Multi-energy complementary system under wind wave and flow combined load

Abstract

The invention discloses a multi-energy complementation system under wind wave and flow combined load, and belongs to the technical field of ocean energy utilization, the system comprises a multi-energy complementation space array configuration composed of a plurality of wind turbines, a plurality of wave energy floaters and a plurality of tidal turbines, and the wind turbines, the wave energy floaters and the tidal turbines are arranged in the multi-energy complementation space array configuration. The wave energy floaters are coupled with the wind turbines, the multi-energy complementary space array configuration comprises a plurality of wind turbines, the wave energy floaters and the tide turbines which are arranged on the same Y axis, and the Y axes extend and are arranged at equal intervals along the X axis; according to the system, wave energy and wind energy on the sea surface can be fully utilized for outputting electric energy, meanwhile, coupling of the wind turbine and the wave energy floater is utilized, the wave height of the wave energy floater can be increased in the placement process of the tidal turbine, and then the generating capacity is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of marine energy utilization, and in particular relates to a multi-energy complementary system under the combined load of wind, waves and currents. Background Art

[0002] Power supply for offshore islands is of great significance and has considerable challenges. Island areas have abundant marine energy resources, including wind energy, solar energy, wave energy and tidal energy, but offshore islands still face the challenge of insufficient energy supply. Although various marine energy collection devices have been developed, in the existing limited research, different types of energy are collected and utilized by different devices. Therefore, it is necessary to further study the integration of multiple energy sources in a complementary system for simultaneous utilization. Based on the power supply of wave energy floats, the inventors combined wind energy and tidal energy to design a joint system for the complementary utilization of multiple energies. Summary of the invention

[0003] The purpose of the present invention is to provide a multi-energy complementary system under the combined load of wind, waves and currents, which can fully utilize the wave energy and wind energy on the sea surface to output electrical energy, and at the same time utilize the coupling of wind turbines and wave energy buoys. During the placement of tidal turbines, the wave height at the wave energy buoy can be increased, thereby increasing the power generation.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A multi-energy complementary system under the combined load of wind, wave and current includes a multi-energy complementary space array configuration composed of a wind turbine, a wave energy buoy and a tidal turbine. The wind turbine, the wave energy buoy and the tidal turbine are each provided with a plurality of wave energy buoys coupled with the wind turbine. The multi-energy complementary space array configuration includes a plurality of the wind turbines, the wave energy buoys and the tidal turbines on the same Y axis, and the plurality of Y axes are arranged and extended at equal intervals along the X axis.

[0006] The multi-energy complementary system in the present application is a constructed multi-energy complementary space array configuration. The multi-energy complementary space array configuration constructed as described above can be used to enhance the efficiency of offshore renewable energy collection. The offshore mainly includes wind energy, wave energy and tidal energy (flow), which interfere with each other at sea. The present application discloses a related multi-energy complementary space array configuration, in which placing three tidal turbines between the upstream and downstream wind turbines is the optimal way, which can increase the wave height of the downstream wave energy converter (WEC) and increase the wave energy without affecting the energy utilization efficiency of the WEC. Therefore, the multi-energy complementary space array configuration of the present application can improve the utilization efficiency.

[0007] Furthermore, the multi-energy complementary space array configuration provided by the present invention is mainly composed of various devices, and the specific difference in the array lies in the placement position and placement spacing, and claim 2 discloses the relevant position relationship and spacing characteristics, which are therefore necessary features of the multi-energy complementary space array configuration.

[0008] As a preferred solution of the present invention, a wind turbine is placed at both ends and the center position along the Y axis respectively, the two ends of the Y axis are the upstream and downstream positions respectively, and a plurality of tidal turbines are placed between the two wind turbines, and the plurality of tidal turbines are arranged equidistantly.

[0009] As a preferred solution of the present invention, the distance between the wind turbine and the tidal turbine is L1, the distance between two tidal turbines is L2, and the distance between two Y axes is L3.

[0010] As a preferred solution of the present invention, L1=3D~5D, L2=1D~3D, L3=3D~5D, wherein D=1.25m.

[0011] As a preferred solution of the present invention, a preferred solution of the multi-energy complementary spatial array configuration is to arrange a plurality of wind turbines on each Y axis, three tidal turbines are arranged between two wind turbines, and the three tidal turbines are arranged equidistantly.

