应用CFD方法研究雷诺数对烟囱气体混合均匀性影响

摘要/Abstract

摘要： 为研究各种流态下核设施烟囱内气体混合均匀性情况,应用计算流体力学(CFD)方法,建立了仿真模型,主烟囱内雷诺数范围800~70 000。仿真结果表明:雷诺数变化对于主烟道风速分布有重要影响;8倍水力直径以下,随监测截面升高,风速分布将更为均匀,8倍水力直径以上,一定程度内增强湍流,可提高风速分布均匀性,流态处于完全湍流后,继续提高雷诺数对风速的分布均匀性无益;对于示踪气体,各监测截面均达到了较充分的混合,管道内雷诺数低于29 000时,其在各截面上的混合均匀性伴随雷诺数升高有细微的降低,雷诺数超过29 000后混合均匀性变化不再显著。对比仿真结果与试验结果,风速及示踪气体浓度仿真结果与试验测量值具有较好的一致性。

关键词: 气态流出物监测, 计算流体力学, 混合均匀性

Abstract: In order to study the gas mixing uniformity in the ventilation duct under various flow status, we established a simulation model by using computational fluid dynamics method. The Reynolds number covers the range of 800 to 70 000. The simulation results showed that: the change of Reynolds number has an important influence on the velocity distribution; When the height is less than 8 times hydraulic diameter, the velocity distribution will become more uniform when the monitoring surface is raised. In the region of more than 8 times hydraulic diameter, increasing the degree of turbulence can improve the uniformity of velocity distribution. However, when the flow state reaches full turbulence, it is not beneficial to increase the Reynolds number. For the tracer gases, they could reach a sufficient mixing in each monitoring surface. When the Reynolds number is lower than 29 000, the mixing uniformity of the tracer gas on each surface will slightly decrease as the Reynolds number increases. But when the Reynolds number exceeds 29 000, the uniformity of mixing is no longer significant. Comparing the simulation results with the test results, the simulation results of wind speed and tracer gas concentration are in good agreement with the test measurements.

Key words: gaseous effluent monitoring, computational fluid dynamics, gas mixing uniformity

中图分类号:

X837

郑金阁, 程卫亚, 郭浩城, 刘伟富, 王晨潇, 郝桂珍, 赵宇伦, 陈凌. 应用CFD方法研究雷诺数对烟囱气体混合均匀性影响[J]. 辐射防护, 2022, 42(5): 411-417.

ZHENG Jinge, CHENG Weiya, GUO Haocheng, LIU Weifu, WANG Chenxiao, HAO Guizhen, ZHAO Yulun, CHEN Ling. Research on the influence of Reynolds number on the uniformity of gas mixing in chimney by CFD method[J]. RADIATION PROTECTION, 2022, 42(5): 411-417.

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