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The Performance of a Multi Cylinder HCCI Engine using Variable Compression Ratio and Fast Thermal Management

Hyvönen, Jari LU (2005)
Abstract (Swedish)
Popular Abstract in Swedish

Förbränningsmotor är i dagens värld den mest använda kraftkällan för fordon. Förbränningsmotorn har kontinuerligt utvecklats och förbättrats sedan Nicolaus August Ottos och Rudolf Diesels dagar, och kommer att fortsätta att utvecklas långt in i framtiden. Ingen konkurrerande teknik har ännu på allvar utmanat förbränningsmotorns ställning. Det finns en lång rad tänkbara kandidater, men de måste först visa sin verkliga kapacitet i praktiken innan de kan komma till större användning. Många nya teknologier som förbättrar förbränningsmotorns användning har dykt upp på senare år, tex. hybrider. Dessa nya teknologier utnyttjar förbränningsmotorn där den är som bäst och undviker dess nackdelar, dvs. där... (More)
Popular Abstract in Swedish

Förbränningsmotor är i dagens värld den mest använda kraftkällan för fordon. Förbränningsmotorn har kontinuerligt utvecklats och förbättrats sedan Nicolaus August Ottos och Rudolf Diesels dagar, och kommer att fortsätta att utvecklas långt in i framtiden. Ingen konkurrerande teknik har ännu på allvar utmanat förbränningsmotorns ställning. Det finns en lång rad tänkbara kandidater, men de måste först visa sin verkliga kapacitet i praktiken innan de kan komma till större användning. Många nya teknologier som förbättrar förbränningsmotorns användning har dykt upp på senare år, tex. hybrider. Dessa nya teknologier utnyttjar förbränningsmotorn där den är som bäst och undviker dess nackdelar, dvs. där den har dåligt verkningsgrad.



På grund av det stora antalet förbränningsmotorer i världen är inte deras miljöpåverkan acceptabel. Avancerad motorstyrning och avgasefterbehandling har minskat utsläppen av de reglerade emissionerna; NOx, CO, HC, och partiklar, till mycket låga nivåer. Kommande lagstiftning kommer att sänka emissionerna ytterligare. Trots detta är och kommer utsläppen av växthusgasen CO2 från förbränningsmotorn att vara ett problem i framtiden. Den globala uppvärmningen i världen är direkt kopplad till de ökade utsläppen av CO2 i atmosfären från mänsklig verksamhet. För att minska CO2 utsläppen från förbränningsmotorn, vid användning av fossila bränslen, måste dess bränsleförbrukning minskas. Förbränning genom kompressionsantändning av en homogen blandning (Homogeneous Charge Compression Ignition - HCCI) ger en ytterligare förbättringspotential till förbränningsmotorn. HCCI förbränning sänker bränsleförbrukningen hos bensinmotorer till nivåer jämförbara med dieselmotorer, medan HCCI förbränningen i diesel motorer eliminerar partikel och NOx utsläppen. Innan HCCI förbränningen kan börja användas storskaligt måste vissa problem lösas som t.ex. hur självantändningen vid HCCI förbränning skall kontrolleras och i hur stort arbetsområde, dvs. i varvtal och last, kan den användas.



I denna avhandling undersöks potentialen att reglera HCCI förbränningen i en motor med variabelt kompressionsförhållande och dess prestanda med avseende på arbetsområde och verkningsgrad. HCCI förbränningen åstadkoms med hjälp av högt kompressionsförhållande, uppvärmning av insugsluften, och med luft som utspädning. Förbränningsfasningen regleras med det variabla kompressionsförhållandet och med snabb reglering av temperaturen på insugsluften. Förbränningsfasningen, beräknad från cylinderindividuella tryckmätningar, används som återkoppling i regleringen. En del av insugsluften värms upp med avgaser i en värmeväxlare och blandas med kall, ouppvärmd luft innan motorn. Temperaturen på insugsluften regleras med strypspjäll som kontrollerad mängden varm respektive kall luft. Både konventionella PID regulatorer och tillståndsåterkopplade regulatorer har provats för att förbättra regleringen av förbränningsfasningen. Transientreglering i en Europeisk körcykel, EC2000, har utförts för att undersöka både regler- och motorprestanda.



