scholarly journals Numerical simulation of concentrating solar collector P2CC with a small concentrating ratio

2012 ◽  
Vol 16 (suppl. 2) ◽  
pp. 471-482 ◽  
Author(s):  
Velimir Stefanovic ◽  
Sasa Pavlovic ◽  
Marko Ilic ◽  
Nenad Apostolovic ◽  
Dragan Kustrimovic
Keyword(s):  
Mathematical Model ◽  
Fluid Flow ◽  
Solar Radiation ◽  
Solar Energy ◽  
Radiation Intensity ◽  
Solar Collector ◽  
Numerical Procedure ◽  
Working Fluid ◽  
Flow Rates ◽  
Solar Radiation Intensity

Solar energy may be practically utilized directly through transformation into heat, electrical or chemical energy. A physical and mathematical model is presented, as well as a numerical procedure for predicting thermal performances of the P2CC solar concentrator. The demonstrated prototype has the reception angle of 110? at concentration ratio CR = 1.38, with the significant reception of diffuse radiation. The solar collector P2CC is designed for the area of middle temperature conversion of solar radiation into heat. The working fluid is water with laminar flow through a copper pipe surrounded by an evacuated glass layer. Based on the physical model, a mathematical model is introduced, which consists of energy balance equations for four collector components. In this paper, water temperatures in flow directions are numerically predicted, as well as temperatures of relevant P2CC collector components for various values of input temperatures and mass flow rates of the working fluid, and also for various values of direct sunlight radiation and for different collector lengths. The device which is used to transform solar energy to heat is referred to as solar collector. This paper gives numerical estimated changes of temperature in the direction of fluid flow for different flow rates, different solar radiation intensity and different inlet fluid temperatures. The increase in fluid flow reduces output temperature, while the increase in solar radiation intensity and inlet water temperature increases output temperature of water. Furthermore, the dependence on fluid output temperature is determined, along with the current efficiency by the number of nodes in the numerical calculation.

scholarly journals Developing mathematical models for global solar radiation intensity estimation at Shakardara, Kabul

2021 ◽  
Vol 4 (2) ◽  
pp. 133-138
Author(s):  
Abdul Basit Da’ie
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Mathematical Models ◽  
Radiation Intensity ◽  
Global Solar Radiation ◽  
Suitable Model ◽  
Intensity Estimation ◽  
Solar Radiation Intensity ◽  
Sunshine Hours ◽  
Atmospheric Data

Solar energy properties such as Global Solar Radiation (GSR) intensity could be determined in either methods, experimentally or theoretically. Unfortunately, in most countries including Afghanistan, the first method which is more acceptable, but due to the high cost, maintenance and calibration requirements is not available. Therefore, an alternative widely used way is the second one which is model developments based on the meteorological (atmospheric) data; specially the sunny hours. The aim of this study at Shakardara area is to estimate atmospheric transparency percentage on 2017, determining the angstrom model coefficients and to introduce a suitable model for global solar radiation prediction. The hourly observed solar radiation intensity H (WHm-2 ) and sunshine hours S (

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.

Thermochemical Conversion of Biomass Using Solar Energy: Use of Nanoparticle-Laden Molten Salt as the Working Fluid

2009 ◽  
Author(s):  
Himanshu Tyagi ◽  
Patrick E. Phelan ◽  
Ravi S. Prasher
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Molten Salt ◽  
Concentration Factor ◽  
Solar Collector ◽  
Energy Use ◽  
Operating Conditions ◽  
Thermochemical Conversion ◽  
Working Fluid ◽  
Fluid Mixture

