JP5543292B2 - In-vehicle fuel cell system - Google Patents

Description

  The present invention relates to an on-vehicle fuel cell system that is mounted on a vehicle, and includes a fuel cell that obtains electric power by a chemical reaction between a fuel gas and an oxidant gas, and a cooling medium supply device that supplies a cooling medium to the fuel cell.

  For example, in a polymer electrolyte fuel cell, an electrolyte membrane / electrode structure (MEA) 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 is provided by a pair of separators. It has a power generation unit (unit cell) sandwiched between them.

  This type of fuel cell normally constitutes a fuel cell stack in which a predetermined number (for example, several hundreds) of power generation units are stacked. The fuel cell stack is incorporated in an in-vehicle fuel cell system by being mounted on a fuel cell vehicle such as a fuel cell vehicle.

  For example, as shown in FIG. 5, a fuel cell system disclosed in Patent Document 1 includes a cooling water path 2 that circulates cooling water to the fuel cell 1, a cooling water circulation pump 3 that pumps the cooling water, and the cooling. A cooling system including a radiator 4 for radiating water is provided.

  The cooling water circulation pump 3 is mechanically connected to the pump motor 5. By rotating the pump motor 5, the cooling water circulation pump 3 is rotated to circulate the cooling water in the fuel cell 1. Heat generated in the fuel cell 1 is discharged outside the system by the radiator 4 through the cooling water.

  The cooling fan 6 is mechanically connected to the cooling fan motor 7. By rotating the cooling fan motor 7, the cooling fan 6 is rotated and blown to the radiator 4, and heat is released from the radiator 4 to the outside air. A thermostat 8 is disposed in the cooling water path 2.

  When the cooling water temperature is higher than a predetermined value, the thermostat 8 causes the cooling water to flow to the radiator 4 side. Conversely, when the cooling water temperature is lower than the predetermined value, the thermostat 8 supplies the cooling water to the radiator bypass path side 9. The temperature is controlled by controlling so that flows.

JP 2005-1000075 A

  However, in Patent Document 1 described above, a dedicated radiator bypass path 9 that bypasses the radiator 4 is provided in order to prevent low-temperature cooling water from flowing into the radiator 4. Therefore, there are problems that the layout performance is deteriorated and the entire system cannot be reduced in size.

  The present invention solves this kind of problem, and reliably prevents the cooling medium from becoming unnecessarily low, improves the layout and reduces the size of the entire system, and is also heated. An object is to provide an in-vehicle fuel cell system capable of improving the cooling performance of a medium.

  The present invention relates to an in-vehicle fuel cell system that is mounted on a vehicle, and includes a fuel cell that obtains electric power by a chemical reaction between a fuel gas and an oxidant gas, and a cooling medium supply device that supplies a cooling medium to the fuel cell. It is.

In this in-vehicle fuel cell system, the cooling medium supply device communicates with a cooling medium inlet communication hole and a cooling medium outlet communication hole provided in the fuel cell, circulates the cooling medium to the fuel cell, and dissipates heat. vessel, a heat exchange mechanism with an air blower and the case member, adjustment and pump for circulating the cold却媒body cold却媒member circulation passage is disposed in the cold却媒body circulation, is switching control based on the temperature of the cold却媒body And a valve.

The radiator is connected to a heat exchanging portion for circulating the cooling medium from the lower side to the upper side, one end of the heat exchanging portion, and an inlet for introducing the cooling medium discharged from the fuel cell and heat from the inlet. A first piping part having a first outlet for letting out the cooling medium without passing through the exchange part, and a second piping part having a second outlet for letting out the cooling medium while being connected to the other end side of the heat exchange part And. In this case, a 1st piping part is arrange | positioned under the heat exchange part, while a 2nd piping part is arrange | positioned above a heat exchange part. In particular, it is preferable that the first piping part extends along the lower end of the heat exchange part and is formed in a straight line so as to communicate the inlet through which the cooling medium flows in and the first outlet through which the cooling medium flows out.

