JP5584022B2 - Fuel cell system and starting method thereof - Google Patents

Description

  The present invention relates to a fuel cell system and a method for starting the fuel cell system, and in particular, a fuel capable of raising the temperature of the fuel cell system while preventing the anode of the solid oxide fuel cell from being oxidized and deteriorated. The present invention relates to a battery system activation method.

  In general, in a fuel cell system, in order to prevent the anode of a solid oxide fuel cell from being oxidized, a temperature range (where the anode side needs to maintain a reduced state at the start of temperature rising of the solid oxide fuel cell ( At about 400 ° C. or higher), it is necessary to maintain the anode in an atmosphere of an inert gas or a reducing gas. In a fuel cell system, a reformer is usually used to produce a reformed gas containing hydrogen as a main component for power generation. In this case, from the reformer to a solid oxide fuel cell. In order to supply the reformed gas, it is first necessary to raise the temperature to a temperature at which the reformer can perform the reforming reaction.

  In Japanese Patent Application Laid-Open No. 2005-285621 (Patent Document 1), gas discharged from a fuel cell is combusted, and both the reformer and the fuel cell are heated by this combustion heat, and the reformer is reformed. Before reaching the reaction start temperature, a method for supplying steam reformed by the combustion heat to the reformer has been proposed. Japanese Patent Laying-Open No. 2005-293951 (Patent Document 2) discloses a fuel cell system including two types of reformers, a reformer using a steam reforming reaction and a reformer using a partial oxidation reforming reaction. Have proposed a method of switching the reformer used during the power generation start period and the power generation stop period during the power generation of the solid oxide fuel cell. Furthermore, in JP 2008-16277 A (Patent Document 3), in addition to the internal reformer installed in the container of the solid oxide fuel cell, on the outside of the container of the solid oxide fuel cell, By installing an external reformer equipped with a combustible material combustion means, the reformed gas produced by the external reformer is converted to a solid oxide fuel before the internal reformer reaches a reformable temperature. When the battery reaches the temperature at which the internal reformer can be reformed, the reformed gas produced by the external reformer is stopped and the reformed gas produced by the internal reformer is used as a solid oxide fuel cell. There has been proposed a fuel cell system that can be supplied to a vehicle.

JP 2005-285621 A JP 2005-293951 A JP 2008-16277 A

  However, even if an inert gas such as nitrogen gas is flowed to the anode of the solid oxide fuel cell or water vapor is flowed to the reformer, a small amount of oxygen can be mixed into the anode of the solid oxide fuel cell. Therefore, it is not sufficient as a means for preventing the anode of the solid oxide fuel cell from being oxidized. Although flowing a reducing gas such as hydrogen gas is effective as a means for preventing oxidation of the anode, a reformed gas containing hydrogen as a power generation fuel is supplied from the reformer to the fuel cell. It is not preferable to separately provide a hydrogen gas supply unit different from the quality gas supply unit because it complicates the fuel cell system and causes a cost increase. Therefore, when the solid oxide fuel cell system is started up, there is no need to provide a means for supplying hydrogen gas to the solid oxide fuel cell in addition to the reformed gas supply means. The problem is whether to prevent oxidation of the anode.

  Accordingly, an object of the present invention is to provide a fuel cell system capable of raising the temperature of the fuel cell system while preventing the anode of the solid oxide fuel cell from being oxidized and deteriorated, and a method for starting the fuel cell system. There is to do.

  As a result of intensive studies to achieve the above object, the present inventors have reformed at a temperature higher than the temperature at which the steam reforming reaction can be started before the solid oxide fuel cell is heated above the temperature at which the anode is oxidized. In addition to the reformed gas supply means for supplying the reformed gas from the reformer to the fuel cell by starting the supply of the reformed gas having reducibility from the reformer to the anode by heating the reformer, hydrogen gas It has been found that oxidation of the anode of a solid oxide fuel cell can be prevented without installing a supply means, and the present invention has been completed.

That is, the fuel cell system of the present invention is
A solid oxide fuel cell;
A reformer for reforming raw fuel to produce reformed gas;
First combustion means for burning at least one fuel selected from the group consisting of hydrocarbons and aliphatic alcohols to heat the reformer;
Second combustion means for combusting anode off-gas from the solid oxide fuel cell to heat the reformer;
Combustion gas exposure prevention means for preventing the solid oxide fuel cell from being exposed to combustion gas generated by at least one of the first combustion means and the second combustion means;
A water evaporator located downstream of the reformer in the flow direction of the combustion gas, and a water evaporator which generates steam by heat exchange with the combustion gas,
The combustion gas exposure preventing means, the first combustion means and the second combustion means and said housing der Rukoto surrounding the reformer.

  In a preferred embodiment of the fuel cell system of the present invention, the solid oxide fuel cell is at least one means selected from the group consisting of the first combustion means, the second combustion means, and the combustion gas exposure prevention means. Is heated by at least one of heat conduction and heat radiation.

  In another preferred embodiment of the fuel cell system of the present invention, the fuel cell system further includes a heat exchanger that heats the oxygen-containing gas supplied to the solid oxide fuel cell by heat exchange with the combustion gas.

  In another preferred embodiment of the fuel cell system of the present invention, before producing the reformed gas, the fuel cell system further comprises a desulfurizer that desulfurizes the raw fuel to obtain a desulfurized raw fuel, and is heated by the heat exchanger. The desulfurizer is heated using a part of the contained gas.

  In another preferred embodiment of the fuel cell system of the present invention, the fuel cell system further includes a bypass flow path for avoiding a part of the oxygen-containing gas supplied to the solid oxide fuel cell from heating by the heat exchanger. .

Further, the start method of the fuel cell system of the present invention is the start method of the fuel cell system,
Combusting at least one fuel selected from the group consisting of hydrocarbons and aliphatic alcohols to generate a combustion gas, and heating the reformer using the combustion gas, the solid oxidation of the combustion gas A step of preventing the physical fuel cell from being exposed;
Heating a water evaporator located downstream of the reformer in the flow direction of the combustion gas with the combustion gas to generate water vapor;
After the temperature of the water evaporator reaches a temperature at which steam can be generated or higher, and the temperature of the reformer reaches a temperature at which the reforming reaction of raw fuel can be performed, the reforming is performed. Supplying the steam and raw fuel to a mass device to start a reforming reaction and generating a reformed gas;
Supplying the reformed gas to the anode of the solid oxide fuel cell before the temperature of the solid oxide fuel cell reaches a temperature at which the anode of the solid oxide fuel cell oxidizes. It is characterized by that.

In a preferred example of the starting method of the fuel cell system of the present invention,
Heating the oxygen-containing gas supplied to the solid oxide fuel cell by heat exchange with the combustion gas in a heat exchanger located downstream of the reformer in the flow direction of the combustion gas; ,
And a step of heating a desulfurizer using a part of the heated oxygen-containing gas to desulfurize the raw fuel supplied to the reformer to obtain a desulfurized raw fuel.

