Development of a Low-Energy Nanosecond Pulsed Ignition System Enabling High-Efficiency Dilute Gasoline Combustion

The DOE’s mission includes helping maximize the benefit and value of America’s petroleum resources while minimizing potential impacts on the environment and human health.Highway vehicles in the U.S.produce 11.6 billion lbs.of NOx and 400 million lbs.of particulates resulting in 22,000 deaths/year12.Even with the projected growth in electric vehicle purchases, our auto industry expects more than 90 million new registrations of combustion engine vehicles by 20303.The industry needs advanced combustion strategies such as dilute-burn engines to enable more energy efficient and environmentally-friendly passenger vehicles; however, ignition instability is often the limiting factor4.In Phase I, we demonstrated a lowenergy low-temperature plasma ignition system that could propel dilute-burn engines into the market thereby reducing NOx emissions over 50% while generating fuel savings of up to $80 billion/year.In this Phase IIB, Transient Plasma Systems will follow up on work completed in Phase II to demonstrate extended spark plug lifetime, a critical metric to automakers evaluating advanced ignition techniques.The ignition system has the potential to operate in a “sparkless” regime which would extend spark plug lifetime by minimizing erosion.The work in Phase II developed part of a solution to this critical erosion problem for both heavy-duty natural gas and gasoline engine manufacturers (e.g.Ford, Caterpillar, etc.).In Phase II, a control system based on a feedback loop to avoid spark breakdown.This was the first time that a control system had been developed for a nanosecond pulsed ignition system to avoid spark breakdown and minimize energy delivered to the spark plug while optimizing combustion performance.However, the final engine test revealed this approach was only part of the needed solution.There are three approaches we are exploring to achieve “sparkless” operation: 1.Active control - detection and avoidance through closed loop control system (Phase II) 2.Electrode design – dielectric barrier discharge (Phase IIB) 3.Alternate ignition strategy – new pulse delivery strategy (Phase IIB) Using Phase IIB support and a combination of these techniques, we intend to meet the automakers demand for spark plug service interval 2X greater than other high-energy thermal ignition systems.As context, in stationary power generation, engines are taken out of service to change spark plugs every 16 weeks at a cost of over $10K/hour.Existing relationships with engine research facilities and engine manufacturers will provide additional financial support and expertise as we develop and optimize the ignition system to meet market needs.The result will be the demonstration of an ignition approach that addresses the needs and concerns of automotive and heavy-duty manufacturers and Tier 1 suppliers, enabling them to realize groundbreaking efficiencies with streamlined maintenance in the next generation of internal combustion engines.