JP2013134929A - Fuel battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel battery which causes battery cells to rise the temperatures to the power generation temperature in a shorter time compared to conventional fuel batteries and does not require a special heater only for a partial oxidation reformer.SOLUTION: A fuel battery includes: a housing 2 where a space is formed therein; a steam generator 4 disposed in the space; a heat exchanger 5 disposed above the steam generator 4 in the space; a steam reformer 10 disposed in the space so as to be adjacent to the lateral side of the steam generator 4 and the heat exchanger 5; a radiant tube burner 20 formed by a burner 21 and a radiant tube 22 and in which the radiant tube 22 is disposed at a position that faces the steam generator 4 and the heat exchanger 5 across the steam reformer 10 in the space; a battery stack 30 disposed at a position that faces the steam reformer 10 across the radiant tube 22 in the space; and a partial oxidation reformer 40 attached along the radiant tube 22.

Description

  The present invention relates to a fuel cell that generates power by reacting a fuel gas having a high hydrogen gas content with an oxidizing gas.

  One of the fuel cells is a solid oxide fuel cell. This solid oxide fuel cell includes a battery cell having a structure in which an anode electrode layer (fuel electrode layer) and a cathode electrode layer (air electrode layer) are formed on both sides of a solid electrolyte layer. The fuel gas is supplied to the layer side and the oxidizing gas is supplied to the cathode electrode layer side to generate an electrochemical reaction, thereby generating power.

  In such a solid oxide fuel cell, as the fuel gas, a reformed fuel gas obtained by reforming a hydrocarbon gas to increase the content of hydrogen gas is used. Is generated by a reformer provided in the solid oxide fuel cell. Further, such a solid oxide fuel cell includes a preheating device for preheating the battery cell to a temperature at which an electrochemical reaction proceeds, that is, a power generation temperature (usually 700 to 800 ° C.).

  As one of the solid oxide fuel cells, a fuel cell disclosed in Japanese Patent Application Laid-Open No. 2008-218277 is conventionally known.

  Such a conventional fuel cell includes an internal can body in which a power generation reaction chamber maintained in an airtight state is formed, a preheating burner for activation provided on four outer surfaces of the internal can body, and the power generation reaction. A plurality of fuel cell stacks (a stack of a plurality of the battery cells) installed in the room, a fuel heat exchanger for heating the fuel gas, and air heat for heating the air, also provided in the power generation reaction chamber It is comprised from the exchanger, the fuel reformer which reforms fuel gas, and the water vapor generator provided under the said internal can body.

  The fuel cell stacks are arranged in two rows in the vertical and horizontal directions so as to have a predetermined interval between the side surfaces, and the fuel reformer is arranged between the side surfaces.

  The preheating burner is disposed at a position facing the fuel cell stack across the side surface of the inner can body, and the fuel cell stack is disposed between the fuel cell stack and the side surface of the inner can body. A heat shield for preventing direct reception of radiant heat from the preheating burner is provided. Similarly, the fuel heat exchanger and the air heat exchanger are arranged at positions where they do not directly receive the radiant heat from the preheating burner.

  Thus, in this fuel cell, the internal atmosphere in the power generation reaction chamber is heated by the preheating burner, and the fuel cell stack, the fuel heat exchanger, and the air heat exchanger disposed in the power generation reaction chamber are heated. Heated by the internal atmosphere. Further, the reformer disposed between the fuel cell stacks is heated by the fuel cell stack and the internal atmosphere. In this way, the fuel cell stack, the fuel heat exchanger, the reformer, and the air heat exchanger are each indirectly heated by the preheating burner.

  In the conventional fuel cell having the above configuration, at the time of starting the operation, first, the preheating burner is operated to raise the temperature in the power generation reaction chamber, and water is supplied to the steam generator, and the fuel gas is supplied. It is mixed with the steam generated by the steam generator and supplied to the fuel heat exchanger, and air is supplied to the air heat exchanger.

  The fuel gas is heated by mixing with the high-temperature steam supplied from the steam generator, and then further heated by being sequentially introduced into the fuel heat exchanger and the reformer. The reformed fuel gas is supplied to the fuel cell stack. On the other hand, air is similarly heated by being introduced into the air heat exchanger, and the heated air is supplied to the fuel cell stack.

  Thus, at the time of start-up, the fuel cell stack is indirectly heated by the preheating burner, and the fuel cell stack is also heated by supplying the heated reformed fuel gas and air.

  When the fuel cell stack reaches the power generation temperature due to such preheating, a normal operation state in which efficient power generation is performed thereafter is entered.

JP 2008-218277 A

  However, in the conventional fuel cell described above, the fuel cell stack is heated indirectly by the preheating burner, that is, through the internal atmosphere in the power generation reaction chamber, so that there is a problem that the thermal efficiency is extremely poor. Since it takes a long time to raise the internal atmosphere, there is a problem that it is inefficient in terms of energy efficiency.

