内置新型双螺旋元件换热管的换热特性数值研究

Numerical Study on Heat Transfer Characteristics of Heat Exchange Tube With New Type of Double Helix Components

基于计算流体力学软件对内置双螺旋元件换热管的流动与传热性能进行数值研究。对内置不同旋向、间隙比的平行偏心扭转双螺旋元件的换热管的流动与换热进行数值模拟,结果表明,当Re≤300时,采用旋向交替布置、中间间隙比c=0.15的双螺旋元件,换热管综合性能最好,相同条件下,换热性能相比SK型螺旋元件提高2%-21%;采用结构连续且旋向相同布置、中间间隙比c=0.15的双螺旋元件,换热管综合性能最好,换热性能相比传统单扭带提高23%-56%;相同条件下两者进行对比,采用结构连续且旋向交替布置的双螺旋元件的换热效果要更好;当Re≤300时,中间间隙比为c=0.15采用旋向交替布置比采用旋向相同布置的双螺旋元件换热性能提高5%-21%。

The fluid flow and heat transfer performance of heat exchange tube with double helix twisted elements were analyzed by the CFD. The fluid flow and heat transfer of heat exchange tube with eccentric torsion and double helix elements with different rotation direction and central clearance ratios were simulated numerically. The results show that, when the Re≤300, the heat exchanger tube inserted by the double helix twisted elements with the alternated rotation and central clearance ratios c=0.15 has the best heat transfer performance which is higher by 2%-21% than heat transfer performance of SK under the same condition. The heat exchanger tube inserted by double helix elements with continuous structure and same rotation, central clearance ratios c=0.15 has the best heat transfer performance which is higher by 23%-56% than the performance of single twisted tape. And the heat transfer of double helix elements with continuous structure and alternated rotation is better than that of one with same rotation. When the Re≤300, the heat transfer of double helix twisted elements with the alternated rotation and central clearance ratios c=0.15 is higher by 5%-21% than the one with same rotation.