中文摘要：

针对国内某电厂1 000 MW超超临界二次再热机组的火用分布情况进行了研究.利用ASPEN PLUS软件建立机组模型,根据火用平衡方程,计算火用损失和火用效率,确定系统中能量损失的主要部位,为该电厂的运行优化和节能技术改造提供科学依据.研究结果表明：锅炉炉内燃烧火用损最大,其次是炉内换热面;汽轮机火用损主要集中在超高压缸和低压缸;该机组回热加热系统的火用效率较常规机组火用效率高约2.8%;低压缸更低的排汽参数使该机组凝汽器火用损约是常规一次再热机组的50%,能级利用更加合理.

英文摘要：

The performance of a 1 000 MW double reheat ultra-supercritical（USC）power plant was evaluated.An exergy analysis was performed to direct the energy loss distribution of this steam cycle and the unit model was established by the software ASPEN PLUS.The exergy balance equation,the exergy loss and the exergy efficiency were established and calculated.The main points of exergy loss in the power plant were determined,in order to provide insights of work capacity and energy-saving optimization of the double reheat USC unit.The results show that the biggest exergy loss occurred in furnace is caused by combustion of fuel and followed by heat exchange of water wall.The exergy loss of turbine mainly focuses on the very high pressure turbine and the low pressure turbine.The exergy efficiency in this type unit is 2.8% higher than that in traditional units.The low pressure turbine allow lower exhaust steam parameter,lead to the exergy loss in condenser is reduced by half than in single reheat unit,and the utilization is more reasonable.