Intro to Marine Engineering 2E Episode 1 ppsx

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Intro to Marine Engineering 2E Episode 1 ppsx

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[...]... Figure 1. 4 Steam turbine machinery arrangement 1 Main boiler 16 Main condenser 2 FD fan 17 Main extraction pump 3 Main feed pump 18 Bilge/ballast pump 4 Turbo-alternator 19 Drains tank extraction pumps 7 SW-cooled evaporator 10 Hot water calorifier 21 Turbo alternator pump 11 FW pressure tank 22 LO cooler 12 Main turbines 24 LO bypass filter and pumps 13 Main gearbox 14 Thrust block 26 LO pumps 15 Main... the piston rises (Figure 2 .1( b)) Fuel is injected as the piston reaches top dead centre and combustion takes place, producing very high pressure in the gases (Figure 2 l(c)) The piston is now forced down by these gases and at bottom dead centre the exhaust valve opens The final stroke is the exhausting of the burnt gases as the piston rises to top dead centre to complete the cycle (Figure 2 .1( d)) The... Calibrated spring Drum Linkage to provide straight line movement of stylus Piston Cylinder Indicator piston Section showing indicator piston ^vindicator cord —I Coupling *—' nut to fasten onto indicator cock Figure 2.8 Engine indicator calibrated spring A magnifying linkage transfers the piston movement to a drum on which is mounted a piece of paper or card The drum oscillates (moves backwards and forwards)... many are still in operation 12 Diesel engines Fuel injection ends Fuel injection begins Exhaust ports close Exhaust ports open Figure 2.4 Two-stroke timing diagram " i- Upper /piston T_ f J ' Fuel ^injector k \Lower piston , I r Injection (a) t ^ ,t I 1 n Exhaust (b) Figure 2.5 Opposed piston engine cycle r h-Exhaust port •-Scavenge port 1 _ Scavenging (c) ITO i— r • 1 4 r 1 f _r -L-t J-4 Compressioi... strokes of the piston, or two revolutions of the crankshaft In order to operate this cycle the engine requires a mechanism to open and close the inlet and exhaust valves Consider the piston at the top of its stroke, a position known as top dead centre (TDC) The inlet valve opens and fresh air is drawn in as the piston moves down (Figure 2 .1 (a)) At the bottom of the stroke, i.e bottom dead centre (BDC),... indicator The shaft power is the power available at the output shaft of the engine and can be measured using a torsionmeter or with a brake The engine indicator An engine indicator is shown in Figure 2.8 It is made up of a small piston of known size which operates in a cylinder against a specially 16 Diesel engines Piston rod Calibrated spring Drum Linkage to provide straight line movement of stylus Piston... Adjustments may then be made to the fuel supply in order to balance the cylinder loads Torsionmeter If the torque transmitted by a shaft is known, together with the angular velocity, then the power can be measured, i.e shaft power = torque x angular velocity The torque on a shaft can be found by measuring the shear stress or angle of twist with a torsionmeter A number of different types of torsionmeter are described... engine is shown in Figure 2.7 The piston is solidly connected to a piston rod whkh is attached to a crosshead bearing at the other end The top end of the connecting rod is Exhaust manifold Turboblower Air inlet ports Crosshead Bottom end bearing Connecting rod A-frame Bedplate Crankshaft Figure 2.7 Cross-section of a two-stroke diesel engine Diesel engines 15 also joined to the crosshead bearing Ports are... 2 .10 (b) With uniflow scavenging the incoming air enters at the lower end of the cylinder and leaves at the top The outlet at the top of the cylinder may be ports or a large valve The process is shown in Figure 2 .10 (c) Each of the systems has various advantages and disadvantages Cross scavenging requires the fitting of a piston skirt to prevent air or exhaust gas escape when the piston is at the top... used to clean out or scavenge the exhaust 10 Diesel engines Figure 2.2 Four-stroke timing diagram gases and then to fill or charge the space with fresh air Instead of val*"js holes, known as 'ports', are used which are opened and closed by the sides of the piston as it moves Consider the piston at the top of its stroke where fuel injection and combustion have just taken place (Figure 2.3(a)) The piston . Burlington, MA 018 03 First published 19 83 Reprinted 19 85 Second edition 19 90 Reprinted 19 92 ,19 93 ,19 94 Revised 19 % Reprinted 19 98 (twice), 19 99,2000 (twice), 20 01, 2002,2003 © 19 96,. w0 h1" alt="" Introduction to Marine Engineering This page intentionally left blank Second Edition Introduction to Marine Engineering D. A. Taylor, MSc, BSc, CENG, FIMarE, FRINA Marine . propellers 200 12 Steering gear 211 13 Fire fighting and safety 2 31 14 Electrical equipment 253 15 Instrumentation and control 279 16 Engineering materials 326 17 Watchkeeping

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