TE LAB-RETARDATION TEST ON A SLOW SPEED DIESEL ENGINE

 

Ex.No:                                                                                                                                Date:

RETARDATION TEST ON A SLOW SPEED DIESEL ENGINE

 

Aim: To conduct a retardation test and determine the frictional power of the single cylinder diesel engine at the given speed.

 

Theory: This test involves the method of retarding the engine by cutting the fuel supply. The engine is made to run at NO load and at the rated speed. When the engine is running under steady operating conditions the supply of fuel is cut-off and simultaneously the time of fall in speeds say 20%, 40%, 60%, 80% of the rated speed is recorded. This test is repeated with 50% load on the engine.

 

Specification:

Four stroke single – cylinder diesel engine, water cooled engine. 

Rated speed                   : 650 rpm 

Starting by                      : hand cranking the crank shaft 

Loading                           : Rope brake drum, by dead weights and spring balance 0 - 10 Kg 

Bore diameter               : 0.210 m

Stroke length                 : 0.110 m

Procedure:

§ Check the fuel level. 

§ Check lubricating oil level. 

§ Open the three way cock, so that the fuel flows to the engine.

§ Supply cooling water through the inlet pipe. 

§ Start the engine, adjust the speed by screwing and unscrewing the governor nut.

§ Allow cooling water in the brake drum. 

§ Adjust cooling water to the engine to the required value.

Observation Table:

S.No	Drop. in speed in rpm	Time taken t2 at no load	Time taken t3 at part load
1	700 to 600
2	700 to 500
3	700 to 400
4	700 to 300
5	700 to 200

Formulae:

Graph:

Speed Vs Time (No Load and Half Load)

 

Pre Lab Questions:

1.      What are the 4strokes of SI engines?

2.      What is the working cycle of SI Engine?

3.      List out the performance parameters?

4.      Indicate the different types of loads?

5.      Differentiate SFC and TFC?

 

Post Lab Questions:

1.      Differentiate brake power and indicated power?

2.      Define brake thermal efficiency?

3.      Indicate mechanical efficiency in terms of BP and IP?

4.      Explain the procedure for retardation test?

5.      What is the type of dynamometer used for measuring the motor output? 

 

Conclusion:

 

PO Attainment:

Composed By:  

 R.Satheesh, M.E., Asso.Prof.,