Replacing natural gas with the environmentally sustainable biogas is a promising way to reduce the usage of fossil fuels and promote organic waste utilization. Micro gas turbine (MGT), as a common power supply machine, is capable of adopting biogas as the fuel. Given the different intrinsic components between natural gas and biogas, combustion performance of biogas in MGT was studied in this work. The effects of fuel composition and excess air coefficient on combustion performance were analyzed through three-dimensional numerical simulation of the MGT combustor. RNG k-ε turbulent model, eddy-dissipation/finite rate model, and eight-step reaction mechanism were adopted in the simulation. The results showed that when the CO₂ percentage in biogas increases, the NO and CO emissions decreases. However, the fuel rate and pressure drop of combustion chamber increases to maintain constant thermal input. The overall high velocity also increases the requirement for materials of combustion chamber. Furthermore, the average temperature of whole combustor decreases when the excess air coefficient increases. Accordingly, the CO₂ mole fraction in biogas should be controlled below 30% and the optimal range of the excess air coefficient is 2–2.5 for the MGT.

用环境可持续的沼气代替天然气是减少化石燃料使用和促进有机废物利用的有前途的方法。微型燃气轮机（MGT）作为一种常见的供电设备，可以采用沼气作为燃料。鉴于天然气和沼气的固有成分不同，本文研究了沼气在 MGT 中的燃烧性能。通过MGT燃烧室的三维数值模拟，分析了燃料成分和过量空气系数对燃烧性能的影响。仿真采用RNG k - ε湍流模型、涡耗散/有限速率模型和八步反应机理。结果表明，当 CO ₂沼气中的百分比增加，NO 和 CO 排放量减少。然而，燃烧室的燃料率和压降增加以保持恒定的热输入。整体的高速度也增加了对燃烧室材料的要求。此外，当过量空气系数增加时，整个燃烧室的平均温度降低。因此，沼气中的CO ₂摩尔分数应控制在30%以下，MGT的最佳过量空气系数范围为2-2.5。