| The icing problem of wind turbine blades in low temperature and high humidity areas limits the further development of wind power industry.The different characteristics of the service environment of the fan increase the diversity of blade icing.Exploring the icing law affected by the flow of supercooled water droplets in the spanwise and end of the blade,the temperature rise characteristics of the blade surface after applying the thermal power,and the highly adaptive anti-icing and deicing structure to achieve the efficient and stable operation of the fan in the icing environment have become the key problems to be solved urgently.In this paper,the numerical calculation of icing and the performance test of NE-300 H vertical axis wind turbine(VAWT)blades are carried out.Considering the flow characteristics of water film on the blade surface and the nonlinear icing characteristics of continuous time,the icing and anti-icing of wind turbine blades are studied in depth from the perspective of temperature rise characteristics of blade surface.The main research contents include:(1)A three-dimensional VAWT blade icing calculation method is established to supplement the influence of blade span on icing.A three-dimensional geometric model was established by intercepting the end of the VAWT blade,and the flow state near the wall of the blade was solved by the SpalartAllmaras turbulence model.Aiming at the particularity of the water film flow on the blade surface,based on the flow control equation and the law of mass and heat transfer,combined with the Euler method and the icing thermodynamic model,a three-dimensional VAWT blade continuous icing numerical calculation method was proposed.(2)A three-dimensional VAWT blade icing model is established to decouple the continuous multi-field mechanism at the microscopic particle level.From the perspective of multi-field continuous transmission,a continuous model of three-dimensional field coupling synergy during VAWT blade icing is established.The accuracy of the model is verified by comparing and analyzing the micro-flow state,the trajectory of supercooled water droplets and the icing characteristics of blades.The blade icing characteristics were simulated step by step in FENSAP-ICE software according to the time scale.From the perspective of the disturbance intensity of the icing roughness on the flow field,the influence of environmental factors and VAWT operating conditions on the icing law of the blade is compared and analyzed.The variation of aerodynamic characteristics of VAWT blades during icing service under multiple operating conditions is studied.The results show that the icing is mainly concentrated on the leading edge of the blade,and the ridge ice shape is formed at the end of the blade.Temperature and liquid water content are the main influencing factors of icing.The glaze ice causes more serious flow loss than the rime ice,and the aerodynamic performance of the blade can be slightly improved when the ice is covered for 10 minutes.(3)Research on temperature rise characteristics of blade surface and optimization of anti-icing and de-icing.According to the icing law of blades under multiple working conditions,the chordwise and spanwise icing characteristics of blades,the numerical calculation model of anti-icing and de-icing is established with the goal of minimizing the thermal load of antiicing and de-icing applied to the blade surface.Combined with the structural parameters of the blade and the temperature rise characteristics at different positions,the anti-icing and deicing structure and distribution are designed and optimized.The output simulation experiment of VAWT blade after icing is constructed.Through the measurement and comparative analysis of the state data during the operation of the fan before and after icing,the influence of icing on the output performance of the fan is verified. |
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