Numerical investigation of SOC timing effects on performance and emissions of a high-compression diesel engine converted to LPG spark-ignition

Abstract

Rising environmental concerns and the depletion of fossil fuels increase the research into the use of alternative fuels in engines with minimal structural modifications. Liquefied petroleum gas (LPG) is a promising alternative due to its high octane rating and low carbon content. In this research, a high-compression diesel engine was converted to a spark-ignition (SI) engine fueled with LPG using 0/1 D numerical modeling with AVL Cruise M software. The model was validated with experimental data of the diesel regime. Applications with LPG are typically conducted at low compression ratios, and in this study, the conversion effects were investigated in a high-compression (17.5:1) engine. The parametric effects of start of combustion (SOC) timing on combustion characteristics, performance, and emissions were investigated.The converted LPG engine demonstrated approximately 13.7% higher power and 4.7% higher efficiency compared to the diesel regime. Delaying SOC from +0°CA ATDC to +15°CA ATDC reduced NOₓ by 79% but increased CO by 46%.

Keywords

• LPG engine
• Spark ignition
• Combustion timing
• Emissions
• AVL Cruise

Kaynakça

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