纤维隔热毡有效热导率测试方法研究

Testing Method of Effective Thermal Conductivity of Fibrous Insulations

文摘纤维隔热材料热导率的测试是高马赫数可重复使用飞行器（RLV）金属热防护系统（TPS）研究中的一个难点。本文以NASALangley研究中心一维稳态有效热导率测试装置为依据,设计了测试温度达1 600℃、压力在1×10^-3-1×10^5Pa的高温石墨平板炉,并对该设备的设计原理、装置构造、测试方法以及数据采集等方面进行了讨论,对三种国内不同厂家生产的高温纤维隔热毡的有效热导率进行了测试。结果表明,该设备在经历一定时间的稳态处理后,获得了稳定的热流密度,进而得到不同温度下的一维稳态有效热导率。测试结果表明纤维隔热毡的有效热导率随温度的增加而增加,在高温下,辐射成为影响材料导热能力的主要因素。

Effective thermal conductivity measurement of fibrous insulations is a difficulty in the study of metallic thermal protection system （TPS） for reusable launch vehicles （RLV）. According to the one dimension steady-state effective thermal conductivity testing apparatus invented by NASA langley research center, a high temperature graphite fiat stove is developed independently, whose main technical parameters are：the highest testing temperature is 1 600℃ and the range of pressure is between 1 × 10^-3 and 1 × 10^5 Pa. The principle, the instrumentation, testing method and data collection are analyzed in detail. Effective thermal conductivity of three domestic high temperature fibrous insulations is measured at different temperature. The stable heat flux density, from which effective thermal conductivity is calculated, is obtained after a period of thermal stable treating. The testing results showed that effective thermal conductivity of fibrous insulations is increased with the increase of temperature. At high temperature, radiation is the main factor influencing thermal transfer.