STUPIDSID
1 (a)
Obtain equation of critical pressure ratio of nozzle and explain its significance. Calculate its value for dry and saturated steam.
7 M
1 (b)
A group of six nozzles receives steam at 30 bar and 300°C. The steam flow rate is 5 kg/s and it expands up to 3 bar. For metastable expansion,
find
(i) diameter of nozzle at exit neglecting friction and
(ii) degree of subcooling.
(i) diameter of nozzle at exit neglecting friction and
(ii) degree of subcooling.
7 M
2 (a)
Differentiate clearly between Impulse and Reaction turbine. For an Impulse turbine, obtain expression for work done and axial thrust.
7 M
Solve any one question from Q2(b) & Q2(c)
2 (b)
The steam is supplied to a de- Laval turbine at a velocity of 950 m/s at
an angle of 20°. Mean blade velocity is 350 m/s and the blades are
equiangular. The mass flow rate of steam is 0.5 kg/s. If blade velocity
coefficient is 0.8, determine blade efficiency, power developed and
stage efficiency, if nozzle efficiency is 95%.
7 M
2 (c)
At a stage of 50% reaction turbine, the pressure is 1.4 bar and steam is 0.9 dry. The inlet and outlet angles are 357deg; and 20° respectively. The
blade velocity is 67 m/s. Determine the blade height, if the ratio of drum
diameter to blade height is 8.0 and mass flow rate is 4.8 kg/s. Also find the power developed.
7 M
Solve any two question from Q3(a), Q3(b) & Q3(c), Q3(d)
3 (a) (i)
Explain velocity compounding of Impulse turbine with the help of sketch and explain its advantage.
4 M
3 (a) (ii)
Explain working of Pass- out turbine.
3 M
3 (b)
In a Reheat Rankine cycle, the steam at 150 bar and 5007deg;C expands
through the high pressure turbine. It is then reheated at constant
pressure of 40 bar to 5007deg;C and expands through the low pressure
turbine to a condenser pressure of 0.1 bar. Find quality of steam at
outlet and thermal efficiency. Neglect pump work.
7 M
3 (c) (i)
What is function of governing system of steam turbine? Compare throttle governing with nozzle governing.
4 M
3 (c) (ii)
Explain working of Back- pressure turbine.
3 M
3 (d)
Explain Regenerative feed heating with the help of sketch of steam power plant. How does the feed water heating increases efficiency of Rankine cycle?
7 M
Solve any two question from Q4(a), Q4(b) & Q4(c), Q4(d)
4 (a)
Derive an expression for optimum pressure ratio for maximum work output in ideal Brayton cycle.
7 M
4 (b)
Air enters in compressor of gas turbine plant at 1 bar, 300 K with a volumetric flow rate of 5 m3/s. The pressure ratio is 10 and turbine inlet
temperature is 1400 K. If isentropic efficiency of compressor is 0.8 and
that of turbine is 0.85, find thermal efficiency of plant and power
developed in kW.
7 M
4 (c)
Derive an expression for thermal efficiency of gas turbine plant and show that it is independent of mass flow rate of air through the plant.
7 M
4 (d)
A gas turbine plant draws air at 1 bar and 300K. Air is compressed to 4 bar and then heated to temperature of 900 K. The isentropic efficiency
of compressor is 81% and that of turbine is 86%. Neglecting mass of
fuel, determine overall efficiency of the plant
(i) without regenerator and
(ii) with regenerator of 75% effectiveness.
Take CP=1.005 kJ/kg K and γ=1.4 for air and gases.
(i) without regenerator and
(ii) with regenerator of 75% effectiveness.
Take CP=1.005 kJ/kg K and γ=1.4 for air and gases.
7 M
Solve any two question from Q5(a), Q5(b) & Q5(c), Q5(d)
5 (a)
Draw schematic diagram of turboprop engine and explain its working. List its advantages and disadvantages also.
7 M
5 (b)
Enlist different losses of steam turbine and explain them briefly.
7 M
5 (c)
Explain with neat sketches, different methods used to improve efficiency and specific work output of open cycle gas turbine plant.
7 M
5 (d)
Explain working of Pulsejet engine with the help of its schematic diagram. State its advantages and disadvantages.
7 M
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