to the hydrogen generator are abnormal, and an alarm can be output to the outside. As a result, failure of the hydrogen generator can be prevented in advance.

1 is a schematic configuration diagram of a fuel cell system according to Embodiment 1 of the present invention. The flowchart which shows typically 1 cycle of the characteristic operation | movement of the hydrogen generator in Embodiment 1 of this invention.

According to a first aspect of the present invention, there is provided a reforming unit that supplies a raw material and water to generate a hydrogen-containing gas by a reforming reaction, a raw material supply unit that supplies the reforming unit with a raw material according to a raw material supply amount instruction value, A water supply unit that supplies water according to a water supply amount instruction value to the mass part, a shift unit that reduces the concentration of carbon monoxide in the hydrogen-containing gas generated by the reforming unit, and a temperature of the shift unit are detected. A metamorphic temperature detection unit, a fuel cell that generates power by supplying a hydrogen-containing gas and an oxygen-containing gas whose carbon monoxide concentration has been reduced in the metamorphic unit, and generates power following changes in the power load of the power supply destination; A combustion section that burns the remaining hydrogen-containing gas that has not been consumed by the fuel cell among the hydrogen-containing gas whose carbon monoxide concentration has been reduced in the section, and supplies heat necessary for the reforming reaction of the reforming section; The amount of raw material supplied to the raw material supply unit based on the transformation temperature detected by the temperature detector An operation control unit that outputs the indicated value and outputs a water supply amount instruction value to the water supply unit, and the operation control unit is configured to perform fuel for a preset period after generating an arbitrary power generation amount of the fuel cell. The battery is operated without following the change in the power load, the raw material supply unit and the water supply unit are operated at preset instruction values, and the expected transformation temperature expected from the indication values and detected by the transformation temperature detection unit. If the temperature difference from the detected transformation temperature is equal to or greater than the predetermined temperature difference, the raw material corresponding to the preset instruction value is not supplied as instructed from the raw material supply unit, or the preset instruction value It is judged that the water corresponding to is not supplied as instructed from the water supply unit, and further has a function of correcting the raw material supply amount corresponding to the raw material instruction value or the water supply amount corresponding to the water instruction value. Or alarm external And made to have the ability to force made-up.

  According to a second aspect of the invention, in particular, in the fuel cell system of the first aspect of the invention, the operation control unit changes the fuel cell to a change in power load for a preset period after generating any amount of power generation that the fuel cell has. Operate without tracking, operate the raw material supply unit and the water supply unit with a preset instruction value, and the detected transformation temperature detected by the transformation temperature detection unit is higher than the expected transformation temperature expected from the instruction value. If it is high, a large amount of raw material corresponding to the preset instruction value is supplied from the raw material supply unit, or a small amount of water corresponding to the preset instruction value is supplied from the water supply unit, Alternatively, when the detected transformation temperature detected by the transformation temperature detection unit is lower than the expected transformation temperature expected from the indicated value, less raw material corresponding to the preset indicated value is supplied from the raw material supply unit. Or It is determined that a large amount of water corresponding to the specified instruction value is supplied from the water supply unit, and further, the raw material supply amount corresponding to the raw material instruction value or the water supply amount corresponding to the water instruction value is corrected. Or a function for outputting an alarm externally.

  According to a third aspect of the invention, in particular, in the fuel cell system of the first aspect of the invention, the operation control unit causes the fuel cell to change the power load during a preset period after generating an arbitrary amount of power generated by the fuel cell. The detected transformation temperature detected by the transformation temperature detection unit is operated rather than the expected transformation temperature expected from the instruction value by operating the raw material supply unit and the water supply unit with the instruction values set in advance. If it is high, decrease the indicated value to the raw material supply unit and increase the indicated value to the water supply unit, or the detected transformation temperature detected by the transformation temperature detection unit from the expected transformation temperature expected from the indication value. If it is lower, the instruction value to the raw material supply unit is increased and the instruction value to the water supply unit is decreased.

  According to a fourth aspect of the present invention, in particular, in the fuel cell system of the first aspect, the operation control unit causes the fuel cell to change the power load during a preset period after generating an arbitrary amount of power generated by the fuel cell. Operate without tracking, operate the raw material supply unit and the water supply unit with a preset instruction value, and the detected transformation temperature detected by the transformation temperature detection unit is higher than the expected transformation temperature expected from the instruction value. If it is higher, or if the detected transformation temperature detected by the transformation temperature detection unit is lower than the expected transformation temperature expected from the indicated value, the raw material supply amount from the raw material supply unit or the water from the water supply unit It is determined that the supply amount is abnormal and has a function of outputting an alarm externally.

  Hereinafter, embodiments of the present invention will be described more specifically with reference to the drawings.

(Embodiment 1)
<Configuration of fuel cell system>
FIG. 1 is a schematic configuration diagram showing Embodiment 1 of a fuel cell system 100 according to the present invention.

The fuel cell system 100 includes a hydrogen generator 1 that generates a hydrogen-containing gas, a fuel cell 8 that generates power using the hydrogen-containing gas supplied from the hydrogen generator 1, and a switch from the hydrogen generator 1 to the fuel cell 8. Hydrogen gas supply path 12 for supplying hydrogen gas via valve 9A, and off-gas supply path 14 for supplying anode off-gas discharged from fuel cell 8 to combustion section 2 of hydrogen generator 1 via switching valve 9B I have. The switching valve 9A is connected to the switching valve 9B by the fuel cell bypass path 23. In addition, since it is a structure equivalent to the general solid polymer type fuel cell 8, detailed description of another structure is abbreviate | omitted.

