Paper Conference

Proceedings of eSim 2016: 9th Conference of IBPSA-Canada


Steady-state modelling of falling film drain water heat recovery efficiency using rated data

Ramin Manouchehri, Michael Collins

Abstract: Drain water heat recovery (DWHR) systems recover heat from a building’s greywater and use it to preheat incoming mains water. The rated effectiveness of such systems is typically determined at a fixed temperature difference and flow rate, and under steady-state and equal flow conditions. Unfortunately, this may not be representative of what is actually occurring during operation. The present work attempts to bridge this gap by producing correlations that are capable of predicting steady-state performance based on data produced during the rating process. DWHR system performance turns out to be highly predictable, regardless of system size or coil design. Starting with rated data, one can reliably find the performance as a function of flow rate, adjust the results for different inlet water temperatures, and then account for non-equal flow conditions. Experiments show that the complete model is able to predict heat transfer rates to within about 2.5%.
Pages: 638 - 647