Hydrogen, recognized as a clean and efficient renewable energy source, plays a significant role in China's 'double carbon' goal. The use of hydrogen-doped natural gas as a clean fuel is bound to be promoted. However, the addition of hydrogen increases the risk of gas leakage and explosion, and its safety will become a key bottleneck in the process of promoting the use of hydrogen-doped natural gas. This paper provides a detailed analysis of the current state and progress in research on the combustion and explosion characteristics of hydrogen-doped natural gas conducted by scholars globally. It is found that the current research mainly focuses on the pre-mixed flame propagation characteristics, combustion characteristics, and explosion characteristics of the three aspects. Then, it is pointed out that there are two problems in the current research: first, the lack of revelation regarding the kinetic mechanism of the accelerated reaction of hydrogen-doped natural gas flaring flame; second, the absence of a systematic study on the flaring characteristics of hydrogen-doped natural gas in large-scale confined spaces. Finally, it is proposed that, considering the unclear flame acceleration mechanism of hydrogen-doped natural gas combustion explosions in large-scale confined spaces, along with complex propagation laws and other challenging issues, future research should focus on unveiling the dynamics of flame acceleration and propagation reactions. This involves determining the spatial and temporal evolution of hydrogen-doped natural gas combustion explosions in large-scale confined spaces under the conditions of multi-factor coupling. Such research aims to provide a solid theoretical basis and technical support for preventing and controlling safety accidents, ensuring a reliable foundation for the promotion and use of hydrogen-doped natural gas.

hydrogen-doped natural gas,renewable energy source,combustion and explosion,propagation laws