JP5171342B2 - Combustion device for reformer - Google Patents

Description

  The present invention relates to a combustion apparatus for a reformer.

As a type of combustion apparatus of a reformer, one shown in Patent Document 1 is known. As shown in FIG. 1 of Patent Document 1, the combustion apparatus of the reformer combusts so as to surround the fuel distributor 1 having a plurality of combustion ejection holes 8 for ejecting combustion gas into the combustion space 3. An air ejection member 2 having a plurality of air ejection holes 9 for ejecting air into the space is arranged, and one of the air ejection holes 9 of the air ejection member 2 has a temperature detection point slightly in the combustion space 3. And a temperature detecting member 6 for detecting the temperature of the combustion space 3 is provided.
JP 2004-156895 A

  In the combustion apparatus of the reformer described in Patent Document 1 described above, it is difficult to position the temperature detection point provided at the tip of the temperature detection member 6 so as to slightly protrude into the combustion space 3. If the temperature detection point cannot be accurately positioned, the temperature in the combustion space 3 may not be detected accurately.

  The present invention has been made to solve the above-described problems, and in the combustion apparatus of the reformer, the temperature sensing part of the temperature detector for detecting the temperature in the combustion space is accurately positioned and The purpose is to detect temperature accurately.

  In order to solve the above-described problem, the structural feature of the invention according to claim 1 is that the reforming device including the reforming unit that generates the reformed gas from the reforming fuel is provided to heat the reforming unit. A combustion chamber having a combustion space in which combustible gas is combusted, a rod-shaped temperature detector for detecting the temperature of the combustion space with a temperature sensing portion at the tip, and a shaft of the combustion cylinder A partition member that is internally partitioned in a direction and fixed to the combustion cylinder, a positioning member that positions the tip of the temperature detector with respect to the partition member so that the temperature of the combustion space can be detected, and the combustion space and the axial direction of the combustion cylinder A base provided so as to close the opposite end, a holding member attached to the base to hold the temperature detector, and an anchor fixed to the base end on the opposite side of the axial direction from the tip of the temperature detector The temperature detector is interposed between the stop portion, the holding member and the locking portion, and the base end portion. An urging member for urging the front end portion from is that having a.

  Further, the structural feature of the invention according to claim 2 is that in claim 1, the positioning member has a tip end positioned with respect to the partition member, and the temperature detector is inserted from the tip end of the temperature detector. It is a bottom tube-shaped protective tube.

  Further, the structural feature of the invention according to claim 3 is that, in claim 2, when the distal end portion of the protective tube is inserted into and fixed to the hole provided in the partition member, the outer portion of the distal end portion of the protective tube is fixed. That is, a positioning step for positioning the tip of the temperature detector so as to detect the temperature of the combustion space in contact with the wall surface of the partition member is formed on the wall surface.

  According to a fourth aspect of the present invention, in the first aspect, the positioning member is fixed to the distal end portion of the temperature detector, and is fixed by being inserted into a hole provided in the partition member. And a second locking portion that positions the tip of the temperature detector so as to be able to detect the temperature of the combustion space by contacting the wall surface of the partition member.

  In the invention according to claim 1 configured as described above, the positioning member positions the tip of the temperature detector with respect to the partition member so that the temperature of the combustion space can be detected. Furthermore, the biasing member interposed between the holding member attached to the base portion and holding the temperature detector and the locking portion fixed to the base end portion on the opposite side in the axial direction from the distal end portion of the temperature detector. The temperature detector whose tip is positioned with respect to the partition member by the positioning member by the biasing by the member is held at that position. As a result, the temperature detector is positioned accurately and reliably (without displacement) at a position where the temperature sensing portion at the tip can detect the temperature of the combustion space. Can be detected.

  In the invention according to claim 2 configured as described above, in the invention according to claim 1, the positioning member is positioned with respect to the partition member, and the temperature detector is inserted from the tip of the temperature detector. Therefore, the temperature detector is inserted into a protective tube whose tip is positioned at a predetermined position in the combustion space, and the holding member attached to the base and the base end of the temperature detector The tip of the temperature detector comes into contact with the inner tip of the protective tube by urging by the urging member interposed between the engaging portion fixed to the inner surface of the protective tube. As a result, the temperature detector is accurately and reliably positioned at a position where the temperature sensing portion at the tip can detect the temperature of the combustion space, and can detect the accurate temperature in the combustion space.

