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The Effect of Intake Temperature in a Turbocharged Multi Cylinder Engine Operating in HCCI Mode

Johansson, Thomas LU ; Tunestål, Per LU ; Johansson, Bengt LU and Aulin, Hans LU (2009) In SAE International Journal of Engines 2(2). p.452-466
Abstract (Swedish)
The operating range in HCCI mode is limited by the excessive pressure rise rate and therefore high combustion induced noise. The HCCI range can be extended with turbocharging which enables increased dilution of the charge and thus a reduction of combustion noise. When the engine is turbocharged the intake charge will have a high temperature at increased boost pressure and can then be regulated in a cooling circuit. Limitations and benefits are examed at 2250 rpm and 400 kPa indicated mean effective pressure. It is shown that combustion stability, combustion noise and engine efficiency have to be balanced since they have optimums at different intake temperatures and combustion timings. The span for combustion timings with high combustion... (More)
The operating range in HCCI mode is limited by the excessive pressure rise rate and therefore high combustion induced noise. The HCCI range can be extended with turbocharging which enables increased dilution of the charge and thus a reduction of combustion noise. When the engine is turbocharged the intake charge will have a high temperature at increased boost pressure and can then be regulated in a cooling circuit. Limitations and benefits are examed at 2250 rpm and 400 kPa indicated mean effective pressure. It is shown that combustion stability, combustion noise and engine efficiency have to be balanced since they have optimums at different intake temperatures and combustion timings. The span for combustion timings with high combustion stability is narrower at some intake temperatures and the usage of external EGR can improve the combustion stability. It is found that the standard deviation of combustion timing is a useful tool for evaluating cycle to cycle variations. One of the benefits with HCCI is the low pumping losses, but when load and boost pressure is increased there is an increase in pumping losses when using negative valve overlap. The pumping losses can then be circumvented to some extent with a low intake temperature or EGR, leading to more beneficial valve timings at high load. (Less)
Abstract
The operating range in HCCI mode is limited by the excessive pressure rise rate and therefore high combustion induced noise. The HCCI range can be extended with turbocharging which enables increased dilution of the charge and thus a reduction of combustion noise. When the engine is turbocharged the intake charge will have a high temperature at increased boost pressure and can then be regulated in a cooling circuit. Limitations and benefits are examed at 2250 rpm and 400 kPa indicated mean effective pressure. It is shown that combustion stability, combustion noise and engine efficiency have to be balanced since they have optimums at different intake temperatures and combustion timings. The span for combustion timings with high combustion... (More)
The operating range in HCCI mode is limited by the excessive pressure rise rate and therefore high combustion induced noise. The HCCI range can be extended with turbocharging which enables increased dilution of the charge and thus a reduction of combustion noise. When the engine is turbocharged the intake charge will have a high temperature at increased boost pressure and can then be regulated in a cooling circuit. Limitations and benefits are examed at 2250 rpm and 400 kPa indicated mean effective pressure. It is shown that combustion stability, combustion noise and engine efficiency have to be balanced since they have optimums at different intake temperatures and combustion timings. The span for combustion timings with high combustion stability is narrower at some intake temperatures and the usage of external EGR can improve the combustion stability. It is found that the standard deviation of combustion timing is a useful tool for evaluating cycle to cycle variations. One of the benefits with HCCI is the low pumping losses, but when load and boost pressure is increased there is an increase in pumping losses when using negative valve overlap. The pumping losses can then be circumvented to some extent with a low intake temperature or EGR, leading to more beneficial valve timings at high load. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
SAE International Journal of Engines
volume
2
issue
2
pages
15 pages
publisher
SAE
external identifiers
  • scopus:77953063863
ISSN
1946-3944
DOI
10.4271/2009-24-0060
language
English
LU publication?
yes
id
bcdef6f1-7023-40d3-93a7-fac970bd273e
date added to LUP
2017-12-12 14:51:55
date last changed
2018-02-11 04:33:35
@article{bcdef6f1-7023-40d3-93a7-fac970bd273e,
  abstract     = {The operating range in HCCI mode is limited by the excessive pressure rise rate and therefore high combustion induced noise. The HCCI range can be extended with turbocharging which enables increased dilution of the charge and thus a reduction of combustion noise. When the engine is turbocharged the intake charge will have a high temperature at increased boost pressure and can then be regulated in a cooling circuit. Limitations and benefits are examed at 2250 rpm and 400 kPa indicated mean effective pressure. It is shown that combustion stability, combustion noise and engine efficiency have to be balanced since they have optimums at different intake temperatures and combustion timings. The span for combustion timings with high combustion stability is narrower at some intake temperatures and the usage of external EGR can improve the combustion stability. It is found that the standard deviation of combustion timing is a useful tool for evaluating cycle to cycle variations. One of the benefits with HCCI is the low pumping losses, but when load and boost pressure is increased there is an increase in pumping losses when using negative valve overlap. The pumping losses can then be circumvented to some extent with a low intake temperature or EGR, leading to more beneficial valve timings at high load.},
  articleno    = {2009-24-0060},
  author       = {Johansson, Thomas and Tunestål, Per and Johansson, Bengt and Aulin, Hans},
  issn         = {1946-3944},
  language     = {eng},
  month        = {09},
  number       = {2},
  pages        = {452--466},
  publisher    = {SAE},
  series       = {SAE International Journal of Engines},
  title        = {The Effect of Intake Temperature in a Turbocharged Multi Cylinder Engine Operating in HCCI Mode},
  url          = {http://dx.doi.org/10.4271/2009-24-0060},
  volume       = {2},
  year         = {2009},
}