| WO2008074320A1 | 2008-06-26 |
| US8192161B2 | 2012-06-05 | |||
| US20090304507A1 | 2009-12-10 |
| Claims [claim 1 ] A wind turbine with retracting blade and deformable cross section with a vertical force reduction blade and a cable transmission system comprising: A root part, wherein it is connected to the hub and all the retractable parts go to inside the root; At least 1 retractable part, wherein after the cross-sectional area is collected, it goes inside the root part to reduce the length of the blade and strengthens the root part, and when the retractable part mouth is opened, the next part of the blade is placed inside it; An aerodynamic part of the blade, wherein it never enters the root section; A vertical force reduction blade wherein; it is installed to the blade and by creating a force opposite to the vertical force of the aerodynamic part of blade reduces the vertical force and torque on the root part; and A Cable power transmission system, wherein power is taken from the blades and delivered to the generator by a cable system. [claim2] according of claim 1 a wind turbine with retracting blade and deformable cross section with a vertical force reduction blade and a cable transmission system further comprising: at least a reinforcement structure between blades. [claim3] According to claim 1 , root has a power transfer arm wherein it transmits power to a cable power transmission system. [claim4] according to claim 1 retractable part comprising: A main structure, wherein the vertical and horizontal force is transmitted from the previous retractable part to the next retractable part and is placed previous part within structure and the rest of the components are installed to structure; At least four shells, wherein is installed to the structure and is installed to the other shells by the shell movement system; At least four shell movement systems, wherein adjusts the distance between the shell and acts as a hinge when folded and each of these systems is responsible for moving a quarter of the cross-section; At least eight shell rotation systems, wherein moves the shell attached to the structure to its retracting or extending position; At least two airbags, wherein the task is to extend and retract the shells as well as the stiffness of the blades when changing the cross section; At least eight Vacuum clamps, wherein are installed on the shells and when the blade is retracted, separate the fabric from the shell and hold the fabric to the shell when the blade extend; A fabric, wherein addition to protecting the blade from sunlight and frost covers all the pores of the shell; and At least two reinforcement, wherein is installed in the tail and head part of the blade and in addition to strengthening the head and tail it causes the transfer of horizontal force from one part to another. [claim5] According to claim 4 the main structure comprising: A wind ward structure, wherein has a spray cup and at least two webs; A lead ward structure, wherein has a spray cup and at least two webs and is connected to wind ward in the neutral axis and can only move linearly perpendicular to the cross section; At least two wind ward & lead ward cable support system, wherein is responsible for controlling the linear motion perpendicular to the wind ward and lead ward; At least one inflatable wheel, wherein addition to opening the mouth of the structure is responsible for moving the previous part into the next part; At least two wheels to overcome the vertical force, wherein is installed to the wind ward & lead ward and is responsible for harness the vertical force during the movement of the section; and At least two wheels to overcome the horizontal force, wherein is installed on all parts and is responsible for preventing horizontal movement. [claim6] According to claim 5 wind ward & lead ward in the first retracting part has a wedge section that binds the first part to the root and in the rest of the section has a tab that fixes the previous part with the next part after closing the mouth part. [claim7] According to claim 5, the wind ward & lead ward holder cable system, which has a cable that is zigzagged and passes through the pulley connected to the wind ward & lead guard section, reaches the end of the part and is loose and tighten by a cable puller. [claim8] According to claim 5, the inflatable wheel system comprising: A center treadmill system, wherein it makes the Inflatable tube move easily; An Inflatable tube; and An exterior treadmill system, wherein prevents friction of the Inflatable tube with the structure wall. [claim9] According to claim 5, the wheels to overcome the vertical force only allows linear movement perpendicular to the cross section. [claimlO] According to claim 4, the shells have latch that if the airbag is inflated, it can only move linearly and prevent the hinge from rotating, and if air bag is empty, the hinges can be rotated. [claiml 1] According to claim 4, the shell movement system comprising: At least one three-piece hinge, wherein can move linearly and rotary and is controlled by a hinge guide cable; A Hinge guide cable, wherein it starts from the structure and after passing through the three-piece hinge reach to the tail part and the other end of the hinge guide cable is installed to the central hinge guide cable; A central hinge guide cable, wherein the hinge guide cables are installed at the front of the part and leads to the end of the part where the motor of the central guide cable is and it is responsible for adjusting the hinge guide cable; and A motor of the central guide cable; wherein is responsible for adjusting