A Numerical Performance Analysis of Heat Recovery Ventilators with Staggered-Baffle Channels

Abstract

This thesis presents a 2D numerical analysis of a cross flow compact energy recovery ventilator (HRV) with staggered baffle channels, using finite difference iterative method. The model was developed by discretization of the momentum and continuity equation into convective-diffusive terms and applying the power law scheme. Solving the system of equations required the combination of the Gauss-Seidel iterative method and the tridiagonal-matrix direct method applied to a staggered velocity and pressure grid. The Semi-Implicit method for the pressure-linked equations algorithm (SIMPLE) was chosen for coding of the program. The simulation was carried out to determine the effects of baffle height h/Dh, baffle spacing S/Dh and Reynolds number on thermal and flow performance, therefore it was necessary to vary one of the parameters within a range while all others were kept constant. The results showed that the baffle height has the greatest effect on the overall performance. At greater baffle heights the pressure drop, the Nusselt number, and heat transfer effectiveness was increased. The baffle pitch has the least effect on the overall performance; with increasing baffle pitch the pressure drop decreased while the Nusselt number had a slight increase prior to stabilization. The change of Reynolds increased the pressure drop and Nusselt number but reduced the residence time in the channel, diminishing the heat transfer effectiveness.