分区分级燃气辐射管模型验证及仿真研究

本文首先对双P型辐射管进行实验和数值研究,发现除NOx含量的误差偏大外,其他参数的偏差都在1%以内,证明该模型具有一定的可靠性.在此基础上,将空气分级的理念应用于双P型辐射管,提出一种带支管喷口的分区分级燃气辐射管,并建立相应的数学和物理模型.对比双P型辐射管和分区分级辐射管的模拟结果显示：分区分级燃气辐射管和双P型辐射管内气体的平均流速分别为25.8 m·s-1和21.0 m·s-1,热效率分别为65.9%和64.2%；分区分级燃气辐射管壁面最高温度为1047℃,壁面最大温差为73℃,比双P型辐射管降低15℃,分区分级后气体平均流速增大,提高了直管和回流管管段的烟气温度和壁面温度,具有更好的温度均匀性.

Model validation and simulation studies on zoned and staged gas fired radiant tubes

Experimental and numerical studies on double P-type radiant tubes were performed in this article firstly. According to the results, it is found that the deviations of parameters are within 1% except the NOx concentration with big error, indicating that the model has certain reliability. Based on this, the concept of air classification was applied to double P-type radiant tubes, a gas-fired radiant tube with branch pipe nozzles was introduced, and the corresponding mathematical and physical models were verified in this paper. Simulation results show that average flow velocities of the zoned and staged gas-fired radiant tube and the double P-type gas radiant tube are 25. 8 m·s-1 and 21. 0 m·s-1 , and the thermal efficiencies are 65. 9% and 64. 2%, respectively. The highest wall surface temperature of the zoned and staged gas fired radiant tube is 1047℃, and the maximum wall temperature difference is 73℃, 15℃ less than that of the double P-type radiant tube. The gas average flow velocity increases after being zoned and staged, and the flue gas temperature and wall temperature of the straight pipe and backflow connection rises with a better uniformity of temperature.