管状保冷材料表观导热系数曲线的测定

MEASUREMENT OF SUPERFICIAL THERMAL CONDUCTIVITY OF CYLINDER SHAPED COLD INSULATION MATERIALS

研制了一台在一维、径向、稳态传热条件下测定管状保冷材料低温表观导热系数的防护端头型微机监控装置，该装置由本体、液氮自动输入系统、液氮蒸发量测量系统、温度自动监控系统及抽真空系统等５大部分组成。装置具有自动输液、自动检测及控制温度等多种功能。由于分散式数据检测器ＩＭＰ３５９５１Ｃ和３５９５１Ｄ的应用；使得该装置具有漂移小、波动小、反应快及精度高等特点，其总体误差不超过３．０５％，该装置的研制成功为保冷材料及结构的导热系数测试提供了有效的手段。对泡沫玻璃、聚氨酯泡沫塑料和聚乙烯泡沫塑等３种保冷材料进行了低温表观导热系数测定，在国内首次给出了此３种常用保冷材料的低温表观导热系数曲线、为保冷工程的设计、选材提供了可靠的数据。

A monitor for determining the superficial thermal conductivity of the cylinder shapedcold insulation materials under low temperature,enhanced with a computer-controlled endheat compensation system,is developed based on the one-dimensional steady heat conductionprinciple, The experimental device consists of five parts:the cylinder assembly, the auto-matic liquefied nitrogen feeder,the nitrogen evaporating rate measurement instrument,thetemperature measurement and control system and the vacuum system. By using the dis-tributed measurement pods,IMP35951C and 35951D,this device has the advantages ofhigh measurement accuracy, low drift and oscillation,and high sensitivity.The relativemeasurement error can be less than 3.05%,The superficial thermal conductivity of glassfoam,polyurethane foam and polyethylene foam was measured at different temperatures andthe reliable data obtained can be used in engineering design.