scholarly journals The use of paraffin wax in a new solar cooker with inner and outer reflectors

2015 ◽  
Vol 19 (5) ◽  
pp. 1663-1671 ◽  
Author(s):  
Bihter Arabacigil ◽  
Numan Yuksel ◽  
Atakan Avci
Keyword(s):  
Solar Radiation ◽  
Thermal Efficiency ◽  
Heating Time ◽  
Peak Temperature ◽  
Paraffin Wax ◽  
Optimum Angle ◽  
Surface Temperatures ◽  
Late Evening ◽  
Reflecting Surface ◽  
Potential Use

In this paper, the potential use and effectiveness of paraffin wax in a new solar cooker was experimentally investigated during daylight and late evening hours. For these experiments, a cooker having an inner reflecting surface was designed, constructed by filling paraffin wax and metal shavings. The side- and sub-surface temperatures of the paraffin wax in the cooker are measured in the summer months of June and July. The thermal efficiency of the cooker was tested on different conditions. The results show that the optimum angle of the outer reflector is 30?. Here, the peak temperature of the paraffin wax in the solar cooker was 83.4 ?C. The average solar radiation reflected makes a contribution of 9.26% to the temperature of paraffin wax with the outer reflector. The solar cooker with the outer reflector angle of 30? receives also reflected radiation from the inner reflectors. Besides, the heating time is decreased to approximately 1 hour. The designed solar cooker can be effectively used with 30.3% daily thermal efficiency and paraffin wax due to the amount of energy stored.

scholarly journals Investigation of optical and photoelectric properties of poly (ohydroxyamide) sensitized by phthalocyanine as a perspective material for solar cells

2020 ◽  
Vol 220 ◽  
pp. 01019
Author(s):  
Elvira Fazalova ◽  
Konstantin Kochunov ◽  
Elena Bodyago ◽  
Georgii Konoplev ◽  
Nikolay Mukhin ◽  
...  
Keyword(s):  
Thin Films ◽  
Solar Radiation ◽  
Near Infrared ◽  
Wavelength Region ◽  
Organic Dye ◽  
Glass Substrates ◽  
Photoelectric Properties ◽  
Zinc Phthalocyanines ◽  
Infrared Spectral ◽  
Potential Use

Optical and photoelectric properties of poly (ohydroxyamide) (PHA) sensitized with zinc phthalocyanines were investigated in the visible and near infrared spectral regions. The structures were deposited on glass substrates by centrifugation and subsequent drying of a PHA film without thermal annealing. Optical spectra revealed characteristic absorption peaks of phthalocyanine in the longer wavelength region at 620-640 nm and 680-700 nm; absorption of the PHA matrix monotonously increases to the shorter wavelengths starting from 700 nm. Measurements of the photocurrent under irradiation with a high-power LED at a wavelength 630 nm showed photoconductivity related to the organic dye; photoconductivity also was observed while irradiated at 540 nm, presumably due to the absorption of PHA matrix. For non-sensitized (dye-free) PHA films no detectable photocurrents were produced by 630 nm irradiation. It was shown that introducing of phthalocyanines significantly improves optical absorption and photoconductivity of PHA thin films at the wavelengths, where the maximum in the spectral distribution of solar radiation lies. It was concluded that phthalocyanine-sensitized PHA has the potential use as a photosensitive organic material for solar applications, for example in developing composite organicinorganic structures with ferroelectrics.

scholarly journals Analysis of the potential use of Trombe walls in Brazil: design recommendations

2020 ◽  
Vol 5 ◽  
pp. 4
Author(s):  
Fernando Antonio de Melo Sá Cavalcanti ◽  
Rosana Maria Caram
Keyword(s):  
Solar Radiation ◽  
Computer Simulations ◽  
Thermal Performance ◽  
Natural Ventilation ◽  
Solar Heating ◽  
Heating And Cooling ◽  
Heated Air ◽  
Trombe Wall ◽  
Potential Use ◽  
Passive Strategy

In this paper, the thermal performance of a standard environment was evaluated based on the use of a Trombe wall with different configurations and types of use, as the potential for using this passive strategy is still little studied in Brazil. This device is capable of absorbing energy from solar radiation by heating the air in this greenhouse and this heated air can be directed to the interior or exterior of the building depending on the purpose. This air can be used to heat the room or cool it by means of natural ventilation. The analysis of this research was based on a series of computer simulations using the EnergyPlus software, version 7.0 in order to quantify and classify the thermal performance of a standard environment equipped with this component, under the various construction configurations. Both for heating and cooling environments. The use of Trombe walls improved the thermal comfort of users in buildings located in Brazil, depending on the climate where they are located, promoting natural ventilation and passive solar heating, allowing the potential of this device to be investigated in the most diverse Brazilian regions.

