In this paper, the flame characteristics of co-axial concomitant flow diffusion combustion of low calorific value gas under the action of thermal dynamics are studied. Based on Fluent software, the combustion process of low calorific value gas is simulated by a finite element volume method. According to different air preheating temperatures , by analyzing the changes of temperature field, velocity field and concentration field during combustion and solving the curve fitting equation of velocity field, the changing trend of the flame core, inner flame and outer flame with air preheating temperature is obtained. The results show that the flame front temperature decreases with the increase of when low calorific value gas is burned; the flame core and the inner flame length shorten with the increase of . When rises from 300 K to 500 K, the flame core and the inner flame shorten by 0.05584 and 0.05867 m respectively, with the increase of , the length of the flame outer flame increases first and then decreases. when , the flame outer flame is the longest with the maximum value of 0.78865 m m. When , The value corresponding to the zero-boundary point position of the equivalence ratio of combustion reaction is the largest, and the maximum value is . Therefore, when , the flame outer flame length is the longest, the mixing area of combustible gas and air is the largest, the flame front temperature is higher during combustion, and the combustion effect is the best.

中文翻译：

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热力学作用下低热值气体扩散燃烧火焰特性分析

本文研究了低热值气体在热力学作用下同轴伴流扩散燃烧的火焰特性。基于Fluent软件，采用有限元体积法模拟低热值气体的燃烧过程。根据不同的空气预热温度，通过分析燃烧过程中温度场、速度场和浓度场的变化，求解速度场的曲线拟合方程，得到火焰核心、内焰、外焰随空气预热温度的变化趋势为获得。结果表明，低热值燃气燃烧时，火焰锋面温度随温度升高而降低；火焰核心和内火焰长度随着 的增加而缩短。当从 300 K 上升到 500 K 时，火焰核心和内焰分别缩短了0.05584和0.05867 m，随着 的增加，火焰外焰的长度先增大后减小。时，火焰外焰最长，最大值为 0.78865 m·m。时，燃烧反应当量比零边界点位置对应的值最大，最大值为 。因此，当 时，火焰外焰长度最长，可燃气体与空气的混合面积最大，燃烧时火焰前沿温度较高，燃烧效果最好。火焰外焰最长，最大值为0.78865 m·m。时，燃烧反应当量比零边界点位置对应的值最大，最大值为 。因此，当 时，火焰外焰长度最长，可燃气体与空气的混合面积最大，燃烧时火焰前沿温度较高，燃烧效果最好。火焰外焰最长，最大值为0.78865 m·m。时，燃烧反应当量比零边界点位置对应的值最大，最大值为 。因此，当 时，火焰外焰长度最长，可燃气体与空气的混合面积最大，燃烧时火焰前沿温度较高，燃烧效果最好。