一种基于实测混凝土温度梯度获取表面散热系数的新方法

混凝土表面散热系数计算的准确与否,会对温度仿真计算的可靠性产生很大影响。通过现场试验研究了不同边界条件下温凝土表面附近点温度和温度梯度随距临空面距离和时间的变化规律,利用现场温度实测值对混凝土表面散热系数进行反演分析,得到不同边界下混凝土表面散热系数的反演值。然后通过混凝土第三类边界条件下表面散热系数与温度梯度的关系,发现可以选取混凝土表面0.03 m~0.09 m范围内的中点温度和温度梯度计算混凝土表面散热系数。几种不同表面覆盖条件下的验证计算结果表明,该方法对于不同的边界具有普适性和较好的准确性,可供科研人员和设计人员参考。

A new method for concrete surface coefficient of heat transfer based on the measured temperature gradient

The accuracy of the concrete surface coefficient of heat transfer, will produce a great impact on the reliability of the simulation calculation for temperature. In this paper, different boundary conditions are studied through field experiment to get the rules of point temperature and temperature gradient near the sur-face of the concrete varying with distance from the concrete surface to the point and time. With field mea-sured temperature, inversion analysis is carried out on the concrete surface coefficient of heat transfer and get the inversion value of the concrete surface coefficient of heat transfer under different boundaries, then based on the relationship between concrete surface coefficient of heat transfer and the temperature gradient under boundary condition of the third kind, find that the midpoint temperature and temperature gradient within the scope of 0.03 m to 0.09 m can be used to estimate concrete surface coefficient of heat transfer. The validation results under different surface conditions show that the method for different boundaries has universality and better accuracy,to provide a reference for the researchers and designers.