| 1. |
- Golovitchev, Valeri, 1945, et al.
(författare)
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Modeling of Combustion and Emissions Formation in Heavy Duty Diesel Engine Fueled by RME and Diesel Oil
- 2009
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Ingår i: SAE Technical Papers. - 0148-7191 .- 2688-3627. ; , s. 1-13
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Konferensbidrag (refereegranskat)abstract
- A comparative study on engine performance and emissions (NOx, soot) formation has been carried out for the Volvo D12C diesel engine fueled by Rapeseed Methyl Ester, RME and conventional diesel oil. The fuel and combustion models used in this paper are the modifications of those described in [1-3]. The numerical results for different load cases illustrate that for both fuels nearly 100% combustion efficiency was predicted; in the case of RME, the cumulative heat release was compared with the RME LHV, 37.2 kJ/g. To minimize soot and NOx emissions, 25-30% EGR levels depending on the engine loads and different injection timings were analyses. To illustrate the optimal engine performance conditions, a special technique based on the time-transient parametric -T maps [4] has been used.
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| 2. |
- Golovitchev, Valeri, 1945, et al.
(författare)
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Modeling of combustion and emissions formation in heavy duty diesel engine fueled by RME and diesel oil
- 2010
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Ingår i: SAE International Journal of Engines. - : SAE International. - 1946-3944 .- 1946-3936. ; 2:2, s. 355-367
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Tidskriftsartikel (refereegranskat)abstract
- A comparative study on engine performance and emissions (NOx, soot) formation has been carried out for the Volvo D12C diesel engine fueled by Rapeseed Methyl Ester, RME and conventional diesel oil. The fuel and combustion models used in this paper are the modifications of those described in [1-3]. The numerical results for different load cases illustrate that for both fuels nearly 100% combustion efficiency was predicted; in the case of RME, the cumulative heat release was compared with the RME LHV, 37.2 kJ/g. To minimize soot and NOx emissions, 25-30% EGR levels depending on the engine loads and different injection timings were analyses. To illustrate the optimal engine performance conditions, a special technique based on the time-transient parametric φ-T maps [4] has been used
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| 3. |
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| 4. |
- Armbruster, Henriet, et al.
(författare)
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On-board Conversion of Alcohol to Ethers for diesel Engines
- 2000
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Ingår i: ISAF XIII Paper. International Symposium on Alcohol Fuels. Implementing the Transition to a Sustainable Transport System, Stockholm 3-6 July 2000..
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Konferensbidrag (refereegranskat)
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| 5. |
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| 6. |
- Ehleskog, Malin, 1980, et al.
(författare)
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Effects of High Injection Pressure, EGR and Charge Air Pressure on Combustion and Emissions in an HD Single Cylinder Diesel Engine
- 2009
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Ingår i: SAE International Journal of Engines. - : SAE International. - 1946-3944 .- 1946-3936. ; 2:2, s. 341-354
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Tidskriftsartikel (refereegranskat)abstract
- When increasing EGR from low levels to a level that corresponds to low-temperature combustion, soot emissions initially increase due to lower soot oxidation before decreasing to almost zero due to very low soot formation. At the EGR level where soot emissions start to increase, the NOx emissions are low, but not sufficiently low to comply with future emission standards and at the EGR level where low-temperature combustion occurs CO and HC emissions are too high.The purpose of this study was to investigate the possibilities for shifting the so-called soot bump (where soot levels are increased) to higher EGR levels, or to reduce the magnitude of the soot bump using very high injection pressures (up to 240 MPa) while reducing the NOx emissions using EGR. The possibility of reducing the CO and HC emissions at high EGR levels due to the increased mixing caused by higher injection pressure was also investigated and the flame was visualized using an endoscope at chosen EGR values. In addition, flame temperatures and soot volume fractions were determined using two-color pyrometry.A single-cylinder heavy-duty direct injection diesel engine equipped with an electronically controlled unit injector with variable needle opening pressure was used in the investigations, with geometry based on the Volvo D12C production engine but with the compression ratio reduced from 18.5 to 14.The results from the studied cases showed that increasing EGR from 0 to 30% reduces both soot formation and oxidation resulting in higher engine-out soot emissions. Also, an increase in NOP for a case without EGR was found to give both high soot formation and high soot oxidation, resulting in reduced engine-out soot emissions. When EGR was added, increased NOP resulted in increased soot oxidation and thus in lower engine-out soot emissions. An increase in NOP was also found to reduce HC and CO emissions at high EGR levels.
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| 7. |
- Ehleskog, Malin, 1980, et al.
(författare)
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Effects of Variable Inlet Valve Timing and Swirl Ratio on Combustion and Emissions in a Heavy Duty Diesel Engine
- 2012
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Ingår i: SAE Technical Papers. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International. - 0148-7191 .- 2688-3627. ; 9
-
Tidskriftsartikel (refereegranskat)abstract
- In order to avoid the high CO and HC emissions associated with low temperature when using high levels of EGR, partially premixed combustion is an interesting possibility. One way to achieve this combustion mode is to increase the ignition delay by adjusting the inlet valve closing timing, and thus the effective compression ratio.The purpose of this study was to investigate experimentally the possibilities of using late and early inlet valve closure to reduce NOxemissions without increasing emissions of soot or unburned hydrocarbons, or fuel consumption. The effect of increasing the swirl number (from 0.2 to 2.5) was also investigated. The combustion timing (CA50) was kept constant by adjusting the start of injection and the possibilities of optimizing combustion using EGR and high injection pressures were investigated. Furthermore, the airflow was kept constant for a given EGR level.The engine used in the experiments was a single-cylinder heavy-duty direct injection diesel engine equipped with an electronically controlled unit injector with variable needle opening pressure. Its geometry is based on the Volvo D12C production engine with the compression ratio lowered from 18.5 to 17. The engine is also equipped with a fully flexible pneumatic inlet valve system, enabling both early and late inlet valve closing times and varied swirl levels.The results show that late or early IVC can be used to achieve partially premixed combustion (and thus low soot and NOxemissions) without a fuel consumption penalty.
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| 8. |
- Gjirja, Savo, 1945, et al.
(författare)
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A New Paraffinic Fuel Impact on Emissions and Combustion Characteristics of a Diesel Engine.
- 2002
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Ingår i: SAE Technical Paper Series, Paris. France 2002. ; :2002-01-2218, s. 9-
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Konferensbidrag (refereegranskat)abstract
- Having low aromatic compounds, highcetane rating, higher heat of combustion andalmost zero sulphur content, a new paraffinicfuel (NPF), developed by Oroboros ABSweden, was believed to receive attention as anew alternative fuel. Therefore, furtherinvestigation and combustion analyses wereconducted in a research single-cylinder dieselengine, where detailed thermodynamicanalyses were performed by Burst to File highfrequency signal sampling code and by theDragon software, revealing the realthermochemistry history.The aim of this investigation was aneffort to reduce the pollution levels in Santiagode Chile by introducing this new paraffinic fuel(NPF). Experimental results have shown thatthe NPF fuel has a significant impact not onlyon the emission levels, but also on otherenergetic parameters of the engine such asignition delay, cylinder peak pressure, heatrelease gradient, indicated efficiency etc. It isobserved that NPF fuels have shorter ignitiondelay and longer combustion duration whencompared with those obtained when theengine runs on standard Chilean fuel (SCF) atthe same operating point.As shown by the evaluated rate ofheat release in the premixed zone, the fractionof premixed combustion is larger for CSF fuelthan for NPF fuel. This is an indication forsmooth engine running, lower combustion rate,and lower NOx formation. As a complement tothis, in-cylinder processes with lower peakpressure and earlier location are morefavourable when the engine runs on NPF. Itmay be stated that NPF, which is a selectedoptimised C chain-length variation mixture [2],[3], [4], can be used in unmodifiedcompression ignition engines with significantreduction of regulated emission (NOx, HC, CO,CO2), soot, fuel consumption and smootherthermodynamic characteristics. Therefore, theNPF might be considered as a strongcompetitive alternative fuel.
