摘要: | 本論文建立了Alpha 型史特靈引擎的二階數學模式與曲柄動力數學模式,以及太陽能集光碟之設計模式。利用這些模式,本論文完成了一個以氮氣為工作流體,由柴油引擎改裝之史特靈引擎的性能模擬與最佳化分析,且決定出史特靈引擎可提供給海水淡化薄膜蒸餾系統之能量。 相較於基本設計,最佳設計之篩網空隙率由0.489 調降為0.3,冷卻器長度減半,再生器通道高度減半。性能分析顯示引擎操作於0.45-3.1 MPa,工作流體溫度介於282-709 K,再生器效能達83.87%,引擎對外輸出功率為9.85 kW,熱效率為33.85%,轉動頻率為852 rpm。 集光碟之輻射接收面積約為32.4 m2。當再生器熱傳係數使用Kelly and McLand (2007)關聯式,在高輻射強度830 W/m2 且引擎工作流體之總質量分別為18.16、27.26 與36.32 g 時,引擎可輸出功率分別為7.89、8.42 與8.4 kW。中輻射強度670 W/m2 且總質量分別為27.26 與36.32 g 時,引擎可輸出功率分別為7.37 與7.4 kW。再生器熱傳係數若使用Gedeon and Wood (1996)之關聯式,在高輻射強度下且總質量分別為18.16、27.26 與36.32 g 時,引擎可輸出功率分別為7.88、8.22 與8.21 kW。中輻射強度下且總質量分別為27.26 與36.32 g 時,引擎可輸出功率分別為7.2 與7.24 kW。在低輻射強度560 W/m2,因能量太低,無法驅動引擎轉動。 This study has established a second order mathematical model of alpha type solar powered Stirling engine, and solar collectors of design. The study simulates a diesel engine with nitrogen as the working fluid, basic design analysis and optimal design, and the decision the Stirling engine supply the desalination membrane distillation system energy. The simulation of the optimal design case reveals the cyclic operating conditions of the working gas and the solid temperatures. For the gas, the pressure ranged 0.45-3.1 MPa, the maximum pressure difference in the engine is about 0.7 MPa and the temperature ranged 282-709 K. For the metal in the regenerator, the temperature distribution is linear and the effectiveness of the regenerator is 83.87%. The power output from the engine is 9.85 kW and the thermal efficiency is 33.85%. Rotational frequency is 852 rpm. Solar collector receives radiation area is approximately 32.4 m2. When the regenerator heat transfer coefficient using Kelly and McLand (2007) correlation in high radiation intensity 830 W/m2 and the total mass of the working fluid of the engine are 18.16,27.26 and 36.32 g, engine output power are 7.89,8.42 and 8.4 kW. The radiation intensity and the total mass of 670 W/m2, respectively 27.26 and 36.32 g, engine output power are 7.37 and 7.4 kW. If regenerator heat transfer coefficient using Gedeon and Wood (1996) the correlation at high radiation intensity and total mass are 18.16,27.26 and 36.32 g, the engine output power, respectively 7.88,8.22 and 8.21 kW. Under the radiation intensity, and the total mass are 27.26 and 36.32 g, engine output power are 7.2 and 7.24 kW. In the low radiation intensity 560 W/m2, the energy is too low to drive the engine rotation. |