JP6264710B2 - Fuel cell - Google Patents

Description

  The present invention relates to an improvement in a fuel cell having a combustion region in which a fuel gas and an oxidizing gas are mixed and burned after being supplied to a single cell and used for power generation.

  An example of this type of fuel cell is described in Patent Document 1 under the name of a fuel cell assembly. A fuel cell described in Patent Literature 1 includes an inner electrode, a solid electrolyte, and an outer electrode, a fuel battery cell in which an internal gas channel is formed, an internal gas supply unit that supplies gas to the internal gas channel, a fuel An external gas supply means for supplying gas to the outside of the battery cell is provided, and the internal gas and the external gas are mixed in the upper space of the end surface on the outlet side of the fuel cell. That is, the upper space on the outlet side end face of the fuel cell is the combustion region.

  In the fuel cell assembly, the internal gas is a fuel gas and the external gas is an oxidant gas. In the fuel cell, an annular member is provided on the outlet side of the fuel cell to rectify the gas, and in the upper space, the fuel gas and the oxidant gas after being used for power generation are mixed and burned. ing.

JP-A-2005-346988

  However, in the conventional fuel cell as described above, the internal gas (fuel gas) passing through the inside of the fuel cell and the external gas (oxidizing gas) flowing outside the fuel cell are mixed and burned. Therefore, one large flame is formed by diffusion combustion with respect to one fuel battery cell, and it is difficult to make the temperature distribution in the combustion region uniform.

  Further, in the above fuel cell, the combustion region must be arranged only in the upper space of the fuel cell, so this restriction on the arrangement affects the layout when considering, for example, an in-vehicle fuel cell. As described above, in the conventional fuel cell, it is difficult to make the temperature distribution in the combustion region uniform, and the layout of the configuration including the combustion region is limited, and it has been a problem to solve these problems.

  The present invention has been made paying attention to the above-described conventional problems, and provides a fuel cell capable of making the temperature distribution in the combustion region uniform and increasing the degree of freedom of the layout including the combustion region. It is intended to provide.

A fuel cell according to the present invention is a fuel cell having a combustion region in which fuel gas and oxidant gas are mixed and burned after being supplied to a single cell and used for power generation, and the electrolyte layer is sandwiched between the fuel electrode layer and the air electrode layer. Thus, a flat single cell and wave-shaped separators that are reversed upside down are alternately stacked. The fuel cell is between the single cells that are adjacent in the stacking direction, one of the oxidizing gas channel of the fuel gas flow path and the other unit cell for a single cell is divided by the separator, one of the separator waveform recess in the plane, along with the a fuel gas flow path, the waveform recess in the other surface of said separator, said a oxidizing gas passage, the end portion of the separator, the fuel gas channel and the oxidizing the fuel gas outlet and the oxidizing gas outlet opening the gas passage into the combustion area are provided. Then, at least an end portion of said separator comprises means for forming a plurality of diffusion surfaces fuel gas and the oxidizing gas flowing out from the fuel gas outlet and the oxidizing gas outlet are in contact with each other, the end portion of the separator, the The fuel gas outlets and the oxidizing gas outlets are alternately arranged according to the wave shape of the separator, and the means for forming a plurality of diffusion surfaces is constituted by the wave shape of the separator . .

  In the fuel cell according to the present invention, a plurality of diffusion surfaces in which the fuel gas and the oxidant gas flowing out from the fuel gas outlet and the oxidizing gas outlet contact each other are formed at the end of the separator. A plurality of flames, which are light emission phenomena due to the oxidation reaction, are formed. Thereby, in the fuel cell, the temperature distribution in the combustion region becomes uniform, and the combustion temperature can be reduced. In addition, the fuel cell described above forms a plurality of diffusion surfaces to form a small flame substantially similar to premixed combustion or premixed combustion, and the flame rises in the vertical direction by convection due to a rise in combustion temperature. Can be reduced as much as possible, so that it is possible to arrange the combustion region on the upper part or the side part of the single cell.

