Performance Numerical Simulation Of Gas Turbine Combustor Using Ammonia Fuel

Ammonia fuel has attracted much attention because of its advantages of convenient preparation and storage.The popularization of ammonia fuel in gas turbines can greatly reduce CO₂ emissions.However,due to the high ignition energy and slow flame propagation speed,ammonia fuel has some challenges in practical application.To realize the efficient utilization of ammonia fuel,it is necessary to deeply understand the chemical reaction kinetic characteristics of ammonia fuel and the influence of typical geometric/physical parameters on the combustion characteristics of ammonia fuel.To solve this problem,this paper analyzes the characteristics of ammonia fuel premix and diffusion flame,and obtains the combustion organization method of ammonia fuel premix and diffusion flame.The main research contents of this paper are as follows:（1）The reaction kinetics characteristics of ammonia fuel were studied.The ignition delay time and laminar flame velocity under different fuel components were studied in a closed homogeneous reactor and a laminar premixed flame reactor.The results show that the ignition delay time is reduced by 1～2ms and the laminar flame velocity is increased by about 4cm/s when hydrogen mixture of 10%and 20%is compared with pure ammonia fuel.The laminar flame velocity of ammonia fuel is the highest near equivalent ratio 1.1.（2）A numerical study was carried out on the premix and diffusion flame characteristics of pure ammonia fuel/hydrogen mixture,focusing on the effects of equivalent ratio,pressure,swirl intensity,incoming flow velocity,hydrogen mixing ratio and other parameters on the velocity distribution,temperature distribution,component distribution and flame morphology,and the variation law of premix and diffusion flame morphology with typical parameters was given.The results show that with the increase of premixed gas inlet velocity,the distribution area of low-speed zone in combustion chamber decreases gradually,while the area of high-temperature zone in combustion chamber increases gradually.The high temperature zone appears in the head of the combustion chamber,and the area of the high temperature zone increases with the increase of hydrogen mixing ratio.The high temperature zone behind the main combustion hole expands along the radial direction of the flame cylinder and shorens along the axial direction.（3）Taking a countercurrent annular combustion chamber as the research object,the combustion organization method of ammonia fuel was studied,and the velocity field,temperature field,composition field and combustion chamber outlet performance parameters under typical working conditions were analyzed.The results show that the combustion efficiency of pure ammonia combustor is more than 97%,and with the increase of load,the combustion efficiency increases gradually,reaching 99.1%at 1.0 condition.Under the premise of ensuring the same outlet temperature,the combustion efficiency gradually increases to 99.9%with the increase of the proportion of ammonia fuel and hydrogen.