PV-Trombe Wall Research Articles

Review on the progress of building-applied/integrated photovoltaic system.

Integration of photovoltaic (PV) technologies with building envelopes started in the early 1990 to meet the building energy demand and shave the peak electrical load. The PV technologies can be either attached or integrated with the envelopes termed as building-attached (BA)/building-integrated (BI) PV system. The BAPV/BIPV system applications are categorized under the building envelope roof and facades as PV-roof, PV-skin facade, PV-Trombe wall, PV claddings, and louvers. This review covers various factors that affect the design and performance of the BAPV/BIPV system applications. The factors identified are air gap, ventilation rate, a tilt angle of PV shading devices, adjacent shading, semitransparent PV (STPV) glazing design, cell coverage ratio (CCR), transmittance, window to wall ratio (WWR), and glazing orientation. Furthermore, the results of the possible factors are compared to building locations. This review article will be beneficial for researchers in designing the BAPV/BIPV system and provides future research possibilities.

The performance analysis on a novel purified pv-trombe wall for electricity, space heating, formaldehyde degradation and bacteria in activation

On the one hand, PV-Trombe wall is a combined solar system that meets dual functions of space heating and electricity output, but the utilization on the recovered solar heat by PV-Trombe wall is very limited. On the other hand, thermal catalytic oxidation and thermal sterilization are two advanced air purification technologies and both they have huge application potential with solar heat. Therefore, a novel purified PV-Trombe wall for electricity, space heating, formaldehyde degradation and bacteria inactivation was proposed. Firstly, the system thermal and mass transfer model was established and verified by experimental data. Secondly, the comprehensive performance with the PV coverage ratio of 0 was analyzed. Finally, the effect of PV coverage ratio on the system performance was investigated. Accordingly, the main results were: ① Under PV coverage ratio of 0, the average daily air thermal efficiency and formaldehyde single-pass ratio were 0. 46 and 0. 35, respectively. Meanwhile, the total generated volume of clean air by formaldehyde degradation was 93. 4 m3 . Five kinds of bacteria were fully thermal inactivated for several hours. Accordingly, the total generated volume of clean air were 188. 3, 173. 0, 201. 4, 189. 9 and 200. 2 m3 for E. coli, L. monocytogenes, L. plantarum, S. Senftenberg and S. cerevisiae, respectively. ② The PV coverage ratio played a different role on the system comprehensive performances. For specific performances, the PV coverage ratio only had a positive influence on electrical performance and had negative effect on other performances such as thermal, formaldehyde degradation and bacteria inactivation performances. However, considering the system comprehensive performances, the electrical energy was the additional product and the low PV coverage ratio was suggested. ③ The works could provide possible support to the prevention and control of COVID-19. © 2021, Editorial Department of Journal of University of Science and Technology of China. All rights reserved.

Numerical and experimental study on the performance of a Photovoltaic Trombe wall system with Venetian blinds

The integration of a photovoltaic system with the Trombe wall system (PVTW) is effective in thermal load regulation of buildings and electrical energy production. The modification of the PVTW system by adding a Venetian blind can regulate the airflow and provide shading. In this study, the experimental and numerical simulation results for the novel Photovoltaic Trombe wall system with a Venetian blind (PVTW_Ven) and the conventional Trombe wall system with a Venetian blind (TW_Ven) are compared. The experiments were conducted in a test room equipped with the PVTW_Ven and TW_Ven systems located in Abha, Asir Province of Saudi Arabia, with semiarid climatic conditions. The results obtained by numerical simulation were validated by comparing with experimental results. The results indicate that the average heat gain of the TW_Ven configuration is 1.33 times more than that of the PVTW_Ven configuration, with a 5.2 °C higher outer wall surface temperature. The temperature can be systematically regulated inside the test room by installing a Venetian blind with the slats at optimal 60° in the air gap of both configurations. The maximum temperature of the Venetian blind in the PVTW_Ven configuration is 4.7 °C lower than that in TW_Ven.

