Maximum heat flux at wetting front and velocity of the front during quenching of high temperature material temperature material

高温材料的冷却在金属加工、反应堆失水安全管理等工程领域中普遍存在。热传递强烈地依赖于表面是否被润湿，并且其值通常变化一百倍。高温物料在淬火过程中，传热过程一般由膜态沸腾经过过渡沸腾转变为核态沸腾。在本研究中，首先利用拉普拉斯变换，发展二维逆解，以估计表面温度和热通量。对新发展的求解方法在移动热源情况下的应用进行了数值检验，发现该方法能够以与固体中测量温度几乎相同的精度估算出表面温度和热流密度，进而确定移动热源的位置。黄铜和钢与冲击液体射流。实验范围见表。通过将逆解应用于该淬火，可以获得在淬火期间高温表面被润湿的位置，并且可以获得在该位置处的最大热通量。利用高速摄像机将估计位置与测量位置进行了比较，两者吻合良好。通过实验研究了液体温度、液体流速、材料热物性等因素对湿润锋速度和最大热流密度的影响。[表]

The cooling of high temperature material commonly appears in engineering field such as metal processing and safety management for loss of coolant in reactor. Heat transfer strongly depends on whether the surface is wetted or not and its values usually changes one hundred times. During quenching the high temperature material, in general, heat transfer process changes from film boiling to nucleate boiling through transition boiling. In this study, two-dimensional inverse solution is first developed using the Laplace transformation to estimate the surface temperature and heat flux. The newly developed inverse solution is numerically checked in application to the moving heat source and it is found for the solution to estimate the surface temperature and heat flux with almost the same accuracy of the measured temperature in solid and then to determine the location of the moving heat source.Experiment has been conducted to make characteristics of the wetting front velocity and heat transfer during the quench of high temperature copper, brass and steel with an impinging liquid jet. Experimental range is listed in table. By applying the inverse solution to this quench, the location at which the high temperature surface is wetted during quenching can be obtained and the maximum heat flux at this location can be obtained. The estimated location is compared with the measured position using high speed video camera, being in good agreement. The effect of liquid temperature, liquid velocity, thermal properties of material on the wetting front velocity and the maximum heat flux are made clear, experimentally.【table】