the central guide cable of the hinge. [claim12] according of claim 11 shall movement system is used for lead of cross section. [claim13] According to Claim 4, the rotating system of the shell comprising: A Shell movement rail, wherein the shell moves inside the rail by two rollers and rotates as the shell moves; A Shell moving cable, wherein the two ends are mounted on either side of the shell and is moved by the shell moving motor; and A Shell moving motor, wherein is installed to the structure and it is responsible for moving the shell moving cable. [claim14] According to claim 4 of the vacuum clamps comprising: A Fix part of the vacuum clamp, wherein is mounted on the shell; A movable part of vacuum clamp, wherein the guide rod allows the moving part has liner movement; and An air bag of the vacuum clamp, wherein is installed between the fixed part of clamp and the movable part of clamp and controls the linear movement. [claim15] According to Claim 4, the reinforcements have latch that are fastened within the reinforcement of their before and after retractable part. [claim16] According to claim 4, flexible photovoltaic shell can also be used for fabric. [claim17] According to Claim 1 , a vertical force reducing blade is mounted on blade and has a motor and gearbox to determine the angle of attack. [claim18] According to Claim 1 the cable transmission system comprises: A base of the power transmission system, wherein the whole system is connected to it and is installed on one side to the tower and on the other side to the hub output shaft; At least one power transmission cable, wherein connects the teethes; At least 3 teethes, wherein they act like gear teeth and transfer power from the blade to the cable and from the cable to the generator pulley; Generator pulley, wherein it transmits power from the teethes to the generator; At least 3 pullies, wherein leads the cable. [claiml 9] The method of A wind turbine with retracting blade and deformable cross section with a vertical force reduction blade and a cable transmission system comprises: Method of retracting and extending the cross sections; Method of Cross-section deformation; Method of retracting and extending parts; Method of retracting and extending the blades. [claim20] According to Claim 19, the Method of retracting and extending the cross sections comprises: To retracting the cross-section, first vacuum clamps blow up high-pressure air into the fabric for separate the fabric from the shell surface, and the hinge central cable motor begins to loosen the cable, and at the same time the airbag deflates and the rail collector of the shell system attached to the structure begins to collect the primary shell; The hinges that are bent together have elastic tube to make the assembly easier, and at the end of the work, all the shells are placed in the space embedded in the structure; And to extending, first an air bag is inflated and then the guide cables are tightened, and after the forming, first the air bag of the vacuum clamp are inflated to stick to the fabric, and to prevent the air caught, all the clamps blows up air to fabric; vacuum it from the lead of cross-section of the clamp first, and then the air bag of vacuum clam is vacuumed. [claim21] According to claim 19 Method of Cross-section deformation comprise: Each cross-section consists of four shall movement systems that control a quarter of the cross-section; When the upper side of the tail loosens its cable due to the pressure of the airbag and the latch of the shell the tail moves downward and the lower deformation system is loose, the tail moves upwards, and if both loosen, the chord increases; This is also possible for the cross- sectional of lead area. [claim22] According to Claim 19, Method of retracting and extending parts comprise: The system of retracting and extending of first part is different in the other part; In the first part, the blade cable puller system prevents the first part from retracted , and in retract of blade, overcoming horizontal and vertical force restrained vertical and horizontal force; It is possible to reach the inflatable wheels; The central treadmill is able to liner movement in perpendicular to the cross section and surrounds the part and accompanies it to the end; When it reaches to end path , the amount of inflatable wheel pressure increases for strengthens the root and support of tip of retracted part. To retracted the rest of the sections, first the wind ward & lead ward holder cables are loosened and the inflatable wheels are inflated inside the section to open the structure’s mouth; When the structure’s mouth is opened, the lock between the two sections is released and the blade puller system insert pervious part to next part and inflatable wheel accompanies part to end path at the end of the open part, it has a tab and lock that when opening mouth part is closed two part is fixed together and then the cable system holding the wind ward & lead ward is tightened and the inflatable wheels are inflated to support the tip of the part and the force distribute in whole pervious part . [claim23] According to claim 19, Method of retracting and extending the blades comprise: To overcome the torque of the weight, the blades are retracting and extending individually in a vertical position; For this purpose, when retracting the blade, it is retracted vertically and downwards so that the unbalanced torque causes the blade to rotate; For extending operation is done in upward vertical. |
Technical Field
[0001] This disclosure relates to renewable energy, especially wind energy and wind turbines.
