JP4412999B2 - Fuel cell starting method and fuel cell system - Google Patents

Description

  In the present invention, an electrolyte membrane / electrode structure in which an electrolyte membrane is disposed between a pair of electrodes, and a separator are laminated, and through the lamination direction, a reaction gas supply communication hole, a reaction gas discharge communication hole, a cooling medium supply Cooling in which a communication hole and a cooling medium discharge communication hole are formed, and the cooling medium is supplied along the surface direction of the electrolyte membrane / electrode structure in communication with the cooling medium supply communication hole and the cooling medium discharge communication hole The present invention relates to a fuel cell activation method for activating a fuel cell in which a medium flow path is formed, and a fuel cell system including the fuel cell.

  Generally, a polymer electrolyte fuel cell has an electrolyte membrane / electrode structure in which an anode side electrode and a cathode side electrode are disposed on both sides of an electrolyte membrane made of a polymer ion exchange membrane, and is sandwiched by separators. Yes. This type of fuel cell is normally used as a fuel cell stack by alternately stacking a predetermined number of electrolyte membrane / electrode structures and separators.

  In this fuel cell, a fuel gas supplied to the anode side electrode, for example, a gas mainly containing hydrogen (hereinafter also referred to as a hydrogen-containing gas) is ionized with hydrogen on an electrode catalyst, and is cathoded through an electrolyte membrane. Move to the side electrode side. Electrons generated during that time are taken out to an external circuit and used as direct current electric energy. The cathode side electrode is supplied with an oxidant gas, for example, a gas mainly containing oxygen or air (hereinafter also referred to as an oxygen-containing gas). And oxygen reacts to produce water.

  By the way, in this type of fuel cell, in order to maintain ionic conductivity, it is necessary to appropriately humidify the electrolyte membrane made of the polymer ion exchange membrane. Furthermore, water generated by the reaction is present at the cathode side electrode as described above. For this reason, it has been pointed out that if the fuel cell is started below the freezing point (below the freezing temperature of water), the water in the fuel cell is likely to be frozen and the electrochemical reaction is difficult to occur in the fuel cell. Yes.

  Therefore, for example, in Patent Document 1, an electrolyte membrane such as NAFION (registered trademark) manufactured by Dupont and an experimental membrane manufactured by Dow (product number XUX 13204.10) has a temperature of −20 ° C. It is disclosed that it is sufficiently ionically conductive to allow an electrochemical reaction in the fuel cell.

  This Patent Document 1 discloses a method for starting the operation of the fuel cell power generator from a temperature lower than the solidification temperature of water by using the above electrolyte membrane. The power generator includes a fuel cell stack that can be connected to the external electrical circuit to supply current to the external electrical circuit. The deposit includes at least one fuel cell, and the fuel cell includes a membrane electrode assembly including a positive electrode, a negative electrode, and a water-permeable ion exchange membrane inserted therebetween, The temperature of at least a part of the membrane electrode assembly is lower than the solidification temperature of water. The method includes a step of supplying a current from the deposit to the external electric circuit so that the temperature of a part of the membrane electrode assembly exceeds the solidification temperature of water.

JP 2000-512068A (FIG. 3)

  However, in Patent Document 1 described above, although the fuel cell can be operated even when the temperature is below the solidification temperature of water, the ionic conductivity of the electrolyte membrane is remarkably lowered when the fuel cell is started at a predetermined temperature or lower, and the desired value is obtained. There is a problem that it is difficult to quickly shift to the starting state.

  More specifically, there is a temperature characteristic in the ionic conductivity of a solid polymer electrolyte membrane usually used in a polymer electrolyte fuel cell, and the water inside the cluster that controls proton transfer is, for example, −10 It is confirmed that the ionic conductivity of the solid polymer electrolyte membrane is remarkably lowered by freezing in the range of from ℃ to -30 ℃. For this reason, when starting the fuel cell from a temperature below the temperature at which the water inside the cluster starts to freeze, there is a problem that the current necessary for warming up the fuel cell cannot be taken out from the fuel cell itself.

