WorldWideScience

Sample records for plate thermal collectors

  1. 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.

  2. The Effect of the Configuration of the Absorber on the Performance of Flat Plate Thermal Collector

    OpenAIRE

    Yan, Moyu; Qu, Ming; Peng, Steve

    2016-01-01

    In this study, a numerical thermal analysis for a new designed flat plate thermal collector was conducted through modeling. The new flat plate thermal collector has ellipse shaped tubes inside a wavy shaped absorber, which is made of stainless steel. For the comparison, the conventional flat plate thermal collector with circular copper tubes served as a base case was also modeled. Hottel-Whillier equations were utilized to formulate thermal networks for both models developed in Engineering Eq...

  3. Increasing thermal efficiency of solar flat plate collectors

    Science.gov (United States)

    Pona, J.

    A study of methods to increase the efficiency of heat transfer in flat plate solar collectors is presented. In order to increase the heat transfer from the absorber plate to the working fluid inside the tubes, turbulent flow was induced by installing baffles within the tubes. The installation of the baffles resulted in a 7 to 12% increase in collector efficiency. Experiments were run on both 1 sq ft and 2 sq ft collectors each fitted with either slotted baffles or tubular baffles. A computer program was run comparing the baffled collector to the standard collector. The results obtained from the computer show that the baffled collectors have a 2.7% increase in life cycle cost (LCC) savings and a 3.6% increase in net cash flow for use in domestic hot water systems, and even greater increases when used in solar heating systems.

  4. Theoretical analysis of solar thermal collector and flat plate bottom reflector with a gap between them

    OpenAIRE

    Hiroshi Tanaka

    2015-01-01

    Augmentation of solar radiation absorbed on a flat plate solar thermal collector by a flat plate bottom reflector was numerically determined when there was a gap between the collector and reflector. The inclination of both the collector and reflector was assumed to be adjustable according to the season. A mirror-symmetric plane of the collector to the reflector was introduced, and a graphical model was proposed to calculate the amount of solar radiation reflected by the reflector and then abs...

  5. A Dynamic Multinode Model for Component-Oriented Thermal Analysis of Flat-Plate Solar Collectors

    OpenAIRE

    Reiter, Christoph N.; Christoph Trinkl; Wilfried Zörner; Hanby, Vic I.

    2015-01-01

    A mathematical model of a flat-plate solar collector was developed on the basis of the physical principles of optics and heat transfer in order to determine collector’s component temperatures as well as collector efficiency. In contrast to many available models, the targeted use of this dynamic model is the detailed, theoretical investigation of the thermal behaviour of newly developed or adjusted collector designs on component level, for example, absorber, casing, or transparent cover. The d...

  6. Theoretical analysis of solar thermal collector and flat plate bottom reflector with a gap between them

    Directory of Open Access Journals (Sweden)

    Hiroshi Tanaka

    2015-11-01

    Full Text Available Augmentation of solar radiation absorbed on a flat plate solar thermal collector by a flat plate bottom reflector was numerically determined when there was a gap between the collector and reflector. The inclination of both the collector and reflector was assumed to be adjustable according to the season. A mirror-symmetric plane of the collector to the reflector was introduced, and a graphical model was proposed to calculate the amount of solar radiation reflected by the reflector and then absorbed on the collector. The performance was analyzed for three typical days at a latitude of 30°N. Solar radiation absorbed on the collector can be increased by the bottom reflector even if there is a gap between the collector and reflector. The optimum inclinations of both the collector and reflector are almost the same while the gap length is less than the lengths of the collector and reflector. However, the range of inclination of the reflector that can increase the solar radiation absorbed on the collector decreases with an increase in gap length, and the solar radiation absorbed on the collector rapidly decreased with an increase in the gap length when the reflector and/or collector were not set at a proper angle.

  7. 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.

  8. Solar thermal collectors

    Science.gov (United States)

    Aranovitch, E.

    Thermal processes in solar flat plate collectors are described and evaluated analytically, and numerical models are presented for evaluating the performance of various designs. A flat plate collector consists of a black absorber plate which transfers absorbed heat to a fluid, a cover which limits thermal losses, and insulation to prevent backlosses. Calculated efficiencies for the collectors depend on the radiation absorbed, as well as IR losses due to natural convection, conduction, and radiation out of the collector. Formulations for the global emittance and heat transfer, as well as losses and their dependence on the Nusselt number and Grashof number are defined. Consideration is given to radiation transmission through transparent covers and Fresnel reflections at interfaces in the cover material. Finally, the performance coefficients for double-glazed and selective surface flat plate collectors are examined.

  9. 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.

  10. A Dynamic Multinode Model for Component-Oriented Thermal Analysis of Flat-Plate Solar Collectors

    Directory of Open Access Journals (Sweden)

    Christoph N. Reiter

    2015-01-01

    Full Text Available A mathematical model of a flat-plate solar collector was developed on the basis of the physical principles of optics and heat transfer in order to determine collector’s component temperatures as well as collector efficiency. In contrast to many available models, the targeted use of this dynamic model is the detailed, theoretical investigation of the thermal behaviour of newly developed or adjusted collector designs on component level, for example, absorber, casing, or transparent cover. The defined model is based on a multinode network (absorber, fluid, glazing, and backside insulation containing the relevant physical equations to transfer the energy. The heat transfer network covers heat conduction, convection, and radiation. Furthermore, the collector optics is defined for the plane glazing and the absorber surface and also considers interactions between them. The model enables the variation of physical properties considering the geometric parameters and materials. Finally, the model was validated using measurement data and existing efficiency curve models. Both comparisons proved high accuracy of the developed model with deviation of up to 3% in collector efficiency and 1 K in component temperatures.

  11. Multi-objective genetic algorithm for the optimization of a flat-plate solar thermal collector.

    Science.gov (United States)

    Mayer, Alexandre; Gaouyat, Lucie; Nicolay, Delphine; Carletti, Timoteo; Deparis, Olivier

    2014-10-20

    We present a multi-objective genetic algorithm we developed for the optimization of a flat-plate solar thermal collector. This collector consists of a waffle-shaped Al substrate with NiCrOx cermet and SnO(2) anti-reflection conformal coatings. Optimal geometrical parameters are determined in order to (i) maximize the solar absorptance α and (ii) minimize the thermal emittance ε. The multi-objective genetic algorithm eventually provides a whole set of Pareto-optimal solutions for the optimization of α and ε, which turn out to be competitive with record values found in the literature. In particular, a solution that enables α = 97.8% and ε = 4.8% was found.

  12. Conclusions and recommendations for the testing of flat-plate solar collector thermal performance and durability

    Science.gov (United States)

    Waksman, D.; Thomas, W. C.

    1984-12-01

    The results of studies, by the National Bureau of Standards, of the reliability and durability of eight different types of flat plate solar collectors representative of equipment available in 1977 are reported. The installations were made in four sites believed to typify various U.S. climates. The stability of the thermal performance and material properties was tracked, and measured again after moving the units inside for exposure to artificial sunlight. The stagnation measurement techniques employed to evaluate the collectors were judged adequate, provided the tests are made on-site and out of doors. It is noted that the instrumentation used to gather sufficient data for valid analyses may experience performance decrements due to the necessarily long monitoring intervals, i.e., several years.

  13. Theoretical investigation on thermal performance of heat pipe flat plate solar collector with cross flow heat exchanger

    Science.gov (United States)

    Xiao, Lan; Wu, Shuang-Ying; Zhang, Qiao-Ling; Li, You-Rong

    2012-07-01

    Based on the heat transfer characteristics of absorber plate and the heat transfer effectiveness-number of heat transfer unit method of heat exchanger, a new theoretical method of analyzing the thermal performance of heat pipe flat plate solar collector with cross flow heat exchanger has been put forward and validated by comparisons with the experimental and numerical results in pre-existing literature. The proposed theoretical method can be used to analyze and discuss the influence of relevant parameters on the thermal performance of heat pipe flat plate solar collector.

  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

    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...... 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.......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...

  15. 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....

  16. 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.

  17. Analysis of the Thermal Performance of a Solar Water Heating System with Flat Plate Collectors in a Temperate Climate

    OpenAIRE

    Ayompe, Lacour; DUFFY Aidan

    2013-01-01

    The thermal performance of a solar water heating system with 4 m2 flat plate collectors in Dublin, Ireland is presented in this paper. The experimental setup consisted of a commercially available forced circulation domestic scale system fitted with an automated sub‐system that controlled hot water draw‐offs and the operation of an auxiliary immersion heater. The system was tested over a year and the maximum recorded collector outlet fluid temperature was 70.4 oC while the maximum water temper...

  18. Solar tests of aperture plate materials for solar thermal dish collectors

    Science.gov (United States)

    Jaffe, L. D.

    1984-11-01

    If a malfunction occurs in a solar thermal point-focus distributed receiver power plant while a concentrator is pointed at the sun, motion of the concentrator may stop. As the sun moves relative to the earth, the spot of concentrated sunlight then slowly walks off the receiver aperture, across the receiver face plate, and perhaps across adjacent portions of the concentrator. Intense local heating by the concentrated sunlight may damage or destroy these parts. The behavior of various materials under conditions simulating walk-off of a parabolic dish solar collector were evaluated. Each test consisted of exposure to concentrated sunlight at a peak flux density of about 7000 kW/square meter for 15 minutes. Types of materials tested included graphite, silicon carbide, silica, various silicates, alumina, zirconia, aluminum, copper, steel, and polytetrafluroethylene. The only material that neither cracked nor melted was grade G-90 graphite. Grade CS graphite, a lower cost commercial grade, cracked half-way across, but did not fail apart. Both of these grades are medium-grain extruded graphites. A graphite cloth (graphitized polyacrylonitrile) showed fair performance when tested as a single thin ply; it might be useful as a multi-ply assembly. High purity slipcast silica showed some promise also.

  19. Solar tests of aperture plate materials for solar thermal dish collectors

    Science.gov (United States)

    Jaffe, L. D.

    1984-01-01

    If a malfunction occurs in a solar thermal point-focus distributed receiver power plant while a concentrator is pointed at the sun, motion of the concentrator may stop. As the sun moves relative to the earth, the spot of concentrated sunlight then slowly walks off the receiver aperture, across the receiver face plate, and perhaps across adjacent portions of the concentrator. Intense local heating by the concentrated sunlight may damage or destroy these parts. The behavior of various materials under conditions simulating walk-off of a parabolic dish solar collector were evaluated. Each test consisted of exposure to concentrated sunlight at a peak flux density of about 7000 kW/square meter for 15 minutes. Types of materials tested included graphite, silicon carbide, silica, various silicates, alumina, zirconia, aluminum, copper, steel, and polytetrafluroethylene. The only material that neither cracked nor melted was grade G-90 graphite. Grade CS graphite, a lower cost commercial grade, cracked half-way across, but did not fail apart. Both of these grades are medium-grain extruded graphites. A graphite cloth (graphitized polyacrylonitrile) showed fair performance when tested as a single thin ply; it might be useful as a multi-ply assembly. High purity slipcast silica showed some promise also.

  20. 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.

  1. Development of flat-plate solar thermal collectors equipped with aerogel sandwiched absorber

    Energy Technology Data Exchange (ETDEWEB)

    Goto, Yusuke; Izumi, Hiroaki; Aizawa, Mamoru [Dynax Corp. (Japan); Yugami, Hiroo [Graduate School of Engineering, Tohoku Univ. (Japan)

    2004-07-01

    It is important to utilize the solar energy efficiently. However, conventional solar thermal collectors have some drawbacks of high cost, heavy weight and low temperature output. These drawbacks prevent from spreading of the market of solar thermal collectors, especially in Japan. To find a solution to the problems, we propose an absorber / aerogel one-piece structure for high temperature solar thermal collectors. TiOxNy and silica aerogel were employed as a selectively solar-absorbing coating of absorber and as an optically transparent thermal insulator, respectively. Selectively solar-absorbing coatings must show lower reflectance and lower emittance. We have developed selectively solar-absorbing coatings of which optical property was {alpha} = 98.5, {epsilon} = 3 %. Wet coating of newly designed TiOxNy precursor enabled fabricating selectively solar-absorbing coatings, easily. Shrinkage of silica aerogel had to be minimized to produce an absorber / aerogel one-piece structure. Selectively solar-absorbing coatings and silica aerogel were prepared via sol-gel processing. (orig.)

  2. High performance flat plate solar collector

    Science.gov (United States)

    Lansing, F. L.; Reynolds, R.

    1976-01-01

    The potential use of porous construction is presented to achieve efficient heat removal from a power producing solid and is applied to solar air heaters. Analytical solutions are given for the temperature distribution within a gas-cooled porous flat plate having its surface exposed to the sun's energy. The extracted thermal energy is calculated for two different types of plate transparency. Results show the great improvement in performance obtained with porous flat plate collectors as compared with analogous nonporous types.

  3. 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 b...

  4. Nongray-radiative and convective-conductive thermal coupling in Teflon-glazed, selective-black, flat-plate solar collectors

    Science.gov (United States)

    Edwards, D. K.; Rhee, S. J.

    1984-05-01

    An analysis is presented comparing Teflon film with glass for the inner glazing of a double-glazed selective-black, flat-plate solar collector. The effect of spacing between glazings and between the inner glazing and absorber plate is examined. It is shown that a 12.5-micron Teflon film is superior to glass for the inner glazing of a selective-black collector, because the advantage of its high solar transparency overwhelms the disadvantage of its infrared transparency. A too-small spacing between a selective-black absorber and its inner cover short-circuits the desirable thermal radiation resistance offered by a selective-black absorber plate. Account is taken of spectral variations in the radiation properties of glass, Teflon, and the absorber plate. Allowance is made for the fact that critical Rayleigh number is lower for a plastic film inner glazing than for a glass one.

  5. Indoor thermal performance evaluation of Daystar solar collector

    Science.gov (United States)

    Shih, K., Sr.

    1977-01-01

    The test procedures used and results obtained from a test program to obtain thermal performance data on a Daystar Model 21B, S/N 02210, Unit 2, liquid solar collector under simulated conditions are described. The test article is a flat plate solar collector using liquid as a heat transfer medium. The absorber plate is copper and coated with black paint. Between the tempered low iron glass and absorber plate is a polycarbonate trap used to suppress convective heat loss. The collector incorporates a convector heat dump panel to limit temperature excursions during stagnation. The following tests were conducted: (1) collector thermal efficiency; (2) collector time constant; (3) collector incident angle modifier; (4) collector heat loss coefficient; and (5) collector stagnation.

  6. A 2-dimensional heat transfer analysis of a sheet-and-tube flat plate PV/thermal collector

    Energy Technology Data Exchange (ETDEWEB)

    Carriere, J.; Harrison, S. [Queen' s Univ., Kingston, ON (Canada). Dept. of Mechanical and Materials Engineering Solar Calorimetry Lab

    2008-08-15

    Temperature gradients in photovoltaic/thermal (PV/T) systems can have a significant impact on the reliability and life-span of system components. However, many simple PV/T models do not consider temperature gradients. In this study, a detailed heat transfer model was used to quantify temperature gradients within a PV/T panel in order to predict thermal and electrical performance as a function of fluid and atmospheric temperatures. The PV/T system consisted of a PV laminate bonded to a thermal collector. A glass cover was used as a secondary glazing system. The effect of increasing the thermal resistance between the various layers in the construction was evaluated in order to measure the temperature gradient through the absorber thickness. A 2-D finite difference model of heat flow in the collector was conducted in order to study the magnitude of the temperature gradient. Steady-state heat flow was calculated along the width of the system as well as between the layers. Heat flux was calculated to the centre of each element. Total absorptivity in each layer was determined by adding the absorption of each portion of the spectrum. Heat losses through the top of the collector were estimated using a 1-D analysis. The study showed that current methods of calculating fin efficiency are not valid when temperature gradients are not considered. Future studies will examine the effect of thermal expansion and shear stresses. 9 refs., 8 figs.

  7. A high performance porous flat-plate solar collector

    Science.gov (United States)

    Lansing, F. L.; Clarke, V.; Reynolds, R.

    1979-01-01

    A solar collector employing a porous matrix as a solar absorber and heat exchanger is presented and its application in solar air heaters is discussed. The collector is composed of a metallic matrix with a porous surface which acts as a large set of cavity radiators; cold air flows through the matrix plate and exchanges heat with the thermally stratified layers of the matrix. A steady-state thermal analysis of the collector is used to determine collector temperature distributions for the cases of an opaque surface matrix with total absorption of solar energy at the surface, and a diathermanous matrix with successive solar energy absorption at each depth. The theoretical performance of the porous flat plate collector is shown to exceed greatly that of a solid flat plate collector using air as the working medium for any given set of operational conditions. An experimental collector constructed using commercially available, low cost steel wool as the matrix has been found to have thermal efficiencies from 73 to 86%.

  8. 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.

  9. 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.

  10. Outdoor thermal efficiency evaluation of the Ying solar collector

    Science.gov (United States)

    1978-01-01

    The test procedure used and the test results obtained during an evaluation test program to obtain thermal efficiency performance data are presented. The flat plate collector used water/prestone antifreeze solution as the working fluid.

  11. MINICHANNEL-TUBE SOLAR THERMAL COLLECTORS FOR LOW TO MEDIUM TEMPERATURE APPLICATIONS

    OpenAIRE

    Duong, Thuc

    2015-01-01

    Novel minichannel-tube solar thermal collectors for low to medium temperature applications are introduced. Two types of minichannel solar thermal collectors are analyzed experimentally: aluminum minichannel solar collector for low temperature applications, and copper minichannel solar collector for low to medium temperature applications.The aluminum minichannel solar collector has been tested for over a year alongside a conventional copper flat-plate solar collector of similar dimensions as t...

  12. Electrostatic particle collector with improved features for installing and/or removing its collector plates

    Energy Technology Data Exchange (ETDEWEB)

    Siegfried, Matthew J.; Radford, Daniel R.; Huffman, Russell K.

    2017-04-04

    An electrostatic particle collector may generally include a housing having sidewalls extending lengthwise between a first end and a second end. The housing may define a plate slot that extends heightwise within the housing between a top end and a bottom end. The housing may further include a plate access window that provides access to the bottom end of the plate slot. The collector may also include a collector plate configured to be installed within the plate slot that extends heightwise between a top edge and a bottom edge. Additionally, when the collector plate is installed within the plate slot, the bottom edge of the collector plate may be accessible from an exterior of the housing via the plate access window so as to allow the bottom edge of the collector plate to be moved relative to the housing to facilitate removal of the collector plate from the housing.

  13. High temperature flat plate solar collector

    Energy Technology Data Exchange (ETDEWEB)

    Hozumi, S.; Aso, S.; Ebisu, K.; Uchino, H.

    1981-04-01

    Improvements in the efficiency of collectors are of great importance for extending the utilization of solar energy for heating and cooling in homes. A highly efficient collector makes the system size small and decreases the system cost effectively. From the view of the amount of energy collected, the efficient collector has a multiple effect, not only because of the high increase in instantaneous efficiency, but also because of the large usable intensity range of the insolation. On the basis of a functional analysis for a flat collector, the materials and parameters were selected and optimized, and a new high temperature flat collector was designed. The collector has 2 panes. The first pane is low iron glass and the second pane is a thin film of fluorinated ethylene-propylene copolymer. The overall solar transmittance for the two panes is 0.89. The collecting panel and its water paths were formed by means of welding and hydraulic expansion. The selective absorbing surface consists of colored stainless steel whose absorption characteristic is 0.89 and emission characteristic is 0.16. The thermal insulator preventing backward heatloss consists of double layers of urethane foam and glass wool. Furthermore, the sustained method for the second pane is contrived so as to prevent water condensation on the panes and excessive elevation of the absorber temperature during no load heating.

  14. Numerical 3-D heat flux simulations on flat plate solar collectors

    Energy Technology Data Exchange (ETDEWEB)

    Villar, N. Molero; Lopez, J.M. Cejudo; Munoz, F. Dominguez; Garcia, E. Rodriguez; Andres, A. Carrillo [Grupo de Energetica, Escuela Tecnica Superior de Ingenieros Industriales, UMA, Plaza El Ejido s/n, 29013 Malaga (Spain)

    2009-07-15

    A transient 3-D mathematical model for solar flat plate collectors has been developed. The model is based on setting mass and energy balances on finite volumes. The model allows the comparison of different configurations: parallel tubes collectors (PTC), serpentine tube collectors (STC), two parallel plate collectors (TPPC), and other non-usual possibilities like the use of absorbent fluids with semitransparent or transparent plates. Transparent honeycomb insulation between plate and cover can also be modelled. The effect of temperature on the thermal properties of the materials has also been considered. The model has been validated experimentally with a commercial PTC. The model is a useful tool to improve the design of plate solar collectors and to compare different configurations. In order to show the capabilities of the model, the performance of a PTC collector with non-uniformity flow is analysed and compared with experimental data from literature with good agreement. (author)

  15. Large-scale solar thermal collector concepts

    Science.gov (United States)

    Brantley, L. W., Jr.

    1975-01-01

    Thermal collector could be used ultimately to power steamplant to produce electricity. Collector would consist of two major subsystems: (1) series of segmented tracking mirrors with two axes of rotation and (2) absorber mounted on centrally located tower.

  16. 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.

  17. 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.

  18. Experimental and numerical investigation of a flat-plate solar collector

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, A. [Departamento de Construcciones Navales, E.U. Politecnica, Universidade da Coruna, 15405 Ferrol (Spain); Cabeza, O. [Departamento de Fisica, Universidade da Coruna, 15072 A Coruna (Spain); Muniz, M.C. [Departamento de Matematica Aplicada, Universidade de Santiago de Compostela, 15782 Santiago de Compostela (Spain); Varela, L.M. [Departamento de Fisica de la Materia Condensada, Universidade de Santiago de Compostela, 15782 Santiago de Compostela (Spain)

    2010-09-15

    In the present paper we present an experimental analysis and a thermal and hydrodynamic modelling of a newly designed flat-plate solar collector characterized by its corrugated channel and by the high surface area directly in contact with the heat transport fluid. The thermal and hydrodynamic modelling of the collector has been performed by means of the Finite Element Method (FEM), validated with analytical results for a well-known fin-and-tube type solar collector. The thermodynamic efficiency of the collector is analyzed by means of its experimental heating curves. The yield of the new collector has been compared to a previously existing commercial collector of related geometry but with less area in direct contact with the heat transport fluid. The experimental results are seen to adequately fit the simulation predictions, and a methodology to use in order to compute the parameters characterizing the thermal behavior of the collector is introduced. (author)

  19. Thermal performance evaluation of the Semco (liquid) solar collector

    Science.gov (United States)

    1979-01-01

    Procedures used and results obtained during the evaluation test program on a flat plate collector which uses water as the working fluid are discussed. The absorber plate is copper tube soldered to copper fin coated with flat black paint. The glazing consists of two plates of Lo-Iron glass; the insulation is polyurethane foam. The collector weight is 242.5 pounds with overall external dimensions of approximately 48.8 in. x 120.8 in. x 4.1 in. The test program was conducted to obtain thermal performance data before and after 34 days of weather exposure test.

  20. REVIEW OF PERFORMANCE AND ANALYSIS ISI FLAT PLATE COLLECTOR WITH MODIFIED FLAT PLATE COLLECTOR

    Directory of Open Access Journals (Sweden)

    MR.Y.Y.NANDURKAR

    2012-03-01

    Full Text Available The market of solar water heater of natural circulation type (thermo-siphon is fast growing in India. Initial cost of the solar water heater system at present is high because of store type design. It is necessary to make the product more popular by reducing the cost. This is possible by reducing area of liquid flat plate collector by increasing tube diameter and reducing riser length. Hence it is essential to make solar water heater in affordable range of the general public class. Present work is based on review of comparative performance and analysis of ISI flat plate collector with modified flat plat collector. The paper will be helpful for those who are working in the area of solar water heating system and their use in domestic areas.

  1. Combined photovoltaic and thermal hybrid collector systems

    Energy Technology Data Exchange (ETDEWEB)

    Kern, E.C. Jr.; Russell, M.C.

    1978-01-01

    Solar energy collectors that produce both electric and thermal energy are an attractive alternative to individual thermal and photovoltaic collectors for certain applications and climates. Economic results from a system analysis indicate that hybrid collector systems are attractive in small buildings that have substantial heating loads. Passively cooled photovoltaic panels are best suited for structures located in regions where year-round air conditioning and small, low-grade, thermal energy demands predominate. Hybrid collectors are to be tested according to ASHRAE standards and a full-system experiment incorporating a photovoltaic array installed at the Solar Energy Research Facility of the University of Texas will be conducted by Lincoln Laboratory.

  2. Comparison of Electrical and Thermal Performances of Glazed and Unglazed PVT Collectors

    Directory of Open Access Journals (Sweden)

    Jin-Hee Kim

    2012-01-01

    Full Text Available Photovoltaic-thermal (PVT collectors combine photovoltaic modules and solar thermal collectors, forming a single device that receives solar radiation and produces electricity and heat simultaneously. PVT collectors can produce more energy per unit surface area than side-by-side PV modules and solar thermal collectors. There are two types of liquid-type flat-plate PVT collectors, depending on the existence of glass cover over PV module: glass-covered (glazed PVT collectors, which produce relatively more thermal energy but have lower electrical yield, and uncovered (unglazed PVT collectors, which have relatively lower thermal energy with somewhat higher electrical performance. In this paper, the experimental performance of two types of liquid-type PVT collectors, glazed and unglazed, was analyzed. The electrical and thermal performances of the PVT collectors were measured in outdoor conditions, and the results were compared. The results show that the thermal efficiency of the glazed PVT collector is higher than that of the unglazed PVT collector, but the unglazed collector had higher electrical efficiency than the glazed collector. The overall energy performance of the collectors was compared by combining the values of the average thermal and electrical efficiency.

  3. Solar thermal collectors using planar reflector

    Science.gov (United States)

    Espy, P. N.

    1978-01-01

    Specular reflectors have been used successfully with flat-plate collectors to achieve exceptionally high operating temperatures and high delivered energy per unit collector area. Optimal orientation of collectors and reflectors can result in even higher performance with an improved relationship between energy demand and supply. This paper reports on a study providing first order optimization of collector-reflector arrays in which single- and multiple-faceted reflectors in fixed or singly adjustable configurations provide delivered energy maxima in either summer or winter.

  4. 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...

  5. 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...

  6. Therminol VP-1导热油平板太阳能集热器的热工性能测试实验%Therminol VP-1 Heat Transfer Fluid Plate Solar Collector Thermal Performance Test

    Institute of Scientific and Technical Information of China (English)

    唐千喻; 王华; 王辉涛; 卿山

    2011-01-01

    Due to the advantages and disadvantages ofstructure of solar collectors, developed a new type of heat transfer fluid plate solar collectors, and test its performance. Measured results, it can achieve the thermal efficiency of 0.45, higher than the conventional flat solar collector Shows that the heat transfer fluid superior performance, have a good prospect.%针对市场上的平板太阳能集热器结构的优缺点,研制了新型的导热油平板太阳能集热器,并测试其性能.实测结果为,热效率能达到0.45,比普通平板集热器高.表明该导热油平板太阳能集热器性能优越,有很好的应用前景.

  7. A graphical approach to the efficiency of flat-plate collectors

    Science.gov (United States)

    Selcuk, M. K.

    1978-01-01

    A nomogram is described which can be used to determine the thermal performance of flat plate solar collectors, resulting in two performance factors: the net absorptance and the net heat loss coefficient. The nomogram takes into account angle of incidence, collector slope, absorber plate design, insulating materials, thicknesses, optical properties of absorbing surfaces and glazing materials, and flow factors. A case example is given to illustrate the use of the nomogram.

  8. Performance Study of a Double-Pass Thermoelectric Solar Air Collector with Flat-Plate Reflectors

    Science.gov (United States)

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

    2012-06-01

    In this paper the results of the influence of flat-plate reflectors made of aluminum foil on the performance of a double-pass thermoelectric (TE) solar air collector are presented. The proposed TE solar collector with reflectors was composed of transparent glass, an air gap, an absorber plate, TE modules, a rectangular fin heat sink, and two flat-plate reflectors. The flat-plate reflectors were placed on two sides of the TE solar collector (east and west directions). The TE solar collector was installed on a one-axis sun-tracking system to obtain high solar radiation. Direct and reflected incident solar radiation heats up the absorber plate so that a temperature difference is created across the TE modules to generate a direct current. Only a small part of the absorbed solar radiation is converted to electricity, while the rest increases the temperature of the absorber plate. Ambient air flows through the heat sink located in the lower channel to gain heat. The heated air then flows to the upper channel, where it receives additional heating from the absorber plate. Improvements to the thermal energy and electrical power outputs of the system can be achieved by the use of the double-pass collector system with reflectors and TE technology. It was found that the optimum position of the reflectors is 60°, which gave significantly higher thermal energy and electrical power outputs compared with the TE solar collector without reflectors.

  9. Thermal performance of integration of solar collectors and building envelopes

    Institute of Scientific and Technical Information of China (English)

    于国清; 龚小辉; 曹双华

    2009-01-01

    The integration of building with solar collector was studied. The theoretical model of integration of building envelopes and flat plate solar collectors was set up and the thermal performance of integration was studied in winter and summer,and compared to envelopes without solar collectors. The results show that the solar collection efficiency is raised in the integration of building envelopes and solar collectors with the air layer doors closed. This is true whether in winter or summer. The increment is higher as the inlet water temperature increases or the ambient temperature is low. In winter,the heat loss is significantly reduced through integration of the building envelopes and solar collectors with the closed air layer doors. The integration with the open air layer door is worse than that without collectors. In summer,the heat gains of the integration of envelopes and solar collectors are more obviously reduced than envelopes without collectors,the integration with the open air layer door is a little better than the closed one,but the difference is very small.

  10. Performance of a solar-thermal collector

    Science.gov (United States)

    Higa, W. H.

    1975-01-01

    Possible means of achieving the technology required for field application of solar thermal power systems are discussed. Simplifications in construction techniques as well as in measurement techniques for parabolic trough collectors are described. Actual measurement data is also given.

  11. Design and Development of ZigBee Based Instantaneous Flat-plate Collector Efficiency Measurement System

    Science.gov (United States)

    Vairamani, K.; Venkatesh, K. Arun; Mathivanan, N.

    2011-01-01

    Computing the efficiency of flat-plate collector is vital in solar thermal system testing. This paper presents the design of ZigBee enabled data acquisition system for instantaneous flat-plate collector efficiency calculation. It involves measurement of parameters like inlet and outlet fluid temperatures, ambient temperature and solar radiation intensity. The designed system has a base station and a sensor node. ZigBee wireless communication protocol is used for communication between the base station and the sensor node for wireless data acquisition. The wireless sensor node which is mounted over the collector plate includes the necessary sensors and associated signal-conditioners. An application program has been developed on LabVIEW platform for data acquisition, processing and analysis and is executed in base station PC. Instantaneous flat-plate collector efficiency is computed and reported.

  12. A dynamic simulation of a flat-plate collector system

    Science.gov (United States)

    Annino, A.

    1983-04-01

    A numerical model for the performance of a flat plate solar collector array is presented, with account taken of thermal transients and calculation on a microcomputer. The system modeled consists of a flat plate array, the heat transfer fluid, an insulated storage tank, an exchange loop for heating a secondary fluid, and a load maintained by a pump. The one-dimensional analysis includes equations for the energy balances, with consideration given to heat losses to the outside. A function is defined for the total incident solar radiation, and behavior is simulated over the entire 24-hr day, weighted by the highest and lowest recorded temperatures. Good agreement has been found with experimental data.

  13. Experimental study on flat plate air solar collector using a thin sand layer

    Science.gov (United States)

    Lati, Moukhtar; Boughali, Slimane; Bouguettaia, Hamza; Mennouche, Djamel; Bechki, Djamel

    2016-07-01

    A flat plate air solar collector was constructed in the laboratory of New and Renewable Energy in Arid Zones LENREZA, Ouargla University-South East Algeria. The absorber of the flat plate air solar collector was laminated with a thin layer of local sand. This acted as a thermal storage system (packed bed) with a collecting area of 2.15 m2 (0.86 m × 2.5 m). It was noticed that the solar heater integrated with the thermal storage material delivered comparatively higher temperatures; thus, giving a better efficiency than the air heater without the thermal storage system.

  14. Thermal performance evaluation of the Calmac (liquid) solar collector

    Science.gov (United States)

    Usher, H.

    1978-01-01

    The procedures used and the results obtained during the evaluation test program on the S. N. 1, (liquid) solar collector are presented. The flat plate collector uses water as the working fluid. The absorber plate is aluminum with plastic tubes coated with urethane black. The glazing consists of .040 in fiberglass reinforced polyester. The collector weight is 78.5 pounds with overall external dimensions of approximately 50.3in. x 98.3in. x 3.8in. The following information is given: thermal performance data under simulated conditions, structural behavior under static loading, and the effects of long term exposure to natural weathering. These tests were conducted using the MSFC Solar Simulator.

  15. Heat transfer and energy analysis of a solar air collector with smooth plate

    Science.gov (United States)

    Chabane, Foued; Moummi, Noureddine

    2014-04-01

    The heat transfer and thermal performance of a single pass solar air heater a smooth plate was investigated experimentally. In the present paper, energy and heat transfer analysis of a solar air collector with smooth plate, this technique is used to determine the optimal thermal performance of flat plate solar air heater by considering the different system and operating parameters to obtain maximum thermal performance. Thermal performance is obtained for different mass flow rate varying in the array 0.0108-0.0202 kg/s with five values, solar intensity; tilt angle and ambient temperature. We discuss the thermal behavior of this type of collector with new design and with my proper construction. An experimental study was carried out on a prototype installed on the experimental tests platform within the University of Biskra in the Algeria. The effects of air mass flow rate, emissivity of channel plates and wind heat transfer coefficient on the accuracy of the criterion are also investigated.

  16. Development of high efficiency collector plates. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Santala, T.; Sabol, R.

    1976-02-01

    Composite metal technology was used to manufacture intermetallic compound (IC) absorption surfaces and to combine them integrally with composite metal tube-in-sheet collector plates. Five material systems in which Al was one component metal and Fe, Cr, or Ni and their alloy was the other pair, were evaluated. All intermetallic compounds had high solar absorptance ..cap alpha.. approx. = 0.9. The AlNi was most promising and ..cap alpha.. > or = 0.95 and epsilon approx. = 0.3 were obtained over a broad range of compounding conditions. After eight months exposure in a flat plate collector enclosure the characteristic properties of AlNi surfaces remained virtually unchanged. Only LCS/Cu composite metal tube-in-sheet collector plates could be manufactured successfully. The technical difficulties associated with integrating the intermetallic compound and tube-in-sheet technologies make the manufacturing of composite metal collector plates at the time being economically unfeasible.

  17. Comparison under a simulated sun of two black-nickel-coated flat-plate solar collectors with a nonselective black-paint-coated collector

    Science.gov (United States)

    Simon, F. F.

    1975-01-01

    A performance evaluation was made of two, black nickel coated, flat plate solar collectors. Collector performance was determined under a simulated sun for a wide range of inlet temperatures, including the temperature required for solar powered absorption air conditioning. For a basis of comparison a performance test was made on a traditional, two glass, nonselective, black paint coated, flat plate collector. Performance curves and performance parameters are presented to point out the importance of the design variables which determine an efficient collector. A black nickel coated collector was found to be a good performer at the conditions expected for solar powered absorption air conditioning. This collector attained a thermal efficiency of 50 percent at an inlet temperature of 366 K (200 F) and an incident flux of 946 watts/sq m (300 Btu/hr-sq ft).

  18. Improvement of flat plate collectors for solar energy conversion

    Science.gov (United States)

    Boeck, H.; Hallermayer, R.; Schoelkopf, W.; Sizman, R.

    1984-03-01

    Selective absorption for thermal conversion of radiative energy was investigated. Improvement and operation of various measuring devices for absorption and emission are presented. Selective coatings were produced by vapor deposition and galvanic treatment. Calculations of the transmittance of turbular collector fields are presented. Operational Characteristics of Collector were examined. A collector test field with simultaneous recording of data from 24 collectors or uncovered absorbers was built and connected to a high performance microprocessor system. The transient behavior of collectors by variation of the irradiation and the collector inlet temperature were investigated. A mechanism for stratification of hot water of fluctuating inlet temperature in a storage tank was studied. The operating conditions of a heat pump installed in the collector test plant are investigated. A large domestic hot water system is equipped with temperature sensors and flowmeters for computer recording.

  19. Detailed Modeling of Flat Plate Solar Collector with Vacuum Glazing

    Directory of Open Access Journals (Sweden)

    Viacheslav Shemelin

    2017-01-01

    Full Text Available A theoretical analysis of flat plate solar collectors with a vacuum glazing is presented. Different configurations of the collector have been investigated by a detailed theoretical model based on a combined external and internal energy balance of the absorber. Performance characteristics for vacuum flat plate collector alternatives have been derived. Subsequently, annual energy gains have been evaluated for a selected variant and compared with state-of-the-art vacuum tube collectors. The results of modeling indicate that, in the case of using advanced vacuum glazing with optimized low-emissivity coating (emissivity 0.20, solar transmittance 0.85, it is possible to achieve efficiency parameters similar to or even better than vacuum tube collectors. The design presented in this paper can be considered promising for the extension of the applicability range of FPC and could be used in applications, which require low-to-medium temperature level.

  20. Flat-plate solar-collector performance data base and user's manual

    Science.gov (United States)

    Kirkpatrick, D. L.; Kolar, W. A.

    1983-07-01

    The reader is provided with a thorough understanding on the type of collector thermal performance information which is required in active system design and analysis. Thermal performance test data on 109 commercially available solar collectors which were evaluated in a single, uniform test program, the Interim Solar Collector Test (ISCT) Program are given. In addition to recounting the ISCT program and its results, the an introduction is given on the engineering and physics of a flat-plate solar collector operation. A step-by-step analysis of heat gains and losses is provided to help the reader understand both the source and applicability of the parameters used to describe collector thermal performance. A brief description of the engineering basis for the ASHRAE Standard 93-77 test procedure and the method are included. To demonstrate the sensitivity to variations of collector performance parameters of the annual output of representative solar heating systems, three sets of F-Chart (4.0) system performance predictions are given. Finally, a sensitivity analysis study is presented which considers the heat loss and optical gain parameters of flat-plate collectors, in terms of how they affect the overall solar heating system solar fraction.

  1. Natural convection characteristics of flat plate collectors. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Randall, K.R.; Wl-Wakil, M.M.; Mitchell, J.W.

    1977-09-01

    The results of an experimental investigation into the convective heat losses in large aspect ratio flat-plate solar collectors are described. An experimental study has been undertaken on a specially designed test cell using a 3 inch Mach-Zehnder interferometer. Air at atmospheric pressure was used as the heat-transfer fluid. The experimental results include interferograms which show the thermal boundary layer formations and the temperature profiles. Local temperature profiles have been analyzed through the use of an optical comparator to determine local Nusselt number profiles, which have, in turn, been integrated to give average heat-transfer results. Angles of inclination from the horizontal of 45, 60, 75 and 90 degrees have been investigated. Aspect ratios from 9 to 36 were examined over a Rayleigh number range of 4,000 to 310,000. Finally, heat-transfer correlations have been developed for the prediction of local Nusselt numbers in the starting and departure corners and for the average heat-transfer results as a function of collector tilt angle.

  2. Standardized solar simulator tests of flat plate solar collectors. 1: Soltex collector with two transparent covers

    Science.gov (United States)

    Simon, F.

    1975-01-01

    A Soltex flat plate solar collector was tested with a solar simulator for inlet temperatures of 77 to 201 F, flux levels of 240 and 350 Btu/hr-sq ft, a collant flow rate of 10.5 lb/hr sq ft, and incident angles of 0 deg, 41.5 deg, and 65.2 deg. Collector performance is correlated in terms of inlet temperature, flux level, and incident angle.

  3. Low cost bare-plate solar air collector

    Energy Technology Data Exchange (ETDEWEB)

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

    1980-09-01

    The purpose of this project was to develop a low cost, bare-plate collector, determine its performance for a variety of climatic conditions, analyze the economics of this type of solar collector and evaluate specific applications. 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% or greater with air preheat temperature uses up to 20/sup 0/F for one of the prototypes. The economic analyses indicated that an installed cost of between $5 and $10 per square foot would make this type of solar system economically viable. For the materials of construction and the type of fabrication and installation perceived, these costs for the bare-plate solar collector are believed to be attainable. Specific applications for preheating ventilation air for schools were evaluated and judged to be economically viable.

  4. Calculating the Solar Energy of a Flat Plate Collector

    Directory of Open Access Journals (Sweden)

    Ariane Rosario

    2014-09-01

    Full Text Available The amount of solar energy that could be obtained by a flat plate solar collector of one square meter dimension is calculated in three different locations: Tampa FL, Fairbanks AL, and Pontianak Indonesia, considering the varying sunset time for each day of the year. The results show that if the collectors are placed near the equator, more total energy could be obtained. In fact, by placing a solar collector in Pontianak, Indonesia 12.42% more solar energy can be obtained than by placing it in Tampa and 96.9% more solar energy than Alaska.

  5. 平板太阳能集热器热性能数学建模及模拟%Mathematical Modeling and Simulation of Thermal Properties of Flat-Plate Solar Collector

    Institute of Scientific and Technical Information of China (English)

    卢郁; 于洪文; 丁海成; 张艳丽; 刘宗明

    2013-01-01

    以平板太阳能集热器作为研究对象,通过对平板太阳能集热器热性能进行理论推导,引入效率因子,构建更为准确、便捷的平板集热器的数学模型,进行计算机程序模拟.根据模拟数据得出吸热体板芯几何结构、板芯用材对平板太阳能集热器性能的影响.在不降低集热器效率因子的情况下,使翅片的单位面积质量降低45.8%;在材料消耗相同的情况下,集热器效率因子提高了0.03.%Taking a flat-plate solar collector as research object and introducing an efficiency factor, we establish a mathematical model for the collector after theoretically deriving out the thermal properties of it, and numerically simulate it according to this model. Simulation results show that the mass per unit area of the collector drops 45. 8% with the same efficiency factor and the efficiency factor increasesby 0.03 with the same material consumption.

  6. Flat plate solar collector design and performance. (Latest citations from the NTIS bibliographic database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    The bibliography contains citations concerning the design and thermal efficiency of air and liquid type flat plate solar collectors. Topics include convection characteristics, methods to reduce heat loss, optical coatings, and corrosion prevention. Emphasis is on research and modeling. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  7. Flat plate solar collector design and performance. (Latest citations from the NTIS bibliographic database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-05-01

    The bibliography contains citations concerning the design and thermal efficiency of air and liquid type flat plate solar collectors. Topics include convection characteristics, methods to reduce heat loss, optical coatings, and corrosion prevention. Emphasis is on research and modeling. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  8. Flat plate solar collector design and performance. Citations from the NTIS data base

    Science.gov (United States)

    Hundemann, A. S.

    1980-09-01

    Federally funded research on the design and thermal efficiency of air and liquid type flat plate collectors is discussed. Topic areas cover convection characteristics, methods to reduce heat loss, optical coatings, and corrosion control. Emphasis of the bibliography is on basic research studies. This updated bibliography contains 196 citations, 36 of which are new entries to the previous edition.

  9. Hot-air flat-plate solar collector-design package

    Science.gov (United States)

    1979-01-01

    Report contains design data, performance specifications, and drawings for hot-air flat-plate solar-energy collector. Evaluation consists of tests on thermal performance time constance, and incidence angle modifier test. Results are presented in table and graph form and are analyzed in detail.

  10. Hot-air flat-plate solar collector-design package

    Science.gov (United States)

    1979-01-01

    Report contains design data, performance specifications, and drawings for hot-air flat-plate solar-energy collector. Evaluation consists of tests on thermal performance time constance, and incidence angle modifier test. Results are presented in table and graph form and are analyzed in detail.

  11. Thermal performance evaluation of Solar Energy Products Company (SEPCO) 'Soloron' collector tested outdoors

    Science.gov (United States)

    Chiou, J., Sr.

    1977-01-01

    The test article, Model EF-212, Serial Nr. 002, is a single glazed collector with a nonselective absorber plate, using flowing air as the heat transfer medium. The absorber plate and box frame are aluminum and the insulation is one inch isocyanurate foam board with thermal conductivity of 0.11 (BTU/sq ft Hr0/ft.) The tests included the following. (1) time constant test, (2) collector efficiency test, (3) collector stagnation test, (4) incident angle modifier test, (5) load test, (6) weathering test, and (7) absorber plate optical properties test. The results of these tests are tabulated, graphed, or otherwise recorded.

  12. 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...

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

    DEFF Research Database (Denmark)

    Andersen, Elsa; Dragsted, Janne; Furbo, Simon

    2010-01-01

    . 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......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...

  14. Coupled thermal fluid modelling of a low embedded energy solar thermal collector

    Energy Technology Data Exchange (ETDEWEB)

    Corcoran, M.; Gibbons, C. [Cork Institute of Technology (Ireland). Energy Engineering Group

    2004-07-01

    A mathematical model was developed for a forced convection solar hot water system. The solar collector in this study incorporates a honeycombed extruded polycarbonate structure, for both the cover and water channels. The initial section of the program predicts solar radiation (hourly, monthly and yearly) as an input section to the solar collector calculations. As well as determining the collector performance, the model also facilitates changes to the collector physical properties such as dimensions of the channels, selective and non-selective absorbers, material thermal properties, as well as ambient temperature and flow rate, in order to optimise the system design. The results from the program will allow a full parametric study of different collector design criteria, with this polycarbonate structure. The results will be compared to a standard flat plate collector design, to see if this polycarbonate flat plate collector is a more effective design. ISO 9806-2 standards are being used to validate the results, for the parametric study in the lab, under steady state conditions. The final optimum design will then be tested outdoors using the quasi-dynamic conditions set out by the European Standard EN 12975-2. Weather data, obtained from the weather station set up at CIT, will be used as the input for the weather conditions for out door testing. (orig.)

  15. Validation of CFD simulation for flat plate solar energy collector

    Energy Technology Data Exchange (ETDEWEB)

    Selmi, Mohamed; Al-Khawaja, Mohammed J.; Marafia, Abdulhamid [Department of Mechanical Engineering, University of Qatar, P.O. Box 2713, Doha, State of Qatar (Qatar)

    2008-03-15

    The problem of flat plate solar energy collector with water flow is simulated and analyzed using computational fluid dynamics (CFD) software. The considered case includes the CFD modeling of solar irradiation and the modes of mixed convection and radiation heat transfer between tube surface, glass cover, side walls, and insulating base of the collector as well as the mixed convective heat transfer in the circulating water inside the tube and conduction between the base and tube material. The collector performance, after obtaining 3-D temperature distribution over the volume of the body of the collector, was studied with and without circulating water flow. An experimental model was built and experiments were performed to validate the CFD model. The outlet temperature of water is compared with experimental results and there is a good agreement. (author)

  16. 平板式热管太阳能空气集热器热性能研究%Experimental Investigation on Thermal Performance of Flat Plate Heat Pipe Solar Air Collector

    Institute of Scientific and Technical Information of China (English)

    李世平; 向开根; 李雯; 罗会龙; 王霜

    2015-01-01

    Heat pipe has many advantages, such as higher heat transfer coefficient, lower transfer temperature-difference and a one-way heat transfer. A new flat plate heat pipe solar air collector was designed and built based on a reasonable construction. The test results indicated that the instantaneous efficiency of collector is 15.3%~74.5% under the climatic conditions of daily solar radiation being about 14.4 to19.8MJ/m2·day. Its daily average thermal efficiency is about 32.6%~53.5%with heat loss coefficient being 3.6~8.4W/(m2·K). The maximum outlet air temperature can reach 79.1℃. Compared with conventional air collectors, the new flat plate heat pipe solar air collector has higher thermal efficiency and outlet air.%热管具有传热系数高、传热温差小及单向传热等诸多优良特性。以热管为集热部件,试制了一种平板式热管太阳能空气集热器。测试结果表明,在日总太阳辐射为14.4MJ/m2~19.8MJ/m2的气候条件下,平板式热管太阳能空气集热器的瞬时集热效率在15.3%~74.5%之间,集热器出口空气温度可达79.1℃,其日平均集热效率约为32.6%~53.5%,其热损失系数约为3.6~8.4W/(m2·K)。与常规的太阳能空气集热器相比,平板式热管太阳能空气集热器具有较高的集热效率和较低的热损失系数,并且供热温度较高。

  17. Potential of size reduction of flat-plate solar collectors when applying MWCNT nanofluid

    Science.gov (United States)

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

    2013-06-01

    Flat-plate solar collector is the most popular type of collector for hot water system to replace gas or electric heater. Solar thermal energy source is clean and infinite to replace fossil fuel source that is declining and harmful to the environment. However, current solar technology is still expensive, low in efficiency and takes up a lot of space. One effective way to increase the efficiency is by applying high conductivity fluid as nanofluid. This paper analyzes the potential of size reduction of solar collector when MWCNT nanofluid is used as absorbing medium. The analysis is based on different mass flow rate, nanoparticles mass fraction, and presence of surfactant in the fluid. For the same output temperature, it can be observed that the collector's size can be reduced up to 37% of its original size when applying MWCNT nanofluid as the working fluid and thus can reduce the overall cost of the system.

  18. Certification and verification for calmac flat plate solar collector

    Energy Technology Data Exchange (ETDEWEB)

    1978-01-27

    This document contains information used in the certification and verification of the Calmac Flat Plate Collector. Contained are such items as test procedures and results, information on materials used, Installation, Operation, and Maintenance Manuals, and other information pertaining to the verification and certification.

  19. Thermal performance evaluation of the Solargenics solar collector at outdoor conditions

    Science.gov (United States)

    1978-01-01

    Test procedures used during the performance of an evaluation program are presented. The test program was conducted to obtain the following performance data and information on the solar collector. (1) thermal performance data under outdoor conditions; (2) structural behavior of collector under static conditions; (3) effects of long term exposure to material weathering elements. The solargenics is a liquid, single-glazed, flat plate collector. Approximate dimensions of each collector are 240 inches long, 36 inches wide, and 3.5 inches in depth.

