This would prevent over-heating of the circulating fluid, a common problem in many applications of solarcollectors. One of the first studies of heat pipes in solarapplications was carried out by Bienert and Wol. In this case, the evaporator end of a heat pipe was inserted in a flat-platecollector, and the condenser protruded into a water manifold attached to the upper end of the collector. The results of this investigation were neither conclusive nor optimistic. Since then, numerous studies have been carried out, including theoretical analysis and calculation, experimental testing, combined investigation involving theoretical analysis and experimental trials , as well as applications in practice . Most of these studies involved the investigation of the thermal performance of various types of heat-pipe solarcollectors by analytical, numerical or experimental methods with the aim of establishing suitable structures or system layouts, as well as optimum operating conditions for high efficiency.
Solar energy collectors are 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 solarcollector. Of all the solar thermal collectors, the flatplatecollectors though produce lower temperatures, have the advantage of being simpler in design, having lower maintenance and lower cost. To obtain maximum amount of solar energy of minimum cost the flatplatesolar air heaters with thermal storage have been developed. Solar air heater is type of solarcollector which is extensively used in many applications such as residential, industrial and agricultural fields.
In recent years solar energy has been strongly promoted as a viable energy source. One of the simplest and most direct applications of this energy is the conversion of solar radiation into heat. Hence way that the domestic sector can lessen its impact on the environment is by the installation of solarflatplatecollectors for heating water. Although it should be said that some of these collectors have been in service for the last 40-50 years without any real significant changes in their design and Operational principles. A typical flat-platecollector consists of four components (i) absorber plate (ii) tubes fixed to the absorber plate (iii) the transparent cover (iv) the collector box. The collector plates absorb the maximum possible amount of solar irradiance and transfer this heat to the working fluid which is flowing in absorber tube. The fluid used for heat transfer generally flows through a metallic tube, which is connected to the absorber plate. The absorber is usually made of metallic materials such as copper, steel or
Abstract: Solarflatplatecollectors are devices adapted excite solar thermal energy and use it for heating applications like water heating, house heating and totally different industrial applications. Flatplatecollectors [FPCs] are normal for low and medium heating applications. Therefore, statistical and experimental studies were conducted on site in order to improve the thermal efficiency of FPCs.Coolant oil is utilized as fluids are the foremost effective ways in which to improve heat transfer. Comparison of varied heat transfer improvement methods, that cause choosing the foremost effective chance among them. The results of mode parameters just like the thickness and coating of the glass cowl, the thickness and material of the sorbent material plate, the air gap between the sorbent material plate and so the glass cowl, and so the space between risers and so the insulation materials are thought of to spice up the performance of FPCs. The influences of the atmosphere conditions, mass flow, angle and constant on the performance of the collector with clear insulating materials were analyzed.
Abstract: Solarflatplatecollectors nowadays find more applications considering the cost involved with conventional water heating systems using fossil fuels. The performance of these systems can usually be enhanced by varying select important parameters of the system for improved heat transfer ability of the collector. Therefore, this work is aimed at evaluating the effects of nano-Nickel Oxide (NiO) coatings on liquid flatplatecollector for better heat transfer effect. Two flatplatecollectors are designed and fabricated with same operating parameters such as collector area, system size and spacing, pipe diameter and size of collecting tank, etc. The heat transfer effect is simultaneously studied in these two units to observe the effect of nano coating in comparison with black chrome coating.
Abstract :Solarflatcollectors are devices used to trap solar thermal energy and use it for heating applications like water heating, room heating and other industrial applications. Analysis of solarcollector is complex task, due to high number of parameter affecting its performance .This paper presents the study on different techniques that are employed to enhance the efficiency of flatplatecollector .Effect of using enhancement device ,use of propylene glycol, nanofluid, change water flow rate for better capture of radiation and method of heat loss reduction .The problem of flatplatesolar energy collector with water flow is simulated and analysed using computational Fluid-Dynamics. Computational Fluid-Dynamics (CFD) approach has become powerful tool o investigate the heat transfer phenomenon. A lot of work have been made to develop the heat transfer mechanism in a solarcollector.
The conventional energy sources are inadequate to accommodate the demand of energy which increases due to rapid industrialization and population growth. To overcome these problem non-conventional energy resources are used. Solarflatplatecollector is a solar energy collector which is used to absorb solar radiation from sun and employed for heating the fluid flowing through it. Generally it uses circular pipe through which fluid is flow. Flatplatecollector is use to raise the temperature of flowing fluid up to desired temperature that is up to 1000C. This collector absorbs both direct and diffuse solar radiation. Due to this reason it can works effectively on cloudy days. Hence, performance of solarflatplatecollector is increased.
