JP4805736B2 - Indirect internal reforming type solid oxide fuel cell - Google Patents

Description

The present invention relates to an indirect internal reforming solid oxide fuel cell having a reformer in the vicinity of the fuel cell.

  Solid oxide fuel cells (hereinafter referred to as SOFC in some cases) are usually generated by reforming hydrocarbon fuels (reforming raw materials) such as kerosene and city gas in a reformer. Hydrogen-containing gas (reformed gas) is supplied. In the SOFC, the reformed gas and air are reacted electrochemically to generate electricity.

  The SOFC is usually operated at a high temperature of about 550 ° C to 1000 ° C.

  Various reactions such as steam reforming and partial oxidation reforming are used for the reforming, but steam reforming is a reaction accompanied by a very large endotherm, and the reaction temperature is comparatively as about 550 ° C. to 750 ° C. Requires a high and hot heat source. Therefore, an indirect internal reforming SOFC is known in which a reformer is installed in the vicinity of the SOFC (a position that receives heat radiation from the SOFC) and the reformer is heated by radiant heat from the SOFC. Further, a combustible component-containing gas (anode off gas) discharged from the anode of the SOFC is combusted, and the reformer is heated using this combustion heat as a heat source.

An indirect internal reforming SOFC is described in Patent Document 1.
JP 2002-358997 A

  As described above, in the indirect internal reforming SOFC, the reformer is heated using SOFC as a heat source. However, since the heat of the SOFC cannot be expected at the time of startup, it is required to raise the temperature of the catalyst to a temperature at which the reforming catalyst exhibits activity by means other than the SOFC.

  It is conceivable to heat the reforming catalyst by supplying a gas heated by an electric heater to the reforming catalyst. However, this requires a great amount of electric power before heating the reforming catalyst to a temperature at which reforming can be performed, and it takes a long time to raise the temperature.

  Indirect internal reforming SOFCs can provide the heat required for reforming by exhaust heat of SOFC during normal operation (at rated operation or partial load operation). May be insufficient, the reforming may be insufficient, and the SOFC downstream of the reformer may be adversely affected. In particular, when a higher order hydrocarbon such as kerosene is used, if the higher order hydrocarbon leaks from the reformer, the performance of the SOFC may deteriorate due to carbon deposition.

  An object of the present invention is to provide an indirect internal reforming SOFC that can shorten the startup time and can be operated more stably during normal operation.

Another object of the present invention is to provide a method capable of suitably starting such an indirect internal reforming SOFC.

According to the present invention,
A reforming reaction tube for reforming a fuel containing carbon and hydrogen in the molecule;
A tubular burner with a plurality of flame holes in the tube wall;
A solid oxide fuel cell that generates power using the reformed gas obtained from the reforming reaction tube;
The tubular burner is disposed at a position where radiant heat and / or combustion gas from a flame blown out from the flame hole hits the reforming reaction tube;
The reforming reaction tube is disposed at a position to receive heat radiation from the solid oxide fuel cell.
An indirect internal reforming solid oxide fuel cell is provided.

The reforming reaction tube preferably contains a catalyst having a steam reforming ability for steam reforming a fuel containing carbon and hydrogen in the molecule .

In the indirect internal reforming solid oxide fuel cell, the reforming reaction tube and the tubular burner are both straight tubes,
A plurality of the reforming reaction tubes;
The reforming reaction tube and the tubular burner are preferably arranged in parallel to each other.

According to the present invention,
A method of starting the indirect internal reforming solid oxide fuel cell,
A step of heating the reforming reaction tube by performing combustion in the tubular burner and applying radiant heat and / or combustion gas from a flame blown out of the flame hole to the reforming reaction tube;
When the reforming reaction tube reaches a reformable temperature, fuel containing carbon and hydrogen in the molecule is supplied to the reforming reaction tube to produce reformed gas, and the reformed gas is used as the solid oxide fuel cell. The process of supplying to
Starting the power generation when the solid oxide fuel cell reaches a temperature capable of generating power, and heating the solid oxide fuel cell by heat generated by the power generation; and
A step of stopping combustion of the tubular burner when the reforming reaction tube is heated by the heat from the solid oxide fuel cell and the heat necessary for reforming can be provided
A method for starting an indirect internal reforming solid oxide fuel cell is provided.

