Variable-atmosphere pressure heat conductivity coefficient testing device based on transient plane source method

Abstract

The invention relates to a variable-atmosphere pressure heat conductivity coefficient testing device based on a transient plane source method. A double-screw test probe is arranged between two same tested materials with smooth surfaces, the tested materials and the test probe are integrally arranged in a tube-type high temperature furnace, a controllable environment temperature is provided for the tube-type high temperature furnace and a temperature control system, a high pressure air source is matched with a molecular pump to control the type and pressure of the atmosphere inside the high temperature furnace, a data collection and control system is connected with a temperature control system and a Hot Disk conductometer respectively, the Hot Disk conductometer connected with the double-screw test probe is used for providing test power and heating time for the double-screw test probe, and the data collection and control system is used for obtaining the heat conductivity coefficients and heat diffusion coefficients of the tested materials according to theoretical calculation of the transient plane source method. The heat conductivity coefficient test for the transient plane source method under a variable-atmosphere pressure condition is realized for the first time internationally, and the atmosphere pressure range of porous material heat conductivity coefficient test is the maximum test range reported domestically at present.

Description

Technical field: [0001] The invention belongs to the technical field of measurement, and in particular relates to a testing device for thermal conductivity under variable atmosphere pressure based on a transient plane heat source method. Background technique: [0002] Porous materials have excellent physical properties due to their low density, light weight, and large specific surface area. For example, materials with high porosity are often used as thermal insulation materials, and they have great potential in aerospace, energy and chemical industries, petroleum transportation, and construction. widely used. When porous materials are used as thermal insulation materials, their thermal insulation performance will be affected by factors such as porosity, filling atmosphere, atmospheric pressure and temperature, and the study of the variation law of thermal conductivity of porous materials under different atmospheric pressures is of great importance for the optimization design...

AI Technical Summary

Problems solved by technology

In foreign countries, the widest pressure range of the porous material variable atmosphere pressure thermal conductivity test system is 10Pa-10MPa, and the test method is the hot wire method. When the test results of the two sets of devices are discontinuous, the device is complicated and the sample requirements of the same material are relatively large

The transient planar heat source method is convenient for testing and has low material preparation requirements, and the size does not exceed 10cm 3 , high precision and other advantages, it has been widely used in recent years, and the test is convenient, but there is no report using this method to test the thermal conductivity of porous materials under different atmospheric pressures

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