WAVE ENERGY GENERATOR INCLUDING AN OSCILLATING GATE AND A PISTON PUMP

Abstract: The electric marine generator with an oscillating sluice-valve and a piston pump allows to exploit the waves' energy for the production of electric energy, the pumping of the water, the compression of refrigerating gases, and comprises: an oscillating sluice-valve (1) with a plane rectangular surface vertically arranged in front of the waves, provided at its base with a hinge (3) fastened to a reinforced concrete block (21), and with a helical spring (2) that allows the return of the sluice-valve when waiting for the wave; a pump (12) consisting of a cylinder (13) and of a piston (11) with a rod (10), having at one end a sliding hinge (5) inserted inside a guide (4) on the sluice-valve (1), provided with two springs (8, 9) for preventing the blows; in the bottom of the cylinder, the sending pipes (16) and the suction pipes (17) are connected, intercepted by the respective one-way safety valves (14, 15); two collectors - a sending collector (18) and a suction collector (19) - which, when connected with pipes (16, 17), allow the formation of pumping systems consisting of a plurality of pumps and respective sluice-valves and arranged in parallel for multiplying the effects; an airlock (CA) is connected to the sending collector for adjusting the motion of the water in the pipes.

Description: WAVE ENERGY GENERATOR INCLUDING AN OSCILLATING GATE AND A PISTON PUMP The present invention concerns a marine generator consisting of a structure that exploits the energy of the waves for the production of electric energy, for pumping water and for the compression of refrigerating gases. It is known that the existing marine devices usually exploit the vertical oscillating motion of the waves for producing mechanical and consequently electric energy, by means of an electrogenerator. It is the aim of the present invention to transform the energy of the sea waves into mechanical pressure energy, by means of an oscillating sluice-valve operated by the thrust of the waves against it, and which in turn operates a suction pressing pump with simple effect. The present invention allows many applications, and in particular: - as an electric energy generator, the pump may be used for raising the water into a basin existing or to be realized at a height superior to the sea level, and for using the position energy for developping electric energy, by means of a conventional hydroelectric system; - as a pump for raising the water from soils at a depth below the sea level and discharging it into the sea: this is a problem strongly felt in those Countries that have developped in areas below the sea level; - as a pump for compressing refrigerating gases to be used in the refrigeration industry, in particular the suction/pressing pump placed on the shore nearby a food-stuffs refrigeration installation, may be used as a compressor in the Carnot refrigeration process. The application of the system according to the present invention may be installed near those coasts where the steapness of the sea ground is rather uniform and not to high and without unevennesses, for avoiding dangerous reflected waves, at an optimal distance near an area of breakers or between the breaker area and the shore: A) Placing of the marine generator in h e breaker area: The swell coming from the high seas, while nearing the shore, continuously modifies due to the increasing friction with the ground, increasing its inclination, which means that the length of the waves decreases and their incline increases. When the ground is less than 1 ,3 the height of the wave, said wave is no longer stable: the orbital speed of the particles on the crest is equal to the quickness and the wave breakes, giving a thrust forward to the whole water mass that presses the sluice-valve, and thus frees nearly the whole energy stored in high seas. If the machine is placed there where the breaking of the average wave occurs, it is possible to catch the greatest part of the wave's energy. This shows that the optimal placing seems to be along an average sinking level line corresponding to 1 ,3 of the average height of the normal wave Ho of the place. If, for logistical reasons, the placement of the machine is to be realized on grounds deeper than 1 ,3 Ho, the breaking may be forced by means of an artificial inclination of the ground (slope) out of reinforced concrete. The wave that arrives near the machine is in a precarious stability condition and therefore when it breakes with the sluice-valve that intercepts it, it gives away its energy (kinetic + potential). The kinetic energy is linked to the orbital speed of the water particles, while the potential energy is linked to the raising of the crest's particles