  The present invention provides an indirect internal reforming SOFC that can shorten the startup time and can be operated more stably during normal operation.

The present invention provides a method capable of suitably starting such an indirect internal reforming SOFC.

The reformer used in the present invention is provided with a reforming reaction tube for reforming a fuel containing carbon and hydrogen in its molecule (referred to as a hydrocarbon-based fuel in this specification ) , and a plurality of flame holes on the tube wall. With a tubular burner.

  A hydrocarbon-based fuel is supplied to the reforming reaction tube. In the reforming reaction tube, the hydrocarbon-based fuel is reformed to obtain a reformed gas containing hydrogen.

  The tubular burner is supplied with combustible material and oxygen-containing gas such as air. Only a combustible material can be supplied to the tubular burner, and combustion can be performed by oxygen existing around the tubular burner. The combustible material burns in the tubular burner, and the flame blows out from the flame hole. The tubular burner is arranged at a position where the reforming reaction tube can be heated by this flame.

  The indirect internal reforming solid oxide fuel cell of the present invention has an SOFC that generates power using the reformed gas in addition to the reforming reaction tube and the tubular burner. The reforming reaction tube is disposed at a position that receives heat radiation from the SOFC. The reforming reaction tube, tubular burner and SOFC can be housed in one container (module container) to form a module.

[Hydrocarbon fuel]
As the hydrocarbon-based fuel, as a reformed gas raw material, a compound known from the field of SOFC, containing carbon and hydrogen (may contain other elements such as oxygen) or a mixture thereof, or a mixture thereof may be used as appropriate. And compounds having carbon and hydrogen in the molecule such as hydrocarbons and alcohols can be used. For example, hydrocarbon fuels such as methane, ethane, propane, butane, natural gas, LPG, city gas, gasoline, naphtha, kerosene, and light oil, alcohols such as methanol and ethanol, ethers such as dimethyl ether, and the like.

  Of these, kerosene is preferable because it is easily available for industrial use and for consumer use, and is easy to handle. Further, since the kerosene is reformed at a relatively high temperature, it takes a relatively long time to start up, and the possibility of carbon deposition is relatively high. For this reason, when kerosene is used for hydrocarbon fuel, the effect of the present invention is remarkable.

[Combustible material (tubular burner fuel)]
In the present invention, the heat of combustion by the tubular burner is used as a heat source for heating the reforming reaction tube at the time of startup or the like. The combustible material burned by the tubular burner can be appropriately selected from combustible materials combustible by the burner. From the viewpoint of ease of handling, it is preferable to use a gas or liquid combustible material.

  It is preferable to use the same type of hydrocarbon fuel as the reforming raw material for the combustibles burned by the tubular burner because only one supply source is required.

[Reforming reaction tube]
The hydrocarbon fuel is reformed inside the reforming reaction tube. The reforming reaction tube can accommodate a catalyst that promotes the reforming reaction.

  In an indirect internal reforming SOFC, steam reforming can provide a reformed gas composition more suitable for power generation by SOFC than partial oxidation reforming. Therefore, it is preferable to perform steam reforming or autothermal reforming (performing both steam reforming and partial oxidation reforming) in the reforming reaction tube. In autothermal reforming, steam reforming is dominant, and therefore the reforming reaction becomes endothermic in overall. Then, heat necessary for the reforming reaction is supplied from the SOFC. The reforming reaction tube is disposed at a position that receives heat radiation from the SOFC.

  Steam is supplied to the reforming reaction tube when steam reforming (including autothermal reforming) is performed, and when partial oxidation reforming (including autothermal reforming) is performed. Is supplied with an oxygen-containing gas such as air.

