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# NOVEL METHOD OF GENERATING HYDROELECTRIC POWER USING COLLAPSIBLE BLADDER

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I had presented this presentation in world hydro power conference 2012 held in New Delhi. It was grand success

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### NOVEL METHOD OF GENERATING HYDROELECTRIC POWER USING COLLAPSIBLE BLADDER

1. 1. A NOVEL METHOD OF GENERATING HYDROELECTRIC POWER USING A LARGE COLLAPSIBLE BLADDER Dr Uday Prashant
2. 2. BASIC CONCEPTS My discovery involves two basic concepts 1) Flow induced collapse in collapsible tubes 2) Fluid structure interactions in flexible tubes This combinations leads to development of novel hydroelctric turbine which functions at very low heads and low flow conditions efficiently
3. 3. • With conventional turbine technology it is practically impossible to extract power from such low energy density flows – head 1 -2 m range, flow rate 0.3 – 0.4 litre/ sec velocity 1 -3 m/sec. Power in 1- 4 w & efficiency 60 – 95 % Actually even lower flow conditions it is possible to generate power with this method but I lacked proper instrumentation to do so
4. 4. • High head: 100-m and above- Pelton wheel require low flow rates; 10 -30 cubic m/sec • Medium head: 30 - 100 m; Francis require moderate flow rates 30 -70 cubic m/sec • Low head: 2 - 30 m; requires large flow rates. 50 – 100 cubic m/sec • For Pico power project :- A 1 kW scheme could acquire its energy from 200 m head with a flow rate of 1 litre/sec or 2 m head with a flow rate of 100 l/sec . With current technology either of them must be large i.e high energy density flows are required for operation conventional turbines efficiently
5. 5. Basic principle of all turbines • The power extraction from fluid arises from turning the flow of jets. • The fixed blades are stators and rotating blades are rotors. • The change in momentum of jets causes reaction on rotatory blades and transfers energy to shaft.
6. 6. V= Absolute velocity of fluid Vr= Relative velocity of fluid Vw= Whirl velocity Va= Axial velocity of flow u = Velocity of the moving blades m = V A (Area of blades)
7. 7. In low energy density flows in hydrokinetic turbines are but they are inefficient and dependant upon velocity of water which is limited under natural conditions What if we have turbine which will do away with these jets & vanes or blades and operates by entirely different mechanism then we can produce energy at even at low flow and head conditions which was previously not possible.
8. 8. Specific Speeds
9. 9. • More specific speed – lower efficiency and increases cost • Large heads---- large reserviors/dams– submerge large areas of lands--- possible only in mountain areas which act as natural reserviors, • Large flows--- disturb entire course of river flow------ very costly ---lot of civil work required--- long term can cause earthquakes
10. 10. Ultra Low Head Turbines
11. 11. Zero Head floating Hydrokinetic devices work like wind mill – low efficiency
12. 12. Novel turbine –Novel principle • The flow is instantaneously reduced. Steady continuous flow is converted to unsteady pulsatile flow by collapsible bladder • There is large negative pressure “WAVE” generated travelling at speed of sound in water. • This pressure wave interacts with specially designed flexible tubes with elastic supports and transmits energy.
13. 13. Advantages • It works at very low Heads 1 – 2 m • It works at very low flows also – viable even at such low flows 250 ml/sec • It works in lower velocities 1 -3 m/sec of flow • It is very cost effective/ economically viable . No concept of specific speed, works in wide flow conditions
14. 14. Advantages • It can be used in small streams also. • Doesn’t require complex civil engineering work • Can be installed in few days of time. • It is environmentally friendly (fish friendly) • It is mobile and can also be easily shifted and installed in other locations with similar flow conditions
15. 15. Schematic diagram of novel pulsatile flow generator
16. 16. Working Principle • Bladder collapses because of Venturi effect, or application of Bernoulis Principle • FSI or waterhammer effect causes the cycle to repeat and converts kinetic energy of water to pressure wave which is inturn converted to motion of pipes
17. 17. Formulae • From Joukowsky equation” dp = d * c * dv dp is pressure surge developed during the water hammer c is velocity of sound in water dv is change in velocity which is same as V = (2gH)1/2 as after collapse velocity is zero & H is height of baldder from . ground
