Optimization And Analysis Of Turbine Stator Structure Of Underground Turbogenerator

Underground turbine power generation is a technology that uses mud drilling fluid as the power source to drive the turbine rotor to rotate and generate current to provide electrical energy for downhole instruments,achieving the conversion of drilling fluid energy into mechanical and electrical energy.Compared with traditional battery pack power supply methods,it has advantages such as drilling fluid energy recycling and long-term power supply.Under the support of the project entrusted by the university enterprise cooperation,this paper focuses on the sidetracking of old wells in Changqing oil field Φ The problem of power supply for downhole instruments in 118 mm slim hole drilling is studied,with a small-scale downhole mud turbine generator as the research object.The overall structure design of the generator and the structural design of the guide wheel and turbine are carried out,and the performance of the generator under different working conditions and structural parameters is simulated and analyzed,as well as multi-parameter optimization matching research.This can provide reference for the design and practical engineering application of small-scale downhole turbine generators.The main research content is as follows :(1)Based on the working principle of turbine generator and turbine flow mechanism,the force analysis of cascade airfoil model is carried out to determine the performance parameters of turbine guide wheel.The downhole flow model is determined according to the Reynolds number.It provides a theoretical basis for the subsequent design and analysis of small size turbine generators.(2)Based on the principle of downhole turbine generator and fluid theory,combined with the actual application conditions of the tool,the main technical parameters of small size turbine generator are determined.The overall scheme of the turbine generator and the structural design of the turbine and guide wheel blades are completed,and the mechanical strength(statics)and kinematics of the turbine generator are analyzed.The results show that the designed small size turbine generator has reasonable structure design and reliable working performance,which meets the expected design requirements.(3)The flow field simulation and performance analysis of downhole turbine generator are completed based on CFD.Through the single factor test of the turbine guide wheel,the performance curves of the corresponding speed and pressure difference are obtained.On this basis,the influence of different structural parameters on efficiency is obtained.At the same time,the working performance of the turbine guide wheel under variable working conditions is analyzed,which provides qualitative and quantitative rules and data support for the optimization of tool functional components and overall performance.(4)In order to improve the working efficiency of the turbine guide wheel,the response surface method is used to optimize the different structural parameters of the turbine guide wheel.The CFD single factor test simulation results are used as the analysis data,and the significance analysis is carried out.By defining the objective function,the response surface is reconstructed to obtain the fitting equation.Based on the ternary quadratic fitting equation obtained by the response surface method,the genetic algorithm optimization is completed.The optimization method and results can provide reference for the practical application of downhole turbine generator.