scholarly journals Nanofluids for Solar Thermal Collection and Energy Conversion

Author(s):  
Mohammed Abdullah Hussain ◽  
Sumith Yesudasan ◽  
Sibi Chacko

This paper investigates the improvement in solar energy collection and conversion using Al2O3-Water nanofluids in a solar flat plate collector (SFPC). The efficiency of a solar flat plate collector using water as the fluid medium is analyzed experimentally and theoretically. For theoretical analysis, a mathematical model in MATLAB is used to simulate and is validated by the experimental results. To enhance the solar energy collection and conversion efficiency of the SFPC, Al2O3-Water nanofluid was selected as the fluid medium. The nanofluid properties like density, specific heat capacity, thermal conductivity and viscosity are analyzed and compared for several models of Al2O3-Water nanofluids and the best model was selected to modify the simulation. Effect of particle diameter in the nanofluid was found to be marginal on the nanofluid properties. The optimum volume concentration of the nanofluid was found to be 4% giving an efficiency increase of 7.78% in the SFPC over the use of water. This reduces the area of the SFPC by 10.5%.

2021 ◽  
pp. 100028
Author(s):  
L. Syam Sundar ◽  
V. Punnaiah ◽  
Manoj K. Singh ◽  
António M.B. Pereira ◽  
António C.M. Sousa

2014 ◽  
Vol 592-594 ◽  
pp. 2404-2408 ◽  
Author(s):  
Sunita Meena ◽  
Chandan Swaroop Meena ◽  
V.K. Bajpai

Solar energy collectors are a special kind of heat exchangers that transform solar radiation energy to internal energy of the transport medium. The major component of any solar system is the solar collector. This is a device which absorbs the incoming solar radiation, converts it into heat, and transfers this heat to a fluid (usually air, water, or oil) flowing through the collector. The measurement of the flat plate collector performance is the collector efficiency. The collector efficiency is the ratio of the useful energy gain to the incident solar energy over a particular period of time. The useful energy gain is strongly depends on the collector efficiency factor and this factor directly influenced by few parameters i.e. the centre to centre distance of absorber tubes W , thickness of absorber plate δ and heat loss coefficient UL. This paper has been focused on the relation between W with collector efficiency factor of serpentine tube solar flat-plate collector. This study shows that if we increase the W then Fˈ decreases.


2013 ◽  
Vol 368-370 ◽  
pp. 1228-1231
Author(s):  
Fen E Hu ◽  
Sheng Xian Wei ◽  
Neng Bang Hou

A solar radiation model to determine solar energy collection on solar collector array with different aspect ratios has been developed. The relations between the aspect ratio and the average daily solar radiation collection on the collector array have been deeply studied. The results show that there is an optimum aspect ratio to maximize the solar energy collection on the collector arrays. The optimum aspect ratios of the 1000 m2 collector array for Haikou, Kunming, Lhasa and Beijing are 10/1, 1/3, 5/1 and 10/1.The optimum aspect ratios of 1000 m2, 500 m2, 200 m2 and 100 m2 collector arrays for Kunming are 1/3, 3/1, 7/1 and 1/5, respectively.


Author(s):  
Luqman Ahmed Pirzada ◽  
Xiaoli Wu . ◽  
Qaiser Ali ◽  
Asif Khateeb .

Solar energy is radiant light as a form of thermal heat energy which can be obtained and used by means of a variety of solar apparatus. As apparatus the flat and curved plate solar collector is specifically designed for assembling solar energy as a solar water heater system. The designing potency of this collector lone can generate medium level hot water from radiant sunlight source via absorbed plates. Standard type flat and curved plates solar collector plates are mostly used in remote coldest regions of the world where hot water is consumed for commercial and domestic purposes. These types of solar collector Plates can cheaply be manufactured compared to other solar panels like solar Shingles, Polycrystalline Solar Panels, Mono-crystalline Solar Panels, and Thin Film Solar Panels. For future work, this proposed pre-design is recommended for fabrication. A numerical study was carried-out on eight city locations in China by tracing their horizontal and vertical longitudinal, latitudinal lines noting the date, time and sunlight feeding of temperatures in the Celsius scale with the help of simulation and modeling tools like CFD, ANSYS FLUENT software, mesh geometry tools, and by using the Navier-Stokes and Continuity equations by fluid flow discharge rate, mass flow, water temperature and dropping of temperature, radiation working mechanisms, dimensions of water flowing tubes and absorber plates, density, the velocity of water as the working fluid, the viscosity of water in a cold and hot state as a process of Pre-design. Work also focuses on the comparison between flat plate collector and curved plate collector radiant sunlight absorption, As end result it is found the Curved plate collector produces 22% more elevated heat of outgoing water than flat plate collector.


