Average temperature drop
Temperature drop averaged over the heat-transfer surface.
Comment. We distinguish between:
a) mean arithmetic temperature drop
b) mean logarithmic temperature drop
c) mean integral temperature drop
where Δt is the local temperature drop; Δt1, Δt2 are the values of the local temperature drop at the beginning and the end (in the direction of flow of the heat-transfer agent) of the heat-exchange system, F is the area of the heat transfer surface.
Heat & Mass Transfer, and Fluids Engineering