MODEL QUESTION
PAPER (CIE)
Test/Date
and Time |
Semester/year |
Course/Course Code |
Max Marks |
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Ex:
I test/6 ^{th} week of sem 10-11 Am |
VSEM |
APPILED THERMAL ENGG. |
20 |
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Year: 2016-17 |
Course
code:15ME52T |
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Name
of Course coordinator : Units:1,2 Co:
1,2 Note:
Answer all questions |
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Question no |
Question |
MARKS |
CL |
CO |
PO |
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1 |
Explain
Barrel type Steam Calorimeters with a neat sketch. OR Explain Separating type Steam Calorimeters with a
neat sketch |
5 |
U |
2 |
2 |
|||
2 |
Make use of the given data
find the quantity of heat required to produce 1kg of steam at a pressure of 6
bar at a temperature of 25^{0}C, under the following conditions. a) When the steam is wet
having a dryness fraction 0.9, b) when the steam is dry
saturated, c)when it is superheated at a constant pressure at 250^{0}C
assuming the mean specific heat of superheated steam to be 2.3 kJ/kg^{0}K. |
5 |
A |
1 |
2 |
|||
3 |
Choose the
different system of producing draught in a boiler and mention their advantages and disadvantages |
5 |
A |
2 |
2 |
|||
4 |
Explain the various types of draughts used in usual practice. OR Compare the advantages of
high pressure boiler over low pressure boiler. |
5 |
U |
2 |
2 |
|||
MODEL QUESTION PAPER (SEE)
V- Semester Diploma
Examination
Course Title: APPLIED THERMAL ENGINEERING
Time: 3 Hours] [Max Marks: 100
Note: Answer any SIX from PartA and any SEVEN from Part B
PART-A 6x5=30 marks
1. List the advantages of
superheated steam
2. Explain Barrel type Steam
Calorimeters with a neat sketch
3.
List the various types of draughts used in usual practice.
4.
List the different types of steam -
condensers.
5.
List the function of cooling tower in a modem condensing plant
6.
Explain the Working of simple De-Laval turbine with line diagram
7.
Summarise the advantages and disadvantages of velocity compounded
impulse turbines.
8. List the desirable
properties of a secondary refrigerant.
9.
Explain Single stage reciprocating air compressor with line diagram
PART-B 7x10=70 marks
1.
Steam at 18 bar and dryness 0.9 is heated at constant pressure until
dry and saturated. Find the increase in volume, heat supplied and work done per
kg of steam. If the volume is now
kept constant, find how much heat must be extracted to reduce the pressure to 14 bar.
2.
Make use of the steam table,find the following : (i) Enthalpy and
volume of 1 kg of steam at 12. 1 bar and dryness fraction 0.9, and (ii)
Enthalpy and volume of 1 kg of steam at 12. 1 bar and 225’C. Take the specific
heat at constant pressure for superheated steam as 2.1 kJ/kg K.
3.
i) Compare high pressure boiler and low pressure boiler
ii) Explain
the function of the safety valve
4.
Outline the sketch and explain the working of a La-mount boiler
5.
Outline the sketch and explain counter-flow low level jet condenser and
list the advantages.
6.
A convergent-divergent nozzle is required to discharge 2 kg of steam
per second. The nozzle is supplied with steam at 7 bar and 180^{0}C and
discharge takes place against the back pressure of 1 bar. The expansion up to
throat is isentropic and the frictional resistance between throat and exit is
equivalent to 63 kJ/kg of steam. The approach velocity to the nozzle is 75 m/s
and throat pressure is 4 bar. Estimate (a) Suitable areas of throat and exit,
(b) Overall efficiency of the nozzle based on enthalpy drop between inlet pressure,
temperature and exit pressure.
7.
An impulse turbine with a single row wheel is to
develop 99.3 kW, the blade speed being 150 m/sec. A mass of 2 kg of steam per
second is to flow from the nozzles at a speed of 350 m/sec. The velocity
coefficient of the blades may be assumed to be 0.8 while the steam is to flow axially after passing through the blades ring. Determine
the
nozzle angle, and
the blade angles at inlet and exit assuming no shock. Estimate also the diagram
efficiency of the blading.
