Characteristics of Controlled Auto Ignition combustion with respect to the Reforming ratio of Gasoline fuel

다국어 초록 (Multilingual Abstract)

As a technique for the improvement of fuel economy and the reduction of NOx emission in Spark Ignition (SI) engine, Controlled Auto Ignition (CAI) combustion has been studied steadily. CAI combustion has two disadvantages; operational range of CAI combustion is so narrow that the range could not cover all of engine operating conditions and combustion phase is hard to be controlled. To expand operational range of stable CAI combustion and control combustion phase easily, a technique of reforming gasoline fuel with the method of Partial Oxidation (POx) reaction was applied to CAI combustion. Hot Gas Generator (HGG) which reforms gasoline fuel with a POx catalyst was designed to supply reformed gas, i.e., hydrogen rich gas to the intake port of the engine.
In this study, the reforming ratio of the supplied reformed gasoline quantity to the total supplied gasoline quantity was defined to see the effects of the hot reformed gas produced by HGG on CAI combustion. The single cylinder engine equipped Variable Valve Timing (VVT) device was experimented from 0 % (not reformed) to 100 % (all reformed) of the reforming ratio by an interval of 20 % at 1600 rpm with Negative Valve Overlap (NVO) strategy. As a result, stabilization of CAI combustion is improved by the supply of the reformed gas to the intake port. Furthermore, operational range of CAI combustion is enlarged. Combustion phase, fuel conversion efficiency, and emission characteristics are also examined and compared with those of conventional SI engine.

목차 (Table of Contents)

• Abstract
• 1. INTRODUCTION
• 2. EXPERIMENTAL SETUP AND METHOD
• 3. EXPERIMENTAL RESULTS
• 4. CONCLUSION
• References