作为微热光电系统的关键部件,燃烧室的性能对整个系统的输出功率具有决定性影响。采用数值模拟与实验验证相结合的方法,研究了微燃烧器结构(回热管有/无肋片、火孔间距S/D)对可燃极限、流场分布、传热效应、污染物排放的影响。结果表明,相比于无肋片设计,有肋片的燃烧器的火焰根部锚定能力更强,脱火极限拓宽;预热效应更强,外壁面温度更高,辐射效率更大。S/D对火焰根部的锚定有重要影响,S/D=1.1时,火焰根部分别锚定在多孔板的中心和角再循环区(IRZ和CRZ);S/D=1.3时,火焰由IRZ和壁面边界层锚定;S/D=1.5时,火焰由中心低速区和壁面边界层锚定。综合来说,有肋片且S/D=1.1为最佳结构设计,虽然它的热性能、辐射效率和燃烧效率次优,介于S/D=1.3和1.5之间,但展现了最佳预热率和火焰稳定性,最宽的稳燃范围,且燃烧器出口CO排放最低。该研究可为微热光电系统高性能燃烧室的优化设计提供了重要的理论依据和实践指导。
As a key component of micro-thermophotovoltaic systems, the performance of burners decisively influences the overall system output power. However, at micro/meso scales, combustion systems are plagued by inherent limitations including short residence times and substantial heat loss. Although numerous literatures have proposed various burners to enhance combustion performance, their combustion efficiency and radiation efficiency remain low. To address these issues, this work proposes a perforated plate burner with finned recuperator. This study employs a combined approach of numerical simulation and experimental validation to investigate the effects of burner structures [with/without finned recuperator and distance between the fire holes (S/D)] on flammability limits, flow field distribution, heat transfer effects, and pollutant emissions. Key findings reveal that compared to non-fins designs, the fins burners exhibit better flame root anchoring capability and a broader flammability limit. And they also achieve stronger preheating effects, higher outer wall temperatures, and greater radiant efficiency. It is worth noting that the parameter S/D plays a crucial role in flame anchoring mechanisms. To be specific, at S/D=1.1, the flame is anchored by both the inner and corner recirculation zones (IRZ and CRZ). At S/D=1.3, the flame stabilization is dominated by the IRZ and the wall boundary layer. While at S/D=1.5, the flame is anchored by the central low-velocity zone and the wall boundary layer. Through in-depth analysis, it is demonstrated that the design with fins and S/D=1.1 represents the optimal structural configuration. Although, its combustion efficiency and radiation efficiency fall between those achieved at S/D=1.3 and 1.5, it exhibits the best preheating rate and flame stability, along with the widest stable combustion range and produces the lowest CO emissions at the burner outlet. This research provides valuable insights into flame stabilization mechanisms and offers practical guidance for designing high-performance miniature power devices.