Critical Explosible Oxygen Concentration of Methanol-Saturated Vapor/O₂/N₂ Mixtures at Elevated Temperatures and Pressures

Abstract

The critical oxygen concentration (COC) in this study is defined as the maximum oxygen concentration at which a mixture of methanol vapor in nitrogen does not explode, regardless of the nitrogen concentration in the mixture. This paper presents data on the critical oxygen concentration (COC), in the presence of added N2, of methanol (CH4O) saturated vapor mixtures at elevated temperature and pressure. We have used a COC measurement system consisting of a 4-L explosion vessel, an ignition subsystem, and a transient pressure measurement subsystem. Through a series of experiments carried out in this system, the COCs of methanol-saturated vapor/O2/N2 mixtures at different initial pressures and an elevated temperature of 80 °C have been studied, and the influence of concentration of nitrogen on the COC has been analyzed and discussed. Variation of the initial pressure within the studied range was found to have significant effect on the COCs of the methanol saturated vapor/O2/N2 mixtures. There is a very large difference between the COCs (or CNCs) of the methanol-saturated vapor/O2/N2 mixtures at the elevated temperature and pressure and those of methanol vapor in air at atmospheric pressure and room temperature. The COCs of the methanol-saturated vapor/O2/N2 mixtures with the initial temperature of 80 °C at the initial pressure of 0.5, 0.4, and 0.3 MPa are 36, 28, and 21 vol %, respectively. The corresponding CNCs at initial pressures of 0.5, 0.4, and 0.3 MPa are 54, 59.5, and 62 vol %, respectively.

A Comparative Study of the Explosion Characteristics of IPN and IPN/JP‐10 Mixtures in Air Aerosols

“…Based on previous studies [35][36][37][38][39][40][41][42][43][44], we synchronized the trends in the peak explosion pressures and the peak explosion temperatures of the pure gaseous fuel/air mixtures. However, Figure 3 shows that the concentration that produced the maximum peak pressure of the IPN/air aerosols with a mean SMD of~34 mm was greater than the concentration that produced the maximum peak temperature.…”

Influence of Vapor–Liquid Two-Phase n-Hexane/Air Mixtures on Flammability Limit and Minimum Ignition Energy

“…The electrode diameter used in the experiments was 5 mm. The device of spark ignition energy can be found in previous references. − In three transparent windows, the Mie extinction detection system was placed at the positions 1/5, 1/2, and 4/5 of the vessel. The double-nozzle pneumatic atomization system, the optical particle size and concentration detection system, and the electric ignition system were controlled by a central control system and set to different trigger times in each experiment.…”

Influence of Vapor-Liquid Two-Phasen-Heptane on the Explosion Parameters in Air

“…Namely, the peak temperature decreases with the increase of the SMD. Moreover, from the previous references (Liu et al, 2014a;Zhang et al, 2011bZhang et al, , 2014, the trends in the peak explosion pressures and the peak explosion temperature of pure gaseous fuel/air mixtures have the characteristics of synchronicity. From Figures 3 and 4 contrast to be seen, the concentration of the maximum peak pressure is greater than the concentration of the maximum peak temperature.…”

“…The electrode diameter used in the experiments was 5 mm. The device of spark ignition energy can be found in previous references Liu et al, 2014aLiu et al, , 2014bZhang et al, 2011aZhang et al, , 2014). The measurement of particle size distribution and concentration based on MIE extinction, the method of using multi-wavelength light extinction is proposed in this work (Liu et al, 2014c;Ma and Hanson, 2005;Sun et al, 2007).…”

“…By means of a traditional igniting test, one can easily determine the ignition energy based on the given capacitance and applied voltage through simple calculation (Liu et al, 2014a;Zhang et al, 2014). The traditional test, referred to as the simple method, follows the general relationship:…”