8.
The steam leaves the nozzle of a single-stage impulse
wheel turbine at 900 m/sec. The nozzle angle is 20°, the blade angles are 30°
at inlet and outlet, and friction factor is 0.8.
Calculate : (a) the blade velocity, and (b) the steam flow in kg per
hour if the power developed by the turbine is 257'kW.
9.
a) Explain winter Air Conditioning with neat sketch.
b) Explain Summer
Air conditioning with neat sketch
10.
It is desired to compress 17m^{3} of air per minute from 1 bar
(100 kN/m2) and 21'C to a delivery pressure of 7 bar (700 kN/m^{2}) in
a single-stage, single-acting air compressor. Calculate the power required to
drive the compressor and the heat rejected duhng compression to cooling water if the compression is (a) Isentropic
(y = 1.4 for air), and
(b) Isothermal.
MODEL QUESTION
BANK
Diploma in
Mechanical Engineering V Semester
Course title:
APPILED THERMAL ENGINEERING
Note: The paper setter is of liberty to set the questions on his/her
desecration based on cognitive levels notified for that unit. They has to
follow only blue print of SEE question paper format. The model question bank is
only for reference to students/course coordinator to initiate the process of
teaching-learning only.
CO-1: Determine steam
properties and dryness
fractions.
REMEMBER
1.
What is meant by saturation temperature and saturation pressure?
2. Define the following terms : (i) Saturated steam, (ii) Dry saturated
steam, (Hi) Wet steam, (iv) superheated steam, (v) Dryness fraction of steam,
(vi) Specific volume of steam, and (vii) Saturated water.
3.
List the advantages of superheated steam
4.
Define Internal energy of steam.
UNDERSTAND
1.
Explain the process of formation of steam at a constant pressure from water.
2. Explain how the wet steam,
dry saturated steam and superheated steam is
produced.
3. Explain T-H diagram during
steam formation.
4. Explain steam tables and
their uses.
5. Explain Carnot cycle with Sketch
6. Explain with sketch Rankine cycle
7. Explain Barrel type Steam
Calorimeters with a neat sketch.
8. Explain Separating type
Steam Calorimeters with a neat sketch
9. Explain Throttling type
Steam Calorimeters with a neat sketch
10.
Explain combined Separating
& Throttling type Steam Calorimeters with a neat sketch
11. Compare enthalpy and
internal energy of steam
12. Outline the Limitations of Calorimeter.
13. Explain the following terms : (i) Saturated steam, (ii) Dry saturated
steam, (Hi) Wet steam, (iv) superheated steam, (v) Dryness fraction of steam,
(vi) Specific volume of steam, and (vii) Saturated water.
14. Explain the following terms as referred to steam : (i) Enthalpy of
water, (ii) Enthalpy of evaporation, (iii) Superheat, (iv) Specific volume, and
(v) Enthalpy of dry saturated steam.
15. Compare saturated steam and dry saturated steam.
APPLICATION
1.
Make use of the given data find the quantity of heat required to
produce 1kg of steam at a pressure of 6 bar at a temperature of 25^{0}C, under the following conditions.
a) When the steam is wet having
a dryness fraction 0.9, b)when the steam is dry saturated, c)when it is
superheated at a constant pressure at 250^{0}C
assuming the mean specific heat of superheated steam to be 2.3 kJ/kg^{0}K.
2.
Steam enters an engine at a pressure of 12bar with 67^{0}C of
superheat. It is exhausted at a pressure of 0.15bar and 0.95dry. Find the
drop in enthalpy of steam.
3.
Make use of the given data find the internal energy of 1kg of
superheated steam at a pressure of 10bar and
280^{0}C.
If this steam
be expanded to a pressure of 1.6bar and 0.8dry, determine the change in
internal energy. Assume specific heat of superheated steam as 2.3 kJ/kg^{0}K.
4.
A vessel contains 20kg of steam at a pressure of 8 bar. Find the amount
of heat, which must be rejected, so as to reduce the quality of steam in the
vessel to be 70%.
5.