  When using a liquid hydrocarbon fuel at room temperature and normal pressure (25 ° C., 0.101 MPa) such as kerosene, in order to supply a gaseous hydrocarbon fuel to the reforming reaction tube, upstream of the reforming reaction tube ( A vaporizer for vaporizing the hydrocarbon fuel can be provided in the flow of the hydrocarbon fuel). Further, in order to supply water vapor to the reforming reaction tube, a vaporizer for vaporizing water can be provided upstream of the reforming reaction tube (with respect to the flow of water). As a heat source for vaporization, for example, a gas discharged from SOFC can be used. Also, radiant heat from the SOFC can be used. In this case, a vaporizer is provided inside the indirect internal reforming SOFC (inside the module container). When the temperature of the SOFC is low such as at the time of start-up and the heat of vaporization is insufficient, for example, combustion heat can be generated by an auxiliary burner provided separately, and vaporization can be performed using the heat.

  In addition, the feed to the reforming reaction tube can be preheated, and a preheater for that purpose is provided as needed. As a heat source for preheating, for example, gas discharged from SOFC can be used, and radiant heat from SOFC can also be used. If the SOFC temperature is low, such as during startup, and the desired preheating cannot be performed with these heats, for example, combustion heat can be generated by an auxiliary burner provided separately, and the heat can be used for vaporization. .

  Pressure boosting means such as a compressor, a blower, and a pump for boosting the supply to the reforming reaction tube, such as hydrocarbon-based fuel, oxygen-containing gas such as water vapor and air, are appropriately provided as necessary.

  As the reforming reaction tube, a straight tube can be used, but not limited thereto, and in some cases, a spiral tube or a bellows tube can also be used. The reforming reaction tube may be a single tube (single tube) or may have a double tube structure. The cross section of the reforming reaction tube is not limited to a circle, and accordingly, a rectangular tube or the like can be used as the reforming reaction tube in addition to the circular tube.

  In order to monitor the temperature of the reforming reaction tube, temperature detection means can be provided as appropriate. For example, a thermocouple can be provided in the reforming catalyst layer in which the reforming reaction tube is filled with the reforming catalyst.

[Tubular burner]
As the tubular burner, a known burner capable of burning the combustible material to be used can be appropriately used.

  When using a liquid combustible material such as kerosene at room temperature and normal pressure (25 ° C, 0.101 MPa), it is combustible upstream of the tubular burner (for the flow of combustible material) in order to supply the gaseous combustible material to the tubular burner. A vaporizer can be provided to vaporize the object. As a heat source for vaporization, for example, a gas discharged from SOFC can be used. Further, it is preferable to use radiant heat from the SOFC. In this case, the vaporizer is provided inside the indirect internal reforming SOFC (inside the module container). When the temperature of the SOFC is low such as at the time of start-up and the heat of vaporization is insufficient, for example, combustion heat can be generated by an auxiliary burner provided separately, and vaporization can be performed using the heat.

  An igniter can be provided as appropriate for the ignition of the tubular burner.

  The tubular burner is provided inside the indirect internal reforming SOFC module.

  In order to supply an oxygen-containing gas such as air or a combustible material to the tubular burner, a pressure increasing means such as a compressor, a blower, or a pump for increasing the pressure is appropriately provided as necessary.

  A flame blows out from a flame hole provided in the tube wall of the tubular burner. The flame hole is a through hole provided in the tube wall. The reforming reaction tube is heated by the radiant heat from the flame and the combustion gas.

  As the tubular burner, a straight pipe can be used, but not limited thereto, and in some cases, a spiral pipe or a bellows pipe can also be used. For example, a plurality of flame holes can be provided on the side wall of a straight pipe whose one end is closed. The cross section of the tubular burner is not limited to a circle, and therefore a rectangular tube or the like can be used as appropriate for the tubular burner in addition to the circular tube.

  The tubular burner is arranged at a position where the reforming reaction tube can be heated by the flame blown out from the flame hole.

  It is preferable that the flame hole faces the direction toward the reforming pipe. As a result, radiant heat and combustion gas from the flame can be applied to the reforming reaction tube, and the reforming reaction tube can be efficiently heated.

  A straight tube is used for the reforming reaction tube and the tubular burner, and the reforming reaction tube and the tubular burner are arranged in parallel with each other, so that the reforming reaction tube is uniformly and efficiently heated by the flame blown out from the flame hole. To preferred.