  In the invention which concerns on Claim 3 comprised as mentioned above, when the front-end | tip part of a protective tube is penetrated and fixed to the hole provided in the partition member in the invention which concerns on Claim 2, the front-end | tip of a protective tube Since the positioning step for positioning the tip of the temperature detector so that the temperature of the combustion space can be detected by contacting the wall of the partition member is formed on the outer wall surface of the partition member, the positioning step is used as the wall surface of the partition member. , The tip of the protective tube can be accurately positioned at a predetermined position (a position where the temperature of the combustion space 25d can be detected).

  In the invention which concerns on Claim 4 comprised as mentioned above, in the invention which concerns on Claim 1, a positioning member is fixed to the front-end | tip part of a temperature detector, and is penetrated and fixed to the hole provided in the partition member. And a second locking portion that positions the tip of the temperature detector so that the temperature of the combustion space can be detected by contacting the wall surface of the partition member. Thereby, a 2nd latching | locking part positions the front-end | tip part of a temperature detector with respect to a partition member so that the temperature of combustion space is detectable. Furthermore, the biasing member interposed between the holding member attached to the base portion and holding the temperature detector and the locking portion fixed to the base end portion on the opposite side in the axial direction from the distal end portion of the temperature detector. The temperature detector whose tip is positioned with respect to the partition member by the second locking portion by the biasing by the member is held at that position. As a result, the temperature detector is positioned accurately and reliably (without displacement) at a position where the temperature sensing portion at the tip can detect the temperature of the combustion space. Can be detected.

  Hereinafter, an embodiment of a fuel cell system to which a combustion apparatus of a reformer according to the present invention is applied will be described with reference to FIGS. The top and bottom in FIGS. 1 and 2 are the top and bottom in the direction of gravity. FIG. 1 is a schematic diagram showing an outline of this fuel cell system. The fuel cell system includes a fuel cell 10 and a reformer 20 that generates a reformed gas (fuel 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 a “carbon monoxide shift reaction 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 (combustion device) 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 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 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 reforming 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 reforming fuel supply pipe 41 is provided with a fuel pump 42, a desulfurizer 46, and a reforming fuel valve 43 in order from the upstream. The reforming fuel valve 43 opens and closes the reforming fuel supply pipe 41. The fuel pump 42 is reforming fuel supply means for supplying reforming fuel and adjusting the supply amount. The desulfurizer 46 removes sulfur (for example, sulfur compounds) in the fuel. Of the fuel supplied from the fuel supply source, the fuel supplied to the reforming unit 21 and reformed is referred to as reforming fuel, and the fuel supplied to the combustion unit 25 and combusted is referred to as combustion fuel.

  A combustion fuel supply pipe 44 connected to a combustion air supply pipe 64 connected to the combustion section 25 is connected between the desulfurizer 46 and the reforming fuel valve 43 of the reforming fuel supply pipe 41. Has been. A combustion fuel valve 45 is provided in the combustion fuel supply pipe 44. The combustion fuel valve 45 opens and closes the combustion fuel supply pipe 44. When the fuel pump 42 is driven and the reforming fuel valve 43 is closed and the combustion fuel valve 45 is opened, the combustion fuel is supplied to the combustion unit 25, and the fuel pump 42 is driven and the reforming fuel. When the valve 43 is opened and the combustion fuel valve 45 is closed, the reforming fuel is supplied to the reforming unit 21.

  Further, a steam supply pipe 51 connected to the evaporation section 26 is connected between the reforming fuel valve 43 and the cooling section 22 of the reforming fuel supply pipe 41. 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.

  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).

  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.

  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 and the second reformed gas valve 76 is opened in order to avoid supplying 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 and the second reformed gas valve 76 is closed in order to supply the reformed gas from the reformer 20 to the fuel cell 10. .

