From above literature review it was observed that high initial cost and lower efficiency are the major drawbacks of using of cylindrical paraboliccollector technology. Thermal performance and conversion efficiency of collectors get reduced due to higher wind speed, dust and harsh environmental conditions. To make concentrating collector technology economically viable, an attempt has made in this work to design a prototype cylindrical parabolic trough collector with top glass cover and fabricated with low cost locally available material. Top glass cover avoids the entry and deposition of dust, soil over reflector and also reduces convective heat losses due to higher wind speed.
Global warming issues and limited availability of conventional fuels leads the world to look for alternative energy sources . The energy from the SUN is unlimited and clean. The Parabolic trough solar collector technology is one of the technique to harness the sun energy . It is well-established commercial level power generation technology. Parabolic trough solar collector has two vital components a linear parabolic mirror and a heat collection element (HCE) . The parabolic mirror focuses the incident rays to an HCE located at its focal line as shown in the Figure. 1. The HCE absorbs the energy of the concentrated rays and transmits it to a heat transfer fluid (HTF) in the form of heat. The absorbed heat is then dissipated in the heat exchanger to generate the steam that is used to run the turbine to generate the electricity .
absorption cycle consists of four stages: generation, condensation, evaporation and absorption with ideally no moving part. The heat input to the absorption system generator is provided by parabolic dish collectors that are coupled to a generator tank. Results and performance of this system and the effects of the refrigeration load inlet temperature on the coefficient of performance, COP of the system are presented.
Figure 3 depicts the variation of dimensionless temperature as a function of dimensionless distance of the receiver tube for three Reynolds numbers. It is observed that tube wall temperature increases along the length up to half-length of the tube, beyond that the temperature decreases. For constant heat flux wall boundary condition, the fluid temperature is expected to increase along the flow direction. Clearly, the wall temperature must increase along the length of the tube However, a small drop in temperature at outmost section due to end losses is appreciable. It is, therefore, inferred that the decrease in wall temperature beyond half-length of the tube is due to misalignment of the receiver tube with the focus of the parabolic concentrator. As far as a parabolic trough collector is concerned a small deviation of receiver tube from the focus will result in significant loss in energy absorbed by the receiver tube. In view of this, the experimental result implies that an adjusting mechanism needs to be incorporated with the existing setup to align the receiver tube exactly with the focus of the paraboliccollector.
Abstract: Now a day’s consumption of hot water is increased because of our modern life style for drinking, cooking, washing, bathing etc. For heating water, we are using non-renewable energy sources which cause damage to the environment. In this present work it is suggested to increase the temperature of water by using solar energy, which is available abundantly at free of cost. The device that increases the water temperature through solar heat energy source is known as ‘PARABOLIC SOLAR TROUGH COLLECTOR’. PTSC is a simple device that collects the solar radiation and focus on to copper pipe which is exactly located at the focal point of trough and their by increases the water temperature which is eco-friendly and economical. The performance of PTSC depends on the amount of rays reflected on to the copper pipe. Any attempt that improves the concentration of sun rays results in improvement of the performance of PTSC. In the present attempt it is proposed to analyze the performance of PSTV associated with magnifying lens which increases the feed water temperature and the effect of PTSC orientation and black coating on PTSC performance is analyzed. From this experiment it is obtained that the paraboliccollector along with the magnifying glasses yields max output temperature and productivity. Orientation of the PTSC is suggested to position in 30 o North towards West direction to obtain maximum productivity. When paraboliccollector along with magnifying lens is placed at 30 ° north towards the West a maximum temperature difference obtained is 28°C by which performance is improved by 42.85% than without magnifying glasses. When paraboliccollector with black coating on the copper pipe is placed at 30 ° north towards west a maximum temperature difference obtained is 17 ° C by which performance is improved by 5.88% than without black coating.
752 | P a g e The area of paraboliccollector is calculated by consideringavailable solar irradiation per unit area and the energy required.Seven coils of copper tube are to be found for better surface areacontact in the cube of phase change material located in thecentre.since 57kg of PCM is required ,so two parabolic pointsolar collectors are used. The small tank is sited next to thecooker for condensation of the wet mixture. A pump is also built-in for the circulation of water and it completes one cycle. Thetemperature of water increases aggressively and it cooks the foodin the cooker. If this system is erected in the universe, we caneasily face the LPG and electrical power demand. By eliminatingthe usage of LPG, we can control the carbon emissions in largequantity.
