WorldWideScience

Sample records for plate air collectors

  1. Low cost bare-plate solar air collector

    Science.gov (United States)

    Maag, W. L.; Wenzler, C. J.; Rom, F. E.; Vanarsdale, D. R.

    1980-09-01

    A low cost, bare plate solar collector for preheating ambient air was developed. This type of solar heating system would be applicable for preheating ventilation air for public buildings or other commercial and industrial ventilation requirements. Two prototype collectors were designed, fabricated and installed into an instrumented test system. Tests were conducted for a period of five months. Results of the tests showed consistent operating efficiencies of 60 percent or greater with air preheat temperature uses up to 20 degrees for one of the prototypes. The economic analyses indicated that this type of solar system was economically viable. For the materials of construction and the type of fabrication and installation perceived, costs for the bare plate solar collector are attainable. Applications for preheating ventilation air for schools were evaluated and judged to be economically viable.

  2. Comparison of Thermal Performances between Low Porosity Perforate Plate and Flat Plate Solar Air Collector

    Science.gov (United States)

    Chan, Hoy-Yen; Vinson, A. A.; Baljit, S. S. S.; Ruslan, M. H.

    2018-04-01

    Flat plate solar air collector is the most common collector design, which is relatively simpler to fabricate and lower cost. In the present study, perforated plate solar collector was developed to improve the system thermal performance. A glazed perforated plate of 6mm holes diameter with square geometry was designed and installed as the absorber of the collector. The influences of solar radiation intensity and mass flow rate on the thermal performance were investigated. The perforated collector was compared with the flat plate solar collector under the same operating conditions. The highest values of thermal efficiency in this study for the perforated plate (PP) and the flat plate (FP) solar collectors were 59% and 36% respectively, at solar radiation intensity of 846 Wm-2 and mass flow rate of 0.02 kgs-1. Furthermore, PP collector gave better thermal performance compared to FP collector; and compared to previous studies, the present perforated design was compatible with the flat plate with double pass designs.

  3. Flat plate collector. Solarflachkollektor

    Energy Technology Data Exchange (ETDEWEB)

    Raab, N

    1979-03-29

    The invention refers to a flat solar collector with an absorber plate, which is arranged on a support and is covered by a transparent window, between which and the plate there is an air space. The previously known structures of this type had the disadvantage that the thermal expansion of the enclosed air caused considerable difficulties. The purpose of the invention is therefore to create a collector, which can be used on the modular system, retains its properties and is safe in spite of the great temperature variations. According to the invention this problem is solved by providing a compensating space in the collector, which is separated by a diaphragm from the airspace between the plate and the covering window. The airspace therefore remains sealed against the atmosphere, so that no dirt, corrosion of the inside and no condensation can reduce the efficiency of the collector. A rise in pressure due to an increase in temperature is immediately reduced by expansion of the diaphragm, which enters the compensation space. In order to increase the pressure in the airspace above the plate for increases in temperature, the compensation space is connected to the atmosphere. The diaphragm can be mirrored on the side towards the absorber, which makes the diaphragm into an insulating element, as it reflects radiated heat from the absorber.

  4. Daily efficiency of flat-plate solar air collectors for grain drying

    Energy Technology Data Exchange (ETDEWEB)

    Ting, K.C.; Shove, G.C.

    1983-01-01

    Single cover flat-plate solar collectors incorporated into walls and roofs of farm buildings have been used to heat ambient air for low temperature grain drying systems. Large surface area and high airflow rate are common features of these collectors. The drying period may range from several days to several weeks. Therefore, a knowledge of the variations of the collectors' daily efficiencies with respect to their design parameters would be helpful in applying solar collectors to grain drying. The objective of this study was to develop a simpler means of direct calculation of a collector's daily efficiency based on its design parameters. Many factors, such as configuration of the collector, airflow rate, weather conditions, etc. will affect the performance of solar collectors. A large number of varied conditions need to be tested in order to investigate the effect of different parameters on the collector performance. To facilitate this investigation, a computer simulation model developed by Ting was used to calculate the daily efficiencies of collectors under different operating conditions. The computer model was verified by Morrison's experimental data. Based on the simulation results, a functional relationship was developed between the daily efficiencies of collectors and their design parameters.

  5. Energy and Exergy Analysis of Dual Channel Solar Air Collector with Different Absorber Plates Geometry

    Directory of Open Access Journals (Sweden)

    Najim A. Jassim

    2018-04-01

    Full Text Available Flat-plate collector considers most common types of collectors, for ease of manufacturing and low price compared with other collectors. The main aim of the present work is to increase the efficiency of the collector, which can be achieved by improving the heat transfer and minimize heat loss experimentally. Five types of solar air collectors have been tested, which conventional channel with a smooth absorber plate (model I, dual channel with a smooth absorber plate (model II, dual channel with perforating “V” corrugated absorber plate (model III, dual channel with internal attached wire mesh (model Ⅳ, and dual channel with absorber sheet of transparent honeycomb, (model Ⅴ. The dual channel collector used for increasing heat transfer area and heat removal factor to improve thermal performance. The outdoor test was conducted during the period December (2016 to February (2017 at different mass flow rates 0.0217 kg/s, 0.0271 kg/s and 0.0325 kg/s. The experiments were carried out from 8:30 AM to 3:00 PM for clear days. Experimental results show that the average thermal efficiency was (72.2 % for model (III, (40.2 % for model (I, (51.6 % for model (II, (65.1 % for model (Ⅳ and (59.7 % for model (Ⅴ. At the last part of the study, the exergy analyses were derived for both collectors. The results of this part showed that the conventional channel model (I is having largest irreversibility, and the dual channel collector model (III is having a greatest exergetic efficiency.

  6. Entransy analysis on the thermal performance of flat plate solar air collectors

    Institute of Scientific and Technical Information of China (English)

    Jie Deng; Xudong Yang; Yupeng Xu; Ming Yang

    2017-01-01

    Based on the thermo-electric analogy (the so-called thermal entransy analysis), the unified airside convective heat transfer coefficient for different sorts of flat plate solar air collectors (FPSACs) is identified in terms of colector aperture area. In addition, the colector thermodynamic characteristic matching coefficient is defined to depict the matching property of collector thermal performance between the collector airside heat transfer and the total heat losses. It is found that the airside convective heat transfer coefficient can be experimentally determined by collector thermal performance test method to compare the airside thermal performances of FPSACs with different types of airflow structures. Moreover, the smaler the colector thermodynamic characteristic matching coefficient is, the better the thermodynamic perfect degree of a FPSAC is. The minimum limit value of the collector thermodynamic matching coefficient is close to zero but it can not vanish in practical engineering. Parameter sensitivity analysis on the total entransy dissipation and the entransy increment of a general FPSAC is also undertaken. The results indicate that the effective way of decreasing total entransy dissipation and enhancing the useful entransy increment is improving the efficiency intercept of the FPSAC. This is equivalent to the cognition result of thermal analysis. However, the evaluation indices identified by the thermal entransy analysis can not be extracted by singular thermal analysis.

  7. Air bubble-induced detachment of polystyrene particles with different sizes from collector surfaces in a parallel plate flow chamber

    NARCIS (Netherlands)

    Gomez-Suarez, C; van der Mei, HC; Busscher, HJ

    2001-01-01

    Particle size was found to be an important factor in air bubble-induced detachment of colloidal particles from collector surfaces in a parallel plate flow chamber and generally polystyrene particles with a diameter of 806 nm detached less than particles with a diameter of 1400 nm. Particle

  8. Connectable solar air collectors

    Energy Technology Data Exchange (ETDEWEB)

    Oestergaard Jensen, S.; Bosanac, M.

    2002-02-01

    The project has proved that it is possible to manufacture solar air collector panels, which in an easy way can be connected into large collector arrays with integrated ducting without loss of efficiency. The developed connectable solar air collectors are based on the use of matrix absorbers in the form of perforated metal sheets. Three interconnected solar air collectors of the above type - each with an transparent area of approx. 3 m{sup 2} - was tested and compared with parallel tests on two single solar air collectors also with a transparent area of approx. 3 m{sup 2} One of the single solar air collectors has an identical absorber as the connectable solar air collectors while the absorber of the other single solar air collector was a fibre cloth. The efficiency of the three solar air collectors proved to be almost identical in the investigated range of mass flow rates and temperature differences. The solar air collectors further proved to be very efficient - as efficient as the second most efficient solar air collectors tested in the IEA task 19 project Solar Air Systems. Some problems remain although to be solved: the pressure drop across especially the connectable solar air collectors is too high - mainly across the inlets of the solar air collectors. It should, however, be possible to considerably reduce the pressure losses with a more aerodynamic design of the inlet and outlet of the solar air collectors; The connectable solar air collectors are easy connectable but the air tightness of the connections in the present form is not good enough. As leakage leads to lower efficiencies focus should be put on making the connections more air tight without loosing the easiness in connecting the solar air collectors. As a spin off of the project a simple and easy way to determine the efficiency of solar, air collectors for pre-heating of fresh air has been validated. The simple method of determining the efficiency has with success been compared with an advance method

  9. Drying of fruits and vegetables using a flat plate solar collector with convective air flow

    International Nuclear Information System (INIS)

    Mansoor, K.K.; Hanif, M.

    2011-01-01

    This paper presents the analysis of drying of different fruits and vegetables dried by a flat plate solar collector developed at the Department of Agricultural Mechanization, Khyber PukhtunKhwa Agricultural University Peshawar, Pakistan. A small flat plate solar collector is designed and tested for its maximum performance in terms of efficiency with different convective flow rates. The collector assembly is divided into two parts. The flat plate solar collector and the drying chamber. The materials used for flat plate solar collector are wood, steel sheet, Insulation materials, and glass sheet as covering material. The insulation box (0.9 x 1.8 x 0.3 meter) is made up of wood of popular and deodar, to be fully isolated with the help of polystyrene. The absorber is black painted v-corrugated steel sheet. Collector has a tilt angle of 34 deg. (Equivalent to the latitude of Peshawar). The covering material is (0.9 x 1.8 meter) and 5 mm thick glass sheet placed at the top of the wooden box. The collector is supported and tilted with the help of a frame made up of iron angled arms. While the drying chamber is a (1 X 0.5 x 0.3 meter) wooden box connected to the outlet duct of the collector with the help of polyvinylchloride pipe. Experiments were conducted different fruits and vegetables and different parameters like moisture lost by the products in each hour, drying rate at each hour of drying, humidity and temperature of the drying chamber. It was observed that the products such as bitter guard and onion were dried in 10 to 2 hours up to moisture content less then 8%. These two product lost 8% to 10% moisture during each hour of drying. While grapes and Green chili are dried in 24 to 25 hours up to moisture content less then 8%. These two products lost 4% to 5% moisture in each hour of drying. The drying rate of all the products dried was very much consistent. It was observed that onion and bitter guard showed a good drying rate of 0.03[g(H/sub 2/O)/g(d.m).cm/ 2 hr] to

  10. Air/liquid collectors

    DEFF Research Database (Denmark)

    Jensen, Søren Østergaard; Olesen, Ole; Kristiansen, Finn Harken

    1997-01-01

    this kind of collectors. The modified simulation program has been used for the determination of the surplus in performance which solar heating systems with this type of solar collectors for combined preheating of ventilation air and domestic hot water will have. The simulation program and the efficiency......This report determine efficiency equations for combined air/liquid solar collectors by measurements on to different air/liquid collectors. Equations which contain all relevant informations on the solar collectors. A simulation program (Kviksol) has been modified in order to be able to handle...

  11. Numerical analysis and experimental validation of heat transfer characteristic for flat-plate solar air collector

    International Nuclear Information System (INIS)

    Hung, Tzu-Chen; Huang, Tsung-Jie; Lee, Duen-Sheng; Lin, Chih-Hung; Pei, Bau-Shei; Li, Zeng-Yao

    2017-01-01

    Highlights: • Various types of solar air collectors are discussed. • CFD has been used to validate the characteristics of heat transfer. • Solar Ray Tracing has been successfully used for thermal radiation flux. - Abstract: This study combines both concepts of solar ventilation technology and solar air collector. This is a quite innovative and potential facility to effectively use thermal energy and reduce the accumulation of heat in the indoor space simultaneously. The purpose of this study is to create a prototype and implement the experiments. Computational fluid dynamics (CFD) approach is employed to validate the characteristics of the flow and heat transfer. For the accuracy of numerical predictions, the method of Solar Ray Tracing was used for thermal radiation flux as boundary condition on the wall. The local heat transfer correlation was investigated to predict surrounding wind speed upon device cover. Three sorts of glasses and several aspect ratios of flow channels have been compared to conclude the optimal configuration. In addition, four important factors, such as the stagnant layer thickness, emissivity on the illustrated surface, mass flow rate and the height of the device, are also considered and discussed in detail. The result showed that the optimal design is dominated by the combination of an aspect ratio of 50 mm:10 mm, and appropriate mass flow rate to the height of the device. The present work on thermal energy collection can assist us in designing a powerful solar air collector in some potential applications.

  12. Detachment of polystyrene particles from collector surfaces by surface tension forces induced by air-bubble passage through a parallel plate flow chamber

    NARCIS (Netherlands)

    Wit, PJ; vanderMei, HC; Busscher, HJ

    1997-01-01

    By allowing an air-bubble to pass through a parallel plate flow chamber with negatively charged, colloidal polystyrene particles adhering to the bottom collector plate of the chamber, the detachment of adhering particles stimulated by surface tension forces induced by the passage of a liquid-air

  13. Detachment of colloidal particles from collector surfaces with different electrostatic charge and hydrophobicity by attachment to air bubbles in a parallel plate flow chamber

    NARCIS (Netherlands)

    Suarez, CG; van der Mei, HC; Busscher, HJ

    1999-01-01

    The detachment of polystyrene particles adhering to collector surfaces with different electrostatic charge and hydrophobicity by attachment to a passing air bubble has been studied in a parallel plate flow chamber. Particle detachment decreased linearly with increasing air bubble velocity and

  14. Air bubble-induced detachment of positively and negatively charged polystyrene particles from collector surfaces in a parallel-plate flow chamber

    NARCIS (Netherlands)

    Gomez-Suarez, C; Van der Mei, HC; Busscher, HJ

    2000-01-01

    Electrostatic interactions between colloidal particles and collector surfaces were found tcr be important in particle detachment as induced by the passage of air bubbles in a parallel-plate Row chamber. Electrostatic interactions between adhering particles and passing air bubbles, however, a-ere

  15. Studies of flat-plate solar air collectors with absorber plates made of amorphous silicon photovoltaic modules; Amorphous taiyo denchi module wo shunetsuban to shita heibangata kukishiki shunetsuki no kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Sato, K; Ito, S; Miura, N [Kanagawa Institute of Technology, Kanagawa (Japan)

    1996-10-27

    A light/heat hybrid air type heat collector has been developed in which heat is collected by solar cell panels. In Type 1 heat collector provided with a glass cover, two modules are connected in series and placed under a glass cover to serve as a heat collecting plate, each module built of a steel plate and two thin-film amorphous solar cells bonded to the steel plate. Air runs under the heat collecting plate. Type 2 heat collector is a Type 1 heat collector minus the glass cover. Air is taken in by a fan, runs in a vinyl chloride tube, and then through the heat collector where it is heated by the sun, and goes out at the exit. Heat collecting performance was subjected to theoretical analysis. This heat collector approximated in point of heat collection a model using a board painted black, which means that the new type functions effectively as an air-type heat collector. Operating as a photovoltaic power generator, the covered type generated approximately 20% less than the uncovered type under 800W/m{sup 2} insolation conditions. Type 1 has been in service for five months, and Type 2 for 2 months. At present, both are free of troubles such as deformation and the amorphous solar cell modules have deteriorated but a little. 4 refs., 9 figs.

  16. THERMAL PERFORMANCE OF FLAT PLATE SOLAR COLLECTOR

    Directory of Open Access Journals (Sweden)

    TABET I.

    2017-06-01

    Full Text Available In this paper, a theoretical and experimental studyof flat platesolar water collector with reflectors.A mathematical model based on energy balance equations saw the thermal behavior of the collector is investigated. The experimental test was made at the unit research applies in renewable energy (URAER located in southern Algeria.An increase of 23% for solar radiation incident on the collector surface with the addition of the planers reflectors in the day of May, this increase causes an improvement of the performance of the collector,the fluid temperature increases with an average of 5%. Thetests conducted on the flat plate solar water collector in open circuit enabled the determination of thermal performance of the collector by estimating the daily output The thermal efficiency of the collector ranges from 1% -63% during the day, a mean value of 36%obtained.

  17. Energy Analysis of Solar Collector With perforated Absorber Plate

    Directory of Open Access Journals (Sweden)

    Ammar A. Farhan

    2017-09-01

    Full Text Available The thermal performance of three solar collectors with 3, 6 mm and without perforation absorber plate was assessed experimentally. The experimental tests were implemented in Baghdad during the January and February 2017. Five values of airflow rates range between 0.01 – 0.1 m3/s were used through the test with a constant airflow rate during the test day. The variation of the following parameters air temperature difference, useful energy, absorber plate temperature, and collector efficiency was recorded every 15 minutes. The experimental data reports that the increases the number of absorber plate perforations with a small diameter is more efficient rather than increasing the hole diameter of the absorber plate with decreasing the perforation numbers. Maximum air temperature difference throughout the solar collector with 3, 6 mm perforations and without perforations are 17, 15, and 12 oC, respectively. Also, it can be concluded that the energy gained from the solar collector with 3 mm perforation absorber plate is 28.2 % more than the energy gained from solar collector without holes per day for 0.1 m3/s airflow rate. The maximum values of the thermal performance curves are 0.67, 0.64, and 0.56 for the solar collector with 3, 6 mm, and without perforations, respectively.

  18. Bioinspired plate-based fog collectors.

    Science.gov (United States)

    Heng, Xin; Luo, Cheng

    2014-09-24

    In a recent work, we explored the feeding mechanism of a shorebird to transport liquid drops by repeatedly opening and closing its beak. In this work, we apply the corresponding results to develop a new artificial fog collector. The collector includes two nonparallel plates. It has three advantages in comparison with existing artificial collectors: (i) easy fabrication, (ii) simple design to scale up, and (iii) active transport of condensed water drops. Two collectors have been built. A small one with dimensions of 4.2 × 2.1 × 0.05 cm(3) (length × width × thickness) was first built and tested to examine (i) the time evolution of condensed drop sizes and (ii) the collection processes and efficiencies on the glass, SiO2, and SU-8 plates. Under similar experimental conditions, the amount of water collected per unit area on the small collector is about 9.0, 4.7, and 3.7 times, respectively, as much as the ones reported for beetles, grasses, and metal wires, and the total amount of water collected is around 33, 18, and 15 times. On the basis of the understanding gained from the tests on the small collector, a large collector with dimensions of 26 × 10 × 0.2 cm(3) was further built and tested, which was capable of collecting 15.8 mL of water during a period of 36 min. The amount of water collected, when it is scaled from 36 to 120 min, is about 878, 479, or 405 times more than what was collected by individual beetles, grasses, or metal wires.

  19. Thermal performances of vertical hybrid PV/T air collector

    Science.gov (United States)

    Tabet, I.; Touafek, K.; Bellel, N.; Khelifa, A.

    2016-11-01

    In this work, numerical analyses and the experimental validation of the thermal behavior of a vertical photovoltaic thermal air collector are investigated. The thermal model is developed using the energy balance equations of the PV/T air collector. Experimental tests are conducted to validate our mathematical model. The tests are performed in the southern Algerian region (Ghardaïa) under clear sky conditions. The prototype of the PV/T air collector is vertically erected and south oriented. The absorber upper plate temperature, glass cover temperature, air temperature in the inlet and outlet of the collector, ambient temperature, wind speed, and solar radiation are measured. The efficiency of the collector increases with increase in mass flow of air, but the increase in mass flow of air reduces the temperature of the system. The increase in efficiency of the PV/T air collector is due to the increase in the number of fins added. In the experiments, the air temperature difference between the inlet and the outlet of the PV/T air collector reaches 10 ° C on November 21, 2014, the interval time is between 10:00 and 14:00, and the temperature of the upper plate reaches 45 ° C at noon. The mathematical model describing the dynamic behavior of the typical PV/T air collector is evaluated by calculating the root mean square error and mean absolute percentage error. A good agreement between the experiment and the simulation results is obtained.

  20. COMPARATIVE FIELD EXPERIMENTAL INVESTIGATIONS OF DIFFERENT FLAT PLATE SOLAR COLLECTORS

    Directory of Open Access Journals (Sweden)

    Guangming Chen

    2015-12-01

    Full Text Available Full-scale traditional metal solar collectors and solar collector specimens fabricated from polymeric materials were investigated in the present study. A polymeric collector is 67.8% lighter than a traditional metal solar collector, and a metal solar collector with transparent plastic covering is 40.3% lighter than a traditional metal solar collector. Honeycomb multichannel plates made from polycarbonate were chosen to create a polymeric solar collector. A test rig for the natural circulation of the working fluid in a solar collector was built for a comparative experimental investigation of various solar collectors operating at ambient conditions. It was shown experimentally that the efficiency of a polymeric collector is 8–15% lower than the efficiency of a traditional collector.

  1. Recent advances in flat plate photovoltaic/thermal (PV/T) solar collectors

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, Adnan; Othman, Mohd Yusof; Ruslan, Mohd Hafidz; Mat, Sohif; Sopian, Kamaruzzaman [Solar Energy Research Institute Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2011-01-15

    Flat plate photovoltaic/thermal (PV/T) solar collector produces both thermal energy and electricity simultaneously. This paper presents the state-of-the-art on flat plate PV/T collector classification, design and performance evaluation of water, air and combination of water and/or air based. This review also covers the future development of flat plate PV/T solar collector on building integrated photovoltaic (BIPV) and building integrated photovoltaic/thermal (BIPVT) applications. Different designs feature and performance of flat plate PV/T solar collectors have been compared and discussed. Future research and development (R and D) works have been elaborated. The tube and sheet design is the simplest and easiest to be manufactured, even though, the efficiency is 2% lower compared to other types of collectors such as, channel, free flow and two-absorber. It is clear from the review that for both air and water based PV/T solar collectors, the important key factors that influenced the efficiency of the system are the area where the collector covered, the number of passes and the gap between the absorber collector and solar cells. From the literature review, it is obvious that the flat plate PV/T solar collector is an alternative promising system for low-energy applications in residential, industrial and commercial buildings. Other possible areas for the future works of BIPVT are also mentioned. (author)

  2. Efficiencies of flat plate solar collectors at different flow rates

    DEFF Research Database (Denmark)

    Chen, Ziqian; Furbo, Simon; Perers, Bengt

    2012-01-01

    Two flat plate solar collectors for solar heating plants from Arcon Solvarme A/S are tested in a laboratory test facility for solar collectors at Technical University of Denmark (DTU). The collectors are designed in the same way. However, one collector is equipped with an ETFE foil between...... the absorber and the cover glass and the other is without ETFE foil. The efficiencies for the collectors are tested at different flow rates. On the basis of the measured efficiencies, the efficiencies for the collectors as functions of flow rate are obtained. The calculated efficiencies are in good agreement...

  3. Development of a selective thin film and of a hermetically sealed flat plate solar collector with gas filling

    Science.gov (United States)

    Zernial, W.

    1982-12-01

    The industrial productibility of a selective absorbing thin film was investigated on the basis of reactive cathodic sputtering of Ni. On substrates of 1.8 sq m of Al, Cu, steel and stainless steel, solar absorption values up to 97% were achieved at emissivities of 5 to 10%. A prototype flat plate collector for high temperatures with two covers and hermetical sealing was developed. The technical data of the collector were measured, dependent on the selectivity of the absorber, gas fillings of dry air, argon or SF6 and the geometry and were compared with those of an evacuated flat plate collector. A hermetical sealed double flat plate collector for low temperatures was developed which has the advantage of lower no load temperatures and higher energy gain for heating swimming pool water compared with a conventional flat plate collector. The insolation values on collectors were measured and were used for a calculation of the energy gains of different collector types.

  4. An investigation on the performance characteristics of solar flat plate collector with different selective surface coatings

    Energy Technology Data Exchange (ETDEWEB)

    Madhukeshwara, N. [Department of Mechanical Engineering, B.I.E.T, Davanagere, Karnataka (India); Prakash, E.S. [Department of Studies in Mechanical Engineering, U.B.D.T.C.E, Davanagere, Karnataka (India)

    2012-07-01

    In the present work, investigations are made to study performance characteristics of solar flat plate collector with different selective surface coatings. Flat plate collector is one of the important solar energy trapping device which uses air or water as working fluid. Of the many solar collector concepts presently being developed, the relative simple flat plate solar collector has found the widest application so far. Its characteristics are known, and compared with other collector types, it is the easiest and least expensive to fabricate, install, and maintain. Moreover, it is capable of using both the diffuse and the direct beam solar radiation. For residential and commercial use, flat plate collectors can produce heat at sufficiently high temperatures to heat swimming pools, domestic hot water, and buildings; they also can operate a cooling unit, particularly if the incident sunlight is increased by the use of reflector. Temperatures up to 70 C are easily attained by flat plate collectors. With very careful engineering using special surfaces, reflectors to increase the incident radiation and heat resistant materials, higher operating temperatures are feasible.

  5. Performance of evaporator-collector and air collector in solar assisted heat pump dryer

    International Nuclear Information System (INIS)

    Hawlader, M.N.A.; Rahman, S.M.A.; Jahangeer, K.A.

    2008-01-01

    A solar assisted heat pump dryer has been designed, fabricated and tested. This paper presents the performance of the evaporator-collector and the air collector when operated under the same meteorological conditions. ASHRAE standard procedure for collector testing has been followed. The evaporator-collector of the heat pump is acting directly as the solar collector, and the temperature of the refrigerant at the inlet to the evaporator-collector always remained below the ambient temperature. Because of the rejection of sensible and latent heats of air at the dehumidifier, the temperature at the inlet to the air collector is lower than that of the ambient air. Hence, the thermal efficiency of the air collector also increases due to a reduction of losses from the collector. The efficiencies of the evaporator-collector and the air collector were found to vary between 0.8-0.86 and 0.7-0.75, respectively, when operated under the meteorological conditions of Singapore

  6. Flat-plate solar collector - installation package

    Science.gov (United States)

    1978-01-01

    Package includes installation, operation and maintenance manual for collector, analysis of safety hazards, special handling instructions, materials list, installation drawings, and warranty and certification statement. Manual includes instructions for roof preparation and for preparing collector for installation. Several pages are devoted to major and minor repairs.

  7. High Performance Flat Plate Solar Thermal Collector Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Rockenbaugh, Caleb [National Renewable Energy Lab. (NREL), Golden, CO (United States); Dean, Jesse [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lovullo, David [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lisell, Lars [National Renewable Energy Lab. (NREL), Golden, CO (United States); Barker, Greg [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hanckock, Ed [National Renewable Energy Lab. (NREL), Golden, CO (United States); Norton, Paul [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-09-01

    This report was prepared for the General Services Administration by the National Renewable Energy Laboratory. The Honeycomb Solar Thermal Collector (HSTC) is a flat plate solar thermal collector that shows promising high efficiencies over a wide range of climate zones. The technical objectives of this study are to: 1) verify collector performance, 2) compare that performance to other market-available collectors, 3) verify overheat protection, and 4) analyze the economic performance of the HSTC both at the demonstration sites and across a matrix of climate zones and utility markets.

  8. Finite element analysis of a solar collector plate using two plate geometries

    Directory of Open Access Journals (Sweden)

    Diego Manuel Medina Carril

    2016-09-01

    Full Text Available The thermal behavior of an absorber plate in a solar collector is investigated using finite element analysis. The thermal behavior and efficiency of two absorber plate geometries are studied, using a typical solar collector with a rectangular profile as reference, and a proposed absorber plate with curved geometry. An analysis of the most important parameters involved in the design of the absorber plate was carried out, indicating that the curved geometry of the absorber plate yields an average efficiency ~25% higher than the conventional rectangular geometry. The results suggest that a curved profile made of materials such as aluminum with thermal conductivity higher than 200W/m°C, plate thickness of the order of 2-3mm and with a large density of tubes per unit area of the collector´s plate greatly benefits the thermal efficiency of the solar collector.

  9. Movable air solar collector and its efficiency

    International Nuclear Information System (INIS)

    Lauva, A.; Aboltinš, A.; Palabinskis, J.; Karpova Sadigova, N.

    2008-01-01

    Implementing the guidelines of the Latvian National Programme for Energy in the field of alternative energy, intensive research shall be carried on regarding the use of solar energy, as it can be successfully used not only for the purposes of water heating and production of electrical energy, but also for air warming. The amount of heat necessary for the drying of rough forage and grain drying by active aeration in June, July and August can be obtained using solar radiation. The Latvian Guidelines for the Energy Development 2006-2016 state that the solar radiance in Latvia is of quite low intensity. The total amount of solar energy is 1109 kWh m -2 per year. The period of usage of the solar thermal energy is beginning from the last decade of April, when the intensity of radiation is 120 kWh m -2 , until the first decade of September. Within this period (approximately 1800 hours), it is possible to use the solar thermal energy by placing solar collectors. The usage of solar collectors for in drying of agricultural production is topical from the viewpoint of decreasing the consumption of energy used for the drying, as electrical energy and fossil energy resources become more expensive and tend to run out. In the processes that concern drying of agricultural production, efficiently enough solar radiation energy can be used. Due to this reason researching continues and expands in the field of usage of solar energy for the processes of drying and heating. The efficiency factor of the existing solar collectors is not high, but they are of simple design and cheep for production and exploitation. By improving the design of the solar collectors and choosing modern materials that absorb the solar radiation energy, it is possible the decrease the efficiency factor of solar collectors and decrease the production costs. In the scientific laboratory of grain drying and storage of Latvia University of Agriculture, a pilot device movable folding solar collector pilot device

  10. Efficiency improvement of flat plate solar collector using reflector

    Directory of Open Access Journals (Sweden)

    Himangshu Bhowmik

    2017-11-01

    Full Text Available Solar collectors are the main components of a solar heating system. The collectors collect the sun’s energy, transform this radiation into heat, and then transfer this heat into a fluid, water or air, which has many household or industrial applications. This paper introduces a new technology to improve the performance of the solar thermal collectors. The solar reflector used here with the solar collector to increase the reflectivity of the collector. Thus, the reflector concentrates both direct and diffuse radiation of the sun toward the collector. To maximize the intensity of incident radiation, the reflector was allowed to change its angle with daytime. The radiations coming from the sun’s energy were converted into heat, and then this heat was transferred to the collector fluid, water. A prototype of a solar water heating system was constructed and obtained the improvement of the collector efficiency around 10% by using the reflector. Thus, the present solar water heating systems having the best thermal performance compared to the available systems.

  11. Application of solar flat plate collector in automobile industry

    Energy Technology Data Exchange (ETDEWEB)

    Wawge, P. [Peenya Alloys Pvt. Ltd., Parvati, Pune (India)

    2004-07-01

    In any industry, heating, cooling and compressed air the costliest part, which affects the production cost of any product. There are three types of indirect heat requirement or the requirement of heat can be divided in the three main categories. (1) low temp. 40 - 60 Deg. (2) Medium temp. 80 - 150 deg. (3) High Temp applications - above 150. Solar Flat Collectors have been proven for the use of solar energy for medium temp. application in hotels, boiler feed water preheating, dairy for pasteurization and some other indirect heating applications. There is another neglected area of application of Solar Flat Plate collector is heat treatment for powder coating plants where heat requirement is bet 50 Deg C - 70 Deg C. In any automobile industry the aesthetic or look of the vehicle place a very important role as far as the sale is concern (after the mechanical performance). The aesthetic means the body and colour of the vehicle. To get a long lasting good quality color, the powder coating procedure plays a major role. Before powder coating there is requirement of different chemical treatment for the removal of rust, grease and other cleaning of the specific sheet metal body parts. The time duration and chemical composition is depends on the selection of body material. A proven method of a chemical treatment is seven / eight tank process. The common system of heating chemicals is by way of electrical heaters, by diesel or other fuel fired boilers. This increases the cost of heat treatment process due the high cost of electricity (for industries rate of electricity is 1.5 to 2 times than the domestic rate) or oils. This can be replaced by Solar water heating system which can efficiently generate the temp of liquid upto 85 Deg C. (orig.)

  12. Standardized performance tests of collectors of solar thermal energy - A flat-plate copper collector with parallel mylar striping

    Science.gov (United States)

    Johnson, S. M.

    1976-01-01

    Basic test results are reported for a flat plate solar collector whose performance was determined in a solar simulator. The collector was tested over ranges of inlet temperatures, fluxes and one coolant flow rate. Collector efficiency is correlated in terms of inlet temperature and flux level.

  13. Optimization of the functional domain of flat plate collectors

    Science.gov (United States)

    Ritoux, G.; Irigaray, J.-L.

    1981-12-01

    The variations of the extracted heat flux as function of the temperature of the heat transfer fluid in black and selective surface solar collectors are examined. The heat flux is calculated based on the difference of the initial to the stage of thermal equilibrium of the fluid. A nonlinear system of equations is developed and solved by a fast, iterative method to obtain the equilibrium temperatures. It is found that more flux can be extracted from the solar heat by a collector with only one glass cover than with more than one cover. The captured flux is proportional to the coefficient of transmission of the glass coverings, to the coefficient of absorption of the collector, and to the incident flux. Black painted surfaces were more absorbent than selective surfaces, and highest collection efficiencies were displayed by low temperature collectors. Charts of effective uses of the respective types of collectors for heating swimming pools, hot water, home heat, and for refrigeration and air-conditioning are provided.

  14. Annual measured and simulated thermal performance analysis of a hybrid solar district heating plant with flat plate collectors and parabolic trough collectors in series

    DEFF Research Database (Denmark)

    Tian, Zhiyong; Perers, Bengt; Furbo, Simon

    2017-01-01

    Flat plate collectors have relatively low efficiency at the typical supply temperatures of district heating networks (70–95 °C). Parabolic trough collectors retain their high efficiency at these temperatures. To maximize the advantages of flat plate collectors and parabolic trough collectors in l...... for this type of hybrid solar district heating plants with flat plate collectors and parabolic trough collectors in the Nordic region, but also introduce a novel design concept of solar district heating plants to other high solar radiation areas....... in large solar heating plants for a district heating network, a hybrid solar collector field with 5960 m2 flat plate collectors and 4039 m2 parabolic trough collectors in series was constructed in Taars, Denmark. The design principle is that the flat plate collectors preheat the return water from...

  15. Simple air collectors for preheating fresh air

    NARCIS (Netherlands)

    Hensen, J.L.M.; Wit, de M.H.; Ouden, den C.

    1984-01-01

    In dwellings with mechanical ventilation systems the fresh air can easily be preheated by means of simple solar air systems. These can be an integral part of the building facade or roof and the costs are expected to be low. By means of computer experiments a large number of systems were evaluated.

  16. Numerical characterisation of one-step and three-step solar air heating collectors used for cocoa bean solar drying.

    Science.gov (United States)

    Orbegoso, Elder Mendoza; Saavedra, Rafael; Marcelo, Daniel; La Madrid, Raúl

    2017-12-01

    In the northern coastal and jungle areas of Peru, cocoa beans are dried using artisan methods, such as direct exposure to sunlight. This traditional process is time intensive, leading to a reduction in productivity and, therefore, delays in delivery times. The present study was intended to numerically characterise the thermal behaviour of three configurations of solar air heating collectors in order to determine which demonstrated the best thermal performance under several controlled operating conditions. For this purpose, a computational fluid dynamics model was developed to describe the simultaneous convective and radiative heat transfer phenomena under several operation conditions. The constructed computational fluid dynamics model was firstly validated through comparison with the data measurements of a one-step solar air heating collector. We then simulated two further three-step solar air heating collectors in order to identify which demonstrated the best thermal performance in terms of outlet air temperature and thermal efficiency. The numerical results show that under the same solar irradiation area of exposition and operating conditions, the three-step solar air heating collector with the collector plate mounted between the second and third channels was 67% more thermally efficient compared to the one-step solar air heating collector. This is because the air exposition with the surface of the collector plate for the three-step solar air heating collector former device was twice than the one-step solar air heating collector. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Irreversibility analysis of non isothermal flat plate solar collectors for air heating with a dimensionless model; Analisis de las irreversibilidades en colectores solares de placas planas no isotermicos para calentamiento de aire utilizando un modelo adimensional

    Energy Technology Data Exchange (ETDEWEB)

    Bracamonte-Baran, Johane Hans; Baritto-Loreto, Miguel Leonardo [Universidad Central de Venezuela (Venezuela)]. E-mails: johanehb@gmail.com; johane.bracamonte@ucv.ve; miguel.baritto@ucv.ve

    2013-04-15

    The dimensionless model developed and validated by Baritto and Bracamonte (2012) for the thermal behavior of flat plate solar collector without glass cover is improved by adding the entropy balance equation in a dimensionless form. The model is solved for a wide range of aspect ratios and mass flow numbers. A parametric study is developed and the distribution of internal irreversibilities along the collector is analyzed. The influence of the design parameters on the entropy generation by fluid friction and heat transfer is analyzed and it is found that for certain combinations of these parameters optimal thermodynamic operation can be achieved. [Spanish] En el presente trabajo, el modelo adimensional desarrollado y validado por Baritto y Bracamonte (2012) para describir el comportamiento termico de colectores solares de placas planas sin cubierta transparente, se complementa con la ecuacion adimensional de balance de entropia para un elemento diferencial de colector solar. El modelo se resuelve para un amplio rango de valores de relaciones de aspecto y numero de flujo de masa. A partir de los resultados del modelo se desarrolla un analisis detallado de la influencia de estos parametros sobre la distribucion de irreversibilidades internas a lo largo del colector. Adicionalmente se estudia la influencia de estos parametros sobre los numeros de generacion de entropia por friccion viscosa, por transferencia de calor y total. Se encuentra que existen combinaciones de los parametros antes mencionados, para los cuales, la operacion del colector es termodinamicamente optima para numeros de flujo de masa elevados.

  18. Advances in design of air-heating collectors

    CSIR Research Space (South Africa)

    Johannsen, A

    1982-11-01

    Full Text Available Principles of the operation of air-heating collectors are discussed. The fundamental differences between the design principles of air-heating as opposed to water-heating collectors are highlighted. The main requirement is the transfer of heat from...

  19. A solar air collector with integrated latent heat thermal storage

    Directory of Open Access Journals (Sweden)

    Klimes Lubomir

    2012-04-01

    Full Text Available Simulations of the behaviour of a solar air collector with integrated latent heat thermal storage were performed. The model of the collector was created with the use of coupling between TRNSYS 17 and MATLAB. Latent heat storage (Phase Change Material - PCM was integrated with the solar absorber. The model of the latent heat storage absorber was created in MATLAB and the model of the solar air collector itself was created in TRNSYS with the use of TYPE 56. The model of the latent heat storage absorber allows specification of the PCM properties as well as other parameters. The simulated air collector was the front and back pass collector with the absorber in the middle of the air cavity. Two variants were considered for comparison; the light-weight absorber made of sheet metal and the heat-storage absorber with the PCM. Simulations were performed for the climatic conditions of the Czech Republic (using TMY weather data.

  20. Performance Study of Photovoltaic-Thermal (Pv/T) Solar Collector with ·-Grooved Absorber Plate

    International Nuclear Information System (INIS)

    Mohd Yusof Othman; Hafidz Ruslan; Kamaruzzaman Sopian; Jin, G.L.

    2009-01-01

    A hybrid photovoltaic-thermal solar collector has been designed, built and its performance has been studied. The advantage of the collector is that it can generate electricity and heat simultaneously. Photovoltaic module SHARP NE-80E2EA with maximum output power of 80 W was used to generate electricity. The module also acts as heat absorber of the collector. Single pass ·-groove collector made of aluminium sheet with 0.7 mm thickness has been used to collect heat generated. Study was conducted under a designed halogen lamps solar simulator with intensities set at 386 ± 8 Wm -2 and 817 ± 8 Wm -2 . The speed of air passing through the collector was set between (69.6 ± 2.2) x 10 -4 kg/s to (695.8 ± 2.2) x 10 -4 kg/s. The objective of the study is to compare the performance of PV/T collector with and without ·-groove absorber. The study found that the PV/T collector with ·-groove absorber plate has higher efficiency than the PV/T without ·-groove absorber. The electrical and thermal efficiencies are also increased when radiation intensity and speed of air increase. (author)

  1. Investigation of a hybrid PVT air collector system

    Science.gov (United States)

    Haddad, S.; Touafek, K.; Mordjaoui, M.; Khelifa, A.; Tabet, I.

    2017-02-01

    The photovoltaic thermal hybrid (PVT) collectors, which simultaneously produce electricity and heat, are an alternative to photovoltaic modules and thermal collectors installed separately. Indeed, the heat extracted from the solar cell is used to heat water or air, thereby cooling the cell, and thus increasing its energy efficiency. This paper deals with a hybrid PVT air collector in which a new design has been proposed and tested. Its principle is based on the return of the preheating air to a second heating. The air thus passes twice under the solar cells before being evacuated to the outside of the collector (for space heating). The system is modular and expandable to cover large spaces to be heated. The experimental results of this novel design are presented and discussed under both normal and forced circulation. This technique of air return shows favorable results in terms of the quality of the heated air and electric power generation.

  2. Standarized performance tests of collectors of solar thermal energy: A steel flat-plate collector with two transparent covers and a proprietary coating

    Science.gov (United States)

    1976-01-01

    Basic test results of a flat-plate solar collector whose performance was determined in the NASA-Lewis solar simulator are given. The collector was tested over ranges of inlet temperature and flux level.

  3. Analysis and validation of a quasi-dynamic model for a solar collector field with flat plate collectors and parabolic trough collectors in series for district heating

    DEFF Research Database (Denmark)

    Tian, Zhiyong; Perers, Bengt; Furbo, Simon

    2018-01-01

    performance of the hybrid solar district heating plants is also presented. The measured and simulated results show that the integration of parabolic trough collectors in solar district heating plants can guarantee that the system produces hot water with relatively constant outlet temperature. The daily energy......A quasi-dynamic TRNSYS simulation model for a solar collector field with flat plate collectors and parabolic trough collectors in series was described and validated. A simplified method was implemented in TRNSYS in order to carry out long-term energy production analyses of the whole solar heating...... plant. The advantages of the model include faster computation with fewer resources, flexibility of different collector types in solar heating plant configuration and satisfactory accuracy in both dynamic and long-term analyses. In situ measurements were taken from a pilot solar heating plant with 5960 m...

  4. Interaction of regulation and innovation: Solar air heating collectors

    OpenAIRE

    Kramer, K.

    2012-01-01

    Solar Air Heating Collectors have still a very small share of 0.8% of the nominal installed capacity in the solar heating and cooling market (151.7 GWth) [1]. Although constituting a niche market, the potential of those kind of collectors to provide heat for industrial processes, processing food, room heating, air preheating, drying processes or air conditioning could be significant. However, the technical potentials of the various technological solutions are not easy to compare. Such a compa...

  5. Evaluation of heat transfer enhancement in air-heating collectors

    Energy Technology Data Exchange (ETDEWEB)

    Mattox, D. L.

    1979-06-01

    The present research effort was initiated for the purpose of increasing the thermal efficiency of air heating solar collectors through identification and development of optimum design and operation criteria for solar absorber-to-air heat exchangers. Initially this effort took the form of a solar collector systems analysis to evaluate the impact of various techniques for enhancing the heat transfer between the absorber and air stream on overall thermal performance of the entire solar collector. This systems analysis resulted in the selection of solar collector designs providing ducted cooling air on the absorber shaded side as a base line. A transient heat transfer analysis of a complete solar air heating collector was used to demonstrate that an optimum absorber-to-air heat exchanger design could be provided with several interrupted fin configurations. Additional analyses were performed to establish that the maximum solar collector thermal performance to required pumping power was realized for a Reynolds number range of 1000 to 2000. This Reynolds number range was used to establish a theoretical design limit curve for maximum thermal performance versus required pumping power for all interrupted fin designs as published in the open literature. Heat and momentum transfer empirical relationships were defined for scaling the state-of-the-art high conductance fin designs identified from a compact configuration to the less compact designs needed for solar collectors.

  6. Development of an economic solar heating system with cost efficient flat plate collectors

    Science.gov (United States)

    Eder-Milchgeisser, W.; Burkart, R.

    1980-10-01

    Mass produced flat plate solar collectors were worked into the design of a system for heating a swimming pool and/or providing domestic hot water. The collector characteristics, including physical and mechanical data as well as theoretical energy conversion efficiency, are presented. The collector was tested and service life efficiency was determined. The mounting of the collector, depending on roof type, is explained. Both in service and laboratory test results demonstrate the cost effectiveness of the system. Further improvement of efficiency is envisaged with automatic flow control in the solar collector and hot water circuits.

  7. Experimental evaluation of flat plate solar collector using nanofluids

    International Nuclear Information System (INIS)

    Verma, Sujit Kumar; Tiwari, Arun Kumar; Chauhan, Durg Singh

    2017-01-01

    Highlights: • Solar collectors are special kind of heat exchangers. • Particle concentration is important parameter for thermal conductivity of nanofluid. • Rise of Bejan number indicates systems qualitative response. • Multi walled carbon nanotube is best performing. - Abstract: The present analysis focuses on a wide variety of nanofluids for evaluating performance of flat plate solar collector in terms of various parameters as well as in respect of energy and exergy efficiency. Also, based on our experimental findings on varying mass flow rate, the present investigation has been conducted with optimum particle volume concentration. Experiments indicate that for ∼0.75% particle volume concentration at a mass flow rate of 0.025 kg/s, exergy efficiency for Multi walled carbon nanotube/water nanofluid is enhanced by 29.32% followed by 21.46%, 16.67%, 10.86%, 6.97% and 5.74%, respectively for Graphene/water, Copper Oxide water, Aluminum Oxide/water, Titanium oxide/water, and Silicon Oxide/water respectively instead of water as the base fluid. Entropy generation, which is a drawback, is also minimum in Multiwalled carbon nanotube/water nanofluids. Under the same thermophysical parameters, the maximum drop in entropy generation can be observed in Multiwalled carbon nanotube/water, which is 65.55%, followed by 57.89%, 48.32%, 36.84%, 24.49% and 10.04%, respectively for graphene/water, copper oxide/water, Aluminum/water, Titanium Oxide /water, and Silicon oxide /water instead of water as the base fluid. Rise of Bejan number towards unity emphasizes improved system performance in terms of efficient conversion of the available energy into useful functions. The highest rise in energy efficiency of a collector has been recorded in Multiwalled carbon nanotube/water, which is 23.47%, followed by 16.97%, 12.64%, 8.28%, 5.09% and 4.08%, respectively for graphene/water, Copper oxide/water, Aluminum oxide/water, Titanium oxide /water, and Silicon oxide/water instead of

  8. Air solar collectors in building use - A review

    Science.gov (United States)

    Bejan, Andrei-Stelian; Labihi, Abdelouhab; Croitoru, Cristiana; Catalina, Tiberiu

    2018-02-01

    In the current energy and environmental context it is imperative to implement systems based on renewable energy sources in order to reduce energy consumptions worldwide. Solar collectors are studied by many years and many researchers are focusing their attention in order to increase their efficiency and cost-effectiveness. Water solar collectors are often implemented for domestic hot water, heating or industrial processes and already have a place on the market. A promising system which is not yet widely known is represented by air solar collectors that could represent an efficient way to use the solar energy with a lower investment cost, a system that can be used in order to preheat the fresh air required for heating, drying, or to maintain a minimum temperature during winter. This paper presents a comprehensive literature review on air solar collectors used mainly in buildings, acting as a solar wall. Air solar collectors are roughly classified into two types: glazed and opaque. The present study comprises the solar collector classification, applications and their main parameters with a special focus on opaque solar collectors.

  9. Air solar collectors in building use - A review

    Directory of Open Access Journals (Sweden)

    Bejan Andrei-Stelian

    2018-01-01

    Full Text Available In the current energy and environmental context it is imperative to implement systems based on renewable energy sources in order to reduce energy consumptions worldwide. Solar collectors are studied by many years and many researchers are focusing their attention in order to increase their efficiency and cost-effectiveness. Water solar collectors are often implemented for domestic hot water, heating or industrial processes and already have a place on the market. A promising system which is not yet widely known is represented by air solar collectors that could represent an efficient way to use the solar energy with a lower investment cost, a system that can be used in order to preheat the fresh air required for heating, drying, or to maintain a minimum temperature during winter. This paper presents a comprehensive literature review on air solar collectors used mainly in buildings, acting as a solar wall. Air solar collectors are roughly classified into two types: glazed and opaque. The present study comprises the solar collector classification, applications and their main parameters with a special focus on opaque solar collectors.

  10. An Experimental and Analytical Study of a Radiative Cooling System with Unglazed Flat Plate Collectors

    DEFF Research Database (Denmark)

    Hosseinzadeh, Elham; Taherian, Hessam

    2012-01-01

    plate solar collectors in a humid area, Babol, Iran, is assessed both experimentally and numerically. Different methods available in the literature are reviewed and by using a widely accepted model, the sky temperature is determined. The mathematical model for a flat plate solar collector is used...... as a guideline to derive the governing equations of a night sky radiator. Then, a cooling loop, including a storage tank, pump, connecting pipes, and a radiator has been studied experimentally. The water is circulated through the unglazed flat-plate radiator having 4 m2 of collector area at night to be cooled...

  11. Effect of openings collectors and solar irradiance on the thermal efficiency of flat plate-finned collector for indirect-type passive solar dryer

    Science.gov (United States)

    Batubara, Fatimah; Dina, Sari Farah; Klaudia Kathryn Y., M.; Turmuzi, M.; Siregar, Fitri; Panjaitan, Nora

    2017-06-01

    Research on the effect of openings solar collector and solar irradiance to thermal efficiency has been done. Solar collector by flat plate-finned type consists of 3 ply insulator namely wood, Styrofoam and Rockwool with thickness respectively are 10 mm, 25 mm and 50 mm. Absorber plate made of aluminum sheet with thickness of 0.30 mm, painted by black-doff. Installation of 19 units fins (length x height x thickness: 1000x20x10 mm) on the collector will increase surface area of absorber so it can receive much more solar energy. The solar collector cover is made of glass (thickness of 5 mm). During the research, the solar irradiance and temperature of collector are measured and recorded every five minutes. Temperature measurement performed on the surface of the absorber plate, inside of collector, surface cover and the outer side insulator (plywood). This data is used to calculate the heat loss due to conduction, convection and radiation on the collector. Openings of collectors vary as follows: 100%, 75%, 15% and 0% (total enclosed). The data collecting was conducted from 09.00 am to 17.00 pm and triplicates. The collector thermal efficiency calculated based on the ratio of the amount of heat received to the solar irradiance absorbed. The results show that each of openings solar collector has different solar irradiance (because it was done on a different day) which is in units of W/m2: 390 (100% open), 376 (75% open), 429 (15% open), and 359 (totally enclosed). The highest thermal efficiency is in openings variation of 15% opened. These results indicate that the efficiency of the collector is influenced by the solar irradiance received by the collector and the temperature on the collector plate. The highest thermal efficiency is in variation of openings 15%. These indicate that the efficiency of the collector was influenced by solar irradiance received by the collector and openings of the collector plate.

  12. Standardized performance tests of collectors of solar thermal energy-a flat-plate collector with a single-tube serpentine flow distribution

    Science.gov (United States)

    Johnson, S.

    1976-01-01

    This preliminary data report gives basic test results of a flat-plate solar collector whose performance was determined in the NASA-Lewis solar simulator. The collector was tested over ranges of inlet temperatures, fluxes and coolant flow rates. Collector efficienty is correlated in terms of inlet temperature and flux level.

  13. A solar collector for air-conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Kose, E. [Microtherm Energietechnik GmbH, 25 - Lods (France)

    1999-03-01

    A high performance Compound Parabolic Concentrator (CPC) collector is presented. It comprises dewar type tubular vacuum tubes with an absorber coating of very low emittance, a moderately concentrating reflector and a simple thermosyphon heat removal system. The reflectors car be designed with respect to the specific needs; reflector material, concentration, truncation and symmetry car be chosen freely. The collector allows the construction of cooling systems with higher COP's without using tracking systems. Land use and costs are greatly reduced. For a certain application (optimum yearly gain in Munich with a constant collector temperature of 180 deg C) the reflector was optimized, it is a fairly asymmetrical design. A symmetrical design with a similar performance has been tested, the results are shown. (author)

  14. A study of the flat plate solar collector in Guinea

    International Nuclear Information System (INIS)

    Boye Barry, M.

    1990-12-01

    In this paper, we study a collector, made by cheap local materials (wood, aluminium, etc.), and prepared in the carpenteries, and in the mechanic work rooms with a simple technology. The efficiency of our collector is compared with several variants made in other countries. (author). 9 refs, 6 figs, 2 tabs

  15. Performance of jet impingement in unglazed air collectors

    Energy Technology Data Exchange (ETDEWEB)

    Belusko, M.; Saman, W.; Bruno, F. [Institute for Sustainable Systems and Technologies, University of South Australia, Mawson Lakes Boulevard, Mawson Lakes, SA 5095 (Australia)

    2008-05-15

    Jet impingement is effective at improving the heat transfer between air and a heated surface. Studies have shown that jet impingement can marginally improve the thermal efficiency of a glazed collector. However, little attention has been placed on applying jet impingement to an unglazed solar air collector. This paper presents a theoretical and experimental investigation identifying the performance characteristics of jet impingement. Overall, jet impingement was able to improve the thermal efficiency of the collector by 21%. An increase in the pressure loss was also measured but found to be small. The flow distribution of jets along the collector was the most significant factor in determining the efficiency. Increasing the hole spacing was found to improve the efficiency. (author)

  16. Performance of cylindrical plastic solar collectors for air heating

    International Nuclear Information System (INIS)

    Abdullah, A.S.; Bassiouny, M.K.

    2014-01-01

    Highlights: • The study including the combined convective and radiative heat transfer analysis. • The solar collector is manufactured from LDPE films acting as a black absorber. • Comparisons between the experimental data and the theoretical methods have been made. • The thermal efficiency increases with decreasing the major axes of elliptic shape. • The Nusselt number between the absorber and the heated air is determined. - Abstract: A theoretical and experimental study including the combined convective and radiative heat transfer analysis of a flexible cylindrical type solar air-heater for agriculture crops dehydration as well as heating processes is presented. The solar collector is manufactured from LDPE films acting as a black absorber with a back insulation and double transparent covers sealed together along its edges. The collector is to be blown with a flow of pressurized air. The experiments are carried out with solar collectors of circular shapes having 0.5 m diameter and solar collectors of elliptic shapes having 0.55 m and 0.65 m major axis. Energy balance of the cover, absorber and air yield three simultaneous quadratic algebraic equations in the three unknowns namely, cover, absorber and outlet air temperatures. A computer program is written for calculating the outlet temperature using the Newton–Raphson method and the collector thermal efficiency in terms of its diameter, length, mass flow rate, inlet temperature and solar insolation. Moreover the Nusselt number between the absorber and the heated air is determined experimentally in relation with the Reynolds number. Comparisons between the experimental data and the theoretical methods for the collector efficiency demonstrate a good agreement. In addition of this, the present experimental results of Nusselt number are correlated and compared with a correlation of another authors

  17. Effect of Glass Thickness on Performance of Flat Plate Solar Collectors for Fruits Drying

    Directory of Open Access Journals (Sweden)

    Ramadhani Bakari

    2014-01-01

    Full Text Available This study aimed at investigating the effect of thickness of glazing material on the performance of flat plate solar collectors. Performance of solar collector is affected by glaze transmittance, absorptance, and reflectance which results into major heat losses in the system. Four solar collector models with different glass thicknesses were designed, constructed, and experimentally tested for their performances. Collectors were both oriented to northsouth direction and tilted to an angle of 10° with the ground toward north direction. The area of each collector model was 0.72 m2 with a depth of 0.15 m. Low iron (extra clear glass of thicknesses 3 mm, 4 mm, 5 mm, and 6 mm was used as glazing materials. As a control, all collector performances were analysed and compared using a glass of 5 mm thickness and then with glass of different thickness. The results showed that change in glass thickness results into variation in collector efficiency. Collector with 4 mm glass thick gave the best efficiency of 35.4% compared to 27.8% for 6 mm glass thick. However, the use of glass of 4 mm thick needs precautions in handling and during placement to the collector to avoid extra costs due to breakage.

  18. Validation of a simple dynamic thermal performance characterization model based on the piston flow concept for flat-plate solar collectors

    DEFF Research Database (Denmark)

    Deng, Jie; Yang, Ming; Ma, Rongjiang

    2016-01-01

    dynamic model based on the first-order difference method is compared to that of the numerical solution of the collector ordinary differential equation (ODE) model using the fourth-order Runge-Kutta method. The improved thermal inertia model (TIM) on the basis of closed-form solution presented by Deng et....... (2012) for the model turns out to be the collector static response time constant τC by analytical derivation. The nonlinear least squares method is applied to determine the characteristic parameters of a flat-plate solar air collector previously tested by the authors. Then the obtained parameters...

  19. Small-Scale Flat Plate Collectors for Solar Thermal Scavenging in Low Conductivity Environments

    Directory of Open Access Journals (Sweden)

    Emmanuel Ogbonnaya

    2017-01-01

    Full Text Available There is great opportunity to develop power supplies for autonomous application on the small scale. For example, remote environmental sensors may be powered through the harvesting of ambient thermal energy and heating of a thermoelectric generator. This work investigates a small-scale (centimeters solar thermal collector designed for this application. The absorber is coated with a unique selective coating and then studied in a low pressure environment to increase performance. A numerical model that is used to predict the performance of the collector plate is developed. This is validated based on benchtop testing of a fabricated collector plate in a low-pressure enclosure. Model results indicate that simulated solar input of about 800 W/m2 results in a collector plate temperature of 298 K in ambient conditions and up to 388 K in vacuum. The model also predicts the various losses in W/m2 K from the plate to the surroundings. Plate temperature is validated through the experimental work showing that the model is useful to the future design of these small-scale solar thermal energy collectors.

  20. Investigation of one-dimensional heat flow in a solarflat plate collector with sun tracing system

    Directory of Open Access Journals (Sweden)

    H Samimi Akhijahani

    2016-09-01

    variation of total heat flow over the time at different surfaces of the collector is determined by using equation 3: 3 Two cases (solar panel with rotation and without rotation were considered for testing. Data measuring was carried out for 9 hours from 8 to 17. The fluid flow rate was 0.0185m3.s-1. The dryer was installed in an environment with air temperature of 31.6 oC and 31.8 oC, with the air velocity of 0.58 m.s-1 and 0.54 m.s-1 and with the relative air humidity of about 21%and 21.5% at the first and second days, respectively. The dryer had an automatic temperature controller to fix the air temperature with an accuracy of ±0.1 oC. An anemometer Yk-2005AM model was used to regulate the required air velocity. The output data of the thermocouples was recorded by a digital thermometer (DL-9601A, Lutron that was connected to a computer using RS232 cable and recorded the temperature at required point every an hour. The relative humidity of the ambient was measured every hour with a digital hygrometer (HT.3600, Taiwan, accuracy of 3%. By assembling controlling system with a DC motor, a precious photocell and a proper mechanism, the frame would rotate by the sun and followed solar radiation, therefore more solar energy produced in solar panel. Results and Discussion The results of the experiments showed that the heat transfer process increased in both cases from the early morning and reached to its maximum value around 12 to 14 o’clock. The trend was more homogeneous in the dryer by absorber plate without rotation due to the decline of the heat accumulation. The mean temperature rise in the solar dryer without rotation was 37oC and in the solar dryer with rotation was 54oC. Because of the rotation of solar plate, variations of solar radiation were low. Therefore, by rotation of the solar dryer panel the temperature rise was 27oC. The values of heat transfer coefficient in the solar dryer with rotation were decreased by the time. This reduction in the hours before noon is

  1. Solar Thermal AIR Collector Based on New Type Selective Coating

    Directory of Open Access Journals (Sweden)

    Musiy, R.Y.

    2014-01-01

    Full Text Available Based on the best for optical performance and selective coating solar thermal air collector, which operates by solar power on the principle of simultaneous ventilation and heating facilities, is designed. It can be used for vacation homes, museums, wooden churches, warehouses, garages, houses, greenhouses etc.

  2. Humidification dehumidification desalination system using parabolic trough solar air collector

    International Nuclear Information System (INIS)

    Al-Sulaiman, Fahad A.; Zubair, M. Ifras; Atif, Maimoon; Gandhidasan, Palanichamy; Al-Dini, Salem A.; Antar, Mohamed A.

    2015-01-01

    This paper deals with a detailed thermodynamic analysis to assess the performance of an HDH system with an integrated parabolic trough solar collector (PTSC). The HDH system considered is an open air, open water, air heated system that uses a PTSC as an air heater. Two different configurations were considered of the HDH system. In the first configuration, the solar air heater was placed before the humidifier whereas in the second configuration the solar air heater was placed between the humidifier and the dehumidifier. The current study revealed that PTSCs are well suited for air heated HDH systems for high radiation location, such as Dhahran, Saudi Arabia. The comparison between the two HDH configurations demonstrates that the gained output ratio (GOR) of the first configuration is, on average, about 1.5 whereas for the second configuration the GOR increases up to an average value of 4.7. The study demonstrates that the HDH configuration with the air heater placed between the humidifier and the dehumidifier has a better performance and a higher productivity. - Highlights: • Thermodynamic analysis of an HDH system driven by a parabolic trough solar collector was conducted. • The first configuration reveals a GOR of 1.5 while the second configuration reveals a GOR of 4.7. • Effective heating of the HDH system was obtained through parabolic trough solar collector

  3. Comparative performance of twenty-three types of flat plate solar energy collectors

    Science.gov (United States)

    Simon, F. F.

    1975-01-01

    Report compares efficiencies of 23 solar collectors for four different purposes: operating a Rankine-cycle engine, heating or absorption air conditioning, heating hot water, and heating a swimming pool.

  4. Efficiency of liquid flat-plate solar energy collector with solar tracking system

    Directory of Open Access Journals (Sweden)

    Chekerovska Marija

    2015-01-01

    Full Text Available An extensive testing programme is performed on a solar collector experimental set-up, installed on a location in Shtip (Republic of Macedonia, latitude 41º 45’ and longitude 22º 12’, in order to investigate the effect of the sun tracking system implementation on the collector efficiency. The set-up consists of two flat plate solar collectors, one with a fixed surface tilted at 30о towards the South, and the other one equipped with dual-axis rotation system. The study includes development of a 3-D mathematical model of the collectors system and a numerical simulation programme, based on the computational fluid dynamics (CFD approach. The main aim of the mathematical modelling is to provide information on conduction, convection and radiation heat transfer, so as to simulate the heat transfer performances and the energy capture capabilities of the fixed and moving collectors in various operating modes. The feasibility of the proposed method was confirmed by experimental verification, showing significant increase of the daily energy capture by the moving collector, compared to the immobile collector unit. The comparative analysis demonstrates a good agreement between the experimental and numerically predicted results at different running conditions, which is a proof that the presented CFD modelling approach can be used for further investigations of different solar collectors configurations and flow schemes.

  5. Craft-Joule Project: Stagnation proof transparently insulated flat plate solar collector (static)

    Energy Technology Data Exchange (ETDEWEB)

    Oliva, A; Cadafalch, J; Perez-Segarra, C.D. [Universitat Politecnica de Catalunya, Barcelona (Spain)] (and others)

    2000-07-01

    The STATIC (STAgnation proof Transparently Insulated flat plate Solar Collector) project is a Craft-Joule Project within the framework of the Non Nuclear Energy Programme Joule III coordinated by the Centre Technologic de Transferencia de Calor (CTTC). The core group of SMEs involved in the project has its main economical activity in the field of solar thermal systems at low temperature level (domestic hot water, solar heating, etc.). Beyond this, a large application potential exists for solar heating at medium temperature level (from 80 to 160 Celsius degrees) : industrial process heat, solar cooling and air conditioning, solar drying , distillation and desalination. Three of the four SME proposers are located in Southern Europe and in the Caribean, where a continuos increase of the demand for air conditioning and cooling has been demonstrated in the last years. The recent development of flat plate solar collectors with honeycomb-type transparent insulation cover has shown that this type of collectors can become a low cost alternative to evacuated tube and high concentrating CPC collectors in the medium temperature range from 80 to 160 Celsius degrees. With the expected reduction of collector cost, that forms 30%-50% of total system cost, a decisive break-through of solar thermal systems using heat in the medium temperature range can be achieved. The feasibility and good performance of these solar collectors has been proved in several prototypes. Nevertheless, up to now no commercial products are available. In order to reach this, the following developments of new concepts are necessary and are being carried out within this project: solution of the problem of overheating: development of collector versions for different working temperatures: optimization of the design with the support of high level numerical simulation. Several prototypes of the new solar collectors are being tested. System tests will also be carried or for two test arrays of optimized collector

  6. Experimental Evaluation of a Flat Plate Solar Collector Under Hail City Climate

    Directory of Open Access Journals (Sweden)

    N. Ben Khedher

    2018-04-01

    Full Text Available Flat plate solar water heaters are widely used for water heating in low-temperature residential applications. In this paper the thermal performance of a solar flat plate water heater under Hail weather conditions (latitude 27°52΄N longitude ‎41°69΄E was experimentally investigated. Fluid was circulated through the imbedded copper tubes in the flat plate collector and inlet and outlet temperatures of the fluid were noted at five minute intervals. The experimental-time was between 9:00AM-15:00PM. A study was carried out experimentally to present the efficiency curves of a flat plate solar collector at different flow rates. ASHRAE standard 93-2003 was followed for calculation of instantaneous efficiency of solar collector. Result shows that the flow rate of the circulating fluid highly influence the thermal efficiency of the solar collector. Optimum flow rate of 2.5L/min leads to maximum collector efficiency.

