New 1.5-Liter Hybrid Engine Development with High Brake Thermal Efficiency

The hybrid engines produced by most original equipment manufacturers (OEMs) have been modified to fit within the framework of conventional engine designs. Recently, Geely has introduced a new 1.5-liter (1.5L) inline four-cylinder (I4) TGDI engine, specifically designed to meet the requirements of its innovative, efficient, and intelligent hybrid powertrain architecture. This engine achieves an impressive brake thermal efficiency (BTE) of 44%, as well as high specific torque at 153 Nm/L and high specific power at 67 kW/L. To attain this superior performance, the following technical strategies were implemented: a high compression ratio, the robust Miller cycle, an extended piston stroke-to-bore ratio, an intake port optimized for high tumble, cooled exhaust gas recirculation (EGR), and an advanced high-energy ignition system. Among these, the middle four strategies, in conjunction with piston cooling jets and enhanced exhaust-side cooling, all contribute to improved in-cylinder combustion. This, in turn, effectively mitigates the potential for severe knock and pre-ignition issues that can arise from the high compression ratio. Moreover, reducing friction is a key factor in achieving the 44% BTE. When integrated into Geely’s plug-in hybrid system, this new engine results in a 5.1% decrease in fuel consumption under charge-sustaining conditions, as measured in the WLTC cycle, when compared to the previous-generation engine.

• Record URL:
  • https://doi.org/10.4271/2024-01-5107
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/01487191
• Supplemental Notes:
  • Abstract reprinted with permission of SAE International.
• Authors:
  • Li, Qiang
  • Liu, Yang
  • Zhang, Peiyi
  • Yan, Pingtao
  • Li, Hongzhou
  • Zhu, Yunfeng
  • Ji, Yan
  • Li, Minggui
  • Cui, Boyue
• Conference:
  • Automotive Technical Papers
  • Location: Warrendale Pennsylvania
  • Date: 2024-1-1
• Publication Date: 2024-11-29

Language

• English

Media Info

• Media Type: Web
• Features: References;
• Serial:
  • SAE Technical Paper
  • Publisher: Society of Automotive Engineers (SAE)
  • ISSN: 0148-7191
  • EISSN: 2688-3627
  • Serial URL: http://papers.sae.org/

Subject/Index Terms

• TRT Terms: Engine efficiency; Engines; Hybrid vehicles; Ignition systems
• Subject Areas: Highways; Vehicles and Equipment;

Filing Info

• Accession Number: 01939549
• Record Type: Publication
• Source Agency: SAE International
• Report/Paper Numbers: 2024-01-5107
• Files: TRIS, SAE
• Created Date: Dec 13 2024 11:52AM