The effect of vacuum pressure on the flammability limits of hydrogen (H2) enriched liquefied petroleum gas (LPG) in a closed vessel

An experimental study on pressure explosion in 20-L closed vessel explosion unit of LPG–air –hydrogen mixtures was performed, for systems with various pressures evacuated. The objective of this research is to determine the correlation of vacuum pressure toward flammability limits of LPG H2 enriched. The explosion pressures and explosion times were measured in a 20-L closed vessel, at ambient initial temperature. The influence of initial pressure, initial temperature and fuel concentration on explosion pressures and explosion times are discussed. The explosion pressure data is use to determine the flammability limits of hydrogen enriched LPG. From the result, there are fairly same in flammability limits of LPG but there are quiet different in maximum pressure explosion which is increasing the pressure can be decrease the value of pressure explosion. Increasing vacuum pressure from 0.02 bar up to 0.04 bar slightly increase the upper flammability limit from 8.2 % to 8.3 % volume of liquefied petroleum gas by volume and also decrease the maximum pressure explosion which is from 5.8 bar to 5.7 bar.