WorldWideScience

Sample records for charge collectors

  1. Simulation of HPIB propagation in biased charge collector

    International Nuclear Information System (INIS)

    A 2.5D PIC simulation using KARAT code for inner charge propagation within biased charge collector for measuring HPIB is presented. The simulation results indicate that the charges were neutralized but the current non-neutralized in the biased charge collector. The influence of ions collected vs biased voltage of the collector was also simulated. -800 V biased voltage can meet the measurement of 500 keV HPIB, and this is consistent with the experimental results

  2. Characterization of Cable Gun Plasma with a Charge Collector Array

    Institute of Scientific and Technical Information of China (English)

    陈玉兰; 曾正中; 孙凤举; 蒯斌; 邱爱慈; 尹佳辉; 丛培天; 梁天学

    2003-01-01

    The density, drift velocity and reproducibility of the plasma produced by a cableplasma gun array have been measured with a charge collector array. The plasma is used to prefilla coaxial plasma-opening switch with a conducting time approaching 0.4μs. The reproducibilityof the plasma source in subsequent shots is better than 5%. Near the gun nozzle and the oppositeelectrode, the plasma density amounts to 1015cm-3, which is 2 times to 3 times that in the gapbetween the two coaxial electrodes. A plasma drift velocity of about 2.4 cm/μs is observed fromthe time of flight of the charged particles. Both plasma density and drift velocity increase almostlinearly with the rise in charge voltage.

  3. Characterization of cable gun plasma with a charge collector array

    International Nuclear Information System (INIS)

    The density, drift velocity and reproducibility of the plasma produced by a cable plasma gun array have been measured with a charge collector array. The plasma is used to prefill a coaxial plasma-opening switch with a conducting time approaching 0.4 μs. The reproducibility of the plasma source in subsequent shots is better than 5%. Near the gun nozzle and the opposite electrode, the plasma density amounts to 1015 cm-3, which is 2 times to 3 times that in the gap between the two coaxial electrodes. A plasma drift velocity of about 2.4 cm/μs is observed from the time of flight of the charged particles. Both plasma density and drift velocity increase almost linearly with the rise in charge voltage

  4. Design, development, and results from a charge-collector diagnostic for a toroidal electron plasma experiment

    International Nuclear Information System (INIS)

    A suitable charge-collector has been designed and developed to estimate charge-content of electron plasmas in a Small Aspect Ratio Toroidal Experiment in a C-shaped trap (SMARTEX-C). The electrons are periodically injected and held in the trap with the aid of electrostatic end-fields and a toroidal magnetic field. After a preset “hold” time, the trapped charges are dumped onto a grounded collector (by gating it). As the charges flow along the magnetic field lines onto the collector, the integrated current gives the charge-content of the plasma at the instant of dump. In designing such a charge collector, several challenges peculiar to the geometry of the trap and the nature of the plasma had to be addressed. Instantaneous charge measurements synchronised with the E × B drift of the plasma, along with fast transit times of electrons to the collector (few 100 ns or less) (due to the low aspect ratio of the trap) essentially require fast gating of the collector. The resulting large capacitive transients alongside low charge content (few nC) of such plasmas further lead to increasing demands on response and sensitivity of the collector. Complete cancellation of such transients is shown to be possible, in principle, by including the return path in our measurement circuit but the “non-neutrality” of the plasma acts as a further impediment. Ultimately, appropriate shielding and measurement circuits allow us to (re)distribute the capacitance and delineate the paths of these currents, leading to effective cancellation of transients and marked improvement in sensitivity. Improved charge-collector has thus been used to successfully estimate the time evolution of total charge of the confined electron plasma in SMARTEX-C

  5. Design, development, and results from a charge-collector diagnostic for a toroidal electron plasma experiment

    Science.gov (United States)

    Pahari, Sambaran; Lachhvani, Lavkesh; Bajpai, Manu; Rathod, Karan; Yeole, Yogesh; Chattopadhyay, P. K.

    2015-08-01

    A suitable charge-collector has been designed and developed to estimate charge-content of electron plasmas in a Small Aspect Ratio Toroidal Experiment in a C-shaped trap (SMARTEX-C). The electrons are periodically injected and held in the trap with the aid of electrostatic end-fields and a toroidal magnetic field. After a preset "hold" time, the trapped charges are dumped onto a grounded collector (by gating it). As the charges flow along the magnetic field lines onto the collector, the integrated current gives the charge-content of the plasma at the instant of dump. In designing such a charge collector, several challenges peculiar to the geometry of the trap and the nature of the plasma had to be addressed. Instantaneous charge measurements synchronised with the E × B drift of the plasma, along with fast transit times of electrons to the collector (few 100 ns or less) (due to the low aspect ratio of the trap) essentially require fast gating of the collector. The resulting large capacitive transients alongside low charge content (few nC) of such plasmas further lead to increasing demands on response and sensitivity of the collector. Complete cancellation of such transients is shown to be possible, in principle, by including the return path in our measurement circuit but the "non-neutrality" of the plasma acts as a further impediment. Ultimately, appropriate shielding and measurement circuits allow us to (re)distribute the capacitance and delineate the paths of these currents, leading to effective cancellation of transients and marked improvement in sensitivity. Improved charge-collector has thus been used to successfully estimate the time evolution of total charge of the confined electron plasma in SMARTEX-C.

  6. A high performance charge plasma PN-Schottky collector transistor on silicon-on-insulator

    International Nuclear Information System (INIS)

    In this paper, we propose a new high performance PN-Schottky collector (PN-SC) lateral bipolar junction transistor (BJT) on silicon-on-insulator (SOI). The proposed device addresses the problem of poor speed of conventional lateral PNP-BJT device by using a Schottky collector. Further, it does not use the conventional ways of ion implantation/diffusion to realize n and p type doped region. However, it uses metal electrodes of different work functions to create n and p type charge plasma in an undoped silicon film. The simulation study of the proposed lateral PN-SC bipolar charge plasma transistor on SOI (PN-SC-BCPT) device has shown a significant improvement in current gain (β), cutoff frequency (f T) and switching performance in comparison to conventional PNP-BJT and PNP-bipolar charge plasma transistor (PNP-BCPT) devices. A significantly high β is obtained in the proposed PN-SC-BCPT (∼2100) in comparison to PNP-BCPT (∼1450) and the conventional BJT (∼9) devices, respectively. It has been observed that there is 89.56% and 153.5% increase in f T for the proposed PN-SC-BCPT device (2.18 GHz) in comparison to conventional PNP-BJT (1.15 GHz) and PNP-BCPT (0.86 GHz) devices, respectively. Further, reductions of 24.6% and 15.4% in switching ON-delay and 66% and 30.76% in switching OFF-delay have been achieved in the proposed device based inverters in comparison to PNP-BCPT and the conventional BJT devices based inverters, respectively. Furthermore, the proposed device does not face doping related issues and the requirement of high temperature processing is absent. (paper)

  7. Dose control in electron beam processing: Comparison of results from a graphite charge collector, routine dosimeters and the ISS alanine-based dosimeter

    Science.gov (United States)

    Fuochi, P. G.; Onori, S.; Casali, F.; Chirco, P.

    1993-10-01

    A 12 MeV linear accelerator is currently used for electron beam processing of power semiconductor devices for lifetime control and, on an experimental basis, for food irradiation, sludge treatment etc. In order to control the irradiation process a simple, quick and reliable method for a direct evaluation of dose and fluence in a broad electron beam has been developed. This paper presents the results obtained using a "charge collector" which measures the charge absorbed in a graphite target exposed in air. Calibration of the system with super-Fricke dosimeter and comparison of absorbed dose results obtained with plastic dosimeters and alanine pellets are discussed.

  8. The Orbiting Wide-Angle Light Collectors (OWL) Mission for Charged-Particle Astronomy

    Science.gov (United States)

    Mitchell, John; Krizmanic, J. F.; Stecker, F. W.; Streitmatter, R. E.

    2009-01-01

    The space-based OWL mission is designed to perform high-statistics measurements of ultra-high-energy cosmic rays (UHECR) using the Earth's atmosphere as a vast particle calorimeter, furthering the field of charged-particle astronomy. OWL has been developed in formal NASA instrument and mission studies and is comprised of two large telescopes separated by approx.600 km in 1000 km, near-equatorial orbits to stereoscopically image the near-UV air fluorescence emitted by UHECR-induced particle cascades. The High Resolution Fly's Eye (HiRes) Collaboration, and subsequently the Pierre Auger Observatory, recently reported confirmation of the expected Greisen-Zatsepin-Kuzmin (GZK) suppression of the UHECR flux above a few times 10(exp 19) eV. This observation is consistent with the majority of UHECR originating in astrophysical objects and reduces the need to invoke exotic physical processes. Particles observed above the GZK threshold energy must have come from sources within about 100 Mpc from the Earth. The small particle deflection angles expected at UHECR energies, with standard assumptions of extragalactic magnetic fields, are on the order of 1 degree. Thus by observing particles above the GZK threshold with sufficient exposure, there is the potential of identifying and characterizing individual UHECR sources. Auger has reported significant anisotropy in the arrival directions of UHECR at energies above about 6 10(exp 19) eV observed in the South, and a correlation to AGN in the 12th VCV catalog, suggesting that the sources of UHECR are traced by the distribution of luminous matter in the Universe. However, with similar statistics and the same event selection criteria, HiRes observations in the North are consistent with isotropy. Extended observations by Auger-South, by Telescope Array in the North, and possibly by the proposed Auger-North, will further these investigations. However, much greater exposures will be required to fully identify individual sources and

  9. Re-evaluation of interferences of doubly charged ions of heavy rare earth elements on Sr isotopic analysis using multi-collector inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    We re-evaluate the interference of doubly charged heavy rare earth elements during Sr isotopic analysis using multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). A series of mixed solutions of standard reference material SRM 987, rare earth elements, and Sr separated from rock reference materials are measured to assess the influence of isobaric interferences on the MC-ICP-MS analysis of Sr isotopes. After sample dissolution, conventional cation-exchange chromatography is employed for Sr purification of rock reference materials prior to MC-ICP-MS measurement. It has been demonstrated that if the natural abundances of Er and Yb are used to correct for doubly charged ion interferences on Sr, an overcorrection results. In contrast, the use of measured doubly charged ion ratios results in an accurate and precise correction of isobaric interference. This finding is confirmed by analytical results for several certified reference materials from mafic (basaltic) to felsic (granitic) silicate rocks. It is noteworthy that, because Er is more prone to doubly charged ion formation, it dominates over Yb doubly charged ions as an interference source. - Highlights: • We re-investigated interference of doubly charged HREE ion on Sr isotope. • Natural abundance of Er and Yb to correct the interference leads to an overcorrection. • Er is more prone to doubly charged ion formation than Yb

  10. On the use of a charged tunnel layer as a hole collector to improve the efficiency of amorphous silicon thin-film solar cells

    International Nuclear Information System (INIS)

    A new concept, using a negatively charged tunnel layer as a hole collector, is proposed and theoretically investigated for application in amorphous silicon thin-film solar cells. The concept features a glass/transparent conductive oxide/ultra-thin negatively charged tunnel layer/intrinsic a-Si:H/n-doped a-Si:H/metal structure. The key feature of this so called t+-i-n structure is the introduction of a negatively charged tunnel layer (attracting holes from the intrinsic absorber layer), which substitutes the highly recombination active p-doped a-Si:H layer in a conventional p-i-n configuration. Atomic layer deposited aluminum oxide (ALD AlOx) is suggested as a potential candidate for such a tunnel layer. Using typical ALD AlOx parameters, a 27% relative efficiency increase (i.e., from 9.7% to 12.3%) is predicted theoretically for a single-junction a-Si:H solar cell on a textured superstrate. This prediction is based on parameters that reproduce the experimentally obtained external quantum efficiency and current-voltage characteristics of a conventional processed p-i-n a-Si:H solar cell, reaching 9.7% efficiency and serving as a reference. Subsequently, the p-doped a-Si:H layer is replaced by the tunnel layer (studied by means of numerical device simulation). Using a t+-i-n configuration instead of a conventional p-i-n configuration will not only increase the short-circuit current density (from 14.4 to 14.9 mA/cm2, according to our simulations), it also enhances the open-circuit voltage and the fill factor (from 917 mV to 1.0 V and from 74% to 83%, respectively). For this concept to work efficiently, a high work function front electrode material or a high interface charge is needed

  11. Optimization of the Orbiting Wide-angle Light Collectors (OWL) Mission for Charged-Particle and Neutrino Astronomy

    CERN Document Server

    Krizmanic, John F; Streitmatter, Robert E

    2013-01-01

    OWL uses the Earth's atmosphere as a vast calorimeter to fully enable the emerging field of charged-particle astronomy with high-statistics measurements of ultra-high-energy cosmic rays (UHECR) and a search for sources of UHE neutrinos and photons. Confirmation of the Greisen-Zatsepin-Kuzmin (GZK) suppression above ~4 x 10^19 eV suggests that most UHECR originate in astrophysical objects. Higher energy particles must come from sources within about 100 Mpc and are deflected by ~1 degree by predicted intergalactic/galactic magnetic fields. The Pierre Auger Array, Telescope Array and the future JEM-EUSO ISS mission will open charged-particle astronomy, but much greater exposure will be required to fully identify and measure the spectra of individual sources. OWL uses two large telescopes with 3 m optical apertures and 45 degree FOV in near-equatorial orbits. Simulations of a five-year OWL mission indicate ~10^6 km^2 sr yr of exposure with full aperture at ~6 x 10^19 eV. Observations at different altitudes and sp...

  12. Optimization of the Orbiting Wide-Angle Light Collectors (OWL) Mission for Charged-Particle and Neutrino Astronomy

    Science.gov (United States)

    Krizmanic, John F.; Mitchell, John W.; Streitmatter, Robert E.

    2013-01-01

    OWL [1] uses the Earth's atmosphere as a vast calorimeter to fully enable the emerging field of charged-particle astronomy with high-statistics measurements of ultra-high-energy cosmic rays (UHECR) and a search for sources of UHE neutrinos and photons. Confirmation of the Greisen-Zatsepin-Kuzmin (GZK) suppression above approx. 4 x 10(exp 19) eV suggests that most UHECR originate in astrophysical objects. Higher energy particles must come from sources within about 100 Mpc and are deflected by approx. 1 degree by predicted intergalactic/galactic magnetic fields. The Pierre Auger Array, Telescope Array and the future JEM-EUSO ISS mission will open charged-particle astronomy, but much greater exposure will be required to fully identify and measure the spectra of individual sources. OWL uses two large telescopes with 3 m optical apertures and 45 degree FOV in near-equatorial orbits. Simulations of a five-year OWL mission indicate approx. 10(exp 6) sq km/ sr/ yr of exposure with full aperture at approx. 6 x 10(exp 19) eV. Observations at different altitudes and spacecraft separations optimize sensitivity to UHECRs and neutrinos. OWL's stereo event reconstruction is nearly independent of track inclination and very tolerant of atmospheric conditions. An optional monocular mode gives increased reliability and can increase the instantaneous aperture. OWL can fully reconstruct horizontal and upward-moving showers and so has high sensitivity to UHE neutrinos. New capabilities in inflatable structures optics and silicon photomultipliers can greatly increase photon sensitivity, reducing the energy threshold for n detection or increasing viewed area using a higher orbit. Design trades between the original and optimized OWL missions and the enhanced science capabilities are described.

  13. Magnetic collectors

    International Nuclear Information System (INIS)

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

  14. Solar energy collector system

    Energy Technology Data Exchange (ETDEWEB)

    Dumbeck, R.F.

    1982-04-13

    Simple flat plate reflectors, preferably compound of a panel with a reflector surface layer laminated thereto, are pivoted to move with the position of the sun and concentrate additional energy on a solar energy collector panel. The array can take a tented or triangular end view shape for closing to protect reflective surfaces from hail or sandstorm, etc. Also the surfaces are provided with a periodically operable surface cleaner to assure long term efficiency even when remotely positioned as on roof top. Low cost present day computers are programmed to track the sun over its seasonal variations by means of simple mechanisms pivoting the reflector plates. The system is self-energizing by means of batteries charged by solar panels accompanying the system. Solar energy is storable in a self-contained water tank for use at night, etc. And efficient energy conversion is attained by means of a stainless steel pipe length extending into the stored water and thermally coupled outside the tank to a solar heated higher than 100* C. Silicon oil circulated through the solar collector. Thus, vaporization is avoided and an effective lowcost simplified thermal energy conversion is effected.

  15. 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...

  16. Pulsed depressed collector

    Energy Technology Data Exchange (ETDEWEB)

    Kemp, Mark A

    2015-11-03

    A high power RF device has an electron beam cavity, a modulator, and a circuit for feed-forward energy recovery from a multi-stage depressed collector to the modulator. The electron beam cavity include a cathode, an anode, and the multi-stage depressed collector, and the modulator is configured to provide pulses to the cathode. Voltages of the electrode stages of the multi-stage depressed collector are allowed to float as determined by fixed impedances seen by the electrode stages. The energy recovery circuit includes a storage capacitor that dynamically biases potentials of the electrode stages of the multi-stage depressed collector and provides recovered energy from the electrode stages of the multi-stage depressed collector to the modulator. The circuit may also include a step-down transformer, where the electrode stages of the multi-stage depressed collector are electrically connected to separate taps on the step-down transformer.

  17. Discussion about Dust Collector for Coke Pushing Car of Top Charging Coke Oven%顶装焦炉推焦车烟尘捕集装置的探讨

    Institute of Scientific and Technical Information of China (English)

    樊海莲

    2015-01-01

    针对顶装焦炉推焦车烟尘捕集装置存在的问题 ,提出了相应的解决措施 ,以提高环保效果为目标 ,使太重公司的产品成为具有市场竞争力的高可靠性、实用性的设备.%In this article ,to the problems in dust collector for coke pushing car of top charging coke oven ,a relevant solution is giv-en ,which aims at high environmental protection ,to makes our products have high reliability and practicality in market competitive-ness .

  18. 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.

  19. Miniature, ruggedized data collector

    Science.gov (United States)

    Jackson, Scott; Calcutt, Wade; Knobler, Ron; Jones, Barry; Klug, Robert

    2009-05-01

    McQ has developed a miniaturized, programmable, ruggedized data collector intended for use in weapon testing or data collection exercises that impose severe stresses on devices under test. The recorder is designed to survive these stresses which include acceleration and shock levels up to 100,000 G. The collector acquires and stores up to four channels of signal data to nonvolatile memory for later retrieval by a user. It is small (< 7 in3), light weight (< 1 lb), and can operate from various battery chemistries. A built-in menuing system, accessible via a USB interface, allows the user to configure parameters of the recorder operation, such as channel gain, filtering, and signal offsets, and also to retrieve recorded data for analysis. An overview of the collector, its features, performance, and potential uses, is presented.

  20. Collector/collector guard ring balancing circuit eliminates edge effects

    Science.gov (United States)

    Lieb, D. P.

    1966-01-01

    Circuit in which an emitter is maintained opposite a concentric collector and guard structure is achieved by matching the temperature and potential of the guard with that of the collector over the operating range. This control system is capable of handling up to 100 amperes in the guard circuit and 200 amperes in the collectors circuit.

  1. Solar collector manufacturing activity, 1990

    International Nuclear Information System (INIS)

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

  2. Research on Flat Solar Collector

    OpenAIRE

    Kavolynas, Antanas

    2005-01-01

    The Thesis analyzes one of the spheres of alternative energy supply – the solar energy. The main objective of the Thesis is to determine the energy rates of the solar collector and its accumulative capacity. The Paper introduces a stand on the solar collector research which consists of a flat solar collector, heat accumulator and auxiliary equipment. The research object of the Thesis is a laboratory flat solar collector and its system. The Thesis analyses the constructions of the solar collec...

  3. Leaves: Nature's Solar Collectors

    Science.gov (United States)

    Isabelle, Aaron D.; de Groot, Cornelis

    2009-01-01

    One of the most captivating things about plants is the way they capture the Sun's energy, but this can be a difficult topic to cover with elementary students. Therefore, to help students to make a concrete connection to this abstract concept, this series of solar-energy lessons focuses on leaves and how they act as "solar collectors." As students…

  4. Flotation of aluminosilicate minerals using alkylguanidine collectors

    Institute of Scientific and Technical Information of China (English)

    GUAN Feng; ZHONG Hong; LIU Guang-yi; ZHAO Sheng-gui; XIA Liu-yin

    2009-01-01

    The flotation mechanism of aluminosilicate minerals using alkylguanidine collectors was studied through flotation experiments, Zeta potential measurements and FT-IR spectrum analysis. It is shown that kaolinite, illite and pyrophyllite all exhibit good floatability with alkylguanidines as collectors at pH 4-12. The flotation recoveries rise with the increase of the carbon chain length. Isoelectric point(IEP) is determined to be 3.5, 3.0 and 2.3 for kaolinite, illite and pyrophyllite, respectively. However, it is anomalous that the presence of cationic collectors has less influence on the negatively charged mineral surfaces. It is explained by the special structure of guanidine which is one of the strongest bases, having two -NH2 groups. One of them maybe interacts with minerals by electrostatic forces, and the other maybe forms hydrogen bonding with OH- ions on the aluminosilicate surfaces or in the aqueous solution, increasing the density of negative charge on the aluminosilicate surface and leading unpronounced positive charge to increase on the aluminosilicate. By combining the flotation tests, Zeta potential and FTIR measurements above, the interaction mechanism can be concluded. The simultaneous presence of cationic and neutral amine groups makes it possible for SAG cation to bind on three aluminosilicate minerals by both electrostatic attraction and hydrogen bonding. While in acidic medium, the interaction of the alkylguanidines on the aluminosilicate surfaces is mainly by means of electrostatic force and hydrogen bond; in the alkaline medium, it is by the way of electrostatic effect and hydrogen bond.

  5. Investigation of the isochronous mode of the experimental storage ring (ESR) and the collector ring (CR). Decay spectroscopy of highly charged stored {sup 140}Pr ions at the FRS-ESR facility

    Energy Technology Data Exchange (ETDEWEB)

    Litvinov, Sergey A.

    2008-11-15

    The combination of the present fragment separator FRS and the cooler-storage ring ESR at GSI provides conditions for accurate mass and unique half-life measurements of exotic nuclei. A major part of this doctoral work has been devoted to investigations of the isochronous ion-optical operating mode of the present ESR facility and the planned Collector Ring (CR) facility at FAIR. A detailed ion-optical study of the isochronous storage ring with the emphasis on the main parameters has been done. For example, a simple scaling law providing a quantitative estimate for the mass resolving power as a function of the transverse acceptance has been derived. The ion-optical matching of the FRS-ESR has been calculated and experimentally verified for both the standard and the isochronous operating modes of the ESR. In addition, the dispersion function of a stored ion beam has been measured for both ion-optical modes at the straight section. The improved setting for higher transmission in the standard mode has been used in an experiment on the half-life measurements of highly-charged ions. Orbital electron capture (EC) and/or {beta}{sup +}-decay rates of {sup 140}Pr ions with zero-, one- and two- bound electrons have been measured. A complementary future study of EC-decay in highly-charged {sup 64}Cu ions is discussed. Based on the present experience, the ion-optical matching between the future in-flight fragment separator Super-FRS and the CR has been calculated. The isochronous mode of the CR has been calculated. A dedicated Monte-Carlo code (ISOCHRON) has been developed in order to investigate the influence of the transverse acceptance, the closed orbit distortions, the fringe fields of the quadrupoles, the magnetic field imperfections of the magnets on the mass resolving power. The influence of chromaticity on the isochronicity has been investigated. The correction of the chromaticity and of second-order isochronicity has been performed employing sextupole magnets in the

  6. Investigation of the isochronous mode of the experimental storage ring (ESR) and the collector ring (CR). Decay spectroscopy of highly charged stored 140Pr ions at the FRS-ESR facility

    International Nuclear Information System (INIS)

    The combination of the present fragment separator FRS and the cooler-storage ring ESR at GSI provides conditions for accurate mass and unique half-life measurements of exotic nuclei. A major part of this doctoral work has been devoted to investigations of the isochronous ion-optical operating mode of the present ESR facility and the planned Collector Ring (CR) facility at FAIR. A detailed ion-optical study of the isochronous storage ring with the emphasis on the main parameters has been done. For example, a simple scaling law providing a quantitative estimate for the mass resolving power as a function of the transverse acceptance has been derived. The ion-optical matching of the FRS-ESR has been calculated and experimentally verified for both the standard and the isochronous operating modes of the ESR. In addition, the dispersion function of a stored ion beam has been measured for both ion-optical modes at the straight section. The improved setting for higher transmission in the standard mode has been used in an experiment on the half-life measurements of highly-charged ions. Orbital electron capture (EC) and/or β+-decay rates of 140Pr ions with zero-, one- and two- bound electrons have been measured. A complementary future study of EC-decay in highly-charged 64Cu ions is discussed. Based on the present experience, the ion-optical matching between the future in-flight fragment separator Super-FRS and the CR has been calculated. The isochronous mode of the CR has been calculated. A dedicated Monte-Carlo code (ISOCHRON) has been developed in order to investigate the influence of the transverse acceptance, the closed orbit distortions, the fringe fields of the quadrupoles, the magnetic field imperfections of the magnets on the mass resolving power. The influence of chromaticity on the isochronicity has been investigated. The correction of the chromaticity and of second-order isochronicity has been performed employing sextupole magnets in the arcs of the CR. The

  7. Parabolic concentrating collector: a tutorial

    Energy Technology Data Exchange (ETDEWEB)

    Truscello, V.C.

    1979-02-15

    A tutorial overview of point-focusing parabolic collectors is presented. Optical and thermal characteristics of such collectors are discussed. Data representing typical achievable collector efficiencies are presented and the importance of balancing collector cost with concentrator quality is argued through the development of a figure of merit for the collector. The impact of receiver temperature on performance is assessed and the general observation made that temperatures much in excess of 1500 to 2000/sup 0/F can actually result in decreased performance. Various types of two-axis tracking collectors are described, including the standard parabolic deep dish, Cassegrainian and Fresnel, as well as two forms of fixed mirrors with articulating receivers. The present DOE program to develop these devices is briefly discussed, as are present and projected costs for these collectors. Pricing information is presented for the only known commercial design available on the open market.

  8. Solar collector array

    Science.gov (United States)

    Hall, John Champlin; Martins, Guy Lawrence

    2015-09-06

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

  9. Solar energy collector

    Energy Technology Data Exchange (ETDEWEB)

    Knowles, G.W.; Sangesland, O.E.; Vroom, H.J.; Madey, R.W.

    1977-11-22

    A solar energy collector is described for collecting, concentrating, and utilizing solar energy. It includes a target for transferring solar energy into another useable energy form and a reflector positioned to increase the amount of solar energy reaching the target and prevent solar energy from escaping around the target. The target includes a transparent envelope and a heat pipe containing a heat transfer fluid. The heat pipe has an evaporator portion disposed within the transparent envelope and an emergent condenser portion with a flange forming a dry thermal interface with a manifold for conducting heat energy directly from the heat pipe to the manifold.

  10. Solar energy collector

    Energy Technology Data Exchange (ETDEWEB)

    Knowles, G.W.; Sangesland, O.E.; Vroom, H.J.; Madey, R.W.

    1978-10-10

    A solar energy collector for collecting, concentrating, and utilizing solar energy is described including a target for transferring solar energy into another useable energy form and reflector positioned to increase the amount of solar energy reaching the target and prevent solar energy from escaping around the target, the target including in its preferred form a transparent envelope and a heat pipe containing a heat transfer fluid, the heat pipe having an evaporator portion disposed within the transparent envelope and an emergent condenser portion with a flange forming a dry thermal interface with a manifold for conducting heat energy directly from the heat pipe to the manifold.

  11. The CERN antiproton collector

    International Nuclear Information System (INIS)

    The Antiproton Collector is a new ring of much larger acceptance than the present accumulator. It is designed to receive 108 antiprotons per PS cycle. In order to be compatible with the Antiproton Accumulator, the momentum spread and the emittances are reduced from 6% to 0.2% and from 200 π mm mrad to 25 π mm mrad respectively. In addition to the ring itself, the new target area and the modifications to the stochastic systems of the Antiproton Accumulator are described. (orig.)

  12. Combined solar collector

    OpenAIRE

    Voznyak, O.; Shapoval, S.; Pona, O.; Vengryn, I.

    2014-01-01

    In this article was analyzing the efficiency of the combined solar collector for heating buildings. This enhances the efficiency of solar system by increasing the area of the absorption of solar energy. There are describes the results of the research on solar radiation input on a combined solar collector. Проаналізовано ефективність використання комбінованого сонячного колектора для теплопостачання будівель. Він забезпечує підвищення ефективності геліосистеми за рахунок збільшення площі погли...

  13. Tower-supported solar-energy collector

    Science.gov (United States)

    Selcuk, M. K.

    1977-01-01

    Multiple-collector tower system supports three receiver/concentrators that absorb solar energy reflected from surrounding field of heliostats. System overcomes disadvantages of tower-supported collectors. Booms can be lowered during heavy winds to protect arms and collectors.

  14. Inverse Marx modulators for self-biasing klystron depressed collectors

    Energy Technology Data Exchange (ETDEWEB)

    Kemp, Mark A; /SLAC

    2014-07-31

    A novel pulsed depressed collector biasing scheme is proposed. This topology feeds forward energy recovered during one RF pulse for use on the following RF pulse. The presented ''inverse'' Marx charges biasing capacitors in series, and discharges them in parallel. Simulations are shown along with experimental demonstration on a 62kW klystron.

  15. Studies of collectors, 9

    International Nuclear Information System (INIS)

    Chelating surfactants bearing hydroxyaminocarbonyl and amino groups (RnAHx) and cotelomer-type surfactants bearing hydroxyaminocarbonyl and pyridyl groups (Ls-VP-Q-Hx) were prepared and applied as flotation collectors for a trace amount of uranium. The uranium in an aqueous solution of pH 4 - 8 and in seawater was floated more effectively by ion flotation using RnAHx or by foam fractionation using Ls-VP-Q-Hx, compared with alkylhydroxamic acid (RnHx) and telomers bearing hydroxyaminocarbonyl groups (Lo-Hx). The effective flotation was concluded to be due to the chelate effects between the two groups on the complex formation and to the HLB of the resulting complex. Furthermore, the uranium recoveries were examined by using a hydroxamic acid polymer (62Hx), a N-methylhydroxamic acid telomer (Ls5.6MHx), and its cotelomer (Ls3.2VP4.5MHx). (author)

  16. LHCb Tag Collector

    CERN Document Server

    Fuente Fernàndez, P; Cousin, N

    2011-01-01

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

  17. Biobriefcase aerosol collector

    Science.gov (United States)

    Bell, Perry M.; Christian, Allen T.; Bailey, Christopher G.; Willis, Ladona; Masquelier, Donald A.; Nasarabadi, Shanavaz L.

    2009-09-22

    A system for sampling air and collecting particles entrained in the air that potentially include bioagents. The system comprises providing a receiving surface, directing a liquid to the receiving surface and producing a liquid surface. Collecting samples of the air and directing the samples of air so that the samples of air with particles entrained in the air impact the liquid surface. The particles potentially including bioagents become captured in the liquid. The air with particles entrained in the air impacts the liquid surface with sufficient velocity to entrain the particles into the liquid but cause minor turbulence. The liquid surface has a surface tension and the collector samples the air and directs the air to the liquid surface so that the air with particles entrained in the air impacts the liquid surface with sufficient velocity to entrain the particles into the liquid, but cause minor turbulence on the surface resulting in insignificant evaporation of the liquid.

  18. AEROSOL PARTICLE COLLECTOR DESIGN STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S; Richard Dimenna, R

    2007-09-27

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

  19. Shenandoah parabolic dish solar collector

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, G.S.

    1985-01-01

    The objectives of the Shenandoah, Georgia, Solar Total Energy System are to design, construct, test, and operate a solar energy system to obtain experience with large-scale hardware systems for future applications. This report describes the initial design and testing activities conducted to select and develop a collector that would serve the need of such a solar total energy system. The parabolic dish was selected as the collector most likely to maximize energy collection as required by this specific site. The fabrication, testing, and installation of the parabolic dish collector incorporating improvements identified during the development testing phase are described.

  20. Design package for concentrating solar collector panels

    Energy Technology Data Exchange (ETDEWEB)

    1978-08-01

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

  1. ADVANCED HYBRID PARTICULATE COLLECTOR

    Energy Technology Data Exchange (ETDEWEB)

    Stanley J. Miller; Grant L. Schelkoph; Grant E. Dunham

    2000-12-01

    A new concept in particulate control, called an advanced hybrid particulate collector (AHPC), is being developed under funding from the US Department of Energy. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in an entirely novel manner. The AHPC concept combines fabric filtration and electrostatic precipitation in the same housing, providing major synergism between the two methods, both in the particulate collection step and in transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and solves the problem of reentrainment and recollection of dust in conventional baghouses. Phase I of the development effort consisted of design, construction, and testing of a 5.7-m{sup 3}/min (200-acfm) working AHPC model. Results from both 8-hour parametric tests and 100-hour proof-of-concept tests with two different coals demonstrated excellent operability and greater than 99.99% fine-particle collection efficiency.

  2. SOLAR NANTENNA ELECTROMAGNETIC COLLECTORS

    Energy Technology Data Exchange (ETDEWEB)

    Steven D. Novack; Dale K. Kotter; Dennis Slafer; Patrick Pinhero

    2008-08-01

    This research explores a new efficient approach for producing electricity from the abundant energy of the sun. A nanoantenna electromagnetic collector (NEC) has been designed, prototyped, and tested. Proof of concept has been validated. The device targets mid-infrared wavelengths where conventional photovoltaic (PV) solar cells do not respond but is abundant in solar energy. The initial concept of designing NEC antennas was based on scaling of radio frequency antenna theory. This approach has proven unsuccessful by many due to not fully understanding and accounting for the optical behavior of materials in the THz region. Also until recent years the nanofabrication methods were not available to fabricate the optical antenna elements. We have addressed and overcome both technology barriers. Several factors were critical in successful implementation of NEC including: 1) frequency-dependent modeling of antenna elements, 2) selection of materials with proper THz properties and 3) novel manufacturing methods that enable economical large-scale manufacturing. The work represents an important step toward the ultimate realization of a low-cost device that will collect as well as convert this radiation into electricity, which will lead to a wide spectrum, high conversion efficiency, and low cost solution to complement conventional PVs.

  3. Elastocapillary mist collector

    Science.gov (United States)

    Duprat, Camille; Labbé, Romain; Rewakowicz, Ana

    2015-11-01

    Fibrous media are commonly used to collect droplets from an aerosol. In particular, woven textiles are used to harvest fresh water from fog, and coalescing filters made of non-woven entangled fibers are used to extract oil drops from gas streams. We propose a novel mist collector made of a forest of vertical flexible threads. As the droplets accumulate on the fibers, capillary bridges are formed, leading to the collapse of adjacent fibers thus forming liquid columns. This improve the liquid collection by preventing clogging, enabling high capture and precluding re-entrainment of drops in the gas stream due to the immediate coalescence of incoming droplets, and promoting fast drainage. We find that the collection flow rate is constant and can be adjusted by varying the fibers arrangement and flexibility. We show that there is an optimal situation for which this collection rate, i.e. the global efficiency, is maximal due to an elastocapillary coupling that we further characterize with a model experiment. Specifically, we study the drainage between two flexible fibers. Depending on the geometry and the fiber deformations, several flow regimes are observed. We characterize these regimes, and discuss the consequences on the drainage velocity, and thus the collection efficiency.

  4. Design package for concentrating solar collector panels

    Science.gov (United States)

    1978-01-01

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

  5. Biobriefcase electrostatic aerosol collector

    Science.gov (United States)

    Bell, Perry M.; Christian, Allen T.; Bailey, Christopher G.; Willis, Ladona; Masquelier, Donald A.; Nasarabadi, Shanavaz L.

