混煤对二次再热锅炉汽温特性的影响

Steam Temperature Adjustment Characteristics of Double Reheat Boiler under Different Coal Blending

超超临界二次再热锅炉热力系统复杂,二次再热锅炉的主蒸汽温度、一次再热蒸汽温度和二次再热蒸汽温度控制较复杂。针对某660 MW塔式二次再热锅炉在运行中不同掺烧条件下运行情况,研究二次再热机组主蒸汽和一二次再热蒸汽温度不同调温手段下变化规律。采用火电厂热力仿真软件Thermoflow和前苏联98年热力计算标准,研究燃用不同掺烧煤种时,锅炉摆动燃烧器、烟气再循环率和烟气挡板开度对该超超临界二次再热锅炉汽温特性的影响。通过针对摆动燃烧器、烟气再循环和分隔烟道挡板等调温手段对锅炉汽温特性影响,研究超超临界二次再热锅炉在不同负荷阶段,调温手段对汽温的影响特性,为实际运行控制中建立摆动燃烧器调整、烟气再循环和烟道挡板等调温手段耦合作用下二次再热锅炉调温方法,实现主蒸汽、一次再热和二次再热蒸汽温度的耦合汽温调整方法。

The thermal system of the ultra-supercritical double reheat boiler is complicated,and the control of the main steam temperature,primary reheat and secondary reheat steam temperature of the double reheat utility boiler is comprehensive.Based on the operation of a 660 MW tower double reheat utility boiler under different blending conditions,this paper studies the variation law of the temperature of the main steam,primary and secondary reheating steam under different steam temperature regulating methods.The simulation software of thermal power plant Thermoflow and thermal calculation method were applied to investigate the influence of tilting burner,flue gas recirculation and flue gas baffle openings on the steam temperature characteristics of ultra-supercritical double reheat boilers when different coal blending were burning.This research investigated the influence characteristics of various combined temperature adjustment methods on steam temperature at different load phases and provided a coupling method for steam temperature adjusting methods such as tilting burners,flue gas recirculation,and flue baffles under practical operation condition to meet the temperature operating requirements of the coupling method of the main steam,primary and secondary reheat steam.