An offshore horizontal axis wind turbine generator set

Abstract

The invention discloses an offshore horizontal axis wind turbine generator set. The unit comprises an impeller, a transmission system and a power generation unit. The transmission system is composed of a main shaft, a main bearing and a bearing seat, and there are two bearing seats, each of which corresponds to a group of main bearings. The main shaft is connected to the hub and passes through the inside of the hub. On the front and rear sides of the outside of the hub, the main shaft is connected to two bearing seats through two groups of main bearings respectively. The rotating part of the power generation unit is connected to the main shaft or the hub, and the fixed part thereof is connected to the bearing seat. The unit is connected to at least three pillars, and at least one front pillar and at least two rear pillars are respectively connected to the two bearing seats. The impeller rotates between the front pillar and the rear pillar. The invention replaces the conventional cantilever support of the main shaft and the hub with a simple support, and the connection between the inside of the hub and the main shaft greatly improves the rigidity of the hub. Under the same capacity, the invention makes the unit lighter and has a stronger load-bearing capacity.

Description

Technical Field

[0001] The invention belongs to the technical field of wind power generation, and in particular relates to an offshore horizontal axis wind power generator set. Background Art

[0002] Cost has always been a bottleneck problem in the development of global wind power. Large-scale units (i.e., increased single-unit capacity) have been proven to be the most effective way to solve the cost problem. The continuous development of offshore wind power projects has made large-scale units an inevitable development trend. However, with the increase in unit capacity, the challenges faced by traditional single-impeller wind turbines in the process of capacity upgrade are becoming increasingly severe. The unit load has increased dramatically, and the over-long, over-heavy blades and over-large torque have brought many difficulties to the design, production, manufacturing and installation of various components in the unit (such as variable pitch actuators, support structures, etc.).

[0003] At present, conventional horizontal axis wind turbines, whether offshore or onshore, all use a design in which the impeller (mainly composed of a hub and blades) is located upwind or downwind of the transmission system and tower (the mainstream form is upwind). The common characteristics of this type of design are: the connection between the main shaft and the hub forms a typical cantilever structure; the hub itself adopts a spherical shell structure to transfer the load from the blades to the main shaft. For large and super-large units, the blade load increases sharply due to the use of super-long blades, and multiple blades are almost always in an unbalanced load state during the rotation process, which causes the hub to be severely deformed after being loaded for a long time during the life cycle of the unit.

[0004] In order to increase the rigidity of the hub, the general practice is to reinforce the hub with materials. This method increases the weight of the hub sharply, which in turn increases the burden on components such as the main shaft and main bearing, and the final result is that the economy of the entire unit becomes worse. Summary of the invention

[0005] In view of this, the object of the present invention is to provide an offshore horizontal axis wind turbine generator set, which can meet the demand for increased hub load-bearing capacity after the nacelles of large and super-large wind turbine generator sets use extra-long blades, and transform the cantilever structure connecting the main shaft and the impeller into a simply supported structure, so that the load on the entire transmission system is more reasonable, the weight of the unit is reduced, and the economy of the wind turbine generator set is improved.

[0006] To achieve the above objectives, in a first aspect, an offshore horizontal axis wind turbine generator system comprises an impeller and a transmission system;

[0007] The impeller is composed of a hub and blades, and the root of the blade is connected to the hub;

[0008] The transmission system is composed of a main shaft, a main bearing and a bearing seat, the bearing seat includes a first bearing seat and a second bearing seat, and the main bearing includes a first main bearing and a second main bearing;

[0009] The main shaft is connected to the wheel hub and passes through the interior of the wheel hub;

[0010] The main shaft is connected to the first bearing seat through the first main bearing and to the second bearing seat through the second main bearing on both sides of the main shaft rotation axis outside the hub.

[0011] In a further technical solution, the main shaft is provided with at least one shoulder on both sides of the hub outside along the direction of the main shaft rotation axis, respectively, for axial positioning of the first main bearing and the second main bearing.

[0012] In a further technical solution, the interior of the main shaft is hollow; the main shaft located inside the wheel hub is provided with at least one opening, and the interior of the main shaft is connected with the interior of the wheel hub through the opening.

[0013] The wind turbine generator set also includes a power generation unit, the rotating part of which is connected to one end of the main shaft through a coupling, or connected to the hub through a structural member; the fixed part of the power generation unit is connected to one of the bearing seats.

