JP2002184441A - Fuel cell device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow the power consumed by a load connected to a fuel cell to match the amount of reforming fuel supplied to a fuel cell device. SOLUTION: The fuel cell device having a fuel cell 40 reforms town gas supplied thereto, and hydrogen generated through a reforming reaction is supplied to the fuel cell 40. The fuel cell 40 supplies the generated power to a household electric load 80. The electric load 80 shows a prescribed periodicity when the power consumed thereby fluctuates, with one year or one weak as one period. The amount of the town gas subjected to the reforming reaction is determined based on the periodicity shown by the fluctuation when the power for the electric load 80 is consumed, whereby the power actually consumed by the electric load 80 is matched with the amount of the power generated by the fuel cell 40.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell device, and more particularly, to a stationary fuel cell device which receives a commercial gas and reforms it.

[0002]

2. Description of the Related Art A fuel cell device is an energy generating device having high energy efficiency, and various uses thereof have been conventionally studied. As one example, it is known to be used as a power source for small-scale cogeneration used in facilities such as homes, apartment houses, and office buildings. That is, when a stationary (on-site) fuel cell device is used as, for example, a household power supply, heat generated in each part of the fuel cell device can be used for heating, hot water supply, and the like. It is expected that the entire facility including the fuel cell device can be further improved in energy efficiency.

[0003]

Here, when a fuel cell device is used as a power source for small-scale cogeneration as described above, usually, commercial gas such as city gas is purchased as reforming fuel, and Power is generated by supplying hydrogen generated by reforming the fuel cell device to the fuel cell device.However, power consumption in facilities such as homes and apartment houses receiving the power supply and the amount of reformed fuel supplied for reforming are: If the balance is not sufficient, there is a possibility that the power generation efficiency may decrease and the power generation cost may increase.

[0004] That is, when the fuel cell generates power in an amount corresponding to the power consumption in the facility, when the reformed fuel in an amount exceeding the reformed fuel amount corresponding to the generated power is used for reforming. In addition, a part of the reformed fuel and hydrogen generated from the reformed fuel may be wasted, which may cause a decrease in energy efficiency. Alternatively, when the fuel cell generates an amount of power corresponding to the amount of hydrogen generated from the excessively supplied reformed fuel, a separate power storage means for storing the surplus power is provided, or the surplus power is externally supplied. Needs to be sold to a power company. Providing large storage means
It is hard to say that it is desirable in view of the use as the power source for the small-scale cogeneration, and it is not desirable to increase the size of the device. When selling surplus electricity, there is a possibility that the cost may increase due to the relationship between the purchase price of the reformed fuel and the sale price of the electricity. Further, when an excessive amount of electric power is generated, there is a possibility that the life of the fuel cell device is undesirably shortened.

[0005] In addition, if the reformed fuel is supplied in an insufficient amount compared with the amount of reformed fuel corresponding to the power consumption in the facility, a desired amount of power cannot be generated. The shortfall will need to be purchased from an external power company to make up for it. In such a case, the effect of realizing high energy efficiency in the entire facility may not be sufficiently obtained by the cogeneration. As described above, it is desirable that the power consumption in the facility and the amount of reformed fuel supplied for reforming in the fuel cell device be sufficiently balanced. An effective method for achieving the above has not been known in the past.

The fuel cell device of the present invention solves such a problem, and in a fuel cell device used as a cogeneration power supply, balances the power consumption of a predetermined load with the amount of reformed fuel supplied to the fuel cell device. The following configuration is adopted for the purpose of planning.

[0007]

The first fuel cell device of the present invention is a stationary fuel cell device having a fuel cell for supplying electric power to a specific load, and is a commercial fuel cell device. A reformer that receives the supply of gas to advance the reforming reaction, generates hydrogen, a reformed fuel supply unit that supplies the commercial gas to the reformer, and converts the hydrogen generated by the reformer into hydrogen. A hydrogen supply means for supplying to the fuel cell, and a reformed fuel for determining an amount of the commercial gas to be supplied to the reformer based on periodicity shown when power consumption of the specific load fluctuates. An amount determining means, wherein the reformed fuel supply means supplies the commercial gas to the reformer in accordance with the amount of the commercial gas determined by the reformed fuel amount determining means. .

The first fuel cell device of the present invention having the above-described structure is a stationary fuel cell device, in which a reformer receives a supply of a commercial gas to cause a reforming reaction to proceed so that hydrogen is produced. When generating the gas, the amount of the commercial gas to be supplied to the reformer is determined based on the periodicity when the power consumption of the specific load fluctuates. The hydrogen generated by the reformer is supplied to the fuel cell, and the generated power is supplied to a specific load.

The first method of operating a fuel cell device according to the present invention is a method of operating a stationary fuel cell device having a fuel cell for supplying electric power to a specific load,
(A) determining an amount of a commercial gas to be subjected to a reforming reaction for generating hydrogen to be supplied to the fuel cell, based on periodicity when the power consumption of the specific load fluctuates; (B) subjecting the commercial gas to the reforming reaction in accordance with the determination in the step (a) to generate hydrogen from the commercial gas; and (c) converting the hydrogen generated in the reforming reaction into a fuel. Supplying the gas to the fuel cell as a gas;
The gist is to provide.

[0010] Such a first fuel cell device of the present invention,
According to the first method of operating the fuel cell device of the present invention, the amount of commercial gas to be supplied to the reformer is determined based on the periodicity when the power consumption of the specific load fluctuates. Therefore, the electric power generated by the fuel cell can be accurately approximated to the power consumption of the specific load. Therefore, when power is supplied to the specific load using the fuel cell device, the power generated by the fuel cell is insufficient and it is necessary to supplement the power externally, or an excessive amount of commercial gas is supplied to the fuel cell. Can be suppressed. When the first fuel cell device of the present invention is used as a cogeneration power supply installed in a specific facility having the specific load, a cogeneration power supply that realizes higher energy efficiency at lower cost is provided. The effect can be sufficiently realized.

In the first fuel cell device of the present invention, the reforming fuel amount determining means may include a periodicity of one year as one cycle when the power consumption of the specific load varies. The amount of the commercial gas may be determined based on at least one of periodicity of one week as one cycle and periodicity of one day as one cycle.

Further, in the first method of operating a fuel cell device according to the present invention, in the step (a), one year is defined as one cycle when the power consumption of the specific load varies. The amount of the commercial gas may be determined based on at least one of periodicity, one cycle of one week, and one cycle of one day. .

With such a configuration, the predetermined effect of making the power generated by the fuel cell close to the power consumption of the specific load according to the type of periodicity used in determining the amount of the commercial gas. Can be obtained.

[0014] In the first fuel cell device of the present invention, the fuel cell system further comprises power consumption detecting means for detecting the magnitude of the actual power consumption at the specific load, and the reforming fuel amount determining means is adapted to detect the periodicity. In addition, the amount of the commercial gas to be supplied to the reformer may be determined on the basis of the magnitude of the power consumption at the specific load detected by the power consumption detection unit during the past fixed time. good.

Further, in the first operating method of the fuel cell device according to the present invention, the method further comprises a step (d) of detecting an amount of actual power consumption at the specific load, and the step (a) comprises: Determining the amount of the commercial gas to be subjected to the reforming reaction further based on the magnitude of power consumption at the specific load detected in the step (d) during the past fixed time in addition to the periodicity It is good.

With such a configuration, even when a temporary fluctuation not reflected in the periodicity occurs in the power consumption of the specific load, the power generation amount of the fuel cell follows the fluctuation. It becomes possible to bring the power generated by the fuel cell closer to the power consumption of the specific load,
More sufficiently can be secured.

[0017] In the first fuel cell device of the present invention, the fuel cell device further comprises power consumption detecting means for detecting the magnitude of the actual power consumption at the specific load, and the reforming fuel amount determining means relates to the periodicity. A storage unit that stores information, and a period information correction unit that corrects the information about the periodicity stored by the storage unit based on the magnitude of the actual power consumption detected by the power consumption detection unit,
The commercial gas amount may be determined with reference to the information on the periodicity stored in the storage unit and corrected by the periodic information correction unit.

