Page 227 - CTS - Mechanic Diesel - TP

MECHANIC DIESEL - CITS

EXERCISE 13.4: Determining engine efficiency by Morse

Test using Dynamometer

Objectives

At the end of this exercise you shall be able to
• find the indicated power(ip) on four stroke four cylinder petrol engine by morse test.
• determine engine mechanical efficiency.

Requirements

Tools/Instruments Materials
• Trainees tool kit - 1 No. • Cotton waste - as reqd.
• Engine oil - as reqd.
Machines
• Engine coolant - as reqd.
• Multi cylinder four stroke Petrol engine - 1No. • Diesel - as reqd.
• Engine hydraulic dynamometer - 1No.

Procedure

Formulae used to calculate engine bp,ip& mechanical efficiency
1 BrakePower,BP=2ΠNT/60000KWIndicatedPower(IP)ofeachCylinders:
IP1=(BPT-BP2,3,4) KW

IP2=(BPT-BP1,3,4) KW
IP3=(BPT-BP1,2,4) KW
IP4=(BPT-BP1,2,3) KW
2 Total IP of the Engine, IPT=(IP1+IP2+IP3+IP4) in KW
MechanicalEfficiency, η mechanical=BPT/IPT

Morse test
1 Before starting the engine check the fuel supply, lubrication oil,and availability of coolingwater.
2 Set the dynamo meter to zero load.
3 Run the engine till it attains the working temperature and steady state condition. Adjust the dynamometer
load to obtain the desired engine speed. Record this engine speed and dynamometer reading for the BP
calculation.
4 Now cutoff one cylinder.Disconnect the fuel supply to the injector can do this.

5 Reduce the dynamometer load so as to restore the engine speed as at step 3.Record the dynamometer
reading for BP calculation.
6 Connect the cut off cylinder and run the engine on all cylinders for a short time.This is necessary for the steady
state conditions.
7 Repeat steps 4,5, and 6 for other remaining cylinders turn by turn and record the dynamometer readings for
each cylinder.
8 Bring the dynamometer load to zero,disengage the dynamometer and stop the engine.
9 Do the necessary calculations.

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