Management device, management method, and fuel cell system

Abstract

A management device according to the present invention manages a power generation device having: a first fuel cell that generates power by causing a part of hydrogen contained in a fuel containing the hydrogen and a hydrocarbon to react; and a second fuel cell that generates power by causing the hydrogen discharged from the first fuel cell to react. The management device has a management unit that manages the operation of the first fuel cell so that a reforming reaction of the hydrocarbon is performed in the first fuel cell.

Description

Control device, control method, and fuel cell system

[0001] The present invention relates to a control device, a control method, and a fuel cell system.

[0002] To reduce carbon dioxide emissions, in addition to power generation using renewable energy sources such as solar, wind, hydroelectric, and geothermal power, the use of clean energy that does not emit carbon dioxide is attracting attention, and one such example is fuel cells. Fuel cells use hydrogen and oxygen as fuel, and electricity can be generated by the reaction of these two fuels. By using renewable energy to generate the electricity for hydrogen production, clean energy that does not emit carbon dioxide can be obtained. For this reason, various developments are being made regarding fuel cells, and the development of fuel cell systems that use hydrocarbons as a fuel source to generate electricity is progressing.

[0003] As a fuel cell system that generates electricity using fuel cells, for example, a dual-temperature controlled linked solid oxide fuel cell has been disclosed, which is configured by linking a low-temperature operating solid oxide fuel cell and a high-temperature operating solid oxide fuel cell (see, for example, Patent Document 1).

[0004] In this dual-temperature controlled linked solid oxide fuel cell, iron / yttrium-stabilized zirconia (Fe / YSZ) is used as the fuel electrode for the low-temperature operating solid oxide fuel cell, and nickel / yttrium-stabilized zirconia (Ni / YSZ) is used for the high-temperature operating solid oxide fuel cell. In the low-temperature operating solid oxide fuel cell, the operating temperature is set to approximately 800-950°C, and methane is burned as a hydrocarbon fuel to perform a partial oxidation reaction of the hydrocarbon fuel and generate electricity. In the high-temperature operating solid oxide fuel cell, the operating temperature is set to approximately 950-1050°C, and the reaction product gas, mainly composed of carbon monoxide and hydrogen, that flows out from the reaction system of the low-temperature operating solid oxide fuel cell is burned as fuel to perform an oxidation reaction and generate electricity.

[0005] Japanese Patent Application Publication No. 2000-268832

[0006] However, as in the technology described in Patent Document 1, if the operating temperature inside the fuel cell is increased, and if the fuel contains trace amounts of hydrocarbons such as toluene, carbon deposition (coking) occurs inside the fuel cell, reducing the power generation efficiency and output of the fuel cell. Therefore, it is important to manage the operation of the fuel cell system so that power generation can be performed while suppressing coking and maintaining high operating efficiency.

[0007] One aspect of the present invention aims to generate electricity while suppressing coking and maintaining high operating efficiency.

[0008] One aspect of the present invention is a control device for managing a power generation apparatus having a first fuel cell that generates electricity by reacting a portion of the hydrogen contained in a fuel containing hydrogen and hydrocarbons, and a second fuel cell that generates electricity by reacting the hydrogen discharged from the first fuel cell, the control device having a control unit that manages the operation of the first fuel cell so that the hydrocarbon reforming reaction is carried out in the first fuel cell.

[0009] One aspect of the present invention is a management method for managing a power generation apparatus having a first fuel cell that generates electricity by reacting a portion of the hydrogen contained in a fuel containing hydrogen and hydrocarbons, and a second fuel cell that generates electricity by reacting the hydrogen discharged from the first fuel cell, the management method including a management step of managing the operation of the first fuel cell so that the hydrocarbon reforming reaction is carried out in the first fuel cell.

[0010] One aspect of the present invention is a fuel cell system comprising: a power generation device having a first fuel cell that generates electricity by reacting a portion of the hydrogen contained in a fuel containing hydrogen and hydrocarbons; a second fuel cell that generates electricity by reacting the hydrogen discharged from the first fuel cell; and a control device that manages the operation of the power generation device, wherein the control device manages the operation of the first fuel cell so that the hydrocarbon reforming reaction is carried out in the first fuel cell.

[0011] One aspect of the present invention enables power generation while suppressing coking and maintaining high operating efficiency.

[0012] This is a schematic diagram showing the general configuration of a fuel cell system equipped with an organic hydride production apparatus according to an embodiment of the present invention. This is an explanatory diagram showing an example of the relationship between coking generation in a fuel cell and power density when fuel gas is supplied to the fuel cell to generate electricity. This is a diagram showing an example of a state in which the second fuel cell is positioned to easily receive heat from the first fuel cell. This is a diagram showing an example of another fuel cell configuration. This is a diagram explaining the fuel utilization rate. This is a block diagram showing an example of a computer hardware configuration. This is a flowchart showing an example of a management method according to an embodiment of the present invention. This is a flowchart explaining an example of the first management process. This is a flowchart explaining an example of the second management process.

[0013] Hereinafter, embodiments of the present invention (hereinafter simply referred to as "these embodiments") will be described in detail. For ease of understanding, the same reference numerals are used for identical components in each drawing, and redundant explanations are omitted. In this specification, the "~" indicating a numerical range means that the values ​​before and after it are included as the lower and upper limits, respectively, unless otherwise specified. Furthermore, if only the upper limit of a numerical range represented by "~" has a unit specified, it means that the lower limit also has the same unit.

[0014] The management device according to this embodiment is a management device for managing a power generation device having a first fuel cell that generates electricity by reacting a portion of the hydrogen contained in a fuel containing hydrogen and hydrocarbons, and a second fuel cell that generates electricity by reacting the hydrogen discharged from the first fuel cell, and includes a management unit that manages the operation of the first fuel cell so that the hydrocarbon reforming reaction is carried out in the first fuel cell.

[0015] The control device according to this embodiment manages the operation of the first fuel cell in a power generation device having a first fuel cell and a second fuel cell, so that the fuel supplied to the fuel electrode of the first fuel cell undergoes a reforming reaction of hydrocarbons contained in the fuel. This makes it possible to remove hydrocarbons contained in the fuel (for example, organic hydrides and hydrides dehydrogenated from organic hydrides) in the first fuel cell. Then, when generating electricity in the second fuel cell by reacting the hydrogen contained in the fuel discharged from the first fuel cell, the operating temperature of the second fuel cell is set to a high temperature at which hydrocarbons contained in the fuel can be thermally decomposed, and at a temperature at which carbon deposition reactions of hydrocarbons (for example, organic hydrides and hydrides) occur. Even if the operating temperature of the second fuel cell is set to a temperature at which carbon deposition reactions of hydrocarbons occur, since the fuel supplied to the second fuel cell contains almost no hydrocarbons, it is possible to suppress the decomposition of hydrocarbons and coking at the fuel electrode of the second fuel cell. Therefore, the control device according to this embodiment can generate electricity while suppressing coking while maintaining high operating efficiency of the fuel cell.

[0016] The operating temperature refers to the temperature of the fuel cell cell and cell stack associated with the reaction that generates electricity within the fuel cell.

[0017] The management method according to this embodiment is a management method for managing a power generation device having a first fuel cell that generates electricity by reacting a portion of the hydrogen contained in a fuel containing hydrogen and hydrocarbons, and a second fuel cell that generates electricity by reacting the hydrogen discharged from the first fuel cell, and includes a management step of managing the operation of the first fuel cell so that the hydrocarbon reforming reaction is carried out in the first fuel cell.

[0018] The management method according to this embodiment, similar to the management device according to this embodiment described above, can generate electricity while suppressing coking and maintaining the high operating efficiency of the fuel cell.

[0019] The fuel cell system according to this embodiment includes a power generation device having a first fuel cell that generates electricity by reacting a portion of the hydrogen contained in a fuel containing hydrogen and hydrocarbons, and a second fuel cell that generates electricity by reacting the hydrogen discharged from the first fuel cell, and a control device that manages the operation of the power generation device, wherein the control device manages the operation of the first fuel cell so that the hydrocarbon reforming reaction is carried out in the first fuel cell.

[0020] Since the fuel cell system according to this embodiment has the same configuration as the control device according to this embodiment described above, it is possible to generate electricity while suppressing coking and maintaining the high operating efficiency of the fuel cell.

[0021] <Fuel Cell System> A fuel cell system equipped with a control device according to this embodiment will be described. Figure 1 is a schematic diagram showing the general configuration of a fuel cell system equipped with a control device according to this embodiment. As shown in Figure 1, the fuel cell system 1 comprises a fuel cell 10, an adjustment unit 20, a separation unit 30, a measurement unit 40, and a control device 50. In the fuel cell system 1, hydrogen (H) contained in the fuel gas G1 used as fuel in the fuel cell 10 ２ ) is used as a hydrogen source to generate electricity.

[0022] In this embodiment, fuel gas G1 is used as the fuel, but H ２ It may also be a fluid such as a liquid containing [a specific substance].

