弱环境流速水域内陆核电厂液态流出物排放设计优化研究

理论和实践经验均表明,内陆核电厂采用多孔扩散器有利于加快近排放口区域液态流出物的掺混稀释。基于美国环保署推荐的近区模拟工具——CORMIX专家系统,对低环境流速水文条件下的内陆核电厂的多孔扩散器开展了研究。分析表明:对于近岸布置的多孔扩散器,在低环境流速、相对较强射流以及水深较深条件下,(1)扩散器主管长度Ln与排放口下游断面的最小相对稀释比例H呈正相关,喷口直径D与H呈负相关,喷口水深HD与H呈正相关;在排热量相同的情况下,流量Q与H呈正相关。(2)对于排放口下游1 000 m断面处的最小相对稀释比例H1 000 m,各几何参数灵敏度由高到低排序为,喷口直径D、喷口数量n、主管长度Ln。研究结论可供内陆核电厂液态流出物排放工程的设计及优化参考。

Study on design optimization of liquid effluent discharge from inland nuclear power plant to water area with low environmental flow rate

Theoretical and practice experiences show that it is favorable to speed up mixing and dilution of the liquid effluent within the area near its discharging outlet by adopting porous diffuser for the inland nuclear power plant. Based on the near area simulation tools——Cornell Mixing Zone Expert System，CORMIX recommended by the U.S.EPA，the porous diffuser for the inland nuclear power plant under the hydrological condition of low flow rate is studied herein. The analysis shows that when the arrangement of the porous diffuser is nearshore under the condition of low environmental flow rate，relative stronger jet flow and deeper water depth，（1）the length of the main tube of diffuser Lnis positively correlated with H （the minimum relative dilution ratio at the downstream cross section of the discharging outlet），the spout diameter D is negatively correlated with H and the water depth of the spout HD is positively correlated with H，while the effluent flow rate Q is positively correlated with H as well under the condition of the same heat exhaust; （2）for H1 000 m，the order of the sensitivities of all the geometric parameters from high to low is to be： the spout diameter D，the spout number n and the main tube length Ln. The study conclusion can provide a reference for both the design and optimization of the liquid effluent discharge project for inland nuclear power station.