JP2008105900A - Reforming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To warm up a reforming apparatus by reducing the repeating number of times of ignition/extinction in a combustion part, thereby keeping the durability of the combustion part/a reforming part highly. <P>SOLUTION: A controller in the reforming apparatus includes: a combustion starting means (steps 102 to 108) wherein, at the start of the reforming apparatus, fuel for combustion and oxidizer gas for combustion are fed, a combustion part is fired, and reforming water is fed to an evaporation part; a first fire extinguishing means (steps 110 to 114) wherein, after the start of the combustion in the combustion part, when a reforming part is heated-up to a first prescribed temperature, only the feed of the fuel for combustion to the combustion part is stopped, and the combustion part is fire-extinguished; and (steps 116, 104, 106) wherein, after the fire extinguishing in the combustion part by the first fire extinguishing means, the temperature of the reforming part drops to a second prescribed temperature lower than the first prescribed temperature before water vapor is heated-up to a prescribed temperature for water vapor, the feed of the fuel for combustion to the combustion part is restarted, and the combustion part is refired. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a reformer.

As one type of reformer, the one shown in Patent Document 1 is known. As shown in FIG. 4 of Patent Document 1, in the hydrogen generator, the first amount of gas is reduced by decreasing the amount of natural gas or increasing the amount of air from the blower 8 at the time of startup in step 4S. When the predetermined temperature is not 350 ° C. or lower, the control means 16 closes the on-off valve 15 and stops the supply of natural gas as a raw material in step 15S. The combustion part 7 is misfired by stopping the supply of natural gas, thereby lowering the temperature of the reforming part 1. Next, after detecting that the temperature of the reforming unit 1 has decreased to about 300 ° C. or less, which is an example of the third predetermined temperature of the present invention, in step 16S, the blowing unit 8 is turned on in step 17S. A device (not shown) is operated to open the on-off valve 15. And the control means 16 can operate the raw material supply part 2, can supply a raw material to the modification | reformation part 1, and can restart the combustion in the combustion part 7. FIG.
JP 2005-206395 A

  In the reforming apparatus described in Patent Document 1 described above, as shown in FIG. 19, the temperature of the reforming unit 1 is set within a low temperature range (300 ° C. to 350 ° C.) of the activation temperature range of the catalyst of the reforming unit 1. I have control. That is, the water vapor temperature reaches a predetermined temperature (100 ° C.) while repeating the ignition / extinguishing of the combustion section 7 relatively frequently. Therefore, since the number of times of ignition is large, there is a risk that the durability of the combustion part is deteriorated. Further, the durability of the reformed portion may be deteriorated due to thermal fatigue and thermal stress of the reformed portion due to repeated heat loads.

  The present invention has been made to solve the above-described problems. In the reformer, the number of repetitions of ignition / extinguishing of the combustion section is reduced, and the durability of the combustion section / reformation section is maintained to be high. The purpose is to warm up the quality device.

  In order to solve the above-mentioned problem, the structural feature of the invention according to claim 1 is that a reforming unit that supplies reforming fuel and reforming water to generate reformed gas, and evaporates the reforming water. An evaporating section that is supplied to the reforming section, and at least one of the combustible fuel, the reforming section, and each combustible gas from the fuel electrode of the fuel cell, and an oxidizing gas for combustion can be supplied. A combustion part that burns at least one of them with combustion oxidant gas to generate combustion gas, a combustion gas flow path in which the combustion gas from the combustion part heats the reforming part and the evaporation part in that order, At the time of starting the reformer, combustion start means for supplying combustion fuel and combustion oxidant gas, igniting the combustion section and supplying reforming water to the evaporation section, and reforming after the combustion section starts combustion When the temperature of the section rises to the first predetermined temperature, the supply of combustion fuel to the combustion section is stopped A first extinguishing means for extinguishing the combustion portion Te is to and a control unit; and a combustion oxidizing gas supply means for supplying combustion oxidizer gas during extinguishing of the combustion section.

  Further, the structural feature of the invention according to claim 2 is that in claim 1, the control device, after the fire extinguishing of the combustion section by the first fire extinguishing means, the temperature of the reforming section and the reforming supplied to the reforming section And a first re-ignition means for supplying combustion fuel or reforming fuel based on at least one of the water temperatures to re-ignite the combustion section.

  Further, the structural feature of the invention according to claim 3 is that in claim 2, the first re-ignition means is configured such that the temperature of the reforming water supplied to the reforming part is reduced after the combustion part is extinguished by the first fire extinguishing means. When the temperature of the reforming section is lowered to the second predetermined temperature lower than the first predetermined temperature before the temperature is increased to the predetermined temperature for steam, the supply of the fuel for combustion to the combustion section is resumed and the combustion section is reignited. It is.

  Further, the structural feature of the invention according to claim 4 is that, in claim 3, before the temperature of the reforming portion is raised to the first predetermined temperature after reignition with the fuel for combustion by the first reignition means, When the temperature of the reforming water supplied to the reforming unit is equal to or higher than the predetermined temperature for steam, the second fire extinguishing means for stopping only the supply of the fuel for combustion to the combustion unit, and then the reforming unit And a second re-ignition means for supplying reforming fuel to re-ignite the combustion section.

  Further, the structural feature of the invention according to claim 5 is that in claim 2, the first re-ignition means is such that the temperature of the reforming part is lower than the first predetermined temperature after the combustion part is extinguished by the first fire extinguishing means. When the temperature of the reforming water supplied to the reforming section is raised to the predetermined temperature for steam before the temperature is lowered to the second predetermined temperature, the supply of the fuel for combustion to the combustion section is resumed and the combustion section is re-ignited. It is.

  According to a sixth aspect of the present invention, in the fifth aspect, the first re-ignition means supplies the reforming fuel to the combustion section instead of supplying the combustion fuel to the combustion section. It is to reignite.

  Further, the structural feature of the invention according to claim 7 is that in claim 2, the first re-ignition means is configured such that the temperature of the reforming section reaches a third predetermined temperature between the first predetermined temperature and the second predetermined temperature. When the temperature of the reforming water supplied to the reforming section rises to a predetermined temperature for steam before the temperature is lowered, the supply of combustion fuel to the combustion section when the temperature of the reforming section drops to the third predetermined temperature And reigniting the combustion section.

  Further, the structural feature of the invention according to claim 8 is that in claim 7, the first re-ignition means supplies the reforming fuel to the reforming section instead of supplying the combustion fuel to the combustion section. Is to reignite.

  Further, the structural feature of the invention according to claim 9 is that in claim 2, the first re-ignition means is modified before the temperature of the reforming water supplied to the reforming section rises to a predetermined temperature for steam. When the temperature of the mass part is lowered to a third predetermined temperature between the first predetermined temperature and the second predetermined temperature, the temperature of the reforming water supplied to the reforming part is increased to the predetermined temperature for steam. Then, the supply of the fuel for combustion to the combustion part is started and the combustion part is reignited.

  The structural feature of the invention according to claim 10 is that, in claim 9, when the temperature of the reforming section is raised to the first predetermined temperature after reigniting with combustion fuel by the first reignition means, When the temperature of the reforming water supplied to the reforming unit is equal to or higher than the predetermined temperature for steam, the temperature of the reforming unit is increased to the first predetermined temperature, and the combustion fuel to the combustion unit is A second fire-extinguishing means for stopping only the supply, and a second re-igniting means for supplying reforming fuel to the reforming section and re-igniting the combustion section when the temperature of the reforming section is lowered to a third predetermined temperature. Is further provided.