with respect to the average level of the sea, and t h e formula is: a H 2 L Y a H 2 L y a H 2 L E = Ec + Ep = + = 16 16 8 wherein E is the total enery of the wave, Ec is the kinetic energy, Ep the potential energy, a is the density of the sea water, H is the vertical distance between the crest and the trough of the wave and L is the length of the wave. The impact of the arriving wave with the intercepting element (the sluice-valve) generates a thrust that can make rotate said sluice-valve and consequently can operate the piston of the pump, compressing the water contained therein. B) Placing of the marine generator in the area between the breakers and the shore: When the oscillating wave breakes, the water of the crest falls onto the liquid surface before the arriving wave, causing a translation wave that continues towards the shore. Consequently, this kind of wave - that does not exist in the high seas - proves to be important in shallow waters within the breakers' line, where the oscillating waves nearly completely change into translation waves. These waves propagate at a speed V= where V is the translation speed of the water beyond the breakers, g is the acceleration of gravity and d is the sea ground after the breaking; with the feature that, as the height of the translation wave is considerable with respect to the depth of the water, they are to be additioned one to the other for obtaining the depth d. If the pump is placed in that area, the translation wave will give - due to the global equation of the dynamic balance - a thrust to the sluice-valve equal to the quantity of motion S= ~ ^ I V 2 A, where A is the surface of the sluice-valve hidden by the wave and V is the average speed of the translation wave, y is the density of the sea water and g is the acceleration of gravity. This thrust is applied at about 2/3 of the base hinge (centre of gravity of the speed triangle), i.e. in correspondence with the hinge of the pressing piston, and as the latter is inclined of about 30° with respect to the horizontal passing through the hinge, a compression force onto the piston rod is obtained equal to F=S/cos 30° = S x 1 .1 5, where F is the axial force along the piston. By varying the diameter of the pump also the flow and the outlet pressure may be adjusted F= pA = P ~ ^ ~ , where p is the pressure of the water in the cylinder, D is the diameter of the cylinder of the pump, A is the surface of the cylinder. As can be deduced from the formula, it is evident that with each wave that arrives a flow is generated equal to the volume of the der . At a parity of forces exerted, the equation of an equilateral hyperbole pQ=FI=K is obtained, i.e. to a high pressure corresponds a minimum flow and vice versa. This means that even at considerable heights with respect to the sea level water may be pumped, feeding existing reservoirs even at a considerable geodetic height. The sluice-valve must raise from the average sea level of an amount equal to the average height of the wave, so as to intercept it all and catch all its potential energy. For what concerns the applications of the marine generator according to the present invention, the pump is very versatile for the production of electric energy, because at a parity of thrusts onto the sluice- valve and consequently at a parity of pressing forces onto the piston of the pump, it is possible to intervene onto the values of pressure and flow, as the latter are linked by the relation pQ=FI =K. If the propulsive system is used for increasing the water in an already existing hydroelectric basin, the pressure may be chosen in such a way as to overcome the geodetic prevalence and the losses in the pressing piping, by simply varying appropriately the diameter of the cylinder. The flow of the raised water may be increased by coupling in parallel a plurality of machines by means of the suction/pressing collectors. Fresh water is used in a closed circuit - i.e. the water coming out from the turbine is introduced into the suction collector - so as not to use sea water in the pumping circuit: infact, the sea water would quickly damage the pump as well as the respective hydraulic turbine. By making a simple example it can be deduced that the machine according to the present invention may give considerable economical results. If said machine is placed between the breakers' line and the shore (just close by the latter), and considering a wave with an average height Ho=2,00 mt, a breaking for a ground is obtained equal to d=1 ,30 Ho = 1 ,30x2,00 = 2,60 mt, with a water translation speed V= 5,05 m/sec. If the sluice-valve has a rectangular surface with a base 1=3,00 mt and a height equal to the ground d=2,60 mt, and is able to produce the breaking, A=/d= 3,00x2,60 =7,80 m (A is