Sathyabama University 2008 B.Tech Chemical Engineering Thermodynamics - Question Paper
SATHYABAMA UNIVERSITY
(Established under section 3 of UGC Act, 1956)
Course & Branch: B. Tech Chemical (Part Time)
Title of the paper: Thermodynamics
Semester: I Max. Marks: 80
Sub.Code: 619PT104 (2007/2007 JAN/2008 JAN) Time: 3 Hours
Date: 22-05-2008 Session: FN
PART A (10 x 2 = 20)
Answer All the Questions
1. State the first law of thermodynamics.
2. Define the specific heat at constant volume and constant pressure.
3. Define COP of a refrigerator.
4. Draw a block diagram showing the four energy interactions of a cyclic heat engine.
5. What is a pure substance?
6. What is normal boiling point?
7. State the four process of diesel cycle.
8. How is the compression ratio of an SI engine fixed?
9. What is the condition for exact differential?
10. What is joule Thomson co-efficient? Why is it Zero for an ideal gas?
PART B (5 x 12 = 60)
Answer All the Questions
11. A stationary mass of gas is compressed without friction from an initial state of 0.3m3 and 0.105Mpa to a final state of 0.15m3 and 0.105Mpa, the pressure remaining constant during the process. There is a transfer of 37.6KJ of heat from the gas during the process. How much does the internal energy of the gas change?
(or)
12. Air flows steadily at the rate of 0.5kg/s through an air compressor, entering at 7m/s velocity, 100 Kpa pressure and 0.95 m3/kg volume and leaving at 5m/s, 700Kpa and 0.19m3/kg. The internal energy of the air leaving is 90KJ/kg greater than that of the air entering. Cooling water in the compressor jackets absorbs heat from the air at the rate 58KW. a) Compute the rate of shaft work input to the air in KW. b) Find the ratio of the inlet pipe diameter to outlet pipe diameter to outlet pipe diameter to outlet pipe diameter.
13. A cyclic heat engine operates between a source temperature of 800 degree C and a sink temperature of 30 degree C. What is the least rate of heat rejection per KW net output of the engine?
(or)
14. Which is the more effective way to increase the efficiency of a carnot engine to increase T1, keeping T2 constant or to decrease T2, keeping T1 constant?
15. A vessel of volume 0.04m3 contains a mixture of saturated water and saturated steam at a temperature of 250 degree C. The mass of the liquid present is 9kg. Find the pressure, the mass, the specific volume, the enthalpy, the entropy and the internal energy.
(or)
16. Steam initially at 1.5 Mpa, 300 degree C expands reversibly and adiabatically in a steam turbine to 40 degree C. Determine the ideal work output of the turbine per Kg of steam.
17. A diesel engine has a compression ratio of 14 and cut-off takes place at 6% of the stroke. Find the air standard efficiency.
(or)
18. A gas turbine plant operates on the Brayton cycle between Tmin = 300K and Tmax = 1073K. Find the maximum work done per Kg of air and the corresponding cycle efficiency. How does this efficiency compare with the carnot cycle efficiency operating between the same two temperatures.
19. If the boiling point of Benzene at 1 atm pressure is 353K, estimate the approximate value of the vapour pressure of benzene at 303K.
(or)
20. What is triple point? Explain
What are the latent heats of sublimation and Vapourization?(4)
What is the latent heat of fusion at the triple point? (3)
| Earning: Approval pending. |