[0023] Fuel gas G1 is supplied to the fuel cell 10, H ２ An example of a transport fluid containing H, which is obtained by the dehydrogenation reaction of an organic hydride. ２ These include gases containing trace amounts of hydrogenates, reformed LPG gas, or hydrogen-containing gases derived from biomass.

[0024] Examples of hydrocarbons include organic hydrides and hydrides obtained by the dehydrogenation reaction of organic hydrides. The reaction temperature that can occur in the fuel cell 10 is, for example, at most about 1000°C. In this embodiment, hydrocarbons refer to hydrocarbons that exhibit a carbon deposition reaction at most about 1000°C, and specifically refer to hydrocarbons such as organic compounds with two or more carbon atoms. Therefore, CH4, which has one carbon atom, is also included. ４ These are not included in the hydrocarbons in this embodiment.

[0025] Organic hydrides are organic compounds in which hydrogen is bonded through a hydrogen reaction of the hydride. Cycloalkane derivatives can be used as organic hydrides. Cycloalkane derivatives are compounds having a monocyclic structure composed of three or more single bonds between carbon atoms. Some or all of the hydrogen atoms of the carbon atoms forming the ring of the compound may be substituted with substituents. The substituents are preferably alkyl groups having 1 to 5 carbon atoms. Examples of substituents include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl groups.

[0026] Examples of cycloalkane derivatives include methylcyclohexane (hereinafter sometimes referred to as "MCH"), dimethylcyclohexane, 1,3,5-trimethylcyclohexane, decalin, methyldecalin, and tetradekahydroanthracene. Among these, methylcyclohexane is preferred as the cycloalkane derivative. Since methylcyclohexane is a liquid with properties similar to petroleum, using methylcyclohexane as fuel allows for the utilization of existing petroleum infrastructure.

[0027] The dehydrogenated product is an organic compound from which hydrogen has been eliminated via the dehydrogenation reaction of an organic hydride. For example, an aromatic hydrocarbon compound containing at least one aromatic ring can be used as the dehydrogenated product. Examples of aromatic hydrocarbon compounds include benzene, alkylbenzene, naphthalene, alkylnaphthalene, anthracene, and diphenylethane, among others. Alkylbenzene may include compounds in which 1 to 4 hydrogen atoms on the aromatic ring are substituted with linear or branched alkyl groups having 1 to 6 carbon atoms. Examples of such compounds include toluene (hereinafter sometimes referred to as "TOL"), xylene, mesitylene, ethylbenzene, and diethylbenzene, among others. Alkylnaphthalene includes compounds in which 1 to 4 hydrogen atoms on the aromatic ring are substituted with linear or branched alkyl groups having 1 to 6 carbon atoms. Examples of such compounds include methylnaphthalene, among others.

[0028] In the present embodiment, the fuel gas G1 is obtained by the dehydrogenation reaction of an organic hydride, and contains H ２ and a dehydrogenated product. The following description is provided on the assumption that the hydrocarbons are the organic hydride and the dehydrogenated product, the organic hydride is "MCH", and the dehydrogenated product is "TOL".

[0029] In a fuel cell system that generates power by using H ２ gas contained in fuel gas as a hydrogen source for a fuel cell, as shown in FIG. 2, when power is generated by supplying fuel gas containing H ２ gas into the fuel cell, it is necessary to set the operating temperature inside the fuel cell to a high level in order to increase the power generation amount. If the operating temperature of the fuel cell is set to a high temperature of, for example, 700° C. or higher to increase the power generation amount, then inside the fuel cell, the fuel gas contains H ２The thermal decomposition of hydrocarbons (e.g., MCH and TOL) contained in the gas progresses, making coking more likely. If the operating temperature of the fuel cell is set to a low temperature, for example, 500 to 700°C, to prevent coking from occurring inside the fuel cell, the current density will decrease and the power density will decrease (see Figure 2(a)). In contrast, as shown in Figure 2(b), in the fuel cell system 1, the operating temperature of the first fuel cell 10A in the fuel cell 10 is set to a low temperature, for example, 500 to 700°C. The first fuel cell 10A has a lower power density, but it can remove hydrocarbons (e.g., MCH and TOL) contained in the fuel gas G1. The fuel gas G2A discharged from the first fuel cell 10A is supplied to the second fuel cell 10B, and the operating temperature of the second fuel cell 10B is set to a high temperature, for example, 700°C or higher, to increase the current density and power density. Since the hydrocarbons contained in the fuel gas G1 supplied to the first fuel cell 10A are almost completely removed, even if the operating temperature of the second fuel cell 10B is set to a high temperature, it is possible to suppress the generation of coking caused by the hydrocarbons contained in the fuel gas G1 within the second fuel cell 10B, and to generate electricity with high efficiency within the second fuel cell 10B. Therefore, the control device according to this embodiment can generate electricity while suppressing the generation of coking while maintaining the operating efficiency of the fuel cell 10 at a high level.

[0030] [Fuel cell] The fuel cell 10 contains H in the fuel gas G1 ２ It generates electricity by reacting with H. The fuel cell 10 is supplied via the gas transport line L11. ２ A fuel gas G1 containing hydrocarbons is supplied. The fuel gas G1 may be supplied from, for example, a storage tank for storing fuel gas G1 (not shown).

[0031] Note that fuel gas G1 is H ２ It contains H as its main component and a small amount of hydrocarbons. ２ The content of is sufficient if it is 60 vol% or more. The hydrocarbon content is from fuel gas G1 to H ２ This is within the range of the amount excluding gas, for example, a few ppm or less.

[0032] The fuel cell 10 comprises a first fuel cell 10A and a second fuel cell 10B. The first fuel cell 10A and the second fuel cell 10B may each be composed of, for example, a stack which is an assembly of multiple cells, or a collection of multiple stacks.

[0033] The first fuel cell 10A will now be described. The first fuel cell 10A generates electricity by reacting a portion of the hydrogen contained in the fuel gas G1. Preferably, the first fuel cell 10A generates electricity by reacting hydrogen at an operating temperature below the thermal decomposition temperature at which organic hydrides and toluene, which are included in the fuel gas G1 as an example of hydrocarbons, thermal decompose.

[0034] The first fuel cell 10A can use a solid oxide fuel cell (hereinafter also referred to as "SOFC") that uses a high-temperature solid electrolyte. As the SOFC, an oxide ion conducting SOFC or a proton conducting SOFC can be used.

[0035] The first fuel cell 10A has a fuel cell cell 11A, which comprises a solid electrolyte 111A, a fuel electrode 112A, and an air electrode 113A, and fuel gas G1 is supplied to the fuel electrode 112A.

[0036] In the first fuel cell 10A, it is preferable to substantially reform at least one component of MCH and TOL, which are examples of hydrocarbons remaining in the fuel gas G1. This reduces the risk of coking.

[0037] In this embodiment, "substantially" means that it is acceptable if a minute amount of caulking is used that does not affect performance, and this includes cases where the entire amount is modified.

[0038] (Solid Electrolyte) ((Oxide Ion Conducting SOFC)) When the first fuel cell 10A is an oxide ion conducting SOFC, the solid electrolyte 111A is an oxide ion conductor.

[0039] Examples of oxide ion conductors include stabilized zirconia such as yttria-stabilized zirconia (YSZ), calcia-stabilized zirconia (CSZ), and scandia-stabilized zirconia (ScSZ). Oxide ion conductors may be used individually or in combination of two or more types.

[0040] ((Proton-conducting SOFC)) When the first fuel cell 10A is a proton-conducting SOFC, the solid electrolyte 111A is a proton conductor.

[0041] As for proton conductors, there is a perovskite-type structure (ABO ３ Examples include metal oxides having a phase, and metals included in the metal oxides include barium, zirconium, yttrium, cerium, praseodymium, scandium, gadolinium, and samarium. These may be used individually or in combination of two or more.

[0042] Specifically, as a proton conductor, BaZr ０．８５ Y ０．１５ O ３－δ (BZY15), BaZt ０．８０ Y ０．２ O ３－δ (BZY20), BaCe ０．８ Y ０．２ O ３－δ (BCY20), BaZr ０．１ Ce ０．７ Y ０．２ O ３－δ (BZCY20), Pr １．８ Ba １．２ Sc ２．０ O ７－δ Examples include (PBSc20) (where δ is the amount of oxygen vacancies).

[0043] (Fuel electrode) The fuel electrode 112A is provided facing one side of the solid electrolyte 111A and has a porous structure. In the fuel electrode 112A, H contained in the fuel gas G1 ２The gas reacts with oxide ions to produce water vapor and electrons.

[0044] As the fuel electrode 112A, a mixed sintered body of Ni metal and a metal oxide (Ni-based cermet) can be used. Examples of fuel electrode 112A include cermets of Ni and yttria-stabilized zirconia (YSZ), cermets of Ni and scandia-stabilized zirconia (SSZ), cermets of Ni and yttrium-doped ceria (YDC), cermets of Ni and samarium-doped ceria (SDC), and cermets of Ni and gadolinium-doped ceria (GDC).

