A variable-pitch sea wave power plant and a variable-pitch sea wave power method

Abstract

The application discloses a variable-pitch sea wave power generation device and a variable-pitch sea wave power generation method, which comprise a blade wheel and a variable-pitch control system, the blade wheel rotates around a vertical axis, the blade wheel comprises a plurality of blade units which are distributed in a diverging manner from the center of the blade wheel to the outside, and the blades extend in a radial direction, and the variable-pitch control system can control the blades to rotate along a horizontal axis to change the pitch. The energy transmission steps of the scheme are few, energy loss can be reduced, and energy utilization rate can be improved; the pitch angle of the blades can be adjusted according to different sea wave characteristics, so that the optimal power generation efficiency under corresponding sea wave conditions can be obtained; and the scheme also has a constant power characteristic, so that the stable output of the power generation of the unit can be ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power generation, in particular to a variable-pitch sea wave power generation device and a variable-pitch sea wave power generation method. BACKGROUND

[0002] The sea wave energy is large in storage amount and is not easily affected by weather, and the collection and conversion of the sea wave energy have attracted attention from all walks of life. However, the traditional sea wave power generation system has the following disadvantages:

[0003] The traditional sea wave power generation device needs to convert the kinetic energy of the flowing direction of the sea wave into the kinetic energy of the piston of the hydraulic cylinder first, and then uses compressed air to drive the turbine of the generator to move, so as to generate electric energy. This system has multiple kinetic energy transmission and conversion, and the energy loss is large, and the power generation efficiency is low.

[0004] In addition, the sea wave force structure size and shape of the traditional sea wave power generation device are fixed, and can only be applied to a small range of sea wave characteristics, such as wavelength, wave height, period, etc. The sea wave is complex and variable, and its characteristic parameters are also constantly changing. When the wave parameter exceeds the applicable range of the traditional sea wave power generation system, the power generation efficiency will be greatly reduced, resulting in poor overall power generation performance and low overall power. SUMMARY

[0005] The present application provides a variable-pitch sea wave power generation device, comprising an impeller and a variable-pitch control system, the impeller rotates around a vertical axis, the impeller comprises a plurality of blade units distributed in a diverging manner from the center of the impeller, and the variable-pitch control system can control the rotation of the blade units along the horizontal axis to change the pitch.

[0006] In a specific embodiment, each blade unit comprises at least one blade arranged along the radial direction of the impeller.

[0007] In a specific embodiment, the impeller comprises a middle base, the blade units comprise a support rod extending in the radial direction, one end of the support rod is fixed to the middle base, and the blades of the blade units are arranged along the length direction of the support rod.

[0008] In a specific embodiment, it further comprises a plurality of annular support frames, each annular support frame is arranged around the middle base, and each annular support frame is sequentially distributed from inside to outside; each support rod is connected with a plurality of annular support frames.

[0009] In a specific embodiment, it further comprises a total base and at least two impellers, all the impellers are arranged around the total base, and the impellers are connected with the total base through a connecting frame.

[0010] In an embodiment, the connecting frame comprises a ring-shaped frame and at least two connecting rods, the middle bases of the plurality of impellers are connected to the ring-shaped frame, and the two ends of the connecting rods are connected to the ring-shaped frame and the general base respectively.

[0011] In an embodiment, the general base and the middle base are floating bases or fixed bases.

[0012] In an embodiment, the pitch control system comprises a plurality of pitch execution units, and each of the blades is provided with a corresponding pitch execution unit.

[0013] The application also provides a pitch-type sea wave power generation method, based on the pitch-type sea wave power generation device described in any one of the above embodiments, when the generated power is less than the rated power, all the blades are controlled to be pitched to the maximum position; when the generated power is about to exceed the rated power, the pitch angles of part or all of the blades are controlled to reduce the generated power until the generated power approaches the rated power.

[0014] The pitch-type sea wave power generation device has the following advantages:

[0015] 1. The energy of the up and down movements of the sea waves is directly used to drive the impellers and the turbine generators to rotate for power generation, the number of energy transmission steps is reduced, the energy loss is reduced, and the energy utilization rate is improved.

[0016] 2. Since the blades on the impellers have the pitch function, the pitch angles of the blades can be adjusted according to different sea wave characteristics to obtain the optimal power generation efficiency under the corresponding sea wave conditions. Therefore, the pitch-type sea wave power generation device has stronger applicability and can be applied to a wider range of waves.

[0017] 3. The pitch-type sea wave power generation device can also have constant power characteristics due to the pitch control system, which can ensure stable output of the generated power of the unit, and has stronger grid friendliness.

