Fuel battery device

Abstract

To improve a water collection efficiency while suppressing excessive temperature rise of a fuel battery.SOLUTION: A fuel battery device 10 includes a module 11, a heat medium flow channel 12, a heat generation part 13, and a control device 14. The module 11 includes a fuel battery and an exhaust gas processing part. The fuel battery generates power by using the fuel gas and air. The exhaust gas processing part houses a fuel catalyst for processing an exhaust gas exhausted from the fuel battery. The heat medium flow channel 12 makes circulation of a heat medium for performing heat exchange with the exhaust gas exhausted from the module 11. The heat generation part 13 is provided in the heat medium flow channel 12. The heat generation part 13 includes a fun for discharging heat of the heat medium. The control device 14 increases an air amount to be supplied to the fuel battery in the case where the temperature of the fuel battery is a first temperature or higher or the case where the temperature of the fuel catalyst is a second temperature or higher, and increases the number of rotations of the fun.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a fuel cell device. [Background technology]

[0002] Fuel cells, such as solid oxide fuel cells, need to be kept at a relatively high temperature during power generation. Therefore, the fuel cell is generally covered with insulation and the like together with the reformer, which needs to be kept at a high temperature. The fuel cell is designed to be kept at an appropriate temperature range during rated operation. However, if the fuel cell is operated under conditions different from those assumed for rated operation, the temperature inside the insulation may rise excessively. For example, if the raw fuel supplied to a fuel cell device including the fuel cell is a biogas whose composition varies from the assumed composition, particularly if the concentration of hydrocarbons such as methane is higher than the assumed composition, excessive temperature rise may occur.

[0003] In order to prevent an excessive temperature rise, it has been proposed to increase the flow rate of air and the amount of water supplied to the fuel cell (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2012-216290 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, when the air flow rate is increased, the exhaust gas containing water vapor is discharged to the outside, and the water recovery efficiency decreases.

[0006] In view of the above, an object of the present disclosure is to improve the water recovery efficiency compared to a configuration that does not use the configuration of the present disclosure while suppressing an excessive rise in temperature of a fuel cell. [Means for solving the problem]

[0007] In order to solve the above problems, a fuel cell device according to a first aspect of the present invention comprises: a fuel cell that generates electricity using fuel gas and air, and a module having an exhaust gas treatment device that accommodates a combustion catalyst that treats exhaust gas discharged from the fuel cell; a heat medium flow path for a heat medium that exchanges heat with the exhaust gas discharged from the module; a heat dissipation unit provided in the heat medium flow path and having a fan that dissipates heat from the heat medium; and a control device that increases the amount of air supplied to the fuel cell and increases the rotation speed of the fan when the temperature of the fuel cell is equal to or higher than a first temperature or when the temperature of the combustion catalyst is equal to or higher than a second temperature.

[0008] A fuel cell device according to a second aspect of the present invention comprises: a module having a fuel cell that generates electricity using a fuel gas and air, and a reformer that generates the fuel gas by steam reforming a raw fuel and water; and a control device that increases an amount of water supplied to the reformer when the temperature of the fuel cell is equal to or higher than a first temperature. Effect of the Invention

[0009] According to the present disclosure, the efficiency of water recovery is improved while preventing an excessive rise in temperature of the fuel cell. [Brief description of the drawings]

[0010] [Figure 1] 1 is a diagram showing a schematic configuration of a fuel cell device according to an embodiment of the present invention; [Diagram 2] 2 is a schematic cross-sectional view showing the internal configuration of the module of FIG. 1. [Diagram 3] 4 is a flowchart for explaining a first excessive temperature rise suppression process executed by the control device of FIG. [Figure 4] 4 is a flowchart for explaining a second excessive temperature rise suppression process executed by the control device of FIG. 1; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In the following drawings, the same components are denoted by the same reference numerals.

[0012] 1, a fuel cell device 10 according to an embodiment of the present disclosure includes a module 11, a heat medium flow path 12, a heat dissipation section 13, and a control device 14. The fuel cell device 10 may further include a heat storage tank 15, a heat exchanger 16, a gas-liquid separator 17, a water tank 18, a first temperature sensor 19, and a second temperature sensor 20.

