BREATHING NEW LIFE INTO AN OLD PLANT

摘要

After 15 years running on proprietary hardwired distributed control system, TNB’s SultanrnSalahuddin Abdul Aziz Power Station Unit No. 2 (300MW-Gas/Oil-fired) underwentrnmajor control system rehabilitation recently. This timely decision was made chiefly duernto the imminent obsolency and limitations of the original control system. Following anrnoutage of 70 days for Distributed Control System (DCS) revamp, turbine controls retrofit,rnplant overhaul and modification works, the unit was successfully re-commissioned. Withrnfurther on-line testing and fine-tuning, the unit is now running at full capacity with itsrnnew open architecture DCS and turbine control system.rnIn this paper the authors present their experience in managing the various stages of thernproject and the technical aspects involved. As the number of plants in the regionrnconsidering control system rehabilitations are expected to rise, the authors hope theirrnexperience here will be able to help in the planning and implementation of such futurernprojects.rnThis paper documented the various phases of the entire project duration starting from thernjustification phase through to approval to planning and specification preparation. This isrnfollowed by the vendor selection, project awarding and design stages to factoryrnacceptance tests. Amongst the most challenging part of the project was the siterninstallation, commissioning, tuning and testing phase, which involved dealing with ‘live’rnsituations. This called for detailed planning and precautions to safeguard personnel andrnequipment safety and minimize downtime. The last phase covered warranty and defectsrnclearance which called for commitment from all parties to ensure the overall project goalsrnare met.rnInteresting aspects illustrated included emphasis on planning and risk aversion, projectrnand design philosophy, technical design options, discrepancies between actual conditionsrnand drawings, various control scheme and plant equipment improvements, limitations