Mixed & Multi-Fuel Internal Combustion Engines

SAE 2013 World Congress & Exhibition, April 16-18, 2013 Detroit, Michigan, USA Session # SDP110, Advances in Alternative Energy Sources for Sustainable Development in the Transportation Sector, Paper Offer Number: 13SDP-0003

Mixed & Multi-Fuel Internal Combustion Engines Christopher R. Hardy, Michael J. Myers, John Vetrovec Laser Spark Plug, Inc. 3 Cardinal Court # 215, Hilton Head Island, SC 29926 Ph# 843-298-5801, E-mail: [email protected] Abstract - Internal combustion engines typically burn either heavy fuel such as diesel, kerosene, JP5, JP8, Bio-Diesel, etc. or “light” fuels such as gasoline, ethanol or natural gas. Heavy fuel engines use the heat of compression to initiate ignition. Light fuel engines use a spark to initiate ignition. New mixed fuel (heavy & lite) engine technology allows for spark ignition of heavy and light fuel mixtures in any ratio. To our knowledge, this is the first commercial multi-fuelmixed fuel internal combustion engine. This presents a unique opportunity for the evaluation of conventional and alternative fuel mixtures in terms of efficiency, performance and emissions. Few (if any) studies report on spark ignition performance of a wide range of heavy and light fuel mixtures. This effort includes a test bed lightweight 2-stroke multi-fuel engine installed on a battery powered EZGO golf cart. The multi-mixed fuel engine powers a 36V electrical generator/battery charger. The golf cart and engine test bed will be used to evaluate the performance/efficiency (read miles/gallon) of spark ignited heavy and light fuel mixtures. Index of Terms: heavy fuel, light fuel, internal combustion, multi-fuel, fuel mixtures, spark ignition. Principal Author’s Biography: Christopher R. Hardy received a BS Electrical Engineering from the University of South Carolina Honors College in 1987. Mr. Hardy joined Kigre, Inc. in 1988 and became Chief Engineer in 1999. Mr. Hardy has worked on numerous IRD&E efforts and has been a Project Engineer and Principal Investigator on various Government programs. Mr. Hardy currently serves on the Industry Advisory Board for Georgia Southern University and is chair of the Savannah Section, IEEE. Mr. Hardy was appointed to the Board of Directors of Laser Spark Plug Inc. in 2007. Laser Spark Plug, Inc. is a 501(3)(c) non-profit organization that promotes the development of fuel efficient technologies for use in internal combustion engines.

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I. INTRODUCTION Electric vehicles need improvements to become successful market driven (mass produced) products. Compared to traditional vehicles, they are limited in range and functionality. In 2010, the US sales of 11.5 million new cars and trucks compares to only 275,000 hybrids and less than 20,000 electric vehicles [1,2]. New (heavy & lite) multi-fuel/mixed fuel engine technology provides an attractive option to increase range and functionality for hybrid and electric vehicles [3,4,5]. Novel light weight, low emission engines may serve as battery chargers or Auxiliary Power Units (APU) for electric cars. This allows for near unlimited range with the use of any fuel available. “Light” fuels include gasoline, methanol, ethanol, acetone, ether, nitro methane and alcohols. “Heavy” fuels include diesel, JP5, JP8, Jet A, kerosene, biodiesel, vegetable oils, seed oils, etc. Lightweight modified 2-stroke engine blocks are readily reconfigured with advanced materials for high durability and long life operation. A proprietary supercharger fuel injector system is installed that includes specially engineered micro-poppet valves. This unique injector system is designed to atomize the fuel into very small particles (with an extremely high surface to volume ratio) such that the fuel appears as a fine “smoke” instead of a traditional “spray”. The injector system projects and collimates the fuel smoke into the engine cylinder as a symmetrical “cloud” where two traditional spark-gap plugs are used for precision timed ignition resulting in unsurpassed engine performance with the cleanest burn and the greatest efficiency. II. MCDI ATOMIZATION TECHNOLOGY The Mechanically Compressed Direct Injection (MCDI) system combines air and fuel using a small compressor that is attached to each cylinder and injects the mixture into the combustion chamber through a delivery valve which finely atomizes the liquid to allow low evaporation types of fuels to ignite even at low temperatures [3,4]. The MCDI system also provides a high level of stratification of the charge through the delivery valve mechanism to eliminate detonation. The fuel is delivered into the piston chamber as very fine atomized or nebulized particles as shown in figure 1. The fuel appears as a fine smoke as the supercharged fuel injector poppet vales deliver a symmetrical “fuel cloud” instead of the more traditional fuel injector mist or spray. (figure 2) The system allows a high tolerance for the lightweight 2-stroke to burn nearly any liquid fuel available.

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Droplet Size (microns)

35

25 MCDI

Standard Injector

15

5 0.5

1

1.5

2

2.5

3

Normalized Fuel Shot Mass

Fig. 1 MCDI & standard system atomized fuel particle size comparison

Fig. 2 Super-charged fuel injector delivers symmetrical fine smoke fuel cloud

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The MCDI fuel delivery system provides for very clean burning of the fuel with low NOx emissions [5]. After many hours of operation these engines show extraordinary visible evidence of their efficient operation and low emissions. Figure 3 shows a 12 hp engine. Disassembled engine component parts (after extended operation under load) are shown in figures 4 and 5.

