为研究火电机组深度调峰过程中，锅炉低负荷燃烧的稳燃和最佳的安全、高效运行方式，依托某电厂亚临界660 MW机组，对亚临界强制循环四角切圆锅炉在超低负荷（20%）下的稳燃性能进行了试验研究和数值模拟计算，对低负荷下燃烧运行工况优化进行了研究。研究结果表明：某电厂3号机组锅炉在低负荷燃烧时，能保持较高的煤粉燃尽率，炉膛最高温度可以达到1 400~1 600 K左右，运行O2体积分数为12%~13%左右，低负荷燃烧较为稳定；运行选择较为靠近炉膛上部的磨组运行方式、调整AA托底风门开度5%~10%、燃烧层之间辅助风门开度维持在9%~18%以及燃烧层周界风门开度约为18%等燃烧优化手段可以实现低负荷下的合理空气动力场，维持稳定燃烧。

In order to study the stable combustion of lowload combustion and the best safe and efficient operation mode of the boiler during the deep peak shaving of thermal power units, relying on the subcritical 660 MW unit in a power plant, the experimental research and numerical simulation of stable combustion performance of a subcritical forced circulation quadrangular tangentially rounded boiler at 20% ultralow load were carried out. The optimization of combustion operation condition at low load was studied. The research results show that the boiler of No.3 unit in a power plant can maintain a high pulverized coal burnout rate when burning at low load. The maximum furnace temperature can reach around 1 400 to 1 600 K, and the operating oxygen volume fraction is about 12% to 13%, showing that the low load combustion is relatively stable. By using operating methods of selecting the grinding unit close to the upper part of the furnace, adjusting the AA bottom air valve opening of 5% to 10%, maintaining the auxiliary air valve opening between the combustion layers of 9% to 18%, and keeping the air valve opening around the combustion layer of 18%, the combustion optimization means can realize reasonable aerodynamic field at low load and maintain stable combustion.

TK221

国家重点研发计划（2019YFB1505403）