Search

For the growth of sustainable energy, increasing the efficiency of photovoltaic/thermal (PV/T) systems is still essential. Particularly ternary hybrid nanofluids have shown promise as a means of improving the systems' electrical and thermal performance. This study delves deeply into the exploration of a three-dimensional annulus-type Photovoltaic Thermal (PV/T) system, centering on its cooling function through the utilization of ternary hybrid nanofluids featuring diverse nanomaterial shapes. The system structure involves a circular cylinder enveloped within glass, silicon, and copper layers, forming the core of the PV panel. The investigation employs COMSOL Multiphysics 6.0 with boundary conditions like radiative heat flux on the upper domain. Nanofluids with varied shapes (spherical, brick-like, cylindrical, platelet, and blade-shaped) comprising copper, aluminum oxide, and micro-wall carbon Nanotubes suspended in water are scrutinized as the base fluid. Using COMSOL Multiphysics, our simulation employs a conjugate heat transfer interface to solve the intricate three-dimensional Navier-Stokes equations and energy equations, addressing the combined convection challenges in the system. Analyzing parameters such as Reynolds number (100–1500), aspect ratios (0.1, 0.15, 0.2), shape factors (3–8.9), and total volume fractions of nanomaterials (1%–10 %), we noted a significant decline (21–28 %) in the average Nusselt number as nanoparticle concentration increased. This trend highlights strengthened convection processes, notably observable with increased flow pipe diameter or aspect ratio. This decrease suggests that the system's convective heat transfer efficiency has decreased. Nonetheless, because the PV cells are better cooled, the decrease in convective heat transfer is accompanied by an increase in the electrical efficiency of the system. The practical implication of this trend is that even though the thermal performance in terms of heat removal may decline, the overall cooling effect still helps to keep the PV cells' temperature down, thereby raising their electrical output. The study revealed enhanced electrical efficiency (up to 9.3834 %) with blade-shaped particles under specific conditions: Re = 1500, 10 % volume fraction, and an aspect ratio of 0.1. Additionally, the investigation suggests a potential for achieving a maximum thermal efficiency of 85.62 %. These findings underline the promising impact of nanomaterial manipulation on both electrical and thermal efficiencies within the PV/T system while the maximum temperature at the outlet reaced to 5.470 C.

The performance of air-type PVT and BIPVT collectors has been extensively studied. As a system that generates heat and power, PVT collector testing has some particularities especially when using air as a heat recovery fluid and a building-integrated design (BIPVT). The electrical and thermal experimental performance of such collectors are currently being evaluated using in-house methods or PV and/or solar thermal collector standards. The use of a wide range of methods, testing conditions and experimental setups makes it difficult not only to compare the performance of different designs, but also to have confidence in the results obtained. This study evaluates the performance of an air-type BIPVT collector with in-channel perforated baffle plates for heat transfer enhancement designed for a building-integrated façade. As part of a joint research project between Korea and Canada, the proposed collector's performance was evaluated through indoor (Canada) and outdoor experiments (Korea). Limited comparison of the results obtained with the two testing methods could be performed due to differences in environmental testing conditions, BIPVT collector area and experimental setup. Nevertheless, the limited measurement points under comparable testing conditions indicate that the results from the indoor and outdoor experiments have a similar trend. A comparison between the studied collector having a full PV absorber and a BIPVT collector with a hybrid PV/solar thermal collector absorber using a similar indoor experimental setup and testing conditions was performed. It showed that under still air conditions, for an irradiance level of approximately 820 W/m2 and with a low flow rate, the BIPVT collector with a hybrid PV/solar thermal absorber has a thermal and electrical efficiency of 25.1% and 5.9%, respectively. Under similar conditions, the BIPVT collector with a full PV absorber has a thermal efficiency of 23.9% and an electrical efficiency of 13.5%. At higher flowrates, both units have similar thermal efficiencies, however, the BIPVT collector with a PV absorber remains with an electrical efficiency that is more than double that of the unit with a hybrid PV/solar thermal absorber. [ABSTRACT FROM AUTHOR]