Abstract—This research document presents an experimental study on the effect of the superposition of glass panes on the functioning of a solar thermal collector. Experiments were carried out on an active solar energy demonstration system (ET 200). It consists of a flatplatesolarcollector, water storage tank, a control and command cabinet and a high- power lamp, simulating natural sunlight. Three (03) commercial glass panes of 3mm, 5mm and 8mm thick were used. In the first experiment the collector glass was replaced by the superposition of the two panes of 3 and 5mm thick. In the second experiment the collector glass was replaced by the thickest glass (8mm). The glass of 8mm thick leaves more energy, generated from the halogen lamp, to penetrate inside the collector than the composed glass (3mm+5mm), which leaves less energy reaching the absorber. The glass pane of 8mm thick has an efficiency of about 44% against 40% for the composed glass (3mm+5mm). The glass composed from the superposition of the panes of 3mm and 5mm thick exerts a distinct effect, on the solarcollector, than the simple glass of 8mm thick. So, it is not possible to replace the single pane of 8mm thick by the superposition of the two panes of 3 and 5mm thick.
BAA Yousef et al. , carried out a theoretical study to investigate the effect of mass flow rate, flow channel depth and collector length on the system thermal performance and pressure drop through the collector with and without porous medium. The analysis of the results at the same configuration and parameters shows that the system thermal efficiency increases by 10-12% in double flow mode than single flow due to the increased of heat removal, and increase by 8% after using porous medium in the lower channel as a result of the increase of heat transfer area. At the same time the pressure drop will be increased. All collectors show improved efficiency obtained when the collector operates at relatively high flow rates, and at relatively low collector temperature rise since the collector losses will be less in low temperature difference.
Abstract:In this research work 2-D CPC (Compound Parabolic Concentrator) with flatplate absorber and two parabolic reflectors is first designed and then fabricated for thermal performance analysis. Here the incident rays, after reflection from the reflector, are not focused at a point but are simply collected on a line of absorber surface. Acrylic sheets are provided to reduce the heat loss. Flatplatecollectors have been widely used for application that demand temperature up to 100ºC and large amount of research efforts are already made. For medium temperature range (100- 300ºC) application, concentrating type collectors are suitable. For 2-D CPC, concentration ratio is generally in the range 2 to 10.CPC is generally oriented in E-W direction.The top portion of the reflector does not intercept much radiation, so the CPC is truncated to 2/3 of its full height.Truncation saves a large amount of reflector material with only a little loss in concentration ratio.
Figure 1 and Figure 2 show visualization model of collectors with and with- out baffles as shown as presented by . Figure 1 illustrates airflows patterns in a collector without baffles, it can be observed that there is straight airflow in the aperture of the absorber from the inlet toward outlet which creates many dead zones. This means that there is no enough retention time between air and ab- sorber to allow the effectiveness of heat transfer. On the other hand, Figure 2 shows the formation of a meandering flow of air in the collector with baffles from the inlet to the outlet. In this case, it is clear that the length of air trajectory is more than double that of the length of the collector, thus increasing the heat transfer and effectively reducing dead zones.
A pair of 200 mm × 140 mm absorbers were built . This was a labour-intensive exercise and it became clear that the machining and manual welding time would be impracticable for a larger (0.5 × 0.5 m) panel. The time and cost could however be much reduced in a mass production context using a formed or extruded base plate with con- tinuous, automated welding or using an alternative manufacturing technique, for instance roll-bonding [28,29]. For non-evacuated solarcollectors, micro-channel absorbers could also be produced cheaply using injection-moulded polymers [30,31]: the low material con- ductivity necessitates a micro-channel or ﬂ ooded design instead of a serpentine tube. Polymers were not considered for this project because they are currently unsuitable for high-vacuum, high-temperature use.