Solar energy can potentially be used to convert biomass into more readily usable fuel. The use of solar energy in such a process improves the overall conversion efficiency of the system significantly by eliminating combustion of a portion of biomass needed to heat the rest of it to a temperature where pyrolysis occurs. The present study models the thermochemical conversion process during pyrolysis of biomass matter into product gases. Concentrated solar radiation is used as the source of heating of the biomass. The biomass is indirectly heated by a mixture of molten salts (Na2CO3 and K2CO3) and nanoparticles (copper), which acts as the absorbing medium and in turn heats the biomass matter (cellulose). A two-stage heat transfer and chemical reaction analysis is carried out in order to simulate the simplified operating conditions of a solar-powered gasifier. The temperature of the molten salt at the exit of the reactor is held fixed at 1000 K (727°C). The calculations are carried out at different values of solar concentration factor ranging from 10 to 60. The results show that the temperature of the molten salt mixture at the exit of the solar collector increases with an increase in the solar concentration factor. Moreover the temperature inside the biomass reactor is a function of the concentration factor as well and largely the determining factor of the rate of biomass conversion into product gases. At the highest concentration factor (Cf = 60), the model predicts that the reactor is able to convert 1.1 tons of biomass into product gases each hour using 900 kW of solar radiation at an overall efficiency of 8%. The main finding of this study is that under similar operating conditions a solar collector using a direct absorption fluid (mixture of nanoparticles and molten salt) would require significantly less concentration factor (an order of magnitude reduction) than a conventional solar collector. A conventional solar collector is defined as one where the solar radiation heats up a solid surface (such as tube walls) which in turn heats up the working fluid (molten salt). Such a reduction in concentration factor would translate into lower concentrator area, and consequently lower initial capital cost.

scholarly journals Decaffeination process characteristic of Robusta coffee in single column reactor using ethyl acetate solvent

2009 ◽  
Vol 26 (3) ◽  
Author(s):  
Sukrisno Widyotomo ◽  
Sri Mulato ◽  
Hadi K. Purwadaria ◽  
A.M Syarief
Keyword(s):  
Energy Efficiency ◽  
Solar Radiation ◽  
Solar Energy ◽  
Energy Conversion ◽  
Conversion Efficiency ◽  
Radiation Intensity ◽  
Energy Conversion Efficiency ◽  
Solar Radiation Intensity ◽  
Solar Energy Conversion Efficiency ◽  
Shading Plant

AbstractThis experiment aims to know the solar energy efficiency of four clones of cocoa that cultivated under three different shading plants. This experiment has been done from September until December 2013 located at Kaliwining Experiment Farm with characteristic 45 m above sea level, soil type is low humic gley, soil texture is silty clay loam, and climate classification type D based on Scmidht and Fergusson Classification. This experiment used Nested Design as Experimental Design with species of shading plant as main plot which are Teak (Tectona grandis L.), Krete (Cassia surattensis (Burm.) F.), Lamtoro (Leucaena leucocephala L.) and Cocoa clones as sub plot which are Sulawesi 1, Sulawesi 2, KKM 22, KW 165. The observation of solar energy efficiency consists of daily solar radiation intensity, solar radiation intensity above plant, solar radiation intensity under plant, and also plant total dry weight. The experimental result showed that there is differences (heterogenity) between shading location based on homogenity test by Bartlett Method. There are some interaction between the kind of shading plant and clones in parameter of interception efficiency, absorbtion efficiency, the efficiency of solar energy that caught by plant, and solar energy conversion efficiency. The efficiency of solar energy that caught by plant will affect the solar energy conversion efficiency with R2 = 0,86.  Keywords : Solar Energy Efficiency, Cocoa Clones, Shading Plant, Nested Design, Bartlett Method

scholarly journals Level of Coffee Consumption in Urban Community and Its Determinant Factors: Case Study in Jember District

2009 ◽  
Vol 25 (3) ◽  
Author(s):  
Endang Wiji Lestari ◽  
Idha Haryanto ◽  
Surip Mawardi
Keyword(s):  
Energy Efficiency ◽  
Solar Radiation ◽  
Solar Energy ◽  
Energy Conversion ◽  
Conversion Efficiency ◽  
Radiation Intensity ◽  
Energy Conversion Efficiency ◽  
Solar Radiation Intensity ◽  
Solar Energy Conversion Efficiency ◽  
Shading Plant

AbstractThis experiment aims to know the solar energy efficiency of four clones of cocoa that cultivated under three different shading plants. This experiment has been done from September until December 2013 located at Kaliwining Experiment Farm with characteristic 45 m above sea level, soil type is low humic gley, soil texture is silty clay loam, and climate classification type D based on Scmidht and Fergusson Classification. This experiment used Nested Design as Experimental Design with species of shading plant as main plot which are Teak (Tectona grandis L.), Krete (Cassia surattensis (Burm.) F.), Lamtoro (Leucaena leucocephala L.) and Cocoa clones as sub plot which are Sulawesi 1, Sulawesi 2, KKM 22, KW 165. The observation of solar energy efficiency consists of daily solar radiation intensity, solar radiation intensity above plant, solar radiation intensity under plant, and also plant total dry weight. The experimental result showed that there is differences (heterogenity) between shading location based on homogenity test by Bartlett Method. There are some interaction between the kind of shading plant and clones in parameter of interception efficiency, absorbtion efficiency, the efficiency of solar energy that caught by plant, and solar energy conversion efficiency. The efficiency of solar energy that caught by plant will affect the solar energy conversion efficiency with R2 = 0,86.  Keywords : Solar Energy Efficiency, Cocoa Clones, Shading Plant, Nested Design, Bartlett Method

