大型煤制烯烃工程蒸汽动力系统研究

Research on steam power system in larger scale coal to olefin plant

为了解决煤制烯烃工程蒸汽动力系统存在的参数低、煤耗高、备用量大、管网不平衡等影响系统大型化的关键性问题,对运行中系统的数据进行了分析,通过引入超临界燃煤机组和总管制蒸汽管路等方法,提出了一种适应于更大规模煤制烯烃工程的蒸汽动力系统设计形式。在120万t/a煤制系统工程蒸汽动力系统设计中,配置2台350 MW超临界燃煤机组,结合8~9级回热和1级再热系统,可以将系统供电煤耗降低从450 g/k Wh降低到320 g/k Wh。利用机组间总管制的蒸汽管道可以实现蒸汽管网的灵活切换,在"零备用"条件下满足年运行8 000 h以上的高可靠性要求。系统发电出力不仅可以满足煤制烯烃工程自用要求,还可以向周围电网输出255 MW。该系统具有良好的扩展性,可以随煤制烯烃工程规模的变化灵活配置,满足未来更大规模工程的需求。

In order to solve the problems of steam power system in coal to olefins（ CTO） project,like low steam parameters,high coal consumption and standby capacity,network imbalance,the characteristics of steam power system were analyzed. By introducing supercritical coal power units and a manifold steam pipe system,a new design concept in large-scale CTO project was presented. In a 1. 2 Mt/a CTO steam power system,a combination of two 350 MW supercritical coal power units with 8-9 regenerative and 1 reheat system,reduced coal consumption rate from 450 g/k Wh to 320 g/k Wh.A manifold steam pipe system helped to achieve flexible switching between units,to meet a 8 000 h/a high reliability standard with zero standby.System power output met the requirements of CTO project,and it could serve 255 MW to power grid.The system had good expansibility to meet different scale of the CTO project in the future.