  In order to efficiently perform heat transfer from the SOFC to the reforming reaction tube, it is preferable to use a plurality of reforming reaction tubes. In this case as well, all the reforming reaction tubes are straight pipes, the tubular burner is also a straight pipe, and all these pipes are arranged in parallel with each other. It is preferable from the viewpoint of heating well.

  The number of tubular burners can be determined as appropriate so that the reforming reaction tube to be heated can be efficiently heated.

  In order to heat the reforming reaction tube as uniformly as possible, a plurality of flame holes are provided in one tubular burner. In particular, in order to heat the reforming reaction tube as uniformly as possible in the axial direction, it is preferable to provide a plurality of flame holes in the axial direction of a tubular burner arranged in parallel with the reforming reaction tube. When a plurality of reforming reaction tubes exist around one tubular burner, a plurality of flame holes can be provided in the circumferential direction of the tubular burner so that flames can be blown out toward each reforming reaction tube. .

  The sizes (hole diameters) of the plurality of flame holes need not be the same. Further, when three or more flame holes are provided in the axial direction of one tubular burner, it is not necessary to provide the flame holes at equal intervals. The size and arrangement of the flame holes may be appropriately determined from the viewpoint of heating the reforming reaction tube as uniformly and efficiently as possible.

  The tubular burner can be supplied with a premixed gaseous combustible and oxygen-containing gas.

[Reforming catalyst]
To perform steam reforming or autothermal reforming in the reforming reaction tube, use a steam reforming catalyst or autothermal reforming catalyst (a catalyst having steam reforming ability and partial oxidation reforming ability) as a reforming catalyst. Can do. That is, a catalyst having steam reforming ability for steam reforming hydrocarbon fuel can be used as the reforming catalyst.

  Both the steam reforming catalyst and the autothermal reforming catalyst can be used by appropriately selecting from known respective catalysts. Examples of the steam reforming catalyst include ruthenium-based and nickel-based catalysts, and examples of the autothermal reforming catalyst include rhodium-based catalysts. As for the autothermal reforming catalyst, JP 2000-84410 A, JP 2001-80907 A, “2000 Annual Progress Reports (Office of Transportation Technologies)”, US Pat. No. 5,929,286, and the like. As described, nickel and noble metals such as platinum, rhodium and ruthenium are known to have these activities. As the catalyst shape, a pellet shape, a honeycomb shape, or other conventionally known shapes can be appropriately employed.

  When partial oxidation reforming is performed in the reforming reaction tube (steam reforming is not performed), the partial oxidation reforming reaction is an exothermic reaction, and thus it is basically unnecessary to heat the reforming reaction tube. However, when using a partial oxidation reforming catalyst, it is necessary to raise the temperature of the catalyst to a temperature at which the activity of the partial oxidation reforming catalyst is manifested. For this reason, the reforming reaction is performed using a flame blown from the flame hole of the tubular burner. The tube can be heated.

[Reforming conditions]
Hereinafter, conditions during power generation will be described for each of steam reforming and autothermal reforming.

  The reaction temperature of the steam reforming can be, for example, in the range of 450 ° C to 900 ° C, preferably 500 ° C to 850 ° C, and more preferably 550 ° C to 800 ° C.

The amount of steam introduced into the reaction system is defined as the ratio of the number of moles of water molecules to the number of moles of carbon atoms contained in the reforming raw material (steam / carbon ratio), and this value is preferably 0.5 to 10, more preferably. Is 1-7, more preferably 2-5. When the reforming raw material is liquid, the space velocity (LHSV) at this time is represented by A / B when the flow rate in the liquid state of the reforming raw material is A (L / h) and the catalyst layer volume is B (L). This value is preferably set in the range of 0.05 to 20 h ⁻¹ , more preferably 0.1 to 10 h ⁻¹ , still more preferably 0.2 to 5 h ⁻¹ .

  The reaction temperature of the autothermal reforming reaction is set in the range of, for example, 450 ° C to 900 ° C, preferably 500 ° C to 850 ° C, and more preferably 550 ° C to 800 ° C.

