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On the Impact of Piston Motion and In-Cylinder Charge Composition on Energy Release, Auto Ignition and Emission Formation in Premixed Charge Internal Combustion Engines

Stenlåås, Ola LU (2004)
Abstract (Swedish)
Popular Abstract in Swedish

Avhandlingen pressenterar resultat från fyra studerade områden; En undersökning av hur nya kolvrörelser (volym-vevvinkel relationer) påverkar utsläpp, effekt och verkningsgrad; En undersökning av hur kväveoxid påverkar självantändning och knack; En undersökning av hur vätgas och reformerad metanol (RMG) kan utnyttjas som bränsle, dels i vanliga tändstiftsantända (SI) motorer, dels i kompressionsantända (HCCI) motorer; Resultat från mjukvaruutveckling av ett zonbaserat motorsimuleringsprogram med detaljerad kemisk kinetikberäkning.



Mjukvaruutvecklingen av programmet för kemisk kinetikberäkning inriktades på att möjliggöra modellering av alla motorns fyra slag. Modeller för... (More)
Popular Abstract in Swedish

Avhandlingen pressenterar resultat från fyra studerade områden; En undersökning av hur nya kolvrörelser (volym-vevvinkel relationer) påverkar utsläpp, effekt och verkningsgrad; En undersökning av hur kväveoxid påverkar självantändning och knack; En undersökning av hur vätgas och reformerad metanol (RMG) kan utnyttjas som bränsle, dels i vanliga tändstiftsantända (SI) motorer, dels i kompressionsantända (HCCI) motorer; Resultat från mjukvaruutveckling av ett zonbaserat motorsimuleringsprogram med detaljerad kemisk kinetikberäkning.



Mjukvaruutvecklingen av programmet för kemisk kinetikberäkning inriktades på att möjliggöra modellering av alla motorns fyra slag. Modeller för variabel massa i cylindern, gasflöde genom ventiler och blandning av gas, både i och utanför cylindern, implementerades. Också ekvationslösningsalgoritmen utvecklades så modellen klarar flerzonsberäkningar.



Kväveoxid befanns, både i en modelleringsstudie och i en experimentell studie, ha en inverkan på självantändning och knack. Modelleringsstudien visade att kväveoxid har en maximal knackframkallande nivå på 500 ppm. Den experimentella studien visade att ökad mängd kväveoxid ökar knackintensiteten i motorn, men inget maximum hittades.



Kompressions- och tändstiftsantända motorer drivna med förblandad väte-luft eller RMG-luft blandning studerades med avseende på operationsområde, effekt, verkningsgrad och utsläpp. För tändstiftsantänd motor togs dessutom en empirisk flamhastighetsmodell fram. Vid undersökningen av verkningsgrad beaktades reformationsprocessen som framställer vätgas eller RMG ur metanol. Operationsområdet för de två bränslena befanns vara begränsat till magra blandningar och motoreffekten var ungefär hälften av den som motsvarande motor presterar med normala bränslen men den indikerade verkningsgraden var hög. Vid kompressionsantändning var utsläppen av kväveoxider låga men förbränningsverkningsgraden sjönk då blandningen blev magrare vilket resulterade i höga utsläpp av oförbränt bränsle.



Undersökningen av nya kolvrörelser visade att varken verkningsgrad eller effekt påverkades i någon större utsträckning av kolvrörelsen så länge expansionsförhållandet hålls konstant. Utsläpp av kväveoxider och kolmonoxid påverkades av kolvrörelsen men inte i en utsträckning att konceptet utgör ett alternativ till katalysatorrening av avgaserna. (Less)
Abstract
The results presented in this thesis can be divided into four areas of investigation: Investigation of the effect of new volume-crank angle relations on engine emissions, power and efficiency; investigation of nitrogen oxides effect on auto ignition and knock in SI engines; investigation of premixed SI and HCCI engine operation with the alternative fuels hydrogen and reformed methanol gas (RMG); software development of a detailed chemical kinetics zonal engine model.



Model development of the in-house two-zone chemical kinetic code focused on expansion of the Jacobian matrix to allow simulations of variable in-cylinder charge. Addition of engine simulation sub-routines to achieve full cycle simulation capacity were made.... (More)
The results presented in this thesis can be divided into four areas of investigation: Investigation of the effect of new volume-crank angle relations on engine emissions, power and efficiency; investigation of nitrogen oxides effect on auto ignition and knock in SI engines; investigation of premixed SI and HCCI engine operation with the alternative fuels hydrogen and reformed methanol gas (RMG); software development of a detailed chemical kinetics zonal engine model.



Model development of the in-house two-zone chemical kinetic code focused on expansion of the Jacobian matrix to allow simulations of variable in-cylinder charge. Addition of engine simulation sub-routines to achieve full cycle simulation capacity were made. The routines added handle flow through valves and both internal and external residual gas mixing. Also expansion of the solver and development of the code to achieve multi-zone capacity was made.



Nitric oxide was, both in a modeling study and in an experimental study, found to have an impact on auto ignition. The modeling study showed a maximum auto ignition promoting effect at 500 ppm. The experimental study showed increased knock intensity when NO was added but no maximum promoting effect was noted.



