小型都市垃圾焚化爐燃燒熱流場之模擬

Modeling of Small-Scaled Municipal Solid Waste Incinerators

陳康興(Kang-Shin Chen) ； 吳中興(Chung-Hsing Wu) ； 唐祺夏(Chi-Hsia Tang)

《農業機械學刊》 6卷2期 (1997/06) Pp. 55-68

https://doi.org/10.30062/JAM.199706.0006

摘要

以焚化處理廢棄物具有減量化、安定化、衛生化和資源化等優點，故可有效解決地狹人稠及大量廢棄物產生的問題，並將成為台灣地區未來處理固體廢棄物（特別是都市垃圾）的主要方式之一。本文旨在以理論及數値分析法模擬混燒式都市垃圾焚化爐內的熱流場及燃燒生成氣體(包括CH4、CO2、O2及H2O)的分佈狀態、混合特性，並探討空燃比對燃燒效率之影響。其研究成果，有助於對燃燒設計、分析能力之提升，並對影響操作條件因子之了解有所助益。研究結果顯示，當爐內過剩空氣比100%（一次空氣佔80%，二次空氣佔20%）時，在二次空氣入口及灰渣出口有迴流區形成。高溫及火焰區域氧化反應較完全，CO2及H2O濃度較高；CH4及CO濃度在低溫區域較高。二次燃燒室提供了足夠的停留時間，使得未反應的CH4及CO在二次室內繼續與氧反應，所以在二次燃燒室內CH4濃度趨近於零，CO2及H2O濃度較高。出口氣體的溫度隨著過剩空氣量的增加而降低。

關鍵字

紊流 ； 燃燒 ； 過剩空氣

並列摘要

The advantages of minimization, stabilization, sanitization, and energy recovery by incineration treatment have made it an effective way to deal with large amount of municipal solid wastes produced regionally or worldwide. This is especially the case for a densely populated island, like Taiwan. In this paper, steady, two-dimensional, turbulent, burning flow are investigated by finite element simulation for a municipal solid incinerator (MSI) to advance the knowledge of flow structures, species distributions, and mixing behaviors in the combustion chamber under various operation conditions. Results show that there is a recirculation zone near the entrance of SCC (the second combustion chamber) due to a protruded rib there. Most methane is burned above the grate in FCC (the first combustion chamber) where temperature is high and [O2] is low. Along the inclined grate, one or two flame fronts appear in the rear of drying zone, and five or six flame fronts appear in the burning zone. Postflam oxidation is accomplished by the additional mixing and reaction of gas stream in SCC, where [CO2] is much higher. The exit temperature decreases when amount of excess air is increased.

並列關鍵字

Turbulence ； Combustion ； Excess air ； Municipal solid incinerator