Abstract: Three dimensional numerical simulation and field synergy principle analysis were conducted with simplified periodic models for shell and tube heat exchangers with helical baffles at three helix angles(30?,40癮nd 50?),and commercial codes of GAMBIT 2.3 and FLUENT 6.3 were adopted in the simulation.It is found that Nusselt number from the model with 40? angle is the largest and the predicted average field synergy intersection angle is the smallest,which is consistent with the field synergy principle.The distribution characteristics of field synergy angles reveal that the distribution is quite uniform through whole shell side of the exchangers.The investigation on local heat transfer characteristics in different regions on the shell side shows that the heat transfer rate in the central region of the heat exchanger increases with the increase of Reynolds number.

Key words: shell and tube heat exchanger with helical baffles, periodic model, heat transfer characteristic, field synergy principle, numerical simulation

摘要： 采用商用软件GAMBIT和FLUENT对3种不同螺旋角的螺旋折流板换热器周期性模型进行了三维数值模拟计算分析。计算发现40°角模型的Nusselt数最高而平均协同角最小,结论符合场协同原理。揭示了螺旋折流板换热器内场协同角的分布特征,发现螺旋折流板换热器整场的场协同角分布相当均匀。同时,对螺旋折流板换热器内不同区域的局部换热特征进行了研究,发现中心区域的换热强度随Reynolds数逐渐增强。

关键词: 螺旋折流板换热器, 周期性模型, 换热特性, 场协同, 数值模拟