JP2011210625A - Fuel cell system, and control method of the system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell system and its control method, quickly restarting power generation, even in case an error occurs within the system, while suppressing increase in COemission and deterioration of energy efficiency.SOLUTION: When an error other than an error related to a hydrogen production device 1 is detected, a control unit 20 sets a supply destination of reformed gas to only a burner 10, and continues the operation of at least the hydrogen production device 1, thereby putting the hydrogen production device 1 into a self-sustained operation state. According to this, the hydrogen production device 1 which is not involved in the error is allowed to stand by in the self-sustained operation state without stopping the operation while performing processing for solving the error to a part with the error within the system, and when the system is restarted, the reform gas is rapidly supplied to a cell stack 20 without needing energy or time for start-up.

Description

  The present invention relates to a fuel cell system and a control method for the fuel cell system.

  As a conventional fuel cell system, a reformer that can generate a reformed gas by reforming raw fuel and steam, a hydrogen generator having a burner that heats the reformer, and a reformed gas are used. There is known a fuel cell system including a fuel cell stack that generates electric power (see, for example, Patent Document 1). In this fuel cell system, the battery voltage is monitored, and when the voltage falls below a predetermined value, or when an instantaneous pressure increase or sensor abnormality is detected, a system error is determined and the entire fuel cell system is stopped. It is carried out.

JP 2006-120421 A

As described above, in the conventional fuel cell system, when an error occurs in the system, the operation of the entire system including the hydrogen production apparatus is stopped regardless of the location where the error occurs. When the system was restarted after the error was resolved, it was necessary to restart the hydrogen production apparatus (even if there was no error related to the hydrogen production apparatus). In such a case, energy required for restarting the hydrogen production apparatus is required, and there is a problem that the amount of CO ₂ emission increases and the energy efficiency decreases. Furthermore, there is a problem that when restarting after error elimination, it takes time to generate power again. However, the fuel cell system described above cannot cope with an error that cannot be resolved by restoring the catalytic activity of the air electrode. In such a case, it is necessary to stop the operation of the entire system. is there.

Therefore, the present invention enables fuel to be restarted at an early stage even when an error occurs in the system, and to suppress an increase in CO ₂ emissions and a decrease in energy efficiency. It is an object of the present invention to provide a battery system and a control method for a fuel cell system.

  In order to solve the above problems, a fuel cell system according to the present invention includes a hydrogen production apparatus including a reforming unit that generates a reformed gas containing hydrogen by reforming raw fuel and steam, and a hydrogen production apparatus. A fuel cell system including a fuel cell stack that generates electric power using the generated reformed gas, an operation control means for controlling operation of equipment in the fuel cell system, and an error in the fuel cell system An error detection means and a reformed gas supply destination setting means for setting the supply destination of the reformed gas to a burner or a fuel cell stack, and an error other than an error relating to the hydrogen production apparatus is detected by the error detection means The reforming gas supply destination setting means sets the reforming gas supply destination to the burner only, and the operation control means at least continues the operation of the hydrogen production apparatus. The features.

The fuel cell system according to the present invention includes the reformed gas supply destination setting means that can set the supply destination of the reformed gas to the burner or the fuel cell stack. By returning all of the quality gas to the burner (so-called bypass line), the hydrogen production apparatus can be operated independently. Here, when an error other than an error related to the hydrogen production device is detected by the error detection means, an error has occurred in a part other than the hydrogen production device in the system, so the hydrogen production device itself continues to operate independently. However, it does not affect the processing for error elimination. Therefore, in the present invention, when an error other than an error relating to the hydrogen production apparatus is detected by the error detection means, the reformed gas supply destination setting means sets the reformed gas supply destination only to the burner, and the operation control means. However, at least by continuing the operation of the hydrogen production apparatus, the hydrogen production apparatus can be brought into a self-sustaining operation state. As a result, while processing to eliminate the error is performed for the part where the error has occurred in the system, the hydrogen production apparatus that does not participate in the error is kept in a stand-alone operation state without stopping the operation. Thus, the reformed gas can be promptly supplied to the fuel cell stack without requiring energy or time for starting up when the system is restarted. As described above, even when an error occurs in the system, power generation can be restarted at an early stage, and an increase in CO ₂ emissions and a decrease in energy efficiency can be suppressed.

  Here, when the self-supporting operation in which the entire amount of reformed gas from the hydrogen production apparatus (that is, all of the generated hydrogen) is returned to the burner for a long time, the present inventors In such a case, problems such as burner failure and container deformation may occur, and the amount of combustion air may be excessively increased. I found the possibility of the problem of having to occur. Therefore, as a result of diligent research, the inventors of the present invention have controlled the amount of raw fuel supplied to the reforming unit within an optimal range, and the amount of water vapor relative to the amount of carbon in the raw fuel supplied to the reforming unit. By controlling so that the S / C determined by the molar ratio becomes an optimum value, the above-described problem occurs even if the state in which the total amount of reformed gas from the hydrogen production apparatus is returned to the burner is maintained for a long time. Without making it possible to make the hydrogen production device self-supporting (that is, the thermal balance can be maintained even if all the reformed gas generated in the hydrogen production device is returned to its own burner). I found it. The inventors have further researched, and specifically, the supply amount of the raw fuel supplied to the reforming section is ¼ or less than the supply amount that maximizes the hydrogen production efficiency. It has been found that by controlling and controlling so that S / C becomes 6.0 or more, the hydrogen production apparatus can be surely thermally independent.

  Therefore, in the fuel cell system according to the present invention, raw fuel supply amount control means for controlling the supply amount of raw fuel supplied to the reforming unit, and reforming of the raw fuel supplied to the reforming unit with respect to the amount of carbon. S / C control means for controlling S / C determined by the molar ratio of the amount of steam supplied to the section, and the reformed gas supply destination setting means allows the reformed gas to be supplied only to the burner. When set, the raw fuel supply amount control means controls the raw fuel supply amount to be ¼ or less of the supply amount that maximizes the hydrogen production efficiency, and the S / C control means It is preferable to control so that S / C becomes 6.0 or more. Thus, the reformed gas supply destination setting means sets the reformed gas supply destination to only the burner so that the hydrogen production apparatus is in a self-sustaining operation state, while the raw fuel supply amount control means Is controlled to be ¼ or less of the supply amount that maximizes the hydrogen production efficiency, so that the supply amount of the raw fuel can be made an optimum amount for the independent operation. Furthermore, the S / C control means can control the S / C so as to be 6.0 or more, so that the S / C can be set to an optimum value for the independent operation. As described above, the hydrogen production apparatus can be thermally independent by optimizing the supply amount of raw fuel and the S / C. As a result, it is possible to maintain a state in which the entire amount of reformed gas is supplied to the burner for a long time without causing problems (for example, burner failure or container deformation) associated with the independent operation of the hydrogen production apparatus. . As described above, since the hydrogen production apparatus can be in a self-sustaining operation state for a long time, even if it takes time to eliminate an error, the hydrogen production apparatus is kept in a stand-alone operation state without stopping the operation of the hydrogen production apparatus. be able to.

