排风热回收换热器性能的数值研究

Numerical Investigation of Heat Recovery Exchanger Performance from Exhaust Air

为研究通道结构及流速对换热器性能的影响,建立了150 mm×150 mm排风热回收换热器的三维物理模型。分别针对五种不同通道结构的换热器,通过Fluent软件研究其(模型0流动及传热特性,模拟了速度场及温度场,分析了通道结构和进口流速改变,换热器的换热效率和压降的变化规律。结果表明,中间无支撑板的情况下,换热效率最好,且压降也是最小。对于矩形通道,随长宽比的增加,换热热效率略有提高,压降有所减小,其整体性能仅次于无支撑板结构。三角形通道的换热效率明显低于其它几种通道形式,且压降最大。

Three-dimensional physical models of 150 mm150 mm heat？ recovery？ exchanger？ from？ exhaust？air were established to investigate effects of tunnel structure and flow velocity on heat exchanger performance . Characteristics of flow and heat transfer in five types of tunnel structure of heat exchangers were studied by using softeare FLUENT.In addition, the velocity field and temperature distribution are obtained by numerical simula-tion.Effects of heat exchanger tunnel structure and inlet velocity on the heat exchange efficiency and pressure drop were analyzed .The results showed that heat exchange efficiency is the highest and pressure drop the lowest in case of heat exchanger without intermediate support plates .Efficiency of exchanger with rectangle tunnel struc-ture slightly improves with increase of length -width ratio , and its performance is just inferior to that without in-termediate support plates .Efficiency of exchangers with triangle tunnel is the lowest and its pressure drop is the highest.