小型回流燃烧室多工况碳黑分布预测

Prediction of Carbon Black Distribution in Multi-Stateof Small-Scale Reverse Flow Combustor

关键词:  燃烧室  多工况  碳黑分布  数值计算  湍流燃烧

Key words:  Combustor  Multi-station  Carbon black particles distribution  Numerical calculation  Turbulent combustion

摘要:

为了研究小型回流燃烧室不同条件下的工作状态，并分析其产生积碳现象的原因，采用k-ε湍流模型、EDC湍流燃烧等模型对该燃烧室多个工况进行数值计算。结果表明，燃烧室性能参数计算值与台架数据较吻合，各个状态下参数相对误差均小于1.37%。根据各工况的温度分布的变化，发现燃烧室火焰随工况降低逐渐向火焰筒头部收缩。计算了各工况蒸发管内的燃油蒸发率，发现蒸发率在低工况时明显降低。根据出口温度分布情况，计算出口温度分布系数OTDF为0.35。分析碳黑粒子的分布，发现积碳现象主要在火焰筒头部，其原因主要是燃烧不充分和冷却气膜的缺失。

Abstract:

In order to study the working conditions of small reflux combustor under different conditions and analyze the causes of carbon deposition, k-ε turbulence model, EDC combustion model are used to simulate the flow field of the combustor. The results show that the calculated values of the parameters of the combustor are in good agreement with the bench test data. The relative error of the parameters in each state is less than 1.37%. According to the temperature distribution of each working condition, it is found that the flame of the combustor gradually shrinks toward the head of the flame tube as the working condition decreases. The evaporation rate of the fuel in the evaporation tube of each working condition was calculated, and it was found that the evaporation rate was significantly reduced under low working conditions. According to the temperature distribution of the outlet, the outlet temperature distribution coefficient (OTDF) was calculated to be 0.35. According to the distribution of carbon black, it is found that the carbon deposit is mainly in the head of flame tube, mainly due to insufficient combustion and lack of cooling film.