[0013] 2, the module 11 includes a fuel cell 21 and an exhaust gas treatment unit 22. The module 11 may further include a reformer 23, a combustion unit 24, a third temperature sensor 25, a fourth temperature sensor 26, a first adjustment mechanism 27, a second adjustment mechanism 28, and a third adjustment mechanism 29.

[0014] The fuel cell 21 may include a fuel cell. The fuel cell 21 may include a plurality of fuel cells. In the fuel cell 21, the plurality of fuel cells may form a cell stack. The fuel cell may be a solid oxide fuel cell. The fuel cell 21 generates power through an electrochemical reaction using a fuel gas and an oxygen-containing gas such as air. The fuel cell 21 discharges water produced by the power generation, and an exhaust gas containing at least unreacted fuel gas and oxygen-containing gas. The exhaust gas may contain raw fuel gas unreacted in the reformer 23 described below.

[0015] The exhaust gas treatment device 22 may be located in an exhaust path for discharging exhaust gas discharged from the fuel cell 21 from the module 11. The exhaust gas treatment device 22 contains a combustion catalyst. The combustion catalyst treats the exhaust gas. Specifically, the combustion catalyst combusts combustible gas. The combustible gas is, for example, unreacted fuel gas contained in the exhaust gas, or carbon monoxide generated by incomplete combustion of the exhaust gas in a combustion section 24 described below. The exhaust gas is discharged outside the module 11 after passing through the exhaust gas treatment device 22.

[0016] The reformer 23 may generate fuel gas to be supplied to the fuel cell 21 by steam reforming the raw fuel and water. The raw fuel includes light hydrocarbons such as methane, ethane, propane, and butane. The raw fuel is, for example, gas supplied through a gas pipe network, gas supplied through a cylinder, or gas supplied through a gas production device. The raw fuel may be biogas generated by fermentation of biodegradable substances, etc. The raw fuel may also be ammonia, hydrogen, etc. Water may be supplied to the reformer 23 as reforming water and vaporized into steam in a vaporization unit provided in the reformer 23. The fuel gas includes, for example, hydrogen gas.

[0017] The combustion section 24 may combust the unreacted fuel gas in the fuel cell 21 using the unreacted oxygen-containing gas. The combustion section 24 may combust the unreacted raw fuel in the reformer 23 using the unreacted oxygen-containing gas in the fuel cell 21. The combustion section 24 can heat the reformer 23 using heat generated by burning the unreacted fuel gas, etc. The combustion section 24 may be located vertically below the reformer 23 in the designed installation position of the fuel cell device 10, for example. The combustion section 24 may apply energy for causing a steam reforming reaction in the reformer 23 by heating the reformer 23.

[0018] The third temperature sensor 25 may be provided in the fuel cell 21. The third temperature sensor 25 may detect the temperature of the fuel cell 21. The fourth temperature sensor 26 may be provided in the exhaust gas treatment device 22 or on the outlet side of the exhaust gas treatment device 22. The fourth temperature sensor 26 may directly or indirectly detect the temperature of the combustion catalyst in the exhaust gas treatment device 22. The third temperature sensor 25 and the fourth temperature sensor 26 are, for example, thermocouples. The third temperature sensor 25 and the fourth temperature sensor 26 may provide the detected temperatures as information to the control device 14.

[0019] The first adjustment mechanism 27 may adjust the amount of air supplied to the fuel cell 21. The first adjustment mechanism 27 may be, for example, a blower with a changeable duty ratio. The first adjustment mechanism 27 may adjust the amount of air supplied based on the control of the control device 14.

[0020] The second adjustment mechanism 28 may adjust the amount of water supplied to the reformer 23. The second adjustment mechanism 28 may be, for example, a pump whose duty ratio is changeable. The second adjustment mechanism 28 may adjust the amount of water supplied based on the control of the control device 14.

[0021] The third adjustment mechanism 29 may adjust the amount of raw fuel supplied to the reformer 23. The third adjustment mechanism 29 may be, for example, a pump capable of changing the duty ratio. The third adjustment mechanism 29 may adjust the amount of raw fuel supplied based on the control of the control device 14.