The case of cylindrical parabolic concentrator /Compound parabolic concentrator fluid temperature up to 400ºC can be achieved. The most common commercially available solar plants use parabolic trough concentrator. A paraboliccollector includes the receiver tube, concentrator and power transmission collector structure. The Receiver is the element of system where solar radiation is absorbed and converted to thermal energy. It include the absorber tube, it’s associated glass cover and insulation at its end .The Thermal Losses from the receiver of a concentrating solar collector significant influence the performance of collector system under high temperature operation.
The paraboliccollector is that type of thermal collector which is bent as parabola. The bent face has polished mirrors or polished aluminium sheet for reflection of heat energy on absorber or receiver pipe placed at focal length of parabola. Source and sink connected to the receiver pipe for working fluid flow. Rate of heat transfer depends on mass flow rate, controlled by valve given at outlet of receiver pipe.
The crisis of conventional energy sources is one of the major problem in India. The solar energy is pollution free and abundently available renewable energy source. Generally the solar energy is used in applications like solar water heater,solar cookers,solar batteries,solar panels etc. But the main limitatation of using solar energy for solar cooking is that cooking is possible only in sunshine hours.So to made availability of solar energy in off sunshine hours is major problem. To overcome this; the storage system is to be developed with storage modification in solar cooker . This paper discussed the solar cooker with storage system. The solar energy is stored in phase change materials as a latent heat storage. The better model that build’s both traditional heat trapping cum concentrator mechanism. It will have two way supply of heat directly from sun during day time for cooking and from the phase change material during night time. Parabolic dish collector is selected because it gives better solar energy with minimum loss. It reviews relevant issues related with solar cooking using latent heat storage that include cooking pot and concentrating paraboliccollector.
Abstract: This paper evaluates the potential of solar concentration technologies—compound paraboliccollector (CPC), linear Fresnel collector (LFC) and parabolic trough collector (PTC)—as an alternative to conventional sources of energy for industrial processes in Latin America, where high levels of solar radiation and isolated areas without energy supply exist. The analysis is addressed from energy, economic and environmental perspective. A specific application for Argentina in which fourteen locations are analyzed is considered. Results show that solar concentration technologies can be an economically and environmentally viable alternative. Levelized cost of energy (LCOE) ranges between 2.5 and 16.9 c€/kWh/m 2 and greenhouse gas
Lippke  has compared the results of his model with the results of real plant conditions for winter and sum- mer seasons to test the accuracy. It is concluded that the model is inadequate to fully match with actual solar field conditions. Valan and Sornakumar  have used a computer simulation program to model the parabolic trough collector with hot water generation system with a well-mixed type storage tank. From the verification of the model with actual generation 6% deviation is obtained. Yadav et al.  have examined, analysed and tested the parabolic trough collector with different type of reflectors. They identified aluminium sheet as cost effective material to use as reflector. In Spain, there are three power plants namely Andasol 1, Andasol 2 and Andasol 3 that are being operated using parabolic trough collector technology with a capacity of 50 MW each. The annual peak efficiency of each plant is 28% and average efficiency is 15%. The plants are operating with thermal stor- age of 7.5 hours using molten salt . Price et al.  have validated their FLAGSOL model based on Parabolic Trough Collector. The projected performance and actual performance of a 30 MW Solar Energy Generation System (SEGS) plant over a full year of operation is 6%. This is developed by KJC Operating Company at Kramer Junction, California. Purohit  et al. evaluate the CSP potential of 2000 GW in north-western India in the available waste land and solar radiation assessment with viability of different technologies with 50 MW ca- pacity of PTC based plant. Similar to our simulation study, earlier workers have also computed for different plants. However, our study is more general and broad based.