  In the invention according to claim 1 configured as described above, the combustion start means supplies the combustion fuel and the combustion oxidant gas to ignite the combustion section when the reformer is started up, When the reforming water is supplied and the first fire extinguishing means raises the temperature of the reforming section to the first predetermined temperature after the combustion of the combustion section starts, the supply of the fuel for combustion to the combustion section is stopped and the combustion section The combustion oxidant gas supply means supplies the combustion oxidant gas during the fire extinguishing of the combustion section. As a result, the temperature of the reforming section can be lowered more quickly, and re-ignition becomes possible. Further, it is possible to avoid a temperature at which the casing of the reformer is likely to corrode.

  In the invention according to claim 2 configured as described above, in the invention according to claim 1, the first reignitioning unit is configured to reduce the temperature of the reforming unit and the reforming unit after extinguishing the combustion unit by the first extinguishing unit. A combustion fuel or a reforming fuel is supplied based on at least one of the temperatures of the reforming water supplied to the combustion chamber to reignite the combustion section. As a result, after the temperature of the reforming section has been raised to the first predetermined temperature, which is a relatively high temperature, until the fire is extinguished and reignited, the heat of the reforming section is downstream of the reforming section via the combustion air. It can be transmitted to the evaporation section located and heated. Therefore, the number of repetitions of ignition / extinguishing of the combustion section can be reduced to maintain the durability of the combustion section / reformation section high, and the reformer can be warmed up.

  In the invention according to claim 3 configured as described above, in the invention according to claim 2, the first re-ignition means is the reforming supplied to the reforming part after extinguishing the combustion part by the first extinguishing means. If the temperature of the reforming section falls to a second predetermined temperature lower than the first predetermined temperature before the temperature of the water rises to the predetermined temperature for steam, the supply of combustion fuel to the combustion section is resumed and the combustion section is Since reignition is performed, the number of repetitions of ignition and extinguishing of the combustion section can be reduced without lowering the temperature of the reforming section more than necessary.

  In the invention according to claim 4 configured as described above, in the invention according to claim 3, the temperature of the reforming section is raised to the first predetermined temperature after re-ignition with the fuel for combustion by the first re-ignition means. If the temperature of the reforming water supplied to the reforming section is equal to or higher than the predetermined temperature for steam before performing the second extinguishing means for stopping only the supply of the fuel for combustion to the combustion section, The second re-ignition means for supplying the reforming fuel to the reforming section and re-igniting the combustion section, so that the reforming fuel is charged while maintaining the temperature of the reforming section high, Coking in the reforming section can be reliably prevented.

  In the invention according to claim 5 configured as described above, in the invention according to claim 2, the first re-ignition means has a first predetermined temperature after the extinguishing of the combustion part by the first extinguishing means. When the temperature of the reforming water supplied to the reforming section rises to the predetermined temperature for steam before the temperature is lowered to the second predetermined temperature lower than the temperature, the supply of the combustion fuel to the combustion section is resumed and the combustion section is Since reignition is performed, the startup time can be shortened without unnecessarily lowering the temperature of the reforming section.

  In the invention according to claim 6 configured as described above, in the invention according to claim 5, the first re-ignition means supplies the reforming fuel to the reforming section instead of supplying the combustion fuel to the combustion section. Since supplying and re-igniting the combustion section, it becomes possible to start the reforming apparatus by using only the reforming fuel, so that the apparatus can be simplified.

  In the invention according to claim 7 configured as described above, in the invention according to claim 2, the first re-ignition means has a temperature of the reforming section between the first predetermined temperature and the second predetermined temperature. 3 When the temperature of the reforming water supplied to the reforming section rises to the predetermined temperature for steam before the temperature is lowered to the predetermined temperature, when the temperature of the reforming section falls to the third predetermined temperature, the combustion to the combustion section Fuel supply starts and the combustion section is ignited again. As a result, the temperature of the reforming section is always lowered to the third predetermined temperature and the combustion section is re-ignited, so that the heat of the reforming section due to overcombustion when the combustible gas supplied to the combustion section is the reformed gas. Damage can be suppressed.

  In the invention according to claim 8 configured as described above, in the invention according to claim 7, the first re-ignition means supplies the reforming fuel to the reforming section instead of supplying the combustion fuel to the combustion section. Since the combustion portion is supplied and re-ignited, in addition to the operation and effect of the invention according to claim 8, it is possible to start the reformer by using only the reforming fuel, thus simplifying the device. be able to.

  In the invention according to claim 9 configured as described above, in the invention according to claim 2, the first re-ignition means raises the temperature of the reformed water supplied to the reforming section to a predetermined temperature for steam. In the case where the temperature of the reforming section is lowered to a third predetermined temperature between the first predetermined temperature and the second predetermined temperature before the reforming, the temperature of the reforming water supplied to the reforming section is the predetermined temperature for steam. When the temperature is raised to, the supply of combustion fuel to the combustion section is started and the combustion section is reignited. As a result, the temperature of the reforming section is always lowered further than the third predetermined temperature and the combustion section is re-ignited, so that the reforming section due to overcombustion when the combustible gas supplied to the combustion section is a reformed gas. Thermal damage can be further suppressed.

  In the invention according to claim 10 configured as described above, in the invention according to claim 9, the temperature of the reforming portion is raised to the first predetermined temperature after re-ignition with the fuel for combustion by the first re-ignition means. When the temperature of the reforming water supplied to the reforming unit is equal to or higher than the predetermined temperature for steam at the time when the temperature of the reforming unit is raised to the first predetermined temperature, A second fire extinguishing means for stopping only the supply of the fuel for combustion, and then, when the temperature of the reforming section drops to the third predetermined temperature, the second extinguishing means supplies the reforming fuel to the reforming section and reignites the combustion section. In addition to the operation and effect of the invention according to claim 9, in addition to the action and effect of the invention according to claim 9, the reforming fuel is introduced in a state where the temperature of the reforming section is kept high, and coking of the reforming section is performed. It can be surely prevented.

  Hereinafter, an embodiment of a fuel cell system to which a reformer according to the present invention is applied will be described. FIG. 1 is a schematic diagram showing an outline of this fuel cell system. This fuel cell system includes a fuel cell 10 and a reformer 20 that generates a reformed gas containing hydrogen gas necessary for the fuel cell 10.

  The fuel cell 10 includes a fuel electrode 11, an air electrode 12 that is an oxidant electrode, and an electrolyte 13 interposed between the electrodes 11 and 12, and supplies the reformed gas supplied to the fuel electrode 11 and the air electrode 12. Electric power is generated using air (cathode air), which is the oxidant gas. Note that air-enriched gas may be supplied instead of air.

  The reformer 20 steam reforms the reforming fuel and supplies a hydrogen-rich reformed gas to the fuel cell 10. The reformer 20 includes a reforming unit 21, a cooling unit 22, a carbon monoxide shift reaction unit (hereinafter referred to as “carbon reforming unit”). , A CO shift unit) 23, a carbon monoxide selective oxidation reaction unit (hereinafter referred to as a CO selective oxidation unit) 24, a combustion unit 25, and an evaporation unit 26. Examples of the reforming fuel include natural gas, gas fuel for reforming such as LPG, and liquid fuel for reforming such as kerosene, gasoline, and methanol. In the present embodiment, description will be made on natural gas.

  The reforming unit 21 generates and derives a reformed gas from a mixed gas that is a reforming raw material in which reforming water is mixed with the reforming fuel. The reforming portion 21 is formed in a bottomed cylindrical shape, and includes an annular folded channel 21a extending along the axis in the annular cylindrical portion. The reforming part 21 is made of stainless steel.