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| 9. |
- Gjirja, Savo, 1945, et al.
(författare)
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An Experimental Investigation of the SP-700 Oil Additive on a Diesel Engine's Performance and Emissions.
- 1993
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This investigation was carried in the Internal Combustion Engine Laboratory of the Department of Thermo- and Fluid Dynamics at Chalmers University of Technology. The purpose was to investigate the effect of the lubrication oil additive SP-700 on the fuel economy and emission levels of a turbocharged DI diesel engine.The laboratory test engine that was used during this investigation was a six cylinder, direct injected, turbocharged diesel engine. The engine, a VOLVO TD60 B, is rated at 136 kW @ 2800 rpm and 540 Nm @ 1900 rpm.
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| 10. |
- Gjirja, Savo, 1945
(författare)
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Condition Monitoring in Diesel Power Plants with Special Reference to the Supercharging Systems
- 1983
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A recent tendency for research work concerning diesel engine has been concentrated to diagnostic analysis, which intends to detect early adverce influences on engine performance and to conserve the normal conditions of the diesel engine.A diagnostic system is meant to pinpoint the action which should be taken to bring the engine back to standard performance.
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| 11. |
- Gjirja, Savo, 1945, et al.
(författare)
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Considerations on Engine Design and Fuelling Technique Effects on Qualitative Combustion in Alcohol Diesel Engines.
- 1998
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Ingår i: SAE, Society of Automotive Engineers, Inc. 400 Commonwealth Drive Warrendale, PA 15096-0001 USA, October 1998. - 0768003059 ; :982530, s. 175-187
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Konferensbidrag (refereegranskat)abstract
- The paper depicts the main topics of the experimental investigation on alcohol engine development field, aiming at the engineering targets for the emission levels. The first part of this study was focused on engine design optimization for running on ethanol mexed with poly-ethylene glycol (PEG) as ignition improver. It was shown that some design changes in compression ratio, turbine casing, injector nozzle configuration and exhaust pressure governor (EPG) activation, lead to a better engine thermodynamics and thermochemistry. The second objective of this study was the investigation of engine performance and enmission levels, when the ignition improver diethyl ether (DEE) would be generated on board via catalyticallly dehydration of ethanol, and used directly as soluble mixture or separately fumigated. Both alternatives: ether fumigation technique and dissolved ether in alcohol fuel application were conceptually analyzed, and a stand up system based on DEE fumigation was used to determine the optimum DEE-ethanol ratio at any engine operating range. The heat release investigation, when the engine was run on neat ethanol and optimum fumigated DEE, has been indicated earlier combustion, and very short ignition delay. Verified possibilities for using DEE as ignition improver, would lead to a proper version of the on board ether reactor design, which would bring to another solution for ethanol fuelled engines.
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| 12. |
- Gjirja, Savo, 1945, et al.
(författare)
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Development of an Ethanol Fueled Diesel Engine
- 1994
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Ingår i: ISATA, 27th International Symposium on Automotive Technolgy and Automation. 31st October~4th November Aachen, Germany, 1994. ; 27:94EN066, s. 327-334
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Tidskriftsartikel (refereegranskat)abstract
- In order to achieve extensive reduction of the pollutants and appropriate engine performance, an optimization of an ethanol fueled version of the Volvo TD73 diesel engine was performed based on a computerized analysis of measured engine parameters.Using a back pressure regulator, it was possible to obtain an increase of cylinder gas temperature, particularly at light loads, which resulted in a continuous decline in emissions with increase of back pressure. Furthermore, the effects of a by-pass valve, installed between intercooler and intake manifold, was investigated in order to optimize the emission levels.Effects of oxydation catalysts, especially on unregulated emissions such as formaldehyde, acetaldehyde and acetic acid were investigated. In correlation with the back pressure regulator, a fast catalyst warm-up was achieved, and their conversion efficiencies were improved.
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| 13. |
- Gjirja, Savo, 1945, et al.
(författare)
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Development of an Ethanol Fueled Version of the Volvo TD73 Diesel Engine.
- 1994
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Ingår i: VTI och KFB Forskardagar. ; , s. 53-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The continually growing demands over the quality of the environment, followed by the progressive legislation aimed at controlling pollutants, have created a need for a further development of the engine design and the exhaust gas after treatment systems as well.In order to achieve extensive reduction of the pollutants and appropriate engine performance, an optimization of an ethanol fueled version of the Volvo TD73 diesel engine was performed based on a computerized analysis of measured engine parameters.A back pressure regulator (ATR) is mounted on the turbocharger outlet; therefore the engine was forced to work against a back pressure, particularly at light loads where the emission levels are expected to be undesirable. Hence, by reducing air intake, an increase of cylinder gas temperature was certainly expected and a continuous decline in emissions with increase of back pressure was obtained. Furthermore, the effect of a by-pass valve, installed between intercooler and intake manifold, on emission levels were investigated and optimized.Oxidation catalysts effects on regulated emissions, especially unburned fuel, carbon monoxide and unregulated emissions such as formaldehyde, acetaldehyde, and acetic acid were investigated. In correlation with the back pressure regulator, a promoting faster catalyst Warm-up was achieved, and their conversion efficiencies were improved.In order to gain more extensive information to base specification of the engine emissions and catalyst selection, different test cycles such as European R49-13 mode, steady state adoption of the Braunschweig cycle, 24 specific steps cycle, as well as conditioning, activating and transient cycles were used.As a result it has been found that the performance of ethanol engine version was mentained and the significant emissions, well below the goal, were achieved
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| 14. |
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| 15. |
- Gjirja, Savo, 1945, et al.
(författare)
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Diesel Engine Performance in Vector Space as an Actual Evaluating System
- 1983
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- A combination of the measured data from the engine with a mathematical model in terms of the homogeneous deformation theory, leads to appropriate information concerning the running condition of the diesel engine, diagnosis of abnormal conditions and recommendation of appropriate maintenanceThe most reliable data on physical processes and actual conditions of a diesel engine are generally obtained from a monitoring system. Such a system usually gives information about thermal overload, wearing of different parts of the engine, cylinder pressure, fuel pump performance and operating time of injectors. As a complement to monitoring, an investigation of the air gas path system conditions in terms of the deposits in the air filter, air cooler, compressor, turbine, exhaust piping and exhaust boiler is of great interest. A change in any of these deposits is reflected as a change in the thermodynamic properties of the gas flow throughout the whole system of the turbocharged engine. In order to investigate such parameters, the black box method is applied and the engine performance is reflected in vector space.
