The Journal of Engine Research

The Journal of Engine Research

Conceptual and experimental study of an Atkinson cycle engine of a Series-Parallel hybrid ‎electric vehicle

Document Type : Original Article

Authors
Irankhodro Powertrain Company (IPCO), Tehran, Iran
Abstract
The Atkinson cycle engine plays a crucial role in advancing Hybrid Electric Vehicles (HEVs) due to its superior fuel efficiency compared to the Otto cycle engine. Thermodynamic analysis highlights the Atkinson cycle's significant advantage in cycle efficiency, with factors such as the expansion ratio and effective compression ratio, influencing overall efficiency. This investigation focuses on converting an Otto cycle engine to an Atkinson cycle engine by implementing late intake valve closing and increasing the compression ratio. The optimization of the high geometric compression ratio from 10.7 to 12.4 aims to overcome the Atkinson cycle's drawback, where combustion performance deteriorates due to a reduction in the effective compression ratio. GT-Power software is used to simulate engine performance under various operating points, and comprehensive experiments are conducted to determine the performance, fuel consumption, and combustion characteristics of the developed Atkinson engine. Experimental results show that the Atkinson cycle engine exhibits substantially lower overall fuel consumption compared to the Otto cycle engine, with an improvement in maximum thermal efficiency from 34% to 34.6%. Additionally, the fuel-efficient range of the Atkinson cycle engine surpasses that of the Otto cycle engine, with the minimum fuel consumption area now occurring at low-medium speed and medium-high-load operational conditions.
Keywords

[1] Niu Q, Sun B, Zhang D, Luo Q. Research on performance optimization and fuel-saving mechanism of an Atkinson cycle gasoline engine at low speed and part load. Fuel. 2020 Apr 1;265:117010. doi: 10.1016/j.fuel.2020.117010
[2] Feng R, Li Y, Yang J, Jianqin FU, Zhang D, Zheng G. Investigations of Atkinson cycle converted from conventional Otto cycle gasoline engine. SAE Technical Paper; 2016 Apr 5. doi: 10.4271/2016-01-0680
[3] Wang C, Daniel R, Xu H. Research of the Atkinson cycle in the spark ignition engine. SAE Technical Paper; 2012 Apr 16. doi: 10.4271/2012-01-0390
[4] Atkinson J. “Atkinson engine.” US patent 367496, 1887.
[5] Adachi S, Hagihara H. The renewed 4-cylinder engine series for Toyota hybrid system.
[6] Takahashi D, Nakata K, Yoshihara Y, Ohta Y, Nishiura H. Combustion development to achieve engine thermal efficiency of 40% for hybrid vehicles. SAE Technical Paper; 2015 Apr 14. doi: 10.4271/2015-01-1254
[7] Akihisa D, Daisaku S. Research on improving thermal efficiency through variable super-high expansion ratio cycle. SAE Technical Paper; 2010 Apr 12.  doi: 10.4271/2010-01-0174
[8] Martins JJ, Uzuneanu K, Ribeiro BS, Jasansky O. Thermodynamic analysis of an over-expanded engine. SAE transactions. 2004 Jan 1:476-90.
[9] Hatano K, Iida K, Higashi H, Murata S. Development of a new multi-mode variable valve timing engine. SAE Transactions. 1993 Jan 1:1291-7.
[10] Tuttle JH. Controlling engine load by means of early intake-valve closing. SAE transactions. 1982 Jan 1:1648-62.
[11] Tuttle JH. Controlling engine load by means of late intake-valve closing. SAE transactions. 1980 Jan 1:2429-41.
[12] Li T, Gao Y, Wang J, Chen Z. The Miller cycle effects on improvement of fuel economy in a highly boosted, high compression ratio, direct-injection gasoline engine: EIVC vs. LIVC. Energy conversion and management. 2014 Mar 1;79:59-65. doi: 10.1016/j.enconman.2013.12.022
[13] Molina S, García A, Monsalve-Serrano J, Estepa D. Miller cycle for improved efficiency, load range and emissions in a heavy-duty engine running under reactivity controlled compression ignition combustion. Applied Thermal Engineering. 2018 May 25;136:161-8. doi: 10.1016/j.applthermaleng.2018.02.106
[14] Wei H, Shao A, Hua J, Zhou L, Feng D. Effects of applying a Miller cycle with split injection on engine performance and knock resistance in a downsized gasoline engine. Fuel. 2018 Feb 15;214:98-107. doi: 10.1016/j.fuel.2017.11.006
[15] Ellies B, Schenk C, Dekraker P. Benchmarking and Hardware-in-the-Loop Operation of a 2014 MAZDA SkyActiv 2.0 L 13: 1 Compression Ratio Engine. SAE Technical Paper; 2016 Apr 5. doi: 10.4271/2016-01-1007
[16] Jung HH, Stein RA, Leone TG. Comparison of dual retard VCT to continuously variable event valvetrain. SAE transactions. 2004 Jan 1:847-59.
[17] Jocsak J, White D, Armand C, Davis RS. Development of the combustion system for general motors' high-efficiency range extender ecotec small gas engine. SAE International Journal of Engines. 2015 Sep 1;8(4):1587-601.
[18] Toda T, Sakai M. The new Toyota inline 4-cylinder 2.5 L gasoline engine. SAE Technical Paper; 2017 Mar 28. doi: 10.4271/2017-01-1021
Volume 70, Issue 4 - Serial Number 73
English Paper
Winter 2024
Pages 69-80

  • Receive Date 02 April 2024
  • Revise Date 17 May 2024
  • Accept Date 24 May 2024