Researchers at Colorado State University will be working with natural gas experts at Cummins and Woodward with the goal of developing natural gas engines that are as efficient as diesel motors.
CSU’s Energy Institute received a $1.2 million grant from the U.S. Department of Energy which will be used to develop medium- and heavy-duty natural gas engines to more readily compete with diesel powerplants used in delivery and garbage trucks and tractor-trailers.
“Cummins is very excited to collaborate with Colorado State University and Woodward, Inc. in addressing some of the fundamental limitations to achieving diesel-like thermal efficiencies for medium- and heavy-duty on-road natural gas engines,” said Robin Bremmer, Cummins’ director of advanced alternative fuels & ignition systems research & technology.
“Cummins Westport natural gas engines have already set the bar very high for internal combustion engines by achieving near-zero NOx levels,” Bremmer added. “Providing our customers with a choice of engines that optimize their business model regardless of fuel-type remains very important to Cummins. Fuel efficiency and power density remain as important fundamental challenges to overcome for spark-ignited natural gas engines.”
Research at CSU could result in cost savings and improve air quality. Currently, natural gas is a cheaper and cleaner fuel than diesel. Natural gas engines emit fewer carbon dioxide emissions, less particulate matter and fewer oxides of nitrogen (NOx) that contribute to ground-level ozone and smog.
“We are excited to get to work alongside respected industry partners like Woodward and Cummins to advance natural gas engine technology,” said CSU Associate Professor Daniel Olsen who will be working on the project.
Cummins and Woodward have been working on natural gas engine problems for decades and will provide the team with hardware for testing and the capability to commercialize technology breakthroughs. Cummins is building a single-cylinder, 2.5-liter natural gas engine to be used as a key research tool for the project. Woodward is contributing combustion, ignition, fuel delivery technology and advanced engine controls.
The Energy Institute team is proposing to break down technological barriers, such as the knock and misfire limits, to optimize combustion and improve natural gas engine efficiency. The team plans to do this using a three-pronged approach. First, they will use a laser spark-ignited rapid compression machine (RCM), an experimental device that simulates a single compression stroke of an internal combustion engine, to study the chemical kinetics and combustion of natural gas. Second, they will use a Cooperative Fuel Research (CFR) engine to study how gas composition impacts end gas auto-ignition, the phenomenon that leads to engine knock.
Third, using lessons learned from the RCM and CFR engine studies, the team will develop engine models to direct the design of the combustion-related components in a specially built Cummins engine for final testing and system optimization. Woodward’s advanced combustion, fuel delivery and state-of-the-art combustion control technology will also play a role. These contributions will enable sustained operation of controlled auto-ignition, minimizing knock margin conservatism.
“The CSU [rapid compression machine] is a unique device to test the auto-ignition characteristics of the wide range of components found in natural gas and is able to simulate the components of recirculated exhaust gas for knock suppression,” said CSU associate professor Gregory Hampson, who is Woodward’s sponsor on this project. “This level of research in a wide range of fuels has not been done before, and it will help with engine design and control.”
The team is set to begin work on the three-year project this summer at the CSU Powerhouse Energy Campus.
“Collaboration works better here at the Powerhouse; it really is unique,” said Olsen, adding that the physical engine testing lab spaces make it an ideal place to do innovative group projects.
