当量比对微型燃气轮机H_(2)/Air燃烧特性的影响

Effect of Equivalence Ratio on H_(2)/Air Combustion Characteristics of Micro Gas Turbine

为了探究氢气微型燃气轮机的燃烧特性,用数值模拟方法分析了6种不同当量比工况下的燃烧室内流场特性、压力损失、燃烧效率、NO_(x)排放和速度分布等参数。结果表明:当量比对回流区的范围影响不大,压力损失和出口速度随当量比增加逐渐增大,出口温度分布系数(OTDF)、排气温度和NO_(x)排放随当量比的增加先增大后减小;径向速度的分布关于燃烧室中心轴线对称;当量比小于1时,燃烧效率在99.9%以上;当量比大于1时,燃烧效率随当量比增加而降低;当量比为1时,排气温度达到2 500 K,NO_(x)排放达到最大值,偏离化学当量比燃烧有利于抑制NO_(x)的生成。

In order to explore the combustion characteristics of hydrogen micro gas turbine, the parameters of flow field characteristics, pressure loss, combustion efficiency, NO_(x) emission and velocity distribution of combustion chamber at six different equivalence ratios were analyzed by numerical simulation method.The results show that the equivalence ratio has little effect on the range of recirculation zone, with the increase of equivalence ratio, the pressure loss and outlet velocity gradually increase, the outlet temperature distribution factor(OTDF), exhaust temperature and NO_(x) emission first increase and then decrease.The radial velocity distribution is symmetrical about the central axis of the combustion chamber.When the equivalence ratio is less than 1, the combustion efficiency is above 99.9%;when the equivalence ratio is greater than 1, the combustion efficiency decreases with the increase of equivalence ratio;when the equivalence ratio is 1, the exhaust temperature reaches 2 500 K,NO_(x) emission reaches the maximum, deviation from the stoichiometric combustion is beneficial to the inhibition of NO_(x) formation.