Richard Hale discusses the importance of planned maintenance in avoiding costly downtime at power generation plants.
For plant managers and engineers in the power industry, the pressures are greater than ever to provide reliable, cost effective results that adhere to the industry’s strict health and safety and environmental standards. Planned and proactive maintenance of equipment should play a key role in the drive to avoid downtime, maintain high standards and keep repair costs down.
Implications of forced outage
Putting a figure on the cost of unplanned downtime can be difficult, but the most significant factor in this downtime is often the loss of revenue that the outage causes – according to InTech, downtime costs a plant on average at least 5 per cent of its productive capacity, and many lose up to 20 per cent. Couple to this the cost of repair, and the financial implications are considerable.
The continued function of equipment in power generation plants is all the more important because of the stringent health and safety criteria and environmental considerations that have to be met. With the vast number of conditions in place from the UK Government, and internal safety programmes and assessments in place, the risk of equipment failure must be reduced as far as possible.
The failure of any number of pieces of equipment, from cooling equipment to pumps and valves, could result in a failure to meet these criteria, leading to legal or financial implications. So how can plant managers ensure that this does not happen?
There are a number of ways that plant managers can reduce the risk of failure to their equipment, including predictive analysis technology and costly equipment replacements, one of the most effective is planned maintenance. By taking a proactive approach to maintenance, and where necessary strategic redesign, it is possible to significantly reduce the risk of equipment failure.
By planning maintenance programmes, it is not only possible to maintain the condition of equipment, but plant managers can also foresee future problems and understand how machinery is behaving. This in turn means that it is not only possible to reduce the risk of failure, but to improve the efficiency and productivity of equipment.
The maintenance of motors and pumps, in particular, can be carried out quickly and efficiently through a planned programme, without major disruption to the ongoing function of the plant.
Deritend has carried out such work in the power industry at facilities including Coryton refinery in Essex and Baglan Bay power station in South Wales. By taking pro-active action to maintain equipment, these power plants have been able to keep equipment running smoothly and efficiently, avoiding costly repairs and meeting environmental and safety requirements.
Working with GE Power Systems, the owners of the site, Deritend undertook work to overhaul cooling tower motors at the Swansea site. The Deritend engineers created a bespoke plan for the power station that involved working concurrently on the cooling towers’ gearboxes, so that the work can be carried out with minimum disruption to the plant.
GE Power Systems required 10 cooling tower motors to be overhauled in order to provide vital maintenance. This was a planned project in order to avoid the motors failing in the future which would prevent the cooling towers from functioning - an outcome that could have disastrous consequences. The work involved removing the motors from the site to Deritend’s specialist facilities and reinstalling them once the overhaul had been completed.
Previous to contacting Deritend, the motors and gearboxes were the responsibility of different departments. This in turn meant using two separate contractors to undertake the work. By taking on both elements, Deritend worked simultaneously on both motors and gearboxes, which offered significant time and cost savings as well as minimising disruption to the plant’s ongoing function.
The amount of health and safety documentation required was reduced, simplifying the administrative process. This was the first time that such a service had been offered for this type of work and the client was able to reap the benefits with significant financial and administrative savings, ensuring that the vital energy generation at Baglan Bay can continue unhindered. [Page Break]
At Coryton, a strategic maintenance programme has also been put in place. Deritend worked at the refinery between 2005 and 2012, providing a range of onsite maintenance and repair services for electrical and mechanical equipment. Once again, a strategic maintenance programme helped to ensure safety while minimising downtime and need for repair.
The example of Coryton highlights how, when equipment failure does occur, having that strategic programme in place can help to fix the problem and restore function as quickly and efficiently as possible.
When a 5MW generator failed it had to be repaired quickly, efficiently and safely for the plant to remain online at full function. Without power from the generator, the plant’s owners were forced to purchase expensive energy directly from the National Grid in order to power the facility.
Because of the maintenance programme, Deritend’s engineers identified the problem and quickly determined the best solution. The generator was removed from the plant and fully repaired off site, working 24/7 in three operations at Luton, Wolverhampton and the Pre-Formed Windings facilities in Sheffield. This was done in parallel to reduce lead time, so the generator could be returned and installed in full working order as soon as possible.
The benefits of planned maintenance in both of these examples are clear.By taking a proactive approach, downtime was minimised and at of Coryton, when equipment did fail, it was possible to isolate and resolve the issue quickly.[Page Break]
An holistic approach
Through a strategic maintenance approach it is possible not just to maintain equipment and plant function, but also to improve and enhance it. As part of an asset management programme, analysing data and applying intelligence to improve performance, plant managers can bring increased performance and also provide efficiencies in terms of energy consumption.
By monitoring assets 24/7, plant managers and engineers can learn exactly how equipment is working, planning ahead for necessary maintenance and spotting where failure might be imminent.
As shown by the examples of Coryton and Baglan Bay, strategic maintenance programmes can have significant benefits for power plants in terms of cost efficiency and smooth running but can also help safeguard against health and safety and environmental failures. At a time when the industry is under pressure to deliver against so many different requirements, all plant managers should be considering this simple process to protect and preserve their assets.
Richard Hale is Managing Director of Deritend Industries, Where. www.deritend.co.uk