[0022] As shown in FIG. 1, the first temperature sensor 19 may be provided at a location in the entire heat medium flow path 12 where the heat medium is expected to be at a relatively low temperature. The first temperature sensor 19 may be provided, for example, near the heat medium outlet of the heat storage tank 15. The first temperature sensor 19 may detect the temperature of the heat medium. The second temperature sensor 20 is provided at a location in the entire fuel cell device 10 away from elements that become hot, such as the module 11. The second temperature sensor 20 may detect the outside air temperature of the fuel cell device 10. The first temperature sensor 19 is, for example, a thermocouple. The second temperature sensor 20 is, for example, a thermistor. The first temperature sensor 19 and the second temperature sensor 20 may provide the detected temperatures to the control device 14 as information.

[0023] As shown in Fig. 1, the heat medium passage 12 is a passage for a heat medium that exchanges heat with the exhaust gas discharged from the module 11. Specifically, the heat medium passage 12 may circulate the heat medium between a heat storage tank 15 and a heat exchanger 16 described later. The heat medium is, for example, a fluid with a large specific heat, such as water or antifreeze. In the present disclosure, the heat medium is water. The heat medium passage 12 may be provided with a pump for pressurizing the heat medium.

[0024] The heat dissipation section 13 may be provided in the heat medium flow path 12. The heat dissipation section 13 has a heat dissipation flow path and a fan. The fan dissipates heat from the heat medium. Specifically, the fan may be capable of blowing air to the outer surface of the heat dissipation flow path. The fan blows air to the outer surface of the heat dissipation flow path, thereby dissipating heat from the heat medium flowing inside the heat dissipation flow path. The heat dissipation flow path is, for example, a radiator.

[0025] The heat storage tank 15 may store a heat medium. The heat medium stored in the heat storage tank 15 may circulate between the heat storage tank 15 and the heat exchanger 16 through the heat medium flow path 12. The heat storage tank 15 may be provided with a mechanism for heating, for example, water using the heat of the heat medium to supply hot water.

[0026] The heat exchanger 16 may exchange heat with a heat medium for the exhaust gas discharged from the module 11. The heat exchange cools the relatively high-temperature exhaust gas discharged from the module 11, causing water vapor to condense.

[0027] The gas-liquid separator 17 may separate the exhaust gas that has been heat exchanged in the heat exchanger 16 into gaseous exhaust gas and condensed liquid water. The gaseous exhaust gas may be discharged to the outside of the fuel cell device 10.

[0028] The water tank 18 may store the water separated in the gas-liquid separator 17. The water stored in the water tank 18 may be sent to the module 11, specifically to the above-mentioned reformer 23, as reforming water to be used in the steam reforming reaction.

[0029] The control device 14 includes at least one processor, at least one dedicated circuit, or a combination of these. The processor is a general-purpose processor such as a central processing unit (CPU) or a graphics processing unit (GPU), or a dedicated processor specialized for a specific process. The dedicated circuit may be, for example, a field-programmable gate array (FPGA), an application specific integrated circuit (ASIC), or the like. The control device 14 may control the operation of the fuel cell device 10.

[0030] For example, when the temperature of the fuel cell 21 is equal to or higher than a first temperature, or when the temperature of the combustion catalyst is equal to or higher than a second temperature, the control device 14 executes a first control to increase the amount of air supplied to the fuel cell 21 and to increase the rotation speed of the fan. Increasing the rotation speed of the fan may include transitioning the fan from a stopped state to a rotation start state. The increase in the rotation speed of the fan may be an increase to the maximum rotation speed.

[0031] The first temperature is a temperature that allows the deterioration of the fuel cell 21 to be estimated. The first temperature may be set to, for example, the upper limit of the temperature range during rated operation or a temperature higher than that. The second temperature is a temperature that allows the occurrence of incomplete combustion in the combustion section 24 to be estimated. Specifically, during rated operation, exhaust gas is completely combusted in the combustion section 24, and the amount of carbon monoxide generated is small. Under such circumstances, the amount of carbon monoxide burned in the combustion catalyst is small, and the amount of heat generated is also small. On the other hand, under circumstances in which incomplete combustion occurs, the amount of carbon monoxide generated is greater than during complete combustion, and the amount of heat generated in the combustion catalyst is large. Therefore, the temperature at which the combustion catalyst reaches the minimum value of the amount of carbon monoxide generated that determines in the design that incomplete combustion occurs in the combustion section 24 may be set to the second temperature.

