The present invention relates generally to the field of devices for sea-wave power generation. Further, the present invention relates specifically to the field of sea-wave power generation plants. The sea-wave power generation plant comprises a turbine having an inlet opening and an outlet opening; a rig; and an axially extending pump unit, wherein the stationary body is connected to said rig, wherein the pump unit comprises an axially extending stationary body, at least one diaphragm connected to said stationary body, and a pump chamber for a fluid, the pump chamber being at least partly defined by said at least one diaphragm, said pump chamber being connected to the inlet opening of the turbine.
Wind waves contain wave energy which basically is accumulated and stored wind energy. Further energy conversion to electrical energy can be made by the means of using a sea-wave power generation plant. In recent years, the interest to exploit renewable energy has increased. The use of certain types of energy, such as solar energy and wind energy, have increased rapidly while the exploitation of wave energy from water waves still remain relatively low in use. There is worldwide potential for the procurement of wave energy, which can be done with low environmental impact.
There are several challenges in the procurement of the wave energy as the energy source itself is inaccessible and displays a variable flow of energy. The energy flow of wind waves is a function dependent on wind speed and distance traveled for the accumulation of wind energy, where variations in wind speed and direction produce variation among the waves. Thus, the wave energy is an irregular source, where the irregularity affects the dimensions of the design. Wave energy is a clean and persisting source of energy, but it is a technically difficult challenge to produce a stable and efficient energy transformation and to do so in a cost efficient way.
There are various methods for energy transformation from wave energy. U.S. Pat. No. 4,145,882 disclose a sea-wave power generation plant comprising a pump chamber defined by a big flexible bag, and a turbine located in said bag. When the bag is exposed to forces originating from sea-waves a liquid housed in said bag is pumped through the turbine. However, the function of the sea-wave power generation plant of U.S. Pat. No. 4,145,882 is questionable, especially since the plant is solely arranged to be located at the bottom of the sea, independent on the depth of the actual location. The forces origination from sea-waves decreases in the vertical direction, and at great depths this power generation plant is of no use. The present invention is directed to a sea-wave power generation plant arranged to extract energy from the kinetic energy created by the water waves below or adjacent the surface.
The present invention aims at obviating the aforementioned disadvantages and failings of previously known sea-wave power generation plants, and at providing an improved sea-wave power generation plant. A primary object of the present invention is to provide an improved sea-wave power generation plant of the initially defined type that is efficient and that extracts energy with a steady flow and high efficiency that at the same time has a low environmental impact.
The surface of the waves both rises above and falls below the level of the still water surface. Under the surface the water particles are set in motion. There are different theories about the exact movement, but can easily be described as the single water particle in its motion has a vertically plane circular orbit at greater water depths and a more elliptical orbit at shallow depths. During the time of a wave period, the wave has traveled the distance of a wavelength, i.e. the distance between two wave crests. In that same time, an arbitrary water particle has moved one lap in its orbit. By placing a device in the water below the surface, as a barrier to the movement of the water particles, energy is obtained from the force applied onto the surface of the device. The patent relates to a sea-wave power generation plant for extracting energy under the surface from the kinetic energy created by water waves. The sea-wave power generation plant uses the energy described above, and in particular the energy created by the vertical upward and downward motions in the water.
According to the invention at least the primary object is attained by means of the initially defined sea-wave power generation plant having the features defined in the independent claims. Preferred embodiments of the present invention are further defined in the dependent claims.
According to the present invention, there is provided a sea-wave power generation plant of the initially defined type, which is characterized in that the pump unit comprises an axially extending movable body connected to said at least one diaphragm, the movable body in the radial direction being arranged for reciprocating movement in relation to said stationary body in order to alternately compress and expand the pump chamber in order to pump said fluid to the turbine.
The device is arranged under the surface and encloses fluid and can be completely, or partially, covered by a flexible diaphragm. The diaphragm of the device is affected by forces created by the, below surface, kinetic energy created by the water waves. The force to the diaphragm applies pressure onto it and causes it to move, which also sets the device and the fluid enclosed by the diaphragm, in motion. At the opposite side of the diaphragm, within the device, an stationary body is placed, and when the diaphragm is subjected to pressure, the pressure moves the diaphragm towards the side of the stationary body whereby a constriction occurs between the diaphragm and the stationary body where the motion in the diaphragm and the constriction momentarily moves in the axial/longitudinal direction along the diaphragm, in synchronism with the movement of the waves on the surface at the sea. Thus, the diaphragm presses the fluid in the direction of the motion of the wave. The unit includes a device for extracting energy from the kinetic energy created below the surface and by the motion of the waves.
