Name of the College : Sphoorthy Engineering College
University : JNTUH
Department : AUTOMOBILE ENGINEERING
Subject Code/Name : 09A50306/APPLIED THERMODYNAMICS – II
Degree : B.Tech
Year/Sem : III/I
Website : sphoorthyengg.com
Document Type : Model Question Paper
Download Model/Sample Question Paper : https://www.pdfquestion.in/uploads/sphoorthyengg.com/4844-09A50306%20-%20APPLIED%20THERMODYNAMICS%20-%20II.pdf
Applied Thermodynamics-II Question Paper :
B. Tech III Year I Semester Examinations, December-2011
(MECHANICAL ENGINEERING, AUTOMOBILE ENGINEERING)
Time: 3 hours
Related : Sphoorthy Engineering College 09A52401 Mechanics of Fluids & Hydraulic Machines B.Tech Question Paper : www.pdfquestion.in/4786.html
Max. Marks: 75
Answer any five questions :
All questions carry equal marks :
Use of Steam Tables is permissible
1. In a steam power plant operating on an ideal Rankine cycle, the steam enters the turbine at 3 MPa and 4000C and is exhausted at 10 kPa. Assuming all ideal processes, determine the following:
a) Thermal efficiency of the cycle and condition of steam at the exit of turbine
b) Thermal efficiency if steam is supplied at 3 MPa and 5000C and condition of steam at he exit of turbine. Estimate the increase or decrease of thermal efficiency due to super heating and comment on the result of thermal efficiency and steam exit condition from turbine comparing the two cases. [15]
2. The following readings were recorded during a 2 hour boiler trial on a boiler:
Feed water supplied : 14000 kg
Boiler working pressure : 10 bar
Dryness fraction of the steam : 0.96
Temperature of feed water entering Economizer : 350C
Temperature of feed water leaving Economizer : 900C
Temperature of steam leaving super heater : 2500C
Coal burnt : 1500 kg
Calorific value of the coal : 33500 kJ/kg
Conduct Boiler Trial based on the data. Also evaluate the overall efficiency of the boiler. Also evaluate the equivalent evaporation from and at 1000C. [15]
3.a) Give the physical explanation of Critical pressure ratio of Convergent nozzle.
b) In a convergent – divergent nozzle, the steam enters at 15 bar and 3000C 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 a mass flow rate of 1 kg/s. Assume the nozzle efficiency to be 90%. [7+8]
4. Steam issues from a nozzle of a simple impulse turbine with a velocity of 610 m/s. The nozzle angle is 200 and the diameter of the rotor is 62 cm and runs at 9500 RPM. The blade outlet angle is 300 and the friction factor is 0.8. Calculate the power developed for kg of steam and diagram efficiency by drawing velocity triangles. [15]
5.a) Compare the impulse and reaction turbines.
b) Show that for a Parson’s reaction turbine, the fixed and moving blades are of same shape. [7+8]
6.a) Give the comparison between jet and surface condensers.
b) A surface condenser of 0.75 m3 capacity contains saturated steam and air at a temperature of 450C and an absolute pressure of 0.13 bar.
Air leaks further into condenser and the hence the absolute pressure of the condenser is increased to 0.28 bar and the temperature falls to 380C. Calculate the mass of air leaked into the condenser. [7+8]
7. In a reheat regenerative gas turbine plant, the pressure ratio of the compressor is 4:1. The temperature of the gases entering the HP turbine and LP turbine are 6600C and 6250C respectively.
Condition of air entering the compressor is 1 bar and 170C. The effectiveness of the regenerative heat exchanger is 0.75. Calculate the pressure of gases entering the LP turbine and the overall plant efficiency. [15]
8.a) Differentiate between air breathing engines and rockets.
b) With the help of a neat diagram, explain the function of a pulse jet engine along with its applications. [7+8]
B. Tech III Year I Semester Examinations, December-2011 Set II :
1. In a steam power plant operating on an ideal Rankine cycle, the steam enters the turbine at 3 MPa and 4000C and is exhausted at 10 kPa. Assuming all ideal processes, determine the following:
a) Thermal efficiency of the cycle and condition of steam at the exit of turbine
b) Thermal efficiency if steam is supplied at 10 MPa and 4000C and condition of steam at the exit of turbine. Estimate the increase or decrease of thermal efficiency due to increase of boiler pressure and comment on the result of thermal efficiency and steam exit condition from turbine comparing the two cases. [15]
2. Calculate the motor power required to drive a fan which maintains a draught of 45 mm of water under the following conditions: a) Induced draught and b) Forced draught. The temperature of the flue gases leaving the boiler in each case is 2000C and the boiler house temperature is 330C.
The air supplied is 18.5 kg per kg of the fuel. The mass of coal burnt per hour is 1820 kg. Assume a fan efficiency of 80% in both the cases. Comment on the result. [15]