  The return channel 21 a of the reforming unit 21 is filled with a catalyst 21 b (for example, a Ru or Ni-based catalyst) and introduced from the reforming fuel introduced from the cooling unit 22 and the steam supply pipe 51. The gas mixture with the steam reacts and is reformed by the catalyst 21b to generate hydrogen gas and carbon monoxide gas (so-called steam reforming reaction). At the same time, a so-called carbon monoxide shift reaction occurs in which carbon monoxide generated in the steam reforming reaction reacts with steam to transform into hydrogen gas and carbon dioxide. These generated gases (so-called reformed gas) are led to a cooling unit (heat exchange unit) 22. The steam reforming reaction is an endothermic reaction, and the carbon monoxide shift reaction is an exothermic reaction. The activation temperature range of the catalyst 21b of the reforming unit 21 is 400 ° C to 800 ° C.

  Further, a temperature sensor 21 c that measures the temperature in the reforming unit 21, for example, the temperature (TR) in the vicinity of the wall between the reforming unit 21 is provided in the reforming unit 21. The detection result of the temperature sensor 21 c is transmitted to the control device 30.

  The cooling unit 22 is a heat exchanger (heat exchange unit) in which heat exchange is performed between the reformed gas derived from the reforming unit 21 and a mixed gas of reforming fuel and reformed water (steam). The temperature of the reformed gas having a high temperature is lowered by the mixed gas having a low temperature and led to the CO shift unit 23, and the temperature of the mixed gas is raised by the reformed gas and led to the reforming unit 21. Yes.

  Specifically, a fuel supply pipe 41 connected to a fuel supply source (not shown) (for example, a city gas pipe) is connected to the cooling unit 22. The fuel supply pipe 41 is provided with a reforming fuel pump 42 and a reforming fuel valve 43 in order from the upstream. The reforming fuel valve 43 opens and closes the fuel supply pipe 41. The reforming fuel pump 42 is reforming fuel supply means for supplying reforming fuel and adjusting the supply amount. In addition, a steam supply pipe 51 connected to the evaporation section 26 is connected between the reforming fuel valve 43 of the fuel supply pipe 41 and the cooling section 22. The steam supplied from the evaporation unit 26 is mixed with the reforming fuel, and the mixed gas is supplied to the reforming unit 21 through the cooling unit 22.

  The CO shift unit 23 is a unit that reduces carbon monoxide in the reformed gas supplied from the reforming unit 21 through the cooling unit 22, that is, a carbon monoxide reducing unit. The CO shift unit 23 includes a folded channel 23a extending along the vertical direction. The return channel 23a is filled with a catalyst 23b (for example, a Cu—Zn-based catalyst). In the CO shift unit 23, a so-called carbon monoxide shift reaction in which carbon monoxide and water vapor contained in the reformed gas introduced from the cooling unit 22 react with the catalyst 23b to be converted into hydrogen gas and carbon dioxide gas. Has occurred. This carbon monoxide shift reaction is an exothermic reaction.

  In the CO shift unit 23, a temperature sensor 23c that measures the temperature in the CO shift unit 23 is provided. The detection result of the temperature sensor 23 c is transmitted to the control device 30.

  The CO selective oxidation unit 24 further reduces the carbon monoxide in the reformed gas supplied from the CO shift unit 23 and supplies it to the fuel cell 10, that is, a carbon monoxide reduction unit. The CO selective oxidation unit 24 is formed in a cylindrical shape, and is provided so as to cover the outer peripheral wall of the evaporation unit 26. The CO selective oxidation unit 24 is filled with a catalyst 24a (for example, a Ru or Pt catalyst).

  In the CO selective oxidation unit 24, a temperature sensor 24b for measuring the temperature in the CO selective oxidation unit 24 is provided. The detection result of the temperature sensor 24 b is transmitted to the control device 30.

  A connecting pipe 89 connected to the CO shift section 23 and a reformed gas supply pipe 71 connected to the fuel electrode 11 of the fuel cell 10 are connected to the lower and upper side walls of the CO selective oxidation section 24, respectively. ing. An oxidation air supply pipe 61 is connected to the connection pipe 89. As a result, the reformed gas from the CO shift unit 23 and the oxidizing air from the atmosphere are introduced into the CO selective oxidation unit 24. The oxidizing air supply pipe 61 is provided with an oxidizing air pump 62 and an oxidizing air valve 63 in order from the upstream. The oxidizing air pump 62 supplies oxidizing air and adjusts the supply amount. The oxidation air valve 63 opens and closes the oxidation air supply pipe 61.

  Therefore, carbon monoxide in the reformed gas introduced into the CO selective oxidation unit 24 reacts (oxidizes) with oxygen in the oxidizing air to become carbon dioxide. This reaction is an exothermic reaction and is promoted by the catalyst 24a. Thereby, the reformed gas is derived by further reducing the carbon monoxide concentration (10 ppm or less) by the oxidation reaction, and is supplied to the fuel electrode 11 of the fuel cell 10.

  The combustion unit 25 burns at least one of the combustion fuel supplied by the combustion fuel pump 45 and the reformed gas supplied from the reforming unit 21 by the combustion air supplied by the combustion air pump 65. Then, the reforming part 21 is heated by the combustion gas. The combustion unit 25 generates combustion gas for heating the reforming unit 21 and supplying heat necessary for the steam reforming reaction, and a lower end portion is inserted into the inner peripheral wall of the reforming unit 21. It is arranged with a space.

  A combustion fuel supply pipe 44 connected to a fuel supply source (not shown) (for example, a city gas pipe) is connected to the combustion unit 25, and an off gas supply pipe 72 having one end connected to the outlet of the fuel electrode 11. Are connected at the other end. Basically, the fuel for combustion is supplied to the combustion unit 25 at the beginning of the start of the fuel cell 10, and the reformed gas from the CO selective oxidation unit 24 burns without passing through the fuel cell 10 during the start-up operation of the fuel cell 10. The anode off gas (reformed gas containing hydrogen unused in the fuel electrode 11) discharged from the fuel cell 10 during the steady operation of the fuel cell 10 is supplied to the combustion unit 25. It has become. In addition, the shortage of reformed gas and off-gas is supplemented with combustion fuel.

  Further, a combustion air supply pipe 64 is connected to the combustion unit 25, and combustion air for burning (oxidizing) a combustible gas such as a combustion fuel, anode off gas, and reformed gas is supplied from the atmosphere. It has become so.

  The combustion fuel supply pipe 44 is provided with a combustion fuel pump 45 and a combustion fuel valve 46 in order from the upstream. The combustion fuel pump 45 is combustion fuel supply means for supplying combustion fuel and adjusting the supply amount. The combustion fuel valve 46 opens and closes the combustion fuel supply pipe 44. The combustion air supply pipe 64 is provided with a combustion air pump 65 and a combustion air valve 66 in order from the upstream. The combustion air pump 65 is combustion oxidant gas supply means for supplying combustion air as combustion oxidant gas and adjusting the supply amount. The combustion air valve 66 opens and closes the combustion air supply pipe 64.

  When the combustion unit 25 configured as described above is ignited, the supplied combustion fuel, reformed gas or anode off-gas is combusted by the combustion air to generate high-temperature combustion gas. The combustion gas flows through the combustion gas passage 27 and is exhausted as combustion exhaust gas through the exhaust pipe 81. Thus, the combustion gas heats the reforming unit 21 and the evaporation unit 26 in this order. The combustion gas flow path 27 is disposed in contact with the inner peripheral wall of the reforming section 21 and is folded and disposed between the outer peripheral wall of the reforming section 21 and the heat insulating section 28 and folded. In other words, the flow path is disposed in contact between the heat insulating portion 28 and the evaporation portion 26.

