Internal Combustion Engine (ICE) Presentation PDF

AB POWER ENGINEERING INTERNAL COMBUSTION ENGINE (ICE) Understanding Principles, Components, and Operation Introduction to Internal Combustion Engine (ICE) An Internal Combustion Engine (ICE) is a type of engine in which the combustion of fuel occurs directly inside the engine's combustion...

AB POWER ENGINEERING INTERNAL COMBUSTION ENGINE (ICE) Understanding Principles, Components, and Operation Introduction to Internal Combustion Engine (ICE) An Internal Combustion Engine (ICE) is a type of engine in which the combustion of fuel occurs directly inside the engine's combustion chamber. This process produces high-pressure gases that exert force on engine components, typically causing the movement of pistons, which, in turn, generates mechanical power. The key characteristic of ICEs is that the fuel burns inside the engine itself, unlike external combustion engines, where combustion takes place outside the engine. Introduction to Internal Combustion Engine (ICE) Introduction to Internal Combustion Engine (ICE) EXAMPLES Common types of internal combustion engines include: Car engines: Most cars use four-stroke gasoline or diesel engines, with the combustion process powering pistons that turn the car's wheels. Motorcycles: These also commonly use internal combustion engines, usually smaller and more lightweight than car engines, but based on the same principles. Diesel engines: Found in larger vehicles like trucks and farm equipment, diesel engines are known for their fuel efficiency and are widely used in heavy-duty applications. Introduction to Internal Combustion Engine (ICE) EXAMPLES Introduction to Internal Combustion Engine (ICE) PURPOSE The primary purpose of an internal combustion engine is to convert chemical energy stored in fuel (such as gasoline, diesel, or alternative fuels) into mechanical energy. This mechanical energy can then be used to: Drive the movement of a vehicle (car, truck, tractor, etc.). Power agricultural machinery such as plows, harvesters, and pumps. Operate generators that produce electricity. This energy conversion process is critical in countless applications, making ICEs a fundamental technology in transportation, industrial machinery, and agricultural systems. Introduction to Internal Combustion Engine (ICE) KEY POINTS: Fuel Combustion Inside the Engine: The distinctive feature of an ICE is the combustion that happens within the engine, producing gases that directly perform work. Energy Conversion: Chemical energy from fuel is converted into heat and then mechanical energy, which drives machinery or vehicles. Wide Applications: ICEs are widely used in various sectors, from agriculture and transport to power generation, due to their ability to provide significant amounts of power from relatively compact units.  Thermodynamic Principles In an internal combustion engine (ICE), thermodynamic principles govern the conversion of fuel into usable energy. This process begins with fuel combustion, which releases heat. This heat causes the expansion of gases inside the combustion chamber, producing mechanical work by driving pistons or turning rotors. The study of thermodynamics in engines involves understanding how energy is transferred and transformed during this process. Energy conversion: The engine converts the chemical energy stored in the fuel into heat energy through combustion, and subsequently into mechanical energy (movement of engine parts like pistons). Mechanical work: The mechanical energy produced in ICEs powers vehicles or machinery, with the thermodynamic process ensuring efficient and controlled power generation.  Thermodynamic Principles Key Concepts: Pressure, Volume, Temperature, and Energy Transfer 1. Pressure (P): ⚬ The combustion of fuel increases the pressure inside the combustion chamber, exerting force on the pistons. ⚬ High-pressure gases expand, causing the engine components to move, which is essential for generating mechanical energy. 2. Volume (V): ⚬ Volume changes as the piston moves within the cylinder during different strokes of the engine cycle. During the combustion phase, the gas expands, increasing the volume in the cylinder. 3. Temperature (T): ⚬ Temperature rises as fuel combusts, causing the gas molecules to move faster. This rise in temperature is crucial for generating the high pressure needed to power the engine. ⚬ As temperature drops during the exhaust phase, energy dissipates, and the gas leaves the chamber. 4. Energy Transfer: ⚬ The transfer of energy in an engine occurs primarily in two forms: as heat energy during combustion and as mechanical energy when gas expansion moves engine components.  