Counter Flow Heat Exchanger Formula

For multiple number of shell and tube passes the flow pattern.

Counter flow heat exchanger formula.

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. Heat transfer q u a tm. Counter parallel flow heat exchanger tube length calculation. 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.

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. The heat exchanger design equation can be used to calculate the required heat transfer surface area for a variety of specified fluids inlet and outlet temperatures and types and configurations of heat exchangers including counterflow or parallel flow. However the lmtd is valid only for heat exchanger with one shell pass and one tube pass. Lmtd with the correction factor.

Crossflow parallel flow and counterflow heat exchanger configurations are three examples. 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. In heat exchanger analysis if the fluid inlet and outlet temperatures are specified or can be determined by simple energy balance the lmtd method can. 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.