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APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
FOURTH SEMESTER B.TECH DEGREE EXAMINATION, DECEMBER 2018
Course Code: ME204
Course name: THERMAL ENGINEERING

Max. Marks: 100 Duration: 3 Hours

Use of steam tables permitted
Part A

Answer any three questions

a) Draw the p-v and T-s diagram of a modified Rankine cycle. Clearly denote all the

processes involved. (4 marks)

b) Superheated steam (cp = 2.1 kJ/kg K) at a pressure of 10 bar and 400°C is supplied to a steam

engine. Adiabatic expansion takes place to release point at 0.9 bar and it exhausts into a
condenser at 0.3 bar. Neglecting clearance, determine: (i) Quality of steam at the end of
expansion and the end of constant volume operation. (ii) Modified Rankine cycle

efficiency. (6 marks)

Show the constructional details of a Locomotive boiler using a neat diagram. (10 marks)

a) Draw the combined velocity diagram for a moving blade of a single stage impulse steam

turbine. Clearly denote all the components. (4 marks)

b) Define the terms: (i) Degree of reaction. (ii) Stage efficiency. (iii) Reheat factor. (6 marks)

In an impulse steam turbine, steam issues from the nozzle with a velocity of 1200 m/s. The

nozzle angle is 20° and the mean blade velocity is 400 m/s. The inlet and outlet blade angles are

equal. The blade velocity coefficient is 0.8. The mass of steam flowing through the turbine per

hour is 950 kg. Calculate: (i) Blade angles. (ii) Relative velocity of steam entering the blades.

(iii) Tangential force on the blades. (iv) Power developed. (v) Blade efficiency.(10 marks) Part

B

Answer any three questions

5. The compression ratio for a dual cycle single cylinder engine with 3 working cycles per second,

is 9. The maximum pressure in the cycle is limited to 60 bar. The pressure and temperature of

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