Research On Machining Technology Of Super Large Turbine Top Cover

The structure of hydraulic turbine roof cover is complex and diverse.Most of the roof cover is welded.Special materials such as stainless steel are used in key parts.Therefore,there are some problems such as difficult processing and long processing cycle.Because of its large volume and heavy weight,the top cover of super-large hydraulic turbines is designed as a four-lobe structure,which makes the manufacture of the top cover more difficult.Aiming at the top cover of hydraulic turbine,this paper first makes a general analysis of the parts of the top cover.According to its structural characteristics,this paper briefly introduces several kinds of top cover,such as the integral top cover,the split top cover(the open top cover),the four-lobe top cover and so on.It also makes some analysis and discussion on the structural technicality and manufacturing technicality of the various top cover.The common quality problems of top cover parts in processing are analyzed,and the solutions are put forward.After making a general study and evaluation on the manufacturing process of the hydraulic turbine top cover,the typical top cover-Baihetan hydraulic turbine top cover is selected as the research object,and the manufacturing process and production demand of the top cover are comprehensively evaluated and studied.It is necessary to ensure the qualified manufacturing of the product,meet the requirements of processing accuracy and match properly.Front workshop process layout,to meet the delivery cycle.In this paper,the top cover of Baihetan super-large turbine is taken as the research carrier.The following aspects are studied:(1)Through the analysis of the structure and technology of the top cover of all hydraulic turbines,the common characteristics and differences of the top cover of all hydraulic turbines are analyzed.(2)Structural analysis and process analysis of the four-lobe top cover of large-scale hydraulic turbines show that the four-lobe top cover has higher processing accuracy,more complex process route,larger structure volume,longer processing cycle and more uncontrollable factors in processing.By dividing the process stages and adopting the centralization and dispersion of the process,the process route is worked out to analyze the process characteristics of the four-lobe top cover.(3)Analyse and count the quality problems often encountered in the process of roof cover,and formulate relevant measures to prevent quality problems.(4)Based on the research and analysis of the manufacturing technology of the super-large hydraulic turbine roof,Baihetan Hydropower Station,the detailed processing scheme is formulated,the processing technology and production are comprehensively evaluated and studied,and the key process is worked out.(5)Making scientific and reasonable technological plan,making a careful demonstration of the key process difficulties and processing technology,aiming at ensuring the processing accuracy,improving the processing efficiency and shortening the processing cycle.Ensure that the top cover is transferred to the next workshop according to the time node to participate in the assembly.(6)Through the research of Baihetan turbine roof processing technology,it can be applied in Baihetan Hydropower Station No.1 roof to prevent similar quality problems from happening again.