運用液化石油氣於半直接噴射火花點火引擎之設計與控制

Design and Control of Semi-Direct Injection Spark Ignition Engine Fuelled by LPG

Tran anh trung(Tran anh trung)

指導教授 ： 吳浴沂 ； 陳柏全

國立臺北科技大學/機電學院/機電科技研究所/博士(2012年)

https://doi.org/10.6841/NTUT.2012.00021

摘要

為減少亞洲區域中大量機車所排放的廢氣，在本研究提出一機車引擎之稀薄燃燒系統與其控制策略，透過提升引擎效率及降低汙染排放的方式，來改善環境的空氣品質。本文中所採用的稀薄燃燒系統，係結合強烈進氣渦流、半直接噴射(semi-direct injection, SDI)及液化石油氣燃料等技術。藉由傳統機車氣道燃油噴射(port fuel injection, PFI)引擎進氣道修改並置入一可切換式檔片，能將汽缸內之渦旋比(swirl ratio)提升至0.958，且由於缸內紊流強度增強的關係，其引擎的稀油極限(lean-limit)將可提升至相對空燃比(relative air/fuel ratio, λ)1.7。機車引擎之稀薄燃燒控制策略，包含引擎管理系統(engine management system, EMS)、適應性進氣歧管壓力(pressure intake manifold, PIM)控制、層狀模式之適應性扭力控制、均質模式之適應性扭力控制及均質/層狀模式切換控制策略。
首先，傳統機車汽油引擎與稀薄燃燒系統之機車引擎將於低負載區域進行油耗與污染排放測試，其中包含了大多數ECE-40行車型態下之運轉點。實驗結果顯示，制動能量消耗率(brake-specific energy consumption, BSEC)可減少19.2%，CO2、NOX與CO的廢氣排放分別改善了27%、47%及94%，HC排放則增加4.5%。第二，機車引擎加上本研究提出之控制策略，由實驗結果顯示在均質/層狀模式切換時能有效的減少扭力顛簸。本研究提出之SDI引擎設計可以使機車在稀薄燃燒情況下運行，減少廢氣排放及油耗且機車仍維持高功率輸出。

關鍵字

機車 ； 汽油引擎 ； 層狀燃燒 ； 基於扭力式控制

並列摘要

Reducing motorcycle exhaust emissions to improve air quality is important in Asia due to the large number of motorcycles. This dissertation proposes a lean-burn system and lean-burn engine control strategies for improving motorcycle engine emissions and performance. The lean-burn system, called semi-direct injection (SDI), comprises high-swirl charge, injection during intake-valve opening, and liquefied petroleum gas (LPG) injection. A conventional motorcycle engine with port fuel injection (PFI) and spark ignition (SI) was retrofitted by designing a new intake port with a controllable plate to enhance the swirl of intake flow. The swirl ratio was increased to 0.958, enhancing turbulence of air flow inside the combustion chamber, and the lean limit was extended to 1.7 of relative air/fuel ratio (lambda). The proposed lean-burn engine control strategies consist of engine management system (EMS), adaptive pressure intake manifold (PIM) control, adaptive torque control in stratified mode, adaptive torque control in homogeneous mode, and switching strategies for switching between stratified and homogeneous mode.
First, engine was tested at low-load region which includes most operating points of the ECE-40 driving cycle. A complete engine performance map was conducted for comparison between the new design and regular gasoline engines. The results show that brake-specific energy consumption (BSEC) is decreased by 19.2%. Brake-specific exhaust emissions of CO2, NOx and CO were decreased by 27%, 47% and 94%, respectively. HC emissions were increased by 4.5%. Second, the experiments with the implementation of control strategies were performed, the results show that the proposed control strategies have good performance with small torque bumps in the switching mode. With this new design of SDI system, the motorcycle can be run with lean mixture and drastically reduce the exhaust emission and fuel consumption while still maintaining high specific power output.

並列關鍵字

Motorcycle ； Gasoline engine ； Stratified combustion ； Torque-based control

參考文獻

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