Condition monitoring system prevents downtime at nuclear plant An online condition monitoring system for more than 90 electric motors, pumps and fans, warns of impending failures and helps to keep the availability of a nuclear power plant above 90 per cent. As a subsidiary of E.ON Energie, E.ON Kernkraft GmbH is a major contributor of electricity generation in Germany. The company operates six nuclear power stations and is involved in a further five plants. The company employs around 2,500 staff and generates a total annual output of 8,500MW, making the company one of the leading international generators of electricity. The Grafenrheinfeld nuclear power plant in Germany was commissioned in 1981. The pressurised water reactor is rated at 1,275MW and is cooled by two, 143m high, natural draught cooling towers. The plant generates electricity for base load applications. The working availability of the plant at this site has to be very high, at more than 90 per cent. This is not only because of safety reasons but also for efficient maintenance of plant and machinery. Failure of individual components or machines can cause costly secondary damage or shutdown of the complete plant and therefore result in more ‘lost’ production. E.ON Kernkraft in Germany is using the VibroCheck online condition monitoring system from FAG Industrial Services (F’IS). Since its initial implementation in 2004, the system has on several occasions identified damage to bearings, imbalance in fans and unstable machinery at an early stage, enabling the maintenance team to order the necessary spare parts and resources and to plan the replacement of the damaged part within the regular maintenance schedule or shift. The VibroCheck is designed for condition monitoring of critical rotating machinery and components, such as gearboxes, bearings fans and pumps. Using selective frequency monitoring, it automatically detects imbalance and misalignment in rotating plant and machinery, as well as damage to individual bearings and gears. Selective frequency monitoring enables the detection of even minor damage or defects at an early stage, since these will cause an increase in the amplitude of the characteristic frequencies. The system also uses demodulated signal analysis as this is ideally suited to shock pulses. The system enables the monitoring of up to 2,048 measuring points and can be easily integrated into a plant’s existing systems. Remote monitoring is possible and alerts can be sent via email or SMS text message to the appropriate individual. At E.ON Kernkraft, more than 200 separate measuring points are being monitored, which provides maintenance with information on the condition of rolling bearings, gear sets, shafts and imbalanced rotors in fans and pumps. Although 12 staff at E.ON are trained to use the VibroCheck system, the company also has a teleservice contract, which includes the online remote monitoring of the plant and technical support by F’IS vibration monitoring specialists, who help to analyse and evaluate recorded data. For example, the condition monitoring system at E.ON Kernkraft recently detected bearing damage in a pump at an early stage. This damage was then confirmed by visual inspection and the bearing replaced in plenty of time by the maintenance team. If left undetected, the bearing damage would have led to failure of the pump, resulting in a complete shutdown of the plant. Speed Link InfoService Request more information by e-mail Reader Service No. Reader Number Email Address 01231    Tell a friend about this article:
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