OTC Leak Search & Repair
The GT 26 low pressure and high pressure Once Through Coolers (OTC) reduce the temperature of the Gas Turbine’s cooling air systems. This is through a heat exchange between the GT cooling air and water (steam) from the Water Steam Cycle. Over operational time the OTC’s can develop leaks between the air and water sides.
This leak of water into the cooling air system detrimentally increases demin water consumption and has the potential to impact the cooling air ratios. It can also lead to increased levels of corrosion in the system.
There is a simple repair on an OTC with a leak. The affected OTC needs to be opened, the leak located, then plugged and the OTC closed again. This requires a team including a lead engineer, pipe fitters, coded welders and specialist support of NDT and Heat Treatment services.
Salko was engaged to carry out such a search and repair recently for a GT26 client on behalf of the OEM completing a larger inspection of the power plant.