scholarly journals Efficiency Improvement of a Photovoltaic Thermal (PVT) System Using Nanofluids

Energies ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 3063 ◽  
Author(s):  
Joo Hee Lee ◽  
Seong Geon Hwang ◽  
Gwi Hyun Lee
Keyword(s):  
Flat Plate ◽  
Flow Rate ◽  
Thermal Efficiency ◽  
Measurement Errors ◽  
Efficiency Analysis ◽  
Working Fluid ◽  
Efficiency Improvement ◽  
Flow Rates ◽  
Electrical Efficiency ◽  
Water Based

Many studies and considerable international efforts have gone into reducing greenhouse gas emissions. This study was carried out to improve the efficiency of flat-plate photovoltaic thermal (PVT) systems, which use solar energy to produce heat and electricity simultaneously. An efficiency analysis was performed with various flow rates of water as the working fluid. The flow rate, which affects the performance of the PVT system, showed the highest efficiency at 3 L/min compared with 1, 2, and 4 L/min. Additionally, the effects of nanofluids (CuO/water, Al2O3/water) and water as working fluids on the efficiency of the PVT system were investigated. The results showed that the thermal and electrical efficiencies of the PVT system using CuO/water as a nanofluid were increased by 21.30% and 0.07% compared to the water-based system, respectively. However, the increase in electrical efficiency was not significant because this increase may be due to measurement errors. The PVT system using Al2O3/water as a nanofluid improved the thermal efficiency by 15.14%, but there was no difference in the electrical efficiency between water and Al2O3/water-based systems.

scholarly journals An Experimental Performance on Solar Photovoltaic Thermal Collector with Nanofluids for Sustainable Development

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Srinivasulu Gundala ◽  
M. Mahaboob Basha ◽  
V. Madhurima ◽  
N. Praveena ◽  
S. Venkatesh Kumar
Keyword(s):  
Sustainable Development ◽  
Thermal Performance ◽  
Thermal Efficiency ◽  
Graphene Nanoplatelets ◽  
Solar Photovoltaic ◽  
Peak Period ◽  
Flow Rates ◽  
Experimental Performance ◽  
Electrical Efficiency ◽  
Water Based

In this article, the photovoltaic thermal collector (PVT) have designed and fabricated using nanoparticle nanofluid. The cause of this is to check out the effect of using water and water-based totally graphene nanoplatelets at an awareness of 0.05 wt% on the performance of PVT structures. Outdoor assessments have been performed at quantity along with the float prices of 0.5 L/min and 1.0 L/min for the aforementioned nanofluids, respectively, using water as a reference fluid. The results that have been analyzed from an active angle confirmed and determined that, graphene water nanofluid achieved higher in phrases of photovoltaic active conversion, than water that might generate the first-class thermal performance sooner or later of the peak period of sun radiation and high mobile temperature. The inclusion of water in the PVT collector increases average daily electrical efficiency by 7.8%, and 8.5%at flow rates of 0.5 LPM and 1.0 LPM, respectively. Furthermore, using water in the PVT collector increases average daily thermal efficiency by 24.9%, and 26.3%at flow rates of 0.5 LPM and 1.0 LPM, respectively.

The Effect of Hematocrit on the Clearance of Small Molecules during Hemodialysis

1983 ◽  
Vol 6 (3) ◽  
pp. 127-130 ◽  
Author(s):  
C. Woffindin ◽  
N.A. Hoenich ◽  
D.N.S. Kerr
Keyword(s):  
Blood Flow ◽  
Regression Analysis ◽  
Small Molecules ◽  
Flat Plate ◽  
Flow Rate ◽  
Distribution Curve ◽  
Blood Flow Rate ◽  
Hollow Fibre ◽  
Urea Clearance ◽  
Flow Rates