  On the other hand, the fuel cell generates water by power generation, and water is always present inside the fuel cell. Therefore, when the internal temperature is lowered after the fuel cell is stopped and the water existing in the vicinity of the electrode catalyst layer is frozen, the effective area of the catalyst is lowered and the applicable current is reduced. At that time, it is known that the freezing temperature of water present in the extremely small pores such as the electrode catalyst layer fluctuates to 0 ° C. or less depending on the pore diameter. Therefore, when starting the fuel cell from below this freezing temperature, there is a possibility that the current required for warming up the fuel cell cannot be taken out from the fuel cell itself.

  Furthermore, if the temperature is higher than both the freezing temperature of the water inside the cluster and the freezing temperature of the water in the electrode pores, an initial load can be applied, but as the power generation proceeds, the generated water becomes the electrode. Easily freezes in the diffusion layer. As a result, there is a problem that the gas diffusibility is lowered and the cell voltage is lowered.

  The present invention solves this type of problem, and can perform a quick and reliable start even in an environment below the freezing temperature of water, and can effectively reduce the fuel consumption to enable efficient operation. It is an object of the present invention to provide a battery starting method and a fuel cell system.

In the present invention, an electrolyte membrane / electrode structure in which an electrolyte membrane is disposed between a pair of electrodes, and a separator are laminated, and through the lamination direction, a reaction gas supply communication hole, a reaction gas discharge communication hole, a cooling medium supply Cooling in which a communication hole and a cooling medium discharge communication hole are formed, and the cooling medium is supplied along the surface direction of the electrolyte membrane / electrode structure in communication with the cooling medium supply communication hole and the cooling medium discharge communication hole medium flow path is formed, the coolant flow field is a starting method for starting a fuel cell Ru provided a plurality of projections located on both sides of the plurality of grooves and the groove.

Therefore, at the time of startup, the heated cooling medium is supplied from the cooling medium introduction port provided separately from the cooling medium supply communication hole and the cooling medium discharge communication hole to one of the protrusions of the cooling medium flow path. Therefore, it warmed cooling medium, after the warm-up to flow one of the protruding portions of the cooling medium flow path is discharged to the coolant discharge passage.

Also, the edge portion of the separator, sandwiching the a reaction gas discharge passage the oxygen-containing gas discharge passage, coolant discharge passage and the coolant inlet port is disposed, the cooling medium flow from the cooling medium inlet It is preferable that the heated cooling medium supplied to the passage passes through one of the protrusions of the cooling medium flow path and is discharged into the cooling medium discharge communication hole.

  Furthermore, the present invention provides an electrolyte membrane / electrode structure in which an electrolyte membrane is disposed between a pair of electrodes, and a separator, which are stacked and penetrated in the stacking direction to provide a reactive gas supply communication hole, a reactive gas discharge communication hole, A medium supply communication hole and a cooling medium discharge communication hole are formed, and the cooling medium is supplied along the surface direction of the electrolyte membrane / electrode structure in communication with the cooling medium supply communication hole and the cooling medium discharge communication hole. A fuel cell system including a fuel cell in which a cooling medium flow path is formed.

In this fuel cell system, a cooling medium supply communication hole and a cooling medium discharge communication hole are provided separately, and a cooling medium introduction port communicating with the cooling medium flow channel is supplied to the cooling medium flow channel from the cooling medium introduction port. the cooling medium that will be discharged into the coolant discharge passage being provided with a heating section for externally heating the fuel cell.

Furthermore, an oxidant gas discharge communication hole, which is a reaction gas discharge communication hole, and a cooling medium discharge communication hole and a cooling medium introduction port are arranged on the edge of the separator with the oxidant gas discharge communication hole interposed therebetween. It is preferable to be provided.

  In addition, a cooling medium supply mechanism communicating with the cooling medium supply communication hole and the cooling medium discharge communication hole is disposed outside the fuel cell, and the cooling medium supply mechanism is connected to the main flow path via a switching unit. It is preferable to include a start warming flow path that branches and communicates with the cooling medium introduction port, and a heater that is disposed in the start warming flow path and serves as a heating unit that heats the cooling medium.

