表面综合换热系数的热传导反算方法研究

Estimation of Synthesized Heat-transfer Coefficient by Heat Conduction Reversed Calculation

详细介绍了非线性估算的计算模型和原理,并采用Matlab软件进行编程。为验证非线性估算法的准确性,以淬火热处理为例,采用预设的表面综合换热系数计算工件的瞬态温度场,得到反算所需的测温点降温数据,并将反算结果与预设的换热系数值进行比较。研究表明,非线性估算法可以准确计算出实际换热系数的变化趋势,且两者的数值也较为接近。而且,用反算的换热系数计算得到测温处的降温曲线与实际降温曲线的拟合度较高,进一步证明了非线性估算法的准确性。

The paper introduces the computational model and principle of nonlinear estimation and the program that is made by using Matlab software for it. In order to verify the accuracy of the nonlinear estimation, the paper takes quenching treatment for instance to calculate the transient temperature field of the quenched part with preset surface synthesized heat-transfer coefficient and obtain temperature-drop data at temperature measuring points needed by reversed calculation. The comparison of the reversed calculation results to the preset heat transfer coefficient reveals that the nonlinear estimation can calculate the variation trend of actual heat transfer coefficients and the preset coefficients are almost same with the actual coefficients.Furthermore, the temperature-drap curve that is made with reversed-calculated heat transfer coefficients has high degree of fit to the actual temperature-drop curve, which proves the accuracy of the nonlinear estimation in further.