the area of the sluice-valve), a thrust S=γ V A=1000/9, 81 x5, 05 2 x3, 00x2, 60 = 20.277kg is obtained, and a pressing force onto the piston rod F=Sx1 , 1 5=20.277x1 , 15=23.31 8 kg. If two pumps are laterally applied to the sluice-valve for balancing the charge, with pistons with an internal diameter of 50 cm with S=1 .963 cm 2 , and with a useful run of 1 .000 mt, a pressure p=F/2xS= 23.318/2x1.963=5,94kg/cm 2 is obtained. It has been calculated that in one whole day (24h) about 1 1 .000 complete cycles are obtained, and for . , 7 c o Λ „ Λ . each cycle a water quantity V=2— — * ■ • = 0,39 m is pumped, and that makes 4.323 m a day; that means that, if 200 useful days with waves with an average height Ho=2,00 mt may be calculated in one year, 4.323x200=864.600 nr year are obtained, pumped with a total prevalence of 59,40 mt of water column. From this all it may be deduced that, if a global output sending piping + turbine/alternator + adduction piping of 0.80 is assumed, in one year the energy obtained is: E=864.600.000 x 59,40 x 0.80/367.000 = 1 1 1 .950 KWh/year. The present invention will be described more in detail hereinbelow relating to the enclosed drawings in which some embodiments are shown. Figure 1 shows a scheme of a vertical section of a module that makes up the structure of the marine ge- nerator with an oscillating sluice-valve and a piston pump according to the present invention, with a sluice-valve and pumps placed in front of the waves. Figure 2 shows a scheme of a vertical section of a module of the structure with a conventional hydroelectric system with an airlock inserted in the sending collector for adjusting the water motion. Figure 3 shows a scheme of a vertical section of a variant of artificial inclinations of the ground for inducing the breaking. Figure 4 shows a scheme of a section of a module of the structure, applied to the evacuation of water from surfaces at a level below the sea level. Figure 5 shows a perspective, exemplificated view of a pumping system consisting of a plurality of single machines with a conventional hydroelectric system. Relating now to the details of the figures, the marine generator with an oscillating sluice-valve and a piston pump according to the present invention mainly consists of an oscillating sluice-valve 1 and of a suction/pressing pump 1 2 with simple effect. The oscillating sluice-valve, with its plane surface in front of the waves and preferably V-shaped on the other side so as to oppose the minimum resistance to movement inside the water during the active compressione phase, and placed orthogonally to the waves' motion and nearly perpendicularly to the sea ground, is provided at its base with a hinge 3 and is fastened in a concrete block 21 for allowing its oscillating movement. The suction/pressing pump 1 2, resting on a reinforced concrete base 21 by means of an appropriately shaped metal support 20, consists of a cylinder 1 3 and of a piston 1 1 having in the end thereof a rod 1 0 a sliding hinge 5 to be inserted inside the guide 4 fastened to the sluice-valve 1 ; a single sluice-valve is to be used with a couple of pumps 12 for balancing the stress transmitted by the waves, as said valve is provided with two guides 4 placed at the sides of said valve at about 2/3 from the base of the same, where the sliding hinges 5, placed at the ends of rods 1 0 of pistons 1 1 , are to be inserted, thus conferring to said sluice-valve a greater solidity. The support 20 carrying said pump 1 2 as well a s hinge 3, onto which said sluice-valve 1 is hinged, are f a - stened to the same reinforced concrete base 21 built is the sea ground. Two pipes with two safety valves - a sending valve 1 4 and a suction valve 1 5 - are inserted on the bottom of cylinder 13 of said pump 12. In the applications for the use of the marine generator according to the present invention for the production of electric energy, the two pipes 1 6 and 1 7 coming from the two valves 14 and 1 5 are to be connected to the respective sending connector 1 8 ad suction connector 19, thus allowing the formation of pumping systems in parallel for increasing the whole installation. The airlock CA is to be inserted in the sending collector 1 8 for adjusting the water motion in the pipings: otherwise, they will feel the effects of the variable motion of piston 1 1 . A cylindrical helical spring 2 is to be inserted in correspondence to the rotation axis of the sluice- valve 1 ; said spring is loaded during the active compression phase of the pump, i.e. during the impact of the wave, and is unloaded during the wait of a new arriving wave, bringing the sluice-valve back into its original position. The marine generator is provided witha safety device for preventing damages to the pump as