Operation strategy of a Dual Fuel HCCI Engine with VGT

Research output: Chapter in Book/Report/Conference proceedingPaper in conference proceeding

Abstract

HCCI combustion is well known and much results regarding
its special properties have been published.
Publications comparing the performance of different
HCCI engines and comparing HCCI engines to conventional
engines have indicated special features of
HCCI engines regarding, among other things, emissions,
efficiency and special feedback-control requirements.
This paper attempts to contribute to the common
knowledge of HCCI engines by describing an operational
strategy suitable for a dual-fuel port-injected
Heavy Duty HCCI engine equipped with a variable geometry
turbo charger. Due to the special properties of
HCCI combustion a specific operational strategy has
to be adopted for the engine operation parameters (in
this case combustion phasing and boost pressure).
The low exhaust temperature of HCCI engines limits
the benefits of turbo charging and causes pumping
losses which means that “the more the merrier” principle
does not apply to intake pressure for HCCI engines.
It is desirable not to use more boost pressure
than necessary to avoid excessively rapid combustion
and/or emissions of NOx. It is also desirable to select
a correct combustion phasing which, like the boost
pressure, has a large influence on engine efficiency.
The optimization problem that emerges between the
need for boost pressure to avoid noise and emissions
and, at the same time, avoiding an extensive decrease
of efficiency because of pumping losses is the
topic of this paper. The experiments were carried out
on a 12 liter Heavy Duty Diesel engine converted to
pure HCCI operation. Individually injected natural gas
and n-Heptane with a nominal injection ratio of 85%
natural gas and the rest n-Heptane (based on heating
value) was used as fuel. The engine was under feedback combustion control during the experiments.

Details

Authors
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Other Mechanical Engineering

Keywords

  • natural gas, Operation strategy, HCCI
Original languageEnglish
Title of host publicationSAE Technical Papers
PublisherSAE
Publication statusPublished - 2007
Publication categoryResearch
Peer-reviewedNo

Publication series

Name
Number2007-01-1855
ISSN (Print)0096-5170

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