Influence of Charge Motion and Compression Ratio on the Performance of a Combustion Concept Employing In-Cylinder Gasoline and Natural Gas Blending

Journal Article · Mon Aug 06 00:00:00 EDT 2018 · Journal of Engineering for Gas Turbines and Power

DOI:https://doi.org/10.1115/1.4040090· OSTI ID:1463678

Sevik, James ^[1]; Pamminger, Michael ^[2]; Wallner, Thomas ^[1]; Scarcelli, Riccardo ^[1]; Wooldridge, Steven ^[3]; Boyer, Brad ^[4]; Miers, Scott ^[5]; Hall, Carrie ^[2]

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1. Argonne National Lab. (ANL), Lemont, IL (United States)
2. Illinois Inst. of Technology, Chicago, IL (United States)
3. Ford Motor Company, Dearborn, MI (United States)
4. Ford Motor Company, Dearborn, MI (United States) 
5. Michigan Technological Univ., Houghton, MI (United States)

Here, the present paper represents a small piece of an extensive experimental effort investigating the dual-fuel operation of a light-duty spark ignited engine. Natural gas (NG) was directly injected into the cylinder and gasoline was injected into the intake-port. Direct injection (DI) of NG was used in order to overcome the power density loss usually experienced with NG port-fuel injection (PFI) as it allows an injection after intake valve closing. Having two separate fuel systems allows for a continuum of in-cylinder blend levels from pure gasoline to pure NG operation. The huge benefit of gasoline is its availability and energy density, whereas NG allows efficient operation at high load due to improved combustion phasing enabled by its higher knock resistance. Furthermore, using NG allowed a reduction of carbon dioxide emissions across the entire engine map due to the higher hydrogen-to-carbon ratio. Exhaust gas recirculation (EGR) was used to (a) increase efficiency at low and part-load operation and (b) reduce the propensity of knock at higher compression ratios (CRs) thereby enabling blend levels with greater amount of gasoline across a wider operating range. Two integral engine parameters, CR and incylinder turbulence levels, were varied in order to study their influence on efficiency, emissions, and performance over a specific speed and load range. Increasing the CR from 10.5 to 14.5 allowed an absolute increase in indicated thermal efficiency of more than 3% for 75% NG (25% gasoline) operation at 8 bar net indicated mean effective pressure (IMEP) and 2500 rpm. However, as anticipated, the achievable peak load at CR 14.5 with 100% gasoline was greatly reduced due to its lower knock resistance. The incylinder turbulence level was varied by means of tumble plates (TPs) as well as an insert for the NG injector that guides the injection “spray” to augment the tumble motion. The usage of TPs showed a significant increase in EGR dilution tolerance for pure gasoline operation, however, no such impact was found for blended operation of gasoline and NG.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Vehicle Technologies Office (EE-3V)
• Grant/Contract Number: AC02-06CH11357
• OSTI ID: 1463678
• Journal Information: Journal of Engineering for Gas Turbines and Power, Vol. 140, Issue 12; ISSN 0742-4795
• Publisher: ASME
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
Combustion
Fuels
Engines
Compression
Cylinders
Exhaust gas recirculation
Gasoline
Plates (structures)
Natural gas
Stress