[0018] As a further scheme, each blade unit comprises two or more blades arranged in a radial direction, and the number and size of the blades in each blade unit can be customized according to the project site. For example, the length of the blades can be designed according to the wave characteristics of the application sea area, such as the usual wavelength range, combined with the airfoil characteristics of the blades, to design a reasonable blade length to minimize the influence of the opposite directions of the up and down wave fluctuations on the energy collection of the blades, and the number of blades arranged in each blade unit can be calculated and designed according to the power generation demand, so as to obtain the optimal overall power and efficiency, solve the contradiction between power generation efficiency and power generation power, and make the scheme have stronger expansibility and applicability. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1This is a schematic diagram of the structure of the variable pitch wave power generation device in the first embodiment of the present invention;

[0020] Figure 2 for Figure 1 A schematic diagram of the structure of a single blade;

[0021] Figure 3 For Figure 2 A schematic diagram analyzing the stress characteristics of a blade based on its cross-section;

[0022] Figure 4 This is a schematic diagram of the structure of the variable pitch wave power generation device in the second embodiment of the present invention;

[0023] Figure 5 for Figure 4 A schematic diagram of the state of the middle blade after propeller retraction;

[0024] Figure 6 This is a schematic diagram of the structure of the variable pitch wave power generation device in the third embodiment of the present invention.

[0025] Figures 1-6 The annotations in the attached figures are explained as follows:

[0026] 1-Impeller;

[0027] 11-Turbine generator; 12-Central foundation; 13-Blade; 131-Pitch actuator; 13a-Section section; 14-Support rod; 15-Annular support frame;

[0028] 2-General Foundation;

[0029] 3-Connecting rod;

[0030] 4-Ring frame. Detailed Implementation

[0031] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of the variable pitch wave power generation device in the first embodiment of the present invention.

[0033] The pitch-type wave generator includes a horizontally rotating impeller 1 and a pitch control system. Horizontal rotation refers to rotation within a horizontal plane. Figure 1 This is a top view of the impeller 1. Specifically, the impeller 1 includes a plurality of blade units distributed outward from the center of the impeller 1, and each blade unit includes at least one blade 13 arranged radially along the impeller 1. Figure 1Each blade unit comprises two blades 13, which also extend in the radial direction of the impeller 1. The blades 13 can be made of steel or composite materials.

[0034] The pitch control system can control the blades 13 to rotate along the horizontal axis to pitch. After the blades 13 are pitched, the impeller 1 can be driven to rotate under the up-and-down fluctuation of the sea waves, so as to collect and convert the up-and-down fluctuation energy of the sea waves, drive the turbine generator 11 of the pitch-controlled sea wave power generation device to generate electricity, and the turbine generator 11 is connected to the middle part of the impeller 1.

[0035] The principle that the blades 13 are stressed to drive the impeller 1 to rotate under the up-and-down fluctuation of the sea waves can be further referred to Figures 2-3 understand, Figure 2 for Figure 1 a structural schematic view of a single blade 13; Figure 3 is based on Figure 2 a schematic view of the stress characteristics of the blade 13 based on the blade section 13a.

[0036] As shown in Figure 3 , the impeller 1 plane of the impeller 1 is also a horizontal plane in this embodiment, the blades 13 are pitched to rotate around the horizontal axis, Figure 3 the horizontal axis is perpendicular to the paper surface and intersects at point O. Among them, the included angle between the impeller 1 plane and the chord line of the blade 13 is the pitch angle, the resultant velocity Vres formed by the water particle velocity U generated by the up-and-down fluctuation of the sea waves and the rotational speed Ωr of the impeller 1, the included angle between the impeller 1 plane and the resultant velocity Vres is the inflow angle, and the included angle between the chord line and the resultant velocity Vres is the attack angle. The resultant velocity Vres acts on the blade 13 to generate lift L and drag D, which can generate a resultant force R on the blade 13. The resultant force R can be decomposed into a normal force Fn perpendicular to the impeller 1 plane and a tangential force Ft along the impeller 1 plane, and the tangential force Ft can generate a torque to rotate the impeller 1. The combined torque of multiple blades 13 can drive the impeller 1 to rotate, thereby driving the turbine generator 11 to generate electricity. The principle that the blades 13 push the impeller 1 to rotate under external force can refer to the rotating principle of the existing wind turbine impeller 1, and will not be expanded in more detail.

[0037] The pitch-controlled sea wave power generation device has the following advantages:

[0038] 1. Directly use the energy of the up-and-down movement of the sea waves to drive the impeller 1 and the turbine generator 11 to rotate to generate electricity, the energy transmission steps are less, the energy loss can be reduced, and the energy utilization rate can be improved.