  The hydrogen generator 1 includes a water supply unit 3 that supplies water to the hydrogen generator 1 and a desulfurization unit 5 that allows a hydrocarbon-based raw material containing a sulfur component to pass therethrough and adsorbs and removes the sulfur component contained in the raw material. A reformer 22 that generates a hydrogen-containing gas using the raw material after passing through the desulfurization unit 5 and the water supplied from the water supply unit 3, and the flow rate of the raw material supplied to the desulfurization unit 5 (raw material) A raw material supply unit 4 for controlling the flow rate) and an operation control unit 16 for controlling operations of the raw material supply unit 4 and the water supply unit 3.

  The reformer 22 is spiral, evaporates the water supplied from the water supply unit 3, and advances the reforming reaction between the raw material and water vapor, and the water vapor generation unit 15 that preheats the mixed gas of the raw material and water vapor. The reforming unit 20 includes a shift unit 13 that performs a shift reaction of carbon monoxide and water vapor in the hydrogen-containing gas generated in the reforming unit 20 to reduce the carbon monoxide concentration of the hydrogen-containing gas. Further, the carbon monoxide remaining in the hydrogen-containing gas after passing through the shifter 13 is mainly oxidized using air supplied from the air supply unit 19 to the hydrogen-containing gas after passing through the shifter 13. And a selective oxidation portion 17 to be removed. The reforming section 20 is provided with a Ru-based reforming catalyst, the shift section 13 is provided with a Cu—Zn-based shift catalyst, and the selective oxidation section 17 is provided with a Ru-based selective oxidation catalyst. Further, a reforming temperature detection unit 21 that detects the temperature (reaction temperature) of the reforming catalyst (or hydrogen-containing gas) in the reforming unit 20, and the temperature (reaction temperature) of the shift catalyst (or hydrogen-containing gas) in the shift unit 13. Is provided with a metamorphic temperature detector 24 for detecting.

  The reformer 22 includes a combustion unit 2 for supplying reaction heat necessary for the reforming reaction in the reforming unit 20. The combustion unit 2 includes a burner that burns combustion gas that serves as a heating source, and a combustion fan 18 that serves as a combustion air supply unit that supplies fuel air to the combustion unit 2. Combustion gas burned in the combustion unit 2 is supplied to the combustion unit 2 from the hydrogen gas supply path 12 via the fuel cell bypass path 23 or via the fuel cell 8 from the off-gas supply path 14. The hydrogen-containing gas generated by the reformer 22 is supplied to the fuel cell 8 through the hydrogen gas supply path 12.

  In addition, the reforming unit 20 and the steam generation unit 15 are configured to be supplied with heat from the flue gas generated in the combustion unit 2 through the wall surface of the inner cylinder 11. In addition, the water vapor generation unit 15 is configured to exchange heat with the transformation unit 13 and the selective oxidation unit 17 through the wall surface of the middle cylinder 25. In addition, in the structure of the modification part 20, the transformation part 13, and the selective oxidation part 17, the illustration about the same structure part as a general structure and detailed description are abbreviate | omitted.

  The hydrocarbon-based raw material supplied to the desulfurization section 5 may be a raw material containing an organic compound composed of at least carbon and hydrogen elements such as hydrocarbons, for example, city gas mainly composed of methane, natural gas, LPG or the like. Here, a city gas gas infrastructure line 6 is used as a raw material supply source, and a desulfurization section 5 is connected to the gas infrastructure line 6. The desulfurization part 5 has a shape that can be attached to and detached from the desulfurization connection part 7 disposed on the upstream side and the downstream side. When the adsorption amount of the desulfurization part 5 with respect to the sulfur component is saturated and the adsorption characteristic is lowered, a new desulfurization is performed. It can be exchanged for part 5. The desulfurization section 5 in the present embodiment is filled with a zeolite-based adsorption / removal agent that adsorbs a sulfur compound, which is an odorous component in city gas. Moreover, the desulfurization connection part 7 also has a valve function which controls the distribution | circulation of a raw material, for example, an electromagnetic valve is provided in a structure. In addition, the desulfurization part 5 is good also as a structure using hydrodesulfurization.

The water supply unit 3 has a pump having a flow rate adjusting function. The raw material supply unit 4 is disposed in the raw material supply path 10 that connects the desulfurization unit 5 and the reformer 22, and controls the flow rate of the raw material supplied to the reformer 22, thereby desulfurizing unit from the gas infrastructure line 6. The flow rate of the raw material supplied to 5 is controlled. In addition, the raw material supply part 4 should just be able to control the flow volume of the raw material supplied to the desulfurization part 5, and may be arrange | positioned downstream of the raw material supply part 4. FIG. In the present embodiment, the raw material supply unit 4 has a booster pump, and has a function of adjusting the flow rate of the raw material supplied to the desulfurization unit 5 by controlling, for example, input current pulses, input power, and the like. is doing.

The operation control unit 16 is a control unit that controls the operation of the hydrogen-containing gas in the reformer 22. Here, the supply amount of the raw material supplied from the raw material supply unit 4 to the reformer 22, the water supply unit 3. The amount of water supplied to the reformer 22 is controlled, and the operations of the connection unit 7 and the switching valves 9A and 9B are controlled. Further, the operation of the fuel cell 8 is also controlled (detailed explanation of the operation is omitted). The operation control unit 16 stores the operation information such as the operation sequence of the reformer 22, the raw material integrated flow rate, and the like using a semiconductor memory, a CPU, etc., calculates an appropriate operation condition according to the situation, and The operating conditions are commanded to the configuration necessary for the operation of the supply unit 3 and the raw material supply unit 4.
<Operation of fuel cell system>
Next, the start-up operation of the fuel cell system 100, the operation operation during power generation, and the stop operation will be described focusing on the operation of the hydrogen generator 1.

