JP2003217628A - Fuel cell unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the mountability of a fuel cell unit on a vehicle by miniaturizing the fuel cell unit including an intermediate heat exchanger. <P>SOLUTION: A fuel cell 10 and the intermediate heat exchanger 30 to cool the cooling water for the fuel cell are integrated with each other, and accommodated in a casing. Since a pipe to connect the intermediate heat exchanger 30 to the fuel cell 10 can be omitted, the number of components can be reduced, the fuel cell unit including the intermediate heat exchanger 30 can be miniaturized, and the mountability thereof on the vehicle can be improved. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell unit and is effective when applied to transportation equipment such as an electric vehicle.

[0002]

2. Description of the Related Art A general fuel cell is constructed by stacking a plurality of fuel cells in order to obtain a predetermined output voltage. Needs to be cooled with cooling water like the engine and the inverter to maintain the fuel cell, that is, the fuel cell at an appropriate temperature.

As a method of cooling the fuel cell, as shown in FIG. 1, intermediate heat exchange is performed between the fuel cell cooling water circulating in the fuel cell 10 and the radiator cooling water circulating in the heat radiation radiator 20. A method is known in which heat is exchanged through the container 30 to cool the fuel cell (hereinafter, this method is referred to as an indirect cooling method).

This is as shown in FIG.
0 has the following advantages as compared with a system in which cooling water is directly circulated between the radiator 0 and the radiator 20 (hereinafter referred to as a direct cooling system).

1. Cooling water circuit (piping) on the fuel cell 10 side
Since the cooling water becomes shorter, the amount of cooling water circulating in the fuel cell can be reduced. That is, it is possible to quickly raise the temperature of the fuel cell to a predetermined temperature when the fuel cell is started, and to shorten the warm-up operation time.

2. If the cooling water that circulates in the fuel cell has electrical conductivity, electric leakage is likely to occur, so it is usually necessary to use non-ionized water such as pure water as the cell cooling water. However, there is a high possibility that nonionic water will also become ionic water over time due to the metal ions eluted from the metal pipes or the like forming the circuit of the battery cooling water.

Therefore, according to the indirect cooling method, the amount of cooling water on the fuel cell side and the piping can be reduced, and the radiator and the fuel cell cooling which are likely to be directly touched by the user or service person. Since it is electrically insulated from water, it is possible to prevent electric leakage to the radiator side.

However, the indirect cooling method can reduce the amount of cooling water and piping on the fuel cell side as compared with the direct cooling method, but the piping for connecting the intermediate heat exchanger and the fuel cell is required, and the number of parts increases. At the same time, the fuel cell unit including the intermediate heat exchanger becomes large in size, and there is a problem that the mountability on the vehicle is particularly poor.

An object of the present invention is to solve the above problems.

[0010]

In order to achieve the above object, the present invention provides a fuel cell (10) in which a plurality of fuel battery cells for generating electric power by a chemical reaction are stacked in the invention described in claim 1. ) Is integrated with the fuel cell (10) adjacent to the end of the fuel cell in the stacking direction.
0) Circulating water for batteries and radiator for heat dissipation (2
0) is provided with an intermediate heat exchanger (30) for exchanging heat with the cooling water for radiator circulating inside.

As a result, since the pipe connecting the intermediate heat exchanger (30) and the fuel cell (10) can be eliminated, the number of parts can be reduced and the intermediate heat exchanger (30) is included. Further, the fuel cell unit can be downsized, and in particular, the mountability on the vehicle can be improved.

According to the second aspect of the present invention, the battery cooling water tube (31) through which the battery cooling water flows and the radiator cooling water tube (32) through which the radiator cooling water flows are connected to the fuel cell unit. It is desirable to form the intermediate heat exchanger (30) by alternately stacking the same in the same stacking direction.

According to the third aspect of the invention, the intermediate heat exchanger (30) is characterized in that the flow of the cooling water for the battery and the flow of the cooling water for the radiator are opposed to each other. .

As a result, the heat exchange efficiency can be improved.

The invention according to claim 4 is characterized in that a heat insulating member (34) for suppressing heat transfer is arranged between the intermediate heat exchanger (30) and the fuel cell (10). And

As a result, only the vicinity of the intermediate heat exchanger (30) of the fuel cell (10) can be prevented from being locally cooled, so that the power generation efficiency can be prevented from lowering.

In the invention described in claim 5, the intermediate heat exchanger (30) and the fuel cell (10) include the casing (50).
It is characterized by being stored inside.

As a result, the fuel cell unit can be handled and installed easily.