Steam at 18 bar and dryness 0.9 is heated at constant pressure until
dry and saturated. Find the increase in volume, heat supplied and work done per
kg of steam. If the volume is now kept constant, Analyze how much heat must be
extracted to reduce the pressure to 14 bar.
6.
Analyze how much heat is needed to convert 5 kg of water at 40'C into
90 per cent dry (or 10 per cent wet) steam at 5 bar (500 kPa) ? Take specific
heat of water as 4. 187 kJ/kg K.
7.
Analyze how much heat is needed to convert 4 kg of water at 20’C into
steam at 8 bar (800 kPa) and 200'C. Take kp of superheated steam as 2.1 kJ/kg K and specific heat of water as
4.187 kJ/kg K.
8.
Make use of the given data ,Find the volume of one kilogram of steam at
a pressure of 15 bar (15 MPa) in each of the following cases : (i) when steam
is dry saturated, (ii) when steam is wet having dryness fraction of 0.9, and (iii)
when steam is superheated, the degree of superheat being 40'C.
9.
Analyze the condition of steam in each of the following cases : (i) at
a pressure of 10 bar and temperature
200‘C, (ii) at a pressure of 8 bar and volume 0.22 m /kg, and (iii) at a pressure of 12 bar, if 2,688 kJ/kg are
required to produce it from water at 0 ‘C.
10.
Utilize steam table,and find (i) Enthalpy and volume of 1 kg of steam
at 12. 1 bar and dryness fraction 0.9, and (ii) Enthalpy and volume of 1 kg of
steam at 12. 1 bar and 225’C. Take the specific heat at constant pressure for
superheated steam as 2.1 kJ/kg K.
11.
Wet steam of mass 25 kg and occupying a volume of 0.49 m at 75 bar has
a total heat (enthalpy) increase of 1,500 kJ when superheated at constant
pressure. Determine : (i) Initial quality of steam, (ii) Final quality (degree
of superheat) of steam, and (HI) Increase in volume of steam after
superheating. Assume kp for the superheated steam to be 2-1 kJ/kg K.
12.
Steam enters a steam engine at a pressure of 12 bar with 67‘C of
superheat and is exhausted at 0.15 bar and 094 dry. Calculate the drop in enthalpy
from admission to exhaust, and volume of 1 kg of steam at admission and exhaust
conditions. Take kp of superheated steam as 2.1 kJ/kg K.
13.
Make use of the given data, find the external work done during
evaporation, internal latent enthalpy and internal energy per kg of steam at a
pressure of 15 bar (1,500 kPa) when the steam is (i) 09 dry, and (ii) dcy saturated.
14.0.025 m3 of steam at 3.5 bar and dryness fraction 08 is converted
into dry saturated steam at 11 bar. By how much are the enthalpy and internal
energy changed ?
15. The internal energy of 1 kg
of steam at a pressure of 14 bar (1.4 MPa)
is 2,420 kJ. Calculate the dryness fraction of this steam. Find the increase in
internal energy if this steam is superheated at constant pressure to a
temperature of 295'C. Take kp of superheated steam as 2.3 kJ/kg K.
16. Inspect at what fraction of
enthalpy of 1 kg of steam at 10 bar and 0.9 dry
represents the internal energy ? What is the change in internal energy when the
pressure and temperature of this steam is raised to 13 bar and 250'C ? Take kp
of superheated steam as 2.1 kJ/kg K.
CO-2: Classify and explain boilers, boiler mountings and
accessories
REMEMBERING
1. Define steam boiler and list
its function.
2. List the types of boilers
according to various factors
3. List the advantages of a
Lancashire boiler
4. List the advantages of
Cochran boilers
5. List the advantages and
disadvantages of a locomotive boiler.
6. List the advantages and
disadvantages of water-tube boilers.
7. List the advantages of
water-tube boilers over fire-tube boilers and tank boilers.
8. List the boiler mountings.
9.
List the different mountings
and accessories with which the Babcock and Wilcox water-tube boiler is fitted
10. List the various types of
draughts used in usual practice.
UNDERSTANDING
1.
