i.C engines Prepared By: Dr.S.MAGBUL HUSSAIN PROFESSOR AND HOD Department of Mechanical Engineering 1

Birth of Internal Combustion Engine Huygens Gunpowder Engine (1673) Invented gun powder based engine for pumping water. Nicolaus August Otto ( 1876 ) Rudolf Diesel (1892) Invented four-stroke compression-ignition engine Patent No. 608845 Invented four-stroke spark-ignition engine Patent No. 365701 η = 14% @ 160 RPM

Engine – An Energy converter Chemical Energy Heat Energy Combustion Mechanical Energy Piston Expansion

Combustion Vs Explosion Oxidation Reaction Fuel – Substance that give out useful energy through chemical reaction. Air – source of oxygen Combustion confined in a fixed boundary – EXPLOSION Controlled Combustion is achieved through piston expansion smoke Fuel oxygen Co2 H2o Heat Energy + + unburned Blue flame – premixed – High temp Yellow flame - Rich

What is an Internal Combustion Engine Air and Fuel in correct proportion (Air –Fuel Ratio). For Hydrocarbon fuel 14.7 kg of air per kg of fuel Ignition source Auto Ignition Temperature for Petrol – 260 °C Spark Ignited Diesel – 210 °C Compression Ignited Ignition Timing Combustion should occur at appropriate interval during the cycle

Fuel Types Less volatile Highly volatile Less auto ignition temp Gasoline Diesel Less volatile Less auto ignition temp Highly volatile High auto ignition temp

Identify the stroke ?? Spark plug

Internal Combustion Engine in reality Four Stroke EVENTS 1. Intake or suction - 0° to 180° 2. Compression - 180° to 360° Ignition (Petrol) or Fuel Injection (Diesel) 3. Combustion or Expansion - 360° to 540° 4. Exhaust - 540° to 720° PARTS Intake Valve Cam Shaft Head Cover Exhaust Valve Intake Port Spark Plug Engine Head Exhaust Port Cooling Water Jacket Piston Connecting Rod Cylinder Block Crank Pin Oil Pan Cover Crank Shaft Oil sump

Valve Timing Diagram of 4S Engine COMPRESSION EXPANSION SUCTION EXHAUST EVC 15˚a TDC EXHAUST VALVE EVENTS 1. Intake or suction - 46° b TDC to 72° a BDC 2. Compression - 72° a BDC to 0° TDC Ignition (Petrol) or Fuel Injection (Diesel) - 20° b TDC 3. Combustion or Expansion - 0° TDC to 39° b BDC 4. Exhaust - 39° b BDC to 15° a TDC INTAKE VALVE 735° -46 ° 252° 360° 501° IVO 46˚b TDC IVC 72˚a BDC EVO 39˚b BDC 0° TDC 180° BDC 360° TDC 540° BDC 720° TDC

Two Stroke EVEEVENTS EVENTS Combustion or Expansion - 0° to 120° Scavenging - 120° to 180° Filling- 180° to 210° Compression- 210° to 180° Ignition (Petrol) or Fuel Injection (Diesel)

- Displacement of exhaust gas by fresh charge. Scavenging - Displacement of exhaust gas by fresh charge. Cross Flow Scavenging Loop scavenging Uniflow scavenging

Identify the pistons used in various engines ?? (b) (c) 2 stroke petrol Engine 4 stroke petrol Engine 4 stroke Diesel Engine

Modes of Ignition Spark Ignited Compression Ignited Fuels with high autoignition temperature External ignition source – Spark plug. Start of combustion is determined by spark timing. Progressive combustion. Demerit – possibility of knock. Compression Ignited Autoignition is achieved by compression of air. Start of combustion is determined by fuel injection timing. Air-fuel Mixing and combustion occurs simultaneously – Diffusion combustion. Demerit – Smoke emission.

Maruti –Suzuki SWIFT Engine Specification ENGINE CAPACITY NO OF CYLINDERS NO OF VALVES BORE x STROKE COMPRESSION RATIO MAXIMUM POWER MAXIMUM TORQUE FUEL DISTRIBUTION AIR CHARGING SYSTEM EMISSION K –Series Petrol with VVT 1197cc 4 16 73mm x 71.5mm 11.0 : 1 62 kW @ 6000 rpm 115 Nm @ 4000 rpm Multi- point injection Naturally Aspirated BS 4 DDis diesel engine 1248cc 4 16 69.6 mm x 82 mm 17.6 : 1 55.2 kW @ 4000 rpm 190 Nm @ 2000 rpm CRDI Fixed geometry turbo charger BS 4

SI Engine Fuel Supply Strategies

Electronic Fuel Injection SYSTEM

Port Fuel Injection (PFI) Better cold starting . Low Hydrocarbon Emissions. Improved Drivability.

MPFI

Electronic sensors and actuators of Port Fuel Injection (PFI) engine

GDI

GDI Operation Modes

Gasoline Direct Injection (GDI) Multiple injection per cycle. Reduce Throttling losses Better efficiency. Stratified and Homogeneous combustion. TYPES :

CRDI

Common Rail Direct Injection (CRDI) Multiple injection per cycle. High rated engine speed. Reduced engine noise. Better efficiency. Higher injection pressure of upto 2000 bar.

Emission Carbon Dioxide - CO2 Carbon Monoxide – CO Hydro-Carbon – HC [SI] Oxides of Nitrogen – NOx [CI] Particulate Matter – PM [CI] Emissions in gram per kWh

Smoke colour and its reason:

Emission Control Three way and Two way catalytic converter Oxidise CO and HC – by Platinum or Palladium. Reduce NOx – by Rhodium. Used in SI engine. Exhaust Gas Recirculation (EGR) Recirculation of exhaust gas back to cylinder. Reduces peak temperature in cylinder. Thus Reduce the NOx . Types – Hot EGR and Cold EGR.

Turbocharger Recover part of energy lost in exhaust. Improve volumetric efficiency. Increases power to weight ratio.

Types of Turbocharger Waste gate turbocharger Variable nozzle turbocharger

Identify the Engine Parts: Cam shaft Rocker Arm Throttle (part of intake system) Diesel Injector

During starting and warm-up Liquid Cooling System Normal Operation During starting and warm-up Radiator Engine

During starting and warm-up Liquid Cooling System Normal Operation During starting and warm-up Radiator Engine

THANK YOU