Research of Advanced Spark Ignited Prechambers Utilizing Turbulent Jet Ignition
Improving performance and efficiency for heavy-duty natural gas vehicles with advanced ignition systems.
Olson-Ecologic Engine Testing Laboratories, LLC
Recipient
Fullerton, CA
Recipient Location
29th
Senate District
67th
Assembly District
$749,879
Amount Spent
Completed
Project Status
Project Result
Project results show potential for further research and potential commercialization in some markets. However, additional research is needed to address emission issues found during testing and to test on the lean-burn configuration. Additionally, since testing has been limited to steady-state cycles, the electronic control module calibration needs to be expanded to address transient testing.
The Issue
The low fuel cost and efforts to reduce both criteria emissions and greenhouse gases are incentivizing the transition to natural gas as a transportation fuel in heavy duty on-road applications. Basic conversion of an engine from diesel to natural gas typically results in a reduction of available power and thermal efficiency of over 30%. Operating at higher dilution levels will allow higher engine output and fuel efficiencies but also increases the demands on the ignition system. Additional research is needed to improve ignition systems in natural gas engines to address these issues and improve engine efficiency.
Project Innovation
Olson Ecologic used turbulent jet prechambers to ignite natural gas engines as a means of overcoming some current natural gas ignition challenges. The Olson Ecologic team demonstrated that its prototype engine can be ignited with an air to fuel ratio double the current practice (dilute) while satisfying tighter emission standards and achieving the lower fuel consumption rates.[br/][br/]The Olson EcoLogic team explored the use of prechambers which ignite the fuel outside but adjacent to the main chamber. Gases ignited in the prechamber are instantly conveyed by turbulent jets to foster rapid combustion in the main chamber. The team evaluated two ignition scenarios. The first scenario involved the high boost pressure from the turbocharger with heavy exhaust gas recirculation. The second scenario high boost pressure with high rates of dilution air.
Project Goals
Project Benefits
Through this project and the utilization of a turbulent jet ignition system in a Navistar 7 liter engine, this project targeted a 90 percent reduction and 80 percent reduction in NOx emissions by developing several configurations suitable for heavy-duty vehicles.
Consumer Appeal
This technology has the potential to be advantageous for repowering off road applications to lean CNG with fueled prechambers. It is an attractive option for construction fleet owners who may be faced with more expensive options to repower diesel engines or replace their machines to meet the CARB compliance deadlines. According to Omnitek, the commercialized cost of repowering an existing machine, such as a 966G Loader with a 9 liter engine, to the fueled turbulent jet prototype engine, aftertreatment and CNG storage tanks is $105,000. The lean application of this engine is deemed attractive for commercial development because of fuel efficiency benefits and lower exhaust temperature.
Reliability
Although lean operations normally mean sacrifice of power, the test engines met full power of 300 horsepower at dilute levels of 1.8 with the turbulent jet prechambers. High boost pressure was sustained and good fuel efficiency was also observed.
Key Project Members
Michael Naylor
Subrecipients
Michigan State University
Omnitek Engineering Corporation
Rail Propulsion Systems
Match Partners
Olson-Ecologic Engine Testing Laboratories, LLC
Rail Propulsion Systems
