万家寨引黄南干7号洞出口大流量高精度测流设施及其使用总结

Large discharge and high precision flow measurement facilities on Wanjiazhai Yellow River Diversion Project south branch No. 7 tunnel outlet and the summary of application thereof

万家寨引黄工程向汾河输水量最大达19.35m^3/s,在输水隧洞出口安装了梯形薄壁堰、Accusonic7500四声道超声波流量计、Risonic2000双面八声道超声波流量计。鉴于梯形薄壁堰超常规测流,对其流量系数进行了室内模型试验,并用断面流速法进行了校核。选取不同流量下长时段测流数据进行比较,测流相对精度均高于1.5%。本文结合现场建筑物布置情况、输水运行实践,对三套流量计使用情况进行了分析,认为三套流量计测流均精度高,稳定性好,并对各自优缺点进行了分析。

The maximum water diversion capacity of Wanjiazhai Yellow River Diversion Project to Fenhe River is up to 19. 35m^3/ s. The exit of water outlet tunnel is provided with a trapezoidal thin-wall weir,an Accusonic7500 four tracks ultrasonic flowmeter and a Risonic2000 double-sided eight tracks ultrasonic flowmeter. Indoor model test is implemented on the flow coefficient thereof,and it is calibrated through cross section flow rate method due to the extraordinary flow measurement of trapezoidal thin-wall weir. Long duration flow measurement data under different flow discharge are selected for comparison. The relative precision of flow measurement is higher than 1. 5%. In the paper,site building layout condition and water conveyance operation practice are combined for analyzing the application condition of three sets of flowmeters. It is believed that the flow measurement precision of three sets of flowmeters are high with high stability.Respective advantages and disadvantages are analyzed.