JP2020013660A - Fuel cell module and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell module and a program capable of individually controlling the temperature of a reforming section at the time of starting a fuel cell or at the time of power generation. A fuel cell module (100) vaporizes a tubular member (10) having a heat insulating space (14) formed by a tubular outer peripheral wall (12), an oxidant gas flow channel (20) through which an oxidant gas (G1) flows, and a raw fuel (G2). To form a raw fuel gas, a reforming section 40 provided with a reforming catalyst layer 42 for producing a reformed gas G4 from the raw fuel gas, and a cylindrical housing for housing a fuel cell stack 52. At least one of the portion 50, the plurality of oxidant gas supply pipes 90 provided along the flow direction of the oxidant gas G1 in the oxidant gas flow passage 20, and the fuel cell stack 52 at the time of startup and power generation, A control unit that controls the temperature of the reforming unit 40 by adjusting the amount of the oxidant gas G1 distributed to each of the plurality of oxidant gas supply pipes 90. [Selection diagram] Figure 1

Description

  The present invention relates to a fuel cell module and a program.

  2. Description of the Related Art Conventionally, as one of the fuel cell modules, a solid oxide fuel cell (SOFC) having excellent power generation efficiency and operating at a high temperature is known. This SOFC includes a cell stack that generates power by an electrochemical reaction between a reformed gas obtained by steam reforming a hydrocarbon-based raw fuel gas using water for reforming and an oxidizing gas such as air.

  For example, Patent Literature 1 discloses a fuel cell that controls the temperature of air introduced into a cell stack. The fuel cell includes a cell stack formed by stacking a plurality of power generation cells that generate power by reacting fuel and air, a combustor that generates heat by burning exhaust fuel and exhaust air discharged from the cell stack, It has. In addition, this fuel cell generates a reformed fuel by steam reforming a fuel introduced from the outside using heat generated in a combustor, and supplies the reformed fuel to a cell stack. And an air preheater that heats air introduced from the outside with heat generated in the combustor and supplies the air to the cell stack. The fuel cell is supplied to the cell stack by adjusting the flow ratio of the flow rate of the air heated by the air preheater to the flow rate of the air bypassing the air preheater and directly introduced into the cell stack. An air temperature control mechanism for controlling the temperature of the air to be supplied is provided.

JP 2012-198994 A

By the way, it is desirable that the temperature of the reforming unit can be individually controlled at the time of starting the fuel cell or at the time of power generation. For example, during startup of the fuel cell, the water reforming, the temperature inside the cell stack there is a limitation that can not be supplied to above the temperature T _CS below which condensation of water vapor occurs. When the reforming water cannot be supplied, the hydrocarbon fuel heated to a high temperature in the reforming section is decomposed, and carbon deposition may occur. Therefore, until the temperature inside the cell stack exceeds a temperature T _CS, the temperature of the reforming unit must be less than the temperature for starting the carbon deposition. Further, during power generation of the fuel cell, the temperature inside the reforming section becomes excessively high, and the reforming catalyst in the reforming section may be damaged. For this reason, it is necessary to suppress excessive temperature rise in the reforming section.

  However, according to the technology described in Patent Document 1, by controlling the temperature of the air introduced into the cell stack, it is possible to avoid damage to the power generation cell due to rapid heating at the time of startup. No consideration is given to individually controlling the temperature of the material part.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a fuel cell module and a program that can individually control the temperature of a reforming unit at the time of starting or generating power of a fuel cell. And

  In order to achieve the above object, the fuel cell module according to claim 1 is provided with a cylindrical member having a heat insulating space formed by a cylindrical outer peripheral wall, and provided coaxially with the outer peripheral wall so as to surround the outer peripheral wall. An oxidizing gas flow path through which an oxidizing gas flows, and a vaporizing unit provided between the oxidizing gas flow path and the cylindrical member, and configured to vaporize a raw fuel and generate a raw fuel gas. And provided between the oxidizing gas flow path and the tubular member on the downstream side of the vaporizing section along the flow direction in which the oxidizing gas flows, and, from the raw fuel gas, the reformed gas. A reforming section provided with a reforming catalyst layer for generation, and an electrochemical reaction between the oxidizing gas and the reformed gas, the reforming section being provided downstream of the reforming section along the flow direction. A cylindrical accommodating portion for accommodating a fuel cell stack for generating electricity by A plurality of oxidizing gas supply pipes provided along the flow direction of the oxidizing gas flow path; and at least one of the start-up and power generation of the fuel cell stack, each of the plurality of oxidizing gas supply pipes. A control unit that controls the temperature of the reforming unit by adjusting the amount of the oxidizing gas to be distributed.

  According to the fuel cell module of the first aspect, it is possible to individually control the temperature of the reforming unit when the fuel cell is started or when power is generated.

  Further, in the fuel cell module according to the second aspect, in the invention according to the first aspect, the plurality of oxidizing gas supply pipes are located at positions corresponding to an upstream end of the vaporization unit in the flow direction. An oxidizing gas first supply pipe provided, and an oxidizing gas provided at a position corresponding to the vaporizing section or the reforming section downstream of the oxidizing gas first supply pipe along the flow direction. A second supply pipe.

  According to the fuel cell module of the second aspect, the temperature of the reforming section is more appropriately controlled as compared with the case where the second oxidizing gas supply pipe is not provided corresponding to the vaporizing section or the reforming section. be able to.

  In the fuel cell module according to the third aspect, in the invention according to the second aspect, the control unit may be configured such that, when the fuel cell stack is started, the temperature of the reforming unit is lower than the first temperature. When the temperature rises to a predetermined threshold temperature, the amount of the oxidizing gas distributed to the oxidizing gas second supply pipe is increased, and the amount of the oxidizing gas distributed to the oxidizing gas first supply pipe is decreased. Thereby, the temperature of the reforming unit is controlled to be lower than the first temperature until the temperature of the fuel cell stack exceeds a second temperature lower than the threshold temperature.

  According to the fuel cell module of the third aspect, it is possible to more appropriately control the temperature of the reforming unit when the fuel cell is started, as compared with a case where the first temperature and the second temperature are not considered. .

  Further, in the fuel cell module according to the fourth aspect, in the invention according to the third aspect, the first temperature is a temperature at which precipitation of carbon starts in the reforming section, and the second temperature is the second temperature. The upper limit temperature at which condensation of water vapor occurs in the fuel cell stack.

  According to the fuel cell module of the fourth aspect, it is possible to suppress the deposition of carbon in the reforming unit at the time of starting the fuel cell, as compared with the case where the first temperature and the second temperature are not considered. .

  Further, in the fuel cell module according to claim 5, in the invention according to claim 3 or 4, the control unit is configured to perform the reforming when the temperature of the fuel cell stack is equal to or lower than the second temperature. Supplying the raw fuel containing no water to the vaporizing unit, and supplying the raw fuel containing reforming water to the vaporizing unit when the temperature of the fuel cell stack exceeds the second temperature; Is further performed.

  According to the fuel cell module of the fifth aspect, as compared with the case where the second temperature is not considered, the water for reforming can be more appropriately vaporized to obtain steam.

  In the fuel cell module according to claim 6, in the invention according to claim 2, the number of the oxidizing gas second supply pipes is plural, and each of the plurality of oxidizing gas second supply pipes is It is provided at a position downstream of the oxidant gas first supply pipe along the flow direction and corresponding to each of the vaporizing section and the reforming section.

