News & Events-Work complete on gas turbine exhaust replacement for BP's Bruce platform

Engineering technology specialist Frazer-Nash Consultancy has announced the completion of it support to the BP Bruce gas turbine exhaust replacement project.

During the project, the company undertook detailed analysis of the failure mechanisms of the existing exhaust systems, provided concept designs for improved replacements, supported the EPC contractor PSN during the detailed design phase, undertook overall project management, and assessed the suitability of the installation and lifting systems.  The installation of the replacement systems is due to take place during the summer of 2012.

Offshore gas turbine exhaust systems are complex, being required to cope with extremes of temperature and flow and incorporate waste heat recovery, while being light enough for easy installation and robust enough to withstand the North Sea environment.  Failures are not uncommon, with flow induced vibration being a significant cause.

For many years this phenomenon was not understood in depth, and it is only with the development of modern Computational Fluid Dynamics (CFD) methods, especially the advanced and highly detailed Large Eddy Simulation (LES) technique, that it has been possible to replicate exactly what occurs within the exhausts.  Frazer-Nash use LES to simulate these systems, and the company was able to diagnose the causes of the problems encountered on the Bruce platform.

With this information, Frazer-Nash's design and structural analysis teams then developed and assessed new design concepts that extended fatigue life. Working with BP and PSN, these concepts were worked up into detailed designs.  Each exhaust had to be light enough to be installed by helicopter lift, so the lift points and frame designs were also carefully assessed to ensure that no distortion would occur.

With manufacture now largely complete and the installation procedure agreed, Frazer-Nash's role has come to an end. Simon Rees, Frazer-Nash Business Manager for Oil and Gas, said "We look on what we have achieved here with BP and PSN with enormous pride.  Every stage of this project has seen considerable technical challenges and required the deployment of sophisticated engineering techniques, yet at the end every bit of our contribution has been successfully delivered.  We hope to see the Bruce gas turbine exhausts provide many years of trouble-free operation".

At any one time, Frazer-Nash had between eight and ten members of its oil and gas team working on the project.