  The evaporation unit 26 evaporates the reformed water to generate water vapor, and supplies the water vapor to the reforming unit 21 via the cooling unit 22. The evaporator 26 is formed in a cylindrical shape so as to cover and contact the outer peripheral wall of the combustion gas passage 27.

  A water supply pipe 52 connected to a reforming water tank (not shown) is connected to a lower portion (for example, a lower portion of the side wall surface and a bottom surface) of the evaporation section 26. A water vapor supply pipe 51 is connected to the upper part (for example, the upper part of the side wall surface) of the evaporation unit 26. The reformed water introduced from the reformed water tank is heated by the heat from the combustion gas and the heat from the CO selective oxidation unit 24 in the course of flowing through the evaporation unit 26 to become water vapor and the water vapor supply pipe 51. And, it is led out to the reforming unit 21 through the cooling unit 22. The water supply pipe 52 is provided with a reforming water pump 53 and a reforming water valve 54 in order from the upstream. The reforming water pump 53 supplies reforming water to the evaporation unit 26 and adjusts the reforming water supply amount. The reforming water valve 54 opens and closes the water supply pipe 52.

  The evaporation unit 26 is provided with a temperature sensor 26 a that detects the temperature (TS) of water vapor in the evaporation unit 26. The detection result of the temperature sensor 26 a is transmitted to the control device 30. If the temperature of the water vapor can be detected, for example, the temperature sensor 26 a may be provided in the vicinity of the inlet of the cooling unit 22 or in the water vapor supply pipe 51 between the evaporation unit 26 and the cooling unit 22. This steam temperature TS is the temperature of the reforming water supplied to the reforming unit 21.

  A CO selective oxidation unit 24 is connected to the inlet of the fuel electrode 11 of the fuel cell 10 via a reformed gas supply pipe 71, and the combustion unit 25 is connected to the outlet of the fuel electrode 11 via an offgas supply pipe 72. Is connected. The bypass pipe 73 bypasses the fuel cell 10 and directly connects the reformed gas supply pipe 71 and the offgas supply pipe 72. The reformed gas supply pipe 71 is provided with a first reformed gas valve 74 between the branch point of the bypass pipe 73 and the fuel cell 10. The off gas supply pipe 72 is provided with an off gas valve 75 between the junction with the bypass pipe 73 and the fuel cell 10. A second reformed gas valve 76 is provided in the bypass pipe 73.

  During the start-up operation, the first reformed gas valve 74 and the offgas valve 75 are closed to avoid the supply of the reformed gas having a high carbon monoxide concentration from the reformer 20 to the fuel cell 10. During the steady operation (power generation operation), the first reformed gas valve 74 and the offgas valve 75 are opened to supply the reformed gas from the reformer 20 to the fuel cell 10 during the steady operation (power generation operation). Is closed.

  A cathode air supply pipe 67 is connected to the inlet of the air electrode 12 of the fuel cell 10, and an exhaust pipe 82 is connected to the outlet of the air electrode 12. Air is supplied to the air electrode 12, and off-gas is exhausted. The cathode air supply pipe 67 is provided with a cathode air pump 68 and a cathode air valve 69 in order from the upstream. The cathode air pump 68 supplies cathode air and adjusts the supply amount. The cathode air valve 69 opens and closes the cathode air supply pipe 67.

  The fuel cell system also includes a control device 30. The control device 30 includes the temperature sensors 21c, 23c, 24b, and 26a, the pumps 42, 45, 53, 62, 65, and 68, and the valves 43. , 46, 54, 63, 66, 69, 74, 75, 76 and the combustion section 25 are connected (see FIG. 3). The control device 30 includes a microcomputer (not shown), and the microcomputer includes an input / output interface, a CPU, a RAM, and a ROM (all not shown) connected through a bus. The CPU, based on the temperature from the temperature sensors 21c, 23c, 24b, 26a, each pump 42, 45, 53, 62, 65, 68, each valve 43, 46, 54, 63, 66, 69, 74, 75. , 76 and the combustion section 25 are controlled to start up the reformer. The RAM temporarily stores variables necessary for executing the program, and the ROM stores the program.

  Next, a first embodiment of the operation of the fuel cell system described above will be described with reference to FIGS. When a start switch (not shown) is turned on, control device 30 starts a start operation (step 100). First, the control device 30 starts combustion of the combustion unit 25 at the time of activation (combustion start means). Specifically, the control device 30 opens the combustion air valve 66 and drives the combustion air pump 65 to supply the combustion air to the combustion section 25 at a preset specified flow rate C1 (step 102). .

  Then, the control device 30 opens the combustion fuel valve 46 and the second reformed gas valve 76 with the reforming fuel valve 43, the first reformed gas valve 74, and the offgas valve 75 closed, and turns the combustion fuel pump 45 on. Driven to supply combustion fuel to the combustion section 25 at a predetermined flow rate B1 set in advance (step 104).

  Then, the control device 30 energizes a built-in igniter (not shown) in the combustion unit 25 (step 106; a glow plug may be used instead of the igniter). Thereby, the combustion part 25 ignites. Further, the control device 30 stops the igniter energization after a predetermined time has elapsed from the time when the ignition is detected or the igniter energization is performed. The ignition may be not only ignition by an igniter or glow plug, but also catalyst ignition.

  When combustion of the combustion fuel is started in this way, when the combustion gas passes through the combustion gas flow path 27, the reforming unit 21 and the evaporation unit 26 are heated in this order by the combustion gas to raise the temperature. .

  When the evaporation unit 26 is heated to a predetermined temperature or higher, the control device 30 opens the reforming water valve 54 and drives the reforming water pump 53 to supply the reforming water to the evaporation unit 26 (step 108). ). Note that the supply of reforming water may be started at the same time as the start of supply of combustion fuel regardless of the temperature of the evaporator 26, or may be after a predetermined time has elapsed.

  When the reforming unit 21 is heated and the temperature of the reforming unit 21 is increased to a first predetermined temperature TR1 (for example, 600 ° C.) after the combustion of the combustion unit 25 is started, the control device 30 is used for combustion to the combustion unit 25. Only the fuel supply is stopped and the combustion section 25 is extinguished (first extinguishing means). Specifically, if the start-up is started from the normal temperature state, the steam temperature does not reach the steam predetermined temperature TS1 (for example, 80 ° C.) even if the temperature of the reforming unit 21 is raised to the first predetermined temperature TR1. The control device 30 makes a determination of “NO” or “YES” in steps 110 and 112, stops driving the combustion fuel pump 45, and stops the supply of the combustion fuel to the combustion section 25 (step 114). ). The first predetermined temperature TR1 is preferably set to the upper temperature of the activation temperature range of the catalyst 21b of the reforming unit 21.

  Thereby, although the supply of combustion fuel is stopped and the combustion section 25 is extinguished, the supply of combustion air to the combustion section 25 is continued, so the combustion air flowing through the combustion gas flow path is reformed. The combustion air, which has been heated to a high temperature by taking the heat of the part 21, raises the temperature of the evaporation part 26.

  If “YES” in step 110, that is, if the water vapor temperature has reached the predetermined steam temperature TS 1 regardless of whether or not the temperature TR of the reforming section has reached the first predetermined temperature TR 1, Start supplying fuel.

