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Karhu, Toomas
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Different Methods to Improve the Exhaust Gas Temperature in Modern Stage V Off-Road Diesel Engine over Transient Emission Cycles

Turku University of Applied Sciences-Mika Lauren, Toomas Karhu, Miika Laivola, Jan Ekman
University of Vaasa-Seppo Niemi, Kirsi Spoof-Tuomi
  • Technical Paper
  • 2020-01-0903
To be published on 2020-04-14 by SAE International in United States
This paper presents several methods to improve the exhaust gas temperature of a modern diesel engine. A high exhaust gas temperature is needed to improve the after-treatment system efficiency and particulate filter regeneration in low engine loads. This study is based on experimental measurements of two Stage 5 level off-road diesel engines. The effect of the different heating methods determined over steady state runs and emission and performance are presented with standard emission transient test procedure (NRTC). In the first step of the study, an intake air restriction and an exhaust gas restriction method are compared. The intake restriction produces better fuel economy over the measuring cycle. However, with the exhaust restriction, higher exhaust gas temperature can be achieved in low engine loads. In the second phase of study, the intake air restriction method was implemented in the research engine. In addition, active waste gate controlling, and injection retardation methods were taken in use for heating purposes. The engine performance was determined with normal calibration and with high exhaust temperature calibration. The differences to the…
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Exhaust Particle Number in Off-Road Engines of Different Generations

Turku University of Applied Sciences-Toomas Karhu, Mika Laurén, Krister Ekman, Pekka Nousiainen, Tommi Paanu
University of Vaasa-Seppo Niemi, Kaj Lundin
Published 2009-06-15 by SAE International in United States
In diesel engine development, NOx and particulate matter (PM) emissions have to be simultaneously reduced. Fuel consumption also has to be kept as low as possible. Today, exhaust PM is regulated based on particle mass. Ultra-fine particles are, however, known to be hazardous for human health but they do not very much affect the PM mass. Thus, the health effects of an engine can not be evaluated based only on PM mass.To assess the adverse effects of particles, the particle number should also be examined. In this study, particle number emissions were therefore analyzed in several off-road diesel engines of different ages. The engines were developed for low emissions and fuel consumption experimentally, by usually running them according to the 8-mode ISO 8178-4 C1 off-road test cycle. Modern low-sulfur diesel fuel oil was burned, the sulfur content of the batches varying from 8 to 60 mg/kg. In addition to regulated gaseous emissions, the exhaust smoke and particle number concentrations were determined. An ELPI analyzer was adopted for PM number recordings.The results showed that the number…
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