Effects of pentafluoroethane content, vent diameter, and static activation overpressure on hydrogen explosion equilibrium venting

To address the challenge that solely explosion venting cannot achieve hydrogen explosion equilibrium venting under limited venting parameters, this work experimentally determines the effectiveness of trifluoromethane and pentafluoroethane to inhibit hydrogen explosion venting. The effects of equivalence ratio, vent diameter, static activation overpressure, and inhibitor content on the maximum reduced explosion overpressure, maximum rate of pressure rise, and maximum external explosion overpressure are investigated. The critical content of equilibrium venting of pentafluoroethane is determined. Methods to experimentally and predictively obtain the dynamic action overpressure are provided. Based on the (dP/dt)stat-Pdyn function, a prediction method for the critical content of equilibrium venting is developed. The results show that pentafluoroethane improves the efficiency of explosion venting and achieves equilibrium venting under limited venting conditions. The critical content of equilibrium venting decreases with increasing vent diameter but is not sensitive to changes in static activation overpressure. The (dP/dt)stat-Pdyn function, which depends only on vent diameter and static activation overpressure, can predict the critical content of equilibrium venting at a given static activation overpressure using confined explosion inhibition data (absolute error <1 vol%). The prediction method offers a new perspective for equilibrium venting design involving explosion inhibition.