    2009-03-17

    A system for sampling air and collecting particles entrained in the air comprising a receiving surface, a liquid input that directs liquid to the receiving surface and produces a liquid surface, an air input that directs the air so that the air with particles entrained in the air impact the liquid surface, and an electrostatic contact connected to the liquid that imparts an electric charge to the liquid. The particles potentially including bioagents become captured in the liquid by the air with particles entrained in the air impacting the liquid surface. Collection efficiency is improved by the electrostatic contact electrically charging the liquid. The effects of impaction and adhesion due to electrically charging the liquid allows a unique combination in a particle capture medium that has a low fluid consumption rate while maintaining high efficiency.

  6. Collector for thermionic energy converter

    International Nuclear Information System (INIS)

    An improved collector is provided for a thermionic energy converter. The collector comprises a p-type layer of a semiconductor material formed on an n-type layer of a semiconductor material. The p-n junction is maintained in a forward biased condition. The electron affinity of the exposed surface of the p-type layer is effectively lowered to a low level near zero by the presence of a work function lowering activator. The dissipation of energy during collection is reduced by the passage of electrons through the p-type layer in the metastable conduction band state. A significant portion of the electron current remains at the potential of the fermi level of the n-type layer rather than dropping to the fermi level of the p-type layer. Less energy is therefore dissipated as heat and a higher net power output is delivered from a thermionic energy converter incorporating the collector

  7. ADVANCED HYBRID PARTICULATE COLLECTOR

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-12-01

    A new concept in particulate control, called an advanced hybrid particulate collector (AHPC), is being developed under funding from the U.S. Department of Energy. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in an entirely novel manner. The AHPC concept combines fabric filtration and electrostatic precipitation in the same housing, providing major synergism between the two methods, both in the particulate collection step and in transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and solves the problem of reentrainment and re-collection of dust in conventional baghouses. Phase I of the development effort consisted of design, construction, and testing of a 5.7-m{sup 3}/min (200-acfm) working AHPC model. Results from both 8-hr parametric tests and 100-hr proof-of-concept tests with two different coals demonstrated excellent operability and greater than 99.99% fine-particle collection efficiency. Since all of the developmental goals of Phase I were met, the approach was scaled up in Phase II to a size of 255 m{sup 3}/min (9000 acfm) (equivalent in size to 2.5 MW) and was installed on a slipstream at the Big Stone Power Plant. For Phase II, the AHPC at Big Stone Power Plant was operated continuously from late July 1999 until mid-December 1999. The Phase II results were highly successful in that ultrahigh particle collection efficiency was achieved, pressure drop was well controlled, and system operability was excellent. For Phase III, the AHPC was modified into a more compact configuration, and components were installed that were closer to what would be used in a full-scale commercial design. The modified AHPC was operated from April to July 2000. While operational results were acceptable during this time, inspection of bags in the summer of 2000 revealed some membrane damage to the fabric that appeared to be

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

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Gan-Jin; Oh, Yong-Hwan; Ryu, Cheol-Hwi [Hoseo University, Asan (Korea, Republic of); Choi, Ho-Sang [Kyungil University, Gyeongsan, (Korea, Republic of)

    2014-04-15

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

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

    International Nuclear Information System (INIS)

    Two commercial carbon plates were evaluated as a current collector (bipolar plate) in the all vanadium redox-flow battery (V-RFB). The performance properties of V-RFB were test in the current density of 60 mA/cm2. The electromotive forces (OCV at SOC 100%) of V-RFB using A and B current collector were 1.47 V and 1.54 V. The cell resistance of V-RFB using A current collector was 4.44-5.00 Ω·cm2 and 3.28-3.75 Ω·cm2 for charge and discharge, respectively. The cell resistance of V-RFB using B current collector was 4.19-4.42Ω·cm2 and 4.71-5.49Ω·cm2 for charge and discharge, respectively. The performance of V-RFB using each current collector was evaluated. The performance of V-RFB using A current collector was 93.1%, 76.8% and 71.4% for average current efficiency, average voltage efficiency and average energy efficiency, respectively. The performance of V-RFB using B current collector was 96.4%, 73.6% and 71.0% for average current efficiency, average voltage efficiency and average energy efficiency, respectively

  10. Performance verification of an air solar collector

    Science.gov (United States)

    Miller, D. C.; Romaker, R. F.

    1979-01-01

    Procedures and results of battery of qualification tests performed by independent certification agency on commercial solar collector are presented in report. Reported results were used as basis in judging collector suitable for field installation in residential and commerical buildings.

  11. Heat yield and characteristics of solar collectors

    International Nuclear Information System (INIS)

    The test results of the summer 1980 test on solar collectors are summarised. Apart from the 16 collectors tested under contract, two were investigated as a reference serving flat collectors, e.g. for the area of International Energy Agency (IEA), two were evacuated cylindrical collectors. The report allows the comparison of heat power outputs of the different products on the basis of the measured optical and thermal data values. (A.N.K.)

  12. Bondings for tubular solar collectors

    International Nuclear Information System (INIS)

    We studied the following four models of constructing solar collectors: tubes bonded above the absorber plate, tubes bonded under the absorber plate tubes in-line with the absorber plate and bondless tubes in-line with the absorber plate. 2 refs, 6 figs

  13. 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....

  14. Optical design for EUV lithography source collector

    Institute of Scientific and Technical Information of China (English)

    Shuqing Zhang; Qi Wang; Dongyuan Zhu; Runshun Li; Chang Liu

    2011-01-01

    @@ Wolter I collector is the best collector for extreme ultraviolet (EUV) lithography, which has a series of nested mirrors.It has high collection efficiency and can obtain more uniform intensity distribution at the intermediate focus (IF).A new design with the calculation sequence from the outer mirror to the inner one on the premise of satisfying the requirements of the collector is introduced.Based on this concept, a computer program is established and the optical parameters of the collector using the program is calculated.The design results indicate that the collector satisfies all the requirements.%Wolter I collector is the best collector for extreme ultraviolet (EUV) lithography, which has a series of nested mirrors. It has high collection efficiency and can obtain more uniform intensity distribution at the intermediate focus (IF). A new design with the calculation sequence from the outer mirror to the inner one on the premise of satisfying the requirements of the collector is introduced. Based on this concept, acomputer program is established and the optical parameters of the collector using the program is calculated.The design results indicate that the collector satisfies all the requirements.

  15. Heat yield and characteristics of solar collectors

    International Nuclear Information System (INIS)

    The results of the EIR collector test series of the summers 1978 and 1979 are presented. In total, there are 37 different collectors available on the Swiss market. The results are compared with those from the IEA (International Energy Agency) of presuggested reference collectors. Test methods are described and also the construction of the test bench. Also, briefly described is a development method for the calculation of gross heat yield from solar collectors. Then the characteristics of the reference collectors in connection with the test periods are considered, and their role in the calculation of results of single collector test series explained. A description of the spectral photometer is given. (A.N.K.)

  16. Tubular solid oxide fuel cell current collector

    Science.gov (United States)

    Bischoff, Brian L.; Sutton, Theodore G.; Armstrong, Timothy R.

    2010-07-20

    An internal current collector for use inside a tubular solid oxide fuel cell (TSOFC) electrode comprises a tubular coil spring disposed concentrically within a TSOFC electrode and in firm uniform tangential electrical contact with the electrode inner surface. The current collector maximizes the contact area between the current collector and the electrode. The current collector is made of a metal that is electrically conductive and able to survive under the operational conditions of the fuel cell, i.e., the cathode in air, and the anode in fuel such as hydrogen, CO, CO.sub.2, H.sub.2O or H.sub.2S.

  17. Solar evacuated tube collector: absorption chiller systems simulation

    Energy Technology Data Exchange (ETDEWEB)

    Leflar, J.A.; Duff, W.S.

    1977-12-01

    A residential air conditioning system incorporating an Arkla Solaire absorption chiller and Corning Glass Works evacuated tube collectors is simulated and the design parameters studied. Mathematical models of the evacuated tube collector and Arkla absorption chiller based on experimental results of the components have been created and incorporated into a complete system simulation. The chiller model includes transient start-up effects and the evacuated tube collector model includes numerous optical effects. A standard Arkla chiller in a humid climate (Washington, D.C.) and an Arkla unit with a modified charge for dry climates (Fort Collins, Colorado) are studied. Design parameters considered include the use of chilled water storage to reduce transient start-up effects of the absorption unit, the effects of removing heat from the solar system for preheating service hot water, the use of a tempering valve to prevent over-firing of the absorption unit in dry climates, and solar storage sizing considerations. The study results and conclusions are used to specify a cooling system design.

  18. Foldable Frame Supporting Electromagnetic Radiation Collectors

    DEFF Research Database (Denmark)

    2011-01-01

    The present invention relates to flexible frames supporting electromagnetic radiation collectors, such as antennas, antenna reflectors, deflectors or solar collectors, for celestial or terrestrial applications, which can be folded to be stored and/or transported. The method for stowing deforms the...

  19. OUT Success Stories: Transpired Solar Collectors

    International Nuclear Information System (INIS)

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

  20. Evaluation of Test Method for Solar Collector Efficiency

    OpenAIRE

    Fan, Jianhua; Shah, Louise Jivan; Furbo, Simon

    2006-01-01

    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 approx...

  1. X-ray micro tomography of three-dimensional embroidered current collectors for lithium-ion batteries

    Science.gov (United States)

    Aguiló-Aguayo, Noemí; Amann, Peter; Espiñeira, Pablo Pena; Petrasch, Jörg; Bechtold, Thomas

    2016-02-01

    X-ray micro computed tomography (μCT) is used for the morphological characterization of three-dimensional (3D) embroidered current collectors for LiFePO4 batteries. A conventional 2D planar configuration (aluminium foil as current collector) and two types of 3D embroidered configurations were compared. The μCT images were used to identify the different components in each configuration as well as to evaluate the corresponding volume fractions, porosities, mass fractions and apparent densities. Microtomographic scans complement analysis of typical galvanostatic charge/discharge cycles and confirm the suitability of 3D embroidered current collectors for their use in lithium-ion batteries.

  2. Low contact resistance carbon thin film modified current collectors for lithium Ion batteries

    International Nuclear Information System (INIS)

    Carbon films have been synthesized by chemical vapor deposition (CVD) on AISI 304 stainless steel (304SS) sheets with various C2H2/H2 flow ratios at 810 °C. The films exhibit three different morphologies and structures: filament, sphere and transition types at different C2H2/H2 flow ratios, as characterized by scanning electron microscopy, X-ray diffraction and Raman spectroscopy. It was found that the degree of graphitization increased with decreasing C2H2/H2 flow ratios. The carbon film modified 304SS sheets were used as cathode current collectors and coated with an active layer containing LiMn2O4 active materials, conducting additives and binders for lithium ion batteries. The electrochemical properties of these LiMn2O4 cells with bare and carbon film modified current collectors were investigated. Under high current operation, such as 3000 mA/g, the capacity of the LiMn2O4 cell with transition type carbon film modified current collector is 55% higher than the cell with bare current collector. The enhanced performances of high current density charge–discharge cycles can be attributed to the reduced contact resistance and improved charge transfer efficiency provided by the transition type carbon film modified current collectors. - Highlights: • Carbon films were synthesized by CVD on 304SS sheets. • The carbon film modified 304SS sheets were used as cathode current collectors. • The carbon film modified current collectors improved charge transfer efficiency

  3. 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.

  4. Solar energy collector and storage device

    Energy Technology Data Exchange (ETDEWEB)

    Smith, H.T.

    1979-08-28

    An improved flat plate solar energy collector of integral construction capable of mass production in which metal tubing is eliminated is described. The collector includes a stamped planar tray and a radiant energy absorber plate connected together to form the inlet and outlet fluid header and the innerconnecting channels therebetween. The planar tray and absorber plate are mounted in a molded insulated housing which integrally includes a storage tank. A fluid medium such as water is heated by solar radiation and circulated through the collector to the storage tank by thermal syphon. Elimination of conventional tubing greatly reduces fabrication costs and increases absorption efficiency.

  5. New tool for standardized collector performance calculations

    DEFF Research Database (Denmark)

    Perers, Bengt; Kovacs, Peter; Olsson, Marcus;

    2011-01-01

    A new tool for standardized calculation of solar collector performance has been developed in cooperation between SP Technical Research Institute Sweden, DTU Denmark and SERC Dalarna University. The tool is designed to calculate the annual performance for a number of representative cities in Europe...... on the basis of parameters from collector tests performed according to EN12975, without any intermediate conversions. The main target group for this tool is test institutes and certification bodies that intend to use it for conversion of collector model parameters derived from performance tests, into a more...

  6. Next Generation Solar Collectors for CSP

    Energy Technology Data Exchange (ETDEWEB)

    Molnar, Attila [3M Company, St. Paul, MN (United States); Charles, Ruth [3M Company, St. Paul, MN (United States)

    2014-07-31

    The intent of “Next Generation Solar Collectors for CSP” program was to develop key technology elements for collectors in Phase 1 (Budget Period 1), design these elements in Phase 2 (Budget Period 2) and to deploy and test the final collector in Phase 3 (Budget Period 3). 3M and DOE mutually agreed to terminate the program at the end of Budget Period 1, primarily due to timeline issues. However, significant advancements were achieved in developing a next generation reflective material and panel that has the potential to significantly improve the efficiency of CSP systems.

  7. A new collector for wolframite slime flotation

    Institute of Scientific and Technical Information of China (English)

    田学达; 杨运泉; 张小云; 王淀佐; 李隆峰; 朱建光

    2002-01-01

    With aniline and salicylaldehyde as main materials,a new collector for wolframite slime was synthesized.In a pulp of natural pH value,this collector can collect wolframite effectively.Its selectivity is similar to that of benzyl arsenic acid and better than that of sodium oleate.With this collector,a wolframite rough concentrate with grade 30.12% WO3 and recovery 91.50%,and a concentrate with grade 58.66% WO3 and recovery 85.00% were obtained respectively from a wolframite ore containing 4.08% WO3.

  8. Baghouse and cartridge dust collectors: A comparison

    Energy Technology Data Exchange (ETDEWEB)

    Grafe, T.; Kelley, G. (Torit and Day, Minneapolis, MN (United States))

    1993-09-01

    Increased demands are being placed on air filtration systems. The particular application will determine whether a baghouse or cartridge type is best. Baghouse and cartridge dust collectors both have their place in modern air filtering systems. Baghouses have been in use much longer, but cartridge types offer significant advantages for particular applications. The task facing the site engineer is to match the requirements of the specific application with the inherent characteristics of the dust collector. This article presents basic information about both types of dust collectors that can help provide the best solution to that problem.

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

    DEFF Research Database (Denmark)

    Chen, Ziqian; Furbo, Simon; Perers, Bengt; Fan, Jianhua; Andersen, Elsa

    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...

  10. Tilt assembly for tracking solar collector assembly

    Science.gov (United States)

    Almy, Charles; Peurach, John; Sandler, Reuben

    2012-01-24

    A tilt assembly is used with a solar collector assembly of the type comprising a frame, supporting a solar collector, for movement about a tilt axis by pivoting a drive element between first and second orientations. The tilt assembly comprises a drive element coupler connected to the drive element and a driver, the driver comprising a drive frame, a drive arm and a drive arm driver. The drive arm is mounted to the drive frame for pivotal movement about a drive arm axis. Movement on the drive arm mimics movement of the drive element. Drive element couplers can extend in opposite directions from the outer portion of the drive arm, whereby the assembly can be used between adjacent solar collector assemblies in a row of solar collector assemblies.

  11. Intermittent tracking of flat plate collectors

    International Nuclear Information System (INIS)

    A theoretical analysis of different intervals of intermittent two-axis tracking of the sun, on the amount of annual energy received by flat-plate collectors, has been carried out. The analysis was done for Ipoh, a city near the university at a latitude of 40 34 North in Malaysia. For the analysis, a computer program was developed to calculate the solar insulation according to the interval settings, considering ASHRAE Standard Sky assumption. Both direct and diffused components of solar radiation have been considered. The tracking system was targeted for flat plate collectors where the degree of tracking accuracy would be much lower Hence, the tracking mechanism will be much simpler and lower in costs. Results showed that by a 3-hour intermittent tracking, a flat-plate collector could get as much as 35% more annual energy than a fixed one. The 3-hour interval tracking greatly simplifies the gear mechanism from the motor to the solar collector. (Author)

  12. CISBAT 2007 - Solar collectors (heat and electricity)

    International Nuclear Information System (INIS)

    This is the third part of the proceedings of the 2007 CISBAT conference on Renewables in a changing climate, held in Lausanne, Switzerland. On the subject of Building and urban integration of renewables the following oral contributions are summarised: 'Facade integration of solar thermal collectors: present and future', 'Long term experiences with a versatile PV in roof system', 'Development of a design and performance prediction tool for the ground source heat pump and underground thermal storage system', 'Hygrothermal performance of earth-to-air heat exchanger: long-term data evaluation and short-term simulation' as well as 'The real cost of heating your home: a comparative assessment of home energy systems with external costs'. Poster-sessions on the subject include 'Central solar heating plants with seasonal heat storage', 'Analysis of forced convection for evaporative air flow and heat transfer in PV cooling channels', 'Renewable energy technology in Mali: constraints and options for a sustainable development', 'Effect of duct width in ducted photovoltaic facades', 'Design and actual measurement of a ground source heat pump system using steel foundation piles as ground heat exchangers', 'Development of an integrated water-water heat pump unit for low energy house and its application', 'PV effect in multilayer cells and blending of fullerene/poly (3-hexylthiophene) and phthalocyanine having NIR charge transfer absorption band', 'CdTe photovoltaic systems - an alternative energetic', 'Integration of renewable energy sources in a town, examples in Grenoble', 'A prospective analysis method for the conception of solar integration solutions in buildings' and 'Energy and aesthetic improvements for building integration of cost effective solar energy systems'. Further groups of presentations at the conference are reported on in separate database records. An index of authors completes the proceedings

  13. Movable air solar collector and its efficiency

    International Nuclear Information System (INIS)

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

  14. Evaluation of Test Method for Solar Collector Efficiency

    DEFF Research Database (Denmark)

    Fan, Jianhua; Shah, Louise Jivan; Furbo, Simon

    . The power produced by the solar collector during a test period is determined by the product of the specific heat, the mass flow rate and the temperature increase of the solar collector fluid. The solar collector efficiency is in the standard determined by measurements at different temperature levels. Based......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...

  15. 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.

  16. Local Reasoning about a Copying Garbage Collector

    DEFF Research Database (Denmark)

    Torp-Smith, Noah; Birkedal, Lars; Reynolds, John C.

    2008-01-01

    We present a programming language, model, and logic appropriate for implementing and reasoning about a memory management system. We state semantically what is meant by correctness of a copying garbage collector, and employ a variant of the novel separation logics to formally specify partial...... correctness of Cheney’s copying garbage collector in our program logic. Finally, we prove that our implementation of Cheney’s algorithm meets its specification using the logic we have given and auxiliary variables. Udgivelsesdato: 2008...

  17. Modelling the performance of fluorescent solar collectors

    OpenAIRE

    Fang, Liping; Parel, Thomas; Danos, Lefteris; Markvart, Tom

    2011-01-01

    The theoretical power conversion efficiency of a silicon solar cell with a fluorescent solar collector is believed to reach 90% of the maximum efficiency of an ideal silicon solar given by the Shockley-Queisser detailed balance limit, but the practical efficiencies are significantly lower due to several loss mechanisms. This work presents an analytic model which take the non-ideal coupling between the collector and the solar cell mounted at the edge into consideration and it is shown in ...

  18. Light trapping in fluorescent solar collectors

    OpenAIRE

    Soleimani, Nazila

    2012-01-01

    A fluorescent solar collector (FSC) is an optoelectronic waveguide device that can concentrate both diffuse and direct sunlight onto a solar cell which is then converted to electricity. Fluorescent collectors offer the potential to reduce the cost of crystalline silicon (c-Si) solar cells, but so far their effectiveness has been demonstrated only theoretically. The major problems in the device obtaining high practical efficiency are photon transport losses and material instability. This ...

  19. Increasing the Efficiency of a Thermionic Engine Using a Negative Electron Affinity Collector

    CERN Document Server

    Smith, Joshua Ryan

    2014-01-01

    Most attention to improving vacuum thermionic energy conversion device (TEC) technology has been on improving electron emission with little attention to collector optimization. A model was developed to characterize the output characteristics of a TEC where the collector features negative electron affinity (NEA). According to the model, there are certain conditions for which the space charge limitation can be reduced or eliminated. The model is applied to devices comprised of materials reported in the literature, and predictions of output power and efficiency are made, targeting the sub-1000K hot-side regime. By slightly lowering the collector barrier height, an output power of around $1kW$, at $\\geq 20%$ efficiency for a reasonably sized device ($\\sim 0.1m^{2}$ emission area) can be achieved.

  20. Analytical prediction with multidimensional computer programs and experimental verification of the performance, at a variety of operating conditions, of two traveling wave tubes with depressed collectors

    Science.gov (United States)

    Dayton, J. A., Jr.; Kosmahl, H. G.; Ramins, P.; Stankiewicz, N.

    1979-01-01

    Experimental and analytical results are compared for two high performance, octave bandwidth TWT's that use depressed collectors (MDC's) to improve the efficiency. The computations were carried out with advanced, multidimensional computer programs that are described here in detail. These programs model the electron beam as a series of either disks or rings of charge and follow their multidimensional trajectories from the RF input of the ideal TWT, through the slow wave structure, through the magnetic refocusing system, to their points of impact in the depressed collector. Traveling wave tube performance, collector efficiency, and collector current distribution were computed and the results compared with measurements for a number of TWT-MDC systems. Power conservation and correct accounting of TWT and collector losses were observed. For the TWT's operating at saturation, very good agreement was obtained between the computed and measured collector efficiencies. For a TWT operating 3 and 6 dB below saturation, excellent agreement between computed and measured collector efficiencies was obtained in some cases but only fair agreement in others. However, deviations can largely be explained by small differences in the computed and actual spent beam energy distributions. The analytical tools used here appear to be sufficiently refined to design efficient collectors for this class of TWT. However, for maximum efficiency, some experimental optimization (e.g., collector voltages and aperture sizes) will most likely be required.

  1. Atmospheric Ionic Deposition in Tropical Sites of Central Sulawesi Determined by Ion Exchange Resin Collectors and Bulk Water Collector

    OpenAIRE

    Köhler, S; Jungkunst, H.; Gutzler, C.; Herrera, R.; Gerold, G

    2012-01-01

    In the light of global change, the necessity to monitor atmospheric depositions that have relevant effects on ecosystems is ever increasing particularly for tropical sites. For this study, atmospheric ionic depositions were measured on tropical Central Sulawesi at remote sites with both a conventional bulk water collector system (BWS collector) and with a passive ion exchange resin collector system (IER collector). The principle of IER collector to fix all ionic depositions, i.e. anions and c...

  2. Two new designs of parabolic solar collectors

    Directory of Open Access Journals (Sweden)

    Karimi Sadaghiyani Omid

    2014-01-01

    Full Text Available In this work, two new compound parabolic trough and dish solar collectors are presented with their working principles. First, the curves of mirrors are defined and the mathematical formulation as one analytical method is used to trace the sun rays and recognize the focus point. As a result of the ray tracing, the distribution of heat flux around the inner wall can be reached. Next, the heat fluxes are calculated versus several absorption coefficients. These heat flux distributions around absorber tube are functions of angle in polar coordinate system. Considering, the achieved heat flux distribution are used as a thermal boundary condition. After that, Finite Volume Methods (FVM are applied for simulation of absorber tube. The validation of solving method is done by comparing with Dudley's results at Sandia National Research Laboratory. Also, in order to have a good comparison between LS-2 and two new designed collectors, some of their parameters are considered equal with together. These parameters are consist of: the aperture area, the measures of tube geometry, the thermal properties of absorber tube, the working fluid, the solar radiation intensity and the mass flow rate of LS-2 collector are applied for simulation of the new presented collectors. After the validation of the used numerical models, this method is applied to simulation of the new designed models. Finally, the outlet results of new designed collector are compared with LS-2 classic collector. Obviously, the obtained results from the comparison show the improving of the new designed parabolic collectors efficiency. In the best case-study, the improving of efficiency are about 10% and 20% for linear and convoluted models respectively.

  3. Solar collector design with respect to moisture problems

    DEFF Research Database (Denmark)

    Holck, Ole; Svendsen, Svend; Brunold, Stefan;

    2003-01-01

    Humidity inside the collectors is one factor that can be minimised to keep the most favourable microclimatic condition for the internal materials of the collector. This microclimate inside the collector is an important factor in determining the service lifetime of an absorber coating. During the ...... of the working group Materials in Solar Thermal Collectors of the International Energy Agency-Solar Heating and Cooling Programme....... design of the collector, the location and size of ventilation holes, properties of the insulation materials and dimension of the solar collector box are parameters that have to be taken into account for the optimisation in order to achieve the most favourable microclimate to prevent corrosion.......Simulation of the microclimate in solar thermal collectors can be a valuable tool for optimisation of the collector with respect to ventilation. A computer model has been established for fulfilling this. By using this tool the producers can be advised whether their solar collectors ought to be additionally...

  4. Capture of soft particles on electrostatically heterogeneous collectors: brushy particles.

    Science.gov (United States)

    Wen, Yicun; Guo, Xuhong; Kalasin, Surachate; Santore, Maria M

    2014-03-01

    This work investigated how particle softness can influence the initial adhesive capture of submicrometer colloidal particles from flow onto collecting surfaces. The study focused on the case dominated by potential attractions at the particle periphery (rather than, for instance, steric stabilization, requiring entropically costly deformations to access shorter-range van der Waals attractions.) The particles, "spherical polyelectrolyte brushes" with diameters in the range of 150-200 nm depending on the ionic strength, consisted of a polystyrene core and a corona of grafted poly(acrylic acid) chains, producing a relatively thick (20-40 nm) negative brushy layer. The adhesion of these particles was studied on electrostatically heterogeneous collecting surfaces: negatively charged substrates carrying flat polycationic patches made by irreversibly adsorbing the poly-l-lysine (PLL) polyelectrolyte. Variation in the amount of adsorbed PLL changed the net collector charge from completely negatively charged (repulsive) to positively charged (attractive). Adjustments in ionic strength varied the range of the electrostatic interactions. Comparing capture kinetics of soft brushy particles to those of similarly sized and similarly charged silica particles revealed nearly identical particle capture kinetics over the full range of collecting surface compositions at high ionic strengths. Even though the brushy particles contained an average of 5 vol % PAA in the brushy shell, with the rest being water under these conditions, their capture was indistinguishable from that of similarly charged rigid spheres. The brushy particles were, however, considerably less adherent at low ionic strengths where the brush was more extended, suggesting an influence of particle deformability or reduced interfacial charge. These findings, that the short time adhesion of brushy particles can resemble that of rigid particles, suggest that for bacteria and cell capture, modeling the cells as rigid

  5. Analytical prediction and experimental verification of performance at various operating conditions of a dual-mode traveling wave tube with multistage depressed collectors

    Science.gov (United States)

    Dayton, J. A., Jr.; Kosmahl, H. G.; Ramins, P.; Stankiewicz, N.

    1981-01-01

    A comparison of analytical and experimental results is presented for a high performance dual-mode traveling wave tube (TWT) operated over a wide range conditions. The computations are carried out with advanced multidimensional computer programs. These programs model the electron beam as a series of disks or rings of charge and follow their trajectories from the rf input of the TWT through the slow-wave structure refocusing system to their points of impacts in the depressed collector. TWT performance, collector efficiency, and collector current distribution are computed and compared with measurements. Very good agreement was obtained between computed and measured TWT performance and collector efficiencies, and the computer design of a highly efficient collector was demonstrated.

  6. Heat Pumps With Direct Expansion Solar Collectors

    Science.gov (United States)

    Ito, Sadasuke

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

  7. Asphalt solar collectors: A literature review

    International Nuclear Information System (INIS)

    Highlights: ► Solar energy can be harnessed by asphalt pavements. ► Research on asphalt thermal behavior and asphalt solar collectors is reviewed. ► Asphalt temperature is very sensitive to the variation of absortivity. ► Asphalt solar collector efficiency depends on flow rate and geometrical parameters. -- Abstract: Asphalt pavements subject to solar radiation can reach high temperatures causing not only environmental problems such as the heat island effect on cities but also structural damage due to rutting or hardening as a result of thermal cycles. Asphalt solar collectors are doubly effective active systems: as they solve the previously mentioned problems and, moreover, they can harness energy to be used in different applications. The main findings of the existing research on asphalt solar collectors are gathered together in this review paper. Firstly, the main heat transfer mechanisms involved in the solar energy collection process are identified and the most important parameters and variables are presented. After analyzing the theoretical foundations of the heat transfer process, this review focuses on the types of studies carried out so far on asphalt’s thermal behavior, different methodologies employed by other authors to study asphalt solar collectors and influence of the variables involved in thermal energy harvesting.

  8. Analysis of a plastic solar collector

    Energy Technology Data Exchange (ETDEWEB)

    Herce-Vigil, J.L.; Suarez, R. (Universidad Autonoma Metropolitana, Mexico City (Mexico))

    1991-01-01

    The use of solar energy, especially on a large scale, is very often inhibited by the collectors' cost. Thus, a simpler and less expensive collector could be considered as a contribution to development of this field. Since there is no pressure in the system, plastic seems to be a suitable construction material. This study comprises the analysis of heat transfer in a plate collector with a rectangular section built of a co-polymer of polyethylene and polypropylene and applies an analytical model to describe its behaviour. The 2-dimensional geometry offers the maximum area of contact between the fluid and the collecting surface exposed to the sun. Thermal boundary layer development is investigated. (author).

  9. ADVANCED HYBRID PARTICULATE COLLECTOR; FINAL

    International Nuclear Information System (INIS)

    A new concept in particulate control, called an advanced hybrid particulate collector (AHPC), is being developed under funding from the U.S. Department of Energy. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in an entirely novel manner. The AHPC concept combines fabric filtration and electrostatic precipitation in the same housing, providing major synergism between the two methods, both in the particulate collection step and in transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and solves the problem of reentrainment and re-collection of dust in conventional baghouses. Phase I of the development effort consisted of design, construction, and testing of a 5.7-m(sup 3)/min (200-acfm) working AHPC model. Results from both 8-hr parametric tests and 100-hr proof-of-concept tests with two different coals demonstrated excellent operability and greater than 99.99% fine-particle collection efficiency. Since all of the developmental goals of Phase I were met, the approach was scaled up in Phase II to a size of 255 m(sup 3)/min (9000 acfm) (equivalent in size to 2.5 MW) and was installed on a slipstream at the Big Stone Power Plant. For Phase II, the AHPC at Big Stone Power Plant was operated continuously from late July 1999 until mid-December 1999. The Phase II results were highly successful in that ultrahigh particle collection efficiency was achieved, pressure drop was well controlled, and system operability was excellent. For Phase III, the AHPC was modified into a more compact configuration, and components were installed that were closer to what would be used in a full-scale commercial design. The modified AHPC was operated from April to July 2000. While operational results were acceptable during this time, inspection of bags in the summer of 2000 revealed some membrane damage to the fabric that appeared to be

  10. Computer simulation of sulfhydryl collectors and their derivatives

    International Nuclear Information System (INIS)

    Present work is devoted to computer simulation of sulfhydryl collectors and their derivatives. Thus, the short chain carboxylic acids modified by dithio fragments are synthesized. Modified sulfhydryl collectors are synthesized as well. The properties of reagents are studied.

  11. Effects of collector types in sampling of atmospheric depositional fluxes

    International Nuclear Information System (INIS)

    The bulk gross alpha, gross beta and 7Be depositional fluxes were measured in Malaga (36.7 deg. N, 4.5 deg. W), a coastal Mediterranean station in the south of Spain for one whole year. In order to quantify the local variation of deposition rates, we have analysed the monthly results from two deposition collectors: a 'pot 'collector with a continuous water-covered surface and a 'funnel' collector. In general, the alpha and beta depositional fluxes from the funnel collector were approximately two times lower than the pot collector. Whereas for the cosmogenic 7Be, the depositional flux of 7Be from funnel collector was also approximately two times lower than the pot collector. A good correlation of the depositional flux of 7Be has been obtained from both collectors

  12. Solar Air Collectors: How Much Can You Save?

    Science.gov (United States)

    Newburn, J. D.

    1985-04-01

    A collector efficiency curve is used to determine the output of solar air collectors based on the testing of seven solar collectors sold in Iowa. In this application the solar heater is being used as a space heater for a house. The performance of the solar air heater was analyzed and an 8% savings in energy was achieved over a one year period using two 4 x 8 collectors in a typical house.

  13. PERFORMANCE EVALUATION OF SOLAR COLLECTORS USING A SOLAR SIMULATOR

    OpenAIRE

    M. Norhafana; Ahmad Faris Ismail; Z. A. A. Majid

    2015-01-01

    Solar water heating systems is one of the applications of solar energy. One of the components of a solar water heating system is a solar collector that consists of an absorber. The performance of the solar water heating system depends on the absorber in the solar collector. In countries with unsuitable weather conditions, the indoor testing of solar collectors with the use of a solar simulator is preferred. Thus, this study is conducted to use a multilayered absorber in the solar collector of...

  14. Analyze of meteorological data for development of solar collectors

    International Nuclear Information System (INIS)

    The objective of the research was to investigate the increase in heat yield, if the collector is tracking the sun, and to base the purposefulness of providing the collector device with additional equipment for keeping the surface of the collector perpendicular to the sun beams all the day round

  15. Theoretical study on a solar collector loop during stagnation

    DEFF Research Database (Denmark)

    Chen, Ziqian; Dragsted, Janne; Furbo, Simon;

    2010-01-01

    collector loop, the mass of the fluid flowing into the pressurized expansion vessel and the pressures at the top part and at the bottom part of the solar collector loop during stagnation for the solar collector loop are calculated. The theoretically calculated results are compared with experimental results...

  16. Theoretical study on a solar collector loop during stagnation

    DEFF Research Database (Denmark)

    Chen, Ziqian; Dragsted, Janne; Furbo, Simon;

    collector loop, the mass of the fluid flowing into the pressurized expansion vessel and the pressures at the top part and at the bottom part of the solar collector loop during stagnation for the solar collector loop are calculated. The theoretically calculated results are compared with experimental results...

  17. Adsorption mechanism of mixed cationic/anionic collectors in feldspar-quartz flotation system.

    Science.gov (United States)

    Vidyadhar, A; Hanumantha Rao, K

    2007-02-15

    The adsorption mechanism of mixed cationic alkyl diamine and anionic sulfonate/oleate collectors at acidic pH values was investigated on microcline and quartz minerals through Hallimond flotation, electrokinetic and diffuse reflectance FTIR studies. In the presence of anionic collectors, neither of the minerals responded to flotation but the diamine flotation of the minerals was observed to be pH and concentration dependent. The presence of sulfonate enhanced the diamine flotation of the minerals by its co-adsorption. The difference in surface charge between the minerals at pH 2 was found to be the basis for preferential feldspar flotation from quartz in mixed diamine/sulfonate collectors. The infrared spectra revealed no adsorption of sulfonate collector when used alone but displayed its co-adsorption as diamine-sulfonate complex when used with diamine. The presence of sulfonate increased the diamine adsorption due to a decrease in the electrostatic head-head repulsion between the adjacent surface ammonium ions and thereby increasing the lateral tail-tail hydrophobic bonds. The mole ratio of diamine/sulfonate was found to be an important factor in the orientation of alkyl chains and thus the flotation response of minerals. The increase in sulfonate concentration beyond diamine concentration leads to the formation of soluble 1:2 diamine-sulfonate complex or precipitate and the adsorption of these species decreased the flotation since the alkyl chains are in chaotical orientation with a conceivable number of head groups directing towards the solution phase. PMID:17098246

  18. Axial motion of collector plasma in a relativistic backward wave oscillator

    Science.gov (United States)

    Xiao, Renzhen; Chen, Changhua; Deng, Yuqun; Cao, Yibing; Sun, Jun; Li, Jiawei

    2016-06-01

    In this paper, it is proposed that plasma formed at the collector may drift back to the cathode and cause pulse shortening of the relativistic backward wave oscillator. Theoretical analysis shows that the axial drift velocity of plasma ions can be up to 5 mm/ns due to the presence of space charge potential provided by an intense relativistic electron beam. Particle-in-cell simulations indicate that the plasma electrons are initially trapped around the collector surface. With the accumulation of the plasma ions, a large electrostatic field forms and drives the plasma electrons to overcome the space charge potential and enter the beam-wave interaction region along the magnetic field lines. As a result, the beam current modulation is disturbed and the output microwave power falls rapidly. The plasma ions move in the beam-wave interaction region with an average axial velocity of 5-8 mm/ns. After the plasma ions reach the diode region, the emitted current at the cathode rises due to the charge neutralizations by the ions. The impedance collapse leads to further decrease of the microwave power. In experiments, when the diode voltage and beam current were 850 kV and 9.2 kA, and the collector radius was 2.15 cm, the output microwave power was 2.4 GW with a pulse width of less than 20 ns. The ion drift velocity was estimated to be about 5 mm/ns. After an improved collector with 3.35 cm radius was adopted, the pulse width was prolonged to more than 30 ns.