  In another preferred embodiment of the method for starting the fuel cell system of the present invention, an oxygen-containing gas that does not exchange heat with the combustion gas is prepared from the oxygen-containing gas supplied to the solid oxide fuel cell. And supplying the oxygen-containing gas to the solid oxide fuel cell.

  In another preferred embodiment of the method for starting the fuel cell system of the present invention, the method further includes a step of introducing an oxidizing gas containing oxygen into the reformer to perform a partial oxidation reaction.

  According to the fuel cell system of the present invention, a solid oxide fuel cell, a reformer, a first combustion means, a second combustion means, a combustion gas exposure prevention means, and a water evaporator are provided. The temperature of the fuel cell system can be raised while preventing the anode of the fuel cell from being oxidized and deteriorated.

  According to the starting method of the fuel cell system of the present invention, in particular, when the reformer is heated using the combustion gas, by preventing the solid oxide fuel cell from being exposed to the combustion gas, The reformed gas can be supplied to the anode of the solid oxide fuel cell before the temperature of the solid oxide fuel cell reaches the temperature at which the anode of the solid oxide fuel cell oxidizes. The temperature of the fuel cell system can be raised while preventing the anode of the fuel cell from being oxidized and deteriorated.

It is the schematic which shows an example of the fuel cell system of this invention. It is the schematic which shows an example of the suitable reformer for the fuel cell system of this invention. It is the schematic which looked at the reforming apparatus shown in FIG. 2 from the left side. It is a fragmentary sectional view of the reformer shown in FIG. It is the partial schematic which shows the other example of the fuel cell system of this invention.

  Hereinafter, the fuel cell system of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic view showing an example of a fuel cell system of the present invention. The fuel cell system shown in FIG. 1 is selected from the group consisting of a solid oxide fuel cell 1, a reformer 2 that reforms raw fuel to produce a reformed gas, and a hydrocarbon and an aliphatic alcohol. First combustion means 3 for burning at least one type of fuel to heat the reformer 2 and second for burning the anode off-gas from the solid oxide fuel cell 1 to heat the reformer 2 Combustion gas exposure prevention for preventing the solid oxide fuel cell 1 from being exposed to the combustion gas generated by the combustion means 4 and at least one of the first combustion means 3 and the second combustion means 4 Means 5 and a water evaporator 6 located downstream of the reformer 2 in the flow direction of the combustion gas, the water evaporator 6 generating steam by heat exchange with the combustion gas. Features.

  In the illustrated fuel cell system, the solid oxide fuel cell 1 is not particularly limited, and a solid oxide fuel cell having a known structure can be adopted. In general, the solid oxide fuel cell 1 is generally configured by stacking and / or connecting a plurality of cells. The solid oxide fuel cell is usually operated at a high temperature of 700 to 800 ° C.

In the illustrated fuel cell system, the reformer 2 is for reforming raw fuel to produce reformed gas containing hydrogen. For example, the reformer 2 is filled with a known reforming catalyst. A vessel body is provided. Specifically, a known reformer such as a steam reformer or an oxidation autothermal reformer (ATR) can be used as the reformer 2. Here, as the reforming catalyst, a catalyst in which Ru, Ni, W, Co, Rh, Pt or the like is supported on a support such as alumina, silica, zirconia, or the like can be used. The raw fuel is not particularly limited, but is a gas hydrocarbon fuel such as methane, ethane, propane, or butane, a liquid hydrocarbon fuel such as light oil, gasoline, naphtha, or kerosene, or an aliphatic alcohol fuel such as methanol or ethanol. Can be used. The reforming conditions include, for example, a liquid hydrocarbon fuel supply amount (LHSV) as a raw fuel: 0.1 to 10 hr ⁻¹ , a molar ratio of steam and carbon contained in the raw fuel (steam / carbon ratio): 2 It is preferably 4 mol / mol, reaction pressure: atmospheric pressure to less than 1.0 MPa, and reaction temperature: 400 to 800 ° C.

  In the illustrated fuel cell system, the first combustion means 3 is a combustion means for heating the reformer 2 by burning at least one fuel selected from the group consisting of hydrocarbons and aliphatic alcohols. At the start of the fuel cell system, the reformer is heated to a temperature at which the reforming reaction can be started before the solid oxide fuel cell is heated above the temperature at which the anode is oxidized. It is desired to start supply of reformed gas having reducibility from the anode to the anode, and by installing the first combustion means in the fuel cell system, the reformer can be heated quickly. For example, a known combustion device such as a burner can be used as the first combustion means. Although not particularly limited, as the hydrocarbon fuel, a gas hydrocarbon fuel such as methane, ethane, propane, butane, LP gas, or a liquid hydrocarbon fuel such as light oil, gasoline, naphtha, kerosene, or the like is used. As the aliphatic alcohol fuel, methanol, ethanol or the like can be used.

  In the fuel cell system of the illustrated example, the second combustion means 4 is a combustion means for heating the reformer 2 by burning the anode offgas from the solid oxide fuel cell 1, and the anode offgas supply means 7 A cathode off-gas supply means 8. Here, according to the second combustion means, the combustion gas of the anode off gas supplied by the anode off gas supply means can be generated by using the cathode off gas supplied by the cathode off gas supply means as the combustion supporting gas. it can. In the fuel cell system of the present invention, the anode off-gas and cathode off-gas of the fuel cell are used, so that the utilization efficiency of the fuel cell exhaust heat is high. Further, if the reformer can be heated by the second combustion means, the first combustion means can be stopped, so that the use of the first combustion means can be limited at the time of starting the fuel cell system. . Thereby, the fuel consumption of a fuel cell system can be reduced.

  As the anode off-gas supply means 7 of the second combustion means, an anode off-gas supply passage connected to the anode of the solid oxide fuel cell 1 is used to supply the anode off-gas of the fuel cell as described above. preferable. Further, as the cathode offgas supply means 8 of the second combustion means, for example, as shown in FIG. 1, a cathode connected to the cathode of the solid oxide fuel cell 1 to supply the cathode offgas of the fuel cell. An off-gas supply channel can be used. Note that the anode off-gas and the cathode off-gas are discharged from their supply means to form combustion gas.

  In the fuel cell system of the present invention, at least one of the anode offgas supplied from the anode offgas supply means and the cathode offgas supplied from the cathode offgas supply means is preferably a high temperature, specifically 500 ° C. or higher. . If the anode off-gas and the cathode off-gas are mixed and the temperature is high, that is, about 500 ° C. or higher, spontaneous ignition occurs, so that it is not necessary to install an ignition device or the like for generating combustion gas.

