JP5348482B2 - Fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell system advantageous to reduce a risk of freezing of residual reforming water when the reforming water remains in reforming water-supplying piping in a cold district or in the winter season even after power generation of a fuel cell is stopped. <P>SOLUTION: The system includes: an evaporation part 20; a reforming part 22; a fuel cell 1; the reforming water-supplying piping 410 forming a reforming water-supplying passage 41 through which reforming water is supplied to the evaporation part 20; fuel raw material supply piping 510 forming a fuel raw material supply passage 51 through which a fuel raw material is supplied to a reforming party 22; and a heat insulating wall 30 formed with a heat insulating material. The reforming water-supplying piping 410 is arranged in parallel on the inside surface 31 and the outside surface 33 of the heat insulating wall 30 and embedded in the heat insulating wall 30. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a fuel cell system having a heat insulating wall formed of a heat insulating material that covers a fuel cell and a reforming portion for heat insulation.

  The fuel cell system includes an evaporation unit that is heated by a combustion flame to vaporize reformed water, a reforming unit that steam-reforms a fuel raw material with water vapor generated by the evaporation unit, and an anode gas generated by the reforming unit A fuel cell that generates electricity with the cathode gas, a reforming water supply pipe that supplies reforming water to the evaporation section, and a fuel raw material supply pipe that supplies the fuel raw material to be steam reformed to the reforming section via the evaporation section And a heat insulating wall formed of a heat insulating material that covers the outside of the fuel cell and the reforming portion for heat insulation (Patent Document 1).

JP 2008-53209 A

  However, even in the above-described system, in cold districts and winter seasons, if the reformed water remains in the reformed water supply pipe after the power generation of the fuel cell is stopped, the remaining reformed water may freeze. There is. In this case, there is a risk of hindering the next start-up of the fuel cell.

  The present invention has been made in view of the above circumstances, and in the cold districts and winter seasons, when the reformed water remains in the reformed water supply pipe, there is a risk that the remaining reformed water will freeze. It is an object of the present invention to provide a fuel cell system that is advantageous for reduction.

  The fuel cell system according to the present invention is provided with (i) an evaporation section that is heated by a combustion flame to vaporize the reformed water, and (ii) communicates with the evaporation section and is heated by the combustion flame. (Iii) a fuel cell that generates electric power from the anode gas and the cathode gas generated in the reforming unit, and (iv) a reforming unit that reforms the fuel raw material with water vapor generated in the evaporation unit to generate an anode gas; ) A reforming water supply pipe for supplying reforming water to the evaporation section; (v) a fuel raw material supply pipe for supplying a fuel raw material to be reformed with steam to the reforming section; and (vi) at least a fuel cell and a reforming section. And (vii) the heat insulation wall is formed on the inner surface and the outer surface of the heat insulation wall. Running reformed water supply pipes in parallel Incubating the reforming water supply pipe by residual heat of the heat insulating wall during and power shutdown is embedded inside the insulating wall.

  The evaporating section is heated with a combustion flame to a temperature at which water vapor can be generated. The reforming section is provided to be heated by the combustion flame, and steam reforms the fuel material with the steam generated in the evaporation section to generate anode gas. The combustion source of the combustion flame that heats the reforming part may be the same as or different from the combustion flame that heats the evaporation part. The combustion flame can function as a heating element for heating the reforming section and the evaporation section. The reforming water supply pipe generated in the reforming unit forms a reforming water supply passage for supplying the reforming water to the evaporation unit. The fuel material supply pipe forms a fuel material supply passage for directly or indirectly supplying the fuel material to be reformed with steam to the reforming unit.

  Now, when the fuel cell is in a power generation operation, the temperature of the fuel cell and the reformer is high with respect to the outside air. The heat insulation wall maintains the heat insulation state of the fuel cell and the reforming section with respect to the outside air. Here, when the power generation operation of the fuel cell is stopped, the temperature gradually decreases from the temperature during the power generation operation of the fuel cell. However, since the heat insulating wall has high heat insulating properties, the temperature of the fuel cell and the reforming section can be maintained for a long time. In this case, although the temperature of the heat insulation wall gradually decreases from the temperature during the power generation operation, the temperature of the heat insulation wall is maintained higher than the outside air temperature for a long time.

  Here, the reforming water supply pipe is embedded in the heat insulation wall while running parallel to the inner surface and the outer surface of the heat insulation wall. For this reason, even after the power generation of the fuel cell is stopped, the reformed water supply pipe can be maintained over the freezing start temperature for a long time due to the residual heat of the heat insulating wall. Therefore, excessive freezing of the reforming water supply pipe can be suppressed even in cold regions or in winter. Parallel running means that the reforming water supply piping is arranged along the direction in which the inner surface and the outer surface of the heat insulating wall extend, and is embedded in the heat insulating wall. Preferably, it means that the reforming water supply pipe is embedded in the heat insulation wall while being arranged substantially in parallel along the direction in which the inner surface and the outer surface of the heat insulation wall extend.

  According to the present invention, even after the power generation of the fuel cell is stopped, the reformed water supply pipe can be maintained at the freezing start temperature or higher due to the residual heat of the heat insulating wall. For this reason, freezing and further freezing of the reforming water supply pipe can be suppressed. Therefore, the fuel cell can be restarted satisfactorily.

1 is a diagram schematically showing a concept of a fuel cell system according to Embodiment 1. FIG. 1 is a cross-sectional view illustrating a concept of a fuel cell module according to Embodiment 1 and surrounded by a heat insulating wall. FIG. 3 is a cross-sectional view showing the vicinity of the fuel cell and the reforming unit of the fuel cell module according to Embodiment 1. FIG. 6 is a cross-sectional view showing a concept of a fuel cell module according to Embodiment 2 and surrounded by a heat insulating wall. It is sectional drawing which concerns on Embodiment 3 and shows the state of piping currently embed | buried under the inside of a heat insulation wall. It is sectional drawing which concerns on Embodiment 4 and shows the state of piping currently embed | buried under the inside of a heat insulation wall. FIG. 10 is a cross-sectional view illustrating a concept of a fuel cell module according to Embodiment 5 and surrounded by a heat insulating wall. FIG. 10 is a cross-sectional view illustrating a concept of a fuel cell module according to Embodiment 6 and surrounded by a heat insulating wall. FIG. 10 is a diagram schematically showing a concept of a fuel cell system according to Embodiment 7. FIG. 10 is a cross-sectional view illustrating a concept of a fuel cell module according to Embodiment 8 and surrounded by a heat insulating wall. FIG. 16 is a diagram schematically showing the concept of a fuel cell system according to Embodiment 9.

