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针对燃气轮机环管型双燃料燃烧室分别燃用庚烷和裂解气燃料的情况,采用CFD(computa-tional fluid dynamics)技术对其燃烧流场进行对比研究.数值模拟采用了RNGk-ε湍流模型、化学平衡条件下的快速化学反应系统和简单概率密度函数(PDF)燃烧模型、液体燃料的喷雾模型以及SIMPLE算法.模拟对比分析了两种燃料燃烧下的温度分布、燃烧效率、流量分配、壁面冷却效果、空气过量系数等参数,以及它们随工况变化的趋势.所得结论如下:①不同燃料燃烧时,流场内的流量分配基本保持一致;②裂解气燃料燃烧时,其燃烧效率高出燃油状态约1%,但出口温度均匀性较差;③在加入相同化学焓值的燃料进入燃烧室时,裂解气燃料的头部空气过量系数α较大,所得到的出口平均温度低于燃油状态约20~40 K.
Aiming at the problems of combustor combustion of heptane gas and pyrolysis gas in gas turbine dual-fuel toroidal tube, the computational fluid dynamics (CFD) technique was used to compare the combustion flow field.Numerical simulation using RNGk-ε turbulence model, Fast Chemical Reaction System and Simple Probability Density Function (PDF) Combustion Model, Liquid Fuel Spray Model and SIMPLE Algorithm Under Chemical Equilibrium Conditions The temperature distribution, the combustion efficiency, the flow distribution, the wall cooling Effect and air excess coefficient, as well as their tendency to change with the working conditions.The conclusions are as follows: (1) When different fuels are burned, the flow distribution in the flow field is basically the same; (2) When the pyrolysis gas is burned, its combustion efficiency is higher than that of the fuel And the outlet temperature uniformity is poor. ③ When the fuel with the same chemical enthalpy enters the combustion chamber, the air excess coefficient α of the cracked gas fuel is larger and the average outlet temperature obtained is lower than the fuel state About 20 ~ 40 K.