旋流管管内换热与阻力的实验研究

对 8根结构参数不同的旋流管的换热特性和管内阻力做了实验研究 ,给出了换热与流阻的关联式。实验中 ,水蒸气与水自成循环 ,旋流管内走冷水 ,水蒸气在管外冷凝 ,冷凝后的凝液用计量杯计量 ,通过改变旋流管内冷水流量 ,得到不同流量下的冷凝传热工况 ;阻力测量在冷态条件下进行 ,常温的水经管道流入旋流管内 ,通过测量不同流量下的压降来测定阻力。实验结果表明 ,所有旋流管的换热系数均高于光滑管 ,与同类型的其它异型强化管相比 ,旋流管传热性能更优越 ,在相同传热量下 ,旋流管的换热系数比螺旋槽纹管高 3%～ 8% ,压力损失低 5%～ 1 0 %。

Experimental investigation on heat transfer and pressure drop of spirally fluted tubes

Experiments were made for heat transfer and friction characteristic of 8 spirally corrugated tubes with various geometrical parameters. These tubes are made of copper. Statistical correlations for the friction factor and heat transfer coefficient were developed. The correlations are valid in the normalized roughness height range of 0 0291 to 0 05 and in the p/D i range of 0 4286 to 0 5833. The investigation can provide scientific basis for the design and modification of heat exchangers. The results of the experiments shows that, compared with other kinds of enhanced tubes, the spirally fluted tubes can carry out equivalent heat transfer with 3%～8% higher heat transfer coefficient and 5%～10% lower pressure loss.