Mean Overall Heat Transfer Coefficient in Heat Exchangers Allowing for Temperature-Dependent Fluid Properties

作者：Roetzel, Wilfried^*; Luo, Xing

来源：Heat Transfer Engineering, 2011, 32(2): 141-150.

DOI：10.1080/01457631003769278

For temperature-dependent heat transfer coefficients and heat capacities, fast approximation methods are presented for the estimation of the effective overall heat transfer coefficient. The heat transfer coefficients are calculated for two, three, or four reference temperatures. For the parallel and countercurrent flow a known method is described that uses a hypothetical fluid temperature for the iteration-free consideration of variable heat capacities. For the mixed-unmixed cross flow a previous method for temperature-dependent heat transfer coefficients is refined to allow also for variable heat capacities. For the mixed-mixed cross flow a new iterative fast design and rating method is developed that is a suitable model for special multipass shell-and-tube heat exchangers. The accuracy of the methods is tested against numerical calculations with good results.

• 出版日期2011
• 单位上海理工大学