  In autothermal reforming, an oxygen-containing gas is added to the raw material in addition to steam. The oxygen-containing gas may be pure oxygen, but air is preferred because of its availability. An oxygen-containing gas can be added so as to obtain a desired calorific value. The addition amount of the oxygen-containing gas is preferably 0.05 to 1, more preferably 0.1 to 0.75, as a ratio of the number of moles of oxygen molecules to the number of moles of carbon atoms contained in the reforming raw material (oxygen / carbon ratio). More preferably, it is 0.2 to 0.6. When the reforming raw material is liquid, the space velocity (LHSV) at this time is preferably selected in the range of 0.1 to 30, more preferably 0.5 to 20, and still more preferably 1 to 10. The amount of steam introduced into the reaction system is preferably 0.3 to 10, more preferably 0.5 to 5, and still more preferably 1 to 3 as a steam / carbon ratio.

[SOFC]
The reformed gas obtained from the reformer, particularly from the reforming reaction tube, is supplied to the anode (fuel electrode) of the SOFC. On the other hand, an oxygen-containing gas such as air is supplied to the cathode (air electrode) of the SOFC. The SOFC generates heat with power generation, and the heat is radiated from the SOFC to the reformer. Thus, the SOFC exhaust heat is utilized for the endothermic reaction of the reforming reaction. Gas exchange and the like are appropriately performed using piping or the like.

  As the SOFC, known SOFCs of various shapes such as a flat plate type and a cylindrical type can be appropriately selected and employed. In the SOFC, oxygen ion conductive ceramics or proton ion conductive ceramics are generally used as an electrolyte.

  The SOFC may be a single cell, but in practice, a stack in which a plurality of single cells are arranged (in the case of a cylindrical type, sometimes referred to as a bundle, but the stack in this specification includes a bundle) is preferable. Used. In this case, one or more stacks may be used. The SOFC and the reformer can be accommodated in a container such as a can and modularized.

  The reforming reaction tube is preferably arranged at a position where direct heat transfer from the SOFC to the outer surface of the reforming reaction tube is possible. Therefore, it is preferable that a shielding object is not substantially disposed between the reforming reaction tube and the SOFC, that is, a gap is provided between the reforming reaction tube and the SOFC. Moreover, it is preferable to shorten the distance between the reforming reaction tube and the SOFC as much as possible.

  Each supply gas is appropriately preheated as necessary, and then supplied to the reforming reaction tube or the SOFC.

  In the present invention, a reformer having a structure in which a part of the multi-tube reformer installed in the vicinity of the solid oxide fuel cell is replaced with a tubular burner is used. The tubular burner has, for example, a structure in which one side is sealed and several flame holes are formed in the side wall surface, and flame is blown out from the flame holes.

  A flame comes out from the tubular burner, and the reforming reaction tube, which is preferably installed in parallel around the tubular burner, receives the direct fire and the heat of the combustion gas, so that the reforming reaction tube is warmed evenly at an early stage. It becomes possible. Further, when such a reformer is used, the shape of the solid oxide fuel cell to be combined is not particularly limited, and any shape can be supported. In the present invention, it is possible to use a reforming reaction tube having a shape corresponding to an SOFC having an arbitrary shape, and it is possible to use a tubular burner that is parallel to the axial direction.

[Start-up operation]
・ When vaporizing combustibles (fuel in tubular burners) When liquid combustibles are vaporized at room temperature and normal pressure (25 ° C, 0.101 MPa) such as kerosene and then supplied to the tubular burner, the tubular burner will be used in start-up operation Prior to combustion, the liquid combustible can be vaporized by heating the liquid combustible vaporizer to a temperature at which the liquid combustible can be vaporized. In such a case, an auxiliary burner can be provided separately from the tubular burner, and the liquid combustible can be heated by using the auxiliary combustor to burn the liquid combustible and heat. Specifically, the combustion gas of the auxiliary burner can be led to the liquid combustible vaporizer.

