滨海核电厂取水明渠防波堤设计对取水卷载效应的影响

Impact of breakwater design in water intake open channels of coastal nuclear power plants on entrainment effects

摘要

【目的】核电厂冷源安全是保障机组安全稳定运行的前提。近年来,受海洋环境变化影响,海洋生物大规模聚集引发取水系统堵塞事件频发,对核电冷源安全构成严峻威胁。为系统性提升取水安全保障能力,同时减轻取水工程对海洋生态环境的影响,开展了取水卷载的针对性研究。【方法】采用三维水动力模型耦合粒子迁移模型,系统研究了核电厂取水明渠不同防波堤设计对取水流场分布及取水生物卷载效应的影响。【结果】结果显示:防波堤设计弧度为90°,取水设计流速小于潮流平均流速,取水口进流非均匀度约为3时,水流对生物的疏导效应较好,生物卷载率较低,与其他设计情况相比,生物卷载率可减少约50.5%。【结论】不同防波堤设计对明渠取水流场特性等存在明显影响,对取水口随流迁移的海洋生物产生了一定的聚集或疏导效应,进而影响了取水生物卷载。适宜的防波堤设计可以显著减缓取水对海洋生物的影响,降低冷源堵塞风险。研究可为滨海核电厂取水工程设计优化、取水卷载效应定量评估提供方法,为保障取水安全及生态运行提供依据。

Abstract

[Objective] The safety of the nuclear power plant cold source is a prerequisite for ensuring the safe and stable operation of generating units. In recent years, frequent incidents of water intake system blockage triggered by large-scale aggregation of marine organisms driven by environmental changes in marine ecosystems have posed serious threats to the safety of nuclear power plant cold source. To systematically enhance the safeguarding capacity of water intake systems while mitigating the impact of intake engineering projects on the marine ecological environment, it is imperative to conduct targeted research on water intake entrainment. [Methods] A three-dimensional hydrodynamic model coupled with a particle migration model was used to systematically investigate the impact of different breakwater designs in water intake open channels of nuclear power plants on the distribution of intake flow fields and the biological entrainment effect of water intake. [Results] The result showed that when the breakwater was designed with a curvature of 90°, the designed water intake velocity was lower than the average tidal flow velocity. The inflow non-uniformity at the intake was approximately 3, and the hydrodynamic conditions demonstrated favorable guiding effects on marine organisms and a lower entrainment rate. Compared to other design scenarios, this configuration could reduce entrainment by approximately 50. 5%. [Conclusion] Different breakwater designs significantly affect the flow field characteristics of open-channel water intake, generating aggregation or guiding effects on marine organisms migrating with the flow near intake structures. This consequently affects biological entrainment during water intake. Appropriate breakwater designs can substantially mitigate the impact of water intake operation on marine organisms while reducing cold source blockage risks. The findings provide method ologies for optimizing the engineering design of water intakes in coastal nuclear power plants and quantitatively assessing water intake entrainment effects, thereby offering a basis for ensuring water intake safety and ecological operation.

关键词

取水明渠 / 防波堤 / 水动力 / 卷载效应 / 核电冷源安全 / 滨海核电厂 / 粒子迁移模型 / 海洋生态效应

Key words

water intake open channel / breakwater / hydrodynamics / entrainment effect / safety of nuclear power plant cold source / coastal nuclear power plant / particle migration model

基金资助

国家重点研发计划(2022YFC3203903)

国家自然科学基金(52179083)

国家自然科学基金(42206214)