Abstract
The operational strategy for cost saving is investigated for an existing gas turbine cogeneration plant with steam injection and inlet air cooling whose operation is difficult to determine because of its high flexibility. An optimization approach based on the mixed-integer linear programming is adopted to acquire the knowledge for the rational operational strategy. The on/off status of operation and energy flow rates of each piece of equipment as well as the adoption and amounts of steam injection and inlet air cooling of a gas turbine cogeneration unit are determined so as to minimize the hourly operational cost subject to performance characteristics of equipment and energy balance relationships. This optimization problem is solved for various combinations of power and steam demands under various ambient air conditions. The optimal operational strategy of the cogeneration unit is illustrated by operational maps, which clarify the conditions for the effective use of steam injection and inlet air cooling.