  The liquid combustible material vaporizer is heated by the auxiliary burner, the liquid combustible material is vaporized, supplied to the combustion gas tubular burner and burned, and the reforming reaction tube can be heated by the combustion heat. When the reforming reaction tube reaches a reformable temperature, hydrocarbon-based fuel and steam as required are supplied to the reforming reaction tube to produce reformed gas, and the reformed gas is supplied to the SOFC. it can.

  When it is necessary to vaporize the feed to the reforming reaction tube such as hydrocarbon fuel or water, the combustion heat of the auxiliary burner can be used to heat the vaporizer that vaporizes them. Furthermore, when preheating the feed to the reforming reaction tube such as hydrocarbon fuel or water, the combustion heat of the auxiliary burner can be used for this preheating. There are cases where the combustion gas generated in the tubular burner and heated after the reforming reaction tube is used to vaporize or preheat the feed to the reforming reaction tube.

  The SOFC can be heated using combustion heat obtained by burning anode off-gas discharged from the anode of the SOFC (when the power generation is not performed, the anode off-gas is substantially the same as the reformed gas). For example, the SOFC can be heated by burning the anode off-gas discharged from the SOFC at the cell outlet. At the same time, the reforming reaction tube can be heated by combustion of the anode off gas at the cell outlet. An igniter can be appropriately provided near the anode outlet of the SOFC for ignition. Alternatively, the anode off gas is taken out of the indirect internal reforming SOFC module and combusted, and the combustion gas is introduced into the indirect internal reforming SOFC module to heat the SOFC, and further the reforming reaction tube is heated. You can also

  When the SOFC reaches a temperature at which power generation is possible, power generation is started, and the SOFC can be heated by heat generated by power generation.

  When the reforming reaction tube is heated by the heat from the SOFC and the heat necessary for reforming can be provided, the combustion of the tubular burner can be stopped.

・ When the combustible material (fuel of the tubular burner) is not vaporized When the combustible material used as the fuel for the tubular burner is originally in a gaseous state, it is not necessary to vaporize the combustible material.

  In this case, it is possible to perform combustion with a tubular burner from the beginning of the starting operation. Combustion is performed with a tubular burner, the reforming reaction tube is heated with the combustion gas, and when the reforming reaction tube reaches a temperature capable of reforming, hydrocarbon fuel and steam are supplied to the reforming reaction tube for reforming. Gas can be produced and reformed gas can be supplied to the SOFC.

  When it is necessary to vaporize the feed to the reforming reaction tube such as hydrocarbon fuel or water, the combustion heat of the auxiliary burner can be used to heat the vaporizer that vaporizes them. Furthermore, when preheating the feed to the reforming reaction tube such as hydrocarbon fuel or water, the combustion heat of the auxiliary burner can be used for this preheating. There are cases where the combustion gas generated in the tubular burner and heated after the reforming reaction tube is used to vaporize or preheat the feed to the reforming reaction tube.

  The heating of the SOFC can be performed in the same manner as the heating of the SOFC in the case where the combustible material (fuel of the tubular burner) is vaporized.

〔Normal operation〕
In normal operation (rated operation or partial load operation), if the heat required for the reforming reaction is insufficient due to some factor, the tubular reaction burner can be activated and the reforming reaction tube can be heated by the flame blown out from the flame hole. .

  When it is necessary to vaporize the combustible material used as the fuel for the tubular burner, a vaporizer for vaporizing the combustible material can be provided at a location that is always heated during normal operation. For example, this vaporizer can be provided inside the indirect internal reforming SOFC module. By doing so, it becomes possible to vaporize combustibles immediately when necessary.

  When using the same type of combustible material as the hydrocarbon fuel, the hydrocarbon fuel is vaporized and then supplied to the reforming reaction tube. Therefore, the vaporized hydrocarbon fuel is branched to form a tubular burner. It can also be used as fuel.

[Example 1]
FIG. 1 schematically shows an example of the indirect internal reforming SOFC of the present invention. Here, kerosene is used as the hydrocarbon fuel, and the kerosene is steam reformed. In a tubular burner, vaporized kerosene is burned using air.

