大型乙烯裂解炉用低NO_(x)燃烧器的结构优选

Structure Optimization of Low NO_(x)Burners for Large Ethylene Cracking Furnaces

随着大能力大型化裂解炉的不断发展,国内首台单炉膛20万吨/年产能乙烯裂解炉对燃烧器提出了更高的设计要求,在稳定燃烧的同时还要满足特定的工艺要求和严苛的环保要求。采用CFD技术和热态试验方法优选新型乙烯裂解炉用低NO_(x)燃烧器,通过数值分析方法研究不同底部与侧壁供热比(底侧比)下裂解炉内的燃烧状态(火焰形状、火焰长度、炉内温度分布及NO_(x)排放量等),结果表明:在底侧比为70:30时燃烧状态最优,炉膛内温度分布均匀且满足工艺要求和环保要求。在热态试验炉上对最终设计工况(底侧比72:28)进行热态试验,结果显示:炉内燃烧状态良好,温度分布均匀且满足热通量曲线,NO_(x)排放量也较低。

With the continuous development of large-capacity and large-sized cracking furnaces,the higher requirements for the burner design of the first 200 kt/a ethylene cracking furnace with single furnace in China was proposed,including meeting specific process requirements and increasingly stringent environmental requirements while keeping stable com bustion.In which,both CFD technology and hot test method were adopted to develop a new low NO_(x)burner for the ethylene cracking furnace.Numerically analyzing the combustion state(flame shape and length,temperature distribution and NO_(x)emission)within the cracking furnace at different bottom-side heating ratios(bottom-side ratio)shows that,the bottom-side ratio(70:30)is optimal and the temperature distribution there is uniform and it meets the requirements of technology and environmental protection;the final design conditions(72:28)implemented on the hot test furnace shows that,the combustion within the furnace is in good condition together with uniform temperature distribution,ideal heat flux curve and low NO_(x)emission.