Influence Of Impeller Parameters Of Marine Centrifugal Pump Under Dynamic Pressure Inlet On Hydraulic Characteristics And Optimization Design

Because of its high efficiency,simple structure and reliable operation,centrifugal pump has been widely used in various fields such as aerospace,nuclear power station,urban water supply,petrochemical industry and ships.In ships centrifugal pumps are mainly used in ballast water transfer,domestic water circulation,ship fire-fighting and cooling water systems and other fields.Because of its wide use and important status,the safety and stability and high efficiency of marine centrifugal pumps are especially important.This topic takes the impeller of marine fire fighting centrifugal pump as the research object,solves the internal flow characteristics and hydraulic characteristics parameters of the centrifugal pump by numerical calculation method,establishes the quadratic regression model of efficiency,head and shaft power by response surface analysis based on Box-Behnken test,and optimizes the geometric parameters of the impeller of marine centrifugal pump using multi-objective optimization method.The main research of the paper is as follows.(1)Firstly,the hydraulic calculation of marine fire fighting centrifugal pump based on the similar principle of velocity coefficient method,establish the three-dimensional model of centrifugal pump unit,extract the flow channel to establish the centrifugal pump simulation model,and verify the centrifugal pump simulation model under different flow rates through experiments.(2)Based on the motion characteristics of the ship,set the dynamic pressure inlet of the marine fire fighting centrifugal pump,solve the transient of the centrifugal pump under the dynamic pressure inlet based on numerical simulation,analyze the influence law of the dynamic pressure inlet parameters on the axial force,radial force and internal pressure pulsation of the centrifugal pump,and explore the influence of the dynamic pressure inlet on the internal flow characteristics of the marine centrifugal pump.(3)Through the single-factor analysis of impeller inlet angle,outlet angle,impeller inlet diameter,impeller outlet diameter and impeller outlet width of centrifugal pump,the flow characteristic curve of centrifugal pump is obtained and the influence law of impeller structure parameters on the hydraulic characteristics of centrifugal pump is explored,and the single-factor sensitivity analysis of impeller parameters is carried out to obtain the sensitivity of impeller parameters on the hydraulic characteristics of centrifugal pump.(4)For impeller outlet diameter,inlet diameter and outlet width as variables,the influence law of impeller parameters on centrifugal pump head,shaft power and hydraulic efficiency was obtained by Box-Behnken experimental design,and multiple regression model was established.Based on NSGA-II multi-objective optimization algorithm.With increasing the head and efficiency of marine fire fighting centrifugal pump as the optimization objective,the multi-objective algorithm is used to optimize the impeller outlet diameter,inlet diameter and outlet width of the centrifugal pump,which improves the hydraulic characteristics of the centrifugal pump.