  In addition, in order to obtain a high quality reformed fuel gas (hydrogen-rich fuel gas) by the reformer, it is necessary to sufficiently heat the reformer (usually about 700 ° C.). However, because the reformer is heated by heat conduction and / or radiant heat from the fuel cell stack, it takes a long time to raise the temperature for the same reason as described above. Was inefficient.

  In addition, in the conventional solid oxide fuel cell, there is a known problem that the anode electrode layer is oxidized during the operation start period and the operation stop period. In addition to the reformer, for example, a partial oxidation reformer is provided that partially oxidizes the fuel gas and reforms it into a gas containing a reducing gas by using an electric heater or the like as a heating device. The fuel gas is reformed by the partial oxidation reformer and the generated reducing gas is supplied to the anode electrode layer. For such partial oxidation reforming, heating is performed separately from the preheating burner. There was also the problem of requiring equipment.

  The present invention has been made in view of the above circumstances, and can increase the temperature of a battery cell to a power generation temperature in a shorter time than conventional, and a special heating device only for a partial oxidation reformer. The purpose is to provide a fuel cell that does not need to be provided.

The present invention for solving the above problems is as follows.
A steam reforming device comprising a combustion section, and steam reforming the fuel gas by the combustion heat generated in the combustion section;
A battery stack having a cathode and an anode, and comprising a battery cell that generates power by an electrochemical reaction between an oxidizing gas supplied to the cathode and a reformed fuel gas supplied from the steam reformer supplied to the anode In a fuel cell comprising: the battery cells stacked to form a single structure, including a case where the battery cell is housed in a cover can.
The present invention relates to a fuel cell in which a radiant tube burner including a burner for burning fuel gas and a radiant tube connected to the burner is disposed between the battery stack and the steam reformer.

  According to the fuel cell of the present invention, when starting the fuel cell, first, the fuel gas is combusted by the burner, the radiant tube is heated by the combustion gas generated thereby, and the radiant heat irradiated from the radiant tube is used. Preheat battery stack and steam reformer. At this time, since the radiant tube is disposed between the battery stack and the steam reformer, the battery stack and the steam reformer are each directly heated.

  When the battery cells in the battery stack and the steam reformer are sufficiently heated to reach a temperature at which efficient power generation can be performed, heating by the radiant tube is stopped, and the fuel cell is in a normal operation mode. Migrate to

  Thus, according to the present invention, each of the steam reformer and the battery stack can be directly heated, so that the temperature raising time can be shortened compared to the conventional case, and the energy efficiency can be increased.

  In the present invention, at least a part of the radiant tube may be bent or curved in a spiral shape, a meandering shape, a saddle shape, or a U shape.

  In this way, the surface area of the radiant tube is increased, and the amount of radiant heat irradiated from the radiant tube is increased, so that the steam reformer and the battery stack can be efficiently heated. Thereby, further shortening of the time required for temperature rising can be achieved. In addition, the planar area occupied by the radiant tube is widened, the steam reformer and the battery stack can be heated in a wide range, and the battery cells inside the steam reformer and the battery stack are heated evenly and uniformly. Can be made.

  Alternatively, the radiant tube may be bent or curved in a substantially annular shape as a whole. Thus, by bending or curving in an annular shape, the planar area occupied by the radiant tube becomes wider, and the steam reformer and the battery stack can be heated in a wider range. It is possible to raise the temperature of each internal battery cell more uniformly and without unevenness.

  In addition, since the space is formed inside the ring by making the radiant tube into an annular shape, radiant heat is irradiated to the battery stack from the steam reformer heated to a high temperature by the combustion section through the space, and the fuel Even if the radiant tube burner is stopped during normal operation of the battery, the temperature of each battery cell in the battery stack can be maintained at an appropriate power generation temperature.

  Moreover, in this invention, the exhaust side of the said radiant tube may be connected to the combustion part of a steam reformer, and it may be comprised so that the combustion gas of a radiant tube may be supplied to the said combustion part.

  In this way, since the high-temperature combustion gas is supplied to the combustion section of the steam reformer, the steam reforming is performed by the radiant heat irradiated from the radiant tube and the high-temperature combustion gas supplied from the exhaust side of the radiant tube. The quality device can be heated and heated more efficiently.

  Furthermore, the fuel cell according to the present invention may have a configuration in which a partial oxidation reforming device for partial oxidation reforming of a fuel gas and supplying the fuel gas to the anode of the battery cell is attached to the radiant tube.

  As described above, in the fuel cell, in order to prevent the oxidation of the anode in the operation start period and the operation stop period, the fuel gas is partially oxidized and reformed by the partial oxidation reforming apparatus, and the reducing gas obtained by the reforming However, by attaching this partial oxidation reforming device to the radiant tube, the fuel gas can be reformed by heat conduction and radiant heat from the radiant tube. Therefore, the fuel gas can be partially oxidized and reformed without providing a separate heating device in the partial oxidation reforming apparatus, and energy efficiency can be improved. In addition, the fuel cell can be reduced in size and simplified.

