Determination of the performance improvement of a PV/T hybrid system with a novel inner plate-finned collective cooling with Al₂O₃ nanofluid

ABSTRACT

In order to increase module efficiency in photovoltaic systems, research on passive fin cooling or active fluid cooling applications continues. It was thought that a collective cooling, which is a combination of both applications, could be more effective on the increasing electrical efficiency and so the increase of the total efficiency of the PV/T system by increasing the thermal gain. In this study, the effects of the amounts of nanoparticles on the electrical and thermal performance of the Al₂O₃ nanofluid in a newly designed, manufactured system which is named collective cooling system with internal direct fins were investigated in detail. Nanofluid coolants were prepared with the use of Al₂O₃ nanoparticles at a mass ratio of 0.2%, 0.4% and 0.6% and they were used in the system at constant mass flow rates. The highest panel temperature drop was observed as 17.3 °C and corresponding power increase rate was observed as 6.11% in the panel with 0.4% Al₂O₃-water nanofluid at 12:00. The averages of daily power increase rates for 0.2%, 0.4%, 0.6% of Al₂O₃-water nanofluid cooling compared to the uncooled panel were 3.862%, 3.286%, 3.238% and 2.693% for the water-cooled panel, respectively. Compared to the water-cooled panel, the Al₂O₃-water nanofluid panel has average thermal efficiency increases of 39.77%, 28.92% and 15.92%, respectively, for 0.2%, 0.4%, and 0.6%.

KEYWORDS:

• PV/T systems
• PV cooling
• nanofluids
• PV panel efficiency
• Al₂O₃

Nomenclature

Al2O3	=	Aluminum OxidePElectrical Power
Ac	=	Fin Cross Section AreaPaPower Increase
Aps	=	The Entire Heat Transfer Surface AreaPcPower of Cooled Panel
Ap	=	Ratio of the Cross-Sectional Area${\eta }_{es}$Efficiency of Cooled Panel
Cc	=	Current of Cooled Panel${\eta }_{th}$The Thermal Efficiency
Cn	=	Current of Normal PanelPElectrical Power
Ç	=	Circumference of the ChannelPLPower of the Plate-Finned Panel
Çk	=	Fin CircumferencePnPower of Normal Panel
E	=	Channel WidthTfFilm Temperature
Isc	=	Short-Circuit CurrentTAAmbient Temperature
H	=	Convectional Heat CoefficientTgTemperature of Inlet Liquid
Lt	=	The Thermal Development LengthTcupTemperature of Upper Point of Cooled Panel Surface
Lk	=	Channel Length (M),TcmidTemperature of Mid Point of Cooled Panel Surface
H	=	Channel HeightTcdownTemperature of Down Point of Cooled Panel Surface
Ṁ	=	Mass Flow Rate of CoolantTçTemperature of Outlet Liquid
N	=	Number of FinsTupTemperature of Upper Point of Panel Surface
Ƞc	=	The Efficiency Cooled PanelTmidTemperature of Mid Point of Panel Surface
Ƞa	=	Electrical Efficiency IncreaseTdownTemperature of Down Point of Panel Surface
${\eta }_e$Efficiency Of Uncooled Pan	=	el$\mathrm{\Delta }Tln$Logarithmic Mean Temperature Difference
$\mu$	=	:Dynamic ViscositySTCStandard Test Conditions
${\mu }_{nf}$Dynamic Viscosity of	=	Al2O3 Nanofluid$Q_R$Heat Gain
${\mu }_w$Dynamic Viscosity of Base Flu	=	id$\varphi$Volume Rate
Pa	=	Power Increase$\rho$Density
Pc	=	Power of Cooled PanelVocOpen-Circuit Voltage
${\eta }_{es}$Efficiency of Cooled Pan	=	elVnVoltage of Normal Panel
${\eta }_{th}$The Thermal Efficien	=	cyVcVoltage of Cooled Panel

Acknowledgements

Data in this research was the results of the PhD thesis project by Batman University Institute of Science with Thesis Number of 637470. The research was performed at the Engine Research Laboratory, University of Batman, Batman, Turkey.

Disclosure statement

No potential conflict of interest was reported by the author(s).