Numerical analysis of an urban road pavement solar collector (U-RPSC) for heat island mitigation: Impact on the urban environment

Abstract

The Urban Heat Island (UHI) effect is a phenomenon whereby urban areas become warmer than their surrounding rural areas, due to the replacement of vegetation and soil with built surfaces. The increase in urban temperatures can increase energy demand for cooling buildings, elevate emissions of air pollutants, compromise health (overheating) and cause thermal discomfort. Road Pavement Solar Collector (RPSC) system is one of the UHI mitigation strategies that absorbs heat from the road surface and converting the heat into passive thermal energy. This work aims to determine the impact of the RPSC system on the urban air temperature using the Computational Fluid Dynamics (CFD) ANSYS Fluent 19.2 program. The modelling method was initially validated with a laboratory-scale RPSC system. The model was set using the weather and surface temperature data of the hot and humid city of Kuala Lumpur. The influence of the RPSC system embedment; within urban street canyons and outside of the street canyons was investigated. The study also assessed the influence of changing the urban street canyon configuration based on the length and the height of the building rows on the RPSC performance. Based on the conditions modelled and simulation results, the best performance was obtained by embedding the RPSC system within the long and deep street canyon. The results presented here also showed the potential of the RPSC system in mitigating the UHI effect during hot and calm nocturnal period.