[0012] The beneficial effects of the present invention are:

[0013] 1. The system provides a feasible multi-energy complementary array structure, which integrates wind turbines, tidal turbines and wave energy floats, and can fully utilize the wave energy and wind energy on the sea surface to output electrical energy. At the same time, by utilizing the coupling between wind turbines and wave energy floats, the wave height at the wave energy float can be increased during the placement of tidal turbines, thereby increasing the power generation. At the same time, the array parameters are determined in combination with the actual external ocean environment, reducing interference between devices, and obtaining an optimized and reasonable multi-energy complementary array structure;

[0014] 2. Wind, waves and tides are abundant energies on the sea surface and are in a state of mutual interference on the sea surface. Through the multi-energy complementary array structure of the present application, the wind turbines arranged upstream inside the array structure can affect the wave height, thereby affecting the energy conversion efficiency of the wave energy float. At the same time, the upstream turbine causes additional wind speed attenuation in the lateral direction of the wind turbine line, thereby affecting the downstream wind turbines and further affecting the power generation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of the multi-energy complementary space array of the multi-energy complementary system under the combined load of wind, wave and current provided by the present invention;

[0016] Figure 2 It is a linear relationship diagram of wind speed attenuation of the multi-energy complementary system under the combined load of wind, wave and current provided by the present invention with and without upstream wind turbines at a wind speed of 2.28 m / s;

[0017] Figure 3 It is a linear relationship diagram of wind speed attenuation of the multi-energy complementary system under the combined load of wind, wave and current provided by the present invention with and without upstream wind turbines at a wind speed of 1.6 m / s;

[0018] Figure 4 It is a linear relationship diagram of wind speed attenuation of the multi-energy complementary system under the combined load of wind, wave and current provided by the present invention with and without upstream wind turbines at a wind speed of 1.2 m / s;

[0019] Figure 5 It is a linear relationship diagram of lateral wind speed attenuation of the multi-energy complementary system under wind, wave and current combined load provided by the present invention with and without upstream wind turbines at a wind speed of 2.28 m / s;

[0020] Figure 6 It is a linear relationship diagram of lateral wind speed attenuation of the multi-energy complementary system under wind, wave and current combined load provided by the present invention with and without upstream wind turbines at a wind speed of 1.6 m / s;

[0021] Figure 7 It is a linear relationship diagram of lateral wind speed attenuation of the multi-energy complementary system under the combined load of wind, wave and current provided by the present invention with and without upstream wind turbines at a wind speed of 1.2 m / s. DETAILED DESCRIPTION

[0022] In order to further understand the content, features and effects of the present invention, the following embodiments are given as examples and described in detail with reference to the accompanying drawings.

[0023] Please also refer to Figures 1 to 3 The following will describe in detail the multi-energy complementary system under the combined load of wind, waves and currents according to an embodiment of the present invention in conjunction with the accompanying drawings.

[0024] like Figure 1 As shown, the multi-energy complementary system under the combined load of wind, wave and current includes a multi-energy complementary space array configuration composed of wind turbines, wave energy buoys and tidal turbines, and the wind turbines, wave energy buoys and tidal turbines are each provided with a plurality of the wave energy buoys and the wind turbines are coupled, and the multi-energy complementary space array configuration includes a plurality of the wind turbines, the wave energy buoys and the tidal turbines on the same Y axis, and the plurality of Y axes are arranged and extended at equal intervals along the X axis.

[0025] Among them, in this embodiment, the hub diameter of the specific wind turbine is 8 cm, the rotor diameter is 125.6 cm, the tower of the wind turbine is made of steel structure, the shell is 3D printed with acrylonitrile butadiene styrene, the wave energy buoy adopts an annular wave energy converter, the wave energy buoy is 3D printed with acrylonitrile butadiene styrene, and the surface is coated with waterproof coating, the diameter of the tidal turbine is 20 cm, the hub diameter is 3.82 cm, the root chord length of the blade of the tidal turbine is 3.82 cm, the tip chord length is 1.91 cm, the pitch angle of the blade varies from 21° at the root to 0° at the tip, and the blade is 3D printed with acrylonitrile butadiene styrene.

[0026] The power generation of the system is then determined by the heave and sink motion of the wave energy buoy, and the power generation is calculated based on the existing Lanchester-Betz formula.

[0027] A wind turbine is placed at both ends and the center of the Y axis respectively. The two ends of the Y axis are the upstream and downstream positions respectively. A plurality of tidal turbines are placed between the two wind turbines. The plurality of tidal turbines are arranged at equal distances.

[0028] Specifically, the distance between the wind turbine and the tidal turbine is L1, the distance between the two tidal turbines is L2, and the distance between the two Y axes is L3.

[0029] Among them, L1=3D~5D, L2=1D~3D, L3=3D~5D, and D=1.25m.

[0030] In this embodiment

[0031] Different multi-energy complementary spatial array configurations were constructed with L1=3D~5D, L2=1D~3D, and L3=3D~5D as different embodiments, and simulation experiments were conducted, wherein the wind turbine prototype used was a 1 / 25 scale model based on 5MW, a semi-submersible wind turbine model proposed by the National Renewable Energy Laboratory (NREL) of the United States. Its blade airfoils are DU21_A17, DU25_A17, DU30_A17, DU35_A17, DU40_A17, and NACA64_A17; the blades of the tidal turbine are NACA4412 airfoils.