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| 16. |
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| 17. |
- Gjirja, Savo, 1945
(författare)
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Engine Design Optimization, a Practical Technology for Optimum Performance and Emissions of an Ethanol Fuelled Engine
- 1997
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Ingår i: ISATA, 30th International Symposium on Automotive Technology & Automation, 16th~19th June 1997 Florence, Italy. ; 30:97EL008, s. 435-444
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Tidskriftsartikel (refereegranskat)abstract
- Ethanol, as a very attractive fuel, has been available and studied for years, but being unsutable for most of the diesel engines, is not yet used as primary fuel. However, the engine design optimization, which is discussed in this paper, is found to be a practical technology in order to faciltate the ignition, enhance initial combustion rate and to reduce the emission levels.An acohol engine is expected to be less hot than conventional diesel, hence over penetration might give impingement of liquid fuel on piston crown, which could increase emission of unburned fuel and partially burned species CO. In order to predict the fuel spray impingement and to find the optimum injectors position, a simplified model for the spray tip penetration versus time was performed related to the piston position and injection duration. Also, combustion chamber of reentrant type and straight side wall bowll in-piston type were discussed and tested to prevent the physical reasons for HC and CO formation.Regulated and unregulated emissions were measured according to the different instrumentation as FID, NDIR,CHL,GC,MS using conventional sampling, dinitrophylhydrasine filters,and contaminated distilled water as well.In order to gain acceptance from the public for the ethanol engines with oxidation catalysts, and to increase the understanding of important phenomena in low temperature oxidation of fuels, a substantial information on ethanol oxidation catalysts performance was experienced and possible optimization is discessed.
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| 18. |
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| 19. |
- Gjirja, Savo, 1945, et al.
(författare)
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Ether Fumigation, a New Alternative for the Neat Ethanol Diesel Engine
- 1998
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Ingår i: 31st ISATA, International Symposium on Automotive Technology and Automation, 2nd-5th June 1998 Duseldorf, Germany. ; 31:98EL008, s. 301-309
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Tidskriftsartikel (refereegranskat)abstract
- The main purpose of this study has been to investigate the possibilities off using diethylether (DEE) as ignition improver in an ethanol (EtOH) fuelled Volvo AH10A245 diesel engine, previously optimized to run on ethanol with a polyethylene-glycol ignition improver of trade mark "Beraid".Comparisons between DEE and Beraid is included in the study and it is shown that DEE can be used as excellent cetane enhancer due to the low autoignition temperature.A special fuel system based on DEE-EtOH-H2O fumigation, i.e. a small amount of DEE,EtOH and water fed directly into the inlet air duct, has been designed in order to overcome the problems associated with longer ignition delay when running the engine on DEE-EtOH mixture.The optimum enhancer content during the fumigation tests has been determined according to the engine economy and emission levels. The heat release investigation has indicated earlier combustion, and very short ignition delay. The engine runs smoothely and the peak of the heat release is lower than that obtained when the EtOH-Beraid mixture is used. Extensive increase of the negative work during compression stroke, has been avoided by the fumigation technique. Since the NOx formation rate depends strongly on combustion temperature, the DEE-EtOH mixture has been optimized in respect to low NOx level. It has been observed that HC and CO increase with the fumigation flow and engine load due to overlapping time. It is shown that a reduction of the overlapping time by optimizing the camshaft configuration improve the emissions levels and fuel consumption considerably.
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| 20. |
- Gjirja, Savo, 1945, et al.
(författare)
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Evaluation of the Results of Initial Engine Tests with STID Equipment
- 2001
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The report provides an evaluation of selected cylinder pressure records of a Wärtsilä 320 engine operating according to the STID principle with early, low pressure steam injection, and a discussion of the effects of the steam injection on emissions. It also contains an evaluation of the application potential of low pressure steam injection on engines.Due to pressure limitations of the available boiler, only tests with steam pressures up to 50 bar and steam temperatures up to 320°C could be performed. The steam pressure limitation caused that only injection during the intake stroke and early during the compression stroke was feasible which strongly restricted the scope of the study. However, the research has contributed considerably to the understanding of the STID process and in particular to evaluation of the steam effects on emissions and combustion. The low pressure steam injection is also one of the possible STID application versions to the normal, not thermally upgraded (hot), engines which requires only minor modifications of the steam generating facilities used in current ship installations.It is shown that the ignition and combustion processes in the engine are practically unaffected by injection of the required mass of steam, which typically shall not be larger than 3.5 times the mass of fuel, at which soot, unburned hydrocarbon and CO emissions start to grow. Within this range the NOx emissions can be described by a simple formula NOx =NOx,o(1-0.2m), where m is the steam to fuel mass ratio and NOx,o the emissions of the engine with out steam injection.The optimal way of using low pressure steam is to inject the steam into the inlet manifold of the engine which eliminates the complications of direct steam injection apparatus and eliminates the growth of maximum pressure. The steam temperature shall be as low as possible to minimize the reduction of volumetric efficiency of the engine and to reduce heat losses. The surplus steam enthalpy shall be used to additionally supercharge the engine using an ejector or tangential injection into the impeller of the compressor. It is recommended to utilize the low pressure steam injection on efficiency optimized engines by which both fuel consumption, NOx and soot emission reduction can be achieved
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| 21. |
- Gjirja, Savo, 1945
(författare)
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Experimantal Investigation on Emissions Performance of the Volvo TD73 Engine Running on MK1 and Etamix E15
- 1994
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This test was aimed at investigation of the engine performance and its emissions, when the engine runs on Etamix (El5), as compared to conventiona1 diesel fuel MKl. The method used was engine running according to the specifications of the european test eye le ECE R49. The general performance and exhaust gas emissions of the engine were recorded and evaluated according to the regulations concerning the control of air pollution from heavy duty motor vehicles (A 30 - Regulation).The test engine is a direct injected, turbocharged diesel engine Volvo TD 73. The engine, which is rated at 190 kW at 2200 rpm and 1040 Nm at 1440 rpm, has been recently installed in the engine laboratory test rig of the Thermo and Fluid Dynamics Department.In order to obtain reference data, the engine was run on diesel fuel MK1 and its performance, emissions, and smoke density were recorded for each step of the ECE R49 test cycle. Further, the engine was run on Etamix -15 (Diesel fuel MKl + 15 % Ethanol E 95 + 0.6 % Dalco emulsifier reagent) and the same information as in previous reference test was collected during three different tests. Analyzing these test results, it was observed that NOx levels have a reduction trend compared to emission levels obtained during reference tests on MK1 fuel. On the other hand it was observed that CO emissions were slightly reduced when the engine was run over 50 % load.
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| 22. |
- Gjirja, Savo, 1945
(författare)
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Experimantal Investigation on Engine Emissions Performance of the Volvo TD 60B Engine Running on MK1 as well as on a Mixture of MK1 and Ethanol (E15)
- 1994
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The test was aimed at investigation of the engine performance and its emissions, when the engine runs on E15, as compared to conventional diesel fuel MK1. The method used was engine running according to the specifications of the european test cycle ECE R49. 80th fuels: conventional and E15 were used. The general performance and exhaust gas emissions of the engine were recorded and evaluated according to the regulations concerning the control of air pollution from heavy duty motor vehicles (A 30 - Regulation).The test engine was a direct injected, turbocharged diesel engine Volvo TD 608. The engine, which is rated at 136 kW at 2800 rpm and 540 Nm at 1900 rpm, has been operating for years in the engine laboratory test rig of the Thermo and Fluid Dynamics Department.Running on diesehol fuel E15 with 0.6 % Dalco - E emulsifier reagent, the Volvo TO 60B turbocharged diesel engine maintain a good performance with reduction of the NOx emission levels and smoke density. The expected reduction of HC, ca and specific fuel consumption has, however, not been found.
