通风系统离心风机蜗壳的优化设计

发布时间：2018-04-28 11:36

本文选题：离心风机蜗壳 + 参数优化　；参考：《沈阳工业大学》2014年硕士论文

【摘要】：为解决通信基站内电子设备发热大问题，通常不间断地使用空调降温，新风节能系统可以引进室外新鲜冷空气降温，减少空调运行时间达到降低能耗效果。离心风机是新风节能系统中进风的主要动力组件，为了提高风机的性能，对离心风机进行了三维流场仿真及气动噪声的预测，针对离心风机蜗壳的效率及结构进行了优化。在对离心风机蜗壳整体设计的基础上，根据已有的叶轮，结合工业风机和空调风机蜗壳的技术要求进行参数计算，考虑蜗舌对风机效率的影响，以蜗舌的半径及蜗舌间隙为参数，通过参数化建模得到多组不同的模型。利用了FLUENT数值模拟软件对离心风机的内部三维流场进行了数值计算，，并对其进行了分析。计算了多组模型离心风机的平均增长率，最终选择蜗舌半径系数0.04，间隙系数0.055为最优模型，比初始风机的效率增长了1.268%。对离心风机气动噪声进行预测，经过计算流体力学(CFD)计算，得到蜗壳表面的偶极子声源，根据FW-H方程的求解，模拟了离心风机在产生的气动噪声，得到入口及出口处监测点的声压级，并通过实验测试进行了验证。蜗壳中蜗舌处的气动噪声为主要声源，其参数的改变对风机的噪声具有一定的影响。由于蜗壳材料使用EPS泡沫板，在大流量下气体的冲击可能导致的蜗型改变甚至疲劳破坏，产生的蜗壳振动还会使蜗壳效率降低、流量下降。为了使风机更加平稳运行，降低蜗壳振动，需要对离心风机蜗壳的整体结构进行优化。使用ANSYSWorkbench协同仿真平台，进行了考虑内部流场和蜗壳振动相互作用的双向流固耦合数值计算，模拟了离心风机蜗壳在受到风机气流非定常压力下的动力响应。在蜗壳的初始设计模型的前盖面使用加强筋加固，加厚蜗舌部分。结果表明，优化后的蜗壳总变形和等效应力都有明显的减少，解决了蜗壳在蜗舌处的应力集中现象，同时有效地改善了风机前盖面和出口处的振动。
[Abstract]:In order to solve the heat problem of electronic equipment in communication base station, air conditioning is usually used uninterruptedly. The fresh air energy saving system can introduce outdoor fresh cold air to cool down, reduce the operating time of air conditioning and reduce energy consumption. Centrifugal fan is the main power component of inlet air in the fresh air energy saving system. In order to improve the performance of the fan, the three-dimensional flow field simulation and aerodynamic noise prediction of the centrifugal fan are carried out, and the efficiency and structure of the spiral case of the centrifugal fan are optimized. On the basis of the whole design of centrifugal fan volute, according to the existing impeller, combined with the technical requirements of industrial fan and air conditioner fan volute, the effect of cochlear tongue on fan efficiency is considered. Taking the radius of cochlear tongue and the gap of cochlear tongue as parameters, many different models were obtained by parameterized modeling. The three-dimensional flow field of centrifugal fan is numerically calculated and analyzed by using FLUENT software. The average growth rate of multi-group centrifugal fan is calculated. Finally, the cochlea radius coefficient 0.04 and the clearance coefficient 0.055 are selected as the optimal model, which increases the efficiency of the initial fan by 1.268%. The aerodynamic noise of centrifugal fan is predicted, and the dipole sound source on the surface of volute is obtained by computational fluid dynamics (CFD) calculation. According to the solution of FW-H equation, the aerodynamic noise produced by centrifugal fan is simulated. The sound pressure levels at the inlet and outlet monitoring points were obtained and verified by experimental tests. The aerodynamic noise of the cochlea tongue in the volute is the main sound source, and the change of its parameters has a certain effect on the noise of the fan. Because the EPS foam plate is used in the volute material, the cochlea shape may change or even fatigue damage can be caused by the gas shock under the large flow rate, and the volute vibration will also reduce the volute efficiency and the flow rate. In order to make the fan run more smoothly and reduce the vibration of the volute, it is necessary to optimize the whole structure of the volute of centrifugal fan. In this paper, a bidirectional fluid-solid coupling numerical calculation considering the interaction between internal flow field and volute vibration is carried out on the ANSYSWorkbench platform. The dynamic response of centrifugal fan volute under unsteady pressure is simulated. The front cover of the initial design model of the volute is strengthened with stiffeners, and the tongue part is thickened. The results show that the total deformation and equivalent stress of the optimized volute are obviously reduced, the stress concentration phenomenon of the volute in the cochlea tongue is solved, and the vibration of the front cover and outlet of the fan is effectively improved.
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TH432

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