Method for analysis the economics of a thermal system in a supercritical pressure power unit with double reheat cycles

Based on the theory of equivalent enthalpy drop and aiming at the supercritical pressure unit with double reheat cycles, a set of mathematical models for calculating equivalent enthalpy drop and efficiency of regeneration cycle are established. Through a strict theoretical analysis and mathematical formulation, a calculating method for the equivalent enthalpy drop of nominal and real extractions is obtained, and the principles for local quantitative analysis of the economics for the thermal system of supercritical pressure unit with double reheat cycle are given. A set of complete quantitative calculating methods is formed in which by using the model, only 3 equations are needed and result in a fast and convenient calculation the economics changes of the system during a local adjustment and changes of the criterion, and provides an accurate method for the economics analysis and energy-saving diagnosis for such kind of units. A practical case study has proved the feasibility and accuracy of the model.