Processes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 180 ◽  
Author(s):  
Bahaa Saleh ◽  
Lingala Syam Sundar

The heat transfer, friction factor, and collector efficiency are estimated experimentally for multi-walled carbon nanotubes+Fe3O4 hybrid nanofluid flows in a solar flat plate collector under thermosyphon circulation. The combined technique of in-situ growth and chemical coprecipitation was utilized to synthesize the multi-walled carbon nanotubes+Fe3O4 hybrid nanoparticles. The experiments were carried out at volume flow rates from 0.1 to 0.75 L/min and various concentrations from 0.05% to 0.3%. The viscosity and thermal conductivity of the hybrid nanofluids were experimentally measured at different temperatures and concentrations. Due to the improved thermophysical properties of the hybrid nanofluids, the collector achieved better thermal efficiency. Results show that the maximum thermal conductivity and viscosity enhancements are 28.46% and 50.4% at 0.3% volume concentration and 60 °C compared to water data. The Nusselt number, heat transfer coefficient, and friction factor are augmented by 18.68%, 39.22%, and 18.91% at 0.3% volume concentration and 60 °C over water data at the maximum solar radiation. The collector thermal efficiency improved by 28.09% at 0.3 vol. % at 13:00 h daytime and a Reynolds number of 1413 over water data. Empirical correlations were developed for friction factor and Nusselt number.


2013 ◽  
Author(s):  
P. Rhushi Prasad ◽  
P. B. Gangavati ◽  
H. V. Byregowda ◽  
K. S. Badarinarayan

Now-a-days the field of applied mechanical systems opens new horizons for the use of orientation mechanisms. The opportunity to use mechanisms with a “sustainable purpose” leads to new approaches in the development of renewable energy systems design. The evaluation of the existing products shows that the tracking mechanisms for solar energy conversion systems may improve the efficiency of the solar energy conversion systems up to 30% to 50%. Applications of solar energy for domestic and industrial heating purposes have been becoming very popular. However the effectiveness of presently used fixed flat plate collectors, PV panels and parabolic collector are low due to the moving nature of the energy source. The presents research was carried out in the field of increasing the efficiency of the solar energy received by the solar collectors like PV panels, Flat plate collectors, Cylindrical Parabolic collectors using tracking systems by changing the position of the solar collectors correlated to the sun position for getting maximum radiation use of beam radiation falling on the solar collector. Two main aspects are taken into consideration, one optimizing the interaction between the mechatronic system components by integrating the analog electronic system by using a 555 timer in the mechanical model, and secondly by reducing the cost & time for the design process. The research work was carried out for location in chickballapur district at BGS R&D centre in Karnataka State, India. The results obtained in work is 24% increase in tracking efficiency of experimental model of flat plate collector, 30% increase in tracking efficiency in working model flat plate collector, 39 % increase in tracking efficiency of cylindrical parabolic collector and 36% increases in tracking efficiency of the Photovoltaic panel is found when compared to the non-tracking systems respectively. This paper presents the results of PV panel collector in detail for increasing the efficiency of the PV panel collector by tracking system with comparison of non-tracking system.


Solar Energy ◽  
1988 ◽  
Vol 40 (4) ◽  
pp. 295-307 ◽  
Author(s):  
H.P. Garg ◽  
D.S. Hrishikesan

Author(s):  
P. Rhushi Prasad ◽  
P. B. Gangavati ◽  
H. V. Byregowda ◽  
K. S. Badarinarayan

Nowadays the field of applied mechanical systems opens new horizons for the use of orientation mechanisms. The opportunity to use mechanisms with a “sustainable purpose” leads to new approaches in the development of renewable energy systems design. In literature review many authors says the evaluation of the existing products shows that the tracking mechanisms for solar energy conversion systems may improve the efficiency of the solar energy conversion systems up to 30% to 50%. Applications of solar energy for domestic and industrial heating purposes are becoming very popular. However the effectiveness of presently used fixed flat plate collectors, photovoltaic panels and parabolic collector are low due to the moving nature of the energy source. This paper presents researches in the field of increasing the efficiency of the solar energy conversion by using tracking systems with flat plate collector of solar water heating system with the aim to change the position of the solar collector/solar panels correlated to the sun position for maximizing the use of beam radiation by real time digital tracking method. H.V. Byregowda et.al. optimized the interaction between the mechatronic system components by integrating the analog electronic system by using a 555 timer in the mechanical model by designing a single axis low cost tracking system of experimental model in order to reduce cost and show improvement in efficiency of tracking systems before beginning with the virtual prototype level. The work done by these authors was at chickballapur location in BGS R&D centre, SJCIT College. The result Obtained in their research work is that, the thermal efficiency was increased by 21% with tracking of manual method and by 24% with analog method of automatic tracking system. In the present work, a new method of tracking system has been developed electronically with solar water heating systems used in homes for water heating and Power utilization as multiple purpose domestic applications by adding real time clock (RTC) digital, microcontroller, DC motor, Electronics circuit board, batteries and photovoltaic panels along with water tank, flat plate collector which are existing at present in homes only for water heating applications. The results obtained in present work of digital tracking system the thermal efficiency of experimental working model of flat plate collector shows 30% increase when compared with tracking system and non tracking system.


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