  After extinguishing the combustion unit 25, the temperature of the reforming unit 21 is lower than the first predetermined temperature TR1 and the second predetermined temperature TR2 (for example, 400 ° C.) before the temperature of the steam rises to the predetermined temperature TS1 for steam. When the temperature falls to the level, the control device 30 resumes the supply of the fuel for combustion to the combustion unit 25 and reignites the combustion unit (first reignition means). Specifically, the control device 30 repeatedly executes “NO” determination at step 116 until the temperature of the reforming unit 21 drops to the second predetermined temperature TR2 (for example, 400 ° C.). Then, when the temperature of the reforming unit 21 falls to the second predetermined temperature TR2, the control device 30 determines “YES” in step 116, restarts the driving of the combustion fuel pump 45 (step 104), and the combustion unit 25 is ignited (step 106), and reformed water is supplied (step 108). It is desirable that the second predetermined temperature TR2 is set to be lower than a temperature at which the casing of the reforming portion 21 is susceptible to intergranular corrosion. This is because there is a region where the intergranular corrosion is likely to occur, and this region is passed quickly.

  The re-ignition of the combustion section 25 with the combustion fuel raises the temperature of the reforming section 21 and the evaporation section 26, and the water vapor temperature reaches the predetermined temperature for steam before the temperature of the reforming section 21 reaches the first predetermined temperature TR1. When the temperature TS1 is reached, the control device 30 determines “YES” in step 110, and starts supplying the reforming fuel (step 118). That is, the control device 30 opens the reforming fuel valve 43 and drives the reforming fuel pump 42 to supply reforming fuel to the reforming unit 21 at a preset specified flow rate A1.

  When charging of the reforming fuel is started in this way, the reforming unit 21 generates the reformed gas by the above-described steam reforming reaction and carbon monoxide shift reaction, and the CO selective oxidizing unit 24 reforms. Although the gas is derived, since there is still a large amount of carbon monoxide, the fuel cell 10 is bypassed and supplied to the combustion unit 25.

  When the temperature of each predetermined part (the reforming unit 21, the CO shift unit 23, and the CO selective oxidation unit 24) of the reforming device 20 reaches a predetermined temperature or more (step 120), the control device 30 starts the startup operation. (Step 122), the reformed gas from the CO selective oxidation unit 24 is supplied to the fuel cell 10 and the power generation of the fuel cell 10 is started. That is, the power generation operation (steady operation) is started. The start of power generation may be determined when the carbon monoxide concentration in the reformed gas becomes lower than a predetermined value.

  As is apparent from the above description, in this first embodiment, the combustion start means (steps 102 to 108) supplies combustion fuel and combustion oxidant gas to start combustion when the reformer is activated. When the temperature of the reforming unit 21 is raised to the first predetermined temperature TR1 after the start of combustion of the combustion unit, the first fire extinguishing means (step 114) ignites the unit 25 and supplies reforming water to the evaporation unit 26. Then, the supply of the combustion fuel to the combustion unit 25 is stopped, the combustion unit 25 is extinguished, and the combustion oxidant gas supply means (step 102) supplies the combustion oxidant gas while the combustion unit 25 is extinguished. . Thereby, the temperature of the reforming part 21 can be reduced more quickly, and re-ignition becomes possible. Moreover, the temperature at which the casing of the reformer 20 is likely to corrode can be avoided.

  Further, after the first reignition means (steps 116, 104, 106) extinguishes the combustion section 25 by the first fire extinguishing means, the temperature of the reforming section 21 and the temperature of the steam (reformed water supplied to the reforming section). The combustion part or the reforming fuel is supplied on the basis of at least one of the above temperature) to reignite the combustion part. As a result, after the temperature of the reforming unit 21 is raised to the first predetermined temperature TR1, which is a relatively high temperature, until the fire is temporarily extinguished and reignited, the heat of the reforming unit 21 is passed through the combustion air. The water vapor can be heated by being transmitted to the evaporation section 26 located downstream of 21. Therefore, the number of repetitions of ignition / extinguishing of the combustion unit 25 can be reduced, the durability of the combustion unit 25 and the reforming unit 21 can be maintained high, and the reformer 20 can be warmed up.

  In addition, since the first predetermined temperature TR1 is set to the upper temperature of the activation temperature range of the catalyst 21b of the reforming unit 21, the ignition / ignition of the combustion unit 25 is performed without damaging the catalyst 21b of the reforming unit 21. The reforming apparatus 20 can be warmed up by reducing the number of times of extinguishing and maintaining the durability of the combustion section 24 and the reforming section 21 high.

  The first re-ignition means (steps 116, 104, 106) is configured so that the temperature of the reforming part 21 is not increased after the temperature of the steam rises to the predetermined steam temperature TS1 after the combustion part 25 is extinguished by the first fire extinguishing means. When the temperature drops to the second predetermined temperature TR2 lower than the first predetermined temperature TR1, the supply of the combustion fuel to the combustion unit 25 is resumed and the combustion unit 25 is re-ignited, so that the temperature of the reforming unit 21 is decreased more than necessary. Without repetition, the number of repetitions of ignition / extinguishing of the combustion section 25 can be reduced.

  Further, since the second predetermined temperature TR2 is set to be higher than the temperature at which the casing of the reforming section 21 is likely to undergo intergranular corrosion, the combustion section 25 is not damaged without damaging the casing of the reforming section 21. Thus, the reforming device 20 can be warmed up by reducing the number of repetitions of ignition and extinguishing, maintaining the durability of the combustion section 25 and the reforming section 21 high.

  Next, a second embodiment of the operation of the fuel cell system described above will be described with reference to FIGS. In the second embodiment, in the first embodiment described above, after the combustion in the combustion section 25 is started, the steam temperature TS becomes the steam before the temperature TR of the reforming section 21 reaches the first predetermined temperature TR1. When the predetermined temperature TS1 is reached, the supply of combustion fuel is stopped, the combustion section 25 is extinguished, and then reignited with the combustion fuel.

  In this case, if it is determined that the temperature of the water vapor has reached the predetermined temperature TS1 for water vapor after starting the combustion of the combustion unit 25, if the determination is the first time, only supply of the fuel for combustion to the combustion unit 25 is provided. If the determination is after the second time, switching means (step 130) for starting the supply of the reforming fuel to the reforming unit 21 without stopping the supply of the combustion fuel to the combustion unit 25 is provided. What is necessary is just to prepare further.

  Step 130 is provided between Step 110 and Step 118. It is determined whether or not the determination that the temperature of the water vapor has reached the predetermined temperature TS1 for water vapor is the second time or later. If the determination is the first time, control device 30 determines “NO” and stops the supply of combustion fuel (step 114). Thereafter, the control device 30 executes the processing from step 116 onward.

  On the other hand, if the determination is second or later, control device 30 determines “YES” and starts supplying reforming fuel (step 118). Thereafter, the control device 30 executes the processing after step 120.

  According to such control, for example, as shown in FIG. 6, the control device 30 starts combustion in the combustion unit 25 and before the temperature of the reforming unit 21 reaches the first predetermined temperature TR1. When the water vapor temperature reaches the predetermined temperature TS1 for water vapor, the combustion section 25 is extinguished by stopping the supply of the fuel for combustion, and when the temperature of the reforming section 21 drops and reaches the second predetermined temperature TR2, the combustion section 25 is reignited with fuel for combustion. If the water vapor temperature has risen to the predetermined temperature TS1 for steam at the time of this re-ignition, the second determination is made that the temperature of the water vapor has reached the predetermined temperature TS1 for water vapor, and combustion of the combustion section 25 is performed. While being maintained, supply of reforming fuel to the reforming unit 21 is started. Therefore, for example, when the reformer 20 is still warm, such as when operation is started shortly after the fuel cell system is stopped, the warm-up time can be shortened. If the water vapor temperature has not been raised to the predetermined temperature TS1 for water vapor at the time of reignition, the same processing as described above is performed.