[0045] As described above, the fuel electrode 112A has a porous structure, and the porosity of the fuel electrode 112A is such that MCH, TOL, and H contained in the fuel gas G1 are present inside the fuel electrode 112A. ２ It just needs to be large enough for gases and other liquids to pass through.

[0046] (Air electrode) The air electrode 113A is provided facing the other surface of the solid electrolyte 111A and has a porous structure. Air is supplied to the air electrode 113A from an air supply unit (not shown). In the air electrode 113A, oxygen in the air reacts with electrons to form oxide ions. Perovskite oxides can be used as the air electrode 113A. Examples of materials for the air electrode 113A include lanthanum strontium cobalt oxide (LSC), lanthanum strontium cobalt iron oxide (LSCF), and lanthanum strontium manganese oxide (LSM).

[0047] As described above, the air electrode 113A has a porous structure, but the porosity of the air electrode 113A only needs to be large enough to allow oxygen or oxide ions produced by the reaction of oxygen with electrons to pass through the inside of the air electrode 113A.

[0048] In the fuel cell cell 11A, when the solid electrolyte is an oxide ion conductor, the electrode reaction shown in formula (1) below occurs at the fuel electrode 112A, and the electrode reaction shown in formula (2) below occurs at the air electrode 113A. Overall, the reaction shown in formula (3) below occurs, producing water as a product. Electrode reaction occurring at fuel electrode 112A: H ２ +O２－ →H ２ O + 2e- ... (1) Electrode reaction occurring at air electrode 113A: 1 / 2O ２ +2e － →O ２－ → ... (2) Overall response: H ２ +1 / 2O ２ →H ２ O... (3)

[0049] In other words, at the fuel electrode 112A and the air electrode 113A, the main reactions proceed in parallel: an electrode reaction at the fuel electrode 112A and an electrode reaction at the air electrode 113A. When fuel gas G1 is supplied to the fuel electrode 112A and oxygen gas (for example, air) is supplied to the air electrode 113A, a direct current is generated between the fuel electrode 112A and the air electrode 113A. At this time, the electrode reaction at the fuel electrode 112A releases H from the fuel gas G1. ２ Oxygen ions (O) are supplied by moving from the air electrode 113A to the solid electrolyte 111A. ２－ ) reacts with water (H ２ O) and electrons (e － ) occurs. H ２ H produced by the reaction ２ O is discharged from fuel electrode 112A, H ２ e produced by the reaction － It moves from the fuel electrode 112A to the air electrode 113A. Due to the electrode reaction at the air electrode 113A, oxygen (O) from the air moves. ２ ) supplied from fuel electrode 112A － By reacting with O ２－ O occurs. ２ O produced by the reaction ２－ The H in the fuel gas G1 moves from the air electrode 113A through the solid electrolyte 111A to the fuel electrode 112A, and as described above, the electrode reaction at the fuel electrode 112A releases H ２ O ２－ H ２ O is generated.

[0050] The above describes the reaction when the solid electrolyte is an oxide ion conductor. However, when the solid electrolyte is a proton conductor, the following reaction occurs in the fuel cell cell 11A. At the fuel electrode 112A, the electrode reaction shown in equation (1-1) below occurs, and at the air electrode 113A, the electrode reaction shown in equation (2-1) below occurs. Overall, the reaction shown in equation (3) above occurs, producing water as a product. Electrode reaction occurring at fuel electrode 112A: H ２ →2H ＋ +2e － ... (1-1) Electrode reaction occurring at air electrode 113A: 1 / 2O ２ +2H ＋ +2e － →H ２ O... (2-1)

[0051] At this time, the electrode reaction at the fuel electrode 112A causes H in the fuel gas G1 ２ When oxidized, hydrogen ions (H) ＋ ) and electrons (e － ) occurs. H ２ H produced by the decomposition of ＋ H passes through the solid electrolyte 111A and moves to the air electrode 113A. ２ e produced by the decomposition of － It moves from the fuel electrode 112A to the air electrode 113A. Due to the electrode reaction at the air electrode 113A, oxygen (O) from the air moves. ２ H ) is supplied from the fuel electrode 112A through the solid electrolyte 111A. ＋ And e supplied from fuel electrode 112A － It reacts with water (H ２ O) occurs.

[0052] Furthermore, in the fuel electrode 112A, H ２ When water is produced from gas, some H ２ Sometimes the gas remains unreacted. ２ The gas, along with water, is discharged from the fuel cell cell 11A to the outside via the fuel electrode 112A.

[0053] In the first fuel cell 10A, when the fuel gas G1 passes through the fuel electrode 112A, H contained in the fuel gas G1 ２The gas turns into water, and fuel gas G2A containing water is discharged from the first fuel cell 10A.

[0054] Although Figure 1 shows only one fuel cell cell 11A, the first fuel cell 10A may have multiple fuel cell cells 11A. In this case, each fuel cell cell 11A is aligned in orientation such that, for example, the arrangement of the fuel electrode 112A and the air electrode 113A is the same, and they are stacked with a conductive plate in between adjacent fuel cell cells 11A. This connects each fuel cell cell 11A electrically in series. The conductive plate is made of a conductive material such as metal. Each fuel cell cell 11A may be connected in parallel, or a combination of series and parallel connections may be used.

[0055] The second fuel cell 10B will now be described. The second fuel cell 10B contains H2A, which is emitted from the fuel gas G2A of the first fuel cell 10A. ２ The gas is reacted to generate electricity. Since the second fuel cell 10B is the same as the first fuel cell 10A, details of the second fuel cell 10B are omitted.

[0056] In the second fuel cell 10B, when the fuel gas G2A passes through the fuel electrode 112A, H contained in the fuel gas G2A ２ The gas turns into water, and fuel gas G2B containing water is emitted from the second fuel cell 10B.

[0057] The second fuel cell 10B may be positioned in a location that is easily able to receive heat from the first fuel cell 10A. For example, as shown in Figure 3, multiple first fuel cells 10A (four in Figure 3) may be arranged around the outer periphery of the second fuel cell 10B. This allows the multiple first fuel cells 10A to function as heat-insulating material for the second fuel cell, making it easier for the temperature of the second fuel cell 10B to rise and making it easier to maintain high current density and output.

[0058] As shown in Figure 4, the fuel cell 10 may have an insulating layer 12 around it. The insulating layer 12 may have an insulating layer 12A that covers the first fuel cell 10A, an insulating layer 12B that covers the second fuel cell 10B, and an insulating layer 12C that covers insulating layers 12A and 12B. The insulating layer 12 may be composed of one or two of insulating layers 12A, 12B, and 12C.

[0059] By having an insulating layer 12 around the fuel cell 10, the heat generated in the first fuel cell 10A and the second fuel cell 10B is prevented from being released to the outside from the internal space of the insulating layer 12A, insulating layer 12B, or insulating layer 12C, thereby providing insulation. In addition, it is possible to prevent the first fuel cell 10A and the second fuel cell 10B from coming into contact with the outside air. As a result, the first fuel cell 10A and the second fuel cell 10B can each maintain their respective temperatures more easily. Therefore, the heat generated by the electrode reaction at the fuel electrode 112A and air electrode 113A in the first fuel cell 10A makes it easier to adjust the reaction temperature of the first fuel cell 10A to a temperature where the reforming reaction is more dominant than the hydrocarbon precipitation reaction. Similarly, the heat generated by the electrode reaction at the fuel electrode 112B and air electrode 113B in the second fuel cell 10B makes it easier to adjust the reaction temperature of the second fuel cell 10B to a temperature where the hydrocarbon precipitation reaction is more dominant than the reforming reaction.

[0060] The material used to form the thermal insulation layer 12 is not particularly limited, as long as it is a material commonly used as thermal insulation.

[0061] Furthermore, the insulation layers 12A, 12B, and 12C may each have a connecting pipe that communicates with the outside. Since the heat generated in the internal space of the insulation layers 12A, 12B, or 12C can be released to the outside through the connecting pipe, it becomes easier to adjust the temperature of the internal space of the insulation layers 12A, 12B, or 12C to any desired temperature and to maintain that adjusted temperature.

[0062] [Reforming Unit] The adjustment unit 20 removes MCH and TOL remaining in the fuel gas G1 through a reforming reaction, thereby reducing the content of MCH and TOL remaining in the fuel gas G1. If the first fuel cell 10A is operated normally at its rated speed, the MCH and TOL remaining in the fuel gas G1 may not be sufficiently removed in the first fuel cell 10A. In this case, when the fuel gas G2A discharged from the first fuel cell 10A is supplied to the second fuel cell 10B, the MCH and TOL remaining in the fuel gas G2A may precipitate in the second fuel cell 10B, potentially causing coking. By reforming the MCH and TOL remaining in the fuel gas G1 in the adjustment unit 20 according to the content of MCH and TOL remaining in the fuel gas G1, and reducing the content of MCH and TOL remaining in the fuel gas G1, the occurrence of coking in the second fuel cell 10B can be further suppressed.

