A multi-energy complementary system under combined load of wind, waves and current

Abstract

This invention discloses a multi-energy complementary system under combined wind, wave, and current loads, belonging to the field of marine energy utilization technology. The system includes a multi-energy complementary spatial array configuration composed of wind turbines, wave energy buoys, and tidal turbines. Several wind turbines, wave energy buoys, and tidal turbines are provided. The wave energy buoys are coupled to the wind turbines. The multi-energy complementary spatial array configuration includes several wind turbines, wave energy buoys, and tidal turbines on the same Y-axis, with the Y-axis extending at equal intervals along the X-axis. This system can fully utilize the wave and wind energy on the sea surface for power output. At the same time, by utilizing the coupling between the wind turbines and the wave energy buoys, the wave height at the wave energy buoys can be increased during the placement of the tidal turbines, thereby increasing the power generation.

Description

Technical Field

[0001] This invention belongs to the field of marine energy utilization technology, and particularly relates to a multi-energy complementary system under combined wind, wave and current loads. Background Technology

[0002] Powering offshore islands is of great significance but also presents considerable challenges. Island regions possess abundant marine energy resources, including wind, solar, wave, and tidal energy, but nearshore islands still face the challenge of insufficient energy supply. Although various marine energy harvesting devices have been developed, existing limited research has shown that different types of energy are harvested and utilized through different devices. Therefore, integrating multiple energy sources into a complementary system requires further research. The inventors have designed a combined system for the complementary utilization of multiple energy sources, based on wave energy buoy power supply and incorporating wind and tidal energy. Summary of the Invention

[0003] The purpose of this invention is to provide a multi-energy complementary system under combined wind, wave and current loads, which can make full use of wave and wind energy on the sea surface to output electrical energy. At the same time, by using the coupling of wind turbines and wave energy floats, the wave height at the wave energy float can be increased during the placement of the tidal turbine, thereby increasing the power generation.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A multi-energy complementary system under combined wind, wave, and current loads includes a multi-energy complementary spatial array configuration comprising wind turbines, wave energy floats, and tidal turbines. Several wind turbines, wave energy floats, and tidal turbines are provided, and the wave energy floats are coupled to the wind turbines. The multi-energy complementary spatial array configuration includes several wind turbines, wave energy floats, and tidal turbines on the same Y-axis, with the Y-axis extending at equal intervals along the X-axis.

[0006] The multi-energy complementary system in this application is a constructed multi-energy complementary spatial array configuration. This configuration can be used to enhance the efficiency of offshore renewable energy collection. The ocean mainly includes wind energy, wave energy, and tidal energy (currents), which interfere with each other. This application discloses a related multi-energy complementary spatial array configuration, in which placing three tidal turbines between upstream and downstream wind turbines is the optimal method. This increases the wave height of the downstream wave energy converter (WEC) and increases wave energy without affecting the energy utilization efficiency of the WEC. Therefore, adopting the multi-energy complementary spatial array configuration of this application can improve utilization efficiency.

[0007] Furthermore, the multi-energy complementary spatial array configuration provided by the present invention is mainly composed of various devices, and the specific differences of the array lie in the placement position and the placement spacing. The relevant positional relationships and spacing characteristics are disclosed in this application, which are therefore essential features of the multi-energy complementary spatial array configuration.

[0008] As a preferred embodiment of the present invention, a wind turbine is placed at both ends and the center of the Y-axis, with the two ends of the Y-axis being the upstream and downstream positions, respectively. A plurality of tidal turbines are placed between the two wind turbines, and the plurality of tidal turbines are equidistant from each other.

[0009] As a preferred embodiment of the present invention, 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-axis is L3.

[0010] As a preferred embodiment of the present invention, L1 = 3D to 5D, L2 = 1D to 3D, L3 = 3D to 5D, where D = 1.25m.