[0039] 2、Due to the variable pitch function of the blades 13 on the impeller 1, the blades 13 can adjust their pitch angles according to different sea wave characteristics to obtain the optimal power generation efficiency under the corresponding sea wave conditions. Therefore, the variable pitch sea wave power generation device has stronger applicability and can be applied to a wider range of waves.

[0040] 3、More importantly, each blade unit in the present scheme can include two or more blades 13 arranged in the radial direction, i.e., each blade unit is composed of multiple small blades. The impeller 1 of the present scheme is mainly used to collect the up and down fluctuation energy of sea waves. If the length of the blades 13 in the direction of the impeller 1 is too long, such as being roughly equivalent to the wavelength of sea wave fluctuation, there may be partial cancellation due to the difference in the directions of up and down fluctuation, affecting the collection efficiency. In the present scheme, the blade unit is divided into multiple blades 13, and the number and size of the blades 13 in each blade unit can be customized according to the project site. For example, the length of the blades 13 can be designed more reasonably according to the wave characteristics of the application sea area, such as the usual wavelength range, combined with the airfoil characteristics of the blades 13 themselves, to minimize the impact of the opposite directions of up and down fluctuation on the energy collection of the blades 13, and the number of blades 13 arranged in each blade unit can be calculated and designed according to the requirements, so as to obtain the optimal overall power and efficiency, and solve the contradiction between power generation efficiency and power generation power.

[0041] Figure 1 Each blade unit of the impeller 1 shown includes two blades 13. Obviously, the number is not limited to this, such as Figure 4 as shown, Figure 4 the structure diagram of the variable pitch sea wave power generation device in the second embodiment of the present application, each blade unit includes four blades 13.

[0042] It can be understood that through experiments or dynamic simulation, reasonable design of the airfoil of the blades 13 can be realized, so that the up and down fluctuations of sea waves can generate moments that make the impeller 1 rotate in the same direction on the blades 13, but the airfoil design focusing on energy collection in one direction can improve the utilization rate of sea wave energy.

[0043] As can be seen, since the blade unit is composed of multiple blades 13 in the present scheme, the present scheme has stronger expansibility and applicability.

[0044] 4、The variable pitch sea wave power generation device can also have a constant power characteristic, which can ensure stable output of the unit power generation power and has stronger grid friendliness.

[0045] The stable output of the power generation power can be realized through a variable pitch control system, as follows:

[0046] The rated power can be set according to different requirements, and when the power generation power does not exceed the rated power, the control is performed to open the blades 13 of all the blade units to the maximum; at this time, the sea wave is generally small;

[0047] When the sea wave becomes large and the power generation power reaches the rated power and has a tendency to exceed the rated power, the pitch angle of part or all of the blades 13 can be adjusted by the pitch control system to reduce the torque of part or all of the blades 13, so that the power generation power is reduced until it approaches the rated power. Thus, the variable-pitch sea wave power generation device has a constant power characteristic. Adjusting the pitch angle of part of the blades also includes directly adjusting to control part of the blades 13 to be closed, such as Figure 5 as shown in Figure 5 Fig. 4, Figure 4 which is a schematic view of the state of the middle blade 13 after being closed.

[0048] The pitch control system in the present scheme includes a plurality of pitch execution units 131, and each blade 13 is provided with a corresponding pitch execution unit 131, that is, each blade 13 in each blade unit is also independently controlled, so that independent pitch control can be performed on all the blades 13, and the adjustment is performed according to the constant power requirement.

[0049] In the present scheme, if the sea wave is too large, the blades 13 of the variable-pitch sea wave power generation device may be damaged due to excessive force if they are opened, so when the sea wave is too large, the pitch control system can directly control all the blades 13 to be closed to protect the safety of the device.

[0050] Please continue to refer to Figure 1 , the impeller 1 can include a middle base 12, and the blade unit further includes a support rod 14 extending in the radial direction, one end of the support rod 14 being fixed to the middle base 12, and each blade 13 of the blade unit being arranged along the length direction of the support rod 14. In this way, the support rod 14 can provide stable and reliable support for each blade 13 in the corresponding blade unit, and the structure design is simple. It can be seen that each blade 13 of the blade unit is not limited to being connected to the middle base 12 through the support rod 14, for example, each blade 13 can be connected to the middle base 12 through a separate connection structure.

[0051] Figure 1 In the present scheme, the impeller 1 further includes a plurality of annular support frames 15, each annular support frame 15 being separately arranged around the middle base 12, and the plurality of annular support frames 15 being sequentially distributed from inside to outside, that is, sequentially arranged in a direction away from the middle base 12, and the annular size gradually increasing. Each support rod 14 is connected to the plurality of annular support frames 15, that is, the plurality of support rods 14 are simultaneously connected to the plurality of annular support frames 15, so as to form a rigid support frame structure similar to a grid, thereby enabling the blade units to be more reliably assembled together and improving the stability of the structure. Figure 1The plurality of annular support frames 15 are arranged concentrically with the impeller 1 in a circular ring shape, but obviously, the annular support frames 15 herein are not limited to Figure 1 The circular ring shape shown in the above embodiment can be a circular ring shape as shown in the above embodiment, or can be other shapes such as a square shape, as long as the plurality of support rods 14 can be connected in series and the fixing reliability is improved.

