UA64264A - Wave power plant - Google Patents

Abstract

A wave power plant comprises a set of immersed into the water separated in space same units connected to each other by a main air duct. A separate unit comprises a fixed with respect to the bottom base, it is arranged as a vertical, closed from beneath hollow cylinder, placed in the base vessels with air, with adjoined to those at the outside chamber with a turbine, generator, control block and with a covering the base from above and able to move in vertical direction air shell. As an air shell there is used a not deformed at constant level of liquid, occupying the position of stable equilibrium under forces of air pressure balancing the weight of the air shell itself and the mass of liquid over it, structure.

Description

Description of the invention

The invention belongs to power engineering and can be used for the purpose of converting 2 wave energy.

A wave energy installation consists of a set of devices of the same type immersed in water, connected to each other by an air duct. A separate device is shown in Fig. 1. It consists of a fixed relative to the bottom of the base (1), made in the form of a vertical, closed bottom hollow cylinder, resting on a pipe-pile (5) immersed in the ground with its lower end and capable of moving vertically, covering the base from above, 70 air envelope ("sheath "), which consists of a convex surface (2) and two coaxial hollow cylinders (6 and 7). The dimensions of these cylinders are chosen so that the smaller one (6) is inside and placed in the liquid-filled annular gap (8) between the wall and the air containers (9 and 10), and the larger one (7) is outside the base cylinder.

Thus, the air envelope consists of two parts separated by a layer of liquid (8): this is the space 12 inside the cylinder (6) with the capacity of the base attached to it at a specific working moment ("working chamber") and the space between the cylinders (6 and 7), limited from below by base elements and water surface (11) ("shell 1.

The working chamber is connected to the atmosphere through a pipe (3) protruding above the water and a valve (4).

Air tanks placed in the base are used in different ways and differ in design. Some of them are ordinary tanks (9), which through a valve (12) can be connected to the working chamber (capacity 1"), others (capacity 2") have the shape of a glass (10), inside which a piston (13) is stirred, with connected through a rod (14) with an empty ball (16) immersed in the liquid (15) filling the lower part of the glass.

The volume of the sphere is chosen so that the pushing force acting on it from the side of the liquid balances the weight of the piston, the rod and the sphere itself. In the upper part of the cup there is a stop (17), which limits the movement of the piston.

This design works as follows: since in order for the piston to be at rest, the balance of air pressure outside and inside the container is necessary, then when the pressure in the working chamber changes, the piston will move in such a way that this equality is restored. Thus, in the case of a decrease in pressure, the piston will rise until it touches the spring gasket (18), which is placed around the perimeter of the limiter (17) and serves as a shock absorber and ensures the tightness of the connection. M

The exact correction of the volume of the working chamber is carried out as follows: the piston (20) with the valve (21) and the locking device (22) mounted in it is moved along the rod (19) located along the axis of the pipe-pile (5) Ge) and attached to it by the ends ). In the case when it is necessary to reduce the volume of the working chamber: close the valve (21), disconnect the locking device (22) and air from the working "I chamber" is compressed into the sub-piston space ("capacity 3"); to increase: open the valve (21), turn off the device (22) and the piston, under the action of its own weight, descends 3o. When the piston occupies the required position, close the valve (21), disconnect the locking device (22). eh

The volume occupied by the air in the tanks (9 and 10) is regulated by pumping the liquid (15, 23) into a special tank (not shown); pumps, locking devices, pipes, which are used to adjust parameters (air volume and pressure), are also not shown. "Shell 1" is connected through an air duct (24), a chamber (25), in which there are a turbine (26), a C 50 generator (27), a control unit (not shown), an air duct (28) with a main air duct (29) , fig. 2). c The air duct (28) is connected by a pipe (30) to the chamber (31) ("compensator"), in the form of a cup located at a certain depth, open from below, partially filled with air. The purpose of the compensator is as follows: when the water level (tide) changes, a corresponding movement of the shell is provided (described below); if the cross-sectional area of the compensator is equal to the cross-sectional area of the base elements not covered by water inside "shell 1", then the air pressure in "shell 1" does not change. b Under water between the cylinder (7) of the shell and the wall of the base (1) there is a screen (32) (attached to the "" of the base). It is designed to reduce the change in the water level (11) during shell oscillations.

