JP2006107956A - Fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell system capable of preventing the instability of a cell voltage by suppressing a CO concentration in reformed gas supplied to a cell body within a tolerance even in an abrupt load variation, and having a stable load following function by treating unburned components such as CO or methane generated by the instability of transitional burner combustion. <P>SOLUTION: In the fuel cell system supplying reformed gas obtained by reforming raw fuel by a fuel reformer to the cell body, a photocatalytic reactor treating the reformed gas and an ultraviolet irradiation device irradiating ultraviolet rays to the photocatalytic reactor are installed in the upstream of the cell body. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fuel cell system that supplies a reformed gas obtained by reforming raw fuel with a fuel reformer to a battery body, and a reformed gas obtained by reforming raw fuel with a fuel reformer. In addition, the present invention relates to a fuel cell system in which exhaust fuel discharged from the battery body is combusted by a burner of the fuel reformer.

  In general, a fuel cell system generates electricity by electrochemically reacting hydrogen obtained by reforming a hydrocarbon-based fuel such as city gas and oxygen in the air, resulting in high power generation efficiency. There is. Moreover, it has been evaluated as an environmentally friendly power generation system with low emission of air pollutants and low noise. The type of fuel cell is classified according to the type of electrolyte, but recently, a fuel cell of a type using a solid polymer membrane as the electrolyte has been actively developed for general household use.

  As a configuration example of such a fuel cell system, there is a system including a reformer, a CO converter, a CO selective oxidizer, and a fuel cell main body (see, for example, Patent Document 1). The raw fuel supplied from the city gas pipe is mixed with the steam required for reforming and then supplied to the reformer, where the reforming reaction and shift reaction shown in the following chemical reaction formula proceed simultaneously. The reformed gas is rich in hydrogen (high hydrogen concentration; the same applies hereinafter).

CH ₄ + H ₂ O → CO ₂ + 3H ₂ (reforming reaction)

CO + H ₂ O → CO ₂ + H ₂ (shift reaction)

  Next, in order to further reduce the CO concentration in the reformed gas to obtain a hydrogen-rich reformed gas, the gas exiting the reformer is supplied to the CO converter, and the CO is converted by the following shift reaction. The concentration is reduced. At this time, the CO concentration at the CO transformer outlet is about 1%.

CO + H ₂ O → CO ₂ + H ₂ (shift reaction)

  It is known that CO contained in the reformed gas becomes a catalyst poison of the battery main body, and the voltage drop of the battery main body becomes more remarkable as the operating temperature is lower. In particular, since the operating temperature of the polymer electrolyte fuel cell is a relatively low temperature of about 80 ° C., the allowable value of the CO concentration needs to be suppressed to about 10 ppm. Therefore, in the conventional polymer electrolyte fuel cell system, it is necessary to install a CO selective oxidizer downstream of the CO converter, and a small amount of air is mixed with the reformed gas exiting the CO converter. Then, the CO selective oxidizer was supplied, and the following CO oxidation reaction was selectively advanced to reduce the CO concentration.

CO + (1/2) O ₂ → CO ₂ (CO oxidation reaction)

The reformed gas exiting the CO selective oxidizer is supplied to the fuel electrode of the fuel cell, and an electrochemical reaction proceeds in the cell body to generate DC power. In general, about 80% of the reformed gas supplied to the battery body contributes to power generation, and the rest is supplied to the reformer burner as exhaust fuel containing unreacted hydrogen and is subjected to combustion treatment. Heat is recovered as a heat source for the reaction.
JP 2003-197238 A

  Now, in the above-described fuel cell system, particularly when installed for home use, there is often a demand for an operation that follows the load fluctuation of the home. In general, because the load fluctuation speed for home use is very fast, in the fuel cell system, the operating temperature of these reactors fluctuates due to the temperature tracking delay due to the heat capacity of the CO converter, CO selective oxidizer, etc. It becomes difficult to control the CO concentration of the reformed gas within the allowable value of the battery body. Therefore, there has been a problem that the battery voltage becomes unstable due to the CO concentration fluctuation at the time of load fluctuation, and furthermore, the load following operation becomes difficult.

  In addition, since the flow rate of exhaust fuel discharged from the fuel cell body changes with load fluctuations, the burner combustibility becomes transiently unstable due to the delay in following the combustion air of the reformer burner. There has been a problem that unburned components such as such are transiently discharged.

