The Research Of Gas Fuel Oxygen-Enriched Conbustion And Its Furance Thermal Characteristic In Ceramic Kiln

Oxygen-enriched combustion technology is a new type of energy-saving technology, which could increase flame temperature, reinforce radiation heat transfer capacity, improve efficiency, extend the life of furnaces, energy-saving and environmental protection and so on. Applying oxygen-enriched combustion technology in ceramic kiln, not only meets technological requirements of ceramic, improves yield and products quality, but also can significantly reduce the amount of waste gas emissions volume, energy-saving and emission reduction effect is significant. It is a better solution to solve high energy consumption, serious environmental pollution problem and other existing problem in ceramic industry.Currently the thermal characteristic research of oxygen-enriched combustion technology in kiln mainly by numerical simulation method, and the oxygen-enriched combustion characteristics of gas fuel have to be further. This topic choosing oxygen-enriched combustion test bed as research object, using liquefied gas as fuel and through preparing oxygen-enriched air with oxygen concentration in21%-30%for combustion experiment. By studying the effect of oxygen concentration variation on flame characteristics, furnace thermal characteristics and energy-saving, analyzing the actual use characteristics of oxygen-enrich technology, exploring the effective way to improve efficiency, reduce energy loss and providing a basis for kiln design, spray gun arrangement and the practical use of oxygen-enriched combustion technology in the ceramic kiln.According to the research, draw the following conclusions:In the process of oxygen-enriched combustion, the combustion reaction rate speeds up, the flame propagation velocity increases, burning path gets shortered, leading to the flame shorters, combustion area decrescent contracts; With the increasing of oxygen concentration, average temperature of flame increases, flame temperature fluctuations abates and axial flame temperature decreases with the increasing distance from the spray gun mouth. When oxygen concentration between27%~30%, high temperature flame mainly concentrated to the spray gun mouth within0.5cm to3cm area; Flames cover area smaller, flame temperature decrease, the high temperature area of the flame gradually shrunk to spray gun.The over1200℃high temperature area of temperature field in the furnace shrinks to near the spray gun, the moderate high temperature area of1200℃-500℃extends and the low temperature area behind500℃disappears. When preheating combustion air flame speed increases, flames burned areas are more concentrated. The moderate high temperature area of temperature field contracts, and contracting faster at higher temperature. Therefore, when applying oxygen-enriched combustion on ceramic kilns, the influence of short flame to the furance temperature should be paid attention to abated.When applying oxygen-enriched combustion technology, CO will significantly reduces, the radiation rate of flue gas improvess, the general heat transfer coefficient within kiln increases and heat transfer capacity enhances. The comprehensive heat transfer coefficient improves great when oxygen concentration in the range of24%~30%, but the heat transfer ability change a little with oxygen concentration.Thermal NOX concentration in general increases with oxygen concentration, grows at a lower speed in21%to27%of the low oxygen concentration and rapidly grows at high oxygen concentration; Flue gas emissions heat loss decreases, in the premise of fixed heat income, the effective use of kiln heat increase, and the heat efficiency is improving, fuel consumption drop, energy saving effect is remarkable.