  According to the present invention, since the heated cooling medium is supplied from the cooling medium introduction port to the cooling medium flow path and warmed up, it is possible to prevent the power generation water from being frozen, particularly at the time of starting below the freezing point. The fuel cell can be started quickly and reliably.

  In addition, the cooling medium introduction port is provided separately from the cooling medium supply communication hole, and it is not necessary to heat the entire cooling medium supplied to the cooling medium supply communication hole. Thereby, the cooling medium to be heated can be set to a supply amount necessary for warming up, and the amount of heat consumed by the external heat source is greatly reduced, which is economical.

  Further, since the temperature rises from the vicinity of the oxidant gas discharge communication hole, the vicinity of the oxidant gas discharge communication hole becomes a starting point of power generation, and the generated water is quickly discharged to the oxidant gas discharge communication hole. This prevents freezing and blockage of the in-plane flow path, particularly when starting below freezing.

  FIG. 1 is an explanatory diagram of a schematic configuration of a fuel cell system 10 of a first embodiment used in a fuel cell startup method according to the present invention.

  The fuel cell system 10 is mounted on a vehicle such as an automobile, and includes a polymer electrolyte fuel cell stack 12. The fuel cell stack 12 has a plurality of single cells 14 stacked in the direction of arrow A, and terminal plates 16a and 16b, insulating plates 18a and 18b, and end plates 20a and 20b are disposed at both ends in the stacking direction. A predetermined tightening load is applied between the end plates 20a and 20b.

  As shown in FIG. 2, the unit cell 14 includes an electrolyte membrane / electrode structure 22 and first and second separators 24 and 26 that sandwich the electrolyte membrane / electrode structure 22. For example, each of the first and second separators 24 and 26 is formed of a single metal plate, but may be formed of a carbon plate or the like.

  One end edge of the single cell 14 in the direction of arrow B communicates with each other in the direction of arrow A, which is the stacking direction, and an oxidant gas supply communication hole (reactive gas) for supplying an oxidant gas, for example, an oxygen-containing gas. Supply communication hole) 30a, a cooling medium supply communication hole 32a for supplying a cooling medium, and a fuel gas discharge communication hole (reactive gas discharge communication hole) 34b for discharging a fuel gas, for example, a hydrogen-containing gas. Arranged in the C direction (vertical direction).

  The other end edge of the single cell 14 in the direction of arrow B communicates with each other in the direction of arrow A, discharges a fuel gas supply communication hole (reactive gas supply communication hole) 34a for supplying fuel gas, and discharges the cooling medium. A cooling medium discharge communication hole 32b for discharging and an oxidant gas discharge communication hole (reactive gas discharge communication hole) 30b for discharging oxidant gas are arranged in the direction of arrow C.

  A cooling medium introduction port 35 having a drain function is formed below the oxidant gas discharge communication hole 30b, and a drain hole is positioned below the fuel gas discharge communication hole 34b. 35a is formed.

  The electrolyte membrane / electrode structure 22 includes, for example, a solid polymer electrolyte membrane 36 in which a perfluorosulfonic acid thin film is impregnated with water, and an anode side electrode 38 and a cathode side provided on both surfaces of the solid polymer electrolyte membrane 36. An electrode 40.

  The anode side electrode 38 and the cathode side electrode 40 include a gas diffusion layer made of carbon paper or the like, and an electrode catalyst layer in which porous carbon particles having a platinum alloy supported on the surface are uniformly applied to the surface of the gas diffusion layer. Respectively. The electrode catalyst layer is bonded to both surfaces of the solid polymer electrolyte membrane 36.

  A fuel gas passage 46 communicating with the fuel gas supply communication hole 34 a and the fuel gas discharge communication hole 34 b is formed on the surface 24 a of the first separator 24 facing the electrolyte membrane / electrode structure 22. Between the surface 24b opposite to the surface 24a of the first separator 24 and the surface 26b of the second separator 26, there is a cooling medium flow channel 48 communicating with the cooling medium supply communication hole 32a and the cooling medium discharge communication hole 32b. It is formed. The cooling medium channel 48 communicates with the cooling medium introduction port 35 and the drain hole 35a.