  The present invention has been made in order to solve the above-described problems, and suppresses the CO concentration in the reformed gas supplied to the battery body within an allowable range even during a sudden load fluctuation, thereby making the battery voltage unstable. To obtain a fuel cell system capable of providing a stable load following function by enabling non-combustion and processing unburned components such as CO and methane generated by transient instability of burner combustion With the goal.

  The present invention relates to a fuel cell system for supplying a reformed gas obtained by reforming raw fuel with a fuel reformer to a cell body, and a photocatalytic reactor for processing the reformed gas upstream of the cell body; And an ultraviolet irradiation device for irradiating the photocatalytic reactor with ultraviolet rays.

  In addition, an air supply means for mixing air with the reformed gas is further provided upstream of the photocatalytic reactor.

  Further, when the battery voltage of the battery main body is lower than a predetermined value, the photocatalytic reaction of the photocatalytic reactor is performed by irradiating ultraviolet rays from the ultraviolet irradiating device, and the air supply means performs the modification. The air is mixed with the quality gas.

  The power of the ultraviolet irradiation device is supplied from the battery body.

  The photocatalytic reactor is filled with a photocatalytic member made of a transparent spherical resin having a photocatalyst coated on the surface.

  Moreover, the container filled with the photocatalyst member of the photocatalyst reactor is provided with a transparent wall capable of transmitting ultraviolet rays irradiated from the ultraviolet irradiation device.

  The container filled with the photocatalyst member of the photocatalyst reactor is a light shielding member that shields the ultraviolet rays irradiated from the ultraviolet irradiation device, and conducts light that guides the ultraviolet rays irradiated from the ultraviolet irradiation device to the inside of the container. Means are provided.

  The inner surface of the container is coated with a photocatalyst.

  The photocatalyst is titanium oxide.

  The photocatalyst is obtained by adding ruthenium to titanium oxide.

  A fuel cell that supplies a reformed gas obtained by reforming raw fuel with a fuel reformer to the battery body, and burns exhaust fuel discharged from the battery body with a burner of the fuel reformer. The system includes a photocatalytic reactor for treating exhaust gas after being burned by the burner, and an ultraviolet irradiation device for irradiating the photocatalytic reactor with ultraviolet rays.

  Further, when the load fluctuation of the battery main body is larger than a predetermined value, the photocatalytic reaction of the photocatalytic reactor is performed by irradiating the ultraviolet ray from the ultraviolet ray irradiation device.

  In addition, when the battery body is started, the photocatalytic reaction of the photocatalytic reactor is performed by irradiating ultraviolet rays from the ultraviolet irradiation device.

  In addition, when the battery main body is stopped, the photocatalytic reaction of the photocatalytic reactor is performed by irradiating ultraviolet rays from the ultraviolet irradiation device.

  Therefore, according to the present invention, the CO voltage in the reformed gas supplied to the battery body is kept within an allowable range so that the battery voltage does not become unstable during sudden load fluctuations or during transition from start to load. This makes it possible to achieve a stable load following function.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 shows a configuration example of a fuel cell system according to an embodiment of the present invention.

  In the figure, the raw fuel is reformed into a gas having a high hydrogen concentration (hydrogen rich gas) by the reforming reaction of the fuel reformer, and then sent to the CO converter 2. The CO converter 2 further increases the hydrogen concentration of the hydrogen rich gas output from the fuel reformer 1 by a shift reaction, and the hydrogen rich gas output from the CO converter 2 is mixed with air to select CO. It is sent to the oxidizer 3.

  The CO selective oxidizer 3 is for further reducing CO that becomes a catalyst poison of the battery main body 10 by a CO selective oxidation reaction of the hydrogen rich gas mixed with air. The hydrogen rich gas emitted from the CO selective oxidizer 3 Is mixed with the air supplied through the on-off valve 4, sent to the photocatalytic reactor 5, and after passing through the photocatalytic reactor 5, is supplied to the hydrogen electrode of the battery body 6. Further, the gas discharged from the battery body 6 is sent to the burner 1a of the fuel reformer 1, where it is burned by the burner 1a, and is recovered as a heat source for the reforming reaction of the fuel reformer 1. The combustion exhaust gas discharged from the burner 1a is released into the atmosphere.

  The ultraviolet irradiation device 7 is for irradiating the photocatalytic reactor 5 with ultraviolet rays, and its power is supplied from the battery body 6. The voltmeter 8 measures the stack voltage of the battery body 6, and the ammeter 9 measures the load current of the power output from the battery body 6. The voltage measurement value Vs of the voltmeter 8 and the current measurement value Is of the ammeter 9 are added to the control device 10.