The energy is then extracted by transferring the fluid through a turbine. The sea-wave power generation plant comprises a closed loop that circulates the fluid within the sea-wave power generation plant, or an open circuit with an inlet and outlet for fluid into and out of the sea-wave power generation plant. The fluid is transferred through the sea-wave power generation plant by pumping fluid at the movement of the constriction synchrony with the movement of the waves on the surface at the sea.
In the device for pumping and propulsion of fluid within a closed circuit/loop, the level of filling within the device is adapted so that one or more constrictions between the diaphragm and the stationary body may be contained within the device simultaneously. The device for pumping and propulsion the fluid in an open circuit operates with the phases of intake, constriction between the diaphragm and stationary body, pumping and propulsion of the fluid, in which one or more constrictions between the diaphragm and the stationary body may be contained within the device simultaneously. The device with an open circuit is containing fluid, the volume of which is adjusted to the size in the phase of intake. The number of constrictions within the device of a closed or open circuit is dependent on the length of the device and the current wavelength of the surface; thus, the device uses part of a wavelength, full wavelength or multiple wavelengths simultaneously within the intended area of energy absorption for the device. With several simultaneous wavelengths flowing over the device for pumping and for propulsion of fluid, a more uniform fluid flow is obtained through the turbine for extracting energy from waves of the water.
Pressure on the enclosed fluid within the device for pumping and propulsion the fluid is amplified by a movable body, e.g. a wing, which by the forces of the movements in the surrounding water transfer these onto the diaphragm.
A device for pumping and propulsion of fluid uses, in a single-action design, the vertical upward and downward motions in the water which then provides a pumping and propulsive power per wavelength. According to one embodiment, the device for pumping and propulsion of fluid is of double-action design, i.e. utilizes both the vertical upward and downward motions in the water, which then generates two pumping and propulsive effects per wavelength.
The sea-wave power generation plant may be an anchored under water device or a fixed bottom-anchored device.
The sea-wave power generation plant can be connected to a buoyancy device.
The invention of the sea-wave power generation plant has one or more of the following characteristics:
Further advantages with and features of the invention will be apparent from the other dependent claims as well as from the following detailed description of preferred embodiments.
A more complete understanding of the abovementioned and other features and advantages of the present invention will be apparent from the following detailed description of preferred embodiments in conjunction with the appended drawings, wherein:
a-3e schematically illustrates and explains the operation of the device for the pumping and propulsion of the fluid,
a-4q are examples of alternative embodiments of the device for the pumping and propulsion of the fluid,
a-5d illustrates different embodiments of the stationary body device for the pumping and propulsion of the fluid,
If sea-wave power generation plant 1, according to
a-3e explain a schematic sectional view, in the direction of the water wave motion, of device 2 in
a illustrates device 2 with a flexible diaphragm 6 the stationary body 7 and the contained fluid 8 in an unaffected embodiment in calm water 9.
b illustrates a water wave 10, with the direction of movement from left to right, approaching device 2 and the diaphragm 6 which is affected by the forces created by the water waves 10 and the kinetic energy created below the surface of the water. The force against the diaphragm 6 applies pressure to the diaphragm 6 and sets it in motion, which momentarily within the device 2 and by the diaphragm 6 enclosed fluid 8 also is set in motion. At the opposite side of the diaphragm 6 a stationary body 7 is placed and when the diaphragm 6 is subjected to pressure, it moves the diaphragm 6 towards the side of the stationary body 7 whereby a constriction occurs between the diaphragm 6 and the stationary body 7.
In
In
In
a-4q represents a schematic sectional view, transversely to the pumped fluid 8 in its direction of motion energy, of the diaphragm 6 and stationary body 7 corresponding to that of
a illustrates a flexible diaphragm 6 in two basic designs where the left one, in its execution, has an open periphery and in the right version, it has a seal around its periphery. A sealed diaphragm 6 can also be shaped like a hose.
b illustrates a flexible diaphragm 6 where the edges of the left-hand embodiment of the diaphragm, as appropriate, is secured to an stationary body 7 and together they form an enclosure for fluid 8.
