| Turbines are the cleanest and most indispensable hydropower equipment in the hydropower industry.There are many rivers in China and abundant hydropower resources,ranking first in the world.Turbines are undoubtedly important equipment in the modern society that vigorously pursues clean and renewable energy.The level of technology is closely related to the development level of China's power industry.Driven by the strong demand for electricity in my country,my country's water turbine and auxiliary machinery manufacturing industry has entered a period of rapid development,the economic scale and technical level have been significantly improved,and the turbine manufacturing technology has ranked among the forefront of the world.Turbine movable guide vanes have the greatest impact on performance in the overall structure,and its opening can change the flow rate.When rotating within the guide vane opening range,there will be different vertical angle deviations at various rotation angles due to manufacturing accuracy,and this deviation will affect the wake.Generally,the turbine is equipped with 16-24 movable guide vanes,and the wake change caused by the cumulative vertical deviation of each guide vane will have a greater impact on the overall efficiency of the turbine.In addition,the hydraulic loss caused by the gap between the movable guide vane and the fixed disk also accounts for the vast majority of the hydraulic loss of the entire turbine,so the overall efficiency improvement resulting from the correction of the position and posture of each guide vane is considerable.Through the establishment of related mathematical models of geometric tolerances and dimensional errors noted by engineering icons,rely on the application program interface provided by Solid Works to collect the size and tolerance data of the turbine assembly,and the assemble ability through the mathematical models of related dimensions Analysis.The establishment of the relevant mathematical model is based on the combination of the new generation GPS theoretical system and the small rotation displacement theory.The three-position coupling of the coordinate transformation at each key coordination point is carried out through homogeneous coordinate transformation.Evaluation of virtual assembly.The key element in the assembly of each turbine guide vane is the assembly of the three shaft holes.Among them,the transition shafts near the upper and lower sides of the guide vanes are transition fits,and the other is the clearance fit.The posture of the leaves has a direct effect.By analyzing the cylindricity and coaxiality data of each guide vane measured by the factory,the actual axis of each guide vane is fitted,and the position and posture of the ideal axis is replaced for further mathematical analysis.Simultaneously analyze the cylindricity and concentricity while simulating the guide vane processing data.In addition to analyzing the processed guide vanes,conduct data simulation on the guide vanes produced in the future factory.Opinion optimization.According to the analysis of the actual guide vane data,the best hole shaft matching is optimized,and the best overall matching state is achieved without repairing,and the overall efficiency of the turbine is improved.By fitting the actual measurement data of the shaft hole,an interference grid model is established,a mechanical model is established according to each linkage device,and the direction of the thrust or pulling force of each guide vane at different angles of the turntable is analyzed.Combined with the direction of the guide vane at various angles,the actual axis position and the grid model,a three-point contact interference analysis was performed to obtain the actual axis rotation-pose curve of the guide vane.All guide vanes are analyzed to obtain the optimal hole-shaft matching number through the optimal matching algorithm,so as to maximize the efficiency of the turbine and achieve the purpose of virtual assembly. |
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