空氣輔助噴嘴應用於半直接噴射系統之研究

Application of Air-assist Injector on Semi-direct Injection System.

高志豪(Chih-Hau Kao)

指導教授 ： 吳浴沂

國立臺北科技大學/機電學院/車輛工程系所/碩士(2008年)

摘要

本研究以高壓空氣提升傳統噴油嘴霧化效果，並使用高速攝影機拍攝以觀察噴束型態與霧化效果。在分接頭之測試中可了解當分接頭之管長與管徑增加時，空氣輔助噴嘴之霧化效果將會隨之降低。
在引擎實驗方面，加強進氣道渦流比至2.0及3.5，並配合空氣輔助噴嘴於進氣門開啟時噴油，將傳統進汽道噴射式汽油引擎改裝為半直接噴射系統，以提升稀薄燃燒極限，並降低引擎油耗，同時探討渦流強度及噴嘴霧化效果稀薄燃燒極限的影響。
實驗結果顯示，在進氣門開啟時噴油，並加強汽缸內渦流與噴嘴的霧化效果可提升引擎的稀薄燃燒極限。當進氣渦流加強至3.5並使用20 L/min的輔助空氣改善噴嘴霧化時，稀薄燃燒極限可從原引擎的17.1提升至23.7，並大幅提升制動馬力燃油消耗率以及降低循環變異。

關鍵字

空氣輔助 ； 渦流 ； 稀薄燃燒

並列摘要

In this paper, the compressed air is used to improve the atomization of traditional injector, then used high speed camera to observes the fuel spray pattern and the effect fuel atomization. Result shows the atomization will lower while tube diameter and tube length of the adaptor increase.
The modified intake manifold increases the swirl ratio to 2.032 and 3.5 at engine experiment. The combined air-assist injector makes the traditional PFI system into SDI system, and increasing the lean misfire limit and decreasing fuel consumption.
The experimental results show the lean limit increases by the fuel injection during intake valve opened, the swirl ratio and the fuel atomization also increase. The intake swirl ratio is increased to 3.5 and the air flow rate of assist air is 20 L/min. The atomization of injector is improved and the lean misfire air-fuel ratio limit is increased from 17.1 to 23.7. The break specific fuel consumption and coefficient of variation are reduced significantly.

並列關鍵字

Air-assist ； Swirl, ； Lean Burn

參考文獻

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