Since the fuel cell according to the present invention employs the above-described configuration , a large number of small flames that are substantially premixed combustion or premixed combustion are formed in the combustion region, and the temperature distribution in the combustion region can be made uniform. In addition, the degree of freedom of the layout including the combustion region can be increased. Further, the fuel cell can also uniformize the thermal stress applied to the single cell by making the temperature distribution in the combustion region uniform, thereby preventing damage to the constituent members of the single cell.

The perspective view (A) explaining 1st Embodiment of the fuel cell concerning this invention, the top view (B) of the principal part with an enlarged view, the top view (C) which shows arrangement | positioning of a single cell and a separator, and a manifold part It is a horizontal sectional view (D) in a channel center. It is explanatory drawing (A1) which shows premix combustion, graph (A2) which shows temperature distribution of premix combustion, explanatory drawing (B1) which shows diffusion combustion, and graph (B2) which shows temperature distribution of diffusion combustion. FIG. 1 is a plan view (A1) of the main part of the fuel cell, an explanatory diagram (A2) showing the combustion state, a plan view (B1) of the main part of a conventional fuel cell as a comparative example, and an explanation showing the combustion state. It is a graph (C) which shows figure (B2) and both temperature distribution. FIG. 4 is a perspective view (A), a plan view (B), and a horizontal sectional view (C) based on the line AA in FIG. B, illustrating a second embodiment of the fuel cell according to the present invention. FIG. 5 is a plan view (A) of a single cell in the fuel cell shown in FIG. 4 and a cross-sectional view (B) based on the line AA in FIG. It is a top view of the principal part which shows 3rd Embodiment of the fuel cell concerning this invention. It is the top view (A) of the principal part which shows 4th Embodiment of the fuel cell concerning this invention, and the graph (B) which shows temperature distribution. It is the top view (A) and perspective view (B) which show 5th Embodiment of the fuel cell concerning this invention. It is the perspective view (A) which shows 6th Embodiment of the fuel cell concerning this invention, and the graph (B) which shows temperature distribution. It is a perspective view which shows 7th Embodiment of the fuel cell concerning this invention. It is the perspective view (A) which shows 8th Embodiment of the fuel cell concerning this invention, and the top view (B) which shows the other example of a separator.

<First Embodiment>
A fuel cell FC1 shown in FIG. 1 (A) has a combustion region Q in which fuel gas and oxidant gas are mixed and burned after being supplied to the single cell C1 and used for power generation, and includes a single cell C1 and a separator S1. It has the structure which laminated | stacked alternately.

  In the illustrated fuel cell FC1, a plurality of single cells C1 and separators S1 are alternately stacked to form a stacked body (fuel cell stack) FS, and the stacking direction is set horizontally on a manifold M having gas flow paths. The laminated body FS is arranged in the posture as described above. The fuel cell FC1 surrounds the stacked body FS with a casing B provided on the manifold M, and the upper space of the stacked body FS is set as a combustion region Q inside the casing B. The casing B is provided with an exhaust part D for combustion gas at the top.

  The single cell C1 has a rectangular flat plate shape, and has a structure in which the electrolyte layer 1 is sandwiched between a fuel electrode layer (anode) 2 and an air electrode layer (cathode) 3 as shown in FIG. In the illustrated example, the fuel electrode layer 2 has a porous metal layer 4 as a support. For each of these layers 1 to 4, for example, a known material applicable to a solid oxide fuel cell can be used.

  The separator S1 divides one unit cell fuel gas channel G1 and the other unit cell oxidizing gas channel G2 between the unit cells C1 adjacent to each other in the stacking direction. Further, the separator S1 is provided with a fuel gas outlet E1 and an oxidizing gas outlet E2 that open the fuel gas passage G1 and the oxidizing gas passage G2 to the combustion region Q at the end thereof. Furthermore, the separator S1 has means for forming a plurality of diffusion surfaces at the end portions where the fuel gas and the oxidizing gas flowing out from the fuel gas outlet E1 and the oxidizing gas outlet E2 come into contact with each other. The means for forming the plurality of diffusion surfaces is formed by bending or curving at least the end of the separator S1, and in this embodiment, the one formed by bending is illustrated.

