Engineering

Thermodynamics
(ME 22301-as per Autonomous R2022)

Compiled by
-Felix Mudiappan
Asst.Prof
Mechanical Department
St.Xavier’s Catholic College of Engineering,Chunkankadai
(Autonomous)

Unit-2

Prof

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 Unit-2(Question Bank-the 16 marks problems discussed in this notes)
Part-A
1. Define Clausius statement. 2 Re CO2
2. What is Perpetual motion machine of the second kind? 2 Re CO2
3. Define Kelvin Planck Statement. 2 Re CO2
4. Define the terms heat engine and heat pump. 2 Re CO2
5. Why the performance of refrigerator and heat pump are given in terms of C.O.P and not
2 Un CO2
in terms of efficiency?
6. What are the assumptions made on heat engine? 2 Re CO2
7. State Carnot theorem. 2 Re CO2
8. What is meant by entropy? 2 Re CO2
9. A Carnot heat engine receives 650 kJ of heat form a source of unknown temperature and
rejects 250 kJ of it to a sink as 297 K. Determine thermal efficiency of the heat engine.
2 Un CO2

10. Define the term source and sink. 2 Re CO2

11. What is reversed Carnot heat engine? What are the limitations of Carnot cycle? 2 Re CO2
12. State the corollaries of second law of thermodynamics. 2 Re CO2
13. Why Carnot cycle cannot be realized in practice? 2 Re CO2
14. Why a heat engine cannot have 100% efficiency? 2 Re CO2
15. State Clausius inequality. 2 Re CO2
16. Define the term COP 2 Re CO2
17. What are the assumptions made for describing the working of the Carnot engine? 2 Re CO2
18. A Carnot engine receiving heat at 400 K has an efficiency of 25 %. What is the C.O.P
of a Carnot refrigerator working between the same temperature limits? 2 Un CO2

19. Why the performance of refrigerator and heat pump are given in terms of C.O.P and not
in terms of efficiency? 2 Re CO2

20. What is reversed heat engine 2 Re CO2

Part-B
1. In a closed system air is at a pressure of 1 bar, temperature of 300 K and volume of
0.025 m3. The system executes the following process during the thermodynamic cycle.
1-2 constant volume heat addition till the pressure reaches 3,8 bar, 2-3 constant pressure 16 Un CO2
cooling of air, 3-1 isothermal heating to initial state. Determine the change in entropy in
each process.

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2. A Carnot engine operates between source temperature of 250°C & sink temperature of –
15°C. If the heat supplied is 80 kJ, find: (i) Efficiency of the system, (ii) The net work 16 Un CO2
transfer, (iii) Heat rejected to the sink
3. Air at a pressure of 1.032 bar & temperature of 30°C is present inside a cylinder of 0.255
volume & is confined by a frictionless weightless piston. The air is heated at constant
16 Un CO2
pressure to a temperature of 300°C. Calculate the final volume, work transfer, heat
transfer, change in enthalpy & change in entropy.
4. A reciprocating compressor containing air is pressurized isothermally from a pressure of
1 bar & 300 K to 10 bar. Calculate the final volume, work transfer, heat transfer and 16 Ap CO2
change in internal energy, enthalpy & entropy.
5. A closed vessel of volume 0.02 m3 contains air at 1 bar & 290 K. The air first undergoes
a constant volume heat addition process till the pressure rises to 3 bar. It then undergoes
a constant pressure cooling process & finally undergoes an isothermal heating process to 16 Ap CO2
reach the initial state thus forming a cycle. Represent the cycle in P-V & T–S plots & find
out the entropy change of each process.
6. A heat pump working on the Carnot cycle takes in heat from a reservoir at 5 oC and
delivers heat to a reservoir at 60oC. A heat engine is driven by a source at 840oC & rejects
heat to a reservoir at 60°C. The heat engine in addition to driving the heat pump, also
drives the machine that absorbs 30 kW. If the heat pump extracts 17 kJ/s of heat from the 16 Ap CO2
reservoir at 5oC. Determine (i) The rate of heat supply from the source at 840°C, (ii) The
rate of rejection of the heat to the sink at 60°C.

