Research On Heat Transfer And Resistance Performance Of Laminated Heat Exchanger

Laminated heat exchanger is mainly composed of finned tubes, which are similar withthe structure of air conditioning heat exchanger and manufactured by fins with stampingforming method. So laminated heat exchanger is compact, efficient and has large heat transferarea. In this paper, the heat transfer and resistance performance of laminated heat exchangerare researched by numerical simulation and experimental study. The flow and heat transfer offluid in shell are analyzed here with CFD simulation software: investigating the effect of finspacing, fin thickness, tube pitch and hole diameter on the performance of laminated heatexchanger by orthogonal design method; contrasting the characteristics of laminated heatexchanger with transverse and longitudinal flow stream. The accuracy of numericalsimulation is verified by experiment with laminated oil cooler; analyzing and comparing theheat transfer and resistance performance of laminated oil coolers with different model and oilcoolers with different structure, meanwhile reforming the laminated oil cooler. The mainconclusions are as follows:(1) Fin spacing is the most important factor to affect the pressure drop of shell andoverall performance of laminated heat exchanger, tube pitch is the most important factor toaffect the heat transfer of shell; the optimal structure is: t=3mm, P=16mm, δ=0.55mm，d=3.5mm; the correlations of Nu and f are obtained by the result of numerical simulation.(2) Contrasting the characteristics of transverse and longitudinal flow stream, it canproduce circulating fluid yet, improve the turbulence degree and enhance heat transfer thatopen holes on fin.(3) Comparing the laminated oil coolers with different model, the oil cooler g has thebest performance, while the oil cooler a has the worst performance under the experimentalcondition; also the correlations of Nu and f are obtained by the result of experiment.(4) When L/B=6.9, the heat transfer coefficient of shell unit pressure drop is the highestand the overall heat transfer performance of laminated oil cooler is the best.(5) Analyzing the oil coolers with different structures, the heat transfer coefficient ofshell unit pressure drop of laminated oil cooler is the worst, while the heat quantity unitvolume is the highest. This indicates that laminated oil cooler is compact, efficient and suitable for small flow and limited space.(6) The overall heat transfer performance of laminated oil cooler is improved afterreforming, the better performance can be obtained by increasing P/do,increasing reasonablefin ratio and opening holes.