  When the hydrogen generator 1 is started from the stopped state, the raw material is supplied from the raw material supply unit 4 to the reformer 22 through the raw material supply path 10 according to a command from the operation control unit 16. The raw material that has passed through the steam generation unit 15, the reforming unit 20, the transformation unit 13, and the selective oxidation unit 17 is supplied from the off-gas supply path 14 to the combustion unit 2 via the hydrogen gas supply path 12 and the fuel cell bypass path 23, and burned. It is ignited in the part 2 and heating of the reformer 22 is started.

  After the start of heating in the combustion unit 2, the water supply unit 3 is operated to supply water to the reformer 22, and the reforming reaction between water and the raw material is started. In the present embodiment, city gas (13A) containing methane as a main component is used as a raw material. The amount of water supplied from the water supply unit 3 is controlled so that water vapor is about 3 moles per mole of carbon atoms in the average molecular formula of city gas (S / C is about 3). Further, the air supply unit 19 is operated to supply air to the reformer 22. The amount of air supplied from the air supply unit 19 is controlled so that the amount of oxygen contained in the hydrogen-containing gas is about twice the number of moles of carbon monoxide. In the reformer 22, a steam reforming reaction is progressed in the reforming unit 20, a shift reaction is performed in the shift unit 13, and a selective oxidation reaction of carbon monoxide is advanced in the selective oxidation unit 17. At this time, based on the temperature detected by the reforming temperature detection unit 21, the combustion of the combustion unit 2 is controlled so that the reforming unit 20, the conversion unit 13, and the selective oxidation unit 17 have temperatures suitable for each reaction. To do.

  After the carbon monoxide concentration is reduced to a predetermined concentration (in this embodiment, 20 ppm or less on a dry gas basis), the switching valves 9A and 9B are operated, and the hydrogen-containing gas is supplied to the fuel cell 8 through the hydrogen gas supply path 12. By supplying the fuel cell 8, a power generation operation is performed. Further, the anode offgas discharged from the fuel cell 8 passes through the offgas supply path 14 and is supplied to the combustion unit 2. During the power generation operation, the operation control unit 16 causes the raw material supply unit 4, the water supply unit 3, the air supply unit 19, and the combustion fan 18 so that the temperature detected by the reforming temperature detection unit 21 becomes a predetermined temperature. The raw material supply amount, the water supply amount, the air supply amount, and the combustion air supply amount are controlled by controlling the operation.

When stopping the operation of the fuel cell system 100, the switching valves 9A and 9B are operated according to a command from the operation control unit 16, and the hydrogen-containing gas supplied to the fuel cell 8 is combusted through the fuel cell bypass path 23. Supply to part 2. Thereafter, the operations of the water supply unit 3, the raw material supply unit 4, and the air supply unit 19 are stopped, the supply of water, the raw material, and the air is stopped, and the operation of the hydrogen generator 1 is stopped. The hydrogen generator 1 is stopped by operating the switching valves 9A and 9B to seal the reformer 22, or the amount of the raw material corresponding to the amount of the volume of the reformer 22 that is lowered and the volume is reduced. It is preferable to carry out an operation for preventing contamination of outside air as much as possible in the reformer 22, such as an operation for supplying the air.

  Next, a characteristic operation of the hydrogen generator 1 according to Embodiment 1 of the present invention will be described with reference to FIG. 1 and FIG.

  FIG. 2 is a flowchart schematically showing one cycle of the characteristic operation of the hydrogen generator 1 according to Embodiment 1 of the present invention. In practice, during the power generation operation of the fuel cell system 100, for example, the operation of one cycle shown in FIG. 2 is continuously performed without being intermittent.

Now, when the production | generation of hydrogen containing gas is started in the hydrogen production | generation apparatus 1, the operation control part 16 with which the fuel cell system 100 is provided controls the production amount of hydrogen containing gas so that the change of an electric power load may be tracked. Specifically, the raw material supply amount, the water supply amount, the air supply amount, and the combustion air supply amount are controlled by controlling the operations of the raw material supply unit 4, the water supply unit 3, the air supply unit 19, and the combustion fan 18. An amount of hydrogen-containing gas corresponding to the electric power load is generated, and the temperature detected by the reforming temperature detector 21 is controlled to a predetermined temperature. In contrast to this operation, in the first embodiment, the follow-up control to the change in the power load is stopped (step S1), and the fixed power generation operation is performed at the power load immediately before the follow-up control is stopped. At this time, the operation control part 16 operates the raw material supply part 4, the water supply part 3, the air supply part 19, and the combustion fan 18 with the instruction value preset for every electric power load (step S2). Here, if the operation of each supply unit is normal, each supply amount 1 for each instruction value 1 is equivalent (instruction value 1 = supply amount 1). The metamorphic temperature detected by the shift temperature detection section 24 acquires the metamorphic T _S when the stable (step S3).

