Currently the main economic evaluation methods of the thermal power plants are: energy equilibrium
method based on the first law of thermodynamics, exergy analysis method based on the second law of
thermodynamics, and the new cross-disciplinary thermoeconomic method. Energy equilibrium method,
due to its inherent defect (only Energy conservation involved, but qualitative aspect [1]), has been
abandoned gradually in many fields. Among the methods based on second law of thermodynamics, exergy
analysis method is most widely used. This paper quotes from “fuel” and “product” concept of
thermodynamic suggested by Spanish scholar A.Valero to analyze a 300MW power plant for evaluating its
equipments function.