一种改进型曲面涡产生器在管翅式换热器中的数值研究

Numerical Study of an Improved Curved Rectangular Vortex Generator in Fin-and-tube Heat Exchanger

为了探究提出的改进型曲面涡产生器对换热器换热和流动特性的影响,采用数值仿真方法,对改进型曲面涡产生器翅片和改进前翅片在对换热器换热和流动特性上的影响进行比较分析,并且探究了不同曲面涡产生器偏移距离对传热特性的影响.结果表明,改进型曲面涡产生器能够改善尾涡区流动状态,增强二次流的形成;与改进前的结构相比,改进型曲面涡产生器的Num和f均增大.通过对L和JF因子的比较,改进型的曲面涡产生器具有较优的综合强化传热能力,在较大Re数时,偏移距离OD=1.5mm的曲面涡产生器具有更好的综合传热性能.

In order to investigate the influence of the improved curved rectangular vortex generator (CRVG) on the heat transfer and flow characteristics of the fin-and-tube heat exchanger, a numerical simulation method was used to compare and analyze the influence of the improved curved vortex generator fin and unmodified fin on heat transfer and flow characteristics of heat exchanger. The influence of offset distance of different curved vortex generators on heat transfer characteristics was also investigated. The results show that the improved curved vortex generator can improve the flow state of wake vortex region and enhance the formation of secondary flow. Compared with the structure before improvement, the Num and f of the improved CRVGs are both increased. Through the comparison of L and JF factors, it is found that the improved CRVG has better comprehensive heat transfer enhancement ability, and that the CRVGs with 1.5 mm offset distance has better comprehensive heat transfer performance as the Re increases.