Gas Turbine Exhaust Energy Margin in a Combined Cycle Power Plant

Margining gas turbine exhaust energy exposes the EPC (Engineering, Procurement & Construction) contractor to risk when developing overall plant performance guarantees. The objective of this paper is to explain the nature of this risk, recognize its significance and propose ways of mitigation. Sharing risk between the Developer and the contractor should be apportioned to maximize value for the project. Attention is focused on 2 on 1 combined cycle power plants, but the results are relevant for all types of gas turbine based power and cogeneration facilities. Risk mitigation alternatives discussed include both assessment of margins to the bottomline performance and the application of performance corrections at the time of field testing. Allowing for corrections leads to enhanced overall plant performance guarantees.