Research On Virtual Assembly Technology Of Water Turbine

With the increasing power demand and the increasingly stringent requirements of low-carbon power generation,hydropower has played an indispensable role in green renewable energy power generation,especially in terms of energy storage peak shaving,regional grid stability,energy saving and emission reduction.Therefore,in order to ensure the stability of power grid operation,higher requirements are imposed on the reliability of hydropower generation.As the power equipment of hydropower,hydro turbines,their design,processing,and assembly work have also been subject to high standards and strict management.Among them,the quality of the turbine assembly is directly related to whether the turbine generator can be produced safely and smoothly.Based on the establishment of a scale physical model,a large number of molding tests are performed in the traditional assembly process to complete its design;And most units use two-dimensional technical documents to explain the complicated process flow,which requires professionals to study patiently.It causes that relevant units consume a lot of time in the assembly process,increasing assembly costs,and cannot meet the requirements of related enterprises for information,digitization and agility.Virtual assembly technology provides new ideas for solving the above problems by virtue of its low cost and agility.Different from the traditional assembly mode,the virtual assembly technology such as assembly sequence planning and evaluation is used to predict and evaluate the product assembly process,which can find out the problems in the assembly in advance and evaluate the assembly effect of the product,and enhance the level of decision making and control.Therefore,the goals of optimizing the assembly quality of the turbine,maximizing the assembly efficiency and minimizing the assembly cost are achieved.This subject studies the assembly process of the turbine,based on the virtual assembly technology.It aims to improve the assembly quality of the turbine and maximize the use of assembly resources.It has important practical significance and application value for the realization of the automatic design of the turbine assembly process and the overhaul and assembly management.The main work completed and the results obtained are as follows:1、The virtual assembly information modeling technology for hydraulic turbine is studied.The requirements of virtual assembly information for hydraulic turbines are analyzed,and the assembly information is classified,and the related information expression methods are given.On the basis of meeting the assembly information requirements,a model definition technology for establishing a virtual assembly information model of a hydraulic turbine is proposed,and the definition methods and definition standards of the relevant assembly information in the model are given.It provides an information basis for the subsequent application of data for assembly sequence planning,evaluation,and prototype system development.2、The method of assembly sequence planning for assembly process is studied.Based on the characteristics of differential evolution algorithm such as good robustness,strong global optimization ability and easy implementation,it is introduced into the field of hydraulic turbine assembly sequence planning.The fitness function is constructed with the feasibility of assembly sequence,the number of assembly sequence redirections,the number of assembly tool changes,and the stability of the assembly process as fitness indicators.Aiming at the characteristics of discrete and strong constraints of assembly sequence planning,the algorithm was adaptively improved,and a mutation strategy of genetic algorithm was introduced for the premature maturity of the algorithm.An assembly sequence planning method based on discrete difference genetic algorithm was proposed.The feasibility and stability of the method were proved by the example verification and comparison with genetic algorithm.3、The evaluation method of assembly sequence in the overhaul assembly environment is studied.In order to reasonably evaluate the overhaul assembly sequence of the hydraulic turbine and ensure the correctness of the optimal results of the overhaul assembly sequence,a comprehensive evaluation method of the overhaul assembly sequence based on the fuzzy analytic hierarchy process is proposed.Based on research and expert knowledge,a comprehensive evaluation system for repair and assembly sequences was constructed.According to actual needs,a new type of evaluation index,the overhaul factor,was given.Combined with the remaining six evaluation indicators,under the two evaluation criteria of inspection and assembly time and inspection and assembly weight,a fuzzy analytic hierarchy process is used to comprehensively evaluate the inspection and assembly sequence.4、Design and development of virtual turbine prototype system.The overall scheme of the virtual assembly prototype system of the hydraulic turbine is designed,and two ports of the employee side and the management side are developed for different operators.According to the actual use requirements,the modular design concept is used to develop the functions of each functional module,and the functions of each functional module and sub-functional modules are introduced.The developed system has been applied in practice.