  The fuel gas channel 46 and the cooling medium channel 48 are integrally formed on the front and back surfaces by pressing the first separator 24. Specifically, for example, by forming the first separator 24 into a wave shape, the surface 24a is provided with a plurality of grooves 46a constituting the fuel gas passage 46, and the cooling medium passage 48 is formed on the surface 24b. A plurality of grooves 48a are provided. The plurality of groove portions 46a and 48a extend substantially linearly in the direction of arrow B, and the plurality of protrusion portions 46b and 48b are located on both sides of the arrow B direction, for example, by embossing on the surfaces 24a and 24b side, respectively. Protrusively provided.

  An oxidant gas flow path 50 communicating with the oxidant gas supply communication hole 30a and the oxidant gas discharge communication hole 30b is provided on the surface 26a of the second separator 26 facing the electrolyte membrane / electrode structure 22. The oxidant gas flow path 50 and the cooling medium flow path 48 are integrally formed on the front and back by pressing the second separator 26. The oxidant gas flow path 50 has a plurality of grooves 50a extending substantially linearly in the direction of arrow B, and a plurality of protrusions 50b located on both sides of the plurality of grooves 50a in the direction of arrow B are, for example, Provided by embossing.

  As shown in FIG. 1, a coolant supply mechanism 60 that communicates with the coolant flow path 48 is disposed outside the fuel cell stack 12. The cooling medium supply mechanism 60 includes a circulation flow path 62 which is a main flow path communicating with the cooling medium supply communication hole 32a and the cooling medium discharge communication hole 32b. A cooling medium circulation pump 64, a radiator 66, and a thermostat 68 are connected to the circulation flow path 62, and a bypass flow path 70 that bypasses the radiator 66 is connected to the thermostat 68.

  Downstream of the pump 64, the start warm-up flow path 74 is branched through switching means, for example, a three-way switching valve 72. A heater (heating unit) 76 for heating the cooling medium is connected to the start warm-up flow path 74, and the start warm-up flow path 74 communicates with the cooling medium introduction port 35. A drain valve 78 is connected to each of the cooling medium introduction port 35 and the drain hole 35a.

  The operation of the fuel cell system 10 configured as described above will be described below.

  As shown in FIG. 1, an oxidant gas that is an oxygen-containing gas such as air, a fuel gas such as a hydrogen-containing gas, and a cooling medium such as pure water or ethylene glycol are supplied into the fuel cell stack 12. For this reason, as shown in FIG. 2, the oxidant gas is introduced into the oxidant gas flow path 50 of the second separator 26 from the oxidant gas supply communication hole 30a, and this oxidant gas passes through the electrolyte membrane / electrode structure 22. It moves along the cathode side electrode 40 which comprises.

  The fuel gas is introduced from the fuel gas supply communication hole 34 a into the fuel gas flow path 46 of the first separator 24 and moves along the anode side electrode 38 constituting the electrolyte membrane / electrode structure 22. Therefore, in the electrolyte membrane / electrode structure 22, the oxidant gas supplied to the cathode side electrode 40 and the fuel gas supplied to the anode side electrode 38 are consumed by an electrochemical reaction in the electrode catalyst layer, thereby generating power. Is done.

  The oxidant gas consumed by being supplied to the cathode side electrode 40 is discharged in the direction of arrow A along the oxidant gas discharge communication hole 30b. Similarly, the fuel gas consumed by being supplied to the anode electrode 38 is discharged in the direction of arrow A along the fuel gas discharge communication hole 34b.

