Challenges in Combined Cycles Integration of 'H' and 'J' class gas turbines – an EPC Contractor perspective

摘要

In recent years, the equipment manufacturers have made significant strides to develop better and more life cycle cost effective products: Gas Turbines (GT), Steam Turbines (ST), Heat Re-covery Steam Generators (HRSG), water treatment, fuel treatment equipment etc. Consequently, the Combined Cycle Power Plants (CCPP) have become, due to many technological break-throughs, the most efficient form of electrical power generation from fossil fuel, exceeding net efficiencies of 60%. We are also witnessing a substantial penetration of Renewable in the power generation mix. The Renewable intermittent nature of generation associated with new grid re-quirements for spinning reserves and/or frequency control must be considered when new CCPP are conceptually designed. The paper will examine challenges in integration and construction of several CCPP plants using advanced Siemens H and MHI J class gas turbines. Substantial improvements in the efficiency are usually associated with increased gas turbine electrical output as well as exhaust flow and temper-atures. These new configurations need to be complemented with the appropriate upsizing of the balance of plant equipment. The sheer size of the equipment requires special design considera-tions. The challenges of major equipment integration (gas turbines, heat recovery steam generators steam turbines, and heat sinks) for each of the configurations will be examined from Engineering, Procurement, Construction (EPC) Contractor’s perspective, A special emphasis will be given to the strategy of providing the CCPP with fast start-up, capa-bility, rapid load changes, without negatively impacting part-load efficiencies and emissions. The plant configuration should take in consideration also reliability, and maintenance requirements be Finally, the paper describes the lessons learned, in design and construction of these large power plants that can be successfully employed on future projects through judicious equipment selection at the development phase, design optimization and proper project management at the execution phase.