ALTERNATIVE FUELS AND VEHICLES CONVENTIONAL FUELS Carlos Sousa

ALTERNATIVE FUELS AND VEHICLES CONVENTIONAL FUELS Carlos Sousa AGENEAL, Local Energy Management Agency of Almada www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES DIESEL AND PETROL ENGINES • 4 Stroke Cycle • Main components • Auxiliary Systems www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES DIESEL 4 Stroke Cycle INTAKE Air enters the combustion chamber www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES DIESEL 4 Stroke Cycle COMPRESSION With all the valves closed, the piston goes up, compressing the air inside the cylinder Increase in air temperature and pressure www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES DIESEL 4 Stroke Cycle INJECTION The fuel is injected into the cylinder at high pressure, after the compression of the air www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES DIESEL 4 Stroke Cycle EXPANSION The fuel inflames when it contacts with the hot air The mechanical delivered the engine is now generated www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES DIESEL 4 Stroke Cycle EXHAUST After the combustion, the hot gases leave the cylinder through the exhaust valve(s) www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES DIESEL 4 Stroke Cycle COMBUSTÃO INTAKE COMPRESSION INJECTION EXPANSION EXHAUST www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES • Compression Ratio = www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES MAIN COMPONENTS OF THE ENGINE www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES MAIN COMPONENTS OF THE ENGINE • Piston – Transmits the movement to the rod • Connecting Rod – Transmits the movement to the cranshaft • Crankshaft – Transforms the alternative movement in circular movement www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES MAIN AUXILIARY SYSTEMS • Distribution (opening / closing of the valves) • Cooling system (prevents components from overheating) • Lubrication (reduces sheer, washes components, etc. ) • Fuel (fuel intake) www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES DISTRIBUTION Double Over. Head Cam, DOHC Lateral Cam www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES DISTRIBUTION www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES COOLING SYSTEMS Objectives 1. Cool engine components: è keep the engine at a suitable operating temperature (i. e. prevent the melting of components) è keep the physical and chemical proprieties of the lubricating oil (can deteriorate with exessive temperature) 2. Provide heat to acclimatize the interior of the vehicle 3. Improve cold start www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES COOLING SYSTEMS • Water pump • Thermostat • Radiator • Fan • Heating system www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES LUBRICATING SYSTEM The function of the engine oil is much more than lubricating. The oil must also have: • High detergent and dispersant power • High anti-oxidation power • Good cooling capacity (contributes to engine cooling) • Good capacity to neutralize acids • Maintain its with temperature change (cold and hot) www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES LUBRICATING SYSTEM www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES FUEL SYSTEM Objective: • Introduce fuel in the engine, that will mix with the hot air inside the cylinder, evaporate, auto-inflame and burn www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES FUEL SYSTEM 1. Indirect injection 2. DIRECT INJECTION • Direct injection in the cylinders • Higher injection pressures • More expensive and demanding technology • Multiple jet injectors www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES DIRECT INJECTION vs. INDIRECT INJECTION Losses Performance Speed Fuel Injection Direct Indirect Lower thermal losses High thermal losses between chambers Higher Lower Slow engine speed Higher engine speed Demands higher quality fuels Works with lower quality fuels (viscosity, cetane number) Multi-jet (higher injection pressure) Single-jet (lower injection pressures) www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES DIRECT INJECTION vs. INDIRECT INJECTION Advantages Inconvenients Lower fuel consumption Price Power Noise Cold start Vibration www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES DIRECT INJECTION www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES DIRECT INJECTION Squish and Swirl www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES TYPES OF INJECTION SYSTEMS • Radial and in-line pump • Injector-pump • Common Rail www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES TYPES OF INJECTION SYSTEMS In-line pump 600. . . 700 bar 1 000 bar at the tip of the injector www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES TYPES OF INJECTION SYSTEMS Radial pump 1 000 to 1 500 bar at the tip of the injector www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES INJECTION SYSTEMS Injector Pump 2000 bar Advantages • No high-pressure fuel lines • Higher injection pressures • Lower fuel consumption • Better torque and power at low engine speeds www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES INJECTION SYSTEMS Pressão máx. 1350 – 1500 bar Common-Rail 1 800 2 000 bar Advantages • Better injection control • Reduction of noise and vibration • Good fuel consumption • Good torque and power • Reduction of pollutant emissions www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES INTAKE IN PETROL ENGINES A petrol engine can admit: • A mixture of air and fuel • Air, with the fuel being injected directly into the cylinder – Direct Injection Engines Source: Total www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES TURBOCHARGING Objective: Increase the power/weight ratio A compressor increases the density of the air before being admitted to the cylinders Disadvantages (relative to atmospheric engines - “non-turbo”): • Higher complexity and cost • Higher physical and thermal strains on the engine Advantages: • More torque and power • Better fuel consumption www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES TURBOCHARGING www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES TURBOCHARGING www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES TURBOCHARGING Variable geometry • More torque over all engine speed range • Better fuel consumption • More power www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES TURBOCHARGING INTERCOOLER Objective: Increase the power/weight ratio Cools the air after the compression, before admitting it to the cylinders: • Higher mass of air inside the cylinders • More fuel • More torque • More power www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES