Analysis And Research On Dynamic Characteristics And Structure Optimization Of HS210 Sand Screw Conveyer

With the large-scale development of shale gas,fracturing is one of the main methods and effective measures for drilling gas production.The performance of fracturing fluid plays a key role in the fracturing process,and fracturing sand,as one of the components of fracturing fluid,mainly supports the fractures formed in the reservoir and is beneficial to improve the permeability of shale.The spiral sand conveyer is not only used to transport fracturing sand for the preparation of fracturing fluid,but also an important part of the sand conveying system in the sand mixer.Therefore,the study on the conveying performance of the spiral sand conveyor can not only improve the conveying efficiency,but also ensure the stability of the mass flow rate of the spiral sand conveyor.This paper takes the HS210 spiral sand conveyor as the research object,introduces its structure and working principle,and analyzes the main technical parameters of the sand conveyor by using continuum mechanics and classical granular mechanics.The discrete element method is used to simulate the fracturing sand transportation process.In view of the factors affecting the conveying efficiency,the structure parameters are studied,which provides a theoretical reference for improving the conveying efficiency and calculating the mass flow rate of the spiral sand conveyor.Specific research contents are as follows:1.Firstly,the structure and main technical parameters of HS210 spiral sand conveyor are determined,and the parameters affecting the conveying performance are analyzed preliminarily.According to the current mechanical industry standard,the evaluation index of conveying performance of spiral sand conveyor is determined.2.Secondly,the simulation parameters of fracturing sand are calibrated by using the accumulation angle test of fracturing sand and the discrete element software EDEM,combining the physical experiment with the simulation experiment.The transport process of sand auger was studied by DEM method.The velocity variation of fracturing sand,mass flow rate and torque of screw shaft in sand auger were analyzed by changing the inclination angle and rotation speed of screw shaft,and the law of the variation with rotation speed and inclination angle was obtained.3.Then,the motion characteristics of gas-solid two-phase spiral flow in spiral sand conveyor are analyzed by CFD-DEM coupling method.By comparing the calculation results of DEM method and CFD-DEM coupling method,the transportation law of spiral sand conveyor under the two calculation methods is obtained respectively,so as to verify the feasibility of DEM method to simulate the transportation process and the accuracy of simulation results.4.At last,the mathematical model of the optimization of the structure parameters of the sand screw conveyor is established,and the objective function and constraint conditions are determined.The structure parameters of the sand screw conveyor are optimized by using the NSGA-Ⅱ multi-objective optimization method,and the conveying efficiency of the optimized sand screw conveyor is obtained.In this paper,the HS210 sand screw conveyor is taken as the research object,and the discrete element method and multi-objective optimization method are used to provide a theoretical basis for the design and improvement of the sand screw conveyor,and to lay a certain research foundation for the efficient exploitation of shale gas.