The partial oxidation reformer is
A cylindrical body spaced around the radial direction of the radiant tube and provided around the axis of the radiant tube;
The radiant tube comprises two lid members respectively fixed to both ends of the cylindrical body in a state of penetrating the front and back.
A supply port through which the fuel gas is supplied to the reaction chamber surrounded by the radiant tube, the cylinder, and the two cover members is formed in one end of the cylinder or the lid member fixed to the one end. And
The lid member fixed to the other end of the cylindrical body or the other end may be configured to have a discharge port through which fuel gas partially oxidized and reformed in the reaction chamber is discharged.

  According to the partial oxidation reforming apparatus having such a configuration, the fuel gas is supplied from a supply port formed in one end of the cylindrical body or a lid member fixed to the one end, and from the radiant tube in the reaction chamber. After being partially oxidized and reformed by heat conduction and radiant heat, it is discharged from the other end of the cylinder or a discharge port formed in a lid member fixed to the other end.

  At that time, since the reaction chamber is a cylindrical space in which the radiant tube is arranged at the center, the fuel gas supplied to the reaction chamber receives heat conduction and radiant heat from the entire circumference of the radiant tube, Reformed efficiently.

  In addition, since the supply port and the discharge port are formed at opposite ends of the reaction chamber, it is possible to take a sufficiently long process for the fuel gas supplied to the supply port to reach the discharge port. In this case, the fuel gas can be sufficiently reformed.

In the partial oxidation reforming apparatus, the reaction chamber is divided into two spaces by a partition plate disposed in the reaction chamber, and the supply port is connected to one space, The outlet is connected to the space,
The partition plate may have a communication hole that allows the space on the supply port side and the space on the discharge port side to communicate with each other.

  According to this configuration, the fuel gas supplied from the supply port circulates in the space on the supply port side, passes through the communication hole formed in the partition plate, and moves to the space on the discharge port side. It is discharged from the outlet. As described above, by moving the fuel gas through the communication hole, the residence time of the fuel gas in each of the divided reaction chambers can be increased, and the fuel gas can be reformed more efficiently. Can do.

Further, the partial oxidation reforming apparatus includes a plurality of annular rings formed in the reaction chamber along the axial direction of the radiant tube by one or a plurality of partition plates disposed in the reaction chamber. While being divided into spaces, in the axial direction, the supply port is connected to one of the spaces at both ends thereof, and the discharge port is connected to the other.
The partition plate may have a communication hole that allows adjacent spaces to communicate with each other.

  Even with such a configuration, since the movement of the fuel gas is performed through the communication hole, the residence time of the fuel gas in each reaction chamber can be increased, and the fuel gas can be reformed more efficiently. can do. If the reaction chamber is divided into three or more spaces, the residence time of the fuel gas in the reaction chamber can be further increased, and reforming can be performed more efficiently.

Furthermore, in each annular space in the reaction chamber, a partition wall that blocks the circumferential communication state is provided,
The partition walls are arranged in a line along the axial direction of the radiant tube,
The supply port, the communication hole, and the discharge port are disposed at positions close to the partition wall, and are sequentially disposed at staggered positions along the axial direction of the radiant tube with the partition wall interposed therebetween. It is good also as a structure.

  In this way, the fuel gas supplied to the space on the one end side flows in each reaction chamber so as to bypass the radiant tube so as to avoid the partition wall, and finally from the discharge port. Discharged. Therefore, the process from the supply port to the discharge port can be made longer, and the time for the fuel gas to stay in the reaction chamber can be made longer. More efficient reforming can be achieved.

Further, the fuel cell according to the present invention has a space surrounded by a heat insulating member and thermally blocked from the outside,
In the space, the steam reformer, the battery stack and the radiant tube are disposed,
One end of the partial oxidation reforming apparatus may be exposed in the space, and the other end may be embedded in the heat insulating member.

  By disposing the steam reformer, the battery stack, and the radiant tube in the space, the steam reformer and the battery stack can be efficiently heated by the radiant heat irradiated from the radiant tube.

  When the steam reformer, the battery stack, and the radiant tube are arranged in the space as described above, at least a part of the partial oxidation reformer is partially exposed in the space from the viewpoint of thermal efficiency. Preferably.

  As a result, during normal operation with the radiant tube burner stopped, the partial oxidation reformer exposed in the space is heated by the radiant heat radiated from the steam reformer and is necessary for partial oxidation reforming. Temperature (usually 600 ° C.).

  Thus, in the shutdown period, the reformed gas can be obtained quickly by supplying the fuel gas to the partial oxidation reformer without burning the radiant tube burner. Therefore, the supply of the fuel gas to the steam reformer can be stopped, and the mode can be quickly shifted to the stop mode.