[0032] The control device 14 may perform the first control when the temperature of the fuel cell 21 continues to be equal to or higher than the first temperature for a predetermined time. Alternatively, the control device 14 may perform the first control when the temperature of the combustion catalyst continues to be equal to or higher than the second temperature for a predetermined time. The predetermined time may be set to a time interval during which it can be determined that the temperature information is not instantaneous and that an overheating in the fuel cell 21 and incomplete combustion in the combustion section 24 have occurred. The control device 14 may increase the fan rotation speed in the first control when the temperature detected by the first temperature sensor 19 is higher than the temperature detected by the second temperature sensor 20.

[0033] Furthermore, the control device 14 may execute a second control to increase the amount of water supplied to the reformer 23 when the temperature of the fuel cell 21 is equal to or higher than a third temperature. The third temperature may be higher than the first temperature. The third temperature may be set to a temperature that allows estimation of deterioration of the reforming catalyst in the reformer 23, for example. The control device 14 may execute a third control to further increase the amount of air supplied to the fuel cell 21 when the temperature of the fuel cell 21 is equal to or higher than the third temperature. The control device 14 may perform the second control and the third control when the temperature of the fuel cell 21 continues to be equal to or higher than the third temperature for a predetermined time.

[0034] Furthermore, the control device 14 may execute a fourth control to reduce the amount of water and air supplied to the fuel cell 21 when the temperature of the fuel cell 21 falls below a fourth temperature after execution of at least one of the first control, the second control, and the third control. Specifically, the control device 14 reduces the amount of water and air supplied to the fuel cell 21 from the amount of water supplied to the reformer 23 and the amount of air supplied to the fuel cell 21, respectively, during execution of at least one of the first control, the second control, and the third control. The fourth temperature may be higher than the first temperature and lower than the third temperature. The fourth temperature may be, for example, an intermediate temperature between the first temperature and the third temperature. The control device 14 may execute the fourth control when the temperature of the fuel cell 21 continues to be lower than the fourth temperature for a predetermined time.

[0035] Moreover, the control device 14 may execute a fifth control to reduce the rotation speed of the fan if the temperature of the fuel cell 21 falls below the fifth temperature after the fourth control is executed. The fifth temperature may be lower than the first temperature. The fifth temperature may be, for example, the upper limit temperature during rated operation. The reduction in the rotation speed of the fan may be at least lower than the rotation speed of the fan during the execution of the fourth control, and may be to return the rotation speed to the rotation speed immediately before the execution of the first control. In the fifth control, the control device 14 may further return the amount of water supplied to the reformer 23 and the amount of air supplied to the fuel cell 21 to the amount of water and air supplied immediately before the execution of the first control. The control device 14 may execute the fifth control if the temperature of the fuel cell 21 continues to be lower than the fifth temperature for a predetermined time. The control device 14 may return to the execution of the first control if the temperature of the fuel cell 21 has not fallen below the fifth temperature after the execution of the fourth control.

[0036] Moreover, the control device 14 may perform a sixth control to reduce the amount of air supplied to the fuel cell 21 when the temperature of the combustion catalyst falls below a sixth temperature after the first control is performed. The sixth temperature may be set lower than the second temperature, and may be determined within a temperature range in which misfire is not expected during rated operation. The absolute value of the amount of air reduced in the sixth control may be less than the absolute value of the amount of air increase in the first control. The control device 14 may perform the sixth control when the temperature of the combustion catalyst continues to be lower than the sixth temperature for a predetermined time. After performing the sixth control, the control device 14 may again determine whether the temperature of the combustion catalyst falls below the sixth temperature. When the temperature of the combustion catalyst falls below the sixth temperature, the control device 14 may repeat the sixth control until the amount of air supplied before the first control is performed is reached. In other words, the control device 14 may gradually or stepwise reduce the amount of air supplied to the fuel cell 21 based on the confirmation of the temperature of the combustion catalyst. Alternatively, the control device 14 may reduce the amount of air supplied to the fuel cell 21 in one go to a lower limit value determined by the sixth control. When the amount of air supplied to the fuel cell 21 by the sixth control has returned to the amount of air supplied before the first control was executed, the control device 14 may return the amount of water supplied to the reformer 23 and the fan rotation speed to the water supply amount and the fan rotation speed before the first control was executed.

