CAJ | 학술논문

通过对倾斜角35°首尾相连的三分螺旋折流板换热器的数值模拟，展示了其壳侧通道内流体在典型切面上的流场和流线分布，以及典型切面上典型直线的流动和换热参数分布，并与性能测试结果进行了对比。结果表明，数值模拟结果与实验结果是吻合的。螺旋折流板形成的近似螺旋通道，使换热器壳侧流体受离心力和向心力共同作用形成了迪恩涡二次流，且在每个螺旋周期内都存在；二次流增强了主流区域流体与靠近壁面流体的掺混，使得壳侧典型切面上中心线和折流板外缘直线的轴向速度较大；除主流中心区域外，壳侧流体在二次流的作用下具有均匀的湍流动能；二次流所在区域内，壳侧同心柱面内典型直线上换热系数相差不大，但由于二次流能使其附近区域传热面上的流体得到不断卷吸掺混，由此强化传热。
통과대경사각35°수미상련적삼분라선절류판환열기적수치모의，전시료기각측통도내류체재전형절면상적류장화류선분포，이급전형절면상전형직선적류동화환열삼수분포，병여성능측시결과진행료대비。결과표명，수치모의결과여실험결과시문합적。라선절류판형성적근사라선통도，사환열기각측류체수리심력화향심력공동작용형성료적은와이차류，차재매개라선주기내도존재；이차류증강료주류구역류체여고근벽면류체적참혼，사득각측전형절면상중심선화절류판외연직선적축향속도교대；제주류중심구역외，각측류체재이차류적작용하구유균균적단류동능；이차류소재구역내，각측동심주면내전형직선상환열계수상차불대，단유우이차류능사기부근구역전열면상적류체득도불단권흡참혼，유차강화전열。
Using the numerical simulation of end to end tube-and-shell heat exchangers with trisection helical baffles with 35°inclined angle, this research demonstrated the distribution of the flow field and streamline on the typical sections of fluid in the shell side channel, as well as the distribution of flow and heat transfer parameters of typical straight lines on the typical sections. The results showed that the approximate spiral channel composed by helical baffles impelled the Dean vortex secondary flow formed by the combined effect of centrifugal and centripetal force, and the Dean vortex secondary flow existed in each spiral cycle. the secondary flow enhanced the mixing of fluid in mainstream region and fluid near the wall, resulting a larger axial velocity of the centerline and the outer edge straight line on the typical sections. Other than the mainstream center region, the shell side fluid had uniform turbulent kinetic energy in the role of secondary flow. The heat transfer coefficient on the concentric cylindrical surface differed little in the secondary flow region,however, heat transfer can be enhanced due to the fact that the secondary flow was continuously entraining the fluid of the adjacent areas.