  The partial oxidation reforming device is partially exposed because when the partial oxidation reforming device is exposed, the radiant heat radiated from the steam reforming device is used. In this case, the partial oxidation reforming apparatus is heated more than necessary, and this amount of heat is connected to the partial oxidation reforming apparatus from the outside. This is because heat is radiated to the outside through other members that cause waste of heat energy.

  As described above, according to the fuel cell of the present invention, the radiant tube burner is disposed between the steam reformer and the battery stack, so that the steam reformer is radiated by the radiant heat irradiated from the radiant tube. The battery stack can be directly heated, and the time required for the temperature rise can be shortened. Furthermore, by attaching the partial oxidation reforming device to the radiant tube, it is possible to reform the fuel gas without providing a separate heating device in the partial oxidation reforming device. Miniaturization and simplification can be achieved. Furthermore, by exposing at least a part of the partial oxidation reforming device to a space irradiated with radiant heat from the steam reforming device, the partial oxidation reforming device can always generate a reformed gas after normal operation. Can be maintained, and a quick transition to the stop mode is possible.

1 is a perspective view showing a schematic configuration of a fuel cell according to an embodiment of the present invention. 1 is a piping diagram showing a schematic configuration of a fuel cell according to an embodiment of the present invention. It is a fragmentary sectional view which shows the structure of a partial oxidation reforming apparatus. It is sectional drawing between AA in FIG. It is sectional drawing between CC in FIG. It is sectional drawing between DD in FIG. It is sectional drawing between EE in FIG.

  Hereinafter, a fuel cell according to a specific embodiment of the present invention will be described with reference to FIGS. 1 to 7.

  As shown in FIGS. 1 and 2, the fuel cell 1 of the present example includes a housing 2 in which a space 3 is formed, a water vapor generator 4 disposed in the space 3, and the space 3. The heat exchanger 5 disposed above the water vapor generator 4 and the water vapor disposed in the space 3 so as to be adjacent to the side of the water vapor generator 4 and the heat exchanger 5. The reformer 10 includes a burner 21 and a radiant tube 22, and the radiant tube 22 faces the steam generator 4 and the heat exchanger 5 with the steam reformer 10 sandwiched in the space 3. A radiant tube burner 20 disposed at a position, and a cylindrical battery stack 30 (a plurality of batteries) disposed at a position facing the steam reformer 10 with the radiant tube 22 interposed in the space 3. Cell stacks Obtained by a single structure, in this example, which as a are accommodated in the cover can body), and a partial oxidation reformer 40 that is attached to the radiant tube.

  The housing 2 is made of a heat insulating material, and the space 3 is a space thermally insulated from the outside.

  The water vapor generator 4 is an apparatus for generating pure water and anode fuel gas from outside through appropriate piping and generating water vapor from the supplied pure water. Further, the generated steam is mixed with anode fuel gas and supplied to the steam reformer 10 through an appropriate pipe.

  The heat exchanger 5 is a device that preheats cathode air supplied from the outside via a pipe as appropriate, and the preheated cathode air is appropriately connected to a cathode electrode layer side space (to be described later) of the battery cell via the pipe. 32.

  The steam reforming apparatus 10 includes a reforming unit 11 that performs steam reforming, and a combustion unit 12 that generates heat necessary for steam reforming. The reformer 11 steam-reforms the anode fuel gas supplied as the mixed gas from the steam generator 4 with steam to obtain a steam-reformed fuel gas. Then, the steam reformed fuel gas is supplied to an anode electrode layer side space 31 (to be described later) of the battery cell through an appropriate pipe.

  The combustion section 12 is connected to the heat exchanger 5 by piping or the like as appropriate, exhaust gas is supplied from the combustion section 12 to the heat exchanger 5, and exhaust gas supplied to the heat exchanger 5 is further supplied. The gas is supplied to the water vapor generating device 4 through piping as appropriate.

  Thus, the steam generator 4 exchanges exhaust gas with pure water to generate steam, and the heat exchanger 5 exchanges heat of the exhaust gas with cathode air to convert the cathode air into the cathode air. Preheat. The steam generator 4 and the heat exchanger 5 are also heated by the radiant heat emitted from the heated steam reformer 10.

  The radiant tube burner 20 includes the burner 21 and the radiant tube 22 as described above. The burner 21 is embedded in the bottom of the housing 2 and burner fuel gas and burner air are supplied from outside through appropriate piping. In addition, the radiant tube 22 is a U-shaped tube material, the curved portion is up, and one end of the radiant tube 22 is disposed in the bottom of the housing 2 in the space 3. Further, the one end is connected to the tip of the burner 21, and the other end is connected to the combustion unit 12 of the steam reformer 10. The steam reformer 10 and the battery stack 30 communicate with each other through a space 22 a between the radiant tubes 22.