  7. Variation of reflected radiation from all reflectors of a flat plate solar collector during a year

    International Nuclear Information System (INIS)

    Pavlović, Zoran T.; Kostić, Ljiljana T.

    2015-01-01

    In this paper the impact of flat plate reflectors (bottom, top, left and right reflectors) made of Al, on total solar radiation on a solar collector during a day time over a whole year is analyzed. An analytical model for determining optimum tilt angles of a collector and reflectors for any point on the Earth is proposed. Variations of reflectors' optimal inclination angles with changes of the collector's optimal tilt angle during the year are also calculated. Optimal inclination angles of the reflectors for the South directed solar collector are calculated and compared to experimental data. It is shown that optimal inclination of the bottom reflector is the lowest in December and the highest in June, while for the top reflector the lowest value is in June and the highest value is in December. On the other hand, optimal inclination of the left and right side reflectors for optimum tilt angle of the collector does not change during the year and it is 66°. It is found that intensity of the solar radiation on the collector increases for about 80% in the summer period (June–September) by using optimally inclined reflectors, in comparison to the collector without reflectors. - Highlights: • The impacts of flat plate reflectors on solar radiation on the collector are given. • The results of the optimal inclinations of reflectors during the year are shown. • The solar radiation on the collector with reflectors is 80% higher in the summer. • This model may be applied on thermal, PV, PV/T and energy harvesting systems

  8. Tårs 10000 m2 CSP + Flat Plate Solar Collector Plant - Cost-Performance Optimization of the Design

    DEFF Research Database (Denmark)

    Perers, Bengt; Furbo, Simon; Tian, Zhiyong

    2016-01-01

    , was established. The optimization showed that there was a synergy in combining CSP and FP collectors. Even though the present cost per m² of the CSP collectors is high, the total energy cost is minimized by installing a combination of collectors in such solar heating plant. It was also found that the CSP......A novel solar heating plant with Concentrating Solar Power (CSP) collectors and Flat Plate (FP) collectors has been put into operation in Tårs since July 2015. To investigate economic performance of the plant, a TRNSYS-Genopt model, including a solar collector field and thermal storage tank...

  9. Modelación de un colector solar para calentamiento de aire; Modelling ofa solar collector for air heating

    Directory of Open Access Journals (Sweden)

    Amadou Koulibaly

    2015-09-01

    Full Text Available En este trabajo es desarrollada la modelación de un colector solar plano para calentamiento de aire operado con convección natural. El análisis del colector mediante balances de masa y energía no estacionarios aplicados a cada uno de los elementos componentes del colector permitió desarrollar un programa en Visual Basic que simula el comportamiento dinámico del colector ante variaciones de las condiciones de operación y variaciones de los parámetros de diseño (dimensiones del colector, tipo de material de cubierta y dimensiones, material de la placa absorbedora y sus dimensiones, eficiencia óptica y tipo y espesor de aislamiento. Los resultados muestran que el software puede ser empleado para el diseño de colectores para calentamiento de aire, además de poder ser empleado para obtener las temperaturas de cada componente del colector y el rendimiento térmico instantáneo. El software también ofrece los elementos para determinar la constante de tiempo que caracteriza la dinámica del colector.In this paper the modeling of a flat solar collector for air heating was developed. This collector works with natural convection. The analysis of the collector was made using unsteady mass and energy balances applied to each component of collector. The equations were solved usinga Visual Basic code with the target to simulate the dynamics performance of the collector when the operating conditions and the design parameters are modified. The dimensions of the collector, the material and dimensions of the covert, the material and dimensions of the absorber plate, the optic efficiency and the type and thin of the insulator are the fundamentals design parameters that can be varied. The results of the simulation show that the software can be used for the design of collectors for heating air. Additionally, the software permits to determine the temperature of each component, the instantaneous efficiency of the collector and offers the elements to obtain

  10. An energy and exergy study of a solar thermal air collector

    Directory of Open Access Journals (Sweden)

    Mohseni-Languri Ehsan

    2009-01-01

    Full Text Available A solar flat plate air collector was manufactured in the north of Iran, and connected to a room as the model to study the possibility of using such solar heating systems in the northern parts of Iran. This collector was tested as a solar air heater to see how good it could be for warming up the test room during the winter. The experimental data obtained through accurate measurements were analyzed using second law approach to find the optimum mass flow rate, which leads to the maximum exergy efficiency. It was found that for the test setup at the test location, a mass flow rate of 0.0011 kg/s is the optimum mass flow rate for tested conditions which leads to the highest second law efficiency.

  11. Potential of roof-integrated solar collectors for preheating air at drying facilities in Northern Thailand

    Energy Technology Data Exchange (ETDEWEB)

    Roman, Franz; Nagle, Marcus; Leis, Hermann; Mueller, Joachim [Institute of Agricultural Engineering 440e, University of Hohenheim, Garbenstrasse 9, 70599 Stuttgart (Germany); Janjai, Serm [Department of Physics, Silpakorn University, Nakhon Pathom (Thailand); Mahayothee, Busarakorn [Department of Food Technology, Silpakorn University, Nakhon Pathom (Thailand); Haewsungcharoen, Methinee [Department of Food Engineering, Chiang Mai University, Chiang Mai (Thailand)

    2009-07-15

    Longan is one of the most widely cropped fruits in Northern Thailand, where a significant amount of the annual harvest is commercially dried and exported as a commodity. Liquefied petroleum gas is generally used as the energy source for heating the drying air, but concern is growing as fuel prices are expected to increase for the foreseeable future. Meanwhile, with the ample solar radiation in Thailand, the roofs of drying facilities could be adapted to serve as solar collectors to preheat the drying air, thus reducing the energy requirement from fossil fuels. In this study, a simulation program for a flat-plate solar air heater was used to estimate the potential to preheat drying air given the conditions of several longan drying facilities. Results showed that solar collectors can replace up to 19.6% of the thermal energy demand during the drying season. Bigger collectors and smaller air channels result in more useful heat, but attention has to be paid to costs and pressure drop, respectively. Annual monetary savings can reach up to THB 56,000 ({approx}US$ 1800 at US$ 1 THB 31). (author)

  12. Evaluation of a tracking flat-plate solar collector in Brazil

    International Nuclear Information System (INIS)

    Maia, Cristiana B.; Ferreira, André G.; Hanriot, Sérgio M.

    2014-01-01

    The continuing research for an alternative power source due to the perceived scarcity of fuel fossils has, in recent years, given solar energy a remarkable edge. Nevertheless, the Earth's daily and seasonal movement affects the intensity of the incident solar radiation. Devices can track the sun in order to ensure optimum positions with regard to incident solar radiation, maximizing the absorbed solar energy, and the useful energy gain. In this paper, a mathematical model is developed to estimate the solar radiation absorbed, the useful energy gain, and the efficiency of a flat-plate solar collector in Brazil. The results for a sun tracking flat-plate solar collector were compared to fixed devices. The full tracking system with rotation about two axes presented higher absorbed energy, when compared to the rotation about a single axe and to a fixed collector. Also, it was shown that the tilt angle for a fixed solar collector does not cause significant variations in the useful energy gain or in the absorbed solar radiation, for the same azimuth angle. - Highlights: • A model was developed for solar radiation based on experimental data for K T . • Useful energy gain and efficiency of a flat-plate solar collector were evaluated for a one-year period. • Several sun tracking systems were compared to fixed devices. • Tilt angle for a fixed device does not significantly affect the useful energy gain

  13. Experimental and numerical investigation of a linear Fresnel solar collector with flat plate receiver

    International Nuclear Information System (INIS)

    Bellos, Evangelos; Mathioulakis, Emmanouil; Tzivanidis, Christos; Belessiotis, Vassilis; Antonopoulos, Kimon A.

    2016-01-01

    Highlights: • A linear Fresnel solar collector with flat plate receiver is investigated. • The collector is investigated experimentally in energetic and exergetic terms. • The developed numerical model is validated with the experimental results. • The operation with thermal oil is also examined with the developed model. • The final results prove satisfying performance for medium temperature levels. - Abstract: In this study a linear Fresnel solar collector with flat plate receiver is investigated experimentally and numerically with Solidworks Flow Simulation. The developed model combines optical, thermal and flow analysis; something innovative and demanding which leads to accurate results. The main objective of this study is to determine the thermal, the optical and the exergetic performance of this collector in various operating conditions. For these reasons, the developed model is validated with the respective experimental data and after this step, the solar collector model is examined parametrically for various fluid temperature levels and solar incident angles. The use of thermal oil is also analyzed with the simulation tool in order to examine the collector performance in medium temperature levels. The experiments are performed with water as working fluid and for low temperature levels up to 100 °C. The final results proved that this solar collector is able to produce about 8.5 kW useful heat in summer, 5.3 kW in spring and 2.9 kW in winter. Moreover, the operation of this collector with thermal oil can lead to satisfying results up to 250 °C.

  14. Design, construction and evaluation of solar flat-plate collector simulator based on the thermohydraulic coefficient

    Directory of Open Access Journals (Sweden)

    H Rahmati Aidinlou

    2017-05-01

    Full Text Available Introduction Increasing the area of absorber plate between the flowed air through the duct can be accomplished by corrugating the absorber plate or by using the artificial roughness underside of the absorber plate as the commercial methods for enhancing the thermohydraulic performance of the flat plate solar air heaters. Evaluation of this requires the construction of separated solar air heater which is costly and time consuming. The constructed solar flat-plate collector simulator can be a sufficient solution for obtaining the heat transfer and thermodynamic parameters for evaluating the absorber plate. The inclined broken roughness was chosen as the optimum roughness which is surrounded by three aluminum smooth walls. Materials and Methods The duct for both smooth and roughened plate have been constructed based on the ASHRAE 93-2010 standard. In order to achieve a fully thermal and hydraulic developed flow, the plenum is constructed. The centrifugal fan is considered by applying the required air volume at the pressure drop obtained by the duct, plenum and the orifice meter. The TSI velocity-meter 8355 is used to measure the velocity of air crossing through the pipe connected to the centrifugal fan. The micro manometer Kimo CPE310-s with the resolution of 0.1 Pa is used to measure the pressure drop across the test section of the smooth and roughened duct. The LM35 sensors are used to measure the absorber plate and air temperature through the test section. Obtained parameters are used to calculate the Nusselt number and friction factor across the test section for smooth and roughened absorber plate. The Nusselt number and friction factor parameters which is obtained for smooth absorber plate based on experimental set-up, is compared with Dittus-Bolter and Blasius equations, respectively, for validating the simulator. By calculating the Nusselt number and friction factor, Stanton number is obtained based on the equation (6, and thermohydraulic

  15. The capture of submicron particles by collector plates - Wind-tunnel investigations

    International Nuclear Information System (INIS)

    Gauthier, Daniel

    1971-01-01

    The deposition of submicron particles on collector plates parallel to the flow was studied experimentally in a wind-tunnel. The validity of a theoretical model based on brownian diffusion was investigated and its Inadequacies tested. The aerosol sample consisted of uranine particles (mean geometrical radius: about 0. 1 μm). The average flow speeds varied from 1 to 10 m/s and the length of the collector plates between 1 and 10 cm. Results showed that capture was mainly due to diffusion and was in good agreement with the theoretical model; however a noticeable deposit of particles on the front part of the collector edge was observed. Sedimentation was insignificant in almost all the cases. (author) [fr

  16. SIMULATION OF SOLAR LITHIUM BROMIDE–WATER ABSORPTION COOLING SYSTEM WITH DOUBLE GLAZED FLAT PLATE COLLECTOR FOR ADRAR

    Directory of Open Access Journals (Sweden)

    ML CHOUGUI

    2014-12-01

    Full Text Available Adrar is a city in the Sahara desert, in southern Algeria known for its hot and dry climate, where a huge amount of energy is used for air conditioning. The aim of this research is to simulate a single effect lithium bromide–water absorption chiller coupled to a double-glazed flat plate collector to supply the cooling loads for a house of 200m2 in Adrar. The thermal energy is stored in an insulated thermal storage tank. The system was designed to cover a cooling load of 10.39KW for design day of July. Thermodynamic model was established to simulate the absorption cycle. The results have shown that the collector mass flow rate has a negligible effect on the minimum required collector area, but it has a significant effect on the optimum capacity of the storage tank. The minimum required collector area was about 65.3 m2, which could supply the cooling loads for the sunshine hours of the design day for July. The operation of the system has also been considered after sunset by saving solar energy.

  17. Thermodynamic analysis of air solar collector

    International Nuclear Information System (INIS)

    Luminosu, Loan; Fara, Laurentiu

    2006-01-01

    The paper presents the experimental study of an air solar installation with a collecting area A c =4.2m 2 and variable working fluid flow rate in the range 0.02/0.06 kg/s. The experimental data are processed statistically through thermodynamic analysis using energy (semi-empirical and exergy methods. The aim of the paper is to establish the optimal air flow rate through this solar thermal system in order to ensure minimum irreversibility of the collecting-heating-cooling process under Romania's insolation conditions. The paper is also a demonstrative example of cost-effective and efficient use of solar energy for heating in Romania. It is experimentally proven that for this solar installation, the optimum air flow rate is of 0.04 kg/s. At a flow rate of 0.04 kg/s, irreversibility has the lowest values for all daytime hours with a maximum at noon (2640 W). For this flow rate the energy efficiency reaches the highest values. The maximum exergy efficiency value is 0 e x-max=0.197. In March 2000 the solar installation operated as an alternative thermal source for heating a garage, having an inner volume V=64.5 m 3 . The efficiency of the solar installation used for heating the garage is η=0.321. The economic ratio defined as the ratio between monetary benefit and financial investment is r=1.82. A value above 1 of ration r shows the economic utility of the solar installation for users who need thermal energy at low heat carrier levels. The study is useful to designers and users of solar thermal systems inCentral Europe as well as in other geographical areas where climatic conditions are comparable to those in South-Western Romania.(Author)

  18. Solar assisted heat pump on air collectors: A simulation tool

    Energy Technology Data Exchange (ETDEWEB)

    Karagiorgas, Michalis; Galatis, Kostas; Tsagouri, Manolis [Department of Mechanical Engineering Educators, ASPETE, N. Iraklio, GR 14121 (Greece); Tsoutsos, Theocharis [Environmental Engineering Dept., Technical University of Crete, Technical University Campus, GR 73100, Chania (Greece); Botzios-Valaskakis, Aristotelis [Centre for Renewable Energy Sources (CRES), 19th km Marathon Ave., GR 19001, Pikermi (Greece)

    2010-01-15

    The heating system of the bioclimatic building of the Greek National Centre for Renewable Energy Sources (CRES) comprises two heating plants: the first one includes an air source heat pump, Solar Air Collectors (SACs) and a heat distribution system (comprising a fan coil unit network); the second one is, mainly, a geothermal heat pump unit to cover the ground floor thermal needs. The SAC configuration as well as the fraction of the building heating load covered by the heating plant are assessed in two operation modes; the direct (hot air from the collectors is supplied directly to the heated space) and the indirect mode (warm air from the SAC or its mixture with ambient air is not supplied directly to the heated space but indirectly into the evaporator of the air source heat pump). The technique of the indirect mode of heating aims at maximizing the efficiency of the SAC, saving electrical power consumed by the compressor of the heat pump, and therefore, at optimizing the coefficient of performance (COP) of the heat pump due to the increased intake of ambient thermal energy by means of the SAC. Results are given for three research objectives: assessment of the heat pump efficiency whether in direct or indirect heating mode; Assessment of the overall heating plant efficiency on a daily or hourly basis; Assessment of the credibility of the suggested simulation model TSAGAIR by comparing its results with the TRNSYS ones. (author)

  19. Influence of nanofluids on the efficiency of Flat-Plate Solar Collectors (FPSC)

    Science.gov (United States)

    Nejad, Marjan B.; Mohammed, H. A.; Sadeghi, O.; Zubeer, Swar A.

    2017-11-01

    A numerical investigation is performed using finite volume method to study the laminar heat transfer in a three-dimensional flat-plate solar collector using different nanofluids as working fluids. Three nanofluids with different types of nanoparticles (Ag, MWCNT and Al2O3 dispersed in water) with 1-2 wt% volume fractions are analyzed. A constant heat flux, equivalent to solar radiation absorbed by the collector, is applied at the top surface of the absorber plate. In this study, several parameters including boundary conditions (different volume flow rates, different fluid inlet temperatures and different solar irradiance at Skudai, Malaysia), different types of nanoparticles, and different solar collector tilt angles are investigated to identify their effects on the heat transfer performance of FPSC. The numerical results reveal that the three types of nanofluid enhance the thermal performance of solar collector compared to pure water and FPSC with Ag nanofluid has the best thermal performance enhancement. For all the cases, the collector efficiency increased with the increase of volume flow rate while fluid outlet temperature decreased. It is found that FPSC with tilt angle of 10° and fluid inlet temperature of 301.15 K has the best thermal performance.

  20. Effect of Collector Aspect Ratio on the Thermal Performance of Wavy Finned Absorber Solar Air Heater

    OpenAIRE

    Abhishek Priyam; Prabha Chand

    2016-01-01

    A theoretical investigation on the effect of collector aspect ratio on the thermal performance of wavy finned absorber solar air heaters has been performed. For the constant collector area, the various performance parameters have been calculated for plane and wavy finned solar air heaters. It has been found that the performance of wavy finned solar air heater improved with the increase in the collector aspect ratio. The performance of wavy finned solar air heater has been found 30 percent hig...

  1. Overall energy, exergy and carbon credit analysis by different type of hybrid photovoltaic thermal air collectors

    International Nuclear Information System (INIS)

    Agrawal, Sanjay; Tiwari, G.N.

    2013-01-01

    Highlights: ► Comparative study of PVT air collectors. ► CO 2 analysis of all type of PVT air collectors. ► Study of thermal energy, exergy gain and exergy efficiency. ► Exergy efficiency of unglazed hybrid PVT tiles air collector is most efficient. - Abstract: In this paper, comparative analysis of different type of photovoltaic thermal (PVT) air collector namely: (i) unglazed hybrid PVT tiles, (ii) glazed hybrid PVT tiles and (iii) conventional hybrid PVT air collectors have been carried out for the composite climate of Srinagar (India). The comparative study has been carried out in terms of overall thermal energy and exergy gain, exergy efficiency and carbon credit earned by different type of hybrid PVT air collectors. It has been observed that overall annual thermal energy and exergy gain of unglazed hybrid PVT tiles air collector is higher by 27% and 29.3% respectively as compared to glazed hybrid PVT tiles air collector and by 61% and 59.8% respectively as compared to conventional hybrid PVT air collector. It has also been observed that overall annual exergy efficiency of unglazed and glazed hybrid PVT tiles air collector is higher by 9.6% and 53.8% respectively as compared to conventional hybrid PVT air collector. On the basis of comparative study, it has been concluded that CO 2 emission reduction per annum on the basis of overall thermal energy gain of unglazed and glazed hybrid PVT tiles air collector is higher by 62.3% and 27.7% respectively as compared to conventional hybrid PVT air collector and on the basis of overall exergy gain it is 59.7% and 22.7%.

  2. Cost estimates for flat plate and concentrator collector arrays

    Science.gov (United States)

    Shimada, K.

    1982-01-01

    The current module and installation costs for the U.S. National Photovoltaic Program's grid-connected systems are significantly higher than required for economic viability of this alternative. Attention is accordingly given to the prospects for installed module cost reductions in flat plate, linear focus Fresnel concentrator, and point focus Fresnel concentrator candidate systems. Cost projections indicate that all three systems would meet near-term and midterm goals, provided that module costs of $2.80/W(p) and $0.70/W(p), respectively, are met. The point focus Fresnel system emerges as the most viable for the near term.

  3. Theoretical study for solar air pretreatment collector/regenerator

    Energy Technology Data Exchange (ETDEWEB)

    Peng Donggen; Zhang Xiaosong; Yin Yonggao [School of Energy and Environment, Southeast Univ., Nanjing (China)

    2008-07-01

    A new liquid regeneration equipment - solar air pretreatment collector/regenerator for liquid desiccant cooling system is put forward in this paper, which is preferable to solution regeneration in hot and moist climate in South China. The equipment can achieve liquid regeneration in lower temperature. When the solution and the air are in ''match'' state in collector/ regenerator, a match air to salt mass ratio ASMR* is found by theoretical study in which there is the largest theoretical storage capacity SC{sub max}. After two new concepts of the effective solution proportion (EPS) and the effective storage capacity (ESC) are defined, it is found by theoretical calculation that when ESP drops from 100% to 67%, ESC raises lowly, not drops and liquid outlet concentration C{sub str} {sub sol} increases from 40% to 49% in which its increment totals to 90%. All these data explain fully that air pretreatment liquid regeneration equipment enables to improve the performance of liquid desiccant cooling system. (orig.)

  4. Selectively coated high efficiency glazing for solar-thermal flat-plate collectors

    International Nuclear Information System (INIS)

    Ehrmann, N.; Reineke-Koch, R.

    2012-01-01

    In order to increase the efficiency of solar-thermal flat-plate collectors at temperatures above 100 °C or with low solar irradiation, we implement a double glazing with a low-emitting (low-e) coating on the inner pane to improve the insulation of the transparent cover. Since commercially available low-e glazing provides only insufficient solar transmittance for the application in thermal flat-plate collectors we are developing a sputter-deposited low e-coating system based on transparent conductive oxides which provides a high solar transmittance of 85% due to additional antireflective coatings and the use of low-iron glass substrates. Durability tests of the developed coating system show that our low e-coating system is well suitable even at high temperatures, humidity and condensation.

  5. Performance of wickless heat pipe flat plate solar collectors having different pipes cross sections geometries and filling ratios

    International Nuclear Information System (INIS)

    Hussein, H.M.S.; El-Ghetany, H.H.; Nada, S.A.

    2006-01-01

    In the present study, the effect of wickless heat pipe cross section geometry and its working fluid filling ratio on the performance of flat plate solar collectors has been investigated experimentally. Three groups of wickless heat pipes having three different cross section geometries (namely, circular, elliptical and semi-circular cross sections) were designed and manufactured. Each group of three wickless heat pipes was charged with three different distilled water filling ratios of 10%, 20% and 35%. Each wickless heat pipe was then incorporated into a prototype flat plate solar collector developed for the purpose of the present study. The prototypes wickless heat pipe flat plate solar collectors have been investigated experimentally at different inlet cooling water temperatures, two different cooling water mass flow rates and under the meteorological conditions of Cairo, Egypt. The experimental results indicate that the elliptical cross section wickless heat pipe flat plate solar collectors have better performance than the circular cross section ones at low water filling ratios. The optimum water filling ratio of the elliptical cross section wickless heat pipe solar collector is about 10%, while it is very close to 20% for the circular cross section one. Also, the water filling ratio corresponding to the flooding limit of the elliptical wickless heat pipe solar collector is lower than that of the circular one. At 20% water filling ratio, the semi-circular cross section wickless heat pipe solar collector has bad performance compared with that of the other cross sections

  6. Collector Efficiency in Downward-Type Double-Pass Solar Air Heaters with Attached Fins and Operated by External Recycle

    Directory of Open Access Journals (Sweden)

    Chii-Dong Ho

    2012-07-01

    Full Text Available The collector efficiency in a downward-type double-pass external-recycle solar air heater with fins attached on the absorbing plate has been investigated theoretically. Considerable improvement in collector efficiency is obtainable if the collector is equipped with fins and the operation is carried out with an external recycle. Due to the recycling, the desirable effect of increasing the heat transfer coefficient compensates for the undesirable effect of decreasing the driving force (temperature difference of heat transfer, while the attached fins provide an enlarged heat transfer area. The order of performances in the devices of same size is: double pass with recycle and fins > double pass with recycle but without fins > single pass without recycle and fins.

  7. A hybrid air conditioner driven by a hybrid solar collector

    Science.gov (United States)

    Al-Alili, Ali

    The objective of this thesis is to search for an efficient way of utilizing solar energy in air conditioning applications. The current solar Air Conditioners (A/C)s suffer from low Coefficient of Performance (COP) and performance degradation in hot and humid climates. By investigating the possible ways of utilizing solar energy in air conditioning applications, the bottlenecks in these approaches were identified. That resulted in proposing a novel system whose subsystem synergy led to a COP higher than unity. The proposed system was found to maintain indoor comfort at a higher COP compared to the most common solar A/Cs, especially under very hot and humid climate conditions. The novelty of the proposed A/C is to use a concentrating photovoltaic/thermal collector, which outputs thermal and electrical energy simultaneously, to drive a hybrid A/C. The performance of the hybrid A/C, which consists of a desiccant wheel, an enthalpy wheel, and a vapor compression cycle (VCC), was investigated experimentally. This work also explored the use of a new type of desiccant material, which can be regenerated with a low temperature heat source. The experimental results showed that the hybrid A/C is more effective than the standalone VCC in maintaining the indoor conditions within the comfort zone. Using the experimental data, the COP of the hybrid A/C driven by a hybrid solar collector was found to be at least double that of the current solar A/Cs. The innovative integration of its subsystems allows each subsystem to do what it can do best. That leads to lower energy consumption which helps reduce the peak electrical loads on electric utilities and reduces the consumer operating cost since less energy is purchased during the on peak periods and less solar collector area is needed. In order for the proposed A/C to become a real alternative to conventional systems, its performance and total cost were optimized using the experimentally validated model. The results showed that for an

  8. Air-liquid solar collector for solar heating, combined heating and cooling, and hot water subsystems

    Science.gov (United States)

    1978-01-01

    A collection of quarterly reports consisting of the installation and layout design of the air collector system for commercial applications, completion of the preliminary design review, detailed design efforts, and preparation of the verification test plan are given. Performance specifications and performance testing of a prototype model of a two manifold, 144 tube air collector array is presented.

  9. Optimum solar flat-plate collector slope: Case study for Helwan, Egypt

    International Nuclear Information System (INIS)

    Elminir, Hamdy K.; Ghitas, Ahmed E.; El-Hussainy, F.; Hamid, R.; Beheary, M.M.; Abdel-Moneim, Khaled M.

    2006-01-01

    This article examines the theoretical aspects of choosing a tilt angle for the solar flat-plate collectors used in Egypt and make recommendations on how the collected energy can be increased by varying the tilt angle. The first objective in this investigation is to perform a statistical comparison of three specific anisotropic models (Tamps-Coulson, Perez and Bugler) to recommend one that is general and is most accurate for estimating the solar radiation arriving on an inclined surface. Then, the anisotropic model that provides the most accurate estimation of the total solar radiation has been used to determine the optimum collector slope based on the maximum solar energy availability. This result has been compared with the results provided by other models that use declination, daily clearness index and ground reflectivity. The study revealed that Perez's model shows the best overall calculated performance, followed by the Tamps-Coulson then Bugler models

  10. Standardized performance tests of collectors of solar thermal energy: A selectively coated, flat-plate copper collector with one transparent cover and a tube-to-tube spacing of 5 5/8 inches

    Science.gov (United States)

    1976-01-01

    This preliminary data report gives basic test results of a flat-plate solar collector whose performance was determined in the NASA-Lewis solar simulator. The collector was tested over ranges of inlet temperatures, fluxes and coolant flow rates. Collector efficiency is correlated in terms of inlet temperature and flux level.

  11. Standard performance tests of collectors of solar thermal energy: A selectively coated, flat-plate copper collector with one transparent cover and a tube-to-tube spacing of 3-7/8 inches

    Science.gov (United States)

    1976-01-01

    Basic test results are given of a flat-plate solar collector whose performance was determined in the NASA-Lewis solar simulator. The collector was tested over ranges of inlet temperatures, fluxes, and coolant flow rates. Collector efficiency is correlated in terms of inlet temperature and flux level.

  12. Performance Analysis of a Shallow Duct Flat Plate Solar Air Heater with and without Porous Media

    Directory of Open Access Journals (Sweden)

    Haroun A.K. Shahad

    2016-12-01

    Full Text Available In this study a flat plate solar air heater with a shallow duct is analyzed experimentally. The collector consists of a 4.5m long air duct with a (20×5cm cross-sectional area. The air duct consists of four channels so that the collector becomes more compact. The collector is studied under the weather conditions of Hilla city – Iraq with latitude and longitude equal 32.3° N and 44.25° E respectively and it is tilted by 45° with the horizontal plane. The effect of the air mass flow rate on the collector performance is also studied.The performance of the collector is analyzed with and without porous media stuffing. The measured parameters are the air and absorber temperatures, air speed and pressure drop. The temperatures are measured by means of type (K thermocouples as this type covers the temperature range of the studied system. The values of the temperature are displayed by temperature data logger devices. The air speed and pressure drop are measured by digital anemometer and manometer devices respectively. The results of the studied system show that as the air mass flow rate increases, the temperature of both the flowing air and the absorber decrease, whilst the efficiency of the collector increases. The results also show that the addition of the steel wool porous material inside the air duct increases the temperature of both the flowing air and the absorber, and by that increases the efficiency of the collector. The porous media also caused an increase in the pressure drop between the outlet air and the atmosphere. This pressure drop increased with the increase in the air mass flow rate

  13. Energy and exergy analysis of a new flat-plate solar air heater having different obstacles on absorber plates

    International Nuclear Information System (INIS)

    Akpinar, Ebru Kavak; Kocyigit, Fatih

    2010-01-01

    This study experimentally investigates performance analysis of a new flat-plate solar air heater (SAH) with several obstacles (Type I, Type II, Type III) and without obstacles (Type IV). Experiments were performed for two air mass flow rates of 0.0074 and 0.0052 kg/s. The first and second laws of efficiencies were determined for SAHs and comparisons were made among them. The values of first law efficiency varied between 20% and 82%. The values of second law efficiency changed from 8.32% to 44.00%. The highest efficiency were determined for the SAH with Type II absorbent plate in flow channel duct for all operating conditions, whereas the lowest values were obtained for the SAH without obstacles (Type IV). The results showed that the efficiency of the solar air collectors depends significantly on the solar radiation, surface geometry of the collectors and extension of the air flow line. The largest irreversibility was occurring at the SAH without obstacles (Type IV) collector in which collector efficiency is smallest. At the end of this study, the energy and exergy relationships are delivered for different SAHs.

  14. Thermal performance of an open thermosyphon using nanofluid for evacuated tubular high temperature air solar collector

    International Nuclear Information System (INIS)

    Liu, Zhen-Hua; Hu, Ren-Lin; Lu, Lin; Zhao, Feng; Xiao, Hong-shen

    2013-01-01

    Highlights: • A novel solar air collector with simplified CPC and open thermosyphon is designed and tested. • Simplified CPC has a much lower cost at the expense of slight efficiency loss. • Nanofluid effectively improves thermal performance of the above solar air collector. • Solar air collector with open thermosyphon is better than that with concentric tube. - Abstract: A novel evacuated tubular solar air collector integrated with simplified CPC (compound parabolic concentrator) and special open thermosyphon using water based CuO nanofluid as the working fluid is designed to provide air with high and moderate temperature. The experimental system has two linked panels and each panel includes an evacuated tube, a simplified CPC and an open thermosyphon. Outdoor experimental study has been carried out to investigate the actual solar collecting performance of the designed system. Experimental results show that air outlet temperature and system collecting efficiency of the solar air collector using nanofluid as the open thermosyphon’s working fluid are both higher than that using water. Its maximum air outlet temperature exceeds 170 °C at the air volume rate of 7.6 m 3 /h in winter, even though the experimental system consists of only two collecting panels. The solar collecting performance of the solar collector integrated with open thermosyphon is also compared with that integrated with common concentric tube. Experimental results show that the solar collector integrated with open thermosyphon has a much better collecting performance

  15. Numerical study on the effects of absorptivity on performance of flat plate solar collector of a water heater

    Science.gov (United States)

    Tambunan, D. R. S.; Sibagariang, Y. P.; Ambarita, H.; Napitupulu, F. H.; Kawai, H.

    2018-03-01

    The characteristics of absorber plate of a flat plate solar collector play an important role in the improvement of the performance. In this work, a numerical analysis is carried out to explore the effect of absorptivity and emissivity of absorber plate to the performance of the solar collector of a solar water heater. For a results comparison, a simple a simple solar box cooker with absorber area of 0.835 m × 0.835 m is designed and fabricated. It is employed to heat water in a container by exposing to the solar radiation in Medan city of Indonesia. The transient governing equations are developed. The governing equations are discretized and solved using the forward time step marching technique. The results reveal that the experimental and numerical results show good agreement. The absorptivity of the plate absorber and emissivity of the glass cover strongly affect the performance of the solar collector.

  16. Design and experiment of a new solar air heating collector

    International Nuclear Information System (INIS)

    Shams, S.M.N.; Mc Keever, M.; Mc Cormack, S.; Norton, B.

    2016-01-01

    This paper presents the design and experiment of a CTAH (Concentrating Transpired Air Heating) system. A newly designed solar air heating collector comprised of an inverted perforated absorber and an asymmetric compound parabolic concentrator was applied to increase the intensity of solar radiation incident on the perforated absorber. An extensive literature review was carried out to find the vital factors to improve optical and thermal efficiency of solar air heating systems. A stationary optical concentrator has been designed and experimented. Experimental thermal efficiency remained high at higher air flow rates. The average thermal efficiency was found to be approximately 55%–65% with average radiation above 400 W/m"2 for flow rates in the range of 0.03 kg/s/m"2 to 0.09 kg/s/m"2. Experimental results at air flow rates of 0.03 kg/s/m"2 and 0.09 kg/s/m"2 showed temperature rise of 38 °C and 19.6 °C respectively at a solar radiation intensity of 1000 W/m"2. A comparative performance study shows the thermal performance of CTAH. As the absorber of the CTAH facing downward, it avoids radiation loss and the perforated absorber with tertiary concentrator reduces thermal losses from the system. - Highlights: • Literature review was carried out to improve SAH system performance. • Optimisation factors were optical efficiency; heat loss, weight and cost. • Concentrator was designed to concentrate radiation for 6–7 h. • The highest efficiency of CTAH can be 73%. • It can work as efficient as 60% for a temperature rise of 70 °C.

  17. Investigation of thermal behaviour, pressure drop, and pumping power in a Cu nanofluid-filled solar flat-plate collector

    Directory of Open Access Journals (Sweden)

    Shamshirgaran S. Reza

    2017-01-01

    Full Text Available The evaluations of the performance of solar flat-plate collectors are reported in the literature. A computer program developed by MATLAB has been applied for modelling the performance of a solar collector under steady state laminar conditions. Results demonstrate that Cu-water nanofluid would be capable of boosting the thermal efficiency of the collector by 2.4% at 4% volume concentration in the case of using Cunanofluid instead of just water as the working fluid. It is noteworthy that, dispersing the nanoparticles into the water results in a higher pressure drop and, therefore, a higher power consumption for pumping the nanofluid within the collector. It has been estimated for the collector understudy, that the increase in the pressure drop and pumping power to be around 30%.

  18. Investigation of Thermal Performance of Flat Plate and Evacuated Tubular Solar Collectors According to a New Dynamic Test Method

    DEFF Research Database (Denmark)

    Kong, Weiqiang; Wang, Zhifeng; Fan, Jianhua

    2012-01-01

    obtain fluid thermal capacitance in data processing. Then theoretical analysis and experimental verification are carried out to investigate influencing factors of obtaining accurate and stable second order term. A flat plate and ETC solar collector are compared using both the new dynamic method......A new dynamic test method is introduced. This so called improved transfer function method features on two new collector parameters. One is time term which can indicate solar collector's inner heat transfer ability and the other is a second order term of collector mean fluid temperature which can...... and a standard method. The results show that the improved function method can accurately and robustly estimate these two kinds of solar collectors....

  19. Theoretical and experimental investigation of wickless heat pipes flat plate solar collector with cross flow heat exchanger

    International Nuclear Information System (INIS)

    Hussein, H.M.S.

    2007-01-01

    In this work, a wickless heat pipes flat plate solar collector with a cross flow heat exchanger was investigated theoretically and experimentally under the meteorological conditions of Cairo, Egypt. The author's earlier simulation program of wickless heat pipes flat plate solar water heaters was modified to be valid for the present type of wickless heat pipes solar collector by including the solution of the dimensionless governing equations of the present analysis. For verifying the modified simulation program, a wickless heat pipes flat plate solar collector with a cross flow heat exchanger was designed, constructed, and tested at different meteorological conditions and operating parameters. These parameters include different cooling water mass flow rates and different inlet cooling water temperatures. The comparison between the experimental results and their corresponding simulated ones showed considerable agreement. Under different climatic conditions, the experimental and theoretical results showed that the optimal mass flow rate is very close to the ASHRAE standard mass flow rate for testing conventional flat plate solar collectors. Also, the experimental and theoretical results indicated that the number of wickless heat pipes has a significant effect on the collector efficiency

  20. Achievement report for fiscal 1981 on Sunshine Program survey and research. Joint projects on solar energy between Japan and Australia, etc. (Joint efforts for high-grade flat-plate collector development); 1981 nendo Nichigonado taiyo energy gijutsu kyoryoku jigyo seika hokokusho. Nichigo taiyo energy gijutsu kyoryoku (kokyu heiban collector kaihatsu kyoryoku)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1982-03-01

    Investigated at DET (Division of Energy Technology) are a unit for controlling air convection in between a heat collector heat-collecting plate and the cover, testing methods, and under-floor heat accumulation using a horizontal rock bed. DMC (Division of Mineral Chemistry) is engaged in the study of black Ni selective absorption film formation on a metal plate and a reflection-preventing film for a heat collector. Monash University studies methods for testing heat collectors, transfer of heat, heat pipe, tracking mechanism, etc. Melbourne University is dedicated to computer model calculation involving solar energy utilization. Sydney University deals with collectors, selective absorption films, absorption type refrigerators, heat accumulation, and desalination of water. Under study at New South Wales University are passive solar systems, photothermal collectors, solar cells, etc. The Beaseley Corporation is a manufacturer of heater collectors and water heaters in South Australia, and a visit is paid to the corporation for the study of its manufacturing process. The Rheem Corporation manufactures water heaters in New South Wales, and its presence in the solar collector industry is known. (NEDO)

  1. A Review on Photovoltaic-Thermal (PV-T) Air and Water Collectors

    International Nuclear Information System (INIS)

    Avezov, R.R.; Akhatov, J. S.; Avezova, N. R.

    2011-01-01

    This paper presents the state-of-the-art on photovoltaic-thermal PV-T collectors. There are presented two main classification groups: -Air and -Water PV-Thermal collectors, design and performance evaluation, comparison of the findings obtained by various researchers. The review also covers the description of different designs of air and water PV-T collectors, the results of theoretical and experimental works, focused to optimization of the technical and economical performances in terms of electrical as well as thermal outputs. (authors)

  2. Numerical Study on the Effect of Distribution Plates in the Manifolds on the Flow Distribution and Thermal Performance of a Flat Plate Solar Collector

    Directory of Open Access Journals (Sweden)

    Juan Manuel García-Guendulain

    2018-04-01

    Full Text Available Flow maldistribution represents a problem of particular interest in the engineering field for several thermal systems. In flat plate solar collectors, the thermal efficiency strongly depends on the flow distribution through the riser tubes, where a uniform distribution causes a uniform temperature distribution and therefore a higher efficiency. In this work, a Computational Fluid Dynamics (CFD numerical analysis has been carried out using the commercial software FLUENT®, in order to determine the flow distribution, pressure drop and hence the thermal efficiency of a solar collector with distribution flow plates inside the manifolds. The obtained numerical solution for this type of thermal systems has been validated with experimental results available in literature for laminar and turbulent flow. Four distribution plate configurations were analyzed. Results show that using two distribution plates in each of both manifolds improves the flow uniformity up to 40% under the same operating conditions when distribution plates are not used. Besides, it is shown that there exists an increase in the overall pressure drop which is practically negligible for the tilt angles commonly employed in the installation of flat plate solar collectors in Mexico. The use of closed end distribution plates on the dividing and combining manifolds allows the thermal efficiency to become close to the ideal thermal efficiency which is obtained with a uniform flow distribution.

  3. Development of an air-breathing direct methanol fuel cell with the cathode shutter current collectors

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yufeng; Liu, Xiaowei [Key Laboratory of Micro-Systems and Micro-Structures Manufacturing, Ministry of Education, Harbin 150001 (China); MEMS Center, Harbin Institute of Technology, Harbin 150001 (China); Zhang, Peng; Zhang, Bo; Li, Jianmin; Deng, Huichao [MEMS Center, Harbin Institute of Technology, Harbin 150001 (China)

    2010-06-15

    An air-breathing direct methanol fuel cell with a novel cathode shutter current collector is fabricated to develop the power sources for consumer electronic devices. Compared with the conventional circular cathode current collector, the shutter one improves the oxygen consumption and mass transport. The anode and cathode current collectors are made of stainless steel using thermal stamping die process. Moreover, an encapsulation method using the tailor-made clamps is designed to assemble the current collectors and MEA for distributing the stress of the edges and inside uniformly. It is observed that the maximum power density of the air-breathing DMFC operating with 1 M methanol solution achieves 19.7 mW/cm{sup 2} at room temperature. Based on the individual DMFCs, the air-breathing stack consisting of 36 DMFC units is achieved and applied to power a notebook computer. (author)

  4. Flat plate solar collector for water pre-heating using concentrated solar power (CSP)

    Science.gov (United States)

    Peris, Leonard Sunny; Shekh, Md. Al Amin; Sarker, Imran

    2017-12-01

    Numerous attempt and experimental conduction on different methods to harness energy from renewable sources are being conducted. This study is a contribution to the purpose of harnessing solar energy as a renewable source by using flat plate solar collector medium to preheat water. Basic theory of solar radiation and heat convection in water (working fluid) has been combined with heat conduction process by using copper tubes and aluminum absorber plate in a closed conduit, covered with a glazed through glass medium. By this experimental conduction, a temperature elevation of 35°C in 10 minutes duration which is of 61.58% efficiency range (maximum) has been achieved. The obtained data and experimental findings are validated with the theoretical formulation and an experimental demonstration model. A cost effective and simple form of heat energy extraction method for space heating/power generation has been thoroughly discussed with possible industrial implementation possibilities. Under-developed and developing countries can take this work as an illustration for renewable energy utilization for sustainable energy prospect. Also a full structure based data to derive concentrated solar energy in any geographical location of Bangladesh has been outlined in this study. These research findings can contribute to a large extent for setting up any solar based power plant in Bangladesh irrespective of its installation type.

  5. Optimization of flat-plate solar energy heat pipe collector parameters

    Energy Technology Data Exchange (ETDEWEB)

    Vasiliev, L L; Garakovich, L P; Khrustalev, D K

    1984-01-01

    Performance characteristics of flat solar energy collectors with heat pipes have been analysed with regard to various parameters. Their advantages are discussed. The use of heat pipes in solar energy collectors is proved to be efficient.

  6. Thermal analysis and performance optimization of a solar water heater flat plate collector: Application to Tetouan (Morocco)

    International Nuclear Information System (INIS)

    Dagdougui, Hanane; Ouammi, Ahmed; Robba, Michela; Sacile, Roberto

    2011-01-01

    The development of sustainable energy services like the supply of heating water may face a trade-off with a comfortable quality of life, especially in the winter season where suitable strategies to deliver an effective service are required. This paper investigates the heat transfer process as well as the thermal behavior of a flat plate collector evaluating different cover configurations. This investigation is performed according to a two-folded approach. Firstly, a complete model is formulated and implemented taking into account various modes of heat transfer in the collector. The goal is to investigate the impact of the number and types of covers on the top heat loss and the related thermal performance in order to support decision makers about the most cost-effective design. The proposed model can also be used to investigate the effect of the different parameters which may affect the performance of the collector. Secondly, a two objective constrained optimization model has been formulated and implemented to evaluate the optimality of different design approaches. The goal is to support decision makers in the definition of the optimal water flow and of the optimal collector flat area in order to give a good compromise between the collector efficiency and the output water temperature. The overall methodology has been tested on environmental data (temperature and irradiation) which are characteristic of Tetouan (Morocco). (author)

  7. Analysis of absorbed energy and efficiency of a solar flat plate collector

    Directory of Open Access Journals (Sweden)

    Anderson Miguel Lenz

    2017-07-01

    Full Text Available The highest percentage in home electricity demands in Brazil lies with the water heating systems, where the electric shower has a great contribution in consumption. The use of solar thermal panels is an alternative to minimize the strain on the electrical system by heating water. Current study evaluates a water heating system built with materials commonly used in home constructions. The tested collector is a 1 m² flat plate. Experiments were conducted at the State University of Western Paraná (UNIOESTE, campus Cascavel, Paraná State, Brazil. Temperature data were collected by PT100 sensors and solar radiation was measured with a pyranometer, coupled to a CR-1000 datalogger, with readings and collection every 5 minutes for 1 year. Data collection and analysis showed that the system presented monthly efficiency ranging between 33.7 and 53.54%, and energy absorbed between 30.79 and 75.29 kWh m-².month. Results show the system is a good option for use in residential or rural water heating due to decrease in the electric bill.

  8. Energy, economic and environmental analysis of metal oxides nanofluid for flat-plate solar collector

    International Nuclear Information System (INIS)

    Faizal, M.; Saidur, R.; Mekhilef, S.; Alim, M.A.

    2013-01-01

    Highlights: • By using nanofluid, smaller and compact solar collector can be produced. • The average value of 220 MJ embodied energy can be saved. • The payback period of using nanofluid solar collector is around 2.4 years. • Around 170 kg less CO 2 emissions in average for nanofluid solar collector. • Environmental damage cost is lower with the nanofluid based solar collector. - Abstract: For a solar thermal system, increasing the heat transfer area can increase the output temperature of the system. However, this approach leads to a bigger and bulkier collector. It will then increase the cost and energy needed to manufacture the solar collector. This study is carried out to estimate the potential to design a smaller solar collector that can produce the same desired output temperature. This is possible by using nanofluid as working fluid. By using numerical methods and data from literatures, efficiency, size reduction, cost and embodied energy savings are calculated for various nanofluids. From the study, it was estimated that 10,239 kg, 8625 kg, 8857 kg and 8618 kg total weight for 1000 units of solar collectors can be saved for CuO, SiO 2 , TiO 2 and Al 2 O 3 nanofluid respectively. The average value of 220 MJ embodied energy can be saved for each collector, 2.4 years payback period can be achieved and around 170 kg less CO 2 emissions in average can be offset for the nanofluid based solar collector compared to a conventional solar collector. Finally, the environmental damage cost can also be reduced with the nanofluid based solar collector

  9. Increasing efficiency of a 33 MW OTEC in Indonesia using flat-plate solar collector for the seawater heater

    Directory of Open Access Journals (Sweden)

    Iwan Rohman Setiawan

    2017-07-01

    Full Text Available This paper presents a design concept of Ocean Thermal Energy Conversion (OTEC plant built in Mamuju, West Sulawesi, with 33 MWe and 7.1% of the power capacity and efficiency, respectively. The generated electrical power and the efficiency of OTEC plant are enhanced by a simulation of a number of derived formulas. Enhancement of efficiency is performed by increasing the temperature of the warm seawater toward the evaporator from 26˚C up to 33.5˚C using a flat-plate solar collector. The simulation results show that by increasing these a water temperature up to 33.5˚C, the generated power will increase up to 144.155 MWe with the OTEC efficiency up to 9.54%, respectively. The required area of flat-plate solar collector to achieve the results is around 6.023 x 106 m2.

  10. Solar collecting characteristics of regenerative solar air collector; Chikunetsushiki kuki shunetsuki no shunetsu tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, H; Takano, S; Kamitaira, T [Hachinohe Institute of Technology, Aomori (Japan)

    1997-11-25

    In order to develop a solar drying equipment for agricultural and marine products, a regenerative solar air collector was fabricated on a trial basis, which uses round stones as a heat storing material. Its heat collecting characteristics were discussed. The air heat collector was installed on a roof of the Hachinohe Engineering University facing due south. The inside of the air heat collector is lined with heat insulating material with a thickness of 30 mm, and black-painted round stones were laid as an heat insulating material on the floor and the north face. The collector is of a natural air circulating system in which outside air enters from an entrance open to atmosphere, and warmed air exits from upper exit. A selectively absorbing face plaque for accelerating the natural circulation was suspended on the upper part of the north face of the collector. An experiment was performed also on a case in which air is forcibly circulated by fan from the air exit hole. In the natural circulation system, high heat collecting efficiency is shown in the forenoon. However, heat loss increases as temperature in the equipment rises, and heat stored in the round stones during daytime was dissipated completely in the afternoon to night. In the case of the forced circulation system, heat collecting efficiency as high as about 90% was shown in sunny days. This is thought because of heat storage buffering action due to storage of heat in and its dissipation from the round stones, and because of suppression of heat dissipation from the glass surface. 1 ref., 9 figs.

  11. Comparing between predicted output temperature of flat-plate solar collector and experimental results: computational fluid dynamics and artificial neural network

    Directory of Open Access Journals (Sweden)

    F Nadi

    2017-05-01

    Full Text Available Introduction The significant of solar energy as a renewable energy source, clean and without damage to the environment, for the production of electricity and heat is of great importance. Furthermore, due to the oil crisis as well as reducing the cost of home heating by 70%, solar energy in the past two decades has been a favorite of many researchers. Solar collectors are devices for collecting solar radiant energy through which this energy is converted into heat and then heat is transferred to a fluid (usually air or water. Therefore, a key component in performance improvement of solar heating system is a solar collector optimization under different testing conditions. However, estimation of output parameters under different testing conditions is costly, time consuming and mostly impossible. As a result, smart use of neural networks as well as CFD (computational fluid dynamics to predict the properties with which desired output would have been acquired is valuable. To the best of our knowledge, there are no any studies that compare experimental results with CFD and ANN. Materials and Methods A corrugated galvanized iron sheet of 2 m length, 1 m wide and 0.5 mm in thickness was used as an absorber plate for absorbing the incident solar radiation (Fig. 1 and 2. Corrugations in absorber were caused turbulent air and improved heat transfer coefficient. Computational fluid dynamics K-ε turbulence model was used for simulation. The following assumptions are made in the analysis. (1 Air is a continuous medium and incompressible. (2 The flow is steady and possesses have turbulent flow characteristics, due to the high velocity of flow. (3 The thermal-physical properties of the absorber sheet and the absorber tube are constant with respect to the operating temperature. (4 The bottom side of the absorber tube and the absorber plate are assumed to be adiabatic. Artificial neural network In this research a one-hidden-layer feed-forward network based on the

  12. Hybrid utilization of solar energy. Part 2. Performance analyses of heating system with air hybrid collector; Taiyo energy no hybrid riyo ni kansuru kenkyu. 2. Kuki shunetsu hybrid collector wo mochiita danbo system no seino hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Yoshinaga, M; Okumiya, M [Nagoya University, Nagoya (Japan)

    1996-10-27

    For the effective utilization of solar energy at houses, a heating system using an air hybrid collector (capable of simultaneously performing heat collection and photovoltaic power generation). As the specimen house, a wooden house of a total floor area of 120m{sup 2} was simulated. Collected air is fanned into a crushed stone heat accumulator (capable of storing one day`s collection) or into a living room. The output of solar cell arrays is put into a heat pump (capable of handling a maximum hourly load of 36,327kJ/h) via an inverter so as to drive the fan (corresponding to average insolation on the heat collecting plate of 10.7MJ/hm{sup 2} and heat collecting efficiency of 40%), and shortage in power if any is supplied from the system interconnection. A hybrid collector, as compared with the conventional air collector, is lower in thermal efficiency but the merit that it exhibits with respect to power generation is far greater than what is needed to counterbalance the demerit. When the hybrid system is in heating operation, there is an ideal heat cycle of collection, accumulation, and radiation when the load is light, but the balance between accumulation and radiation is disturbed when the load is heavy. 4 refs., 8 figs., 3 tabs.

  13. Air-borne shape measurement of parabolic trough collector fields

    Science.gov (United States)

    Prahl, Christoph; Röger, Marc; Hilgert, Christoph

    2017-06-01

    The optical and thermal efficiency of parabolic trough collector solar fields is dependent on the performance and assembly accuracy of its components such as the concentrator and absorber. For the purpose of optical inspection/approval, yield analysis, localization of low performing areas, and optimization of the solar field, it is essential to create a complete view of the optical properties of the field. Existing optical measurement tools are based on ground based cameras, facing restriction concerning speed, volume and automation. QFly is an airborne qualification system which provides holistic and accurate information on geometrical, optical, and thermal properties of the entire solar field. It consists of an unmanned aerial vehicle, cameras and related software for flight path planning, data acquisition and evaluation. This article presents recent advances of the QFly measurement system and proposes a methodology on holistic qualification of the complete solar field with minimum impact on plant operation.

  14. Indoor simulation and testing of photovoltaic thermal (PV/T) air collectors

    NARCIS (Netherlands)

    Solanki, S.C.; Dubey, Swapnil; Tiwari, A.

    2009-01-01

    An indoor standard test procedure has been developed for thermal and electrical testing of PV/T collectors connected in series. For this, a PV/T solar air heater has been designed, fabricated and its performance over different operating parameters were studied. Based on the energy balance equations,

  15. Life cycle cost analysis of HPVT air collector under different Indian climatic conditions

    International Nuclear Information System (INIS)

    Raman, Vivek; Tiwari, G.N.

    2008-01-01

    In this communication, a study is carried out to evaluate an annual thermal and exergy efficiency of a hybrid photovoltaic thermal (HPVT) air collector for different Indian climate conditions, of Srinagar, Mumbai, Jodhpur, New Delhi and Banglore. The study has been based on electrical, thermal and exergy output of the HPVT air collector. Further, the life cycle analysis in terms of cost/kWh has been carried out. The main focus of the study is to see the effect of interest rate, life of the HPVT air collector, subsidy, etc. on the cost/kWh HPVT air collector. A comparison is made keeping in view the energy matrices. The study reveals that (i) annual thermal and electrical efficiency decreases with increase in solar radiation and (ii) the cost/kWh is higher in case of exergy when compared with cost/kWh on the basis of thermal energy for all climate conditions. The cost/kWh for climate conditions of Jodhpur is most economical

  16. Modelling and analysis of a heating system for industrial application, using flat-plate solar-collectors with single and double cover glasses

    International Nuclear Information System (INIS)

    Maraslis, A.A.

    1987-01-01

    A calculational methodology for dimensioning a flat-plate solar-collector arrangement, which fulfils the energy requirement of a heat transfer system in one of the steps of the uranium recovery process, from the uranium-phosphorus ore at Itataia, Ceara, in Brazil. The PROSOL-1 and PROSOL-2 computer codes for determining the total area required by collector arrangement-with single and double cover glasses, respectively- taking into account the system design and meteorological conditions of the regions, were used. These codes optimize the series/parallel arranges of collectors in the whole complex and, determine the water flow in each system and the average efficiency of the collector arrangement. The technical and economical feasibility for both collector arrangement with single and double cover glasses, were verified. It was concluded that, the last one is more advantageous, allowing a reduction of 30% in the total collector area. (M.C.K.) [pt

  17. Experimental study of a combined system of solar Kang and solar air collector

    International Nuclear Information System (INIS)

    Wei, Wei; Ji, Jie; Chow, Tin-Tai; He, Wei; Chen, Haifei; Guo, Chao; Yu, Hancheng

    2015-01-01

    Highlights: • A combined system of solar Kang and solar air collector is proposed. • An experimental study on the combined system is made. • The mean air temperature reaches 18.5 °C and maintains above 18 °C for 13 h. • The corresponding mean indoor air temperature of the reference room is 8.9 °C. • The Kang surface temperature reaches 27 °C and maintains above 18 °C for 23 h. - Abstract: Chinese Kang is widely used as heated bed and for heat recovery of cooking stove in Northern China. However there are main drawbacks of indoor and outdoor air pollutant generation and heavy demands on solid fuel handling. A novel combined Kang system, which integrates solar Kang and solar air collector, is here proposed. Experiments were conducted to examine the alternative operating modes: (i) only solar air collector in service, (ii) only solar Kang in service, and (iii) both solar Kang and solar air collector in service. The results show that these three modes behave differently and have distinct effects on room thermal environment in winter. When this pollution-free system operates under the third combined mode, the room temperature increases significantly and the vertical temperature gradient reduces. The Kang surface temperature increases and its uniformity is improved. It is also found that the room air temperature is closely related to the Kang surface temperature. Furthermore, most of the time the thermal environment meets the occupant need. This paper reports the experimental work and investigates into the effects on indoor thermal environment as in rural residences in Northern China

  18. Buoyancy effects on thermal behavior of a flat-plate solar collector

    DEFF Research Database (Denmark)

    Fan, Jianhua; Furbo, Simon

    2008-01-01

    Theoretical and experimental investigations of the flow and temperature distribution in a 12.53 m(2) solar collector panel with an absorber consisting of two vertical manifolds interconnected by 16 parallel horizontal fins have been carried out. The investigations are focused on overheating...... and the influence of the buoyancy effects are considered in the investigations. Further experimental investigations of the solar collector panel are carried out. The flow distribution through the absorber is evaluated by means of temperature measurements on the back of the absorber tubes. The measured temperatures....... The CFD calculations elucidate the flow and temperature distribution in the collector panels of different designs. Based on the investigations, recommendations are given in order to avoid overheating or boiling problems in the solar collector panel....

  19. Development and evaluation of a multiple-plate fraction collector for sample processing: application to radioprofiling in drug metabolism studies.

    Science.gov (United States)

    Barros, Anthony; Ly, Van T; Chando, Theodore J; Ruan, Qian; Donenfeld, Scott L; Holub, David P; Christopher, Lisa J

    2011-04-05

    Microplate scintillation counters are utilized routinely in drug metabolism laboratories for the off-line radioanalysis of fractions collected during HPLC radioprofiling. In this process, the current fraction collection technology is limited by the number of plates that can be used per injection as well as the potential for sample loss due to dripping or spraying as the fraction collector head moves from well to well or between plates. More importantly, sample throughput is limited in the conventional process, since the collection plates must be manually exchanged after each injection. The Collect PAL, an innovative multiple-plate fraction collector, was developed to address these deficiencies and improve overall sample throughput. It employs a zero-loss design and has sub-ambient temperature control. Operation of the system is completely controlled with software and up to 24 (96- or 384-well) fraction collection plates can be loaded in a completely automated run. The system may also be configured for collection into various-sized tubes or vials. At flow rates of 0.5 or 1.0 mL/min and at collection times of 10 or 15s, the system precisely delivered 83-μL fractions (within 4.1% CV) and 250-μL fractions (within 1.4% CV), respectively, of three different mobile phases into 12 mm × 32 mm vials. Similarly, at a flow rate of 1 mL/min and 10s collection times, the system precisely dispensed mobile phase containing a [(14)C]-radiolabeled compound across an entire 96-well plate (% CV was within 5.3%). Triplicate analyses of metabolism test samples containing [(14)C]buspirone and its metabolites, derived from three different matrices (plasma, urine and bile), indicated that the Collect PAL produced radioprofiles that were reproducible and comparable to the current technology; the % CV for 9 selected peaks in the radioprofiles generated with the Collect PAL were within 9.3%. Radioprofiles generated by collecting into 96- and 384-well plates were qualitatively comparable

  20. Collector Efficiency in Downward-Type Internal-Recycle Solar Air Heaters with Attached Fins

    Directory of Open Access Journals (Sweden)

    Chii-Dong Ho

    2013-10-01

    Full Text Available The internal-recycle operation effect on collector efficiency in downward-type rectangular solar air heaters with attached fins is theoretically investigated. It is found that considerable collector efficiency is obtainable if the collector has attached fins and the operation is carried out with internal recycling. The recycling operation increases the fluid velocity to decrease the heat transfer resistance, compensating for the undesirable effect of decreasing the heat transfer driving force (temperature difference due to remixing. The attached fins provide an enlarged heat transfer area. The order of performance in a device of same size is: double pass with recycle and fins > double pass with recycle but without fins > single pass without recycle and fins.

  1. Copper current collectors reduce long-term fouling of air cathodes in microbial fuel cells

    KAUST Repository

    Myung, Jaewook; Yang, Wulin; Saikaly, Pascal; Logan, Bruce E

    2018-01-01

    Long-term operation of wastewater-fed, microbial fuel cells (MFCs) with cathodes made of activated carbon and stainless steel (SS) current collectors can result in decreased performance due to cathode fouling. Copper has good antimicrobial properties, and it is more electrically conductive than SS. To demonstrate that a copper current collector could produce a more fouling resistant cathode, MFCs with air cathodes using either SS or copper current collectors were operated using domestic wastewater for 27 weeks. The reduction in biofouling over time was shown by less biofilm formation on the copper cathode surface compared to SS cathodes, due to the antimicrobial properties of copper. Maximum power densities from 17–27 weeks were 440 ± 38 mW/m2 using copper and 370 ± 21 mW/m2 using SS cathodes. The main difference in the microbial community was a nitrifying community on the SS cathodes, which was not present on the copper cathodes.

  2. Copper current collectors reduce long-term fouling of air cathodes in microbial fuel cells

    KAUST Repository

    Myung, Jaewook

    2018-02-05

    Long-term operation of wastewater-fed, microbial fuel cells (MFCs) with cathodes made of activated carbon and stainless steel (SS) current collectors can result in decreased performance due to cathode fouling. Copper has good antimicrobial properties, and it is more electrically conductive than SS. To demonstrate that a copper current collector could produce a more fouling resistant cathode, MFCs with air cathodes using either SS or copper current collectors were operated using domestic wastewater for 27 weeks. The reduction in biofouling over time was shown by less biofilm formation on the copper cathode surface compared to SS cathodes, due to the antimicrobial properties of copper. Maximum power densities from 17–27 weeks were 440 ± 38 mW/m2 using copper and 370 ± 21 mW/m2 using SS cathodes. The main difference in the microbial community was a nitrifying community on the SS cathodes, which was not present on the copper cathodes.

  3. Solar Air Collectors for Space Heating and Ventilation Applications—Performance and Case Studies under Romanian Climatic Conditions

    Directory of Open Access Journals (Sweden)

    Sanda Budea

    2014-06-01

    Full Text Available Solar air collectors have various applications: on the one hand, they can be used for air heating in cold seasons; on the other hand they can be used in summer to evacuate the warm and polluted air from residential, offices, industrial, and commercial buildings. The paper presents experimental results of a solar collector air, under the climatic conditions of the Southeastern Europe. The relationships between the direct solar irradiation, the resulting heat flow, the air velocity at the outlet, the air flow rate, the nominal regime of the collector and the efficiency of conversion of solar energy into thermal energy are all highlighted. Thus, it was shown that after a maximum 50 min, solar air collectors, with baffles and double air passage can reach over 50% efficiency for solar irradiation of 900–1000 W/m2. The article also presents a mathematical model and the results of a computational program that allows sizing solar collectors for the transfer of air, with the purpose of improving the natural ventilation of buildings. The article is completed with case studies, sizing the area to be covered with solar collectors, to ensure ventilation of a house with two floors or for an office building. In addition, the ACH (air change per hour coefficient was calculated and compared.

  4. A Flat Solar Collector Built from Galvanized Steel Plate, Working by Thermosyphonic Flow, Optimized for Mexican Conditions

    OpenAIRE

    Marroquín de Jesús, Á.; Olivares-Ramírez, J.M.; Ramos-López, G.A.; Pless, R.C.

    2009-01-01

    Design, construction, and testing of the thermal performance of a flat solar collector for domestic water heating are described. The absorbing plate is built from readily available materials: two sheets of galvanized steel, one of the channelled type, the other one flat, which are joined by electric welding. The absorber is connected to a 198-L thermotank, insulated with polyurethane foam. In terms of receiving surface, the prototype tested here has an area of 1.35 m², about 20% smaller than ...

  5. A Flat Solar Collector Built from Galvanized Steel Plate, Working by Thermosyphonic Flow, Optimized for Mexican Conditions

    OpenAIRE

    Á. Marroquín de Jesús; J.M. Olivares–Ramírez; G.A. Ramos–López; R.C. Pless

    2009-01-01

    Design, construction, and testing of the thermal performance of a flat solar collector for domestic water heating are described. The absorbing plate is built from readily available materials: two sheets of galvanized steel, one of the channelled type, the other one flat, which are joined by electric welding. The absorber is connected to a 198–L thermotank, insulated with polyurethane foam. In terms of receiving surface, the prototype tested here has an area of 1.35 m2, about 20% smaller than ...

  6. Heat transfer performance of silver/water nanofluid in a solar flat-plate collector

    OpenAIRE

    Lazarus, Godson; Roy, Siddharth; Kunhappan, Deepak; Cephas, Enoch; Wongwises, Somchai

    2015-01-01

    An experimental study is carried out to investigate the heat transfer characteristics of silver/water nanofluid in a solar flatplate collector. The solar radiation heat flux varies between 800 W/m2and 1000W/m2, and the particle concentration varies between 0.01%, 0.03%, and 0.04%. The fluid Reynolds number varies from 5000 to 25000. The influence of radiation heat flux, mass flow rate of nanofluid, inlet temperature into the solar collector, and volume concentration of the particle on the con...

