JPH08306380A - Stacked fuel cell - Google Patents

Abstract

(57) [Summary] [Purpose] It shall be possible to accurately control the cell temperature with low power consumption when operation is stopped. A manifold mounting plate 6A for mounting a manifold 7 on both ends of a fuel cell stack formed by stacking cells 9 with a cooling plate 8, a current collector plate 4 for extracting generated power, an insulating plate 3 and a heat insulating plate. 2A and 2B are arranged, and in a laminated fuel cell configured by tightening with a tightening plate 1,
A heater 10A is embedded in a manifold mounting plate 6A adjacent in the stacking direction of the fuel cell stack, and when the operation is stopped, electricity is supplied to heat and keep the cells 9 at a predetermined temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated fuel cell for supplying a reaction gas to a fuel cell laminated body to obtain electric power, and more particularly to a heat retaining structure when the operation is stopped.

[0002]

2. Description of the Related Art FIG. 4 is a longitudinal sectional view showing the basic structure of a conventional laminated fuel cell of this type. The cell 9 is formed by laminating a plurality of rectangular unit cells each having an electrolyte layer sandwiched between an oxidant electrode and a fuel electrode. The cooling plate 8 that is alternately stacked with the cells 9 to form a fuel cell stack serves to cool the cells 9 by removing heat generated due to power generation by flowing a coolant through an embedded cooling pipe. Plays. A manifold 7 is arranged on each side surface of the fuel cell stack, and is airtightly mounted on a carbon-based manifold mounting plate 6 arranged on both end surfaces of the fuel cell stack in the stacking direction. A current collector plate 4 is incorporated on the outside of the manifold mounting plate 6 via a graphite 5. Further, a tightening plate 1 for tightening and holding these laminated bodies, and an insulating plate 3 for maintaining electric insulation. And the heat insulating plates 2A and 2B for suppressing the temperature rise are arranged therebetween.

In this configuration, when the manifold 7 is used to flow the oxidant gas from one side surface of one set of the fuel cell stack to the other side, and to flow the fuel gas from one side surface of the other set to the other side, An electrochemical reaction occurs in each of the cells 9 and a direct current power is generated between the pair of current collector plates 4, so that the lead wires 11 connected to the current collector plates 4 extract the cells to the outside.

Since the electrochemical reaction is an exothermic reaction, cooling is carried out by passing a refrigerant through the cooling pipe embedded in the cooling plate 8 as described above, and the fuel cell stack is maintained at a predetermined temperature for operation. To be done. When the operation is stopped, the heat generation is stopped and the temperature of the fuel cell stack is lowered. However, when the temperature is too low, the electrolyte layer of the cell 9 may become abnormal. Also, a method of keeping the temperature above a predetermined temperature is adopted. The heaters 10 attached to the tightening plates 1 at both ends in the stacking direction in FIG. 4 are used for this purpose, and are turned on when the operation is stopped, and the cells 9 are heated by conduction heat to maintain the cells at a predetermined temperature.

[0005]

As described above, in the conventional laminated fuel cell, the cell temperature is kept above the predetermined temperature even when the operation is stopped by heating with the heater 10 attached to the tightening plate 1. The method of doing is adopted. However, in this method, the heaters 10 for heating are arranged on the fastening plates 1 on both end surfaces of the laminated fuel cell, and the heat insulating plate 2A is provided between the heater 10 and the cells 9 of the fuel cell laminated body whose temperature is to be controlled. Since the insulating plate 3, the heat insulating plate 2B, the current collecting plate 4, and the manifold mounting plate 6 are interposed, there is a drawback that the performance is poor. That is, among the above, the heat insulating plate 2A, the insulating plate 3 and the heat insulating plate 2B, in particular, have low heat transfer performance, so that there is a control delay between the temperature of the heater 10 and the temperature of the cell 9 so that proper control cannot be performed. There are points,
Further, since the heater 10 is arranged on the outermost side, the heating efficiency is poor and a large amount of heating power is required.

The present invention has been made in view of the above problems, and an object thereof is to provide a laminated fuel cell capable of accurately controlling and maintaining the cell temperature with a small power consumption when the operation is stopped. It is in.

[0007]

In order to achieve the above object, in the present invention, a fuel cell stack formed by stacking electrode cells with a cooling plate interposed, and both end faces in the stacking direction. A manifold mounting plate, a current collecting plate, an insulating plate, and a tightening plate, which are sequentially stacked on the fuel cell stack, and a manifold which is arranged on the side surface of the fuel cell stack and airtightly mounted on the manifold mounting plate. In a laminated fuel cell in which agent gas and fuel gas are made to flow and DC power is taken out from a current collector plate, for example, a heater is embedded in a manifold mounting plate to form a heat retaining means, and a space is provided between the fuel cell stack and the current collector plate. In addition, the battery heat insulating means is provided.