Data collected during the evaluation of a series of hemodialysers were analysed to see the effect of hematocrit on the clearance of urea and creatinine. All evaluations were performed on patients with a range of hematocrits with a mean close to 20%. The urea clearance of those in the upper half of the distribution curve (mean hematocrit 29.4%) was not significantly different from that of patients in the lower half of the distribution curve (mean hematocrit 16.9%) whether the clearance was studied at high or low blood flow rates and with hollow fibre or flat plate disposable hemodialysers. Likewise, there was no correlation between hematocrit and urea clearance by regression analysis. In contrast, the clearance of creatinine was affected by hematocrit being greater at lower hematocrit values. This difference was independent of blood flow rate and dialyser type and was confirmed by regression analysis.

scholarly journals An experimental study of the thermal performance of the square and rhombic solar collectors

2018 ◽  
Vol 22 (1 Part B) ◽  
pp. 487-494 ◽  
Author(s):  
Aminreza Noghrehabadi ◽  
Ebrahim Hajidavaloo ◽  
Mojtaba Moravej ◽  
Ali Esmailinasab
Keyword(s):  
Experimental Study ◽  
Flat Plate ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Thermal Performance ◽  
Thermal Efficiency ◽  
Solar Collectors ◽  
Heating Systems ◽  
Solar Water Heating

Solar collectors are the key part of solar water heating systems. The most widely produced solar collectors are flat plate solar collectors. In the present study, two types of flat plate collectors, namely square and rhombic collectors are experi?mentally tested and compared and the thermal performance of both collectors is investigated. The results show both collectors have the same performance around noon (?61%), but the rhombic collector has better performance in the morning and afternoon. The values for rhombic and square collectors are approximately 56.2% and 53.5% in the morning and 56.1% and 54% in the afternoon, respectively. The effect of flow rate is also studied. The thermal efficiency of rhombic and square flat plate collectors increases in proportion to the flow rate. The results indicated the rhombic collector had better performance in comparison with the square collector with respect to the mass-flow rate.

Modeling and Simulation Assessment of Solar Photovoltaic/Thermal Hybrid Liquid System Using TRNSYS

2015 ◽  
Vol 813-814 ◽  
pp. 700-706 ◽  
Author(s):  
R. Geetha ◽  
M.M. Vijayalakshmi ◽  
E. Natarajan
Keyword(s):  
Modeling And Simulation ◽  
Hybrid System ◽  
Flow Rate ◽  
Thermal Efficiency ◽  
Water Flow Rate ◽  
Exergy Efficiency ◽  
Hot Water ◽  
Solar Photovoltaic ◽  
Solar Pv ◽  
Electrical Efficiency

The PV/T hybrid system is a combined system consisting of PV panel behind which heat exchanger with fins are embedded. The PV/T system consists of PV panels with a battery bank, inverter etc., and the thermal system consists of a hot water storage tank, pump and differential thermostats. In the present work, the modeling and simulation of a Solar Photovoltaic/Thermal (PV/T) hybrid system is carried out for 5 kWp using TRNSYS for electrical energy and thermal energy for domestic hot water applications. The prominent parameters used for determining the electrical efficiency, thermal efficiency, overall thermal efficiency, electrical thermal efficiency and exergy efficiency are the solar radiation, voltage, current, ambient temperature, mass flow rate of water, area of the PV module etc. The simulated results of the Solar PV/T hybrid system are analyzed for the optimum water flow rate of 25 kg/hr. The electrical efficiency, thermal efficiency, overall thermal efficiency, equivalent thermal efficiency, exergy efficiency are found to be 10%, 34%, 60%, 35% and 13% respectively. The average tank temperature is found to be 50°C.

Energy and Exergy Analysis of Marquise Shaped Channel Flat Plate Solar Collector Using Al2O3–Water Nanofluid and Water

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
Sahil Arora ◽  
Geleta Fekadu ◽  
Sudhakar Subudhi
Keyword(s):  
Flat Plate ◽  
Flow Rate ◽  
Volume Fraction ◽  
Pure Water ◽  
Maximum Energy ◽  
Working Fluid ◽  
Absorber Plate ◽  
Energy And Exergy ◽  
Aluminum Plates ◽  
Flat Plate Collector

