Thermal hydraulic performance of 10 PPI aluminium foam as alternative for louvered fins in an HVAC heat exchanger

Abstract In this paper, two heat exchangers for an HVAC application are compared. The first one is a commercially available high quality louvered fin heat exchanger, while the second heat exchanger is a prototype in-house made using 10 PPI open-cell aluminium foam. Heat transfer and pressure drop measurements were performed in a wind tunnel with free stream air velocities between 1.1 and 3.1 m/s. The comparison between both heat exchangers is done based on a well-defined performance evaluation criterion for foam. It is revealed that the heat exchangers have a similar performance at low air velocity (1.1 m/s), while the louvered fin heat exchanger performs slightly better at higher velocities. Furthermore, the influence of the contact resistance is studied based on literature. The pressed-fit foam heat exchanger experiences very high contributions of the contact resistance (up to 70% of the overall thermal resistance), while for the louvered fin heat exchanger this contribution is much smaller (up to 11.1%), due to the presence of a fin collar. When comparing the airside convective resistance only, the foam heat exchanger performs better at high velocity range (2.5–3.1 m/s). The influence of changing the bonding technology is also assessed. It is demonstrated that a hypothetical brazed metal foam coil should have a same performance than the louvered fin unit at a low velocity range (1.1–2.5 m/s).

[1]  M. Bahrami,et al.  Thermal conductivity and contact resistance of metal foams , 2011 .

[2]  D. Bouris,et al.  3D numerical simulation of flow and conjugate heat transfer through a pore scale model of high porosity open cell metal foam , 2010 .

[3]  R. Pitz-Paal,et al.  Macroscopic foam model with effective material properties for high heat load applications , 2012 .

[4]  P.S. Liu.  A new method for calculating the specific surface area of porous metal foams , 2010 .

[5]  A. London,et al.  Compact heat exchangers , 1960 .

[6]  D. P. Sekulic,et al.  Fundamentals of Heat Exchanger Design , 2003 .

[7]  Howard P. Hodson,et al.  The temperature dependence of effective thermal conductivity of open-celled steel alloy foams , 2004 .

[8]  N. Dukhan.  Correlations for the pressure drop for flow through metal foam , 2006 .

[9]  Indrani Ghosh.  Heat transfer correlation for high-porosity open-cell foam , 2009 .

[10]  A. Razani,et al.  Self-Consistent Open-Celled Metal Foam Model for Thermal Applications , 2006 .

[11]  Chi-Chuan Wang,et al.  Heat transfer and friction characteristics of plain fin-and-tube heat exchangers, part II: Correlation , 2000 .

[12]  Simon Kuhn,et al.  Large eddy simulation of flow through a streamwise-periodic structure , 2011 .

[13]  Jonathan Rose,et al.  Heat-transfer coefficients, Wilson plots and accuracy of thermal measurements , 2004 .

[14]  Henk Huisseune.  Performance evaluation of louvered fin compact heat exchangers with vortex generators , 2011 .

[15]  M. D. Paepe,et al.  Determination of heat transfer and friction characteristics of an adapted inclined louvered fin , 2006 .

[16]  Henk Huisseune,et al.  Study of junction flows in louvered fin round tube heat exchangers using the dye injection technique , 2010 .

[17]  Roop L. Mahajan,et al.  Finned Metal Foam Heat Sinks for Electronics Cooling in Forced Convection , 2002 .

[18]  R. K. Shah,et al.  Compact Heat Exchangers for Microturbines , 2005 .

[19]  Henk Huisseune,et al.  Assessing the influence of four bonding methods on the thermal contact resistance of open-cell aluminum foam , 2012 .

[20]  L. Valdevit,et al.  Active cooling by metallic sandwich structures with periodic cores , 2005 .

[21]  M. Velez-Reyes,et al.  One-dimensional heat transfer analysis in open-cell 10-ppi metal foam , 2005 .

[22]  Michel De Paepe,et al.  Experimental Determination of the Heat Transfer Coefficient of a Plate-Fin Heat Exchanger , 2005 .

[23]  M. De Paepe,et al.  Performance Prediction of Compact Fin-and-Tube Heat Exchangers in Maldistributed Airflow , 2007 .

[24]  Henk Huisseune,et al.  Mean flow and thermo-hydraulic behaviour in inclined louvered fins , 2011 .

[25]  Kevser Dincer,et al.  Experimental investigation of thermal performance of aluminum finned heat exchangers and open-cell aluminum foam heat exchangers , 2012 .

[26]  Jing He,et al.  Air-Side Heat-Transfer Enhancement by a New Winglet-Type Vortex Generator Array in a Plain-Fin Round-Tube Heat Exchanger , 2010 .

[27]  A. Nakayama,et al.  Heat transfer performance assessment for forced convection in a tube partially filled with a porous medium , 2012 .

[28]  P. Magnico.  Analysis of permeability and effective viscosity by CFD on isotropic and anisotropic metallic foams , 2009 .

[29]  W. Wagner,et al.  The IAPWS Formulation 1995 for the Thermodynamic Properties of Ordinary Water Substance for General and Scientific Use , 2002 .

[30]  H. S. Kasana,et al.  Computational aspects of effective thermal conductivity of highly porous metal foams , 2004 .

[31]  Predrag Stojan Hrnjak,et al.  Experimental investigation of thermal contact resistance in plain-fin-and-tube evaporators with collarless fins , 2003 .

[32]  Robert J. Moffat,et al.  Describing the Uncertainties in Experimental Results , 1988 .

[33]  Anthony M. Jacobi,et al.  Impact of leading edge delta-wing vortex generators on the thermal performance of a flat tube, louvered-fin compact heat exchanger , 2005 .