  According to the fuel cell module of the sixth aspect, the temperature of the reforming section can be more appropriately controlled as compared with the case where the plurality of oxidant gas second supply pipes are not provided.

  In the fuel cell module according to the seventh aspect, in the invention according to the sixth aspect, the control unit may be configured such that the temperature of the reforming unit is lower than the first temperature when the fuel cell stack is started. When the temperature rises to a predetermined threshold temperature, the entire amount of the oxidizing gas is distributed to the oxidizing gas second supply pipe provided at a position corresponding to the vaporizing section, and thereafter, the temperature of the reforming section rises. Is continued, the distribution of the oxidizing gas to the oxidizing gas second supply pipe provided at the position corresponding to the reforming section is started, so that the temperature of the fuel cell stack becomes higher than the threshold temperature. The temperature of the reforming section is controlled to be lower than the first temperature until the temperature exceeds the lower second temperature.

  According to the fuel cell module of the seventh aspect, compared to a case where the first temperature and the second temperature are not considered without providing the plurality of oxidant gas second supply pipes, It is possible to more appropriately control the temperature of the reforming section.

  Further, in the fuel cell module according to claim 8, in the invention according to claim 2, the control unit is configured such that the temperature of the reforming unit is lower than a third temperature during power generation of the fuel cell stack. When the temperature rises to a predetermined threshold temperature, the amount of the oxidizing gas distributed to the oxidizing gas second supply pipe is increased, and the amount of the oxidizing gas distributed to the oxidizing gas first supply pipe is decreased. By controlling the temperature, the temperature of the reforming section is controlled to be lower than the third temperature.

  According to the fuel cell module of the eighth aspect, the temperature of the reforming section can be more appropriately controlled during the power generation of the fuel cell as compared with the case where the third temperature is not considered.

  In the fuel cell module according to the ninth aspect, in the invention according to the eighth aspect, the third temperature is a temperature at which the reforming catalyst layer is damaged.

  According to the fuel cell module of the ninth aspect, it is possible to prevent the reforming catalyst from being damaged in the reforming unit during power generation of the fuel cell, as compared with the case where the third temperature is not considered.

  According to a tenth aspect of the present invention, in the fuel cell module according to the second aspect, the plurality of oxidizing gas supply pipes correspond to upstream ends of the fuel cell stack in the flow direction. An oxidizing gas third supply pipe is further provided at the location.

  According to the fuel cell module of the tenth aspect, it is possible to more appropriately control the temperature of the reforming section as compared with a case where the third oxidant gas supply pipe is not provided corresponding to the fuel cell stack. it can.

  In the fuel cell module according to the eleventh aspect, in the invention according to the tenth aspect, the control unit does not increase the temperature of the reforming unit to the fourth temperature during power generation of the fuel cell stack. In this case, the amount of the oxidizing gas distributed to the third oxidizing gas supply pipe is increased, and the amount of the oxidizing gas distributed to at least one of the first oxidizing gas supply pipe and the second oxidant gas supply pipe is increased. The temperature of the reforming section is controlled to be equal to or higher than the fourth temperature by decreasing the amount.

  According to the fuel cell module of the eleventh aspect, it is possible to more appropriately control the temperature of the reforming unit during power generation of the fuel cell as compared with a case where the fourth temperature is not considered.

  In a fuel cell module according to a twelfth aspect, in the invention according to the eleventh aspect, the fourth temperature is a temperature at which a reforming ratio in the reforming section is equal to or higher than a reference value.

  According to the fuel cell module of the twelfth aspect, it is possible to perform the reforming in the reforming unit with higher efficiency during the power generation of the fuel cell as compared with the case where the fourth temperature is not considered.

  A fuel cell module according to a thirteenth aspect is the fuel cell module according to any one of the first to twelfth aspects, wherein the portion between the tubular member and the vaporizing portion and between the tubular member and the reforming portion are provided. And a flue gas flow path through which flue gas obtained by burning the stack flue gas discharged from the fuel cell stack flows, and the vaporizing section heats the flue gas. The raw fuel is vaporized using the heat, and the reforming section heats the reforming catalyst layer using the heat of the combustion exhaust gas.

  According to the fuel cell module according to the thirteenth aspect, the structure of the module can be reduced in size as compared with the case where the combustion exhaust gas is not used.

  Further, in order to achieve the above object, a program described in claim 14 causes a computer to function as a control unit included in the fuel cell module according to any one of claims 1 to 13.

  According to the program described in claim 14, the same effects as those of the fuel cell module according to any one of claims 1 to 13 can be obtained.

  As described above in detail, according to the present invention, the temperature of the reforming unit can be individually controlled at the time of starting the fuel cell or at the time of power generation.

It is a longitudinal section showing an example of the structure of the fuel cell module concerning an embodiment. FIG. 2 is a cross-sectional view illustrating an example of the structure of the fuel cell module according to the embodiment. FIG. 2 is a cross-sectional view illustrating an example of the structure of the fuel cell module according to the embodiment. It is a block diagram showing an example of the electric composition of the fuel cell module concerning an embodiment. 5 is a flowchart illustrating an example of a process flow according to a temperature control processing program when the fuel cell module according to the embodiment is activated. 5 is a timing chart of a start-up operation control executed when the fuel cell module according to the embodiment is started. 4 is a flowchart illustrating an example of a flow of processing by a temperature control processing program when the fuel cell module according to the embodiment generates power. 9 is a flowchart illustrating another example of the flow of processing by the temperature control processing program when the fuel cell module according to the embodiment generates power.

  Hereinafter, an example of an embodiment for carrying out the present invention will be described in detail with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing an example of the structure of the fuel cell module 100 according to the present embodiment.
2 and 3 are cross-sectional views illustrating an example of the structure of the fuel cell module 100 according to the present embodiment. FIG. 2 shows a cross section XX of the fuel cell module 100 shown in FIG. 1, and FIG. 3 shows a YY cross section of the fuel cell module 100 shown in FIG.

  As shown in FIGS. 1 to 3, the fuel cell module 100 according to the present embodiment includes a tubular member 10, an oxidizing gas flow path 20, a vaporizing section 30, a reforming section 40, and a storage section 50. , A flue gas passage 60, a combustion section 70, a flue gas discharge pipe 80, a raw fuel supply pipe 82, a plurality of oxidizing gas supply pipes 90, and a heat insulating material 78. The plurality of oxidant gas supply pipes 90 according to the present embodiment include an oxidant gas first supply pipe 91, a plurality of (three in this embodiment) oxidant gas second supply pipes 92A to 92C, and an oxidant. It is constituted by a third gas supply pipe 93.

  In this embodiment, a case where five oxidizing gas supply pipes 90 are provided will be described. However, at least one of the oxidizing gas first supply pipe 91 and the oxidizing gas second supply pipes 92A to 92C is described. It is sufficient that one and one are included. That is, it is sufficient that at least two oxidizing gas supply pipes 90 are provided.

  In the tubular member 10, a heat insulating space 14 is formed by a cylindrical outer peripheral wall 12. As the cylindrical shape here, a cylindrical shape, an elliptical cylindrical shape, or the like is applied as an example, but may be a rectangular cylindrical shape, a triangular cylindrical shape, or the like. Although the heat insulating space 14 is hollow here, it may be filled with a heat insulating material (not shown). As an example, the cylindrical member 10 according to the present embodiment has a shape that is long in the vertical direction (the vertical direction in FIG. 1).

