Approaches to Solve Problems of the Premixed Lean Diesel Combustion

1999-01-0183

03/01/1999

Event
International Congress & Exposition
Authors Abstract
Content
Previous research in our laboratory has shown that NOx emissions can be sharply reduced by PREDIC (PRE-mixed lean DIesel Combustion), in which fuel is injected very early in the compression process. However some points of concern remained unsolved, such as a large increase in THC and CO, higher fuel consumption, and an operating region narrowly limited to partial loads, compared to conventional diesel operation.
In this paper, the causes of PREDIC's problem areas were analyzed through engine performance tests and combustion observation with a single cylinder engine, through fuel spray observation with a high-pressure vessel, and through numerical modeling. Subsequently, measurable improvements were achieved on the basis of these analyses.
As a result, the ignition and combustion processes were clarified in terms of PREDIC fuel-air mixture formation. Thus, THC and CO emissions could be decreased by adopting a pintle type injection nozzle, or a reduced top-land-crevice piston. Fuel consumption was also improved by application of EGR or the addition of an oxygenated component to the diesel fuel. The operating region could be extended to higher load conditions by MULtiple stage DIesel Combustion (MULDIC), in which the first stage combustion corresponds to PREDIC. Furthermore, by combining PREDIC at low loads with MULDIC at high loads, Japanese Diesel 13 Mode NOx emissions could be reduced to 1 g/kWh.
Meta TagsDetails
DOI
https://doi.org/10.4271/1999-01-0183
Pages
15
Citation
Akagawa, H., Miyamoto, T., Harada, A., Sasaki, S. et al., "Approaches to Solve Problems of the Premixed Lean Diesel Combustion," SAE Technical Paper 1999-01-0183, 1999, https://doi.org/10.4271/1999-01-0183.
Additional Details
Publisher
Published
Mar 1, 1999
Product Code
1999-01-0183
Content Type
Technical Paper
Language
English