ABSTRACT: A Single basin solar still with basin Area (0.9mx0.7m) was design & fabricated with integration of flatplatecollector (0.9mx0.9mx0.3m) to increase the heat transfer rate. Experiments were done with different modifications of solar still and the readings were taken .First reading is taken from still without modification of flatplatecollector .The second setup consists of still with flatplatecollector modified by heat absorbing materials (pebbles, chips, red stone) . The final experimental setup consist of still integrated with flatplatecollector and glass wool. The results indicated that the productivity of the still without modification of flatplatecollector, still with flatplatecollector modified by heat absorbing materials, still integrated with flatplatecollector and glass wool was 36.92 %, 42.68 % and 46.60 %. Also it was found that the productivity of the still was highest with the minimum depth of water. KEYWORDS: FlatPlateCollector, Heat Absorbing Materials, Solar Still,
From extensive review on research literature, it has been observed that influence the performance of a flatplatecollector such as changing the absorber tube, selective coatings, numbers of covers, spacing between covers and absorber plate, working fluid etc. This report highlights the advancements in design configurations and component material investigation to enhance efficiency and performance of flatplatecollector. It has been found that flatplatecollector enhancement widely investigated both analytically and experimentally. Advancement like modify V-groove, dimples type absorber surface, circular and rectangular absorber fins in a tube, pocket type absorber plate, absorber with fins, absorber plate having concavities, sandwich type absorber plate, semi-circular absorber tube, double glazing polymer films, selective coatings, use of Nano-material, packed bed material and fluids provide improvement in flatplatecollector performance lead to increase the solarflatplatecollector application worldwide. The basic idea of all the research is to increase the efficiency of the Flat-PlateSolarCollector and also reducing the heat losses occurring in the particular device. Analysis given in this paper will help to create the best design and operational conditions with the best economic characteristics for solarflatplatecollectors.
solarcollector and the heat pipe solarcollector is investigated theoretically and experimentally, and the optimum ratio of evaporator length and condenser length is also discussed. Hussein [5-6] studied theoretical and experimental investigation of wickless at pipes flatplatesolarcollector and optimum cooling water mass flow rate and number of heat pipes. Thermal behavior of flatplate heat pipe solarcollectors was studied by various researchers [7-12]. Abdul-Jabber  studied the performance of locally made flatplatecollectors used as part of a domestic hot water system. They found the temperature distribution along the flow direction and the thermo siphon mass flow rate. Kulkarni et al.  observed that there exists a minimum as well as a maximum storage volume for a given solar fraction and collector area. Akhtar  studied the computation of glass cover temperatures and obtain the glass cover temperatures. Maatouk knoukhi  studied the theoretical approach of flat plat solarcollector taking into account the absorption and emission within glass cover layer and the thermal behavior and head loss from the solar collator. Elshazly et al  studied the heat transfer by free vertical and inclined elliptical tube. For the elliptical tube a constant heat flux and with different orientation angles has been used. In the present study an elliptical heat pipe solarcollector was designed constructed and investigated theoretically and experimentally under different water mass flow rates and inlet cooling water temperature. Also the effect of ratio of evaporator length to condenser length also discussed.
enhance the performance for polymer solarcollector using a CFD technique. It was highlighted that the buoyancy and gravity effect need to be considered in the momentum equation for inclined solarcollectors. Thermal efficiency increased with the increase in the uniformity of the flow and temperature distribution . Laminar and turbulent flow were considered to predict outlet temperature for a parabolic trough collector. ANSYS FLUENT (version 16.1) was employed with a heat flux boundary condition on the absorber tube. Inlet temperature was in the range of 30.5 to 54 ◦
ABSTRACT: An Innovative design of solar water heater flatplatecollector is developed and tested. The collector is made-up of rectangular aluminium having size 0.97 m X 1.81 m total surface area for heat conduction is 1.9845 m 2 . The absorber is made of Aluminium box with one large surface exposed to sunlight having size 1.94 m x 1.1 m x 0.1 m, glass 4 mm thick toughened to cover the box large open surface, black paint for absorbing solar radiation and insulation layer. Maximum temperature of water obtained at outlet of collector is 73.3 0 C. Also an innovative storage tank is investigated. The storage tank is made up of MS plate, 50 mm puff insulation, outer-cladding cover, inside coating with Fiber Reinforcement plastic and 60%-40% partition for hot and cold water. Due to this FRP coating thermal conductivity of tank material and night heat losses get reduced. In conventional hot water storage tank night temperature losses is found to be 9 0 C while in modified FRP coating tank with partition night temperature losses is found to be 4 0 C.
In one of the earliest experiment of forced convection heat transfer, as described [4,5] in, heated a 0.5 m 2 copper plate mounted vertically and flush with the side of a wind tunnel. Air speed was measured at the center of the tunnel and an analysis of results yielded a correlation for smooth surface as:
Martinopoulos et al. (2010) developed a CFD model of a polymer solarcollector in order to study the performance. The study highlighted that including body and buoyancy force was important for large computational domain. The behaviour of the heat transfer was also investigated in order to enhance the performance for polymer solarcollector using a CFD technique. It was highlighted that the buoyancy and gravity effect need to be considered in the momentum equation for inclined solarcollectors. Thermal efficiency increased with the increase in the uniformity of the flow and temperature distribution . Laminar and turbulent flow were considered to predict outlet temperature for a parabolic trough collector. ANSYS FLUENT (version 16.1) was employed with a heat flux boundary condition on the absorber tube. Inlet temperature was in the range of 30.5 to 54 °C while the maximum increased was 10.5 °C .