JP2014110226A - Fuel cell system and fuel cell operational method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the time required for transitioning of a fuel cell from activation to rating operation.SOLUTION: A fuel cell system 1 includes: a fuel cell 201 having an air electrode and a fuel electrode; a fuel supply device 5 for supplying fuel gas to the fuel electrode; a water vapor supply device 6 for supplying water vapor to the fuel electrode; and a controller 10. When the temperature of a power generation chamber where the fuel electrode is disposed is 400°C or more before the fuel cell 201 initiates a power generation, the controller 10 controls the fuel supply device 5 and the water vapor supply device 6 so that a gaseous mixture of the water vapor and the fuel gas is supplied to the fuel electrode. Such a fuel cell system 1 can place the fuel electrode in a reduction atmosphere due to the hydrogen generated by the fuel electrode from the water vapor and the fuel gas, prior to the fuel cell 201 initiating the power generation, thereby shortening the time required for the transitioning of the fuel cell 201 from initiating the power generation to a rated operation.

Description

  The present invention relates to a fuel cell system and a fuel cell operation method, and more particularly to a fuel cell system and a fuel cell operation method for generating electric power by chemically reacting fuel gas and oxygen.

  2. Description of the Related Art Fuel cells that generate electricity by chemically reacting fuel gas and oxygen are known. Among these, solid oxide fuel cells (hereinafter referred to as “SOFC”) use ceramics such as zirconia ceramics as an electrolyte, such as city gas, natural gas, petroleum, methanol, and coal gasification gas. Is a fuel cell operated using as a fuel. This SOFC has a high operating temperature of about 700 to 1000 ° C. in order to increase the ionic conductivity, and is known as a high-efficiency high-temperature fuel cell that is versatile. A fuel cell system equipped with such a fuel cell maintains the integrity of the fuel electrode when the fuel cell fuel is reformed from a hydrocarbon gas or the like to hydrogen or carbon monoxide and used for the reaction of the fuel electrode. While performing the reforming reaction, an appropriate amount of water vapor is supplied to the fuel cell so that the fuel cell appropriately generates power.

  Japanese Patent No. 3917838 discloses that the fuel and water vapor are introduced into the first fuel cell of the series connection module, thereby improving the efficiency of the entire system, improving the fuel utilization rate, and improving the efficiency of water vapor supply. A fuel cell system capable of achieving the above has been disclosed.

  Japanese Patent Laid-Open No. 2006-294508 discloses that a mixture of reformed gas and water vapor is generated by using the heat capacity of a fuel cell while continuing to supply a small amount of water and fuel gas even after power generation is stopped. A fuel cell power generator is disclosed that reduces the stack temperature while maintaining the fuel electrode layer side in the reduced state by supplying the fuel electrode to the fuel electrode.

Japanese Patent No. 3917838 JP 2006-294508 A

  Such a fuel cell system uses the reaction heat generated during power generation up to a predetermined temperature during rated operation after the temperature of the fuel cell is raised to a temperature at which power can be generated before shifting to a rated operation for generating predetermined power. However, when the temperature is raised, it is necessary to provide a period for gradually increasing the current flowing from the fuel cell to the power load. In such a fuel cell system, it is desired to shorten the time from when the fuel cell starts power generation until it shifts to rated operation.

  An object of the present invention is to provide a fuel cell system and a fuel cell operation method that shorten the time from when a fuel cell starts power generation until it shifts to a rated operation for generating predetermined power.

  A fuel cell system according to the present invention includes a fuel cell having an air electrode and a fuel electrode, a fuel supply device that supplies fuel gas to the fuel electrode, a water vapor supply device that supplies water vapor to the fuel electrode, and a control device. It has. When the temperature of the power generation chamber in which the fuel electrode is disposed is equal to or higher than a predetermined temperature before the fuel cell generates power, the control device generates a mixed gas in which the water vapor and the fuel gas are mixed. The fuel supply device and the water vapor supply device are controlled so as to be supplied to the electrodes. The predetermined temperature is 400 degrees or more.

  In such a fuel cell system, when the temperature of the power generation chamber is approximately 400 ° C. or higher, the mixed gas is supplied to the fuel electrode, thereby reforming hydrogen in earnest from the water vapor and the fuel gas. The reaction can begin at the fuel electrode, and the fuel electrode can be placed in a reducing atmosphere by the hydrogen before the fuel cell generates electricity. The temperature at which the reforming reaction can be used depends on the amount of hydrogen required and the activity capacity of the fuel electrode as a reforming catalyst, but the reforming reaction begins to occur when the temperature of the power generation chamber is generally higher than 350 ° C. Therefore, the temperature of the power generation chamber is preferably 350 ° C. or higher, and more preferably 400 ° C. or higher to obtain a reliable reforming reaction. In such a fuel cell system, since the fuel electrode is arranged in a reducing atmosphere before the fuel cell starts power generation, the fuel electrode atmosphere of the fuel cell from the temperature rising stage before the fuel cell starts power generation. The temperature can be raised using the fuel gas used for power generation while maintaining the reducing atmosphere, and after the temperature has risen to the predetermined temperature, the time until the fuel cell starts power generation and shifts to rated operation can be increased. It can be shortened.

  The control device further includes the fuel supply device and the fuel supply device such that the S / C ratio obtained by dividing the amount of water vapor containing the water vapor by the mixed gas by the amount of carbon containing the carbon in the mixed gas is 5 or more. Control the steam supply device.

  Such a fuel cell system can prevent carbon from being deposited on the fuel electrode, and can prevent current from leaking at the fuel electrode or the insulating portion when the fuel cell generates power.

  The fuel cell system according to the present invention further includes a thermometer for measuring the temperature of the power generation chamber in which the fuel electrode is disposed. At this time, the control device controls the fuel supply device and the water vapor supply device so that the mixed gas is supplied to the fuel electrode at a timing determined based on the temperature.

  The reforming reaction is promoted as the temperature of the fuel electrode increases. For this reason, such a fuel cell system allows the reforming reaction to proceed more appropriately by supplying the mixed gas to the fuel electrode after the temperature of the power generation chamber exceeds the predetermined temperature. The fuel electrode can be arranged in the reducing atmosphere with higher efficiency.

  The control device further has an S / C ratio of 5 or less obtained by dividing the amount of water vapor in which the mixed gas contains water vapor by the amount of carbon in which the mixed gas contains carbon when the fuel cell is generating power. Then, the fuel supply device and the water vapor supply device are controlled.

  Such a fuel cell system can prevent carbon from being deposited inside the cell stack, and can prevent current from leaking at the fuel electrode when the fuel cell generates power.

  The fuel cell system according to the present invention further includes a power load measuring device that measures the current flowing from the fuel cell to the power load that consumes the power generated by the fuel cell. At this time, when the fuel cell is generating electric power, the controller supplies the supply amount of the water vapor to the fuel electrode per unit time equal to the supply amount calculated based on the current. Thus, the water vapor supply device is further controlled.