  Further, in the fuel cell system according to the present invention, the reformed gas supply destination setting means may set the reformed gas supply destination to the fuel cell stack after at least the error detected by the error detection means is resolved. preferable. Thus, by supplying the reformed gas to the fuel cell stack after the detected error is eliminated, power generation can be performed promptly after the error is eliminated.

  In the fuel cell system according to the present invention, the error detecting means repeatedly detects errors other than errors relating to the hydrogen production apparatus after the reformed gas supply destination setting means sets the reformed gas supply destination to only the burner. The operation control means preferably stops the operation of the hydrogen production apparatus when the number of times of error detection by the error detection means exceeds a threshold value. That is, when it takes a predetermined time or more to eliminate an error in the system, the operation of the hydrogen production apparatus in the self-sustaining operation state can be stopped. Accordingly, for example, in a situation where the loss of energy is smaller when the hydrogen production apparatus is stopped than when the independent operation is continued, the hydrogen production apparatus can be stopped.

  In addition, the fuel cell system control method according to the present invention includes a reforming unit that generates reformed gas containing hydrogen by reforming raw fuel and steam, and a hydrogen production that includes a burner that heats the reforming unit. A fuel cell system control method comprising: an apparatus; and a fuel cell stack that generates power using reformed gas generated by a hydrogen production apparatus, an error detection step for detecting an error in the fuel cell system, and an error A reformed gas supply destination setting step for setting the reformed gas supply destination to only the burner of the burner and the fuel cell stack when an error other than an error relating to the hydrogen production device is detected by the detection step; and at least a hydrogen production device And an operation control step for continuing the operation.

According to the control method of the fuel cell system according to the present invention, the reformed gas supply destination setting step can be set such that the reformed gas supply destination is set to only the burner among the burner and the fuel cell stack. By returning all the reformed gas generated in the hydrogen production apparatus to the burner (so-called bypass line), the hydrogen production apparatus can be operated independently. Here, when an error other than an error related to the hydrogen production device is detected in the error detection step, an error has occurred in a part other than the hydrogen production device in the system, so the hydrogen production device itself continues to operate independently. However, it does not affect the processing for error elimination. Therefore, in the present invention, when an error other than an error relating to the hydrogen production apparatus is detected in the error detection step, the reformed gas supply destination is set only to the burner in the reformed gas supply destination setting step, and the operation control is performed. At least the operation of the hydrogen production apparatus is continued in the step, whereby the hydrogen production apparatus can be brought into a self-sustaining operation state. As a result, while processing to eliminate the error is performed for the part where the error has occurred in the system, the hydrogen production apparatus that does not participate in the error is kept in a stand-alone operation state without stopping the operation. Thus, the reformed gas can be promptly supplied to the fuel cell stack without requiring energy or time for starting up when the system is restarted. As described above, even when an error occurs in the system, power generation can be restarted at an early stage, and an increase in CO ₂ emissions and a decrease in energy efficiency can be suppressed.

According to the present invention, even when an error occurs in the system, power generation can be restarted at an early stage, and an increase in CO ₂ emissions and a decrease in energy efficiency can be suppressed.

It is a schematic block diagram which shows a part of fuel cell system which concerns on one Embodiment of this invention. It is a schematic front end view which shows the hydrogen production apparatus of the fuel cell system of FIG. It is a flowchart which shows the content of the control processing by the fuel cell system which concerns on embodiment of this invention. It is a graph which shows the relationship between raw fuel supply amount and hydrogen production efficiency. It is an example of the time chart which shows the change of water supply amount and raw fuel supply amount. It is another example of the time chart which shows the change of water supply amount and raw fuel supply amount. It is a graph for comparing the state of the hydrogen production apparatus when not satisfy | filling the case where the optimal conditions of S / C and raw fuel supply amount which concern on embodiment of this invention are satisfy | filled.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the same or equivalent elements will be denoted by the same reference numerals, and redundant description will be omitted. The terms “upper” and “lower” correspond to the vertical direction of the drawing and are for convenience.

  FIG. 1 is a schematic block diagram showing a part of a fuel cell system according to an embodiment of the present invention. As shown in FIG. 1, a hydrogen production apparatus (FPS: Fuel Processing System) 1 is used as a hydrogen supply source in, for example, a household fuel cell system 100. The hydrogen production apparatus 1 here uses petroleum-based hydrocarbons as a raw fuel, and supplies a reformed gas containing hydrogen to a cell stack (fuel cell stack) 20.

In addition, as raw fuel, you may use alcohol, ethers, biofuel, natural gas, and city gas. Further, as petroleum-based hydrocarbons, naphtha, light oil, etc. can be used as raw fuel in addition to kerosene and LP gas. As the cell stack 20, various types such as a solid polymer type, an alkaline electrolyte type, a phosphoric acid type, a molten carbonate type, or a solid oxide type may be used.

  FIG. 2 is a schematic front end view showing the hydrogen production apparatus of FIG. However, the hydrogen production apparatus 1 is an example, and a different configuration may be adopted. As shown in FIGS. 1 and 2, the hydrogen production apparatus 1 includes a desulfurization part 2 having a cylindrical outer shape with a central axis as an axis G, and a main body part 3 with a cylindrical outer shape having a central axis as an axis G. These are accommodated in the housing 4. Further, in the casing 4, the surroundings of the desulfurization part 2 and the main body part 3 are filled with a powdery heat insulating material (not shown) to be insulated. The desulfurization part 2 may be installed outside the housing | casing 4, and does not need to be provided.

  The desulfurization unit 2 desulfurizes the raw fuel introduced from the outside with a desulfurization catalyst to remove sulfur, and supplies the raw fuel to a feed unit 5 described later. The desulfurization part 2 is fixed to the side plate 4x of the housing 4 with a pipe, and is held so as to surround the upper part of the main body part 3 with a predetermined gap. The main body 3 includes a feed unit 5, a reforming unit 6, a shift reaction unit 7, a selective oxidation reaction unit 8, and an evaporation unit 9, which are integrally configured. The main body 3 is fixed and held on a floor plate 4y of the housing 4 by a cylindrical stay.

