两级轴流风机动叶非同步调整时的性能研究

发布时间：2018-01-03 20:21

本文关键词：两级轴流风机动叶非同步调整时的性能研究　出处：《华北电力大学》2015年硕士论文　论文类型：学位论文

【摘要】：两级动叶可调轴流风机因风量大、变工况性能优越的特点而广泛应用于当前大型火力发电机组的锅炉风烟系统中的一次风机。在实际运行中,轴流风机叶片非同步调整的现象时有发生,这是影响风机运行性能和稳定性的重大隐患之一。本文以某600MW机组配套的两级动叶可调轴流一次风机为研究对象,对其进行了全三维定常数值模拟,首先模拟了两级叶轮上周向位置相同的叶片发生同角度异常偏离时风机的气动性能、叶轮做功能力及噪声特性,并与单级叶轮叶片异常时进行了对比;然后以两级叶轮上异常叶片的四种特征特征周向位置关系为例,分析了异常叶片位于不同周向位置时,风机性能和内流特征的变化特征。研究表明,与单动叶异常情形相比,两级动叶异常时叶轮做功能力、导叶效率、风机噪声和气动性能更差,失速区明显扩大,尤其正偏离时更为显著;随Δβ增加,负偏离下叶轮做功能力强于正偏离情形,风机噪声总体呈升高趋势,正偏离对异常叶轮噪声分布的影响大于负偏离情形;正偏离时,导叶区流动损失大于同角度负偏离情形。异常叶片位于不同周向位置时,对风机性能和内流特征的影响程度有较大区别,按文中描述方式,第一级叶轮上叶片(FAB)与3#叶片异常正偏离时,风机性能及内流特征的变化最为剧烈;FAB与4#叶片异常对风机的影响稍低于前者;FAB分别与1#、2#叶片异常对风机的影响程度相近且小于前两种情形,FAB与2#叶片异常时,风机性能的变化最小。
[Abstract]:Two stage moving blade adjustable axial flow fan with variable air volume, the feature of superior performance and a fan of boiler flue gas system is widely used in the current large-scale thermal power generating units in. In actual operation, the axial flow fan blade non synchronous adjustment phenomenon, this is one of the major risks effect of fan performance and stability. In this paper a 600MW unit supporting the two stage moving blade adjustable axial flow fan as a research object, has carried on the three-dimensional unsteady numerical simulation, simulation of the first stage impeller blade two last week to the same position with angle deviation of gas fan the aerodynamic performance of the impeller and the noise characteristics, work capacity, and compared with the single stage impeller is abnormal; then in four weeks on characteristics of two stage impeller blades to abnormal position relationship as an example, analyzes the abnormal leaf at different circumferential positions, The change characteristics of the flow characteristics and fan performance. Research shows that compared with the single blade abnormal, two stage blade abnormal impeller vane capacity, efficiency, fan noise and aerodynamic performance worse, stall region expanded significantly, especially the positive deviation is more significant; with the increase of negative delta beta. From work capacity of impeller under strong Yu Zheng deviation, the fan noise generally showed an increasing trend, the positive deviation is greater than the negative deviation of the abnormal distribution of the noise is deviating from the impeller; when the guide flow loss of leaf area larger than the same angle. The negative deviation abnormal blades at different circumferential position, there is a large difference between the influence of flow characteristics the performance of the fan and the press described in this paper, the first stage impeller blade (FAB) and 3# leaf abnormal positive deviation, fan flow characteristics and performance changes in the most violent; FAB and 4# abnormal effects on the wind turbine blade is slightly lower than the former; FAB The influence degree of 1# and 2# blade anomaly to the fan is similar and less than the first two cases. When the FAB and 2# blades are abnormal, the change of the fan performance is the smallest.

【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TH432.1

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