Analysis And Optimization Design Of Steam Turbine DEH Piping System

The anti-fuel pipeline of the steam turbine DEH system is an important part of the system.The fluid interacts with the pipe through fluid-structure interaction(FSI),and the pipe system may vibrate when it is subjected to the impact of the fluid which can lead to pipeline fatigue damage.The layout design of the oil pipeline has important influence on the safety and life of the system.Therefore,it is important to carry on dynamic characteristic analysis and optimize design of the oil pipeline system.Based on the study of FSI,the oil pipeline system is simulated and analyzed in the time domain and frequency domain respectively.What’s more,the pipeline software CAESAR II is used to analyze and optimize the design.The main work and research results are shown as follows:(1)In the time domain,based on the mass conservation and momentum conservation equations,the modeling of anti-fuel pipeline and the emulation analysis by the one-way method of characteristics(MOC)are completed.The optimal design method of piping system parameters is given by combining with the genetic algorithms.Considering the two-way FSI,the simulation analysis of the MOC is carried out.Compared with the one-way FSI,the validity of the one-way FSI in pipeline analysis is verified.(2)In the frequency domain,the transfer matrix method(TMM)is used to conduct the modeling and simulation of the straight pipe in the piping system and the validity of the MOC is verified.The frequency response of the relevant parameters is obtained,and the natural frequencies of the pipeline and the related vibration modes are calculated to prevent resonance in the system.(3)In CAESAR II,the modeling and simulation of elbow section are carried out.The selection of elbow diameter and the optimal design of support and hanger are carried out.The validity of the TMM in the analysis is verified.