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U.S. Department of Energy
Office of Scientific and Technical Information

Hydrogen cryofuel in internal combustion engines

Conference ·
OSTI ID:45412
 [1]
  1. German Aerospace Research Establishment, Stuttgart (Germany)
The main reason to support hydrogen as a fuel lies in the foreseeable problems regarding the CO{sub 2} pollution of the Earth`s atmosphere due to the unrestrained use of fossil energy. While combustion of currently used, or feasible hydrocarbon fuels releases about the same amount of CO{sub 2} per amount of heat produced, even hydrocarbon fuels with a greater hydrogen content do not lead to substantial improvement in this regard. Hydrogen represents the only practical, technically feasible, carbon free fuel. Cryogenic characteristics of hydrogen such as high density and a considerable cooling effect favor the fuel injection, the mixing process and thus the combustion process. In addition to the preferred use of liquid hydrogen due to its range per tank filling and low amount of mass for storage in the vehicle, the cryogenic characteristics of hydrogen provide significant advantages. In addition to engine operation with external mixture formation, considerable success was made with internal mixture formation with injection of cryogenic high pressure hydrogen. Only pressurization of cryogenic hydrogen can be accomplished without investing a considerable amount of engine power. Hybrid mixture formation, a proper combination of external and internal mixture formation with suitably pressurized cryogenic hydrogen, is very attractive with respect to power and torque flow as well as other positive characteristics under steady and intermittent operating conditions. The state of the art technology of liquid hydrogen represents a suitable base for large scale demonstration projects now. Additional aims of more intense R&D work relate to internal mixture formation and improved engine roadability as well as utility vehicle application including trucks and buses. With respect to fuel costs there will be an increased demand in developing hydrogen production free from CO{sub 2} emissions even from fossil energy sources such as crude oil or natural gas.
OSTI ID:
45412
Report Number(s):
CONF-930703--
Country of Publication:
United States
Language:
English