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http://dx.doi.org/10.3795/KSME-B.2015.39.1.045

Effects of Intake and Exhaust Valve Timing on Combustion and Emission Characteristics of Lean-Burn Direct-Injection LPG Engine  

Park, Cheolwoong (Korea Institute of Machinery and Materials)
Kim, Taeyoung (Korea Institute of Machinery and Materials)
Cho, Seehyoen (Dept. of Mechanical Engineering, Gachon Univ.)
Oh, Seungmook (Korea Institute of Machinery and Materials)
Publication Information
Transactions of the Korean Society of Mechanical Engineers B / v.39, no.1, 2015 , pp. 45-51 More about this Journal
Abstract
In order to meet the enforced emission regulations and reduce fuel consumption, various new technologies are employed in engines. The problem of NOx emissions under a lean mixture condition should be solved, because a lean-burn direct-injection engine can realize stable lean combustion with a stratified mixture, which results in improvements in fuel economy and emissions. This study investigated the effects of intake and exhaust valve timing changes on the performance and emission characteristics of a lean-burn LPG direct-injection engine. Under a partial-load operating condition without throttling, an increase in the intake valve opening led to an increase in NOx emissions due to an increase in the amount of excess air. The fuel consumption deteriorated with an increase in the exhaust valve opening due to a decrease in the expansion work and an increase in the pumping loss.
Keywords
Lean-burn Direct Injection Engine; Valve Timing; Throttling; Fuel Consumption; Emission Characteristics; Residual Gas; Excess Air Ratio;
Citations & Related Records
Times Cited By KSCI : 3  (Citation Analysis)
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