摘 要：直流锅炉机组在自动发电控制（Automatic Generation Control,AGC）投入时存在负荷调节响应慢、主汽压力波动大、反应延迟等问题，尤其是低氮改造后，锅炉升降负荷过程中易出现蒸汽温度大幅波动、管壁超温的现象。以某600 MW超临界机组和1 000 MW超超临界机组直流锅炉为研究对象，分析了升降负荷过程中蒸汽温度大幅度波动的原因，并运用“稳态燃烧调整+动态汽温特性+控制参数修改”的调整方法，控制参数优化设置后，600 MW超临界机组在升降负荷过程中蒸汽温度波动在12 ℃以内，1 000 MW超超临界机组在升降负荷过程中蒸汽温度波动幅度在24 ℃以内，较优化前明显改善，优化成效显著。

Abstract:There are some problems with the use of AGC in the once-through boiler unit,such as slow response of load regulation,large fluctuation of main steam pressure and delay in response.Especially after the low NOx transformation,the heat distribution on the heating surface of the boiler changes,and the unit is prone to steam temperature fluctuations and wall over-temperature phenomena in the process of changin load.In this paper,a 600 MW supercritical unit and an ultra supercritical 1 000 MW unit boiler were studied.The reasons of steam temperature fluctuations in the process of changing load were analyzed.A novel adjustment method,“steady combustion adjustment + dynamic steam temperature characteristics + modification of control parameters”,was put forward.With the optimized settings of the control parameters,the steam temperature fluctuation range of 600 MW supercritical unit is less than 12 ℃ during the load changing,and it is less than 24 ℃ for 1 000 MW super supercritical unit,significantly improved compared to before optimization.This study is expected to provide a reference for the study of steam temperature dynamic characteristics of the same type of units after low NOx burner retrofit.

TK229