Further, in the first method for operating a fuel cell device according to the present invention, (d) a step of detecting the magnitude of the actual power consumption at the specific load, and (e) storing information on the periodicity. Correcting the information on the periodicity stored in the storage means based on the magnitude of the actual power consumption detected in the step (d). The amount of the commercial gas may be determined with reference to the storage unit that stores the information on the periodicity corrected in the step (e).

With this configuration, the power generated by the fuel cell can be adjusted to the specific load by correcting the information on the periodicity stored in the storage means based on the actual power consumption. It is possible to further improve the accuracy of approaching the power consumption.

The second fuel cell device according to the present invention is a stationary fuel cell device provided with a fuel cell for supplying electric power to a specific load. A reformer that generates hydrogen, a reformed fuel supply unit that supplies the commercial gas to the reformer, and a hydrogen supply unit that supplies the hydrogen generated by the reformer to the fuel cell. The power consumption of the specific load is predicted based on the history of the actual power consumption of the specific load in the past, and the revised power consumption is estimated so that the fuel cell can generate the predicted power consumption. Reformed fuel amount determining means for determining the amount of the commercial gas to be supplied to the reformer, the reformed fuel supply means according to the amount of the commercial gas determined by the reformed fuel amount determining means, Supply the commercial gas to the reformer The gist of the Rukoto.

The second fuel cell device of the present invention having the above-described structure is a stationary fuel cell device, in which a reformer receives a supply of commercial gas to cause a reforming reaction to proceed, and the hydrogen is reacted. When generating the gas, the amount of the commercial gas to be supplied to the reformer is determined based on the history of the actual power consumption of the specific load in the past. The hydrogen generated by the reformer is supplied to the fuel cell, and the generated power is supplied to a specific load.

The second method of operating a fuel cell device according to the present invention is a method of operating a stationary fuel cell device having a fuel cell for supplying electric power to a specific load,
(A) predicting the power consumption of the specific load based on the history of actual power consumption of the specific load in the past, and allowing the fuel cell to generate the predicted power consumption. Determining the amount of a commercial gas to be subjected to a reforming reaction for producing hydrogen to be supplied to the fuel cell; and (b) subjecting the commercial gas to the reforming reaction according to the determination in the step (a). And generating hydrogen from the commercial gas; and (c) supplying the hydrogen generated by the reforming reaction to the fuel cell as a fuel gas.

[0023] Such a second fuel cell device of the present invention,
According to the operation method of the second fuel cell device, the amount of commercial gas to be supplied to the reformer is determined based on the history of the actual power consumption of the specific load in the past. Can be accurately brought close to the power consumption of the specific load. Therefore, when power is supplied to the specific load using the fuel cell device, the power generated by the fuel cell is insufficient and it is necessary to supplement the power externally, or an excessive amount of commercial gas is supplied to the fuel cell. Can be suppressed. When the second fuel cell device of the present invention is used as a cogeneration power supply installed in a specific facility having the specific load, a cogeneration power supply that realizes higher energy efficiency at lower cost is provided. The effect can be sufficiently realized.

In the first and second fuel cell devices of the present invention, the reformed fuel amount determining means performs a phase lead correction when determining the amount of the commercial gas to be supplied to the reformer. A first correction unit may be provided.

[0025] In the first and second operating methods of the fuel cell device according to the present invention, the step (a) includes correcting the phase advance when determining the amount of the commercial gas to be subjected to the reforming reaction. May be performed.

With this configuration, a predetermined delay may occur between the supply of the determined amount of commercial gas to the fuel cell device and the supply of the desired amount of hydrogen to the fuel cell. In this case, it is possible to prevent inconvenience caused by such a delay.

In the first and second fuel cell devices of the present invention, the reformed fuel supply means further includes a supply gas amount detection means for detecting an amount of the commercial gas actually supplied to the reformer, The reformed fuel supply unit, when supplying the commercial gas according to the amount of the commercial gas determined by the reformed fuel amount determination unit, the amount of the commercial gas determined in the past by the reformed fuel amount determination unit And, based on the difference between the amount of the commercial gas actually supplied by the reformed fuel supply unit and the amount of the commercial gas detected by the supplied gas amount detection unit, the commercial gas actually supplied to the reformer is Second to correct the amount
May be provided.

Further, in the first and second operating methods of the fuel cell device according to the present invention, the method further comprises (f) a step of detecting an amount of the commercial gas actually supplied to the reforming reaction, The step (b) comprises, when subjecting the commercial gas to the reforming reaction in accordance with the determination in the step (a), the amount of the commercial gas determined in the past when the step (a) was executed; And the amount of the commercial gas actually supplied to the reforming reaction is corrected based on the difference from the amount of the commercial gas detected in the (b) step and the amount of the commercial gas detected in the (f) step. Is also good.

With this configuration, it is possible to prevent an error from occurring between the amount determined as the amount of commercial gas supplied to the reformer and the amount of small gas actually supplied to the reformer. ,
The effect of bringing the power generated by the fuel cell closer to the power consumption of a specific load can be further enhanced.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to further clarify the structure and operation of the present invention described above, embodiments of the present invention will be described below in the following order based on examples. (1) Configuration of fuel cell device 10 (2) Control of supplied city gas amount (2-1) Periodicity when electric load fluctuates (2-2) Correction based on power consumption (2-3) Example of actual operation

(1) Structure of fuel cell device 10: FIG.
FIG. 1 is a block diagram schematically illustrating a configuration of a fuel cell device 10 according to a preferred embodiment of the present invention. This fuel cell device 1
Numeral 0 is provided as a cogeneration power supply for home use, and the power generated by the fuel cell 40 included in the fuel cell device 10 is supplied to various home electrical loads. FIG. 2 is an explanatory diagram showing a state of connection between the fuel cell 40 and the above-mentioned domestic electric load.
The fuel cell device 10 of this embodiment generates hydrogen using city gas as a reforming fuel, generates electric power by using the generated hydrogen, and supplies electric power to the above-mentioned domestic electric load. . Further, the fuel cell device 10 of the present embodiment is characterized in that the amount of city gas used as the reforming fuel is determined based on the periodicity shown when the household electric load fluctuates. Fuel cell device 1 based on FIG.
0 will be described.

The fuel cell device 10 receives a supply of city gas and water vapor and mixes and raises the temperature of the supply.
0, a combustion unit 22 that generates heat required by the temperature raising unit 20, a reforming unit 24 that generates a hydrogen-rich gas by a reforming reaction, and a carbon monoxide (CO) concentration in the hydrogen-rich gas discharged from the reforming unit 24. CO oxidation part 2 reduced by oxidation reaction
6. The main components are a fuel cell 40 that obtains an electromotive force by an electrochemical reaction, a blower 28 that compresses air and supplies the compressed air to the fuel cell 40, and a control unit 50 that is configured by a computer. Hereinafter, each component will be described in order.

A gas passage 60 and a steam passage 62 are connected to the temperature raising section 20. The gas flow path 60 is a flow path connected to a pipe of city gas which is a commercial gas. Also,
The steam passage 62 is a passage to which steam is supplied from an external preheater. In the gas flow path 60, the flow control valve 32
And the flow rate sensor 36 are provided.
Is provided with a flow control valve 34 and a flow sensor 38. The flow control valve 32 and the flow control valve 34 are valves that can adjust the amount of city gas and the amount of water vapor supplied to the heating unit 20, respectively. The flow sensor 36 and the flow sensor 38 are respectively controlled by the heating unit 20. Is a sensor for detecting the amount of city gas and the amount of water vapor actually supplied.
The flow control valve and the flow sensor are connected to the control unit 50. When the city gas supplied via the gas flow channel 60 contains a sulfur compound, a desulfurizer is provided in the gas flow channel 60 to desulfurize the city gas, and
0 may be supplied.

