Train 3 Efficiency Upgrade
Train 3 HRSG was originally designed to maximise process steam production and consequently of a single pressure design, supplying steam to a two cylinder non reheat extraction Steam Turbine. Therefore the train had a highly efficient Gas Turbine 9FB being combined with a relatively inefficient single pressure HRSG. This configuration resulted in a major loss of HRSG efficiency with high exhaust flue gas temperature being lost via the main stack to atmosphere.
In order to improve the overall electrical efficiency of the train VPII undertook performance modelling showing the impacts of installing a new IP circuit into the HRSG. The calculated impact demonstrated a improvement to the electrical efficiency of ~1.7% of total power produced over the annual operating envelope of the power train. Now delivered the HRSG IP upgrade project will provide a positive improvement and secure suitable repayment of capital over a short period of time.