A ballast (33) is located below the base in such a way as to balance the pushing force from the water side and to compensate for the asymmetric distribution of the mass of the parts making up the base.

Gee! 20 Along the perimeter of the side surface of the base cylinder (top), roller shock absorbers (34) are located, blocking horizontal movements of the shell.

T» To improve energy conversion, the part of "shell 1" (top) is separated from the main volume by the surface (35) (it can be connected to the working chamber).

In further calculations, it is assumed that the pressure in the main air duct (29) practically does not change during shell oscillations. This assumption is made on the basis of the following considerations: of course in the sea in irregular waves with variable frequency, direction and amplitude are observed (|1, P.308) and for a large number (several dozen) of the same type of devices scattered in space, the condition is met when the effect of one device is compensated by the effect of another, which oscillates in antiphase, and a sufficiently large the diameter of the air duct will allow to quickly redistribute the mass of air. When there are no loads (the turbine does not interfere with the air movement) 60 the assumption applies to "sheath 1" which is connected to the main duct.

In this way, the response of the shell to external changes is determined by Pa(x).

X - the position of the shell in relation to the equilibrium point (positive when the shell is deflected upwards);

Raso - the real dependence of the pressure in the working chamber on X;

Pv(x) - calculated dependence of the pressure in the working chamber on X; because Su is the cross-sectional area of the smaller cylinder (6) of the shell;

C» - cross-sectional area of the larger cylinder (7) of the shell;

Fulfillment of the condition that the dependence of Ра(х), if possible, coincides with Рд(х) is achieved as follows.

Suppose that the shell moves up (X is positive and increases), that is, the volume of the working chamber increases, and

Air pressure decreases. Let's choose three points X!, X2, XZ (X1I is less than X2, X2 is less than XZ3). These points correspond to three pressure values P d(x1), Pv(x2), Pv(x3). On the basis of experimental data (results of model tests; this also applies to the values of T1, T2, ТЗ), we find U1 - such a volume of air for which the transition from the state M1, Pv(х1), T1 to the state M1-C4(Х2- X1), Pv(x2), 12. Similarly, we find M2 (transition from state M2,

Pvih2), T2 to the state M2nS(X3-X2), Pv(x3), T3). To connect these two segments, it is necessary to change the volume 70 of the working chamber in X2 to the emission line -X11- m (1)

This is achieved by using the element "capacity 2", if the point of contact with the limiter (17) is X2, and the volume of the capacity at the moment of contact is equal to 4 (it is assumed that when the piston moves to the limiter, the temperature in the capacity changes similarly to the temperature change in the working chamber).

By dividing the range of changes in the value of X into the required number of segments and using the corresponding number of "capacitance 2" elements, it is possible to reproduce the dependence of Pv(x) (within the possibility of the proposed method). Let's show it on a concrete example.

Assume that the condition is fulfilled when the shell deviates from the equilibrium position

Era koh (2) - us

K is a given coefficient;

E; - the force that returns the shell to a state of equilibrium; d2 - the force of the weight of the water layer above the shell;

Ro- pressure in the working chamber in a state of equilibrium; c - water density; "

I - the acceleration of the force of gravity; where is the change in Pg when the shell is deflected to X (the shell is completely submerged); and in Seskhsdoo (Z) "Y

External changes are compensated by pressure changes in the working chamber and the ratio (Te) рах) Si KO AK A Sosrod AH (4) sch must be fulfilled after integration

Kk, c) h

Rvih)- Рр-х (2 vd s, s, (Se)

Let S.-140m2, Co-180m2, Ro-109n/m2, X varies in the range from minus one and a half meters to plus one and a half meters. Let's divide the X range into five equal segments. X; - the value of X for the limit points; and - point number (from top to bottom); "

