Andhra University 2009-2nd Year B.E ./B.Tech THERMAL PRIME MOVERS - Question Paper

II Year B.E./B.Tech Degree exam
THERMAL PRIME MOVERS
Electrical & Electronics Engineering
Time : 3 hours Maximum : 75 Marks
ques. one is compulsory
ans any 4 from ques. two to 8
All ques. carry equal marks


1. a. State Boyles legal regulations and Charles legal regulations and prove characteristic
formula is PV = mRT
b. elaborate mountings and accessories in a boiler and
differentiate ranging from the two.
c. explain in brief classification of compound steam engines.
d. Briefly explain the air fuel ratio requirements of a petrol
engine from no load to full load.
e. Distinguish ranging from impulse turbine and reaction turbine.
2. a) What is dryness fraction? discuss with a neat sketch the
working of a separating oalorimeter.
b) Dry saturated steam at a pressure of 1.1 bar expands
polytropically according to PV1.13 =constant, to a pressure
of one bar. Determine (i) the final condition of steam and (ii)
the amount of heat transferred per kg of steam and (iii) the
change of entropy.
3. a) elaborate the differentiating features ranging from water tube
and fire tube boiler
b) A boiler is given with a chimney of 25 m height. The
boiler house temperature is 300C and the temperature of
the gas leaving the chimney is 3000C . If the air supplied to
II Year B.E./B.Tech Degree exam
THERMAL PRIME MOVERS
Electrical & Electronics Engineering
Time : 3 hours Maximum : 75 Marks
ques. one is compulsory
ans any 4 from ques. two to 8
All ques. carry equal marks
20
the boiler is 19kg per kg of fuel, compute (i) draught in mm
of water column (ii) velocity of gas passing through the
chimney with 50% loss of draught due to friction.
4. a) define with a neat sketch the working of a Wolf kind
compounding steam engine
b) A single cyllinder double acting steam engine has a piston
diameter 250mm, stroke 400mm and diameter of the piston
rod 50 mm. the mean effective pressure on both sides of the
piston is 2.5 bar. Determine the indicated power when the
engine runs at 200 rpm.
5. a) discuss with a neat sketch the working of a 4 stroke
S.I.engine
b) An air standard dual cycle has a compression ratio of 10 the
pressure and temperature at the beginning of compression
are one bar and 270C the maximum pressure reached is 42
bar and the maximum temperature is 15000C determine (i)
temperature at the end of constant quantity heat addition (ii)
cut-off ratio (iii) work done per kg of air (iv) cycle efficiency.
presume cp =1.004kJ / kg K and
cv = 0.717 kJ / kg K for air.
6. a) With a neat sketch, discuss the working of a simple
carburetor.
b) discuss the reasons for cooling an engine, discuss any two
kinds of cooling systems.
7. a) Briefly discuss with a neat sketch throttle governing of steam
engines.
b) Steam enters a group of convergent - divergent nozzles at a
pressure of 22 bar and with a temperature of 2400C , the
21
exit pressure is four bar and 9% of the total heat drop is lost in
frictioin. The mass flow rate is 10 kg/s and the flow up to
throat may be presumed frictionless. compute (i) throat and
exit velocities (ii) throat and exit areas.
8. a) Draw a neat sketch of locomotive boiler, tag the parts and
discuss its working.
b) elaborate mountings accessories in a boiler. discuss any two
mountings and accessories in a boiler.

Earning:   Approval pending.