Background Art
[0002] The retractable blades are divided into two categories. The retracting blades from the tip, all parts produce energy and the space of the retractable part must be considered inside the previous part (US2713393-US200302223868- US20030230230898-US20100158687-W02009095758) the second group is collected from the root, the first part close to hub don’t produce energy, in fact the root part is fixed and the tip of the blade has a space that accommodates the root part.
[0003] Regarding the change in the cross section of the blades, the inventions (EP3587798-EP2610127) mostly have mechanism, especially in the tail section of the blade, which changes the angle of attack, and the inventions (GB2332894- JP2013217372-US7632068-US9086054) tail separately is moved by mechanisms. The invention of the EP2341245, tail and lead is moved by a hinged mechanism, US7938623 is made from a solid center and a shall, the space between is filled with air, which is easier to transport.
[0004] In the case of the US 9989038 transmission system, it has a ring around the blades and is located under the wheel and gearbox rings.
Technical Problem
[0005] Wind turbines have the largest share of renewable energy. Today, with the help of advanced materials and computer analysis is made blades with length about 120 meters and weight about 65 tons and tip speed of 100m / s and a maximum energy of 15MW, cut in 3m/s wind speed and reaches a maximum rate in 10 m / s and cut out at 25m / s. On the other hand, all wind turbines only reach a maximum rate at one point. one of the reasons for this problem is the maximum speed of the blade tip, which cannot exceed 100 m / s, the second problem is the vertical force of the blade. Aerodynamic section of blade is made maximum of Torque in the direction of rotation and perpendicular to the direction of rotation. The torque generated by the vertical force increases the weight of the blade so that about 15% of the initial part of the blade occupies about half of the total weight of the blade. Another problem of turbines is gearbox, which is directly at low rotational speed and high rotational speed using gearbox.
Solution to Problem
[0006] To solve the said problems, we need a turbine with retractable blades so that the shape of the blade does not change. The shape of the blades is one of the important parameters in the design of turbines and with the slightest change in the shape, it causes a sharp drop in efficiency. On the other hand, as the wind speed increases, the wind force also increases and this retractable blade should be in such a way that when decreasing the length, increases the strength of the root part. Because of torque that is made by vertical force of aerodynamic section, root section should be designed bigger and when the blade is fully retracted and the rotation speed increases, a more aerodynamic root part should be designed for reduce of drag force. For solve of this problem, the vertical force of the aerodynamic part must be reduced. On the other hand, the existing inventions in the field retractable blades in such a way that it has an empty space inside the previous part, and in fact the blade changes in a stepwise manner. In the modern blades additional of chord, cross section is changed in length that ' s mean if a chord of cross section is smaller than chord of other section because of shape of cross section smaller cross section don’t fit to previous section as a result, we are not dealing with a homogeneous shape in the other side even though increase torque of root section but spar cap thickness of the aerodynamic section is bigger than root section. And the reason for that is the distance from the neutral axis in the bending because of the stairs in blade, it causes a disturbance in the movement of the wind and as a result, the efficiency decreases. The existing inventions do not create a good return on cost according to what has been said. Advantageous Effects of Invention
[0007] The present invention has improved the existing blades without changing its shape and using special mechanisms in such a way that in addition to the ability to adjust the blade length, it does not change the shape of the blade. Also, the design principles of this invention are based on giant turbines and in addition to changing the length, it has the ability to change the shape of the cross section during operation and it has a vertical force reduction system and it is strengthened root part by reducing the length. All this makes the blade lighter. On the other hand, it has an eccentric transmission system that creates a variety of speed and torque. With this description, we can design a turbine with more output power.