  20. Analysis of PV/T flat plate water collectors connected in series

    Energy Technology Data Exchange (ETDEWEB)

    Dubey, Swapnil; Tiwari, G.N. [Centre for Energy Studies, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016 (India)

    2009-09-15

    Photovoltaic-thermal (PV/T) technology refers to the integration of a PV and a conventional solar thermal collector in a single piece of equipment. In this paper we evaluate the performance of partially covered flat plate water collectors connected in series using theoretical modeling. PV is used to run the DC motor, which circulates the water in a forced mode. Analytical expressions for N collectors connected in series are derived by using basic energy balance equations and computer based thermal models. This paper shows the detailed analysis of thermal energy, exergy and electrical energy yield by varying the number of collectors by considering four weather conditions (a, b, c and d type) for five different cities (New Delhi, Bangalore, Mumbai, Srinagar, and Jodhpur) of India. Annual thermal and electrical energy yield is also evaluated for four different series and parallel combination of collectors for comparison purpose considering New Delhi conditions. This paper also gives the total carbon credit earned by the hybrid PV/T water heater investigated as per norms of Kyoto Protocol for New Delhi climatic conditions. Cost analysis has also been carried out. It is observed that the collectors partially covered by PV module combines the production of hot water and electricity generation and it is beneficial for the users whose primary requirement is hot water production and collectors fully covered by PV is beneficial for the users whose primary requirement is electricity generation. We have also found that if this type of system is installed only in 10% of the total residential houses in Delhi then the total carbon credit earned by PV/T water heaters in terms of thermal energy is USD $144.5 millions per annum and in terms of exergy is USD $14.3 millions per annum, respectively. (author)

  1. An effective simulation model to predict and optimize the performance of single and double glaze flat-plate solar collector designs

    OpenAIRE

    Kaplanis, S.; Kaplani, E.

    2012-01-01

    This paper outlines and formulates a compact and effective simulation model, which predicts the performance of single and double glaze flat-plate collector. The model uses an elaborated iterative simulation algorithm and provides the collector top losses, the glass covers temperatures, the collector absorber temperature, the collector fluid outlet temperature, the system efficiency, and the thermal gain for any operational and environmental conditions. It is a numerical approach based on simu...

  2. Influence of wire-coil inserts on the thermo-hydraulic performance of a flat-plate solar collector

    Science.gov (United States)

    Herrero Martín, R.; García, A.; Pérez-García, J.

    2012-11-01

    Enhancement techniques can be applied to flat-plate liquid solar collectors towards more compact and efficient designs. For the typical operating mass flow rates in flat-plate solar collectors, the most suitable technique is inserted devices. Based on previous studies from the authors, wire coils were selected for enhancing heat transfer. This type of inserted device provides better results in laminar, transitional and low turbulence fluid flow regimes. To test the enhanced solar collector and compare with a standard one, an experimental side-by-side solar collector test bed was designed and constructed. The testing set up was fully designed following the requirements of EN12975-2 and allow us to accomplish performance tests under the same operating conditions (mass flow rate, inlet fluid temperature and weather conditions). This work presents the thermal efficiency curves of a commercial and an enhanced solar collector, for the standardized mass flow rate per unit of absorber area of 0.02 kg/sm2 (in useful engineering units 144 kg/h for water as working fluid and 2 m2 flat-plate solar collector of absorber area). The enhanced collector was modified inserting spiral wire coils of dimensionless pitch p/D = 1 and wire-diameter e/D = 0.0717. The friction factor per tube has been computed from the overall pressure drop tests across the solar collectors. The thermal efficiency curves of both solar collectors, a standard and an enhanced collector, are presented. The enhanced solar collector increases the thermal efficiency by 15%. To account for the overall enhancement a modified performance evaluation criterion (R3m) is proposed. The maximum value encountered reaches 1.105 which represents an increase in useful power of 10.5% for the same pumping power consumption.

  3. Operational demonstration of a field of high performance flat plate collectors with isothermal heat transport

    Science.gov (United States)

    Merges, V.; Klippel, E.

    1983-12-01

    A solar plant with 21 sq m of highly efficient flat plate collectors and which requires no electricity is described. Heat transport is provided by saturated steam that condenses in a four cubic meter storage tank. The operation temperature is set by the buffer gas pressure between 100 and 140 C, and an absorption chiller is simulated as a heat consumer. The solar collectors were observed to exhibit high performance. Heat transport and temperature control offered high reliability and the thermal stratification in the tank was satisfactory. The positive result permits the design and construction of larger solar plants following the same technical principles.

  4. Thermal performance of honeywell double covered liquid solar collector

    Science.gov (United States)

    Losey, R.

    1977-01-01

    The test procedures and results obtained during an evaluation test program to determine the outdoor performance characteristics of the Honeywell liquid solar collector are presented. The program was based on the thermal evaluation of a Honeywell double covered liquid solar collection. Initial plans included the simultaneous testing of a single covered Honeywell collector. During the initial testing, the single covered collector failed due to leakage; thus, testing continued on the double covered collector only. To better define the operating characteristics of the collector, several additional data points were obtained beyond those requested.

  5. Thermal performance of a hot-air solar collector

    Science.gov (United States)

    1978-01-01

    Report contains procedures and results of thermal-performance tests on double-glazed air solar collector. Four types of tests were carried out including thermal-efficiency and stagnation tests, collector time-constant tests to assess effects of transients, and incident-angle modifier tests. Data are presented in tables and as graphs and are discussed and analyzed.

  6. Standard Practice for Generating All-Day Thermal Performance Data for Solar Collectors

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1987-01-01

    1.1 This practice covers a means of generating all-day thermal performance data for flat-plate collectors, concentrating collectors, and tracking collectors. 1.2 The values stated in SI units are to be regarded as the standard. The values given in the parentheses are for information only. 1.3 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.

  7. Performance test procedures for thermal collectors - Outdoor testing

    Science.gov (United States)

    Gillett, W. B.

    A review of outdoor solar collector test methods is presented, based largely on the CEC Recommendations for European Solar Collector Test Methods. Test facility design and instrumentation are discussed, with reference to their influence on measured collector efficiencies. Steady state outdoor testing, mixed indoor/outdoor testing and transient testing are reviewed, and it is concluded that although the testing of simple flat plate water heaters is fairly well understood, more work is now required to develop test methods for the new high performance collectors which are coming onto the market.

  8. Thermal Performance of an Annealed Pyrolytic Graphite Solar Collector

    Science.gov (United States)

    Jaworske, Donald A.; Hornacek, Jennifer

    2002-01-01

    A solar collector having the combined properties of high solar absorptance, low infrared emittance, and high thermal conductivity is needed for applications where solar energy is to be absorbed and transported for use in minisatellites. Such a solar collector may be used with a low temperature differential heat engine to provide power or with a thermal bus for thermal switching applications. One concept being considered for the solar collector is an Al2O3 cermet coating applied to a thermal conductivity enhanced polished aluminum substrate. The cermet coating provides high solar absorptance and the polished aluminum provides low infrared emittance. Annealed pyrolytic graphite embedded in the aluminum substrate provides enhanced thermal conductivity. The as-measured thermal performance of an annealed pyrolytic graphite thermal conductivity enhanced polished aluminum solar collector, coated with a cermet coating, will be presented.

  9. Indoor test for thermal performance evaluation of seven Elcam fin-tube solar collector configurations

    Science.gov (United States)

    1979-01-01

    The test procedure used and the results obtained from an evaluation test program conducted to obtain thermal performance data on seven Elcam fin-tube solar collector configurations under simulated conditions are described. These tests were made using the Marshall Space Flight Center solar facilities. The Elcam fin-tube (liquid) solar collectors each consist of an absorber plate 5.9 inches wide by 83 inches long and a type M copper tube of 0.569 inch nominal inside diameter. No cover plate was used with any of the specimens. The uniqueness of each of the seven configurations is described, and tests were performed on each separate configuration.

  10. A dynamic performance simulation model of flat-plate solar collectors for a heat pump system

    Energy Technology Data Exchange (ETDEWEB)

    Arinze, E.A.; Schoenau, G.J.; Sokhansanj, S. (Saskatchewan Univ., Saskatoon, SK (Canada). College of Engineering); Adefila, S.S.; Mumah, S.M. (Ahmadu Bello Univ., Zaria (Nigeria). Dept. of Chemical Engineering)

    1993-01-01

    Flat-plate collectors are inherently exposed to time-varying meteorological and system parameters. Thus, dynamic modeling, rather than the commonly used steady-state models, is a more accurate approach for the design and performance evaluation of flat-plate solar collectors. The dynamic model presented in this study describes the fluid, plate and cover temperatures of the collector by three different differential equations. Taylor series expansion and the Runge-Kutta method are used in the solution of the differential equations. The accuracy of the dynamic model was tested by comparing the results predicted by the model with experimental performance data obtained for a liquid-cooled flat-plate solar collector with a corrugated transparent fiberglass cover. The predicted results by the dynamic model agreed favorably with the measured experimental data for the flat-plate solar collector. Experimentally determined collector temperatures varied by a maximum of [+-]3[sup o]C from values predicted by the model. (Author)

  11. 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.

  12. 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.

  13. 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.

  14. Indoor test for thermal performance evaluation of Libbey-Owens-Ford solar collector. [using a solar simulator

    Science.gov (United States)

    Shih, K.

    1977-01-01

    The thermal performance of a flat plate solar collector that uses liquid as the heat transfer medium was investigated under simulated conditions. The test conditions and thermal performance data obtained during the tests are presented in tabular form, as well as in graphs. Data obtained from a time constant test and incident angle modifier test, conducted to determine transient effect and the incident angle effect on the collector, are included.

  15. Indoor test for thermal performance evaluation of the Solaron (air) solar collector

    Science.gov (United States)

    1978-01-01

    The test procedure used and the results obtained from an evaluation test program, conducted to obtain thermal performance data on a Solaron double glazed air solar collector under simulated conditions in a solar simulator are described. A time constant test and incident angle modifier test were also conducted to determine the transient effect and the incident angle effect on the collector. These results and the results of the collector load test are also discussed. The Solaron collector absorber plate is made of 24-gage steel, the coating is baked-on black paint, the cover consists of two sheets of 1/8-inch low-iron tempered glass, and the insulation is one thickness of 3 5/8-inch fiberglass batting.

  16. Thermal performance evaluation of the Suncatcher SH-11 (liquid) solar collector

    Science.gov (United States)

    1980-01-01

    The procedures used and the results obtained during the evaluation test program on the Solar Unlimited, Inc., Suncatcher SH-11 (liquid) solar collector are presented. The flat-plate collector case assembly is made of .08 inch aluminum 3003 H14 riveted with fiberglass board insulation. The absorber consists of collared aluminum fins mechanically bonded to 3/8 inch copper tubing and coated with 3M Nextel black. Water is used as the working fluid. The glazing is made of a single glass, 1/8 inch water white, tempered and antireflective. The collector weight is 85 pounds with overall external dimensions of about 35.4 in x 82.0 in x 4.0 in. Thermal performance data on the Solar Unlimited Suncatcher SH-11 solar collector under simulated conditions were conducted using the MSFC Solar Simulator.

  17. Exergy efficiency analysis of a flat plate solar collector using graphene based nanofluid

    Science.gov (United States)

    Said, Z.; Alim, M. A.; Janajreh, Isam

    2015-10-01

    The thermal efficiency of a flat plate solar thermal collector is largely affected by the thermal conductivity of the fluid used. In this paper, we theoretically analyzed the heat transfer performance, the entropy generation rate, and the exergy efficiency of the two different graphene based nanofluids (graphene/Acetone and graphene/water). From the analyses, it is revealed that by inserting a small amount of graphene nanoparticles in water, exergy efficiency could be enhanced by 21%, comparing to conventional fluids and entropy generation is decreased by 4%. However, the graphene/water nanofluid shows a lower entropy generation. This characteristic suggests that graphene/water nanofluid is a better candidate for flat solar thermal application.

  18. Hybrid Photovoltaic Thermal (PV/T Air and Water Based Solar Collectors Suitable for Building Integrated Applications

    Directory of Open Access Journals (Sweden)

    Adnan Ibrahim

    2009-01-01

    Full Text Available Problem statement: Experiments have been conducted to investigate the effect of mass flow rates on the electrical, thermal and combined of photovoltaic thermal efficiencies of the hybrid collectors. Approach: Two photovoltaic thermal solar collectors were designed and fabricated. The first collector, known as spiral flow absorber collector, designed to generate hot water and electricity. The second collector, known as single pass rectangular tunnel absorber collector designed to generate hot air and electricity. Both absorber collectors were fixed underneath the flat plate single glazing sheet of polycrystalline silicon PV module. Water was used as a heat transfer medium in spiral flow absorber collector and air for the Single pass rectangular tunnel absorber collector respectively. Results: The experiment results showed that the single flow absorber collector generates combined PV/T efficiency of 64%, electrical efficiency of 11% and power maximum achieved at 25.35 W. Moreover, Single pass rectangular tunnel absorber collector generated combined PV/T efficiency of 55%, electrical efficiency of 10% and maximum power of 22.45 W. Conclusion/Recommendations: The best mass flow rate achieved for spiral flow absorber collector is 0.011 kg sec-1 at surface temperature of 55% and 0.0754 kg sec-1 at surface temperature of 39°C for single pass rectangular collector absorber. It was recommended for PV/T system to further improve its efficiency by optimizing the contact surfaces between the solar panel (photovoltaic module and the tubes underneath and also recommended to use other type of photovoltaic cell such as amorphous silicon cell that posses the black mat surfaces property that will improve it thermal absorption.

  19. Effects of Key Parameters on Thermal Performance of Solar Flat-Plate Collector%太阳能平板集热器关键参数对其热性能的影响

    Institute of Scientific and Technical Information of China (English)

    车永毅; 厚彩琴

    2016-01-01

    为了提升太阳能在建筑能源供给体系中的比重,形式多样的太阳能集热设备及其系统在建筑领域得到了广泛应用。基于机理分析法,建立了具有单层玻璃盖板的管板式太阳能平板集热器的稳态传热模型。并且针对集热管间距、集热管内径、工质入口温度和工质质量流量等关键参数对集热器集热效率的影响特性进行了数值模拟与分析。结果表明,建立的该稳态传热模型是可行的;此外,在其余参数值保持不变的情况下,减小集热管间距或增加集热管内径均可使集热器瞬时效率增大;增大工质入口温度会导致集热器瞬时效率下降;而增大工质质量流量会提升集热器瞬时效率。这些结论对于太阳能平板集热器在太阳能建筑一体化的实际应用中,具有一定的参考作用。%In order to improve the proportion of solar energy in building energy supply system, various forms of solar heat collection equipment and systems in the construction field has been widely used. Based on the mechanism analysis method, one steady-state heat transfer model of the single glass cover flat-plate collector is built. The numerical simulation and analysis of the effect of the key parameters including col-lector tube spacing, collector tube diameter, and inlet temperature and inlet mass flow rate of the working fluid on heat collection efficiency of the collector is carried out. The results show that the steady-state heat transfer model is feasible;and in the case of the same parameters, either reducing the collector tube spacing or increasing the collector tube diameter can increase the instantaneous efficiency of the collector; the instantaneous efficiency of the collector decline with the increase of inlet temperature of the working fluid. However, increasing the mass flow rate at the entrance can improve the instantaneous efficiency of the collector. These conclusions have a certain

  20. Evaluation of flat-plate collector efficiency under controlled conditions in a solar simulator

    Science.gov (United States)

    Johnson, S. M.; Simon, F. F.

    1976-01-01

    The measured thermal efficiencies of 35 collectors tested with a solar simulator, along with the correlation equations used to generalize the data, are presented in this report. The single correlation used is shown to apply to all the different types of collectors tested, including one with black paint and one cover, one with a selective surface coating and two covers, and an evacuated-tube collector. The test and correlation technique is also modified by using a shield so that collectors larger than the simulator test area can also be tested. This technique was verified experimentally for a shielded collector for which the collector shielded area was 31% of the solar simulator radiation area. A table lists all the collectors tested, the collector areas, and the experimental constants used to correlate the data for each collector.

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

    Science.gov (United States)

    Charvat, Pavel; Ostry, Milan; Mauder, Tomas; Klimes, Lubomir

    2012-04-01

    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).

  2. 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.

  3. Experimental investigation of a nanofluid absorber employed in a low-profile, concentrated solar thermal collector

    Science.gov (United States)

    Li, Qiyuan; Zheng, Cheng; Mesgari, Sara; Hewakuruppu, Yasitha L.; Hjerrild, Natasha; Crisostomo, Felipe; Morrison, Karl; Woffenden, Albert; Rosengarten, Gary; Scott, Jason A.; Taylor, Robert A.

    2015-12-01

    Recent studies [1-3] have demonstrated that nanotechnology, in the form of nanoparticles suspended in water and organic liquids, can be employed to enhance solar collection via direct volumetric absorbers. However, current nanofluid solar collector experimental studies are either relevant to low-temperature flat plate solar collectors (100 °C) indoor laboratory-scale concentrating solar collectors [1, 5]. Moreover, many of these studies involve in thermal properties of nanofluid (such as thermal conductivity) enhancement in solar collectors by using conventional selective coated steel/copper tube receivers [6], and no full-scale concentrating collector has been tested at outdoor condition by employing nanofluid absorber [2, 6]. Thus, there is a need of experimental researches to evaluate the exact performance of full-scale concentrating solar collector by employing nanofluids absorber at outdoor condition. As reported previously [7-9], a low profile (solar thermal concentrating collector was designed and analysed which can potentially supply thermal energy in the 100-250 °C range (an application currently met by gas and electricity). The present study focuses on the design and experimental investigation of a nanofluid absorber employed in this newly designed collector. The nanofluid absorber consists of glass tubes used to contain chemically functionalized multi-walled carbon nanotubes (MWCNTs) dispersed in DI water. MWCNTs (average diameter of 6-13 nm and average length of 2.5-20 μm) were functionalized by potassium persulfate as an oxidant. The nanofluids were prepared with a MCWNT concentration of 50 +/- 0.1 mg/L to form a balance between solar absorption depth and viscosity (e.g. pumping power). Moreover, experimentally comparison of the thermal efficiency between two receivers (a black chrome-coated copper tube versus a MWCNT nanofluid contained within a glass tubetube) is investigated. Thermal experimentation reveals that while the collector efficiency

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

    OpenAIRE

    Klimes Lubomir; Mauder Tomas; Ostry Milan; Charvat Pavel

    2012-01-01

    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...

  5. 一种新型双效太阳能平板集热器的光热性能研究%STUDY OF THERMAL PERFORMANCE OF A NOVEL DUAL-FUNCTION FLAT PLATE SOLAR COLLECTOR

    Institute of Scientific and Technical Information of China (English)

    季杰; 马进伟; 孙炜; 张杨; 范雯; 何伟; 张爱凤

    2011-01-01

    A novel flat-plane solar collector with L-shaped fins was proposed in this paper, which worked as air heater or water heater according to the season and applications. Experimental investigation was carried out to study the performance of the collector under different operating conditions. The experimental results indicate that the thermal efficiency reaches 40% as air heater that is higher than conventional flat plane air heater, the thermal efficiency of the collector is 49.7% as water heater. Therefore the novel collector can be applied as both air heater and water heater with high efficiency.%提出一种新型太阳能平板集热器,可实现加热空气与加热水两种工作模式,并设计了一种新型的“L”型翅片结构将两种功能有效结合.对这种新型集热器的不同工况分别进行了实验测试,得到两种工作状态下的太阳能光热转换效率.实验表明,空气集热日平均光热转换效率可达到40%以上,高于传统的空气集热器;水集热的效率达到49.7%.两种集热功能均能以高效率实现.

  6. An analytical comparison of the efficiency of solar thermal collector arrays with and without external manifolds

    Science.gov (United States)

    1981-01-01

    An analytical comparison of the efficiency of solar thermal collector arrays with and without external manifolds is reported. A FORTRAN computer program was written for the computation of the thermal performance of solar thermal collector arrays with and without external manifolds. Arrays constructed from two example solar thermal collectors are computated. Typical external manifold sizes and thermal insulations are presented graphically and are compared with the thermal performance of the collector alone.

  7. A Didactic Experiment and Model of a Flat-Plate Solar Collector

    Science.gov (United States)

    Gallitto, Aurelio Agliolo; Fiordilino, Emilio

    2011-01-01

    We report on an experiment performed with a home-made flat-plate solar collector, carried out together with high-school students. To explain the experimental results, we propose a model that describes the heating process of the solar collector. The model accounts quantitatively for the experimental data. We suggest that solar-energy topics should…

  8. Performance Evaluation of a Solar Dryer with Finny, Perforated Absorber Plate Collector Equipped with an Air Temperature Control System for Dill Drying

    Directory of Open Access Journals (Sweden)

    M Razmipour

    2015-03-01

    Full Text Available Dill is one of the most important plants in the world because of its medicinal properties and it is widely used as a vegetable in the most parts of Iran. In the present study a new solar dryer with finny, perforated absorber plate collector was utilized to dry fresh dill. The dryer was comprised of a solar collector, a product container, a fan and a drying air temperature controller. The temperature controller was used as a control system to regulate the drying air temperature. Thermal performance of the dryer with finny, perforated solar collector was compared with that of a simple flat plate solar collector at different airflow rates. The effect of drying air temperature at three levels (45, 55 and 65 °C, the product size at three lengths (3, 5 and 7 cm and two different modes of drying (mixed and indirect on the dryer performance was investigated. The results showed that the finny, perforated absorber plate solar collector could improve the thermal efficiency about 11% in comparison with the flat plate collector and the highest thermal efficiency was achieved at the maximum airflow rate. Meanwhile, increasing the air temperature and decreasing the product size caused a significant reduction in energy consumption. Solar fraction reduced by increasing the air temperature. Finally a maximum dryer efficiency of 70% was observed at air temperature of 65 oC, product size of 3 cm with mixed mode drying.

  9. Heat Transfer Analysis of a Flat-plate Solar Collector Running a Solid Adsorption Refrigerator

    Directory of Open Access Journals (Sweden)

    S. Thiao

    2014-05-01

    Full Text Available Adsorption solar cooling appears to have prospect in the tropical countries. The present study is a theoretical investigation of the performance of a solar adsorption refrigerator using a flat-plate solar collector. The values of glass cover and absorber plate temperatures obtained from numerical solutions of heat balance equations are used to predict the solar coefficient of performance of the solar refrigerator. The simulation technique takes into account the variations of ambient temperature and solar radiation along the day. The effects of optical parameters of the glass cover such as absorption and transmission coefficients on glass cover and absorber plate temperatures and consequently on the coefficient of performance are analyzed. As a result, it is found that the absorber plate temperature is less to the absorption coefficient than the cover glass temperature. Also the thermal radiation exchange has more effect on the cover glass temperature. The higher values of COP are obtained between 11 and 13 h during the morning when the temperatures of the absorber plate and the ambient temperatures increase. Moreover the COP increases with the coefficient of transmission of the glass cover but the main parameter acting on the variations of the COP remains the temperature of the evaporator.

  10. High performance collectors

    Science.gov (United States)

    Ogawa, H.; Hozumi, S.; Mitsumata, T.; Yoshino, K.; Aso, S.; Ebisu, K.

    1983-04-01

    Materials and structures used for flat plate solar collectors and evacuated tubular collectors were examined relative to their overall performance to project effectiveness for building heating and cooling and the feasibility of use for generating industrial process heat. Thermal efficiencies were calculated for black paint single glazed, selective surface single glazed, and selective surface double glazed flat plate collectors. The efficiencies of a single tube and central tube accompanied by two side tube collectors were also studied. Techniques for extending the lifetimes of the collectors were defined. The selective surface collectors proved to have a performance superior to other collectors in terms of the average annual energy delivered. Addition of a black chrome-coated fin system to the evacuated collectors produced significant collection efficiency increases.

  11. Long-term weathering effects on the thermal performance of the Libbey-Owens-Ford (liquid) solar collector

    Science.gov (United States)

    1979-01-01

    Thermal performance tests were conducted on the Libbey-Owens-Ford liquid collector, following long term exposure to natural weathering conditions. Visual inspection of the collector, prior to the retest, indicated noticeable clouding of the inner cover glass, probably resulting from outgassing of the insulation. The absorber plate also showed some discoloration. The test results indicated that performance degradation had occurred at inlet temperatures significantly above ambient. The change in the slope of the efficiency curve, from the original data, is a direct indicator of an increase in the collector heat loss coefficient.

  12. A diagram for defined flat plate solar collector area for solar floor heating

    Energy Technology Data Exchange (ETDEWEB)

    Altuntop, N.; Tekin, Y. [Erciyes University, Dept. of Mechanical Engineering (Turkey); Cengel, Y.A. [Nevada Reno University, Dept. of Mechanical Engineering, NV (United States)

    2000-07-01

    In winters, one of the best ways to heat living areas by using the low- temperature - water obtained from flat-plate solar collectors is the floor heating. In floor heating, low temperature-water (30 + 60 deg C) can be used and heat can be stored in water when solar radiation is not possible. In this study, it is aimed to define collector surface needed to supply heat for floor heating. It is also aimed to define and explain the diagram developed for every heating months. The calculations about the sun geometry are used to define the amount of radiation coming in to the collectors. Formulations are made about the definition of solar radiation absorbed by the collectors, the total heat loss coefficient, and the collector plate surface temperature. These formulations are transformed in to the diagram. In addition, the studies, heat transfer calculations and design parameters about the floor of the heating areas are used. A combined collector floor heating diagram is obtained. This diagram is used to define collector surface area necessary to supply heat for floor heated places. In this diagram, the collector surface area is obtained by giving the heat capacity of the place area, floor surface temperature, approximate modulation distance of the floor, the elevation of city, collector slope angle, wind speed, sun shine lime and the amount of the solar radiation obtained from the solar radiation diagram. (authors)

  13. Influences of the Twisted Strips Insertion on the Performance of Flat Plate Water Solar Collector

    Directory of Open Access Journals (Sweden)

    Jafar M. Hassan

    2015-09-01

    Full Text Available In order to enhance the efficiency of flat plate solar water collectors without changing in its original shape and with low additional cost, twisted strips are inserted inside its riser pipes. Three flat plate collectors are used for test. Family of twisted strips are inserted inside each collector risers with different twisted ratios (TR=3,4,5. The collectors are connected in parallel mode (Z-Configuration and are exposed to the same conditions (solar radiation and ambient temperature .The experimental results show that, the highest heat transfer rate occurs at twisted ratio (3 .Consequently, for the same twisted ratio the daily efficiencies for the solar collector at different flow rate used (60,100 and 150 ℓ /hr. were 49 %, 57% and 63% respectively.

  14. A Numerical Study on the Performance of an Open-type Flat-plate Solar Collector

    OpenAIRE

    Song, Baoyin; Inaba, Hideo; Horibe, Akihiko

    1999-01-01

    A set mathematical models was developed for predicting the performance of an open-type flat-plate solar collector, and solved numerically through an implicit difference method. The effects of various parameters on the absorption of solar energy for the collector were investigated. The results showed that the solar energy absorptance of the open-type flat-plate collector was relatively high especially for the region where the weather was humid and hot, and there were an optimum length and an o...

  15. 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.

  16. A diagram for defined solar radiation absorbed per unit area of flat plate solar collectors

    Energy Technology Data Exchange (ETDEWEB)

    Tekin, Y.; Altuntop, N. [Erciyes University, Dept. of Mechanical Engineering (Turkey); Cengel, Y.A. [Nevada Reno University, Dept. of Mechanical Engineering, NV (United States); Cengel, Y.A. [Nevada University, Dept. Mechanical Engineering, Reno, NV (United States)

    2000-07-01

    In Erciyes University, the Solar House (28.75 m{sup 2}) is heated from the floor by using flat plate liquid solar collectors. Required solar radiation for heating and heat losses are calculated. In this work, the required calculations for Erciyes Solar House were generalized and required calculation were done to evaluate absorbed solar radiation per unit surface of the flat plate liquid collector. At the end, three generalized diagrams for nine different months are obtained using obtained numerical values. The goal of preparing diagrams is to determine absorbed solar radiation per unit surface area of flat plate liquid collector at any instant at any latitude, In this work, the diagram is explained by means of sample calculations for November. This diagram was prepared to find out absorbed solar radiation per unit area of black surface collector by means obtained equations. With this diagram, all instant solar radiation can be evaluated in 19 steps. (authors)

  17. REVIEW ON POROUS AND NON-POROUS FLAT PLATE AIR COLLECTOR WITH MIRROR ENCLOSURE

    Directory of Open Access Journals (Sweden)

    M. PRADHAPRAJ,

    2010-09-01

    Full Text Available In solar air heater, flat plat collectors are the best heat transferring devices. But the effectiveness of these collectorsis very low because of lack of technology. Solar assisted heated air is successfully used for drying applications and space heating under controlled conditions. From the solar flat plate air heater the hot air is transferred to a conventional dryer or to the combined heater and drying chamber directly. Hence, solar assisted air heaters arecheaper and reliable. The important factors affecting these systems are the solar radiation, mechanical loading, temperature and leakage. The air heater efficiency depends on the design of the system as well as the construction materials and the assembly. The solar air heating systems has acceptable life span of 15 to 20 years. The addition ofside mirror enclosures is to increase the amount of solar radiation absorption at the collector plate so that the collector increases the yield and operate in a higher temperature range. Therefore with the addition of side mirrors one can able to maximize the output of fixed flat plate collectors. A flat plate air collector will be more efficient if it is made up of porous medium when comparing it with the non porous collectors according to the study. In this paper, the performances of porous and non-porous absorber plates are discussed. Also the possible methods of finding out air leakages and the methodology adopted for the performance and efficiency calculations are also discussed.

  18. 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.

  19. Use of mirrors with plate collectors; Uso de espejos con colectores planos

    Energy Technology Data Exchange (ETDEWEB)

    Follari, J. A.; Odicino, L. a.; Perello, A. D.; Fasulo, A. J.

    2004-07-01

    We analyze the solar radiative contribution that a fixed flat mirror cam perform on a collector, also fixed in its position , if that mirror is put above the collector. Various angles, be they for the mirror or for the collector are investigated, in order to determine their practical usefulness as a function of the real effective contribution they provide. First the theoretical contribution is calculated using approximative formulae, then the effective contribution to a solar collector connected to a thermal reservoir mow forming a solar heater, is measured. The field of applicability of this device is analyzed considering the cost of collector and the mirror, the usefulness depending on the angle between the collector and the horizontal plain. (Author)

  20. Thermal performance of evacuated tube heat pipe solar collector

    Science.gov (United States)

    Putra, Nandy; Kristian, M. R.; David, R.; Haliansyah, K.; Ariantara, Bambang

    2016-06-01

    The high fossil energy consumption not only causes the scarcity of energy but also raises problems of global warming. Increasing needs of fossil fuel could be reduced through the utilization of solar energy by using solar collectors. Indonesia has the abundant potential for solar energy, but non-renewable energy sources still dominate energy consumption. With heat pipe as passive heat transfer device, evacuated tube solar collector is expected to heat up water for industrial and home usage without external power supply needed to circulate water inside the solar collector. This research was conducted to determine the performance of heat pipe-based evacuated tube solar collector as solar water heater experimentally. The experiments were carried out using stainless steel screen mesh as a wick material, and water and Al2O3-water 0.1% nanofluid as working fluid, and applying inclination angles of 0°, 15°, 30°, and 45°. To analyze the heat absorbed and transferred by the prototype, water at 30°C was circulated through the condenser. A 150 Watt halogen lamp was used as sun simulator, and the prototype was covered by an insulation box to obtain a steady state condition with a minimum affection of ambient changes. Experimental results show that the usage of Al2O3-water 0.1% nanofluid at 30° inclination angle provides the highest thermal performance, which gives efficiency as high as 0.196 and thermal resistance as low as 5.32 °C/W. The use of nanofluid as working fluid enhances thermal performance due to high thermal conductivity of the working fluid. The increase of the inclination angle plays a role in the drainage of the condensate to the evaporator that leads to higher thermal performance until the optimal inclination angle is reached.

  1. The effect of contact spacing on the efficiency of flat plate solar collector plates

    Science.gov (United States)

    Schneider, G. E.; Crha, S.

    1984-01-01

    Rather than use a continuous weld or solder for thermal contact in the attachment of an extended surface to an energy removal tube, attention is given to the use of discontinuous attachment through the uniform distribution of finite regions of contact. This scheme is applied to a solar energy collection system in which it was thought capable of yielding fabrication and reliability improvements. A nondimensional formulation and numerical solution of FEM modeling yields the sensitivity of collector thermal performance to weld-solder joint dimensions. The discontinuous weld is found to significantly degrade system performance in proportion to the fin surface Biot modulus, with the controlling parameter (with respect to weld dimensions) being the perimeter length at the weld location of contact.

  2. 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.

  3. Design, construction and testing of a liquid-heating flat-plate solar collector

    Energy Technology Data Exchange (ETDEWEB)

    Tuttle, R E

    1980-02-01

    The purpose of this study was to design, construct, and test a liquid-heating flat-plate solar collector. From the literature search, information was gathered concerning the basic components of the collector, the different processes and materials that can be used in the construction of these components, and their advantages and disadvantages. The literature search also revealed a method used to measure the performance of the collector in terms of efficiency and heat output. Design considerations were then listed for each of the major components as well as the collector as a single unit. Then, each component was designed, taking into consideration the final assembly of the completed unit. Detailed designs were required for the absorber plate and the box and frame assembly because of their complexity in construction and assembly. Once the components were designed, the construction details were arranged in a logical sequence, again considering the final assembly of the unit. The collector was then carefully constructed and assembled following the design details. After the solar collector was assembled completely, tests were made, data were obtained and recorded, and a collector performance curve was developed.

  4. A reference heat source for solar collector thermal testing

    Science.gov (United States)

    Harrison, S. J.; Bernier, M. A.

    1984-12-01

    A direct-comparison reference heat source (RHS), used for testing liquid-based solar collectors, is described. A major advantage of the RHS is its capability to measure the product of mass flow and specific heat directly in the test loop. Calibration tests are performed on two reference heat sources over a range of flowrates and inlet temperatures normally encountered in flat-plate solar collector testing (10 C to 95 C). It is shown that at low flowrates (less than or equal to 0.008 kg/s), localized boiling may introduce errors if the heater power density is not reduced as well, whereas operation at flowrates greater than 0.05 kg/s reduces the temperature rise across the RHS, increasing temperature measurement uncertainty. To achieve satisfactory results with an RHS, a stable inlet temperature, good flowrate control, and regulation of the power supplied to the heater are required.

  5. 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.

  6. Studies on solar flat plate collector evaporation systems for tannery effluent (soak liquor)

    Institute of Scientific and Technical Information of China (English)

    SRITHAR K.; MANIA.

    2006-01-01

    Heat and mass transfer analysis of an incompressible, laminar boundary layer over solar flat plate collector evaporation systems for tannery effluent (soak liquor) is investigated. The goveming equations are solved for various liquid to air velocity ratios. Profiles of velocity, temperature and concentration as well as their gradients are presented. The heat transfer and mass transfer coefficients thus obtained are used to evaluate mass of water evaporated for an inclined fibre-reinforced plastic (FRP)solar flat plate collector (FPC) with and without cover. Comparison of these results with the experimental performance shows encouraging trend of good agreement between them.

  7. 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

  8. A simulation modeling for optimization of flat plate collector design in Riyadh, Saudi Arabia

    Energy Technology Data Exchange (ETDEWEB)

    Al Ajlan, S.A.; Al Faris, H.; Khonkar, H. [King Abdulaziz City for Science and Technology, Riyadh (Saudi Arabia). Energy Research Inst.

    2003-07-01

    A simulation of forced convection solar heated water system is presented. A computer program is developed consisting of independent subroutines, capable of handling the variation of the collector tube diameter, tube spacing, ambient conditions, material thermal properties, collector and system design optimization. The meteorological data of Riyadh were used as the input in the program to simulate the performance of the collector system. The output of the program is analyzed to optimize the system design in the Riyadh region. The results of the simulations are compared with experimental data. There is a good agreement between the predicted and measured values.(author)

  9. 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

    Full Text Available Introduction Drying is one of the most common methods for storing food and agricultural products. During drying process, free water that causes the growth of microorganisms and spoilage of products is removed from the product. There are several methods for drying of agricultural products. one of the most important methods of investment is drying by using sunlight. Iran is situated at 25- 43oE longitude and mean solar radiation is about 4.9 kwh.m-2.d-1. Because of the proper solar radiations in 95% of the agricultural areas in Iran, solar drying is widely used for drying of fruits and vegetables. The use of solar dryer causes saving in energy consumption and processing costs for drying of products in farms and gardens. Several researchers investigated heat transfer and heat flow in dryers. Selection of appropriate method was carried out for drying of agricultural products using heat pump. Experiments were done and mathematical relationships were estimated to obtain correlation parameters between Reynolds number and Nusselt number for the three cases of solar dryer (cabinet, indirect and combination.The best working conditions were determined for three types of solar collectors (flat, finned and corrugated. In this study, the process of heat transfer and heat transfer coefficient of a solar dryer with and without rotation of absorber plate was compared. Materials and Methods The experiments were conducted in Azarshahr, East Azarbayjan province, Iran in September 2014. Newton's law of thermodynamic was used to analyze the working condition of solar absorber. For this purpose the absorber plate was divided into four equal parts. According to the thermal equations and related boundary conditions as well as the relationship between heat transfer coefficient and the temperature gradient, equation 1 for the Nusselet number obtained: 1 Beside the relationship between Nusselt number and heat transfer coefficient is defined as equation 2: 2 Finally

  10. Heat loss coefficients and effective tau-alpha products for flat-plate collectors with diathermanous covers

    Science.gov (United States)

    Hollands, K. G. T.; Wright, J. L.

    1983-01-01

    This paper presents an efficient algorithm for solving the set of nonlinear equations governing the total heat transfer across an arbitrary number of parallel flat plate solar collector covers, each of which can be partly transparent to longwave thermal radiation. The governing equations are sufficiently general to permit each cover to have asymmetric radiative properties and to account for absorption of solar energy on the individual covers. This theory is shown to be in good agreement with the approximate equations of Whillier (provided certain interpretations are placed on his quantities) and with experiments using a plastic inner cover and bounding plates of various emissivities. Using this theory, it is demonstrated that if the absorber plate has a selective surface, an inner cover transparent to long wave radiation is to be preferred over one which is opaque.

  11. Optical and thermal testing of convection reduction mechanisms in a new 1.2X CPC solar collector

    Science.gov (United States)

    Carvalho, Maria J.; Collares-Pereira, Manuel; de Oliveira, Joao C.; Mendes, Joao F.; Haeberle, A.; Wittwer, Volker

    1994-09-01

    A new non-evacuated solar collector of the CPC type, developed and manufactured in Portugal, is now commercially available. Its design features are unique and deserve a careful study, both of its optical and of its thermal characteristics. The optics is interesting given the unusual shape and the opportunity to test different convection suppression schemes and determine their impacts on the collector's optical performance. As for the collector's thermal behavior it is very interesting to test how simple (and potential marketable) different convection suppression ideas can improve an already very good collector from the heat loss point of view (FUL equals 4.0 W/( degree(s)C.m2)). In the course of the paper a brief description of the collector is given and testing results are presented for the testing carried out in the following situations: (1) (i) measurement of its optical and thermal performance (instantaneous efficiency curve) measured both in E.W. and N.S. collector orientation (the collector has a very wide acceptance angle allowing it to work in N.S. orientation and, thus, function in a thermosyphon mode like any regular flat plate collector, (ii) measurement of its angular acceptance function; (2) measurement of the instantaneous efficiency curve after the introduction of (i) a thin Teflon high transmissivity film below the glass cover, (ii) transparent insulation of the capillary type, inserted also under the glass cover, (iii) measurement of the acceptance angle function in this last situation. In this paper it is shown that the addition of the film reduces the heat loss coefficient by a factor of 1.3 W/( degree(s)C.m2) and the transparent insulation leads only to an improvement of 1.0 W/( degree(s)C.m2) in that same coefficient.

  12. Mathematical Model of Double Pass Photovoltaic Thermal Air Collector with Fins

    Directory of Open Access Journals (Sweden)

    Ebrahim M.A. Alfegi

    2009-01-01

    Full Text Available Problem statement: The efficiency of photovoltaic cells is generally temperature dependent (efficiency decrease when the temperature of the photovoltaic cells increase. This problem can be solved by cooling the solar cells during operation and operated at low temperature. Approach: This study presented a numerical model of double pass Photovoltaic Thermal (PV/T solar air collector with fins attached to the back side of the absorber plate to improve heat transfer to the flowing air for predicting the performance of the system. Results: Five coupled of unsteady nonlinear partial differential equations were formulated by using first order forward scheme in time and second order central difference scheme in space to predict the performance of PV/T solar air heater at different parameters and conditions. The temperatures of the solar cells, outlet fluid temperature and the temperature distribution of every static element in both models were predicted. The performance of the collector including photovoltaic, thermal and combined PV/T collector over range of operating conditions are discussed. Conclusion: Experimental and theoretical results were compared and showed that close agreement between these two values were obtained.

  13. 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

  14. Heat transfer in a low latitude flat-plate solar collector

    Directory of Open Access Journals (Sweden)

    Oko C.O.C.

    2012-01-01

    Full Text Available Study of rate of heat transfer in a flat-plate solar collector is the main subject of this paper. Measurements of collector and working fluid temperatures were carried out for one year covering the harmattan and rainy seasons in Port Harcourt, Nigeria, which is situated at the latitude of 4.858oN and longitude of 8.372oE. Energy balance equations for heat exchanger were employed to develop a mathematical model which relates the working fluid temperature with the vital collector geometric and physical design parameters. The exit fluid temperature was used to compute the rate of heat transfer to the working fluid and the efficiency of the transfer. The optimum fluid temperatures obtained for the harmattan, rainy and yearly (or combined seasons were: 317.4, 314.9 and 316.2 [K], respectively. The corresponding insolation utilized were: 83.23, 76.61 and 79.92 [W/m2], respectively, with the corresponding mean collector efficiency of 0.190, 0.205 and 0.197 [-], respectively. The working fluid flowrate, the collector length and the range of time that gave rise to maximum results were: 0.0093 [kg/s], 2.0 [m] and 12PM - 13.00PM, respectively. There was good agreement between the computed and the measured working fluid temperatures. The results obtained are useful for the optimal design of the solar collector and its operations.

  15. Evaluation of All-Day-Efficiency for selected flat plate and evacuated tube collectors

    Science.gov (United States)

    1981-01-01

    An evaluation of all day efficiency for selected flat plate and evacuated tube collectors is presented. Computations are based on a modified version of the NBSIR 78-1305A procedure for all day efficiency. The ASHMET and NOAA data bases for solar insolation are discussed. Details of the algorithm used to convert total (global) horizontal radiation to the collector tilt plane of the selected sites are given along with tables and graphs which show the results of the tests performed during this evaluation.

  16. Parabolic Trough Photovoltaic/Thermal Collectors: Design and Simulation Model

    Directory of Open Access Journals (Sweden)

    Laura Vanoli

    2012-10-01

    Full Text Available This paper presents a design procedure and a simulation model of a novel concentrating PVT collector. The layout of the PVT system under investigation was derived from a prototype recently presented in literature and commercially available. The prototype consisted in a parabolic trough concentrator and a linear triangular receiver. In that prototype, the bottom surfaces of the receiver are equipped with mono-crystalline silicon cells whereas the top surface is covered by an absorbing surface. The aperture area of the parabola was covered by a glass in order to improve the thermal efficiency of the system. In the modified version of the collector considered in this paper, two changes are implemented: the cover glass was eliminated and the mono-crystalline silicon cells were replaced by triple-junction cells. In order to analyze PVT performance, a detailed mathematical model was implemented. This model is based on zero-dimensional energy balances. The simulation model calculates the temperatures of the main components of the system and the main energy flows Results showed that the performance of the system is excellent even when the fluid temperature is very high (>100 °C. Conversely, both electrical and thermal efficiencies dramatically decrease when the incident beam radiation decreases.

  17. EVALUATION OF FLAT-PLATE PHOTOVOLTAIC THERMAL HYBRID SYSTEMS FOR SOLAR ENERGY UTILIZATION.

    Energy Technology Data Exchange (ETDEWEB)

    ANDREWS,J.W.

    1981-06-01

    The technical and economic attractiveness of combined photovoltaic/thermal (PV/T) solar energy collectors was evaluated. The study was limited to flat-plate collectors since concentrating photovoltaic collectors require active cooling and thus are inherently PV/T collectors, the only decision being whether to use the thermal energy or to dump it. it was also specified at the outset that reduction in required roof area was not to be used as an argument for combining the collection of thermal and electrical energy into one module. Three tests of economic viability were identified, all of which PV/T must pass if it is to be considered a promising alternative: PV/T must prove to be competitive with photovoltaic-only, thermal-only, and side-by-side photovoltaic-plus-thermal collectors and systems. These three tests were applied to systems using low-temperature (unglazed) collectors and to systems using medium-temperature (glazed) collectors in Los Angeles, New York, and Tampa. For photovoltaics, the 1986 DOE cost goals were assumed to have been realized, and for thermal energy collection two technologies were considered: a current technology based on metal and glass, and a future technology based on thin-film plastics. The study showed that for medium-temperature applications PV/T is not an attractive option in any of the locations studied. For low-temperature applications, PV/T appears to be marginally attractive.

  18. EVALUATION OF FLAT-PLATE PHOTOVOLTAIC THERMAL HYBRID SYSTEMS FOR SOLAR ENERGY UTILIZATION.

    Energy Technology Data Exchange (ETDEWEB)

    ANDREWS,J.W.

    1981-06-01

    The technical and economic attractiveness of combined photovoltaic/thermal (PV/T) solar energy collectors was evaluated. The study was limited to flat-plate collectors since concentrating photovoltaic collectors require active cooling and thus are inherently PV/T collectors, the only decision being whether to use the thermal energy or to dump it. it was also specified at the outset that reduction in required roof area was not to be used as an argument for combining the collection of thermal and electrical energy into one module. Three tests of economic viability were identified, all of which PV/T must pass if it is to be considered a promising alternative: PV/T must prove to be competitive with photovoltaic-only, thermal-only, and side-by-side photovoltaic-plus-thermal collectors and systems. These three tests were applied to systems using low-temperature (unglazed) collectors and to systems using medium-temperature (glazed) collectors in Los Angeles, New York, and Tampa. For photovoltaics, the 1986 DOE cost goals were assumed to have been realized, and for thermal energy collection two technologies were considered: a current technology based on metal and glass, and a future technology based on thin-film plastics. The study showed that for medium-temperature applications PV/T is not an attractive option in any of the locations studied. For low-temperature applications, PV/T appears to be marginally attractive.

  19. Indoor test for thermal performance evaluation of Sunworks (liquid) solar collector

    Science.gov (United States)

    Shih, K.

    1977-01-01

    Test procedures used and test results obtained from an evaluation test program conducted on a single covered liquid solar collector under simulated conditions are presented. The test article was a flat plate solar collector using water as the heat transfer medium. The absorber plate was copper with copper tubes bonded by soft solder. The plate was coated with Enthone selective black with an absorptivity factor of .87 approximately .92 and an emissivity factor of .10 approximately .20. A time constant test and incident angle modifier test were conducted to determine the transient effect and the incident angle effect on the collector.

  20. Indoor test for thermal performance of the Sunmaster evacuated tube (liquid) solar collector

    Science.gov (United States)

    1979-01-01

    The test procedures used to obtain the thermal performance data for a solar collector under simulated conditions are presented. Tests included a stagnation test, a time constant test, a thermal efficiency test, an incident angle modifier test, and a hot fill test. All tests were performed at ambient conditions and the transient effect and the incident angle effect on the collector were determined. The solar collector is a water working fluid type.

  1. Fixed flat plate collector with a reversible vee-trough concentrator

    Science.gov (United States)

    Selcuk, M. K.

    1976-01-01

    An asymmetrical-reversible vee-trough concentrator for use both with nonevacuated and evacuated receivers is proposed in order to improve the performance of a fixed flat plate collector. The device is capable of maintaining a year-round concentration factor of about 2 while eliminating the complications of the tilt adjustments of the collector box assembly. Efficiency improvements and cost reductions for temperatures of about 100 and 200 C are offered for the nonvacuum and vacuum tube versions, respectively. A major advantage of the vee-trough is the enhancement of the incident flux, thus extending the collection period. The vacuum collector is suitable for supplying heat to solar Rankine systems, while the nonvacuum version can be used for air conditioning purposes via an absorption air conditioner.

  2. Flat plate collectors as facade elements for domestic hot water and heat insulation. Flachkollektoren als Fassadenelemente zur Brauchwassererwaermung und Waermedaemmung

    Energy Technology Data Exchange (ETDEWEB)

    Flamm, H.; Lochau, R.; Maeiss, M.; Schiele, J.

    1984-07-01

    In a newly constructed south-west-facade 200 m/sup 2/ of flat plate collectors were integrated as construction elements to heat domestic water. The building needs 5-10 m/sup 3/ of hot water per day, i.e. 250-500 kWh/d. The solar circuit runs with a water-glycol-mixture with a specific volume flow rate of 20-40 l/m/sup 2/h. The storage capacity is 8 m/sup 3/, i.e. 40 l/m/sup 2/ collector area. The heating system is bivalent. The total cost was DM 220.000, excepting the cost of facade construction. The observation period was 2 years. The heat flow balance was measured daily using a microprocessor. As far as the construction was concerned, there were no defects during the observation period. The rooms behind solar collectors showed no additional thermal load. The most favourable season for running solar systems is from April to September. In this period the average efficiencies were 15 to 20%, the net energy yield was 76 kWh/m/sup 2/.

  3. Thermal and optical efficiency investigation of a parabolic trough collector

    Directory of Open Access Journals (Sweden)

    C. Tzivanidis

    2015-09-01

    Full Text Available Solar energy utilization is a promising Renewable Energy source for covering a variety of energy needs of our society. This study presents the most well-known solar concentrating system, the parabolic trough collector, which is operating efficiently in high temperatures. The simulation tool of this analysis is the commercial software Solidworks which simulates complicated problems with an easy way using the finite elements method. A small parabolic trough collector model is designed and simulated for different operating conditions. The goal of this study is to predict the efficiency of this model and to analyze the heat transfer phenomena that take place. The efficiency curve is compared to a one dimensional numerical model in order to make a simple validation. Moreover, the temperature distribution in the absorber and inside the tube is presented while the heat flux distribution in the outer surface of the absorber is given. The heat convection coefficient inside the tube is calculated and compared with the theoretical one according to the literature. Also the angle efficiency modifier is calculated in order to predict the thermal and optical efficiency for different operating conditions. The final results show that the PTC model performs efficiently and all the calculations are validated.

