高海拔条件下轻质油燃烧器出口配风结构适配性研究

Study on the Adaptability of Air Distribution Structure at the Outlet of Light Oil Burner at High Altitude

一般燃烧器用于高海拔条件会出现一系列燃烧问题,为了对燃烧器配风结构进行缩短火焰长度的适应性改进,本文设计了旋流叶片式和平板开槽式两类稳焰盘结构,数值分析稳焰盘下游流场结构并进行比较,在低气压条件进行了裸烧试验,并对原燃烧筒直径进行适配分析。研究结果表明:额定工况下轻油燃烧器的出口流场雷诺数大于临界雷诺数10^(4),处于第二自模化区内,因此可用冷态流场模化热态燃烧场;根据稳焰盘周围流场结构数值分析结果,认为螺旋扭曲叶片倾角β越小,回流气量越大,倾斜曲面叶片对气流有明显的旋流引导作用;与旋流叶片式稳焰盘相比,平板开槽式稳焰盘结构改动小、所形成的回流区更大、裸烧火焰更短、不易积碳,更加适合高海拔条件使用;将燃烧筒直径从78 mm增大到90 mm,可使旋流气流充分发展,再聚拢生成较大回流区。该结论为高海拔条件下燃烧器配风器适配设计改进提供实际参考。

A series of combustion problems will occur when general combustors are used in high altitude environment.In order to adaptively modify the burner air distribution structure to shorten the flame length,two types of flame stabilizers,swirl vane type and flat slotted type,were designed,the downstream flow field structure of the flame stabilizer was numerically analyzed and compared.The naked burning test was carried out in hypobaric environment,and the adaptation analysis of the original combustion cylinder diameter was made.The results show that the Reynolds number of the outlet flow field of the light oil combustor is greater than the critical Reynolds number 10^(4) under rated working conditions and is in the second self modeling zone,so the cold flow field can be used to simulate the hot combustion field;According to the numerical analysis results of the flow field structure around the flame stabilizer,it is considered that The smaller the inclination angle of spiral twisted bladeβ,the larger the return flow,and the inclined curved blade has an obvious swirling guiding effect on the airflow;Compared with the swirl vane flame stabilizer,the flat slotted flame stabilizer has less structural change,larger reflux area,shorter naked burning flame and less carbon deposition,so it is more suitable for plateau environment;Increasing the diameter of the combustion cylinder from 78 mm to 90 mm,the swirling flow can be fully developed and then gathered to form a large reflux area.This conclusion provides a practical reference for the improvement of adaptation design of combustor air distributor at high altitude.