Vibration testing of hydraulic unit No. 6 completed at Sayano-Shushenskaya HPP

Vibration testing of hydraulic unit No. 6 completed at Sayano-Shushenskaya HPP, which was aimed at vibration monitoring of the unit’s mounting groups, specifying allowable working areas, and assessing the 3500 Bently-Nevada stationary vibration monitoring system. The system, which was installed at the beginning of March, enables continuous control of hydraulic unit’s major mounting and rotating groups.

The tests were carried out by energy specialists of Leningradsky Metallichesky Zavod, Power Machines’ branch, aided by specialists of RusHydro’s Sayano-Shushenskaya HPP named after P.S. Neporozhniy. According to test results, mounting members’ vibration and shaft beat in allowable working areas do not exceed permissible levels. Ultimate test results will be announced upon further processing and analysis of the vibration monitoring system to be performed at Power Machines’ Leningradsky Metallichesky Zavod.

Preparatory arrangements that had been made before the tests included shutdown of the sixth hydraulic unit, erection of brackets, fixtures, vibration and shaft beat sensors, together with pressure / pressure oscillation sensors. Test point equipment was put in place, accompanied by installation of necessary instrumentation and setup of measuring circuits. After that, the hydraulic unit No. 6 was hooked up and measurement instrumentation was then adjusted.

Hydraulic unit’s vibration monitoring involved the 3500 Bently-Nevada stationary vibration monitoring system, as well as temporary measuring systems of Power Machines’ Leningradsky Metallichesky Zavod and those of Polzunov Scientific and Production Association for Research and Design of Power Equipment (NPO CKTI). Following each operating mode measurement, estimation was made of the unit’s vibration condition. Measurement time for each mode was approximately five minutes, and certain modes were repeated when required.

All tests were performed at upstream and downstream elevations observed as of the test commencement date. During the tests, nearby the electrohydraulic controller unit duly instructed operating personnel were present, who could take actions on disconnection or shutdown of the hydraulic unit if necessary. For the test period, guard circuits for the protection from excessive vibration and shaft beat levels were disconnected.

All of Sayano-Shushenskaya HPP’s hydraulic units will be equipped with the stationary vibration monitoring system, which will enable continuous control of hydraulic unit’s major mounting and rotating groups. If monitored parameters exceed allowable values, the system automatically generates signals for emergency shutdown of the hydraulic unit, and for release of the closing valve, when required.

Full-featured systems for vibration monitoring are being installed in pursuance of recommendations of the commission set up within the Federal Technological, Environmental and Atomic Supervisory Service (Rostekhnadzor) to investigate factors that caused the accident at the Sayano-Shushenskaya hydropower plant.

Installation project for the Bently-Nevada stationary vibration monitoring system was developed by specialists of Lenhydroproject and RusHydro. Experts from a specialised institute – Scientific and Production Association for Research and Design of Power Equipment (NPO CKTI) – are also engaged in analysing values of hydraulic units’ vibration condition.