粉尘浓度对20L球罐内硫磺粉尘分散过程流场特性的影响

Influence of dust concentration on flow field characteristics of sulfur dust during dispersion process in 20L spherical tank

为了解不同浓度的硫磺粉尘在20 L球罐内分散过程流场特性的变化规律,采用CFD数值模拟方法再现球罐内硫磺粉尘分散过程,揭示粉尘浓度与湍流动能、流场速度、粉尘云浓度、最佳点火延迟时间之间的关系。研究结果表明:在其他条件一定时,喷入的粉尘越少,球罐内湍流动能和流场速度的峰值越大,球心处的粉尘云等效浓度的峰值越小,粉尘颗粒滞留在球心处的时间越短,即粉尘浓度越小,最佳点火延迟时间段越小;粒径为163μm、浓度为0.15,0.3,0.45 kg/m3的硫磺粉尘对应的最佳点火延迟时间分别是50~60,50~85,50~105 ms。

To understand the variation laws of the flow field characteristics of sulfur dust with different concentrations during the dispersion process in the 20 L spherical tank,the dispersion process of sulfur dust in the spherical tank was reappeared by using the CFD numerical simulation method,and the relationship between the dust concentration and the turbulent kinetic energy,flow field velocity,dust cloud concentration and optimum ignition delay time were revealed. The results showed that when the other conditions were constant,the less the sprayed dust,the greater the peak values of the turbulent kinetic energy and the flow field velocity in the spherical tank,the smaller the peak value of the equivalent concentration of dust cloud at the spherical centre,and the shorter the time of the dust particles detained at the spherical centre,namely the smaller the dust concentration,the smaller the optimum ignition delay time. When the concentration of sulfur dust with the particle size of 163 μm was 0. 15 kg/m^3,0. 3 kg/m^3 and 0. 45 kg/m^3,the corresponding optimum ignition delay time was 50-60 ms,50-85 ms and 50-105 ms respectively.