The heating section 20 is a device for superheating steam supplied through the steam passage 62 and mixing with city gas supplied through the gas passage 60 to heat both. Then, a raw fuel gas composed of city gas and water vapor is generated, which is heated to a predetermined temperature and discharged. The raw fuel gas discharged from the temperature raising section 20 is supplied to the reforming section 24 via the gas flow channel 63. Heating unit 20
Is provided with a combustion unit 22 as a heat source for raising the temperature of city gas and water vapor. The combustion unit 22 includes a combustion catalyst therein, and is supplied with city gas as a fuel for combustion via a gas flow channel 61, and is supplied with air by a blower 23 attached thereto. Gas flow path 61
Is a flow path connected to the pipe of city gas, which is a commercial gas, similarly to the gas flow path 60, and is a flow control valve that is driven by the control unit 50 and adjusts the amount of city gas supplied to the combustion unit 22. 30. When fuel for combustion is supplied to the combustion section 22, a combustion reaction proceeds on the catalyst using the fuel and air, and desired heat is generated. Combustion unit 22
A heat exchanging unit 21 is provided between the heating unit 20 and the heating unit 20, and heat generated in the combustion unit 22 is transmitted to the heating unit 20 by the heat exchanging unit 21. In the present embodiment, as the fuel for the combustion supplied to the combustion unit 22, in addition to the city gas supplied through the gas flow path 61, an anode exhaust gas discharged from a fuel cell 40 described later is also used. Available (not shown).

The reforming section 24 includes a reforming catalyst therein, and reforms the raw fuel gas comprising the supplied city gas and water vapor to generate a hydrogen-rich gas. The main component of the city gas is methane, and as the reforming catalyst, a nickel catalyst was used in this embodiment. In the present embodiment, as described above, steam is supplied to the reforming unit 24, and a hydrogen-rich gas is generated by the steam reforming reaction. Air may be further supplied into the section 24. With such a configuration, hydrogen can be generated by a partial oxidation reaction of city gas (methane). In such a case,
The heat required in the steam reforming reaction can be covered by the heat generated in the partial oxidation reaction. Of course, the reforming unit 24
A heating device such as a heater is provided in addition to the heat amount generated by the partial oxidation reaction, or the heat amount required for the steam reforming reaction when the partial oxidation reaction is not performed by providing the blower 25. It is good also as a structure generated using a heating device.

The reaction proceeding on the reforming catalyst is as follows:
By maintaining the catalyst temperature within a predetermined temperature range, it is possible to obtain a sufficiently high activity. The above-mentioned reforming catalyst has a temperature of 600 ° C. showing sufficient activity to promote the above-mentioned reactions (steam reforming reaction and partial oxidation reaction of methane).
That is all. Therefore, when the raw gas is generated by mixing and raising the temperature of the city gas and the steam in the temperature raising section 20 described above, the reaction temperature of the reforming section 24 is 600.
The temperature of the raw fuel gas is sufficiently raised so as to correspond to a predetermined temperature of not less than ° C. and discharged to the reforming section 24 side. In the reforming unit 24, the amount of air supplied to the reforming unit 24 to advance the partial oxidation reaction is controlled, or the amount of heat generated by the heating device described above is controlled. The internal temperature is controlled so as to be maintained in a temperature range of 600 ° C to 800 ° C. The hydrogen-rich gas generated in the reforming unit 24 is supplied to the CO oxidizing unit 26 via the gas passage 64.

The CO oxidizing unit 26 is a device for reducing the concentration of carbon monoxide in the hydrogen-rich gas generated in the reforming unit 24. The hydrogen-rich gas generated by the reforming reaction in the reforming unit 24 contains a predetermined amount of carbon monoxide, and the fuel cell 40 that receives the supply of the hydrogen-rich gas as the fuel gas includes When carbon monoxide is contained, the catalyst has the property of poisoning the catalyst and inhibiting the electrochemical reaction. Therefore, in the fuel cell device 10 of the present embodiment, the CO oxidizing unit 2
6 is provided to supply a hydrogen-rich gas to the fuel cell 40 after reducing the concentration of carbon monoxide. The reaction that proceeds in the CO oxidation unit 26 is a carbon monoxide selective oxidation reaction that oxidizes carbon monoxide in preference to hydrogen abundantly contained in the hydrogen-rich gas. The CO oxidizing section 26 is filled with a carrier carrying a platinum catalyst, a ruthenium catalyst, a palladium catalyst, a gold catalyst, or an alloy catalyst using these as the first element, which are selective oxidation catalysts for carbon monoxide. Under such a carbon monoxide selective oxidation catalyst, the reaction temperature is set to 100 ° C. to 20 ° C.
By maintaining the temperature at about 0 ° C., the selective oxidation reaction of carbon monoxide proceeds favorably.

The CO oxidizing unit 26 is provided with a blower 27 in order to supply oxygen required for the selective oxidation reaction of carbon monoxide which proceeds in the CO oxidizing unit 26. Blower 2
7 takes in air from the outside, compresses it, and supplies it to the CO oxidizing unit 26. The drive amount of the blower 27, that is,
By adjusting the amount of air (oxygen) supplied to the CO oxidizing unit 26, the state of the carbon monoxide selective oxidation reaction progressing in the CO oxidizing unit 26 can be controlled.

The carbon monoxide selective oxidation reaction that proceeds in the CO oxidation section 26 is an exothermic reaction. Therefore, CO
It is also preferable that the oxidizing unit 26 includes a predetermined cooling means inside in order to keep the internal temperature (catalyst temperature) at the above-mentioned desired reaction temperature.

The hydrogen-rich gas whose carbon monoxide concentration has been reduced in the CO oxidizing section 26 as described above is supplied to the fuel gas passage 65.
The fuel gas is led to the fuel cell 40 and is supplied to the cell reaction on the anode side as a fuel gas. Although not all of the hydrogen in the fuel gas is consumed in the electrochemical reaction, the anode exhaust gas discharged after being subjected to the cell reaction in the fuel cell 40 is supplied to the combustion unit 22 as described above. By using it as fuel for the combustion reaction, the energy efficiency of the entire fuel cell device 10 can be improved.
On the other hand, the oxidizing gas related to the cell reaction on the cathode side of the fuel cell 40 is supplied as compressed air through the oxidizing gas passage 66 by the blower 28 which outputs a drive signal from the control unit 50. The remaining cathode exhaust gas used for the battery reaction is discharged outside.

The fuel cell 40 is a solid polymer electrolyte type fuel cell, and is configured by stacking a plurality of unit cells each having an electrolyte membrane, an anode, a cathode, and a separator. The electrolyte membrane is, for example, a proton-conductive ion exchange membrane formed of a solid polymer material such as a fluorine-based resin. The anode and the cathode are both formed of carbon cloth woven from carbon fibers. Further, a catalyst layer provided with a catalyst for promoting an electrochemical reaction is provided between the electrolyte membrane and the anode or the cathode.
As such a catalyst, platinum or an alloy composed of platinum and another metal is used. The separator is formed of a gas-impermeable conductive member such as dense carbon which is made gas-impermeable by compressing carbon, or a metal having excellent corrosion resistance. The separator forms a flow path for the fuel gas and the oxidizing gas between the anode and the cathode. The fuel cell 40 is supplied with the hydrogen-rich gas as the fuel gas and the compressed air as the oxidizing gas into the above-mentioned flow path, and generates an electromotive force by advancing an electrochemical reaction. The electric power generated in the fuel cell 40 is supplied to a predetermined load connected to the fuel cell 40. Hereinafter, an electrochemical reaction that proceeds in the fuel cell 40 will be described. Equation (1) shows the reaction on the anode side, and equation (2) shows the reaction on the cathode side, and the reaction shown in equation (3) proceeds in the whole battery.

H ₂ → 2H ⁺ + 2e ⁻ (1) (1/2) O ₂ + 2H ⁺ + 2e ⁻ → H ₂ O (2) H ₂ + (1/2) O ₂ → H ₂ O (3) )

The control unit 50 is configured as a logic circuit centered on a microcomputer. More specifically, the control unit 50 executes a predetermined operation or the like according to a preset control program. A ROM 56 in which necessary control programs, control data, and the like are stored in advance, and an R for temporarily reading and writing various data necessary for performing various arithmetic processing by the CPU 54.
AM58 and the flow sensor 3 provided in the fuel cell device 10
While inputting detection signals from various sensors such as 6, 38 and information related to the load connected to the fuel cell,
An input / output port 52 for outputting a drive signal to each of the blowers, flow control valves, and the like described above in accordance with the calculation results of the CPU 54 is provided. The control unit 50 controls the operating state of the entire fuel cell device 10 by inputting and outputting various signals as described above.

