University Of Pune Question Paper
S.E. (Mechanical S/W) (Semester – I) Examination, 2011
THERMAL ENGINEERING – I
(2003 Course)
Time: 3 Hours Max. Marks: 100
Instructions : 1) Answer any three questions from each Section.
2) Answers to the two Sections should be written in separate
books.
3) Neat diagrams must be drawn wherever necessary.
4) Black figures to the right indicate full marks.
5) Use of logarithmic tables slide rule, Mollier charts, electronic
pocket calculator and steam tables is allowed.
6) Assume suitable data, if necessary.
SECTION – I
Unit – I
1. a) With neat sketch, explain orsat apparatus. 8
b) Obtain an expression for finding theoretical air required for complete
combustion of 1 Kg of solid fuel. 6
c) What do you mean by
i) Gravimetric analysis
ii) Volumetric analysis. 4
OR
2. a) Explain :
i) Flash point ii) Pour point
iii) Fire point. 6
b) Write a short note on -Alternative fuels for I.C. engine. 6
c) Explain -Bomb calorimeter with a neat sketch. 6
Unit –II
3. a) Explain how will you determine dryness fraction of steam with the help of
separting and throttling calorimeter ? 6
b) 1 kg of steam at initial condition of 6 bar and 0.2 dry is heated at constant
volume until the pressure is 20 bar. Determine final state of steam, heat
added, change of energy, change of entropy. 10
OR
4. a) Compare Carnot and Rankine cycle. 4
b) Define :
i) Work Ratio ii) Specific steam consumption. 4
c) Steam power plant operates on Rankine cycle. Turbine receives steam from
boiler at 30 bar and 250°C and is exhausted into a condenser at 0.5 bar.
Condensate is returned back to boiler by a feed pump.
Calculate :
i) Work done
ii) SSC
iii) Dryness fraction of steam entering the condenses
iv) Rankine cycle efficiency. 8
Unit – III
5. a) State the advantages of high pressure boilers. 5
b) Write a short note on - Boiler Draught. 5
c) Explain with a neat sketch, construction and working of superheater. 6
OR
6. a) With a neat sketch, explain feed check valve. 6
b) The following data refers to a boiler trial :
Duration of trial = 8 hrs
Pressure of steam = 14 bar
Dryness fraction = 0.973
Feed water evaporated = 26,700 kg
Temp. of water at inlet = 50°C
Coal used = 4260 kg
C.V. of coal = 28,900 kJ/kg
Air used = 17 kg/kg of coal
Temp. of flue gas = 344°C
Boiler room temp. = 21°C
Cp of flue gas = 1.1 kJ/kgk
Determine :
i) Boiler efficiency
ii) Equivalent of evaporation
iii) Heat lost to the flue gases in kJ/kg and in percentage. 10
SECTION – II
Unit – IV
7. a) Explain :
i) Heat engine ii) Heat pump. 4
b) State the limitations of first law of thermodynamics. 4
c) Explain the principle of increase in entropy. 4
d) Write a short note on -Clausius inequality. 4
OR
8. a) A heat pump is used to maintain an auditorium hall at 25°C, when the atm.
temp is 10°C. The heat leaks from the hall is 1500 kJ/min. Calculate the
pawer required to run the actual heat pump. If the cop of the actual heat
pump is 30% of the cop of carnot heat pump working between the same
temp. limits. 6
b) Explain :
i) Dead state
ii) Availability. 4
c) A temp of 2000°C is obtained in a furnace by burning fuel in air at atm
pressure and ambient temp of 27°C. The grass can be assumed to be perfect
gas with Cp = 1.0 kJ/kgk. Determine availability of heat in the products of
combination. 6
Unit – V
9. a) State the assumptions in the analysis of air standard cycle. 4
b) Compare Otto and Diesel cycle. 4
c) Derive an expression for air standard efficiency of diesel cycle. 8
OR
10. a) In an air standard diesel cycle, compression begins at 103 KPa and 300 k.
After compression heat addition of 545 kJ/kg of air, the peak pressure reached
is 4.7 MPa. Calculate :
i) Fuel cut-off ratio
ii) Compression ratio
iii) Max. temp in the cycle
iv) ASE
Assume Cp = 1.004 kJ/kgk. 8
b) Show that air standard efficiency of otto cycle depends upon the compression
ratio. 8
[3962] – 272 -4-
Unit – VI
11. a) Explain Battery ignition system. 6
b) How I.C. engines are classified ? 6
c) Write a short note on Morse test. 6
OR
12. a) Calculate bore and stroke of a 4 stroke petrol engine for the following data :
Compression ratio = 6
BP = 73.5 kW
Speed = 400 rpm
BMEP = 8.5 bar
Mechanical efficiency = 80%
BSFC = 0.346 kg/kW.h
C.V of fuel = 44100 kJ/kg
Assume, bore = stroke
Also calculate indicated and brake thermal efficiencies, air standard efficiency,
relative efficiency and IMEP. 12
b) Write a short note on- governing of I.C. engine. 6
——————
S.E. (Mechanical S/W) (Semester – I) Examination, 2011
THERMAL ENGINEERING – I
(2003 Course)
Time: 3 Hours Max. Marks: 100
Instructions : 1) Answer any three questions from each Section.
