Q—— heat flow (w)

△ tm—— Logarithmic average temperature difference (℃)

F-heat transfer area (m2)

Logarithmic temperature difference △ t = ((ti-to)-(to-ti))/ln ((ti-to)/(to-ti))

Ti: inlet temperature of hot fluid, in K.

To: outlet temperature of hot fluid, in k.

Ti: inlet temperature of cold fluid, in K.

To: outlet temperature of cold fluid, in K.