  Next, a third embodiment (an embodiment corresponding to claim 5) of the operation of the fuel cell system described above will be described with reference to FIGS. In the third embodiment, after the combustion in the combustion section 25 is started in the first embodiment described above, the supply of combustion fuel is stopped when the temperature of the reforming section 21 reaches the first predetermined temperature TR1. Thus, when the temperature of the reforming unit 21 is lowered and reaches the second predetermined temperature TR2, the water vapor temperature is increased to the predetermined temperature TS1 for steam before the temperature of the reforming unit 21 is lowered. When the predetermined temperature TS1 is reached, the combustion section 25 is re-ignited with the combustion fuel, and supply of the reforming fuel to the reforming section 21 is started.

  In this case, step 140 may be provided between step 114 and step 116. Step 140 determines whether or not the water vapor temperature is equal to or higher than a predetermined temperature TS1 for water vapor.

  In step 140, control device 30 determines “YES” if the water vapor temperature is equal to or higher than predetermined temperature TS1 for water vapor, and reignites combustion unit 25 with the fuel for combustion (steps 104 and 106). Thereafter, the control device 30 executes the processing after step 108. On the other hand, in step 140, control device 30 determines “NO” if the water vapor temperature is lower than predetermined temperature TS1 for water vapor, and determines whether or not the reforming section temperature has decreased to second predetermined temperature TR2. (Step 116). Then, the control apparatus 30 performs the process according to the determination result as mentioned above.

  According to such control, as shown in FIG. 8, for example, the control device 30 starts combustion for the combustion when the temperature of the reforming unit 21 reaches the first predetermined temperature TR1 after starting combustion in the combustion unit 25. After extinguishing the combustion section 25 by stopping the supply of fuel, the temperature of the steam is lowered to the predetermined temperature TS1 for steam before the temperature of the reforming section 21 falls to the second predetermined temperature TR2 lower than the first predetermined temperature TR1. When the temperature is raised to 1, the supply of combustion fuel to the combustion unit 25 is resumed and the combustion unit 25 is re-ignited, so that the start-up time can be shortened without unnecessarily lowering the temperature of the reforming unit 21.

  Next, a fourth embodiment (an embodiment corresponding to claims 7 and 9) of the operation of the above-described fuel cell system will be described with reference to FIGS. In the fourth embodiment, the third predetermined temperature TR3, which is a temperature between the first predetermined temperature TR1 and the second predetermined temperature TR2, is set with respect to the reforming portion temperature in the first embodiment described above, and the modification is made. The start-up operation of the reformer 20 is executed in consideration of the relationship between the mass part temperature and the third predetermined temperature TR3.

  In this case, step 142 may be provided between step 114 and step 116 in addition to step 140. Step 140 determines whether or not the water vapor temperature is equal to or higher than a predetermined temperature TS1 for water vapor. Step 142 determines whether or not the temperature of the reforming unit 21 is equal to or lower than a third predetermined temperature TR3.

  When the water vapor temperature rises to the steam predetermined temperature TS1 before the temperature of the reforming unit 21 falls to the third predetermined temperature TR3, the control device 30 lowers the temperature of the reforming unit 21 to the third predetermined temperature TR3. Then, since the water vapor temperature is equal to or higher than the predetermined water vapor temperature TS1, “YES” is determined in steps 140 and 142, respectively, and the combustion section 25 is reignited with the fuel for combustion (steps 104 and 106). Thereafter, the control device 30 executes the processing after step 108.

  When the water vapor temperature exceeds the predetermined temperature TS1 for water vapor, the control device 30 determines “YES” in step 140, and thereafter the control device until the temperature of the reforming unit 21 falls to the third predetermined temperature TR3. 30 continues to determine “NO” in step 142.

  According to such control, as shown in FIG. 10, when the temperature of the reforming unit 21 reaches the first predetermined temperature TR1 after starting the combustion in the combustion unit 25, the control device 30 is a fuel for combustion. When the temperature of the steam rises to the predetermined temperature TS1 for steam before the temperature of the reforming part 21 falls to the third predetermined temperature TR3 after the combustion part 25 is extinguished by stopping the supply of the reforming part Waiting for the temperature of 21 to drop to the third predetermined temperature TR3, the supply of the combustion fuel to the combustion section 25 is resumed, the combustion section 25 is reignited, and the supply of the reforming fuel to the reforming section 21 is started. To do. As a result, the temperature of the reforming unit 21 is always lowered to the third predetermined temperature TR3 and the combustion unit 25 is re-ignited, so that the combustible gas supplied to the combustion unit 25 has a larger amount of heat than the combustion fuel. Thermal damage of the reforming part 21 due to overcombustion in the case of gas can be suppressed.

  In addition, when the temperature of the reforming unit 21 falls to the third predetermined temperature TR3 before the temperature of the steam rises to the predetermined temperature TS1 for steam, the control device 30 first sets the temperature of the reforming unit 21 to Although the temperature is lowered to the third predetermined temperature TR3, the water vapor temperature has not been raised to the predetermined temperature TS1 for water vapor, so “NO” is determined in steps 140 and 116 until the water vapor temperature rises to the predetermined temperature TS1 for water vapor. Keep doing. When the water vapor temperature rises to the predetermined temperature TS1 for water vapor, the control device 30 determines “YES” in steps 140 and 142, respectively, and reignites the combustion section 25 with the fuel for combustion (steps 104 and 106). . Thereafter, the control device 30 executes the processing after step 108.

  According to such control, as shown in FIG. 11, when the temperature of the reforming unit 21 reaches the first predetermined temperature TR1 after starting the combustion in the combustion unit 25, the control device 30 is a combustion fuel. In the case where the temperature of the reforming section 21 is lowered to the third predetermined temperature TR3 after the combustion section 25 is extinguished by stopping the supply of the steam and before the temperature of the steam rises to the predetermined temperature TS1 for steam, Waiting for the temperature of the water to rise to a predetermined temperature TS1 for steam, supply of combustion fuel to the combustion section 25 is started, the combustion section 25 is reignited, and supply of reforming fuel to the reforming section 21 is started. To do. As a result, the temperature of the reforming unit 21 is always lowered further than the third predetermined temperature and the combustion unit 25 is re-ignited, so that the combustible gas supplied to the combustion unit 25 has a larger amount of heat than the combustion fuel. Thermal damage of the reforming part 21 due to overcombustion in the case of gas can be suppressed. Further, water vapor can be reliably supplied to the reforming unit 21.

  Next, a fifth embodiment (embodiment corresponding to claims 4 and 6) of the operation of the above-described fuel cell system will be described with reference to FIGS. In the fifth embodiment, in the third embodiment described above, when the control device 30 starts combustion in the combustion section 25 and the temperature of the reforming section 21 reaches the first predetermined temperature TR1, the fuel for combustion is used. After the combustion section 25 is extinguished by stopping the supply of the steam, the temperature of the steam reaches the predetermined steam temperature TS1 before the temperature of the reforming section 21 falls to the second predetermined temperature TR2 lower than the first predetermined temperature TR1. When the temperature rises, instead of restarting the supply of the combustion fuel to the combustion unit 25 and reigniting the combustion unit 25, the reforming fuel (fuel) is generated by supplying the reforming fuel to the reforming unit 21. The combustion part 25 is reignited by not passing through the battery 10).

  In this case, step 110 is deleted from the flowchart shown in FIG. 7, and if “YES” is determined in step 140, the program proceeds to step 118 instead of returning to step 104, and a step between step 118 and step 120 is performed. 150 is added. Step 150 ignites the combustion section 25 as in Step 106.

