Academic literature on the topic 'Solar conical collector'

This study aimed to evaluate a solar water heating system for using on residences, using a solar collector with conical concentrator. The principle of light concentration in a solar collector with conical concentrator is the capture and reflection of solar radiation in the center of a tapered concentrator with internal reflective faces. The area of concentration of solar energy is occupied by a receiver with material of high thermal conductivity, properly isolated by transparent surfaces, to form the greenhouse effect, where the thermal energy is transferred to a working fluid. The characterization of the system was done through field tests to determine the efficiency in the water heating. The tests were performed considering different scenarios, which varied according to the heating system (passive and active with different water flow) and solar tracking (manual adjustment and stationary). The results showed that the scenarios with solar tracking presented an average efficiency of 12.63%, which was more efficient than those presented by the fixed orientation, which was 11.44%. Besides that, it was verified that the active solar heating systems were more efficient than the passive ones.

Heat transfer improvement in solar operated devices is one of the key issues of energy saving and compact designs. Researches in heat transfer have been carried out over the past several decades, culminating in the development of the heat transfer techniques used at present. The use of additives is a technique employed to enhance the heat transfer performance of base fluids. Recently, an innovative material, nanosized particle has been used in suspension in conventional heat transfer fluids that changes the heat transfer characteristic. In this project, an attempt has been made to verify change in heat transfer behavior while using nanofluids. For this purpose, a conical solar collector has been designed, constructed using locally available sheet steel. Polyurethane foam material is used as a insulating liner inside the cone. Thin reflective aluminum sheet is used to focus the solar radiation onto the absorbing surface. The main objective of this paper is to study the heat transfer behavior of Al2O3, Cu2O and ZnO nanofluid and especially Al2O3nanofluid of various concentrations in absorber space of conical solar collector. Experimental study was conducted on different days and the data were recorded. The results obtained show that addition of nanoparticles in the base fluid, improve the heat transfer rate.

Energy consumption has increased withthe population increase, and fossil fuel dependency has risen and causing pollutions. Solar energy is suitableto provide society's thermo-electric needs. Thermal energy storage-based concentrated solar receivers are aimed at store heat energy and transportable to the applications. Acavity receiver with two-phase change materials (PCM) is experimentally investigated using a parabolic dish collector to act as the solar heat battery. The selected PCMs are MgCl2.6H2O and KNO3-NaNO3. PCMs are chosen and placed as perthe temperature zones of the receiver. The outdoor test wasconductedto determine the conical receiver's storage performance using cascaded PCMs. The complete melting of PCM attainsat an average receiver surface temperature of 230°C. The complete melting of the PCM in the receiver took around 30 minutes at average radiation around 700 W/m2, and heat stored is approximately 5000 kJ. The estimated number of cavity receivers to be charged on a sunny day is about 10-15 according to the present design and selected PCMs, for later use