  The control device 10 calculates a reference value of the output voltage of the battery body 6 based on the current measurement value Is and the operation time, and based on a comparison between the reference value and the voltage measurement value Vs, when the load changes or from the start-up. In the transition state of the load transition, it is detected that the battery voltage has decreased from the reference value, the operation of the ultraviolet irradiation device 7 is started by the control signal SS1, the photocatalytic reactor 5 is irradiated with ultraviolet rays, and the control signal SS2 Thus, the on-off valve 4 is opened to supply air required for CO oxidation to the photocatalytic reactor 5.

  FIG. 2A shows a configuration example of the photocatalytic reactor 5.

  In the figure, the wall member 5a is made of a transparent material, and the inside thereof is filled with a large number of photocatalyst particles BZ. The upper and lower sides of the wall member 5a are sealed by lid members 5d and 5e through seal members 5b and 5c, respectively, and a gas to be processed flows from a hole formed in the central portion of the lid member 5d. The treated gas flows out from the hole formed in the central portion of the lid member 5e.

  Further, the ultraviolet irradiation lamps 7a and 7b of the ultraviolet irradiation device 7 are disposed outside the wall member 5a of the photocatalytic reactor 5, and the ultraviolet light output from the ultraviolet irradiation lamps 7a and 7b passes through the wall member 5a. The light passes through and is irradiated to the photocatalyst particles BZ accommodated therein.

  An example of the photocatalyst particles BZ is shown in FIG.

  This photocatalyst particle BZ is obtained by coating photocatalyst TO on a transparent resin particle CR molded into a spherical shape. Here, as photocatalyst TO, the thing which added ruthenium to titanium oxide and titanium oxide can be used.

  FIG. 3 shows a configuration example of the control device 10.

  In the figure, the current measurement value Is and the operation time Hr output from the ammeter 9 are added to the reference value calculation unit 10a. The reference value calculation unit 10a calculates reference values V1, V2, and V3 of voltages corresponding to the current measurement value Is, for example, according to curves CV1, CV2, and CV3 as shown in FIG.

  Here, any one of the curves CV1, CV2, and CV3 is selected as the operation time Hr elapses. For example, when the operation time Hr is less than the time TA, the curve CV1 is selected, and when the operation time Hr is more than the time TA and less than TB, the curve CV2 is selected and the operation time Hr is more than the time TB. The curve CV3 is selected.

  Therefore, when the curve CV1 is selected, the value V1 is selected as the reference value VDC, and when the curve CV2 is selected, the value V2 is selected as the reference value VDC and the curve CV3 is selected. If so, the value V3 is selected as the reference value VDC.

  In this way, the reference value VDC calculated by the reference value calculation unit 10a is added as a reference value input to the difference calculation unit 10b. The voltage measurement value Vs output from the voltmeter 8 is added to the comparison value input of the difference calculation unit 10b, and the difference calculation unit 10b executes a difference calculation of (Vs−VDC), and the calculation result is obtained. It outputs to the determination calculating part 10c as difference value DV.

  When the absolute value of the difference value DV is equal to or smaller than the predetermined value, the determination calculation unit 10c determines that the battery voltage of the battery body 6 is within the reference value, and outputs the control signals SS1, SS2 off. As a result, the on-off valve 4 is closed and the ultraviolet irradiation device 7 is turned off (not lit). On the other hand, when the absolute value of the difference value DV exceeds the predetermined value, it is determined that the battery voltage of the battery body 6 has decreased from the reference value, and the control signals SS1 and SS2 are turned on. As a result, the on-off valve 4 is opened and the ultraviolet irradiation device 7 is turned on (lighted).

  With the above configuration, when operating this fuel cell system, the output voltage of the battery body 6 rises at the time of start-up, the output power of the battery body 6 gradually decreases at the time of stop, and the power load fluctuates. Along with this, the output voltage of the battery body 6 also varies.

  In such a state, when the control device 10 determines that the value of the voltage measurement value Vs of the battery body 6 has decreased below the reference value, the control signals SS1 and SS2 are turned on, whereby the on-off valve 4 Is opened, and the ultraviolet irradiation device 7 is turned on.

  As a result, air is mixed with hydrogen gas upstream of the photocatalytic reactor 5, and the photocatalytic particles BZ of the photocatalytic reactor 5 perform a photocatalytic reaction as shown in the following equation.

CO + (1/2) O ₂ + hν → CO ₂ (photocatalytic reaction)

    Here, hν is the energy of ultraviolet rays.

