Effective monitoring of turbines is a critical requirement across a range of power generation applications, helping to ensure smooth running and trouble-free operation of rotating machinery before faults and the consequences of downtime occur. Sensonics has been developing monitoring systems based on more than 40 years of experience. This expertise includes specialised instrumentation solutions for power turbine, pump conditioning monitoring, as well as seismic protection across a wide range of critical monitoring applications. The design of its Sentry G3 system has been developed and enhanced in conjunction with customer needs, resulting in a hardware configuration with online test facilities.
This project began when Rolls-Royce Marine Electrical Services contacted Sensonics because its vibration monitoring system for their Spey Gas Turbine was no longer supported by the original supplier.
As a result, the Sentry G3 machine protection system was supplied, installed and tested at The Royal Navy’s HMS Sultan Spey test house in 2015. The monitoring systems were subsequently approved. Each of the gas turbines has kept the existing three velocity vibration transducers, two on the GT (mounted front and rear) and one on the power turbine, which equates to six channels of machine protection per frigate. The resulting contract awarded involved 12 x 8 channel Sentry G3 systems for vibration monitoring of the Rolls-Royce Marine Spey Gas Turbines (2 per Frigate on the Royal Navy’s Type 23 Frigates.
Fast forward to 2024, and the Sentry G3 system has now been installed on the Royal Navy’s HMS Richmond and HMS Somerset, with plans to install the system on HMS Portland, HMS St Albans, HMS Sutherland in the near future, along with HMS Iron Duke, depending on the ship's programme.
Since its introduction, the Sentry G3 system and its features have been developed and enhanced in conjunction with customers’ needs in both the conventional and nuclear power industries. For example, the provision of gas turbine specific measurements such as first order vibration tracking and dynamic pressure, are both requirements recommended by gas turbine manufacturers. In addition, the speed algorithm has also been optimised to accept a wider range of speed probes and now offers a sensitivity performance over a wide speed range, ensuring the turbine interlocks can be integrated effectively into the G3 system over a range of operational conditions.
The new measurement algorithms can be downloaded into the common hardware module and complement the other established measurements, such as broadband vibration, temperature and speed. The flexibility of the G3 system sensor interface also permits a range of sensor types to be utilised providing both the necessary drive power supplies and fault detection.
According to Sensonics, the system offers channel density with up to 24 measurement channels in a 3U x 19” racking format, while the diverse system architecture separates functions across the independent modules, providing a channel reliability suitable for safety instrumented systems.
The additional features incorporated into the latest Sentry G3 system provide a set of tools to assist plant engineers to optimise the control and overspeed management of turbines and other rotating plants.