Experimental and theoretical study on the suppression effect of water mist containing dimethyl methylphosphonate (DMMP) on hydrogen jet flame

This work investigates the suppression effect of water mist containing dimethyl methylphosphonate (DMMP) on H2 jet flame. The flame appearances are analyzed and the flame temperature is recorded by a high-speed infrared camera. Results show that the suppression effect of water mist containing DMMP is better than that of pure water mist. To better understand the suppression effect of water mist containing DMMP, the burning velocity, heat production and free radicals are analyzed. Results indicate that suppressant could scavenge lots of free radicals to reduce the burning velocity in a wide range of equivalence ratios. Moreover, the influence of DMMP on lean CH4 and H2 flames is compared. Different with that of lean CH4 flame, the combustion parameters of lean H2 flame decline with DMMP addition. There is no combustion enhancement effect of DMMP on lean H2 flame. Because of the higher combustion intensity of lean H2 flame, the hydrocarbon in DMMP has little impact on the combustion. Furthermore, the reaction path of DMMP decomposition is analyzed. Results demonstrate that the rates of most phosphorus reactions in H2 flame are larger than that in CH4 flame. This work could provide foundation for improving the safety of hydrogen energy application.