[0032] In the experiment, a wave meter was placed 4.5m upstream of the upstream wind turbine model to measure the incoming wave height. Three wave meters were placed 0.5m on the sides of the three wind turbines, aligned with the wave energy buoy models on the same wave orthogonal to measure the wave height of the three wave energy buoy models. Flow meters were located 0.5D upstream and downstream of the tidal turbine blades to measure the water velocity before and after passing through the blades. Three laser displacement sensors were used to measure the heave displacement of the wave energy buoy. Three anemometers were used to measure the wind speed at a distance of 5-9D downstream of the upstream wind turbine, with the multi-energy complementary spatial array directly facing the blower and 14.5m away from the wave generator.

[0033] By measuring the average wind speed at different locations downstream of the wind turbine, the wind speed decay after passing the wind turbine blades can be assessed. Figure 2-Figure 3 The wind speed decay within 0-9D downstream of the rotor is shown under three different inflow conditions with and without upstream wind turbines. When there is a turbine, the wind speed decay rate behind the wind turbine can reach up to 80%, and at 7D, the wind speed returns to the same level as when there is no turbine. This shows that the effect of the upstream wind turbine on the wind speed decay disappears at this distance. Therefore, the upstream and downstream wind turbine spacing in this experiment is set to 7D, at which time the wake effect of the upstream turbine on the downstream wind turbine can be ignored, and the power generation efficiency of the downstream wind turbine will not be significantly affected; at the same time, in order to determine the spacing between the rows of array units, the measurement point Disp3 is set between 3-5D, indicating the position of another row of turbines. Figure 6 The wind speed at three measurement points with and without upstream turbines is shown. The figure shows that the upstream turbine causes additional wind speed attenuation in the lateral direction of the wind turbine line. The additional attenuation rate is 27.52% to 41.66% for 3D, 6.99% to 8.07% for 4D, and 4.53% to 7.32% for 5D. It can be observed that the wind speed attenuation effect caused by the upstream wind turbine increases with the decrease in spacing. Considering this effect and the space utilization factor, the lateral spacing of the wind turbines is set to 4D, and the spacing of the Y axis is 4D.

[0034] When water flows through the tidal turbine, it drives the blades to rotate, thereby collecting energy while reducing the water flow velocity. Table 1 shows the rotation state of the turbine blades under different incoming flow conditions. It can be seen that as the flow velocity increases from 0.2m / s to 0.4m / s, the number of turbines that can be started increases from 2 to 4. Table 2 shows the upstream and downstream flow velocities, attenuation rates, and energy utilization rates of different turbines. The data show that the number of turbines has little effect on the flow velocity attenuation rate and energy utilization. However, as the number of turbines increases, the flow velocity through the downstream turbine decreases, thereby reducing the energy that the turbine can capture. Based on this, it is believed that the configuration using three turbines is optimal.

[0035]

[0036] Table 1. Turbine blade rotation status

[0037]

[0038] (a) Inflow velocity 0.2 m / s

[0039]

[0040] (b) Inflow velocity 0.3 m / s

[0041]

[0042] (c) Inflow velocity 0.3 m / s

[0043] Table 2. Flow rate attenuation rate and energy utilization rate

[0044] Therefore, according to the above experiments, the preferred solution for the multi-energy complementary spatial array configuration is to set up a number of wind turbines on each Y axis, with three tidal turbines between two wind turbines, and the three tidal turbines are equidistantly arranged, where the spacing between two wind turbines is 7D, and the spacing on the Y axis is 4D, which is the optimal solution.

[0045] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A multi-energy complementary system under wind, wave and current combined load, characterized in that: The system includes a multi-energy complementary space array configuration composed of wind turbines, wave energy buoys and tidal turbines, wherein the wind turbines, wave energy buoys and tidal turbines are each provided with a plurality of wave energy buoys coupled with the wind turbines, and the multi-energy complementary space array configuration includes a plurality of wind turbines, wave energy buoys and tidal turbines on the same Y axis, and the plurality of Y axes are arranged at equal intervals along the X axis.

2. The multi-energy complementary system under wind, wave and current combined load according to claim 1 is characterized in that: A wind turbine is placed at both ends and the center of the Y axis respectively. The two ends of the Y axis are the upstream and downstream positions respectively. A plurality of tidal turbines are placed between the two wind turbines. The plurality of tidal turbines are arranged at equal distances.

3. The multi-energy complementary system under wind, wave and current combined load according to claim 2 is characterized in that: The distance between the wind turbine and the tidal turbine is L1, the distance between the two tidal turbines is L2, and the distance between the two Y axes is L3.

4. The multi-energy complementary system under wind, wave and current combined load according to claim 3 is characterized in that: The L1=3D~5D, L2=1D~3D, L3=3D~5D, wherein D=1.25m.

5. The multi-energy complementary system under wind, wave and current combined load according to claim 1 is characterized in that: The preferred solution of the multi-energy complementary spatial array configuration is to arrange a plurality of wind turbines on each Y axis, and three tidal turbines are arranged between two wind turbines, and the three tidal turbines are arranged at equal distances.

Images