Temperature and radical concentration are the two most important factors affecting NOx emissions in the methane combustion, while chemiluminescence is from the radiative transition of excited radicals, related to the heat release closely. Accordingly, there must be an implicit link between NOx formation and chemiluminescence. Chemiluminescence and NOx emission characteristics under various equivalent ratios ($\phi$) and swirl numbers (S) have been investigated in a lean premixed dual-swirl flame. The results show that $\phi$ and S have different effects on chemiluminescence intensities and flame structures, and the change trend of NOx emissions is the same as chemiluminescence intensities. More importantly, a linear relationship between chemiluminescence intensities and NOx emissions was proposed and tested, making it possible to monitor NOx emissions in combustion by the non-intrusive and cost-effective chemiluminescence technique.

温度和自由基浓度是影响甲烷燃烧中NOx排放的两个最重要的因素，而化学发光则来自受激自由基的辐射跃迁，与放热密切相关。因此，NOx 的形成和化学发光之间必定存在隐含的联系。不同当量比下的化学发光和NOx排放特性（$\phi$) 和旋流数 ( S ) 在贫预混双旋流火焰中进行了研究。结果表明$\phi$和S对化学发光强度和火焰结构的影响不同，NOx排放的变化趋势与化学发光强度相同。更重要的是，提出并测试了化学发光强度与 NOx 排放之间的线性关系，从而可以通过非侵入性且具有成本效益的化学发光技术监测燃烧中的 NOx 排放。