以回收廢熱為目的之外加熱型汽化器的最佳化設計

Optimal Design of the External-heating Gasifier based on Waste Energy Recycling

前，如何提高能源使用效率已成為環保工作的重要課題之一。具有高燃燒 效率及零排放的氫氣將可以解決目前環境問題。一般來說，氣化器常被當成以媒 及生物質等廉價燃料中生產氫氣，在生產氫氣的過程中會產生 COx 但同時也可 以用來發電。本文提出一種混和系統能降低氣化器對於 COx 的排放量，並減輕 燃料電池（例如 SOFC）所造成的熱汙染。為了最佳化系統的熱回收效率，先設計 出外部加熱熱式氣化器，並以田口方法找出影響熱交換效率的重要因子，最後利 用多重 ANFIS(Adaptive Neuro-Fuzzy Inference System)來解決多目標輸出的問 題，並得到最佳參數。模擬結果中證明與現有的氣化器相比，最佳化受系統效率 提高的 53%左右。因此證明此系統不僅可以提高能源使用效率，且可以降低 COx 氣體排放及熱污染的問題。

Nowadays, how to improve the energy efficiency has become one of the important issues to environmental protection. Hydrogen with high combustion efficiency and zero emission is expected to be the solution for above issue. In general, gasifiers are often used to be the transformers to generate hydrogen form the cheap fuel such as coal and biomass etc.. However, the exhaust gas COx is also discharging during hydrogen generation. In this paper, a hybrid system which can simultaneously minimize the COx emission of gasifier and relieve the thermal pollution of fuel cells (e.g. SOFC) is proposed. In order to optimize the heat recycling efficiency for the proposed system, first, the external-heating gasifier is design. Next, the Taguchi's method is used to find out the important factors which mostly affect the heat exchanging efficiency. Finally, the multiple ANFIS (adaptive neuro-fuzzy inference system) is adopted to serve the multi-object problem to obtain the optimal parameters for the design. The simulation results shows that to compare with the existed gasifier there about 53% of efficiency improvement can be achieved by the optimized system. Consequently, it corroborated that this system is not only can improve the energy efficiency, but also can relieve the COx gas emission as well as the thermal pollution problem.