  As a result, the CO concentration of the reformed gas supplied to the battery body 6 can be reduced, and the battery voltage can be prevented from becoming unstable when the operation of the fuel cell system is unstable. Therefore, the load following function of the fuel cell system becomes more stable.

  FIG. 5 shows an example of a fuel cell system according to another embodiment of the present invention. In the figure, the same parts as those in FIG. 1 and corresponding parts are denoted by the same reference numerals.

  In the figure, the raw fuel is reformed into a gas having a high hydrogen concentration (hydrogen rich gas) by the fuel reformer, and then sent to the CO converter 2. The CO converter 2 further increases the hydrogen concentration of the hydrogen rich gas output from the fuel reformer 1 by a shift reaction, and the hydrogen rich gas output from the CO converter 2 is mixed with air to select CO. It is sent to the oxidizer 3.

  The CO selective oxidizer 3 is for further reducing CO that becomes a catalyst poison of the battery body 10 by a CO selective oxidation reaction of the hydrogen-rich gas mixed with air, and the hydrogen output from the CO selective oxidizer 3 The rich gas is sent to the photocatalytic reactor 5 and is supplied to the hydrogen electrode of the battery body 6 after passing through the photocatalytic reactor 5. Further, the gas discharged from the battery body 6 is sent to the burner 1a of the fuel reformer 1, where it is burned by the burner 1a, and is recovered as a heat source for the reforming reaction of the fuel reformer 1. The combustion exhaust gas discharged from the burner 1a passes through the photocatalytic reactor 5 and is then released into the atmosphere.

  The ultraviolet irradiation device 7 is for irradiating the photocatalytic reactor 5 with ultraviolet rays, and its power is supplied from the battery body 6. The voltmeter 8 measures the stack voltage of the battery body 6, and the ammeter 9 measures the load current of the power output from the battery body 6. The voltage measurement value Vs of the voltmeter 8 and the current measurement value Is of the ammeter 9 are added to the control device 10.

  The control device 10 calculates a reference value of the output voltage of the battery body 6 based on the current measurement value Is and the operation time, and based on a comparison between the reference value and the voltage measurement value Vs, when the load changes or from the start-up. In the transition state of the load transition, it is detected that the battery voltage has dropped from the reference value, the operation of the ultraviolet irradiation device 7 is started by the control signal SS1, and the photocatalytic reactor 6 is irradiated with ultraviolet rays.

  Therefore, when the output voltage of the battery main body 6 decreases and the control device 10 determines that the value of the voltage measurement value Vs of the battery main body 6 is lower than the reference value, the control signal SS1 is turned on, thereby Then, the ultraviolet irradiation device 7 is turned on.

  As a result, the photocatalyst particles BZ of the photocatalytic reactor 5 perform the photocatalytic reaction as described above, thereby obtaining an action in which CO and methane, which are unburned gas components contained in the exhaust gas, are subjected to a photolysis treatment. As a result, it is possible to obtain an effect of obtaining a fuel cell system capable of processing unburned components such as CO and methane generated by transient instability of burner combustion and providing a stable load following function.

  FIG. 6 shows an example of a fuel cell system according to still another embodiment of the present invention. In the figure, the same parts as those in FIG. 1 and corresponding parts are denoted by the same reference numerals.

  In the figure, the raw fuel is reformed into a gas having a high hydrogen concentration (hydrogen rich gas) by the fuel reformer, and then sent to the CO converter 2. The CO converter 2 further increases the hydrogen concentration of the hydrogen rich gas output from the fuel reformer 1 by a shift reaction, and the hydrogen rich gas output from the CO converter 2 is mixed with air to select CO. It is sent to the oxidizer 3.

  The CO selective oxidizer 3 is for further reducing CO that becomes a catalyst poison of the battery main body 10 by a CO selective oxidation reaction of the hydrogen rich gas mixed with air. The hydrogen rich gas emitted from the CO selective oxidizer 3 Is mixed with the air supplied through the on-off valve 4, sent to the photocatalytic reactor 5, and after passing through the photocatalytic reactor 5, is supplied to the hydrogen electrode of the battery body 6. Further, the gas discharged from the battery body 6 is sent to the burner 1a of the fuel reformer 1, where it is burned by the burner 1a, and is recovered as a heat source for the reforming reaction of the fuel reformer 1. The combustion exhaust gas discharged from the burner 1a passes through the photocatalytic reactor 5 'and is then released into the atmosphere.

