水利水电工程下泄水气体过饱和研究

Study on Supersaturation of Discharge Gas in Water Conservancy and Hydropower Projects

为缓解水利水电工程建设引起的河道下游水体总溶解气体(TDG)过饱和现象,系统梳理TDG过饱和的机理、影响因素,并针对不同成因、不同水利水电工程提出各类改善措施。研究表明,水利水电工程下游水中出现TDG过饱和主要与溢洪道、涡轮机等结构设计和设备有关,天然河流水温、压强等条件发生剧烈改变是导致下游水体TDG过饱和现象的主要原因,安装导流板、设计二道坝、合理布置泄水建筑物和发电厂房等结构、优化梯级水库运行调度、水流掺混、增加下泄水体含沙量可有效降低水利水电工程下游水体中TDG过饱和水平。基于自然解决方案(NbS)的生态应对策略,旨在消除该现象对河流生态造成的负面影响,为水资源合理开发及生态水利工程可持续发展提供参考。

This paper systematically summarized the mechanism and influencing factors of TDG supersaturation of downstream water body caused by water conservancy and hydropower project construction,and puts forward various improvement measures according to different causes and different water conservancy and hydropower projects.The phenomenon of TDG supersaturation in the downstream water of water conservancy and hydropower projects is mainly related to the structural design and equipment such as spillway and turbine,etc.The main reason for TDG supersaturation in the downstream water is the drastic change of water temperature and pressure in the natural river.The TDG supersaturation level in the downstream water of water conservancy and hydropower projects can be effectively reduced by installing diversion plates,designing the secondary DAMS,reasonably arranging drainage buildings and powerhouse structures,optimizing the operation of cascade reservoirs,mixing water flow and increasing the sediment concentration in the discharge water.To eliminate the phenomenon of the negative impact'of the river ecology,the strategies of reasonable development of water resources and the sustainable development of ecological hydraulic engineering based on Nature-based Solutions(NbS)were provided in the paper.