In the above embodiment, as the carbon monoxide concentration reducing unit for reducing the carbon monoxide concentration in the hydrogen-rich gas generated by the reforming reaction, the CO oxidizing unit 26 for performing the carbon monoxide selective oxidation reaction is provided. However, in addition to or instead of the CO oxidizing unit 26, a shift unit for performing a shift reaction for generating carbon dioxide and hydrogen from carbon monoxide and water vapor is provided, and a hydrogen-rich gas is provided. The concentration of carbon monoxide therein may be reduced. In addition, since the reaction temperature of the reforming reaction is generally higher than the reaction temperature of the above-described reaction for reducing the concentration of carbon monoxide, it is necessary to supply the hydrogen-rich gas generated by the reforming reaction to the carbon monoxide reduction reaction. Prior to this, a heat exchange unit may be provided downstream of the reforming unit 24 in order to lower the temperature of the hydrogen-rich gas.

The fuel cell 4 included in the fuel cell device 10
The electric power generated at 0 is supplied to a load in a facility where the fuel cell device 10 is provided, here, a domestic electric load. As shown in FIG. 2, various types of home electrical loads can be given. Although an AC current is used in these domestic electric loads, the fuel cell 4
0 is a DC-AC inverter for generating a DC current, and for connecting the fuel cell 40 to a domestic electric load.
Is provided. The DC current generated by the fuel cell 40 is converted into an AC current by the DC-AC inverter 70 and supplied to the domestic electric load.

A power meter 72 is provided at the connection between the DC-AC inverter 70 and the home electric load.
The total amount of household electrical load can be detected. The wattmeter 72 is connected to the control unit 50 described above, and information regarding the total amount of domestic electric load is input to the control unit 50.
In addition, an external line 74 is provided between the DC-AC inverter 70 and the home electric load, which enables the purchase and sale of electric power with an external electric power company. After converting power supplied to an electric load or generated by the fuel cell device 10 into an alternating current,
It is possible to sell to a power company.

(2) Control of supply city gas amount: As described above, in the fuel cell device 10 of the present embodiment, the reforming reaction is performed based on the periodicity when the electric load in the home fluctuates. The amount of city gas to be provided is determined. Hereinafter, the periodicity shown when the home electric load fluctuates will be described.

(2-1) Periodicity when Electric Load Fluctuates: In the fuel cell device 10 of the present embodiment, one year is used as the periodicity when the size of the domestic electric load 80 fluctuates. Using a periodicity of one cycle, a periodicity of one week as one cycle, and a periodicity of one day as one cycle,
The amount of city gas to be used for the reforming reaction is determined. FIG.
FIG. 4 shows an example in which the fluctuation of the domestic electric load has a periodicity with one cycle as one year, and FIG. 4 shows an example in which the fluctuation of the electric load in the home has a periodicity with one cycle as one week. FIG. 5 shows that the fluctuation of the domestic load is one day (24 hours).
Examples showing that they have a periodicity, which is a period, will be described below.

In FIG. 3, the horizontal axis represents each month constituting one year, and the vertical axis represents power consumption. FIG. 3 shows a curve connecting the points where the magnitudes of the power consumption in each month are plotted. In the example shown in FIG. 3, the power consumption (the magnitude of the household electrical load) is calculated in summer and winter. It is getting bigger at the time corresponding to. Such a tendency occurs, for example, when the amount of use of a cooling / heating device such as an air conditioner or a fan heater in the domestic electric load increases in summer or winter. As described above, when the power consumption of each household fluctuates, it is possible to recognize a predetermined periodicity with one year as one cycle. As shown in FIG. 3, the control unit 50 included in the fuel cell device 10 according to the present embodiment controls the power consumption corresponding to each month (Xff1) constituting one year (periodicity with one year as one cycle). (MAP1) for storing the power consumption Uff1).

That is, each month constituting one year (Xff1)
And the power consumption (Uff1) for the month, the function Uff1 [kW] = MAP1 (Xff1) (4) is treated as being satisfied.

In the fuel cell device 10 of this embodiment, the magnitude of the domestic electric load 80 is predicted by referring to this map. The MAP1 for obtaining the power consumption Uff1 indicating the periodicity with one cycle as one year may be prepared in advance and stored in the control unit 50, and may be used. The learning operation of correcting the MAP1 data as needed based on the value of the home electric load 80 actually measured by 72 is performed.
The learning of this map will be described later. In addition, the power consumption of the household electric load 80 fluctuates during one month constituting each month, but a method of setting a value stored in the MAP 1 as the power consumption of each month will be described later.

In FIG. 4, the horizontal axis represents each day of the week which constitutes one week (for example, in FIG. 4, 1 represents a Monday and 2 represents a Tuesday), and the vertical axis represents power consumption. . FIG. 4 shows a curve connecting the points where the magnitude of the power consumption for each day of the week is plotted. In the example shown in FIG. 4, the power consumption (the magnitude of the household electrical load) is the weekend holiday. It is getting bigger at the time corresponding to. Such a tendency may occur, for example, in a home where a part of cleaning, washing, or cooking is performed on a weekend. Conversely, in a home where a lot of people go out on weekends, the tendency shown in FIG. 4 does not occur, and the power consumption tends to decrease on the weekend. As described above, when the power consumption of each home fluctuates, it is possible to recognize a predetermined periodicity with one week as one cycle. As shown in FIG. 4, the control unit 50 included in the fuel cell device 10 according to the present embodiment performs power consumption corresponding to each day of the week (Xff2) constituting one week (periodicity with one week as one cycle). And a map (MAP2) for storing power consumption Uff2).

That is, each day of the week (Xff
2) and the power consumption (Uff2) of the day of the week are treated as if the function of Uff2 [kW] = MAP2 (Xff2) (5) holds.

In the fuel cell device 10 of the present embodiment, the M
By referring to the MAP2 in addition to the AP1, the size of the home electric load 80 is predicted.
Similarly to MAP1, MAP2 performs a learning operation of correcting map data as needed based on the value of the home electric load 80 actually measured by the wattmeter 72.

In FIG. 5, the abscissa axis represents each time (0:00 to 24:00) constituting one day, and the ordinate axis represents power consumption. FIG. 5 shows a curve connecting the points where the magnitude of the power consumption at each time in a day is plotted. In the example shown in FIG. 5, the power consumption (the magnitude of the household electrical load) is shown.
Is increased from the time of getting up to bedtime. As described above, when the power consumption of each home fluctuates, it is possible to recognize a predetermined periodicity with one cycle as one day. The control unit 50 included in the fuel cell device 10 of the present embodiment
Is a map (MAP) for storing power consumption (power consumption Uff3 indicating periodicity with one cycle per day) corresponding to each time (Xff3) constituting one day, as shown in FIG.
3) is provided.

That is, each time (Xff3
) And the power consumption at that time (Uff3), it is assumed that the function of Uff3 [kW] = MAP3 (Xff3) (6) holds.

In the fuel cell device 10 of the present embodiment, the above M
By referring to MAP3 in addition to AP1 and MAP2, the size of the home electric load 80 is predicted. Also in MAP3, MAP1 and MAP
Similar to 2, the learning operation of correcting the map data as needed based on the value of the home electric load 80 actually measured by the wattmeter 72 is performed.

(2-2) Correction based on power consumption: In the following, each of the above-described maps for storing data relating to fluctuating power consumption while showing periodicity is calculated based on the actually measured size of the household electric load 80. The operation of performing the correction will be described. First, an operation for correcting data stored in the MAP 1 will be described. Equation (7) is an equation representing the operation of correcting the data of month j (Ymap1j) in MAP1 when the power consumption (L1j (i)) in month j of the i-th year is detected using the wattmeter 72. is there.

Ymap1j (i) = (Ymap1j (i-1) + Ymap1j (i-2) + L1j (i)) / 3 (7) Here, MAP1 = table (X: 1, 2,..., 12) , Y: Ymap101, Ymap102, ..., Ymap112) (8)

That is, when the power consumption (L1j (i)) in the j-th month of the i-th year is detected, the detected value and MAP
1 (i-1) data for the jth year (Ymap1j (i-
1)) and the average value of the “i-2” th j-month data (Ymap1j (i-2)) in MAP1 are obtained to obtain the jth-month ith data (Ymap1j (i)). MAP1 is newly stored as j-month data (Ymap1j) to be used when MAP1 is referred to when performing an operation to be described later for determining the reformed fuel amount.