Brief Description of Drawings
[0008] [Fig.l] view of whole shape of the blade.
[0009] [Fig.2] the cut section of the blade.
[0010] [Fig.3] the vacuum clamp system.
[0011] [Fig.4] the shell movement system.
[0012] [Fig.5] how to change the cross-sectional area of the retractable parts.
[0013] [Fig.6] the tail and lead reinforcements.
[0014] [Fig.7] how the shell rotation system works.
[0015] [Fig.8] the method of retract the blade.
[0016] [Fig.9] how the first part is retracted.
[0017] [Fig.10 how the second part is retracted.
[0018] [Fig.l 1] the cable pulling system.
[0019] [Fig.12] the cables power transmission system.
[0020] [Fig.13] vertical force reduction system.
Description of Embodiments
[0021] Figure 1 shows the whole shape of the blade. As you can see in this figure, the blades are made up of several retractable parts (1) and each part goes inside the previous part and this operation is done from the root (2). The part that is put into operation is covered by fabric (3) that is resistant to the sun or can be used by flexible solar cells for cover the pores of parts.
[0022] Figure 2 shows the cut section of the blade. As shown in the figure, the blade is composed of a thin layer of fabric (3) which covers the circumference of the shells (4) and tie together with vacuum. The shells (4) are connected by the hinges that described in the other section. Shell (4) is also connected to the structure. It should be noted that the structure part (5) remains fixed in the tail and lead exist a reinforce (6). Reinforce of tail and lead (6) and structure (5) transfer force to another part under the shell (4) air bags (7) are embedded which play the role of generating internal pressure in order to form and collect the shell (4).
[0023] Figure 3 shows the vacuum clamp system for the fabric holder. A thin layer of fabric (3) that is covered the entire circumference of the blade by vacuum clamps
(9) that are installed on the shells (4) and fixes the fabric (3) to the shell (4) in the form of a vacuum. Vacuum clamps (9) include a fixed part of the vacuum clamp
(10) which is fixed to the shell and the moving part of the vacuum clamp (11 ) which have liner movement by rods(12) inside the fixed part (10) and the air bag of the vacuum clamp (13) which connects the fixed part of the vacuum clamp (10) and the moving part of the vacuum clamp (11 ) After the retractable part (1) came out of the previous part and became operational, first the air bag of the vacuum clamp (13) is inflated and the moving part of the vacuum clamp (11 ) come out and the compressed air blow up of the central part of the vacuum clamp (9) inside the fabric(3). For prevent of air catches the fabric (3) and changing the shape of cross section, it starts sucking from the front of the blade and the fabric (3) is connected with a vacuum clamp (9) and then the air bag (13) is emptied and the fabric (3) is attached to the shell (4).