  4. Mathematical modeling of photovoltaic thermal PV/T system with v-groove collector

    Science.gov (United States)

    Zohri, M.; Fudholi, A.; Ruslan, M. H.; Sopian, K.

    2017-07-01

    The use of v-groove in solar collector has a higher thermal efficiency in references. Dropping the working heat of photovoltaic panel was able to raise the electrical efficiency performance. Electrical and thermal efficiency were produced by photovoltaic thermal (PV/T) system concurrently. Mathematical modeling based on steady-state thermal analysis of PV/T system with v-groove was conducted. With matrix inversion method, the energy balance equations are explained by means of the investigative method. The comparison results show that in the PV/T system with the V-groove collector is higher temperature, thermal and electrical efficiency than other collectors.

  5. Angular solar absorptance of absorbers used in solar thermal collectors.

    Science.gov (United States)

    Tesfamichael, T; Wäckelgård, E

    1999-07-01

    The optical characterization of solar absorbers for thermal solar collectors is usually performed by measurement of the spectral reflectance at near-normal angle of incidence and calculation of the solar absorptance from the measured reflectance. The solar absorptance is, however, a function of the angle of incidence of the light impinging on the absorber. The total reflectance of two types of commercial solar-selective absorbers, nickel-pigmented anodized aluminum, and sputtered nickel nickel oxide coated aluminum are measured at angles of incidence from 5 to 80 in the wavelength range 300-2500 nm by use of an integrating sphere. From these measurements the angular integrated solar absorptance is determined. Experimental data are compared with theoretical calculations, and it is found that optical thin-film interference effects can explain the significant difference in solar absorptance at higher angles for the two types of absorbers.

  6. Qualification and durability tests - Applications for thermal collectors and photovoltaic modules

    Science.gov (United States)

    Riesch, G.

    Accelerated and abbreviated durability tests for characterizing the long-term reliability of solar thermal and photovoltaic modules are described. The tests have been designed to provoke behaviors which would normally require years to become manifest, thereby allowing lifetime predictions to be made over a short testing period. Increasing the intensity of the potentially damaging agent, e.g., UV radiation, humidity, a combination of both, is one method, and cycling the specimen through exposures and out of them in repetitive rapid succession, such as in thermal cycling, is another. The two techniques can also be combined. Solar flat plate collectors are presently tested for overpressure resistance of the absorber, leak tests, rain penetration, load carrying capacity, resistance to hail impact, and durability under thermal shock. Trials are also run involving exposure to a dry atmosphere, UV radiation, ozone-contaminatead atmosphere, sulfur dioxide, cyclic damp heat, and salt mist. Photovoltaic modules are tested for thermal strength, in mounting twist tests, for insulation integrity, for ice loading, for humidity freezing, temperature cycling, long exposure to high temperatures, in damp heat in long storage, and to the same atmospheric factors as flat plates.

  7. Flat-plate solar-collector performance evaluation with a solar simulator as a basis for collector selection and performance prediction

    Science.gov (United States)

    Simon, F. F.

    1975-01-01

    This paper reports the measured thermal efficiency and evaluation of 23 collectors which differ according to absorber material (copper, aluminum, steel), absorber coating (nonselective black paint, selective copper oxide, selective black nickel, selective black chrome), type of glazing material (glass, Tedlar, Lexan, anti-reflection glass), the use of honeycomb material and the use of vacuum to prevent thermal convection losses. The collectors are given performance rankings based on noon-hour solar conditions and all-day solar conditions. The determination with the simulator of an all-day collector performance is made possible by tests at different incident angles. The solar performance rankings are made based on whether the collector is to be used for pool heating, hot water, absorption air conditioning, heating, or for a solar Rankine machine.

  8. Fin-tube solar collectors

    Science.gov (United States)

    1980-01-01

    Report presents test procedures and results of thermal-performance evaluation of seven commercial fin tube (liquid) solar collector-absorber plates. Tests were conducted indoors at Marshall Space Flight Center Solar simulator. Results are graphically shown along with supporting test data and summary, indicating efficiency as function of collector inlet temperature.

  9. KARAKTERISTIK PENGERINGAN CHIPS MANGGA MENGGUNAKAN KOLEKTOR SURYA KACA GANDA [Characteristics of Mango Chips Drying Using a Double Plated Solar Collector

    Directory of Open Access Journals (Sweden)

    Safrani

    2012-12-01

    Full Text Available The objectives of this research were to study the characteristics of mango chips drying using a double plated solar collector. The materials used were sliced mangoes with the thickness of 3, 6, and 8 mm. The equipments used for this research were double plated solar collector, thermocouple, digital balance, thermometer, vacuum oven, and desiccators. The research parameters included the rate of heat energy absorbed by the double plated solar collector, the heat energy losses, the efficiency of the double plated solar collector and the moisture content of the chips. The results of this study suggested that the use of double plated solar collector could increase the temperature and the amount of heat energy, thus speed up the drying process of the mango chips. The energy needed to evaporate the moisture content in mango decreased in proportion to the increase in drying time. The difference in mango chips’ thickness resulted in different decrease rate in water content until it reached a constant state. The efficiency of the double plated solar collector was 77.82%.

  10. Sensitivity analysis of thermal performances of flat plate solar air heaters

    Science.gov (United States)

    Njomo, Donatien; Daguenet, Michel

    2006-10-01

    Sensitivity analysis is a mathematical tool, first developed for optimization methods, which aim is to characterize a system response through the variations of its output parameters following modifications imposed on the input parameters of the system. Such an analysis may quickly become laborious when the thermal model under consideration is complex or the number of input parameters is high. In this paper, we develop a mathematical model to analyse the heat exchanges in four different types of solar air collectors. When building this thermal model we show that for each collector, at quasi-steady state, the energy balance equations of the components of the collector cascade into a single first-order non-linear differential equation that is able to predict the thermal behaviour of the collector. Our heat transfer model clearly demonstrates the existence of an important dimensionless parameter, referred to as the thermal performance factor of the collector, that compares the useful thermal energy which can be extracted from the heater to the overall thermal losses of that collector for a given set of input parameters. A sensitivity analysis of our thermal model has been performed for the most significant input parameters such as the incident solar irradiation, the inlet fluid temperature, the air mass flow rate, the depth of the fluid channel, the number and nature of the transparent covers in order to measure the impact of each of these parameters on our model. An important result which can be drawn from this study is that the heat transfer model developed is robust enough to be used for thermal design studies of most known flat plate solar air heaters, but also of flat plate solar water collectors and linear solar concentrators.

  11. Indoor test for thermal performance evaluation on the Sunworks (air) solar collector

    Science.gov (United States)

    1978-01-01

    The test procedure used and the results obtained from an evaluation test program conducted to obtain thermal performance data on a Sunworks single glazed air solar collector under simulated conditions are described. A time constant test and incident angle modifier test were conducted to determine the transient effect and the incident angle effect on the collector. These results and the results of the collector load test are also discussed.

  12. Design optimization of sinusoidal glass honeycomb for flat plate solar collectors

    Science.gov (United States)

    Mcmurrin, J. C.; Buchberg, H.

    1980-01-01

    The design of honeycomb made of sinusoidally corrugated glass strips was optimized for use in water-cooled, single-glazed flat plate solar collectors with non-selective black absorbers. Cell diameter (d), cell height (L), and pitch/diameter ratio (P/d) maximizing solar collector performance and cost effectiveness for given cell wall thickness (t sub w) and optical properties of glass were determined from radiative and convective honeycomb characteristics and collector performance all calculated with experimentally validated algorithms. Relative lifetime values were estimated from present materials costs and postulated production methods for corrugated glass honeycomb cover assemblies. A honeycomb with P/d = 1.05, d = 17.4 mm, L = 146 mm and t sub w = 0.15 mm would provide near-optimal performance over the range delta T sub C greater than or equal to 0 C and less than or equal to 80 C and be superior in performance and cost effectiveness to a non-honeycomb collector with a 0.92/0.12 selective black absorber.

  13. 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.

  14. Standard Test Method for Determining Thermal Performance of Tracking Concentrating Solar Collectors

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1987-01-01

    1.1 This test method covers the determination of thermal performance of tracking concentrating solar collectors that heat fluids for use in thermal systems. 1.2 This test method applies to one- or two-axis tracking reflecting concentrating collectors in which the fluid enters the collector through a single inlet and leaves the collector through a single outlet, and to those collectors where a single inlet and outlet can be effectively provided, such as into parallel inlets and outlets of multiple collector modules. 1.3 This test method is intended for those collectors whose design is such that the effects of diffuse irradiance on performance is negligible and whose performance can be characterized in terms of direct irradiance. Note 1—For purposes of clarification, this method shall apply to collectors with a geometric concentration ratio of seven or greater. 1.4 The collector may be tested either as a thermal collection subsystem where the effects of tracking errors have been essentially removed from t...

  15. Instrumentation for measuring direct and diffuse insolation in testing thermal collectors

    Energy Technology Data Exchange (ETDEWEB)

    Reed, K A

    1976-01-01

    The efficiencies of thermal collectors are traditionally expressed with respect to the total (direct beam plus diffuse) insolation at the collector plane. Evaluation of the performance of concentrating collectors, however, requires, in addition, a knowledge of the insolation which is within the angular field of view of the collector. The use of pyranometers to measure the total insolation as well as the insolation within specified angular fields of view, together with a normal incidence pyrheliometer to measure the direct beam component, is described. The instrument calibration procedure is discussed, and several data are presented.

  16. 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 %.

  17. Solar Collector Thermal Power System. Volume 3. Basic Study and Experimental Evaluation of Thermal Train Components

    Science.gov (United States)

    1974-11-01

    the long- lifetime compatibility of sodium and high nickel- chrome alloys (such as Inconel 600) for the thermal train subsystem, an experimental effo...close wound Nichrome V Inconel sheathed resistance heaters were vacuum furnace brazed to the evaporator sections at 1850°F using 82 Au - 18 1. ASTM B...260-BAU-4). Four Inconel sheathed chromel-alumel thermocouples were attached by resistance spot welded Inconel tabs to 40 TABLE VII SOLAR COLLECTOR

  18. Long term weathering effects on the thermal performance of the sunworks (liquid) solar collector

    Science.gov (United States)

    1979-01-01

    The test procedures used and the results obtained during the evaluation test program of the Sunworks single-covered liquid solar collector are presented. The tests were performed under simulated conditions, following long-term exposure to natural weathering conditions. The sunworks collector is a flat-plate solar collector. The absorber plate is copper with copper tubes bonded by soft solder, and is coated with Enthon selective black with an absorptivity factor of .87 similar to .92 and an emissivity factor of .10 similar to .20. It has a single glass cover of 3/16 inches tempered glass and weighs about 115 pounds. The overall dimensions of the collector are 36 x 84 x 4 inches.

  19. Results of thermal performance evaluation of the Owens-Illinois sunpack liquid solar collector at indoor conditions

    Science.gov (United States)

    1979-01-01

    Test procedures and results of the thermal performance of a liquid, evacuated tube, solar collector under simulated conditions are presented. The collector tested was a module used on the early demonstration projects.

  20. Experimental Investigation of Single Pass, Double Duct Photovoltaic Thermal (PV/T) Air Collector with CPC and Fins

    National Research Council Canada - National Science Library

    M. E.A. Alfegi; Kamaruzzaman Sopian; Mohd Y.H. Othman; Baharudin B. Yatim

    2008-01-01

    ...) with the photovoltaic module. Such unit is called photovoltaic/thermal collector (pv/t) or hybrid (pv/t). An experimental investigation of a solar air heater with photovoltaic cell located at the absorber with compound parabolic collector...

  1. 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

    On an average about 40% of world energy is used in residential buildings and the largest energy consumption is allocated to the cooling and air-conditioning systems. So every attempt to economize energy consumption is very valuable. In this research a nocturnal radiative cooling system with flat...... 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...

  2. Flat plate collector with external reflectors (RefleC). Experiences withthe development; Flachkollektor mit externen Reflektoren (RefleC). Entwicklungserfahrungen

    Energy Technology Data Exchange (ETDEWEB)

    Hess, S.; Oliva, A.; Di Lauro, P.; Klemke, M.; Hermann, M.; Stryi-Hipp, G. [Fraunhofer-Institut fuer Solare Energiesysteme ISE, Freiburg (Germany); Kallwellis, V.; Kramp, G.; Eisenmann, W. [Wagner und Co. Solartechnik GmbH, Coelbe (Germany); Hanby, V. [DMU Leicester (United Kingdom). Inst. of Energy and Sustainable Development

    2010-07-01

    In cooperation with the Fraunhofer Institute for Solar Energy Systems (Freiburg, Federal Republic of Germany), the company Wagner and Co. Solar Technology (Coelbe, Federal Republic of Germany) developed a stationary concentrated, double-covered flat plate collector with an external reflector for generating process heat up to a temperature of 150 C. This prototype has a half-CPC reflector which is approximated by three flat segments. The reflectors use the distance between the collectors and serves simultaneously as a supporting structure. The collector is designed so that the aperture is not shaded. The authors of the contribution under consideration present the WKI curves and the IAM curves as a test pattern as well as a simulation of the annual energy yield. According to the simulation, the Reflec-collector has an annual energy yield which is greater by 64 % than that of the double-covered base-collector.

  3. Field Experiments of PV-Thermal Collectors for Residential Application in Bangkok

    OpenAIRE

    Atsushi Akisawa; Yuki Ueda; Pongpith Tuenpusa; Thipjak Nualboonrueng

    2012-01-01

    This study presents experimental results on Photovoltaic-thermal (PVT) solar systems, the commercial photovoltaic (PV) panels used as solar absorbers in PVT collectors, which are amorphous and multi-crystalline silicon. Testing was done with outdoor experiments in the climate of Bangkok corresponding to energy consumption behavior of medium size Thai families. The experimental results show that the thermal recovery of amorphous silicon PVT collector is almost the same as that of multi-crystal...

  4. A two-dimensional thermal analysis of a new high-performance tubular solar collector

    Science.gov (United States)

    Lansing, F. L.; Yung, C. S.

    1979-01-01

    The first of two articles are presented which describe and analyze the thermal performance of a vacuum tube solar collector. The assumptions and mathematical modeling are presented. The problem is reduced to the formulation of two simultaneous linear differential equations characterizing the collector thermal behavior. After applying the boundary conditions, a general solution is obtained which is found similar to the general Hottel, Whillier and Bliss form but with a complex flow factor.

  5. Solar thermal collectors in polymeric materials: A novel approach towards higher operating temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Mendes, Joao Farinha; Horta, Pedro; Carvalho, Maria Joao [INETI - Inst. Nacional de Engenharia Tecnologia e Inovacao, IP, Lisboa (Portugal); Silva, Paulo [PLASDAN - Maquinas para Plasticos, Marinha Grande (Portugal)

    2008-07-01

    The increasing demand for low temperature solar thermal collectors, especially for hot water production purposes in dwellings, swimming pools, hotels or industry, has lead to the possibility of high scale production, with leading manufacturers presenting yearly productions of hundreds of thousands of square meters. In such conditions, the use of polymeric materials in the manufacturing of solar collectors acquires particular interest, opening a full scope of opportunities for lower production costs, by means of cheaper materials or simpler manufacturing operations. Yet, the use of low cost materials limits the maximum operating temperatures estimated for the collectors (stagnation) to values around 120 C, easily attainable by any simple glazed solar collector. Higher performances, leading to higher stagnation temperatures as those observed for regular metal-based solar thermal collectors, would require high temperature polymers, at a much higher cost. The present paper addresses the manufacturing of a high performance solar thermal collector based in polymeric materials and includes a base thermal study, highlighting the different possibilities to be followed in the production of a polymeric collector, as well as a description of different temperature control strategies. (orig.)

  6. 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.

  7. Long-term weathering effects on the thermal performance of the Lennox/Honeywell (liquid) solar collector

    Science.gov (United States)

    1978-01-01

    The test procedures used and the results obtained during the evaluation test program of the Lennox/Honeywell double covered liquid solar collector. The tests were performed under simulated conditions, following long-term exposure to natural weathering conditions. The Lennox/Honeywell collector is a flat-plate solar collector. The absorber plate is steel with copper tubes bonded on the upper surface, and is coated with black chrome. Visual inspection of the collector indicated slight discoloration of the absorber plate. Results indicate that performance degradation had occurred. Absorptivity and/or transmissivity decreased as a result of the weathering.

  8. Proceedings of the solar thermal concentrating collector technology symposium

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, B.P.; Kreith, F. (eds.)

    1978-08-01

    The purpose of the symposium was to review the current status of the concentrating collector technology, to disseminate the information gained from experience in operating solar systems, and to highlight the significant areas of technology development that must be vigorously pursued to foster early commercialization of concentrating solar collectors. Separate abstracts were prepared for thirteen invited papers and working group summaries. Two papers were previously abstracted for EDB.

  9. Solar energy dryer kinetics using flat-plate finned collector and forced convection for potato drying

    Science.gov (United States)

    Batubara, Fatimah; Misran, Erni; Dina, Sari Farah; Heppy

    2017-06-01

    Research on potato drying using the indirect solar dryer with flat-plate finned collector and forced convection has been done. The research was conducted at the outdoor field of Laboratory of Institute for Research and Standardization of Industry on June 14th-23rd, 2016 from 9:00 am to 4:00 pm. This research aims to obtain the drying kinetics model of potato (Solanumtuberosum L.) using an indirect solar dryer's (ISD) with flat plate-finned collector and forced convection. The result will be compared to the open sun drying (OSD) method. Weather conditions during the drying process took place as follows; surrounding air temperature was in the range 27 to 34.7 °C, relative humidity (RH) 29.5 to 61.0% and the intensity of solar radiation 105.6 to 863.1 Watt/m2. The dried potato thicknesses were 1.0 cm, 1.5 cm and 2.0 cm, with the average initial water content of 76.46%. The average temperature in the collector chamber ranged from 42.2 to 57.4 °C and the drying chamber was at 46.2 °C. The best drying result was obtained from a sample size of 1 cm thickness using the IDS method with an average drying rate of 0.018 kg H2O per kg dry-weight.hour and the water content was constant at 5.02% in 21 hours of drying time. The most suitable kinetics model is Page model, equation MR = exp (-0.049 t1,336) for 1.0 cm thickness, exp (-0.066 t1,222) for 1.5 cm thickness and exp (-0.049 t1,221) for 2.0 cm thickness. The quality of potato drying using ISD method is better than using OSD which can be seen from the color produced.

  10. The Influence of Different Absorbed Coatings on Thermal Effect of Prefabricated Solar Collector Panels

    Directory of Open Access Journals (Sweden)

    Wang Qi

    2016-01-01

    Full Text Available Prefabricated solar collector panels is a kind of new permeability structure of collector panels. For this test, we adopt a certain proportion of copper oxide, magnesium oxide and iron oxide to enamel paint as absorbed panel coating and make two kinds of collector panels for different forms of color by dark green coating and black coating. By the methods of comparison, the two kinds of panel collector efficiency and heat loss coefficient UL were tested. The results showed that there was a slight difference between the heat loss coefficient of prefabricated solar collector panels, using the panel with dark green coating’s comprehensive thermal effect is well than the panel with black coating. The beautiful appearance color is more suitable for building requirements.

  11. Design and Development of a Solar Thermal Collector with Single Axis Solar Tracking Mechanism

    Directory of Open Access Journals (Sweden)

    Theebhan Mogana

    2016-01-01

    Full Text Available The solar energy is a source of energy that is abundant in Malaysia and can be easily harvested. However, because of the rotation of the Earth about its axis, it is impossible to harvest the solar energy to the maximum capacity if the solar thermal collector is placed fix to a certain angle. In this research, a solar thermal dish with single axis solar tracking mechanism that will rotate the dish according to the position of the sun in the sky is designed and developed, so that more solar rays can be reflected to a focal point and solar thermal energy can be harvested from the focal point. Data were collected for different weather conditions and performance of the solar thermal collector with a solar tracker were studied and compared with stationary solar thermal collector.

  12. 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

  13. Indoor test for thermal performance evaluation on life sciences engineering (air) solar collector

    Science.gov (United States)

    1978-01-01

    The test procedure used and the results obtained from an evaluation test program conducted to obtain thermal performance data on a life sciences double-glazed air solar collector under simulated conditions is discussed. These tests were made using the Marshall Space Flight Center's solar simulator. A time constant test and incident angle modifier test were also conducted to determine the transient effect and the incident angle effect on the collector. These results and the results of the collector load test are also discussed.

  14. EXPERIMENTAL RESEARCH ON A HIGH EFFICIENT FLAT PLATE SOLAR COLLECTOR%一种高效平板太阳能集热器试验研究

    Institute of Scientific and Technical Information of China (English)

    李戬洪; 江晴

    2001-01-01

    性能良好的太阳能集热器是太阳能空调的关键设备之一。广东省江门市太阳能空调系统采用了一种高效的平板集热器,其主要技术特征是增加了一块聚碳酸脂(PC)透明隔热板。本研究通过对比试验,确定了一种高效平板太阳能集热器的技术方案,并测定了瞬时效率曲线,其热损系数仅为2.90W/(m2*℃)。%Good performance of the solar collectors is one of the important elements for solar air-conditioning system.A novel type of high efficient flat plate solar collector was applied to the solar air-condition system in Jiangmen,Guangdong Province.Tests show that adding a transparent polycarbonate sheet in gap between glazing and absorber of the collector. The coefficient of the thermal loss is reduced to 2.90W/(m2℃) and the performance of the collector is improved.

  15. Status of the NASA-Lewis flat-plate collector tests with a solar simulator

    Science.gov (United States)

    Simon, F. F.

    1974-01-01

    Simulator test results of 15 collector types are reported. Collectors are given performance ratings according to their use for pool heating, hot water, absorption A/C or heating and solar Rankine machines. Collectors found to be good performers in the above categories, except for pool heating, were a black nickel coated, 2 glass collector, and a black paint 2 glass collector containing a mylar honeycomb. For pool heating, a black paint, one glass collector was found to be the best performer. Collector performance parameters of 5 collector types were determined to aid in explaining the factors that govern performance. The two factors that had the greatest effect on collector performance were the collector heat loss and the coating absorptivity.

  16. Standard Test Method for Water Penetration of Flat Plate Solar Collectors by Uniform Static Air Pressure Difference

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1986-01-01

    1.1 This test method covers the determination of the resistance of flat plate solar collectors to water penetration when water is applied to their outer surfaces with a static air pressure at the outer surface higher than the pressure at the interior of the collector. 1.2 This test method is applicable to any flat plate solar collector. 1.3 The proper use of this test method requires a knowledge of the principles of pressure and deflection measurement. 1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 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. Specific precautionary information is contained in Section 6.

  17. Numerical analysis of flow and heat transfer behavior in fin-tube flat-plate solar collector

    Institute of Scientific and Technical Information of China (English)

    Namory Camara; LU Hui-lin

    2007-01-01

    Temperature distribution over the absorber plate of a parallel flow flat-plate solar collector is numerically analyzed. The governing differential equations with boundary conditions are solved numerically using fluent software. Effects of the inlet mass flux, inlet temperature and tube spacing on velocity and temperature distributions are discussed. Numerical results show that the distributions of velocity and temperature of fluid is unsymmetrical inside pipe.

  18. 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

  19. Towards standardization of in-site parabolic trough collector testing in solar thermal power plants

    Science.gov (United States)

    Sallaberry, Fabienne; Valenzuela, Loreto; de Jalón, Alberto García; Leon, Javier; Bernad, Ignacio David

    2016-05-01

    This paper presents a summary of the testing procedure and a validation of the methodology of parabolic trough collector in solar thermal power plants. The applied testing methodology is the one proposed within the Spanish standardization sub-committee AEN/CTN 206/SC117 working group WG2 related to the components for solar thermal power plants. This methodology is also proposed within the international committee IEC TC 117 (Standard draft IEC 62862-3-2 Ed. 1.0). This study is done at Plataforma Solar de Almería (PSA) in Almeria within the European project STAGE-STE. This paper presents the results of the optical and thermal efficiency of a large-size parabolic trough collector. The obtained values are similar to the previous analysis on this collector by PSA. The results of the tracking system have a good accuracy compared to the acceptance angle of the concentrator.

  20. Indoor test for thermal performance evaluation of Lenox-Honeywell solar collector. [conducted using Marshall Space Flight Center Solar Simulator

    Science.gov (United States)

    Shih, K.

    1977-01-01

    The test procedures used and the test results obtained from an evaluation test program conducted on a double-covered liquid solar collector under simulated conditions are presented. The test article was a flat plate solar collector using liquid as the heat transfer medium. The absorber plate was steel with the copper tubes bonded on the upper surface. The plate was coated with black chrome with an absorptivity factor of .95 and emissivity factor of .12. A time constant test and incident angle modifier test were conducted to determine the transient effect and the incident angle effect on the collector.

  1. Desiccant cooling using unglazed transpired solar collectors

    Science.gov (United States)

    Pesaran, A. A.; Wipke, K.

    1992-05-01

    The use of unglazed solar collectors for desiccant regeneration in a solid desiccant cooling cycle was investigated because these collectors are lower in cost than conventional glazed flat-plate collectors. Using computer models, the performance of a desiccant cooling ventilation cycle integrated with either unglazed transpired collectors or conventional glazed flat-plate collectors was obtained. We found that the thermal performance of the unglazed system was lower than the thermal performance of the glazed system because the unglazed system could not take advantage of the heat of adsorption released during the dehumidification process. For a 3-ton cooling system, although the area required for the unglazed collector was 69 percent more than that required for the glazed collector, the cost of the unglazed collector array was 44 percent less than the cost of the glazed collector array. The simple payback period of the unglazed system was half of the payback period of the glazed collector when compared to an equivalent gas-fired system. Although the use of unglazed transpired collectors makes economic sense, some practical considerations may limit their use in desiccant regeneration.

  2. Long term weathering effects on the thermal performance of the solaron (air) solar collector

    Science.gov (United States)

    1979-01-01

    The test procedures and the results obtained during the evaluation test program on the Solaron Corporation air-type solar collector are presented. The tests were performed under simulated conditions, following long-term exposure to natural weathering conditions. The Solaron Model 2001, air-type solar collector has a gross area of 19 square feet and the weight is 160 pounds. The absorber plate is made of 24-gage steel, the coating is baked-on black paint, the cover consists of two sheets of 1/8-inch low-iron tempered glass, and the insulation is one thickness of 3 5/8-inch fiberglass batting.

  3. Standard Practice for Evaluating Thermal Insulation Materials for Use in Solar Collectors

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1994-01-01

    1.1 This practice sets forth a testing methodology for evaluating the properties of thermal insulation materials to be used in solar collectors with concentration ratios of less than 10. Tests are given herein to evaluate the pH, surface burning characteristics, moisture adsorption, water absorption, thermal resistance, linear shrinkage (or expansion), hot surface performance, and accelerated aging. This practice provides a test for surface burning characteristics but does not provide a methodology for determining combustibility performance of thermal insulation materials. 1.2 The tests shall apply to blanket, rigid board, loose-fill, and foam thermal insulation materials used in solar collectors. Other thermal insulation materials shall be tested in accordance with the provisions set forth herein and should not be excluded from consideration. 1.3 The assumption is made that elevated temperature, moisture, and applied stresses are the primary factors contributing to the degradation of thermal insulation mat...

  4. Unglazed photovoltaic-thermal solar collector in heat pump systems; Unverglaste photovoltaisch-thermische Kollektoren in Waermepumpensystemen

    Energy Technology Data Exchange (ETDEWEB)

    Bertram, E.; Stegmann, M.; Scheuren, J. [Institut fuer Solarenergieforschung GmbH Hameln/Emmerthal (ISFH), Emmerthal (Germany); Rosinski, C.; Kundmueller, K. [GEFGA mbH und Co. KG, Limburg (Germany)

    2010-07-01

    Photovoltaic-thermal solar collectors simultaneously produce electricity and heat. The desired temperature levels for the electric and thermal utilization commonly are contrary to each other. In combination with heat pump systems, unglazed photovoltaic-thermal solar collectors offer a promising application due to their low temperature level. Under this aspect, unglazed photovoltaic-thermal solar collectors are investigated in simulation and experiment within a research project at the Institute for Solar Energy Research (Hameln/Emmerthal, Federal Republic of Germany). The authors of the contribution under consideration report on results from the ongoing first year of operation of a pilot plant, measurements of performance on photovoltaic-thermal solar collectors and the developed model for an unglazed photovoltaic-thermal solar collector.

  5. Experimental investigation on a parabolic trough solar collector for thermal power generation

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Developing solar thermal power technology in an effective manner is a great challenge in China.In this paper an experiment platform of a parabolic trough solar collector system(PTCS) was developed for thermal power generation,and the performance of the PTCS was experimentally investigated with synthetic oil as the circulate heat transfer fluid(HTF).The solar collector’s efficiency with the variation of the solar flux and the flow rate of the HTF was identified.The collector efficiency of the PTCS can be in the range of 40%-60%.It was also found that there existed a specified delay for the temperature of the HTF to response to the solar flux,which played a significant role in designing the PTCS.The heat loss effect on collector efficiency was also studied,which was about 220 W/m for the receiver with a 180°C temperature difference between the collector temperature and the ambient temperature,amounting to about 10% of the total solar energy incident on the collector.The encouraging results can provide fundamental data for developing the parabolic trough solar thermal power plant in China.

  6. Experimental Study on Performance of a Box Solar Cooker with Flat Plate Collector to Boil Water

    Science.gov (United States)

    Sitepu, T.; Gunawan, S.; Nasution, D. M.; Ambarita, H.; Siregar, R. E. T.; Ronowikarto, A. D.

    2017-03-01

    In this study, a flat plate type solar cooker is tested by exposing in solar irradiation. The objective is to examine the performance of solar cooker in boiling water. The solar cooker is a box type with collector area and height are 100 × 100 cm and 40 cm, respectively. Vessel for water is made of aluminum plate with diameter and height of 22 cm and 15 cm. The experiments are performed by varying mass of the water. It is 2 kg and 4 kg, respectively. Every experiment starts from 10:00 AM until the boiling temperature is reached. The parameters measured are radiance intensity, ambient and solar box cooker temperatures, and wind speed. The results show that the duration of water heating up to 100°C with water mass 2 kg within 2 hours 45 minutes and water mass 4 kg within 3 hours 17 minutes. The maximum temperatur of solar box cooker is 117°C at 12:56 PM and maximum efficiency is 46.30%. The main conclusion can be drawn here is that a simple solar box cooker can be used to boil water.

  7. 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......-plate collectors used as the test section. Two correlations were proposed for the Nusselt number as a function of the Reynolds number and the Prandtl number based on hydraulic diameter for various heat fluxes. The temperature distribution along the finned tube for the fluid and the wall were also illustrated....

  8. Study on a Flat Plate Solar Air Collector with Baffles%扰流板型太阳能平板空气集热器集热性能

    Institute of Scientific and Technical Information of China (English)

    夏佰林; 赵东亮; 代彦军; 李勇

    2011-01-01

    对一种扰流板型太阳能平板空气集热器的集热性能进行了研究,并对各种影响集热器热性能的因素进行了分析,揭示了总热损失系数、扰流板肋片效率、流道内空气流速和扰流板的间距对效率因子和热迁移因子的影响机理.获得了扰流板型太阳能平板空气集热器的集热效率理论表达式,为此类太阳能空气集热器的设计及应用提供了参考.%A flat plate solar air collector with baffles was studied. Several factors that have influence on the thermal performance of the solar collectors were analyzed. The paper investigated the relations between the efficiency factor, the heat-removal factor of the solar air collector and the total heat loss coefficient, baffles fin efficiency, air velocity inside the flow channel, the space between baffles, and the height of baffles. Also, the time constant of the collectors was studied. The theoretical formula of the collector's thermal efficiency was obtained, which can be used for design and application of such kind of collectors.

  9. Compendium of information on identification and testing of materials for plastic solar thermal collectors

    Energy Technology Data Exchange (ETDEWEB)

    McGinniss, V.D.; Sliemers, F.A.; Landstrom, D.K.; Talbert, S.G.

    1980-07-31

    This report is intended to organize and summarize prior and current literature concerning the weathering, aging, durability, degradation, and testing methodologies as applied to materials for plastic solar thermal collectors. Topics covered include (1) rate of aging of polymeric materials; (2) environmental factors affecting performance; (3) evaluation and prediction of service life; (4) measurement of physical and chemical properties; (5) discussion of evaluation techniques and specific instrumentation; (6) degradation reactions and mechanisms; (7) weathering of specific polymeric materials; and (8) exposure testing methodology. Major emphasis has been placed on defining the current state of the art in plastics degradation and on identifying information that can be utilized in applying appropriate and effective aging tests for use in projecting service life of plastic solar thermal collectors. This information will also be of value where polymeric components are utilized in the construction of conventional solar collectors or any application where plastic degradation and weathering are prime factors in material selection.

  10. Design of an Energy System Based on Photovoltaic Thermal Collectors in the South of Algeria

    Directory of Open Access Journals (Sweden)

    K. Touafek

    2014-01-01

    Full Text Available The objective of this work is the design of a new energy system where the energy source will be provided by solar photovoltaic thermal (PV/T hybrid collectors. This system will be applied to a habitation in the region of Ghardaïa in the south of Algeria. The cold water reaches the thermal storage tank and then will be heated by the hybrid collector. The hot water will be used directly as sanitary water. The electric power produced by the hybrid collector will be used to charge the battery and will be delivered to the load (electrical appliances, lamps, etc.. Two types of loads are considered: a DC load and the other alternating current. The fans located adjacent to the radiators supplied with hot water will provide warm air to the house in winter.

  11. Indoor test and long-term weathering effects on the thermal performance of the solar energy system (liquid) solar collector. [Marshall Space Flight Center solar test facility and solar simulator

    Science.gov (United States)

    1979-01-01

    The procedures used and the results obtained during the evaluation test program on a liquid solar collector are presented. The narrow flat plate collector with reflective concentrating mirrors uses water as the working fluid. The double-covered collector weighs 137 pounds and has overall dimensions of about 35" by 77" by 6.75". The test program was conducted to obtain the following information: thermal performance data under simulated conditions, structural behavior under static load, and the effects of long term exposure to natural weathering.

  12. Effect of Position of Upper Connecting Pipe on the Tank on Thermal Performance of Domestic Solar Water Heaters with a Vertical Storage Tank and Flat-plate Collectors%上循环管位置对平板型家用太阳能热水器性能的影响

    Institute of Scientific and Technical Information of China (English)

    朱海威; 高文峰; 林文贤; 刘滔; 李泽东

    2014-01-01

    In this paper,the domestic solar water heater with a vertical storage tank and a flat-plat collector,which is commercially available and popular in the market,was experimentally in-vestigated.Firstly, natural circulation experiment platform of flat plate domestic solar water heater was set up.The effect of two different positions of upper connecting pipe on temperature variation in the water tank during the heating stage in the daytime and thermal performances was measured.Through the analysis of test data,The difference of temperature stratification in the water tank with upper connecting pipe at high position and at low position were studied re-spectively.Also the instantaneous efficiency in 10 minutes was defined and compared.The results showed that there was better temperature stratification in the water tank when it’s upper con-necting pipe at high position during heating stage.In addition,the instantaneous efficiency of so-lar water heater,which water tank with upper connecting pipe at high location under the natural circulation condition was superior to the water tank with upper circulation pipe at low position.%对一种常见的平板型立式储热水箱家用太阳能热水器进行试验分析。搭建了自然循环平板型家用太阳能热水器的实验平台。测量了两种不同位置的上循环管对白天加热阶段储热水箱温度变化及对热性能的影响,通过测试数据分析对比了高、低位上循环管循环时,水箱内温度变化、分层状况,定义了十分钟内的平均效率,并进行了比较。结果表明:储热水箱升温阶段采用高位上循环管的水箱内部出现较好的水温分层;高位上循环管热水器的自然循环瞬时效率比低位上循环管热水器的瞬时效率高。

  13. Experimental investigation on a flat plate solar collector using Al2O3 Nanofluid as a heat transfer agent

    Directory of Open Access Journals (Sweden)

    Abbas Sahi Shareef, Mohammed Hassan Abbod, Sura Qahtan Kadhim

    2015-01-01

    Full Text Available This work introduces experimental results of an Al2O3 -water based nanofluid as the working fluid for flat tube in plate type solar collector. Experimental test setup comprises a solar collector, closed working fluid system and measurement devices (flow meter, thermocouples, temperature meter and digital solar power meter. The Base case was experimented with di-ionized water with a flow rate of 1 lpm. In second case, Al2O3 nanoparticles are mixed in di-ionized water to get nanofluid of 0.5% volume fraction concentration. The maximum difference between outlet and inlet temperatures of the solar collector was 14.4 ̊ C with the solar irradiance of about 788 W/m2 while in case of water the maximum temperatures difference was 10.7 ̊ C with a solar irradiance of about 781 W/m2.

  14. Thermal performance of solar air collector with transparent honeycomb made of glass tube

    Institute of Scientific and Technical Information of China (English)

    ZHANG ZhiQiang; ZUO Ran; LI Ping; SU WenJia

    2009-01-01

    Transparent honeycomb structure with thin-walled glass tube as the honeycomb unit is designed and applied to a flat-plate solar air collector.Experiments are performed for solar collectors with six different honeycomb sizes.The emphasis is to study the effects of diameter and aspect ratio of the honeycomb unit on the transmittance and efficiency of the solar collector.It is shown that for the same diameter but different aspect ratios,there are large temperature differences between the collector's exits;the smaller the aspect ratio,the larger the exit temperature,with a maximum difference of 10℃;for the same aspect ratio but different diameters,the temperature differences are small;the maximum temperature difference between the collectors with and without honeycombs is 12℃.A theoretical expression for the honeycomb transmittance is derived with a simplified method.The result shows that the honeycomb transmittance is only related with the aspect ratio and the materials' optical properties but not the actual size of the honeycomb.

  15. Field Experiments of PV-Thermal Collectors for Residential Application in Bangkok

    Directory of Open Access Journals (Sweden)

    Atsushi Akisawa

    2012-04-01

    Full Text Available This study presents experimental results on Photovoltaic-thermal (PVT solar systems, the commercial photovoltaic (PV panels used as solar absorbers in PVT collectors, which are amorphous and multi-crystalline silicon. Testing was done with outdoor experiments in the climate of Bangkok corresponding to energy consumption behavior of medium size Thai families. The experimental results show that the thermal recovery of amorphous silicon PVT collector is almost the same as that of multi-crystalline silicon PVT collectors while electricity generation of multi crystalline silicon PVT is 1.2 times as much as that of amorphous silicon PVT. The maximum of heat gain from the PVT systems were obtained in March in summer. It was found that PVT collectors of unit area annually produced 1.1 × 103 kWh/m2 .year of heat and 55–83 kWh/m2.year of electricity, respectively. The results show that annual average solar factor of hot water supply is 0.45 for unit collector area. Economical evaluation based on energy costs in Thailand was conducted, which estimated the payback time would be 7 and 14 years for a-Si PVT and mc-Si PV, respectively.

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

    NARCIS (Netherlands)

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

    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,

  17. Spillage and flux density on a receiver aperture lip. [of solar thermal collector

    Science.gov (United States)

    Jaffe, L. D.

    1985-01-01

    In a dish-type point-focusing solar thermal collector, the spillage and the flux density on the receiver aperture lip are related in a very simple way, if the aperture is circular and centered on the optical axis. Specifically, the flux density on the lip is equal to the spillage times the peak flux density in the plane of the lip.

  18. Development of Proposed Standards for Testing Solar Collectors and Thermal Storage Devices. NBS Technical Note 899.

    Science.gov (United States)

    Hill, James E.; And Others

    A study has been made at the National Bureau of Standards of the different techniques that are or could be used for testing solar collectors and thermal storage devices that are used in solar heating and cooling systems. This report reviews the various testing methods and outlines a recommended test procedure, including apparatus and…

  19. 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,

  20. Solar Collectors

    Science.gov (United States)

    1980-01-01

    Solar Energy's solar panels are collectors for a solar energy system which provides heating for a drive-in bank in Akron, OH. Collectors were designed and manufactured by Solar Energy Products, a firm established by three former NASA employees. Company President, Frank Rom, an example of a personnel-type technology transfer, was a Research Director at Lewis Research Center, which conducts extensive solar heating and cooling research, including development and testing of high-efficiency flat-plate collectors. Rom acquired solar energy expertise which helped the company develop two types of collectors, one for use in domestic/commercial heating systems and the other for drying grain.

  1. Performance correlations of five solar collectors tested simultaneously outdoors

    Science.gov (United States)

    Miller, D. R.

    1976-01-01

    Collector thermal efficiency, and efficiency degradation with time were measured for 5 flat-plate solar collectors tested simultaneously in an outdoor solar collector test facility. Results indicate that by using collector performance parameters which account for diffuse insolation, outdoor data recorded on 'cloudy' days can be used as a measure of performance, as long as the ratio of direct to total insolation exceeds approximately 0.6. These outdoor results also show good agreement with thermal efficiency data obtained indoors in a solar simulator. Significant efficiency degradation occurred on only one of the five collectors exposed to outdoor conditions for a period of one to two years.

  2. Demonstration of Solar Heating and Cooling System using Sorption Integrated Solar Thermal Collectors

    OpenAIRE

    Blackman, Corey; Bales, Chris; Hallström, Olof

    2014-01-01

    Producing cost-competitive small and medium-sized solar cooling systems is currently a significant challenge. Due to system complexity, extensive engineering, design and equipment costs; the installation costs of solar thermal cooling systems are prohibitively high. In efforts to overcome these limitations, a novel sorption heat pump module has been developed and directly integrated into a solar thermal collector. The module comprises a fully encapsulated sorption tube containing hygroscopic ...

  3. Optimization of Thin-Film Transparent Plastic Honeycomb Covered Flat-Plate Solar Collectors. Phase 2.

    Science.gov (United States)

    2007-11-02

    the former preferred for high-temperature collectors since it is opaque in the longer wavelength region and hence improves the efficiency by reducing re...different temperature regions . The analyses show that collectors equipped with Lexan honeycomb are more cost ef- fective than comparable nonhoneycomb...Contract E(04-3)- 1081. " REFERENCES 1. Francia , G., "A New Collector of Solar Energy -- Theory and Experimental Verification -- Calculation of the

  4. Thermal Performance Analysis of Solar Collectors Installed for Combisystem in the Apartment Building

    Science.gov (United States)

    Žandeckis, A.; Timma, L.; Blumberga, D.; Rochas, C.; Rošā, M.

    2012-01-01

    The paper focuses on the application of wood pellet and solar combisystem for space heating and hot water preparation at apartment buildings under the climate of Northern Europe. A pilot project has been implemented in the city of Sigulda (N 57° 09.410 E 024° 52.194), Latvia. The system was designed and optimised using TRNSYS - a dynamic simulation tool. The pilot project was continuously monitored. To the analysis the heat transfer fluid flow rate and the influence of the inlet temperature on the performance of solar collectors were subjected. The thermal performance of a solar collector loop was studied using a direct method. A multiple regression analysis was carried out using STATGRAPHICS Centurion 16.1.15 with the aim to identify the operational and weather parameters of the system which cause the strongest influence on the collector's performance. The parameters to be used for the system's optimisation have been evaluated.

  5. Dynamic thermal performance analysis of two solar air collectors with and without porous media

    Directory of Open Access Journals (Sweden)

    Abed Qahtan A.

    2016-01-01

    Full Text Available The paper presents the thermal performance comparison between two types of solar air collectors, with and without porous absorber material. In order to simulate the transient processes which occur in the collectors two mathematical models were developed. Each model consists of a set of time dependent equations which describe the energy balance for the main components of the collector considering time-dependent thermo-physical properties and heat transfer coefficients. The theoretical models were validated by experimental data obtained from measurements performed in different meteorological conditions characteristic to the city of Bucharest – Romania (latitude 44°26′ N, longitude 26°6′ E. Good agreement between the simulation results and experimental data was achieved.

  6. Dynamic thermal performance analysis of two solar air collectors with and without porous media

    Directory of Open Access Journals (Sweden)

    Abed Qahtan A.

    2016-01-01

    Full Text Available The paper presents the thermal performance comparison between two types of solar air collectors, with and without porous absorber material. In order to simulate the transient processes which occur in the collectors two mathematical models were developed. Each model consists of a set of time dependent equations which describe the energy balance for the main components of the collector considering time-dependent thermo-physical properties and heat transfer coefficients. The theoretical models were validated by experimental data obtained from measurements performed in different meteorological conditions characteristic to the city of Bucharest – Romania (latitude 44°26′ N, longitude 26°6′ E. Good agreement between the simulation results and experimental data was achieved.

  7. Performance of Polycrystalline Photovoltaic and Thermal Collector (PVT on Serpentine-Parallel Absorbers Design

    Directory of Open Access Journals (Sweden)

    Mustofa Mustofa

    2017-03-01

    Full Text Available This paper presents the performance of an unglazed polycrystalline photovoltaic-thermal PVT on 0.045 kg/s mass flow rate. PVT combine photovoltaic modules and solar thermal collectors, forming a single device that receive solar radiation and produces heat and electricity simultaneously. The collector figures out serpentine-parallel tubes that can prolong fluid heat conductivity from morning till afternoon. During testing, cell PV, inlet and outlet fluid temperaturs were recorded by thermocouple digital LM35 Arduino Mega 2560. Panel voltage and electric current were also noted in which they were connected to computer and presented each second data recorded. But, in this performance only shows in the certain significant time data. This because the electric current was only noted by multimeter device not the digital one. Based on these testing data, average cell efficieny was about 19%, while thermal efficiency of above 50% and correspondeng cell efficiency of 11%, respectively

  8. Thermal performance of solar air collector with transparent honeycomb made of glass tube

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Transparent honeycomb structure with thin-walled glass tube as the honeycomb unit is designed and applied to a flat-plate solar air collector. Experiments are performed for solar collectors with six different honeycomb sizes. The emphasis is to study the effects of diameter and aspect ratio of the honeycomb unit on the transmittance and efficiency of the solar collector. It is shown that for the same diameter but different aspect ratios, there are large temperature differences between the collector’s exits; the smaller the aspect ratio, the larger the exit temperature, with a maximum difference of 10℃; for the same aspect ratio but different diameters, the temperature differences are small; the maximum temperature difference between the collectors with and without honeycombs is 12℃. A theoretical expression for the honeycomb transmittance is derived with a simplified method. The result shows that the honeycomb transmittance is only related with the aspect ratio and the materials’ optical properties but not the actual size of the honeycomb.

  9. Experimental comparison of the thermal performance of unglazed transpired collectors%无盖板渗透型集热器热性能的对比试验

    Institute of Scientific and Technical Information of China (English)

    高立新; 王天成; 孙绍增

    2012-01-01

    The thermal performances of black, dark green and dark blue unglazed transpired solar collectors were tested and compared under real transient outdoor conditions using an experimental solar air heating system. The test results show that solar irradiation and air flow rate are the main influencing factors for the thermal performance of solar air heating system. The average instantaneous thermal efficiency of the black collector under high and low air flow rate is 76.04% and 67.50%, respectively, which are higher than that of conventional glazed flat -plate solar air collectors. Surface color of solar air collectors has effect on its thermal performance. The average instantaneous thermal efficiency of the dark green and dark blue collector under high and low air flow rate is 15% to 22% lower than that of the black collector, temperature rise is 3 ~4 ℃ lower than that of the black collector. However, the thermal performances of dark green and dark blue collector are better than that of conventional flat -plate collectors. Thus, the thermal performance penalty will not be very high with the application of colored unglazed transpired collectors on building facade for aesthetic reasons.%利用太阳能空气加热系统实验台,对黑、深绿和深蓝3种颜色无盖板渗透型集热器的热性能进行了户外瞬态对比试验.试验结果表明:太阳辐射照度和风量是影响系统热性能的重要因素.在高档和低档两种风量下,黑色集热器的瞬时平均热效率分别为76.04%和67.50%,高于普通平板太阳能空气集热器;集热器表面颜色对其热性能有一定影响,在高档和低档两种风量下,深绿色和深蓝色集热器的瞬时平均热效率比黑色集热器低15%~22%,空气温升低3~4℃,但仍然优于普通平板空气集热器.从保持建筑立面美观考虑,无盖板渗透型集热器的集热板可以采用颜色较深的彩色,不会对系统热性能造成较大影响.

  10. Development of a mobile, stand-alone test facility for solar thermal collectors and systems

    Energy Technology Data Exchange (ETDEWEB)

    Bestenlehner, Dominik; Drueck, Harald; Fischer, Stephan; Mueller-Steinhagen, Hans [Solar- und Waermetechnik Stuttgart (SWT), Stuttgart (Germany)

    2008-07-01

    Testing of solar thermal systems and components requires different standards and thus different test facilities. Usually each facility is individually designed and constructed for tests according to a specific test method. For performing tests of solar thermal systems and collectors according to the most popular standards, test laboratories or manufacturers have to invest a huge amount of staff time, resources and capital to set up the required test facilities. A way to overcome this problem is the mobile, stand-alone solar thermal collector and system test facility developed by SWT-Technologie from Stuttgart, Germany, in cooperation with the Institute of Thermodynamics and Thermal Engineering of the University of Stuttgart. The complete test facility is installed inside a conventional 12 foot office container. This mobile container based test facility is delivered to the site of the customer as a turn-key product that can be put into operation within one single day. Even more, the mobile container based test facility is a three-in-one test facility, since it is possible to perform tests according to three different standards and test methods. The performance of solar collectors can be tested according to the European standard EN 12975 or the international standard ISO 9806, respectively. The performance of solar thermal systems can be determined according to the international standards ISO 9459-2 (CSTG-method) and ISO 9495-5 (DST-method). This paper describes the mobile, container based solar collector and system test facility in detail and reports the experience gained so far. (orig.)

  11. Coaxial extrusion conversion concept for polymeric flat plate solar collectors. Final technical report, September 30, 1978-December 31, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Rhodes, R.O.; Chapman, N.J.; Chao, K.C.; Sorenson, K.F.