Premixed engine HCCI and SI operation fuelled with hydrogen and RMG was analyzed from operating range, power, efficiency and emission perspectives. For the SI cases empirical flame speed expressions based on the engine related parameters lambda, engine speed, minimum cylinder height and ignition angle were developed. In the efficiency discussions the reformation of methanol to hydrogen or RMG is taken into account. The range of operation was limited to lean combustion. Engine power when using the investigated fuels was found to be limited to about half of what is achievable in premixed operation on other fuels. Indicated efficiencies were found to be high and the emissions of NO from the HCCI operated engine were low but the low combustion efficiency at high lambdas resulted in high amounts of unburned fuel in the exhaust gas.



Modeling of new relations of volume-crank angle dependence was made. The efficiency and the power of the engine modeled were not altered in any major way by changes in the volume-crank angle dependence as long as the expansion ratio was held constant. Engine emission of NO and CO could be altered by changes in the volume-crank angle dependence but the changes were not of the magnitude that the concept can replace the catalyst used to lower emissions from engines today. (Less)
Please use this url to cite or link to this publication:
author
opponent
  • Professor Taylor, Alex, England
organization
publishing date
type
Thesis
publication status
published
subject
keywords
bränslen, sprängämnen, Carbochemistry, petrochemistry, fuels and explosives technology, Petrokemi, Internal Combustion Engine, Emission, SI, Spark Ignition, HCCI, Homogeneous Charge Compression Ignition, zone model, Chemical Kinetic, Engine simulation, Reformed Methanol, Hydrogen, Knock, Auto Ignition, NO, Piston Motion, Nitric Oxide, Premixed Charge
pages
208 pages
defense location
Lund Institute of Technology.
defense date
2004-10-22 10:15
external identifiers
  • Other:ISRN:LUTMDN/TMHP--04/1024—SE
ISSN
0282-1990
ISBN
91-628-6252-9
language
English
LU publication?
yes
id
7dfeeefb-77a3-4f4c-bff5-951ea7e9632d (old id 467388)
date added to LUP
2007-09-10 14:34:20
date last changed
2016-09-19 08:45:01
@phdthesis{7dfeeefb-77a3-4f4c-bff5-951ea7e9632d,
  abstract     = {The results presented in this thesis can be divided into four areas of investigation: Investigation of the effect of new volume-crank angle relations on engine emissions, power and efficiency; investigation of nitrogen oxides effect on auto ignition and knock in SI engines; investigation of premixed SI and HCCI engine operation with the alternative fuels hydrogen and reformed methanol gas (RMG); software development of a detailed chemical kinetics zonal engine model.<br/><br>
<br/><br>
Model development of the in-house two-zone chemical kinetic code focused on expansion of the Jacobian matrix to allow simulations of variable in-cylinder charge. Addition of engine simulation sub-routines to achieve full cycle simulation capacity were made. The routines added handle flow through valves and both internal and external residual gas mixing. Also expansion of the solver and development of the code to achieve multi-zone capacity was made.<br/><br>
<br/><br>
Nitric oxide was, both in a modeling study and in an experimental study, found to have an impact on auto ignition. The modeling study showed a maximum auto ignition promoting effect at 500 ppm. The experimental study showed increased knock intensity when NO was added but no maximum promoting effect was noted.<br/><br>
<br/><br>
Premixed engine HCCI and SI operation fuelled with hydrogen and RMG was analyzed from operating range, power, efficiency and emission perspectives. For the SI cases empirical flame speed expressions based on the engine related parameters lambda, engine speed, minimum cylinder height and ignition angle were developed. In the efficiency discussions the reformation of methanol to hydrogen or RMG is taken into account. The range of operation was limited to lean combustion. Engine power when using the investigated fuels was found to be limited to about half of what is achievable in premixed operation on other fuels. Indicated efficiencies were found to be high and the emissions of NO from the HCCI operated engine were low but the low combustion efficiency at high lambdas resulted in high amounts of unburned fuel in the exhaust gas.<br/><br>
<br/><br>
Modeling of new relations of volume-crank angle dependence was made. The efficiency and the power of the engine modeled were not altered in any major way by changes in the volume-crank angle dependence as long as the expansion ratio was held constant. Engine emission of NO and CO could be altered by changes in the volume-crank angle dependence but the changes were not of the magnitude that the concept can replace the catalyst used to lower emissions from engines today.},
  author       = {Stenlåås, Ola},
  isbn         = {91-628-6252-9},
  issn         = {0282-1990},
  keyword      = {bränslen,sprängämnen,Carbochemistry,petrochemistry,fuels and explosives technology,Petrokemi,Internal Combustion Engine,Emission,SI,Spark Ignition,HCCI,Homogeneous Charge Compression Ignition,zone model,Chemical Kinetic,Engine simulation,Reformed Methanol,Hydrogen,Knock,Auto Ignition,NO,Piston Motion,Nitric Oxide,Premixed Charge},
  language     = {eng},
  pages        = {208},
  school       = {Lund University},
  title        = {On the Impact of Piston Motion and In-Cylinder Charge Composition on Energy Release, Auto Ignition and Emission Formation in Premixed Charge Internal Combustion Engines},
  year         = {2004},
}