  Further, in the cooling medium supply mechanism 60, the cooling medium is supplied to the cooling medium supply communication hole 32a through the circulation flow path 62 under the driving action of the pump 64 (see FIG. 1). The cooling medium is introduced into the cooling medium flow path 48 between the first and second separators 24 and 26, and then flows along the direction of arrow B in FIG. After cooling the electrolyte membrane / electrode structure 22, the cooling medium is returned to the circulation channel 62 from the cooling medium discharge communication hole 32 b, and again enters the cooling medium supply communication hole 32 a through the circulation channel 62. Supplied.

  At this time, when the temperature of the cooling medium becomes equal to or higher than the set temperature, the thermostat 68 is activated. Accordingly, the cooling medium is sent to the radiator 66 and forcibly cooled, and then supplied to the cooling medium supply communication hole 32a.

  By the way, when the fuel cell system 10 is started at a low temperature, for example, in an environment below freezing point, the cooling medium supply mechanism 60 switches the three-way switching valve 72 to connect the pump 64 to the start warm-up flow path 74. For this reason, an external circulation channel is formed between the cooling medium discharge communication hole 32 b and the cooling medium introduction port 35. Further, the heater 76 is energized, whereby the cooling medium in the start warm-up flow path 74 is heated.

  Next, as shown in FIG. 3, when the pump 64 is driven, the cooling medium heated by the heater 76 is supplied to the cooling medium introduction port 35 via the start warm-up flow path 74. The cooling medium supplied to the cooling medium introduction port 35 is introduced into the cooling medium flow path 48, warms up while moving between the plurality of protrusions 48b, and is discharged into the cooling medium discharge communication hole 32b. .

  At that time, in the first embodiment, the cooling medium introduction port 35 is provided below the oxidant gas discharge communication hole 30b, and the coolant discharge hole 32b is provided above the oxidant gas discharge communication hole 30b. Is provided. Accordingly, since the heated cooling medium flows in the vicinity of the oxidant gas discharge communication hole 30b, the temperature rises from the vicinity of the oxidant gas discharge communication hole 30b. Therefore, the vicinity of the oxidant gas discharge communication hole 30b becomes a starting point of power generation, and the generated water is quickly discharged into the oxidant gas discharge communication hole 30b.

  As a result, freezing and clogging of the oxidant gas flow path 50 due to power generation generated water can be prevented, particularly at the time of starting below freezing point, and power generation stability during warm-up at a cryogenic start is effectively improved. In addition, since power generation is concentrated in the vicinity of the oxidant gas discharge communication hole 30b, warm-up is performed well in a short time, and the amount of heat for warm-up is greatly reduced compared to the case where the entire single cell 14 is warmed up. Is done. Therefore, it is possible to quickly and surely start each single cell 14 while saving energy.

  Furthermore, the cooling medium introduction port 35 is provided separately from the cooling medium supply communication hole 32a, and it is not necessary to heat the entire cooling medium supplied to the cooling medium supply communication hole 32a. Thereby, the cooling medium to be heated can be set to a supply amount necessary for warming up, and the amount of heat consumed by the heater 76 as an external heat source is greatly reduced, which is economical.

  Each single cell 14 is warmed up by a heated cooling medium and self-heating generated by power generation of the single cell 14. When the temperature of the fuel cell stack 12 reaches a predetermined temperature or higher, the three-way switching valve 72 is switched to connect the pump 64 to the circulation flow path 62 while the heater 76 is deenergized. The predetermined temperature is preferably set to a temperature lower than the set temperature at which the thermostat 68 described above is activated and the circulation flow path 62 is switched to the radiator 66. Thereby, when the three-way switching valve 72 is switched, it is possible to prevent a rapid temperature change due to the introduction of the cooling medium not heated by the heater 76 into the fuel cell stack 12.

  FIG. 4 is a schematic configuration explanatory diagram of a fuel cell system 80 according to the second embodiment of the present invention. The same components as those of the fuel cell system 10 according to the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. In the third and fourth embodiments described below, the detailed description is also omitted.