[0063] The reforming reaction can be, for example, a steam reforming reaction using water. The water used in the reforming reaction may be supplied from an external source, or it may be water contained in at least one of the fuel gas G2A discharged from the first fuel cell 10A and the fuel gas G2B discharged from the second fuel cell 10B. The water discharged from the first fuel cell 10A and the second fuel cell 10B is supplied to the adjustment unit 20 through the circulation line L14. Since the fuel cell 10 discharges water, the adjustment unit 20 can improve the overall efficiency of the fuel cell system 1 by using the water discharged from the fuel cell 10.

[0064] The content of MCH and TOL remaining in the fuel gas G1 after modification in the adjustment unit 20 is preferably as low as possible, for example, preferably 500 ppm or less.

[0065] The adjustment unit 20 can be a commonly used separation device or reforming device. As a separation device, for example, devices using pressure swing adsorption (PSA), temperature swing adsorption (TSA), cryogenic separation (distillation), membrane separation, steam reforming, chemical adsorption, and physical adsorption methods can be used. As a reforming device, a general reformer can be used.

[0066] [Separation section] As shown in Figure 1, the separation section 30 has a separation section 30A provided in the fluid discharge line L12A and a separation section 30B provided in the fluid discharge line L12B.

[0067] The separation unit 30A separates water and other substances from the fuel gas G2A discharged from the first fuel cell 10A. In the separation unit 30A, water and the fuel gas G2A from which the water has been separated are separated.

[0068] The separation unit 30B separates water and other substances from the fuel gas G2B discharged from the second fuel cell 10B. In the separation unit 30B, water and the fuel gas G2B from which the water has been separated are separated.

[0069] The separation unit 30 may be, for example, a general gas-liquid separator, and the water and hydrocarbons (for example, MCH and TOL) in the fuel gases G2A and G2B may be separated using general processes such as distillation separation, extraction separation, membrane separation, and adsorption separation.

[0070] [Measurement Unit] The measurement unit 40 includes temperature measurement units 41A and 41B, flow rate measurement units 42A and 42B, and a concentration measurement unit 43. The signal indicating the detection result measured by the measurement unit 40 is input to the control device 50.

[0071] The temperature measuring unit 41A is installed in the fluid discharge line L12A and measures the temperature T1 of the fuel gas G2A discharged from the fuel electrode 112A of the first fuel cell 10A to obtain the reaction temperature of the first fuel cell. The temperature measuring unit 41B is installed in the fluid discharge line L12B and measures the temperature T2 of the fuel gas G2B discharged from the fuel electrode 112B of the second fuel cell 10B. The temperature measuring units 41A and 41B only need to be able to measure the temperature T1 of the fuel gas G1 or the temperature T2 of the fuel gas G2A, and for example, commonly used thermometers may be used as the temperature measuring units 41A and 41B. The temperature measuring units 41A and 41B transmit a signal indicating the measured temperature to the control device 50.

[0072] The flow rate measuring unit 42A is installed in the gas transport line L11 and measures the flow rate of fuel gas G1 supplied to the fuel cell 10. The flow rate measuring unit 42B is installed in the fluid discharge line L12A and measures the flow rate of fuel gas G2A discharged from the fuel electrode 112A of the first fuel cell 10A. The flow rate measuring units 42A and 42B only need to be able to measure the flow rate of fuel gas G1 or fuel gas G2A, and for example, commonly used flow meters may be used as the flow rate measuring units 42A and 42B. The flow rate measuring units 42A and 42B transmit a signal indicating the measured flow rate to the control device 50.

[0073] The concentration measuring unit 43 is installed in the gas transport line L11 and measures the concentration of hydrocarbons in the fuel gas G1 supplied to the fuel cell 10. The concentration measuring unit 43 only needs to be able to measure the concentration of hydrocarbons in the fuel gas G1, and may use, for example, a commonly used concentration sensor. The concentration measuring unit 43 transmits a signal indicating the measured concentration of hydrocarbons in the fuel gas G1 to the control device 50.

[0074] [Management device] The management device 50 is electrically connected to each component constituting the fuel cell system 1, such as the adjustment unit 20, the separation unit 30, and the measurement unit 40, in a controllable manner, and manages the fuel cell 10. The management device 50 has an input unit 51, a management unit 52, and an output unit 53.

[0075] The input unit 51 is electrically connected to the measurement unit 40 so as to be able to receive signals indicating the detection results of the measurement unit 40. The input unit 51 acquires signals indicating the temperature T1 of fuel gas G2A sent from the temperature measurement unit 41A and the temperature T2 of fuel gas G2B sent from the temperature measurement unit 41B. The input unit 51 also acquires signals indicating the flow rate of fuel gas G1 sent from the flow rate measurement unit 42A, the flow rate of fuel gas G2A sent from the flow rate measurement unit 42B, and the concentration of hydrocarbons in fuel gas G1 sent from the concentration measurement unit 43. Based on the measurement results of the measurement unit 40 received by the input unit 51, the control unit 52 manages the supply amount of fuel gas G1 supplied to the fuel cell 10 by the control valve V1, manages the operating temperature of the fuel cell 10, and manages the degree of heating of the fuel gas G1 supplied to the fuel cell 10.

[0076] The control unit 52 manages the operation of the first fuel cell 10A to ensure that the reforming reaction of hydrocarbons contained in the fuel gas G1 takes place in the first fuel cell 10A. As a result, when the fuel gas G1 passes through the fuel electrode 112A of the first fuel cell 10A, the MCH and TOL in the fuel gas G1 are reformed by the reforming reaction of MCH and TOL, and CO ２ , CO or CH ４ It can be modified to include the following. As a result, the first fuel cell 10A can reduce the amount of MCH and TOL contained in the fuel gas G1. Therefore, in the second fuel cell 10B, the amount of H contained in the fuel gas G2A emitted from the first fuel cell 10A ２ When the reaction is carried out, the operating temperature of the second fuel cell 10B can be set to a high temperature (for example, 700°C or higher) in which the MCH and TOL contained in the fuel gas G2A can be thermally decomposed, and the temperature can be set to a temperature in which the carbon deposition reaction of MCH and TOL occurs. Even if the operating temperature of the second fuel cell 10B is set to a high temperature in which the carbon deposition reaction of MCH and TOL occurs, it is possible to suppress the decomposition of MCH and TOL and the formation of coking on the fuel electrode 112B of the second fuel cell 10B.

[0077] In other words, the control unit 52 can manage the output of the second fuel cell 10B to increase without considering the carbon deposition reaction of MCH and TOL contained in the fuel gas G2A. Therefore, the second fuel cell 10B can be operated at high temperature, high efficiency, and high output without worrying about coking occurring in the second fuel cell 10B.

[0078] The control unit 52 preferably manages the reaction conditions of the first fuel cell 10A such that the reforming reaction is more dominant than the carbon deposition reactions of MCH and TOL in the first fuel cell 10A.

[0079] Furthermore, "superiority" means that the reforming reaction must take precedence over the carbon deposition reactions of MCH and TOL.

[0080] "Reaction conditions" include conditions relating to the reaction of the first fuel cell 10A and the second fuel cell 10B. "Reaction conditions" should be conditions that can primarily control the temperature of the fuel cell cell 11A in the first fuel cell 10A and the fuel cell cell 11B in the second fuel cell 10B, the flow rate of fuel gas G1 supplied to the first fuel cell 10A, or the gas flow rate of fuel gas G2A into the second fuel cell 10B. "Reaction conditions" include, for example, the amount of heat generated by the fuel cell cells 11A and 11B in the first fuel cell 10A and the second fuel cell 10B, the temperatures of fuel gas G1 and fuel gas G2A in the first fuel cell 10A and the second fuel cell 10B, and the current density of the current generated in the first fuel cell 10A and the second fuel cell 10B. "Reaction conditions" may be conditions that are directly or indirectly controlled.

[0081] In the first fuel cell 10A, the reforming reaction is more dominant than the carbon deposition reaction of MCH and TOL, so that MCH and TOL contained in the fuel gas G1 are preferentially removed in the first fuel cell 10A, thereby reducing the amount of MCH and TOL contained in the fuel gas G2A emitted from the first fuel cell 10A.

[0082] The control unit 52 preferably controls the reaction temperature of the first fuel cell 10A by controlling the current generated in the first fuel cell 10A as a reaction condition, thereby controlling the current density of the first fuel cell 10A, so that the reforming reaction is more dominant than the carbon deposition reactions of MCH and TOL. The current generated in the first fuel cell 10A can be controlled, for example, by controlling the load resistance for power extraction within the first fuel cell 10A. If the current density is low, the reaction temperature will decrease, and if the current density is high, the reaction temperature will increase. The control unit 52 can appropriately manage the operating temperature of the first fuel cell 10A by adjusting the current density of the first fuel cell 10A.