The collector system comprises the heliostat field. Each heliostat is made of 2mm thick float glass mirror having high reflectivity. 6 These flat mirrors are cheaper in contrast to the reflectors used in parabolic trough. Care is taken to maintain low iron content in the heliostat material. Since the heliostat field represents the largest single capital investment in a power tower plant, advancements in technology are needed to improve the ability to manufacture, reduce costs, and increase the service life of heliostats. In particular, a lower cost azimuth drive system is needed (i.e., to rotate the heliostat around an axis that is perpendicular to the ground). 6 Light rays reflected from the heliostat are focused upon the receiver to raise the temperature of the HTF. The HTF is made of molten salt which contains 60% NaNO 3 and 40% KNO 3 . The salt
The Evacuated tube collector consists of a number of rows of parallel transparent glass tubes connected to a header pipe and which are used in place of the blackened heat absorbing plate we saw in the previous flat plate collector. These glass tubes are cylindrical in shape. Evacuated tube collectors do not heat the water directly within the tubes. Instead, air is removed or evacuated from the space between the two tubes, forming a vacuum (hence the name evacuated tubes). This vacuum acts as an insulator reducing any heat loss significantly to the surrounding atmosphere either through convection or radiation making the collector much more efficient than the internal insulating that flat plate collectors have to offer. With the assistance of this vacuum, evacuated tube collectors generally produce higher fluid temperatures than their flat plate counterparts so may become very hot in summer.
Stainless steel sheet 2.4m ×1m was chosen as reflecting surface. The collector is designed with simple parabolic equations. From geometrical relations of the parabolic section, equations (1), the cross section for the parabolic trough was traced as shown by Fig 4. The sheet was curved to form a parabolic trough module of 2.4m length which was calculated from equation (4) and 1m aperture width with effective aperture area of 2.4 m 2 .
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 solar collector.This is a device which absorbs the incoming solar radiation, converts it into heat, and transfers this heat to a fluid (usually air, water, or oil) flowing through the collector.
The parabolic trough is the oldest of the modern solar thermal technologies. The first recorded version is that of a Dr. Maier of Aalen and a Mr. Remshalden of Stuttgart, who developed a system based on a parabolic trough collector to generate steam. Their system was followed in 1912–13 by a facility built in Cairo by U.S. inventor Frank Shuman. The plant used tracking solar troughs to generate steam for a steam engine, although the initial plan was for the plant to generate electricity. 1 The project comprised five collectors, each 62 m long and 4 m in width. The steam that the collectors were able to produce was equivalent to a generating capacity of 41 kW.
An efficient parabolic trough solar collector (PTSC) was developed from locally available materials and used for dehydration of apricots. The apricots were cut into two halves and dried after pre-treatment of 1% with sodium benzoate solution. Apricots were dried at temperatures of 40, 50 and 60°C under three different air mass flow rates of 1.57, 2.29 3.56 kg.min -1 at less than 30% humidity Shortest apricots drying time was 16
The prototype of V-trough SWH system was constructed in the Adithya institute of technology campus that is located at Coimbatore with latitude 11.1134° N and longitude of 77.0364° E. In this system, the stationary V-trough collector was designed to concentrate the sunlight onto the absorber in order to effectively convert solar energy into thermal energy. The following describe the details of each component of the prototype V-trough SWH system and how these components were constructed.
Parabolic solar system is a non conventional energy system and in this research work performance of parabolic solar system has been optimized. For this, PAPSC software has been designed and developed to analyse the performance of solar collector with and without considering Sun’s cone angle. Developed PAPSC software reduces human effort and eliminates human error. Various parameters have been calculated to analyse the performance of parabolic solar collector; heat gain rates, inlet/outlet temperatures, inner/outer surface areas of absorber pipe, concentration ratios, absorbed fluxes, overall heat loss coefficients, collector efficiency factors, heat removal factors, maximum useful energy available from solar radiation, inlet exergies, outlet exergies, exergy gain rates and exergy efficiencies have been found at different modes of orientations of PSC and then optimum conditions have been identified. This work can be concluded as; mode IV gives maximum exergy efficiency (61.93%) whereas maximum exergy gain rate (2178.10W) achieves with mode III, exergy efficiency increases when instantanious efficiency decreases but not with instantanious beam radiation, inlet exergy decreases with instantanious beam radiation but not with instantanious efficiency whereas outlet exergy decreases when instantanious efficiency increases but not with instantanious beam radiation. Exergies at inlet and outlet increase with dimensions of parabolic solar collector and also with instantanious efficiency but not with instantanious beam radiation.
In practical observations, around 0.5 m water was able to lift this could be due to the wet steam gets impinged into the balloon due to leakages resulting into the formation of moisture inside the balloon. This ultimately affects the lift of water. Ideally, after the generation of temperature the steam would get generated in the boiler unit. But due to lack of superheated steam the required pressure is not getting developed. For the same purpose the boiling unit needs to be heated which can be achieved by integrating it with a parabolic reflector which could generate continuous heat. The pressure loss is mainly observed due to the pipe which attaches boiler unit and inlet on piston cylinder.