[0037] Next, the first excessive temperature rise suppression process executed by the control device 14 in this embodiment will be described with reference to the flowchart of Fig. 3. The first excessive temperature rise suppression process is started periodically while the fuel cell device 10 is in operation, for example.

[0038] In step S100, the control device 14 determines whether the temperature of the fuel cell 21 has remained at or above the first temperature for a predetermined period of time. If so, the process proceeds to step S101. If not, the first temperature rise suppression process ends.

[0039] In step S101, the control device 14 determines whether the outside air temperature is equal to or higher than the temperature of the heat medium detected by the first temperature sensor 19. If the outside air temperature is equal to or higher than the temperature of the heat medium, the process proceeds to step S102. If the outside air temperature is not equal to or higher than the temperature of the heat medium, the process proceeds to step S103.

[0040] In step S102, the controller 14 stores the rotation speed of the fan. The controller 14 also increases the rotation speed of the fan. After the increase, the process proceeds to step S103.

[0041] In step S103, the control device 14 stores the flow rate of the air supplied to the fuel cell 21. After storage, the process proceeds to step S104.

[0042] In step S104, the controller 14 increases the flow rate of the air supplied to the fuel cell 21 from the flow rate stored in step S103. After the increase, the process proceeds to step S105.

[0043] In step S105, the control device 14 determines whether the state in which the temperature of the fuel cell 21 is equal to or higher than the third temperature continues for a predetermined time. If it continues, the process proceeds to step S106. If it does not continue, the process proceeds to step S107.

[0044] In step S106, the controller 14 further increases the flow rate of air supplied to the fuel cell 21 from the flow rate adjusted in step S104. The controller 14 also stores the flow rate of water supplied to the reformer 23. The controller 14 also increases the flow rate of water supplied to the reformer 23 from the stored flow rate. After the increase, the process proceeds to step S107.

[0045] In step S107, the control device 14 determines whether the state in which the temperature of the fuel cell 21 has dropped below the fourth temperature continues for a predetermined time. If it continues, the process proceeds to step S108. If it does not continue, the process returns to step S107.

[0046] In step S108, the controller 14 reduces the flow rate of air supplied to the fuel cell 21. The controller 14 also reduces the flow rate of water supplied to the reformer 23. After the reduction, the process proceeds to step S109.

[0047] In step S109, the control device 14 determines whether the state in which the temperature of the fuel cell 21 has dropped below the fifth temperature continues for a predetermined time. If so, the process proceeds to step S110. If not, the process returns to step S104.

[0048] In step S110, the controller 14 returns the flow rate of the air supplied to the fuel cell 21 to the flow rate stored in step S103. The controller 14 also returns the flow rate of the water supplied to the reformer 23 to the flow rate stored in step S106. Note that if step S106 has not been passed through in the first excessive temperature rise suppression process, the water flow rate is not returned. The controller 14 also returns the fan rotation speed to the rotation speed stored in step S102. After the flow rates etc. have been returned, the first excessive temperature rise suppression process ends.

[0049] Next, the second excessive temperature rise suppression process executed by the control device 14 in this embodiment will be described with reference to the flowchart of Fig. 4. The second excessive temperature rise suppression process is started periodically while the fuel cell device 10 is in operation, for example.

[0050] In step S200, the control device 14 determines whether the state in which the temperature of the combustion catalyst is equal to or higher than the second temperature continues for a predetermined time. If it continues, the process proceeds to step S201. If it does not continue, the second temperature rise suppression process ends.

[0051] In steps S201 to S204, the control device 14 performs the same control as in steps S101 to S104 of the first excessive temperature rise suppression process. After the air flow rate is stored in step S104, the process proceeds to step S205.

[0052] In step S205, the control device 14 determines whether the state in which the temperature of the combustion catalyst is lowered below the sixth temperature continues for a predetermined time. If it continues, the process proceeds to step S206. If it does not continue, the process proceeds to step S207.

[0053] In step S206, the controller 14 reduces the flow rate of the air supplied to the fuel cell 21 by less than the fluctuation amount increased in step S204. After the reduction, the process proceeds to step S207.