  According to the present invention, the operating temperature of the fuel cell is preferably 70 ° C. or higher, or 200 ° C. or higher. In particular, 500 ° C. or higher is preferable. Examples of the fuel cell include a solid oxide form, a phosphoric acid form, a molten carbonate form, and a solid polymer form. Examples of the upper limit of the operating temperature are 1200 ° C, 1000 ° C, and 900 ° C. The operating temperature refers to the temperature of the electrolyte when the fuel cell performs rated power generation operation. According to a preferred embodiment, the heat insulating wall is embedded in the heat insulating wall while the fuel material supply pipes run parallel to the inner surface and the outer surface of the heat insulating wall. Even when moisture is adhering to the fuel raw material supply pipe, the remaining heat of the heat insulating wall is maintained for a long time, so that freezing of the fuel raw material supply pipe is also suppressed.

  According to a preferred embodiment, an air pipe is provided for supplying the fuel cell with air that oxidizes the fuel material and generates heat of oxidation when the fuel cell is started. The heat insulating wall is embedded in the heat insulating wall while air pipes run parallel to the inner surface and the outer surface of the heat insulating wall. Even when moisture is attached to the air pipe, freezing of the air pipe is also suppressed due to the residual heat of the heat insulating wall. According to a preferred embodiment, an outer box that houses the fuel cell, the evaporation portion reforming portion, and the heat insulating wall is provided. In this case, the outer box accommodates the fuel cell, the evaporation unit, and the reforming unit, and receives a first chamber that receives heat from the fuel cell, the evaporation unit, and the reforming unit, and auxiliary equipment related to the power generation operation of the fuel cell. A second chamber that is housed and has a temperature lower than that of the first chamber when the power generation operation is stopped, and a partition wall that partitions the first chamber and the second chamber. The first chamber tends to be hotter than the second chamber, and the second chamber tends to be cooler than the first chamber. For this reason, in a cold district or winter, when the fuel cell is in a power generation stop state, the auxiliary machine in the second chamber may freeze.

  Therefore, according to a preferred embodiment, the heat insulation wall has an entry heat insulation wall that enters the second chamber from the first chamber, is exposed to the second chamber, and releases residual heat to the second chamber. The insulative heat insulating wall is exposed to the second chamber and releases heat to the second chamber. In this case, even when the power generation operation of the fuel cell is stopped, it is advantageous for increasing the temperature of the second chamber and suppressing the freezing of the auxiliary machine in the second chamber. It is preferable that the approach heat insulating wall embeds the reforming water supply pipe. In this case, it is more advantageous for suppressing freezing of the reforming water supply pipe.

(Embodiment 1)
1 to 3 show a first embodiment. The fuel cell system according to the present embodiment is provided with (i) an evaporation unit 20 that vaporizes reformed water, and (ii) a fuel material that is provided so as to communicate with the evaporation unit 20. And (iii) a stack 1 formed of a solid oxide fuel cell that generates electricity with the anode gas and the cathode gas generated by the reforming unit 22. And (iv) a reformed water supply pipe 410 that forms a reformed water supply passage 41 for supplying reformed water to the evaporator 20, and (v) reforming the fuel material to be steam reformed via the evaporator 20. A fuel raw material supply pipe 510 that forms a fuel raw material supply passage 51 to be supplied to the mass portion 22, and (vi) a heat insulating wall 30 formed of a heat insulating material that covers the outside of the stack 1 and the evaporation portion 20 for heat insulation. . Although FIG. 1 shows the reformed water supply pipe 410 that forms the reformed water supply passage 41 for convenience, other pipes are not shown.

  The heat insulating wall 30, the stack 1, the reforming unit 22, and the evaporation unit 20 are integrally assembled and unitized, which is also called a fuel cell module. The reforming unit 22 is formed of a ceramic carrier that supports a reforming catalyst. The heat insulating wall 30 has wall portions 30a, 30b, 30c, and 30d formed of a heat insulating material in cross section, and has wall portions on the other surface (not shown). The wall portion 30 a of the heat insulating wall 30 has an inner surface 31 that faces the stack 1, the evaporation portion 20, and the reforming portion 22, and an outer surface 33 that faces away from the inner surface 31. The inner surface 31 has a storage chamber 34 for storing the stack 1. The heat insulating material is formed of a refractory material such as asbestos or ceramics. The refractory material may be brick.

  Here, when the outer diameter size of the reforming water supply pipe 410 is D, the distance LM between the outer peripheral surface of the reforming water supply pipe 410 and the outer peripheral surface of the fuel raw material supply pipe 510 is within 3 × D or 2 It is preferable that the reforming water supply pipe 410 and the fuel raw material supply pipe 510 are running in parallel inside the heat insulating wall 30 so as to be within × D. In this case, it is preferable that the reforming water supply pipe 410 and the fuel raw material supply pipe 510 are kept close to each other and capable of heat exchange. However, the present invention is not limited to this, and the reforming water supply pipe 410 and the fuel material supply pipe 510 may be separated from each other so as not to substantially exchange heat with each other.

  An outer box 200 that houses the stack 1, the evaporation unit 20, the reforming unit 22, and the heat insulating wall 30 is provided. The outer box 200 is (i) an upper chamber that houses the stack 1, the evaporator 20, the reformer 22, and the heat insulation wall 30 and receives heat from the stack 1, the evaporator 20, the reformer 22, and the heat insulation wall 30. A functioning first chamber 201; and (ii) a second chamber 202 that houses auxiliary equipment related to the power generation operation of the stack 1 and functions as a lower chamber whose temperature is lower than that of the first chamber 201 when the power generation operation is stopped. And a partition wall 203 that partitions the first chamber 201 and the second chamber 202. The heat insulating wall 30 is placed on the partition wall 203 via legs 30k. The auxiliary machine is a part other than the stack 1 required in the power generation operation of the stack 1, and is generally a part kept at 100 ° C. or less during the power generation operation of the stack 1. As auxiliary machines, pumps 42 and 55, valves, water purifier 40, tank 44, etc. are mentioned, for example.