Here, the power consumption (L1j (i)) in the j-month of the i-th year is a value detected by the wattmeter 72 as described above, but in the fuel cell device 10 of this embodiment, The value is obtained as an integrated average value of the power consumption detected continuously during the j-month of the i-th year. The formula for calculating the power consumption (L1j (i)) in the j-th month of the i-th year is shown below.

L1j (i) = (Σ (W1j × ΔH1)) / H1 (9) where, W1j: power value [kW] for each sample time ΔH1: sample time, for example, 1 [H] H1: month It represents the total time, for example, 30 × 24 [H].

As described above, as the power consumption in each month, the power consumption value detected by the wattmeter 70 is read for each sample time (1 hour), and is multiplied by the sample time to accumulate the value for one month. Then, after integrating for one month, this integrated value is divided by the total time of the month corresponding to the sample time (the length of one month in hours since the sample time is one hour). (J month) power consumption (L1j). In the above equation (9), the sample time is set to one hour, but a different sample time such as one minute or one second can be selected. The length of the sample time may be a period sufficiently shorter than the period of integration (one month in this case), and may be appropriately set in consideration of the load on the memory, required accuracy, and the like.

Next, the operation of correcting the data stored in the MAP 2 will be described. The following equation (10) corrects the data (Ymap2j) of the MAP2 on the jth day when the power consumption (L2j (i)) on the jth day (day of the week) of the ith week is detected using the wattmeter 72. This is an expression representing an operation.

Ymap2j (i) = (Ymap2j (i-1) + Ymap2j (i-2) + L2j (i)) / 3 (10) where MAP2 = table (X: 1, 2,..., 7 , Y: Ymap201, Ymap202,..., Ymap207) (11).

That is, when the power consumption (L2j (i)) on the j-th day of the i-th week is detected, the detected value is compared with the data (Ymap2j (i-1)) of the MAP2 on the j-th day of the "i-1" th week.
And the data of “i−2” week j day in MAP2 (Y
map2j (i-2)) to obtain data (Ymap2j (i)) on the j-th day of the i-th week and refer to MAP2 when performing an operation to be described later for determining the amount of reformed fuel. J used for
It is newly stored in MAP2 as date data (Ymap2j).

Here, the power consumption (L2j (i)) on the jth day of the i-th week is a value detected by the wattmeter 72 as described above, but in the fuel cell device 10 of this embodiment, The value is obtained as an integrated average value of the power consumption detected continuously during the i-th week and the j-th day. The formula for calculating the power consumption (L2j (i)) on the jth day of the i-th week is shown below.

L2j (i) = (Σ (W2j × ΔH2)) / H2 (12) Here, W2j: power value [kW] for each sample time ΔH2: sample time, for example, 1 [min] H2: one day Total time, for example, 24 × 60 [mi
n].

As described above, the power consumption on each day (day of the week) is calculated by the power meter 70 for each sample time (one minute).
, Reads the detected power consumption value, multiplies the detected power consumption value by the sample time, and continues the integration for one day. When the integration is performed for one day and one month, the integrated value is used as the total time of the day according to the sample time ( Since the sample time is one minute, the power consumption (L2j) on that day (day j) is determined by dividing one day by the length expressed in minutes. In addition,
In the above equation (12), the sampling time is one minute, but a different value may be selected as described above.

Next, the operation of correcting the data stored in the MAP 3 will be described. The following equation (13) represents an operation of correcting the data (Ymap3j) of the MAP3 at the time j when the power consumption (L3j (i)) at the time j of the ith day is detected using the wattmeter 72. It is an expression.

Ymap3j (i) = (Ymap3j (i-1) + Ymap3j (i-2) + L3j (i)) / 3 (13) Here, MAP3 = table (X: 1, 2,..., 24) , Y: Ymap301, Ymap302,..., Ymap324) (14).

That is, when the power consumption (L3j (i)) at the j-th day on the ith day is detected, the detected value and MAP3
(I-1) daily j hour data (Ymap3j (i-
1)) and the average value of “i−2” daily j-hour data (Ymap3j (i−2)) in MAP3 to obtain i-th daily j-hour data (Ymap3j (i)), MAP3 is newly stored as j-time data (Ymap3j) which is used when MAP3 is referred to when performing an operation to be described later for determining the reformed fuel amount.

Here, the power consumption (L3j (i)) at the j-th day on the ith day is a value detected by the wattmeter 72 as described above, but in the fuel cell device 10 of this embodiment, The value is obtained as an integrated average value of the power consumption detected continuously during the i-th day and j hours. The formula for calculating the power consumption (L3j (i)) at the jth hour on the ith day is shown below.

L3j (i) = (Σ (W3j × ΔH3)) / H3 (15) where, W3j: power value [kW] for each sample time ΔH3: sample time, for example, 1 [sec] H3: one hour Total time, for example, 60 × 60 [s
ec].

As described above, as the power consumption at each time, the power consumption value detected by the wattmeter 70 is read every sample time (one second), and the integrated value is multiplied by the sample time for one hour. Subsequently, when integration for one hour is completed, the integrated value is added to the total time of one hour corresponding to the sample time (1 second since the sample time is one second).
The power consumption (L3j) for that time (time j) is obtained by dividing the time by the length expressed in seconds. In the above equation (15), the sample time is set to one second, but a different value may be selected as described above.

A unit time constituting one cycle (for example, MAP
1 for one month), the measured power consumption
Fluctuations due to different cycles (fluctuations with one week as one cycle or 1
Fluctuations with one cycle per day) and other various factors. However, by integrating and averaging the actually measured values during the unit time and obtaining the power consumption (for example, L1j) corresponding to the unit time, the influence of factors other than the target cycle is reduced, and the required power consumption is reduced. (L
The value of 1j) indicates a predetermined tendency for each unit time and is a value indicating a predetermined periodicity. As described above, in the present embodiment, the integrated average value of the power consumption is calculated based on the actually measured value of the power consumption of the household electric load 80 for each unit time according to each map, so that the measured value of the power consumption is , A numerical value indicating the desired periodicity is obtained (the component indicating the desired periodicity is extracted).

(2-3) Example of actual operation: Hereinafter, a map storing data indicating such periodicity is used to supply the reformer 24 in the fuel cell device 10 of the present embodiment. The operation for determining the reformed fuel amount will be described.
In the present embodiment, an estimated value of power consumption is obtained based on the periodicity when the load fluctuates with reference to MAP1 to MAP3, and the reformed fuel amount is calculated from the estimated power consumption. That is, in the present embodiment, the reformed fuel amount is determined by feedforward control of estimating power consumption. FIG. 6 is a flowchart showing a reformed fuel amount determination processing routine executed in control unit 50. The reformed fuel amount determination processing routine is executed by the control unit 50 at predetermined time intervals when the fuel cell device 10 is started.

When the reforming fuel amount determination processing routine is executed, first, time information is input (step S100). That is, prior to referring to the above-described map, the current time information (information relating to the month, day of the week, and time) is input. Specifically, Xff1, Xff2, and Xff3 at the current time are input. . This is performed by referring to an internal clock (not shown) provided in the control unit 50.

Next, based on the time information input in step S100, MAP1 to MAP3 are referenced (based on the equations (4) to (6)), and the current time (Xff1, Xff
ff2, Xff3), Uff1 determined based on the annual cycle, Uff2 determined based on the weekly cycle, and Uff3 determined based on the circadian cycle are determined (steps S110 to S130). Here, the learning of each map described above is executed separately and in parallel with the reforming fuel amount determination processing routine.
In 110 to S130, the latest map corrected (updated) by this learning operation is referred to.

Next, Uff4, which is the power consumption obtained based on the history of the power consumption in the past several minutes, is determined (step S140). The above Uff1 to Uff3 are values obtained based on the periodicity shown when the load fluctuates, and the actual power consumption of the home electric load 80 fluctuates in the past by performing the learning described above. It can be said that it is determined based on the history. In this embodiment,
As described above, based on the history of the fact that the power consumption of the home electric load 80 has actually fluctuated in the past, the home electric load 8
Although power consumption of 0 is predicted, in addition to the above Uff1 to Uff3 obtained based on the periodicity when the power consumption fluctuates as past history of power consumption, the past several minutes (in this embodiment, Uff4 obtained from the history of power consumption for the past two minutes) is further used. The equation for determining Uff4 based on the power consumption history for the past two minutes is given by (16)
Shown as an expression.