[0024] Figure 4 shows the shell movement system. This system allows a slight change in the shape of the cross-sectional of the blade for change the angle of attack and increase or decrease the chord. Two adjacent shells (5) with a hinged system three pieces (14) are connected to each other, which is adjusted by the guide cable of hinge (15). the guide cable of hinges (15) passes through the inside of the hinge through the rollers of hinge (16) and reach the tail of the blade. When guide cable of Hinge (15) is loosed and three pieces hinge (14) is moved by airbag pressure (7). On the other hand, shell (4) has latch (17). if the airbag (7) is full, Latch (17) only allows that the shell is moved and if the airbag (7) is emptied, the shell (5) can rotate. The shell movement system is placed at certain intervals in retractable part (1) and all of them are connected to the central guide cable of hinge (18). at the end of the retractable part (1 ) has motor of the central guide cable hinge (19) is responsible for loosening or tightening the cable. Each retractable part has (4) shell movement systems which is installed on the four sides of the blade.
[0025] Figure 5 shows how to change the cross-sectional area of the retractable parts. Each retractable part (1 ) consists of four shell movement systems, and if the cable is loose at the top of the tail region of the retractable part (1 ), the tail of the retractable part (1 ) is moved downward and when the lower of the tail region of the retractable part (1 ) is loosened, the tail of the retractable part (1 ) is moved upwards and if all four cables are loosened, the amount of chord changes and the same happens for the head part.
[0026] Figure 6 shows the tail and lead reinforcements. The two reinforcement sides
(6) have latch that are attached to the other retractable part reinforcements.
[0027] Figure 7 shows how the shell rotation system works. After emptying the airbag
(7), the central guide cable of the hinge (18) is loosened and the three-piece hinges (14) are completely released. The shells connected to the structure (5) using the shell rotation system (21 ) goes to the position close to the web (8) and the shell (5) has rollers (22) which move inside the rail of shell rotation system (23). The cable of shell rotation system (24) is installed on both sides of the rollers (22) and after passing the rounded section of the rail (25) reaches the motor of shell rotation system (26). By rotating the motor, the rollers move inside the rail and reach their final position. Each of the shells (5) can rotate only in one direction and the two corresponding hinges at the top and bottom the bent side has elastic band (27) to position when the shells are collected, and the two corresponding hinges whose vertical position does not change relative to each other with cable (28) that position when the shells are extended as you can see in the figure, the shells are positioned next to the web (8) and are ready to be retract.
[0028] Figure 8 shows the method of retract the blade. To achieve the minimum force to retract the blade, we place the blade in a vertical position, in this case we only have to overcome the weight force, otherwise we have to overcome the torque of wight, which is far more than the force of weight. If the blade is retracted, the center of mass is changed and a lot of torque is needed to rotate the blade. To do this, place it in a position that does not require torque. For this purpose, for retracting it is placed in a downward vertical position and for extending in an upward vertical position.
[0029] Figure 9 shows how the first part is retracted. In the whole blade, the part of aerodynamic and root part is made of solid . for this reason, the way the first part is assembled is different from the rest. Each structure of part (5) includes of two section wind ward (5a) and lead ward (5b) and each section include of a spray cup (5c) and two webs (8). The first retracted part (29) has two wedge shape (30). This wedge shape is stuck to the root wall (31 ) and prevents the retractable part coming out from root. The first part (29) has wheels for overcoming vertical force (32) which are placed inside the rails that the rails are connected to the root web (31 ). wheels (32) are attached to the plate holder the vertical wheel (33). The plate (33) is connected to the wind ward and lead ward of part (29) through the wheels (34) and allows the liner movement to the wind ward and lead ward. (The linear part of the wind ward and lead ward is explained in the next figure.) The wheels for overcome the horizontal force (35) attached to the web of the part (29) for prevent horizontal movement.