  The feed unit 5 mixes the raw fuel and steam (steam) desulfurized in the desulfurization unit 2 and supplies them to the reforming unit 6. Specifically, the feed unit 5 includes a mixing unit 5x that combines and mixes raw fuel and water vapor to generate a mixed gas (mixed fluid), and a mixed gas channel 5y that distributes the mixed gas to the reforming unit 6. , Including.

  A reforming section (SR: Steam Reforming) 6 generates a reformed gas by steam reforming the mixed gas supplied from the feed section 5 with the reforming catalyst 6x, and supplies the reformed gas to the shift reaction section 7. To do. The reforming part 6 has a cylindrical outer shape with the central axis as the axis G, and is provided on the upper end side of the main body part 3 so as to be located in the cylinder of the desulfurization part 2. In this reforming section 6, since the steam reforming reaction requires a high temperature and is an endothermic reaction, the burner 10 is used as a heat source for heating the reforming catalyst 6x of the reforming section 6.

  In the burner 10, raw fuel is supplied from outside as burner fuel and burned at the time of startup. The burner 10 is attached to a combustion cylinder 11 provided at the upper end of the main body 3 and having the axis G as a central axis so that a flame by the burner 10 is surrounded. In the burner 10, a part of the raw fuel desulfurized in the desulfurization unit 2 may be supplied as burner fuel and burned.

  The shift reaction unit 7 is for lowering the carbon monoxide concentration (CO concentration) of the reformed gas supplied from the reforming unit 6, and shifts the carbon monoxide in the reformed gas to generate hydrogen and Convert to carbon dioxide. Here, the shift reaction unit 7 can perform the shift reaction in two stages, and performs a high temperature shift reaction that is a shift reaction at a high temperature (for example, 400 ° C. to 600 ° C.). (HTS: High Temperature Shift) 12 and a low temperature shift reaction part (LTS: Low Temperature Shift) 13 that performs a low temperature shift reaction that is a shift reaction at a temperature lower than the temperature of the high temperature shift reaction (for example, 150 ° C. to 350 ° C.). And have. However, the high temperature shift reaction unit 12 is not necessarily provided.

  The high temperature shift reaction unit 12 causes the carbon monoxide in the reformed gas supplied from the reforming unit 6 to undergo a high temperature shift reaction with the high temperature shift catalyst 12x, thereby reducing the CO concentration of the reformed gas. The high temperature shift reaction unit 12 has a cylindrical outer shape with the central axis as the axis G, and is disposed adjacent to the radially outer side of the reforming unit 6 so that the high temperature shift catalyst 12x surrounds the lower end of the reforming catalyst 6x. ing. The high temperature shift reaction unit 12 supplies the reformed gas having a reduced CO concentration to the low temperature shift reaction unit 13.

  The low temperature shift reaction unit 13 causes the carbon monoxide in the reformed gas subjected to the high temperature shift reaction in the high temperature shift reaction unit 12 to undergo a low temperature shift reaction by the low temperature shift catalyst 13x, thereby reducing the CO concentration of the reformed gas. The low temperature shift reaction part 13 has a cylindrical outer shape with the central axis as the axis G, and is disposed on the lower end side of the main body part 3. The low temperature shift reaction unit 13 supplies the reformed gas having a reduced CO concentration to the selective oxidation reaction unit 8 via the reformed gas pipe 14x.

  A selective oxidation reaction unit (PROX) 8 further reduces the CO concentration in the reformed gas subjected to the low temperature shift reaction in the low temperature shift reaction unit 13. This is because if a high concentration of carbon monoxide is supplied to the cell stack 20, the catalyst of the cell stack 20 is poisoned and the performance is greatly reduced. Specifically, the selective oxidation reaction section 8 reacts carbon monoxide in the reformed gas with air introduced through the air pipe 15 by the selective oxidation catalyst 8x, thereby converting hydrogen in the reformed gas. Without oxidizing, carbon monoxide is selectively oxidized and converted to carbon dioxide. The selective oxidation reaction portion 8 has a cylindrical outer shape with the central axis as the axis G, and is disposed so as to constitute the outermost peripheral side of the main body portion 3 from the lower end of the main body portion 3 to the upper end side of a predetermined length. .

  The selective oxidation reaction unit 8 guides the reformed gas whose CO concentration is further reduced to the outside through the reformed gas pipe 14 y provided with the heat exchange unit 16. The heat exchanging unit 16 exchanges heat between the reformed gas flowing through the reformed gas pipe 14y and the water introduced from the outside through the water pipe 17x, and supplies the water to the evaporator 9 Supply via the pipe 17y.

  The evaporation unit 9 stores the water supplied from the heat exchange unit 16 and moves the water from the heat from the exhaust gas from the burner 10, the low temperature shift reaction unit 13 and the selective oxidation reaction unit 8 (low temperature shift). It is vaporized with heat (obtained by cooling the reaction section 13 and the selective oxidation reaction section 8) to generate water vapor. The evaporator 9 is of a jacket type and has a cylindrical shape with the central axis as the axis G. The evaporation unit 9 is located radially outside the high temperature shift reaction unit 12 and the low temperature shift reaction unit 13 and inside the selective oxidation reaction unit 8 (that is, between the shift reaction unit 7 and the selective oxidation reaction unit 8). It is arranged to be located. The evaporation unit 9 supplies the generated water vapor to the mixing unit 5x of the feed unit 5 via the water vapor pipe 17z.

  In such a hydrogen production apparatus 1, first, at least one of burner fuel and off-gas from the cell stack 20 (residual gas not used for reaction in the cell stack 20) and air are supplied to the burner 10 and burned, and such combustion is performed. As a result, the reforming catalyst 6x is heated. And the exhaust gas of the burner 10 distribute | circulates an exhaust gas flow path and the gas piping 18, and is exhausted outside.

  At the same time, the raw fuel desulfurized in the desulfurization unit 2 and the water vapor from the evaporation unit 9 are mixed in the mixing unit 5x to generate a mixed gas. The mixed gas is supplied to the reforming unit 6 through the mixed gas flow path 5y and is steam reformed by the reforming catalyst 6x, thereby generating a reformed gas. Then, after the generated reformed gas has its carbon monoxide concentration lowered to, for example, about several thousand ppm by the shift reaction section 7, and after its carbon monoxide concentration has been lowered to about 10 ppm or less by the selective oxidation reaction section 8. Then, it is cooled by the heat exchange unit 16 and led out to the cell stack 20 at the subsequent stage.

