JPS61133577A - Fuel cell - Google Patents

Abstract

PURPOSE:To obtain a low cost, compact fuel cell whose transportation is easy, exchange and connection of a unit are easy by connecting a plurality of units each of which comprises a tank, a cell stack and a reaction gas duct to form a fuel cell. CONSTITUTION:A cell stack 9 obtained by stacking unit cells in a square pole is accommodated in a lateral type cylindrical tank 23. Connecting pipes 24 such as reaction gas supply and discharge pipes or cooling water supply and discharge pipes are connected to manifolds 10 of four sides of the cell stack 9. The cell stack 9 is fixed through a base 26 and a vibration preventer 27 in the lateral type cylindrical tank 23. A plurality of unit cells are fixed with bolts 29 of flanges 23c and one end of end units is sealed with blind covers. The other end is connected to a fuel cell control system through connecting fittings 32 of a cover 31b to form a fuel cell power generating system. Thereby, increase in unit capacity is made possible and costs of transportation and manufacturing are decreased. Moreover, check on troubles is easy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a fuel cell in which a cell stack housed in a tank constitutes one unit, and a plurality of these units are connected.

Technical Background of the Invention] A fuel cell is a device that oxidizes the chemical energy of fuel through an electrochemical process, thereby directly converting the energy released as a result of the oxidation reaction into electrical energy. Power generation plants using fuel cells are expected to achieve a thermal efficiency of 40 to 50% even on a relatively small scale, far exceeding new thermal power plants. Furthermore, SOx is a pollution factor that has become a major social problem in recent years.

In principle, high energy conversion efficiency can be expected due to extremely low NOx emissions, no combustion cycle is included in the power generation equipment, so large amounts of cooling water are not required, and vibration noise is small. Because it has few problems and has good responsiveness to load fluctuations, there are expectations and interest in research into its development and practical application.

Another feature of this battery power generation system is that it can be modularized, so the construction period is short. Furthermore, the exhaust heat temperature of the combustion battery is within the range that can be used as a heat source for hot water supply, etc., and it is highly efficient, making it possible to create a heat supply power generation system, so it can be used as a large-scale power generation system to partially replace thermal power generation in the future. There is also a lot of interest in the 11 Samurai.

A small-scale fuel cell power generation plant of this type has already been prototyped and is in the stage of experimental operation. but,
The biggest technical problem in the practical application of large-capacity fuel cell power generation plants is the increase in individual fuel cell capacity due to the increase in unit capacity. [By miniaturizing batteries and efficiently arranging a large number of fuel cells to support their limited lifespan of several years, maintenance and replacement are easy, and the installation space is reduced. It depends on how efficient the connection system of the various pipes in the fuel gas cooling system can be.

The third section is a cross-sectional model diagram showing the principle of such a fuel cell.
Shown in the figure. That is, a single cell is formed by interposing an electrolyte layer 2 impregnated with an electrolytic solution such as phosphoric acid between the - set of porous electrodes 1, and hydrogen gas H and air A are placed on both end surfaces of the single cell. is supplied continuously.

In this way, reaction products and reaction residues are continuously removed to the outside, so power generation can be continued for a long period of time.

The basic structure of such a combustion battery is the 74th
As shown in the figure. That is, the electrolyte matrix.

) A positive electrode and a negative electrode 5 are arranged on both sides of the base layer 3 to form a square plate-shaped unit cell, and in order to use this unit cell as a power generation device, a large number of unit cells are connected in series. An ink connector 6 having a groove for supplying gas is disposed between these single cells.
The cells are stacked alternately with the single cells. This grooved interconnector 6 is provided with a plurality of grooves that open on two opposite side edges, and a hydrogen gas flow path 7 that uses the groove on the - side as a flow path and a hydrogen gas flow path that uses the groove on the other side as a flow path. The air flow paths 8 are arranged in directions perpendicular to each other.