  The oxidant gas flow path 20 surrounds the outer peripheral wall 12 and is provided coaxially with the outer peripheral wall 12. The oxidizing gas passage 20 is a passage through which the oxidizing gas G1 such as air flows, and is connected to the fuel cell stack 52 housed in the housing 50. In the oxidizing gas flow path 20, along the flow direction of the oxidizing gas G1 (direction from top to bottom in FIG. 1), toward the outside in the radial direction (left-right direction in FIG. 1) of the tubular member 10. A plurality of oxidizing gas supply pipes 90 extending are provided.

  The vaporizing section 30 is provided between the oxidizing gas flow path 20 and the cylindrical member 10. A raw fuel supply pipe 82 extending radially outward of the tubular member 10 is provided at an upper end of the vaporization section 30. The vaporizing section 30 vaporizes the raw fuel G2 supplied from the raw fuel supply pipe 82 to generate a raw fuel gas. As the raw fuel G2, for example, a fuel containing a hydrocarbon-based gas that is a hydrocarbon-based gas or a hydrocarbon-based liquid such as city gas or biogas, and water for reforming is used.

  The reforming section 40 is provided downstream of the vaporizing section 30 along the flow direction of the oxidizing gas G1, and is provided between the oxidizing gas flow path 20 and the cylindrical member 10. The reforming section 40 is connected to the vaporizing section 30, and is provided with a reforming catalyst layer 42 for generating a reformed gas G4 from a raw fuel gas obtained by vaporizing the raw fuel G2 in the vaporizing section 30. ing.

  The storage section 50 is a cylindrical member provided downstream of the reforming section 40 along the flow direction of the oxidizing gas G1 and having a closed lower end. The housing section 50 houses the fuel cell stack 52 inside. The fuel cell stack 52 is connected to the oxidizing gas channel 20 and to the reforming section 40 via the reforming gas pipe 44. The fuel cell stack 52 generates power by an electrochemical reaction between the oxidizing gas G1 supplied from the oxidizing gas flow path 20 and the reformed gas G4 supplied from the reforming section 40 via the reformed gas pipe 44. At the same time, heat is generated with this power generation. As an example, a solid oxide fuel cell (SOFC) is applied to the fuel cell stack 52 according to the present embodiment.

  The combustion section 70 is provided between the tubular member 10 and the fuel cell stack 52. The combustion unit 70 is in communication with the flue gas flow channel 60, burns the stack exhaust gas discharged from the fuel cell stack 52 to generate a flue gas G 3, and transfers the generated flue gas G 3 to the flue gas flow channel 60. Send out. Note that an ignition electrode 72 is disposed at the center of the combustion section 70. The ignition electrode 72 is provided above the fuel cell stack 52 and separated from the fuel cell stack 52. A pipe 74 is housed inside the tubular member 10, and a conductive part 76 connected to the ignition electrode 72 and insulated by an insulator is inserted inside the pipe 74. That is, the stack exhaust gas discharged from the fuel cell stack 52 is burned by the spark formed between the ignition electrode 72 and the pipe 74, and the combustion exhaust gas G3 is generated.

  The combustion exhaust gas channel 60 is provided between the tubular member 10 and the vaporizing unit 30 and between the tubular member 10 and the reforming unit 40, and is provided to extend to the upper end of the tubular member 10. I have. At the upper end of the flue gas passage 60, a flue gas discharge pipe 80 extending radially outward of the tubular member 10 is provided. The combustion exhaust gas G3 obtained by burning the stack exhaust gas by the combustion unit 70 flows upward in the combustion exhaust gas channel 60, and is discharged to the outside from the combustion exhaust gas discharge pipe 80. At this time, in the vaporization section 30, the raw fuel G2 is vaporized using the heat of the combustion exhaust gas G3. In the reforming section 40, the reforming catalyst layer 42 is heated by using the heat of the combustion exhaust gas G3, and the reforming reaction is promoted.

  The heat insulating material 78 is formed of a member having at least one of heat insulating properties and heat shielding properties, and covers the outside of the above-described module main body. Outside the heat insulating material 78, valves V connected to each of the plurality of oxidizing gas supply pipes 90 are arranged. As the plurality of valves V, for example, a two-way valve whose opening can be adjusted is used. The plurality of valves V according to the present embodiment include a first valve V1, a plurality (three in this embodiment) of second valves V2A to V2C, and a third valve V3. The first valve V1 is connected to the oxidant gas first supply pipe 91. Each of the plurality of second valves V2A to V2C is connected to each of the oxidant gas second supply pipes 92A to 92C. The third valve V3 is connected to the oxidant gas third supply pipe 93.

  In the present embodiment, the first oxidant gas supply pipe 91 is provided at a position corresponding to the upper stage (upstream end in the flow direction) of the vaporization unit 30. The oxidant gas second supply pipe 92 </ b> A is provided at a position corresponding to the middle stage of the vaporization unit 30. The oxidant gas second supply pipe 92B is provided at a position corresponding to the upper stage of the reforming section 40. The oxidizing gas second supply pipe 92C is provided at a position corresponding to the middle stage of the reforming section 40. The third oxidant gas supply pipe 93 is provided at a position corresponding to the upper stage (upstream end in the flow direction) of the fuel cell stack 52. The number of oxidant gas second supply pipes 92A to 92C is not limited to a plurality, and only one of them may be used.

  Further, the configuration may be such that the third oxidant gas supply pipe 93 is not provided. For example, when the oxidizing gas third supply pipe 93 is not provided and only the oxidizing gas first supply pipe 91 and the oxidizing gas second supply pipe 92A are used, the valve V is connected to the above-described two-way. Instead of a valve type, a three-way valve type valve whose opening degree can be finely adjusted may be used.

  According to the module structure shown in FIGS. 1 to 3, at least the vaporizing section 30, the reforming section 40, and the fuel cell stack 52 are arranged coaxially in the vertical direction. With this arrangement, the spread in the width direction is suppressed, and the size can be reduced in the width direction.

  Next, an electrical configuration of the fuel cell module 100 according to the present embodiment will be described with reference to FIG.

FIG. 4 is a block diagram illustrating an example of an electrical configuration of the fuel cell module 100 according to the present embodiment.
As shown in FIG. 4, the fuel cell module 100 according to the present embodiment includes a main structure 110 and a control device 112. The main structure section 110 includes the above-described vaporization section 30, reforming section 40, fuel cell stack 52, combustion section 70, and the like. The combustion section 70, the fuel cell stack 52, and the reforming section 40 are also called high-temperature sections (hot boxes) 58 because they have particularly high temperatures.

  The control device 112 mainly includes a microcomputer 114 including a CPU (Central Processing Unit) 114A, a RAM (Random Access Memory) 114B, and a ROM (Read Only Memory) 114C, obtains information from each unit to be controlled, and controls each unit. Control behavior. Further, the control device 112 includes a storage unit 116. As the storage unit 116, for example, a nonvolatile memory such as an SSD (Solid State Drive) and a flash memory is used.

  The control device 112 is connected to each part of the main structural unit 110 via the signal line S, controls the drive of the blower B1 that supplies methane to the vaporizing unit 30, and supplies the reforming water to the vaporizing unit 30. Of the blower B2 that supplies the oxidizing gas to the fuel cell stack 52 is controlled.

  The raw fuel supply pipe 82 is connected to the vaporization section 30 as described above. The raw fuel supply pipe 82 is provided with an inner supply pipe 82A and an outer supply pipe 82B.