    1980-01-01

    This study investigated materials and processes for fundamental improvements in flat-plate solar collector cost and performance. The goal was to develop a process for direct conversion of inexpensive raw materials into a completed solar collector unit, without labor intensive assembly operations. It was thought that materials carefully matched to the process and end-use environment would substantially reduce collector costs, as compared to conventional industry practice. The project studied the feasibility of a cost-effective, glazed solar collector, with low labor input, utilizing a coaxial extrusion of compatible polymeric materials. This study evaluated all considered materials for the desired application. In addition, there was a trial extrusion of the leading candidate glazing and absorber materials, which resulted in successfully performing a coaxial extrusion of one cell. At the time the study was conducted, there were no materials available that met the necessary requirements for the specified utilization. It was recommended that, if potentially compatible materials become available, further investigation into the suitability of those materials be researched. Then, if a suitable material was found, proceeding into Phase II would be recommended.

  12. Comparison of the effects of Al2O3 and CuO nanoparticles on the performance of a solar flat-plate collector

    Science.gov (United States)

    Munuswamy, Dinesh Babu; Madhavan, Venkata Ramanan; Mohan, Mukunthan

    2015-12-01

    To improve the efficiency of solar flat-plate collectors further, a study had been carried out wherein the conventional working fluid was replaced by nanofluids. A 25-L/day solar flat-plate water heater with collector area of 0.5 {m}^2 has been designed and fabricated. The thermosyphon system of the solar water heater was monitored at 15 locations using T-type thermocouples. Alumina and CuO nanoparticles were synthesized and characterized using Brunauer-Emmett-Teller and X-ray diffraction techniques and dispersed using ultrasonic mechanism. To stabilize the system at an optimum level, the collector is operated with volume fractions of 0.2% and 0.4% of synthesized Al2O3 and CuO nanoparticles mixed with distilled water and used in the solar flat-plate collector. The temperature profile was compared with different volume fractions of the nanoparticles in the flowing medium. Enhanced heat transfer was observed in the solar flat-plate collector using nanoparticles, and hence, it is inferred that addition of nanoparticles improves the efficiency of the solar water heaters. This paper details the temperature profile observed in the collectors, variation of insolation over the day, and change in efficiency both on the primary side (collector) and on the secondary side (storage tank) of the solar water heater.

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

    Energy Technology Data Exchange (ETDEWEB)

    Solanki, S.C.; Dubey, Swapnil [Centre for Energy Studies, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016 (India); Tiwari, Arvind [Department of Design, Production and Management, University of Twente, Enschede (Netherlands)

    2009-11-15

    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, in a steady state condition, a thermal model has been developed. Comparison between experimental and theoretical results were also been carried out. The thermal and electrical efficiency of the solar heater is 42% and 8.4%, respectively. This test procedure can be used by manufacturers for testing of different types of PV modules in order to optimize its products. (author)

  14. Evaluation of the potential of optical switching materials for overheating protection of thermal solar collectors - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Huot, G.; Roecker, Ch.; Schueler, A.

    2008-01-15

    Providing renewable energy for domestic hot water production and space heating, thermal solar collectors are more and more widespread, and users' expectations with respect to performance and service lifetime are rising continuously. The durability of solar collector materials is a critical point as the collector lifetime should be at least 25 years. Overheating and the resulting stagnation of the collector is a common problem with solar thermal systems. During stagnation high temperatures lead to water evaporation, glycol degradation, and stresses in the collector with increasing pressure. Special precautions are necessary to release this pressure; only mechanical solutions exist nowadays. Additionally, the occurring elevated temperatures lead to degradation of the materials that compose collectors: seals, insulation materials, and also the selective coating which is the most important part of the collector. A promising way to achieve active cooling of collectors without any mechanical device for pressure release or collector emptying is to produce a selective coating which is able to switch its optical properties at a critical temperature Tc. An optical switch allows changing the selective coating efficiency; the goal is to obtain a coating with a poor selectivity above Tc (decreasing of absorptance, increasing of emittance). Obtaining self-cooling collectors will allow increasing collector surfaces on facades and roofs in order to get high efficiency and hot water production during winter without inconvenient overheating during summer. Optical switching of materials can be obtained by many ways. Inorganic and organic thermochromic compounds, and organic thermotropic coatings are the main types of switching coatings that have been studied at EPFL-LESO-PB. Aging studies of organic thermochromic paints fabricated at EPFL suggest that the durability of organic compounds might not be sufficient for glazed metallic collectors. First samples of inorganic coatings

  15. Thermal performance trade-offs for point focusing solar collectors

    Science.gov (United States)

    Wen, L.

    1978-01-01

    Solar thermal conversion performance is assessed in this paper for representative point focusing distributed systems. Trade-off comparisons are made in terms of concentrator quality, solar receiver operating temperature, and power conversion efficiency. Normalized system performance is presented on a unit concentrator area basis for integrated annual electric energy production.

  16. Weathering of a liquid-filled solar collector

    Science.gov (United States)

    1979-01-01

    Report describes procedures and results of tests for effects of weathering on flat-plate liquid solar collector. Thermal performance was measured before and after natural weathering for 15-1/2 months by using Marshall Space Flight solar simulator.

  17. Thermal Aspects Related to the Operation of Photovoltaic Collectors with Water Film Cleaning System

    Directory of Open Access Journals (Sweden)

    Andrei BUTUZA

    2014-02-01

    Full Text Available This study presents an explorative experimental investigation of solar photovoltaic collector's behavior, when equipped with a water film based cleaning system. The study was focused mainly on thermal aspects and demonstrated the thermal potential of the water film, to be used in preheating domestic water. The results obtained in temperate continental climate and in autumn conditions, are in good agreement with similar studies. The electric effects of the water film were also investigated. This category of results was affected by limited precision of the data acquisition but the trend of water film electric effects could be still revealed. The general practical conclusion of the study is that water film cleaning system of the solar photovoltaic collectors can be recommended only with reserves, because of reduced and uncertain global performances.

  18. Photovoltaic/thermal solar hybrid system with bifacial PV module and transparent plane collector

    Energy Technology Data Exchange (ETDEWEB)

    Robles-Ocampo, B. [Instituto Tecnologico de Celaya, Celaya 11111, Guanajuato (Mexico); CINVESTAV-Queretaro, Libramiento Norponiente 2000, Unidad Queretaro, Fracc. Real de Juriquilla, Queretaro, 76230, QRO (Mexico); Ruiz-Vasquez, E.; Canseco-Sanchez, H. [Instituto Tecnologico de Oaxaca, Oaxaca 68030, Oaxaca (Mexico); CINVESTAV-Queretaro, Libramiento Norponiente 2000, Unidad Queretaro, Fracc. Real de Juriquilla, Queretaro, 76230, QRO (Mexico); Cornejo-Meza, R.C. [Instituto Tecnologico de Tepic, av. Tecnologico 2595, Tepic 63175, Nayarit (Mexico); CINVESTAV-Queretaro, Libramiento Norponiente 2000, Unidad Queretaro, Fracc. Real de Juriquilla, Queretaro, 76230, QRO (Mexico); Trapaga-Martinez, G.; Vorobiev, Y.V. [CINVESTAV-Queretaro, Libramiento Norponiente 2000, Unidad Queretaro, Fracc. Real de Juriquilla, Queretaro, 76230, QRO (Mexico); Garcia-Rodriguez, F.J. [Instituto Tecnologico de Celaya, Celaya 11111, Guanajuato (Mexico); Gonzalez-Hernandez, J. [CIMAV, Miguel de Cervantes 120, Chihuahua 31109, Chihuahua (Mexico)

    2007-12-14

    Electric energy production with photovoltaic (PV)/thermal solar hybrid systems can be enhanced with the employment of a bifacial PV module. Experimental model of a PV/thermal hybrid system with such a module was constructed and studied. To make use of both active surfaces of the bifacial PV module, we designed and made an original water-heating planar collector and a set of reflecting planes. The heat collector was transparent in the visible and near-infrared spectral regions, which makes it compatible with the PV module made of crystalline Si. The estimated overall solar energy utilization efficiency for the system related to the direct radiation flux is of the order of 60%, with an electric efficiency of 16.4%. (author)

  19. Structural and Thermal Analysis of Asphalt Solar Collector Using Finite Element Method

    OpenAIRE

    Jinshah Basheer Sheeba; Ajith Krishnan Rohini

    2014-01-01

    The collection of solar energy using asphalt pavements has got a wide importance in the present energy scenario. Asphalt pavements subjected to solar radiation can reach temperature up to 70°C because of their excellent heat absorbing property. Many working parameters, such as pipe diameter, pipe spacing, pipe depth, pipe arrangement, and flow rate, influence the performance of asphalt solar collector. Existing literature on thermal energy extraction from asphalt pavements is based on the sma...

  20. 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.

  1. THEORETICAL STUDY OF SOLAR COLLECTOR WITH MINI PARABOLIC CONCENTRATOR

    Directory of Open Access Journals (Sweden)

    I TABET

    2013-12-01

    Full Text Available In this paper, numerical modeling and simulation of the thermal behavior of a solar collector vacuum tube with a concentration has been done, the value of adding a system of concentration at the back of the collector and try to increase the amount of solar radiation incident on the collector  in order to obtain high temperatures compared to traditional flat plate collector  and improved their energy performance, this type of collector  being integrated into buildings for domestic hot water, air conditioning and for cooling.

  2. Outdoor performance results for NBS Round Robin collector no. 1

    Science.gov (United States)

    Miller, D. R.

    1976-01-01

    The efficiency of a PPG flat-plate solar collector was evaluated utilizing an outdoor solar collector test facility at the NASA-Lewis Research Center, as part of the National Bureau of Standards 'round robin' collector test program. The correlation equation for collector thermal efficiency Eta curve fit of the data was: Eta = 0.666 - 1.003(Btu/hr-sq ft-F) Theta, where the parameter Theta is the difference between the average fluid temperature and the ambient temperature, all divided by the total flux impinging on the collector.

  3. Long-term weathering effects on the thermal performance of the solargenics (liquid) solar collector at outdoor conditions. [Marshall Space Flight Center Solar test facility

    Science.gov (United States)

    1979-01-01

    The test procedures and the results obtained during the evaluation of a single-covered liquid solar collector are presented. The tests were performed under outdoor natural conditions. The collector was under stagnation conditions for a total of approximately ten months. The solar collector is a liquid, single-glazed, flat plate collector, and is about 240 inches long, and 3.8 inches in depth.

  4. Thermal neutron imaging using microchannel plates

    Science.gov (United States)

    Fraser, George W.; Pearson, James F.; Al-Horayess, O. S.; Feller, W. Bruce; Cook, Lee M.

    1993-02-01

    Microchannel plates (MCPs) are compact electron multipliers of high gain, widely used for the high resolution imaging of charged particles and photons. In this paper, we consider the use of lead glass MCPs for the imaging of thermal neutrons. Two contrasting techniques are described. The first method involves direct neutron detection within a special channel plate structure containing lithium and/or boron. We review the constraints of glass chemistry on the attainable lithium oxide and boron oxide fractions and, hence, on the maximum neutron detection efficiency. The second method involves the detection, using MCPs of standard glass composition, of the internal conversion electrons from a thin gadolinium foil. We present the first measurements of the detection efficiency, pulse height resolution and imaging properties of a pulse-counting MCP/Gd detector system.

  5. Calculated thermal performance of solar collectors based on measured weather data from 2001-2010

    DEFF Research Database (Denmark)

    Dragsted, Janne; Furbo, Simon; Andersen, Elsa

    2015-01-01

    This paper presents an investigation of the differences in modeled thermal performance of solar collectors when meteorological reference years are used as input and when mulit-year weather data is used as input. The investigation has shown that using the Danish reference year based on the period...... 1975-1990 will result in deviations of up to 39 % compared with thermal performance calculated with multi-year the measured weather data. For the newer local reference years based on the period 2001-2010 the maximum deviation becomes 25 %. The investigation further showed an increase in utilization...

  6. The design of a vehicle-mounted test system for the thermal performance of solar collector

    Science.gov (United States)

    Wen, S. R.; Wu, X. H.; Zhou, L.; Zheng, W.; Liu, L.; Yan, J. C.

    2016-08-01

    To increase the test efficiency of thermal performance of solar collector, a vehicle- mounted test system with high automation, simple operation, good mobility and stability is proposed in this paper. By refitting a medium bus, design of mechanical system and test loop, and using PC control technology, we implemented the vehicle-mounted system and realized effective integration between vehicle and test equipment. A number of tests have been done, and the results show that the vehicle-mounted test system has good parameters and performance and can be widely used to provide door-to-door testing services in the field of solar thermal application.

  7. EVALUATION OF EVACUATED TUBULAR SOLAR COLLECTORS FOR LARGE SDHW SYSTEMS AND COMBINED SPACE HEATING SYSTEMS

    DEFF Research Database (Denmark)

    Qin, Lin; Furbo, Simon

    1999-01-01

    . Based on thesemodels, the thermal performance of large solar domestic hot water (DHW) systems and combined domestichot water and space heating systems with the four evacuated tubular collectors was determined. To make acomparison with traditional flat-plate collectors, similar simulations were also...... carried out for systems with atypical flat-plate collector. The results show that the thermal advantage of evacuated tubular collectors variesgreatly from system to system, and increases with the solar fraction. Furthermore, the higher the operationtemperature of the collector in the system is......In the present study, detailed investigations on evacuated tubular solar collectors for large solarheating systems have been carried out. Four types of evacuated tubular solar collectors were used in theinvestigation. Based on laboratory tests, simulation models for the collectors were determined...

  8. Experimental investigations of the performance of a solar air collector with latent heat thermal storage integrated with the solar absorber

    Directory of Open Access Journals (Sweden)

    Hejcik J.

    2013-04-01

    Full Text Available The paper deals with experimental investigations of the performance of a solar air collector with latent heat thermal storage integrated with the solarabsorber. The main purpose of heat storage in solar thermal systems is to store heat when the supply of solar heat exceeds demand and release it when otherwise. A number of heat storage materials can be used for this purpose; the phase change materials among them. Short-term latent heat thermal storage integrated with the solar absorber can stabilize the air temperature at the outlet of the collector on cloudy days when solar radiation intensity incident on a solar collector fluctuates significantly. Two experimental front-and-back pass solar air collectors of the same dimensions have been built for the experimental investigations. One collector had a “conventional” solar absorber made of a metal sheet while the solar absorber of the other collector consisted of containers filled with organic phase change material. The experimental collectors were positioned side by side during the investigations to ensure the same operating conditions (incident solar radiation, outdoor temperature.

  9. Nanofluid Types, Their Synthesis, Properties and Incorporation in Direct Solar Thermal Collectors: A Review

    Science.gov (United States)

    Chamsa-ard, Wisut; Brundavanam, Sridevi; Fung, Chun Che; Fawcett, Derek; Poinern, Gerrard

    2017-01-01

    The global demand for energy is increasing and the detrimental consequences of rising greenhouse gas emissions, global warming and environmental degradation present major challenges. Solar energy offers a clean and viable renewable energy source with the potential to alleviate the detrimental consequences normally associated with fossil fuel-based energy generation. However, there are two inherent problems associated with conventional solar thermal energy conversion systems. The first involves low thermal conductivity values of heat transfer fluids, and the second involves the poor optical properties of many absorbers and their coating. Hence, there is an imperative need to improve both thermal and optical properties of current solar conversion systems. Direct solar thermal absorption collectors incorporating a nanofluid offers the opportunity to achieve significant improvements in both optical and thermal performance. Since nanofluids offer much greater heat absorbing and heat transfer properties compared to traditional working fluids. The review summarizes current research in this innovative field. It discusses direct solar absorber collectors and methods for improving their performance. This is followed by a discussion of the various types of nanofluids available and the synthesis techniques used to manufacture them. In closing, a brief discussion of nanofluid property modelling is also presented. PMID:28561802

  10. Evaluation of Single-Pass Photovoltaic-Thermal Air Collector with Rectangle Tunnel Absorber

    Directory of Open Access Journals (Sweden)

    Goh L. Jin

    2010-01-01

    Full Text Available Problem statement: Photovoltaic solar cell generate electric by receiving sun light or solar irradiance. But solar cell received heat from solar irradiance as well and this will reduced the efficiency of the solar cell. The heat trap at the solar photovoltaic panel become waste energy. Approach: The solution for this was by adding a cooling system to the photovoltaic panel. The purpose of this study was to cool the solar cell in order to increase its electrical efficiency and also to produce heat energy in the form of hot air. Hot air can be used for drying applications. A single pass PVT with rectangle tunnel absorber has been developed. The rectangle tunnel acted as an absorber and was located at the back side of a standard photovoltaic panel. The dimension of the photovoltaic panel was 120×53 cm. The size of the rectangle tunnel was 27 units of tunnel bar with the size of 1.2×2.5×120 cm (width×tall×length and 12 units with 1.2×2.5×105.3 cm (width×tall×length. The rectangle tunnel was connected in parallel. The PVT collector has been tested using a solar simulator. Results: Electrical efficiency increased when the solar cell was cool by air flow. Solar photovoltaic thermal collector with rectangle tunnel absorber has better electrical and thermal efficiency compared to solar collector without rectangle tunnel absorber. Photovoltaic, thermal and combined photovoltaic thermal efficiency of 10.02, 54.70 and 64.72% at solar irradiance of 817.4 W m-2, mass flow rate of 0.0287 kg sec-1 at ambiant temperature of 25°C respectively has been obtained. Conclusion: The hybrid photovoltaic and thermal with rectangle tunnel as heat absorber shows higher performance compared to conventional PV/T system.

  11. 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.

  12. 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

  13. 新型平板太阳能PV/T空气集热器传热特性的数值研究%Numerical Simulation of Thermal Performance of a New Type of Flat-Plate Solar PV/T Air Collector

    Institute of Scientific and Technical Information of China (English)

    孙健; 徐银文; 黄章峰; 李杰

    2015-01-01

    文中设计了一款新型PV/T一体化空气集热器,建立了新型PV/T空气系统内部传热过程的一维非稳态数学模型,并利用差分法对模型进行了数值计算。根据计算结果对一体化系统的性能及影响因素进行了分析。结果表明:在一定的光照强度下,随着空气质量流量增加,电池板温度Tp逐渐下降,空气温升逐渐降低;而热效率、光电转化效率、联合效率随空气流量的增加有所升高。模型的建立为高性能太阳能PV/T一体化空气集热器的优化设计提供较好理论依据。%In this paper, a new type of integrated solar PV/T air collector is designed. A one-dimensional unsteady mathematical model is developed, the internal heat transfer process is calculated by ifnite difference approach. The performance of PV/T solar air collector is predicted under different parameters and conditions. Results indicate that the temperature of solar cell and outlet air decrease with the increase of air mass lfow rate under the same incident solar intensity. Then, the thermal efifciency, electrical efifciency and total efifciency of PV/T system increase with the rising of the inlet air mass lfow rate. The models provide valuable theoretical basis for the optimal design of high-performance solar PV/T integrated air system.

  14. A self-tractable solar collector

    Science.gov (United States)

    Abdulhadi, M.; Ghorayeb, F.

    2006-06-01

    An analytical experimental investigation into the thermal performance of a tubeless hemispherical (a spherical cap) solar collector for use in heating and cooling purposes is presented. The receiver plate surface temperature was estimated at the prevailing steady-state conditions from the energy balance equation on the absorber plate. From the experimental analytical investigation, the present collector was found to be much more efficient than a flat-plate collector. Fluid outlet temperatures over 95°C could be provided on mid clear shining sunny days. Remembering the easiness of building a complex of such a collector, it follows that plenty of residential and industrial implementations, mostly in heating and cooling refrigeration absorption cycles, could be undertaken.

  15. 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...... 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. It is important to characterize microclimatic conditions in the collector, and at the Department of Buildings and Energy work is carried out with the improvement of a computer model. As a tool the computer model will be useful in developing guidelines to achieve the most favourable...

  16. 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...

  17. 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

    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...... 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...

  18. NUMERICAL SIMULATION OF THE AIR FLOW AROUND THE ARRAYS OF SOLAR COLLECTORS

    Directory of Open Access Journals (Sweden)

    Vukman V Bakić

    2011-01-01

    Full Text Available This paper deals with the numerical simulation of air around the arrays of flat plate collectors and determination of the flow field, which should provide a basis for estimating a convective heat losses, a parameter which influences their working characteristics. Heat losses are the result of the reflection on the glass, conductive losses at the collector's absorber plate, radiation of the absorber plate and convective losses on the glass. Wind velocity in the vicinity of the absorber plate depends on its position in the arrays of collectors. Results obtained in the numerical simulation of flow around collectors were used as boundary conditions in modeling of thermal-hydraulic processes inside the solar collector. A method for coupling thermal-hydraulic processes inside the collector with heat transfer from plate to tube bundle was developed, in order to find out the distribution of the temperature of the absorber plate and the efficiency of the flat plate collectors. Analyses of flow around arrays of collectors are preformed with RNG k - ε model. Three values for free-stream velocity were analysed, i.e. 1 m/s, 5 m/s and 10 m/s, as well as two values for the angle between the ground and the collector (20° and 40°. Heat transfer coefficient was determined from the theory of boundary layer. Heat transfer inside the plate cavity was analyzed assuming constant intensity of radiation.

  19. Deformation and fracture of a plate under thermal shock

    Energy Technology Data Exchange (ETDEWEB)

    Aptukov, V.N.; Pozdeev, A.A.

    1986-01-01

    The wave processes associated with thermal shock give rise to cumulative tensile stresses whose magnitude and location are determined by the plate geometry, the heating region, and the spatial distribution of the heat sources. Here, the wave processes, damage accumulation, and the development of macrofracture zones during thermal shock are analyzed using a two-dimensional axisymmetric formulation. The evolution of macrocracks during thermal shock in a plate, a cylinder, and a partially heated plate is shown graphically. 14 references.

  20. The multiple layer solar collector

    Science.gov (United States)

    Kenna, J. P.

    1983-01-01

    An analytical model is developed for obtaining numerical solutions for differential equations describing the performance of separate layers in a multiple layer solar collector. The configurations comprises heat transfer fluid entering at the top of the collector and travelling down through several layers. A black absorber plate prevents reemission of thermal radiation. The overall performance is shown to depend on the number of layers, the heat transfer coefficient across each layer, and the absorption properties of the working fluid. It is found that the multiple layer system has a performance inferior to that of flat plate selective surface collectors. Air gaps insulating adjacent layers do not raise the efficiency enough to overcome the relative deficiency.

  1. PR NF EN 12975-1 Thermal solar systems and components - collectors - Part. 1: general requirements; Installations solaires thermiques et leurs composants. Capteurs solaires. Partie 1: exigences generales

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-08-01

    The document specifies requirements on durability (including mechanical strength), reliability and safety for liquid heating solar collectors. It also includes provisions for evaluation of conformity to these requirements. It is not applicable to those collectors in which the thermal storage unit is an integral part of the collector to such an extent, that the collection process cannot be separated from the storage process for the purpose of making measurements of those two processes. It is not applicable to tracking concentrating solar collectors. (author)

  2. Design, simulation and optimization of a solar dish collector with spiral-coil thermal absorber

    Directory of Open Access Journals (Sweden)

    Pavlović Saša R.

    2016-01-01

    Full Text Available The efficient conversion of solar radiation into heat at high temperature levels requires the use of concentrating solar collectors. The goal of this paper is to present the optical and the thermal analysis of a parabolic dish concentrator with a spiral coil receiver. The parabolic dish reflector consists of 11 curvilinear trapezoidal reflective petals constructed by PMMA with silvered mirror layer and has a diameter of 3.8 m, while its focal distance is 2.26m. This collector is designed with commercial software SolidWorks and simulated, optically and thermally in its Flow Simulation Studio. The optical analysis proved that the ideal position of the absorber is at 2.1m from the reflector in order to maximize the optical efficiency and to create a relative uniform heat flux over the absorber. In thermal part of the analysis, the energetic efficiency was calculated approximately 65%, while the exergetic efficiency is varied from 4% to 15% according to the water inlet temperature. Moreover, other important parameters as the heat flux and temperature distribution over the absorber are presented. The pressure drop of the absorber coil is calculated at 0.07bar, an acceptable value.

  3. Thermal efficiency of low cost solar collectors - CSBC; Eficiencia termica de coletores solares de baixo custo - CSBC

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Renato C.; Shiota, Robson T.; Mello, Samuel F.; Assis Junior, Valdir; Bartoli, Julio R. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Faculdade de Engenharia Quimica. Dept. de Tecnologia de Polimeros

    2006-07-01

    The thermal performance of a low cost flat panel solar collector was measured. This Low Cost Solar Collector is a novel concept for water heating using only thermoplastics materials, used on building: ceiling and tubes made of unplasticized PVC, but without transparent cover. The top side of the UPVC panel was black painted to be the solar radiation absorber surface. Prototypes were installed on two charity houses around Campinas and at the FEQ campus, being used without any trouble for one year. The thermal efficiency analysis followed ABNT NBR 10184 standard at the Green-Solar Laboratory, Brazilian Centre for Development of Solar Thermal Energy, PUC-Minas. It was measured a thermal efficiency of 67%, compared to the 75% usually found on conventional solar collectors made of copper tubes and with glass cover. (author)

  4. DEVELOPMENT OF A MATHEMATICAL MODEL OF INSTALLATION OF SELF-CONTAINED HEATING BASED ON SOLAR THERMAL COLLECTOR

    OpenAIRE

    Kartashev, Alexander; Safonov, Evgeniy; Kartasheva, Marina

    2011-01-01

    The mathematical model describing the operation of the installation of selfcontained heating and hot water supply based on solar thermal collector with the system of accumulation of heat energy, monitoring and control of thermal conditions of building is developed. Modeling of operation of the installation in different conditions is realized.

  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...... temperature, condensation) is investigated under different operating conditions (day and night). Under some conditions condensation might occur and heat gains could represent up to 55% of the total unglazed collector energy by night. Two TRNSYS collector models including condensation heat gains are also...... 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. Thermal and mechanical modelling of convergent plate margins

    NARCIS (Netherlands)

    van den Beukel, P.J.

    1990-01-01

    In this thesis, the thermal and mechanical structure of convergent plate margins will be investigated by means of numerical modelling. In addition, we will discuss the implications of modelling results for geological processes such as metamorphism or the break-up of a plate at a convergent plate

  7. Thermal and mechanical modelling of convergent plate margins

    NARCIS (Netherlands)

    van den Beukel, P.J.

    1990-01-01

    In this thesis, the thermal and mechanical structure of convergent plate margins will be investigated by means of numerical modelling. In addition, we will discuss the implications of modelling results for geological processes such as metamorphism or the break-up of a plate at a convergent plate mar

  8. Thermal and mechanical modelling of convergent plate margins

    NARCIS (Netherlands)

    Beukel, P.J. van den

    1990-01-01

    In this thesis, the thermal and mechanical structure of convergent plate margins will be investigated by means of numerical modelling. In addition, we will discuss the implications of modelling results for geological processes such as metamorphism or the break-up of a plate at a convergent plate mar

  9. PV/T集热器优化设计及实验%Optimization design and experimental study on collector of photovoltaic/thermal

    Institute of Scientific and Technical Information of China (English)

    梁子伟; 简林桦; 闫金州; 关欣

    2016-01-01

    The photovoltaic/thermal(PV/T) collector is a critical component of the photovoltaic thermal system. Performance quality directly decides high or low of comprehensive utilization of solar energy. Therefore,the design of the PV/T collector has an important role on research in the performance of the photovoltaic solar-thermal system. In this paper,the analysis structure and heat resistance of the PV/T collector,simulation of the thermal performance of the PV/T collector in aluminum tube plate under 75 kinds of working conditions,including irradiance types,structure size and flow conditions by using the Fluent software,and optimal design for the PV/T collector,according to the result of design to build the test rig,the collection efficiency and power efficiency of PV/T collector were studied. The results showed that the better cooling water flow rate(Q=0.008kg/s) and area ratio(D/W=0.4) of the collector were obtained. With the increase of the normalized temperature difference,the photoelectric efficiency and the collection efficiency of PV/T collector decreased. The maximum error of the predicted values and experimental values of the photoelectric efficiency was 22.5 percent. The average collection efficiency is 0.63. The county thermal efficiency reaches 0.75.%光伏/光热(photovoltaic/thermal collector,PV/T)集热器是光伏光热系统的关键部件,其性能好坏直接决定着太阳能综合利用率的高低,因此 PV/T 集热器的设计对光伏光热系统的性能研究有着重要的作用。本文对PV/T 集热器结构和传热热阻进行了分析,采用 Fluent 软件对不同的辐照度、结构尺寸和流量共75种工况下的PV/T集热器的热性能进行了数值模拟;并对PV/T集热器进行了优化设计,根据设计结果搭建了试验台,对PV/T集热器的集热效率与发电效率进行了研究。研究结果表明:集热器内最佳冷却水流量为0.008kg/s,光伏电池和集热面积最佳比 D/W=0.4。

  10. The Effect of the Angle of Inclination on the Efficiency in a Medium-Temperature Flat Plate Solar Collector

    Directory of Open Access Journals (Sweden)

    Orlando Montoya-Marquez

    2017-01-01

    Full Text Available In this experimental work, the effects of the inclination angle β and the (Ti − Ta/G on the efficiency and the UL-value were investigated on a medium-temperature flat plate solar collector. The experiments were based on steady-state energy balance, by heat flow calorimetry at indoor conditions and considering the standard American National Standard Institute/American Society of Heating Refrigerating and Air Conditioning Engineers (ANSI/ASHRAE 93-2010. The solar radiation was emulated by the Joule effect using a proportional integral derivative (PID control considering two conditions of the absorber temperature, Case 1: (To − Ti > 0, and Case 2: (To − Ti = 0. The inclination angles were 0°–90° and the (Ti − Ta/G were 0.044–0.083 m2·°C/W and 0.124–0.235 for Case 1 and Case 2, respectively. The variations of β and (Ti − Ta/G cause efficiency changes up to 0.37–0.45 (21.6% and 0.31–0.45 (45.0%, respectively, for Case 1. Also, the UL(β reached changes up to 10.1–12.0 W/m2·°C (19.2% and 8.4–12.0 W/m2·°C (41.7%, respectively, for Case 1. The most significant changes of UL(β/UL(90° vs. β were 8.0% at the horizontal position for Case 1, while for Case 2, the maximum change was 1.8% only. Therefore, the changes of the inclination angle cause significant variations of the convective flow patterns within the collector, which leads to considerable variation of the collector efficiency and its UL value.

  11. 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.

  12. Nitrite/nitrate detection in serum based on dual-plate generator-collector currents in a microtrench.

    Science.gov (United States)

    Gross, Andrew J; Holmes, Stephanie; Dale, Sara E C; Smallwood, Miranda J; Green, Stephen J; Winlove, C Peter; Benjamin, Nigel; Winyard, Paul G; Marken, Frank

    2015-01-01

    A dual-electrode sensor is developed for rapid detection of nitrite/nitrate at micromolar levels in phosphate buffer media and in dilute horse serum without additional sample pre-treatment. A generator-collector configuration is employed so that on one electrode nitrate is reduced to nitrite and on the second electrode nitrite is oxidised back to nitrate. The resulting redox cycle gives rise to a specific and enhanced current signal which is exploited for sensitive and reliable measurement of nitrite/nitrate in the presence of oxygen. The electrode design is based on a dual-plate microtrench (approximately 15 µm inter-electrode gap) fabricated from gold-coated glass and with a nano-silver catalyst for the reduction of nitrate. Fine tuning of the phosphate buffer pH is crucial for maximising collector current signals whilst minimising unwanted gold surface oxidation. A limit of detection of 24 μM nitrate and a linear concentration range of 200-1400 μM is reported for the microtrench sensor in phosphate buffer and dilute horse serum. Relative standard deviations for repeat measurements were in the range 1.8-6.9% (n=3) indicating good repeatability in both aqueous and biological media. Preliminary method validation against the standard chemiluminescence method used in medical laboratories is reported for nitrate analysis in serum.

  13. German co-operation in the IEA WG 'Materials in Solar Thermal Collectors'. Final report; Deutsche Mitarbeit in der IEA - Arbeitsgruppe 'Materials in Solar Thermal Collectors'. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Koehl, M.; Heck, M.; Kuebler, V.; Steinhart, J.

    2000-07-01

    To effectively select, use and maintain a material in a given application, its degradation under service conditions must be predicted prior to use. Preferably, the durability of the material should be expressed quantitatively in terms of an expected service life. Durability in this case is the ability of a material to withstand deterioration caused by all external factors in the environment, which may influence the performance of the material under service conditions. Service life is defined as the period of time after installation during which specific material properties important for the performance of the material meet or exceed minimum acceptable values. The present recommended qualification procedure for solar absorber surface durability is based on the conduct of a series of short term durability tests. During a test the optical performance of absorber surface tested is determined by measuring its solar absorptance and thermal emittance. From the loss in optical performance of absorber surface, its failure time in the test performed is assessed and compared with the shortest acceptable failure time set by the design service life of absorber. Design service life, performance requirement defining failure time in terms of loss in optical performance, classification of type and levels of environmental stress are set under the assumption, that the absorber surface tested will be installed in a flat plate solar collector for use in domestic hot water systems. (orig.)

  14. 混合工质太阳能平板热管集热器的传热性能%Heat Transfer Performance ofthe Flat Plate Heat Pipe Solar Collector with Mixture Working Fluid

    Institute of Scientific and Technical Information of China (English)

    杜胜华; 苏海鹏

    2014-01-01

    介绍了平板热管的基本结构与原理,在分析乙二醇及其混合工质的热物理学特性的基础上,建立平板热管的物理与数学模型。采用数值计算模拟方法,分析了混合工质平板热管集热器的传热性能,研究了集热器的效率、温升和启动性能随工作时间的变化规律。研究表明,乙二醇水混合工质平板热管集热器适宜于低温寒冷地区,具有较高的集热性能。%The basic structure and principle of flat plate heat pipe were introduced based on thermal physics characteristics analysis of ethylene glycol and mixtures , physical and mathematical models of flat plate heat pipe were established.By the numerical simulation method , the heat transfer performance of the flat heat pipe heat collector with mixture working fluid was analyzed , and the efficiency , temperature collector up and starting performance by time were studied.It showed that flat heat pipe heat collector with ethylene glycol water mixture was suitable for cold area , and the heat collecting performance was high.

  15. Fresnel-collectors in hybrid solar thermal power plants with high solar shares

    Energy Technology Data Exchange (ETDEWEB)

    Lerchenmueller, H.; Mertins, M.; Morin, G. [Fraunhofer Inst. for Solar Energy Systems, Freiburg (Germany); Haeberle, A. [PSE GmbH, Solar Info Center, Freiburg (Germany); Bockamp, S.; Ewert, M.; Fruth, M.; Griestop, T. [E.ON Energie AG, Muenchen (Germany); Dersch, J. [Deutsches Zentrum fuer Luft- und Raumfahrt, Koeln (Germany)

    2004-07-01

    The use of Fresnel-Collectors in power plant configurations with low or zero CO2-emission has been analysed in this paper. Both, the solar-biomass hybrid plant and the solar-gas hybrid plant are very promising concepts with respect to technical, economical and ecological aspects. The hybrid operation would be very useful to handle the fluctuating solar resource and facilitate operation. Depending on feed in tariffs the hybridisation of a solar thermal power plant with biomass or with small shares of natural gas can be economically very interesting. The ecological advantage of a solar-biomass power plant is evident, since it would be a zero CO2- emission plant. Beyond that biomass is a limited source, especially in regions with high solar irradiance. The herein examined gas hybrid variants are by far more favourable than Integrated Solar Combined Cycle Systems (ISCCS), which have been previously examined. Since much higher solar shares can be reached this is a forward-looking technology. Furthermore the solar field does not act as a disturbing factor as opposed to the ISCCS concept, where the efficiency of the sophisticated CC system is reduced due to suboptimal dimensioning of components. In other words: It is better to build the suggested hybrid plant with low gas share and CC plants instead of ISCCS plants. The resulting solar levelised electricity costs of both options are approximately the same. The calculated levelised electricity costs for the examined configurations of between 11 and 13 ct/kWh are very promising results. The calculations were made based on cost assumptions for the collector of 130 Euro/m{sup 2} which seems realistic not for the first project but for the third plant. As a next step in the commercialisation of the Fresnel-technology demonstration and test collectors must be built, such as by the Australian company Solar Heat and Power, to validate the technical and economic assumptions. (orig.)

  16. 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

  17. 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

  18. 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 fou

  19. 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 decrea

  20. Numerical Investigation of Nanofluid-based Solar Collectors

    Science.gov (United States)

    Karami, M.; Raisee, M.; Delfani, S.

    2014-08-01

    Solar thermal collectors are applicable in the water heating or space conditioning systems. Due to the low efficiency of the conventional collectors, some suggestions have been presented for improvement in the collector efficiency. Adding nanoparticles to the working fluid in direct absorption solar collector, which has been recently proposed, leads to improvement in the working fluid thermal and optical properties such as thermal conductivity and absorption coefficient. This results certainly in collector efficiency enhancement. In this paper, the radiative transfer and energy equations are numerically solved. Due to laminar and fully developed flow in the collector, the velocity profile is assumed to be parabolic. As can be observed from the results, outlet temperature of collector is lower than that obtained using uniform velocity profile. Furthermore, a suspension of carbon nanohorns in the water is used as the working fluid in the model and its effect on the collector efficiency is investigated. It was found that the presence of carbon nanohorns increases the collector efficiency by about 17% compared to a conventional flat-plate collector. In comparison with the mixture of water and aluminium nanoparticles, a quite similar efficiency is obtained using very lower concentration of carbon nanohorns in the water.

  1. Thermal Efficiency of Power Module “Boiler with Solar Collectors as Additional Heat Source” For Combined Heat Supply System

    Directory of Open Access Journals (Sweden)

    Denysova A.E.

    2015-04-01

    Full Text Available The purpose of work is to increase the efficiency of the combined heat supply system with solar collectors as additional thermal generators. In order to optimize the parameters of combined heat supply system the mathematical modeling of thermal processes in multi module solar collectors as additional thermal generators for preheating of the water for boiler have been done. The method of calculation of multi-module solar collectors working with forced circulation for various configurations of hydraulic connection of solar collector modules as the new result of our work have been proposed. The results of numerical simulation of thermal efficiency of solar heat source for boiler of combined heat supply system with the account of design features of the circuit; regime parameters of thermal generators that allow establishing rational conditions of its functioning have been worked out. The conditions of functioning that provide required temperature of heat carrier incoming to boiler and value of flow rate at which the slippage of heat carrier is not possible for different hydraulic circuits of solar modules have been established.

  2. 微热管阵列平板太阳能集热器中空保温层厚度优化%Optimization of hollow insulation layer for flat plate solar collector based on micro heat pipe array

    Institute of Scientific and Technical Information of China (English)

    邓月超; 赵耀华; 全贞花; 刘中良

    2015-01-01

    In this paper, a three-dimensional CFD numerical model of heat transfer and fluid flow was developed to simulate the thermal performance of the novel flat plate solar collector based on a micro heat pipe array to provide a theoretical basis for the structure improvement and optimization of the collector. The simulation of the novel collector with water flow included the CFD modeling of solar irradiation and the modes of mixed convection and radiation heat transfer between the absorber plate and glass cover, as well as the heat transfer in the circulating water inside the heat exchanger and conduction of the insulation. The fluid flow and heat transfer in the computational domain satisfied the continuity equation, the momentum equation, and the energy equation. The standardk-ε two-equation turbulence model was used in this paper. In order to predict the direct illumination energy source that results from incident solar radiation and the radiation field inside the collector, the discrete ordinate radiation model with a solar ray-tracing model was used. A commercial computational fluid dynamics program (Fluent 6.3 CFD software) was used to solve the coupled fluid flow, heat transfer, and the radiation equation. The solver used is the segregated solver. Body Force Weighted was selected as the discretization method for pressure, and the SIMPLE algorithm was used to resolve the coupling between pressure and velocity. The discretization methods for the solving of momentum, energy, radiation, and turbulence were second order upwind. The thermal performance could be achieved by simulation results under different conditions. Then, the experimental and numerical results were compared to validate the prediction of the CFD model. The results showed that the numerical results of the thermal efficiency of the novel collector were in reasonable agreement with the experimental data. The validated CFD model was used to analyze the properties of the insulation layer. First, the

  3. Experimental Investigation of Single Pass, Double Duct Photovoltaic Thermal (PV/T Air Collector with CPC and Fins

    Directory of Open Access Journals (Sweden)

    M. E.A. Alfegi

    2008-01-01

    Full Text Available 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. An experimental investigation of a solar air heater with photovoltaic cell located at the absorber with compound parabolic collector (CPC and fins have been developed and tested. 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 400 W/m2 showed that the combined pv/t efficiency is increasing from 27.50 % to 40.044 % at mass flow rates various from 0.0316 to 0.09 kg-1 s.

  4. The Influence of Different Absorbed Coatings on Thermal Effect of Prefabricated Solar Collector Panels

    OpenAIRE

    Wang Qi; Yang Liquan; Yu Miao; Li Song

    2016-01-01

    Prefabricated solar collector panels is a kind of new permeability structure of collector panels. For this test, we adopt a certain proportion of copper oxide, magnesium oxide and iron oxide to enamel paint as absorbed panel coating and make two kinds of collector panels for different forms of color by dark green coating and black coating. By the methods of comparison, the two kinds of panel collector efficiency and heat loss coefficient UL were tested. The results showed that there was a sli...

  5. Performance evaluation of a liquid solar collector

    Science.gov (United States)

    1979-01-01

    Report describes thermal performance and structural-load tests on commercial single glazed flat-plate solar collector with gross area of 63.5 sq ft that uses water as heat-transfer medium. Report documents test instrumentation and procedures and presents data as tables and graphs. Results are analyzed by standard data-reduction methods.

  6. Performance evaluation of an air solar collector

    Science.gov (United States)

    1979-01-01

    Indoor tests on signal-glazed flat-plate collector are described in report. Marhsall Space Flight Center solar simulator is used to make tests. Test included evaluations on thermal performance under various combinations of flow rate, incident flux, inlet temperature, and wind speed. Results are presented in graph/table form.

  7. Possible high absorptance and low emittance selective surface for high temperature solar thermal collectors.

    Science.gov (United States)

    Zhang, Q C; Kelly, J C; Mills, D R

    1991-05-01

    Optical reflectivity measurements show that the reflectivity of Ge is dramatically reduced in the wavelength 0.3-1.4-microm range after high dose oxygen ion implantation. To explain such greatly reduced reflectivity, a model has been developed for the reflectivity of high dose oxygen implanted germanium. Our experimentally measured and calculated reflectivities show that, for a layered structure consisting of a Ge and GeO(2) mixture on Ge on GeO(2) on a Cu substrate, a low reflectivity of 0-10% in the solar spectrum is obtained, together with a high reflectivity approximately 100% in the 1.7-25-microm wavelength range. This is close to that of an ideal selective surface for solar energy thermal collectors operating at high temperatures from 300 to 500 degrees C.

  8. Comparative evaluation of distributed-collector solar thermal electric power plants

    Science.gov (United States)

    Fujita, T.; El Gabalawi, N.; Herrera, G. G.; Caputo, R. S.

    1978-01-01

    Distributed-collector solar thermal-electric power plants are compared by projecting power plant economics of selected systems to the 1990-2000 timeframe. The approach taken is to evaluate the performance of the selected systems under the same weather conditions. Capital and operational costs are estimated for each system. Energy costs are calculated for different plant sizes based on the plant performance and the corresponding capital and maintenance costs. Optimum systems are then determined as the systems with the minimum energy costs for a given load factor. The optimum system is comprised of the best combination of subsystems which give the minimum energy cost for every plant size. Sensitivity analysis is done around the optimum point for various plant parameters.

  9. Construction and thermal efficiency test of 145m and 165m SpaceTube large-aperture parabolic trough collector prototypes

    Science.gov (United States)

    Rubia, Salvador Valenzuela; Schramm, Markus; Yildiz, Hülya; Marcotte, Patrick; Casero, David Martín; Magee, John Sebastian

    2016-05-01

    During 2013-2014 two prototype SpaceTube® 8.2 parabolic trough collector [1] were built, optically tested, and interconnected into an existing parabolic trough thermal testing loop at Abengoa's Solucar Platform in Spain. After this startup process more than 500 hours of testing at nominal operating conditions (393 °C maximum temperature and 40 bar maximum pressure) were accumulated, allowing verification of the real-world thermal performance against model predictions. Measured performances of both collectors met the optical performance target and no significant optical or assembly deficiency was found, resulting in verification of the collector(s) as ready to commercialize.

  10. Theoretical and experimental investigations of Chinese evacuated tubular solar collectors

    DEFF Research Database (Denmark)

    Qin, Lin; Furbo, Simon

    1999-01-01

    Four different marketed Chinese evacuated tubular solar collectors have been investigated both theoretically and experimentally. The advantages of the investigated solar collectors compared to normal flat plate collectors were elucidated.......Four different marketed Chinese evacuated tubular solar collectors have been investigated both theoretically and experimentally. The advantages of the investigated solar collectors compared to normal flat plate collectors were elucidated....

  11. Prediction of Thermal and Elastic Properties of Honeycomb Sandwich Plate for Analysis of Thermal Deformation

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Seok Min; Lee, Jang Il; Byun, Jae Ki; Choi, Young Don [Korea Univ., Seoul (Korea, Republic of)

    2014-04-15

    Thermal problems that are directly related to the lifetime of an electronic device are becoming increasingly important owing to the miniaturization of electronic devices. To solve thermal problems, it is essential to study thermal stability through thermal diffusion and insulation. A honeycomb sandwich plate has anisotropic thermal conductivity. To analyze the thermal deformation and temperature distribution of a system that employs a honeycomb sandwich plate, the thermal and elastic properties need to be determined. In this study, the thermal and elastic properties of a honeycomb sandwich plate, such as thermal conductivity, coefficient of thermal expansion, elastic modulus, Poisson's ratio, and shear modulus, are predicted. The properties of a honeycomb sandwich plate vary according to the hexagon size, thickness, and material properties.

  12. Quality Assurance of Process Free Thermal Plates

    Directory of Open Access Journals (Sweden)

    Thomas Hoffmann-Walbeck

    2015-09-01

    Full Text Available In this paper a method for manual processing of process free printing plates is defined which ensures reproducible results. This decoating procedure can help print service providers with certain quality checks (like linearization that are otherwise more expensive or even not feasible altogether for such plates. This method holds for quality assurance only and is not suitable for the actual production.

  13. 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.

  14. Optimization Design of Thermal Conduction Enhanced PCM Plates for Simulating the Infrared Signature of Steel Plate

    Institute of Scientific and Technical Information of China (English)

    YE Hong; JIANG Li-feng

    2008-01-01

    Phase change material (PCM) can be used to prepare the infrared false targets for realizing all-weather passive infrared decoy, but its low thermal conductivity is a great blockage to the simulation of the infrared signature of thick metal plates. For that reason, a method of simulating the infrared signature of thick steel plates by thermal conduction enhanced PCM, including the aluminum fins, is proposed. A physical and mathematic model is set up, and the infrared signature simulation of thick steel plate is investigated numerically. The effects of the distribution density and thickness of fins and the thickness of PCM plate on the simulation results are discussed, and the reasonable construction parameters of PCM plates used to simulate the steel plates of different thickness are obtained.

  15. Development and life cycle analysis of double slope active solar still with flat plate collector

    Directory of Open Access Journals (Sweden)

    A.K. Sethi

    2014-02-01

    Full Text Available Potable water is an essential ingredient of socio-economic development and economic growth. Often water sources are brackish (i.e. contain dissolved salts and/or contain harmful bacteria and therefore cannot be used for drinking. In addition, there are many coastal locations where seawater is abundant but potable water is not available. This study is focused on a development of solar still with flat plat collector for water desalination considered for small scale applications at remote locations where only saline water is available. In this paper the cost of distilled water per kg has been calculated by using the concept of life cycle cost analysis. The pay back periods for different conditions of the distribution of distilled water, namely at the cost it is produced and at the selling price on market rate have been evaluated. The cost of water per kg is minimum Rs. 0.59, when the interest rate and the lifetime of solar still are taken as 4% and 50 years respectively. The lowest payback time 1.23 years is obtained when the selling price of water Rs. 10 per kg.

  16. 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...... collectors could raise flexibility in the control strategy of the plant. The TRNSYS-Genopt model is based on individually validated component models and collector parameters from experiments. Optimization of the cost performance of the plant has been conducted in this paper. The simulation model remains...... to be validated with annual measured data from the plant....

  17. Central Receiver Solar Thermal Power System, Phase 1. CDRL Item 2. Pilot Plant preliminary design report. Volume III, Book 1. Collector subsystem

    Energy Technology Data Exchange (ETDEWEB)

    Hallet, Jr., R. W.; Gervais, R. L.

    1977-10-01

    The central receiver system consists of a field of heliostats, a central receiver, a thermal storage unit, an electrical power generation system, and balance of plant. This volume discusses the collector field geometry, requirements and configuration. The development of the collector system and subsystems are discussed and the selection rationale outlined. System safety and availability are covered. Finally, the plans for collector portion of the central receiver system are reviewed.

  18. CONC/11: A computer program for calculating the performance of dish-type solar thermal collectors and power systems

    Science.gov (United States)

    Jaffe, L. D.

    1984-01-01

    The CONC/11 computer program designed for calculating the performance of dish-type solar thermal collectors and power systems is discussed. This program is intended to aid the system or collector designer in evaluating the performance to be expected with possible design alternatives. From design or test data on the characteristics of the various subsystems, CONC/11 calculates the efficiencies of the collector and the overall power system as functions of the receiver temperature for a specified insolation. If desired, CONC/11 will also determine the receiver aperture and the receiver temperature that will provide the highest efficiencies at a given insolation. The program handles both simple and compound concentrators. The CONC/11 is written in Athena Extended FORTRAN (similar to FORTRAN 77) to operate primarily in an interactive mode on a Sperry 1100/81 computer. It could also be used on many small computers. A user's manual is also provided for this program.

  19. CONC/11: a computer program for calculating the performance of dish-type solar thermal collectors and power systems

    Energy Technology Data Exchange (ETDEWEB)

    Jaffe, L. D.