  19. An improved dynamic test method for solar collectors

    DEFF Research Database (Denmark)

    Kong, Weiqiang; Wang, Zhifeng; Fan, Jianhua;

    2012-01-01

    for the second-order differential term with 6–9min as the best averaging time interval. The measured and predicted collector power output of the solar collector are compared during a test of 13days continuously both for the ITF method and the QDT method. The maximum and averaging error is 53.87W/m2 and 5.22W/m2...... than the QDT method in predicting the power output of a solar collector.In conclusion, all the results show that the improved transfer function method can accurately and robustly estimate solar collector parameters and predict solar collector thermal performance under dynamic test conditions.......A comprehensive improvement of the mathematical model for the so called transfer function method is presented in this study. This improved transfer function method can estimate the traditional solar collector parameters such as zero loss coefficient and heat loss coefficient. Two new collector...

  20. 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...... in Europe. The collector parameters used as input in the tool are compiled from tests according to EN12975, without any intermediate conversions. The main target group for this tool is test institutes and certification bodies that are intended to use it for conversion of collector model parameters (derived...... from performance tests) into a more user friendly quantity: the annual energy output. The energy output presented in the tool is expressed as kWh per collector module. A simplified treatment of performance for PVT collectors is added based on the assumption that the thermal part of the PVT collector...

  1. Solar Heating Systems with Evacuated Tubular Solar Collector

    DEFF Research Database (Denmark)

    Qin, Lin; Furbo, Simon

    1998-01-01

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

  2. 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......, 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....... 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...

  3. A Self-Biasing Pulsed Depressed Collector

    Energy Technology Data Exchange (ETDEWEB)

    Kemp, Mark A.; Jensen, Aaron; Neilson, Jeff; /SLAC

    2014-05-29

    Depressed collectors have been utilized successfully for many years to improve the electrical efficiency of vacuum electron devices. Increasingly, pulsed, high-peak power accelerator applications are placing a premium on electrical efficiency. As RF systems are responsible for a large percentage of the overall energy usage at accelerator laboratories, methods to improve upon the state-of-the-art in pulsed high-power sources are desired. This paper presents a technique for self-biasing the stages in a multistage depressed collector. With this technique, the energy lost during the rise and fall times of the pulse can be recovered, separate power supplies are not needed, and existing modulators can be retrofitted. Calculations show that significant cost savings can be realized with the implementation of this device in high-power systems. In this paper, the technique is described along with experimental demonstration. (auth)

  4. Assessment of musculoskeletal load in refuse collectors

    Directory of Open Access Journals (Sweden)

    Zbigniew W. Jóźwiak

    2013-08-01

    Full Text Available Background: The aim of this work was to assess the load on the musculoskeletal system and its effects in the collectors of solid refuse. The rationale behind this study was to formulate proposals how to reduce excessive musculoskeletal load in this group of workers. Material and Methods: The study group comprised 15 refuse collectors aged 25 to 50 years. Data about the workplace characteristics and subjective complaints of workers were collected by the free interview and questionnaire. During the survey the photorecording of the workpostures, the distance and velocity by GPS recorders, measurements of forces necessary to move containers, energy expenditure (lung ventilation method, workload estimation using the Firstbeat system and REBA method and stadiometry were done. Results: The distance walked daily by the collectors operating in terms of 2 to 3 in urban areas was about 15 km, and in rural areas about 18 km. The most frequent musculoskeletal complaints concerned the feet (60% subjects, knees, wrists and shoulders (over 40% subjects. After work-shift all examined workers had vertebral column shorter by 10 to 14 mm (11.4 mm mean. Conclusions: The results of our study show that the refuse collectors are subjected to a very high physical load because of the work organization and the way it is performed. To avoid adverse health effects and overload it is necessary to undertake ergonomic interventions, involving training of workers to improve the way of their job performance, active and passive leisure, technical control of the equipment and refuse containers, as well as the renegotiation of contracts with clients, especially those concerning non-standard containers. Med Pr 2013;64(4:507–519

  5. Theoretical study of fluidized solar collector performance

    Energy Technology Data Exchange (ETDEWEB)

    Adulla, S. H; Kassem, M A; El-Refaie, M. F. [Cairo University, Giza (Egypt)

    2000-07-01

    This work presents a proposed novel design aiming to increasing the absorber-to-fluid heat transfer coefficient. This is accomplished by introducing small solid particles inside the collector tubes. When the collector liquid flows, it causes the particles to be fluidized and spread in the tubes. The particles material, size and total number should be turned together with the fluid mass flow rate to keep the bed, or particle dispersion, length within the physical length of collector tubes. Thus, the particles would be confined in the collector only; and not carried over to other parts of the circulation loop. While moving, the particles erode the thermal boundary layer formed on the tube inner surface, hence increasing the heat transfer coefficient. [Spanish] Este articulo presenta un diseno novedoso destinado a aumentar el coeficiente de trasferencia de calor de absorbedor a fluido. Esto se lleva a cabo mediante la introduccion de particulas solidas dentro de los tubos del colector. Cuando fluye el liquido del colector origina que las particulas se fluidicen y se diseminen en los tubos. El material de las particulas, tamano y numero total debera de ser puesto en movimiento junto con el regimen de flujo de masa de fluido para mantener el lecho o la dispersion de particulas por largo tiempo dentro de la longitud fisica de los tubos de colector. De esta manera las particulas seran confinadas solamente en el colector y no seran arrastradas a otras partes del anillo de circulacion. Al moverse, las particulas erosionan la capa de frontera termica formada en la superficie interior del tubo, aumentando por tanto el coeficiente de transmision de calor.

  6. Property Tax Collector Performance and Pay

    OpenAIRE

    Laurie J. Bates; Rexford E. Santerre

    1993-01-01

    The few empirical studies on the relationship between performance and pay in the public sector have been unable to measure adequately public sector output. This paper overcomes the measurement problem by focusing on the pay of the local property tax collector, for whom an output indicator - the property tax collection rate- can be objectively quantified and suggests that higher levels of performance causes an increase amount of pay, ceteris paribus.

  7. Enhancement of Integrated Solar Collector with Spherical Capsules PCM Affected by Additive Aluminum Powder

    Directory of Open Access Journals (Sweden)

    Fatah O. Al Ghuol

    2016-01-01

    Full Text Available This research aims to study, analyze, design, and construct a solar air heater combined with an appropriate phase-change material (PCM unit. This solar air heater is analogous to a collector integrating a thermal storage unit and a solar thermal collector. In this study, such single-pass solar air heater in amalgamation with PCM was constructed, and several tests were conducted on this device. During the experiments for the solar collector with PCM (spherical capsules, the temperature varied between 30°C and 35°C, and the air mass flow rate ranged between 0.03 and 0.09 kg/s. Results confirmed the predicted experimental findings. With the use of paraffin wax-aluminum composite, the thermal storage efficiency of the constructed solar air heater reached a maximum value of 71% at 0.05 kg/s mass flow rate, its charging time decreased by almost 70%, and its cooling rate increased. The thermal storage efficiency of the compound composite was 76.8% at 0.07 kg/s mass flow rate. The results also indicated that the time of charging decreased by almost 60% with the use of paraffin wax-aluminum composite.

  8. Metallic Fabrics as the Current Collector for High-Performance Graphene-Based Flexible Solid-State Supercapacitor.

    Science.gov (United States)

    Yu, Jianhui; Wu, Jifeng; Wang, Haozong; Zhou, Anan; Huang, Chaoqiang; Bai, Hua; Li, Lei

    2016-02-24

    Flexible solid-state supercapacitors attract more and more attention as the power supply for wearable electronics. To fabricate such devices, the flexible and economical current collectors are needed. In this paper, we report the stainless steel fabrics as the current collector for high-performance graphene-based supercapacitors. The stainless steel fabrics have superior properties compared with the widely used flexible current collectors. The flexible supercapacitors show large specific capacitance of 180.4 mF/cm(2), and capacitance retention of 96.8% after 7500 charge-discharge cycles. Furthermore, 96.4% of the capacitance is retained after 800 repeating stretching-bending cycles. The high performance is related to the excellent conductivity, good mechanical flexibility, and high electrochemical stability of the stainless steel fabrics. The achievement of such high-performance and flexible supercapacitor can open up exciting opportunities for wearable electronics and energy storage applications. PMID:26830192

  9. 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.

  10. High-strength clad current collector for silicon-based negative electrode in lithium ion battery

    Science.gov (United States)

    Kataoka, Riki; Oda, Yoshimitsu; Inoue, Ryouji; Kitta, Mitsunori; Kiyobayashi, Tetsu

    2016-01-01

    We develop a clad foil current collector with a high tensile strength that endures a large volume change in the active material during the charge and discharge, such as the Si-based materials. The nano-Si negative electrode with the clad current collector retains 76% of the initial capacity after 40 cycles, while the capacity of the nano-Si electrode with a conventional Cu foil drops to less than 70% only after 10 cycles. A full cell with the SiO negative electrode and the LiFePO4 positive electrode retains more than 90% of its capacity at the 10th cycle after 800 cycles. The conventional rolled Cu foil wrinkles during the cycling test. The high-strength clad current foil hardly deforms during the test regardless of the electrode size.

  11. Calculation of coolant flow in a nuclear reactor pressure collector

    International Nuclear Information System (INIS)

    Effect of output lattice resistance and a relative height of the collector on peculiarities of liquid flow and distribution of coolant flow rate in a distribution collector of a reactor has been investigated. Numerical integration of two-dimensional equations of coolant flow in a model of the distribution collector and in the inlet annular channel ignoring azimuthal perturbations at the inlet has been carried out. The calculations showed that, when increasing the relative height of the collector, the vortex was formed at the inlet of the collector due to the sudden flow rotation at the outlet from the inlet annular channel. The inlet vortex causes decrease of the flow rate at the collector periphery down to inverse stream formation. Application of displacers at the bottom of the collector leads to decreasing flow rate in the center and to levelling flow rate nonuniformity over the whole collector. Perturbation of only radial flow at the inlet leads to formation of vortices with the vertical axis near the center of the collector and to decrease of the rate at the outlet near the vortex region

  12. Stationary reflector-augmented flat-plate collectors

    Energy Technology Data Exchange (ETDEWEB)

    Chiam, H.F.

    1982-07-01

    A general procedure for determining the optimum geometry of a reflector-augmented solar collector which produces a desired pattern of flux-augmentation is described. The example used for illustration is a stationary collector whose winter performance is to be improved. Consideration of both a flat-plat collector with a bottom reflector and one with a top reflector led to distinct differences in their optimum configuration and performance being identified. Since either system can be used to augment winter flux a criterion for selecting the appropriate system is given. This criterion is based on the displacement in collector that from latitude inclination.

  13. Adaptive control of solar energy collector systems

    CERN Document Server

    Lemos, João M; Igreja, José M

    2014-01-01

    This book describes methods for adaptive control of distributed-collector solar fields: plants that collect solar energy and deliver it in thermal form. Controller design methods are presented that can overcome difficulties found in these type of plants:they are distributed-parameter systems, i.e., systems with dynamics that depend on space as well as time;their dynamics is nonlinear, with a bilinear structure;there is a significant level of uncertainty in plant knowledge.Adaptive methods form the focus of the text because of the degree of uncertainty in the knowledge of plant dynamics. Parts

  14. CMS DT Upgrade The Sector Collector Relocation

    CERN Document Server

    Navarro Tobar, Alvaro

    2015-01-01

    The Sector Collector relocation is the first stage of the upgrade program for the Drift Tubes subdetector of the CMS experiment. It was accomplished during Long Shutdown 2013-2014, and consisted in the relocation of the second-level trigger and readout electronics from the experimental to the service cavern, relieving the environmental constraints and improving accessibility for maintenance and upgrade. Extending the electrical links would degrade reliability, so the information is converted to optical with a custom system capable of dealing with the DC-unbalanced data. Initially, present electronics are used, so optical-to-copper conversion has also been installed.

  15. Simulation of a solar collector array consisting of two types of solar collectors, with and without convection barrier

    OpenAIRE

    Bava, Federico; Furbo, Simon; Perers, Bengt

    2015-01-01

    The installed area of solar collectors in solar heating fields is rapidly increasing in Denmark. In this scenario even relatively small performance improvements may lead to a large increase in the overall energy production. Both collectors with and without polymer foil, functioning as convection barrier, can be found on the Danish market. Depending on the temperature level at which the two types of collectors operate, one can perform better than the other. This project aimed to study the beha...

  16. DT results of TFTR's alpha collector

    International Nuclear Information System (INIS)

    An escaping alpha collector probe has been developed for TFTR's DT phase to complement the results of the lost alpha scintillator detectors which have been operating on TFTR since 1988. Measurements of the energy distribution of escaping alphas have been made by measuring the range of alphas implanted into nickel foils located within the alpha collector. Exposed samples have been analyzed for 4 DT plasma discharges at plasma currents of 1.0 and 1.8 MA. The results at 1.0 MA are in good agreement with predictions for first orbit alpha loss at 3.5 MeV. The 1.8 MA results, however, indicate a large anomalous loss of partially thermalized alphas at an energy ∼30% below the birth energy and at a total fluence nearly an order of magnitude above expected first orbit loss. This anomalous loss is not observed with the lost alpha scintillator detectors in DT plasmas but does resemble the anomalous delayed loss seen in DD plasmas. Several potential explanations for this loss process are examined. None of the candidate explanations proposed thus far are fully consistent with the anomalous loss observations

  17. Combined current collector and electrode separator

    Science.gov (United States)

    Gerenser, Robert J.; Littauer, Ernest L.

    1983-01-01

    This relates to reactive metal cells wherein there is a cathode and a consumable anode. It is necessary to separate the cathode from the anode so that an electrolyte may constantly flow over the face of the anode opposing the cathode. It has been found that this separator may also beneficially function as a current collector. The combined current collector and separator includes a peripheral supporting frame of which a portion may function as a bus-bar. A plurality of bars or ribs extend in parallel relation across the opening defined by the supporting frame and are electrically connected to the bus-bar portion. It is preferred that each bar or rib have a pointed or line edge which will engage and slightly bite into the associated anode to maintain the bar or rib in electrical contact with the anode. This abstract forms no part of the specification of this application and is not to be construed as limiting the claims of the application.

  18. Model of transit time for SiGe HBT Collector junction depletion-layer

    Institute of Scientific and Technical Information of China (English)

    Hu Hui-Yong; Zhang He-Ming; Dai Xian-Ying; Jia Xin-Zhang; Cui Xiao-Ying; Wang Wei; Ou Jian-Feng; Wang Xi-Yuan

    2005-01-01

    The transit time through collector junction depletion-layer is an important parameter that influences AC gain and frequency performance. In SiGe heterojunction bipolar transistor (HBT) collector junction, the depletion-layer width is given in three cases. The models of collector depletion-layer transit time, considering the collector current densities and base extension effect, are established and simulated using MATLAB. The influence of the different collector j unction bias voltage, collector concentration of As or P dopant and collector width on collector junction transit time is quantitatively studied. When the collector junction bias voltage, collector doping concentration and collector width are large, the transit time is quite long. And, from the results of simulations, the influence of the collector depletion-layer transit time on frequency performance is considerable in SiGe HBT with a thin base, so it could not be ignored.

  19. Parallel Tandems of Dye Sensitized Solar Cells with CNT Collector

    Science.gov (United States)

    Velten, Josef; Yuan, Chao-Chen; Zakhidov, Anvar

    2009-03-01

    In this presentation, we demonstrate the fabrication of monolithic parallel tandem dye sensitized solar cells using a semitransparent layer of carbon nanotubes. Each DSC sub-cell has titania photoelectrode with two different dyes: N 719 and N 749, which absorb light in different parts of solar spectrum. This layer of carbon nanotubes laminated on highly porous polymeric Millipore filter acts as both the collector of charge carrier and as the catalyst of the I/I3^- redox reaction that completes the function of the cell, overall allowing easier fabrication for tandem solar cell devices, with a potential for creating flexible devices in the future. The parallel tandem shows the total photocurrent which is nearly the sum of two Isc currents of constituent cells, and total Voc, which is average of two Voc, while conventional in-series DSC tandems show the lowest Voc and slightly increased Isc[1]. Thus the higher efficiency can be achieved in parallel DSC tandems, and we discuss the physical reasons for this effect. [1] Yanagida, et.al. J. of Photochemistry and Photobiology A: Chemistry Volume 164, Issues 1-3, 1 June 2004, Pages 33-39

  20. The Flotation of Kyanite and Sillimanite with Sodium Oleate as the Collector

    Directory of Open Access Journals (Sweden)

    Junxun Jin

    2016-08-01

    Full Text Available Kyanite and sillimanite are two polymorphic minerals with the same formula of Al2SiO5, but different crystal structures. Despite their high economic values, selectively recovering them by flotation is a challenge. In this study, the flotation behaviors of the two minerals with sodium oleate as the collector were examined at different pH conditions. Zeta potential measurement, infrared spectroscopic measurement, chemical speciation and X-ray photoelectron spectroscopy measurement were conducted to identify the underpinning mechanisms. It is found that the flotation behavior of both minerals is different under the same flotation condition. The flotation recovery of sillimanite is much higher than that of kyanite in the presence of the collector sodium oleate. Sodium oleate adsorbs onto the surfaces of kyanite and sillimanite mainly through the chemical interaction of the ionic–molecular dimers with aluminum atoms at pH 8.0. The higher sillimanite flotation recovery between the two minerals is related to the higher electrostatic charge densities of the aluminum atoms in six-fold coordination, which leads to the higher collector adsorption.

  1. Design and performance verification of advanced multistage depressed collectors

    Science.gov (United States)

    Kosmahl, H. G.; Ramins, P.

    1975-01-01

    Design and performance of a small size, 4 stage depressed collector are discussed. The collector and a spent beam refocusing section preceding it are intended for efficiency enhancement of octave bandwidth, high CW power traveling wave tubes for use in ECM.

  2. ANALYSIS AND MODELING OF SOLAR EVAPORATOR-COLLECTOR

    Directory of Open Access Journals (Sweden)

    Zakaria Mohd. Amin

    2015-11-01

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

  3. Carbon-brush collector maintenance on turbine-generators

    Energy Technology Data Exchange (ETDEWEB)

    Maughan, C.V. [Maughan Engineering Consultants, Schenectady, NY (United States)

    2005-07-01

    Carbon-brush collectors are small components in turbine generators that perform the function of transferring current from excitation power sources to the rotating fields of synchronous generators. Collectors operate at 100 to 700 volts DC in a noisy and windy atmosphere and are one of the most frequent causes of generator forced outages. As such, their condition must be monitored regularly through visual inspection. While the inspection and maintenance effort is relatively minor, it is often overlooked or done improperly. The key to reliable collector performance consists of making daily direct observations, recognizing the warning signals of impending failure, and taking timely corrective maintenance action. Dependable brush-to-collector current transfer relies on the following 3 conditions, which must be satisfied simultaneously: collector surface film; brush contact pressure; and continuous brush-to-ring contact. Causes of collector outages include planned outages to resurface the collector, or forced outages due to collector flashover. This paper presented suggestions on how to identify an impending failure, along with guidelines for corrective maintenance to avoid a turbine/generator forced outage. Information was provided on retrofit or fixed brush holders with removable brush holders. A checklist for daily inspection and weekly maintenance was presented along with measures to perform at each shutdown. 1 tab., 12 figs.

  4. 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.

  5. Preliminary design package for solar collector and solar pump

    Science.gov (United States)

    1978-01-01

    A solar-operated pump using an existing solar collector, for use on solar heating and cooling and hot water systems is described. Preliminary design criteria of the collector and solar-powered pump is given including: design drawings, verification plans, and hazard analysis.

  6. Influence of the amount of collector on ion flotation of niobium

    International Nuclear Information System (INIS)

    Flotation methods based on chemical interaction of the metal ion to be extracted (colligend) with an oppositely charged surfactant ion (collector) are now attracting attention increasingly in purification of wastewaters. Extraction of small amounts of metals by flotation from industrial wastes provides solutions of problems associated with prevention of pollution of natural water supplies by toxic pollutants, and also with concentration of valuable elements for subsequent utilization. Niobium is one such metal, extraction of which from aqueous solutions is of considerable interest. The results of an experimental study of the influence of the amount of flotation reagent on ion flotation of niobates are discussed in this paper

  7. 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).

  8. 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.

  9. Test results, Industrial Solar Technology parabolic trough solar collector

    Energy Technology Data Exchange (ETDEWEB)

    Dudley, V.E. [EG and G MSI, Albuquerque, NM (United States); Evans, L.R.; Matthews, C.W. [Sandia National Labs., Albuquerque, NM (United States)

    1995-11-01

    Sandia National Laboratories and Industrial Solar Technology are cost-sharing development of advanced parabolic trough technology. As part of this effort, several configurations of an IST solar collector were tested to determine the collector efficiency and thermal losses with black chrome and black nickel receiver selective coatings, combined with aluminized film and silver film reflectors, using standard Pyrex{reg_sign} and anti-reflective coated Pyrex{reg_sign} glass receiver envelopes. The development effort has been successful, producing an advanced collector with 77% optical efficiency, using silver-film reflectors, a black nickel receiver coating, and a solgel anti-reflective glass receiver envelope. For each receiver configuration, performance equations were empirically derived relating collector efficiency and thermal losses to the operating temperature. Finally, equations were derived showing collector performance as a function of input insolation value, incident angle, and operating temperature.

  10. Mathematical modelling of unglazed solar collectors under extreme operating conditions

    DEFF Research Database (Denmark)

    Bunea, M.; Perers, Bengt; Eicher, S.;

    2015-01-01

    average temperature levels at the evaporator. Simulation of these systems requires a collector model that can take into account operation at very low temperatures (below freezing) and under various weather conditions, particularly operation without solar irradiation.A solar collector mathematical model......Combined heat pumps and solar collectors got a renewed interest on the heating system market worldwide. Connected to the heat pump evaporator, unglazed solar collectors can considerably increase their efficiency, but they also raise the coefficient of performance of the heat pump with higher...... was found due to the condensation phenomenon and up to 40% due to frost under no solar irradiation. This work also points out the influence of the operating conditions on the collector's characteristics.Based on experiments carried out at a test facility, every heat flux on the absorber was separately...

  11. Simulation of a solar collector array consisting of two types of solar collectors, with and without convection barrier

    DEFF Research Database (Denmark)

    Bava, Federico; Furbo, Simon; Perers, Bengt

    2015-01-01

    composition of the row. Actual solar collectors available on the Danish market (models HT-SA and HT-A 35-10 manufactured by ARCON Solar A/S) were used for this analysis. To perform the study, a simulation model in TRNSYS was developed based on the Danish solar collector field in Braedstrup. A parametric...

  12. Study of Cylindrical Honeycomb Solar Collector

    Directory of Open Access Journals (Sweden)

    Atish Mozumder

    2014-01-01

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

  13. Analysis of WWER 1000 collector cracking mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Matocha, K.; Wozniak, J. [Vitkovice J.S.C., Ostrava (Switzerland)

    1997-12-31

    The presentation reviews the large experimental program, started in 1993 in Vitkovice, where the main aim was: (1) a detailed study of strain and thermal ageing, dissolved oxygen content and temperature on subcritical crack growth in 10NiMo8.5 (10GN2MFA) steel, (2) a detailed study of the effect of high temperature water and tube expansion technology on fracture behaviour of ligaments between holes for heat exchange tubes, and (3) a detailed study of the effect of drilling, tube expansion technology and heat treatment on residual stresses on the surface of holes for heat exchange tubes. The aim of all these investigations was to find a dominant damage mechanism responsible for collector cracking to be able to judge the efficiency of implemented modifications and suggested countermeasures and to answer a very important question whether proper operation conditions (mainly water chemistry) make the operation of steam generators made in Vitcovice safe throughout the planned lifetime. 10 refs.

  14. PERFORMANCE EVALUATION OF SOLAR COLLECTORS USING A SOLAR SIMULATOR

    Directory of Open Access Journals (Sweden)

    M. Norhafana

    2015-11-01

    Full Text Available Solar water heating systems is one of the applications of solar energy. One of the components of a solar water heating system is a solar collector that consists of an absorber. The performance of the solar water heating system depends on the absorber in the solar collector. In countries with unsuitable weather conditions, the indoor testing of solar collectors with the use of a solar simulator is preferred. Thus, this study is conducted to use a multilayered absorber in the solar collector of a solar water heating system as well as to evaluate the performance of the solar collector in terms of useful heat of the multilayered absorber using the multidirectional ability of a solar simulator at several values of solar radiation. It is operated at three variables of solar radiation of 400 W/m2, 550 W/m2 and 700 W/m2 and using three different positions of angles at 0º, 45º and 90º. The results show that the multilayer absorber in the solar collector is only able to best adapt at 45° of solar simulator with different values of radiation intensity. At this angle the maximum values of useful heat and temperature difference are achieved. KEYWORDS: solar water heating system; solar collector; multilayered absorber; solar simulator; solar radiation 

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

    Energy Technology Data Exchange (ETDEWEB)

    Mattox, D. L.

    1979-06-01

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

  16. Thermal Stress Analysis of 1 MW Gyrotron Collector

    International Nuclear Information System (INIS)

    At the DIII-D tokamak, up to 6 gyrotrons supply ECH power to the plasma. Each gyrotron injects 800 kW for 5 s at the tokamak during normal operation and are designed to generate 1 MW for 10 s pulse lengths. A power of ∼ 2000 kW is absorbed by the collector of each gyrotron from the electron beam. The gyrotrons are manufactured by Communications and Power Industries (CPI). The collectors are 0.6 m diameter cylinders, 60 cm in height. The collector walls are 20.7 mm thick and have 196 coolant holes of 5.3 mm diameter. Each pair of adjacent coolant holes is connected in series to provide 98 cooling paths. The collector material is oxygen free high conductivity copper (OFHC) and the collectors are cooled by water at a design flow rate of 300 gpm. In order to reduce the peak thermal load on the collector walls, the beam is swept over the collector wall at 4 Hz and an amplitude of about 15 cm using an external coil. Sweeping reduces the effective peak heat flux from 1400 W/cm2 to 600 W/cm2. During 2004 and 2005, some of the collectors failed due to stress cracks. In order to investigate reasons for these failures, a nonlinear elastic plastic thermal stress analysis of the collector was undertaken. The thermal stress analysis results indicated that the effective strain for OFHC material under the operating conditions limited the cycle life of the collector due to fatigue, resulting in failures. The desired service life of more than 105 thermal cycles can be obtained by 1) operational changes, such as: increasing the frequency and amplitude of sweeping to reduce the average heat flux, 2) design changes, such as: increasing the height and/or diameter of collector, enhancing the heat transfer coefficient by roughening the coolant channel walls or 3) changing the material of the collector to dispersion strengthened copper such as Glidcop. The analysis and conclusions will be presented. (author)

  17. 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...

  18. 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.

  19. FLOW DISTRIBUTION IN A SOLAR COLLECTOR PANEL WITH HORIZONTAL FINS

    DEFF Research Database (Denmark)

    Fan, Jianhua; Shah, Louise Jivan; Furbo, Simon

    2005-01-01

    The objective of this work is to theoretically and experimentally investigate the flow and temperature distribution in a solar collector panel with an absorber consisting of horizontal fins. Fluid flow and heat transfer in the collector panel are studied by means of computational fluid dynamics...... (CFD) calculations. Further, experimental investigations of a 12.5 m² solar collector panel with 16 parallel connected horizontal fins are carried out. The flow distribution through the absorber is evaluated by means of temperature measurements on the backside of the absorber tubes. The measured...

  20. Garbage Collector Verification for Proof-Carrying Code

    Institute of Scientific and Technical Information of China (English)

    Chun-Xiao Lin; Yi-Yun Chen; Long Li; Bei Hua

    2007-01-01

    We present the verification of the machine-level implementation of a conservative variant of the standard mark-sweep garbage collector in a Hoare-style program logic. The specification of the collector is given on a machine-level memorymodel using separation logic, and is strong enough to preserve the safety property of any common mutator program. Ourverification is fully implemented in the Coq proof assistant and can be packed immediately as foundational proof-carryingcode package. Our work makes important attempt toward building fully certified production-quality garbage collectors.

  1. 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.

  2. Performance of solar collectors under low temperature conditions

    DEFF Research Database (Denmark)

    Bunea, Mircea; Eicher, Sara; Hildbrand, Catherine;

    evaluated and results compared to experimental measurements. A mathematical model is also under development to include, in addition to the condensation phenomena, the frost, the rain and the long-wave radiation gains/losses on the rear of the solar collector. While the potential gain from rain was estimated......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...

  3. Flotation behavior of four dodecyl tertiary amines as collectors of diaspore and kaolinite

    Institute of Scientific and Technical Information of China (English)

    Changmiao Liu; Feng Ansheng; GUO Zhenxu; Cao Xuefeng; Hu Yuehua

    2011-01-01

    The flotation of diaspore and kaolinite by one of a series of tertiary amines (DRN, DEN, DPN and DBN) was investigated. The tertiary amines show better floating recovery for kaolinite compared to diaspore. The maximum recovery D-value is 45% over a pH range from 3 to 8. FT-IR spectra confirm the presence of hydroxyl groups on the surface of kaolinite and diaspore. Zeta potential measurements show that the mineral surfaces are negatively charged over a wide pH range. Ionization of hydroxyl groups mainly accounts for the surface charging mechanism. The adsorption of tertiary amines onto the mineral surface is due mainly to electrostatic effects and the difference in electrostatic effect between a collector and the two minerals can explain the flotation separation. Inductive electronic and steric effects from the substituent groups result in different collecting powers for the four tertiary amines.

  4. Concentrating vanadium compounds with the aid of a perfluorinated collector

    International Nuclear Information System (INIS)

    The authors report the results of experiments on extraction of vanadium compounds from aqueous solutions. A cationic flourine-containing surfactant was used as the collector. Figures show the dependence of the degree of vanadium extraction on the solution pH, and the dependence of the composition of the vanadium-containing precipitate on the amount of collector C /SUB surf/ . It was shown that it is possible in principle to concentrate vanadium compounds from aqueous solutions with the aid of a cationic perflourinated collector. The optimal conditions of vanadium extraction lie in the pH range 2.5-4.5. Interaction of decavanadates with the surfactant may proceed by an ion-exchange mechanism under certain conditions. Maximum metal content in the precipitate corresponds to the stoichiometric consumption of the collector. The hydrophobic precipitate can be seperated from the solution equally effectively by flotation and by filtration

  5. Optical, Energetic and Exergetic Analyses of Parabolic Trough Collectors

    Institute of Scientific and Technical Information of China (English)

    (O)ZT(U)RK Murat; (C)(I)(C)EK BEZ(I)R Nalan; (O)ZEK Nuri

    2007-01-01

    Parabolic trough collectors generate thermal energy from solar energy. Especially, they are very convenient for applications in high temperature solar power systems. To determine the design parameters, parabolic trough collectors must be analysed with optical analysis. In addition, thermodynamics (energy and exergy) analysis in the development of an energy efficient system must be achieved. Solar radiation passes through Earth's atmosphere until it reaches on Earth's surface and is focused from the parabolic trough collector to the tube receiver with a transparent insulated envelope. All of them constitute a complex mechanism. We investigate the geometry of parabolic trough reflector and characteristics of solar radiation to the reflecting surface through Earth's atmosphere, and calculate the collecting total energy in the receiver. The parabolic trough collector,of which design parameters are given, is analysed in regard to the energy and exergy analysis considering the meteorological specification in May, June, July and August in Isparta/Turkey, and the results are presented.

  6. Performance Simulation Comparison for Parabolic Trough Solar Collectors in China

    OpenAIRE

    Jinping Wang; Jun Wang; Xiaolong Bi; Xiang Wang

    2016-01-01

    Parabolic trough systems are the most used concentrated solar power technology. The operating performance and optical efficiency of the parabolic trough solar collectors (PTCs) are different in different regions and different seasons. To determine the optimum design and operation of the parabolic trough solar collector throughout the year, an accurate estimation of the daily performance is needed. In this study, a mathematical model for the optical efficiency of the parabolic trough solar col...

  7. 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.

  8. Thermal Evaluation of a Solarus PV-T collector

    OpenAIRE

    Haddi, Jihad

    2013-01-01

    Low concentrator PV-T hybrid systems produce both electricity and thermal energy; this fact increases the overall efficiency of the system and reduces the cost of solar electricity. These systems use concentrators which are optical devices that concentrate sunlight on to solar cells and reduce expensive solar cell area. This thesis work deals with the thermal evaluation of a PV-T collector from Solarus.Firstly the thermal efficiency of the low concentrator collector was characterized for the ...

  9. Thermal efficiency of single-pass solar air collector

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, Zamry; Ibarahim, Zahari; Yatim, Baharudin [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor Darul Ehsan (Malaysia); Ruslan, Mohd Hafidz [Solar Energy Research Institute (SERI), Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor Darul Ehsan (Malaysia)

    2013-11-27

    Efficiency of a finned single-pass solar air collector was studied. This paper presents the experimental study to investigate the effect of solar radiation and mass flow rate on efficiency. The fins attached at the back of absorbing plate to improve the thermal efficiency of the system. The results show that the efficiency is increased proportional to solar radiation and mass flow rate. Efficiency of the collector archived steady state when reach to certain value or can be said the maximum performance.

  10. Research On Solar Energy Collector With Cell Polycarbonate Absorber

    OpenAIRE

    Putāns, Henriks; Zagorska, Viktorija; Ziemelis, Imants; Jesko, Zanis

    2015-01-01

    A flat plate solar collector with cell polycarbonate absorber and transparent cover has been made and its experimental investigation carried out. The collector consists of a wooden box, into which, a layer of heat insulation with a mirror film and 4 mm thick cell polycarbonate sheet, as the absorber, are placed. The coherence between collector’s efficiency, heat carrier and ambient air temperature, as well as intensity of the solar radiation and heat power in the experimental investigation ha...

  11. Ventilation and hot water supply solar-heat collector

    OpenAIRE

    Овсянникова, Ирина Михайловна; Немировский, Илья Абрамович; Ганжа, Антон Николаевич

    2014-01-01

    Solar collectors intended for hot water supply needs are widely used today. However, the territorial position of Ukraine prevents their efficient use during the cold period of the year. This reduces their utilization factor and increases the payback period. The use of solar collectors as the recuperators of exhaust air will allow for their efficient operation during the heating season. This becomes possible because the cold air is heated by the indoor waste air heat particularly in the solar ...

  12. Shape Control of Solar Collectors Using Shape Memory Alloy Actuators

    Science.gov (United States)

    Lobitz, D. W.; Grossman, J. W.; Allen, J. J.; Rice, T. M.; Liang, C.; Davidson, F. M.