Thermodynamic Principles IDEAL GAS LAW The Ideal Gas Law is an equation that relates pressure (P), volume (V), and temperature (T) of gases, important in understanding the behavior of gases in the engine: PV=nRT P (Pressure): Pressure in the cylinder increases as fuel combusts. V (Volume): The volume changes as the piston moves within the cylinder. T (Temperature): Temperature increases during combustion, driving the gas expansion. n (Amount of substance): Number of gas molecules. R (Gas constant): A constant value in the equation. The Ideal Gas Law helps explain how the gases in the engine respond to changes in pressure, volume, and temperature during combustion and expansion.  Thermodynamic Principles FIRST LAW OF THERMODYNAMICS The First Law of Thermodynamics states that energy cannot be created or destroyed, only transformed. In the context of an internal combustion engine: The energy from fuel is not lost but rather converted into heat through combustion and then into mechanical work as the engine’s moving parts respond to gas expansion. Any excess heat not converted into work is typically lost through exhaust or engine cooling systems. This principle ensures that all the energy entering the engine (through fuel) is accounted for, either as work or waste heat.  Thermodynamic Principles SECOND LAW OF THERMODYNAMICS The Second Law of Thermodynamics explains that heat flows from a high-temperature region to a low- temperature region. In ICEs: Heat energy generated by combustion moves from the high-temperature gases to the cooler engine components and is eventually transferred out via the exhaust. This law also underlines that not all heat energy can be converted into mechanical work, resulting in some energy being lost as waste heat. This is why engines cannot operate at 100% efficiency.  Thermodynamic Principles KEY TAKEAWAYS: Energy Conversion: Thermodynamic principles explain how an engine converts fuel into heat and mechanical energy. Gas Behavior: The Ideal Gas Law describes how the gases inside the engine behave during combustion and expansion. Energy Conservation: The First Law of Thermodynamics ensures that energy is neither created nor destroyed in the process. Heat Flow: The Second Law of Thermodynamics explains the natural flow of heat and the limitations on engine efficiency. Engine Components The Main Components of IC Engine are: 1.Exhaust camshaft 2.Exhaust valve bucket 3.Spark plug 4.Intake valve bucket 5.Intake camshaft 6.Exhaust valve 7.Intake valve 8.Cylinder head 9.Piston 10.Piston pin 11.Connecting rod 12.Engine block 13.Crankshaft  Engine Components Exhaust camshaft: A rotating shaft that controls the opening and closing of the exhaust valves. Exhaust valve bucket: A component that sits on top of the valve stem and transfers the motion from the camshaft to open and close the exhaust valve. Spark plug: A device that ignites the air-fuel mixture in the combustion chamber to initiate the combustion process. Intake valve bucket: Similar to the exhaust valve bucket, it transfers the motion from the camshaft to open and close the intake valve. Intake camshaft: A rotating shaft that controls the opening and closing of the intake valves. Exhaust valve: A valve that opens to allow the exhaust gases to exit the combustion chamber during the exhaust stroke. Intake valve: A valve that opens to allow the fresh air-fuel mixture to enter the combustion chamber during the intake stroke.  Engine Components Cylinder head: The topmost part of the engine that houses the combustion chambers, valves, and spark plugs. Piston: A cylindrical component that moves up and down inside the cylinder, driven by the force generated by the combustion process. Piston pin: Also known as a wrist pin, it connects the piston to the connecting rod, allowing the piston to pivot. Connecting rod: Connects the piston to the crankshaft and transfers the linear motion of the piston into rotational motion. Engine block: The main housing of the engine that contains the cylinders and provides support for various engine components. Crankshaft: Converts the reciprocating motion of the pistons into rotational motion, which drives the transmission and, ultimately, the wheels. Engine Components  Engine Cycles and Timing FOUR-STROKE CYCLE: In a four-stroke engine, the entire combustion process is completed in four distinct strokes of the piston. These four strokes represent different stages of the combustion cycle that together generate power for the engine. The four strokes are as follows: Intake Stroke: ⚬ During the intake stroke, the intake valve opens, allowing the air-fuel mixture (in gasoline engines) or air (in diesel engines) to enter the combustion chamber. ⚬ The piston moves downward, creating a vacuum that pulls the air-fuel mixture into the cylinder. ⚬ This stage is crucial for preparing the right mixture of fuel and air for efficient combustion. Compression Stroke: ⚬ The intake valve closes, and the piston moves upward, compressing the air-fuel mixture into a smaller space at the top of the cylinder. ⚬ Compression increases the temperature and pressure of the mixture, making it more combustible. ⚬ This compression is essential for achieving efficient combustion, as it ensures the fuel burns thoroughly.  