Experimental study on telemetry of hydrogen leakage based on Raman spectroscopy

Hydrogen possesses vast potential for development and application. However, its low density and high diffusion coefficient render it prone to leakage during storage and transportation. It is necessary to conduct a safe and effective high sensitivity real-time leak detection for hydrogen. In this study, a telemetry system for hydrogen leakage based on Raman spectroscopy was built, simulating the scene of hydrogen leakage from the pipeline to the atmosphere through the air knife, and the actual concentration of hydrogen leakage into the air was measured directly. Based on the method of theoretical analysis and numerical simulation, the time-domain variation characteristics and influencing factors of the measured Raman scattering signal are analyzed, and the leakage concentration measured by the system is simulated and verified. The results show that the system has good measurement effectiveness. In the concentration range below the hydrogen explosion limit, the hydrogen leakage was measured at different leakage conditions with distance 1–5 m and leakage flow 0.25–3 L/min. The results show that the lower limit of concentration measurement of the system is 0.07 vol%. When the hydrogen concentration before leakage is the hydrogen explosion limit of 4.0 vol%, the minimum measurable leakage flow is 0.5 L/min, and the farthest measurement distance is 5 m. This study provides an intuitive and powerful reference for the engineering application of long-range portable measurement of hydrogen leakage based on Raman scattering spectroscopy.