Comparison of Fuel Economy Improvement by High and Low Pressure EGR System on a Downsized Boosted Gasoline Engine

In this paper comparisons were made between the fuel economy improvement between a High Pressure loop (HP) water-cooled Exhaust Gas Recirculation (EGR) system and a Low Pressure loop (LP) water-cooled EGR system. Experiments were implemented on a 1.3-Litre turbocharged PFI gasoline engine in two pars. One was EGR rate as single operating point to compare the different effect of HP- and LP-EGR. The other was mini map from 1500rpm to 3000rpm and BMEP from 2bar to 14bar because of the relative narrow available range of HP-EGR system. In consideration of practical application of EGR system, the coolant used in this experiment was kept almost the same temperature as in real vehicles (88±3°C) instead of underground water temperature, besides a model was built to calculate constant volume ratio (CVR). The results indicated that the effect of HP-EGR was weaker than that of LP-EGR under the same EGR rate, which could be seen from change of combustion parameters. In mini map HP-EGR usually got higher best EGR rates for fuel economy at low-load region, and a better improvement (up to 2.96%) of fuel economy was expected. In contrast at moderate-to-high loads, especially at low speed high load region, HP-EGR rates were severely constrained by the application of turbo. So the application range of HP-EGR and LP-EGR was also compared in this paper. Thus at these regions worse fuel economy improvements compared with LP-EGR were observed. And cylinder-to-cylinder variations of combustion parameters of HP-EGR, for example IMEP, were wider than those of LP-EGR mainly for the non-uniform mixture of fresh working fluid and exhaust gas.

• Record URL:
  https://doi.org/10.4271/2017-01-0682
• 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:
  • Chao, Yuedong
  • Lu, Haifeng
  • Hu, Zongjie
  • Deng, Jun
  • Wu, Zhijun
  • Li, Liguang
  • Shen, Yuan
  • Yuan, Shuang
• Conference:
  • WCX™ 17: SAE World Congress Experience
  • Location: Detroit Michigan, United States
  • Date: 2017-4-4 to 2017-4-6
• Publication Date: 2017-3-28

Language

• English

Media Info

• Media Type: Web
• Features: Figures; 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: Exhaust gas recirculation; Fuel consumption; Gasoline engines; Motor vehicles; Pressure; Spark ignition engines
• Subject Areas: Energy; Highways; Vehicles and Equipment;

Filing Info

• Accession Number: 01657218
• Record Type: Publication
• Source Agency: SAE International
• Report/Paper Numbers: 2017-01-0682
• Files: TRIS, SAE
• Created Date: Jan 24 2018 9:11AM