Abstract— The solar energy is the most important type of energy. The parabolic dish solar collector (PDSC) is the best type among other solar collectors because it is always tracking the sun movement. The exergy and the energy performances of a PDS were analyzed experimentally and numerically. The effect of different coil geometries and different mass flow rates of heat transfer fluid (HTF) were investigated. The PDS has parabolic dish and receiver with diameter (1.5) m and (0.2) m respectively. Concentration ratio is 56.25. The parabolic polar dish was supported by a tracking system with two axes. The types of the copper absorber were used which are: (spiral –helical) coil (SHC) and spiral-conical coil (SCC). The results showed that the useful energy and thermal efficiency are varying with solar radiation variation. The useful energy varying between (480-765) W for (SHC), the thermal efficiency varying between (35.2-39.8) % for (SHC). Exergy efficiency varying between (6.9 –8.6) %. It was shown that the higher values of useful energy for (spiral – helical) absorber was 0.1L/min flow rate. REFERENCES 1. T. Taumoefolau , K. Lovegrove ," An Experimental Study of Natural Convection Heat Loss from a Solar Concentrator Cavity Receiver at Varying Orientation. ", Australian National University,, Canberra ACT 0200 AUSTRALIA.2002 2. S. PAITOONSURIKARN and K. LOVEGROVE," On the Study of Convection Loss from Open Cavity Receivers in Solar Paraboloidal Dish Applications ", Australian National University Canberra ACT 0200, AUSTRALIA, pp 154,155,2003 3. Soteris A. Kalogirou*,"Solar thermal collectors and applications", Higher Technical Institute, Progress in Energy and Combustion Science 30 (2004) 231–295, pp237, 240, 241, 2004 4. M. Prakash, S.B. Kedare, J.K. Nayak," Investigations on heat losses from a solar cavity receiver", Department of Energy Science and Engineering, Indian Institute of Technology Bombay, Mumbai 400076, India,2008. 5. Shiva Gorjian1, Barat Ghobadian1, Teymour Tavakkoli Hashjin1, and Ahmad Banak ,"Thermal performance of a Point-focus Solar Steam Generating System ", 21st Annual International Conference on Mechanical Engineering-ISME201 7-9 May, 2013, School of Mechanical Eng., K.N.Toosi University, Tehran, Iran ,1ISME2013-1195,2013 6. Kailash Karunakaran1 Hyacinth J Kennady2 ,"Thermal Analysis of Parabolic Dish Snow Melting Device " ,International Journal for Research in Technological Studies| Vol. 1, Issue 3, February 2014 | ISSN (online): 2348-1439,2014 7. Charles-Alexis Asselineau, Ehsan Abbasi, John Pye "Open cavity receiver geometry influence on radiative losses" Australian National University (ANU), Canberra, ACT 0200 Australia. Solar2014: The 52nd Annual Conference of the Australian Solar Council 2014 8. Vahid Madadi, Touraj Tavakoli and Amir Rahimi First and second thermodynamic law analyses applied to a solar dish collector" DOI 10.1515/jnet-2014-0023 | J. Non-Equilib. Thermodyn. 2014; 39 (4):183–197 9. Yaseen. H. Mahmood , Mayadah K h. Ghaffar " Design of Solar dish concentration by using MATLAB program and Calculation of geometrical concentration parameters and heat transfer" , University of Tikrit , Tikrit , Iraq, Tikrit Journal of Pure Science 20 (4) ISSN: 1813 – 1662, 2015. 10. Vanita Thakkar, Ankush Doshi, Akshaykumar Rana "Performance Analysis Methodology for Parabolic Dish Solar Concentrators for Process Heating Using Thermic Fluid IOSR", Journal of Mechanical and Civil Engineering (IOSR-JMCE) eISSN: 2278-1684,p-ISSN: 2320-334X, Volume 12, Issue 1 Ver. II (Jan- Feb. 2015), PP 101-114 11. Saša R. pavlovi, Evangelos A. bellos, Velimir P. Stefanovi, Christos Tzivanidis and Zoran M. Stamenkovi "Design, Simulation ,and Optimiztion Of A Solar Dish Collector with spiral coil absorber ", , Nis, Serbia, thermal SCIENCE, Vol. 20, No. 4, pp. 1387-1397 1387,2016 12. Flávia V. Barbosa, João L. Afonso, Filipe B. Rodrigues, and José C. F. Teixeir," Development of a solar concentrator with tracking system", University of Minho,Guimarães, 4800-058, Portugal2016 13. O. López, A. Arenas, and A. Baños"Convective Heat Loss Analysis of a Cavity Receiver for a Solar Concentrator" International Conference on Renewable Energies and Power Quality (ICREPQ’17)Malaga (Spain), 4th to 6th April, 2017 ,ISSN 2172-038 X, No.15 April 2017 RE&PQJ, Vol.1, No.15, April 2017 14. D.R.Rajendran,E.GanapathySundaram,P.Jawahar "Experimental Studies on the Thermal Performance of a Parabolic Dish Solar Receiver with the Heat Transfer Fluids Sic water Nano Fluid and Water", Journal of Thermal Science Vol.26, 15. Muhammad Shoaib, Muhammad , Jameel Kabbir Ali ,Muhammad Usman1, Abdul Hannan " Analysis of thermal performance of parabolic dish collectors having different reflective" ,NFC institute of engineering &fertilizer research ,2018 . 16. Sasa PAVLOVIC, Evangelos BELLOS, Velimir STEFANOVIC ,Christos TZIVANIDIS " EXPERIMENTAL AND NUMERICAL INVESTIGATION OF A SOLAR DISH COLLECTOR WITH SPIRAL ABSORBER" A CTA TECHNICA CORVINIENSIS – Bulletin of Engineering Tome XI [2018] .

Concentrated solar collectors have high efficiency as compared to flat plate and evacuated tube solar collectors. Cavity receivers are mainly used on the parabolic dish concentrators and tower type concentrator systems. The heat transfer surfaces of cavity receiver are composed by coiled metal tube. Heat transfer fluid flows in the internal spaces of coiled metal tube, and the external surfaces would absorb the highly concentrated solar energy. This paper explains the thermal performance of parabolic dish concentrator system with hetero-conical cavity receiver. The experimental analysis was done during the month of April 2014 on clear sunny days at Chennai [Latitude: 13.08oN, Longitude: 80.27oE] to study its thermal performance.

Radiative energy transfer through a truncated cone window with a back-plane reflector is considered. This geometry is proposed for a high-pressure direct-radiation (volumetric) central solar receiver for use in combined-cycle electricity generation. The transmission and loss characteristics, computed by ray-tracing, are parameterized by the angle of incident radiation relative to the cone axis. The overall performance of the window is an integral of the angle-dependent transmission data, weighted by the actual distribution of input radiation, over all incidence angles. This parameterization provides insight and assists in tailoring of the window geometry to different solar collection methods. Results are presented for several window geometries. Overall window performance is presented for a dish-type distribution of input radiation.

