高温气冷堆热气导管中石墨粉尘沉积特性分析

高温气冷堆中石墨粉尘的运动规律对反应堆安全具有重要意义。本工作采用计算流体力学方法得到热气导管中的温度场分布，在此基础上分析了热气导管中热泳沉积与湍流沉积的规律。结果表明，随着颗粒粒径的增大，热泳沉积率下降，而湍流沉积率则先减少后增大。通过比较30%FP及100%FP两种反应堆功率下的计算结果发现：反应堆功率为30%FP时对应的热泳沉积率更高，而反应堆功率为100%FP时，湍流沉积率增长更加迅速。当颗粒粒径较小时，热泳沉积与湍流沉积作用相当，颗粒粒径较大时，湍流沉积明显占主导地位。最后，采用最可几分布的粒径计算了热气导管中石墨粉尘总的沉积量，计算结果表明石墨粉尘沉积总量有限。

Analysis of Graphite Dust Deposition in Hot Gas Duct of HTGR

The behavior of the graphite dust is important to the safety of high-temperature gas-cooled reactor (HTGR). The temperature field in hot gas duct was obtained using computational fluid dynamics (CFD) method. Further analysis to the thermo-phoretic deposition and turbulent deposition shows that as the dust particle diameter increases, the thermo-phoretic deposition efficiency decreases, and the turbulent deposition efficiency initially decreases and then increases. The comparisons of calculation results for two reactor powers, namely 30%FP (full power) and 100%FP, indicate that the thermo-phoretic deposition efficiency is higher at 30%FP than that at 100%FP, while the turbulent deposition efficiency grows more rapidly at 100%FP. Besides, the results also demonstrate that the thermo phoretic deposition and the turbulent deposition are nearly equivalent when particle sizes are small, while the turbulent deposition becomes dominant when particle sizes are fairly large. The calculation results by using the most probable distribution of particle size show that the total deposition of graphite dusts in hot gas duct is limited.