18. 18. • The pressure energy acts on entire surface of the u and straight tube and ther force acting on it is given by • F=P*A • A = 2* pi * r2 + 2*pi*H • If f is the frequency; s is amplitude of ocillations then power generated per second is proportion to P * A * f * s •
19. 19. Vertical Height fixed at 1.8 m from bladder to lower end of distal straight tube of diameter 12 mm. Spring constant 38 kg/m Volume of flow in l/sec Frequency no/min Force in Kg Amplitue in cm Newton Power avialable Power in watts Hydraulic efficiency % 0.18. 136 3 1 kg 3.1w 0.76w 24 0.2 128 8.5 1.085 3.6w 1.2w 35 0.222 114 9 1.125 3.9w 1.8w 45 0.227 115 8 1.150 4w 3w 75 0.25 112 10. 12. 4.4w 3.9w 89 0.3 106 10.5 12.50 5.3w 4.77w 90
20. 20. When Flow rate is fixed at 250 ml/sec and height is varied the power and efficiency. Vertical height in cm Freq of oscill per min Amplitude In mm Max Force Per Oscillation in Kg Power available in watts Power generated watts 30 96 1 0.1 0.1w 0.03w 0.42781 50 92 30 0.5 0.49w 0.32w 35 96 91 54 0.7 0.7w 0.41w 47 130 86 70 1 0.98w 0.67w 63.7 150 97 76 1.12 1.1w 0,8w 80 165 58 85 1.25 1.3w 1.0w 64 Hydraulic efficiency
21. 21. Frequency and amplitude of oscillations 140 120 100 80 60 Frequency of oscillations per min Amplitude of vibrations in mm 40 20 0 Flow rate in ml/sec
22. 22. Variation of frequency with height at constant flow rate of 240 cm^3/sec frequency and amplitude of oscillations frequency of oscillatons Amplitude of oscillations 120 100 80 60 40 20 0 30 50 96 Vertical height in cm 130 150 165
23. 23. Hydraulic efficiency % as flow rate is increased and when height is fixed 180cm 100 90 80 70 60 50 40 30 20 Hydraulic efficiency % 10 0 0.18. 0.2 0.222 0.227 0.25 0.3
24. 24. When the area of tube is increased from 12 mm to 18 mm and thickness of rubber balloon is doubled (1.5 mm) and rest of parameters held constant following observations are noted. Height =1.5m Vol of water Flow in cc/sec Freq of oscill per min Amplitude In mm Power available from flow in watts Power generated in watts Hydraulic efficiency in % 0.18 136 45 2.6w 1.7w 65 0.2 128 55 3w 2.4w 80 0.22 114 65 3.2w 2.9w 92 0.23 115 55 3.3w 2.16w 65 0.25 112 70 3.6w 3.42w 93 0.3 106 80 4.4w 4.2w 95 0.33 100 85 4.9w 4.48w 92 But increasing further flow caused rupture of bladder due to the stresses and hence my further experiments fur stopper at larger diameter than ¾ inch pipes
25. 25. Hydraulic Efficiency of apparatus at various flow rates in liter/sec when other paramerters are constant 100 90 80 70 60 50 40 30 20 10 0 0.18 0.2 0.22 0.23 0.25 0.3 0.33
26. 26. STEADY FLOW: CHOKING, FLOW LIMITATION AND ELASTIC JUMPS
27. 27. Pressure recorded distal to collapsible bladder when all conditions constant Time in sec 0 -20 -40 Pressure in mm Hg -ve -60 -80 -100 -120 -140 -160 -180 -200
28. 28. Theory of Waterhammer • The bladder once collapsed must remain in same state under ordinary conditions. • But due to flexible ‘U’ tube with elastic supports it comes out of collapse state and extracts energy by water hammer effect. • Water hammer effect is when velocity of flow changes too rapidly (t< 4L/C where L is length of tube and C is velocity of sound in water (1200m/sec))
29. 29. Types of Coupling • The most significant mechanism is the junction coupling, others are Poisson and friction coupling • Wiggert D.C, Tijsseling, A. S (2001)- Junction coupling is taken place due to unsupported discrete points of the piping systems such as unrestrained valves, junctions, closed ends, pumps, etc. • MOC (Method of Charecteristics) and FEM (Finite Element Method) are used to solve structural equations.
30. 30. A.S. Tijsseling; A.G.T.J. Heinsbroek; THE INFLUENCE OF BEND MOTION ON WATERHAMMER PRESSURES AND PIPE STRESSESProceedings of the 3rd ASME/JSME Joint Fluids Engineering Conference July 18-23, 1999, San Francisco, California
31. 31. A hydraulic ram or impulse pump is a device which uses the energy of falling water to lift a lesser amount of water to a higher elevation than the source but never used for power generation.
32. 32. Conclusions • Novel technological innovations may solve some of basic limitations inherent in current hydro electric turbine designs • My model is in pilot stages and needs considerable refinement and in large scale has to be rigorously tested. • Lastly if similar technological principles were used in design of gas turbine then results may be more significant and have far reaching impact
33. 33. When something is new, they say "it's not true". When its truth becomes obvious, they say "it's not important". When its importance cannot be denied, they reason, "it's not new". William James
34. 34. Thank You