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The Effect of Displacement on Air-Diluted Multi-Cylinder HCCI Engine Performance

Hyvönen, Jari LU ; Wilhelmsson, Carl LU and Johansson, Bengt LU (2006)
Abstract
The main benefit of HCCI engines compared to SI engines is improved fuel economy. The drawback is the diluted combustion with a substantially smaller operating range if not some kind of supercharging is used. The reasons for the higher brake efficiency in HCCI engines can be summarized in lower pumping losses and higher thermodynamic efficiency, due to higher compression ratio and higher ratio of specific heats if air is used as dilution. In the low-load operating range, where HCCI today is mainly used, other parameters as friction losses, and cooling losses have a large impact on the achieved brake efficiency.



To initiate the autoignition of the in-cylinder charge a certain temperature and pressure have to be reached... (More)
The main benefit of HCCI engines compared to SI engines is improved fuel economy. The drawback is the diluted combustion with a substantially smaller operating range if not some kind of supercharging is used. The reasons for the higher brake efficiency in HCCI engines can be summarized in lower pumping losses and higher thermodynamic efficiency, due to higher compression ratio and higher ratio of specific heats if air is used as dilution. In the low-load operating range, where HCCI today is mainly used, other parameters as friction losses, and cooling losses have a large impact on the achieved brake efficiency.



To initiate the autoignition of the in-cylinder charge a certain temperature and pressure have to be reached for a specific fuel. In an engine with high in-cylinder cooling losses the initial charge temperature before compression has to be higher than on an engine with less heat transfer. The heat transfer to the combustion chamber walls is affected by parameters such as area-to-volume ratio and in-cylinder gas motion, i.e., turbulence.



In this paper the performance of three multi-cylinder HCCI engines with different displacements are compared. The engines are a five-cylinder 1.6dmu3 VCR engine, a four-cylinder 2.0dmu3 engine, and a six-cylinder 11.7dmu3 truck engine. All engines are port fuel injected and run with a RON91/MON82 gasoline. Combustion phasing is mainly controlled with inlet air temperature. The engines have about the same indicated efficiency but different brake efficiency. The truck engine has 32.3% brake efficiency at 2 bar BMEP, followed by the 2.0dmu3 engine with 29.8%, and the 1.6dmu3 VCR engine with only 24.4%. (Less)
Please use this url to cite or link to this publication:
author
; and
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
displacement, multi cylinder, HCCI, Air diluted
host publication
SAE Technical Papers
issue
2006-01-0205
publisher
SAE
external identifiers
  • scopus:85072421076
ISSN
0148-7191
language
English
LU publication?
yes
id
e637c05b-8136-4aa1-bf4b-4da4c0367781 (old id 538184)
alternative location
http://www.sae.org/technical/papers/2006-01-0205
date added to LUP
2016-04-01 15:48:29
date last changed
2021-02-17 07:26:01
@inproceedings{e637c05b-8136-4aa1-bf4b-4da4c0367781,
  abstract     = {The main benefit of HCCI engines compared to SI engines is improved fuel economy. The drawback is the diluted combustion with a substantially smaller operating range if not some kind of supercharging is used. The reasons for the higher brake efficiency in HCCI engines can be summarized in lower pumping losses and higher thermodynamic efficiency, due to higher compression ratio and higher ratio of specific heats if air is used as dilution. In the low-load operating range, where HCCI today is mainly used, other parameters as friction losses, and cooling losses have a large impact on the achieved brake efficiency. <br/><br>
<br/><br>
To initiate the autoignition of the in-cylinder charge a certain temperature and pressure have to be reached for a specific fuel. In an engine with high in-cylinder cooling losses the initial charge temperature before compression has to be higher than on an engine with less heat transfer. The heat transfer to the combustion chamber walls is affected by parameters such as area-to-volume ratio and in-cylinder gas motion, i.e., turbulence. <br/><br>
<br/><br>
In this paper the performance of three multi-cylinder HCCI engines with different displacements are compared. The engines are a five-cylinder 1.6dmu3 VCR engine, a four-cylinder 2.0dmu3 engine, and a six-cylinder 11.7dmu3 truck engine. All engines are port fuel injected and run with a RON91/MON82 gasoline. Combustion phasing is mainly controlled with inlet air temperature. The engines have about the same indicated efficiency but different brake efficiency. The truck engine has 32.3% brake efficiency at 2 bar BMEP, followed by the 2.0dmu3 engine with 29.8%, and the 1.6dmu3 VCR engine with only 24.4%.},
  author       = {Hyvönen, Jari and Wilhelmsson, Carl and Johansson, Bengt},
  booktitle    = {SAE Technical Papers},
  issn         = {0148-7191},
  language     = {eng},
  number       = {2006-01-0205},
  publisher    = {SAE},
  title        = {The Effect of Displacement on Air-Diluted Multi-Cylinder HCCI Engine Performance},
  url          = {https://lup.lub.lu.se/search/ws/files/4478241/625771.pdf},
  year         = {2006},
}