Explain the following terms used in boiler practice : (a) Boiler shell,
(b) Fire grate,
(c) Furnace, (f) Mountings, (g) Blowing-off
2. Expline the method of
obtaining draught in the boiler.
3. Compare ‘water-tube’ and
Fire-tube' boilers.
4.
Explain the function of the safety valve .
5.
Explain the function of the Fusible
plug.
6. Outline the neat sketch of
the Babcock and Wilcox water tube boiler.
7.
Compare Natural draught and artificial
draught.
8.
Compare Forced draught and induced draught.
9.
Compare how an artificial
draught is considered advantageous over a natural draught
10. Explain the terms mechanical
draught and balanced draught.
11. Explain the working
principle of the steam jet draught.
12. Compare the advantages of
high pressure boiler over low pressure boiler.
13. Compare high pressure boiler
and low pressure boiler.
APPLICATION
1.
Construct neat sketch and explain the Lancashire boiler.
2. Construct neat sketch and
explain the Co-chran boiler
3. Construct neat sketch and
explain the locomotive boiler.
4.
Choose the different system
of producing draught in a boiler and mention their advantages and
disadvantages.
5. Construct neat sketch and
explain the La-mount boiler.
6. Construct neat sketch and
explain the working of a Benson boiler
REMEMBERING
1.
List the function of a condenser in a modem steam condensing power plant.
2.
list the different types of steam - condensers.
3.
List the function of cooling tower in a modem condensing plant.
4.
Define the term ‘Nozzle efficiency.
UNDERSTANDING
1. Outline the Sketch and
explain the working of Surface Condenser
2. Outline the Sketch and
explain the working of Jet Condenser
3. Construct neat sketch of a
barometric jet condenser and explain its working
4. Compare the merits and demerits
of surface condensers over jet condensers
5. Construct neat sketch of a
counter-flow low level jet condenser and explain its working.
6. Construct neat sketch and
explain the operation of an evaporative condenser
7. Construct neat sketch and
explain the working of any one type of cooling
tower.
8. Explain the function of a
steam nozzle. Explain the types of nozzles with sketch.
9. Explain the term critical
pressure as applied to steam nozzles.
10.
Explain the term “critical pressure" as applied to steam nozzles.
Why are the turbine nozzles made divergent after the throat.
11. Explain he causes of
supersaturated flow in nozzles.
12.
Explain the supersaturated expansion of steam and give some idea of the
limits within which this condition is possible.
13. Explain the Types of steam
nozzles with neat sketches
14.
Explain the Effect of
friction on the flow of steam through convergent-divergent steam nozzles.
15. Explain the Effect of
supersaturated flow in steam nozzles.
APPLICATION
1.
A nozzle is to be designed to expand steam at the rate of 0.10kg/s from
500kpa, 210^{0}C to 100kpa. Neglect inlet velocity of steam. For a
nozzle efficiency of 0.9, determine the exit area of the nozzle.
2.
Steam enters a convergent – divergent nozzle at 2 MPa and 400^{0}C
with a negligible velocity and mass flow rate of 2.5 kg/s and it exists at a
pressure of 300 kPa. The flow is isentropic between the nozzle entrance and
throat and overall nozzle efficiency is 93 percent. Determine (a) throat, and
(b) exit areas.
3.
In a convergent-divergent nozzle, the steam enters at 15 bar and 300^{0}C
and leaves at a pressure of 2 bar. The inlet velocity to the nozzle is 150 m/s.
Find the required throat and exit areas for mass-flow rate of 1 kg/s. Assume
nozzle efficiency to be 90 percent and Cps= 2.4 kJ/kgK
4.
Determine the throat and exit diameters of a convergent-divergent
nozzle, which will discharge 820 kg of steam per hour at a pressure of 8 bar
superheated to 220 ^{0}C into a chamber having a pressure of 1.5 bar.
The friction loss in the divergent portion of the nozzle may be taken as 0.15 of
the isentropic enthalpy drop.
5.