  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 combustion unit 25 generates combustion gas for heating the reforming unit 21 and supplying heat necessary for the steam reforming reaction, and has a lower end portion with a space in the inner peripheral wall of the reforming unit 21. Has been inserted. The combustion section 25 burns the anode off-gas from the fuel electrode 11 or the fuel gas from the reforming section 21 with combustion oxidant gas to generate combustion gas when performing diffusion combustion, and supplies fuel when premixed combustion is performed. It is a combustion apparatus that generates a combustion gas by burning a premixed gas in which a combustion fuel and a combustion oxidant gas from a source are premixed, and heats the reforming unit 21 with any of these combustion gases.

  As shown in FIG. 2, the combustion unit 25 includes a base 25a, a cylindrical combustion tube 25b provided on the base 25a and communicating with the base 25a, an off-gas nozzle 25c, a temperature sensor (temperature detector) 25e, And a protective tube (positioning member) 25f. In addition, the combustion part 25 is ignited by the electrode for ignition (illustration omitted) according to the instruction | command of a control apparatus.

  The base portion 25a includes a substantially circular base plate 25a1 and a cylindrical base casing 25a2 fixed to cover the lower side of the base plate 25a1. A connection path 25a5 having a first inlet 25a3 and an outlet 25a4 is formed in the base plate 25a1, and an off-gas supply pipe 72 is connected to the first inlet 25a3 of the connection path 25a5. An off-gas nozzle 25c is connected to the outlet 25a4. The base casing 25a2 is provided with a second inlet 25a6, and a combustion air supply pipe 64 communicating with a space 25a7 formed by the base plate 25a1 and the base casing 25a2 is connected to the second inlet 25a6. Has been. The base portion 25a is provided so as to close the end portion on the opposite side to the combustion space 25d of the combustion cylinder 25b in the axial direction.

  The combustion cylinder 25b is provided (fixed) with a disk-like partition plate (partition member) 25b1 on the lower end side from the intermediate portion in the axial direction, and this partition plate 25b1 opens the space in the combustion cylinder 25b. It is partitioned in the axial direction. The partition plate 25b1 is fixed to the combustion cylinder 25b by welding, but may be fixed by press-fitting or mechanical coupling.

  Note that the space above the combustion cylinder 25b partitioned by the partition plate 25b1 communicates with the space 25a7 of the base 25a, and the space below the combustion cylinder 25b partitioned by the partition plate 25b1 is opened downward. The lower space is a combustion space 25d described later. A plurality of second injection ports 25b2 are provided in the partition plate 25b1. Further, in this embodiment, the partition plate 25b1 is also used as a member provided with the premixed gas ejection port 25b2. However, the partition plate 25b1 does not necessarily partition the passage of gas, and the temperature sensor 25e or the protective tube It is only necessary that the tip of 25f can be positioned.

  The off-gas nozzle 25c has a bottomed tube shape and extends into the space 25a7 and the combustion cylinder 25b. The base end communicates with the connection path 25a5 and is fixed to the base plate 25a1 of the base portion 25a, and the distal end portion is a partition plate. 25b1 is inserted into the central hole. The tip of the off-gas nozzle 25c extends into the combustion space 25d, and a plurality of first injection ports 25c1 are provided on the peripheral surface of the tip. The first injection ports 25c1 are opened in the radial direction of the off-gas nozzle 25c and provided at four locations at equal intervals.

  The first supply path L1 described in the claims of the present application includes a connection path 25a5 and a space in the off-gas nozzle 25c, and injects combustion fuel from the first inlet 25a3 and supplies it to the combustion space 25d. To do. The second supply path L2 includes a space 25a7 and a space 25b3 between the combustion cylinder 25b and the off-gas nozzle 25c above the partition plate 25b1, and allows at least combustion oxidant gas to flow from the second inlet 25a6. This is supplied to the combustion space 25d.

  The combustion space 25d is a space for combusting combustion fuel, anode off gas, and combustible gas as reformed gas, and is a lower space partitioned by the partition plate 25b1 in the combustion cylinder 25b, and is an off gas nozzle. This is the space on the side where the tip of 25c protrudes. In addition, the wall member which forms this combustion space 25d is a lower side part and the partition plate 25b1 from the partition plate 25b1 of the combustion cylinder 25b.