scholarly journals Simulation Research on the Heating Performance of the Combined System of Solar Energy and Heat-Source Tower Heat Pump in a Hot Summer and Cold Winter Area

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1816
Author(s):  
Xiaohang Shen ◽  
Nianping Li ◽  
Yongga A
Keyword(s):  
Solar Radiation ◽  
Heat Source ◽  
Heat Pump ◽  
Radiation Intensity ◽  
Solar Collector ◽  
Outdoor Air ◽  
Heating Systems ◽  
Heating Performance ◽  
Solar Radiation Intensity ◽  
In Series

Three connection methods for the combined heating systems of a closed-type heat-source tower heat pump (CHTHP) and solar collector (SC) were proposed in this paper: the heat-source tower (HST) and solar collector were connected in series (HST+SC), and the solar collector and heat pump (HP) condenser were connected in series (SC+HP) and in parallel (SC//HP). The calculation module of the closed heat-source tower was built using programming software based on C++ language, and three corresponding calculation models of the combined heating systems were established in the TRNSYS. Under the climatic conditions of the cold season in Changsha, the combined heating performance of the three systems was simulated and analyzed. The results indicate that the simulation results of the established models are in good agreement with the test results, and the simulation results can be used for the research of the system’s combined heating performance. When the outdoor air temperature and solar radiation intensity are low, the HST+SC system has the best heating performance; however, when the solar radiation intensity and ambient temperature are high, the heating performance of the SC//HP system is the best. When the solar radiation intensity and outdoor air temperature are between the previous two working conditions, the SC+HP system is the best performer for heating among the three systems. On the basis of the collector area and heat pump power designed in this study, the best operating condition interval diagrams of the three combined heating systems are established.

scholarly journals Isolation of Indigenous Phytophthora palmivora from Indonesia, Their Morphological and Pathogenecity Characterization

2008 ◽  
Vol 24 (1) ◽  
Author(s):  
Rubiyo Rubiyo ◽  
Agus Purwantara ◽  
Sri Sukamto ◽  
Sudarsono Sudarsono
Keyword(s):  
Energy Efficiency ◽  
Solar Radiation ◽  
Solar Energy ◽  
Energy Conversion ◽  
Conversion Efficiency ◽  
Radiation Intensity ◽  
Energy Conversion Efficiency ◽  
Solar Radiation Intensity ◽  
Solar Energy Conversion Efficiency ◽  
Shading Plant

AbstractThis experiment aims to know the solar energy efficiency of four clones of cocoa that cultivated under three different shading plants. This experiment has been done from September until December 2013 located at Kaliwining Experiment Farm with characteristic 45 m above sea level, soil type is low humic gley, soil texture is silty clay loam, and climate classification type D based on Scmidht and Fergusson Classification. This experiment used Nested Design as Experimental Design with species of shading plant as main plot which are Teak (Tectona grandis L.), Krete (Cassia surattensis (Burm.) F.), Lamtoro (Leucaena leucocephala L.) and Cocoa clones as sub plot which are Sulawesi 1, Sulawesi 2, KKM 22, KW 165. The observation of solar energy efficiency consists of daily solar radiation intensity, solar radiation intensity above plant, solar radiation intensity under plant, and also plant total dry weight. The experimental result showed that there is differences (heterogenity) between shading location based on homogenity test by Bartlett Method. There are some interaction between the kind of shading plant and clones in parameter of interception efficiency, absorbtion efficiency, the efficiency of solar energy that caught by plant, and solar energy conversion efficiency. The efficiency of solar energy that caught by plant will affect the solar energy conversion efficiency with R2 = 0,86.  Keywords : Solar Energy Efficiency, Cocoa Clones, Shading Plant, Nested Design, Bartlett Method

scholarly journals Solar Energy Efficiency of Cocoa Clones which Cultivated under Three Species of Shade Trees