Made available in DSpace on 2017-07-10T15:14:39Z (GMT). No. of bitstreams: 1 DissertacaoFerandoToniazzo.pdf: 4063087 bytes, checksum: 32e14216dde0f5bd7619d1a08ef14e8c (MD5) Previous issue date: 2016-04-04
Fundação Araucária
This work aims to optimize a solar water heating system for use on small farms. The solar heating system to be optimized is based on a collector with conical concentrator. The principle of concentration of light in a solar funnel collector comes down in abstraction and reflection of solar radiation to central hub with a tapered inner faces reflective. The solar energy concentration area is occupied by a receiver with high thermal conductivity material, suitably isolated by transparent surfaces for forming the greenhouse, where thermal energy is transferred to a working fluid. The characterization of the system shall take place with test runs the field to relate the proposed changes as a function of system efficiency. The method is summarized in data sampling in different scenarios, which vary according to the heating system (passive and active) and solar tracking (manual and stationary). Preliminary results show the optimization of the absorber geometry and the interaction of light in a conical concentrator. The results demonstrate that the scenarios with solar tracker have higher efficiency than with fixed orientation and solar heating systems operated actively are more efficient than passive systems
Este trabalho teve por objetivo otimizar um sistema de aquecimento solar de água para uso em pequenas propriedades rurais. O sistema de aquecimento solar otimizado é baseado em um coletor com concentrador cônico. O princípio de concentração de luz em um coletor solar com concentrador cônico resume-se na captação e reflexão da radiação solar ao centro de um concentrador afunilado com faces internas refletivas. A área de concentração de energia solar é ocupada por um receptor com material de alta condutibilidade térmica, devidamente isolado por superfícies transparentes para formação do efeito estufa, onde a energia térmica é transferida para um fluido de trabalho. A caracterização do sistema se efetuou com execuções de testes a campo para relacionar as mudanças propostas em função da eficiência do sistema. A metodologia constituiu-se de amostragens de dados em diferentes cenários, os quais variaram de acordo com o sistema de aquecimento (passivo e ativo) e rastreamento solar (manual e estacionário). Os resultados demonstraram que os cenários com seguidor solar apresentaram maior eficiência do que os com orientação fixa e os sistemas de aquecimento solar operados de forma ativa foram mais eficientes do que os sistemas passivos.

Here we describe a new type of point-focus solar collector for CSP called “track and tilt”. It bridges the gap between dish and heliostat arrays collectors, having the high optical efficiency of a dish but with larger aperture (> 1000 m2) focused to a tower mounted receiver in fixed gravity orientation. It is well matched to the next generation of high efficiency cavity receivers transferring heat to a storage medium at temperatures exceeding 700C. The collector uses silvered glass reflectors mounted on a rotating, rigid structure in the form of a 120 degree conical arc. In operation, this large structure rotates in azimuth on a track around the central receiver tower, keeping the gravity load on the structure constant. The central receiver is rotated about a vertical axis so as to face the reflector arc. The reflectors are concave, all with the same focal length, and are individually tilted to follow solar elevation to focus sunlight onto the tower-mounted receiver. A detailed optical model made of a collector with 40 m focal length has 1,450 m2 total reflector area, and delivers on average 1.2MW of sunlight to the receiver, (under 1000 W/m2 DNI and allowing for reflector and small geometric losses). The collector forms an only slightly aberrated image of the sun at the receiver, showing a concentration of 2000x averaged over the receiver entrance with spillage < 2%. The overall annual averaged efficiency, defined as (total sunlight energy delivered to the receiver entrance)/(direct normal irradiance × total reflector area) is >80%. This calculation includes 90% reflectivity of the mirrors. To avoid the high mass and cost of a structure which must withstand 85 mph winds, our unique arc support structure takes the form of four lightly built panels which are lowered to the ground in high wind and for maintenance. Cables from the central tower are used to lower and raise the panels into operating position where they are locked together. The top section of the tower carrying the cable mechanism and the receiver rotate on a bearing in synchronization with the track mounted reflector assembly. The small scale of the collector unit means that a first prototype of the radical new architecture can be built and tested at relatively modest cost. Higher power systems with multiple collectors and receivers might be built either with individual storage and turbines, such as sCO2, or with heat transfer to a common storage and power generation facility (as in trough systems). Continual improvements of the collector should be affordable, as system iteration costs are low.

In this paper an experimental thermal analysis made to a conical receiver attached to a solar parabolloid dish concentrator is presented, the purpose of this study is to know if it fulfills the requirements as far as quality and amount of energy demanded by a generator of a solar thermal cooling system (Solar-Branched-GAX Cycle). The analyzed system consists of a conical receiver of 19 cm of diameter by 20 cm of height, which was mounted to a focal length of 80 cm in a communications conventional antenna of 190 cm diameter, prepared with a reflecting coat. The concentrator was mounted in a multipurpose proving stand of solar collectors, with a solar tracking system in two axes. The analysis was carried out by evaluating experimentally three cases, which consisted of: A) receiver smooth, B) Receiver smooth with glass cover and C) Receiver with fins in the inner tail cone. According to the obtained results it can be concluded that the system of parabolloid disc concentrator using a conical receiver with fins is a very interesting option to be used as a generator of a solar thermal refrigeration system, since steam for a volumetric flow of 0.480 l/min can be generated.