基于CFD的袋式除尘器流场优化及漏袋模拟

基于计算流体力学（CFD），对苏州某环保公司实验用下进风袋式除尘器4种方案下的流场模拟结果进行分析比较，分别为无导流板（方案1）、直板加同向翼板（方案2）、直板加异向翼板（方案3）、竖直导流板加整流格栅（方案4），选取滤袋进口前100 mm处截面速度相对标准偏差作为评价指标，并对不同面积破袋情况进行数值模拟，研究压差、流速和浓度作为检漏特征因子的可行性。结果表明:方案4的流场分布最为均匀，优于方案2和3；方案2的阻力增幅最小，显著低于方案3和4。研究从模拟角度验证了小范围破袋出口浓度与破袋面积呈线性正相关，并发现选取压差和流速作为检漏特征因子影响不显著，浓度变化最为灵敏。综合气流分布均匀性和阻力2个重要评价指标，方案2、4速度均匀性指数分别为0.36、0.2，且方案2阻力增幅远小于方案4，方案2更具实用性。研究提供的数值模拟方案可为下进风袋式除尘器的导流板布置及监测传感器的选用提供一定的参考依据。

CFD-BASED FLOW FIELD OPTIMIZATION AND BAG LEAKAGE SIMULATION OF FABRIC BAGHOUSE FILTERS

Based on computational fluid dynamics (CFD), the flow field simulation results of four schemes of a Suzhou environmental protection company's experimental downdraft fabric baghouse filter were analyzed and compared, in no deflector (scheme 1), straight plate with isotropic wing plate (scheme 2), straight plate with anisotropic wing plate (scheme 3), and vertical deflector with rectifier grille (scheme 4). The relative standard deviation of cross-sectional velocity at the first 100 mm of the bag inlet was selected as the evaluation index. The feasibility of differential pressure, flow velocity and concentration as the characteristic factors for leak detection was studied by numerical simulation of bag breakage in different areas. The results showed that the flow field distribution of scheme 4 was the most uniformed, better than schemes 2 and 3; scheme 2 had the smallest resistance increase, significantly lower than schemes 3 and 4. The study verified that the small-scale broken bag outlet concentration was linearly positively correlated with the broken bag area through simulation, and found that the pressure difference and flow rate, as the characteristic factors of leak detection, had no significant effect, and the concentration change was the most sensitive. Combined with the two important evaluation indicators of airflow distribution uniformity and resistance, the speed uniformity index of scheme 2 was 0.36, the speed uniformity index of scheme 4 was 0.2, the increase of resistance of scheme 2 was much smaller than that of scheme 4, and scheme 2 was more practical. The numerical simulation scheme provided in this paper could provide a certain reference for the distribution of the deflector plate of the lower intake bag filter and the selection of the monitoring sensor.