  7. Prize-winning energy conservation house equipped with air collectors at Bad Vilbel

    Energy Technology Data Exchange (ETDEWEB)

    Urbanek, A.

    An energy conservation house is the winner out of a total of 60 designs and is displayed at the prefabricated-house exhibition at Bad Vilbel. Similar to Socrates' building in antiquity, this house constitutes a triangle both perpendicularly and horizontally opening its largest possible surface to the South. Any 'residual heat' needed for the Northern roof planted over, is supplied by the air collectors either directly or by means of a high-performance heat pump via heating of the controlled feed air through a novel air floor heating installation while removing energy, too, from the exhaust air through heat recovery. In a survey supported by photos of models and buildings, lay-out plans and connector diagrams of energy supply, technical details of the heat protection concept (aerated concrete for walls, ceilings, roofing structures) and the energy concept with air collectors are described along with a discussion of heat pump operation, the novel air floor heating system and the solar cycle control system. Every room has a miniature heat exchanger allocated in the central unit so that re-heated air can be demanded via the separate room thermostat depending on reflow-air temperature.

  8. Side-by-side comparisons of evacuated compound parabolic concentrator and flat plate solar collector systems at temperatures of 90 to 100C

    Science.gov (United States)

    Allen, J. W.; Schertz, W. W.; Wantroba, A. S.

    1987-03-01

    This collector system study is an extension of a previous system study in which Argonne National Laboratory (ANL) compared the performance of three solar energy systems operated side by side for over a year. In the present system study, four solar energy systems were operated side by side for part of a year. Two of the collector systems used commercially available compound parabolic concentrator (CPC) collectors, one used a commercially available flat plate collector, and one used an experimental CPC collector built by The University of Chicago. The collectors were mounted in fixed positions; they did not track the Sun, and their tilt angles were not seasonally adjusted. All of the collector arrays faced south and were tilted at 42 deg with respect to the horizon (to match the 42 deg N latitude at ANL). All four collector systems started each day with their storage temperatures at 90 C. During the day, each system was operated by its own solar controller. At the end of the day, the tanks were mixed and the temperature changes in the tanks were measured. The change in storage energy was calculated from the temperature change, the heat capacity of the storage system, and the pump energy.

  9. Optimum selection of solar collectors for a solar-driven ejector air conditioning system by experimental and simulation study

    International Nuclear Information System (INIS)

    Zhang Wei; Ma Xiaoli; Omer, S.A.; Riffat, S.B.

    2012-01-01

    Highlights: ► Three solar collectors have been compared to drive ejector air conditioning system. ► A simulation program was constructed to study the effect parameters. ► The outdoor test were conducted to validate the solar collector modeling. ► Simulation program was found to predict solar collector performance accurately. ► The optimal design of solar collector system was carried out. - Abstract: In this paper, three different solar collectors are selected to drive the solar ejector air conditioning system for Mediterranean climate. The performance of the three selected solar collector are evaluated by computer simulation and lab test. Computer model is incorporated with a set of heat balance equations being able to analyze heat transfer process occurring in separate regions of the collector. It is found simulation and test has a good agreement. By the analysis of the computer simulation and test result, the solar ejector cooling system using the evacuated tube collector with selective surface and high performance heat pipe can be most economical when operated at the optimum generating temperature of the ejector cooling machine.

  10. Diseño de un colector solar de placa plana; Design of a Solar Flat Plate Collector

    Directory of Open Access Journals (Sweden)

    Jeovany Rafael Rodríguez Mejía

    2015-12-01

    Full Text Available En el presente artículo se integra el uso de un software de diseño mecánico y un algoritmo de simulación de la operación de un colector solar de placa plana, con el objetivo de simplificar el proceso de diseño y manufactura de este último. Se exponen los resultados de la simulación de la operación del colector solar considerando diferentes combinaciones en los parámetros de los materiales utilizados, tales como sus propiedades y características físico químicas, además de la variación de las dimensiones del sistema adiseñar. Finalmente en el artículo se evalúa la operación de un colector solar para las condiciones climatológicas típicas de la irradiancia, velocidad de viento y temperatura ambiente a partir de una serie de curvas sinusoidales, típicas de Cuba, validándose la viabilidad del algoritmo como apoyo en la etapa de diseño y selección de materiales.In this article the use of mechanical design software and an algorithm for simulating the operation of a flat plate solar collector, with the objective of simplifying the process of design and manufacture of the latter isintegrated. The simulation results of the operation of the solar collector considering different combinations in the parameters of the materials used, such as its physicochemical properties and features in addition to thevariation of the dimensions of the system design are set. The article finally evaluates the operation of a solar collector for typical climatic conditions of irradiance, wind speed and ambient temperature from a series ofsinusoidal, typical Cuba curves is evaluated, validating the feasibility of the algorithm as support in step design and material selection.

  11. Study of Air Pollution Due to Plasma Cutting Process and Designing Local Ventilation System with Collector in Central Workshop of Mobarakeh Steel Company

    Directory of Open Access Journals (Sweden)

    Farideh Atabi

    2014-06-01

    Full Text Available Background & Objectives : Cutting leads to production of different hazardous agents such as fumes, particles, gases and vapors. In various studies, the effects of fumes, gases, and vapors on workers and environment have been proved. Meanwhile, cutting alloying plates with plasma cutting machine due to containing various alloy materials produces a lot of air pollution. Therefore, using the ventilation system to remove the mentioned pollution has always been noteworthy. Method: This study was performed on plasma cutting machine at Mobarakeh Steel Company. At first, according to ASTM the elements from alloy plates with optical emission spectrometry crm-35000-quantometery were detected, the air pollution from cutting the mentioned plates was sampled and measured using NIOSH 7300 method and according to the ACGIH:VS-72-20, VS-70-12, VS-70-11 VS-916 push-pull ventilation with bag filter collector was designed. Results: Results of sampling from pollution of cutting the alloy material, concentration of iron, lead and cadmium fumes were more than the standard limits. After calculation for push system, air flow volume of 195.163 cfm, outgoing air velocity of 5937.4 fpm and for pull system air flow volume of 12498 cfm, minimum duct velocity of 3000 fpm and velocity pressure of duct of 0.717 inwg, for fan, total pressure of 6.301 inwg, static pressure of 0.587 inwg and power of 20.65 Bhp and for collector with pulse jet cleaning system air to cloth ratio of 7 and dimensions of 6.88ft × 6.56ft × 9.84ft were obtained. Conclusion: The result of study indicated that push pull ventilation compared to other ventilation system s for plasma cutting has more efficiency and makes suitable control for pollution.

  12. Performance augmentation in flat plate solar collector using MgO/water nanofluid

    International Nuclear Information System (INIS)

    Verma, Sujit Kumar; Tiwari, Arun Kumar; Chauhan, Durg Singh

    2016-01-01

    Highlights: • Use of nanofluid improves the performance of solar collector. • Thermo-physical properties of the nanofluid have been discussed. • Optimum particle concentrations are found to exist. • Bejan number reaches closer to unity. - Abstract: In present work, testing of solar collector has been performed for MgO/water working fluid having particle size ∼40 nm and particle volume concentration at 0.25, 0.5, 0.75, 1.0, 1.25 and 1.5% at 0.5, 1.0, 1.5, 2.0, 2.5 lpm respectively. Performance analysis of solar collector is based on first law of energy balance and qualitative nature of energy flow based on second law analysis. Parameters of performance analysis are chosen in order to examine both quantitative and qualitative characteristics of system performance. These parameters are thermal efficiency, energetic efficiency, pumping power, entropy generation; Bejan number and reduction in surface area. Experimental observation establishes thermal efficiency enhancement 9.34% for 0.75% particle volume concentration at flow rate 1.5 lpm. Exergetic efficiency enhancement observed 32.23% for same concentration and flow rate. Bejan number also reaches closer to unity (0.97) which throws light on systems qualitative response in terms of decline in entropy generation contribution due to internal irreversibilities and frictional heat loss. Entropy generation is 0.0611 W/K for 0.75% particle concentration compare to 0.1394 W/K for same flow rate and 0.071 W/K for 1.5% particle volume concentration. In this endeavor some penalty in form of rise in pumping power loss also incurred. 6.84% enhancement in pumping power loss observed for optimum flow rate and particle volume concentration which has not as much pronounced effect as enhancement in thermal efficiency and exergetic efficiency.

  13. A Comparison of the Thermodynamic Efficiency of Vacuum Tube and Flat Plate Solar Collector Systems

    Directory of Open Access Journals (Sweden)

    Juozas Bielskus

    2013-12-01

    Full Text Available The article presents simulation based exergy analysis used for comparing solar thermal systems applied for preparing domestic hot water. The simulation of flat and vacuum tube solar collector systems was performed in TRNSYS simulation environment. A period of one year under Lithuanian climate conditions was chosen. Simulation was performed on 6 min time step resolution by calculating energy and exergy flows and creating balance calculation. Assessment results at system and element levels have been presented as monthly variation in efficiency. The conducted analysis has revealed that the systems designed to cover equal heat energy demand operates in different exergetic efficiencies.Article in Lithuanian

  14. Theoretical storage capacity for solar air pretreatment liquid collector/regenerator

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Donggen; Zhang, Xiaosong; Yin, Yonggao [School of Energy and Environment, Southeast University, Nanjing 210096 (China)

    2008-08-15

    A new liquid regeneration equipment - solar air pretreatment collector/regenerator for liquid desiccant cooling system is put forward in this paper, which is preferable to solution regeneration in hot and moist climate in South China. The equipment can achieve liquid regeneration in lower temperature. When the solution and the air are in ''match'' state in collector/regenerator, a match air to salt mass ratio ASMR* is found by theoretical study in which there is the largest theoretical storage capacity SC{sub max}. At T{sub r} = 60{sup o}C and X{sub in} 2.33 kg/kg, theoretical calculation discovers when Y{sub in} drops from 29 to 14 g/kg, the SC{sub max} increase 50% compared with ASMR{sup *} being around 26-27. After two new concepts of the effective solution proportion (EPS) and the effective storage capacity (ESC) are defined, it is found by theoretical calculation that when ESP drops from 100% to 67%, ESC raises lowly, not drops and liquid outlet concentration C{sub str.sol} increases from 40% to 49% in which its increment totals to 90%. All these data explain fully that air pretreatment liquid regeneration equipment enables to improve the performance of liquid desiccant cooling system. (author)

  15. A Flat Solar Collector Built from Galvanized Steel Plate, Working by Thermosyphonic Flow, Optimized for Mexican Conditions

    Directory of Open Access Journals (Sweden)

    Á. Marroquín de Jesús

    2009-07-01

    Full Text Available Design, construction, and testing of the thermal performance of a flat solar collector for domestic water heating are described. The absorbing plate is built from readily available materials: two sheets of galvanized steel, one of the channelled type, the other one flat, which are joined by electric welding. The absorber is connected to a 198–L thermotank, insulated with polyurethane foam. In terms of receiving surface, the prototype tested here has an area of 1.35 m2, about 20% smaller than comparable copper–tube–based collectors offered in the market. Temperature measurements conducted over a 30–day period gave values which were a few degrees lower than the theoretically calculated water temperatures. Momentary thermal efficiency values between 35% and 77% were observed. The water temperature achieved in the tank at the end of the day aver ages 65°C in winter weather conditions in the central Mexican highland. This design of solar water heater is well suited to Mexican conditions, as it makes use of the high local intensity of the solar radiation, and as the channel shape of the ducts minimizes bursting during the rare occurrences of freezing temperatures in the region; it also has the advantage of being manufacturable at low cost from simple materials.

  16. Experimental investigation and thermodynamic performance analysis of a solar dryer using an evacuated-tube air collector

    International Nuclear Information System (INIS)

    Lamnatou, Chr.; Papanicolaou, E.; Belessiotis, V.; Kyriakis, N.

    2012-01-01

    Highlights: ► We evaluate an evacuated-tube solar air collector and use it to develop a novel dryer. ► Apple, carrot and apricot thin-layer drying experiments are conducted. ► Best overall fitting among several available thin-layer drying models is pursued. ► Thermodynamic analysis yields optimal collector area, energy utilization/exergy loss. ► The proposed dryer has a capacity for drying larger quantities of products. -- Abstract: The present work presents a thermodynamic performance analysis of a solar dryer with an evacuated-tube collector. Drying experiments for apples, carrots and apricots were conducted, after a preliminary stage of the investigation which included measurements for the determination of the collector efficiency. These results showed that the warm outlet air of the collector attains temperature levels suitable for drying of agricultural products without the need of preheating. Thus, the present collector was used as the heat source for a drying chamber in the frame of the development of a novel, convective, indirect solar dryer; given the fact that in the literature there are only a few studies about this type of collectors in conjunction with solar drying applications. Thin-layer drying models were fitted to the experimental drying curves, including the recent model of Diamante et al. which showed good correlation coefficients for all the tested products. Drying parameters such as moisture ratio and drying rates were calculated. Furthermore, an energetic/exergetic analysis of the dryer was also conducted and performance coefficients such as pick-up and exergy efficiencies, energy utilization ratio, exergy losses were determined for several configurations such as single and double-trays and several drying air velocities. On the other hand, an optimal collector surface area study was conducted, based on laws for minimum entropy generation. Design parameters such as optimum collector area were determined based on the minimum entropy

  17. The Thermal Collector With Varied Glass Covers

    International Nuclear Information System (INIS)

    Luminosu, I.; Pop, N.

    2010-01-01

    The thermal collector with varied glass covers represents an innovation realized in order to build a collector able to reach the desired temperature by collecting the solar radiation from the smallest surface, with the highest efficiency. In the case of the thermal collector with variable cover glasses, the number of the glass plates covering the absorber increases together with the length of the circulation pipe for the working fluid. The thermal collector with varied glass covers compared to the conventional collector better meet user requirements because: for the same temperature increase, has the collecting area smaller; for the same collection area, realizes the highest temperature increase and has the highest efficiency. This works is addressed to researchers in the solar energy and to engineers responsible with air-conditioning systems design or industrial and agricultural products drying.

  18. Life cycle assessment of a conventional and plastic solar collector in alternative air-conditioning

    International Nuclear Information System (INIS)

    Algarbi, N. M.

    2006-01-01

    Alternative solar systems include a large number of heat-and mass exchange apparatus (HMTA) with considerable size surfaces. Prequired for realization of the work processes. This result in the increase in the overall dimentions. and cost of the system. The possibility of using the principle of combining the working and auxiliary processes within the (HMTA) has been considred, and the calculation proving the working ability of the alternative system for solving the task of air-condition, obtaining comfort parameters by employing evaporative air-cooling methods only, and a solar system with flat solar collectors to provide for the absorbent regeneration, have been performed. The study shows the importance in using Live Cycle Assessment, study for renewable energy, technologies, where environmental performance is especially important.(Author)

  19. Diseño de un colector solar de placa plana; Design of a solar fl at plate collector

    Directory of Open Access Journals (Sweden)

    Jeovany Rafael Rodríguez Mejía

    2016-02-01

    Full Text Available En el presente artículo se integra el uso de un software de dis eño mecánico y un algoritmo de simulación de la operación de un colector solar de placa plana, con el objeti vo de simplificar el proceso de diseño y manufactura de este último. Se exponen los resultados de la sim ulación de la operación del colector solar considerando diferentes combinaciones en los parámetros de los materiales utilizados, tales como sus propiedades y características físico químicas, además de la var iación de las dimensiones del sistema a diseñar. Finalmente en el artículo se evalúa la operación de un colector solar para las condiciones climatológicas típicas de la irradiancia, velocidad de viento y temperatura ambiente a partir de una serie de curvas sinusoidales, típicas de Cuba, validándose la viabilidad del algoritmo como apoyo en la etapa de diseño y selección de materiales. In this article the use of mechanical design software and an al gorithm for simulating the operation of a flat plate solar collector, with the objective of simplifying the pr ocess of design and manufacture of the latter is integrated. The simulation results of the operation of the sola r collector considering different combinations in the parameters of the materials used, such as its physicochemic al properties and features in addition to the variation of the dimensions of the system design are set. The a rticle finally evaluates the operation of a solar collector for typical climatic conditions of irradiance, wind s peed and ambient temperature from a series of sinusoidal, typical Cuba curves is evaluated, validating the fe asibility of the algorithm as support in step design and material selection.

  20. Thermo-economic optimization of a hybrid solar district heating plant with flat plate collectors and parabolic trough collectors in series

    DEFF Research Database (Denmark)

    Tian, Zhiyong; Perers, Bengt; Furbo, Simon

    2018-01-01

    heating network in this study. The results also show that parabolic trough collectors are economically feasible for district heating networks in Denmark. The generic and multivariable levelized cost of heat method can guide engineers and designers on the design, construction and control of large...... to optimize the hybrid solar district heating systems based on levelized cost of heat. It is found that the lowest net levelized cost of heat of hybrid solar heating plants could reach about 0.36 DKK/kWh. The system levelized cost of heat can be reduced by 5–9% by use of solar collectors in the district...

  1. EXPERIMENTAL STUDY ON DOUBLE PASS SOLAR AIR HEATER WITH MESH LAYERS AS ABSORBER PLATE

    Directory of Open Access Journals (Sweden)

    Raheleh Nowzaria

    2014-01-01

    Full Text Available The double pass solar air heater is constructed and tested for thermal efficiency at a geographic location of Cyprus in the city of Famagusta. The absorber plate was replaced by fourteen steel wire mesh layers, 0.2 × 0.2 cm in cross section opening, and they were fixed in the duct parallel to the glazing. The distance between each set of wire mesh layers is 0.5cm to reduce the pressure drop. The wire mesh layers were painted with black before installing them into the collector. The obtained results show that as the mass flow rate increases, the efficiency of the system also increases. The temperature difference (ΔT between the inlet and outlet air through the system increases as the mass flow rate decreases. The maximum ΔT (53°C is achieved at the flow rate of 0.011 kg/s. The range of the mass flow rate used in this work is between 0.011 and 0.037 kg/s. It is also found that the average efficiency obtained for the double pass air collector is 53.7% for the mass flow rate of 0.037 kg/s.

  2. Experimental Investigation of a Solar Greenhouse Heating System Equipped with a Parabolic Trough Solar Concentrator and a Double-Purpose Flat Plate Solar Collector

    Directory of Open Access Journals (Sweden)

    M Jafari

    2017-10-01

    Full Text Available Introduction Greenhouses provide a suitable environment in which all the parameters required for growing the plants can be controlled throughout the year. Greenhouse heating is one of the most important issues in productivity of a greenhouse. In many countries, heating costs in the greenhouses are very high, having almost 60-80% of the total production costs. In recent years, several studies have attempted to reduce the heating costs of the greenhouses by applying more energy efficient equipment and using the renewable energy sources as alternatives or supplementary to the fossil fuels. In the present study a novel solar greenhouse heating system equipped with a parabolic trough solar concentrator (PTC and a flat-plate solar collector has been developed. Therefore, the aim of this paper is to investigate the performance of the proposed heating system at different working conditions. Materials and Methods The presented solar greenhouse heating system was comprised of a parabolic trough solar concentrator (PTC, a heat storage tank, a pump and a flat plate solar collector. The PTC was constructed from a polished stainless steel sheet (as the reflector and a vacuum tube receiver. The PTC was connected to the tank by using insulated tubes and a water pump was utilized to circulate the working fluid trough the PTC and the heat exchanger installed between walls of the tank. The uncovered solar collector was located inside the greenhouse. During the sunshine time, a fraction of the total solar radiation received inside the greenhouse is absorbed by the solar collector. This rises the temperature of the working fluid inside the collector which led to density reduction and natural flow of the fluid. In other words, the collector works as a natural flow flat plate solar collector during the sunshine time. At night, when the greenhouse temperature is lower than tank temperature, the fluid flows in a reverse direction through the solar collector and the

  3. Development of a correlation for parameter controlling using exergy efficiency optimization of an Al_2O_3/water nanofluid based flat-plate solar collector

    International Nuclear Information System (INIS)

    Shojaeizadeh, Ehsan; Veysi, Farzad

    2016-01-01

    Highlights: • Exergy efficiency optimization of a flat-plate collector with Al_2O_3 nanofluid is studied. • Solar radiation and ambient temperature are assumed to be uncontrollable. • Solar collector inlet temperature is influenced by the presence of reservoir tank. • A suitable exponential correlation is proposed for the optimized exergy efficiency. • This exponential correlation also is used for controlling independent parameters. - Abstract: The current study deals with the exergy efficiency optimization of an Al_2O_3/water nanofluid-based flat-plate solar collector according to a mathematical optimization (Sequential Quadratic Programming (SQP) method). This study takes into account exergy efficiency optimization when solar radiation and ambient temperature parameters are assumed to be uncontrollable and presented to a wide range of transient data of climatic conditions where these might take place during spring and summer seasons of Kermanshah (Iran), and perform two main cases as follows: (1) the fluid temperature at the inlet of solar collector, T_i, is independent of storage tank (open loop); (2) the fluid temperature at the inlet of solar collector, T_i, is influenced by the presence of storage tank (closed loop). In any conditions of each case studies (working fluid with and without nanoparticles), a suitable decreasing exponential correlation as function of T_a/G_t values (i.e. ambient temperature to solar radiation ratio) is developed for the optimized exergy efficiency and also well controlling independent parameters values (mass flow rate of fluid, nanoparticle volume concentration and collector inlet temperature). Also, it is concluded that each of optimized parameters and the optimum exergy efficiency is of a linear relation with each other.

  4. Study on heat collector of the solar system utilizing outdoor air. Experimental results in cases of cold and warm regions; Gaiki donyushiki solar system no shunetsubu ni kansuru kenkyu. Kanreichi to ondanchi ni okeru shunetsu jikken to kosatsu

    Energy Technology Data Exchange (ETDEWEB)

    Komano, S; Ebara, Y [OM Solar Association, Shizuoka (Japan); Wada, H [Wada Building Constructors Co. Ltd., Hokkaido (Japan)

    1996-10-27

    An experiment on heat collection was made in the heat collector of a solar system utilizing outdoor air in cold and warm regions. In this system, outdoor air is heated by the air circulation layer on the roof exposed to solar radiation. The heated air is supplied to the object space for heating and ventilation. In the experiment in a cold region, the heat collection characteristics can be adjusted by putting a baffle plate in the air duct according to the experiment of a glass heat collector. The heat collecting air layer on only the iron roof may leak or freeze in the region subject to coldness or heavy snowfall. Therefore, preheat forms the space of a garret, and the preheat temperature comparatively becomes low. The data in which the heat collection characteristics can be adjusted using only a glass heat collector is required corresponding to the regional situation. In the experiment in a warm region, an experiment was made inclusive of the preheat for which outdoor air is absorbed at the eaves. As a result, the heat collection characteristics of preheat were improved. Moreover, a heat collection temperature of about 60{degree}C was obtained on the heat collection surface including the preheat. 1 ref., 12 figs., 3 tabs.

  5. Performance of solar collectors under low temperature conditions

    DEFF Research Database (Denmark)

    Bunea, Mircea; Eicher, Sara; Hildbrand, Catherine

    The performance of four solar thermal collectors (flat plate, evacuated tube, unglazed with rear insulation and unglazed without rear insulation) was experimentally measured and simulated for temperatures below ambient. The influence of several parameters (e.g. collector inlet temperature, air...... evaluated and results compared to experimental measurements. A mathematical model is also under development to include, in addition to the condensation phenomena, the frost, the rain and the long-wave radiation gains/losses on the rear of the solar collector. While the potential gain from rain was estimated...... to be around 2%, frost heat gains were measured to be up to 40% per day, under specific conditions. Overall, results have shown that unglazed collectors are more efficient than flat plate or evacuated tube collectors at low operation temperatures or for night conditions, making them more suitable for heat pump...

  6. Experimental validation of dynamic simulation of the flat plate collector in a closed thermosyphon solar water heater

    DEFF Research Database (Denmark)

    Taherian, H.; Kolaei, Alireza Rezania; Sadeghi, S.

    2011-01-01

    This work studies the dynamic simulation of thermosyphon solar water heater collector considering the weather conditions of a city in north of Iran. The simulation was done for clear and partly cloudy days. The useful energy, the efficiency diagrams, the inlet and the outlet of collector, center...

  7. Application of local exhaust ventilation system and integrated collectors for control of air pollutants in mining company.

    Science.gov (United States)

    Ghorbani Shahna, Farshid; Bahrami, Abdulrahman; Farasati, Farhad

    2012-01-01

    Local exhaust ventilation (LEV) systems and integrated collectors were designed and implemented in a mining company in order to control emitted air pollutant from furnaces. The LEV was designed for capture and transition of air pollutants emitted from furnaces to the integrated collectors. The integrated collectors including four high efficiency Stairmand model cyclones for control of particulate matter, a venturi scrubber for control of the fine particles, SO(2) and a part of H(2)S to follow them, and a packed scrubber for treatment of the residual H(2)S and SO(2) were designed. Pollutants concentration were measured to determine system effectiveness. The results showed that the effectiveness of LEV for reducing workplace pollution is 91.83%, 96.32% and 83.67% for dust, SO(2) and H(2)S, respectively. Average removal efficiency of particles by combination of cyclone and venturi scrubber was 98.72%. Average removal efficiency of SO(2) and H(2)S were 95.85% and 47.13% for the venturi scrubber and 68.45% and 92.7% for the packed bed scrubber. The average removal efficiency of SO(2) and H(2)S were increased to 99.1% and 95.95% by the combination of venturi and packed bed scrubbers. According to the results, integrated collectors are a good air pollution control option for industries with economic constraints and ancient technologies.

  8. Performance of a solar dryer using hot air from roof-integrated solar collectors for drying herbs and spices

    Energy Technology Data Exchange (ETDEWEB)

    Janjai, S.; Tung, P. [Silpakorn University, Pathom (Thailand). Dept. of Physics

    2005-11-01

    A solar dryer for drying herbs and spices using hot air from roof-integrated solar collectors was developed. The dryer is a bin type with a rectangular perforated floor. The bin has a dimension of 1.0 m x 2.0 m x 0.7 m. Hot air is supplied to the dryer from fiberglass-covered solar collectors, which also function as the roof of a farmhouse. The total area of the solar collectors is 72 m{sup 2}. To investigate its performance, the dryer was used to dry four batches of rosella flowers and three batches of lemon-grasses during the year 2002-2003. The dryer can be used to dry 200 kg of rosella flowers and lemon-grasses within 4 and 3 days, respectively. The products being dried in the dryer were completely protected from rains and insects and the dried products are of high quality. The solar air heater has an average daily efficiency of 35% and it performs well both as a solar collector and a roof of a farmhouse. (author)

  9. The sizes of Flat Plate and Evacuated Tube Collectors with Heat Pipe area as a function of the share of solar system in the heat demand

    Directory of Open Access Journals (Sweden)

    Olek Małgorzata

    2016-01-01

    Full Text Available The popularity of solar collectors in Poland is still increasing. The correct location of the collectors and a relatively high density of solar radiation allow delivering heat even in spite of relatively low ambient temperature. Moreover, solar systems used for heating domestic heat water (DHW in summer allow nearly complete elimination of conventional energy sources (e.g. gas, coal. That is why more and more house owners in Poland decide to install solar system installations. In Poland the most common types of solar collectors are flat plate collectors (FPC and evacuated tube collectors with heat pipe (ETCHP; both were selected for the analysis. The heat demand related to the preparation of hot water, connected with the size of solar collectors’ area, has been determined. The analysis includes FPC and ETCHP and heat demand of less than 10 000 kWh/year. Simulations were performed with the Matlab software and using data from a typical meteorological year (TMY. In addition, a 126–year period of measurements of insolation for Krakow has been taken into account. The HDKR model (Hay, Davis, Klucher, Reindl was used for the calculation of solar radiation on the absorber surface. The monthly medium temperature of the absorber depends on the amount of solar system heat and on the heat demand. All the previously mentioned data were used to determine solar efficiency. Due to the fact that solar efficiency and solar system heat are connected, the calculations were made with the use of an iterative method. Additionally, the upper limit for monthly useful solar system heat is resulted from the heat demand and thus the authors prepared a model of statistical solar system heat deviations based on the Monte Carlo method. It has been found that an increase in the useful solar system heat in reference to the heat demand is associated with more than proportional increase in the sizes of the analyzed surfaces of solar collector types.

  10. Solar air heaters and their applications

    Science.gov (United States)

    Selcuk, M. K.

    1977-01-01

    The solar air heater appears to be the most logical choice, as far as the ultimate application of heating air to maintain a comfortable environment is concerned. One disadvantage of solar air heaters is the need for handling larger volumes of air than liquids due to the low density of air as a working substance. Another disadvantage is the low thermal capacity of air. In cases where thermal storage is needed, water is superior to air. Design variations of solar air heaters are discussed along with the calculation of the efficiency of a flat plate solar air heater, the performance of various collector types, and the applications of solar air heaters. Attention is given to collectors with nonporous absorber plates, collectors with porous absorbers, the performance of flat plate collectors with finned absorbers, a wire mesh absorber, and an overlapped glass plate air heater.

  11. Liquid flat plate collector and pump for solar heating and cooling systems: A collection of quarterly reports

    Science.gov (United States)

    1978-01-01

    Progress in the development, fabrication, and delivery of solar subsystems consisting of a solar operated pump, and solar collectors which can be used in solar heating and cooling, or hot water, for single family, multifamily, or commercial applications is reported.

  12. Experimental validation of dynamic simulation of the flat plate collector in a closed thermosyphon solar water heater

    International Nuclear Information System (INIS)

    Taherian, H.; Rezania, A.; Sadeghi, S.; Ganji, D.D.

    2011-01-01

    This work studies the dynamic simulation of thermosyphon solar water heater collector considering the weather conditions of a city in north of Iran. The simulation was done for clear and partly cloudy days. The useful energy, the efficiency diagrams, the inlet and the outlet of collector, center of the absorber and center of the glass cover temperatures, were obtained. The simulation results were then compared with the experimental results in fall and showed a good agreement.

  13. Membrane air stripping utilizing a plate and frame configuration

    International Nuclear Information System (INIS)

    Boswell, S.T.

    1991-01-01

    Membrane air stripping has recently been proposed as a possible method to remove volatile organic chemicals (VOCs) and radon from drinking water supplies. Current and anticipated regulatory requirements, driven by health consequences, make the removal of these contaminants mandatory. This work examines the use of plate and frame membrane air stripping for the removal of VOCs and radon from a water supply. The theoretical basis of membrane air stripping and a literature review are included. The advantages of membrane air stripping versus other methods of removal, as well as the advantages of a plate and frame configuration versus a hollow fiber configuration for membrane air stripping are discussed. Multiple regression/correlation techniques are used to model mass transfer coefficients and fluid resistances. An economic evaluation is performed using the developed models. The costs of comparable membrane and packed tower air stripping systems are 4.86 cents per thousand gallons versus 4.36 cents per thousand gallons, respectively. This work indicates that plate and frame membrane air stripping may, in fact, prove to be an economical alternative to packed tower aeration and carbon adsorption for the removal of VOCs and radon

  14. Exergetic and Thermoeconomic Analyses of Solar Air Heating Processes Using a Parabolic Trough Collector

    Directory of Open Access Journals (Sweden)

    Miguel Ángel Hernández-Román

    2014-08-01

    Full Text Available This paper presents a theoretical and practical analysis of the application of the thermoeconomic method. A furnace for heating air is evaluated using the methodology. The furnace works with solar energy, received from a parabolic trough collector and with electricity supplied by an electric power utility. The methodology evaluates the process by the first and second law of thermodynamics as the first step then the cost analysis is applied for getting the thermoeconomic cost. For this study, the climatic conditions of the city of Queretaro (Mexico are considered. Two periods were taken into account: from July 2006 to June 2007 and on 6 January 2011. The prototype, located at CICATA-IPN, Qro, was analyzed in two different scenarios i.e., with 100% of electricity and 100% of solar energy. The results showed that thermoeconomic costs for the heating process with electricity, inside the chamber, are less than those using solar heating. This may be ascribed to the high cost of the materials, fittings, and manufacturing of the solar equipment. Also, the influence of the mass flow, aperture area, length and diameter of the receiver of the solar prototype is a parameter for increasing the efficiency of the prototype in addition to the price of manufacturing. The optimum design parameters are: length is 3 to 5 m, mass flow rate is 0.03 kg/s, diameter of the receiver is around 10 to 30 mm and aperture area is 3 m2.

  15. Simulation and parameter analysis of a two-stage desiccant cooing/heating system driven by solar air collectors

    International Nuclear Information System (INIS)

    Li, H.; Dai, Y.J.; Köhler, M.; Wang, R.Z.

    2013-01-01

    Highlights: ► A solar desiccant cooling/heating system is simulation studied. ► The mean deviation is about 10.5% for temperature and 9.6% for humidity ratio. ► The 51.7% of humidity load and 76% of the total cooling can be handled. ► About 49.0% of heating load can be handled by solar energy. ► An optimization of solar air collector has been investigated. - Abstract: To increase the fraction of solar energy might be used in supplying energy for the operation of a building, a solar desiccant cooling and heating system was modeled in Simulink. First, base case performance models were programmed according to the configuration of the installed solar desiccant system and verified by the experimental data. Then, the year-round performance about the system was simulated. Last, design parameters of solar air collectors were optimized that include collector area, air leakage and thermal insulation. Comparison between numerical and experimental results shows good agreement. During the simulation, the humidity load for 63 days (51.7%) can be totally handled by the two-stage desiccant cooling unit. For seasonal total heating load, about 49.0% can be handled by solar energy. Based on optimized results, the thermal energy subsystem functioned to its expected performance in solar energy collection and thermal storage

  16. Tracking system for solar collectors

    Science.gov (United States)

    Butler, B.

    1980-10-01

    A tracking system is provided for pivotally mounted spaced-apart solar collectors. A pair of cables is connected to spaced-apart portions of each collector, and a driver displaces the cables, thereby causing the collectors to pivot about their mounting, so as to assume the desired orientation. The collectors may be of the cylindrical type as well as the flat-plate type. Rigid spar-like linkages may be substituted for the cables. Releasable attachments of the cables to the collectors is also described, as is a fine tuning mechanism for precisely aligning each individual collector.

  17. Experimental and numerical study of heat transfer phenomena, inside a flat-plate integrated collector storage solar water heater (ICSSWH), with indirect heat withdrawal

    International Nuclear Information System (INIS)

    Gertzos, K.P.; Pnevmatikakis, S.E.; Caouris, Y.G.

    2008-01-01

    The thermal behavior of a particular flat-plate integrated collector storage solar water heater (ICSSWH) is examined, experimentally and numerically. The particularity consists of the indirect heating of the service hot water, through a heat exchanger incorporated into front and back major surfaces of the ICSSWH. Natural and forced convection mechanisms are both examined. A prototype tank was fabricated and experimental data of temperature profiles are extracted, during various energy withdrawals. A 3D computational fluid dynamics (CFD) model was developed and validated against experimental results. Numerical predictions are found highly accurate, providing thus the use of the 3D CFD model for the optimization of this and similar devices

  18. Solar power from the supermarket. Water heating, space heating and air conditioning with solar collectors

    Energy Technology Data Exchange (ETDEWEB)

    1976-08-01

    The different ways of utilizing solar energy are discussed. So far, top water heating is still the most practicable and most economical solution. Model houses with solar collectors, built by BBC and Philips, are dealt with in particular.

  19. Dust collector

    Energy Technology Data Exchange (ETDEWEB)

    Sahourin, H.

    1988-03-22

    This invention relates to a dust collector or filter which may be used for large volume cleaning air for gases or for separating out industrial byproducts such as wood chips, sawdust, and shavings. It relies on filtration or separation using only a uniquely configured medium. A primary, but not exclusive, purpose of the invention is to enable very large throughput, capable of separating or filtering of gases containing up to three or more tons of byproduct with a minimum pressure-drop across the device. No preliminary cycloning, to remove major particulates is necessary. The collector generally comprises a continuous and integral filter medium which is suspended from a plurality of downwardly extending frames forming a series of separate elements having a triangular cross-section, each element being relatively wide at the top and narrow at the bottom to define, between adjacent elements, a divergent collecting space which is wide at the bottom. 11 figs.

  20. Turning collectors for solar radiation

    Science.gov (United States)

    Barak, Amitzur Z.

    1976-01-01

    A device is provided for turning a solar collector about the polar axis so that the collector is directed toward the sun as the sun tracks the sky each day. It includes two heat-expansive elements and a shadow plate. In the morning a first expansive element is heated, expands to turn the collector to face the sun, while the second expansive element is shaded by the plate. In the afternoon the second element is heated, expands to turn the collector to face the sun, while the first is shaded by the plate.

  1. Design and simulation of a prototype of a small-scale solar CHP system based on evacuated flat-plate solar collectors and Organic Rankine Cycle

    International Nuclear Information System (INIS)

    Calise, Francesco; D’Accadia, Massimo Dentice; Vicidomini, Maria; Scarpellino, Marco

    2015-01-01

    Highlights: • A novel small scale solar power plant was designed and simulated. • The system is based on evacuated solar thermal collectors and an ORC system. • An average electric efficiency of 10% was found for the ORC. • The efficiency of solar collectors was found to be high in summer (>50%). • Pay-back periods lower than 5 years were estimated, in case of public funding. - Abstract: This paper presents a dynamic simulation model of a novel prototype of a 6 kW e solar power plant. The system is based on the coupling of innovative solar thermal collectors with a small Organic Rankine Cycle (ORC), simultaneously producing electric energy and low temperature heat. The novelty of the proposed system lies in the solar collector field, which is based on stationary evacuated flat-plate solar thermal collectors capable to achieve the operating temperatures typical of the concentrating solar thermal collectors. The solar field consists of about 73.5 m 2 of flat-plate evacuated solar collectors, heating a diathermic oil up to a maximum temperature of 230 °C. A diathermic oil storage tank is employed in order to mitigate the fluctuations due to the variability of solar energy availability. The hot diathermic oil exiting from the tank passes through an auxiliary gas-fired burner which provides eventual additional thermal energy. The inlet temperature of the diathermic oil entering the ORC system varies as a function of the availability of solar energy, also determining an oscillating response of the ORC. The ORC was simulated in Engineering Equation Solver (EES), using zero-dimensional energy and mass balances. The ORC model was subsequently implemented in a more general TRNSYS model, including all the remaining components of the system. The model was used to evaluate the energy and economic performance of the solar CHP system under analysis, in different climatic conditions. The results show that the efficiency of the ORC does not significantly vary during the

  2. Experimental investigation of forced-convection in a finned rhombic tube of the flat-plate solar collectors

    DEFF Research Database (Denmark)

    Taherian, Hessam; Yazdanshenas, Eshagh

    2006-01-01

    Due to scarcity of literature on forced-convection heat transfer in a solar collector with rhombic cross-section absorbing tubes, a series of experiments was arranged and conducted to determine heat transfer coefficient. In this study, a typical rhombic cross-section finned tube of flat...

  3. New collectors from all over the world

    Energy Technology Data Exchange (ETDEWEB)

    Augsten, Eva

    2008-07-01

    Flat-plate collectors are fashionable, even among customers in Shanghai, although China is considered the land of evacuated tubes. Elsewhere, fashion is also a consideration, which partly explains the switch from fin collectors to full-surface collectors. Sun and Wind Energy has put together a list of new collectors from various countries. (orig.)

  4. SolAir. Innovative solar collectors for efficient and cost-effective solar thermal power generation - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Barbato, M. C.; Haueter, Ph.; Bader, R.; Steinfeld, A.; Pedretti, A.

    2008-12-15

    This report presents the main results of the project. The project has been started at the end of 2007 and has been successfully finished in December 2008. The present project of ALE AirLight Energy aims at the engineering investigation and design of a novel concept of a solar collector system for efficient and cost-effective solar thermal power generation. The technology exploits an air-inflated reflective structure to concentrate solar radiation. This new arrangement reduces investment costs of the collector field and promises to be economically competitive. A first prototype, built in 2007, has been redesigned and heavily modified during this project. In the new configuration, by using secondary mirrors, the focal area is located close to the main structure and allows the integration of the receiver into the inflated structure. The topics developed in this document are as follows: (i) Design solutions for the concentrated energy receiver suitable for the revised SolAir concentrator concept. (ii) Solar flux simulation via Monte Carlo method. (iii) New version of the ALE AirLight Energy concentrator prototype. (iv) Prototype radiative flux measurements. (author)

  5. The Solar Dynamic Buffer Zone (SDBZ) curtain wall: Validation and design of a solar air collector curtain wall

    Science.gov (United States)

    Richman, Russell Corey

    Given the increases in both the environmental and economic costs of energy, there is a need to design and building more sustainable and low-energy building systems now. Curtain wall assemblies show great promise---the spandrel panels within them can be natural solar collectors. By using a Solar Dynamic Buffer Zone (SDBZ) in the spandrel cavity, solar energy can be efficiently gathered using the movement of air. There is a need for a numerical model capable of predicting performance of an SDBZ Curtain Wall system. This research designed, constructed and quantified a prototype SDBZ curtain wall system through by experimental testing in a laboratory environment. The laboratory experiments focussed on three main variables: air flow through the system, incoming radiation and collector surface type. Results from the experimental testing were used to validate a one-dimensional numerical model of the prototype. Results from this research show a SDBZ curtain wall system as an effective means of reducing building heating energy consumption through the preheating of incoming exterior ventilation air during the heating season in cold climates. The numerical model showed good correlation with experimental results at higher operating flows and at lower flows when using an apparent velocity at the heat transfer boundary layer. A seasonal simulation for Toronto, ON predicted energy savings of 205 kWh/m2 with an average seasonal efficiency of 28%. This is considered in the upper range when compared to other solar air collectors. Given the lack of published literature for similar systems, this research acts to introduce a simple, innovative approach to collect solar energy that would otherwise be lost to the exterior using already existing components within a curtain wall. Specifically, the research has provided: results from experiments and simulation, a first generation numerical model, aspects of design and construction of the SDBZ curtain wall and specific directions for further

  6. An evaluation of thermodynamic solar plants with cylindrical parabolic collectors and air turbine engines with open Joule–Brayton cycle

    International Nuclear Information System (INIS)

    Ferraro, Vittorio; Marinelli, Valerio

    2012-01-01

    A performance analysis of innovative solar plants operating with cylindrical parabolic collectors and atmospheric air as heat transfer fluid in an open Joule–Brayton cycle, with and without intercooling and regeneration, is presented. The analysis was made for two operating modes of the plants: with variable air flow rate and constant inlet temperature to the turbine and with constant flow rate and variable inlet temperature to the turbine. The obtained results show a good performance of this type of solar plant, in spite of its simplicity; it seems able to compete well with other more complex plants operating with different heat transfer fluids. -- Highlights: ► Innovative CPS solar plants, operating with air in open Joule–Brayton cycle, are proposed. ► They are attractive for their simplicity and present interesting values of global efficiency. ► They seem able to compete well with other more complex solar plants.

  7. Biological sample collector

    Science.gov (United States)

    Murphy, Gloria A [French Camp, CA

    2010-09-07

    A biological sample collector is adapted to a collect several biological samples in a plurality of filter wells. A biological sample collector may comprise a manifold plate for mounting a filter plate thereon, the filter plate having a plurality of filter wells therein; a hollow slider for engaging and positioning a tube that slides therethrough; and a slide case within which the hollow slider travels to allow the tube to be aligned with a selected filter well of the plurality of filter wells, wherein when the tube is aligned with the selected filter well, the tube is pushed through the hollow slider and into the selected filter well to sealingly engage the selected filter well and to allow the tube to deposit a biological sample onto a filter in the bottom of the selected filter well. The biological sample collector may be portable.

  8. Open fibre reinforced plastic (FRP) flat plate collector (FPC) and spray network systems for augmenting the evaporation rate of tannery effluent (soak liquor)

    International Nuclear Information System (INIS)

    Srithar, K.; Mani, A.

    2007-01-01

    Presently, tanneries in Tamilnadu, India are required to segregate the effluent of soaking and pickling sections from other wastewater streams and send it to shallow solar pans for evaporation to avoid land pollution. A large area of solar pans is required for evaporating the water in the effluent at salt concentration in the range of 4-5%. An experimental study has been made by using fibre reinforced plastic flat plate collector (FRP-FPC) and spray system in a pilot plant with a capacity to handle 5000 l per day, which increases the evaporation rate. After increasing the salt concentration level to near saturation limit, the concentrated liquid was sent to conventional solar pans for its continued evaporation and recovery of salt. In this improved system, the rate of evaporation was found to be 30-40% more than that in the conventional solar pans. The performance is compared with the theoretically simulated performance. (author)

  9. Linear concentrating collector as an air heater in the heating system of building in Polish climatic conditions

    Directory of Open Access Journals (Sweden)

    Nemś Magdalena

    2016-01-01

    Full Text Available The article presents the analysis of the performance of a concentrating collector in the heating system of a residential building. Air was used as the working fluid. The heating requirements of the building were determined for each day of the year. The amount of direct irradiation reaching the absorber’s surface on all the days of the year was determined with the use of hourly meteorological data for Wroclaw, shared by the Ministry of Infrastructure and Growth. It was assumed that the collector is equipped with a tracking system working in one axis. Calculations and comparisons were made for the amount of solar irradiation for three values of the receiver’s inclination angle: β1=60°, β2=90° and β3=30°. Statistical method was used in order to determine the optimum inclination of the mirror and the amount of flowing air. This method involves creating a plan of experiment with three levels of changeability for two input factors. In the last stage, the amount of heat obtained from the installation during all the days of the year was analysed. The gains were juxtaposed on the diagram with the building’s heat demand. The analysis has shown that the heat requirements can be met only partially.

  10. Dynamic Modeling of Natural Convection Solar Energy Flat Plate ...

    African Journals Online (AJOL)

    The analytical solutions to the dynamic model of an air-heating flat plate solar energy thermal collector were validated by direct measurement from a physical model constructed for that purpose, of the temperatures of the cover and absorber plates, the inlet and outlet fluids, and the ambient air from morning to evening for ...

  11. No-contact method of determining average working-surface temperature of plate-type radiation-absorbing thermal exchange panels of flat solar collectors for heating heat-transfer fluid

    International Nuclear Information System (INIS)

    Avezova, N.R.; Avezov, R.R.

    2015-01-01

    A brand new no-contact method of determining the average working-surface temperature of plate-type radiation-absorbing thermal exchange panels (RATEPs) of flat solar collectors (FSCs) for heating a heat-transfer fluid (HTF) is suggested on the basis of the results of thermal tests in full-scale quasistationary conditions. (authors)

  12. Irreversibility Analysis of Non Isothermal Flat Plate Solar Collectors for Air Heating with a Dimensionless Model

    Directory of Open Access Journals (Sweden)

    Acosta-Flores José Jesús

    2013-04-01

    Full Text Available En ingeniería nos enfrentamos con problemas tan diversos como la elección del sitio donde debe construirse una carretera, una presa, un puente o un aeropuerto. Las consecuencias de tomar decisiones equivocadas son tan grandes que es conveniente contar con un método eficiente para enfrentar dichas situaciones, ya que siempre existe incertidumbre sobre lo que puede acontecer. En este artículo se presenta dicho método a través de un ejemplo sobre un sistema de protección de huracanes en el que dos actores serán fundamentales: el decisor y el analista. Se ha elegido este ejemplo porque permitiría tomar decisiones que disminuyan los daños que ocasionan los huracanes en nuestro país.

  13. Irreversibility Analysis of Non Isothermal Flat Plate Solar Collectors for Air Heating with a Dimensionless Model

    Directory of Open Access Journals (Sweden)

    Baritto-Loreto Miguel Leonardo

    2013-04-01

    Full Text Available En el presente trabajo, el modelo adimensional desarrollado y validado por Baritto y Bracamonte (2012 para describir el comportamiento térmico de colectores solares de placas planas sin cubierta transparente, se complementa con la ecuación adimensional de balance de entropía para un elemento diferencial de colector solar. El modelo se resuelve para un amplio rango de valores de relaciones de aspecto y número de flujo de masa. A partir de los resultados del modelo se desarrolla un análisis detallado de la influencia de estos parámetros sobre la distribución de irreversibilidades internas a lo largo del colector. Adicionalmente se estudia la influencia de estos parámetros sobre los números de generación de entropía por fricción viscosa, por transferencia de calor y total. Se encuentra que existen combinaciones de los parámetros antes mencionados, para los cuales, la operación del colector es termodinámicamente óptima para números de flujo de masa elevados.

  14. Flat plate solar air heater with latent heat storage

    Science.gov (United States)

    Touati, B.; Kerroumi, N.; Virgone, J.

    2017-02-01

    Our work contains two parts, first is an experimental study of the solar air heater with a simple flow and forced convection, we can use thatlaste oneit in many engineering's sectors as solardrying, space heating in particular. The second part is a numerical study with ansys fluent 15 of the storage of part of this solar thermal energy produced,using latent heat by using phase change materials (PCM). In the experimental parts, we realize and tested our solar air heater in URER.MS ADRAR, locate in southwest Algeria. Where we measured the solarradiation, ambient temperature, air flow, thetemperature of the absorber, glasses and the outlet temperature of the solar air heater from the Sunrise to the sunset. In the second part, we added a PCM at outlet part of the solar air heater. This PCM store a part of the energy produced in the day to be used in peak period at evening by using the latent heat where the PCMs present a grateful storagesystem.A numerical study of the fusion or also named the charging of the PCM using ANSYS Fluent 15, this code use the method of enthalpies to solve the fusion and solidification formulations. Furthermore, to improve the conjugate heat transfer between the heat transfer fluid (Air heated in solar plate air heater) and the PCM, we simulate the effect of adding fins to our geometry. Also, four user define are write in C code to describe the thermophysicalpropriety of the PCM, and the inlet temperature of our geometry which is the temperature at the outflow of the solar heater.

  15. The application of an improved gas and aerosol collector for ambient air pollutants in China

    Science.gov (United States)

    Dong, Huabin; Zeng, Limin; Zhang, Yuanhang; Hu, Min; Wu, Yusheng

    2016-04-01

    An improved Gas and Aerosol Collector (GAC) equipped with a newly designed aerosol collector and a set of dull-polished wet annular denuder (WAD) was developed by Peking University based on a Steam Jet Aerosol Collector (SJAC) sampler. Combined with Ion Chromatography (IC) the new sampler performed well in laboratory tests with high collection efficiencies for SO2 (above 98 %) and particulate sulfate (as high as 99.5 %). An inter-comparison between the GAC-IC system and the filter-pack method was performed and the results indicated that the GAC-IC system could supply reliable particulate sulfate, nitrate, chloride, and ammonium data in field measurement with a much wider range of ambient concentrations. From 2008 to 2015, dozens of big field campaigns (rural and coastal sites) were executed in different parts of China, the GAC-IC system took the chance having its field measurement performance checked repeatedly and provided high quality data in ambient conditions either under high loadings of pollutants or background area. Its measurements were highly correlated with data by other commercial instruments such as the SO2 analyzer, the HONO analyzer, a filter sampler, Aerosol Mass Spectrometer (AMS), etc. over a wide range of concentrations and proved particularly useful in future intensive campaigns or long-term monitoring stations to study various environmental issues such as secondary aerosol and haze formation. During these years of applications of GAC-IC in those field campaigns, we found some problems of several instruments running under field environment and some interesting results could also be drew from the large amount of data measured in near 20 provinces of China. Detail results will be demonstrated on the poster afterwards.

  16. Modelling of Microclimate in collectors

    DEFF Research Database (Denmark)

    Holck, Ole

    1996-01-01

    Abstract It is important to avoid condensation in solar collectors, most of all because wetness of the absorber can damage the selective surface and cause corrosion on the absorber plate. During night time the cover of collectors will cool below ambient temperature due to thermal radiation...

  17. Watergy. A moist air solar collector system with an integrated brine circuit for te heating of buildings; Watergy. Ein Feuchtluft-Solarkollektorsystem mit integriertem Solekreislauf zur Gebaeudeheizung

    Energy Technology Data Exchange (ETDEWEB)

    Buchholz, Martin; Buchholz, Reiner; Geyer, Philipp; Schmidt, Marco [Technische Univ. Berlin (Germany). Fachgebiet Gebaeudetechnik und Entwerfen

    2010-07-01

    Due to the Renewable Energy Law 2009, the proportion of renewable energies in the overall energy consumption of the European Union increased to 20 %. Currently, the proportion of the total heat energy consumption in Germany amounts nearly 40 %. Previous concepts for the storage of heat in the summer for use in winter are not convincing. The improvement of the efficiency of solar collectors and an increase in the collector surface result in increased investment costs and costs for heat supply. Thus, solar collector systems should be optimized for the operation of heaters. This is done for example by reducing the mean collector temperature using a combination of solar collectors with a heat pump. However, heat pumps are operated by means of electrical energy. Electrical energy can not be saved in the summer in order to be used in the winter. Under this aspect, the authors of the contribution under consideration report on the Watergy concept - a moist air solar collector system with an integrated brine circuit for heating of buildings.

  18. An economic optimization of evaporator and air collector area in a solar assisted heat pump drying system

    International Nuclear Information System (INIS)

    Rahman, S.M.A.; Saidur, R.; Hawlader, M.N.A.

    2013-01-01

    Highlights: • The optimum combination will provide around 89% of the total load. • The system has a savings during the life cycle with least payback period of 4.37 year. • The optimal system is insensitive to the variation in fuel inflation and discount rate. - Abstract: This paper presents an economic optimization of evaporator and air collector area of a solar assisted heat pump drying system. Economic viability of solar heating systems is usually made by comparing the cost flows recurring throughout the lifetime of the solar and conventional alternative systems. Therefore, identification of optimum variables by using a simulation program and an economic analysis based on payback period of the system are presented in this paper. FORTRAN language is used to run the simulation. Effect of load and different economic variables on payback period is also investigated. Economic analysis reveals that system has sufficient amount of savings during the life cycle with a minimum payback period of about 4 years

  19. Compilation of publication and results from project C2: Modelling of microclimates in collectors

    Energy Technology Data Exchange (ETDEWEB)

    Holck, O. [ed.

    1999-08-01

    It is important to avoid condensation in solar collectors, most of all because wetness of the absorber can damage the selective surface and cause corrosion on the absorber plate. During night time the cover of collectors will cool below ambient temperature due to thermal radiation to the cold sky. In climates where the air during night time becomes saturated with humidity (the relative humidity is 100%), condensation will form on the outside and inside of the collector glazing. If too much condensation takes place on the inside of the glazing, it will start to fall off on to the absorber surface. The intent of the present work is improvement of a existing computer model for calculation of microclimates data in collectors. Calculations with the model give insight in the humidity and temperature for artificial or realistic climatic data. This design tool makes it possible to calculate the effect of ventilation and insulation materials. Results from investigation of ventilation rates together with a model of the moisture inside the collector are built into the computer program. It has been found that modelling of the moisture transfer in backside insulation is essential to determine the humidity in the air gap of the collector. The objective is to develop guidelines for solar collector design to achieve the most favourable microclimates condition for materials. As a tool the computer model will be useful to fulfil this. Guidelines for collectors will be essential for manufactures to improve the long-term durability of solar collectors. (au)

  20. Comparison of Air Impaction and Electrostatic Dust Collector Sampling Methods to Assess Airborne Fungal Contamination in Public Buildings.

    Science.gov (United States)

    Normand, Anne-Cécile; Ranque, Stéphane; Cassagne, Carole; Gaudart, Jean; Sallah, Kankoé; Charpin, Denis-André; Piarroux, Renaud

    2016-03-01

    Many ailments can be linked to exposure to indoor airborne fungus. However, obtaining a precise measurement of airborne fungal levels is complicated partly due to indoor air fluctuations and non-standardized techniques. Electrostatic dust collector (EDC) sampling devices have been used to measure a wide range of airborne analytes, including endotoxins, allergens, β-glucans, and microbial DNA in various indoor environments. In contrast, viable mold contamination has only been assessed in highly contaminated environments such as farms and archive buildings. This study aimed to assess the use of EDCs, compared with repeated air-impactor measurements, to assess airborne viable fungal flora in moderately contaminated indoor environments. Indoor airborne fungal flora was cultured from EDCs and daily air-impaction samples collected in an office building and a daycare center. The quantitative fungal measurements obtained using a single EDC significantly correlated with the cumulative measurement of nine daily air impactions. Both methods enabled the assessment of fungal exposure, although a few differences were observed between the detected fungal species and the relative quantity of each species. EDCs were also used over a 32-month period to monitor indoor airborne fungal flora in a hospital office building, which enabled us to assess the impact of outdoor events (e.g. ground excavations) on the fungal flora levels on the indoor environment. In conclusion, EDC-based measurements provided a relatively accurate profile of the viable airborne flora present during a sampling period. In particular, EDCs provided a more representative assessment of fungal levels compared with single air-impactor sampling. The EDC technique is also simpler than performing repetitive air-impaction measures over the course of several consecutive days. EDC is a versatile tool for collecting airborne samples and was efficient for measuring mold levels in indoor environments. © The Author 2015

  1. Optimum tilt angle for flat plate collectors all over the World – A declination dependence formula and comparisons of three solar radiation models

    International Nuclear Information System (INIS)

    Stanciu, Camelia; Stanciu, Dorin

    2014-01-01

    Highlights: • Monthly optimum tilt angle is predicted for North latitudes between 0° and 80°. • From practical considerations, an optimum fixed value all along the year is derived. • Three solar radiation models are compared from the point of view of total incident solar radiation density prediction. - Abstract: The paper presents a theoretical study on the optimum tilt angle for flat plate collectors at different geographical locations and different time moments over a year. The solar radiation density is estimated based on three analysis models, namely Hottel and Woertz model (the simplest), Isotropic diffuse model (Liu and Jordan model) and HDKR model (Hay–Davis–Klucker–Reindl), passing from the simplest to the most complex one. Further, the absorbed solar radiation density is computed and the optimum tilt angle is found for different geographical locations (covering the Globe latitudes). The optimum value for the tilt angle is researched for maximum incident solar radiation and also for maximum absorbed one. The results indicate that the same angle is obtained when looking for maximum incident and for maximum absorbed solar radiation. When comparing the three above mentioned models, different tilt angles are supplied by applying the Hottel and Woertz model and respectively the others two (both of them providing the same angle). Although, the predicted absorbed solar radiation is the same in the summertime for all three models, and probably overestimated by the last model in the springtime. The obtained results give an overview over the whole year operation at different geographical latitudes. When using the Hottel and Woertz model for estimating the incident solar radiation, the optimum tilt angle for a flat plate collector should be computed as simplest as β opt = φ − δ function on the latitude and declination. If a fixed value is easier to be used over a specific operation period, an optimum value is provided by this research. The novelty

  2. A detailed thermal-electrical model of three photovoltaic/thermal (PV/T) hybrid air collectors and photovoltaic (PV) module: Comparative study under Algiers climatic conditions

    International Nuclear Information System (INIS)

    Slimani, Mohamed El Amine; Amirat, Madjid; Kurucz, Ildikó; Bahria, Sofiane; Hamidat, Abderrahmane; Chaouch, Wafa Braham

    2017-01-01

    Highlights: • A detailed thermal and electrical model for PV and PV/T systems has been presented. • The developed numerical model was validated successfully with previously published experimental results. • A comparative study between four solar devices (PV and PV/T systems) was carried out. • The experimental weather conditions of Algiers site are used in the numerical model. • The glazed double-pass photovoltaic/thermal air collector shows the best overall energy efficiency. - Abstract: The thermal photovoltaic hybrid collector is a genuine cogeneration technology; it can produce electricity and heat simultaneously. In this paper, a comparative study is presented between four solar device configurations: photovoltaic module (PV-I), conventional hybrid solar air collector (PV/T-II), glazed hybrid solar air collector (PV/T-III) and glazed double-pass hybrid solar air collector (PV/T-IV). A numerical model is developed and validated through experimental results indicated in the previous literature. The numerical model takes the heat balance equations and different thermal and electrical parameters into account for each configuration included in this study, the energy performances are evaluated with a sample weather data of Algiers site. The numerical results show that the daily average of overall energy efficiency reaches: 29.63%, 51.02%, 69.47% and 74% for the first (PV-I), the second (PV/T-II), the third (PV/T-III) and the fourth (PV/T-IV) configurations respectively. These values are obtained with an air flow of 0.023 kg/s and introducing a sample of experimental weather data collected in Algiers site for a sunny day in summer.

  3. An experimental study on the application of polyalcohol solid-solid phase change materials in solar drying with cross-corrugated solar air collectors

    Science.gov (United States)

    Gao, W. F.; Lin, W. X.; Liu, T.; Li, M.

    2017-11-01

    In this paper, two identical solar driers with the same cross-corrugated solar air collectors and drying chamber were developed, one with phase-change materials (PCMs) and the other without PCMs. These two solar drying systems were tested in typical sunny and cloudy days in Kunming and their thermal performances were analyzed. The experimental results show that the temperature changing is smoother in the collector with the PCMs, which is beneficial for the drying as the useful drying time was prolonged. The same trend was also found in the chamber with the PCMs. The PCMs in solar drying system was found to play a role in temperature regulating. There were several cycles of heat charging-discharging in a cloudy testing day while the temperatures on collectors and in chambers with the polyalcohol PCMs is higher than each phase-change temperature. Nevertheless, there was only one cycle of heat charging-discharging in a sunny testing day. The collector with PCMs has higher daily useful heat gain than the collector without PCMs.

  4. Optimal design and placement of serpentine heat exchangers for indirect heat withdrawal, inside flat plate integrated collector storage solar water heaters (ICSSWH)

    Energy Technology Data Exchange (ETDEWEB)

    Gertzos, K.P.; Caouris, Y.G.; Panidis, T. [Dept. of Mechanical Engineering and Aeronautics, University of Patras, 265 00 Patras (Greece)

    2010-08-15

    Parameters that affect the temperature at which service hot water (SHW) is offered by an immersed tube heat exchanger (HX), inside a flat plate Integrated Collector Storage Solar Water Heater (ICSSWH), are examined numerically, by means of Computational Fluid Dynamics (CFD) analysis. The storage water is not refreshed and serves for heat accumulation. Service hot water is drawn off indirectly, through an immersed serpentine heat exchanger. For the intensification of the heat transfer process, the storage water is agitated by recirculation through a pump, which goes on only when service water flows inside the heat exchanger. Three main factors, which influence the performance, are optimized: The position of the HX relative to tank walls, the HX length and the tube diameter. All three factors are explored so that to maximize the service water outlet temperature. The settling time of the optimum configuration is also computed. Various 3-D CFD models were developed using the FLUENT package. The heat transfer rate between the two circuits of the optimum configuration is maintained at high levels, leading to service water outlet temperatures by 1-7 C lower than tank water temperatures, for the examined SHW flow rates. The settling time is retained at sufficient law values, such as 20 s. The optimal position was found to lay the HX in contact with the front and back walls of the tank, with an optimum inner tube diameter of 16 mm, while an acceptable HX length was found to be about 21.5 m. (author)

  5. An evaluation of the performance of an integrated solar combined cycle plant provided with air-linear parabolic collectors

    International Nuclear Information System (INIS)

    Amelio, Mario; Ferraro, Vittorio; Marinelli, Valerio; Summaria, Antonio

    2014-01-01

    An evaluation of the performance of an innovative solar system integrated in a combined cycle plant is presented, in which the heat transfer fluid flowing in linear parabolic collectors is the same oxidant air that is introduced into the combustion chamber of the plant. This peculiarity allows a great simplification of the plant. There is a 22% saving of fossil fuel results in design conditions and 15.5% on an annual basis, when the plant works at nominal volumetric flow rate in the daily hours. The net average year efficiency is 60.9% against the value of 51.4% of a reference combined cycle plant without solar integration. Moreover, an economic evaluation of the plant is carried out, which shows that the extra-cost of the solar part is recovered in about 5 years. - Highlights: • A model to calculate an innovative ISCCS (Integrated solar Combined Cycle Systems) solar plant is presented. • The plant uses air as heat transfer fluid as well as oxidant in the combustor. • The plant presents a very high thermodynamic efficiency. • The plant is very simple in comparison with existing ISCCS

  6. Simulation of Evacuated Tube Collector and Storage of Hybrid Air-conditioning System

    Directory of Open Access Journals (Sweden)

    Mustafa Ahmed Abdulhussain

    2018-02-01

    Full Text Available The CFD transient simulation of superheating the refrigerant R410 through the heat exchange with the evacuated tube water heating system of the hybrid split air conditioner that is subjected to solar radiation of constant intensity with the contribution of fan accelerated air is performed by the ANSYS-CFX code. The comparison with experimental work showed a minimum percentage error 8% of the predicted refrigerant evaporative heat transfer with storage tank horizontal tubing. In addition, the results denoted high absorption rate for the evacuated tubes, reducing highly reversed heat transmission for the circulated water. 

