Pressure Drop and Heat Transfer Analysis for Satisfactory Operating Conditions of Rotary Heat Exchangers

A computational analysis in a rotary heat exchanger subject to pre-established mass flow rate is
performed. The heat transfer rate, the pressure drop and the outlet temperatures of gas streams are
calculated from different matrix porosity values. The fluid flow and the convective heat transfer
coefficient are determined from correlations. The total heat transfer is obtained using the
Effectiveness-NTU method specific to rotary heat exchangers. Three typical rotary exchangers with
both streams under the laminar flow regime are investigated. A range of porosity values that provide
good thermal exchange and low pressure drop in the equipment is chosen for each examined
equipment. The behavior of the outlet temperatures of each gas stream as function of porosity is also
analyzed. The results show that the porosity ranges shorten when the typical pressured drop values
for each rotary exchanger are introduced in the analysis. In addition, the behavior of the outlet
temperatures is compatible with the behavior of the heat transfer rate as the porosity changes.