Numerical study of oxy-fuel MILD (moderate or intense low-oxygen dilution combustion) combustion for CH4–H2 fuel
Numerical study of oxy-fuel MILD (moderate or intense low-oxygen dilution combustion) combustion for CH4–H2 fuel
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DOI：
10.1016/j.energy.2016.01.016
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发表时间：
2016-03
期刊：
影响因子：
9
通讯作者：
A. Mardani;A. Ghomshi
中科院分区：
文献类型：
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作者：
A. Mardani;A. Ghomshi
本文对富氧燃烧与温和或强烈低氧稀释燃烧（MILD）的组合燃烧（OXY-MILD）进行了数值研究。采用CO2和H2O代替热氧化剂中的N2，进行了温和燃烧试验.该研究采用CFD分析、零维搅拌反应器分析和反应器网络分析进行。在计算流体力学分析中，针对二维轴对称计算域求解了RANS方程和修正的k− ε方程。结果表明，在温度梯度，反应速率，和Damköhler数的OXY-MILD条件下相比，温和的。预热氧化器中的氧含量越高，从热氧化器中去除N2对反应区的均匀性和延伸越有效。在OXY-MILD条件下，随着入口氧气浓度的增加，反应区中CO、NO、CH 2 O和HCO的浓度降低，温度升高。此外，燃料氢含量对反应区的影响进行了研究。燃料氢含量的减少导致OXY-MILD燃烧温度场的均匀性和反应区面积的增加，NO和CO的生成量减少。
This paper demonstrates a numerical study on the combination of Oxy-Fuel and MILD (moderate or intense low-oxygen dilution combustion) combustions, ie OXY-MILD. The N 2 of a hot oxidizer was replaced with CO 2 and H 2 O in a MILD combustion test case. The study was conducted using a CFD analysis, a zero-dimensional well-stirred reactor analysis, and a reactors network analysis. In the CFD analysis, RANS equations with modified k− ε equations were solved for a 2D-axisymmetric computational domain. Results showed a decrease in temperature gradient, reaction rate, and Damköhler number under the OXY-MILD condition in comparison with the MILD one. It seems the higher the oxygen level in the preheated oxidizer, the more effective the removal of N 2 from the hot oxidizer was on the uniformity and extending of the reaction zone. Under OXY-MILD condition, an increment of inlet oxygen level decreased concentrations of CO, NO, CH 2 O, and HCO and increased temperature in the reaction zone. Furthermore, the effect of fuel hydrogen content on the reaction zone was investigated. A reduction of fuel hydrogen content led to an increase in both the uniformity of temperature field and the area of the reaction zone, and a decrease in formations of NO and CO for the OXY-MILD combustion.