Caculation And Analysis Of Fish Passing Ability Of Jiangdu Pump Station

As the source pump station in east route of South-to-North Water Diversion Project, JiangDu Pump Station plays a crucial role in irrigation, drainage and hydro-electric power in the area. The construction of the pump station not only meets the demand of pumping but also attaches great importance to ecological protection, i.e. setting up special passage for fish passing easily. However, there is no study conducted about fish passing ability in the pump unit. In this paper, the blade strike model is adopted to do computational analysis of the fish passing ability in JinagDu Pump Station and CFD is used to analyze the effect of the internal flow regime in 3rd JiangDu Pump Station on fish passing ability.Within the scope of the domestic and foreign experimental species of fish, there are analyses showing that the measured mortality of eels is not in conformity with values of model calculation and the rest of the species is suitable for the theory of blade strike model. In this paper, the computational analysis shows that the primary cause of fish injury and death in JiangDu Pump Station is the cutting of the wheel and the injury caused by guide vane is less, that within the scope of the operation flow rate, the fish passing ability of 4th Station is highest and 3rd Station is lowest and at the design point, the mortality rate of 50 mm fish of 4th Station is 9.5%, i.e.4.8% less than the 1st and 2nd Station and 6.7% less than 3rd Station, that with the same efficiency or at the operating point with the Head that needed, the bigger the angle of installation of the blade is, the smaller the fish mortality is, namely,1st and 2nd Stations have the greatest fish passing ability and their angle of installation of blade is +6 °, while 3rd and 4th Stations have+ 4° ngle of installation of blade. At the same time, the length of fish also plays am important role in the whole fish passing ability. It is shown in the paper that within the scope of the operation flow rate, the morality ratio offish is the product of the theoretical probability Pth and the mutilation ratio Fmr, when the fish is shorter than 25mm for 1st and 2 nd Station,35mm for 3 rd Station, 43 mm for 4th Station; the morality ratio of fish is equal to be theoretical probability Pth, when the fish is between 25mm and 555mm for 1st and 2nd Station, between 35mm and 413mm for 3 rd Station, between 43mm and 745mm for 4th Station; the morality ratio of fish is 100%,when the fish is longer than 555mm for 1st and 2nd Station,413mm for 3rd Station,745mm for 4th Station.UG software is used to set 3D modeling of the 3rd Station and ANSYS CFX is adopted to do computational analysis of the effect of internal flow regime of the pump on the fish passing ability. The results show that the damaged section by shearing strain rate is mainly located at the interface of liquid and vane wheel or impeller and the small and thin surface seldom cause any hurt to fish, that the most distinct pressure fluctuated vane wheel causes more damage to physostomes than to physoclistes, but on the whole, the passing time is short and damage is rare for fish.