Design And Experimental Studies Of Air+Oxygen Swirl Burner

The thermal power plants are the main areas of China’s coal consumption andpollution emissions, has a pivotal role in the achievement of the national energy savingtargets. It is imminent to improve the Coal-fired power plant boiler’s efficiency and controlpollutant emissions. Oxygen-enriched combustion is a new type of energy-savingtechnologies, compared with the ordinary combustion, it needs less theoretical air, higherflame temperature, higher combustion speed. In this paper, an Air+Oxygen swirl burnerwas designed to reduce the coal-fired boiler’s exhaust gas heat loss, so as to improve theboiler’s combustion efficiency. Meanwhile, the increase of the concentration of pollutants inthe flue gas also makes the control of SOxand NOxmore effective.This paper describes the design principles of the swirl burner and design basis of theAir+Oxygen swirl burner (AOSB). The structure of AOSB was designed in detail,including the design of air ducts and their ways of intake, the design of the swirler and theflaring choice. Then the overall oxygen concentration of the burner was selected, the sizesof the air ducts and the swirling strength were calculated in detail. Cold aerodynamic fieldof the AOSB was studied. The characteristics of recirculation zone conditions and jetexpansion angle of the burner outlet were analyzed by measuring axial velocity field. Thehybrid test was carried out on the base of cold test. The oxygen concentration field of theburner outlet was measured, focus on the effect of aerodynamic field on distribution ofoxygen concentration. Integrated cold test and mixed test results on AOSB burner, theactual combustion performance was analyzed.The study shows that: AOSB has obvious recirculation zone, the axial dimension ofthe recirculation zone decreases with the decreasing of oxygen concentration, extensionangle showing the trend of increased and then decreased. The oxygen concentration wassaddle-shaped, distributed along the burner center axis symmetrically, it elevated and thenreduce along the center to the sides.The maximum oxygen concentration exists betweenthe two boundary lines or boundary line of oxygen and the first air.