  According to such control, as shown in FIG. 13, the control device 30 starts combustion in the combustion unit 25 and then the combustion fuel when the temperature of the reforming unit 21 reaches the first predetermined temperature TR1. After the combustion section 25 is extinguished by stopping the supply of the steam, the temperature of the steam reaches the predetermined steam temperature TS1 before the temperature of the reforming section 21 falls to the second predetermined temperature TR2 lower than the first predetermined temperature TR1. When the temperature rises, reforming fuel is supplied to the reforming unit 21, and the combustion unit 25 is reignited with the reformed gas (which does not pass through the fuel cell 10) generated as a result. As a result, the reforming device 20 can be started only by using the reforming fuel, so that the combustion fuel supply pipe 44 for supplying the combustion fuel to the combustion section 25, the combustion fuel pump 45, Since the combustion fuel valve 46 can be eliminated, the apparatus can be simplified. However, one valve for supplying fuel from the reforming fuel pump 42 to the combustion unit 25 (for switching between the reforming unit 21 and the combustion unit 25) is added.

  Further, as shown in FIG. 14, after starting combustion in the combustion unit 25, the control device 30 stops supplying the combustion fuel when the temperature of the reforming unit 21 reaches the first predetermined temperature TR <b> 1. When the temperature of the reforming unit 21 falls to the second predetermined temperature TR2 after the combustion unit 25 is extinguished and before the steam temperature rises to the predetermined temperature TS1 for steam, the temperature of the reforming unit 21 is the second temperature. When the temperature falls to the predetermined temperature TR2, “YES” is determined in Step 116, and the combustion section 25 is reignited with the fuel for combustion (Steps 104 and 106). After the re-ignition, the control device 30 performs a step when the temperature of the steam is equal to or higher than the predetermined temperature Ts1 for water vapor before the temperature of the reforming unit 21 is raised again to the first predetermined temperature TR1. It is determined as “YES” at 112 and only the supply of the fuel for combustion to the combustion unit 25 is stopped (step 114, second extinguishing means). Thereafter, it is determined as “YES” at step 140 and the reforming unit 21 is determined. The reforming fuel is supplied to the fuel and the combustion section 25 is re-ignited with the reformed gas (which does not pass through the fuel cell 10) generated as a result (step 150, second re-ignition means). As a result, the reformed fuel can be introduced while the temperature of the reforming unit 21 is kept high, and coking of the reforming unit 21 can be suppressed.

  Next, a sixth embodiment (an embodiment corresponding to claims 8 and 10) of the operation of the above-described fuel cell system will be described with reference to FIGS. In the sixth embodiment, in the third embodiment described above, after the combustion section 25 is extinguished by the first fire extinguishing means, the supply of the fuel for combustion to the combustion section 25 is resumed and the combustion section 25 is reignited. In addition, the fuel for reforming is supplied to the reforming unit 21, and the combustion unit 25 is re-ignited with the reformed gas generated as a result (not passing through the fuel cell 10).

  In this case, step 110 is deleted from the flowchart shown in FIG. 9, and if “YES” is determined in step 142, the program proceeds to step 118 instead of returning to step 104, and the step between step 118 and step 120 is performed. 150 is added. Step 150 ignites the combustion section 25 as in Step 106.

  According to such control, as shown in FIG. 16, when the temperature of the reforming unit 21 reaches the first predetermined temperature TR1 after starting the combustion in the combustion unit 25, the control device 30 is a combustion fuel. When the temperature of the steam rises to the predetermined temperature TS1 for steam before the temperature of the reforming part 21 falls to the third predetermined temperature TR3 after the combustion part 25 is extinguished by stopping the supply of the reforming part 21 The reforming fuel is supplied to the combustion chamber 25, and the combustion section 25 is re-ignited with the reformed gas (not passing through the fuel cell 10) generated as a result. As a result, the temperature of the reforming unit 21 is surely lowered to the third predetermined temperature TR3 and the combustion unit 25 is re-ignited. Therefore, the reforming due to overcombustion when the combustible gas supplied to the combustion unit 25 is the reformed gas. Thermal damage of the mass portion 21 can be suppressed. In addition, since the reformer 20 can be started only by using the reforming fuel, the combustion fuel supply pipe 44 for supplying the combustion fuel to the combustion section 25, the combustion fuel pump 45. Since the combustion fuel valve 46 can be eliminated, the apparatus can be simplified.

  Further, as shown in FIG. 17, after starting the combustion in the combustion unit 25, the control device 30 stops supplying the combustion fuel when the temperature of the reforming unit 21 reaches the first predetermined temperature TR <b> 1. When the temperature of the reforming unit 21 falls to the second predetermined temperature TR2 after the combustion unit 25 is extinguished and before the steam temperature rises to the predetermined temperature TS1 for steam, the temperature of the reforming unit 21 is the second temperature. When the temperature falls to the predetermined temperature TR2, “YES” is determined in Step 116, and the combustion section 25 is reignited with the fuel for combustion (Steps 104 and 106). After this re-ignition, when the temperature of the reforming unit 21 is raised again to the first predetermined temperature TR1, the control device 30 performs a step when the temperature of the steam is equal to or higher than the predetermined temperature Ts1 for steam. It is determined as “YES” at 112, and only the supply of the fuel for combustion to the combustion section is stopped when the temperature of the reforming section 21 rises to the first predetermined temperature (step 114, second extinguishing means). As a result, the temperature of the reforming unit 21 is decreased, but the steam temperature is equal to or higher than the predetermined temperature Ts1 for steam. Until the temperature is lowered to “NO”, it is determined as “NO” in step 142. When the temperature of the reforming unit 21 falls to the third predetermined temperature TR3, the control device 30 determines “YES” in step 142, supplies the reforming fuel to the reforming unit 21, and is generated as a result. The combustion section 25 is re-ignited with the reformed gas (which does not pass through the fuel cell 10) (step 150, second re-ignition means).

  Therefore, since the temperature of the reforming unit 21 is always further lowered from the third predetermined temperature TR3 and the combustion unit 25 is reignited, the reforming due to overcombustion when the combustible gas supplied to the combustion unit 25 is the reformed gas. The thermal damage of the mass portion 21 can be further suppressed. Further, the reformed fuel can be introduced while the temperature of the reforming section 21 is kept high, and the coking of the reforming section 21 can be reliably prevented.

  Next, a seventh embodiment of the operation of the fuel cell system described above will be described with reference to FIG. In the seventh embodiment, the start-up operation of the reformer 20 is started, and before the temperature of the reforming unit 21 rises to the first predetermined temperature TR1, the steam temperature rises to the steam predetermined temperature TS1. Control of the case.

  In this case, the processing of Step 110 may be provided between Step 108 and Step 112 in the flowchart shown in FIG. Step 110 is a process for determining whether or not the water vapor temperature is equal to or higher than a predetermined water vapor temperature TS1. If "YES" is determined in step 110, the process of step 112 is jumped to execute the process of step 114, and if "NO" is determined in step 110, the process of step 112 is executed. If “YES” is determined in the step 112, the process of the step 114 is executed. If “NO” is determined in the step 112, the program is returned to the step 110 and the process of the step 110 is executed.

  In each of the embodiments described above, when the supply of combustion fuel is stopped simultaneously with the supply of combustion oxidant gas, and then only the combustion oxidant gas is supplied, the period during which the supply of combustion oxidant gas is stopped There can be.