[0011] As a preferred embodiment of the present invention, the preferred embodiment of the multi-energy complementary spatial array configuration is to arrange a plurality of wind turbines on each Y-axis, and to arrange three tidal turbines between two wind turbines, with the three tidal turbines being equidistant from each other.

[0012] The beneficial effects of this invention are:

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

[0014] 2. Wind, waves, and tides are abundant energy sources on the sea surface and are in a state of mutual interference. Through the multi-energy complementary array structure of this application, the wind turbine set in the upstream of 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 turbine and thus affecting the power generation efficiency. Attached Figure Description

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

[0016] Figure 2 This is a linear relationship diagram of wind speed attenuation in a multi-energy complementary system under combined wind, wave, and current loads provided by this invention, with and without an upstream wind turbine at a wind speed of 2.28 m / s.

[0017] Figure 3 This is a linear relationship diagram of wind speed attenuation in a multi-energy complementary system under combined wind, wave, and current loads provided by this invention, with and without an upstream wind turbine at a wind speed of 1.6 m / s.

[0018] Figure 4 This is a linear relationship diagram of wind speed attenuation in a multi-energy complementary system under combined wind, wave, and current loads provided by this invention, with and without an upstream wind turbine at a wind speed of 1.2 m / s.

[0019] Figure 5 This is a linear relationship diagram of the lateral wind speed attenuation of the multi-energy complementary system under combined wind, wave and flow loads provided by the present invention, with and without an upstream wind turbine at a wind speed of 2.28 m / s.

[0020] Figure 6 This is a linear relationship diagram of the lateral wind speed attenuation of the multi-energy complementary system under combined wind, wave and flow loads provided by this invention, with and without an upstream wind turbine at a wind speed of 1.6 m / s.

[0021] Figure 7 This is a linear relationship diagram of the lateral wind speed attenuation of a multi-energy complementary system under combined wind, wave and current loads provided by this invention, with and without an upstream wind turbine at a wind speed of 1.2 m / s. Detailed Implementation

[0022] To further understand the invention's content, features, and effects, the following embodiments are provided, and detailed descriptions are given in conjunction with the accompanying drawings.

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

[0024] like Figure 1 As shown, the multi-energy complementary system under combined wind, wave, and current load includes a multi-energy complementary spatial array configuration consisting of wind turbines, wave energy floats, and tidal turbines. Several wind turbines, wave energy floats, and tidal turbines are provided. The wave energy floats are coupled to the wind turbines. The multi-energy complementary spatial array configuration includes several wind turbines, wave energy floats, and tidal turbines on the same Y-axis. The several Y-axiss are arranged at equal intervals along the X-axis.

[0025] In this embodiment, the wind turbine has a hub diameter of 8 cm and a rotor diameter of 125.6 cm. The wind turbine tower is made of steel, and the outer shell is 3D printed using acrylonitrile butadiene styrene. The wave energy float is a ring-shaped wave energy converter, and the wave energy float is 3D printed using acrylonitrile butadiene styrene with a waterproof coating on the surface. The tidal turbine has a diameter of 20 cm and a hub diameter of 3.82 cm. The tidal turbine blade root chord length is 3.82 cm, the blade tip chord length is 1.91 cm, and the blade pitch angle varies from 21° at the root to 0° at the tip. The blades are 3D printed using acrylonitrile butadiene styrene.

[0026] Furthermore, the power generation of the system is determined by the heave motion of the wave energy float, and its power generation is calculated based on the existing Lanchester-Betz formula.

[0027] A wind turbine is placed at each of the two ends and the center of the Y-axis, with the two ends of the Y-axis being the upstream and downstream positions, respectively. Several tidal turbines are placed between the two wind turbines, and the tidal turbines are equidistant from each other.

[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-axis lines is L3.