Then, the operation control unit 16 is a modified temperature T _S is (higher temperature than a predetermined value than the metamorphic temperature predicted from the indicated value 1) upper temperature limit previously set in the storage unit of the operation control unit 16 T _H or Whether or not (step S4A). Here, the operation control unit 16, when the shift temperature T _S is determined not to be pre-set by the upper limit temperature T _H than in the storage unit of the operation control unit 16 (NO at step S4A), metamorphic T _S is operated It is determined whether or not the temperature is equal to or lower than a lower limit temperature T _L (a temperature that is lower than the transformation temperature expected from each indication value 1 by a predetermined value) set in advance in the storage unit of the control unit 16 (step S4B). Here, the operation control unit 16, when the shift temperature T _S is determined not below the lower limit temperature T _L is previously set in the storage unit of the operation control unit 16 (NO in step S4B), a modified temperature T _S again get.

On the other hand, the operation control unit 16, when the shift temperature T _S is determined to be set in advance as the upper limit temperature T _H than in the storage unit of the operation control unit 16 (YES at step S4A), the raw material supply section 4, the water supply determines that the supply amount 1 is not supplied to at least one of the instruction value 1 of part 3 (indicated value 1 ≠ supply amount 1) is set further metamorphic T _S in advance in the storage unit of the operation control unit 16 It is determined whether the temperature is equal to or higher than an upper limit temperature T _HH (a temperature higher than a predetermined transformation temperature expected from each indication value 1) (step S5A). Here, the operation control unit 16, when the shift temperature T _S is determined to be set in advance as the upper limit temperature T _HH than in the storage unit of the operation control unit 16 (YES at step S5A), it is determined as abnormal, the alarm Is output (step S6). On the other hand, the operation control unit 16, when the shift temperature T _S is determined not to be pre-set by the upper limit temperature T _HH than in the storage unit of the operation control unit 16 (NO at step S5A), an instruction to the raw material supply section 4 The value is decreased, the raw material supply amount is decreased, the instruction value to the water supply unit 3 is increased, and the water supply amount is increased (step S7A). Here, the reduction of the raw material supply amount from the raw material supply unit 4 is executed according to preset reduction data. Similarly, the increase in the amount of water supplied from the water supply unit 3 is also executed according to preset increase data.

Then, the operation control unit 16, the raw material is reduced from the raw material supply section 4 in step S7A, after the water supply from the water supply unit 3 is increased, metamorphic T _S in advance in the storage unit of the operation control unit 16 When it is determined that the temperature is not lower than the set upper limit temperature T _H0 (a temperature higher than the expected transformation temperature from each indicated value 1 by a predetermined value or more) (NO in step S8A), the indicated value to the raw material supply unit 4 is lowered again. The raw material supply amount is decreased, the instruction value to the water supply unit 3 is increased, and the water supply amount is increased (step S7A). On the other hand, if the metamorphic _{T S} is equal to or less than the upper limit temperature _{T H0} set in advance in the storage unit of the operation control unit 16 (YES at step S8A), further, metamorphic _{T S} is stored in the operation control unit 16 It is determined whether or not the temperature is equal to or lower than a lower limit temperature T _LL preset in the section (step S9A). Here, the operation control unit 16, when the shift temperature T _S is equal to or less than the lower limit temperature T _LL previously set in the storage unit of the operation control unit 16 (YES in step S9A), it is determined as abnormal, the alarm Is output (step S10). On the other hand, if the metamorphic T _S is determined not below the lower limit temperature T _LL it is previously set in the storage unit of the operation control unit 16 (NO in step S9A), further, metamorphic T _S is stored in the operation control unit 16 It is determined whether or not the temperature is not less than the lower limit temperature T _{L0 and not} more than the upper limit temperature T _H0 preset in the section (step S11A). Here, the operation control unit 16, when the shift temperature _{T S} is determined not to be the pre-set lower limit temperature _{T L0} or more and the upper limit temperature _{T H0} is less in the storage unit of the operation control unit 16 (NO in step S11A), The instruction value to the raw material supply unit 4 is increased, the raw material supply amount is increased, the instruction value to the water supply unit 3 is decreased, and the water supply amount is decreased (step S13A). Here, the increase in the raw material supply amount from the raw material supply unit 4 is executed according to preset increase data. Similarly, the reduction in the amount of water supplied from the water supply unit 3 is also executed according to preset reduction data. Then, equal to or lower than the upper limit temperature T _H0 is set again metamorphic T _S in advance in the storage unit of the operation control unit 16 (step S8A). On the other hand, if the operation control unit 16 determines that the metamorphic temperature _{T S} is equal to or less than the lower limit temperature _{T L0} or more and the upper limit temperature _{T H0} is preset in the storage unit of the operation control unit 16 (YES in step S11A), the Each instruction value to the raw material supply unit 4 and the water supply unit 3 is set as a new instruction value 1 at the supply amount 1 (new instruction value 1≈supply amount 1) (step S12A).

On the other hand, the operation control unit 16, when the shift temperature T _S is equal to or less than the lower limit temperature T _L to advance is set in the storage unit of the operation control unit 16 (YES at step S4B), a raw material supply section 4, the water supply determines that the supply amount 1 is not supplied to at least one of the instruction value 1 of part 3 (indicated value 1 ≠ supply amount 1) is set further metamorphic T _S in advance in the storage unit of the operation control unit 16 It is determined whether the temperature is lower than the lower limit temperature T _LL (the temperature lower than the transformation temperature expected from each indicated value 1 by a predetermined value or more) (step S5B). Here, the operation control unit 16, when the shift temperature T _S is equal to or less than the lower limit temperature T _LL previously set in the storage unit of the operation control unit 16 (YES at step S5B), it is determined as abnormal, the alarm Is output (step S6). On the other hand, the operation control unit 16, when the shift temperature T _S is not equal to or smaller than the preset is the lower limit temperature T _LL in the storage unit of the operation control unit 16 (NO at step S5B), an instruction to the raw material supply section 4 The value is increased, the raw material supply amount is increased, the instruction value to the water supply unit 3 is decreased, and the water supply amount is decreased (step S7B). Here, the increase in the raw material supply amount from the raw material supply unit 4 is executed according to preset increase data. Similarly, the reduction in the amount of water supplied from the water supply unit 3 is also executed according to preset reduction data.

