CFD技术在汽轮机定子线圈冷却水流量测量中的应用

The Application of CFD (Computational Fluid Dynamics) Technology for the Measurement of Cooling Water Flow in a Turbogenerator Stator Coil

利用超声波流量计检测大型汽轮发电机定子线圈冷却水流量大小 ,可直接判断冷却水的堵、漏 ,从根本上解决定子绕组冷却水堵塞问题 ,但超声波流量计用于弯管段测量时存在误差。本文利用CFD技术计算了某火电厂定子线圈内冷却水的流速分布 ,分析了管内流动对超声波测流的影响 ,获得了不同测点处流量误差的变化趋势。采用CFD技术可确定超声波流量计的最佳安装位置 ,为获得准确的流量提供理论依据。

By using an ultrasonic flowmeter to detect and measure the flow rate of cooling water in a large-sized turbogenerator stator coil it is possible to directly ascertain whether there exists a phenomenon of cooling water jamming and leak, thus thoroughly solving the problem of cooling water blocking. However, when the ultrasonic flowmeter is used for conducting measurements in a curved tube section, errors may occur. By using CFD (computational fluid dynamics) technology the authors have calculated the cooling-water flow velocity distribution in the generator stator coil at a thermal power plant and analyzed the influence of in-tube flow on ultrasonic flow gauging. As a result, the variation tendency of measurement errors at various measuring locations was obtained. The use of CFD technology makes it possible to determine the optimum installation location for an ultrasonic flowmeter, thus providing a theoretical basis for obtaining an accurate flow rate.