JPH0656770B2 - Fuel cell power generation system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a portable small fuel cell power generation system.

(B) Conventional technology A methanol reformer, which has a simple structure and is compact, is suitable as a reformer used for a small fuel cell, and vaporizes and reforms a mixed liquid of methanol and water to generate a fuel gas.
Since the temperature of the produced gas is 200 to 250 ° C., it is necessary to lower the temperature to an appropriate temperature with a heat exchanger when supplying it to the battery. However, in the case of a small system, using a heat exchanger is not only uneconomical because there is a space limitation and the amount of gas is small so that the amount of heat recovered is small and the capacity and weight of the system are increased. It was

(C) Problems to be Solved by the Invention This invention reduces the temperature of the reformed gas supplied to the cell as fuel gas without using a separate heat exchanger as in the conventional case, and simplifies the system. , For compactness.

(D) Means for Solving Problems The present invention has an inlet / outlet manifold for cooling air mounted on one opposing surface of a battery stack, and an exhaust damper, an outside air intake damper and a blower are sequentially provided between these outlet / inlet manifolds. Inlet and outlet manifolds for fuel gas reformed with methanol and reaction air are installed in parallel on the other side of the cell stack connected by a circulation duct, and heat exchange is performed on the back side of the inlet manifold for the reaction air or cooling air. An expansion passage chamber forming a part of the fuel gas introduction passage is formed via a partition wall.

(E) Operation In the present invention, the high temperature fuel gas reformed by the methanol reformer is cooled by the reaction air or the cooling air while flowing through the expansion passage chamber formed on the rear surface of the inlet manifold of the reaction air or the cooling air. And is supplied to the battery at an appropriate temperature.

(F) Example In the battery stack (1), a plurality of unit cells (2) and gas separation plates (3) are alternately stacked as shown in FIG.
The upper and lower end plates (5) are clamped in the stacking direction with (4) interposed. This battery stack (1) is a system in which reaction air and cooling air are separately supplied, and one opposing peripheral surface of the battery stack (1) is provided with a cooling air flow surface (cooling air channel (6) of the cooling plate (4). Open) and the other facing surfaces are the reaction air and fuel gas flow surfaces (reaction air channel (7) of the gas separation plate (3)).
And the fuel gas channel (8) opens respectively. ] It is divided into two.

The cooling air inlet / outlet manifolds (9) (9) ′ and the reaction air / fuel gas inlet / outlet manifolds (10) (10) ′ and (11) (11) ′ are provided corresponding to each of these flow surfaces. Each is installed.
A circulation duct (15) having an exhaust damper (12), an outside air intake damper (13) and a blower (14) is connected between the cooling air outlet manifold (9) ′ and the inlet manifold (9).

The fuel gas is hydrogen-rich gas obtained by vaporizing and reforming a mixed liquid of methanol and water with a reformer (16).

In each of the embodiments shown in FIGS. 2 and 3, the reaction gas inlet manifold (10) has a heat exchange partition wall (17) on the back surface thereof to form a part of the fuel gas introduction passage (18). Open passage room (18) ′
In the other embodiment shown in FIG. 5, a fuel gas expansion passage chamber (18) 'is formed on the back surface of the cooling air inlet manifold (9) as in the previous embodiment.

As for the reaction air, in the case of the embodiment shown in FIG. 2, the outside air is introduced into the reaction air inlet manifold (10) by the supply blower (19), whereas in the case of the embodiment shown in FIG. 3 and FIG. 4, it is the downstream side of the circulation blower (14). Further, a part of the cooling air is introduced into the reaction air manifold (10) through the branch pipe (20).

Battery stack that heats up due to reaction heat during battery operation (1)
Is cooled by circulating cooling air and maintained at a specified temperature of about 190 ° C. The cooling air introduced from the inlet manifold (9) removes heat of reaction while flowing through each cooling channel (6), the temperature is raised to about 180 ° C, and the cooling air drawn out from the outlet manifold (9) 'is Part of it is discharged from the exhaust damper (12) to the outside of the system, and at the same time, the other part of
The inlet manifold is reintroduced together with the cold outside air taken in from (13).
Introduced in (9). This inlet side cooling air temperature is about 120
The discharge amount and the intake amount are adjusted by the dampers (12) and (13) in accordance with the outside air temperature so as to be ˜130 ° C.