  The fuel gas (anode gas) contains hydrocarbon, carbon monoxide, hydrogen and the like. The oxidizing gas (cathode gas) is an oxygen gas or an oxygen-containing gas, and is generally air. Since these gases are supplied to a single cell and contribute to power generation, those after use of power generation are strictly fuel exhaust gas containing water vapor and carbon dioxide in addition to hydrocarbons, carbon monoxide, hydrogen, and the like, and Oxidized exhaust gas containing oxygen.

  Separator S1 of this embodiment is a rectangular plate member made of a metal such as stainless steel, and has a wave shape that is generally reversed with front and back surfaces having a trapezoidal cross section, and has a plurality of wave shapes at its end. A means for forming the diffusion surface is configured. The separator S1 can be easily formed by, for example, pressing. Further, the separator S1 is arranged in a direction in which the wave shape appears in the horizontal cross section, the fuel gas flow path G1 is formed by the corrugated concave portion on one surface, and the oxidizing gas flow path G2 is formed by the corrugated concave portion on the other surface. Yes.

  As shown in FIG. 1C, the separator S1 has a fuel gas outlet E1 indicated by a black circle in FIG. 1C and an oxidizing gas outlet E2 indicated by a white circle in FIG. Are arranged alternately. Note that black circles and white circles in FIG. 1C indicate the arrangement of the outlets E1 and E2, and the shapes of the outlets E1 and E2 are trapezoids that are uneven shapes of the separator S1.

  As shown in FIG. 1D, the manifold M includes a planar rectangular base 5 and fuel gas and oxidizing gas introduction parts 6 </ b> A and 6 </ b> B arranged on both sides of one end of the base 5. The base 5 has linear main flow paths 7A and 7B communicating with the introduction portions 6A and 6B on both sides of the base 5 in parallel with each other, and the main flow paths 7A and 7B extend toward the other side. A plurality of branch channels 8A and 8B are provided. In each branch channel 8A, 8B, the fuel gas and the oxidizing gas are alternately arranged in parallel with each other at a predetermined interval.

  With respect to the manifold M, the stacked body FS is arranged in such a direction that the stacking direction is the arrangement direction of the branch channels 8A and 8B (vertical direction in FIGS. 1C and D). The stacked body FS and the manifold M communicate the fuel gas flow path G1 and the fuel gas branch flow path 8A at the respective positions of the single cell C1, and the oxidizing gas flow path G2 and the oxidizing gas branch. The flow path 8B is communicated. Further, fuel gas and oxidant gas supply means (not shown) are connected to the introduction portions 6A and 6B of the manifold M, respectively.

  In consideration of application as an in-vehicle power source, it is important to make the fuel cell FC1 as small as possible so that the temperature can be rapidly raised to an operating state. One countermeasure is to reduce the thickness of the separator S1. For example, it is effective to set the thickness of the separator S1 to 0.3 mm or less. Such a thin separator S1 may cause thermal deformation such as distortion due to a high temperature in the vicinity of the combustion region Q. However, by making the wave shape as described above, the thermal deformation is suppressed and power generation durability is improved. Can be improved.

  The fuel cell FC1 having the above-described configuration is configured such that a fuel gas (indicated by a dotted line arrow in FIG. 1) and an oxidizing gas (indicated by a solid line arrow in FIG. 1) flow through the manifold M in the stacked body FS. The gas is introduced into the channel G1 and the oxidizing gas channel G2, and these gases are supplied to the fuel electrode layer 2 and the air electrode layer 3 of each unit cell C1, respectively, and power is generated by an electrochemical reaction. Then, the fuel cell FC1 causes the fuel gas (fuel exhaust gas) and the oxidizing gas (oxidized exhaust gas) after use of power generation to flow upward from the fuel gas outlet G1 and the oxidizing gas outlet G2, and both are mixed and burned in the fuel region Q. . The combustion gas is discharged from the exhaust part D of the casing B.

