旋转阀气力输送空气泄漏特性仿真

Simulation of air leakage characteristics of rotary valve pneumatic conveying

为分析旋转阀气力输送的空气泄漏特性和流场变化规律,基于Fluent软件,采用非定常计算,建立旋转阀气力输送系统二维、三维计算模型,对某型旋转阀气力输送系统在纯送风工况下进行数值模拟,研究不同时刻旋转阀气力输送系统的压力分布与空气泄漏量,并对比二维与三维计算模型泄气量的变化规律,获得叶顶间隙、进出口压差对旋转阀泄气量的影响规律.数值计算得到的不同压差下旋转阀泄气量与试验结果对比显示,两者最大相对误差为12.2%,平均相对误差为8.7%.研究表明,二维与三维计算模型的泄气量随旋转时间变化趋势一致,二者平均泄气量偏差为9.8%;旋转阀平均泄气量、高压腔体瞬间泄气量与进出口压差呈线性关系;旋转阀高压腔体瞬间泄气量随叶顶间隙尺寸变化很小,而旋转阀平均泄气量随叶顶间隙呈指数趋势增长.

In order to analyze the air leakage characteristics and flow field variation law of rotary valve pneumatic conveying system,based on FLUENT software,the two-dimensional and three-dimensional models of rotary valve pneumatic conveying system were established by using unsteady calculation,and numerical simulation of a rotary valve pneumatic conveying system under pure air supply condition was carried out.The pressure distribution and air leakage of rotary valve pneumatic conveying system at different times were studied,and the variation law of air leakage of two-dimensional and three-dimensional calculation models was compared.The influence of tip clearance and pressure difference between inlet and outlet on gas leakage of rotary valve was obtained.Compared with the experimental results,the gas leakage rate of rotary valve under different pressure difference obtained by numerical calculation shows that the maximum relative error is 12.2%,and the average relative error is 8.7%.The results show that the gas leakage rate of two-dimensional and three-dimensional models has the same trend with rotation time,and the average deviation of the two models is 9.8%.The average air leakage of the rotary valve and the instantaneous air leakage of the high-pressure chamber increase linearly with the pressure difference between the inlet and the outlet,while the instantaneous air leakage of the high-pressure chamber of the rotary valve changes little with the size of tip clearance,and the average air leakage of the rotary valve increases exponentially with the tip clearance.