Performance Analysis of Ammonia-Doped Combustion in Micro Gas Turbine Combustion Chamber

ObjectivesAiming at the problem of high carbon emission of micro gas turbine in distributed energy, this study investigates the combustion characteristics of a 10 kW micro gas turbine combustion chamber under ammonia-blended conditions.MethodsCFD simulations coupled with the detailed Okafor mechanism are conducted to analyze the effects of varying ammonia blending ratios and global equivalence ratios on combustion efficiency, NO and CO emissions.ResultsAs the ammonia ratio increases from 0 to 1.0, the fluid velocity in the combustion chamber outlet increases from 62.27 m/s to 63.69 m/s, and the total pressure recovery coefficient decreases from 97.81% to 97.18%. Additionally, CO mass fraction significantly decreases to near 0, while the NO mass fraction increases from 1.16×10-4 to 3.68×10-4, indicating that ammonia reduces CO emissions but increases NO formation. Combustion efficiency slightly declines from 98.14% to 97.64%. The equivalence ratio has a notable impact on performance and emissions, with lower NO emissions at low equivalence ratios, NO emissions peaking at an equivalence ratio of 1.0, and decreasing under fuel-rich conditions, though combustion efficiency also declines.ConclusionsThe application of methane/ammonia mixtures requires a balance 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.