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

University of Vaasa-Seppo Niemi, Kirsi Spoof-Tuomi
Turku University of Applied Sciences-Mika Lauren, Toomas Karhu, Miika Laivola, Jan Ekman
  • 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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Role of lubricating oil properties in exhaust particle emissions of an off-road diesel engine

University of Vaasa-Teemu Ovaska, Seppo Niemi, Katriina Sirviö, Olav Nilsson
Neste Corporation-Kari Kulmala
  • Technical Paper
  • 2020-01-0386
To be published on 2020-04-14 by SAE International in United States
Particle number emissions from an off-road diesel engine without exhaust after-treatment were studied by using five different heavy-duty lubricating oils in the engine. The study extends understanding how the properties of lubricating oil affect the emissions of the smallest nanoparticles from a modern off-road diesel engine. The lubricants were selected among the performance classes of the European Automobile Manufacturers Association, at least one lubricant from each category intended for heavy-duty diesel engines. Particle size distributions were measured by means of an engine exhaust particle sizer (EEPS), but particle mass emissions, soot emissions, gaseous emissions and the basic engine performance were also determined. During the non-road steady cycle, the most of the differences were detected at the particle sizes of 6–15 nm. In most cases, the lowest particle quantities were emitted when the highest performance category lubricant was used. Based on the results of this study, the low contents of Zn, P, and S in lubricating oil contributed to the reduced emission factors for engine-out nucleation mode particles at any load. In addition, the low content…
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Analysis of Cylinder Pressure Measurement Accuracy for Internal Combustion Engine Control

University of Vaasa-Xiaoguo Storm, Heikki J. Salminen, Reino Virrankoski, Seppo Niemi
Wartsila Finland Oy-Jari Hyvonen
Published 2017-03-28 by SAE International in United States
With the tightening requirements on engine emission and performance, pressure based combustion controls are becoming common in medium speed large bore reciprocating internal combustion engines. The accuracy of the cylinder pressure data including the raw pressure value at its corresponding crank angle, has a vital impact on engine controllability. For instance, this work shows that a 1-bar pressure offset leads to a 0.6% variation in the total heat release (THR) while the 50% heat release crank angle (CA50) can be shifted by 1.5 degrees. Similarly, with a single degree error in the crank position, the indicated mean effective pressure (IMEP) gets a 1.8 bar error. Thus, in this work the typical errors for cylinder pressure measurement are reviewed and analyzed for large bore four stroke marine and power plant production engines.The main sources of error for pressure measurement are thermal shock and installation defects. Meanwhile, calibration is carried out for ten production pressure transducers to provide a general accuracy result of the pressure transducers that are used in production engines.The main sources of error for…
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Effect of Injection Parameters on Exhaust Gaseous and Nucleation Mode Particle Emissions of a Tier 4i Nonroad Diesel Engine

University of Vaasa-Seppo Niemi
Metropolia Univ of Applied Sciences-Liisa Pirjola
Published 2013-10-14 by SAE International in United States
During the past few decades the exhaust emissions of diesel engines have significantly decreased due to efficient emissions regulation. Compared to the situation in the 1990s, the nitrogen oxide (NOx) and particulate matter (PM) emissions, the main challenges for diesel engines, are now reduced 80-95 % in many industrialized countries. To meet the demanding requirements, engine technologies have been updated and improved step by step. These improvements have also kept Specific Fuel Consumption (SFC) figures at a low level or they have even improved. The latter issue is of great significance for consumers (cost) and also for the environment (CO2).Nowadays many diesel engine fuel injection strategies rely on the use of exhaust after-treatment systems. Efficient and clean combustion is obtained by utilizing high injection pressure and advanced injection timing. The resulting high engine-out NOx is reduced to the target level by using an efficient NOx after-treatment system, possibly supported by an EGR system. In several applications no particulate filter is necessarily yet required for a nonroad engine to meet its emission limits. However, according to…
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HC-SCR Catalyst for NOx Reduction in a Non-Road Diesel Engine

University of Vaasa-Seppo Niemi, Kaj Lundin
Turku University of Applied Sciences-Janne Perus, Mika Laurén, Krister Ekman, Pekka Nousiainen
Published 2009-10-06 by SAE International in United States
Exhaust pollutants of diesel engines have to be drastically reduced. The oxides of nitrogen (NOx) and particulate matter (PM) form the main challenge for diesel exhaust cleaning. The fuel economy of the engines must also be kept at an adequate level to prevent the increase in CO2 emissions and operational costs.For diesel engines, there are two main strategies for the reduction of NOx emissions. One is to increase the volume of cooled exhaust gas recirculation (EGR). The other is to use selective catalytic reduction (SCR) for NOx removal. For SCR, urea derived ammonia may be exploited but NOx can also be catalytically reduced by means of hydrocarbons (HC) originating from engine fuel. This latter system is termed HC-SCR.In the present study, an Ag-alumina based prototype HC-SCR catalyst was studied for NOx removal in a turbocharged, intercooled direct-injection non-road diesel engine. The fuel post-injection of the engine common-rail injection system was optimized to produce a sufficient amount of hydrocarbons into the exhaust gases. The efficiency of the catalyst was then investigated in a few sets of…
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Exhaust Particle Number in Off-Road Engines of Different Generations

University of Vaasa-Seppo Niemi, Kaj Lundin
Turku University of Applied Sciences-Toomas Karhu, Mika Laurén, Krister Ekman, Pekka Nousiainen, Tommi Paanu
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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