Analysis of safety prevention and control techniques for hydrogen leakage in hydrogen-powered rail vehicles

The safety of hydrogen-related systems in hydrogen-powered rail vehicles is the core concern for rail transit utilizing new energy sources. Applying an inductive analytical approach, this paper systematically reviews the current status of development in hydrogen-powered rail vehicles and the research progress on on-board hydrogen leakage and safety prevention and control in China and abroad. It analyzes the common failure modes, causes, and process mechanisms of hydrogen leakage in exiting hydrogen-related systems of rail vehicles, and describes the diffusion characteristics of hydrogen leakage in rail transit systems. The paper also delves into key technology research, prevention and control in typical scenarios, the formulation of standards and specifications, and the establishment of active and passive safety systems. These analyses show that preventing hydrogen leakage and fire/explosion in complex railway scenarios such as electrified sections, tunnels, stations, hydrogen refueling stations, and depots remain a major challenge for the future. Continuously developing on-board safe hydrogen storage and utilization techniques for rail vehicles, strengthening monitoring, maintenance, and emergency response mechanisms, and establishing a hydrogen safety prevention and control technology system for railways are identified keys to ensuring the safety of hydrogen-powered rail vehicles and accelerating the development of hydrogen-based rail transit.