Counter Flow Heat Exchanger Formula

Lmtd with the correction factor.

Counter flow heat exchanger formula.

Where δt 1 the temperature difference between hot and cold fluids at one end of the heat exchanger δt 2 the temperature difference between hot and cold fluids at the other end of the heat exchanger. Input data in yellow update and reset funtions at bottom of page. Heat transfer q u a tm. In the parallel flow arrangement of figure 18 8 a the hot and cold fluids enter at the same end flow in the same direction and leave at the same end.

However the lmtd is valid only for heat exchanger with one shell pass and one tube pass. Plane wall heat transfer coefficient u 1 1 ho l k 1 h1. A heat exchanger can have several different flow patterns. The number of transfer units ntu method is used to calculate the rate of heat transfer in heat exchangers especially counter current exchangers when there is insufficient information to calculate the log mean temperature difference lmtd.

For multiple number of shell and tube passes the flow pattern. Crossflow parallel flow and counterflow heat exchanger configurations are three examples. The simplest heat exchanger is one for which the hot and cold fluids move in the same or opposite directions in a concentric tube or double pipe construction. A counterflow heat exchanger will require less heat exchange surface area than a parallel flow heat exchanger for the same heat transfer rate and the same inlet and outlet temperatures for the fluids.