[0083] The control unit 52 preferably controls the first fuel cell 10A to substantially reform almost all of the MCH and TOL remaining in the fuel gas G1 supplied to the first fuel cell 10A. As a result, substantially almost all of the MCH and TOL contained in the fuel gas G1 is reformed and removed in the first fuel cell 10A, so that there is almost no MCH and TOL in the fuel gas G2A discharged from the first fuel cell 10A. Therefore, in the second fuel cell 10B, the H contained in the fuel gas G2A ２ When the reaction is initiated, even if the operating temperature of the second fuel cell 10B is set to a high temperature (for example, 700°C or higher) in which the MCH and TOL contained in the fuel gas G2A can be thermally decomposed, the decomposition of MCH and TOL and the formation of coking on the fuel electrode 112B of the second fuel cell 10B can be further suppressed. Therefore, the control unit 52 can manage to increase the output of the second fuel cell 10B without considering the carbon deposition reaction of MCH and TOL contained in the fuel gas G2A, so that the second fuel cell 10B can be operated at high temperature and high efficiency with high current density and high output without worrying about the formation of coking in the second fuel cell 10B.

[0084] The control unit 52 may also manage the first fuel cell 10A to substantially reform almost all of the MCH or TOL remaining in the fuel gas G1 supplied to the first fuel cell 10A.

[0085] The control unit 52 preferably manages the reaction conditions of the second fuel cell 10B so that the carbon deposition reaction is more dominant than the reforming reactions of MCH and TOL in the second fuel cell 10B. In the first fuel cell 10A, MCH and TOL contained in the fuel gas G1 are removed, so the amount of MCH and TOL contained in the fuel gas G2A discharged from the first fuel cell 10A is reduced. For this reason, in the second fuel cell 10B, the H contained in the fuel gas G2A is reduced. ２When the reaction is initiated, even if the operating temperature of the second fuel cell 10B is set to a high temperature (for example, 500°C or higher) in which the MCH and TOL contained in the fuel gas G2A can be thermally decomposed, it is possible to suppress the decomposition of MCH and TOL and the formation of coking on the fuel electrode 112B of the second fuel cell 10B. Therefore, the control unit 52 can manage to increase the output of the second fuel cell 10B without considering the carbon deposition reaction of MCH and TOL contained in the fuel gas G2A, and thus the second fuel cell 10B can be operated at high temperature and high efficiency with high current density and high output without worrying about the formation of coking in the second fuel cell 10B.

[0086] Preferably, the control unit 52 controls the adjustment unit 20 to adjust the amount of MCH and TOL contained in the fuel gas G1 supplied to the first fuel cell 10A to an amount that can be substantially completely reformed in the first fuel cell 10A, in accordance with the reaction conditions of the first fuel cell 10A. As a result, even when the first fuel cell 10A is operated at its rated capacity, substantially almost all of the MCH and TOL contained in the fuel gas G1 can be reformed and removed in the first fuel cell 10A, and there will be almost no MCH and TOL contained in the fuel gas G2A discharged from the first fuel cell 10A. Furthermore, even if the first fuel cell 10A alone cannot sufficiently remove the MCH and TOL contained in the fuel gas G1, by removing some of the MCH and TOL contained in the fuel gas G1 in the adjustment unit 20, the occurrence of coking in the second fuel cell 10B caused by MCH and TOL that could not be completely removed in the first fuel cell 10A can be reduced. For this reason, in the second fuel cell 10B, H contained in the fuel gas G2A ２When causing [the substance] to react, even if the operating temperature of the second fuel cell 10B is set to a high temperature at which MCH and TOL contained in the fuel gas G2A can be thermally decomposed (for example, 500° C. or higher), it is possible to further suppress the occurrence of coking on the fuel electrode 112B of the second fuel cell 10B caused by the decomposition of MCH and TOL. Therefore, the management unit 52 can manage the output of the second fuel cell 10B to be increased without considering the carbon deposition reaction of MCH and TOL contained in the fuel gas G2A, so that the second fuel cell 10B can be operated at high temperature, high efficiency, high current density and high output without worrying about the occurrence of coking in the second fuel cell 10B.

[0087] Preferably, the management unit 52 manages the reaction temperature of the first fuel cell 10A to be 500° C. or higher and lower than 700° C. When the reaction temperature of the first fuel cell 10A exceeds 700° C., carbon deposition of TOL is likely to occur. The management unit 52 can suppress the precipitation of TOL contained in the fuel gas G1 in the first fuel cell 10A by managing the reaction temperature of the first fuel cell 10A to be 500° C. or higher and lower than 700° C.

[0088] Preferably, the management unit 52 manages the reaction temperature of the second fuel cell 10B to be 700° C. or higher. Since MCH and TOL contained in the fuel gas G1 are removed in the first fuel cell 10A, the content of MCH and TOL in the fuel gas G2 discharged from the first fuel cell 10A is reduced. Therefore, in the second fuel cell 10B, H contained in the fuel gas G2 ２ When causing [the substance] to react, even if the operating temperature of the second fuel cell 10B is set to 700° C. or higher, it is possible to suppress the occurrence of coking on the fuel electrode 112B of the second fuel cell 10B caused by the decomposition of MCH and TOL. Therefore, the management unit 52 can manage the output of the second fuel cell 10B to be increased without considering the carbon deposition reaction of MCH and TOL contained in the fuel gas G2, so that the second fuel cell 10B can be operated at high temperature, high efficiency, high current density and high output without worrying about the occurrence of coking in the second fuel cell 10B.

[0089] Preferably, the control unit 52 manages the output of the first fuel cell 10A so that the reaction temperature of the first fuel cell 10A is between 500°C and less than 700°C, based on the results obtained by the temperature measurement unit 41A. The output of the first fuel cell 10A can be adjusted, for example, by the current, voltage, and current density flowing through the first fuel cell 10A and the second fuel cell 10B. The current, voltage, and current density flowing through the first fuel cell 10A and the second fuel cell 10B can be adjusted, for example, by controlling the amount of fuel supplied to the fuel cell 10 by the control valve V1. Based on the temperature T1 of the fuel gas G2A discharged from the first fuel cell 10A, measured by the temperature measurement unit 41A, the temperature of the fuel gas G1 in the first fuel cell 10A can be appropriately managed to be between 500°C and less than 700°C. Therefore, the control unit 52 can suppress coking caused by TOL contained in the fuel gas G1 in the first fuel cell 10A.

[0090] Preferably, the control unit 52 controls the flow rate of the fuel gas G1 supplied to the fuel cell 10 based on the measurement results of the flow rate measuring units 42A and 42B, so that the reaction temperature of the first fuel cell 10A is between 500°C and 700°C. The flow rate of the fuel gas G1 supplied to the fuel cell 10 can be controlled by the control valve V1. By controlling the amount of fuel supplied to the fuel cell 10 with the control valve V1, the current, voltage, and current density flowing through the first fuel cell 10A and the second fuel cell 10B can be adjusted, and the output of the first fuel cell 10A and the second fuel cell 10B can be controlled. By suppressing the flow rate of the fuel gas G1 supplied to the first fuel cell 10A, for example, the reaction temperature of the first fuel cell 10A can be set to between 500°C and 700°C. If the reaction temperature of the first fuel cell 10A is between 500°C and 700°C, coking caused by TOL contained in the fuel gas G1 in the first fuel cell 10A can be suppressed. Furthermore, by increasing the flow rate of fuel gas G1, more H ２ Gas can be supplied. H supplied to the second fuel cell 10B ２ By increasing the amount of gas, the output of the second fuel cell 10B can be increased, thereby increasing the amount of electricity generated by the second fuel cell 10B.

[0091] As shown in Figure 1, the output unit 53 outputs signals related to the management contents of the management unit 52 and controls each component constituting the fuel cell system 1, such as the fuel cell 10, the adjustment unit 20, and the separation unit 30.

[0092] As described above, the control device 50 includes a control unit 52, which manages the operation of the first fuel cell 10A so that the reforming reaction of MCH and TOL contained in the fuel gas G1 takes place. As a result, the first fuel cell 10A can remove MCH and TOL contained in the fuel gas G1, although the power density of the first fuel cell 10A decreases. When the fuel gas G2A discharged from the first fuel cell 10A is supplied to the second fuel cell 10B, and the second fuel cell 10B generates electricity by reacting the hydrogen contained in the fuel gas G2A discharged from the first fuel cell 10A, the control device 50 can raise the operating temperature of the second fuel cell 10B to a high temperature, which is the temperature at which the carbon deposition reaction of MCH and TOL occurs. Since the hydrocarbons contained in fuel gas G1 are almost completely removed from the fuel gas G2A discharged from the first fuel cell 10A, even if the operating temperature of the second fuel cell 10B is raised above the temperature at which carbon deposition reactions of MCH and TOL occur, it is possible to suppress the occurrence of coking caused by hydrocarbons contained in fuel gas G1 within the second fuel cell 10B, and to generate electricity with high efficiency within the second fuel cell 10B.

