Experimental and numerical simulation study of hydrogen explosion suppression by a small amount of ethylene

Abstract

Hydrogen safety is the foundation of hydrogen energy industry, but there is presently a shortage of high-efficiency safety protection technologies for hydrogen. Through a combination of experiment and simulation methods, this paper reveals the effective performance of ethylene in suppressing the hydrogen explosion behaviors in a 14 L closed spherical vessel at normal temperature and pressure. The experimental and simulation results show that a small amount of ethylene can increase the hydrogen generation path in the lean hydrogen chain reaction, thus enhancing the concentration of active free radicals and causing flame instability, which ultimately leads to an increase in explosion overpressure and laminar burning velocity. But on the whole, with the increase in ethylene volume fraction, the explosion parameters show a monotonically decreasing trend. This is because the addition of ethylene makes the hydrogen-oxygen chain reaction gradually transition to the inactive free radical chain reaction, resulting in the conversion of the active free radical to the inactive free radical, and the chain reaction rate is weakened. Finally, the explosion cannot occur. This result provides a novel idea for the research of new and efficient hydrogen explosion suppression materials.