  A hydrocarbon-based fuel source (not shown) is connected to the outer supply pipe 82B, and methane as an example of the hydrocarbon-based fuel flows through the blower B1. On the other hand, a water source (not shown) is connected to the inner supply pipe 82A, and reforming water (liquid phase) flows in by the pump P. Methane and water are introduced into the raw fuel supply pipe 82 so as to flow in parallel (in the same direction). The raw fuel G2 containing methane and water is supplied to the vaporization unit 30 via the raw fuel supply pipe 82. In the vaporizing section 30, the water is vaporized into steam, and a raw fuel gas containing methane and steam is generated. The heat of the combustion exhaust gas G3 discharged from the combustion unit 70 is used for this vaporization.

  In the present embodiment, methane is used as the hydrocarbon-based fuel, but is not particularly limited as long as it is a gas that can be reformed, and other hydrocarbon-based fuels can be used. Examples of other hydrocarbon fuels include natural gas, LP gas (liquefied petroleum gas), coal reformed gas, and lower hydrocarbon gas. Examples of the lower hydrocarbon gas include lower hydrocarbons having 4 or less carbon atoms, such as methane, ethane, ethylene, propane, and butane. Methane used in the present embodiment is preferable. Note that the hydrocarbon-based fuel may be a mixture of the above-mentioned lower hydrocarbon gas.

  The raw fuel gas containing methane and water vapor is sent from the vaporizer 30 to the reformer 40. In the reforming unit 40, methane is steam-reformed, and a reformed gas G4 containing hydrogen and having a temperature of about 600 ° C. is generated. One end of a reformed gas pipe 44 is connected to the reforming section 40. The other end of the reformed gas pipe 44 is connected to an anode (fuel electrode) 52A of the fuel cell stack 52. The reformed gas G4 generated in the reforming section 40 is supplied to the anode 52A via the reformed gas pipe 44.

  The fuel cell stack 52 according to the present embodiment is a solid oxide cell stack, and has a plurality of stacked fuel cells. The operating temperature of the fuel cell stack 52 is, for example, not less than 600 ° C. and not more than 700 ° C., and here, for example, is set to about 650 ° C.

  Each fuel cell of the fuel cell stack 52 has an electrolyte membrane, and an anode (fuel electrode) 52A and a cathode (air electrode) 52B that are respectively laminated on the front and back surfaces of the electrolyte membrane.

  One end of the oxidizing gas passage 20 is connected to the cathode 52B of the fuel cell stack 52, and a blower B2 is connected to the other end of the oxidizing gas passage 20 via a plurality of oxidizing gas supply pipes 90. Have been. The oxidizing gas G1 sent from the blower B2 is supplied to the cathode 52B via at least one of the plurality of oxidizing gas supply pipes 90 and the oxidizing gas flow path 20.

  At the cathode 52B, as shown in the following equation (1), oxygen in the air reacts with the electrons to generate oxygen ions. The generated oxygen ions reach the anode 52A of the fuel cell stack 52 through the electrolyte membrane.

(Air cathode reaction)
1 / 2O ₂ + 2e ⁻ → O ² -... (1)

  Cathode off-gas G6 is discharged from cathode 52B.

  On the other hand, at the anode 52A of the fuel cell stack 52, as shown in the following equations (2) and (3), oxygen ions having passed through the electrolyte membrane react with hydrogen and carbon monoxide in the reformed gas, Water (steam) and carbon dioxide and electrons are generated. The electrons generated at the anode 52A move from the anode 52A to the cathode 52B through an external circuit (not shown), thereby generating power in each fuel cell. Each fuel cell generates heat during power generation.

(Fuel electrode reaction)
^{_{H 2 + O 2- → H 2}} O + 2e - ··· (2)
_{^{CO + O 2- → CO 2 +}} 2e - ··· (3)

  One end of an anode off-gas pipe 54A is connected to the anode 52A. The anode off gas G5 is discharged from the anode 52A to the anode off gas pipe 54A. The anode off-gas G5 contains unreacted hydrogen, unreacted carbon monoxide, carbon dioxide, water vapor, and the like. The other end of the anode off-gas pipe 54A is connected to the combustion unit 70, and the anode off-gas G5 is sent to the combustion unit 70.

  On the other hand, one end of a cathode off-gas pipe 54B is connected to the cathode 52B. The other end of the cathode offgas pipe 54B is connected to the combustion unit 70, and the cathode offgas G6 is delivered to the combustion unit 70.

  In the combustion section 70, the anode off-gas G5 discharged from the anode 52A of the fuel cell stack 52 is burned. One end of the flue gas passage 60 is connected to the outlet side of the combustion section 70. The flue gas G3 flowing upward in the flue gas flow path 60 undergoes heat exchange with each of the vaporization unit 30 and the reforming unit 40, and then is externally discharged through a flue gas discharge pipe 80 (see FIG. 1). Is discharged.

  Next, the operation of the fuel cell module 100 according to the present embodiment at the time of startup will be described.

When starting the fuel cell module 100 according to the present embodiment, the inside of the module is heated by the combustion of the hydrocarbon-based fuel and the oxidizing gas G1, and the temperature of the fuel cell stack 52 is increased. Then, as described above, when the temperature of the fuel cell stack 52 exceeds a certain temperature (temperature T _CS ), reforming water is supplied to the reforming section 40 via the vaporizing section 30. ing.

  Next, the operation of the fuel cell module 100 of the present embodiment during power generation will be described.

  When the fuel cell module 100 according to the present embodiment generates power, the oxidizing gas G1 sent out by the blower B2 at a predetermined air discharge rate is supplied to the cathode 52B through the oxidizing gas flow path 20 and used for power generation. After that, it is sent to the combustion section 70 via the cathode offgas pipe 54B. On the other hand, the methane delivered at a predetermined discharge amount by the blower B1 is supplied to the vaporization unit 30 via the outer supply pipe 82B of the raw fuel supply pipe 82. Further, the water (liquid phase) delivered at a predetermined discharge amount by the pump P is supplied to the vaporization section 30 via the inner supply pipe 82A of the raw fuel supply pipe 82. The water and methane supplied to the vaporization section 30 are heated by heat exchange with the combustion exhaust gas G3. Thereby, the water is vaporized into steam, and the heated methane and steam are sent to the reforming section 40. Then, the gas is reformed into the reformed gas G4 in the reforming section 40, supplied to the anode 52A, and used for power generation. From the anode 52A, an anode off-gas G5 containing a fuel such as unreacted hydrogen is discharged, and sent out to the combustion unit 70 via an anode off-gas pipe 54A. Further, the cathode offgas G6 is sent out to the combustion unit 70 via the cathode offgas pipe 54B. In the combustion section 70, the anode off-gas G5 discharged from the anode 52A is burned to be a combustion exhaust gas G3, and the combustion exhaust gas G3 flows upward in the combustion exhaust gas channel 60. The flue gas G3 flowing upward in the flue gas flow path 60 is discharged to the outside via the flue gas discharge pipe 80 after heat exchange is performed between each of the vaporizing section 30 and the reforming section 40.

  By the way, as described above, it is desirable that the temperature of the reforming unit 40 can be individually controlled when the fuel cell is started or when power is generated.

