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In order to satisfy the single-fuel initiative, the US Armed Forces have need of man-portable electrical generation that will operate on JP-8 fuel. Previous conversions use diesel engines, which tend to be large and heavy - partially due to the high compression ratios necessary. This research shows the conversion process and performance of a low compression ratio gasoline genset for JP-8 operation. Central to this conversion was a catalytic plasma torch that replaces the conventional spark plug, and slight modifications to the fuel system. Comparisons between the stock gasoline genset and modified JP-8 genset are given for: power output, emissions, fuel flow, and efficiency. The tests were conducted in a cold chamber under 25 °C, 4 °C, and -10 °C conditions. The JP-8 conversion added minimal weight to the genset that can be started by hand with a pull cord.

As part of its single-fuel initiative, the US Armed Forces has a desire to operate all of their equipment on JP-8 fuel. Larger applications using diesel engines have been easy to convert, but small gasoline engine conversions have proven more difficult. This paper chronicles problems encountered, successful solutions, and lessons learned during the conversion of a carbureted 2kW Honda generator for use with JP-8 fuel. Cold-start, fuel delivery, load control, and auxiliary systems required significant adaptation. A catalytic plasma torch was used as the ignition source and similar technology was developed to support cold-starting at temperatures down to -40°C. Combustion chamber design and low octane number fuel made it necessary for multiple ignition sources. Load control and auxiliary systems were handled by a custom micro-controller that used RPM, generator output current, head temperature, and a knock sensor as inputs.

Lean ethanol-water/air mixtures have potential for reducing NOx and CO emissions in internal combustion engines. Igniting such mixtures is not possible with conventional ignition sources. An improved catalytic ignition source is being developed to aid in the combustion of aqueous ethanol. The operating principle is homogeneous charge compression ignition in a catalytic pre-chamber, followed by torch ignition of the main chamber. In this system, ignition timing can be adjusted by changing the length of the catalytic core element, the length of the pre-chamber, the diameter of the pre-chamber, and the electrical power supplied to the catalytic core element. A multi-zone energy balance model has been developed to understand ignition timing of ethanol-water mixtures. Model predictions agree with pressure versus crank angle data obtained from a 15 kW Yanmar diesel engine converted for catalytic operation on ethanol-water fuel.

Previous research using catalytic igniters and ethanol water fueled mixtures has shown potential for lowering CO and NOx emissions while increasing engine efficiency over conventional engine configurations. Catalytic ignition systems allow combustion initiation over a much wider range of stoichiometry and water composition than traditional spark ignition systems. The platform explored in this research is a transit van converted to operate on either gasoline or ethanol water fuel mixtures. Special attention was devoted to improve cold starting and installing additional on board sensors and equipment for future testing. System features include integration of a wide band oxygen sensor, state-of-the-art engine management system, exhaust gas temperature sampling using platinum thin film resistive temperature devices and variable voltage control of catalytic igniters using DC-DC boost converters.