  At this time, the fuel cell FC1 forms, at least at the end of the separator S1, a plurality of diffusion surfaces in which the fuel gas and the oxidizing gas that have flowed out from the fuel gas outlet G1 and the oxidizing gas outlet G2 come into contact with each other due to the bent wave shape. Therefore, in the combustion region Q, a plurality of flames that are light emission phenomena due to oxidation reactions on a plurality of diffusion surfaces are formed. In other words, the fuel cell FC1 has a plurality of diffusion surfaces as described above, thereby providing many opportunities for collision of fuel gas and oxidant gas molecules, and preventing substantial diffusion combustion. Combustion close to mixed combustion or premixed combustion.

  Here, premixed combustion and diffusion combustion will be described with reference to FIG. As shown in FIG. 2 (A1), the premixed combustion is a homogeneous combustion because the fuel gas and the oxidizing gas are mixed in advance. In addition, since the premixed combustion also reacts inside the flame, the temperature distribution is slow at any of the lower part (A), the central part (B), and the upper part (C) of the flame as shown in FIG. 2 (A2). It is difficult for the flame to be affected by the direction of gravity.

  On the other hand, as shown in FIG. 2 (B1), diffusion combustion is combustion in a region where the diffused fuel molecules collide with oxygen molecules at the interface where the internal fuel gas and the external oxidizing gas contact. Become. For this reason, in diffusion combustion, it reacts on the diffusion surface to increase the temperature, and as shown in FIG. 2 (B2), the higher the temperature is due to buoyancy and convection (A → C), the higher the temperature rises.

  That is, in the fuel cell FC1 shown in FIG. 3 (A1), the fuel gas outlet E1 and the oxidizing gas outlet E2 are alternately arranged by the wave-shaped separator S1, so that the diffusion surface where the fuel gas and the oxidizing gas contact each other Are formed to perform premixed combustion or combustion close to premixed combustion, and a large number of low-temperature small flames are formed above the single cell C1 as shown in FIG. 3 (A2).

  On the other hand, in the conventional fuel cell PC shown in FIG. 3 (B1), the fuel gas channel G1 and the oxidizing gas channel G2 are partitioned by the flat separator S, so that the fuel cell FC1 of the present invention. In comparison with FIG. 3, a single diffusion surface is formed only in the width direction of the single cell C to perform diffusion combustion, and a large high-temperature flame is formed on the upper portion of the single cell C as shown in FIG.

  Therefore, in the fuel cell FC1, the temperature distribution of the diffusion combustion shown by the dotted line in FIG. 3C is low and the temperature distribution is greatly uniformed as shown by the solid line in the figure. It will be.

  In the fuel cell FC1 of the above embodiment, since smaller flames are formed on the plurality of diffusion surfaces, it is possible to reduce as much as possible that the flames rise in the vertical direction due to convection due to a rise in combustion temperature. Thereby, it becomes possible to make the combustion region Q small, or to provide the combustion region on the side portion of the single cell C1 as in the second embodiment described later.

  In this way, the fuel cell FC1 described above can make the temperature distribution in the combustion region Q uniform and increase the degree of freedom of the layout including the combustion region Q. In addition, the fuel cell FC1 can uniformize the thermal stress applied to the single cell C1 by making the temperature distribution in the combustion region Q uniform, thereby preventing damage to the constituent members of the single cell C1.

  Furthermore, since the fuel cell FC1 can reduce the combustion region Q, in the configuration having the combustion region Q above the single cell C1 as in the above embodiment, specifically, the height of the casing B It is possible to reduce the size and reduce the size and weight of the fuel cell FC1. In addition, since the fuel cell FC1 performs combustion substantially similar to premixed combustion or premixed combustion, generation of soot can be suppressed.

  Further, since the fuel cell FC1 employs the wave-shaped separator S1, means for forming a plurality of diffusion surfaces where the fuel gas and the oxidizing gas are in contact with each other using the separator S1 that can be easily mass-produced by pressing. It can be obtained, and a reduction in manufacturing cost can also be realized.

  Hereinafter, the second to eighth embodiments will be described with reference to FIGS. In the following embodiments, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

Second Embodiment
A fuel cell FC2 shown in FIG. 4 (A) has a disk-like single cell C2 shown in FIG. 5 and a disk-like separator S2 alternately stacked, and a stack FS having a plane shown in FIG. 5 (B). The stacked body FS is arranged on the manifold M in a posture in which the stacking direction is set to the vertical direction, and the stacked body FS is surrounded by the casing B.