  The temperature sensor 25e has a rod shape, for example, a sheath thermocouple is used. The temperature sensor 25e detects the radiation temperature of the flame 25i generated in the combustion space 25d of the combustion unit 25 by the temperature sensing unit 25e5 at the distal end portion (a little proximal side from the distal end 25e1), and transmits the detection result to the control device. (For example, a radiation thermometer). The temperature sensor 25e passes through the base plate 25a1 and the partition plate 25b1 of the base portion 25a, and the tip portion thereof is disposed in the combustion space 25d. In the present embodiment, a sheathed thermocouple is used as the temperature sensor 25e, but the present invention is not limited to this, and a thermistor may be used.

  The protection tube 25f has a bottomed tube shape in which the tip portion is positioned with respect to the partition plate 25b1, and the temperature sensor 25e is inserted from the tip portion of the temperature sensor 25e, and accommodates the temperature sensor 25e. The protective tube 25f is a positioning member that positions the tip of the temperature sensor 25e with respect to the partition plate 25b1 so that the temperature of the combustion space 25d can be detected.

  The protective tube 25f includes a tube portion 25f1 and a cap portion 25f2 whose tip is closed, and these are integrally connected and fixed. The protective tube 25f is formed of a stainless steel metal, but may be a heat resistant metal other than stainless steel, or a ceramic material such as alumina. Note that the protective tube 25f may be a tube member 25f1 and a cap portion 25f2 formed of a single member. The protective tube 25f extends into the space 25a7 and the combustion cylinder 25b (space 25b3), and the base end is inserted into a hole provided in the base plate 25a1 of the base 25a and fixed by welding, and the cap at the tip The portion 25f2 is inserted through a hole provided in the partition plate 25b1 and fixed by welding. On the peripheral surface (outer wall surface) of the cap portion 25f2, a step portion (positioning step portion: formed with different outer diameters) 25f3 is formed in the axial direction of the temperature sensor 25e, and this step portion 25f3 is formed on the partition plate 25b1. By contacting the upper surface (wall surface), when the cap portion 25f2 is inserted into the hole provided in the partition plate 25b1, the tip of the cap portion 25f2 is positioned at a predetermined position in the combustion space 25d. The step portion 25f3 is formed on the entire peripheral surface of the cap portion 25f2. However, the step portion 25f3 is not limited to this, and the step portion 25f3 is configured by at least one protrusion formed on the outer peripheral surface of the cap portion 25f2. It may be.

  The predetermined position where the tip of the protective tube 25f is fixed is a position inside the combustion space 25d and outside the flame surface 25i1 of the flame 25i where the radiant heat of the flame 25i can be measured. In the present embodiment, the tip of the cap portion 25f2 of the protective tube 25f has a thickness of 0.3 mm and is positioned by protruding 0.8 mm from the partition plate 25b1 toward the combustion space 25d. The tip of the temperature sensor 25e inserted into the protective tube 25f is, like the tip of the protective tube 25f, inside the combustion space 25d and outside the flame surface 25i1 of the flame 25i, and the radiant heat of the flame 25i is generated. It arrange | positions in the position which can be measured, and becomes a position which protruded 0.5 mm toward the combustion space 25d from the partition plate 25b1. Here, the flame surface refers to a boundary surface between a portion where a combustion reaction of a combustible gas such as a combustion gas or a premixed gas occurs and the other portion.

  The temperature sensor 25e is inserted into the protective tube 25f, and the tip of the temperature sensor 25e is in contact with the inner tip of the cap portion 25f2 of the protective tube 25f. A holding bracket (holding member) 25g for holding the temperature sensor 25e is provided (attached) to the upper surface (outer wall surface) of the base plate 25a1 of the base portion 25a. The holding bracket 25g is substantially Z-shaped bent at a right angle, and the lower plate portion 25g1 of the holding bracket 25g is screwed and fixed to the upper surface of the base plate 25a1, and a through hole provided in the upper plate portion 25g2 of the holding bracket 25g. The temperature sensor 25e is inserted through the temperature sensor 25e so as to be movable in the axial direction. The lower plate portion 25g1 is fixed by screwing to the base plate 25a1, but may be fixed by joining such as welding.

  A locking portion (first locking portion) 25e2 is fixed to a base end portion on the opposite side in the axial direction from the distal end portion of the temperature sensor 25e. An annular locking portion 25e2 is fixed by caulking to the temperature sensor 25e at a position below the upper plate portion 25g2 of the holding bracket 25g. Note that the locking portion 25e2 is not limited to an annular shape, and may be a polygonal shape or at least a pair of opposed protrusions. Moreover, although the latching | locking part 25e2 is crimped and fixed to the temperature sensor 25e, you may fix by joining, such as adhesion | attachment.

