抽吸式地震救援机特大颗粒负压输送数值模拟

Numerical Simulation of Negative Pressure Transport of Extra Large Particles of Suction Earthquake Rescue Machine

针对某抽吸式地震救援机气力输送系统工作时存在的易堵塞和能耗高等问题,选用不同输送管径开展特大颗粒物料气固两相流数值模拟,研究风机以额定功率工作时特大颗粒在不同管道中的运动特性和管道内压损失。利用计算流体力学和离散单元法进行耦合求解,在传统耦合接口的基础上更改体积分数算法实现颗粒粒径大于流体域网格单元的气力输送数值仿真,利用软件Fluent进行连续相气体的流动分析和曳力计算,利用软件EDEM进行离散相颗粒的受力分析和运动轨迹计算。研究结果表明,管径为280 mm的管道输送性能最佳,管中颗粒运动速度最大为7.1 m/s,0~25 s内的运输量达66.4 kg,管道内压损失在5.5 s时达到稳定,为3.04 kPa,与试验结果基本吻合,可为抽吸式地震救援机气力输送系统设计和优化提供参考。

Aiming at the problems of easy blockage and high energy consumption in the pneumatic conveying system of a pneumatic suction seismic rescue machine,the gas-solid two-phase flow of large particles in different pipes with different diameters was numerically simulated to study the movement characteristics and pressure loss of large particles in different pipes when the fan works at rated power.Computational fluid mechanics and discrete element method were used to solve the coupling,and the volume fraction algorithm was changed on the basis of the traditional coupling interface to realize the numerical simulation of pneumatic conveying with the particle size larger than the fluid domain grid element.The flow analysis and drag calculation of continuous phase gas were carried out by using the software Fluent.The force analysis and motion trajectory calculation of discrete phase particles are carried out by using Edem software.The results show that the pipe with a diameter of 280 mm has the best transport performance,the particle movement velocity in the pipe is up to 7.1 m/s,the transport volume within 0~25 s is up to 66.4 kg,and the pressure loss in the pipe reaches a stable level of 3.04 kPa at 5.5 s,which is basically consistent with the test results.It can provide reference for the design and optimization of pneumatic conveying system of suction earthquake rescue aircraft.