内插梯形挡板的交叉三角形波纹板流道的流动与传热研究

Study on heat transfer and flow characteristics of cross-corrugated triangular ducts with trapezoidal baffles

内插挡板可以强化交叉三角形波纹流道的传热。为此,本文研究了内插梯形挡板的交叉三角形波纹板流道的流动与传热。应用RSM模型对基于梯形挡板的交叉三角形波纹板流道进行数值研究,对内插不同挡板的流道流场和温度场进行分析,比较不同的梯形挡板对摩擦因子f、努塞尔数及综合传热指标PEC的影响。研究结果表明:梯形挡板增强了流体的扰动,促进了流体的混合,使流域内的温度分布更均匀,流道的努塞尔数和f因子均有提高。梯形挡板流道的综合传热性能均比无挡板流道的综合传热性能要好。综合传热性能最好的是上底和下底宽度分别为3/4W和W的梯形挡板,在Re=1100时具有最高综合传热指标值PEC_(max)=1.3。最后根据模拟计算结果,整理了Re与PEC的关联式供板式换热器流道设计参考。

Cross-corrugated triangular ducts with baffles can enhance the heat transfer.The flow and heat transfer of crosscorrugated triangular ducts with added trapezoidal baffles are studied.A RSM model is applied to numerically simulate the flow and heat transfer of cross-corrugated triangular ducts based on trapezoidal baffles,analyze the flow field pattern and temperature field pattern,and compare the effects of different trapezoidal baffles on friction factor f,Nusselt number and combined heat transfer index PEC.The results show that the trapezoidal baffles enhance disturbance of the fluid,promote fluid mixing,making the temperature in the flow domain distributed more uniformly.Both the Nusselt number and f factor of the flow passage are improved.The combined heat transfer performance of the ducts with trapezoidal baffles all is better than that of the ducts without baffles.Among them,the ducts with trapezoidal baffles whose upper and lower base being 1/4 and 3/4 corrugation width,respectively,has the best combined heat transfer enhancement effect.When Re=1100,it possesses the best combined heat transfer performance,and the maximum of PEC is 1.3.Finally,according to the simulation results,the correlation between Re and PEC is sorted out,which provides a reference for design of plate type heat exchangers.