  7. Potential application of glazed transpired collectors to space heating in cold climates

    International Nuclear Information System (INIS)

    Gao, Lixin; Bai, Hua; Mao, Shufeng

    2014-01-01

    Highlights: • A mathematical model for glazed transpired collectors (GTC) is developed. • Glazing results in optical loss, but it decreases convective heat loss effectively. • Thermal performance of GTC shows considerable improvement on flat-plate collectors. • GTC using recirculated air is applicable to space heating in cold climates. - Abstract: Although unglazed transpired collectors (UTC) succeed in industrial ventilation applications, solar fraction is very low when they are used in space heating in cold climates due to the lower exit air temperature. Considering the potential for glazed transpired collectors (GTC) using recirculated air for space heating applications in cold climates, a mathematical model is developed for predicting the thermal performance of GTC. Simulation results show that although glazing results in optical loss, it could decrease convective heat loss resulted from high crosswind velocities effectively. For a solar radiation of 400 W/m 2 , an ambient temperature of −10 °C, and a suction velocity of 0.01 m/s, the exit air temperature of GTC is higher than that of UTC for crosswind velocities exceeding 3.0 m/s. By comparison with a conventional flat-plate solar air collector operating under the same conditions, the thermal performance of GTC shows a significant improvement. For a five-storey hotel building located in the severe cold climate zone of China, case study shows that the annual solar fraction of the GTC-based solar air heating system is about 20%, which is two times higher than that of the flat-plate collector-based system and nearly nine times higher than that of the UTC-based system respectively. Hence, an enormous amount of energy will be saved with the application of GTC to space heating in cold climates

  8. Performance Study of Solar Air Heater Having Absorber Plate with Half-Perforated Baffles

    OpenAIRE

    Maheshwari, B. K.; Karwa, Rajendra; Gharai, S. K.

    2011-01-01

    The paper presents a detailed mathematical model for performance prediction of a smooth duct solar air heater validated against the experimental results. Experimental study on a solar air heater having absorber plate with half-perforated baffles on the air flow side shows thermal efficiency enhancement of 28%–45% over that of the smooth duct solar air heater, which is attributed to the heat transfer enhancement (of the order of 180%–235%) due to the perforated baffles attached to the absorber...

  9. Experimental analysis of solar thermal integrated MD system for cogeneration of drinking water and hot water for single family villa in dubai using flat plate and evacuated tube solar collectors

    DEFF Research Database (Denmark)

    Asim, Muhammad; Imran, Muhammad; Leung, Michael K.H.

    2017-01-01

    This paper presents the experimental analysis performed on solar thermal integrated membrane distillation (MD) system using flat plate and evacuated tube collectors. The system will be utilized for cogeneration of drinking water and domestic hot water for single family in Dubai comprising of four...... to five members. Experiments have been performed in Ras Al Khaimah Research and Innovation Centre (RAKRIC) facility. The experimental setup has been installed to achieve the required production of 15–25 L/d of drinking water and 250 L/d of hot water for domestic purposes. Experiments have been performed...

  10. Rising hopes for vacuum tube collectors

    Energy Technology Data Exchange (ETDEWEB)

    Godolphin, D.

    1982-06-01

    The performance, feasibility and use of vacuum tube solar collectors for domestic hot water (DHW) systems are discussed. An introduction to the design of vacuum tube collectors is presented and comparisons are made with flat plate collectors in terms of effectiveness in DHW applications and cost. The use of vacuum tube collectors is well established for high temperature use such as process heat and absorption cooling applications; there is considerable debate concerning their use in DHW and these arguments are presented. It is pointed out that the accepted standardized comparison test (ASHRAE 93-77) is apparently biased towards the flat plate collectors in direct comparisons of collector efficiencies. Recent developments among manufacturers with regard to vacuum tube collectors and their thinking (pro and con) are discussed in some detail. Breakage and other problems are pointed out although advocates look ahead to lower costs, higher efficiencies, and broader markets (particularly in DHW). It is concluded by some that flat plate collector technology has reached its peak and that vacuum tube collectors will be very prominent in the future. (MJJ)

  11. Cheap effective thermal solar-energy collectors

    Energy Technology Data Exchange (ETDEWEB)

    Highgate, D.J.; Probert, S.D. [Cranfield University, Bedford (United Kingdom). Dept. of Applied Energy

    1996-04-01

    A light-weight flexible solar-collector, with a wavelength-selective absorption surface and an insolation-transparent thermal-insulation protecter for its aperture, was built and tested. Its cheapness and high performance, relative to a conventional flat-plate solar-collector, provide a prima-facie case for the more widespread adoption of its design. (author)

  12. AEROSOL PARTICLE COLLECTOR DESIGN STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S; Richard Dimenna, R

    2007-09-27

    A computational evaluation of a particle collector design was performed to evaluate the behavior of aerosol particles in a fast flowing gas stream. The objective of the work was to improve the collection efficiency of the device while maintaining a minimum specified air throughput, nominal collector size, and minimal power requirements. The impact of a range of parameters was considered subject to constraints on gas flow rate, overall collector dimensions, and power limitations. Potential improvements were identified, some of which have already been implemented. Other more complex changes were identified and are described here for further consideration. In addition, fruitful areas for further study are proposed.

  13. Four-collector flux sensor

    International Nuclear Information System (INIS)

    Wiegand, W.J. Jr.; Bullis, R.H.; Mongeon, R.J.

    1980-01-01

    A flowmeter based on ion drift techniques was developed for measuring the rate of flow of a fluid through a given cross-section. Ion collectors are positioned on each side of an immediately adjacent to ion source. When air flows axially through the region in which ions are produced and appropriate electric fields are maintained between the collectors, an electric current flows to each collector due to the net motion of the ions. The electric currents and voltages and other parameters which define the flow are combined in an electric circuit so that the flux of the fluid can be determined. (DN)

  14. Development of a Solar Assisted Drying System Using Double-Pass Solar Collector with Finned Absorber

    Science.gov (United States)

    Azmi, M. S. M.; Othman, M. Y.; Sopian, K.; Ruslan, M. H.; Majid, Z. A. A.; Fudholi, A.; Yasin, J. M.

    2012-09-01

    The Solar Energy Research Group, Universiti Kebangsaan Malaysia, International Islamic University Malaysia and Yayasan FELDA has designed and constructed a solar assisted drying system at OPF FELDA Factory, Felda Bukit Sagu 2, Kuantan, Pahang. The drying system has a total of six double-pass solar collectors. Each collector has a length of 480 cm and a width of 120 cm. The first channel depth is 3.5 cm and the second channel depth is 7 cm. Longitudinal fins made of angle aluminium, 0.8 mm thickness were attached to the bottom surface of the absorber plate. The solar collectors are arranged as two banks of three collectors each in series. Internal manifold are used to connect the collectors. Air enters through the first channel and then through the second channel of the collector. An auxiliary heater source is installed to supply heat under unfavourable solar radiation condition. An on/off controller is used to control the startup and shutdown of the auxiliary heater. An outlet temperature of 70-75 °C can be achieved at solar radiation range of 800-900 W/m2 and flow rate of 0.12 kg/s. The average thermal efficiency of a solar collector is approximately 37%.

  15. Development of a Solar Assisted Drying System Using Double-Pass Solar Collector with Finned Absorber

    International Nuclear Information System (INIS)

    Azmi, M S M; Sopian, K; Ruslan, M H; Fudholi, A; Majid, Z A A; Yasin, J M; Othman, M Y

    2012-01-01

    The Solar Energy Research Group, Universiti Kebangsaan Malaysia, International Islamic University Malaysia and Yayasan FELDA has designed and constructed a solar assisted drying system at OPF FELDA Factory, Felda Bukit Sagu 2, Kuantan, Pahang. The drying system has a total of six double-pass solar collectors. Each collector has a length of 480 cm and a width of 120 cm. The first channel depth is 3.5 cm and the second channel depth is 7 cm. Longitudinal fins made of angle aluminium, 0.8 mm thickness were attached to the bottom surface of the absorber plate. The solar collectors are arranged as two banks of three collectors each in series. Internal manifold are used to connect the collectors. Air enters through the first channel and then through the second channel of the collector. An auxiliary heater source is installed to supply heat under unfavourable solar radiation condition. An on/off controller is used to control the startup and shutdown of the auxiliary heater. An outlet temperature of 70–75 °C can be achieved at solar radiation range of 800–900 W/m 2 and flow rate of 0.12 kg/s. The average thermal efficiency of a solar collector is approximately 37%.

  16. Theory and design of heat exchanger : air cooled plate, spiral heat exchanger

    International Nuclear Information System (INIS)

    Min, Ui Dong

    1960-02-01

    This book deals with air cooled heat exchanger, which introduces heat rejection system, wet surface cooler in new from, explanation of structure and design, materials, basic design like plenums chambers and fan ring, finned tube fouling factor, airflow in forced draft and fan design. It also tells of plate heat exchanger and spiral heat exchanger giving descriptions of summary, selection, basic design, device and safety function, maintenance, structure of plate heat exchanger, frames and connector plate and, basic things of spiral tube heat exchanger.

  17. Analysis of the thermal performance of a solar heating system using a collector with absorbing surface in plates coated with PVC; Analise do desempenho termico de um sistema de aquecimento solar utilizando coletor com superficie absorvedora em chapas de forro de PVC

    Energy Technology Data Exchange (ETDEWEB)

    Reis, Edmilson Pedreira dos

    2009-08-15

    It is presented a solar collector to be used in a system for heating bath water, whose main characteristic is its low cost. The collector consists of five plates of PVC with 10 mm thick, 200 mm wide and 1400 mm length, with ao area equal to 1,4 square meters. The plates were connected in parallel to the ends of PVC tubes of 40 mm diameter and 32 mm diameter. The plates were coated on one side with aluminum sheets of soft drinks and beers cans open. The system worked on a thermosyphon and was tested in two configurations: the plates uncoated and coated with aluminum material, to determine the influence of material on the efficiency of the collector. For both configurations was used EPS plates below the surface to minimize heat losses from the bottom. The thermal reservoir of the heating system is, also, alternative and of low cost, since it was constructed from a polyethylene tank for storing water, with volume of 150 end 200 liters. It will be presented the thermal efficiency, heat loss, water temperature of the thermal reservoir at the end of the process and simulation of baths for a house with four residents. It will be demonstrated the thermal, economic and material viability of the proposed collector, whose main innovation is the use of recyclable materials, cans of beer and soft drinks, to increase the temperature of the absorber plate. (author)

  18. Standardized performance tests of collectors of solar thermal energy: A selectively coated, steel collector with one transparent cover

    Science.gov (United States)

    1976-01-01

    Basic test results are presented of a flat-plate solar collector whose performance was determined in solar simulator. The collector was tested over ranges of inlet temperatures, fluxes and coolant flow rates. Collector efficiency was correlated in terms of inlet temperature and flux level.

  19. Standardized performance tests of collectors of solar thermal energy: An evacuated flatplate copper collector with a serpentine flow distribution

    Science.gov (United States)

    Johnson, S. M.

    1976-01-01

    Basic test results are given for a flat plate solar collector whose performance was determined in the NASA-Lewis solar simulator. The collector was tested over ranges of inlet temperatures, fluxes and one coolant flow rate. Collector efficiency is correlated in terms of inlet temperature and flux level.

  20. Comparison of three different collectors for process heat applications

    Science.gov (United States)

    Brunold, Stefan; Frey, R.; Frei, Ulrich

    1994-09-01

    In general vacuum tube collectors are used in solar process heat systems. Another possibility is to use transparent insulated flat plate collectors. A critical point however, is that most of the common transparent insulating materials can not withstand high temperatures because they consist of plastics. Thus, temperature resistive collector covers combining a high tranmisivity with a low U-value are required. One possibility is to use capillaries made of glass instead of plastics. Measurement results of collector efficiency and incident angle modifier will be presented as well as calculated energy gains for three different collectors: a vacuum tube collector (Giordano Ind., France), a CPC vacuum tube collector (microtherm Energietechnik Germany; a new flat plate collector using glass capillary as transparent insulation (SET, Germany).

  1. Double-pass photovoltaic / thermal (PV/T) solar collector with advanced heat transfer features

    International Nuclear Information System (INIS)

    Mohd Nazari Abu Bakar; Baharudin Yatim; Mohd Yusof Othman; Kamaruzzaman Sopian

    2006-01-01

    The use of PV/T in combination with concentrating reflectors has a potential to significantly increase power production from a given solar cell area. A prototype double-pass photovoltaic-thermal solar air collector with CPR and fins has been designed and fabricated and its performance over a range of operating conditions was studied. The absorber of the hybrid photovoltaic / thermal (PV/T) collector under investigation consists of an array of solar cells for generating electricity, compound parabolic concentrator (CPR) to increase the radiation intensity falling on the solar cells and fins attached to the back side of the absorber plate to improve heat transfer to the flowing air. The thermal, electrical and combined electrical and thermal efficiencies of the collector are presented and discussed

  2. Magnetic collectors

    International Nuclear Information System (INIS)

    Frew, J.D.

    1980-01-01

    A collector for use in a magnetic separator is formed by isostatically pressing a metal which is resistant to attack by acid about ferromagnetic bodies whereby to encase the bodies in the metal. In one arrangement, as shown, the bodies are encapsulated between inner and outer cylinders. In other arrangements the encapsulating metal is in the form of a tube or planar sheets. The bodies are of Fe or an oxide thereof and the acid-resistant metal parts may be of stainless steel, Au, Pt, Pa or an alloy. The magnetic separator is intended for use in removing particles from liquids during the reprocessing of nuclear fuel materials. (author)

  3. Presence and absence of a water film between moving air bubbles and a plate

    International Nuclear Information System (INIS)

    Remenyik, C.J.

    1990-01-01

    The thickness of water films between an inclined Lucite plate submerged in water and air bubbles moving beneath it was measured with a small impedance probe. The instrument was calibrated with a laser interferometer built for this purpose. The bubbles released beneath the plate varied in size from 10 cc to 100 cc. At a plate inclination angle of 0.98 degree, and in tap water, an uninterrupted water film covered most of the bubbles. Some bubbles, however, dewetted the plate, and the water film covered only a forward part of the bubble. When the film was uninterrupted, its thickness was very uniform from front to rear. When the bubble dewetted the plate, a large forward section of the film had the same uniform thickness, but this was followed by a hump on the film the rear slope of which ended at the plate surface. For some of the experiments, the surface tension of the water was reduced by admixing a detergent. In these experiments, dewetting was not observed. In a second set of experiments, a hand held transparent container filled with water and a 1.3 cm3 air bubble was used to observe visually the behavior of the moving bubble and its associated water film

  4. Structural Response of Submerged Air-Backed Plates by Experimental and Numerical Analyses

    Directory of Open Access Journals (Sweden)

    Lloyd Hammond

    2000-01-01

    Full Text Available This paper presents the results of a series of small-scale underwater shock experiments that measured the structural responses of submerged, fully clamped, air-backed, steel plates to a range of high explosive charge sizes. The experimental results were subsequently used to validate a series of simulations using the coupled LS-DYNA/USA finite element/boundary element codes. The modelling exercise was complicated by a significant amount of local cavitation occurring in the fluid adjacent to the plate and difficulties in modelling the boundary conditions of the test plates. The finite element model results satisfactorily predicted the displacement-time history of the plate over a range of shock loadings although a less satisfactory correlation was achieved for the peak velocities. It is expected that the predictive capability of the finite element model will be significantly improved once hydrostatic initialisation can be fully utilised with the LS-DYNA/USA software.

  5. ADVANCED HYBRID PARTICULATE COLLECTOR

    Energy Technology Data Exchange (ETDEWEB)

    Ye Zhuang; Stanley J. Miller; Michelle R. Olderbak; Rich Gebert

    2001-12-01

    caused by electrical effects. Subsequently, extensive theoretical, bench-scale, and pilot-scale investigations were completed to find an approach to prevent bag damage without compromising AHPC performance. Results showed that the best bag protection and AHPC performance were achieved by using a perforated plate installed between the discharge electrodes and bags. This perforated-plate design was then installed in the 2.5-MW AHPC at Big Stone Power Plant in Big Stone City, South Dakota, and the AHPC was operated from March to June 2001. Results showed that the perforated-plate design solved the bag damage problem and offered even better AHPC performance than the previous design. All of the AHPC performance goals were met, including ultrahigh collection efficiency, high air-to-cloth ratio, reasonable pressure drop, and long bag-cleaning interval.

  6. Entropy generation and thermodynamic analysis of solar air heaters with artificial roughness on absorber plate

    Directory of Open Access Journals (Sweden)

    Prasad Radha K.

    2017-09-01

    Full Text Available This paper presents mathematical modelling and numerical analysis to evaluate entropy generation analysis (EGA by considering pressure drop and second law efficiency based on thermodynamics for forced convection heat transfer in rectangular duct of a solar air heater with wire as artificial roughness in the form of arc shape geometry on the absorber plate. The investigation includes evaluations of entropy generation, entropy generation number, Bejan number and irreversibilities of roughened as well as smooth absorber plate solar air heaters to compare the relative performances. Furthermore, effects of various roughness parameters and operating parameters on entropy generation have also been investigated. Entropy generation and irreversibilities (exergy destroyed has its minimum value at relative roughness height of 0.0422 and relative angle of attack of 0.33, which leads to the maximum exergetic efficiency. Entropy generation and exergy based analyses can be adopted for the evaluation of the overall performance of solar air heaters.

  7. An improved model to evaluate thermodynamic solar plants with cylindrical parabolic collectors and air turbine engines in open Joule–Brayton cycle

    International Nuclear Information System (INIS)

    Ferraro, Vittorio; Imineo, Francesco; Marinelli, Valerio

    2013-01-01

    An improved model to analyze the performance of solar plants operating with cylindrical parabolic collectors and atmospheric air as heat transfer fluid in an open Joule–Brayton cycle is presented. In the new model, the effect of the incident angle modifier is included, to take into account the variation of the optical efficiency with the incidence angle of the irradiance, and the effect of the reheating of the fluid also has been studied. The analysis was made for two operating modes of the plants: with variable air flow rate and constant inlet temperature to the turbine and with constant flow rate and variable inlet temperature to the turbine, with and without reheating of the fluid in the solar field. When reheating is used, the efficiency of the plant is increased. The obtained results show a good performance of this type of solar plant, in spite of its simplicity; it is able to compete well with other more complex plants operating with different heat transfer fluids. - Highlights: ► An improved model to calculate an innovative CPS solar plant is presented. ► The plant works with air in an open Joule–Brayton cycle. ► The reheating of the air increases the thermodynamic efficiency. ► The plant is very simple and competes well with other more complex solar plants

  8. Air-coupled ultrasonic through-transmission thickness measurements of steel plates.

    Science.gov (United States)

    Waag, Grunde; Hoff, Lars; Norli, Petter

    2015-02-01

    Non-destructive ultrasonic testing of steel structures provide valuable information in e.g. inspection of pipes, ships and offshore structures. In many practical applications, contact measurements are cumbersome or not possible, and air-coupled ultrasound can provide a solution. This paper presents air-coupled ultrasonic through-transmission measurements on a steel plate with thicknesses 10.15 mm; 10.0 mm; 9.8 mm. Ultrasound pulses were transmitted from a piezoelectric transducer at normal incidence, through the steel plate, and were received at the opposite side. The S1, A2 and A3 modes of the plate are excited, with resonance frequencies that depend on the material properties and the thickness of the plate. The results show that the resonances could be clearly identified after transmission through the steel plate, and that the frequencies of the resonances could be used to distinguish between the three plate thicknesses. The S1-mode resonance was observed to be shifted 10% down compared to a simple plane wave half-wave resonance model, while the A2 and S2 modes were found approximately at the corresponding plane-wave resonance frequencies. A model based on the angular spectrum method was used to predict the response of the through-transmission setup. This model included the finite aperture of the transmitter and receiver, and compressional and shear waves in the solid. The model predicts the frequencies of the observed modes of the plate to within 1%, including the down-shift of the S1-mode. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Enhanced Freshwater Production Using Finned-Plate Air Gap Membrane Distillation (AGMD

    Directory of Open Access Journals (Sweden)

    Perves Bappy Mohammad Jabed

    2017-01-01

    Full Text Available Air Gap membrane distillation (AGMD, a special type of energy efficient membrane distillation process, is a technology for producing freshwater from waste water. Having some benefits over other traditional processes, this method has been able to draw attention of researchers working in the field of freshwater production technologies. In this study, a basic AGMD system with flat coolant plate has been modified using a specially designed channelled coolant plate of portable size to observe its effect over the production rate and performance of the system. Attempt has been made to increase the amount of distillate flux by using the “fin effect” of the channelled coolant plate. A finned plate have been used instead of a flat coolant plate and experiments were conducted to compare the effect. Coolant temperature and feed temperature of the system have been varied from 10°C to 25°C and 40°C to 70°C respectively. Comparing the data, around 50% to 58% distillate enhancement has been observed for channelled coolant plate. Also, it was seen that the enhancement was higher for higher feed temperatures and coolant temperatures. With these findings, a better performing AGMD module has been introduced to mitigate the scarcity of freshwater.

  10. OUT Success Stories: Transpired Solar Collectors

    International Nuclear Information System (INIS)

    Clyne, R.

    2000-01-01

    Transpired solar collectors are a reliable, low-cost technology for preheating building ventilation air. With simple payback periods ranging from 3 to 12 years and an estimated 30-year life span, transpired collector systems offer building owners substantial cost savings

  11. Free-air ionization chamber, FAC-IR-300, designed for medium energy X-ray dosimetry

    International Nuclear Information System (INIS)

    Mohammadi, S.M.; Tavakoli-Anbaran, H.; Zeinali, H.Z.

    2017-01-01

    The primary standard for X-ray photons is based on parallel-plate free-air ionization chamber (FAC). Therefore, the Atomic Energy Organization of Iran (AEOI) is tried to design and build the free-air ionization chamber, FAC-IR-300, for low and medium energy X-ray dosimetry. The main aim of the present work is to investigate specification of the FAC-IR-300 ionization chamber and design it. FAC-IR-300 dosimeter is composed of two parallel plates, a high voltage (HV) plate and a collector plate, along with a guard electrode that surrounds the collector plate. The guard plate and the collector were separated by an air gap. For obtaining uniformity in the electric field distribution, a group of guard strips was used around the ionization chamber. These characterizations involve determining the exact dimensions of the ionization chamber by using Monte Carlo simulation and introducing correction factors.

  12. Interaction between bubble and air-backed plate with circular hole

    Science.gov (United States)

    Liu, Y. L.; Wang, S. P.; Zhang, A. M.

    2016-06-01

    This paper investigates the nonlinear interaction between a violent bubble and an air-backed plate with a circular hole. A numerical model is established using the incompressible potential theory coupled with the boundary integral method. A double-node technique is used to solve the overdetermined problem caused by the intersection between the solid wall and the free surface. A spark-generated bubble near the air-backed plate with a circular hole is observed experimentally using a high-speed camera. Our numerical results agree well with the experimental results. Both experimental and numerical results show that a multilevel spike emerges during the bubble's expansion and contraction. Careful numerical simulation reveals that this special type of spike is caused by the discontinuity in the boundary condition. The influences of the hole size and depth on the bubble and spike dynamics are also analyzed.

  13. Low-cost solar collectors using thin-film plastics absorbers and glazings

    Energy Technology Data Exchange (ETDEWEB)

    Wilhelm, W.G.

    1980-01-01

    The design, fabrication, performance, cost, and marketing of flat plate solar collectors using plastic absorbers and glazings are described. Manufacturing cost breakdowns are given for single-glazed and double-glazed collectors. (WHK)

  14. Optimization study of a single-effect water–lithium bromide absorption refrigeration system powered by flat-plate collector in hot regions

    International Nuclear Information System (INIS)

    Saleh, A.; Mosa, M.

    2014-01-01

    Highlights: • A comprehensive analysis for optimizing solar absorption system in hot region. • The most important parameter to be controlled is hot source temperature. • Ensuring appropriate choice of parameters, COP of absorption unit exceeds 0.8. • Results show that solar cooling systems are promising in hot regions. • The research aims to play a vital role to promote the use of renewable energy. - Abstract: This investigation has been carried out to present a comprehensive analysis for optimizing the operation of solar absorption system in hot regions. To optimize performance of the system, the hot source temperature should be controlled in function of incident solar radiation, chilled and cooling water temperatures. With an appropriate control, these external conditions can be monitored to detect and implement the actual optimization conditions. Adopting typical values encountered in hot regions, the overall system performance takes its optimal value at temperatures between 75 and 80 °C. It was found that in designing or selecting solar collector, selective coating type is necessary to produce hot water with potential around 80–90 °C needed to optimize operation of absorption unit. By ensuring an appropriate choice of components temperatures, COP of absorption unit can exceed the value 0.8. Cooling water temperature above 40 °C reduces significantly the performance of the unit which requires, under conditions of extremely high external temperatures, dimensioning and selection of condensers and absorbers that guarantee values less than this limit

  15. Air to air fixed plate enthalpy heat exchanger, performance variation and energy analysis

    Energy Technology Data Exchange (ETDEWEB)

    Nasif, Mohammad Shakir [Universiti Teknologi Petronas, Bandar Seri Iskandar (Malaysia); Alwaked, Rafat [Prince Mohammad Bin Fahd University, Al Khobar (Saudi Arabia); Behnia, Masud [University of Sydney, Sydney (Australia); Morrison, Graham [The University of New South Wales, Sydney (Australia)

    2013-11-15

    The thermal performance of a Z shape enthalpy heat exchanger utilising 70 gsm Kraft paper as the heat and moisture transfer surface has been investigated. Effects of different inlet air humidity ratio conditions on the heat exchanger effectiveness and on the energy recovered by the heat exchanger have been the main focus of this investigation. A typical air conditioning cooling coil which incorporates an enthalpy heat exchanger has been modelled for tropical climate. Under test conditions, results have shown that latent effectiveness and the moisture resistance coefficient have strong dependency on the inlet air humidity ratio. Moreover, the latent effectiveness has been found to be strongly dependent on the moisture resistance coefficient rather than the convective mass transfer coefficient. Finally, annual energy analysis for Singapore weather conditions have also shown that energy recovered under variable inlet air conditions is 15% less than that recovered under constant inlet air conditions for the same heat exchanger.

  16. Performance analysis of solar air heater with jet impingement on corrugated absorber plate

    Directory of Open Access Journals (Sweden)

    Alsanossi M. Aboghrara

    2017-09-01

    Full Text Available This paper deals with the experimental investigation outlet temperature and efficiency, of Solar Air heater (SAH. The experimental test set up designed and fabricated to study the effect of jet impingement on the corrugated absorber plate, through circular jets in a duct flow of solar air heater, and compared with conventional solar air heater on flat plat absorber. Under effect of mass flow rate (ṁ of air and solar radiation on outlet air temperature, and efficiency, are analyzed. Results show the flow jet impingement on corrugated plat absorber is a strong function of heat transfer enhancement. The present investigation concludes that the mass flow rate of air substantially influences the heat transfer on solar air heaters. And the thermal efficiency of proposed design duct is observed almost 14% more as compare to the smooth duct. At solar radiation 500–1000 (W/M2, 308 K ambient temperature and 0.01–0.03 (Kg/S mass flow rate

  17. Performance study of solar air heater duct having absorber plate with V down perforated baffles

    Directory of Open Access Journals (Sweden)

    Sunil Chamoli

    2014-04-01

    Full Text Available This paper presents results of a study of the performance of solar air heaters with V down perforated baffles as roughness on the air flow side of the absorber plate. Investigations have been carried out using a mathematical model to study the effects of ambient conditions, operating and design parameters on effective efficiency of such air heaters. The thermal and effective efficiencies differ only marginally at lower flow rates. With an increase in the flow rate, the difference between the thermal and effective efficiencies increases because of the increase in the pumping power. The results of the study are presented in the form of plots to show the effect of ambient, design and operating conditions on thermal and effective efficiency.

  18. Air-coupled method to investigate the lowest-order antisymmetric Lamb mode in stubbed and air-drilled phononic plates

    Directory of Open Access Journals (Sweden)

    Dongbo Zhang

    2016-08-01

    Full Text Available In this work, we applied a robust and fully air-coupled method to investigate the propagation of the lowest-order antisymmetric Lamb (A0 mode in both a stubbed and an air-drilled phononic-crystal (PC plate. By measuring simply the radiative acoustic waves of A0 mode close to the plate surface, we observed the band gaps for the stubbed PC plate caused by either the local resonance or the Bragg scattering, in frequency ranges in good agreement with theoretical predictions. We measured then the complete band gap of A0 mode for the air-drilled PC plate, in good agreement with the band structures. Finally, we compared the measurements made using the air-coupled method with those obtained by the laser ultrasonic technique.

  19. Air-coupled method to investigate the lowest-order antisymmetric Lamb mode in stubbed and air-drilled phononic plates

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Dongbo; Zhao, Jinfeng, E-mail: jinfeng.zhao@tongji.edu.cn; Li, Libing; Pan, Yongdong; Zhong, Zheng [School of Aerospace Engineering and Applied Mechanics, Tongji University, 100 Zhangwu Road, 200092, Shanghai (China); Bonello, Bernard [CNRS, UMR 7588, Institut des NanoSciences de Paris, F-75005, Paris (France); Wei, Jianxin [State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, 18 Xuefu Road, 102249, Pekin (China)

    2016-08-15

    In this work, we applied a robust and fully air-coupled method to investigate the propagation of the lowest-order antisymmetric Lamb (A{sub 0}) mode in both a stubbed and an air-drilled phononic-crystal (PC) plate. By measuring simply the radiative acoustic waves of A{sub 0} mode close to the plate surface, we observed the band gaps for the stubbed PC plate caused by either the local resonance or the Bragg scattering, in frequency ranges in good agreement with theoretical predictions. We measured then the complete band gap of A{sub 0} mode for the air-drilled PC plate, in good agreement with the band structures. Finally, we compared the measurements made using the air-coupled method with those obtained by the laser ultrasonic technique.

  20. Sensing the facet orientation in silver nano-plates using scanning Kelvin probe microscopy in air

    Energy Technology Data Exchange (ETDEWEB)

    Abdellatif, M.H. [Department of Nanostructures, Istituto Italiano di Tecnologia, via Morego 30, I-16163 Genova (Italy); Physics Department, National Research Center, Elbehoos st., 12622, Dokki, Giza (Egypt); Salerno, M., E-mail: marco.salerno@iit.it [Department of Nanophysics, Istituto Italiano di Tecnologia, via Morego 30, I-16163 Genova (Italy); Polovitsyn, Anatolii [Department of Nanochemistry, Istituto Italiano di Tecnologia, via Morego 30, I-16163 Genova (Italy); Dipartimentodi Fisica, Università di Genova, via Dodecaneso 33, I-16146 Genova (Italy); Marras, Sergio [Department of Nanochemistry, Istituto Italiano di Tecnologia, via Morego 30, I-16163 Genova (Italy); De Angelis, Francesco [Department of Nanostructures, Istituto Italiano di Tecnologia, via Morego 30, I-16163 Genova (Italy)

    2017-05-01

    Highlights: • The surface potential of drop cast nanocrystals was measured by SKPM in ambient air. • The nanocrystal facet work function was derived by theory. • By comparing theory and experiment we distinguished the nanocrystal facets. • Nanocrystal facet control is of practical interest for optoelectronic devices. - Abstract: The work function of nano-materials is important for a full characterization of their electronic properties. Because the band alignment, band bending and electronic noise are very sensitive to work function fluctuations, the dependence of the work function of nano-scale crystals on facet orientation can be a critical issue in optimizing optoelectronic devices based on these materials. We used scanning Kelvin probe microscopy to assess the local work function on samples of silver nano-plates at sub-micrometric spatial resolution. With the appropriate choice of the substrate and based on statistical analysis, it was possible to distinguish the surface potential of the different facets of silver nano-plates even if the measurements were done in ambient conditions without the use of vacuum. A phenomenological model was used to calculate the differences of facet work function of the silver nano-plates and the corresponding shift in Fermi level. This theoretical prediction and the experimentally observed difference in surface potential on the silver nano-plates were in good agreement. Our results show the possibility to sense the nano-crystal facets by appropriate choice of the substrate in ambient conditions.

  1. Hot air impingement on a flat plate using Large Eddy Simulation (LES) technique

    Science.gov (United States)

    Plengsa-ard, C.; Kaewbumrung, M.

    2018-01-01

    Impinging hot gas jets to a flat plate generate very high heat transfer coefficients in the impingement zone. The magnitude of heat transfer prediction near the stagnation point is important and accurate heat flux distribution are needed. This research studies on heat transfer and flow field resulting from a single hot air impinging wall. The simulation is carried out using computational fluid dynamics (CFD) commercial code FLUENT. Large Eddy Simulation (LES) approach with a subgrid-scale Smagorinsky-Lilly model is present. The classical Werner-Wengle wall model is used to compute the predicted results of velocity and temperature near walls. The Smagorinsky constant in the turbulence model is set to 0.1 and is kept constant throughout the investigation. The hot gas jet impingement on the flat plate with a constant surface temperature is chosen to validate the predicted heat flux results with experimental data. The jet Reynolds number is equal to 20,000 and a fixed jet-to-plate spacing of H/D = 2.0. Nusselt number on the impingement surface is calculated. As predicted by the wall model, the instantaneous computed Nusselt number agree fairly well with experimental data. The largest values of calculated Nusselt number are near the stagnation point and decrease monotonically in the wall jet region. Also, the contour plots of instantaneous values of wall heat flux on a flat plate are captured by LES simulation.

  2. Sensing the facet orientation in silver nano-plates using scanning Kelvin probe microscopy in air

    International Nuclear Information System (INIS)

    Abdellatif, M.H.; Salerno, M.; Polovitsyn, Anatolii; Marras, Sergio; De Angelis, Francesco

    2017-01-01

    Highlights: • The surface potential of drop cast nanocrystals was measured by SKPM in ambient air. • The nanocrystal facet work function was derived by theory. • By comparing theory and experiment we distinguished the nanocrystal facets. • Nanocrystal facet control is of practical interest for optoelectronic devices. - Abstract: The work function of nano-materials is important for a full characterization of their electronic properties. Because the band alignment, band bending and electronic noise are very sensitive to work function fluctuations, the dependence of the work function of nano-scale crystals on facet orientation can be a critical issue in optimizing optoelectronic devices based on these materials. We used scanning Kelvin probe microscopy to assess the local work function on samples of silver nano-plates at sub-micrometric spatial resolution. With the appropriate choice of the substrate and based on statistical analysis, it was possible to distinguish the surface potential of the different facets of silver nano-plates even if the measurements were done in ambient conditions without the use of vacuum. A phenomenological model was used to calculate the differences of facet work function of the silver nano-plates and the corresponding shift in Fermi level. This theoretical prediction and the experimentally observed difference in surface potential on the silver nano-plates were in good agreement. Our results show the possibility to sense the nano-crystal facets by appropriate choice of the substrate in ambient conditions.

  3. Auto-ignition of methane-air mixtures flowing along an array of thin catalytic plates

    Science.gov (United States)

    Treviño, C.

    2010-12-01

    In this paper, the heterogeneous ignition of a methane-air mixture flowing along an infinite array of catalytic parallel plates has been studied by inclusion of gas expansion effects and the finite heat conduction on the plates. The system of equations considers the full compressible Navier-Stokes equations coupled with the energy equations of the plates. The gas expansion effects which arise from temperature changes have been considered. The heterogeneous kinetics considers the adsorption and desorption reactions for both reactants. The limits of large and small longitudinal thermal conductance of the plate material are analyzed and the critical conditions for ignition are obtained in closed form. The governing equations are solved numerically using finite differences. The results show that ignition is more easily produced as the longitudinal wall thermal conductance increases, and the effects of the gas expansion on the catalytic ignition process are rather small due to the large value of the activation energy of the desorption reaction of adsorbed oxygen atoms.

  4. Dimensional analysis of detrimental ozone generation by positive wire-to-plate corona discharge in air

    Science.gov (United States)

    Bo, Z.; Chen, J. H.

    2010-02-01

    The dimensional analysis technique is used to formulate a correlation between ozone generation rate and various parameters that are important in the design and operation of positive wire-to-plate corona discharges in indoor air. The dimensionless relation is determined by linear regression analysis based on the results from 36 laboratory-scale experiments. The derived equation is validated by experimental data and a numerical model published in the literature. Applications of such derived equation are illustrated through an example selection of the appropriate set of operating conditions in the design/operation of a photocopier to follow the federal regulations of ozone emission. Finally, a new current-voltage characteristic equation is proposed for positive wire-to-plate corona discharges based on the derived dimensionless equation.

  5. Dimensional analysis of detrimental ozone generation by positive wire-to-plate corona discharge in air

    International Nuclear Information System (INIS)

    Bo, Z; Chen, J H

    2010-01-01

    The dimensional analysis technique is used to formulate a correlation between ozone generation rate and various parameters that are important in the design and operation of positive wire-to-plate corona discharges in indoor air. The dimensionless relation is determined by linear regression analysis based on the results from 36 laboratory-scale experiments. The derived equation is validated by experimental data and a numerical model published in the literature. Applications of such derived equation are illustrated through an example selection of the appropriate set of operating conditions in the design/operation of a photocopier to follow the federal regulations of ozone emission. Finally, a new current-voltage characteristic equation is proposed for positive wire-to-plate corona discharges based on the derived dimensionless equation.

  6. Plate heat exchangers in air conditioning applications. Development of air-coolers, air-heaters and air-conditioning units with low pressure loss. Plattenwaermetauscher in raumlufttechnischen Anlagen. Entwicklung stroemungsoptimierter Luftkuehler, Lufterhitzer und Klimageraete

    Energy Technology Data Exchange (ETDEWEB)

    Bach, H; Diemer, R; Eisenmann, G; Goettling, D; Madjidi, M

    1989-08-01

    To prepare the development of a water to air plate heat exchanger the state of the art, i.e. the technological knowhow and the design basis are given. The concept and ideas are presented which lead to a slightly wavy plate. Furthermore an exemplary design of a plate heat exchanger and an air-conditioning unit is described and finally the application of plate heat exchangers as direct evaporators and the potential icing problems are investigated. Comparing measured and calculated data shows that the performance of plates with plane surfaces can be predicted fairly well by the presented design methods. The performance of plates with strongly wavy surface however has to be measured. Optimization calculations yield to an air gap of slightly over 4 mm. Comparison with an air-conditioning unit demonstrates that the strongest advantage is for the air cooler (one third of the pressure loss) that a new concept of an air-conditioning unit has lower losses in the fan unit and that it does not need an eliminator. This results in half the volume for the new unit, in a pressure drop of 88%, fan power of 90% and fan revolutions of 50%. (orig./GL).

  7. Solar Heating Systems with Evacuated Tubular Solar Collector

    DEFF Research Database (Denmark)

    Qin, Lin; Furbo, Simon

    1998-01-01

    Recently different designed evacuated tubular solar collectors were introduced on the market by different Chinese companies. In the present study, investigations on the performance of four different Chinese evacuated tubular collectors and of solar heating systems using these collectors were...... carried out, employing both laboratory test and theoretical calculations. The collectors were tested in a small solar domestic hot water (SDHW) system in a laboratory test facility under realistic conditions. The yearly thermal performance of solar heating systems with these evacuated tubular collectors......, as well as with normal flat-plate collectors was calculated under Danish weather conditions. It is found that, for small SDHW systems with a combi tank design, an increase of 25% -55% net utilized solar energy can be achieved by using these evacuated tubular collectors instead of normal flat...

  8. Garbage collector interface

    OpenAIRE

    Ive, Anders; Blomdell, Anders; Ekman, Torbjörn; Henriksson, Roger; Nilsson, Anders; Nilsson, Klas; Robertz, Sven

    2002-01-01

    The purpose of the presented garbage collector interface is to provide a universal interface for many different implementations of garbage collectors. This is to simplify the integration and exchange of garbage collectors, but also to support incremental, non-conservative, and thread safe implementations. Due to the complexity of the interface, it is aimed at code generators and preprocessors. Experiences from ongoing implementations indicate that the garbage collector interface successfully ...

  9. Mathematical model and simulation of the hydrodynamic of air-pulsed sieve plate columns

    International Nuclear Information System (INIS)

    Hannappel, J.; Pfeifer, W.; Rathjen, E.

    1979-02-01

    In this work the dynamic flow events in an air pulsed sieve plate column are described by a simulation model. The model consists of a system of differential equations. The pressure built up by the pulsed air is brought to equilibrium with the pressure losses of the oscillating liquid column in the pulsation tube and in the column. In case of definition of the a) column geometry, b) integral holdup of the column, c) density of the participating phases, d) control times of the pulsed air valves, e) pulse repetition frequency and pulsed air reservoir pressure the height of oscillation and hence the intensity of pulsation are calculated. It is shown by a concrete example that 1) the oscillation of the liquid column in the pulsation tube and in the column is sinusoidal in all cases; 2) generation of a defined pulsation is restricted to the range between 0.3 and 3 Hz; 3) the amount of air needed for pulsation depends on the geometry of the column and in the intensity of pulsation. It can be optimized by appropriate selection of the diameter of the pulsation tube. (orig.) [de

  10. Recent progress in terrestrial photovoltaic collector technology

    Science.gov (United States)

    Ferber, R. R.

    1982-01-01

    The U.S. Photovoltaic Research and Development Program has the objective to develop the technology necessary to foster widespread grid-competitive electric power generation by the late 1980s. The flat-plate and the concentrator collector activities form the nucleus of the program. The project is concerned with the refining of silicon, silicon sheet production, solar cell processing and fabrication, encapsulation materials development, and collector design and production. The Large-Area Silicon Sheet Task has the objective to develop and demonstrate the feasibility of several methods for producing large area silicon sheet material suitable for fabricating low-cost, high-efficiency solar cells. It is expected that a variety of economic flat-plate and concentrator collectors will become commercially available for grid-connected applications.

  11. A flat solar collector built from galvanized steel plate, working by thermosyphonic flow, optimized for Mexican conditions; Un colector solar plano construido de lamina de acero galvanizada, operando por flujo termosifonico, optimizado para las condiciones mexicanas

    Energy Technology Data Exchange (ETDEWEB)

    Marroquin de Jesus, A; Olivares Ramirez, J.M.; Ramos Lopez, G.A.; Pless, R.C. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Instituto Politecnico Nacional, Unidad Queretaro (Mexico)]. E-mail: amarroquind@utsjr.edu.mx

    2009-07-15

    Design, construction, and testing of the thermal performance of a flat solar collector for domestic water heating are described. The absorbing plate is built from readily available materials: two sheets of galvanized steel, one of the channelled types, the other one flat, which are joined by electric welding. The absorber is connected to a 198-L thermotank, insulated with polyurethane foam. In terms of receiving surface, the prototype tested here has an area of 1.35 m{sup 2}, about 20% smaller than comparable copper-tube-based collectors offered in the market. Temperature measurements conducted over a 30-day period gave values which were a few degrees lower than the theoretically calculated water temperatures. Momentary thermal efficiency values between 35% and 77% were observed. The water temperature achieved the tank at the end of the day averages 65 degrees Celsius in winter weather conditions in the central Mexican highland. This design of solar water heater is well suited to Mexican conditions, as it makes use of the high local intensity of the solar radiation, and as the channel shape of the ducts minimizes bursting during the rare occurrences of freezing temperatures in the region; it also has the advantage of being manufacturable at low cost from simple materials. [Spanish] Se describe el diseno, construccion y pruebas del desempeno termico de un colector solar plano para calentamiento de agua para uso domestico. La placa absorbedora se construyo de materiales facilmente asequibles: dos placas de acero galvanizado, una del tipo acanalado y la otra plana, unidas mediante soldadura de acero electrico. La placa absorbedora esta conectada a un termotanque con capacidad de 198 L, aislado con espuma de poliuretano. La superficie receptora de este prototipo es de 1.35 m{sup 2}, aproximadamente 20% mas pequena comparado con los colectores, basados en tubos de cobre, ofertados en el mercado. Mediciones de temperatura por un periodo de 30 dias, arrojaron valores

  12. Assessment of Energy, Environmental and Economic Performance of a Solar Desiccant Cooling System with Different Collector Types

    Directory of Open Access Journals (Sweden)

    Giovanni Angrisani

    2014-10-01

    Full Text Available Desiccant-based air handling units can achieve reductions in greenhouse gas emissions and energy savings with respect to conventional air conditioning systems. Benefits are maximized when they interact with renewable energy technologies, such as solar collectors. In this work, experimental tests and data derived from scientific and technical literature are used to implement a model of a solar desiccant cooling system, considering three different collector technologies (air, flat-plate and evacuated collectors. Simulations were then performed to compare the energy, environmental and economic performance of the system with those of a desiccant-based unit where regeneration thermal energy is supplied by a natural gas boiler, and with those of a conventional air-handling unit. The only solution that allows achieving the economic feasibility of the solar desiccant cooling unit consists of 16 m2 of evacuated solar collectors. This is able to obtain, with respect to the reference system, a reduction of primary energy consumption and of the equivalent CO2 emissions of 50.2% and 49.8%, respectively, but with a payback time of 20 years.

  13. Countercurrent air/water and steam/water flow above a perforated plate. Report for October 1978-October 1979

    International Nuclear Information System (INIS)

    Hsieh, C.; Bankoff, S.G.; Tankin, R.S.; Yuen, M.C.

    1980-11-01

    The perforated plate weeping phenomena have been studied in both air/water and steam/cold water systems. The air/water experiment is designed to investigate the effect of geometric factors of the perforated plate on the rate of weeping. A new dimensionless flow rate in the form of H star is suggested. The data obtained are successfully correlated by this H star scaling in the conventional flooding equation. The steam/cold water experiment is concentrated on locating the boundary between weeping and no weeping. The effects of water subcooling, water inlet flow rate, and position of water spray are investigated. Depending on the combination of these factors, several types of weeping were observed. The data obtained at high water spray position can be related to the air/water flooding correlation by replacing the stream flow rate to an effective stream flow rate, which is determined by the mixing efficiency above the plate

  14. Heat transfer from a plate cooled by a water film with countercurrent air flow

    International Nuclear Information System (INIS)

    Ambrosini, W.; Manfredini, A.; Mariotti, F.; Oriolo, F.; Vigni, P.

    1995-01-01

    An experimental program at the University of Pisa provides specific data for the evaluation of heat and mass transfer by falling film evaporation. The problem is addressed primarily because of its relevance to the study of the behavior of passive containment cooling systems in simplified pressurized water reactors. In these plants, after an accident that releases vapor from the primary circuit, the steel containment envelope is cooled either by an ascending stream of air in natural circulation or by the combination of air flow and falling film evaporation. To qualify models for the prediction of the heat transfer capabilities in postulated accident conditions, researchers have built an experimental facility consisting of a flat heated plate with water sprays and a fan to simulate a countercurrent air stream. The range of relevant parameters to be investigated has been determined on the basis of integral calculations performed for the AP600 reactor containment. The facility has enabled the collection of data that confirm the adequacy of the classical heat and mass transfer analogy in predicting evaporation phenomena. Further developments in the research are needed to confirm the first results and to extend the experimental database by considering more subtle aspects of the phenomenon such as the characteristics of surface waviness of the water film and its effect on heat transfer

  15. Development of 12.5 m² Solar Collector Panel for Solar Heating Plants

    DEFF Research Database (Denmark)

    Vejen, Niels Kristian; Furbo, Simon; Shah, Louise Jivan

    2004-01-01

    and large solar heating systems. Based on the theoretical findings a prototype of an improved HT solar collector was built and tested side-by-side with the original HT solar collector. The improved HT collector makes use of a changed insulation material, an absorber with improved absorptance and emittance......Theoretical and experimental investigations have elucidated how different changes in the design of the 12.5 m(2) HT flat-plate solar collector from the Danish company ARCON Solvarme A/S influence the solar collector efficiency and the yearly thermal performance. The collector is designed for medium...

  16. Radiation energy collector

    Energy Technology Data Exchange (ETDEWEB)

    Chao, Bei Tse; Rabl, A

    1977-02-10

    The invention deals with a concentrating solar collector. Collectors of this kind often have considerable natural convection losses which are due, among other facts, to the location of the energy absorber at the outlet with the heated surface of the absorber facing the inlet opening of the collector. According to the invention, the collector is designed in such manner that the absorber is located inside a space in such a way that the radiation emitted by the absorber is reflected back to the absorber with the aid of mirror surfaces. Various designs are described.

  17. Short-Term Solar Collector Power Forecasting

    DEFF Research Database (Denmark)

    Bacher, Peder; Madsen, Henrik; Perers, Bengt

    2011-01-01

    This paper describes a new approach to online forecasting of power output from solar thermal collectors. The method is suited for online forecasting in many applications and in this paper it is applied to predict hourly values of power from a standard single glazed large area flat plate collector...... enabling tracking of changes in the system and in the surrounding conditions, such as decreasing performance due to wear and dirt, and seasonal changes such as leaves on trees. This furthermore facilitates remote monitoring and check of the system....

  18. Air loads on a rigid plate oscillating normal to a fixed surface

    NARCIS (Netherlands)

    Beltman, W.M.; van der Hoogt, Peter; Spiering, R.M.E.J.; Tijdeman, H.

    1997-01-01

    This paper deals with the theoretical and experimental investigation on a rigid, rectangular plate oscillating in the proximity of a fixed surface. The plate is suspended by springs. The airloads generated by the oscillating motion of the plate are determined. Due to the fact that the plate is

  19. Solar collector overheating protection

    NARCIS (Netherlands)

    Slaman, M.J.; Griessen, R.P.

    Prismatic structures in a thermal solar collector are used as overheating protection. Such structures reflect incoming light efficiently back whenever less thermal power is extracted from the solar collector. Maximum thermal power is generated when the prismatic structure is surrounded by a

  20. Flow Regimes of Air-Water Counterflow Through Cross Corrugated Parallel Plates

    Energy Technology Data Exchange (ETDEWEB)

    de Almeida, V.F.

    2000-06-07

    Heretofore unknown flow regimes of air-water counterflow through a pair of transparent vertical parallel cross corrugated plates were observed via high-speed video. Air flows upward driven by pressure gradient and water, downward driven by gravity. The crimp geometry of the corrugations was drawn from typical corrugated sheets used as filling material in modern structured packed towers. Four regimes were featured, namely, rivulet, bicontinuous, flooding fronts, and flooding waves. It is conceivable that the regimes observed might constitute the basis for understanding how gas and liquid phases contend for available space in the interstices of structured packings in packed towers. Flow regime transitions were expressed in terms of liquid load (liquid superficial velocity) and gas flow factor parameters commonly used in pressure drop and capacity curves. We have carefully examined the range of parameters equivalent to the ill-understood high-liquid-flow operation in packed towers. More importantly, our findings should prove valuable in validating improved first-principles modeling of gas-liquid flows in these industrially important devices.

  1. Qualification test and analysis report: solar collectors

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-01

    Test results show that the Owens-Illinois Sunpak/sup TM/ Model SEC 601 air-cooled collector meets the national standards and codes as defined in the Subsystem Performance Specification and Verification Plan of NASA/MSFC Contract NAS8-32259, dated October 28, 1976. The architectural and engineering firm of Smith, Hinchman and Grylls, Detroit, Michigan, acted in the capacity of the independent certification agency. The program calls for the development, fabrication, qualification and delivery of an air-liquid solar collector for solar heating, combined heating and cooling, and/or hot water systems.

  2. Experimental studies of rectangular tube absorber photovoltaic thermal collector with various types of nanofluids under the tropical climate conditions

    International Nuclear Information System (INIS)

    Al-Shamani, Ali Najah; Sopian, K.; Mat, Sohif; Hasan, Husam Abdulrasool; Abed, Azher M.; Ruslan, M.H.

    2016-01-01

    Highlights: • A new rectangular tube as absorber for the PVT solar collector was developed. • Different types of nanofluids (SiO_2, TiO_2 and SiC) evaluated. • η_e_l PVT SiC nanofluid was 13.52% at 1000 W/m"2 and flow rate of 0.17 kg/s. • η_c_o_m_b_i_n_e_d PVT SiC nanofluid was 81.73% at 1000 W/m"2 and flow rate of 0.17 kg/s. - Abstract: The flat plate photovoltaic thermal (PVT) collectors can be classified into the type of working fluids used namely the water based PVT collectors, air based PVT collectors and combination of water/air PVT collectors. However, low thermal conductivity of the working fluids has always been the primary limitation in the development of energy-efficient heat transfer fluids, and higher collector performance. To overcome this limitation, there is a strong motivation to improve the heat transfer of fluids with higher thermal conductivity. This new generation of heat transfer fluids called nanofluids consists of suspended nanoparticles and has higher suspension stability compared to the millimeter or micrometer size nanoparticles. Thus, the heat transfer characteristics will be enhanced by using nanofluids. The PVT collector has been designed, fabricated and tested outdoor under the Malaysia tropical climate conditions. The PVT collector consists of specially designed rectangular tube absorber (stainless steel material, height of 15 mm, width of 25 mm and thickness of 1 mm) attached under the photovoltaic module. The PVT collector was experimentally tested with different types of nanofluids (SiO_2, TiO_2 and SiC). The results indicated that the PVT collector with SiC nanofluid has the highest combined photovoltaic thermal (PVT) efficiency of 81.73% and PVT electrical efficiency of 13.52% with the best overall energy coefficient (COE) of 0.93 has been achieved at a flow rate of 0.170 kg/s and solar irradiance levels of 1000 W/m"2, followed by PVT-TiO_2 nanofluids, PVT-SiO_2 nanofluids, and PVT-water respectively.

  3. Flow Characteristics of Multi-circular Jet Plate in Premix Chamber of Air-Assist Atomizer for Burner System

    Directory of Open Access Journals (Sweden)

    Amirnordin Shahrin Hisham

    2016-01-01

    Full Text Available The flow characteristics of multi-circular jet (MCJ plate in the premix chamber of an atomizer were investigated using Computational Fluid Dynamics. Multiphase volume of fluid behavior inside the chamber was determined via steady simulations. The Eulerian–Eulerian two-fluid approach was used for execution mixing of diesel fuel and air. Spray simulation using the discrete phase with injection was generated from the nozzle hole into the ambient atmosphere. The behavior of three MCJ plates in the premix chamber was studied numerically. Results illustrated that plate open area, Ae, influenced the turbulence inside the chamber. MCJ 3, which had the lowest open area, generated the highest flow velocity and turbulence kinetic energy compared with MCJ 1 and 2. The MCJ plates could increase the turbulence in the premix chamber and contribute to the combustion efficiency.

  4. Heat Pumps With Direct Expansion Solar Collectors

    Science.gov (United States)

    Ito, Sadasuke

    In this paper, the studies of heat pump systems using solar collectors as the evaporators, which have been done so far by reserchers, are reviwed. Usually, a solar collector without any cover is preferable to one with ac over because of the necessity of absorbing heat from the ambient air when the intensity of the solar energy on the collector is not enough. The performance of the collector depends on its area and the intensity of the convective heat transfer on the surface. Fins are fixed on the backside of the collector-surface or on the tube in which the refrigerant flows in order to increase the convective heat transfer. For the purpose of using a heat pump efficiently throughout year, a compressor with variable capacity is applied. The solar assisted heat pump can be used for air conditioning at night during the summer. Only a few groups of people have studied cooling by using solar assisted heat pump systems. In Japan, a kind of system for hot water supply has been produced commercially in a company and a kind of system for air conditioning has been installed in buildings commercially by another company.

  5. A simplified method for evaluating thermal performance of unglazed transpired solar collectors under steady state

    International Nuclear Information System (INIS)

    Wang, Xiaoliang; Lei, Bo; Bi, Haiquan; Yu, Tao

    2017-01-01

    Highlights: • A simplified method for evaluating thermal performance of UTC is developed. • Experiments, numerical simulations, dimensional analysis and data fitting are used. • The correlation of absorber plate temperature for UTC is established. • The empirical correlation of heat exchange effectiveness for UTC is proposed. - Abstract: Due to the advantages of low investment and high energy efficiency, unglazed transpired solar collectors (UTC) have been widely used for heating in buildings. However, it is difficult for designers to quickly evaluate the thermal performance of UTC based on the conventional methods such as experiments and numerical simulations. Therefore, a simple and fast method to determine the thermal performance of UTC is indispensable. The objective of this work is to provide a simplified calculation method to easily evaluate the thermal performance of UTC under steady state. Different parameters are considered in the simplified method, including pitch, perforation diameter, solar radiation, solar absorptivity, approach velocity, ambient air temperature, absorber plate temperature, and so on. Based on existing design parameters and operating conditions, correlations for the absorber plate temperature and the heat exchange effectiveness are developed using dimensional analysis and data fitting, respectively. Results show that the proposed simplified method has a high accuracy and can be employed to evaluate the collector efficiency, the heat exchange effectiveness and the air temperature rise. The proposed method in this paper is beneficial to directly determine design parameters and operating status for UTC.

  6. Thermal Modeling of a Hybrid Thermoelectric Solar Collector with a Compound Parabolic Concentrator

    Science.gov (United States)

    Lertsatitthanakorn, C.; Jamradloedluk, J.; Rungsiyopas, M.

    2013-07-01

    In this study radiant light from the sun is used by a hybrid thermoelectric (TE) solar collector and a compound parabolic concentrator (CPC) to generate electricity and thermal energy. The hybrid TE solar collector system described in this report is composed of transparent glass, an air gap, an absorber plate, TE modules, a heat sink to cool the water, and a storage tank. Incident solar radiation falls on the CPC, which directs and reflects the radiation to heat up the absorber plate, creating a temperature difference across the TE modules. The water, which absorbs heat from the hot TE modules, flows through the heat sink to release its heat. The results show that the electrical power output and the conversion efficiency depend on the temperature difference between the hot and cold sides of the TE modules. A maximum power output of 1.03 W and a conversion efficiency of 0.6% were obtained when the temperature difference was 12°C. The thermal efficiency increased as the water flow rate increased. The maximum thermal efficiency achieved was 43.3%, corresponding to a water flow rate of 0.24 kg/s. These experimental results verify that using a TE solar collector with a CPC to produce both electrical power and thermal energy seems to be feasible. The thermal model and calculation method can be applied for performance prediction.

  7. Optimal nonimaging integrated evacuated solar collector

    Science.gov (United States)

    Garrison, John D.; Duff, W. S.; O'Gallagher, Joseph J.; Winston, Roland

    1993-11-01

    A non imaging integrated evacuated solar collector for solar thermal energy collection is discussed which has the lower portion of the tubular glass vacuum enveloped shaped and inside surface mirrored to optimally concentrate sunlight onto an absorber tube in the vacuum. This design uses vacuum to eliminate heat loss from the absorber surface by conduction and convection of air, soda lime glass for the vacuum envelope material to lower cost, optimal non imaging concentration integrated with the glass vacuum envelope to lower cost and improve solar energy collection, and a selective absorber for the absorbing surface which has high absorptance and low emittance to lower heat loss by radiation and improve energy collection efficiency. This leads to a very low heat loss collector with high optical collection efficiency, which can operate at temperatures up to the order of 250 degree(s)C with good efficiency while being lower in cost than current evacuated solar collectors. Cost estimates are presented which indicate a cost for this solar collector system which can be competitive with the cost of fossil fuel heat energy sources when the collector system is produced in sufficient volume. Non imaging concentration, which reduces cost while improving performance, and which allows efficient solar energy collection without tracking the sun, is a key element in this solar collector design.

  8. Thermo-hydraulic performance of solar air heater having multiple v-shaped rib roughness on absorber plates

    Directory of Open Access Journals (Sweden)

    Dhananjay Kumar

    2018-03-01

    Full Text Available This paper presents the performance analysis of the effect of geometrical parameters having multiple v-shaped rib roughness on the airflow side of the absorber plates. Mathematical approach and solution procedure for the analysis of such a solar air heater has been developed theoretically and MATLAB code generated for the solution of the mathematical equations. The effect of parameters such as flow Reynolds number and Relative roughness height on the thermohydraulic performance have been examined and compared with the conventional flat plate solar air heater. A substantial improvement in thermal efficiency of roughened solar air heater as compared to smooth one due to appreciable enhancement in heat transfer coefficient. The enhancement in heat transfer coefficient is also accompanied by a considerable enhancement in pumping power requirement due to the increase in friction factor.

  9. Usage of hybrid solar collector system in drying technologies of medical plants

    International Nuclear Information System (INIS)

    Čiplienė, Aušra; Novošinskas, Henrikas; Raila, Algirdas; Zvicevičius, Egidijus

    2015-01-01

    Highlights: • Solar radiation energy utilization in drying technologies. • Accumulation of solar radiation energy. • The system comprising two different solar collector types. • Preparation of the drying agent by employing solar radiation energy around the clock. • The energy resources saving technology for medicinal plants’ raw material processing and drying. - Abstract: In the temperate climate zone under natural conditions, medicinal plants drying up to 8–12% moisture content and preparation of the quality medicinal plant’s raw material are complicated tasks. In many cases drying process of medicinal plants raw material, particularly rich in volatile compounds, needs the optimal drying temperatures of 30–45 °C and relative humidity not higher than 50–60%. In Lithuania, located in the northern part of the temperate climate zone, in summer the average temperature of ambient air is 16.1 ± 0.5 °C, and relative humidity is 77.3 ± 1.8%. In order to improve the sorption properties of ambient air, it is heated up to the admissible drying temperature. The experimental dryer was developed comprising two different solar collectors: the air type solar collector with area 12 m 2 for direct heating of the drying agent and the flat-plate type solar collector (8 m 2 ) for accumulation of converted heat energy. The research of motherwort (Leonurus cardiaca L.) drying was carried out in the dryer. It was determined that by combining operation of two different solar collectors, the solar radiation energy for drying agent’s heating could be used continuously around the clock by employing the accumulated energy, in order to compensate the solar irradiance variability and to ensure stability of the drying process. In the daytime the air-type solar collector at an airflow equal to 367 m 3 h −1 , i.e. at comparative flow of the drying agent per ton of dried medicinal plant raw material – 2450 m 3 h −1 , heats the air up to 30 °C when the solar

  10. Determination of hexavalent chromium in exhaled breath condensate and environmental air among chrome plating workers.

    Science.gov (United States)

    Goldoni, Matteo; Caglieri, Andrea; Poli, Diana; Vettori, Maria Vittoria; Corradi, Massimo; Apostoli, Pietro; Mutti, Antonio

    2006-03-15

    Chromium speciation has attracted attention because of the different toxicity of Cr(III), which is considered relatively non-toxic, and Cr(VI), which can cross cell membranes mainly as a chromate anion and has been classified as a class I human carcinogen. The aims of the present study were to measure soluble Cr(VI) levels in environmental samples, to develop a simple method of quantifying Cr(VI) in exhaled breath condensate (EBC), and to follow the kinetics of EBC Cr(VI) in chrome plating workers.Personal air samples were collected from 10 chrome platers; EBC was collected from the same workers immediately after the work shift on Tuesday and before the work shift on the following Wednesday. Environmental and EBC Cr(VI) levels were determined by means of colorimetry and electrothermal absorption atomic spectrometry, respectively.The method of detecting Cr(VI) in environmental air was based on the extraction of the Cr(VI)-diphenylcarbazide (Cr(VI)-DPC) complex in 1-butanol, whereas EBC Cr(VI) was determined using a solvent extraction of Cr(VI) as an ion pair with tetrabutylammonium ion, and subsequent direct determination of the complex (Cr(VI)-DPC) in EBC.Kinetic data showed that airborne Cr(VI) was reduced by 50% in airway lining fluid sampled at the end of exposure and that there was a further 50% reduction after about 15 h. The persistence of Cr(VI) in EBC supports the use of EBC in assessing target tissue levels of Cr(VI).