[0008]

As described above, if the battery heat retaining means is provided between the fuel cell stack of the laminated fuel cell and the current collector, the fuel cell stack is heated by using this battery heat retaining means when the operation is stopped. In this case, since the cell heat retaining means and the fuel cell stack are close to each other and there is no insulating plate or heat insulator having poor heat transfer performance therebetween, good heat transfer performance can be obtained, so that the fluctuation range with excellent responsiveness can be obtained. A small temperature control is possible.
Further, since the battery heat retaining means is arranged inside the laminated portion unlike the conventional case, it can be effectively heated without being directly radiated to the outside, and the required power consumption is small.

In particular, if a heater is embedded in the manifold mounting plate to serve as the cell heat retaining means, the cell heat retaining means is arranged adjacent to the fuel cell stack, so that extremely excellent temperature control can be performed and consumption can be improved. The power consumption is also extremely small.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 1A and 1B are explanatory views of an embodiment of a laminated fuel cell according to the present invention. FIG. 1A is a vertical sectional view showing a basic structure, and FIG. 1B is a perspective view of an incorporated manifold mounting plate. FIG.
In (a), components having the same functions as those of the conventional stacked fuel cell shown in FIG. 4 are designated by the same reference numerals, and duplicate description will be omitted.

The difference between this embodiment and the conventional example lies in the arrangement of the heaters used for keeping the temperature when the laminated fuel cell is stopped. In the conventional example, the heaters are attached to the outer surfaces of the fastening plates 1 at both ends. On the other hand, in the present embodiment, it is incorporated in the manifold mounting plate 6A, and as shown in FIG. 1 (b), it is provided in the manifold mounting plate 6A in the horizontal direction so as to be biased toward the collector plate 4 side. A heater 10A is arranged in the lateral hole to form a battery heat retaining means.

As in this configuration, the manifold mounting plate 6
If the heater 10A is incorporated in A and is used for keeping heat when the operation is stopped, since the manifold mounting plate 6A is directly adjacent to the fuel cell stack, it is hindered by an insulating plate or a heat insulating plate which is interposed as in the conventional case. It is possible to effectively heat the cell 9 and keep it warm. 2 and 3 are perspective views showing another embodiment of a method of incorporating a heater into a manifold mounting plate in the laminated fuel cell of the present invention.

In the embodiment shown in FIG. 2, a groove is provided in the surface of the manifold mounting plate 6B on the side of the current collector plate 4, and the heater 10
B is arranged to constitute a battery heat insulation means, and FIG.
In this embodiment, a groove is provided on the surface of the manifold mounting plate 6C on the side of the current collector plate 4 and the heater 10C is arranged, and then the manifold mounting plate 6D is arranged on the upper part of the groove to sandwich the heater 10C and keep the battery warm. Constitutes a means.

[0014]

As described above, according to the present invention, the fuel cell stack is formed by stacking the electrode cells with the cooling plate interposed, and the manifold mounting is sequentially stacked on both end faces in the stacking direction. A plate, a collector plate, an insulating plate and a tightening plate,
A stack type fuel cell including a manifold arranged on a side surface of a fuel cell stack and airtightly mounted on a manifold mounting plate, and using the manifold to flow an oxidant gas and a fuel gas into an electrode cell to extract DC power from a current collector plate. At
For example, since the heater is embedded in the manifold mounting plate to form the heat retaining means, the battery heat retaining means is provided between the fuel cell stack and the current collector plate. It has become possible to obtain a laminated fuel cell that is precisely controlled and held.

[Brief description of drawings]

FIG. 1 is an explanatory view of an embodiment of a laminated fuel cell of the present invention,
(A) is a vertical cross-sectional view showing the basic configuration, and (b) is a perspective view of an incorporated manifold mounting plate.

FIG. 2 is a perspective view showing a second embodiment of the configuration of the manifold mounting plate in the laminated fuel cell of the present invention.

FIG. 3 is a perspective view showing a third embodiment of the configuration of the manifold mounting plate in the laminated fuel cell of the present invention.

FIG. 4 is a vertical cross-sectional view showing the basic structure of a conventional laminated fuel cell of this type.

[Explanation of symbols]

 1 Tightening plate 2A, 2B Heat insulating plate 3 Insulating plate 4 Current collecting plate 6, 6A Manifold mounting plate 6B, 6C Manifold mounting plate 7 Manifold 8 Cooling plate 9 Cell 10, 10A Heater 10B, 10C Heater

Claims (2)

[Claims] 1. A fuel cell stack comprising a fuel cell stack formed by stacking electrode cells formed by stacking single cells sandwiching an electrolyte layer between an oxidizer electrode and a fuel electrode with a cooling plate interposed therebetween, and a fuel cell stack. A manifold mounting plate, a current collector plate, an insulating plate, and a tightening plate, which are sequentially stacked on both end faces in the stacking direction of the fuel cell, and a manifold arranged on the side surface of the fuel cell stack and airtightly mounted on the manifold mounting plate. A laminated fuel cell in which an oxidant gas and a fuel gas are passed through an electrode cell to extract DC power from a current collector plate, characterized by having a battery heat insulating means between the fuel cell stack and the current collector plate. Stacked fuel cell. 2. The stacked fuel cell according to claim 1, wherein the cell heat retaining means is formed by embedding a heater in a manifold mounting plate.