  The fuel utilization rate of the fuel cell system is generally 60 to 80%, and about 20 to 40% of the fuel is discharged as the anode off gas. Therefore, sufficient anode off gas used in the fuel cell system of the present invention should be secured. Can do. Further, the utilization rate of oxygen-containing gas in the fuel cell is generally 20 to 40%, and about 60 to 80% of the supplied oxygen-containing gas is discharged as the cathode off-gas. Therefore, the cathode off-gas used in the fuel cell system of the present invention. Can be secured sufficiently.

  In the fuel cell system of the illustrated example, the combustion gas exposure prevention means 5 is such that the solid oxide fuel cell 1 is exposed to the combustion gas generated by at least one of the first combustion means 3 and the second combustion means 4. It is a means for preventing this. Here, according to the combustion gas exposure prevention means, since the combustion gas generated by the combustion means is not directly supplied to the solid oxide fuel cell, the solidification is performed before the reformer reaches a temperature at which the reforming reaction can be started. It is possible to prevent the oxide fuel cell from reaching the oxidation temperature of the anode. In other words, before the solid oxide fuel cell is heated above the temperature at which the anode oxidizes, the reformer is heated to a temperature above the temperature at which the reforming reaction can be started to reform gas from the reformer to the anode. Therefore, it is possible to raise the temperature of the fuel cell system while preventing the anode of the solid oxide fuel cell from being oxidized and deteriorated.

As the combustion gas exposure preventing means, for example, using a housing enclosing the first combustion unit as shown in FIG. 2, the second combustion unit and the reformer. Also, from the viewpoint of transferring heat from the combustion gas exposure prevention means to the solid oxide fuel cell by at least one of conduction and radiation, and performing heat transfer between the solid oxide fuel cell and the reformer. The material used for the combustion gas exposure prevention means is preferably a metal such as stainless steel or nickel alloy. The illustrated fuel cell system includes a housing (hereinafter also referred to as a first housing) 9 that covers at least the solid oxide fuel cell 1 and the reformer 2, and the housing 9 and the combustion gas exposure prevention means 5 are provided. By forming a space with the partition walls, the reformer 2 can be effectively heated in the space.

  In the fuel cell system of the present invention, the solid oxide fuel cell has heat conduction and heat radiation from at least one means selected from the group consisting of first combustion means, second combustion means and combustion gas exposure prevention means. It is preferable to be heated by at least one of the above. As a result, the temperature of the solid oxide fuel cell can be raised while heating the reformer, and the fuel cell system can be started up effectively in a short time. In addition, as a material used for a 1st combustion means and a 2nd combustion means, it is preferable to use metals, such as stainless steel and a nickel alloy, from a viewpoint similar to a combustion gas exposure prevention means.

  In the fuel cell system of the illustrated example, the water evaporator 6 is located downstream of the reformer 2 in the flow direction of the combustion gas, and steam for use in the reforming reaction with the raw fuel is heated with the combustion gas. It is generated by replacement, and a known water evaporator can be used. In the illustrated fuel cell system, water for vaporization to water vapor is supplied from the water tank 12 to the water evaporator 6 using the water supply line 10 and the water pump 11, while the combustion gas is burned. The gas exhaust line 13 is used to supply the water evaporator 6 from the space formed by the first housing 9 and the partition wall (combustion gas exposure prevention means 5). In addition, it is preferable that the temperature of the water supplied to a water evaporator is 5-40 degreeC, on the other hand, it is preferable that the temperature of the combustion gas supplied to a water evaporator is 150-600 degreeC.

  The fuel cell system of the present invention preferably further includes a heat exchanger 14 for heating the oxygen-containing gas supplied to the solid oxide fuel cell 1 by heat exchange with the combustion gas. In this case, since the combustion gas is used for heat exchange with the oxygen-containing gas, the exhaust heat utilization efficiency of the fuel cell system can be improved. The heat exchanger is for heating an oxygen-containing gas supplied to the cathode of the fuel cell. For example, a known heat exchanger can be used. The oxygen-containing gas supply line 15 through which the oxygen-containing gas supplied to the cathode of the physical fuel cell 1 passes and the combustion gas exhaust line 13 through which the combustion gas passes are connected to each other, and the oxygen-containing gas passes through the heat exchanger 14. The oxygen-containing gas is heated by heat exchange between the gas and the combustion gas. The oxygen-containing gas is introduced into the oxygen-containing gas supply line 15 using a blower such as an air blower 16, and the combustion gas from which heat has been recovered is processed as exhaust gas. Here, as the oxygen-containing gas, pure oxygen gas can be used, but air is preferable from the viewpoint of cost and the like. In addition, the temperature of the oxygen-containing gas supplied to the heat exchanger is usually atmospheric temperature, while the temperature of the combustion gas supplied to the heat exchanger is usually 400 to 750 ° C. In addition, as FIG. 1 shows, before discharging | emitting the combustion gas which passed the heat exchanger 14 as exhaust gas, it can supply to the water evaporator 6, and can be utilized for generation | occurrence | production of water vapor | steam.

  In addition, the fuel cell system of the present invention preferably further includes a bypass passage 17 for avoiding a part of the oxygen-containing gas supplied to the solid oxide fuel cell 1 from the heating by the heat exchanger 14. . By preparing the oxygen-containing gas that has not been heated by the heat exchanger, the oxygen-containing gas can be cooled when the temperature of the oxygen-containing gas supplied to the cathode rises excessively. Here, in order to separate a part of the oxygen-containing gas supplied to the cathode of the fuel cell, a bypass channel 17 branched from the oxygen-containing gas supply line 15 is installed before heat exchange with the combustion gas. That's fine. The temperature of the oxygen-containing gas passing through the oxygen-containing gas supply line 15 can be lowered by connecting the bypass flow path 17 to the oxygen-containing gas supply line 15 after heat exchange with the combustion gas. When the temperature of the oxygen-containing gas supplied to the cathode is sufficiently secured, there is no need to introduce a cooling oxygen-containing gas into the oxygen-containing gas supply line. Or the like to block the flow path from the oxygen-containing gas supply line 15 to the bypass flow path 17 or the flow path from the bypass flow path 17 to the oxygen-containing gas supply line 15 to stop the flow of the oxygen-containing gas for cooling. That's fine.

The fuel cell system of the present invention preferably further includes a desulfurizer 18 that desulfurizes the raw fuel to produce a desulfurized raw fuel before producing the reformed gas. The desulfurizer 18 removes sulfur contained in the raw fuel. For example, a desulfurizer body filled with an adsorbent desulfurization agent, a heat exchanger or a heater for heating the desulfurizer body, and the like. Heating means. Here, as the adsorptive desulfurizing agent, an adsorptive desulfurizing agent conventionally used for desulfurization can be used, and for example, a nickel-based desulfurizing agent, an alumina-based desulfurizing agent, or the like is preferably used. In addition, as desulfurization conditions, for example, liquid raw fuel supply amount (LHSV): 0.1 to 5.0 hr ⁻¹ , reaction pressure: 0.1 MPa to less than 1.0 MPa, reaction temperature: 100 ° C. to 300 ° C. Preferably there is. In the desulfurizer 18, the raw fuel is heated in the presence of the adsorbing desulfurizing agent, so that the sulfur content in the raw fuel is adsorbed by the adsorbing desulfurizing agent to generate desulfurized raw fuel. In the illustrated fuel cell system, the raw fuel is supplied from the raw fuel tank 21 to the desulfurizer 18 using the raw fuel supply line 19 and the raw fuel pump 20.