Uff4 [kW] = (L4 (i) + L4 (i-1) + L4 (i-2) +... + L4 (i-5)) / 6 (16)

Here, L4 (i) to L4 (i-5) represent the measured values of the power consumption detected by the wattmeter 70 every 20 seconds, and the average value of the 6 measured values detected every 20 seconds. That is, the average value of the values detected over the past two minutes every 20 seconds is defined as Uff4. Of course, a time other than 2 minutes may be selected, and the power consumption may be detected at intervals other than every 20 seconds. It suffices if the state of power consumption during the past fixed time, which is close to the present, can be reflected. Further, the value of Uff4 is determined in step S14.
It may be obtained each time when 0 is executed.
In step S140, it is determined always by executing processing separate from the reforming fuel amount determination processing routine.
Then, the value of Uff4 obtained at that time may be referred to.

Next, based on the values of Uff1 to Uff4, the power consumption in the home electric load 80 is estimated (step S150). An equation for calculating the estimated value (Uest) of the power consumption is shown below as equation (17).

Uest [kW] = α × (Uff1 + Uff2 + Uff3) / 3 + (1−α) × Uff4 (17) Here, α is a control parameter satisfying 0 <α <1.

Equation (17) indicates that the home electric load 80 is 1
The past two minutes, reflecting all of the following: showing the periodicity with one cycle of the year, showing the periodicity with one cycle of the week, and showing the periodicity with one cycle of the day Household electrical load 8
This is an equation for estimating power consumption of 0. Here, in the first half of the above equation (17), the sum of Uff1 to Uff3 is divided by 3, so that when predicting power consumption, the three types of periodicity are equally reflected. But
By providing different control parameters, it is also possible to vary the degree of reflecting each periodicity when estimating power consumption. Further, as described above, α is a control parameter having a value between 0 and 1, and by using this value, it is possible to adjust the degree to which the tendency that power consumption has fluctuated in the past several minutes is reflected. As described above, the power consumption of the home electric load 80 is predicted using Uff4 based on the fluctuation of the power consumption in the past several minutes, and the amount of reformed fuel supplied to the fuel cell device 10 is calculated. The power generation amount can smoothly follow the fluctuation of the electric load 80 in units of several minutes. However, as the degree to which the power consumption fluctuates in the past few minutes is increased, the effect of sudden power fluctuations that are not significantly related to the periodicity becomes stronger. In order to stabilize the control operation, it can be said that it is preferable that the value of α be large.

Next, based on the estimated power consumption, the amount of reformed fuel to be supplied, that is, the target flow rate Frk [mol / s] of the city gas supplied to the reformer 24 is calculated (step S160). . Here, first, based on the power consumption of the domestic electric load 80 estimated in step S150, the current value Ifc output when the fuel cell 40 performs power generation corresponding to the estimated power consumption is calculated by the following (18). It is calculated based on the formula.

Ifc [A] = Kdcac × Uest / Vfc (18) where Kdcac is a constant including the conversion efficiency of the DC-AC inverter 70, and Vfc [V] is the output voltage of the fuel cell 40.

As the output voltage value Vfc of the fuel cell 40, an actually measured value obtained by detecting the output voltage value of the fuel cell 40 using a voltage sensor may be used.
Approximately set values can also be used. next,
Using the output current value Ifc of the fuel cell 40, the amount of hydrogen Fh required by the fuel cell 40 to output this current value from the fuel cell 40 is calculated. The electrochemical reaction that proceeds in the fuel cell 40 is shown in the equations (1) to (3). The required amount of hydrogen Fh can be obtained as follows using the equation (1).

Fh [mol / s] = Ifc × Kfch / (2 × F) (19) where F: Faraday constant, Kfch: reciprocal of hydrogen utilization. Note that the hydrogen utilization rate is a value obtained as (amount of hydrogen actually involved in power generation) / (amount of hydrogen supplied to the anode side of the fuel cell). Not all of the hydrogen supplied to the fuel cell 40 is used for the electrochemical reaction. By performing the above calculations, the flow rate of hydrogen to be supplied to the fuel cell 40 to output a desired amount of current Can be requested.

In the present embodiment, the hydrogen to be supplied to the electrochemical reaction is generated from the city gas by the steam reforming reaction in the reforming section 24. Is shown below.

CH ₄ + 2H ₂ O → 4H ₂ + CO ₂ (20)

The flow rate Fm of methane required to generate the required amount of hydrogen obtained by the above equation (19) by the steam reforming reaction in the reforming section 24 is as follows from the equation (20). .

Fm [mol / s] = Fs / 4 (21)

Therefore, in the fuel cell device 10,
The target flow rate Frk of the city gas supplied to the reforming unit 24 via the temperature raising unit 20 can be calculated as follows.

Frk [mol / s] = Km2k × Fm (22) Here, Km2k is a coefficient for correcting the amount of nitrogen mixed at a fixed rate into natural gas used as city gas.

Note that the above equation (21) is based on the premise that all of the hydrogen supplied to the fuel cell 40 is generated by a steam reforming reaction.
In the case of performing the partial oxidation reaction in the above, the necessary flow rate Fm of methane may be determined by further considering the partial oxidation reaction of methane, the ratio of the steam reforming reaction and the partial oxidation reaction.

Thus, in step S160,
After calculating the target flow rate Frk of the city gas as the reformed fuel amount, next, in the present embodiment, the phase advance correction is performed on the target flow rate Frk (step S170). In the present embodiment, when estimating the power consumption of the home electric load 80, as described in step S140 and step S150, the history of the power consumption of the home electric load 80 in the past several minutes is reflected, Thus, even when the power consumption of the home electric load 80 fluctuates in a unit of several minutes, the power generation amount of the fuel cell 40 can follow the power consumption. In, for example, after city gas is supplied to the fuel cell device 10, this gas passes through the inside of the fuel cell device 10 and is subjected to a reforming reaction, and a desired amount of hydrogen generated by the reforming reaction is It takes a predetermined time until the fuel cell 40 is actually supplied to the fuel cell 40, and there is a possibility that a delay may occur until a desired amount of hydrogen is supplied to the fuel cell 40 and a desired amount of current is output. If the delay occurring until the desired amount of power is generated becomes a problem, step S1 is performed.
The phase advance correction shown as 70 may be performed. An equation for performing phase lead correction on the flow rate target value Frk and calculating the corrected city gas flow rate target value F'rk is shown below. Here, a delay occurring between the supply of city gas to the fuel cell device 10 and the output of power from the fuel cell device 10 is treated as a temporary delay element.
The control law is described by the transfer function expression.

F′rk [mol / s] = {(T1 × S + 1) / (T2 × S + 1)} × Frk (23) where T1: time constant of the fuel cell device 10, T2: fuel cell device 10 Represents a sufficiently fast time constant (usually 30 times or more) as compared with.

In order to obtain a desired output from the fuel cell 40, the city gas having a flow rate corresponding to the target value F'rk calculated as described above may be supplied to the reforming unit 24. Thus, a command value Vkfc (drive signal) is output to the flow control valve 32 so that city gas having a flow rate corresponding to the target value F'rk is supplied through the gas flow path 60.
Here, in the control unit 50, the amount of city gas passing through the gas flow path 60 and the flow control valve 32 for realizing this.
The relationship with the command value to be output is stored in advance,
As the gas flow rate increases, it is difficult to precisely control the flow rate by the flow control valve 32. That is, the amount of reformed fuel supplied (the amount of city gas)
Increases, the internal pressure increases in the reforming section 24 and also in the gas passage 60 communicating therewith,
Such an increase in pressure may make precise flow control in the flow control valve 32 difficult because the city gas is a compressible fluid. Therefore, in the present embodiment, the flow rate sensor 36 is provided in the gas flow path 60, the amount of city gas actually passing through the gas flow path 60 is detected, and the feedback control is performed on the command value output to the flow control valve 32. Then, the command value output to the flow control valve 32 is corrected (step S180), so that the amount of city gas actually supplied to the reforming unit 24 does not deviate from the target value F'rk.