Kompressionsförhållanden mellan 9:1 och 30:1 har provats och förhållandet mellan insugslufttemperatur och kompressionsförhållande har optimerats. Arbetsområdet med HCCI förbränning och faktorerna som påverkar arbetsområdet har också undersökts. Laster mellan -1 till 6bar BMEP, samt motorvarvtal mellan 650 och 5000rpm har åstadkommits. Prestanda vid låga laster kan förbättras genom strypning, tidig förbränningsfasning, oxiderande katalysatorer med låg antändningstemperatur, och restgaser. Maximal last kan ökas genom turboladdning, katalysator före turbin, cylinderbalansering, låga oktantal, och tändassisterad HCCI förbränning. För att täcka hela emissionskörcykeln har förbränningsmodväxlingar till vanlig otto-förbränning utförts, samt blandad HCCI och flampropagering undersökts. Prestanda har jämförts mellan tre HCCI motorer med olika slagvolym och skillnaderna i bromsad verkningsgrad undersökts. (Less)
Abstract
The prime mover in the world today is the Internal Combustion (IC) engine. The development and improvement of the internal combustion engines since Nicolaus August Otto and Rudolf Diesel has continued until today and will continue long into the future. No major competitor to the IC engine has yet emerged. There is a long list of potential competitors but they still have to prove their superiority in practice before they can make it to the market. New technologies, as hybrids, improving the use of IC engines in vehicles have during the last few years become common. These technologies suppress the drawbacks of the IC engines, i.e. where it has poor efficiency, and take advantage of its benefits. The environmental impact of the IC engine, due... (More)
The prime mover in the world today is the Internal Combustion (IC) engine. The development and improvement of the internal combustion engines since Nicolaus August Otto and Rudolf Diesel has continued until today and will continue long into the future. No major competitor to the IC engine has yet emerged. There is a long list of potential competitors but they still have to prove their superiority in practice before they can make it to the market. New technologies, as hybrids, improving the use of IC engines in vehicles have during the last few years become common. These technologies suppress the drawbacks of the IC engines, i.e. where it has poor efficiency, and take advantage of its benefits. The environmental impact of the IC engine, due to its large numbers, is unacceptable. The advanced engine control and exhaust after treatment of the conventional IC engines have decreased the regulated emissions, NOx, CO, HC, and particulates, to very low levels and the coming legislations will decrease them further. However, the main greenhouse gas, CO2, from IC engines is and will continue to be a problem in the future. The global heating of the world is directly connected to the increasing in CO2 emissions emitted to the atmosphere by human activities. To decrease CO2 emission from IC engines running on fossil fuel we need more fuel efficient IC engines. Homogeneous Charge Compression Ignition (HCCI) combustion is a further improvement potential for the IC engine. HCCI combustion decreases the fuel consumption of gasoline engines to the level of diesel engines whereas HCCI combustion in a diesel engine eliminates almost all particulates and NOx emissions. Before HCCI combustion technology will come widely in use some issues have to be resolved, e.g. how shall the auto-ignition governed HCCI combustion be controlled and in what operating range, in terms of speed and load, can it be used. In this thesis the potential of a Variable Compression Ratio engine to control the HCCI combustion and its performance, in terms of operating range and efficiency, are investigated. The HCCI combustion is achieved using high compression ratio, inlet air heating, and air as dilution. The combustion phasing is controlled by Variable Compression Ratio and Fast Thermal Management of the inlet air temperature. Combustion phasing, calculated from cylinder individual pressure measurement, is used as feedback. The inlet air temperature is heated with an exhaust-to-inlet heat exchanger and controlled by mixing a hot and cold air flow using throttle valves. Both conventional PID controllers and state feedback controllers are tested to improve the performance of combustion phasing control. Transient control in the European drive cycle, EC2000, is done to investigate controller- and engine performance. Compression ratios between 9:1 and 30:1 are tested and the trade-off between inlet air temperature and compression ratio is optimized. The operating range with HCCI combustion and the affecting parameters are also investigated. Engine loads between -1 and 6.1 bar BMEP and engine speeds between 650 and 5000rpm are run. Minimum load performance can be improved using throttling, early combustion phasing, low temperature oxidizing catalysts, low temperature reactions, and exhaust residuals. Maximum load can be increased by turbocharging, pre-turbine catalyst, cylinder balancing, low octane number fuels, and spark assisted HCCI combustion. To cover the entire drive cycle combustion mode transfer and mixed HCCI and SI combustion are investigated. The performance of three multi-cylinder HCCI engines with different displacements and combustion chamber area-to-volume ratios are compared and the differences in brake efficiency explained. (Less)
Please use this url to cite or link to this publication:
author
supervisor
opponent
