بررسی تاثیرات هوادهی در جریان خروجی توربین بر کنترل پدیده طناب‌گردابی در نیروگاه سد مسجدسلیمان با کمک داده‌های ارتعاشی و صوتی

In this research, the effects of air-admission under the runner of the Francis turbine of the third unit of the Masjed-Soleyman dam hydropower plant has been investigated in order to control the shaking and destructive phenomenon of the vortex rope with the help of the data obtained from the vibration and sound sensors. In the implementation of the air-admission system, a free aeration system with two air inlet paths to a vertical pipe with an open top and bottom been used. The vertical pipe has holes with a specific diameter and is placed exactly under the turbine runner. Bentley-Nevada model vibration sensors with a sensitivity of 2 mV were used to measure the amplitude of the vibrations of the turbine under the influence of the aeration system, installed in the location of its journal bearings. Also, in order to measure the effect of the air-admission system on the sound intensity extracted at the power plant turbine site, the sound intensity sensors of the Kimo DS300 with the ability to measure the sound intensity up to 140 dB were used, which were installed at the site of the visit door of the Francis turbine. These results are in Powers from 110 to 180 MW were measured in steps as 110, 120 ,… MW. The results of using the air-admission system in the unfavorable phenomenon of the vortex rope of the Francis Turbine output flow were all signs of improvement and reduction of this unfavorable phenomenon. However, comparing the results obtained by measuring the amplitude of vibrations as well as the sound intensity observed from the rope-vortex phenomenon, it could clearly concluded that the method of measuring the amplitude of turbine vibrations has a higher sensitivity to changes and as a preferred method for detecting the vortex rope process is recommended.