  Furthermore, in the fuel cell system of the present invention, it is preferable to heat the desulfurizer 18 using a part of the oxygen-containing gas heated by the heat exchanger 14. By using a part of the oxygen-containing gas heated by the heat exchanger 14 as a heat source of the desulfurizer 18, the heat utilization efficiency of the fuel cell system can be improved. In addition, the fuel cell off-gas is not directly supplied to the desulfurizer, but a part of the oxygen-containing gas supplied to the cathode of the fuel cell is supplied to the desulfurizer. Even if the temperature or amount of off-gas changes, it is possible to stably secure a heat source for desulfurization. In the fuel cell system of the illustrated example, a desulfurizer heating gas supply line 22 branched from the oxygen-containing gas supply line 15 is installed after heat exchange with the combustion gas.

  The fuel cell system of the present invention usually includes a mixing device 23 that mixes raw fuel (or desulfurized raw fuel) and steam, and the raw fuel and steam obtained by mixing the raw fuel and steam in the mixing device 23. A steam mixed gas is supplied to the reformer 2 to generate a reformed gas. In the fuel cell system of the illustrated example, the mixing device 23 mixes raw fuel and water vapor produced by the water evaporator 6, and for example, a known mixer or the like can be used. Specifically, the mixing device 23 includes, for example, a desulfurization raw fuel supply line 24 that supplies desulfurization raw fuel from the desulfurizer 18 to the mixing device 23, and a water vapor supply line that supplies water vapor from the water evaporator 6 to the mixing device 23. 25 are connected. In addition, it is preferable that the temperature of the water vapor | steam supplied to a mixing apparatus is 300-600 degreeC, On the other hand, it is preferable that the temperature of the desulfurization raw fuel supplied to a mixing apparatus is 10-200 degreeC. In the illustrated fuel cell system, the raw fuel / steam mixed gas is supplied from the mixing device 23 to the reformer 2 using the raw fuel / steam mixed gas supply line 26, and is produced by the reformer 2. The reformed gas is supplied from the reformer 2 to the anode of the solid oxide fuel cell 1 using the reformed gas supply line 27.

  Next, a reformer suitable for the fuel cell system of the present invention will be described in detail with reference to FIG. FIG. 2 is a schematic view showing an example of a reformer used in the fuel cell system of the present invention. The reformer shown in FIG. 2 has a reaction tube 101 at least partially filled with a reforming catalyst, and heat transfer installed on the side of the reaction tube 101 as means for heating the reaction tube 101. And a combustion device comprising an anode off-gas supply means 103 and a cathode off-gas supply means as means for supplying combustion gas to the heat transfer member 102, the combustion device being connected to at least one of the reaction tubes It is characterized by being installed on the bottom side. The bottom surface of the reaction tube refers to surfaces (upper surface and lower surface) located at both ends (both ends) in the longitudinal direction of the reaction tube, and the side surface of the reaction tube refers to a surface other than the bottom surface of the reaction tube. Further, installing on the bottom surface side of the reaction tube means installing on the upper surface of the reaction tube or below the lower surface of the reaction tube, and installing on the side surface of the reaction tube means at least a part of the side surface of the reaction tube. It means to install so as to face.

  In the reforming apparatus of the illustrated example, the reaction tube 101 constitutes a reformer of the fuel cell system of the present invention, and at least a part thereof is filled with the reforming catalyst. A reformed gas containing hydrogen as a main component can be generated by a reforming reaction by contacting a mixture with water vapor. In the above reformer, the number of reaction tubes is arbitrary. For example, the reformer shown in FIG. 2 includes five reaction tubes 101. Further, when the reformer includes a plurality of reaction tubes, the reaction tubes 101 are arranged in parallel as shown in FIG. 2 in order to achieve uniform heat conduction and / or heat radiation from the heat transfer member. It is preferable to arrange.

  In the reformer of the illustrated example, the combustion device constitutes the second combustion means of the fuel cell system of the present invention, and here, the anode off-gas supply means 103 of the combustion device is provided with a gas discharge hole or slit. Are preferred.

  In the reformer of the illustrated example, the heat transfer member 102 is installed on the side surface side of the reaction tube 101 as a means for heating the reaction tube 101, and is heated by a combustion gas supplied by a combustion device described later. As a result, heat conduction and heat radiation to the reaction tube 101 occur, and heat necessary for the reforming reaction in the reaction tube 101 can be supplied. In the above reformer, the number of heat transfer members is arbitrary. For example, when a plurality of reaction tubes 101 are arranged in parallel as shown in FIG. A plurality of heat transfer members 102 are installed so that the plurality of reaction tubes 101 are sandwiched between the heat members 102 (two heat transfer members 102 in FIG. 2). By sandwiching the reaction tube 101 between the heat transfer members 102 in this way, uniform heat conduction and heat radiation to the reaction tube 101 are possible, and the reforming catalyst in the reaction tube 101 can be uniformly heated. . In addition, it is preferable that the temperature of the member for heat transfer is adjusted to the range of 650-1000 degreeC.

  In the reformer, the combustion gas supplied by the combustion device flows while contacting the heat transfer member to heat the heat transfer member, so that the contact efficiency of the combustion gas is improved and the pressure is increased. It is preferable to use the plate fin type heat transfer member 102 because it has a flow path along the flow direction of the combustion gas with little loss and has a rectifying effect. Examples of the shape of the plate fin include a flat plate shape, a wave shape, and an offset type. Furthermore, in the above reformer, in order to reduce the pressure loss of the combustion gas and efficiently supply the combustion gas to the heat transfer member, in other words, the heat transfer member efficiently recovers the combustion gas. As shown in FIG. 2, the heat transfer member 102 preferably has a laminated structure. In addition, as a material of the said member for heat transfer, stainless steel, a nickel alloy, and another heat-resistant metal can be used, for example.

