Fuel Agnostic Combustion System for Energy Resilience, Operational Endurance, and Decarbonization of Naval Reciprocating Engines
Abstract
Project Summary Approved for Public ReleaseThe goal of this project is to develop an innovative fuel agnostic combustion system that will allow naval reciprocating engines that are designed to operate on F76 diesel fuel to be converted to use a wide range of fuels # such as F76, jet fuel, sustainable aviation fuel (SAF), methanol, hydrogen, ammonia, and others. The concept is prechamber enabled mixing-controlled combustion (PC-MCC) with a fuel reformer, which can maintain diesel engine operational characteristics and efficiency, such that there is no sacrifice in performance, while enabling fuel flexibility, operational endurance, and deep decarbonization when operating on lower carbon fuels.Prechamber Enabled Mixing-Controlled Combustion (PC-MCC) allows heavy-duty reciprocating engines to use low cetane fuels. The concept uses an actively fueled prechamber to ignite direct injected fuel, establishing a classic mixing-controlled combustion process. In the PC-MCC concept, the base engine is a conventional diesel engine, with the addition ofan actively fueled prechamber, which contains a fuel injector, spark plug, and small prechamber volume. Prechamber jet flames penetrate the main chamber and ignite the direct injected fuel, resulting in a mixing-controlled event, and the engine maintains the characteristics and efficiency of a diesel engine. One challenge with PC-MCC is heavier fuels, like F76 and jet fuels, which are lower volatility and thus don#t evaporate readily. This can lead to fuel wall wetting or spark plug fouling in the prechamber. It is imperative that a PC-MCC engine be developed that is backward compatible with F76 diesel fuel, but is also able to seamlessly use jet fuel, SAF, and methanol. Thus, the naval marine fleet can improve operational resilience while simultaneously decarbonizing.To address the challenge of fuel volatility in the prechamber with heavier fuels, a pressurized catalytic partial oxidation (CPOx) fuel reformerwill be used to convert the prechamber fuel to a gaseous mixture of lighter hydrocarbons, H2, and CO. The CPOx reformer will be feda fuel-rich mixture of pressurized air (~5 to 20 bar) and fuel. The CPOx has been demonstrated to deliver up to 85% reforming efficiency, high sulfur tolerance, and long life. Using this concept, reciprocating diesel engines can be converted to be truly fuel agnostic, and operate on any fuel, while maintaining engine performance and efficiency. This results in a marine propulsion system that has superior fuel flexibility, operational endurance, and the potential for deep decarbonization.The project team consists of Marquette University, the University of Wisconsin-Madison, and Precision Combustion, Inc. The team has a unique combination of expertise ranging from design, fabrication, simulation, testing, and product development that will be applied to evaluate the merits of the proposed concept as an enabler for the efficient use of renewable fuels in the Naval fleet.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 09, 2024
- Source ID
- N000142412685
Entities
People
- Adam Dempsey
Organizations
- Marquette University
- Office of Naval Research
- United States Navy