  A disc-shaped gas flow path member 10 is disposed at the center of the single cell C2 and the separator S2. The gas flow path member 10 includes an oxidizing gas introduction hole 10B arranged at the center thereof, and four fuel gas introduction holes 10A arranged at intervals of 90 ° around the oxidizing gas introduction port 10A. Each of the oxidizing gas introduction hole 10B and each fuel gas introduction hole 10A has a flow passage (not shown) that communicates in the radial direction and opens to the outer peripheral portion of the gas passage member 10.

  In the state where the gas flow path member 10 is stacked in multiple stages together with the single cell C2 and the separator S2, each of the fuel gas introduction hole 10A and the oxidation gas introduction hole 10B communicates with each other, as shown in FIG. The fuel gas introduction path F1 and the oxidizing gas introduction path F2 that are continuous in the stacking direction are formed.

  The separator S2 has a curved wave shape composed of trapezoidal irregularities, and as shown in FIG. 5 (A), the concave and convex portions are substantially radially and in the same circumferential direction (in the clockwise direction in the figure). ) In a curved state. As shown in FIG. 5B, the separator S2 includes a fuel gas channel G1 for one unit cell and an oxidizing gas channel for the other unit cell between the unit cells C1 adjacent in the stacking direction. G2 is partitioned.

  That is, in the separator S2, the fuel gas flow path G1 is formed by the corrugated concave portion on one surface, and the oxidizing gas flow path G2 is formed by the corrugated concave portion on the other surface. The separator S1 has a bent wave shape in which fuel gas outlets E1 and oxidizing gas outlets E2 are alternately arranged in the circumferential direction at the end on the outer peripheral side.

  Thereby, separator S2 is provided with a means for forming a plurality of diffusion surfaces where fuel gas and oxidant gas which flowed out from fuel gas outlet E1 and oxidant gas outlet E2 contact each other in the peripheral edge part. Therefore, in this embodiment, a combustion region Q in which the fuel gas and the oxidizing gas are mixed and burned is formed on the outer peripheral side which is the side portion of the single cell C2 and the separator S.

  As shown in FIGS. 4B and 4C, the manifold M includes a rectangular base 5, fuel gas and oxidizing gas introduction parts 6 </ b> A and 6 </ b> B disposed on both sides of one end of the base 5, and other parts of the base 5. And an exhaust part D disposed at the end. The base 5 has flow paths 7A, 7B, 7C communicating with the introduction parts 6A, 6B and the exhaust part D therein.

  The manifold M is connected to the lower end portion of the fuel gas introduction passage F1 and the fuel gas passage 7A in a state where the laminated body FS is installed on the base 5, and the lower end portion of the oxidation gas introduction passage F2 is oxidized. The gas flow path 7B communicates. In addition, an annular space including the combustion region Q is formed between the stacked body FS and the casing B, and in the manifold M, the lower end portion of the annular space communicates with the exhaust gas flow path 7C.

  Similar to the first embodiment, the fuel cell FC2 introduces the fuel gas and the oxidizing gas into the fuel gas channel G1 and the oxidizing gas channel G2 of the stacked body FS via the manifold M, and these gases. Is supplied to each single cell C2 to generate electricity by an electrochemical reaction. Then, the fuel cell FC1 causes the fuel gas and the oxidizing gas after use of power generation to flow out from the fuel gas outlet E1 and the oxidizing gas outlet E2 in the lateral direction of the stacked body FS, and both are mixed and burned in the fuel region Q. The combustion gas is discharged from the exhaust part D of the manifold M.

  The fuel cell FC2 has a wave shape in which the outer peripheral end of the separator S2 is bent to form a plurality of diffusion surfaces in which the fuel gas and the oxidizing gas are in contact with each other. Alternatively, combustion close to premixed combustion is performed, and a plurality of small flames are formed at low temperatures that are not easily affected by the direction of gravity. Therefore, the combustion region Q is disposed on the side portion of the single cell C2.

