Ignition Assist Systems for Direct-Injected Diesel Cycle, Medium-Duty Alternative Fuel Engines: Final Report Phase I

This report is a summary of the results of Phase 1 of this contract. The objective was to evaluate the potential of assist technologies for direct-injected alternative fuel engines vs. glow plug ignition assist. The goal was to demonstrate the feasibility of an ignition system life of 10,000 hours and a system cost of less than 50% of the glow plug system, while meeting or exceeding the enginethermal efficiency obtained with the glow plug system. There were three tasks in Phase 1. Under Task 1, a comprehensive review of feasible ignition options for DING engines was completed. The most promising options are: 1) AC and the 'SmartFire' spark, which are both long-duration, low-power (LDLP) spark systems; 2) the short-duration, high-power (SDHP) spark system; 3) the micropilot injectionignition; and 4) the stratified charge plasma ignition. Efforts concentrated on investigating the AC spark, 'SmartFire' spark, and short-duration/high-power spark systems. Using our proprietary pricing information, we predicted that the commercial costs for the AC spark, the short-duration/high-power spark and 'SmartFire' spark systems will be comparable (if not less) to the glow plug system.Task 2 involved designing and performing bench tests to determine the criteria for the ignition system and the prototype spark plug for Task 3. The two most important design criteria are the high voltage output requirement of the ignition system and the minimum electrical insulation requirement for the spark plug. Under Task 3, all the necessary hardware for the one-cylinder engine test wasdesigned. The hardware includes modified 3126 cylinder heads, specially designed prototype spark plugs, ignition system electronics, and parts for the system installation. Two 3126 cylinder heads and the 'SmartFire' ignition system were procured, and testing will begin in Phase 2 of this subcontract.