[0014] In a further technical solution, the first bearing seat is connected to the first nacelle cover through a first nacelle cover frame, and the first nacelle cover surrounds the first bearing seat and the first main bearing therein; the second bearing seat is connected to the second nacelle cover through a second nacelle frame, and the second nacelle cover surrounds the second bearing seat, the second main bearing and the power generation unit therein; the wheel hub is connected to the wheel hub cover through a wheel hub bracket, and the wheel hub cover surrounds the wheel hub therein.

[0015] The offshore wind turbine generator set is connected to at least three pillars, and the pillars include at least one front pillar and at least two rear pillars.

[0016] In a further technical solution, the top of the front support is connected to the first bearing seat, and the top of the rear support is connected to the second bearing seat.

[0017] In a further technical solution, the pitch axis of the blade is perpendicular to the main shaft rotation axis, and the blade rotates between the front strut and the rear strut.

[0018] In a further technical solution, the bottoms of the front pillar and the rear pillar are connected to a floating foundation, a single-point mooring system is provided on the floating foundation, and the wind turbine generator set and the pillar achieve yaw through the floating foundation.

[0019] In a second aspect, an offshore horizontal axis wind turbine generator set is provided, which includes an impeller and a transmission system; the impeller is composed of blades and a hub, and the transmission system is composed of a main shaft, a main bearing and a bearing seat; the main shaft is connected to the hub and passes through the inside of the hub; two bearing seats are arranged on the front and rear sides of the outside of the hub. The main shaft is connected to the two bearing seats through the main bearing.

[0020] In a further technical solution, the offshore wind turbine generator set also includes a power generation unit, the rotating part of the power generation unit is connected to one end of the main shaft through a coupling, or is connected to the hub through a structural member; the fixed part of the power generation unit is connected to the bearing seat.

[0021] In a further technical solution, the interior of the main shaft is hollow; the interior of the main shaft is connected to the interior of the hub through an opening provided on the main shaft.

[0022] In a further technical solution, the offshore wind turbine generator set is connected to at least three pillars, and the tops of the pillars are respectively connected to two of the bearings.

[0023] In a further technical solution, the bottoms of the pillars are connected to a floating foundation, and the wind turbine generator set and the pillars achieve yaw through the floating foundation.

[0024] The beneficial effects of the present invention are as follows: the main shaft of the offshore horizontal axis wind turbine generator set passes through the interior of the hub and is connected to two bearing seats through two sets of main bearings on the front and rear sides of the hub. The conventional main shaft hub cantilever support method is replaced by a simple support method. At the same time, the connection between the hub and the main shaft greatly improves the rigidity of the hub. Compared with conventional design solutions, under the same capacity, the present invention can make the unit lighter and have a stronger load-bearing capacity. It is particularly suitable for the application of large and super-large offshore units. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of an offshore horizontal axis wind turbine generator set according to an embodiment of the present invention;

[0026] Figure 2 A schematic diagram of a transmission system of an offshore horizontal axis wind turbine generator set according to an embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of the connection between the hub and the main shaft of an offshore horizontal axis wind turbine generator set according to an embodiment of the present invention;

[0028] Figure 4 This is a schematic diagram of the connection between an offshore horizontal axis wind turbine generator set and a tower according to an embodiment of the present invention;

[0029] Figure 5 This is a schematic diagram of the positions of blades and the main shaft of an offshore horizontal-axis wind turbine generator set according to an embodiment of the present invention;

[0030] Figure 6 A schematic diagram of the position relationship between blades and a tower of an offshore horizontal-axis wind turbine generator set according to an embodiment of the present invention;

[0031] Figure 7 The present invention is a front view of an offshore horizontal-axis wind turbine generator set according to an embodiment of the present invention.

[0032] Description of Figure Numbers:

[0033] 1. Impeller, 1.1. Hub, 1.2. Blades, 1.201. Pitch axis, 2. Transmission system, 2.1. Main shaft, 2.2. First bearing seat, 2.3. Second bearing seat, 2.101. Main shaft rotation axis, 2.102. Main shaft opening, 2.103. Main shaft front end cover, 2.104. Main shaft front shoulder, 3. Power generation unit, 4. First nacelle cover, 5. Hub cover, 6. Second nacelle cover, 7. Tower, 7.1. Front support, 2.2. Rear support, 8. Floating foundation, 8.1. Floating tank.

