斜针翅管强化传热管的数值模拟

Numerical Simulation of Enhanced Heat Transfer Tube with Inclined-Pin Fin Tube

采用Fluent软件,以水和柴油为换热对象,利用三维模型对柴油在3种不同规格的直针翅管、30°和45°的斜针翅管套管换热器壳程层流流动时的温度场、压降及传热性能进行了模拟;并将斜针翅管与光滑管和直针翅管的结果进行比较。模拟结果表明,壳程为柴油时,针翅管的压降为光滑管的1～3倍,总传热系数约是光滑管的1.7～2.7倍;与直针翅管相比,斜针翅管的总传热系数提高约20%;斜针翅能使传热膜的系数增大,压降降低。

Numerical simulations was conducted by using three-dimensional model of Fluent software for the case that hot water was flowing in tube side of the heat exchanger and diesel oil as heat-transfer medium was flowing in shell side. Temperature field and heat transfer performances in shell side of a single-tube heat exchanger with three different kinds of fins and with different specifications were simulated. They were straight-pin fin tube, inclination angle of 30° and 45°- inclined-pin fin tubes. Pressure drop with pin-finned tubes were about 1 -3 times greater than that with plain tube at same flow conditions. Heat transfer enhancements of pin-finned tube heat exchangers were about 1.7 - 2.7 times greater than those of plain tube heat exchangers. Compared with straight-pin fin tube, the inclined-pin fin tubes can improve over-all heat transfer coefficient by 20% at most. At the same time it is proved that inclined-pin fin tubes can further enhance film coefficient of heat transfer and lower the pressure drop as compared with the straight-pin fin tube.