DIESEL PLANT.pdf - Diesel Power Plant ME 521A Engu2019r...

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Diesel Power Plant ME 521A Eng’r Maurice O. Licdan
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Internal Combustion Engines Application of I.C. Portable generating units may be moved from site to site where electrical power is required temporarily Standby units , normally idle, which can be activated when there is a failure of the central station power where a power interruption would mean financial loss or danger
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Internal Combustion Engines Application of I.C. Engine-generator units installed in power plants where they are the normal primary source of electrical power for public, industrial or institutional use
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Internal Combustion Engines Features Use of piston and cylinder to create a variable volume chamber in which to work out the cycle Gaseous working medium Open thermal cycles (air and fuel into the engine, products of combustion out the engine) Two or four stroke cycles Cyclic rather than uniform power output necessitating multiple cylinders and or heavy flywheels for steady delivery
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BASIC TYPE OF IC ENGINE
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Classification of IC Engines. 1. According to cycle of operation Two Stroke Engine Four Stroke Engine 2. According to cycle of combustion Otto Cycle Engine(combustion at constant volume) Diesel Cycle Engine(combustion at constant pressure) Dual Combustion or semi diesel cycle engine. 3. According to arrangement of Cylinder. Horizontal Engine Vertical Engine V-Type Engine Radial Engine
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4 . According to their Uses Stationary Engine Portable Engine Marine Engine Automobile Engine Aero Engine 5. According to fuel employed and method of fuel supply to the engine. Oil Engine Petrol Engine Gas Engine 6. According to method of ignition Spark ignition Compression ignition
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7. According to speed of the engine Low speed Medium Speed High Speed 8. According to method of cooling Air Cooled Water Cooled 9. According to number of cylinders Single cylinder Multi Cylinder
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FUNCTION (a) FOUR STROKE (b)TWO STROKE
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DIESEL CYCLE 1892, Dr. Rudolf Diesel described an engine to operate on Carnot Cycle by the use of coal dust
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Diesel Engine Advantages Low fuel cost No long warming up periods No standby losses Uniformly high efficiency of all sizes Simple plant lay out Needs no large water supply
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Diesel Engine Some disadvantages Increase in capacity increases the plant floor area and cost nearly the same proportion unlike steam turbines Large steam central stations have net thermal efficiencies nearly as high as that of the diesel engine Noise- can be cancelled by proper silencers
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cutoff ratio (r c ) - the ratio of the cylinder volumes after and before the combustion process diesel engines operate at much higher compression ratios and thus are usually more efficient than the spark-ignition
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only air is compressed during the compression stroke 12 and 24 Less refined fuel can be used in diesel engines
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mean effective pressure
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