Engine Cycles and Timing Power (Combustion) Stroke: ⚬ The power stroke begins when the spark plug ignites the compressed air-fuel mixture (in gasoline engines), or when fuel is injected into the high-temperature compressed air in diesel engines, causing combustion. ⚬ The combustion of fuel generates a rapid expansion of gases, which forces the piston downward. This downward movement is what generates mechanical energy. ⚬ The energy from the power stroke is transferred to the crankshaft, converting linear motion into rotational motion to drive the vehicle or machinery. Exhaust Stroke: ⚬ After the power stroke, the exhaust valve opens, and the piston moves upward again, pushing the burnt gases out of the cylinder and into the exhaust system. ⚬ This clears the cylinder, making it ready for the next cycle to begin.  Engine Cycles and Timing FOUR-STROKE CYCLE:  Engine Cycles and Timing ADVANTAGES OF FOUR-STROKE ENGINES Fuel Efficiency: ⚬ Four-stroke engines typically offer better fuel efficiency compared to two-stroke engines because they use fuel more completely and effectively, leading to lower fuel consumption per power output. Lower Emissions: ⚬ Because they burn fuel more efficiently and have a more complete combustion process, four-stroke engines tend to produce fewer emissions, making them more environmentally friendly. They also incorporate an exhaust stroke that helps clear out burnt gases, reducing the likelihood of unburnt fuel entering the exhaust system. Longer Lifespan: ⚬ Four-stroke engines generally have a longer lifespan due to lower operating temperatures and pressures during the compression stroke, which reduces wear and tear on engine components.  Engine Cycles and Timing ADVANTAGES OF FOUR-STROKE ENGINES Greater Torque and Power Output: ⚬ These engines provide higher torque and power output at lower RPMs, making them suitable for a wide range of applications, including vehicles and heavy machinery. Better Performance: ⚬ Four-stroke engines are known for smoother operation and better performance characteristics, particularly in terms of acceleration and overall power delivery. More Versatile Applications: ⚬ The design of four-stroke engines allows them to be used in various applications, including cars, trucks, generators, and many types of machinery.  Engine Cycles and Timing DISADVANTAGES OF FOUR-STROKE ENGINES Complex Design: ⚬ Four-stroke engines have more components than two-stroke engines, such as valves, camshafts, and timing mechanisms. This complexity can lead to higher manufacturing and maintenance costs. Weight and Size: ⚬ Generally, four-stroke engines are larger and heavier than two-stroke engines due to their additional components. This can make them less suitable for applications where weight is a critical factor, such as in some motorcycles or portable equipment. Higher Initial Cost: ⚬ The complexity and additional components of four-stroke engines can result in a higher initial purchase price compared to two-stroke engines. Less Power-to-Weight Ratio: ⚬ While four-stroke engines produce more power overall, their power-to-weight ratio is often lower than that of two-stroke engines, making them less suitable for certain applications where weight and compactness are important. Maintenance Requirements: ⚬ Four-stroke engines typically require more regular maintenance, such as oil changes and valve adjustments, which can increase the overall cost of ownership.  Engine Cycles and Timing TWO-STROKE CYCLE: A two-stroke engine completes the entire combustion process in just two piston strokes, rather than four. The key difference is that the intake and compression stages are combined into one stroke, and the power and exhaust stages are combined into another. First Stroke (Intake and Compression): ⚬ As the piston moves upward, a mixture of air and fuel enters the combustion chamber while simultaneously compressing it. Second Stroke (Power and Exhaust): ⚬ Combustion occurs at the top of the stroke, and the expanding gases push the piston down. As the piston moves down, the exhaust gases are expelled through the exhaust port.  Engine Cycles and Timing TWO-STROKE CYCLE:  Engine Cycles and Timing Advantages of Two-Stroke Engines: Simpler design with fewer components, making them lighter. Higher power-to-weight ratio compared to four-stroke engines. Used in applications like chainsaws, lawnmowers, and some motorcycles. Disadvantages: Less fuel-efficient due to incomplete combustion. Higher emissions compared to four-stroke engines.  Engine Cycles and Timing TIMING SYSTEMS: Engine timing systems are crucial for ensuring that the various engine components (such as valves and pistons) operate in perfect synchronization. Timing ensures that: Valves open and close at the correct times during the four-stroke or two-stroke cycle. Spark plug firing occurs at the exact moment when the air-fuel mixture is fully compressed, ensuring efficient combustion. Two key timing mechanisms include: 1. Camshaft Timing: ⚬ The camshaft controls the opening and closing of the engine's valves. The timing belt or timing chain ensures that the camshaft is perfectly synchronized with the crankshaft, so the valves open and close at the correct point during the piston’s movement. 