  In the above reformer, it is preferable that the heat transfer member is installed so as to be located inside one end portion or both end portions of the reaction tube. In this way, by arranging the heat transfer member so as to be located inside one end or both ends of the reaction tube, it is possible to prevent an excessive increase in temperature at one end or both ends of the reaction tube. Can be avoided. The temperature range of the reforming catalyst filled in the reaction tube of the reforming apparatus is determined, and such arrangement of the heat transfer member is suitable. Further, in the above reformer, from the viewpoint of efficiently flowing the combustion gas to the heat transfer member, the combustion device is preferably installed above the heat transfer member. Therefore, in FIG. It is installed below the upper end of the reaction tube 101. In addition, the reaction tube is usually connected to a raw fuel / steam mixed gas supply line, a reformed gas supply line, and the like. From the viewpoint of avoiding an excessive increase in temperature in these flow paths, the heat transfer member is reacted. It is preferable to arrange the tube so that it is located inside one or both ends of the tube. In addition, in a preferred embodiment of the reformer, as will be described later, the raw fuel / steam mixed gas supply line and the reformed gas supply line are connected to a reaction tube end on the side where the combustion device is installed. Since it is installed at the opposite end, the heat transfer member 102 is installed below the upper end of the reaction tube 101 and above the lower end of the reaction tube 101 as shown in FIG. Therefore, in the reformer, it is particularly preferable that the heat transfer member is installed so as to be located inside both ends of the reaction tube. As shown in FIG. 3, when the length of the reaction tube is L, the heat transfer member may be installed at a position where the linear distance from the end P of the reaction tube is (1/20) L or more. preferable. Here, FIG. 3 is a schematic view of the reformer shown in FIG. 2 as viewed from the left side.

  Further, in the above reformer, in order to uniformly heat the plurality of reaction tubes, it is preferable to install a heat transfer member in parallel with the reaction tubes. Also, as shown in FIG. When 101 is arrange | positioned in parallel, it is preferable to install this heat transfer member 102 in the direction parallel to the parallel direction of the reaction tube 101.

  Furthermore, it is preferable that the reformer includes a combustion gas collecting unit installed so as to be located on the opposite side of the combustion device via the heat transfer member. Here, the combustion gas collecting part means that the cross section perpendicular to the flow direction of the combustion gas supplied to the heat transfer member is larger than the cross-sectional area of the flow path of the combustion gas supplied to the heat transfer member. It is a part to gather. By installing the combustion gas collecting part on the side opposite to the combustion device, the combustion gas can be discharged stably and smoothly from the reformer. That is, when the combustion gas discharge passage is provided as the combustion gas discharge means, the disturbance of the gas flow of the combustion gas passing through the combustion gas discharge passage can be reduced. Further, when the combustion gas discharge means is provided, the flow rate of the combustion gas flowing while contacting the heat transfer member may vary depending on the distance from the combustion gas discharge means. If installed, the flow rate of the combustion gas can be kept constant. In the reformer shown in FIG. 2, the space located below the heat transfer member 102 corresponds to the combustion gas collecting portion. FIG. 3 is a schematic view of the reformer shown in FIG. 2 as viewed from the left side, and shows the combustion gas collecting part 109.

  In the reformer shown in FIG. 2, the combustion apparatus includes an anode offgas supply means 103 and a cathode offgas supply means as means for supplying combustion gas to the heat transfer member 102. Here, according to the combustion apparatus, by using the cathode offgas supplied by the cathode offgas supply means as the combustion-supporting gas, the combustion gas of the anode offgas supplied by the anode offgas supply means can be generated. Further, although not particularly limited, as shown in FIG. 2, the anode off gas supply means 103 is disposed above the heat transfer member 102 so that the combustion gas can be easily supplied to the heat transfer member 102. can do. In the above reformer, the combustion tube is not brought into direct contact with the reaction tube, but the reaction tube is heated stably and uniformly because the reaction tube is heated using heat conduction and heat radiation from the heat transfer member. It is possible to heat and the reaction tube can be heated effectively.

  As the anode off gas supply means 103 of the combustion apparatus, it is preferable to use an anode off gas supply channel connected to the anode of the fuel cell. The anode off-gas supply channel is preferably tubular in order to reduce gas flow turbulence, and a plurality of gas discharge ports for discharging the anode off-gas are provided on the side of the tube. preferable. By providing a plurality of gas discharge ports, combustion occurs in the vicinity of the exhaust ports, and this combustion gas can be evenly supplied to the heat transfer member. When the anode off gas supply channel has a plurality of gas discharge ports on the side surface of the pipe, the end E on the side opposite to the connecting portion to the fuel cell is more evenly distributed to the heat transfer member. From the viewpoint of supply, it is preferably closed. Furthermore, in order to more evenly distribute the heat generated by at least one of conduction and radiation to the plurality of reaction tubes, it is preferable that the flow direction of the combustion gas flowing through the heat transfer member and the longitudinal direction of the reaction tube are parallel. In addition, as shown in FIG. 2, when a plurality of reaction tubes 101 are arranged in parallel, it is preferable to extend the anode off gas supply means 103 in a direction parallel to the parallel direction of the reaction tubes 101.

  The cathode off-gas supply means of the combustion apparatus is means for supplying cathode off-gas as a combustion-supporting gas to the anode off-gas. For example, as with the anode offgas supply means 103, a cathode offgas supply channel may be provided as the cathode offgas supply means to supply the cathode offgas. However, as shown in FIG. A portion (that is, a gas discharge port of the anode off-gas supply channel), a part of a combustion gas supply means 105 described later (that is, a gas discharge port of the combustion gas supply channel), a heat transfer member 102, and the reaction tube 101. As described above, a housing (hereinafter also referred to as a second housing) 104 may be provided to supply oxygen-containing gas into the housing 104. If the cathode offgas is supplied into the housing 104, the anode offgas is mixed with the anode offgas at the same time as being discharged from the anode offgas supply means 103, preferably at the same time as being discharged from the plurality of gas discharge ports. Combustion gas can be generated. In the reformer shown in FIG. 2, the upper portion of the second housing 104 is opened, and the cathode offgas discharged from the cathode of the fuel cell is introduced into the second housing 104. Further, since the cathode off gas is substantially continuously introduced into the second housing 104, the combustion gas does not flow backward from the upper part of the second housing 104.

  As shown in FIG. 3, when the enclosure is formed by the second housing 104, the above-described combustion gas collecting portion 109 can be easily formed. When the enclosure is formed by the second housing 104, as shown in FIG. 2, it is necessary to install the combustion gas discharge means 106 on the side opposite to the combustion device via the heat transfer member 102. As the discharge means, for example, a hole is formed in a part of the second housing, and a means for discharging the combustion gas from the hole to the outside of the second housing, or a combustion gas discharge passage connected to the second housing is provided. Can be used. As shown in FIG. 2, the combustion gas discharge means 106 is installed at a position opposite to the combustion device via the heat transfer member 102, and in addition, the second housing of the anode off gas supply means 103 It is preferable that the insertion port 107 and the combustion gas discharge means 106 be installed so as to face the diagonal direction of the heat transfer member 102. In this way, the flow of the combustion gas to the heat transfer member 102 can be made uniform.

