横纹槽管内插扭带复合强化传热的试验研究

Experimental Study on Compound Heat Transfer Enhancement of Transverse Corrugated Tube with Full Length Twisted Tapes

不同强化传热方式的复合会产生不同的传热效果,通过试验将不同扭率的扭带与同一规格横纹槽管复合强化传热的效果进行对比。试验以高黏度的导热油为工质,

The different mode of compound heat transfer enhancement leads to different transfer effect. Experimental studies of comparison between different compound transfer enhancement effects on transverse corrugated（TC） tube with full-length twisted tapes of different twist ratios have been conducted with oil of high viscosity. The variation of Nusselt number and resistance coefficient with Reynolds numbers are presented, and then correlation for Nusselt number and resistance coefficient are obtained by a multivariable linear regression analysis in the range of 500〈Re〈7 000,50〈Pr〈180. Comprehensive heat transfer performance is evaluated by the value of performance evaluation criteria. As compared with smooth tubes with full-length twisted tapes, the resistance coefficient of TC tubes with full-length twisted tape inserts can be increased by 2-5 times, the Nu can be increased by 1-4 times. With the increasing of Re, the twist ratios are less able to influence the Nu. Values of PEC of TC tubes with full-length twisted tape inserts in proportion of Re and in inverse proportion of twist ratios on the condition of laminar flow. Under the condition of transition flow, the values in inverse proportion of Re. In addition, TC tube with twisted tape of Y=5.21 inserts has better comprehensive heat transfer performance than the others.