稻穀燃燒爐之性能測定及設計改良

Burning Efficiency Analysis and Improvement of Rice Hull Furnaces

張壽山(Shou-Shan Chang) ； 吳軍港(Chun-Kang Wu) ； 吳柏青(Po-Ching Wu)

《農業機械學刊》 20卷1期 (2011/03) Pp. 1-11

https://doi.org/10.30062/JAM.201103.0001

摘要

稻殼為農業副產品，約佔稻穀的18～20%。2006年台灣稻殼產出量約為296,020公噸，若此數量的稻殻能完全被燃燒利用，則總燃值相當於1.26億公升柴油，並等同於34.9億元之柴油價值。稻殼過去多採以露天棄置與焚燒處理，因國際原油價格攀升，故可將稻殼作為加熱燃料以降低乾燥成本。本研究針對已商品化的太陽牌，AU-614B型稻殼燃燒爐進行性能測定與設計改良。由稻殼與碳化稻殼之灰分測定，修正稻殼燃值為14,444 kJ/kg。經實機測試並推算出該型爐之燃燒效率為51.9%。根據管排（Tube Bank）原理，在固定熱交換層尺寸、熱風體積流率、稻殼質量流率時，針對不同管徑的商業規格鋼管進行熱交換層排列比較。若為定管距排列方式，管徑增加可提升熱交換層之理論熱效率，亦增加系統壓降及風機負載；若於固定管間隙排列方式管排，採用管徑為76 mm（3 in）時，則熱交換層所能產生的理論熱效率較其他三種管徑者高，且系統風機能達到較低負載。

關鍵字

稻殼 ； 燃燒爐 ； 燃燒效率 ； 管排分析

並列摘要

Rice hull is a agricultural by-product, paddy rice contains approximately 18~20% of rice hull by weight. In year 2006 Taiwan produced 296,020 million tons of rice hull. If this amount of rice hull could be used for burning as fuel, the total heating value was equal to 1.26 hundred million liters of diesel fuel, and worth 34.9 hundred million NT dollars. In the past, most of the rice hull was dumped in the open field and burned down. However, the international crude oil price was climbing up, the rice hull can be used as heating fuel to cut down the drying cost. This study was to evaluate the performance of the commercial rice hull combustion furnaces (SUN, Model: AU-614B) and to improve its design. Based on the determination of ash content for rice hull and charcoal, the heating value of rice hull was adjusted to 14,444 kJ/kg for this type rice hull combustion furnace. The heating efficiency was 51.9% for AU-614B. Based on the Tube Bank theorem, the performance of heat exchanger with different commercial tube diameter was evaluated under fixed heat exchanger dimension, volume flow rate of heated air, and mass flow rate of rice hull. Under the tube arrangement with fixed center distance, increasing the tube diameter will increase the theoretical heating efficiency, the system pressure drop and the power loading of air blower. Under the tube arrangement with fixed tube clearance, 76 mm (3in) of tube diameter will perform with the highest theoretical heating efficiency and the lowest power loading of air blower.

並列關鍵字

Rice hull ； Furnace ； Burning efficiency ； Tube bank analysis