  11. Determination of hexavalent chromium in exhaled breath condensate and environmental air among chrome plating workers

    International Nuclear Information System (INIS)

    Goldoni, Matteo; Caglieri, Andrea; Poli, Diana; Vettori, Maria Vittoria; Corradi, Massimo; Apostoli, Pietro; Mutti, Antonio

    2006-01-01

    Chromium speciation has attracted attention because of the different toxicity of Cr(III), which is considered relatively non-toxic, and Cr(VI), which can cross cell membranes mainly as a chromate anion and has been classified as a class I human carcinogen. The aims of the present study were to measure soluble Cr(VI) levels in environmental samples, to develop a simple method of quantifying Cr(VI) in exhaled breath condensate (EBC), and to follow the kinetics of EBC Cr(VI) in chrome plating workers. Personal air samples were collected from 10 chrome platers; EBC was collected from the same workers immediately after the work shift on Tuesday and before the work shift on the following Wednesday. Environmental and EBC Cr(VI) levels were determined by means of colorimetry and electrothermal absorption atomic spectrometry, respectively. The method of detecting Cr(VI) in environmental air was based on the extraction of the Cr(VI)-diphenylcarbazide (Cr(VI)-DPC) complex in 1-butanol, whereas EBC Cr(VI) was determined using a solvent extraction of Cr(VI) as an ion pair with tetrabutylammonium ion, and subsequent direct determination of the complex (Cr(VI)-DPC) in EBC. Kinetic data showed that airborne Cr(VI) was reduced by 50% in airway lining fluid sampled at the end of exposure and that there was a further 50% reduction after about 15 h. The persistence of Cr(VI) in EBC supports the use of EBC in assessing target tissue levels of Cr(VI)

  12. Determination of hexavalent chromium in exhaled breath condensate and environmental air among chrome plating workers

    Energy Technology Data Exchange (ETDEWEB)

    Goldoni, Matteo [Laboratory of Industrial Toxicology, Department of Clinical Medicine, Nephrology and Health Sciences, University of Parma, Via Gramsci 14, 43100 Parma (Italy); National Institute of Occupational Safety and Prevention, Research Centre at University of Parma, Parma (Italy); Caglieri, Andrea [Laboratory of Industrial Toxicology, Department of Clinical Medicine, Nephrology and Health Sciences, University of Parma, Via Gramsci 14, 43100 Parma (Italy); Poli, Diana [Laboratory of Industrial Toxicology, Department of Clinical Medicine, Nephrology and Health Sciences, University of Parma, Via Gramsci 14, 43100 Parma (Italy); National Institute of Occupational Safety and Prevention, Research Centre at University of Parma, Parma (Italy); Vettori, Maria Vittoria [Laboratory of Industrial Toxicology, Department of Clinical Medicine, Nephrology and Health Sciences, University of Parma, Via Gramsci 14, 43100 Parma (Italy); National Institute of Occupational Safety and Prevention, Research Centre at University of Parma, Parma (Italy); Corradi, Massimo [Laboratory of Industrial Toxicology, Department of Clinical Medicine, Nephrology and Health Sciences, University of Parma, Via Gramsci 14, 43100 Parma (Italy); National Institute of Occupational Safety and Prevention, Research Centre at University of Parma, Parma (Italy); Apostoli, Pietro [Laboratory of Industrial Hygiene, Department of Experimental and Applied Medicine, University of Brescia (Italy); Mutti, Antonio [Laboratory of Industrial Toxicology, Department of Clinical Medicine, Nephrology and Health Sciences, University of Parma, Via Gramsci 14, 43100 Parma (Italy)]. E-mail: antonio.mutti@unipr.it

    2006-03-15

    Chromium speciation has attracted attention because of the different toxicity of Cr(III), which is considered relatively non-toxic, and Cr(VI), which can cross cell membranes mainly as a chromate anion and has been classified as a class I human carcinogen. The aims of the present study were to measure soluble Cr(VI) levels in environmental samples, to develop a simple method of quantifying Cr(VI) in exhaled breath condensate (EBC), and to follow the kinetics of EBC Cr(VI) in chrome plating workers. Personal air samples were collected from 10 chrome platers; EBC was collected from the same workers immediately after the work shift on Tuesday and before the work shift on the following Wednesday. Environmental and EBC Cr(VI) levels were determined by means of colorimetry and electrothermal absorption atomic spectrometry, respectively. The method of detecting Cr(VI) in environmental air was based on the extraction of the Cr(VI)-diphenylcarbazide (Cr(VI)-DPC) complex in 1-butanol, whereas EBC Cr(VI) was determined using a solvent extraction of Cr(VI) as an ion pair with tetrabutylammonium ion, and subsequent direct determination of the complex (Cr(VI)-DPC) in EBC. Kinetic data showed that airborne Cr(VI) was reduced by 50% in airway lining fluid sampled at the end of exposure and that there was a further 50% reduction after about 15 h. The persistence of Cr(VI) in EBC supports the use of EBC in assessing target tissue levels of Cr(VI)

  13. City sewer collectors biocorrosion

    Science.gov (United States)

    Ksiażek, Mariusz

    2014-12-01

    This paper presents the biocorrosion of city sewer collectors impregnated with special polymer sulphur binders, polymerized sulphur, which is applied as the industrial waste material. The city sewer collectors are settled with a colony of soil bacteria which have corrosive effects on its structure. Chemoautotrophic nitrifying bacteria utilize the residues of halites (carbamide) which migrate in the city sewer collectors, due to the damaged dampproofing of the roadway and produce nitrogen salts. Chemoorganotrophic bacteria utilize the traces of organic substrates and produce a number of organic acids (formic, acetic, propionic, citric, oxalic and other). The activity of microorganisms so enables the origination of primary and secondary salts which affect physical properties of concretes in city sewer collectors unfavourably.

  14. Analytical analysis of solar thermal collector with glass and Fresnel lens glazing

    Science.gov (United States)

    Zulkifle, Idris; Ruslan, Mohd Hafidz Hj; Othman, Mohd Yusof Hj; Ibarahim, Zahari

    2018-04-01

    Solar thermal collector is a system that converts solar radiation to heat. The heat will raise the temperature higher than the ambient temperature. Absorber and glazing are two important components in order to increase the temperature of the collector. The thermal absorber will release heat by convection and as radiation to the surrounding. These losses will be reduced by glazing. Other than that, glazing is beneficial for protecting the collector from dust and water. This study discusses about modelling of solar thermal collector effects of different mass flow rates with different glazing for V-groove flat plate solar collectors. The glazing used was the glass and linear Fresnel lens. Concentration ratio in this modelling was 1.3 for 0.1m solar collector thickness. Results show that solar collectors with linear Fresnel lens has the highest efficiency value of 71.18% compared to solar collectors with glass which has efficiency 54.10% with same operation conditions.

  15. Dry/wet performance of a plate-fin air-cooled heat exchanger with continuous corrugated fins

    International Nuclear Information System (INIS)

    Hauser, S.G.; Kreid, D.K.; Johnson, B.M.

    1981-01-01

    The performance and operating characteristics of a plate-fin heat exchanger in dry/wet or deluge operations was experimentally determined. Development of the deluge heat/mass transfer model continued. The experiments were conducted in a specially-designed wind tunnel at the PNL. Air that was first heated and humidified to specified conditions was circulated at a controlled rate through a 2 ft x 6 ft heat exchanger module. The heat exchanger used in the tests was a wavy surface, plate fin on tube configuration. Hot water was circulated through the tubes at high flow rates to maintain an essentially isothermal condition on the tube side. Deionized water sprayed on the top of the vertically oriented plate fins was collected at the bottom of the core and recirculated. Instrumentation was provided for measurement of flow rates and thermodynamic conditions in the air, in the core circulation water, and in the deluge water. Measurements of the air side pressure drop and heat rejection rate were made as a function of air flow rate, air inlet temperature and humidity, deluge water flow rate, and the core inclination from the vertical. An overall heat transfer coefficient and an effective deluge film convective coefficient was determined. The deluge model, for predicting heat transfer from a wet finned heat exchanger was further developed and refined, and a major extension of the model was formulated that permits simultaneous calculation of both the heat transfer and evaporation rates from the wetted surface. The experiments showed an increase in the heat rejection rate due to wetting, accompanied by a proportional increase in the air side pressure drop. For operation at the same air side pressure drop, the enhancement ratio Q/sub w//Q/sub d/ varied between 2 and 5 for the conditions tested. Thus, the potential enhancement of heat transfer due to wetting can be substantial

  16. Evaluation of initial collector field performance at the Langley Solar Building Test Facility

    Science.gov (United States)

    Boyle, R. J.; Knoll, R. H.; Jensen, R. N.

    1977-01-01

    The thermal performance of the solar collector field for the NASA Langley Solar Building Test Facility is given for October 1976 through January 1977. An 1180 square meter solar collector field with seven collector designs helped to provide hot water for the building heating system and absorption air conditioner. The collectors were arranged in 12 rows with nominally 51 collectors per row. Heat transfer rates for each row are calculated and recorded along with sensor, insolation, and weather data every 5 minutes using a mini-computer. The agreement between the experimental and predicted collector efficiencies was generally within five percentage points.

  17. Optimization of thermal performance of a smooth flat-plate solar air heater using teaching–learning-based optimization algorithm

    Directory of Open Access Journals (Sweden)

    R. Venkata Rao

    2015-12-01

    Full Text Available This paper presents the performance of teaching–learning-based optimization (TLBO algorithm to obtain the optimum set of design and operating parameters for a smooth flat plate solar air heater (SFPSAH. The TLBO algorithm is a recently proposed population-based algorithm, which simulates the teaching–learning process of the classroom. Maximization of thermal efficiency is considered as an objective function for the thermal performance of SFPSAH. The number of glass plates, irradiance, and the Reynolds number are considered as the design parameters and wind velocity, tilt angle, ambient temperature, and emissivity of the plate are considered as the operating parameters to obtain the thermal performance of the SFPSAH using the TLBO algorithm. The computational results have shown that the TLBO algorithm is better or competitive to other optimization algorithms recently reported in the literature for the considered problem.

  18. Performance of double -pass solar collector with CPC and fins for heat transfer enhancement

    Science.gov (United States)

    Alfegi, Ebrahim M. A.; Abosbaia, Alhadi A. S.; Mezughi, Khaled M. A.; Sopian, Kamaruzzaman

    2013-06-01

    The temperature of photovoltaic modules increases when it absorbs solar radiation, causing a decrease in efficiency. This undesirable effect can be partially avoided by applying a heat recovery unit with fluid circulation (air or water) with the photovoltaic module. Such unit is called photovoltaic / thermal collector (pv/t) or hybrid (pv/t). In this unit, photovoltaic cells were pasted directly on the flat plate absorber. An experimental study of a solar air heater with photovoltaic cell located at the absorber with fins and compound parabolic collector for heat transfer enhancement and increasing the number of reflection on the cells have been conducted. The performance of the photovoltaic, thermal, and combined pv/t collector over range of operating conditions and the results was discussed. Results at solar irradiance of 500 W/m2 show that the combined pv/t efficiency is increasing from 37.28 % to 81.41 % at mass flow rates various from 0.029 to 0.436 kg/s.

  19. Performance of double –pass solar collector with CPC and fins for heat transfer enhancement

    International Nuclear Information System (INIS)

    Alfegi, Ebrahim M A; Abosbaia, Alhadi A S; Mezughi, Khaled M A; Sopian, Kamaruzzaman

    2013-01-01

    The temperature of photovoltaic modules increases when it absorbs solar radiation, causing a decrease in efficiency. This undesirable effect can be partially avoided by applying a heat recovery unit with fluid circulation (air or water) with the photovoltaic module. Such unit is called photovoltaic / thermal collector (pv/t) or hybrid (pv/t). In this unit, photovoltaic cells were pasted directly on the flat plate absorber. An experimental study of a solar air heater with photovoltaic cell located at the absorber with fins and compound parabolic collector for heat transfer enhancement and increasing the number of reflection on the cells have been conducted. The performance of the photovoltaic, thermal, and combined pv/t collector over range of operating conditions and the results was discussed. Results at solar irradiance of 500 W/m 2 show that the combined pv/t efficiency is increasing from 37.28 % to 81.41 % at mass flow rates various from 0.029 to 0.436 kg/s.

  20. Evaluation of Solar Air Heater Performance with Artificial Rib Roughness over the Absorber Plate using Finite Element Modelling Analysis

    Science.gov (United States)

    Kumar, K. Ravi; Nikhil Varma, P.; Jagadeesh, N.; Sandeep, J. V.; Cheepu, Muralimohan; Venkateswarlu, D.; Srinivas, B.

    2018-03-01

    Among the different renewable energy resources, solar energy is widely used due to its quantitative intensity factor. Solar air heater is cheap, simple in design and has got wide range of applications. A modest solar air heater has a lower in heat transfer and thermal performance as it has heat transfer coefficient lower in between coated absorber plate and the carrier fluid. This low thermal performance can be reduced to a greater extent by introducing the artificially created roughness over the absorber plate of the solar heater. In the present study, the combination of various geometries and roughness’s on the absorber plate are reported. Methods have been developed and implemented in order to improve the rate of the heat transfer. A comparison is drawn among different geometries to select the most effective absorber plate roughness. For flow analysis k-ω SST model was used and the constant heat flux was taken as 1100 W/m2. The Reynolds number is varied in a range from 3000 to 20000. The variation of different parameters temperature, Nusselt number, turbulence kinetic energy and heat transfer coefficient with Reynolds number were examined and discussed.

  1. Spray and Combustion Characteristics of a Novel Multi-circular Jet Plate in Air-assisted Atomizer

    Directory of Open Access Journals (Sweden)

    Hisham Amirnordin Shahrin

    2017-01-01

    Full Text Available Atomization of liquid fuel in air-assisted atomizer is highly dependent on air mixing, which can be enhanced using turbulent generators, such as multi-circular jet (MCJ plates and swirler. This study aims to determine the effects of novel MCJ plates on the spray and combustion characteristics of an air-assisted atomizer by evaluating spray and flame parameters, such as penetration length, cone angle, and cone area. MCJ 30 and MCJ 45, with inclined jets at 30° and 45°, respectively, were used in the experiment. A swirler was also used for comparison. The spray and flame images were recorded at different equivalence ratios through direct photography and analyzed using image J software. Flame temperature was determined using a thermal infrared camera, and burning chamber and flue gas temperatures were measured using thermocouples. The spray and flame characteristics of MCJ 30 exhibited performance comparable with those of the MCJ 45 and swirler. The integration of turbulence and swirling motion concept into the novel MCJ plates can enhance the mixing formation and thus improve the performance of burner combustion.

  2. ANALYSIS AND MODELING OF SOLAR EVAPORATOR-COLLECTOR

    Directory of Open Access Journals (Sweden)

    Zakaria Mohd. Amin

    2015-11-01

    Full Text Available Solar energy is considered a sustainable resource that poses little to no harmful effects on the environment. The performance of a solar system depends to a great extent on the collector used for the conversion of solar radiant energy to thermal energy. A solar evaporator-collector (SEC is basically an unglazed flat plate collector where refrigerants, such as R134a is used as the working fluid. As the operating temperature of the SEC is very low, it utilizes both solar irradiation and ambient energy leading to a much higher efficiency than the conventional collectors. This capability of SECs to utilize ambient energy also enables the system to operate at night. This type of collector can be locally made and is relatively much cheaper than the conventional collector.   At the National University of Singapore, the evaporator-collector was integrated to a heat pump and the performance was investigated for several thermal applications: (i water heating, (ii drying and (iii desalination. A 2-dimensional transient mathematical model of this system was developed and validated by experimental data. The present study provides a comprehensive study of performance. KEYWORDS: heat pump; evaporator-collector.

  3. Experimental investigation of thermal performance of a double-flow solar air heater having aluminium cans

    Energy Technology Data Exchange (ETDEWEB)

    Ozgen, Filiz; Esen, Mehmet; Esen, Hikmet [Department of Mechanical Education, Faculty of Technical Education, Firat University, 23119 Elazig (Turkey)

    2009-11-15

    This study experimentally investigates a device for inserting an absorbing plate made of aluminium cans into the double-pass channel in a flat-plate solar air heater (SAH). This method substantially improves the collector efficiency by increasing the fluid velocity and enhancing the heat-transfer coefficient between the absorber plate and air. These types of collectors had been designed as a proposal to use aluminium materials to build absorber plates of SAHs at a suitable cost. The collector had been covered with a 4-mm single glass plate, in order to reduce convective loses to the atmosphere. Three different absorber plates had been designed and tested for experimental study. In the first type (Type I), cans had been staggered as zigzag on absorber plate, while in Type II they were arranged in order. Type III is a flat plate (without cans). Experiments had been performed for air mass flow rates of 0.03 kg/s and 0.05 kg/s. The highest efficiency had been obtained for Type I at 0.05 kg/s. Also, comparison between the thermal efficiency of the SAH tested in this study with the ones reported in the literature had been presented, and a good agreement had been found. (author)

  4. A solar energy collector

    Energy Technology Data Exchange (ETDEWEB)

    Vasil' yev, L.L.; Avakyan, Yu.V.; Bogdanov, V.M.; Gagiyan, L.A.; Grakovich, L.P.; Karapetyan, G.S.; Morgun, V.A.

    1984-01-01

    A collector whose primary component is a heating pipe is proposed. The evaporation zone located in the lower half of the heating pipe has an external absorption coating. Chambers that open upward and contain the evaporating fluid are mounted within this region along the top. In order to improve operational reliability of the collector, these chambers are mounted on one coated wall; the area of projection of each of the chambers onto the horizontal plane is greater than the area of the projection of each of the chambers placed above it. The coating may be in the form of photocells; a filter is mounted on the chamber side inside the evaporation zone. The evaporation zone may take the form of a cylinder with a segmented base; the photocells are mounted on a flat section of the lateral surface. The collector may be used to cool the photocells.

  5. The Structure Characteristics and Air Permeability of PA and PES Plain and Plated Knits Influenced of Antimicrobial Treatment Conditions

    Directory of Open Access Journals (Sweden)

    Agne MICKEVIČIENĖ

    2014-09-01

    Full Text Available Textile materials are usually exposed to thermal, physical and mechanical effects during treatment processes. These influence the changes of material dimensions. Designing knitted products it is important to predict direction and rate of dimensions change, because this can affect physical properties such as air permeability of knits. The objective of this research was to investigate the influence of antimicrobial treatment conditions on the structure characteristics, thickness and air permeability of plain and plaited knits. The investigations were carried out with two groups of plain and plated single jersey knits. The face yarns of these groups were cotton, bamboo viscose yarn and polyester (Dacron® thread. 10 tex × 2 textured polyamide (PA and 20 tex textured polyester (PES threads were used as the base threads in plated knits. Knitted samples were treated with antimicrobial material Isys AG and organic-inorganic binder Isys MTX (CHT, Germany. It was established that blank and antimicrobial treated knits changed structure parameters, thickness and air permeability. The changes of structure parameters, thickness and air permeability were more associated with conditions of treatment (temperature, treatment in solution, mechanical action rather than with antimicrobial and sol-gel substances used in treatment. DOI: http://dx.doi.org/10.5755/j01.ms.20.3.3196

  6. Characterization of gold and nickel coating on AISI 304 stainless steel for use in the fabrication of current collector plates for fuel cells; Caracterizacion de recubrimientos de oro y niquel realizados sobre acero inoxidable AISI 304 para su empleo en la fabricacion de placas colectoras de corriente para celdas de combustible

    Energy Technology Data Exchange (ETDEWEB)

    Flores Hernandez, J. Roberto [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)] e-mail: jrflores@iie.org.mx; Aguilar Gama, M. Tulio [UNAM. Facultad de Quimica, Mexico D.F. (Mexico); Cano Castillo, Ulises; Albarran, Lorena [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Olvera, J. Carlos; Orozco, German [CIDETEQ, Pedro Escobedo, Queretaro (Mexico)

    2009-09-15

    Among the different components that compose fuel cell technology (MEA, bipolar plates, seals, etc.) current collector plates play an important role in the good performance of fuel cells, since they collect all of the current generated and distribute it to the external circuit. Therefore, the most important properties that the current collector plates should have are excellent conductivity and good resistance to the corrosive conditions present in the fuel cell. This document presents results obtained during the nickel and gold electrodeposition process on AISI 304 stainless steel and the morphology and thickness of each coating, their adhesion, hardness and conductivity values. Finally, results obtained during some of the electrochemical tests performed on the coatings are shown. [Spanish] De los diferentes componentes que integran la tecnologia de celdas de combustible (MEA's, placas bipolares, sellos, etc.), las placas colectoras de corriente tienen un importante rol en el buen desempeno de la celdas de combustibles, ya que en estas placas se colecta toda la corriente generada y se distribuye al circuito externo. Debido a esto, las propiedades mas importantes que deben tener las placas colectaras de corriente son: excelente conductividad y buena resistencia a las condiciones corrosivas presentes en la celda de combustible. En este documento se presentan los resultados obtenidos en el proceso de electrodeposicion de niquel y oro sobre acero inoxidable AISI 304, asi como la morfologia y el espesor de cada recubrimiento, sus valores de adherencia, dureza y conductividad. Finalmente se muestran tambien los resultados obtenidos de algunas pruebas electroquimicas a los que fueron sometidos los recubrimientos.

  7. Solar collector manufacturing activity, 1990

    International Nuclear Information System (INIS)

    1992-01-01

    The Solar Collector Manufacturing Activity 1990 report prepared by the Energy Information Administration (EIA) presents summary and detailed data provided by domestic manufacturers on shipments of solar thermal collectors and photovoltaic cells and modules. Summary data on solar thermal collector shipments are presented for the period 1974 through 1990. Summary data on photovoltaic cell and module shipments are presented for the period 1982 through 1990. Detailed information for solar thermal collectors and photovoltaic cells and modules are presented for 1990

  8. Solar energy collector

    Science.gov (United States)

    Brin, Raymond L.; Pace, Thomas L.

    1978-01-01

    The invention relates to a solar energy collector comprising solar energy absorbing material within chamber having a transparent wall, solar energy being transmitted through the transparent wall, and efficiently absorbed by the absorbing material, for transfer to a heat transfer fluid. The solar energy absorbing material, of generally foraminous nature, absorbs and transmits the solar energy with improved efficiency.

  9. A Study on the Development of Nonglass Solar Vacuum Tube Collector

    International Nuclear Information System (INIS)

    Oh, Seung Jin

    2008-02-01

    Nature has been providing us energy from the beginning of the world. However human has hardly used it wisely. Solar energy is a kind of renewable energy from the nature. This study has been carried out to study the use of solar energy as it is harnessed in the form of thermal energy. Solar energy is one of the most promising energy resources such as hydrogen, biomass, wind and geothermal energy, because it is clean and inexhaustible. Space heating in buildings can be provided from solar energy by systems that are similar in many respects to water heater systems. By tapping into solar energy, we can not only solve the problem of energy shortage, but also can protect the environment and benefit the human beings. There are currently two types of evacuated tube; a single glass tube and a double glass tube. The former consists of a single glass tube which contains a flat or curved aluminium plate attached to a copper heat pipe or water flow pipe. The latter consists of rows of parallel transparent glass tubes, each of which contains an absorber tube. Evacuated tube collectors introduced above, however, pose some problems as they break rather easily under mechanical stresses. This paper introduces some preliminary results in design and fabrication of a non-glass solar vacuum tube collector in which the thermosyphon(heat pipe)made of copper is used as a heat transfer device. A series of tests have been performed to assess the ability of a non-glass solar vacuum tube collector. The series of experiments are as follows: 1)Vacuum level inside a vacuum tube. 2)Effects of the air remaining inside a vacuum tube on the temperature on the absorber plate. 3)Comparison of a non-glass vacuum solar collector with a single glass evacuated tube(SEIDO 5). Different vacuum levels inside non-glass vacuum tubes were applied to check any leakage or unexpected physical or chemical developments with time. The vacuum level changed from 10 -2 torr to 5torr in 5 days due to air infiltration from

  10. An alpha particle detector based on a GPS mosaic scintillator plate for continuous air monitoring in plutonium handling facilities

    International Nuclear Information System (INIS)

    Kaneko, Junichi H.; Izaki, Kenji; Toui, Kouhei; Shimaoka, Takehiro; Morishita, Yuki; Tsubota, Youichi; Higuchi, Mikio

    2016-01-01

    An alpha particle detector was developed for continuous air monitoring of radioactive contamination in working chambers at plutonium handling facilities. A 5-cm-square Gd 2 Si 2 O 7 :Ce (cerium-doped gadolinium pyro-silicate, GPS:Ce) mosaic scintillator plate for alpha particle measurements was fabricated from GPS single-crystal grains of around 550 μm diameter; the GPS grains were made of a GPS polycrystalline body grown using a top seeded solution method. The scintillator layer thickness was approximately 100 μm. The surface filling rate of the GPS grains was ca. 62%. To suppress the influence of non-uniformity of pulse heights of a photomultiplier tube, a central part of ∅ 40 mm of a 76-mm-diameter photomultiplier tube was used. In addition, 3 mm thick high-transmission glass was used as a substrate of the scintillator plate. The detector achieved energy resolution of 13% for 5.5 MeV alpha particles, detection efficiency of 61% and a radon progeny nuclide reduction ratio of 64.5%. A new alpha particle detector was developed to achieve a high radon progeny nuclide reduction ratio approaching that of a silicon semiconductor detector, with high resistance to electromagnetic noise and corrosion. - Highlights: • An alpha particle detector was developed for continuous air monitoring. • The detector comprises a mosaic scintillator plate and a photomultiplier tube. • A 5-cm-square GPS mosaic scintillator plate was fabricated. • Its respective energy resolution and detection efficiency were 13 and 61%. • The radon progeny nuclide reduction ratio of the developed detector was 64.5%.

  11. A stationary evacuated collector with integrated concentrator

    Energy Technology Data Exchange (ETDEWEB)

    Snail, K.A.; O' Gallagher, J.J.; Winston, R.

    1984-01-01

    A comprehensive set of experimental tests and detailed optical and thermal models are presented for a newly developed solar thermal collector. The new collector has an optical efficiency of 65 per cent and achieves thermal efficiencies of better than 50 per cent at fluid temperatures of 200/sup 0/C without tracking the sun. The simultaneous features of high temperature operation and a fully stationary mount are made possible by combining vacuum insulation, spectrally selective coatings, and nonimaging concentration in a novel way. These 3 design elements are ''integrated'' together in a self containe unit by shaping the outer glass envelope of a conventional evacuated tube into the profile of a nonimaging CPC-type concentrator. This permits the use of a first surface mirror and eliminates the need for second cover glazing. The new collector has been given the name ''Integrated Stationary Evacuated Concentrator'', or ISEC collector. Not only is the peak thermal efficiency of the ISEC comparable to that of commercial tracking parabolic troughs, but projections of the average yearly energy delivery also show competitive performance with a net gain for temperatures below 200/sup 0/C. In addition, the ISEC is less subject to exposure induced degradation and could be mass produced with assembly methods similar to those used with fluorescent lamps. Since no tracking or tilt adjustments are ever required and because its sensitive optical surfaces are protected from the environment, the ISEC collector provides a simple, easily maintained solar thermal collector for the range 100-300/sup 0/C which is suitable for most climates and atmospheric conditions. Potential applications include space heating, air conditioning, and industrial process heat.

  12. Local distribution of wall static pressure and heat transfer on a rough flat plate impinged by a slot air jet

    Science.gov (United States)

    Meda, Adimurthy; Katti, Vadiraj V.

    2017-08-01

    The present work experimentally investigates the local distribution of wall static pressure and the heat transfer coefficient on a rough flat plate impinged by a slot air jet. The experimental parameters include, nozzle-to-plate spacing (Z /D h = 0.5-10.0), axial distance from stagnation point ( x/D h ), size of detached rib ( b = 4-12 mm) and Reynolds number ( Re = 2500-20,000). The wall static pressure on the surface is recorded using a Pitot tube and a differential pressure transmitter. Infrared thermal imaging technique is used to capture the temperature distribution on the target surface. It is observed that, the maximum wall static pressure occurs at the stagnation point ( x/D h = 0) for all nozzle-to-plate spacing ( Z/D h ) and rib dimensions studied. Coefficient of wall static pressure ( C p ) decreases monotonically with x/D h . Sub atmospheric pressure is evident in the detached rib configurations for jet to plate spacing up to 6.0 for all ribs studied. Sub atmospheric region is stronger at Z/D h = 0.5 due to the fluid accelerating under the rib. As nozzle to plate spacing ( Z/D h ) increases, the sub-atmospheric region becomes weak and vanishes gradually. Reasonable enhancement in both C p as well as Nu is observed for the detached rib configuration. Enhancement is found to decrease with the increase in the rib width. The results of the study can be used in optimizing the cooling system design.

  13. Solar collector performance evaluated outdoors at NASA-Lewis Research Center

    Science.gov (United States)

    Vernon, R. W.

    1974-01-01

    The study of solar reflector performance reported is related to a project in which solar collectors are to be provided for the solar heating and cooling system of an office building at NASA's Langley Research Center. The solar collector makes use of a liquid consisting of 50% ethylene glycol and 50% water. A conventional air-liquid heat exchanger is employed. Collector performance and solar insolation data are recorded along with air temperature, wind speed and direction, and relative humidity.

  14. Coleccionistas de objetos históricos, arqueológicos y de ciencias naturales en museos municipales de la provincia de Buenos Aires en la década de 1950 Collectors of historical, archeological, and natural science objects at municipal museums in Buenos Aires province, Argentina, during the 1950s

    Directory of Open Access Journals (Sweden)

    María Alejandra Pupio

    2005-01-01

    Full Text Available En este trabajo se explorarán algunos aspectos ligados al proceso de formación de las colecciones arqueológicas en el contexto de creación y expansión de los museos municipales en la provincia de Buenos Aires en la década de 1950. Las colecciones analizadas surgieron en el ámbito privado, recolectadas por coleccionistas que las cedieron para dar origen a estos museos. Al mismo tiempo que las colecciones se hacían públicas, los coleccionistas se convirtieron en sus responsables en el rol de directores de las nuevas instituciones. En el contexto de estos museos, los coleccionistas establecieron relaciones institucionales que sirvieron para elaborar estrategias comunes para el ingreso, selección y exhibición de las colecciones arqueológicas, conformando redes solidarias, como la descripta aquí, para el sur de la provincia de Buenos Aires.Through reference to the creation and expansion of municipal museums in the province of Buenos Aires during the 1950s, the article explores some aspects of how archeological collections are compiled. The collections under study came from private hands, having been gathered by collectors who relinquished them so these museums could be formed. At the same time that these collections became public, the collectors themselves became responsible for them in the role of directors of the new institutes. Within this context, the collectors established institutional relations that allowed them to devise common strategies concerning the receipt, selection, and exhibition of archeological collections. The result was the shaping of a network of solidarity in the southern part of Buenos Aires province.

  15. Design of the free-air ionization chamber, FAC-IR-150, for X-ray dosimetry

    Science.gov (United States)

    Mohammadi, Seyed Mostafa; Tavakoli-Anbaran, Hossein

    2018-03-01

    The primary standard for X-ray dosimetry is based on the free-air ionization chamber (FAC). Therefore, the Atomic Energy Organization of Iran (AEOI) designed the free-air ionization chamber, FAC-IR-150, for low and medium energy X-ray dosimetry. The purpose of this work is the study of the free-air ionization chamber characteristics and the design of the FAC-IR-150. The FAC-IR-150 dosimeter has two parallel plates, a high voltage plate and a collector plate. A guard electrode surrounds the collector and is separated by an air gap. A group of guard strips is used between up and down electrodes to produce a uniform electric field in all the ion chamber volume. This design involves introducing the correction factors and determining the exact dimensions of the ionization chamber by using Monte Carlo simulation.

  16. Mathematical Modeling of Dual Intake Transparent Transpired Solar Collector

    Directory of Open Access Journals (Sweden)

    Thomas Semenou

    2015-01-01

    Full Text Available Nowadays, in several types of commercial or institutional buildings, a significant rise of transpired solar collectors used to preheat the fresh air of the building can be observed. Nevertheless, when the air mass flow rate is low, the collector efficiency collapses and a large amount of energy remains unused. This paper presents a simple yet effective mathematical model of a transparent transpired solar collector (TTC with dual intake in order to remove stagnation problems in the plenum and ensure a better thermal efficiency and more heat recovery. A thermal model and a pressure loss model were developed. Then, the combined model was validated with experimental data from the Solar Rating and Certification Corporation (SRCC. The results show that the collector efficiency can be up to 70% and even 80% regardless of operating conditions. The temperature gain is able to reach 20°K when the solar irradiation is high.

  17. Investigation of methods to transfer heat from solar liquid-heating collectors to heat storage tanks

    Energy Technology Data Exchange (ETDEWEB)

    de Winter, F.

    1976-01-01

    A number of possible solutions to the problems of corrosion and freezing in flat-plate collectors are listed and discussed briefly. Specific considerations involved in the choice and definition of these solutions are discussed in greater detail. (MHR)

  18. Effect of radiation on convective flow in a tilted solar collector filled ...

    African Journals Online (AJOL)

    user

    International Journal of Engineering, Science and Technology. Vol. 4, No. 4, 2012, pp ... The flat-plate solar collector is commonly used today for the collection of low .... Outside the boundary layer, the amount of energy reflected q is neglected.

  19. Numerical and experimental investigation on a new type of compound parabolic concentrator solar collector

    International Nuclear Information System (INIS)

    Zheng, Wandong; Yang, Lin; Zhang, Huan; You, Shijun; Zhu, Chunguang

    2016-01-01

    Highlights: • A serpentine compound parabolic concentrator solar collector is proposed. • A mathematical model for the new collector is developed and verified by experiments. • The thermal efficiency of the collector can be up to 60.5% during the experiments. • The effects of key parameters on the thermal performance are mathematically studied. - Abstract: In order to improve the thermal efficiency, reduce the heat losses and achieve high freezing resistance of the solar device for space heating in cold regions, a new type of serpentine compound parabolic concentrator solar collector is presented in this paper, which is a combination of a compound parabolic concentrator solar collector and a flat plate solar collector. A detailed mathematical model for the new collector based on the analysis of heat transfer is developed and then solved by the software tool Matlab. The numerical results are compared with the experimental data and the maximum deviation is 8.07%, which shows a good agreement with each other. The experimental results show that the thermal efficiency of the collector can be as high as 60.5%. The model is used to predict the thermal performance of the new collector. The effects of structure and operating parameters on the thermal performance are mathematically discussed. The numerical and experimental results show that the new collector is more suitable to provide low temperature hot water for space heating in cold regions and the mathematical model will be much helpful in the designing and optimizing of the solar collectors.

  20. Solar collector array

    Science.gov (United States)

    Hall, John Champlin; Martins, Guy Lawrence

    2015-09-06

    A method and apparatus for efficient manufacture, assembly and production of solar energy. In one aspect, the apparatus may include a number of modular solar receiver assemblies that may be separately manufactured, assembled and individually inserted into a solar collector array housing shaped to receive a plurality of solar receivers. The housing may include optical elements for focusing light onto the individual receivers, and a circuit for electrically connecting the solar receivers.

  1. Transient analysis of the double pass photovoltaic thermal solar collector

    International Nuclear Information System (INIS)

    Alfegi, Ebrahim M.; Sopian, Kamaruzzaman; Abakr, Yousif A.

    2006-01-01

    A mathematical model of a double pass photovoltaic thermal (PV/T) solar collector is reported in this work. It is composed of five couple unsteady nonlinear partial differential equations which are solved by using Gear implicit numerical scheme. That model was validated against experimental data and was found to accurately predict the temperature of the circulated air as well as the temperature distribution of every static elements in a two-pass PV/T solar collector.(Author)

  2. Performance evaluation of a natural-convection solar air-heater with a rectangular-finned absorber plate

    International Nuclear Information System (INIS)

    Fakoor Pakdaman, M.; Lashkari, A.; Basirat Tabrizi, H.; Hosseini, R.

    2011-01-01

    This paper deals with an experimental investigation to evaluate different thermal characteristics of a natural-convection flat-plate solar air-heater with longitudinal rectangular fins array. Having determined the thermal performance of the system a Nusselt number correlation is presented for such finned duct devices. In the presented empirical model which may have industrial applications, solar radiation and ambient temperature have been considered as independent parameters. Other characteristics of the system such as different dimensionless variables, plates and outflow temperatures, efficiency, and mass flow rate have been empirically modeled based on these variables. The particular difference in this study in comparison with the other similar studies is the presentation of an empirical model for rectangular-finned solar air-heaters. This model proposes design concepts and rules of thumb, and demonstrates the calculations of the design parameters. Based on the order of magnitude analysis, solar radiation has been found to be the main parameter which characterizes the thermal behavior of the system. Besides, exergy analysis has been carried out, and optimum conditions in which the system has the highest performance have been determined.

  3. Performance Analysis of a Thermoelectric Solar Collector Integrated with a Heat Pump

    Science.gov (United States)

    Lertsatitthanakorn, C.; Jamradloedluk, J.; Rungsiyopas, M.; Therdyothin, A.; Soponronnarit, S.

    2013-07-01

    A novel heat pump system is proposed. A thermoelectric solar collector was coupled to a solar-assisted heat pump (TESC-HP) to work as an evaporator. The cooling effect of the system's refrigerant allowed the cold side of the system's thermoelectric modules to work at lower temperature, improving the conversion efficiency. The TESC-HP system mainly consisted of transparent glass, an air gap, an absorber plate that acted as a direct expansion-type collector/evaporator, an R-134a piston-type hermetic compressor, a water-cooled plate-type condenser, thermoelectric modules, and a water storage tank. Test results indicated that the TESC-HP has better coefficient of performance (COP) and conversion efficiency than the separate units. For the meteorological conditions in Mahasarakham, the COP of the TESC-HP system can reach 5.48 when the average temperature of 100 L of water is increased from 28°C to 40°C in 60 min with average ambient temperature of 32.5°C and average solar intensity of 815 W/m2, whereas the conversion efficiency of the TE power generator was around 2.03%.

  4. The effect of coupling a flat-plat collector on the solar still productivity

    International Nuclear Information System (INIS)

    Badran, O. O.; Al-Tahaineh, H. A.

    2006-01-01

    Experimental investigation to study the effect of coupling a flat plate solar collector on the productivity of solar stills was carried out. Other different parameters (i.e. water depth, direction of still, solar radiation) to enhance the productivity were also studied. Single slope solar still with mirrors fixed to its interior sides was coupled with a flat plate collector. It has been found that coupling of a solar collector with a still has increased the productivity by 56%. Also the increase of water depth has decreased the productivity, while the still productivity is found to be proportional to the solar radiation intensity.(Author)

  5. Performance Assessment of a Solar-Assisted Desiccant-Based Air Handling Unit Considering Different Scenarios

    Directory of Open Access Journals (Sweden)

    Giovanni Angrisani

    2016-09-01

    Full Text Available In this paper, three alternative layouts (scenarios of an innovative solar-assisted hybrid desiccant-based air handling unit (AHU are investigated through dynamic simulations. Performance is evaluated with respect to a reference system and compared to those of the innovative plant without modifications. For each scenario, different collector types, surfaces and tilt angles are considered. The effect of the solar thermal energy surplus exploitation for other low-temperature uses is also investigated. The first alternative scenario consists of the recovery of the heat rejected by the condenser of the chiller to pre-heat the regeneration air. The second scenario considers the pre-heating of regeneration air with the warmer regeneration air exiting the desiccant wheel (DW. The last scenario provides pre-cooling of the process air before entering the DW. Results reveal that the plants with evacuated solar collectors (SC can ensure primary energy savings (15%–24% and avoid equivalent CO2 emissions (14%–22%, about 10 percentage points more than those with flat-plate collectors, when the solar thermal energy is used only for air conditioning and the collectors have the best tilt angle. If all of the solar thermal energy is considered, the best results with evacuated tube collectors are approximately 73% in terms of primary energy saving, 71% in terms of avoided equivalent CO2 emissions and a payback period of six years.

  6. EFFICIENCY AND LIFETIME OF SOLAR COLLECTORS FOR SOLAR HEATING PLANTS

    DEFF Research Database (Denmark)

    The 12.5 m² flat plate solar collector HT, today marketed by Arcon Solvarme A/S, has been used in solar heating plants in Scandinavia since 1983. The collector is designed to operate in a temperature interval between 40°C and 90°C. The efficiency of the collector has been strongly improved since...... it was introduced on the market. The paper will present the increase of the efficiency of the collector due to technical improvements since 1983. Further, measurements from the spring of 2009 of the efficiency of two HT collectors, which have been in operation in the solar heating plant Ottrupgaard, Skørping......, Denmark since 1994 with a constant high flow rate and in the solar heating plant Marstal, Denmark since 1996 with a variable flow rate, will be presented. The efficiencies will be compared to the efficiencies of the collectors when they were first installed in the solar heating plants. The measurements...

  7. EFFICIENCY AND LIFETIME OF SOLAR COLLECTORS FOR SOLAR HEATING PLANTS

    DEFF Research Database (Denmark)

    Fan, Jianhua; Chen, Ziqian; Furbo, Simon

    2009-01-01

    The 12.5 m² flat plate solar collector HT, today marketed by Arcon Solvarme A/S, has been used in solar heating plants in Scandinavia since 1983. The collector is designed to operate in a temperature interval between 40°C and 90°C. The efficiency of the collector has been strongly improved since...... it was introduced on the market. The paper will present the increase of the efficiency of the collector due to technical improvements since 1983. Further, measurements from the spring of 2009 of the efficiency of two HT collectors, which have been in operation in the solar heating plant Ottrupgaard, Skørping......, Denmark since 1994 with a constant high flow rate and in the solar heating plant Marstal, Denmark since 1996 with a variable flow rate, will be presented. The efficiencies will be compared to the efficiencies of the collectors when they were first installed in the solar heating plants. The measurements...

  8. The CERN antiproton collector

    International Nuclear Information System (INIS)

    Autin, B.

    1984-01-01

    The Antiproton Collector is a new ring of much larger acceptance than the present accumulator. It is designed to receive 10 8 antiprotons per PS cycle. In order to be compatible with the Antiproton Accumulator, the momentum spread and the emittances are reduced from 6% to 0.2% and from 200 π mm mrad to 25 π mm mrad respectively. In addition to the ring itself, the new target area and the modifications to the stochastic systems of the Antiproton Accumulator are described. (orig.)

  9. Use of an air collector plant for a municipal water house in South Africa; Einsatz einer Luftkollektoranlage fuer ein kommunales Wasserhaus in Suedafrika

    Energy Technology Data Exchange (ETDEWEB)

    Schroepf, Siegfried; Ettl, Rudolf [Grammer Solar GmbH, Amberg (Germany)

    2010-07-01

    A very interesting example of application for solar heating of industrial water and drinking water is the 'Water building project' in Jansenville (South Africa). There, the solarly heated water not only serves for having a shower, but also for washing clothes. The washing performance is increased by warm water. Thus less water is consumed. A major task of the project was to develop a completely self-sufficient and low-maintenance solar air-conditioning which easily and effectively covers the hot water requirement of a building with a high solar fraction. Additionally, the solar heating system supports the building with heat and air during the winter months.

  10. Systematic Study of Separators in Air-Breathing Flat-Plate Microbial Fuel Cells—Part 2: Numerical Modeling

    Directory of Open Access Journals (Sweden)

    Sona Kazemi

    2016-01-01

    Full Text Available The separator plays a key role on the performance of passive air-breathing flat-plate MFCs (FPMFC as it isolates the anaerobic anode from the air-breathing cathode. The goal of the present work was to study the separator characteristics and its effect on the performance of passive air-breathing FPMFCs. This was performed partially through characterization of structure, properties, and performance correlations of eight separators presented in Part 1. Current work (Part 2 presents a numerical model developed based on the mixed potential theory to investigate the sensitivity of the electrode potentials and the power output to the separator characteristics. According to this numerical model, the decreased peak power results from an increase in the mass transfer coefficients of oxygen and ethanol, but mainly increasing mixed potentials at the anode by oxygen crossover. The model also indicates that the peak power is affected by the proton transport number of the separator, which affects the cathode pH. Anode pH, on the other hand, remains constant due to application of phosphate buffer solution as the electrolyte. Also according to this model, the peak power is not sensitive to the resistivity of the separator because of the overshadowing effect of the oxygen crossover.

  11. Sound absorption and transmission through flexible micro-perforated panels backed by an air layer and a thin plate.

    Science.gov (United States)

    Bravo, Teresa; Maury, Cédric; Pinhède, Cédric

    2012-05-01

    This paper describes theoretical and experimental investigations into the sound absorption and transmission properties of micro-perforated panels (MPP) backed by an air cavity and a thin plate. A fully coupled modal approach is proposed to calculate the absorption coefficient and the transmission loss of finite-sized micro-perforated panels-cavity-panel (MPPCP) partitions with conservative boundary conditions. It is validated against infinite partition models and experimental data. A practical methodology is proposed using collocated pressure-velocity sensors to evaluate in an anechoic environment the transmission and absorption properties of conventional MPPCPs. Results show under which conditions edge scattering effects should be accounted for at low frequencies. Coupled mode analysis is also performed and analytical approximations are derived from the resonance frequencies and mode shapes of a flexible MPPCP. It is found that the Helmholtz-type resonance frequency is deduced from the one associated to the rigidly backed MPPCP absorber shifted up by the mass-air mass resonance of the flexible non-perforated double-panel. Moreover, it is shown analytically and experimentally that the absorption mechanisms at the resonances are governed by a large air-frame relative velocity over the MPP surface, with either in-phase or out-of-phase relationships, depending on the MPPCP parameters.

  12. Comparative analyses on dynamic performances of photovoltaic–thermal solar collectors integrated with phase change materials

    International Nuclear Information System (INIS)

    Su, Di; Jia, Yuting; Alva, Guruprasad; Liu, Lingkun; Fang, Guiyin

    2017-01-01

    Highlights: • The dynamic model of photovoltaic–thermal collector with phase change material was developed. • The performances of photovoltaic–thermal collector are performed comparative analyses. • The performances of photovoltaic–thermal collector with phase change material were evaluated. • Upper phase change material mode can improve performances of photovoltaic–thermal collector. - Abstract: The operating conditions (especially temperature) of photovoltaic–thermal solar collectors have significant influence on dynamic performance of the hybrid photovoltaic–thermal solar collectors. Only a small percentage of incoming solar radiation can be converted into electricity, and the rest is converted into heat. This heat leads to a decrease in efficiency of the photovoltaic module. In order to improve the performance of the hybrid photovoltaic–thermal solar collector, we performed comparative analyses on a hybrid photovoltaic–thermal solar collector integrated with phase change material. Electrical and thermal parameters like solar cell temperature, outlet temperature of air, electrical power, thermal power, electrical efficiency, thermal efficiency and overall efficiency are simulated and analyzed to evaluate the dynamic performance of the hybrid photovoltaic–thermal collector. It is found that the position of phase change material layer in the photovoltaic–thermal collector has a significant effect on the performance of the photovoltaic–thermal collector. The results indicate that upper phase change material mode in the photovoltaic–thermal collector can significantly improve the thermal and electrical performance of photovoltaic–thermal collector. It is found that overall efficiency of photovoltaic–thermal collector in ‘upper phase change material’ mode is 10.7% higher than that in ‘no phase change material’ mode. Further, for a photovoltaic–thermal collector with upper phase change material, it is verified that 3 cm

  13. Thermo-ecological optimization of a solar collector

    International Nuclear Information System (INIS)

    Szargut, J.; Stanek, W.

    2007-01-01

    The depletion of non-renewable natural exergy resources (the thermo-ecological cost) has been accepted as the objective function for thermo-ecological optimization. Its general formulation has been cited. A detailed form of the objective function has been formulated for a solar collector producing hot water for household needs. The following design parameters have been accepted as the decision variables: the collector area per unit of the heat demand, the diameter of collector pipes, the distance of the pipe axes in the collector plate. The design parameters of the internal installation (the pipes, the hot water receiver) have not been taken into account, because they are very individual. The accumulation ability of hot water comprising one day has been assumed. The objective function contains the following components: the thermo-ecological cost of copper plate, copper pipes, glass plate, steel box, thermal insulation, heat transfer liquid, electricity for driving the pump of liquid, fuel for the peak boiler. The duration curves of the flux of solar radiation and absorbed heat have been elaborated according to meteorological data and used in the calculations. The objective function for economic optimization may have a similar form, only the cost values would be different

  14. Integrated function nonimaging concentrating collector tubes for solar thermal energy

    Science.gov (United States)

    Winston, R.; Ogallagher, J. J.

    1982-09-01

    A substantial improvement in optical efficiency over contemporary external reflector evacuated tube collectors has been achieved by integrating the reflector surface into the outer glass envelope. Described are the design fabrication and test results for a prototype collector based on this concept. A comprehensive test program to measure performance and operational characteristics of a 2 sq m panel (45 tubes) has been completed. Efficiencies above 50% relative to beam at 200 C have been repeatedly demonstrated. Both the instantaneous and long term average performance of this totally stationary solar collector are comparable to those for tracking line focus parabolic troughs. The yield, reliability and stability of performance achieved have been excellent. Subcomponent assemblies and fabrication procedures have been used which are expected to be compatible with high volume production. The collector has a wide variety of applications in the 100 to 300 C range including industrial progress heat, air conditioning and Rankine engine operation.

  15. Single and double pass solar air heaters with wire mesh as packing bed

    Energy Technology Data Exchange (ETDEWEB)

    Aldabbagh, L.B.Y.; Egelioglu, F. [Mechanical Engineering Department, Eastern Mediterranean University, Magosa, Mersin 10 (Turkey); Ilkan, M. [School of Computing and Tecnology, Eastern Mediterranean University, Magosa, Mersin 10 (Turkey)

    2010-09-15

    The thermal performances of single and double pass solar air heaters with steel wire mesh layers are used instead of a flat absorber plate are investigated experimentally. The effects of mass flow rate of air on the outlet temperature and thermal efficiency were studied. The results indicate that the efficiency increases with increasing the mass flow rate for the range of the flow rate used in this work between 0.012 and 0.038 kg/s. For the same flow rate, the efficiency of the double pass is found to be higher than the single pass by 34-45%. Moreover, the maximum efficiencies obtained for the single and the double pass air collectors are 45.93 and 83.65% respectively for the mass flow rate of 0.038 kg/s. Comparison of the results of a packed bed collector with those of a conventional collector shows a substantial enhancement in the thermal efficiency. (author)

  16. The PKI collector

    Science.gov (United States)

    Rice, M. P.

    1982-07-01

    The design and manufacturing of a solar thermal collector is discussed. The collector has three primary subsystems: concentrator, receiver/fluid loop, and controls. Identical curved reflective columns are utilized in a faceted Fresnel design to support 864 one foot square flat inexpensive second-surface, silvered glass mirrors. The columns are ganged together and rotated through their centers of gravity to provide elevation tracking. The concentrator is supported by a lightweight spaceframe structure which distributes all wind and gravity loads to the base supports. The base of the structure is a track which rotates on wheels mounted on concrete piers. A parallel tube steel heat exchanger is mounted at the concentrator focal area in a well insulated, galvanized steel housing. Two rows of vertical close-packed, staggered tubes connect a mud header and a steam header. Automatic two axis tracking and operational control is provided with a microprocessor based package. Concentrator-mounted shadowbands are the basis for active tracking. A software program provides azimuthal tracking during cloudy periods.

  17. Energy and exergy analyses of Photovoltaic/Thermal flat transpired collectors: Experimental and theoretical study

    International Nuclear Information System (INIS)

    Gholampour, Maysam; Ameri, Mehran

    2016-01-01

    Highlights: • A Photovoltaic/Thermal flat transpired collector was theoretically and experimentally studied. • Performance of PV/Thermal flat transpired plate was evaluated using equivalent thermal, first, and second law efficiencies. • According to the actual exergy gain, a critical radiation level was defined and its effect was investigated. • As an appropriate tool, equivalent thermal efficiency was used to find optimum suction velocity and PV coverage percent. - Abstract: PV/Thermal flat transpired plate is a kind of air-based hybrid Photovoltaic/Thermal (PV/T) system concurrently producing both thermal and electrical energy. In order to develop a predictive model, validate, and investigate the PV/Thermal flat transpired plate capabilities, a prototype was fabricated and tested under outdoor conditions at Shahid Bahonar University of Kerman in Kerman, Iran. In order to develop a mathematical model, correlations for Nusselt numbers for PV panel and transpired plate were derived using CFD technique. Good agreement was obtained between measured and simulated values, with the maximum relative root mean square percent deviation (RMSE) being 9.13% and minimum correlation coefficient (R-squared) 0.92. Based on the critical radiation level defined in terms of the actual exergy gain, it was found that with proper fan and MPPT devices, there is no concern about the critical radiation level. To provide a guideline for designers, using equivalent thermal efficiency as an appropriate tool, optimum values for suction velocity and PV coverage percent under different conditions were obtained.

  18. Parametric Study on the Thermal Performance and Optimal Design Elements of Solar Air Heater Enhanced with Jet Impingement on a Corrugated Absorber Plate

    Directory of Open Access Journals (Sweden)

    Alsanossi M. Aboghrara

    2018-01-01

    Full Text Available Previous works revealed that cross-corrugated absorber plate design and jet impingement on a flat absorber plate resulted in a significant increase in the performance of a solar air heater (SAH. Involving these two designs into one continuous design to improve the SAH performance remains absent in the literature. This study aimed to evaluate the achieved enhancement on performance parameters of a SAH with jet impingement on a corrugated absorber plate. An energy balance model was developed to compare the performance parameters of the proposed SAH with the other two SAHs. At a clear sky day and a mass flow rate of 0.04 kg/s, the hourly results revealed that the max fluid outlet temperatures for the proposed SAH, jet-to-flat plate SAH, and cross-corrugated plate SAH are 321, 317, and 313 K, respectively; the max absorber plate temperatures are 323.5, 326.5, and 328 K, respectively; the maximum temperature differences between the absorber plate and fluid outlet are ~3, 9, and 15 K, respectively; the max efficiencies are 65.7, 64.8, and 60%, respectively. Statistical t-test results confirmed significant differences between the mean efficiency of the proposed SAH and SAH with jet-to-flat plate. Hence, the proposed design is considered superior in improving the performance parameters of SAH compared to other designs.

  19. Numerical Investigation of Laminar Diffusion Flames Established on a Horizontal Flat Plate in a Parallel Air Stream

    Directory of Open Access Journals (Sweden)

    E. D. Gopalakrishnan

    2011-06-01

    Full Text Available Numerical investigation of laminar diffusion flames established on a flat plate in a parallel air stream is presented. A numerical model with a multi-step chemical kinetics mechanism, variable thermo-physical properties, multi-component species diffusion and a radiation sub-model is employed for this purpose. Both upward and downward injection of fuel has been considered in a normal gravity environment. The thermal and aerodynamic structure of the flame has been explained with the help of temperature and species contours, net reaction rate of fuel and streamlines. Flame characteristics and stability aspects for several air and fuel velocity combinations have been studied. An important characteristic of a laminar boundary layer diffusion flame with upward injection of fuel is the velocity overshoot that occurs near the flame zone. This is not observed when the fuel is injected in the downward direction. The flame standoff distance is slightly higher for the downward injection of fuel due to increase in displacement thickness of boundary layer. Influence of an obstacle, namely the backward facing step, on the flame characteristics and stability aspects is also investigated. Effects of air and fuel velocities, size and location of the step are studied in detail. Based on the air and fuel velocities, different types of flames are predicted. The use of a backward-facing step as a flame holding mechanism for upward injection of fuel, results in increased stability limits due to the formation of a recirculation zone behind the step. The predicted stability limits match with experimentally observed limits. The step location is seen to play a more important role as compared to the step height in influencing the stability aspects of flames.

  20. Solar collector wall with active curtain system; Lasikatteinen massiivienen aurinkokeraeaejaeseinae

    Energy Technology Data Exchange (ETDEWEB)

    Ojanen, T.; Heimonen, I. [VTT Building Technology, Espoo (Finland). Building Physics, Building Services and Fire Technology

    1998-12-01

    layer remain low after the solar radiation period. Thus a significant proportion of the solar radiation energy received at the absorption surface can be transferred into the room space. The delay between the solar radiation peak and the heat flow into the room can be optimised by selecting suitable materials and dimensions for the storage layer of the wall. During cold period, when there is high solar radiation to a south facing wall in successive days, the temperature of a one brick thick storage layer remains above the room air temperature throughout the day, and the collector wall operates continually as a heat radiator. (orig.) 14 refs. RAKET Research Programme

  1. LHCb Tag Collector

    International Nuclear Information System (INIS)

    Fernández, Paloma Fuente; Clemencic, Marco; Cousin, Nicolas

    2011-01-01

    The LHCb physics software consists of hundreds of packages, each of which is developed by one or more physicists. When the developers have some code changes that they would like released, they commit them to the version control system, and enter the revision number into a database. These changes have to be integrated into a new release of each of the physics analysis applications. Tests are then performed by a nightly build system, which rebuilds various configurations of the whole software stack and executes a suite of run-time functionality tests. A Tag Collector system has been developed using solid standard technologies to cover both the use cases of developers and integration managers. A simple Web interface, based on an AJAX-like technology, is available. Integration with SVN and Nightly Build System, is possible via a Python API. Data are stored in a relational database with the help of an ORM (Object-Relational Mapping) library.

  2. Advanced evacuated tube collectors

    Science.gov (United States)

    Schertz, W. W.; Hull, J. R.; Winston, R.; Ogallagher, J.

    1985-04-01

    The essence of the design concept for these new collectors is the integration of moderate levels of nonimaging concentration inside the evacuated tube itself. This permanently protects the reflection surfaces and allows the use of highly reflecting front surface mirrors with reflectances greater than 95%. Previous fabrication and long term testing of a proof-of-concept prototype has established the technical success of the concept. Present work is directed toward the development of a manufacturable unit that will be suitable for the widest possible range of applications. Design alternatives include scaling up the original prototype's tube diameter from 5 cm to 10 cm, using an internal shaped metal concentrating reflector, using a variety of profile shapes to minimize so-called gap losses and accommodate both single ended and double-ended flow geometries, and allowing the use of heat pipes for the absorber tube.

  3. Thermal Performance of Solar Air Heater Having Absorber Plate with V-Down Discrete Rib Roughness for Space-Heating Applications

    Directory of Open Access Journals (Sweden)

    Rajendra Karwa

    2013-01-01

    Full Text Available The paper presents results of thermal performance analysis of a solar air heater with v-down discrete rib roughness on the air flow side of the absorber plate, which supplies heated air for space heating applications. The air heater operates in a closed loop mode with inlet air at a fixed temperature of 295 K from the conditional space. The ambient temperature varied from 278 K to 288 K corresponding to the winter season of Western Rajasthan, India. The results of the analysis are presented in the form of performance plots, which can be utilized by a designer for calculating desired air flow rate at different ambient temperature and solar insolation values.

  4. Alternative refrigerants performance in plate heat condenser for air conditioning; Scambiatori compatti per il condizionamento ambientale

    Energy Technology Data Exchange (ETDEWEB)

    Boccardi, G.; Celata, G.P.; Marchesi Donati, F. [ENEA, Rome (Italy). Inst. of Thermal-Fluid Dynamics; Cumo, M. [Rome Univ. La Sapienza, Rome (Italy). Dept. of Nuclear Engineering and Energy Conversion; Gerosa, A. [Rome Univ. Tor Vergata, Rome (Italy). Dept. of Mechanical Engineering; Zorzin, A. [R and D Alfa Laval Artec Spa Vicenza, Vicenza (Italy)

    1999-12-01

    An experimental campaign on plate heat exchangers, used as evaporators and condenser in domestic refrigeration loops is presented in this paper. The research's purpose is to test the influence of some thermal-hydraulic parameters on the global overall heat transfer coefficient. R134a, R407C, R410A, and R22 are the fluids tested under reference thermal conditions. The experimental tests allows one to withdraw conclusions on the substitution effect on the thermal and global efficiency of the plant. Also, a new method for calculating the thermodynamical mixture parameters is applied to the condensation of mixtures R407C and R410A and its benefit evaluated. The refrigerant loop overall performance and the condenser global heat transfer coefficient are the parameters chosen to enlighten the characteristics of the alternative refrigerants (R134a, R407C, and R410A) with respect to the fluid that they are supposed to substitute (R22). [Italian] Scambiatori a piastre compatti impiegati come evaporatori e condensatori nei circuiti frigoriferi, sono l'oggetto della ricerca presentata in questo articolo. L'efficienza termica di tali componenti e' valutata in condizioni di riferimento commerciali. I refrigeranti utilizzati sono tre fluidi proposti per sostituire l'R22, un Hcfc, attualmente il refrigerante piu' utilizzato nel condizionamento ambientale. Una serie di prove condotte con quest'ultimo fluido consente di studiare gli effetti della sostituzione del fluido di progetto sulle prestazioni sia degli scambiatori, sia piu' in generale, dell'intero circuito frigorifero. In particolare sono state studiate le prestazioni di due coppie di evaporatori e condensatori in termini di coefficiente globale di scambio termico e di Cop dell'impianto. Nel presente lavoro e' inoltre presentato e utilizzato un metodo termodinamico per il calcolo della temperatura di saturazione per le miscele zeotropiche in bifase; uno dei refrigeranti

  5. Current collectors for improved safety

    Science.gov (United States)

    Abdelmalak, Michael Naguib; Allu, Srikanth; Dudney, Nancy J.; Li, Jianlin; Simunovic, Srdjan; Wang, Hsin

    2017-12-19

    A battery electrode assembly includes a current collector with conduction barrier regions having a conductive state in which electrical conductivity through the conduction barrier region is permitted, and a safety state in which electrical conductivity through the conduction barrier regions is reduced. The conduction barrier regions change from the conductive state to the safety state when the current collector receives a short-threatening event. An electrode material can be connected to the current collector. The conduction barrier regions can define electrical isolation subregions. A battery is also disclosed, and methods for making the electrode assembly, methods for making a battery, and methods for operating a battery.

  6. Molecular design of flotation collectors: A recent progress.

    Science.gov (United States)

    Liu, Guangyi; Yang, Xianglin; Zhong, Hong

    2017-08-01

    The nature of froth flotation is to selectively hydrophobize valuable minerals by collector adsorption so that the hydrophobized mineral particles can attach air bubbles. In recent years, the increasing commercial production of refractory complex ores has been urgent to develop special collectors for enhancing flotation separation efficiency of valuable minerals from these ores. Molecular design methods offer an effective way for understanding the structure-property relationship of flotation collectors and developing new ones. The conditional stability constant (CSC), molecular mechanics (MM), quantitative structure-activity relationship (QSAR), and first-principle theory, especially density functional theory (DFT), have been adopted to build the criteria for designing flotation collectors. Azole-thiones, guanidines, acyl thioureas and thionocarbamates, amide-hydroxamates, and double minerophilic-group surfactants such as Gemini, dithiourea and dithionocarbamate molecules have been recently developed as high-performance collectors. To design hydrophobic groups, the hydrophilic-hydrophobic balance parameters have been extensively used as criteria. The replacement of aryl group with aliphatic group or CC single bond(s) with CC double bond(s), reduction of carbon numbers, introduction of oxygen atom(s) and addition of trisiloxane to the tail terminal have been proved to be useful approaches for adjusting the surface activity of collectors. The role of molecular design of collectors in practical flotation applications was also summarized. Based on the critical review, some comments and prospects for further research on molecular design of flotation collectors were also presented in the paper. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Water heating solar system using collector with polycarbonate absorber surface

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Luiz Guilherme Meira de; Sodre, Dilton; Cavalcanti, Eduardo Jose Cidade; Souza, Luiz Guilherme Vieira Meira de; Mendes, Jose Ubiragi de Lima [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)], e-mails: lguilherme@dem.ufrn.br, diltonsodre@ifba.edu.br, ubiragi@ct.ufrn.br

    2010-07-01

    It is presented s solar collector to be used in a heating water for bath system, whose main characteristics are low cost and easy fabrication and assembly processes. The collector absorber surface consists of a polycarbonate plate with an area of 1.5 m{sup 2}. The water inlet and outlet are made of PVC 50mm, and were coupled to a 6mm thick polycarbonate plate using fiberglass resin. A 200 liters thermal reservoir will be used. This reservoir is also alternative. The absorber heating system works under thermo-siphon regimen. Thermal parameters will be evaluated to prove the feasibility of the studied solar heating system to obtain bath water for a four people family. (author)

  8. Influence of reflectance from flat aluminum concentrators on energy efficiency of PV/Thermal collector

    International Nuclear Information System (INIS)

    Kostic, Ljiljana T.; Pavlovic, Tomislav M.; Pavlovic, Zoran T.

    2010-01-01

    In this paper the results of the influence of reflectance from flat plate solar radiation concentrators made of Al sheet and Al foil on energy efficiency of PV/Thermal collector are presented. The total reflectance from concentrators made of Al sheet and Al foil is almost the same, but specular reflectance which is bigger in concentrators made of Al foil results in increase of solar radiation intensity concentration factor. With the increase of solar radiation intensity concentration factor, total daily thermal and electrical energy generated by PV/Thermal collector with concentrators increase. In this work also optimal position of solar radiation concentrators made of Al sheet and Al foil and appropriate thermal and electrical efficiency of PV/Thermal collector have been determined. Total energy generated by PV/Thermal collector with concentrators made of Al foil in optimal position is higher than total energy generated by PV/Thermal collector with concentrators made of Al sheet.

  9. Solar powered adsorption refrigerator with CPC collection system: Collector design and experimental test

    International Nuclear Information System (INIS)

    Gonzalez, Manuel I.; Rodriguez, Luis R.

    2007-01-01

    Solar adsorption cooling systems are usually based on the flat plate collector, whereas little attention has been paid to concentrating collectors. Compound parabolic concentrators (CPC) are a versatile class of solar collectors that can be adapted to a large variety of applications and geometries. This work presents a CPC collector whose tubular receiver contains the sorption bed and where only a portion of the receiver is exposed to sunlight. Geometric characteristics of the proposed CPC, such as the profile, the length and the height of the reflective sheet are given. A prototype of a solar adsorption chiller using this type of collector and the activated carbon-methanol working pair is described, and typical experimental results are reported. In particular, the measured solar COP ranges from 0.078 to 0.096

  10. Design package for concentrating solar collector panels

    Energy Technology Data Exchange (ETDEWEB)

    1978-08-01

    Information used to evaluate the design of the Northrup concentrating collector is presented. Included are the system performance specifications, the applications manual, and the detailed design drawings of the collector. The Northrup concentrating solar collector is a water/glycol/working fluid type, dipped galvanized steel housing, transparent acrylic Fresnel lens cover, copper absorber tube, fiber glass insulation and weighs 98 pounds. The gross collector area is about 29.4/sup 2/ per collector. A collector assembly includes four collector units within a tracking mount array.

