A study of smart thermal insulation coating on improving thermal efficiency in a marine two-stroke low-speed diesel engine

Fuel ◽  
2021 ◽  
Vol 304 ◽  
pp. 120760
Author(s):  
Jiale Cao ◽  
Tie Li ◽  
Xinyi Zhou
Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 417
Author(s):  
Xingyu Liang ◽  
Ziyang Liu ◽  
Kun Wang ◽  
Xiaohui Wang ◽  
Zhijie Zhu ◽  
...  

Low-speed two-stroke marine diesel engines dominate the modern global long-distance transportation market; with the increasingly stringent regulations, the combustion and emissions of these engines is gaining intense interest. The primary objective of the present study was to understand the effects of air-fuel mixing by pilot injection strategy on the combustion and emission characteristics of the marine diesel engines through a numerical study. Specifically, a computational fluid dynamic (CFD) model was established and validated by experimental data for a typical low-speed two-stroke marine diesel engine. The combustion parameters under different stages were analyzed, including mean in-cylinder temperature and pressure, indicated thermal efficiency (ITE), indicated specific fuel consumption (ISFC), and distribution of fuel-air mixture. Results indicated that, due to the premixing effect, the pilot injection produced unburned soot from the main injection’s ignition as well as decrease the intervals between the middle and final stages of combustion, thus raising the in-cylinder temperature. The interaction between the reduction of soot particles resulted from the increased temperature, and the decrease of the stage intervals led to lower overall boundary heat loss, which improved the effective thermal efficiency. The pilot injection timing and quality, respectively, showed quadratic and linear impact modes on engine performance and emissions.


2021 ◽  
Vol 1068 (1) ◽  
pp. 012016
Author(s):  
Hazim Sharudin ◽  
N.A. Rahim ◽  
N.I. Ismail ◽  
Sharzali Che Mat ◽  
Nik Rosli Abdullah ◽  
...  

2001 ◽  
Vol 32 ◽  
pp. 77-78
Author(s):  
J.J. RODRIGUEZ-MAROTO ◽  
D. SANZ-RIVERA ◽  
J.L. DORRONSORO ◽  
F.J. GOMEZ-MORENO ◽  
R. MUÑOZ-BUENO ◽  
...  
Keyword(s):  

2016 ◽  
Vol 51 (2) ◽  
pp. 153-158
Author(s):  
Takahira Tabuchi ◽  
Takashi Fuchikami ◽  
Kouichi Namba ◽  
Yutaro Wada ◽  
Yasuyuki Tsuji
Keyword(s):  

2017 ◽  
Author(s):  
Michal Kopčok ◽  
Jozefa Lukovičová ◽  
Jozef Kačur ◽  
Gabriela Pavlendová

2020 ◽  
Vol 12 (12) ◽  
pp. 168781402098462
Author(s):  
Yingying Lu ◽  
Yize Liu

Advanced multiple injection strategies have been suggested for compression ignition engines in order to meet the increasingly stringent emission regulations. Experiments and simulations were used to study effects of the main-injection mode (times), the post-injection proportion, and timing on combustion and emissions in a heavy-duty diesel engine at high load and constant low speed. The results reveal the following. The NOx emissions of 1main+1post, 2main+1post, and 3main+1post injections are all lower than those of single injection; the higher the number of main-injection pluses, the lower the NOx emissions. Enough main-post injection interval is needed to ensure post and main injections are relatively independent to entrain more fresh air to decrease the soot. Over-retarded post-injection timing tends to increase the soot due to the lower in-cylinder temperature. The combined effects of formation and oxidation determine the final soot. To gain the best trade-off of NOx and soot, compared with single injection, for the three multiple injections, the lowest soot emissions are gained at post-injection proportions of 15% and post-injection timings of 25°, 30°, and 35° CA ATDC, with soot reductions of 26.7%, −34.5%, and −112.8%, and NOx reductions of 5.88%, 21.2%, and 40.3%, respectively, for 1main+1post, 2main+1post, and 3main+1post injections.


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