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| 4. |
- Haupt, Dan, et al.
(författare)
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Hydrocarbons and aldehydes from a diesel engine running on ethanol and equipped with EGR, catalyst and DPF
- 2004
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- A commercially available exhaust aftertreatment system, DNO\dx\sT, comprising exhaust gas recirculation (EGR), an oxidative catalyst and a continuously regenerating diesel particulate filter (DPF) were tested. The test object was a 9-liter, ethanol-fueled diesel engine from Scania equipped with turbocharger and aftercooler. A similar diesel engine from Scania, but running on ordinary Swedish diesel fuel, was used as a reference and a reminder of "the state of the art." The tests involved two different ethanol fuels containing various ignition improvers, Beraid 3540 and rapeseed methyl ester. Test conditions for the engines were those specified in the European Stationary Cycle (ESC). The aftertreatment system reduced the emissions of HC, CO and NO\dx, down to 0.15, 0.04 and 2.54 g/kWh, respectively, while the estimated particle mass was reduced by 67%. Actually, by using the DNO\dx\sT system, the engines became Euro IV engines regarding the emissions of HC, CO and NO\dx. The ethanol-fueled engine without EGR, catalyst or DPF emitted approximately 1.6 times more formaldehyde and 9.8 times more acetaldehyde than the diesel engine. However, the emission of acrolein was only 0.47 times the emission of acrolein from the diesel engine. When the ethanol-fueled engine was equipped with DNO\dx\sT, a significant reduction of the emissions of aldehydes was obtained. The emissions of acrolein, formaldehyde and acetaldehyde were reduced by 56%, 87% and 95%, respectively. An even higher reduction was observed when the system was connected to the diesel engine. Fifteen different hydrocarbons (alkanes, olefins and monoaromates) were also identified. The diesel-fueled engine, without any exhaust aftertreatment devices, emitted approximately twice as much hydrocarbon than the ethanol-fueled engine, also without any exhaust aftertreatment devices. However, there were also qualitative differences. Three hydrocarbons, namely propene, ethene and benzene, accounted for 77% of the hydrocarbons emitted from the diesel-fueled engine, while acetylene, ethene and benzene, made up only 53% of the hydrocarbons emitted from the ethanol-fueled engine. When connecting the system to the engines, a difference was observed; the reduction of analyzed hydrocarbon emissions was approximately 90% for the diesel-fueled engine, but only 47% for the ethanol-fueled engine. The studied aftertreatment system has been developed and optimized for the diesel-fueled engine. This fact is reflected in the powerful reduction of hydrocarbons, aldehydes, particles and NO\dx that is obtained when connecting the system to the diesel-fueled engine. Nevertheless, a significant reduction is also obtained when connecting the system to the ethanol-fueled engine. Test results indicate that it should be possible to better optimize the system for the ethanol engine. It is also, probably, necessary to exchange the catalyst in the system. Thereby, an even higher reduction of unregulated and regulated emissions should be obtained
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| 5. |
- Haupt, Dan, et al.
(författare)
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Investigating the potential to obtain low emissions from a diesel engine running on ethanol and equipped with EGR, catalyst and DPF
- 2004
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Experiments were performed to investigate the potential to achieve low emissions from a diesel engine fueled by ethanol and equipped with a commercially available exhaust after-treatment device, DNO\dx\sT from STT Emtec. The DNO\dx\sT system includes exhaust gas recirculation (EGR) catalysts and a continuously regenerating diesel particulate filter (DPF). Two Euro III classified 9-liter turbocharged, after-cooled diesel engines from Scania were used for the task. One engine was fueled by ethanol and the other by Swedish diesel fuel, EC1. Engine operating conditions of a 22-mode test cycle, including the 13 modes of the European Stationary Cycle (ESC cycle), were used for the tests. The emissions of NO\dx and HC were small for the ethanol-fueled engine, 3.48 and 0.53 g/kWh, respectively, while the emission of CO was higher, 2.07 g/kWh. Estimations of emitted particle mass were calculated by using the software supplied in the Scanning Mobility Particle Sizer (SMPS). The estimations showed that the ethanol engine emitted only \mA1/10 of the particle mass emitted by the diesel-fueled engine. A powerful reduction of the regulated emissions was obtained when equipping the ethanol engine with EGR, catalyst and DPF. The emissions of HC, CO and NO\dx decreased down to 0.15, 0.04 and 2.54 g/kWh, respectively, while the estimated particle mass was reduced by 67%. Actually, by using the aftertreatment system, the engine became a Euro IV engine regarding the emissions of HC, CO and NO\dx. The system worked even better with the diesel-fueled engine. The NO\dx emission was reduced by approximately 33% and the estimated particle mass by more than 99%. Calculations showed that the EGR ratio was higher for the diesel engine than for the ethanol engine. Consequently, by applying a higher EGR ratio for the ethanol engine an additional reduction of the NO\dx emissions should be obtained. The results indicate that very low NO\dx and particle emissions could be obtained for an ethanol-fueled diesel engine by using the right aftertreatment equipment. Future studies should investigate the possibility to increase the EGR ratio further. The investigations also underline the need for development of a special particulate filter for ethanol engines.
