Simulation of Flameless Combustion of Diesel Oil

01.Dec.2018

​In this work, the combustion process of diesel (C_12 H_23) in an industrial scale burner under flameless expected operating conditions has been modeled and simulated using Ansys/Fluent software. A wide range of affecting parameters has been analyzed to investigate the applicability of utilizing such liquid fuel for the proposed flameless combustion mode. Natural recirculation of the reaction produced flue gases due to the selected velocity difference between the six fresh air inlets, and the central fuel injection nozzle. This recirculation affected the flame characteristics by diluting the oxidant concentration into the reaction zone to be within 3-9% instead of 21%. On the other hand, the recirculation cools down flame reaction zone to 1200 K in order to aid the auto-ignition of the non-premixed combustion process, whereas fresh air is preheated to 800 K. Upon achieving flameless combustion conditions numerically in this study, considerable reduction of maximum operating temperature of around 1600 K has been reached in most cases, with homogeneous temperature profiles of almost no hot spots. Environmentally, flameless mode showed very friendly environment behaviors where NO_x formation rate can be considered nil and does not exceed few ppms. Moreover, the combustion process was completed within a compact design since nil concentration of CO was obtained, with stoichiometric concentrations of CO_2 and H_2 O. The obtained results were compared with previous results of similar theoretical modeling of flameless combustion for similar liquid fuel, where good agreement was found.

https://www.researchgate.net/publication/330144871_Simulation_of_Flameless_Combustion_of_Diesel_Oil​