The present study deals with the experimental performance of a Marquise shaped channel solar flat-plate collector using Al2O3/water nanofluid and base fluid (pure water). The experimental setup comprises a special type of solar flat plate collector, closed working fluid systems, and the measurement devices. The absorber plate is made of two aluminum plates sandwiched together with Marquise-shaped flow channels. The volume fraction of 0.1% of Al2O3/water nanofluid is used for this study. The various parameters used to investigate performance of the collector energy and exergy efficiency are collector inlet and outlet fluid temperatures, mass flow rate of the fluid, solar radiation, and ambient temperature. The flow rate of nanofluid and water varies from 1 to 5 lpm. The maximum energy efficiencies attained are 83.17% and 59.72%, whereas the maximum exergy efficiencies obtained are 18.73% and 12.29% for the 20 nm—Al2O3/water nanofluids and pure water, respectively, at the flow rate of 3 lpm. These higher efficiencies may be due to the use of nanofluids and the sophisticated design of the absorber plate with the Marquise shaped channel.

Performance Study of Flowing-Over PV/T System with Different Working Fluid

2014 ◽  
Vol 488-489 ◽  
pp. 1173-1176 ◽  
Author(s):  
Li Qing Tang ◽  
Qun Zhi Zhu
Keyword(s):  
Thermal Efficiency ◽  
Experimental System ◽  
Experimental Results ◽  
Working Fluid ◽  
Performance Study ◽  
Electrical Efficiency ◽  
Overall Efficiency ◽  
T System

This paper studied the performance of a flowing-over PV/T system with water and Al2O3 nanofluid as the working fluid. The experimental system was built in the outdoors. The parameters of the experiment obtained for processing, analysis, accessing to the electrical efficiency and thermal efficiency. Experimental results show that the flowing-over PV/T system with Al2O3 nanofluid as working fluid has a higher overall efficiency than that with water.

scholarly journals Numerical Performance Investigation of Hybrid PV/Thermal System

2018 ◽  
Vol 7 (4.19) ◽  
pp. 818
Author(s):  
Kadhim K. Idan Al-Chlaihawi ◽  
Dhafer A. Hamzah ◽  
Ahmed K. Zarzoor ◽  
Yousif M. Hasan
Keyword(s):  
Solar Radiation ◽  
Water Temperature ◽  
Flow Rate ◽  
Cooling Water ◽  
Electrical Performance ◽  
Flow Rates ◽  
Electrical Efficiency ◽  
Cooling Water Temperature ◽  
Present Work Deal ◽  
Numerical Performance

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 performance than serpentine absorber where the value of  of spiral absorber is increased by about 5.2% compared to the value of serpentine absorber, on the other hand, the rate of heat loss ( decreased by about 10%.Increasing initial cooling water temperature degrades electrical efficiency of PVT system.  

scholarly journals Analysis of a novel high performance induction air heater

2018 ◽  
Vol 22 (Suppl. 3) ◽  
pp. 843-853 ◽  
Author(s):  
Umit Unver ◽  
Ahmet Yuksel ◽  
Alper Kelesoglu ◽  
Fikret Yuksel ◽  
Halil Unver
Keyword(s):  
Flow Field ◽  
Cross Section ◽  
Flow Rate ◽  
Thermal Efficiency ◽  
High Performance ◽  
Control Volume ◽  
Thermal Power ◽  
Heat Losses ◽  
Flow Rates ◽  
Air Mass

This study represents an experimental and numerical investigation of the enhanced prototypes of the induction air heaters. For this purpose, flow field is enhanced in order to avoid turbulence. The air mass flow rate, outlet construction and the application of insulation of the outer surface of the heater were selected as the performance enhancing parameters. Depending on the exit construction, the new designed prototypes are named as K-2 and K-3. Experiments were performed under two groups for three various flow rates. In the first group, non-insulation situation is examined. In the second group tests, insulation is applied to the outside of windings and inlet-outlet flaps which constitute the boundary of the control volume for the prevention of heat losses. The increasing flow rate boosted the thermal efficiency by 9%. Each of insulation and enlarging exit cross section increased the thermal efficiency by 13%. It was observed that the thermal power transferred to air with the new prototypes increased about 246 W more than the previous designs. The thermal efficiencies of the K-2 and K-3 type heaters were calculated as 77.14% and 87.1%, respectively.