    1984-02-15

    CONC/11 is a computer program designed for calculating the performance of dish-type solar thermal collectors and power systems. It is intended to aid the system or collector designer in evaluating the performance to be expected with possible design alternatives. From design or test data on the characteristics of the various subsystems, CONC/11 calculates the efficiencies of the collector and the overall power system as functions of the receiver temperature for a specified insolation. If desired, CONC/11 will also determine the receiver aperture and the receiver temperature that will provide the highest efficiencies at a given insolation. The program handles both simple and compound concentrators. CONC/11 is written in Athena Extended Fortran (similar to Fortran 77) to operate primarily in an interactive mode on a Sperry 1100/81 computer. It could also be used on many small computers.

  20. Recommendations for European solar collector test methods (Liquid heating collectors)

    Science.gov (United States)

    Derrick, A.; Gillett, W. B.

    Standardized testing formats, equipment, conditions, and tests defined as part of the solar flat plate collector testing program performed by the Commission of the European Communities are detailed. The work is a product of efforts at 20 laboratories, and alternative methods have been characterized for tailoring tests to particular locations and climatic conditions. The testing methods are intended for collectors using a liquid as the heat transfer medium. Procedures have been defined for examining steady state and transient performance, heat loss, thermal capacity, pressure drop, and anemometry. Instrumentation types and accuracies have been defined, and a standardized format for presentation of results has been developed. The tests are tailored for determining the durability of the flat plate systems under simulated solar radiation conditions.

  1. Thermal Analysis of Thin Plates Using the Finite Element Method

    Science.gov (United States)

    Er, G. K.; Iu, V. P.; Liu, X. L.

    2010-05-01

    The isotropic thermal plate is analyzed with finite element method. The solution procedure is presented. The elementary stiffness matrix and loading vector are derived rigorously with variation principle and the principle of minimum potential energy. Numerical results are obtained based on the derived equations and tested with available exact solutions. The problems in the finite element analysis are figured out. It is found that the finite element solutions can not converge as the number of elements increases around the corners of the plate. The derived equations presented in this paper are fundamental for our further study on more complicated thermal plate analysis.

  2. Thermally Induced Principal Parametric Resonance in Circular Plates

    Directory of Open Access Journals (Sweden)

    Ali H. Nayfeh

    2002-01-01

    Full Text Available We consider the problem of large-amplitude vibrations of a simply supported circular flat plate subjected to harmonically varying temperature fields arising from an external heat flux (aeroheating for example. The plate is modeled using the von Karman equations. We used the method of multiple scales to determine an approximate solution for the case in which the frequency of the thermal variations is approximately twice the fundamental natural frequency of the plate; that is, the case of principal parametric resonance. The results show that such thermal loads produce large-amplitude vibrations, with associated multi-valued responses and subcritical instabilities.

  3. Thermal performance and stress analyses of the cavity receiver tube in the parabolic trough solar collector

    Science.gov (United States)

    Cao, F.; Li, Y.; Wang, L.; Zhu, T. Y.

    2016-08-01

    A light ray tracing model and a heat transfer model were built to analyse the heat flux distribution and heat transfer in a 1m cavity receiver tube with Parabolic Trough Collectors as the concentrator. The numerical methods were used to simulate the thermal stress and deformation of the receiver tube. The temperature fields of the receiver tube and the thermal stress distribution in the steel tube at the cross section and along the fluid flowing direction were presented. It is obtained from this study that non-uniform heat flux distribution is absorbed at the receiver tube outer surface due to the structure of the cavity receiver tube. Temperature fields in the steel receiver tube at the inlet and the outlet match well with the incident solar radiation. An eccentric circle temperature gradient is observed at cross section of the outlet fluid. The equivalent stress is a complex result of solar heating flux, energy transfer inside the PTC and the fluid and steel characteristics. Highest deformation is 3.1mm at 0.82m. On increasing the fluid mass flow rate, higher fluid mass flow rate results in higher equivalent stress along the absorber tube.

  4. The Experimental Study of Plastic Plate Solar Collector%塑料太阳能平板集热器试验研究

    Institute of Scientific and Technical Information of China (English)

    李久锋; 陈观生; 张国庆

    2015-01-01

    According to the undemanding heating rate of heat-storage solar water heater, a new type of plastic plate solar collector was designed.Under the condition of intermittent forced circulation, test on the performance of this collector was carried out and instantaneous efficiency curves were obtained.As a result, the average daily collector efficiency is 51%~55% and the temperature of tank is 45.8~50.2 ℃, which serve as a reference for the application of plastic plate solar collector.%针对蓄热型太阳能热水器对升温速率要求不高的特点,提出并研制了一种新型塑料太阳能平板集热器.在间歇性强制循环条件下,对该集热器进行性能测试,获得了瞬时效率曲线.在试验条件下,该集热器的日平均效率为51%~55%,水箱温度为45.8~50.2℃,可以为塑料平板集热器的实际应用提供依据.

  5. Midtemperature solar systems test facility predictions for thermal performance based on test data: Solar kinetics T-600 solar collector with FEK 244 reflector surface

    Science.gov (United States)

    Harrison, T. D.

    1981-04-01

    A program to predict the performance and measure the characteristics of commercially available solar collectors with potential for use in industrial process heat and enhanced oil recovery applications is discussed. The thermal performance predictions for the Solar Kinetics T-600 solar line focusing parabolic trough collector are presented for three output temperatures at five cities in the US.

  6. Indoor test for thermal performance of the GE TC-100 liquid solar collector eight- and ten-tube configuration. [Marshall Space Flight Center solar simulator

    Science.gov (United States)

    1979-01-01

    The thermal performance of a liquid solar collector was tested in eight- and ten-tube configurations under simulated conditions. A time constant test and an incident angle modifier test were also conducted to determine the transient and incident angle effects on the collector. Performance loss with accessory covers is demonstrated. The gross collector area is about 17.4 ft sq without manifold and 19.1 ft sq with manifold. The collector weight is approximately 60 pounds empty and 75 pounds with manifold.

  7. Solar combisystems. A comparison between vacuum tube- and flat plate collectors using measurements and simulations; Solvaermda kombisystem. En jaemfoerelse mellan vakuumroer och plan solfaangare genom maetning och simulering

    Energy Technology Data Exchange (ETDEWEB)

    Kovacs, Peter; Pettersson, Ulrik

    2002-10-01

    Two solar combisystems were mounted side by side in an outdoor test facility and continuously operated during one year. The whole year, all relevant temperatures, flow rates and environment variables were thoroughly measured. The systems were identical apart from the collectors which were a 9 m{sup 2} vacuum tube and a 12.2 m{sup 2} selective flat plate collector. A simulated space heating and tap water load of approx. 25 MWh/a was applied to each system and auxiliary heat was charged to the stores from emulated pellet boilers. Additionally, the two collectors and the store was tested separately and the systems simulated according to the CTSS principle described in ENV 12977. The aim of the project was to determine solar fractions in a solar combisystem from real measurements and to compare the two different collector types from different points of view. On the basis of the validated simulation model, the results from the long term measurements could be generalized and eight different loads were simulated. The results showed that the vacuum tubes performed 45-60% better than the flat plate per m{sup 2} depending on the load applied. The solar fractions (assuming no losses from the boiler) varied from 11% for the measured systems to approx. 30 % in a house with 25 % of the original space heating load. During the heating season, the vacuum tubes occasionally performed much worse than the flat plate due to the fact that snow and frost melted away much quicker from the flat plate. For the use of vacuum tubes in snowy regions, vertical mounting should therefore be strongly recommended.

  8. Application of sintered plate dust collector in gold mines%烧结板除尘器在黄金矿山的应用

    Institute of Scientific and Technical Information of China (English)

    郑民; 轩慎英; 刘刚

    2016-01-01

    It is always difficult for gold mine to collect dust .Inner Mongolia Pacific Mining Corporation Limited first applies sintered plate dust collectors in the crashing stage during the second phase of expansion project .The sin-tered plate dust collector occupies less space and is reliable with good dust collection effect and lower vent gas concen -tration.The paper based on technical characteristics of dust collection process and performance test results focused on the technical and economical analysis of the application of sintered plate dust collector ,expecting to provide reference of the dust collection process for gold mines .%黄金生产中的除尘问题一直受到黄金矿山企业的关注.内蒙古太平矿业有限公司二期扩建项目首次在选矿厂破碎工段采用了烧结板除尘器,其设备占地面积小、运行可靠、除尘效果好、尾气质量浓度低于排放标准.该文结合除尘工艺技术特点以及设备性能测试结果,重点对烧结板除尘器的应用进行了技术与经济分析,以期为类似黄金矿山企业除尘工艺提供参考.

  9. Decosol Project : development of solar plate collectors of high efficiency and low cost for medium temperature application; Proyecto Decosol: Desarrollo de colectores solares planos de alta eficiencia ybajo coste para aplicaciones a mediana temperatura

    Energy Technology Data Exchange (ETDEWEB)

    Cadafalch, J.; Oliva, A.; Lavandeira, J. C.; Maestre, F.; Martinez, J. C.; Martin, J. R.; Hermo, R.

    2004-07-01

    Work that is currently being carried out by the authors in the framework of the project DECOSOL (Development of high efficiency and low cost flat plate collectors for medium temperature applications) is described in this paper. The goal of DECOSOL is to consolidate the results of previous R AND D projects conducted by the authors on the development of stagnation proof transparently insulated flat plate solar collectors prototypes, in order to end up with commercial products. (Author)

  10. 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.

  11. Enhancing the thermal conductivity of ethylene-vinyl acetate (EVA) in a photovoltaic thermal collector

    Science.gov (United States)

    Allan, J.; Pinder, H.; Dehouche, Z.

    2016-03-01

    Samples of Ethylene-Vinyl Acetate (EVA) were doped with particles of Boron Nitride (BN) in concentrations ranging from 0-60% w/w. Thermal conductivity was measured using a Differential Scanning Calorimetery (DSC) technique. The thermal conductivity of parent EVA was increased from 0.24W/m ṡ K to 0.80W/m ṡ K for the 60% w/w sample. Two PV laminates were made; one using the parent EVA the other using EVA doped with 50% BN. When exposed to a one directional heat flux the doped laminate was, on average, 6% cooler than the standard laminate. A finite difference model had good agreement with experimental results and showed that the use of 60% BN composite achieved a PV performance increase of 0.3% compared to the standard laminate.

  12. Enhancing the thermal conductivity of ethylene-vinyl acetate (EVA in a photovoltaic thermal collector

    Directory of Open Access Journals (Sweden)

    J. Allan

    2016-03-01

    Full Text Available Samples of Ethylene-Vinyl Acetate (EVA were doped with particles of Boron Nitride (BN in concentrations ranging from 0-60% w/w. Thermal conductivity was measured using a Differential Scanning Calorimetery (DSC technique. The thermal conductivity of parent EVA was increased from 0.24W/m ⋅ K to 0.80W/m ⋅ K for the 60% w/w sample. Two PV laminates were made; one using the parent EVA the other using EVA doped with 50% BN. When exposed to a one directional heat flux the doped laminate was, on average, 6% cooler than the standard laminate. A finite difference model had good agreement with experimental results and showed that the use of 60% BN composite achieved a PV performance increase of 0.3% compared to the standard laminate.

  13. 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...

  14. Midtemperature solar systems test facility predictions for thermal performance based on test data. Polisolar model POL solar collector with glass reflector surface

    Science.gov (United States)

    Harrison, T. D.

    1981-05-01

    Thermal performance predictions based on test data are presented for the Polisolar Model POL sola collector, with glass reflector surfaces, for three output temperatures at five cities in the United States.

  15. Thermal performance evaluation of the Northrop model NSC-01-0732 concentrating solar collector array at outdoor conditions. [Marshall Space Flight Center solar house test facility

    Science.gov (United States)

    1979-01-01

    The thermal efficiency of the concentrating, tracking solar collector was tested after ten months of operation at the Marshall Space Flight Center solar house. The test procedures and results are presented.

  16. Fuel Cell Thermal Management Through Conductive Cooling Plates

    Science.gov (United States)

    Colozza, Anthony J.; Burke, Kenneth A.

    2008-01-01

    An analysis was performed to evaluate the concept of utilizing conductive cooling plates to remove heat from a fuel cell stack, as opposed to a conventional internal cooling loop. The potential advantages of this type of cooling system are reduced stack complexity and weight and increased reliability through the reduction of the number of internal fluid seals. The conductive cooling plates would extract heat from the stack transferring it to an external coolant loop. The analysis was performed to determine the required thickness of these plates. The analysis was based on an energy balance between the thermal energy produced within the stack and the heat removal from the cooling plates. To accomplish the energy balance, the heat flow into and along the plates to the cooling fluid was modeled. Results were generated for various numbers of cells being cooled by a single cooling plate. The results provided cooling plate thickness, mass, and operating temperature of the plates. It was determined that utilizing high-conductivity pyrolitic graphite cooling plates can provide a specific cooling capacity (W/kg) equivalent to or potentially greater than a conventional internal cooling loop system.

  17. Thermal Fatigue Study on the Divertor Plate Materials

    Institute of Scientific and Technical Information of China (English)

    吴继红; 张斧; 许增裕; 严建成

    2002-01-01

    Thermal fatigue property of the divertor plate is one of the key issues that governs the lifetime of the divertor plate. Taking tungsten as surface material, a small-mock-up divertor plate was made by hot isostatic press welding (HIP). A thermal cycling experiment for divertor mock-up was carried out in the vacuum, where a high-heat-flux electronic gun was used as the thermal source. A cyclic heat flux of 9 MW/m2 was loaded onto the mock-up, a heating duration of 20 s was selected, the cooling water flow rate was 80 ml/s. After 1000 cycles, the surface and the W/Cu joint of the mock-up did not show any damage. The SEM was used to analyze the microstructure of the welding joint, where no cracks were found also.

  18. Comparision of Two Thermal Decomposition Offset Printing Plates

    Directory of Open Access Journals (Sweden)

    Ana Jereb

    2015-03-01

    Full Text Available The aim of our research was to investigate two digital plates based on the same type of thermal sensitive coating produced by different manufactures and compare their quality, run length, ecological and economical aspects and user experience in the offset press. It was found out that with both plates the same quality of prints was attained according to the measurements of tone values on the plates and prints. The spectrophotometric measurements also showed that the prints were almost identical, except for minor differences in lightness. The microscopic image analysis showed that one plate had finer graining and thereby gave better and more accurate representation of half-tone dot and this plate was also more environmentally–friendly with lower consumption of chemicals for the plate developing, more durable with longer run lengths and as well more economical and user–friendly. The obtained results were useful for the offset printing company in its choosing the better thermal plate with reduced production costs.

  19. Thermal-hydraulics of PGV-4 water volume during damage of the feedwater collector nozzles

    Energy Technology Data Exchange (ETDEWEB)

    Logvinov, S.A.; Titov, V.F. [OKB Gidropress (Russian Federation); Notaros, U.; Lenkei, I. [NPP Paks (Hungary)

    1995-12-31

    A number of VVER-440 plants has experienced the distributing nozzles of feedwater collector being damaged due to corrosion-erosion wearing. Such phenomenon could result in feedwater redistribution within the SG inventory with undesirable consequences. The collector with damaged nozzles has to be replaced but a certain time is needed for the preparatory works. The main objective of the investigation conducted is to assess if the safe operation of SG is possible before collector replacement. It was shown that the nozzle damage as observed did not result in the dangerous disturbances of thermobydraulics as compared with the conditions existing at the initial period of operation. (orig.).

  20. Thermal dependence of electrical characteristics of micromachined silica microchannel plates

    Science.gov (United States)

    Tremsin, Anton S.; Vallerga, John V.; Siegmund, Oswald H. W.; Beetz, Charles P.; Boerstler, Robert W.

    2004-04-01

    Micromachined silica microchannel plates (MCPs) under development have a number of advantages over standard glass MCPs and open completely new possibilities in detector technologies. In this article we present the results of our studies on the thermal properties of silica microchannel plates (sMCPs). Similar to standard glass microchanel plates the resistance of silica MCPs was measured to change exponentially with temperature with a negative thermal coefficient of -0.036 per °C, somewhat larger than that of standard glass MCPs. The resistance also decreases linearly with the applied voltage, with the voltage coefficient of -3.1×10-4 V-1. With the knowledge of these two coefficients, our thermal model allows the calculation of the maximum voltage, which can be applied to a given MCP without inducing a thermal runaway. A typical 25 mm diam, 240 μm thick sMCP with 6 μm pores has to have the resistance larger than ˜30 MΩ to operate safely at voltages up to 800 V. With this model we can also calculate the time required for a given silica MCP to reach the point of thermal equilibrium after a voltage increase. We hope that the ongoing efforts on a proper modification of the sMCP semiconducting layer will lead to the production of new MCPs with a small negative or even a positive thermal coefficient, reducing the possibility of thermal runaways of low-resistance MCPs required for high count rate applications.

  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....... Heat from the collectors is transferred to a domestic hot water storage tank or to a cold storage tank, which is used as the source for the heat pump. When the heat pump charges the warm storage tank, heat is extracted from the cold storage tank, which then can be reheated by the PVT collectors...

  2. Yearly average performance of the principal solar collector types

    Energy Technology Data Exchange (ETDEWEB)

    Rabl, A.

    1981-01-01

    The results of hour-by-hour simulations for 26 meteorological stations are used to derive universal correlations for the yearly total energy that can be delivered by the principal solar collector types: flat plate, evacuated tubes, CPC, single- and dual-axis tracking collectors, and central receiver. The correlations are first- and second-order polynomials in yearly average insolation, latitude, and threshold (= heat loss/optical efficiency). With these correlations, the yearly collectible energy can be found by multiplying the coordinates of a single graph by the collector parameters, which reproduces the results of hour-by-hour simulations with an accuracy (rms error) of 2% for flat plates and 2% to 4% for concentrators. This method can be applied to collectors that operate year-around in such a way that no collected energy is discarded, including photovoltaic systems, solar-augmented industrial process heat systems, and solar thermal power systems. The method is also recommended for rating collectors of different type or manufacturer by yearly average performance, evaluating the effects of collector degradation, the benefits of collector cleaning, and the gains from collector improvements (due to enhanced optical efficiency or decreased heat loss per absorber surface). For most of these applications, the method is accurate enough to replace a system simulation.

  3. Thermal Efficiency of Double Pass Solar Collector with Longitudinal Fins Absorbers

    Directory of Open Access Journals (Sweden)

    Ahmad Fudholi

    2011-01-01

    Full Text Available Problem statement: One of the most important components of a solar energy system is the solar collector. The performances of double-pass solar collector with longitudinal fins absorbers are analyzed. Approach: The study involves a theoretical study to investigate the effect of mass flow rate, number and height of fins on efficiency, which involves steady-state energy balance equations on the longitudinal fins absorber of solar collectors. The theoretical solution procedure of the energy equations uses a matrix inversion method and making some algebraic rearrangements. Results: The collector efficiency increases as the number and height of fins increases. For a mass flow rate 0.02- 0.1kg/s, the double-pass solar collectors are efficiency about 36-73% in upper fins (type I, 37-75% in lower fins (type II and 46-74% in upper and lower fins (type III. Conclusion: The efficiency of the collector is strongly dependent on the flow rate, efficiency increase is about 35%.

  4. Outdoor Performance Analysis of a Photovoltaic Thermal (PVT Collector with Jet Impingement and Compound Parabolic Concentrator (CPC

    Directory of Open Access Journals (Sweden)

    Ahed Hameed Jaaz

    2017-08-01

    Full Text Available This paper discusses the effect of jet impingement of water on a photovoltaic thermal (PVT collector and compound parabolic concentrators (CPC on electrical efficiency, thermal efficiency and power production of a PVT system. A prototype of a PVT solar water collector installed with a jet impingement and CPC has been designed, fabricated and experimentally investigated. The efficiency of the system can be improved by using jet impingement of water to decrease the temperature of the solar cells. The electrical efficiency and power output are directly correlated with the mass flow rate. The results show that electrical efficiency was improved by 7% when using CPC and jet impingement cooling in a PVT solar collector at 1:00 p.m. (solar irradiance of 1050 W/m2 and an ambient temperature of 33.5 °C. It can also be seen that the power output improved by 36% when using jet impingement cooling with CPC, and 20% without CPC in the photovoltaic (PV module at 1:30 p.m. The short-circuit current ISC of the PV module experienced an improvement of ~28% when using jet impingement cooling with CPC, and 11.7% without CPC. The output of the PV module was enhanced by 31% when using jet impingement cooling with CPC, and 16% without CPC.

  5. Outdoor Performance Analysis of a Photovoltaic Thermal (PVT) Collector with Jet Impingement and Compound Parabolic Concentrator (CPC)

    Science.gov (United States)

    Jaaz, Ahed Hameed; Hasan, Husam Abdulrasool; Sopian, Kamaruzzaman; Kadhum, Abdul Amir H.; Gaaz, Tayser Sumer

    2017-01-01

    This paper discusses the effect of jet impingement of water on a photovoltaic thermal (PVT) collector and compound parabolic concentrators (CPC) on electrical efficiency, thermal efficiency and power production of a PVT system. A prototype of a PVT solar water collector installed with a jet impingement and CPC has been designed, fabricated and experimentally investigated. The efficiency of the system can be improved by using jet impingement of water to decrease the temperature of the solar cells. The electrical efficiency and power output are directly correlated with the mass flow rate. The results show that electrical efficiency was improved by 7% when using CPC and jet impingement cooling in a PVT solar collector at 1:00 p.m. (solar irradiance of 1050 W/m2 and an ambient temperature of 33.5 °C). It can also be seen that the power output improved by 36% when using jet impingement cooling with CPC, and 20% without CPC in the photovoltaic (PV) module at 1:30 p.m. The short-circuit current ISC of the PV module experienced an improvement of ~28% when using jet impingement cooling with CPC, and 11.7% without CPC. The output of the PV module was enhanced by 31% when using jet impingement cooling with CPC, and 16% without CPC. PMID:28763048

  6. Outdoor Performance Analysis of a Photovoltaic Thermal (PVT) Collector with Jet Impingement and Compound Parabolic Concentrator (CPC).

    Science.gov (United States)

    Jaaz, Ahed Hameed; Hasan, Husam Abdulrasool; Sopian, Kamaruzzaman; Kadhum, Abdul Amir H; Gaaz, Tayser Sumer; Al-Amiery, Ahmed A

    2017-08-01

    This paper discusses the effect of jet impingement of water on a photovoltaic thermal (PVT) collector and compound parabolic concentrators (CPC) on electrical efficiency, thermal efficiency and power production of a PVT system. A prototype of a PVT solar water collector installed with a jet impingement and CPC has been designed, fabricated and experimentally investigated. The efficiency of the system can be improved by using jet impingement of water to decrease the temperature of the solar cells. The electrical efficiency and power output are directly correlated with the mass flow rate. The results show that electrical efficiency was improved by 7% when using CPC and jet impingement cooling in a PVT solar collector at 1:00 p.m. (solar irradiance of 1050 W/m² and an ambient temperature of 33.5 °C). It can also be seen that the power output improved by 36% when using jet impingement cooling with CPC, and 20% without CPC in the photovoltaic (PV) module at 1:30 p.m. The short-circuit current ISC of the PV module experienced an improvement of ~28% when using jet impingement cooling with CPC, and 11.7% without CPC. The output of the PV module was enhanced by 31% when using jet impingement cooling with CPC, and 16% without CPC.

  7. Unglazed photovoltaic-thermal collectors in combination with heat pumps and geothermal heat probes; Unverglaste photovoltaisch-thermische Kollektoren in Kombination mit Waermepumpen und Erdsonden

    Energy Technology Data Exchange (ETDEWEB)

    Bertram, E.; Stegmann, M.; Scheuren, J. [Institut fuer Solarenergieforschung GmbH Hameln/Emmerthal (ISFH), Emmerthal (Germany); Rosinski, C.; Kundmueller, K. [GEFGA mbH und Co. KG, Limburg (Germany)

    2010-07-01

    Unglazed Photovoltaic Thermal (PVT) collectors provide very high efficiency for heat and electricity generation at low temperatures. Therefore they are particularly suitable to support the heat source of heat pump systems, where low temperature heat is required. In this combination the PVT collector improves efficiency in two ways - of the heat pump by additional low temperature heat and of the photovoltaic by cooling. Between April and November 2009 an increase of 5% of photovoltaic electricity production and a high collector yield of 380 kWh/(m{sup 2} a) was measured on a pilot system. Of course, the improvement of the PV and heat pump efficiency depends strongly on the thermal PVT collector performance. In this context the performances of four different unglazed PVT collectors were measured and significant differences revealed. The conversion factor without electricity production varies from 0.33 to 0.73. Further, a model for unglazed PVT-collectors was developed. It is based on performance data of En 12975 and IEC 60904 only and considers thermal collector capacity and condensation effects. (orig.)

  8. Thermal buckling analysis of truss-core sandwich plates

    Institute of Scientific and Technical Information of China (English)

    陈继伟; 刘咏泉; 刘伟; 苏先樾

    2013-01-01

    Truss-core sandwich plates have received much attention in virtue of the high values of strength-to-weight and stiffness-to-weight as well as the great ability of impulse-resistance recently. It is necessary to study the stability of sandwich panels under the influence of the thermal load. However, the sandwich plates are such complex three-dimensional (3D) systems that direct analytical solutions do not exist, and the finite element method (FEM) cannot represent the relationship between structural parameters and mechanical properties well. In this paper, an equivalent homogeneous continuous plate is idealized by obtaining the effective bending and transverse shear stiffness based on the characteristics of periodically distributed unit cells. The first order shear deformation theory for plates is used to derive the stability equation. The buckling temperature of a simply supported sandwich plate is given and verified by the FEM. The effect of related parameters on mechanical properties is investigated. The geometric parameters of the unit cell are optimized to attain the maximum buckling temperature. It is shown that the optimized sandwich plate can improve the resistance to thermal buckling significantly.

  9. Modeling the absorption behavior of solar thermal collector coatings utilizing graded alpha-C:H/TiC layers.

    Science.gov (United States)

    Gruber, D P; Engel, G; Sormann, H; Schüler, A; Papousek, W

    2009-03-10

    Wavelength selective coatings are of common use in order to enhance the efficiency of devices heated by radiation such as solar thermal collectors. The use of suitable materials and the optimization of coating layer thicknesses are advisable ways to maximize the absorption. Further improvement is achievable by embedding particles in certain layers in order to modify material properties. We focus on optimizing the absorption behavior of a solar collector setup using copper as substrate, a layer of amorphous hydrogenated carbon with embedded titanium carbide particles (a-C:H/TiC), and an antireflection coating of amorphous silicon dioxide (aSiO(2)). For the setup utilizing homogeneous particle distribution, a relative absorption of 90.98% was found, while inhomogeneous particle embedding yielded 98.29%. These results are particularly interesting since until now, absorption of more than 95% was found only by using embedded Cr but not by using the more biocompatible Ti.

  10. Projection of distributed-collector solar-thermal electric power plant economics to years 1990-2000

    Science.gov (United States)

    Fujita, T.; Elgabalawi, N.; Herrera, G.; Turner, R. H.

    1977-01-01

    A preliminary comparative evaluation of distributed-collector solar thermal power plants was undertaken by projecting power plant economics of selected systems to the 1990 to 2000 time frame. The selected systems include: (1) fixed orientation collectors with concentrating reflectors and vacuum tube absorbers, (2) one axis tracking linear concentrator including parabolic trough and variable slat designs, and (3) two axis tracking parabolic dish systems including concepts with small heat engine-electric generator assemblies at each focal point as well as approaches having steam generators at the focal point with pipeline collection to a central power conversion unit. Comparisons are presented primarily in terms of energy cost and capital cost over a wide range of operating load factors. Sensitvity of energy costs for a range of efficiency and cost of major subsystems/components is presented to delineate critical technological development needs.

  11. Methodical Specifics of Thermal Experiments with Thin Carbon Reinforced Plates

    Directory of Open Access Journals (Sweden)

    O. V. Denisov

    2015-01-01

    Full Text Available Polymer composite materials (CM are widely used in creation of large space constructions, especially reflectors of space antennas. Composite materials should provide high level of specific stiffness and strength for space structures. Thermal conductivity in reinforcement plane is a significant factor in case of irregular heating space antennas. Nowadays, data on CM reinforcement plane thermal conductivity are limited and existing methods of its defining are imperfect. Basically, traditional methods allow us to define thermal conductivity in perpendicular direction towards the reinforcement plane on the samples of round or rectangular plate. In addition, the thickness of standard samples is larger than space antenna thickness. Consequently, new methods are required. Method of contact heating, which was developed by BMSTU specialists with long hollow carbon beam, could be a perspective way. This article is devoted to the experimental method of contact heating on the thin carbon plates.Thermal tests were supposed to provide a non-stationary temperature field with a gradient being co-directional with the plane reinforcement in the material sample. Experiments were conducted in vacuum chamber to prevent unstructured convection. Experimental thermo-grams processing were calculated by 1-d thermal model for a thin plate. Influence of uncertainty of experimental parameters, such as (radiation emission coefficients of sample surface, glue, temperature sensors and uncertainty of sensors placement on the result of defined thermal conductivity has been estimated. New data on the thermal conductivity in reinforcement plane were obtained within 295 - 375 K temperature range, which can be used to design and develop reflectors of precision space antennas. In the future it is expedient to conduct tests of thin-wall plates from carbon fiber-reinforced plastic in wide temperature range, especially in the low-range temperatures.

  12. 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.

  13. 槽式太阳能聚光集热器光热效率实验研究%Study on Thermal Performance of a Parabolic Trough Collector

    Institute of Scientific and Technical Information of China (English)

    熊亚选; 吴玉庭; 马重芳

    2012-01-01

    基于自行研究开发、呈东西轴布置的太阳能槽形抛物面聚光集热器,建立了评估其光热性能的实验台,对其光热特性进行了详细实验研究。实验结果表明聚光集热器效率较高。聚光器与全新集热器组成的太阳能槽形抛物面聚光集热器峰值效率达70%左右,聚光器结构性能较好,跟踪驱动系统精度较高;但部分集热器经过320℃以上的温度后快速老化,致使整个太阳能槽形抛物面聚光集热器的热性能逐渐下降。%Based on the parabolic trough collector designed and constructed by ourselves, a test band is established for evaluating the thermal performance of the parabolic trough collector. Expcriments on the thermal performance of the parabolic trough collector have been done in detail. Experimental results show a high thermal performance of the parabolic trough collector. Overall efficiency of the parabolic trough collector exceeds 70%, which means that thermal performance of the parabolic trough collector is higher, steel structure performance of the collector is higher, and precision of tracking and driving system is higher. Thermal perlbrmance of parabolic trough receivers used degraded rapidly, which reduces the overall therlnal performance of the parabolic trough collector gradually.

  14. Investigation and Measurement of Copper Nanofluid Impact on Thermal Efficiency of Solar Collectors

    Directory of Open Access Journals (Sweden)

    Assadi Morteza Khalaji

    2014-07-01

    Full Text Available This study compared the impacts of using copper nanofliud to enhance the efficiency of flat solar collectors with closed loop and under forced convection heat transfer circumstances to traditional work fluids. Various concentrations of nanoparticles in water and water/glycol, from 250ppm to 3000ppm, were examined for volume fraction impact. Results indicate that the laboratory tests were different from those under real conditions because of the high concentration of nanoparticles used in laboratory tests; however, by using nanofluid (even with low concentrations around 0.3% solar collector efficiency improved (3.2%.Results have also shown that the use of copper nanofluid in ethylene glycol as the base fluid causes a significant reduction in collector efficiency, due to the increase in viscosity. However, using higher flow rates caused the heat transfer rate to rise because of increased turbulence.

  15. A facile route for controlled alignment of carbon nanotube-reinforced, electrospun nanofibers using slotted collector plates

    Directory of Open Access Journals (Sweden)

    G. R. Rakesh

    2015-02-01

    Full Text Available A facile route for controlled alignment of electrospun multiwalled carbon nanotube (MWCNT-reinforced Polyvinyl Alcohol (PVA nanofibers using slotted collector geometries has been realized. The process is based on analytical predictions using electrostatic field analysis for envisaging the extent of alignment of the electrospun fibers on varied collector geometries. Both the experimental and theoretical studies clearly indicate that the introduction of an insulating region into a conductive collector significantly influences the electrostatic forces acting on a charged fiber. Among various collector geometries, rectangular slotted collectors with circular ends showed good fiber alignment over a large collecting area. The electrospun fibers produced by this process were characterized by Atomic Force Microscopy (AFM, High Resolution Transmission Electron Microscopy (HRTEM, Scanning Electron Microscopy (SEM and Optical Microscopy. Effects of electrospinning time and slot widths on the fiber alignment have been analyzed. PVA-MWCNT nanofibers were found to be conducting in nature owing to the presence of reinforced MWCNTs in PVA matrix. The method can enable the direct integration of aligned nanofibers with controllable configurations, and significantly simplify the production of nanofibersbased devices.

  16. Simulating Single-Effect Absorption Cooling Lithium Bromide A Solar System With Flat Plate Collector And Contribute To An Office Building

    OpenAIRE

    MIRI, Mohadaseh

    2015-01-01

    Use solar energy to provide hot water consumption, space heating and cooling in recent decades is considered. In this article a model varies with time, a solar adsorption cooling system consists of a single effect lithium bromide absorption system, a flat plate collector and a storage tank or linear or parabolic simulated separately. The system for cooling an office building for hours of operation from 7 am to 18 pm is considered.About 7 kW peak cooling load occurs in July. Results obtained s...

  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. Determination of Efficiency of Hybrid Photovoltaic Thermal Air Collectors Using Artificial Neural Network Approach for Different PV Technology

    Directory of Open Access Journals (Sweden)

    G. N. Tiwari

    2012-01-01

    Full Text Available In this paper an attempt has been made to determine efficiency of semi transparent hybrid photovoltaic thermal double pass air collector for different PV technology and compare it with single pass air collector using artificial neural network (ANN technique for New Delhi weather station of India. The MATLAB 7.1 neural networks toolbox has been used for defining and training of ANN for determination of thermal, electrical, overall thermal and overall exergy efficiency of the system. The ANN model uses ambient air temperature, number of sunshine hours, number of clear days, temperature coefficient, cell efficiency, global and diffuse radiation as input parameters. The transfer function, neural network configuration and learning parameters have been selected based on highest convergence during training and testing of network. About 2000 sets of data from four weather stations (Bangalore, Mumbai, Srinagar and Jodhpur have been given as input for training and data of the fifth weather station (New Delhi has been used for testing purpose. It has been observed that the best transfer function for a given configuration is logsig. The feed forward back-propagation algorithm has been used in this analysis. Further the results of ANN model have been compared with analytical values on the basis of root mean square error.

  19. Horizontal Fresnel collectors for solar thermal power stations; Horizontale Fresnel-Kollektoren fuer den Einsatz in Solarthermischen Kraftwerken

    Energy Technology Data Exchange (ETDEWEB)

    Mertins, M.; Lerchenmueller, H.; Wittwer, C. [Fraunhofer-Inst. fuer Solare Energiesysteme ISE, Freiburg (Germany); Haeberle, A. [PSE GmbH, Freiburg (Germany)

    2003-07-01

    The self-sustaining coverage of the huge and steadily increasing world energy-demand is one of the main tasks in the near future. A large contribution could be offered by solar thermal power plants in sun-belt countries. This renewable energy technology can reach electricity costs below 15 Euro ct/kWh depending on scale and location. A new line focussing collector based on the Fresnel-principle was developed by the Belgian company Solarmundo, which is very promising to lead to lower LEC. (orig.)

  20. A highly-compact packaging design for improving the thermal performance of multi-finger InGaP/GaAs collector-up HBTs

    Science.gov (United States)

    Tseng, Hsien-Cheng; Chen, Jhin-Yuan

    2011-02-01

    To satisfy the increasing demand for small power amplifiers in advanced cellular phones, we have investigated the thermal performance of multi-finger InGaP/GaAs collector-up HBTs with a heat-dissipation packaging configuration. The thermal interaction between collector fingers and the size effect on the maximum operation temperature within the transistor have been scrutinized. In addition, the thermal handling for a stable operation in the device has been optimized through the variation of finger pitches. The superior results show that the thickness of the heat-dissipation structure can be reduced by more than 35%, and the achieved thermal resistance can be effectively improved over 40%. Based on appropriate approaches from the 3-D numerical simulation for thickness-adjusting evaluation and the analytical analysis for finger-pitch optimization, a highly-compact packaging design is proposed for the miniaturization of collector-up HBTs in future mobile communication systems.

  1. Thermal losses od solar distiller assisted with accumulator solar collector; Perdidas termicas del destilador solar asistido con colector solar acumalador

    Energy Technology Data Exchange (ETDEWEB)

    Esteban, C.; Fasulo, A.; Franco, J.

    2004-07-01

    In the Laboratory of Solar Energy of the National University of San Luis (Argentina), we have developed and tested a solar collector accumulator of simple characteristics. The same one consists in a tank of stainless steel, covered with black paint, circular section, and thermically protected with several layers of alveolar polycarbonate. It was considered that a good application for this device would be the feeding thermal assistant for a basin-type distiller. It was constructed and the new solar distiller's behavior was evaluated. With the purpose of introducing improvements in the new still we study their thermal losses. We find that to increase the efficiency of the new device it is necessary: to diminish the thermal losses increasing the insulation, and to increase the efficiency in the collection of solar radiation. (Author)

  2. Testing of a solar collector with concentrating mirrors

    Science.gov (United States)

    1980-01-01

    Commerical flat-plate solar collector with concentrating mirrors has been tested for thermal performance, structured behavior under static load, and effects of long-term natural weathering. Report documents results of testing and concludes that absorptivity was degraded by weathering.

  3. Cocos plate gravity lineaments due to thermal contraction cracks

    Science.gov (United States)

    Balcerak, Ernie

    2011-09-01

    Gravity lineaments, narrow strips of stronger gravity, were first observed on the ocean floor in the south central Pacific several decades ago, but scientists still debate their origin. Because the south central Pacific gravity lineaments align with the tectonic plate motion, some scientists have suggested that they were created through small-scale convection cells below the lithosphere that become elongated as the plate moved. Other proposed explanations have included flow of low-viscosity material along the base of the the lithosphere and cracking of the lithosphere due to thermal contraction. Newly recognized gravity lineaments on the Cocos plate, which lies beneath the Pacific Ocean off the coast of Central America, could help scientists figure out how such lineaments form. Cormier et al. identified the lineaments using satellite altimetry data. They used gravity, bathymetric, and magnetic data to investigate the physical characteristics of the lineaments and how they changed over time. (Geochemistry, Geophysics, Geosystems, doi:10.1029/2011GC003573, 2011)

  4. THERMAL FRACTURE OF FUNCTIONALLY GRADED PLATE WITH PARALLEL SURFACE CRACKS

    Institute of Scientific and Technical Information of China (English)

    Yuezhong Feng; Zhihe Jin

    2009-01-01

    This work examines the fracture behavior of a functionally graded material (FGM) plate containing parallel surface cracks with alternating lengths subjected to a thermal shock. The thermal stress intensity factors (TSIFs) at the tips of long and short cracks are calculated using a singular integral equation technique. The critical thermal shock △T_c that causes crack initiation is calculated using a stress intensity factor criterion. Numerical examples of TSIFs and △T_c for an Al_2O_3/Si_3N_4 FGM plate are presented to illustrate the effects of thermal property gradation, crack spacing and crack length ratio on the TSIFs and △T_c. It is found that for a given crack length ratio, the TSIFs at the tips of both long and short cracks can be reduced significantly and △T_c can be enhanced by introducing appropriate material gradation. The TSIFs also decrease dramatically with a decrease in crack spacing. The TSIF at the tips of short cracks may be higher than that for the long cracks under certain crack geometry conditions. Hence, the short cracks instead of long cracks may first start to grow under the thermal shock loading.

  5. Hybrid thermoelectric solar collector design and analysis

    Science.gov (United States)

    Roberts, A. S., Jr.; Shaheen, K. E.

    1982-01-01

    A flat-plate solar collector is conceived where energy cascades through thermoelectric power modules generating direct-current electricity. The intent of this work was to choose a collector configuration and to perform a steady-state thermal performance assessment. A set of energy balance equations were written and solved numerically for the purpose of optimizing collector thermal and electrical performance. The collector design involves finned columns of thermoelectric modules imbedded in the absorber plate (hot junction) over a parallel array of vertical tubes. The thermoelectric power output is limited by the small hot-junction/cold-junction temperature difference which can be maintained under steady-state conditions. The electric power per unit tube pass area is found to have a maximum as a function of a geometric parameter, while electric power is maximized with respect to an electric resistance ratio. Although the electric power efficiency is small, results indicate that there is sufficient electric power production to drive a coolant circulator, suggesting the potential for a stand-alone system.

  6. Hybrid thermoelectric solar collector design and analysis

    Science.gov (United States)

    Roberts, A. S., Jr.; Shaheen, K. E.

    1982-01-01

    A flat-plate solar collector is conceived where energy cascades through thermoelectric power modules generating direct-current electricity. The intent of this work was to choose a collector configuration and to perform a steady-state thermal performance assessment. A set of energy balance equations were written and solved numerically for the purpose of optimizing collector thermal and electrical performance. The collector design involves finned columns of thermoelectric modules imbedded in the absorber plate (hot junction) over a parallel array of vertical tubes. The thermoelectric power output is limited by the small hot-junction/cold-junction temperature difference which can be maintained under steady-state conditions. The electric power per unit tube pass area is found to have a maximum as a function of a geometric parameter, while electric power is maximized with respect to an electric resistance ratio. Although the electric power efficiency is small, results indicate that there is sufficient electric power production to drive a coolant circulator, suggesting the potential for a stand-alone system.

  7. Step tracking program for concentrator solar collectors

    Science.gov (United States)

    Ciobanu, D.; Jaliu, C.

    2016-08-01

    The increasing living standards in developed countries lead to increased energy consumption. The fossil fuel consumption and greenhouse gas effect that accompany the energy production can be reduced by using renewable energy. For instance, the solar thermal systems can be used in temperate climates to provide heating during the transient period or cooling during the warmer months. Most used solar thermal systems contain flat plate solar collectors. In order to provide the necessary energy for the house cooling system, the cooling machine uses a working fluid with a high temperature, which can be supplied by dish concentrator collectors. These collectors are continuously rotated towards sun by biaxial tracking systems, process that increases the consumed power. An algorithm for a step tracking program to be used in the orientation of parabolic dish concentrator collectors is proposed in the paper to reduce the consumed power due to actuation. The algorithm is exemplified on a case study: a dish concentrator collector to be implemented in Brasov, Romania, a location with the turbidity factor TR equal to 3. The size of the system is imposed by the environment, the diameter of the dish reflector being of 3 meters. By applying the proposed algorithm, 60 sub-programs are obtained for the step orientation of the parabolic dish collector over the year. Based on the results of the numerical simulations for the step orientation, the efficiency of the direct solar radiation capture on the receptor is up to 99%, while the energy consumption is reduced by almost 80% compared to the continuous actuation of the concentrator solar collector.

  8. Non-Similar Computational Solution for Boundary Layer Flows of Non-Newtonian Fluid from an Inclined Plate with Thermal Slip

    Directory of Open Access Journals (Sweden)

    SUBBARAO ANNASAGARAM

    2016-01-01

    Full Text Available The laminar boundary layer flow and heat transfer of Casson non-Newtonian fluid from an inclined (solar collector plate in the presence of thermal and hydrodynamic slip conditions is analysed. The inclined plate surface is maintained at a constant temperature. The boundary layer conservation equations, which are parabolic in nature, are normalized into non-similar form and then solved numerically with the well-tested, efficient, implicit, stable Keller-box finite-difference scheme. Increasing velocity slip induces acceleration in the flow near the inclined plate surface. Increasing velocity slip consistently enhances temperatures throughout the boundary layer regime. An increase in thermal slip parameter strongly decelerates the flow and also reduces temperatures in the boundary layer regime. An increase in Casson rheological parameter acts to elevate considerably the velocity and this effect is pronounced at higher values of tangential coordinate. Temperatures are however very slightly decreased with increasing values of Casson rheological parameter.

  9. Central-receiver solar-thermal power system. Collector subsystem research experiments detail design report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1976-02-24

    The detail design (DD) of research experiment hardware for the collector subsystem (heliostats) to support the 10 MW/sub e/ Pilot Plant preliminary design (PD) is presented. Additionally, test plans for assembly, integration, and array tests are presented, along with results of completed component/material tests. Research experiment DD and tests described were planned to provide design verification and supporting data, with hardware which either duplicates, or closely simulates the Pilot Plant PD baseline. (WHK)

  10. Investigation and Measurement of Copper Nanofluid Impact on Thermal Efficiency of Solar Collectors

    OpenAIRE

    Assadi Morteza Khalaji; Nasersharifi Yahya

    2014-01-01

    This study compared the impacts of using copper nanofliud to enhance the efficiency of flat solar collectors with closed loop and under forced convection heat transfer circumstances to traditional work fluids. Various concentrations of nanoparticles in water and water/glycol, from 250ppm to 3000ppm, were examined for volume fraction impact. Results indicate that the laboratory tests were different from those under real conditions because of the high concentration of nanoparticles used in labo...

  11. Biological sample collector

    Science.gov (United States)

    Murphy, Gloria A.

    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.

  12. Monitoring of a flat plate solar thermal field supplying process heat

    Directory of Open Access Journals (Sweden)

    Cozzini Marco

    2016-01-01

    Full Text Available The article reports the performance data of a flat plate collector field installed in Austria and supplying process heat to a meat factory, up to a temperature of about 95 °C. The presented data span an entire year, thereby including seasonal effects and allowing for a full characterization of the system performances. Sensor uncertainty is also discussed in detail. Finally, a bin method analysis of the field efficiency is provided. To this purpose, different operating conditions are concisely represented by the so-called reduced temperature, typically used in solar collector applications.

  13. Quality and efficiency of solar collectors in Sweden

    Science.gov (United States)

    Wennerholm, H.

    Transparent or translucent insulation materials (TIM's) represent a new class of materials with a high potential for increasing the efficiency of solar thermal conversion systems. A large number of materials have been subjected to theoretical and experimental investigation. If materials that suppress heat losses are transparent to solar radiation, vacuum, certain gases, convection barriers, etc., then they can be regarded as TIM's. Exploratory field and laboratory studies of degraded FEP-film convection barriers in flat plate thermal solar collectors are described. The study related to collectors that had been operating in Sweden for periods of one year to ten years. Both physical, functional (thermal) and chemical aspects of degradation were considered. The report identifies the mistakes made so that they need not be repeated by the solar collector manufacturers in the future.

  14. Thermal performance optimization of a flat plate solar air heater using genetic algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Varun; Siddhartha [Department of Mechanical Engineering, National Institute of Technology, Hamirpur 177 005 (H.P.) (India)

    2010-05-15

    Thermal performance of solar air heater is low and different techniques are adopted to increase the performance of solar air heaters, such as: fins, artificial roughness etc. In this paper an attempt has been done to optimize the thermal performance of flat plate solar air heater by considering the different system and operating parameters to obtain maximum thermal performance. Thermal performance is obtained for different Reynolds number, emissivity of the plate, tilt angle and number of glass plates by using genetic algorithm. (author)

  15. 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)

  16. Simulation, construction and testing of a two-cylinder solar Stirling engine powered by a flat-plate solar collector without regenerator

    Energy Technology Data Exchange (ETDEWEB)

    Tavakolpour, Ali Reza; Zomorodian, Ali [Department of Mechanics of Farm Machinery Engineering, Shiraz University, Shiraz (Iran); Akbar Golneshan, Ali [Department of Mechanical Engineering, Shiraz University, Shiraz (Iran)

    2008-01-15

    In this research, a gamma-type, low-temperature differential (LTD) solar Stirling engine with two cylinders was modeled, constructed and primarily tested. A flat-plate solar collector was employed as an in-built heat source, thus the system design was based on a temperature difference of 80{sup o}C. The principles of thermodynamics as well as Schmidt theory were adapted to use for modeling the engine. To simulate the system some computer programs were written to analyze the models and the optimized parameters of the engine design were determined. The optimized compression ratio was computed to be 12.5 for solar application according to the mean collector temperature of 100{sup o}C and sink temperature of 20{sup o}C. The corresponding theoretical efficiency of the engine for the mentioned designed parameters was calculated to be 0.012 for zero regenerator efficiency. Proposed engine dimensions are as follows: power piston stroke 0.044 m, power piston diameter 0.13 m, displacer stroke 0.055 m and the displacer diameter 0.41 m. Finally, the engine was tested. The results indicated that at mean collector temperature of 110{sup o}C and sink temperature of 25{sup o}C, the engine produced a maximum brake power of 0.27 W at 14 rpm. The mean engine speed was about 30 rpm at solar radiation intensity of 900 W/m{sup 2} and without load. The indicated power was computed to be 1.2 W at 30 rpm. (author)

  17. Application of the Heat Pipe in Flat-Plate Solar Collectors%热管在平板式太阳能集热器中的应用研究

    Institute of Scientific and Technical Information of China (English)

    黄婷婷; 杜娜; 卿湛媛; 陈新; 牛宝联

    2014-01-01

    从集热器结构、传热效率、工艺、优缺点等方面详细介绍了3种常见的热管平板式太阳能集热器,它们包括蜂窝热管平板式、真空玻璃盖板热管平板式、CPC热管平板式太阳能集热器。与普通热管平板式集热器相比,3种改良方式均可降低集热器热损失,有效提高集热效率。通过对不同种类热管平板式太阳能集热器的热管种类、工作温度、结构参数等分析,发现随着温度升高,集热器集热效率下降,以及热管蒸发段长度普遍大于冷凝段长度等现象。%Three common heat pipe flat-plate solar collectors are introduced in details from the con-figuration of the collector such as heat transfer efficiency, crafts, merits, and so on, including the flat plate solar collector of honeycomb and heat pipe(HHCHP), flat plate solar collector of vacuum glass-cover board and heat pipe(HVGHP) and a compound parabolic concentrator heat pipe type solar collector(CPC). Com-pared with common heat pipe flat-plate solar collectors, these three improved programs can reduce heat loss, and effectively improve efficiency of the collector. From the analysis of different heat pipe types, oper-ating temperature, structure parameters, a phenomenon is discovered that whatever which type of heat pipe flat-plate solar collector is, as temperature goes up, the efficiency of the collectors drops and the length of evaporation is longer than the length of condensation.