well as to the sluice-valve, especially during particularly h eavy sea-storms. For reducing the violent blows of the sluice-valve against the pump body, a damping spring 8 is arranged outside cylinder 1 3 and another one inside piston 9 , for reducing the tearing stress due to the return of the sluice-valve. If the sluice-valve is to be stopped, a stopping system is provided so that the sluice-valve gets blocked in its greatest excursion, showing the waves that breake onto it with the smallest stress, its minimum surface, by means of a pin 6 arranged on the sluice-valve 1 that fits into a hooking 7 placed onto the support 20 of the pump. When the sea-storm is over, the hooking 7 - by means of an automatic electric control and according to the roughness of the sea - disengages said pin 6 leaving the sluice-valve free in its oscillation. The marine generator according to the present invention is coupled, as shown in figures 2, 3 and 5, to a conventional hydroelectric system consisting of an upper reservoir SS, of a turbine-generator group TG, of a lower reservoir SI and of an airlock CA, for adjusting the water motion in the sending pipe. In a possible variant of the marine generator according to the present invention, the same comprises - as shown in figure 3 - a reinforced concrete structure 23 that can force the breaking of the wave by means of the artificial reduction of the ground. Figure 4 shows the application of the marine generator according to the present invention for the evacuation of water from surfaces below the sea level: the pump sucks the water from the drainages 24 arranged close up to the outer breakwater below the sea level, through the suction collector 1 9, and discharges the water directly into the sea through the sending pipe 16. The structure realized according to the present invention shows the following advantages: - it allows to be placed near the shore in shallow waters; - it helps an easy maintenance, as it is near t h e shore; - it allows to couple in parallel a plurality o f machines forming a pumping system and multipying the effects; - it allows to feed already existing reservoirs even at considerable geodetic heights, due to its high pressure; - it allows to use fresh water at close circuit, thus avoiding to quickly damage the pump as well as the hydraulic turbine of the electrogenerator.

Claims: CLAIMS An electric marine generator with an oscillating sluice-valve with a piston pump, characterized in: - an oscillating sluice-valve ( 1 ) with its plane rectangular surface in front of the wave, V-shaped on the other side for opposing the minimum resistance to the movement inside the water, provided at its base with a hinge (3) to be fastened in a reinforced concrete block (21 ), with a helical spring (2) arranged along the axis of the sluice- valve and that gets loaded during the impact with the wave and then unloaded, bringing the sluice- valve back to the waiting position for a new wave, and provided at the sides with two guides (4), at a height about 2/3 from said base, into which sliding hinges (5), arranged on the rods (10) of pistons (1 1 ) of a pair of pumps (1 2), are to be inserted, thus allowing a uniform distribution of the stresses onto the machine; - a suction/pressing pump ( 1 2) consisting of a cylinder (1 3) and of a piston (1 1 ), whose rod (10) is provided at its end with a sliding hinge (5); on the bottom of the cylinder, sending valves ( 14) and suction valves (1 5) are placed, from which respec- tively a sending pipe (16) and a suction pipe (17) start; - two collectors - a sending collector (18) and a suction collector (19) - connected to pipes (16) and (17), which allow the formation of pumping systems, even in parallel, consisting of a plurality of pumps and respective sluice-valves; - a system for blocking said sluice-valve (1) by means of a pin (6) arranged on said sluice-valve (1) and that fits into a hooking (7) placed on a support (20), for stopping the oscillating motion of the sluice-valve if there are heavy sea-storms, and electrically distance-controlled for leaving it free to oscillate again when the sea-storm is over. 2. An electric marine generator according to claim 1 , characterized in the reinforced concrete structure (23) that forces the wave breaking by the artificial reduction of the ground. 3. An electric marine generator according to claim 1, characterized in that two dumping springs (9, 8) are provided for reducing the blows of the piston (11) as well as of the sluice-valve (1) against the pump body (12), one inside cylinder (13) and the other one outside the same.

Inventors: LOMBARDO MARIO, LOMBARDO, MARIO
Applicants: LOMBARDO MARIO, LOMBARDO, MARIO
Application year: 1997
Main classification: F03B13
IPC codes: F03B13, F04B17