  In this manner, even in the fuel cell FC2, the temperature distribution in the combustion region Q can be made uniform, and the degree of freedom of the layout including the combustion region Q can be increased. The fuel cell FC2 also uniformizes the temperature distribution in the combustion region Q, thereby uniformizing the thermal stress applied to the single cell C1, thereby preventing damage to the components of the single cell C1. Realizes weight reduction, suppression of wrinkles, and reduction of manufacturing costs.

<Third Embodiment>
The fuel cell partially shown in FIG. 6 has the same basic configuration as that of the first embodiment, the single cell C1 has a flat plate shape, the separator S1 has a curved wave shape, and is adjacent to the stacking direction. S1s are arranged so as to be shifted from each other by a half pitch of the corrugated irregularities. That is, in the adjacent separators S1, the corrugated recesses of one separator S1 and the corrugated recesses of the other separator S1 face each other with the single cell C1 in between. As another expression, one separator S1 fuel gas channel G1 facing the fuel electrode layer 2 and the other separator S1 oxidizing gas channel G2 facing the air electrode layer 3 sandwich the single cell C1. Are opposed to each other.

  Even in the fuel cell of the above embodiment, the same effects as those of the previous embodiments can be obtained. Further, the separators S1 adjacent to each other in the stacking direction are shifted from each other by a half pitch of the corrugated irregularities. Since it arrange | positions, the damage prevention of the single cell C1 and the oxidation of the fuel electrode layer 2 and the reduction | restoration of the air electrode layer 3 can be suppressed if the porous metal layer 4 is included.

  In other words, as described above, the fuel cell needs to have a very small heat capacity of the single cell C1 in consideration of rapid start-up, and the single cell C1 needs to be very thin. On the other hand, when the separator S1 is wave-shaped and is brought into close contact with the single cell C1, it is necessary to press the separator S1 against the single cell C1 with an appropriate load.

  Therefore, in this embodiment, the separators S1 adjacent to each other in the stacking direction are arranged so as to be shifted from each other by a half pitch of the corrugated irregularities, and the position of the corrugated convex portion of one separator S1 and the waveform of the other separator S1. The unit cell C1 is sandwiched between the corrugated convex portions by matching the positions of the convex portions. Thereby, in the fuel cell, when the thin single cell C1 is adopted, excessive mechanical stress is not generated in the single cell C1, and damage to the single cell C1 is prevented. In other words, the thin single cell C1 can be adopted, and it can contribute to the reduction of the heat capacity of the single cell C1 and the rapid start-up of the fuel cell.

  In the fuel cell, the separators S1 adjacent to each other in the stacking direction are arranged so as to be shifted from each other by a half pitch of the corrugated irregularities, so that different types of gas circulate in the two corrugated concaves facing each other across the single cell C1. . That is, fuel gas flows through one of the corrugated recesses facing each other, and oxidizing gas flows through the other corrugated recess. This prevents the amount of fuel gas or oxidizing gas discharged per unit volume from being biased at the ends of the unit cell C1 and the separator S1, thereby suppressing oxidation of the fuel electrode layer 2 and reduction of the air electrode layer 3. To do.

  At the end portion (end portion on the gas outlet side) of the single cell C1, for example, when the amount of fuel gas per unit volume increases, the discharged fuel is not oxidized but diffused into the air electrode layer 3, and the air There is a possibility of reducing and degrading the pole material. Further, when the amount of the oxidizing gas per unit volume increases, the porous metal layer 4 as the support and the fuel electrode layer 2 may be oxidized and may be damaged due to oxidative expansion. The fuel cell eliminates such a problem caused by the uneven gas amount.

<Fourth embodiment>
The fuel cell, part of which is shown in FIG. 7A, has the same basic configuration as that of the first embodiment, and the single cell C1 has a flat plate shape and a wave shape in which the separator S1 is bent. The length b corresponding to one pitch of the corrugated irregularities is equal to or smaller than the interval dimension a (b ≦ a) between the single cells C1 adjacent in the stacking direction.