  In such a fuel cell system, when the fuel cell is generating electric power, hydrogen is generated by a reforming reaction with fuel gas and water at the fuel electrode, and the fuel electrode is placed in a reducing atmosphere. Such a fuel cell system appropriately controls the amount of hydrogen in the atmosphere in which the fuel electrode is disposed by reducing the amount of water vapor supplied to the fuel electrode when the fuel cell is generating power. Can do.

  The fuel cell system according to the present invention further includes a reducing gas supply device that supplies the reducing gas to the fuel electrode. At this time, the control device further controls the reducing gas supply device so that the reducing gas is supplied to the fuel electrode before the mixed gas is supplied to the fuel electrode. When the mixed gas is supplied, the reducing gas supply device is controlled so that the reducing gas is not supplied to the fuel electrode.

  Such a fuel cell system can place the fuel electrode in a reducing atmosphere before the mixed gas is supplied to the fuel electrode.

  The fuel cell system according to the present invention further includes an inert gas supply device that supplies an inert gas to the fuel electrode. At this time, the control device is arranged so that the inert gas is supplied to the fuel electrode when the mixed gas is supplied to the fuel electrode, and the mixed gas is supplied to the fuel electrode. So that the supply amount of the inert gas supplied to the fuel electrode is smaller than the supply amount of the inert gas supplied to the fuel electrode before the mixed gas is supplied to the fuel electrode. In addition, the inert gas supply device is controlled.

  In such a fuel cell system, when the fuel cell generates electric power, the concentration of the fuel gas is prevented from being reduced by the inert gas, and electric power can be generated more appropriately.

  The control device supplies the reducing gas so that the reducing gas is not supplied to the fuel electrode when the fuel cell is generating power and the current flowing through the power load reaches a predetermined current. The apparatus is controlled, and the inert gas supply device is controlled so that the inert gas is not supplied to the fuel electrode.

  The fuel cell operating method according to the present invention is executed using a fuel cell system. The fuel cell system includes a fuel cell having an air electrode and a fuel electrode to which oxygen is supplied, a fuel supply device that supplies fuel gas to the fuel electrode, and a water vapor supply device that supplies water vapor to the fuel electrode. I have. In the fuel cell operation method according to the present invention, before the fuel cell generates power, when the fuel electrode is at 400 ° C. or higher, a mixed gas in which the water vapor and the fuel gas are mixed is supplied to the fuel electrode. Thus, the fuel supply device and the water vapor supply device are controlled, and the fuel cell generates power after the mixed gas is supplied to the fuel electrode.

  According to such a fuel cell operation method, the fuel cell system generates hydrogen from the water vapor and the fuel gas by supplying the mixed gas to the fuel electrode when the fuel electrode is at 400 ° C. or higher. Before the reforming reaction takes place at the fuel electrode and the fuel cell generates electricity, the fuel electrode can be placed in a reducing atmosphere by the hydrogen. According to such a fuel cell operation method, the fuel cell system has a temperature rising stage before the fuel cell starts power generation by arranging the fuel electrode in a reducing atmosphere before the fuel cell starts power generation. While maintaining the atmosphere of the fuel electrode of the fuel cell in a reducing atmosphere, the temperature can be raised using the fuel gas used for power generation. It is possible to shorten the time required to shift to operation.

  The fuel cell system and the fuel cell operation method according to the present invention are arranged from the time when the fuel cell starts power generation to the time when the fuel cell shifts to rated operation by arranging the fuel electrode in a reducing atmosphere before the fuel cell starts power generation. It is possible to shorten the time and suppress the deterioration of the cell due to the oxidation of the fuel electrode before starting the power generation.

It is a block diagram which shows the one aspect | mode of the fuel cell system by this invention. 1 illustrates one aspect of a SOFC module. 1 shows one embodiment of a cross section of a SOFC cartridge. 1 illustrates one aspect of a cell stack. It is a block diagram which shows a control apparatus.

  An embodiment of a fuel cell system will be described below with reference to the drawings. The fuel cell system 1 is applied to a combined power generation system 2 as shown in FIG. The combined power generation system 2 includes a fuel cell system 1 and a micro gas turbine 3. The fuel cell system 1 includes a fuel supply device 5, a water vapor supply device 6, a reducing gas supply device 7, an inert gas supply device 8, and a control device 10, and further includes a fuel supply system 11 and an oxidizing gas supply system 12. A fuel gas discharge system 14, an oxidizing gas discharge system 15, a recirculation line 16, and an SOFC (Solid Oxide Fuel Cell) module 201.

The fuel supply device 5 supplies the city gas to the fuel supply system 11 under the control of the control device 10. That is, the fuel supply device 5 includes a flow rate adjustment valve 21. The flow regulating valve 21 is installed in the middle of the flow path connecting the city gas supply source and the fuel supply system 11 and is controlled by the control device 10 so that the city gas is supplied from the city gas supply source to the fuel supply system 11. Varies the flow rate supplied per unit time. Note that as the fuel, hydrogen (H ₂ ), hydrocarbon gas such as carbon monoxide (CO), methane (CH ₄ ), or the like, or gas produced by a carbonaceous raw material gasification facility such as coal may be used.

  The water vapor supply device 6 supplies water vapor to the fuel supply system 11 by being controlled by the control device 10. That is, the water vapor supply device 6 includes a boiler 22, a flow rate adjustment valve 23, and an on-off valve 24. The boiler 22 generates water vapor by heating water supplied from a city water supply source. The flow rate adjusting valve 23 is controlled by the control device 10 to vary the flow rate at which the water vapor generated by the boiler 22 is supplied to the fuel supply system 11 per unit time. The on-off valve 24 opens and closes a flow path connecting the flow rate adjusting valve 23 and the fuel supply system 11 by being controlled by the control device 10.

  The reducing gas supply device 7 is controlled by the control device 10 so that the supply amount of hydrogen supplied from the reducing gas supply device 7 to the fuel supply system 11 per unit time becomes equal to a predetermined supply amount. In addition, hydrogen is supplied to the fuel supply system 11.

  The inert gas supply device 8 is controlled by the control device 10 so that the supply amount of nitrogen supplied from the inert gas supply device 8 to the fuel supply system 11 per unit time becomes equal to a predetermined supply amount. In addition, nitrogen is supplied to the fuel supply system 11. Note that the nitrogen can be replaced with another inert gas. Argon is illustrated as the inert gas.

  The fuel supply system 11 forms a flow path connected to the SOFC module 201. The fuel supply system 11 includes city gas supplied from the fuel supply device 5, water vapor supplied from the water vapor supply device 6, hydrogen supplied from the reducing gas supply device 7, and nitrogen supplied from the inert gas supply device 8. And the exhaust fuel gas supplied from the recirculation line are mixed, and the mixed gas is supplied to the SOFC module 201.