scholarly journals Thermodynamic Investigation of an Integrated Solar Combined Cycle with an ORC System

Entropy ◽  
2019 ◽  
Vol 21 (4) ◽  
pp. 428 ◽  
Author(s):  
Wang ◽  
Fu
Keyword(s):  
Solar Radiation ◽  
Thermal Efficiency ◽  
Unit Cost ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Exergy Efficiency ◽  
Combined Cycle ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Exhaust Gas Temperature

An integrated solar combined cycle (ISCC) with a low temperature waste heat recovery system is proposed in this paper. The combined system consists of a conventional natural gas combined cycle, organic Rankine cycle and solar fields. The performance of an organic Rankine cycle subsystem as well as the overall proposed ISCC system are analyzed using organic working fluids. Besides, parameters including the pump discharge pressure, exhaust gas temperature, thermal and exergy efficiencies, unit cost of exergy for product and annual CO2-savings were considered. Results indicate that Rc318 contributes the highest exhaust gas temperature of 71.2℃, while R113 showed the lowest exhaust gas temperature of 65.89 at 800 W/m2, in the proposed ISCC system. The overall plant thermal efficiency increases rapidly with solar radiation, while the exergy efficiency appears to have a downward trend. R227ea had both the largest thermal efficiency of 58.33% and exergy efficiency of 48.09% at 800W/m2. In addition, for the organic Rankine cycle, the exergy destructions of the evaporator, turbine and condenser decreased with increasing solar radiation. The evaporator contributed the largest exergy destruction followed by the turbine, condenser and pump. Besides, according to the economic analysis, R227ea had the lowest production cost of 19.3 $/GJ.

A Numerical Study on Integral Solar Air Collector

2013 ◽  
Vol 860-863 ◽  
pp. 146-150
Author(s):  
Fu Sheng Dong ◽  
Ming Fu Hu ◽  
Xiao Chun Huang
Keyword(s):  
Mathematical Model ◽  
Solar Radiation ◽  
Thermal Efficiency ◽  
Radiation Intensity ◽  
Numerical Study ◽  
One Dimension ◽  
Inlet Temperature ◽  
Solar Radiation Intensity ◽  
Solar Air Collector ◽  
Matlab Programming

A mathematical modeling method was devoted to study the thermal performance of integral solar air collector. A mathematical model of heat transfer was set up based on one-dimension assumptions at first, and then numerical solution was brought out by using finite-difference method under one-dimension steady heat exchange. Through the MATLAB programming, the approximate solutions for the local air temperature and thermal efficiency were obtained at the quasi-steady state. After calculation, the influence of air inlet velocity, inlet temperature, solar radiation intensity and height of flow channel on the performance of collector was analyzed. It is discovered that the mathematical model is reasonable, the thermal efficiency decreases with temperature of inlet air increasing and increases with air velocity increasing, on which the solar radiation intensity have little influence. Depth of the channel and optimum flow both have a best value.

Research on the Outdoor Microclimate of Cold Residence

2011 ◽  
Vol 99-100 ◽  
pp. 220-223
Author(s):  
Jiu Hong Zhang ◽  
Na Wang ◽  
Xu Guo
Keyword(s):  
Solar Radiation ◽  
Physical Properties ◽  
Underlying Surface ◽  
Material Surface ◽  
Surface Material ◽  
Residential Areas ◽  
Infrared Thermometer ◽  
Surface Temperatures ◽  
Properties Of Materials

Research on multiple settlements in Shenyang and the residential areas and ecological areas of Shenyang Jianzhu University, testing the underlying surface material surface temperatures by infrared thermometer and testing the solar radiation by bolometer. Study different material surface temperatures variation. Explore the physical properties of materials effect on the microclimate and draw the appropriate conclusions.

Near-surface temperatures and heat balance of bare outcrops exposed to solar radiation

2011 ◽  
Vol 36 (12) ◽  
pp. 1577-1589 ◽  
Author(s):  
Yann Gunzburger ◽  
Véronique Merrien-Soukatchoff
Keyword(s):  
Solar Radiation ◽  
Heat Balance ◽  
Near Surface ◽  
Surface Temperatures
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