Thermo-economic analysis on an improved coal-fired power system integrated with S–CO2 brayton cycle

Abstract

In this work, the efficient energy utilization in the thermodynamic system of a traditional 660 MW coal-fired power plant, was achieved by incorporating S–CO2 Brayton cycle system. A thermodynamic mathematical model was established according to the basic laws of thermodynamics and was verified by using design conditions. Moreover, to minimize the irreversible losses, an additional S–CO2 Brayton cycle system was proposed under the THA condition, which increased the power generation efficiency by 0.28%, and decreased the coal consumption by 1.79 g/kwh. With the increase of the S–CO2 flow rate, a greater power generation efficiency was achieved. The outlet pressure of the S–CO2 compressor did not affect the plant load but affected the distribution of the power generation load between the steam cycle and the S–CO2 cycle. In addition, this study includes a technical-economic analysis of the proposed system. Overall, this study provides a complete picture of how to improve the efficiency of a thermal power plant.