Staying power - how vibration analysis improves reliability of rotating machinery
In 2014, The University of Manchester’s Dynamics Laboratory began a collaborative project with French energy company EDF to examine ways to improve the lifespan and reliability of certain rotating machinery components in UK power stations.
Specifically, EDF was eager to tackle regular failures at West Burton and Cottam power stations in the Trent valley. A fan motor (West Burton A), cooling tower fan gearboxes (West Burton B) and lift pumps (Cottam) were the priority targets for our researchers, drawing on extensive work into the measurement and modelling of vibration issues, led by Professor Jyoti Sinha at the Department of MACE.
Professor Sinha implemented a system of in-house analysis for EDF, using PC-based data acquisition (DAQ) and signal processing to meet the day-to-day plant requirements in vibration-based condition monitoring (VCM), with the following outcomes:
West Burton A
EDF estimated annual costs of failure of the primary air fan motor at £80,000. The root cause of the issue was identified as a rotor imbalance and rectified by adjusting the coupling between the fan and rotor shaft. Since the repair in 2014, there has been no subsequent failure, with savings >£80,000 per annum.
We have really benefited from the expertise and hands-on approach used by Jyoti and his team to solve our problems. The team promoted plant availability and profits by turning critical plant around during down-time due to component failures.
Wolfgang Hahn / EDF Asset Life Cycle Manager
West Burton B
In-situ vibration measurements identified the cause of failure in cooling tower fan gearboxes to be resonant vibrations between the gearboxes’ supporting structure and gear mesh frequencies. The old gear boxes in 30 fans were replaced with different gearboxes having different gear ratios and weight to avoid the resonance. With no failure since 2015, estimated savings over four years >£500,000 per annum.
Cottam
Here, lift pumps that discharged large volumes of water (22,500 litres per minute) had reliability issues. The cause was diagnosed as the water hammer (ie high impact pressure of water returning in the system) when pumps shut down and the non-return valve operates. New, springloaded non-return valves were fitted following recommendation from the in-situ vibration measurements. Again, EDF reported no failure from 2015 to Cottam’s decommissioning in September 2019, with estimated maintenance saving of >£150,000 per annum (excluding cost of lost generation).
If you would like to find out more about the work Professor Sinha and his team are doing, or are interested in business or research collaborations, please email: