Study On Hydrodynamics And Mooring System Of Floating Photovoltaic System

Since the concept of building new power system dominated by new energy has been proposed in our country,floating photovoltaic technology is favored in industry.Because the application development in inland waters tends to be mature,but the sea in our country is vast and abundant,and its resources reserves and technical development enable Marine photovoltaic to possess the potential for large-scale development.Therefore,Offshore floating photovoltaic technology has become a key concern.However,in the Marine environment,floating structures will be subjected to wind,wave,current and other complex forces,so it is impossible to directly and large-scale application on the sea surface.Therefore,the feasibility and challenge of studying the application of floating photovoltaic floating system and mooring system in Marine environment are parallel.This article takes the floating array of photovoltaic power plants located along the coast as the research object,and analyzes the motion response of the floating array floating body considering the influence of connection stiffness;Considering the failure of floating body connectors,calculate the motion response of multiple floating bodies in a square array and the stress situation of the connectors through time-domain analysis;The performance of the floating array anchoring system under changing wind,wave and current conditions.The specific research content is as follows:(1)Based on the experimental foundation of large-scale multi floating body connectors,a coupling model of multi floating body modules and mooring systems is constructed,and time-domain analysis is conducted to compare the simulation results with the experimental results.The results show that the numerical calculation and model test results are in good agreement,and the error between the two is within 10%,which verifies the accuracy of the hydrodynamic numerical simulation method.(2)Verify the feasibility of CFD calculation for predicting loads by comparing it with numerical simulations of wind tunnel tests on floating single body models;Then 2D and2.5D local fine calculation is carried out for the floating array,and high-precision local calculation results are obtained by comparison and correction.The influence of the shielding effect of the floating array is analyzed.Then the six degrees of freedom motion response of multiple floating bodies under different connection stiffness of the floating photovoltaic array is calculated,and the six degrees of freedom motion of horizontal and vertical floating bodies is evaluated.Finally,the influence of connection stiffness on the relative motion between floating bodies and the load of connectors is analyzed.The results indicate that the selection of connector stiffness should meet the requirements of better relative motion constraints of the floating body and smaller connector load as much as possible.(3)Considering the failure of floating body connections in photovoltaic power plants,this thesis analyzes the hydrodynamic performance of the floating array after multiple failures of the floating body connections from two aspects: the force acting on multiple floating body connections and the response of the floating body to translational motion.The research results indicate that the failure position of multiple floating body connections at any incident angle depends on the initial failure position;Each time the floating body connection fails,the stress on adjacent floating body connections in the same column increases,and the subsequent failure causes more severe damage to the array structure..(4)Exploring the effects of different tightening degrees and wave conditions on the floating array mooring and mooring system tension of photovoltaic power plants under large tidal range conditions,conducting research on the floating array mooring system,and analyzing the characteristics of floating array movement and changes in mooring line tension under the condition of mooring line fracture and failure.Secondly,considering that the flow direction and velocity of the real ocean current cannot be fixed,analyze the response results of the floating array under different ocean current conditions;Finally,use hydrodynamic software to simulate the ocean current conditions with changes in direction and time.The research results indicate that changes in tidal range have a significant impact on the damping of the initial tensioning process of mooring under irregular waves;Under local mooring failure,the overall motion response of the floating square array is greatly affected by the surge direction.The average maximum effective tension at the wave end increases by 6.5%,while the average maximum effective tension of the lateral mooring line remains basically unchanged;With different incident flow angles,the overall motion trajectory of the floating body is relatively consistent;But its initial motion trajectory gradually decreases as the angle of the incident flow direction increases.