液膜蒸干模型在液态金属 CHF 预测中的应用

摘要

为对圆管中环状流烧干型沸腾临界进行预测，建立了考虑液滴沉积夹带作用的液膜蒸干模型。沉积率、夹带率等相关关系式采用水等常规流体的已有关系式。在一定参数范围内，将模型预测结果与实验数据和经验关系式进行了比较。结果表明：基于常规流体的液膜蒸干模型大体可应用于液态金属，但在临界热流密度（CHF）较大时可能造成较大偏差；钠、钾两种液态金属在CHF较低时预测准确度区别不大，但在CHF较高时区别较为明显。为更加准确预测液态金属CHF ，应开发专门的沉积率、夹带率等相关关系式。%A film dryout model considering the deposition and entrainment of droplets w as established to obtain the critical heat flux (CHF) of liquid metal in the flow of annular two-phase flow in tubes . The correlations of deposition rate , entrainment rate and so on for conventional fluids (e .g . water ) were used , and the initial entrainment fraction was determined according to experimental data . T he results show that the correlations for conventional fluids could be used for predicting CHF of liquid metal approximately , but relatively large error might occur for large heat flux .The accuracy of this model for sodium and potassium is similar for small heat flux , but has some differences for large heat flux . Special correlations of deposition rate ,entrainment rate and so on should be developed in order to predict the CHF of liquid metal more accurately .