【摘要】：以Φ200 mm×2 m的火焰爐為對象,借助軟件FLUENT研究了在O_2/CO_2氣氛下燃燒器射流動量比和射流間距的改變對爐內(nèi)流場特性和燃燒特性的影響.結(jié)果表明:當射流動量比由28增至66時,煙氣內(nèi)循環(huán)率峰值呈現(xiàn)先增大后減小的趨勢,混合區(qū)煙氣內(nèi)循環(huán)率的整體水平是在射流動量比為48時最大;隨著射流間距的增大,Oxz軸面回流區(qū)向下游偏移,且氧氣質(zhì)量分數(shù)高于10%的區(qū)域逐漸縮小,燃燒峰值有所降低,當射流間距增至75mm時,Oxz軸面回流區(qū)的范圍明顯縮小,反應(yīng)區(qū)氧氣體積分數(shù)回升,使得燃燒峰值升高.同軸射流方式下的燃燒峰值最高,約2 200K,僅當射流間距為60mm工況下的爐膛燃燒最大溫升小于煤粉的著火溫度(790 K),即可實現(xiàn)氧煤MILD(moderate or intensive low oxygen dilution,溫和)燃燒.
[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.
【作者單位】： 同濟大學(xué)機械與能源工程學(xué)院;
【基金】：上海市科委資助項目(13DZ2260900)
【分類號】：TK16
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本文編號：2300401