倾斜折流栅式换热器壳程热力特性研究

Research on Thermodynamic Characteristic of Heat Exchanger's Shell Side with Inclined Shutter Baffles

为提升常规斜向流换热器的壳程传热性能,提出了一种倾斜折流栅式换热器。采用CFD分析软件FLUENT,标准k-ε模型方程对两种斜向流换热器的壳程热力特性进行了数值研究,并运用场协同原理分析了斜向流换热器的强化传热机理。结果表明:随着折流栅倾斜角的降低,壳程传热系数、压降、综合性能升高,但随着倾斜角的继续降低,如在(60~70)°范围内,壳程传热系数和综合性能基本保持不变;倾斜折流栅式换热器能够提高壳程局部纵向流场的流速,增加壳程流体整体的斜向流程度和速度场与温度场的协同性,强化换热。倾斜角为70°时,倾斜折流栅式换热器较常规斜向流换热器壳程传热系数和综合性能分别提高(7.54~7.66)%和(6.29~6.45)%。研究结果为斜向流换热器的结构优化和推广应用提供了理论依据。

To improve the shell side heat transfer performance of the conventional sideling flow heat exchanger,a kind of sideling flow heat exchanger with inclined shutter baffles was put forward. With CFD analysis software FLUENT and standard k-ε model equation,the shell side thermodynamic characteristic of both sideling flow heat exchangers were investigated numerically,and the heat transfer enhancement mechanisms of heat exchangers were studied with field synergy principle. The results show that the shell side heat transfer coefficient,pressure drop,and comprehensive performance raise with the decrease of shutter baffle inclination angle,while the shell side heat transfer coefficient and comprehensive performance remain the same when the inclination angle continues to reduce,such as in the range of（60～70）°;The shell side local horizontal flow velocity raises by using inclined shutter baffle,the intensity of overall sideling flow and the cooperativity of the shell side velocity field with temperature field increase too,and the heat transfer performance is enhanced. The heat transfer coefficient and comprehensive performance of the inclined shutter baffle heat exchanger with angle of 70° increase by（7.54～7.66）% and（6.29～6.45）% respectively when compared with the conventional sideling flow heat exchanger. The results provide the reference for the structure optimization and application of sideling flow heat exchangers.