Gas Turbine Package Life Extension – National Grid St Fergus

The Site is classed as COMAH (Control of Major Hazards) which means it is a highly dangerous facility and very important to the UK infrastructure. The Facility has 7 Gas Turbine Compressor packages (RR RB211 & RR Avon) that Pump Gas through the UK network. The Gas Turbine Units were supplied by Rolls-Royce and Cullum over a 10-year period, the last one being commissioned in 1979.

Problem

The Units at St Fergus are Coastal being only a few hundred meters from the Sea. This is a very harsh environment which see extremes of temperature, Fog, Ice and a heavy saline atmosphere. Cullum were tasked by National Grid to re-life 3 RR Avon units for a further 15 years of service allowing for them to operate until 2030.

Solution

Cullum Completed a detailed feed study that identified failures on Key parts of the equipment. These being the Ventilation system which controls cab temperature and bulk dilution and The Combustion exhaust systems that remover the hydrocarbons from the engine, also the unit structure itself needed reapir.

The Works that Cullum Undertook were:

• Fully redesigned the Ventilation system boosting cooling and bulk dilution.
• Replacing the Combustion Exhausts in their entirety to ensure all hydrocarbons are being removed from the Hazardous area.
• Carrying out re-roofing, re-cladding and structural repairs to the units allowing for a further 15 years of weather resistance.