【摘要】 设计了具有半球结构的3种特殊加热面,采用数值方法对池沸腾换热过程进行了数值模拟,得出了加热表面热流密度与加热面过热度之间的关系,并对恒热流加热条件下的临界热流密度进行了预测。数值计算结果表明:与平面结构相比,文中所提出的具有半球结构的3种特殊加热面均提高了沸腾换热效率。通过对所采用的3种特殊加热面进行比较分析,发现沸腾换热效率随半球结构数量的增多而增大。对沸腾换热效率及临界热流密度进行综合考虑,发现当半球结构数量为16时,换热效果为最佳。值得注意的是,当半球数量为36时,该结构具有最低临界热流密度。更多还原

【Abstract】 Three special heated surfaces with hemispherical structures were designed. Numerical method was applied to simulate the pool boiling heat transfer process. Then, the relationship between the heat flux of the heated surface and wall superheat was obtained, and the critical heat flux(CHF) was predicted under the condition of constant wall heat flux as well. Compared to the case with plane heated surface, the numerical results show that the boiling heat transfer efficiency of the special heated surfaces with hemispheres proposed in present work is improved. Through the comparative analysis of the three special heated surfaces adopted in present work, it is found that the boiling heat transfer efficiency increases with the augment of the number of hemispheres. Taking the boiling heat transfer rate and critical heat flux(CHF) into consideration, it is found that the case with 16 hemispheres has the best heat transfer performance. Remarkably, the case with 36 hemispheres has the lowest value of critical heat flux among the presented cases.更多还原