  A plurality of reforming reaction tubes 1 are arranged at positions where heat radiation can be received from the SOFC stack 11. The reforming reaction tube is a straight tube and a single tube, and has a catalyst layer filled with a steam reforming catalyst. Kerosene and water vapor previously vaporized are supplied from one end (right end of the paper) of the reforming reaction tube, and the reformed gas is discharged from the other end (left end of the paper). The reformed gas is supplied to the SOFC anode through a pipe (not shown).

  The plurality of tubular burners 2 are supplied with pre-vaporized kerosene and air. The tubular burner is closed at one end (the left end on the paper surface), and a plurality of flame holes 4 are provided in the axial direction on the side wall. Also, a plurality of flame holes are provided in the circumferential direction, and flames can be blown out toward a plurality of adjacent reforming reaction tubes.

  In this example, the tubes (reforming reaction tubes and tubular burners) are arranged in two rows parallel to each other, the tube row closer to the SOFC stack is composed of only the reforming reaction tubes, and part of the far side tube row Has a structure that is a tubular burner. In the tube row on the far side, the tubular burner is provided at a position sandwiched between the reaction tubes.

  Further, the flow direction of the reformed gas and the flow direction of the combustible material are the same direction.

  The reforming reaction tube 1, the tubular burner 2, and the SOFC stack 11 are housed in a container (module container) (not shown) and modularized.

  In addition, a kerosene vaporizer that vaporizes kerosene, a kerosene preheater that preheats vaporized kerosene and supplies it to the reforming reaction tube, a water vaporizer that vaporizes water, and water vapor generated in the water vaporizer is preheated. A steam preheater for supplying to the reforming reaction tube and an air preheater (both not shown) for preheating the air supplied to the air electrode are also provided in the module container and heated by radiant heat from the SOFC to achieve the desired vaporization. And preheating is possible.

  During normal operation, heat is supplied from the SOFC to the reforming reaction tube by heat radiation. Further, the anode off gas discharged from the SOFC anode may burn near the SOFC cell outlet, and the reforming reaction tube may be heated by the combustion heat. Thus, when the heat required for the steam reforming reaction is provided by the heat supplied from the SOFC, combustion in the tubular burner 2 is unnecessary.

  When starting up, combustion gas of an auxiliary burner (not shown) is led to a kerosene vaporizer, a kerosene preheater, a water vaporizer, and a steam preheater to heat them. When the kerosene vaporizer reaches the temperature at which kerosene can be vaporized, the kerosene is introduced into the kerosene vaporizer, the kerosene is vaporized, the vaporized kerosene and air are guided to the tubular burner, and combustion is performed while blowing out the flame from the flame hole 4 for reforming. The reaction tube 1 is heated.

  The kerosene supplied to the kerosene vaporizer can be desulfurized in advance.

  When the reforming reaction tube reaches a temperature at which reforming can be performed (the temperature at which the reforming catalyst becomes active) and the kerosene preheater, water vaporizer, and steam preheater reach the desired temperature, preheated vaporized kerosene (Kerose through the kerosene vaporizer and kerosene preheater) and preheated steam (steam through the water vaporizer and steam preheater) are introduced into the reforming reaction tube. The heating of the reforming reaction tube by the flame from the flame hole 4 is continued, and the reformed gas is produced in the reforming reaction tube.

  The reformed gas is guided to the SOFC, and when the reformed gas is discharged from the anode outlet of the SOFC cell, it is ignited using an igniter (not shown). The reformed gas burns near the anode outlet, and the SOFC is heated.

  When the SOFC reaches the desired temperature, power generation can be started. The air supplied to the SOFC cathode can be appropriately preheated by the heat generated by the auxiliary burner or the heat held by the gas discharged from the SOFC. If necessary, the SOFC is further heated by the heat generated by power generation, and normal operation becomes possible.

  During normal operation, if the temperature of the reforming reaction tube (reforming catalyst) decreases due to some factor, vaporized kerosene is supplied from the kerosene vaporizer to the tubular burner, burned using air, and the reforming reaction tube is heated. To do. The kerosene vaporizer is heated because it is inside the indirect internal reforming SOFC module, and vaporized kerosene can be supplied to the tubular burner as needed.

