分区分级双P型辐射管喷口结构位置特性

为了对分区分级双P型燃气辐射管喷口结构、位置进行优化,提高燃烧效率.首先对分区分级双P型燃气辐射管进行了实验和数值研究,结果发现,除NOx体积分数的误差为11.6%外,其他参数的偏差都在1%以内,证明该模型具有可靠性.在此基础上,通过研究主管和支管的喷口位置及喷口结构等参数,进行了气体温度和壁面温度的研究分析.结果显示:随着主管喷口位置向外移动,分区分级燃气辐射管表面温度的最高值逐渐减小,壁面温度的最低值逐渐增大.支管喷口位于三通管与支管交线处时,可以减少高温气体对辐射管管壁的冲击作用,提高支管径向的温度均匀性,延长辐射管使用寿命;主管喷口的形式为完全预混式喷口时,壁面温差最小;支管喷口的形式为不对称式时,分区分级燃气辐射管壁面温差最小,燃烧热效率最高.

Location characteristics of the nozzle structure in the double P-type radiant tube

To optimize combustion efficiency, the structural characteristics of the zoned and staged double P-type gas-fired radiant tube were improved. The corresponding experimental and numerical studies were performed on the new radiant tube and the results show that deviations in the monitoring parameters are less than 1%, except for a NOx concentration of 11. 6%, which proves the relia-bility of the model. On this basis, the gas and wall temperatures were compared by changing the nozzle position and structure parame-ters of main and branch pipes. The results show that as the nozzle position moves outward, the highest value of the surface temperature of the radiant tube gradually decreases and the minimum value of the wall temperature gradually increases. When the nozzle of the branch pipe locates at the intersection of the tee and branch pipes, it helps to reduce the impact of the high temperature gas on the pipe wall, improve the uniformity of the branch radial temperature, and prolong the service life of the radiation tube. When the nozzle is fully premixed, the temperature difference is minimized. When the pipe nozzle is asymmetric, the difference in the wall temperatures is minimized and the thermal combustion efficiency is the highest.