湍流燃烧模型在燃气轮机燃烧室模拟中的运用与对比

Application and Contrast of Turbulent-flow Combustion Models for Simulating a Gas Turbine Combustor

利用Fluent商业软件,对燃气轮机燃烧室C16H29非预混燃烧流场进行数值模拟。针对燃烧室的额定工况,分别采用简单概率密度函数模型、涡耗散模型、涡耗散概念模型的2步反应和5步反应过程,对湍流燃烧流场进行对比数值分析,同时,考察燃烧室Thermal和Prompt NOx排放性能。通过比较发现,有吸热反应过程的EDC-5步模型所得流域内燃烧区温度较低;出口温度均匀性最好,最大不均匀度28%;NOx排放量最少。结果表明,该模型能够更合理地预测燃烧室的流场分布。

By using commercial software Fluent,numerically simulated was the C16H29 non-premixed combustion flow field of a gas turbine combustor. At the rated operating condition of the combustor,a contrast numerical analysis was conducted of the above flow field by adopting the two-step reaction process and five-step one of a simple probability density function (PDF) model,eddy dissipation (ED) model and eddy dissipation concept (EDC) model respectively. In the meantime,the Thermal and Prompt NOx emission performance of the combustor was also investigated. Through a comparison,it has been found that the temperature in the combustion zone resulting from an endothermic reaction process of the EDC-five-step model,is relatively low and the outlet temperature uniformity is optimal with its maximum non-uniformity being assessed at 28%. As a result,the NOx emissions have been minimized. The research results show that the model in question can more rationally predict the flow field distribution of the combustor.