JPH01209671A - Fuel cell of molten carbonate type - Google Patents

Abstract

PURPOSE:To improve electricity generating efficiency by applying a uniform pressure on a laminated body by using the tightening force of the laminated body and a gas pressure. CONSTITUTION:A fuel cell laminated body 10 is sealed in a pressure vessel 11, an expansion-contraction bellows 12 is disposed between the top surface of the fuel cell laminated body 10 and the wall of the pressure vessel 11, and a pressure higher than the gas pressure in the pressure vessel 11 is applied in the bellows 12. As a result, it becomes possible not only to apply a uniform pressure on the surface of the laminated body 10 but also to apply any required pressure at will to the laminated body 10 by controlling only the gas pressure without being affeted by the height of the laminated body 10 in operation. This makes it possible to secure excellent contact between cells and to improve electricity generating efficiency.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to improvements in molten carbonate fuel cells.

(Prior Art) A conventional fused carbonate fuel cell has a structure shown in FIG. The basic structure is a stacked body 10 in which a large number of cells 1 and cooling plates 2, which are the basic elements of the power generating body, are stacked together. This laminate 10
A heat insulator 6 is placed on top and bottom of the. Furthermore, a compressive force is applied to such a structure in the axial direction by a laminated body axial direction tightening member 7, a tightening rod 8, and an adjustment spring 9. A cover-shaped manifold 4 is pressed against the side surface of the stacked body io by a manifold tightening spring 5 in order to evenly distribute fuel and distribution agent to each cell.

(Problems to be Solved by the Invention) In order to obtain electricity efficiently, it is necessary to ensure a sufficient contact area over the entire laminate, and it is necessary to apply uniform pressure within the surface of the laminate. It is also necessary to absorb changes in the height of the stack that occur during operation and to ensure good contact between cells. In the conventional structure, the tightening force was applied by the tightening bar 7 and the tightening rod 8, but it is difficult to apply a uniform tightening force with such a method of tightening via a plurality of irons. There is also a problem in keeping the pressure constant even when the height of the stack changes during operation.

Therefore, the present invention uses gas pressure as a tightening force for the laminate to apply uniform pressure to the laminate.
The purpose of the present invention is to provide a molten carbonate fuel cell that can improve power generation efficiency.

[Structure of the invention]

Means for Analyzing Problem 1) In the molten carbonate fuel cell of the present invention, the fuel cell stack is sealed in a pressure vessel, and an expandable bellows is provided between the top surface of the fuel cell stack and the wall of the pressure vessel. By applying gas pressure inside the bellows that is higher than the gas pressure inside the pressure vessel, the structure is such that a uniform tightening force can be applied to the fuel cell stack.

(Function) In the structure configured as described above, since gas pressure acts directly as a tightening force on the fuel cell stack, uniform pressure can be applied within the surface of the stack. Furthermore, since the extensible bellows are used, it is possible to apply any pressure to the stack by controlling only the gas pressure without being affected by changes in the height of the stack during operation.

(Example) The present invention will be described below based on embodiments shown in the drawings.

FIG. 1 shows a molten carbonate fuel cell according to the present invention. The basic structure in which a fuel cell stack 10 is constituted by cells 1 and cooling plates 2 and a manifold A is attached to the side surface is the same as the conventional structure. This fuel cell stack 10 is sealed within a pressure vessel 11, and an expandable bellows 12 is provided between the top surface and the wall of the pressure vessel. The structure allows gas pressure to be applied independently to the inside of the pressure vessel and the inside of the bellows.

〔Effect of the invention〕

In the molten carbonate fuel cell according to the present invention, gas pressure is used as the clamping force for the fuel cell stack, so uniform pressure can be applied within the plane of the stack, ensuring good cell-to-cell contact. This improves the power generation efficiency of the fuel cell. Furthermore, changes in the height of the laminate that occur during operation can be absorbed by the expandable bellows, and the tightening force can be arbitrarily controlled by controlling only the pressure.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a molten carbonate fuel cell showing an embodiment of the present invention, and FIG. 2 is a partially cutaway perspective view of a molten carbonate fuel cell showing a conventional example. 1... Cell, 2... Cooling plate, 4... Manifold, 5... Manifold tightening spring, 6... Insulator, 7... Tightening bar, 8... Tightening rod ,9...
Adjustment spring, 10... Fuel cell stack, 11.
...Pressure vessel, 12...Extendable bellows. Agent Patent Attorney Nori Chika Weight Mitsuyuki Matsuyama Figure 1

Claims (1)

[Claims] In a device in which a telescopic bellows is provided between an end face of a fuel cell stack and a wall of a pressure vessel accommodating the fuel cell stack, the gas pressure applied to the telescopic bellows is made higher than the gas pressure in the pressure vessel; A molten carbonate fuel cell characterized in that it is configured to apply uniform pressure within the plane of a fuel cell stack due to the differential pressure generated.