Download AKTU (Dr. A.P.J. Abdul Kalam Technical University (AKTU), formerly Uttar Pradesh Technical University (UPTU) B-Tech 4th Semester (Fourth Semester) 2014-15 Applied Thermodynamics Question Paper
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(Following Paper ID and Roll No. to be ?lled in your Answer Book)
PAPER ID : 140402
Roll No.
B. Tech.
(SEM. IV) THEORY EXAMINATION, 2014-15
APPLIED THERMODYNAMICS
Time : 3 Hows] [Total Marks : 100
Note: (i) Attempt all questions very carefully.
(i)_ All questions cany equal marks
(.5) Use of Steam Table/Mollier chm and
Calculator is allowed.
(iv) Be precise in your answer.
1 Attempt any two parts of the following: 10XZ=20
(a) What is the physical signi?cance of thanmdyrmnic
relations? Prove 1111' Maxwell relations using
equations based on thermodynamics laws.
(b) Ovaacatainrangeofplmnmmdtemperatm
theequation ofstate ofaoertaingasisprac?bed
bythe relation
v .= (RT/p) ? (0/ T3) where C is a constant.
140402] 1 [ Contd...
(C)
2 Attempt any two parts of the following:
(a)
(1))
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Set up expressions for a change in enthalpy and
entropyofthe gas. Considerthechangetoocwr
under isothermal conditions.
The following data pertains to the test run made
in the laboratory to determine the calori?c value
of a gaseous ?lel by Junker's gas calorimeter:
Gasbumtinthecalorimeter=1011ters
Gas temperature and pressure at inlet = 20?C and
50mm of water above atmospheric
Cooling water passing through the calorimeter = 8 liters
Inlet and outlet temperature of water = 15?C and 25?C
Steam condensed during test run = 1000
Determine the higher and lower calori?c value of
?le]. sample. You may take barometric pressure
as 750m of mercury and latent heat of
vaporization of water as 2465KJ/kg.
10XZ=20
List the di??erenoes 111 between ?re tube and water
tube boiler. Explain working and construction of
Locomotive boiler with a neat sketch.
De?ne equivalent evaporation.
The following data are obtained in a boiler trial:
Mass and temperature of feed water: 680 kg/hr
and 20?C Steam pressure and its temperature:
15 bar and 300?C
2 [ Coma...
:9
140402] *
Coal used and its calori?c value: 98 kg/hr and
26500 KJ/kg Flue gas formed and its temperatm?e
at chimney: 18 kg/kg of coal supplied and 300?C
Ash and unbumt coal in ash-pit: 44 kg/hr with
2200 KJ/kg calori?c value
Mean speci?c heat of ?ue gases and feed water:
1 KJ/kg K and 4.187 KJ/kg K
Ifthe ambient temperature in the boiler room is 28?C.
Determine:
(1) Boiler e?'lciency
(ii) Equivalent evaporation ?om and at 100?C
(iii) Percentage heat unaccounted for
(iv) Draught produced in mm of water column
if the height of chimney is 50 m.
The following observations are reeorded during
a test on a steam condenser:
Reeetdedemdmservacmnn= 71cm. (1ng Barometric
reading = 76.5 cm of Hg, Mean condenser
temperature = 34?C, Temperature of hot well = 285?C,
Condensate collected = 1800 kg/?hour, Flow rate of
cooling water = 57500 kg/hour, Inlet temperature of
cooling water = 85?C, Outlet temperature of cooling
water = 26?C. Determine:
3 [ Contd...
3 Attempt any two parts of the following:
(1) Vacuum ef?ciency
(11) Condenser ef?ciency
(iii) Dryness fraction of steam entering the
condenser
(iv) Mass of air leakage perm3 of the condenser
volume. '
(a) Asteamengineof30mldiameterand500m
140402]
stroke length is supplied steam at 10 bar and
300?C. The steam expands adiabatically to 0.7
bar and then release occurs at constant volume
to a condenser a1 0.3 bar. Represent the cycle
on P-V and T-S plots and compare it with the
corresponding diagram for the complete Rankine
cycle. Determine:
G) The modi?ed Rankine cycle e?iciency:
(ii) The Rankine e?iciency corresponding to
complete expansion.
4 [ Contd...
10X2=20
(b) A supersonic nozzle is to be designed for air ?ow
(C)
4 Attempt any two parts of the following:
(a)
(b)
140402]
with Mach number 3 at the exit section which
is 250 mm in diameter. The premerand
temperature of air at the nozzle exit are
8.5 kN/m2 and 215 K Make calculations for:
(a) Reservoir pressure?and'tempemune ?
(b) Throat area.
Prove expression for mass ?ow rate per unit area
of steam in a noule. Also give condition for
(i) Whatare effects ofpressmeandtmnpemune
on Rankine cycle ef?ciency and output?
Explain showing in cycle.-
(in) Compare impulse and reaction turbine.
In a regenerative feed heating cycle, the- steam
enters the turbine at 25 bar and 250?C. The
condenser pressure is 0.05 bar. The steam is bled
011' for feed water heating for a closed heater at
3.5 barandforanopenheateratOJbar. The
condensate 9f the closed heater is discharged into
5 [ Conul...
10X2=20
(C)
s
; (a) '
(b)
140402]
Attempt any two pans of the following:
the low pressure open heater. Calculate the
thermal e?iciency 0f the cycle. Neglect the pump
work. Also determine the corresponding Rankine
cycle ef?ciency.
In a Parson's reaction turbine the rotor of 1 m
diameter nms at 3000 rpm. Detexmine the isentropic
enthalpy drop in the stage considering stage
= ef?ciency of0.80,\ ratio of linear velocity of blade
to absolute velocity at inlet of moving blade=0.7,
blade outlet angle = 20?.
Classify Gas turbines. Explain the cycle on which
Gas turbine works? Also, explain it with reheat
and regeneration showing its 'e??ects when uSed
simultaneously in a single cycle.
Air enters the compressor of a gas tulbine plant
operating on Brayton cycle at 1 bar pressure and
300 K temperature. The pressure ratio is 5 and
the maximum cycle temperamre is limited to
1075 K. Ifthe CWT and turbine ef?ciencies
are 80% and 85% respectively. Make calculations
for the net work output, cycle ef?ciency and the
work? ratio.
6 [Contd... -
10X2=20
140402]
(C)
Compare Jet engine and Propeller engine. Explain
working and consu-uction of turbojet engine.
[3600]
This post was last modified on 29 January 2020