By the way, in the fuel cell N currently under development, as shown in FIG. A manifold 10 for supplying reaction gas is attached to the side surface of the reactor. A hydrogen gas supply pipe 11, a hydrogen gas discharge pipe 12, an air supply pipe 13, and an air discharge pipe 14 are connected to this manifold 10, respectively, and the hydrogen gas and air are passed through the cell stack 9 in the direction of arrows A and B. It is designed to flow in the same direction. Further, although a higher operating temperature of the cell stack 9 is preferable in terms of reaction theory, it is desirable to maintain it at around 200'C due to constraints such as the heat resistance of the constituent materials 1 and the vapor pressure of the electrolyte.

Therefore, cooling water is circulated in a conduit buried in the cell stack 9 to cool the heating during startup of the combustible battery and the heat generated during operation. That is, in this type of fuel cell, as shown in FIG. Furthermore, the output of the fuel cell is direct current, which is supplied from the power terminal (positive electrode) 17 and the power terminal (negative electrode) 18 disposed at the upper and lower ends of the cell stack 9 via one connecting conductor and the bushing 20. and is pulled out of the tank 21.

The contents of the fuel cell as described above are stored in a tank 21, and nitrogen gas or the like is sealed in the tank 21 to suppress leakage of reaction gas from the manifold 10 and its parts. In order to maintain the cell stack 9 at an appropriate temperature and to effectively utilize the heat generated during operation through cooling pipes without dissipating it to the outside, a tank 21 is installed.
A heat insulating material 22 is attached to the inner surface of the housing.

[Problems with Background Art] Incidentally, in the fuel cells shown in FIGS. 5(A) and 5(B), the unit capacity (A) is proportional to the unit cell area and the number of stacked units. However, the porous electrode plates that make up the cell are
There are manufacturing constraints such as molding to a uniform thickness on the entire surface, constraints on lamination work due to the brittle material, and further constraints such as difficulty in obtaining uniform tightening force on the entire surface. It is difficult to increase the number of cell stacks, and there is a limit to the number of single cells stacked due to transportation constraints or stacking work constraints, so the capacity per 1ζ cell stack is 200 ~
It is suppressed to 500kw. Therefore, in order to put a large-capacity fuel cell power generation plant into practical use, it is necessary to install several tens or hundreds of fuel cells (7).

However, in conventional fuel cells, the area of the single cells that make up the cell stack is made as large as possible, and the number of stacked cells is increased to increase the capacity to 119. The cell stack was housed in a single tank with a capacity that matched the external shape of the cell stack. A large-capacity power generation device was obtained by connecting a plurality of such individual combustion cells via bushings drawn out from the tank.

For this reason, in conventional combustible batteries, each cell stack is housed in an independent tank, and there are many pipes for cooling water and reactant gas connecting each tank, making the overall structure of the device multi-Wlt and increasing the installation space. This has the disadvantage that it also makes inspection and maintenance work difficult. In particular, fuel cells are said to have a lifespan of several years, and one of the many
In the event of a problem, it is often necessary to replace parts of the unit in units of units, and in that case, the connection points are extremely complicated and take a lot of time. Therefore, when tens or hundreds of these are installed side by side, the construction cost of the entire power generation system will be greatly affected.

[Purpose of the Invention] The present invention was proposed in order to solve the above drawbacks, and its purpose is to integrate a fuel cell consisting of a tank, a cell stack, and a reactant gas duct or cooling water pipe connecting the two into one. By connecting multiple units at the same time as Unit 1-, transportation is easy, the installation space on site is small, and a large number of units can be installed on site (51). It is an object of the present invention to provide an inexpensive and compact fuel cell that can be easily replaced in response to lifespan and troubles, and has low transport and manufacturing costs.

[Summary of the Invention] The fuel cell of the present invention includes a cell stack housed in one horizontal cylindrical tank, and a reactant gas supply/discharge duct arranged in the tank or a manifold arranged on four sides of the cell stack. The cooling water supply and discharge pipes are connected by connecting pipes, and the flanges at both ends of the tank and the flanges of the reaction gas and cooling water ducts or piping are made into a common integral flange.

With this configuration, one unit of the fuel cell is
This modularized unit l-
By connecting any number of batteries, it is possible to connect various types of piping and tanks at the same time, greatly increasing the capacity of a unit group and reducing the number of batteries, while also reducing the number of batteries per unit. It is easy to replace and connect, and it is easy to reassemble and take out and adjust.