[0054] In step S207, the control device 14 determines whether the flow rate of the air supplied to the fuel cell 21 is equal to or less than the flow rate stored in step S203. If it is equal to or less than the stored flow rate, the process proceeds to step S208. If it is not equal to or less than the stored flow rate, the process returns to step S205.

[0055] In step S208, the control device 14 returns the rotation speed of the fan to the rotation speed stored in step S202. After the rotation speed is returned, the second excessive temperature rise suppression process ends.

[0056] The fuel cell device 10 of the present embodiment configured as described above includes a module 11 having a fuel cell 21 that generates power using fuel gas and air and an exhaust gas treatment unit 22 that accommodates a combustion catalyst that treats exhaust gas discharged from the fuel cell 21, a heat medium flow path 12 for a heat medium that exchanges heat with the exhaust gas discharged from the module 11, a heat dissipation unit 13 that is provided in the heat medium flow path 12 and has a fan that dissipates heat of the heat medium, and a control device 14 that increases the amount of air supplied to the fuel cell 21 and increases the rotation speed of the fan when the temperature of the fuel cell 21 is equal to or higher than a first temperature or when the temperature of the combustion catalyst is equal to or higher than a second temperature. As described above, due to fluctuations in the composition of hydrocarbons in the raw fuel, the amount of combustible gas including fuel gas supplied to the fuel cell 21 may increase more than the amount assumed in rated operation. Under such circumstances, the heat generated by the combustion in the combustion unit 24 increases, and as a result, the temperature of the fuel cell 21 may deviate from the appropriate temperature. In addition, since the temperature rise of the combustion catalyst occurs before the temperature rise of the fuel cell 21, the temperature rise of the fuel cell 21 is predicted by the temperature rise of the combustion catalyst. In response to such an event, the fuel cell device 10 having the above-mentioned configuration can suppress the overheating of the fuel cell 21 by increasing the amount of air supplied to the fuel cell 21. Furthermore, when the amount of air is increased, the amount of exhaust gas discharged from the module 11 also increases. When the amount of exhaust gas increases, the amount of heat exchanged per unit amount of exhaust gas decreases. Therefore, the amount of water contained in the exhaust gas discharged from the module 11 that is not recovered by the fuel cell device 10 and is discharged to the outside increases. In response to such an event, the fuel cell device 10 having the above-mentioned configuration can improve the water recovery efficiency by increasing the rotation speed of the fan to cool the heat medium. Note that the water recovery efficiency here includes the case where the absolute amount of water returning to the water tank 18 increases as well as the proportion of water returning to the water tank 18.

[0057] Moreover, in the fuel cell device 10, the module 11 further includes a reformer 23 that generates fuel gas by steam reforming raw fuel and water, and the control device 14 increases the amount of water supplied to the reformer 23 when the temperature of the fuel cell 21 is equal to or higher than a third temperature higher than the first temperature. With this configuration, the fuel cell device 10 indirectly lowers the temperature of the fuel cell 21 because the heat of vaporization absorbed in the reformer 23 increases as the amount of water supplied to the reformer 23 increases. Therefore, the fuel cell device 10 lowers the temperature of the fuel cell 21, thereby causing a decrease in the temperature of the exhaust gas discharged from the module 11, and therefore the water recovery efficiency can be improved even when the temperature of the fuel cell 21 cannot be lowered by simply increasing the amount of air.

[0058] Furthermore, the fuel cell device 10 further increases the amount of air supplied to the fuel cell 21 when the temperature of the fuel cell 21 is equal to or higher than the third temperature. With this configuration, the fuel cell device 10 can improve the water recovery efficiency even when the previously increased amount of air is not enough to lower the temperature of the fuel cell 21.

[0059] Furthermore, the fuel cell device 10 reduces the amount of water and air supplied to the fuel cell 21 when the temperature of the fuel cell 21 falls below a fourth temperature that is higher than the first temperature and lower than the third temperature. With this configuration, the fuel cell device 10 reduces the amount of air and water in a situation where it can be estimated that excessive temperature rise in the fuel cell 21 has been suppressed to some extent, thereby making it possible to reduce the amount of water discharged to the outside of the fuel cell device 10. As a result, the fuel cell device 10 further improves the water recovery efficiency.