  The oxidizing gas supply system 12 forms a flow path connected to the SOFC module 201. The oxidizing gas supply system 12 supplies an oxidizing gas compressed by the micro gas turbine 3 to the SOFC module 201.

  The SOFC module 201 generates power by chemically reacting the mixed gas supplied from the fuel supply system 11 and the oxidizing gas supplied from the oxidizing gas supply system 12, and exhausts the exhaust oxidizing gas and the exhaust fuel gas. To do.

  The fuel gas discharge system 14 forms a flow path connected to the SOFC module 201. The fuel gas discharge system 14 supplies part of the exhaust fuel gas exhausted from the SOFC module 201 to the recirculation line 16 and supplies the remainder of the exhaust fuel gas to the micro gas turbine 3.

  The oxidizing gas discharge system 15 forms a flow path connected to the SOFC module 201. The oxidizing gas discharge system 15 supplies the oxidizing gas exhausted from the SOFC module 201 to the micro gas turbine 3.

  The recirculation line 16 forms a flow path that connects the fuel gas discharge system 14 and the fuel supply system 11. The recirculation line 16 supplies a part of the exhaust fuel gas supplied to the fuel gas discharge system 14 to the fuel supply system 11.

  The micro gas turbine 3 generates power using the city gas supplied from the city gas supply source, the exhaust fuel gas supplied from the fuel gas discharge system 14, and the exhaust oxidant gas supplied from the oxidant gas discharge system 15. Then, an oxidizing gas is supplied. That is, the micro gas turbine 3 includes a combustor 41, a gas turbine 42, a compressor 43, a generator 44, and a heat exchanger 45. The combustor 41 uses the exhaust oxidant gas supplied from the oxidant gas exhaust system 15 or the compressed fuel supplied from the compressor 43 to use the exhaust fuel gas supplied from the fuel gas exhaust system 14. Or by burning city gas supplied from a city gas supply source, high-temperature and high-pressure combustion exhaust gas is generated. The gas turbine 42 generates rotational power using the combustion exhaust gas generated by the combustor 41 and exhausts the exhaust gas. The compressor 43 supplies compressed air by compressing air using the rotational power generated by the gas turbine 42. The generator 44 may perform power generation when there is a surplus in the rotational power generated by the gas turbine 42. The heat exchanger 45 supplies the oxidizing gas by heating the compressed air supplied by the compressor 43 using the heat of the exhaust gas exhausted by the gas turbine 42. The flow rate of the oxidizing gas matches the flow rate of the compressed air supplied by the micro gas turbine 3.

  In the following, for convenience of explanation, the positional relationship of each component is specified using the expressions “upper” and “lower” on the basis of the paper surface, but this is not necessarily limited to the vertical direction. For example, the upward direction on the paper surface may correspond to the downward direction in the vertical direction. Moreover, you may respond | correspond to the horizontal direction where the up-down direction in a paper surface goes orthogonally to a perpendicular direction. In the following description, a cylindrical shape is described as an example of a cell stack of a solid oxide fuel cell (SOFC). However, the cell stack is not necessarily limited to this, and may be a flat cell stack, for example.

  As illustrated in FIG. 2, the SOFC module 201 includes, for example, a plurality of SOFC cartridges 203 and a pressure vessel 205 that stores the plurality of SOFC cartridges 203. The SOFC module 201 has a fuel gas supply pipe 207 and a plurality of fuel gas supply branch pipes 207a. The SOFC module 201 includes a fuel gas discharge pipe 209 and a plurality of fuel gas discharge branch pipes 209a. The SOFC module 201 includes an oxidizing gas supply pipe (not shown) and an oxidizing gas supply branch pipe (not shown). The SOFC module 201 includes an oxidizing gas discharge pipe (not shown) and a plurality of oxidizing gas discharge branch pipes (not shown).

  The fuel gas supply pipe 207 is provided outside the pressure vessel 205, and is connected to a fuel supply system 11 that supplies a predetermined gas composition and a predetermined flow rate of fuel gas corresponding to the amount of power generated by the SOFC module 201. It is connected to the fuel gas supply branch pipe 207a. The fuel gas supply pipe 207 branches and guides a predetermined flow rate of fuel gas supplied from the fuel supply system 11 to a plurality of fuel gas supply branch pipes 207a. The fuel gas supply branch pipe 207 a is connected to the fuel gas supply pipe 207 and is connected to a plurality of SOFC cartridges 203. The fuel gas supply branch pipe 207a guides the fuel gas supplied from the fuel gas supply pipe 207 to the plurality of SOFC cartridges 203 at a substantially equal flow rate, and makes the power generation performance of the plurality of SOFC cartridges 203 substantially uniform. .

  The fuel gas discharge branch pipe 209 a is connected to the plurality of SOFC cartridges 203 and also connected to the fuel gas discharge pipe 209. The fuel gas discharge branch pipe 209 a guides the exhaust fuel gas discharged from the SOFC cartridge 203 to the fuel gas discharge pipe 209. The fuel gas discharge pipe 209 is connected to a plurality of fuel gas discharge branch pipes 209 a and a part thereof is disposed outside the pressure vessel 205. The fuel gas discharge pipe 209 guides the exhaust fuel gas derived from the fuel gas discharge branch pipe 209a at a substantially equal flow rate to the outside of the pressure vessel 205 (fuel gas discharge system 14).

  Since the pressure vessel 205 is operated at an internal pressure of 0.1 MPa to about 1 MPa and an internal temperature of the atmospheric temperature to about 550 ° C., the pressure vessel 205 has a resistance to corrosion and resistance to oxidizing agents such as oxygen contained in the oxidizing gas. The possessed material is used. For example, a stainless steel material such as SUS304 is suitable.

  Here, in the present embodiment, a mode has been described in which a plurality of SOFC cartridges 203 are assembled and stored in the pressure vessel 205. However, the present invention is not limited to this. It can also be set as the aspect accommodated in the container 205. FIG.

  As shown in FIG. 3, the SOFC cartridge 203 includes a plurality of cell stacks 101, a power generation chamber 215, a fuel gas supply chamber 217, a fuel gas discharge chamber 219, an oxidizing gas supply chamber 221, and an oxidizing gas discharge chamber. 223. The SOFC cartridge 203 includes an upper tube plate 225a, a lower tube plate 225b, an upper heat insulator 227a, and a lower heat insulator 227b. In the present embodiment, the SOFC cartridge 203 includes a fuel gas supply chamber 217, a fuel gas discharge chamber 219, an oxidizing gas supply chamber 221, and an oxidizing gas discharge chamber 223 as shown in FIG. The fuel gas and the oxidizing gas have a structure that flows between the inside and the outside of the cell stack 101, but this is not always necessary, for example, the inside and the outside of the cell stack flow in parallel. Alternatively, the oxidizing gas may flow in a direction orthogonal to the longitudinal direction of the cell stack.

