JPS58166663A - Temperature regulator for fuel cell - Google Patents

Abstract

PURPOSE:To improve the heat transfer characteristics between the temperature regulating plate and heat exchange piping that comprise a temperature regulator for a fuel cell by filling their gap with a specific filling agent with excellent heat conductivity. CONSTITUTION:Grooves 6 for heat exchange piping are provided between temperature regulating plates 1 and 3 mainly made of graphite and provided with the respective reaction gas paths 2 and 4 on the reverse sides of opposed surfaces and the heat exchange pipes 5 composed of a metal raw material or carbon raw material are inserted in them. The gaps 7 between the grooves 6 and pipes 5 are filled with a filling agent consisting of boron nitride or a mixture of the boron nitride and a binding agent, mixture of graphite and phenol resin, and mixture with heat conductive graphite or copper powder. As a result, the heat resistance in the gaps 7 can be reduced and the heat transfer characteristics between the temperature regulating plates 1 and 3 and heat exchange pipes 5 can be improved and then manufacture of a temperature regulator for a fuel cell can be facilitated.

Description

[Detailed description of the invention] TECHNICAL FIELD This invention relates to a temperature control device for a cross-sectional fuel cell.

Conventionally, this type of electrical manufacturing has been shown in Fig. C91.

In Fig. 1, (1) and (3) are temperature joint plates with reactive gas passages (1, (4)) provided on opposite sides of the opposing surfaces, and the material is mainly graphite. A groove (6) for heat exchange piping is provided in the dark side of these two temperature control plates, and a heat exchange piping (6) made of a metal material or a carbon material is inserted into the groove (6) for heat exchange piping. (7) is the gap between the heat exchange pipe groove (6) and the heat exchange pipe 1M).

Next, its effect will be explained. First, when starting up the fuel cell, hot water is sent to the heat exchange piping (6) to promote the °C1 reaction, and the heat is transferred to the temperature adjustment plates +1) and (3) through the gaps, and the heat is transferred to the upper and lower temperature adjustment plates. Heats the stacked fuel cells.

During normal operation, C needs to remove the heat generated in the fuel cell in order to prevent the fuel cell from being destroyed due to temperature rise. The heat generated by the fuel cell is heated from above and below.
fii joint plates 11) and (3), and is transmitted to the heat exchange piping (5) via the gap.

The conventional temperature control device for fuel cells is constructed as described above, and since the temperature is controlled at °C, the thermal resistance of the gap is determined by the temperature control plate (1).

(3), which is an order of magnitude larger than the thermal resistance of the heat exchange pipe (6), and the thermal resistance of the heat exchange pipe (6).
This invention was made to eliminate the above-mentioned drawback of the conventional method, and it involves filling the gap with a filler material with excellent thermal conductivity. The purpose of this invention is to provide a temperature control device for fuel cells with excellent heat transfer characteristics.

An embodiment of the present invention will be described below with reference to the drawings.

In Figure 2, 'C[1 to (6)] are the same as in Figure 1.

(7) is a filler filled in the gap.

Characteristics required of C as a filler include good thermal conductivity, chemical resistance, and flexibility or lubricity capable of absorbing thermal stress.

From this point of view, boron nitride or a mixture of boron nitride and a binder, a mixture of graphite and a phenolic resin, a mixture of thermally conductive graphite or copper powder are used as fillers.

Next, when using C1 boron nitride and a binder as a manufacturing method, the binder is °((ao-B203.There are phenolic resins, etc.)
．． Mix about 6% in the dark and fill the gap between the temperature control plate and the heat exchange piping at 200-400℃ and 400-500 kt)/ci.
Heat and pressurize for 2 to 4 hours under the following conditions. At high temperature and high pressure, cracks are less likely to occur, the filling becomes denser, and a product with better thermal conductivity can be obtained. Next, in the case of phenolic resin, first, a phenol resin dispersion medium is used or the phenol resin and boron nitride are directly mixed to form a uniform mixture of boron nitride and phenol resin. In the case of direct mixing, the weight ratio of boron nitride is about 60 to 70%, and in the case of using a dispersion medium, it is about 70 to 90%. This mixture is filled into the gap, and the weight specific force of the phenolic resin (
In the case of a thick L1, for example, it is sufficient to keep the pupils open all day and night at an air temperature of 5 kg/cd, and if the Xt ratio of the phenol resin is small, for example, 80 to 200°C, tokg,'
It is sufficient to leave it in state i for about 2 hours. When any binder is used, it is desirable to treat the heat exchange piping with a mold release agent such as Teflon paste or silicone oil to prevent the heat exchange piping from sticking to the temperature control plate.

