US2641108A

US2641108A - Means for harnessing wave power

Info

Publication number: US2641108A
Application number: US15088A
Authority: US
Inventors: Seton J Montgomery; Ira P Macnab
Original assignee: WAVE POWER DEV Ltd
Current assignee: WAVE POWER DEV Ltd; WAVE POWER DEVELOPMENT Ltd
Priority date: 1948-03-16
Filing date: 1948-03-16
Publication date: 1953-06-09
Anticipated expiration: 1970-06-09

Description

June 9, 1953 s. J, MONTGOMERY ET AL 2,641,108

MEANS FOR HARNESSING WAVE POWER Filed March 16, 1948 2 Sheets-Sheet l June 9, 1953 s. J. MONTGOMERY ETAL 2,641,108

MEANS FOR HARNESSING WAVE POWER Filed March 16, 1948 2 Sheets-Sheet 2 Patented June 9, 1953 UNITED STATES PATENT OFFICE MEANS FOR HARNESSING WAVE POWER Seton J. Montgomery and Ira P. Macnab, Halifax, Nova Scotia, Canada, assignors to Wave Power Development Limited, Truro, Nova Scotia, Canada, a body politic and incorporate Application March 16, 1948, Serial No. 15,088

. 1 Claim.

The present invention relates to a method and means for harnessing wave power.

More specifically, this invention concerns a method adapted to translate the reciprocating vertical motion of coastal Waves into a continual positive flow, and includes also means capable of producing this result and generating useful power thereby.

The main object of the invention, therefore, is to provide a method by which useful power may be generated from waves.

Another important object resides in the provision of means for carrying out this method.

Still another object resides in the provision of coastal stations equipped with means of the character described and capable of steady gener ation of useful power.

Yet another object is to provide stations as set forth above which will develop a steady output of power at relatively low cost.

And another object is to provide stations of the character set forth which are of appreciable size and output, and may feasibly be disposed in series along the coast line.

And yet another object resides in the provision of equipment adapted to effectively transmit the power from the coastal generating stations above to a central power station.

Other objects and advantages will become apparent, or be further pointed out, in the description to follow.

As an example, and for purposes of illustration only, a preferred embodiment of my invention is shown in the annexed drawings, wherein:

Figure 1 shows, in diagrammatic outline, a plan view of a typical coastal station constructed according to invention and illustrates a preferred disposition thereof with respect to the coastline.

Figure 2 shows an enlarged plan view of a portion of the station of Figure 1;

Figure 3 shows an elevation view looking into the portals of the station of Figure 2;

Figure 4 shows a sectional elevation view through one unit of the station, and,

Figure 5 shows a plan view, partly in section, of a portion of the station. The method by which the invention seeks to translate the vertical wave movement into useful power consists as follows:

A plane surface, very nearly horizontal but inclined upwardly somewhat in the direction of wave travel, is interposed inthe" path of-the waves. The level of the surface will be somewhat below that of the lowest wave elevation. Upon meeting this obstruction then, the waves will commence to break and, their up-and down motion becoming translated by the incline into a forward acceleration, will rush up the incline at increasing speed. If now this onwardly-moving water be led through an orifice and passed to the rear in a confined flow, said flow preferably being directed somewhat downwardly, it is obvious that the force of the stream may be used to generate useful power. And the water may then be allowed to escape through a less-restricted rear opening.

It is a further preferred feature of the invention that the confined how be subjected to an abrupt, substantially-vertical drop shortly behind the restricted orifice, this portion of the stream being particularly suitable for the purpose of developing power.

Referring now to the drawings, wherein the same reference characters denote corresponding parts throughout, the method of the invention becomes quite clear upon examination of the practical applications thereof illustrated.

The several figures all show a typical coastal generating station wherein wave power is harnessed. In particular Fig. 1 indicates in plan a preferred disposition of such a station in the form of an elongated jetty on the sea coast in order to take full advantage of the prevailing direction of wave movement. Thus the waves will move into station S, which may be a reinforced concrete structure, in the direction indicated, and will escape at the rear as shown by the arrows.

Such a station S will, in general, consist of several wave-directing portals P, each of which is adapted to direct a confined stream as noted above and each of which controls the flow to a separate power-generating unit. The portals are successively staggered in the direction of wave flow as best shown in Fig. 2, and hence each undertakes its task of directing incoming waves at a different instant. The resultant effect of such a disposition is that the sum of the power developed in the station by the different units is smoothed out, as hereinafter described.

Figures 2 and 4 best show the general construction of the power station, Thus the foundation I0 preferably rests on bedrock and rises at the wave-receivin front to form an inclined 3 slab H. This slab is inclined relative to the direction of wave travel, as set forth above, and will preferably be completely awash at all .tidal periods. Surmounting slab H, and defining the boundaries of adjacent portals, are a plurality of upright piers l2. These piers rise to an elevation above high water and are wedge-shaped, the vertical sides of a pair forming a single portal approaching each other in the direction of the waves so as to guide the water toward the restricted orifice at l3. Overhanging this latter, and built as a wave-restrictin roof across the rear portion of adjacent piers, is a depending block l4 formed from the station superstructure. Thus the waves rush up slab ll, they are collected, at any portal, between a pair of inwardly-directed piers l2 and guided, beneath roof M, to the entrance leading to a single un-.