Then, the operation control unit 16, the raw material is increased from the raw material supply unit 4 at step S7B, after the water supply from the water supply unit 3 is reduced, metamorphic T _S in advance in the storage unit of the operation control unit 16 When it is determined that the temperature is not higher than the set lower limit temperature T _L0 (a temperature that is lower than the expected transformation temperature from each indication value 1 by a predetermined value or more) (NO in step S8B), the indication value to the raw material supply unit 4 is increased again. The raw material supply amount is increased, the instruction value to the water supply unit 3 is decreased, and the water supply amount is decreased (step S7B). On the other hand, if the metamorphic _{T S} is determined to be the lower limit temperature _{T L0} or more in advance is set in the storage unit of the operation control unit 16 (YES at step S8B), further, metamorphic _{T S} is stored in the operation control unit 16 It determines whether the upper limit temperature T _HH or be pre-set to a section (step S9B). Here, the operation control unit 16, when the shift temperature T _S is determined to be set in advance as the upper limit temperature T _HH than in the storage unit of the operation control unit 16 (YES at step S9B), it is determined as abnormal, the alarm Is output (step S10). On the other hand, if the metamorphic T _S is determined not to be pre-set by the upper limit temperature T _HH than in the storage unit of the operation control unit 16 (NO at step S9B), further, metamorphic T _S is stored in the operation control unit 16 It is determined whether the temperature is equal to or higher than a lower limit temperature T _L0 and lower than an upper limit temperature T _H0 set in advance in the section (step S11B). Here, the operation control unit 16, when the shift temperature _{T S} is determined not to be the pre-set lower limit temperature _{T L0} or more and the upper limit temperature _{T H0} is less in the storage unit of the operation control unit 16 (NO in step S11B), The instruction value to the raw material supply unit 4 is lowered, the raw material supply amount is decreased, the instruction value to the water supply unit 3 is increased, and the water supply amount is increased (step S13B). Here, the reduction of the raw material supply amount from the raw material supply unit 4 is executed according to preset reduction data. Similarly, the increase in the amount of water supplied from the water supply unit 3 is also executed according to preset increase data. Then, it is again determined whether or not the transformation temperature T _S is equal to or higher than a lower limit temperature T _L0 preset in the storage unit of the operation control unit 16 (step S8B). On the other hand, if the operation control unit 16 determines that the metamorphic temperature _{T S} is equal to or less than the lower limit temperature _{T L0} or more and the upper limit temperature _{T H0} is preset in the storage unit of the operation control unit 16 (YES in step S11B), the Each instruction value to the raw material supply unit 4 and the water supply unit 3 is set as a new instruction value 1 for the supply amount 1 (new instruction value 1≈supply amount 1) (step S12B).

  Thus, the hydrogen generator 1 according to the present embodiment differs from the operation of the conventional hydrogen generator 1 in that the deviation between the indicated value and the supply amount in the raw material supply unit 4 and the water supply unit 3 is corrected. Yes.

Here, the raw material supply section 4, the water supply unit 3, when the air supply unit 19, the combustion fan 18 is operated at the indicated value 1 becomes higher than the metamorphic temperature metamorphic T _S is expected from the indicated value of 1, Or the reason for becoming low is demonstrated (step S4A, step S4B).

First, metamorphic T _S is higher than the metamorphic temperature expected, or when lower, not supplied to the raw material supply amount feedstock instruction value supplied from the raw material supply section 4, or the water supply unit 3 It is conceivable that the amount of water supplied from is not supplied to the water indication value.

Here, also an air supply amount supplied from the air supply unit 19 is not being supplied to the air indicated value, if the small amount of difference between the air indicated value and the air supply amount, the temperature of the shift temperature T _S Change has little effect. The reaction between air and carbon monoxide in the selective oxidation unit 17 is an exothermic reaction, and the temperature of the selective oxidation unit 17 slightly varies depending on the air supply amount, but the selective oxidation temperature is sufficiently lower than the transformation temperature. It is. When the difference between the air indication value and the air supply amount is large (air indication value> air supply amount), the reaction between air and carbon monoxide is reduced in the selective oxidation unit 17 to remove carbon monoxide. Therefore, the fuel cell 8 is poisoned by carbon monoxide, and the power generation operation cannot be continued. When the difference between the air indication value and the air supply amount is large (air indication value <air supply amount), the reaction between the air and carbon monoxide is an exothermic reaction, so the temperature of the selective oxidation unit 17 is When the temperature rises and exceeds a certain temperature, hydrogen in the hydrogen-containing gas is methanated, and the temperature of the selective oxidation unit 17 is excessively raised. Therefore, also in this case, it is impossible to continue the operation of the hydrogen generator 1 and the power generation operation.

