The effect of low temperature on the explosion characteristics of a methane/air mixtures

Abstract

Prevention and mitigation of unwanted explosions require knowledge of explosion characteristics. Available explosion data are not always adequate for use in a particular application. For example, predicting the behavior of gas explosions at a lower temperature should be based on the explosion data obtained at these temperatures and not atmospheric. Basic knowledge of the methane explosions at low temperatures is desirable for a thorough understanding of this gas that cannot be found in the literature. In the presented research, the methane/air deflagrations were studied in the millisecond time domain. The standard 20-L deflagration chamber was adopted to produce consistent and reproducible data for the comparison of atmospheric and low initial temperature measurements. Methane/air mixtures were studied experimentally for concentrations between 4.6 vol.% and 16.6 vol.% and two initial temperatures of 20 and -5 degrees C. More than three hundred and fifty pressure-time curves were recorded and analyzed. Twenty-five deflagration curves of the methane/air mixtures were studied in 20-L volume for the first time, including thirteen pressure-time curves at -5 degrees C. The effects of temperature on the maximum rate of pressure rise and deflagration index were investigated. The evaluated experiments' results are the maximum pressure rise rate of 261 bar/s at -5 degrees C. This work allowed potential hazards involving the handling and storing of fuels. Many pieces of knowledge must be collected to advance the phenomenological understanding of low-temperature deflagrations to make realistic theoretical predictions and correlations.