Preliminary study of a dual channel solar photocatalytic ventilation wall system for year-round air purification and building energy savings

Abstract

With the aim of meeting the weak adaptability to different seasons and low solar energy utilization efficiency for solar ventilation wall system. In the present work, a novel dual-channel solar photocatalytic ventilation wall (DSPVW) integrated with a photovoltaic (PV) panel and phase change materials (PCM) has been numerically proposed and simulated in winter and summer in subtropical climate zone. A range of performance indicators, such as outlet temperature, air heating gain, and clean air delivery rate (CADR), is evaluated. Furthermore, a comparative analysis is performed to assess the energy and exergy characteristics, distribution, comfortable temperature range percentage (CTRP), energy consumption and savings rate of three different systems: typical solar photocatalytic ventilation wall (SPVW), dual-channel solar photocatalytic ventilation wall (DSPVW), and DSPVW-PV/PCM. Results show that melting temperature of 313.15 K and 323.15 K respectively shows a good performance in winter and summer. The rate of temperature change and peak temperature to the outlet air slow down and decrease with the increase of PCM thickness, resulting in a cooling effect of 1.27 % and 2.83 % in winter and summer. In addition, the simulations with small channels exhibit poor thermal performance but better air purification effect, reaching total CADR as high as 69.46 m3 and 67.33 m3 respectively in winter and summer. Meanwhile, the energy consumption and energy saving rate of the DSPVW-PV/PCM is −3.09 kW and 75.7 %, respectively, compared to the SPVW system. This study could contribute to the widespread adoption and application of solar ventilation walls in regions with hot summers and warm winters.