Thermal Efficiency and Heat Removal Factor for Hybrid Photovoltaic Thermal PVT System (original) (raw)
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Much effort has been spent on the development of hybrid PVT, in order to improve the thermal and cell efficiency. It is known fact that the efficiency of the photovoltaic panel decreases when the ambient temperature increased. The photovoltaic panel absorbed sunlight from the sun and convert it to electricity. In this study, the solution for this was by adding a cooling system to thephotovoltaic panel. The purpose of this study was to cool the solar cell in order to increase its electricalefficiency and also to produce heat energy in the form of hot water. The rectangular tube absorber was located at the back side of a standard photovoltaic panel. The simulation results shows that the Rectangular tube absorber collector generates combined PV/T efficiency of 65.8% with electrical efficiency of 11.4% at ambient temperature set between 28.6 to 33.55°C, fluid flow rate at 0.045kg/s and solar radiation between 700 to 800 W/m 2 . It is recommended for PV/T system to further improve its efficiency by optimizing the contact surfaces between the solar panel (photovoltaic module) and the absorber collector underneath.
Performance of Photovoltaic Thermal Collector (PVT) With Different Absorbers Design
Much effort has been spent on the development of hybrid PVT, in order to improve it efficiency of both, thermal and cell. The combination of thermal and cell efficiencies, which is commonly known as "total efficiency of the PVT", is influenced by many system design parameters and operating conditions. Due to that, seven new design configurations of absorber collectors are designed, investigated and compared. Simulations were performed to determine the best absorber design that gives the highest efficiency (total efficiency). In these simulations, the system is analyzed with various parameters, such as solar radiation, ambient temperature, and flow rate conditions. It is assumed that the collector is represented as a flat plate thermal collector with single glazing sheet. Based on these simulations, spiral flow design proved to be the best design with the highest thermal efficiency of 50.12% and corresponding cell efficiency of 11.98%.
Numerical Performance Investigation of Hybrid PV/Thermal System
International Journal of Engineering & Technology
Promoting reduction of PV temperature plays crucial role in increasing electrical performance. The present work deal with different types of absorber shape for analysing heat transfer phenomena. Serpentine and spiral absorber are using to verify this purpose with different boundary conditions of inlet mass flow rate and inlet temperatures.The recent study was conducted to evaluate the effect of some operating and designing parameters such as solar radiation levels, flow rates, absorber shape and cooling water temperature on the performance of PVT system numerically. Performance of PVT system determined by thermal efficiency, electrical efficiency and the summation of both known as total or PVT efficiency. Solar radiation ranging from 500 W/m2 to1000 W/m2 was introduced and at each, flow rates of water ranging from 0.016 kg/s to 0.05 kg/s. The results show that the performance of PVT increases with a flow rate at all radiation levels. Also the spiral flow absorber gives a higher perf...
Comparative Study Of Two New Configurations Of Solar Photovoltaic Thermal Collectors
2013
Hybrid photovoltaic thermal (PV/T) solar system comprises a solar collector which is disposed on photovoltaic solar cells. The disadvantage of a conventional photovoltaic cell is that its performance decreases as the temperature increases. Indeed, part of the solar radiation is converted into electricity and is dissipated as heat, increasing the temperature of the photovoltaic cell with respect to the ambient temperature. The objective of this work is to study experimentally and implement a hybrid prototype to evaluate electrical and thermal performance. In this paper, an experimental study of two new configurations of hybrid collectors is exposed. The results are given and interpreted. The two configurations of absorber studied are a new combination with tubes and galvanized tank, the other is a tubes and sheet.
The feasibility of new design of hybrid photovoltaic-thermal system – a theoretical approach
International journal of ambient energy, 2017
The feasibility of new design of hybrid photovoltaic-thermal system-A theoretical approach The evaluation of hybrid photovoltaic thermal (PVT) collectors has been implemented according to the physical features of commercial photovoltaic cells; therefore, their commercial application is limited. For the Tedlar, it has good electrical insulating properties resulting in a reduction of the electrical efficiency. A researcher found that the glazed PVT system without Tedlar was the best system among others with a significant increase in the overall efficiency. From this finding, we thought the first study on the feasibility of a new design of PVT collector performed by modifying a commercial PV panel and retrofitting it with the integration of two tubes in glass above the photovoltaic cell pasted on thin metal ribbon before PV encapsulation. A heat transfer modelling/simulation in 3D were performed using a COMSOL MULTIPHYSICS. The results show that under the situation where no cooling was used, the temperature of PV cell attained a value as high as 74.87°C and the electrical power dropped significantly to 0.113% for the electrical efficiency of the reference conditions equals to 0.15. The water flow velocity is determined so that the cell can be effectively cooled. a variation of temperature that reaches to 45.9°C to a speed value equal to 0.5m/s for an irradiation of 1000W/m² and ambient temperature equal to 20.15°C.
