Experimental Investigation On The Combustion Of Higher Efficiency,Lower Emission Effervescent Atomizer

In recent years, the consumption of energy increased rapidly with the development of the national economy. It is very important for the future of the energy and environment protected to develop higher efficiency, lower emission combustion device, because the environmental pollution is becoming worse and worse.Effervescent atomizer is a new-style nozzle, and it was provided many characteristics with high quality spray, low air consumption, so it is suitable for atomizing liquid fuel such as heavy oil. Therefore, we designed a porous effervescent atomizer. In this paper, experimental investigations have been conducted on the combustion characteristics of effervescent atomizers, and the experimental data could provide guidance for the designing of atomizers.Two types effervescent atomizers were tested in this work, Particle Dynamic Analyzer were used to measure and analyze the atomization performances and flow characteristics. A combustion chamber was devised to investigate the combustion characteristics of effervescent atomizers. In this combustion chamber we studied on the distribution of temperature, the elements of exhaust gas, the effects of air-to-liquid and the effects of gas recirculation.A Test350 Fuel Gas Analyzer was used to measure and analyze the elements of exhaust gases and the distribution of temperature at different conditions. It was found that the fraction of CO₂ is 13.7% when the excess air is 16%, which is correspond with theoretical prediction. As the fraction of O₂ is 4% and excess air is 20%, the fractions of CO, C_mH_n and H₂ are 200ppm, 600ppm and 100ppm respectively. Those data prove that the combustion efficiency of spray flame is high enough. At the same conditions, the fractions of NO_x and SO₂ are 70 ppm and 60ppm respectively, the emission level of pollution is lower than other burners. Commonly, the fraction of CO, C_mH_n, H₂ and SO₂ decrease with the increasing of excess air. But the fraction of NO_x increases slightly as the excess air is higher, that can be explained by the theory about the formation of thermal NO_x It was found that air-to-liquid has a remarkable effect on exhaust gases. Exhaust gas recirculation could strengthen the process of evaporation of droplets, so shorten the length of flame. At the same time, the exhaust gas dilute the oxygen in high temperature zone, reduces the NO_x emission.The investigation of this work reveal roundly the spray characteristics and combustion characteristics of effervescent atomizer, and the experiment data have a great significance for developing a higher efficiency, lower emission effervescent atomizer.