  11. Experimental Investigation of a Direct Methanol Fuel Cell with Hilbert Fractal Current Collectors

    Directory of Open Access Journals (Sweden)

    Jing-Yi Chang

    2014-01-01

    Full Text Available The Hilbert curve is a continuous type of fractal space-filling curve. This fractal curve visits every point in a square grid with a size of 2×2, 4×4, or any other power of two. This paper presents Hilbert fractal curve application to direct methanol fuel cell (DMFC current collectors. The current collectors are carved following first, second, and third order Hilbert fractal curves. These curves give the current collectors different free open ratios and opening perimeters. We conducted an experimental investigation into DMFC performance as a function of the free open ratio and opening perimeter on the bipolar plates. Nyquist plots of the bipolar plates are made and compared using electrochemical impedance spectroscopy (EIS experiments to understand the phenomena in depth. The results obtained in this paper could be a good reference for future current collector design.

  12. Solar radiation on a catenary collector

    Science.gov (United States)

    Crutchik, M.; Appelbaum, J.

    1992-01-01

    A tent-shaped structure with a flexible photovoltaic blanket acting as a catenary collector is presented. The shadow cast by one side of the collector produces a shadow on the other side of the collector. This self-shading effect is analyzed. The direct beam, the diffuse, and the albedo radiation on the collector are determined. An example is given for the insolation on the collector operating on Viking Lander 1 (VL1).

  13. Design package for concentrating solar collector panels

    Science.gov (United States)

    1978-01-01

    Information used to evaluate the design of the Northrup concentrating collector is presented. Included are the system performance specifications, the applications manual, and the detailed design drawings of the collector. The collector is a water/glycol/working fluid type, with a dipped galvanized steel housing, transparent acrylic Fresnel lens cover, copper absorber tube, and fiber glass insulation. It weights 98 pounds. A collector assembly includes four collector units within a tracking mount array.

  14. A distributed garbage collector for active objects

    OpenAIRE

    Puaut , Isabelle

    1993-01-01

    This paper introduces an algorithm that performs garbage collection in distributed systems of active objects (i.e., objects having their own threads of control). The proposed garbage collector is made of a set of local garbage collectors, one per node, loosely coupled to a global garbage collector. The novelties of the proposed garbage collector come from the fact that local garbage collectors need not be synchronized with each other for detecting garbage objects and that faulty communication...

  15. Study of Cylindrical Honeycomb Solar Collector

    Directory of Open Access Journals (Sweden)

    Atish Mozumder

    2014-01-01

    Full Text Available We present the results of our investigation on cylindrical honeycomb solar collector. The honeycomb has been fabricated with transparent cellulose triacetate polymer sheets. Insulation characteristics of the honeycomb were studied by varying the separation between the honeycomb and the absorber plate. The optimal value of the separation was found to be 3.3 mm for which the heat transfer coefficient is 3.06 W m−2 K−1. This supports result of previous similar experiments. Further we test the honeycomb through a field experiment conducted in Delhi (28.6°N, 77°E and found that when the incident angle of the solar radiation is within 20° then the performance of the system with the honeycomb is better than the one without the honeycomb.

  16. Electrochemical Properties of Current Collector in the All-vanadium Redox Flow Battery

    International Nuclear Information System (INIS)

    Hwang, Gan-Jin; Oh, Yong-Hwan; Ryu, Cheol-Hwi; Choi, Ho-Sang

    2014-01-01

    Two commercial carbon plates were evaluated as a current collector (bipolar plate) in the all vanadium redox-flow battery (V-RFB). The performance properties of V-RFB were test in the current density of 60 mA/cm 2 . The electromotive forces (OCV at SOC 100%) of V-RFB using A and B current collector were 1.47 V and 1.54 V. The cell resistance of V-RFB using A current collector was 4.44-5.00 Ω·cm 2 and 3.28-3.75 Ω·cm 2 for charge and discharge, respectively. The cell resistance of V-RFB using B current collector was 4.19-4.42Ω·cm 2 and 4.71-5.49Ω·cm 2 for charge and discharge, respectively. The performance of V-RFB using each current collector was evaluated. The performance of V-RFB using A current collector was 93.1%, 76.8% and 71.4% for average current efficiency, average voltage efficiency and average energy efficiency, respectively. The performance of V-RFB using B current collector was 96.4%, 73.6% and 71.0% for average current efficiency, average voltage efficiency and average energy efficiency, respectively

  17. Sila kojom vazduh pritiska pokretnu ploču/Force of the air pressure on a moving plate

    Directory of Open Access Journals (Sweden)

    Leonid Ivanovich Gretchihin

    2014-10-01

    Full Text Available U radu je razrađena matematički model gasodinamičkog opstrujavanja ravne ploče pri njenom kretanju sa pozitivnim i negativnim napadnim uglom. Pokazano je da pri malim brzinama kretanja, silu uzgona i čeoni otpor određuje gasodinamički tok vazduha u izlaznoj oblasti opstrujavanja, a pri brzinama kretanja koje su bliske brzini zvuka odlučujuću ulogu vrši uzajamno udarno dejstvo ploče sa molekulima okružujuće sredine u ulaznoj oblasti opstrujavanja. Otcepljena struja iza ploče se ne pojavljuje pri malim brzinama kretanja. Određeni su uslovi kada čeoni otpor i sila uzgona ploče menjaju znak. / (ruski Razrabotana matematičeskaja model' gazodinamičeskogo obtekanija ploskoj plastiny pri ee dviženii s položitel'nym i otricatel'nym uglom ataki. Pokazano, čto pri malyh skorostjah dviženija plastiny pod''emnaja sila i lobovoe soprotivlenie opredeljajutsja gazodinamikoj tečenija vozduha v tyl'noj oblasti, a pri skorostjah dviženija blizkih k skorosti zvuka rešajuščuju rol' vypolnjaet udarnoe vzaimodejstvie plastiny s molekulami okružajuščej sredy v perednej oblasti. Sryvnoe tečenie za plastinoj pri malyh skorostjah dviženija ne voznikaet. Opredeleny uslovija, kogda lobovoe soprotivlenie i pod''emnaja sila plastiny izmenjaet znak. / This paper developed a mathematical model of gas dynamic fluid flow for a flat plate during its movement with positive and negative angles of attack. It is shown that at low velocities, the lifting force and the frontal resistance are determined by gasdynamic air flow in the fluid flow exit areawhile at velocities close to the speed of sound the decisive role is played by a mutualeffect of the pplate coliding with molecules of the surrounding environment in the fluid flow incidence field. The airflow behind the plate does not appear at low velocities. The conditions when the frontal resistance and the lifting force change the sign are determined.

  18. Method of forming oxide coatings. [for solar collector heating panels

    Science.gov (United States)

    Mcdonald, G. E. (Inventor)

    1983-01-01

    This invention is concerned with an improved plating process for covering a substrate with a black metal oxide film. The invention is particularly directed to making a heating panel for a solar collector. A compound is electrodeposited from an aqueous solution containing cobalt metal salts onto a metal substrate. This compound is converted during plating into a black, highly absorbing oxide coating which contains hydrated oxides. This is achieved by the inclusion of an oxidizing agent in the plating bath. The inclusion of an oxidizing agent in the plating bath is contrary to standard electroplating practice. The hydrated oxides are converted to oxides by treatment in a hot bath, such as boiling water. An oxidizing agent may be added to the hot liquid treating bath.

  19. Comparative study of solar cooling systems with building-integrated solar collectors for use in sub-tropical regions like Hong Kong

    International Nuclear Information System (INIS)

    Fong, K.F.; Lee, C.K.; Chow, T.T.

    2012-01-01

    Highlights: ► Performance of building-integrated solar collectors analyzed. ► Comparisons made with solar collectors installed on roof. ► Use of building-integrated solar collectors increased the total primary consumption. ► Reduction in the building load could not compensate drop in solar collector output. ► Building-integrated solar collectors only used when roof space insufficient. -- Abstract: The performance of solar cooling systems with building-integrated (BI) solar collectors was simulated and the results compared with those having the solar collectors installed conventionally on the roof based on the weather data in Hong Kong. Two types of solar collectors and the corresponding cooling systems, namely the flat-plate collectors for absorption refrigeration and the PV panels for DC-driven vapour compression refrigeration, were used in the analysis. It was found that in both cases, the adoption of BI solar collectors resulted in a lower solar fraction (SF) and consequently a higher primary energy consumption even though the zone loads were reduced. The reduction in SF was more pronounced in the peak load season when the solar radiation was nearly parallel to the solar collector surfaces during the daytimes, especially for those facing the south direction. Indeed, there were no outputs from the BI flat-plate collectors facing the south direction between May and July. The more severe deterioration in the system performance with the BI flat-plate type collectors made them technically infeasible in terms of the energy-saving potential. It was concluded that the use of BI solar collectors in solar cooling systems should be restricted only to situations where the availability of the roof was limited or insufficient when applied in sub-tropical regions like Hong Kong.

  20. Experimental Study On Efficiency Of Solar Collector At Nagpur India During Winter

    Directory of Open Access Journals (Sweden)

    Jayant. V. Madan

    2015-08-01

    Full Text Available Abstract In this experimental study the active solar water heating direct circulation systems the thermo siphon solar flat plate collector has been tested at Government medical college 21.15N 79.09E Nagpur Maharashtra India. The various data needed are collected from Indian metrological department and during months from November to January i.e. during the winter season the responses from the system has been studied and analyzed. The maximum temperature was obtained was around 70c and the minimum ambient temperature was 18c. The objective of the present work is to evaluate efficiency of flat plate collector in Nagpur region considering these aspects of the flat plate collector both theoretically and experimentally. A test setup is fabricated and experiments conducted to study these aspects.

  1. Numerical analysis of the influence of spherical turbulence generators on heat transfer enhancement of flat plate solar air heater

    International Nuclear Information System (INIS)

    Manjunath, M.S.; Karanth, K.Vasudeva; Sharma, N.Yagnesh

    2017-01-01

    This paper presents the influence of spherical turbulence generators on thermal efficiency and thermohydraulic performance of flat plate solar air heater. The analysis is carried out for the Reynolds number range of 4000–25000. The thermal performance is investigated for various diameter (D) of sphere consisting of 5,10,15,20 and 25 mm and relative roughness pitch (P/D) of 3, 6 and 12. The simulation is carried out using solar insolation as heat input at 12 noon conditions for the global position of Manipal (74.786°E, 13.343°N) obtained through the solar load model, a feature available in the software tool used for the analysis and Discrete Ordinates radiation model is used to compute the radiation heat interactions within the computational domain. The CFD results for the base model are validated against experimental results and are found to have good agreement. The thermal efficiency is found to increase with increasing sphere diameter and reducing relative roughness pitch. The maximum average percentage increase in thermal efficiency is found to be about 23.4% as compared to the base model for D = 25 mm and P/D = 3. The highest increase in the Nusselt number is found to be 2.5 times higher as compared to the base model for D = 25 mm and P/D = 3 at Re = 23560. The analysis shows that the relative roughness pitch and size of the spherical turbulator have significant influence on the thermohydraulic performance of solar air heater. - Highlights: • Spherical turbulators used create intense turbulent mixing in the vicinity of absorber. • Nusselt number peaks on the upstream surface of spherical turbulators. • Peak thermal efficiency occurs at lower pitch and higher diameter conditions. • Higher diameter and lower pitch values also impose greater pumping power penalty. • Diameter and pitch of spherical turbulator strongly influence the effective efficiency.

  2. Investigation of heat transfer and fluid flow in transitional regime inside a channel with staggered plates heated by radiation for PV/T system

    International Nuclear Information System (INIS)

    Ali, Ahmed Hamza H.; Ahmed, Mahmoud; Abdel-Gaied, S.M.

    2013-01-01

    This study investigates experimentally and theoretically the effects of operating and configuration parameters on convection heat transfer process and fluid flow characteristics for air flowing in transitional regimes through parallel plate channels with staggered plates segments heated by radiant heat flux. This configuration is to be utilized in air heater solar collectors and/or in a combined photovoltaic and air heater solar collector systems (PV/T). The operating parameters tested were Reynolds number (Re) values ranging from 2580 to 4650 with a combination of incident radiation heat flux (q inc ) values of 400, 700, and 1000 W/m 2 , respectively. The experimental results show that the local Nusselt number (Nu x ) is not unique function of the axial distance, in addition, a linear relationship between Re and apparent friction factor (f) was observed. Moreover, the model results show that combination of Re values in the laminar flow regime with proper selection of both plate's length and thickness can lead to enhancement in the heat transfer from the plate segments to the air stream. This is due to self-oscillatory flow mixer in wake zone behind each plate segment. Consequently, this will lead to avoid the need of more pumping power for the case of the flow falling within the transitional regime in the channel. - Highlights: • The local heat transfer coefficient is not unique function in the axial distance. • A linear relationship between Reynolds number and apparent friction factor is observed for Re > 3500. • The plate thickness is the dominant parameter affects both values of the heat transfer and friction factor. • Shorter plates' length, at any plate thickness, leads to periodic boundary layers interruption mechanisms

  3. Development of a selective surface vacuum collector. Final report

    Energy Technology Data Exchange (ETDEWEB)

    de Waal, H.; Simonis, F.

    1980-01-01

    To make solar energy useful for cooling applications a flat plate high performance collector, which can supply solar energy at 100 to 150/sup 0/C, has been developed. To achieve a reasonable efficiency at these temperatures the thermal heat loss must be very small. This has been obtained by (1) concentration of sunlight (c = 1.6); (2) evacuation of the collector housing to eliminate convection currents (pressure less than or equal to 4kPa); (3) spectral selective coating on the absorber; and (4) a low conductive gas in the collector housing (pressure approx. = 2kPa). The collector consists of a metal box with a glass cover hermetically sealed to it in the way double glazing units are manufactured. The sides of the V-trough concentrators support the glass cover. Measurements have been performed concerning heat loss factor and durability of the vacuum. The first prototype, fitted with a spectral selective coating of tin-oxide on enameled steel (epsilon = 0.25) showed a heat-loss of 2.0 W/m/sup 2/ /sup 0/C at 90/sup 0/C, being in reasonable agreement with calculations. Improvements with respect to the spectral selective coating and the use of a low conductive gas are necessary and will lead to a heat loss factor of about 1 W/m/sup 2/ /sup 0/C. Measurements have shown that in the chosen system the desired vacuum level can be maintained for at least 10 to 15 years.

  4. Installation package for concentrating solar collector panels

    Science.gov (United States)

    1978-01-01

    The concentrating solar collector panels comprise a complete package array consisting of collector panels using modified Fresnel prismatic lenses for a 10 to 1 concentrating ratio, supporting framework, fluid manifolding and tracking drive system, and unassembled components for field erection.

  5. Optimized concentrating/passive tracking solar collector. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Sterne, K E; Johnson, A L; Grotheer, R H

    1979-01-01

    A concentrating solar collector having about half the material cost of other collectors with similar performance is described. The selected design is a Compound Parabolic Concentrator (CPC) which concentrates solar energy throughout the year without requiring realignment. Output is a fluid heated to 100/sup 0/C with good efficiency. The optical design of the reflector surface was optimized, yielding a 2.0:1 concentration ratio with a 60/sup 0/C acceptance angle and a low profile. Double glazing was chosen consisting of a polyester film outer glazing and an inner glazing of glass tubes around the absorbers. The selectively coated steel absorber tubes are connected in series with flexible plastic tubing. Much development effort went into the materials for the reflector subassembly. A laminate of metalized plastic film over plaster was chosen for the reflective surface. The reflector is rigidized by attaching filled epoxy header plates at each end. Aluminum side rails and an insulating back complete the structure. The finished design resulted in a material cost of $21.40 per square meter in production quantities. Performance testing of a prototype produced a 50% initial efficiency rating. This is somewhat lower than expected, and is due to materials and processes used in the prototype for the outer glazing, reflective surface and absorber coating. However, the efficiency curve drops only slightly with increasing temperature differential, showing the inherent advantage of the concentrator over flat plate collectors.

  6. Heat transfer characteristics in the channel of a finned absorber solar collector; Caracteristicas da transferencia de calor no canal de um coletor solar de absorvedor aletado

    Energy Technology Data Exchange (ETDEWEB)

    Saboya, Sergio Mourao [Centro Tecnico Aeroespacial, Sao Jose dos Campos, SP (Brazil). Inst. Tecnologico de Aeronautica; Saboya, Francisco Eduardo Mourao [Universidade Federal Fluminense, Niteroi, RJ (Brazil)]. E-mails: saboya@mec.ita.cta.br; fsaboya@mec.uff.br

    2000-07-01

    Finned absorber solar collectors are devices in which plates (fins) are fixed perpendicularly to the absorber plate. The purpose of these fins is to cause the so called 'cavity effect', lowering the collector losses. This paper studies the heat transfer that occurs in the collector channel. This analysis is done using the efficiency of the collector, which is calculated solving the system of equations that govern the collector thermal behavior, and the computation of the convection heat transfer between the fluid flowing in the channel and the absorber plate. This analysis allows the calculation of design parameters such as mass flow rate and exit bulk temperature of the fluid. (author)

  7. Investigations on efficiencies of HT solar collectors for different flow rates and collector tilts

    DEFF Research Database (Denmark)

    Chen, Ziqian; Perers, Bengt; Furbo, Simon

    2013-01-01

    Two HT solar collectors for solar heating plants from Arcon Solvarme A/S are tested in a laboratory test facility for solar collectors at Technical University of Denmark (DTU). The collectors are designed in the same way. However, one solar collector is equipped with an ETFE foil between the abso......Two HT solar collectors for solar heating plants from Arcon Solvarme A/S are tested in a laboratory test facility for solar collectors at Technical University of Denmark (DTU). The collectors are designed in the same way. However, one solar collector is equipped with an ETFE foil between...... the absorber and the cover glass and the other is without ETFE foil. The efficiencies for the collectors are tested at different flow rates and tilt. On the basis of the measured efficiencies, the efficiencies for the collectors as functions of flow rates are obtained. The calculated efficiencies are in good...

  8. Assessment of long-term and large-scale even-odd license plate controlled plan effects on urban air quality and its implication

    Science.gov (United States)

    Zhao, Suping; Yu, Ye; Qin, Dahe; Yin, Daiying; He, Jianjun

    2017-12-01

    To solve traffic congestion and to improve urban air quality, long-lasting and large-scale even-odd license plate controlled plan was implemented by local government during 20 November to 26 December 2016 in urban Lanzhou, a semi-arid valley city of northwest China. The traffic control measures provided an invaluable opportunity to evaluate its effects on urban air quality in less developed cities of northwest China. Based on measured simultaneously air pollutants and meteorological parameters, the abatement of traffic-related pollutants induced by the implemented control measures such as CO, PM2.5 and PM10 (the particulate matter with diameter less than 2.5 μm and 10 μm) concentrations were firstly quantified by comparing the air quality data in urban areas with those in rural areas (uncontrolled zones). The concentrations of CO, NO2 from motor vehicles and fine particulate matter (PM2.5) were shown to have significant decreases of 15%-23% during traffic control period from those measured before control period with hourly maximum CO, PM2.5, and NO2/SO2 reduction of 43%, 35% and 141.4%, respectively. The influence of the control measures on AQI (air quality index) and ozone was less as compared to its effect on other air pollutants. Therefore, to alleviate serious winter haze pollution in China and to protect human health, the stringent long-term and large-scale even-odd license plate controlled plan should be implemented aperiodically in urban areas, especially for the periods with poor diffusion conditions.

  9. Thermal advantage of tracking solar collectors under Danish weather conditions

    DEFF Research Database (Denmark)

    Andersen, Elsa; Dragsted, Janne; Furbo, Simon

    2010-01-01

    Theoretical investigations have been carried out with the aim to elucidate the thermal advantage of tracking solar collectors for different weather conditions in Kgs. Lyngby, Denmark (55.8°N), and for the weather conditions in Sisimiut, Greenland (66.9°N), just north of the arctic circle....... The investigations are based on calculations with a newly developed program. Measured weather data from a solar radiation measurement station at Technical University of Denmark in Kgs. Lyngby Denmark in the period 1990 to 2002 and the Danish Design Reference Year, DRY data file are used in the investigations....... The weather data used for Sisimiut are based on a Test Reference Year, TRY weather data file. The thermal advantages of different tracking strategies is investigated for two flat plate solar collectors with different efficiencies, operated at different temperature levels. The investigations show...

  10. The thermal performance of the two-pass, two-glass-cover solar air heater

    Energy Technology Data Exchange (ETDEWEB)

    Persad, P.; Sateunanathan, S.

    1983-08-01

    Analytic models are developed for the performance prediction of a two-glass-cover solar air heater operated in both the single-pass and two-pass modes. It is shown that the two-pass mode of operation is superior to the single-pass mode of operation over the range of collector inlet temperatures considered. This is seen to be mainly due to the fact that, in the two-pass mode of operation, the outer glass cover is cooled by the working fluid, thereby reducing the top losses. It is also shown that the performance in the two-pass mode of operation is independent of length, over the range of collector lengths considered, and that a critical plate spacing, dependent on the temperature level of operation of the collector, is indicated. Predicted values of performance are in good agreement with experimental results.

  11. Design and beam transport simulations of a multistage collector for the Israeli EA-FEM

    Science.gov (United States)

    Tecimer, M.; Canter, M.; Efimov, S.; Gover, A.; Sokolowski, J.

    2001-12-01

    A four stage asymmetric type depressed collector has been designed for the Israeli mm-wave FEM that is driven by a 1.4 MeV, 1.5 A electron beam. After leaving the interaction section the spent beam has an energy spread of 120 keV and 75 π mm mrad normalized beam emittance. Simulations of the beam transport system from the undulator exit through the decelerator tube into the collector have been carried out using EGUN and GPT codes. The latter has also been employed to study trajectories of the primary and scattered particles within the collector, optimizing the asymmetrical collector geometry and the electrode potentials at the presence of a deflecting magnetic field. The estimated overall system and collector efficiencies reach 50% and 70%, respectively, with a beam recovery of 99.6%. The design is aimed to attain millisecond long pulse operation and subsequently 1 kW average power. Simulation results are implemented in a mechanical design that leads to a simple, cost efficient assembly eliminating ceramic insulator rings between collector stages and the associated brazing in the manufacturing process. Instead, each copper plate is supported by insulating posts and freely displaceable within the vacuum chamber. We report on the simulation results of the beam transport and recovery systems and on the mechanical aspects of the multistage collector design.

  12. Design and beam transport simulations of a multistage collector for the Israeli EA-FEM

    Energy Technology Data Exchange (ETDEWEB)

    Tecimer, M. E-mail: tecimer@post.tau.ac.il; Canter, M.; Efimov, S.; Gover, A.; Sokolowski, J

    2001-12-21

    A four stage asymmetric type depressed collector has been designed for the Israeli mm-wave FEM that is driven by a 1.4 MeV, 1.5 A electron beam. After leaving the interaction section the spent beam has an energy spread of 120 keV and 75 {pi} mm mrad normalized beam emittance. Simulations of the beam transport system from the undulator exit through the decelerator tube into the collector have been carried out using EGUN and GPT codes. The latter has also been employed to study trajectories of the primary and scattered particles within the collector, optimizing the asymmetrical collector geometry and the electrode potentials at the presence of a deflecting magnetic field. The estimated overall system and collector efficiencies reach 50% and 70%, respectively, with a beam recovery of 99.6%. The design is aimed to attain millisecond long pulse operation and subsequently 1 kW average power. Simulation results are implemented in a mechanical design that leads to a simple, cost efficient assembly eliminating ceramic insulator rings between collector stages and the associated brazing in the manufacturing process. Instead, each copper plate is supported by insulating posts and freely displaceable within the vacuum chamber. We report on the simulation results of the beam transport and recovery systems and on the mechanical aspects of the multistage collector design.

  13. Design and beam transport simulations of a multistage collector for the Israeli EA-FEM

    International Nuclear Information System (INIS)

    Tecimer, M.; Canter, M.; Efimov, S.; Gover, A.; Sokolowski, J.

    2001-01-01

    A four stage asymmetric type depressed collector has been designed for the Israeli mm-wave FEM that is driven by a 1.4 MeV, 1.5 A electron beam. After leaving the interaction section the spent beam has an energy spread of 120 keV and 75 π mm mrad normalized beam emittance. Simulations of the beam transport system from the undulator exit through the decelerator tube into the collector have been carried out using EGUN and GPT codes. The latter has also been employed to study trajectories of the primary and scattered particles within the collector, optimizing the asymmetrical collector geometry and the electrode potentials at the presence of a deflecting magnetic field. The estimated overall system and collector efficiencies reach 50% and 70%, respectively, with a beam recovery of 99.6%. The design is aimed to attain millisecond long pulse operation and subsequently 1 kW average power. Simulation results are implemented in a mechanical design that leads to a simple, cost efficient assembly eliminating ceramic insulator rings between collector stages and the associated brazing in the manufacturing process. Instead, each copper plate is supported by insulating posts and freely displaceable within the vacuum chamber. We report on the simulation results of the beam transport and recovery systems and on the mechanical aspects of the multistage collector design

  14. Modification of the Hottel-Whillier-Bliss equation for cover absorption effects in solar collectors

    Energy Technology Data Exchange (ETDEWEB)

    Wijeysundera, N E

    1981-01-01

    The effects of solar radiation absorption and the thermal resistance of a solar collector cover system on the various factors which occur in the Hottel-Whillier-Bliss (HWB) equation are considered. It is shown that by extending the thermal network analogy to systems with distributed heat sources, the heat transfer analysis of the collector can be done with little computational effort. The analysis also leads to a simple form of the HWB equation, with additional factors to account for the source distribution and the thermal resistance of the cover system, and it is applicable to conventional flat plate collectors and to other thermal trap collectors. A series of calculations for multilayer systems is presented to show the relative importance of the various factors in the modified HWB equation for different cover configurations.

  15. Economic analysis of flat plate collectors of solar energy

    International Nuclear Information System (INIS)

    Ozsabuncuoglu, I.H.

    1995-01-01

    Although solar energy potential in Turkey is far more than its total annual energy consumption, because of technical, economic and efficiency problems it cannot be harnessed to its fullest extent. Solar energy collecting systems have an initial cost two to five times higher than alternatives using electricity, LPG, fuel or other solid energy sources. However, their annual repair and maintenance costs are much lower than alternatives due to high energy prices. Solar systems with inflated annual costs have a minimum present value of US$867.19. Solar energy systems can be recommended for the countries that want a dependable and environmentally sound energy source. However, investment in R and D activities is necessary to reduce total cost of the system through improved efficiency and better production technology. (author)

  16. Production of atmospheric pressure diffuse nanosecond pulsed dielectric barrier discharge using the array needles-plate electrode in air

    International Nuclear Information System (INIS)

    Yang Dezheng; Wang Wenchun; Jia Li; Nie Dongxia; Shi Hengchao

    2011-01-01

    In this paper, a bidirectional high pulse voltage with 20 ns rising time is employed to generate an atmospheric pressure diffuse dielectric barrier discharge using the array needles-plate electrode configuration. Both double needle and multiple needle electrode configurations nanosecond pulsed dielectric barrier discharges are investigated. It is found that a diffuse discharge plasma with low gas temperature can be obtained, and the plasma volume increases with the increase of the pulse peak voltage, but remains almost constant with the increase of the pulse repetition rate. In addition to showing the potential application on a topographically nonuniform surface treatment of the discharge, the multiple needle-plate electrode configuration with different needle-plate electrode gaps are also employed to generate diffuse discharge plasma.

  17. Thermal performance of a double-pass solar collector with porous media

    International Nuclear Information System (INIS)

    Elradi A Musa; Kamaruzzaman Sopian; Shahrir Abdullah

    2006-01-01

    Thermal performance of a double-pass solar collector has been developed for air following through the porous media. The porous media are arranged in different porosities to increase heat transfer, area density and the total heat transfer rate. A test collector was developed and tested indoors by varying the design features and operating conditions using a halogen-lamp simulator as a radiation source. An experimental setup as been designed and constructed. Comparisons of the theoretical and the experimental result have been conducted. This type of collector can be used for drying and heat applications such as solar industrial processes, space and solar drying of agricultural products

  18. Collector ring project at FAIR

    International Nuclear Information System (INIS)

    Dolinskii, A; Blell, U; Dimopoulou, C; Gorda, O; Leibrock, H; Litvinov, S; Laier, U; Schurig, I; Weinrich, U; Berkaev, D; Koop, I; Starostenko, A; Shatunov, P

    2015-01-01

    The collector ring is a dedicated ring for fast cooling of ions coming from separators at the FAIR project. To accommodate optimal technical solutions, a structure of a magnet lattice was recently reviewed and modified. Consequently, more appropriate technical solutions for the main magnets could be adopted. A general layout and design of the present machine is shown. The demanding extraction schemes have been detailed and open design issues were completed. (paper)

  19. Experimental study of heat transfer and thermal performance with longitudinal fins of solar air heater

    Directory of Open Access Journals (Sweden)

    Foued Chabane

    2014-03-01

    Full Text Available The thermal performance of a single pass solar air heater with five fins attached was investigated experimentally. Longitudinal fins were used inferior the absorber plate to increase the heat exchange and render the flow fluid in the channel uniform. The effect of mass flow rate of air on the outlet temperature, the heat transfer in the thickness of the solar collector, and the thermal efficiency were studied. Experiments were performed for two air mass flow rates of 0.012 and 0.016 kg s−1. Moreover, the maximum efficiency values obtained for the 0.012 and 0.016 kg s−1 with and without fins were 40.02%, 51.50% and 34.92%, 43.94%, respectively. A comparison of the results of the mass flow rates by solar collector with and without fins shows a substantial enhancement in the thermal efficiency.

  20. Experimental study of heat transfer and thermal performance with longitudinal fins of solar air heater.

    Science.gov (United States)

    Chabane, Foued; Moummi, Noureddine; Benramache, Said

    2014-03-01

    The thermal performance of a single pass solar air heater with five fins attached was investigated experimentally. Longitudinal fins were used inferior the absorber plate to increase the heat exchange and render the flow fluid in the channel uniform. The effect of mass flow rate of air on the outlet temperature, the heat transfer in the thickness of the solar collector, and the thermal efficiency were studied. Experiments were performed for two air mass flow rates of 0.012 and 0.016 kg s(-1). Moreover, the maximum efficiency values obtained for the 0.012 and 0.016 kg s(-1) with and without fins were 40.02%, 51.50% and 34.92%, 43.94%, respectively. A comparison of the results of the mass flow rates by solar collector with and without fins shows a substantial enhancement in the thermal efficiency.

  1. Multiple-effect diffusion solar still coupled with a vacuum-tube collector and heat pipe

    KAUST Repository

    Chong, Tze-Ling; Huang, Bin-Juine; Wu, Po-Hsien; Kao, Yeong-Chuan

    2014-01-01

    The present study develops a multiple-effect diffusion solar still (MEDS) with a bended-plate design in multiple-effect diffusion unit (MDU) to solve the peel-off problem of wick material. The MDU is coupled with a vacuum-tube solar collector

  2. Standard Practice for Exposure of Solar Collector Cover Materials to Natural Weathering Under Conditions Simulating Stagnation Mode

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1992-01-01

    1.1 This practice covers a procedure for the exposure of solar collector cover materials to the natural weather environment at elevated temperatures that approximate stagnation conditions in solar collectors having a combined back and edge loss coefficient of less than 1.5 W/(m2 · °C). 1.2 This practice is suitable for exposure of both glass and plastic solar collector cover materials. Provisions are made for exposure of single and double cover assemblies to accommodate the need for exposure of both inner and outer solar collector cover materials. 1.3 This practice does not apply to cover materials for evacuated collectors, photovoltaic cells, flat-plate collectors having a combined back and edge loss coefficient greater than 1.5 W/(m2 ·° C), or flat-plate collectors whose design incorporates means for limiting temperatures during stagnation. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard t...

  3. Two non-tracking solar collectors: Design criteria and performance analysis

    International Nuclear Information System (INIS)

    Ratismith, Wattana; Inthongkhum, Anusorn; Briggs, John

    2014-01-01

    Highlights: • A collector module designed to capture solar radiation efficiently is proposed. • Two different compound parabolic trough designs are examined and tested. • A novel design with a flat base trough and vertical absorber operates efficiently in direct and diffuse sunlight. - Abstract: We propose fixed (non-tracking) configurations of solar light collector modules which are designed to operate efficiently throughout the day, i.e. for varying incident angles of direct sunlight, and in conditions of diffuse solar irradiation. We present two trough designs of compound parabolic collector (CPC) type. One, a more conventional double-parabolic trough, has the absorber plate perpendicular to the vertical axis of the trough cross-section. The other, of a new flat-base shape, has the absorber plate parallel. The collectors have two novel features appropriate to non-tracking. The first is a smoothing of the power output over the day by the simple expedient of arranging three troughs tilted at different angles. The second is the original design of the flat-base trough allowing optimal interception of the caustic surfaces of this non-focussing device. By ray-tracing analysis of the different trough shapes and absorber plate orientation, we emphasise the design criteria for achievement of a high intercept factor throughout the day without tracking and demonstrate the superiority of the flat-base collector over the double-parabolic design. In test experiments we show that the high temperatures (≈180 °C) necessary for some industrial process heat applications can be achieved. Also test results of the efficiency of the proposed systems are presented which indicate that the flat-base trough with vertical absorber plate is superior to the double-parabolic trough with horizontal absorber plate

  4. Modeling and Simulation of Turbulent Flows through a Solar Air Heater Having Square-Sectioned Transverse Rib Roughness on the Absorber Plate

    Directory of Open Access Journals (Sweden)

    Anil Singh Yadav

    2013-01-01

    Full Text Available Solar air heater is a type of heat exchanger which transforms solar radiation into heat energy. The thermal performance of conventional solar air heater has been found to be poor because of the low convective heat transfer coefficient from the absorber plate to the air. Use of artificial roughness on a surface is an effective technique to enhance the rate of heat transfer. A CFD-based investigation of turbulent flow through a solar air heater roughened with square-sectioned transverse rib roughness has been performed. Three different values of rib-pitch (P and rib-height (e have been taken such that the relative roughness pitch (P/e=14.29 remains constant. The relative roughness height, e/D, varies from 0.021 to 0.06, and the Reynolds number, Re, varies from 3800 to 18,000. The results predicted by CFD show that the average heat transfer, average flow friction, and thermohydraulic performance parameter are strongly dependent on the relative roughness height. A maximum value of thermohydraulic performance parameter has been found to be 1.8 for the range of parameters investigated. Comparisons with previously published work have been performed and found to be in excellent agreement.

  5. Modeling and simulation of turbulent flows through a solar air heater having square-sectioned transverse rib roughness on the absorber plate.

    Science.gov (United States)

    Yadav, Anil Singh; Bhagoria, J L

    2013-01-01

    Solar air heater is a type of heat exchanger which transforms solar radiation into heat energy. The thermal performance of conventional solar air heater has been found to be poor because of the low convective heat transfer coefficient from the absorber plate to the air. Use of artificial roughness on a surface is an effective technique to enhance the rate of heat transfer. A CFD-based investigation of turbulent flow through a solar air heater roughened with square-sectioned transverse rib roughness has been performed. Three different values of rib-pitch (P) and rib-height (e) have been taken such that the relative roughness pitch (P/e = 14.29) remains constant. The relative roughness height, e/D, varies from 0.021 to 0.06, and the Reynolds number, Re, varies from 3800 to 18,000. The results predicted by CFD show that the average heat transfer, average flow friction, and thermohydraulic performance parameter are strongly dependent on the relative roughness height. A maximum value of thermohydraulic performance parameter has been found to be 1.8 for the range of parameters investigated. Comparisons with previously published work have been performed and found to be in excellent agreement.

  6. A Systematic Study of Separators in Air-Breathing Flat-Plate Microbial Fuel Cells—Part 1: Structure, Properties, and Performance Correlations

    Directory of Open Access Journals (Sweden)

    Sona Kazemi

    2016-01-01

    Full Text Available Passive air-breathing microbial fuel cells (MFCs are a promising technology for energy recovery from wastewater and their performance is highly dependent on characteristics of the separator that isolates the anaerobic anode from the air-breathing cathode. The goal of the present work is to systematically study the separator characteristics and its effect on the performance of passive air-breathing flat-plate MFCs (FPMFCs. This was performed through characterization of structure, properties, and performance correlations of eight separators in Part 1 of this work. Eight commercial separators were characterized, in non-inoculated and inoculated setups, and were examined in passive air-breathing FPMFCs with different electrode spacing. The results showed a decrease in the peak power density as the oxygen and ethanol mass transfer coefficients in the separators increased, due to the increase of mixed potentials especially at smaller electrode spacing. Increasing the electrode spacing was therefore desirable for the application of diaphragms. The highest peak power density was measured using Nafion®117 with minimal electrode spacing, whereas using Nafion®117 or Celgard® with larger electrode spacing resulted in similar peak powers. Part 2 of this work focuses on numerical modelling of the FPMFCs based on mixed potential theory, implementing the experimental data from Part 1.

  7. Measurement of air kerma rates for 6- to 7-MeV high-energy gamma-ray field by ionisation chamber and build-up plate.

    Science.gov (United States)

    Kowatari, Munehiko; Tanimura, Yoshihiko; Tsutsumi, Masahiro

    2014-12-01

    The 6- to 7-MeV high-energy gamma-ray calibration field by the (19)F(p, αγ)(16)O reaction is to be served at the Japan Atomic Energy Agency. For the determination of air kerma rates using an ionisation chamber in the 6- to 7-MeV high-energy gamma-ray field, the establishment of the charged particle equilibrium must be achieved during measurement. In addition to measurement of air kerma rates by the ionisation chamber with a thick build-up cap, measurement using the ionisation chamber and a build-up plate (BUP) was attempted, in order to directly determine air kerma rates under the condition of regular calibration for ordinary survey meters and personal dosemeters. Before measurements, Monte Carlo calculations were made to find the optimum arrangement of BUP in front of the ionisation chamber so that the charged particle equilibrium could be well established. Measured results imply that air kerma rates for the 6- to 7-MeV high-energy gamma-ray field could be directly determined under the appropriate condition using an ionisation chamber coupled with build-up materials. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. Exergy analysis of photovoltaic solar collector

    International Nuclear Information System (INIS)

    Sopian, K.; Othman, M.Y.Hj.

    1998-01-01

    The exergy analysis (availability or second law analysis) is applied to the photovoltaic thermal solar collector. Photovoltaic thermal collector is a special type of solar collector where electricity and heat are produced simultaneously. The electricity produced from the photovoltaic thermal collector is all converted into useful work. The available quantity of the heat collected can readily be determined by taking into account both the quantity (heat quantity) and quality ( a function of temperature) of the thermal energy. Therefore, using the concept of exergy allows heat produced from the thermal collector and the electricity generated from the photovoltaic cells to be compared or to be evaluated on the basis of a common measure such as the effectiveness on solar energy collection or the total amount of available energy. In this paper, the effectiveness of solar energy collection is called combined photovoltaic thermal exergy efficiency. An experimental setup of a double pas photovoltaic thermal solar collector has been deigned, fabricated and tested. (author)

  9. PV-hybrid and thermoelectric collectors

    Energy Technology Data Exchange (ETDEWEB)

    Rockendorf, G.; Sillmann, R. [Institut fuer Solarenergieforschung GmbH, Emmerthal (Germany); Podlowski, L.; Litzenburger, B. [SolarWerk GmbH, Teltow (Germany)

    1999-07-01

    Two different principles of thermoelectric cogeneration solar collectors have been realized and investigated. Concerning the first principle, the thermoelectric collector (TEC) delivers electricity indirectly by first producing heat and subsequently generating electricity by means of a thermoelectric generator. Concerning the second principle, the photovoltaic-hybrid collector (PVHC) uses photovoltaic cells, which are cooled by a liquid heat-transfer medium. The characteristics of both collector types are described. Simulation modules have been developed and implemented in TRNSYS 14.1 (1994), in order to simulate their behaviour in typical domestic hot-water systems. The discussion of the results shows that the electric output of the PV-hybrid collector is significantly higher than that of the thermoelectric collector. (author)

  10. Dual curvature acoustically damped concentrating collector. Semiannual technical progress report, June 1-December 1, 1978

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-12-01

    The project's first objective is to establish, analytically, the cost and performance of design choices within the boundaries of the basic proposed concept. With these cost and performance measures as a guide, the second project objective is to design a cost-effective Dual Curvature collector module and collector field array. The third objective is to establish technical and economic concept feasibility through prototype fabrication and test. The final objective is to define the Dual Curvature collector commercialization requirements. The Dual Curvature collector uses a unique reflector module consisting of a reflective film that is tensioned on a reflector support frame. The tensioned membrane (film) surface approximates a hyperbolic paraboloid that is capable of linear focusing when the surface tracks the sun's apparent motion in one axis. The reflective film can be backed by polystyrene foam with an air space between the film and the foam surfaces. This provides damping of the reflector surface to minimize the effect of wind gusts and physical impacts. The baseline collector is intended to operate at a concentration of ten (10) or greater with a nominal absorber temperature of 150/sup 0/C (300/sup 0/F). The Component Research and Analysis tasks which lead to the selection of a baseline collector configuration are discussed. Also, some preliminary results of the Collector Module Design task are presented.

  11. Standardized performance tests of collectors of solar thermal energy: Prototype moderately concentrating grooved collectors

    Science.gov (United States)

    1976-01-01

    Prototypes of moderately concentrating grooved collectors were tested with a solar simulator for varying inlet temperature, flux level, and incident angle. Collector performance is correlated in terms of inlet temperature and flux level.

  12. Performance Evaluation of a Nanofluid-Based Direct Absorption Solar Collector with Parabolic Trough Concentrator

    Directory of Open Access Journals (Sweden)

    Guoying Xu

    2015-12-01

    Full Text Available Application of solar collectors for hot water supply, space heating, and cooling plays a significant role in reducing building energy consumption. For conventional solar collectors, solar radiation is absorbed by spectral selective coating on the collectors’ tube/plate wall. The poor durability of the coating can lead to an increased manufacturing cost and unreliability for a solar collector operated at a higher temperature. Therefore, a novel nanofluid-based direct absorption solar collector (NDASC employing uncoated collector tubes has been proposed, and its operating characteristics for medium-temperature solar collection were theoretically and experimentally studied in this paper. CuO/oil nanofluid was prepared and used as working fluid of the NDASC. The heat-transfer mechanism of the NDASC with parabolic trough concentrator was theoretically evaluated and compared with a conventional indirect absorption solar collector (IASC. The theoretical analysis results suggested that the fluid’s temperature distribution in the NDASC was much more uniform than that in the IASC, and an enhanced collection efficiency could be achieved for the NDASC operated within a preferred working temperature range. To demonstrate the feasibility of the proposed NDASC, experimental performances of an NDASC and an IASC with the same parabolic trough concentrator were furthermore evaluated and comparatively discussed.

  13. Performance Evaluation of a Nanofluid-Based Direct Absorption Solar Collector with Parabolic Trough Concentrator

    Science.gov (United States)

    Xu, Guoying; Chen, Wei; Deng, Shiming; Zhang, Xiaosong; Zhao, Sainan

    2015-01-01

    Application of solar collectors for hot water supply, space heating, and cooling plays a significant role in reducing building energy consumption. For conventional solar collectors, solar radiation is absorbed by spectral selective coating on the collectors’ tube/plate wall. The poor durability of the coating can lead to an increased manufacturing cost and unreliability for a solar collector operated at a higher temperature. Therefore, a novel nanofluid-based direct absorption solar collector (NDASC) employing uncoated collector tubes has been proposed, and its operating characteristics for medium-temperature solar collection were theoretically and experimentally studied in this paper. CuO/oil nanofluid was prepared and used as working fluid of the NDASC. The heat-transfer mechanism of the NDASC with parabolic trough concentrator was theoretically evaluated and compared with a conventional indirect absorption solar collector (IASC). The theoretical analysis results suggested that the fluid’s temperature distribution in the NDASC was much more uniform than that in the IASC, and an enhanced collection efficiency could be achieved for the NDASC operated within a preferred working temperature range. To demonstrate the feasibility of the proposed NDASC, experimental performances of an NDASC and an IASC with the same parabolic trough concentrator were furthermore evaluated and comparatively discussed. PMID:28347112

  14. Low temperature desalination using solar collectors augmented by thermal energy storage

    International Nuclear Information System (INIS)

    Gude, Veera Gnaneswar; Nirmalakhandan, Nagamany; Deng, Shuguang; Maganti, Anand

    2012-01-01

    Highlights: ► A new low temperature desalination process using solar collectors was investigated. ► A thermal energy storage tank (TES) was included for continuous process operation. ► Solar collector area and TES volumes were optimized by theoretical simulations. ► Economic analysis for the entire process was compared with and without TES tank. ► Energy and emission payback periods for the solar collector system were reported. -- Abstract: A low temperature desalination process capable of producing 100 L/d freshwater was designed to utilize solar energy harvested from flat plate solar collectors. Since solar insolation is intermittent, a thermal energy storage system was incorporated to run the desalination process round the clock. The requirements for solar collector area as well as thermal energy storage volume were estimated based on the variations in solar insolation. Results from this theoretical study confirm that thermal energy storage is a useful component of the system for conserving thermal energy to meet the energy demand when direct solar energy resource is not available. Thermodynamic advantages of the low temperature desalination using thermal energy storage, as well as energy and environmental emissions payback period of the system powered by flat plate solar collectors are presented. It has been determined that a solar collector area of 18 m 2 with a thermal energy storage volume of 3 m 3 is adequate to produce 100 L/d of freshwater round the clock considering fluctuations in the weather conditions. An economic analysis on the desalination system with thermal energy storage is also presented.

  15. Depressed collectors for millimeter wave gyrotrons

    International Nuclear Information System (INIS)

    Singh, A.; Granatstein, V.L.

    1992-01-01

    The main issues relating to design of depressed collectors for millimeter wave gyrotrons are discussed. A flow diagram is presented and the interlinking steps are outlined. Design studies are given for two kinds of gyrotrons on which severe constraints on the maximum radii of the collectors had been imposed; namely, for a cavity type and a quasi-optical gyrotron. A collector efficiency of the order of 70 percent is shown to be feasible for either case using careful tailoring of magnetic field profiles. A code has been developed to assist in doing this. A general approach toward initial placement of collectors has been indicated

  16. Performance and cost benefits analysis of double-pass solar collector with and without fins

    International Nuclear Information System (INIS)

    Fudholi, Ahmad; Sopian, Kamaruzzaman; Ruslan, Mohd Hafidz; Othman, Mohd Yusof

    2013-01-01

    Highlights: • The thermal performances and cost analysis of the double-pass solar collector with and without fins absorber were discussed. • The theoretical and experimental study on the double-pass solar air collector with and without fins absorber was conducted. • The ratio of AC/AEG or the cost benefit ratio was presented. • The double-pass solar collector with fins absorber is more cost-effective compared to without fins absorber. - Abstract: The performance and cost benefit analysis of double-pass solar collector with and without fins have been conducted. The theoretical model using steady state analysis has been developed and compared with the experimental results. The performance curves of the double-pass solar collector with and without fins, which included the effects of mass flow rate and solar intensity on the thermal efficiency of the solar collector, were obtained. Results indicated that the thermal efficiency is proportional to the solar intensity at a specific mass flow rate. The thermal efficiency increased by 9% at a solar intensity of 425–790 W/m 2 and mass flow rate of 0.09 kg/s. The theoretical and experimental analysis showed a similar trend as well as close agreement. Moreover, a cost-effectiveness model has been developed examine the cost benefit ratio of double-pass solar collector with and without fins. Evaluation of the annual cost (AC) and the annual energy gain (AEG) of the collector were also performed. The results show that the double-pass solar collector with fins is more cost-effective compared to the double-pass solar collector without fins for mass flow rate of 0.01–0.07 kg/s. Also, simulations were obtained for the double-pass solar collector with fins at Nusselt number of 5.42–36.21. The energy efficiency of collector increases with the increase of Nusselt number. The results show that by increasing the Nusselt number simultaneously would drop the outlet temperature at any solar intensity. Increase in Nusselt number

  17. IMPACT OF SOLAR RADIATION CHANGE ON THE COLLECTOR EFFICIENTLY

    Directory of Open Access Journals (Sweden)

    Danuta Proszak-Miąsik

    2017-01-01

    Full Text Available In October 2014 in a building of Rzeszow University of Technology, a series of measurements was taken to calculate the parameters of a solar system with a flat collector, as installed on the roof of the building. The following parameters were obtained: the value of solar radiation intensity, the temperature of external air, the temperature on the collector, the temperature of water in the tank and the temperature of glycol on the supply and return lines. On the basis of the data received, charts were made to visually present how changes of solar radiation intensity affected parameters of the system. The study was conducted in autumn when the intensity of solar radiation decreases, compared with summer months. The publication aims to show that the solar system brings energy gains in periods of transition, and the instantaneous intensity of solar radiation are comparable to those in the summer.

  18. Numerical modelling of the effect of dry air traces in a helium parallel plate dielectric barrier discharge

    Science.gov (United States)

    Lazarou, C.; Belmonte, T.; Chiper, A. S.; Georghiou, G. E.

    2016-10-01

    A validated numerical model developed for the study of helium barrier discharges in the presence of dry air impurities is presented in this paper. The model was used to numerically investigate the influence of air traces on the evolution of the helium dielectric barrier discharge (DBD). The level of dry air used as impurity was in the range from 0 to 1500 ppm, which corresponds to the most commonly encountered range in atmospheric pressure discharge experiments. The results presented in this study clearly show that the plasma chemistry and consequently the discharge evolution is highly affected by the concentration level of impurities in the mixture. In particular, it was observed that air traces assist the discharge ignition at low concentration levels (~55 ppm), while on the other hand, they increase the burning voltage at higher concentration levels (~1000 ppm). Furthermore, it was found that the discharge symmetry during the voltage cycle highly depends on the concentration of air. For the interpretation of the results, a detailed analysis of the processes that occur in the discharge gap is performed and the main reaction pathways of ion production are described. Thanks to this approach, useful insight into the physics behind the evolution of the discharge is obtained.

  19. Models of the heat dynamics of solar collectors for performance testing

    DEFF Research Database (Denmark)

    Bacher, Peder; Madsen, Henrik; Perers, Bengt

    2011-01-01

    accurate estimates of parameters in physical models. The applied method is described by Kristensen et al. (2004) and implemented in the software CTSM1. Examples of successful applications of the method includes modelling the of the heat dynamics of integrated photo-voltaic modules (Friling et al., 2009......) and modelling of the heat dynamics of buildings (Madsen and Holst, 1995). Measurements obtained at a test site in Denmark during the spring 2010 are used for the modelling. The tested collector is a single glazed large area flat plate collector with selective absorber and Teflon anti convection layer. The test...

  20. Advanced Hybrid Particulate Collector Project Management Plan

    Energy Technology Data Exchange (ETDEWEB)

    Miller, S.J.

    1995-11-01

    As the consumption of energy increases, its impact on ambient air quality has become a significant concern. Recent studies indicate that fine particles from coal combustion cause health problems as well as atmospheric visibility impairment. These problems are further compounded by the concentration of hazardous trace elements such as mercury, cadmium, selenium, and arsenic in fine particles. Therefore, a current need exists to develop superior, but economical, methods to control emissions of fine particles. Since most of the toxic metals present in coal will be in particulate form, a high level of fine- particle collection appears to be the best method of overall air toxics control. However, over 50% of mercury and a portion of selenium emissions are in vapor form and cannot be collected in particulate control devices. Therefore, this project will focus on developing technology not only to provide ultrahigh collection efficiency of particulate air toxic emissions, but also to capture vapor- phase trace metals such as mercury and selenium. Currently, the primary state-of-the-art technologies for particulate control are fabric filters (baghouses) and electrostatic precipitators (ESPs). However, they both have limitations that prevent them from achieving ultrahigh collection of fine particulate matter and vapor-phase trace metals. The objective of this project is to develop a highly reliable advanced hybrid particulate collector (AHPC) that can provide > 99.99 % particulate collection efficiency for all particle sizes between 0.01 and 50 14m, is applicable for use with all U.S. coals, and is cost-0443competitive with existing technologies. Phase I of the project is organized into three tasks: Task I - Project Management, Reporting, and Subcontract Consulting Task 2 - Modeling, Design, and Construction of 200-acfm AHPC Model Task 3 - Experimental Testing and Subcontract Consulting

  1. STUDY AND NUMERICAL SIMULATION OF SOLAR SYSTEM FOR AIR HEATING

    Directory of Open Access Journals (Sweden)

    M. Ghodbane

    2016-01-01

    Full Text Available The use of solar energy in sunny countries, is an effective outil for compensate the lack in the energy, their benefits are not related only to its economic benefits but especially for the environmental protection, so we must find solutions to the problems of pollution. This work is a theoretical study of a solar flat plate collector ; air is used as the heat transfer fluid. In this study, we established in first step the calculation of solar radiation in various sites in Algeria (Adrar, El Oued, Bechar, Biskra and Tamanrasset. The second step is the parameters influence study of the sites and climate on the performance of our collector. The results obtained are encouraging for the use of this type in the heating in the winter, also it can be used in different kinds of drying.

  2. Studi Performansi Alat Pemanas Air dengan Menggunakan Kolektor Surya Plat Datar

    Directory of Open Access Journals (Sweden)

    Darwin Darwin

    2013-10-01

    Full Text Available This study aims to analyze the performance of the water heater using solar collector flat plate type. Efficiency performance of solar collectors in the process of heating the water also becomes the main focus in this study. This study was conducted with two experiments consisting of a flat plate solar collector with horizontal and flat plate solar collector with tilt angle 22o. Experiments carried out with 8 hours of testing within 6 days. Water was circulated into the collector pipe using a pump capacity of 125 Watts. From the research it is known that the amount of electrical energy required by pump for 6 days with 8 -hour time trial experiment, was about 21.6 MJ. The rate of flow of the fluid in the collector pipe is 2x10 - 5 m3/s. The plate solar collector with a slope of 22o reached the highest average temperature in the third experiment, which was about 64.7 ° C; however, the lowest average temperature was found in the horizontal collector (0o at the third experiment, which was about 47.5 ° C. It was found that the highest efficiency obtained at the collector plate with 22o tilt angle was equal to 76 % while the lowest efficiency was obtained at a horizontal collector with an efficiency of 53.6 %.   Keywords: solar collectors, flat plate, water heater

  3. Foldable Frame Supporting Electromagnetic Radiation Collectors

    DEFF Research Database (Denmark)

    2011-01-01

    The present invention relates to flexible frames supporting electromagnetic radiation collectors, such as antennas, antenna reflectors, deflectors or solar collectors, for celestial or terrestrial applications, which can be folded to be stored and/or transported. The method for stowing deforms...

  4. EFFECT OF BLENDING VARIOUS COLLECTORS AT BULK ...

    African Journals Online (AJOL)

    Nkana Concentrator under the ownership of the then Zambia Consolidated Copper Mines Ltd (ZCCM) had been using Sodium Ethyl Xanthate (SEX) mainly as a collector, but with the coming of new Mopani Copper Mines Plc (M.C.M), it was felt that there was a need to test alternative collectors in an attempt to improve the ...

  5. Performance of an absorbing concentrating solar collectors

    International Nuclear Information System (INIS)

    Imadojemu, H.

    1990-01-01

    This paper reports on a comparison of the efficiency of an absorbing fluid parabolic trough concentrating solar collector and a traditional concentrating collector that was made. In the absorbing fluid collector, black liquid flows through a glass tube absorber while the same black liquid flows through a selective black coated copper tube absorber while the same black fluid flows through a selective black coated copper tube absorber in the traditional collector. After a careful study of the properties of available black liquids, a mixture of water and black ink was chosen as the black absorbing medium or transfer fluid. In the black liquid glass collector there is a slightly improved efficiency based on beam radiation as a result of the direct absorption process and an increase in the effective transmittance absorptance. At worst the efficiency of this collector equals that of the traditional concentrating collector when the efficiency is based on total radiation. The collector's reflecting surfaces were made of aluminum sheet, parabolic line focus and with cylindrical receivers. The ease of manufacture and reduced cost per unit energy collected, in addition to the clean and pollution free mode of energy conversion, makes it very attractive

  6. Combined solar collector and energy storage system

    Science.gov (United States)

    Jensen, R. N. (Inventor)

    1980-01-01

    A combined solar energy collector, fluid chiller and energy storage system is disclosed. A movable interior insulated panel in a storage tank is positionable flush against the storage tank wall to insulate the tank for energy storage. The movable interior insulated panel is alternately positionable to form a solar collector or fluid chiller through which the fluid flows by natural circulation.

  7. Imitation experiment for water-treatment by heat of solar collector and hot pump

    International Nuclear Information System (INIS)

    Liao Yuanzong; Liu Shuqing; Pang Heding; Zhao Zhongxin; Zhang Biguang; Wang Xiping; Huo Guangqing

    1997-01-01

    The author presents an imitation experiment in which solar collector and hot pump are jointed for supplying heat to evaporate cleaned water and diffuse it into air. The effects of the temperature and the quantity of supplying air, and circumstance conditions on evaporation quantity are studied. The ratio of evaporating quantity to consuming energy, the efficiency of evaporation, average efficiency of solar collector and supplying heat coefficient of heat pump are measured. The experiment shows that this supplying heat model is practicable, economic and efficient for treating cleaned water

  8. Temporal and spatial evolution of EHD particle flow onset in air in a needle-to-plate negative DC corona discharge

    International Nuclear Information System (INIS)

    Mizeraczyk, J; Berendt, A; Podlinski, J

    2016-01-01

    In this paper we present images showing the temporal and spatial evolution of the electrohydrodynamic (EHD) flow of dust particles (cigarette smoke) suspended in still air in a needle-to-plate negative DC corona discharge arrangement just after the corona onset, i.e. in the first stage of development of the EHD particle flow. The experimental apparatus for our study of the EHD flow onset consisted of a needle-to-plate electrode arrangement, high voltage power supply and time-resolved EHD imaging system based on 2D time-resolved particle image velocimetry equipment. The time-resolved flow images clearly show the formation of a ball-like flow structure at the needle tip just after the corona discharge onset, and its evolution into a mushroom-like object moving to the collecting electrode. After a certain time, when the mushroom-like object is still present in the interelectrode gap a second mushroom-like object forms near the needle electrode and starts to move towards the collecting electrode. Before the first mushroom-like object reaches the collecting electrode several similar mushroom-like objects can be formed and presented simultaneously in the interelectrode gap. They look like a series of mushroom-like minijets shot from the needle electrode vicinity towards the collecting electrode. The simultaneous presence of mushroom-like minijets in the interelectrode gap in the corona discharge in particle-seeded air resembles the negative-ion-charged ‘clouds’ (induced by the Trichel pulses) traversing simultaneously the interelectrode gap of the corona discharge in air, predicted a long time ago by Loeb, and Lama and Gallo and recently by Dordizadeh et al . Analysing the time behaviours of the mushroom-like minijets and current waveform in the corona discharge in particle-seeded air, we found that the Trichel pulse trains, formed just after the corona onset initiates the mushroom-like minijets. The first stage of development of the EHD particle flow, the area of

  9. Convective drying of chilies using a concentrating solar collector

    International Nuclear Information System (INIS)

    Hanif, M.; Khattak, M.K.; Aamir, M.

    2015-01-01

    A concentrating solar collector was developed for convective drying of green chilies by providing optimum drying environment. A temperature in the range of 45-65 degree C and relative humidity of less than 10% was observed during the drying period provided by the solar collector from 9.00 am to 5.00 pm. Different levels of drying temperature and air mass flow rates were tested to find their effect on drying time of the chilies. The experiment was laid out as a randomized complete block design with a factorial arrangement of the treatments consisting of 3 levels of temperature and 3 levels of air mass flow rate, replicated 3 times. Drying temperature and air mass flow rates effected the drying time significantly. The means comparison showed that minimum drying time of 17.96 h was recorded at high temperature of 65 degree C followed by a drying time of 20.27 and 21.43 h at temperatures of 55 and 45 degree C. The means of air mass flow rates showed that minimum drying time of 18.49 h was noted at high air mass flow rate of 3.50 kg min-1 followed by 20.32 and 20.86 h at air mass flow rates of 1.5 and 2.30 kg min-l. Chilies dried at temperature of 65 degree C and air mass flow rate of 3.5 kg min-1 showed an average drying rate of 0.02 g(H20)hrl cm-2as compared to the slow drying rates at 55 and 45 degree C. It was concluded that chilies must be dried at high temperature and high air mass flow rates to get on time quality dried chilies. (author)

  10. Design, construction and testing of a low-cost flat plate solar energy ...

    African Journals Online (AJOL)

    A low-cost flat plate solar energy collector has been designed and constructed with locally available materials such as mild steel and black paint of absorptance 0.94. On testing, an average daily efficiency of 55.6% was obtained. The methods are simple and illustrate the fact that construction of efficient collectors are ...

  11. Experimental Comparison of Two Configurations of Hybrid Photovoltaic Thermal Collectors

    International Nuclear Information System (INIS)

    Khaled Toufeka; Mourad Haddadib; Ali Mkc

    2011-01-01

    The combination of a thermal collector and a photovoltaic module in a single system allows for increased efficiency of the total conversion of solar energy. A synergistic effect can be obtained in a structure combining these two devices in a judicious manner to those of thermal and photovoltaic system installed separately. Production of total energy from hybrid collector depends on the input (that is to say, the. energy of solar radiation, air temperature and wind speed) and output which is the electric production and the temperature of the system. Thin production also depends on the mode of heal extraction. In this paper, an experimental Study of two configurations of hybrid collectors is described. The configuration that the absorber is made by galvanized steel and in the second, the absorber is a copper serpentine. The advantages of the first configuration are mainly due to low cost and simplicity but the second configuration has the advantage of promoting the heat transfer between cells and fluid. (authors)

  12. Performance characteristics of solar air heater with surface mounted obstacles

    International Nuclear Information System (INIS)

    Bekele, Adisu; Mishra, Manish; Dutta, Sushanta

    2014-01-01

    Highlights: • Solar air heater with delta shaped obstacles have been studied. • Obstacle angle of incidence strongly affects the thermo-hydraulic performance. • Thermal performance of obstacle mounted collectors is superior to smooth collectors. • Thermo-hydraulic performance of the present SAH is higher than those in previous studies. - Abstract: The performance of conventional solar air heaters (SAHs) can be improved by providing obstacles on the heated wall (i.e. on the absorber plate). Experiments have been performed to collect heat transfer and flow-friction data from an air heater duct with delta-shaped obstacles mounted on the absorber surface and having an aspect ratio 6:1 resembling the conditions close to the solar air heaters. This study encompassed for the range of Reynolds number (Re) from 2100 to 30,000, relative obstacle height (e/H) from 0.25 to 0.75, relative obstacle longitudinal pitch (P l /e) from 3/2 to 11/2, relative obstacle transverse pitch (P t /b) from 1 to 7/3 and the angle of incidence (α) varied from 30° to 90°. The thermo-hydraulic performance characteristics of SAH have been compared with the previous published works and the optimum range of the geometries have been explored for the better performance of such air-heaters compared to the other designs of solar air heaters

  13. Evaluation of air jet erosion profiles in metal mesh supported SCR plate catalyst based on glass fiber concentrations

    Science.gov (United States)

    Rajath, S.; Nandakishora, Y.; Siddaraju, C.; Roy, Sukumar

    2018-04-01

    This paper explains the evaluation of erosion profiles in metal mesh supported SCR plate catalyst structures in which the glass fibers concentration in the catalyst material is considered as prime factor for erosion resistance and mechanical strength. The samples are prepared and tested at the specified and constant conditions like velocity as 30m/s, sand flow rate as 2g/min, average particle diameter 300 µm and all these samples were tested at different angles at impact preferably 15°,30°,45°,60°,75°,and 90° as per ASTM G76 standards. Say, if 5% glass fibers are present in catalyst material, then erosion resistance increases, but the density of glass fibers is very less because each glass fiber is approximately 20 microns in diameter and weight of individual is negligible. The composition in which 2% fiber is present has slightly higher erosion comparatively, but 3% glass fibers or more foreign inclusion like excessive binders can be eliminated that contributes much for the conversion of NOx. So 2% -3% glass fibers are preferred and optimized based on NOx conversion and erosion resistance property.

  14. Visualization study of interaction with 2-D film flow on the vertical plate and lateral air velocity for DVI system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Han Sol; Lee, Jae Young [Handong Global University, Pohang (Korea, Republic of); Euh, Dong Jin; Kim, Jong Rok [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    The present study investigates liquid film flow generated in a downcomer of direct vessel injection (DVI) system which is employed as an emergency core cooling (ECC) system during a loss of coolant accident in the Korea nuclear power plant APR1400. During the late reflooding, complicated multi-phase flow phenomena including the wavy film flow, film breakup, entrainment, liquid film shift due to interfacial drag and gas jet impingement occur. In order to obtain a proper scaling law of the flow, local information of the flow was investigated experimentally and also numerically. A series of experiments were conducted in the 1/20 modified linear scaled plate type test rig to analyze a liquid film from ECC water injection through the DVI nozzle to the downcomer wall. A confocal chromatic sensor was used to measure the local instantaneous liquid film thickness. In this study, the average flow information of the downcomer was analyzed through the information about the thickness, speed, droplet size and speed of highly precise liquid film flow in the structure that occurs in a 2-dimensional liquid film flow, rather than film flow, onset of entrainment, droplet velocity, and size which have been studied in 1-dimension of the existing annular flow. The multi-dimensional flow characteristic information of downcomer can be utilized as the basic data for nuclear safety analysis in the future.