  Thus, by burning the burner fuel gas by the burner 21, high-temperature exhaust gas is circulated through the radiant tube 22 and then discharged to the combustion section 12 of the steam reformer 10. An example of the burner 21 is a pilot burner.

  The battery cell has a structure in which a solid electrolyte plate on which an anode electrode layer and a cathode electrode layer are formed is sandwiched between interconnectors, and a stack of a plurality of these is the above-described battery stack. Further, the battery cell is configured such that the steam reformed fuel gas is supplied to the anode electrode layer side space 31 and the cathode air is supplied to the cathode electrode side space 32, and the anode electrode layer, the cathode electrode layer, Electricity is generated by an electrochemical reaction between the two.

  Exhaust gas (reacted steam reformed fuel gas, unreacted steam reformed fuel gas and cathode air) discharged from the anode electrode layer side space 31 and the cathode electrode layer side space 32 is appropriately routed through piping. Is supplied to the combustion section 12 of the steam reforming apparatus 10 and burned.

  The partial oxidation reforming apparatus 40 is an apparatus for partially oxidizing and reforming a fuel gas using air (reforming so as to include a reducing gas) to obtain a partially oxidized reformed fuel gas. As shown in the above, in a state where the radial tube of the radiant tube 22 is spaced radially outward and circumferentially provided along the axial direction of the radiant tube 22, the radiant tube 22 penetrates the front and back, respectively. A lower lid member 42 fixed to one end portion of the cylindrical body 41, an upper lid member 43 fixed to the other end portion of the cylindrical body 41, and an intermediate portion of the cylindrical body 41 And a partition plate 44.

  The lower lid member 42, the upper lid member 43, and the partition plate 44 are provided with insertion holes 42a, 43a, 44a penetrating the front and back at the center thereof, respectively, and the three insertion holes 42a, 43a, 44a. In addition, since the radiant tube 22 is inserted, the lower lid member 42, the upper lid member 43, and the partition plate 44 are respectively penetrated by the radiant tube 22 as described above.

  Thus, in this partial oxidation reforming apparatus 40, the first reaction chamber 45a surrounded by the radiant tube 22, the cylinder 41, the lower lid member 42 and the partition plate 44, the radiant tube 22, the cylinder 41, the upper side A second reaction chamber 45 b surrounded by the lid member 43 and the partition plate 44 is provided. The first reaction chamber 45a and the second reaction chamber 45b are communicated with each other through a communication hole 44b formed in the partition plate 44.

  Further, a supply port 42b through which the reforming fuel gas and reforming air are supplied is drilled through the front and back at the edge of the lower lid member 42. The reforming fuel gas is supplied to the supply port 42b from the outside.

  In addition, a discharge port 41a through which the partially oxidized reformed fuel gas is discharged is drilled through the front and back at the other end portion of the cylindrical body 41. The discharge port 41a is appropriately connected via a pipe. And connected to the anode electrode layer side space 31 of the battery cell. Further, an insertion hole 41b penetrating the front and back is formed in the other end portion of the cylindrical body 41, and a thermocouple is appropriately inserted into the insertion hole 41b.

  A partition wall 46a is provided in the first reaction chamber 45a along the axial direction of the radiant tube 22, and the first reaction chamber 45a is blocked from communicating in the circumferential direction by the partition wall 46a. .

  Similarly, a partition wall 46b is provided in the second reaction chamber 45b along the axial direction of the radiant tube 22 so as to be collinear with the partition wall 46a. The communication state in the circumferential direction in the reaction chamber 45b is blocked.

  Further, the supply port 42b of the lower lid member 42, the communication hole 44b of the partition plate 44, and the discharge port 41a of the cylindrical body 41 are formed so as to be staggered, that is, staggered with the partition walls 46a and 46b interposed therebetween. Has been.

  The first reaction chamber 45a and the second reaction chamber 45b are filled with a catalyst for promoting the partial oxidation reforming reaction.

  In addition, as shown in FIGS. 1 and 2, the partial oxidation reforming apparatus 40 has one end exposed in the space 3 and the other end embedded in the bottom of the housing 2.

  Next, a power generation method in the fuel cell 1 having the above configuration will be described.

  In the fuel cell 1 of the present example, first, at the time of starting to activate the fuel cell 1, a preheating mode for raising the temperature of the battery cell to the power generation temperature (usually 700 to 800 ° C.) is executed, The partial oxidation reforming fuel gas containing the reducing gas is supplied from the partial oxidation reforming apparatus 40 to the anode electrode layer side space 31, and the oxidation of the anode electrode layer is prevented by this gas.

  The preheating mode is performed by supplying burner fuel gas and burner air to the burner 21 for combustion, supplying high-temperature combustion gas into the radiant tube 22, and heating the radiant tube 22 with the combustion gas. It is.

  That is, when the radiant tube 22 is heated, radiant heat is irradiated from the radiant tube 22 to the surroundings, and the steam reformer 10 and the battery stack 30 disposed on both sides of the radiant tube 22 are irradiated by the radiant heat. Each is heated directly and heated.

