IC -ENGINE BY PROF. AVINASH 5 TH S E M M E C H A N I C A L MECH_INT CLASSES
CONTENTS 1. 2. 3. 4. 5.
6. 7.
8.
Nomenclature of ICE Engine testing Types of power Power measurement tests ICE efficiencies BSFC Heat balance sheet Pollution control
NOMENCLATURE Cylinder bore(D) Stroke(L) Dead centre Swept volume
Clearance volume Cylinder volume Compression ratio
ENGINE TESTING To get information that cannot be calculated To confirm the design data To meet customer specifications of power and fuel
consumption Two types of tests: 1. Commercial tests 2. Thermodynamics tests
Commercial tests Rated power with guaranteed fuel consumption in
kg/ Kw-hr The quantity of lubricating oil consumed on brake power per Kw-hr Quantity of cooling water in kg/ kw-hr Steadiness of engine under varied load conditions Overload carrying capacity of engine
Thermodynamic tests Used to measure various losses due to different
causes To measure mechanical and thermal efficiencies of engine Draw heat balance account Required data 1. IP, BP, FC &CV 2. Heat carried away by cooling water 3. Heat carried by exhaust gas
TYPES OF POWER A. INDICATED POWER IP = P L A N B. BRAKE POWER BP= (W-S)R * 2 π N
CONTD. C. FRICTIONAL POWER FP = IP - BP
Morse test Used for calculating FP in a 4S-engine Procedure: First engine is run at constant speed and Brake
power of the engine is measured when all the cylinders are working (I1+ I2+I3+I4) = (BP) ENGINE + (F1+F2+F3+F4) The first cylinder is cut off, so
(I2+I3+I4) = (BP) 2,3,4 + (F1+F2+F3+F4)
Contd. Now only cylinder 2 is cut-off
(I1 +I3+I4) = (BP) 1, 3, 4 + (F1+F2+F3+F4) Cylinder 3 is cut off (I1+ I2 +I4) = (BP) 1,2,4 + (F1+F2+F3+F4) Cylinder 4 is cut-off (I1+ I2+I3) = (BP) 1,2,3 + (F1+F2+F3+F4) Hence, I1 = (BP) ENGINE – (BP)2,3,4 I2 = (BP) ENGINE – (BP)1,3,4
Contd. I3 = (BP) ENGINE – (BP)1,2,4 I4 = (BP) ENGINE – (BP)1,2,3 Thus IP of engine is IP = (I1+ I2+I3+I4) And FP = IP - (BP) ENGINE And
Efficiencies in ICE
Contd.
BSFC:
Heat balance Sheet Heat supplied
kJ/min
%
Heat distributi on
kJ/min
1. Heat supplied by the fuel
100
1.Heat eq. ` of BP 2. Heat in cooling water 3. Heat in exhaust gases 4. Unaccounte d heat
Total
100
Total
%
100
Pollution control Pollutants in Exhaust of petrol and diesel engine(SS) Effect of pollution in Environment(SS) Exhaust gas analysis Pollution control norms
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