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| 23. |
- Gjirja, Savo, 1945
(författare)
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Experimental Investigation of the Pilot Injection Effects on Single Cylinder Engine Performance
- 1998
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- A new concept for diesel combustion has been investigated by means of AVL single cylinder engine tests and combustion observations in order to reduce the NOx emission at constant BSFC. The concept is based on pilot injection. In this method, some part of fuel is injected at an early stage, short prior the main injection. It is well known that pilot injection is effective to shorten ignition delay of the main injection. Especially, when the main injection is considerably retarded, pilot injection suppresses the increase in NOx emissions due to the long ignition delay.Engine tests were carried out using a AVL single cylinder research engine at Chalmers University of Technology, Department of Thermo and Fluid Dynamics, equipped with C3EUI and 24 CU ECU via a PC. The pilot injection strategy was to inject a small amount of fuel short prior main injection, such as to be indicated by the needle lift and heat release curve.The experimental results showed that, the trade-off relation of BSFC against NOx emissions with the pilot injection concept is better than those of a conventional injection. The concept of pilot injection seems to interesting for further investigations in connection with compression ignition of lean pre-mixture with multiple injections.
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| 24. |
- Gjirja, Savo, 1945, et al.
(författare)
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Experimental Investigation on the Hydrogen Peroxide Fumigation Into the Inlet Duct of a Diesel Engine
- 2000
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Ingår i: SAE Technical Papers. - 0148-7191 .- 2688-3627. ; SP-1551:2000-01-1919, s. 12-
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Konferensbidrag (refereegranskat)abstract
- Believed to have a potential in reducing the NOxemission level, hydrogen peroxide was fumigated into theinlet duct of the AVL single cylinder research engine via astandard gasoline injector, normally used in the Volvo850-car engine. A small metallic sphere installed 3 cmdownstream the injector tip, improved the spray formationand the uniform distribution of the fumigated peroxidefluid upstream the intake valve. The hydrogen peroxideflow was varied according to the desired value via anelectronic pulse frequency generator.The engine, equipped with an electronic unit injector, wasinitially run without any fumigation fluid until thespecifications of the engine test point were reached andremained very stable. Further, the hydrogen peroxideinjection was activated with three different injection flows,and the engine performance, including emission levels,was compared to reference performance. To avoidsecondary effects on combustion processes andemission levels, the engine was run with the same fuel/airratio.The most expected effect of the hydrogen peroxidefumigation would be on the NOx emission reduction.However, it was observed that other emissions such asCO and HC were remarkably affected as well.Experimental results have shown that the hydrogenperoxide fumigation affects the engine thermochemistry,but not necessarily the fuel consumption and otherenergetic parameters of the engine. However, theincrease of the fumigation flow above a certain limit coulddeteriorate the combustion quality, thereby increase HC,CO and soot formation levels.Nevertheless, heat release and ignition delay, (evaluatedaccording to the “Dragon” software program andacquisition from “Burst to File” PC based samplingsystem)[1], [3] show that the optimal fumigated flow of thehydrogen peroxide might reduce the ignition delay, andthereby significantly improve the engine thermochemistryoutput.Verified effective possibilities for using hydrogen peroxidefumigation, would lead to a proper version of the intakemanifold design, which would bring to another solution forlow emission level diesel engines
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| 25. |
- Gjirja, Savo, 1945, et al.
(författare)
-
Fischer-Tropsch Fuels Impact on a Diesel Engine Performance
- 2000
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Ingår i: ISATA, International Symposium on Automotive Technology and Automation, September 25-27, 2000. Dublin Ireland. ; ISATA 2000:00ELE009, s. 105 -115
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Konferensbidrag (refereegranskat)abstract
- It has been reported that Fischer Tropsch (F-T) diesel fuel is a high quality fuel, and therefore it has received attention as a low emission alternative fuel. Having low aromatic compounds, high cetane rating and almost zero sulfur content, the F-T diesel fuel shows advantages over conventional diesel fuel. However, in order to generalize such deductions and to fill the confirmation gaps, further investigation and combustion analysis have to be conducted.The aim of this investigation was to reveal and analyze the effects of the Fischer-Tropsch (F-T) fuels on a research diesel engine performance. Since the engine performance is closely related to in-cylinder processes, a detailed thermodynamic analysis is performed by Burst to File high frequency sampling code and by the Dragon software, revealing the real thermochemistry history. This program has been tested on thousands of measured points and is today regularly used while analyzing test results from the single cylinder diesel engine. Experimental results have shown that F-T fuels have a remarkable impact not only on the emissions levels, but also on other energetic parameters of the engine. Heat release analysis (evaluated according to the “Dragon” software program and acquisition from “Burst to File” PC based sampling system) have shown that ignition delay, cylinder peak pressure, heat release gradient and indicated efficiency are affected as well.As F-T fuels have some other combustion characteristics than conventional diesel fuels, the most expected effect would be observed on emission levels, particularly on NOx and soot formation. However, it was observed that other emissions such as HC and CO were remarkably affected as well. Also, a combination of the different F-T fuels mixture would lead to a better engine performance and lower emission levels. Therefore, different mixtures of the F-T fuels characterized by C chain-length variation were tested and their results were compared with those obtained from conventional fuel (MK1). The selected optimized F-T fuels mixture was further tested at 13 mode ECE test cycle and is considered as a good competitive alternative diesel fuel.
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| 26. |
- Gjirja, Savo, 1945, et al.
(författare)
-
Fischer- Tropsch-Synthesis Fuels as Diesel Engine Fuel-Fuel of the Future
- 2000
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The Fischer-Tropsch (F-T) catalytic conversion process can be used to synthesize diesel fuels from a variety of feed-stocks, including coal, natural gas and biomass. Synthetic diesel fuels can have very low sulfur and aromatic content, and excellent autoignition characteristics. Moreover, Fischer-Tropsch diesel fuels may also be economically competitive with regular diesel fuel if produced in large volumes.The aim of this investigation is to reveal and analyze the effects of F- T fuels on a research diesel engine performance. Previous engine laboratory tests indicate that F-T fuels are promising alternative fuels because they can be used in unmodified diesel engines, and substantial quantitative exhaust emission reductions can be reached. Also substantial qualitative reductions, e.g. reduction of the number of hazardous chemicals and reduction of the concentration of hazardous chemicals in the exhausts may be realized. Since the engine performance is close1y related to in-cylinder processes, a detailed thermodynamic analysis has been performed revealing the real thermo-chemistry history. The experimental results have shown that F-T fuels have a beneficial effect not only on the emissions levels, but also on other energetic parameters of the engine. Heat release analysis has shown that ignition delay, cylinder peak pressure, heat release gradient and indicated efficiency are affected as well.Two different mixtures of FT-fuels with variation in carbon chain branching and, to a certain extent variation in chain 1ength were tested and their results were compared with those obtained from conventional fuel (MK 1). The selected optimized F-T fuels mixture were further tested according to the 13 mode ECE R49 test cycle and were found as good competitive alternative diesel fuels.
