H13钢喷雾冷却过程中的喷雾压力对界面传热的影响

Effects of Spray Pressure on Interfacial Heat Transfer of H13 Steel during Spray Cooling

为了准确计算压铸喷雾过程中模具温度场,模具与喷雾介质之间的界面传热系数(IHTC)是极其重要的热物性参数。进行了不同喷雾压力下的喷雾试验,记录了H13钢板整个喷雾冷却过程的温度变化。基于非线性估算法求解了不同喷雾参数下的IHTC。研究了喷雾冷却过程中的界面形貌及传热特性,并讨论了喷雾压力对IHTC的影响。结果表明,界面可分为湿区和干区,其中前者会显著影响界面传热行为。研究发现,高喷雾压力对提高IHTC的峰值有积极作用,但阻碍了湿区的扩展并延长了IHTC达到峰值的时间。

To accurately calculate the mould temperature field during the spray process of die casting process,the interfacial heat transfer coefficient(IHTC) between the mould and the spray medium is an extremely important thermo-physical parameter.A spray experiment was conducted with different spray pressures,in which the temperature history throughout the spray cooling process of H13 steel plate was recorded.The IHTC at the different spray pressures was calculated by utilizing the nonlinear estimation method.The interface morphology and heat transfer characteristics within the spray cooling process were investiagted,and the influence of spray pressures on the IHTC was expounded.The results show that the interface can be divided into wet and dry zone,where the former significantly affects the heat transfer behavior on the interface.It is found that high spray pressure has a positive effect on improving peak IHTC,whereas it impedes the expansion of wet zone and delays the peak of IHTC.