scholarly journals Modeling of Bifacial Photovoltaic-Thermal (PVT) Air Heater with Jet Plate

2021 ◽  
Vol 39 (4) ◽  
pp. 1117-1122
Author(s):  
Win Eng Ewe ◽  
Ahmad Fudholi ◽  
Kamaruzzaman Sopian ◽  
Nilofar Asim
Keyword(s):  
Mass Flow Rate ◽  
Air Temperature ◽  
Mass Flow ◽  
Flow Rate ◽  
Thermal Efficiency ◽  
Solar Irradiation ◽  
Electrical Efficiency ◽  
Air Heater ◽  
Packing Factor ◽  
Pv Panel

This research demonstrates how to develop a novel energy balance equation to investigate heat transmission between the components of a bifacial photovoltaic-thermal (PVT) air heater with a jet plate. The temperature output and efficiency of the system are shown. A greater mass flow rate reduces the exit air temperature and increases the thermal efficiency of the thermal component. Increased sun irradiation raises the output air temperature and thermal efficiency. In terms of electrical efficiency, a greater mass flow rate reduces the temperature of the PV panel while increasing electrical efficiency. On the other hand, higher solar irradiation raises the temperature of the PV panel, lowering its electrical efficiency. The maximum thermal efficiency of BPVTJPR is 51.09% under the circumstances of 12 PV cells with a packing factor of 0.66, a jet plate reflector with 36 holes, 900 W/m2 solar irradiances, and a mass flow rate of 0.035 kg/s. The maximum electrical efficiency of BPVTJPR is 10.73% under the circumstances of 12 PV cells with a packing factor of 0.66, a jet plate reflector with 36 holes, 700 W/m2 solar irradiances, and a mass flow rate of 0.035 kg/s.

Experimental investigation of the novel BIPV/T system employing micro-channel flat-plate heat pipes

2018 ◽  
Vol 39 (5) ◽  
pp. 540-556 ◽  
Author(s):  
Zhangyuan Wang ◽  
Zicong Huang ◽  
Fucheng Chen ◽  
Xudong Zhao ◽  
Peng Guo
Keyword(s):  
Heat Transfer ◽  
Flat Plate ◽  
Water Flow ◽  
Thermal Energy ◽  
Thermal Efficiency ◽  
Heat Pipes ◽  
Micro Channel ◽  
Plate Heat ◽  
Electrical Efficiency ◽  
T System

In this paper, the micro-channel flat-plate heat pipes-based BIPV/T system has been proposed, which is expected to have the characteristics, e.g. reduced contact thermal resistance, enhanced heat transfer area, improved heat transfer efficiency and building integration. The proposed system was constructed at the laboratory of Guangdong University of Technology (China) to study its performance. The temperatures of the glass cover, PV panel, micro-channel flat-plate heat pipes, and tank water were measured, as well as the ambient temperature. The thermal and electrical efficiency was also calculated for the system operated under the conditions with different simulated radiations and water flow rates. It was found that the proposed system can achieve the maximum average overall efficiency of 50.4% (thermal efficiency of 45.9% and electrical efficiency of 4.5%) for the simulated radiation of 300 W/m2 and water flow rate of 600 L/h. By comparing the proposed system with the two previous systems employing the conventional heat pipes, the thermal efficiency of the proposed system was clearly improved. The research will develop an innovative BIPV/T technology possessing high thermal conduction capability and high thermal efficiency compared with the conventional BIPV/T system, and helps realise the global targets of reducing carbon emission and saving primary energy in buildings. Practical application: This novel BIPV/T employing micro-channel flat-plate heat pipes will be potentially used in buildings to provide amount of electricity and thermal energy. The generated electricity will be used by the residents for electrical devices, and the thermal energy can be used for hot water, even for space heating and cooling.

Sign in / Sign up

Export Citation Format

Share Document