本研究採用商用型計算流體力學軟體ANSYS–FLUENT，針對上吹式挾帶床式氣化爐，建立一氣化燃燒之數值模擬分析模式。並比較不同燃燒模式對出口合成氣組成及爐內溫度分佈預測之準確性。而探討的燃燒模式包括非預混燃燒的層流火焰模式及有限速率渦流消散模式兩種。計算的結果顯示，採用有限速率渦流消散模式，所模擬的出口合成氣組成與實驗數據較一致，而非預混燃燒的層流火焰模式則低估氫氣之濃度。在出口溫度與爐內溫度分佈比較部分，也是有限速率渦流消散模式與實驗值較一致，非預混燃燒的層流火焰模式則高估了出口溫度。而在煤碳轉換率(CC)和冷氣體效率(CGE)比較方面，可得知，有限速率渦流消散模式的預測和實驗值是接近的，但非預混燃燒的層流火焰模式的預測則較為低估。因此，整體上來說，有限渦流消散模式之整體預測之準確性較非預混燃燒的層流火焰模式為佳。

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.

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