[Embodiment of the Invention] Next, an embodiment of the present invention will be specifically described based on FIGS. 1 and 2. Note that the same members as those of the conventional type shown in FIGS. 3 to 5 are designated by the same reference numerals, and the explanation thereof will be omitted.

In FIG. 1, a cell stack 9 formed by layering unit cells in a rectangular column shape is housed in a horizontal cylindrical tank 23.

A manifold 1o for supplying or discharging a reactant gas is arranged on the four sides of the cell stack 9, and a connecting pipe 24 such as a reactant gas supply/discharge pipe or a cooling water supply/discharge pipe is connected to each manifold 10. There is. On the other hand, the horizontal cylindrical tank 23 has a horizontal cylindrical body 23a and a duct 23b for supplying or discharging reaction gas using a part of the body.
and a flange 23c having an independent opening hole for common connection with the body 23a1 ducts 1 to 23b and the connecting main pipe 25 for supplying and discharging cooling water.

The cell stack 9 is inserted through the side opening of the tank 23 and connected to the duct 23b and the connecting main pipe 25 through the connecting pipe 24. Through the sway rest 27 provided in the second part of the cell stack and the base 26,
It is fixed to a horizontal cylindrical tank 23. cell stack 9
A heat insulating material 28 is attached to the outer surface of the tank 23 to keep it warm.

In the fuel cell 31 of the present invention configured in this way, one unit of fuel cell is connected to the bolt 29 of the flange 23c.
At the same time, a plurality of units (4 units 1 to 1 in the figure) are fastened together and placed on the foundation using supporting hardware 30, and a blind cover 31a is attached at one end of both end units 1-, and a blank cover 31a is attached to the narrow end unit side. It is constructed by tightly fitting a lid 29b having various connecting pipe joints 32. By connecting to another fuel cell group or a fuel cell control system via various connecting pipe fittings 32 of this lid 29b, a combustion cell power generation equipment is constructed.

According to the above configuration, when the tank 23 is intended for trailer transportation, for example, the outer diameter of the seven flange 23b can be increased to about 3.3 m considering the transportation limit and height restriction. The inner diameter of the body 23a is approximately 3 m. On the other hand, the dimension of one side of the rectangular prism of the cell stack 9 is approximately 0.6 to 0.6 mm due to various constraints such as the production and lamination work of the porous electrode plates that constitute the cells, and the need for uniform tightening. It will be about 1m. Therefore, the cell stack height is within the inner diameter dimension of the tank body 23a,
It can be as large as about 2 to 2.5 m. When the cell stack 9 is housed in a conventional vertical cylindrical tank, the stacking height of the cell stack 9 can be approximately 2.5 to 3 m due to the relationship between the ground clearance limit dimension and the trailer loading platform height. In fuel cells, the stacking height is slightly lower than in the past, and the cell stack unit capacity also decreases in proportion to the height. However, the length of the connected tanks 23 can be several meters due to trailer limitations, and each unit consisting of cell stacks stored in the tank 23 is installed in close proximity, so the number of units is There will be about 4 to 6 pieces.