  During the power generation operation of the stack 1, the fuel material pump 55 is driven, and the fuel material is supplied to the evaporation unit 20 of the reformer 2 through the fuel material supply passage 51 and supplied to the reforming unit 22 through the evaporation unit 20. Is done. Further, the reforming water pump 42 is driven, and the reforming water in the water storage tank 44 is supplied to the evaporator 20 through the reforming water passage 41. Here, the evaporating unit 20 steams the reformed water. The steam is supplied to the reforming unit 22. The reforming unit 22 steam reforms the fuel material to generate anode gas. The generated anode gas is supplied to the anode 11 of the fuel cell 1c constituting the stack 1 through the anode gas passage 14 and the anode gas manifold 13 and used for power generation. Since the cathode gas pump 62 is driven, the cathode gas is supplied to the cathode 12 of the stack 1 through the cathode gas supply passage 60 as the cathode gas. As a result, the stack 1 generates power. 1 and 2, the stack 1 is schematically shown. As shown in FIG. 3, the stack 1 is formed by arranging a plurality of fuel cells 1c in parallel via a passage 1x. The cathode gas flows along the passage 1x and is supplied to the cathode of the fuel cell 1c. The fuel cells 1c are electrically connected by a current collecting member (not shown).

  The anode off-gas and cathode off-gas after the power generation reaction are discharged to the combustion part 23 above the stack 1 to form a combustion flame 24 in the combustion part 23. The anode off-gas and cathode off-gas after combustion become combustion exhaust gas, and are discharged to the outside through an exhaust passage through a heat exchanger (not shown). The condensed water in which the moisture contained in the combustion exhaust gas is condensed is supplied to the water purifier 40 from the condensed water passage (not shown) derived from the heat exchanger and purified by the water purifier 40. The purified water is stored in the water storage tank 44 as reformed water.

  The wall portion 30a of the heat insulating wall 30 has an inner surface 31 and an outer surface 33 that extend substantially parallel to each other. The heat insulating wall 30 may be formed by coating a fiber, planar or block heat insulating material, and in short, it only needs to have heat insulating properties. In the wall portion 30 a of the heat insulating wall 30, the reforming water supply pipe 410 is running side by side so as to be substantially parallel to the inner surface 31 and the outer surface 33. As a result, as can be understood from FIG. 1, the reforming water supply pipe 410 enters the wall portion 30a directly from the lower surface portion 30u of the heat insulating wall 30 and is directed toward the evaporation portion 20 at the upper portion of the wall portion 30a. It is bent as a bent pipe 410p. In addition, the parallel running part currently running along the inner surface 31 and the outer surface 33 of the heat insulation wall 30 among the reforming water supply piping 410 is shown as parallel running piping 410m. Of the fuel raw material pipe supply pipe 510, a parallel running portion running in parallel along the inner surface 31 and the outer surface 33 is shown as a parallel running pipe 510m. Of the air pipe 29, a parallel running portion running side by side along the inner surface 31 and the outer surface 33 is shown as a parallel pipe 29 m. The parallel running pipes 29m, 410m, and 510m run parallel to each other inside the heat insulating wall 30.

  When the stack 1 stops the power generation operation, the temperature of the stack 1 and the reforming unit 22 gradually decreases from a high temperature state (for example, within a range of 500 to 900 ° C.) during the power generation operation. However, since the heat insulating wall 30 has high heat insulating properties, the temperature of the stack 1 and the reforming unit 22 is lower than the temperature at the time of power generation operation. For example, within the range of 1 hour to 240 hours, within the range of 3 hours to 100 hours, and within the range of 3 hours to 10 hours). In this case, when the power generation operation of the stack 1 is stopped, the temperature of the heat insulating wall 30 gradually decreases from the temperature during the power generation operation, but the temperature of the heat insulating wall 30 is maintained higher than the outside air temperature for a long time. The Here, as described above, the reforming water supply pipe 410 (particularly, the pipe portion existing in the first chamber 201 on the side near the evaporation unit 20 in the reforming water supply pipe 410) is basically insulated. While running parallel to the inner surface 31 and the outer surface 33 of the wall 30, it is embedded in the wall portion 30 a of the heat insulating wall 30.

  For this reason, even if it passes for a long time since the electric power generation stop of the stack 1, the heat insulation wall 30 has a residual heat. Due to this residual heat, the reformed water supply pipe 410 embedded in the heat insulating wall 30 can be maintained for a long time above the freezing start temperature. For example, even when the power generation operation of the stack 1 is stopped at night, the reforming water supply pipe 410 is kept warm for a long time beyond the freezing start temperature due to the residual heat of the heat insulating wall 30 until the next startup in the next morning. can do. For this reason, even when the reforming water remains in the reforming water supply pipe 410, freezing of the reforming water remaining in the reforming water supply pipe 410 can be suppressed over a long period of time in a cold region or in winter. The next activation of the stack 1 can be performed satisfactorily. Further, according to the present embodiment, as shown in FIG. 1, the fuel raw material supply pipe 510 is arranged inside the heat insulating wall 30 while the fuel raw material supply pipe 510 runs in parallel with the inner surface 31 and the outer surface 33 of the heat insulating wall 30. It is buried in. The fuel material supply pipe 510 is directed to the evaporation unit 20 at the upper part of the wall 30a while entering the wall 30a directly from the lower surface 30u of the heat insulating wall 30. For this reason, even when moisture adheres to the inner wall surface or the outer wall surface of the fuel raw material supply pipe 510, freezing of the fuel raw material supply pipe 510 is also suppressed by the residual heat of the heat insulating wall 30.

  By the way, when the stack 1 performs a power generation operation, the fuel material is supplied to the reforming unit 22 via the fuel material supply pipe 510. Similarly, when the stack 1 performs a power generation operation, the reforming water is supplied to the evaporation unit 20 via the reforming water supply pipe 410. Depending on the power generation conditions of the stack 1 and the conditions of the external environment, the reformed water flowing through the reformed water supply pipe 410 may be excessively heated due to the temperature of the stack 1 and the thermal effect of the combustion flame 24. . In this case, the reforming water flowing through the reforming water supply pipe 410 may be excessively boiled in the reforming water supply pipe 410, which is not preferable. In this regard, according to this embodiment, as shown in FIG. 2, the reformed water supply pipe 410 is connected to the fuel raw material supply pipe 510 in the direction of the arrow ta which is the thickness direction of the heat insulating wall 30 inside the heat insulating wall 30. And provided closer to the outer surface 33 side than the air pipe 29.