  Thus, in the fuel cell 1 of the present example, the steam reformer 10 and the battery stack 30 are directly heated by the radiant heat from the radiant tube 22, respectively. Can be shortened and energy efficiency can be increased.

  Further, since the radiant tube 22 is curved in a U-shape, the planar area occupied by the radiant tube 22 is wide. Therefore, the steam reformer 10 and the battery stack 30 are heated over a wide range. The battery cells in the steam reformer 10 and the battery stack 30 can be heated uniformly without unevenness.

  Further, the steam reforming apparatus 10 is configured such that the combustion gas from the radiant tube 22 is supplied to the combustion section 12 and is heated by using this combustion gas as a heat source. Be warmed.

  On the other hand, during the preheating mode, the partial oxidation reformer 40 is supplied with a mixed gas of reforming fuel gas and reforming air to the supply port 42b. The mixed gas supplied to the supply port 42 b moves from the supply port 42 b into the first reaction chamber 45 a and flows through the first reaction chamber 45 a so as to bypass the radiant tube 22, and then the partition plate 44. It moves into the second reaction chamber 45b through the communication hole 44b drilled in the same, and similarly flows around the radiant tube 22 in the second reaction chamber 45b. In this way, in the process of flowing through the first reaction chamber 45a and the second reaction chamber 45b, the reforming fuel gas is subjected to heat conduction and radiant heat from the radiant tube 22 and partially oxidized by the reforming air. It is reformed and discharged from the discharge port 41a as a partially oxidized reformed fuel gas containing a reducing gas (hydrogen gas). The partial oxidation reformed fuel gas discharged from the discharge port 41a is supplied to the anode electrode layer side space 31 as described above, and the oxidation of the anode electrode layer is prevented by the partial oxidation reformed fuel gas. FIG. 3 shows the flow of such a mixed gas. An arrow B in the figure indicates a process until the mixed gas supplied from the supply port 42b reaches the discharge port 41a.

  Thus, according to the partial oxidation reforming apparatus 40 of this example, the reforming fuel gas is reformed by the heat conduction and the radiant heat from the preheating radiant tube 22, Therefore, the energy efficiency of the entire fuel cell 1 can be increased, and the fuel cell 1 can be reduced in size and simplified.

  Further, the first reaction chamber 45a and the second reaction chamber 45b for performing the reforming reaction are cylindrical spaces in which the radiant tube 22 is arranged at the center, and therefore are supplied to the reaction chambers 45a and 45b. The mixed gas can receive heat conduction and radiant heat from the entire circumference of the radiant tube, which is efficiently reformed.

  Further, the supply port 42b and the discharge port 41a are formed at opposite ends of the reaction chamber composed of the first reaction chamber 45a and the second reaction chamber 45b, and the mixed gas is used for the first reaction chamber 45a and the first reaction chamber 45a. It is configured to take a flow path that detours in the two reaction chambers 45b, and is set so that the flow path of the mixed gas becomes longer, and the mixed gas flows from the first reaction chamber 45a to the second through the communication hole 44b. Since it is configured to flow into the reaction chamber 45b and be discharged to the outside from the discharge port 41a, the mixed gas can be retained in the first reaction chamber 45a and the second reaction chamber 45b for a sufficient time. The reforming fuel gas can be reformed more efficiently.

  When the temperature of the battery cell reaches the power generation temperature by executing the above preheating mode, the supply of the burner fuel gas and the burner air to the burner 21 is stopped, the preheating mode is terminated, and the partial oxidation reforming apparatus The supply of the reforming fuel gas and reforming air to 40 is stopped, and then the operation mode is shifted to the normal operation mode.

  That is, a mixed gas of water vapor and anode fuel gas generated by the water vapor generator 4 is supplied to the water vapor reformer 10, the anode fuel gas is steam reformed, and the reformed anode fuel gas is supplied to the anode. While supplying the electrode layer side space 31, the cathode air preheated by the heat exchanger 5 is supplied to the cathode electrode layer side space 32. Thereby, the battery cell starts power generation by an electrochemical reaction between the anode electrode layer and the cathode electrode layer.

  In order to steam reform the anode fuel gas, a temperature of 650 ° C. or higher, preferably 700 ° C. or higher is required. The steam reformer 10 is similar to the battery stack 30 in the preheating mode. The radiant heat irradiated from the radiant tube 22 is heated to a temperature similar to that of the battery stack 30 (about 700 ° C.). In the steam reforming apparatus 10, the temperature is sufficiently high until the end of the preheating mode. Efficient steam reforming is performed.