  Between the upper plate portion 25g2 of the holding bracket 25g and the locking portion 25e2 of the temperature sensor 25e, the tip of the temperature sensor 25e is set to the inner tip of the protective tube 25f (the temperature sensor 25e is moved from the base end side to the tip end side). ) A biasing member 25h for biasing is interposed. The urging member 25h is made of a flexible elastic material that urges the temperature sensor 25e so that the tip of the temperature sensor 25e is not separated from the inner tip of the protective tube 25f and is not excessively stressed. In the present embodiment, the energizing member 25h is an annular member made of sponge (made of sponge-like rubber or synthetic resin). The tip of the temperature sensor 25e is always in contact with the inner tip of the cap portion 25f2 of the protective tube 25f by the urging force of the urging member 25h. The biasing member 25h according to the present invention is not limited to the sponge-shaped annular member, but is made of an elastic material made of foam (for example, foamed plastic such as polyurethane or rubber) or an elastic material made of rubber. Alternatively, a spring member such as a compression coil spring in which the repulsive force is kept low and excessive stress is not applied may be used. Further, the urging member 25h is not limited to an annular member, and may be a C-shaped member.

  When diffusion combustion is performed, the anode off gas or the reformed gas flows into the first supply path L1 from the first inlet 25a3. That is, the anode off-gas or reformed gas flowing in from the first inlet 25a3 is supplied from the first injection port 25c1 to the combustion space 25d through the connection path 25a5 and the off-gas nozzle 25c (through the first supply path L1). The At this time, combustion air flows into the second supply path L2 from the second inlet 25a6. That is, the combustion air flowing in from the second inlet 25a6 is supplied from the second injection port 25b2 to the combustion space 25d through the space 25a7 in the base 25a and the space 25b3 in the combustion cylinder 25b.

  On the other hand, when premixed combustion is performed, the premixed gas flows into the second supply path L2 from the second inlet 25a6. That is, the premixed gas flowing in from the second inlet 25a6 burns from the second injection port 25b2 through the space 25a7 in the base 25a and the space 25b3 in the combustion cylinder 25b (through the second supply path L2). It is supplied to the space 25d. The premixed gas is supplied through the combustion air supply pipe 64.

  As shown in FIG. 1, the combustion air supply pipe 64 is provided with a combustion air pump (combustion oxidant gas supply means) 65 and a combustion air valve 66. The combustion air pump 65 sucks combustion air from the atmosphere and discharges it to the combustion unit 25, and adjusts the amount of combustion air supplied to the combustion unit 25 in accordance with a command from the control device. The combustion air valve 66 opens and closes the combustion air supply pipe 64 in accordance with a command from the control device.

  The combustion air valve 66 is opened and combustion is performed from the time when the system starts to start (start of starting the fuel cell system (reforming device 20)) until the supply of the reforming fuel to the reforming unit 21 starts. As the air pump 65 is driven, the reforming fuel valve 43, the first reformed gas valve 74, and the offgas valve 75 are closed, the combustion fuel valve 45 is opened, and the fuel pump 42 is driven. The combustion fuel passes through the combustion fuel supply pipe 44 without passing through the reforming section 21 and is mixed with the combustion air in the combustion air supply pipe 64 and mixed, and the premixed gas passes through the combustion air supply pipe 64. It is supplied to the combustion part 25 through. Supply of the reforming fuel to the reforming unit 21 is started after steam is generated in the evaporation unit 26 and the reforming unit 21 reaches a predetermined temperature or higher.

  In addition, the reforming fuel valve 43 and the second reformed gas valve 76 are opened from the start of supply of the reforming fuel to the reforming unit 21 to the start of steady operation (power generation), and the combustion fuel valve 45 is opened. Is closed and the fuel pump 42 is driven. The first reformed gas valve 74 and the offgas valve 75 remain closed. Thus, in order to avoid supplying reformed gas having a high carbon monoxide concentration from the CO selective oxidation unit 24 to the fuel cell 10, the reformed gas from the CO selective oxidation unit 24 is supplied to the fuel cell 10 in the combustion unit 25. Supplied directly without going through. Combustion air is supplied in the same manner as described above. In other words, the reforming gas is supplied to the combustion unit 25 through the off-gas supply pipe 72 and combustion air is supplied through the combustion air supply pipe 64.

