Computational Study on the Combustion and Emissions Characteristics of a HCCI Engine Fueled with Natural Gas

다국어 초록 (Multilingual Abstract)

This study was computationally investigated the combustion and emissions characteristics of HCCI engine fueled with natural gas. CHEMKIN-PRO was used to perform the numerical analysis. In an HCCI engine, the autoignition does not always mean the high combustion efficiency because the operating ranges to achieve high combustion efficiency is very narrowly restricted by knocking and high THC, CO emissions. In this study, we were investigated the effects of intake temperature, equivalence ration and engine speed for extending the operating range in HCCI engine fueled with natural gas to confirm the mechanism of autoignition reactions. Also studying on the influences of equivalence ration, intake temperature, engine speed on the operating range, combustion efficiency, CO, CO₂, THC,Nox and chemical species. To set boundary of operating range, intake temperature was varied from 380K to 470K with increment of 10K. While equivalence ration was changed from 0.0 to 08 with increment of 0.1(the knocking was occurred over than 0.7). The autoignition of natural gas occurs when in cylinder gas temperature reaches to 1110±30K under these calculation conditions. It is shown the combustion efficiency is around 90%, and THC and HC emissions were degreased. The CO emission was oxidized to CO₂completely, when the in-cylinder gas temperature around 1900K.

목차 (Table of Contents)

• Abstract
• 1. INTRODUCTION
• 2. CALCULATION METHOD
• 3. RESULTS
• 4. CONCLUSION
• References