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Classification of Engine Innovative●entrepreneurial●global.

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Presentation on theme: "Classification of Engine Innovative●entrepreneurial●global."— Presentation transcript:

1 Classification of Engine Innovative●entrepreneurial●global

2 Classification of Engine  ICE are built with many different classifications.  For a given engine, using a four or two-stroke Otto or Diesel cycle, the classifications are characterized by: piston-cylinder geometry valve arrangement air Intake fuel delivery system cooling system Innovative●entrepreneurial●global

3 Classification of Engine Cont. ENGINE CLASSIFICATIONS Piston Cylinder Geometry Fuel Delivery System Air Intake Valve Arrangement Cooling System In-line Horizontally Opposed Vertically Opposed ‘V’ engine Radial Carburetor TBI MPI GDI NA Supercharged Turbocharged L-Head I-Head Water Air Innovative●entrepreneurial●global

4 Arrangement of Cylinder The choice of a given arrangement depends on a number of factors and constraints, such as engine balancing and available volume. The in-line engine is the most popular as it is the simplest to manufacture and maintain. The V engine is formed from two in-line banks of cylinders set at an angle to each other, forming the letter V. A horizontally opposed or flat engine is a V engine with 180° offset piston banks. A radial engine has all of the cylinders in one plane with equal spacing between cylinder axes. Radial engines are used in air-cooled aircraft applications since each cylinder can be cooled equally. Since the cylinders are in a plane, a master connecting rod is used for one cylinder, and articulated rods are attached to the master rod.  The reciprocating motion of the connecting rod and piston creates inertial forces and moments that need to be considered in the choice of an engine configuration. V In line Opposed piston Radial Horizontally

5 Innovative●entrepreneurial●global Number of Cylinder Single-cylinder engine gives one power stroke per crank revolution (2 stroke) or two revolutions (4 stroke). The torque pulses are widely spaced, and engine vibration and smoothness are significant problems. Multi-cylinder engines spread out the displacement volume amongst multiple smaller cylinders. Increased frequency of power strokes produces smoother torque characteristics. Engine balance (inertia forces associated with accelerating and decelerating piston) better than single cylinder. Most common cylinder arrangements: - In-line 4-cylinder - In-line 6-cylinder - V-6 and V-8

6 Innovative●entrepreneurial●global Rotary Engine

7 Innovative●entrepreneurial●global Valve Arrangement Gases are admitted and expelled from the cylinders by valves that open and close at the proper times, or by ports that are uncovered or covered by the piston. Poppet valve is the primary valve type used in internal combustion engines since they have excellent sealing characteristics. The poppet valves can be located either in the engine block or in the cylinder head, depending on manufacturing and cooling considerations. Older automobiles and small four-stroke engines have the valves located in the block, a configuration termed underhead or L-head. Currently, most engines use valves located in the cylinder head, an overhead or I-head configuration, as this configuration has good inlet and exhaust flow characteristics.

8 Innovative●entrepreneurial●global Poppet Valve A camshaft that rotates at half the engine speed for four-stroke engine controls the valve timing. Lobes on the camshaft along with lifters, pushrods, and rocker arms control the valve motion. The valve timing can be varied to increase volumetric efficiency through the use of advanced camshafts that have moveable lobes, or with electric valves. With a change in the load, the valve opening duration and timing can be adjusted.

9 Innovative●entrepreneurial●global L and I Head Valve L-head (Valve in Block)I-head (Valve in Head)

10 Innovative●entrepreneurial●global Valve and Cam Arrangement

11 Innovative●entrepreneurial●global Air Intake NA Naturally Aspirated Most automobile used NA engine. Air or fuel-air mixtures are forced into the cylinders by vacuum caused by cylinder movement. NA engines generally gives less power than either turbo or supercharged engines of the same engine displacement and development level but tend to be cheaper to produce.

12 Innovative●entrepreneurial●global Air Intake Supercharge  The compressor raises the density of the incoming charge so that more fuel and air can be delivered to the cylinder to increase the power. Supercharged Supercharging is mechanical compression of the inlet air to a pressure higher than standard atmosphere by a compressor powered by the crankshaft.

13 Innovative●entrepreneurial●global Air Intake Turbocharge  the engine is more efficient because energy from the exhaust gas is used to increase the efficiency.  a smaller engine can be constructed to produce higher power because it is more efficient. Most large and medium size diesel engines are turbocharged to increase their efficiency. Turbocharged In turbo charging exhaust gas leaving an engine is further expanded through a turbine that drives a compressor. The benefits are:

14 Innovative●entrepreneurial●global Example: Turbocharged Proton Exora Bold with Campro CFE engine CFE ?= charge fuel efficiency Light-pressure intercooled turbocharged version of the 1.6-litre CamPro engine

15 Innovative●entrepreneurial●global

16 Fuel Delivery System Some fuel systems use a carburetor. It sits on top of the engine intake manifold. The carburetor mixes the air and fuel into a combustible mixture. Instead of carburetor, most engines have electronic fuel injection (EFI) system. An electronic control module (ECM) or computer, controls one or more fuel injectors. When the engine needs fuel, a signal from the ECM opens the injector. There are 3 types of electronic fuel injection:  Throttle-body injection (TBI)  Multipoint Port Injection (MPI)  Gasoline Direct Injection (GDI) A throttle body injector is a fuel injector located at the intake manifold before the manifold branches to the individual cylinders. Due to its distance from the cylinders, it injects a continuous spray of fuel into the manifold.

17 Innovative●entrepreneurial●global Fuel Delivery System Cont. Port fuel injectors are located in the intake port of each cylinder just upstream of the intake valve, so there is an injector for each cylinder. The port injector does not need to maintain a continuous fuel spray, since the time lag for fuel delivery is much less than that of a throttle body injector. Direct injection spark ignition engines are available on some production engines. With direct injection, the fuel is sprayed directly into the cylinder during the late stages of the compression stroke. Compared with port injection, direct injection engines can be operated at a higher compression ratio, and therefore will have a higher theoretical efficiency.

18 Innovative●entrepreneurial●global Fuel Delivery System Cont. GDI

19 Innovative●entrepreneurial●global Cooling System Some type of cooling system is required to remove the approximately 30% of the fuel energy rejected as waste heat. There are two main types of cooling systems: water and air cooling. The water cooling system is usually a single loop where a water pump sends coolant to the engine block, and then to the head. Warm coolant flows through the intake manifold to warm it and thereby assist in vaporizing the fuel. The coolant will then flow to a radiator or heat exchanger, reject the waste heat to the atmosphere, and flow back to the pump. When the engine is cold, a thermostat prevents coolant from returning to the radiator, resulting in a more rapid warm-up of the engine. Water-cooled engines are quieter than air-cooled engines, but have leaking, boiling, and freezing problems. Engines with relatively low power output, less than 20 kW, primarily use air- cooling. Air cooling systems use fins to lower the air side surface temperature

20 Innovative●entrepreneurial●global Cooling System Cont.


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