Sardar Vallabhbhai National Institute of Technology 2012 B.Tech Electrical Engineering Applied Thermodynamics and Thermal Engineering_ - Question Paper
Special course at Electrical engg.
SARDAR VALLABHBHAI NATIONAL INSTITUTE OF TECHNOLOGY, SURAT
Mechanical engineering department End Semester Examination May - 2012 B. Tech. -II (Electrical)
Sub: ATTE
Time: 2 Hrs. Marks: 50
Instructions:
(1) Attempt any two from Q. 1, Q. 2 and Q. 3.
(2) Use of steam table Molier chart is permitted.
(3) Assume suitable data, if required
Q. 1 Dry saturated steam at a pressure of 10 bar passes through the convergent divergent (10) nozzle. It leaves the nozzle at a back pressure of 1 bar, if mass flow rate of steam through the nozzle is 0.78 kg/sec Find:
(i) Pressure at throat
(ii) Velocity of steam at throat & at exit of the nozzle
(iii)Area at throat & at exit of the nozzle.
Q. 2 The steam issuing from the nozzle of an impulse turbine is 1180 m/s. The blade speed (10) is 350 m/s. The nozzle angle at inlet is 18 and outlet angle of blade is 2 less than at inlet. The mass flow rate of steam is 0.9 kg/sec. The blade velocity coefficient is 0.82.
Find:
(i) Power developed
(ii) Blade efficiency
(iii)Blade angles Solve graphically.
Q. 3 State the advantages of steam condenser. Explain working of counter flow type jet (10) condenser with neat sketch.
Q. 4 (a) Prove that efficiency of camot engine is always higher than that of irreversible (08) engine when both engines are operating in a cycle with same constant temperature source and sink. 2,}
(b) A heat pump working on the camot cycle takes in heat from the reservoir at 333K. (07)
The heat pump is driven by a reversible heat engine which takes in heat from a reservoir at 1113K and rejects heat to a reservoir at 333K. The reversible heat engine 3/4,6) also drives a machine that absorbs 30 kW. If the heat pump abstracts 17 kW from 278K reservoir. Determine the total heat rejection rate to the intermediate reservoir.
OR
(b) State the statements of Second law of Thermodynamics. Explain Kelvin Planck statement with neat sketch.
(07)
Q. 5 (a) A two cylinder C.I. engine with compression ratio of 13:1 and cylinder dimensions of 200mm x 250mm works on two stroke cycle and consumes 14 kg/hr of fuel, while running at 300 rpm. The relative & mechanical efficiencies of engine are 65% & 76% (08) respectively. The fuel injection is effected up to 5% of stroke. If the calorific value of the fuel is 42000 kJ/kg. Calculate the mean effective pressure developed.
(b) Derive the necessary relationship for evaluation of critical thickness of insulation for cylinder
OR
(b) Derive the general heat conduction equation in Cartesian coordinates for solid wall. (07)
=A=V=V=X=V=X=
4
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| Earning: Approval pending. |
