0
Research Papers: Gas Turbines: Combustion, Fuels, and Emissions

Controlled SSCI With Moderate End-Gas Auto-Ignition for Fuel Economy Improvement and Knock Suppression

[+] Author and Article Information
Hui Liu

State Key Laboratory of Automotive
Safety and Energy,
Tsinghua University,
Beijing 100084, China
e-mail: liuhui_tsinghua@126.com

Zhi Wang

State Key Laboratory of Automotive
Safety and Energy,
Tsinghua University,
Beijing 100084, China
e-mail: wangzhi@tsinghua.edu.cn

Jianxin Wang

State Key Laboratory of Automotive
Safety and Energy,
Tsinghua University,
Beijing 100084, China
e-mail: wangjx@tsinghua.edu.cn

Mengke Wang

Chery Automobile Engineering
and Research Institute,
Anhui 241009, China
e-mail: wangmengke@mychery.com

Wanli Yang

Chery Automobile Engineering
and Research Institute,
Anhui 241009, China
e-mail: yangwanliwh@163.com

Contributed by the Combustion and Fuels Committee of ASME for publication in the JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER. Manuscript received March 1, 2015; final manuscript received March 16, 2015; published online April 8, 2015. Editor: David Wisler.

J. Eng. Gas Turbines Power 137(10), 101508 (Oct 01, 2015) (6 pages) Paper No: GTP-15-1069; doi: 10.1115/1.4030101 History: Received March 01, 2015; Revised March 16, 2015; Online April 08, 2015

Hybrid combustion mode including flame propagation induced by spark ignition (SI) and auto-ignition could be an effective method to improve fuel economy and suppress engine knock simultaneously. An experimental research on controlled spark-assisted stratified compression ignition (SSCI) for this purpose was conducted in a gasoline direct injection (GDI) engine with high compression ratio. At wide open throttle (WOT) and minimum spark advance for best torque (MBT) condition without turbocharging, direct injection was used to form desired stoichiometric stratified mixture while 20% cooled external exhaust gas recirculation (e-EGR) was sucked into the cylinder. The combustion characteristics of controlled SSCI show two-stage heat release, where the first stage is caused by SI and the second stage is due to moderate auto-ignition. Compared with engine knock, the second stage heat release of controlled SSCI shows smooth pressure curve without pressure oscillation. This is due to the low energy density mixture around the cylinder wall caused by cooled e-EGR. The stratified mixture could suppress knock. Fuel economy and combustion characteristics of the baseline and the controlled SSCI combustion were compared. The baseline GDI engine reaches a maximum of 8.9 bar brake mean effective pressure (BMEP) with brake specific fuel consumption (BSFC) of 291 g/(kWh), and the controlled SSCI combustion achieves a maximum of 8.3 bar BMEP with BSFC of 256 g/(kWh), improving the fuel economy over 12% while maintaining approximately the same power. The results show that controlled SSCI with two-stage heat releases is a potential combustion strategy to suppress engine knock while achieving high efficiency of the high compression ratio gasoline engine.

FIGURES IN THIS ARTICLE
<>
Copyright © 2015 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

Schematic of controlled SSCI with moderate auto-ignition combustion mode

Grahic Jump Location
Fig. 2

Diagram of the experimental setup

Grahic Jump Location
Fig. 3

Single injection knock-limit and two-stage injection maximum-load with a different EGR

Grahic Jump Location
Fig. 4

BSFC of single injection knock-limit and two-stage injection maximum-load with a different EGR

Grahic Jump Location
Fig. 5

CA50 of single injection knock-limit and two-stage injection maximum-load with a different EGR

Grahic Jump Location
Fig. 6

COV of single injection knock-limit and two-stage injection maximum-load with a different EGR

Grahic Jump Location
Fig. 7

Cylinder pressure and heat release rate of single injection knock-limit without EGR and two-stage injection maximum-load with 20% EGR

Grahic Jump Location
Fig. 8

Combustion phase of baseline, single injection knock-limit without EGR and two-stage injection maximum-load with 20% EGR

Grahic Jump Location
Fig. 9

Pmax and PRRmax of baseline, single injection knock-limit without EGR and two-stage injection maximum-load with 20% EGR

Grahic Jump Location
Fig. 10

APmax and APRRmax of baseline, single injection knock-limit without EGR and two-stage injection maximum-load with 20% EGR

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In