Combustion Science and Technology, Vol.143, No.1-6, 63-77, 1999
In-situ species, temperature and velocity measurements in a pulverized coal flame
A study of detailed species, velocity and temperature data of a pulverized coal flame is important to understanding the mechanisms which sustain the flame and lead to the formation of various pollutants such as NOx. The data can be particularly useful when compared to comprehensive combustion models which encapsulate the sub-models and processes of combustion. This data set contains in-situ axial and radial temperature, velocity and species concentrations for three swirl ratios of a pulverized coal name located in a cylindrical, down-fired, 0.2 MW,reactor Species measurements include CO, CO2, NO and O-2. Velocity measurements were obtained using Laser Doppler Anemometry (LDA) and are summarized here after the method and results were reported in detail in a companion paper. The data show the change in structure of the coal flame as swirl is increased. At zero swirl the flame was located along a centerline jet, but as swirl increased, a recirculation zone was created which carried the combustion products up along the centerline of the reactor. Effluent NO was found to correlate with the recirculation of products into the devolitilization zone and with the evidence of reduced mixing of fuel and secondary air at the primary tube outlet. Species measurements agreed with LDA results where concentration of O-2 were highest in the region of the secondary air jet. The species and temperature measurements are self consistent suggesting the data is accurate and will be useful when compared to combustion models.