JP2003234121A - Water recovery device of fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device to make the amount of recovered water more in the device of recovering moisture in the exhaust gas by cooling the exhaust gas flowed out of a fuel cell by means of a condenser. <P>SOLUTION: The moisture in the exhaust gas discharged from the exit side of the condenser 2 is made adsorbed to a desiccant at an adsorption zone 4 of a desiccant dehumidifier 3, the moisture adsorbed at the desiccant by a high temperature discharged gas 1 is removed at a desorption zone 5, and the discharged gas containing its moisture is led to the condenser 2. <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 water recovery system for efficiently recovering water in exhaust gas flowing out from a fuel cell by a condenser in a system such as a fuel cell for an automobile.

[0002]

2. Description of the Related Art FIG. 2 is a flow chart showing an example of a conventional automobile fuel cell. In this example, methanol or gasoline is used as the fuel. That is, after the methanol supplied from the fuel tank 10 is mixed with water in the fuel preheater 11, it is reformed into a reformed gas containing hydrogen in the reforming heat exchanger 12 and supplied to the anode side of the fuel cell 14. To be done. The supercharged air from the supercharger 15 is supplied to the cathode side of the fuel cell 14 via the supply air intercooler 16 and the humidifier 17.

Exhaust gas 1 containing water vapor is discharged from the cathode side of the fuel cell 14, which is recovered as water by the condenser 2 and supplied to the water supply section of the system for reuse. That is, the recovered water is supplied to the humidifier 17 on the air side and / or the humidifier 13 on the hydrogen side and the fuel preheater 11. The cooling water (LLC) cooled by the radiator 7 is supplied to the condenser 2, the supply air intercooler 16, the fuel preheater 11, the reforming heat exchanger 12,
The heat is exchanged by being supplied to the primary cooler 18 and the heat sink 19, respectively. Electricity is supplied from the fuel cell 14 to the battery 21 and the motor 22 via the control power unit 20.

The above flow chart uses methanol as a fuel, and in the case of gasoline, the recovered water and gasoline as fuel are vaporized, respectively, and both are mixed after vaporization. Is different. The present invention is directed to any type of fuel cell.

[0005]

The exhaust gas 1 from the fuel cell 14 is such that the water in the exhaust gas is recovered by the condenser 2 and reused for each water supply section of the fuel cell system. However, it is difficult to collect all the water in the exhaust gas 1 by the condenser 2. When collecting more water, the condenser 2 needs to be upsized, which goes against the downsizing of the system. Therefore, an object of the present invention is to provide a water recovery device for a fuel cell in which the condenser 2 is downsized and the water recovery efficiency is improved.

[0006]

According to the present invention as set forth in claim 1, the exhaust gas (1) flowing out from a fuel cell is cooled by a condenser (2) to recover water in the exhaust gas, In the device to be reused for the water supply part of the fuel cell system, the desiccant dehumidifier (3) is provided downstream of the output side of the condenser (2).
Of the desiccant dehumidifier (3) is connected to the adsorption zone (4) of the condenser and the desorption zone (5) of the desiccant dehumidifier (3) is connected to the upstream side of the input side of the condenser (2), and discharged from the outlet side of the condenser (2). The adsorbed water in the exhaust gas (1) is adsorbed to the desiccant in the adsorption zone (4), and the water adsorbed in the desiccant by the hot exhaust gas (1) is removed in the desorption zone (5) to contain the water. The fuel cell water recovery device is characterized in that the exhaust gas is guided to the condenser (2).

The present invention according to claim 2 provides the fuel according to claim 1, wherein an exhaust gas intercooler (6) is provided upstream or downstream of the desorption zone (5) of the desiccant dehumidifier (3). It is a battery water recovery device.

According to a third aspect of the present invention, in the first or second aspect, the condenser (2) has cooling water inside.
A water recovery device for a fuel cell, in which a cooling water passage through which (23) flows and a gas passage through which the exhaust gas (1) flows are arranged separately from each other.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments described below. FIG. 1 is a flow chart showing a main part of a water recovery device for a fuel cell according to the present invention. Figure 1
The condenser 2 in 1 is in principle the same as the condenser 2 in FIG. The exhaust gas 1 from the fuel cell in FIG. 1 passes through the exhaust gas intercooler 6, the desorption zone 5 of the desiccant dehumidifier 3, the gas passage of the condenser 2 and the adsorption zone 4 of the desiccant dehumidifier 3. Further, the cooling water 23 cooled by the radiator 7 is supplied to the condenser 2 and the exhaust gas intercooler 6 to cool the exhaust gas 1 respectively.

In this apparatus, a feature of the present invention is that the adsorption zone 4 of the desiccant dehumidifier 3 is connected downstream of the output side of the condenser 2 and the desorption zone 5 of the desiccant dehumidifier 3 is connected to the condenser. 2 is connected upstream of the input side. The desiccant dehumidifier 3 of this example is of a rotary type, has a circular cross section with a circular outer periphery, and rotates slowly around its axis. The inside is formed in a honeycomb structure as an example, and the desiccant is held therein. Further, the condenser 2 may be of shell-and-tube type or the like. In the case of the shell-and-tube type, the exhaust gas 1 flows in the tube, and the cooling water 23 flows in the shell on the outer circumference of the tube. Then, water is collected in the lower side header and is supplied to each water supply unit of the fuel cell system.