  The power generation chamber 215 is an area formed between the upper heat insulator 227a and the lower heat insulator 227b. The power generation chamber 215 is an area in which the fuel cell 105 of the cell stack 101 is disposed, and electricity is generated by electrochemically reacting the fuel gas and the oxidizing gas. Further, the temperature in the vicinity of the central portion of the power generation chamber 215 in the longitudinal direction of the cell stack 101 is a high temperature atmosphere of about 700 ° C. to 1100 ° C. during the steady operation of the SOFC module 201.

  The fuel gas supply chamber 217 is an area surrounded by the upper casing 229a and the upper tube plate 225a of the SOFC cartridge 203. The fuel gas supply chamber 217 communicates with the fuel gas supply branch pipe 207a through a fuel gas supply hole 231a provided in the upper casing 229a. In the fuel gas supply chamber 217, one end of the cell stack 101 is disposed with the inside of the base tube 103 of the cell stack 101 open to the fuel gas discharge chamber 219. The fuel gas supply chamber 217 guides the fuel gas supplied from the fuel gas supply branch pipe 207a through the fuel gas supply hole 231a into the base tube 103 of the plurality of cell stacks 101 at a substantially uniform flow rate. The power generation performance of the cell stack 101 is made substantially uniform.

  The fuel gas discharge chamber 219 is an area surrounded by the lower casing 229b and the lower tube plate 225b of the SOFC cartridge 203. The fuel gas discharge chamber 219 communicates with the fuel gas discharge branch pipe 209a through a fuel gas discharge hole 231b provided in the lower casing 229b. In the fuel gas discharge chamber 219, the other end of the cell stack 101 is disposed with the inside of the base tube 103 of the cell stack 101 open to the fuel gas discharge chamber 219. The fuel gas discharge chamber 219 collects exhaust fuel gas that passes through the inside of the base tube 103 of the plurality of cell stacks 101 and is supplied to the fuel gas discharge chamber 219, and passes through the fuel gas discharge hole 231b. It leads to the discharge branch pipe 209a.

  The oxidizing gas supply pipe is supplied with an oxidizing gas from the oxidizing gas supply system 12 and supplies an oxidizing gas having a predetermined gas composition and a predetermined flow rate to the oxidizing gas supply branch pipe corresponding to the power generation amount of the SOFC module 201. And then supply to a plurality of SOFC cartridges 203. The oxidizing gas supply chamber 221 is a region surrounded by the lower casing 229b, the lower tube sheet 225b, and the lower heat insulator 227b of the SOFC cartridge 203. The oxidizing gas supply chamber 221 communicates with an oxidizing gas supply branch pipe (not shown) through an oxidizing gas supply hole 233a provided in the lower casing 229b. The oxidizing gas supply chamber 221 generates a predetermined flow rate of oxidizing gas supplied from an oxidizing gas supply branch pipe (not shown) through an oxidizing gas supply hole 233a through an oxidizing gas supply gap 235a described later. It leads to the chamber 215.

  The oxidizing gas discharge chamber 223 is a region surrounded by the upper casing 229a, the upper tube plate 225a, and the upper heat insulator 227a of the SOFC cartridge 203. The oxidizing gas discharge chamber 223 communicates with an oxidizing gas discharge branch pipe (not shown) through an oxidizing gas discharge hole 233b provided in the upper casing 229a. The oxidizing gas discharge chamber 223 allows the exhaust oxidizing gas supplied from the power generation chamber 215 to the oxidizing gas discharge chamber 223 via an oxidizing gas discharge gap 235b described later via the oxidizing gas discharge hole 233b. It leads to an oxidizing gas discharge branch pipe (not shown). The oxidizing gas discharge branch pipe communicates with an oxidizing gas discharge pipe (not shown). The oxidant gas discharge pipe supplies the oxidant gas discharge system 15 with the oxidant gas supplied from the oxidant gas discharge branch pipe.

  The upper tube plate 225a is arranged between the top plate of the upper casing 229a and the upper heat insulator 227a so that the upper tube plate 225a, the top plate of the upper casing 229a and the upper heat insulator 227a are substantially parallel to each other. It is fixed to the side plate. The upper tube sheet 225a has a plurality of holes corresponding to the number of cell stacks 101 provided in the SOFC cartridge 203, and the cell stacks 101 are inserted into the holes, respectively. The upper tube sheet 225a hermetically supports one end of the plurality of cell stacks 101 through one or both of a sealing member and an adhesive member, and also includes a fuel gas supply chamber 217 and an oxidizing gas discharge chamber 223. And is to be isolated.

  The lower tube plate 225b is disposed on the side plate of the lower casing 229b so that the lower tube plate 225b, the bottom plate of the lower casing 229b, and the lower heat insulator 227b are substantially parallel between the bottom plate of the lower casing 229b and the lower heat insulator 227b. It is fixed. The lower tube sheet 225b has a plurality of holes corresponding to the number of cell stacks 101 provided in the SOFC cartridge 203, and the cell stacks 101 are inserted into the holes, respectively. The lower tube sheet 225b hermetically supports the other end of the plurality of cell stacks 101 through one or both of a sealing member and an adhesive member, and also includes a fuel gas discharge chamber 219 and an oxidizing gas supply chamber 221. And is to be isolated.

  The upper heat insulator 227a is disposed at the lower end of the upper casing 229a so that the upper heat insulator 227a, the top plate of the upper casing 229a and the upper tube plate 225a are substantially parallel to each other, and is fixed to the side plate of the upper casing 229a. Yes. Further, the upper heat insulator 227a is provided with a plurality of holes corresponding to the number of cell stacks 101 provided in the SOFC cartridge 203. The diameter of the hole is set larger than the outer diameter of the cell stack 101. The upper heat insulator 227a has an oxidizing gas discharge gap 235b formed between the inner surface of this hole and the outer surface of the cell stack 101 inserted through the upper heat insulator 227a.

  The upper heat insulator 227a separates the power generation chamber 215 and the oxidizing gas discharge chamber 223, and the atmosphere around the upper tube sheet 225a is heated to reduce the strength and the corrosion caused by the oxidizing agent contained in the oxidizing gas. Suppresses the increase. The upper tube sheet 225a and the like are made of a metal material having high temperature durability such as Inconel, but the upper tube sheet 225a and the like are exposed to the high temperature in the power generation chamber 215, and the temperature difference in the upper tube sheet 225a and the like becomes large. This prevents thermal deformation. The upper heat insulator 227a guides the exhaust oxidizing gas exposed to a high temperature through the power generation chamber 215 to the oxidizing gas exhaust chamber 223 through the oxidizing gas discharge gap 235b.

