Advanced active magnetic bearings

Paul Boughton

Increase the mean time between repair from three months to more than five years, reducing maintenance costs and total cost of ownership. Mikhail Ponomarev reports

Located in the Leningradskaya region of Russia, Gazprom’s Compressor Station Elizavetinskaya-1 is a key point of the Gryazovets-Vyborg Pipeline. It provides gas to European consumers via the Nord Stream Pipeline and to the northwestern region of Russia.

Due to bitter experience with other compressor stations in frigid locations, Gazprom sought to improve their compressors’ operations by seeking a new supplier of active magnetic bearings. Their goal was to improve availability and reliability for uninterrupted gas delivery to consumers.

In addition, they wanted to eliminate process oil in the bearings to reduce required maintenance and potential fire hazards throughout the 900 kilometres of pipeline and 55 billion cubic meters of gas.

Gazprom began operation of compressors with active magnetic bearing (AMB) systems in the early 2000s. Since then, they had worked with one local supplier and had little success.

With low reliability and the low quality of the local supplier’s equipment, customers weren’t receiving the gas in appropriate volumes, and with cold temperatures, repairs often took longer.

In late 2008, Gazprom partnered with Mitsubishi Heavy Industries (MHI) and Waukesha Magnetic Bearings (WMB) to develop a more reliable system. MHI provided a 16MW gas compressor and WMB supplied the AMB system for the compressor.

In total, four gas compressor units with WMB systems were installed at the Elizavetinskaya-1 site and were successfully commissioned in early 2012. All components were certified according to Russian standards (GOST).

Gazprom results showed immediate improvement over the other system in operation. After 10,000 hours of operation, the availability exceeded 95%. This increased reliability means continuous gas delivery and energy security to consumers in a sustained manner.

The AMB system from WMB increased the mean time between repair from three months to more than five years, reducing maintenance costs and total cost of ownership. It also provided simpler integration with the compressor station due to the digital output/input from the digital control cabinet, versus previous experience with analogue cabinets.

Additional benefits included time savings with an easier commissioning and tuning process, remote monitoring and adjustment capabilities, higher processing performance that allows for more complex algorithms that provide higher dynamic efficiency, improved usability and ergonomics, and noise immunity.

The success of the first installation of four sets led Gazprom to approve the Waukesha Magnetic Bearings AMB system application for future projects.

Mikhail Ponomarev is with Waukesha Magnetic Bearings.

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