Numerical Analysis of a Solar Chimney

Abstract

Passive ventilation is among the widely used means of reducing power consumption in residential as well as commercial establishments because of its cost and energy effectiveness. One method of passive cooling that has been around for many years is the use of solar chimneys.  Solar chimney is essentially a thermosyphon utilizing the energy from the sun. The energy coming from the sun heats up the air occupying the chimney cavity to create stack effect that in turn provides natural ventilation. In this study, two-dimensional numerical analysis of a vertical solar chimney is performed to determine the effect of air gap on air flow rate at a given range of solar radiation intensity of 200W/m² to 400 W/m². RNG k-epsilon turbulence model used was validated by comparing the results to experimental data, and is found to have good agreement with experiment data for air gap of 0.4. Equivalent air changes per hour (ACH) is then computed for a 59.27 m³ container house to be 5.4 for the vertical solar chimney model, with a chimney gap of 0.4 m at solar radiation intensity of 400 W/m².

Keywords— Numerical Analysis, Solar Chimney, thermosyphon