LNG项目排水中余氯对近岸海域水环境影响的数值模拟

根据LNG项目排水受纳水域潮流特征以及不同季节的设计典型水文条件,利用二维水动力模型模拟了江苏近岸辐射状沙脊群浅海区的潮流场,并以此作为模拟冷排水中余氯在受纳海域迁移转化的时间变化、空间分布特征的水动力条件,同时考虑余氯在水体中的衰减效应,建立余氯二维对流-扩散模型,预测受纳水域余氯浓度空间分布、时间变化特征。根据海洋生物余氯慢性毒性阈线,定量分析了含氯排水对近岸海域水环境的影响范围,结果表明:LNG项目冷排水中余氯对近岸海域水环境影响较小。

Numerical simulation of effect of residual chlorine water from discharge of LNG project on water environment

According to the tidal current characteristics of drainage and receiving water in LNG project and the typical hydrological conditions of design in different seasons, the paper used a two-dimensional hydrodynamic model to simulate the tidal current field of water receiving residual chlorine in cold water discharge in radial sand ridge group of shallow sea area of Jiangsu maritime space. As the hydrodynamic conditions in the simulation of cold water mobility and transfer of residual chlorine in the reception area of time and space distribution characteristics,it established a two dimensional model of the transport and diffusion for the residual chlorine to predict the receiving waters residual chlorine concentration distribution and analyze its environmental impact in considering the residual chlorine in water body of attenuation effect at the same time. Finally, the scope of influence caused by the chlorine water drainage in the chlorine water''s sphere was analyzed quantitatively according to the chronic toxicity threshold line of residual chlorine. Results show that the residual chlorine in cold drainage of LNG project has less impact on the water environment in offshore area.