板翅式换热器换热效能三元线性回归模型及其系数辨识

针对系统仿真需要,忽略壁面导热热阻和流体物性参数变化,推导出一定对流换热准则形式下,板翅式换热器传热单元数(NTU)与两种流体介质质量流量间的三元线性回归模型。利用少量换热器性能试验数据,以MATLAB内嵌最小二乘法可准确确定该模型系数,进而获得换热效能曲面。对比研究结果表明:该模型不仅试验数据少、拟合精度高,且具有一定的鲁棒性;即使不能准确知道换热器结构参数或传热因子的拟合公式,也能利用少量性能试验数据合理给出换热效能曲面,解决系统仿真研究时换热器模型参数的输入难题。

A Ternary Linear Regression Model and Its Coefficients Identification of Heat Transfer Efficiency for Plate-fin Heat Exchanger

In view of the requirements of system simulation,a ternary linear regression model of a plate-fin heat exchanger is developed between the number of transfer units(NTU) and mass flow rates of the fluid of the two sides under certain convective heat transfer criteria while ignoring the wall thermal resistance of the heat exchanger and the variation of the fluid thermo-physical properties.Based on a few heat exchanger performance test data,the model coefficients can be accurately determined by the least squares method embedded in MATLAB.And then the efficiency surface of the heat transfer can be easily obtained.Comparative study results show that the model needs only a little experimental data,and has a high fitting accuracy and certain robustness.Even if the heat exchanger structure properties or the fitting formulas of heat transfer factor are not accurately known,a reasonable efficiency surface of the heat exchanger can be obtained by using a small amount of test data.These results can help solve the difficulties of parameter input of a heat exchanger model in system simulation.