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| 27. |
- Gjirja, Savo, 1945
(författare)
-
Further Simulating Model Calibration According to the Gul Concept
- 1997
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- As in the first part of this study, the engine design of the Gul version is characterized by a cyc1oid crank-connecting rod instead of conventional crankshaft. Thermodynamic cycle simulation shows that the compression line of the Gul engine runs over that of the conventional engine. Under such circumstances, the ignition delay for the Gul engine has to be shorter than that of the conventional engine. This is because of the Gul cycloid characteristics, where the piston moves faster to reach the dead points, and slows down as the piston approaches the TDC or BDC. Hence the ignition and the first phase of the combustion approaches the constant volume process, which would give a higher firing pressure and better efficiency.
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| 28. |
- Gjirja, Savo, 1945, et al.
(författare)
-
Investigation on Methanol Engine with DME Fumigation
- 1999
-
Ingår i: 32nd ISATA International Symposium on Automotive Technology and Automation, 14th-18th June 1999 - Vienna-Austria. ; 32:99CPE029, s. 83-91
-
Tidskriftsartikel (refereegranskat)abstract
- Being a non-soot and low NOx emission level fuel, methanol (MeOH) might be considered as an attractive candidate for use in diesel engine. However, having low cetane number and high heat of vaporization, it is not possible to use in diesel engines without engine modifications. In order to take advantages of the alcohol fuels and to avoid engine complexities, which might come along with such modifications, the use of ignition improver additives dissolved in the base fuel is a normal practice. Another promising solution for qualitative combustion in methanol diesel engines is to design an onboard methanol dehydration reactor which can generate dimethyl ether (DME), for use as ignition improver. As a dissolved mixture MeOH-DME requires a special fuel system, the main emphasis was put on the fumigation technique, where a small quantity of DME has been injected into the inlet duct of the engine and the base fuel (MeOH) is conventionally injected through the common rail pump. A research program was set up for evaluating the effectiveness of DME as ignition improver and to compare results with the conventional additive poly-ethylene-glycol (PEG). The heat release analysis has shown that, the fumigated DME undergoes sufficient combustion during compression stroke. Consequently, the temperature and pressure of the gases in the cylinder increase to the point, where the ignition delay of the base fuel (MeOH) is very short. Such precombustion affects the engine performance and emission output, especially NOx and HC levels. It was generally observed that, the regulated emissions were lower and the engine efficiency slightly higher when compared with those obtained when ethanol (EtOH) mixed with PEG or EtOH with fumigated DEE were used. However, the fumigation tests have shown that running on MeOH fuel, the maximum torque and maximum power could not be reached, as it was expected, due to the limited delivery of flow from the fuel pump.Nevertheless, verified possibilities for using DME as ignition improver in a methanol diesel engine, leads to a proper version of the on-board DME reactor design, which would bring to another solution for methanol fuelled engines.
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| 29. |
- Gjirja, Savo, 1945, et al.
(författare)
-
Investigation on Poly-Ethylene-Glycols (PEG) as Ignition Improvers and Their Effects on Alcohol Engine Performance
- 1998
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this project was to investigate the effects of using some newly developed polyethylene-glycols (PEG) as ignition improvers on Volvo AHI0A245 alcohol engine performance and its emissions. The test engine has previously been optimized to run on ethanol with Beraid (Trade mark of the ignition improver manufactured by the Akzo Nobel Surface Chemistry AB). Hence, the engine design, engine performance, and other functional parameters, which affect the engine thermodynamics and its thermochemistry, have been optimized.To investigate the effects of the different PEG-s on emission levels and engine performance, the fuel injection, particularly injection timing, was optimized for running the engine on ethanol and New PEG (5%), which has replaced the previously developed PEG dissolved with 7% concentration in ethanol. Based on a computerized analysis of measured high frequency signals as cylinder pressure, fuel line pressure, and needle lift related to the crank angles, the injection timing of 12 deg before TDC was found as the optimized value, ( see our previous report No 98/9 " Reference Test with Poly-Ethylene-Glycol (PEG) Ignition Improver"). Other low frequency signals were also analyzed and they were found valuable towards engine performance analysis.
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| 30. |
- Gjirja, Savo, 1945, et al.
(författare)
-
Investigations on Qualitative Combustion in Alcohol Diesel Engines
- 1998
-
Ingår i: Combustion Seminar, Chalmers University of Technology. ; , s. 6-
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A1cohols, (ethanol and methanol), as non soot and low NOx emission level fuels, are attractive candidates for use in diesel engine and therefore, they have inspired many engine researchers. However, having low cetane number, 9 respectively 3, they are not possible to use in diesel engines without engine modifications. ID order to take advantages of the a1cohol fuels and to avoid engine complexities, which might come along with such modifications, the use of ignition improver additives is a normal practice. Poly-ethylene glycol (PEG), which can ease the ignition and enhance initial combustion rate has been intensively used and investigated in two Volvo diesel engines: TD73 for heavy duty trucks and AHIOA245 for buses. Both engines are with direct injection using a torroidal bowl in the piston combustion chamber.The first phase of the development work was concerned on compression ratio, boosting pressure and injection timing. All these were optimized concerning design limits and desired emission levels according to the engineering target. However, the most fundamental effects on emission levels were observed with further engine design optimization in exhaust pressure governor activating pressure, intercooler performance, injector nozzle pattern, injector protrusion and intercooler performance. It was observed that each of them greatly affects emission levels. The EPG activation at light loads can intensively reduce HC and CO leveis, but the engine economy would deteriorate by means of bsfc increasing. An interesting investigation has been on optimal injector protrusion, which might prevent the fuel spray impingement, and by that CO and HC levels.Another promising solution for qualitative combustion in a1cohol diesel engines is to use an on-board reactor to generate ethers from the a1cohol fuel, i.e. from EtOH, diethyl ether (DEE) and from MeOH, dimethyl ether (DMM) may be dehydrated. Both these ethers have high cetane numbers, 90 respectively 60, and may be used as ignition improvers. Therefore, a research program was set up to evaluate the effectiveness of ethers as ignition improvers and compare results with the conventional PEG. At the present stage, the tests have not inc1uded onboard manufactured ethers, instead purchased ether has been premixed with alcohol in the initial tests and injected into the engine air inlet during the fumigation tests. The main emphasis has been put on the fumigation technique, where a mixture of ether, alcohol and water has been used in order to simulate the output from a dehydration reactor.Verified possibilities for using ethers as ignition improvers would lead to a proper version of the onboard ether reactor design, which would bring to another solution for alcohol fuelled engines.
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| 31. |
- Gjirja, Savo, 1945
(författare)
-
Literature Review and Suggestions on Alcohol Engines with Ether as Ignition Impropvers
- 1996
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The ignition improvers available on the market are rather expensive, toxic and, as expected, highly explosive. They are normally used in two different ways: mixed directly into the base fuel leading to a soluble fuel or fed separately into the engine. A suitable emulsifying agent is often required when the soluble fuel is considered. Considering the latter possibility, the two fuel system is more complex and costly, and therefore not so commonly used. In order to use the ignition improvers sufficiently they have to meet some requirements, especially with regards to the minimum admixture quantity, sufficient solubility and storability in alcohol, lubricating properties, minimum toxicity etc. Dissolved ignition improvers as “Beraid” or “Avocet” have been successfully used in Volvo and Scania diesel engines. Different investigations and engine design optimizations for running on ethanol with beraid. as ignition improver have been done at the Department of Thermo and Fluid Dynamics (CTH) through different projects and studies. The results of these studies are reported in different publications of the Swedish Transport & Communications Research Board (KFB) and CTH- TFD internai papers. This possibility to use ethers, such as Dimethyl Ether (DME) and Diethyl Ether (DEE), when running the engine on methanol and ethanol respectively, was studied and followed up with an experimental project in a modified alcohol engine Volvo AH10A245. The aim of the project was to verify the possibility to use ethers, from an economical point of view, instead of ignition improvers. If a positive result is achieved, the possibility to generate ethers in an onboard reactor will be considered. DME can be easily produced by the exothermic dehydration of methanol over an acid catalyst according to the reaction
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| 32. |
- Gjirja, Savo, 1945, et al.
