【作者】 马丁；

【导师】 伍成波；

【作者基本信息】 重庆大学 ， 冶金工程， 2007， 硕士

【摘要】 辐射管是热镀锌板生产线上重要的加热装置,在热镀锌板生产成本中,辐射管的能源消耗占了很大比重,应用高温空气燃烧技术(HTAC)的蓄热式辐射管具有高效节能和降低污染物排放的潜力,是燃气辐射管的发展方向之一。目前国内虽然已经研发出燃气蓄热式辐射管,但就其完整性和实用性上仍旧有很多关键性的技术值得进一步研究和优化。本文以热态实验为基础,对蓄热式辐射管的烧嘴结构、换向时间、蓄热体长度等进行优化设计,优化后的烧嘴结构能够较好地混合空燃气,从而均匀了辐射管的表面温度,使温差在30℃左右;对换向时间和蓄热体长度的选择,使烟气余热回收率在75%以上,同时对所采用的蜂窝式陶瓷蓄热体的蓄热特性和蓄热能力进行了分析和计算,认为其传热系数是常规金属换热器的1.6～5倍。实验过程中重点对降低NOx排放进行了研究。将低NOx燃烧技术与蓄热式燃烧技术有机的结合起来,开发出可靠、实用的工程技术,如内衬管、“十”字型插件等,并应用在蓄热式辐射管中,得到了较好的效果。在辐射管表面温度达到其工作温度以上时(>900℃),烟气中的NOx浓度能够降低到200×10-6以下。在实验研究的同时,结合数值仿真研究工作,丰富了对辐射管内燃烧过程的认识。对蓄热式辐射管内低NOx燃烧过程进行模拟,针对不同的低NOx燃烧技术,分析对NOx抑制效果的影响,具体研究了燃料与空气混合方式的变化、助燃空气中氧浓度的变化、分级燃烧中一次空气比例及一次燃烧区域长度的变化以及燃料及空气入口相对位置的变化对NOx生成的影响,研究结果为低NOx燃烧器的优化设计提供了理论依据。同时对人们关心的蓄热式辐射管内高温空气燃烧状态下的温度场、流场及组分分布进行了模拟研究,丰富了对高温空气燃烧技术的认识和理解。更多还原

【Abstract】 Radiant tube is a important heating instruments in product line of galvanization ban. The energy cost of radiant tube take a lot place in the total cost. The regenerative radiant tubes with high temperature air combustion (HTAC) technique have potential of energy saving and low exhaust gas emission. This is the direction of radian tube development. Right now regenerative fuel radiant tube has been applied natively, but it could be optimized in the part of inteqrality and practicability.This text based on combustion experiment. The burner structure , switching time and the length of honeycomb regenerator were design optimization in the regenerative radiant tube. After optimization, the burner can make the mix of gas and fuel better according to equality the surface temperature of the radiant-tube and the difference of surface temperature limited 30℃.The selection of switching time and honeycomb regenerator make the heat recovery rate more than 75%.At the same time, this experiment had a study on the performance and capacity of the honeycomb regenerator, the result show that the heat transfer coefficient of regenerator was 1.6～5 times more than normal heat storage bed.The most important content in this paper was how to reduce the NOx emission in the working condition of radiant tube low NOx emission combustion technology and regenerative combustor technology were combined for developing dependable, practical technology in this experimental study,for example two burning zones and crossed device. The result show that in the condition of above working temperature(>900℃) the NOx emission can reduced to under 200×10-6.There were a lot of work about simulation in this text. It can strengthen and enrich the acquaintanceship of HTAC. The major study is about the effect of different technology of low NOx emission. The mostly contents contained different mix of the fuel and air, oxygen concentration in the combustion air, the influences of primary air propotion and the primary zone length, different inlet of the flue and combustion air. The study results provided the theoretical basis for optimum design of burner structure. At one time having a simulation on fluid flow gas temperature profile and oxyen concentration profile in the regenerative radiant tube. and compared to the normal air preheat combustion in order to enrich the knowledge of HTAC.更多还原