7. An inventor claims to have developed an engine that takes in 105 MJ at a temperature of

400 K, rejects 42 MJ at a temperature of 200 K and delivers 15 kWh of mechanical work.
16 Ap CO2
Would you advise investing money to put this engine in market?

8. An ice plant working a reversed Carnot cycle heat pump produces 15 tons of ice per day.
The ice is formed from water at 0oC and the formed ice is maintained at 0oC. The heat is
rejected to the atmosphere at 25oC. The heat pump used to run the ice plant is coupled to
a Carnot engine which absorbs heat from a source which is maintained at 220oC by 16 Ap CO2
burning liquid fuel of 44,500 kJ/kg calorific value and rejects the heat to the atmosphere.
Determine (i) power developed by the engine, (ii) fuel consumed per hour.
Take enthalpy of fusion of ice as 334.5 kJ/kg.
9. A reversible heat engine operating between reservoirs at 900 K and 300 K drives a
reversible refrigerator operating between reservoirs at 300 K and 250 K. The heat engine
receives 1800 kJ heat from 900 K reservoir. The net output from the combined engine 16 Ap CO2
refrigerator is 360 kJ. Find the heat transferred to the refrigerator and the net heat rejected
to the reservoir at 300 K.

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10. Two reversible heat engines A and B are arranged in series. A rejecting heat directly to
B. Engine receives 200 kJ at a temperature of 421oC from a hot source while engine B is
in communication with a cold sink at a temperature of 4.4oC if the work output of A is 16 Ap CO2
twice that of B. Find (i) the intermediate temperature between A and B, (ii) the efficiency
of each engine and (iii) the heat rejected to the cold sink.

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References
Text Books Prescribed by the College (T):

T1. Nag.P.K., “Engineering Thermodynamics”, 6th Edition, Tata McGraw Hill (2017), New
Delhi.
T2. Cengel, Y and M. Boles, Thermodynamics - An Engineering Approach, Tata McGraw Hill,8th
Edition, 2015

Reference Books Prescribed by the College (R):

R1. Natarajan, E., “Engineering Thermodynamics: Fundamentals and Applications”, 2nd Edition
(2014), Anuragam Publications, Chennai Borgnakke & Sonnatag, “Fundamental of
Thermodynamics”, 8th Edition, 2016.
R2. Chattopadhyay, P, "Engineering Thermodynamics", Oxford University Press, 2016.

R3. Rathakrishnan, E., “Fundamentals of Engineering Thermodynamics”, 2nd Edition, Prentice

Hall of India Pvt. Ltd, 2006.

R4. Claus Borgnakke and Richard E. Sonntag, “Fundamentals of Thermodynamics”, 7th Edition,
Wiley Eastern, 2009.

R5. Venkatesh. A, “Basic Engineering Thermodynamics”, Universities Press (India) Limited,

2007.

Additional Text Books (AT):

AT1. Rayner Joel, “Basic Engineering Thermodynamics” 5th Edition, Pearson India Education
Services Pvt. Ltd., 2008
AT2. Natarajan E., "Engineering Thermodynamics: Fundamentals and Applications", Anuragam
Publications, 2012.

AT3. R. K. Rajput, “A Text Book of Engineering Thermodynamics, “Fifth Edition, 2017.

Additional References
AR1. Holman.J.P., "Thermodynamics", 3rd Edition, McGraw-Hill, 1995.
AR2. Rathakrishnan. E., "Fundamentals of Engineering Thermodynamics", 2nd Edition,
prentice- Hall of India Pvt. Ltd, 2006

Journals/Magazines (J):
J1. Journal of Thermodynamics, Hindawi publications.

Web References (W):

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W1.https://onlinecourses.nptel.ac.in/noc18_ch03/preview
W2. https://www.livescience.com/50776-thermodynamics.html
W3. https://www.edx.org/course/thermodynamics-iitbombayx-me209-1x-1

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