ANALYSIS OF FLOW FIELD CHARACTERISTICS IN THE HYDROTURBINE INTAKE PENSTOCK OF THREE GORGES POWER STATION BY MODEL EXPERIMENT

摘要

The accuracy of ultrasonic flowmeter is closely related to flow field on the job site. Because the hydro turbine intake penstock of Three Gorges power station is very large and specially shaped, the flow field at position of ultrasonic flowmeter installed and its effect have a lot of uncertainty. A model pipe system and a model meter with 500mm diameter were designed and machined according to penstock of Three Gorge power station. The characteristics of velocity distribution were sketched from flow rate tested by each path at different altitude of the flowmeter, while the dispersion of each path shows the degree of disturbance. Comparing several group tests result on different experimental condition, it is quite obvious that velocity distribution is asymmetry. It's also found that ultrasonic flowmeter with double measurement planes can reduce the effect of transverse flow, but error of flowmeter is about positive 0.3% due to the special flow field of the penstock model.