Numerical Study of Mixed Convection in a Photovoltaic Trombe Wall Channel Coupled with a Solar Chimney Integrated into a Building for Habitats Passive Cooling

The solar chimney can generate airflow through the living space of the building to provide cooling. Hence, solar energy represents the best renewable, environmentally friendly source of energy that can be used for heating and cooling of houses. The present paper reports the numerical study of the performance of the mixed convection in the associated hybrid Photovoltaic/Thermal chimneys integrated into building for natural habitat ventilation. The front side glass plate of the chimneys is heated by a non-uniform daily solar radiation flux. Air is considered to be the cooling fluid. The stream fucntion-vorticity formulation with a finite difference numerical discretization solution scheme has been adopted. The system of algebraic governing equations is solved by Thomas algorithm method. The aim of the present paper is to study and to predict the dynamic fields and particularly of the mass flow rate of the air thermosiphon drawing in the associated hybrid Photovoltaic-Thermal chimneys integrated into a building for passive cooling in the habitats. The effects of the governing parameters, namely Reynolds number (30 ≤ Re ≤ 200), Rayleigh number (103 ≤ Ra≤ 105), the integrated chimney width on the fluid flow and the heat transfer characteristics, are studied in detail. The local Nusselt number, streamlines, isotherms, PV cells electrical efficiency and the outlet velocity at the top of the channels are the results represented versus the above controlling parameters.

Performance study of a novel multi-functional Trombe wall with air purification, photovoltaic, heating and ventilation

A novel multi-functional passive solar wall, i.e., photocatalytic-photovoltaic-Trombe wall (PC-PV-Trombe wall), which can obtain heat, electricity and fresh air simultaneously was proposed firstly. Then a multi-physical fields (velocity, temperature and concentration fields) coupling model was established to study the performance of PC-PV-Trombe wall. The effects of channel height and width on the thermal, electrical and degradation performance of PC-PV-Trombe wall were analyzed. Finally, the performance of PC-PV-Trombe wall, built-in PV-Trombe wall and PC-Trombe wall were compared under different solar radiation intensities and ambient temperatures. The results show that the ventilation volume, thermal efficiency, heat output, electrical efficiency and the clean air delivery rate of PC-PV-Trombe wall present different trends of increase or decrease with the change of channel height and width. As opposed to the effect on the electrical efficiency, the lower ambient temperature has a negative influence on the ventilation volume, thermal performance and air purification performance, especially for the condition of lower solar radiation intensity. PC-PV-Trombe wall can realize the comprehensive utilization for air purification, photovoltaic, heating and ventilation of solar energy and the total efficiency can reach a maximum of 0.67.

Experimental Study of Thermal Effect of Lacquer Coating for PV-Trombe Wall System Combined with Phase Change Material in Summer

This paper proposes a novel PV-Trombe wall system combined with phase-change material, which is named as PV-PCM-Trombe system. The work mainly experimentally studies the effectiveness and characteristics of using phase change materials to improve the overheating problem of PV-Trombe wall in summer. Through experiments, the photoelectric performance of the system using phase-change board surfaces with and without a matte black paint lacquer are compared; moreover, the influence on thermal environment of building is evaluated. The results indicate the PV-PCM-Trombe wall system shows an effective cooling effect on PV cell in both experiments and that the surface lacquer coating treatment of PCM plates affects little the photoelectric performance of the system and can reduce the working temperature of PV cell.

Performance analysis of PV/Trombe with water and air heating system: an experimental and theoretical study

ABSTRACT This paper studies an improved design of a photovoltaic/Trombe wall (PV-TW) system. It was integrating a PV panel with a serpentine-shaped copper tube as the water heating component and a single pass air channel as the air heating component. In addition to the electricity generated this type of PV-TW system enables to supply both hot air and water, which is increasing the total efficiency per unit area compared to the classical Trombe wall. The use of both fluids (bi-fluid) also creates a more excellent range of thermal applications and offers options in which hot air and water can be utilized depending on the energy needs and demands. In this paper, the design concept of the bi-fluid PV-TW system is emphasized with 1D steady-state energy balance equations for the bi-fluid configuration are developed, validated and used to predict the performance of the bi-fluid PV-TW system for a range of mass flow rates of air and water. Incorporating the DC fan and bi-fluid cooling circuits offered favorable features of the system performance while combining the glass cover in front of the PV cell has a conflicting effect. The maximum thermal and electrical efficiencies for average daily evaluation were 79.89% and 10.69% under 300 liters/day for bi-fluid with DC fan glazed and unglazed PV-TW systems respectively. A well matching between theoretical and the experimental results were achieved, where the maximum discrepancy between them was less 4% for the solar cell temperature.

