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 °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 °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 °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.

Keywords

• Low-temperature
• Maximum explosion pressure
• Maximum rate of pressure rise
• Methane