GR1010196B - Cretan-type power generation wind mill - Google Patents

Abstract

The invented Cretan-type power generating windmill is composed of a sail generator of the Cretan-type wind pump, an electric power generator, a passive control and protection mechanism and a telemetric supervision and control system. The Cretan-type Sail Generator has 8 sails (1), it is passively controlled to be protected from extreme wind speed and it is provided with a remote-control and remote sensing system liable to sense its vital parameters. The control system is protected, not visible from the outside and contained inside the impeller’s carrier: the placement of two pulleys (22,23) allows the cable (24) to travel from the edge of the sail (25) to the springs (26) mounted on the front beam. These springs (26) allow the edge of the sail (25) to be retracted when subjected to heavy loads or when the rotor’s rotation speed exceeds a predetermined value. The retraction of the ring (28) allows the retraction of the wire ropes (24) and is done by sliding friction or ball bearings on the rods (29). Both the rods and the cables retaining the rings-spring bases (30) rest on the end rings (31) and (32) while the entire spring system along with the rods is protected by the housing (33). The nacelle is fixed either on the tower (fig.4) with wheels (34) or to the rotary shaft with a specially- shaped pin (18). The articulation 21 of the tail 20 allows, through its lifting, the access to the electromechanical parts of the mill (8) (9).

Description

DESCRIPTION

ELECTRIC GENERATOR WINDMILL OF CRETE TYPE

Definitions:

01.1. A sail engine is any device that produces rotary movement of an axis from the wind blowing on sails, i.e. sails stretched on a frame of beams and flexible elements.

01.2. A windmill is defined as any Sail Engine fitted to a machine that performs other useful work, such as a pump, an electric generator or a flour mill. So a windmill can be a windmill, a wind turbine, etc. A sail engine that drives an electric generator is called a wind turbine.

01.3. A Cretan type sail generator is defined as the one that has the shape of the wind turbine of the Lasithi plateau.

01.4. The Cretan Type Sail Generator, as defined here, is composed of the following elements:

. A Cretan-type wind turbine

. An electric power generator

. A passive control and protection mechanism

· A telemetric monitoring and control system

The Cretan Type Sail Generator has 8 wings (sails) and is passively controlled to protect it from extreme values of wind speed while it can have a remote control system and remote monitoring of its vital parameters. The control system is protected, not visible from the outside and is contained within the impeller carrier. Characteristic of the Cretan Type Sail Generator is its external aspect which has the form of a common Lassithio mill bearing a small generator.

The invention mainly concerns the placement of the control system within the structural elements of the fin of the Cretan Type Sail Generator. Innovations are added to the bearing of the propeller on the tower of the Cretan Type Sail Generator as well as to the bearing of the tail for functional reasons. The whole design of the Cretan Type Sail Generator aims to preserve the form of the Lassithio windsurfer.

Electric Windmills such as the Cretan Type Sail Generator have occasionally appeared both in the international literature and in operation, particularly in Crete as amateur or research prototype constructions. Some of the design solutions that were given for the control and the shape in general of the sail generators were registered as inventions and those that were considered directly or indirectly related to the Cretan Type Sail Generator are listed below. The main reason for the non-proliferation of this type of Wind Turbines is the inability of design solutions to provide a low-cost industrial product capable of being certified according to international standards, currently IEC61400_2 and its sequels. The said invention has been checked, regarding its agreement with said regulation and has been studied regarding its mass production and its cost.

In more detail, the patents registered to date related to this Cretan Type Sail Generator internationally are:

01.1.

US 2010303623 A1 / (DAWOUD GUIRUIS SAAD, YACOUB ANNETTA ATIA) [02.12.2010]. This patent is based on the basic principles of passive control of rotating machines in terms of control technique. The first such invention mentions Watt's speed regulator and in this patent it is applied with the possibility of changing the relevant elastic element and the use of a common spring, gas spring or hydraulic or electromechanical actuator. The claims of this patent focus on the form and function of the fin which is completely different from the patent applied in the case of the Cretan Type Sail Generator and is analyzed below. The fin of the US 2010303623 A1 patent is a large wheel with fins made of hard materials such as aluminum or wood and the whole form is radically different from the one proposed here.

01.2. W09112429 A1 (POVEN ENG PROD) 22.08.1991 This patent is also based on the basic principles of passive control of rotating machines in terms of the control technique. It should be noted that in both this and the previous one, the combination of wind pressure and centrifugal force excites the compression of springs or other elastic elements or mechanisms to change the pitch angle. Both the finning and the technique of implementation and application of the control mechanism are completely different. It should be noted that the PROVEN wind turbine is not even a sail generator like the one proposed in this patent, it is a classic small wind turbine with plastic, composite material blades.

01.3. GB2447506 A /(COOK GAVIN) [17.09.2008] This patent relates to a sail engine and indeed a Cretan type such as the one proposed with passive control based on the elasticity of both the sails and the elements that each sail is stretched on the antennas that make up bearing elements of the fin. This method can create an imbalance in the flapping due to a difference in the pitch angle of the sails moving independently and definitely differs from the passive control technique proposed below which synchronizes all the sails so that they have the same pitch angle.

