Research On Multi-energy Hybrid Power Generation System Applied To Cage Culture

The world today is short of energy.The ocean as a clean and pollution-free renewable energy has become the focus of the world’s common concern.At present,power generation technologies such as tidal current energy,tidal energy,wave energy,and offshore wind energy have matured,but ocean energy has poor stability and low energy density,and single energy power generation is unstable.How to improve system output stability and reduce ocean energy development cost has become a major trend in the study of multi-energy hybrid power generation systems at sea.Aiming at the problem of improving the energy conversion rate by comprehensive utilization of multiple energy sources at sea,this paper proposes a research on multi-energy complementary power generation system applied to cage culture.Deep-water cage culture is easily damaged by currents and winds,and modern cage culture enters an intelligent stage.The electric energy required for feeding equipment such as feeding machine,monitoring device and cage cleaning device is difficult to supplement.The multi-energy complementary power generation system applied to cage culture perfectly solves this problem.The multi-energy complementary power generation system applied to cage culture is mainly composed of horizontal axis tidal energy turbine and anti-wind wave self-powered floating breakwater.The horizontal axis tidal energy turbine is mainly used for the protection of the net clothing below the sea surface,preventing the underwater net clothing from causing damage under the long-term impact of the tidal energy,and have the effect of choked flow and power generation;The antiwind wave self-powered floating breakwater is mainly used for the protection of net cages on the sea,It protects the railings and net clothes of net cages on the sea from the ravages of strong winds and waves,It has the function of resisting wind and wave to generation electricity.Mainly done the following work:(1)Statistics on the distribution of marine energy in China,studied the hydrological status of Fujian,and analyzed the working conditions of multi-energy complementary power generation system applied to cage culture;(2)Introduce the overall design scheme and working principle of multi-energy complementary power generation system applied to cage culture.The blade momentum theory is applied to analyze the force acting on the blade,and the impeller is calculated according to the circumferential and axial inducing factors.The thrust and torque are deduced from Bates limit,and the calculation methods of energy gain coefficient and tip speed ratio are finally obtained.The N-S equation of the turbulence model is used to calculate and analyze the watershed.The simulation process uses a non-coupled implicit algorithm to solve the two-dimensional steady flow.Applying the sliding grid method in the dynamic region calculation grid to perform mesh division;(3)The blade airfoil of the horizontal axis tidal energy turbine for cage culture has been selected and designed.The profili airfoil design software is used for the selection analysis.The Boroginis,GOE165 and NACA663 under different Reynolds numbers are analyzed.The values of lift,drag,lift-to-drag ratio and pitching moment of three airfoils were compared.The Bogginis was selected as the airfoil.The first half of the Brogginis airfoil was rotated 180° around the midpoint of the middle arc to design a symmetrical S airfoil.Application of 3D modeling software to the application of 3D model fitting method for impeller line type extraction,and the Bladegen software is used to perform the quadratic fitting of the impeller line.The angle of the data point of the profile line to the leading edge and trailing edge line is adopted.Make adjustments to control the line type of the pressure surface and the suction surface.The post-simulation processing results in turn continue to optimize the impeller in the Bladegen software.The relevant parameters were extracted and the simulation characteristics of the turbine output turbine were applied.The experimental experiment showed the relationship between different simulated flow rates and the energy-receiving efficiency.The impeller achieved selfstarting at a seawater flow rate of 0.5 m/s.(4)The self-powered floating breakwater bank used in cage culture was designed.The basic concept,structure design and working principle were analyzed.Using the design method of vertical axis turbine impeller for reference,the model is simplified.Passive motion analysis of the breakwater by fluent hydrodynamic analysis software,the torque of the breakwater at three different flow rates is calculated,and the final torque values tend to be stable,indicating the stability of the breakwater device under working conditions.The pressure and velocity were analyzed by a simulated cloud image at an inlet velocity of 4.47 m/s.Finally,the experiment is carried out to verify that the peak speed ratio of the simulated value and the experimental value is compared with the energy-efficiency comparison curve.When the peak speed ratio is 2.0,the energyreceiving efficiency reaches a maximum of 20%.The experimental value and the simulation value are within 10%,which proves that the laboratory experiment has credibility;(5)Due to the instability of the wind and wave,the anti-lock brake circuit are also applied to prevent damage to the bank and the load caused by excessive wind and waves at sea.The multi-energy complementary power generation system applied to cage culture can simultaneously block flow and resist wind and waves,and overcome the shortcomings of unstable single power supply.Reasonable layout and configuration make multi-energy coordination and utilization,improve system utilization and energy conversion rate,and play an important role in the intelligent and automated development of cage culture in China.