Thermal Modeling of Photovoltaic Thermal System with Polymer Sheet in Tube Absorber Collector
Applied Mechanics and Materials, 2014
This study developed a thermal model of a photovoltaic thermal collector (PVT) to predict the performance and outlet temperature of the system. The PVT consisted of a polycrystalline photovoltaic module, a polymer collector–type sheet in a tube, and an insulator. The motivation of the present work is that the polymer materials are flexible, low cost and lightweight which are for the PVT applications. The outlet temperature of the PVT increased with the decreasing rate of mass flow into the riser because the water had sufficient time for thermal heating. One unit of polymer collector can achieve an outlet temperature of 69 °C at 500 W/m2 at a mass flow rate of 0.0063 kg/s.
2019
PVT solar systems are recently emerging solar technology that allows the simultaneous conversion of solar energy into both electricity and heat. The aim of these systems PVT is to improve the electrical efficiency with the cooling system by reducing the temperature of the cell. The performance of PV is reduced with the increase in temperature and use under the advice the absorber collector takes in the excess heat underneath the PV and transfers the heat through the working fluid such as water. The harvested heat is used for low-temperature applications such as domestic hot water supply, water preheating, and space heating. In this paper, the effects of the major control parameters on the thermal and electrical performance of PVT collectors are compiled and reviewed. Figures and tables are provided to give an overall picture of how PVT performance could be improved in terms of these parameters. Although investigators understand the effects of different parameters, the improvement of PVT performance by optimizing these parameters has not been fully realized.
Solar Energy, 2023
This study proposes a numerical model to investigate the effectiveness of using half-circular tubes to improve thermal conductivity and increase the interaction area between PV panels and tubes. This enhances heat transfer from the PV panels to the working fluid (water) circulating through the thermal absorber. Additionally, the integration of phase change material (PCM) is explored to further boost thermal conductivity and generate hot water. The research focuses on modeling the cooling of solar PV panels using copper half-tubes. The PV panels measure 870 × 665 × 3 mm and generate a power output of 100 W. The study examines the impact of key variables such as tube diameter (three standard sizes: 10, 12, and 15 mm) and fluid flow rate (0.008 to 0.04 kg/s). Solar radiation equations are incorporated, and the finite volume approach, implemented in the ANSYS 19.0 software's CFX modeling framework, is used as the underlying methodology. The investigation culminates in an optimization process to determine the optimal operating conditions for the PV system. The results show that the highest electrical efficiency (13.15%) is achieved at a flow rate of 0.04 kg/s for 15 mm diameter tubes and 7 tubes in total. The peak thermal efficiency (74.28%) is observed under the same conditions. In conclusion, this study contributes to the understanding of enhancing PV/T system performance through innovative thermal management strategies and provides valuable optimization recommendations for achieving improved electrical and thermal efficiencies.
A review on hybrid photovoltaic/thermal collectors and systems
In this paper, a thorough review of the available literature on photovoltaic/thermal (PV/T) systems is presented. The review is performed in a thematic way in order to allow an easier comparison, discussion and evaluation of the findings obtained by researchers, especially on parameters affecting the electrical and thermal performance of PV/T systems. The review covers a comprehensive historic overview of PV/T technology, detailed description of conventional flat-plate and concentrating PV/T systems, analysis of PV/T systems using water or air as the working fluid, analytical and numerical models, simulation and experimental studies, thermodynamic assessment of PV and PV/T systems and qualitative evaluation of thermal and electrical outputs. Furthermore, parameters affecting the performance of PV/T systems such as glazed versus unglazed PV/T collectors, optimum mass flow rate, packing factor, configuration design types and absorber plate parameters including tube spacing, tube diameter and fin thickness are extensively analyzed. Based on the thorough review, it can be easily said that the PV/T systems are very promising devices and PV/T technology is expected to become strongly competitive with the conventional power generation in the near future.