A convergent-divergent nozzle is required to discharge 2 kg of steam
per second. The nozzle is supplied with steam at 7 bar and 180^{0}C and
discharge takes place against the back pressure of 1 bar. The expansion up to
throat is isentropic and the frictional
resistance
between throat and exit is equivalent to 63 kJ/kg of steam. The approach
velocity to the nozzle is 75 m/s and throat pressure is 4 bar. Estimate (a)
Suitable areas of throat and exit, (b) Overall efficiency of the nozzle based
on enthalpy drop between inlet pressure, temperature and exit pressure.
6.
A turbine having a set of 16 nozzles receives steam at 20 bar and 400 ^{0}C. The pressure of steam at
the nozzle exit is 12 bar. If the
discharge rate is 260 kg/min and the nozzle efficiency is 90 %, calculate the cross-sectional area at the nozzle exit. If the steam has a velocity of 80 m/s at
entry to the nozzle, find the percentage increase in discharge.
7.
The steam is supplied to a nozzle at a rate of 1 kg/s from an inlet condition
of 10 bar, dry saturated and exit at 1 bar pressure. The efficiency of the
nozzle for the convergent portion is 95 percent and that of the divergent
portion is 90 percent. Determine (a) throat and exit diameters of nozzle (b)
length of nozzle, if divergent cone angle of the nozzle is 14^{0}. (c)
The power in kW correspondence to exit velocity of the steam
8.
A convergent-divergent nozzle is required to discharge 350 kg of steam
per hour. The nozzle is supplied with steam at 8.5 bar and 90% dry and discharges
against a back pressure of 0.4 bar. Neglecting the effect of friction, find the
throat and exit diameters.
CO-4: Understand the working of steam Turbines
1. Compare Impulse and reaction
turbines.
2. Explain the principle of working
of impulse turbine.
3. Explain the Working of
simple De-Laval turbine with line diagram
4. Outline the velocity diagram
of a impulse turbine blades.
5. Explain the need for
compounding.
6.
Explain Blade efficiency and diagram efficiency.
7.
Explain why steam turbines are compounded
8. Explain the Pressure
compounding with diagrams
9. Explain the Velocity compounding
with diagrams
10. Explain the
Pressure-Velocity compounding with diagrams.
11. Explain the working of an
Impulse reaction turbine.
12. Summarise the advantages and disadvantages of velocity compounded
impulse turbines.
13. Explain Parson’s reaction turbine.
APPLICATION
1.
Steam issues from the nozzle of a simple impulse
turbine with a velocity of 900 m/sec. The nozzle angle is 20°, the mean
diameter of the blades is 25 cm and the speed of rotation is 20,000 r.p.m.
m The mass flow through
the turbine nozzles
and blading is
0.18 kg of steam per sec. Draw the velocity diagram and derive or
calculate the following : (a) Tangential force on blades, (b) Axial force on
blades, (c) Power developed by the turbine wheel, (d) Efficiency of the
blading, and (e) Inlet angles of
2.
The rotor of an impulse turbine is 60 cm diameter and
runs at 9,600 r.p.m. The nozzles are
at 20° to the plane, of the wheel, and the steam leaves them at 600 m/sec. The
blades outlet angle are 30° and the friction factor is 0.8. Calculate the power
developed per kg of steam per second and the diagram efficiency.
3.
An impulse turbine with a single row wheel is to
develop 99.3 kW, the blade speed being 150 m/sec. A mass of 2 kg of steam per
second is to flow from the nozzles at a speed of 350 m/sec. The velocity
coefficient of the blades may be assumed to be 0.8 while the steam is
to flow axially after passing through the blades ring. Determine the nozzle
angle, and the blade angles at inlet and exit assuming no shock. Estimate also
the diagram efficiency of the blading.
4.
The steam leaves the nozzle of a single-stage impulse
wheel turbine at 900 m/sec. The nozzle angle is 20°, the blade angles are 30°
at inlet and outlet, and friction factor is 0.8.
Calculate : (a) the blade velocity, and (b) the steam flow in kg per
hour if the power developed by the turbine is 257'kW.
5.
