1 Copyright © 2010 by ASME Proceedings of ASME Turbo Expo 2010: Power for Land, Sea and Air GT2010 June 14-18, 2010, Glasgow, UK GT2010-23058 REPOWERING: AN OPTION FOR REFURBISHMENT OF OLD THERMAL POWER PLANTS IN LATIN-AMERICAN COUNTRIES Washington Orlando Irrazabal Bohorquez wirraz@ita.br Center for Reference on Gas Turbines and Energy Technological Institute of Aeronautics 12228-900 - São José dos Campos, SP, Brazil (55)12-39475911 João Roberto Barbosa barbosa@ita.br Center for Reference on Gas Turbines and Energy Technological Institute of Aeronautics 12228-900 - São José dos Campos, SP, Brazil (55)12-39476952 Luiz Augusto Horta Nogueira horta@unifei.edu.br EXCEN - Center for Excellence on Energy Efficiency Federal University of Itajuba 37500-903 - Itajubá, MG, Brazil (55)35-36291442 Electo E. Silva Lora electo@unifei.edu.br NEST- Center for Excellence on Thermal Power and Distributed Generation Federal University of Itajuba 37500-903 - Itajubá, MG, Brazil (55)35-36291355 ABSTRACT The operational rules for the electricity markets in Latin America are changing at the same time that the electricity power plants are being subjected to stronger environmental restrictions, fierce competition and free market rules. This is forcing the conventional power plants owners to evaluate the operation of their power plants. Those thermal power plants were built between the 1960´s and the 1990´s. They are old and inefficient, therefore generating expensive electricity and polluting the environment. This study presents the repowering of thermal power plants based on the analysis of three basic concepts: the thermal configuration of the different technological solutions, the costs of the generated electricity and the environmental impact produced by the decrease of the pollutants generated during the electricity production. The case study for the present paper is an Ecuadorian 73 MWe power output steam power plant erected at the end of the 1970´s and has been operating continuously for over 30 years. Six repowering options are studied, focusing the increase of the installed capacity and thermal efficiency on the baseline case. Numerical simulations the seven thermal power plants are evaluated as follows: A. Modified Rankine cycle (73 MWe) with superheating and regeneration, one conventional boiler burning fuel oil and one old steam turbine. B. Fully-fired combined cycle (240 MWe) with two gas turbines burning natural gas, one recuperative boiler and one old steam turbine. C. Fully-fired combined cycle (235 MWe) with one gas turbine burning natural gas, one recuperative boiler and one old steam turbine. D. Fully-fired combined cycle (242 MWe) with one gas turbine burning natural gas, one recuperative boiler and one old steam turbine. The gas turbine has water injection in the combustion chamber. E. Fully-fired combined cycle (242 MWe) with one gas turbine burning natural gas, one recuperative boiler with supplementary burners and one old steam turbine. The gas turbine has steam injection in the combustion chamber. F. Hybrid combined cycle (235 MWe) with one gas turbine burning natural gas, one recuperative boiler with supplementary burners, one old steam boiler burning natural gas and one old steam turbine. G. Hybrid combined cycle (235 MWe) with one gas turbine burning diesel fuel, one recuperative boiler with