MILD氧燃烧技术是由MILD燃烧技术发展而来的一种更加节能减排的技术.为了找到一种更有利于MILD氧燃烧实现的喷嘴结构,本文设计了一种单侧倾斜的喇叭口喷嘴,通过改变非对称喷嘴喇叭口开口方向设置了4种不同的喷嘴结构,在各种参数相同的条件下进行了数值模拟研究,并通过速度场与涡量场、组分场、温度场几个方面对非对称喷嘴进行了对比分析.结果表明:非对称射流喷嘴可以将射流气体打散成诸多小体积微团,不同喷嘴结构中大动量喷嘴倾斜角方向影响流场的偏移方向,且影响回流区域的分布;其中喷嘴倾斜面向外放置的喷嘴结构打散气流产生的小体积微团扩散效果最好,CO体积分数最小,回流烟气对O2稀释效果最好,温度分布最均匀,最有利于MILD氧燃烧的实现.%MILD oxygen combustion technology is a more energy-saving and emission-reducing technology developed from the MILD combustion technology. In order to find a nozzle structure that is more conducive to MILD oxygen combustion, this article has designed a unilateral inclined bell mouth nozzle. Four different nozzle structures were set up by changing the direction of the opening of the asymmetric nozzle horn, and numerical simulations were performed under the same conditions for various parameters. Moreover, from the aspects of speed field, vorticity field, component field and temperature field, the asymmetrical nozzles were analyzed. The results show that, the asymmetric jet nozzles can disperse the jet gas into many micelles with small size. The direction of inclination of the large momentum nozzles in different nozzle structures affects the direction of the flow field and the reflow area. For the nozzle with structure that the inclined surface placed outwards, the diffusion of small size micelles resulting from the dispersion of the airflow is the best, the CO concentration is the minimum, the reflux flue gas has the best O2 dilution effect, and the temperature distribution is the most uniform, so nozzle with this structure is most beneficial to the realization of MILD oxygen combustion.
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