Including Sand Water Condition Turbine Spiral Case, Stay Vane Flow Field Analysis And Line Improvement

Prosperous service hydroelectric power station located at the Qinghai Province Tongren County Longwu River basin, because the hydraulic turbine spiral case long time is under the silt impact and the attrition, the spiral case use long-lived surface reduces greatly. This topic from spiral case transformation, but is not whole replacement spiral case angle embarking, is for the purpose of abrading the more serious tip of the nose part through the change spiral case the line to enable the tip of the nose the velocity of flow to have compared to the original design speed reduces, thus achieves reduces the friction loss and abrades, enhances the spiral case performance and the life goal.In view of the prosperous canyon hydroelectric power station HLD74-WJ-88 hydraulic turbine spiral case, the concrete transformation's method is, through two kind of spiral case carries on the geometry modelling to the modification around, adopts the identical grid division method and the Fluent computation parameter establishment, has carried on its interior mobile numerical simulation, after may obtain the modification, which the spiral case exit's fluent fluid state has compared with before the modification to change, tangential velocity, radial velocity along spiral case export highly with arc of contact change rule. After the modification spiral case before the transformation cross section's average tangential velocity compares the concrete size which the modification reduces, after the modification, before the same modification, around the spiral case final stage fluid state's contrast and the modification the spiral case average tangential velocity value leads the empirical formula, after obtaining the improvement spiral case life increase.Main achievement which obtains in this actual project innovation project process, obtains two kind of spiral case through the computation the fluid state and the performance difference draws the conclusion under the same operating mode to be as follows:(1) The flow characteristicsin spiral case is complicated,the new spiral case and the old one do not conform to the formula. V_u·r = K strictly, V_u·r of new spiral case is larger than than the old one in the partφ<102°;(2) average V_u of the new spiral case increase greatly than the old significantly in tail part,the life of new spiral case is 120% longer than the old one,the conclusion drawed frawed from munerical simulatian;(3) the floe angle of the new spiral case increase greatly than the old one in the partφ< 75°, it should change the shap of the stay vane of the new designed spiral case or the clash will be too strong to loss more energe than normal.Moves three year later check result to indicate that the modification the spiral case final stage abrasion situation had obvious reduction, the water power performance has been superior, this modification plan the line repaired or the optimization design for the middle and small scale interflow type hydraulic turbine spiral case has provided the beneficial reference.