  15. CISBAT 2007 - Solar collectors (heat and electricity)

    International Nuclear Information System (INIS)

    2007-01-01

    This is the third part of the proceedings of the 2007 CISBAT conference on Renewables in a changing climate, held in Lausanne, Switzerland. On the subject of Building and urban integration of renewables the following oral contributions are summarised: 'Facade integration of solar thermal collectors: present and future', 'Long term experiences with a versatile PV in roof system', 'Development of a design and performance prediction tool for the ground source heat pump and underground thermal storage system', 'Hygrothermal performance of earth-to-air heat exchanger: long-term data evaluation and short-term simulation' as well as 'The real cost of heating your home: a comparative assessment of home energy systems with external costs'. Poster-sessions on the subject include 'Central solar heating plants with seasonal heat storage', 'Analysis of forced convection for evaporative air flow and heat transfer in PV cooling channels', 'Renewable energy technology in Mali: constraints and options for a sustainable development', 'Effect of duct width in ducted photovoltaic facades', 'Design and actual measurement of a ground source heat pump system using steel foundation piles as ground heat exchangers', 'Development of an integrated water-water heat pump unit for low energy house and its application', 'PV effect in multilayer cells and blending of fullerene/poly (3-hexylthiophene) and phthalocyanine having NIR charge transfer absorption band', 'CdTe photovoltaic systems - an alternative energetic', 'Integration of renewable energy sources in a town, examples in Grenoble', 'A prospective analysis method for the conception of solar integration solutions in buildings' and 'Energy and aesthetic improvements for building integration of cost effective solar energy systems'. Further groups of presentations at the conference are reported on in separate database records. An index of authors completes the proceedings

  16. Standard Practice for Exposure of Cover Materials for Solar Collectors to Natural Weathering Under Conditions Simulating Operational Mode

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1995-01-01

    1.1 This practice provides a procedure for the exposure of cover materials for flat-plate solar collectors to the natural weather environment at temperatures that are elevated to approximate operating conditions. 1.2 This practice is suitable for exposure of both glass and plastic solar collector cover materials. Provisions are made for exposure of single and double cover assemblies to accommodate the need for exposure of both inner and outer solar collector cover materials. 1.3 This practice does not apply to cover materials for evacuated collectors or photovoltaics. 1.4 The values stated in SI units are to be regarded as the standard. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  17. Cold plate

    Energy Technology Data Exchange (ETDEWEB)

    Marroquin, Christopher M.; O' Connell, Kevin M.; Schultz, Mark D.; Tian, Shurong

    2018-02-13

    A cold plate, an electronic assembly including a cold plate, and a method for forming a cold plate are provided. The cold plate includes an interface plate and an opposing plate that form a plenum. The cold plate includes a plurality of active areas arranged for alignment over respective heat generating portions of an electronic assembly, and non-active areas between the active areas. A cooling fluid flows through the plenum. The plenum, at the non-active areas, has a reduced width and/or reduced height relative to the plenum at the active areas. The reduced width and/or height of the plenum, and exterior dimensions of cold plate, at the non-active areas allow the non-active areas to flex to accommodate surface variations of the electronics assembly. The reduced width and/or height non-active areas can be specifically shaped to fit between physical features of the electronics assembly.

  18. Single-stage depressed collectors for gyrotrons

    International Nuclear Information System (INIS)

    Piosczyk, B.; Iatrou, C.T.; Dammertz, G.; Thumm, M.; Univ. Karlsruhe

    1996-01-01

    Two 140 GHz gyrotrons with a single-step depressed collector have been operated. The different position of the isolating collector gap in the stray magnetic field causes the electron motion in the retarding region to be in one case adiabatic and in the other case nonadiabatic. The kind of motion within the retarding field influences strongly the behavior of the gyrotron with a depressed collector. In the case of nonadiabatic motion a significant amount of transverse momentum is given to the electrons reflected at the collector potential. This causes the reflected electrons to be trapped between the magnetic mirror and the collector. The electrons escape from the trap by diffusion across the magnetic field to the body of the tube thus contributing to the body current. Despite the high body current there is no observable influence of the collector voltage on the RF output power. In the case of adiabatic motion the reflected electrons do not gain a sufficient amount of transverse momentum to be trapped by the magnetic mirror. They pass the cavity toward the gun and they are trapped between the negative gun potential and the collector. The interaction with the RF field by electrons traveling through the cavity enhances the diffusion in the velocity space thus enabling the trapped electrons to overcome the potential barrier and escape toward the collector. Therefore the body current stays at low values since in this case the reflected electrons do not contribute to it. However, at higher collector voltages a reduction of RF power occurred and some noise in the electron beam was observed. The main motivation for the development of gyrotrons in the frequency range above 100 GHz with power levels in excess of several hundreds kW per tube, is the application in magnetic fusion devices for plasma heating and for electron current drive

  19. Plating laboratory

    International Nuclear Information System (INIS)

    Seamster, A.G.; Weitkamp, W.G.

    1984-01-01

    The lead plating of the prototype resonator has been conducted entirely in the plating laboratory at SUNY Stony Brook. Because of the considerable cost and inconvenience in transporting personnel and materials to and from Stony Brook, it is clearly impractical to plate all the resonators there. Furthermore, the high-beta resonator cannot be accommodated at Stony Brook without modifying the set up there. Consequently the authors are constructing a plating lab in-house

  20. Engineering design of 500KW CW collector

    International Nuclear Information System (INIS)

    Kumar, Ramesh; Mishra, Deepak; Prasad, M.; Hannuarakar, P.R.

    2006-01-01

    An electron beam collector for 500kW beam power has been designed to test the electron gun. The gun is designed for 250kW, 350MHz CW Klystron with 50% efficiency. This will also help in preliminary studies related to final collector design for Klystron. This paper presents the design parameters, thermal analysis and mechanical features of the design. Electron trajectory on inside wall of the collector is determined with EGUN and computational flow dynamics simulation was done on ANSYS for cooling requirements. (author)

  1. Next Generation Solar Collectors for CSP

    Energy Technology Data Exchange (ETDEWEB)

    Molnar, Attila [3M Company, St. Paul, MN (United States); Charles, Ruth [3M Company, St. Paul, MN (United States)

    2014-07-31

    The intent of “Next Generation Solar Collectors for CSP” program was to develop key technology elements for collectors in Phase 1 (Budget Period 1), design these elements in Phase 2 (Budget Period 2) and to deploy and test the final collector in Phase 3 (Budget Period 3). 3M and DOE mutually agreed to terminate the program at the end of Budget Period 1, primarily due to timeline issues. However, significant advancements were achieved in developing a next generation reflective material and panel that has the potential to significantly improve the efficiency of CSP systems.

  2. Effect of Installation of Solar Collector on Performance of Balcony Split Type Solar Water Heaters

    Directory of Open Access Journals (Sweden)

    Xu Ji

    2015-01-01

    Full Text Available The influences of surface orientation and slope of solar collectors on solar radiation collection of balcony split type solar water heaters for six cities in China were analyzed by employing software TRNSYS. The surface azimuth had greater effect on solar radiation collection in high latitude regions. For deviation of the surface slope angle within ±20° around the optimized angle, the variation of the total annual collecting solar radiation was less than 5%. However, with deviation of 70° to 90°, the variation was up to 20%. The effects of water cycle mode, reverse slope placement of solar collector, and water tank installation height on system efficiency were experimentally studied. The thermal efficiencies of solar water heater with single row horizontal arrangement all-glass evacuated tubular collector were higher than those with vertical arrangement at the fixed surface slope angle of 90°. Compared with solar water heaters with flat-plate collector under natural circulation, the system thermal efficiency was raised up to 63% under forced circulation. For collector at reverse slope placement, the temperature-based water stratification in water tank deteriorated, and thus the thermal efficiency became low. For improving the system efficiency, an appropriate installation height of the water tank was suggested.

  3. Photovoltaic-thermal (PV/T) solar collectors: Features and performance modelling

    International Nuclear Information System (INIS)

    Atienza-Márquez, Antonio; Bruno, Joan Carles; Coronas, Alberto; Korolija, Ivan; Greenough, Richard; Wright, Andy

    2017-01-01

    Currently, the electrical efficiency of photovoltaic (PV) solar cells ranges between 5–25%. One of the most important parameters that affects the electrical efficiency of a PV collector is the temperature of its cells: the higher temperature, the lower is the efficiency. Photovoltaic/thermal (PV/T) technology is a potential solution to ensure an acceptable solar energy conversion. The PV/T technology produces both electrical and thermal energy simultaneously. It is suitable for low temperature applications (25–40 o C) and overall efficiency increases compared to individual collectors. This paper describes an installation in a single-family house where PV/T collectors are coupled with a ground heat exchanger and a heat pump for domestic hot water and space heating purposes. The aim of this work is twofold. First, the features of the PV/T technology are analyzed. Second, a model of a flat-plate PV/T water collector was developed in TRNSYS in order to analyze collectors performance. (author)

  4. A new concept of hybrid photovoltaic thermal (PVT) collector with natural circulation

    Science.gov (United States)

    Lu, Longsheng; Wang, Xiaowu; Wang, Shuai; Liu, Xiaokang

    2017-07-01

    Hybrid photovoltaic thermal (PVT) technology refers to the integration of a photovoltaic module into a conventional solar thermal collector. Generally, the traditional design of a PVT collector has solar cells fixed on the top surface of an absorber in a flat-plate solar thermal collector. In this work, we presented a new concept of water-based PVT collector in which solar cells were directly placed on the bottom surface of its glass cover. A dynamic numerical model of this new PVT is developed and validated by experimental tests. With numerical analysis, it is found that at same covering factor, the electricity conversion efficiency of solar cells of the new PVT exceed that of the traditional PVT by nearly 10% while its thermal efficiency is approximately 30% lower than that of the traditional PVT. When the covering factor changes from 0.05 to 1, the thermal efficiency of the new PVT drops nearly 70%. The thermal efficiency of both the new PVT and the traditional PVT rise up as the water mass in tank increases. Meanwhile, the final water temperature in tank of the traditional PVT collector declines more than 17 °C, whereas that of the new PVT declines less than 6 °C, when the water mass increases from 100 to 300 kg.

  5. Improved Large Aperture Collector Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    O' Rourke, Deven [Abengoa Solar LLC, Lakewood, CO (United States); Farr, Adrian [Abengoa Solar LLC, Lakewood, CO (United States)

    2015-12-01

    The parabolic trough is the most established CSP technology and carries a long history of design experimentation dating back to the 1970’s. This has led to relatively standardized collector architectures, a maturing global supply chain, and a fairly uniform cost reduction strategy. Abengoa has deployed more than 1,500MWe of CSP troughs across several countries and has built and tested full-scale prototypes of many R&D concepts. The latest trough R&D efforts involved efforts to internalize non-CSP industry experience including a preliminary DFMA principles review done with Boothroyd Dewhurst, a construction literature review by the Arizona State University School of Construction Management, and two more focused manufacturing engineering subcontracts done by Ricardo Inc. and the nonprofit Edison Welding Institute. The first two studies highlighted strong opportunities in lowering part count, standardizing components and fasteners, developing modular designs to support prefabrication and automation, and devising simple, error-proof manual assembly methods. These principles have delivered major new cost savings in otherwise “mature” products in analogous industries like automotive, truck trailer manufacture, metal building fabrication, and shipbuilding. For this reason, they were core in the design development of the SpaceTube® collector, and arguably key to its early successes. The latter two studies were applied specifically to the first-generation SpaceTube® design and were important in setting the direction of the present SolarMat project. These studies developed a methodology to analyze the costs of manufacture and assembly, and identify new tooling concepts for more efficient manufacture. Among the main opportunities identified in these studies were the automated mirror arm manufacturing concept and the need for a less infrastructure-intensive assembly line, both of which now form central pillars of the SolarMat project strategy. These new designs will be

  6. Potential Evaluation of Solar Heat Assisted Desiccant Hybrid Air Conditioning System

    Science.gov (United States)

    Tran, Thien Nha; Hamamoto, Yoshinori; Akisawa, Atsushi; Kashiwagi, Takao

    The solar thermal driven desiccant dehumidification-absorption cooling hybrid system has superior advantage in hot-humid climate regions. The reasonable air processing of desiccant hybrid air conditioning system and the utility of clean and free energy make the system environment friendly and energy efficient. The study investigates the performance of the desiccant dehumidification air conditioning systems with solar thermal assistant. The investigation is performed for three cases which are combinations of solar thermal and absorption cooling systems with different heat supply temperature levels. Two solar thermal systems are used in the study: the flat plate collector (FPC) and the vacuum tube with compound parabolic concentrator (CPC). The single-effect and high energy efficient double-, triple-effect LiBr-water absorption cooling cycles are considered for cooling systems. COP of desiccant hybrid air conditioning systems are determined. The evaluation of these systems is subsequently performed. The single effect absorption cooling cycle combined with the flat plate collector solar system is found to be the most energy efficient air conditioning system.

  7. Development of a Direct Methanol Fuel Cell with Lightweight Disc Type Current Collectors

    Directory of Open Access Journals (Sweden)

    Yean-Der Kuan

    2014-05-01

    Full Text Available The direct methanol fuel cell (DMFC adopts methanol solution as a fuel suitable for low power portable applications. A miniature, lightweight, passive air-breathing design is therefore desired. This paper presents a novel planar disc-type DMFC with multiple cells containing a novel developed lightweight current collector at both the anode and cathode sides. The present lightweight current collector adopts FR4 Glass/Epoxy as the substrate with the current collecting areas located at the corresponding membrane electrolyte assembly (MEA areas. The current collecting areas are fabricated by sequentially coating a corrosion resistant layer and electrical conduction layer via the thermal evaporation technique. The anode current collector has carved flow channels for fuel transport and production. The cathode current collector has drilled holes for passive air breathing. In order to ensure feasibility in the present concept a 3-cell prototype DMFC module with lightweight disc type current collectors is designed and constructed. Experiments were conducted to measure the cell performance. The results show that the highest cell power output is 54.88 mW·cm−2 and successfully demonstrate the feasibility of this novel design.

  8. Development and calibration of a ground-based active collector for cloud- and fogwater

    Energy Technology Data Exchange (ETDEWEB)

    Kins, L.; Junkermann, W.; Meixner, F.X.; Muller, K.P.; Ehhalt, D.H.

    1986-04-01

    In spring 1985, field experiments were started to study the scavenging processes of atmospheric trace substances. Besides the chemical analysis of precipitation sample, these studies required simultaneous collection of cloud water for chemical analysis. In particular, a ground-based cloud water collector was needed, suitable for use on the top of a TV-tower. Existing designs of ground-based cloud or fogwater samplers be divided into two general classes: a) passive collectors, which utilize the ambient wind to impact the droplets on the collection surface; b) active collectors, which accelerate the droplets to a certain velocity as they approach the collection surface. Teflon-strings are extended between two disks which are 1m apart. The disadvantage of this collector, for these experiments, was that the collector strings are always exposed to the ambient air, so that contamination by aerosol impact during dry periods can not be excluded. Furthermore, because of the length of the strings, impacted droplets need a certain time to drain off, during which they remain exposed to the ambient air stream and continue to scavenge trace gases.

  9. Design and fabrication of light weight current collectors for direct methanol fuel cells using the micro-electro mechanical system technique

    Science.gov (United States)

    Sung, Min-Feng; Kuan, Yean-Der; Chen, Bing-Xian; Lee, Shi-Min

    The direct methanol fuel cell (DMFC) is suitable for portable applications. Therefore, a light weight and small size is desirable. The main objective of this paper is to design and fabricate a light weight current collector for DMFC usage. The light weight current collector mainly consists of a substrate with two thin film metal layers. The substrate of the current collector is an FR4 epoxy plate. The thin film metal layers are accomplished by the thermo coater technique to coat metal powders onto the substrate surfaces. The developed light weight current collectors are further assembled to a single cell DMFC test fixture to measure the cell performance. The results show that the proposed current collectors could even be applied to DMFCs because they are light, thin and low cost and have potential for mass production.

  10. Calculation of the Arc Velocity Along the Polluted Surface of Short Glass Plates Considering the Air Effect

    Directory of Open Access Journals (Sweden)

    Tao Yuan

    2012-03-01

    Full Text Available To investigate the microphysics mechanism and the factors that influence arc development along a polluted surface, the arc was considered as a plasma fluid. Based on the image method and the collision ionization theory, the electric field of the arc needed to maintain movement with different degrees of pollution was calculated. According to the force of the charged particle in an arc plasma stressed under an electric field, a calculation model of arc velocity, which is dependent on the electric field of the arc head that incorporated the effects of airflow around the electrode and air resistance is presented. An experiment was carried out to measure the arc velocity, which was then compared with the calculated value. The results of the experiment indicated that the lighter the pollution is, the larger the electric field of the arc head and arc velocity is; when the pollution is heavy, the effect of thermal buoyancy that hinders arc movement increases, which greatly reduces the arc velocity.

  11. Energy and exergy analysis of a two pass photovoltaic –thermal (PV/T) air heater

    Energy Technology Data Exchange (ETDEWEB)

    Srinivas, M.; Jayaraj, S. [Department of Mechanical Engineering, National Institute of Technology, Calicut-673601 (India)

    2013-07-01

    A double pass hybrid solar air (PV/T) heater with slats is designed and fabricated to study elaborately its thermal and electrical performance corresponding to the warm and humid environment. Air as a heat removing fluid is made to flow through upper and lower channels of the collector. The collector is designed in such way that the absorber plate is partially covered by solar cells. Thin metallic strips (called slats) are attached longitudinally at the bottom side of the absorber plate to improve the overall system performance (by increasing the cooling rate of the absorber plate). Thermal and electrical performances of the whole system at different cooling rates are presented. The exergy analysis of double pass hybrid solar air (PV/T) heater with slats has also been carried out. The instantaneous overall energy and overall exergy efficiency of the double pass hybrid (PV/T) solar air heater varies between 29 – 37 percent and 14-17 percent respectively. These obtained values are comparable with that of published results.

  12. A novel design for a cheap high temperature solar collector: The rotating solar boiler

    NARCIS (Netherlands)

    Luijtelaer, van J.P.H.; Kroon, M.C.

    2009-01-01

    In this work a novel type of high temperature solar collector is designed: the rotating solar boiler. This rotating solar boiler consists of two concentric tubes. The inner tube, called absorber, absorbs sunlight and boils water. The outer transparent tube, called cover, is filled with air. The

  13. Collector sealants and breathing. Final Report, 25 September 1978-31 December 1979

    Energy Technology Data Exchange (ETDEWEB)

    Mendelsohn, M A; Luck, R M; Yeoman, F A; Navish, Jr, F W

    1980-02-20

    The objectives of this program were: (1) to investigate the pertinent properties of a variety of possible sealants for solar collectors and identify the most promising candidates, and (2) to study the effect of breathing in flat-plate, thermal solar collector units. The study involved two types of sealants, Class PS which includes preformed seals or gaskets and Class SC which includes sealing compounds or caulks. It was the intent of the study to obtain data regarding initial properties of candidate elastomers from manufacturers and from the technical literature and to use those sources to provide data pertaining to endurance of these materials under environmental service conditions. Where necessary, these data were augmented by experimental measurements. Environmental stresses evaluated by these measurements included elevated temperatures, moisture, ultraviolet light, ozone and oxygen, and fungus. The second major area of the work involved a study of the effects of materials used and design on the durability of solar collectors. Factors such as design, fabrication, materials of construction, seals and sealing techniques and absorber plate coatings were observed on actual field units removed from service. Such phenomena as leakage, corrosion and formation of deposits on glazing and absorber plate were noted. An evaluation of the properties of several desiccants was made in order to providemeans to mitigate the deleterious effects of water on collector life. Adsorbents for organic degradation products of sealants were also investigated in order to protect the glazing and absorber plate from deposited coatings. Since adsorbents and desiccants in general tend to take up both water and organic decomposition products, relative affinities of a number of these agents for water and for organic compounds were determined . Results are presented in detail.

  14. Thermal analysis of a solar collector consisting of V cavities for water heating; Analise termica de um coletor solar composto de cavidades V para aquecimento de agua

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Michel Fabio de Souza

    2009-03-15

    The solar water heating is carried through, in Brazil, by means of solar heaters compound for collectors flat plate of the type plate-and-pipes, devices that operate in stationary position and they do not require tracking of the sun. A compound collector for some formed V-trough concentrators can be an alternative to the conventional solar collectors flat plate. This compound collector for V-trough is considered, each one, for side-walls which are specularly reflecting surfaces associates in V (equivalent to a triangular gutter). Next to the vertex to each V-trough concentrators an absorber tube is fixed, for flow of the fluid to be heated. Interconnection of the absorbers tubes forms a similar tubular network existing in solar collectors of the type the plate and pipe. V-trough concentrators with the absorbers tubes are made use in series in the interior a prismatic box, which have one of its faces consisting by a glass covering and directed toward incidence of the solar radiation. An analysis of thermal performance of these devices operating stationary and without tracking of the sun is researched. A mathematical model for the computational simulation of the optical and thermal performance of these concentrative devices is elaborated, whose implementation was carried through software EES (Engineering Equation Solver). The efficiency optics of V-trough concentrators with cylindrical absorbers is calculated from the adaptation of the methodology used for Fraidenraich (1994), proposal for Hollands (1971) for V-trough cavities with plain absorbers. The thermal analysis of the considered collector was based on the applied methodology the CPC for Hsieh (1981) and Leao (1989). Relative results to the thermal performance of V-trough concentrators suggest that these configurations are not competitive, technique and economically, with the conventional plain collectors. Although some geometric configurations presented next thermal efficiencies to the conventional plain

  15. Solar energy collector/storage system

    Energy Technology Data Exchange (ETDEWEB)

    Bettis, J.R.; Clearman, F.R.

    1983-05-24

    A solar energy collector/storage system which includes an insulated container having working fluid inlets and outlets and an opening, a light-transmitting member positioned over the opening, and a heat-absorbing member which is centrally situated, is supported in the container, and is made of a mixture of gypsum , lampblack, and water. A light-reflecting liner made of corrugated metal foil preferably is attached to the internal surface of the container. The opening of the container is positioned in optical alignment with a source of solar energy. A light-reflecting cover optionally can be hingedly attached to the container, and can be positioned such as to reflect solar energy rays into the container. The system is adaptable for use with a working gas (e.g., air) and/or a working liquid (e.g., water) in separated flows which absorb heat from the heat-absorbing member, and which are useable per se or in an associated storage and/or circulatory system that is not part of this invention. The heatabsorbing mixture can also contain glass fibers. The heatabsorbing member is of such great load-bearing strength that it can also be used simultaneously as a structural member, e.g., a wall or ceiling of a room; and, thereby, the system can be used to heat a room, if a window of the room is the light-transmitting member and is facing the sun, and if the heat-absorbing member is a wall and/or the ceiling of the room and receives solar energy through the window.

  16. An investigation of heat transfer augmentation and friction characteristics in solar air heater duct with V-shaped wire as artificial roughness on absorber plate

    Energy Technology Data Exchange (ETDEWEB)

    Madhukeshwara, N. [Department of Mechanical Engineering, B.I.E.T, Davanagere, Karnataka (India); Prakash, E.S. [Department of Studies in Mechanical Engineering, U.B.D.T.C.E, Davanagere, Karnataka (India)

    2013-07-01

    An experimental investigation of heat transfer augmentation and friction characteristics of fully developed turbulent flow in a rectangular duct of solar air heater with absorber plate having V-shaped wire ribs as artificial roughness on its underside is carried out. The investigation covers wide range of different parameters of wire ribbed roughness: relative roughness pitch (p/e) from 10 to 40, relative roughness height (e/Dh) from 0.01 to 0.04 and angle of attack of flow from 20° to 90°. Duct aspect ratio (W/B) is kept 5 and Reynolds number (Re) is varied from 2,500 to 8,500. The heat transfer and friction factor values obtained are compared with those of smooth duct under similar flow conditions. Expressions are developed for Nusselt number and friction factor for the roughness geometry. Enhancement of Nusselt number and friction factor for roughened duct are 1.5 and 2.7 times of smooth duct respectively.

  17. Investigating the collector efficiency of silver nanofluids based direct absorption solar collectors

    International Nuclear Information System (INIS)

    Chen, Meijie; He, Yurong; Zhu, Jiaqi; Wen, Dongsheng

    2016-01-01

    Highlights: • An analysis coupled with Radiation transfer, Maxwell and Energy equation is developed. • Plasmonic Au and Ag nanofluids show better photo-thermal conversion properties. • Collector height and particle concentration exist optimum solutions for efficiency. - Abstract: A one-dimensional transient heat transfer analysis was carried out to analyze the effects of the Nanoparticle (NP) volume fraction, collector height, irradiation time, solar flux, and NP material on the collector efficiency. The numerical results were compared with the experimental results obtained by silver nanofluids to validate the model, and good agreement was obtained. The numerical results show that the collector efficiency increases as the collector height and NP volume fraction increase and then reaches a maximum value. An optimum collector height (∼10 mm) and particle concentration (∼0.03%) achieving a collector efficiency of 90% of the maximum efficiency can be obtained under the conditions used in the simulation. However, the collector efficiency decreases as the irradiation time increases owing to the increased heat loss. A high solar flux is desirable to maintain a high efficiency over a wide temperature range, which is beneficial for subsequent energy utilization. The modeling results also show silver and gold nanofluids obtain higher photothermal conversion efficiencies than the titanium dioxide nanofluid because their absorption spectra are similar to the solar radiation spectrum.

  18. Two new designs of parabolic solar collectors

    Directory of Open Access Journals (Sweden)

    Karimi Sadaghiyani Omid

    2014-01-01

    Full Text Available In this work, two new compound parabolic trough and dish solar collectors are presented with their working principles. First, the curves of mirrors are defined and the mathematical formulation as one analytical method is used to trace the sun rays and recognize the focus point. As a result of the ray tracing, the distribution of heat flux around the inner wall can be reached. Next, the heat fluxes are calculated versus several absorption coefficients. These heat flux distributions around absorber tube are functions of angle in polar coordinate system. Considering, the achieved heat flux distribution are used as a thermal boundary condition. After that, Finite Volume Methods (FVM are applied for simulation of absorber tube. The validation of solving method is done by comparing with Dudley's results at Sandia National Research Laboratory. Also, in order to have a good comparison between LS-2 and two new designed collectors, some of their parameters are considered equal with together. These parameters are consist of: the aperture area, the measures of tube geometry, the thermal properties of absorber tube, the working fluid, the solar radiation intensity and the mass flow rate of LS-2 collector are applied for simulation of the new presented collectors. After the validation of the used numerical models, this method is applied to simulation of the new designed models. Finally, the outlet results of new designed collector are compared with LS-2 classic collector. Obviously, the obtained results from the comparison show the improving of the new designed parabolic collectors efficiency. In the best case-study, the improving of efficiency are about 10% and 20% for linear and convoluted models respectively.

  19. Air-cooled, hydrogen-air fuel cell

    Science.gov (United States)

    Shelekhin, Alexander B. (Inventor); Bushnell, Calvin L. (Inventor); Pien, Michael S. (Inventor)

    1999-01-01

    An air-cooled, hydrogen-air solid polymer electrolyte (SPE) fuel cell with a membrane electrode assembly operatively associated with a fluid flow plate having at least one plate cooling channel extending through the plate and at least one air distribution hole extending from a surface of the cathode flow field into the plate cooling channel.

  20. Experimental investigation on the performance of an impinging jet solar air heater

    Directory of Open Access Journals (Sweden)

    T. Rajaseenivasan

    2017-03-01

    Full Text Available Investigation on an impinging jet solar air heater is performed and reported in this work. The air is supplied through an impinging jet pipe which contains the nozzles to distribute the air in the solar air heater. The air is released from the jet strikes the absorber plate which increases the heat transfer rate by creating turbulent flow in the collector. This study is focused on the parameters that affect the heat transfer characteristics and compared with conventional solar air heater. The system is examined by varying the angle of attack (0°, 10°, 20°, 30°, 60° and 90° and the nozzle diameter (3 mm, 5 mm and 7 mm in the air mass flow rate range of 0.012–0.016 kg/s. The study revealed that the highest performance is achieved with the 30° angle of attack, and the lowest performance is recorded with the 0°. The reduction in jet diameter increases the pressure loss in the collector. The better system performance is observed with the 5 mm diameter hole. The maximum thermal enhancement factor of 2.19 and efficiency of 55.8% are reached with the flow rate of 0.016 kg/s.

  1. Performance of a Solar Heating System with Photovoltaic Thermal Hybrid Collectors and Heat Pump

    DEFF Research Database (Denmark)

    Dannemand, Mark; Furbo, Simon; Perers, Bengt

    2017-01-01

    . When the solar collectors are unable to supply the heat demand an auxiliary heat source is used. Heat pumps can generate this heat. Liquid/water heat pumps have better performance than air/water heat pumps in cold climates but requires installation of a tubing system for the cold side of the heat pump....... The tubes are typically placed in the ground, requires a significant land area and increase the installation cost. A new system design of a solar heating system with two storage tanks and a liquid/water heat pump is presented. The system consists of PVT collectors that generate both heat and electricity......The energy consumption in buildings accounts for a large part of the World’s CO2 emissions. Much energy is used for appliances, domestic hot water preparation and space heating. In solar heating systems, heat is captured by solar collectors when the sun is shining and used for heating purposes...

  2. Efficiency of the Fermilab Electron Cooler's Collector

    CERN Document Server

    Prost, L R

    2005-01-01

    The newly installed high-energy Recycler Electron Cooling system (REC) at Fermilab will work at an electron energy of 4.34 MeV and a DC beam current of 0.5 A in an energy recovery scheme. For reliable operation of the system, the relative beam current loss must be maintained to levels < 3.e-5. Experiments have shown that the loss is determined by the performance of the electron beam collector, which must retain secondary electrons generated by the primary beam hitting its walls. As a part of the Electron cooling project, the efficiency of the collector for the REC was optimized, both with dedicated test bench experiments and on two versions of the cooler prototype. We find that to achieve the required relative current loss, an axially-symmetric collector must be immersed in a transverse magnetic field with certain strength and gradient prescriptions. Collector efficiencies in various magnetic field configurations, including without a transverse field on the collector, are presented and discussed

  3. Tube collector with integrated tracking parabolic concentrator

    Energy Technology Data Exchange (ETDEWEB)

    Grass, C.; Benz, N.; Hacker, Z.; Timinger, A. [ZAE Bayern, Bavarian Centre for Applied Energy Research, Muenchen (Germany)

    2000-07-01

    Low concentrating CPC collectors usually do not track the sun and are mounted in east-west direction with a latitude dependent slope angle. They are most suitable for maximum working temperatures up to 200 250 deg. C. We present a novel evacuated tube-collector with a trough-like concentrating mirror. Single-axis tracking of the mirror is realized with a magnetic mechanism. The mirror is mounted inside the evacuated tube and hence protected from environmental influences. One axis tracking in combination with a small acceptance angle allows for higher concentration as compared to non-tracking concentrating collectors. Ray-tracing analysis shows a half acceptance angle of about 5 deg. at a geometrical concentration ratio of 3.2. The losses of evacuated tube collectors are dominated by the radiation losses of the absorber. Hence, reducing the absorber size can lead to higher efficiencies at high operating temperature levels. With the presented collector we aim for operating temperatures up to 400 deg. C. At temperatures of 300 deg. C we expect efficiencies of 65 %. This allows for application in industrial process heat generation, high efficient solar cooling and power generation. A first prototype was tested at the ZAE Bayern. The optical efficiency was measured to be 75 %. (au)

  4. Dynamic testing of solar collectors under special consideration of the correction of the inclination angle and reduction of the test duration; Dynamische Pruefung von Sonnenkollektoren unter besonderer Beruecksichtigung der Einfallswinkelkorrektur und der Reduzierung der Pruefdauer

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Stephan

    2011-07-01

    Solar thermal systems are gaining more and more market shares. At the beginning of the last decade only systems for swimming pool heating and domestic hot water heating were available on the market. Today the system variety includes additionally solar thermal systems for space heating, solar thermal cooling, process heat and solar thermal power plants. Independent of the purpose of the solar thermal system, it is always the collector that converts the solar irradiance into heat and is thus the most important component within a solar thermal system. The high number of applications results also in a large variety of different collector concepts. The differences between flat plate collectors, evacuated tubular collectors (with or without heat pipes). CPC collectors, parabolic trough collectors. Fresnel collectors and others is not limited to geometry and working principles but include as well the thermal performance, especially when the thermal behaviour under different angles of incidence and fractions of diffuse irradiance is taking into account. For the test of solar thermal collectors and for the optimisation of solar thermal systems a mathematical model is necessary to describe the thermal performance of the solar collector. Thus this thesis is dealing with the mathematic modelling and the experimental testing of solar thermal collectors. Based on already existing procedures a numerical model and a new procedure for the test of thermal collectors is introduced. The numerical model enables the description of the thermal behaviour for most collectors available on the market. The numerical model and the test procedure were developed paying special attention to the incidence angle modifier and the reduction of testing time. As basis for the general numerical model and the test procedure part one of the thesis describes and discusses the parameters needed to characterise the thermal performance of solar thermal collectors. It is shown that some of the influencing

  5. Performance optimization of evacuated tube collector for solar cooling of a house in hot climate

    Science.gov (United States)

    Ghoneim, Adel A.

    2018-02-01

    Evacuating the space connecting cover and absorber significantly improves evacuated tube collector (ETC) performance. So, ETCs are progressively utilised all over the world. The main goal of current study is to explore ETC thermal efficiency in hot and severe climate like Kuwait weather conditions. A collector test facility was installed to record ETC thermal performance for one-year period. An extensively developed model for ETCs is presented, employing complete optical and thermal assessment. This study analyses separately optics and heat transfer in the evacuated tubes, allowing the analysis to be extended to different configurations. The predictions obtained are in agreement with experimental. The optimum collector parameters (collector tube length and diameter, mass flow rate and collector tilt angle) are determined. The present results indicate that the optimum tube length is 1.5 m, as at this length a significant improvement is achieved in efficiency for different tube diameters studied. Finally, the heat generated from ETCs is used for solar cooling of a house. Results of the simulation of cooling system indicate that an ETC of area 54 m2, tilt angle of 25° and storage tank volume of 2.1 m3 provides 80% of air-conditioning demand in a house located in Kuwait.

  6. Plating on Zircaloy-2

    International Nuclear Information System (INIS)

    Dini, J.W.; Johnson, H.R.; Jones, A.

    1979-03-01

    Zircaloy-2 is a difficult alloy to coat with an adherent electroplate because it easily forms a tenacious oxide film in air and aqueous solutions. Procedures reported in the literature and those developed at SLL for surmounting this problem were investigated. The best results were obtained when specimens were first etched in either an ammonium bifluoride/sulfuric acid or an ammonium bifluoride solution, plated, and then heated at 700 0 C for 1 hour in a constrained condition. Machining threads in the Zircaloy-2 for the purpose of providing sites for mechanical interlocking of the plating also proved satisfactory

  7. Optimum solar collector fluid flow rates

    DEFF Research Database (Denmark)

    Furbo, Simon; Shah, Louise Jivan

    1996-01-01

    Experiments showed that by means of a standard electronically controlled pump, type UPE 2000 from Grundfos it is possible to control the flow rate in a solar collector loop in such a way that the flow rate is strongly influenced by the temperature of the solar collector fluid passing the pump....... The flow rate is increasing for increasing temperature.The flow rate at the high temperature level is typically 70 % greater than the flow rate at the low temperature level.Further, the energy consumption for the electronically controlled pump in a solar heating system will be somewhat smaller than...... the energy consumption of a normal ciculation pump in the solar heating system.Calculations showed that the highest thermal performances for small SDHW systems based on mantle tanks with constant volume flow rates in the solar collector loops are achieved if the flow rate is situated in the interval from 0...

  8. Investigations on the performance of a double pass, hybrid - type (PV/T) solar air heater

    Energy Technology Data Exchange (ETDEWEB)

    Srinivas, M.; Jayaraj, S. [Department of Mechanical Engineering, National Institute of Technology, Calicut-673601 (India)

    2013-07-01

    A solar hybrid energy system having photovoltaic and thermal (PV/T) devices, which produces both thermal and electrical energies simultaneously is considered for analysis. A double pass hybrid solar air (PV/T) heater with slats is designed and fabricated to study its thermal and electrical performance. Air as a heat removing fluid is made to flow through upper and lower channels of the collector. The collector is designed in such a way that the absorber plate is partially covered by solar cells. The raise in temperature of the solar cell is expected to decrease its electrical performance. Thin metallic strips called slats are attached longitudinally at the bottom side of the absorber plate to improve the system performance by increasing the cooling rate of the absorber plate. Thermal and electrical performances of the whole system at varying cooling conditions are presented. An artificial neural network model is used for forecasting the system performance at any desired conditions. The proposed model can be successfully used for evaluating the effect of different operating parameters under different ambient conditions for predicting the overall performance of the system.

  9. Experimental analysis of distinct design of a batch solar water heater with integrated collector storage system

    Directory of Open Access Journals (Sweden)

    Varghese Jaji

    2007-01-01

    Full Text Available The performance of a new design of batch solar water heater has been studied. In this system, the collector and storage were installed in one unit. Unlike the conventional design consisting of small diameter water tubes, it has a single large diameter drum which serves the dual purpose of absorber tube and storage tank. In principle it is a compound parabolic collector. The drum is sized to have a storage capacity of 100 liter to serve a family of four persons. The tests were carried out with a single glass cover and two glass covers. The tests were repeated for several days. Performance analysis of the collector has revealed that it has maximum mean daily efficiency with two glass covers as high as 37.2%. The maximum water temperature in the storage tank of 60°C has been achieved for a clear day operation at an average solar beam radiation level of 680 W/m2 and ambient temperature of 32°C. To judge the operating characteristics and to synchronize utility pattern of the collector, the different parameters such as efficiency, mean plate temperature and mass flow rate has been investigated.

  10. Behavior of a solar collector loop during stagnation

    DEFF Research Database (Denmark)

    Chen, Ziqian; Dragsted, Janne; Furbo, Simon

    2015-01-01

    A mathematical model simulating the emptying behavior of a pressurized solar collector loop with solar collectors with a good emptying behavior is developed and validated with measured data. The calculated results are in good agreement with the measured results. The developed simulation model...... is therefore suitable to determine the behavior of a solar collector loop during stagnation. A volume ratio R, which is the ratio of the volume of the vapour in the upper pipes of the solar collector loop during stagnation and the fluid content of solar collectors, is introduced to determine the mass...... of the collector fluid pushed into the expansion vessel during stagnation, Min. A correlation function for the mass Min and the volume ratio R for solar collector loops is obtained. The function can be used to determine a suitable size of expansion vessels for solar collector loops....

  11. Two-axis movable concentrating solar energy collector

    Science.gov (United States)

    Perkins, G. S.

    1977-01-01

    Proposed solar-tracker collector assembly with boiler in fixed position, allows use of hard line connections, capable of withstanding optimum high temperature fluid flow. System thereby eliminates need for flexible or slip connection previously used with solar collector systems.

  12. Multiple-effect diffusion solar still coupled with a vacuum-tube collector and heat pipe

    KAUST Repository

    Chong, Tze-Ling

    2014-08-01

    The present study develops a multiple-effect diffusion solar still (MEDS) with a bended-plate design in multiple-effect diffusion unit (MDU) to solve the peel-off problem of wick material. The MDU is coupled with a vacuum-tube solar collector to produce a high temperature gradient for high productivity. A heat pipe is used to transfer the solar heat to the MDU. A prototype MEDS-1L was built and tested outdoors. Four performance indexes are proposed for the performance evaluation of MEDS, including daily pure water production per unit area of glass cover, solar absorber, and evaporating surface (Mcov, Msol, Mevp, respectively), and solar distillation efficiency Rcov. The outdoor test results of MEDS-1L show that the solar collector supply temperature Th reaches 100°C at solar radiation 800Wm-2. The highest Mcov is 23.9kgm-2d-1 which is about 29% higher than the basin-type MEDS [11]. The highest value is 25.9kgm-2d-1 for Msol and 2.79kgm-2d-1 for Mevp. The measured Rcov is 1.5-2.44, higher than the basin-type MEDS (1.45-1.88). The Mcov, Msol, Mevp and Rcov of MEDS-1L are all higher than the theoretical calculation of a MEDS with a flat-plate solar collector coupled with a heat pipe (MEDS-FHP) [17].© 2014 Elsevier B.V.

  13. Survey of active solar thermal collectors, industry and markets in Canada : final report

    International Nuclear Information System (INIS)

    2005-08-01

    A survey of the solar thermal industry in Canada was presented. The aim of the survey was to determine the size of the Canadian solar thermal industry and market. Data were used to derive thermal energy output as well as avoided greenhouse gas (GHG) emissions from solar thermal systems. The questionnaire was distributed to 268 representatives. Results revealed annual sales of 24.2, 26.4 and 37.5 MW TH in 2002, 2003, and 2004 respectively, which represented over 50 per cent growth in the operating base during the 3 year survey period. Sales of all collector types grew substantially during the 3 year period, and survey respondents anticipated 20 per cent growth in both 2005 and 2006. Approximately 10 per cent of all sales were exported during 2002-2004. Unglazed liquid collectors constituted the majority of collector types sold in Canada, almost all of which were sold into the residential sector for swimming pool heating. The majority of air collectors were sold into the industrial/commercial and institutional (I/CI) sectors for use in space heating. Sales of liquid glazed and evacuated tube collectors were split between the residential and I/CI sectors. Residential sales were primarily for domestic water heating. In 2004, 23 per cent of sales in the residential sector were for combination domestic hot water and space heating applications, an indication of strong growth. Results of the survey indicated that the solar thermal market in Quebec differed from other regions, with more than double the annual per capita revenue of any other region as a result of greater market penetration of unglazed air collectors. Calculations of the GHG emissions avoided due to active solar thermal systems were made based on historical estimates of solar thermal installations. A model was developed to calculate an operating base by collector type from 1979 to the present. The model showed that many of the systems installed during the 1980s were decommissioned during the 1990s, and that

  14. Survey of active solar thermal collectors, industry and markets in Canada : final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-08-01

    A survey of the solar thermal industry in Canada was presented. The aim of the survey was to determine the size of the Canadian solar thermal industry and market. Data were used to derive thermal energy output as well as avoided greenhouse gas (GHG) emissions from solar thermal systems. The questionnaire was distributed to 268 representatives. Results revealed annual sales of 24.2, 26.4 and 37.5 MW{sub TH} in 2002, 2003, and 2004 respectively, which represented over 50 per cent growth in the operating base during the 3 year survey period. Sales of all collector types grew substantially during the 3 year period, and survey respondents anticipated 20 per cent growth in both 2005 and 2006. Approximately 10 per cent of all sales were exported during 2002-2004. Unglazed liquid collectors constituted the majority of collector types sold in Canada, almost all of which were sold into the residential sector for swimming pool heating. The majority of air collectors were sold into the industrial/commercial and institutional (I/CI) sectors for use in space heating. Sales of liquid glazed and evacuated tube collectors were split between the residential and I/CI sectors. Residential sales were primarily for domestic water heating. In 2004, 23 per cent of sales in the residential sector were for combination domestic hot water and space heating applications, an indication of strong growth. Results of the survey indicated that the solar thermal market in Quebec differed from other regions, with more than double the annual per capita revenue of any other region as a result of greater market penetration of unglazed air collectors. Calculations of the GHG emissions avoided due to active solar thermal systems were made based on historical estimates of solar thermal installations. A model was developed to calculate an operating base by collector type from 1979 to the present. The model showed that many of the systems installed during the 1980s were decommissioned during the 1990s, and

  15. Study and modeling of energy performance of a hybrid photovoltaic/thermal solar collector: Configuration suitable for an indirect solar dryer

    International Nuclear Information System (INIS)

    Slimani, Mohamed El Amine; Amirat, Madjid; Bahria, Sofiane; Kurucz, Ildikó; Aouli, M’heni; Sellami, Rabah

    2016-01-01

    Highlights: • The simulation results are in compliance with the experimental measurements indicated in the previous literature. • The accuracy of the numerical model is due to the presented energy analysis and also to the well-adopted correlations. • A comparative study between two solar photovoltaic/thermal air collectors was carried out. • The thermal efficiency of the analyzed hybrid collector increased by 30.85% compared to the basic configuration. • The air temperature supplied by a double-pass photovoltaic/thermal collector is very suitable for solar drying. - Abstract: In this paper, a configuration of photovoltaic-thermal hybrid solar collector embeddable in an indirect solar dryer system is studied. In the present structure of the solar photovoltaic/thermal air collector, the air goes through a double pass below and above the photovoltaic module. A system of electrical and thermal balance equations is developed and analyzed governing various electric and heat transfer parameters in the solar hybrid air collector. The numerical model planned for this study gives a good precision of results, which are close to the experimental ones (of previous literature), and makes it possible to have a good assessment of energy performance regarding the studied configuration (temperature, electric and thermal powers, electrical and thermal efficiencies, etc.). The numerical results show the energy effectiveness of this hybrid collector configuration and particularly its interesting use in an indirect solar dryer system that provides a more suitable air temperature for drying agricultural products. The values of the electrical, thermal and overall energy efficiencies reaches 10.5%, 70% and 90% respectively, with a mass flow rate of 0.0155 kg/s and weather data sample for the month of June in the Algiers site. The results presented in this study also reveal how important the effect of certain parameters and operating conditions on the performance of the hybrid

  16. A tool for standardized collector performance calculations including PVT

    DEFF Research Database (Denmark)

    Perers, Bengt; Kovacs, Peter; Olsson, Marcus

    2012-01-01

    A tool for standardized calculation of solar collector performance has been developed in cooperation between SP Technical Research Institute of Sweden, DTU Denmark and SERC Dalarna University. The tool is designed to calculate the annual performance of solar collectors at representative locations...... can be tested and modeled as a thermal collector, when the PV electric part is active with an MPP tracker in operation. The thermal collector parameters from this operation mode are used for the PVT calculations....

  17. PERFORMANCE EVALUATION OF SOLAR COLLECTORS USING A SOLAR SIMULATOR

    OpenAIRE

    M. Norhafana; Ahmad Faris Ismail; Z. A. A. Majid

    2015-01-01

    Solar water heating systems is one of the applications of solar energy. One of the components of a solar water heating system is a solar collector that consists of an absorber. The performance of the solar water heating system depends on the absorber in the solar collector. In countries with unsuitable weather conditions, the indoor testing of solar collectors with the use of a solar simulator is preferred. Thus, this study is conducted to use a multilayered absorber in the solar collector of...

  18. Local Reasoning about a Copying Garbage Collector

    DEFF Research Database (Denmark)

    Torp-Smith, Noah; Birkedal, Lars; Reynolds, John C.

    2008-01-01

    We present a programming language, model, and logic appropriate for implementing and reasoning about a memory management system. We state semantically what is meant by correctness of a copying garbage collector, and employ a variant of the novel separation logics to formally specify partial corre...

  19. 31 CFR 203.17 - Collector depositaries.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Collector depositaries. 203.17 Section 203.17 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE, DEPARTMENT OF THE TREASURY FINANCIAL MANAGEMENT SERVICE PAYMENT OF FEDERAL TAXES AND THE TREASURY...

  20. Copyright, Property and the Film Collector

    Science.gov (United States)

    Nevins, Francis M., Jr.

    1975-01-01

    Legal issues surrounding the collecting of movies are analyzed with the conclusion that neither law nor public policy supports a cause for action against the ultimate consumer of film prints and that it is not in a studio's economic interest to bring such actions against collectors. (JT)

  1. Colored solar collectors - Annual report 2006

    Energy Technology Data Exchange (ETDEWEB)

    Schueler, A.; Chambrier, E. De; Roecker, Ch.; Scartezzini, J.-L.

    2007-12-15

    The architectural integration of thermal solar collectors into buildings is often limited by their black color, and the visibility of tubes and corrugations of the absorber sheets. A certain freedom in color choice would be desirable, but the colored appearance should not cause an excessive degradation of the collector efficiency. Multilayered thin film interference filters on the collector glazing can produce a colored reflection, hiding the corrugated metal sheet, while transmitting the non-reflected radiation entirely to the absorber. These interference filters are designed and optimized by numerical simulation, and are manufactured by sol-gel dip-coating or magnetron sputtering. The novel colored glazed solar collectors will be ideally suited for architectural integration into buildings, e.g. as solar active glass facades. Due to the tunability of the refractive index, nanostructured materials such as SiO{sub 2}:TiO{sub 2} composites and porous SiO{sub 2} are very useful for application in multilayer interference stacks. Novel quaternary Mg-F-Si-O films exhibit a surprisingly low refractive index and are therefore promising candidates for highly transparent coatings on solar collector glazing. The nanostructure of these thin films is studied by transmission electron microscopy, while the optical constants are measured precisely by ellipsometry. For a convincing demonstration, sufficiently large samples of high quality are imperatively needed. The fabrication of nanocomposite SiO{sub 2}:TiO{sub 2} films has been demonstrated by sol-gel dip-coating of A4-sized glass panes. The produced coatings exhibit a colored reflection in combination with a high solar transmittance, a homogenous appearance, and are free of visible defects. Film hardening by UV exposure will result in speeding up the sol-gel process and saving energy, thereby reducing costs significantly. The infrastructure for UV-curing has been established. A UV C radiation source can now be attached to the

  2. On the Failure of Upscaling the Single-Collector Efficiency to the Transport of Colloids in an Array of Collectors

    Science.gov (United States)

    Messina, F.; Tosco, T.; Sethi, R.

    2017-12-01

    Colloidal transport and deposition in saturated porous media are phenomena of considerable importance in a large number of natural processes and engineering applications, such as the contaminant and microorganism propagation in aquifer systems, the development of innovative groundwater remediation technologies, air and water filtration, and many others. Therefore, a thorough understanding of particle filtration is essential for predicting the transport and fate of colloids in the subsurface environment. The removal efficiency of a filter is a key aspect for colloid transport in porous media. Several efforts were devoted to derive accurate correlations for the single collector efficiency, one of the key concept in the filtration theory. However, up scaling this parameter to the entire porous medium is still a challenge. The common up-scaling approach assumes the deposition to be independent of the transport history, which means that the collector efficiency is considered uniform along the porous medium. However, previous works showed that this approach is inadequate under unfavorable deposition conditions. This study demonstrates that it is not adequate even in the simplest case of favorable deposition. Computational Fluid Dynamics simulations were run for a simplify porous media geometry, composed of a vertical array of 50 identical spherical collectors. A combination of Lagrangian and Eulerian simulations were performed to analyze the particle transport under a broad range of parameters (i.e., particle size, particle density, water velocity). The results show the limits of the existing models to interpret the experimental data. In fact, the outcome evidenced that when particle deposition is not controlled by Brownian diffusion, non-exponential concentration profiles are retrieved, in contrast with the assumption of uniform efficiency. Moreover, when the deposition mechanisms of sedimentation and interception dominate, the efficiency of the first sphere of the

  3. A numerical investigation of laminar forced convection in a solar collector with non-circular duct

    Directory of Open Access Journals (Sweden)

    Teleszewski Tomasz Janusz

    2017-01-01

    Full Text Available This paper presents a two-dimensional numerical study to investigate laminar flow in a flat plate solar collector with non-circular duct (regular polygonal, elliptical, and Cassini oval shape featuring forced convection with constant axial wall heat flux and constant peripheral wall temperature (H1 condition. Applying the velocity profile obtained for the duct laminar flow, the energy equation was solved exactly for the constant wall heat flux using the Boundary Element Method (BEM. Poiseuille and Nusselt numbers were obtained for flows having a different number of geometrical factors. The results are presented and discussed in the form of tables and graphs. The area goodness factor and volume goodness factor are calculated. The predicted correlations for Poiseuille and Nusselt numbers may be a very useful resource for the design and optimization of solar collectors with non-circular ducts.

  4. Study of a new solar adsorption refrigerator powered by a parabolic trough collector

    International Nuclear Information System (INIS)

    El Fadar, A.; Mimet, A.; Azzabakh, A.; Perez-Garcia, M.; Castaing, J.

    2009-01-01

    This paper presents the study of solar adsorption cooling machine, where the reactor is heated by a parabolic trough collector (PTC) and is coupled with a heat pipe (HP). This reactor contains a porous medium constituted of activated carbon, reacting by adsorption with ammonia. We have developed a model, based on the equilibrium equations of the refrigerant, adsorption isotherms, heat and mass transfer within the adsorbent bed and energy balance in the hybrid system components. From real climatic data, the model computes the performances of the machine. In comparison with other systems powered by flat plate or evacuated tube collectors, the predicted results, have illustrated the ability of the proposed system to achieve a high performance due to high efficiency of PTC, and high flux density of heat pipe

  5. A numerical investigation of laminar forced convection in a solar collector with non-circular duct

    Science.gov (United States)

    Janusz Teleszewski, Tomasz

    2017-11-01

    This paper presents a two-dimensional numerical study to investigate laminar flow in a flat plate solar collector with non-circular duct (regular polygonal, elliptical, and Cassini oval shape) featuring forced convection with constant axial wall heat flux and constant peripheral wall temperature (H1 condition). Applying the velocity profile obtained for the duct laminar flow, the energy equation was solved exactly for the constant wall heat flux using the Boundary Element Method (BEM). Poiseuille and Nusselt numbers were obtained for flows having a different number of geometrical factors. The results are presented and discussed in the form of tables and graphs. The area goodness factor and volume goodness factor are calculated. The predicted correlations for Poiseuille and Nusselt numbers may be a very useful resource for the design and optimization of solar collectors with non-circular ducts.

  6. Performance Investigation and Structure Optimization of a Flat Dual-Function Solar Collector

    Directory of Open Access Journals (Sweden)

    Jinwei Ma

    2015-01-01

    Full Text Available The performance of a dual-function solar collector (DFSC that can work as either water heater or air heater depending on seasonal requirement is investigated via both experimental and numerical approaches in this paper. The numerical results are well consistent with the experimental results. Daily efficiency of the thermosiphon system with DFSC is more than 55% in water heating mode and the instantaneous air heating efficiency of the collector reaches 60%. The effects of inner parameters on the thermal efficiency of the collector are analyzed by numerical simulations of the operation of DFSC in two working modes. It is found that the depths of the two air channels in DFSC have an optimal range suitable for both working modes. The thickness of back insulation should be no less than 0.06 m to prevent heat loss via backboard, and the diameter and number of copper tubes show notable effect on the efficiency of DFSC in water heating mode but slight effect in air heating mode.

  7. Modeling and experimental validation of the solar loop for absorption solar cooling system using double-glazed collectors

    International Nuclear Information System (INIS)

    Marc, Olivier; Praene, Jean-Philippe; Bastide, Alain; Lucas, Franck

    2011-01-01

    Solar cooling applied to buildings is without a doubt an interesting alternative for reducing energy consumption in traditional mechanical steam compression air conditioning systems. The study of these systems should have a closely purely fundamental approach including the development of numerical models in order to predict the overall installation performance. The final objective is to estimate cooling capacity, power consumption, and overall installation performance with relation to outside factors (solar irradiation, outside temperature...). The first stage in this work consists of estimating the primary energy produced by the solar collector field. The estimation of this primary energy is crucial to ensure the evaluation of the cooling capacity and therefore the cooling distribution and thermal comfort in the building. Indeed, the absorption chiller performance is directly related to its heat source. This study presents dynamic models for double glazing solar collectors and compares the results of the simulation with experimental results taken from our test bench (two collectors). In the second part, we present an extensive collector field model (36 collectors) from our solar cooling installation at The University Institute of Technology in St Pierre, Reunion Island as well as our stratified tank storage model. A comparison of the simulation results with real scale solar experimental data taken from our installation enables validation of the double glazing solar collector and stratified tank dynamic models.

  8. Arrangement, manufacturing process and use of solar heat collectors

    Energy Technology Data Exchange (ETDEWEB)

    Scheel, H W

    1978-03-30

    Solar collectors generally have a timber or metal frame where the transparent front cover, usually of glass, is replaceable. In order to prevent great deformation, such a frame must be relatively stable and of heavy construction, which may lead to difficulties in mounting the collector on the roofs or front walls of houses. The present invention proposes a light but nevertheless rigid collector frame, which consists of plastic material and is constructed so that the installation and replacement of collectors can be realized. Further, collectors are proposed which guarantee a minimum of reflection and are so designed that an optimum architectural effect is produced.

  9. Solar collector design with respect to moisture problems

    DEFF Research Database (Denmark)

    Holck, Ole; Svendsen, Svend; Brunold, Stefan

    2003-01-01

    more ventilation openings should be made and what influence the insulation material has. Guidelines for collector designers are proposed. The design guidelines provide some suggestions to be considered during the design of solar collectors.The work was carried out within the framework of the working...... group Materials in Solar Thermal Collectors of the International Energy Agency-Solar Heating and Cooling Programme....... the design of the collector, the location and size of ventilation holes, properties of the insulation materials and dimension of the solar collector box are parameters that have to be taken into account for the optimisation in order to achieve the most favourable microclimate to prevent corrosion...

  10. Integrated Design of Undepressed Collector for Low Power Gyrotron

    Science.gov (United States)

    Kumar, Anil; Goswami, Uttam K.; Poonia, Sunita; Singh, Udaybir; Kumar, Nitin; Alaria, M. K.; Bera, A.; Khatun, Hasina; Sinha, A. K.

    2011-06-01

    A 42 GHz, 200 kW continuous wave (CW) gyrotron, operating at TE03 mode is under development for the electron cyclotron resonance plasma heating of the Indian TOKAMAK system. The gyrotron is made up of an undepressed collector. The undepressed collector is simple to design and cost effective. In this paper, a detailed design study of the undepressed collector for the 42 GHz gyrotron is presented. The EGUN code is used to analyze the spent electron beam trajectory for the maximum spread to reduce the power loading on the collector surface. To achieve wall loading ≤1 kW/cm2, a collector with a length of 800 mm and a radius of 42.5 mm is designed. The design also includes the three magnet systems around the collector for maximum and uniform beam spread. The thermal and the structural analyses are done using the ANSYS code to optimize the collector structure and dimensions with tolerance.

  11. COSTEAU - preheating and cooling by means of underground collectors with water circulation - case study (Perret building at Satigny, Geneva) and generalisation; COSTEAU. Prechauffage et rafraichissement par collecteurs souterrains a eau. Etude de cas (batiment Perret a Satigny, Geneve) et generalisation

    Energy Technology Data Exchange (ETDEWEB)

    Hollmuller, P.; Lachal, B.

    2003-07-01

    Since a couple of years, underground collectors with air circulation have been becoming increasingly popular as a simple means for preheating (at winter time) and cooling (at summer time) of outdoor air ahead of a ventilation system for well insulated buildings. This report considers underground collectors with water circulation used for similar purposes. They are connected to the ventilation system via an air/water heat exchanger. Starting from a case study - one-year detailed in-situ measurements and data analysis from an air-heated office building near Geneva, Switzerland - computerised simulations have been performed as a sensitivity analysis tool as well as to establish recommendations and sizing rules for planners, including cost considerations. In the case study it turned out that the water-circulated underground collector, which is installed right under the basement of this well insulated building, is in thermal contact with the basement. Its main function is to damp the daily temperature oscillation of the inlet ventilation air, bringing the expected thermal comfort improvement in the summer time. However, this underground collector is unable to collect seasonally stored heat from the ground. Hence, in the winter time the main preheating contribution arises from the series-connected heat-recovery unit from the exit air. Numerical simulations show that optimal sizing of underground collectors is essential, and that both the underground collector and the well insulated building as a physical system with thermal inertia have to be simultaneously considered in the optimization process. Optimization also has to include parasitic energy (electricity) needed by fans and pumps. As outdoor air inlet can never be flooded in the case of underground collectors with water circulation the sanitary risk encountered with air-circulated underground collectors does not exist for them. Initial investment cost for water-circulated underground collectors is higher than for a

  12. Preheating of tap water with solar collectors

    Energy Technology Data Exchange (ETDEWEB)

    Granum, H; Raaen, H

    1992-05-05

    In 1991 SINTEF Architecture and Building Technology won the second prize in 'The Nordic Competition for Low Energy Buildings' with a project proposal named 'LOWe'. The paper gives a description of the energy-saving features of this project, particularly the use of a solar collector for preheating of tap water. Compared with the economic profitability of other saving efforts in the project, such as good thermal insulation and efficient heat recovering system, the system for solar preheating of tap water does not seem very attractive for the time being. Loose estimates indicate a cost of close of NOK 1.00 per kWh for the produced energy in the solar collector, while the present price for electricity in Norway is about NOK 0.50 per kWh. Compared with a heat pump solution however the energy cost is not unreasonable.

  13. Assessment of musculoskeletal load in refuse collectors

    Directory of Open Access Journals (Sweden)

    Zbigniew W. Jóźwiak

    2013-08-01

    Full Text Available Background: The aim of this work was to assess the load on the musculoskeletal system and its effects in the collectors of solid refuse. The rationale behind this study was to formulate proposals how to reduce excessive musculoskeletal load in this group of workers. Material and Methods: The study group comprised 15 refuse collectors aged 25 to 50 years. Data about the workplace characteristics and subjective complaints of workers were collected by the free interview and questionnaire. During the survey the photorecording of the workpostures, the distance and velocity by GPS recorders, measurements of forces necessary to move containers, energy expenditure (lung ventilation method, workload estimation using the Firstbeat system and REBA method and stadiometry were done. Results: The distance walked daily by the collectors operating in terms of 2 to 3 in urban areas was about 15 km, and in rural areas about 18 km. The most frequent musculoskeletal complaints concerned the feet (60% subjects, knees, wrists and shoulders (over 40% subjects. After work-shift all examined workers had vertebral column shorter by 10 to 14 mm (11.4 mm mean. Conclusions: The results of our study show that the refuse collectors are subjected to a very high physical load because of the work organization and the way it is performed. To avoid adverse health effects and overload it is necessary to undertake ergonomic interventions, involving training of workers to improve the way of their job performance, active and passive leisure, technical control of the equipment and refuse containers, as well as the renegotiation of contracts with clients, especially those concerning non-standard containers. Med Pr 2013;64(4:507–519

  14. Theoretical study of fluidized solar collector performance

    Energy Technology Data Exchange (ETDEWEB)

    Adulla, S. H; Kassem, M A; El-Refaie, M. F. [Cairo University, Giza (Egypt)

    2000-07-01

    This work presents a proposed novel design aiming to increasing the absorber-to-fluid heat transfer coefficient. This is accomplished by introducing small solid particles inside the collector tubes. When the collector liquid flows, it causes the particles to be fluidized and spread in the tubes. The particles material, size and total number should be turned together with the fluid mass flow rate to keep the bed, or particle dispersion, length within the physical length of collector tubes. Thus, the particles would be confined in the collector only; and not carried over to other parts of the circulation loop. While moving, the particles erode the thermal boundary layer formed on the tube inner surface, hence increasing the heat transfer coefficient. [Spanish] Este articulo presenta un diseno novedoso destinado a aumentar el coeficiente de trasferencia de calor de absorbedor a fluido. Esto se lleva a cabo mediante la introduccion de particulas solidas dentro de los tubos del colector. Cuando fluye el liquido del colector origina que las particulas se fluidicen y se diseminen en los tubos. El material de las particulas, tamano y numero total debera de ser puesto en movimiento junto con el regimen de flujo de masa de fluido para mantener el lecho o la dispersion de particulas por largo tiempo dentro de la longitud fisica de los tubos de colector. De esta manera las particulas seran confinadas solamente en el colector y no seran arrastradas a otras partes del anillo de circulacion. Al moverse, las particulas erosionan la capa de frontera termica formada en la superficie interior del tubo, aumentando por tanto el coeficiente de transmision de calor.

  15. Experimental evaluation of a direct air-cooled lithium bromide-water absorption prototype for solar air conditioning

    International Nuclear Information System (INIS)

    Gonzalez-Gil, A.; Izquierdo, M.; Marcos, J.D.; Palacios, E.

    2011-01-01

    A new direct air-cooled single-effect LiBr-H 2 O absorption prototype is described and proposed for use in solar cooling. As distinguishing aspects, it presents: an adiabatic absorber using flat-fan sheets; an air-cooling system that directly refrigerates both the condenser and the absorber and; the possibility of being operated also as a double-effect unit. A solar facility comprising a 48 m 2 field of flat-plate collectors was used to test the single-effect operation mode of the prototype. Results from an experimental campaign carried out in Madrid during summer 2010 are shown and operation parameters corresponding to two typical summer days are detailed. The prototype worked efficiently, with COP values around 0.6. Cooling power varied from 2 kW to 3.8 kW, which represented about 85% of the prototype's nominal capacity. Chilled water temperatures mostly ranged between 14 o C and 16 o C, although the lowest measured value was of 12.8 o C. Condensation and absorption temperatures were under 50 o C and 46 o C, respectively, even with outdoor temperatures of 40 o C. Driving water temperature ranged between 85 o C and 110 o C. As a mean, the system was able to meet 65% of the cooling demand corresponding to a room of 40 m 2 . No signs of crystallization were observed during about a hundred hours of operation. - Highlights: → A novel direct air-cooled single-effect absorption prototype is described. → Feasibility of air-cooled technology for LiBr-H 2 O absorption cooling is proved. → An adiabatic absorber using flat-fan sheets avoids crystallization of the solution. → A field of flat-plate collectors powers the chiller at temperatures from 85 to 110 o C. → The prototype works with thermal COP about 0.6.