  Therefore, a temperature control processing program for executing the temperature control processing according to the present embodiment is stored in the ROM 114C included in the control device 112 in advance. This temperature control processing program may be installed in the control device 112 in advance, for example. The temperature control processing program may be realized by being stored in a non-volatile storage medium or distributed via a network and appropriately installed in the control device 112. Examples of the non-volatile storage medium include CD-ROM (Compact Disc Read Only Memory), magneto-optical disk, HDD (Hard Disk Drive), DVD-ROM (Digital Versatile Disc Read Only Memory), flash memory, and memory. Cards and the like.

  The CPU 114A functions as the control unit according to the present embodiment by writing out the temperature control processing program stored in the ROM 114C to the RAM 114B and executing the program.

  The CPU 114A according to the present embodiment adjusts the amount of the oxidizing gas distributed to each of the plurality of oxidizing gas supply pipes 90 at least at the time of starting the fuel cell stack 52 and at the time of power generation, thereby performing reforming. The temperature of the unit 40 is controlled. Specifically, the CPU 114A feedback-controls the opening degree of each of the plurality of valves V while monitoring each of the temperature of the reforming unit 40 and the temperature of the fuel cell stack 52.

  As shown in FIG. 4, a reforming unit temperature sensor 46 that detects the temperature inside the reforming unit 40 is attached to the reforming unit 40. The temperature information detected by the reforming unit temperature sensor 46 is sent to the control device 112.

  A cell stack temperature sensor 56 for detecting the temperature inside the fuel cell stack 52 is attached to the fuel cell stack 52. The temperature information detected by the cell stack temperature sensor 56 is sent to the control device 112.

  The CPU 114A of the control device 112 feedback-controls the opening degree of each of the plurality of valves V based on the temperature information of the reforming section 40 and the temperature information of the fuel cell stack 52, to thereby control the plurality of oxidizing gas supply pipes 90. The amount of the oxidizing gas to be distributed to each of the above is adjusted.

Here, the storage unit 116 of the control device 112 stores the first temperature T _ref1 , which is the lower limit temperature at which carbon precipitation starts inside the reforming unit 40, and the condensation of water vapor inside the fuel cell stack 52. a second temperature T _CS is the temperature of the generated upper limit, it is stored. The first temperature T _ref1 is, for example, in a range from 350 ° C. to 450 ° C., for example, 400 ° C. In this case, it means that carbon deposition occurs at 400 ° C. or higher. The second temperature _TCS is, for example, in a range of 90 ° C. or more and 110 ° C. or less, for example, 100 ° C. In this case, it means that condensation of water vapor occurs at 100 ° C. or less. The storage unit 116 also stores a third temperature T _ref3 , which is a temperature at which the reforming catalyst layer 42 is damaged, and a temperature at which the reforming ratio in the reforming unit 40 is equal to or higher than a reference value (for example, 80%). The fourth temperature T _ref4 is stored.

When the temperature of the reforming unit 40 rises to a predetermined threshold temperature T _ref2 lower than the first temperature T _ref1 when the fuel cell stack 52 is activated, the CPU 114A according to the present embodiment The opening degree of V2A is controlled to increase the amount of the oxidizing gas distributed to the oxidizing gas second supply pipe 92A, and the opening degree of the first valve V1 is controlled to connect the oxidizing gas first supply pipe 91 to the oxidizing gas first supply pipe 91. Reduce the amount of oxidant gas to be distributed. In this case, the second valves V2B and V2C and the third valve V3 are set to “fully closed”. As the threshold temperature T _ref2 , for example, (T _ref1 −A) ° C., which is a temperature slightly lower than the first temperature T _ref1, is used. This constant value A is stored in the storage unit 116 in advance, and is a value that can be appropriately changed as needed. Here, it is assumed that “A = 30” or the like as an example. By controlling the opening of each of the second valve V2A and the first valve V1, the distribution amount of the oxidizing gas between the oxidizing gas second supply pipe 92A and the oxidizing gas first supply pipe 91 is controlled. adjusting the temperature of the fuel cell stack 52 to greater than the second temperature _{T CS,} to control the temperature of the reforming section 40 below the first temperature _{T ref1.}

Further, CPU 114A, in the case where the temperature of the fuel cell stack 52 is equal to or lower than the second temperature T _CS, vaporization controls the drive of each of the blowers B1 and pump P, and the raw fuel G2 water free reforming To the unit 30. Meanwhile, CPU 114A, in the case where the temperature of the fuel cell stack 52 exceeds the second temperature T _CS, and controls the drive of each of the blowers B1 and a pump P, vaporizing portion raw fuel G2 containing water reforming The control for supplying to 30 is performed.

Further, CPU 114A has, at the time of startup of the fuel cell stack 52, when the temperature of the reforming section 40 rises to the threshold temperature _{T ref2,} by controlling the degree of opening of the second valve V2A, oxidant gas second supply When the entire amount of the oxidizing gas is distributed to the pipe 92A, and thereafter the temperature of the reforming section 40 continues to rise, the opening degree of the second valve V2B is further controlled to control the oxidizing gas second supply pipe 92B. The distribution of the oxidizing gas to the second oxidizing gas supply pipe 92A may be reduced by controlling the opening of the second valve V2A. In this case, the first valve V1, the second valve V2C, and the third valve V3 are set to “fully closed”. By controlling the opening of each of the second valve V2A and the second valve V2B, the amount of distribution of the oxidizing gas between the oxidizing gas second supply pipe 92A and the oxidizing gas second supply pipe 92B is controlled. adjusting the temperature of the fuel cell stack 52 to greater than the second temperature _{T CS,} to control the temperature of the reforming section 40 below the first temperature _{T ref1.}

On the other hand, the CPU 114A opens the second valve V2A when the temperature of the reforming unit 40 rises to a predetermined threshold temperature _Tref5 lower than the third temperature _Tref3 during power generation of the fuel cell stack 52. The amount of the oxidizing gas distributed to the second oxidizing gas supply pipe 92A is increased by controlling the degree of oxidation, and the opening degree of the first valve V1 is controlled to control the degree of oxidation distributed to the first oxidizing gas supply pipe 91. Reduce the amount of agent gas. In this case, the second valves V2B and V2C and the third valve V3 are set to “fully closed”. As the threshold temperature T _ref5 , for example, (T _ref3 −B) ° C., which is slightly lower than the third temperature T _ref3, is used. This constant value B is stored in the storage unit 116 in advance, and is a value that can be appropriately changed as needed, like the above-described constant value A. Here, it is assumed that “B = 30” or the like as an example. By controlling the opening of each of the second valve V2A and the first valve V1, the distribution amount of the oxidizing gas between the oxidizing gas second supply pipe 92A and the oxidizing gas first supply pipe 91 is controlled. The temperature of the reforming section 40 is adjusted to be _lower than the third temperature _Tref3 .

In addition, when the temperature of the reforming unit 40 does not increase to the fourth temperature _Tref4 during the power generation of the fuel cell stack 52, the _{CPU 114A} controls the opening of the third valve V3 to control the oxidant gas third. By increasing the amount of the oxidizing gas distributed to the supply pipe 93 and controlling the opening of at least one of the first valve V1 and the second valve V2A, the first oxidizing gas supply pipe 91 and the second oxidizing gas supply The amount of the oxidizing gas distributed to at least one of the tubes 92A may be reduced. In this case, the second valves V2B and V2C are set to “fully closed”. By controlling the opening of each of the third valve V3, the first valve V1, and the second valve V2A, the oxidizing gas third supply pipe 93, the oxidizing gas first supply pipe 91, and the oxidizing gas The distribution amount of the oxidizing gas is adjusted between the second supply pipes 92A, and the temperature of the reforming section 40 is controlled to be _{equal to} or higher than the fourth temperature _Tref4 .

