Download AKTU (Dr. A.P.J. Abdul Kalam Technical University (AKTU), formerly Uttar Pradesh Technical University (UPTU) B-Tech 4th Semester (Fourth Semester) 2015-16 2605 Applied Thermodynamics Question Paper
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B.TECH.
Theory Examination (Semester?IV) 2015-16
APPLIED THERMODYNAMICS
T ime : 3 Hours Max. Marks : 100
Note: 1. Use of steam table is permisible.
2. Assume, any missing data suitably.
Section-A
Q1. Attempt all question. (2X10=20)
a) De?ne the discharge coef?cient and critical velocity of
nozzle.
b) Why compounding is necessary in steam turbines?
0) De?ne adiabatic ?ame temperature and isothermal
compressibility.
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d)
Why modi?ed Rankine cycle is not used in steam
turbines?
e) What are main requirements of a good steam boilers?
f) Make comparison between arti?cial over natural draught?
g) De?ne the stage ef?ciency and speed ratio of the steam
turbine.
h) What is bleeding?
1) State the difference between Boiler mountings and ac-
cessories.
j) De?ne the term dryness fraction.
Section-B
Q2. Attempt any ?ve. (5X10=50)
a) Dry saturated steam at a pressure of 6 bar ?ow?s through
nozzles at the rate of 4.5 Kg / sec and discharges at a
pressure of 1.6 bar. The loss due to ?iction occurs only
in the diverging portion of the nozzle and its magnitude
is 12 % 0f the total isentropic enthalpy drop. Assume
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b)
d)
the isentropic index of expansion 11 = 1.135.Determine
the cross sectional area at the throat and exit of the
nonles
What does the Clausius - Clapeyron equation signify?
Derive the relation and discuss its application.
A boiler house has natural draught chimney of 20 mm
height. Flue gases are at temperature of 380?C and
ambient temperature is 27?C. Determine the draught in
mm of water column for maximum discharge through
chimney and also the air supplied per Kg of ?lel.
What is purpose of governing of steam turbines? Explain
the various methods used for governing of steam tur-
bines, in brief.
What is basic di?erence between closed cycle and open
cycle gas turbines? With the help of neat sketch, de-
scribe the working of a simple constant pressure open
cycle gas turbine, in brief.
Draw the velocity diagram of a velocity compound im-
pulse turbine. Show the calculations for ?nding out the
tangential force, axial thrust blade ef?ciency and stage
efficiency for both the impulse and reaction turbine.
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g)
h)
A gas turbine works on Brayton cycle, gas is enters the
turbine at a pressure of 6OOkN/rn2 and a temperature
1200K. The gas expands in the turbine isentropically (Y
= 1.4) to the atmospheric pressure 100kN/m2. Calcu-
late
(i) Air standard e?iciency 0f the cycle.
(ii) The temperature of the exhaust gas, if
(iii) Temperature of air at the exit end of compressor.
Assume that the compression process isentropic
atmospheric temperature is 300K.
System at 15 bar and 300?C is throttled till its pressure
becomes 10 bar and then expanded isentropically pass-
ing through a turbine until pressure falls to 1 bar. The
exhaust steam ?om the turbine is used for process work
(i) Find the condition of the steam leaving the turbine
and work done per kg. of steam passing through
the turbine.
(ii) If the steam is directly passed through the turbine
them ?nd the work done per kg of steam.
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Section-C
Attempt any two. (2X15=30)
Q3. Discuss the effect of inlet pressure and temperature of steam
0n Rankine cycle. Write the advantages of reheating of the
steam and at what pressure (in terms of initial pressure)
reheating is generally done to obtain best results. Why gener-
ally one open feed water is used in Rankine cycle and What is
it called?
Q4. (i) Explain the terms 'State Point locus' and 'Reheat
Factor'. For six stage 1 turbine ?nd Out the reheat
factor With the help of H - S plot and prove that
(Internal ef?ciency = Stage ef?ciency X Reheat factor
olThe turbine.)
(i1) For a constant pressure closed cycle gas turbine, derive
the mathematical Expression of optimum pressure ratio
for maximum cycle thermal e?iciency.
Q5. An inventor claims to have developed an ef?cient hot engine
Which would have a heat source at 1000?C and rejects heat
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to a sink at 50?Cand gives an e?iciency of90%.Justify Whether
his claim is possible. Draw schematic and T?S diagrams of an
open cycle gas turbine plant Which has been provided with
perfect intercooljng, reheating and regeneration arrangements.
(6)
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This post was last modified on 29 January 2020