The case member is provided so as to cover a part of the blower and the heat exchange part from the rear of the heat exchanger, and the adjustment valve communicates the first outlet and the second outlet with the cooling medium inlet based on the temperature of the cooling medium. Selectively connected to the hole.

Further, in this vehicle fuel cell system, the heat exchange mechanism is rearward from forward traveling direction of the vehicle, a radiator, Ru are arranged in this order of the blower and the case member.

According to the present invention, the first piping part that constitutes the radiator is provided with an inlet through which the cooling medium flows and a first outlet through which the cooling medium flows out from the inlet without passing through the heat exchange unit, the pipe portion, a second outlet for discharging the cold却媒body is provided. Then, under the switching control of the adjusting valve, in the low load (low temperature), the cooling medium that has flowed into the inlet of the first pipe part, coolant supply passage of the fuel cell from the first outlet of the first pipe section Has been leaked to. For this reason, a 1st piping part can function as a bypass flow path which detours a heat exchange part.

  This eliminates the need for a dedicated bypass flow path, improves layout, and facilitates downsizing of the entire system.

Moreover, the case member is provided so as to cover a part of the blower and the heat exchange unit. For this reason, the heat exchange part has a part (hereinafter also referred to as an open part) that is not covered by the case member, and the open part has another part (a part covered by the case member, hereinafter referred to as a cover). air volume of the part also called) good remote traveling air is often supplied. This is because the open portion is less subject to pressure loss due to the case member and the blower, travel air is easy to pass, and a large amount of travel air flows. Accordingly, the temperature difference between the traveling wind temperature and the cooling medium temperature is larger in the open part than in the covering part, and the high-temperature cooling medium can be cooled quickly.

1 is a schematic configuration diagram of a fuel cell system according to an embodiment of the present invention. It is a schematic perspective explanatory drawing of the cooling medium supply apparatus which comprises the said fuel cell system. It is operation | movement explanatory drawing of the said cooling medium supply apparatus at the time of low load. It is operation | movement explanatory drawing of the said cooling medium supply apparatus at the time of high load. 1 is a schematic explanatory diagram of a fuel cell system disclosed in Patent Document 1. FIG.

  As shown in FIG. 1, a fuel cell system 10 according to an embodiment of the present invention is incorporated in a vehicle, for example, a fuel cell automobile (not shown). FIG. 1 shows a schematic configuration of the fuel cell system 10, and the connection relationship of piping, for example, the vertical relationship and the horizontal relationship is different from the actual relationship. In particular, the cooling medium supply device 14 to be described later is actually set to the positional relationship shown in FIG.

  The fuel cell system 10 includes a fuel cell stack 12, a cooling medium supply device 14 for supplying a cooling medium to the fuel cell stack 12, and a fuel for supplying fuel gas (reactive gas) to the fuel cell stack 12. A gas supply device 16, an oxidant gas supply device 18 for supplying an oxidant gas (reactive gas) to the fuel cell stack 12, and a controller (ECU) 20 that controls the fuel cell system 10 as a whole. .

  In the fuel cell stack 12, a plurality of fuel cells 22 are stacked, and end plates 28a, 28b are disposed at both ends in the stacking direction via terminal plates 24a, 24b and insulating plates 26a, 26b. The fuel cell stack 12 includes, for example, a casing (not shown) having end plates 28a and 28b as end plates, or tie rods (not shown) that fasten the end plates 28a and 28b.

  The pair of terminal plates 24a and 24b are provided with power extraction terminals 30a and 30b. The power extraction terminals 30 a and 30 b are connected to a load circuit 32, and to the load circuit 32, a traveling drive motor 34 and auxiliary equipment (not shown) are connected.

  Each fuel cell 22 is, for example, a polymer electrolyte fuel cell, and includes an electrolyte membrane / electrode structure and a separator sandwiching the electrolyte membrane / electrode structure (not shown).

