Dynamic Simulation Research Of Ship Propulsion System Under Fast Paralleling And Splitting Conditions

Combined gas turbine and gas turbine(COGAG)power plant has been paid more and more attention by the navies of various countries due to its two significant advantages of high power density and fast starting speed.Usually,the paralleling of gas turbines is carried out under the condition of stable changes in speed and load,but in the face of some emergencies,it is necessary to quickly parallelize to increase the power or quickly split when a gas turbine fails.Gas turbines need to be quickly paralled or splitted.Due to the sudden paralleling or splitting of the gas turbine,the propulsion system must have a sudden load,which will have an impact on the entire system.Based on a major special basic research project,this paper takes the COGAG propulsion device as the research object,and carries out the dynamic characteristics simulation of the ship’s propulsion system under the conditions of rapid paralleling and splitting and the contact characteristics of key components.The structural safety design of the COGAG power plant provides theoretical guidance and reference.The main research contents of this paper include the following aspects:(1)Research on modeling and simulation of gas turbine.According to the thermodynamic relationship between the various components of the gas turbine(compressor,combustion chamber,turbine,etc.),the BP neural network method is used to fit the characteristic curves of the compressor and turbine,and the modular modeling method is used in MATLAB/SIMULINK to establish Gas turbine simulation model,and analyze the steady-state and dynamic characteristics of the gas turbine to provide an accurate gas turbine model for subsequent co-simulation.(2)Dynamic simulation research of rear transmission equipment.Based on COGAG power plant simulation test bench,the dynamic simulation model of the SSS clutch and the parallel gearbox was established in the ADAMS software,and the dynamic characteristics of the SSS clutch under different working conditions and the dynamic performance of the parallel gearbox gear train were studied.Provided the correct simulation model for the subsequent study of the dynamic characteristics of the propulsion system and the contact characteristics of key components.(3)Simulation research on dynamic characteristics of ship propulsion system.Using the co-simulation method,an interface was created to connect the SIMULINK model of the gas turbine with the ADAMS middle and rear transmission system model,and the four operating conditions of fast paralleling and fast splitting were simulated and analyzed,and various parameters(speed,torque,the change law of the collision force,etc.),and compare the simulation results with the test results.The results show that the impact load of the ship’s propulsion system is generated under the condition of rapid paralleling and splitting,which leads to a sudden increase in the collision force at the key parts of the SSS clutch and the parallel gearbox,which provides a basis for the finite element analysis of key components.(4)Simulation research on the contact characteristics of key components.Combined with the strength properties of the material and the finite element analysis theory,the contact characteristics of the key components of the rear transmission system are analyzed.In the ANSYS finite element analysis software,the transient dynamics of the contact characteristics of the SSS clutch ratchet and pawl,the middle part and the driving part,the SSS clutch gear pair and the parallel gear box’s gear pair under the maximum impact force during the rapid paralleling process are solved.The stress,strain changes and dangerous positions of key components under the maximum collision force are obtained,so as to judge whether the maximum collision force will cause the structural failure of the key components,and then judge the structural safety of the components under the impact load of rapid paralleling and splitting.