摘要
为提高温排放的初始稀释度、减小排口近区超标区域,扩散器常被用于电厂排海工程。本文采用CORMIX经验模型与Realizable k-ε紊流模型相结合的方法,开展了孟加拉湾河口水域燃煤电厂排水扩散器的参数优化及温排水稀释特性研究。首先分析了扩散器长度、出流角度、出流流速等参数对初始稀释的影响,并对扩散器型式进行了比选,提出潮汐水域采用交错型扩散器有利于增大近区稀释度。针对推荐扩散器,研究依据准恒定假设,模拟了涨潮、高平、落潮、低平四个特征潮态的温排水稀释扩散过程。结果表明:不同潮态的温度场空间结构、温升分布及稀释效果具有显著差异,低平潮对温排水掺混稀释最为不利;涨潮与落潮时顺流向与逆流向的喷口射流结构也不尽相同,顺流向射流更加细长。研究成果可为电厂排放口工程设计与环境影响评价提供技术支撑,也可为浅水型海域扩散器选型提供参考。
In order to increase the initial diluting degree of the thermal discharge and reduce the standard-exceeding area near the discharge outlet,outfall diffuser is often adopted to the project of thermal discharge into the sea for the thermal power plant.With the method of combining the empirical model of CORMIX with the Realizable k-εturbulence model,the parameter optimization and the study of the dilution characteristics of the thermal discharge of the outfall-diffuser for the coat-fired power plant at the water area of the estuary of the Bay of Bengal are carried out herein.At first the influences from the parameters of the length,the discharge angle,the discharge flow rate,etc.of the diffuser on the initial dilution are analyzed,and then the types of diffuser are comparatively selected,thus it is proposed that the adoption of the stagger-typed diffuser is favorable to increase the diluting degree within the area nearby.For the recommended diffuser,the thermal discharge diffusing processes of four tidal patterns,i.e.flood tide,high tide,ebb tide and low tide,are simulated in accordance with the relevant quasi-steady hypothesis adopted in the study.The result shows that the spatial structure of temperature field,the temperature-rise distribution and the diluting effect of different tidal patterns are significantly different,from which the low tide is most unfavorable for mixing and diluting the thermal discharge,while the jet-flow structures in the direction of current and in the direction of contra-flow at the nozzle of diffuser are also different and the jet-flow in the direction of current is more long and thin.The study achievements can not only provide technical support for both the design of the project of discharge outlet for power plant and its environment impact assessment,but also can provide reference for the type selection of the outfall diffuser applied to the shallow-water sea area.
作者
罗奇蔚
赵懿珺
曾利
韩瑞
LUO Qiwei;ZHAO Yijun;ZENG Li;HAN Rui(State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,China Institute of Water Resources and Hydropower Research,Beijing 100038,China)
出处
《水利水电技术》
北大核心
2019年第11期84-94,共11页
Water Resources and Hydropower Engineering
基金
国家自然科学基金资助项目(51309257)