Vkfc [V] = Vkfc0 + Kp × (F′rk−Fk) + Ki × Σ (F′rk−Fk) (24) where Kp, Ki: parameters for feedback control, Vkfc: initial feedforward value , Fk: The city gas flow rate measured by the flow rate sensor 36. The initial feedforward value is a command value output to the flow control valve 32 before performing the above-described correction, corresponding to the target value F'rk of the city gas flow rate.

In the present embodiment, when performing the feedback control, the flow rate Fk of the city gas flowing through the gas flow path 60 when the flow rate control valve 32 is driven based on the command value Vkfc0 (initial feed forward value). And the target value F'rk
The known PI control is performed based on the deviation from the above.
Thus, the target value F'rk of the city gas flow rate and the actual measurement value Fk
By correcting the command value based on the deviation from the above, a desired amount of city gas is supplied to the reforming unit 24 even when the pressure of the city gas increases and an error occurs in the operation of the flow control valve 32. It becomes possible. When the command value is corrected in step S180, the command value Vkfc to be output to the flow control valve 32 is determined (step S190), and this routine ends.

According to the fuel cell device 10 of the present embodiment configured as described above, the home electric load 8 is controlled based on the periodicity when the power consumption of the home electric load 80 fluctuates.
In order to predict power consumption of 0 and determine the amount of city gas to be supplied to the reforming unit 24, the electric power generated in the fuel cell 40 using hydrogen obtained by reforming the supplied city gas and the household electric load The difference between the actual power consumption at 80 and the actual power consumption can be made smaller. Therefore, it is possible to further reduce the amount of power generated as excessive power that is sold to an external power company or stored using power storage means. Alternatively, the power to be purchased from an external power company as the power shortage can be reduced. As a result, the fuel cell device 10 can sufficiently secure the effect as a power source for small-scale cogeneration. Further, when determining the amount of city gas to be supplied, the actual power consumption of the household electric load 80 and the fuel cell 40
By eliminating the need for feedback control performed by calculating the deviation from the actually generated power, the control operation can be further stabilized. That is, when feedback control is performed using the deviation between the power consumption of the load and the generated power, hunting may occur when the load fluctuates greatly, and the control may become unstable. Can be avoided.

In the above embodiment, the home electric load 8
The operation of estimating the power consumption of the home electrical load 80 is represented by a periodicity (a periodicity of one year, a periodicity of one week, and a periodicity of one week). Day one
(Periodicity as a period), and the prediction can be performed with high accuracy. Of course, it is not necessary to reflect all these periodicities, and if the power consumption of the home electric load 80 is predicted based on at least one of the periodicities, a predetermined effect of improving the prediction accuracy can be obtained. it can. Further, depending on the nature of the load to which the fuel cell device 10 supplies power, the magnitude of the load may be predicted by focusing on periodicity different from the above-described three types of periodicity. Even in such a case, by predicting the magnitude of the load based on the periodicity shown when the power consumption fluctuates, the same effect that the accuracy of the prediction is improved can be obtained.

Further, in this embodiment, when predicting the power consumption of the load based on the periodicity, the power consumption is predicted based on the detected value while detecting the actual power consumption of the load. The data on the periodicity used in the above is corrected. As described above, by correcting the data related to the periodicity based on the history (measured value detected by the sensor) in which the power consumption of the load fluctuates in the past, the content of the data related to the periodicity becomes more realistic. And the accuracy of prediction can be improved. In the above-described embodiment, the learning operation (map correction operation) of the data related to the periodicity is determined by averaging the current detection value and the past two map data ((7)).
The learning may be performed by different operations, such as using the equations, (10) and (13)), and using map data other than the past two times. Here, when performing the learning operation, it is possible to correct the map data by calculating the average of the current detection value and the past detection value. By calculating the average of the detected value and the past map data, it is possible to suppress the influence when the power consumption changes suddenly.

The history (measured value detected by the sensor) in which the power consumption of the load fluctuates in the past as described above is as follows.
In addition to the data related to periodicity, the power consumption in the past few minutes is further reflected. Therefore, the amount of city gas supplied to the reforming unit 24 can be made to follow to some extent even a load change in units of several minutes, and the amount of power generation in the fuel cell 40 can be made closer to a desired state. . In the above embodiment, the history of the past two minutes is used as the history of the power consumption fluctuating in the past, but histories of different lengths may be used. When estimating the power consumption of the household electric load 80 based on the periodicity indicated when the power consumption of the load fluctuates, a unit time (for example, one day equals one day) constituting one cycle in the periodicity used for the prediction By using a past history that is sufficiently shorter than (one hour, which is a unit time in the periodicity), it is possible to sufficiently obtain the effect of improving the accuracy of predicting power consumption.

When determining the amount of city gas to be supplied to the reforming unit 24 based on the predicted power consumption of the load,
By performing the phase advance correction as described above, a delay occurs between the supply of the city gas to the reforming unit 24 and the supply of a desired amount of hydrogen to the fuel cell 40 as a property of the fuel cell device 10. In a case where there is a possibility of occurrence, such a delay can be suppressed. In particular, as in the present embodiment, in addition to the periodicity of one cycle such as one year, one week, or one day, the prediction of the power consumption of the load is reflected by reflecting the history of the power consumption fluctuation in the past several minutes. Is performed, even when the power consumption fluctuates in units of several minutes, by performing the phase lead correction, the fuel cell 40 can be quickly operated without causing an undesired delay with respect to the load fluctuation. The amount of generated power can be followed, and the effect of predicting power consumption by reflecting the history of fluctuations in power consumption in the past several minutes can be more sufficiently ensured.

Further, a feedback control is performed by obtaining a deviation between the amount determined as the amount of city gas to be supplied to the reforming unit 24 and the amount of gas actually supplied to the reforming unit 24 based on this determination. Therefore, a desired amount of city gas is supplied to the reforming unit 2
4 can be improved in the accuracy of the operation. The operation of such feedback control is for compensating the accuracy of the operation of the members constituting the fuel cell device 10, and is based on the magnitude of the load actually measured when estimating the magnitude of the load. Since the feedback control is different from the feedback control performed based on the above, there is no possibility that the above-described inconvenience such as hunting occurs.

Further, when the magnitude of the load is predicted based on the periodicity shown when the power consumption fluctuates, in the above embodiment, the power consumption of the entire home electric load 80 is considered.
A map was created for each cycle, and the average (power consumption) of the household electrical load 80 was predicted by averaging the respective power consumption values obtained by referring to these maps. The periodicity indicated by the load fluctuation may be reflected by a different method. For example, in each of the loads constituting the domestic electric load 80, at least a part of the load has a load showing a periodicity mainly with one year as one cycle and a periodicity mainly with one week as one cycle. If it is possible to classify the load into loads that show periodicity with one cycle as one day, the total power consumption for each of the classified loads is separately calculated based on the periodicity that each shows. The total power consumption of the home electric load 80 may be predicted by summing the predicted power consumption. If the size of the home electric load 80 is predicted based on the periodicity when the power consumption fluctuates,
Similar effects can be obtained.

In the above embodiment, city gas (natural gas) is used as the commercial gas. However, a desired amount can be easily used, and the stationary fuel cell device is used for producing hydrogen. As long as the fuel can be used as a reforming fuel, another kind of fuel may be used.

In the above-described embodiment, the configuration of the fuel cell device 10 shown in FIG. 1 is described as the configuration of the fuel cell device. However, the present invention may be applied to a fuel cell device having a different configuration. A similar effect can be achieved with a system for reforming gas. For example, in a fuel cell device, a hydrogen separation device using a hydrogen separation membrane made of palladium or the like is provided, and hydrogen is extracted from a reformed gas obtained by reforming a commercial gas using the hydrogen separation device. The extracted hydrogen may be supplied to the fuel cell. The present invention can be applied to any configuration in which hydrogen is generated by reforming commercial gas and hydrogen is supplied to the fuel cell in an amount corresponding to the amount of commercial gas used for the reforming reaction.

Further, in the above embodiment, a polymer electrolyte fuel cell is used as the fuel cell 40, but the same effect can be obtained when another type of fuel cell is used.

