Effects of Spray Characteristics on Ignition Process in Spray Combustion
In order to study the effects of spray characteristics on ignition process in spray combustion,the variation of flow characteristics, spray cone angle, circumferential non-uniformity, sauter mean diameter (SMD) and droplet size distribution index (N) were measured by the Malvern laser particle size analyzer. The ignition process and combustor outlet temperature were recorded by the high-speed camera and thermocouple temperature measurement system. The initial flame formation and flame propagation processes were revealed. The effects of atomizer atomization characteristics on the initial flame formation,flame propagation processes,tem?perature rise rate, start and the maximum time of combustor outlet temperature rise were discussed. The results showed that with the increase of the fuel pressure,the flow rate of the pressure-swirl atomizer increased present?ing a quadratic curve relationship, SMD gradually reduced, and droplet size distribution index initially de?creased and then increased. When the ignition fuel-air ratio was between 0.0078 and 0.0125, with the increase of fuel pressure,the flame initially propagated near the top of the combustor,afterwards it moved to the bottom of the combustor. The length of initial flame increased and flame became brighter. Also the start time of combustor outlet temperature rise was reduced, the maximum temperature rise time, temperature rise rate and the maxi?mum temperature increased. For the same fuel-air ratio, the temperature rise and temperature rise rate of the TC-1 thermocouple were the highest and the start time of temperature rise was the minimum at the position of 1/4H from the upper wall of combustor.(H means height of combustor). Meanwhile the temperature rise and tem?perature rise rate of the TC-3 thermocouple were the lowest and the start time of temperature rise was the maxi?mum at the position of 3/4H from the upper wall of combustor.
Spray combustionSpray characteristicsIgnition process
NETL
NSTL
万方数据
维普