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- Nord, Kent, et al.
(författare)
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Evaluating a Fischer-Tropsch fuel, eco-parst in a Valmet diesel engine
- 2002
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Reports have stated that Fischer Tropsch (FT) fuels are high quality, low emission diesel fuel substitutes. The purpose of this study is to compare the emissions from a heavy-duty, Valmet, diesel engine running on a commercial available FT fuel, Eco-Par\sT, with the emissions obtained when the same engine is running on a low-sulfur diesel fuel with low aromatic content, Swedish environmental class 1 (EC-1) diesel fuel. The two fuels have been analyzed by Fourier transform infrared spectroscopy and Raman Fourier transform infrared spectroscopy. The analyses showed that main constituents in the two fuels are alkanes with no substituents. No aromates or olefines could be detected. A small difference, later verified by gas chromatographic analyses, was noted; the Swedish EC-1 fuel consisted of a larger portion of straight chain, heavier hydrocarbons while the FT fuel consisted of more branched hydrocarbons. The overall impression of the emission analyses is that Eco- Par\sT gives lower emission than the EC-1 fuel during the modes employed in the ISO 8178 test. Emissions of acetaldehyde, benzaldehyde and acrolein were generally decreased 3-6 times when using FT fuel instead of EC-1 fuel while the emission of formaldehyde was unaffected. Fifteen volatile organic hydrocarbons were also included in the investigation - ethane, ethene, acetylene, propane, propene, propyne, propadiene, isobutene, isobutene, 1-butene, 1,3- butadiene, benzene, toluene, O-xylene and M-xylene. The emissions of the fifteen mentioned hydrocarbons were reduced between 20% - 93% when using Eco-Par\sT instead of EC-1. Measurements of the regulated emissions during an ISO 8178 test confirmed the obtained results; the emissions of total hydrocarbon (HC) decreased approx. 14% while the emissions of carbon monoxide, CO, and nitrogen oxides, NO\dx were almost unaffected. The test results in this investigation may indicate that diesel engines running on Eco-Par\sT can have a lower impact on environment and health than the, in Sweden, commonly used EC-1 fuel.
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- Nord, Kent, et al.
(författare)
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Particles and emissions from a diesel engine equipped with a humid air motor system
- 2001
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- A humid air motor system (HAM) for NO\dx reduction has been connected to an eleven liters diesel engine. Earlier studies have demonstrated that the system has capacity to lower NO\dx emissions from diesel engines. The present study is directed to investigate the influence of the system on the emissions of particles and aldehydes, to monitor essential engine parameters, water consumption, and to verify the NO\dx reducing ability. The system has been tested under the various speed and load conditions stated in the 13-mode ECE R- 49 test procedure. Additional tests have been carried out for sampling and measurements of particles. The results showed that the particle number concentration usually increased when HAM was coupled to the engine. The increase in particle number concentration, observed in five out of six running modes, varied between 46% and 148%. There was no observed trend indicating a shift in mean particle diameter when using HAM. Engine performance was almost unaffected, while the HAM system caused a large reduction of the NO\dx emissions. Even without optimization of the experimental conditions the average reduction of NO\dx during the different modes of ECE R-49 was over 51%. The reduction was directly related to the humidity of the inlet air and a further reduction can be anticipated with higher humidity. The influence of the system on the emissions of hydrocarbons (HC) was negligible while a moderate increase in the emission of carbon monoxide (CO) was noticed. No confident relationship between air humidity and the observed effects (i.e., on HC and CO) could be detected. Samples were also taken for acetaldehyde and formaldehyde. The results are indicating a reduction of aldehydes in the range 78% to 100%, when using HAM. Unfortunately these large reductions may be false, since it cannot be excluded that they are a result of a combination of high air humidity and the sampling technique used.
