基于汽泡动力学的过冷沸腾机理研究与模型构建

Fuel assembly is the core component of nuclear reactor. The thermal performance, especially critical heat flux (CHF) influences the reliability, safety and economy directly, is one of the most focus performances. The prediction accuracy of local parameter distribution of subcooled boiling is important for the prediction accuracy of fuel assemble CHF occur value and position at next step. The mechanism research of subcooled boiling model based on bubble dynamics is the mechanism analysis about the force that bubble leaves the wall. The bubble departure and lift-off estimate rule is given. The bubble behavior influence about wall heat flux distribute is researched. And the development of subcooled boiling numerical model at normal flow, high wall heat flux is finished. The influence of bubble departure and lift-off are both considered in the model. The model can predict the bubble detachment diameter reasonably, rise the predict accuracy of near wall void fraction at full developed subcooled boiling range. The model can be used in thermal performance prediction and choose of fuel assembly in future.

燃料组件是核反应堆的核心部件。燃料组件的热工性能，尤其是临界热流密度(CHF)直接影响到核反应堆的可靠性、安全性和经济性，是最受关注的性能之一。正确预测过冷沸腾发生时局部参数分布，对下一步预测燃料组件的CHF数值和发生位置，具有重要意义。基于汽泡动力学的过冷沸腾机理研究，是对汽泡离开壁面的受力进行机理分析，给出汽泡脱离与汽泡浮升判断准则，研究汽泡行为对壁面热流分配的影响，构建在正常流速、壁面热流密度较大时适用的过冷沸腾数值模型。模型同时考虑了汽泡脱离与汽泡浮升影响，可合理预测汽泡离开壁面直径，提高充分发展过冷沸腾区域近壁面空泡份额预测准确性。具有对燃料组件格架进行热工性能预测与筛选的良好应用前景。

燃料组件是核反应堆的核心部件。燃料组件的热工性能，尤其是临界热流密度(CHF)直接影响到核反应堆的可靠性、安全性和经济性，是最受关注的性能之一。正确预测过冷沸腾发生时局部参数分布，对下一步预测燃料组件的CHF数值和发生位置，具有重要意义。本项目对汽泡离开壁面的受力进行机理分析，对汽泡脱离与汽泡浮升，采用壁面温度与流体饱和温度差为判断准则，构建了考虑汽泡脱离与汽泡浮升的汽泡直径模型。该模型适用于高过冷度过冷沸腾段及充分发展过冷沸腾区域，部分工况符合良好。可用于对燃料组件格架进行热工性能预测与筛选。