[0060] Furthermore, the fuel cell device 10 reduces the fan rotation speed when the temperature of the fuel cell 21 falls below a fifth temperature that is lower than the first temperature. With this configuration, the fuel cell device 10 can determine that the situation is such that there is a low risk of a decrease in water recovery efficiency, and reduce the load on the fan by increasing the fan rotation speed. As a result, the fuel cell device 10 can reduce the power consumption of the fan. Particularly in a configuration in which the fan is driven using power generated by the fuel cell 21, the fuel cell device 10 can suppress a decrease in power generation efficiency.

[0061] In one embodiment, (1) a fuel cell device comprising: a fuel cell that generates electricity using fuel gas and air, and a module having an exhaust gas treatment device that accommodates a combustion catalyst that treats exhaust gas discharged from the fuel cell; a heat medium flow path for a heat medium that exchanges heat with the exhaust gas discharged from the module; a heat dissipation unit provided in the heat medium flow path and having a fan that dissipates heat from the heat medium; and a control device that increases the amount of air supplied to the fuel cell and increases the rotation speed of the fan when the temperature of the fuel cell is equal to or higher than a first temperature or when the temperature of the combustion catalyst is equal to or higher than a second temperature.

[0062] (2) In the fuel cell device described above in (1), The module further includes a reformer for generating the fuel gas by steam reforming a raw fuel and water; The control device increases the amount of water supplied to the reformer when the temperature of the fuel cell is equal to or higher than a third temperature that is higher than the first temperature.

[0063] (3) In the fuel cell device described in (2) above, When the temperature of the fuel cell is equal to or higher than the third temperature, the control device further increases the amount of air supplied to the fuel cell.

[0064] (4) In the fuel cell device according to (2) or (3), The control device reduces the amount of water and air supplied to the fuel cell when the temperature of the fuel cell drops below a fourth temperature that is higher than the first temperature and lower than the third temperature.

[0065] (5) In any one of the fuel cell devices described above in (1) to (4), The control device reduces the rotation speed of the fan when the temperature of the fuel cell falls below a fifth temperature that is lower than the first temperature.

[0066] In one embodiment, the fuel cell device (6) comprises: a module having a fuel cell that generates electricity using a fuel gas and air, and a reformer that generates the fuel gas by steam reforming a raw fuel and water; and a control device that increases an amount of water supplied to the reformer when the temperature of the fuel cell is equal to or higher than a first temperature.

[0067] (7) In the fuel cell device according to (6) above, the module further includes an exhaust gas treatment unit that accommodates a combustion catalyst for treating exhaust gas discharged from the fuel cell; The control device increases the rotation speed of a fan that dissipates heat from a heat medium in a heat dissipation section provided in a heat medium flow path of the heat medium that exchanges heat with the exhaust gas discharged from the module, when the temperature of the fuel cell is equal to or higher than a first temperature.

[0068] The above describes an embodiment of the fuel cell device 10. However, the embodiment of the present disclosure can also be implemented as a method or program for implementing the device, or as a storage medium on which a program is recorded (for example, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a CD-RW, a magnetic tape, a hard disk, or a memory card, etc.).

[0069] Furthermore, the implementation form of the program is not limited to application programs such as object code compiled by a compiler or program code executed by an interpreter, but may be in the form of a program module incorporated into an operating system, etc. Furthermore, the program may or may not be configured so that all processing is performed only by the CPU on the control board. The program may be configured so that a part or all of it is executed by another processing unit mounted on an expansion board or expansion unit added to the board as necessary.

[0070] The drawings for explaining the embodiments according to the present disclosure are schematic, and the dimensional ratios and the like in the drawings do not necessarily correspond to the actual ones.

[0071] Although the embodiments of the present disclosure have been described based on the drawings and examples, it should be noted that those skilled in the art can make various modifications or alterations based on the present disclosure. Therefore, it should be noted that these modifications or alterations are included in the scope of the present disclosure. For example, the functions, etc. included in each component, etc. can be rearranged so as not to cause logical inconsistencies, and multiple components, etc. can be combined into one or divided.

