Study On Heat Dissipation Model And Optimization Of Offshore Wind Turbine Cabin

Among renewable energy sources,wind energy development is flexible.It can be centrally developed to build offshore wind farms or become part of distributed energy systems.Due to climate warming and land use problems,China’s wind energy resource es are gradually decreasing.Under such conditions,the construction volume of high-capacity offshore wind turbines is gradually increasing with the advantages of large wind volume and low turbulence intensity.However,during the daily operation of large capacity offshore wind generator,a number of high temperature and heating components,such as control cabinet and yaw reducer,are centralized arranged in the engine room.Excessive heat generation makes it easy to have the problem of excessive temperature in the cabin,which greatly reduces the operation efficiency of the unit,and even leads to power outage and shutdown in serious cases.At the same time,due to the harsh offshore environmental conditions,offshore wind turbines must adopt closed systems,unable to directly exchange heat with the outside air.Therefore,it is of great significance to conduct temperature field,flow field simulation and heat load analysis on heat dissipation of closed offshore wind turbine cabin,and take corresponding measures to maintain heat balance and improve heat dissipation of the cabin.This paper takes the wind turbine engine room model provided by a company as the research object,adopts the research methods of literature review,establishing mathematical model and numerical simulation calculation,and builds a simplified physical model of the engine room by using Solid Works software on the basis of theoretical analysis and reasonable assumptions on the heat dissipation of the engine room.COMSOL Multiphysics software was used to simulate the air flow and temperature distribution in the engine room.By simulating and analyzing the temperature distribution of the air domain in the engine room,the temperature distribution of the engine room shell,the temperature distribution on the surface of the control cabinet of the main heat source,the temperature distribution of the main gas outlet and the gas flow state in the engine room,the reasons for the excessive temperature and unreasonable gas flow in the cabin were studied,and the key improvement areas were explored.In order to ensure the feasibility of the improvement scheme,the influence of several major external environmental conditions on engine room heat dissipation was first explored.Finally,it was found that the influence of external solar radiation on engine room heat dissipation was negligible,and the influence of external temperature and external wind speed on engine room heat dissipation was limited.Therefore,after setting reasonable external environmental parameters,the optimal theoretical optimization scheme is optimized--adding a set of industrial air conditioners for the engine room,and the optimized engine room model is simulated again to compare and analyze the heat dissipation of the engine room before and after improvement.At the same time,in order to achieve the optimal heat dissipation optimization effect,the improvement scheme was further studied.By adjusting the location,wind direction and number of tuyere,the distribution of temperature field and flow field in the engine room under different conditions was compared,and the optimal improvement scheme was finally determined.The results show that after the addition of industrial air conditioning,the air temperature in the engine room decreases,the airflow velocity increases,the heat transfer effect is significantly enhanced,the average air temperature in the engine room,the surface temperature of high temperature heating parts and the main gas outlet temperature are obviously decreased,but there are local poor heat dissipation.At the same time,by analyzing the simulation results,which can be concluded that the wind turbines installed capacity of 4 MW,only a 15 k W industrial air conditioning refrigeration power can achieve ideal heat strengthening effect,air conditioning power consumption accounted for less than0.5% of the unit installed capacity,namely to add industrial air conditioning scheme for the influence of the wind turbine capacity is almost negligible.In addition,in order to ensure the reliability of the simulation results,the relative errors between the test data and the simulation results are all less than 1%,which positively confirms the reliability of the simulation results.Through further exploration of the optimization scheme,and based on the control variable method,it is found that the optimal scheme of placing tuyere in the middle of the engine room,setting two tuyere and blowing backward 105° are respectively in the influence of their respective variables.Finally,it is determined that setting two tuyere blowing backward 105° near CCN2 in the middle of the engine room is the optimal heat dissipation optimization scheme.