平行流送风对侧吸排风罩烟气捕集效率的提升

在实际工程中，由于排风罩直接与除尘系统相连接，排风罩的大小及流量一经确定后不易更改，且当实际排风量相比设计排风量小很多时，采用传统的设计方法很难得到最优设计参数。因此，如何在排风罩形式及流量确定的情况下合理设计送风口的大小及流量具有很强的现实意义。采用数值模拟的方法，对比研究了不同形式的侧吸排风罩对高温烟气的捕集情况，在此基础上增加送风口，在保证排风流量不变的情况下，对比了不同送风流量对烟气控制效果的影响特性。此外，研究了不同送风末端装置下污染物的捕集效果。结果显示:1）相较于一般侧吸排风罩，采用移动式侧吸排风罩和旋转开闭侧吸排风罩可在一定程度上提高高温烟气的捕集效率，捕集效率最大可提高53%。2）对于通风系统的排风流量确定的情况下，应保证送风气流能将污染物有效输送至排风口处，调整送排风流量比，确定排风量受限情况下最佳送排风流量比，实现烟气捕集效率的提升。3）增设平行流送风装置可最大程度提高送风气流均匀度，从而提高排风罩的烟气捕集效率。研究结论可对实际吹吸式通风装置的改造及设计提供参考。

IMPROVEMENT OF FUME CAPTURE EFFICIENCY OF SIDE SUCTION HOOD WITH PARALLEL-FLOW SUPPLY AIR

In practical engineering, because the exhaust hood was directly connected with the dust removal system, the size and flow of the exhaust hood were not easy to change once determined. When the actual exhaust air volume was much smaller than the exhaust air volume designed by the design method, it was difficult to obtain the optimal design parameters by using the traditional design method. Therefore, reasonable design of the size and flow of air supply outlet under the determined the form and flow of exhaust hood have strong practical significance. In this paper, numerical simulation was used to compare the flow field and the capture of pollutants under different forms of side suction exhaust hood and supply air device. On this basis, the air supply inlet were added, and the capture characteristics of different air supply flow rate on the pollutants were compared under the the constant exhaust flow. In addition, the effects of different air supply terminal devices on the capture of pollutants were studied. The results showed that movable exhaust hood and rotating open and closed exhaust hood could effectively improve the capture efficiency of pollutants. On this basis, the capture efficiency of pollutant could be improved by using air supply inlet, compared with using the exhaust hood alone. It was found that when the exhaust flow of the exhaust hood in the actual project was determined, the ratio of the exhaust flow should be adjusted on the premise that the supply air flow could effectively transport pollutants to the exhaust outlet. Finally, it was found that using parallel flow air supply device could improve the uniformity of air supply, improve the capture efficiency of exhaust hood. The results of the present study could provide certain guidance for the transformation and design of the push pull ventilation device in practical engineering.