That is, the reforming water supply pipe 410 is further away from the fuel raw material supply pipe 510 and the air pipe 29 with respect to the stack 1 and the combustion flame 24 that become high temperature in the power generation operation. Therefore, the reforming water supply pipe 410 is further away from the fuel raw material supply pipe 510 and the air pipe 29 against the heat of the stack 1 and the combustion flame 24. Therefore, during the power generation operation of the stack 1, excessive reforming of the reforming water flowing through the reforming water supply pipe 410 before flowing into the evaporation unit 20 is suppressed. Note that the air pipe 29 supplies air for utilizing the heat of oxidation by oxidizing the fuel raw material with oxygen in the air by partial oxidation reforming at the time of startup. For this reason, depending on the activation mode of the stack 1, the air pipe 29 can be eliminated (the same applies to the following embodiments). Partial oxidation reforming is shown by the following reaction formula, and the start-up time can be shortened by utilizing the reaction exotherm. CH ₄ + 1 / 2O ₂ → 2H ₂ + CO
The hydrogen generated in this way is burned in the combustion section 23. Unreacted oxygen is supplied to the combustion unit 23 and used as a combustion support gas. According to the present embodiment, it is preferable that the reforming water supply pipe 410 and the fuel raw material supply pipe 510 are running in parallel while being close to each other so as to be able to exchange heat inside the heat insulating wall 30. In this case, during the power generation operation of the stack 1, when the temperature of the reforming water flowing through the reforming water supply pipe 410 is high, reforming of the gaseous fuel raw material flowing through the fuel raw material supply pipe 510 and the reforming water supply pipe 410 is performed. We can expect heat exchange with water. Therefore, before the reforming water flowing through the reforming water supply pipe 410 flows to the evaporation unit 20, it is advantageous for suppressing excessive boiling in the reforming water supply pipe 410.

  Further, as shown in FIG. 2, an air pipe 29 is provided for supplying the stack 1 with air that oxidizes the fuel material and generates heat of oxidation when the stack 1 is started. The air pipe 29 is directed to the evaporation unit 20 at the upper part of the wall 30a while entering the wall 30a directly from the lower surface 30u of the heat insulating wall 30. Here, air is supplied to the air pipe 29 only when the stack 1 is activated. When the stack 1 is normally generating power, no air is supplied to the air pipe 29. Here, as shown in FIG. 1, the air pipe 29 is embedded in the heat insulation wall 30 so that the air pipe 29 runs parallel to Houra parallel to the inner surface 31 and the outer surface 33 of the heat insulation wall 30. ing. For this reason, even after the power generation is stopped, the temperature of the air pipe 29 is also maintained above the freezing temperature for a long time. Therefore, even when moisture is attached to the air pipe 29, freezing of the air pipe 29 is also suppressed by the residual heat of the heat insulating wall 30. According to the present embodiment, the merge region XP of the air pipe 29, the reforming water supply pipe 410 and the fuel raw material supply pipe 510 is set inside the wall portion 30 a of the heat insulating wall 30. However, the present invention is not limited to this, and the air pipe 29, the reforming water supply pipe 410, and the fuel raw material supply pipe 510 may be combined in the evaporation section 20 without being combined in the wall section 30a. In some cases, the reforming water supply pipe 410 and the fuel raw material supply pipe 510 may be separated from each other within a predetermined distance without being close to each other within the heat insulating wall 30 so as to allow heat exchange.

(Embodiment 2)
FIG. 4 shows a second embodiment. This embodiment has the same configuration and the same function and effect as the above-described embodiment. The parallel running pipes 29m, 410m, and 510m run parallel to each other inside the heat insulating wall 30. From the inner surface 31 toward the outer surface 33 in the thickness direction of the heat insulating wall 30 (in the direction of the arrow ta), the parallel running pipe 510m of the fuel raw material supply pipe 510, the parallel running pipe 410m of the reforming water supply pipe 410, and the air pipe 29 The parallel running pipes 29m are arranged in this order. In this case, the parallel running pipe 410m of the reforming water supply pipe 410 is closer to the inner surface 31 than in the first embodiment. For this reason, even when the power generation operation of the stack 1 is stopped, heat is received from the stack 1, and the heat retaining property of the reforming water supply pipe 410 is secured, and the reforming water supply pipe is also used in a cold region or in winter. Freezing at 410 is suppressed. For this reason, even if a long time has elapsed since the stop of power generation in the stack 1, the reformed water supply pipe 410 can be kept warm for a long time beyond the freezing start temperature due to the residual heat of the heat insulating wall 30. For example, even when the power generation operation of the stack 1 is stopped at night, the reforming water supply pipe 410 is kept warm for a long time beyond the freezing start temperature due to the residual heat of the heat insulating wall 30 until the next startup in the next morning. can do. For this reason, even when the reforming water remains in the reforming water supply pipe 410, freezing of the reforming water remaining in the reforming water supply pipe 410 can be suppressed over a long period of time in a cold region or in winter. The next activation of the stack 1 can be performed satisfactorily.

  Further, as shown in FIG. 4, the reforming water supply pipe 410 is provided adjacent to the fuel raw material supply pipe 510 and the air pipe 29 inside the heat insulating wall 30 in the thickness direction of the heat insulating wall 30 (the direction of the arrow ta). Yes. That is, the reforming water supply pipe 410 and the fuel raw material supply pipe 510 are running parallel to each other while being close to each other so as to be able to exchange heat inside the heat insulating wall 30. Therefore, in the power generation operation of the stack 1, when the temperature of the reforming water flowing through the reforming water supply pipe 410 is high, the gaseous fuel material flowing through the fuel raw material supply pipe 510 and the reforming flowing through the reforming water supply pipe 410. Expect heat exchange with water. Therefore, in the power generation operation of the stack 1, it is advantageous for suppressing the boiling of the reforming water in the reforming water supply pipe 410 before the reforming water flowing in the reforming water supply pipe 410 flows into the evaporation unit 20.

(Embodiment 3)
FIG. 5 shows a third embodiment. This embodiment has the same configuration and the same function and effect as the above-described embodiment. The parallel running pipes 29m, 410m, and 510m run parallel to each other inside the heat insulating wall 30. The reforming water supply pipe 410 is inside the heat insulating wall 30, and the parallel running pipe 410 m of the reforming water supply pipe 410 is a fuel material supply pipe 510 via a heat transfer member 350 formed of a heat transfer material such as metal. The parallel running pipe 510m and the air pipe 29 are arranged next to the parallel running pipe 29m. As the heat transfer material, metals or ceramics (for example, aluminum nitride, silicon carbide, alumina) having good heat transfer properties are preferable. The heat transfer member 350 extends along the parallel running direction of the reforming water supply pipe 410 inside the heat insulating wall 30. In this case, the heat transfer areas of the reforming water supply pipe 410, the fuel material supply pipe 510, and the air pipe 29 are ensured. Even when the thermal power of the combustion flame 34 is strong, it is advantageous for suppressing boiling of the reformed water in the reformed water supply pipe 410. In this case, when the gaseous fuel material flows through the fuel material supply pipe 510 during the power generation operation of the stack 1, heat exchange with the reformed water flowing through the reforming water supply pipe 410 can be performed. Therefore, during the power generation operation of the stack 1, the gaseous fuel material flowing through the fuel material supply pipe 510 can be preheated upstream of the evaporation unit 20, and the reformed water flowing through the reforming water supply pipe 410 is supplied to the evaporation unit 20. This is advantageous in suppressing excessive boiling in the reforming water supply pipe 410 before flowing.