2) Answers to the two Sections should be written in separate
books.
3) Neat diagrams must be drawn wherever necessary.
4) Black figures to the right indicate full marks.
5) Use of logarithmic tables slide rule, Mollier charts, electronic
pocket calculator and steam tables is allowed.
6) Assume suitable data, if necessary.
SECTION – I
Unit – I
1. a) With neat sketch, explain orsat apparatus. 8
b) Obtain an expression for finding theoretical air required for complete
combustion of 1 Kg of solid fuel. 6
c) What do you mean by
i) Gravimetric analysis
ii) Volumetric analysis. 4
OR
2. a) Explain :
i) Flash point ii) Pour point
iii) Fire point. 6
b) Write a short note on -Alternative fuels for I.C. engine. 6
c) Explain -Bomb calorimeter with a neat sketch. 6
Unit –II
3. a) Explain how will you determine dryness fraction of steam with the help of
separting and throttling calorimeter ? 6
b) 1 kg of steam at initial condition of 6 bar and 0.2 dry is heated at constant
volume until the pressure is 20 bar. Determine final state of steam, heat
added, change of energy, change of entropy. 10
OR
4. a) Compare Carnot and Rankine cycle. 4
b) Define :
i) Work Ratio ii) Specific steam consumption. 4
c) Steam power plant operates on Rankine cycle. Turbine receives steam from
boiler at 30 bar and 250°C and is exhausted into a condenser at 0.5 bar.
Condensate is returned back to boiler by a feed pump.
Calculate :
i) Work done
ii) SSC
iii) Dryness fraction of steam entering the condenses
iv) Rankine cycle efficiency. 8
Unit – III
5. a) State the advantages of high pressure boilers. 5
b) Write a short note on - Boiler Draught. 5
c) Explain with a neat sketch, construction and working of superheater. 6
OR
6. a) With a neat sketch, explain feed check valve. 6
b) The following data refers to a boiler trial :
Duration of trial = 8 hrs
Pressure of steam = 14 bar
Dryness fraction = 0.973
Feed water evaporated = 26,700 kg
Temp. of water at inlet = 50°C
Coal used = 4260 kg
C.V. of coal = 28,900 kJ/kg
Air used = 17 kg/kg of coal
Temp. of flue gas = 344°C
Boiler room temp. = 21°C
Cp of flue gas = 1.1 kJ/kgk
Determine :
i) Boiler efficiency
ii) Equivalent of evaporation
iii) Heat lost to the flue gases in kJ/kg and in percentage. 10
SECTION – II
Unit – IV
7. a) Explain :
i) Heat engine ii) Heat pump. 4
b) State the limitations of first law of thermodynamics. 4
c) Explain the principle of increase in entropy. 4
d) Write a short note on -Clausius inequality. 4
OR
8. a) A heat pump is used to maintain an auditorium hall at 25°C, when the atm.
temp is 10°C. The heat leaks from the hall is 1500 kJ/min. Calculate the
pawer required to run the actual heat pump. If the cop of the actual heat
pump is 30% of the cop of carnot heat pump working between the same
temp. limits. 6
b) Explain :
i) Dead state
ii) Availability. 4
c) A temp of 2000°C is obtained in a furnace by burning fuel in air at atm
pressure and ambient temp of 27°C. The grass can be assumed to be perfect
gas with Cp = 1.0 kJ/kgk. Determine availability of heat in the products of
combination. 6
Unit – V
9. a) State the assumptions in the analysis of air standard cycle. 4
b) Compare Otto and Diesel cycle. 4
c) Derive an expression for air standard efficiency of diesel cycle. 8
OR
10. a) In an air standard diesel cycle, compression begins at 103 KPa and 300 k.
After compression heat addition of 545 kJ/kg of air, the peak pressure reached
is 4.7 MPa. Calculate :
i) Fuel cut-off ratio
ii) Compression ratio
iii) Max. temp in the cycle
iv) ASE
Assume Cp = 1.004 kJ/kgk. 8
b) Show that air standard efficiency of otto cycle depends upon the compression
ratio. 8
[3962] – 272 -4-
Unit – VI
11. a) Explain Battery ignition system. 6
b) How I.C. engines are classified ? 6
c) Write a short note on Morse test. 6
OR
12. a) Calculate bore and stroke of a 4 stroke petrol engine for the following data :
Compression ratio = 6
BP = 73.5 kW
Speed = 400 rpm
BMEP = 8.5 bar
Mechanical efficiency = 80%
BSFC = 0.346 kg/kW.h
C.V of fuel = 44100 kJ/kg
Assume, bore = stroke
Also calculate indicated and brake thermal efficiencies, air standard efficiency,
relative efficiency and IMEP. 12
b) Write a short note on- governing of I.C. engine. 6
——————
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