臺灣博碩士論文加值系統

本文探討煤炭燃燒時，粉煤管內粉煤流量有效率的控制方式。藉著煤管內煤流率的量測及孔口限流板的應用，使各分支粉煤管的空氣與粉煤混合物流量偏差減至最少，用以提高鍋爐燃燒效率及降低煙氣環保排放物對大氣的衝擊。在進行各粉煤管流量偏差平衡測試時，本研究選擇微波技術之粉煤流量測定方法，實際應用在台中電廠二號機鍋爐，調整粉煤機各支粉煤管流量偏差平衡。
由進行粉煤機四支粉煤管試驗，分別以試驗評估動態分煤器轉速和空氣與煤量體積設定比(空燃比)改變及不同煤質，得到影響粉煤平衡偏差的重要因素如下：當動態分煤器轉速愈高，較小顆粒粉煤百分比增加，即粉煤細度愈小，粉煤流量偏差值愈趨平衡，若分煤器轉速低於75RPM時，粉煤流量偏差值將超出目標值；當空氣與煤量體積設定比愈大時，空氣量增加，粉煤機內煤粒運動速度加快，空氣輸送大顆粒粉煤量增加，雖然使影響粉煤細度變大，但所得粉煤流量偏差愈小；煤炭來源種類雖然經常改變，但改變另一種不同煤質時，煤炭熱性質及顆粒特性變更，對於粉煤流量偏差平衡影響不大。

The effective control mode of the coal flow rate inside the coal pipes of the coal-fired power station is investigated in this paper. With the purpose of increasing the burning efficiency of the boiler and also lowering the pollutant emissions of flue gas to the environmental atmosphere, the coal flow rates on every coal pipes are measured and adjusted by an orifice type restrictor such that the coal flow deviations of the coal pipes are reduced to a minimum. The coal flow distribution tests are performed using the microwave-based coal flow measurement system. The boiler No. 2 at the Taichung Thermal Power Station was selected to test the flow balancing of the pipe-to-pipe coal flow distributions of the pulverizer.
The experimental results show that as the speed of the rotating dynamic classifier increases, the finer grain size of the powdered coal will be obtained. The small deviation of the coal flow rate is attained due to the percentage increase of the coal powder toward the small grain size distribution. The deviation of the coal flow rate will exceed the upper limit of the target value, if the speed of the rotating dynamic classifier is lowered to 75 rpm. The increasing air flow for the case of higher air/coal ratio helps the transport of large coal particles, and the better balance of the coal flow rate is achieved. It is noted that the coal thermal properties and the coal grain characteristics from different mining area affect rarely the balance of coal flow rates.

中文摘要………………………………………………………… i
英文摘要………………………………………………………… ii
誌謝……………………………………………………………… iii
目次……………………………………………………………… vi
表目次…………………………………………………………… vii
圖目次…………………………………………………………… ix
符號索引………………………………………………………… x
第一章 緒論
1.1前言……………………………………………………… 1
1.2文獻回顧………………………………………………… 1
1.3研究動機………………………………………………… 5
第二章 粉煤管流量平衡理論
2.1粉煤系統結構及規範…………………………………… 6
2.1.1粉煤機設備描述……………………………………… 10
2.2髒空氣流速測量………………………………………… 12
2.3粉煤細度取樣…………………………………………… 14
2.4微波測量粉煤管流量偏差……………………………… 17
2.5修正粉煤管流量偏差…………………………………… 21
2.6流量偏差分析…………………………………………… 22
2.6.1一次空氣量與粉煤量比例改變分析………………… 22
2.6.2動態分煤器轉速改變分析…………………………… 23
2.6.3煤質改變分析………………………………………… 23

第三章 系統操作與測試
3.1粉煤管流量偏差測試設備……………………………… 24
3.2粉煤管流量偏差測試…………………………………… 27
3.3修正流量偏差縮流孔尺寸計算………………………… 27
3.4平衡粉煤管流量偏差結果……………………………… 29
3.5粉煤管流量分佈及平衡………………………………… 31
3.6髒空氣流速測試………………………………………… 35
3.7髒空氣流速測試結果…………………………………… 39
第四章 粉煤流量偏差測試結果影響分析
4.1一次空氣量對粉煤流量比例推導……………………… 41
4.2動態分煤器轉速關係…………………………………… 42
4.3煤質改變分析…………………………………………… 43
第五章 結論與展望
5.1結論……………………………………………………… 45
5.2未來展望………………………………………………… 46
參考文獻……………………………………………………… 47
附錄A
A-1 #1粉煤管平衡前流量變動及曲線分佈………………… 49
A-2 #1粉煤管平衡後流量變動及曲線分佈………………… 4
A-3 #2粉煤管平衡前流量變動及曲線分佈………………… 50
A-4 #2粉煤管平衡後流量變動及曲線分佈………………… 50
A-5 #3粉煤管流量變動及曲線分佈………………………… 51
A-6 #4粉煤管平衡前流量變動曲線分佈…………………… 51
A-7 #4粉煤管平衡後流量變動及曲線分佈………………… 52
A-8 #5粉煤管平衡前第一次流量變動及曲線分佈………… 52
A-9 #5粉煤管平衡前第二次流量變動及曲線分佈………… 53
A-10 #5粉煤管平衡後流量偏差曲線分佈…………………… 53
A-11 #6粉煤管平衡前流量偏差曲線分佈…………………… 54
A-12 #6粉煤管平衡後流量偏差曲線分佈…………………… 54
A-13 #1粉煤管煤炭水份高流量偏差曲線分佈……………… 55
A-14 #2粉煤管煤炭水份高流量偏差曲線分佈……………… 55
附錄 B
B-1 #1粉煤機各粉煤管動壓值……………………………… 56
B-2 #2粉煤機各粉煤管動壓值……………………………… 57
B-3 #3粉煤機各粉煤管動壓值……………………………… 58
B-4 #4粉煤機各粉煤管動壓值……………………………… 59
B-5 #5粉煤機各粉煤管動壓值……………………………… 60
B-6 #6粉煤機各粉煤管動壓值……………………………… 61

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