  Next, this is obtained when the distribution amount of the oxidizing gas G1 is controlled using the oxidizing gas first supply pipe 91, the plurality of oxidizing gas second supply pipes 92A to 92C, and the oxidizing gas third supply pipe 93. The effect obtained is described.

(A) The oxidizing gas G1 is supplied from the oxidizing gas second supply pipe 92A provided in the middle stage of the vaporizing section 30: At the time of startup, the temperature of the reforming section 40 is reduced, and the risk of carbon deposition is reduced. Is obtained. In addition, at the time of power generation, an effect of avoiding damage to the reforming catalyst due to excessive heating of the reforming section 40 (such as deflowering due to thermal stress) can be obtained. As a secondary effect, an effect of lowering the temperature of the vaporizing section 30 at the time of startup and improving the vaporization stability of the reforming water can be obtained.

(B) Supplying the oxidizing gas G1 from the oxidizing gas second supply pipe 92B provided at the upper stage of the reforming unit 40 or the oxidizing gas second supply tube 92C provided at the middle stage of the reforming unit 40: Start At times, similarly to the above (A), the effect of lowering the temperature of the reforming section 40 and reducing the risk of carbon deposition can be obtained. Further, at the time of power generation, the effect of reducing the risk of breakage of the reforming catalyst can be obtained as in the case of (A).

(C) Supplying the oxidizing gas G1 from the third oxidizing gas supply pipe 93 provided in the upper stage of the fuel cell stack 52: when the temperature of the reforming section 40 does not rise and the reforming is not sufficiently performed. By distributing a part of the oxidizing gas G1 to the third oxidizing gas supply pipe 93, the flow rate of the oxidizing gas G1 passing outside the reforming section 40 is reduced, and the temperature of the reforming section 40 is increased. The effect is obtained. On the other hand, at the time of power generation, the effect of suppressing an increase in the internal temperature of the cell stack due to heat generation of the fuel cell stack 52 and reducing the risk of breakage due to excessive temperature rise of the cell stack is obtained. In addition, since the amount of heat recovered from the cell stack having the highest temperature increases, the thermal efficiency of the entire hot box is improved, which contributes to the improvement of the efficiency.

  Next, with reference to FIG. 5 and FIG. 6, an operation at the time of starting the fuel cell module 100 according to the present embodiment will be described. FIG. 5 is a flowchart illustrating an example of the flow of processing by the temperature control processing program when the fuel cell module 100 according to the present embodiment is started. FIG. 6 is a timing chart of the startup operation control executed when the fuel cell module 100 according to the present embodiment is started.

  First, when the power supply of the fuel cell module 100 is turned on, the temperature control processing program stored in the ROM 114C is executed by the CPU 114A, and the following steps are executed.

In step 200 of FIG. 5, the CPU 114A sets a threshold temperature T _ref2 obtained by subtracting the constant value A from the first temperature T _ref1 . As described above, the first temperature T _ref1 is a temperature at which carbon deposition starts inside the reforming section 40, and it is important to control the temperature not to be higher than the first temperature T _ref1 during the start-up operation. It is. Therefore, as shown at the top of FIG. 6, to set the threshold temperature _{T ref2} obtained by subtracting a predetermined value A from the first temperature _{T ref1,} the threshold temperature _{T ref2} as an upper limit, the internal temperature of the reformer 40 to monitor the T _K.

  In step 202, the CPU 114A controls the first valve V1 to "fully open" and controls the second valves V2A to V2C and all the third valves V3 to "fully closed", as shown in the third row from the top in FIG. Then, the supply of the oxidizing gas G1 from the first oxidizing gas supply pipe 91 at a constant flow rate is started.

  In step 204, the CPU 114A controls the drive of the blower B1 to start supplying a hydrocarbon-based fuel (here, methane) at a constant flow rate as shown in the second stage from the bottom in FIG.

  The constant flow rate of the oxidizing gas G1 is set to be equal to or less than the maximum flow rate at which the flame is not completely misfired and the combustion can be maintained when burning in the combustion section 70. The constant flow rate of the hydrocarbon-based fuel is not less than the minimum flow rate at which the flame does not completely misfire and the combustion can be maintained when the fuel is burned in the combustion section 70.

  In step 206, the CPU 114A controls the combustion in the combustion section 70. In the combustion section 70, combustion is performed in a constant combustion state by the supplied oxidizing gas G1 at a constant flow rate and the hydrocarbon-based fuel at a constant flow rate.

In step 208, the CPU 114 </ b> A detects the internal temperature T _S of the fuel cell stack 52 with the cell stack temperature sensor 56.

In step 210, as shown in the second row from the top in FIG. 6, the CPU 114A changes the internal temperature T _{S of} the fuel cell stack 52 detected in step 208 to the condensation of water vapor inside the fuel cell stack 52 described above. it is equal to or is a second temperature T _CS than is the upper limit temperature that occur. When it is determined that the internal temperature T _S is equal to or higher than the second temperature T _CS (in the case of a positive determination), the process proceeds to step 212. On the other hand, when it is determined that the internal temperature T _S is _lower than the second temperature T _CS (in the case of a negative determination), the process proceeds to step 216.

  In step 212, the CPU 114A determines that the start-up process has been completed, and controls the drive of the pump P to start supplying reformed water at a constant flow rate as shown in the lowermost part of FIG.

In step 214, the CPU 114A instructs the transition to the normal operation, and ends a series of processing by the temperature control processing program at the time of startup. By the shift to the normal operation, reforming is performed in the reforming unit 40, and power generation is started in the fuel cell stack 52. At this time, as shown in the second stage from the bottom of FIG. 6, as the internal temperature T _K of the reforming section 40 is constant, the supply flow rate of the hydrocarbon-based fuel is controlled. As shown in the third and fourth stages from the top in FIG. 6, as an example, the oxidizing gas G1 is distributed between the oxidizing gas first supply tube 91 and the oxidizing gas second supply tube 92A. In this case, control is performed so that the entire amount of the oxidizing gas G1 is distributed to the first oxidizing gas supply pipe 91.

On the other hand, in step 216, CPU 114A detects the internal temperature _{T K} of the reformer 40 by the reforming section temperature sensor 46.

In step 218, the CPU 114A determines whether or not the internal temperature T _K of the reforming unit 40 detected in step 216 is equal to or higher than the above-described threshold temperature T _ref2 , as shown in the uppermost part of FIG. When the internal temperature _{T K} is determined to be the threshold temperature _{T ref2} or (in the case of affirmative determination), the process proceeds to step 220. On the other hand, (in the case of negative determination) When the internal temperature _{T K} is determined to be less than the threshold temperature _{T ref2,} repeat the process returns to step 208.

In step 220, the CPU 114A performs control to adjust the amount of the oxidizing gas G1 distributed to each of the plurality of oxidizing gas supply pipes 90. Here, in order to simplify the explanation, the distribution amount of the oxidizing gas G1 is adjusted between the oxidizing gas first supply pipe 91 and the oxidizing gas second supply pipe 92A. Specifically, as shown in the third row from the top in FIG. 6, the opening degree of the first valve V1 is reduced, and the distribution amount of the oxidizing gas G1 to the oxidizing gas first supply pipe 91 is reduced. As shown in the fourth row from the top in FIG. 6, the opening of the second valve V2A is increased, and the amount of distribution of the oxidizing gas G1 to the oxidizing gas second supply pipe 92A is increased. Incidentally, as shown at the top of FIG. 6, when the internal temperature T _K is the threshold temperature T _ref2 above again, the first valve V1 is "fully closed", controls the second valve V2A to "fully open" I do.