01.4. GB 2098668 A / (CONTROL TECH) [24.11.1982] This patent concerns a sail engine and in fact similar to that of the Cretan type. The form of this passively controlled fin has many elements that make it different from the Cretan Windmill and, like the previous one, it does not synchronize the wedge angle of its sails but each moves independently under the influence of the centrifugal force and wind pressure. The comments made earlier also apply to her.

015 US2006171810 A1 (TRAVERE IND.) [03.08.2006] This is a passive control technique, like many others concerning small wind turbines such as US007172392B2, US008371813B2 and others. Description of the external functional characteristics and the similarity with the Cretan anemandlia. The attached Figure 1 shows the external form of the power mill next to a windmill on the Lasithi plateau. As shown in Figures 1 to 5, the Sail Engine consists of a winged, exact replica, outboard of the Cretan Anemantlia which has 8 sails (1) stretched on eight rods, the vanes (2). The antennas of the Cretan Type Sail Generator are made with tubes that contain the routing of the wire rope or any flexible element that leads the edges of the sails to their tension springs. In front of the impeller is nailed a ninth rod, the rigging (3) which carries on its free edge ties (4) for the 8 accents (5) that hold the antennae (2) at the desired angle with respect to the rigging. The frame is coaxial with the main axis (7) of the impeller. The shaft speed multiplier (8) is connected to the end of the impeller shaft and the generator (9) is connected behind it. A peripheral binding of the fins (10) completes the isostatic carrier of the propeller of the sail engine of a Cretan windlass. The impeller components (2,3) are connected to the shaft through the hub (11). The above elements are attached to the base of the mill head called the nacelle. The nacelle has the two elongated elements, the gadleys (12) and the bridges (13, 14, 15, 16). In front of the nacelle is the postitso (17), a bearing that can take axial and radial loads while the speed multiplier (8 ) with the generator (9) are fixed on the pads (12) at their other end. As shown in Figure 4, the nacelle has four wheels (34) that allow it to rotate on the roof plate of the mill tower. A perforated pin (18) is placed in the geometric center of the four wheels, through which the cable (19) of the generator passes, as in all Wind Generators. This pin also gives the horizontal loads of the impeller on the tower. The tail (20) is placed exactly as in the Cretan type windlass at the back after the generator and is hinged (21) on the nacelle.

04. Description of the innovation. The placement of the control system within the elements of the impeller is the main innovation of this invention which is mainly described in Figure 3. The placement of two pulleys (22) and (23) at the ends of the blades allows the wire rope (24) to run from the edge of the sail (25) to the springs (26) that are fixed on the rigging (3). These springs (26) allow the tip of the sail (25) to retract when it is subjected to heavy loads or when the speed of rotation of the rotor exceeds a predetermined value. The rotational speed of the rotor induces a centrifugal force on the weights placed on the wire ropes (27). The pulley (22) on the outer edge of the blade is hinged appropriately so that it can rotate according to the angle of the sail. The support of the springs on the frame can be done internally or externally. The result of this positioning of the passive control system is the external similarity of the power-generating mill with the Cretan windmill or Lassithiotiko mill. The retreat of the ring (28) allows the retreat of the wires (24) and is done by sliding friction or ball bearings on the rods (29). Both the rods and the retaining strings of the rings - spring bases (30) rest on the end rings (31) and (32) while the entire spring system with the rods is protected by the casing (33). Inside the nacelle and on its bridges are placed the boxes with the electrical and electronic components.

Claims (4)

PATENT CLAIMS 1. A sail generator characterized by the external form of its sail motor, which is a faithful copy of the Cretan windlass motor (Drawing 1). To this sail engine is added a generator (9) with a speed multiplier (8), a prewinding mechanism (34) (18) of the impeller and a passive control system (Diagram 3) with a combination of the effect of centrifugal force and wind pressure on an elastic element (26) or through an equivalent element force control for the controlled tension of the sails (1). The control mechanism is integrated within the load-bearing elements of the small Wind Turbine and in particular, within the tubular spars of the sails (the vanes) (2), the hub (11) and in a case (33) at the base and around the fore spar (the rigging) (3) according to Drawing 3. The mechanism is placed at the base of the rigging, inside or outside it. All kinds of ropes that stretch the sails of the propeller pass through the two ends of the wings (2), where they rest on the pulleys (22), (23). The rope, after being drawn inside the tube through the pulley (23), is guided to the ring (28) which rests on the edges of the springs (26) and slides with negligible friction on the rods (29). The distance between the rings (31), (32) that hold the system of springs and rods is adjusted with the strings (30). 2. Sail generator according to claim 1 characterized by the form of the support of the nacelle on the tower, as shown in Figure 4, which becomes a. with four wheels (34) suitable to allow the impeller to rotate on the roof plate of the mill tower and b. with a pin on the pivot (18) suitably shaped to pass the power and signal cables (19). 3. Sail generator according to claim 1 and 2 characterized by the joint (21) of the tail (20) which allows it to be raised in a vertical direction according to the Drawing 4. This ensures access to the electromechanical parts of the mill on the rear side of the nacelle when the mill is laid on the ground.