Study On High Temperature Air Combustion Of C₃H_s In Flue Gas Auto-circulation Heating Furnace

This paper uses the flue gas anto-circulation burner which is designed on the earlier stageto build the circulation laboratory bench. This experiment platform is consist of burningsystem, the combustion of auxiliary systems and measurement system.In the existing experimental condition, this paper analyzes the feasiblity of theexperiment schemes. The experiments are carried out using propane(C3H8) as fuel at the fuelflow of M= 0.4 m~3 / h and M=0.6 m~3 / h respectively.The results show that the high temperatureareas and NO high concentration areas are both in the first half of the furnace. And thecontrast experiments are proceeded with ejector backflow and without ejector backflowrespectively. The results of the contrast experiments show that the circulation of hightemperature flue gas plays an important role in reducing NO formation, and reducing thetemperature of chamber export so that the heat loss is lowered. The simulation areaccomplished in the conditions of experiments by using FLUENT software, and thesimulation results have good conformity in the overall trend with the datas from experimentalmeasurements.To improve the combustion system and enhance combustion in the chamber, this paperproposes to change the flue gas ejector position and study it with the method of numericalsimulation. The simulation results show that in the constant heat flux boundary conditions, itis helpful for reducing the highest temperature and average temperature of furnace when theejector position is near the end of the chamber, and then reducing the smoke heat loss.Meanwhile, it is more helpful for reducing NO concentration when the ejector position iscloser to the end of the chamber, which can reduce the NOx emissions, so ejector position canbe choosed near the end of the furnace.