  According to this embodiment, due to the structure of the SOFC cartridge 203 described above, the fuel gas and the oxidizing gas flow so as to face the inside and the outside of the cell stack 101. As a result, the exhaust oxidizing gas exchanges heat with the fuel gas supplied to the power generation chamber 215 through the inside of the base tube 103, and the upper tube plate 225a made of a metal material is buckled. It is cooled to a temperature that does not cause deformation and supplied to the oxidizing gas discharge chamber 223. In addition, the temperature of the fuel gas is raised by heat exchange with the exhaust oxidizing gas discharged from the power generation chamber 215 and supplied to the power generation chamber 215. As a result, the fuel gas preheated to a temperature suitable for power generation can be supplied to the power generation chamber 215 without using a heater or the like.

  The lower heat insulator 227b is disposed at the upper end of the lower casing 229b so that the lower heat insulator 227b, the bottom plate of the lower casing 229b, and the lower tube plate 225b are substantially parallel to each other, and is fixed to the side plate of the lower casing 229b. . Also, the lower heat insulator 227b is provided with a plurality of holes corresponding to the number of cell stacks 101 provided in the SOFC cartridge 203. The diameter of the hole is set larger than the outer diameter of the cell stack 101. The lower heat insulator 227b has an oxidizing gas supply gap 235a formed between the inner surface of this hole and the outer surface of the cell stack 101 inserted through the lower heat insulator 227b.

  The lower heat insulator 227b separates the power generation chamber 215 and the oxidizing gas supply chamber 221, and the atmosphere around the lower tube sheet 225b is heated to lower the strength and corrode by the oxidizing agent contained in the oxidizing gas. Suppresses the increase. The lower tube plate 225b and the like are made of a metal material having high temperature durability such as Inconel. However, the lower tube plate 225b and the like are exposed to a high temperature and the temperature difference in the lower tube plate 225b and the like is increased, so that the heat is deformed. It is something to prevent. The lower heat insulator 227b guides the oxidizing gas supplied to the oxidizing gas supply chamber 233 to the power generation chamber 215 through the oxidizing gas supply gap 235a.

  According to this embodiment, due to the structure of the SOFC cartridge 203 described above, the fuel gas and the oxidizing gas flow so as to face the inside and the outside of the cell stack 101. As a result, the exhaust fuel gas that has passed through the power generation chamber 215 through the interior of the base tube 103 is heat-exchanged with the oxidizing gas supplied to the power generation chamber 215, and the lower tube plate 225b made of a metal material. And the like are cooled to a temperature that does not cause deformation such as buckling, and supplied to the fuel gas discharge chamber 219. The oxidizing gas is heated by heat exchange with the exhaust fuel gas and supplied to the power generation chamber 215. As a result, the oxidizing gas heated to the temperature necessary for power generation can be supplied to the power generation chamber 215 without using a heater or the like.

  The direct-current power generated in the power generation chamber 215 is led out to the vicinity of the end of the cell stack 101 by the lead film 115 made of Ni / YSZ or the like provided in the plurality of fuel cells 105, and then the current collector rod (non-current) of the SOFC cartridge 203 is used. The current is collected via a current collecting plate (not shown) to the outside of each SOFC cartridge 203. The electric power derived to the outside of the SOFC cartridge 203 by the current collector rod is connected to the generated power of each SOFC cartridge 203 in a predetermined series number and parallel number, and is derived to the outside of the SOFC module 201. It is converted into predetermined AC power by an inverter that does not, and supplied to the power load. The inverter and the power load are controlled by the control device 10 so that the resistance fluctuates so that the current flowing from the SOFC module 201 to the outside becomes equal to a predetermined current.

  As shown in FIG. 4, the cell stack 101 is formed between a cylindrical base tube 103, a plurality of fuel cells 105 formed on the outer peripheral surface of the base tube 103, and adjacent fuel cells 105. And an interconnector 107. The fuel cell 105 is formed by stacking a fuel electrode 109, a solid electrolyte 111, and an air electrode 113. The cell stack 101 is connected to the air electrode 113 of the fuel cell 105 formed at the end in the axial direction of the base tube 103 among the plurality of fuel cells 105 formed on the outer peripheral surface of the base tube 103. A lead film 115 is electrically connected through the connector 107.

The base tube 103 is made of a porous material, and is made of, for example, CaO stabilized ZrO ₂ (CSZ), Y ₂ O ₃ stabilized ZrO ₂ (YSZ), or MgAl ₂ O ₄ . The base tube 103 supports the fuel battery cell 105, the interconnector 107, and the lead film 115, and supplies the fuel gas supplied to the inner peripheral surface of the base tube 103 through the pores of the base tube 103. Is diffused to the fuel electrode 109 formed on the outer peripheral surface of the electrode.

The fuel electrode 109 is made of an oxide of a composite material of Ni and a zirconia-based electrolyte material. For example, Ni / YSZ is used. In this case, in the fuel electrode 109, Ni that is a component of the fuel electrode 109 has a catalytic action on the fuel gas. This catalytic action reacts with a fuel gas supplied through the base tube 103, for example, a mixed gas of methane (CH ₄ ) and water vapor, and reforms it into hydrogen (H ₂ ) and carbon monoxide (CO). Is. Further, the fuel electrode 109 has an interface between the solid electrolyte 111 and hydrogen (H ₂ ) and carbon monoxide (CO) obtained by reforming and oxygen ions (O ²⁻ ) supplied via the solid electrolyte 111. It reacts electrochemically in the vicinity to produce water (H ₂ O) and carbon dioxide (CO ₂ ). At this time, the fuel cell 105 generates electric power by electrons emitted from oxygen ions.

The solid electrolyte 111 is mainly made of YSZ having gas tightness that prevents gas from passing through and high oxygen ion conductivity at high temperatures. The solid electrolyte 111 moves oxygen ions (O ²⁻ ) generated at the air electrode to the fuel electrode.

The air electrode 113 is made of, for example, a LaSrMnO ₃ oxide or a LaCoO ₃ oxide. The air electrode 113 generates oxygen ions (O ²⁻ ) by dissociating oxygen in an oxidizing gas such as air supplied near the interface with the solid electrolyte 111.

The interconnector 107 is composed of a conductive perovskite oxide represented by M _1-x L _x TiO ₃ (M is an alkaline earth metal element, L is a lanthanoid element) such as SrTiO ₃ system, and is composed of fuel gas and oxidation It is a dense film so that it does not mix with sex gases. Further, the interconnector 107 has stable electrical conductivity in both an oxidizing atmosphere and a reducing atmosphere. The interconnector 107 electrically connects the air electrode 113 of one fuel battery cell 105 and the solid electrolyte 111 of the other fuel battery cell 105 in adjacent fuel battery cells 105, so that the adjacent fuel battery cells 105 are connected to each other. Are connected in series. Since the lead film 115 needs to have electronic conductivity and a thermal expansion coefficient close to that of other materials constituting the cell stack 101, the lead film 115 is made of Ni such as Ni / YSZ and a zirconia-based electrolyte material. Composed of composite material. The lead film 115 leads direct current power generated by the plurality of fuel cells 105 connected in series by the interconnector to the vicinity of the end of the cell stack 101.

