variavel0=<b>Felipe Raúl Ponce Arrieta</b> - aponce@iem.efei.br Universidade Federal de Itajubá
<b>Electo Eduardo Silva Lora Lora</b> - electo@iem.efei.br Universidade Federal de Itajubá
<b>Abstract.</b> Thermal power plants have become an important matter as a part of energy supply systems, mainly because of the needing of power generation systems diversification and the availability of natural gas, the principal fuel used in this type of energy generating system. With the implementation of a Priority Plan of Thermal Power Plants in the Brazilian scenario, dozens of units will be installed which will make possible to transform the Brazilian Electric System, today mainly based in hydraulic principles into a hydro-thermal system. The operation of a thermal power plant based on combined cycle in influenced by the surrounding conditions of the place which it is to be installed, fundamentally by ambient temperature, atmospheric pressure and the air relative moisture. Those parameters happen to affect the generated electric power and the Heat Rate during the operation, and among those, ambient temperature is the one to produce the most appreciable effects in the behavior of the plant based on combined cycle. In this work the influence of the ambient temperature in the behavior of a thermal power plant based on combined cycle is study. The plant is composed of two 501F Siemens-Westinghouse gas turbine, linked with three steam pressure levels with reheat recuperated boilers with supplementary firing and a steam turbine. The most relevant results obtained from thermodynamic simulation, in which Gate Cycle Software version 5.40.0.r was used, are the curves of the generated power, as well as, Heat Rate and thermal efficiency as a function of ambient temperature and the supplementary firing after burning temperature.
<b>Keywords.</b> Electric power generation, Operation, Thermodynamics analysis, Efficiency, Heat Rate.