  16. Simulation of a solar collector array consisting of two types of solar collectors, with and without convection barrier

    DEFF Research Database (Denmark)

    Bava, Federico; Furbo, Simon; Perers, Bengt

    2015-01-01

    The installed area of solar collectors in solar heating fields is rapidly increasing in Denmark. In this scenario even relatively small performance improvements may lead to a large increase in the overall energy production. Both collectors with and without polymer foil, functioning as convection...... barrier, can be found on the Danish market. Depending on the temperature level at which the two types of collectors operate, one can perform better than the other. This project aimed to study the behavior of a 14 solar collector row made of these two different kinds of collectors, in order to optimize...... the composition of the row. Actual solar collectors available on the Danish market (models HT-SA and HT-A 35-10 manufactured by ARCON Solar A/S) were used for this analysis. To perform the study, a simulation model in TRNSYS was developed based on the Danish solar collector field in Braedstrup. A parametric...

  17. Improved Collectors for High Power Gyrotrons

    International Nuclear Information System (INIS)

    Ives, R. Lawrence; Singh, Amarjit; Read, Michael; Borchard, Philipp; Neilson, Jeff

    2009-01-01

    High power gyrotrons are used for electron cyclotron heating, current drive and parasitic mode suppression in tokamaks for fusion energy research. These devices are crucial for successful operation of many research programs around the world, including the ITER program currently being constructed in France. Recent gyrotron failures resulted from cyclic fatigue of the copper material used to fabricated the collectors. The techniques used to collect the spent beam power is common in many gyrotrons produced around the world. There is serious concern that these tubes may also be at risk from cyclic fatigue. This program addresses the cause of the collector failure. The Phase I program successfully demonstrated feasibility of a mode of operation that eliminates the cyclic operation that caused the failure. It also demonstrated that new material can provide increased lifetime under cyclic operation that could increase the lifetime by more than on order of magnitude. The Phase II program will complete that research and develop a collector that eliminates the fatigue failures. Such a design would find application around the world.

  18. Air

    International Nuclear Information System (INIS)

    Gugele, B.; Scheider, J.; Spangl, W.

    2001-01-01

    In recent years several regulations and standards for air quality and limits for air pollution were issued or are in preparation by the European Union, which have severe influence on the environmental monitoring and legislation in Austria. This chapter of the environmental control report of Austria gives an overview about the legal situation of air pollution control in the European Union and in specific the legal situation in Austria. It gives a comprehensive inventory of air pollution measurements for the whole area of Austria of total suspended particulates, ozone, volatile organic compounds, nitrogen oxides, sulfur dioxide, carbon monoxide, heavy metals, benzene, dioxin, polycyclic aromatic hydrocarbons and eutrophication. For each of these pollutants the measured emission values throughout Austria are given in tables and geographical charts, the environmental impact is discussed, statistical data and time series of the emission sources are given and legal regulations and measures for an effective environmental pollution control are discussed. In particular the impact of fossil-fuel power plants on the air pollution is analyzed. (a.n.)

  19. FY 1977 Annual report on Sunshine Project results. Research and development of solar energy systems for air conditioning and hot water supply (Research and development of solar systems for condominiums); 1977 nendo taiyo reidanbo oyobi kyuto system no kenkyu kaihatsu seika hokokusho. Shugo jutakuyo system no kenkyu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1978-06-01

    This project is aimed at technological development of economical solar energy systems for air conditioning and hot water supply for condominiums. The major items for the FY 1977 programs include (1) designs and fabrication of equipment for a test building, (2) development of the equipment materials, and (3) system analysis. The jobs for item (1) include management of the designs and construction, placing an order for the building, and fabrication of an air conditioner expander and heat pump; those for item (2) include simplification of a condensing type and plate type heat collector structures, weather-resistance of the plate type heat collector structure, and materials for selective absorbing membranes and reflectors; and those for item (3) include estimation of heat loads in a model building, first to third floors as the test building, and fourth to 14th floors as the conventional box-shaped building. The heat collector installation area is investigated for a multistory building, for which solar radiation intensity at the heat-receiving plane and the like are taken into account. It is found that the solar system can be installed, when an area of 50m{sup 2} can be allocated to the system in each story. There is a limit to story number for the solar system to economically work for air conditioning and hot water supply. Sufficient insulation of the system and reduction in pipe length by zoning are the necessary measures against heat losses. (NEDO)

  20. Development of measure methods of radon in indoor air

    International Nuclear Information System (INIS)

    Yaginuma, L.T.; Pela, C.A.; Navas, E.A.; Ghilardi, A.J.P.

    1992-01-01

    The development of some conventional measuring methods, aiming obtain an estimation of radon concentration in air, mainly in indoor air is described, including the charcoal absorption collector, Lucas cell and thermoluminescent dosemeters. (C.G.C)

  1. Evaluation of Test Method for Solar Collector Efficiency

    DEFF Research Database (Denmark)

    Fan, Jianhua; Shah, Louise Jivan; Furbo, Simon

    The test method of the standard EN12975-2 (European Committee for Standardization, 2004) is used by European test laboratories to determine the efficiency of solar collectors. In the test methods the mean solar collector fluid temperature in the solar collector, Tm is determined by the approximat...... and the sky temperature. Based on the investigations, recommendations for change of the test methods and test conditions are considered. The investigations are carried out within the NEGST (New Generation of Solar Thermal Systems) project financed by EU.......The test method of the standard EN12975-2 (European Committee for Standardization, 2004) is used by European test laboratories to determine the efficiency of solar collectors. In the test methods the mean solar collector fluid temperature in the solar collector, Tm is determined by the approximated...... equation where Tin is the inlet temperature to the collector and Tout is the outlet temperature from the collector. The specific heat of the solar collector fluid is in the test method as an approximation determined as a constant equal to the specific heat of the solar collector fluid at the temperature Tm...

  2. Thermal performance of a transpired solar collector updraft tower

    International Nuclear Information System (INIS)

    Eryener, Dogan; Hollick, John; Kuscu, Hilmi

    2017-01-01

    Highlights: • Transpired solar collector updraft tower has been studied experimentally. • Transpired solar collector updraft tower efficiency ranges from 60 to 80%. • A comparison has been made with other SUT prototypes. • Three times higher efficiency compared to the glazed collectors of conventional solar towers. - Abstract: A novel solar updraft tower prototype, which consists of transpired solar collector, is studied, its function principle is described and its experimental thermal performance is presented for the first time. A test unit of transpired solar collector updraft tower was installed at the campus of Trakya University Engineering Faculty in Edirne-Turkey in 2014. Solar radiation, ambient temperature, collector cavity temperatures, and chimney velocities were monitored during summer and winter period. The results showed that transpired solar collector efficiency ranges from 60% to 80%. The maximum temperature rise in the collector area is found to be 16–18 °C on the typical sunny day. Compared to conventional solar tower glazed collectors, three times higher efficiency is obtained. With increased thermal efficiency, large solar collector areas for solar towers can be reduced in half or less.

  3. Performance analysis of a hybrid photovoltaic thermal solar air heater

    International Nuclear Information System (INIS)

    Othman, Mohd Yusof; Yatim, Baharudin; Abu Bakar, Mohd Nazari; Sopian, Kamaruzzaman

    2006-01-01

    A photovoltaic (PV/T) air heater is a collector that combines thermal and photovoltaic systems in one single hybrid generating unit. It generators both thermal and electrical energies simultaneously. A new design of a double-pass photovoltaic-thermal solar air collector with CPC and fins was successfully developed and fabricated at Universiti Kebangsaam Malaysia. This collector tested under actual environmental conditions to study its performance over a range of operating conditions. The test set-up, instrumentation and measurement are described further. It was found that the performance of the collector was in agreement with the theoretical prediction. Results of the outdoors test are presented and discussed(Author)

  4. The impact of internal longitudinal fins in parabolic trough collectors operating with gases

    International Nuclear Information System (INIS)

    Bellos, Evangelos; Tzivanidis, Christos; Daniil, Ilias; Antonopoulos, Kimon A.

    2017-01-01

    Highlights: • In this study, the impact of internal fins in PTC operating with gases is presented. • Air, helium and CO_2 are tested in smooth absorber and with fins of 5–10 mm and 15 mm. • Greater fin length leads to higher thermal efficiency and 10 mm is the optimum length exergetically. • Helium is the best working fluid exergetically, with CO_2 and air to follow. • Up to 290 °C, helium performs better energetically, while CO_2 in higher temperatures. - Abstract: In this study, the use of internal fins in parabolic trough collectors operating with gas working fluids is examined. Air, helium and carbon dioxide are the investigated working fluids, while Eurotrough ET-150 is the examined solar collector. The design and the simulation of this solar collector are performed with the commercial software Solidworks Flow Simulation. The internal fins lead to higher thermal efficiency but also to higher pressure losses; something very important for the solar fields of Concentrated Power Plants. Thus, the collector is examined energetically and exergetically in order to take into account the increase in the useful output with the simultaneous greater need of pumping power. Various fin lengths are examined and finally the fin of 10 mm was proved to be the most appropriate exergetically. In working fluid comparison, helium is the most efficient working fluid exergetically for all the examined cases. In the thermal efficiency comparison, helium performs better up to 290 °C, while carbon dioxide is the best choice in higher temperature levels. Moreover, the optimum mass flow rate for the helium was proved to be 0.03 kg/s and for the other working fluids the value of 0.015 kg/s seems to lead to the most satisfying results.

  5. FY 1977 Annual report on Sunshine Project results. Research and development of solar energy systems for air conditioning and hot water supply (Research and development of glass-based materials); 1977 nendo taiyo reidanbo oyobi kyuto system no kenkyu kaihatsu seika hokokusho. Glass kei zairyo no kenkyu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1978-05-01

    This project is aimed at development of the following collector techniques for various types of solar energy systems for air conditioning and hot water supply: (1) selective transmission glass, (2) reflection-preventive glass, (3) glass-based selective absorption film, and (4) high-performance collector. For the item (1), the STG coated with a reflection-preventive film of In{sub 2}O{sub 3} and that with MgF{sub 2} attain the target performance, and high-speed sputtering is investigated for development of the mass production techniques and promising results are produced. For the item (2), formation of a uniform reflection-preventive film on the glass's front surface and improvement of the reproducibility are investigated, and promising results are produced. For the item (3), a selective absorption plane having a solar radiation absorptivity of 0.90 or more and infrared emissivity of 0.30 or less is produced by baking a SnO{sub 2} film on a soft steel plate undercoated with a black glaze as the glass-based film. For the item (4), a total of 4 types of collectors are fabricated on a trial basis and tested for their heat-collecting performance; a honeycomb type with the selective absorption film, modified laminated type with changed pipe arrangement, one using a large-size reflection-preventive glass, and another one with changed method for supporting the heat-collecting plate. Attainable performance level of the flat plate type collector for commercial purposes is estimated, and the specifications of the commercial collector as the research target are determined. (NEDO)

  6. Energy and exergy analysis of photovoltaic-thermal collector with and without glass cover

    International Nuclear Information System (INIS)

    Chow, T.T.; Pei, G.; Fong, K.F.; Lin, Z.; Chan, A.L.S.; Ji, J.

    2009-01-01

    In photovoltaic-thermal (PV/T) technology, the use of glass cover on the flat-plate hybrid solar collector is favorable to the photothermic process but not to the photovoltaic process. Because of the difference in the usefulness of electricity and thermal energy, there is often no straight forward answer on whether a glazed or unglazed collector system is more suitable for a specific application. This glazing issue was tackled in this paper from the viewpoint of thermodynamics. Based on experimental data and validated numerical models, a study of the appropriateness of glass cover on a thermosyphon-based water-heating PV/T system was carried out. The influences of six selected operating parameters were evaluated. From the first law point of view, a glazed PV/T system is found always suitable if we are to maximize the quantity of either the thermal or the overall energy output. From the exergy analysis point of view however, the increase of PV cell efficiency, packing factor, water mass to collector area ratio, and wind velocity are found favorable to go for an unglazed system, whereas the increase of on-site solar radiation and ambient temperature are favorable for a glazed system

  7. Performance enhancement studies in a thermosyphon flat plate solar water heater with CuO nanofluid

    Directory of Open Access Journals (Sweden)

    Dasaien Anin Vincely

    2017-01-01

    Full Text Available Experiments were conducted on a thermosyphon type flat plate collector, inclined at 45°, for water heating application. Water and water based nanofluids were used as absorber fluid to gain heat from solar rays incident on the flat plate col-lector. Nanofluids were prepared by adding CuO nanoparticles of 40-50 nm size to the base fluid at 0.1, 0.2, 0.3, and 0.5 wt% (ζ. The hot absorber fluid was made to circulate in the shell side of a heat exchanger, placed at the top of the flat plate collector, where utility water was circulated inside a helically coiled Cu tube. Temperatures at strategic locations in the flat plate collector, working fluid, utility water inlet and outlet were measured. The nanofluid increases the collector efficiency with increasing ζ. A highest efficiency enhancement of 5.7% was observed for the nanofluid with ζ = 0.2 having a mass flow rate of 0.0033 kg/s. The 3-D, steady-state, conjugate heat transfer CFD analyses were carried out using the ANSYS FLUENT 15.0 software. Theoretically estimated buoyancy induced fluid flow rates were close with the CFD predictions and thus validates the computational methodology.

  8. Simulation of HPIB propagation in biased charge collector

    International Nuclear Information System (INIS)

    Li Hongyu; Qiu Aici

    2004-01-01

    A 2.5D PIC simulation using KARAT code for inner charge propagation within biased charge collector for measuring HPIB is presented. The simulation results indicate that the charges were neutralized but the current non-neutralized in the biased charge collector. The influence of ions collected vs biased voltage of the collector was also simulated. -800 V biased voltage can meet the measurement of 500 keV HPIB, and this is consistent with the experimental results

  9. The flotation and adsorption of mixed collectors on oxide and silicate minerals.

    Science.gov (United States)

    Xu, Longhua; Tian, Jia; Wu, Houqin; Lu, Zhongyuan; Sun, Wei; Hu, Yuehua

    2017-12-01

    The analysis of flotation and adsorption of mixed collectors on oxide and silicate minerals is of great importance for both industrial applications and theoretical research. Over the past years, significant progress has been achieved in understanding the adsorption of single collectors in micelles as well as at interfaces. By contrast, the self-assembly of mixed collectors at liquid/air and solid/liquid interfaces remains a developing area as a result of the complexity of the mixed systems involved and the limited availability of suitable analytical techniques. In this work, we systematically review the processes involved in the adsorption of mixed collectors onto micelles and at interface by examining four specific points, namely, theoretical background, factors that affect adsorption, analytical techniques, and self-assembly of mixed surfactants at the mineral/liquid interface. In the first part, the theoretical background of collector mixtures is introduced, together with several core solution theories, which are classified according to their application in the analysis of physicochemical properties of mixed collector systems. In the second part, we discuss the factors that can influence adsorption, including factors related to the structure of collectors and environmental conditions. We summarize their influence on the adsorption of mixed systems, with the objective to provide guidance on the progress achieved in this field to date. Advances in measurement techniques can greatly promote our understanding of adsorption processes. In the third part, therefore, modern techniques such as optical reflectometry, neutron scattering, neutron reflectometry, thermogravimetric analysis, fluorescence spectroscopy, ultrafiltration, atomic force microscopy, analytical ultracentrifugation, X-ray photoelectron spectroscopy, Vibrational Sum Frequency Generation Spectroscopy and molecular dynamics simulations are introduced in virtue of their application. Finally, focusing on

  10. Plate tectonics

    Digital Repository Service at National Institute of Oceanography (India)

    Chaubey, A.K.

    's continental drift theory was later disproved, it was one of the first times that the idea of crustal movement had been introduced to the scientific community; and it has laid the groundwork for the development of modern plate tectonics. In the early... of the structure of the atom was to physical sciences and the theory of evolution was to the life sciences. Tectonics is the study of the forces within the Earth that give rise to continents, ocean basins, mountain ranges, earthquake belts and other large-scale...

  11. A comparison of two cloudwater/fogwater collectors: The rotating arm collector and the caltech active strand cloudwater collector

    Science.gov (United States)

    Collett, Jeffrey L.; Daube, Bruce C.; Munger, J. William; Hoffmann, Michael R.

    A side-by-side comparison of the Rotating Arm Collector (RAC) and the Caltech Active Strand Cloudwater Collector (CASCC) was conducted at an elevated coastal site near the eastern end of the Santa Barbara Channel in southern California. The CASCC was observed to collect cloudwater at rates of up to 8.5 ml min -1. The ratio of cloudwater collection rates was found to be close to the theoretical prediction of 4.2:1 (CASCC:RAC) over a wide range of liquid water contents (LWC). At low LWC, however, this ratio climbed rapidly, possibly reflecting a predominance of small droplets under these conditions, coupled with a greater collection efficiency of small droplets by the CASCC. Cloudwater samples collected by the RAC had significantly higher concentrations of Na +, Ca 2+, Mg 2+ and Cl - than those collected by the CASCC. These higher concentrations may be due to differences in the chemical composition of large vs small droplets. No significant differences were observed in concentrations of NO 3-, SO 42- or NH 4+ in samples collected by the two instruments.

  12. Create Your Plate

    Medline Plus

    Full Text Available ... Plate Share Create Your Plate ! Share: Seven Simple Steps to Create Your Plate It's simple and effective ... foods within each food category. Try these seven steps to get started: Using your dinner plate, put ...

  13. Adaptive control of solar energy collector systems

    CERN Document Server

    Lemos, João M; Igreja, José M

    2014-01-01

    This book describes methods for adaptive control of distributed-collector solar fields: plants that collect solar energy and deliver it in thermal form. Controller design methods are presented that can overcome difficulties found in these type of plants:they are distributed-parameter systems, i.e., systems with dynamics that depend on space as well as time;their dynamics is nonlinear, with a bilinear structure;there is a significant level of uncertainty in plant knowledge.Adaptive methods form the focus of the text because of the degree of uncertainty in the knowledge of plant dynamics. Parts

  14. Combined solar collector and storage systems

    International Nuclear Information System (INIS)

    Norton, B.; Smyth, M.; Eames, P.; Lo, S.N.G.

    2000-01-01

    The article discusses reasons why fossil-fuelled water heating systems are included in new houses but solar systems are not. The technology and market potential for evacuated tube systems and integral collector storage systems (ICSS) are explained. The challenge for the designers of ICSSWH has been how to reduce heat loss without compromising solar energy collection. A new concept for enhanced energy storage is described in detail and input/output data are given for two versions of ICSSWH units. A table compares the costs of ICSSWH in houses compared with other (i.e. fossil fuel) water heating systems

  15. Performance analysis of a minichannel-based solar collector using different nanofluids

    International Nuclear Information System (INIS)

    Mahian, Omid; Kianifar, Ali; Sahin, Ahmet Z.; Wongwises, Somchai

    2014-01-01

    Highlights: • Performance of a minichannel-based solar collector has been studied using four different nanofluids. • First and second law thermodynamic analyses are conducted by considering constant mass flow rate of nanofluid. • Al 2 O 3 /water nanofluids show the highest heat transfer coefficient in the tubes. • The highest outlet temperature is provided by Cu/water nanofluids. • Cu/water nanofluid produces the lowest entropy generation among the nanofluids. - Abstract: In this paper, an analytical analysis has been performed to evaluate the performance of a minichannel-based solar collector using four different nanofluids including Cu/water, Al 2 O 3 /water, TiO 2 /water, and SiO 2 /water. The analysis of first and second laws is conducted for turbulent flow by considering the constant mass flow rate of nanofluid. The results are presented for volume fractions up to 4% and nanoparticle size of 25 nm where the inner diameter of the risers of flat plate collector is assumed to be 2 mm. Analysis of the first law of thermodynamics reveals that Al 2 O 3 /water nanofluids show the highest heat transfer coefficient in the tubes while the lowest value belongs to SiO 2 /water nanofluids. The highest outlet temperature is provided by Cu/water nanofluids, and after that TiO 2 /water, Al 2 O 3 /water, and SiO 2 /water nanofluids are in ranks of second to fourth. The results of second law analysis elucidate that Cu/water nanofluid produces the lowest entropy generation among the nanofluids. It is found that although the effective thermal conductivity of TiO 2 /water nanofluids is less than Al 2 O 3 /water nanofluids, but the entropy generation of TiO 2 /water is lower than Al 2 O 3 /water. Finally, some recommendations are given for future studies on the applications of nanofluids in solar collectors

  16. Improvement of black nickel coatings. [product development for use in solar collectors

    Science.gov (United States)

    Peterson, R. E.; Lin, J. H.

    1976-01-01

    Selectively absorbing black nickel coatings are among the most optically efficient low cost coatings for use on flat plate solar collectors. However, a current Ni-Zn-S-O coating in use is quite susceptible to a humid environment, degrading badly in less than ten days at 38 C (100 F) at 95 percent relative humidity. Therefore, a black nickel formula was developed which can withstand such exposures with no loss of optical efficiency, solar absorption of 0.92 and an infrared emittance (at 100 C) of 1.00 were still present after 14 days of humidity exposure. This compares to a solar absorptance of only 0.72 for the previous formula after a similar time period. The electroplating bath and conditions were changed to obtain the more stable coating configuration. The effect of bath composition, temperature, pH, and plating current density and time on the coating composition, spectral optical properties and durability were investigated systematically.

  17. A Cost Effective Desalination Plant Using a Solar Chimney with Recycled Aluminum Can Collector

    Directory of Open Access Journals (Sweden)

    Singuru Rajesh

    2016-01-01

    Full Text Available The main objective of the work was to use solar energy for desalination of water. A solar chimney desalination system, which includes the solar chimney, solar collector, evaporation system, and passive condenser, was designed and built. The air enters into collector and gets heated and released at the bottom of chimney. Due to draught effect dry air goes upward. The air is humidified by spraying salt water into the hot air stream using a mistifier at the middle of chimney. Then, the partial vapours contained in the air are condensed to give desalinated water. The performance of the integrated system including power and potable water production was estimated and the results were discussed. With a 3.4 m height setup, experimental test rig was capable of evaporating 3.77 L water daily condensing 2.3 L water. It is compact in nature as it is easy to assemble and dissemble. It can be used for purifying rain water in summer under rain water harvesting. Because of using country wood, recycled Al cans, and GI sheet in fabrication, it is lower in cost.

  18. Dimensioning, construction and commissioning of a coffee beans drying system with use of solar collectors

    International Nuclear Information System (INIS)

    Mora Vindas, Allan Gerardo

    2014-01-01

    A system of low-cost solar drying of coffee beans is dimensioned, built and commissioned by using solar collectors based on recycled aluminum cans. The information is collected from literature about the drying of coffee, types of drying and the various types of solar dryers.The coffee beans drying system is conceptualized and sized based on a solar collector constructed of aluminum cans as solar radiation absorbing material. The grain drying system is then built in coffee benefit CoopeTarrazu to all provided by the company and help materials and labor facilities. A guide to implementation of solar drying technology with general information is tailored to implement, select, build and maintain a solar grain dryer in Central America. The launch of the drying system was made by checking the proper functioning of the system and measurement instruments variables selected to calculate the efficiency of the system. The drying system is tested with a load of 45 kg of coffee bean, using a flow of air through natural convection to operate the system with the exclusive use of renewable energy. The grain is drying from a humidity of 50% (b.n), up to a humidity between 11% and 13% (b.n), which is the range generally used for the safe storage of grain. Facts of solar radiation, temperature, air velocity, relative humidity and grain humidity were taken to determine the behavior of the sized system. The maximum thermal efficiency achieved by the solar collector is determined constructed of 18%, with an air flow of 0.013 kg/s and a solar radiation 1138 W/m 2 . The average drying efficiency during experimentation was 17.8%, which is among the range of efficiencies for the type of drying equipment. Best thermal efficiencies were obtained from the solar collector built that the commercial solar collector compared. Controlling the flow of air into the equipment is recommended in order to improve the thermal efficiency and drying equipment, using blowers, fans or induced draft chimney

  19. DT results of TFTR's alpha collector

    International Nuclear Information System (INIS)

    Herrmann, H.W.; Zweben, S.J.; Darrow, D.S.; Timberlake, J.R.; Macaulay-Newcombe, R.G.

    1996-01-01

    An escaping alpha collector probe has been developed for TFTR's DT phase to complement the results of the lost alpha scintillator detectors which have been operating on TFTR since 1988. Measurements of the energy distribution of escaping alphas have been made by measuring the range of alphas implanted into nickel foils located within the alpha collector. Exposed samples have been analyzed for 4 DT plasma discharges at plasma currents of 1.0 and 1.8 MA. The results at 1.0 MA are in good agreement with predictions for first orbit alpha loss at 3.5 MeV. The 1.8 MA results, however, indicate a large anomalous loss of partially thermalized alphas at an energy ∼30% below the birth energy and at a total fluence nearly an order of magnitude above expected first orbit loss. This anomalous loss is not observed with the lost alpha scintillator detectors in DT plasmas but does resemble the anomalous delayed loss seen in DD plasmas. Several potential explanations for this loss process are examined. None of the candidate explanations proposed thus far are fully consistent with the anomalous loss observations

  20. Protecting solar collector systems from corrosion

    Energy Technology Data Exchange (ETDEWEB)

    1978-01-01

    The main cause of the reduced life of a solar heating system is corrosion of the exterior parts and the internal components. This report outlines ways of reducing the cost of solar heating by reducing the corrosion in solar heating systems, and hence increasing the system's service life. Mechanisms for corrosion are discussed: these include galvanic corrosion and crevice corrosion. Means of minimizing corrosion at the design stage are then described. Such methods, when designing the solar collector, involve ensuring proper drainage of exterior water; eliminating situations where moisture, dirt and pollutants may collect; preventing condensation inside the collector; using proper gaskets and sealants at appropriate places; and selecting optimum materials and coatings. Interior corrosion can be minimized at the design stage by choosing a good heat transfer fluid and corrosion inhibitor, in the case of systems where liquids are used; ensuring a low enough flow rate to avoid erosion; designing the system to avoid crevices; and avoiding situations where galvanic corrosion could occur. Other procedures are given for minimizing corrosion in the construction and operation of solar heating systems. 7 figs., 7 tabs.

  1. Device Performance Improvement of Double-Pass Wire Mesh Packed Solar Air Heaters under Recycling Operation Conditions

    Directory of Open Access Journals (Sweden)

    Chii-Dong Ho

    2016-01-01

    Full Text Available The improvement of device performance of a recycling solar air heater featuring a wire mesh packing was investigated experimentally and theoretically. The application of the wire mesh packing and recycle-effect concept to the present study were proposed aiming to strengthen the convective heat-transfer coefficient due to increased turbulence. Comparisons were made among different designs, including the single-pass, flat-plate double-pass and recycling double-pass wire mesh packed operations. The collector efficiency of the recycling double-pass wire mesh packed solar air heater was much higher than that of the other configurations for various recycle ratios and mass flow rates scenarios. The power consumption increment due to implementing wire mesh in solar air heaters was also discussed considering the economic feasibility. A fairly good agreement between theoretical predictions and experimental measurements was achieved with an analyzed error of 1.07%–9.32%.

  2. Physically absorbable reagents-collectors in elementary flotation

    Energy Technology Data Exchange (ETDEWEB)

    S.A. Kondrat' ev; I.G. Bochkarev [Russian Academy of Sciences, Novosibirsk (Russian Federation). Institute of Mining

    2007-09-15

    Based on the reviewed researches held at the Institute of Mining, Siberian Branch, Russian Academy of Sciences, the effect of physically absorbable reagents-collectors on formation of a flotation complex and its stability in turbulent pulp flows in flotation machines of basic types is considered. The basic requirements for physically absorbable reagents-collectors at different flotation stages are established.

  3. Preliminary design package for solar collector and solar pump

    Science.gov (United States)

    1978-01-01

    A solar-operated pump using an existing solar collector, for use on solar heating and cooling and hot water systems is described. Preliminary design criteria of the collector and solar-powered pump is given including: design drawings, verification plans, and hazard analysis.

  4. Direct-heating solar-collector dump valve

    Science.gov (United States)

    Howikman, T. C.

    1977-01-01

    Five-port ganged valve isolates collector from primary load system pressure and drains collectors, allowing use of direct heating with all its advantages. Valve is opened and closed by same switch that controls pump or by temperature sensor set at O C, while providing direct dump option.

  5. Diagnostics of defeats of venous collectors of brain

    International Nuclear Information System (INIS)

    Timofeeva, T.V.; Polunina, I.S.; Shcherbakova, E.Ya.; Kuldakova, S.V.

    1997-01-01

    Comparative data of transcranial ultrasonic dopplerography (170 patients) and radionuclidous antroscintigraphy (124), received during diagnostics of defects of venous collectors of brain are analyzed. Five variants of defeats of venous collectors (cross, sigmoid, internal of jugular of jugular vein), but also unpaired sine (direct, confluent) are described. Received results permit to reveal interrelation of infringements of venous outflow and increase of intracranial pressure

  6. Characteristic on photovoltaic/thermal hybrid collector. Evaluation of excergetic theory; Taiyoko netsu hybrid collector no tokusei. Exergy ni yoru hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Iwawaki, H; Morita, Y; Fujisawa, T; Tani, T [Science University of Tokyo, Tokyo (Japan)

    1997-11-25

    Described herein are characteristics of photovoltaic (PV)/thermal hybrid collectors (PV/Ts), in which a PV module is combined with a plate-shape solar heat collector to simultaneously produce electric power and heat. Their efficiency is assessed by exergy. The test results indicate that the PV/T system gives a 1.07 times higher exergy than the PV system, 86.3 versus 80.7kWh. In terms of energy, the optimum values (OVs) are 5, 44 and 37% lower than the measuring values (MVs) for electrical energy, thermal energy and total exergy. In terms of exergy, on the other hand, OV is 5% lower than MV for electrical energy, but 893 times higher for thermal energy and 1.26 times higher for total exergy. As a result, the exergy level is 26% higher than that of a system which generates power as the main product and heat as the auxiliary product. 3 refs., 6 figs., 5 tabs.

  7. Selective flotation of phosphate minerals with hydroxamate collectors

    Science.gov (United States)

    Miller, Jan D.; Wang, Xuming; Li, Minhua

    2002-01-01

    A method is disclosed for separating phosphate minerals from a mineral mixture, particularly from high-dolomite containing phosphate ores. The method involves conditioning the mineral mixture by contacting in an aqueous in environment with a collector in an amount sufficient for promoting flotation of phosphate minerals. The collector is a hydroxamate compound of the formula; ##STR1## wherein R is generally hydrophobic and chosen such that the collector has solubility or dispersion properties it can be distributed in the mineral mixture, typically an alkyl, aryl, or alkylaryl group having 6 to 18 carbon atoms. M is a cation, typically hydrogen, an alkali metal or an alkaline earth metal. Preferably, the collector also comprises an alcohol of the formula, R'--OH wherein R' is generally hydrophobic and chosen such that the collector has solubility or dispersion properties so that it can be distributed in the mineral mixture, typically an alkyl, aryl, or alkylaryl group having 6 to 18 carbon atoms.

  8. Analysis of a solar collector field water flow network

    Science.gov (United States)

    Rohde, J. E.; Knoll, R. H.

    1976-01-01

    A number of methods are presented for minimizing the water flow variation in the solar collector field for the Solar Building Test Facility at the Langley Research Center. The solar collector field investigated consisted of collector panels connected in parallel between inlet and exit collector manifolds to form 12 rows. The rows were in turn connected in parallel between the main inlet and exit field manifolds to complete the field. The various solutions considered included various size manifolds, manifold area change, different locations for the inlets and exits to the manifolds, and orifices or flow control valves. Calculations showed that flow variations of less than 5 percent were obtainable both inside a row between solar collector panels and between various rows.

  9. Thermal analysis of gyrotron traveling-wave tube collector

    International Nuclear Information System (INIS)

    Zheng Zhiqing; Luo Yong; Jiang Wei; Tang Yong

    2013-01-01

    In order to solve cooling problem of the gyrotron traveling-wave tube(TWT) collector and guarantee the gyrotron TWT's reliability and stability, the electron trajectories in the gyrotron TWT are simulated using CST electron simulation software. Thermal analysis of the collector with finite element software ANSYS is performed. The ways of applying boundary that affects the distribution of collector temperature are compared. The influence of the water temperature and flow rate on collector temperature distribution under actual heat fluxes (boundary condition) is researched. The size and number of collector fins are optimized, and a relatively perfect structure is obtained finally. The result estimated by simulation is consistent with the experiment and proves that the model and method employed in this work are suitable. (authors)

  10. Mathematical modelling of unglazed solar collectors under extreme operating conditions

    DEFF Research Database (Denmark)

    Bunea, M.; Perers, Bengt; Eicher, S.

    2015-01-01

    average temperature levels at the evaporator. Simulation of these systems requires a collector model that can take into account operation at very low temperatures (below freezing) and under various weather conditions, particularly operation without solar irradiation.A solar collector mathematical model......Combined heat pumps and solar collectors got a renewed interest on the heating system market worldwide. Connected to the heat pump evaporator, unglazed solar collectors can considerably increase their efficiency, but they also raise the coefficient of performance of the heat pump with higher...... was found due to the condensation phenomenon and up to 40% due to frost under no solar irradiation. This work also points out the influence of the operating conditions on the collector's characteristics.Based on experiments carried out at a test facility, every heat flux on the absorber was separately...

  11. Test results, Industrial Solar Technology parabolic trough solar collector

    Energy Technology Data Exchange (ETDEWEB)

    Dudley, V.E. [EG and G MSI, Albuquerque, NM (United States); Evans, L.R.; Matthews, C.W. [Sandia National Labs., Albuquerque, NM (United States)

    1995-11-01

    Sandia National Laboratories and Industrial Solar Technology are cost-sharing development of advanced parabolic trough technology. As part of this effort, several configurations of an IST solar collector were tested to determine the collector efficiency and thermal losses with black chrome and black nickel receiver selective coatings, combined with aluminized film and silver film reflectors, using standard Pyrex{reg_sign} and anti-reflective coated Pyrex{reg_sign} glass receiver envelopes. The development effort has been successful, producing an advanced collector with 77% optical efficiency, using silver-film reflectors, a black nickel receiver coating, and a solgel anti-reflective glass receiver envelope. For each receiver configuration, performance equations were empirically derived relating collector efficiency and thermal losses to the operating temperature. Finally, equations were derived showing collector performance as a function of input insolation value, incident angle, and operating temperature.

  12. Project 'Colored solar collectors' - Annual report 2005

    Energy Technology Data Exchange (ETDEWEB)

    Schueler, A.; Chambrier, E. De; Roecker, Ch.; Scartezzini, J. -L.

    2005-12-15

    The architectural integration of thermal solar collectors into buildings is often limited by their black color, and the visibility of tubes and corrugations of the absorber sheets. A certain freedom in color choice would be desirable, but the colored appearance should not cause excessive performance degradation. Multilayered thin film interference filters on the collector glazing can produce a colored reflection, hiding the corrugated metal sheet, while transmitting the non-reflected radiation entirely to the absorber. These interference filters are designed and optimized by numerical simulation and shall be manufactured by the sol-gel dip-coating process. The proposed colored glazed solar collectors will be ideally suited for architectural integration into buildings, e.g. as solar active glass facades. The availability of thin film materials with a refractive index lower than that of silicon favors a higher solar transmission at a given value of visible reflectance. The feasibility of the sol-gel deposition of such low refractive index materials has been demonstrated. For the development of nanostructured materials, analytical methods such as electron microscopy are extremely helpful. Important techniques of substrate pretreatment, sample cleaving, polishing, mounting, and microscope handling have been acquired. First measurements yield images of nanostructures produced by the sol-gel dip-coating process. Nanocomposite Ti{sub x}Si{sub 1-x}O{sub 2} thin films provide a large range of refractive indices. Aiming a high efficiency of the colored reflection, Ti{sub x}Si{sub 1-x}O{sub 2} based multilayered coatings have been designed and subsequently prepared by sol-gel dip-coating. The energy efficiency M = R{sub VIS}/(100%-T{sub sol}) of the obtained colored reflection amounts up to 2.4. For a convincing demonstration sufficiently large samples of high quality are imperatively needed. An infrastructure for the handling of A4 sized samples has been established

  13. Study of thermal effects and optical properties of an innovative absorber in integrated collector storage solar water heater

    Science.gov (United States)

    Taheri, Yaser; Alimardani, Kazem; Ziapour, Behrooz M.

    2015-10-01

    Solar passive water heaters are potential candidates for enhanced heat transfer. Solar water heaters with an integrated water tank and with the low temperature energy resource are used as the simplest and cheapest recipient devices of the solar energy for heating and supplying hot water in the buildings. The solar thermal performances of one primitive absorber were determined by using both the experimental and the simulation model of it. All materials applied for absorber such as the cover glass, the black colored sands and the V shaped galvanized plate were submerged into the water. The water storage tank was manufactured from galvanized sheet of 0.0015 m in thickness and the effective area of the collector was 0.67 m2. The absorber was installed on a compact solar water heater. The constructed flat-plate collectors were tested outdoors. However the simulation results showed that the absorbers operated near to the gray materials and all experimental results showed that the thermal efficiencies of the collector are over than 70 %.

  14. Analysis of WWER 1000 collector cracking mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Matocha, K.; Wozniak, J. [Vitkovice J.S.C., Ostrava (Switzerland)

    1997-12-31

    The presentation reviews the large experimental program, started in 1993 in Vitkovice, where the main aim was: (1) a detailed study of strain and thermal ageing, dissolved oxygen content and temperature on subcritical crack growth in 10NiMo8.5 (10GN2MFA) steel, (2) a detailed study of the effect of high temperature water and tube expansion technology on fracture behaviour of ligaments between holes for heat exchange tubes, and (3) a detailed study of the effect of drilling, tube expansion technology and heat treatment on residual stresses on the surface of holes for heat exchange tubes. The aim of all these investigations was to find a dominant damage mechanism responsible for collector cracking to be able to judge the efficiency of implemented modifications and suggested countermeasures and to answer a very important question whether proper operation conditions (mainly water chemistry) make the operation of steam generators made in Vitcovice safe throughout the planned lifetime. 10 refs.

  15. Analysis of WWER 1000 collector cracking mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Matocha, K; Wozniak, J [Vitkovice J.S.C., Ostrava (Switzerland)

    1998-12-31

    The presentation reviews the large experimental program, started in 1993 in Vitkovice, where the main aim was: (1) a detailed study of strain and thermal ageing, dissolved oxygen content and temperature on subcritical crack growth in 10NiMo8.5 (10GN2MFA) steel, (2) a detailed study of the effect of high temperature water and tube expansion technology on fracture behaviour of ligaments between holes for heat exchange tubes, and (3) a detailed study of the effect of drilling, tube expansion technology and heat treatment on residual stresses on the surface of holes for heat exchange tubes. The aim of all these investigations was to find a dominant damage mechanism responsible for collector cracking to be able to judge the efficiency of implemented modifications and suggested countermeasures and to answer a very important question whether proper operation conditions (mainly water chemistry) make the operation of steam generators made in Vitcovice safe throughout the planned lifetime. 10 refs.

  16. Low-cost evacuated-tube solar collector. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Beecher, D. T.

    1981-02-10

    A prototype design for an evacuated tube air cooled solar collector module has been completed. A product cost study, based on the production of 60,000 of the prototype modules per year (approx. 1,000,000 square feet annually), estimates that the module as shipped would have a cost at inventory of $7.09 to $7.40 per square foot of aperture. Computer programs were developed to predict the optical and thermal performance of the module. Antireflective coatings (porous aluminum oxide) which could be formed by spraying or dipping were demonstrated but degraded more rapidly when exposed to a high humidity ambient than acid etched films. A selective black chromium oxide multi-layered graded film was vapor deposited which had an absorptivity of about 0.9 and an emissivity of 0.03. When the film was heated to temperatures of 400/sup 0/C in a gettered vacuum for as little as 24 hours, however, irreversible changes took place both between and within coating layers which resulted in ..cap alpha.. decreasing to about 0.73 and epsilon increasing to 0.14. The product cost studies indicate that module design changes are warranted to reduce product cost prior to tooling for production.

  17. Temperature calibration formula for activated charcoal radon collectors

    International Nuclear Information System (INIS)

    Cooper, Alexandre; Le, Thiem Ngoc; Iimoto, Takeshi; Kosako, Toshiso

    2011-01-01

    Radon adsorption by activated charcoal collectors such as PicoRad radon detectors is known to be largely affected by temperature and relative humidity. Quantitative models are, however, still needed for accurate radon estimation in a variable environment. Here we introduce a temperature calibration formula based on the gas adsorption theory to evaluate the radon concentration in air from the average temperature, collection time, and liquid scintillation count rate. On the basis of calibration experiments done by using the 25 m 3 radon chamber available at the National Institute of Radiological Sciences in Japan, we found that the radon adsorption efficiency may vary up to a factor of two for temperatures typical of indoor conditions. We expect our results to be useful for establishing standardized protocols for optimized radon assessment in dwellings and workplaces. - Research highlights: → The temperature effect on radon adsorption is proportional to αe β/T . → The calibration formula is CF(T,t)=3.1x10 -5 e (2887)/((T+273)) [1-e -0.080t ]. → The radon adsorption efficiency varies up to a factor of two for T = 8.5-31 o C. → The average temperature is suitable for estimating CF(T,t) in a fluctuating environment.

  18. Temperature calibration formula for activated charcoal radon collectors

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, Alexandre, E-mail: alexandre.cooper@gmail.co [Graduate School of Engineering, University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan); Le, Thiem Ngoc [Institute of Nuclear Science and Technology, Vietnam Atomic Energy Commission, 59 Ly Thuong Kiet, Hanoi (Viet Nam); Iimoto, Takeshi; Kosako, Toshiso [Graduate School of Engineering, University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan)

    2011-01-15

    Radon adsorption by activated charcoal collectors such as PicoRad radon detectors is known to be largely affected by temperature and relative humidity. Quantitative models are, however, still needed for accurate radon estimation in a variable environment. Here we introduce a temperature calibration formula based on the gas adsorption theory to evaluate the radon concentration in air from the average temperature, collection time, and liquid scintillation count rate. On the basis of calibration experiments done by using the 25 m{sup 3} radon chamber available at the National Institute of Radiological Sciences in Japan, we found that the radon adsorption efficiency may vary up to a factor of two for temperatures typical of indoor conditions. We expect our results to be useful for establishing standardized protocols for optimized radon assessment in dwellings and workplaces. - Research highlights: {yields} The temperature effect on radon adsorption is proportional to {alpha}e{sup {beta}/T}. {yields} The calibration formula is CF(T,t)=3.1x10{sup -5}e{sup (2887)/((T+273))} [1-e{sup -0.080t}]. {yields} The radon adsorption efficiency varies up to a factor of two for T = 8.5-31 {sup o}C. {yields} The average temperature is suitable for estimating CF(T,t) in a fluctuating environment.

  19. Pathways toward a low cost evacuated collector system

    Science.gov (United States)

    Hull, J. R.; Schertz, W. W.; Allen, J. W.; Ogallagher, J. J.; Winston, R.

    The goal of widespread use of solar thermal collectors will only be achieved when they are proven to be economically superior to competing energy sources. Evacuated tubular collectors appear to have the potential to achieve this goal. An advanced evacuated collector using nonimaging concentration under development at the University of Chicago and Argonne can achieve a 50% seasonal efficiency at heat delivery temperatures in excess of 170C. The same collector has an optical efficiency so that low temperature performance is also excellent. In this advanced collector design all of the critical components are enclosed in the vacuum, and the collector has an inherently long lifetime. The current cost of evacuated systems is too high, mainly because the volume of production has been too low to realize economies of mass production. It appears that certain design features of evacuated collectors can be changed (e.g., use of heat pipe absorbers) so as to introduce new system design and market strategy options that can reduce the balance of system cost.

  20. PERFORMANCE EVALUATION OF SOLAR COLLECTORS USING A SOLAR SIMULATOR

    Directory of Open Access Journals (Sweden)

    M. Norhafana

    2015-11-01

    Full Text Available Solar water heating systems is one of the applications of solar energy. One of the components of a solar water heating system is a solar collector that consists of an absorber. The performance of the solar water heating system depends on the absorber in the solar collector. In countries with unsuitable weather conditions, the indoor testing of solar collectors with the use of a solar simulator is preferred. Thus, this study is conducted to use a multilayered absorber in the solar collector of a solar water heating system as well as to evaluate the performance of the solar collector in terms of useful heat of the multilayered absorber using the multidirectional ability of a solar simulator at several values of solar radiation. It is operated at three variables of solar radiation of 400 W/m2, 550 W/m2 and 700 W/m2 and using three different positions of angles at 0º, 45º and 90º. The results show that the multilayer absorber in the solar collector is only able to best adapt at 45° of solar simulator with different values of radiation intensity. At this angle the maximum values of useful heat and temperature difference are achieved. KEYWORDS: solar water heating system; solar collector; multilayered absorber; solar simulator; solar radiation 

  1. Performance of a new solar air heater with packed-bed latent storage energy for nocturnal use

    International Nuclear Information System (INIS)

    Bouadila, Salwa; Kooli, Sami; Lazaar, Mariem; Skouri, Safa; Farhat, Abdelhamid

    2013-01-01

    Highlights: • A new solar air heater collector using a phase change material. • Experimental study of the new solar air heater collector with latent storage. • Energy and exergy analysis of the solar heater with latent storage collector. • Nocturnal use of solar air heater collector. - Abstract: An experimental study was conducted to evaluate the thermal performance of a new solar air heater collector using a packed bed of spherical capsules with a latent heat storage system. Using both first and second law of thermodynamics, the energetic and exegetic daily efficiencies were calculated in Closed/Opened and Opened cycle mode. The solar energy was stored in the packed bed through the diurnal period and extracted at night. The experimentally obtained results are used to analyze the performance of the system, based on temperature distribution in different localization of the collectors. The daily energy efficiency varied between 32% and 45%. While the daily exergy efficiency varied between 13% and 25%

  2. Effects of different collector’s area on the coupling of a thermosiphon collector and a single zone

    International Nuclear Information System (INIS)

    Chargui, R.; Sammouda, H.

    2014-01-01

    Graphical abstract: - Highlights: • We simulate a thermosiphon collector associated to a single zone using TRNSYS. • We examine the temperature of water in collector, in tank and in single zone. • We study the temporal evolution of the temperature and the energy for 11 h operation in January and 2880 h operation in winter. • The system gives good results in all operating states. • The use of solar energy in the residential building is interesting. - Abstract: The novelty of this paper is the coupling between a thermosiphon collector and a single zone with the following details; a thermosiphon system (TYPE 45) which uses the solar energy as an unlimited renewable energy to produce the heat by using an internal coupling of a flat plate collector and a storage tank in a closed loop realized in TRNSYS. Consequently, the user simply utilizes TYPE 45 as thermosiphon ready to be run, and a single zone (TYPE 19) is a complex type which is designed for residential buildings that can be specified by the user in order to obtain an acceptable heating within a house. The user specified the characteristics of the internal space, external weather conditions, walls, windows, and doors. To facilitate this description, the parameters and inputs for this component are organized in separate table according to a logical structure. According to us, the choice of this model of thermosiphon coupled with a single zone can have multiple interesting engineering applications, in particular ameliorating the mode of the heating in residential buildings. Two flat plate collectors of aperture area of 6 and 8 m 2 are modeled. The solar fraction of the entire system is used as the optimization parameter. The temperature of the water in the storage tank, the collector’s temperature, the temperature inside and outside the house, the solar fraction for different collector areas and the total energy were also measured in 11 h operation in January and 2880 h operation in winter. The average

  3. Fuzzy Approximate Model for Distributed Thermal Solar Collectors Control

    KAUST Repository

    Elmetennani, Shahrazed

    2014-07-01

    This paper deals with the problem of controlling concentrated solar collectors where the objective consists of making the outlet temperature of the collector tracking a desired reference. The performance of the novel approximate model based on fuzzy theory, which has been introduced by the authors in [1], is evaluated comparing to other methods in the literature. The proposed approximation is a low order state representation derived from the physical distributed model. It reproduces the temperature transfer dynamics through the collectors accurately and allows the simplification of the control design. Simulation results show interesting performance of the proposed controller.

  4. FLOW DISTRIBUTION IN A SOLAR COLLECTOR PANEL WITH HORIZONTAL FINS

    DEFF Research Database (Denmark)

    Fan, Jianhua; Shah, Louise Jivan; Furbo, Simon

    2005-01-01

    The objective of this work is to theoretically and experimentally investigate the flow and temperature distribution in a solar collector panel with an absorber consisting of horizontal fins. Fluid flow and heat transfer in the collector panel are studied by means of computational fluid dynamics...... (CFD) calculations. Further, experimental investigations of a 12.5 m² solar collector panel with 16 parallel connected horizontal fins are carried out. The flow distribution through the absorber is evaluated by means of temperature measurements on the backside of the absorber tubes. The measured...

  5. Theoretical flow investigations of an all glass evacuated tubular collector

    DEFF Research Database (Denmark)

    Shah, Louise Jivan; Furbo, Simon

    2007-01-01

    Heat transfer and flow structures inside all glass evacuated tubular collectors for different operating conditions are investigated by means of computational fluid dynamics. The investigations are based on a collector design with horizontal tubes connected to a vertical 14 manifold channel. Three...... the highest efficiency, the optimal inlet flow rate was around 0.4-1 kg/min, the flow structures in the glass tubes were relatively uninfluenced by the inlet flow rate, Generally, the results showed only small variations in the efficiencies. This indicates that the collector design is well working for most...

  6. A figure of merit for selective absorbers in flat plate solar water heaters

    CSIR Research Space (South Africa)

    Roberts, DE

    2013-12-01

    Full Text Available We derive from first principles an analytical expression for a figure of merit (FM) for a selective solar absorber in a single glazed flat plate water heater. We first show that the efficiency of a collector with an absorber with absorptance α...

  7. Spectral and directional radiation characteristics of thin-film coated isothermal semitransparent plates

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, R P; Viskanta, R

    1975-01-01

    An analysis is presented for predicting the effective spectral directional radiation characteristics of an isothermal, semitransparent sheet surrounded on both sides by massive dielectrics. The sheet can be coated with an optically thin film and used as selective cover plates for solar collectors. Directional and polarization effects and the spectral transmittance and reflectance are considered. Sample results for candidate materials are presented.

  8. Novel concept for producing energy integrating a solar collector with a man made mountain hollow

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Xinping [School of Civil Engineering and Mechanics, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei 430074 (China)], E-mail: zhxpmark@hotmail.com; Yang Jiakuan; Wang Jinbo; Xiao Bo [School of Environmental Science and Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road Wuhan, Hubei 430074 (China)

    2009-03-15

    The concept of the solar chimney thermal power technology was proven with the successful operation of the Manzanares prototype built in the 1980s. However, all previous attempts at producing energy from a commercial solar chimney thermal power plant on a large scale have failed because of bad engineering and safety. A novel concept for producing energy by integrating a solar collector with a mountain hollow is presented and described. Solar energy is collected in the collector and heats the ground, which is used to store heat energy and heat the indoor air. Then, the hot air is forced by the pressure difference between it and the ambient air to move along the tilted segment and up the vertical segment of the 'chimney', driving the turbine generators to generate electricity. The mountain hollow, formed by excavation in a large-elevation mountain, can avoid the safety issues of erecting a gigantic concrete chimney, which is needed for commercial solar chimney thermal power plants. Furthermore, it can also save a great amount of construction materials for constructing a robust chimney structure and reduce the energy cost to a level less than that of a clean coal power plant, providing a good solution to the reclamation and utilization of undeveloped mountains, especially in mountainous countries.

  9. Novel concept for producing energy integrating a solar collector with a man made mountain hollow

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xinping [School of Civil Engineering and Mechanics, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei 430074 (China); Yang, Jiakuan; Wang, Jinbo; Xiao, Bo [School of Environmental Science and Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road Wuhan, Hubei 430074 (China)

    2009-03-15

    The concept of the solar chimney thermal power technology was proven with the successful operation of the Manzanares prototype built in the 1980s. However, all previous attempts at producing energy from a commercial solar chimney thermal power plant on a large scale have failed because of bad engineering and safety. A novel concept for producing energy by integrating a solar collector with a mountain hollow is presented and described. Solar energy is collected in the collector and heats the ground, which is used to store heat energy and heat the indoor air. Then, the hot air is forced by the pressure difference between it and the ambient air to move along the tilted segment and up the vertical segment of the 'chimney', driving the turbine generators to generate electricity. The mountain hollow, formed by excavation in a large-elevation mountain, can avoid the safety issues of erecting a gigantic concrete chimney, which is needed for commercial solar chimney thermal power plants. Furthermore, it can also save a great amount of construction materials for constructing a robust chimney structure and reduce the energy cost to a level less than that of a clean coal power plant, providing a good solution to the reclamation and utilization of undeveloped mountains, especially in mountainous countries. (author)

  10. Novel concept for producing energy integrating a solar collector with a man made mountain hollow

    International Nuclear Information System (INIS)

    Zhou Xinping; Yang Jiakuan; Wang Jinbo; Xiao Bo

    2009-01-01

    The concept of the solar chimney thermal power technology was proven with the successful operation of the Manzanares prototype built in the 1980s. However, all previous attempts at producing energy from a commercial solar chimney thermal power plant on a large scale have failed because of bad engineering and safety. A novel concept for producing energy by integrating a solar collector with a mountain hollow is presented and described. Solar energy is collected in the collector and heats the ground, which is used to store heat energy and heat the indoor air. Then, the hot air is forced by the pressure difference between it and the ambient air to move along the tilted segment and up the vertical segment of the 'chimney', driving the turbine generators to generate electricity. The mountain hollow, formed by excavation in a large-elevation mountain, can avoid the safety issues of erecting a gigantic concrete chimney, which is needed for commercial solar chimney thermal power plants. Furthermore, it can also save a great amount of construction materials for constructing a robust chimney structure and reduce the energy cost to a level less than that of a clean coal power plant, providing a good solution to the reclamation and utilization of undeveloped mountains, especially in mountainous countries

  11. Development and evaluation of a ceiling ventilation system enhanced by solar photovoltaic thermal collectors and phase change materials

    International Nuclear Information System (INIS)

    Lin, Wenye; Ma, Zhenjun; Sohel, M. Imroz; Cooper, Paul

    2014-01-01

    Highlights: • A novel ceiling ventilation system enhanced by PVT and PCMs was proposed. • PCM was used to increase the local thermal mass and to serve as a storage unit. • The proposed system can enhance indoor thermal comfort in winter and summer. - Abstract: This paper presents the development and performance evaluation of a novel ceiling ventilation system integrated with solar photovoltaic thermal (PVT) collectors and phase change materials (PCMs). The PVT collectors are used to generate electricity and provide low grade heating and cooling energy for buildings by using winter daytime solar radiation and summer night-time sky radiative cooling, respectively. The PCM is integrated into the building ceiling as a part of the ceiling insulation and at the same time, as a centralized thermal energy storage to temporally store low grade energy collected from the PVT collectors. The performance of the proposed system was numerically evaluated based on a Solar Decathlon house using TRNSYS. The results showed that, in winter conditions, the proposed PVT–PCM integrated ventilation system can significantly improve the indoor thermal comfort of passive buildings without using air-conditioning systems with a maximum air temperature rise of 23.1 °C from the PVT collectors. Compared with the system using PCM but without using PVT collectors, the coefficient of thermal comfort enhancement in the kitchen, dining room and living room of the case building studied using the proposed system improved from almost zero to 0.9823 while the coefficient of thermal comfort enhancement in the study room improved from 0.0060 to 0.9921. In summer conditions, the proposed system can also enhance indoor thermal comfort through night-time sky radiative cooling

  12. Air and water pollution remediation. A fixed bed reactor made of UV lamps and glass fiber plates coated with TiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Esterkin, C.R.; Negro, A.C.; Alfano, O.M.; Cassano, A.E. [Inst. de Desarrollo Tecnologico para la Industria Quimica, INTEC (UNL-CONICET), Santa Fe (Argentina)

    2003-07-01

    In a previous paper, the modeling and experimental verification of the radiation field inside a reactor made up of TiO{sub 2} coated, parallel, flat glass fiber meshes, bilaterally UV irradiated was accomplished. In this work, we study the degradation of tricloroethylene (TCE) in an air stream with different values of the pollutant feed concentration, under operating conditions where kinetic control of the process is established. A langmuir-hinshelwood type kinetic expression is proposed and the kinetic parameters are estimated. The results show good agreement between predictions derived from the kinetic expression and the experimental concentrations of TCE data at the exit of the reactor. (orig.)

  13. A total cost perspective on use of polymeric materials in solar collectors – Importance of environmental performance on suitability

    International Nuclear Information System (INIS)

    Carlsson, Bo; Persson, Helena; Meir, Michaela; Rekstad, John

    2014-01-01

    Highlights: • A polymeric solar collector system was compared with two traditional ones. • It was found the best in terms of climatic performance per solar heat collected. • The differences in climatic cost between the systems compared however are small. • The low climatic cost makes solar heating better compared to natural gas heating. • Use of Ecoindicator 99 for environmental cost makes solar heating even better. - Abstract: To assess the suitability of solar collector systems in which polymeric materials are used versus those in which more traditional materials are used, a case study was undertaken. In this case study a solar heating system with polymeric solar collectors was compared with two equivalent but more traditional solar heating systems: one with flat plate solar collectors and one with evacuated tube solar collectors. To make the comparison, a total cost accounting approach was adopted. The life cycle assessment (LCA) results clearly indicated that the polymeric solar collector system is the best as regards climatic and environmental performance when they are expressed in terms of the IPPC 100 a indicator and the Ecoindicator 99, H/A indicator, respectively. In terms of climatic and environmental costs per amount of solar heat collected, the differences between the three kinds of collector systems were small when compared with existing energy prices. With the present tax rates, it seems unlikely that the differences in environmental and climatic costs will have any significant influence on which system is the most favoured, from a total cost point of view. In the choice between a renewable heat source and a heat source based on the use of a fossil fuel, the conclusion was that for climatic performance to be an important economic factor, the tax or trade rate of carbon dioxide emissions must be increased significantly, given the initial EU carbon dioxide emission trade rate. The rate would need to be at least of the same order of magnitude

  14. Flat solar collector an approach to its evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Sonino, T [Israel Atomic Energy Commission, Yavne. Soreq Nuclear Research Center

    1977-01-01

    The flat solar collector is the most widely used device for the utilization of solar energy, but its energetic and economic values are still debated. A preliminary energy and economic analysis is presented. The energy analysis indicates that the energy needed to produce one solar collector is equivalent to the electricity consumed by an electric water heater in roughly three months. The economic analysis indicates that the pay-back time for a solar collector varies from 5.5 to 7.7 yr. according to the discount rate. The economic analysis from a national point of view indicates that the use of solar collectors for domestic purposes could only reduce electricity consumption in Israel by 10%.

  15. Bilinear reduced order approximate model of parabolic distributed solar collectors

    KAUST Repository

    Elmetennani, Shahrazed; Laleg-Kirati, Taous-Meriem

    2015-01-01

    This paper proposes a novel, low dimensional and accurate approximate model for the distributed parabolic solar collector, by means of a modified gaussian interpolation along the spatial domain. The proposed reduced model, taking the form of a low

  16. [Naturalists, collectors and theoreticians of museology].

    Science.gov (United States)

    Arabas, Iwona

    2009-01-01

    The origins of the contemporary collectorship dates from times when the sameness of art and science was commonly accepted. In those days relics of the ancient past and natural individuals of newly discovered lands were presented at the same time. Cosmological character of the collections manifested the tenacity of recognition and representation of the surrounding reality. A great impact on completion of collections of curiosities in Europe had Netherlands, and in the basin of Baltic Sea a remarkable significance was gained by Hanseatic Gdańsk. Collections of Jakub Breyn, Jakub Klein and Gotfryd Reyger became famous then. In the same way were imported individuals for Anna Jabłonowska that composed one of the most interesting European collections. In course of time merging such a great multiplicity of collections was beyond collectors' power and museum pieces from collections of curiosities were parcelled out. It was a real beginning of specialistic museums. A role of museum for science results from its function of methodical organizing collections that can be used by research workers. However, although the aims of scientific and museum centres are different, they come together on the occasion of museum recognition works when museums' workers borrow essential knowledge and methods from resources of science, and scientists search for useful research materials in museum resources.

  17. Parabolic Trough Solar Collector Initial Trials

    Directory of Open Access Journals (Sweden)

    Ghalya Pikra

    2012-03-01

    Full Text Available This paper discusses initial trials of parabolic trough solar collector (PTSC in Bandung. PTSC model consists of concentrator, absorber and tracking system. Concentrator designs are made with 2m aperture width, 6m length and 0.75m focal distance. The design is equipped with an automatic tracking system which is driven using 12V and 24Watt DC motor with 0.0125rpm rotational speed. Absorber/receiver is designed with evacuated tube type, with 1 inch core diameter and tube made of AISI304 and coated with black oxide, the outer tube is borosilicate glass with a 70 mm diameter and 1.5 m length. Working fluid stored in single type of thermal storage tank, a single phase with 37.7 liter volume. PTSC model testing carried out for 2 hours and 10 minutes produces heat output and input of 11.5 kW and 0.64 kW respectively. 

  18. Performance evaluation for solar collectors in Taiwan

    International Nuclear Information System (INIS)

    Chang, T.P.

    2009-01-01

    In this paper, the global irradiation observed in Taiwan from 1990 to 1999 was used to estimate the optimal tilt angle for solar collectors. The observed data are resolved into diffusion and beam components, and transformed into instantaneous time frames using mathematical models. The energy gain on installing a single-axis tracked panel as compared to a traditional fixed panel is originally analyzed theoretically. In addition to the observation data, both types of radiation will be taken into account for comparison, i.e. both extraterrestrial radiation and global radiation predicted using empirical models. The results show that the yearly optimal angles for six selected stations are about 0.95 and 0.88 times their latitudes for extraterrestrial and predicted radiation, respectively. All of the observed irradiations are less than the predicted values for all times and stations, consequently resulting in a flatter tilt angle, with a few exceptions in summer. Since Taipei has the lowest clearness index, its yearly optimal angle calculated from observed data shows the greatest discrepancy when compared to its latitude. By employing a tracked panel, the yearly gains calculated from the observed data lie between 14.3% and 25.3%, which is significantly less than those from the extraterrestrial and predicted radiations

  19. Theoretical modeling of condensation of steam outside different vertical geometries (tube, flat plates) in the presence of noncondensable gases like air and helium

    International Nuclear Information System (INIS)

    Ganguli, Arijit; Patel, A.G.; Maheshwari, N.K.; Pandit, A.B.

    2008-01-01

    Condensation of steam coming out from the coolant pipe during a loss of coolant accident (LOCA) plays a key role in removing heat from the primary containment of the advanced nuclear reactor (ANR). The presence of large mass fractions of air (W air = 0.25-0.9) and a small mass fraction of helium (W He = 0.017-0.083) reduces the overall heat transfer coefficient (HTC) substantially. The present work emphasizes on the issue that modeling the diffusion of water-vapor through the gas-liquid interface is the key to give good predictions in HTC. In this, condensation conductivity and effective diffusivity plays a key role. Therefore, modifications have been made in the derivation for calculation of condensation conductivity in the case of steam-air mixture and effective diffusivity (in the case of multicomponent mixture). The model validation has been done with the experimental data of Dehbi et al. [Dehbi, A.A., Golay, M.W., Kazimi, M.S., 1991. National Conference of Heat Transfer AIChE Symposium Series, pp. 19-28] and Anderson et al. [Anderson, M.H., Herranz, L.E., Corradini, M.L., 1998. Experimental analysis of heat transfer within the AP600 containment under postulated accident conditions. Nucl. Eng. Des. 185, 153-172] and other analytical models available in the literature [Herranz, L.E., Anderson, M.H., Corradini, M.H., 1998a. The effect of light gases in noncondensable mixtures on condensation heat transfer. Nucl. Eng. Des. 183, 133-150; Herranz, L.E., Anderson, M.H., Corradini, M.L., 1998b. A diffusion layer model for steam condensation within the AP600 containment. Nucl. Eng. Des. 185, 153-172; Peterson, P.F., Schrock, Y.E., Kageyama, T., 1993. Diffusion layer theory for turbulent vapor condensation with noncondensable gases. J. Heat Transf., 115; Dehbi, A.A., Golay, M.W., Kazimi, M.S., 1991. National Conference of Heat Transfer AIChE Symposium Series, pp. 19-28]. Since the validations of the results were found satisfactory, the datasets [Dehbi, A.A., Golay, M

  20. Means of increasing efficiency of CPC solar energy collector

    Science.gov (United States)

    Chao, B.T.; Rabl, A.

    1975-06-27

    A device is provided for improving the thermal efficiency of a cylindrical radiant energy collector. A channel is placed next to and in close proximity to the nonreflective side of an energy reflective wall of a cylindrical collector. A coolant is piped through the channel and removes a portion of the nonreflective energy incident on the wall which is absorbed by the wall. The energy transferred to the coolant may be utilized in a useful manner.