摘要
本文根据某些引黄泵站工程泥沙对渠道淤积、水泵磨损资料的分析研究，提出本工程泥沙处理的标准。对渠首取水减沙的工程对沉沙条渠进行有沉有冲的动态运行分析研究，取得了延长沉沙条渠使用寿命的效果。提出避沙、减沙、用沙的综合处理泥沙对策。
The Langdian pump station,which lifts water from the Yellow River for the purpose of supplying water for irrigation of 144 000 hm 2 downstream,is located in Linyi County,the south of Shanxi Province.The total pumping capacity is 42.9m 3/s with a total installed capacity of 3 550 kw.The pumping lifts being 4m. For the constrution of the pump station,two problems should be considered:\ 1)Abrasion problem on the pumps;2)Sedimentation problem in the canals.According to the analysis concerning these two problems,the writer found that both the problems have been due almost entirely to the impact of the coarse sand contained in the sediment laden water of the Yellow River.The analysis on the abrasion problem shows that the coarser the sand grain size and the higher the circular velocity Vd of the impeller for the same sand grain size,the more serious is the abrasion on the pumps,however,the abrasion is not so serious when the sand grain size is reduced to a certain degree,although the circular velocity Vd remains high.The analysis on the sedimention problem in the canals shows that in the upper reaches of the main canals,the bed sediment load of grain size greater than 0.05mm occupies about 87%￣97% in weight of the sample taken from the field and the suspended load of the same grain size occupies about 23%￣26.8%.The coarse sand that has silted in the canal has a remarkable effects upon the sediment carrying capacity (kg/m 3) of the canal,with the discharge being constant.Therefore,the writer offered a suggestion that the coarse sand that has grain size greater than 0.05mm,as a sediment treating criterion,should be removed as much as possible at the flood plain ustream of the pump station,and offered a comprehensive sediment treating,that is the sediment removing measures including the following contents:1)To avoid diverting water during the period when the sediment content thereof is greater than 50kg/m 3;\ 2)To reduce the sand by setting up the stop-log gate at the water intake to change the underflow into the overflow.The hydraulic test indicated that this measures show a better effect;\ 3)To set the strip desilting channels in the flood plain downstream of the intake and upstream of the pump station.Adopting a “silting and flashing alternate operating method”to prolong their life time.
出处
《山西水利科技》
1998年第3期42-49,共8页
Shanxi Hydrotechnics
