A safe and high-precision detection method for hydrogen leakage analysis of underground gas storage based on stimulated Raman spectroscopy of micro-nanofiber

Real-time monitoring technology for hydrogen leakage and diffusion is crucial for ensuring safety in large-scale geological hydrogen storage. Addressing challenges such as the easy diffusion and penetration of small molecular gases like hydrogen and the complexities of high-precision detection, a hydrogen leakage detection method is selected based on the stimulated Raman spectroscopy of micro-nanofibers for use in underground salt cavern hydrogen storage. A multi-point laser hydrogen sensing system was developed capable of high-precision real-time monitoring and analysis of minute hydrogen leaks. The system's hydrogen noise equivalent detection limit stands at approximately 122 ppm, with sensor sensitivity surpassing 200 ppm, enabling detection even at hydrogen concentrations as low as 0.1 %. The probe exhibits robust vibration resistance. Through both indoor and outdoor engineering application simulation tests, hydrogen leakage monitoring simulation for underground hydrogen storage was completed. These tests confirmed the feasibility and reliability of the system and validated an intrinsically safe hydrogen measurement scheme using optical fiber sensing integration. Furthermore, the system can measure hydrogen across its full concentration range with outstanding recovery and rapid second responses speed. It exhibits no zero drift and is selective, responding solely to hydrogen and not to other common interfering gases such as carbon monoxide. This selectivity helps reduce false alarms. With an expected service life exceeding 30 years for the photoelectric host, the system ensures the long-term safety and efficiency of underground hydrogen storage operations.