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Solar energy collectors are special kind of heat exchangers that transform solar radiation energy to internal energy of the transport medium. The solar collector is the major component of any solar system. There are basically two types of solar collectors: non-concentrating or stationary and concentrating. The latter require some kind of tracking m...
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Citations
... These collectors capture both direct beam radiation (straight line rays reach the earth) and diffuse beam radiation (scattered rays), hence a solar tracking system is not necessary. In these types of collectors, the area of the collector is equal to the receiver area resulting in the concentration ratio (CR) being equal to 1 (Kalogirou 2008). ...
... The range of temperature can be achieved up to 200 °C in ETC (Kalogirou 2008. The performance of ETCs can be enhanced (for achieving the higher temperature range) by providing selective surface coating (Kalogirou and Lloyd 1992). ...
... Concentrators or absorbers can be any shape such as cylindrical, parabolic, continuous or segmented, whereas receivers can be convex, concave, fat, cylindrical or covered with glazing, etc. The concentration ratio (CR) can be more than 1 to 1500 (Kalogirou 2008). The higher CR means the exit temperature from the collector is higher. ...
... These collectors capture both direct beam radiation (straight line rays reach the earth) and diffuse beam radiation (scattered rays), hence a solar tracking system is not necessary. In these types of collectors, the area of the collector is equal to the receiver area resulting in the concentration ratio (CR) being equal to 1 (Kalogirou 2008). ...
... The range of temperature can be achieved up to 200 °C in ETC (Kalogirou 2008. The performance of ETCs can be enhanced (for achieving the higher temperature range) by providing selective surface coating (Kalogirou and Lloyd 1992). ...
... Concentrators or absorbers can be any shape such as cylindrical, parabolic, continuous or segmented, whereas receivers can be convex, concave, fat, cylindrical or covered with glazing, etc. The concentration ratio (CR) can be more than 1 to 1500 (Kalogirou 2008). The higher CR means the exit temperature from the collector is higher. ...
... These collectors capture both direct beam radiation (straight line rays reach the earth) and diffuse beam radiation (scattered rays), hence a solar tracking system is not necessary. In these types of collectors, the area of the collector is equal to the receiver area resulting in the concentration ratio (CR) being equal to 1 (Kalogirou 2008). ...
... The range of temperature can be achieved up to 200 °C in ETC (Kalogirou 2008, Sharma et al. 2017. The performance of ETCs can be enhanced (for achieving the higher temperature range) by providing selective surface coating (Kalogirou and Lloyd 1992). ...
... Concentrators or absorbers can be any shape such as cylindrical, parabolic, continuous or segmented, whereas receivers can be convex, concave, flat, cylindrical or covered with glazing, etc. The concentration ratio (CR) can be more than 1 to 1500 (Kalogirou 2008). The higher CR means the exit temperature from the collector is higher. ...
... Solar collectors can be classified as stationary or concentrating [9]. Concentrating solar collectors generally have concave reflecting surfaces to intercept and focus the sun's beam radiation to a smaller receiving area, thereby increasing radiation flux, while stationary collectors have the same area for intercepting and absorbing solar radiation [10]. Solar collectors are distinguished by their motion in three types; stationary, single-axis tracking, and two-axis tracking. ...
... where is the receiver's surface diffusion coefficient (between 0 and 1), is the Boltzmann constant (5.6703x10 -8 w/m 2 K 4 ), Trec_r is the receiver's hot surface temperature (K), Trec_p is the receiver's peripheral surface temperature (K), Tamb is the ambient temperature (K), Ar is the receiver's hot surface area (m 2 ), and Ap is the receiver's peripheral surface area (m 2 ) (Fig.8). The heat losses due to wind flow (convection) can be calculated by conv t conv Q hA T (9) where h is the convection heat transfer coefficient (w/m 2 K), At is the total area of the receiver (m 2 ) given by t r p A A A (10) 10.45 10 , (11) and ∆ is the difference between the average temperature of the water at the inlet and outlet and the ambient temperature (K), and v is wind speed (m/sec) [29]. Equation (11) is valid for wind speeds up to 20 m/sec [30]. ...
This study presents a novel approach to fabricating a low-cost solar parabolic dish concentrator with one-meter-long glass/silver mirrors on the reflecting surface. The concentrator's parabola curve is made of four layers of fiberglass needle felt and polyester resin. The para-bolic dish surface is mirrored vertically with 2 mm thickness glass/silver mirrors with a width of 5 cm and a length of one meter attached with silicone glue. The system is assembled and tested at the Sharif University of Technology in Tehran, Iran. Energy and exergy efficiencies are calculated using cylindrical water heater receiver data. These data are used to calculate the receiver's absorbed energy and losses. Test results show that the major energy loss is due to con-vection. The average energy efficiency and the maximum exergy efficiency of the concentrator are 57% and 67%, respectively. The maximum power absorbed by the water is 1656.8 W at midday, and the maximum temperature observed on the receiver is 540 C. Finally, a discussion is held to propose ideas to improve the fabrication process of the designed parabolic dish concentrator. This type of fabrication is suitable for regular thermal applications. However, several deficiencies are detected, and a few solutions are suggested. Mirror edges and flexibility are two of the parabolic dish's major defects.
