CAJ | 학술논문

振荡折流换热器广泛应用在包含传热传质过程的化工过程中，本文对管内插入螺旋翅片的振荡折流换热器进行了三维非稳态数值模拟，模拟在斯特劳哈尔数St=2，4，8和振荡雷诺数Reo=20，40，80范围内进行。通过作出瞬时三维流线，以观察流动状态随时间变化规律，发现其中有纵向涡和横向涡的周期性形成和脱落；得到了圆管周向局部传热系数随时间变化规律，以及不同振荡参数（St和Reo）下周向平均传热系数随时间的变化规律。结果表明：局部传热系数沿周向不均匀分布，并在翅片斜对面达最大；周向平均传热系数随时间周期性变化，时间平均传热系数随振幅增大而增大，但受频率影响却不明显；在本文讨论的参数范围内，平均传热系数最大可达圆管层流的4倍。
진탕절류환열기엄범응용재포함전열전질과정적화공과정중，본문대관내삽입라선시편적진탕절류환열기진행료삼유비은태수치모의，모의재사특로합이수St=2，4，8화진탕뢰낙수Reo=20，40，80범위내진행。통과작출순시삼유류선，이관찰류동상태수시간변화규률，발현기중유종향와화횡향와적주기성형성화탈락；득도료원관주향국부전열계수수시간변화규률，이급불동진탕삼수（St화Reo）하주향평균전열계수수시간적변화규률。결과표명：국부전열계수연주향불균균분포，병재시편사대면체최대；주향평균전열계수수시간주기성변화，시간평균전열계수수진폭증대이증대，단수빈솔영향각불명현；재본문토론적삼수범위내，평균전열계수최대가체원관층류적4배。
Oscillatory baffled heat exchangers (OBHEs) are widely used in chemical processes involving heat or mass transfer. OBHE with spiral fins inserted was simulated using the three dimensional unsteady method in the range of Strouhal number St=2,4,8 and oscillatory Reynolds number Reo=20,40,80. Instantaneous three dimensional stream lines were drawn to show the change of flow status with time,and periodic formation and shedding of spanwise and streamwise vortexes was observed. The changes with time of peripheral local heat transfer coefficients (HTCs)and peripherally averaged HTCs with different oscillatory parameters (St and Reo) were obtained. The local HTCs were not distributed uniformly peripherally and a maximum value was reached at the diagonally across position of fins. Peripherally averaged HTC varied with time periodically and time averaged HTC increased with increasing amplitude,but hardly changed with frequency. In the range covered by this work,averaged HTC could be four times higher than that of tube laminar flow.