| At present,there are many types of wave energy conversion devices,each with its own advantages and disadvantages.However,factors such as high power generation costs,low energy conversion efficiency,and reliability and safety to be improved are still the fundamental reasons why wave energy conversion devices are difficult to be widely commercialized.Considering several factors such as power generation cost,total efficiency,reliability and safety,the oscillating buoy wave energy conversion device has obvious advantages than others.Therefore,the research,design and optimization of the oscillating buoy wave energy conversion device will be an important development direction of the wave energy conversion device."Haiyuan No.1" is an oscillating buoy wave energy conversion device developed by Zhejiang Ocean University,and "Hai Da No.1" is a rocker buoy wave energy conversion device further developed on the basis of "Haiyuan No.1".The main research content of this article is as follows:1)Taking the "Haida No.1" wave energy converter as the research object,through theoretical analysis,the buoy in the "Haiyuan No.1" that adopts heave motion is improved.An improved scheme for the buoy in Haida No.1 to adopt the form of swing motion is proposed.Then the hydrodynamic performance difference of the buoy under the two different motion forms of heave and swing is analyzed by numerical simulation under the regular wave.Finally,the irregular wave data obtained during the sea trial of "Haiyuan No.1" is used to compare and analyze the hydrodynamic performance of these two types of buoys;The results show that the hydrodynamic performance of the buoy can be effectively improved by the swing motion compared to the oscillating motion in both regular and irregular waves.2)The force analysis of the buoy in "Haida No.1" is carried out,and the two-dimensional analytical solution of the buoy is derived based on the linear wave theory.According to the two-dimensional analytical solution,the buoy is optimized from the aspects of pendulum length,pendulum angle,buoy shape,buoy draft,buoy shape width,wave height,and PTO damping to further improve the hydrodynamic performance of the buoy.3)Based on the working principle of "Haida No.1",a hydraulic simulation model was built using AMESim software.In order to study the actual energy transfer process and energy transfer characteristics of wave energy converters,regular waves are used as input signals.The influence of key parameters such as input signal,check valve starting pressure,accumulator volume and other key parameters on wave energy transmission is analyzed through simulation.In addition,the "wave rack + group cylinder" technology was studied in detail.The critical self-excited vibration curve of hydraulic cylinder movement is proposed by using linear analysis method,and the influence of external load,hydraulic cylinder load mass,stroke length,spring stiffness and piston area on the performance of hydraulic cylinder is studied by AMESim simulation.4)A physical model of "Haida No.1" with a scale ratio of 1:2.5 was established.Then,the physical model was tested in the laboratory hydrodynamic pool to study the influence of buoy draft,wavelength and buoy diameter relationship,wave height and system load on the performance of the device.After research,the swing motion of the buoy proposed in "Haida No.1" can effectively improve the hydrodynamic performance of the buoy compared to the traditional heave motion of the buoy.The movement characteristics of the buoy make full use of the two parts of the fluid potential energy and the fluid kinetic energy.The hydraulic simulation test verifies that the hydraulic system can efficiently and stably convert wave energy into electrical energy.The physical model test of the scale ratio in the laboratory hydrodynamic pool not only verifies the reliability of the device,but also verifies that the device has a high conversion efficiency even under small waves. |
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