Enhanced cooling system with integrated multi-geothermal concept– numerical and experimental studies

Abstract

In order to reduce the energy bills and pollution of buildings due to the use of conventional cooling systems, the present paper presents a parametric analysis and a case study concerning a newly proposed Multi Geothermal Cooling System that uses the cold soil to precool or cool air of several residences simultaneously. For that purpose, a thermal modelling and a related in-house code are developed. The modelling allows to predict the temperature of the precooled (or cooled) air in function of the return air temperature (hot flow) and the mass flow rate. The effect of other governing parameters has been evaluated, like the depth in soil, the tubes length and diameter. Modelling results have been confronted to experimentation showing a worst case error of 1.9 °C in the precooled air temperature. The work doesn't stop here. The predicted air temperature has been used in a numerical study of a multi geothermal cooling system with air-conditioning systems and different scenarios were simulated. Energy savings and reduction in CO2 emission have been evaluated for different coefficients of performance. Results are promising and relevant recommendations were put on firm roots.