Experimental and Numerical Study for a Horizontal Wastewater Heat Recovery System

This study aims to numerically and experimentally investigate the performance of a drain water heat recovery device. Consequently, a heat exchanger prototype was developed to integrate with classic rectangular shower trays of small dimensions. The proposed drain water heat recovery (DWHR) system was tested using a specially designed experimental stand. In addition, the experimental data were compared to numerical results based on Computational Fluid Dynamics (CFD) simulations. The values of effectiveness and Number of Transfer Units (NTU) achieved for the proposed DWHR system, based both on experimental and numerical data, are similar to those from the literature for analogous configurations of horizontal DWHR systems. Consequently, the heat exchanger prototype analyzed could represent a pertinent solution for heat recovery from drain shower water with minimum investment costs.