  Moreover, in each embodiment mentioned above, when the water vapor temperature does not rise above a predetermined temperature, there are two or more re-ignitions.

1 is a schematic diagram showing an outline of an embodiment of a fuel cell system to which a reformer according to the present invention is applied. It is a block diagram which shows the reforming apparatus shown in FIG. It is a flowchart of 1st Example of the control program performed with the control apparatus shown in FIG. It is a time chart which shows operation | movement of the reformer by the flowchart shown in FIG. It is a flowchart of 2nd Example of the control program run with the control apparatus shown in FIG. It is a time chart which shows operation | movement of the reformer by the flowchart shown in FIG. It is a flowchart of 3rd Example of the control program run with the control apparatus shown in FIG. It is a time chart which shows operation | movement of the reformer by the flowchart shown in FIG. It is a flowchart of 4th Example of the control program run with the control apparatus shown in FIG. It is a time chart which shows operation | movement of the reforming apparatus by the flowchart shown in FIG. It is a time chart which shows operation | movement of the reforming apparatus by the flowchart shown in FIG. It is a flowchart of 5th Example of the control program run with the control apparatus shown in FIG. It is a time chart which shows operation | movement of the reforming apparatus by the flowchart shown in FIG. It is a time chart which shows operation | movement of the reforming apparatus by the flowchart shown in FIG. It is a flowchart of 6th Example of the control program run with the control apparatus shown in FIG. It is a time chart which shows the operation | movement of the reformer by the flowchart shown in FIG. It is a time chart which shows the operation | movement of the reformer by the flowchart shown in FIG. It is a flowchart of 7th Example of the control program run with the control apparatus shown in FIG. It is a time chart which shows operation | movement of the reformer by the flowchart shown in a prior art.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Fuel cell, 11 ... Fuel electrode, 12 ... Air electrode, 20 ... Reformer, 21 ... Reformer, 21c ... Temperature sensor, 22 ... Cooling part (heat exchange part), 23 ... Carbon monoxide shift reaction part (CO shift part), 23c ... temperature sensor, 24 ... carbon monoxide selective oxidation reaction part (CO selective oxidation part), 24b ... temperature sensor, 25 ... combustion part, 26 ... evaporation part, 26a ... temperature sensor, 27 ... combustion Gas flow path, 28 ... heat insulation part, 41 ... fuel supply pipe, 42 ... reforming fuel pump, 43 ... reforming fuel valve, 44 ... combustion fuel supply pipe, 45 ... combustion fuel pump, 46 ... for combustion Fuel valve, 51 ... steam supply pipe, 52 ... feed water pipe, 53 ... reformed water pump, 54 ... reformed water valve, 61 ... oxidation air supply pipe, 62 ... oxidation air pump, 63 ... oxidation air valve, 64 ... Combustion air supply pipe, 65 ... Combustion air pump , 66 ... Combustion air valve, 67 ... Cathode air supply pipe, 68 ... Cathode air pump, 69 ... Cathode air valve, 71 ... Reformed gas supply pipe, 72 ... Off gas supply pipe, 73 ... Bypass pipe, 74 ... 1st reformed gas valve, 75 ... Off gas valve, 76 ... 2nd reformed gas valve, 81, 82 ... Exhaust pipe, 89 ... Connecting pipe.

Claims (10)

A reforming section that is supplied with reforming fuel and reforming water to generate reformed gas;
An evaporation unit that evaporates the reformed water and supplies the reformed water to the reforming unit;
Combustion fuel, at least one of the combustible gases from the reforming unit and the fuel electrode of the fuel cell and combustion oxidant gas can be supplied, and at least one of the combustible gases is supplied. A combustion section that burns with the combustion oxidant gas to generate combustion gas;
A combustion gas flow path in which the combustion gas from the combustion section heats the reforming section and the evaporation section in that order;
Combustion starting means for supplying the combustion fuel and the combustion oxidant gas to ignite the combustion section and supplying the reforming water to the evaporation section when starting the reformer;
A first fire extinguishing means for stopping the supply of the combustion fuel to the combustion section and extinguishing the combustion section when the temperature of the reforming section rises to a first predetermined temperature after the combustion of the combustion section starts; ,
And a control device including a combustion oxidant gas supply means for supplying the combustion oxidant gas during extinguishing of the combustion section.   2. The control device according to claim 1, wherein the control device sets at least one of a temperature of the reforming unit and a temperature of reforming water supplied to the reforming unit after extinguishing the combustion unit by the first extinguishing unit. A reforming apparatus, further comprising: a first re-ignition unit that re-ignites the combustion unit by supplying the combustion fuel or the reforming fuel based on the first re-ignition unit.   The first re-ignition unit according to claim 2, wherein the temperature of the reforming water supplied to the reforming unit is raised to a predetermined temperature for steam after the combustion unit is extinguished by the first extinguishing unit. When the temperature of the reforming section drops to a second predetermined temperature lower than the first predetermined temperature, the supply of the combustion fuel to the combustion section is resumed and the combustion section is re-ignited. Quality equipment. The reforming water supplied to the reforming unit according to claim 3, wherein the reforming unit is re-ignited with the combustion fuel by the first reignition unit and before the temperature of the reforming unit is raised to a first predetermined temperature. When the temperature of the water vapor is equal to or higher than a predetermined temperature for water vapor,
And a second re-ignition means for supplying the reforming fuel to the reforming section and re-igniting the combustion section.   3. The method according to claim 2, wherein the first re-ignition unit is configured to reduce the temperature of the reforming unit to a second predetermined temperature lower than the first predetermined temperature after the combustion unit is extinguished by the first fire-extinguishing unit. When the temperature of the reforming water supplied to the reforming unit rises to a predetermined temperature for steam, the supply of the combustion fuel to the combustion unit is resumed and the combustion unit is re-ignited. Quality equipment.   6. The first re-ignition means according to claim 5, wherein instead of supplying combustion fuel to the combustion section, the reforming fuel is supplied to the reforming section and the combustion section is re-ignited. Reformer.   3. The reforming unit according to claim 2, wherein the first re-ignition means supplies the reforming unit before the temperature of the reforming unit drops to a third predetermined temperature between the first predetermined temperature and the second predetermined temperature. When the temperature of the reformed water is raised to a predetermined temperature for steam, when the temperature of the reforming part is lowered to the third predetermined temperature, supply of the combustion fuel to the combustion part is started and the combustion is started. A reformer characterized by reigniting the part.   The first re-ignition means according to claim 7, wherein instead of supplying the combustion fuel to the combustion section, the reforming fuel is supplied to the reforming section and the combustion section is re-ignited. Reforming equipment.   3. The first re-ignition unit according to claim 2, wherein the temperature of the reforming unit is set to the first predetermined temperature before the temperature of the reforming water supplied to the reforming unit is raised to a predetermined temperature for steam. When the temperature is lowered to a third predetermined temperature between the second predetermined temperature and the temperature of the reforming water supplied to the reforming unit is raised to the predetermined temperature for steam, the combustion unit A reformer characterized by starting to supply combustion fuel and reigniting the combustion section. The reforming water supplied to the reforming section according to claim 9, wherein the reforming section is heated to a first predetermined temperature after the first re-ignition means re-ignites with the combustion fuel. When the temperature of the fuel is higher than or equal to a predetermined temperature for steam, when the temperature of the reforming section rises to the first predetermined temperature, only the supply of the combustion fuel to the combustion section is stopped. Fire extinguishing means,
After that, when the temperature of the reforming section is lowered to the third predetermined temperature, the second re-ignition means for supplying the reforming fuel to the reforming section and re-igniting the combustion section is further provided. A reformer characterized by that.

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