[0093] Therefore, the control device 50 can operate the first fuel cell 10A in such a way that it suppresses the occurrence of coking on the fuel electrode 112B in the second fuel cell 10B, thereby ensuring high power generation efficiency and output. Consequently, the control device 50 can generate electricity while suppressing the occurrence of coking and maintaining high operating efficiency of the fuel cell 10.

[0094] Furthermore, the control device 50 can improve the energy efficiency of the fuel cell 10 by controlling the operating temperatures of the first fuel cell 10A and the second fuel cell 10B as described above and generating electricity. The control device 50 controls the residual MCH and TOL that cause coking in the first fuel cell 10A, which is the first stage and has a lower operating temperature, and CO ２ , CO or CH ４The hydrogen is reformed into other types of hydrocarbons. The first fuel cell 10A is inefficient at low temperatures, but its hydrogen purity can be increased. The control device 50 operates the second fuel cell 10B, which is the second stage and has a higher operating temperature, at a higher temperature to react the hydrogen and generate electricity with high efficiency. Therefore, the control device 50 can improve the fuel utilization rate (Uf) of the fuel cell 10.

[0095] Uf is the ratio of the flow rate of fuel gas consumed in the space containing the fuel electrode of the fuel cell to the flow rate of fuel gas supplied to the space containing the fuel electrode of the fuel cell. It represents the proportion of fuel effectively used at the fuel electrode and can be calculated using the following formula (I). The Uf of fuel cell 10 is expressed as the sum of the Uf of the first fuel cell 10A and the Uf of the second fuel cell 10B. Uf [%] = (Flow rate of fuel gas consumed by power generation at the fuel electrode of the fuel cell / Flow rate of fuel gas supplied to the space containing the fuel electrode of the fuel cell) × 100 ... (I)

[0096] For example, as shown in Figure 5, if there is only one fuel cell, the fuel cell is heated to a high temperature to reach the limit value of Uf (e.g., around 80%). ２ Even when generating electricity using gas, the Uf of the fuel cell is 80% (see Figure 5(a)). On the other hand, in this embodiment, the first fuel cell 10A generates electricity using hydrogen, albeit at low efficiency (i.e., Uf > 0), and the second fuel cell 10B generates electricity at a high temperature to reach the limit value of Uf. ２ By generating electricity using gas, the overall Uf of the fuel cell 10 exceeds 80%. Therefore, the control device 50 can improve the overall Uf of the fuel cell 10, thereby improving the fuel energy conversion efficiency of the fuel cell 10.

[0097] Furthermore, if coking occurs on the fuel electrode 112A, the second fuel cell 10B may deteriorate, potentially shortening the lifespan of the fuel cell system 1. The control device 50 can operate the fuel cell 10 in a way that ensures a high power output while suppressing coking, thereby improving the power generation efficiency of the fuel cell 10 while suppressing the reduction in the product lifespan of the fuel cell system 1.

[0098] (Hardware Configuration of the Management Device) The management device 50 is implemented by, for example, an information processing device (computer). An example of the computer's hardware configuration will be described. Figure 6 is a block diagram showing an example of the computer's hardware configuration. As shown in Figure 6, the computer 100 can be physically configured as a computer system including a processor 101 which is an arithmetic processing unit, memory 102, an input device 103 which is an input device, an output device 104 which is an output device, a communication module 105, and an auxiliary storage device 106 such as a hard disk. These are interconnected by a bus 107. The input device 103, the output device 104, and the auxiliary storage device 106 may be provided externally.

[0099] The processor 101 controls the overall operation of the management device 50 and performs various information processing. The processor 101 can predict the intensity index related to the intensity of the mass spectrum of a compound by executing a management method or management program, for example, one described later, which is stored in the memory 102 or auxiliary storage device 106. For example, the processor 101 may be a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit). The processor 101 may have both a CPU and a GPU.

[0100] Memory 102 includes RAM (Random Access Memory) and ROM (Read Only Memory), which are the main memory devices, and stores management programs such as programs for reading the measurement results from the temperature measurement unit 41 and the concentration measurement unit 43, and programs for calculating the control amount of the first fuel cell 10A using these results.

[0101] The RAM may be used as the work area of ​​the processor 101 and may include non-volatile RAM for storing major control parameters and information.

[0102] ROM stores basic input / output programs and other similar information. Management programs may also be stored in ROM.

[0103] The input device 103 is an input device such as a keyboard, mouse, operation buttons, touch panel, or display screen, which receives information input by the user as an instruction signal and outputs that instruction signal to the processor 101.

[0104] The output device 104 includes display devices such as monitor displays, speakers, and printing devices such as printers. In the output device 104, information such as learning results and prediction results of oil film density are displayed on a display device such as a monitor display, and the displayed screen is updated in response to input operations via the input device 103 or the communication module 105.

[0105] The communication module 105 is a data transmission and reception device such as a network card, and functions as a communication interface that receives information from an external data acquisition server and outputs the analyzed information to other electronic devices.

[0106] The auxiliary storage device 106 is a storage device such as an SSD (Solid State Drive) or an HDD (Hard Disk Drive), and stores various data, files, etc., necessary for the operation of the management device 50.

[0107] Each function of the management device 50 is realized by reading predetermined computer software (including a management program) from the memory 102 or auxiliary storage device 106 and executing it with the processor 101, thereby reading and writing data to the memory 102 and auxiliary storage device 106, and operating the input device 103, output device 104, and communication module 105.

[0108] Therefore, as shown in Figure 1, each part of the management device 50 is realized through the cooperation of software and hardware, by having the processor 101 execute predetermined computer software (including a management program) that is pre-stored in a computer equipped with the management device 50.

[0109] A computer program implementing at least some of the functions of the management device 50 shown in Figure 1 may be installed on the storage of one or more computers. The processor 101 of one or more computers may perform the functions of the management device 50 shown in Figure 1 by reading the computer program installed on its own machine into main memory and executing it.

[0110] The management device 50 shown in Figure 1 may be implemented by one or more processors 101. Here, processor 101 may refer to one or more electronic circuits arranged on one chip, or one or more electronic circuits arranged on two or more chips or two or more devices. When multiple electronic circuits are used, each electronic circuit may communicate by wired or wireless means.

[0111] Furthermore, the functions of each part of the management device 50 shown in Figure 1 may be executed by a single computer, or they may be executed in a distributed manner by multiple computers. When the functions of each part of the management device 50 shown in Figure 1 are executed in a distributed manner by multiple computers, these multiple computers may send and receive data via a communication network including a LAN (Local Area Network), WAN (Wide Area Network), PAN (Personal Area Network), or the Internet.

[0112] The management program can be stored, for example, in the computer's memory 102 or auxiliary storage device 106. Alternatively, the management program may be stored on a computer connected to a communication line such as the Internet, and provided by allowing users to download part or all of the management program via the communication line. Furthermore, the management program may be configured to be provided or distributed via a communication line.

[0113] The management program may be recorded (including installed) into a computer from a state where it is stored in whole or in part on a portable storage medium such as an optical disc like a CD-ROM or DVD-ROM, or a semiconductor memory like flash memory.

[0114] [Circulation Line] The fuel cell system 1 has a circulation line L1 through which a circulating fluid passes to each component of the fuel cell system 1, and supplies the circulating fluid or gas to each component in the fuel cell system 1 via the circulation line L1. The circulation line L1 includes a gas conveyance line L11, a fluid discharge line L12, a circulation line L14, and a bypass line L15.

[0115] The gas conveyance line L11 is connected to a first fuel cell 10A, and supplies H supplied from the outside such as a storage unit not shown ２ gas and fuel gas G1 containing hydrocarbons to the first fuel cell 10A. The flow rate of the fuel gas G1 flowing through the gas conveyance line L11 can be controlled by a control valve V1 provided on the gas conveyance line L11.

[0116] The fluid discharge line L12 includes a fluid discharge line L12A and a fluid discharge line L12B. The fluid discharge line L12A connects the first fuel cell 10A and the second fuel cell 10B via a separation unit 30A, and conveys fuel gas G2A containing hydrogenated substances discharged from the first fuel cell 10A to the second fuel cell 10B. The fluid discharge line L12B conveys fuel gas G2B containing hydrogenated substances discharged from the second fuel cell 10B to the outside.

[0117] The circulation line L14 includes a circulation line L14A and a circulation line L14B. The circulation line L14A connects the separation unit 30A and an adjustment unit 20, and supplies water separated from the fuel gas G2A by the separation unit 30A to the adjustment unit 20. The circulation line L14B connects the separation unit 30B and the circulation line L14A, and supplies water separated from the fuel gas G2B by the separation unit 30B to the circulation line L14A. The flow rate of water extracted into the circulation lines L14A and L14B can be controlled by control valves V11 and V12 provided on the circulation lines L14A and L14B, respectively.