In the right-hand embodiment, the diaphragm 6 is enclosed in its periphery and by, as appropriate, applying the attachment points on the diaphragm 6 the diaphragm 6 will form an own stationary body on which the attachment points are stretched and therefore extend the diaphragm 6.
c illustrates a single-acting design with stationary body 7 and the diaphragm 6 oriented upwards, towards the surface.
d illustrates a single-acting design with stationary body 7 and the diaphragm 6 oriented downwards from the surface.
e illustrates a double-acting design with the stationary body 7 and the diaphragm 6 on each side of the stationary body 7.
f illustrates a double-acting design with diaphragms 6 with at least one circumferentially enclosed diaphragm 6 and where the stretched diaphragm 6 is used as a stationary body 7.
Device 2, for pumping and propulsion of fluid 8, uses a single-action design either capturing the upward or downward movements of the water, which then provide a pumping and propulsive power per wavelength. Device 2, for pumping and propulsion of fluid 8, when utilizing a double-action design, captures both the upward and the downward movements of the water, which then provide two pumping and propulsive effects per wavelength.
g illustrates an embodiment with an attached movable body 15 whose side tips are, appropriately, attached to the sea-wave power generation plant 1. The movable body 15 may come in the form of a flexible sheet of materials and are secured, as appropriate, to the diaphragm 6.
h illustrates an embodiment with an attached movable body 16 whose side tips are not secured. The movable body 16 may come in the form of a rigid sheet of materials and are secured, as appropriate, to the diaphragm 6.
i illustrates an embodiment of a movable body 17 which is hinged at the center, or divided in a two-part, whose outer side tips are not secured, but have a support or an attachment, which inverts the movement of the inner lateral tips. The wing 17 is fastened, as appropriate, to the diaphragm 6.
g-4i illustrates embodiments where the pressure of the contained fluid 8 is amplified by a movable body 15, 16-17 which by absorbing the energy from the movements in the surrounding waters and through transmission of the power to the diaphragm 6 for applying pressure against the device 2 and its enclosed fluid 8.
j illustrates an embodiment where the diaphragm 6 is assembled with dividers for the separation of the contained fluid 8. The divider is flexible and it limits the vertical mobility of the diaphragm 6 and can also be used, if necessary, when there is a need to allocate the flow within the device 2.
k-4l illustrates a version of device 2 with several, by the diaphragm 6 separated, enclosed devices of fluid 8. In device 2, several separate enclosures can be performed within the width or the height, or in a combination of both.
m illustrates a design with two diaphragms 6 around their open circumferences. The diaphragm is in its bottom part attached, as appropriate, to the stationary body 7 and in its upper part, as appropriate, attached to the movable body 15, 16-17 which together encloses the fluid 8.
n illustrates an embodiment similar to the design 4m described, but with a shortened movable body 15, 16-17 which causes pressure to build on the contained fluid 8.
o-4p illustrates two double-acting designs.
q illustrates examples of how the above described embodiments, according to
A diaphragm 6 with or without a stationary body 7 as shown in
a-5d illustrate examples of embodiments that are not limited for the invention of the stationary body 7 in which
The device, 2 shown in
The device 2, as illustrated in
The invention is not limited only to the embodiments described above and shown in the drawings, which primarily have an illustrative and exemplifying purpose. This patent application is intended to cover all adjustments and variants of the preferred embodiments described herein, thus the present invention is defined by the wording of the appended claims and the equivalents thereof. Thus, the equipment may be modified in all kinds of ways within the scope of the appended claims. It shall be pointed out that all information about/concerning terms such as above, under, upper, lower, etc., shall be interpreted/read having the equipment oriented according to the figures, having the drawings oriented such that the references can be properly read. Thus, such terms only indicates mutual relations in the shown embodiments, which relations may be changed if the inventive equipment is provided with another structure/design. It shall also be pointed out that even thus it is not explicitly stated that features from a specific embodiment may be combined with features from another embodiment, the combination shall be considered obvious, if the combination is possible.