  The fuel cell system 80 includes a cooling medium supply mechanism 82 disposed outside the fuel cell stack 12. The cooling medium supply mechanism 82 has a three-way switching valve 84 as switching means interposed between the thermostat 68 and the cooling medium supply communication hole 32 a in the circulation flow path 62. A start warm-up flow path 86 is connected to the three-way switching valve 84 and the cooling medium introduction port 35, and a heater (heating unit) 88 is connected to the start warm-up flow path 86.

  In the second embodiment configured as described above, when the fuel cell system 80 is started at a low temperature, the three-way switching valve 84 constituting the cooling medium supply mechanism 82 is switched, and the pump 64 is connected to the start warm-up flow path 86. The Accordingly, under the driving action of the pump 64, the cooling medium discharged from the cooling medium discharge communication hole 32 b to the circulation flow path 62 is sent from the bypass flow path 70 to the start warm-up flow path 86 via the three-way switching valve 84. . Further, the cooling medium is heated through a heater 88 disposed in the start warm-up flow path 86 and then introduced into the cooling medium flow path 48 from the cooling medium introduction port 35.

  Thereby, at the time of starting below the freezing point, the effects similar to those of the first embodiment can be obtained, such as preventing freezing of the oxidant gas flow path 50 by the power generation generated water and starting each single cell 14 quickly and reliably. can get.

  FIG. 5 is a schematic configuration explanatory diagram of a fuel cell system 90 according to the third embodiment of the present invention.

  The fuel cell system 90 includes a cooling medium supply mechanism 92 disposed outside the fuel cell stack 12. In the cooling medium supply mechanism 92, a three-way switching valve 94, which is a switching means, is disposed between the cooling medium discharge communication hole 32 b and the pump 64. The three-way switching valve 94 and the cooling medium introduction port 35 are connected via a start warm-up flow path 96, and the start warm-up flow path 96 includes a sub pump 98 and a heater (heating unit) 100. Connected.

  In the third embodiment configured as described above, when the fuel cell system 90 is started at a low temperature, the three-way switching valve 94 is switched so that the coolant discharge communication hole 32b and the coolant supply port 35 are connected to the start warm-up flow path. 96. When the sub pump 98 is driven, the cooling medium discharged from the cooling medium discharge communication hole 32 b is sent to the start warm-up flow path 96 and heated through the heater 100, and then the cooling medium introduction port 35. To the cooling medium flow path 48.

  Therefore, in the third embodiment, the same effects as those in the first and second embodiments can be obtained, for example, the below-freezing start can be performed quickly and reliably. In addition, the auxiliary pump 98 that consumes much less power than the pump 64 can be used, and the energy saving effect is more reliably achieved.

  FIG. 6 is an exploded perspective view of the single cell 110 constituting the fuel cell system according to the fourth embodiment of the present invention. In addition, the same referential mark is attached | subjected to the component same as the single cell 14 which comprises the fuel cell system 10 which concerns on 1st Embodiment, and the detailed description is abbreviate | omitted. In the fifth and sixth embodiments described below, the detailed description is also omitted.

  The unit cell 110 includes first and second separators 112 and 114 that sandwich the electrolyte membrane / electrode structure 22. A plurality of protrusions 116a are formed on the surface 112a of the first separator 112 facing the electrolyte membrane / electrode structure 22, for example, by embossing, while the other surface 112b is similarly formed with a plurality of protrusions 116b. Is provided, for example, by embossing. A fuel gas flow path 46 is formed on the surface 121a by a plurality of protrusions 116a, and a cooling medium flow path 48 is formed on the surface 112b by a plurality of protrusions 116b.

  A plurality of protrusions 118a and 118b are formed to protrude from the surface 114a and the other surface 114b of the second separator 114 facing the electrolyte membrane / electrode structure 22 by, for example, embossing. The oxidant gas flow path 50 is formed through the plurality of protrusions 118a, and the cooling medium flow path 48 is formed through the plurality of protrusions 118b and the plurality of protrusions 116b of the first separator 112.

