Marchwood CCGT Power Station saves circa £200,000 per year

Two Shift Operation Power Stations can benefit from Advanced Valve Solutions Expertise

Power stations that were originally designed for base load applications are now increasingly being asked to operate on a two shift, stop/ start regime. This is more commonly known in the industry as dual shifting.

The consequences of the change in plant operation cannot be ignored. If the plant is not operated correctly or, more importantly, modified properly to handle these changes the lifetime of the components within the plant will decrease enormously.

The changing operational requirements of the plant require that the steam coolers, de-superheater valves, drains, feed water control valves, main steam isolation valves and the turbine quick closing valves are reviewed. These critical pieces of equipment have to be specifically designed to take the new dual shifting process requirements into consideration.

Once this has been done the operational performance of the plant can be improved and wear and tear of systems and components can be controlled and significantly reduced.

The problem
• HRSG final desuperheaters (HP & IP) failing in service
• Life expectancy < 12 months
• Expensive to replace and overhaul
• High cost due to plant unavailability

The solution
• High quality, well engineered desuperheaters
• Protected by a steam cooled jacket
• Life expectancy > 12 YEARS!

The problem for James Brown, the Mechanical Engineer at Marchwood Power Station, was that the desuperheater valves installed would fail on average once a year leading to plant unavailability with all the obvious associated costs and some less obvious engineering issues.

James had worked with Advanced Valve Solutions on a previous project so had confidence in our engineers. He’d also had a positive experience of Hora valves elsewhere at Marchwood.

The installed desuperheaters were replaced with Hora cooled desuperheaters each protected by a unique steam cooled jacket.

The inspection cycle for the desuperheaters is now > 6 years and replacement is now > 12 years. Project payback was 1 year.

To understand more about the Marchwood Hora cooled desuperheater project and how the cost savings and payback were calculated call Rik Barry on 0161 242 1355.

For a full list of technical papers including two shift desuperheating visit the AVSwebsite http://www.avsnl.com/news/technical-papers

Advanced Valve Solutions (UK) Ltd
Tel: +44 (0) 161 242 1355
www.advancedvalvesolutions.co.uk

Published: 18th November 2014