低NOx高温空气燃烧技术将传统的低NOx燃烧技术与高温蓄热式燃烧系统有机地结合起来，具有热效率高、炉内温度分布均匀、NOx排放量低等特点。本文介绍了高温空气燃烧技术，重点分析了高温空气燃烧技术中的低NOx排放的原理，并对两种采用烟气再循环和分级燃烧技术的低NOx高温空气燃烧器进行阐述。

High temperature air low fuel gas concentration combustion is proposed in this paper, which developed from high temperature air combustion. From the view of engineering application, the velocity of combustion air jet would not be very high because of the resistance of exhausting flue gas when the air port was used as exhausting flue gas port. Thus, the fuel gas jet velocity would be high so as to entrain the ambient flue gas in furnace. And the burner configuration would be designed to make the fuel gas jet entrain flue gas easily. The effects of fuel gas jet velocity and burner configuration on NOX emission in high temperature air combustion were studied by numerical simulation. The results show that NOX emission reduced with the fuel gas jet velocity increasing. In addition, NOX emission reduced drastically when six circle air ports around fuel gas port were converted to two rectangle air ports because the fuel gas jet could entrain much more flue gas before ignition.

The numerical simulations of high temperature air combustion (HiTAC) for burning low heat value gas have been carried out. The standard k-e turbulent model with a wall function, assumed β probability function density (PDF) combustion model, discrete ordinates (DO) radiation model and thermal NOX model were used in the simulation. The simulation results indicated that both the burner structure and operation parameters played important roles on combustion temperature field and NOX emission, and that the flame temperature and NOX emission decreased with the reduced preheated combustion air temperature and the increased heat flux through furnace wall. Simulated high NOX concentration field was predicted to be outside of flame, which was in agreement with experimental results. Delaying the mixing of combustion air stream and fuel gas stream in HiTAC would decrease the maximum flame temperature and NOX emission.

对某发电厂300MW单炉体双炉膛直流锅炉的煤粉颗粒运动轨迹进行了数值模拟研究，结果表明：小煤粉颗粒的运动轨迹与炉内旋转气流基本一致，而中、大煤粉颗粒因气流对其的作用力不足以提供做旋转运动的向心力，故在热角区域气流急剧转弯时撞击在水冷壁上；由此分析了该锅炉烟气侧水冷壁高温腐蚀的某些原因，提出了改造方案. 模拟结果显示：降低一次风喷口高度、加宽喷口宽度、采用水平浓淡风煤粉燃烧器，可以提高一次风射流的刚性，避免煤粉颗粒撞击在热角区域的水冷壁上，从而减少高温腐蚀的发生，改造后的性能测试结果表明，改造方案切实可行，取得了良好的运行佳绩。