Experimental Studies on Combustion and Heat Transfer Characteristics in a Furnace

摘要

Two types of fuel nozzle are used in a cylindrical furnace which is 1 m in inner diameter and 4 .8 m in height. The one is axial injection type with single hole (nozzle 1) where fuel and air flow in the same direction coaxially upward. The other is radial injection type with multi holes (nozzle 2) where fuel and air flow in the crosswise direction. Two types of fuel nozzle form extremely different types of turbulent diffusion flames. Nozzle 1 forms a long flame, while nozzle 2 forms a short flame with recirculating zone at the center of the flame just above the nozzle tip. Measurements of profiles of temperature, species concentration, together with the heat flux to the furnace wall are carried out in a turbulent diffusion flame of propane. Their interconnections with combustion and heat transfer characteristics are investigated and discussed under various furnace operating condition of air swirling, inlet air temperature, recirculating exhaust gas, air ratio, fuel flow rate and type of nozzle.