Abstract Flow meters in thermal power plants are operated at high temperatures and pressures and often encounter disturbed flow profiles. This leads to an increased measurement uncertainty, limiting the safe operating range of flow rates and thus, the plant's power output. To respond to this shortcoming, the laser optical flow rate standard (LFS) was developed. The LFS is designed to allow the on-site calibration of industrial flow meters in power plants at high temperatures and pressures. It makes use of the laser Doppler anemometry (LDA), as a fundamental and non-invasive method, to measure the velocity field simultaneously with two LDA systems. The volumetric flow rate is then determined by means of integration. Here, we present flow rate measurements for a fully developed pipe flow and for six pipe diameters downstream of a disturbance generator. The mean deviation in flow rate between the two LDA systems was 0.05%, with a mean deviation from the gravimetric reference flow rate of 0.12%. The highest deviations from the reference were 0.21% and 0.31%, for the first and second system respectively.

中文翻译：

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LDA体积流量标准在严重扰动流动条件下的性能

摘要 火力发电厂中的流量计在高温高压下运行，经常会遇到扰动的流动剖面。这导致测量不确定性增加，限制了流量的安全操作范围，从而限制了工厂的功率输出。针对这一缺点，开发了激光光流率标准（LFS）。LFS 旨在允许在高温和高压下对发电厂中的工业流量计进行现场校准。它利用激光多普勒风速仪 (LDA) 作为一种基本的非侵入性方法，通过两个 LDA 系统同时测量速度场。然后通过积分确定体积流量。这里，我们为完全发展的管道流和扰动发生器下游的六个管道直径提供了流速测量值。两个 LDA 系统之间的流速平均偏差为 0.05%，与重量参考流速的平均偏差为 0.12%。对于第一和第二系统，与参考的最高偏差分别为 0.21% 和 0.31%。