| If the temperature control in the blade production process does not use the blade mold with electric heating system,the heating temperature is higher than the circulating water heating,which can meet a variety of different heating needs,and there is no need to set the circulating pipeline,which can greatly reduce the weight of the mold.At present,there are still some problems in the electric heating method of blade mold: for example,the uneven heat transfer in the working process of blade mold,the hysteresis between the heating layer temperature and the cavity surface temperature and so on,which leads to the excessive temperature difference between the whole mold and the cavity surface.If the temperature is not controlled properly in the blade production process,the blade mold will be burned locally,resulting in losses.In view of the above-mentioned problems,this paper improves the structure of the electric heating blade mold,optimizes the average cavity surface temperature,cavity surface temperature difference,overall average temperature,overall temperature difference and other evaluation indicators of the blade mold.Finally,the thermal conductivity of the blade mold is improved.The specific research content is as follows:Firstly,the numerical model and physical model of the blade mold are established.The simplified heat transfer model of the blade mold and the three-dimensional differential equation of the temperature field with internal heat source were analyzed.Combined with several necessary assumptions,the control equation and mathematical model of the mold temperature field heat transfer model are established,and the initial conditions,boundary conditions and physical conditions of the mold temperature field are determined,and the convective heat transfer coefficient required to solve the temperature field control equation is calculated.Secondly,a numerical analysis of the variables that affect the thermal conductivity of the mold is carried out.First,the physical parameters required for the numerical analysis of the temperature field of the blade mold were measured and calculated,and the six indicators for evaluating the thermal conductivity of the blade mold were determined.Then,the Transient Thermal module was used to perform the analysis on the blade molds with different design variables.Final,the influence mechanism of various factors on the thermal conductivity of the blade mold is obtained.Furthermore,the design variables of the blade mold are optimized.The arrangement of the heating wire adopts the redesign method,mixing the recirculation arrangement and the comb arrangement to obtain the hybrid arrangement;According to the influence of the design variables of the blade mold on the thermal conductivity of the mold,the corresponding design range is determined,and the design variables of the blade mold are optimized and analyzed using the Parameter Set module.Final,a design plan for the blade mold to have the best heat conduction effect is obtained,thereby the improvement of the blade mold structure is realized.Finally,an electric heating mold test model was built,tested and verified.According to the optimal solution obtained,the electric heating blade mold model was constructed.After the heating was completed,the actual temperature of the optimized blade mold was measured,and the actual temperature was compared.The results show that the maximum temperature difference between the cavity surface of the optimized blade mold is reduced about 53%,and the maximum surface temperature reaches the minimum requirement(69℃).The error between the actual measured temperature and the finite element analysis temperature is about 10%.Within the acceptable range,the optimization scheme is feasible. |
PDF Full Text Request