An investigation of the design and performance of a multi-stage downdraught evaporative cooler

Sarjito (2012) An investigation of the design and performance of a multi-stage downdraught evaporative cooler. (PhD thesis), Kingston University, .

Abstract

The aims of the research work described in this thesis were to use computational fluid dynamics (CFD) to investigate the factors affecting the performance of a multi-stage downdraught evaporative cooling device for low-energy cooling of buildings developed from a novel prototype device described by Erell et al. (2008) and Pearlmutter et al. (2008); and to model and explore the performance of the device when integrated within a hypothetical, but representative, building in a hot dry climate. The research work was carried out with initial objectives of: understanding and modelling water spray evaporation using CFD methods; verifying the CFD model of water spray evaporation using published experimental data; modelling and examining the spray characteristics of the nozzles used in the work by Erell et al. and Pearlmutter et al.; creating a detail model of the prototype multi-stage downdraught evaporative cooling device described by Erell et al. and Pearlmutter et al.; carrying out a series of CFD simulations of the prototype device under wind-driven operation with and without water sprays and comparing the results obtained with available experimental data. Following completion of these initial studies, a detailed investigation of the factors affecting the performance of a multi-stage cooling device derived from the prototype device was carried out. This involved carrying out simulations: to select the most effective wind catcher geometry; to optimize the number and arrangement of water spray nozzles; and to select a range of geometrical parameters. Following completion of these additional studies a model of a two-floor hypothetical building with an integrated multi-stage downdraught evaporative cooling device of optimum geometry and a wind catcher was created, and simulations to investigate the performance under varying wind speeds and environmental conditions were carried out. All simulations were carried out using ANSYS CFX, versions 12.0, or 12.1 or 13.0. The results obtained indicated that comfortable conditions within the cooled space could be achieved over almost all of the range the wind speeds and environmental conditions studied. Some recommendations for future work are given.

Actions (Repository Editors)

Item Control Page Item Control Page