(Embodiment 4)
FIG. 6 shows a fourth embodiment. This embodiment has the same configuration and the same function and effect as the above-described embodiment. The reforming water supply pipe 410 is reformed inside the heat insulating wall 30 in a direction (arrow tc direction, a direction parallel to the inner surface 31 and the outer surface 33) intersecting the thickness direction (arrow ta direction) of the heat insulating wall 30. The water supply pipe 410 is adjacent to the fuel material supply pipe 510 and the air pipe 29. In this case, as can be understood from FIG. 6, it is advantageous for suppressing the thickness of the heat insulating wall 30. Here, the fuel material supply pipe 510 and the reforming water supply pipe 410 are close to each other so as to be able to exchange heat with each other. For this reason, when a gaseous fuel raw material flows into the fuel raw material supply pipe 510, heat exchange with the reformed water flowing through the reformed water supply pipe 410 is possible. Therefore, in the power generation operation of the stack 1, it is advantageous to suppress the reforming water flowing through the reforming water supply pipe 410 from boiling excessively in the reforming water supply pipe 410 before flowing into the evaporation unit 20.

  As shown in FIG. 6, the wall portion 30 a of the heat insulating wall 30 is divided into two in the thickness direction (arrow ta direction), and an inner layer 30 f having an inner surface 31 and an outer layer 30 s having an outer surface 33 are joined. Is formed. The inner layer 30f can have a groove 300x having a semicircular cross section for fitting the pipes 410, 510, 29 and the like. The outer layer 30s can have a groove 300x having a semicircular cross section for fitting the pipes 410, 510 and the like. However, the present invention is not limited to this, and the wall portion 30a of the heat insulating wall 30 may have an integral structure. Although not shown in FIG. 6, the reforming water supply pipe 410 is inside the heat insulating wall 30, and the reforming water supply pipe 410 is mutually connected via a heat transfer member formed of a heat transfer material such as metal. The fuel raw material supply pipe 510 and the air pipe 29 may be provided adjacent to each other so that heat can be exchanged.

(Embodiment 5)
FIG. 7 shows a fifth embodiment. This embodiment has the same configuration and the same function and effect as the above-described embodiment. In the thickness direction of the heat insulating wall 30 (arrow ta direction), the reforming water supply pipe 410, the fuel material supply pipe 510, and the air pipe 29 are arranged in this order from the inner surface 31 toward the outer surface 33. In this case, the reforming water supply pipe 410 is approaching the inner surface 31 of the heat insulating wall 30. For this reason, even when the power generation operation of the stack 1 is stopped, the reforming water supply pipe 410 receives heat from the stack 1 and the combustion unit 23 in a high temperature state. Therefore, even in a cold region or in winter, even when the power generation operation of the stack 1 is stopped, the temperature and heat retention of the reforming water supply pipe 410 are ensured for a long time. This can contribute to suppression of freezing of the reformed water remaining in the pipe 410. Even in this case, if a gaseous fuel material flows through the fuel material supply pipe 510 during the power generation operation of the stack 1, heat exchange with the reformed water flowing through the reforming water supply pipe 410 can be expected. Therefore, in the power generation operation of the stack 1, it is advantageous to suppress the reforming water flowing through the reforming water supply pipe 410 from boiling excessively in the reforming water supply pipe 410 before flowing into the evaporation unit 20.

(Embodiment 6)
FIG. 8 shows a sixth embodiment. This embodiment has the same configuration and the same function and effect as the above-described embodiment. In the thickness direction (arrow ta direction) of the heat insulating wall 30, the fuel material supply pipe 510, the reforming water supply pipe 410, and the air pipe 29 are arranged in this order from the inner surface 31 toward the outer surface 33. In this case, the reforming water supply pipe 410 is closer to the inner surface 31 of the heat insulating wall 30 than in the case of the first embodiment. For this reason, even when the power generation operation of the stack 1 is stopped, the reforming water supply pipe 410 can receive heat radiation from the stack 1 and the combustion unit 23. Therefore, the heat retaining property of the reforming water supply pipe 410 is ensured for a long time, which can contribute to the suppression of freezing of the reforming water remaining in the reforming water supply pipe 410.

  Even in this case, when a gaseous fuel material flows through the fuel material supply pipe 510 during the power generation operation of the stack 1, heat exchange with the reformed water flowing through the reforming water supply pipe 410 can be expected. Therefore, in the power generation operation of the stack 1, it is advantageous to suppress the reforming water flowing through the reforming water supply pipe 410 from boiling excessively in the reforming water supply pipe 410 before flowing into the evaporation unit 20. In particular, as shown in FIG. 8, in the wall portion 30 a of the heat insulating wall 30, the fuel raw material supply pipe 510 is disposed inside the reforming water supply pipe 410, so that the fuel raw material supply pipe 510 has a heat shielding action. Fulfill. Therefore, excessive temperature rise of the reforming water supply pipe 410 can be suppressed.

(Embodiment 7)
FIG. 9 shows a seventh embodiment. This embodiment has the same configuration and the same function and effect as the above-described embodiment. An outer box 200 that houses the stack 1, the evaporation unit 20, the reforming unit, and the heat insulating wall 30 is provided. The outer box 200 is (i) an upper chamber that houses the stack 1, the evaporator 20, the reformer 22, and the heat insulation wall 30 and receives heat from the stack 1, the evaporator 20, the reformer 22, and the heat insulation wall 30. The functioning first chamber 201 and (ii) auxiliary equipment related to the power generation operation of the stack 1 (for example, the water purifier 40 and the tank 44) are accommodated and the temperature is lower than that of the first chamber 201 when the power generation operation is stopped. A second chamber 202 that functions as a lower chamber; and (iii) a partition wall 203 that partitions the first chamber 201 and the second chamber 202.