  The fuel cell system 1 further includes a thermometer and an ammeter. The thermometer measures the temperature of the power generation chamber 215 in which the fuel electrode 109 is disposed by being controlled by the control device 10. The ammeter measures the current flowing from the SOFC module 201 to the power load that consumes the power generated by the SOFC module 201 under the control of the control device 10. The electric load fluctuates as a result of being controlled by the control device 10.

  FIG. 5 shows the control device 10. The control device 10 is a computer, and includes a CPU, a storage device, a memory drive, a communication device, and an interface (not shown). The CPU executes a computer program installed in the control device 10 to control the storage device, the removable memory drive, the communication device, and the interface. The storage device records the computer program. The storage device further records information used by the CPU. The removable memory drive is used when the computer program is installed in the control device 10 when a recording medium in which the computer program is recorded is inserted. The communication device is used when a computer program is downloaded to the control device 10 from another computer connected to the control device 10 via a communication line network, and the computer program is installed in the control device 10.

  The interface outputs information generated by an external device connected to the control apparatus 10 to the CPU, and outputs information generated by the CPU to the external device. The external equipment includes a fuel supply device 5, a water vapor supply device 6, a reducing gas supply device 7, and an inert gas supply device 8, and includes a thermometer, an ammeter, and a power load (not shown).

  The computer program installed in the control device 10 is formed of a plurality of computer programs for causing the control device 10 to realize a plurality of functions. The plurality of functions include a temperature measurement unit 31, a current measurement unit 32, a supply preparation unit 33, a supply start unit 34, a power generation start unit 35, and a rated operation unit 36.

  The temperature measurement unit 31 performs control so that the temperature of the fuel electrode 109 is measured by a thermometer installed in the power generation chamber 215 where the fuel electrode 109 is disposed so that the temperature of the fuel electrode 109 is intermittently measured. In addition, when a plurality of thermometers are installed in consideration of the temperature distribution in the power generation chamber 215, an average value may be calculated as necessary. The current measuring unit 32 controls the current flowing from the SOFC module 201 to be measured by an ammeter provided in an inverter (not shown) so that the current flowing from the SOFC module 201 to the power load is intermittently measured.

  The supply preparation unit 33 operates when the temperature measured by the temperature measurement unit 31 is 400 ° C. or lower. The supply preparation unit 33 controls the power load so that no current flows from the SOFC module 201 to the power load. The supply preparation unit 33 further controls the fuel supply device 5 so that the city gas is not supplied to the fuel supply system 11. The supply preparation unit 33 further controls the water vapor supply device 6 so that the water vapor is not supplied to the fuel supply system 11. The supply preparation unit 33 further controls the reducing gas supply device 7 so that hydrogen is supplied to the fuel supply system 11. The supply preparation unit 33 further controls the inert gas supply device 8 so that nitrogen is supplied to the fuel supply system 11. The supply preparation unit 33 further supplies the reducing gas so that the ratio of the supply amount of hydrogen supplied to the fuel supply system 11 and the supply amount of nitrogen supplied to the fuel supply system 11 is equal to a predetermined ratio. The apparatus 7 and the inert gas supply apparatus 8 are controlled.

  The supply start unit 34 operates when the temperature measured by the temperature measurement unit 31 is 400 ° C. or higher and when the temperature is 800 ° C. or lower. The supply start unit 34 controls the power load so that no current flows from the SOFC module 201 to the power load. The supply start unit 34 further controls the reducing gas supply device 7 so that hydrogen is not supplied to the fuel supply system 11. The supply start unit 34 further controls the fuel supply device 5 so that the city gas is supplied to the fuel supply system 11. The supply start unit 34 further controls the water vapor supply device 6 so that the water vapor is supplied to the fuel supply system 11. Further, the supply start unit 34 makes the ratio of the supply amount of the city gas supplied to the fuel supply system 11 and the supply amount of the water supply supplied to the fuel supply system 11 equal to a predetermined ratio. That is, the amount of water vapor (molar amount of water vapor molecules) contained in the mixed gas in which the water vapor supplied by the fuel supply system 11 and the city gas are mixed is the amount of carbon (molar amount of carbon atoms) contained in the mixed gas. The fuel supply device 5 and the water vapor supply device 6 are controlled so that the divided S / C ratio (Steam / Carbon ratio) is 5 or more.

  The power generation start unit 35 operates when the temperature measured by the temperature measurement unit 31 is 800 ° C. or higher and when the temperature is 1000 ° C. or lower. The power generation start unit 35 controls the power load so that the current flowing from the SOFC module 201 to the power load gradually increases. In other words, when the temperature is raised to about 1000 ° C., which is the predetermined temperature during rated operation, the temperature of the fuel cell is raised using the internal exothermic reaction by gradually increasing the current flowing from the fuel cell to the power load. Can be made. The power generation start unit 35 further calculates a water vapor supply amount based on the current measured by the current measurement unit 32. The water vapor supply amount increases as the current increases. The power generation start unit 35 further controls the water vapor supply device 6 so that the supply amount of water vapor supplied to the SOFC module 201 per unit time is equal to the water vapor supply amount calculated based on the current. The power generation start unit 35 further controls the fuel supply system 11 so that the ratio of the supply amount of city gas supplied to the fuel supply system 11 and the supply amount of water vapor supplied to the fuel supply system 11 is equal to a predetermined ratio, that is, the fuel S / C ratio (Steam / Carbon ratio) obtained by dividing the amount of water vapor (molar amount of water vapor molecules) contained in the mixed gas supplied by the supply system 11 by the amount of carbon (molar amount of carbon atoms) contained in the mixed gas The fuel supply device 5 and the water vapor supply device 6 are controlled so as to be 5 or less.

  The rated operation unit 36 operates when the temperature measured by the temperature measurement unit 31 is 700 ° C. or higher and the temperature is 1000 ° C. or lower. The rated operation unit 36 controls the water vapor supply device 6 so that water vapor is not supplied from the water vapor supply device 6 to the fuel supply system 11. The rated operation unit 36 further controls the reducing gas supply device 7 so that hydrogen is not supplied from the reducing gas supply device 7 to the fuel supply system 11. The rated operation unit 36 further controls the inert gas supply device 8 so that nitrogen is not supplied from the inert gas supply device 8 to the fuel supply system 11. The rated operation unit 36 further controls the fuel supply device 5 so that a predetermined amount of city gas is supplied to the fuel supply system 11 per unit time.

  The embodiment of the fuel cell operation method is executed by the fuel cell system 1 and includes a supply preparation operation, a supply start operation, a power generation start operation, and a rated operation.

  The supply preparation operation is started when the fuel cell system 1 is stopped. First, as the micro gas turbine 3 operates, the oxidizing gas generated by the micro gas turbine 3 is supplied to the SOFC module 201 via the oxidizing gas supply system 12. At this time, the SOFC module 201 heats the power generation chamber 215 by supplying the oxidizing gas to the power generation chamber 215.

