RTU 2016 Question Paper Semester VI Mechanical Engineering Steam Engineering

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Total No of Pages: I
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B. Tech. vI Sem. (Main & Back) Exam., AprivMay-20\6
Mech. Engineer
Erl 6ME5A Steam Engineering
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Time: 3 Hours Maximum Marks: E0
Min. Passing Marks (Main & Back): 26
I nstractions ta Candidates :'

Attempt any ft,ve questions, selecting one questi.on from each unil'
All
Questions carry equal marks. schematic
diagrams must be shown
wherever necessary. Any data you feel missing may suitably be assumed
and stated clearlY.
IJnits o.f quantities used/ calculated must be stated clearly.

Use of following supporting material is permitted during examination'

1. Steam table & mollies chart 2. Property tables

State how the boilers are classified? t6l
Q.1 (a)
of a
(b) Give an outline sketch showing the arrangement of water tubes and furnace
gases and water
Babcock and Wilcox boiler. Indicate on it the path of the flue
heater'
circulation. Show the positions of fusible plug, blow off cock and super
Mention the function of each. t10l

OR
Why high pressure boiler are used? t61
Q.2 (a)
(b) what is Fluidised Bed Combustion system? Sketch and describe a Fluidised Bed
combustion (FBC) sysrem. State the advantages of FBC system. t10l

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UNIT.II
Q.3 (a) Define Mach Number. What is its significance in design of difftrsers and
nozzles? t6I
(b) Air enters a nozzle like that shown in Figure at a temperature of 195' C and a
velocity of 100 m/s. If the air exits to the atmosphere where the pressure is 85
kPa. Find

(i) The exit temperature

(ii) The exit velocity
(iii) The exit diameter l10l

500 kPa

-----------|

------+
-.--.+

-_>
-------->

OR
Q.2 (a) Derive the expression for critical pressure ratio in case of nozzles. t8l
(b) Air at 10oC and 80 kPa enters the diffuser of a jet engine steadily with a velocity
of 200 m/s. The inlet area of the diffuser is 0.4 m2. The air leaves the diffuser
with a velocity that is very small compared with the inlet velocity. Determine

(i) The mass flow rate of the air and
(ii) The temperature of the air leaving the diffuser. t8l

Q.3 (a) Explain diagram efficiency and Gross stage efficiency. t61

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(b) What do you understand by compounding for pressure and velocitY in case of
impulse turbine? Why and how it is achieved? l10l

Q.3 (a) Why governing of turbines is essential? l4l
(b) In a simple steam impulse turbine, steam leaves the nazzle with a velocity of
1000 m/s at an angle of 20o to the plane of rotation. The mean blade velocity is

60Vo of velocity of maximum efficiency. If diagram is 707c and axial thrust is

39.24 N/kg of steam/sec, estimate:

(i) Blade angles

(ii) Blade velocity co - efficient
(iii) Heat lost in kJ in friction per kg. tl21

Q.4 (a) What do you understand by 'degree of reaction'? t4l

(b) At a particular ring of a reaction turbine the blade speed is 67 m/s and the flow of
steam is 4.54 kg1s, dry saturated, at 1.373 bar. Both fixed and moving blades

have inlet and exit angles of 35o and 20o respectively. Deterrnine:

(i) Power developed by the pair of rings.

(ii) The required blade height which is to be one tenth of the mean blade ring
diameter.

(iii) The heat drop required by the pair if the steam expands with an efficiency
of807o. l12l

OR

Q.4 (a) What do you understand by regenerative f'eed heating cycle? t4l

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(b) Explain the difference between ideal and actual Regenerative cycles by showing
the process on T - s and h - s Diagram. Why actual Regenerative cycle differs
from ideal Regenerative cycle? lr2)

Q.s (a) What are the advantages and disadvantages of reheating of steam? l4l
(b) In a condenser test the following observations were made: lt21
Vacuum = 69 cm of Hg: Barometer = 75 cm of Hg
Mean temperature of condenser = 35oC: Hot well temperature = 28"C

Amount of cooling water = 50,000 kglhr. Inlet temperature = l7"C
Outlet temperature = 30oC: Amount of condensate per hour = 1250kg
Find

(i) 'fhe amount of air present per m3 of condenser volume.
(ii) The state of steam entering the condenser.
(iii) The vacuum efficiency.
R for air = 287 JlkgK.

OB
Q.5 (a) Explain the working of binary vapour cycle with a neat sketch. l8l
(b) What is condenser? Name the different types of condenser. Describe the \v
operation of surface condenser. t8]

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