生物质气、合成气等含氢燃气是燃气轮机的重要替代燃料，由于其热值及燃烧特性与天然气差异较大，如何实现它们在干式低NOx燃气轮机中的稳定燃烧是一个挑战；而分层燃烧模式下如果浓混气火焰向稀混气传播，则能扩大可燃界限，提高燃烧稳定性。本项目以含氢燃气的分层燃烧为研究对象，利用PIV、PLIF等多种测量方法对受限的带有双旋流入流通道的新型可视化分层燃烧装置开展一系列的燃烧实验，确定不同含氢量不同热值的燃气在各种条件下的燃烧稳定性；同时利用两种亚网格燃烧模型对测量的火焰开展系统性的大涡模拟计算。在可靠校核模型性能的基础上，对比分析计算结果与实验数据，深入研究受限空间内旋转湍流与分层火焰相互作用的内在机理，掌握各种燃烧状态参数对燃烧稳定性的影响规律，充分了解分层燃烧模式下含氢中、低热值燃气与天然气燃烧特性的异同，为设计既可燃烧天然气又可燃烧含氢中、低热值燃气的干式低NOx燃气轮机燃烧室提供理论指导。

Hydrogen containing fuel gases with medium and low heat value (MLHV), such as biomass gas and syngas (heat value is around 5-20MJ/Nm3), are important alternative fuels for industry gas turbines. However, how to combust them stably in the dry low NOx (DLN) gas turbine is still an open challenge because of their lower heat values and much different combustion characteristics compared with nature gas. In stratified combustion mode, if the richer branch premixed flame (equivalence ratio smaller than unit) propagate towards lower equivalence ratios, an enhanced flame propagation and extended flammability limit can be achieved and therefore combustion stability is improved. This stratified combustion concept provides a feasible means of burning hydrogen containing fuel gases with MLHV stably. In the present project, a series of experimental studies on a novel visual turbulent combustor, with a confinement and a double-swirling-flow passage (manufactured by advanced 3D printing technology), are conducted to determine the combustion stability of fuel gases with different levels of hydrogen content and heat value in various conditions. For doing so, several measurement apparatuses are employed, including PIV (particle image velocimetry) and PLIF (planar laser induced fluorescence) methods. At the same time, large eddy simulations (LES) of the measured flames are performed systematically by using two different sub-grid scale combustion models. After a reliable validating of the accuracy of the used combustion models, detailed experimental data and highly accurate LES results are analyzed together for obtaining a deep insight of the interaction mechanism between turbulent swirling flow and stratified flame, for grasping the influencing law of various combustion state parameters on combustion stability, and for gaining a better understanding of the similarities and differences between the combustions of nature gas and hydrogen containing fuel gases with MLHV. The present project can hence provide a theoretical guidance in design uniform DLN gas turbine combustor, which is suitable for burning either nature gas or hydrogen containing fuel gases with MLHV.