  In the present embodiment, for example, the temperature of each part is set as follows in order to suitably perform the catalytic reaction with each of the catalysts 6x, 12x, 13x, and 8x. That is, the temperature of the mixed gas flowing into the reforming unit 6 is about 300 to 550 ° C., the temperature of the reformed gas flowing out of the reforming unit 6 is 550 to 800 ° C., and flows into the high temperature shift reaction unit 12 The temperature of the reformed gas is 400 to 600 ° C., and the temperature of the reformed gas flowing out from the high temperature shift reaction unit 12 is 300 to 500 ° C. Further, the temperature of the reformed gas flowing into the low temperature shift reaction unit 13 is set to 150 ° C. to 350 ° C., and the temperature of the reformed gas flowing out from the low temperature shift reaction unit 13 is set to 150 ° C. to 250 ° C. The temperature of the reformed gas flowing into 8 is 90 ° C. to 210 ° C. (120 ° C. to 190 ° C.).

  Here, the fuel cell system 100 according to the present embodiment includes a bypass line L1 for returning the reformed gas generated in the hydrogen production apparatus 1 to the burner 10, a condensate recovery device 40 attached to the bypass line L1, and a reforming. And a stack line L <b> 2 for supplying gas to the cell stack 20. In the normal operation, the fuel cell system 100 supplies the reformed gas to the cell stack 20 by supplying the reformed gas to the stack line L2, and when an error other than the error related to the hydrogen production apparatus 1 occurs, the reformed gas is bypassed. By supplying only to L1, the entire amount of the reformed gas is supplied to the burner 10, and when the error is solved, the reformed gas is supplied to the stack line L2 again to be supplied to the cell stack 20. When the reformed gas is supplied only to the bypass line L1, all of the reformed gas generated in the hydrogen production apparatus 1 is returned to the hydrogen production apparatus 1, so that the hydrogen production apparatus 1 is in a self-supporting state (the following) In the description, such a state will be referred to as a self-sustaining operation state). Moreover, when the water | moisture content in the reformed gas which distribute | circulates the bypass line L1 is condensed, it is discharged | emitted by the condensed water collection | recovery apparatus 40 to the water tank etc. in a system, and is utilized again as raw material water. The fuel cell system 100 according to the present embodiment performs control so that the operation of the hydrogen production apparatus 1 is continued in the self-sustaining operation state when an error other than the error related to the hydrogen production apparatus 1 occurs in the system. The hydrogen production apparatus 1 has a function of controlling so that the self-sustaining operation state can be maintained for a long time. In order to realize such a function, the fuel cell system 100 includes a raw fuel supply pump 110, a water supply pump 120, a burner fuel supply pump 130, a burner air supply pump 140, a selective oxidation air supply pump 150, a flame state detection sensor. 160, a bypass valve 170, a stack side valve 180, an error detection sensor CE, and a control unit 200. In the figure, the electrical connection relationship is omitted. The flame state detection sensor 160 is not an essential element and may not be provided.

  The raw fuel supply pump (raw fuel supply amount control means, S / C control means) 110 is a pump for supplying raw fuel to the reforming unit 6. The water supply pump (S / C control means) 120 is a pump that supplies water to the reforming unit 6 through the water pipe 17 x and the evaporation unit 9. The burner fuel supply pump 130 is a pump that supplies burner fuel to the burner 10. The burner air supply pump 140 is a pump that supplies air to the burner 10. The selective oxidation air supply pump 150 is a pump that supplies selective oxidation air to the selective oxidation reaction unit 8. Each pump is electrically connected to the control unit 200 and is driven based on a control signal input from the control unit 200. In addition, arrangement | positioning of each pump is not limited to the position shown in FIG.1 and FIG.2.

  The bypass valve (reformed gas supply destination setting means) 170 has a function of opening and closing the flow path of the bypass line L1. The stack side valve (reformed gas supply destination setting means) 180 has a function of opening and closing the flow path of the stack line L2. The bypass valve 170 and the stack side valve 180 are electrically connected to the control unit 200 and open and close based on a control signal input from the control unit 200. When the bypass valve 170 is closed and the stack side valve 180 is open, the reformed gas from the hydrogen production apparatus 1 flows only through the stack line L2 and is supplied only to the cell stack 20. On the other hand, when the bypass valve 170 is opened and the stack side valve 180 is closed, the reformed gas from the hydrogen production apparatus 1 flows only through the bypass line L1 and is supplied only to the burner 10. However, the reformed gas can be supplied to both the burner 10 and the cell stack 20 by adjusting the degree of opening and closing of each valve.

  The error detection sensor (error detection means) CE can detect an error in the fuel cell system 100, and is configured by various sensors installed at arbitrary locations in the fuel cell system 100. The error detection sensor is electrically connected to the control unit 200 and has a function of outputting a detection result to the control unit 200. As an error in the fuel cell system 100, for example, the power generation state in the fuel cell stack 20 becomes unstable, the voltage in the fuel cell stack 20 is too low, or an abnormal value of the instantaneous control sensor is detected. And detecting an instantaneous communication abnormality. The error detection sensor CE can also detect an error relating to the hydrogen production apparatus 1. Examples of the error related to the hydrogen production apparatus 1 include that the catalyst temperature is out of the proper range and the pressure is out of the proper range.

  The condensed water recovery device 40 has a function of recovering moisture contained in the reformed gas flowing through the bypass line L1 and discharging it out of the system. By collecting moisture with the condensed water collection device 40, it is possible to prevent moisture from entering the burner 10 after the process water is supplied to the reforming unit 6. Specifically, the condensed water recovery apparatus 40 includes a heat exchanger 40A and a drain recovery device 40B. The heat exchanger 40A heat-exchanges the reformed gas and a predetermined fluid to cool the reformed gas and convert the water vapor into water (liquid). The predetermined fluid for heat exchange is, for example, hot water recovery water. The drain collector 40B collects the condensed water and is discharged to a water tank or the like in the system and used again as raw water. Note that it is sufficient that the reformed gas is cooled and moisture can be removed by the drain collector 40B, and the heat exchanger 40A may not be provided.

  The control unit (operation control means, error detection means, reformed gas supply destination setting means, raw fuel supply amount control means, S / C control means) 200 functions to control the fuel cell system 100 and the hydrogen production apparatus 1 as a whole. For example, a device that performs electronic control (for example, a device including a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and an input / output interface). ing. The control unit 200 can control the operation of all the devices in the fuel cell system 100, and is electrically connected to each device in the hydrogen production apparatus 1, the cell stack 20, or a device (not shown). Control can be performed. The control unit 200 sets the supply amount in each of the raw fuel supply pump 110, the water supply pump 120, the burner fuel supply pump 130, the burner air supply pump 140, and the selective oxidation air supply pump 150, and the supply amount is As a result, it has a function of outputting a control signal to each pump. The control unit 200 can set the supply destination of the reformed gas to the burner 10 or the cell stack 20 by outputting control signals to the bypass valve 170 and the stack side valve 180. The control unit 200 can set the supply destination of the reformed gas only to the burner 10 when an error other than the error related to the hydrogen production apparatus 1 occurs, and reforming during normal operation in which no error occurs. The gas supply destination can be set in the cell stack 20. Further, the control unit 200 can detect the occurrence of an error in the system based on the detection result from the error detection sensor CE. Furthermore, the control unit 200 can specify the content of the detected error and determine whether the error is an error relating to the hydrogen production apparatus 1. In addition, the control unit 200 can monitor the elimination of the error by repeatedly acquiring the signal from the error detection unit and continuously detecting the error after detecting the error once. After detecting a specific error, the control unit 200 can count the number of times the error has been detected.

