Search

Due to the huge volume， complex structure and end effect of wind power gear， it is difficult to realize the uniform heating of tooth profile and tooth width， which affects the final strengthening quality. In this paper， the average temperature， the maximum temperature difference and the relative temperature fluctuation rate are taken as the evaluation indexes of the heating effect. The temperature fields along the tooth profile and the tooth width direction of wind power gear in the scanning induction heating process are studied， and the phase transformation and hardening of the gear are analyzed. It is found that the temperature uniformity increases gradually in the direction of tooth width from top to bottom within a certain range， which is due to the drastic change of tooth structure thickness. To gears strengthened by induction hardening in steady-state positions， the depth of hardened layer in the direction of tooth profile is almost the same as the depth of macroscopic phase change layer， and the transition region is relatively narrow. The heating effect and strengthening result of gear scanning induction heating are expounded， which provides the research foundation for the wide application of high-performance steel materials in the field of wind power. [ABSTRACT FROM AUTHOR]

In order to solve the problem of poor molding quality of CFRP (carbon fiber reinforced polymer) caused by the system' s weak anti-interference, slow response speed during the induction heating of CFRP, a Fuzzy-Pill algorithm based on improved particle swarm optimization ( IPF-PID) was proposed. IPF was used to optimize and self-adjust the three parameters of Pill. The algorithm combines the advantages of PSO and Fuzzy-Pill algorithm, while avoiding falling into the local optimum, it ensures the control accuracy and the best optimization performance. The results show that the algorithm used to enhance the adaptive ability of the controller and reduce the adjustment time has a significant effect. Compared with the traditional Pill algorithm, it has smaller overshoot and steady-state error, and it is more suitable for induction heating CFRP temperature control system. [ABSTRACT FROM AUTHOR]

A new induction heating method was proposed for tundish and three kinds of side-type electromagnetic induction heaters were designed. The distribution of electromagnetic force of heaters， and its effects on flow field and temperature distribution in tundish were studied by numerical simulation. The optimal heater and heating power was obtained by analyzing the RTD (residence time distribution) curve. The results show that the flow field and temperature distribution of the molten steel in the tundish are improved by moving electromagnetic induction heater towards the end of the tundish. With the same heating power， the heating effect of the U-type heater is superior to E-type heater， and compared with bilateral and symmetrical distribution of U-type heater， the unilateral U-type heater has a better thermal efficiency. Increasing the induction heating power is beneficial to improve the flow of molten steel and improve the quality of the casting. For a four-strand tundish， the heating power of 800~1000kW is enough to compensate the heat loss. [ABSTRACT FROM AUTHOR]

The calculation model for deformation between wires was derived based on the Hertz contact theory and the structural characteristics of steel strands, and the contact area width between steel strand wires in the induction heating process was calculated with this model, which helped establish a precise finite element model for the induction heating of steel strands. Then the temperature fields in the steel strand under induction heating were simulated with the finite element method, where temperature data at different current densities and frequencies were given. Through the regression analysis of the temperature data, the average relative errors were used to evaluate the quality of several mathematical fitting models, so the optimal mathematical model for induction heating effects was found. The present work provides a theoretical basis for the control of the induction heating temperature in steel strands based on the classical control theory. [ABSTRACT FROM AUTHOR]

The global numerical simulation was performed for the YAG crystal growth with the micro-pulling-down method. The induction heating,the convection of both gas and melt and the heat transfer of solid/melt/gas were solved simultaneously. In the melt zone,buoyancy convection and thermocapillary flowwere considered. In order to uniformly discretize the controlling equations with the finite volume method,the electromagnetic field was modelled with the complex function method,and the computation of the electromagnetic field was verified with the results from the stream function method. Both the temperature and flowfields in the global furnace( including gas and melt) were investigated. As for the lowtemperature gradient at the solid-liquid interface,the effects of the afterheater was parametrically investigated. This work is useful for the optimal design of crystal growth furnaces. [ABSTRACT FROM AUTHOR]