    1996-01-01

    Solar collectors that are focused on a central receiver are designed with a mechanism for defocusing the collector or disabling it by turning it out of the path of the sun's rays. This is required to avoid damaging the receiver during periods of inoperability. In either of these two cases a fail-safe operation is very desirable where during power outages the collector passively goes to its defocused or deactivated state. This paper is principally concerned with focusing and defocusing the collector in a fail-safe manner using shape memory alloy actuators. Shape memory alloys are well suited to this application in that once calibrated the actuators can be operated in an on/off mode using a minimal amount of electric power. Also, in contrast to other smart materials that were investigated for this application, shape memory alloys are capable of providing enough stroke at the appropriate force levels to focus the collector. Design and analysis details presented, along with comparisons to test data taken from an actual prototype, demonstrate that the collector can be repeatedly focused and defocused within accuracies required by typical solar energy systems. In this paper the design, analysis and testing of a solar collector which is deformed into its desired shape by shape memory alloy actuators is presented. Computations indicate collector shapes much closer to spherical and with smaller focal lengths can be achieved by moving the actuators inward to a radius of approximately 6 inches. This would require actuators with considerably more stroke and some alternate SMA actuators are currently under consideration. Whatever SMA actuator is finally chosen for this application, repeatability and fatigue tests will be required to investigate the long term performance of the actuator.

  13. Possibility of Modeling of Solar Collectors Systems in Latvia

    OpenAIRE

    Šipkovs, P; Migla, L

    2010-01-01

    The aim of the work is to explore suitability of Latvian environment to the usage of solar collectors system. For the attainment of objective monotype house will be modeled, the house will be equipped with the combined solar heat system, which will be placed in different regions. There are diverse amount of sunny days in different regions, as well as diverse average temperature, wherewith the amount of heat differs. For the modeling of building, modeling program model of solar collectors will...

  14. ADVANCED HYBRID PARTICULATE COLLECTOR - PHASE III

    International Nuclear Information System (INIS)

    A new concept in particulate control, called an advanced hybrid particulate collector (AHPC), is being developed under funding from the U.S. Department of Energy. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration. The AHPC concept consists of a combination of fabric filtration and electrostatic precipitation in the same housing, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emission with conventional ESPs, and it solves the problem of reentrainment and re-collection of dust in conventional baghouses. In Phase II, a 2.5-MW-scale AHPC was designed, constructed, installed, and tested at the Big Stone power plant. For Phase III, further testing of an improved version of the 2.5-MW-scale AHPC at the Big Stone power plant is being conducted to facilitate commercialization of the AHPC technology

  15. Parabolic Trough Solar Collector Initial Trials

    Directory of Open Access Journals (Sweden)

    Ghalya Pikra

    2012-03-01

    Full Text Available This paper discusses initial trials of parabolic trough solar collector (PTSC in Bandung. PTSC model consists of concentrator, absorber and tracking system. Concentrator designs are made with 2m aperture width, 6m length and 0.75m focal distance. The design is equipped with an automatic tracking system which is driven using 12V and 24Watt DC motor with 0.0125rpm rotational speed. Absorber/receiver is designed with evacuated tube type, with 1 inch core diameter and tube made of AISI304 and coated with black oxide, the outer tube is borosilicate glass with a 70 mm diameter and 1.5 m length. Working fluid stored in single type of thermal storage tank, a single phase with 37.7 liter volume. PTSC model testing carried out for 2 hours and 10 minutes produces heat output and input of 11.5 kW and 0.64 kW respectively. 

  16. Performance evaluation for solar collectors in Taiwan

    International Nuclear Information System (INIS)

    In this paper, the global irradiation observed in Taiwan from 1990 to 1999 was used to estimate the optimal tilt angle for solar collectors. The observed data are resolved into diffusion and beam components, and transformed into instantaneous time frames using mathematical models. The energy gain on installing a single-axis tracked panel as compared to a traditional fixed panel is originally analyzed theoretically. In addition to the observation data, both types of radiation will be taken into account for comparison, i.e. both extraterrestrial radiation and global radiation predicted using empirical models. The results show that the yearly optimal angles for six selected stations are about 0.95 and 0.88 times their latitudes for extraterrestrial and predicted radiation, respectively. All of the observed irradiations are less than the predicted values for all times and stations, consequently resulting in a flatter tilt angle, with a few exceptions in summer. Since Taipei has the lowest clearness index, its yearly optimal angle calculated from observed data shows the greatest discrepancy when compared to its latitude. By employing a tracked panel, the yearly gains calculated from the observed data lie between 14.3% and 25.3%, which is significantly less than those from the extraterrestrial and predicted radiations

  17. Analysis of solar collector array systems using thermography

    Energy Technology Data Exchange (ETDEWEB)

    Eden, A.

    1980-01-01

    The use of thermography to analyze large solar collector array systems under dynamic operating conditions is discussed. The research has focused on thermographic techniques and equipment to determine temperature distributions, flow patterns, and air blockages in solar collectors. The results of this extensive study, covering many sites and types of collectors, illustrate the capabilities of infrared analysis as an analysis tool and operation and maintenance procedure when applied to large arrays. Thermographic analysis of most collector systems showed temperature distributions that indicated balanced flow patterns with both the thermographs and the hand-held unit. In three significant cases, blocked or broken collector arrays, which previously had gone undetected, were discovered. Using this analysis, validation studies of large computer codes could examine collector arrays for flow patterns or blockages that could cause disagreement between actual and predicted performance. Initial operation and balancing of large systems could be accomplished without complicated sensor systems not needed for normal operations. Maintenance personnel could quickly check their systems without climbing onto the roof and without complicated sensor systems.

  18. Dual curvature acoustically damped concentrating collector. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Smith, G.A.; Rausch, R.A.

    1980-05-01

    A development program was conducted to investigate the design and performance parameters of a novel, dual curvature, concentrating solar collector. The reflector of the solar collector is achieved with a stretched-film reflective surface that approximates a hyperbolic paraboloid and is capable of line-focusing at concentration ratios ranging from 10 to 20X. A prototype collector was designed based on analytical and experimental component trade-off activities as well as economic analyses of solar thermal heating and cooling systems incorporating this type of collector. A prototype collector incorporating six 0.66 x 1.22 m (2 x 4 ft) was fabricated and subjected to a limited thermal efficiency test program. A peak efficiency of 36% at 121/sup 0/C (250/sup 0/F) was achieved based upon the gross aperture area. Commercialization activities were conducted, including estimated production costs of $134.44/m/sup 2/ ($12.49/ft/sup 2/) for the collector assembly (including a local suntracker and controls) and $24.33/m/sup 2/ ($2.26/ft/sup 2/) for the reflector subassembly.

  19. Ray-tracing software comparison for linear focusing solar collectors

    Science.gov (United States)

    Osório, Tiago; Horta, Pedro; Larcher, Marco; Pujol-Nadal, Ramón; Hertel, Julian; van Rooyen, De Wet; Heimsath, Anna; Schneider, Simon; Benitez, Daniel; Frein, Antoine; Denarie, Alice

    2016-05-01

    Ray-Tracing software tools have been widely used in the optical design of solar concentrating collectors. In spite of the ability of these tools to assess the geometrical and material aspects impacting the optical performance of concentrators, their use in combination with experimental measurements in the framework of collector testing procedures as not been implemented, to the date, in none of the current solar collector testing standards. In the latest revision of ISO9806 an effort was made to include linear focusing concentrating collectors but some practical and theoretical difficulties emerged. A Ray-Tracing analysis could provide important contributions to overcome these issues, complementing the experimental results obtained through thermal testing and allowing the achievement of more thorough testing outputs with lower experimental requirements. In order to evaluate different available software tools a comparison study was conducted. Taking as representative technologies for line-focus concentrators the Parabolic Trough Collector and the Linear Fresnel Reflector Collector, two exemplary cases with predefined conditions - geometry, sun model and material properties - were simulated with different software tools. This work was carried out within IEA/SHC Task 49 "Solar Heat Integration in Industrial Processes".

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

    DEFF Research Database (Denmark)

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

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

    DEFF Research Database (Denmark)

    Fan, Jianhua; Chen, Ziqian; Furbo, Simon;

    2009-01-01

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

  2. Arrangement of Multirow Solar Collector Array on Limited Roof Width

    Institute of Scientific and Technical Information of China (English)

    PU Shaoxuan; XIA Chaofeng

    2010-01-01

    At the limited roof north-south(N-S)width of a building,for the array with multirow collectors based on no shading at winter solstice noon and sloped at latitude,this paper studied the shading and the radiant energy striking on solar collector array.Based on Kunming solar radiation data,the annual and monthly solar radiant energy striking on multi-array collectors was analyzed and estimated,from no shading to partial shading by adding 1-3 collector row,at the slopes of 10°,15°,20°,25°,30°,35° and 40°,respectively.The results showed that properly increasing the row number by reducing the slope of collectors was reasonable in order to get more annual radiant energy.Adding 1 row at 10° of slope was economical for Kunming,based on the 5-row array at 25°.And adding collector row by 20% at 10° of slope could increase the radiant energy striking on the array by 19%.

  3. Demonstration of Three Large Scale Solar Process Heat Applications with Different Solar Thermal Collector Technologies

    OpenAIRE

    Pietruschka Dirk, Fedrizzi Roberto, Orioli Francesco, Söll Robert, Stauss Reiner

    2012-01-01

    The recently started European FP7 Project InSun aims to demonstrate the reliability and efficiency of three different collector technologies suitable for industrial process heat supply in different climatic regions. The technologies demonstrated reach from improved flat-plate collectors for supply temperatures of up to 95 °C in moderate northern Europe climate to tracked concentrating collectors (linear Fresnel collectors and parabolic trough collectors) for supply temperatures betwe...

  4. Solar Thermal Collectors at High Latitudes : Design and performance of non-tracking concentrators

    OpenAIRE

    Adsten, Monika

    2002-01-01

    Solar thermal collectors at high latitudes have been studied, with emphasis on concentrating collectors. A novel design of concentrating collector, the Maximum Reflector Collector (MaReCo), especially designed for high latitudes, has been investigated optically and thermally. The MaReCo is an asymmetrical compound parabolic concentrator with a bi-facial absorber. The collector can be adapted to various installation conditions, for example stand-alone, roof- or wall mounted. MaReCo prototypes ...

  5. Coloured solar collectors. Phase II : from laboratory samples to collector prototypes. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Schueler, A.; Roecker, Ch.; Chambrier, E. de; Munari Probst, M.

    2007-07-01

    This illustrated final report for the Swiss Federal Office of Energy (SFOE) deals with the second phase of a project concerning the architectural integration of glazed solar collectors into the facades of buildings for heat production. The factors that limit the integration of photovoltaic panels in facades are discussed. The authors state that, for a convincing demonstration, sufficiently large samples and high quality levels are needed. The sol-gel deposition of the multi-layered coatings on A4-sized glass panes demonstrated in the laboratory by EPFL-LESO are discussed. The coatings produced exhibit a coloured reflection in combination with a high solar transmittance, a homogenous appearance, and are free of visible defects. Film hardening by UV exposure is discussed: This should result in the speeding up of the sol-gel process and thus save energy, thereby significantly reducing costs. Collaboration with industry is discussed in which full-scale glass panes are to be coated with novel multiple layers. The novel glazing is to be integrated into first prototype collectors. The manufacturing and test processes for the prototypes manufactured are discussed in detail.

  6. Analysis of collector-emitter offset voltage of InGaP/GaAs composite collector double heterojunction bipolar transistor

    Science.gov (United States)

    Lew, K. L.; Yoon, S. F.

    2002-04-01

    The Ebers-Moll-like terminal current expressions of a composite collector double heterojunction bipolar transistor (DHBT), which takes the recombination effect into account, have been formulated and an expression for collector-emitter offset voltage [VCE(offset)] has been derived. Factors affecting the VCE(offset) of a composite collector DHBT are investigated and good agreement between the calculated and reported experimental results is shown. Analytical results showed that the transmission coefficient of the base-collector (B-C) junction does not have a considerable effect on the VCE(offset), provided that the B-C junction is of good quality. Thus, despite its asymmetric structure, the VCE(offset) of an optimally designed composite collector DHBT could be as low as that of a conventional DHBT. Hence a composite collector DHBT with low saturation voltage and negligible VCE(offset) is possible if the two conditions: (i) good quality B-C junction, (ii) base transport factor, α≈1, are fulfilled.

  7. Charge-pump voltage converter

    Science.gov (United States)

    Brainard, John P.; Christenson, Todd R.

    2009-11-03

    A charge-pump voltage converter for converting a low voltage provided by a low-voltage source to a higher voltage. Charge is inductively generated on a transfer rotor electrode during its transit past an inductor stator electrode and subsequently transferred by the rotating rotor to a collector stator electrode for storage or use. Repetition of the charge transfer process leads to a build-up of voltage on a charge-receiving device. Connection of multiple charge-pump voltage converters in series can generate higher voltages, and connection of multiple charge-pump voltage converters in parallel can generate higher currents. Microelectromechanical (MEMS) embodiments of this invention provide a small and compact high-voltage (several hundred V) voltage source starting with a few-V initial voltage source. The microscale size of many embodiments of this invention make it ideally suited for MEMS- and other micro-applications where integration of the voltage or charge source in a small package is highly desirable.

  8. Sampling efficiency of the Moore egg collector

    Science.gov (United States)

    Worthington, Thomas A.; Brewer, Shannon K.; Grabowski, Timothy B.; Mueller, Julia

    2013-01-01

    Quantitative studies focusing on the collection of semibuoyant fish eggs, which are associated with a pelagic broadcast-spawning reproductive strategy, are often conducted to evaluate reproductive success. Many of the fishes in this reproductive guild have suffered significant reductions in range and abundance. However, the efficiency of the sampling gear used to evaluate reproduction is often unknown and renders interpretation of the data from these studies difficult. Our objective was to assess the efficiency of a modified Moore egg collector (MEC) using field and laboratory trials. Gear efficiency was assessed by releasing a known quantity of gellan beads with a specific gravity similar to that of eggs from representatives of this reproductive guild (e.g., the Arkansas River Shiner Notropis girardi) into an outdoor flume and recording recaptures. We also used field trials to determine how discharge and release location influenced gear efficiency given current methodological approaches. The flume trials indicated that gear efficiency ranged between 0.0% and 9.5% (n = 57) in a simple 1.83-m-wide channel and was positively related to discharge. Efficiency in the field trials was lower, ranging between 0.0% and 3.6%, and was negatively related to bead release distance from the MEC and discharge. The flume trials indicated that the gellan beads were not distributed uniformly across the channel, although aggregation was reduced at higher discharges. This clustering of passively drifting particles should be considered when selecting placement sites for an MEC; further, the use of multiple devices may be warranted in channels with multiple areas of concentrated flow.

  9. Advanced Hybrid Particulate Collector Project Management Plan

    Energy Technology Data Exchange (ETDEWEB)

    Miller, S.J.

    1995-11-01

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

  10. Performance of cylindrical plastic solar collectors for air heating

    International Nuclear Information System (INIS)

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

  11. Electrokinetic properties of wavellite and its floatability with cationic and anionic collectors.

    Science.gov (United States)

    Nunes, Aline Pereira Leite; Peres, Antônio Eduardo Clark; de Araujo, Armando Corrêa; Valadão, George Eduardo Sales

    2011-09-15

    The reverse apatite flotation with fatty acids has been widely used for the reduction of phosphorus content of magmatic origin iron ores. However, the occurrence of phosphorus intensely disseminated as secondary minerals such as wavellite renders the anionic reverse flotation a challenge. Zeta potential measurements and microflotation tests of wavellite with the use of anionic and cationic collectors were carried out in this work. The wavellite's IEP value was achieved at pH 4.5. Below the IEP value, the surface positively charged sites are made up of aluminum ions. The species H(+), Al(OH)(2)(+), Al(OH)(2+), Al(3+), OH(-), H(2)PO(4)(-), HPO(4)(2-), and PO(4)(3-) play a role in the protonation and deprotonation reactions that will determine the wavellite-solution interface properties. The highest values of wavellite's floatability under basic pH conditions were achieved in the presence of cationic collectors (1 × 10(-4) mol L(-1)). The formation of surface complexes and the precipitation of insoluble salt of aluminum onto wavellite surface seems to be the most likely hypothesis for the chemical nature interactions between amines and wavellite. The surface formation of aluminum oleate on the wavellite's surface seems to be the most probable hypothesis for the adsorption mechanism and the resultant high floatability of wavellite between pH 7.5 and pH 10.0 in the presence of sodium oleate (1 × 10(-4) mol L(-1)). The results showed that the cationic reverse flotation of secondary phosphates is a promising route to reduce the phosphorus content of iron ores from deposits that underwent a supergene enrichment process, since wavellite floatability in the alkaline pH range, using amine as collector, was not significantly affected by the presence of corn starch. PMID:21719026

  12. Atmospheric Ionic Deposition in Tropical Sites of Central Sulawesi Determined by Ion Exchange Resin Collectors and Bulk Water Collector.

    Science.gov (United States)

    Köhler, S; Jungkunst, H F; Gutzler, C; Herrera, R; Gerold, G

    2012-09-01

    In the light of global change, the necessity to monitor atmospheric depositions that have relevant effects on ecosystems is ever increasing particularly for tropical sites. For this study, atmospheric ionic depositions were measured on tropical Central Sulawesi at remote sites with both a conventional bulk water collector system (BWS collector) and with a passive ion exchange resin collector system (IER collector). The principle of IER collector to fix all ionic depositions, i.e. anions and cations, has certain advantages referring to (1) post-deposition transformation processes, (2) low ionic concentrations and (3) low rainfall and associated particulate inputs, e.g. dust or sand. The ionic concentrations to be measured for BWS collectors may easily fall below detection limits under low deposition conditions which are common for tropical sites of low land use intensity. Additionally, BWS collections are not as independent from the amount of rain fallen as are IER collections. For this study, the significant differences between both collectors found for nearly all measured elements were partly correlated to the rainfall pattern, i.e. for calcium, magnesium, potassium and sodium. However, the significant differences were, in most cases, not highly relevant. More relevant differences between the systems were found for aluminium and nitrate (434-484 %). Almost five times higher values for nitrate clarified the advantage of the IER system particularly for low deposition rate which is one particularity of atmospheric ionic deposition in tropical sites of extensive land use. The monthly resolution of the IER data offers new insights into the temporal distribution of annual ionic depositions. Here, it did not follow the tropical rain pattern of a drier season within generally wet conditions. PMID:22865942

  13. Performance analysis of photovoltaic thermal (PVT) water collectors

    International Nuclear Information System (INIS)

    Highlights: • Performances analysis of PVT collector based on energy efficiencies. • New absorber designs of PVT collectors were presented. • Comparison present study with other absorber collector designs was presented. • High efficiencies were obtained for spiral flow absorber. - Abstract: The electrical and thermal performances of photovoltaic thermal (PVT) water collectors were determined under 500–800 W/m2 solar radiation levels. At each solar radiation level, mass flow rates ranging from 0.011 kg/s to 0.041 kg/s were introduced. The PVT collectors were tested with respect to PV efficiency, thermal efficiency, and a combination of both (PVT efficiency). The results show that the spiral flow absorber exhibited the highest performance at a solar radiation level of 800 W/m2 and mass flow rate of 0.041 kg/s. This absorber produced a PVT efficiency of 68.4%, a PV efficiency of 13.8%, and a thermal efficiency of 54.6%. It also produced a primary-energy saving efficiency ranging from 79% to 91% at a mass flow rate of 0.011–0.041 kg/s

  14. Effect of the collector tube profile on Pitot pump performances

    International Nuclear Information System (INIS)

    The pitot pump is composed of the rotating casing with the impeller channel and the pitot tube type collector as the discharge line. The radial impeller feeds water to the rotating casing. The water rotating together with the casing is caught by the stationary pitot tube type collector, and then discharges to the outside. This type pump, as the extra high head pump, is provided mainly for boiler feed systems, and has been designed by trial and error. To optimize the pump profiles, it is desirable to investigate not only performances but also internal flow conditions. This paper discusses experimentally and numerically the relation between the pump performances and the flow conditions in the rotating casing. The moderately larger dimensions of the collector make the pump head and the discharge high with the higher hydraulic efficiency. The flow in the casing is almost the forced vortex type whose velocity is in proportion to the radius but the core velocity is affected with the drag force of the stationary collector. Based upon the above results, the profile of the pitot tube type collector was optimized with the numerical simulation

  15. Commissioning a Megawatt-class Gyrotron with Collector Potential Depression

    Science.gov (United States)

    Lohr, J.; Cengher, M.; Gorelov, Y. A.; Ponce, D.; Prater, R.

    2013-10-01

    A 110 GHz depressed collector gyrotron has been installed on the DIII-D tokamak. The commissioning process rapidly achieved operation at full parameters, 45 A and 94 kV total voltage, with 29 kV depression. Although short pulse, 2 ms, factory testing demonstrated 1.2 MW at 41% electrical efficiency, long pulse testing at DIII-D achieved only 33% efficiency at full power parameters, for pulse lengths up to 10 s. Maximum generated power was ~950 kW, considerably below the 1.2 MW target. During attempts to increase the power at 5 s pulse length, it was noted that the collector cooling water was boiling. This led to the discovery that 14 of the 160 cooling channels in the collector had been blocked by braze material during manufacture of the tube. The locations of blocked channels were identified using infrared imaging of the outside of the collector during rapid changes in the cooling water temperature. Despite these difficulties, the rf beam itself was of very high quality and the stray rf found calorimetrically in the Matching Optics Unit, which couples the Gaussian rf beam to the waveguide, was only 2% of the generated power, about half that of our previous best quality high power beam. Details of the power measurements and collector observations will be presented. Work supported by the US DOE under DE-FC02-04ER54698.

  16. Experimental Study on the Optical Performance of Evacuated Solar Collectors

    International Nuclear Information System (INIS)

    This work has been carried out to find the ideal operating conditions for solar vacuum tube collectors which are widely used at present. Various types of solar collectors including a flat plate one were experimentally tested and examined to determine their thermal efficiencies and operating characteristics. Generally, solar vacuum tubes can be classified into two groups according to their design features. Of these, one is characterized by the insertion of a metallic device(such as a finned heat pipe) in an evacuated glass tube for the collection and transportation of solar energy. The other utilizes double glass tubes where the smaller one is contained inside the bigger one and soldered to each other after the small gap between them is evacuated. Both of these solar collectors are designed to minimize convection heat losses by removing the air which is in direct contact with the absorber surface. The performance of the former type can be readily analyzed by applying the relevant correlations developed for flat plate solar collectors. This has been demonstrated in the present study for the case of a solar collector where a heat pipe is inserted in an evacuated tube

  17. Planar concentrators for flat-plate solar collectors

    Energy Technology Data Exchange (ETDEWEB)

    Chiam, H.F.

    1981-01-01

    A systematic study has been made of the effectiveness of planar specular reflectors for solar energy collectors. Two daily averaged indices of performance were used. One, the area ratio, indicates the amount by which the reflector extends the effective receiver area. The other is the enhancement factor, which is used to compare the energy received by an augmented collector with that by a reference collector at optimum tilt. A reflector can be mounted either above or below a flat-plate collector. Both combinations are evaluated fully, by varying separately the angular position and dimensions of the reflector and of the collector. The principal parameters are identified and the main characteristics summarised as a series of performance curves. These curves provide an easy method for determining optimum reflector geometries. Use of the performance curves may be extended to obtain the configuration of the two reflectors in a trough concentrator. This also allows the single-reflector system to be compared directly with the trough concentrator. Evidence is presented which shows the advantages of an asymmetrical trough configuration over a symmetrical concentrator.

  18. Development of a Small Modular Parabolic trough Collector

    Energy Technology Data Exchange (ETDEWEB)

    Hoffschmidt, B.; Schwarzer, K.; Spate, F.; Kotter, J.; Ebert, M.; Sierck, O.

    2006-07-01

    A small parabolic trough collector is developed with the purpose to achieve a high efficiency at temperatures up to 300 degree Celsius. The collector has an aperture area of 1 m width and 2 m length. Therefore it can be used very easily for roof installations. Tests at the collector test stand of the Solar-Institut Juelich show good results up to 100 degree celsius. The power is about 1 kW. The collector's efficiency is above 50%. Stagnation experiments have shown temperatures around 590 degree celsius at a direct radiation of 730 W/square meters and 7 degree Celsius ambient temperature. The collector consists of a form giving rib construction of stainless steel covered with an aluminum reflector with a reflection coefficient of 95%. A standard vacuum tube (Sidney-principle) 200 cm long is used as absorber. Anti Reflex Glass with a solar transmission of more than 95% is used as cover. The tracking system is consisting of a stepper motor, transmission, sun sensor and electronic steering. (Author)

  19. MERCURY CONTROL WITH ADVANCED HYBRID PARTICULATE COLLECTOR

    Energy Technology Data Exchange (ETDEWEB)

    Ye Zhuang; Stanley J. Miller

    2005-05-01

    This project was awarded under U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) Program Solicitation DE-PS26-00NT40769 and specifically addressed Technical Topical Area 4-Testing Novel and Less Mature Control Technologies on Actual Flue Gas at the Pilot Scale. The project team included the Energy & Environmental Research Center (EERC) as the main contractor; W.L. Gore & Associates, Inc., as a technical and financial partner; and the Big Stone Power Plant operated by Otter Tail Power Company, host for the field-testing portion of the research. Since 1995, DOE has supported development of a new concept in particulate control called the advanced hybrid particulate collector (AHPC). The AHPC has been licensed to W.L. Gore & Associates, Inc., and has been marketed as the Advanced Hybrid{trademark} filter by Gore. The Advanced Hybrid{trademark} filter combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The Advanced Hybrid{trademark} filter provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and it solves the problem of reentrainment and re-collection of dust in conventional baghouses. The Advanced Hybrid{trademark} filter also appears to have unique advantages for mercury control over baghouses or ESPs as an excellent gas--solid contactor. The objective of the project was to demonstrate 90% total mercury control in the Advanced Hybrid{trademark} filter at a lower cost than current mercury control estimates. The approach included bench-scale batch tests, larger-scale pilot testing with real flue gas on a coal-fired combustion system, and field demonstration at the 2.5-MW (9000-acfm) scale at a utility power plant to prove scale-up and demonstrate longer-term mercury control

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

    DEFF Research Database (Denmark)

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

    2004-01-01

    and large solar heating systems. Based on the theoretical findings a prototype of an improved HT solar collector was built and tested side-by-side with the original HT solar collector. The improved HT collector makes use of a changed insulation material, an absorber with improved absorptance and......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...

  1. Fast separation of isobars on ISOL facility collector

    International Nuclear Information System (INIS)

    Volatility of Rb, Sr, Y, Ba, some rare earth elements, Ra, Ac and Th, implantated in a tantalum collector with 45 keV energy is investigated. The collector heating during 180 s in vacuum results in the separation of implantated elements. Separation coefficients are as follows: sup(α)Sr/Rb=14/1390 K/, sup(α)Y/Sr=28/1680 K/, sup(α)La/Ba=8/1590 K/, sup(α)Sm/Eu=3/1470 K/, sup(α)Gd/Eu=22/1620 K/, sup(α)Tm/Yb=8/1600 K/, sup(α)Lu/Yb=38/1700 K/ and sup(α)Ac/Ra=sup(α)Th/Ra=030/1650 K/. The contributions of diffusion and desorption to the volatility process of implantated elements and prospects for application of the proposed method for separation of isobars on ISOL Facility collector are discussed

  2. Absorber Alignment Measurement Tool for Solar Parabolic Trough Collectors: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Stynes, J. K.; Ihas, B.

    2012-04-01

    As we pursue efforts to lower the capital and installation costs of parabolic trough solar collectors, it is essential to maintain high optical performance. While there are many optical tools available to measure the reflector slope errors of parabolic trough solar collectors, there are few tools to measure the absorber alignment. A new method is presented here to measure the absorber alignment in two dimensions to within 0.5 cm. The absorber alignment is measured using a digital camera and four photogrammetric targets. Physical contact with the receiver absorber or glass is not necessary. The alignment of the absorber is measured along its full length so that sagging of the absorber can be quantified with this technique. The resulting absorber alignment measurement provides critical information required to accurately determine the intercept factor of a collector.

  3. Wind effects in solar fields with various collector designs

    Science.gov (United States)

    Paetzold, Joachim; Cochard, Steve; Fletcher, David F.; Vassallo, Anthony

    2016-05-01

    Parabolic trough power plants are often located in areas that are subjected to high wind speeds, as an open terrain without any obstructions is beneficial for the plant performance. The wind impacts both the structural requirements and the performance of the plant. The aerodynamic loads from the wind impose strong requirements on the support structure of the reflectors, and they also impact the tracking accuracy. On a thermal level the airflow around the glass envelope of the receiver tube cools its outer surface through forced convection, thereby contributing to the heat loss. Based on previous studies at the level of an individual row of collectors, this study analyses the wind effects in a full-scale solar field of different continuous and staggered trough designs. The airflow around several rows of parabolic trough collectors (PTC) is simulated at full scale in steady state simulations in an atmospheric boundary layer flow using the commercial computational fluid dynamics software ANSYSO® CFX 15.0. The effect of the wake of a collector row on the following collectors is analysed, and the aerodynamic loads are compared between the different geometries. The outermost collectors of a solar field experience the highest wind forces, as the rows in the interior of the solar field are protected from high wind speeds. While the aerodynamic forces in the interior of the solar field are almost independent of the collector shape, the deeper troughs (with large rim angles) tested in this study show a lower heat loss due to forced convection on the outer surface of the receiver tube than the shallower ones (with small rim angles) in most of the solar field.

  4. Liquid metal current collectors for high-speed rotating machinery

    International Nuclear Information System (INIS)

    Recent interest in superconducting motors and generators has created a renewed interest in homopolar machinery. Homopolar machine designs have always been limited by the need for compact, high-current, low-voltage, sliding electrical curent collectors. Conventional graphite-based solid brushes are inadequate for use in homopolar machines. Liquid metals, under certain conditions of relative sliding velocities, electrical currents, and magnetic fields are known to be capable of performing well in homopolar machines. An effort to explore the capabilities and limits of a tongue-and-groove style current collector, utilizing sodium-potassium eutectic alloy (NaK) as the working fluid in high sliding speed operation is reported here. A double current collector generator model with a 14.5-cm maximum rotor diameter, 20,000 rpm rotational capability, and electrical current carrying ability was constructed and operated successfully at a peripheral velocity of 125 m/s. The limiting factor in these experiments was a high-speed fluid-flow instability resulting in the ejection of the working fluid from the operating portions of the collectors. The effects of collector size and geometry, working fluid (NaK or water), and cover gas pressure are reported. Hydrodynamic frictional torque-speed curves are given for the two fluids and for several geometries. Electrical resistances as a function of peripheral velocity at 60 amperes are reported, and the phenomenology of the high-speed fluid-flow instabilities is discussed. The possibility of long-term high-speed operation of current collectors of the tongue-and-groove type, along with experimental and theoretical hydrodynamic friction losses at high peripheral velocities, is considered

  5. To Spark a Revolution - New Developments in Multiple Collector ICPMS

    Science.gov (United States)

    Halliday, A. N.

    2002-12-01

    Multiple-collector ICPMS represents the biggest development in precise isotope ratio mass spectrometry of the past decade and has had a huge effect on cosmochemistry and geochemistry. Dan Weill played a critical role in this, demonstrating his ability to take risks to support innovation and acquire the world's first such instrument. The most important benefit has been that major areas of the periodic table have become accessible to high precision isotopic measurements on the relatively small sample sizes required when studying many natural systems. In cosmochemistry the biggest advances so far have been in W, Mo, Te and Zr measurements, permitting the exploration of new radioactive decay systems and nucleosynthetic isotopic effects. Hf-W cosmochemistry in particular has provided very powerful new constraints on the rates of formation of the terrestrial planets and asteroids. However, the expansion of the field of stable isotopes into high precision Mg, Ti, Cr, Fe, Cu, Zn, Mo, Cd, Tl and even U isotope measurements also offers a great deal of potential for fruitful discoveries. At this stage the magnitude and mechanisms of these fractionations are still being characterized and understood. The measurements themselves can be prone to artifacts. However, there is no question that large fractionations in Fe isotopic composition accompany certain oxidation - reduction reactions and some biological processes even though the exact mechanisms are often unclear. As the techniques have improved it has become possible to resolve incredibly small (100 ppm) fractionations in isotopic composition associated with high temperature processes and these are providing new insights into planetary and igneous processes. MC-ICPMS also has permitted more precise measurements of U series nuclides allowing us to trace sea-level changes further back in time. The use of in situ laser ablation measurements still has scarcely been explored. The world's first large geometry MC-ICPMS instrument

  6. Tracking local control of a parabolic trough collector

    International Nuclear Information System (INIS)

    In the local control, the sun position related to the trough collector is measured by two photo-resistors. The provided electronic signal is then compared with reference levels in order to get a set of B logical signals which form a byte. This byte and the commands issued by a programmable controller are connected to the inputs of o P.R.O.M. memory which is programmed with the logical equations of the control system. The memory output lines give the control command of the parabolic trough collector motor. (Author)

  7. Current collector geometry and mixing in liquid metal electrodes

    Science.gov (United States)

    Ashour, Rakan; Kelley, Douglas

    2015-11-01

    Liquid metal batteries are emerging as an efficient and cost effective technology for large-scale energy storage on electrical grids. In these batteries, critical performance related factors such as the limiting current density and life cycle are strongly influenced by fluid mixing and transport of electrochemical species to and from the electrode-electrolyte interface. In this work, ultrasound velocimetry is used to investigate the role of negative current collector location on the induced velocity, flow pattern, and mixing time in liquid metal electrodes. Ultrasound velocity measurements are obtained at a range of operating current densities. Furthermore, a comparison between velocity profiles produced by current collectors with different sizes is also presented.

  8. On the Adsorption of Some Anionic Collectors on Fluoride Minerals

    DEFF Research Database (Denmark)

    Sørensen, Emil

    1973-01-01

    Test flotations have been carried out in a small apparatus under standardized conditions in order to determine the dependence of the flotation yield on the reagent concentration for certain minerals and anionic collectors. The results suggest that a special adsorption mechanism is operating in th...... case of fluoride minerals, and a theory is presented which involves the joint action of ionic and hydrogen bonds. A precondition is the compatibility of the crystal geometry with the configuration of the polar group of the collector molecules....

  9. Opensource Software for MLR-Modelling of Solar Collectors

    DEFF Research Database (Denmark)

    Bacher, Peder; Perers, Bengt

    2011-01-01

    A first research version is now in operation of a software package for multiple linear regression (MLR) modeling and analysis of solar collectors according to ideas originating all the way from Walletun et. al. (1986), Perers, (1987 and 1993). The tool has been implemented in the free and open...... source program R http://www.r-project.org/. Applications of the software package includes: visual validation, resampling and conversion of data, collector performance testing analysis according to the European Standard EN 12975 (Fischer et al., 2004), statistical validation of results...