  18. Experimental and Theoretical Study for Performance Enhancement of Air Solar Collectors by Using Different Absorbers

    Directory of Open Access Journals (Sweden)

    Ahmed A. Mohammad Saleh

    2016-09-01

    Full Text Available An experimental and theoretical study has been done to investigate the thermal performance of different types of air solar collectors, In this work air solar collector with a dimensions of (120 cm x90 cm x12 cm , was tested under climate condition of Baghdad city with a (43° tilt angel by using the absorber plate (1.45 mm thickness, 115 cm height x 84 cm width, which was manufactured from iron painted with a black matt. The experimental test deals with five types of absorber:- Conventional smooth flat plate absorber , Finned absorber , Corrugated absorber plate, Iron wire mesh on absorber And matrix of porous media on absorber . The hourly and average efficiency of the collectors were investigated for three values of mass flow rates (0.016 kg/s to 0.027 kg/s for each type of collector and then the porosity for the last collector type was tested by changing the porosity of porous media. A typical air solar collector has been studied Theoretically to build a standard software for testing any type of air solar collectors with local weather data . From the experimental study it can be seen by using some obstacle material to the air flow (fins, corrugated absorber plate, iron wire mesh porous media on the absorber could be enhanced the efficiencies not less than 4 % for finned type and 8 % for corrugated and 25 % for mesh and 30 % for porous media comparing with flat plate (smooth collector . Theoretically, the results showed that the collector with high convention heat transfer coefficient porous media has high hourly efficiency about (η = 56 % and iron wire mesh on absorber ( η = 52 % , on the other side the minimum performance occurred in the flat plate absorber (η = 28 %. Comparison of results reveals that the theoretical predictions agree reasonably well with experimental results. And the difference between the theoretical and experimental efficiency in general was between (1─ 15 %.

  19. Indoor test for the thermal performance evaluation of the DEC 8A large manifold sunmaster evacuated tube (liquid) solar collector

    Science.gov (United States)

    1981-01-01

    The Sunmaster DEC 8A Large Manifold solar collector using simulated conditions was evaluated. The collector provided 17.17 square feet of gross collector area. Test conditions, test requirements, an analysis of results, and tables of test data are reported.

  20. 太阳能集热器容水量对热系统性能影响的研究%THE EFFECTIVENESS OF WATER INERTIA ON THE THERMAL PERFORMANCE OF SOLAR COLLECTOR

    Institute of Scientific and Technical Information of China (English)

    高岩; 陈艳红; 范蕊; 张昕宇; 安玉娇

    2012-01-01

    Different from the traditional model, the thesis developed a new model for solar collector, considering the effect of inertia of water on the thermal performance of solar collector and compares the differences between the traditional models. This paper concludes the effectiveness of inertia of water on the outlet temperature, the control of pump in the solar energy system and the useful energy gain. Compared with the model without water inertia, the effect of water inertia is important; for all-glass evacuated tube collector the effect can be ignored owing to its less water inertia for flat plate collector. Less water inertia leads to more pump run-on time, and more effective energy will be collected.%所建立的太阳集热器动态模型不同于传统模型是因为其考虑了集热器容水量的热容对集热器热特性的影响.研究了该模型与传统模型的区别,分析了不同类型容水量对集热器出水水温、集热系统水泵的启停控制、有效集热量的影响.结果显示:水热容对全玻璃真空管集热器的出水温度影响明显;对于容水量较小的平板式集热器,水热容的影响相对较小;减少容水量会增加水泵开启时间,增加有效集热量.

  1. Thermally developing forced convection and the corresponding thermal stresses in a porous plate channel

    Institute of Scientific and Technical Information of China (English)

    YANG Xiao; LIU Xuemei

    2007-01-01

    Based on the Darcy fluid model, by considering the effects of viscous dissipation due to the interaction between solid skeleton and pore fluid flow and thermal conduction in the direction of the fluid flow, the thermally developing forced convection of the local thermal equili- brium and the corresponding thermal stresses in a semi- infmite saturated porous plate channel are investigated in this paper. The expressions of temperature, local Nusselt number and corresponding thermal stresses are obtained by means of the Fourier series, and the distributions of the same are also shown. Furthermore, influences of the Péclet number (Pe) and Brinkman number (Br) on temperature, Nusselt number (Nu) and thermal stress are revealed numerically.

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

    Energy Technology Data Exchange (ETDEWEB)

    Srithar, K. [Department of Mechanical Engineering, Thiagarajar College of Engineering, Madurai 625 015 (India); Mani, A. [Department of Mechanical Engineering, Indian Institute of Technology, Madras, Chennai 600 036 (India)

    2007-12-15

    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)

  3. Ferrocene-Boronic Acid-Fructose Binding Based on Dual-Plate Generator-Collector Voltammetry and Square-Wave Voltammetry.

    Science.gov (United States)

    Li, Meng; Xu, Su-Ying; Gross, Andrew J; Hammond, Jules L; Estrela, Pedro; Weber, James; Lacina, Karel; James, Tony D; Marken, Frank

    2015-06-10

    The interaction of ferrocene-boronic acid with fructose is investigated in aqueous 0.1 m phosphate buffer at pH 7, 8 and 9. Two voltammetric methods, based on 1) a dual-plate generator-collector micro-trench electrode (steady state) and 2) a square-wave voltammetry (transient) method, are applied and compared in terms of mechanistic resolution. A combination of experimental data is employed to obtain new insights into the binding rates and the cumulative binding constants for both the reduced ferrocene-boronic acid (pH dependent and weakly binding) and for the oxidised ferrocene-boronic acid (pH independent and strongly binding).

  4. Thermal performance of a solar cooker based on an evacuated tube solar collector with a PCM storage unit

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, S.D.; Sagara, Kazunobu [Osaka Univ., Dept. of Architectural Engineering, Suita, Osaka (Japan); Iwata, Takeshi; Kitano, Hiroaki [Mie Univ., Dept. of Architecture, Tsu (Japan)

    2005-03-01

    The thermal performance of a prototype solar cooker based on an evacuated tube solar collector with phase change material (PCM) storage unit is investigated. The design has separate parts for energy collection and cooking coupled by a PCM storage unit. Solar energy is stored in the PCM storage unit during sunshine hours and is utilized for cooking in late evening/night time. Commercial grade erythritol was used as a latent heat storage material. Noon and evening cooking experiments were conducted with different loads and loading times. Cooking experiments and PCM storage processes were carried out simultaneously. It was observed that noon cooking did not affect the evening cooking, and evening cooking using PCM heat storage was found to be faster than noon cooking. The cooker performance under a variety of operating and climatic conditions was studied at Mie, Japan. (Author)

  5. Thermal performance of solar district heating plants in Denmark

    DEFF Research Database (Denmark)

    Furbo, Simon; Perers, Bengt; Bava, Federico

    2014-01-01

    The market for solar heating plants connected to district heating systems is expanding rapidly in Denmark. It is expected that by the end of 2014 the 10 largest solar heating plants in Europe will be located in Denmark. Measurements from 23 Danish solar heating plants, all based on flat plate solar...... collectors mounted on the ground, shows measured yearly thermal performances of the solar heating plants placed in the interval from 313 kWh/m² collector to 493 kWh/m² collector with averages for all plants of 411 kWh/m² collector for 2012 and 450 kWh/m² collector for 2013. Theoretical calculations show...... of the cost/performance ratio for solar collector fields, both with flat plate collectors and with concentrating tracking solar collectors. It is recommended to continue monitoring and analysis of all large solar heating plants to document the reliability of the solar heating plants. It is also recommended...

  6. Graybox and adaptative dynamic neural network identification models to infer the steady state efficiency of solar thermal collectors starting from the transient condition

    Energy Technology Data Exchange (ETDEWEB)

    Roberto, Baccoli; Ubaldo, Carlini; Stefano, Mariotti; Roberto, Innamorati; Elisa, Solinas; Paolo, Mura [Institute of Technical Physics of the University of Cagliari, via Marengo 1, 09123 Cagliari (Italy)

    2010-06-15

    This paper deals with the development of methods for non steady state test of solar thermal collectors. Our goal is to infer performances in steady-state conditions in terms of the efficiency curve when measures in transient conditions are the only ones available. We take into consideration the method of identification of a system in dynamic conditions by applying a Graybox Identification Model and a Dynamic Adaptative Linear Neural Network (ALNN) model. The study targets the solar collector with evacuated pipes, such as Dewar pipes. The mathematical description that supervises the functioning of the solar collector in transient conditions is developed using the equation of the energy balance, with the aim of determining the order and architecture of the two models. The input and output vectors of the two models are constructed, considering the measures of 4 days of solar radiation, flow mass, environment and heat-transfer fluid temperature in the inlet and outlet from the thermal solar collector. The efficiency curves derived from the two models are detected in correspondence to the test and validation points. The two synthetic simulated efficiency curves are compared with the actual efficiency curve certified by the Swiss Institute Solartechnik Puffung Forschung which tested the solar collector performance in steady-state conditions according to the UNI-EN 12975 standard. An acquisition set of measurements of only 4 days in the transient condition was enough to trace through a Graybox State Space Model the efficiency curve of the tested solar thermal collector, with a relative error of synthetic values with respect to efficiency certified by SPF, lower than 0.5%, while with the ALNN model the error is lower than 2.2% with respect to certified one. (author)

  7. Cooled electronic system with liquid-cooled cold plate and thermal spreader coupled to electronic component

    Energy Technology Data Exchange (ETDEWEB)

    Chainer, Timothy J.; Graybill, David P.; Iyengar, Madhusudan K.; Kamath, Vinod; Kochuparambil, Bejoy J.; Schmidt, Roger R.; Steinke, Mark E.

    2016-04-05

    Apparatus and method are provided for facilitating cooling of an electronic component. The apparatus includes a liquid-cooled cold plate and a thermal spreader associated with the cold plate. The cold plate includes multiple coolant-carrying channel sections extending within the cold plate, and a thermal conduction surface with a larger surface area than a surface area of the component to be cooled. The thermal spreader includes one or more heat pipes including multiple heat pipe sections. One or more heat pipe sections are partially aligned to a first region of the cold plate, that is, where aligned to the surface to be cooled, and partially aligned to a second region of the cold plate, which is outside the first region. The one or more heat pipes facilitate distribution of heat from the electronic component to coolant-carrying channel sections of the cold plate located in the second region of the cold plate.

  8. Cooled electronic system with liquid-cooled cold plate and thermal spreader coupled to electronic component

    Energy Technology Data Exchange (ETDEWEB)

    Chainer, Timothy J.; Graybill, David P.; Iyengar, Madhusudan K.; Kamath, Vinod; Kochuparambil, Bejoy J.; Schmidt, Roger R.; Steinke, Mark E.

    2016-08-09

    Apparatus and method are provided for facilitating cooling of an electronic component. The apparatus includes a liquid-cooled cold plate and a thermal spreader associated with the cold plate. The cold plate includes multiple coolant-carrying channel sections extending within the cold plate, and a thermal conduction surface with a larger surface area than a surface area of the component to be cooled. The thermal spreader includes one or more heat pipes including multiple heat pipe sections. One or more heat pipe sections are partially aligned to a first region of the cold plate, that is, where aligned to the surface to be cooled, and partially aligned to a second region of the cold plate, which is outside the first region. The one or more heat pipes facilitate distribution of heat from the electronic component to coolant-carrying channel sections of the cold plate located in the second region of the cold plate.

  9. Enhancing the Heat Transfer of Flat-plate Solar Collector%平板太阳能集热器强化传热应用研究进展∗

    Institute of Scientific and Technical Information of China (English)

    吉佳文; 王文志; 李金凯; 段广彬; 刘宗明

    2016-01-01

    As the key part of the flat-plate solar water heater,the heat transfer performance of the collector is determined by the heat collector efficiency.The flat-plate solar collector with typical structure and heat transfer mode are described.Meanwhile the present technologies for enhancing heat transfer of flat-plate solar collector and the fu-ture development trend are reviewed and discussed.%集热器作为平板太阳能热水器的关键部分,其传热性能决定着热水器集热效率的高低。介绍了平板太阳能集热器的典型结构以及传热方式,综述了平板太阳能集热器目前所采用的强化传热方式及今后强化传热技术的发展趋势。

  10. Thermal performance of solar air collector with slit-like perforations

    Institute of Scientific and Technical Information of China (English)

    李宪莉; 由世俊; 张欢; 尤占平

    2009-01-01

    To offer a potentially low-cost and high-efficiency option for once-through applications,the unglazed transpired solar collector was studied. The semi-empirical correlation of overall heat exchange effectivenessε for UTC with circular holes was proposed to verify whether it being fit for this kind of absorber with slit-like perforations. The results show that in certain parameters,the predicted values of ε are very close to measured values,and the root mean square difference in betweens about 0.10,so the modle is suitable. Based on experimental results,this kind of absorber is proved to be feasible,with highest value of ε,up to 0.81. In addition,with the increase of γ,overall heat exchange effectiveness ε will decrease,i.e.,the value of ε will decrease with the increase of suction velocity vs or the decrease of wind velocity uw. However,the actual value of solar radiation intensity G and ambient temperature T∞ have little influence on ε.

  11. Cooling a solar telescope enclosure: plate coil thermal analysis

    Science.gov (United States)

    Gorman, Michael; Galapon, Chriselle; Montijo, Guillermo; Phelps, LeEllen; Murga, Gaizka

    2016-08-01

    The climate of Haleakalā requires the observatories to actively adapt to changing conditions in order to produce the best possible images. Observatories need to be maintained at a temperature closely matching ambient or the images become blurred and unusable. The Daniel K. Inouye Solar Telescope is a unique telescope as it will be active during the day as opposed to the other night-time stellar observatories. This means that it will not only need to constantly match the ever-changing temperature during the day, but also during the night so as not to sub-cool and affect the view field of other telescopes while they are in use. To accomplish this task, plate coil heat exchanger panels will be installed on the DKIST enclosure that are designed to keep the temperature at ambient temperature +0°C/-4°C. To verify the feasibility of this and to validate the design models, a test rig has been installed at the summit of Haleakalā. The project's purpose is to confirm that the plate coil panels are capable of maintaining this temperature throughout all seasons and involved collecting data sets of various variables including pressures, temperatures, coolant flows, solar radiations and wind velocities during typical operating hours. Using MATLAB, a script was written to observe the plate coil's thermal performance. The plate coil did not perform as expected, achieving a surface temperature that was generally 2ºC above ambient temperature. This isn't to say that the plate coil does not work, but the small chiller used for the experiment was undersized resulting in coolant pumped through the plate coil that was not supplied at a low enough temperature. Calculated heat depositions were about 23% lower than that used as the basis of the design for the hillers to be used on the full system, a reasonable agreement given the fact that many simplifying assumptions were used in the models. These were not carried over into the testing. The test rig performance showing a 23% margin

  12. 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)

  13. Experimental Research on the Thermal Performance of Unglazed Transpired Solar Air Collectors%无盖板渗透型太阳能空气集热器热性能的实验研究

    Institute of Scientific and Technical Information of China (English)

    高立新; 孙绍增; 王远锋

    2012-01-01

    Unglazed transpired solar air collectors have proven to be effective devices for ventilation air preheating and drying, which can be integrated with building easily. An experimental rig with solar col lector area of 2.2 m2 was set up to test the thermal performance of a solar air heating system based on un-glazed transpired solar collectors, and a series of experiments were conducted under real transient outdoor conditions from February 2009 to April 2009. Test results show that exit air temperature increase with increasing solar irradiation. The most important influencing factor on exit air temperature is solar irradiation, while the influence of ambient air temperature is negligible. Temperature rise decreases with increasing air flow rate, while collector thermal efficiency increases with increasing air flow rate. The average thermal efficiency of the experimental solar air heating system in the 3 - day test period was 58% , 63% , and 72% , respectively, which are higher than most conventional glazed flat - plate solar air collectors.%无盖板渗透型太阳能空气集热器是一种易于实现建筑一体化的高效新风预热及干燥装置.为了掌握无盖板渗透型集热器在实际工况下的热性能,建造了集热面积为2.2 m2的太阳能空气加热系统实验台,并在2009年2月至2009年4月对其热性能进行了户外瞬态实验研究.实验结果表明出口空气温度随辐射强度的增加而升高,太阳辐射强度是影响集热器出口空气温度的最重要因素,而室外空气温度的影响极小.空气温升随风量的增加而减小,集热器热效率随风量的增加而增大.在三个测试日中集热器的平均热效率分别为58%、63%和72%,高于普通平板太阳能空气集热器.

  14. 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)

  15. Energy and exergy analysis of PV/T air collectors connected in series

    Energy Technology Data Exchange (ETDEWEB)

    Dubey, Swapnil; Solanki, S.C. [Centre for Energy Studies, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016 (India); Tiwari, Arvind [Department of Design, Production and Management, University of Twente (Netherlands)

    2009-08-15

    In this paper an attempt has been made to derive the analytical expressions for N hybrid photovoltaic/thermal (PV/T) air collectors connected in series. The performance of collectors is evaluated by considering the two different cases, namely, Case I (air collector is fully covered by PV module (glass to glass) and air flows above the absorber plate) and Case II (air collector is fully covered by PV module (glass to glass) and air flows below the absorber plate). This paper shows the detailed analysis of energy, exergy and electrical energy by varying the number of collectors and air velocity considering four weather conditions (a, b, c and d type) and five different cities (New Delhi, Bangalore, Mumbai, Srinagar, and Jodhpur) of India. It is found that the collectors fully covered by PV module and air flows below the absorber plate gives better results in terms of thermal energy, electrical energy and exergy gain. Physical implementation of BIPV system has also been evaluated. If this type of system is installed on roof of building or integrated with building envelope will simultaneously fulfill the electricity generation for lighting purpose and hot air can be used for space heating or drying. (author)

  16. MATHEMATICAL MODELLING AND PERFORMANCE ANALYSIS OF DIFFERENT SOLAR AIR COLLECTORS

    Directory of Open Access Journals (Sweden)

    M. A. Karim

    2015-11-01

    Full Text Available The purpose of using solar air collectors is to raise the atmospheric air temperature to a temperature which can be used for various low and medium temperature applications. Collector, absorber and airflow arrangement are the most important components in the solar air collector. The performance of the collector depends on its heat loss and the absorber area that is in contact with the airflow. This study involves the theoretical simulation of the effect of mass flow rate on the performance, for flat plate and v-groove collectors that are in single and double pass configurations. Results show that the v-groove double pass air collector has the highest efficiency value of 56% at . The performance is greater than flat plate double pass collector, which has an efficiency of 54% under the same operating conditions. KEYWORDS: solar air collector; flat plate collector (fpc; v-groove collector; efficiency; single pass; double pass

  17. Cysteine-cystine redox cycling in a gold-gold dual-plate generator-collector microtrench sensor.

    Science.gov (United States)

    Hammond, Jules L; Gross, Andrew J; Estrela, Pedro; Iniesta, Jesus; Green, Stephen J; Winlove, C Peter; Winyard, Paul G; Benjamin, Nigel; Marken, Frank

    2014-07-15

    Thiols and disulfides are ubiquitous and important analytical targets. However, their redox properties, in particular on gold sensor electrodes, are complex and obscured by strong adsorption. Here, a gold-gold dual-plate microtrench dual-electrode sensor with feedback signal amplification is demonstrated to give well-defined (but kinetically limited) steady-state voltammetric current responses for the cysteine-cystine redox cycle in nondegassed aqueous buffer media at pH 7 down to micromolar concentration levels.

  18. Numerical Simulation Study on Flat Plate Solar Collectors in Series - connected System%直流式系统中平板型太阳能集热器数值模拟研究

    Institute of Scientific and Technical Information of China (English)

    倪贝; 丁昀; 杨庆

    2011-01-01

    As it is difficult to solve the problem of unsteady - state heat transfer in theory, study of flat plate solar collectors in series -connected system with intermittent output is conducted by numerical simulation.Under the unsteady - state heat transfer condition, the impact of the diameter and center distance of solar collectors on the instantaneous collector efficiency and water production rate per square meter are discussed respectively.The results show that flat cartridge collector performed high effeciency.And under the same conditions, the larger the diameter of collector is, the higher efficiency will be.These can be used for optimizing design parameters of flat plate solar collectors.%由于非稳态传热问题通过理论计算得到解析解较困难,本文运用数值模拟方法研究定温放水型直流式系统中平板型太阳能集热器的工作状况,讨论了集热器的管径和管中心距在非稳态传热条件下对集热器的效率和每平方米产水量的影响.可得到结论扁盒式集热器具有较高效率;相同条件下,管径越大集热器效率越高.该结果有利于优化直流式平板集热器的设计参数.

  19. Optimisation of solar collector foils with transparent thermal insulation. Final report; Optimierung von transparent waermegedaemmten Folien-Speicherkollektoren. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Michaelis, M

    1995-02-01

    The report describes storage collector foils which are used as hybrid systems. Contents: State of the art - solar test facility - tests on small test collectors - cost reduction. (HW) [Deutsch] Es wird berichtet ueber Folien-Speicherkollektoren, die als Hybridsysteme zum Einsatz kommen. Inhalt der Arbeit: - Stand der Technik - solare Testanlage - Untersuchungen an kleinen Testkollektoreinheiten - Kostenreduzierung. (HW)

  20. Outdoor test for thermal performance evaluation of the Owens-Illinois Sunpack SEC-601 (air) solar collector

    Science.gov (United States)

    1979-01-01

    The test procedures used and the test results obtained during the performance of an evaluation test program on the Owens-Illinois Sunpak, model SEC-601, air solar collector under natural outdoor weather conditions are presented. All testing activities were performed on a single module. The test was performed and the data evaluated as applicable to outdoor testing of solar collectors.

  1. 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....... The method is applied for horizons of up to 42 hours. Solar heating systems naturally come with a hot water tank, which can be utilized for energy storage also for other energy sources. Thereby such systems can become an important part of energy systems with a large share of uncontrollable energy sources......, such as wind power. In such a scenario online forecasting is a vital tool for optimal control and utilization of solar heating systems. The method is a two-step scheme, where first a non-linear model is applied to transform the solar power into a stationary process, which then is forecasted with robust time...

  2. 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

  3. 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)

  4. Adsorptive refrigeration system using a solar collector with a thermal insulating module; Sistema de refrigeracao adsortivo com a utilizacao de um coletor solar com anteparo otico

    Energy Technology Data Exchange (ETDEWEB)

    Gurgel, Jose Mauricio [Paraiba Univ., Joao Pessoa, PB (Brazil). Laboratorio de Energia Solar]. E-mail: gurgel@les.ufpb.br; Espinola Junior, Jose [Paraiba Univ., Joao Pessoa, PB (Brazil). Curso de Pos-Graduacao em Engenharia Mecanica; Andrade Filho, Luiz Simao [Paraiba Univ., Joao Pessoa, PB (Brazil). Centro de Tecnologia. Dept. de Tecnologia da Construcao Civil; Marcondes, Francisco [Paraiba Univ., Joao Pessoa, PB (Brazil). Escola de Engenharia. Dept. de Engenharia Mecanica

    2000-07-01

    The use of a solid adsorption cooling unit based on the binary silica gel/water couple constitute an very promising way to harness solar energy refrigeration purposes. Here is presented a mathematical model for the simulation of the system under several use conditions and it was shown coherent when compared with some experimental results. The several accomplished simulations showed the need to be projected a modulate reactor that can offer cooling easiness during the night period and shown the advantage of the use of an solar collector that can be easily opened and your thermal insulating module placed across the glass close the thermal radiation when the desorption process finish. The simulations results presented here shown an better COP for this configuration through an better cooling of the collector at night. (author)

  5. Experimental Analysis of Serpentine-flow Flat-plate Solar Collector%蛇形管平板式太阳能集热器的试验研究

    Institute of Scientific and Technical Information of China (English)

    李俊贤; 王辉涛; 王华; 包桂蓉

    2011-01-01

    A serpentine-flow flat-plate solar collector of small volume and large temperature difference is designed and developed in order to explore the fiat-plate solar collector used in high temperature situation. And experiment of stagnation and instantaneous efficiency is carried out. The results shown that stagnation temperature can reach 170.2 ℃ and heat loss coefficient is 5. 239 W/( m2 · ℃ ). Efficiency of solar collector between 52% —55% when inlet temperature of working fluid is 70 ℃. By comparison the temperature trend of various parts of the collector the corrective measure is proposed to improve performance of serpentine-flow fiat-plate solar collector in high temperature conditions.%为了探寻一种在中高温场合使用的平板式太阳能集热器,设计和开发了小流量、大温差的蛇形管平板式太阳能集热器,并进行了空晒试验和瞬时效率试验.试验结果表明:集热器的空晒温度可达170.2℃,热损系数为5.239 W/(m2·℃),载热工质进口温度70℃时效率52%-55%.通过对集热器各部分温度变化趋势的比较,提出改进措施,以提高蛇形管平板式集热器在中高温工况下的集热性能.

  6. Experiments and simulations on a thermosyphon solar collector with integrated storage

    Science.gov (United States)

    Toninelli, P.; Mariani, A.; Del, D., Col

    2015-11-01

    This paper deals with the thermal behaviour of a new type of flat solar collector that integrates the fluid storage tank. Often the main limitation of the solar thermosyphon installations is the prohibition to adopt external storage tanks due to their impact, especially for historical centres of particular architectural significance. To avoid this issue, a new system, that includes the collector and the storage, has been developed. This new apparatus works as a thermosyphon: it is possible to take advantage of the natural convection to avoid using a pump. Experimental tests have been conducted in such a collector with and without the absorbing plate. Furthermore, CFD simulations are reported to analyze in detail the dynamic thermal performance of the innovative solar collector and a good-agreement with the experimental tests has been found. Finally, both in numerical simulations and in experimental data the thermosyphon effect has been verified, obtaining the desired water temperature for domestic applications.

  7. THERMAL PERFORMANCE INVESTIGATION OF EVACUATED TUBE HEAT PIPE SOLAR COLLECTOR WITH NANOFLUID

    OpenAIRE

    N. H. Mujawar*, S. M. Shaikh

    2016-01-01

    Solar energy, being abundant and widespread in its availability, makes it one of the most attractive sources of energies. Tapping this energy will not only help in bridging the gap between demand and supply of electricity but shall also save money in the long run. A Solar Water Heating System (SWHS) is a device that makes available the thermal energy of the incident solar radiation for use in various applications by heating the water. Solar energy is one of the cleaner forms of renewable ener...

  8. Thermal Performance Evaluation of Friction Stir Welded and Bolted Cold Plates with Al/Cu Interface

    Science.gov (United States)

    Lakshminarayanan, A. K.; Suresh, M.; Sibi Varshan, M.

    2015-05-01

    An attempt is made to design and fabricate a cold plate with aluminum-copper dissimilar interface joined by friction stir welding. Optimum welding conditions for obtaining sound-quality corner and T joints with an aluminum-copper interface were established. Welded cross sections of the friction stir welded cold plate were analyzed to understand the bonding characteristics. Computational fluid dynamics (CFD) was used to evaluate the fluid-flow characteristics and thermal resistance of friction stir welded cold plate and the resulted are compared with the conventional bolted cold plate configuration. For CFD modeling of a cold plate with a dissimilar interface, a new methodology is proposed. From the CFD analysis and experimental results, it is observed that friction stir welded cold plate offered better thermal performance compared to the bolted cold plate and it is due to the metallurgical bonding at the aluminum-copper interface with the dispersion of copper particles.

  9. On the relationship between tectonic plates and thermal mantle plume morphology

    Science.gov (United States)

    Lenardic, A.; Kaula, W. M.

    1993-01-01

    Models incorporating plate-like behavior, i.e., near uniform surface velocity and deformation concentrated at plate boundaries, into a convective system, heated by a mix of internal and basal heating and allowing for temperature dependent viscosity, were constructed and compared to similar models not possessing plate-like behavior. The simplified numerical models are used to explore how plate-like behavior in a convective system can effect the lower boundary layer from which thermal plumes form. A principal conclusion is that plate-like behavior can significantly increase the temperature drop across the lower thermal boundary layer. This temperature drop affects the morphology of plumes by determining the viscosity drop across the boundary layer. Model results suggest that plumes on planets possessing plate-like behavior, e.g., the Earth, may differ in morphologic type from plumes on planets not possessing plate-like behavior, e.g., Venus and Mars.

  10. 四种交叉V型吸热板-底板太阳能空气集热器热性能的数值模拟对比分析%Numerical Simulation Study on Thermal Performance of Four Cross-V-Groove Solar Air Collectors

    Institute of Scientific and Technical Information of China (English)

    陈怀; 高文峰; 刘滔; 林文贤; 刘雪平

    2014-01-01

    作为最常用的一类平板型空气集热器,V型波纹吸热板空气集热器近年来被广泛应用和研究.采用相同几何尺寸(长2 m,宽1 m)的波形板,构成四种不同流道的交叉 V型吸热板-底板太阳能空气集热器,应用太阳载荷模型,利用 FLUENT 软件,对集热器在倾角为30°,入口空气流量为60 m3/h的工况进行了三维数值模拟,得到集热器不同位置的温度场、吸热板中心宽度0.5 m 处的平均努赛尔数和瞬时效率,并对其进行了对比分析,得出空气集热器的 V型吸热板横向放置、底板纵向放置结构的瞬时效率最高.%As one of the most commonly used flat plate air collectors,V-groove solar air collec-tor has been widely applied and studied in recent years.Based on solar load model,this paper used FLUENT to conduct three-dimensional numerical simulation on thermal performance of V-groove solar air collectors,whose length is 2 meters and 1 meter's width,V-groove plate has the same geometry size,with four types' flow channel at 30° tilt angle and the same air flow rate 60 m3/h.On the basis of the research,several results have been achieved:the temperature field of different section of absorbing plate,Nusselt number in the center of 0.5 m width absorbing plate section alone the length direction and instantaneous efficiency. Moreover,the analyses on the results showed that the instantaneous efficiency of structure is highest when V-groove ab-sorbing plate of air collector was horizontally placed and bottom plate longitudinal placed.The research provided innovative thoughts & reference and theoretical foundation for the design of solar air collector and engineering application.

  11. Ceramic Plate Solar Collector and Column Pile Structure Ceramic Solar Roof%陶瓷太阳板与锚桩结构陶瓷太阳能房顶的应用

    Institute of Scientific and Technical Information of China (English)

    孙启正; 许建华

    2012-01-01

    陶瓷太阳板以普通瓷土、工业废弃物为原料,具有制造工艺简单、生产耗能少、成本低、寿命长、效率高的优点;锚桩陶瓷太阳能房顶与原房顶共用结构层、保温层、防水层,结构简单、与建筑一体化、与建筑同寿命,为建筑物提供热水、取暖、空调的功能。%Ceramic plate solar collector, manufactured by common porcelain clay and industrial waste,has a lot of advantages such as simple process,low energy consumption,low cost,long life, high efficiency etc. Ceramic plate solar collector roof share the structure layer,insulation layer and waterproof layer with the origin roof. The roof has a simple structure, integration and same life with the building. Ceramic plate solar collector roof can supply hot water, heating and air condition to the building.

  12. Nonimaging solar thermal collector for high temperature terrestrial and space applications

    Science.gov (United States)

    Mouzouris, Michael; Brooks, Michael J.

    2009-08-01

    A point-focus solar concentrator is described for use in high temperature terrestrial and space applications. The system comprises a nonimaging reflective lens in the form of a ring array concentrator coupled to a fiber optic bundle through which the concentrated light is transmitted. Unlike mirror-based systems, the concentrator is a ring array composed of concentrically nested elements focusing energy to the rear of the structure. Energy is transported from the concentrator by optical fibers and directed at a target where high heat flux is needed. The fiber optic bundle is tailored for solar energy transmission and includes a fused end to minimize inter-fiber losses at the injection point. The integrated system is intended to produce concentrated thermal energy without the need for electricity intensive heating elements. Optical efficiency is investigated through a ray trace analysis.

  13. Thermal buckling analysis of annular FGM plate having variable thickness under thermal load of arbitrary distribution by finite element method

    Energy Technology Data Exchange (ETDEWEB)

    Ghomshei, Mansour Mohieddin; Abbasi, Vahid [Islamic Azad University, Alborz (Iran, Islamic Republic of)

    2013-04-15

    In this paper, a finite element formulation is developed for analyzing the axisymmetric thermal buckling of FGM annular plates of variable thickness subjected to thermal loads generally distributed nonuniformly along the plate radial coordinate. The FGM assumed to be isotropic with material properties graded in the thickness direction according to a simple power-law in terms of the plate thickness coordinate, and has symmetry with respect to the plate midplane. At first, the pre-buckling plane elasticity problem is developed and solved using the finite element method, to determine the distribution of the pre-buckling in-plane forces in terms of the temperature rise distribution. Subsequently, based on Kierchhoff plate theory and using the principle of minimum total potential energy, the weak form of the differential equation governing the plate thermal stability is derived, then by employing the finite element method, the stability equations are solved numerically to evaluate the thermal buckling load factor. Convergence and validation of the presented finite element model are investigated by comparing the numerical results with those available in the literature. Parametric studies are carried out to cover the effects of parameters including thickness-to-radius ratio, taper parameter and boundary conditions on the thermal buckling load factor of the plates.

  14. The use of collector efficiency test results in long term performance calculations. Revisions and clarifications in view of proper collector characterization and inter comparison

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Maria Joao; Horta, Pedro; Mendes, Joao Farinha [INETI - Inst. Nacional de Engenharia Tecnologia e Inovacao, IP, Lisboa (Portugal); Collares Pereira, Manuel; Carbajal, Wildor Maldonado [AO SOL, Energias Renovaveis, S.A., Samora Correia (Portugal)

    2008-07-01

    There are a growing number of solar thermal collector types: flat plates, evacuated tubes with and without backing reflectors and different tubular spacing, low concentration collectors, using different types of concentrating optics. These different concepts and designs all compete to be more efficient or simply cheaper, easier to operate, etc. at ever higher temperatures, and even to extend the use of solar thermal energy in other applications beyond the most common water heating for domestic purposes. This means that there is a growing need for the existing and future simulation tools to be as accurate as possible in the treatment of these different collector types, to allow for the proper dimensioning of solar thermal systems as well as the proper comparison of different collector technologies for a given application. This paper develops a systematic approach to the problem of the proper handling of solar radiation available to each collector type. The proposed methodology subdivides radiation in its different components, folding that with the information available from efficiency curve tests (steady state) for each collector type and the way the optics of each particular case transforms and uses the incident solar radiation. The suggestions made will hopefully be taken at the level of the testing standards themselves, rendering them more complete and general. (orig.)

  15. Investigation on Installation height of Storage Tank for Natural Circulation Flat Plate Solar Collector%自然循环平板式太阳能热水器水箱放置高度的研究

    Institute of Scientific and Technical Information of China (English)

    郑土逢; 李明; 魏生贤; 罗熙; 王炳灿

    2011-01-01

    The device of natural circulation flat plate solar water heater has been built.In accordance with the national testing standard methods, the efficiency of the system was tested.The transient model of NFSWH has been developed by using the TRNSYS simulation program.The effect of installation height between the bottom of the tank and the outlet of the collector on efficiency of the solar collector has been investigated both theoretically and experimentally.The data show the theoretical results are highly consistent with the experimental ones.Results indicate that the optimum value of installation height is 0.74m with the maximum efficiency of 67.5% for the system with a total area of 1.5m2 and a storage water tank capacity of 120L.When the installation height is between 0.44 and 1.04 m, the change of thermal efficiency of the solar system is at a range of 3%.%搭建了自然循环平板式太阳能热水器(NFSWH)的实验平台,根据太阳能热水器国家测试标准方法对系统的热效率进行测试.用TRNSYS软件建立了NFSWH的瞬态模型.模拟和实际测量了水箱放置高度对热水器热效率的影响.结果显示,实验与模拟吻合较好.对于集热面积为1.5m2水箱容积为120L的系统,水箱底到集热器出口的高度(Hr)为0.74m时,系统的热效率最大(67.7%).放置高度为0.44-1.04m时,系统集热效率变化不大,在3%以内.

  16. FINITE ELEMENT STRUCTURAL & THERMAL ANALYSIS OF LOCK PLATE

    OpenAIRE

    Mr. Ketan Patil; Mr. Roshan Marode; Prof. V. M. Chidri; Prof. A.J. Keche

    2012-01-01

    In Centrifugal Pipe Casting machine, hot molten metal is injected from one end and the other end remains closed by a covering plate having standard dimension. This covering plate is locked by a worker with the help of a spanner. This covering plate again needs to be opened after completion of casting process for the extraction of the pipe from the mould. This paper discuss mainly focused on the analysis of locking plate and its new design so that the humaninterference must be reduced to highe...

  17. Simple procedure for predicting long-term average performance of nonconcentration and of concentrating solar collectors

    Energy Technology Data Exchange (ETDEWEB)

    Collares-Pereira, M.; Rabl, A.

    1978-06-01

    The Liu and Jordan method of calculating long term average energy collection of flat plate collectors is simplified (by about a factor of 4), and generalized to all collectors, concentration and nonconcentrating. The only meteorological input needed are the long term average daily total hemispherical insolation H/sub h/ on a horizontal surface and, for thermal collectors the average ambient temperature. The collector is characterized by optical efficiency, heat loss (or U-value), heat extraction efficiency, concentration ratio and tracking mode. An average operating temperature is assumed. Interaction with storage can be included by combining the present model with the f-chart method of Beckman, Klein and Duffie. Formulas and examples are presented for five collector types: flat plate, compound parabolic concentrator, concentrator with E.-W. tracking axis, concentrator with polar tracking axis, and concentrator with two axis tracking. The examples show that even for relatively low temperature applications and cloudy climates (50/sup 0/C in New York in February), concentrating collectors can outperform the flat plate. The method has been validated against hourly weather data (with measurements of hemispherical and beam insolation), and has been found to have an average accuracy better than 3% for the long term average radiation available to solar collectors. The suitability of this method for comparison studies is illustrated by comparing in a location independent manner the radiation availability for several collector types or operating conditions: two axis tracking versus one axis tracking; polar tracking axis versus east-west tracking axis; fixed versus tracking flat plate; effect of ground reflectance; and acceptance for diffuse radiation as function of concentration ratio.

  18. 整体式太阳能空气集热器热性能研究%Thermal Performance Research of the Integral Solar Air Collector

    Institute of Scientific and Technical Information of China (English)

    吴国玉; 胡明辅; 毕二朋; 袁江

    2012-01-01

    A new type of integral solar air heat collector is introduced in the paper. According to a simplified model, a CFD software is applied to simulate the fields of flow, pressure and temperature. It is shown that in comparison with the integral solar air heat collector, there is a stagnation zone of flow in the inner part of the traditional assembly arrayed collector, the inner temperature distribution is not uniform, and there are also local high temperature zones on heat absorbing plates. The distributions of inner flow field, pressure field and temperature field are more uniform in the proposed one, the temperature gradient is obvious, and the effect of convective heat exchange between heat absorbing plates and air is better. So the heat property of the integral solar air heat collector is better than that of the traditional assembly arrayed air collector.%对一种新型的整体式太阳能空气集热器,根据简化的物理模型利用CFD软件对集热器内部的流场、压力场和温度场进行数值模拟分析,并与传统拼装式集热器阵列进行对比.结果表明,传统拼装式集热器阵列内部存在流动的滞留区,内部温度分布不均匀,吸热板有局部的高温区域;整体式空气集热器内部流场、压力场和温度场分布比较均匀,有明显的温度梯度,吸热板与空气能够更好的进行对流换热.因此,整体式空气集热器的热性能优于传统拼装式空气集热器阵列.

  19. High-Frequency Dynamic Analysis of Plates in Thermal Environments Based on Energy Finite Element Method

    Directory of Open Access Journals (Sweden)

    Di Wang

    2015-01-01

    Full Text Available The energy density governing equation to analyze the high-frequency dynamic behavior of plates in thermal environments is derived in this paper, in which the thermal effects are considered to change the membrane stress state and temperature dependent material properties of plates. Then the thermal effects on the energy reflection and transmission coefficients are dealt with hereof. Based on the above, an EFEM (energy finite element method based approximate approach for the energy analysis of coupled plates under nonuniform thermal environments is proposed. The approach could be conducted by three steps: (1 thermal analysis, (2 thermal stress analysis, and (3 forming element matrixes, joint matrixes, and the whole EFEM formulation for the energy analysis. The same mesh model is used for all the three steps. The comparison between EFEM results and classical modal superposition method results of simply supported plates in various uniform thermal environments and coupled plates in nonuniform thermal environments demonstrated that the derived energy governing equation and the proposed approach described well the smooth time- and locally space-averaged energy density. It is found that the distributions and levels of energy density are affected by thermal effects, and the variation trends are related to exciting frequency.

  20. Thermal Flexure Measurement and Inverse Characterization for a Tri-layer Thin Plate

    Institute of Scientific and Technical Information of China (English)

    HuaLu; Alireza Shirazi; Ahmad Varvani-Farahani

    2011-01-01

    The paper presents a new study on a tri-layer thin plate.Shadow moiré implemented with an advanced phase unwrapping technique is employed to obtain actual flexural deformation of a real-life plate sample subjected to thermal loads.An analytical model is re-formulated to provide the plate with global closed-form solutions of the plate deflection as well as the interfacial stress and strain.With the measurements and the solutions available,an inverse iterative approach is developed to evaluate and maximize the correlation between the measured and the predicted thermal flexure,leading to ascertained materials' constitutive and thermal behaviour.The inverse search algorithm starts with estimated ranges of material property parameters and progressively updates them to finally approach the respective true values.The established model solutions along with the optimized material properties matrix enable an accurate evaluation of the interfacial stresses/strains for the specific plate sample.

  1. Dynamic Analysis of the Titanium Alloy Plate under Thermal-acoustic Loadings

    Directory of Open Access Journals (Sweden)

    Zou Xuefeng

    2015-01-01

    Full Text Available Hypersonic vehicles structures suffer complex combined loadings generally. For the thin-walled structures and thermal protection systems of the aircraft, high temperature and intensity acoustic loadings are the significant factors that leading to their break. The object of this paper is typical simply supported titanium alloy plate, the finite element method was adopted to calculate the critical thermal buckling temperature the ordinal coupling method and Newmark method were adopted to calculate the thermal-acoustic dynamic response. Based on the FEM analysis, the power spectrum densities (PSD of center point was presented. Research results show that the thermal buckling of the typical simply supported titanium alloy plate occurs easily because of the low critical thermal buckling temperature, dynamic response of the thermal buckled plate suffering acoustic loads performs strong nonlinear characteristics and complex forms of exercise.

  2. A Novel Heat Pipe Plate for Passive Thermal Control of Fuel Cells Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR project aims to develop a lightweight, highly thermally and electrically conductive heat pipe plate for passive removal of the heat from the individual...

  3. An Analvsis on Thermal Performance of CPC Solar Collectors%复合抛物面太阳能集热器热性能分析

    Institute of Scientific and Technical Information of China (English)

    高宏宇; 王辉涛; 王华; 黄峻伟; 葛众

    2012-01-01

    对真空管式复合抛物面太阳能集热器的传热模型进行了分析,在总热损失系数、效率因子、热迁移因子和瞬时效率表达式的基础上,建立了有盖板带翅片的复合抛物面集热器性能预测模型,并对有盖板和无盖板两种类型接收器的集热器进行了瞬时效率的对比计算.结果表明:当集热介质与外界环境间温差较小时,在相同辐射强度的情况下,有盖板带翅片的复合抛物面集热器的集热效率反而比无盖板的复合抛物面集热器的集热效率低;而当集热介质与外界环境温差增加到一定程度时,有盖板带翅片的复合抛物面集热器显示了其集热效率高的优点.%By analyzing the heat-transfer model of compound parabolic concentrator(CPC) evacuated tube collector, and based on expressions respectively for the overall heat loss coefficient, thermal efficiency factor, heat removal factor and instantaneous efficiency, a performance prediction model has been developed for the finned CPC collector with glass cover, while a calculation and a comparison made to the instantaneous efficiency of collectors with and without glass cover. Results show that the collector with glass cover has a thermal efficiency even lower than that without glass cover, under the same radiation intensity, when the temperature difference is small between the working medium and the environment; however, when the temperature difference gets up to a certain degree, the former one will be better than the latter one, i. e. the collector with glass cover will have a higher thermal efficiency.

  4. Evaluation of protective ensemble thermal characteristics through sweating hot plate, sweating thermal manikin, and human tests.

    Science.gov (United States)

    Kim, Jung-Hyun; Powell, Jeffery B; Roberge, Raymond J; Shepherd, Angie; Coca, Aitor

    2014-01-01

    The purpose of this study was to evaluate the predictive capability of fabric Total Heat Loss (THL) values on thermal stress that Personal Protective Equipment (PPE) ensemble wearers may encounter while performing work. A series of three tests, consisting of the Sweating Hot Plate (SHP) test on two sample fabrics and the Sweating Thermal Manikin (STM) and human performance tests on two single-layer encapsulating ensembles (fabric/ensemble A = low THL and B = high THL), was conducted to compare THL values between SHP and STM methods along with human thermophysiological responses to wearing the ensembles. In human testing, ten male subjects performed a treadmill exercise at 4.8 km and 3% incline for 60 min in two environmental conditions (mild = 22°C, 50% relative humidity (RH) and hot/humid = 35°C, 65% RH). The thermal and evaporative resistances were significantly higher on a fabric level as measured in the SHP test than on the ensemble level as measured in the STM test. Consequently the THL values were also significantly different for both fabric types (SHP vs. STM: 191.3 vs. 81.5 W/m(2) in fabric/ensemble A, and 909.3 vs. 149.9 W/m(2) in fabric/ensemble B (p values are significantly different from the actual THL potential of the PPE ensemble tested on STM, (2) physiological benefits from wearing a more breathable PPE ensemble may not be feasible with incremental THL values (SHP test) less than approximately 150-200 W·m(2), and (3) the effects of thermal environments on a level of heat stress in PPE ensemble wearers are greater than ensemble thermal characteristics.

  5. Thermal Stresses in an Anisotropic Thin Plate Subjected to Moving Line Heat Sources

    Directory of Open Access Journals (Sweden)

    Malak Naji

    2014-02-01

    Full Text Available The aim of this present study is to investigate thermal stresses inside a thin anisotropic mild steal plate during moving line heat source. The parabolic heat conduction model is used for the prediction of the temperature history. The temperature distributions are determined numerically using finite difference method. Thermal stresses are computed numerically. It is found that the thermal conductivity ratio affect in both temperature and thermal stresses distributions, in additional to the speed and heat source intensity.

  6. Thermal analysis of a direct-gain room with shape-stabilized PCM plates

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Guobing; Zhang, Yinping; Lin, Kunping; Xiao, Wei [Department of Building Science, School of Architecture, Tsinghua University, Beijing 100084 (China)

    2008-06-15

    The thermal performance of a south-facing direct-gain room with shape-stabilized phase change material (SSPCM) plates has been analysed using an enthalpy model. Effects of the following factors on room air temperature are investigated: the thermophysical properties of the SSPCM (melting temperature, heat of fusion and thermal conductivity), inner surface convective heat transfer coefficient, location and thickness of the SSPCM plate, wall structure (external thermal insulation and wallboard material) etc. The results show that: (1) for the present conditions, the optimal melting temperature is about 20{sup o}C and the heat of fusion should not be less than 90 kJ kg{sup -1}; (2) it is the inner surface convection, rather than the internal conduction resistance of SSPCM, that limits the latent thermal storage; (3) the effect of PCM plates located at the inner surface of interior wall is superior to that of exterior wall (the south wall); (4) external thermal insulation of the exterior wall obviously influences the operating effect and period of the SSPCM plates and the indoor temperature in winter; (5) the SSPCM plates create a heavyweight response to lightweight constructions with an increase of the minimum room temperature at night by up to 3{sup o}C for the case studied; (6) the SSPCM plates really absorb and store the solar energy during the daytime and discharge it later and improve the indoor thermal comfort degree at nighttime. (author)

  7. Thermal stresses and deformations in a plate subject to the action of concentrated energy flows

    Energy Technology Data Exchange (ETDEWEB)

    Rudin, G.I.

    1988-09-01

    A two-dimensional problem concerned with the determination of thermal deformation and the temperature and stress fields in a plate subject to nonhomogeneous heating by a radiative flow of Gaussian type is solved. Cases in which one plate surface is either free or clamped onto a rigid base as well as cases in which the energy source is a laser beam are also considered. Factors such as the thermal diffusivity, specific heat, plate density, linear expansion, shear modulus, optical and energy absorption behavior, and refractivity are incorporated into the solution.

  8. Solar Heating Systems with Evacuated Tubular Solar Collector

    DEFF Research Database (Denmark)

    Qin, Lin; Furbo, Simon

    1998-01-01

    , 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......-plate collectors. For solar heating plants, the yearly energy output from these evacuated tubular collectors is about 40%-90% higher than the output from typical flat-plate collectors at an operation temperature of about 50°C.......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...