(författare)
-
Measurements and Prediction of the GUL Engine Emissions by the Two Zone Combustion Model
- 1997
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this study was to investigate the trend of the engine emissions according to the Gul & Co - Motor development using cycloid crank-connecting rod instead of the conventional crankshaft. Information from the tests of the Husqvarna Engine Research and constructive information from an Italian engine have been used as the reference performance of the conventional engine. Furthermore, the investigation of the emissions performance of a Gul size engine with conventional crankshaft would be helpful to complete the information on trend of the emissions prediction for the Gul engine.In order to come closer to the real emissions prediction, a two zone combustion model has been developed. Since the two zone model considers unburned and burned gases, the trend of the cylinder gas temperature for burned zone is different from that of the mean gas temperature, which reaches its maximum later than the burned zone. Hence, NOx and CO emissions, which are strongly affected by the temperature, would be more realistic if the emissions formation is calculated according to the thermodynamic properties from the burned zone. This model gives information on unburned and burned gas temperature, NO formation rate, equilibrium mole fraction for the NO at local conditions, average mole fraction at the exhaust etc.
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| 33. |
- Gjirja, Savo, 1945, et al.
(författare)
-
On-Board Manufactured Ethers as an Ignition Improver for Alcohol Engines (Sub-Project)
- 1998
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Alcohol fuels, ethanol or methanol, have low cetane number, 9 respectively 3, and are therefore not possible to use in diesel engines without engine modifications. Normal practice is to add an ignition improver to the alcohol fuel. Ignition improvers available on the market are rather expensive and are normally mixed directly into the alcohol fuel. An early concept was to inject a small amount of diesel fuel into the cylinders before injecting the alcohol. This gives satisfactory operation but requires two fuel injection systems which increase cost and maintenance.Dissolved ignition improvers of type polyethylene glycoI (PEG) are used in Scania and Volvo engines with good success but alternative additives are of interest to investigate. A prornising solution is to use an on-board reactor to generate ethers from the alcohol fuel. From ethanol (EtOH), diethyl ether (DEE) may be dehydrated and from methanol (MeOH), dimethylether (DME) may be dehydrated. Both these ethers have high cetane numbers, 90 respectively 60, and may be used as ignition improvers.This research program has been set up to evaluate the effectiveness of ethers as ignition improvers and compare the results with the conventional PEG improvers. The project was approved by the Combustion Engine Research Center (CERC) at the board meeting 1996-0] -30 and has been performed at the Department of Thermo and Fluid Dynamics. Within CERC, the partners Scania and Volvo LV have been co-sponsoring the project from the start and Aspen Petroleum. An external interested party, the Swedish Transport & Communications Research Board (KFB), has co-sponsored the ethanol part of the project. Part of the funding comes from NUTEK and CTH as partners in CERC
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| 34. |
- Gjirja, Savo, 1945, et al.
(författare)
-
Performance and Emission Analysis of a Non-Conventional Gasoline Engine
- 2000
-
Ingår i: SAE Technical Papers. - 0148-7191 .- 2688-3627. ; Vol. 109, No 4:2000-01-1840, s. 1104-1116
-
Konferensbidrag (refereegranskat)abstract
- A new engine design concept, characterized by a singlecylinder-double piston and a cycloid crank rotor insteadof the conventional crankshaft has been developedrecently by Gul & Co Development AB, Sweden. Therotor (crank disc) is equipped with an oval groove in theshape of a sinusoidal cycloid according to the expressionY=S(-Sin(2)/(2)) where S is the piston stroke and varies from 0 to 1. Inside the oval groove a ball rolls/slides in order to transfer force from the piston to therotor. Such a rotor contains groove surfaces for the valvemovement control as well. Each turn of the rotorcorresponds to four strokes for both the pistons. Thus, afull 4-stroke engine cycle is developed for a single nonconventionalcrankshaft revolution.Having the extra freedom to select an optimal pistonmovement, the new design is believed to have thepotential to provide low emissions, low noise levels andlower fuel consumption. Therefore, it has been subjectedto an engine thermodynamics simulation, to provide aninsight to engine performance.Simulation results and preliminary laboratory tests haveshown that the optimized cycloid crank rotor, whichfurther intensifies the reduction of the piston speed closeto both dead centers, gives better conditions for thecombustion processes, and thus a higher efficiency.Since the single cylinder-double piston with cycloid crankrotor displays better performance and reduced sizecompared to conventional combustion engines, it isbelieved that this new patented Swedish engine willcompete with conventional engines in lawn movers, chainsaws, outboard motors and other engines in similarsmall-scaled equipment.
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| 35. |
- Gjirja, Savo, 1945, et al.
(författare)
-
Performance simulation of a non conventional gasoline MOD engine
- 2009
-
Ingår i: SAE Technical Papers. - Warrendale, PA : SAE International. - 0148-7191 .- 2688-3627.
-
Konferensbidrag (refereegranskat)abstract
- A new engine design concept, characterized by torroidal cylindrical cross section cylinders and rotating disc shape flat pistons instead of the conventional design has been developed by Markus Olofsson, Sweden. Such engine has neither crankshaft, nor connecting rods. A rotor in shape of the half-cylindrical torroid is covered by the other half of the static cylindrical torroid forming a new design for the combustion chamber. Such rotor is equipped with a fixed disc shape flat piston, while the other half-static torroid has a groove channel. Inside the groove a disc shape wall (which serves as a movable cylinder head) slides up and down in order to allow the bypass of the piston. The half-static torroid contains four different valve series for fresh air at low pressure, for air mixture at high pressure, for exhaust process and for high-pressure receiver filling. Each turn of the rotor (equipped with rotating piston) corresponds to four virtual stroke processes. Thus, a full engine cycle is developed for a single non-conventional driving shaft revolution. Having separate combustion and compression chambers at both sides of the flat piston, the new design is believed to have the potential to provide typical engine performance. Therefore, it has been subjected to an engine thermodynamics simulation, to provide an insight to engine performance. Simulation results and preliminary evaluations have shown that the further work for optimization of the torroid-rotating piston engine parameters might lead to a compact and lower friction engine. Lower friction performance might be due to the crankshaft and connecting rod missing, which are normally the main components for the friction losses. Further reduction of the friction losses might come from the rotating pistons, which do not have any side force as in the conventional reciprocating engine. Therefore, the new developed design would lead to the reduction of the engine vibrations and noise level. Since the torroidal cylinder-rotating piston engine promises to display good performance and reduced size compared to conventional combustion engines, the new engine design concept should be further investigated and compared with other conventional engines.