Experimental and numerical study on the performance of a built-middle PV Trombe wall system

A built-middle PV Trombe wall (MPVTW) with solar PV panel installed in the middle of the air channel is proposed, designed, and manufactured in the present study. Comparative tests with the traditional built-external PV Trombe wall (EPVTW) were conducted in Hefei (117°E, 32°N), China to evaluate the performance of the MPVTW system. The average electrical and thermal efficiencies of the MPVTW system were measured as approximately 12.0% and 38.2%, respectively. The average value of the total efficiency of the MPVTW system was 10.83% higher than that of the EPVTW system. In addition, the effects of different parameters (i.e. channel height, the PV cells coverage ratio, and the PV cells position) on the energy performance of the MPVTW system were investigated by using the validated simulation model. The results show that the variations of these parameters have significant effects on thermal performance, but have little effect on electricity efficiency. The present study also found that when the distance (between the glass cover and PV module) was in the range of 12 mm–30 mm, the optimum values of total efficiency, thermal efficiency and electricity efficiency were 57.3%, 38.3% and 12.0%, respectively.

Dynamic performance analysis of façade-integrated tri-functional photovoltaic/thermal solar collector

Research on building-integrated photovoltaic/thermal (BiPV/T) technology has been conducted for years because the system can provide electric power and thermal energy simultaneously. A façade-integrated tri-functional PV/T collector system is presented and studied in this paper. The collector can work in PV/water-heating mode or PV/air-heating mode. Besides, it can also work in the composite mode that air and water be heated simultaneously. So optimum work mode of the collecor can be chosen for different energy demands. The collector can be combined with the southern wall of building, then it operates as PV-Trombe wall for passive room heating and electricity generation in winter, and for domestic water heating and electricity generation in other seasons. For the different working modes, theoretical research is carried out and dynamic model of the collector and building are developed. Based on the models, the performance of collector and the thermal behavior of the room are investigated under different climates conditions.

Enhancement of the performance of Photovoltaic/Trombe wall system using the porous medium: Experimental and theoretical study

The hybrid Photovoltaic/Thermal systems are suffering from the low electrical performance as a result of elevated its temperature. Present work attempts to enhance the performance of a hybrid Photovoltaic/Trombe wall (PV/TW) system through employing a porous medium. In this article, the effect of porous medium, DC fan and glass cover on the performance of a PV/TW was accomplished by the design and implementation of an experimental system to achieve this target. The mathematical method to predict the performance of a PV/TW system was also offered based on a simplified concept of an energy balance. The results of the theoretical study agreed well with the practical results in terms of the estimated temperature of the solar cell.The results revealed that incorporating the porous medium and DC fan offered favorable features of the system performance, while the glass cover has a conflict effect. It was confirmed that using porous medium and DC fan reduces the temperature of PV cell and increases the room temperature. Whereas, the presence of the glass cover in front of the system leads to elevate the temperatures of the room and solar cell. The presence of porous medium with DC fan increases the values of thermal and electrical efficiencies about 13% and 4%, respectively. Furthermore, the combined effect of porous medium with DC fan and glass cover increases the values of thermal and electrical efficiencies about 20% and 0.5%, respectively. It is recommended to integrate the PV/TW system with DC fan and porous medium for further conversion of solar radiation and improve building comfort conditions.

An experimental study of a built-middle Photovoltaic Trombe wall system

This paper proposed a PV-integrated Trombe wall system (PVTW) with the photovoltaic panel installed in the middle of air channel, named as built-middle photovoltaic Trombe wall system (PVMTW). The system has multiple functions: such as photovoltaic power generation, passive space heating, heat preservation and heat insulation. A series of tests were carried out in winter between the comparable hot- boxes to investigate the thermal and electrical performance of the PVMTW system. The results showed that the average electrical efficiency and thermal efficiency were 0.12 and 0.40, respectively, under the natural convection mode. The total efficiency of the PVMTW system was calculated to be 0.587, which is 11.4 % higher than that of traditional PVTW system with the solar cells laminated on the glass cover.