[34]  Mostafa Odabaee,et al.  Metal foam heat exchangers for heat transfer augmentation from a tube bank , 2012 .

[35]  K. Leong,et al.  Numerical and experimental study of forced convection in graphite foams of different configurations , 2010 .

[36]  Changying Zhao.  Review on thermal transport in high porosity cellular metal foams with open cells , 2012 .

[37]  Henk Huisseune,et al.  An experimentally validated and parameterized periodic unit-cell reconstruction of open-cell foams , 2011 .

[38]  J. Banhart.  Manufacture, characterisation and application of cellular metals and metal foams , 2001 .

[39]  H. Hodson,et al.  Thermal Transport Phenomena in Porvair Metal Foams and Sintered Beds , 2001 .

[40]  Jenn-Jiang Hwang,et al.  Measurement of interstitial convective heat transfer and frictional drag for flow across metal foams , 2002 .

[41]  J. Demuynck,et al.  Numerical Study of Flow Deflection and Horseshoe Vortices in a Louvered Fin Round Tube Heat Exchanger , 2012 .

[42]  Dimos Poulikakos,et al.  Metal foams as compact high performance heat exchangers , 2003 .

[43]  A. Jacobi,et al.  A Comparison of Metal-Foam Heat Exchangers to Compact Multilouver Designs for Air-Side Heat Transfer Applications , 2012 .

[44]  Henk Huisseune,et al.  Combined Experimental and Numerical Flow Field Study of Inclined Louvered Fins , 2011 .

[45]  M. D. Paepe,et al.  Thermo-hydraulic study of a single row heat exchanger consisting of metal foam covered round tubes , 2010 .

[46]  Henk Huisseune,et al.  Thermal hydraulic study of a single row heat exchanger with helically finned tubes , 2010 .

[47]  Byung Ha Kang,et al.  Flow and heat transfer correlations for porous fin in a plate-fin heat exchanger , 2000 .

[48]  F. Huet,et al.  Experimental characterization of flow regimes in various porous media—II: Transition to turbulent regime , 1998 .

[49]  A. Jacobi,et al.  Experimental Studies to Evaluate the Use of Metal Foams in Highly Compact Air-Cooling Heat Exchangers , 2010 .

[50]  Chang Nyung Kim,et al.  A study on the thermal contact conductance in fin–tube heat exchangers with 7 mm tube , 2006 .

[51]  Akira Nagashima,et al.  Viscosity and thermal conductivity of dry air in the gaseous phase , 1985 .

[52]  Chang Nyung Kim,et al.  Evaluation of thermal contact conductance using a new experimental-numerical method in fin-tube heat exchangers , 2003 .

[53]  Chi-Chuan Wang,et al.  Heat transfer and friction correlation for compact louvered fin-and-tube heat exchangers , 1999 .

[54]  David Edouard,et al.  Pressure drop modeling on SOLID foam: State-of-the art correlation , 2008 .

[55]  R. Haghighi-Khoshkhoo,et al.  Air-Side Fouling of Compact Heat Exchangers for Discrete Particle Size Ranges , 2007 .

[56]  F. Topin,et al.  Flow Laws in Metal Foams: Compressibility and Pore Size Effects , 2008 .

[57]  D. Seguin,et al.  Experimental characterisation of flow regimes in various porous media—I: Limit of laminar flow regime , 1998 .

[58]  N. Dukhan,et al.  Heat Transfer Analysis in Metal Foams With Low-Conductivity Fluids , 2006 .

[59]  Claudio Zilio,et al.  Foam height effects on heat transfer performance of 20 ppi aluminum foams , 2012 .

[60]  W. Tao,et al.  Numerical study of conjugated heat transfer in metal foam filled double-pipe , 2010 .

[61]  Wei-Mon Yan,et al.  HEAT TRANSFER AND FRICTION CHARACTERISTICS OF FIN-AND-TUBE HEAT EXCHANGERS , 2000, Proceeding of Proceedings of Symposium on Energy Engineering in the 21st Century (SEE2000) Volume I-IV.

[62]  K. Vafai,et al.  A synthesis of fluid and thermal transport models for metal foam heat exchangers , 2008 .

[63]  Heat Exchanger Behavior in Non Uniform Flow , 2006 .

[64]  Yorwearth L. Jamin,et al.  Natural Convection Heat Transfer Enhancements From a Cylinder Using Porous Carbon Foam: Experimental Study , 2008 .

[65]  C. Balaji,et al.  Experimental investigation of flow assisted mixed convection in high porosity foams in vertical channels , 2011 .

[66]  A. Bejan,et al.  Heat transfer handbook , 2003 .

[67]  A. Jacobi,et al.  A Review of Metal Foam and Metal Matrix Composites for Heat Exchangers and Heat Sinks , 2012 .

[68]  A. T. Prata,et al.  Performance of microchannel condensers with metal foams on the air-side: Application in small-scale refrigeration systems , 2012 .

[69]  José Fernández-Seara,et al.  A general review of the Wilson plot method and its modifications to determine convection coefficients in heat exchange devices , 2007 .

[70]  J. Eaton,et al.  A Method for Determining the Heat Transfer Properties of Foam-Fins , 2009 .

[71]  Anthony M. Jacobi,et al.  Rational approaches for combining redundant, independent measurements to minimize combined experimental uncertainty , 2010 .

[72]  Bengt Sundén,et al.  Foam Heat Exchangers: A Technology Assessment , 2012 .

[73]  A. Tamayol,et al.  Impact of Particulate Deposition on the Thermohydraulic Performance of Metal Foam Heat Exchangers: A Simplified Theoretical Model , 2012 .