  In the fourth embodiment configured as described above, the heated cooling medium supplied from the cooling medium introduction port 35 to the cooling medium flow path 48 along the plurality of protrusions 116b and 118b at the time of low temperature start. And is discharged to the cooling medium discharge communication hole 32b. As a result, the heated cooling medium is concentrated and flows in the vicinity of the oxidant gas discharge communication hole 30b, and power generation is started from the vicinity of the oxidant gas discharge communication hole 30b.

  FIG. 7 is an exploded perspective view of the single cell 120 constituting the fuel cell system according to the fifth embodiment of the present invention.

  The unit cell 120 includes first and second separators 122 and 124 that sandwich the electrolyte membrane / electrode structure 22. On the surface 122b of the first separator 122 opposite to the surface 122a facing the electrolyte membrane / electrode structure 22, a guide projection 126 for guiding the cooling medium from the cooling medium introduction port 35 to the cooling medium discharge communication hole 32b. A plurality of are formed. Each of the guide protrusions 126 has an oval shape or an oval shape, and forms a flow path from the cooling medium introduction port 35 to the cooling medium discharge communication hole 32b.

  Similarly, the second separator 124 has a plurality of guide protrusions 128 for forming a flow path from the cooling medium introduction port 35 to the cooling medium discharge communication hole 32b on the surface where the cooling medium flow path 48 is formed. The

  In the fifth embodiment configured as described above, for the heated cooling medium, the cooling medium channel 48 is connected to the cooling medium discharge communication hole 32b from the cooling medium introduction port 35 via the guide protrusions 126 and 128. The passage is formed. For this reason, the heated cooling medium supplied from the cooling medium introduction port 35 to the cooling medium flow path 48 at the time of cold start is guided by the guide protrusions 126 and 128, and the oxidant gas discharge communication hole 30b. Surely flows to the cooling medium discharge communication hole 32b. Therefore, there is an effect that reliable power generation is started from the vicinity of the oxidizing gas discharge communication hole 30b.

  FIG. 8 is an exploded perspective view of the single cell 130 constituting the fuel cell system according to the sixth embodiment of the present invention.

  The unit cell 130 includes first and second separators 132 and 134 that sandwich the electrolyte membrane / electrode structure 22. A plurality of protrusions 116b are formed on the surface of the first separator 132 forming the cooling medium flow path 48, and a plurality of flow paths for forming a flow path from the cooling medium introduction port 35 to the cooling medium discharge communication hole 32b are formed. The guide projection 126 is formed. A plurality of protrusions 118b are formed on the surface of the second separator 134 on which the cooling medium flow path 48 is formed, and a plurality of flow paths for forming a flow path from the cooling medium introduction port 35 to the cooling medium discharge communication hole 32b are formed. The guide protrusion 128 is formed.

  Thereby, at the time of low temperature start, the heated cooling medium supplied to the cooling medium introduction port 35 can smoothly and reliably flow into the cooling medium discharge communication hole 32b via the guide protrusions 126 and 128. .

BRIEF DESCRIPTION OF THE DRAWINGS It is schematic structure explanatory drawing of the fuel cell system of 1st Embodiment used for the starting method of the fuel cell which concerns on this invention. It is a disassembled perspective view of the single cell which comprises the said fuel cell. It is operation | movement explanatory drawing when the heated cooling medium is supplied to the cooling medium inlet of the 1st separator which comprises the said single cell. It is a schematic structure explanatory drawing of the fuel cell system concerning the 2nd Embodiment of this invention. It is schematic structure explanatory drawing of the fuel cell system which concerns on the 3rd Embodiment of this invention. It is a disassembled perspective explanatory drawing of the single cell which comprises the fuel cell system which concerns on the 4th Embodiment of this invention. It is a disassembled perspective explanatory drawing of the single cell which comprises the fuel cell system which concerns on the 5th Embodiment of this invention. It is a disassembled perspective explanatory drawing of the single cell which comprises the fuel cell system which concerns on the 6th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 80, 90 ... Fuel cell system 12 ... Fuel cell stack 14, 110, 120, 130 ... Single cell 22 ... Electrolyte membrane electrode assembly 24, 26, 112, 114, 122, 124, 132, 134 ... Separator 30a ... oxidant gas supply communication hole 30b ... oxidant gas discharge communication hole 32a ... cooling medium supply communication hole 32b ... cooling medium discharge communication hole 34a ... fuel gas supply communication hole 34b ... fuel gas discharge communication hole 35 ... cooling medium introduction port 35a ... Drain hole 36 ... Solid polymer electrolyte membrane 38 ... Anode side electrode 40 ... Cathode side electrode 46 ... Fuel gas flow path 48 ... Cooling medium flow path 46a, 48a, 50a ... Groove parts 46b, 48b, 50b, 116a, 116b, 118a 118b... Projection 50. Oxidant gas flow path 60, 82, 92... Cooling medium supply mechanism 62. Circulation flow path 64, 9 ... pump 66 ... radiator 68 ... Thermostat 70 ... bypass passage 72,84,94 ... three-way valve 74,86,96 ... starting warm-up channel 76,88,100 ... heaters 126, 128 ... guide protrusion

