Thermo-economics analysis method of thermal system for power unit with double reheat

Based on the equivalent enthalpy drop theory, the mathematical models for calculating equivalent enthalpy drop, efficiency and heat absorption of the regeneration extraction steam were established according to the characteristics of thermal systems of supercritical pressure power units. Then the rules for analyzing the economy of thermal system changes were presented. The correctness was verified by an example. The result shows that the proposed economy analysis method is easy to be used for calculating the index change of supercritical pressure power units.