Enabling Advanced Modeling and Simulations for Fuel-Flexible Combustors

Heinz Pitsch

关键词: BURNERS;    COMBUSTION;    COMBUSTORS;    DATA;    DESIGN;    FLAME PROPAGATION;    FLAMES;    FORECASTING;    HYDROGEN;    INCLUSIONS;    LEWIS NUMBER;    OPTIMIZATION;    SIMULATION;    THERMAL DIFFUSION;    TRANSFORMATIONS;    TURBINES;   

DOI  :  10.2172/1001422
RP-ID  :  None
PID  :  OSTI ID: 1001422
Others  :  TRN: US201104%%88

学科分类：再生能源与代替技术

美国|英语

来源: SciTech Connect

【 摘 要 】

The overall goal of the present project is to enable advanced modeling and simulations for the design and optimization of fuel-flexible turbine combustors. For this purpose we use a high-fidelity, extensively-tested large-eddy simulation (LES) code and state-of-the-art models for premixed/partially-premixed turbulent combustion developed in the PI's group. In the frame of the present project, these techniques are applied, assessed, and improved for hydrogen enriched premixed and partially premixed gas-turbine combustion. Our innovative approaches include a completely consistent description of flame propagation, a coupled progress variable/level set method to resolve the detailed flame structure, and incorporation of thermal-diffusion (non-unity Lewis number) effects. In addition, we have developed a general flamelet-type transformation holding in the limits of both non-premixed and premixed burning. As a result, a model for partially premixed combustion has been derived. The coupled progress variable/level method and the general flamelet tranformation were validated by LES of a lean-premixed low-swirl burner that has been studied experimentally at Lawrence Berkeley National Laboratory. The model is extended to include the non-unity Lewis number effects, which play a critical role in fuel-flexible combustor with high hydrogen content fuel. More specifically, a two-scalar model for lean hydrogen and hydrogen-enriched combustion is developed and validated against experimental and direct numerical simulation (DNS) data. Results are presented to emphasize the importance of non-unity Lewis number effects in the lean-premixed low-swirl burner of interest in this project. The proposed model gives improved results, which shows that the inclusion of the non-unity Lewis number effects is essential for accurate prediction of the lean-premixed low-swirl flame.