| High power hydraulic coupling is an important speed regulating device to match the main feed water pump of large nuclear / thermal power station boiler.Compared with the advanced technology of foreign similar products,China has not formed the R & D capability of high-power hydraulic coupling independently.As the three working impellers of high-power hydraulic coupling,pump wheel,turbine and turbine cover are the core components of power transmission.The working impeller is affected by centrifugal load and fluid load when it works.If it is damaged,it will directly cause power transmission failure and seriously affect the stability of power station system.Therefore,to ensure the strength of the impeller of the hydraulic coupling is the key problem in its structural design.In this paper,YOCQ510 high-power hydraulic coupling is taken as the research object.The method of unidirectional fluid structure coupling is used to analyze the strength of impeller assembly,and its dynamic characteristics are studied.The work of this paper provides an effective reference for the impeller structure design of high-power hydraulic coupling.The main research contents and conclusions are as follows.1.Establish and determine the impeller analysis model of high-power hydraulic couplingTaking YOCQ510 high-power hydraulic coupling as the research object,the geometric model of impeller and flow channel of high-power hydraulic coupling is established,and the high-precision hexahedral mesh model is divided,and the grid independence is verified.Combined with the pressure flow field distribution trend of pump wheel,turbine and its blade under three typical working conditions,the screw connection is determined by comparing three different connection schemes The whole assembly model is taken as the research object.2.Strength analysis of impeller assembly of high power hydraulic couplingThe strength of high-power hydraulic coupling is comprehensively analyzed by using the unidirectional fluid structure coupling method.By comparing the deformation and stress of the assembly under full liquid filling condition and partial liquid filling condition,it is concluded that the maximum deformation position of the assembly assembly assembly occurs at the inner edge of the turbine casing,and the maximum deformation of the pump blade occurs at the blade outlet Compared with the damage pictures of impeller blades,the two are in good agreement.3.Dynamic characteristics analysis of high power hydraulic couplingThe dynamic characteristics of high-power hydraulic coupling are studied by means of assembly modal analysis method with prestressing force.The vibration characteristics of working impeller under different conditions of liquid filling rate and speed ratio are analyzed,and the exciting frequency range of impeller in actual work is obtained.In conclusion,the stress and deformation results of impeller assembly of highpower hydraulic coupling obtained by unidirectional fluid structure coupling method are reliable and effective,and the calculation results have high accuracy.The modal analysis with prestressing force can be used as the basis of structural vibration prediction of high-power hydraulic coupling.The work of this paper has a certain guiding significance for the structural design of high-power hydraulic coupling impeller. |
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