Figures 2, 3 and 4 show how the water driving into a unit entrance is utilized to develop power. In the entrance proper is disposed a trash gate l5 adapted to hold back any objects capable of damaging the unit, and just behind this gate a penstock. ['6 is adapted to carry the water onward in a confined stream. In the preferred embodiment illustrated, this penstock leads horizontally straight to the rear for a short distance ll, makes an abrupt vertical drop l8, and then extends at a horizontal angle 19 to the back of the powerhouse. From here, a diverging opening 20 leads out through the substructure to the tail water behind the station. This diverging passage decelerates the water issuing from the penstock and ensures that it re-enters the sea with a minimum of velocity and back pressure.

The means whereby the force of the moving stream in the penstock is utilized is best shown in Fig. 4, and preferably consists of one or more water wheels or turbines 2| disposed in the vertical section It of the penstock. Wheel 2| is keyed on an upright shaft 22 which thrusts, at its lower end, on a bearing 23 and drives into poweraccumulating machinery, indicated generally by 24, at the top thereof. The wheels proposed adopt the shape of the propeller type, having curved blades automatically adjustable to the velocity of the available stream of water. Shaft and thrust bearings will be made of hard rubber (water lubricated) or of anti-friction metal (lubricated by grease or oil under pressure) Across the penstock and at suitable locations are disposed a pair of shut-off gates whereby the turbine chamber may be isolated when necessary, as for instance when making repairs. Such gates are illustrated at 30 and ill, the former being disposed behind the entrance orifice and the latter at the rear end of the penstock. Hydraulic means 32 are indicated in Fig. 4 for the operation of these gates, the controls being inside the station. In addition, an access gate is provided for entry into the turbine chamber and is illustrated in. dotted lines at 33.

The proposed machinery into which the turbine shafts of the several units will drive are best shown in Figs. 4 and 5. Thus each shaft will operate an independent hydraulic pump 35, and all of the latter will discharge into a highpressure line 36, receiving the fluid to be pumped from a low-pressure line 31. These lines will be led shoreward or to any suitably located central unit where they might be adapted, for instance, to generate electric power through a turbine of the Pelton. Wheel type. That is, the highand low pressure lineswould constitute a closed sys tem wherein the fluid was driven from the pump chamber at high pressure through a Pelton Wheel turbine, and hence discharged back to the pump again at low pressure.

Obviously the operation of any single pump will be more or less spasmodic owing to the cyclic nature of the wave-impelled streams of water passing through the penstock. However, this effect is greatly modified owing to the plurality of pumps connected to the high-pressure piping and which, owing to the staggering of the portals, are brought into play successively at very small intervals. In addition, and to remove all pulsations from the line 36 where it performs its useful work, it is a feature of the invention to provide one or more air-loaded hydraulic accumulators between pumps and hydro-electric turbine.

Considering the design of the structure generally, where it projects from the land into the waves, it may be noted that great care will be exercised to avoid having any surfaces at right angles to the direction of wave-approach. Thus all surfaces which might be subject to heavy impact from the onrushing mass of water will be streamlined so that no shock will result. With proper precaution in design, no destructive shock need be feared even during storm conditions.

Clearly, from the foregoing, the method and apparatus herein disclosed are capable of fulfilling the primary objectives set forth. The method, properly employed, will lead the vertically oscillating masses of water into confined streams capable of imparting useful power to con ventional machinery. Moreover, the invention includes and reveals extremely effective means for utilizing the method, particularly applicable to sizeable power stations disposable on sea coasts. The type of coastal station described is obviously capable of developing a steady power output and, since auxiliary structures for damming water and providing huge reservoirs thereof are not necessary, such a station will enable low cost power to be generated in coastal regions without the burden of supplying fuel. The stations may be located, as noted, in series along the sea coast. Finally, an arrangement of machinery and equipment has been proposed which will enable such stations to transmit their power, as by hydraulic means, from a series of locations to a central hydro-electric powerhouse.

It will be understood that we do not limit ourselves to the particular embodiment of our invention herein shown and described, since obviously various changes might be resorted to respecting the size, shape and arrangement of the various features of the station, as well as its equipment, without departing from the spirit of the invention or the scope of the subjoined claim.

Having thus described my invention, I claim:

An installation of the character described for extracting useful power from sea waves by transforming the oscillating motion of said waves into a movemennt of translation, said installation comprising an elongated jetty so disposed that its longitudinal axis will extend at an angle to the line of advancing waves, said jetty having front and back faces parallel with said longitudinal axis, a plurality of vertical piers projecting forwardly from said front face at an angle with said longitudinal axis so as to be perpendicular to said line of advancing waves, each pair of adjacent piers defining therebetween a space for receiving and laterally confining a portion of an advancing wave, said jetty having penstock openings in said front face between said piers, an inclined slab depending from said jetty below said penstock openings and extending forwardly downwardly from said jetty, penstocks disposed within said jetty and extending rearwardly from said penstock openings, said penstocks having a horizontally extending front portion, adjacent said openings, so disposed that its axis will extend parallel to said piers, said penstocks having furthermore a vertical portion and a back horizontal portion, the latter extending at right angles to the longitudinal axis of said jetty, diverging exhaust passages aligned with said rear penstock portions and opening in said back face of said jetty, and power extracting turbines located in said vertically extending penstock portions.

SETON J. MONTGOMERY. IRA P. MACNAB.

References Cited in the file of this patent UNITED STATES PATENTS Number Number