Next, in the case of a mixture of graphite and phenolic resin, the process is almost the same as that for a mixture of boron nitride and phenolic resin.

In the case of thermal conductive grease and graphite fixing mixtures, the particle size of graphite and its mixing ratio have a great influence on the viscosity and thermal conductivity of the mixture. The particle size C is desirably an average particle size of 0.80 to 60M, and preferably contains many fine particles.

Regarding the mixing ratio, C is the weight fraction of graphite and 'CsO
About 70% is desirable. Since the mixture becomes harder as it approaches 70%, the work can be easily carried out by mixing while heating the mixture to, for example, 80° C. and filling the gap with the mixture while humidifying the mixture.

The case of thermally conductive grease and copper powder is almost the same as the case of graphite, and regarding the mixing ratio, C is the heavy weight fraction of copper powder, and it is desirable that it be about 80% of rhG. A portion of the copper powder may be replaced with graphite.

At startup, C transfers heat from the heat exchange pipe (6) through the filler (7) to the temperature lfm node plate (3). During steady operation, C is the temperature - node plate +1), +8). Heat is transferred to the C heat exchange pipe (5) through the filler (7).

Regarding thermal conductivity, for example, °C is ~5.4 (kcal/mhrdeg) for a mixture of boron nitride and a binder, and ~8. o (
kcal/imhrdog) It's so dark.

Regarding thermal stress due to the difference in coefficient of thermal expansion between the filler and the heat exchange piping, C is due to boron nitride, a mixture of boron nitride and a binder, and a mixture of graphite and phenolic resin, both of which have good solid lubrication. Also, by using a mold release agent, they can be prevented from sticking, and slippage between the filler and the heat exchange piping will not be a problem. Also, the mixture of thermally conductive grease is a grease-like substance and does not pose a problem.

Further, boron nitride and a mixture of boron nitride and a binder are insulative and can easily insulate the warm IfIm joint plate and the heat exchange piping.

In addition, in the above embodiment, warm 11:, i14 node plate tt),
Although we have explained the case where there are reactive gas passages (2) and (4) on both the upper and lower sides of (a), it is also possible to have reactive gas passages only on either one of the upper and lower sides, or it is also possible to have reactive gas passages on both sides. It is not necessary to provide C.

As described above, according to the present invention, since the gap between the temperature control plate and the heat exchange pipe is filled with a filler, processing accuracy can be lowered, that is, the device can be made inexpensive, and it can be used for fuel cells with good heat transfer characteristics. This has the effect of providing a cooling and heating device.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional temperature control device for fuel cells;
FIG. 2 is a sectional view showing a #jA degree adjusting device for a fuel cell according to an embodiment of the present invention. +1), (3)--warm adjustment plate, (5)...heat exchange piping, (6)...groove for heat exchange piping, (7)...
filler. Note that the same reference numerals in the figures indicate the same or equivalent parts. Agent Makoto Kuzuno - Procedural amendment (spontaneous) Mr. Commissioner of the Japan Patent Office■, Indication of case Patent application No. 1987-8O-it No. 2,
Name of the invention: Temperature control device for fuel cells 3, relationship with the case of the person making the amendment Patent applicant address: 2-2-3 Marunouchi, Chiyoda-ku, Tokyo Name (601) Mitsubishi Electric Corporation Representative Jinhachibe Katayama 4. Address of the agent: 5-2-3 Marunouchi-chome, Chiyoda-ku, Tokyo; Column 6 of the detailed explanation of the invention in the specification subject to the amendment; "Active material" is corrected to "solid lubricant." From then on t 11

Claims (1)

[Scope of Claims] (1) A temperature control device for a fuel cell having a temperature control plate and a heat exchange pipe disposed in the temperature one-node plate for exchanging heat with the temperature control plate. C1 A temperature 1f1m regulating device for a fuel cell, characterized in that a filler is filled in the gap between the temperature adjusting plate and the heat exchange pipe. (2) A fuel cell fuel cell according to claim 1, characterized in that boron nitride or a mixture of boron nitride and a binder is filled as a filler. ! 11 section device. (3) Clause 1 of the patent claim, characterized in that it is filled with a mixture of graphite and phenolic resin as a filler.
2. Temperature control device for fuel cells as described in 2. (4) The temperature control device for a fuel cell according to claim 1, characterized in that it is filled with a mixture of C graphite and thermally conductive grease as a filler. 1M> The temperature control device for a fuel cell according to claim 1, wherein a mixture of copper powder and thermally conductive grease is filled as a filler. (6) The temperature control device for a fuel cell according to claim 1, wherein a mixture of graphite, copper powder, and thermally conductive grease is filled as a filler.