  The reformer shown in FIG. 2 includes combustion gas supply means 105 for heating at least one fuel selected from the group consisting of hydrocarbons and aliphatic alcohols to heat the reactor 101. The combustion gas supply means 105 constitutes the first combustion means of the fuel cell system of the present invention. Examples of the combustion gas supply means include a liquid fuel burner and a gas burner, and the combustion gas generated by the burner can be used. A suitable shape, arrangement position, and the like of the combustion gas supply means are the same as those in the above-described anode off-gas supply flow path. The combustion gas supply means supplies the combustion gas to the heat transfer member after previously burning the fuel.

  In the above reformer, since no heat transfer member is disposed above or below the reaction tube, the anode off-gas supply means and / or the combustion gas supply means of the combustion device are located near the end of the reaction tube (the vicinity of the upper end or It may be installed near the lower end. In this case, it is preferable to install a heat insulating member between the anode off-gas supply means and / or the combustion gas supply means and the reaction tube. By installing a heat insulating member between the anode off-gas supply means and / or the combustion gas supply means and the reaction tube, it is possible to avoid the reaction tube from directly receiving the radiant heat from the anode off-gas supply means and / or the combustion gas supply means. Can do. The shape of the heat insulating member is preferably a shape like a lid that covers the end of the reaction tube, and a plurality of reaction tubes 101 are arranged in parallel as shown in FIG. In the case where the anode off-gas supply means 103 and the combustion gas supply means 105 are installed above the lid, in order to prevent the combustion gas from flowing into the gaps in the arrangement of the reaction tubes, a lid that covers the ends of all the reaction tubes It is preferable that the shape is as follows. Further, the material of the heat insulating member is not particularly limited, but a silica alumina board, ceramic fiber or the like can be used. As used herein, the vicinity of the end of the reaction tube refers to the reaction tube from the end P of the reaction tube to the anode off-gas supply means or the combustion gas supply means, as shown in FIG. Means the region where the shortest distance is within (1/2) L.

  The reformer includes a partition wall 108 between the reaction tube 101 and the heat transfer member 102 as shown in FIG. 3 in order to more reliably avoid contact of the combustion gas with the reaction tube. preferable. Moreover, since it is necessary to transmit the heat from the heat transfer member to the reaction tube by at least one of conduction and radiation, stainless steel, nickel alloy, or the like can be used as the material of the partition wall.

  The reformer is suitable as an oxidation autothermal reformer that can utilize the heat of oxidation in the apparatus for the reforming reaction. The oxidation autothermal reformer is at least partially filled with a reforming catalyst, and a mixture of raw fuel and water vapor is brought into contact with the reforming catalyst to form hydrogen as a main component. A reforming layer for generating a reformed gas, and an oxidation exothermic layer that is at least partially filled with an oxidation catalyst and oxidizes part of the raw fuel or reformed gas to generate heat. Quality equipment. Here, the reaction tube of the reformer preferably has a double tube structure in which one end is closed and the inner tube and the outer tube communicate with each other at the closed end. If the reaction tube has a double-pipe structure, not only can the oxidation autothermal reforming apparatus be reduced in size, but the apparatus can be manufactured at a low cost, and the oxidizing gas supply means with a simple structure can be used for oxidation. Gas can be uniformly supplied to the oxidation heat generating layer. Further, the reformer is provided with a raw material for supplying a mixture of raw fuel and water vapor to the gap between the outer tube and the inner tube of the reaction tube at the other end opposite to the one end of the reaction tube. It is preferable to provide a reformed gas supply line for discharging the reformed gas from the fuel / steam mixed gas supply line and the inner pipe and supplying the reformed gas to the fuel cell. The inner tube and the outer tube of the reaction tube communicate with each other at a closed end, and the reformed gas generated by the reforming reaction in the reforming layer is discharged through the inner tube. When the raw fuel / steam mixed gas supply line and the reformed gas supply line are provided at the end (the other end) opposite to the closed end, introduction of the raw fuel into the reformed layer and the reformed gas This is because it is not necessary to provide complicated piping for discharging from the inner pipe, and the apparatus can be easily manufactured.

  FIG. 4 is a partial cross-sectional view of the reformer shown in FIG. 2, and the cross section of the reaction tube 101 will be described in detail. The reaction tube 101 shown in FIG. 4 has a double tube structure including an outer tube 111 whose upper end is closed and an inner tube 112, and an inverted convex shape in which the inner tube 112 protrudes downward. I am doing. Further, inside the inner tube 112 of the reaction tube 101, an oxidizing gas supply pipe 118 is provided as an oxidizing gas supply means for supplying air or oxygen as an oxidizing gas. A reforming layer 113 made of a reforming catalyst is provided in the gap between the outer pipe 111 and the inner pipe 112. The inner pipe 112 has an oxidation catalyst layer 114 made of an oxidation catalyst, and heat transfer. An oxidation exothermic layer 116 composed of a heat transfer particle layer 115 made of particles is provided. The reforming catalyst, the oxidation catalyst, and the heat transfer particles are supported by a mesh 117 provided below the outer tube 111 and the inner tube 112. The mesh 117 is formed by the reforming catalyst, the oxidation catalyst, and the heat transfer particles. Is not allowed to pass through, but the reforming raw material, steam and reformed gas are allowed to pass through. Further, the double pipe structure including the outer pipe 111 and the inner pipe 112 is formed by welding and fixing two pipes having different diameters to a manifold 120 described in detail later.

  Here, as the oxidation catalyst constituting a part of the oxidation heat generation layer 116, an oxidation catalyst or the like in which Pt, Pd, etc., which hardly deteriorate at high temperatures, are supported on a carrier such as alumina, silica, zirconia, etc. can be used. The addition amount of the catalyst is preferably not less than an amount that allows the oxidizing gas to be completely reacted. Furthermore, as the heat transfer particles, particles capable of transferring heat generated by an oxidation reaction using an oxidation catalyst, such as SiC particles, can be used. In the oxidation exothermic layer 116 of the reformer shown in FIG. 4, the oxidation exothermic layer 116 including the oxidation catalyst layer 114 and the heat transfer particle layer 115 is formed by filling the heat transfer particles and then the oxidation catalyst. The oxidation heat generating layer that can be used in the reformer is not limited to this. Specifically, the oxidation exothermic layer may be formed by filling the inner tube with a mixture of (1) the above-described oxidation catalyst and a reforming catalyst supporting Ni, Rh or the like, and (2) the oxidation catalyst. And a mixture of heat transfer particles may be filled in the inner tube, or (3) a mixture of the oxidation catalyst, the reforming catalyst, and the heat transfer particles may be filled in the inner tube. good.

  The oxidizing gas supply pipe 118 is not particularly limited as long as it can supply the oxidizing gas used for the oxidation reaction to the oxidation catalyst of the oxidation heat generation layer 116, but the reforming catalyst of the reforming layer 113 is deteriorated by the oxidizing gas. In order to avoid this, it is preferable to provide an outlet for oxidizing gas on the rear side of the modified layer 113. In the reformer shown in FIG. 4, the oxidizing gas supply pipe 118 has a tip positioned in the oxidation catalyst layer 114, and an oxidizing gas ejection port is provided at the tip.

