Thermoeconomic Analysis of Different Technologic Alternatives for the Optimization of a Combined Cycle Power Plant.

ARENA, AP; CORREA, E

Berlin

Conferencia; 15th International Conference on Efficiency, Costs, Optimization, Simulation and Environmental Impact of Energy Systems; 2002

Technische Universität Berlin

Different technological alternatives for the perfomance improvement of a combined cycle power plant, located in Mendoza (Argentina) are evaluated from the energetic, economic and thermoeconomic viewpoint. The original cycle is made up with two 22 MW gas turbines which exhaust gases are used in a Heat Recovery Steam Generator for feeding a 27 MW steam turbine with two steam spilling. The first steam spilling feeds the deaereator, while the second one feeds a low pressure heater. The gases exiting the HRSG are very hot, reaching 200 °C in summer, indicating a low performance of the power plant. Two different technological alternatives where devised in order to improve the efficiency of the cycle, by recovering the thermal energy of the exhaust gases. The first alternative eliminates the second spilling, and the effect of the low pressure heater is replaced with the heat recovered from the exhaust gases in a new heat exchanger. The second alternative eliminates the first spilling, and uses the second spilling in a low pressure deaereator, using the heat recovered from the exhaust gases in a new heat exchanger for increasing the HRSG water inlet temperature.