POLLUTANTS FORMATION AND CONTROL Combustion in Diesel engines is characterised by a high concentration of fuel droplets (poor atomization/vaporization of the fuel). Main pollutants: • Particulate Matter (PM) • Unburned Hydrocarbons, HC • Carbon Monoxide, CO • Nitrogen Oxides, NOx www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES POLLUTANTS FORMATION AND CONTROL Emissions control: • Exhaust Gas Recirculation, EGR • Particulate Filters • Catalytic Converters www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES POLLUTANTS FORMATION AND CONTROL Emissions control Diesel: • Exhaust Gas Recirculation, EGR (prevents the formation of NOx) • Particulate Filters, active and passive (PM) • Oxidation Catalytic Converters (HC and CO) • Selective Catalytic Reduction, SCR (NOx into N 2 and H 2 O) Petrol: • 3 -way Catalytic Converters • Oxidation Catalysts (CO and HC into CO 2 and H 2 O) • Reduction Catalysts (NO into N 2 and O 2) www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES Fuel Quality, Diesel: • Diesel is cetane derived (C 10 H 22) • Cetane Number: Indicates the higher or lower capacity of the fuel to autoignite ( lower delay to auto ignition) • 15: Low capacity to auto-ignite: isocetane • 100: High capacity to auto-ignite: cetane • Minimum cetane number demanded: 51 • Sulphur content: Less than 50 ppm Low sulphur fuel • Eliminate emissions of sulphur dioxide (SO 2) • Reduce PM emissions • Less than 10 pmm: Sulphur free fuel (From 2009) www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES POLLUTANTS FORMATION AND CONTROL HC CO NOx PM Diesel Petrol www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES EUROPEAN EMISSIONS STANDARDS Diesel Passenger vehicles 2. 5 t (values in g/km) Standard Year CO HC HC + NOx PM Euro 1 1992 2. 72 - 0. 97 - 0. 14 Euro 2 - IDI 1996 1. 00 - 0. 70 - 0. 08 Euro 2 - DI 1999 1. 00 - 0. 90 - 0. 10 Euro 3 2001 0. 64 - 0. 56 0. 50 0. 05 Euro 4 2005 0. 50 - 0. 30 0. 25 0. 025 www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES ENERGY EFFICIENCY TORQUE Energy generated in one revolution of the engine, resulting from the combustion of the fuel [kg. m or N. m]. 1 kg. m=9. 8 N. m The higher the torque, the more efficient is the engine for a given engine speed. POWER Energy generated per unit of time [W or CV]. 1 k. W = 1, 36 CV 1 CV = 0, 736 k. W www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES ENERGY EFFICIENCY Torque curve • Shows the torque distribution along the entire engine speed range, at full engine charge (full throttle). • Should be as flat as possible, which means good engine response at all engine speeds. • RPM x N. m (or kg. m) www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES ENERGY EFFICIENCY Power curve • Shows the power distribution along the entire engine speed range, at full engine charge (full throttle). • RPM x k. W (or CV) www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES ENERGY EFFICIENCY • CO 2 emissions per litre: Petrol a little lower Diesel • CO 2 emissions per km: Diesel uses less fuel. . . …emits less CO 2 • Energy efficiency is a function of the compression ratio • Diesel engines use variable fuel to air ratios • Petrol engines use a constant air to fuel ratio (stoichiometric: 14. 7 to 1), no matter what the speed and load are • Diesel engines have an unthrottled intake and the air to fuel ratio at idle speed can go as low as 100 to 1, thus giving a much greater partial load fuel efficiency than petrol engines www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES Theoretical engine efficiency ENERGY EFFICIENCY Petrol engines Diesel engines Compression ratio www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES ENERGY EFFICIENCY Useful work Losses Speed variations Combustion losses Stoichiometric losses Friction losses Ideal process Losses 87% Petrol engine, urban driving www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES DIESEL vs. PETROL Diesel Petrol Admission Air and fuel Combustion Auto ignition, due to the high pressure and temperature inside the cylinder Spark ignition Fuel Must vaporize easily and auto-ignite (high cetane number) Must be resistant to autoignition (high octane number) Compression ratio Highest possible (15 to 24) Limited by fuel characteristics (9 to 12) Efficiency ~35% Less than 30% Turbo charging Whenever possible. Increases efficiency and improves combustion Not common, but is becoming a popular solution www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES DIESEL vs. PETROL Diesel Petrol Fuel consumption Lower Higher Fuel price Usually lower, but depends on the taxes applied in each country Higher Weight Heavier Lighter and more compact Start Almost immediate Immediate Vibration and noise High Low Engine speed Limited by the characteristics of the cycle and fuel High www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES CAR INDUSTRY – ONE CURIOSITY In 1976, Volkswagen came up with the designation “GTI”, but did not register it. Almost all auto makers used it!! But, in 1991, Volkswagen came up with the designation “TDI” and registered it. The result was… www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES CAR INDUSTRY – ONE CURIOSITY TDI – VAG Group Ti. D - Saab JTD - Alfa, Fiat, Lancia D- 4 D - Toyota d - BMW D 5 - Volvo CRD - Chrysler, Jeep HDI - Peugeot, Citroën TDdi - Ford Di-D – Mitsubishi TDCi - Ford d. Ti - Renault CDTi - Honda d. Ci - Renault CRDi - Hyundai CDT – Rover Dv. Tdi – Mazda DTI – Opel Di. TD – Mazda CDI – Mercedes DDTi – Nissan www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES Summary Advantages Diesel engines: • Better energy efficiency: Use less fuel/energy (work with higher compression ratios) Advantages Petrol engines: • Better cold start • Less noise and vibrations • More elasticity (higher engine speeds) • Lighter • More power for the same engine size www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES Summary Investments in Diesel engines/technology intend to: • improve atomization of the fuel (higher injection pressures) • improve flow inside the cylinder • optimize injection to reduce noise and vibration • maximize power and torque without sacrificing fuel consumption (optimize turbo charging) • optimize fuel injection to reduce fuel consumption (e. g. : injection technologies) www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES Summary Oil companies are working to: • Increase cetane number • Lower sulphur content www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES Thanks to Prof. Tiago Farias Technical University of Lisbon www. transportlearning. net

ALTERNATIVE FUELS AND VEHICLES Thank you for your attention! www. transportlearning. net