  During steady operation (power generation), the reforming fuel valve 43, the first reformed gas valve 74, and the offgas valve 75 are opened, the combustion fuel valve 45 and the second reformed gas valve 76 are closed, and the fuel pump. 42 is driven. As a result, the combustion portion 25 contains the anode off-gas from the fuel electrode 11 of the fuel cell 10 (hydrogen that has been supplied to the fuel electrode 11 of the fuel cell 10 and discharged without being consumed, or unreformed reforming fuel). Reformed gas) is supplied. Combustion air is supplied in the same manner as described above. That is, anode offgas is supplied to the combustion unit 25 through the offgas supply pipe 72 and combustion air is supplied through the combustion air supply pipe 64. At this time, the combustion unit 25 does not recharge the combustion by separately adding a combustible gas such as a combustion fuel. This is a so-called reboundless system.

  As described above, in the combustion unit 25, the combustion fuel, reformed gas, or anode off gas (these are combustible gases) supplied to the combustion unit 25 are combusted by the combustion air supplied to the combustion unit 25. Hot combustion gas is generated. This combustion gas is formed between the reforming section 21 and the heat insulating section 28 and between the heat insulating section 28 and the evaporation section 26 and disposed so as to heat the reforming section 21 and the evaporation section 26. It flows through the flow path 27, passes through the exhaust pipe 81, and is discharged to the outside as combustion exhaust gas. The combustion gas heats the reforming catalyst 21a of the reforming unit 21 so as to be in the activation temperature range, and heats the evaporation unit 22 to generate water vapor.

  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 leads to the reforming part 21 through the cooling part 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.

  As is apparent from the above description, in this embodiment, the positioning member (partition plate) 25b1 can detect the temperature of the combustion space 25d so that the tip of the temperature detector (temperature sensor) 25e is separated from the partition member 25b1. Position with respect to. Further, a holding member 25g that is attached to the base portion 25a and holds the temperature detector 25e, and a locking portion 25e2 that is fixed to the base end portion on the opposite side in the axial direction from the distal end portion of the temperature detector 25e. The temperature detector 25e whose tip is positioned with respect to the partition member 25b1 by the positioning member (protective tube) 25f is held in that position by the biasing by the loaded biasing member 25h. As a result, the temperature detector 25e is positioned accurately and reliably (without displacement) at a position where the temperature sensing portion 25e5 at the tip can detect the temperature of the combustion space. Accurate temperature can be detected. Further, by detecting the accurate temperature in this way, the combustion control of the combustion unit 25 can be accurately performed based on the detection result. Further, the temperature in the combustion space 25d can be accurately detected, and the flow meter for either combustion air or combustible gas (fuel) can be eliminated, thereby reducing the cost.

  Further, the positioning member is a bottomed tube-shaped protective tube 25f in which the tip portion is positioned with respect to the partition member 25b1 and the temperature detector 25e is inserted from the tip portion of the temperature detector (temperature sensor) 25e. The temperature detector 25e is inserted into a protective tube 25f whose tip is positioned at a predetermined position in the combustion space 25d, and is fixed to a holding member (holding bracket) 25g attached to the base portion 25a and a base end portion of the temperature detector 25e. The tip of the temperature detector 25e comes into contact with the inner tip of the protective tube 25f by urging by the urging member 25h interposed between the engaging portion 25e2 and the engaging portion 25e2. Thus, the temperature detector 25e is accurately and reliably positioned at a position where the temperature sensing portion 25e5 at the tip can detect the temperature of the combustion space 25d, and detects the accurate temperature in the combustion space 25d. be able to. Further, by detecting the accurate temperature in this way, the combustion control of the combustion unit 25 can be accurately performed based on the detection result. Further, the temperature in the combustion space 25d can be accurately detected, and the flow meter for either combustion air or combustible gas (fuel) can be eliminated, thereby reducing the cost. Furthermore, since the tip of the temperature sensor 25e is urged by the urging member 25h to the inside tip of the protective tube 25f, the temperature sensor 25e and the protective tube 25f can be heated and contracted so that the temperature sensor 25e and the protective tube 25f are different from each other. The tip of the sensor 25e is always brought into contact with the inner tip of the protective tube, and the tip of the temperature sensitive portion 25e5 does not shift. Further, the temperature detector 25e can be protected from the combustion atmosphere (which is an intense oxidation reaction field) by the protective tube 25f, and the durability of the temperature detector 25e can be improved.