The outlet area of the nozzles in a simple impulse
turbine is 15-5 err? and the steam leaves them 0.91 dry at 1.4 bar and at 920
m/sec. The blade angles are 30° at inlet and exit, and the blade velocity is
0.25 of the steam velocity at the exit from the nozzle. The friction factor is
0.8. Find : (a) the nozzle angle, (b) the power developed, (c) the diagram
efficiency, and (d) the axial thrust on the blading.
6.
A single stage impulse rotor has a blade ring diameter
of 57.5 cm and rotates at a speed of 10,000 r.p.m. The nozzles are inclined at
20^{0} to the direction of motion of the blades and the velocity of the
issuing steam is 1050 m/sec. Determine the inlet blade angle in order that the
steam shall enter the blades passage without shock. Assume a friction coefficient
of the blading equal to 0.85 and that the inlet and outlet angles are equal.
Find also: (a) the power developed at the blades for a steam supply of 1,350 kg
per hour, (b) the diagram efficiency, and (c) the loss of kinetic energy due to
blade friction.
CO5: Operate air compressors and observe the parameters affecting the performance
REMEMBERING
1. List the types of air compressors.
2. List the applications of the
air compressor.
3.
List the advantages of multi stage reciprocating air compressor.
UNDERSTANDING
1.
Explain the uses of compressed air.
2. Classify the air compressor.
3. Explain Single stage reciprocating
air compressor with line diagram.
4. Explain multi stage
compression with line diagram.
5. Compare Reciprocating
compressor with Rotary compressors.
6. Explain with Sketch the
operation of a single-stage centrifugal compressor
7. Explain with Sketch the
operation of a Screw compressor(oil free).
APPLICATION
1.
A single-cylinder, single-acting reciprocating air compressor has a
cylinder of 24 cm diameter and linear piston speed of 100 metres per minute. It
takes in air at 100 kPa (100 kN/m2) and delivers at 1 MPa ( 1 MN/rrP), Determine
the indicated power of the
compressor.
Assume the law of compression to be pv^{1.25} = constant ture of air at
inlet is 288 K. Neglect clearance effect.
2.
A single-acting, single-stage air compressor developing indicated power
of 11 kW, runs at 200 r.p.m. and has a linear piston speed of 100 metres per
min. If the suction pressure and temperature are 100 kPa and 15‘C respectively
and delivery pressure is 1,000 kPa, calculate the dimensions of the compressor
cylinder. Assume the law of compression to be pv^{1.25} = constant.
Neglect clearance effects.
3.
A single-acting, single-stage air compressor is belt driven from an electric motor at 300
r.p.m. The
cylinder diameter is 20 cm and the stroke is 24 cm. The air is compressed from
one atmosphere to 8 atmospheres and the law of compression is pv^{1.25}
= constant. Find the power of the electric motor if the transmission efficiency
is 96 per cent and the mechanical efficiency of the compressor is 85 per cent
Neglect clearance effect.
4.
It is desired to compress 17m^{3} of air per minute from 1 bar
(100 kN/m2) and 21'C to a delivery pressure of 7 bar (700 kN/m^{2}) in
a single-stage, single-acting air compressor. Calculate the power required to
drive the compressor and the heat rejected during compression to cooling water if the compression is (a) Isentropic
(y = 1.4 for air), and
(b)
Isothermal.
CO6: Know the mechanism of refrigeration, and its types
and different air conditioning system
REMEMBER
1. Define Refrigeration,
Refrigerating effect, Tonne of refrigeration and COP.
2. Name the common refrigerants
in use.
3. List the desirable
properties of a secondary refrigerant.
4. Define Air Conditioning and
list the types of air conditioning.
5.
Define Dry air, Saturated air, Dry bulb temperature,
Wet bulb temperature, Dew point temperature, Relative humidity, Absolute
humidity, Specific humidity.
UNDERSTANDING
1.
Explain Vapour compression refrigeration with flow diagram.
2.
Explain Vapour absorption refrigeration with flow diagram.
3.
Explain the factors
affecting the choice of refrigerants commonly used in refrigerating machines.
4.
Explain winter Air Conditioning with neat sketch.
5.
Explain Summer Air conditioning with neat sketch.
6.
Explain Year round air conditioning with neat sketch.