摘要
扬水曝气是湖泊水库富营养化控制的有效新技术。本文采用不同的扬水曝气器出流结构,运用FLUENT数值模拟了扬水曝气器外围流场和藻类浓度场,模拟的流速和藻类浓度结果与实测结果吻合较好。在典型曝气量25m3/h下,运用动量方程计算了不同出流结构条件下设备所受的冲击力。计算结果表明采用上升筒侧壁开孔和设导流板的优化出流结构使设备所受最大冲击力减少46.4%;最大冲击力随水流速度峰值增加而增大,但呈非线性关系。采用优化的出流结构,在水库典型水深55 m和80 m条件下,扬水曝气器外围的入口顺时针环流半径分别扩大8.3%和21.4%,核心控藻区域半径分别增加3.0%和22.2%,核心控藻区域面积分别增加0.6%和5.4%,藻类完全混合的时间分别延长11.1%和15.4%。扬水曝气器更适宜于深水型分层湖库原位控藻。
Water-lifting aeration is an innovative and effective technology for eutrophication control of lakes and reservoirs. Using different outlet configurations of a water-lifting aerator, fields of velocity and algae concentration outside an aerator were numerically simulated with Fluent,simulated results of velocities and algae concentrations agreed well with the measured ones. Under the typical air flowrate of 25 m3/h, the impulse forces acting on water-lifting aerator with different outlet configurations were computed with the momentum equation. The calculated results showed that the maximum impulse force acting on an aerator was reduced by 46.4 % using the optimized outlet configuration with side holes and a baffle plate, the maximum impulse force increased with the peak inlet velocity but not non-linearly. Using optimized outlet config-uration, under the typical water depths of 55 m and 80 m, the radii of the clockwise circulation flow near the water-lifting aerator were enlarged by 8.3% and 21.4% respectively,the radii of the core algae inhibition zone were increased by 3.0 % and 22.2 % respectively, the areas of the core algae inhibition zone were increased by 0.6 % and 5.4 % respectively, and the times required for complete mixing of algae were extended by 11.1 % and 15.4 % respectively. Water-lifting aerators are more suitable for insitu algae inhi-bition in deep stratified lakes and reservoirs.
出处
《水利学报》
EI
CSCD
北大核心
2014年第7期858-866,共9页
Journal of Hydraulic Engineering
基金
国家科技支撑计划课题(2012BAC04B02)
国家自然科学基金资助项目(51178379
51278404)
陕西省社发攻关计划(2010K11-02-03)
教育部高等学校博士点专项科研基金(20106120120012)
西安建筑科技大学人才科技基金(RC1130)
关键词
扬水曝气
出流结构
冲击力
控藻
分层湖库
Water-lifting aeration
outlet configuration
impulse force
algae inhibition
stratified lakes and reservoirs