  The end plate 28 a is provided with a cooling medium inlet communication hole 54 a and a cooling medium outlet communication hole 54 b through which a cooling medium for cooling the fuel cell 22 circulates, extending in the stacking direction of the fuel cells 22. The end plate 28b includes a fuel gas inlet communication hole 56a and a fuel gas outlet communication hole 56b through which the fuel gas flows to the fuel cell 22, and an oxidant gas inlet communication hole 58a and an oxidant gas outlet communication hole through which the oxidant gas flows. 58b extending in the stacking direction of the fuel cells 22.

  As shown in FIGS. 1 and 2, the cooling medium supply device 14 communicates with a cooling medium inlet communication hole 54 a and a cooling medium outlet communication hole 54 b provided in the fuel cell stack 12, and supplies the cooling medium to the fuel cell stack 12. A cooling medium circulation path 60 to be circulated, and a radiator 62, a blower 64, and a case member (shroud) 66 are arranged in this order from the front (arrow A direction) to the rear (arrow B direction) of the fuel cell vehicle. A heat exchanging mechanism 68, a pump 70 that circulates the cooling medium in the cooling medium circulation path 60, an adjustment valve that is disposed in the cooling medium circulation path 60 and is controlled to be switched based on the temperature of the cooling medium, for example, And a thermostat 72.

  The radiator 62 is provided on the inlet side of the heat exchanging portion (core portion) 76 having the fins 74 and the heat exchanging portion 76, and allows the cooling medium discharged from the cooling medium outlet communication hole 54 b of the fuel cell stack 12 to flow. A first piping part (lower tank) 82 having an inlet 78 and a first outlet 80a for allowing the cooling medium to flow out into the cooling medium circulation path 60 and the outlet side of the heat exchanging part 76 are provided to cool the cooling medium. A second piping part (upper tank) 84 having a second outlet 80 b that flows out to the medium circulation path 60 is provided.

  The heat exchanging unit 76 employs an upflow for circulating the cooling medium from below to above, and the first piping unit 82 is disposed below the heat exchanging unit 76, while the second piping unit 84. Is disposed above the heat exchange section 76.

  Two fans 64 are provided on the left and right sides, and the case member 66 is provided so as to cover a part of the fan 64 and the heat exchanging unit 76. Specifically, the case member 66 is provided so as to cover a part above the blower 64 and the heat exchange unit 76 from the rear of the heat exchange unit 76 except for the first piping unit 82 and the second piping unit 84.

  The thermostat 72 selectively connects the first outlet 80a and the second outlet 80b to the cooling medium inlet communication hole 54a of the fuel cell stack 12 based on the temperature of the cooling medium. Specifically, one end side of the cooling medium circulation path 60 is connected to the inlet 78 of the first piping section 82, and the other end side of the cooling medium circulation path 60 is connected to the pump 70 and the thermostat 72. . The first outlet 80a of the first piping part 82 and one inlet of the thermostat 72 are connected via the first discharge pipe 86a, while the second outlet 80b of the second piping part 84 and the other of the thermostat 72 are connected. The inlet is connected via the second discharge pipe 86b.

  The fuel gas supply device 16 is connected to the fuel gas inlet communication hole 56 a and the fuel gas outlet communication hole 56 b of the fuel cell stack 12. The oxidant gas supply device 18 is connected to the oxidant gas inlet communication hole 58 a and the oxidant gas outlet communication hole 58 b of the fuel cell stack 12.

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

  First, as shown in FIG. 1, the fuel gas supply device 16 is driven, and the fuel gas is introduced into the fuel cell stack 12 through the fuel gas inlet communication hole 56a of the end plate 28b. On the other hand, the oxidant gas supply device 18 is driven, and external air that is oxidant gas is supplied into the fuel cell stack 12 through the oxidant gas inlet communication hole 58a of the end plate 28b.

  Therefore, in the fuel cell stack 12, fuel gas (hydrogen) supplied to the anode side and oxygen in the air supplied to the cathode side are consumed by an electrochemical reaction in the electrode catalyst layer, and power generation is performed. Done. Accordingly, electric power is supplied from the fuel cell stack 12 to the load circuit 32, and desired electric power is supplied to the travel drive motor 34 and auxiliary machines (not shown) via the load circuit 32. As a result, the fuel cell vehicle (not shown) can run.