  10. Collector optimization for tradeoff between breakdown voltage and cut-off frequency in SiGe HBT

    International Nuclear Information System (INIS)

    As is well known, there exists a tradeoff between the breakdown voltage BVCEO and the cut-off frequency fT for a standard heterojunction bipolar transistor (HBT). In this paper, this tradeoff is alleviated by collector doping engineering in the SiGe HBT by utilizing a novel composite of P+ and N− doping layers inside the collector-base (CB) space-charge region (SCR). Compared with the single N-type collector, the introduction of the thin P+ layers provides a reverse electric field weakening the electric field near the CB metallurgical junction without changing the field direction, and the thin N− layer further effectively lowers the electric field near the CB metallurgical junction. As a result, the electron temperature near the CB metallurgical junction is lowered, consequently suppressing the impact ionization, thus BVCEO is improved with a slight degradation in fT. The results show that the product of fT × BVCEO is improved from 309.51 GHz·V to 326.35 GHz·V. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  11. Possibility of using strain F9 ( Serratia marcescens) as a bio-collector for hematite flotation

    Science.gov (United States)

    Yang, Hui-fen; Li, Tian; Chang, Yan-hong; Luo, Hui; Tang, Qiong-yao

    2014-03-01

    In this study, we characterized strain F9 and evaluated the interaction between strain F9 and hematite by scanning electron microscopy (SEM), Fourier transform infrared spectrophotometry (FTIR), zeta potential, flotation, and other methods. The results showed that strain F9 belongs to Serratia marcescens. This brevibacterium had CH2, CH3, and hydroxyl groups on its cell wall, which imparted a strong hydrophobic and negative charge. Adsorption of strain F9 reduced the zeta potential of the hematite surface and increased the hydrophobicity of the hematite surface, thereby generating hydrophobic hematite agglomerates. At least four groups on strain F9 interacted with the hematite surface, which contributed to chemical interactions of carboxylic groups and hydrophobic association among hydrophobic hematite particles. The possible use of strain F9 as a bio-collector for hematite flotation was proved.

  12. VALIDATION OF SIMULATION MODELS FOR DIFFERENTLY DESIGNED HEAT-PIPE EVACUATED TUBULAR COLLECTORS

    DEFF Research Database (Denmark)

    Fan, Jianhua; Dragsted, Janne; Furbo, Simon

    2007-01-01

    Differently designed heat-pipe evacuated tubular collectors have been investigated theoretically and experimentally. The theoretical work has included development of two TRNSYS [1] simulation models for heat-pipe evacuated tubular collectors utilizing solar radiation from all directions. One model...... is developed for heat-pipe evacuated tubular collectors with flat fins and one model is developed for heat-pipe evacuated tubular collectors with curved fins. The models are characterized by detailed calculations of the heat transfer processes in the fins, by detailed shadow modeling and by fins with...... selective coating on both sides. The input to the models is thus not a simple collector efficiency expression but the actual collector geometry. In this study, the TRNSYS models are validated with measurements for four differently designed heat-pipe evacuated tubular collectors. The collectors are produced...

  13. The Effect of the Volume Flow rate on the Efficiency of a Solar Collector

    DEFF Research Database (Denmark)

    Fan, Jianhua; Shah, Louise Jivan; Furbo, Simon

    rates. Theoretically, a simplified model of the solar collector panel is built by means of the CFD (Computational Fluid Dynamics) code Fluent, where the geometry of the collector panel except the casing is fully modeled. Both lateral and longitudinal heat conduction in the absorber fins, the heat...... transfer from the absorber to the solar collector fluid and the heat loss from the absorber are considered. Flow and temperature distribution in the collector panel are investigated with buoyancy effect. Measurements are carried out with the solar collector panel. Collector efficiencies are measured for......The flow distribution inside a collector panel with an area of 12.5 m² and with 16 parallel connected horizontal fins and the effect of the flow nonuniformity on the risk of boiling and on the collector efficiency have been theoretically and experimentally investigated for different volume flow...

  14. FLOW DISTRIBUTION IN A SOLAR COLLECTOR PANEL WITH HORIZONTAL ABSORBER STRIPS

    DEFF Research Database (Denmark)

    Fan, Jianhua; Shah, Louise Jivan; Furbo, Simon

    2007-01-01

    The objective of this work is to theoretically and experimentally investigate the flow and temperature distribution in a solar collector panel with an absorber consisting of horizontal strips. Fluid flow and heat transfer in the collector panel are studied by means of computational fluid dynamics...... (CFD) calculations. Further, experimental investigations of a 12.5 m² solar collector panel with 16 parallel connected horizontal fins are carried out. The flow distribution through the absorber is evaluated by means of temperature measurements on the backside of the absorber tubes. The measured...... collector fluid, and by increased collector tilt and inlet temperature, the flow distribution gets worse resulting in a decreased collector efficiency and an increased risk of boiling in the upper part of the collector panel. Keywords: Solar collector; Flow distribution; Computational Fluid Dynamics (CFD...

  15. VALIDATION OF SIMULATION MODELS FOR DIFFERENTLY DESIGNED HEAT-PIPE EVACUATED TUBULAR COLLECTORS

    DEFF Research Database (Denmark)

    Fan, Jianhua; Dragsted, Janne; Furbo, Simon

    Differently designed heat-pipe evacuated tubular collectors have been investigated theoretically and experimentally. The theoretical work has included development of two TRNSYS [1] simulation models for heat-pipe evacuated tubular collectors utilizing solar radiation from all directions. One model...... is developed for heat-pipe evacuated tubular collectors with flat fins and one model is developed for heat-pipe evacuated tubular collectors with curved fins. The models are characterized by detailed calculations of the heat transfer processes in the fins, by detailed shadow modeling and by fins with...... selective coating on both sides. The input to the models is thus not a simple collector efficiency expression but the actual collector geometry. In this study, the TRNSYS models are validated with measurements for four differently designed heat-pipe evacuated tubular collectors. The collectors are produced...

  16. Design and development of high efficiency 140W space TWT with graphite collector

    International Nuclear Information System (INIS)

    4-stage graphite collector assembly has been designed and developed for a 140W Ku-band space TWT to achieve the collector efficiency more than 80%. The UHV compatible, high density, copper impregnated POCO graphite (DFP-1C) was used to fabricate the four collector electrodes of the 4-stage depressed collector. Copper impregnated graphite material is used for the collector electrodes because of its low secondary electron emission coefficient, high thermal and electrical conductivities, easy machining and brazing, low thermal expansion coefficient and low weight. The graphite material was characterized for the UHV compatibility. The collector electrodes were precisely fabricated by careful machining, and technology was developed for brazing of graphite electrodes with high voltage alumina insulators. Complete TWT with four-stage graphite collector was developed and 140W output power at gain more than 55 dB was achieved. The TWT was pumped from both the gun and the collector ends

  17. 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

    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....... 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, the...

  18. Computer simulation of flaring the heat-exchange tube in the collectors of steam generators

    International Nuclear Information System (INIS)

    It is considered aspects of the WWER-1000 power reactor heat generator collector deformation processes modeling, which are taken place at heat generator assembling during heat collector tubes fastening by means of explosive method. It is presented description of the numerical solution method of geometrically nonlinear task of the collector and heat exchange tubes elasticity-plasticity deformation. It is considered the calculation examples of strain-stress conditions appearing in the collectors at heat generator manufacturing

  19. Thermal and Electrical Performance Evaluation of PV/T Collectors in UAE

    OpenAIRE

    Kaya, Mustafa

    2013-01-01

    Photovoltaic Thermal/Hybrid collectors are an emerging technology that combines PV and solar thermal collectors by producing heat and electricity simultaneously. In this paper, thermal and electrical performance of PV/T collectors are analyzed and presented for the climate of RAK, UAE. Thermal performance evaluation is done following the collector output model presented in European standard EN 12975-2 and electrical performance evaluation is done by analyzing the effect of water circulation o...

  20. Status of concentrator collector and high-efficiency concentrator cell development

    Energy Technology Data Exchange (ETDEWEB)

    Gee, J.M.

    1990-01-01

    Photovoltaic concentrator collectors are an attractive option for utility-scale photovoltaic power plants. This paper reviews the current status of photovoltaic concentrator collector and cell development. Included in the review is a discussion of the economic motivation for concentrators, a summary of recent concentrator collector and cell development, and a description of a major new program to accelerate development and commercial introduction of concentrator collectors. 21 refs., 1 fig., 3 tabs.

  1. Development of movable faraday cup for precise charge measurement

    International Nuclear Information System (INIS)

    The high brightness electron beam is required for the 8-GeV linac in SACLA in order to generate an x-ray free electron laser. The high peak current beam is generated by bunch compressors, which shorten a bunch length up to several tens of femto-seconds. The precise charge measurement of the bunched beam is indispensable for estimation of the peak current, which is important to determine the characteristics of the x-ray free-electron laser, such as a FEL gain length. The longitudinal charge distribution of the bunched beam is measured by an rf deflector. Simultaneously, the total beam charge is measured by using a current transformer (CT), which is a non-destructive beam current monitor. By using both the distribution and total charge, we can estimate the peak current value. To calibrate the current monitor, we had installed a Faraday cup, which was designed to achieve a resolution of less than 1 pC. The geometry of a collector in the Faraday cup was determined by estimations of energy loss, charge loss and thermal analyses. The collector is designed to be retractable with an actuator, in order that the beam for the user experiment is supplied without intercepting beam transport. To reduce the charge loss due to secondary emission in the collector, a bias voltage can be applied between the collector and a vacuum chamber. In order to check the performance of the Faraday cup, the beam test was carried out. An absolute accuracy of beam charge measurement of the single bunch beam with a bunch length of 20 fs or less was achieved ±2% by using the Faraday cup. The CT was calibrated with sufficient accuracy. (author)

  2. Upper airway inflammation and respiratory symptoms in domestic waste collectors

    OpenAIRE

    Wouters, I; Hilhorst, S; Kleppe, P; Doekes, G; Douwes, J; Peretz, C; Heederik, D.

    2002-01-01

    Objectives: To compare respiratory symptoms and upper airway inflammation in domestic waste collectors and controls, and to find the association between measures of upper airway inflammation on the one hand and exposure concentrations of organic dust or respiratory symptoms on the other hand.

  3. EuroTrough collector prototype under testing at PSA

    Energy Technology Data Exchange (ETDEWEB)

    Luepfert, E.; Geyer, M. [German Aerospace Center (DLR), Platforma Solar de Almeria (PSA) (Spain); Schiel, W. [Schlaich Bergermann und Partner (SBP), Stuttgart (Germany); Esteban, A.; Osuna, R. [INABENSA, Div. Taller, Sevilla (Spain); Zarza, E.; Rojas, E. [CIEMAT-PSA, Plataforma Solar de Almeria (Spain); Nava, P. [Flabeg Solar International, Cologne (Germany); Brakmann, G. [Fichtner Solar, Stuttgart (Germany); Kotsaki, E. [CRES, Athens (Greece)

    2001-07-01

    In international project collaboration a parabolic trough collector has been developed for various applications in the 200-400 C temperature range in solar fields up to the hundreds Megawatts range. The design of a new support structure of the collector included concept studies, wind tunnel measurements, finite elements method (FEM) analyses and resulted in a structure with a central framework element. This torque box design has lower weight and less deformation of the collector structure than the other designs considered. It will be possible in future to connect more collector elements on one drive which results in reduced total number of drives and interconnecting pipes, thus reducing the installation cost and thermal losses. In terms of the degree of material usage further weight reduction will be possible. The presented design has a significant potential for cost reduction, the most important goal of the EuroTrough project. The prototype has been set-up and is under testing at PSA (Plataforma Solar de Almeria) for its thermal and mechanical properties. (orig.)

  4. Solar Thermal Power Plants with Parabolic-Trough Collectors

    Science.gov (United States)

    Zarza, E.; Valenzuela, L.; León, J.

    2004-12-01

    Parabolic-trough collectors (PTC) are solar concentrating devices suitable to work in the 150°C- 400°C temperature range. Power plants based on this type of solar collectors are a very efficient way to produce electricity with solar energy. At present, there are eight commercial solar plants (called SEGS-II, III,.. IX) producing electricity with parabolic-trough collectors and their total output power is 340 MW. Though all SEGS plants currently in operation use thermal oil as a heat transfer fluid between the solar field and the power block, direct steam generation (DSG) in the receiver tubes is a promising option to reduce the cost of electricity produced with parabolic- trough power plants. Most of technical uncertainties associated to the DSG technology were studied and solved in the DISS project and it is expected that this new technology will be commercially available in a short term. In Spain, the Royal Decree No. 436/204 (March 12th , 2004) has defined a premium of 0,18€/kWh for the electricity produced by solar thermal power plants, thus promoting the installation of solar thermal power plants up to a limit of 200 MW. Due to the current legal and financial framework defined in Spain, several projects to install commercial solar power plants with parabolic-trough collectors are currently underway.

  5. EUV near normal incidence collector development at SAGEM

    Science.gov (United States)

    Mercier Ythier, R.; Bozec, X.; Geyl, R.; Rinchet, A.; Hecquet, Christophe; Ravet-Krill, Marie-Françoise; Delmotte, Franck; Sassolas, Benoît; Flaminio, Raffaele; Mackowski, Jean-Marie; Michel, Christophe; Montorio, Jean-Luc; Morgado, Nazario; Pinard, Laurent; Roméo, Elodie

    2008-03-01

    Through its participation to European programs, SAGEM has worked on the design and manufacturing of normal incidence collectors for EUV sources. By opposition to grazing incidence, normal incidence collectors are expected to collect more light with a simpler and cheaper design. Designs are presented for the two current types of existing sources: Discharge Produced Plasma (DPP) and Laser Produced Plasma (LPP). Collection efficiency is calculated in both cases. It is shown that these collectors can achieve about 10 % efficiency for DPP sources and 40 % for LPP sources. SAGEM works on the collectors manufacturability are also presented, including polishing, coating and cooling. The feasibility of polishing has been demonstrated with a roughness better than 2 angstroms obtained on several materials (glass, silicon, Silicon Carbide, metals...). SAGEM is currently working with the Institut d'Optique and the Laboratoire des Materiaux Avancés on the design and the process of EUV coatings for large mirrors. Lastly, SAGEM has studied the design and feasibility of an efficient thermal control, based on a liquid cooling through slim channels machined close to the optical surface.

  6. NUMERICAL STUDY ON MIXED CONVECTIVE FLOW IN A SOLAR COLLECTOR

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In a solar energy heat collector forced convection and free convection will occur concurrently. In this paper, the mixed convective flow was investigated. The dimensionless equation was derived and the results was verified by experiments. The numerical solution shows that error is less than 5% if the effect of free convection is ignored.

  7. Silicon crystal as a low work function collector

    Science.gov (United States)

    Chang, K. H.; Shimada, K.

    1975-01-01

    A test vehicle with a low work function collector which can be incorporated in a thermionic converter was constructed from standard vacuum components including an ultrahigh vacuum ion pump. The collector assembly was fabricated by diffusion bonding a (100) oriented silicon single crystal to a molybdenum block. The silicon surface was treated with cesium and oxygen to produce an NEA-type condition and the results were tested by photoemission and work function measurements. An n-type silicon collector was successfully activated to a work function of 1.0 eV, which was verified by photoemission spectral yield measurements. The stability test of an activated surface at elevated temperatures was conducted in the range from room temperature to 619 K, which was slightly lower than the designed collector temperature of 700 K. The work function measurements clearly demonstrated that the behavior of cesium replenishment on the activated Si surface was similar in nature to that of a metallic surface; that is, the loss of cesium by thermal desorption could be compensated by maintaining an adequate vapor pressure of cesium.

  8. Design of a fraction collector for capillary array electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Minarik, M.; Klepárník, Karel; Gilar, M.; Foret, František; Miller, A. W.; Sosic, Z.; Karger, B. L.

    2002-01-01

    Roč. 23, č. 1 (2002), s. 35-42. ISSN 0173-0835 R&D Projects: GA ČR GA203/00/0772 Institutional research plan: CEZ:AV0Z4031919 Keywords : fraction collector * capillary array electrophoresis * DNA analysis Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.325, year: 2002

  9. 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.

  10. HERION equipment controls the testing of solar collectors

    Energy Technology Data Exchange (ETDEWEB)

    Boeck, H.

    1978-01-01

    A comparative test of solar collectors at the University of Munich is reported. The test bench comprises the total radiation detector, the global radiation detector, and the HERION valves to control the supply loop. Reliable values were obtained by steady-state measurement. Evaluation will be made by a large computer.

  11. Theoretical study of honeycomb structure collector for space heating

    Energy Technology Data Exchange (ETDEWEB)

    Ho, L.J.; Daguenet, M.; LePalec, G.

    1984-01-01

    The authors study a honeycomb structure collector which can be used for space heating by passive solar system. The mathematical model gives the temperature distribution and the efficiency as functions of all the parameters and specially the geometrical parameters. The results show that it is possible to obtain good performances with such a system.

  12. Solar-collector manufacturing activity, July through December, 1981

    Energy Technology Data Exchange (ETDEWEB)

    None

    1982-03-01

    Solar thermal collector and solar cell manufacturing activity is both summarized and tabulated. Data are compared for three survey periods (July through December, 1981; January through June, 1981; and July through December, 1980). Annual totals are also provided for the years 1979 through 1981. Data include total producer shipments, end use, market sector, imports and exports. (LEW)

  13. Preliminary design package for Sunair SEC-601 solar collector

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-01

    This report presents the preliminary design of the Owens-Illinois mode Sunair SEC-601 tubular air solar collector. Information in this package includes the Subsystem Design and Development Approaches, hazard analysis, and detailed drawings available as the Preliminary Design Review.

  14. Thermo-ecological optimization of a solar collector

    International Nuclear Information System (INIS)

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

  15. Development, testing, and certification of Life Sciences Engineering solar collector. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Caudle, J. M.

    1978-07-01

    Final results for the development of an air flat plate collector for use with solar heating, combined heating and cooling, and hot water systems are summarized. The contract was for final development, testing, and certification of the collector, and for delivery of a 320 ft/sup 2/ collector panel.

  16. Experimental investigation on performance comparison of nanofluid-based direct absorption and flat plate solar collectors

    Directory of Open Access Journals (Sweden)

    Sh. Delfani

    2015-11-01

    Full Text Available In the present work, a prototype of a new type of solar collectors, which called Direct Absorption Solar Collector, was built and its thermal performance is experimentally compared with conventional flat plate solar collector under transient and steady state conditions. Different volume fractions of multi wall carbon nanotubes in water and ethylene glycol mixture (70%:30% in volume were used as working fluid of direct absorption solar collector.The transient comparison show that the efficiency of the direct absorption solar collector becomes about 7% (in average more than that of flat plate solar collector at 72l/hr flowrate. Thesteady state performance tests were performed in different flowrates from 54to 90l/hr,based on the procedure of EN 12975-2 standard.Under similar operating conditions, adirect absorption solar collector using 100ppm carbon nanotube nanofluid has the zero-loss efficiency of 23% higher than that of a flat plate collector;whereas, the zero-loss efficiency of a direct absorption solar collector using the base fluid is 4.4% lower than that of a flat plate collector. Based onthe results, the performance of a direct absorption solar collector using carbon nanotube nanofluidsis better than a flat-plate solar collector.

  17. Design and installation package for the Sunmat Flat Plate Solar Collector

    Energy Technology Data Exchange (ETDEWEB)

    1978-03-01

    The information used in evaluating the design of the Sunmat Liquid Flat Plat Plate Solar Collector developed by Calmac Manufacturing Company is presented. Included in this package are the Subsystem Performance Specification, Installation, Operation and Maintenance Manuals, collector sizing guides, and detailed drawings of the single-glazed collector.

  18. Design and installation package for the Sunmat Flat Plate solar collector

    Science.gov (United States)

    1978-01-01

    The information used in evaluating the design of a liquid flat plate solar collector is reported. Included in this package are subsystem performance specification, installation, operation and maintenance manuals, collector sizing guides, and detailed drawings of the single-glazed collector.

  19. An investigation of the temperature characteristics of solar collectors with vacuum glass tubes

    Energy Technology Data Exchange (ETDEWEB)

    Li, H.M.; Han, J.

    1982-01-01

    Tests are run on solar collectors in accordance with the ASHPAE 93-77 standard. It is proposed that several changes be incorporated into the test conditions and that their number be limited. The derived results demonstrate that the test standards on flat collectors may also be used for collectors manufactured from vacuum glass tubes.

  20. Fractional charges

    International Nuclear Information System (INIS)

    20 years ago fractional charges were imagined to explain values of conductivity in some materials. Recent experiments have proved the existence of charges whose value is the third of the electron charge. This article presents the experimental facts that have led theorists to predict the existence of fractional charges from the motion of quasi-particles in a linear chain of poly-acetylene to the quantum Hall effect. According to the latest theories, fractional charges are neither bosons nor fermions but anyons, they are submitted to an exclusive principle that is less stringent than that for fermions. (A.C.)

  1. Performance evaluation of two black nickel and two black chrome solar collectors

    Science.gov (United States)

    Losey, R.

    1977-01-01

    The test program was based on the evaluation of four unique solar collectors described below: (1) black nickel collector surface with a desiccant drying bed, (2) black nickel collector surface without a desiccant drying bed, (3) black chrome collector surface with a dessicant drying bed, and (4) black chrome collector surface without a desiccant drying bed. The test program included three distinct phases: Initial performance evaluation, natural environmental aging, and post-aging performance evaluation. Results of Phase III testing conclusively indicated a higher normalized efficiency for Black Chrome surfaces when compared to Black Nickel.

  2. Optimization of plane plate solar collectors; Otimizacao de coletores solares de placas planas

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, D.G.; Fico Junior, Nide G.C.R. [Centro Tecnico Aeroespacial, Sao Jose dos Campos, SP (Brazil). Inst. Tecnologico de Aeronautica. Div. de Engenharia Aeronautica]. E-mail: nide@aer.ita.cta.br

    2000-07-01

    This work presents a study on the theoretical optimization of the plane plates solar energy collectors performance with the introduction of a step-change on the plate fin profile, resulting in the material economy. A theoretical study of the optimization on the ratio cost factor/efficiency factor of the solar energy collector with four materials, with different plate thickness, used for the fin construction, as follows: copper, aluminium, steel and galvanized steel, as function of the distance among the tube centers. Based on the specifications of the materials and collector dimensions, a second optimization were performed taking into account the ratio cost/collector efficiency resulting from the ste-change introduction related to the collector localization. A collector with optimized dimensions was constructed, and efficiency tests performed in accordance with ASHRAE norm, specific for solar energy collectors. (author)

  3. Comparative test of two large solar collectors for solar field application

    DEFF Research Database (Denmark)

    Bava, Federico; Furbo, Simon

    2014-01-01

    order to decrease convection losses. The efficiencies of the collectors were tested for different flow rates and tilt angles. The effect of the change from laminar to turbulent regime was investigated as well. Numerical models of the two collectors were developed with the software Soleff and their......Two large solar collectors for solar heating plants were tested according to the standard norm EN 12975-2. The two collectors were almost identical, the only difference being a thin FEP (fluorinated ethylene propylene) foil interposed between the absorber and the glass cover in one of them, in....... Additionally, the collector efficiency of both collectors increased at higher flow rates and tilt angles. The models developed in Soleff fit the experimental results with an average error of 1% in case of fully laminar and turbulent flow, so that they are likely to be suitable to simulate the collector...

  4. Research and Development of a Low Cost Solar Collector

    Energy Technology Data Exchange (ETDEWEB)

    Ansari, Asif; Philip, Lee; Thouppuarachchi, Chirath

    2012-08-01

    This is a Final Technical Report on the Research and Development completed towards the development of a Low Cost Solar Collector conducted under the DOE cost-sharing award EE-0003591. The objective of this project was to develop a new class of solar concentrators with geometries and manufacturability that could significantly reduce the fully installed cost of the solar collector field for concentrated solar thermal power plants. The goal of the project was to achieve an aggressive cost target of $170/m2, a reduction of up to 50% in the total installed cost of a solar collector field as measured against the current industry benchmark of a conventional parabolic trough. The project plan, and the detailed activities conducted under the scope of the DOE Award project addressed all major drivers that affect solar collector costs. In addition to costs, the study also focused on evaluating technical performance of new collector architectures and compared them to the performance of the industry benchmark parabolic trough. The most notable accomplishment of this DOE award was the delivery of a full-scale integrated design, manufacturing and field installation solution for a new class of solar collector architecture which has been classified as the Bi-Planar Fresnel Collector (BPFC) and may be considered as a viable alternative to the conventional parabolic trough, as well as the conventional Fresnel collectors. This was in part accomplished through the design and development, all the way through fabrication and test validation of a new class of Linear Planar Fresnel Collector architecture. This architecture offers a number of key differentiating features which include a planar light-weight frame geometry with small mass-manufacturable elements utilizing flat mirror sections. The designs shows significant promise in reducing the material costs, fabrication costs, shipping costs, and on-site field installation costs compared to the benchmark parabolic trough, as well as the

  5. Evaluation of tube to collector connection by hydraulic expansion method in PGV-1000 steam generators

    International Nuclear Information System (INIS)

    Research highlights: → The produced residual stresses in the collector body due to hydraulic expansion method have been compared with explosive method. → The residual stresses were obtained using two methods of FEM and strain gauging tests. → The effect of clearance between tube and collector on the residual stresses was investigated. → The contact stresses between the tube and collector interface were modeled and the required connection strength between tube and collector is estimated based on ASME rules and compared with FE results. - Abstract: Investigations on steam generators failure due to cracking in collector ligaments at perforated parts determined that connection process of the tubes to collector could be one of the main breakdown causes. The stability and strength of tube to collector joint is dependent to the geometry of tube and collector, the joining process and the operational conditions. In this research hydraulic expansion method has been considered as connection method of tube to collector. The Finite Element Method (FEM) was used to simulate the hydraulic expansion process and determine stress condition of the joints. The contact stresses between the tube and collector interface were modeled using contact elements of ANSYS program. Furthermore, the effect of clearance between tube and collector on the residual stresses around of joints was investigated. Some specimens from collector and tube materials were tested at various temperatures and their results were used at rate-independent multi-linear Mises plasticity model for FE analysis. Required connection strength between tube and collector is estimated based on ASME rules and compared with FE results. The results show that the residual tensile stresses could be greatly increased by decreasing of initial clearance. The highest value of residual stresses was observed around of collector holes nevertheless it was considerably lesser than obtained residual stresses in explosive method. The

  6. Optimal design of orientation of PV/T collector with reflectors

    International Nuclear Information System (INIS)

    Hybrid conversion of solar radiation implies simultaneous solar radiation conversion into thermal and electrical energy in the PV/Thermal collector. In order to get more thermal and electrical energy, flat solar radiation reflectors have been mounted on PV/T collector. To obtain higher solar radiation intensity on PV/T collector, position of reflectors has been changed and optimal position of reflectors has been determined by both experimental measurements and numerical calculation so as to obtain maximal concentration of solar radiation intensity. The calculated values have been found to be in good agreement with the measured ones, both yielding the optimal position of the flat reflector to be the lowest (5o) in December and the highest (38o) in June. In this paper, the thermal and electrical efficiency of PV/T collector without reflectors and with reflectors in optimal position have been calculated. Using these results, the total efficiency and energy-saving efficiency of PV/T collector have been determined. Energy-saving efficiency for PV/T collector without reflectors is 60.1%, which is above the conventional solar thermal collector, whereas the energy-saving efficiency for PV/T collector with reflectors in optimal position is 46.7%, which is almost equal to the values for conventional solar thermal collector. Though the energy-saving efficiency of PV/T collector decreases slightly with the solar radiation intensity concentration factor, i.e. the thermal and electrical efficiency of PV/T collector with reflectors are lower than those of PV/T collector without reflectors, the total thermal and electrical energy generated by PV/T collector with reflectors in optimal position are significantly higher than total thermal and electrical energy generated by PV/T collector without reflectors.

  7. Bilinear reduced order approximate model of parabolic distributed solar collectors

    KAUST Repository

    Elmetennani, Shahrazed

    2015-07-01

    This paper proposes a novel, low dimensional and accurate approximate model for the distributed parabolic solar collector, by means of a modified gaussian interpolation along the spatial domain. The proposed reduced model, taking the form of a low dimensional bilinear state representation, enables the reproduction of the heat transfer dynamics along the collector tube for system analysis. Moreover, presented as a reduced order bilinear state space model, the well established control theory for this class of systems can be applied. The approximation efficiency has been proven by several simulation tests, which have been performed considering parameters of the Acurex field with real external working conditions. Model accuracy has been evaluated by comparison to the analytical solution of the hyperbolic distributed model and its semi discretized approximation highlighting the benefits of using the proposed numerical scheme. Furthermore, model sensitivity to the different parameters of the gaussian interpolation has been studied.

  8. Low work function silicon collector for thermionic converters

    Science.gov (United States)

    Chang, K. H.; Shimada, K.

    1976-01-01

    To improve the efficiency of present thermionic converters, single crystal silicon was investigated as a low work function collector material. The experiments were conducted in a test vehicle which resembled an actual thermionic converter. Work function as low as 1.0eV was obtained with an n-type silicon. The stabilities of the activated surfaces at elevated temperatures were tested by raising the collector temperature up to 829 K. By increasing the Cs arrival rate, it was possible to restore the originally activated low work function of the surface at elevated surface temperatures. These results, plotted in the form of Rasor-Warner curve, show a behavior similar to that of metal electrode except that the minimum work function was much lower with silicon than with metals.

  9. Evaluation of Surface Slope Irregularity in Linear Parabolic Solar Collectors

    Directory of Open Access Journals (Sweden)

    F. Francini

    2012-01-01

    Full Text Available The paper describes a methodology, very simple in its application, for measuring surface irregularities of linear parabolic collectors. This technique was principally developed to be applied in cases where it is difficult to use cumbersome instruments and to facilitate logistic management. The instruments to be employed are a digital camera and a grating. If the reflector surface is defective, the image of the grating, reflected on the solar collector, appears distorted. Analyzing the reflected image, we can obtain the local slope of the defective surface. These profilometric tests are useful to identify and monitor the mirror portions under mechanical stress and to estimate the losses caused by the light rays deflected outside the absorber.

  10. A novel collector RL for flotation of bauxite

    Institute of Scientific and Technical Information of China (English)

    卢毅屏; 张国范; 冯其明; 欧乐明

    2002-01-01

    The flotation properties of single minerals such as diaspore, kaolinite and pyrophllite in bauxites were investigated using RL as collector. The effects of regulators and unavoidable ions on flotation were studied. Based on the results of single minerals flotation, the separation experiments of mixed minerals and bauxite ore were carried out. The results of closed circuit test on the ore show that, using RL as collector, Na2CO3 and (NaPO3)6 as modifiers, the grade of Al2O3 and SiO2 are respectively 70.74% and 6.37% in concentrate (Al/Si 11.11), and the recovery of Al2O3 can reach 90.52%.

  11. Towards high throughput screening of nanoparticle flotation collectors.

    Science.gov (United States)

    Abarca, Carla; Yang, Songtao; Pelton, Robert H

    2015-12-15

    To function as flotation collectors for mineral processing, polymeric nanoparticles require a delicate balance of surface properties to give mineral-specific deposition and colloidal stability in high ionic strength alkaline media, while remaining sufficiently hydrophobic to promote flotation. Combinatorial nanoparticle surface modification, in conjunction with high throughput screening, is a promising approach for nanoparticle development. However, efficient automated screening assays are required to reject ineffective particles without having to undergo time consuming flotation testing. Herein we demonstrate that determining critical coagulation concentrations of sodium carbonate in combination with measuring the advancing water contact angle of nanoparticle-saturated glass surfaces can be used to screen ineffective nanoparticles. Finally, none of our first nanoparticle library based on poly(ethylene glycol) methyl ether methacrylate (PEG-methacrylate) were effective flotation collectors because the nanoparticles were too hydrophilic. PMID:26319325

  12. 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)

  13. Owens--Illinois liquid solar collector materials assessment

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, R. L.

    1978-03-01

    The Marshall Space Flight Center (MSFC) was requested by the Energy Research and Development Agency (ERDA) to assess the general suitability of the design and materials and to investigate certain failure modes of the Owens-Illinois (O-I) Sunpak solar energy collector system. The primary problem was the violent fracture of collector tubes, with attendant scattering of glass fragments, under boilout conditions. The data and information generated during the materials analysis segment of this effort are presented. These data were obtained during pressure testing of the individual tubes, performance testing of a complete array of tubes on the MSFC solar simulator apparatus, and in other investigations as noted. The information herein represents only the data directly associated with materials analysis and is not a comprehensive presentation of all the data compiled during the MSFC test program.

  14. 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...

  15. Charged Condensation

    CERN Document Server

    Gabadadze, Gregory

    2008-01-01

    We consider Bose-Einstein condensation of massive electrically charged scalars in a uniform background of charged fermions. We focus on the case when the scalar condensate screens the background charge, while the net charge of the system resides on its boundary surface. A distinctive signature of this substance is that the photon acquires a Lorentz-violating mass in the bulk of the condensate. Due to this mass, the transverse and longitudinal gauge modes propagate with different group velocities. We give qualitative arguments that at high enough densities and low temperatures a charged system of electrons and helium-4 nuclei, if held together by laboratory devices or by force of gravity, can form such a substance. We briefly discuss possible manifestations of the charged condensate in compact astrophysical objects.

  16. Effect of Wall Charge on Striation in Plasma Display Cells

    Institute of Scientific and Technical Information of China (English)

    HE Feng; OUYANG Jiting; CAO Jing; FENG Shuo; MIAO Jinsong; WANG Jianqi

    2007-01-01

    Different configurations and driving voltages have been employed to investigate the effect of the wall charge on the striations in macroscopic plasma display panel (PDP) cells.The experimental results show that a discharge channel near the dielectric layer is indispensable to striation occurring in the anode area during a discharge,while the pre-accumulated charge on the dielectric layer and the surface state are not important.The origin of the striation is related only to the physical process in the cell.The dielectric layer acts as a charge collector during a PDP discharge.

  17. Building integrated solar thermal collectors for heating & cooling applications

    OpenAIRE

    Buker, Mahmut Sami

    2015-01-01

    International Energy Agency Solar Heating & Cooling (IEA SHC) programme states the fact that space/water heating and cooling demand account for over 75% of the energy consumed in single and multi-family homes. Solar energy technology can meet up to 100% of this demand depending on the size of the system, storage capacity, the heat load and the region’s climate. Solar thermal collectors are particular type of heat extracting devices that convert solar radiation into thermal energy through a...

  18. 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.

  19. Evaluation of the Megaduct sweat collector for mineral analysis

    International Nuclear Information System (INIS)

    Accurate measurement of sweat mineral loss is important for whole body mineral balance estimates and dietary reference intake formulation. Currently, common localized sweat collection methods such as the pouch and patch techniques may be limited by skin encapsulation and/or hidromeiosis, which may alter sweat mineral concentrations. The design of the newly developed Megaduct sweat collector may avoid these possible limitations. Therefore, the purpose of this study was to evaluate the utility of the Megaduct sweat collector for mineral analysis. Megaduct sweat collectors were affixed to ten volunteers on the final day of a heat acclimation protocol; collection time, sweat volume, and mineral concentrations of calcium, copper, iron, potassium, sodium, and zinc were measured. Megaduct filling required a collection period of 62 ± 3 min due to a small collection surface (22.1 cm2). The mineral content of the sweat was 0.3 ± 0.1 mmol L−1, 1.5 ± 1.5 µmol L−1, 8.5 ± 2.1 mmol L−1, 43.2 ± 15.0 mmol L−1, and 10.1 ± 5.7 µmol L−1 for Ca, Cu, K, Na, and Zn, respectively. The Megaduct sweat collector appears to avoid skin encapsulation and hidromeiosis, and captures sweat with similar mineral concentrations as reported in the literature for pouches. However, the filling time of the Megaduct (>60 min) may not capture possible changes in sweat mineral concentrations that are documented to occur in as little as 15 to 30 min. (paper)

  20. Normalization and extension of single-collector efficiency correlation equation

    OpenAIRE

    Sethi, Rajandrea; Messina, Francesca; Marchisio, Daniele,

    2015-01-01

    The colloidal transport and deposition are important phenomena involved in many engineering problems. In the environmental engineering field the use of micro- and nano-scale zerovalent iron (M-NZVI) is one of the most promising technologies for groundwater remediation. Colloid deposition is normally studied from a micro scale point of view and the results are then implemented in macro scale models that are used to design field-scale applications. The single collector efficiency concept predic...

