| In recent years, with the country's increasing emphasis on environmental issues, the wind power technology has been developed rapidly, wind turbine blade as the important part of wind turbine, has become a hot spot of wind power technology research. Modern wind turbine blades made by vacuum-assisted molding technology(VARI), with in a variety of fiber and epoxy resin as raw material. In VARI molding process, the resin flow filling is a key part, if this part lost control, it will result in bubbles, dry spots and other defects which can affect the performance of wind turbine blades, these defects is very common which in larger thickness dimension of wind turbine blades root and other parts. Therefore, Analysis and study wind turbine blades root of the resin flow filling process has become one of the key issues plagued the large blade manufacture.This paper study of the rheological properties of the matrix resin, fabric permeability testing, in combination with the wind turbine blades root resin mold filling Numerical Simulation Technology, analyze the resin injection molding of VARI, and focuses on the optimization of the resin filling process parameters optimization method, provide guidance for the actual production of wind turbine blades.Firstly, the variable temperature and thermostat rheological properties of the have been studied of the 2511-1A-BS cured epoxy resin. The experimental results show that the viscosity of this cured epoxy resin is decreased as the temperature rises because the molecular chain motion increases under variable temperature conditions. When the temperature rises to about 50?, the curing reaction begins, and the effect of molecular chain motion increases and the thickening effect because of resin curing reaction has reached equilibrium, so the low viscosity platform appeared. When the temperature rises to above 100?, the curing reaction of this rein is dominant, so that the viscosity of this resin system has a sharp rise. The result of this experiment provides the basis of experimental data for the subsequent permeability testing experiments and simulations, also provide a basis to the actual production operation time, and temperature process window selection.Secondly, tested the in-plane and thickness direction permeability of diversion media and tri-axial fabrics, and improve the traditional the permeability testing methods in the thickness direction. Experiments result show that the in-plane permeability of diversion medium is 3.038×10-9m2. in-plane the permeability is between 1.59×10-12-2.93×10-11 m2 of the 6-20 layer tri-axial fabrics, and its vertical and horizontal permeability ratio are about 5, not change much with the number of layer increased. But the in-plane or the thickness direction permeability are occurred that first decrease, then stable with the increase of the number of layer.Thirdly, according to the thin ply tri-axial fiber fabric permeability experiments, analyzed the feasibility of the resin filling process simulation. The results show that there is a deviation between the experiment and simulation, but the maximum deviation is less than 15%, which proved the feasibility of the simulation.Finally, the resin filling process simulation of the 1.5MW-45.2m embedded and non-embedded wind turbine blade root has been studied. Simulation results show that there is the risk of filling defects that the resin will priority filled no fiber area, making the resin flow becomes irregular in the embedded blade root filling process. This article is also designed four different injection schemes for non-embedded type blade root, analysis their resin filling time distribution and the proportion of the final resin filling, found under the practical conditions that the injection pressure is 0.095 MPa, resin viscosity is 0.147 Pa.s, the NO1 injection scheme is the best injection scheme for 1.5MW-45.2m non-embedded wind turbine blade root. |
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