高坝工程总溶解气体过饱和与水体含沙量关系
Relation of total dissolved gas supersaturation and suspended sediment concentration of high-dams
-
摘要: 为研究伴随高坝泄水产生的总溶解气体(TDG)过饱和现象与水体中含沙量关系的问题,提出切实可行的减缓TDG过饱和影响的措施,通过实验的方法,对含沙水体中TDG过饱和的生成和释放进行了研究分析。结果表明:同样初始条件下,在含沙水体与清水中的TDG过饱和生成过程中,TDG过饱和度没有明显变化。在TDG释放过程中,含沙水体中TDG释放速率明显快于清水中TDG释放速率,据此提出可通过开启排沙孔等泄洪调度方式使泄流中悬沙含量增加,促使TDG沿程释放加快,降低其对鱼类的影响。Abstract: In order to resolve the issue concerning the relation of total dissolved gas (TDG)supersaturation and sus-pended sediment concentration of high-dams,a practical abatement measure for TDG supersaturation is put forward in this study.Based on a series of experiments,the production and release of TDG supersaturation in sediment laden flow are studied.The result shows that the production of TDG supersaturation remains almost the same level in either sediment laden flow or clear water for the same initial conditions.The rate of release of TDG supersaturation in sediment laden flow is significantly faster than that in clear water.The suspended sediment concentration can be increased through the use of bottom intakes,speeding up the release of TDG supersaturation.Such a measure can minimize the effect of TDG supersaturation on fish species in the downstream region of high-dams.