  1. Preparation of Curled Micro bers by Electrospinning with Tip Collector

    Institute of Scientific and Technical Information of China (English)

    TANG Cheng-Chun; CHEN Jun-Chi; LONG Yun-Ze; YIN Hong-Xing; SUN Bin; ZHANG Hong-Di

    2011-01-01

    We report on curled polyvinylpyrrolidone (PVP) microfibers fabricated by a modified electrospinning with a small nail as the tip collector. PVP (45 wt%) ethanol solution is electrospun under different working voltages ranging from 10 to 15, 20, 30 and 40kV. It is found that with the increase of working voltage, the proportion of the curled fibers increases and the uniformity of the curled fibers improves, as well as the repeat distance of the curled structures reducing. Particularly, some curled fibers develop into helical structures under relatively high voltages. Further analyses indicate that the formation mechanism for the curled polymer fibers can be ascribed to electrical driven bending instability and/or mechanical jet buckling when hitting the collector surface. This modified electrospinning technique may be a cost-effective approach for the mass production of curled microfibers.%@@ We report on curled polyvinylpyrrolidone(PVP) microfibers fabricated by a modified electrospinning with a small nail as the tip collector.PVP(45 wt%) ethanol solution is electrospun under different working voltages ranging from 10 to 15,20,30 and 40kV.It is found that with the increase of working voltage,the proportion of the curled fibers increases and the uniformity of the curled fibers improves,as well as the repeat distance of the curled structures reducing.Particularly,some curled fibers develop into helical structures under relatively high voltages.Further analyses indicate that the formation mechanism for the curled polymer fibers can be ascribed to electrical driven bending instability and/or mechanical jet buckling when hitting the collector surface.This modified electrospinning technique may be a cost-effective approach for the mass production of curled microfibers.

  2. Parabolic-trough solar collectors and their applications

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Garcia, A.; Zarza, E.; Valenzuela, L. [CIEMAT-Plataforma Solar de Almeria, Ctra. Senes, km. 4, Tabernas (Almeria) 04200 (Spain); Perez, M. [Departamento de Fisica Aplicada, Universidad de Almeria, Almeria 04120 (Spain)

    2010-09-15

    This paper presents an overview of the parabolic-trough collectors that have been built and marketed during the past century, as well as the prototypes currently under development. It also presents a survey of systems which could incorporate this type of concentrating solar system to supply thermal energy up to 400 C, especially steam power cycles for electricity generation, including examples of each application. (author)

  3. Functionalization of Magnetite Nanoparticles as Oil Spill Collector

    OpenAIRE

    Atta, Ayman M.; Al-Lohedan, Hamad A.; Sami A. Al-Hussain

    2015-01-01

    In the present study, a new magnetic powder based on magnetite can be used as a petroleum crude oil collector. Amidoximes based on rosin as a natural product can be prepared from a reaction between hydroxylamine and rosin/acrylonitrile adducts. The produced rosin amidoximes were used as capping agents for magnetite nanoparticles to prepare hydrophobic coated magnetic powders. A new class of monodisperse hydrophobic magnetite nanoparticles was prepared by a simple and inexpensive co-precipitat...

  4. Operational experiences with solar air collector driven desiccant cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    Eicker, Ursula; Schneider, Dietrich; Schumacher, Juergen [Faculty of Civil Engineering, Building Physics and Economics, University of Applied Sciences Stuttgart, Schellingstrasse 24, D-70174 Stuttgart (Germany); Ge, Tianshu; Dai, Yanjun [Faculty of Civil Engineering, Building Physics and Economics, University of Applied Sciences Stuttgart, Schellingstrasse 24, D-70174 Stuttgart (Germany); Institute of Refrigeration and Cryogenics, Solar Energy Research Center, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2010-12-15

    Component performance and seasonal operational experiences have been analysed for desiccant cooling systems powered by solar air collectors. Measurements during the commissioning phase in Spain (public library) and in Germany (production hall) showed that the dehumidification efficiency of the sorption rotors was 80% and the humidification efficiency of the contact evaporators was 85-86%. Only in a two-stage desiccant system monitored in China (laboratory building), a dehumidification efficiency of 88% was reached. The rotary heat exchangers only had 62-68% measured heat recovery efficiency, which is lower than specified. Seasonal performance monitoring carried out in the German installation showed that average seasonal COP's were close to 1.0, when related to all operation hours. COP's increase if low regeneration temperatures are used with low dehumidification rates, which is often sufficient for moderate German climatic conditions, but much less so in the humid Chinese climate. Electrical COP's for the German system including air distribution were between 1.7 and 4.6 and reach values of 7.4, when only additional pressure drops of the desiccant unit are considered. It could be shown that conventional control strategies lead to high auxiliary energy consumption, for example if fixed heating setpoint temperatures are used. Furthermore the solar air collector energy yield was very low in the German system, as regeneration was only used when all other options such as humidification at high air volume flows did not reduce the room air temperature enough. The studies showed that the measured auxiliary energy consumption could be reduced to near zero, if regeneration temperature setpoints were not fixed to constant values. The solar air collector efficiency was good at about 50% both for the flat plate collectors used in Spain and Germany and the Chinese vacuum tube solution. A cost analysis demonstrated the viability of the concept, if some funding of

  5. Direct steam generation in line-focus solar collectors

    Science.gov (United States)

    May, E. K.; Murphy, L. M.

    1983-01-01

    The performance benefits of the direct (in situ) generation of steam in the receiver tube of a line focus solar collector were assessed. Compared to existing technology using steam flash or unfired boiler systems, the in situ technique could produce 25% more steam at a reduced delivery cost. It is indicated that two phase flow instabilities, if present, can be readily controlled, and that the possibility of freezing is not an impediment to using water in cold climates.

  6. Assessment of existing studies of wind loading on solar collectors

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, L. M.

    1981-02-01

    In developing solar collectors, wind loading is the major structural design consideration. Wind loading investigations have focused on establishing safe bounds for steady state loading and verifying rational but initial and conservative design approaches for the various solar collector concepts. As such, the effort has been very successful, and has contributed greatly to both the recognition and qualitative understanding of many of the physical phenomena involved. Loading coefficients corresponding to mean wind velocities have been derived in these prior studies to measure the expected structural loading on the various solar collectors. Current design and testing procedures for wind loading are discussed. The test results corresponding to numerous wind tests on heliostats, parabolic troughs, parabolic dishes, and field mounted photovoltaic arrays are discussed and the applicability of the findings across the various technologies is assessed. One of the most significant consistencies in the data from all the technologies is the apparent benefit provided by fences and field shielding. Taken in toto, these data show that load reductions of three or possibly more seem feasible, though a more thorough understanding of the phenomena involved must be attained before this benefit can be realized. It is recommended that the required understanding be developed to take advantage of this benefit and that field tests be conducted to correlate with both analyses and tests.

  7. Performance Simulation Comparison for Parabolic Trough Solar Collectors in China

    Directory of Open Access Journals (Sweden)

    Jinping Wang

    2016-01-01

    Full Text Available Parabolic trough systems are the most used concentrated solar power technology. The operating performance and optical efficiency of the parabolic trough solar collectors (PTCs are different in different regions and different seasons. To determine the optimum design and operation of the parabolic trough solar collector throughout the year, an accurate estimation of the daily performance is needed. In this study, a mathematical model for the optical efficiency of the parabolic trough solar collector was established and three typical regions of solar thermal utilization in China were selected. The performance characteristics of cosine effect, shadowing effect, end loss effect, and optical efficiency were calculated and simulated during a whole year in these three areas by using the mathematical model. The simulation results show that the optical efficiency of PTCs changes from 0.4 to 0.8 in a whole year. The highest optical efficiency of PTCs is in June and the lowest is in December. The optical efficiency of PTCs is mainly influenced by the solar incidence angle. The model is validated by comparing the test results in parabolic trough power plant, with relative error range of 1% to about 5%.

  8. Thin-film absorber for a solar collector

    Energy Technology Data Exchange (ETDEWEB)

    Wilhelm, W.G.

    1982-02-09

    This invention pertains to energy absorbers for solar collectors, and more particularly to high performance thin film absorbers. The solar collectors comprising the absorber of this invention overcome several problems seen in current systems, such as excessive hardware, high cost and unreliability. In the preferred form, the apparatus features a substantially rigid planar frame with a thin film window bonded to one planar side of the frame. An absorber in accordance with the present invention is comprised of two thin film layers that are sealed perimetrically. In a preferred embodiment, thin film layers are formed from a metal/plastic laminate. The layers define a fluid-tight planar envelope of large surface area to volume through which a heat transfer fluid flows. The absorber is bonded to the other planar side of the frame. The thin film construction of the absorber assures substantially full envelope wetting and thus good efficiency. The window and absorber films stress the frame adding to the overall strength of the collector.

  9. Hybrid solar collector using nonimaging optics and photovoltaic components

    Science.gov (United States)

    Winston, Roland; Yablonovitch, Eli; Jiang, Lun; Widyolar, Bennett K.; Abdelhamid, Mahmoud; Scranton, Gregg; Cygan, David; Kozlov, Alexandr

    2015-08-01

    The project team of University of California at Merced (UC-M), Gas Technology Institute, and Dr. Eli Yablonovitch of University of California at Berkeley developed a novel hybrid concentrated solar photovoltaic thermal (PV/T) collector using nonimaging optics and world record single-junction Gallium arsenide (GaAs) PV components integrated with particle laden gas as thermal transfer and storage media, to simultaneously generate electricity and high temperature dispatchable heat. The collector transforms a parabolic trough, commonly used in CSP plants, into an integrated spectrum-splitting device. This places a spectrum-sensitive topping element on a secondary reflector that is registered to the thermal collection loop. The secondary reflector transmits higher energy photons for PV topping while diverting the remaining lower energy photons to the thermal media, achieving temperatures of around 400°C even under partial utilization of the solar spectrum. The collector uses the spectral selectivity property of Gallium arsenide (GaAs) cells to maximize the exergy output of the system, resulting in an estimated exergy efficiency of 48%. The thermal media is composed of fine particles of high melting point material in an inert gas that increases heat transfer and effectively stores excess heat in hot particles for later on-demand use.

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

    International Nuclear Information System (INIS)

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

  11. Grid Collector: Facilitating Efficient Selective Access from DataGrids

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Kesheng; Gu, Junmin; Lauret, Jerome; Poskanzer, Arthur M.; Shoshani, Arie; Sim, Alexander; Zhang, Wei-Ming

    2005-05-17

    The Grid Collector is a system that facilitates the effective analysis and spontaneous exploration of scientific data. It combines an efficient indexing technology with a Grid file management technology to speed up common analysis jobs on high-energy physics data and to enable some previously impractical analysis jobs. To analyze a set of high-energy collision events, one typically specifies the files containing the events of interest, reads all the events in the files, and filters out unwanted ones. Since most analysis jobs filter out significant number of events, a considerable amount of time is wasted by reading the unwanted events. The Grid Collector removes this inefficiency by allowing users to specify more precisely what events are of interest and to read only the selected events. This speeds up most analysis jobs. In existing analysis frameworks, the responsibility of bringing files from tertiary storages or remote sites to local disks falls on the users. This forces most of analysis jobs to be performed at centralized computer facilities where commonly used files are kept on large shared file systems. The Grid Collector automates file management tasks and eliminates the labor-intensive manual file transfers. This makes it much easier to perform analyses that require data files on tertiary storages and remote sites. It also makes more computer resources available for analysis jobs since they are no longer bound to the centralized facilities.

  12. Air heating solar collectors and its applicability for room ventilation and heating

    International Nuclear Information System (INIS)

    This paper describes the results of the investigation the aim of which was to find new air heating solar collector constructions and easily to accessible materials which it is possible to use as absorbers. We tested the inflatable air heating solar collector construction. Inflatable solar collector gives good correlation with air heating degree and radiation (r=0.93). This type of collectors very sensitive to radiation changes, response time is only about 1 minute. Given type of air heating solar collectors is a good efficiency, the efficiency coefficient is Ș =0.63. Absorber materials (seed boxes made by polypropylene, black colored energy drink cans situated on steel-tinplate ) are tested for room heating and ventilating. Stationary air heating solar collectors for room heating are using in case, when sun radiation exceed 300 W/m2 , otherwise it is not effective or ambient air temperature is cooling room air. Collectors is recommended for room ventilation to reduce heat lost in cold weather. The collectors should be well insulated, especially if they are to be used in early spring, when ambient temperatures are low. These researches show air heating solar collectors applicability in room heating and ventilating, agricultural production drying at Latvia weather conditions Key words: solar collector, air heating, temperature, absorber

  13. Solar energy captured by a curved collector designed for architectural integration

    International Nuclear Information System (INIS)

    Highlights: • We present a new prototype of solar collector for architectural integration. • Equations of the solar radiation on a curved surface. • We compare the energy intercepted by the prototype with the energy intercepted by conventional collectors. • The prototype can be competitive compared with conventional collectors. - Abstract: In this paper we present a prototype for a new type of solar thermal collector designed for architectural integration. In this proposal, the conventional geometry of a flat solar thermal collector is changed to a curved geometry, to improve its visual impact when mounted on a building facade or roof. The mathematical equations for the beam and diffuse solar radiation received by a collector with this geometry are developed for two different orientations, horizontal and vertical. The performance of this curved prototype, in terms of solar radiation received, is compared with a conventional tilted-surface collector for different orientations in Madrid (Spain). The comparison is made for typical clear-sky days in winter and summer as well as for an entire year. The results demonstrate that the curved collector only receives between 12% and 25% less radiation than the conventional tilted-surface collectors when oriented horizontally, depending on the azimuth of the curved surface, although these percentages are reduced to approximately 50% when the collector is oriented vertically

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

    International Nuclear Information System (INIS)

    Highlights: ► Comparative study of PVT air collectors. ► CO2 analysis of all type of PVT air collectors. ► Study of thermal energy, exergy gain and exergy efficiency. ► Exergy efficiency of unglazed hybrid PVT tiles air collector is most efficient. - Abstract: In this paper, comparative analysis of different type of photovoltaic thermal (PVT) air collector namely: (i) unglazed hybrid PVT tiles, (ii) glazed hybrid PVT tiles and (iii) conventional hybrid PVT air collectors have been carried out for the composite climate of Srinagar (India). The comparative study has been carried out in terms of overall thermal energy and exergy gain, exergy efficiency and carbon credit earned by different type of hybrid PVT air collectors. It has been observed that overall annual thermal energy and exergy gain of unglazed hybrid PVT tiles air collector is higher by 27% and 29.3% respectively as compared to glazed hybrid PVT tiles air collector and by 61% and 59.8% respectively as compared to conventional hybrid PVT air collector. It has also been observed that overall annual exergy efficiency of unglazed and glazed hybrid PVT tiles air collector is higher by 9.6% and 53.8% respectively as compared to conventional hybrid PVT air collector. On the basis of comparative study, it has been concluded that CO2 emission reduction per annum on the basis of overall thermal energy gain of unglazed and glazed hybrid PVT tiles air collector is higher by 62.3% and 27.7% respectively as compared to conventional hybrid PVT air collector and on the basis of overall exergy gain it is 59.7% and 22.7%.

  15. Effects of surface properties of (010), (001) and (100) of MnWO4 and FeWO4 on absorption of collector

    Science.gov (United States)

    Qiu, X. Y.; Huang, H. W.; Gao, Y. D.

    2016-03-01

    The atom distribution and electronic properties of (010), (001) and (100) planes of MnWO4 and FeWO4 were studied based on a DFT calculation. The surface stabilities of the three planes were compared according to their surface energies. The most stable one is (010) plane, followed by (001) and (100). (010) and (001) are the main planes for absorption of anion collector ions, which is supported by their bonding relationship and charge density distribution of surface atoms and finally proved by the results of flotation test and stereomicroscope analysis. In addition, the tungsten atoms can be viewed as the absorption site for collectors in (001) plane but not in (010) plane, which can explain the phenomenon in flotation test that the recovery of wolframite can hardly be further boosted even with a high dosage of BHA.

  16. Flow distribution in a solar collector panel with horizontally inclined absorber strips

    DEFF Research Database (Denmark)

    Fan, Jianhua; Shah, Louise Jivan; Furbo, Simon

    2007-01-01

    The objective of this work is to theoretically and experimentally investigate the flow and temperature distribution in a solar collector panel with an absorber consisting of horizontally inclined strips. Fluid flow and heat transfer in the collector panel are studied by means of computational fluid...... dynamics (CFD) calculations. Further, experimental investigations of a 12.5 m(2) solar collector panel with 16 parallel connected horizontal fins are carried out. The flow distribution through the absorber is evaluated by means of temperature measurements on the backside of the absorber tubes. The measured...... rate, properties of solar collector fluid, solar collector fluid inlet temperature and collector tilt angle are shown. The flow distribution through the absorber fins is uniform if high flow rates are used. By decreased flow rate and decreased content of glycol in the glycol/water mixture used as solar...

  17. Design and development of collector for C-band 250 kW CW Klystron

    International Nuclear Information System (INIS)

    The paper presents the design and development of collector for C-band 250 kW high power klystron. The design criteria for the collector assembly is selection of material, vacuum and high temperature compatibility, proper electron beam dispersion, minimum back scattering of electrons and thermal design for proper cooling at high power dissipation. All these aspects have been discussed for collector development in details. The collector has been designed in TRAK and then beam propagation has been analyzed in MAGIC 2D software. The thermal simulation has been done using ANSYS 11.0 (multi-physics). The outer surface of the collector has been grooved to facilitate its proper cooling. Design results are presented for water cooling with different flow rates and channel dimensions. OFHC copper material is chosen for collector which is suitable for vacuum and hydrogen brazing operations and good thermal properties for efficient cooling.

  18. Cleaning Surface Particle Contamination with Ultrapure Water (UPW) Megasonic Flow on Genesis Array Collectors

    Science.gov (United States)

    Allton, J. H.; Calaway, Michael J.; Hittle, J. D.; Rodriquez, M. C.; Stansbery, E. K.; McNamara, K. M.

    2006-01-01

    The hard landing experienced by the Genesis sample return capsule breached the science canister containing the solar wind collectors. This impact into the damp lakebed contaminated collector surfaces with pulverized collector and spacecraft materials and Utah sediment and brine residue. The gold foil, polished aluminum, and bulk metallic glass remained intact, but the solar wind bulk and regime-specific array collectors were jarred loose from their frames and fractured into greater than 10,000 specimens. After a year of investigation and cleaning experimentation, the Genesis Science Team determined that array collectors had 4 classes of contaminants: particles, molecular film, submicron inorganic particulate ("aerosol"), and pre-launch surface contamination. We discuss here use of megasonically energized ultrapure water (UPW) for removing particulate debris from array collector fragments.

  19. Charge independence and charge symmetry

    CERN Document Server

    Miller, G A; Miller, Gerald A; van Oers, Willem T H

    1994-01-01

    Charge independence and charge symmetry are approximate symmetries of nature, violated by the perturbing effects of the mass difference between up and down quarks and by electromagnetic interactions. The observations of the symmetry breaking effects in nuclear and particle physics and the implications of those effects are reviewed.

  20. Charge independence and charge symmetry

    International Nuclear Information System (INIS)

    Charge independence and charge symmetry are approximate symmetries of nature, violated by the perturbing effects of the mass difference between up and down quarks and by electromagnetic interactions. The observations of the symmetry breaking effects in nuclear and particle physics and the implications of those effects are reviewed. (author). 145 refs., 3 tabs., 11 figs

  1. DESIGN AND THERMAL ANALYSIS OF FIXED AND TRACKING FLAT PLATE COLLECTORS

    OpenAIRE

    *Sudarshan T A

    2016-01-01

    This paper focuses on Thermal efficiency analysis of flat plate collectors. The instantaneous efficiency for a collector over a day is calculated. Application of solar energy for domestic and industrial heating purposes has been become very popular. However the effectiveness of presently used fixed flat plate collectors is low due to the moving nature of the energy source. In the present work, an attempt has been made to compare the performance of fixed flat plate water heater with that of he...

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

    International Nuclear Information System (INIS)

    Highlights: • By using nanofluid, smaller and compact solar collector can be produced. • The average value of 220 MJ embodied energy can be saved. • The payback period of using nanofluid solar collector is around 2.4 years. • Around 170 kg less CO2 emissions in average for nanofluid solar collector. • Environmental damage cost is lower with the nanofluid based solar collector. - Abstract: For a solar thermal system, increasing the heat transfer area can increase the output temperature of the system. However, this approach leads to a bigger and bulkier collector. It will then increase the cost and energy needed to manufacture the solar collector. This study is carried out to estimate the potential to design a smaller solar collector that can produce the same desired output temperature. This is possible by using nanofluid as working fluid. By using numerical methods and data from literatures, efficiency, size reduction, cost and embodied energy savings are calculated for various nanofluids. From the study, it was estimated that 10,239 kg, 8625 kg, 8857 kg and 8618 kg total weight for 1000 units of solar collectors can be saved for CuO, SiO2, TiO2 and Al2O3 nanofluid respectively. The average value of 220 MJ embodied energy can be saved for each collector, 2.4 years payback period can be achieved and around 170 kg less CO2 emissions in average can be offset for the nanofluid based solar collector compared to a conventional solar collector. Finally, the environmental damage cost can also be reduced with the nanofluid based solar collector

  3. A Simulated Annealing Algorithm for the Optimization of Multistage Depressed Collector Efficiency

    Science.gov (United States)

    Vaden, Karl R.; Wilson, Jeffrey D.; Bulson, Brian A.

    2002-01-01

    The microwave traveling wave tube amplifier (TWTA) is widely used as a high-power transmitting source for space and airborne communications. One critical factor in designing a TWTA is the overall efficiency. However, overall efficiency is highly dependent upon collector efficiency; so collector design is critical to the performance of a TWTA. Therefore, NASA Glenn Research Center has developed an optimization algorithm based on Simulated Annealing to quickly design highly efficient multi-stage depressed collectors (MDC).

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

    OpenAIRE

    Chii-Dong Ho; Ho-Ming Yeh

    2013-01-01

    The internal-recycle operation effect on collector efficiency in downward-type rectangular solar air heaters with attached fins is theoretically investigated. It is found that considerable collector efficiency is obtainable if the collector has attached fins and the operation is carried out with internal recycling. The recycling operation increases the fluid velocity to decrease the heat transfer resistance, compensating for the undesirable effect of decreasing the heat transfer driving force...

  5. Experimental investigation of tri-functional photovoltaic/thermal solar collector

    International Nuclear Information System (INIS)

    Highlights: • A design of tri-functional photovoltaic/thermal solar collector is proposed. • The performance of tri-functional PV/T collector is investigated and compared. • The tri-functional PV/T collector is flexible to different working modes and variable seasons. - Abstract: Photovoltaic/thermal (PV/T) solar collectors can provide electric power and thermal energy simultaneously. Either PV/T water collectors or PV/T air collectors can be left unused in some seasons because of the freezing problem of water and seasonal demand of hot air. In this paper, a novel design of tri-functional PV/T solar collector was proposed. The collector can work in PV/water-heating mode or PV/air-heating mode according to the seasonal requirements. Experiments were conducted in different working modes under variable conditions to evaluate the performance of collector. The results show that the daily thermal efficiency achieved 46.0% with the electrical efficiency of 10.2% in PV/air-heating mode. The temperature increase of air reached 20 °C with the flow rate of 0.033 kg/s on a sunny day. The instantaneously thermal efficiency at zero reduced temperature were 37.4% and 44.3% as the air flow rate was 0.026 kg/s and 0.032 kg/s respectively. In PV/water-heating mode, the thermal efficiency of the collector was 56.6% at zero reduced temperature, and the daily thermal efficiency of the system was around 36.0%. Compared with solar collectors presented by other authors, the tri-functional PV/T collector is able to operate efficiently in various conditions

  6. Large scale test of a novel back-pass non-perforated unglazed solar air collector

    OpenAIRE

    Paya-Marin, Miguel A.; Lim, James B P; Chen, Jian-Fei; Lawson, R. Mark; Gupta, Bhaskar Sen

    2015-01-01

    This paper describes large scale tests conducted on a novel unglazed solar air collector system. The proposed system, referred to as a back-pass solar collector (BPSC), has on-site installation and aesthetic advantages over conventional unglazed transpired solar collectors (UTSC) as it is fully integrated within a standard insulated wall panel. This paper presents the results obtained from monitoring a BPSC wall panel over one year. Measurements of temperature, wind velocity and solar irradia...

  7. Enhancement of Integrated Solar Collector with Spherical Capsules PCM Affected by Additive Aluminum Powder

    OpenAIRE

    Fatah O. Al Ghuol; Sopian, K.; Shahrir Abdullah

    2016-01-01

    This research aims to study, analyze, design, and construct a solar air heater combined with an appropriate phase-change material (PCM) unit. This solar air heater is analogous to a collector integrating a thermal storage unit and a solar thermal collector. In this study, such single-pass solar air heater in amalgamation with PCM was constructed, and several tests were conducted on this device. During the experiments for the solar collector with PCM (spherical capsules), the temperature varie...

  8. FLOW DISTRIBUTION IN A SOLAR COLLECTOR PANEL WITH HORIZONTAL ABSORBER STRIPS

    OpenAIRE

    Fan, Jianhua; Shah, Louise Jivan; Furbo, Simon

    2007-01-01

    The objective of this work is to theoretically and experimentally investigate the flow and temperature distribution in a solar collector panel with an absorber consisting of horizontal strips. Fluid flow and heat transfer in the collector panel are studied by means of computational fluid dynamics (CFD) calculations. Further, experimental investigations of a 12.5 m² solar collector panel with 16 parallel connected horizontal fins are carried out. The flow distribution through the absorber is e...

  9. Development of flat-plate solar collectors for the heating and cooling of buildings: Executive summary

    Science.gov (United States)

    1978-01-01

    An efficient, low cost, flat-plate solar collector was developed. Computer aided mathematical models of the heat process in the collector were used in defining absorber panel configuration; determining insulation thickness; and in selecting the number, spacing, and material of the covers. Prototypes were built and performance tested. Data from simulated operation of the collector are compared with predicted loads from a number of locations to determine the degree of solar utilization.

  10. Mathematical model of heat-mass exchange processes in a flat solar collector SUN 1

    OpenAIRE

    Tunik Aleksandr Aleksandrovich

    2016-01-01

    In a flat solar collector SUN 1 The active development of environmental friendly energy sources alternative to HPPs is currently of great importance in the world. Such alternative energy sources are: water, ground, sun, wind, biofuel, etc. If we have a look at the atlas of solar energy resources on the territory of Russia, we can make a conclusion, that in many regions of our country solar activity level allows using solar collector. Though the analysis of different models of solar collector ...

  11. Dynamics and control of a solar collector system for near Earth object deflection *

    Institute of Scientific and Technical Information of China (English)

    Shen-Ping Gong; Jun-Feng Li; Yun-Feng Gao

    2011-01-01

    A solar collector system is a possible method using solar energy to deflect Earth-threatening near-Earth objects. We investigate the dynamics and control of a solar collector system including a main collector (MC) and secondary collector (SC).The MC is used to collect the sunlight to its focal point, where the SC is placed and directs the collected light to an asteroid. Both the relative position and attitude of the two collectors should be accurately controlled to achieve the desired optical path. First,the dynamical equation of the relative motion of the two collectors in the vicinity of the asteroid is modeled. Secondly, the nonlinear sliding-mode method is employed to design a control law to achieve the desired configuration of the two collectors. Finally,the deflection capability of this solar collector system is compared with those of the gravitational tractor and solar sail gravitational tractor. The results show that the solar collector is much more efficient with respect to deflection capability.

  12. Influence of Obstacles with Wing Delta Shape on Flat-Plate Air Solar Collector Efficiency

    Directory of Open Access Journals (Sweden)

    P. Gbaha

    2007-01-01

    Full Text Available We present results of our investigation on flat-plate air solar collector equipped with chicanes wing delta shape fixed on non-selective absorber. The absorber was composed of aluminum plate covered with copper. The transparent cover of collector was realized in polycarbonate. This inexpensive device permitted the optimization of collector efficiency by the wing delta chicanes disposed in strips of 10, 13 and 26. Inclination angles used were 10, 20, 30 and 140°. Collector efficiency increased with increasing of slants of chicanes and also with increasing number of the strips. The best efficiency about 81% was obtained with 26 strips at slant 140°.

  13. Economical judge possibility uses solar collectors to warm service water and heating

    International Nuclear Information System (INIS)

    The sun-heated water has been used from before fossil fuels started to determine the direction of our power consumption. This article is focused on the assessing of the use of solar energy as one of inexhaustible resources that has multiple uses, including hot water service systems. Heating is rendered through solar collectors that permit to transform solar energy to warm water. We divide solar collectors into various groups but in principle they are medium temperature collectors and low temperature collectors. The work is directed also on the solar collector market. In our case the market is just at its initial stage as this technology is little known and costs of collectors are rather high, compared to our conditions, on average, they may grow up to 100,000 Slovac crowns per a family house. Because it is the only investment and the costs of operation are minimum throughout the entire collectors lifetime, from the economic point of view, it is a rather advantageous investment. Solar collectors are used in heating and also in hot service water systems in family houses, where they permit to lower costs for the consumption of many kinds of energies. In the hot service water system, solar collectors permit to lower the consumption by almost 70 %. This way of using the solar energy is very prospective and in future it will be used in various sectors. (authors)

  14. Experimental investigation of the performance of five types of solar collectors

    International Nuclear Information System (INIS)

    Highlights: ► Experimental investigation of five types of solar collector has been carried out. ► Readings were reported every 2 h starting from 8:00 am till 4:00 pm for 2 weeks. ► The overall performance of different types of solar collectors has been determined. ► The maximum water temperatures at the outlet reached 92 °C. ► Evacuated tube solar collector has the highest efficiency. - Abstract: Experimental investigation of overall performance, efficiency and reliability of five types of solar collectors is carried out. The systems involved in this study are blue and black coating-selective copper, copper, and aluminum collectors in addition to evacuated tubes collectors. The experiments were carried out during April under same conditions for all collectors. The sky was almost clear with an ambient temperature in the range 18–26 °C. Readings are collected daily from 8:00 am to 4:00 pm. The solar radiation intensity ranged from 154.0 to 1004.33 W/m2. Considering size of application, cost of appliance, quality and maintenance follow-up, results show that evacuated tube, blue and black coating-selective copper collectors are recommended for medium and large scale applications due to their long life, high efficiency ease of maintenance. Aluminum collectors are recommended for small applications like houses.

  15. Variation of emission-adsorption properties in an operating TEC collector

    Science.gov (United States)

    Koriukin, V. A.; Obrezumov, V. P.; Vybyvanets, V. I.

    A high permeability to cesium has been revealed in tungsten layers transferred from the thermionic energy converter (TEC) emitter to collector. Absorbed cesium reduces the energy of cesium desorption from the collector surface. Collector specimens with tungsten films deposited by the emitter-to-collector mass transfer proceeding in the TEC interelectrode space have been studied, and thermoemission microscopy investigations of the process have been carried out. A relationship has been established between the position of the work function minima in curves e(phi) = f(T/TCS) and the cesium vapor pressure.

  16. Development and Evaluation of a Solar Thermal Collector Designed for Drying Grain

    OpenAIRE

    Muhammad Hanif Khalil; Muhammad Ramzan; Masood Ur Rahman Muhammad; Muhammad Aamir Khan

    2012-01-01

    The present research study is on development and performance evaluation of a solar thermal collector that warms up air as transferring medium of heat for drying of grains. A 6 meter long, 4 meter wide and 0.3 meter thick solar thermal collector was constructed in which a V-corrugated steel sheet was used as absorber and a 6 mm thick glass used as glazing. The collector body was fabricated from plywood. The solar thermal collector is linked with a 4 meter high grain storage bin having a diamet...

  17. Nocturnal cooling : Study of heat transfer from a flat-plate solar collector

    OpenAIRE

    Johansson, Helena

    2008-01-01

    This thesis investigates the possibility of using an unglazed flat-plate solar collector as a cooling radiator. The solar collector will be connected to the condenser of a heat pump and used as cooler during nighttime. Daytime the solar collector will be connected to the evaporator of the heat pump and used as heat source. The two widely differing fields of application make special demands on the solar collector. The task is given by the heat pump manufacturer Thermia and the main objective i...

  18. Hybrid Direct Carbon Fuel Cell Performance with Anode Current Collector Material

    DEFF Research Database (Denmark)

    Deleebeeck, Lisa; Kammer Hansen, Kent

    2015-01-01

    The influence of the current collector on the performance of a hybrid direct carbon fuel cell (HDCFC), consisting of solid oxide fuel cell (SOFC) with a molten carbonate-carbon slurry in contact with the anode, has been investigated using current-voltage curves. Four different anode current...... collectors were studied: Au, Ni, Ag, and Pt. It was shown that the performance of the direct carbon fuel cell (DCFC) is dependent on the current collector materials, Ni and Pt giving the best performance, due to their catalytic activity. Gold is suggested to be the best material as an inert current collector...

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

    Energy Technology Data Exchange (ETDEWEB)

    Holck, O. [ed.

    1999-08-01

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

  20. 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.

  1. Final report on MSFC assessment of Owens--Illinois SUNPAK collector problems

    Energy Technology Data Exchange (ETDEWEB)

    Wiesenmaier, B. L.

    1978-07-01

    Marshall Space Flight Center (MSFC) conducted an in-depth assessment of problems encountered with the Owens-Illinois SUNPAK liquid evacuated tube solar collector installed in several ERDA solar system demonstration sites. The assessment included analysis and independent tests of the collector in the MSFC Solar Simulator where the system failure conditions were duplicated. The assessment showed the basic design of the SUNPAK collector to be sound; however, material limitations dictate that near-term applications constraints be recognized by system designers. Subsequent retrofit activity by Owens-Illinois appears to have been effective in demonstrating the integrity of the SUNPAK collector.

  2. Solar-collector studies for solar-heating and -cooling applications. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Liers, H. S.; Yenamandra, N.; Brittle, P. N.; Raymond, M.; Edelman, D. G.

    1979-01-01

    Mirror and lens solar concentrator collectors suitable for space heating, cooling, and hot water applications were surveyed. The scope of the survey includes identification, analysis and comparison for all concentrating collector types for which prototypes and/or market models are or have been built for less than 10X concentration. The survey includes greater than 10X concentration ratios for manufacturers marketing such collectors for space heating and/or cooling applications. Collectors in the conceptual stage are noted and their attributes and disadvantages identified.

  3. Charged Leptons

    CERN Document Server

    Albrecht, J; Babu, K; Bernstein, R H; Blum, T; Brown, D N; Casey, B C K; Cheng, C -h; Cirigliano, V; Cohen, A; Deshpande, A; Dukes, E C; Echenard, B; Gaponenko, A; Glenzinski, D; Gonzalez-Alonso, M; Grancagnolo, F; Grossman, Y; Harnik, R; Hitlin, D G; Kiburg, B; Knoepfe, K; Kumar, K; Lim, G; Lu, Z -T; McKeen, D; Miller, J P; Ramsey-Musolf, M; Ray, R; Roberts, B L; Rominsky, M; Semertzidis, Y; Stoeckinger, D; Talman, R; Van De Water, R; Winter, P

    2013-01-01

    This is the report of the Intensity Frontier Charged Lepton Working Group of the 2013 Community Summer Study "Snowmass on the Mississippi", summarizing the current status and future experimental opportunities in muon and tau lepton studies and their sensitivity to new physics. These include searches for charged lepton flavor violation, measurements of magnetic and electric dipole moments, and precision measurements of the decay spectrum and parity-violating asymmetries.

  4. Assessment center energy collector system of crude Puerto Escondido

    International Nuclear Information System (INIS)

    In this paper the results of the evaluation of the energy system Collector Crude Center of Puerto Escondido in the first half of 2014. By implementing the overall strategy presented Process Analysis developed and implemented an energy assessment procedure allowed characterize current plant conditions, and raise a number of measures and recommendations that lead to improved energy use and reduced environmental impact. It also presents the computational tools used for both process simulation (Hysys v 3.2) as for technical analysis - economic and environmental (Microsoft Excel). (full text)

  5. Fuzzy Universal Model Approximator for Distributed Solar Collector Field Control

    KAUST Repository

    Elmetennani, Shahrazed

    2014-07-01

    This paper deals with the control of concentrating parabolic solar collectors by forcing the outlet oil temperature to track a set reference. A fuzzy universal approximate model is introduced in order to accurately reproduce the behavior of the system dynamics. The proposed model is a low order state space representation derived from the partial differential equation describing the oil temperature evolution using fuzzy transform theory. The resulting set of ordinary differential equations simplifies the system analysis and the control law design and is suitable for real time control implementation. Simulation results show good performance of the proposed model.

