Сельскохозяйственные машины и технологии (Apr 2016)
Modeling of aerodynamics of flare and vortex mode in a fire chamber for vegetable waste
Abstract
At operation of fire chambers it is necessary to control amount of the air spent when fuel burning. For for this purpose scientist investigate aerodynamics of a fire chamber. On cold model we studied aerodynamic parameters of a fire chamber for plant materials, including three options of the organization of secondary blasting: from fuel input, from the opposite side and from both parties. Their influence on stability of ignition and burning of fuel was revealed. Conditions of formation of vortex circulating contours, their quantity at various giving of air in model, intensity of their rotation and dependence of an arrangement of contours from consumed concentration amount were established. As model bodies we used real objects of burning: sunflower hull and straw shreddings. As criteria of optimization of burning were degree of fullness of the chamber with a material rotating in circulating cameras and vortex rotation intensity. The minimum speed of the air given to model as primary, secondary and tertiary blasting, was limited by a constraint of not drop-out of particles from vortexes. Optimization of a given air consumption is caused by decrease in coefficient of surplus when burning (1.2-1.5). The optimum structure of a two-phase blast provides one or two circulating vortexes in the camera of model with a speed of rotation of 4; 6 and 8 meters per second at consumed concentration of 0.2-0.3 kg of material per 1 kg of air. The maximum filling of the camera and the minimum loss of particles from vortex correspond to such parameters.
