Investigation of Turbulent Flame Structures and Performance Evaluation of Municipal Waste and Rotary Kiln Incinerators

• Main Authors: HO YI-TA, 何宜達
• Other Authors: K.S.Chen
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/47527080393782203844

碩士 === 國立中山大學 === 環境工程研究所 === 86 === Finite element simulation are presented to advance the knowledge of flow structures, species distributions, and mixing behaviors of turbulent burning flows in municipal waste incinerators and rotary kiln under various operation conditions. The modified κ-ε turbulence model together with wall functions was adopted. Devolatilization of solid wastes were simulated by gaseous methane (CH4) non-uniformly distributed along the inclined grate. Combustion process was consider as a two-step reaction when primary air entered and mixed with methane gas in the first combustion chamber. Mixing-controlled eddy-dissipation model was employed for predicting the reaction rates of CH4, O2, CO2, CO and H2O. In addition, thermal NOx was the product of N2 and O2 in high temperature. Both Zeldovich-mechanism and eddy-dissipation models were considered in order to analyze the reaction rate of thermal NOx. Results show that suitable addition of 100% excess and 20-30% second-air will improve the combustion efficiency. The higher temperature of primary air will let the combustion efficiency more higher, but it may increase the thermal NOx.