将风电、光伏发电的富余电力制氢气，并与天然气掺混制得掺氢天然气（HCNG）供用户使用，既可解决电力“弃风弃光”问题，也有助于燃烧设备的清洁燃烧。同时掺氢天然气由两种最为简单常见但又燃烧性能迥异的小分子燃料混合而成，对其燃烧特性研究具有重要应用价值和理论意义。掺氢天然气的可燃极限直接关系到其输送、存储和使用安全，但已有的研究比较缺乏，且实验数据准确性不足，相关机理研究不充分。本项目通过微重力实验和对冲火焰法等实验方法，获得宽掺氢比、不同压力下掺氢天然气可燃极限的准确实验数据系列和变化规律，同时通过数值模拟、理论分析等方法研究掺氢天然气近极限燃烧过程的化学动力学特性和多元分子扩散规律，揭示常压和加压条件下掺氢引发的优势扩散效应和Soret效应对熄灭极限及可燃极限的影响规律，并与单组分气体火焰和掺氢天然气强火焰进行对比，为掺氢天然气的工业应用提供理论基础。

Hydrogen compressed natural gas (HCNG) is a mixture of natural gas and hydrogen that is normally produced using the excess wind and solar power. The utilization of HCNG is of practical significance as it is not only capable of digesting the excess wind and solar power but also conductive to achieving a clean combustion in combustion devices. Moreover, the study on the combustion characteristics of HCNG is of theoretical interest as hydrogen and natural gas, the two components in HCNG, are both simple and commonly seen but remarkably distinct in nature. The flammability limit of HCNG is directly related to the safe transportation, storage and utilization of HCNG. However, relevant studies are not sufficient and the accuracy of the existing experimental data does not meet the current requirement. Especially, there still lacks the in-depth understanding of the controlling mechanism of the near-limit HCNG combustion. In this project systematic experimental studies, employing advanced techniques such as the experimentation under the micro-gravity condition and the counterflow flame methodology, will be conducted to obtain accurate experimental data series and variation rules of HCNG flammability limit at various pressures over a broad range of hydrogen blending ratio. Numerical simulation and theoretical analysis will also be carried out to study the chemical kinetic characteristics and multi-species diffusion mechanisms of near-limit HCNG flames. In particular, the effects of preferential diffusion and Soret diffusion on the extinction and flammability limit of HCNG will be insightfully revealed. The results will be compared with those obtained from the studies on single-species gaseous fuels or strongly propagating HCNG flames. The conclusion of this study will establish a solid theoretical basis and shed light on the utilization of HCNG.