Fig. 3 12 hp lightweight two stroke engine with MCDI fuel delivery system

Fig. 4 Spark plugs and piston cylinder after extended operation under load

Fig. 5 Piston shaft engine/cylinder connections after extended operation under load

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III. MULTI-FUEL GENERATOR/APU TEST BED To our knowledge, there are very few (if any) studies on spark ignition performance of heavy and lite fuel mixtures. In fact, a few years ago we approached diesel engine research experts at the U.S. Army Aberdeen Test Center Support of Heavy Duty Diesel Engine Testing. We suggested testing spark ignition performance of heavy and lite fuel mixtures. They (5 different US Army diesel fuel experts) told us that it was impossible to spark ignite heavy fuel. In fact, the multi-fuel engine is being tested and under consideration for use in several military programs including Killer Bee and AAI’s RQ-7 Shadow [6,7]. These new UAV engines help to meet the U.S. Army’s “One Fuel Forward” initiative. We are in the process of assembling a test bed for the study of the efficiency performance for heavy and lite fuel mixtures. The test bed consists of a battery powered EZGO golf cart with a multiple fuel engine as a 36V electrical generator/battery charger. (Figure 6) The golf cart and engine will used to evaluate performance/efficiency (read miles/gallon) of spark ignited heavy and light fuel mixtures.

Fig. 6 Electric golf cart to be fitted with 36V XRDi multi/mix fuel engine battery charger

IV. CONCLUSION Lightweight (2-stroke) multi-fuel/mixed-fuel engines incorporating MCDI system technology holds promise to increase range and functionality for hybrid and electric vehicles. As an electrical generator, these engines provides for the burning of multiple fuels (i.e. diesel, kerosene, jet-A, JP5, JP8, and other fuels) in a low compression, spark-ignited engine with low emissions and significantly reduced fuel consumption levels. Technology advantages include multi-fuel capability, power/Weight ratio of >1 hp/lb, operating temperature Range -30 °C to +60 °C (tested), scalability, Low NOx emissions reduced from greater than 300ppm to less than 5


30ppm, low maintenance, operation on a variety of fuels with no recalibration (Bio-diesel, Ethanol, JP5, JP8, Jet A, diesel, gasoline) and cold start demonstrated at -30 °C (with no aids)[812]. This mixed fuel engine/generator electric golf cart research platform is initially slated for use by High School students as a test bed for science fair experiments. With successful future fundraising efforts, LSP plans to produce additional engine/golf cart test beds and make them available to engineering departments at Furman, USC and Clemson University International Center for Automotive Research (CU-ICAR). In the future, this same test bed may also be used to evaluate new (more practical) laser spark plug designs [13]. REFERENCES [1] “The Road Ahead” Automotive Industries Team report, U.S. Department of Commerce, 2011 [2] “2010‐2011 Investment Plan for the Alternative and renewable Fuel and vehicle Technology Program”, California Energy Commission, Committee Report, July 2010. [3] US Patent Number 6401674, “Multi-fuel engine”, June 11, 2002 [4] US Patent Number 6293232, “Multi-fuel engine”, September 25, 2001 [5] Energy & Environmental Analysis, Inc., “Advanced Microtubine System: Market Assessment”, Final Report to Oak Ridge National Lab, May 2003. [6] Matthew Monaghan, “Ricardo, NW UAV, and XRDi form alliance to provide UAV heavyfuel engine solutions”, SAE Vehicle Engineering Online, June, 19, 2011. [7] Green Car Congress, “Ricardo forms alliance with XRDi and NW UAV for UAV heavy-fuel engine solutions: Mechanically Compressed Direct Injection”, June, 1, 2011. [8] C. Haifeng, Z. Kaiding, D. Dan, L. Jiuliang, “Research on the Mixed Fuel of Diesel Ethanol and Lignin”, International Conference on Materials for Renewable Energy & Environment (ICMREE), Shanghai, P.R. China, pp.1176 – 1180, May, 2011. [9] J. Yuan-hua, W. Gui-fu, “The Research of Ethanol-Diesel Mixed Fuel Injection Supply System Based on Engine X195”, International Conference on Electric Technology and Civil Engineering (ICETCE), Lushan, P.R. China, pp. 6345 – 6347, April 2011.

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[10] Y. Li-hong, G. Yan, L. Wen-bin, W. Jiang, “Effects of the Mixture Fuel of Ethanol and Gasoline on Two-Stroke Engine”, International Conference on Intelligent Computation Technology and Automation (ICICTA), Changsha, P.R. China, pp. 188 – 191, May, 2010. [11] S. Jones, C. Peterson, “Using Unmodified Vegetable Oils as a Diesel Fuel Extender”, Literature Review, Department of Biological and Agricultural Engineering, University of Idaho, Moscow, Idaho, Dec. 1984. [12] Y. Ra, E. Hruby, R. Reitz, “Parametric Study of Combustion Characteristics in a DirectInjection Diesel Homogeneous Charge Compression Ignition Engine with a Low-Pressure Fuel Injector”, International Journal of Engine Research, Vol. 6, No. 3, pp. 215-230, June, 2005. [13] M. Tsunekane, T. Inohara, A. Ando, N. Kido, K. Kanehara and T. Taira, “High Peak power Passively Q-switched Microlaser for Ignition of Engines” IEEE, Journal of Quantum Electronics, VOL. 46, NO. 2, Feb. 2010.

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