Energy-efficiency gain by combination of PV modules and Trombe wall in the low-energy building design

Ubiquitous modernization of building energy and management systems brings tendencies for an effective integration of renewables in buildings. This article shows how solar energy can be in charge of energy savings within a building by integration of solar systems with Trombe wall. Numerical calculations of Trombe wall thermal resistance and its performances in comparison with a common wall are considered. Additionally, energy-efficiency gaining by a combination of PV modules and Trombe wall, using simulations by SAM (System Advisor Model) software is discussed. PV module parameters and their impact on its electricity production are observed and analyzed. The PV module parameters, analyzed in the paper are: the tilt angle α of PV modules, incident angle β of direct sunrays on PV modules, normal beam irradiation N and PV cells operating temperature. With bigger incident angle β of direct sunlight on PV modules, the normal beam irradiation is smaller, which brings less electricity production. The impact of PV module operating temperature can be neglected in comparison with the impact of tilt angle on PV module electricity production. The optimal tilt angle of PV modules for generating maximum annual electricity is around latitude angle. It varies with normal beam irradiation to achieve the maximum monthly electricity production.

Design, construction and performance testing of a PV blind-integrated Trombe wall module

A novel PV blind-integrated Trombe wall module (PVBTW) was first designed and constructed in the present study. A series of experiments were carried out to measure and analyze the impact of different inlet air flow rates and PV blind angles on electricity generation and heat gains of the PVBTW module. The results showed that the inlet air flow rate of 0.45m/s and the angle of 50° were considered to be preferable for the PVBTW module. In order to determine the behavior of the designed PVBTW module, comparative experiments between the PVBTW module and the existing two types of PV-Trombe wall modules, namely PV cells fixed on the exterior glazing (PVGTW) and PV cells attached to massive wall (PVMTW) were then conducted under the real conditions. Through comparative experiments, it was found that electricity generation of the PVGTW module was highest, and those of the PVMTW and PVBTW modules were similar, whereas regarding to the heat gains, the ascending order became PVGTW, PVMTW and PVBTW. Combining heat gains and electricity generation, the PVBTW module was superior by 14.5% compared to the PVGTW and by 14.1% compared to the PVMTW with respect to the total efficiency.

Numerical modelling of effect of channel width on heat transfer and ventilation in a built-in PV-Trombe wall

The heat transfer and air flow rate in a built-in PV-Trombe wall with vertical inlet were numerically simulated based on CFD method. Effect of channel width on heat transfer and air flow rate was discussed. As the channel width increased, the natural convective heat transfer was enhanced and the PV surface was better cooled by the air which improved the PV electricity efficiency slightly. The ventilation rate through the built-in PV-Trombe wall reached its maximum at an optimal ratio of the channel width to the channel height, (b/H)opt=1/5. Dimensionless expressions to calculate the averaged heat transfer coefficient, Nusselt number, and the air flow rate in term of a Reynolds number were correlated according to a modified Rayleigh number by multivariable regression analysis.

Thermal comfort analysis of building assisted with Photo Voltaic Trombe wall

Maintaining indoor climatic conditions of buildings compatible with the occupant comfort by consuming minimum energy, especially in a tropical climate becomes a challenging problem for researchers. This paper aims to investigate this problem by evaluating the effect of different kind of Photovoltaic Trombe wall system (PV-TW) on thermal comfort, energy consumption and CO 2 emission. A detailed simulation model of a single room building integrated with PV-TW was modelled using TRNSYS software. Results show that 14-35% PMV index and 26-38% PPD index reduces as system shifted from SPV-TW to DGPV-TW as compared to normal buildings. Thermal comfort indexes (PMV and PPD) lie in the recommended range of ASHARE for both DPV-TW and DGPV-TW except for the few months when RH%, solar radiation intensity and ambient temperature were high. Moreover PVTW system significantly reduces energy consumption and CO 2 emission of the building and also 2-4.8 °C of temperature differences between indoor and outdoor climate of building was examined.