  On the other hand, in the case of the combustion fan 18, it can be confirmed from the relationship between the combustion fan voltage and the combustion fan rotational speed whether or not the combustion fan air supply amount is supplied with respect to the combustion fan air instruction value. . For example, a combustion fan air flow meter may be installed on the upstream side or the downstream side of the combustion fan 18 to check whether the supply amount of the combustion fan air is supplied with respect to the combustion fan air instruction value.

By the way, when the raw material supply unit 4 is operated at the raw material instruction value 1 and the water supply unit 3 is operated at the water instruction value 1, the raw material supply amount is 1, and the water supply amount is smaller than the water supply amount 1. The metamorphic temperature rises. This is because the amount of water supplied to the steam generation unit 15 is reduced, so that heat exchange between the steam generation unit 15 and the shift unit 13 performed via the middle cylinder 25 is suppressed. Moreover, it is because the temperature of the reforming part 20 located upstream of the transformation part 13 rises. This is because the reforming reaction of the raw material and water on the reforming catalyst is an endothermic reaction, and as the S / C is lower, the endothermic reaction does not proceed and the endothermic amount becomes smaller.

  Further, when the raw material supply unit 4 was operated at the raw material instruction value 1 and the water supply unit 3 was operated at the water instruction value 1, the raw material supply amount was larger than the raw material supply amount 1, and the water supply amount was 1. When the transformation temperature rises. This is because the calorific value of the hydrogen-containing gas produced by the increase in the raw material supply amount increases, and the calorific value of the off gas from the fuel cell 8 increases. Moreover, it is because the temperature of the modification | reformation part 20 located upstream of the metamorphic part 13 rises. This is because the reforming reaction of the raw material and water on the reforming catalyst is an endothermic reaction, and as the S / C is lower, the endothermic reaction does not proceed and the endothermic amount becomes smaller.

  Conversely, when the raw material supply unit 4 is operated at the raw material instruction value 1 and the water supply unit 3 is operated at the water instruction value 1, the raw material supply amount is 1 and the water supply amount is larger than the water supply amount 1. The metamorphic temperature decreases. This is because the amount of water supplied to the steam generation unit 15 is increased, and heat exchange between the steam generation unit 15 and the shift unit 13 performed via the middle cylinder 25 is promoted. Moreover, it is because the temperature of the reforming part 20 located upstream of the transformation part 13 falls. This is because the reforming reaction of the raw material and water on the reforming catalyst is an endothermic reaction, and the higher the S / C, the more the endothermic reaction proceeds and the endothermic amount increases.

  Further, when the raw material supply unit 4 was operated at the raw material instruction value 1 and the water supply unit 3 was operated at the water instruction value 1, the raw material supply amount was smaller than the raw material supply amount 1, and the water supply amount was the water supply amount 1. When the metamorphic temperature falls. This is because the calorific value of the hydrogen-containing gas produced by the decrease in the raw material supply amount decreases, and the calorific value of the off gas from the fuel cell 8 decreases. Moreover, it is because the temperature of the reforming part 20 located upstream of the transformation part 13 falls. This is because the reforming reaction of the raw material and water on the reforming catalyst is an endothermic reaction, and the higher the S / C, the more the endothermic reaction proceeds and the endothermic amount increases.

  Here, when the raw material supply unit 4 is operated at the raw material instruction value 1 and the water supply unit 3 is operated at the water instruction value 1, the raw material supply amount is smaller than the raw material supply amount 1, and the water supply amount is smaller than the water supply amount 1. When the amount is small, the transformation temperature does not change significantly compared to when either the raw material supply amount or the water supply amount is small. This is because the calorific value of the hydrogen-containing gas produced by the decrease in the raw material supply amount decreases, and the calorific value of the off gas from the fuel cell 8 decreases, but the water supply amount supplied to the water vapor generating unit 15 decreases. This is because the heat exchange between the steam generation unit 15 and the transformation unit 13 performed via the middle cylinder 25 is suppressed. At the same time, the temperature of the reforming unit 20 located upstream of the transformation unit 13 does not drop greatly. This is because both the raw material supply amount and the water supply amount decrease, and the endothermic amount in the endothermic reaction between the raw material and water on the reforming catalyst becomes small.

  Conversely, when the raw material supply unit 4 is operated at the raw material instruction value 1 and the water supply unit 3 is operated at the water instruction value 1, the raw material supply amount is larger than the raw material supply amount 1, and the water supply amount is larger than the water supply amount 1. When the amount is large, the transformation temperature does not change much compared to when either the raw material supply amount or the water supply amount is large. This is because the calorific value of the hydrogen-containing gas generated by the increase in the raw material supply amount increases and the calorific value of the off gas from the fuel cell 8 increases, but the water supply amount supplied to the water vapor generation unit 15 This is because the heat exchange between the steam generation unit 15 and the transformation unit 13 performed through the middle cylinder 25 is promoted. At the same time, the temperature of the reforming unit 20 located upstream of the transformation unit 13 decreases. This is because both the raw material supply amount and the water supply amount increase, and the endothermic amount in the endothermic reaction between the raw material and water on the reforming catalyst increases.