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| 36. |
- Gjirja, Savo, 1945
(författare)
-
Some Considerations About Gas-Fuel Flow Evaluation in a Marine Turbocharged Diesel Engine
- 1982
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The amount of gas flow delivered by the turbocharger is a very important parameter for diesel performance evaluation. Insufficient air flow to the cylinders is frequently the main reason of anomalies in the combustion process, exhaust gas temperature, and consequently in thermal efficiency of diesel engines. Therefore, concerning the actual condition analysis of a diesel engine, there is room to discuss the methods for evaluation of the gas flow through turbochargers.On the other hand the amount of fuel delivered by fuel pump, indicates the amount of heat released inside the cylinders for normal combustion conditions; consequently, it has a great influence on diesel thermodynamic cycles. From this point of view, the diagnostic analysis system and diesel performance evaluation necessitate an accurate estimation of the fuel amount.
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| 37. |
- Gjirja, Savo, 1945, et al.
(författare)
-
The Trend of the Engine Performance According to the Gul-Motor Development
- 1997
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this study was to investigate the trend of the engine performance according to the Gul & Co - Motor development using cycloid crank-connecting rod instead of the conventional crankshaft. Since the Gul & Co motor aims at the double piston engine with stroke reduction, a preliminary investigation of the Gul & Co concept, including the piston stroke effect on the engine performance is needed. Furthermore, the investigation of the general performance of a double piston engine with diameter reduction would give a helpful additional infoffi1ation.In order to further evaluate the Gul & Co concept, a preparatory approximation of the engine design by using the cycloid crank-connecting rod instead of conventional crankshaft is needed, and the engine performance comparison should be performed.The method used was the simulation of the engine performance by using non dimensional Filling-Emptying model. In its basic form, this model requires the rate of combustion as an input to the calculation. However, such model allows general engine design changes to be investigated with moderate computational requirements.The cycle simulation is designed to predict details of the thermodynamic properties of the working fluid and general engine performance over a broad range of operating and design conditions, including valve timing, spark ignition timing, engine cooling conditions etc
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| 38. |
|
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| 39. |
- Gjirja, Savo, 1945
(författare)
-
Turbocharged Diesel Engine with Exhaust Gas Pulsation
- 1981
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In the naturally-aspirated diesel engine the density of the induced air is almost equal to the local air density. From this point of view the maximum weight of fuel that can be burnt efficiently is determined, therefore, the maximum power as well. If the density of charge air can be increased, then the weight of the charge air can also be increased, with a proportional increase in power. The large turbocharged diesel engine are designed with gas pulsation turbocharger. When the exhaust valve opens, the exhaust gas pressure is higher than scavenging pressure and after the initial rise of the exhaust valves, the pressure falls below the scavenging pressure. Therefore, the high energy exhaust pulses into turbine can be utilized to achieve better and effective scavenging.
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| 40. |
- Gjirja, Savo, 1945, et al.
(författare)
-
Wood Powder Injection in a Single Cylinder of the Volvo D16 Diesel Engine and its Thermodynamics Performance
- 2000
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this investigation was to reveal and analyze the effects of the wood powder injection in a single cylinder of the 6 cylinder Volvo Dl6 diesel engine performance. Since the engine performance is c1osely related to in-cylinder processes, a detailed thermodynamic analysis is performed by Burst to File high frequency sampling code and by the Dragon software program, revealing the real cylinder thermodynamics history. This program has been tested on thousands of measured points and is today regularly used while analyzing test results from the diesel engine. Cylinder pressure and heat release analysis lead to a valuable information on ignition delay, cylinder peak pressure, heat release gradient, indicated efficiency and many other parameters of the engine thermodynamics.
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| 41. |
- Husberg, Tobias, 1975, et al.
(författare)
-
Combustion phasing and emission control by using multiple injections on a Heavy-Duty Diesel engine.
- 2005
-
Ingår i: Fifth Symposium Towards Clean Diesel Engines, Lund Institute of Technology, Lund, Sweden.
-
Konferensbidrag (refereegranskat)abstract
- Very early injection strategies are used to get more premixed combustion the level of EGR must be increased substantially to suppress NOx formation and ignition delay at higher loads. This normally leads to higher equivalence ratio and poor energy conversion efficiency thus higher fuel consumption. When less EGR are used, to be able to keep the fuel consumption on an acceptable level, the mixture ignites too early and NOx levels become very high when all the fuel is injected early. This leads to a combination of early injections and more conventional injection timing. A diesel combustion where all fuel is premixed before it is burned suffers from combustion phasing control problems at higher loads; the heat release is too early. One way to delay ignition and improve phasing is to substitute fresh air with EGR. This is possible to some extent for low loads and light duty. But no publication has shown high EGR usable for high load in a heavy-duty application. Combustion mode shift can be a possible way to reach higher loads, a change to more conventional diesel combustion at high loads. But the inertia of the gas leads to difficulties going from one mode to another, when EGR levels needs to be changed rapidly. By using multiple injections strategies the combustion rate can be phased and the ignition controlled. Combined with high EGR levels and lean mixtures low emission output can be achieved. Multiple injections allow control over how much fuel that is burned at premixed conditions and how much is burned at more diffusion like conditions.
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| 42. |
- Husberg, Tobias, 1975, et al.
(författare)
-
Fuel Equivalence Ratio and EGR Impact on Premixed Combustion Rate and Emission Output, on a Heavy-Duty Diesel Engine.
- 2005
-
Ingår i: 7th International Conference on Engines for Automobile, SAE Naples section, Capri (Naples) - Italy.
-
Konferensbidrag (refereegranskat)abstract
- This study aims to show how both NOx and soot areaffected by EGR dilution when constant, as well asvariations in equivalence ratio is applied together withmultiple injection strategies.Experiments were conducted in a single cylinder heavyduty research engine. The effects of both EGR andequivalence ratio on partly premixed combustion wereinvestigated. Multiple injections strategies werecombined with high EGR levels and lean mixtures.Multiple injections were used to control the combustionphasing and the level of the premixed combustion rate.The diesel combustion conditioning by means ofpremixed combustion rate, EGR level and oxidantequivalence ratio, leads to low engine emissions. In theload range and configuration tested, emission levelsbelow future emission standards e.g. EURO V havebeen shown, with no BSFC penalty or exhaustaftertreatment.
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| 43. |
- Husberg, Tobias, 1975, et al.
(författare)
-
Piston temperature measurement by use of thermographic phosphors and thermocouples in a heavy-duty diesel engine run under partly premixed conditions
- 2005
-
Ingår i: SAE Technical Papers. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International. - 0148-7191 .- 2688-3627.
-
Tidskriftsartikel (refereegranskat)abstract
- Piston temperature experiments were conducted in a single-cylinder heavy-duty Diesel research engine, based on the Volvo Powertrain D12C engine both by use of optical temperature sensitive phosphor and of thermocouples mounted on the piston surface. In the former case, a thin coating of a suitable thermographic phosphor was applied to the areas on the piston surface to be investigated. The optical measurements of piston temperatures made involved use of an optical window and of an endoscope. The possibility of using optical fibres into guide light in and out of the engine was also investigated. Results of the optical and of the thermocouple measurements were compared and were also related to more global data with the aim of exploring the use of thermographic phosphors for piston- temperature measurements in Diesel engines. Thermographic phosphors thermometry was found to represent an alternative to the thermocouple method since it easily can be applied to various piston geometries. The method was seen to have a clear potential for production-type engine applications, particularly with use of fibre optics. Copyright © 2005 SAE International.
