應用於生質沼氣系統之Beta型史特靈引擎開發實作與分析

Abstract

本研究目前已製做出一台活塞掃除體積142.7 c.c. 並使用菱型機構的beta型史特靈引擎原型機，引擎理論功率可達34.79 W，但尚未能完成啟動工作，因此以啟動馬達帶動引擎並透過扭力計進行阻力扭距的量測，以引擎加熱後所減少的阻力推算引擎提供的功率。 從初期的原型機開始，對引擎進行了以下優化過程：製作了新版齒輪箱並對菱型機構重新進行精密加工；改用陶瓷電加熱器做為熱源輸入，並重新製作了加熱頭和移氣器來配合電加熱器使用以達到最佳的加熱效率；在氣缸外新增了氣壓計來確認引擎的漏氣情況；在製作了增加鐵氟龍環的活塞，並在移氣器連桿和活塞連桿之間加上自潤軸承。 引擎在優化設計後，摩擦阻力由原本的0.47 N·m降至0.19 N·m，摩擦損失率由29.7 %降至12.0 %，引擎經由陶瓷電加熱器加熱至700°C後，可提供約9.01 W的功率，由於氣密不良的關係引擎仍有8.58 W的阻力損失功率需要克服。

In this study, a beta type Stirling engine prototype with piston sweep volume of 142.7 c.c. and a rhombic mechanism was made. The theoretical engine power was up to 34.79 W. However, the engine could not be activated yet, Consequently the engine was driven by a starter motor and the power provided by the engine was derived from the reduction in drag after the engine was heated. Starting from the initial prototype, the following optimization processes were carried out: a new version of the gear box was made, and the rhombic mechanism was reworked by precision machining; a ceramic electric heater was used as the heat source , and the heating head and displacer were rebuilt to work with the electric heater to achieve the best heating efficiency; a new air pressure gauge was added outside the cylinder to check the air leakage of the engine; pistons with a Teflon ring were made, and self-lubricating bearings were added between the displacer connecting rod and the piston connecting rod. After optimizing the engine design, the frictional resistance was reduced from 0.47 N-m to 0.19 N-m, and the frictional loss rate was reduced from 29.7 % to 12.0 %. The engine was heated to 700°C by a ceramic electric heater, which could provide about 9.01 W of power. The engine still needed 8.58 W to overcome due to insufficient sealing.