  During the power generation operation of the stack 1 and when the power generation operation of the stack 1 is stopped, the first chamber 201 in which the stack 1 is accommodated tends to be hotter than the second chamber 202. The second chamber 202 tends to be cooler than the first chamber 201. For this reason, in cold regions or in winter, when the power generation of the stack 1 is stopped, the auxiliary machines (for example, the water purifier 40 and the tank 44) in the second chamber 202 may be frozen. Therefore, according to the present embodiment, as shown in FIG. 9, the heat insulating wall 30 has the entrance heat insulating wall 300. Since the heat insulating wall 300 is connected to the heat insulating wall 30, the heat insulating wall 300 receives heat from the heat insulating wall 30. The entrance heat insulating wall 300 can enter the second chamber 202 from the first chamber 201 and be exposed to the second chamber 202, and can release residual heat of the heat insulating wall 30 and the entrance heat insulating wall 300 to the second chamber 202. Here, the entrance heat insulating wall 300 is adjacent to the lower surface portion 30u of the heat insulating wall 30 so as to extend downward from the lower portion of the heat insulating wall 30 in the direction of gravity, and is exposed toward the second chamber 202. ing.

  Even when the stack 1 is shut down, the heat insulating wall 30 is maintained at a high temperature, and as a result, the heat of the incoming heat insulating wall 300 can be slowly released to the second chamber 202. Therefore, the temperature of the second chamber 202 is increased and the auxiliary machines (for example, the water purifier 40 and the tank 44) are frozen in the second chamber 202 as compared with the case where the insulative heat insulating wall 30 does not enter the second chamber 202. It is advantageous for suppressing the above. According to the present embodiment, since the reforming water supply pipe 410 is embedded in the entrance heat insulating wall 30, even if the power generation operation of the stack 1 is stopped in a cold region or winter, the reforming water supply pipe The temperature of 410 can be maintained above the freezing start temperature, and freezing of the reforming water supply pipe 410 can be suppressed.

(Embodiment 8)
FIG. 10 shows an eighth embodiment. This embodiment has the same configuration and the same function and effect as the above-described embodiment. As shown in FIG. 10, the reforming water supply pipe 410 and the fuel raw material supply pipe 510 have a double winding double pipe structure. In the double winding double pipe structure, the reforming water supply pipe 410 is concentrically arranged on the inner side, and the fuel raw material supply pipe 510 is concentrically arranged on the outer side. For this reason, in the power generation operation of the stack 1, when a gaseous fuel material flows through the fuel material supply pipe 510, heat exchange with the reformed water flowing through the reforming water supply pipe 410 can be performed efficiently. Therefore, when the stack 1 is in a power generation operation, it is advantageous for suppressing the reforming water flowing through the reforming water supply pipe 410 from boiling excessively in the reforming water supply pipe 410 before flowing into the evaporation unit 20. is there. Furthermore, it can be expected that the gaseous fuel material flowing through the fuel material supply pipe 510 is preheated.

(Embodiment 9)
FIG. 11 shows a ninth embodiment. This embodiment is applied to a solid oxide fuel cell system. FIG. 11 shows the concept of a solid oxide fuel cell system. The present embodiment employs a method in which the air pipe (not shown), the reforming water supply pipe 410 and the fuel raw material supply pipe 510 are joined at the evaporation part 20 without joining at the wall part 30a. As shown in FIG. 11, the fuel cell system basically includes a solid oxide stack 1, a reformer 2, a control unit 100, and a housing 9. Further, the fuel cell system includes a reforming water system 4, a fuel material supply system 5, a cathode gas supply thread 6, and a hot water storage system 7 inside the housing 9.

As shown in FIG. 11, the stack 1 includes an anode that functions as a fuel electrode to which anode gas is supplied, a cathode that functions as an oxidant electrode to which cathode gas is supplied, and a solid oxide sandwiched between the anode and the cathode. And an electrolyte membrane (not shown). The solid oxide has a property of conducting oxygen ions (O ²⁻ ), and examples thereof include zirconia type such as YSZ and lanthanum gallate type. The anode is exemplified by nickel-ceria cermet. Examples of the cathode include samarium cobaltite and lanthanum manganite. The material is not limited to the above. An anode gas manifold 13 that guides the anode gas to the inlet of the stack 1 is disposed at the bottom of the stack 1. A signal from the first temperature sensor 101 that detects the temperature of the stack 1 is input to the control unit 100.

As shown in FIG. 11, the reformer 2 includes an evaporation unit 20 and a reforming unit 22 to which a fuel material is supplied. The evaporator 20 vaporizes the liquid phase reformed water supplied from the reforming water system 4 to the evaporator 20. The reforming unit 22 is provided downstream of the evaporation unit 20 and steam-reforms the fuel material with the steam generated by the evaporation unit 20 to generate anode gas. The anode gas is hydrogen gas or hydrogen-containing gas. The housing 9 that functions as an outer box has a housing chamber 91 and an outside air intake port 92 that allows the housing chamber 91 and the outside air to communicate with each other. The fuel cell module 3 is housed inside the housing 9 that functions as an outer box. It has a container-like heat insulating wall 30 formed of a heat insulating material, and the stack 1 and the reformer 2 are accommodated inside the heat insulating wall 30 via the combustion section 23. The heat insulating wall 30 has a shell shape and includes wall portions 30a, 30b, 30c, and 30d. The heat insulating wall 30 may be formed by coating a fiber, planar or block heat insulating material, and in short, it only needs to have heat insulating properties.

  In the fuel cell module 3, the reformer 2 (the reforming unit 22 and the evaporation unit 20) is disposed above the stack 1. In the fuel cell module 3, a combustion unit 23 is formed between the stack 1 and the reformer 2 (the reforming unit 22 and the evaporation unit 20). In particular, a combustion part 23 is formed between the upper part of the stack 1 and the lower part of the reformer 2 (the reforming part 22 and the evaporation part 20). The anode off gas after the power generation reaction is discharged from the anode 11 of the stack 1 to the combustion unit 23. The cathode off gas after the power generation reaction is discharged from the cathode 12 of the stack 1 to the combustion unit 23. The anode off gas is a gas after power generation of the anode gas, and can be burned containing unreacted hydrogen (combustible component). Cathode off-gas is a gas after the cathode gas is generated and contains unreacted oxygen. The anode off gas discharged to the combustion unit 23 is burned by the cathode off gas (corresponding to combustion air), and a combustion flame 24 is formed in the combustion unit 23. The anode off-gas and cathode off-gas that form the combustion flame 24 in the combustion section 23 become combustion exhaust gas. The combustion flame 24 in the combustion unit 23 heats both the reforming unit 22 and the evaporation unit 20 and maintains the temperature of the reforming unit 22 in the reforming reaction temperature region.

