电厂温排水余氯对水环境影响的数值模拟

以扬州第2发电厂三期工程温排水问题为例,利用二维水动力模型对温排水余氯受纳水域长江扬州段潮流场进行了模拟;以该数值模拟的潮流场作为余氯输运模拟的水动力条件,利用余氯二维对流-扩散模型预测了受纳水域余氯的质量浓度分布,并分析了这种分布对水环境造成的影响.结果表明:在不利水文条件下,温排水中余氯的质量浓度空间分布范围较小,较高质量浓度的余氯分布在排水口附近的区域;由于环境水体对余氯的稀释能力较强,温升带长度有限、宽度很小,温排水中余氯对鱼类的影响是间接和微小的,对长江水生珍稀动物的生态环境几乎没有影响.

Numerical simulation of the effects of residual chlorine in cooling water discharge from a power plant on the water environment

Aiming at problem of cooling water discharge by the third stage project of the Yangzhou 2nd Power Plant,a 2-D hydrodynamic model was used to simulate the tidal current field of waters receiving residual chlorine in cooling water discharge in the Yangzhou reach of the Yangtze River.With the computed tidal current field considered to be the hydrodynamic conditions of the residual chlorine transport simulation,the concentration distribution of the residual chlorine was predicted with a 2-D convection-diffusion model and its effect on the water environment was analyzed.The results show that,under unfavorable hydrological conditions,the concentration distribution of the residual chlorine has a small range,and the high-concentration residual chlorine is distributed in water area around the outfall.It is also concluded that the length of the zone of rising temperatures is limited and the width is small because of the strong dilution capability of the water.Therefore,the residual chlorine has an indirect and small effect on fish,and has almost no effect on the ecological environment of rare aquatic animals in the Yangtze River.