Experimental Study on Extension of the Lean Limit for Heavy-duty Direct Injection Natural Gas Engine with Spark Ignition

다국어 초록 (Multilingual Abstract)

The direct injection natural gas fueled engine with lean combustion and high power is well known as the new generation of lean combustion system. Nowadays, the emission standards and fuel consumption are tighter than so the new generation is must be more expended lean limit. It is mean that the new generated engine will be operated with ultra lean mixture stably. Authors are used some methods to expand lean limit as follow:
The rate of auxiliary intake fuel injection as a method to enhance the mixing duration, the lean limit is obtained λ = 1.53 but power is reduced rapidly. By the way the increased intake air is enhanced lean limit, it is due to supply energy and combustion rate are increased, although combustion temperature is decreased and power still increase. By the way the auxiliary intake fuel injection plus increase of intake air mass will be extended lean limit. This method may be achieved more ultra lean burn without low power and thermal efficiency. Until now, these results are not cleared.
In this study as early step in using the ultra lean mixtures so that the analysis data is focused on lean limit and engine performance. The experimental results show that increased boost pressure at 1.3 bar will be extended lean burn region to λ = 1.49 and high power.

목차 (Table of Contents)

• Abstract
• 1. INTRODUCTION
• 2. EXPERIMENTS AND METHODS
• 3. RESULTS AND DISCUSSIONS
• 4. CONCLUSION
• Acknowledgement
• References