  Further, the control unit 200 can control the supply amount of the raw fuel supplied to the reforming unit 6 to an appropriate supply amount so that the hydrogen production apparatus 1 can perform a self-sustaining operation for a long time. In addition, the control unit 200 can control the S / C to an appropriate S / C so that the hydrogen production apparatus 1 can perform a self-sustained operation for a long time, and perform power generation in the cell stack 20 from the self-sustained operation state. It is also possible to change the S / C to an appropriate value. Here, S / C is a molar ratio of water vapor supplied to the reforming unit 6 with respect to carbon in the raw fuel supplied to the reforming unit 6. Moreover, the control part 200 can control the burner air ratio with respect to the burner 10 to an appropriate value. The burner air ratio is the ratio of the amount of air supplied to the burner 10 to the amount of air (theoretical air amount) that can completely burn all the fuel supplied to the burner 10. In the self-sustaining operation state of the hydrogen production apparatus 1, the reformer gas is supplied to the burner 10 as a fuel. Therefore, the burner air ratio is the air that can completely burn the combustible gas in the reformed gas by the hydrogen production apparatus 1. It is defined by the ratio of the amount of air by the burner air supply pump 140 to the amount. On the other hand, when the burner 10 is operated with burner fuel, the burner air ratio is the ratio of the amount of air by the burner air supply pump 140 to the amount of air that can completely burn all the burner fuel supplied by the burner fuel supply pump 130. Defined.

  Next, control processing by the fuel cell system 100 according to the present embodiment will be described with reference to FIGS. 3, 4, 5, and 6. FIG. 3 is a flowchart showing the contents of the control process when the hydrogen production apparatus 1 is started by the fuel cell system 100. FIG. 4 is a graph showing the relationship between the raw fuel supply amount and the hydrogen production efficiency. FIG. 5 is an example of a time chart showing changes in the water supply amount and the raw fuel supply amount. FIG. 6 is another example of a time chart showing changes in the water supply amount and the raw fuel supply amount. The control process shown in FIG. 3 is repeatedly executed at a predetermined timing in the control unit 200.

  The control processing shown in FIG. 3 is control when a predetermined error in the system is detected during operation of the fuel cell system 100. In this control process, when the detected error is something other than an error related to the hydrogen production apparatus 1, the hydrogen production apparatus 1 is put into a self-sustaining operation state, and when the system operation is started again at an early stage. While being able to perform electric power generation, the fall of energy efficiency can be suppressed. This process is executed at a timing when the error detection sensor CE detects some error. As shown in FIG. 3, the controller 200 detects an error that has occurred in the fuel cell system 100 based on the detection result of the error detection sensor CE (step S10: error detection step). Next, the control unit 200 determines whether or not the error detected in S10 is an error related to the hydrogen production apparatus 1 (step S20). If it is determined in S20 that the error is an error related to the hydrogen production apparatus 1, the control unit 200 stops the operation of the hydrogen production apparatus 1 and other devices in the system (step S160), and eliminates the error. Execute control processing. When S160 is executed, the control process shown in FIG. 3 is terminated, and when an error is detected next time, the process is started again from S10.

  On the other hand, when it is determined in S20 that the detected error is not an error relating to the hydrogen production apparatus, the control unit 200 opens the bypass valve 170 and closes the stack side valve 180, thereby reforming gas. Is set to the burner 10 only (step S30: reformed gas supply destination setting step). As a result, the entire amount of the reformed gas generated in the hydrogen production apparatus 1 flows through the bypass line L1 and is supplied to the burner 10. That is, the hydrogen production apparatus 1 shifts to the self-sustaining operation state. Next, the control unit 200 continues the operation of at least the hydrogen production apparatus 1 and stops the operation of the equipment related to the error (step S40: operation control step). Next, the control unit 200 controls the burner air supply pump 140 to change the amount of burner air supplied to the burner 10 (step S50). At this time, the control unit 200 performs control so that the burner air ratio becomes an optimum value for performing the independent operation. Specifically, the control unit 200 performs control so that the burner air ratio is 1.1 or more and 2.5 or less.

  Next, the control unit 200 changes the amount of water supplied to the reforming unit 6 by controlling the water supply pump 120. (Step S60: S / C control step). Further, the control unit 200 changes the raw fuel supply amount to the reforming unit 6 by controlling the raw fuel supply pump 110 (step S70: raw fuel supply amount control step, S / C control step). At this time, the control unit 200 sets an optimal supply amount of raw fuel and an optimal S / C so as to be an appropriate supply amount in order to maintain the self-sustaining operation state, and becomes the set value. Thus, the raw fuel supply pump 110 and the water supply pump 120 are controlled. Here, the control unit 200 sets a raw fuel supply amount that is ¼ or less of a supply amount at which hydrogen production efficiency is maximized as an optimal raw fuel supply amount for maintaining the self-sustaining operation state. Can do. As shown in FIG. 4, the hydrogen production efficiency (reforming process efficiency) of the hydrogen production apparatus 1 increases as the raw fuel supply amount increases, and reaches a maximum value when the raw fuel supply amount reaches a predetermined amount. However, if the supply of raw fuel is further increased, it will go down. The raw fuel supply amount that maximizes the hydrogen production efficiency is indicated by P1 in FIG. 4. In the following description, the raw fuel supply amount at this time is referred to as the maximum efficiency supply amount P1. In S70, the control unit 200 sets a value that is equal to or less than ¼ of the maximum efficiency supply amount P1 as the raw fuel supply amount (raw fuel supply amount within a range indicated by FV in FIG. 4). If the supply amount of raw fuel is too small, the reforming catalyst temperature becomes too lower than the predetermined temperature due to insufficient heat, so the lower limit of the supply amount of raw fuel is set to 1/20 or more with respect to the maximum efficiency supply amount P1. Is preferred. The control unit 200 sets a value of 6.0 or more as S / C and controls the raw fuel supply pump 110 so that the value is obtained. The water supply pump 120 may be controlled as necessary so that the set S / C is obtained. In addition, since it will become impossible to evaporate water completely by the evaporation part 9 in the hydrogen production apparatus 1 if there is too much water supply amount, it is preferable to set it as 20 or less as an upper limit of S / C. As a result, the hydrogen production apparatus 1 can be thermally independent and can maintain the autonomous operation state for a long time until the error is resolved. At this time, a control method of adjusting the raw fuel supply amount so that the reforming catalyst temperature becomes a predetermined temperature may be employed. Further, the supply amount of the selective oxidation air may be changed in the self-sustaining operation state.

