Potentially game-changing research that could slash fuel costs and meet tough new environmental regulations in the shipping industry was recently unveiled at the China Maritime trade show in Hong Kong.
Dr. Fokion Egolfopoulos and Dr. Martin Gundersen, along with University of Southern California Viterbi postdoctoral researcher Dr. Dan Singleton, were invited speakers to China Maritime, a premier trade show event for the maritime industry held in Hong Kong in February.
The three researchers provided a status update on a fundamentally new approach to reducing harmful emissions and greenhouse gases, while also improving combustion efficiency in large two-stroke low-rpm marine diesel engines that power the bulk of the world's merchant ships. Their research is sponsored by Mr. Kenneth Koo, Chairman and CEO of Tai Chong Cheang Steamship Co. (TCC), in the TCC Institute for Emissions Reduction in Marine Diesel Engines (TIER-MDE).
Gundersen, an applied physicist, and Egolfopoulos, a mechanical engineer specialising in combustion processes and fuels, have teamed together in TIER-MDE since 2010. Their goal is to apply 'transient plasma', generated by high-voltage pulses applied over nanoseconds (known as 'nanosecond pulsed power'), to improve the ignition and combustion process.
'Transient plasma' refers to an electrical discharge in its formative phase. The time scales are determined by constraints imposed by the time of plasma-discharge formation, and are typically very short, in the order of nanoseconds. Their approach offers a potentially low-cost and lightweight technology that could be back-fitted into existing engines, and profoundly influence the design of future generations of more efficient engines.
Gundersen's Nano-Second Pulsed Power Group has been applying transient plasma for nearly 15 years to propulsion systems for automotive and aerospace applications. "We've found that it can improve combustion efficiency in internal combustion engines by causing the fuel to burn more completely," Gundersen noted. "We've published quite a few papers on our research in open sources."
The group is currently exploring implementation of transient plasma in several commercial diesel engines in collaboration at other institutions. If this phase of testing shows a successful 'scaling up' of findings first documented in a single-cylinder lab-scale engine, then they will proceed with installing a prototype transient plasma ignition system on a full-sized marine diesel engine.
Gundersen's postdoctoral research associate and former Ph.D. student Dr. Dan Singleton adds that "if we demonstrate that transient plasma can help burn bunker fuel in these engines more efficiently, then it will be possible to dial back the injectors to use less fuel per stroke. If we can use less fuel and burn it more completely, we will drive down harmful emissions and also drive down the amount of fuel used per day at sea." Singleton and his fellow research associates Jason Sanders and Andy Kuthi (Dr. Kuthi is Project Manager) are collaborators working on the project.
Egolfopoulos' Combustion and Fuels Research Lab has a great deal of experience in studying and improving combustion processes. Among their accomplishments is an ongoing study for the United States Air Force on the comparative combustibility and emissions of jet fuel blends, including up to fifty percent mixtures of jet fuel—bio fuel and jet fuel—synthetic fuel. This study became the basis for the Air Force certifying all of its aircraft types to fly on blended fuels of both types. Egolfopoulos is providing the scientific analysis that will show to what degree transient plasma assists the pressure ignition process in a marine Diesel engine. He notes that "before now we only know that bunker fuel burns, but we don't really know how it burns. We provide the science to show how it burns, and to what degree the transient plasma will assist the pressure ignition process to produce a more complete burn." Egolfopoulos notes with a tone of realism "if this were easy, someone would have figured it out a long time ago. Instead we apply the scientific method and we learn a little and adjust with each experiment."
"You can't invent the physics of combustion, all you can really do is try to figure out how it works, and how we might be able to help it along. That's where combustion science can add a lot of value. We will likely burn hydrocarbons for some time, so let's figure out how to burn them better."
Koo's Operations Officer at TCC, Captain Vinay Patwardhan, notes "the other proposed solutions to the problem of emissions from marine diesel engines burning bunker fuels do not seem reasonable or obtainable. Transient plasma ignition may be our one best hope to meet the increasingly restrictive emissions standards imposed by regulators worldwide. If it works I hope they will welcome the technology."
Koo also noted "we really need to get transient plasma ignition technology to the world's merchant fleets as fast as possible. The survival of low-cost trans-oceanic shipping that enables the global exchange of goods and raw materials depends upon it, and we need to also do our part to minimize the impact of shipping on the environment."
If proved viable, transient plasma technology could lower fuel costs in two stroke diesel ships by as much as 30%, with a similar scale of reduced emissions.
Angus Mccoll
