Measurements of the laminar burning velocity for propane: Air mixtures

In this research, an experimental setup was built based on using K-type thermocouples inserted in a cylindrical vessel and coupled with a computer system to enable online reading of flame speed for propane-air mixtures. The work undertaken here has come up with data for laminar burning velocity of the propane-air mixtures based on three initial temperatures Tu = 300, 325 and 350 K, three initial pressures pu = 0.5, 1.0 and 1.5 bar over a range of equivalence ratios ϕ between 0.6 and 1.5. The results obtained gave a reasonable agreement with experimental data reported in the literature. Results showed that laminar burning velocity increases at low initial pressures and decreases at high pressures, while the opposite occurs incase of temperatures. The maximum values of the laminar burning velocity occur at T = 350 K, pu = 0.5 and ϕ = 1.0, respectively, while the minimum values of the laminar burning velocity occur at T = 300 K, pu = 1.5 and ϕ = 1.2. Also, the influence of flame stretching on laminar burning velocity was investigated and it was found that stretch effect is weak since Lewis number was below unity for all cases considered. Based on experimental results, an empirical equation has been derived to calculate the laminar burning velocity. The values of the laminar burning velocity calculated from this equation show great compatibility with the published results. Therefore, the derived empirical equation can be used to calculate the burning velocities of any gas of paraffin gas fuels in the range of mixture temperature and pressure considered.