  After the hydrogen production apparatus 1 enters the self-sustaining operation state, the control unit 200 again detects an error for the same content as that detected in S10 based on the detection result from the error detection sensor CE (step S80). ) Next, the control unit 200 determines whether or not a predetermined condition is satisfied based on the detection result in S80 (step S90), whereby the error is resolved and the fuel cell system 100 can be started again. Judge whether or not. Here, as predetermined conditions, all the current errors in the fuel cell system 100 have not occurred, the time after the occurrence of the error is longer than a predetermined time, or no error has occurred It can be determined that the time is over a predetermined time.

  If it is determined in S90 that the condition is not satisfied, the fuel cell system 100 is in a state where it cannot be restarted. At this time, the control unit 200 increases the counter of the number of times of error detection by one, and determines whether or not the count number of the error detection is equal to or greater than a predetermined threshold (step S150). When it is determined in S150 that the error detection count is equal to or greater than the threshold, the control unit 200 stops the operation of the hydrogen production apparatus 1 and other devices in the system (step S160). The hydrogen production apparatus 1 is in a state of stopping operation and waiting until the error is resolved. When S160 is executed, the control process shown in FIG. 3 is terminated, and when an error is detected next time, the process is started again from S10. On the other hand, if it is determined in S150 that the error detection count is smaller than the threshold value, the process proceeds to S80 again to repeatedly detect errors.

  When it determines with satisfy | filling conditions in S90, the control part 200 transfers to a power generation preparation state from a self-sustained operation state. The power generation preparation state is a preparation stage for shifting to a power generation start state in which power generation can be performed by supplying reformed gas to the cell stack 20. In addition, since the whole amount of reformed gas is supplied to the burner 10 even in the power generation preparation state, the self-sustaining operation state is substantially continued. Specifically, the control unit 200 changes the water supply amount by the water supply pump 120 so as to obtain an optimal raw fuel supply amount and an optimal S / C for efficient power generation (step S100), The raw fuel supply amount by the raw fuel supply pump 110 is changed (step S110). Note that the burner air ratio may be changed to a value during normal operation at this timing. Further, the supply amount of the selective oxidation air may be changed. At this time, the control unit 200 increases the water supply amount and the raw fuel supply amount, but lowers the S / C by greatly increasing the raw fuel supply amount compared to the water supply amount. Further, when increasing the supply amount of the raw fuel, the control unit 200 may increase it in a slope shape as shown in FIG. 5, or may increase it stepwise in a step shape as shown in FIG. The control unit 200 sets a plurality of target values before setting the final raw fuel supply amount and S / C target value, gradually increases the raw fuel supply amount, and gradually increases S / C is lowered. The final S / C, that is, the S / C in a power generation start state in which power generation can be started in the cell stack 20, is preferably set to 4.5 or less. Thereby, the certainty at the time of generating electric power with the cell stack 20 improves. The final raw fuel supply amount is not particularly limited, but can be a raw fuel supply amount that can secure a hydrogen generation amount corresponding to the minimum power generation amount of the cell stack 20, for example.

  In S100 and S110, when the raw fuel supply amount and S / C reach the target values, the raw fuel supply amount by the raw fuel supply pump 110 and the water supply amount by the water supply pump 120 are made constant, thereby making the cell stack 20 It shifts to the power generation start state for performing power generation at. When shifting to the power generation start state, the control unit 200 resumes the operation of the stopped device (step S120). Further, the control unit 200 sets the supply destination of the reformed gas to the cell stack 20 by opening the stack side valve 180 (step S130) and closing the bypass valve 170 (step S140). As a result, the operation of the entire fuel cell system 100 is resumed, and power generation is performed in the cell stack 20. When the process of S140 is finished, the process shown in FIG. 3 is finished, and when an error is detected next, the process is started again from S10.

  Referring to FIGS. 5 and 6, how the water supply amount and the raw fuel supply amount change after the processing of S <b> 60 and S <b> 70 in FIG. 3 is completed until the power generation is restarted by the processing of S <b> 130 and S <b> 140. Will be explained. First, in the self-sustaining operation state, after the change of the water supply amount and the raw fuel supply amount is completed in S60 and S70, the water supply amount is kept constant, and the raw fuel supply amount is ¼ or less of the maximum efficiency supply amount. The supply amount is maintained constant. Thereby, S / C is also maintained at 6.0 or more, and it is possible to stably maintain the autonomous operation state. In this state, the processes of S80, S90, and S150 are repeated. Next, the process of changing the water supply amount and raw fuel supply amount in S100 and S110 is performed at the timing of time t1. That is, the self-sustained operation state shifts to the power generation preparation state at the timing of time t1. In the power generation preparation state after time t1, the water supply amount and the raw fuel supply amount increase in a slope shape so as to form a plurality of steps as shown in FIG. As a result, since the raw fuel supply amount can be gradually increased in a slope shape without sudden increase, reforming in the hydrogen production apparatus 1 can be performed stably and reforming in a state where hydrogen generation is stable. Gas can be supplied to the cell stack 20. The rate of increase in the amount of raw fuel supply is greater than the amount of water supply. Alternatively, as shown in FIG. 6, the water supply amount increases to the target supply amount at the time t1, and the raw fuel supply amount increases stepwise so as to form a plurality of steps. As a result, since the supply amount of raw fuel can be increased stepwise in a stepwise manner, reforming in the hydrogen production apparatus 1 can be performed stably, and the hydrogen generation can be improved in a stable state. A quality gas can be supplied to the cell stack 20. At time t2, the raw fuel supply amount becomes the target supply amount, and the S / C becomes a target value. After that, the water supply amount and the raw fuel supply amount are kept constant. The power generation preparation state is shifted to the power generation start state at the timing of time t2. In addition, after shifting to the power generation start state, the process of changing the reformed gas supply destination of S130 and S140 to the cell stack may be performed promptly. Also good. Note that there is no particular limitation on the number of steps in which the slope-shaped increase in FIG. 5 is performed and the number of steps in the step-shaped increase in FIG. 6 are performed.

  Next, operations and effects of the fuel cell system 100 according to the present embodiment will be described.

