水电厂超声波测流试验及CFD验算

Ultrasonic flow measurement and CFD verification in a hydropower plant

对国网江西省电力公司柘林水电厂改造后的机组的效率进行了试验,试验过程中,选用了超声波法和流速仪法来测量其流量。试验结果表明,两种流量测量方式的实测结果存在着大约+2.37%的相对误差。针对存在的误差,对其成因开展了分析研究。分析结果表明,由于超声波法和流速仪法在测流时是同步进行的,这样就使得流速仪的支架影响到了超声波测流声道的流场分布,从而导致超声波法的测流结果出现了偏大的误差;为此,进一步对测流管道、流速仪支架及超声波的测流声道进行了CFD模拟和计算,得到流速仪支架对超声波测流结果的影响大约为+2.2%。经过对试验结果与CFD模拟结果进行对比分析,验证了流速仪支架是导致上述试验误差的主要原因。

An efficiency test for revamped generator unit in Zhelin Hydropower Plant of Jiangxi Electric Power Company was carried out by using ultrasonic method and current meter method to measure the flow rate simultaneously.The test results showed that there was a relative error of+2.37%between the two methods.The current meter frame was assumed as the cause of the error because it influences the flow field distribution of ultrasonic channel.Furthermore,the CFD simulation on the flow measurement pipe,the current meter frame and the ultrasonic flow measurement channel was carried out,showing that the influence of the current meter frame on the ultrasonic flow measurement results was about+2.2%.Comparing the test and the CFD simulation results,the flow meter frame was verified to be the main cause of the error.