Low-concentrating CPC collectors for photocatalytic water detoxification: comparison with a medium concentrating solar collector

1997 ◽  
Vol 35 (4) ◽  
pp. 157-164 ◽  
Author(s):  
S. Malato ◽  
J. Blanco ◽  
C. Richter ◽  
D. Curcó ◽  
J. Giménez
Keyword(s):  
Solar Radiation ◽  
Solar Collector ◽  
Photocatalytic Oxidation ◽  
Decomposition Reaction ◽  
The Sun ◽  
Parabolic Trough ◽  
Advantages And Disadvantages ◽  
Compound Parabolic Concentrator ◽  
Pilot Plant Scale ◽  
Water Detoxification

The photocatalytic oxidation of 2,4-Dichlorophenol (DCP), using TiO2 suspensions under solar radiation, has been studied at pilot-plant scale at the Plataforma Solar de Almería (PSA). Two different reactor designs were tested: a medium concentrating radiation system called a Parabolic-Trough-Collector Reactor, PTCR, equipped with two motors (azimuth and elevation) to adjust the position of the module perpendicular to the sun, and a low-concentrating radiation system, the Compound-Parabolic-Concentrator Reactor, CPCR, facing south and inclined 37 degrees. Substrates were dissolved in water to required mg L−1 levels in a reservoir tank. In both cases, 0.2 g L−1 of the suspended TiO2 catalyst was used in a 250 L solution of the contaminant, which was recirculated through the photoreactors using a centrifugal pump and an intermediate reservoir tank. The advantages and disadvantages of the two types of photoreactors in DCP oxidation are compared and discussed. The strong potential of photocatalytic peroxydisulphate-assisted degradation in high DCP concentrations was demonstrated in both systems, and chemical actinometry (the decomposition reaction of oxalic acid by radiated uranyl salts) in the CPC reactor is compared with the results obtained in the PTC.

Treatment of 2,4-Dichlorophenol by Solar Photocatalysis: Comparison of Coupled Photocatalytic-Active Carbon vs. Active Carbon

2000 ◽  
Vol 123 (2) ◽  
pp. 138-142 ◽  
Author(s):  
Sixto Malato ◽  
Julia´n Blanco ◽  
Pilar Ferna´ndez-Iba´n˜ez ◽  
Julia Ca´ceres
Keyword(s):  
Organic Carbon ◽  
Solar Radiation ◽  
Total Organic Carbon ◽  
Active Carbon ◽  
Pilot Plant ◽  
Photocatalytic Oxidation ◽  
Practical Application ◽  
Carbon Adsorption ◽  
Pilot Plant Scale ◽  
Slow Kinetic

The photocatalytic oxidation of 2,4-Dichlorophenol (DCP), using TiO2 suspensions under solar radiation, has been studied at pilot-plant scale at the Plataforma Solar de Almerı´a (PSA). This compound is used as a model to demonstrate the practical application of the treatment. Total Organic Carbon (TOC) analysis is applied to confirm the total mineralization of the contaminants. The pilot plant has a volume of 247 L and consists of 9 m2 of CPC modules (with transparent tubes) connected to a recirculation tank. DCP at 20, 50 and 200 mg/L is completely photodegraded in the presence of 200 mg/L of TiO2, but mineralization is slow when organics concentration is small. The results obtained from these experiments have been used to decide the dimensions of a solar photocatalytic plant for treating wastewater contaminated with different concentration of DCP. Due to the slow kinetic obtained in the photodegradation last steps, a combination with GAC treatment is proposed. Besides, this article attempts to compare the advantages, disadvantages and costs of photocatalytic treatment, versus other more conventional technologies such as active carbon adsorption.

TRANSIENT THERMAL PERFORMANCE PREDICTION METHOD FOR PARABOLIC TROUGH SOLAR COLLECTOR UNDER FLUCTUATING SOLAR RADIATION

2016 ◽  
Vol 78 (5-9) ◽  
Author(s):  
Tohru Suwa ◽  
ShyeYunn Heng
Keyword(s):  
Heat Flux ◽  
Solar Radiation ◽  
Thermal Performance ◽  
Performance Prediction ◽  
Solar Collector ◽  
Solar Thermal ◽  
Design Stage ◽  
Parabolic Trough ◽  
Exit Temperature ◽  
Transient Thermal

