Lean-burn hydrogen spark-ignited engines: the mechanical equivalent to
the fuel cell
The URL in the next line must be on one LONG line, it is wrapped here.
I don't know how long it is good for, these search links expire fast.
http://gpo.osti.gov:901/cgi-bin/dds_upload.pl?doc=6477}vbua~3f%29lvncan~7e,60B.D~3b0637262%29N8~3f277705-qbe~23sje4$r~7frc~3b~25ce~3e
Report Bibliographic Record
Lean-burn hydrogen spark-ignited engines: the mechanical equivalent to
the fuel cell. 23p. DOE Contract W-7405-ENG-48. (CONF-961017--9: ).
Order Number DE96011453. Source: OSTI; NTIS; GPO Dep. Fuel cells are
considered as the ideal power source for future vehicles, due to their
high efficiency and low emissions. However, extensive use of fuel cells
in light-duty vehicles is likely to be years away, due to their high
manufacturing cost. Hydrogen-fueled, spark-ignited, homogeneous-charge
engines offer a near-term alternative to fuel cells. Hydrogen in a
spark-ignited engine can be burned at very low equivalence ratios, so
that NO[sub x] emissions can be reduced to less than 10 ppm without
catalyst. HC and CO emissions may result from oxidation of engine oil,
but by proper design are negligible (a few ppm). Lean operation also
results in increased indicated efficiency due to the thermodynamic
properties of the gaseous mixture contained in the cylinder. The high
effective octane number of hydrogen allows the use of a high compression
ratio, further increasing engine efficiency. In this paper, a simplified
engine model is used for predicting hydrogen engine efficiency and
emissions. The model uses basic thermodynamic equations for the
compression and expansion processes, along with an empirical correlation
for heat transfer, to predict engine indicated efficiency. A friction
correlation and a supercharger/turbocharger model are then used to
calculate brake thermal efficiency. The model is validated with many
1345 experimental points obtained in a recent evaluation of a hydrogen
research engine. The experimental data are used to adjust the empirical
constants in the heat release rate and heat transfer correlation. The
adjusted engine model predicts pressure traces, indicated efficiency and
NO,, emissions with good accuracy over the range of speed, equivalence
ratio and manifold pressure experimentally covered.
BIBLIOGRAPHIC FIELDS
BarCode
M96011453
Doc.Type
R
Lit.Indicator
K
GPO#
E 1.99
Spon.Org.
DOE/ER
Title
Lean-burn hydrogen spark-ignited engines: the mechanical equivalent to
the fuel cell
DistrCode
4
PagesBiblio.
23
DistrFormat
A
Language
English
Availability
OSTI; NTIS; GPO Dep.
Proj.Status
P
AnnounCode
EDB;ERA;ETD;NTS
Subj.Cat.
330800;330101
BiblioSource
TIC
Subj.Class
33;33
CtryOfPubl.
US
CorpText
Lawrence Livermore National Lab., CA (United States)
Report.#
UCRL-JC--124095
Author
Aceves, S.M.; Smith, J.R.
SysEntryDate
19970814
PublDateCalc
19961231
Distr.Code
MN-400
Distr.Ctgry
General
Lit.Indctor
Conference literature, either as published proceedings or individual papers
DocType
Report
Serial Number
96001669709
Report#
UCRL-JC--124095
SecReport#
CONF-961017--9
PckdSecRpt#
CONF;CONF961017;CONF9610179
Contract #
W-7405-ENG-48
Doc.#
DE96011453
Priority #
UCRLJC124095;CONF9610179
Title
Lean-burn hydrogen spark-ignited engines: the mechanical equivalent to
the fuel cell
Conf.Title
American Society of Mechanical Engineers (ASME) and Metals materials week
Subj.Ctgy.
ALTERNATIVE FUELS;SPARK-IGNITION
Descriptors
VEHICLES/spark ignition engines; HYDROGEN FUELS/combustion; NITROGEN
OXIDES/emission; SPARK IGNITION ENGINES/thermodynamic model; VEHICLES;
COMBUSTION; HYDROCARBONS; ANTIKNOCK RATINGS; IGNITION QUALITY;
SUPERCHARGERS; TURBOCHARGERS; EFFICIENCY; EMISSION; FUEL-AIR RATIO;
HYBRID SYSTEMS
Abstract
Fuel cells are considered as the ideal power source for future vehicles,
due to their high efficiency and low emissions. However, extensive use
of fuel cells in light-duty vehicles is likely to be years away, due to
their high manufacturing cost. Hydrogen-fueled, spark-ignited,
homogeneous-charge engines offer a near-term alternative to fuel cells.
Hydrogen in a spark-ignited engine can be burned at very low equivalence
ratios, so that NO[sub x] emissions can be reduced to less than 10 ppm
without catalyst. HC and CO emissions may result from oxidation of
engine oil, but by proper design are negligible (a few ppm). Lean
operation also results in increased indicated efficiency due to the
thermodynamic properties of the gaseous mixture contained in the
cylinder. The high effective octane number of hydrogen allows the use of
a high compression ratio, further increasing engine efficiency. In this
paper, a simplified engine model is used for predicting hydrogen engine
efficiency and emissions. The model uses basic thermodynamic equations
for the compression and expansion processes, along with an empirical
correlation for heat transfer, to predict engine indicated efficiency. A
friction correlation and a supercharger/turbocharger model are then used
to calculate brake thermal efficiency. The model is validated with many
1345 experimental points obtained in a recent evaluation of a hydrogen
research engine. The experimental data are used to adjust the empirical
constants in the heat release rate and heat transfer correlation. The
adjusted engine model predicts pressure traces, indicated efficiency and
NO,, emissions with good accuracy over the range of speed, equivalence
ratio and manifold pressure experimentally covered.
SponsorCode
USDOE, Washington, DC (United States)
LAB
LLNL
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