[0034] It is worth noting that the above drawings are used to illustrate the features of the present invention, and are not intended to show any actual structure or reflect the size, relative proportions and other detailed information of various components. In order to more clearly show the principles of the present invention and to avoid unnecessary details that make the principles of the present invention unclear, the examples in the figures have been simplified. These illustrations will not cause inconvenience to technicians in the relevant fields in understanding the present invention, and the actual wind turbine generator set may include more components. DETAILED DESCRIPTION

[0035] In order to make the purpose and technical solution of the embodiment of the present invention clearer, the embodiment of the present invention is fully described below in conjunction with the relevant drawings of the embodiment of the present invention. This patent describes only a part of the embodiments, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0036] like Figure 1 and Figure 2 As shown, the offshore horizontal axis wind turbine generator set mainly includes an impeller 1, a transmission system 2 and a power generation unit 3. These three parts are the most core and indispensable parts of the wind turbine generator set, and they constitute what is commonly known as the "head". In general wind power project bidding, a considerable part of the bidding price is calculated according to the "head" price.

[0037] The impeller 1 is composed of a hub 1.1 and blades 1.2, and the roots of the blades 1.2 are connected to the hub 1.1 through pitch bearings.

[0038] like Figure 3 As shown, the transmission system 2 is composed of a main shaft 2.1, a main bearing and a bearing seat, the bearing seat includes a first bearing seat 2.2 and a second bearing seat 2.3, and each bearing seat is connected to the main shaft through a main bearing.

[0039] The main shaft 2.1 is connected to the hub 1.1. Usually, the main shaft and hub of large and super large units (generally referring to units with a single unit capacity of more than 10MW) are connected by bolts. In some embodiments, the main shaft 2.1 and the hub 1.1 can be made together by casting. The main shaft 2.1 runs through the inside of the hub 1.1, and the two ends of the main shaft 2.1 are respectively located outside the hub 1.1.

[0040] The main shaft 1.1 is connected to the first bearing seat 2.2 and the second bearing seat 2.3 through the two sets of main bearings on the front and rear sides of the outside of the hub (the direction along the main shaft rotation axis 2.101 is defined as the "front and rear direction"), respectively.

[0041] The rotating part of the power generation unit 3 (including a gearbox and a generator in some embodiments) refers to the input shaft of the gearbox in some embodiments, which is also a low-speed shaft, and the low-speed shaft is connected to one end of the main shaft 2.1 through a coupling. The fixed part of the power generation unit 3 refers to the housing of the gearbox in some embodiments, which is connected to the second bearing seat 2.3.

[0042] The characteristics and novelty of the above technical solution are: the main shaft and the hub of the conventional wind turbine generator set adopt a split structure and are connected by bolts on the outside of the hub, so that the main shaft and the hub form a cantilever support structure. In the present invention, the main shaft 2.1 passes through the inside of the hub 1.1 and is connected to the bearing seats 2.2 and 2.3 on the front and rear sides of the hub 1.1, forming a simple support for the hub 1.1 (also known as the impeller 1).

[0043] The benefits of the above technical solution are: the transmission system load-bearing mode of the simple support structure is more reasonable, and the rigidity of the hub is increased by using the through-type connection between the main shaft and the hub. For large and super-large units using extra-long blades, it can better adapt to the greatly increased blade root load, and the weight of the hub itself, the main shaft, the bearing seat and other parts can be controlled, thereby reducing the manufacturing, transportation and installation costs of the unit.

[0044] The main shaft 2.1 is located at both ends of the outside of the hub 1.1 and is provided with a shaft shoulder. Figure 3As shown, the front shoulder 2.104 is located near the connection part between the front of the hub 1.1 and the main shaft 2.1. In some embodiments, the front end of the main shaft 2.1 is provided with a front cover 2.103. The front shoulder 2.104 and the front cover 2.103 jointly realize the positioning of the main bearing along the main shaft rotation axis 2.101 to prevent the main bearing from moving. The front cover 2.103 needs to be set as a detachable connection. During the assembly process, the main bearing is first installed on the main shaft 2.1, and then the front cover 2.103 is installed.