  As shown in FIG. 11, the reforming water system 4 supplies reforming water that is consumed as steam in steam reforming in the reforming unit 22 to the reforming unit 22, and includes a water purifier 40 and a reformer. 2, a reforming water passage 41, a reforming water pump 42 (reforming water transport source), and a water supply valve 43. The water purifier 40 includes a water purification material 40a such as an ion exchange resin that can purify water. The reforming water passage 41 is provided with a water storage tank 44, a reforming water pump 42, and a water supply valve 43.

  As shown in FIG. 11, the fuel raw material supply system 5 includes a fuel raw material supply passage 51 connected to the fuel source 50 for supplying a hydrocarbon-based fuel raw material to the reformer 2, an inlet valve 52, and a flow meter 53. And a desulfurizer 54 and a fuel material pump 55 (fuel material conveyance source). In the fuel material supply passage 51, an inlet valve 52, a flow meter 53, a desulfurizer 54, and a fuel material pump 55 are provided. The cathode gas supply yarn 6 includes a cathode gas supply passage 60 that supplies a cathode gas that is air to the cathode 12 of the stack 1, a dust filter 61, a cathode gas pump 62 (cathode gas transport source), and a flow meter 63. . A dust filter 61, a cathode gas pump 62, and a flow meter 63 are disposed in the cathode gas supply passage 60. The dust filter 61 is disposed in the housing chamber 91 of the housing 9.

  When the cathode gas pump 62 is driven, outside air flows into the housing chamber 91 from the outside air inlet 92 and is supplied to the cathode 12 from the inlet of the stack 1 as cathode gas through the dust filter 61 and the cathode gas supply passage 60. A second temperature sensor 102 that detects the temperature of the outside air (cathode gas) taken in from the outside air inlet 92 is provided in the vicinity of the outside air inlet 92 of the housing 9. The second temperature sensor 102 detects the temperature of the cathode gas before being supplied to the cathode 12 of the stack 1, and substantially detects the outside air temperature outside the housing 9. A signal from the second temperature sensor 102 is input to the control unit 100.

  As shown in FIG. 11, the hot water storage system 7 includes a circulation passage 71 that circulates through the heat exchanger 74 and the hot water storage tank 70, and a hot water storage pump 72 (a hot water supply source) provided in the circulation passage 71. When the hot water storage pump 72 is activated, the water in the hot water storage tank 72 is supplied from the circulation passage 71 to the heat exchanger 74 and heated by heat exchange with the combustion exhaust gas in the heat exchanger 64. The heated water returns to the hot water storage tank 70. Thereby, the hot water storage tank 70 stores hot water. A heat exchanger 64 is provided in the vicinity of the fuel cell module 3. The heat exchanger 74 has a gas passage 74g through which combustion exhaust gas discharged from the fuel cell module 3 passes and a water passage 74w through which water in the circulation passage 71 of the hot water storage system 7 passes. The heat of the combustion exhaust gas flowing through the heat exchanger 74 is transmitted to the water in the circulation passage 71 of the hot water storage system 7. An exhaust passage 75 extends from the gas passage 74 g of the heat exchanger 74 toward the exhaust port 76 of the housing 9, and the combustion exhaust gas is exhausted from the exhaust port 76 through the exhaust passage 75. A condensed water passage 77 extends from the gas passage 74 g of the heat exchanger 74 toward the water purifier 40. Accordingly, the water vapor in the vapor phase contained in the combustion exhaust gas is cooled in the heat exchanger 74 to generate condensed water. The condensed water is supplied from the condensed water passage 77 to the water purifier 40.

  Before starting the power generation operation of the stack 1, the fuel material pump 55 is driven, and the fuel material is supplied to the stack 1 via the desulfurizer 54, the fuel material supply passage 51, the evaporation unit 20, and the reforming unit 22, It is supplied to the combustion unit 23 via the stack 1. Further, since the cathode gas pump 62 is driven, cathode gas (air) is supplied to the combustion unit 23 via the cathode 12 of the stack 1. As a result, the combustible fuel material is burned by the cathode gas (air) in the combustion section 23, and a combustion flame 24 is formed in the combustion section 23. The combustion flame 24 heats the reforming unit 22 and the evaporation unit 20 to a high temperature to enable a reforming reaction.

Next, during the power generation operation of the stack 1, the fuel material pump 55 is driven, and the fuel material is supplied to the evaporation unit 20 of the reformer 2 through the fuel material supply passage 51. Further, the reforming water pump 42 is driven, and the reforming water in the water storage tank 44 is supplied to the evaporator 20 through the reforming water passage 41. Here, since the evaporation unit 20 is heated, the evaporation unit 20 vaporizes the reformed water. The steam is supplied to the reforming unit 22. The reforming unit 22 steam reforms the fuel material to generate anode gas. When the fuel raw material is methane-based, it is considered that the generation of the anode gas in the steam reforming is based on the following equation (1). In the solid oxide stack 1, CO can be used as fuel in addition to H ₂ .

(1) ... CH ₄ + 2H ₂ O → 4H ₂ + CO ₂
CH ₄ + H ₂ O → 3H ₂ + CO
The generated anode gas is supplied to the inlet of the anode 11 of the stack 1 through the anode gas passage 14 and the anode gas manifold 13 and used for power generation. Since the cathode gas pump 62 is driven, outside air outside the housing 9 is supplied as cathode gas to the inlet of the cathode 12 of the stack 1 through the dust filter 61 and the cathode gas supply passage 60. As a result, the stack 1 generates power.

In the power generation reaction, it is considered that the reaction (2) basically occurs at the anode 11 supplied with the hydrogen-containing gas. It is considered that the reaction (3) basically occurs at the cathode 12 to which oxygen is supplied. Oxygen ions (O ²⁻ ) generated at the cathode 12 conduct the electrolyte from the cathode 12 toward the anode 11.

(2) ... H ₂ + O ²⁻ → H ₂ O + 2e ⁻
When CO is contained, CO + O ²⁻ → CO ₂ + 2e ⁻
(3)... 1 / 2O ₂ + 2e ⁻ → O ²⁻
The anode off-gas and cathode off-gas after the power generation reaction are discharged to the combustion part 23 above the stack 1 to form a combustion flame 24 in the combustion part 23. The burned anode off-gas and cathode off-gas become combustion exhaust gas, and are discharged to the outside of the housing 9 from the exhaust port 76 at the tip of the exhaust passage 75 through the heat exchanger 74 and the relief valve 78. The condensed water in which the moisture contained in the combustion exhaust gas is condensed is supplied to the water purifier 40 from the condensed water passage 77 led out from the heat exchanger 74 and purified by the water purifier 40. The purified water is stored in the water storage tank 44 as reformed water 44w.