  • Professor Zhao, Hua, Brunel University, Great Britain
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Motorer, framdrivningssystem, Variable Compression Ratio, Homogeneous Charge Compression Ignition VCR, termodynamik, Motors and propulsion systems, Termisk teknik, applied thermodynamics, Thermal engineering, Cylinder-to-cylinder, Turbocharging, Multi cylinder, Cylinder balancing, Thermal Management, HCCI
publisher
Lund University Faculty of Engineering Department of Energy Sciences Division of Combustion Engines P.O. Box 118, SE-221 00 LUND Sweden
defense location
Ole Römers väg 1 Room M:B of the M-building Lund Institute of Technology
defense date
2005-12-16 10:15
external identifiers
  • other:ISRN:LUTMDN/TMHP--05/1034--SE
ISSN
0282-1990
ISBN
91-628-6681-8
language
English
LU publication?
yes
id
fd1d4917-61ae-4ab6-9b06-e9ec5aadc61b (old id 545898)
date added to LUP
2007-09-10 09:24:16
date last changed
2016-09-19 08:44:56
@phdthesis{fd1d4917-61ae-4ab6-9b06-e9ec5aadc61b,
  abstract     = {The prime mover in the world today is the Internal Combustion (IC) engine. The development and improvement of the internal combustion engines since Nicolaus August Otto and Rudolf Diesel has continued until today and will continue long into the future. No major competitor to the IC engine has yet emerged. There is a long list of potential competitors but they still have to prove their superiority in practice before they can make it to the market. New technologies, as hybrids, improving the use of IC engines in vehicles have during the last few years become common. These technologies suppress the drawbacks of the IC engines, i.e. where it has poor efficiency, and take advantage of its benefits. The environmental impact of the IC engine, due to its large numbers, is unacceptable. The advanced engine control and exhaust after treatment of the conventional IC engines have decreased the regulated emissions, NOx, CO, HC, and particulates, to very low levels and the coming legislations will decrease them further. However, the main greenhouse gas, CO2, from IC engines is and will continue to be a problem in the future. The global heating of the world is directly connected to the increasing in CO2 emissions emitted to the atmosphere by human activities. To decrease CO2 emission from IC engines running on fossil fuel we need more fuel efficient IC engines. Homogeneous Charge Compression Ignition (HCCI) combustion is a further improvement potential for the IC engine. HCCI combustion decreases the fuel consumption of gasoline engines to the level of diesel engines whereas HCCI combustion in a diesel engine eliminates almost all particulates and NOx emissions. Before HCCI combustion technology will come widely in use some issues have to be resolved, e.g. how shall the auto-ignition governed HCCI combustion be controlled and in what operating range, in terms of speed and load, can it be used. In this thesis the potential of a Variable Compression Ratio engine to control the HCCI combustion and its performance, in terms of operating range and efficiency, are investigated. The HCCI combustion is achieved using high compression ratio, inlet air heating, and air as dilution. The combustion phasing is controlled by Variable Compression Ratio and Fast Thermal Management of the inlet air temperature. Combustion phasing, calculated from cylinder individual pressure measurement, is used as feedback. The inlet air temperature is heated with an exhaust-to-inlet heat exchanger and controlled by mixing a hot and cold air flow using throttle valves. Both conventional PID controllers and state feedback controllers are tested to improve the performance of combustion phasing control. Transient control in the European drive cycle, EC2000, is done to investigate controller- and engine performance. Compression ratios between 9:1 and 30:1 are tested and the trade-off between inlet air temperature and compression ratio is optimized. The operating range with HCCI combustion and the affecting parameters are also investigated. Engine loads between -1 and 6.1 bar BMEP and engine speeds between 650 and 5000rpm are run. Minimum load performance can be improved using throttling, early combustion phasing, low temperature oxidizing catalysts, low temperature reactions, and exhaust residuals. Maximum load can be increased by turbocharging, pre-turbine catalyst, cylinder balancing, low octane number fuels, and spark assisted HCCI combustion. To cover the entire drive cycle combustion mode transfer and mixed HCCI and SI combustion are investigated. The performance of three multi-cylinder HCCI engines with different displacements and combustion chamber area-to-volume ratios are compared and the differences in brake efficiency explained.},
  author       = {Hyvönen, Jari},
  isbn         = {91-628-6681-8},
  issn         = {0282-1990},
  keyword      = {Motorer,framdrivningssystem,Variable Compression Ratio,Homogeneous Charge Compression Ignition VCR,termodynamik,Motors and propulsion systems,Termisk teknik,applied thermodynamics,Thermal engineering,Cylinder-to-cylinder,Turbocharging,Multi cylinder,Cylinder balancing,Thermal Management,HCCI},
  language     = {eng},
  publisher    = {Lund University Faculty of Engineering Department of Energy Sciences Division of Combustion Engines P.O. Box 118, SE-221 00 LUND Sweden},
  school       = {Lund University},
  title        = {The Performance of a Multi Cylinder HCCI Engine using Variable Compression Ratio and Fast Thermal Management},
  year         = {2005},
}