Incidentally, the reference numerals in the parentheses of the above-mentioned means are examples showing the correspondence with the concrete means described in the embodiments described later.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment)
The fuel cell unit according to the present invention is applied to an electric vehicle, and FIG. 1 is a schematic diagram showing a cooling system of a fuel cell (FC stack) 10. It is the same as the indirect cooling method described in the section "."

In the present embodiment, the fuel cell 10 and the intermediate heat exchanger 20 are integrated to form a fuel cell unit, and FIG. 2 is a schematic view of the fuel cell unit according to the present embodiment. .

The fuel cell 10 comprises a plurality of fuel cell units 1 each of which generates electric power by a chemical reaction between hydrogen and oxygen.
0a is laminated, and the intermediate heat exchanger 30 is integrated with the fuel cell 10 adjacent to the end side in the stacking direction of the fuel cell by brazing so as to separate the battery cooling water and the radiator cooling water. Exchange heat.

Here, as shown in FIG. 3, the intermediate heat exchanger 30 has a battery cooling water tube 3 through which battery cooling water flows.
1 and radiator cooling water tubes 32 through which radiator cooling water flows are alternately stacked in the same direction as the stacking direction of the fuel cells 10a.
32 is configured by stacking a plurality of plates 33a (see FIG. 4) formed in a predetermined shape, like an evaporator of a vehicle air conditioner.

In this embodiment, two types of plates 33a are formed by press-molding a metal plate such as stainless steel having excellent corrosion resistance, and these two types of plates are bonded together as shown in FIG. 4 (a). The tube layers 33 are laminated to form the tube layers 33, and the tube layers 33 are alternately turned upside down to form the cooling water tubes 31 and the radiator cooling water tubes 32 as shown in FIG. There is.

Incidentally, each tube layer 33, that is, the cooling water tube 31 and the radiator cooling water tube 32.
Are integrated by brazing, and guide the cooling water flow to the surface of the plate 33a where the cooling water flows, as shown in FIGS. 4B and 4C, and increase the heat transfer area. The fin 33b is provided.

Further, as is clear from FIGS. 5 and 6 (b) to (d), the intermediate heat exchanger 30 is arranged so that the flow of the cooling water for the battery and the flow of the cooling water for the radiator are opposite flows. The cooling water tubes 31 and the radiator cooling water tubes 32 are alternately stacked to improve heat exchange efficiency, and as shown in FIG. 3, a tube layer 33 constituting the intermediate heat exchanger 30. Among them, the tube layer 33 that comes into contact with the axial end surface of the fuel cell 10 is a dummy tube through which cooling water does not flow, and as a heat insulating member that suppresses heat transfer between the intermediate heat exchanger 30 and the fuel cell 10. The heat insulating layer 34 is configured.

Incidentally, FIGS. 6 (b) to 6 (d) are shown in FIG.
It shows the flow of cooling water in the cross section shown in (a).

In the present embodiment, the pump 40 for circulating the battery cooling water is also the intermediate heat exchanger 3 as shown in FIG.
It is integrated with 0 and this pump 40 and pump 40
As shown in FIG. 7, the fuel cell unit including the motor 41 that drives the motor is housed in a rigid casing 50 made of metal or the like.

Next, the features of this embodiment will be described.

In this embodiment, since the fuel cell 10 and the intermediate heat exchanger 30 are integrated, the intermediate heat exchanger 30
Since the pipe connecting the fuel cell 10 and the fuel cell 10 can be eliminated, the number of parts can be reduced, and the fuel cell unit including the intermediate heat exchanger 30 can be downsized. The mountability can be improved.

Further, since the heat insulating layer 34 is provided between the fuel cell 10 and the intermediate heat exchanger 30, the fuel cell 10
Of these, only the vicinity of the intermediate heat exchanger 30 can be prevented from being locally cooled, and the power generation efficiency can be prevented from lowering.

Further, the intermediate heat exchanger 30 and the fuel cell 10
However, since it is housed in the casing 50, the fuel cell unit can be handled and installed easily.

(Second Embodiment) In the first embodiment, the pump 40 and the motor 41 are housed in the casing 50, but in the present embodiment, at least the motor 41 is provided outside the casing 50 as shown in FIGS. It was installed in.
8 shows an example in which only the motor 41 is installed outside the casing 50, and FIG. 9 shows an example in which the pump 40 and the motor 41 are installed outside the casing 50.

This makes it possible to prevent hydrogen from leaking from the fuel cell 10 for some reason from being ignited by the spark of the motor 41.

