Determination of safety parameters of cryogenic species

Storage systems at cryogenic conditions are gaining significant attention as potential alternatives in sustainable energy systems, being characterized by lower carbon content and, thus, lower density at atmospheric conditions than traditional fuels. However, their combustion properties under near cryogenic conditions remain insufficiently characterized, particularly regarding laminar burning velocity (LBV), a key parameter for assessing flame propagation and safety risks. This thesis investigates the LBV of hydrogen, methane, ethylene, and propane at ambient pressure and low initial temperatures, combining experimental and numerical approaches. The experimental study conducted in this work was based on a Heat Flux Burner (HFB), modified to operate at low-temperatures, ensuring stable and repeatable LBV measurements. Additionally, Laser Doppler Anemometry (LDA) was employed to characterize the burner’s velocity profile, verifying its ability to sustain a plug flow condition, a crucial aspect for minimizing flow disturbances and ensuring measurement accuracy. On the numerical side, simulations were performed using detailed chemical kinetic models to analyse the effect of temperature reduction on LBV. The results indicate a nonlinear dependence of LBV on temperature, with reduced flame propagation speeds as temperature decreases, driven by both kinetic and diffusional effects. Hydrogen, in particular, exhibits a distinct behaviour compared to hydrocarbons, highlighting the necessity of dedicated safety measures in cryogenic fuel storage and transport. This study contributes to a better understanding of cryogenic flame dynamics, helping to improve safety assessments and combustion modelling for fuels such as hydrogen and liquefied hydrocarbons. By integrating advanced experimental diagnostics with computational analysis, this research supports the safe and efficient implementation of cryogenic fuels in future industrial and energy applications.