[0072] All of the features described in this disclosure and / or all steps of any method or process disclosed herein may be combined in any combination except those combinations in which the features are mutually exclusive. Also, each feature described in this disclosure may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly denied. Thus, unless expressly denied, each disclosed feature is only one example of a generic series of the same or equivalent features.

[0073] Furthermore, the embodiments of the present disclosure are not limited to any of the specific configurations of the embodiments described above, but rather extend to any novel feature or combination of features described herein, or any novel method or process step or combination of features described herein.

[0074] For example, in this embodiment, when the temperature of the fuel cell 21 is equal to or higher than the first temperature, the amount of air supplied to the fuel cell 21 is increased to suppress excessive heating of the fuel cell 21. However, the effect of suppressing excessive heating of the fuel cell 21 can also be obtained by increasing the amount of water supplied to the reformer 23 instead of increasing the amount of air.

[0075] In this disclosure, descriptions such as "first" and "second" are identifiers for distinguishing the configuration. Configurations distinguished by descriptions such as "first" and "second" in this disclosure may have their numbers exchanged. For example, a first temperature sensor may exchange identifiers "first" and "second" with a second temperature sensor. The exchange of identifiers is performed simultaneously. The configurations remain distinguished even after the exchange of identifiers. Identifiers may be deleted. A configuration from which an identifier has been deleted is distinguished by a symbol. Descriptions of identifiers such as "first" and "second" in this disclosure should not be used solely to interpret the order of the configurations or to justify the existence of an identifier with a smaller number. [Explanation of symbols]

[0076] 10 Fuel cell device 11 Modules 12 Heat transfer medium flow path 13 Heat radiation part 14 Control device 15 Heat storage tank 16 Heat exchanger 17 Gas-liquid separator 18 Water Tank 19 First temperature sensor 20 Second Temperature Sensor 21 Fuel Cell 22 Exhaust gas treatment unit 23 Reformer 24 Combustion section 25 Third Temperature Sensor 26 4th Temperature Sensor 27 First Adjustment Mechanism 28 Second Adjustment Mechanism 29 The third adjustment mechanism

Claims

1. a fuel cell that generates electricity using fuel gas and air, and a module having an exhaust gas treatment device that accommodates a combustion catalyst that treats exhaust gas discharged from the fuel cell; a heat medium flow path for a heat medium that exchanges heat with the exhaust gas discharged from the module; a heat dissipation unit provided in the heat medium flow path and having a fan that dissipates heat from the heat medium; a control device that increases the amount of air supplied to the fuel cell and increases the rotation speed of the fan when the temperature of the fuel cell is equal to or higher than a first temperature or when the temperature of the combustion catalyst is equal to or higher than a second temperature. Fuel cell device.

2. 2. The fuel cell device according to claim 1, The module further includes a reformer for generating the fuel gas by steam reforming a raw fuel and water; The control device increases an amount of water supplied to the reformer when the temperature of the fuel cell is equal to or higher than a third temperature that is higher than the first temperature. Fuel cell device.

3. 3. The fuel cell device according to claim 2, The control device further increases the amount of air supplied to the fuel cell when the temperature of the fuel cell is equal to or higher than the third temperature. Fuel cell device.

4. 3. The fuel cell device according to claim 2, The control device reduces the amount of water and air supplied to the fuel cell when the temperature of the fuel cell drops below a fourth temperature that is higher than the first temperature and lower than the third temperature. Fuel cell device.

5. 5. The fuel cell device according to claim 4, The control device reduces the rotation speed of the fan when the temperature of the fuel cell falls below a fifth temperature that is lower than the first temperature. Fuel cell device.

6. a module having a fuel cell that generates electricity using a fuel gas and air, and a reformer that generates the fuel gas by steam reforming a raw fuel and water; a control device that increases an amount of water supplied to the reformer when the temperature of the fuel cell is equal to or higher than a first temperature. Fuel cell device.

7. 7. The fuel cell device according to claim 6, the module further includes an exhaust gas treatment unit that accommodates a combustion catalyst for treating exhaust gas discharged from the fuel cell; The control device increases the rotation speed of a fan that radiates heat of a heat medium provided in a heat radiating section provided in a heat medium flow path of the heat medium that exchanges heat with the exhaust gas discharged from the module when the temperature of the fuel cell is equal to or higher than a first temperature. Fuel cell device.

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