  The ultraviolet irradiation devices 7 and 7 ′ are for irradiating the photocatalytic reactors 5 and 5 ′ with ultraviolet rays, and the power is supplied from the battery body 6. The voltmeter 8 measures the stack voltage of the battery body 6, and the ammeter 9 measures the load current of the power output from the battery body 6. The voltage measurement value Vs of the voltmeter 8 and the current measurement value Is of the ammeter 9 are added to the control device 10.

  The control device 10 calculates a reference value of the output voltage of the battery body 6 based on the current measurement value Is and the operation time, and based on a comparison between the reference value and the voltage measurement value Vs, when the load changes or from the start-up. In the transient state of load transition, it is detected that the battery voltage has dropped from the reference value, the operation of the ultraviolet irradiation device 7, 7 'is started by the control signal SS1, and the photocatalytic reactors 5, 5' are irradiated with ultraviolet rays At the same time, the on-off valve 4 is opened by the control signal SS2 to supply air necessary for CO oxidation to the photocatalytic reactor 5.

  With the above configuration, when the control device 10 determines that the value of the voltage measurement value Vs of the battery body 6 is lower than the reference value, the control signals SS1 and SS2 are turned on, whereby the on-off valve 4 is turned on. While the opening operation is performed, the ultraviolet irradiation devices 7 and 7 'are turned on.

  As a result, air is mixed with hydrogen gas upstream of the photocatalytic reactor 5, and the photocatalytic particles BZ of the photocatalytic reactors 5 and 5 'perform the photocatalytic reaction as described above.

  As a result, the CO concentration of the reformed gas supplied to the battery body 6 can be reduced, and the battery voltage can be prevented from becoming unstable when the operation of the fuel cell system is unstable. As a result, the load following function of the fuel cell system is further stabilized, and an action of photodecomposing CO and methane, which are unburned gas components contained in the exhaust gas, is obtained. As a result, it is possible to obtain an effect of obtaining a fuel cell system capable of processing unburned components such as CO and methane generated by transient instability of burner combustion and providing a stable load following function.

  FIG. 7 shows another example of the photocatalytic reactor 5. In the figure, the same parts as those in FIG. 2 and the corresponding parts are denoted by the same reference numerals.

  In the drawing, the wall member 5a 'is made of a material (for example, steel material) capable of blocking ultraviolet rays, and the inner wall surface of the wall member 5a' is coated with a photocatalyst 5f. The wall member 5a 'is filled with a large number of photocatalyst particles BZ. The upper and lower sides of the wall member 5a are sealed by the lid members 5d and 5e through the seal members 5b and 5c, respectively, and the gas to be processed flows from the hole formed in the central portion of the lid member 5d, The treated gas flows out from the hole formed in the central portion of the lid member 5e.

  Further, an optical fiber bundle FB for guiding the ultraviolet light output from the ultraviolet irradiation device 7 to the inside of the container of the photocatalytic reactor 5 ″ is provided.

  Therefore, the ultraviolet rays output from the ultraviolet irradiation device 7 are guided into the container of the photocatalytic reactor 5 ″ through the optical fiber bundle FB, irradiated to the photocatalytic particles BZ, and coated on the inner wall surface of the wall member 5a ′. The irradiated photocatalyst 5f is irradiated.

  Thereby, the photocatalytic reaction by the photocatalyst OT and the photocatalyst 5f on the surface of the photocatalyst particle BZ is obtained.

  FIG. 8A shows another example of the control device 10.

  In the figure, the current measurement value Is output from the ammeter 9 is added to the differential operation unit 10e. The differential calculation unit 10e calculates a fluctuation value Id of the current measurement value Is, and the fluctuation value Id output from the differentiation calculation unit 10e is added to the determination calculation unit 10f.

  When the absolute value of the input fluctuation value Id is within the predetermined range, the determination calculation unit 10f outputs the control signals SS1 and SS2 off and the absolute value of the input fluctuation value Id exceeds the predetermined range. In this case, the control signals SS1 and SS2 are turned on.

  Thereby, when the load fluctuation of the battery body 6 is large and the fluctuation of the load current is large, the control signals SS1 and SS2 output from the control device 10 'are turned on.

  FIG. 2B shows still another example of the control device 10.

  In the figure, various sequence data of the fuel cell system is added to the sequence determination unit 10h. The sequence discriminating unit 10h controls the control when the data representing the sequence state corresponding to the start-up operation period and the data representing the sequence state corresponding to the stop-operation period are added among the various sequence data input. The signals SS1 and SS2 are turned on, and in other cases, the control signals SS1 and SS2 are turned off.