The temperature of the fuel gas produced by the refoma (16) is about 200-
Although the temperature is 250 ° C., heat is exchanged with the reaction air or the cooling air while flowing through the expansion passage chamber (18) ′ formed on the back surface of the reaction air inlet manifold (10) or the cooling air inlet manifold (9). The temperature of the inlet of the fuel gas to the manifold (11) decreases, and at the same time, the temperature of the reaction air in the inlet manifold (10) or the cooling air in the inlet manifold (9) rises.

The flow rates of the fuel gas and the reaction air are about 1: 5, and the flow rates of the fuel gas and the cooling air are about 1:20. Therefore, in the case of the embodiment shown in FIG. At the same time as the temperature of the reaction air rises to about 130 ° C, the fuel gas drops to about 130 ° C and is supplied to the cell stack (1). On the other hand, in the embodiment shown in FIG. 3, the cooling air (about 120 ° C.) on the downstream side of the circulation blower (14) is sent to the reaction air inlet manifold (10), so that the reaction air is heated to about 160 ° C. Decrease to about 170 ° C and are supplied to the battery stacks, respectively. Therefore, the method of FIG. 2 is more suitable for the method of exchanging heat between the reaction air and the fuel gas.

On the other hand, in the case of the other embodiment shown in FIG. 5, heat exchange is performed between the cooling air and the fuel gas, which flow rate is larger than that of the reaction air.
The fuel gas is cooled by cooling air at about 120 ° C,
At the same time as the temperature drops to 0 ° C., the cooling air rises to about 130 ° C. and is supplied to the battery stack (1). In this case, it is preferable to supply cooling air in a branched manner as the reaction air.

(G) Effect of the Invention According to the present invention, the high temperature fuel gas generated by the reformer reacts with the reaction air or the reaction air while passing through the expansion passage chamber formed through the heat exchange partition wall on the rear surface of the manifold of the cooling air. Since the heat is exchanged with the cooling air and the temperature is cooled to a temperature suitable for supplying to the battery, the system can be simplified and made compact without requiring a separate heat exchanger.

[Brief description of drawings]

FIG. 1 is a perspective view of a battery stack of a cooling air separation system, FIGS. 2 and 3 are flow charts of a power generation system according to an embodiment of the present invention, and FIG. 4 is a schematic view of the system of FIGS. 5 is a flow chart of a power generation system according to another embodiment, and FIG. 6 is a perspective view of a main part of the system shown in FIG. (1): Battery stack, (9), (9) ': Cooling air inlet / outlet manifolds, (10), (10)': Reaction air inlet / outlet manifolds, (11), (11) ′: Fuel gas inlet / outlet manifolds, (12): Exhaust damper, (13): Outside air intake damper, (14): Circulating blower, (16): Refoma, (17): Heat exchange bulkhead, (18) ′: Fuel gas expansion passage chamber

Claims (3)

[Claims] 1. A cooling air inlet / outlet manifold is attached to one opposing peripheral surface of a battery stack, and these outlet / inlet manifolds are sequentially connected by a circulation duct having an exhaust damper, an outside air intake damper and a blower, and the battery is connected to the battery stack. On the other facing surface of the stack, the inlet and outlet manifolds of the fuel gas and reaction air reformed from methanol are arranged in parallel, and on the rear surface of the inlet manifold of the reaction air or the cooling air, through a heat exchange partition wall, A fuel cell power generation system characterized in that an expansion passage chamber forming a part of a fuel gas introduction passage is formed. 2. The fuel cell power generation according to claim 1, wherein outside air is directly introduced into the reaction air inlet manifold when the expansion passage chamber is formed on the rear surface thereof. system 3. The cooling air is branched into the reaction air inlet manifold from the downstream side of the blower when the expansion passage chamber is formed on the back surface of the cooling air inlet manifold. A fuel cell power generation system according to claim 1.