通过对表面式空气冷却器管内换热机理的分析，提出了分段计算换热系数的计算方法．该计算方法能够较真实地反映各段的放热规律，较准确地描述各换热段换热效率的大小，从而使整个蒸发器的设计得到优化．以某空调系统中蒸发器为例证明该计算方法的合理性． Based on the analysis of the heat transfer mechanism in the surface air cooler, a method of calculating the heat transfer coefficient by section is proposed. The calculation method can more accurately reflect the exothermic laws of each section, and accurately describe the heat exchange efficiency of each heat exchange section so as to optimize the design of the entire evaporator. Taking the evaporator in an air-conditioning system as an example, the rationality of the calculation method is proved.