Pv(xi) - value of function (5) at point X; with the corresponding K; -

Let us assume that the process of compression-expansion of air in the working chamber as a result of the deflection of the shell c can be considered adiabatic, that is, we consider: с» rom - sopvy (6)

For each segment we find U; from Eq

SKK vi - MS Ob - HO Rv os 3 vi (7

Me. m - the volume of the working chamber at point X, after excluding the "capacity2" element; - 4;- and empirical correction; ko dm - volume and element "capacity 2" at the point of contact X;;

Ge») 20 ym - the volume of the "capacity 2" element under equilibrium conditions; i» m, - the volume of the working chamber under equilibrium conditions;

Ame Ma sh; Hin M (8) 14 (9)

Bo mio » Vo and (10 more in) 79 a 32-33

Table 1 shows the results of calculations; Fig. 3 shows the dependence:

A. Rod -(1-0257 HO nIM

B. of playback (consists of five segments):

Rvikh; water r hkikhah; b5 pk -hoii m

We will give an explanation of the presented results. Within the framework of the mentioned assumptions, the dependence of R. them) reproduces well

Рв(хи - The device must have four "capacitance 2" elements with the following characteristics (at the equilibrium point, the ambient temperature): first: volume 167.2mU (equilibrium point); 201.8mU (touch point); second: respectively 190 ,7m7 and 201.9m3; the third: in the state of equilibrium, the piston is pressed against the limiter, the volume of the container is 202.2m3, the pressure is 177 pni; the fourth: the piston is pressed against the limiter, the volume of the container is 201.2m", the pressure is 41293 1p0bniMy '

The volume of the working chamber at the equilibrium point is 765.6 m3;

In order to transfer the device to the device from Kk 05: Sas dya (0.333 So add), it is necessary: first: pump 8.6m7 (11.9mU) of air; /5 second: pump 2.2m (3.4m3) of air; the third: lower the air pressure to 1p58 109 and 1073; fourth: lower the air pressure to 4174. 1073 4154. 1073

To increase the volume of the working chamber to 1018.2 m3 (1144 4 m3), that is, to attach to it elements "capacity 1" with a volume of 252.6 m? (378.8m).

In the case when the pressure in the working chamber at the equilibrium point is equal to the atmospheric pressure, the condition is fulfilled:

Raz (Sa STU RI Ragm.) 011)

Rz - shell weight;

P; - pressure in "shell 1" in a state of equilibrium; -

Rathm. - atmospheric pressure; "

The value of gz depends on many parameters: the used material, shape, strength requirements (the device can be used in case of significant disturbances, or can be preserved even in a small storm), taking into account operational features/ so the lower part of the cylindrical surface (6) can be lightened Because the main the load is taken by roller shock absorbers (34), which are located at the top; it is necessary to do this in order to reduce the losses associated with the displacement of liquid during the movement of this cylinder.

P, is calculated from formula (11). with vi- K (12) «

Mu Mo -M3 (Se) mu - shell mass;

M. - mass of water above the shell;

Ma - attached mass; ""is - the natural frequency of the oscillating system; With a change in the average liquid level, the position of the device can be adjusted. For this, when the level increases (decrease) it is necessary to increase (decrease) the volume of "tank Z" by, ya Su, to compensate for the change in air mass in n working chamber through valve (4) from the atmosphere so that it (mass) has not changed. ha - change in the average liquid level. o In case of a big storm, the shell can be lowered onto the base and fixed. For this, all the elements of "capacity 1" are attached to the working chamber, the valve (4) is opened and the shell is slowly immersed; at the specified depth valve (4) is closed, the elements of "capacity 1" are disconnected and air is pumped from the working chamber into "capacity 1" until the required depth of immersion is reached. When lifting, the elements of "capacity 1" are connected to the working chamber, after the initial ascent, insufficient air is pumped in air through the valve (4) from the atmosphere. b" The closest analogue of the proposed installation is the pneumoshell installed at the bottom (2, P.138),

