ASTM_D_7863_-_13.pdf

Designation:D786313Standard Guide forEvaluation of Convective Heat Transfer Coefficient ofLiquids1This standard is issued under the fixed designation D7863;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This guide covers general information,without specificlimits,for selecting methods for evaluating the heating andcooling performance of liquids used to transfer heat whereforced convection is the primary mode for heat transfer.Further,methods of comparison are presented to effectivelyand easily distinguish performance characteristics of the heattransfer fluids.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D445 Test Method for Kinematic Viscosity of Transparentand Opaque Liquids(and Calculation of Dynamic Viscos-ity)D1298 Test Method for Density,Relative Density,or APIGravity of Crude Petroleum and Liquid Petroleum Prod-ucts by Hydrometer MethodD2270 Practice for Calculating Viscosity Index from Kine-matic Viscosity at 40 and 100CD2717 Test Method for Thermal Conductivity of LiquidsD2766 Test Method for Specific Heat of Liquids and SolidsD2887 Test Method for Boiling Range Distribution of Pe-troleum Fractions by Gas ChromatographyD2879 Test Method for Vapor Pressure-Temperature Rela-tionship and Initial Decomposition Temperature of Liq-uids by IsoteniscopeD4530 Test Method for Determination of Carbon Residue(Micro Method)D6743 Test Method for Thermal Stability of Organic HeatTransfer FluidsE659 Test Method for Autoignition Temperature of LiquidChemicals3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 heat transfer fluid,na fluid which remains essen-tially a liquid while transferring heat to or from an apparatus orprocess,although this guide does not preclude the evaluation ofa heat transfer fluid that may be used in its vapor state.3.1.1.1 DiscussionHeat transfer fluids may be hydrocar-bon or petroleum based such as polyglycols,esters,hydroge-nated terphenyls,alkylated aromatics,diphenyl-oxide/biphenylblends,mixtures of di-and triaryl-ethers.Small percentages offunctional components such as antioxidants,anti-wear andanti-corrosion agents,TBN,acid scavengers,or dispersants,ora combination thereof,can be present.3.1.2 heat transfer coeffcient,na term,h,used to relatethe amount of heat transfer per unit area at a given temperaturedifference between two media and for purposes of this guide,the temperature difference is between a flow media and itssurrounding conduit.3.1.2.1 DiscussionThe heat transfer coefficient for condi-tions applicable to fluids flowing in circular conduits underturbulent flow is referred to as the convective heat transfercoefficient.4.Summary of Guide4.1 The convective heat transfer coefficient for flow in acircular conduit depends in a complicated way on manyvariables including fluid properties(thermal conductivity,k,fluid viscosity,fluid density,specific heat capacity,cp),system geometry,the flow velocity,the value of the character-istic temperature difference between the wall and bulk fluid,and surface temperature distribution.It is because of thiscomplicated interaction of variables,test results can be biasedbecause of the inherent characteristics of the heat transferapparatus,measurement methods,and the working definition1This guide is under the jurisdiction of ASTM Committee D02 on PetroleumProducts,Liquid Fuels,and Lubricants and is the direct responsibility of Subcom-mittee D02.L0.06 on Non-Lubricating Process Fluids.Current edition approved May 1,2013.Published July 2013.DOI:10.1520/D7863-13.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 for the heat transfer coefficient.Direct measurement of theconvective heat flow in circular conduits is emphasized in thisguide.4.2 This guide provides information for assembling a heattransfer apparatus and stresses the importance of providingreporting information regarding the use and operation of theapparatus.5.Significance and Use5.1 The reported values of convective heat transfer coeffi-cients are somewhat dependent upon measurement techniqueand it is therefore the purpose of this guide