[0029] Where L1 = 3D to 5D, L2 = 1D to 3D, L3 = 3D to 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 for simulation experiments. The wind turbine prototype used was a 5 MW 1 / 25 scale model, a semi-submersible wind turbine model proposed by the National Renewable Energy Laboratory (NREL). Its blade airfoils were DU21_A17, DU25_A17, DU30_A17, DU35_A17, DU40_A17, and NACA64_A17; the tidal turbine blades were NACA4412 airfoil.

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

[0033] By measuring the average wind speed at different locations downstream of a wind turbine, the wind speed attenuation after passing through the turbine blades can be assessed. Figure 2-Figure 3 The diagram illustrates the wind speed attenuation within 0-9D downstream of the rotor under three different inflow conditions with and without upstream wind turbines. With turbines present, the wind speed attenuation rate behind the turbines can reach up to 80%, and at 7D, the wind speed recovers to the same level as without turbines. This indicates that the effect of upstream wind turbines on wind speed attenuation disappears at this distance. Therefore, the upstream and downstream wind turbine spacing in this experiment is set to 7D, at which point the wake effect of the upstream turbine on the downstream wind turbine is negligible, and the power generation efficiency of the downstream wind turbine is not significantly affected. Simultaneously, to determine the spacing between rows of array elements, measurement point Disp3 is set between 3-5D, representing the position of another row of turbines. Figure 6 The figure shows the wind speeds at three measurement points with and without upstream turbines. It demonstrates that upstream turbines cause additional wind speed attenuation in the lateral direction along the wind turbine path. The additional attenuation rate is 27.52%–41.66% for 3D, 6.99%–8.07% for 4D, and 4.53%–7.32% for 5D. It can be observed that the wind speed attenuation effect caused by upstream turbines increases with decreasing spacing. Considering this effect and space utilization factors, the lateral spacing of the wind turbines is set to 4D, and the spacing along the Y-axis is also set to 4D.

[0034] When water flows through a tidal turbine, it drives the blades to rotate, thereby harvesting energy while reducing the water flow velocity. Table 1 shows the turbine blade rotation under different inflow conditions. It can be seen that as the flow velocity increases from 0.2 m / s to 0.4 m / 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 for different turbines. The data indicate that the number of turbines has little impact on the flow velocity attenuation rate and energy utilization rate. However, as the number of turbines increases, the flow velocity through the downstream turbine decreases, thus reducing the energy that the turbines can capture. Based on these findings, a configuration using three turbines is considered optimal.

[0035]

[0036]

[0037]

[0038]

[0039] Therefore, based on the above experiments, the preferred scheme for the multi-energy complementary spatial array configuration is to set up several wind turbines on each Y-axis, with three tidal turbines between two wind turbines and the three tidal turbines being equidistant from each other. The optimal scheme is that the distance between two wind turbines is 7D and the distance between the Y-axis is 4D.

[0040] While 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 these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A multi-energy complementary system under combined wind, wave, and current loads, characterized in that, The system comprises a multi-energy complementary spatial array configuration consisting of wind turbines, wave energy floats, and tidal turbines. Several wind turbines, wave energy floats, and tidal turbines are provided. The wave energy floats are coupled to the wind turbines. The multi-energy complementary spatial array configuration includes several wind turbines, wave energy floats, and tidal turbines on the same Y-axis. The several Y-axiss are arranged at equal intervals along the X-axis. A wind turbine is placed at each of the two ends and the center of the Y-axis, with the two ends of the Y-axis being the upstream and downstream positions, respectively. Several tidal turbines are placed between the two wind turbines, and the tidal turbines are equidistant from each other.

2. The multi-energy complementary system under combined wind, wave, and current loads as described in claim 1, 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-axis lines is L3.

3. The multi-energy complementary system under combined wind, wave, and current loads according to claim 2, characterized in that, L1 = 3D to 5D, L2 = 1D to 3D, L3 = 3D to 5D, where D = 1.25m.

4. The multi-energy complementary system under combined wind, wave, and current loads as described in claim 1, characterized in that, Three tidal turbines are located between the two wind turbines, and the three tidal turbines are equidistant from each other.

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