... Among all unconventional energy sources, solar energy is considered as the ample and a viable option for thermal energy applications [6]. In currently available solar thermal electric technology, parabolic trough technology is considered as the most important technology [7]. There are nine large commercial scale solar power plants, the first plant has been running in the California Mojave Desert since 1984. ...
... The fixed receiver/absorber of standard cylindrical parabolic trough solar collector is positioned in the middle of the trough at or slightly above the radius across the edges of the reflector. The shape of the trough (rim angle) is designed for determining the focal point, and also the position of the receiver [7,27,28]. The reflector surface is usually made up of polished aluminum, aluminized plastic, silvered glass, or stainless steel. ...
Nowadays petroleum-based energy sources rule the largest energy consuming domestic sector across worldwide. The energy used for cooking is the most important in the energy consuming sector, and its demand is continuously increasing day by day. Solar energy used for cooking is one of the prominent solutions for meeting the energy demands. However, its large-scale distribution and propagation still remain limited. Among the various solar cooking technologies are exist globally, limited technologies were used. This paper discusses the recent developments of a solar cooking technologies. The detailed review on solar cooking technologies provides an outline on solar cookers developed. Solar parabolic cooker is working on the principle of solar thermal heating system. Solar thermal systems generate heat energy from sun light. Flat-plate solar thermal collectors are used to heat air or a water for space and water heating or drying agricultural products because of producing low temperature (27 °C to 60 °C). The parabolic solar cooker with sun tracking system helps to reduce the need for frequent manual tracking and standing of sun and it increase the performance of the solar cooker with constant heating process. Sun tracking with the help of sensors and microcontroller. Parabolic reflector helps to concentrate the light into a single point on the cooker and the light energy converted into a heat energy. Due to this heating process, food is cooked in the pot.
... The design of photoreactors based on solar collectors has already been extensively reviewed, 67 operating from the observation that UV light is expensive in terms of lamp manufacturing and electricity consumption. The Compound Parabolic Concentrator (CPC) photoreactor is very popular, 68,69 and it is generally composed of a number of pyrex tubes connected in series and irradiated by concentrated solar light transmitted by a parabolic round mirror, which permits a concentration of sunlight equivalent to 25 or 70 suns, depending on mirror area and aperture diameter. 70 There is also one recirculation pump and one tank. ...
The research in the heterogeneous photocatalysis to remove different types of pollutants in liquid phase has notably increased in the last years. The main objectives of the research dealing with photocatalysis were: (i) to shift the photoactivity of catalysts in the visible light range or to increase the degradation rate; (ii) the use of the artificial light sources (low pressure lamp, high pressure lamp, LEDs, and optical fibers) and solar light; (iii) photocatalysts recovering and deactivation; (iv) photoreactor configuration; (v) photodegradation of contaminants of emerging concern; and (vi) verification of induced effects from the photocatalytic treatment, such as the induction of bacterial resistance. Here, one of the main problems in the practical application of photocatalysis, which is the photoreactors scale‐up, is addressed with the use of mathematical modeling. In this perspective, this mini review reports a literature exam of the main parameters that are important to take into account for the design and the development of photoreactors for wastewater treatment, and through the use of computational fluid dynamics models (CFD). © 2020 Society of Chemical Industry
... The solar collectors are one of the most common issues in the literature review, commonly associated with LCC analysis, mainly because of the contribution of these components to the whole cost and their influence on the energy efficiency of the solar energy solutions. Kalogirou (2007) studied the patents of solar collectors and categorised them into two types, mainly the non-concentrating or stationary and the concentrating. The author also studies the tracking mechanism that allows the collector to follow the apparent movement of the sun with precise accuracy. ...
This review focus on LCC Assessment (LCCA) and the adoption of this methodology for the economic pillar evaluation of the Sustainability Life Cycle in the Solar Energy sector. Research showed the effectiveness of this methodology as the main component for assessing sustainability in the economic domain, and the relationship with the primary methods of environmental and social areas. The energy industry has been responsible for a significant number of publications, and the use of LCCA for different scale solar energy solutions as vehicles, houses, buildings, highways, rural properties and power plants indicates the usefulness of this methodology. In the large-scale solar energy solutions, for Solar Photo Voltaic (SPV) and Concentrated Solar Power (CSP), the use of LCCA can upraise the advantages for choosing or integrating both solutions. Also clarifying the feasibility of their critical ancillary solutions, named Electrical Energy Storages (EES) and the Thermal Energy Storages (TES). In minor scale solar energy solutions where the crescent technological evolution of SPV Cells has resulted in higher energy efficiency rates, the use of the LCCA can demonstrate the sensitive reduction on the Levelled Cost of Energy (LCOE), reflecting on the feasibility of solutions as the Zero Energy Buildings (ZEB). These facts allied to the crescent number of studies and publications shows that LCCA is a promising field of studies and a powerful tool to achieve a most complete and reliable Life Cycle Sustainability Assessment of solar energy technologies and also the solar energy implementation projects, mainly in the design phase.
