Influences of Different Combustion Models on the Coal-Gasification Simulation of an Entrained-Bed Gasifier

• Main Authors: Cheng-RungLei, 雷政融
• Other Authors: Tsung-Leo Jiang
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/56615855879415291703

碩士 === 國立成功大學 === 航空太空工程學系碩博士班 === 101 === In the present study, a numerical model has been developed for an up-flow entrained-bed gasifier by the commercial CFD software, ANSYS-FLUENT. The accuracy for the predicted composition of the outlet syngas and temperature distribution is compared for different turbulent combustion models. Two different combustion models including non-premixed flamelet model, and finite-rate/eddy dissipation model, are investigated. The results obtained from the present computations show that the predicted syngas composition by the finite-rate/eddy dissipation model is in better agreement with the experimental data. However, the concentration of H2 is under-estimated by the non-premixed flamelet model. Regarding the outlet temperature and the temperature distribution, the predictions by the finite-rate/eddy dissipation model are also in better agreement with the experiment. The temperature is overestimated by the non-premixed flamelet model. As far as the carbon conversion and cold gas efficiency are concerned, the predictions by the finite-rate/eddy dissipation model are close to the experimental data, while those by the non-premixed flamelet model are underestimated. On the whole, the finite-rate/eddy dissipation model is superior to the non-premixed flamelet model in the accuracy of predictions.