  Further, when the distal end portion of the protective tube 25f is inserted and fixed in a hole provided in the partition member (partition plate) 25b1, the outer wall surface of the distal end portion of the protective tube 25f is provided on the wall surface (upper surface) of the partition member 25b1. Since the positioning step portion 25f3 for positioning the tip of the temperature detector 25e is formed so that the temperature of the combustion space 25d can be detected, the positioning step portion 25f3 is brought into contact with the wall surface of the partition member 25b1. Thus, the tip of the protective tube 25f can be accurately positioned at a predetermined position (a position where the temperature of the combustion space 25d can be detected).

  In addition, in this Embodiment, although the combustion part 25 is comprised so that a flame may be formed below, it is not restricted to this, It is comprised so that a flame may be formed upwards or a side. You may do it.

  Moreover, although the base end part of the protective tube 25f is fixed to the base plate 25a1, and the cap part 25f2 is fixed to the partition plate 25b1, it is not always necessary to fix it, and only the cap part 25f2 may be fixed. If the step 25f3 that cannot pass through the hole of the partition plate 25b1 is provided in the cap 25f2, the protective tube 25f is positioned by the biasing force of the biasing member 25h. For this reason, what is necessary is just to seal with the O-ring etc. so that between the hole of the protective tube 25f and the baseplate 25a1 may have gas impermeability. Thereby, thermal expansion of the combustion cylinder 25b etc. can be absorbed.

  Furthermore, in the embodiment, the temperature sensing portion 25e5 (tip) of the temperature sensor 25e is provided inside the combustion space 25d and outside the flame surface 25i1 of the flame 25i, but may be anywhere as long as the combustion temperature can be measured. . For example, in the embodiment, the tip of the temperature sensor 25e is positioned by protruding 0.5 mm from the partition plate 25b1 toward the combustion space 25d, but if the radiant heat of the flame 25i can be measured even within the hole of the partition plate 25b1. Good. Further, the tip of the temperature sensor 25e may be in the flame surface. A position where the tip of the temperature sensor 25e protrudes 1 mm toward the combustion space 25d from a position away from the combustion space 25d by 0.5 mm from the plane on the combustion space 25d side of the partition plate 25b1 is desirable. More desirably, as in the embodiment, the tip of the temperature sensor 25e should be in the combustion space 25d (projecting from the partition plate 25b1 toward the combustion space 25d) and outside the flame surface 25i1. This is because the temperature measurement accuracy is improved and the durability of the temperature sensor 25e can be improved.

  Furthermore, in the above-described embodiment, the protective tube 25f is employed as the positioning member, but instead of this, a second locking portion 25e3 provided directly on the temperature sensor 25e may be employed. As shown in FIG. 3, the second locking portion 25e3 is fixed to the distal end portion of the temperature sensor 25e, and is fixed to the wall surface of the partition member 25b1 when the second locking portion 25e3 is fixed by being inserted into a hole provided in the partition member 25b1. The tip of the temperature sensor 25e is positioned so as to be able to detect the temperature of the combustion space 25d. The second locking portion 25e3 is caulked and fixed similarly to the locking portion 25e2. The position to be positioned is the same as in the above embodiment. In the description of FIG. 3, the same components as those in FIG.

  The second locking portion 25e3 may be fixed to the temperature sensor 25e in advance. In this case, the base plate 25a1 is provided with a hole having a diameter larger than that of the second locking portion 25e2 fixed in advance to the temperature sensor 25e, and the gap between the large diameter hole and the positioned temperature sensor 25e is sealed. The sealing member 25e4 may be interposed between the base plate 25a1 and the temperature sensor 25e. Thereby, it can be assembled easily and the thermal expansion of the combustion cylinder 25b etc. can be absorbed.