[0045] like Figure 2 and Figure 3 As shown, in some embodiments, the portion of the main shaft 2.1 located inside the hub 1.1 is provided with a plurality of openings 2.102. After the blades 1.2 are connected to the hub 1.1, the openings 2.102 are the only way to enter the hub 1.1. The size of the openings 2.102 is adapted to the size of the maintenance personnel and the parts of the pitch actuator, and its main function is to provide a maintenance channel.

[0046] like Figure 1 As shown, the first nacelle cover 4 is fixed to the first bearing seat 2.2 through the first nacelle cover bracket, and the second nacelle cover 6 is fixed to the second bearing seat 2.3 through the nacelle frame. The first nacelle cover 4 and the second nacelle cover 6 respectively wrap the part of the main shaft 2.1 located outside the hub 1.1 inside. In some embodiments, the power generation unit 3 can be placed inside the second nacelle cover 6 at the same time, or a protective cover of the power generation unit itself can be set separately, and then connected to the second nacelle cover 6 by bolts. For large units, the latter is more likely because the size and weight of the power generation unit 3 require separate transportation and assembly.

[0047] The hub cover 5 is fixed to the hub 1.1 through the hub bracket. The hub cover 5 surrounds the hub 1.1 inside. In addition, in some embodiments, the connection between the root of the blade 1.2 and the hub 1.1, including the pitch bearing, etc., are all located inside the hub cover 5. Since the hub cover 5 is in a rotating state relative to the first nacelle cover 4 and the second nacelle cover 6 most of the time, seals are provided in front and behind the hub cover to prevent dust and rainwater from entering the interior of the cabin. A space through which maintenance personnel can pass is formed between the interior of the hub cover 5 and the exterior of the hub 1.1, and personnel located inside the first nacelle cover 4 can enter the interior of the second nacelle cover 6 through the interior of the hub cover 5.

[0048] like Figure 4 As shown, in some embodiments, the tower 7 of the wind turbine generator set includes three pillars, namely a front pillar 7.1 and two rear pillars 7.2.

[0049] The bottom of the first bearing seat 2.2 and the bottom of the second bearing seat 2.3 are both provided with a mechanical interface connected to the tower 7, which can be compared to the base of a conventional wind turbine. The difference is that the connection between the first bearing seat 2.2 and the second bearing seat 2.3 and the tower 7 is a rigid connection, because no yaw support is provided at the connection position. In some embodiments, the front support 7.1 and the rear support 7.2 both adopt a steel cylindrical structure, and maintenance personnel can enter the interior of the hub cover 5 and the second nacelle cover 6 from the bottom of the first bearing seat 2.2 and the second bearing seat 2.3 through a ladder or other device provided therein. At the same time, the power cables and other lines output by the power generation unit 3 can reach the bottom of the tower 7 through the rear support 7.2.

[0050] like Figure 5 As shown, the blade pitch axis 1.201 is perpendicular to the main shaft rotation axis 2.101, and the two lines intersect in theory. In other words, the blade 1.2 has no cone angle relative to the hub 1.1, or the cone angle can be equivalently considered to be 0. This is significantly different from conventional wind turbines. Conventional super-long blades do not have interference problems in front, and the cone angle of the blade can be increased to increase the clearance between the loaded blade and the tower, thereby reducing the probability of interference between the blade and the tower.

[0051] like Figure 6 As shown, in the solution of the present invention, the blade 1.2 rotates between the front support 7.1 and the rear support 7.2. If a cone angle is set, the front support 7.1 needs to be set at a large inclination angle to avoid interference, which is unreasonable for the front support 7.1 that mainly bears the gravity load. Another benefit of not setting a cone angle is that the swept area of ​​the impeller is not reduced due to the cone angle, thereby improving the unit's ability to capture wind and generate electricity. In order to avoid interference between the rear support 7.2 and the deformed blade 1.2 under load, in some embodiments, the rear support 7.2 mainly bears gravity and the thrust load from the impeller, and it needs to be set at a larger inclination angle than the front support 7.1.

