Abstract: [Objective] To investigate the combustion characteristics of a micro gas turbine combustion chamber under ammonia-blended conditions. [Methods] CFD simulations were conducted to analyze the effects of varying ammonia blending ratios and global equivalence ratios on combustion efficiency, NO, and CO emissions. [Results] The results showed that as the ammonia ratio increased from [基金项目：国家自然科学面上项目(51976139)。 Project Supported by General Program of the National Natural Science Foundation of China (51976139).]0 to 1, the fluid velocity in the combustion chamber increased from 62.27 m/s to 63.69 m/s, and total pressure loss rose from 2.19% to 2.82%. Additionally, NO emissions increased from 116 ppm to 368 ppm, while CO emissions significantly decreased to near 0 ppm, indicating that ammonia reduced CO emissions but increased NOx formation. Combustion efficiency slightly declined from 98.14% to 97.64%. The global equivalence ratio had a notable impact on performance and emissions, with NO emissions peaking at an equivalence ratio of 1, and decreasing under fuel-rich conditions, though combustion efficiency also declined. [Conclusion] It is concluded that methane/ammonia mixtures require balancing among total pressure recovery coefficient, NO and CO emissions, and combustion efficiency. Further design optimization is needed to achieve efficient and low-emission combustion performance.

Key words: micro gas turbine, methane/ammonia mixture fuel, combustion characteristics, pollutant emissions, numerical simulation