  According to such a structure, the 2nd latching | locking part 25e3 positions the front-end | tip part of the temperature sensor 25e with respect to the partition member 25b1 so that the temperature of the combustion space 25d can be detected. Furthermore, it is interposed between a holding member 25g that is attached to the base portion 25 and holds the temperature sensor 25e, and a locking portion 25e2 that is fixed to the base end portion on the opposite side in the axial direction from the distal end portion of the temperature sensor 25e. Due to the urging by the urging member 25h, the temperature sensor 25e whose tip is positioned with respect to the partition member 25b1 by the second locking portion 25e3 is held in that position. As a result, the temperature sensor 25e is positioned accurately and reliably (without displacement) at a position where the temperature sensing portion 25e2 at the tip can detect the temperature of the combustion space 25d. Accurate temperature can be detected.

1 is a schematic diagram showing an outline of a fuel cell system to which an embodiment of a combustion apparatus of a reformer according to the present invention is applied. It is sectional drawing which shows the combustion part shown in FIG. It is sectional drawing which shows other embodiment of the combustion part shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Fuel cell, 11 ... Fuel electrode, 12 ... Air electrode, 20 ... Reformer, 21 ... Reformer, 22 ... Cooling part (heat exchange part), 23 ... Carbon monoxide shift reaction part (CO shift part) 24 ... Carbon monoxide selective oxidation reaction part (CO selective oxidation part), 25 ... Combustion part (combustion device), 25a ... Base, 25b ... Combustion cylinder, 25b1 ... Partition plate (partition member), 25c ... Off-gas nozzle, 25c1 ... 1st jet nozzle, 25e ... Temperature sensor (temperature detector), 25e2 ... Locking part, 25e3 ... 2nd locking part (positioning member), 25e5 ... Temperature sensing part, 25f ... Protection tube (positioning member), 25f3 ... Step part (positioning step part) 25g ... Holding bracket (holding member), 25h ... Biasing member, 26 ... Evaporation part, 27 ... Combustion gas flow path, 28 ... Heat insulation part, 41 ... Fuel supply pipe, 42 ... Fuel Pump, 43 ... Fuel valve for reforming, 4 ... Combustion fuel supply pipe, 45 ... Combustion fuel valve, 46 ... Desulfurizer, 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 ... first reformed gas valve, 75 ... off gas valve, 76 ... second reformed gas valve 81, 82 ... exhaust pipe, 89 ... connecting pipe, L1 ... first supply path, L2 ... second supply path.

Claims (4)

A combustion apparatus that is provided in a reformer that includes a reformer that generates reformed gas from reforming fuel and that heats the reformer,
A cylindrical combustion cylinder having a combustion space in which combustible gas is burned,
A rod-shaped temperature detector for detecting the temperature of the combustion space at the temperature sensing portion at the tip;
A partition member that partitions the inside in the axial direction of the combustion cylinder and is fixed to the combustion cylinder;
A positioning member that positions the tip of the temperature detector with respect to the partition member so that the temperature of the combustion space can be detected;
A base provided so as to close an end of the combustion cylinder opposite to the combustion space in the axial direction;
A holding member attached to the base and holding the temperature detector;
A locking portion fixed to the proximal end portion on the opposite side in the axial direction from the distal end portion of the temperature detector;
And a biasing member interposed between the holding member and the locking portion and biasing the temperature detector from the base end side to the tip end side. Combustion device of the device.   The positioning member according to claim 1, wherein the positioning member is a bottomed tube-shaped protective tube in which a tip portion is positioned with respect to the partition member and the temperature detector is inserted from the tip portion of the temperature detector. A reformer combustion apparatus characterized by the above.   3. The outer wall surface of the distal end portion of the protective tube is in contact with the wall surface of the partition member when the distal end portion of the protective tube is inserted into and fixed to a hole provided in the partition member. A combustion apparatus for a reformer, wherein a positioning step for positioning the tip of the temperature detector so as to be able to detect the temperature of the combustion space is formed. 2. The positioning member according to claim 1, wherein the positioning member is fixed to the tip portion of the temperature detector, and is in contact with a wall surface of the partition member when being inserted into and fixed to a hole provided in the partition member. A combustion apparatus for a reformer, wherein the combustion apparatus is a second locking portion that positions the tip of the temperature detector so that the temperature of the combustion space can be detected.

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