基于凸形壁面的虚拟冲击式呼吸性粉尘采样器研究*

为研究满足BMRC曲线的呼吸尘采样器，提高呼吸尘采样的准确性，基于虚拟冲击原理，针对隔离主流和弱流通道壁面的形状，提出1种基于虚拟冲击原理的呼吸尘采样器的改进结构，并对不同模型进行模拟仿真实验，利用Ansys Fluent气-固2相流模拟采样器中的流场，对呼吸性粉尘颗粒在流场内的运动轨迹进行跟踪，对仿真得到的呼吸尘分离效能与BMRC曲线的标准进行对比。结果表明:相比采样器原型和主弱流壁面形状为“凹型”，虚拟冲击式呼吸尘采样器主弱流壁面形状为“凸型”时对呼吸尘采样的效果更好，同时分离效能与BMRC曲线的标准差为δ=2.65%，满足偏差小于等于5%的要求。研究结果可为呼吸尘采样器的优化设计提供参考。

Research on virtual impact respirable dust sampler based on convex wall

In order to study the respirable dust sampler that meets the BMRC curve and improve the accuracy of respirable dust sampling,an improved structure of respirable dust sampler based on the virtual impact principle was proposed according to the wall shape of isolated main flow and weak flow channel based on the virtual impact principle,and the simulation experiments were carried out on different models.The flow field in the sampler was simulated by the gas-solid two-phase flow of ANSYS fluent,then the movement track of respirable dust particles in the flow field was tracked,and the separation efficiency of respirable dust obtained by simulation was compared with the standard of BMRC curve.The results showed that compared with the sampler prototype and the main weak flow wall shape of “concave”,when the main weak flow wall shape of the virtual impact respirable dust sampler was “convex”,the effect of respirable dust sampling was better,and the standard deviation of separation efficiency with BMRC curve was δ=2.65%,which met the requirement of deviation within 5%.It provides reference for improving the design of respirable dust sampler.