Minimum ignition energy for the CH^sub 4^/CO^sub 2^/O^sub 2^ system at low initial temperature

• Published in: Fuel (Guildford) 2018-12, Vol.233, p.159
• Main Authors: Cui, Gan, Wang, Shun, Bi, Zhenxiao, Li, Zili
• Format: Article
• Language: English
• Subjects: Atmosphere; Carbon dioxide; Conductivity; Energy; Equivalence ratio; Ignition; Initial pressure; Methane; Pressure; Temperature; Temperature effects; Theoretical analysis
• ISSN: 0016-2361; 1873-7153

In this paper, the minimum ignition energy (MIE) for methane in an atmosphere of CO2/O2 is measured at 0.1–0.7 MPa and 183–273 K using a gas explosion experimental device that is able to withstand a temperature as low as 113 K. Effects of initial temperature (T0) and initial pressure (P0) on MIE are studied via experiment and a simple theoretical analysis. Results indicate that in our experimental setup, the sensitive conditions of MIE are an equivalence ratio of 1 and an electrode gap of 1 mm. Under low initial temperature, the trends in MIE with respect to initial pressure and temperature in an atmosphere of CO2/O2 are similar to those in an atmosphere of N2/O2. With an increase in initial pressure and temperature, MIE gradually decreases. MIE has a linear correlation with the reciprocal of the square of the initial pressure and the reciprocal of the initial temperature. At low initial temperature, P0 has a large impact on MIE, whereas at low initial pressure, MIE is more sensitive to initial temperature. At the same initial temperature and pressure, MIE in an atmosphere of CO2/O2 is about 1.2 times larger than that in an atmosphere of N2/O2 atmosphere. CO2 is more dilute than N2 in accordance with large heat capacities and small thermal conductivities.