That is, when the temperature of the reforming unit 40 is controlled to be lower than the first temperature T _ref1 , when the internal temperature of the reforming unit 40 becomes equal to or higher than the threshold temperature T _ref2 , another oxidizing gas supply pipe is used until the temperature falls below the threshold temperature T _ref2. The distribution amount of the oxidizing gas G1 to 90 is increased. For example, distribution is preferentially performed from the oxidizing gas supply pipe 90 located at the upper stage, and if the temperature rise does not stop even when the entire amount is distributed, distribution to the oxidizing gas supply tube 90 located at the lower stage is started. . However, it is not necessary to add all four oxidizing gas supply pipes 90, and three or less may be added.

  In addition, for the flow rate control of the oxidizing gas G1, for example, control using feedback of the inlet temperature of the reforming unit 40 may be performed. If the temperature of the inlet of the reforming unit 40 drops to 100 ° C. or lower, if water is supplied to the vaporizing unit 30, dew condensation may occur. For this reason, an appropriate threshold temperature (for example, about 130 ° C.) is set, and when the inlet temperature of the reforming section 40 decreases to the threshold temperature, the distribution of the oxidizing gas G1 is stopped or as it approaches. Control for reducing the distribution amount of the oxidizing gas G1 may be performed. In this case, PID (Proportional-Integral-Differential) or the like may be used for feedback control in order to enhance stability.

  Next, the operation of the fuel cell module 100 according to the present embodiment at the time of power generation will be described with reference to FIGS. FIG. 7 is a flowchart illustrating an example of the flow of processing by the temperature control processing program when the fuel cell module 100 according to the present embodiment generates power. FIG. 7 illustrates a mode of avoiding damage to the reforming catalyst due to excessive temperature rise of the reforming section 40. At the time of this power generation, the first valve V1 is "fully opened", and the second valves V2A to V2C and the third valve V3 are all "fully closed".

First, in step 230 of FIG. 7, the CPU _114A sets a threshold temperature _Tref5 obtained by subtracting a constant value B from the third temperature _Tref3 . As described above, the third temperature T _ref3 is a temperature at which the reforming catalyst layer 42 of the reforming section 40 is damaged, and it is important to control the temperature not to be higher than the third temperature T _ref3 during the power generation operation. It is. Therefore, set the threshold temperature _{T REF5} obtained by subtracting a predetermined value B from the third temperature _{T ref3,} the threshold temperature _{T REF5} as the upper limit, monitoring the internal temperature _{T K} of the reformer 40.

In step 232, CPU 114A detects the internal temperature _{T K} of the reformer 40 by the reforming section temperature sensor 46.

In step 234, CPU 114A has an internal temperature _{T K} of the reformer 40 detected in step 232, it is determined whether the threshold temperature _{T REF5} than described above. When the internal temperature _{T K} is determined to be the threshold temperature _{T REF5} more (if affirmative judgment), the process proceeds to step 236. On the other hand, (in the case of negative determination) When the internal temperature _{T K} is determined to be less than the threshold temperature _{T REF5,} the process proceeds to step 238.

  In step 236, the CPU 114A performs control to adjust the amount of the oxidizing gas G1 distributed to each of the plurality of oxidizing gas supply pipes 90, and proceeds to step 232. Here, in order to simplify the explanation, the distribution amount of the oxidizing gas G1 is adjusted between the oxidizing gas first supply pipe 91 and the oxidizing gas second supply pipe 92A. Specifically, the opening degree of the first valve V1 is reduced, the amount of distribution of the oxidizing gas G1 to the oxidizing gas first supply pipe 91 is reduced, and the opening degree of the second valve V2A is increased. The distribution amount of the oxidizing gas G1 to the second gas supply pipe 92A is increased.

  In step 238, the CPU 114A determines whether to terminate the power generation operation. For example, when an operation input for instructing the end of the power generation operation is received from the worker, it is determined to end the power generation operation. When it is determined that the power generation operation is to be ended (in the case of a positive determination), a series of processes by the temperature control processing program at the time of power generation is ended. On the other hand, when it is determined that the power generation operation is not to be ended (in the case of a negative determination), the process returns to step 232 to repeat the processing.

  FIG. 8 is a flowchart illustrating another example of the flow of the processing by the temperature control processing program when the fuel cell module 100 according to the present embodiment generates power. FIG. 8 illustrates an embodiment in which the temperature of the reforming unit 40 is increased when the temperature of the reforming unit 40 does not rise and the reforming is not sufficiently performed.

At step 240 in FIG. 8, the CPU _114A sets the fourth temperature _Tref4 . As described above, the fourth temperature T _ref4 is a temperature at which the reforming ratio in the reforming section 40 is equal to or higher than the reference value (for example, 80%). During the power generation operation, the fourth temperature T _{ref4 is equal to} or higher than the fourth temperature T _ref4 . It is important to control. Therefore, the lower limit of the fourth temperature _{T ref4,} to monitor the internal temperature _{T K} of the reformer 40.

In step 242, CPU 114A detects the internal temperature _{T K} of the reformer 40 by the reforming section temperature sensor 46.

In step 244, CPU 114A has an internal temperature _{T K} of the reformer 40 detected in step 242, determines whether the fourth lower than the temperature _{T ref4} described above. When the internal temperature _{T K} is determined to be less than the fourth temperature _{T ref4} (the case of affirmative determination), the process proceeds to step 246. On the other hand, (in the case of negative determination) When the internal temperature _{T K} is determined to be the fourth temperature _{T ref4} or more, the process proceeds to step 248.

  In step 246, the CPU 114A performs control to adjust the amount of the oxidizing gas G1 distributed to each of the plurality of oxidizing gas supply pipes 90, and proceeds to step 242. Here, in order to simplify the explanation, the distribution amount of the oxidizing gas G1 between the first oxidizing gas supply pipe 91 and the third oxidizing gas supply pipe 93 is adjusted. Specifically, the opening degree of the first valve V1 is reduced, the distribution amount of the oxidizing gas G1 to the oxidizing gas second supply pipe 92A is reduced, and the opening degree of the third valve V3 is increased. The distribution amount of the oxidizing gas G1 to the third gas supply pipe 93 is increased.

  At step 248, CPU 114A determines whether or not to terminate the power generation operation. For example, when an operation input for instructing the end of the power generation operation is received from the worker, it is determined to end the power generation operation. When it is determined that the power generation operation is to be ended (in the case of a positive determination), a series of processes by the temperature control processing program at the time of power generation is ended. On the other hand, when it is determined that the power generation operation is not to be ended (in the case of a negative determination), the process returns to step 242 to repeat the processing.

  The outlet temperature of the reforming section 40 is controlled to be equal to or higher than a predetermined temperature by utilizing the effect of raising the temperature of the reforming section 40 by partially distributing the oxidizing gas G1 to the oxidizing gas supply pipe 90 at the lowermost stage. May be performed. For example, control is performed using feedback of the outlet temperature of the reforming section 40. Specifically, an appropriate threshold temperature (for example, about 700 ° C.) is set, and when the outlet temperature of the reforming unit 40 rises to the threshold temperature, the oxidizing gas G1 to the oxidizing gas supply pipe 90 at the lowermost stage is set. Is controlled, or the distribution amount of the oxidizing gas G1 is increased as it approaches. In this case, PID may be used for feedback control in order to enhance stability.

