Introduction Engine Systems Chris Onder, Raffael Hedinger, Norbert Zsiga, Michael Zihlmann 1
Introduction Engine Systems 1. Concept of a combustion engine 2. Different types of engines 3. Topics of the lecture «Engine Systems» 4. Tour through engine hallway ML E 2
Open the hood 3
Simplified model of a gasoline engine IC Intake manifold Exhaust manifold Engine block 6
Simplified model of a gasoline engine Fuel pump ET Injection FP IC Ignition coil Valves Throttle Exhaust manifold Intake manifold Engine block 7
Simplified model of an engine MA Fuel pump ET TA PM Injection FP IC Ignition coil Valves l 1 l 2 Throttle AK TE Exhaust manifold Intake manifold Engine block AK CP IC MA SE FP knock sensor camshaft sensor ignition command air mass-flow sensor engine speed sensor fuel pressure control PM ET TA TE CC l 1,2 manifold pressure sensor VE electronic throttle SA intake air temperature sensor TWC cooling water temperature sensor ECU active carbon canister CCV air/fuel ratio sensors DP EGR valve secondary air valv 3-way catalyst controller CC control valves driver pedal 8
Simplified model of a gasoline engine MA ET TA PM FP IC CP l 1 l 2 AK TE AK CP IC MA SE FP knock sensor camshaft sensor ignition command air mass-flow sensor engine speed sensor fuel pressure control PM ET TA TE CC l 1,2 manifold pressure sensor electronic throttle intake air temperature sensor cooling water temperature sensor active carbon canister air/fuel ratio sensors VE SA TWC ECU CCV DP EGR valve secondary air valve 3-way catalyst controller CC control valves driver pedal 9
Simplified model of gasoline engine MA ET TA PM VE FP IC CP l 1 l 2 DP CCV AK TE SA CCV CC Tank SE AK CP IC MA SE FP knock sensor camshaft sensor ignition command air mass-flow sensor engine speed sensor fuel pressure control PM ET TA TE CC l 1,2 manifold pressure sensor electronic throttle intake air temperature sensor cooling water temperature sensor active carbon canister air/fuel ratio sensors VE SA TWC ECU CCV DP EGR valve secondary air valve 3-way catalyst controller CC control valves driver pedal 10
1 1 Simplified model of gasoline engine Questions: Which control actuators are minimally needed for a gasoline engine Why can the engineblock be intrepreted as a volumetric pump? Anwers: Throttle, Injector,ignition coil, valves,. It pumps air form the low pressure intake manifold to the higher pressure exhaust manifold (exception: supercharged)
Mechanical System 12
4 Stroke Engine In this class only four stroke engines The four strokes: 1. Intake Stroke 2. Compression Stroke 3. Power Stroke 4. Exhaust Stroke => Engine cycle consists of two revolutions 13
2 Stroke Engine Power Stroke and Compression Stroke are combined Intake Stroke and Exhaust Stroke are combined, i.e. inflowing air washes out exhaust gas. => Engine cycle consists of one revolution 14
Gasoline & Diesel Engines Gasoline Diesel Spark Ignition SI Engine Compression Ignition CI Engine 15
Gasoline & Diesel Engines Gasoline Diesel Low power Low power «Quantitative Control» «Qualitative Control» High power High power 16
Gasoline & Diesel Engines Questions: Is the combustion in a diesel engine stochiometric? (lambda=1) Is a throttle needed for a Diesel engine? What is the effect of pressing the gas pedal in a diesel and gasoline engine resprectively? Anwers: No! There is always excess air No! The power is controlled by the amount of injected fuel Diesel: Inject more fuel Gasoline: Opening of throttle, more air into cylinder, controller injects then more fuel 17
Self Induction & Forced Induction Engines Self induction/ naturally aspirated Forced induction/ super charged Air is sucked in by the down stroke of the cylindar which results in a pressure drop in the intake manifold Air is forced into the intake manifold by the charger 18
Self Induction & Forced Induction Engines Questions: Why does forced induction lead to higher specific power (W/kg)? Anwers: For the same displacement volume ( Hubraum) = same weight, more fuel can be burned, more power is generated Where is the power taken from for the compressor in forced induction? Turbocharger, energy from exhaust gas Mechanical, energy from engine shaft 20
Information on the lecture Control of engine is in the focus (not thermodynamics and mechanics) Focus is on modelling only of the engine system Suitable lecture «Vehicle propulsion systems», focus on whole vehicle Good textbook/script is available Idle speed controller is developped and tested on real engine Oral exam in the end 21
ML E floor - «Tour de moteur» 22
Thank you for your attention. Let s go!