Open Access

ARTICLE

A Study of the Effect of the Miller Cycle on the Combustion of a Supercharged Marine Diesel Engine

Lingjie Zhao, Cong Li^*

Mechanical and Automotive Engineering School, Shanghai University of Engineering Science, Shanghai, 201600, China

* Corresponding Author: Cong Li. Email:

Energy Engineering 2024, 121(5), 1363-1380. https://doi.org/10.32604/ee.2024.046918

Received 19 October 2023; Accepted 28 December 2023; Issue published 30 April 2024

Abstract

The Miller cycle is a program that effectively reduces NO_x emissions from marine diesel engines by lowering the maximum combustion temperature in the cylinder, thereby reducing NO_x emissions. To effectively investigate the impact of Miller cycle optimum combustion performance and emission capability under high load conditions, this study will perform a one-dimensional simulation of the performance of a marine diesel engine, as well as a three-dimensional simulation of the combustion in the cylinder. A 6-cylinder four-stroke single-stage supercharged diesel engine is taken as the research object. The chassis dynamometer and other related equipment are used to build the test system, carry out the diesel engine bench test, and collect experimental data. The simulation results are compared with the test results, and the error is less than 5%. In this study, the authors will use simulation software to simulate several Miller cycle scenarios designed for early inlet valve closure and analyze the impact of the Miller cycle on combustion and emissions at 100% load conditions. By comparing the flow field distribution of the engine at 1500 r/min condition, it was found that proper EIVC can prolong the ignition latency period and homogeneous fuel-air mixture combustion acceleration, but it can reduce pressure and temperature within the piston chamber and NO_x emission. However, the Miller cycle reduces end-of-compression temperatures, which increases combustion duration and exhaust temperatures, making it difficult to improve fuel economy at the optimum fuel consumption point, and closing the intake valves prematurely leads to excessive fuel expenditure. Furthermore, temperature and heat release rate within the piston chamber, NO_x, and SOOT generation were significantly enhanced.

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Keywords

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