环管型燃烧室横截面积变化对燃烧及NO_x生成的影响

Influence of cross-sectional area on combustion and NO_x formation in can-annular combustion chamber

采用数值模拟方法研究了环管型燃烧室横截面积变化对燃烧室燃烧、流动及燃烧室NO_x生成及排放的影响规律。分析表明:在环管型燃烧室主喷嘴出口形成主回流区,凸台区域形成外部回流区,外部回流区范围较小;随着横截面积增大,主回流区范围增大,温度峰值和高温区范围均有所减小;增大横截面积使得比面积热强度随之减小,燃烧室内温度水平逐渐下降,热力型NO_x生成速率降低,燃烧室出口NO_x排放量下降。

Effects of the change of the cross-sectional area of the can-annular combustion chamber on the combustion,flow,NOx formation and NOx emission in the combustion chamber are studied by numerical simulation.The results show that,the main recirculation zone is formed at the outlet of the main nozzle of the can-annular combustion chamber,the outer recirculation zone is formed in the boss area,and the range of outer recirculation zone is small.As the cross-sectional area increases,the range of the main recirculation zone increases and the temperature peak and high-temperature zones decrease.Increasing the cross-sectional area reduces the specific area heat intensity,the temperature level of the combustion chamber,the thermal NOx formation rate and the NOx emissions from the combustion chamber.