For the purpose of enhancing thresholds of nucleate boiling and ensuring working safeties for DEMO reactor, numerical analyses of the influences of twisted tapes and fluid thermal-hydraulic parameters on DNB-type CHF and pressure drops have been carried out on plain tubes and tubes with twisted tape inserts. The research campaign has been conducted following the Eulerian multiphase model and the critical heat flux boiling model based on FLUENT software. Numerical simulation methods were verified by comparing the simulation results with the experimental data. Comparisons of critical heat flux and pressure drop between experiment and computation show a good agreement, indicating that present methods are reliable for DEMO divertor design. The temperature distribution, void fraction and pressure drop for two-phase subcooled boiling water flow were obtained. The simulation results show that the DNB-type CHF can be enhanced by decreasing twist ratios or increasing tape width ratios. Compared with plain tubes, tubes with twisted tape inserts can efficiently enhance DNB-type CHF. Furthermore, the DNB-type CHF is assessed to be directly proportional to mass fluxes. The results also indicate that the pressure drops increase with increasing tape width ratios and mass fluxes, but increase with the decrease of twist ratios.

为了提高成核沸腾的阈值并确保DEMO反应器的工作安全性，对普通管和加捻管进行了扭带和流体热工参数对DNB型CHF和压降影响的数值分析。胶带插入物。该研究活动是遵循欧拉多相模型和基于FLUENT软件的临界热通量沸腾模型进行的。通过将仿真结果与实验数据进行比较，验证了数值仿真方法的正确性。实验和计算之间的临界热通量和压降的比较显示出良好的一致性，表明当前方法对于DEMO偏滤器设计是可靠的。温度分布 得到了两相过冷沸腾水流的空隙率和压降。仿真结果表明，可以通过降低扭曲比或增加带宽比来增强DNB型CHF。与普通管相比，具有扭曲胶带插入物的管可以有效地增强DNB型CHF。此外，DNB型CHF被评估为与质量通量成正比。结果还表明，压降随带宽度比和质量通量的增加而增加，但随扭曲比的减少而增加。DNB型CHF被评估为与质量通量成正比。结果还表明，压降随带宽度比和质量通量的增加而增加，但随扭曲比的减少而增加。DNB型CHF被评估为与质量通量成正比。结果还表明，压降随带宽度比和质量通量的增加而增加，但随扭曲比的减少而增加。