[0030] We use inflatable wheels (36) to hold the front of the blade. The inflatable wheel (36) is composed of three section. The center treadmill system of the inflatable wheel (37) that include of fabric of the central treadmill system (39) which covers the rollers of the central treadmill system (38). The inflatable tube (40) and the outer treadmill part also includes the rollers of the outer treadmill system (41 ) and the fabric of the outer treadmill system (42). The central treadmill part is designed to easily rotate the inflatable tube (40) and the outer treadmill part is to prevent friction of inflatable tube (40) with the root’s walls. The central treadmill part can move linearly in a direction perpendicular to the cross-sectional of the blade. Now, when the blade reaches to these inflatable wheels (40) the first part collects without any connect with the root’s wall (31 ) and causes the force to distribute throughout the root part during work and prevents the concentration of tension. There is also the possibility of adjusting pressure of air inside the inflatable tube (40).
[0031] Figure 10 shows how the second part is retracted. The first part (29) and the second part (43) in section (43a) has a lock and a tab that causes the transfer of force from the second part to the first part. For retracting the second part (43), the mouth of the first part (29) is opened and the second part goes inside to the first part. The first part (29) has two sets the wind ward of first part (44) and the lead wind of first part (45), which are separated in the place of the neutral axis and are connected by the guide rod (46) and the guide bush (47). The wind ward and lead ward section (29) are fixed to each other by the wind and lead ward holder cables (48). The pulleys (50) are connected zigzag to the top and bottom and the cable holding the two sets (48) passes through them at the end of part (29), a cable puller of wind and lead ward holder cable (49) is installed which determine the degree of looseness and tighten of the cable. The first part (29) has inflatable wheels (51) These wheels are normally completely full of air so that it covers the space inside the first part (29) but the pressure is low. for opening of the mouth of part (29), first the cable holding the two sets (48) is loosened and inflatable wheels (51) inflate and open the mouth of the first part (29) and the second part (43) is guided backwards by the inflatable wheels (51 ) and when the second part reaches the end of its path, the inflatable wheels (51) are slightly empty and the cables holding the two sets (48) tightens. The first part (29), like the front of its part, has a lock (51 A) that goes inside the tab section of the second part, and the inflatable wheels (51), like the previous part, have the task of distribute force throughout the first part (29).
[0032] Figure 11 shows the cable pulling system. For this purpose, one end of the blade pulling cable (52) is installed at the tip of the blade, and inside the root part (31), and rolled around the cable collector (53) and installed in each section as shown. Now, when the tip of blade is toward the ground, the cable, which is installed to the tip of blade, pulls the tip of the blade towards the root and pulls any part that has a free lock into the previous section. When the blade is upwards, the direction of rotation of the collector cable (53) is changed and the return cable, which is connected to the parts by the pulley cable (54), is pulled upwards. In total, four cables are installed to the blade at the same time. Every pair connected to a collector cable (53). Each collector cable (53) is connected to the motor and gearbox (56) by gear (55).
[0033] Figure 12 shows the cable power transmission system from the blades to the generator. A cable system is used for this purpose. The power transmission cables (57) are connected to the teethes (58) and the teethes (58) act like gear teeth. Each of the blades has a transfer power rod (59). Some of the teethes (58) have arm (60). The arm (60) is the power transfer agent from the blade to the cable system. When one of the blades exit of transmission system other blade enter to transmission system This method prevents damage to the blades. The pulley connected to the generator (62) has slots (63) in which the teeth (58) go into the slots and cause the transmission of power from the cables (57) to the generator (62). In this system, there are guiding rollers (64) and base cable system (65), (66) for the installation of the cable system to the tower, and (67) for the guiding rollers.
[0034] Figure 13 shows the vertical force reduction system on the front of the blade. We know that the maximum torque from the vertical force to the root of the blade is due to the vertical force created at the aerodynamic part of the blade. On the other hand, we have only one speed compound under the blade and that is rotational speed. The vertical force reducing blade (68) is installed under the aerodynamic section of the blade, and in this case the lift force is in the opposite direction of the vertical force, and the drag force is in the opposite direction of the horizontal force, which slightly reduces the horizontal force but greatly reduces the vertical force. The torque from the vertical force at the root is reduced, which in turn reduces the weight. (69) is motor for set attack angle of reducer vertical force blade.