Performance and thermoeconomics of solar-aided double-reheat coal-fired power systems with carbon capture

摘要

To offset the power losses caused by the large energy consumption of carbon capture systems in coal-fired power systems, integrating a solar energy system is regarded as a prospective choice. Two scenarios for integrating a solar energy system and carbon capture system for a representative double-reheat coal-fired power system are proposed in this study. Matrix models are established to examine the thermal performance of the coupled system, and a comprehensive investigation of the external fuel exergy contribution, parameter sensitivity, investment cost, and system optimisation is performed. Results reveal that both scenarios improve the thermal performance of the system. The thermoeconomic and exergy evaluation indicators in scenario I are less competitive than those in scenario II. Compared with scenario II, however, the economy of scenario I is superior, and the potential of investment and utilisation is more competitive. When optimizing scenario II, under the ratio of the heat from the solar system to that required by the reboiler of phi = 0.3, the coupled system presents better thermal performance and reasonable irreversible degree, and the selection of phi = 0.3 is conducive to investment and economic benefits. (C) 2019 Elsevier Ltd. All rights reserved.