  The control device 10 intermittently measures the temperature of the power generation chamber 215 in which the fuel electrode 109 is disposed by controlling the thermometer. When the temperature measured by the thermometer is 400 ° C. or less, the control device 10 controls the power load to stop the SOFC module 201 from generating power. The control device 10 further controls the fuel supply device 5 and the water vapor supply device 6 to stop the city gas and the water vapor from being supplied to the fuel supply system 11. The control device 10 further controls the reducing gas supply device 7 and the inert gas supply device 8, thereby supplying hydrogen to the fuel supply system 11 and nitrogen to the fuel supply system 11. Hydrogen and nitrogen are supplied to the fuel supply system 11 so that the ratio with the supply amount becomes equal to a predetermined ratio. As an example of a predetermined ratio (ratio between the hydrogen supply amount and the nitrogen supply amount), it is desirable that hydrogen: nitrogen supply hydrogen at a ratio of 5:95 or less. Alternatively, it is desirable that the hydrogen concentration in the exhaust fuel from the SOFC is 0.01% or more (only a little hydrogen is required in the exhaust fuel system). This is because the oxidizing reaction of the reducing gas occurs in the cell as the temperature rises. Note that the amount of reducing gas consumed varies depending on the cell temperature.

  At this time, the fuel supply system 11 supplies a mixed gas in which hydrogen and nitrogen are mixed to the fuel electrode 109 of the SOFC module 201 by supplying hydrogen and nitrogen. In the SOFC module 201, when the mixed gas is supplied, the fuel electrode 109 is disposed in a reducing atmosphere formed from the mixed gas, and the fuel electrode 109 is held in a reduced state. Furthermore, in the SOFC module 201, when the temperature of the power generation chamber 215 is 400 ° C. or lower, water vapor is not supplied to the fuel electrode 109, thereby preventing the fuel electrode 109 from condensing. Note that when the temperature of the power generation chamber 215 is approximately 100 ° C. or lower, there is no need to maintain the reduced state, and the supply of hydrogen may be stopped.

  The supply start operation is started when the temperature measured by the thermometer becomes 400 ° C. or higher after the supply preparation operation is started. The micro gas turbine 3 continues to heat the power generation chamber 215 of the SOFC module 201 by supplying the oxidizing gas to the SOFC module 201 via the oxidizing gas supply system 12. The control device 10 stops the power generation of the SOFC module 201 by controlling the power load. The control device 10 further stops supplying hydrogen to the fuel supply system 11 by controlling the reducing gas supply device 7. The control device 10 further controls the fuel supply device 5 and the water vapor supply device 6 to thereby supply a supply amount of city gas to the fuel supply system 11 and a supply amount of water vapor to the fuel supply system 11. Is equal to a predetermined ratio, that is, the S / C ratio is obtained by dividing the amount of water vapor containing the water vapor in the mixed gas generated by the fuel supply system 11 by the amount of carbon containing the carbon in the mixed gas. City gas and water vapor are supplied to the fuel supply system 11 so as to be 5 or more.

  At this time, the fuel supply system 11 supplies the gas mixture of the city gas and water vapor to the fuel electrode 109 of the SOFC module 201 by supplying the city gas and water vapor. In the SOFC module 201, when the temperature of the power generation chamber 215 is 400 ° C. or higher, the reformed reaction using the fuel electrode 109 as a catalyst proceeds by supplying the mixed gas to the fuel electrode 109. Hydrogen is generated from the water vapor and the fuel gas. At this time, the fuel electrode 109 is arranged in a reducing atmosphere by the generated hydrogen and is held in a reduced state. For this reason, hydrogen can be supplied to the fuel electrode 109 by supplying the fuel, and the supply of hydrogen becomes unnecessary, so that the amount of hydrogen used in the hydrogen cylinder can be greatly reduced. As a result, the running cost can be reduced.

The power generation start operation is started when the temperature measured by the thermometer is 800 ° C. or higher after the supply start operation is started. By continuing to operate, the micro gas turbine 3 supplies the oxidizing gas to the SOFC module 201 via the oxidizing gas supply system 12 to heat the power generation chamber 215 of the SOFC module 201. First, the control device 10 controls the power load to gradually increase the current flowing from the SOFC module 201 to the power load (for example, at 10 mA / cm ² · min).

  Further, the control device 10 intermittently measures the current flowing from the SOFC module 201 to the power load by controlling the ammeter. The control device 10 further calculates a water vapor supply amount based on the current. The water vapor supply amount increases as the current increases. The control device 10 further controls the water vapor supply device 6 so that the supply amount of water vapor supplied to the fuel supply system 11 per unit time is equal to the water supply amount of the water vapor. To supply. The control device 10 further controls the fuel supply device 5 so that the ratio between the supply amount of the city gas supplied to the fuel supply system 11 and the supply amount of the steam supplied to the fuel supply system 11 is a predetermined ratio. In other words, the S / C ratio obtained by dividing the amount of water vapor containing the water vapor in the mixed gas produced by the fuel supply system 11 by the amount of carbon containing the carbon in the mixed gas is 5 or less. The city gas is supplied to the fuel supply system 11.

  In the power generation start operation, the amount of water vapor contained in the exhaust fuel gas exhausted from the SOFC module 201 is larger than in other power generation start operations in which a mixed gas of hydrogen and nitrogen is supplied to the fuel electrode 109. In addition, even when the current flowing through the power load is increased faster (about three times), the fuel electrode 109 can be maintained in the reduced state. According to such a power generation start operation, the SOFC module 201 can further generate power more efficiently because the S / C ratio is 5 or less in the power generation start operation.

The rated operation is started when the current flowing from the SOFC module 201 to the power load reaches a predetermined current (for example, 100 mA / cm ² ) after the power generation start operation is executed. The control device 10 stops the supply of water vapor to the fuel supply system 11 by controlling the water vapor supply device 6. The control device 10 further controls the reducing gas supply device 7 to stop the supply of hydrogen from the reducing gas supply device 7 to the fuel supply system 11. The control device 10 further stops the supply of nitrogen from the inert gas supply device 8 to the fuel supply system 11 by controlling the inert gas supply device 8. The control device 10 further controls the fuel supply device 5 to supply a predetermined amount of city gas to the fuel supply system 11 per unit time.

  When the rated operation is started, the SOFC module 201 can appropriately generate power by the rated operation because the fuel electrode 109 is held in the reduced state by the power generation start operation.

  According to such a fuel cell operation method, the fuel cell system 1 is configured so that the exhaust gas exhausted from the SOFC module 201 is compared with other power generation start operations in which a mixed gas of hydrogen and nitrogen is supplied to the fuel electrode 109. Since the amount of water vapor contained in the fuel gas is large, the fuel electrode 109 can be maintained in the reduced state even when the current flowing through the power load is increased more quickly (about three times). Therefore, according to such a fuel cell operation method, the fuel cell system 1 can increase the current flowing through the power load at a higher speed, and can further shorten the period during which the current is increased. Rated operation can be started earlier.

