直接空冷单元风机入口脉动气流的谱特征研究  

Study on Spectral Characteristics of Pulsatile Airflow in Fan Inlet of a Direct Air-cooling Condenser

作　　者：李宴君[1] 唐大伟[1] 张璟[1] 温娟[1] 

机构地区：[1]中国科学院工程热物理研究所,北京市海淀区100190

出　　处：《中国电机工程学报》2012年第29期73-78,I0011,共7页Proceedings of the CSEE

基　　金：国家重点基础研究发展计划项目(973计划)(2009CB219804)~~

摘　　要：作为直接空冷系统冷却介质的空气气流在环境自然风和风机机械风的共同作用下参与换热。为深入研究风机间的干涉情况、分析空冷单元周围气流的驱动机理,采用IFA300热膜风速仪对空冷凝汽器实验台风机入口气流的速度时间序列信号进行了采集,运用功率谱分析的方法对数据进行了分析。实验结果显示气流的湍流强度随平均速度的减小而增加;脉动速度在谱分析图中的能量分布状况表明距离风机越远,低频区能量所占比例越大;在距离风机较近的地方功率谱指数较小,随距离的增加值出现逐步升高的趋势;气流中的机械风成分逐渐被自然风取代。On the multi-fan platform of air-cooling condenser system, airflow participates the heat transfer under the effects of natural wind and mechanical/fan wind. In order to study the interaction between fans and the driving source of airflow, pulsatile velocity of the airflow in the fan inlet of an air-cooling condenser was measured by IFA300 hot-film anemometry and analyzed using power spectrum analysis. The results indicate that the turbulent intensity increases with airflow velocity. The spectral energy of airflow gradually focuses on low frequencies when the distance from the fan increases. Correspondingly, the power spectrum index （β） closed to the fan is small and the β value increases with the increasing distance from the fan. The airflow character is transferred from mechanical wind to natural wind.

关 键 词：空冷凝汽器 气流速度 功率谱 湍流 热膜风速仪 

分 类 号：TK264[动力工程及工程热物理—动力机械及工程]