Analysis of parallel flow heat transfer(Contd) From the overall energy balance total heat transfer q=h=mn p, hTh.in-Th,out p,c(Cout Cn SO q=Ch Thin-Th ou ) and q=c cc,out CIn us and c hout c out Combining △T n ut c out C UA (△Tm-△oa) Eq.11.14 q=UA△Tmn For parallel flow △T-△T △T=T-T △T out hin h△T/△T△T=T-T out out ut C out Heat Transfer Su Yongkang School of Mechanical EngineeringHeat Transfer Su Yongkang School of Mechanical Engineering # 13 Analysis of parallel flow heat transfer (Cont’d) • From the overall energy balance, total heat transfer: thus: • Combining • For parallel flow: ( ) ( ) ( ) ( ) h h in h out c c out c in h h p h h in h out c c p c c out c in s o q C T T q C T T q q m c T T q m c T T , , , , , , , , , , : = − and = − = =  − = =  − c out c in c h in h out h T T q C T T q C , , , , and − = − = ( ) ln , , , , in out h in h out c out c in i o T T q U A q T T q T T U A T T = −  −          − + − = −   Eq. 11.14 q =UATlm i n out i n out T T T T    −   = ln / Tlm out h out c out in h in c in T T T T T T , , , ,  = −  = −