  According to such a fuel cell operation method, further, hydrogen is not supplied to the SOFC module 201 in the supply start operation, so that compared to other supply start operations in which hydrogen is supplied to the SOFC module 201, Running cost can be reduced. According to such a fuel cell operation method, when the SOFC module 201 performs the power generation start operation and the rated operation because the nitrogen is not supplied to the SOFC module 201 in the supply start operation, The nitrogen concentration in the atmosphere around the pole 109 can be reduced, the fuel concentration can be increased, and power can be generated more efficiently.

  According to such a fuel cell operation method, the SOFC module 201 further prevents the carbon from being deposited on the fuel electrode 109 when the S / C ratio is 5 or more in the supply start operation. Thus, when the SOFC module 201 generates power, current is prevented from leaking due to the deposited carbon.

  The fuel cell operation method according to the present invention can start the rated operation earlier in the same manner even when the operation performed by the control device 10 is performed by a person.

  The supply start operation is another supply that supplies city gas and water vapor so that the S / C ratio is less than 5 when the fuel electrode 109 is sufficiently prepared for carbon deposition. It can also be replaced by a start operation. The fuel cell operation method to which such a supply start operation is applied can also start the rated operation earlier in the same manner as the fuel cell operation method in the above-described embodiment.

  The reducing gas supply device 7 can be omitted. In the fuel cell system in which the reducing gas supply device 7 is omitted, the supply of hydrogen to the SOFC module 201 is omitted. Such a fuel cell system can start rated operation earlier in the same manner as the fuel cell system 1 in the above-described embodiment. Such a fuel cell system can be handled more easily than the fuel cell system 1 in the above-described embodiment because the reducing gas supply device 7 is omitted.

City gas can be replaced with other fuels. Examples of the fuel include hydrocarbon gases such as hydrogen (H ₂ ), carbon monoxide (CO), and methane (CH ₄ ), and gas produced by a gasification facility for carbonaceous materials such as coal. The fuel cell system to which such a fuel is applied can also start rated operation earlier in the same manner as the fuel cell system 1 in the above-described embodiment.

  Note that the fuel cell system 1 can be used alone without being applied to the combined power generation system 2. The fuel cell system 1 can start rated operation earlier even when used alone.

  The oxidizing gas supplied to the fuel cell system 1 can be replaced with another oxidizing gas different from the compressed air. Examples of the oxidizing gas include a mixed gas of combustion exhaust gas and air, a mixed gas of oxygen and air, and the like. The fuel cell system to which such an oxidizing gas is applied can also start rated operation earlier in the same manner as the fuel cell system 1 in the above-described embodiment.

DESCRIPTION OF SYMBOLS 1 Fuel cell system 5 Fuel supply apparatus 6 Water vapor supply apparatus 7 Reducing gas supply apparatus 8 Inert gas supply apparatus 10 Control apparatus 109 Fuel electrode 113 Air electrode 215 Power generation chamber

Claims (10)

A fuel cell having an air electrode and a fuel electrode;
A fuel supply device for supplying fuel gas to the fuel electrode;
A water vapor supply device for supplying water vapor to the fuel electrode;
Before the fuel cell generates power, when the temperature of the power generation chamber in which the fuel electrode is disposed becomes equal to or higher than a predetermined temperature at which the fuel gas can be reformed to generate hydrogen, the water vapor, the fuel gas, A fuel cell system comprising: a control device that controls the fuel supply device and the water vapor supply device so that the mixed gas mixed at a predetermined flow ratio is started to be supplied to the fuel electrode.   The fuel cell system according to claim 1, wherein the predetermined temperature is 400 degrees or more.   The control device further includes the fuel supply device such that the S / C ratio obtained by dividing the predetermined flow rate ratio by the amount of water vapor contained in the mixed gas by the amount of carbon contained in the mixed gas is 5 or more. The fuel cell system according to claim 1 or 2, which controls the water vapor supply device. A thermometer for measuring the temperature of the power generation chamber in which the fuel electrode is disposed;
The said control apparatus controls the said fuel supply apparatus and the said water vapor supply apparatus so that the said mixed gas is supplied to the said fuel electrode at the timing determined based on the said temperature. The fuel cell system described in any one of them.   In the control device, when the fuel cell is generating electric power, the predetermined flow rate ratio is an S / C ratio obtained by dividing an amount of water vapor contained in the mixed gas by an amount of carbon contained in the mixed gas. The fuel cell system according to any one of claims 1 to 4, wherein the fuel supply device and the water vapor supply device are controlled to be 5 or less. A power load measuring device for measuring a current flowing from the fuel cell to a power load that consumes the power generated by the fuel cell;
When the fuel cell is generating electric power, the control device is configured so that the amount of water vapor supplied to the fuel electrode per unit time is equal to the amount of water vapor calculated based on the current. The fuel cell system according to any one of claims 1 to 5, further controlling the water vapor supply device. A reducing gas supply device for supplying reducing gas to the fuel electrode;
The controller is further below the predetermined temperature,
Controlling the reducing gas supply device so that the reducing gas is supplied to the fuel electrode in at least one period before the mixed gas is supplied to the fuel electrode;
The said reducing gas supply apparatus is controlled as described in any one of Claims 1-6 which controls the said reducing gas so that the said reducing gas is not supplied to the said fuel electrode when the said mixed gas is supplied. Fuel cell system. An inert gas supply device for supplying an inert gas to the fuel electrode;
The control device is configured to supply the inert gas to the fuel electrode when the mixed gas is supplied to the fuel electrode, and when the mixed gas is supplied to the fuel electrode. The supply amount of the inert gas supplied to the fuel electrode is smaller than the supply amount of the inert gas supplied to the fuel electrode before the mixed gas is supplied to the fuel electrode. The fuel cell system according to claim 7, wherein the inert gas supply device is controlled.   The control device supplies the reducing gas so that the reducing gas is not supplied to the fuel electrode when the fuel cell is generating power and the current flowing through the power load reaches a predetermined current. The fuel cell system according to claim 8, wherein the inert gas supply device is controlled so that the device is controlled so that the inert gas is not supplied to the fuel electrode. A fuel cell having an air electrode and a fuel electrode supplied with oxygen;
A fuel supply device for supplying fuel gas to the fuel electrode;
A fuel cell operating method executed using a fuel cell system comprising a water vapor supply device for supplying water vapor to the fuel electrode;
Before the fuel cell generates power, when the temperature of the power generation chamber in which the fuel electrode is disposed becomes equal to or higher than a predetermined temperature at which the fuel gas can be reformed to generate hydrogen, the water vapor, the fuel gas, Controlling the fuel supply device and the water vapor supply device so that the mixed gas mixed at a predetermined flow ratio is started to be supplied to the fuel electrode,
A fuel cell operating method comprising: generating power after the mixed gas is supplied to the fuel electrode.

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