Abstract: Correlation regression methods for heat exchanger have been developed in last several years, such as the method based on equal flow Reynolds number, the method based on equal flow velocity, and the Wilson plot technique, improvements of which contribute outstandingly in measuring heat transfer equipment. The defect in those methods is as follows. The methods based on equal flow Reynolds number and flow velocity restrict the flow conditions, duct structure and flow media in two ducts. The Wilson plot technique demands the exponent of Reynolds number. A new method is presented in this paper, which is similar to the Wilson plot technique but avoid above restrictions through searching proper coefficient and exponent in the correlation by examining the minimum variance in different fitting consequence, giving accurate heat transfer coefficients on the fixed side. The relation between two ducts is the thermal resistances in series. The method resolves the correlation fitting technique with a dichotomy, which is more accurate than linear regression analysis commonly used. The method is validated by simulated data first and then by experimental data. The result shows that the method is reasonable.

Key words: heat transfer, correlation regression, overall heat transfer coefficient

摘要： 目前换热器测试中的回归方法对测量过程和测试对象的要求仍有很多限制条件,对于换热管形状复杂的新型换热设备进行回归时,这些限制使获得准则方程式更加困难,测量周期增加.通过提出一种新的回归算法,以最小方差作为回归条件直接得到固定侧表面传热系数以及改变侧准则方程式,避免了Wilson法及等流速法等需要的限制条件.该方法仅依赖于对流换热两侧的热阻串联关系,得到的准则式与两侧流体工质、通道形态及流动状态是否相同均没有关系,降低了得到准则方程式的条件并简化测量过程,且与国家标准要求的测试条件对应.发展了使用二分法进行非线性回归得到准则方程式的算法,通过生成并使用模拟数据检验表明算法是准确可行的,使用实验数据求解得到的固定侧表面传热系数和流动侧准则方程指数也在合理的范围内.

关键词: 传热, 准则式回归, 总传热系数