2015 ◽  
Vol 31 (1) ◽  
pp. 21-29
Author(s):  
Oscar Regazzoni ◽  
Yogi Sugito ◽  
Agus Suryanto ◽  
Adi Prawoto
Keyword(s):  
Energy Efficiency ◽  
Solar Radiation ◽  
Solar Energy ◽  
Energy Conversion ◽  
Conversion Efficiency ◽  
Radiation Intensity ◽  
Energy Conversion Efficiency ◽  
Solar Radiation Intensity ◽  
Solar Energy Conversion Efficiency ◽  
Shading Plant

AbstractThis experiment aims to know the solar energy efficiency of four clones of cocoa that cultivated under three different shading plants. This experiment has been done from September until December 2013 located at Kaliwining Experiment Farm with characteristic 45 m above sea level, soil type is low humic gley, soil texture is silty clay loam, and climate classification type D based on Scmidht and Fergusson Classification. This experiment used Nested Design as Experimental Design with species of shading plant as main plot which are Teak (Tectona grandis L.), Krete (Cassia surattensis (Burm.) F.), Lamtoro (Leucaena leucocephala L.) and Cocoa clones as sub plot which are Sulawesi 1, Sulawesi 2, KKM 22, KW 165. The observation of solar energy efficiency consists of daily solar radiation intensity, solar radiation intensity above plant, solar radiation intensity under plant, and also plant total dry weight. The experimental result showed that there is differences (heterogenity) between shading location based on homogenity test by Bartlett Method. There are some interaction between the kind of shading plant and clones in parameter of interception efficiency, absorbtion efficiency, the efficiency of solar energy that caught by plant, and solar energy conversion efficiency. The efficiency of solar energy that caught by plant will affect the solar energy conversion efficiency with R2 = 0,86.  Keywords : Solar Energy Efficiency, Cocoa Clones, Shading Plant, Nested Design, Bartlett Method

scholarly journals IMPROVING THE EFFICIENCY OF THE SYSTEM WITH SOLAR COLLECTORS

2021 ◽  
pp. 100-103
Author(s):  
Мар'яна Касинець ◽  
Марта Кузнєцова ◽  
Ірина Сухолова ◽  
Олександра Дацько
Keyword(s):  
Solar Radiation ◽  
Radiation Intensity ◽  
Solar Collector ◽  
Theoretical Calculations ◽  
Azimuth Angle ◽  
Thermal Engineering ◽  
Parameter Study ◽  
Solar Collectors ◽  
Incident Intensity ◽  
Solar Radiation Intensity

The paper solves an important issue of the efficiency of two collectors that have different orientations at different angles of incidence of solar radiation intensity. That is why the paper carries out a wide-parameter study of their thermal engineering characteristics. It is investigated that the change in the azimuth angle α from 90º to 60º, under the φ=90º does not significantly affect the efficiency of the system with solar collectors, and its further deviation significantly reduces. It is also established that the simultaneous deviation of angles α and φ leads to a significant reduction in the use of the incident intensity of solar radiation on the solar collector and the efficiency of the system with solar collectors in general. As a result of theoretical calculations its average annual value is obtained , accordingly for a different number of discrete collector orientations N.

Experimental Study on Influence of High-Borosilicate Glass Transmittance on Solar Cooling Tube Thermal Performances

2011 ◽  
Vol 225-226 ◽  
pp. 324-327 ◽  
Author(s):  
Fei Chen ◽  
Hui Zhong Zhao
Keyword(s):  
Experimental Study ◽  
Solar Radiation ◽  
Thermal Performance ◽  
Borosilicate Glass ◽  
Radiation Intensity ◽  
Solar Collector ◽  
Solar Cooling ◽  
Solar Radiation Intensity ◽  
Cooling Tube ◽  
Glass Tubes

The experiment to test the solar radiation intensity through borosilicate glass tubes with a variety of different radius of curvatures and different qualities are taken on condition that the solar radiation intensity is from 23 W/㎡to1022W/㎡. When the diameter increasing to 65mm from 58mm, the single high-borosilicate glass tube’s transmittance changes to 93.2% from 93.5% and double’s transmittance changes to 88.2% from 90.1% .When high-borosilicate glass tube’s wall thickness is uniform and non-uniform, the transmittance is nearly the same. We can decrease the sleeve’s diameter to 58mm and the of evacuated solar collector outer tube’s diameter to improve the thermal performance of the cooling tube.

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