  9. Estimate of the energy and environment impacts attributed to solar thermal collectors in Brazil; Estimativa dos impactos energeticos e ambientais atribuida aos coletores solares termicos nas residencias brasileiras

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, Rafael Balbino [Universidade Federal de Itajuba (UNIFEI), Itabira, MG (Brazil)], E-mail: cardosorb@unifei.edu.br; Nogueira, Luiz Augusto Horta [Universidade Federal de Itajuba (UNIFEI), MG (Brazil)], E-mail: horta@unifei.edu.br

    2011-04-15

    The present study esteem the energy impacts, in terms of energy saving and reduction of peak demand, Real and Potential, as well as the environmental impacts, in terms of greenhouse gases (GHG) emission reduction, attributed to the use of solar thermal collectors in Brazil, in substitution to the electric showers. The evaluation of the energy saving, starting from the F Method, it was disaggregated in regional level, for the calculations of the solar fractions and distribution of the market and, starting from the energy saving and factor of national system emission, it was calculated the reductions of GHG effect. According to evaluations the use of solar thermal collectors in Brazil generated energy savings of the order of 1,073.2 GWh, what results in about 51,514 tCO{sub 2} of GHG emission reduction, equivalent to 104 thousand petroleum barrels, the year of 2008 and a reduction of peak demand of 1,220 MW, about 1.5% of the maximum demand registered on that year. It was verified, also, that Brazil uses less than 5% of the potential of solar thermal energy in the residential sector for water heating. (author)

  10. 全玻璃真空太阳集热管光-热性能%SOLAR THERMAL PERFORMANCE OF ALL-GLASS EVACUATED COLLECTOR TUBES

    Institute of Scientific and Technical Information of China (English)

    殷志强; 唐轩

    2001-01-01

    Three solar thermal parameters,i.e.heat loss coeffi cientULT,irradiation H and stagnation par ameter Y of all-glass evacuated collector tubes were derived on the basis of energy balance equation,which depen ds on solar transmittance of cover glass tube,solar absorptance and thermal emit tance of the selective absorbing surface and gas pressure in the jacket between cover and inner glass tubes,and solar irradiance,temperatures and the geometry o f the collector tube.Calculated results of solar thermal parameters of all-glass evacuated collector tubes agree well with experiments.These solar thermal param eters of all-glass evacuated collector tube were adopted by China national stand ard GB/T 17049-1997.%从能量平衡方程导出全玻璃真空太阳集热管的3个光-热性能参数,即热损系数ULT、闷晒太阳曝辐量H和空晒性能参数Y与真空集热管的罩管玻璃的太阳透射比τ、选择性吸收表面的太阳吸收比α、发射比ε、和集热管内的气体压强p,以及太阳辐照度、环境温度和真空太阳集热管的几何尺寸等函数关系。理论计算的真空太阳集热管的3个热性能参数与实验的结果比较一致。上述全玻璃真空太阳集热管的光-热性能参数已经被国家标准《全玻璃真空太阳集热管》(GB/T17049-1997)采用。

  11. Theoretical variations of the thermal performance of different solar collectors and solar combi systems as function of the varying yearly weather conditions in Denmark

    DEFF Research Database (Denmark)

    Andersen, Elsa; Furbo, Simon

    2009-01-01

    The thermal performances of solar collectors and solar combi systems with different solar fractions are studied under the influence of the Danish Design Reference Year, DRY data file, and measured weather data from a solar radiation measurement station situated at the Technical University...... of Denmark in Kgs. Lyngby. The data from DRY data file are used for any location in Denmark. The thermal performances of the solar heating systems are calculated by means of validated computer models. The measured yearly solar radiation varies by approximately 23% in the period from 1990 until 2002......, and the investigations show that it is not possible to predict the yearly solar radiation on a tilted surface based on the yearly global radiation. The annual thermal performance of solar combi systems cannot with reasonable approximation be fitted to a linear function of the annual total radiation on the solar...

  12. 10-MWe solar-thermal central-receiver pilot plant: collector subsystem foundation construction. Revision No. 1

    Energy Technology Data Exchange (ETDEWEB)

    1979-12-18

    Bid documents are provided for the construction of the collector subsystem foundation of the Barstow Solar Pilot Plant, including invitation to bid, bid form, representations and certifications, construction contract, and labor standards provisions of the Davis-Bacon Act. Instructions to bidders, general provisions and general conditions are included. Technical specifications are provided for the construction. (LEW)

  13. Midtemperature solar systems test facility predictions for thermal performance of the Acurex solar collector with FEK 244 reflector surface

    Science.gov (United States)

    Harrison, T. D.

    1981-01-01

    A detailed account of the methods used to make the predictions is given. The performance predictions are part of a program to measure the characteristics of commercially available solar collectors that have the potential for use in industrial process heat and enhanced oil recovery applications.

  14. Midtemperature Solar Systems Test Facility Program for predicting thermal performance of line-focusing, concentrating solar collectors

    Science.gov (United States)

    Harrison, T. D.

    1980-11-01

    The qualifications of the laboratories selected to do the testing and the procedure for selecting commercial collectors for testing are given. The testing program is outlined. The computer program for performance predictions is described. An error estimate for the predictions and a sample of outputs from the program are included.

  15. PRELIMINARY EXPERIMENT STUDY ON THE THERMAL PERFORMANCE OF A PARABOLIC TROUGH COLLECTOR%槽式太阳能聚光集热器光热性能初步试验研究

    Institute of Scientific and Technical Information of China (English)

    熊亚选; 吴玉庭; 马重芳; 张业强

    2012-01-01

    Based on the test band of parabolic trough collectors designed and constructed ourselves, thermal performance of the parabolic trough collector with a single west-east axis was studied in detail. Experimental results show that, thermal performance of the parabolic trough collectors is high, and the conversion rate of solar irradiance to heat exceeds 60%. Error of way of semi-automatic tracking and control is large and tracking precision of parabolic trough collectors is low, which cause the large fluctuation of heat gain of the parabolic trough collector and influences the thermal performance greatly. The semi-automatic tracking and control of parabolic trough collectors can not meet the demands of solar thermal power plants, and a real-time and automated tracking and control system should be adopted to optimize the thermal performance of the parabolic trough collectors.%对自行设计搭建的呈东西轴布置的槽式太阳能聚光集热器实验系统进行热性能实验研究.实验研究表明,槽式太阳能聚光集热器的光热性能较好,光热转换效率超过60%;半自动跟踪控制方法误差大、精度低,导致聚光集热器集热量变化较大;跟踪误差的大小对系统的热性能影响较大,无法满足太阳能热发电的要求,必须采用实时自动跟踪的方式才能达到最优聚光集热效果.

  16. Weathering of a liquid solar collector

    Science.gov (United States)

    1980-01-01

    Commercially available flate plate hot water solar collector is characterized in report that presents 10 month weathering study of system. Collector efficiency was calculated and plotted from measurements of fluid temperature and flow rate, ambient temperature and solar flux. Windspeed and wind direction were also measured during tests.

  17. EFFECTS OF THERMAL CONDUCTIVITY ON UNSTEADY MHD FREE CONVECTIVE FLOW OVER A SEMI INFINITE VERTICAL PLATE

    Directory of Open Access Journals (Sweden)

    P. LOGANATHAN,

    2010-11-01

    Full Text Available The numerical study of effects of thermal conductivity on unsteady MHD free convective flow over an isothermal semi infinite vertical plate is presented. It is assumed that the thermal conductivity of the fluid as a linear function of temperature. A magnetic field is applied transversely to the direction of the flow. The boundary layer equations of continuity, momentum and energy equations are transformed into non-linear coupled equations and then solved using implicit finite-difference method of Crank-Nicholson type. A parametric study is performed to illustrate the influence of thermal conductivity, magnetic parameter and Prandtl number on the velocity and temperature profiles. In addition, the local and average skin friction, Nusselt number at the plate are shown graphically for both air and water. An analysis of the results obtained shows that the flowfield is influenced appreciably by the strength of magnetic field, thermal conductivity at the wall of the plate.

  18. Solar collector manufacturing activity, 1992

    Energy Technology Data Exchange (ETDEWEB)

    1993-11-09

    This report presents data provided by US-based manufacturers and importers of solar collectors. Summary data on solar thermal collector shipments are presented for the years 1974 through 1992. Summary data on photovoltaic cell and module shipments are presented for the years 1982 through 1992. Detailed information for solar thermal collectors and photovoltaic cells and modules are presented for 1992. Appendix A describes the survey methodology. Appendix B contains the 1992 survey forms and instructions. Appendices C and D list the companies that responded to the 1992 surveys and granted permission for their names and addresses to appear in the report. Appendix E provides selected tables from this report with data shown in the International System of Units (SI) metric units. Appendix F provides an estimate of installed capacity and energy production from solar collectors for 1992.

  19. 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%.

  20. Long-Term Weather Data Measurements From A Danish Climate Station And The Weather’s Influence On The Thermal Performance Of Solar Collectors

    Directory of Open Access Journals (Sweden)

    Skalík Lukáš

    2015-06-01

    Full Text Available A weather data evaluation from a climate station in Lyngby, Denmark, was carried out. Twenty years of measurements show that the increase in global radiation was almost 3.5 kWh/m2 per year, corresponding to a growth of the yearly global radiation of 7 % for the last 20 years. The global radiation variation between the least sunny year to the sunniest year was 20%. The increase in diffuse radiation was 1.9 kWh/m2 per year, corresponding to 20 years’ growth of up to 7 %. The annual diffuse radiation of nearly 19 % varied from the least cloudy year to the cloudiest year. A small increase was measured for the ambient air temperature. The measurements showed a yearly increase of 0.04 K per year. The average yearly ambient air temperature variation from the coldest to the warmest year was 3.1 K. According to the seasonal growth of the parameters measured, the ambient air temperature and diffuse radiation increased the most in the summer period, while the global radiation significantly increased in the spring months. The calculations of the solar collector's thermal performance in Lyngby showed that the energy output was mostly dependent on beam radiation. The ambient air temperature did not have a high influence on the thermal performance of the solar collectors compared to the influence of the total solar radiation.

  1. Solar thermal system engineering guidebook

    Science.gov (United States)

    Selcuk, M. K.; Bluhm, S. A.

    1983-05-01

    This report presents a graphical methodology for the preliminary evaluation of solar thermal energy plants by Air Force base civil engineers. The report is organized as a Guidebook with worksheets and nomograms provided for rapid estimation of solar collector area, land area, energy output, and thermal power output of a solar thermal plant. Flat plate, evacuated tube, parabolic trough, and parabolic dish solar thermal technologies are considered.

  2. A two-dimensional finite-difference solution for the transient thermal behavior of a tubular solar collector

    Science.gov (United States)

    Lansing, F. L.

    1980-01-01

    A numerical procedure was established using the finite-difference technique in the determination of the time-varying temperature distribution of a tubular solar collector under changing solar radiancy and ambient temperature. Three types of spatial discretization processes were considered and compared for their accuracy of computations and for selection of the shortest computer time and cost. The stability criteria of this technique were analyzed in detail to give the critical time increment to ensure stable computations. The results of the numerical analysis were in good agreement with the analytical solution previously reported. The numerical method proved to be a powerful tool in the investigation of the collector sensitivity to two different flow patterns and several flow control mechanisms.

  3. Two-phase flow pattern measurements with a wire mesh sensor in a direct steam generating solar thermal collector

    Science.gov (United States)

    Berger, Michael; Mokhtar, Marwan; Zahler, Christian; Willert, Daniel; Neuhäuser, Anton; Schleicher, Eckhard

    2017-06-01

    At Industrial Solar's test facility in Freiburg (Germany), two phase flow patterns have been measured by using a wire mesh sensor from Helmholtz Zentrum Dresden-Rossendorf (HZDR). Main purpose of the measurements was to compare observed two-phase flow patterns with expected flow patterns from models. The two-phase flow pattern is important for the design of direct steam generating solar collectors. Vibrations should be avoided in the peripheral piping, and local dry-outs or large circumferential temperature gradients should be prevented in the absorber tubes. Therefore, the choice of design for operation conditions like mass flow and steam quality are an important step in the engineering process of such a project. Results of a measurement with the wire mesh sensor are the flow pattern and the plug or slug frequency at the given operating conditions. Under the assumption of the collector power, which can be assumed from previous measurements at the same collector and adaption with sun position and incidence angle modifier, also the slip can be evaluated for a wire mesh sensor measurement. Measurements have been performed at different mass flows and pressure levels. Transient behavior has been tested for flashing, change of mass flow, and sudden changes of irradiation (cloud simulation). This paper describes the measurements and the method of evaluation. Results are shown as extruded profiles in top view and in side view. Measurement and model are compared. The tests have been performed at low steam quality, because of the limits of the test facility. Conclusions and implications for possible future measurements at larger collectors are also presented in this paper.

  4. Prospect of Solar Thermal Power and Experimental Research of Parabolic Trough Thermal Collector%太阳能热发电的应用前景及槽式集热器实验研究

    Institute of Scientific and Technical Information of China (English)

    熊亚选; 吴玉庭; 马重芳

    2012-01-01

    太阳能热发电是解决未来我国能源供应的主要途径,槽式太阳能热发电技术是经济可行、技术可靠,并经过30年商业化验证的。槽式太阳能聚光集热器是槽式太阳能热发电系统的核心部件,建立了用于槽式太阳能聚光集热器光热性能研究的实验台,对所设计的大型槽式太阳能聚光集热器的光热性能进行了实验研究。结果表明:聚光器与全新集热管组成的槽式太阳能聚光集热器的光热转化率达70%左右;部分集热管经过320℃的导热油后材质老化,影响聚光集热器的光热性能。%Solar energy is a key solution to China's energy supply in the future. Solar parabolic trough power generation is a technology-mature and economy-feasible solar thermal power technology and has been verified through commercialization in the past 30 years. The parabolic trough collector is the core part of the solar parabolic trough power generation. A test platform is established for evaluating the thermal performance of the parabolic trough collector. The testing results indicate that the parabolic trough collector has a high thermal performance with the overall conversion ratio from solar radiation to high temperature heat exceeding 70%; some solar collector tubes are aged rapidly by the 320 ℃ thermal oil, which reduces the overall thermal performance of the parabolic trough collector.

  5. Synchronized molecular-dynamics simulation for the thermal lubrication of a polymeric liquid between parallel plates

    CERN Document Server

    Yasuda, Shugo

    2015-01-01

    The Synchronized Molecular-Dynamics simulation which was recently proposed by authors [Phys. Rev. X {\\bf 4}, 041011 (2014)] is applied to the analysis of polymer lubrication between parallel plates. The rheological properties, conformational change of polymer chains, and temperature rise due to the viscous heating are investigated with changing the values of thermal conductivity of the polymeric liquid. It is found that at a small applied shear stress on the plate, the temperature of polymeric liquid only slightly increases in inverse proportion to the thermal conductivity and the apparent viscosity of polymeric liquid is not much affected by changing the thermal conductivity. However, at a large shear stress, the transitional behaviors of the polymeric liquid occur due to the interplay of the shear deformation and viscous heating by changing the thermal conductivity. This transition is characterized by the Nahme-Griffith number $Na$ which is defined as the ratio of the viscous heating to the thermal conducti...

  6. Thermal Stress Analysis of Laminated Composite Plates using Shear Flexible Element

    Directory of Open Access Journals (Sweden)

    M. Ganapathi

    1996-01-01

    Full Text Available Using degree Centigrade shear flexible QUAD-9 plate element, stresses and deflections in composite laminated plates due to thermal loads analysed. A formulation based on first order shear deformation theory has been employed for the analysis. The effects of various parameters, such as ply-angle, number of layers, thickness and aspect ratios on stresses and deflections are brought out. The present formulation is being extended for studying composite shell structures.

  7. Evaluation of Transverse Thermal Stresses in Composite Plates Based on First-Order Shear Deformation Theory

    Science.gov (United States)

    Rolfes, R.; Noor, A. K.; Sparr, H.

    1998-01-01

    A postprocessing procedure is presented for the evaluation of the transverse thermal stresses in laminated plates. The analytical formulation is based on the first-order shear deformation theory and the plate is discretized by using a single-field displacement finite element model. The procedure is based on neglecting the derivatives of the in-plane forces and the twisting moments, as well as the mixed derivatives of the bending moments, with respect to the in-plane coordinates. The calculated transverse shear stiffnesses reflect the actual stacking sequence of the composite plate. The distributions of the transverse stresses through-the-thickness are evaluated by using only the transverse shear forces and the thermal effects resulting from the finite element analysis. The procedure is implemented into a postprocessing routine which can be easily incorporated into existing commercial finite element codes. Numerical results are presented for four- and ten-layer cross-ply laminates subjected to mechanical and thermal loads.

  8. NUMERICAL ANALYSIS AND EXPERIMENT OF UNSTEADY THERMAL FIELDOF ROTOR PLATE FOR EDDY CURRENT RETARDER

    Institute of Scientific and Technical Information of China (English)

    LIU Chengye; HE Ren

    2008-01-01

    The physical model based on heat transfer theory and virtual boundary method for analyzing unsteady thermal field of rotor plate for eddy current retarder used in automobile is established and boundary conditions are also defined. The finite element governing equation is derived by Galerkin method. The time differential item is discrete based on Galerkin format that is stable at any condition. And a new style of varying time step method is used in iteration process. The thermal field on the rotor plate at the radial and axle directions is analyzed and varying temperature at appointed points on two side-surfaces is measured. The testing and analytical data are uniform approximately. Finite element method can be used for estimating thermal field of the rotor plate at initial design stage of eddy current retarder.

  9. Thermo elastic waves with thermal relaxation in isotropic micropolar plate

    Indian Academy of Sciences (India)

    Soumen Shaw; Basudeb Mukhopadhyay

    2011-04-01

    In the present investigation, we have discussed about the features of waves in different modes of wave propagation in an infinitely long thermoelastic, isotropic micropolar plate, when the generalized theory of Lord–Shulman (L–S) is considered. A more general dispersion equation is obtained. The different analytic expressions in symmetric and anti-symmetric vibration for short as well as long waves are obtained in different regions of phase velocities. It is found that results agree with that of the existing results predicted by Sharma and Eringen in the context of various theories of classical as well as micropolar thermoelasticity.

  10. Three-dimensional analysis of a thick FGM rectangular plate in thermal environment

    Institute of Scientific and Technical Information of China (English)

    陈伟球; 边祖光; 丁皓江

    2003-01-01

    The thermal behavior of a thick transversely isotropic FGM rectangular plate was investigated within the scope of three-dimensional elasticity. Noticing many FGMs may have temperature-dependent properties, the material constants were further considered as functions of temperature. A solution method based on state-space formulations with a laminate approximate model was proposed. For a thin plate, the method was clarified by comparison with the thin plate theory. The influences of material inhomogeneity and temperature-dependent characteristics were finally discussed through numerical examples.

  11. Thermal stability analysis of eccentrically stiffened Sigmoid-FGM plate with metal–ceramic–metal layers based on FSDT

    Directory of Open Access Journals (Sweden)

    Pham Hong Cong

    2016-12-01

    Full Text Available This paper researches the thermal stability of eccentrically stiffened plates made of functionally graded materials (FGM with metal–ceramic–metal layers subjected to thermal load. The equilibrium and compatibility equations for the plates are derived by using the first-order shear deformation theory of plates, taking into account both the geometrical nonlinearity in the von Karman sense and initial geometrical imperfections with Pasternak type elastic foundations. By applying Galerkin method and using stress function, effects of material and geometrical properties, elastic foundations, temperature-dependent material properties, and stiffeners on the thermal stability of the eccentrically stiffened S-FGM plates in thermal environment are analyzed and discussed.

  12. Study On the Performance of Solar Air Collectors with Cross V-Shaped Absorbing Plate and V-Shaped Bottom Plate%交叉V形吸热板V形底板空气集热器性能特性研究

    Institute of Scientific and Technical Information of China (English)

    闫崇强; 李明; 季旭; 罗熙

    2013-01-01

    以两种不同的交叉V形吸热板V形底板空气集热器(垂直型集热器:V形吸热板的方向与流道方向垂直,V形底板的方向与流道方向平行;平行型集热器:V形吸热板的方向与流道方向平行,V形底板的方向与流道方向垂直)为研究对象,对不同倾角、不同空气流速下两种空气集热器的性能进行了比较实验研究,同时对正向和反向通气时垂直型空气集热器的性能进行了测试分析.结果表明:垂直型空气集热器的性能优于平行型空气集热器,45°倾角时两台集热器的温升最高;垂直型和平行型空气集热器的最大效率分别为71%,68%;垂直型空气集热器反向流动时比正向流动时性能更好.%Two different types of solar air collectors with cross V-shaped absorbing plate and V-shaped bottom plate (for the vertical type collector,the direction of the V-shaped bottom plate is parallel to the flow direction while the direction of the V-shaped absorbing plate is perpendicular to it; for the parallel type collector,the direction of the V-shaped absorbing plate is parallel to the flow direction while the direction of the V-shaped bottom plate is perpendicular to it) are used as the research object in this paper,and their performances are studied and compared under different dip angle and different air flow velocity; meanwhile,the performance of the vertical type air collector is tested and analysed under forward and reverse entilation.The results show that the performance of the vertical type air collector is better than that of the parallel type air collector,and the rise of temperature of both collectors is the highest with an angle of 45°.The maximum efficiency of the vertical and the parallel type is 71% and 68%,respectively.With a reverse flow,the performance of the vertical type air collector is better than with a forward flow.

  13. 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....

  14. A Long Term Test of Differently Designed Evacuated Tubular Collectors

    DEFF Research Database (Denmark)

    Fan, Jianhua; Dragsted, Janne; Furbo, Simon

    2008-01-01

    carried out with different mean solar collector fluid temperatures and in different seasons of the year. The results of the measurements are presented in this paper. The influence of the mean solar collector fluid temperature on the thermal performance of the different collector designs will be discussed......During three years seven differently designed evacuated tubular collectors (ETCs) utilizing solar radiation from all directions have been investigated experimentally. The evacuated tubular solar collectors investigated include one SLL all-glass ETC from Tshinghua Solar Co. Ltd, four heat pipe ETCs...... of the inlet fluid to the collectors have been the same for all collectors. The volume flow rate through each of the collectors is adjusted so that the mean solar collector fluid temperature has been the same for all collectors. Thus a direct performance comparison is possible. The side-by-side tests were...

  15. Evaluation of high performance evacuated tubular collectors in a residential heating and cooling system: Colorado State University Solar House I. Report for October 1, 1976--September 30, 1977

    Energy Technology Data Exchange (ETDEWEB)

    Duff, W.S.; Conway, T.M.; Loef, G.O.G.; Meredith, D.B.; Pratt, R.B.

    1978-03-01

    CSU Solar House I is configured with a prototype Corning evacuated tubular collector and a new Arkla lithium bromide water chiller designed for solar operation. Data have been collected for this configuration since January 1977. Prior to that time and since mid-1974, Solar House I has operated with a flat-plate collector and a previous Arkla LiBr air conditioner modified to operate in the lower solar temperature ranges. Project objectives were to develop an operating and control system for the new configuration and to compare the performance of the new residential solar heating, cooling, and hot water system with performance of the previous system. Many problems were encountered in the evolution of the operating and control systems due to the different operating characteristics of evacuated tubular collectors, such as their rapid thermal response and the possibility of much higher temperatures as compared to a flat-plate collector.

  16. Thermal Hydraulic Characteristics of Fuel Defects in Plate Type Nuclear Research Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Bodey, Isaac T [ORNL

    2014-05-01

    Turbulent flow coupled with heat transfer is investigated for a High Flux Isotope Reactor (HFIR) fuel plate. The Reynolds Averaged Navier-Stokes Models are used for fluid dynamics and the transfer of heat from a thermal nuclear fuel plate using the Multi-physics code COMSOL. Simulation outcomes are compared with experimental data from the Advanced Neutron Source Reactor Thermal Hydraulic Test Loop. The computational results for the High Flux Isotope Reactor core system provide a more physically accurate simulation of this system by modeling the turbulent flow field in conjunction with the diffusion of thermal energy within the solid and fluid phases of the model domain. Recommendations are made regarding Nusselt number correlations and material properties for future thermal hydraulic modeling efforts

  17. Thermal Stresses in an Anisotropic Thin Plate Subjected to Moving Plane Heat Sources

    Directory of Open Access Journals (Sweden)

    Malak Naji

    2014-04-01

    Full Text Available The aim of this study is to numerically simulate the plane moving heat source through anisotropic mild steal thin plate. Heat conduction problems in anisotropic material, where the thermal conductivity varies with direction and involving a moving heat source have several industrial applications, such like metal cutting, flame or laser hardening of metals, welding and others. The parabolic heat conduction model is used for the prediction of the temperature history. The temperature distribution inside the plate is determined from the solution of heat equation. Thus, the heat equation is solved numerically using finite deference method and the temperature distributions are determined. The thermal stresses in this case are, also, investigated and computed numerically. It is found that the thermal conductivity ratio affect in both temperature and thermal stresses distributions, in additional to the speed and heat source intensity.

  18. 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.

  19. Aid To Solar Collector Development

    Science.gov (United States)

    1979-01-01

    Solar heating and cooling systems employ coatings to increase efficiency. Designers want a coating which absorbs solar heat to the maximum extent possible with minimal emittance of infrared radiation, which occurs when the collector plate gets hot. The coating is important because too much coating causes energy loss by emittance, too little reduces the collector's ability to absorb heat. NASA's Lewis Research Center, which conducts solar energy research, saw a need for a simple means of testing coating samples for emittance. Such equipment is available to research laboratories, but it is complex and expensive

  20. Experimental investigation of thermal loading of a horizontal thin plate using infrared camera

    Directory of Open Access Journals (Sweden)

    M.Y. Abdollahzadeh Jamalabadi

    2014-07-01

    Full Text Available This study reports the results of experimental investigations of the characteristics of thermal loading of a thin plate by discrete radiative heat sources. The carbon–steel thin plate is horizontally located above the heat sources. Temperature distribution of the plate is measured using an infrared camera. The effects of various parameters, such as the Rayleigh number, from 107 to 1011, the aspect ratio, from 0.05 to 0.2, the distance ratio, from 0.05 to 0.2, the number of heaters, from 1 to 24, the thickness ratio, from 0.003 to 0.005, and the thermal radiative emissivity, from 0.567 to 0.889 on the maximum temperature and the length of uniform temperature region on a thin plate are explored. The results indicate that the most effective parameters on the order of impact on the maximum temperature is Rayleigh number, the number of heat sources, the distance ratio, the aspect ratio, the surface emissivity, and the plate thickness ratio. Finally, the results demonstrated that there is an optimal distance ratio to maximize the region of uniform temperature on the plate.

  1. Design and evaluation of a computer controlled solar collector simulator

    Science.gov (United States)

    Kotas, J. F.; Wood, B. D.

    1980-11-01

    A computer-controlled system has been developed to simulate the thermal processes of a flat-plate solar collector. The simulator is based on four water heaters of capacities of 1.5, 2.5, 5.0 and 5.0 kW providing a maximum design output of 14.0 kW which are controlled by a Nova 3 minicomputer, which also monitors temperatures in the fluid stream. Measurements have been obtained of the steady-state operating values and time constants of the individual heaters at different flow rates in order to utilize effectively their thermal outputs. Software was designed to control the heater system so the total thermal output closely approximates that of an actual heater array, utilizing steady-state or dynamic control modes. Simulation of the heat output of a previously tested collector has resulted in simulated values differing from actual output by a maximum of 3% under identical operating conditions, thus indicating that the simulator represents a viable alternative to the testing of a large field of collectors.

  2. ANALYSIS OF SHAKEDOWN OF FG BREE PLATE SUBJECTED TO COUPLED THERMAL-MECHANICAL LOADINGS

    Institute of Scientific and Technical Information of China (English)

    Xianghe Peng; Ning Hu; Hengwei Zheng; Cuirong Fang

    2009-01-01

    The static and kinematic shakedown of a functionally graded (FG) Bree plate is analyzed. The plate is subjected to coupled constant mechanical load and cyclically varying tem-perature. The material is assumed linearly elastic and nonlinear isotropic hardening with elastic modulus, yield strength and the thermal expansion coefficient varying exponentially through the thickness of the plate. The boundaries between the shakedown area and the areas of elasticity, incremental collapse and reversed plasticity are determined, respectively. The shakedown of the counterpart made of homogeneous material with average material properties is also analyzed. The comparison between the results obtained in the two cases exhibits distinct qualitative and quantitative difference, indicating the importance of shakedown analysis for FG structures. Since FG structures are usually used in the cases where severe coupled cyclic thermal and mechani-cal loadings are applied, the approach developed and the results obtained are significant for the analysis and design of such kind of structures.

  3. Thermal deformation in a thin circular plate due to a partially distributed heat supply

    Indian Academy of Sciences (India)

    N L Khobragade; K C Deshmukh

    2005-08-01

    In this paper, we develop an integral transform to determine temperature distribution in a thin circular plate, subjected to a partially distributed and axisymmetric heat supply on the curved surface, and study the thermal deformation. The results, obtained in series form in terms of Bessel’s functions, are illustrated numerically.

  4. Buckling of laminated composite plates subjected to mechanical and thermal loads using meshless collocations

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Sandeep; Shukla, K. K. [Motilal Nehru National Institute of Technology, Allahabad (India); Shingh, Jeeoot [Department of Mechanical Engineering, Birla Institute of Technology Mesra, Ranchi (India)

    2013-02-15

    Meshless collocations utilizing Gaussian and Multi quadric radial basis functions for the stability analysis of orthotropic and cross ply laminated composite plates subjected to thermal and mechanical loading are presented. The governing differential equations of plate are based on higher order shear deformation theory considering two different transverse shear stress functions. The plate governing differential equations are discretized using radial basis functions to cast a set of simultaneous equations. The convergence of both radial basis functions is studied for different values of shape parameters. Several numerical examples are undertaken to demonstrate the accuracy of present method and the effects of orthotropy ratio of the material, span to thickness ratio of the plate, and fiber orientation on critical load/temperature are also presented.

  5. Developments of solar collectors in China

    Institute of Scientific and Technical Information of China (English)

    Yin Zhiqiang

    2009-01-01

    China has abundant solar energy resource. Solar thermal collectors, particularly all-glass evacuated tubular collectors, have been studied and developed for 30 years, and solar thermal industry has developed rapidly for 15 years. There are various solar thermal systems, with an operation area of around 108 million m2 in 2007. These systems mainly provide domestic hot water, but some other applications are under extensive study and development as well.

  6. 空气-水复合平板型太阳能集热器%Experiment test of hybrid air-water solar flat plate collector

    Institute of Scientific and Technical Information of China (English)

    赵东亮; 代彦军; 李勇

    2011-01-01

    This paper focuses on a new type of solar collector that has the potential for using in solar heating systems. It can use both air and water as the circulation mediums. Experiment results show that the collector efficiency is between 55%~65% when air is used as the circulation medium, while the efficiency is between 32%~34% for using water as the circulation medium, and it can meet the requirement of solar heating systems. Moreover, this collector is fairly cheap, therefore, especially suitable for the rural areas in north China.%提出了一种适用于太阳能供热采暖工程的新型太阳能空气-水复合平板集热器.该集热器可以单独使用空气、水或同时以空气和水作为集热工质.测试显示,该集热器空气循环集热效率为55%~65%,水循环集热效率为32%~34%,能够满足太阳能供热采暖工程的要求.该集热器成本不高,适用于在我国北方广大农村地区推广使用.

  7. Midtemperature solar systems test facility predictions for thermal performance based on test data: Alpha Solarco 104 solar collector with 0.125-inch Schott low-iron glass reflector surface

    Science.gov (United States)

    Harrison, T. D.

    1981-04-01

    Thermal performance predictions based on test data are presented for the Alpha Solarco Model 104 solar collector, with a 0.125-inch Schott low-iron glass reflector surface, for three output temperatures at five cities in the United States.

  8. Comparison of plate and asthenospheric flow models for the thermal evolution of oceanic lithosphere

    Science.gov (United States)

    Stein, Carol A.; Stein, Seth

    1994-04-01

    Although seafloor depth and heat flow for young oceanic lithosphere can be descibed by modeling the lithosphere as the boundary layer of a cooling halfspace, a long standing question has been why data at older ages deviate from those expected for a halfspace. Two classes of models have been proposed for these deviations. In one, heat added from below 'flattens' depth and heat flow. In the other, asthenospheric flow beneath the lithosphere perturbs the depths. We compare recent versions of the model classes: the GDH1 thin-lithosphere plate model (Stein and Stein, 1992) and an asthenospehric flow model (Phipps Morgan and Smith, 1992). The plate model fits heat flow data better than the flow model for all cases considered, and topographic data in all but one case. The flow model significantly overpredicts depths for the North Atlantic, because the assumed asthenospheric flow in the plate motion direction would yield deepening for old ages rather than the observed flattening. Overall, the GDH1 global average model does better than this flow model, whose parameters were fit to specific plates. Moreover, the plate models fit to specific plates do better than the flow model. Plate models thus appear more useful than this flow model, suggesting that deviations from a cooling halfspace are largely thermal in origin.

  9. Polarization characterization of PZT disks and of embedded PZT plates by thermal wave methods

    Energy Technology Data Exchange (ETDEWEB)

    Eydam, Agnes, E-mail: Agnes.Eydam@tu-dresden.de; Suchaneck, Gunnar, E-mail: Agnes.Eydam@tu-dresden.de; Gerlach, Gerald [Technische Universität Dresden, Solid State Electronics Laboratory, Helmholtzstraße 18, 01062 Dresden (Germany); Esslinger, Sophia; Schönecker, Andreas; Neumeister, Peter [Fraunhofer Institute for Ceramic Technologies and Systems, Winterbergstraße 28, 01277 Dresden (Germany)

    2014-11-05

    In this work, the thermal wave method was applied to characterize PZT disks and embedded PZT plates with regard to the polarization magnitude and spatial homogeneity. The samples were exposed to periodic heating by means of a laser beam and the pyroelectric response was determined. Thermal relaxation times (single time constants or distributions of time constants) describe the heat losses of the PZT samples to the environment. The resulting pyroelectric current spectrum was fitted to the superposition of thermal relaxation processes. The pyroelectric coefficient gives insight in the polarization distribution. For PZT disks, the polarization distribution in the surface region showed a characteristic decrease towards the electrodes.

  10. Using the heat flow plate method for determining thermal conductivity of building materials

    Science.gov (United States)

    Flori, M.; Puţan, V.; Vîlceanu, L.

    2017-01-01

    The heat flow plate method is used to determine thermal conductivity of a building material sample made of Rohacell (insulating foam). Experimental technique consists in placing the sample with a reference material on top (polystyrene sample) in a calorimetric chamber and heating from underside. Considering that the heat flux which passes through the two layers is constant and knowing thermal conductivity of the reference material, the sample thermal conductivity is determined. The temperature difference between the two opposite sample’s sides is recorded only when the steady state is achieved (constant heat flux).

  11. Architectural integration of solar thermal systems and photovoltaic: study of Spanish legislation by thermal collectors in buildings; Integracion arquitectonica de sistemas solares termicos y fotovoltaicos: estudio de la legislacion espanola sobre captadores termicos en edificios

    Energy Technology Data Exchange (ETDEWEB)

    Bosqued, G. R.; Heras, C. M. R.

    2004-07-01

    In this article the legal dispositions are studied relating to architectural integration and urban landscape, considered in the different mandatories and Spanish local legislation on the use of thermal solar systems in construction, new and rehabilitated. As consequence some of the multiple possibilities that exist, are analyzed to place the external part of the system, the solar collectors, in the envelop of the building, without any aesthetic reduction on the building and urban set, and in this way fulfill with specified in the normative to contribute to a bigger respect to the environment. (Author)

  12. TEMPERATURE PROFILES OF LOCAL THERMAL NONEQUILIBRIUM FOR THERMAL DEVELOPING FORCED CONVECTION IN POROUS MEDIUM PARALLEL PLATE CHANNEL

    Institute of Scientific and Technical Information of China (English)

    YANG Xiao; LIU Xue-mei

    2006-01-01

    Based on the two-energy equation model, taking into account viscous dissipation due to the interaction between solid skeleton and pore fluid flow, temperature expressions of the solid skeleton and pore fluid flow are obtained analytically for the thermally developing forced convection in a saturated porous medium parallel plate channel,with walls being at constant temperature. It is proved that the temperatures of the two phases for the local thermal nonequilibrium approach to the temperature derived from the one-energy equation model for the local thermal equilibrium when the heat exchange coefficient goes to infinite. The temperature profiles are shown in figures for different dimensionless parameters and the effects of the parameters on the local thermal nonequilibrium are revealed by parameter study.

  13. Parametric Influence on Thermal Performance of Flat Plate Closed Loop Pulsating Heat Pipes

    Institute of Scientific and Technical Information of China (English)

    YANG Hong-hai; KHANDEKAR Sameer; GROLL Manfred

    2006-01-01

    This paper presents an experimental study on a flat plate closed loop pulsating heat pipes. It consisted of total 40 channels with square cross section (2 × 2 mm2, 165 mm long) machined directly on an aluminum plate(180× 120×3mm3 ), which was covered by a transparent plate. The working fluid employed was ethanol. As the results, the influence parameters of thermal performance were investigated, such as filling ratio, heat load and operational orientations etc. Filling ratio was found to be a critical parameter, and its effect was rather complicated. According to its values the PHP plate could have four distinct working zones with different operational characteristics and heat transfer performance. The effect of heat load on thermal performance was found to be positive, and in general,increasing the heat load would improve heat transfer performance. In order to analyze the effect of gravity on thermal performance, three different heat modes and total seven tilt angles were tested and compared. Successful operation at all orientations with respect to gravity was also achieved.

  14. Tectonic plates, D (double prime) thermal structure, and the nature of mantle plumes

    Science.gov (United States)

    Lenardic, A.; Kaula, W. M.

    1994-01-01

    It is proposed that subducting tectonic plates can affect the nature of thermal mantle plumes by determining the temperature drop across a plume source layer. The temperature drop affects source layer stability and the morphology of plumes emitted from it. Numerical models are presented to demonstrate how introduction of platelike behavior in a convecting temperature dependent medium, driven by a combination of internal and basal heating, can increase the temperature drop across the lower boundary layer. The temperature drop increases dramatically following introduction of platelike behavior due to formation of a cold temperature inversion above the lower boundary layer. This thermal inversion, induced by deposition of upper boundary layer material to the system base, decays in time, but the temperature drop across the lower boundary layer always remains considerably higher than in models lacking platelike behavior. On the basis of model-inferred boundary layer temperature drops and previous studies of plume dynamics, we argue that generally accepted notions as to the nature of mantle plumes on Earth may hinge on the presence of plates. The implication for Mars and Venus, planets apparently lacking plate tectonics, is that mantle plumes of these planets may differ morphologically from those of Earth. A corollary model-based argument is that as a result of slab-induced thermal inversions above the core mantle boundary the lower most mantle may be subadiabatic, on average (in space and time), if major plate reorganization timescales are less than those acquired to diffuse newly deposited slab material.

  15. Solar Thermal Radiant Heating at Pohakuloa Training Area

    Science.gov (United States)

    2010-06-01

    Solar collector panels. • Sizing the array: Using thermal storage of 256,000 BTU/day and 4’ x 10’ flat panel collectors with output of...be arranged side-by-side on the south- facing pitch of roof. – Racked at 30 angle to maximize winter sun. Flat plate solar collectors E2S2– June 2010...radiant heat flooring project will combine solar thermal hot water system with in-floor radiant heating. – Flooring heat only; no domestic water. – Flat

  16. Complex dynamics of functionally graded plates with thermal load in 1:2 internal resonance

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Complex dynamics of the simply-supported functionally graded(FG)rectangular plates with thermal load is investigated.Based on Reddy’s third-order shear deformation theory and the von Karman nonlinear strain-displacement relations,ordinary differential equations(ODEs)of the plate’s transversal oscillation are derived by using Hamilton’s principle and Galerkin’s approach.Solutions’classification of the equations in 1:2 internal resonance is analyzed.Particular results of a simplysupported aluminum-alumina rectangular FG plate are given.Effects of temperature and volume fraction on the responses’ stabilities are discussed.

  17. Evaluation of Test Method for Solar Collector Efficiency

    DEFF Research Database (Denmark)

    Fan, Jianhua; Shah, Louise Jivan; Furbo, Simon

    /S. The solar collector panel investigated has 16 parallel connected horizontal absorber fins. CFD (Computational Fluid Dynamics) simulations, calculations with a solar collector simulation program SOLEFF (Rasmussen and Svendsen, 1996) and thermal experiments are carried out in the investigation......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...

  18. General solution of collector performance with axial conduction and end effects

    Science.gov (United States)

    Shouman, A. R.; Tag, I. A.

    The Phillips solution of the flat-plate solar collector is extended and utilized to examine the influence of the end losses on collector performance. The results of this study show that the influence of the end temperatures of the absorber plate is more significant than the losses due to the axial conductivity of an insulated end collector plate. It will be shown that for an insulated end collector, the loss in the heat removal factor due to axial conductivity is negligible in the region of interest for flat-plate collectors. However, the end temperatures of the collector plate have more significant influence on the same factor, showing losses in some regions and improvements in other regions. This study emphasizes the necessity of measuring the temperature of the absorber plate at both the fluid inlet and exit locations in order to determine accurately the collector performance parameters.

  19. Thermal modeling of a combined system of photovoltaic thermal (PV/T) solar water heater

    Energy Technology Data Exchange (ETDEWEB)

    Dubey, Swapnil; Tiwari, G.N. [Centre for Energy Studies, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016 (India)

    2008-07-15

    In this paper, an integrated combined system of a photovoltaic (glass-glass) thermal (PV/T) solar water heater of capacity 200 l has been designed and tested in outdoor condition for composite climate of New Delhi. An analytical expression for characteristic equation for photovoltaic thermal (PV/T) flat plate collector has been derived for different condition as a function of design and climatic parameters. The testing of collector and system were carried out during February-April, 2007. It is observed that the photovoltaic thermal (PV/T) flat plate collector partially covered with PV module gives better thermal and average cell efficiency which is in accordance with the results reported by earlier researchers. (author)

  20. Thermal Effects on Vibration and Control of Piezocomposite Kirchhoff Plate Modeled by Finite Elements Method

    Directory of Open Access Journals (Sweden)

    M. Sanbi

    2015-01-01

    Full Text Available Theoretical and numerical results of the modeling of a smart plate are presented for optimal active vibration control. The smart plate consists of a rectangular aluminum piezocomposite plate modeled in cantilever configuration with surface bonded thermopiezoelectric patches. The patches are symmetrically bonded on top and bottom surfaces. A generic thermopiezoelastic theory for piezocomposite plate is derived, using linear thermopiezoelastic theory and Kirchhoff assumptions. Finite element equations for the thermopiezoelastic medium are obtained by using the linear constitutive equations in Hamilton’s principle together with the finite element approximations. The structure is modelled analytically and then numerically and the results of simulations are presented in order to visualize the states of their dynamics and the state of control. The optimal control LQG-Kalman filter is applied. By using this model, the study first gives the influences of the actuator/sensor pair placement and size on the response of the smart plate. Second, the effects of thermoelastic and pyroelectric couplings on the dynamics of the structure and on the control procedure are studied and discussed. It is shown that the effectiveness of the control is not affected by the applied thermal gradient and can be applied with or without this gradient at any time of plate vibrations.

  1. Comparison between a simple solar collector accumulator and a conventional accumulator

    Energy Technology Data Exchange (ETDEWEB)

    Fasulo, AmIlcar [University National of San Luis, San Luis (Argentina); University National of Rio IV, Rio Cuarto (Argentina); Follari, Jorge [University National of San Luis, San Luis (Argentina); Barral, Jorge [University National of Rio IV, Rio Cuarto (Argentina)

    2001-07-01

    In dry regions with abundant solar radiation at Southern latitudes between 30 and 40deg, such as the central-western part of Argentina, it is possible to obtain domestic hot water by means of simple integral collector accumulator systems, which are less expensive than the classical flat plate active systems. The experimental assessment of two solar accumulator collector systems yielding 300 1 of hot water daily is reported in this work. Daily diurnal global efficiency and nocturnal thermal losses have been systematically determined over a 5-month period, from austral summer to austral winter. The results of these systems were compared with the results obtained from a high quality thermosyphon solar system composed of a flat plate collector and its corresponding insulated storage tank, tested at the same time. The experiments were carried out by measuring the climatic variables, temperatures in different parts of the collectors, and mass flow rates of water, during the test days. Based on these measurements, the behaviour of the systems was analysed by comparing exit temperatures, heat losses, and delivered useful energy. An economic evaluation was made considering the investment time recovery through the savings the system could provide working with different conventional sources of energy. The systems proved to work efficiently, although some improvements should be made on the semitransparent thermal insulation in order to enhance its winter performance. (Author)

  2. Microscopic studies of the influence of main exposure time on parameters of flexographic printing plate produced by digital thermal method.

    Science.gov (United States)

    Harri, Liliya

    2009-10-01

    The digital thermal technology of producing flexographic printing plates from photopolymer plates is one of the newest technologies. This technology allows to develop flexographic plates without the use of any solvent. The process of producing flexographic printing plates by the digital thermal method consists of several main stages: back exposure, laser exposure, main exposure, thermal development, post exposure, and light finishing. The studies carried out with the use of optical stereoscopic microscopy allowed to determine the effect of time of main exposure to ultraviolet radiation on the dot area, diameter, and edge factor of halftone dots reproduced on flexographic printing plate produced by the digital thermal method, as well as on the quality of reproducing the surface and on the profiles of free-standing printing microelements. The results of the microscopic studies performed have allowed to define the criteria of establishing optimum time of main exposure of photopolymer plates used in the digital thermal technology of producing flexographic printing plates. A precise definition of the criteria for determining the optimum time of main exposure will enable to reduce the time-consuming control tests and to eliminate errors in both the process of manufacturing flexographic printing plates and in the printing process carried out with the use of such plates.

  3. Shrinking of the Cocos and Nazca Plates due to Horizontal Thermal Contraction and Implications for Plate Non-rigidity and the Non-closure of the Pacific-Cocos-Nazca Plate Motion Circuit

    Science.gov (United States)

    Gordon, R. G.; Kreemer, C.

    2015-12-01

    Plate rigidity is the central tenet of plate tectonics. Mounting evidence suggests, however, that significant intraplate deformation occurs in oceanic lithosphere due to horizontal thermal contraction, the rate of which decreases as ≈ 1/age [Kumar & Gordon 2009]. Support for this hypothesis comes from the azimuths of submarine transform faults, which are fit significantly better assuming shrinking plates than by assuming rigid plates [Mishra & Gordon 2015]. Previously we estimated the intraplate velocity field of the Pacific plate accounting for horizontal thermal contraction. The ≈2 mm/yr southeastward motion predicted for the northeastern part of the plate relative to the Pacific-Antarctic Rise may contribute to the non-closure of the Pacific-North America plate motion circuit. In a reference frame in which fix the oldest portion of the Pacific plate, some sites on the plate move up to ≈2 mm/yr [Kreemer & Gordon 2014]. Here we present intraplate velocity fields of the Cocos and Nazca plates and discuss their implications for the non-rigidity of plates and the non-closure of the Pacific-Cocos-Nazca plate circuit, which fails closure by a stunning 14 ±5 mm/yr [DeMets et al. 2010]. If we fix the oldest part of the Cocos plate, intraplate velocities of up to ≈2 mm/yr are estimated, with the fastest motion occurring at the northern end of the plate. If we fix the oldest part of the Nazca plate, displacement rates up to 2 mm/yr are estimated, with the fastest motion occurring in the northeasternmost portion of the plate. In the velocity fields for both plates, the lithosphere adjacent to transform faults along the East Pacific Rise tends to move to the south, which would skew the azimuths of the transform faults clockwise of the values expected for rigid plates, which is the same as the sense of misfit between observed azimuths of transform faults and the azimuths calculated from the MORVEL global set of relative angular velocities [DeMets et al. 2010]. Direct

  4. Simple, economical solar collector

    Science.gov (United States)

    Anthony, K.

    1979-01-01

    Hot air solar collector designed for economy and simplicity is assembled from only three parts: (1) molded urethane foam body, (2) flat sheet metal collector panel and (3) transparent cover. Large arrays may be assembled by inserting male fittings of each collector into female fitting of adjacent collector.

  5. Concentrating solar collector-performance tests

    Science.gov (United States)

    1979-01-01

    Report summarizes test results from evaluation of concentrating solar collector thermal performance, from transient behavior, and incident-of-angle behavior. Tests were conducted using National Bureau of Standards recommedations and specifications.

  6. Experimental investigation of efficiency of a novel conical solar collector

    OpenAIRE

    MORAVEJ, M

    2015-01-01

    One of the methods to improvement of solar-to-thermal energy conversion is the design of geometry in solar collectors. In this paper, the new solar collector which is called solar conical collector has been designed and tested. The efficiency of solar conical collector was experimentally investigated by use of ASHRAE standard. Experiments were performed with water as a working fluid in the outdoor condition of Ahvaz city in the south of Iran. The results show that the average efficiency of a ...

  7. Simulation and Experimental Investigation of Thermal Performance of a Miniature Flat Plate Heat Pipe

    Directory of Open Access Journals (Sweden)

    R. Boukhanouf

    2013-01-01

    Full Text Available This paper presents the results of a CFD analysis and experimental tests of two identical miniature flat plate heat pipes (FPHP using sintered and screen mesh wicks and a comparative analysis and measurement of two solid copper base plates 1 mm and 3 mm thick. It was shown that the design of the miniature FPHP with sintered wick would achieve the specific temperature gradients threshold for heat dissipation rates of up to 80 W. The experimental results also revealed that for localised heat sources of up to 40 W, a solid copper base plate 3 mm thick would have comparable heat transfer performances to that of the sintered wick FPHP. In addition, a marginal effect on the thermal performance of the sintered wick FPHP was recorded when its orientation was held at 0°, 90°, and 180° and for heat dissipation rates ranging from 0 to 100 W.

  8. Modelling Thermal Shock in Functionally Graded Plates with Finite Element Method

    Directory of Open Access Journals (Sweden)

    Vyacheslav N. Burlayenko

    2016-01-01

    Full Text Available Thermomechanical behavior and crack propagation in a functionally graded metal/ceramic plate undergoing thermal shock are analyzed by using the finite element method. A two-dimensional plane strain functionally graded finite element has been developed within the ABAQUS software environment for this purpose. An actual material gradation has been accomplished by sampling material quantities directly at the Gauss points of the element via programming appropriate user-defined subroutines. The virtual crack closure technique is used to model a crack growth under thermal loading. Contact possible between crack lips during the crack advance is taken into account in thermomechanical simulations as well. The paper shows that the presented finite element model can be applied to provide an insight into the thermomechanical respond and failure of the metal/ceramic plate.

  9. An efficient plate heater with uniform surface temperature engineered with effective thermal materials

    CERN Document Server

    Liu, Yichao; He, Sailing; Ma, Yungui

    2014-01-01

    Extended from its electromagnetic counterpart, transformation thermodynamics applied to thermal conduction equations can map a virtual geometry into a physical thermal medium, realizing the manipulation of heat flux with almost arbitrarily desired diffusion paths, which provides unprecedented opportunities to create thermal devices unconceivable or deemed impossible before. In this work we employ this technique to design an efficient plate heater that can transiently achieve a large surface of uniform temperature powered by a small thermal source. As opposed to the traditional approach of relying on the deployment of a resistor network, our approach fully takes advantage of an advanced functional material system to guide the heat flux to achieve the desired temperature heating profile. A different set of material parameters for the transformed device has been developed, offering the parametric freedom for practical applications. As a proof of concept, the proposed devices are implemented with engineered therm...

