Power Plant Engineering - Dec 2013

Mechanical Engg (Semester 8)

TOTAL MARKS: 100
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any four from the remaining questions.
(3) Assume data wherever required.
(4) Figures to the right indicate full marks.

Answer any one question from Q1 and Q2

1 (a) Discuss the methods of determining the depreciation of electric power plants.(9 marks) 1 (b) For a 200 MW thermal power plant, the following data is available
i) Fixed Cost = Rs. 24×10⁶ per year
ii) Cost of fuel = Rs. 1800 per ton
iii) Calorific value of fuel used = 20,000 kJ/kg
iv) Other expenses = Rs. 280 per kW per year
v) Plant heat rate
1) 18000 kJ/kWh at 100% capacity factor
2) 10500 kJ/kWh at 50% capacity factor
Determine the generating cost per k Wh at 100% and 50% capacity factor.(9 marks) 10 (a) Explain with neat sketch hydrogen-oxygen fuel cell.(8 marks) 10 (b) What is the difference between thermo-electric & thermionic conversion systems? Explain the working of thermionic system with neat sketch.(8 marks)

Answer any one question from Q11 and Q12

11 (a) What is acid rain? How they are controlled?(8 marks) 11 (b) What are the basic radioactive pollutants? What are their bad effect on human and vegetation life?(8 marks) 12 (a) What are the different methods used to control SO₂ in the flue gases? Explain any two.(8 marks) 12 (b) Classify different pollutant from thermal power plant. Explain how thermal pollution can be controlled.(8 marks) 2 (a) Discuss the performance of power plant considering input output curve, efficiency load curve, Define heat rate & incremental heat rate. Show that the heat rate of input out put is min. when it is equal to incremental rate.(9 marks) 2 (b) Discuss how unit energy cost is calculated.(9 marks)

Answer any one question from Q3 and Q4

3 (a) Explain the problem of dust collection on Indian scenario & discuss the working of Electrostatic precipitators. List their advantages & disadvantages.(8 marks) 3 (b) Give layout of unit system of pulverized fuel burning. List its advantages & disadvantages.(8 marks) 4 (a) Explain the working of reheat cycle with a schematic layout & h-s diagram. Derive the expression for efficiency of this cycle considering feed pump work.(8 marks) 4 (b) Explain Overfeed & Under Feed principles of coal firing.(8 marks)

Answer any one question from Q5 and Q6

5 (a) What do you understand by run off power plant? How they differ from other types of hydro power plants.(8 marks) 5 (b) What are the different types of spillways used in practice? Discuss the advantages of one over the other.(8 marks) 6 (a) An open cycle gas turbine plant uses heavy oil as fuel. The maximum pressure and temperature in the cycle are 5 bar and 650°C. The pressure and temperature of the air entering into the compressor are 1 bar and 27°C. The exit pressure of the turbine is 1 bar. Assuming isentropic efficiencies of the compressor and turbine to be 80% and 85% respectively. Find the thermal efficiency of the cycle. Overall air fuel ratio used is 60:1.
Take Cp (for air & gas)= 1 kJ/kg K
y for air and gas =1.4(8 marks) 6 (b) Explain with a neat sketch combined cycle power plant.(8 marks)

Answer any one question from Q7 and Q8

7 (a) Draw a neat diagram of CANDU type reactor & give its advantages & disadvantages over the other type of reactors.(9 marks) 7 (b) Explain with neat sketch gas cooled reactor.(9 marks)

Write short notes on:

8 (a) Nuclear power Plants in India.(6 marks) 8 (b) Nuclear waste disposal.(6 marks) 8 (c) Disadvantages of diesel power plant.(6 marks)

Answer any one question from Q9 and Q10

9 (a) What are the major electrical equipment used in power plants.(8 marks) 9 (b) What do you understand by MHD? Explain the working principle of MHD with neat sketch.(8 marks)