A novel bifacial photovoltaic wall combining thermochromic material and double layers PCM(BPVW-TC+PCM)is proposed to passively regulate building heat gain and photovoltaic(PV)power generation through the dynamic color...A novel bifacial photovoltaic wall combining thermochromic material and double layers PCM(BPVW-TC+PCM)is proposed to passively regulate building heat gain and photovoltaic(PV)power generation through the dynamic color change properties of thermochromic glass and the latent heat storage capacity of the phase change material(PCM).Physical and numerical models of the composite wall system were developed,followed by numerical simulations to analyze indoor air temperature,PV power generation,and annual energy consumption in both ordinary and composite wall rooms.Additionally,optimization studies were conducted to determine the ideal phase change layer temperature and arrangement.The results indicate that this novel wall system significantly reduces indoor air temperature fluctuations and enhances PV power generation by approximately 16%in both summer and winter compared to conventional mono facial PV walls.The system achieves its lowest energy consumption when the high-temperature phase change layer is maintained at 28°C and the low-temperature phase change layer at 18℃,with both layers positioned on the interior side,resulting in an energy saving rate of 22.6%.展开更多
The integration of phase change material(PCM)with building-integrated photovoltaic(BIPV)presents a compelling approach to enhance solar energy utilization and mitigate indoor thermal loads,contributing to energy-effic...The integration of phase change material(PCM)with building-integrated photovoltaic(BIPV)presents a compelling approach to enhance solar energy utilization and mitigate indoor thermal loads,contributing to energy-efficient and low-carbon building development.Traditional BIPV-PCM structures,however,struggle to balance PV efficiency and thermal insulation,particularly with varying PCM wall positions.To address this situation,this study introduces a novel double-PCM BIPV composite envelope(BIPV-dPCM).An experimentally validated dynamic heat transfer model was developed and used to perform a comparative simulation analysis with three reference systems to quantify the energy-saving potential of the BIPV-dPCM,focusing on PV output and wall insulation effectiveness metrics.Further dimensionless parametric analysis were carried out to investigate the systematic performance of the two PCMs at different relativities.In addition,the coupled working mechanism of the BIPV-dPCM system concerning the power generation performance and thermal insulation performance under transient variations is explored.It was found that the BIPV-dPCM showcases superior thermoelectric coupling performance compared to three alternative enclosures.Incorporating two PCMs significantly enhances electrical exergy efficiency by 11.66%and thermal exergy efficiency by 1.54%,surpassing other reference systems.The increase in PCM latent heat ratio has a limited effect on performance gain.Notably,as the PCM thickness ratio exceeds 1,the decline in P value decelerates,for every 0.5 increment in the g,the P value diminishes by merely 0.2%.The ideal h is identified between 1 and 1.5,with 1.5 being optimal for energy conservation objectives.Additionally,the self-sufficiency coefficient(SSC)of the BIPV-dPCM remains robust,sustaining a range of 55%to 65%over prolonged periods.This study offers novel perspectives and serves as a design reference for optimizing building energy systems and enhancing cooling efficiencies in subtropical climates.展开更多
基金supported by the grants from the Key Research and Development Program of Anhui Province(no.S202203f07020001)。
文摘A novel bifacial photovoltaic wall combining thermochromic material and double layers PCM(BPVW-TC+PCM)is proposed to passively regulate building heat gain and photovoltaic(PV)power generation through the dynamic color change properties of thermochromic glass and the latent heat storage capacity of the phase change material(PCM).Physical and numerical models of the composite wall system were developed,followed by numerical simulations to analyze indoor air temperature,PV power generation,and annual energy consumption in both ordinary and composite wall rooms.Additionally,optimization studies were conducted to determine the ideal phase change layer temperature and arrangement.The results indicate that this novel wall system significantly reduces indoor air temperature fluctuations and enhances PV power generation by approximately 16%in both summer and winter compared to conventional mono facial PV walls.The system achieves its lowest energy consumption when the high-temperature phase change layer is maintained at 28°C and the low-temperature phase change layer at 18℃,with both layers positioned on the interior side,resulting in an energy saving rate of 22.6%.
基金supported by the Guangdong Basic and Applied Basic Research Foundation(Grant No.2023A1515010681)Fundamental Research Funds for the Central Universities(Grant No.21622417)Special Projects in Key Fields of Guangdong Universities(2022ZDZX1005).
文摘The integration of phase change material(PCM)with building-integrated photovoltaic(BIPV)presents a compelling approach to enhance solar energy utilization and mitigate indoor thermal loads,contributing to energy-efficient and low-carbon building development.Traditional BIPV-PCM structures,however,struggle to balance PV efficiency and thermal insulation,particularly with varying PCM wall positions.To address this situation,this study introduces a novel double-PCM BIPV composite envelope(BIPV-dPCM).An experimentally validated dynamic heat transfer model was developed and used to perform a comparative simulation analysis with three reference systems to quantify the energy-saving potential of the BIPV-dPCM,focusing on PV output and wall insulation effectiveness metrics.Further dimensionless parametric analysis were carried out to investigate the systematic performance of the two PCMs at different relativities.In addition,the coupled working mechanism of the BIPV-dPCM system concerning the power generation performance and thermal insulation performance under transient variations is explored.It was found that the BIPV-dPCM showcases superior thermoelectric coupling performance compared to three alternative enclosures.Incorporating two PCMs significantly enhances electrical exergy efficiency by 11.66%and thermal exergy efficiency by 1.54%,surpassing other reference systems.The increase in PCM latent heat ratio has a limited effect on performance gain.Notably,as the PCM thickness ratio exceeds 1,the decline in P value decelerates,for every 0.5 increment in the g,the P value diminishes by merely 0.2%.The ideal h is identified between 1 and 1.5,with 1.5 being optimal for energy conservation objectives.Additionally,the self-sufficiency coefficient(SSC)of the BIPV-dPCM remains robust,sustaining a range of 55%to 65%over prolonged periods.This study offers novel perspectives and serves as a design reference for optimizing building energy systems and enhancing cooling efficiencies in subtropical climates.