As the effect of the global warming is becoming noticeable, the importance for environmental sustainability has been raised. Parabolic trough solar thermal collector system, which is one of the solutions to reduce the carbon dioxide emission, is a mature technology for electricity generation. Malaysia is a tropical country with long daytime, which makes suitable for solar thermal applications with parabolic trough solar thermal collectors. However, the high humidity causes the solar radiation to fluctuate. In order to simulate the solar thermal collectors’ performance at an early design stage of solar thermal power generation systems, fast still accurate transient thermal performance prediction methodis required. Although multiple transient thermal simulation methodologies exist, they are not suited especially at an early design stage where quick but reasonably accurate thermal performance prediction is needed because of their long calculation time.  In this paper, a transient thermal prediction method is developed to predict exit temperature of parabolic trough collectors under fluctuating solar radiation. The method is governed by simple summation operations and requires much less calculating time than the existing numerical methods. If the radiation heat loss at the parabolic trough collector tube surface is small, the working fluid temperature rise may be approximated as proportional to the receiving heat flux. The fluctuating solar radiation is considered as a series of heat flux pulses applied for a short period of time. The time dependent solar collector exit temperature is approximated by superimposing the exit temperature rise caused by each heat flux pulse. To demonstrate the capabilities of the proposed methodology, the solar collector exit temperature for one-day operation is predicted. The predicted solar collector exit temperature captures the trend of a finite element analysis result well. Still, the largest temperature difference is 38.8K and accuracy is not satisfactory. Currently, the accuracy of the proposed method is being improved. At the same time, its capabilities are being expanded. 

scholarly journals Scientific Substantiation of Increase of Technical and Economic Efficiency of Use of Solar Energy

2020 ◽  
pp. 121-130
Author(s):  
L.Hr. Melnyk ◽  
O.I. Matsenko ◽  
V.S. Tereshchenko
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Economic Efficiency ◽  
Economic Feasibility ◽  
The Sun ◽  
Solar Panels ◽  
Axis Orientation ◽  
Fixed Angle ◽  
Advantages And Disadvantages ◽  
Study Results

The article is devoted to finding ways to improve the efficiency of using solar panels. In the mainstream of increasing the economic efficiency of solar stations' operation, methods of reducing the cost of generating electricity based on solar energy are considered. The purpose of the article is to study ways of more efficient use of solar energy and compare the types of installation of photovoltaic converters. The study's main focus is on solar tracking systems, which give the best price/efficiency ratio for solar stations. In particular, the economic feasibility of using a biaxial tracking system for solar panels has been investigated. The advantages and disadvantages of this approach are considered. The energy potential of solar radiation under terrestrial conditions is analyzed. A table of dependences of the angle of motion of the Sun in time for one light day for the conditions of the Sumy region was built. The maximum value of the intensity of solar radiation per year per 1 m2 is calculated. The graph of the average monthly electricity production was built. In the course of the work, an experiment was set up, within the framework of which four options for photoelectric converters' placement were calculated: with automatic guidance to the Sun; inclined type; vertical type; with a fixed angle. It has been established that for the city of Sumy a two-axis orientation system is most effective. According to the results of processing the experimental data, the system with the tracker provides almost 24% more power generation than the stationary installation option (fixed angle) of the photoelectric converter module. Energy organizations and enterprises can use the study results, authorities and other stakeholders in the field of alternative energy.

scholarly journals Thermal Performance on Parabolic Solar trough Collector by using Rgo/Water Nanofluid

2020 ◽  
Vol 8 (6) ◽  
pp. 1406-1411
Keyword(s):  
Solar Radiation ◽  
Flow Rate ◽  
Thermal Performance ◽  
Mass Fraction ◽  
Pure Water ◽  
The Sun ◽  
Parabolic Trough ◽  
Heating Systems ◽  
Solar Water Heating ◽  
Solar Water

The solar water heating systems are one of the popular devices to harness the sun radiation incident on the surface of earth at free of cost. The ASHARE standards 93-86 were followed to study the thermal performance of parabolic solar trough collector using rGO/water nanofluid with the mass fraction of 1% used as a working coolant. To enhance the efficiency regarding temperatures variations, flow rate, and incident solar radiations was examined. These results show that influencing of nanofluid on the collector had more efficient than with pure water owing to solar radiation and flow rate. The efficiency of solar parabolic trough collector has improved with an effect of nanofluid compared to pure water.

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