Renewable Energy Sources - May 2014
Mechanical Engineering (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. 1 (a) Determine the wind mill rotor diameter to operate a centrifugal pump, which will have a discharge of 40.000 litres/day with a total head of 10 m. The pump Operates for 10 hours in a day. The rated speed of wind is 6 m/s. The power coefficent is 0.3. Density of air is 1.2Kg/m3. Assume transmission efficiency 95%, Pump efficiency as 35%(6 marks) 1 (b) Define the following:
i. Solar Constant
ii. Incident angle
iii. Latitude angle.(6 marks) 1 (c) What are the non-conventional sources of energy and explain briefly(8 marks) 2 (a) Explain shortcomings and limitations to the existing energy sources(6 marks) 2 (b) Determine the altitude and azimuth angle at 3 pm (IST) on June 15, for Mumbai (latitude 6 18° 54N, longitude 72deg; 49E)(6 marks) 2 (c) Explain briefly about Vertical Wind mills with neat sketches(8 marks) 3 (a) What are the advantages and limitations of tidal power generation(6 marks) 3 (b) Write short notes on solar distillation(6 marks) 3 (c) Calculate the useful heat content per sq. km. of dry rock granite to a depth of 7 Km.Take the geothermal temperature gradient at 40° C/km, the minimum useful temperature as 140 k above the surface temperature and rock density of 2700 kg/m3(8 marks) 4 (a) What are the advantages and the disadvantages of Wind Power(6 marks) 4 (b) Explain briefly origin and types of geothermal energy regions(6 marks) 4 (c) In a closed cycle OT EC power generation system, water flow rate to evaporator = 1000 ton/hr, Ocean surface temp =25 degree C, Ocean temperature at 1000 m depth = 5° C, Density of sea water= 1000 kg/m3, Specific heat of sea water = 4200 J/kg° C. Calculate the power output of an ideal (based on Carnot cycle efficiency) OTECI plant in such conditions. Show all the parameters on a suitable diagram(8 marks) 5 (a) A micro-hydropower plant based on a reaction turbine has its head 60 m. above and tail race 5 m, above a datum level. Loss of head hf due to friction between head race and entrance of the turbine is 3 m. Assuming a hydraulic efficiency of 95 % for the turbine, and water density of 996 kg/m3, calculate the power developed by the turbine runner at a water flow rate of 0.20 m<sup3< sup="">/see. Show the system schematic diagram with all parameters</sup3<><>(6 marks) 5 (b) Explain operational and environmental problems of geothermal energy(6 marks) 5 (c) Explain briefly about the selection site for installation of a Bio gas plant(8 marks) 6 (a) Write short notes on hydropower conversion device(6 marks) 6 (b) Find the quantity of water to be pumped to OTEC plant working with surface water at 27° C and with cold water at 8° C at a depth of 600 m from the surface to obtain 1 .0 MW ot thermal energy. Assume the density of ocean water as 1010 kg/m3 and the specific Heat of water as 4200 J/kg K(6 marks) 6 (c) What are the benefits of Bio gas technology? What is Bio Mass? Write the percentage compositions of Bio gas?(8 marks) 7 (a) What are the components of Tidal Power plant?(6 marks) 7 (b) Write a short note on: Need for alternative energy sources(6 marks) 7 (c) What are the advantages of Fuel Cells? EXplain briefly about the working of Fuel Cell(8 marks)