超临界二氧化碳燃煤热电联产系统热力性能及灵活性分析

To study the performance characteristic of a supercritical carbon dioxide (SCO₂) coal-fired cogeneration system and point out the direction of system performance improvement, the simulated model of the SCO2 coal-fired cogeneration system was established by Ebsilon software. The thermal performance and flexibility of the system were analyzed, and the effects of design conditions on system performance were studied. Results show that under the design condition, the energy efficiency and exergy efficiency of the system are 89.74% and 44.03%, respectively. The operating domain area of the system is 11.40 m², which is 93.55% higher than that of the traditional system. When the compressor inlet pressure is selected at 7.6 MPa, the system has higher exergy efficiency and better flexibility. When the compressor inlet pressure is selected at 11.2 MPa, the system has higher energy efficiency and better flexibility. Under the off-design condition that the heat supply split coefficient is less than 1, the thermal performance of the system could be improved by decreasing the precooler outlet temperature. To improve the system flexibility, the scheme to increase the maximum permissible flow rate of the system is preferred.