  Further, in the cooling medium supply device 14, the cooling medium is introduced into the fuel cell stack 12 from the cooling medium circulation path 60 through the cooling medium inlet communication hole 54 a of the end plate 28 a under the action of the pump 70. After cooling the fuel cell 22, the cooling medium is discharged from the cooling medium outlet communication hole 54b of the end plate 28a to the cooling medium circulation path 60.

  During startup of the fuel cell stack 12 and during low load operation, the temperature of the cooling medium discharged from the fuel cell stack 12 is relatively low. The thermostat 72 connects the first outlet 80 a of the first piping part 82 to the coolant inlet communication hole 54 a of the fuel cell stack 12. For this reason, as shown in FIG. 3, the cooling medium discharged from the fuel cell stack 12 to the cooling medium circulation path 60 is introduced into the first piping part 82 from the inlet 78, and then the first piping part 82. The gas is discharged from the first outlet 80a to the first discharge pipe 86a.

  This cooling medium is supplied to the cooling medium circulation path 60 through the thermostat 72 and the pump 70. That is, the cooling medium is circulated to the cooling medium inlet communication hole 54 a of the fuel cell stack 12, bypassing the heat exchange part 76 of the radiator 62.

  Next, when the fuel cell stack 12 shifts to high load operation, the temperature of the cooling medium discharged from the fuel cell stack 12 becomes relatively high. Accordingly, the thermostat 72 connects the second outlet 80 b of the second piping portion 84 to the coolant inlet communication hole 54 a of the fuel cell stack 12.

  As a result, as shown in FIG. 4, the cooling medium introduced into the first piping part 82 from the inlet 78 moves upward from below along the fins 74 of the heat exchanging part 76, while the blower 64 and the traveling wind. Cooled by. Specifically, the cooling medium introduced into the first piping part 82 from the inlet 78 is in the highest temperature state, and first, the fin 74 part (open part) of the heat exchange part 76 not covered by the case member 66. ). For this reason, the cooling medium passes through the fin 74 portion (open portion) of the heat exchanging portion 76 to which the traveling wind hits most in the state of the highest temperature, and the cooling medium can be efficiently cooled. . The fin 74 portion (open portion) of the heat exchanging portion 76 has a pressure loss under a high load reduced more than other portions (covered portions) covered by the case member 66, so that traveling wind is easy to pass and a large amount This is because the running wind of the car circulates.

  The cooled cooling medium is introduced into the second pipe portion 84, discharged from the second outlet 80b to the second discharge pipe 86b, and from the cooling medium circulation path 60 through the thermostat 72 and the pump 70 to the cooling medium inlet communication hole. 54a.

  In this case, in the present embodiment, the first piping portion 82 that constitutes the radiator 62 is provided with an inlet 78 through which the cooling medium flows and a first outlet 80a through which the cooling medium flows out, while the second piping portion 84. Is provided with a second outlet 80b through which the cooling medium flows out. The thermostat 72 selectively connects the first outlet 80a and the second outlet 80b to the cooling medium inlet communication hole 54a of the fuel cell stack 12 based on the temperature of the cooling medium.

  Accordingly, when the load is low, the first outlet 80a of the first piping part 82 and the cooling medium inlet communication hole 54a are connected, so that the cooling medium that has flowed into the inlet 78 of the first piping part 82 flows into the first outlet. It flows out from 80a to the 1st discharge piping 86a (refer to Drawing 3). For this reason, the first piping section 82 can function as a bypass flow path that bypasses the heat exchange section 76.

  As a result, there is no need for a dedicated bypass flow path, so that the layout can be improved and the entire fuel cell system 10 can be easily reduced in size. In addition, the number of parts and the cost can be reduced, which is advantageous in that it is economical.