[0052] The above-mentioned middle foundation 12 can be a floating foundation or a fixed foundation, and the floating foundation can better adapt to the sea waves, and the fixed foundation has a relatively stable position, and can be selected according to specific application environments and application requirements.

[0053] Please continue to refer to Figure 6 , Figure 6 FIG. 3 is a structural schematic diagram of a variable-pitch sea wave power generation device according to a third embodiment of the present application.

[0054] The variable-pitch sea wave power generation device in the embodiment is not limited to being provided with only one impeller 1 as described above, Figure 6 The variable-pitch sea wave power generation device further includes a general foundation 2 and at least two impellers 1 as described in the above embodiments, and all the impellers 1 are arranged around the general foundation 2, and all the impellers 1 are connected to the general foundation 2 through a rigid connecting frame, so that the plurality of impellers 1 can be arranged in a certain sea area, and the up-and-down wave energy of the sea waves in the sea area with relatively consistent sea wave characteristic parameters can be better collected, and the electric energy generated by the plurality of impellers 1 can be conveniently collected, Figure 6 Four impellers 1 around the general foundation 2 are shown in the above embodiment, but obviously, the number of impellers 1 in the present solution is not limited.

[0055] Specifically, the connecting frame can include an annular frame 4 and at least two connecting rods 3, and the middle foundations 12 of the plurality of impellers 1 are respectively connected to the annular frame 4, that is, the annular frame 4 connects the plurality of impellers 1 in series on one annular frame 4, and the annular frame 4 can be Figure 6 The connecting rods 3 in the connecting frame are respectively connected to the annular frame 4 and the general foundation 2 at both ends, so that the connecting rods 3 form a skeleton structure to connect the annular frame 4 and the general foundation 2 and improve the strength of the entire connecting frame.

[0056] In addition, the general foundation 2 can be a floating foundation or a fixed foundation, and can be selected according to specific application environments and application requirements, which is the same as the middle foundation 12 of the single impeller 1 described above.

[0057] The principles and implementation manners of the present application are described by using specific examples in the present application, and the above embodiment is only used to help understand the method of the present application and its core idea. It should be pointed out that, for ordinary skilled persons in the technical field, some improvements and modifications can be made to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A pitch-type wave power generation device, characterized in that, The device includes an impeller (1) and a pitch control system. The impeller (1) rotates about a vertical axis. The impeller (1) includes a plurality of blade units that are distributed outward from the center of the impeller (1) and the blade units extend radially. The pitch control system can control the blade units to rotate along a horizontal axis to change the pitch. Each blade unit includes at least one blade (13) arranged radially along the impeller (1); the pitch control system includes a plurality of pitch actuators (131), and each blade (13) is provided with a corresponding pitch actuator (131); When the power generation does not exceed the rated power, the pitch control system controls all the blades (13) to open to the maximum position; when the power generation is about to exceed the rated power, the pitch control system controls the pitch angle of some or all of the blades (13) to reduce the power generation until it approaches the rated power. The impeller (1) includes a central base (12), the blade unit includes a radially extending support rod (14), one end of the support rod (14) is fixed to the central base (12), and each blade (13) of the blade unit is arranged along the length direction of the support rod (14). It also includes multiple ring support frames (15), each of which is arranged around the central foundation (12) and is distributed from the inside to the outside; each of the support rods (14) is connected to multiple ring support frames (15); It also includes a main base (2) and at least two impellers (1), all of which are arranged around the main base (2) and are connected to the main base (2) by a connecting frame; The connecting frame includes an annular frame (4) and at least two connecting rods (3), and the central bases (12) of the multiple impellers (1) are all connected to the annular frame (4); the two ends of the connecting rods (3) are respectively connected to the annular frame (4) and the main base (2).

2. The pitch-type wave generator as described in claim 1, characterized in that, The main foundation (2) and the central foundation (12) are either floating foundations or fixed foundations.

3. A pitch-type wave power generation method, based on the pitch-type wave power generation device according to any one of claims 1-2, characterized in that, When the power generation does not exceed the rated power, control all the blades (13) to open to the maximum position; when the power generation is about to exceed the rated power, control the pitch angle of some or all of the blades (13) to reduce the power generation until it approaches the rated power.

Images