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Seat No.: Enrolment
GUJARAT TECHNOLOGICAL UNIVERSITY
PD -SEMESTER 1 (NEW SYLLABUS) EXAMINATION- WINTER 2018
Subject Code: 2911902 Date: 09-01-2019
Subject Name: Engineering Thermodynamics
Time: 10:30 am to 01:00 pm Total Marks: 70
Instructions:
1. Attempt any five questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
Q.1

What do you mean by thermodynamic equilibrium? Explain in detail.
07

Derive steady flow energy equations for condenser and automobile radiator.
07
Q.2

State Clausius statement of second law of thermodynamics. Prove that violation of Clausius statement leads to violation of Kelvin Plank statement.
07

Derive equation for air standard efficiency of diesel cycle.
07
Q.3

Explain the concept of PMM I and PMM II.
07

10 kg of water at 270C is mixed with 2 kg of ice at 00C adiabatically. Calculate
Final temperature of mixture and
Initial and final entropy of system.
Assume Cpw 4.1868 kJ/kgK and latent heat of ice 335 kJ/kg
07
Q.4

Define irreversibility and explain causes of irreversibility.
07

In the piston cylinder arrangement, air expands from 8 bar and 1200C to 1.2 bar and 270C. Assume ambient temperature 250C and pressure 1 bar. Calculate maximum work per kg of air. Assume Cp 1 kJ/kgK, Cv 0.713 kJ/kgK.
07
Q.5

A thermal power plant is supplied with steam at 75 bar, 3500C and steam is discharged at pressure of 712.5 mm of Hg. Determine the thermal efficiency and turbine work for a steam flow rate of 3 kg/s.
07

Explain methods of improving efficiency of Rankine cycle.
07
Q.6

Explain simple VCR cycle with P-H and T-S diagrams.
07

Air standard brayton cycle in which air enters the compressor at 1 bar and 270C. The pressure of air leaving the compressor is 4 bar and temperature at turbine inlet is 7000C. Calculate per kg of air, efficiency of the cycle, heat supplied to air, work available at shaft and heat rejected in the cooler. For air γ 1.4 and Cp 1.005 kJ/kgK.
07
Q.7

Explain in brief:
Combustion equations of sulphur and methane for analysis by mass.
Limitations of reversed carnot cycle.
07

Write a short note on Bomb calorimeter.
07