在高温高压下测定液体导热系数的方法

本文描述了在高温高压下快速测定液体导热系数的方法.温度和压力分别达到250℃和25.0MPa,以玻璃包封的热敏电阻作为加热元件,用桥路测定热敏电阻的dV/dt,由dV/dt计算介质的导热系数,每次测量时间为1.5秒,用六个已知导热系数的参考液体标定了装置,平均偏差小于±2%.该装置不仅可以测量有机液体,而且也可以测量导电液体或溶液.

An Apparatus for Measuring Thermal Conductivity of Liquids at High Temperatures and High Pressures

This paper describes an apparatus for the rapid measurement of thermal conductivity of liquids in the temperature range from 150 to 250# and in the pressure range up to 25.0MPa. A small bead-in-glass thermistor was used as a sensitive element. The thermistor probe, which is in a circuit with a bridge, was immersed in liquid under investigation. When a heating current was passed through the thermistor, the dV/dt of the bridge was measured. The thermal conductivity of the liquid under investigation λ could be calculated with the equation λ=A-B dV/dt, where A and B are instrument constants determined by the data of standard liquids. The time of meassuring dV/dt was 1.5seconds. The apparatus was calibrated by using six standard liquids at "different temperatures and pressures, the average deviation of measurements was within±2%. The apparatus is capable of not only measuring organic liquids, but also measuring electrolytic liquilds or solution.