  Even in the above fuel cell, the same effects as those of the previous embodiments can be obtained, and the length b of one pitch of the corrugated unevenness of the separator S1 is set to be equal to or smaller than the interval dimension a between the single cells C1. Therefore, more fuel gas outlets G1 and oxidizing gas outlets G2 are arranged. In such a fuel cell, as shown in the upper side of FIG. 7B, more diffusion surfaces where the fuel gas and the oxidizing gas are in contact with each other are formed, and more small flames are generated due to premixed combustion.

  As a result, the fuel cell has a lower combustion temperature (solid line) in the combustion region Q than the combustion temperature (dotted line) of the battery shown in the lower side of FIG. Further uniform temperature can be achieved.

<Fifth Embodiment>
A fuel cell FC1 partially shown in FIG. 8A has the same basic configuration as that of the first embodiment, the single cell C1 has a flat plate shape, has a wave shape in which the separator S1 is bent, and the separator S1. Are provided with outlet members 20 having discharge holes 20A and 20B corresponding to the respective fuel gas outlets (reference numeral E1 in FIG. 1) and the respective oxidizing gas outlets (reference numeral E2 in FIG. 1).

  That is, the discharge holes 20A and 20B are alternately arranged for the fuel gas and the oxidizing gas corresponding to the alternately arranged fuel gas outlets and the oxidizing gas outlets. In the outlet member 20, the interval c between the discharge holes 20A and 20B is equal to or less than the interval a (c ≦ a) between the single cells C1 adjacent in the stacking direction. In this case, it is more preferable that the separator S1 has a length b corresponding to one pitch of the corrugated unevenness equal to or smaller than the interval dimension a between the single cells C1 as in the fourth embodiment.

  Even in the fuel cell FC1, the same effects as those of the previous embodiments can be obtained, and the end face of the single cell C1 can be protected by adopting the outlet member 20. Further, in the fuel cell FC1, since the interval c between the discharge holes 20A and 20B is set to be equal to or less than the interval a between the single cells C1, more diffusion surfaces where the fuel gas and the oxidizing gas are in contact with each other are formed and premixed combustion is performed. More small flames can be generated, and the combustion temperature in the combustion region Q can be further reduced and the combustion temperature can be made more uniform.

<Sixth Embodiment>
The fuel cell FC1 partially shown in FIG. 9A has the same basic configuration as that of the first embodiment, the single cell C1 has a flat plate shape, has a wave shape in which the separator S1 is bent, and the separator S1. The pitch P2 in the side region is larger than the pitch P1 in the central region.

  Even in the fuel cell FC1, the same effects as those of the previous embodiments can be obtained, and the temperature distribution in the combustion region Q can be further uniformized. That is, in the fuel cell FC1, the temperature at the center becomes the highest due to the influence of heat dissipation. That is, when the pitch of the corrugated unevenness of the separator S1 is the same as a whole, as shown by a dotted line in FIG. 9B, the temperature of the side region is lower than the central region.

  Therefore, in the fuel cell FC1, by making the pitch P2 in the side region larger than the pitch P1 of the corrugated irregularities in the central region, a small flame is formed in the central region by premixed combustion, and the same combustion is generated in the side region. To form a big flame. Thereby, as shown by a solid line in FIG. 9B, the fuel cell FC1 raises the temperature of the side region with respect to the central region, thereby realizing further uniformization of the entire temperature distribution.

<Seventh embodiment>
A fuel cell FC1 partially shown in FIG. 10 has the same basic configuration as that of the first embodiment, the single cell C1 has a flat plate shape, and has a wave shape in which the separator S1 is bent. The pitch P2 in the side region is larger than the pitch P1 in the central region. The fuel cell FC1 also has a pitch P2 in the side region larger than the pitch P1 in the central region in the stacking direction. That is, a plurality of separators S1 having different corrugated pitches are used.

  Even in the fuel cell FC1, the same effects as those of the previous embodiments can be obtained, and in the combustion region Q, not only the temperature distribution in the width direction of the separator S1, but also the temperature distribution in the stacking direction is uniform. And uniformization of the overall temperature distribution in the stacked body FS is realized.

<Eighth Embodiment>
A fuel cell FC1 partially shown in FIG. 11A has the same basic configuration as that of the first embodiment, the single cell C1 has a flat plate shape, and has a wave shape in which the separator S1 is bent. The through hole H for mixing the fuel gas just before the outflow and the oxidizing gas is provided in the vicinity of the end of the.