[0052] like Figure 7 As shown, the bottom of the front support 7.1 and the rear support 7.2 are both connected to the floating foundation 8. Due to the simple support structure adopted in the present invention, the impeller rotates between the front support 7.1 and the rear support 7.2. Therefore, the top of the front support 7.1 and the rear support 7.2 connected to the first bearing seat 2.2 and the second bearing seat 2.3 cannot achieve yaw. Yaw can only be achieved through the floating foundation 8. Since the front support 7.1 and the rear support 7.2 must be connected to multiple pontoons 8.1 of the floating foundation 8, the floating foundation 8 needs to adopt a single-point mooring system to achieve yaw rotation.

[0053] In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper, lower, left, right, front, rear, inside, outside and both sides" are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first, second or third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0054] In the present invention, unless otherwise clearly specified and limited, the terms "install, connect, connect, and couple" should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection, or an integral connection; it can also be a mechanical connection, an electrical connection, or a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0055] Although the present invention has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced by equivalents without departing from the scope of the present invention. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. An offshore horizontal axis wind turbine generator set, characterized in that: The wind turbine generator set comprises an impeller and a transmission system; the impeller is composed of a hub and blades, and the root of the blade is connected to the hub; The transmission system is composed of a main shaft, a main bearing and a bearing seat, wherein the bearing seat at least includes a first bearing seat and a second bearing seat, and the main bearing includes a first main bearing and a second main bearing; The main shaft is connected to the wheel hub and passes through the interior of the wheel hub; The main shaft is connected to the first bearing seat through the first main bearing and connected to the second bearing seat through the second main bearing on both sides of the main shaft rotation axis outside the hub; The wind turbine generator set further comprises a power generation unit, the rotating part of which is connected to one end of the main shaft via a coupling; The wind turbine generator set is connected to at least three pillars, wherein the pillars include at least one front pillar and at least two rear pillars; the top end of the front pillar is connected to the first bearing seat, and the top end of the rear pillar is connected to the second bearing seat; The rear support pillar is provided with a greater inclination angle than the front support pillar.

2. The offshore horizontal axis wind turbine generator set according to claim 1, characterized in that: The main shaft is provided with at least one shaft shoulder on both sides of the hub outside along the direction of the main shaft rotation axis, respectively, for axial positioning of the first main bearing and the second main bearing.

3. The offshore horizontal axis wind turbine generator set according to claim 1, characterized in that: The interior of the main shaft is hollow; the main shaft located inside the wheel hub is provided with at least one opening, and the interior of the main shaft is connected with the interior of the wheel hub through the opening.

4. The offshore horizontal axis wind turbine generator set according to claim 1, characterized in that: The fixed part of the power generation unit is connected to one of the bearing seats.

5. The offshore horizontal axis wind turbine generator set according to claim 4, characterized in that: The first bearing seat is connected to the first nacelle cover through a first nacelle cover frame, and the first nacelle cover surrounds the first bearing seat and the first main bearing therein; The second bearing seat is connected to the second nacelle cover through a second nacelle frame, and the second nacelle cover surrounds the second bearing seat, the second main bearing and the power generation unit therein; The wheel hub is connected to a hub cover via a wheel hub bracket, and the hub cover surrounds the wheel hub inside.

6. The offshore horizontal axis wind turbine generator set according to claim 1, characterized in that: The pitch axis of the blade is perpendicular to the main shaft rotation axis, and the blade rotates between the front strut and the rear strut.

7. The offshore horizontal axis wind turbine generator set according to claim 1, characterized in that: The bottom ends of the front support and the rear support are both connected to a floating foundation, and the wind turbine generator set and the support achieve yaw through the floating foundation.

8. An offshore horizontal axis wind turbine generator set, characterized in that: include: Impeller and drive train; The impeller is composed of blades and a hub, and the transmission system is composed of a main shaft, a main bearing and a bearing seat; the main shaft is connected to the hub and passes through the interior of the hub; two bearing seats are arranged on the front and rear sides of the outside of the hub; the main shaft is connected to the two bearing seats through the main bearing; the wind turbine generator set also includes a power generation unit, and the rotating part of the power generation unit is connected to one end of the main shaft through a coupling; the wind turbine generator set is connected to at least three pillars, and the pillars include at least one front pillar and at least two rear pillars; the top end of the front pillar and the top end of the rear pillar are respectively connected to the two bearing seats; the rear pillar is set with a larger inclination angle than the front pillar.

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