多翼离心换气扇CFD模拟及参数优化

发布时间：2018-04-14 16:08

本文选题：多翼离心换气扇 + CFD模拟　；参考：《华中科技大学》2012年硕士论文

【摘要】：本课题来源于广东省产学研项目“新型高效节能低噪型换气扇的开发及产业化”（编号2010B090400446），多翼离心风机和普通离心风机相比具有大轮径比，流量系数大，噪声低等优点，广泛应用于厨房、宾馆酒楼等通风换气及抽油烟机和空调行业。但其效率较低，换气扇的能耗在建筑通风和空调行业耗能的比重比较大，所以提高多翼离心风机的性能具有十分重要的意义。另外采用传统的研究方法，则会增加产品开发代价和开发时间，因此基于CFD数值模拟成为研究多翼离心风机的一个重要方法。本文以某型号多翼离心换气扇为研究对象，并对多翼离心换气扇模型进行改造，在GAMBIT中对换气扇模型和改造后的模型进行处理和网格划分，，用FLUENT对该多翼离心换气扇进行模拟计算，并通过试验验证了此计算方法的适用性。对换气扇某工况下的流动进行了具体的分析研究。结果表明：在叶轮的前盘位置附近处，存在有明显的回流现象，在进气栅内的边缘处也存在有明显的漩涡现象，对叶轮进出口和蜗壳内部流动的研究也表明换气扇内部流动情况非常复杂。对大小流量两种工况的流动进行了对比分析，结果表明在小流量工况下蜗壳蜗舌附近位置处回流现象比大流量下的要严重。文中对多翼离心换气扇进气格栅、叶片数目和蜗壳进行优化，并进行了相同的数值计算。结果显示：原模型的进气流分布不均匀，方形和圆形进气格栅的性能要优于原格栅；对叶片数目的计算结果表明叶片数取44时，流道中漩涡区较小且和原模型的性能相当；对叶轮安装位置的改进表明：原有换气扇叶轮中心和蜗壳的相对位置不是最佳位置，优化后的蜗壳与叶轮的相对位置使换气扇的压力提高。噪声是换气扇的一个很重要的参数，噪声的大小直接决定着换气扇的优劣。本文对噪声利用噪声测量仪进行了测量，得到了指定接收点位置的噪声级大小。
[Abstract]:This subject comes from the project "Development and industrialization of a new type of ventilator with high efficiency, energy saving and low noise" (No. 2010B090400446). Compared with ordinary centrifugal fan, multi-wing centrifugal fan has the advantages of large ratio of wheel diameter, large flow coefficient, low noise and so on.Widely used in kitchen, hotel restaurants and other ventilation and range hood and air conditioning industry.But its efficiency is low, and the energy consumption of ventilator is large in the building ventilation and air conditioning industry, so it is very important to improve the performance of multi-wing centrifugal fan.In addition, the traditional research method will increase the cost and time of product development, so numerical simulation based on CFD has become an important method to study multi-wing centrifugal fan.In this paper, a certain type of multi-wing centrifugal fan is taken as the research object, and the model of the multi-wing centrifugal ventilator is modified. The model of the fan and the modified model are processed and meshed in GAMBIT.The multi-wing centrifugal fan is simulated and calculated by FLUENT, and the applicability of the method is verified by experiments.The flow of the ventilator under a certain working condition is analyzed and studied in detail.The results show that there is an obvious backflow phenomenon near the front disc of the impeller and an obvious swirl phenomenon at the edge of the inlet grid.The study of the impeller inlet and outlet and the flow inside the volute also shows that the flow inside the ventilator is very complicated.The flow around the cochlea tongue of the volute is more serious under the small flow condition than the one under the large flow rate. The results show that the flow around the cochlea tongue of the volute case is more serious than that at the large flow rate.In this paper, the intake grille, blade number and volute of multi-wing centrifugal ventilator are optimized, and the same numerical calculation is carried out.The results show that the inlet flow distribution of the original model is uneven, and the performance of the square and circular intake grille is better than that of the original grille, and the calculation results of the number of blades show that the swirl region in the flow channel is smaller and the performance is similar to that of the original model when the number of blades is 44.The improvement of the impeller mounting position shows that the relative position of the original fan impeller center and volute is not the optimal position, and the relative position of the optimized volute and impeller increases the pressure of the ventilator.Noise is an important parameter of ventilator, and the magnitude of noise directly determines the quality of ventilator.In this paper, the noise is measured by using the noise measuring instrument, and the noise level of the designated receiving point is obtained.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH432;TU834.4

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