PV power generation is a viable option to resist fossil fuels, which consume and harm the environment, but increasing the cell temperature of the photovoltaic device reduces its electrical performance. The photovoltaic thermal PVT system is a suitable technology to improve electrical performance and obtain useful heat, which improves the overall efficiency. To overcome the challenges, a new dual oscillating absorber copper pipeline flow that was designed based on the PVT water system, was developed and studied. ANSYS 19.2 was used to predict the outlet water temperature and surface temperature of PVT model based numerical simulations, were irradiation levels of 600, 800, and 1000 W/m2 with the mass flow rate at 2, 4, and 5 LPM and water temperature inlet 26°C. The experiment was conducted outdoors under Malaysian weather conditions at different value flow rates of 2–6 LPM for the present investigation. The CFD results were validated with the experimental results. Validation ensures good agreement between the numerical and experimental results. The results show that the maximum average thermal efficiency of photovoltaic thermal (PVT) system is 59.6%. The highest average value of electrical efficiency of PV panel and the PVT water system was found to be 10.86% and 11.71%, respectively at a mass flow rate 6 LPM. The PVT electrical, thermal efficiency and the output power increased with the increase in mass flow. The thermal efficiency increased with the increase in the mass flow rate, solar irradiation level and reducing the difference between water inlet and outlet temperature. While, the cell temperature decrease with the increase in the mass flow rate. The maximum electrical performance achieved using the PVT system 11.71%.

The performance of air-type PVT and BIPVT collectors has been extensively studied. As a system that generates heat and power, PVT collector testing has some particularities especially when using air as a heat recovery fluid and a building-integrated design (BIPVT). The electrical and thermal experimental performance of such collectors are currently being evaluated using in-house methods or PV and/or solar thermal collector standards. The use of a wide range of methods, testing conditions and experimental setups makes it difficult not only to compare the performance of different designs, but also to have confidence in the results obtained. This study evaluates the performance of an air-type BIPVT collector with in-channel perforated baffle plates for heat transfer enhancement designed for a building-integrated façade. As part of a joint research project between Korea and Canada, the proposed collector’s performance was evaluated through indoor (Canada) and outdoor experiments (Korea). Limited comparison of the results obtained with the two testing methods could be performed due to differences in environmental testing conditions, BIPVT collector area and experimental setup. Nevertheless, the limited measurement points under comparable testing conditions indicate that the results from the indoor and outdoor experiments have a similar trend. A comparison between the studied collector having a full PV absorber and a BIPVT collector with a hybrid PV/solar thermal collector absorber using a similar indoor experimental setup and testing conditions was performed. It showed that under still air conditions, for an irradiance level of approximately 820 W/m2 and with a low flow rate, the BIPVT collector with a hybrid PV/solar thermal absorber has a thermal and electrical efficiency of 25.1% and 5.9%, respectively. Under similar conditions, the BIPVT collector with a full PV absorber has a thermal efficiency of 23.9% and an electrical efficiency of 13.5%. At higher flowrates, both units have similar thermal efficiencies, however, the BIPVT collector with a PV absorber remains with an electrical efficiency that is more than double that of the unit with a hybrid PV/solar thermal absorber.

This paper presents a comparative study between compound parabolic concentrated (CPC) and conventional flat hybrid double-pass photovoltaic–thermal (PVT) systems. A mathematical thermal–electrical model is developed and verified with published experimental data. The use of detailed five-parameter electrical modeling in the analysis made it possible to estimate the electrical parameters of PV cells, such as voltage and current. A parametric study is conducted to investigate the effect of different design and operation variables such as length, packing factor, duct depth and flow rate on thermal and electrical performance. Furthermore, the study investigated the performance of proposed systems with fins attachment and the effect of their material and type on performance. The model is applied to simulate and analyze thermal and electrical performance of finned (F) and un-finned (UF) flat and CPC photovoltaic systems for a selected case at Dhahran, Saudi Arabia. The results show that annual thermal gain is 1% higher for flat-PVT (F) compared to flat-PVT (UF). On the other hand, the annual electrical gain for flat-PVT (F) is 3% higher than flat-PVT (UF). The CPC-PVT (F) is estimated to have more than 3% thermal and 8% electrical gain compared to CPC-PVT (UF). Among studied four configurations, CPC-PVT (F) system will have the best performance. [ABSTRACT FROM AUTHOR]

Abstract: Façade-integrated photovoltaic/thermal (BiPV/T) technology is a relatively new concept in improving the overall energy performance of PV installations in buildings. With the use of wall-mounted water-type PV/T collectors, the system not only generates electricity and hot water simultaneously, but also improves the thermal insulation of the building envelope. A numerical model of this hybrid system was developed by modifying the Hottel–Whillier model, which was originally for the thermal analysis of flat-plate solar thermal collectors. Computer simulation was performed to analyze the system performance. The combined effects of the solar cell packing factor and the water mass flow rate on the thermal and electrical efficiencies were investigated. The simulation results indicated that an optimum water mass flow rate existed in the system through which the desirable integrated energy performance can be achieved. [Copyright &y& Elsevier]