In the first embodiment, the upper limit _T H of the shift temperature _{T S, T HH, T H0} , the lower limit value _{T L,} T _LL, although a _{T L0,} for example, the raw material supply section 4, the water supply When the unit 3, the air supply unit 19, and the combustion fan 18 are operated at each indicated value 1 and at least one of the indicated values (supply amounts) of the raw material supply unit 4 and the water supply unit 3 is shifted, The amount of hydrogen, the concentration of carbon monoxide, or the raw material instruction that may cause problems such as a reduction in power generation efficiency in the catalysts of the reforming unit 20, the shift unit 13, the selective oxidation unit 17, or the structure of the reformer 22, etc. Values and water instruction values are calculated in advance by experiments, simulations, etc., the raw material supply unit 4 and the water supply unit 3 are the raw material instruction values and water instruction values, and the air supply unit 19 and the combustion fan 18 are the instruction values 1 Set the transformation temperature when the operation is stable and the upper and lower limits. It may be.

Next, the raw material supply section 4, the water supply unit 3, when the air supply unit 19, the combustion fan 18 is operated at the indicated value 1 becomes higher than the metamorphic temperature metamorphic T _S is expected from the indicated value of 1 ( When T _S ≧ T _HH ) or becomes low (T _S ≦ T _LL ), the reason for determining that an abnormality has occurred and outputting an alarm will be described (steps S5A and S5B).

First, the raw material supply section 4, the water supply unit 3, the air supply unit 19, when the combustion fan 18 is operated at the indicated value 1 becomes higher than the metamorphic temperature metamorphic T _S is expected from the indicated value of 1 (T _S ≧ T _HH ), but as described above, a decrease in S / C due to a difference in supply amount with respect to the indicated value of at least one of the raw material supply unit 4 and the water supply unit 3 can be considered. This is because carbon may be deposited on the porous catalyst. On the other hand, the raw material supply section 4, the water supply unit 3, the air supply unit 19, when the combustion fan 18 is operated at the indicated value 1, metamorphic T _S is lower than the metamorphic temperature expected from the indicated value of 1 (T _S ≦ T _LL ), but as described above, an increase in S / C due to a difference in supply amount with respect to the indicated value of at least one of the raw material supply unit 4 and the water supply unit 3 can be considered. This is because the water in the hydrogen-containing gas sometimes condenses and the catalyst may deteriorate.

When the alarm is output, the operation of the fuel cell 8 and the hydrogen generator 1 may be stopped. In addition, the service maintenance company and the fuel cell 8 at the customer's house may be connected online, and the service maintenance company may be notified when an alarm is output. Also, by setting several upper limit values T _HH and lower limit values T _LL for the transformation temperature, if there is a slight abnormality, the service engineer will continue to operate for a period of time until a faulty part is obtained and sent to the customer's home. May be. Of course, safety is ensured because continuous operation is performed after monitoring the abnormality. In addition, although step S5A and step 5B were demonstrated here, step S9A and step 9B are the same reasons.

Next, the raw material supply section 4, the water supply unit 3, the air supply unit 19, when the combustion fan 18 is operated at the indicated value 1, when the shift temperature T _S is higher than the metamorphic temperature predicted from the indicated value 1 The reason why the raw material instruction value is increased and the water instruction value is decreased when the raw material instruction value is decreased and the water instruction value is increased or decreased (steps S7A and S7B) will be described.

First, if the transformer temperature T _S is higher than the metamorphic temperature expected from the indicated value of 1 can be considered downward of the foregoing as S / C. Therefore, by lowering the raw material instruction value and increasing the water instruction value, the S / C is increased, and the S / C is equal to or close to the normal value. At this time, the metamorphic temperature simultaneously decreases. Conversely, if the metamorphic T _S is lower than the metamorphic temperature expected from the indicated value of 1, it is considered elevated foregoing as S / C. Therefore, by increasing the raw material instruction value and lowering the water instruction value, the S / C is lowered, and the S / C is equal to or close to the normal value. At this time, the transformation temperature rises at the same time.

Then, the transformation temperature is set in advance to the amount of hydrogen in the hydrogen-containing gas, the carbon monoxide concentration, each catalyst of the reforming unit 20, the transformation unit 13, the selective oxidation unit 17, the structure of the reformer 22, or the like. The raw material instruction value and the water instruction value when T _L0 ≦ T _S ≦ T _H0 (step S11A, step S11B), which is a transformation temperature range that does not cause a problem with respect to the raw material supply amount 1 and the water supply amount 1, respectively. By newly setting the new raw material instruction value 1 and the fresh water instruction value 1 (step S12A, step S12B), the S / C deviation can be corrected to a value equal to or close to the normal value, and a constant amount. And hydrogen with a low carbon monoxide concentration can be produced. Moreover, carbon deposition on the reforming catalyst and condensation of moisture on the catalyst can be prevented, and failure of the hydrogen generator 1 can be prevented.

  In the first embodiment, the reforming temperature detection unit 21, the selective oxidation unit 17, and the air supply unit 19 are arranged. However, a configuration in which these are not arranged may be used and may be selected as appropriate. Not too long.

  Further, the reforming temperature is not provided in the reforming temperature detection unit 21 or the selective oxidation temperature detection unit that detects the temperature of the selective oxidation unit 17 or the like even in the future when the sensorless configuration is advanced. Based on the transformation temperature detected by the detection unit 24, it is determined whether the raw material supply amount and the water supply amount from the raw material supply unit 4 and the water supply unit 3 are appropriate, the raw material supply amount corresponding to the raw material instruction value, and the water instruction The water supply amount corresponding to the value can be corrected, or it is judged whether the raw material supply amount from the raw material supply unit 4 and the water supply unit 3 is abnormal, and an alarm is output to the outside. Therefore, a certain amount of hydrogen and hydrogen with a low carbon monoxide concentration can be generated. Needless to say, failure of the hydrogen generator can be prevented in advance.

