Laminar Flame Characteristics of Natural Gas and Dissociated Methanol Mixtures Diluted by Nitrogen

The effect of dissociated methanol (H2:CO = 2:1 by volume) on laminar burning velocity of natural gas (methane as the main component) was studied by using a constant volume bomb (CVB). Nitrogen, as diluent gas, was added into the natural gas (CH4) - dissociated methanol (DM) mixtures to investigate the dilution effect. Experiments were conducted at initial temperature of 343 K and initial pressure of 0.3 MPa with equivalence ratios from 0.8 to 1.4. Laminar burning velocities were calculated through Schlieren photographs, correlation of in-cylinder pressure data and Chemkin-Pro. Results show an increase in laminar burning velocity with initial temperature and proportion of dissociated methanol but a decrease with initial pressure and proportion of nitrogen. The laminar burning velocities were 25.1 cm/s, 38.7 cm/s and 83.2 cm/s respectively at stoichiometric ratio when the proportions of the dissociated methanol were 0%, 40% and 80%. Adding more dissociated methanol tends to shift the peak burning velocity towards the richer side while adding nitrogen has the opposite effect. More dissociated methanol will lead to earlier cellularity. (C) 2019 Energy Institute. Published by Elsevier Ltd. All rights reserved.