  Even in the fuel cell FC1, the same effects as those of the previous embodiments can be obtained, and the through hole H is provided near the end of the separator S1, so that the fuel gas flow path G1 and the oxidizing gas flow are provided. The fuel gas and the oxidizing gas are mixed at the end of the path G2. Thereby, in the fuel cell FC1, premixed combustion is reliably performed, and it is possible to achieve further uniform temperature distribution and suppression of soot formation.

  In each of the above embodiments, the bent wave-shaped separators S1 and S2 made of trapezoidal irregularities are exemplified as the separator provided with means for forming a plurality of diffusion surfaces at the end, but FIG. A bent wave-shaped separator S3 having quadrangular irregularities as shown in FIG. 5 or a curved wave-shaped separator (sinusoidal) can be used, and the shape is not particularly limited.

  In each of the above embodiments, the wave-shaped separator is exemplified. However, the separator used in the fuel cell of the present invention has the fuel gas and the oxidizing gas flowing out from the fuel gas outlet and the oxidizing gas outlet at least at the ends. Any means provided with means for forming a plurality of diffusion surfaces in contact with each other may be used, and those having different cross-sections in the gas flow direction may be employed.

  And the structure of the fuel cell of this invention is not limited to said each embodiment, The detail of a structure can be suitably changed in the range which does not deviate from the summary of this invention.

C, C2 Single cell E1 Fuel gas outlet E2 Oxidizing gas outlet FC1, FC2 Fuel cell G1 Fuel gas passage G2 Oxidation gas passage H Through-hole Q Combustion region S1, S2 Separator 1 Electrolyte layer 2 Fuel electrode layer 3 Air electrode layer 20A , 20B Discharge hole 20 Outlet member

Claims (7)

A fuel cell having a combustion region in which fuel gas and oxidant gas are mixed and burned after being supplied to a single cell and used for power generation,
It has a structure in which a flat single cell formed by sandwiching an electrolyte layer between a fuel electrode layer and an air electrode layer, and wave-shaped separators that are reversed upside down, are laminated alternately,
In between the single cells that are adjacent in the stacking direction, to partition one and an oxidizing gas flow path for the fuel gas flow path and the other unit cell for single cell in the separator,
The corrugated recess on one surface of the separator is the fuel gas flow path, and the corrugated recess on the other surface of the separator is the oxidizing gas flow path,
The end portion of the separator is provided with a fuel gas outlet and an oxidizing gas outlet and opens the fuel gas passage and the oxidizing gas flow path into the combustion area.
At least an end portion of said separator comprises means for forming a plurality of diffusion surfaces fuel gas and the oxidizing gas flowing out from the fuel gas outlet and the oxidizing gas outlet are in contact with each other,
The fuel gas outlets and the oxidizing gas outlets are alternately arranged at the end of the separator according to the corrugated shape of the separator, and means for forming a plurality of diffusion surfaces is constituted by the corrugated shape of the separator A fuel cell characterized by being made . 2. The fuel cell according to claim 1 , wherein separators adjacent in the stacking direction are arranged so as to be shifted from each other by a half pitch of the corrugated irregularities. 3. The fuel cell according to claim 1, wherein a length of one pitch of the corrugated unevenness of the separator is equal to or smaller than a distance between adjacent single cells in the stacking direction. The fuel cell according to any one of claims 1 to 3 , wherein an outlet member having discharge holes respectively corresponding to the respective fuel gas outlets and the respective oxidizing gas outlets is provided at an end of the separator. The fuel cell according to claim 4 , wherein the interval between the discharge holes in the outlet member is equal to or less than the interval between the single cells adjacent in the stacking direction. The fuel cell according to any one of claims 1 to 5 , wherein the pitch of the corrugated irregularities of the separator is larger in the side region than in the central region. The fuel cell according to any one of claims 1 to 6 , wherein a through hole is provided in the vicinity of the end of the separator for mixing the fuel gas immediately before the outflow and the oxidizing gas.

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