Thermal system for comprehensive utilization of boiler and steam turbine energy of coal-fired power units based on the S-CO2 cycle

Abstract

In this study, an additional S-CO2 cycle system configuration for coal-fired power units has been proposed. This system achieves cascade utilization of steam turbine extraction and boiler flue gas energy, to improve the coal-fired power unit generation efficiency. Thermodynamic analyses were carried out for the new thermal system based on energy and exergy analyses. The results show that under the turbine heat acceptance (THA) condition, the proposed thermal system could reduce the standard coal consumption rate by 0.91% in coal-fired power units. Furthermore, the factors affecting the system performance are analyzed, and the effect laws of various elements on the total investment and payback period are derived. The suggested thermodynamic system provides a method for using energy on both sides of the boiler and steam turbine.

Keywords

• S-CO2 cycle
• Coal-fired power unit
• Irreversible loss
• Techno-economic analysis