The purpose of this paper is to study the energy efficiency of a local living space exposed to solar radiation in the subtropical climate of Casablanca. The study was mainly focused on the contribution of a phase chan...The purpose of this paper is to study the energy efficiency of a local living space exposed to solar radiation in the subtropical climate of Casablanca. The study was mainly focused on the contribution of a phase change material (PCM), inserted into a 7-cm thick air layer of a double brick wall, in two different locations. We note that the experimental study was conducted using two real-scale test cavities, located in the Faculty of Science Ain Chock-Casablanca. Two PCM mounting methods were used for the south and west walls, in order to test its energy efficiency as a storage and retrieval means of the solar flux coming from the outside. In the case of the southern wall, the PCM is put directly on the internal side of the outside part of the double wall (Case 1). For the west wall, the PCM is placed 1.2 cm away from the internal side of the outer part of the double wall (Case 2). The first result shows that the PCM placed to the wall allows storing the solar heat during the day and releasing it to the outside of the building at night. While in the second case, the PCM keeps the heat stored day and night.展开更多
Cotton fabrics treated with phase change materials( PCMs)were used in multi-layered fabrics of the fire fighter protective clothing to study its effect on thermal protection. The thermal protective performance( TPP) o...Cotton fabrics treated with phase change materials( PCMs)were used in multi-layered fabrics of the fire fighter protective clothing to study its effect on thermal protection. The thermal protective performance( TPP) of the multi-layered fabrics was measured by a TPP tester under flash fire. Results showed that the utilization of the PCM fabrics improved the thermal protective performance of the multi-layered fabrics. The fabric with a PCM add on of 41. 9% increased the thermal protection by 50. 6% and reduced the time to reach a second degree burn by 8. 4 s compared with the reference fabrics( without PCMs). The employment of the PCM fabrics also reduced the blackened areas on the inner layers. The PCM fabrics with higher PCM melting temperature could bring higher thermal protective performance.展开更多
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
文摘The purpose of this paper is to study the energy efficiency of a local living space exposed to solar radiation in the subtropical climate of Casablanca. The study was mainly focused on the contribution of a phase change material (PCM), inserted into a 7-cm thick air layer of a double brick wall, in two different locations. We note that the experimental study was conducted using two real-scale test cavities, located in the Faculty of Science Ain Chock-Casablanca. Two PCM mounting methods were used for the south and west walls, in order to test its energy efficiency as a storage and retrieval means of the solar flux coming from the outside. In the case of the southern wall, the PCM is put directly on the internal side of the outside part of the double wall (Case 1). For the west wall, the PCM is placed 1.2 cm away from the internal side of the outer part of the double wall (Case 2). The first result shows that the PCM placed to the wall allows storing the solar heat during the day and releasing it to the outside of the building at night. While in the second case, the PCM keeps the heat stored day and night.
基金Fundamental Research Funds for the Central Universities,China(No.14D110715/17/18)Start up Fund by Shanghai University of Engineering Science(No.2015-69)Young Teacher Training Program by Shanghai,China(No.ZZGCD15051))
文摘Cotton fabrics treated with phase change materials( PCMs)were used in multi-layered fabrics of the fire fighter protective clothing to study its effect on thermal protection. The thermal protective performance( TPP) of the multi-layered fabrics was measured by a TPP tester under flash fire. Results showed that the utilization of the PCM fabrics improved the thermal protective performance of the multi-layered fabrics. The fabric with a PCM add on of 41. 9% increased the thermal protection by 50. 6% and reduced the time to reach a second degree burn by 8. 4 s compared with the reference fabrics( without PCMs). The employment of the PCM fabrics also reduced the blackened areas on the inner layers. The PCM fabrics with higher PCM melting temperature could bring higher thermal protective performance.
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.