... With the objective to obtain a quantitative measure of the thermal degradation of EPS at four different depths from the surface, 0, 30, 60 and 90 nm, this work presents a study about its thermal degradation at the light of the carbonization, dehydrogenation and oxidation that occurs at 120°C. This temperature can be obtained in solar collectors designed to degrade EPS and other solid wastes [11]. The study was done by X-ray photoelectron spectroscopy (XPS) evaluating the energetic distribution of C1s orbitals before and after the heating. ...
Carbonization, oxidation and hydrogenation in expanded polystyrene (EPS) resulted from its thermal degradation at 120 °C are studied in this work using X-ray photoelectron spectroscopy. This hardly biodegradable polymer accumulates large quantities of solid wastes because it is commonly used in disposable dishes and containers. The objective of the work was to obtain a quantitative measure of its thermal degradation at four different depths from the surface, 0, 30, 60 and 90 nm based on the evolution of its chemical states as a function of the heating time. At least ten carbon chemical states were identified, five belonged to the EPS structure, and the others appeared due to the thermal degradation in the form of multiple chemical bonds. The results indicated that carbonization and dehydrogenation were the main degradation mechanisms of the thermal treatment. During the first 7 h of heating, carbonization increased 6.6%, hydrogenation decreased 6.2% and oxidation decreased 2.5%. The surface had more oxidation and behaved differently from the interior of the material. As most atoms in EPS are C, it was considered that the difference in carbonization percentages could represent the degradation percentage of the material.
... Ericsson built eight systems having parabolic troughs by using either water or air as the working medium [171]. A complete history of these and other early applications of solar energy is given in [172] and is not repeated here. ...
... A comprehensive review of the various types of collectors currently available is presented in [172] and may not be repeated here. The interested author is advised to refer to this publication where details of the various collectors available are described, together with their possible applications, including desalination. ...
... Also, more details of these systems can be found in numerous publications [174,175]. The rest of this section deals with collectors and renewable energy systems not covered in [172]. ...
... Various types of photovoltaics are now on the market; however, their manufacturing cost is high, and research and development studies are still under way to improve these energy collectors [2][3][4]. A solar collector is a type of heat exchanger that uses the incident solar radiation energy directly as heat [5]. Solar energy collectors can be categorized as nonconcentrating and concentrating. ...
... It consists of two identical parabolic curves, AD and BC, and it achieves the highest possible concentration. Because multiple internal reflections are used, any radiation that passes through the aperture within the acceptance angle reaches the absorber [5]. The coordinate system equation of the CPC is as follows [14]. ...
... If the concentrator is oriented along the north-south direction, a sun tracking system must be operated continuously. If it is oriented along the east-west direction, with or without a slight seasonal adjustment in the tilt angle, it can gather solar radiation effectively within its acceptance angle [5]. The proposed concentrator is oriented with its line axis along the east-west direction, and its aperture is tilted southward, as shown in Figure 4. To determine the position of the solar concentrator, the solar altitude a s must be specified with respect to the winter and summer solstices (December 21 and June 21, respectively), because the sun travels between these points over the course of a year. ...
A nontracking, nonimaging solar concentrator with a low-heat-loss configuration was proposed, and its optical and thermal performance was investigated. The reflector has a compound parabolic and involute shape so that the absorber is heated as uniformly as possible. To eliminate heat loss by conduction and convection, the mirror and absorber are enclosed in an evacuated glass tube. The concentrator presented here was simulated for the location of Sendai, Japan, and its acceptance angle was estimated as 23.44°. A ray-tracing model was developed to evaluate its optical and thermal performance. The average optical efficiency was evaluated by a 2-D ray-tracing model, and a value of 72.7% was obtained. A thermal analysis of the absorber was conducted to evaluate the temperature uniformity. The results indicate that the temperature distribution of the absorber can be considered uniform. The thermal efficiency of the proposed solar concentrator was calculated as a function of the incidence angle and absorber temperature. With a concentration ratio of 2.51, the concentrator, even at an absorber temperature of 373 K, operates with an average efficiency of 47.8%, although the absorber was assumed to have a gray surface. The concentrator's thermal efficiency was compared with that of other solar collectors, and found to be higher than that of conventional solar collectors. © 2015 American Institute of Chemical Engineers Environ Prog, 2015