On the other hand, since the square columnar cell stack 9 is housed in the horizontal cylindrical tank 23, the space at the lower end of the cell stack 9 can be adjusted depending on the number of stacked cells, but the space between the side of the manifold 10 and the tank 21 is adjustable. Since the space between the two units is reliably created, it is possible to easily secure a large cross-sectional area of the reaction gas supply and discharge duct 23b by using this side space. When supplying gas from the unit in bulk,
The gas is divided sufficiently evenly, resulting in an appropriate gas supply. Furthermore, since the sides have a large opening when each unit is assembled, the connection pipe 2/I between the manifold 10 and the duct 23b can be easily connected, and the connection structure can be simplified. Additionally, the upper and lower supports of the cell stack can be securely fixed. Furthermore, if the cell stack 9 is made to be of a scale that can be transported by trailer according to the method of the present invention, the maximum number of stacked cells will be about 300 cells, and if these are further connected into multiple units, manufacturing variations in the cells will be reduced. It is quite conceivable that some units may have poor characteristics due to this, resulting in a shortened lifespan, but in that case, each unit can be easily separated and replaced with another unit. In other words, since the gas piping system is connected all at once at the flange 23c, it can be replaced in a short time, and the number of consecutive units can be reduced and connected without having to remove the defective unit 1 and insert a replacement unit. They are highly responsive to problems, such as being able to quickly respond to problems. Since it can be modularized as a single unit in this way, it can be used for mass production, and even if each unit has a tank connection flange, there is sufficient loss of 1 to 1.
It is possible to reduce - In this way, in the fuel cell of the present invention, by compactly housing a plurality of cell stacks in the same tank, the single fuel cell capacity M can be increased. Further, the horizontal cylindrical tank can be transported by trailer without disassembling it. Since the shape of the tank itself is horizontal and cylindrical, it is easy to fix during transportation or on-site installation, and the connection and assembly time and installation time can be shortened, and the space required for installation can also be reduced. Furthermore, by assembling one unit at a time, but by combining multiple units, the piping configuration for each unit can be greatly simplified, and the cell stack insulation and piping insulation can be carried out at the same time, making it possible to create a mass production system. It can be made into a rational structure, and the manufacturing cost can be significantly reduced to 1 for transportation cost.

In addition, since a fuel cell is constructed by housing multiple cell stacks in the same cylindrical tank, the unit capacity can be expanded even if the cell stack height is reduced to a certain extent, making it easy to assemble individual cell stacks. Also, since it is easy to install, the quality is stable and the service life is extended.

[Effects of the Invention] As described above, according to the present invention, it is possible to increase the capacity of a single fuel cell unit, reduce the installation space of the equipment, and reduce transportation and! ! This has the effect of reducing production costs and providing a versatile 1'L fuel cell that can last a long time and quickly respond to problems.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an embodiment of the fuel cell of the present invention, and FIG. 2 is a sectional view thereof. Figure 3 is a cross-sectional model diagram showing the principle of a fuel cell, Figure 4 is a perspective view showing the basic configuration of a fuel cell, and Figure 5 (A> shows a schematic configuration of a fuel cell currently under development). The plan view shown in FIG. 5(B) is a longitudinal cross-sectional view thereof. Layer, 4...Positive electrode, 5...Negative electrode, 6...Groove A'' interconnector, 7
...Hydrogen waste flow path, 8...Air flow path, 9...Cell stack, 10...Manibold, 11...Hydrogen gas supply pipe, 12...Hydrogen gas discharge pipe, 13 ... Air supply pipe, 14 ... Air discharge pipe, 15 ... Cooling water supply pipe, 1G ... Cold water discharge pipe, 17 ... Power terminal (
Positive electrode), 18... Power terminal (negative electrode), 19... Connection conductor, 20... Bushing, 21... Tank, 22
...Heat insulation material, 23...Horizontal cylindrical tank, 23a...
・Body, 23b...dak 1~. 23G...flange, 24...connecting pipe, 25...cooling water pipe, 26...
Base, 27... Steady rest, 30... Support hardware, 3
1a... Lid for blanking, 31b... Lid for connection, 3
2...Connection pipe joint. 7317 Agent Patent Attorney Nori Chika Lori (-i (
1 other person) Figure 3 JP-A-6L-133577 (6) Figure 5 (B) 7Z2 p Pa ■■ 〉r ”'1

Claims (1)

[Claims] A cell stack is formed by stacking a plurality of rectangular flat unit cells in a square column shape with an electrolyte layer interposed between a pair of electrodes, and this cell stack is housed in a tank. In a fuel cell, a cylindrical tank with open ends is provided with a flange at the end of the tank, and a reactant gas duct or piping for feeding into the cell stack and cooling water piping are provided on the side of the tank. The cell stack is housed in the tank and connected to the duct and piping on the tank side to form one unit.Furthermore, this one unit is connected to the tank end. By connecting reaction gas piping, ducts, or cooling water piping at the same time as the flange, multiple units are connected, and both ends of these connected multiple units are equipped with blind lids or lids with joints to connect to the system control system. A fuel cell characterized by being attached with.