直流燃烧器参数对氧煤燃烧特性的影响
发布时间：2018-10-30 15:30
【摘要】：以Φ200 mm×2 m的火焰炉为对象,借助软件FLUENT研究了在O_2/CO_2气氛下燃烧器射流动量比和射流间距的改变对炉内流场特性和燃烧特性的影响.结果表明:当射流动量比由28增至66时,烟气内循环率峰值呈现先增大后减小的趋势,混合区烟气内循环率的整体水平是在射流动量比为48时最大;随着射流间距的增大,Oxz轴面回流区向下游偏移,且氧气质量分数高于10%的区域逐渐缩小,燃烧峰值有所降低,当射流间距增至75mm时,Oxz轴面回流区的范围明显缩小,反应区氧气体积分数回升,使得燃烧峰值升高.同轴射流方式下的燃烧峰值最高,约2 200K,仅当射流间距为60mm工况下的炉膛燃烧最大温升小于煤粉的着火温度(790 K),即可实现氧煤MILD(moderate or intensive low oxygen dilution,温和)燃烧.
[Abstract]:Taking 桅 200 mm 脳 2 m flame furnace as an object, the influence of the ratio of jet flow momentum and jet spacing of burner in O_2/CO_2 atmosphere on the flow field and combustion characteristics in the furnace was studied with the help of software FLUENT. The results show that when the ejection momentum ratio increases from 28 to 66, the peak value of flue gas circulation rate increases first and then decreases, and the overall level of the internal circulation rate of flue gas in the mixed region is the highest when the emission-momentum ratio is 48. With the increase of jet spacing, the circumfluence zone of Oxz axis is shifted downstream, and the region with oxygen mass fraction higher than 10% is gradually reduced, and the combustion peak value is decreased. When the jet spacing increases to 75mm, the range of Oxz axial reflux region is obviously reduced. The increase of oxygen volume fraction in the reaction zone increases the combustion peak. The peak value of combustion in coaxial jet mode is about 2200kg. only when the maximum temperature rise of furnace combustion is less than the ignition temperature of pulverized coal (790 K), the combustion of oxygen-coal MILD (moderate or intensive low oxygen dilution, can be realized when the jet spacing is 60mm.
【作者单位】： 同济大学机械与能源工程学院;
【基金】：上海市科委资助项目(13DZ2260900)
【分类号】：TK16
，
本文编号：2300401
[Abstract]:Taking 桅 200 mm 脳 2 m flame furnace as an object, the influence of the ratio of jet flow momentum and jet spacing of burner in O_2/CO_2 atmosphere on the flow field and combustion characteristics in the furnace was studied with the help of software FLUENT. The results show that when the ejection momentum ratio increases from 28 to 66, the peak value of flue gas circulation rate increases first and then decreases, and the overall level of the internal circulation rate of flue gas in the mixed region is the highest when the emission-momentum ratio is 48. With the increase of jet spacing, the circumfluence zone of Oxz axis is shifted downstream, and the region with oxygen mass fraction higher than 10% is gradually reduced, and the combustion peak value is decreased. When the jet spacing increases to 75mm, the range of Oxz axial reflux region is obviously reduced. The increase of oxygen volume fraction in the reaction zone increases the combustion peak. The peak value of combustion in coaxial jet mode is about 2200kg. only when the maximum temperature rise of furnace combustion is less than the ignition temperature of pulverized coal (790 K), the combustion of oxygen-coal MILD (moderate or intensive low oxygen dilution, can be realized when the jet spacing is 60mm.
【作者单位】： 同济大学机械与能源工程学院;
【基金】：上海市科委资助项目(13DZ2260900)
【分类号】：TK16
，
本文编号：2300401
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