Beta型史特靈引擎性能量測與分析

The Investigation of Beta-type Stirling Engines

蘇淑君(Shu-Chun Su)

指導教授 ： 黃智永

國立清華大學/工學院/動力機械工程學系/碩士(2012年)

https://doi.org/10.6843/NTHU.2012.00161

摘要

本研究內容先進行小型Beta型史特靈引擎模組的分析，以電阻式加熱器提供史特靈引擎熱源，進而量測其效能輸出，實驗結果包括轉速、機械能、電能以及機械能損耗等。同時著手於Schmidt Theory理論分析與實驗測試之比較，而結果顯示：實驗值與理論值之差異主要是內部摩擦阻力之影響所造成。可由此結果瞭解引擎之最佳輸出操作條件，並應用於中型規模之史特靈引擎開發研究。
另外，有鑑於目前史特靈引擎內部流場分析多為CFD數值模擬分析，較少有實驗量測結果。本研究以實驗方法PIV(Particle Image Velocimetry)進行史特靈引擎內部工作流體之速度場研究，旨在研究史特靈引擎進行吸熱、膨脹、放熱與壓縮過程時，引擎內部工作流體之動向與引擎相位角關係。
　　最後，本研究亦完成中型史特靈引擎之設計與製造，並為各部件進行引擎性能提升之改善，例如採用對稱型菱形機構設計確保活塞運動的鉛直度；加熱頭之厚圓塊熱儲設計，與評估受熱效果後的材料使用修正；移氣活塞熱傳遞效果考量與輕量化；菱形機構之偏心輪與齒輪輸出自由度修正等等，同時進行引擎汽缸與活塞同軸性校正，最後則是進行中型史特靈引擎之性能量測與摩擦損耗評估。

關鍵字

史特靈引擎 ； 性能量測 ； 內部流場量測

並列摘要

This study includes theoretical analysis and experiment of a small size beta-type Stirling, following with the design and test of a medium size beta-type Stirling. A commercially available small size Stirling was examined for its power performance and the results have been compared with theoretical analysis using Schmidt theory. The small size Stirling with swept volume of 5.65 c.c can generate 0.25 W at 618 rpm rotation speed while TH equals to 410 oC and TC equals to 120 oC. However, the power output estimated by theoretical calculation is around 2.41W under the same operation condition. The cam-drive design of the small size Stirling produces the friction which dramatically decreases power output of the small Stirling engine. The flow fields in the expansion chamber inside the Stirling engine have been examined with PIV (Particle Image Velocimetry) technique. The acquired velocity profiles showing non-symmetrical vortex generation inside the expansion chamber confirm the observation of displacer deflection during its movements.

After inspecting the small size Stirling engine, a medium size Stirling was designed for manufacturing, using rhombic-drive mechanism instead of cam-drive mechanism. The medium size Stirling engine has the size of 529 c.c swept volume and it can generate 13.6 W power output at the rotation speed from 162 to 198 rpm while heating to 280 oC. The measured power output of the medium size Stirling engine is about half of the power calculated from the Schmidt theory, which is 23.8 W at the same operation condition. The power performance of the medium Stirling engine is improved by using the rhombic-drive design.

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