Variable Valve Actuation Strategies for Better Efficiency Load Range and Thermal Management in an RCCI Engine

The Reactivity Controlled Compression Ignition concept for dual-fuel engines has multiple challenges of which some can be overcome using Variable Valve Actuation approaches. For various fuel combinations, the engine research community has shown that running dual-fuel engines in RCCI mode, improves thermal efficiency and results in ultra-low engine-out nitrous oxides and soot. However, stable RCCI combustion is limited to a certain load range, depending on available hardware. At low loads, the combustion efficiency can drop significantly, whereas at high loads, the maximum in-cylinder pressure can easily exceed the engine design limit. In this paper, three VVA measures to increase load range, improve combustion efficiency, and perform thermal management are presented. Simulation results are used to demonstrate the potential of these VVA measures for a heavy-duty engine running on natural gas and diesel. First, TNO’s multi-zonal combustion model is introduced and validated using experimental data from a multi-cylinder heavy-duty engine operated in RCCI mode with variable intake timing. This combustion model is used in conjunction with a commercial zero-dimensional engine simulation tool to examine three different VVA strategies, each with its own advantage: The latter two are especially important for dual-fuel engines using natural gas since they offer an effective means for CH4 slip reduction. It is shown that thanks to these measures, a heavy-duty engine can run with natural gas - diesel RCCI in the full load range and that significant CH4 reduction towards Euro VI limits is possible. The paper is concluded with an outlook on options to achieve these goals successfully on a real engine.

• Record URL:
  • https://doi.org/10.4271/2018-01-0254
• 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:
  • Mikulski, Maciej
  • Balakrishnan, Praveen Ramanujam
  • Doosje, Erik
  • Bekdemir, Cemil
• Conference:
  • WCX World Congress Experience
  • Location: Detroit Michigan, United States
  • Date: 2018-4-10 to 2018-4-12
• Publication Date: 2018-4-3

Language

• English

Media Info

• Media Type: Web
• Features: Figures; References; Tables;
• 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: Combustion; Compression ignition engines; Diesel engines; Engine efficiency; Exhaust valves; Methane; Natural gas; Simulation
• Subject Areas: Energy; Environment; Highways; Vehicles and Equipment;

Filing Info

• Accession Number: 01716122
• Record Type: Publication
• Source Agency: SAE International
• Report/Paper Numbers: 2018-01-0254
• Files: TRIS, SAE
• Created Date: Sep 13 2019 9:44AM