2. Ignition Timing: ⚬ In gasoline engines, the spark plug must fire at just the right moment—usually just before the piston reaches the top of the compression stroke. Proper ignition timing ensures that the combustion occurs when the mixture is fully compressed, maximizing the efficiency of the power stroke. Engine Cycles and Timing  Engine Cycles and Timing KEY TAKEAWAYS: Four-Stroke Cycle: Consists of intake, compression, power, and exhaust strokes, providing efficient fuel combustion and energy transfer. Two-Stroke Cycle: Completes the same process in two strokes, simplifying the engine design but with higher emissions and less efficiency. Timing Systems: Ensure the precise operation of engine components, including valve operation and ignition, to maximize engine performance and efficiency.  Power Efficiencies and Measurements Power Measurement: ⚬ Horsepower (HP): A measure of the engine’s power output. ⚬ Torque: The force that causes rotation. Efficiency: ⚬ Thermal efficiency: Measures how well the engine converts fuel into useful work. ⚬ Mechanical efficiency: Compares actual output to the engine's theoretical maximum. Power Measurements Horsepower (HP): Horsepower is a standard unit of measurement used to express the power output of engines. One horsepower is defined as the ability to do work at a rate of 550 foot-pounds per second or approximately 746 watts. There are different types of horsepower, including: ⚬ Mechanical Horsepower: Commonly used in the automotive industry, equivalent to 745.7 watts. ⚬ Metric Horsepower: Defined as approximately 735.5 watts and often used in Europe. Horsepower indicates how quickly an engine can perform work; higher horsepower ratings suggest a more powerful engine, making it capable of producing greater acceleration and speed. Power Measurements Torque: Torque refers to the rotational force produced by the engine and is typically measured in foot- pounds (ft-lbs) or Newton-meters (Nm). It is the force that causes the engine’s crankshaft to rotate, enabling the vehicle to move. Torque is especially important for tasks requiring strong pulling power, such as towing or carrying heavy loads. The torque curve of an engine indicates how torque varies with engine speed (RPM). A flat torque curve is generally desirable, as it indicates that the engine can produce ample torque across a range of speeds. Power Efficiencies Thermal Efficiency: Thermal efficiency is a measure of how effectively an engine converts the energy stored in fuel into useful mechanical work. It is expressed as a percentage. The formula for thermal efficiency (ŋthermal) is: ŋthermal = (Output Work/Input Energy)×100% For example, if an engine converts 30% of the fuel's energy into work, its thermal efficiency is 30%. The remaining energy is typically lost as heat to the exhaust, coolant, and engine surfaces. Higher thermal efficiency indicates a more economical engine, as it uses less fuel for the same output. Power Efficiencies Mechanical Efficiency: Mechanical efficiency measures how well the engine converts the power generated by combustion into usable power at the crankshaft. It accounts for internal losses due to friction, heat, and other factors. The formula for mechanical efficiency (ŋmechanical​) is: ŋmechanical =(Actual Output Power/Theoretical Maximum Power)×100% If an engine has a theoretical maximum power output of 200 HP but only produces 180 HP, its mechanical efficiency would be: ŋmechanical =(180/200)×100%=90% High mechanical efficiency means that more of the energy produced during combustion is effectively converted into usable power, resulting in better overall performance and fuel economy.  Power Efficiencies and Measurements KEY TAKEAWAYS: Power Measurement: Understanding horsepower and torque is critical for evaluating engine performance, with horsepower indicating speed and torque reflecting pulling power. Efficiency Metrics: Thermal efficiency highlights how well fuel energy is converted to work, while mechanical efficiency assesses how much of that work is effectively harnessed for practical use.  Fuels and Combustion Fuel Types: ⚬ Gasoline: Common for smaller engines (cars, motorcycles). ⚬ Diesel: Used for larger, heavy-duty engines. ⚬ Alternative Fuels: Biodiesel, ethanol, natural gas, etc. Combustion Process: ⚬ Air-fuel mixture ignited in the combustion chamber. ⚬ Complete vs. Incomplete combustion: Affects engine performance and emissions.  