Wave energy conversion Gentova А.А., Kovalenko S.V. Scientific advisor: Chizhiumov S.D. - презентация

1 Источник: Wave energy conversion Gentova А.А., Kovalenko S.V. Scientific advisor: Chizhiumov S.D.

2 Energetics of Kamchatka and Kuril Islands is primarily based on oil and coal. Due to the high transport costs, electricity generation costs are higher than the global average of 5-6.

3 At the same time, average annual potential of wave energy on the east coast is estimated at 40 kW/m. The technical potential of wave power on coast of 10 km can be 150 MW. It is the energetics throughout Kamchatka.

4 Classification of wave power converters

5 Overtopping Wave Energy Converter (OWEC) The principle of the converter OWEC is based on the potential energy of waves, which flows over the wall due to different water levels from different sides of the wall.

6 The wave converter of OWEC type is adopted as the basis : h

7 Wave power station Oyster (Great Britain) Oscillating wave surge converter (OWSC)

8 Disadvantages of OWEC: - High losses of wave energy on the front wall; - low flow rate in the channels of hydraulic turbines; - poor performance when exposed by small short waves; - icing at low temperatures. Disadvantages OWSC: - Efficient use of only large waves when there is intense swinging of "leafs"; - The probability of shifting and destruction of installations by storm waves. The aim of the work: to eliminate weaknesses and combine the advantages of OWEC and OWSC

9 Numerical analysis of OWEC

10 Flow velocity in the underwater channel, m/s The flow rate in the underwater channel is uneven. Velocity at the outlet, associated with the hydrostatic pressure difference between the reservoir and the sea level, is relatively low.

11 Front wall usually sloping to the sea. However, calculations showed that wave crest on steep slope increases not much more than on vertical wall. As a result, a small wave not overflows the front wall. Efficient growth of a wave crests is only on a gentle slope and declining channel (type TAPCHAN), but in this case the wave energy is essentially lost due to viscous friction. Most important, that the size, and hence the cost of construction is essentially increases.

12 Technical contradiction: If make a gentle slope to concentrate waves energy, most of the energy is spent on friction, and small waves just do not reach the camera. If apply a vertical wall, a large part of wave energy is expended on the wave reflection from the wall.

13 In result has been selected wall having vertical underwater part and sloping upper surface: But, still wave is partially reflected from the front wall, goes back and extinguishes aft wave.

14 In the reservoir formed internal waves. Extreme waves cause strong blow to the deflector, which can lead to its destruction or to overturning the whole structure: In the channels on turbines the flow is uneven: As a result, some water overflows back:

15 Physical contradiction 1: Deflector is needed to capture the waves at the camera, but it should be removed, as it leads to sloshing of large waves out of reservoir, and extreme waves can lead to the destruction or overturning the whole structure. We apply standard methods to resolving this contradiction: PRINCIPLE "BACKWARDS" - from fixed to moving deflector; PRINCIPLE OF DYNAMICS - characteristics of the object should be optimal at each stage (when the waves go forward and roll back); to divide object on parts that can move relative to each other; PRINCIPLE OF CONTINUITY EFFICIENCY - all part of the object must work at full load in each phase of wave movement; PRINCIPLE "TURN THE HARM TO BENEFIT" - to use the harmful effects (impacts of storm waves to the deflector) to obtain a positive effect (to take energy of impact and reduce the load on the whole structure). ?

16 Lets apply movable hinged deflector, which driven due to waves impacts. The motion from deflector passed to hydraulic energy converters. As a result, the efficiency increases. In the reservoir does not formed large sloshing. In addition, movable deflector less resists to extreme waves, this increases the reliability of the structure.

17 Physical contradiction 2: Front wall must be high, in order to large waves reflected from the deflector is not splashed back, and should be low in order to small waves overflows through her. We apply standard methods to resolving this contradiction: THE PRINCIPLE OF LOCAL QUALITY - the top part of the front wall should be in the most appropriate situations; PRINCIPLE "BACKWARDS" - to make fixed upper part of the front wall of the moving; PRINCIPLE OF DYNAMICS - the height of the wall must be optimal at each stage (when the waves goes forward and roll back) to divide front wall of the parts capable of moving relative to each other; USE OF MECHANICAL VIBRATIONS - cause swinging of stationary parts with using of these oscillations.

18 Hydrostatic pressure can be increased, if the sloped part of the front wall make hinged and floating. In this case the height of the front wall will be automatically regulated.

19 Physical contradiction 3: The front wall is needed, to hold water and create pressure in the reservoir. But this wall must be removed, as it discards most of the wave energy. Further development is the use of wave energy, which lost at the reflection from the front wall. The reflected waves extinguished by the next rolling waves. As a result, their energy is lost in the crush of the waves before front wall. We apply standard methods to resolving this contradiction: PRINCIPLE "BACKWARDS" - make wall not rigid, but supple; PRINCIPLE OF DYNAMICS - characteristics of the walls should change so as to be optimal at each stage (when the waves goes forward and roll back) to divide object on parts of that move relative to each other; PRINCIPLE "TURN THE HARM TO BENEFIT" - to use the harmful effects of waves on the underwater part of the wall to obtain a positive effect (direct using of energy).

20 First variant: The valves in the front wall, which allow to leak to reservoir and lock in the reverse flow.

21 Final result: Converter with the movable front wall working like «Oyster» system

22 Thank you for attention