[0118] The bypass line L15 is provided to bypass a part of the gas conveyance line L11 such that the fuel gas passes through the adjustment unit 20 in the gas conveyance line L11. The flow rate of the fuel gas G1 flowing through the bypass line L15 can be controlled by control valves V21 and V22 provided on the bypass line L15.

[0119] The operation of fuel cell system 1 will be explained. In fuel cell system 1, H ２ Fuel gas G1, which contains gases and hydrocarbons, is supplied to the first fuel cell 10A through the gas transport line L11 and used as fuel for power generation.

[0120] At this time, the control unit 52 of the control device 50 controls the operation of the first fuel cell 10A so that the fuel gas G1 undergoes a hydrocarbon reforming reaction.

[0121] H ２ The fuel gas G2A, which contains gas, is supplied to the second fuel cell 10B after the water contained in the fuel gas G2A is separated in the separation unit 30A. At this time, the control unit 52 of the control device 50 manages the operation of the second fuel cell 10B so that the hydrogen in the fuel gas G2A reacts to generate electricity.

[0122] The fuel gas G2B discharged from the second fuel cell 10B to the fluid discharge line L12B is separated from the water contained in the fuel gas G2B in the separation unit 30B, and then supplied to, for example, a storage unit (not shown), where it is stored. ２ The gas may be reused in the fuel cell 10, supplied to an external power generation device, burned and used for heat supply, or transported to a hydrogen station.

[0123] Thus, the fuel cell system 1 comprises a fuel cell 10 and a control device 50. The control device 50 manages the operation of the fuel cell 10 and controls the operation of the first fuel cell 10A so that the hydrocarbon (MCH and TL) reforming reaction takes place in the first fuel cell 10A. As a result, the fuel cell system 1 can generate electricity while suppressing coking and maintaining the high operating efficiency of the fuel cell 10. Therefore, the fuel cell system 1 can generate electricity efficiently and operate stably.

[0124] In this embodiment, the fuel cell system 1 is managed by the control unit 52, which controls the control valve V1 and other operations based on the measurement results of the measurement unit 40. However, the actual control may be automated. Alternatively, the operation of the fuel cell system 1 may be controlled by an operator as needed. In this case, the control unit 52 manages the operation of the fuel cell system 1 by instructing the operator on the objects to be controlled and the amount of control to be controlled.

[0125] <Management Method> The management method according to this embodiment, which is performed in the management device 50, will now be described. The management method according to this embodiment can be performed using the management device 50 described above. Therefore, in each step, some of the contents already described for the management device 50 described above will be omitted. Here, the fuel cell system 1 is in operation and H is produced in the fuel cell 10. ２ The operation of the fuel cell 10 is controlled by the control unit 52 of the control device 50 so that it generates electricity using fuel gas G1 containing gas and hydrocarbons (MCH and TL).

[0126] Figure 7 is a flowchart illustrating the management method according to this embodiment. As shown in Figure 7, in the management method according to this embodiment, when the fuel cell system 1 is operating and generating power with the fuel cell 10, the input unit 51 acquires the temperature T1 of the fuel gas G2A measured by the temperature measurement unit 41A, the temperature T2 of the fuel gas G2B measured by the temperature measurement unit 41B, and the concentration C1 of hydrocarbons (MCH and TOL) in the fuel gas G1 measured by the concentration measurement unit 43 (measurement information acquisition step: step S10).

[0127] Next, the control unit 52 determines, based on the hydrocarbon concentration C1 in the fuel gas G1 acquired in the measurement information acquisition step S10, whether the hydrocarbon concentration C1 in the fuel gas G1 can be reformed by the first fuel cell 10A to almost all of the hydrocarbons in the fuel gas G1 (concentration determination step: step S20).

[0128] If the hydrocarbon concentration C1 in the fuel gas G1 is such that the first fuel cell 10A can reform almost all of the hydrocarbons in the fuel gas G1 (step S20: YES), the control unit 52 controls the operating temperature of the first fuel cell 10A so that the first fuel cell 10A is at a temperature at which the hydrocarbon reforming reaction in the fuel gas G1 is preferentially carried out (first control step: step S30).

[0129] In the first management step S30, as shown in Figure 8A, the management unit 52 determines whether the temperature T1 of the fuel gas G2A acquired in the measurement information acquisition step S10 is 500°C or more and less than 700°C (first temperature determination step: step S31).

[0130] If the temperature T1 of the fuel gas G2A is 500°C or higher but less than 700°C (Step S21: YES), the control unit 52 determines that the operating temperature of the first fuel cell 10A is 500°C or higher but less than 700°C. As shown in Figure 7, the control unit 52 controls the operating temperature of the second fuel cell 10B so that the second fuel cell 10B is at a temperature at which the precipitation reaction of hydrocarbons in the fuel gas G2A occurs preferentially (Second control step: Step S40).

[0131] In the second management step S40, as shown in Figure 8B, the management unit 52 determines whether the temperature T2 of the fuel gas G2B acquired in the measurement information acquisition step S10 is 700°C or higher (first temperature determination step: step S41).

[0132] If the temperature T1 of the fuel gas G2B is 700°C or higher (step S41: YES), the control unit 52 determines that the operating temperature of the second fuel cell 10B is 700°C or higher, which is above the temperature at which hydrocarbon precipitation reaction preferentially occurs, and terminates the operation management of the first fuel cell 10A and the second fuel cell 10B as shown in Figure 7.

[0133] On the other hand, in the concentration determination step S20, if the hydrocarbon concentration C1 in the fuel gas G1 is such that the first fuel cell 10A cannot reform almost all of the hydrocarbons in the fuel gas G1 (step S20: NO), the control unit 52 closes control valve V1 and opens control valves V21 and V22, and supplies the fuel gas G1 to the adjustment unit 20 to perform the hydrocarbon reforming reaction in the fuel gas G1 (adjustment step: step S50).

[0134] After the hydrocarbon reforming reaction in the fuel gas G1 has been carried out, the control unit 52 controls the operating temperature of the first fuel cell 10A so that the first fuel cell 10A carries out the hydrocarbon reforming reaction in the fuel gas G1 (first control step: step S30).

[0135] Furthermore, in Figure 8A, if the temperature T1 of the fuel gas G2A is not between 500°C and 700°C (step S31: NO), the control unit 52 determines that the operating temperature of the first fuel cell 10A is outside the range of 500°C and 700°C, and that this is not a temperature at which the hydrocarbon reforming reaction in the fuel gas G1 in the first fuel cell 10A will proceed preferentially. The control unit 52 manages the output of the first fuel cell 10A and other factors to control the operating temperature of the first fuel cell 10A so that the hydrocarbon reforming reaction in the fuel gas G1 in the first fuel cell 10A proceeds preferentially (first output control step: step S32).

[0136] After controlling the output of the first fuel cell 10A, the process proceeds to the measurement information acquisition step S10 shown in Figure 7.

[0137] Furthermore, in Figure 8B, if the temperature T2 of the fuel gas G2B is less than 700°C (step S41: NO), the control unit 52 determines that the operating temperature of the second fuel cell 10B is less than 700°C, and that this is not a temperature at which the hydrocarbon reforming reaction in the fuel gas G1 preferentially occurs in the first fuel cell 10A. The control unit 52 manages the output of the second fuel cell 10B and other parameters to control the operating temperature of the second fuel cell 10B so that it becomes a temperature at which the hydrocarbon precipitation reaction in the fuel gas G2A preferentially occurs in the second fuel cell 10B (second output management step: step S42).

[0138] After controlling the output of the second fuel cell 10B, the process proceeds to the measurement information acquisition step S10 shown in Figure 7.

[0139] The control method according to this embodiment includes a first control step S30, in which the operation of the first fuel cell 10A is managed so that the reforming reaction of MCH and TOL contained in the fuel gas G1 takes place in the first fuel cell 10A. As a result, the control method according to this embodiment can remove MCH and TOL contained in the fuel gas G1 in the first fuel cell 10A. Therefore, the fuel gas G2A discharged from the first fuel cell 10A contains almost no hydrocarbons. Thus, even if the operating temperature of the second fuel cell 10B is raised to an even higher temperature than the operating temperature of the first fuel cell 10A in the second control step S40, and controlled to a temperature at which the carbon deposition reaction of MCH and TOL occurs, the occurrence of coking caused by hydrocarbons in the second fuel cell 10B can be suppressed. Furthermore, by raising the operating temperature of the second fuel cell 10B to an even higher temperature, the control method according to this embodiment can generate electricity with high efficiency in the second fuel cell 10B.

[0140] The management method according to this embodiment suppresses the occurrence of coking on the fuel electrode 112B in the second fuel cell 10B, and allows the first fuel cell 10A to be operated in a way that ensures high power generation efficiency and power output. Therefore, power generation can be performed while suppressing the occurrence of coking and maintaining high operating efficiency of the fuel cell 10.

