生質物於流體化床中之燃燒行為

The Characteristics of Combustion Behavior of Biomass in a Fluidized Bed Combustor

王昱棋(Yu-Chi Wang)

指導教授 ： 錢建嵩

中原大學/工學院/化學工程研究所/碩士(2017年)

https://doi.org/10.6840/cycu201700693

摘要

油茶殼與稻稈為農業廢棄物，其熱值高適合當作生質燃料，所以本研究使用兩種不同之燃料：油茶殼及稻稈，探討燃料特性與操作變數對燃燒之影響。本研究係於高4.7 m之渦旋式流體化床燃燒爐中進行，以矽砂為床質，燃燒室為0.4×0.8 m之矩形，乾舷區內徑0.64 m，二次風距分配板上方1.56 m以切線方向注入爐內，將油茶殼及稻稈分別於固定釋熱量130,000 kcal/hr，固定過量氧氣下，改變及粒徑大小及煙氣迴流模式，探討操作條件對爐體軸向溫度、軸向濃度、汙染物排放濃度、爐內熱傳管帶出之熱量、燃燒份額、灰份變化等做比較。
實驗結果顯示，油茶殼於不同粒徑燃料之CO、NO濃度差異之小，而NO排放濃度介於180至210 ppm間，當加入迴流煙氣量，CO排放濃度些微上升；破碎油茶殼之NO排放濃度上升，顆粒油茶殼之NO排放濃度下降，係因破碎油茶殼較細，較多揮發物上升至乾舷區燃燒反應生成NO，故NO之排放濃度較高；粒徑越小，床區燃燒份額隨之減少，乾舷區之燃燒份額隨迴流煙氣比率增加而有上升的趨勢；隨著迴流煙氣量增加，所收集到的飛灰明顯上升。

關鍵字

燃燒,生質物,流體化床

並列摘要

Camellia seed shell and rice straw are regard as agricultural waste. They are suitable for biomass fuel due to high calorific value. We discuss fuel property and control variable in camellia seed shell and Rice straw.
The reaction is reacted in vortex fluidized bed combustion which is 4.7 m high. Use silica sand as bed material. The combustion chamber is 0.4m long and 0.8m wide. The inside diameter of freeboard is 0.64 m. The secondary air injection levels are positioned at 1.56 m above the distributor plate. The exothermic reaction of Camellia seed shell and rice straw was fixed at 130000 kcal/hr in excessive oxygen.
The research shows that the concentration of CO and NO of is no difference in different size of camellia seed shell. The concentration of NO is between 180 to 210 ppm. The CO concentration will raise a little when fuel gas recirculation increasing. Crushed camellia seed shell product more NO than pelletized camellia seed shell. We guess that the size of crushed camellia seed shell is small than pelletized camellia seed shell. So, there is more volatile rising to freeboard and product NO. The size of particle smaller, the combustion fractions less in the combustion chamber. When there are more combustion fractions in the freeboard, the fuel gas recirculation increase. We will get more fly ash obviously when fuel gas recirculation is more.

並列關鍵字

Combustion,Biomass,Fluidized Bed

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