  Thus, when the operation of the battery body 6 is unstable, such as when the fuel cell system is started and stopped, the control signals SS1 and SS2 output from the control device 10 'are turned on.

  In the embodiment described above, the case where the present invention is applied to a fuel cell system provided with a fuel processing system using a steam reforming system has been described. However, an autothermal reforming system or a part which is another system. The present invention can be similarly applied to a fuel cell system to which a combination of a fuel reformer and a battery exhaust fuel burner by an oxidation reforming method is applied.

1 is a block diagram showing a configuration example of a fuel cell system according to an embodiment of the present invention. FIG. 3 is a schematic cross-sectional view showing a configuration example of the photocatalytic reactor 5. FIG. 2 is a block diagram showing a configuration example of a control device 10. The graph for demonstrating the calculation operation | movement of the reference value calculating part of a control apparatus. The block diagram which showed an example of the fuel cell system concerning the other Example of this invention. The block diagram which showed an example of the fuel cell system concerning the further another Example of this invention. FIG. 6 is a schematic cross-sectional view showing another example of the photocatalytic reactor 5. The block diagram which showed the other example of the control apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel reformer 1a Burner 4 On-off valve 5, 5 ', 5 "Photocatalytic reactor 6 Battery main body 7, 7' Ultraviolet irradiation device 8 Voltmeter 9 Ammeter 10, 10 ', 10" Control device

Claims (14)

In a fuel cell system for supplying a reformed gas obtained by reforming raw fuel with a fuel reformer to a battery body,
Upstream of the battery body, a photocatalytic reactor for treating the reformed gas;
A fuel cell system comprising an ultraviolet irradiation device for irradiating the photocatalytic reactor with ultraviolet rays.   The fuel cell system according to claim 1, further comprising an air supply means for mixing air into the reformed gas upstream of the photocatalytic reactor.   When the battery voltage of the battery main body is lower than a predetermined value, the photocatalytic reaction of the photocatalytic reactor is performed by irradiating ultraviolet rays from the ultraviolet irradiating device, and the reformed gas is produced by the air supply means. 3. The fuel cell system according to claim 2, wherein air is mixed in the fuel cell system.   4. The fuel cell system according to claim 1, wherein the ultraviolet irradiating device is supplied with power from the battery body.   5. The fuel cell system according to claim 1, wherein the photocatalyst reactor is filled with a photocatalyst member made of a transparent spherical resin having a photocatalyst coated on the surface thereof. .   6. The fuel cell system according to claim 5, wherein the container filled with the photocatalytic member of the photocatalytic reactor includes a transparent wall capable of transmitting ultraviolet rays irradiated from the ultraviolet irradiation device.   The container filled with the photocatalyst member of the photocatalyst reactor is formed of a light shielding member that blocks ultraviolet rays irradiated from the ultraviolet irradiation device, and has a light conducting means for guiding the ultraviolet rays irradiated from the ultraviolet irradiation device to the inside of the container. 6. The fuel cell system according to claim 5, further comprising:   The fuel cell system according to claim 6 or 7, wherein the inner surface of the container is coated with a photocatalyst.   The fuel cell system according to claim 5 or 8, wherein the photocatalyst is titanium oxide.   9. The fuel cell system according to claim 5, wherein the photocatalyst is obtained by adding ruthenium to titanium oxide. In a fuel cell system in which reformed gas obtained by reforming raw fuel with a fuel reformer is supplied to a battery body, and exhaust fuel discharged from the battery body is combusted by a burner of the fuel reformer ,
A photocatalytic reactor for treating exhaust gas after being burned in the burner;
A fuel cell system comprising an ultraviolet irradiation device for irradiating the photocatalytic reactor with ultraviolet rays.   12. The photocatalytic reaction of the photocatalytic reactor is performed by irradiating ultraviolet rays from the ultraviolet irradiation device when the load fluctuation of the battery body is larger than a predetermined value. Fuel cell system.   12. The fuel cell system according to claim 11, wherein the photocatalytic reaction of the photocatalytic reactor is performed by irradiating ultraviolet rays from the ultraviolet irradiating device when the battery body is activated.   12. The fuel cell system according to claim 11, wherein the photocatalytic reaction of the photocatalytic reactor is performed by irradiating ultraviolet rays from the ultraviolet irradiation device when the battery body is stopped.

Images