[Example 2]
FIG. 2 shows another example of the indirect internal reforming SOFC of the present invention. In this example, the flow of reformed gas and the flow of combustible material (tubular burner fuel) are opposite. The vaporized kerosene serving as fuel for the tubular burner 2 flows through the tubular burner from the left to the right of the page. The rest is the same as the example shown in FIG. As shown in the first and second embodiments, since the position of the combustion gas generating burner can be selected, the degree of freedom in the layout design of other devices not shown is high.

Example 3
FIG. 3 shows still another example of the indirect internal reforming SOFC of the present invention. There are three tube rows, a part of the middle tube row is a tubular burner, and the remaining tubes are reforming reaction tubes. In the example of FIG. 1, a structure in which one row of tube rows is added above the plane of the drawing. A flame hole is added to the tubular burner so that the flame is blown out toward the tube row above the paper surface. The rest is the same as the example shown in FIG. As shown in Examples 1 and 3, since the number of tube rows can be changed, it is expected that the degree of freedom in designing the amount of reforming catalyst is increased.

Example 4
FIG. 4 shows still another example of the indirect internal reforming SOFC of the present invention. In the example shown in FIG. 3, the flow of the reformed gas and the flow of the combustible material (tubular burner fuel) are opposite to each other. The vaporized kerosene serving as fuel for the tubular burner 2 flows through the tubular burner from the left to the right of the page. The rest is the same as the example shown in FIG.

  The indirect internal reforming SOFC of the present invention can be used for, for example, a stationary or moving power generation system and a cogeneration system. The reformer of the present invention can be suitably used for such an indirect internal reforming SOFC.

It is a schematic diagram which shows an example of the indirect internal reforming SOFC of the present invention. It is a schematic diagram which shows another example of the indirect internal reforming type | mold SOFC of this invention. It is a schematic diagram which shows another example of the indirect internal reforming type | mold SOFC of this invention. It is a schematic diagram which shows another example of the indirect internal reforming type | mold SOFC of this invention.

Explanation of symbols

1 reforming reaction tube 2 tubular burner 4 flame hole 11 SOFC

Claims (4)

A reforming reaction tube for reforming a fuel containing carbon and hydrogen in the molecule ;
A tubular burner with a plurality of flame holes in the tube wall;
A solid oxide fuel cell that generates power using the reformed gas obtained from the reforming reaction tube;
Tubular burner, radiant heat and / or combustion gases from the flame blown out from said inflammatory holes are arranged in a position corresponding to the reforming reaction tube,
An indirect internal reforming solid oxide fuel cell in which the reforming reaction tube is disposed at a position where it receives heat radiation from the solid oxide fuel cell. The indirect internal reforming solid oxide fuel cell according to claim 1, wherein the reforming reaction tube contains a catalyst having a steam reforming ability for steam reforming a fuel containing carbon and hydrogen in a molecule . The reforming reaction tube and the tubular burner are both straight tubes,
A plurality of the reforming reaction tubes;
The indirect internal reforming solid oxide fuel cell according to claim 1 or 2, wherein the reforming reaction tube and the tubular burner are arranged in parallel to each other. A method for starting an indirect internal reforming solid oxide fuel cell according to any one of claims 1 to 3,
  A step of heating the reforming reaction tube by performing combustion in the tubular burner and applying radiant heat and / or combustion gas from a flame blown out of the flame hole to the reforming reaction tube;
  When the reforming reaction tube reaches a reformable temperature, fuel containing carbon and hydrogen in the molecule is supplied to the reforming reaction tube to produce reformed gas, and the reformed gas is used as the solid oxide fuel cell. The process of supplying to
  Starting the power generation when the solid oxide fuel cell reaches a temperature capable of generating power, and heating the solid oxide fuel cell by heat generated by the power generation; and
  A step of stopping combustion of the tubular burner when the reforming reaction tube is heated by the heat from the solid oxide fuel cell and the heat necessary for reforming can be provided
A method for starting an indirect internal reforming solid oxide fuel cell comprising:

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