Argonne Devises New Variable Combustion Strategy for Hydrogen-Fueled Engines

14 March 2009

Researchers at the US Department of Energy’s Argonne National Laboratory’s Center for Transportation Research have devised new variable combustion strategy for hydrogen-fueled engines using the Lab’s Modular Automotive Technology Testbed (MATT).

As they put the engine through its paces, Argonne’s researchers evaluate the fuel economy and emissions generated by different combustion strategies. Argonne engineer Henning Lohse-Busch and his colleagues developed an optimal variable air-fuel ratio combustion strategy that allows a hydrogen internal combustion engine to run efficiently and cleanly in a conventional vehicle.

According to Lohse-Busch, these hydrogen-burning combustion engines represent the “bridging technology to the hydrogen economy.”

Due to the wide flammability range of hydrogen, a hydrogen engine can run at extremely high air-fuel ratios. All else being equal, the leanest combustion allows the engine to run efficiently and reduces NO_xemissions. However, the leaner combustion dramatically reduces the power output of the engine.

In his work on MATT, Lohse-Busch determined that by varying the air-hydrogen ratio, he could reduce the trade-off between fuel economy, low-NO_x emissions and power for these engines.

With a constant air-fuel ratio combustion strategy, you have to sacrifice fuel economy, high performance or low emissions. The variable combustion strategy that we developed for hydrogen engines resulted in the best fuel economy while achieving very low emissions even without an exhaust after-treatment system.

—Henning Lohse-Busch

In the future, researchers in the Center for Transportation Research hope to use MATT to marry the hydrogen-burning internal combustion engine with a hybrid propulsion system. This approach, Lohse-Busch explained, would enable Argonne researchers to reap more benefits from both technologies. “With the additional power supplied by a battery,” he said, “we can supply the hydrogen engine with leaner fuel streams, enabling the engine to run more efficiently and cleanly.”

Development and construction of MATT were funded by DOE’s Office of Energy Efficiency and Renewable Energy. Argonne researchers will present a paper on MATT at the upcoming SAE World Congress in Detroit in April.

Resources

• Thomas Wallner, Henning Lohse-Busch and Neeraj Shidorea (2008) Operating strategy for a hydrogen engine for improved drive-cycle efficiency and emissions behavior. International Journal of Hydrogen Energy doi:10.1016/j.ijhydene.2008.07.099

• Aymeric P. Rousseau, Thomas Wallner, Sylvain Pageri, Henning Lohse-Busch (2008) Prospects on Fuel Economy Improvements for Hydrogen Powered Vehicles. (SAE 2008-01-2378)

• Thomas Wallner, Abhijeet Nande, Jeffrey Naber (2009) Study of Basic Injection Configurations using a Direct-Injection Hydrogen Research Engine. (SAE 2009-01-1418) (Not yet published, to be presented at SAE World Congress April 2009.)