静止气氛中单碳粒燃烧非稳态过程的影响因素  

Influence Factors on Unsteady Process of Single Carbon Particle Combustion in Static Atmosphere

作　　者：王勇[1] 李君[1] WANG Yong;LI Jun(School of Mechanical Engineering,Tianjin University,Tianjin,China,Post Code:300072)

机构地区：[1]天津大学机械工程学院,天津300072

出　　处：《热能动力工程》2023年第10期130-137,共8页Journal of Engineering for Thermal Energy and Power

基　　金：国家自然科学基金外国青年学者基金(51850410504)。

摘　　要：针对单个碳颗粒在静止气氛中的燃烧过程,进行了包括详细的物理和化学模型在内的瞬态数值模拟。研究了粒径收缩、初始粒径(50~200μm)、环境氧气的体积分数(9%~21%)和气相温度(1 200~1 600 K)对燃烧过程的影响。结果表明:碳粒燃烧过程中,碳粒表面温度先逐渐升高后迅速下降至环境温度,峰值温度出现在碳粒半径为35~45μm的范围内;碳粒收缩过程符合d_(2)定律,推导得到的碳粒单位面积燃烧速率φ与粒径r_(s)的反比例关系式可用于对碳粒燃烧速率的预测计算;碳粒燃烧过程的特征值只取决于当前的颗粒直径,与其先前的演变过程无关;碳粒粒径越小,温度越低,化学动力学对燃烧过程的控制能力越强;初始碳粒半径相同时,升高气相温度或环境氧气的体积分数不会改变燃烧过程特征值的基本变化趋势,燃烧速率和碳粒表面温度均随气相温度或环境氧气体积分数的增大而增大,其中气相温度升高会导致碳粒表面温度达到峰值时的粒径减小。The transient numerical simulation of the combustion process of a single carbon particle in a static atmosphere was carried out, including detailed physical and chemical models. The effects of particle radius shrinkage, initial particle radius (50-200 μm), volume fraction of ambient oxygen (9%–21%) and gas phase temperature (1 200-1 600 K) on the combustion process were studied. The results show that in the process of carbon particle combustion, the carbon particle surface temperature increases gradually and then decreases rapidly to the ambient temperature, the peak temperature occurs in the range of carbon particle radius of 35-45 μm;the carbon particle shrinkage process accords with the d_(2) law, the inverse proportional relationship between the combustion rate per unit area of carbon particles and particle size can be used to predict the combustion rate of carbon particles;the characteristic value of carbon particle combustion process only depends on the current particle diameter and has nothing to do with its previous evolution process;the smaller the carbon particle size is and the lower the temperature is, the stronger the chemical kinetics is to control the combustion process;when the initial carbon particle radius is the same, the increase of gas phase temperature or volume fraction of ambient oxygen will not change the basic variation trend of characteristic values of the combustion process, the combustion rate and carbon particle surface temperature both increase with the increase of gas phase temperature or volume fraction of ambient oxygen, in which the increase of gas phase temperature will lead to the decrease of the particle size under the peak carbon particle surface temperature.

关 键 词：碳粒 燃烧速率 表面温度 粒径收缩 非稳态进程 

分 类 号：TK16[动力工程及工程热物理—热能工程]