  10. Standard Practice for Evaluating Solar Absorptive Materials for Thermal Applications

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This practice covers a testing methodology for evaluating absorptive materials used in flat plate or concentrating collectors, with concentrating ratios not to exceed five, for solar thermal applications. This practice is not intended to be used for the evaluation of absorptive surfaces that are (1) used in direct contact with, or suspended in, a heat-transfer liquid, (that is, trickle collectors, direct absorption fluids, etc.); (2) used in evacuated collectors; or (3) used in collectors without cover plate(s). 1.2 Test methods included in this practice are property measurement tests and aging tests. Property measurement tests provide for the determination of various properties of absorptive materials, for example, absorptance, emittance, and appearance. Aging tests provide for exposure of absorptive materials to environments that may induce changes in the properties of test specimens. Measuring properties before and after an aging test provides a means of determining the effect of the exposure. 1.3 Th...

  11. Experimental and CFD analyses of a thermal radiation shield dimple plate for cryogenic pump application

    Science.gov (United States)

    Scannapiego, M.; Day, C.

    2015-12-01

    Large customized cryogenic pumps are used in fusion reactors to evacuate the plasma exhaust from the torus. Cryopumps usually consist of an active pumping surface area cooled below 5 K and shielded from direct outer thermal radiation by plates cooled at 80K. In nuclear fusion applications, cryopumps are exposed to excessively high heat fluxes during pumping operation, and follow-up regeneration cycles with rapid warm-up and cool-down phases. Therefore, high cryogenic operational mass flows are required and thus pressure drop and heat transfer characteristics become key issues for the design of the pump cryogenic circuits. Actively cooled dimple plates are a preferred design solution for the thermal radiation shield. A test plate with a rhomb pattern of dimples has been manufactured and tested in terms of pressure drop with a dedicated test facility using water. In the present work, computational fluid dynamics (CFD) models of the test dimple plate have been performed, and computed pressure drops have been compared to experimental results. Despite the complexity of the geometry, a good agreement with the experimental results was found. Then, the validated CFD approach has been further extended to relevant operation conditions, using gaseous helium at cryogenic temperature as working fluid. The resulting pressure drop and heat transfer characteristics are finally presented.

  12. Thermal conductance of gold plated metallic contacts at liquid helium temperatures

    Science.gov (United States)

    Kittel, Peter; Spivak, Alan L.; Salerno, Louis J.

    1992-01-01

    The thermal conductance of gold plated OFHC copper, 6061-T6 aluminum, free-machining brass, and 304 stainless steel contacts has been measured over the temperature range of 1.6 to 4.2 K, with applied forces from 22 N to 670 N. The contact surfaces were prepared with a 0.8 micron lapped finish prior to gold coating. It was found that for all materials, except stainless steel, the thermal conductance was significantly improved as the result of gold coating the contact surfaces.

  13. A mobile apparatus for solar collector testing

    Science.gov (United States)

    Hotchkiss, G. B.; Simon, F. F.; Burmeister, L. C.

    1979-01-01

    The design, construction, and operation of a mobile apparatus for solar collector testing (MASCOT) is described. The MASCOT is a self-contained test unit costing about $10,000 whose only external requirement for operation is electrical power and which is capable of testing two water-cooled flat-plate solar collectors simultaneously. The MASCOT is small enough and light enough to be transported to any geographical site for outdoor tests at the location of collector usage. It has been used in both indoor solar simulator tests and outdoor tests.

  14. Numerical analysis of thermal deformation in laser beam heating of a steel plate

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Chao; Kim, Yong-Rae; Kim, Jae-Woong [Yeungnam University, Kyongsan (Korea, Republic of)

    2017-05-15

    Line heating is a widely used process for plate forming or thermal straightening. Flame heating and induction heating are the traditional heating processes used by industry for line heating. However, these two heating processes are ineffective when used on small steel plates. Thus, the laser beam heating with various power profiles were carried out in this study. A comparison of numerical simulation results and experimental results found a significant difference in the thermal deformation when apply a different power profile of laser beam heating. The one-sinusoid power profile produced largest thermal deformation in this study. The laser beam heating process was simulated by established a combined heat source model, and simulated results were compared with experimental results to confirm the model’s accuracy. The mechanism of thermal deformation was investigated and the effects of model parameters were studied intensively with the finite element method. Thermal deformation was found to have a significant relationship with the amount of central zone plastic deformation. Scientists and engineers could use this study’s verified model to select appropriate parameters in laser beam heating process. Moreover, by using the developed laser beam model, the analysis of welding residual stress or hardness could also be investigated from a power profile point of view.

  15. Thermal response simulation for tuning PID controllers in a 1016 mm guarded hot plate apparatus.

    Science.gov (United States)

    Thomas, William C; Zarr, Robert R

    2011-07-01

    A mathematical model has been developed and used to simulate the controlled thermal performance of a large guarded hot-plate apparatus. This highly specialized apparatus comprises three interdependent components whose temperatures are closely controlled in order to measure the thermal conductivity of insulation materials. The simulation model was used to investigate control strategies and derive controller gain parameters that are directly transferable to the actual instrument. The simulations take orders-of-magnitude less time to carry out when compared to traditional tuning methods based on operating the actual apparatus. The control system consists primarily of a PC-based PID control algorithm that regulates the output voltage of programmable power amplifiers. Feedback parameters in the form of controller gains are required for the three heating circuits. An objective is to determine an improved set of gains that meet temperature control criteria for testing insulation materials of interest. The analytical model is based on aggregated thermal capacity representations of the primary components and includes the same control algorithm as used in the actual hot-plate apparatus. The model, accounting for both thermal characteristics and temperature control, was validated by comparisons with test data. The tuning methodology used with the simulation model is described and results are presented. The resulting control algorithm and gain parameters have been used in the actual apparatus without modification during several years of testing materials over wide ranges of thermal conductivity, thickness, and insulation resistance values.

  16. A passive guard for low thermal conductivity measurement of small samples by the hot plate method

    Science.gov (United States)

    Jannot, Yves; Degiovanni, Alain; Grigorova-Moutiers, Veneta; Godefroy, Justine

    2017-01-01

    Hot plate methods under steady state conditions are based on a 1D model to estimate the thermal conductivity, using measurements of the temperatures T 0 and T 1 of the two sides of the sample and of the heat flux crossing it. To be consistent with the hypothesis of the 1D heat flux, either a hot plate guarded apparatus is used, or the temperature is measured at the centre of the sample. On one hand the latter method can be used only if the ratio thickness/width of the sample is sufficiently low and on the other hand the guarded hot plate method requires large width samples (typical cross section of 0.6  ×  0.6 m2). That is why both methods cannot be used for low width samples. The method presented in this paper is based on an optimal choice of the temperatures T 0 and T 1 compared to the ambient temperature T a, enabling the estimation of the thermal conductivity with a centered hot plate method, by applying the 1D heat flux model. It will be shown that these optimal values do not depend on the size or on the thermal conductivity of samples (in the range 0.015-0.2 W m-1 K-1), but only on T a. The experimental results obtained validate the method for several reference samples for values of the ratio thickness/width up to 0.3, thus enabling the measurement of the thermal conductivity of samples having a small cross-section, down to 0.045  ×  0.045 m2.

  17. Plate coil thermal test bench for the Daniel K. Inouye Solar Telescope (DKIST) carousel cooling system

    Science.gov (United States)

    Phelps, LeEllen; Murga, Gaizka; Montijo, Guillermo; Hauth, David

    2014-08-01

    Analyses have shown that even a white-painted enclosure requires active exterior skin-cooling systems to mitigate dome seeing which is driven by thermal nonuniformities that change the refractive index of the air. For the Daniel K. Inouye Solar Telescope (DKIST) Enclosure, this active surface temperature control will take the form of a system of water cooled plate coils integrated into the enclosure cladding system. The main objective of this system is to maintain the surface temperature of the enclosure as close as possible to, but always below, local ambient temperature in order to mitigate this effect. The results of analyses using a multi-layer cladding temperature model were applied to predict the behavior of the plate coil cladding system and ultimately, with safety margins incorporated into the resulting design thermal loads, the detailed designs. Construction drawings and specifications have been produced. Based on these designs and prior to procurement of the system components, a test system was constructed in order to measure actual system behavior. The data collected during seasonal test runs at the DKIST construction site on Haleakalā are used to validate and/or refine the design models and construction documents as appropriate. The test fixture was also used to compare competing hardware, software, components, control strategies, and configurations. This paper outlines the design, construction, test protocols, and results obtained of the plate coil thermal test bench for the DKIST carousel cooling system.

  18. Effect of plate bending on the Urey ratio and the thermal evolution of the mantle

    Science.gov (United States)

    Davies, Geoffrey F.

    2009-10-01

    The bending of tectonic plates as they subduct causes resistance to plate motions and mantle convection. It has been proposed that this effect could keep plate velocities relatively constant with time, and it would imply relatively high mantle temperatures through much of Earth history and relatively rapid cooling at present. It also implies a low Urey ratio, compatible with that inferred from cosmochemistry. Here it is confirmed that bending resistance only plays a significant role if plate thickness is determined mainly by dehydration stiffening accompanying melting, rather than by conductive cooling. Even then the bending resistance is quite sensitive to the radius of curvature of the subducting plate. Observed radii are generally larger than the 200 km assumed in some studies, ranging up to 600 km or more. Furthermore radii of curvature tend to adjust so as to prevent bending resistance from becoming large. When these factors are accounted for, calculations show that bending resistance is unlikely to have been a large factor through Earth history, and the thermal evolution of the mantle is unlikely to have been affected very much. The resolution of the Urey ratio problem should then be sought elsewhere.

  19. Experimental investigations of hybrid PV/Spiral flow thermal collector system performance using Al2O3/water nanofluid

    Science.gov (United States)

    Gangadevi, R.; Vinayagam, B. K.; Senthilraja, S.

    2017-05-01

    In this paper, the PV/T (Photovoltaic thermal unit) system is investigated experimentally to examine the thermal, electrical and overall efficiency by circulating Al2O3/water nanofluid of 1wt% and 2wt% with an optimum flow rate of 40L/H. The overall efficiency of PVT system is largely influenced by various factors such as heat due to photovoltaic action; energy radiated at the infrared wavelength of the solar spectrum, solar irradiance, mounting structure, tilt angle, wind speed direction, Ambient temperature and panel material composition. However, the major factor is considered in this study to extract the heat generated in the PV panel by using nanofluid as a coolant to increase the overall system efficiency. Therefore, the result shows that by using 2 wt% Al2O3/water nanofluid the electrical efficiency, thermal efficiency and overall efficiency of the PVT system enhanced by 13%, 45%, and 58% respectively compared with water.

  20. The thermal state of the Arabian plate derived from heat flow measurements in Oman and Yemen

    Science.gov (United States)

    Rolandone, Frederique; Lucazeau, Francis; Leroy, Sylvie; Mareschal, Jean-Claude; Jorand, Rachel; Goutorbe, Bruno; Bouquerel, Hélène

    2013-04-01

    The dynamics of the Afar plume and the rifting of the Red Sea and the Gulf of Aden affect the present-day thermal regime of the Arabian plate. However, the Arabian plate is a Precambrian shield covered on its eastern part by a Phanerozoic platform and its thermal regime, before the plume and rifting activities, should be similar to that of other Precambrian shields with a thick and stable lithosphere. The first heat flow measurements in the shield, in Saudi Arabia, yielded low values (35-44 mW/m2), similar to the typical shields values. Recent heat flow measurements in Jordan indicate higher values (56-66 mW/m2). As part of the YOCMAL project (YOung Conjugate MArgins Laboratory), we have conducted heat flow measurements in southern and northern Oman to obtain 10 new heat flux values in the eastern Arabian plate. We also derived 20 heat flux values in Yemen and Oman by processing thermal data from oil exploration wells. The surface heat flux in these different locations is uniformly low (45 mW/m2). The heat production in samples from the Dhofar and Socotra Precambrian basement is also low (0.7 µW/m3). Differences in heat flow between the eastern (60 mW/m2) and the western (45 mW/m2) parts of Arabia reflect differences in crustal heat production as well as a higher mantle heat flux in the west. We have calculated a steady state geotherm for the Arabian platform that intersects the isentropic temperature profile at a depth of about 150 km, consistent with the seismic observations. Seismic tomography studies of the mantle beneath Arabia also show this east-west contrast. Seismic studies have shown that the lithosphere is rather thin, 100 km or less below the shield and 150 km below the platform. The lithospheric thickness for the Arabian plate is 150 km, and the progressive thinning near the Red Sea, caused by the thermal erosion of the plume material, is too recent to be detected at the surface. The Afar plume mostly affects the base of the Arabian lithosphere along

  1. Experimental evaluation of a fixed collector employing vee-trough concentrator and vacuum tube receivers

    Science.gov (United States)

    Selcuk, M. K.

    1977-01-01

    A test bed for experimental evaluation of a fixed solar collector which combines an evacuated glass tube solar receiver with a flat plate/black chrome plated copper absorber and an asymmetric vee-trough concentrator was designed and constructed. Earlier predictions of thermal performance were compared with test data acquired for a bare vacuum tube receiver; and receiver tubes with Alzak aluminum, aluminized FEP Teflon film laminated sheet metal and second surface ordinary mirror reflectors. Test results and system economics as well as objectives of an ongoing program to obtain long-term performance data are discussed.

  2. Design and Development of Prototype Cylindrical Parabolic Solar Collector for Water Heating Application

    Directory of Open Access Journals (Sweden)

    Hrushikesh Bhujangrao Kulkarni

    2016-02-01

    Full Text Available Concentrating collectors absorbs solar energy and convert it into heat for generating hot water, steam at required temperature, which can be further used for solar thermal applications. The developing countries like India where solar energy is abundantly available; there is need to develop technology for harnessing solar energy for power production, but the main problem associated with concentrating solar power technology is the high cost of installation and low output efficiency. To solve this problem, a prototype cylindrical parabolic solar collector having aperture area of 1.89 m2 is designed and developed using low cost highly reflecting and absorbing material to reduce initial cost of project and improve thermal efficiency. ASHRAE Standard 93, 1986 was used to evaluate the thermal performance and it was observed that this system can generate hot water at an average temperature of 500C per day with an average efficiency of 49% which is considerable higher than flat plate solar collectors. Hot water produced by this system can be useful for domestic, agricultural, industrial process heat applications.Article History: Received Sept 19, 2015; Received in revised form Dec 23, 2015; Accepted February 2, 2016; Available online How to Cite This Article: Bhujangrao, K.H. (2016. Design and Development of Prototype Cylindrical Parabolic Solar Collector for Water Heating Application. International Journal of Renewable Energy Development, 5(1, 49-55 http://dx.doi.org/10.14710/ijred.5.1.49-55 

  3. Effect of operating temperature on the HWB model for solar-collector design

    Science.gov (United States)

    Huang, H.; Howell, J. R.

    1983-02-01

    The Hottel-Whillier-Bliss (HWB) Model for the thermal efficiency of a flat plate solar collector plots as a straight line in an esa/sub c/ approx. (T/sub f,in/ - T/sub a/)/g/sub s/ coordinate system under the following assumptions: (1) the effect of the thermal capacity in the collector is negligible; (2) F/sub R/, U/sub L/ are constant in the range of operating temperature. These assumptions simplify the model and make it convenient to use. Because of the intermittance of insulation and the variation of ambient temperature and wind speed, the thermal capacity of the collector may affect the transient efficiency of the collector. In addition, the values of F/sub R/ and U/sub L/ are actually not constant and cause deviation of the efficiency curve from a straight line. The concern is with the deviation of the confidence level for a specific operating range. The effect of operating temperature of the values of F/sub R/ and U/sub L/ is discussed.

  4. New method for energy prediction of solar energy collectors systems in Yemen

    Energy Technology Data Exchange (ETDEWEB)

    Almakaleh, Abdo A. [Univ. of Science and Technology, Solar Energy Center, Sana' a (Yemen)

    2008-07-01

    The design of any solar system will require the full understanding of the most influenced factors on its power generation and performance year round. Therefore, one has to consider the system components variables, namely collector types, tilts and collectors orientations to capture most of the incoming solar radiation. Direct measurements of global solar radiation do exist for a number of sites around the country for many years and can be used to derive a set of equations to predict the solar system design values and its output performance. But, the solar system power output, whether it's electric or thermal energy can be very difficult to predict in the absence of measured data and variable load's demand requirements. This paper examines the effects of solar radiation in each site on the systems power output of PV and thermal energy for different type of collectors. Using the existing data from meteorological stations to derive an accurate and simple equations with only one input variable, the monthly average clearness index to be used for the design of photovoltaic and solar thermal system power outputs for tilted flat plate, polar and two axis tracking collectors for a given site instead of existing lengthy methods of solar radiation components (direct, diffuse, and reflected radiation) for different types of collectors currently in use or computer simulations programs. The results of the new equations provide a valuable tool for solar collector designer and prediction method for the systems power outputs. Furthermore, the new equations indicate the possibility of universal applications with minimum adjustment for latitude. (orig.)

  5. High-Temperature Thermal Conductivity Measurement Apparatus Based on Guarded Hot Plate Method

    Science.gov (United States)

    Turzo-Andras, E.; Magyarlaki, T.

    2017-10-01

    An alternative calibration procedure has been applied using apparatus built in-house, created to optimize thermal conductivity measurements. The new approach compared to those of usual measurement procedures of thermal conductivity by guarded hot plate (GHP) consists of modified design of the apparatus, modified position of the temperature sensors and new conception in the calculation method, applying the temperature at the inlet section of the specimen instead of the temperature difference across the specimen. This alternative technique is suitable for eliminating the effect of thermal contact resistance arising between a rigid specimen and the heated plate, as well as accurate determination of the specimen temperature and of the heat loss at the lateral edge of the specimen. This paper presents an overview of the specific characteristics of the newly developed "high-temperature thermal conductivity measurement apparatus" based on the GHP method, as well as how the major difficulties are handled in the case of this apparatus, as compared to the common GHP method that conforms to current international standards.

  6. Duality of thermal regimes is the distinctive characteristic of plate tectonics since the Neoarchean

    Science.gov (United States)

    Brown, Michael

    2006-11-01

    Ultrahigh-temperature (UHT) granulite metamorphism is documented predominantly in the Neoarchean to Cambrian rock record, but UHT granulite metamorphism also may be inferred at depth in Cenozoic orogenic systems. The first occurrence of UHT granulite metamorphism in the record signifies a change in geodynamics that generated transient sites of very high heat flow. Many UHT granulite metamorphic belts may have developed in settings analogous to modern continental backarcs; on a warmer Earth, destruction of oceans floored by thinner lithosphere may have generated hotter backarcs than those associated with the modern Pacific ring of fire. Medium-temperature eclogite high- pressure (EHP) granulite metamorphism is documented in the Neoarchean rock record and at intervals throughout the Proterozoic and Paleozoic record. EHP granulite metamorphic belts are complementary to UHT granulite metamorphic belts in that they are generally inferred to record subduction-to-collision orogenesis. Blueschists become evident in the Neoproterozoic rock record, but lawsonite blueschist eclogite metamorphism (high pressure [HP]) and ultrahigh-pressure metamorphism (UHP) characterized by coesite or diamond are predominantly Phanerozoic phenomena. HP-UHP metamorphism registers the low thermal gradients and deep subduction of continental crust during the early stage of subduction-to-collision orogenesis. A duality of metamorphic belts—reflecting a duality of thermal regimes—appears in the record only since the Neoarchean Era. A duality of thermal regimes is the hallmark of modern plate tectonics, and the duality of metamorphic belts is the characteristic imprint of plate tectonics in the rock record. The occurrence of both UHT and EHP granulite metamorphism since the Neoarchean marks the onset of a “Proterozoic plate tectonics” regime, which evolved during a Neoproterozoic transition to the modern plate tectonics regime, characterized by colder subduction as chronicled by HP

  7. Design of plate directional heat transmission structure based on layered thermal metamaterials

    Directory of Open Access Journals (Sweden)

    L. K. Sun

    2016-02-01

    Full Text Available Invisibility cloaks based on transformation optics are often closed structures; however, such a structure limits the kinds of objects that can be placed in the cloak. In this work, we adopt a transformation thermodynamics approach to design an “open cloak”, called a plate directional heat transmission structure, which is capable of guiding heat fluxes to the flank region of the metamaterial device. The most fascinating and unique feature of the device is that the lower surface can remain at a lower temperature compared with the SiO2 aerogel thermal insulation material. Our results are expected to markedly enhance capabilities in thermal protection, thermal-energy utilization, and domains beyond. In addition to the theoretical analysis, the present design is demonstrated in numerical simulations based on finite element calculations.

  8. Abrupt thermal transition reveals hydrothermal boundary and role of seamounts within the Cocos Plate

    Science.gov (United States)

    Fisher, A. T.; Stein, C. A.; Harris, R. N.; Wang, K.; Silver, E. A.; Pfender, M.; Hutnak, M.; Cherkaoui, A.; Bodzin, R.; Villinger, H.

    2003-06-01

    New thermal data from 18-24 Ma lithosphere on the Cocos Plate delineate contrasting subsurface thermal conditions in adjacent sections of crust. Heat flow through seafloor created at the East Pacific Rise is generally suppressed by ~70% relative to conductive lithospheric cooling models, whereas heat flow through adjacent, similarly-aged lithosphere generated at the Cocos-Nazca Spreading Center is consistent with these models. The transition between thermal regimes is remarkably abrupt, only 2-5 km wide, indicating a shallow hydrothermal origin. The transition is more closely associated with differences in the distribution of basement outcrops than with tectonic boundaries, demonstrating the importance of the former in extracting heat from the lithosphere on a regional basis.

  9. Design of plate directional heat transmission structure based on layered thermal metamaterials

    Energy Technology Data Exchange (ETDEWEB)

    Sun, L. K.; Yu, Z. F.; Huang, J., E-mail: slk-0-1999@163.com [China Aerodynamics Research and Development Center, Mianyang 621000 (China)

    2016-02-15

    Invisibility cloaks based on transformation optics are often closed structures; however, such a structure limits the kinds of objects that can be placed in the cloak. In this work, we adopt a transformation thermodynamics approach to design an “open cloak”, called a plate directional heat transmission structure, which is capable of guiding heat fluxes to the flank region of the metamaterial device. The most fascinating and unique feature of the device is that the lower surface can remain at a lower temperature compared with the SiO{sub 2} aerogel thermal insulation material. Our results are expected to markedly enhance capabilities in thermal protection, thermal-energy utilization, and domains beyond. In addition to the theoretical analysis, the present design is demonstrated in numerical simulations based on finite element calculations.

  10. PLATE

    DEFF Research Database (Denmark)

    Kling, Joyce; Hjulmand, Lise-Lotte

    2008-01-01

    ’s level of English is sufficient for the increasing number of courses offered in English each semester. This paper addresses these concerns and describes a pilot project initiated in 2003 at CBS to gauge the overall English language proficiency of those teaching content courses in English. Through......Copenhagen Business School (CBS) finds itself needing to address the issue of English-medium instruction for its increasing number of foreign exchange and full degree students. With internationalisation as a main pillar of the institution’s agenda, there are concerns whether the teaching faculty...... the Project in Language Assessment for Teaching in English (PLATE) language professionals from CBS’s Language Center observe teachers and provide feedback using evaluation criteria from the Common European Framework for Reference (CEFR) supplemented by some additional criteria which take the LSP nature...

  11. PLATE

    DEFF Research Database (Denmark)

    Kling, Joyce; Hjulmand, Lise-Lotte

    2008-01-01

    Copenhagen Business School (CBS) finds itself needing to address the issue of English-medium instruction for its increasing number of foreign exchange and full degree students. With internationalisation as a main pillar of the institution’s agenda, there are concerns whether the teaching faculty......’s level of English is sufficient for the increasing number of courses offered in English each semester. This paper addresses these concerns and describes a pilot project initiated in 2003 at CBS to gauge the overall English language proficiency of those teaching content courses in English. Through...... the Project in Language Assessment for Teaching in English (PLATE) language professionals from CBS’s Language Center observe teachers and provide feedback using evaluation criteria from the Common European Framework for Reference (CEFR) supplemented by some additional criteria which take the LSP nature...

  12. Evaluation of lead isotope compositions of NIST NBS 981 measured by thermal ionization mass spectrometer and multiple-collector inductively coupled plasma mass spectrometer

    Directory of Open Access Journals (Sweden)

    Honglin Yuan

    2016-09-01

    Full Text Available Because Pb isotopes can be used for tracing, they are widely used in many disciplines. The detection and analysis of Pb isotopes of bulk samples are usually conducted using thermal ionization mass spectrometer (TIMS and multiple-collector inductively coupled plasma mass spectrometer (MC-ICP-MS, both of which need external reference materials with known isotopic compositions to correct for the mass discrimination effect produced during analysis. NIST NBS 981 is the most widely used reference material for Pb isotope analysis; however, the isotopic compositions reported by various analytical laboratories, especially those using TIMS, vary from each other. In this study, we statistically evaluated 229 reported TIMS analysis values collected by GeoReM in the last 30 years, 176 reported MC-ICP-MS analysis values, and 938 MC-ICP-MS analysis results from our laboratory in the last five years. After careful investigation, only 40 TIMS results were found to have double or triple spikes. The ratios of the overall weighted averages, 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb, obtained from 40 spiked TIMS reports and 1114 MC-ICP-MS results of NIST NBS 981 isotopes were 16.9406 ± 0.0003 (2s, 15.4957 ± 0.0002 (2s, and 36.7184 ± 0.0007 (2s, respectively.

  13. 整体式太阳能空气集热器传热性能分析%Integral Solar Air Collector of the Thermal Performance Analysis

    Institute of Scientific and Technical Information of China (English)

    吴国玉; 胡明辅; 袁江; 毕二朋

    2012-01-01

    A physical mathematical model based on steady -state assumption is developed to study the heat transfer characteristics in the integral solar air collector. Through the CFD software is applied to numerical simulation, the effect of various parameters such as the inlet air velocity, air temperature and the intensity of solar radiation of the air heater are analyzed. It is discovered that thermal efficiency increases wilh increasing air velocity and decreasing temperature of inlet air, on which the solar radiation intensity have little influence.%研究了整体式太阳能空气集热器的传热性能,建立了稳态假设下的热量传递物理数学模型;通过CFD软件计算,分析了进口空气流速、空气温度、太阳辐照强度对集热器传热性能的影响;计算结果表明:集热器的集热效率随工质流速的增大而增大、随进口温度的升高而下降、随太阳辐照度的波动很小,受太阳辐射强度的影响不大.

  14. Static & Thermal Analysis of Positive Multiple Friction Plate using FEA Package

    Directory of Open Access Journals (Sweden)

    Shaik Mohammad Ali

    2014-11-01

    Full Text Available Clutch is a mechanical device, which is used to engage or disengage the source of power from the rest of the power transmission system at the operator’s will. The clutch can connect or disconnect the driving shaft from the driven shaft when necessary. Clutches are designed to transfer maximum torque with minimum heat generation. During engagement and disengagement the two clutch discs has the sliding motion between them. The project contains that designing and analysis of two positive multi friction plates. For the designing of the friction plates 3d modeling software used and for the analysis ansys package is used. In the analysis part the two models are analyzed with different materials by conducting two types of analysis which are structural and thermal. Structural analysis is done to find out the stress values and the thermal analysis done to find out the temperature distribution on the model. By these two analysis results we are suggesting the best material to the effective model of the multiple friction plate.

  15. Thermal elasto-plastic stress analysis during laser heating of a metal plate

    Science.gov (United States)

    Chen, Yanbei; Lu, Jian; Ni, Xiaowu

    2008-03-01

    During laser heating of a metal material, the continuity of material confines its free expansion, thermal stresses arise. On one hand the thermal expansion of the heated zone of the material increases with the increase of temperature, the thermal stress level increases correspondingly; on the other hand the mechanical properties of the material will change with the increase of temperature, especially the elastic modulus, yield strength and tensile strength drop significantly, which is the so-called thermal softening problem. Due to the effect of the two factors, as the heating time or the intensity of the laser beam increases, it is possible that the stress levels of the heated zone of the material exceed the yield strength, which leads the material to come into a plastic stage. Thus, a thermal plastic problem occurs. In this study, thermal elasto-plastic stresses during laser heating of a metal plate are computed by the finite element method (FEM) based on thermal elasto-plastic constitutive theory. The mechanical behaviors of the metal material during the laser heating are analyzed. By the analysis of the results, it is found that thermal expansion leads to the increase of stress level early during the laser irradiating, and thermal softening causes the decrease of stress levels in the plastic zone and the slow growth and even decrease of stress levels in elastic zone later. The radial stresses are all compressive stresses, and the hoop stresses are compressive stresses within about the laser spot and are tensile stresses at other place. This work may be beneficial to the laser processing of metal materials.

  16. Nonlinear free flexural vibrations of functionally graded rectangular and skew plates under thermal environments

    CERN Document Server

    Sundararajan, N; Ganapathi, M; 10.1016/j.finel.2005.06.001

    2011-01-01

    The nonlinear formulation developed based on von Karman's assumptions is employed to study the free vibration characteristics of functionally graded material (FGM) plates subjected to thermal environment. Temperature field is assumed to be a uniform distribution over the plate surface and varied in the thickness direction. The material is assumed to be temperature dependent and graded in the thickness direction according to the power-law distribution in terms of volume fractions of the constituents. The effective material properties are estimated from the volume fractions and the material properties of the constituents using Mori-Tanaka homogenization method. The nonlinear governing equations obtained using Lagrange's equations of motion are solved using finite element procedure coupled with the direct iteration technique. The variation of nonlinear frequency ratio with amplitude is highlighted considering various parameters such as gradient index, temperature, thickness and aspect ratios, and skew angle. For...

  17. An Analytical Approach on Thermally Induced Vibrations of Nonhomogeneous Tapered Plate

    Directory of Open Access Journals (Sweden)

    Anupam Khanna

    2013-01-01

    Full Text Available A mathematical model to control the vibrations of a rectangular plate is constructed with an aim to assist engineers in designing and fabrication of various structures used in the field of science and technology, mostly used in satellite and aeronautical engineering. The present study is related to the analysis of free vibrations of nonhomogeneous rectangular plate clamped at all the four edges. Authors studied the bilinear effect of thickness as well as temperature variations in both and directions. Variation in Poisson's ratio is also considered linearly in -direction due to nonhomogeneity. Rayleigh-Ritz method is used to analyze the frequencies for the first two modes of vibrations for different values of thermal gradient, nonhomogeneity constant, taper constants and aspect ratio. All the numerical computations have been performed for an alloy of aluminum, that is, duralumin. All the results are presented in the form of graphs.

  18. An experimental study on the effects of the thermal barrier plating over engine fuel consumption exhaust temperature and emissions

    Directory of Open Access Journals (Sweden)

    Hüseyin Gürbüz

    2014-01-01

    Full Text Available The aim of this study, the combustion chamber elements of a one-cylinder diesel engine which is air-cooled, single-cylinder, direct injection, 4-stroke and starter motor were plated with thermal barrier plating and tested with diesel fuel between the speeds of 1600 1/min to 3200 1/min and determined the effects of the thermal barrier plating on the engine exhaust gas temperature, emissions and fuel consumption. Increase in the temperature of the exhaust gas, decrease in HC and CO emissions that are harmful to the environment and living things and improvement in fuel consumption were observed.

  19. The consequences of hotspots on continental lithosphere : a thermal case study on the Arabian Plate.

    Science.gov (United States)

    Vicente De Gouveia, S.; Besse, J.; Greff-Lefftz, M.; Frizon de Lamotte, D.; Leparmentier, F.; Lescanne, M.

    2015-12-01

    Hotspots are thermal instabilities coming from various depths in the mantle. Their activity is often revealed by surface and sub-surface phenomena such as volcanic trapps or oceanic plateaus, and volcanic island tracks on the seafloor. The two first are often linked to the eruption of a hotspot head, while the third is due to the volcanic material fed by the subsequent tail. Consequences of a hotspot tail on the oceanic lithosphere are well known, while its effect on the continental lithosphere is most often masked by the thickness of the lithosphere. The aim of our study is to try and link hotspot tracks with geological events in the continental lithosphere. Hotspot tracks are first built using a modified version of the hybrid reference frame of Seton et al. (2012), and their effect on the continental lithosphere is then evaluated using geological markers issued from petroleum wells, in particular the sedimentary record, backstripping, heat flux anomaly and temperature data. A case study is performed on the Arabian Plate, potentially crossed by two hotspots (Afar and Comores). Several W-E heat flux profiles display a large thermal anomaly close to the Red Sea, while a smaller N-S elongated heat flow anomaly more to the E suggests that a hotspot track could impact the thermal history of the Arabian plate.

  20. Vibration and Acoustic Response of Rectangular Sandwich Plate under Thermal Environment

    Directory of Open Access Journals (Sweden)

    Yuan Liu

    2013-01-01

    Full Text Available In this paper, we focus on the vibration and acoustic response of a rectangular sandwich plate which is subjected to a concentrated harmonic force under thermal environment. The critical buckling temperature is obtained to decide the thermal load. The natural frequencies and modes as well as dynamic responses are acquired by using the analytical formulations based on equivalent non-classical theory, in which the effects of shear deformation and rotational inertia are taken into account. The rise of thermal load decreases the natural frequencies and moves response peaks to the low-frequency range. The specific features of sandwich plates with different formations are discussed subsequently. As the thickness ratio of facing to core increases, the natural frequencies are enlarged, and the response peaks float to the high-frequency region. Raising the Young's modulus of the core can cause the similar trends. The accuracy of the theoretical method is verified by comparing its results with those computed by the FEM/BEM.

  1. Transient thermal hydraulic modeling and analysis of ITER divertor plate system

    Energy Technology Data Exchange (ETDEWEB)

    El-Morshedy, Salah El-Din [Argonne National Laboratory, Argonne, IL (United States); Atomic Energy Authority, Cairo (Egypt)], E-mail: selmorshedy@etrr2-aea.org.eg; Hassanein, Ahmed [Purdue University, West Lafayette, IN (United States)], E-mail: hassanein@purdue.edu

    2009-12-15

    A mathematical model has been developed/updated to simulate the steady state and transient thermal-hydraulics of the International Thermonuclear Experimental Reactor (ITER) divertor module. The model predicts the thermal response of the armour coating, divertor plate structural materials and coolant channels. The selected heat transfer correlations cover all operating conditions of ITER under both normal and off-normal situations. The model also accounts for the melting, vaporization, and solidification of the armour material. The developed model is to provide a quick benchmark of the HEIGHTS multidimensional comprehensive simulation package. The present model divides the coolant channels into a specified axial regions and the divertor plate into a specified radial zones, then a two-dimensional heat conduction calculation is created to predict the temperature distribution for both steady and transient states. The model is benchmarked against experimental data performed at Sandia National Laboratory for both bare and swirl tape coolant channel mockups. The results show very good agreements with the data for steady and transient states. The model is then used to predict the thermal behavior of the ITER plasma facing and structural materials due to plasma instability event where 60 MJ/m{sup 2} plasma energy is deposited over 500 ms. The results for ITER divertor response is analyzed and compared with HEIGHTS results.

  2. Flow Field and Thermal Analysis of the Divertor Target Plate for HL-2A Tokamak

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    In the initial phase of the physics experiment, the double-null divertor plates used consist of graphite armor tiles, Mo-alloy intermediate layers and Cu-alloy coolant tubes. In the later operating phase, tungsten will be used as armor tiles.A multi-physical field numerical analysis method is used in this paper. Its analysis model reflects more realistically the real divertor structure than other models. Two-dimensional (2D)and three-dimensional (3D) fluid flow field, temperature distribution and thermal stress analyses of the divertor plates are carried out by the ANSYS code. During the physics experimental phase with a heat flux of 1 MW/m2, a coolant velocity of 5.48 m/s, and a thermal stress of 750 kg/cm2,the graphite armor tiles successfully meet the requirements of temperature, thermal stress and sputtering erosion. The tungsten armor will be considered as a second candidate. The result of simulation can be used for upgrading the design parameters of the HL-2A poloidal divertor.

  3. Optimization of solar air collector using genetic algorithm and artificial bee colony algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Sencan Sahin, Arzu [Sueleyman Demirel University, Technology Faculty, Isparta (Turkey)

    2012-11-15

    Thermal performance of solar air collector depends on many parameters as inlet air temperature, air velocity, collector slope and properties related to collector. In this study, the effect of the different parameters which affect the performance of the solar air collector are investigated. In order to maximize the thermal performance of a solar air collector genetic algorithm (GA) and artificial bee colony algorithm (ABC) have been used. The results obtained indicate that GA and ABC algorithms can be applied successfully for the optimization of the thermal performance of solar air collector. (orig.)

  4. Static, free vibration and thermal analysis of composite plates and shells using a flat triangular shell element

    Science.gov (United States)

    Kapania, R. K.; Mohan, P.

    1996-09-01

    Finite element static, free vibration and thermal analysis of thin laminated plates and shells using a three noded triangular flat shell element is presented. The flat shell element is a combination of the Discrete Kirchhoff Theory (DKT) plate bending element and a membrane element derived from the Linear Strain Triangular (LST) element with a total of 18 degrees of freedom (3 translations and 3 rotations per node). Explicit formulations are used for the membrane, bending and membrane-bending coupling stiffness matrices and the thermal load vector. Due to a strong analogy between the induced strain caused by the thermal field and the strain induced in a structure due to an electric field the present formulation is readily applicable for the analysis of structures excited by surface bonded or embedded piezoelectric actuators. The results are presented for (i) static analysis of (a) simply supported square plates under doubly sinusoidal load and uniformly distributed load (b) simply supported spherical shells under a uniformly distributed load, (ii) free vibration analysis of (a) square cantilever plates, (b) skew cantilever plates and (c) simply supported spherical shells; (iii) Thermal deformation analysis of (a) simply supported square plates, (b) simply supported-clamped square plate and (c) simply supported spherical shells. A numerical example is also presented demonstrating the application of the present formulation to analyse a symmetrically laminated graphite/epoxy laminate excited by a layer of piezoelectric polyvinylidene flouride (PVDF). The results presented are in good agreement with those available in the literature.

  5. Air/liquid collectors

    DEFF Research Database (Denmark)

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

    1997-01-01

    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...

  6. End plate for e.g. solid oxide fuel cell stack, sets thermal expansion coefficient of material to predetermined value

    DEFF Research Database (Denmark)

    2011-01-01

    .05-0.3 mm. USE - End plate for solid oxide fuel cell stack (claimed). Can also be used in polymer electrolyte fuel cell stack and direct methanol fuel cell stack. ADVANTAGE - The robustness of the end plate is improved. The structure of the end plate is simplified. The risk of delamination of the stack......NOVELTY - The end plate is made of material whose thermal expansion coefficient is corresponding to that of material of a cell (103). The thermal expansion coefficient of material is 9asterisk10-6 K-1 to 14asterisk10-6 K11. The thickness of the end plate is within the range of 0.001-1 mm and 0...

  7. Analysis of Thermal Buckling of Ceramic-Metal Functionally Graded Plates Using Refined Third Order Shear Deformation Theory

    Directory of Open Access Journals (Sweden)

    S. S. Daimi

    2014-08-01

    Full Text Available Functionally graded materials (FGMs are microscopically inhomogeneous spatial composite materials, typically composed of a ceramic-metal or ceramic-polymer pair of materials. Therefore, it is important to investigate the behaviors of engineering structures such as beams and plates made from FGMs when they are subjected to thermal loads for appropriate design. Therefore, using an improved third order shear deformation theory (TSDT based on more rigorous kinetics of displacements to predict the behaviors of functionally graded plates is expected to be more suitable than using other theories. In this paper, the improved TSDT is used to investigate thermal buckling of functionally graded plates. Temperature dependent material property solutions are adopted to investigate thermal buckling results of functionally graded plates. To obtain the solutions, the Ritz method using polynomial and trigonometric functions for defining admissible displacements and rotations is applied to solve the governing equations.

  8. 多孔体太阳空气集热供暖系统热性能实验研究%EXPERIMENTAL STUDY ON THERMAL PERFORMANCE OF HEATING SYSTEMS USING PERFORATED-ABSORBER SOLAR AIR COLLECTOR

    Institute of Scientific and Technical Information of China (English)

    高林朝; 沈胜强; 郝庆英; 李士瑄; 肖菊

    2012-01-01

    A heating system of the perforated-absorber solar air collector integrated with buildings was designed. Experimental study on effect of pore size of the perforated-absorber collector, air circulating mode and mass flow rate within collector on thermal performance and indoor thermal environment was carried out. The results showed that the air temperature difference of collector at the air inlet/outlet can reach to 24.0℃ ; Under forced convection, the middle and outlet air temperature of perforated-absorber collector with small pore size (diameter 1. 6mm, hole spacing 12mm) are 6. 0℃ and 4. 7℃ higher than those with large pore size (diameter 5. 0mm, hole spacing 25 mm) , the average heat collecting efficiency is only difference from 0.045 to 0. 060; The improvement of thermal performance is not obvious by increasing pore size; In addition, the average indoor temperature of the tested room with 1. 85m2 collector is about 7. O℃, higher than that of the reference room. In the sunny daytime, the heating system can basically meet the requirements for indoor temperature in winter.%设计一种多孔体型太阳空气集热器建筑供暖系统.实验研究不同孔径集热板形式和空气循环流动方式对建筑供暖系统热性能及其室内热环境的影响.实测结果表明,集热器进、出风口空气平均温差达24.0℃以上;强制循环方式下孔径1.6mm、孔间距12mm的集热板较孔径5.0mm、孔间距25 mm的集热板中心点和出风口温度高6.0℃和4.7C,集热效率仅相差0.045~0.060;增大孔径对提高集热效率作用不明显;单台1.85m2集热面积晴好天气可使实验房白天室内温度较对比房高约7.0℃,可满足冬季室内温度要求.

  9. 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

  10. THE RESEARCH OF TEST METHODS FOR THE THERMAL PERFORMANCE OF SOLAR AIR COLLECTORS%太阳能空气集热器热性能测试方法研究

    Institute of Scientific and Technical Information of China (English)

    孙峙峰; 曲世琳

    2011-01-01

    It is established the mathematical model and given test methods for the thermal performance of solar air collectors on the basis of both at home and abroad standards and documents. And the practical test was done at the National Center of Quality Supervision and Testing for Solar Heating System (Beijing) according the test methods and test results were analyzed. In this study, test methods for the thermal performance of solar air collectors which appropriate to the level of China' s solar air collector quality were given. It is a good technology and experimental reserves for constituting the national test standards for the thermal performance of solar air collectors.%在参考国内外标准和文献资料的基础上,建立太阳能空气集热器的测试数学模型,给出太阳能空气集热器热性能测试的试验方法,在国家太阳能热水器质量监督检验中心(北京)的实验室进行太阳能空气集热器实际测试,并对测试结果进行分析.给出适合我国太阳能空气集热器质量水平的太阳能空气集热器热性能测试方法,为制定我国太阳能空气集热器热性能测试国家标准做技术和实验储备.

  11. Analytical model of unsteady-state convective heat transfer between the heat carrier and the finite sizes plate adjusted for the thermal relaxation

    Directory of Open Access Journals (Sweden)

    Makarushkin Danila

    2017-01-01

    Full Text Available A hyperbolic boundary value problem of the thermal conduction of a two-dimensional plate with the third kind boundary conditions is formulated. The transient thermal process in the plate is due to the temperature changes of the external medium over time and along the plate length, and also by a multiple step change of the plate surface heat transfer coefficient throughout the transient process. An analytical solution with improved convergence adjusted for thermal relaxation and thermal damping is obtained for the temperature field in the plate.

  12. Buckling Behavior of Long Anisotropic Plates Subjected to Elastically Restrained Thermal Expansion and Contraction

    Science.gov (United States)

    Nemeth, Michael P.

    2004-01-01

    An approach for synthesizing buckling results for thin balanced and unbalanced symmetric laminates that are subjected to uniform heating or cooling and elastically restrained against thermal expansion or contraction is presented. This approach uses a nondimensional analysis for infinitely long, flexural anisotropic plates that are subjected to combined mechanical loads. In addition, stiffness-weighted laminate thermal-expansion parameters and compliance coefficients are derived that are used to determine critical temperatures in terms of physically intuitive mechanical-buckling coefficients. Many results are presented for some common laminates that are intended to facilitate a structural designer s transition to the use of the generic buckling design curves. Several curves that illustrate the fundamental parameters used in the analysis are presented, for nine contemporary material systems, that provide physical insight into the buckling response in addition to providing useful design data. Examples are presented that demonstrate the use of the generic design curves.

  13. Numerical analysis on thermal hydraulic performance of a flat plate heat pipe with wick column

    Science.gov (United States)

    Lu, Longsheng; Liao, Huosheng; Liu, Xiaokang; Tang, Yong

    2015-08-01

    A simplified thermal hydraulic model is developed to investigate the influence of wick column on the performance of a flat plate heat pipe (FPHP). The governing equations of the FPHP are solved by using the computational fluid dynamics package FLUENT. The temperature, velocity and pressure fields are obtained. The validity of the model is confirmed by comparing the present solutions with the open literature data. The numerical results show that with the increase of the wick column size, the maximum velocity of the liquid and vapor decreases while the total thermal resistance and capillary heat transfer limit of the FPHP increases gradually. The performance of the FPHP may degrade if the wick column is placed inside the vapor core asymmetrically.

  14. Analytical Thermal and Cost Optimization of Micro-Structured Plate-Fin Heat Sink

    DEFF Research Database (Denmark)

    Rezaniakolaei, Alireza; Rosendahl, Lasse

    Microchannel heat sinks have been widely used in the field of thermo-fluids due to the rapid growth in technological applications which require high rates of heat transfer in relatively small spaces and volumes. In this work, a micro plate-fin heat sink is optimized parametrically, to minimize...... the thermal resistance and to maximize the cost performance of the heat sink. The width and the height of the microchannels, and the fin thickness are analytically optimized at a wide range of pumping power. Using an effective numeric test, the generated equations also discuss the optimum parameters at three...... sizes of the substrate plat of the heat sink. Results show that, at any pumping power there are specific values of the channel width and fin thickness which produce minimum thermal resistance in the heat sink. The results also illustrate that, a larger channel width and a smaller fin thickness lead...

  15. A numerical model of a coated capillary-plate thermal neutron collimator

    Institute of Scientific and Technical Information of China (English)

    TIAN Yang; YANG Yi-Gang; LI Yu-Lan; LI Yuan-Jing

    2012-01-01

    A novel thermal neutron collimator was successfully fabricated by coating the inner surface of the capillary plate (CP) with gadolinium oxide using atomic layer deposition (ALD) technology.This CP-based collimator is efficient and compact.A numerical model is presented in the paper to estimate the main performance characteristics of the collimator and to optimize the design for specific applications.According to the results of the calculation based on currently available CPs,the FWHM of the collimator's rocking curve can be smaller than 0.15° while suppressing more than 99.9% of the incident thermal neutrons on the double wings of the curve.Such a coated CP is as thin as 1.25 mm or even thinner,providing high angular resolution with good transmission in a very limited space.

  16. Unsteady MHD free convective Couette flow between vertical porous plates with thermal radiation

    Directory of Open Access Journals (Sweden)

    Basant K. Jha

    2015-10-01

    Full Text Available This study investigates the unsteady MHD free convective Couette flow of viscous incompressible electrically conducting fluid between two infinite vertical porous plates in the presence of transverse magnetic field and thermal radiation. Solutions for time dependent energy and momentum equations are obtained by the implicit finite difference method. To check the accuracy of the numerical solutions, steady state solutions for energy and momentum equations are obtained by using the perturbation method. The effect of various parameters controlling the physical situation is discussed with the aid of line graphs. Significant results from this study are that both velocity and temperature increase with the increase in thermal radiation parameter and time. A series of numerical experiments show that steady state velocity and temperature occur when the dimensionless time approaches the values of Prandtl number of the fluid. During the course of numerical computation, an excellent agreement was found between unsteady and steady state solutions at large value of time.

  17. Central receiver solar thermal power system, Phase 1. CRDL Item 2. Pilot plant preliminary design report. Volume III, Book 2. Collector subsystem

    Energy Technology Data Exchange (ETDEWEB)

    Hallet, Jr., R. W.; Gervais, R. L.

    1977-10-01

    The methods and plans for the manufacture of the 10-MW collector heliostats and associated controls for the pilot plant are detailed. An in-depth description of the production, installation, and verification testing of heliostats for the pilot plant is presented. Specifications for the performance, design, and test requirements for the pilot plant collector subsystem are included. Also, a heliostat location summary report is given. (WHK)

  18. Air/liquid collectors

    DEFF Research Database (Denmark)

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

    1997-01-01

    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...... 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...

  19. Effects of High Temperature on Collector Coatings

    Science.gov (United States)

    Lowery, J. R.

    1982-01-01

    Report reveals electroplated black chrome is good coating for concentrating collectors in which temperatures are in the 650 degrees-800 degrees F (340 degrees - 430 degrees C) range. Black chrome thermal emittance is low and solar-absorption properties are not seriously degraded at high temperatures. Black coatings are used to increase absorption of solar energy by base metal while decreasing emission of infrared energy. Coatings are intended to improve efficiency of solar collectors.

  20. NONLINEAR BUCKLING BEHAVIOR OF DAMAGED COMPOSITE SANDWICH PLATES CONSIDERING THE EFFECT OF TEMPERATURE-DEPENDENT THERMAL AND MECHANICAL PROPERTIES

    Institute of Scientific and Technical Information of China (English)

    Bai Ruixiang; Chen Haoran

    2001-01-01

    On the basis of the first-order shear deformation plate theory and the zig-zag deformation assumption, an incremental finite element formulation for nonlinear buckling analysis of the composite sandwich plate is deduced and the temperature-dependent thermal and mechanical properties of composite is considered. A finite element method for thermal or thermo-mechanical coupling nonlinear buckling analysis of the composite sandwich plate with an interfacial crack damage between face and core is also developed. Numerical results and discussions concerning some typical examples show that the effects of the variation of the thermal and mechanical properties with temperature, extermal compressive loading, size of the damage zone and piy angle of the faces on the thermal buckling behavior are significant.