Tài liệu học tập cơ bản khái quát về động cơ và các bộ phận trên ô tô phiên bản tiếng anh. Tài liệu này nhằm giúp chúng ta tiếp cận được cấu tạo chức năng của các bộ phận của xe. Với tài liệu này giúp các bạn sinh viên ngành cơ khí ô tô tiếp cận được những kiến thức cơ bản về ô tô và đồng thời nâng cao kiến thức tiếng anh. Bộ tài liệu này được soạn thảo bởi trường đào tạo và huấn luyện nghề ở Canada.
Chapter 35 Fuels and Other Energy Sources Petroleum Products • • • • • • • Lubricating oil Grease Asphalt Kerosene Diesel fuel Gasoline Natural gas Refining • Separates the hydrocarbons into useful substances by fractional distillation • Very few of the fractions are usable without treating and cleaning • Some fractions are altered to be used for a specific application Gasoline • A mixture of about 300 ingredients • Chemically represented as C8H15 • Oil refiners must meet standards set by the American Society for Testing and Standards, the EPA, and some state requirements • Major factors affecting fuel performance: – Antiknock quality, volatility, sulfur content, and deposit control Antiknock Quality • Represented by the octane number • Two methods used to determine octane number: – Motor octane number (MON) – Research octane number (RON) • A test sample of fuel is used in a laboratory engine Factors That Affect Engine Knock • Lean fuel mixture • Over advanced ignition timing • Compression ratio • Valve timing • Turbocharging or supercharging • Coolant temperature • Excessive carbon deposits • Air inlet temperature • Combustion chamber shape • Octane number Volatility • Readily evaporates so gas vapor adequately mixes with air for combustion • Gasoline volatility affects: – Cold starting and warm-up – High altitude operation – Crankcase oil dilution Volatility (cont’d) • Gasoline is blended for summer use and winter use • Fuels in high altitude areas must have higher volatility • Volatility most commonly measured by the Reid vapor pressure test Basic Gasoline Additives • • • • • • • • • Anti-icing or deicer Metal deactivators and rust inhibitors Gum or oxidation inhibitors Detergents Oxygenates Ethanol Methanol MTBE Aromatic hydrocarbons Gasoline Quality Testing • Reid Vapor Pressure – Measures the volatility of the fuel – Affects how an engine runs in cold weather • Alcohol Test – Excessive alcohol can cause corrosion and damage to rubber components – May cause driveability complaints Hydraulic Hybrids • Energy is stored in tanks of hydraulic fluid under pressure • Stores energy when braking and uses it when accelerating from a stop • Also used to slow the vehicle for stopping • May allow for 60 – 70% fuel savings in large vehicles Hybrid Service • Hybrids use very high voltages • HV cables covered in orange • Refer to service procedures for depowering HV system before all service work • A/C, engine, transmission, and bodywork require work around the HV system Maintenance and Service • Non-hybrid components maintained and serviced in same way as conventional vehicles • Awareness and understanding of the stop/start feature necessary for safety reasons • If not shut down correctly, the engine can start on its own Toyota Prius Ready Light Diagnostics • HEVs have unique systems that require special tools and procedures • Some hybrids allow the disabling of the hybrid electric drive system for diagnosis • A manufacturers scan tool may be necessary to provide complete diagnostic access Test Equipment • To test high-voltage, a Category (CAT III) meter is needed • High-voltage gloves • Insulation tester Fuel Cell Electric Vehicles • FCEVs have electric motors • A fuel cell generates electricity for the motor and/or battery • May use hydrogen or other fuel as the energy source • Pure water and heat are the only emissions ... • Available due to mandates Previous standard allowed up to 500 PPM New standard is 15 PPM Allows diesels to emit less NOx, soot, and other sulfur compounds Bio Diesel • Fuels derived from renewable... stop/start and regenerative braking: – Saturn Vue and Aura Advantages • Consume less fuel • Far fewer emissions due to smaller and more efficient engine and stop/start technology • Many accessories and. .. transmission, and bodywork require work around the HV system Maintenance and Service • Non-hybrid components maintained and serviced in same way as conventional vehicles • Awareness and understanding