T», but this device is not considered promising, and therefore it is advisable to compare it with the most effective, for example, Salter's "duck" (1, p. 314). For the Atlantic Ocean, waves with a period of 8,313 seconds (1, p.309-311) are the most characteristic (in terms of energy concentration). For Salter's "duck" in this range, a decrease in efficiency is observed (1, p.314). This is explained by the fact that that the surface transducers have an oscillation amplitude commensurate with the excitation amplitude.For the proposed device (ratio 12 to 2) the setting to a smaller

P needs a smaller K, that is, for the same effort (amplitude of disturbance), a greater deviation is needed to balance it: the shell "has time" to descend (and float) to a greater depth in a longer time interval. This increase in the amplitude of oscillation, as well as a lower speed of movement of the shell (friction losses), allows the device to be effective in this frequency range.

We will provide numerical estimates. For a shell in the form of a spherical segment (H-bm, K-8.2Zm), which touches the water surface at its upper point, P» - 3.884 obno Mo - 3963107 kg (at p-4103.10 bkglM o So - 1802 ). Rated 1-2

Eze 5 and 4,8. 10b nom ex 0731. 10bkg) At E -140m", r - 215 10 mute "IZ (17). 65 Let's assume that during movement Mi Mo Ma t 14 pe kg /ma more than twice m, hmM";/, then for is - 0.698 sec K - 0.582.102 kg/sec? (12).

From relation (2), he accepted P; AC and (A is the amplitude of the wave) we have 18 lo sov

And about ovals, that is, even with unfavorable estimates, we have a good result (the deviation of the envelope is twice the amplitude of the wave).

In addition to the expected high efficiency, the installation element has the following advantages: 1. Practically submerged in water (reduced effect of wind and waves). 2. It is point (does not depend on the direction of the wave). 3. Traditional energy conversion (the wind turbine is placed in a fixed, protected base). 4. It is relatively simple and convenient to manufacture (the structure can be manufactured from traditional materials (steel, concrete) at the shipyard and towed to the place of operation). 5. Relatively easy to preserve (in case of a big storm, the shell can be lowered onto the base and fixed). 6. It is an energy concentrator (the wave acts on the entire area of the (Cy5) shell, and the compression of the "working gas" occurs in the (C2o-C.) part of the shell, therefore the "response" to the external pressure change in Co(Co-C.) is greater ).

Fig. 1 shows a separate element of the wave energy installation, a longitudinal section;

Fig. 2 shows the entire power plant, top view;

Table 1 shows the calculation data of a specific example of the display of the theoretical dependence of Pd(x) by the dependence of Pa(x) (pressure change in the working chamber);

Figure 3 graphically shows: A. theoretical dependence Pv/(x);

B. the actual (predicted) dependence of Ра(х).

The air duct cross-section was estimated according to the formula (1, P.3791 « 2 (13)

RE-R- VE. v.Tot (ha - Hr. M. o t - constant 3.14; - - mass flow rate; « t ; - coefficient of resistance; i-th

EC - universal gas table; Het - absolute temperature; m - gram molecular weight/1000; With 0 - the diameter of the air duct; (Se)

Ri,R" - air pressure at points Hu and Ho, respectively;

ХХ" - the distance between points X. and Xo;

Calculations show that it is really enough to use pipes with a diameter of about 1.5 m. "

Frictional losses associated with shell vibrations were estimated using the formula |З, p.123)|: с с М- бе? in

Iz" in - density of water; n" - viscosity of water; c - area of the moving surface; е. frequency of oscillation of the shell; b A - amplitude of oscillation of the shell; "" M - average power of friction losses;

Calculations show that frictional losses are negligible; di In the calculations (Table 1), it is assumed that in the elements "capacity 2" during the movement of the piston is not allowed

Ge") 20 air flow from the sub-piston space into the working chamber, but the device is operable in the mode

Im (the value of M is selected when such overflow is possible, if it occurs slowly and is reversible (the equilibrium position of the piston does not change). In our case, this can be done because the pressure difference in the working chamber and in the sub-piston space during the movement of the piston is small and changes in sign, and when it (difference) ov is zero, the piston occupies a certain stable position (displacement of the piston leads to a change in the depth of immersion of the rod in the liquid (15), i.e., the pushing force acting on the system from the side of the liquid changes

P" piston-rod-ball, the equilibrium is disturbed, and the resulting force is directed so as to return the system to a state of equilibrium); to move the piston to a new equilibrium position, it is necessary to pump part of the liquid from the reservoir (placed on the piston; not shown in Fig. 1), thereby changing the weight of the piston-rod-ball system. Inside the base (1) it is possible to use a liquid with more suitable parameters (density, viscosity, effect on microorganisms), for example: a concentrated salt solution.

