62236-mt----hydel Power Engineering

NR

Code No: 62236/MT

M.Tech. – II Semester Regular Examinations, September, 2008 HYDEL POWER ENGINEERING (Power Engineering & Energy SYSTEMS) Time: 3hours

Max. Marks:60 Answer any FIVE questions All questions carry equal marks ---

1.a)

b) c) 2.a) b) 3.a) b) c)

Explain (i) Storage and Pondage (ii) Firm Power and secondary Power (iii) Load factor and Capacity factor. Explain load study and estimation. What is Load duration curve. Explain. Explain the salient feactures of run – of – river plants and stroage plants. Discuss various classifications of hydropower plants. Discuss the general arrangement for a hydropower project in detail. Draw a neat sketch. Describe the design specifications for intakes. Explain the stability of surge tanks.

4.a)

Show that the efficiency of a free jet striking normally as series of flat plates mounted on the periphery of a wheel never exceeds 50%. b) A jet of water moving at 15m/sec impinges on a symetrical concave vane shaped to deflect the jet through 400. If the vane is moving at 6m/sec, find the angle of the jet so that there is no shock at inlet. Also determine the absolute velocity of exit in magnitude and direction and the work done per unit weight of water.

5.a) Draw a neat sketch of a pelton wheel installation and briefly indicate the functions of each component. b) The following data refers to a pelton wheel. Net head = 250m; Speed Ratio = 0.45, Nozzle coefficient 0.98; Jet Ratio 18; Over all efficiency = 76%, Frenquency of generation = 50 hz and pairs of poles of alternator = 6. Compute wheel diameter, jet diameter and power output is kw.

6.a) Describe the points of distinction between impluse and reaction turbines. b) Determine the speed, specific speed and diameter of a kalpan turbine to develop 5500 kw of power under a head of 8m. Assume speed Ratio = 2.2; flow ratio = 0.7, ratio of loss to runner diameters is 0.34 and overall efficiency = 85%. If the hydraulic efficiency is 92%, determine guide vane angle and runner vane angle at outer rim of runner wheel. 7.a) Explain different similarities in detail. Also explain similarity considerations of model and prototype turbines. b) A prototype Francis turbine develops 40000 MHP under a head of 240 m. Its speed is 500 rpm . Find a suitable model scale if the available discharge is 150 lps under a head of 30 m. Assuming an overall efficiency of 88%, determine the speed and power of the model. 8.

Write short notes on: (i) Under ground power houses – safety requirements (ii) Water hammer problems (iii) Forebay (iv) Governing of turbines.

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