(Third Embodiment) In the first embodiment, the fuel cell 10 and the intermediate heat exchanger 30 are integrated by brazing, but in the present embodiment, as shown in FIG.
The intermediate heat exchanger 30 is integrated with the fuel cell 10 so that the intermediate heat exchanger 30 is sandwiched between the end plate 11 and the plate 52 by tightening the bolts 51 penetrating the zero end plate 11 and the plate 52. It was done.

(Fourth Embodiment) In the present embodiment, as shown in FIG. 11, an ion exchange resin filter 53 for removing ions eluted in the battery cooling water is provided.

(Fifth Embodiment) In the above-described embodiment, the cooling water tube 31 and the radiator cooling water tube 3 are used.
Although 2 is made of metal, in the present embodiment, as shown in FIG. 12, the plate 33a is made of non-conductive resin or ceramics. In this case, it is necessary to dispose a sealing material such as packing on the mating surface of the plate 33a.

In the present embodiment, the plate 33a
Since the resin is molded with a non-conductive resin or ceramics, there is no possibility that ions will be eluted in the cold cooling water for the battery, so that the leakage resistance can be improved.

(Other Embodiments) In the above-mentioned embodiments, the heat insulating layer 34 is constituted by the dummy tube, but the present invention is not limited to this, and a material having a small thermal conductivity such as resin or rubber is used. Fuel cell 10
And the intermediate heat exchanger 30 may be interposed.

Further, in the above-mentioned embodiment, the fuel cell 10 of the type in which hydrogen and oxygen are chemically reacted to generate electricity is used, but the present invention is not limited to this, and methanol and oxygen are directly added. A fuel cell of the type that reacts to generate electricity may be used.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a cooling system of a fuel cell.

FIG. 2 is a schematic view of a fuel cell unit according to the first embodiment of the present invention.

FIG. 3 is a schematic view of a fuel cell unit according to the first embodiment of the present invention.

FIG. 4 (a) is a perspective view showing a tube layer of the intermediate heat exchanger according to the first embodiment of the present invention, and (b), (c).
FIG. 4 is a front view of the plate.

FIG. 5 is an assembly explanatory diagram of a cooling water tube and a radiator cooling water tube in the intermediate heat exchanger according to the first embodiment of the present invention.

FIG. 6 is an explanatory diagram illustrating a flow of cooling water in the intermediate heat exchanger according to the first embodiment of the present invention.

FIG. 7 is a schematic view showing a state where the fuel cell unit according to the first embodiment of the present invention is housed in a casing.

FIG. 8 is a schematic diagram showing a state in which a fuel cell unit according to a second embodiment of the present invention is housed in a casing.

FIG. 9 is a schematic diagram showing a state in which a fuel cell unit according to a second embodiment of the present invention is housed in a casing.

FIG. 10 is a schematic diagram showing a state in which a fuel cell unit according to a third embodiment of the present invention is housed in a casing.

FIG. 11 is a schematic view showing a state in which a fuel cell unit according to a fourth embodiment of the present invention is housed in a casing.

FIG. 12 is a schematic diagram showing a state in which a fuel cell unit according to a fifth embodiment of the present invention is housed in a casing.

FIG. 13 is a schematic diagram of a cooling system of a fuel cell.

[Explanation of symbols]

10 ... Fuel cell, 30 ... Intermediate heat exchanger.

Claims (5)

[Claims] 1. A fuel cell (10) in which a plurality of fuel cells that generate electric power by a chemical reaction are stacked, and an integral part of the fuel cell (10) adjacent to an end side in the stacking direction of the fuel cells. And an intermediate heat exchanger (30) for exchanging heat between the cell cooling water that circulates in the fuel cell (10) and the radiator cooling water that circulates in the radiator radiator (20). And a fuel cell unit. 2. The intermediate heat exchanger (30) comprises a battery cooling water tube (31) through which the battery cooling water flows, and a radiator cooling water tube (32) through which the radiator cooling water flows. The fuel cell unit according to claim 1, wherein the fuel cell units are alternately stacked in the same direction as the stacking direction of the fuel battery cells. 3. The intermediate heat exchanger (30) is configured such that the flow of the battery cooling water and the flow of the radiator cooling water are opposed to each other. 2. The fuel cell unit according to 2. 4. A heat insulating member (3) for suppressing heat transfer between the intermediate heat exchanger (30) and the fuel cell (10).
4) is provided, The fuel cell unit according to any one of claims 1 to 3. 5. The intermediate heat exchanger (30) and the fuel cell (10) are housed in a casing (50) according to any one of claims 1 to 4. Fuel cell unit.