Measurement of laminar burning speed of isobutane and carbon dioxide mixture

• Online Access: http://hdl.handle.net/2047/D20317907

Isobutane is a chemical compound with molecular formula HC(CH3)3. It can be used as a refrigerant, which has negligible ozone depletion potential and very low global warming potential. In order to reduce its burning speed, carbon dioxide is added into the isobutane refrigerant. Thus, in this study, the laminar burning speed of mixture of isobutane and carbon dioxide and air has been measured. There are several methods to calculate the laminar burning speed. In present work, the experiments were conducted in a constant volume cylindrical chamber. The pressure rise due to combustion was obtained by the pressure transducer on the top of cylindrical chamber. Burning speed was calculated by a thermodynamic model with the pressure data as an input. Laminar burning speeds were measured at different initial pressures P_i, different concentration of carbon dioxide (α) and different equivalence ratios (ϕ). The initial pressure data are 0.5 atm, 1 atm and 2 atm. The concentrations of carbon dioxide are 0%, 20%, 40%, 60% and 80%. The equivalence ratios are 1, 1.1 and 1.2. Laminar burning speed has been measured for temperatures ranging from 298 K to 480 K, pressures between 0.5 to 5.2 atmospheres and equivalence ratios ranging from 1 to 1.2.