According to the fuel cell system 100 according to the present embodiment, since the control unit 200 can set the supply destination of the reformed gas to the burner 10 or the cell stack 20, the reformed gas generated in the hydrogen production apparatus 1 By returning all of the above to the burner 10 using the bypass line L1, the hydrogen production apparatus 1 can be operated independently. Here, the case where an error other than an error relating to the hydrogen production apparatus 1 is detected means that an error has occurred in a part other than the hydrogen production apparatus 1 in the system, and thus the hydrogen production apparatus 1 itself continues the autonomous operation. However, it does not affect the processing for error elimination. Therefore, in the present embodiment, when an error other than an error related to the hydrogen production apparatus 1 is detected, the control unit 200 sets the supply destination of the reformed gas only to the burner 10 and at least the operation of the hydrogen production apparatus 1. By continuing the above, the hydrogen production apparatus 1 can be brought into a self-sustaining operation state. As a result, for the part where the error has occurred in the system, while performing the process for eliminating the error, the hydrogen production apparatus 1 that does not participate in the error is set in the self-sustaining operation state without stopping the operation. When the system is restarted, the reformed gas can be supplied to the cell stack 20 promptly without requiring energy or time for starting. As described above, even when an error occurs in the system, power generation can be restarted at an early stage, and an increase in CO ₂ emissions and a decrease in energy efficiency can be suppressed.

  Further, in the fuel cell system 100 according to the present embodiment, when the reformed gas supply destination is set only to the burner 10, the control unit 200 is configured such that the raw fuel supply amount is less than the maximum efficiency supply amount P1. It can be controlled to be 4 or less and S / C can be controlled to be 6.0 or more. As a result, by setting the supply destination of the reformed gas only to the burner 10, the hydrogen production apparatus 1 is set in the self-sustaining operation state, while the control unit 200 has a raw fuel supply amount of 1 relative to the maximum efficiency supply amount P1. By controlling so as to be equal to or less than / 4, the supply amount of the raw fuel can be made an optimum amount for the independent operation. Furthermore, the control part 200 can make S / C into the optimal value for a self-sustained operation by controlling so that S / C may be 6.0 or more. As described above, the hydrogen production apparatus 1 can be thermally independent by optimizing the raw fuel supply amount and the S / C. As a result, it is possible to maintain the state in which the entire amount of reformed gas is supplied to the burner 10 for a long time without causing problems (for example, burner failure or container deformation) associated with the self-sustaining operation of the hydrogen production apparatus 1. It becomes. As described above, since the hydrogen production apparatus 1 can be in a self-sustaining operation state for a long time, even if it takes time to eliminate an error, the hydrogen production apparatus 1 is kept in an independent operation state without stopping the operation of the hydrogen production apparatus 1. Can wait.

  Here, FIG. 7 is used to compare the case where the raw fuel supply amount and the S / C satisfy the optimum condition for performing the autonomous operation and the case where the optimum condition is not satisfied. However, in the present invention, it is possible to perform the control under conditions that do not satisfy the optimum conditions, and it will be explained that the autonomous operation state can be maintained for a longer time by performing the optimum conditions described here. In the lower part of FIG. 7, a time chart showing changes in the raw fuel supply amount and the water supply amount supplied to the reforming unit 6 is shown. Note that SL1 in the graph is a reference line indicating a supply amount of 1/4 with respect to the maximum efficiency supply amount P1. In the upper part of FIG. 7, a time chart showing the temperature change in each part of the hydrogen production apparatus 1 is shown. Specifically, the flame temperature of the burner 10, the outlet temperature of the reforming unit 6, the catalyst temperature of the low temperature shift reaction unit 13, and the catalyst temperature of the selective oxidation reaction unit 8 are shown. SL2, SL3, SL4, and SL5 in the graph indicate reference temperatures of the outlet temperature of the reforming unit 6, the catalyst temperature of the low temperature shift reaction unit 13, and the catalyst temperature of the selective oxidation reaction unit 8, respectively. If the temperature lower than the reference temperature can be continuously maintained, the hydrogen production apparatus 1 can be stably operated independently. As shown in FIG. 7, the raw fuel supply amount is ¼ or less of the maximum efficiency supply amount P1 between times t10 and t11, and the water supply amount also satisfies S / C> 6.0. It is maintained at the supply amount that satisfies. Thus, in the state where the conditions according to the present embodiment are satisfied, the flame temperature of the burner 10, the outlet temperature of the reforming unit 6, the catalyst temperature of the low temperature shift reaction unit 13, and the catalyst temperature of the selective oxidation reaction unit 8 are any Is maintained at a temperature lower than the reference temperatures SL2, SL3, SL4, and SL5. Therefore, by setting the raw fuel supply amount to ¼ or less of the maximum efficiency supply amount P1 and S / C to 6.0 or more, the temperature of each part of the hydrogen production apparatus 1 is balanced to an appropriate temperature. It is understood that stable and stable operation is possible.

  On the other hand, the water supply pump 120 was controlled so that the S / C became a value lower than 6.0 by reducing the water supply amount at times t11 to t12. At this time, the flame temperature of the burner 10, the outlet temperature of the reforming unit 6, the catalyst temperature of the low temperature shift reaction unit 13, and the catalyst temperature of the selective oxidation reaction unit 8 are all increased and the reference temperatures SL2, SL3, The temperature was higher than SL4 and SL5. In such a case, the temperature of each part of the hydrogen production apparatus 1 becomes too high, and the time during which the independent operation can be maintained is shortened. Therefore, it is understood that the self-sustaining operation state can be further increased for a long time by setting S / C to 6.0 or more. Furthermore, the raw fuel supply pump 110 was controlled so that the raw fuel supply amount became larger than ¼ of the maximum efficiency supply amount P1 by increasing the raw fuel supply amount from time t13 to t14. At this time, the flame temperature of the burner 10, the outlet temperature of the reforming unit 6, the catalyst temperature of the low temperature shift reaction unit 13, and the catalyst temperature of the selective oxidation reaction unit 8 are all increased and the reference temperatures SL2, SL3, The temperature was higher than SL4 and SL5. In such a case, the temperature of each part of the hydrogen production apparatus 1 becomes too high, and the time during which the independent operation can be maintained is shortened. Therefore, it is understood that the self-sustaining operation state can be further extended for a long time by setting the raw fuel supply amount to ¼ or less of the maximum efficiency supply amount P1.

  In the fuel cell system 100 according to the present embodiment, the control unit 200 can set the supply destination of the reformed gas to the cell stack 20 after the error detected at least in S10 is resolved. In this way, by supplying the reformed gas to the cell stack 20 after the detected error is eliminated, power generation can be performed promptly after the error is eliminated.

