供能方式对钙基吸收剂循环煅烧/碳酸化法捕集CO_2热力性能的影响

Influence of Energy Supply Mode on Thermodynamic Performance of CO_2 Capture Systems With Ca-based Sorbent Cyclic Calcination/Carbonation Reaction

控制和减缓化石能源燃烧所排放的CO2对于缓解全球气候变暖具有重要意义。以某超超临界1 000 MW火力发电机组为例,建立了钙基吸收剂循环煅烧/碳酸化法捕集CO2的系统流程,基于Aspen Plus软件得到了系统的热力性能,分析了太阳能集热和煤富氧燃烧驱动CaCO3煅烧反应对系统热力性能的影响。结果表明,与煤富氧燃烧方案相比,太阳能集热方案增加了发电功率,发电标准煤耗率降低1/3,但其发电热效率降低3.8个百分点;太阳能集热方案的等效太阳能热发电效率为28.36%,高于塔式太阳能热发电的峰值效率;提升太阳能集热方案性能的关键是提高集热器场的能量利用效率sol-avi,当sol-avi高于75%时,太阳能集热方案比煤富氧燃烧方案发电热效率高。所得结论为低能耗减排CO2、高效利用太阳能提供了新途径。

Capturing CO2 from fossil fuel combustion is of importance in the CO2-constrained world for mitigation of climate warming. Take an ultra-supercritical 1000MW power plant as an example, the flow sheet of CO2 capture system with Ca-based sorbent cyclic calcination/carbonation reaction was built, and the thermodynamic performance of CO2 capture system was obtained by the help of Aspen Plus software. The influence of CaCO3 calcination reaction heat supplied by concentrated solar power or coal oxy-fired on thermodynamic performance was also analyzed. The results show that compared with coal oxy-fired scheme, concentrated solar power scheme increases the output power, decreases standard coal consumption rate by 1/3, but thermal efficiency of power generation is decreased by 3.8 percentage points. The equivalent solar thermal power efficiency of concentrated solar power scheme is 28.36%, which is higher than peak efficiency of solar tower power plant. The key factor to increase thermodynamic performance of concentrated solar power scheme is energy utilization efficiency （rhol_avi） of the solar collector field. As ηsol-avi〉75%, power generation efficiency of concentrated solar power scheme is higher than that of coal oxy-fired scheme. The conclusions supply new schemes for low energy consume of CO2 capture and high efficiency utilization of solar power.