本研究針對固定床下吸式氣化爐結合Gamma 型史特林引擎之熱電聯產（CHP）系統進行設計與性能實驗，探討燃料填充量與空氣流量變化對系統電功輸出、熱效率與氣體生成行為之影響。研究動機在於開發一套適用於農業廢棄物資源化與偏遠地區分散式發電的高效率生質能應用技術。實驗中採用木質生質顆粒作為燃料，設置三種填充量（1、2、3 公斤）與三種空氣流量（60、65、70L/min），並量測合成氣成分、CO濃度變化、史特林引擎輸出電功率與各項效率指標（熱效率、電效率與整體效率）。實驗結果顯示，在1 kg填充量條件下，CO濃度快速衰減且反應時間較短，發電系統僅輸出133 W至 148 W電功，電效率介於1.4% 至 1.6%，整體熱效率約 23%，不利於長時間穩定運作。2 kg填充量下，系統進入穩定反應區段，CO濃度維持時間延長，氣化行為穩定，於不同空氣流量下輸出功率為171 W至194 W，電效率提升至1.9%~2.1%，整體熱效率提升至26.7%~31%。在3 kg 填充量下，系統達最佳性能，觀察到CO濃度出現典型熱解與還原反應雙波峰特徵，並在部分實驗中觀測到第三波峰現象，推測與單次大容量進料導致燃燒區推進與擴散控制困難有關；在70L/min 空氣供應下，史特林引擎的運轉轉速可達397 rpm，輸出電功率210 W，電效率穩定於 2.0%~2.1%，整體熱效率最高達39.5%。
此外，本研究針對CO濃度變化曲線進行動態分析，結果顯示CO濃度可作為反應階段（熱解、燃燒、還原）與燃料反應趨勢之關鍵指標。CO高原期的長短、波峰結構與衰減斜率反映出系統熱場穩定性與燃料反應完成度，亦可作為日後系統監控與控制策略之依據。整體而言，本研究證實下吸式氣化爐結合 Gamma 型史特林引擎具有高度系統整合潛力與運作穩定性，適合應用於永續生質能轉換領域；未來系統最佳化操作應綜合考量燃料填充量、空氣供應量與燃燒區域控制之耦合效應，以提升發電效率與氣體品質。

This study investigates the performance of a downdraft biomass gasifier system integrated with a γ-type Stirling engine for syngas-based power generation. The gasifier was operated under varying conditions of air flow rate (60, 65, 70L/min) and biomass loading (1, 2, 3 kg) to analyze the influence on syngas composition and overall system efficiency. The syngas produced was used as the external heat source to drive a 500W γ-type Stirling engine using hydrogen as the working fluid. Experimental results indicate that increasing biomass mass enhances both syngas yield and energy conversion efficiency. The carbon monoxide concentration displayed a two-peak trend in most conditions, suggesting an initial pyrolysis-dominated stage followed by a reduction-dominated phase. The highest total efficiency reached 39.5% under the condition of 3 kg biomass and 70L/min air flow. Additionally, CO and CH₄ concentration patterns, along with visual flame characteristics, were used to interpret the reaction mechanisms during gasification. This research demonstrates the feasibility and limitations of using biomass-derived syngas for small-scale, distributed power generation and provides insights for future system optimization in hybrid thermal-electric applications.

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