  Moreover, although heating of the battery stack 30 by the radiant tube burner 20 is stopped by ending the preheating mode, the steam reformer 10 performs combustion in the combustion unit 12 in order to obtain a heat source for steam reforming. Since the steam reforming apparatus 10 is maintained at a high temperature by this combustion, the radiant heat from the steam reforming apparatus 10 is irradiated to the battery stack 30 through the space 22a between the radiant tubes 22 curved in a U-shape. The stack 30 is maintained at a high temperature equal to or higher than the power generation temperature by the radiant heat.

  The exhaust gas (reacted steam reformed fuel gas, unreacted steam reformed fuel gas and cathode air) discharged from the anode electrode layer side space 31 and the cathode electrode layer side space 32 of the battery cell is steam. The fuel is supplied to the combustion unit 12 of the reformer 10 and burned in the combustion unit 12. By doing in this way, the energy efficiency of the fuel cell 1 can be improved.

  In the stop mode in which the normal operation is stopped, the supply of anode fuel gas, pure water, and cathode air is stopped, the supply of fuel to the combustion unit 12 of the steam reformer 10 is stopped, and the partial oxidation modification is performed. The reforming fuel gas and the reforming air are supplied to the quality device 40, and the partial oxidation reforming fuel gas containing the reducing gas is supplied to the anode electrode layer side space 31.

  As described above, the partial oxidation reforming apparatus 40 is exposed to the radiant heat from the steam reforming apparatus 10 in the normal operation mode because one end side thereof is exposed in the space 3. The temperature required for partial oxidation reforming (usually 600 ° C.) is maintained. Therefore, when the reforming fuel gas and the reforming air are supplied to the partial oxidation reforming device 40, the reforming fuel gas is partially oxidized and reformed, and the reformed partial oxidation reformed fuel gas is supplied to the anode electrode layer side. It is supplied to the space 31.

  As described above in detail, according to the fuel cell 1 according to the present embodiment, since the U-shaped radiant tube 22 is disposed between the steam reformer 10 and the battery stack 30, in the preheating mode. The battery cells inside the steam reformer 10 and the battery stack 30 can be efficiently heated and heated by the radiant heat irradiated from the radiant tube 22. Further, in the normal operation mode, the battery stack 30 can be heated by the radiant heat irradiated from the steam reformer 10 and the temperature can be maintained. Furthermore, since the heat conduction and radiant heat of the preheating radiant tube 22 are used as the heat source of the partial oxidation reforming apparatus 40, the energy efficiency of the entire fuel cell 1 can be increased, and the fuel cell 1 can be downsized. And simplification. Furthermore, in the partial oxidation reforming apparatus 40, the mixed gas stays in the first and second reaction chambers 45a and 45b for a long time, so that the reforming fuel gas is efficiently partially oxidized and reformed. be able to. Further, by exposing at least a part of the partial oxidation reforming apparatus 40 to the space 3 irradiated with radiant heat from the steam reforming apparatus 10, the partial oxidation reforming apparatus 40 always generates reformed gas in the normal operation mode. The temperature can be maintained, and a quick transition to the stop mode is possible.

  In this example, a part of the partial oxidation reforming apparatus 40 is partially exposed in the space 3. However, when the entire partial oxidation reforming apparatus 40 is exposed, the steam reforming is performed. This is because the radiant heat radiated from the apparatus 10 is blocked by the partial oxidation reforming apparatus 40, thereby preventing efficient heating of the battery stack 30. In this case, the partial oxidation reforming apparatus 40 is more than necessary. This is because the amount of heat that is heated by the heat is dissipated to the outside through another member connected to the partial oxidation reforming apparatus 40 from the outside, resulting in wasted heat energy.

  As mentioned above, although one Embodiment of this invention was described, the specific aspect which this invention can take is not limited to this at all.

  For example, examples of the shape of the radiant tube 22 include a spiral shape, a meandering shape, and a hook shape in addition to the U shape.

  Even in this case, the surface area of the radiant tube 22 can be increased, and the amount of radiant heat irradiated from the radiant tube 22 can be increased. Therefore, the steam reformer 10 and the battery stack 30 can be efficiently heated. In addition, the heating time can be shortened. In addition, since the planar area occupied by the radiant tube 22 is widened, the steam reforming apparatus 10 and the battery stack 30 can be heated in a wide range, and the battery cells in the steam reforming apparatus 10 and the battery stack 30 are uniform and uniform. The temperature can be increased.

  Furthermore, since the planar area occupied by the radiant tube 22 becomes wider by making the shape of the radiant tube 22 generally bent or curved substantially in an annular shape, the steam reforming apparatus 10 and the battery stack 30 are expanded. Can be heated in a wider range, and each battery cell in the steam reforming apparatus 10 and the battery stack 30 can be heated more uniformly and uniformly.

  Moreover, in this example, although the 1st and 2nd reaction chamber 45a, 45b was formed in the partial oxidation reforming apparatus 40, it was not restricted to this.

