基于相敏瞬态热测量的双壁换热管层间接触热阻实验研究

Study on the contact thermal resistance of double-walled heat transfer tubes based on phase-sensitive transient thermal measurement

双层316L不锈钢换热管道被广泛应用于反应堆蒸汽发生器中,其层间接触热阻(TCR)是换热管的重要性能指标。针对这种管状结构的传热测量,设计并搭建了基于相敏瞬态电学热测量方法的实验台,在室温环境下开展实验。通过对传热模型的理论分析排除了外部空气自然对流对相位测量的影响,并由单层316L不锈钢换热管的热导率测量验证了实验系统的可靠性,测量值与其他文献报道的数值误差在6%以内。对双层换热管道的层间接触热阻(TCR)进行测量,实验结果揭示了双层管层间配合应力与接触热阻之间的关联性,并由实验结果出发讨论了界面周向的不均匀应力分布对双层管传热的影响。

Double-walled heat pipe is widely used in reactor steam generator, and its interlayer contact thermal resistance(TCR) is an important performance index of heat pipe. In order to measure the thermal properties of this tubular structure, an experimental platform based on phase sensitive transient electrical heat measurement method was designed and built. Through theoretical analysis of the thermal model, the influence of natural convection of external air on phase measurement was excluded. The thermal conductivity of single-wall 316 L stainless steel heat exchange tube was measured to validate the experimental system, and the relative error between the measured values and those reported in other articles was within 6%. The thermal contact resistance(TCR) of the double-layer heat transfer pipe was measured, the correlation between the interlayer mating stress and the contact thermal resistance of the double-wall pipe was revealed, and the influence of the inhomogeneous stress distribution in the circumferential direction on the heat transfer of the double-wall pipe was discussed.