  A manifold 120 provided at a lower portion of the reaction tube 101 is a raw fuel / steam mixed gas supply line for supplying a mixture of raw fuel and steam to a gap between the outer tube 111 and the inner tube 112 of the reaction tube 101. 121, a reformed gas supply line 122 for discharging the reformed gas from the inner tube 112 of the reaction tube 101 and supplying the reformed gas to the fuel cell, and an oxidizing heat generating layer via the oxidizing gas supply tube 118 And an oxidizing gas supply line 123 for supplying an oxidizing gas to 116. As shown in FIG. 2, the raw fuel / steam mixed gas supply line 121, the reformed gas supply line 122, and the oxidizing gas supply line 123 of the manifold 120 have a flow path common to the five reaction tubes 101. It has become. The raw fuel / steam mixed gas supply line 121 communicates with a gap between the outer tube 111 and the inner tube 112 of the reaction tube 101, and the reformed gas supply line 122 communicates with the inner tube 112. The oxidizing gas supply line 123 communicates with the oxidizing gas supply pipe 118.

  Further, in the manifold 120, an inlet portion through which the mixture is supplied into the raw fuel / steam mixed gas supply line 121 and an outlet portion through which the reformed gas is discharged from the reformed gas supply line 122 sandwich the reaction tube 101. And located on the opposite side of the manifold 120. In this way, the distribution of the mixture to each reaction tube 1 can be made uniform. Further, in the manifold 120, the inlet portion where the oxidizing gas is supplied into the oxidizing gas supply line 123 is also opposite to the outlet portion of the reformed gas supply line 122, that is, the raw fuel / steam mixed gas supply line 121. Located on the same side as the entrance. This is preferable from the viewpoint that the distribution of the oxidizing gas to each reaction tube 101 can be made uniform.

  In addition, the shape of the manifold and the arrangement of the reaction tubes on the manifold can be any shape. Specifically, the planar shape of the manifold (the shape seen from the reaction tube side) can be an appropriate shape depending on the arrangement of the reaction tubes, for example, square, rectangle, triangle, circle, L-shape, V It can be a letter shape, a U shape, a zigzag shape, or the like. The reaction tube on the manifold is preferably perpendicular to the plane of the manifold.

  In the reforming apparatus shown in FIG. 4, the mixture of raw fuel and steam supplied via the raw fuel / steam mixed gas supply line 121 is reformed in the reforming layer 113 at a temperature of 400 to 800 ° C., for example. A reformed gas containing hydrogen as a main component is produced. Specifically, as shown in FIG. 4, the mixture supplied to the reaction tube 101 is reformed through the reforming layer 113 by upflow, and then folded at the closed end of the upper portion of the reaction tube 101 to return to the inner tube. 112, passes through the oxidation heat generation layer 116 in a down flow, and is discharged from the reformed gas supply line 122. Here, the amount of heat necessary for the reforming reaction in the reforming layer 113 is supplied by conduction and radiation from the heat transfer member 102 described above, but the amount of heat at the time of starting the fuel cell or at the time of a sudden load change or the like. When the amount is insufficient, an oxidizing gas may be supplied to the oxidation heat generating layer 116, and heat obtained by oxidizing a part of the reformed gas or raw fuel generated by reforming the mixture may be used. The reformed gas generated by the reformer is supplied to the fuel cell and used as power generation fuel.

  Next, the fuel cell system using the reformer shown in FIG. 2 will be described in detail with reference to FIG. FIG. 5 is a partial schematic view showing another example of the fuel cell system of the present invention. A fuel cell system shown in FIG. 5 includes a fuel cell stack 201 in which a plurality of cells of a solid oxide fuel cell are combined, a reformer shown in FIG. 2, and a first that surrounds the fuel cell stack 201 and the reformer. And a housing 202. In this case, the cathode off gas discharged from the fuel cell stack 201 is introduced into the second housing 104. Further, the second housing 104 functions as a combustion gas exposure prevention means of the fuel cell system of the present invention.

  Further, the method for starting the fuel cell system of the present invention generates a combustion gas by burning at least one fuel selected from the group consisting of hydrocarbons and aliphatic alcohols, and uses the combustion gas to form a reformer. A step of preventing the solid oxide fuel cell from being exposed to the combustion gas, and a water evaporator located downstream of the reformer in the flow direction of the combustion gas. The process of heating with combustion gas to generate water vapor, and the temperature of the water evaporator reaches a temperature higher than the temperature at which water vapor can be generated, and the temperature of the reformer performs the reforming reaction of the raw fuel After the temperature reaches a temperature higher than possible, the steam and raw fuel are supplied to the reformer to start a reforming reaction to generate a reformed gas, and the solid oxide fuel cell The temperature of the solid oxide fuel cell Before reaching the temperature at which the node is oxidized, and characterized by including a step for supplying the reformed gas to the anode of the solid oxide fuel cell can be achieved by the above-described fuel cell system.

  In the start-up method of the fuel cell system of the present invention, at least one fuel selected from the group consisting of hydrocarbons and aliphatic alcohols is combusted to generate combustion gas, and the reformer is heated using the combustion gas. In addition, the solid oxide fuel cell is prevented from being exposed to the combustion gas. As a result, the reformer can be preferentially heated, and the reformer exceeds the temperature at which the steam reforming reaction can be started before the solid oxide fuel cell is heated above the temperature at which the anode is oxidized. Can be heated. In addition, the oxidation of the anode of the fuel cell usually occurs at 400 ° C. or higher, while the steam reforming reaction can be normally performed at 600 ° C. or higher.

  In the start-up method of the fuel cell system of the present invention, it is necessary to heat the water evaporator located downstream of the reformer in the flow direction of the combustion gas with the combustion gas to generate water vapor. As a result, it is possible to immediately supply water vapor to the sufficiently heated reformer while improving the exhaust heat utilization efficiency of the fuel cell system, so that the fuel cell system can be started up effectively in a short time.

  In the fuel cell system start-up method of the present invention, the temperature of the water evaporator reaches or exceeds the temperature at which water vapor can be generated, and the reformer temperature can perform the reforming reaction of the raw fuel. After reaching a certain temperature or higher, it is necessary to supply steam and raw fuel to the reformer to start the reforming reaction and generate reformed gas. As a result, the reforming reaction in the reformer can be reliably performed, and the reformed gas can be reliably supplied to the solid oxide fuel cell.

  In the start-up method of the fuel cell system of the present invention, the temperature of the solid oxide fuel cell is changed to the anode of the solid oxide fuel cell before reaching the temperature at which the anode of the solid oxide fuel cell is oxidized. It is necessary to supply quality gas. Thereby, the oxidation of the anode of the solid oxide fuel cell can be prevented.

