壁面开槽尺寸及槽内填充物对测温精度和热流分布的影响

Effecct of the Size of Solts in Wall and Materials Embedded on Temperature Measurement and Heat Flux Disrtibution

通过管壁对管道内流体等热流加热时 ,其内表面的温度一般通过在外表面开槽 ,再把热电偶嵌入 ,根据测得的温度利用傅立叶定律来确定。本文数值研究了壁面开槽的几何尺寸和槽内填充材料对壁温测定精度和对流换热面上的热流和温度分布的影响 ,发现 :合适的填充材料和开槽几何尺寸对提高测量精度、改善对流换热面的热流分布十分重要 ,二者中任何一项选取不当都会引起不容忽视的测量误差 。

When the fluid in a tube is heated with uniformly distributed heat flux through the tube wall,the temperatures of local points on the inner surface of the tube wall are often detrmined with the Fourier's Law.That means the temperatures of some points in the tube wall should be measured with the thermocouples embedded in some slots opened form the outside surface of the tube.The effect of the size of the slots and the materials embedded in them on the temperature measurement and the heat flux distribution on the tube inner sruface is numerically researched in this paper.It is found that the conductivity of the embedded materials and the slot size strongly affect the temperature measurement accuracy and the heat flux distrbution.Each of them is selected unsuitably,the great error of temperature measurement may be caused,which also makes the heat flux distribution not correspond to what people assume probably.