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| 44. |
- Husberg, Tobias, 1975, et al.
(författare)
-
Piston Temperature Measurement by Use of Thermographic Phosphors and Thermocouåles in a Heavy-Duty Diesel Engine Run Under Partly Premixed Conditions
- 2005
-
Ingår i: SAE, Technical Paper Series, 2005. ; :2005-01-1646, s. 11-
-
Konferensbidrag (refereegranskat)abstract
- Piston temperature experiments were conducted in a single-cylinder heavy-duty diesel research engine both by use of optical temperature sensitive phosphor and of thermocouples mounted on the piston surface. In the former case, a thin coating of a suitable thermographic phosphor was applied to the areas on the piston surface to be investigated. The optical measurements involved the use of an optical window and of an endoscope. The possibility of using optical fibres into guide light in and out of the engine was also investigated. Results of the optical and of the thermocouple measurements were compared and were also related to more global data with the aim of exploring the use of thermographic phosphors for piston-temperature measurements in diesel engine. Thermographic phosphors thermometry was found to represent an alternative to the thermocouple method since it easily can be applied to various piston geometries.
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| 45. |
- Husberg, Tobias, 1975, et al.
(författare)
-
Visualization of Egr Influence on Diesel Combustion With Long Ignition Delay in a Heavy-Duty Engine
- 2004
-
Ingår i: SAE Technical Paper Series, SP-1896, 2004. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International. ; :2004-01-2947, s. 10-
-
Konferensbidrag (refereegranskat)abstract
- The effects of EGR on diesel combustion were visually examined in a single-cylinder, heavy-duty research engine with a low compression ratio, low swirl, a CR fuel injection system and an eight-orifice nozzle. Optical access was primarily obtained through the cylinder head. The effects of EGR were found to be significant. NOx emissions were reduced from over 500 ppm at 0% EGR to 5 ppm at 55% EGR. At higher levels of EGR (approximately 35% or more) there was a loss in efficiency. Constant fuel masses were injected. Results from the optical measurements and global emission data were compared in order to obtain a better understanding of the spray behavior and mixing process. Optical measurements provide fundamental insights by visualizing air motion and combustion behavior. The NOx reductions observed might be explained by reductions in oxygen concentration associated with the increases in EGR.
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| 46. |
- Johansson, Monica, 1979, et al.
(författare)
-
Effects of Varying Engine Settings on Combustion Parameters, Emissions, Soot and Temperature Distributions in Low Temperature Combustion of Fischer-Tropsch and Swedish Diesel Fuels
- 2009
-
Ingår i: SAE 2990 Powertrains, Fuels and Lubricants Meeting. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International.
-
Konferensbidrag (refereegranskat)abstract
- It has been previously shown that engine-out soot emissions can be reduced by using Fischer-Tropsch (FT) fuels, due to their lack of aromatics, compared to conventional Diesel fuels. In this investigation the engine-out emissions and fuel consumption parameters of an FT fuel derived from natural gas were compared to those of Swedish low sulfur diesel (MK1) when used in Low Temperature Combustion mode in a single cylinder heavy-duty diesel engine. The effects of varying Needle Opening Pressure (NOP), Charge Air Pressure (CAP) and Exhaust Gas Recirculation (EGR) according to an experimental design on the measured variables were also assessed. CAP and EGR were found to be the most significant factors for the combustion and emission parameters of both fuels. Increases in CAP resulted in lower soot emissions due to enhanced charge mixing, however NOx emissions rose as CAP increased. In contrast to the effects of CAP, as the EGR level rose from 0% to around 50% the soot emissions increased and the NOx emissions decreased. However, at approximately 50% EGR the soot emissions started to decrease again because the soot formation zone was avoided since there was less available oxygen (and hence lower in-cylinder temperatures). The effects of increasing NOP were similar, but weaker, to those of increasing CAP. In contrast to previous studies, in which FT yielded lower soot emissions, it was observed in this study that FT fuel yielded higher soot emissions at high EGR levels (above 40%) than MK1. An AVL visioscope 1.1 was installed in the test engine to measure instantaneous temperatures and soot concentrations in the cylinder during combustion. The results showed that the FT fuel yielded lower soot concentrations than MK1 at low EGR levels.
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| 47. |
- Johansson, Monica, 1979, et al.
(författare)
-
NOx and soot emissions trends for RME, SME and PME fuels using engine and spray experiments in combination with simulations
- 2013
-
Ingår i: Fuel. - : Elsevier BV. - 0016-2361. ; 106, s. 293-302
-
Tidskriftsartikel (refereegranskat)abstract
- This study includes engine tests with neat FAME fuels and blends of 7% and 30% of RME in European Diesel, EN590 (non FAME added). The study was also completed with spray studies and numerical simulations for a deeper understanding of the engine results.The engine was operated at four operational points (A25, B50, B75 and C100) taken from the European Stationary Cycle, ESC cycle. The A25 case was also extended to achieve information how the soot emissions varies with the operational parameters; start of injection (SOI), NOx level (regulated by EGR) and needle opening pressure (NOP). The spray studies were performed in a high temperature/high pressure spray chamber at relevant conditions. For the numerical simulations the KIVA 3-V code was used with detailed chemical kinetics.The results shows that the neat FAME fuels lower the soot emissions by up to 90% compared with Diesel fuel. Moreover, even low blend ratios lowers the soot emissions significantly. Among the FAME fuels, combustion with PME had the lowest amount of soot emissions due to its lowest amount of di-and tri-unsaturated fatty acids (i.e. less double bonds) in comparison with SME and RME.The NOx emissions were increased for the neat FAME fuels in relation the Diesel fuel. The increase in NOx emissions for the neat FAME fuels is due to the higher flame temperature for the FAME fuels which could be a result of the oxygen content which causes a lower equivalence ratio (phi), i.e. leaner local reacting mixture.The A25 operational case showed that the most important factor to decrease soot emissions for Diesel fuel was NOP, while for the FAME fuels SOI had the greatest impact. Further, at constant level of NOx emissions for the included fuels it was observed that the FAME fuels still reduced the soot emissions significantly.The study shows that FAME fuels and Diesel blends with FAME fuels, can be a tool to meet future emission legislation, since low soot emissions levels can be reached for low NOx emissions and the fact that FAME fuels are renewable, the global warming impact is lower than for Diesel.
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| 48. |
- Lif, Anna, 1962, et al.
(författare)
-
Reduction of soot emissions when combusting water-in-diesel emulsion and microemulsion fuel in a direct injection diesel engine
- 2007
-
Ingår i: SAE Technical Paper. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International. - 0148-7191.
-
Tidskriftsartikel (refereegranskat)abstract
- The emissions from a direct injection diesel engine measured according to the ECE R49 13-mode cycle and as a function of exhaust gas recirculation are compared for diesel fuel without water addition, and for water-in-diesel as emulsion and microemulsion. The effect of water addition on the soot emissions was remarkably strong for both the emulsion and microemulsion fuels. The average weighted soot emission values for the 13-mode cycle were 0.0024 and 0.0023 g/kWh for the two most interesting emulsion and microemulsion fuels tested, respectively; 5-fold lower than the US 2007 emission limit.
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| 49. |
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| 50. |
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