Device for testing heat conductivity coefficient and contact thermal resistance of gas diffusion layer in compressed state

Abstract

The invention provides a device for testing the heat conductivity coefficient and the contact thermal resistance of a gas diffusion layer in a compressed state. The device comprises a heating unit, acooling unit, a heat flow column, a heat insulation cover, a temperature measuring unit, an extensometer and a data processing unit; the heating unit comprises a heat insulation cushion block, a heating water tank and a heating constant-temperature water tank; the cooling unit comprises a cooling water tank with a connector at the top and a cooling constant-temperature water tank; the heat flow column comprises an upper heat flow column and a lower heat flow column, the lower end of the upper heat flow column and the upper end of the lower heat flow column are in threaded connection with replaceable test heads, and a test sample is clamped between the replaceable test heads at the upper and lower ends; the heat insulation cover comprises an upper heat insulation cover and a lower heat insulation cover; the temperature measuring unit comprises a plurality of armored thermal resistors and a miniature thermocouple; and the data processing unit is electrically connected with the temperature measuring unit and the extensometer. The device is simple in structure, is combined with a universal testing machine for use, controls the pressure with high precision, and can test the effective heat conductivity coefficient of the gas diffusion layer in a compressed state.

Description

technical field [0001] The invention relates to the technical field of fuel cells, in particular to a test device for the thermal conductivity and contact thermal resistance of a gas diffusion layer in a compressed state. Background technique [0002] During the operation of the proton exchange membrane fuel cell, it is easy to cause the proton exchange membrane to lose water due to the high local current density and high temperature, resulting in a decrease in battery performance. The gas diffusion layer is one of the important components of the proton exchange membrane fuel cell. Eliminating the waste heat generated during the operation of the cell is one of the important functions of the gas diffusion layer. Therefore, measuring the thermal conductivity of the gas diffusion layer is crucial in the development of the fuel cell. important. Since the gas diffusion layer is a porous medium, it will deform during the battery assembly process, resulting in a change in its effe...

AI Technical Summary

Problems solved by technology

[0013] According to the existing test device proposed above, the thickness of the test sample is usually required to be more than 1 mm, while the thickness of the gas diffusion layer is usually within 0.2 mm, which cannot meet the test requirements; it is impossible to accurately control the pressure applied on the sample surface and accurately obtain the pressure of the sample under compression. Actual thickness; in the measurement process, the contact thermal resistance between the sample and the contact surface is usually ignored, which brings a large error to the measurement, and the material in contact with the sample cannot be replaced according to actual needs, and the contact thermal resistance between different materials and the gas diffusion layer is tested ; The operating instrument is usually large in size and complex in structure, which is difficult to implement and operate, so a test device for the thermal conductivity and contact thermal resistance of the gas diffusion layer in the compressed state is provided

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