  As described above, the anode off-gas is discharged from the upper part of the anode 11 of the stack 1 to the combustion unit 23, the cathode off-gas discharged from the cathode 12 is discharged to the combustion unit 23, and the anode off-gas is burned by the cathode off-gas. And the reforming unit 22 and the evaporation unit 20 are heated.

  Accordingly, the flow rate of the anode gas (fuel material) is set to a flow rate obtained by adding the flow rate used in the power generation reaction in the anode 11 of the stack 1 and the flow rate at which the anode off gas forms the combustion flame 24 in the combustion unit 23. ing. As the flow rate of the cathode gas, the flow rate used in the power generation reaction at the cathode 12 of the stack 1, the flow rate at which the cathode off-gas forms the combustion flame 24 as combustion air in the combustion unit 23, and the surplus flow rate are added. The flow rate is set.

  According to the system in which the solid oxide stack 1 is mounted, the operating temperature of the stack 1 during rated operation is in the range of 400 to 1100 ° C and in the range of 500 to 800 ° C.

  Also in this embodiment, even if a long time has elapsed since the power generation stop of the stack 1, the reforming water supply pipe 410 can be kept warm for a long time beyond the freezing start temperature due to the residual heat of the heat insulating wall 30. For example, even when the power generation operation of the stack 1 is stopped at night, the reforming water supply pipe 410 is kept warm for a long time beyond the freezing start temperature due to the residual heat of the heat insulating wall 30 until the next startup in the next morning. can do. For this reason, even when the reforming water remains in the reforming water supply pipe 410, freezing of the reforming water remaining in the reforming water supply pipe 410 can be suppressed over a long period of time in a cold region or in winter. The next activation of the stack 1 can be performed satisfactorily.

(Other)
The present invention is not limited to the embodiments described above and shown in the drawings, and can be implemented with appropriate modifications within the scope not departing from the gist. The stack 1 has a flat plate laminated structure formed by assembling flat plate anodes and cathodes, but is not limited to this and may be a tube type. The electrolyte of the fuel cell is not limited to the solid oxide form, but may be a phosphoric acid form or a molten carbonate form. The following technical idea can be grasped from the above description.

  [Additional Item 1] An evaporation section that is heated by a heating element to vaporize the reforming water, and is provided so as to communicate with the evaporation section and to be heated by the heating element. A reforming unit that reforms the raw material with steam to generate anode gas, a fuel cell that generates electricity with the anode gas and cathode gas generated in the reforming unit, and a reforming water supply that supplies reforming water to the evaporation unit Formed with piping, fuel material supply piping for supplying steam reformed fuel material to the reforming section, and at least the outside of the fuel cell and reforming section for heat insulation And a heat insulation wall having an outer surface. Heat dissipation from the fuel cell is suppressed.

  The present invention can be used in, for example, fuel cell systems for stationary use, vehicles, electronic equipment, and electrical equipment.

  1 is a stack, 2 is a reformer, 20 is an evaporation section, 22 is a reforming section, 23 is a combustion section, 24 is a combustion flame, 29 is an air pipe, 3 is a fuel cell module, 30 is a heat insulation wall, and 31 is an inner side Surface, 33 is an outer surface, 4 is a reforming water system, 40 is a water purifier (auxiliary machine), 41 is a reforming water supply passage, 410 is a reforming water supply pipe, 410m is a parallel running pipe, and 42 is reforming water. Pump, 44 is a water supply tank (auxiliary machine), 5 is a fuel material supply system, 51 is a fuel material supply passage, 510 is a fuel material supply pipe, 55 is a fuel material pump, 6 is a cathode gas supply system, and 60 is a cathode gas supply The passage, 62 is a cathode gas pump, 7 is a hot water storage system, 70 is a hot water storage tank, 71 is a circulation passage, 72 is a hot water storage pump, 74 is a heat exchanger, 75 is an exhaust passage, 76 is an exhaust port, 92 is an outside air intake port, 100 is the control unit, 200 is the outer box, 201 is the first chamber, 2 2 is a second chamber, 203 partitioning wall, 300 denotes ingress insulating wall.

Claims (4)

An evaporation section that is heated by a combustion flame and steams the reformed water;
A reforming unit provided to communicate with the evaporation unit and to be heated by a combustion flame, and reforming the fuel material with water vapor generated in the evaporation unit to generate an anode gas;
A fuel cell that generates electricity with the anode gas and the cathode gas generated in the reforming section;
A reforming water supply pipe for supplying reforming water to the evaporation section;
A fuel material supply pipe for supplying the fuel material to be reformed with steam to the reforming unit;
A heat insulating wall that is formed of a heat insulating material that covers at least the outside of the fuel cell and the reforming part for heat insulation, and has an inner surface and an outer surface facing away from the inner surface;
The heat insulating wall is embedded in the heat insulating wall while running the reforming water supply pipes side by side on the inner surface and the outer surface of the heat insulating wall, and due to residual heat of the heat insulating wall when the power generation operation is stopped. A fuel cell system for keeping the reformed water supply pipe warm ,
An outer box that houses the fuel cell, the evaporation section, the reforming section and the heat insulating wall is provided;
The outer box houses the fuel cell, the evaporation unit, the reforming unit, and the heat insulation wall, and receives a heat radiation from the fuel cell, the evaporation unit, the reforming unit, and the heat insulation wall; A second chamber that houses auxiliary equipment related to the power generation operation of the fuel cell and has a temperature lower than that of the first chamber when the power generation operation is stopped; and a partition wall that partitions the first chamber and the second chamber Have
The heat insulating wall includes a heat insulating wall that enters the second chamber from the first chamber, is exposed to the second chamber, and discharges residual heat to the second chamber.   2. The fuel cell system according to claim 1, wherein the approach heat insulating wall embeds the reforming water supply pipe. 3. The fuel cell system according to claim 1, wherein the heat insulating wall is embedded in the heat insulating wall while running the fuel material supply pipes in parallel on the inner surface and the outer surface of the heat insulating wall. In any 1 paragraph of Claims 1-3 , the air piping which supplies the fuel cell with the air which oxidizes the fuel material at the time of starting of the fuel cell and generates oxidation heat is provided,
The said heat insulation wall is a fuel cell system which is embed | buried in the said heat insulation wall, making the said air piping run along the said inner surface and the said outer surface of the said heat insulation wall.

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