Further, in the above embodiment, the fuel cell device 1
0 indicates that power is supplied to the home electric load 80, but power may be supplied to different types of loads. For example, apartments and offices (buildings), or stores such as convenience stores,
It can be applied to various types of cogeneration power supplies, such as supplying power to individual facility loads, and based on the periodicity of the power consumption of these loads, The same effect can be obtained by estimating the size of the fuel and determining the amount of reformed fuel to be supplied to the reformer.

The embodiments of the present invention have been described above.
The present invention is not limited to such embodiments at all, and it goes without saying that the present invention can be implemented in various modes without departing from the gist of the present invention.

[Brief description of the drawings]

FIG. 1 shows a fuel cell device 1 according to a preferred embodiment of the present invention.
FIG. 2 is an explanatory diagram showing a configuration of a zero.

FIG. 2 is an explanatory diagram showing a state of connection between a fuel cell 40 and a domestic load.

FIG. 3 is an explanatory diagram illustrating an example of a periodicity in a household electrical load, with one year as one cycle.

FIG. 4 is an explanatory diagram showing an example of a periodicity in a household electrical load, where one cycle is one week.

FIG. 5 is an explanatory diagram illustrating an example of a periodicity in a domestic load with one day as one cycle.

FIG. 6 is a flowchart illustrating a reformed fuel amount determination processing routine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Fuel cell device 20 ... Heating part 21 ... Heat exchange part 22 ... Combustion part 23, 25, 27, 28 ... Blower 24 ... Reforming part 26 ... CO oxidation part 30, 32, 34 ... Flow control valve 36, 38 ... Flow sensor 40 ... Fuel cell 50 ... Control unit 60,61,63,64 ... Gas flow path 62 ... Steam flow path 65 ... Fuel gas flow path 66 ... Oxidizing gas flow path

Continued on the front page F term (reference) 5H026 AA06 CX03 CX04 CX05 EE02 EE05 EE08 EE19 5H027 AA06 BA01 BA09 BA16 BA17 DD03 DD05 KK21 KK25 KK31 KK51 KK52 KK54 KK56 MM01 MM08 MM09 MM21

Claims (14)

[Claims] 1. A stationary fuel cell apparatus including a fuel cell for supplying electric power to a specific load, comprising: a reformer that receives a supply of a commercial gas to advance a reforming reaction to generate hydrogen. A reformed fuel supply unit that supplies the commercial gas to the reformer, a hydrogen supply unit that supplies the hydrogen generated by the reformer to the fuel cell, and a power consumption of the specific load. A reformed fuel amount determining means for determining an amount of the commercial gas to be supplied to the reformer based on the periodicity when the fuel gas fluctuates. The fuel cell device according to claim 1, wherein the commercial gas is supplied to the reformer according to the amount of the commercial gas determined by the determining unit. 2. The method according to claim 1, wherein the reforming fuel amount determining unit determines a periodicity when the power consumption of the specific load varies, a periodicity of one cycle per year, and a periodicity of one week as one cycle. 2. The fuel cell device according to claim 1, wherein the amount of the commercial gas is determined based on at least one of periodicity and periodicity with one day as one cycle. 3. 3. The fuel cell device according to claim 1, further comprising: a power consumption detecting unit configured to detect a magnitude of an actual power consumption at the specific load, wherein the reformed fuel amount determining unit includes: In addition to the periodicity, the amount of the commercial gas to be supplied to the reformer is further determined based on the magnitude of power consumption at the specific load detected by the power consumption detection means during a past fixed time. A fuel cell device characterized by determining. 4. The fuel cell device according to claim 1, further comprising: a power consumption detecting unit configured to detect a magnitude of an actual power consumption at the specific load, wherein the reformed fuel amount determining unit includes: A storage unit that stores information about the periodicity; and a period information correction unit that corrects the information about the periodicity stored in the storage unit based on the magnitude of the actual power consumption detected by the power consumption detection unit. A fuel cell device, wherein the commercial gas amount is determined with reference to the information on the periodicity stored in the storage unit and corrected by the periodic information correction unit. 5. A stationary fuel cell apparatus including a fuel cell for supplying electric power to a specific load, wherein the reformer receives a supply of a commercial gas to advance a reforming reaction to generate hydrogen. A reformed fuel supply unit that supplies the commercial gas to the reformer; a hydrogen supply unit that supplies the hydrogen generated by the reformer to the fuel cell; The commercial gas to be supplied to the reformer so that the fuel cell can generate the predicted power consumption based on the history of the fluctuation of the power consumption of the specific load. A reformed fuel amount determining means for determining the amount of the reformed fuel, wherein the reformed fuel supply means determines the amount of the commercial gas with respect to the reformer according to the amount of the commercial gas determined by the reformed fuel amount determining means. Fuel cell characterized by supplying Apparatus. 6. The reforming fuel amount determining means includes first correcting means for performing a phase lead correction when determining the amount of the commercial gas to be supplied to the reformer. The fuel cell device according to any one of the above. 7. The fuel cell device according to claim 1, wherein the reformed fuel supply unit detects an amount of the commercial gas actually supplied to the reformer. The reformed fuel supply means, when supplying the commercial gas according to the amount of the commercial gas determined by the reformed fuel amount determination means, the reformed fuel amount determination means determined in the past The reformer is actually supplied to the reformer based on the difference between the amount of the commercial gas and the amount of the commercial gas actually supplied by the reformed fuel supply unit and detected by the supplied gas amount detection unit. A fuel cell device comprising a second correction unit for correcting the amount of the commercial gas. 8. A method of operating a stationary fuel cell device including a fuel cell for supplying electric power to a specific load, comprising: (a) periodicity when power consumption of the specific load fluctuates; Determining the amount of commercial gas to be subjected to a reforming reaction for producing hydrogen to be supplied to the fuel cell, based on the above, and (b) converting the commercial gas according to the determination in step (a). Operation of a fuel cell device, comprising: providing hydrogen to the fuel cell as a fuel gas by supplying the hydrogen produced by the reforming reaction to the fuel cell as a fuel gas. Method. 9. The step (a) includes, as the periodicity indicated when the power consumption of the specific load fluctuates, a periodicity of one cycle per year and a periodicity of one cycle per week. The method according to claim 8, wherein the amount of the commercial gas is determined based on at least one of periodicity of one cycle per day. 10. The method for operating a fuel cell device according to claim 8, further comprising: (d) detecting a magnitude of an actual power consumption at the specific load, wherein the (a) step is performed. Determines, in addition to the periodicity, the amount of the commercial gas to be subjected to the reforming reaction, based on the magnitude of the power consumption at the specific load detected in the step (d) during the past certain time in addition to the periodicity. A method for operating a fuel cell device, characterized by determining. 11. The operating method for a fuel cell device according to claim 8, wherein (d) detecting a magnitude of actual power consumption at the specific load, and (e) relating to the periodicity. A step of correcting the information on the periodicity stored in the storage unit based on the magnitude of the actual power consumption detected in the step (d). The method of operating the fuel cell device, wherein the step of determining the amount of the commercial gas is performed by referring to the storage unit that stores the information on the periodicity corrected in the step (e). 12. A method of operating a stationary fuel cell apparatus including a fuel cell for supplying electric power to a specific load, comprising: (a) a history in which actual power consumption of the specific load in the past has fluctuated; Based on the power consumption of the specific load, and the predicted power consumption should be subjected to a reforming reaction for generating hydrogen to be supplied to the fuel cell so that the fuel cell can generate the fuel cell. Determining the amount of commercial gas; (b) subjecting the commercial gas to the reforming reaction in accordance with the determination in step (a) to generate hydrogen from the commercial gas; Supplying the hydrogen generated by the reaction to the fuel cell as a fuel gas. 13. The fuel according to claim 8, wherein in the step (a), a phase lead correction is performed when determining an amount of the commercial gas to be subjected to the reforming reaction. How to operate the battery device. 14. The method for operating a fuel cell device according to claim 8, further comprising a step (f) of detecting an amount of the commercial gas actually supplied to the reforming reaction. The step (b) is performed when the commercial gas is subjected to the reforming reaction according to the determination in the step (a);
The difference between the amount of the commercial gas determined in the past when the step (a) was executed and the amount of the commercial gas actually supplied in the step (b) and detected in the step (f) in accordance therewith A method of operating the fuel cell device, wherein the amount of the commercial gas actually supplied to the reforming reaction is corrected based on the following.