Performance Evaluation of PV-trombe Wall for Sustainable Building Development

This paper presents, a detailed simulation model of a single room building integrated with PV Trombe wall (PV-TW). Performance is evaluated in terms of room temperature, cooling load and PV efficiency by varying the air flow velocity for three different PV-TW Glazing types (i.e. Single Glazing, Double glazing, Double glazing filled with gas (Argon)). Simulation was done on TRNSYS software having inputs parameter as climatic conditions, building construction details, thermal properties of materials, detail of PV-TW and orientation of the building were inserted. By varying the air flow velocity and comparing the results of all three types of glazing it was found that PV Double glazing filled with argon shows significant results in reduction of cooling load of building, mean air duct temperature. Reduction of mean air duct temperature results in lowering of PV cell temperature which enhances the efficiency of PV panel. Also maximum room temperature reduction was found while using a double glass filled with argon PV-TW, which further reduces thermal load of the building. Air flow velocity shows significant effect on the performance of PV-TW up to certain values after which its effect stagnates and no further improvement was shown in all three types of PV-TW.

Energy and Cost Analysis of Photo Voltaic Trombe Wall System in Tropical Climate

The present study examines the performance of a single zone building integrated with PV Trombe wall(PV-TW) in term of potential cost savings, energy consumption and emission reduction by varying PV Glazing types (i.e. PV Single Glazing, PV Double glazing, PV Double glazing filled with gas (Argon)). TRNSYS software is used for simulation in which inputs like climatic conditions, building construction details, thermal properties of materials, detail of PV-TW and orientation of the building were inserted. By comparing the results of all three types of glazing The annual cost saving due to application of single glass PV- TW was RM 485.35; Double glass PV-TW was RM 819.15 while Double glass filled with argon PV-TW was RM 1016.24.While CO2 emission reduction is maximum in double glass filled with argon PV-TW 2588kg/yr followed by double and single glass PV-TW as 1768 and 1277kg/yr respectively.The analysis suggests that the application of double glass filled with argon PV-TW in Malaysia climatic condition would be economically viable from the point of view of saving in cooling energy cost and CO2 Emission.

Performance Analysis of Photo Voltaic Trombe Wall for Tropical Climate

The present study examines the performance of a single zone building integrated with PV Trombe wall (PV-TW) in term of thermal load reduction and electrical energy production by varying PV Glazing types (i.e. Single Glazing, Double glazing, Double glazing filled with gas (Argon)). TRNSYS software is used for simulation in which inputs like climatic conditions, building construction details, thermal properties of materials, detail of PV-TW and orientation of building is inserted. By comparing the results of all three types of glazing it is found that PV Double glazing filled with argon shows significant reduction in mean air duct temperature, hence reduces the PV cell temperature and increases power production of PV panel. Also solar radiation captured by massive wall of PV-TW is reduced by using PV Double glazing filled with argon as compared to other types of glazing, which further reduces thermal load inside the building.

Numerical Simulation of Air Flow in BiPV-Trombe Wall

A novel built-in photovoltaic Trombe wall (BiPV-TW) was proposed in this paper and the air flow in a BiPV-Trombe wall was numerically simulated by CFD method. The effect of channel height on flow patterns and air velocity was analyzed. The mass flow rate of air was calculated and a dimensionless expression to calculate the air flow rate in term of a Reynolds number was correlated according to a modified Rayleigh number and the aspect ratio, H/b, which took into account both of the channel sizes and solar radiation based on a multivariable regression analysis.

Modeling of Natural Ventilation in Built-in Photovoltaic-Trombe Wall

The natural ventilation in a novel built-in photovoltaic-Trombe wall (BiPV-TW) was numerically simulated by CFD method. The effect of solar radiation and channel width on the airflow pattern and ventilation rate was analyzed. Results showed that the solar radiation and channel width influenced the ventilation rate remarkably. As the solar radiation increased, the ventilation rate increased. As the channel width increased from 0.1m to 0.4m, the ventilation rate monotonously increased. However, when the channel width exceeded 0.5m, the reverse flow was formed in the tope zone and the ventilation rate decreased. A maximum air volume flow rate was achieved when the channel width was approximately equal to 0.4m in a 3m tall model.