  6. Lower end fitting debris collector and end cap spacer grid

    International Nuclear Information System (INIS)

    This patent describes a nuclear reactor having fuel assemblies including an upper end fitting and spaced nuclear fuel rod spacer grids for supporting and spacing a plurality of elongated nuclear fuel rods. Each includes a hollow active portion of nuclear fuel filled cladding intermediate the rod ends and tapering end cap of solid material with a circumferential groove on the rod end which first encounters reactor coolant flow, a lower end filtering debris collector and end cap spacer grid for capturing and retaining deleterious debris carried by reactor coolant before it enters the active region of a fuel assembly and creates fuel rod cladding damage

  7. Fabrication of a focusing soft X-ray collector payload

    Science.gov (United States)

    Davis, J. M.; Decaprio, A. R.; Manko, H.; Ting, J. W. S.

    1976-01-01

    A large area X-ray focusing collector with arc minute resolution and a position sensitive detector capable of operating in the soft X-ray region was developed for use on sounding rockets in studying stellar X-ray sources. The focusing payload consists of the following components, which are described: (1) a crossed paraboloid mirror assembly; (2) an aspect camera and star tracker; (3) a focal plane assembly containing an imaging proportional counter and its preamplifiers, high voltage power supplies and gas system; (4) a fiducial system; and (5) housekeeping, data handling, instrumentation and telemetry electronics. The design, tests, and operation are described.

  8. Theoretical Study of the Compound Parabolic Trough Solar Collector

    Directory of Open Access Journals (Sweden)

    Dr. Subhi S. Mahammed

    2012-06-01

    Full Text Available Theoretical design of compound parabolic trough solar collector (CPC without tracking is presented in this work. The thermal efficiency is obtained by using FORTRAN 90 program. The thermal efficiency is between (60-67% at mass flow rate between (0.02-0.03 kg/s at concentration ratio of (3.8 without need to tracking system.The total and diffused radiation is calculated for Tikrit city by using theoretical equations. Good agreement between present work and the previous work.

  9. In situ built-up air collector with glass cover

    DEFF Research Database (Denmark)

    Kristiansen, Finn Harken; Engelmark, Jesper

    1998-01-01

    with a cover of glass where the horizontal joints were made by means of different methods and materials. As a general principle a water-damming border at the horizontal glass joints was avoided. The test box was built as a solar collector with 14 different horizontal joints between the glasses. The box...... jointing profile. The prototypes were built in the test area of Department of Buildings and Energy. One of the prototypes has the airflow behind the absorber, which is an aluminium plate painted black, whereas the other has the airflow in front of the absorber. Here the black top side of the insulation...

  10. CFD simulation of particle entrapment of steam generator sludge collector/loose parts weir

    International Nuclear Information System (INIS)

    A computational fluid dynamics (CFD) study was performed to explore the performance and interaction of two components designed for Pressurized Water Reactor (PWR) recirculating steam generators: the sludge collector and the loose parts weir. The sludge collector is a passive device located in the upper internals region of a PWR steam generator. The sludge collector's function is to trap sludge, particulates suspended in the secondary side recirculating flow and minimize its deposition on the tube bundle, where it increases susceptibility to tube degradation. The loose parts weir is a separate passive device placed around the sludge collector, which is expected to act as a barrier to prevent any loose parts in the upper internals region from reaching the tube bundle. Loose parts in the steam generator, if not captured, can reach the tube bundle and cause tube wall damage. The loose parts weir is considered for installation in combination with the sludge collector for both new and existing steam generators. Previously, the configuration of the sludge collector was determined based on testing and analysis. Inclusion of the loose parts weir significantly alters the flow field of the sludge collector and thus its overall performance. The purpose of this investigation is to verify the performance of the sludge collector and loose parts weir. A CFD study was performed to evaluate the interaction between the sludge collector and a loose parts weir within the steam generator, which provides insight into the flow redistribution. Models were developed for the sludge collector with and without the loose parts weir using commercial CFD software. Results including the velocity and pressure profile in the steam generator upper internals, as well as fluid mass flow passing through the sludge collector, are presented and discussed for various configurations of the sludge collector and loose parts weir. Sludge particle collection rates are estimated using an empirical correlation

  11. Measuring induced and natural variation in isotope ratios using single-collector and multi-collector ICPMS

    International Nuclear Information System (INIS)

    Full text: The capability of providing isotopic information on the target elements is an important asset of ICPMS. In this presentation, the isotope ratio capabilities of various types of instrumentation (equipped with a quadrupole filter, a time-of-flight analyzer or a double-focusing sector field mass spectrometer and, in the latter case, outfitted with either a single detector or a multi-collector array) will be reviewed. Next, applications from either the author's lab or described in the literature will be deployed for illustrating the many circumstances in which isotope ratio analysis provides information, not accessible using elemental assay. (author)

  12. The use of spider webs as passive bioaerosol collectors

    Science.gov (United States)

    Mattei, Daniel I.; Bleckmann, Charles A.; Bunker, David J.; Maxis, Ike

    2009-05-01

    Spider webs were shown to be effective collectors of bioaerosols and airborne microorganisms. Spider webs were collected and analyzed for microbial content using two general microbial culture mediums. To be considered suitable passive collectors, webs had to satisfy three basic conditions; (1) collection of microorganisms without discrimination based on species or size, (2) collection under variable environmental conditions, and (3) saturation avoidance in the presence of strong microbial launching sources. Samples were collected from four locations near Wright-Patterson Air Force Base, OH, a waste water treatment facility, a commercial garden center, a secluded state park area, and a parking garage located within a medium size metropolitan area. These four locations provided appropriately varied environmental and physical conditions to test the collection parameters previously stated. A simple collection methodology was devised; microscopy cover glass slides were used as collection instruments. The methodology assured sterility during collection and permitted in situ microbial growth, observation, and enumeration. Microbial growth, both bacteria and fungi, were recovered from all collected spider web samples.

  13. Functionalization of Magnetite Nanoparticles as Oil Spill Collector

    Directory of Open Access Journals (Sweden)

    Ayman M. Atta

    2015-03-01

    Full Text Available In the present study, a new magnetic powder based on magnetite can be used as a petroleum crude oil collector. Amidoximes based on rosin as a natural product can be prepared from a reaction between hydroxylamine and rosin/acrylonitrile adducts. The produced rosin amidoximes were used as capping agents for magnetite nanoparticles to prepare hydrophobic coated magnetic powders. A new class of monodisperse hydrophobic magnetite nanoparticles was prepared by a simple and inexpensive co-precipitation method. Iron ions and iodine were prepared by the reaction between ferric chloride and potassium iodide. The structure and morphology of magnetite capped with rosin amidoxime were characterized by Fourier transform infrared spectroscopy (FTIR, X-ray diffraction (XRD, transmission electron microscopy (TEM, zeta potential, thermogravimetric analysis (TGA and dynamic light scattering (DLS. The magnetic properties were determined from vibrating sample magnetometer (VSM analyses. These prepared magnetite nanoparticles were tested as bioactive nanosystems and their antimicrobial effects were investigated. The prepared nanomaterials were examined as a crude oil collector using magnetic fields. The results show promising data for the separation of the petroleum crude oil from aqueous solution in environmental pollution cleanup.

  14. Functionalization of magnetite nanoparticles as oil spill collector.

    Science.gov (United States)

    Atta, Ayman M; Al-Lohedan, Hamad A; Al-Hussain, Sami A

    2015-01-01

    In the present study, a new magnetic powder based on magnetite can be used as a petroleum crude oil collector. Amidoximes based on rosin as a natural product can be prepared from a reaction between hydroxylamine and rosin/acrylonitrile adducts. The produced rosin amidoximes were used as capping agents for magnetite nanoparticles to prepare hydrophobic coated magnetic powders. A new class of monodisperse hydrophobic magnetite nanoparticles was prepared by a simple and inexpensive co-precipitation method. Iron ions and iodine were prepared by the reaction between ferric chloride and potassium iodide. The structure and morphology of magnetite capped with rosin amidoxime were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), zeta potential, thermogravimetric analysis (TGA) and dynamic light scattering (DLS). The magnetic properties were determined from vibrating sample magnetometer (VSM) analyses. These prepared magnetite nanoparticles were tested as bioactive nanosystems and their antimicrobial effects were investigated. The prepared nanomaterials were examined as a crude oil collector using magnetic fields. The results show promising data for the separation of the petroleum crude oil from aqueous solution in environmental pollution cleanup. PMID:25822876

  15. Slope Error Measurement Tool for Solar Parabolic Trough Collectors: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Stynes, J. K.; Ihas, B.

    2012-04-01

    The National Renewable Energy Laboratory (NREL) has developed an optical measurement tool for parabolic solar collectors that measures the combined errors due to absorber misalignment and reflector slope error. The combined absorber alignment and reflector slope errors are measured using a digital camera to photograph the reflected image of the absorber in the collector. Previous work using the image of the reflection of the absorber finds the reflector slope errors from the reflection of the absorber and an independent measurement of the absorber location. The accuracy of the reflector slope error measurement is thus dependent on the accuracy of the absorber location measurement. By measuring the combined reflector-absorber errors, the uncertainty in the absorber location measurement is eliminated. The related performance merit, the intercept factor, depends on the combined effects of the absorber alignment and reflector slope errors. Measuring the combined effect provides a simpler measurement and a more accurate input to the intercept factor estimate. The minimal equipment and setup required for this measurement technique make it ideal for field measurements.

  16. Central inertial collector - a novel device for controlling coolant activity

    International Nuclear Information System (INIS)

    During the construction phase of the early AGRs it was predicted that active oxide would spall from the fuel can surfaces as small particles and deposit elsewhere in the primary circuit such as boilers where they might give dose rates leading to problems of man access. An investigation of existing methods of particle removal devices showed them to have excessively high pressure drops; a new device, the Central Inertial Collector, was developed. In operation the collector is placed immediately downstream (i.e. above) the fuel in the fuel channel. The coolant carrying the spalled oxide particles passes through an orifice and beyond that orifice the particles, by virtue of their inertia, are no longer uniformly distributed across the channel diameter. These regions of high particle concentration are guided out of the main gas flow and, because the fraction of flow taken is small, a higher pressure loss clean-up device is used to remove the particles from this reduced gas volume without imposing a similar high pressure drop on the total gas flow. Overall shaping is such that only smooth bends are imposed upon the main gas flow and, by combining this with careful design to reduce eddy formation, the overall pressure drop is minimised. By carefully selecting suitable channels and utilising the recirculating nature of the primary circuit with a single pass collection efficiency lower than that of the CIC, it is possible to achieve significant circuit clean-up with no power output penalty imposed upon the reactor. (author)

  17. 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.

  18. Results of IEA SHC Task 45: Large Scale Solar Heating and Cooling Systems. Subtask A: “Collectors and Collector Loop”

    DEFF Research Database (Denmark)

    Bava, Federico; Nielsen, Jan Erik; Knabl, Samuel;

    2016-01-01

    The IEA SHC Task 45 Large Scale Solar Heating and Cooling Systems, carried out between January 2011 and December 2014, had the main objective to assist in the development of a strong and sustainable market of large solar heating systems by focusing on high performance and reliability of systems....... Within this project, subtask A had the more specific objectives of investigating ways to evaluate the influence that different operating conditions can have on the collector performance, assure proper and safe installation of large solar collector fields, and guarantee their performance and yearly energy...... output. The results of the different investigations are presented, with a particular focus on how different parameters such as tilt, flow rate and fluid type, can affect the collector efficiency. Other presented results include methods to guarantee and check the thermal performance of a solar collector...

  19. Heavy Nucleus Collector (HNC) project for the NASA Long Duration Exposure Facility (LDEF)

    Science.gov (United States)

    Tarle, Gregory

    1990-01-01

    The primary goal of the heavy nucleus collector (HNC) experiment was to obtain high resolution composition measurements for cosmic ray nuclei in the platinum-lead and actinide region of the periodic table. Secondary objectives include studies of selected groups of elements of lower charge. These goals were to be realized by orbiting a large area array of dielectric nuclear track detectors in space for several years. In this time sufficient actinide nuclei would be collected to determine the nucleosynthetic age of the cosmic radiation and the relative mix of r- and s-process elements in the cosmic ray source. The detector consists of approximately 50 trays assembled in pressurized canisters. Each tray would contain 8 half-stacks (4 stacks total) and an event thermometer which would record the temperature of each event at the time of exposure. Each stack would contain 7 layers of Rodyne-P, CR-39 and Cronar plastic track detectors interleaved with copper stripping foils. Upon return to Earth, detectors would be removed for analysis. Ultraheavy nuclei would have left tracks through the detector sheets that would be made visible after etching in a hot sodium hydroxide solution.

  20. Mesh optimization for microbial fuel cell cathodes constructed around stainless steel mesh current collectors

    KAUST Repository

    Zhang, Fang

    2011-02-01

    Mesh current collectors made of stainless steel (SS) can be integrated into microbial fuel cell (MFC) cathodes constructed of a reactive carbon black and Pt catalyst mixture and a poly(dimethylsiloxane) (PDMS) diffusion layer. It is shown here that the mesh properties of these cathodes can significantly affect performance. Cathodes made from the coarsest mesh (30-mesh) achieved the highest maximum power of 1616 ± 25 mW m-2 (normalized to cathode projected surface area; 47.1 ± 0.7 W m-3 based on liquid volume), while the finest mesh (120-mesh) had the lowest power density (599 ± 57 mW m-2). Electrochemical impedance spectroscopy showed that charge transfer and diffusion resistances decreased with increasing mesh opening size. In MFC tests, the cathode performance was primarily limited by reaction kinetics, and not mass transfer. Oxygen permeability increased with mesh opening size, accounting for the decreased diffusion resistance. At higher current densities, diffusion became a limiting factor, especially for fine mesh with low oxygen transfer coefficients. These results demonstrate the critical nature of the mesh size used for constructing MFC cathodes. © 2010 Elsevier B.V. All rights reserved.

  1. Device for measuring charge density distribution in charged particle beams

    International Nuclear Information System (INIS)

    A device to measure charge density distribution in charged particle beams has been described. The device contains a set of hollow interinsulated current-receiving electrodes, recording system, and cooling system. The invention is aimed at the increase of admissible capacity of the beams measured at the expense of cooling efficiency increase. The aim is achieved by the fact, that in the device a dynamic evaporating-condensational cooling of electrodes is realized by means of cooling agent supply in perpendicular to their planes through the tubes introduced inside special cups. Spreading in radial direction over electrode surface the cooling agent gradually and intensively washes the side surface of the cup, after that, it enters the cooling cavity in the form of vapour-liquid mixture. In the cavity the cooling agent, supplied using dispensina and receiving collectors in which vapoUr is condensed, circulates. In the device suggested the surface of electrode cooling is decreased significantly at the expense of side surface of the cups which receives the electrode heat

  2. METAL-POLYMER SOLAR COLLECTORS WITH MULTICHANNEL ABSORBER FOR MULTIFUNCTIONAL MULTIPURPOSE ENERGY SYSTEMS

    Directory of Open Access Journals (Sweden)

    Doroshenko A.

    2012-08-01

    Full Text Available New modification of liquid-metal-polymer solar collector for solar heating and for creation of multifunctional energy systems on its basis, particularly solar refrigeration systems was developed. A comparative study of several modifications of polymer collectors involving data of a set of foreign researchers was made and high efficiency of the new elaboration was proven.

  3. Evaluation of the flat-plate solar collector system for electric power generation

    Science.gov (United States)

    Athey, R. E.

    1976-01-01

    This evaluation of the flat-plate collector system was designed to determine the number of flat-plate collectors required to generate a given amount of electricity with optimum efficiency. Variable parameters are the temperature of the heat-transport fluid, both to and from the collector field. In the analysis, the efficiency of the flat-plate collectors was coupled to the efficiency of the thermal cycle to calculate optimal overall system efficiencies. Overall system efficiencies for the system are on the order of 3.5 per cent or less. Over two million 4 ft-by-4 ft collectors would be required to produce 100,000 kW(e). Based on the results, it can be shown that the limiting factor in the use of the flat-plate collector system for electric power generation is the efficiency of the collectors. An increase in the overall system efficiency can occur only if the collector efficiency can be increased at higher surface temperatures.

  4. METAL-POLYMER SOLAR COLLECTORS WITH MULTICHANNEL ABSORBER FOR MULTIFUNCTIONAL MULTIPURPOSE ENERGY SYSTEMS

    OpenAIRE

    Doroshenko A.; Danko V.; Turbovets Y.

    2012-01-01

    New modification of liquid-metal-polymer solar collector for solar heating and for creation of multifunctional energy systems on its basis, particularly solar refrigeration systems was developed. A comparative study of several modifications of polymer collectors involving data of a set of foreign researchers was made and high efficiency of the new elaboration was proven.

  5. 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…

  6. Development and Evaluation of a Solar Thermal Collector Designed for Drying Grain

    Directory of Open Access Journals (Sweden)

    Muhammad Hanif Khalil

    2012-01-01

    Full Text Available The present research study is on development and performance evaluation of a solar thermal collector that warms up air as transferring medium of heat for drying of grains. A 6 meter long, 4 meter wide and 0.3 meter thick solar thermal collector was constructed in which a V-corrugated steel sheet was used as absorber and a 6 mm thick glass used as glazing. The collector body was fabricated from plywood. The solar thermal collector is linked with a 4 meter high grain storage bin having a diameter of 2 meter. Performance of this collector was evaluated from November 2011 to January 2012 at seven different convective flow rates of air (7.5, 14.16, 28.30, 56.6, 112.2, 168.5 and 224.4 kg.h-1. The statistical analysis showed that increase in mass flow rate significantly (P > 0.003 increases the performance of the solar collector. Also there was decrease in performance by the change of months of year. The efficiency was 10% higher in November 2011 as compared to January 2012. It was concluded that for drying of grains the solar thermal collector must be operated at high mass flow rates of air from 9:00 am to 4:00 pm to get maximum performance from the solar thermal collector used for grain drying.

  7. An Experimental Study of the Effect of Vortex Shedding on Solar Collector Performance

    Directory of Open Access Journals (Sweden)

    Alaulddin Abdulqader Kadim

    2015-07-01

    Full Text Available In this work, the effect of vortex shedding on the solar collector performance of the parabolic trough solar collector (PTSC was estimated experimentally. The effect of structure oscillations due to wind vortex shedding on solar collector performance degradation was estimated. The performance of PTSC is evaluated by using the useful heat gain and the thermal instantaneous efficiency. Experimental work to simulate the vortex shedding excitation was done. The useful heat gain and the thermal efficiency of the parabolic trough collector were calculated from experimental measurements with and without vortex loading. The prototype of the collector was fabricated for this purpose. The effect of vortex shedding at different operation conditions was examined. The variation of angles of attack and wind velocity leads to different values of vortex loading coefficients and shedding frequencies. The relation between the dynamic characteristics and solar collector performance was evaluated. The finite element method was used to estimate the dynamic characteristic of the solar collector in addition to experimental work to evaluate the relation between the dynamic behavior of the collector and its performance.

  8. Design and performance verification of advanced multistage depressed collectors. [traveling wave tubes for ECM

    Science.gov (United States)

    Kosmahl, H.; Ramins, P.

    1975-01-01

    Design and performance of a small size, 4-stage depressed collector are discussed. The collector and a spent beam refocusing section preceding it are intended for efficiency enhancement of octave bandwidth, high CW power traveling wave tubes for use in ECM.

  9. Parametric studies of an active solar water heating system with various types of PVT collectors

    Indian Academy of Sciences (India)

    Roonak Daghigh; Mohd Hafidz Ruslan; Kamaruzzaman Sopian

    2015-10-01

    This study simulated active photovoltaic thermal solar collectors (PV/T) for hot water production using TRNSYS. The PV/T collectors consist of the amorphous, monocrystalline and polycrystalline. The long-term performances for the glazed and unglazed PV/T collectors were also evaluated. In this simulation, the design parameters used were collector area of 4 m2, collector slope angle of 15 degree and mass flow rate to the collector area ratio of 8–20 kg/hm2. In addition the tank height between 0.9 m to 1.1 m for unglazed PV/T collectors and 0.9 m to 1 m for glazed collectors, as well as the storage tank volume between 200 and 300 L has been used. The climate parameters used were solar radiation levels range of 4–4.9 kWh/m2, the mean ambient temperature in the range of 25–28°C. The results of the simulation indicated that there was an increase in solar fraction and electrical power output of the active PV/T hot water system.

  10. Preliminary design review package on air flat plate collector for solar heating and cooling system

    Science.gov (United States)

    1977-01-01

    Guidelines to be used in the development and fabrication of a prototype air flat plate collector subsystem containing 320 square feet (10-4 ft x 8 ft panels) of collector area are presented. Topics discussed include: (1) verification plan; (2) thermal analysis; (3) safety hazard analysis; (4) drawing list; (5) special handling, installation and maintenance tools; (6) structural analysis; and (7) selected drawings.

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

    DEFF Research Database (Denmark)

    Bacher, Peder; Madsen, Henrik; Perers, Bengt

    2011-01-01

    ) and modelling of the heat dynamics of buildings (Madsen and Holst, 1995). Measurements obtained at a test site in Denmark during the spring 2010 are used for the modelling. The tested collector is a single glazed large area flat plate collector with selective absorber and Teflon anti convection layer...

  12. Emotion, desire and reverie in the consumption practices from the recyclable material collectors

    Directory of Open Access Journals (Sweden)

    Josilene Barbosa do Nascimento

    2014-08-01

    imagination. Thus, pointing out how works the self delusion of the collectors, characteristic of modern consumption, as we watch for the excitement and the individual values governing their consumption practices as pointing work. In this sense, the collectors consume to satiate subjectively established wills: it is the emotional consumption.

  13. 78 FR 38452 - Price for the 2013 Girl Scouts of the USA Young Collector Set

    Science.gov (United States)

    2013-06-26

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE TREASURY United States Mint Price for the 2013 Girl Scouts of the USA Young Collector Set AGENCY: United States... of $54.95 for the 2013 Girl Scouts of the USA Young Collector Set. FOR FURTHER INFORMATION...

  14. Possibility of using strain F9 (Serratia marcescens) as a bio-collector for hema-tite flotation

    Institute of Scientific and Technical Information of China (English)

    Hui-fen Yang; Tian Li; Yan-hong Chang; Hui Luo; Qiong-yao Tang

    2014-01-01

    In this study, we characterized strain F9 and evaluated the interaction between strain F9 and hematite by scanning electron micros-copy (SEM), Fourier transform infrared spectrophotometry (FTIR), zeta potential, flotation, and other methods. The results showed that strain F9 belongs to Serratia marcescens. This brevibacterium had CH2, CH3, and hydroxyl groups on its cell wall, which imparted a strong hy-drophobic and negative charge. Adsorption of strain F9 reduced the zeta potential of the hematite surface and increased the hydrophobicity of the hematite surface, thereby generating hydrophobic hematite agglomerates. At least four groups on strain F9 interacted with the hematite surface, which contributed to chemical interactions of carboxylic groups and hydrophobic association among hydrophobic hematite particles. The possible use of strain F9 as a bio-collector for hematite flotation was proved.

  15. Review of state-of-the-art of solar collector corrosion processes. Task 1 of solar collector studies for solar heating and cooling applications. Final technical progress report

    Energy Technology Data Exchange (ETDEWEB)

    Clifford, J E; Diegle, R B

    1980-04-11

    The state-of-the-art of solar collector corrosion processes is reviewed, and Task 1 of a current research program on use of aqueous heat transfer fluids for solar heating and cooling is summarized. The review of available published literature has indicated that lack of quantitative information exists relative to collector corrosion at the present time, particularly for the higher temperature applications of solar heating and cooling compared to domestic water heating. Solar collector systems are reviewed from the corrosion/service life viewpoint, with emphasis on various applications, collector design, heat transfer fluids, and freeze protection methods. Available information (mostly qualitative) on collector corrosion technology is reviewed to indicate potential corrosion problem areas and corrosion prevention practices. Sources of limited quantitative data that are reviewed are current solar applications, research programs on collector corrosion, and pertinent experience in related applications of automotive cooling and non-solar heating and cooling. A data bank was developed to catalog corrosion information. Appendix A of this report is a bibliography of the data bank, with abstracts reproduced from presently available literature accessions (about 220). This report is presented as a descriptive summary of information that is contained in the data bank.

  16. Performance characteristics curves of the double-pass solar collector with porous media

    International Nuclear Information System (INIS)

    This paper presents the thermal performance characteristics curves of the double-pass solar collector with and without porous media in the second channel. The performance parameters presented by the FRUL, FR(τα) values and the collector time constant. The double-pass solar collector has a width of 120 cm and a length of 240 cm. Both the upper and lower channels can be varied from a minimum depth of 3.5 cm to a maximum depth 10. 5 cm. Steel wool is introduced in the second channel as the porous media. The performance testing has been conducted indoor using a solar simulator made from 45 halogen lamps suspended on the top of the collector. Heaters are used to heat the incoming air into the collector. The mass flow rate are varied and performance curves and parameters are obtained. (Author)

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

    International Nuclear Information System (INIS)

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

  18. 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.

  19. Modeling Heat Flow In a Calorimeter Equipped With a Textured Solar Collector

    Science.gov (United States)

    Jaworske, Donald A.; Allen, Bradley J.

    2001-01-01

    Heat engines are being considered for generating electric power for minisatellite applications, particularly for those missions in high radiation threat orbits. To achieve this objective, solar energy must be collected and transported to the hot side of the heat engine. A solar collector is needed having the combined properties of high solar absorptance, low infrared emittance, and high thermal conductivity. To test candidate solar collector concepts, a simple calorimeter was designed, manufactured, and installed in a bench top vacuum chamber to measure heat flow. In addition, a finite element analysis model of the collector/calorimeter combination was made to model this heat flow. The model was tuned based on observations from the as-manufactured collector/calorimeter combination. In addition, the model was exercised to examine other collector concepts, properties, and scale up issues.

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

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Manuel I.; Rodriguez, Luis R. [Departamento de Fisica, Universidad de Burgos, Avda. Cantabria s/n, 09006 Burgos (Spain)

    2007-09-15

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

  1. Attaching solar collectors to a structural framework utilizing a flexible clip

    Energy Technology Data Exchange (ETDEWEB)

    Kruse, John S

    2014-03-25

    Methods and apparatuses described herein provide for the attachment of solar collectors to a structural framework in a solar array assembly. A flexible clip is attached to either end of each solar collector and utilized to attach the solar collector to the structural framework. The solar collectors are positioned to allow a member of the framework to engage a pair of flexible clips attached to adjacent solar collectors during assembly of the solar array. Each flexible clip may have multiple frame-engaging portions, each with a flange on one end to cause the flexible clip to deflect inward when engaged by the framework member during assembly and to guide each of the frame-engaging portions into contact with a surface of the framework member for attachment.

  2. Normalization and extension of single-collector efficiency correlation equation

    Science.gov (United States)

    Messina, Francesca; Marchisio, Daniele; Sethi, Rajandrea

    2015-04-01

    The colloidal transport and deposition are important phenomena involved in many engineering problems. In the environmental engineering field the use of micro- and nano-scale zerovalent iron (M-NZVI) is one of the most promising technologies for groundwater remediation. Colloid deposition is normally studied from a micro scale point of view and the results are then implemented in macro scale models that are used to design field-scale applications. The single collector efficiency concept predicts particles deposition onto a single grain of a complex porous medium in terms of probability that an approaching particle would be retained on the solid grain. In literature, many different approaches and equations exist to predict it, but most of them fail under specific conditions (e.g. very small or very big particle size and very low fluid velocity) because they predict efficiency values exceeding unity. By analysing particle fluxes and deposition mechanisms and performing a mass balance on the entire domain, the traditional definition of efficiency was reformulated and a novel total flux normalized correlation equation is proposed for predicting single-collector efficiency under a broad range of parameters. It has been formulated starting from a combination of Eulerian and Lagrangian numerical simulations, performed under Smoluchowski-Levich conditions, in a geometry which consists of a sphere enveloped by a control volume. In order to guarantee the independence of each term, the correlation equation is derived through a rigorous hierarchical parameter estimation process, accounting for single and mutual interacting transport mechanisms. The correlation equation provides efficiency values lower than one over a wide range of parameters and is valid both for point and finite-size particles. A reduced form is also proposed by elimination of the less relevant terms. References 1. Yao, K. M.; Habibian, M. M.; Omelia, C. R., Water and Waste Water Filtration - Concepts and

  3. High current and voltage effects in heterojunction bipolar transistor collectors

    International Nuclear Information System (INIS)

    The influence of temperature on speed and power applications is important in heterojunction bipolar transistors with the need for high current drive capability, high cutoff frequency and high voltage handling capability. At high current density, the onset of the Kirk effect is often the main power constraint in the bipolar transistor. An analytical model that accurately describes the physics behind the parasitic electron barrier formation in double heterojunction bipolar transistors in the Si/SiGe, GalnP/GaAs and InP/GaAsSb materials systems at the onset of the Kirk effect is presented. A new lateral current spreading effect due to the electron barrier dependence on collector current density is also discussed. The electron saturation velocity in Ga0.52In0.48P has also been measured as a function of temperature, utilising the Kirk effect in double heterojunction bipolar transistors. An AIGaAs base was used to eliminate the conduction band spike and measurements were carefully performed using pulse biasing to minimise device self-heating. Voltage drops across the base and collector series resistances were also taken into account. The measured room temperature saturation velocity of 5.0 x 106 cm/s decreased rapidly to 2.9 x 106 cm/s at 200 deg C. These results are particularly important for the prediction of frequency performance of Ga0.52In0.48P/(Al)GaAs/Ga0.52In0.48P DHBTs. Avalanche multiplication and hence impact ionisation coefficients for In0.53Ga0.47As have been determined from photomultiplication measurements over the temperature range of 20 - 400 K for a series of p-i-n/n-i-p diodes. Negative temperature dependence is observed in both the electron and hole multiplication of In0.53Ga0.47As at electric fields over 200 kV/cm, contrary to the temperature dependence of collector multiplication previously observed in InP/In0.53Ga0.47As heterojunction bipolar transistors. The results also showed that the breakdown voltage for In0.53Ga0.47As is comparable to GaAs at

  4. Collector Failures on 350 MHz, 1.2 MW CW Klystrons at the Low Energy Demonstration Accelerator (LEDA)

    OpenAIRE

    Rees, D.; Roybal, W.; Bradley, J.

    2000-01-01

    We are currently operating the front end of the accelerator production of tritium (APT) accelerator, a 7 MeV radio frequency quadrapole (RFQ) using three, 1.2 MW CW klystrons. These klystrons are required and designed to dissipate the full beam power in the collector. The klystrons have less than 1500 operational hours. One collector has failed and all collectors are damaged. This paper will discuss the damage and the difficulties in diagnosing the cause. The collector did not critically fail...

  5. Magnetically confined plasma solar collector. [satellite based system in space

    Science.gov (United States)

    Walters, C. T.; Wolken, G., Jr.; Purvis, G. D., III

    1978-01-01

    The possibility of using a plasma medium for collecting solar energy in space is examined on the basis of a concept involving an orbiting magnetic bottle in which a solar-energy-absorbing plasma is confined. A basic system uses monatomic cesium as working fluid. Cesium evaporates from a source and flows into the useful volume of a magnetic bottle where it is photoionized by solar radiation. Ions and electrons lost through the loss cones are processed by a recovery system, which might be a combination of electromagnetic devices and heat engines. This study concentrates on the plasma production processes and size requirements, estimates of the magnetic field required to confine the plasma, and an estimate of the system parameters for a 10 GW solar collector using cesium.

  6. Introducing CFD in the optical simulation of linear Fresnel collectors

    Science.gov (United States)

    Moghimi, M. A.; Rungasamy, A.; Craig, K. J.; Meyer, J. P.

    2016-05-01

    This paper seeks to determine whether the Finite Volume method within a commercially available Computational Fluid Dynamics (CFD) solver (ANSYS Fluent) can model radiation with comparable accuracy to a Monte Carlo ray-tracing software package (SolTrace). A detailed investigation was performed into modeling techniques that can be used to significantly reduce the optical errors traditionally associated with CFD modeling of radiation false scattering and ray effect using a simple optical test case. The strategies formulated in the first part of this paper were used to model a variety of Linear Fresnel Collector Concentrating Solar Power Plants. This paper shows that commercial CFD packages yield accurate results for line focusing concentrating solar applications and simple geometries, validating its use in an integrated environment where both optical and thermal performance of these plants can be simulated and optimized.

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

    Science.gov (United States)

    Mcdonald, G. E. (Inventor)

    1983-01-01

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

  8. Mean wind forces on parabolic-trough solar collectors

    Energy Technology Data Exchange (ETDEWEB)

    Peterka, J.A.; Sinau, J.M.; Cermak, J.E.

    1980-05-01

    The purpose of this study was to investigate characteristics of mean wind loads produced by airflow in and around several configurations of parabolic trough solar collectors with and without a wind fence. Four basic parabolic shapes were investigated as single units and one shape was studied as part of several array fields. One 1:25 scale model of each parabolic shape was constructed for mounting on a force balance to measure two forces and three moments. The effects of several dominant variables were investigated in this study: wind-azimuth (or yaw), trough elevation (or pitch) angle, array field configuration, and protective wind fence characteristics. All measurements were made in a boundary-layer flow developed by the meteorological wind tunnel at the Fluid Dynamics and Diffusion Laboratory of Colorado State University. Results are presented and discussed. (WHK)

  9. Fast time-resolved aerosol collector: proof of concept

    Directory of Open Access Journals (Sweden)

    X.-Y. Yu

    2010-10-01

    Full Text Available Atmospheric particles can be collected in the field on substrates for subsequent laboratory analysis via chemically sensitive single particle methods such as scanning electron microscopy with energy dispersive x-ray analysis. With moving substrates time resolution of seconds to minutes can be achieved. In this paper, we demonstrate how to increase the time resolution when collecting particles on a substrate to a few milliseconds to provide real-time information. Our fast time-resolved aerosol collector ("Fast-TRAC" microscopically observes the particle collection on a substrate and records an on-line video. Particle arrivals are resolved to within a single frame (4–17 ms in this setup, and the spatial locations are matched to the subsequent single particle analysis. This approach also provides in-situ information on particle size and number concentration. Applications are expected in airborne studies of cloud microstructure, pollution plumes, and surface long-term monitoring.

  10. Fast time-resolved aerosol collector: proof of concept

    Directory of Open Access Journals (Sweden)

    X.-Y. Yu

    2010-06-01

    Full Text Available Atmospheric particles can be collected in the field on substrates for subsequent laboratory analysis via chemically sensitive single particle methods such as scanning electron microscopy with energy dispersive x-ray analysis. With moving substrates time resolution of seconds to minutes can be achieved. In this paper, we demonstrate how to increase the time resolution when collecting particles on a substrate to a few milliseconds to provide real-time information. Our fast time-resolved aerosol collector ("Fast-TRAC" microscopically observes the particle collection on a substrate and records an on-line video. Particle arrivals are resolved to within a single frame (4–17 ms in this setup, and the spatial locations are matched to the subsequent single particle analysis. This approach also provides in-situ information on particle size and number concentration. Applications are expected in airborne studies of cloud microstructure, pollution plumes, and surface long-term monitoring.