  The fuel cell system start-up method of the present invention is further supplied to the solid oxide fuel cell by heat exchange with the combustion gas in the heat exchanger located downstream of the reformer in the flow direction of the combustion gas. It is preferable to include a step of heating the oxygen-containing gas. As a result, it is possible to supply the heated oxygen-containing gas to the solid oxide fuel cell while improving the exhaust heat utilization efficiency of the fuel cell system, so that the fuel cell system can be started up effectively in a short time. Become. Here, the fuel cell system start-up method of the present invention uses a part of the heated oxygen-containing gas to heat the desulfurizer to desulfurize the raw fuel supplied to the reformer and use it as a desulfurized raw fuel. More preferably, the method includes the step of: In this case, it is possible to stably secure a heat source for desulfurization while further improving the exhaust heat utilization efficiency of the fuel cell system.

  The fuel cell system startup method of the present invention further provides an oxygen-containing gas that does not exchange heat with the combustion gas among the oxygen-containing gas supplied to the solid oxide fuel cell, and the oxygen-containing gas is solidified. It is preferable to include a step of supplying the oxide fuel cell. Thereby, it can prevent that the temperature of this solid oxide fuel cell rises too much by supplying the oxygen containing gas heated by the said heat exchange to a solid oxide fuel cell. The oxygen-containing gas that is not subjected to heat exchange may be directly supplied to the solid oxide fuel cell, or mixed with the oxygen-containing gas heated using the bypass channel 17 as shown in FIG. Then, it may be supplied to the solid oxide fuel cell.

  The start-up method of the fuel cell system of the present invention preferably further includes a step of introducing an oxidizing gas containing oxygen into the reformer to perform a partial oxidation reaction. Thereby, the partial oxidation reaction is performed in the reformer, and the temperature of the reformer can be raised by the reaction heat of the partial oxidation reaction.

DESCRIPTION OF SYMBOLS 1 Solid oxide fuel cell 2 Reformer 3 First combustion means 4 Second combustion means 5 Combustion gas exposure prevention means 6 Water evaporator 7 Anode off gas supply means 8 Cathode off gas supply means 9 Housing 10 Water supply line 11 Water pump 12 Water tank 13 Combustion gas exhaust line 14 Heat exchanger 15 Oxygen-containing gas supply line 16 Air blower 17 Bypass flow path 18 Desulfurizer 19 Raw fuel supply line 20 Raw fuel pump 21 Raw fuel tank 22 Gas supply line for desulfurizer heating 23 Mixing device 24 Desulfurization raw fuel supply line 25 Steam supply line 26 Raw fuel / steam mixed gas supply line 27 Reformed gas supply line 101 Reaction tube 102 Heat transfer member 103 Anode off-gas supply means 104 Housing 105 Combustion gas supply means 106 Combustion gas Discharge means 107 Anode Insertion port of the off-gas supply means into the second housing 108 Partition 109 Combustion gas collecting part 111 Outer tube 112 Inner tube 113 Modified layer 114 Oxidation catalyst layer 115 Heat transfer particle layer 116 Oxidation heat generation layer 117 Mesh 118 Oxidizing gas supply tube 120 Manifold 121 Raw fuel / steam mixed gas supply line 122 Reformed gas supply line 123 Oxidizing gas supply line 201 Fuel cell stack 202 First housing

Claims (9)

A solid oxide fuel cell;
A reformer for reforming raw fuel to produce reformed gas;
First combustion means for burning at least one fuel selected from the group consisting of hydrocarbons and aliphatic alcohols to heat the reformer;
Second combustion means for combusting anode off-gas from the solid oxide fuel cell to heat the reformer;
Combustion gas exposure prevention means for preventing the solid oxide fuel cell from being exposed to combustion gas generated by at least one of the first combustion means and the second combustion means;
A water evaporator located downstream of the reformer in the flow direction of the combustion gas, and a water evaporator which generates steam by heat exchange with the combustion gas,
The fuel cell system wherein the combustion gas exposure prevention means, according to the first combustion unit, the second combustion means and said housing der Rukoto surrounding the reformer. The fuel cell system according to claim 1, further comprising a heat transfer member installed on a side surface of the reformer.   The solid oxide fuel cell is heated by at least one of heat conduction and heat radiation from at least one means selected from the group consisting of the first combustion means, the second combustion means, and the combustion gas exposure prevention means. The fuel cell system according to claim 1, wherein: Furthermore, a heat exchanger for heating the oxygen-containing gas supplied to the solid oxide fuel cell by heat exchange with the combustion gas, and desulfurizing the raw fuel before producing the reformed gas, A desulfurizer as a fuel ,
The fuel cell system of claim 1 wherein the desulfurizer is characterized by Rukoto is heated using a portion of the oxygen-containing gas heated by said heat exchanger. 5. The fuel cell system according to claim 4 , further comprising a bypass flow path for avoiding a part of the oxygen-containing gas supplied to the solid oxide fuel cell from the heating by the heat exchanger. . A method for starting a fuel cell system according to any one of claims 1 to 5,
Combusting at least one fuel selected from the group consisting of hydrocarbons and aliphatic alcohols to generate a combustion gas, and heating the reformer using the combustion gas, the solid oxidation of the combustion gas A step of preventing the physical fuel cell from being exposed;
Heating a water evaporator located downstream of the reformer in the flow direction of the combustion gas with the combustion gas to generate water vapor;
After the temperature of the water evaporator reaches a temperature at which steam can be generated or higher, and the temperature of the reformer reaches a temperature at which the reforming reaction of raw fuel can be performed, the reforming is performed. Supplying the steam and raw fuel to a mass device to start a reforming reaction and generating a reformed gas;
Supplying the reformed gas to the anode of the solid oxide fuel cell before the temperature of the solid oxide fuel cell reaches a temperature at which the anode of the solid oxide fuel cell oxidizes. And a starting method of the fuel cell system. Heating the oxygen-containing gas supplied to the solid oxide fuel cell by heat exchange with the combustion gas in a heat exchanger located downstream of the reformer in the flow direction of the combustion gas; ,
The method further comprises: heating a desulfurizer that uses a part of the heated oxygen-containing gas to desulfurize the raw fuel supplied to the reformer to obtain a desulfurized raw fuel. 6. A starting method of the fuel cell system according to 6.   Further, a step of preparing an oxygen-containing gas that does not exchange heat with the combustion gas among the oxygen-containing gas supplied to the solid oxide fuel cell, and supplying the oxygen-containing gas to the solid oxide fuel cell The start method of the fuel cell system according to claim 7, comprising:   The method of starting a fuel cell system according to claim 6, further comprising a step of introducing an oxidizing gas containing oxygen into the reformer to perform a partial oxidation reaction.

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