  The present invention determines whether the raw material supply unit, the raw material supply amount supplied from the water supply unit to the hydrogen generator, and the water supply amount are appropriate, and further, the raw material supply amount corresponding to the raw material instruction value or the water instruction The amount of water supply corresponding to the value can be corrected, and a certain amount of hydrogen and hydrogen with a low carbon monoxide concentration can be produced. In addition, it is possible to judge whether the raw material supply amount and water supply amount supplied from the raw material supply unit and water supply unit to the hydrogen generator are abnormal, and an alarm can be output externally, so that the hydrogen generator failure can occur in advance. This is useful for a fuel cell system that can be prevented.

DESCRIPTION OF SYMBOLS 1 Hydrogen generator 2 Combustion part 3 Water supply part 4 Raw material supply part 5 Desulfurization part 6 Gas infrastructure line 7 Desulfurization connection part 8 Fuel cell 9A, 9B Switching valve 10 Raw material supply path 11 Inner cylinder 12 Hydrogen gas supply path 13 Metamorphic part 14 Off-gas path 15 Water vapor generation section 16 Operation control section 17 Selective oxidation section 18 Combustion fan 19 Air supply section 20 Reforming section 21 Reforming temperature detection section 22 Reformer 23 Fuel cell bypass path 24 Transformation temperature detection section 25 Middle cylinder 100 Fuel Battery system

Claims (4)

A reforming unit that is supplied with raw material and water and generates a hydrogen-containing gas by a reforming reaction;
A raw material supply unit that supplies the reforming unit with a raw material according to a raw material supply amount instruction value;
A water supply unit for supplying water according to a water supply amount instruction value to the reforming unit;
A metamorphic section that reduces the concentration of carbon monoxide in the hydrogen-containing gas produced by the reforming section;
A transformation temperature detection unit for detecting the temperature of the transformation unit;
A fuel cell that generates power by supplying the hydrogen-containing gas and the oxygen-containing gas with a reduced carbon monoxide concentration in the metamorphic section, and that generates power following a change in a power load of a power supply destination; and
The remaining hydrogen-containing gas that has not been consumed in the fuel cell among the hydrogen-containing gas whose carbon monoxide concentration has been reduced in the shift section is burned to supply heat necessary for the reforming reaction in the reforming section A combustion section to
An operation control unit that outputs the raw material supply amount instruction value to the raw material supply unit based on the conversion temperature detected by the conversion temperature detection unit and outputs the water supply amount instruction value to the water supply unit;
The operation control unit operates the fuel cell without following the change in the power load for a preset period after generating any power generation amount of the fuel cell,
The raw material supply unit and the water supply unit are operated with a preset instruction value,
An expected transformation temperature expected from the indicated value;
The temperature difference with the detected metamorphic temperature detected by the metamorphic temperature detector is
If it is more than the predetermined temperature difference,
The raw material corresponding to the preset instruction value is not supplied as instructed from the raw material supply unit,
Or
It is determined that the water corresponding to the preset instruction value is not supplied as instructed from the water supply unit, and further, the raw material supply amount corresponding to the raw material instruction value or the water supply corresponding to the water instruction value It has a function to correct the amount,
Or
A fuel cell system with a function to output alarms externally. The operation control unit operates the fuel cell without following the change in the power load for a preset period after generating any power generation amount of the fuel cell,
The raw material supply unit and the water supply unit are operated with a preset instruction value,
From the expected transformation temperature expected from the indicated value,
When the detected transformation temperature detected by the transformation temperature detection unit is higher,
A large amount of raw materials corresponding to preset instruction values are supplied from the raw material supply unit,
Or
When a small amount of water corresponding to the preset instruction value is supplied from the water supply unit,
Or
From the expected transformation temperature expected from the indicated value,
When the detected transformation temperature detected by the transformation temperature detection unit is lower,
The raw material corresponding to the preset instruction value is supplied in a small amount from the raw material supply unit,
Or
When a large amount of water corresponding to the preset instruction value is supplied from the water supply unit,
Judging and further having a function of correcting the raw material supply amount corresponding to the raw material instruction value or the water supply amount corresponding to the water instruction value,
Or
The fuel cell system according to claim 1, which has a function of outputting an alarm externally. The operation control unit operates the fuel cell without following the change in the power load for a preset period after generating any power generation amount of the fuel cell,
The raw material supply unit and the water supply unit are operated with a preset instruction value,
From the expected transformation temperature expected from the indicated value,
When the detected transformation temperature detected by the transformation temperature detection unit is higher,
Decreasing the indicated value to the raw material supply unit and increasing the indicated value to the water supply unit,
Or
From the expected transformation temperature expected from the indicated value,
When the detected transformation temperature detected by the transformation temperature detection unit is lower,
Increase the instruction value to the raw material supply unit, decrease the instruction value to the water supply unit,
The fuel cell system according to claim 1. The operation control unit operates the fuel cell without following the change in the power load for a preset period after generating any power generation amount of the fuel cell,
The raw material supply unit and the water supply unit are operated with a preset instruction value,
From the expected transformation temperature expected from the indicated value,
When the detected transformation temperature detected by the transformation temperature detection unit is higher,
Or
From the expected transformation temperature expected from the indicated value,
When the detected transformation temperature detected by the transformation temperature detection unit is lower,
2. The fuel cell system according to claim 1, wherein the fuel cell system has a function of judging that a raw material supply amount from the raw material supply unit or a water supply amount from the water supply unit is abnormal and outputting an alarm externally.