[0141] As described above, embodiments of the present invention have been explained, but these embodiments are presented as examples only, and the present invention is not limited by these embodiments. The above embodiments can be implemented in various other forms, and various combinations, omissions, substitutions, or modifications are possible without departing from the spirit of the invention. The above embodiments and their variations are included in the scope or spirit of the invention, as well as in the scope of the invention and its equivalents as described in the claims.

[0142] The embodiments of the present invention are, for example, specified by the following embodiments: [1] A control device for managing a power generation apparatus having a first fuel cell that generates electricity by reacting a portion of the hydrogen contained in a fuel containing hydrogen and hydrocarbons, and a second fuel cell that generates electricity by reacting the hydrogen discharged from the first fuel cell, the control device having a control unit that manages the operation of the first fuel cell so that the first fuel cell performs a reforming reaction of the hydrocarbons. [2] The control device according to [1], wherein the control unit manages the reaction conditions of the first fuel cell so that the reforming reaction is more dominant than the carbon deposition reaction of the hydrocarbons. [3] The control device according to [1] or [2], wherein the control unit manages the reaction conditions of the second fuel cell so that the carbon deposition reaction is more dominant than the reforming reaction of the hydrocarbons. [4] The control device according to any one of [1] to [3], wherein the control unit controls the reaction temperature of the first fuel cell by controlling the current density of the first fuel cell so that the reforming reaction is more dominant than the carbon deposition reaction of the hydrocarbons. [5] The control device according to any one of [1] to [4], wherein the fuel is obtained by a dehydrogenation reaction of an organic hydride. [6] The control device according to any one of [1] to [5], wherein the reforming reaction is a steam reforming reaction using water, and the water is water discharged by the reaction of at least one of the first fuel cell and the second fuel cell. [7] The control device according to any one of [1] to [6], wherein the fuel contains an organic hydride and a hydrogenated product produced by the dehydrogenation reaction of the organic hydride as the hydrocarbon, and the first fuel cell substantially reforms at least one of the organic hydride and hydrocarbon components remaining in the fuel. [8] The fuel contains, as the hydrocarbon, an organic hydride and a hydride produced by the dehydrogenation reaction of the organic hydride, the power generation device has an adjustment unit for adjusting the amount of at least one of the organic hydride and hydrocarbon components remaining in the fuel, and the control device controls the adjustment unit to adjust the amount of at least one of the organic hydride and hydrocarbon components to an amount that is substantially fully reformable in accordance with the reaction conditions of the first fuel cell, as described in [5].[9] The control device according to any one of [1] to [8], wherein the first fuel cell and the second fuel cell are solid oxide fuel cells.

[10] The control device according to any one of [1] to [9], wherein the hydrocarbon comprises at least one of a hydride and an organic hydride, the hydride being toluene and the organic hydride being methylcyclohexane.

[11] The control device according to

[10] , wherein the control device controls the reaction temperature of the first fuel cell to be 500°C or more and less than 700°C.

[12] The control device according to

[10] or

[11] , wherein the control device controls the reaction temperature of the second fuel cell to be 700°C or more.

[13] The control device according to any one of [1] to

[12] , wherein the control device has a temperature measuring unit that acquires the reaction temperature of the first fuel cell, and the control device controls the output of the first fuel cell based on the measurement result of the temperature measuring unit so that the reaction temperature of the first fuel cell is 500°C or more and less than 700°C.

[14] A control device according to any one of [1] to

[13] , having a flow rate measuring unit for measuring the flow rate of the fuel supplied to the fuel cell and the fuel discharged from the first fuel cell, wherein the control device controls the flow rate of the fuel supplied to the fuel cell based on the measurement results of the flow rate measuring unit so that the reaction temperature of the first fuel cell is 500°C or more and less than 700°C.

[15] A control device according to any one of [1] to

[14] , wherein the first fuel cell is arranged on the outer periphery of the second fuel cell.

[16] A control device according to any one of [1] to

[15] , wherein the fuel cell has an insulating layer around it.

[17] A control method for controlling a power generation device having a first fuel cell that generates electricity by reacting a portion of the hydrogen contained in a fuel containing hydrogen and hydrocarbons, and a second fuel cell that generates electricity by reacting the hydrogen discharged from the first fuel cell, the control method comprising a control step of controlling the operation of the first fuel cell so that the hydrocarbon reforming reaction is carried out in the first fuel cell.

[18] A fuel cell system comprising: a power generation device having a first fuel cell that generates electricity by reacting a portion of the hydrogen contained in a fuel containing hydrogen and hydrocarbons; and a second fuel cell that generates electricity by reacting the hydrogen discharged from the first fuel cell; and a control device for managing the operation of the power generation device, wherein the control device manages the operation of the first fuel cell so that the hydrocarbon reforming reaction is carried out in the first fuel cell.

[0143] This application claims priority based on Japanese Patent Application No. 2025-55536, filed with the Japan Patent Office on 28 March 2025, and incorporates all the contents of the said application.

[0144] 1 Fuel cell system 10 Fuel cell 10A First fuel cell 10B Second fuel cell 11A, 11B Fuel cell cell 12 Insulation layer 20 Adjustment unit 30 Separation unit 40 Measurement unit 41A, 41B Temperature measurement unit 42A, 42B Flow rate measurement unit 43 Concentration measurement unit 50 Control device 51 Input unit 52 Control unit 53 Output unit 111A, 111B Solid electrolyte 112A, 112B Fuel electrode 113A, 113B Air electrode G1, G2A, G2B Fuel gas

Claims

1. A control device for managing a power generation apparatus having a first fuel cell that generates electricity by reacting a portion of the hydrogen contained in a fuel containing hydrogen and hydrocarbons, and a second fuel cell that generates electricity by reacting the hydrogen discharged from the first fuel cell, the control device having a control unit that manages the operation of the first fuel cell so that the hydrocarbon reforming reaction is carried out in the first fuel cell.

2. The control unit controls the reaction conditions of the first fuel cell such that the reforming reaction is more advantageous than the carbon deposition reaction of the hydrocarbon, as described in claim 1.

3. The control unit controls the reaction conditions of the second fuel cell such that the carbon deposition reaction is more favorable than the hydrocarbon reforming reaction, as described in claim 1 or 2.

4. The control unit controls the current density of the first fuel cell to control the reaction temperature of the first fuel cell so that the reforming reaction is more favorable to the carbon deposition reaction of the hydrocarbon, as described in claim 1 or 2.

5. The control device according to claim 1 or 2, wherein the fuel is obtained by a dehydrogenation reaction of an organic hydride.

6. The control device according to claim 1 or 2, wherein the reforming reaction is a steam reforming reaction using water, and the water is water discharged from the reaction of at least one of the first fuel cell and the second fuel cell.

7. The control device according to claim 1 or 2, wherein the fuel contains, as the hydrocarbon, an organic hydride and a hydride produced by the dehydrogenation reaction of the organic hydride, and the first fuel cell substantially reforms at least one of the organic hydride and hydrocarbon components remaining in the fuel.

8. The control device according to claim 5, wherein the fuel contains, as the hydrocarbon, an organic hydride and a hydride produced by the dehydrogenation reaction of the organic hydride, the power generation device has an adjustment unit for adjusting the amount of at least one of the organic hydride and hydrocarbon components remaining in the fuel, and the control device controls the adjustment unit to adjust the amount of at least one of the organic hydride and hydrocarbon components to an amount that is substantially fully reformable in accordance with the reaction conditions of the first fuel cell.

9. The control device according to claim 1 or 2, wherein the first fuel cell and the second fuel cell are solid oxide fuel cells.

10. The control apparatus according to claim 1 or 2, wherein the hydrocarbon comprises at least one of a hydride and an organic hydride, the hydride being toluene and the organic hydride being methylcyclohexane.

11. The control device according to claim 10, wherein the control device controls the reaction temperature of the first fuel cell to 500°C or more and less than 700°C.

12. The control device according to claim 10, wherein the control device controls the reaction temperature of the second fuel cell to 700°C or higher.

13. The control device according to claim 10, further comprising a temperature measuring unit for acquiring the reaction temperature of the first fuel cell, wherein the control device manages the output of the first fuel cell based on the measurement results of the temperature measuring unit so that the reaction temperature of the first fuel cell is 500°C or more and less than 700°C.

14. A management method for managing a power generation apparatus having a first fuel cell that generates electricity by reacting a portion of the hydrogen contained in a fuel containing hydrogen and hydrocarbons, and a second fuel cell that generates electricity by reacting the hydrogen discharged from the first fuel cell, the management method comprising a management step of managing the operation of the first fuel cell so that the hydrocarbon reforming reaction is carried out in the first fuel cell.

15. A fuel cell system comprising: a power generation device having a first fuel cell that generates electricity by reacting a portion of the hydrogen contained in a fuel containing hydrogen and hydrocarbons; and a second fuel cell that generates electricity by reacting the hydrogen discharged from the first fuel cell; and a control device that manages the operation of the power generation device, wherein the control device manages the operation of the first fuel cell so that the hydrocarbon reforming reaction is carried out in the first fuel cell.

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