  Further, the cooling medium flows into the fin 74 portion (open portion) of the heat exchanging portion 76 not covered with the case member 66. For this reason, the pressure loss due to the case member 66 is not caused particularly at the time of a high load, and the cooling medium is efficiently cooled via the traveling wind generated by the traveling of the fuel cell vehicle (not shown). .

  In addition, this invention is not limited to embodiment mentioned above. For example, in this embodiment, the case member 66 is provided so as to cover the blower 64 and a part above the heat exchange unit 76 from the rear of the heat exchange unit 76, but the blower 64 from the rear of the heat exchange unit 76. In addition, a part below the heat exchanging unit 76 may be covered.

  Moreover, in this embodiment, although the air blower 64 is arrange | positioned in the back of the heat exchange part 76 with respect to the advancing direction of a fuel cell vehicle, you may arrange | position in the front of the said heat exchange part 76, for example.

DESCRIPTION OF SYMBOLS 10 ... Fuel cell system 12 ... Fuel cell stack 14 ... Cooling medium supply device 16 ... Fuel gas supply device 18 ... Oxidant gas supply device 20 ... Controller 22 ... Fuel cell 28a, 28b ... End plate 32 ... Load circuit 34 ... For driving | running | working Drive motor 54a ... Cooling medium inlet communication hole 54b ... Cooling medium outlet communication hole 60 ... Cooling medium circulation path 62 ... Radiator 64 ... Blower 66 ... Case member 68 ... Heat exchange mechanism 70 ... Pump 72 ... Thermostat 76 ... Heat exchange section 78 ... Inlet 80a, 80b ... Outlet 82, 84 ... Piping part 86a, 86b ... Exhaust pipe

Claims (3)

An in-vehicle fuel cell system mounted on a vehicle, comprising: a fuel cell that obtains electric power by a chemical reaction between a fuel gas and an oxidant gas; and a cooling medium supply device that supplies a cooling medium to the fuel cell.
The cooling medium supply device communicates with a cooling medium inlet communication hole and a cooling medium outlet communication hole provided in the fuel cell, and circulates the cooling medium to the fuel cell.
A heat exchange mechanism having a radiator, a blower and a case member;
A pump for circulating the cooling medium in the cooling medium circulation path;
An adjustment valve disposed in the cooling medium circulation path and controlled to be switched based on the temperature of the cooling medium;
With
The radiator is connected to one end side of the heat exchanging unit, a heat exchanging unit that circulates the cooling medium from the lower side to the upper side, and an inlet through which the cooling medium discharged from the fuel cell flows. A first piping part having a first outlet for letting out the cooling medium from the inlet without passing through the heat exchange part, and a first pipe part connected to the other end side of the heat exchange part, and for causing the cooling medium to flow out. A second piping part having two outlets ,
The first piping part is disposed at a lower part of the heat exchange part, while the second piping part is disposed at an upper part of the heat exchange part,
The first piping portion extends along a lower end of the heat exchange portion, and the first piping portion is linear so as to communicate an inlet through which the cooling medium flows in and a first outlet through which the cooling medium flows out. Formed into
Moreover, the case member is provided so as to cover a part of the blower and the heat exchange unit,
The on-board fuel cell system, wherein the regulating valve selectively connects the first outlet and the second outlet to the cooling medium inlet communication hole based on the temperature of the cooling medium. The in-vehicle fuel cell system according to claim 1, wherein the heat exchange mechanism is arranged in the order of the radiator, the blower, and the case member from the front to the rear in the traveling direction of the vehicle .
Before SL case member, vehicle fuel cell system, characterized in that provided from the rear of the heat exchanger over a portion of the upper of the blower and the heat exchanger unit. The in-vehicle fuel cell system according to any one of claims 1 and 2 ,
The inlet of the pre-Symbol cooling medium is provided at one longitudinal end of said first pipe section,
The on-vehicle fuel cell system, wherein the first outlet of the cooling medium is provided on the other end side in the longitudinal direction of the first piping section.

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