It is shown that the "compensator" (31) is created for each element (this makes the work of each element more independent: the disconnection of several elements does not significantly affect the work of the installation), but it is economical to make a general "compensator". 65 The housing of the shell can be thermally insulated so that the process of air compression during oscillations is less dependent on the environment.

The real dependence of Ru(x) should take into account such factors as the fact that the shell protrudes above the surface of the water when it is displaced upward from the equilibrium position; that the sum M»o-M» is a variable value; that it is necessary to reconcile Ru(x) with the curve of pressure change in the "shell" during energy conversion, and so on. Therefore, it is advisable to include experimental data (obtained during model tests) in the control program.

The wave energy installation works as follows (on the example of one device): when the air shell of a separate element vibrates (the shell is pre-tuned to such a natural frequency of oscillations, at which its movement will be optimal for the given wave) compression (expansion) of the air in the "shell" occurs and when it is squeezed through the turbine into the main air duct, /o energy is converted.

References: 1. J. Twydell, Uzyr A. Renewable sources of energy. Trans. with English M.: Znergoatomizdat. 1990. -

P.392 ill. 2. Korobkov V.A. Transformation of ocean energy. - L.: Shipbuilding. 1986. - P.280. ill. (Ocean mastering technique/5).

Z. Landau L.D., Lifshits E.M. Theoretical physics, vol. b6. Hydrodynamics. M.: Science. 1986. - P.736. » ry pika pohunny khtnnynny vn vn « shen vspetisya 203 ch zo z 03 F

Pvovvozvovvio | sch , - zv F "- s nn;" ov 11

Claims (2)

(2) The formula of the invention 1. A wave energy installation, consisting of a set of similar devices immersed in water, scattered in space, connected to each other by a main air duct; a separate device consists of (is) 50 stationary relative to the bottom of the base, made in the form of a vertical, closed bottom empty cylinder, T" placed at the base of containers with air, a chamber with a turbine, a generator, a control unit adjacent to them from the outside, and a covering base from above, capable of to move vertically an air envelope, which is distinguished by the fact that, in order to increase the efficiency and operational characteristics of the installation, the air envelope is used undeformed, with an unchanged liquid level, occupying a position of stable equilibrium, under the action of air pressure forces, balancing the weight of both the air envelope itself and the mass liquid above it, in. a structure that consists of a convex surface and two vertical coaxial hollow cylinders connected to it of such dimensions that the larger one is outside and the smaller one is inside the base, located with the lower part in the partially liquid-filled space between the wall and the containers with air and serves to divide the volume of the air envelope into two parts: the inner one, which can, if necessary, be connected to the atmosphere through the air duct installed on the air envelope, protruding above the water and the valve closing it, and to the air containers of the base, and the outer one, located between the cylinders of the air shell, bounded from below by the surfaces, the liquid in the base, the external water environment, the elements, the base, which separate these liquid environments and connected through the chamber with the turbine, generator, control unit, duct with the main duct. for 2. The device according to claim 1, which is distinguished by the fact that the air containers located at the base differ in design: some are ordinary tanks that can be connected to the inner part of the air envelope through a closing device, others have the shape of a glass, inside which a piston is placed, connected through a rod to a hollow ball immersed in the liquid filling the lower part of the glass, the volume of which is chosen so that the pushing force acting on it from the side of the liquid balances the weight of the piston, rod and ball, and in the upper part of the glass there is a stop that limits displacement of the piston. « « (Se) with « (Se) - with . and? (o) sh» name) (o) s» 60 b5