The water that cannot be completely recovered by the condenser 2 passes through the adsorption zone 4 of the desiccant dehumidifier 3 and is adsorbed by the desiccant. Then, the desiccant that has adsorbed the water moves to the desorption zone 5 by the rotation of the desiccant dehumidifier 3, where the hot exhaust gas 1 desorbs the water in the desiccant and supplies it to the condenser 2. The exhaust gas 1 is appropriately cooled to the upstream side of the desiccant dehumidifier 3 by the exhaust gas intercooler 6. As a result, the temperature is adjusted so as not to damage the desiccant of the desiccant dehumidifier 3.

Then, the exhaust gas 1 passes through the desorption zone 5 of the desiccant dehumidifier 3 to remove water in the desiccant, so that the temperature of the exhaust gas 1 itself is lowered. Then,
Moisture in the exhaust gas is easily condensed, and the condensation performance of the condenser 2 is improved. Further, the moisture in the exhaust gas 1 that cannot be recovered by the condenser 2 is adsorbed by the desiccant dehumidifier 3 and is desorbed in the desorption zone 5 to recover as much water as possible by the condenser 2. The vapor exhaust gas 1 may be a combustion gas obtained by mixing the anode exhaust gas of the fuel cell with air or the cathode exhaust gas and burning the mixture.

[0013]

The fuel cell water recovery system of the present invention allows the moisture in the exhaust gas 1 discharged from the outlet side of the condenser 2 to be adsorbed by the desiccant in the adsorption zone 4 of the desiccant dehumidifier 3 and at a high temperature. The moisture adsorbed on the desiccant by the exhaust gas 1 of the desiccant 3 is removed by the desorption zone 5 of the desiccant dehumidifier 3.
The exhaust gas containing the water is introduced into the condenser 2 so as to have the following effects. (1) Moisture in the exhaust gas 1 that could not be recovered by the condenser 2 can be recovered via the desiccant dehumidifier 3. (2) Passing the hot exhaust gas 1 through the desorption zone 5 of the desiccant dehumidifier 3 and absorbing the water adsorbed by the desiccant into the exhaust gas 1 to lower the temperature of the exhaust gas 1 itself and reduce the water content in the exhaust gas. By increasing the ratio, the water recovery efficiency in the condenser 2 can be increased. If the water recovery efficiency is the same as the conventional one, the capacity of the condenser 2 can be reduced and the entire system can be made compact.

[Brief description of drawings]

FIG. 1 is a flow chart of a water recovery device for a fuel cell according to the present invention.

FIG. 2 is a flow chart showing an example of a conventional fuel cell.

[Explanation of symbols]

1 exhaust gas 2 condenser 3 desiccant dehumidifier 4 Adsorption zone 5 Desorption zone 6 Intercooler for exhaust gas 7 radiator 8 fans 10 fuel tank 11 Fuel preheater 12 Reforming heat exchanger 13 Humidifier 14 Fuel cell 15 supercharger 16 Intercooler for supply air 17 Humidifier 18 Primary cooler 19 heat sink 20 Control power unit 21 battery 22 motor 23 Cooling water

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Atsushi Okubo             3-25-3 Yoyogi, Shibuya-ku, Tokyo Toyo             Inside Radiator Co., Ltd. (72) Inventor Takeshi Kuwahara             3-25-3 Yoyogi, Shibuya-ku, Tokyo Toyo             Inside Radiator Co., Ltd. (72) Inventor Souji Tanaka             3-25-3 Yoyogi, Shibuya-ku, Tokyo Toyo             Inside Radiator Co., Ltd. F-term (reference) 5H027 AA02 BA01 DD00

Claims (3)

[Claims] 1. A device for cooling exhaust gas (1) flowing out from a fuel cell by a condenser (2), recovering water in the exhaust gas, and reusing it in a water supply section of the fuel cell system. , The adsorption zone (4) of the desiccant dehumidifier (3) is connected downstream of the output side of the condenser (2), and the desorption zone (5) of the desiccant dehumidifier (3) is connected to the condenser (2). The water in the exhaust gas (1) discharged from the outlet side of the condenser (2), which is connected to the upstream side of the input side, is adsorbed by the desiccant in the adsorption zone (4) and the high temperature exhaust gas (1) A water recovery device for a fuel cell, characterized in that the water adsorbed on the desiccant is removed in the desorption zone (5), and the exhaust gas containing the water is guided to the condenser (2). 2. The water recovery device for a fuel cell according to claim 1, wherein an exhaust gas intercooler (6) is provided upstream or downstream of the desorption zone (5) of the desiccant dehumidifier (3). 3. The condenser (2) according to claim 1 or 2, wherein a cooling water passage through which cooling water (23) flows and a gas passage through which the exhaust gas (1) flows are separated from each other. Water recovery device for fuel cells.