  Although the fuel cell module has been described as an example in each of the above embodiments, the embodiment may be in the form of a program for causing a computer to execute the functions of each unit included in the fuel cell module. The embodiment may be in the form of a computer-readable storage medium storing the program.

  In addition, the configuration of each of the fuel cell modules described in each of the above embodiments is merely an example, and may be changed according to circumstances without departing from the gist of the invention.

  The processing flow of the program described in each of the above embodiments is also an example, and unnecessary steps may be deleted, new steps may be added, or the processing order may be changed without departing from the scope of the present invention. Is also good.

  Further, in each of the above-described embodiments, a case has been described in which the processing according to the embodiment is realized by a software configuration using a computer by executing a program, but is not limited thereto. The embodiment may be realized by, for example, a hardware configuration or a combination of a hardware configuration and a software configuration.

Reference Signs List 10 cylindrical member 12 outer peripheral wall 14 adiabatic space 20 oxidant gas flow path 30 vaporizer 40 reformer 42 reforming catalyst layer 44 reformed gas pipe 46 reformer temperature sensor 50 housing 52 fuel cell cell stack 52A anode ( Fuel electrode)
52B cathode (air electrode)
54A Anode off gas pipe 54B Cathode off gas pipe 56 Cell stack temperature sensor 58 High temperature section (hot box)
Reference Signs List 60 combustion exhaust gas passage 70 combustion part 72 ignition electrode 74 pipe 76 conductive part 78 heat insulating material 80 combustion exhaust gas discharge pipe 82 raw fuel supply pipes 90, 91, 92A to 92C, 93 oxidizing gas supply pipe 100 fuel cell module 110 main structure Unit 112 Control unit 114 Microcomputer 114A CPU (control unit)
114B RAM
114C ROM
116 Memory

Claims (14)

A cylindrical member in which a heat insulating space is formed by a cylindrical outer peripheral wall,
An oxidizing gas channel surrounding the outer peripheral wall and provided coaxially with the outer peripheral wall, and through which an oxidizing gas flows;
A vaporization unit provided between the oxidant gas flow path and the tubular member, and vaporizes a raw fuel to generate a raw fuel gas,
A reformed gas is provided on the downstream side of the vaporization section along the flow direction of the oxidizing gas and between the oxidizing gas flow path and the cylindrical member, and generates a reformed gas from the raw fuel gas. A reforming section provided with a reforming catalyst layer for
A tubular storage unit that is provided downstream of the reforming unit along the flow direction, and that stores a fuel cell stack that generates power by an electrochemical reaction between the oxidizing gas and the reformed gas,
A plurality of oxidizing gas supply pipes provided along the flow direction of the oxidizing gas flow path,
A control for controlling the temperature of the reforming unit by adjusting the amount of the oxidizing gas distributed to each of the plurality of oxidizing gas supply pipes at least at the time of starting the fuel cell stack and at the time of power generation. Department and
A fuel cell module comprising: The plurality of oxidizing gas supply pipes,
An oxidant gas first supply pipe provided at a position corresponding to an upstream end of the vaporization section in the flow direction;
An oxidizing gas second supply pipe provided at a position corresponding to the vaporization section or the reforming section downstream of the oxidizing gas first supply pipe along the flow direction;
The fuel cell module according to claim 1, comprising:   The controller distributes the gas to the oxidant gas second supply pipe when the temperature of the reformer rises to a predetermined threshold temperature lower than the first temperature when the fuel cell stack is started. By increasing the amount of the oxidizing gas to be supplied and decreasing the amount of the oxidizing gas distributed to the first oxidizing gas supply pipe, the second temperature at which the temperature of the fuel cell stack is lower than the threshold temperature is reduced. The fuel cell module according to claim 2, wherein the temperature of the reforming unit is controlled to be lower than the first temperature until the temperature exceeds the first temperature. The first temperature is a temperature at which precipitation of carbon starts in the reforming section,
The fuel cell module according to claim 3, wherein the second temperature is an upper limit temperature at which condensation of water vapor occurs in the fuel cell stack.   The control unit, when the temperature of the fuel cell stack is equal to or lower than the second temperature, supplies the raw fuel containing no water for reforming to the vaporization unit, and the temperature of the fuel cell stack is 5. The fuel cell module according to claim 3, wherein when the temperature exceeds the second temperature, control is further performed to supply the raw fuel containing water for reforming to the vaporization unit. The oxidant gas second supply pipe is plural,
Each of the plurality of oxidant gas second supply pipes is provided at a position downstream of the oxidant gas first supply pipe along the flow direction and corresponding to each of the vaporizing section and the reforming section. The fuel cell module according to claim 2, wherein:   The control unit is provided at a position corresponding to the vaporizing unit when the temperature of the reforming unit rises to a predetermined threshold temperature lower than the first temperature when the fuel cell stack is started. The entire amount of the oxidizing gas is distributed to the oxidizing gas second supply pipe, and when the temperature of the reforming section continues to rise, the oxidizing gas gas provided at a position corresponding to the reforming section is continuously supplied. 2 By starting distribution of the oxidizing gas to the supply pipe, the temperature of the reforming section is reduced to less than the first temperature until the temperature of the fuel cell stack exceeds a second temperature lower than the threshold temperature. The fuel cell module according to claim 6, which is controlled.   The controller distributes the gas to the oxidant gas second supply pipe when the temperature of the reformer rises to a predetermined threshold temperature lower than a third temperature during power generation of the fuel cell stack. 3. The temperature of the reforming section is controlled to be lower than the third temperature by increasing the amount of oxidizing gas to be performed and decreasing the amount of oxidizing gas distributed to the first oxidizing gas supply pipe. The fuel cell module according to item 1.   The fuel cell module according to claim 8, wherein the third temperature is a temperature at which the reforming catalyst layer breaks.   3. The fuel according to claim 2, wherein the plurality of oxidizing gas supply pipes further include an oxidizing gas third supply pipe provided at a position corresponding to an upstream end of the fuel cell stack in the flow direction. 4. Battery module.   The control unit increases the amount of the oxidizing gas distributed to the oxidizing gas third supply pipe when the temperature of the reforming unit does not rise to a fourth temperature during power generation of the fuel cell stack. Controlling the temperature of the reforming section to be equal to or higher than the fourth temperature by reducing an amount of the oxidizing gas distributed to at least one of the oxidizing gas first supply pipe and the oxidant gas second supply pipe. The fuel cell module according to claim 10.   The fuel cell module according to claim 11, wherein the fourth temperature is a temperature at which a reforming ratio in the reforming section is equal to or higher than a reference value. Combustion exhaust gas provided between the tubular member and the vaporizing section and between the tubular member and the reforming section, and obtained by burning stack exhaust gas discharged from the fuel cell stack Further comprising a flue gas flow path through which
The vaporization unit vaporizes the raw fuel using heat of the combustion exhaust gas,
The fuel cell module according to claim 1, wherein the reforming section heats the reforming catalyst layer using heat of the combustion exhaust gas.   A program for causing a computer to function as a control unit included in the fuel cell module according to any one of claims 1 to 13.