Fuels and Combustion A diesel engine does not use a spark. It's also called a compression combustion engine, which means it has a higher compression ratio than a gas engine. The air-fuel mixture is squeezed so much that it explodes on its own. Essentially, a gasoline engine is a spark-fired combustion, and a diesel engine uses compression. Diesel cars also have more torque, which results in better fuel economy along with more impressive acceleration. One of the most important differences between gas and diesel engines is thermal efficiency, or the work that can be expected to be produced by the fuel put into the engine. A diesel engine is about 20% more thermally efficient than a gas engine. Diesel engines are often preferred in industries like construction, transportation and agriculture due to their durability, power and fuel efficiency. Diesel engines have higher torque generation and longer life spans compared to gas engines.  Engine Auxiliary Systems Cooling System: ⚬ Prevents the engine from overheating. ⚬ Components: Radiator, coolant, water pump. Lubrication System: ⚬ Reduces friction and wear on engine components. ⚬ Components: Oil pump, oil filter, oil pan. Fuel System: ⚬ Delivers the correct amount of fuel for combustion. ⚬ Components: Fuel tank, fuel pump, fuel injectors/carburetor.  Engine Operation and Maintenance Regular Maintenance Tasks: ⚬ Oil changes, air filter replacement, spark plug inspection. ⚬ Checking coolant and lubrication levels. Signs of Engine Issues: ⚬ Overheating, loss of power, unusual noises. Importance of Preventive Maintenance: ⚬ Extends engine life and improves efficiency.  ICEs are essential to modern machinery, with proper understanding of their components and operation being crucial for performance and maintenance. ABE-PC 312/ABE-PC 312 L TRACTOR NEXT >  ABE-PC 312/ABE-PC 312 L They provide power and mobility to perform a variety of tasks on the farm, improving productivity and efficiency. A tractor is an engineering vehicle Introduction to specifically designed to deliver a high tractive effort at slow speeds, for the Tractors purposes of hauling a trailer or machinery such as that used in agriculture for mechanized tasks such as plowing, tilling, < BACK planting, and hauling.. NEXT >  ABE-PC 312/ABE-PC 312 L Two and Four-Wheel Two-Wheel Drive (2WD): Tractors Four-Wheel Drive (4WD): Power is delivered to all Power is delivered to the rear four wheels. wheels. Suitable for heavy-duty Suitable for light-duty farm operations and larger, operations and smaller fields. rougher fields. Advantages: Lower cost, Advantages: Better easier to maneuver. traction and stability on Limitations: Less traction on rough or slippery terrain, wet or uneven terrain. higher pulling power. Limitations: Higher cost and more complex maintenance. < BACK NEXT >  ABE-PC 312/ABE-PC 312 L Two and Four-Wheel Tractors < BACK NEXT >  ABE-PC 312/ABE-PC 312 L Clutches and Brakes Clutch: Function - Disconnects the engine from the transmission to allow gear changes. Types - Dry single-plate clutch (common) vs. wet multi-plate clutch (in heavy-duty tractors). < BACK NEXT >  ABE-PC 312/ABE-PC 312 L Clutches and Brakes Brakes: Function: Stops or slows the tractor. Types: Mechanical brakes (for smaller tractors) vs. hydraulic brakes (for larger tractors). Differential braking: Enables the operator to brake each wheel independently for better steering control in tight turns or slippery conditions. < BACK NEXT >  ABE-PC 312/ABE-PC 312 L Transmission, Differential, and Final Drive Transmission Differential Final Drive Transmits power from the Allows wheels to rotate at Reduces the rotational engine to the wheels. different speeds, important speed of the transmission Types: Manual, hydrostatic, for turning. output and increases torque or automatic transmissions. to the wheels. < BACK NEXT >  ABE-PC 312/ABE-PC 312 L Hitches and Stability Hitches: Stability: Connect tractors to various Factors affecting stability: farm implements like plows, Load distribution, tire harrows, and trailers. inflation, and terrain. Three-point hitch: The most Proper ballasting: Balancing common type, providing the weight to improve lifting and lowering control. traction and reduce tipping risks. < BACK NEXT >  ABE-PC 312/ABE-PC 312 L Drawbar Pull Test Measures the maximum pulling power of the tractor. Evaluates traction, stability, and performance under load. Tractor PTO (Power Take-Off) Power Test Performance Measures the power output delivered to attached Tests implements. Ensures the tractor can efficiently power tools like mowers, balers, and pumps. < BACK NEXT >  ABE-PC 312/ABE-PC 312 L Safe Operation Procedures: Starting: Ensure parking brake is applied and controls are in neutral. Stopping: Gradual deceleration, using brakes appropriately, engaging parking brake. Tractor Operation Steering and Maneuvering: Use proper techniques when navigating turns and and Maintenance rough terrain. Maintenance: Routine checks: Engine oil, coolant levels, brake systems, tire pressure. Preventive measures: Regular inspections to avoid breakdowns and extend lifespan. < BACK NEXT >  ABE-PC 312/ABE-PC 312 L Summary < BACK