Claims (5)

An electrolyte membrane / electrode structure in which an electrolyte membrane is disposed between a pair of electrodes and a separator are laminated, and penetrate in the laminating direction to react gas supply communication holes, reaction gas discharge communication holes, cooling medium supply communication holes, and cooling. A medium discharge communication hole is formed, and a cooling medium flow path that supplies the cooling medium along the surface direction of the electrolyte membrane / electrode structure communicates with the cooling medium supply communication hole and the cooling medium discharge communication hole. is formed, the cooling medium passage is a fuel cell starting method for starting the fuel cell Ru provided a plurality of projections located on both sides of the plurality of grooves and the groove,
The cooling medium supply communication hole and the cooling medium discharge communication hole supply a heated cooling medium to one of the protrusions of the cooling medium flow path from a cooling medium introduction port provided separately, and further A method for starting a fuel cell, wherein the heated cooling medium is discharged from one of the protrusions of the cooling medium flow path into the cooling medium discharge communication hole. 2. The start-up method according to claim 1, wherein the cooling medium discharge communication hole and the cooling medium introduction port are disposed at an edge of the separator with the oxidizing gas discharge communication hole being the reaction gas discharge communication hole interposed therebetween. And
The heated cooling medium supplied from the cooling medium introduction port to the cooling medium flow path passes through one of the protrusions of the cooling medium flow path and is discharged to the cooling medium discharge communication hole. A method for starting a fuel cell. An electrolyte membrane / electrode structure in which an electrolyte membrane is disposed between a pair of electrodes and a separator are laminated, and penetrate in the laminating direction to pass through a reaction gas supply hole, a reaction gas discharge hole, a cooling medium supply hole, and cooling A medium discharge communication hole is formed, and a cooling medium flow path that supplies the cooling medium along the surface direction of the electrolyte membrane / electrode structure communicates with the cooling medium supply communication hole and the cooling medium discharge communication hole. A fuel cell system comprising a fuel cell to be formed,
The cooling medium supply communication hole and the cooling medium discharge communication hole are provided separately, and a cooling medium introduction port communicating with the cooling medium flow path;
A heating unit wherein the cooling medium introduced is fed to the cooling medium flow passage from the inlet to the cooling medium that will be discharged into the coolant discharge passage, heated outside of the fuel cell,
A fuel cell system comprising: 4. The fuel cell system according to claim 3, wherein an edge portion of the separator has an oxidant gas discharge communication hole which is the reaction gas discharge communication hole,
Sandwiching the oxidant gas discharge communication hole, the cooling medium discharge communication hole and the cooling medium introduction port,
A fuel cell system comprising: 5. The fuel cell system according to claim 3, wherein a cooling medium supply mechanism that communicates with the cooling medium supply communication hole and the cooling medium discharge communication hole is disposed outside the fuel cell,
The cooling medium supply mechanism is a start warm-up flow path that branches from the main flow path via a switching unit and communicates with the cooling medium introduction port;
A heater that is the heating unit that is disposed in the startup warm-up flow path and heats the cooling medium;
A fuel cell system comprising:

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