For plate quenching on a roller quenching machine, heat transfer process is investigated. According to the practical online experiment of plate center temperature, average heat transfer coefficient under different con...For plate quenching on a roller quenching machine, heat transfer process is investigated. According to the practical online experiment of plate center temperature, average heat transfer coefficient under different conditions and temperature fields are analyzed by numerical simulation. The results show that, at the water temperature of 15 ℃, the instantaneous maximum quenching cooling rate is 17.6 ℃/s for the plate of 50 mm in thickness in roller quenching process. In the temperature range of 400-850 ℃, the maximum is 12.1 ℃/s. With the plate surface temperature decreasing, surface heat transfer coefficient increases at first, and reaches the maximum value of about 15 000 W/（m^2·K）, and then decreases. The calculated heat transfer coefficients are applied to analyze plate temperature field of different thicknesses, and the difference between the calculated and measured temperature is less than 5%.展开更多
Three-dimensional finite element flow field model of spraying pipe of roller-type quenching machine is built.The flow field with different structural parameters is computed.After grouping the nozzles,the spraying unif...Three-dimensional finite element flow field model of spraying pipe of roller-type quenching machine is built.The flow field with different structural parameters is computed.After grouping the nozzles,the spraying uniformity is analyzed under the conditions of different water inlet pipe diameter,different water inlet pipe distance,nozzle diameter and nozzle distance.And the spraying intensity absolute deviation and relative deviation are computed under different conditions.The effect of different structural parameters on cooling uniformity is obtained.The results provide theoretical basis for improving production quality and optimizing cooling device design.展开更多
基金Sponsored by National Basic Research Program(973 Program) of China(2010CB630800)
文摘For plate quenching on a roller quenching machine, heat transfer process is investigated. According to the practical online experiment of plate center temperature, average heat transfer coefficient under different conditions and temperature fields are analyzed by numerical simulation. The results show that, at the water temperature of 15 ℃, the instantaneous maximum quenching cooling rate is 17.6 ℃/s for the plate of 50 mm in thickness in roller quenching process. In the temperature range of 400-850 ℃, the maximum is 12.1 ℃/s. With the plate surface temperature decreasing, surface heat transfer coefficient increases at first, and reaches the maximum value of about 15 000 W/（m^2·K）, and then decreases. The calculated heat transfer coefficients are applied to analyze plate temperature field of different thicknesses, and the difference between the calculated and measured temperature is less than 5%.
文摘Three-dimensional finite element flow field model of spraying pipe of roller-type quenching machine is built.The flow field with different structural parameters is computed.After grouping the nozzles,the spraying uniformity is analyzed under the conditions of different water inlet pipe diameter,different water inlet pipe distance,nozzle diameter and nozzle distance.And the spraying intensity absolute deviation and relative deviation are computed under different conditions.The effect of different structural parameters on cooling uniformity is obtained.The results provide theoretical basis for improving production quality and optimizing cooling device design.