  In the fuel cell system 100 according to the present invention, the control unit 200 repeatedly detects the error detected in S10 after the reformed gas supply destination is set only to the burner 10, and the number of times of the error detection is determined. When it becomes more than a threshold value, the driving | operation of the hydrogen production apparatus 1 can be stopped. That is, when it takes a predetermined time or more to eliminate an error in the system, the operation of the hydrogen production apparatus 1 in the autonomous operation state can be stopped. As a result, for example, in a situation where the loss of energy is smaller when the hydrogen production apparatus 1 is stopped than when the independent operation is continued, the hydrogen production apparatus 1 can be stopped.

Further, according to the control method of the fuel cell system 100 according to the present embodiment, in step S30 (reformed gas supply destination setting step), only the burner 10 out of the burner 10 and the cell stack 20 is the supply destination of the reformed gas. Therefore, the hydrogen production apparatus 1 can be operated independently by returning all of the reformed gas generated in the hydrogen production apparatus 1 to the burner 10 using the bypass line L1. Here, in the case where an error other than an error relating to the hydrogen production apparatus 1 is detected in step S10 (error detection step), an error has occurred in a part other than the hydrogen production apparatus 1 in the system. 1 itself does not affect the processing for error elimination even if the autonomous operation is continued. Therefore, in the present embodiment, when an error other than an error related to the hydrogen production apparatus 1 is detected in S10, the supply destination of the reformed gas is set only to the burner 10 in Step S30, and Step S40 (Operation Control Step) ), At least the operation of the hydrogen production apparatus 1 is continued, whereby the hydrogen production apparatus 1 can be brought into a self-sustaining operation state. As a result, for the part where the error has occurred in the system, while performing the process for eliminating the error, the hydrogen production apparatus 1 that does not participate in the error is set in the self-sustaining operation state without stopping the operation. When the system is restarted, the reformed gas can be supplied to the cell stack 20 promptly without requiring energy or time for starting. As described above, even when an error occurs in the system, power generation can be restarted at an early stage, and an increase in CO ₂ emissions and a decrease in energy efficiency can be suppressed.

  The preferred embodiments of the present invention have been described above, but the fuel cell system and the control method according to the present invention are not limited to the fuel cell system and the control method according to each embodiment, and are described in each claim. It may be modified without changing the gist, or applied to other things.

  For example, the configuration of the hydrogen production apparatus shown in the above embodiment is an example, and the configuration of each component is not particularly limited, and the positional relationship and configuration of each flow path, pipe, or component may be changed as appropriate. Good. For example, the reforming unit 6 may be any unit that reforms raw fuel and water vapor, and may have a different structure. Moreover, the desulfurization part 2 does not need to be provided. Furthermore, although the said embodiment is provided with the high temperature shift reaction part 12 and the low temperature shift reaction part 13 as what carries out the shift reaction of the carbon monoxide in reformed gas, you may provide only the low temperature shift reaction part 13. FIG.

  The control process illustrated in FIG. 3 is also an example, and the part other than the process of setting the hydrogen production apparatus 1 in a self-sustaining operation state when an error other than an error related to the hydrogen production apparatus 1 is detected is changed as appropriate. It is possible. For example, the present embodiment is more effective in that the self-sustaining operation state of the hydrogen production apparatus 1 can be performed for a longer time by satisfying the optimum conditions in the processing of S60 and S70, but does not satisfy the optimum conditions. It is also possible to perform control under conditions (for example, by reducing the threshold value in S150 to shorten the self-sustaining operation state). When performing control that does not satisfy the optimum condition, the processing of S50, S60, S70, S100, and S110 shown in FIG. 3 may be omitted.

  DESCRIPTION OF SYMBOLS 1 ... Hydrogen production apparatus, 6 ... Reforming part, 10 ... Burner, 20 ... Cell stack (fuel cell stack), 100 ... Fuel cell system, 110 ... Raw fuel supply pump (raw fuel supply amount control means, S / C control) Means), 120 ... Water supply pump (S / C control means), 170 ... Bypass valve (reformed gas supply destination setting means), 180 ... Stack side valve (reformed gas supply destination setting means), 200 ... Control unit ( Error detection means, operation control means, reformed gas supply destination setting means, raw fuel supply amount control means, S / C control means).

Claims (5)

A hydrogen production apparatus comprising a reforming unit that generates a reformed gas containing hydrogen by reforming raw fuel and steam, and a burner that heats the reforming unit;
A fuel cell stack that generates electricity using the reformed gas generated by the hydrogen production apparatus,
Operation control means for controlling the operation of equipment in the fuel cell system;
Error detection means for detecting an error in the fuel cell system;
A reformed gas supply destination setting means for setting the supply destination of the reformed gas in the burner or the fuel cell stack,
When an error other than an error relating to the hydrogen production apparatus is detected by the error detection means,
The reformed gas supply destination setting means sets the reformed gas supply destination only to the burner,
The fuel cell system, wherein the operation control means continues the operation of at least the hydrogen production apparatus. Raw fuel supply amount control means for controlling the supply amount of the raw fuel supplied to the reforming unit;
S / C control means for controlling S / C determined by the molar ratio of the amount of water vapor supplied to the reforming unit with respect to the amount of carbon of the raw fuel supplied to the reforming unit. ,
When the reformed gas supply destination setting means sets the reformed gas supply destination only to the burner,
The raw fuel supply amount control means controls the supply amount of the raw fuel to be ¼ or less of a supply amount that maximizes hydrogen production efficiency,
2. The fuel cell system according to claim 1, wherein the S / C control means performs control so that the S / C is 6.0 or more.   2. The reformed gas supply destination setting means sets the supply destination of the reformed gas to the fuel cell stack after at least the error detected by the error detection means is resolved. Or the fuel cell system according to 2; The error detection means repeatedly detects errors other than errors related to the hydrogen production apparatus after the reformed gas supply destination setting means sets the reformed gas supply destination only to the burner,
4. The fuel according to claim 1, wherein the operation control unit stops the operation of the hydrogen production apparatus when the number of times of error detection by the error detection unit exceeds a threshold value. 5. Battery system. A hydrogen production apparatus comprising a reforming unit that generates a reformed gas containing hydrogen by reforming raw fuel and steam, and a burner that heats the reforming unit;
A fuel cell system comprising: a fuel cell stack that generates power using the reformed gas generated by the hydrogen production device,
An error detection step of detecting an error in the fuel cell system;
Reform gas supply destination setting for setting the reform gas supply destination to only the burner of the burner and the fuel cell stack when an error other than an error relating to the hydrogen production apparatus is detected by the error detection step Steps,
An operation control step for continuing operation of the hydrogen production apparatus.

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