Asme Plan Hot Method

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ASME 2013 Summer Heat Transfer Conference
ASME2013
July 14-19, 2013, MINNEAPOLIS, MINNESOTAL, USA

HT2013-17359

MEASUREMENT OF THERMAL CONDUCTIVITY FOR INSULATION MATERIALS IN HIGH TEMPERATURE BASED ON TRANSIENT HOT-PLANE METHOD

|Guanfu Pan |Fan Yu | |Thermal Engineering Department, University of Science and Technology |Thermal Engineering Department, University of Science and Technology | |Beijing |Beijing | |Beijing, China,100083 |Beijing, China,100083 | |panguanfu_ustb@163.com |fanyu@me.ustb.edu.cn |

Abstract
Acquiring the thermal conductivity in high temperature accurately has important implications for using insulation materials. In this paper, the measurement principle of the transient hot plane method is introduced. For rising the operating temperature, the plane heat source with film is changed to no film one. So the measurement errors caused by film can be eliminated. Because of the low thermal conductivity of insulation materials and the sample should be heat up until high temperature. The preheating time will be too long. In order to shorten the time of preheating sample before measuring, this text introduce an original preheating method called center preheating method which is verified by the numberical simulating result. After the experimental apparatus has been established, practical measurements about thermal conductivity and thermal diffusivity have been made with ceramic fibre material in environment temperature 23.9~746.9℃. These experiments demonstrate favorable reproducibility and accuracy under the established apparatus high temperature environment.

1 INTRODUCTION
Insulation materials are intensively used in aerospace, chemical industry and construction industry [1,2]etc. It is well known that the thermal conductivity as well as the thermal diffusivity vary extensively depending on the structure, density, porosity, electrical conductivity, etc., of different materials [3]. The thermal conductivity as an crucial evaluation parameter may change significantly with the temperature change. Since insulation materials are normally under high temperature, acquiring the thermal conductivity in high temperature accurately has important implications for proper utilization of insulation materials. Other thermal properties, like the thermal diffusivity and specific heat capacity, are also important only under transient conditions [4]. It is very necessary to have a well-suited and accurate method for measuring the thermal conductivity and diffusivity for insulation materials in high temperature [5]. The transient hot-plane method introduced in this article is proved can be effectively used to measure thermal conductivity for insulation materials in high temperature. Because of the low thermal conductivity of insulation materials [6], and the sample should always be test when heat up to high temperature. However, the preheating time can be too long by the conventional heating up method, even the physical and chemical properties would change in high temperature during such long time. So in the first two parts this paper will introduce an original preheating method, center preheating method. This center preheating method will shorten the preheating time substantially and control the measuring point temperature in an easier manner. Numberical simulations are made in the third part for models with experimental heat transfer conditions, verified the effects of center preheating method. The fourth part implements this transient hot-plane method to test...
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