Heat exchanger effectiveness Maximum possible heat transfer rate for any given inlet temperatures and flow rates occurs in a infinitely long counterflow HX c out out → C.7 Length of heat exchanger ·IfC<Ch,then:To=Th Cold fluid would reach hot fluid inlet t ano If Cs> Ch, then Tho=T Hot fluid would reach cold fuid inlet t and max Maximum△T max min(h. CI Heat Transfer Su Yongkang School of Mechanical EngineeringHeat Transfer Su Yongkang School of Mechanical Engineering # 5 Heat exchanger effectiveness • Maximum possible heat transfer rate for any given inlet temperatures and flow rates occurs in a infinitely long counterflow HX and : ( ) Cold fluid would reach hot fluid inlet T If max c h,i c,i c h c,o h,i q C T T C C , then: T T = − •  = T Th,out Tc,in c out h in T T , , = Length of heat exchanger and : ( ) Hot fluid would reach cold fluid inlet T If max h h,i c,i c h h,o c,i q C T T C C , then: T T = − •  = L → ( )  qmax = Cmin Th,i −Tc,i Maximum T