  For example, the space surrounded by the radiant tube 22, the cylinder 41, the lower lid member 42, and the upper lid member 43 is divided into a space on the supply port 42b side and a space on the discharge port 41a side. It is good also as a structure which provided the board and perforated | pierced the communicating hole which connects two space to this partition plate. The partition plate only needs to bisect the space on the supply port 42b side and the space on the discharge port 41a side.

  In this way, the mixed gas of the reforming fuel gas and the reforming air supplied from the supply port 42b circulates in the space on the supply port 42b side, passes through the communication hole, and is on the discharge port 41a side. Since it moves to the space and is discharged from the discharge port 41a, the residence time of the mixed gas in the reaction chamber can be increased, and the reforming fuel gas can be efficiently reformed by the reforming air. .

  Further, a partition plate 44 is further provided to form three or more reaction chambers, and a mixed gas of the reforming fuel gas and the reforming air supplied from the supply port 42b is supplied to the three or more reaction chambers. It may be discharged from the discharge port 41a via Thereby, the residence time of the mixed gas in the reaction chamber can be made longer, and the reforming fuel gas can be reformed more efficiently by the reforming air.

DESCRIPTION OF SYMBOLS 1 Fuel cell 2 Housing | casing 3 Space 4 Steam generator 5 Heat exchanger 10 Steam reformer 20 Radiant tube burner 21 Burner 22 Radiant tube 22a Space 30 Battery stack 31 Anode electrode layer side space 32 Cathode electrode layer side space 40 Partial oxidation Reformer 41 Cylinder 41a Discharge port 42 Lower lid member 42b Supply port 43 Upper lid member 44 Partition plate 44b Communication hole 45a First reaction chamber 45b Second reaction chamber 46a, 46b Partition wall

Claims (10)

A steam reforming device comprising a combustion section, and steam reforming the fuel gas by the combustion heat generated in the combustion section;
A battery stack including a battery cell having a cathode and an anode, and generating power by an electrochemical reaction between an oxidizing gas supplied to the cathode and a reformed fuel gas supplied from the steam reformer supplied to the anode; In a fuel cell,
A fuel cell characterized in that a radiant tube burner comprising a burner for burning fuel gas and a radiant tube connected to the burner is disposed between the cell stack and the steam reformer. .   2. The fuel cell according to claim 1, wherein at least a part of the radiant tube is bent or curved in a spiral shape, a meandering shape, a saddle shape, or a U shape.   2. The fuel cell according to claim 1, wherein the radiant tube is bent or curved in a substantially annular shape as a whole.   2. The radiant tube is configured such that an exhaust side of the radiant tube is connected to a combustion part of the steam reformer, and combustion gas of the radiant tube burner is supplied to the combustion part. 4. The fuel cell according to any one of items 3 to 3.   5. The fuel cell according to claim 1, wherein a partial oxidation reforming device for partially oxidizing and reforming a fuel gas and supplying the gas to an anode of the battery cell is attached to the radiant tube. The partial oxidation reformer is
A cylindrical body spaced around the radial direction of the radiant tube and provided around the axis of the radiant tube;
The radiant tube comprises two lid members respectively fixed to both ends of the cylindrical body in a state of penetrating the front and back.
A supply port through which the fuel gas is supplied to the reaction chamber surrounded by the radiant tube, the cylinder, and the two cover members is formed in one end of the cylinder or the lid member fixed to the one end. And
The lid member fixed to the other end of the cylindrical body or the other end is provided with an exhaust port through which fuel gas partially oxidized and reformed in the reaction chamber is discharged. Item 6. The fuel cell according to Item 5. In the partial oxidation reforming apparatus, the reaction chamber is divided into two spaces by a partition plate disposed in the reaction chamber, the supply port is connected to one space, and the other space is connected to the other space. Is connected to the outlet,
7. The fuel cell according to claim 6, wherein the partition plate is provided with a communication hole that allows the space on the supply port side and the space on the discharge port side to communicate with each other. In the partial oxidation reforming apparatus, the reaction chamber is divided into two or more annular spaces along the axial direction of the radiant tube by one or more partition plates disposed in the reaction chamber. In addition to being divided, in the axial direction, the supply port is connected to one of the spaces at both ends thereof, and the discharge port is connected to the other.
The fuel cell according to claim 6, wherein the partition plate is provided with a communication hole that allows adjacent spaces to communicate with each other. Each annular space in the reaction chamber is provided with a partition wall that blocks the circumferential communication state,
The partition walls are arranged in a line along the axial direction of the radiant tube,
The supply port, the communication hole, and the discharge port are disposed at positions close to the partition wall, and are sequentially disposed at staggered positions along the axial direction of the radiant tube across the partition wall. The fuel cell according to claim 8, wherein Surrounded by a heat insulating member, it has a space thermally insulated from the outside,
In the space, the steam reformer, the battery stack and the radiant tube are disposed,
10. The fuel cell according to claim 5, wherein one end of the partial oxidation reforming apparatus is exposed in the space and the other end is disposed outside the space.

Images