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| 8. |
- Nord, Kent, et al.
(författare)
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Particulate emissions from an ethanol-fueled, heavy-duty diesel engine equipped with EGR, catalyst and DPF
- 2004
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Ethanol-fueled engines are considered to be low particulate-emitting engines. This study was performed to investigate the potential to achieve even lower particulate emission if a 9-liter Scania diesel engine, running on ethanol fuel is equipped with emission control. State-of-the-art technology in emission control was applied, e.g., exhaust gas recirculation, EGR, catalysts and a continuous regenerating particle filter, DPF. Particulate emissions were compared with emissions from a 9-liter Scania diesel engine from the same engine family, running on Swedish environmental class 1 diesel fuel. Tailpipe measurements of particle size and distribution were performed with a scanning mobility particle sizer, SMPS, instrument together with filter sampling. An evaluation of SMPS measurements was performed for test conditions specified according to a 22-mode test cycle, which included the test modes in the European Stationary Cycle, ESC. Calculated weighted particle mass from SMPS data, and in accordance with ESC, showed that the ethanol engine without emission control emitted approx. 1/12 of particle mass compared to the diesel engine. Weighted particulate emissions were reduced by approx. 96%, when the engine was fitted with EGR and DPF. The reduction of weighted particulate emissions was even higher when the diesel engine was fitted with EGR and DPF, as high as 99%. Particle size and distribution measurements revealed that particles emitted from the ethanol engine mainly consisted of ultrafine particles (\ml100 nm), usually had a mean diameter of about 30 nm, while particles emitted from the diesel engine usually had mean diameters of about 60-70 nm and sizes going up to approx. 300 nm. Filter samples analyzed by Scanning electron microscopy and energy dispersive x-ray analysis SEM/EDX showed that the particles, both from the ethanol-fueled engine and the diesel-fueled engine mainly consisted of carbon and that they agglomerated, dependent upon running conditions, chainlike or clot-wise. Raman spectroscopy confirmed that the same elemental carbon was present in particles emitted from diesel and ethanol-fueled engines. The investigations showed that the system used, with EGR and DPF combined, is highly effective in reducing particulate emissions from ethanol- and diesel-fueled diesel engines. A general conclusion is also that the ethanol-fueled engine, equipped with emission control system or not, emitted lower particle mass, smaller particle sizes and approx. the same or a greater number of particles in the emissions than the diesel-fueled engine.
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| 10. |
- Zurita, Grover, et al.
(författare)
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Vibration based diagnostics of the combustion process in ethanol fueled-engine
- 2000
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Ingår i: COMADEM 2000. - Haymarket, Va : Society for Machinery Failure Prevention Technology. - 0963545027 ; , s. 607-616
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Konferensbidrag (refereegranskat)abstract
- Due to stringent regulations, tremendous efforts have been made worldwide in monitoring and diagnosing combustion engines. However, there is still a large need to further develop optimization models that facilitate the understanding of the relationship between engine parameters and parameters such as noise and exhaust emissions. The aim of present study was to investigate the potential use of vibration based diagnostics for prediction of different parameters such as noise, exhaust emissions, Pmax and the dp/d alpha . The method is based on a reconstruction of the cylinder pressure from vibration measurements on the engine surface. A three factorial central composite face design was used for the tests involving different running conditions (i.e. speeds and loads) and different blends of rap seed oil methyl esther (RME)/ethanol. Principal component analysis (PCA) and partial least squares (PLS) were thereafter used for establishing models that show the relationship between speed, load, amount of RME and responses such as cylinder pressure, exhaust emissions and sound pressure. The results show that the reconstructed cylinder pressure can be used for diagnostics and control by allowing an accurate estimation of Pmax and dp/d alpha . Furthermore, the method used is also applicable for determining apparent net heat release rate and hence the exact time of the start of the combustion process. A comparison between measured and predicted values of NOx, noise, Pmax and dp/d alpha showed a good predictive power of the established models.
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