【摘要】 为了满足国六排放法规中新增的对颗粒物数量监测的要求，亟需提出一种适应柴油机排放环境的具有优良准确性和实时相应性的颗粒物测量技术。介绍了一种漏电流式颗粒物传感器，该传感器使用文丘里管结构吸收颗粒物，通过内部浓度测试区内荷电的颗粒物产生的漏电流描述颗粒物浓度。为解决传感器内部颗粒物沉积导致传感器测量精度下降的问题，需要了解颗粒物在传感器内的运动规律及沉积方式，故开展了流场等场域在传感器内分布规律的模拟研究。通过颗粒物沉积方式受各场域分布影响的模拟结果得出颗粒物沉降机制。研究结果显示：温度的升高直接导致3种沉积速度增大；同时，废气流速对3种沉积速度的影响不一，电泳与惯性碰撞沉积速度都与废气流速呈正相关，而热泳沉积速度与之呈相反趋势。更多还原

【Abstract】 In order to meet the new requirements of particulate matter quantity monitoring in the sixth national emission regulations, it is urgent to put forward a particulate matter measurement technology with excellent accuracy and real-time correspondence adapted to the diesel engine emission environment. This paper introduces a kind of leakage current particle sensor, which uses venturi tube structure to absorb particles, and describes the value of particle concentration by the leakage current generated by charged particles in the internal concentration test area. In order to solve the problem of sensor measurement drop caused by particle deposition inside the sensor, it is necessary to understand the movement law and deposition mode of particles in the sensor, so the simulation study of the distribution law of flow field and other fields in the sensor is carried out. Based on the simulation results, the influence of particle deposition mode on the distribution of each field is studied, and the mechanism of particle deposition is obtained. The results show that the increase of temperature directly leads to the increase of three deposition rates. At the same time, the gas velocity has different effects on the three kinds of deposition velocity. The deposition velocity of electrophoretic and inertial collision is positively correlated with the gas velocity, while the deposition velocity of thermal swimming shows an opposite trend.更多还原