All the previous theoretical models of the dynamic thermal behavior of the periodic–flow Air Pre-Heater (APH) have ignored the effects of the baskets walls. Therefore, the purpose of this work is to develop experimental and a numerical model simulating transient energy transport in a periodic-flow regenerative APH to involve the important thermal effect of the basket walls surrounding the heating element matrices.
Three main different types of matrices that are intended to be used in periodic-flow APH have been investigated and comparison was made between them. These materials are corrugated plates matrices (CPMs), wire mesh matrices (WMMs) and stone media matrices (SMMs). Total of (13) different configurations of matrices have been tested. The investigations covered a range of geometrical parameters of corrugated plate angle, wire diameter of mesh, pitch and screen to screen position and size of stones. The investigation has been carried out for hydraulic – diameter base Reynolds number, Re, in the range of 680<Re < 10100.
The basket wall was determined to have a significant influence on the thermal behavior of the packing matrices especially in the near–wall region, and had been seen to introduce different thermal response for each type of the tested materials.
New (13) correlation equations for the overall J-factor have been developed for each matrix type to provide the best matching between the gathered experimental data with the numerical model.