  11. Optical simulation for a fixed spherical solar collector.

    Science.gov (United States)

    Authier, B; Hill, L; Duban, M; Trarieux, P; Sarazin, M; Nadeau, P

    1979-09-15

    To calculate the absorber dimensions for a fixed spherical solar collector, an optical simulation of the raytracing type is proposed. The physical quantities, which have an effect upon these dimensions, are described as well as the measurement methods. Once the dimensions are determined, the incident flux on the absorber surface can be calculated by the same program in terms of different zenith distances. These calculations can be checked by comparing the calculated flux on the surface of the absorber with the measured flux at different points along the absorber aimed at the full moon instead of at the sun. Through the data obtained from the measurements, fluctuating points of high flux and permanent zones which receive double and triple reflection rays have been studied. PMID:20212809

  12. Development of polymer film solar collectors: A status report

    Science.gov (United States)

    Wilhelm, W. G.; Andrews, J. W.

    1982-08-01

    Solar energy collector panels using polymer film and laminate technology were developed which demonstrate low cost and high thermal performance for residential and commercial applications. This device uses common water in the absorber/heat exchanger which is constructed with polymer film adhesively laminated to aluminum foil as the outer surfaces. Stressed polymer films are also used for the outer window and back surface of the panel forming a high strength structural composite. Rigid polymer foam complements the design by contributing insulation and structural definition. This design resulted in very low weight (3.5 kg/m(2)), potentially very low manufacturing cost (aprox. $11/m(2)), and high thermal performance. The development of polymer materials for this technology will be a key to early commercial success.

  13. Heat Loss Calculation of Compound Honeycomb Solar Collector

    Institute of Scientific and Technical Information of China (English)

    X.S.Ge; Y.Z.Zhang; 等

    1993-01-01

    A simplified technique is described for calculating the heat loss coefficient from the absorber of the solar flat-plate collector with a combined honeycomb.The problem is treated in two ways:the coupled mode and the decoupled mode.In the analysis,the cell wall and glass cover are assumed to be specularly reflecting and diffusely emitting surfaces,while the absorber is a diffusely reflecting and emitting surface.The influences of emissivities of the absorber and the cell wall as wall as well as the aspect ratio on the heat loss coefficient are predicted.The theoretical results are compared with experimental data reported in the literature,and the agreement is good.

  14. Lightweight performance data collectors 2.0 with Eiger support.

    Energy Technology Data Exchange (ETDEWEB)

    Allan, Benjamin A.

    2013-05-01

    We report on the use and design of a portable, extensible performance data collection tool motivated by modeling needs of the high performance computing systems co-design com- munity. The lightweight performance data collectors with Eiger support is intended to be a tailorable tool, not a shrink-wrapped library product, as pro ling needs vary widely. A single code markup scheme is reported which, based on compilation ags, can send perfor- mance data from parallel applications to CSV les, to an Eiger mysql database, or (in a non-database environment) to at les for later merging and loading on a host with mysql available. The tool supports C, C++, and Fortran applications.

  15. Structural evaluation of a DTHR bundle divertor particle collector

    International Nuclear Information System (INIS)

    The purpose of this report is to present a structural evaluation of the current bundle divertor particle collector BDPC design under a peak heat flux in relation to criteria that protect against coolant leakage into the plasma over replacement schedules planned during DTHR operation. In addition, an assessment of the BDPC structural integrity at higher heat fluxes is presented. Further, recommendations for modifications in the current BDPC design that would improve design reliability to be considered in future design studies are described. Finally, experimental test programs directed to establishing materials data necessary in providing greater confidence in subsequent structural evaluations of BDPC designs in relation to coolant leakage over planned replacement schedules are identified

  16. Preliminary Examination of the Interstellar Collector of Stardust

    Science.gov (United States)

    Westphal, A. J.; Allen, C.; Bastien, R.; Borg, J.; Brenker, F.; Bridges, J.; Brownlee, D. E.; Butterworth, A. L.; Floss, C.; Flynn, G.; Frank, D.; Gainsforth, Z.; Gruen, E.; Hoppe, P.; Kearsley, A.; Leroux, H.; Nittler, L. R.; Sandford, S. A.; Simionovici, A.; Stadermann, F.; Stroud, M.; Tsou, P.; Tyliczszak, T.; Warren, J.; Zolensky, M. E.

    2008-01-01

    The findings of the Stardust spacecraft mission returned to earth in January 2006 are discussed. The spacecraft returned two unprecedented and independent extraterrestrial samples: the first sample of a comet and the first samples of contemporary interstellar dust. An important lesson from the cometary Preliminary Examination (PE) was that the Stardust cometary samples in aerogel presented a technical challenge. Captured particles often separate into multiple fragments, intimately mix with aerogel and are typically buried hundreds of microns to millimeters deep in the aerogel collectors. The interstellar dust samples are likely much more challenging since they are expected to be orders of magnitudes smaller in mass, and their fluence is two orders of magnitude smaller than that of the cometary particles. The goal of the Stardust Interstellar Preliminary Examination (ISPE) is to answer several broad questions, including: which features in the interstellar collector aerogel were generated by hypervelocity impact and how much morphological and trajectory information may be gained?; how well resolved are the trajectories of probable interstellar particles from those of interplanetary origin?; and, by comparison to impacts by known particle dimensions in laboratory experiments, what was the mass distribution of the impacting particles? To answer these questions, and others, non-destructive, sequential, non-invasive analyses of interstellar dust candidates extracted from the Stardust interstellar tray will be performed. The total duration of the ISPE will be three years and will differ from the Stardust cometary PE in that data acquisition for the initial characterization stage will be prolonged and will continue simultaneously and parallel with data publications and release of the first samples for further investigation.

  17. Purpose of neuronal method for modeling of solar collector

    Energy Technology Data Exchange (ETDEWEB)

    Salah, Hanini; Moussa, Cherif Si [LBMPt, Universite Yahia Fares de Medea, Quartier Ain D' heb, 2600, Medea (Algeria); Hamid, Abdi [SEEs/MS, B.P. 478, Route de Reggane, Adrar (Algeria); Tariq, Omari [LBMPT, Universite Yahia Fares de Medea, Quartier Ain D' Heb, 2600, Medea (Algeria); SEES/MS, B.P. 478, Route de Reggane, Adrar (Algeria); Unite de developpement des equipments solaires, Bou-Ismail, Tipaza (Algeria)

    2012-07-01

    Artificial Neural Networks (ANN) are widely accepted as a technology offering an alternative way to tackle complex and ill-defined problems. They have been used in diverse applications and have shown to be particularly effective in system identification and modeling as they are fault tolerant and can learn from examples. On the other hand, ANN are able to deal with non-linear problems and once trained can perform prediction at high speed. The objective of this work is the characterization of the integrated collector-storage solar water heater (ICSSWH) by the determination of the day time thermal (and optical) properties, and Night time heat loss coefficient with experimental temperatures, and predictive temperatures by (ANN). Because of that, an ANN has been trained using data for three types of systems, all employing the same collector panel under varying weather conditions. In this way the network was trained to accept and handle a number of unusual cases. The data presented as input were, the working systems (day or night), the type of system, the year, the month, the day, the time, the ambient air temperature, and the solar radiation. The network output is the temperature of the four tanks of storage unit. The correlations coefficients (R2-value) obtained for the training data set was equal to 0.997, 0.998, 0.998, and 0.996 for the four temperatures of each tank. The results obtained in this work indicate that the proposed method can successfully be used for the characterization of the ICSSWH.

  18. Purpose of neuronal method for modeling of solar collector

    Directory of Open Access Journals (Sweden)

    Omari Tariq, Hanini Salah, Cherif Si Moussa, Hamid Abdi

    2012-01-01

    Full Text Available Artificial Neural Networks (ANN are widely accepted as a technology offering an alternative way to tackle complex and ill-defined problems. They have been used in diverse applications and have shown to be particularly effective in system identification and modeling as they are fault tolerant and can learn from examples. On the other hand, ANN are able to deal with non-linear problems and once trained can perform prediction at high speed. The objective of this work is the characterization of the integrated collector-storage solar water heater (ICSSWH by the determination of the day time thermal (and optical properties, and Night time heat loss coefficient with experimental temperatures, and predictive temperatures by (ANN. Because of that, an ANN has been trained using data for three types of systems, all employing the same collector panel under varying weather conditions. In this way the network was trained to accept and handle a number of unusual cases. The data presented as input were, the working systems (day or night, the type of system, the year, the month, the day, the time, the ambient air temperature, and the solar radiation. The network output is the temperature of the four tanks of storage unit. The correlations coefficients (R2 –value obtained for the training data set was equal to 0.997, 0.998, 0.998, and 0.996 for the four temperatures of each tank. The results obtained in this work indicate that the proposed method can successfully be used for the characterization of the ICSSWH.

  19. Convective drying of chilies using a concentrating solar collector

    International Nuclear Information System (INIS)

    A concentrating solar collector was developed for convective drying of green chilies by providing optimum drying environment. A temperature in the range of 45-65 degree C and relative humidity of less than 10% was observed during the drying period provided by the solar collector from 9.00 am to 5.00 pm. Different levels of drying temperature and air mass flow rates were tested to find their effect on drying time of the chilies. The experiment was laid out as a randomized complete block design with a factorial arrangement of the treatments consisting of 3 levels of temperature and 3 levels of air mass flow rate, replicated 3 times. Drying temperature and air mass flow rates effected the drying time significantly. The means comparison showed that minimum drying time of 17.96 h was recorded at high temperature of 65 degree C followed by a drying time of 20.27 and 21.43 h at temperatures of 55 and 45 degree C. The means of air mass flow rates showed that minimum drying time of 18.49 h was noted at high air mass flow rate of 3.50 kg min-1 followed by 20.32 and 20.86 h at air mass flow rates of 1.5 and 2.30 kg min-l. Chilies dried at temperature of 65 degree C and air mass flow rate of 3.5 kg min-1 showed an average drying rate of 0.02 g(H20)hrl cm-2as compared to the slow drying rates at 55 and 45 degree C. It was concluded that chilies must be dried at high temperature and high air mass flow rates to get on time quality dried chilies. (author)

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

    International Nuclear Information System (INIS)

    Highlights: • The thermal performances and cost analysis of the double-pass solar collector with and without fins absorber were discussed. • The theoretical and experimental study on the double-pass solar air collector with and without fins absorber was conducted. • The ratio of AC/AEG or the cost benefit ratio was presented. • The double-pass solar collector with fins absorber is more cost-effective compared to without fins absorber. - Abstract: The performance and cost benefit analysis of double-pass solar collector with and without fins have been conducted. The theoretical model using steady state analysis has been developed and compared with the experimental results. The performance curves of the double-pass solar collector with and without fins, which included the effects of mass flow rate and solar intensity on the thermal efficiency of the solar collector, were obtained. Results indicated that the thermal efficiency is proportional to the solar intensity at a specific mass flow rate. The thermal efficiency increased by 9% at a solar intensity of 425–790 W/m2 and mass flow rate of 0.09 kg/s. The theoretical and experimental analysis showed a similar trend as well as close agreement. Moreover, a cost-effectiveness model has been developed examine the cost benefit ratio of double-pass solar collector with and without fins. Evaluation of the annual cost (AC) and the annual energy gain (AEG) of the collector were also performed. The results show that the double-pass solar collector with fins is more cost-effective compared to the double-pass solar collector without fins for mass flow rate of 0.01–0.07 kg/s. Also, simulations were obtained for the double-pass solar collector with fins at Nusselt number of 5.42–36.21. The energy efficiency of collector increases with the increase of Nusselt number. The results show that by increasing the Nusselt number simultaneously would drop the outlet temperature at any solar intensity. Increase in Nusselt number

  1. 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.

  2. Numerical study of a low temperature water-in-glass evacuated tube solar collector

    International Nuclear Information System (INIS)

    Highlights: • A water-in-glass evacuated tube solar collector is studied via CFD techniques. • Buoyancy effects are simulated using two different numerical approaches. • Temperature increase and pressure drop in the solar collector is predicted. • The thermal and hydraulic performance of the solar collector is obtained. • Numerical thermal efficiency is presented. - Abstract: A numerical study of a low temperature water-in-glass evacuated tube solar collector using Computational Fluid Dynamics (CFD) is presented in this work. The prediction of the water temperature at the outlet of the solar collector manifold was obtained using two different approaches for the simulation of the buoyancy effects; the first model consisted in the use of the Boussinesq approximation (BA) and the second model is to allow the variation of the proprieties with temperature (VPT). Four tests under real operational conditions, based on an Official Mexican Standard, were used to obtain the experimental temperature at the outlet of the solar collector manifold. The results show that the outlet temperature and thermal efficiency of the solar collector using the BA model is closer to the experimental data than those obtained using the VPT model

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

    International Nuclear Information System (INIS)

    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%.

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

    International Nuclear Information System (INIS)

    Highlights: • A novel solar air collector with simplified CPC and open thermosyphon is designed and tested. • Simplified CPC has a much lower cost at the expense of slight efficiency loss. • Nanofluid effectively improves thermal performance of the above solar air collector. • Solar air collector with open thermosyphon is better than that with concentric tube. - Abstract: A novel evacuated tubular solar air collector integrated with simplified CPC (compound parabolic concentrator) and special open thermosyphon using water based CuO nanofluid as the working fluid is designed to provide air with high and moderate temperature. The experimental system has two linked panels and each panel includes an evacuated tube, a simplified CPC and an open thermosyphon. Outdoor experimental study has been carried out to investigate the actual solar collecting performance of the designed system. Experimental results show that air outlet temperature and system collecting efficiency of the solar air collector using nanofluid as the open thermosyphon’s working fluid are both higher than that using water. Its maximum air outlet temperature exceeds 170 °C at the air volume rate of 7.6 m3/h in winter, even though the experimental system consists of only two collecting panels. The solar collecting performance of the solar collector integrated with open thermosyphon is also compared with that integrated with common concentric tube. Experimental results show that the solar collector integrated with open thermosyphon has a much better collecting performance

  5. 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%.

  6. Sorbent-based gaseous mercury removal from flue gas in hybrid particulate collector

    Energy Technology Data Exchange (ETDEWEB)

    H.K. Choi; Y.J. Rhim; S.D. Kim; Lee, S.H. Lee; S.S. Kim [Korea Institute of Energy Research, Daejeon (Republic of Korea)

    2007-07-01

    In this study, the hybrid particulate collector on the gaseous mercury removal performance was estimated. Hybrid particulate collector consists of sorbent injection/adsorption reactor, electrostatic precipitator and fabric filters. The hybrid particulate collector acts not only as a particulate collector but also as an adsorption reactor. Activated carbons injected in the flue gas in front of the injection/adsorption reactor, floating inside of the particulate collector and that attached on the inner walls take important role in mercury removal respectively, and also the activated carbons being attached on the filter surface do. Since the collector itself plays as an adsorption reactor, high mercury removal efficiency can be attained at the low C/Hg ratio. Overall removal efficiency was about 60%. When considering the baseline mercury removal efficiency was over the 50% in the coal fired power plants and MSW incinerators, it could be possible to obtain removal efficiency over the 90% with this hybrid particulate collector. 6 refs., 8 figs., 1 tab.

  7. Theoretical analysis of a novel, portable, CPC-based solar thermal collector for methanol reforming

    International Nuclear Information System (INIS)

    Highlights: • A new concentrating micro solar collector with vacuum insulation is proposed. • Optical and thermal theoretical analyses of the collector have been presented. • The collector can provide heat at 250 °C with an efficiency of approximately 70%. • The collector may be used to drive endothermic reactions such as methanol reforming. - Abstract: In this paper we propose a new solar thermal collector which is suitable for providing heat for endothermic chemical reactions. The particular reaction that is considered is hydrogen production by menthol reforming. The design presented here is based on CPC (compound parabolic concentrator) technology, which can operate without complicated (and costly) tracking systems. It consists of a small, double-sided selective surface receiver in a vacuum envelope comprised of CPC reflectors and a glass aperture cover. Heat absorbed by the receiver is transferred to the working fluid inside micro tubes where the chemical reaction is occurring. This design, to the best of our knowledge, represents the first time that a vacuum package (which creates thermal concentration) has been combined with a CPC-based optical concentrator for thermo-chemical applications. This collector design can convert over 78% of incident solar radiation into heat with a concentration ratio of 1.75, allowing for a high solar-to-fuel efficiency in chemical reactions. This study establishes both the optical and thermal models needed to predict the performance of this type of collector. The results show that the collector stagnates at very high temperatures (up to 600 °C), and can provide solar heat in the form of a small collector for a variety of portable applications – e.g. methanol reforming that requires temperatures of around 250 °C

  8. An improved thermal and electrical model for a solar photovoltaic thermal (PV/T) air collector

    International Nuclear Information System (INIS)

    In this paper, an attempt is made to investigate the thermal and electrical performance of a solar photovoltaic thermal (PV/T) air collector. A detailed thermal and electrical model is developed to calculate the thermal and electrical parameters of a typical PV/T air collector. The thermal and electrical parameters of a PV/T air collector include solar cell temperature, back surface temperature, outlet air temperature, open-circuit voltage, short-circuit current, maximum power point voltage, maximum power point current, etc. Some corrections are done on heat loss coefficients in order to improve the thermal model of a PV/T air collector. A better electrical model is used to increase the calculations precision of PV/T air collector electrical parameters. Unlike the conventional electrical models used in the previous literature, the electrical model presented in this paper can estimate the electrical parameters of a PV/T air collector such as open-circuit voltage, short-circuit current, maximum power point voltage, and maximum power point current. Further, an analytical expression for the overall energy efficiency of a PV/T air collector is derived in terms of thermal, electrical, design and climatic parameters. A computer simulation program is developed in order to calculate the thermal and electrical parameters of a PV/T air collector. The results of numerical simulation are in good agreement with the experimental measurements noted in the previous literature. Finally, parametric studies have been carried out. Since some corrections have been down on thermal and electrical models, it is observed that the thermal and electrical simulation results obtained in this paper is more precise than the one given by the previous literature. It is also found that the thermal efficiency, electrical efficiency and overall energy efficiency of PV/T air collector is about 17.18%, 10.01% and 45%, respectively, for a sample climatic, operating and design parameters.

  9. Theoretical and experimental investigation of plate screen mesh heat pipe solar collector

    International Nuclear Information System (INIS)

    Highlights: • Experimental and computer simulation are performed for wicked heat pipe solar collectors. • Outdoor tests are conducted to compare its performance at different period of the year. • Modest improvement of the collector is achievement by adding fins to the condenser region. • Mesh number of heat pipe porous structure is an important factor in collector design. • Water slightly outperform methanol for such design and operating conditions. - Abstract: Heat pipes are efficient heat transfer devices for solar hot water heating systems. However, the effective downward transfer of solar energy in an integrated heat pipe system provides increased design and implementation options. There is a lack of literature about flat plate wicked assisted heat pipe solar collector, especially with the presence of finned water-cooled condenser wicked heat pipes for solar energy applications. In this paper the consequence of incorporating fins arrays into the condenser region of screen mesh heat pipe solar collector is investigated. An experimental and a transient theoretical model are conducted to compare the performances of solar heating system at different period of the year. A good agreement is shown between the model and the experiment. Two working fluids are investigated (water and methanol) and results reveal that water slightly outperforms methanol with a collector instantaneous efficiency of nearly 60%. That modest improvement is achieved by adding fins to the condenser region of the heat pipes. Results show that the collector efficiency increase as the number of fins increases (upon certain number) and reveal that the mesh number is an important factor which affect the overall collector efficiency. An optimal heat pipe mesh number of 100 meshes/in. with two layers appears to be favorable in such collectors for their design and operating conditions

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

    International Nuclear Information System (INIS)

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

  11. Performance Evaluation of a Nanofluid (CuO-H2O Based Low Flux Solar Collector

    Directory of Open Access Journals (Sweden)

    Lal Kundan

    2013-04-01

    Full Text Available As the fossil fuels are depleting continuously, we know that solar energy harvesting is a significant potential area for new research dimensions. Sun provides us about 1.9 x 108TWh/yr on the land, of which 1.3 x 105 TWh]/yr energy is used. In order to make much use of solar energy on the earth, solar energy harvesting into more usable form (e.g. heat or electricity by using solar energy collectors is important aspect. A solar collector [1] is a device which transfers the collected solar energy to a fluid passing in contact with it. The performance of collector does not only depends upon how effective the absorber is, but also on how effective are the heat transfer and thermal properties (e.g. thermal conductivity, heat capacity of the fluid which is being used. The absorption properties of the fluids generally used in solar collectors are very poor which in turn limits the efficiency of the solar collector. So, there is a need to use energy efficient heat transfer fluids for high efficiency and performance. A relatively new attempt has been made to increase the performance of the solar collector by using nanofluids. Recently developed a new class of working fluids called Nanofluids, found to be possessing better thermal properties over the hosting fluids, can be a good option in the solar collector [5]. In our research work the CuO-water based nanofluid has been tested in the solar collector and their performance is investigated. It has been found that efficiency if the solar collector is increased by 4-6% compared to water

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

    International Nuclear Information System (INIS)

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

  13. A large-panel unglazed roof-integrated liquid solar collector - energy and economic evaluation

    OpenAIRE

    Černe, Boštjan; Medved, Sašo; Arkar, Ciril

    2015-01-01

    Building-integrated unglazed solar collectors are cost effective solar devices that are suitable for various low temperature applications. In this article we present the design and the parametric analyses of the efficiency ofa large-panel unglazed roof-integrated liquid solar collector and an economic evaluation of a large-panel solar-heating system for a swimming pool that is installed at a tourist facility on the Adriatic coast. The design of the solar collector is based on standard metal r...

  14. 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.).

  15. Thin-film flat-plate solar collectors for low-cost manufacture and installation

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, J.W.; Wilhelm, W.G.

    1980-03-01

    A flat-plate solar energy collector design using thin-film plastics in both the absorber and glazing is described. The design approach proceeded in two steps. First, cost constraints on solar collectors were determined using reasonable economic projections. Second, engineering was applied only to those ideas which had hope of falling within those cost boundaries. The use of thin-film plastics appeared most attractive according to these criteria. The nature of the marketing and distribution network can be expected to have a strong impact on the final installed cost of the collector; the proposed design has characteristics which could make possible a reduced price markup.

  16. Electrochemical reaction of sulfur cathodes with Ni foam current collector in Li-S batteries

    Science.gov (United States)

    Liu, Li-Jun; Chen, Yang; Zhang, Zhi-Feng; You, Xiao-Long; Walle, Maru Dessie; Li, Ya-Juan; Liu, You-Nian

    2016-09-01

    The electrochemical properties of sulfur cathode with Ni foam current collector are investigated in detail. Different from sulfur cathode with stain steel current collector, it is interesting found that novel redox peaks at 1.95 V/1.35 V are observed for sulfur cathode with Ni foam. The electrochemical behavior is further verified by ex-situ XRD, SEM and XPS analyses. The results indicate that Ni foam current collector is involved in the redox reaction in Li/S rechargeable battery, and NiS forms at the surface of the Ni foam. These results demonstrate that the sulfur electrode is transformed into NiS.

  17. Design of a system using CPC collectors to collect solar energy and to produce industrial process steam

    Energy Technology Data Exchange (ETDEWEB)

    Hsieh, C.K.

    1979-08-01

    A system has been designed to use CPC collectors to collect solar energy and to generate steam for industrial process heat purposes. The system is divided into two loops with the collectors in the collector loop to operate a preheater and the collectors in the boiler loop to heat water to elevated pressures and temperatures. A flash boiler is used to throttle the heated water to steam. Two types of CPC collectors are chosen. In the collector loop the CPC collectors are fitted with concentric tube receivers. In the boiler loop the collectors employ heat pipes to transmit heat. This design is able to alleviate the scaling and plumbing problems. A fragile receiver tube can also be employed without rupture difficulties. The thermal processes in the collectors were analyzed using a computer modeling. The results were also used to develop a thermodynamic analysis of the total system. Calculations show that the design is technically feasible. The CPC collector is shown to have an efficiency that is very weakly dependent on its operating temperatures, which makes the collector particularly attractive in high temperature applications.

  18. Development and investment of solar collectors for conversion of solar radiation into heat and/or electricity

    International Nuclear Information System (INIS)

    This article describes work on two projects of the National Energy Efficiency Program NEEP 709300036 and NEEP 271003 titled The Model of Solar Collector for Middle Temperature Conversion of Solar Radiation on Heat, and Development and Investigation on Hybrid Solar Collector for Heat and Electricity Generation, respectively. This first project deals with solar collector that transfer solar radiation in heat in area of middle temperature conversion (at temperature above 100 deg C). During entire year it can realize significant saving of electric energy used for preparation of warm water and in central and district heating. During work on the second project, two hybrid solar collectors, their installation, mathematical model, software, and experimental set-up were designed and realized. The first collector had the photovoltaic panel located above the absorber and the second collector had the panel located on the absorber. For both collectors, the results show that efficiency of fossil fuel replacement is 85%

  19. Multiscale computational modeling of a radiantly driven solar thermal collector

    Science.gov (United States)

    Ponnuru, Koushik

    The objectives of the master's thesis are to present, discuss and apply sequential multiscale modeling that combines analytical, numerical (finite element-based) and computational fluid dynamic (CFD) analysis to assist in the development of a radiantly driven macroscale solar thermal collector for energy harvesting. The solar thermal collector is a novel green energy system that converts solar energy to heat and utilizes dry air as a working heat transfer fluid (HTF). This energy system has important advantages over competitive technologies: it is self-contained (no energy sources are needed), there are no moving parts, no oil or supplementary fluids are needed and it is environmentally friendly since it is powered by solar radiation. This work focuses on the development of multi-physics and multiscale models for predicting the performance of the solar thermal collector. Model construction and validation is organized around three distinct and complementary levels. The first level involves an analytical analysis of the thermal transpiration phenomenon and models for predicting the associated mass flow pumping that occurs in an aerogel membrane in the presence of a large thermal gradient. Within the aerogel, a combination of convection, conduction and radiation occurs simultaneously in a domain where the pore size is comparable to the mean free path of the gas molecules. CFD modeling of thermal transpiration is not possible because all the available commercial CFD codes solve the Navier Stokes equations only for continuum flow, which is based on the assumption that the net molecular mass diffusion is zero. However, thermal transpiration occurs in a flow regime where a non-zero net molecular mass diffusion exists. Thus these effects are modeled by using Sharipov's [2] analytical expression for gas flow characterized by high Knudsen number. The second level uses a detailed CFD model solving Navier Stokes equations for momentum, heat and mass transfer in the various

  20. A Physics-Based Charge-Control Model for InP DHBT Including Current-Blocking Effect

    Institute of Scientific and Technical Information of China (English)

    GE Ji; JIN Zhi; SU Yong-Bo; CHENG Wei; WANG Xian-Wai; CHEN Gao-Peng; LIU Xin-Yu

    2009-01-01

    We develop a physics-based charge-control InP double heterojunction bipolar transistor model including three important effects: current blocking, mobile-charge modulation of the base-collector capacitance and velocity-field modulation in the transit time. The bias-dependent base-collector depletion charge is obtained analytically, which takes into account the mobile-charge modulation. Then, a measurement based voltage-dependent transit time formulation is implemented. As a result, over a wide range of biases, the developed model shows good agreement between the modeled and measured S-parameters and cutoff frequency. Also, the model considering current blocking effect demonstrates more accurate prediction of the output characteristics than conventional vertical bipolar inter company results.

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

    Energy Technology Data Exchange (ETDEWEB)

    de Winter, F.

    1976-01-01

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

  2. Design of a single-stage depressed collector for high-power, pulsed gyroklystron amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Saraph, G.P.; Granatstein, V.L.; Lawson, W. [Univ. of Maryland, College Park, MD (United States). Inst. for Plasma Research

    1998-04-01

    Net efficiency of microwave devices can be enhanced by recovering energy from the spent electron beam. Depressed collectors are commonly used for low to medium voltage (<100 kV), CW microwave tubes to achieve this objective. Designs of single-stage depressed collectors for high-power, high-voltage, pulsed gyroklystron amplifiers are presented here. Theoretical velocity distributions of the spent beams from 17.14 and 35.0 GHz relativistic gyroklystron designs are used as input to the particle trajectory simulations. The entire spent beam is collected at the cylindrical collector held at a depressed potential with respect to the interaction cavities. The magnetic field profile is adjusted to achieve collection of electrons at the maximum depressed value of the collector potential. A significant improvement in the device efficiency is estimated for both designs. A possible implementation scheme for the energy recovery using a double anode electron gun is described in detail.

  3. Design of a single-stage depressed collector for high-power, pulsed gyroklystron amplifiers

    International Nuclear Information System (INIS)

    Net efficiency of microwave devices can be enhanced by recovering energy from the spent electron beam. Depressed collectors are commonly used for low to medium voltage (<100 kV), CW microwave tubes to achieve this objective. Designs of single-stage depressed collectors for high-power, high-voltage, pulsed gyroklystron amplifiers are presented here. Theoretical velocity distributions of the spent beams from 17.14 and 35.0 GHz relativistic gyroklystron designs are used as input to the particle trajectory simulations. The entire spent beam is collected at the cylindrical collector held at a depressed potential with respect to the interaction cavities. The magnetic field profile is adjusted to achieve collection of electrons at the maximum depressed value of the collector potential. A significant improvement in the device efficiency is estimated for both designs. A possible implementation scheme for the energy recovery using a double anode electron gun is described in detail

  4. A design method for closed loop solar energy systems with concentrating collectors

    Science.gov (United States)

    Ryan, W. A.

    1982-01-01

    A method of performance prediction and design for closed loop concentrating solar collector systems is presented, along with a comparison of prediction with results using a compound parabolic concentrating collector. The numerical model is an extension of Collares-Pereira and Rabl (1978) model for concentrating collectors to a closed-loop scenario, using a monthly average utilizability factor and the f-chart technique. The predictions were compared with simulations using the TRNSYS program, considering 1.5, 3.0, and 5.0 concentration factors, and a sensible heat storage system. Performance predictions were found to depart from the simulations by an average of 14.04% for all cases, with the predictions giving consistently lower results. The method is concluded to be useful for optimizing collector areas and concentration ratios in closed-loop systems.

  5. Model Predictive Control with Feedforward Strategy for Gas Collectors of Coke Ovens

    Institute of Scientific and Technical Information of China (English)

    Kai Li; Dewei Li; Yugeng Xi; Debin Yin

    2014-01-01

    In coking process, the production quality, equipment life, energy consumption, and process safety are all influenced by the pressure in gas collector pipe of coke oven, which is frequently influenced by disturbances. The main control objectives for the gas collector pressure system are keeping the pressures in collector pipes at appropriate operating point. In this paper, model predictive control (MPC) strategy is introduced to control the collector pressure system due to its ability to handle constraint and good control performance. Based on a method proposed to simplify the system model, an extended state space model predictive control is designed, which combines the feedforward strategy to eliminate the disturbance. The simulation results in a system with two coke ovens show the feasibility and effectiveness of the control scheme.

  6. Identification With a Violent and Sadistic Aggressor: A Rorschach Study of Criminal Debt Collectors.

    Science.gov (United States)

    Nørbech, Peder Chr Bryhn; Grønnerød, Cato; Hartmann, Ellen

    2016-01-01

    This study examined personality functioning in a group of 27 incarcerated criminal debt collectors as assessed by the Rorschach Inkblot Method (RIM; Rorschach, 1921/1942) and the Psychopathy Checklist-Revised (PCL-R; Hare, 2003 ). To explore whether these individuals represent a distinct subgroup within the violent offender population, we compared them to a group of incarcerated homicide offenders (n = 23) without a previous history of significant violence and a group who had committed less serious violent crimes (n = 21). Results revealed significantly more Rorschach indicators of past trauma (Trauma Content Index), aggressive urges (Aggressive Potential) and identification (Aggressive Content) among the debt collectors than the 2 other groups. In addition, debt collectors displayed significantly more interpersonal interest (Sum Human content), and significantly higher scores on the PCL-R. Our findings suggest that the debt collector might be viewed as a hostile variant of psychopathy. PMID:26226052

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

    International Nuclear Information System (INIS)

    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.

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

    Directory of Open Access Journals (Sweden)

    Jing-Yi Chang

    2014-01-01

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

  9. Certification and verification for Northrup model NSC-01-0732 fresnel lens concentrating solar collector

    Science.gov (United States)

    1979-01-01

    Structural analysis and certification of the collector system is presented. System verification against the interim performance criteria is presented and indicated by matrices. The verification discussion, analysis, and test results are also given.

  10. Wind Tunnel Tests of Parabolic Trough Solar Collectors: March 2001--August 2003

    Energy Technology Data Exchange (ETDEWEB)

    Hosoya, N.; Peterka, J. A.; Gee, R. C.; Kearney, D.

    2008-05-01

    Conducted extensive wind-tunnel tests on parabolic trough solar collectors to determine practical wind loads applicable to structural design for stress and deformation, and local component design for concentrator reflectors.

  11. Modelisation of a streaming solar collector with a simultaneous air heater

    Energy Technology Data Exchange (ETDEWEB)

    Pralon, A. [Universidade Federal da Paraiba (Brazil). Departmento de Engenharia Mecanica; Zeghmati, B. [I.U.T. de Belfort Monteveliard (France). Laboratoire de Meetrologie des Interfaces Techniques; Daguenet, M. [Universite de Perpignan (France). Laboratoire de Thermodynamique et Energetique

    1996-01-01

    The behaviour of an air-water mixed solar collector is simulated using meteorological data for Perpignan (France) and one region of Brazil close to the equator. The absorber surface of the collector constitutes a toothed profile. The water streams in open channels while the air flows in the ducts composed by the insulation and the absorber plate. Two cases were considered: the case in which the water and the air move in the same direction and the one in which the fluids move in opposite directions. The temperature distributions of the different components of the collector are calculated by using an implicit finite-differences method. A computer program was developed to evaluate the thermal performances of the collector as a function of various design parameters and water and air flow rates. (author)

  12. Study of thermohydraulic characteristics of upgraded feedwater collector in PGV-440 steam generator

    Energy Technology Data Exchange (ETDEWEB)

    Tarankov, G.A.; Trunov, N.B.; Titov, V.F. [OKB Gidropress (Russian Federation); Urbansky, V.V. [Rovno NPP (Ukraine); Lenkei, I.; Notarosh, M. [Paks NPP (Hungary)

    1995-12-31

    Reconstruction of feedwater distribution collector was performed at unit 1 of Rowno NPP. Main results of measurements of temperatures in water volume, reparation characteristics and impurities distribution are presented. Analysis of tests results and design criteria is given. (orig.).

  13. Development of flat-plate solar collectors for the heating and cooling of buildings

    Science.gov (United States)

    Ramsey, J. W.; Borzoni, J. T.; Holland, T. H.

    1975-01-01

    The relevant design parameters in the fabrication of a solar collector for heating liquids were examined. The objective was to design, fabricate, and test a low-cost, flat-plate solar collector with high collection efficiency, high durability, and requiring little maintenance. Computer-aided math models of the heat transfer processes in the collector assisted in the design. The preferred physical design parameters were determined from a heat transfer standpoint and the absorber panel configuration, the surface treatment of the absorber panel, the type and thickness of insulation, and the number, spacing and material of the covers were defined. Variations of this configuration were identified, prototypes built, and performance tests performed using a solar simulator. Simulated operation of the baseline collector configuration was combined with insolation data for a number of locations and compared with a predicted load to determine the degree of solar utilization.

  14. 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.

  15. Theoretical and experimental study of sheet and tubes hybrid PVT collector

    International Nuclear Information System (INIS)

    Highlights: • A new design of hybrid collectors was modeled and simulated. • Sheet and tubes absorber is user to form the absorber. • The used absorber satisfying simplicity and cost constraints. • A comparison with other existing configurations is performed. • Experimental validation of the mathematical model is detailed. - Abstract: Electrical performance of the hybrid photovoltaic thermal (PVT) collector may improved at increased intensity of solar radiation if the system is set to extract heat from solar cells, which is cooled at the same time. The objective of this work is to study theoretically and experimentally a new configuration of the PVT system which extracts heat from the photovoltaic module. This configuration is tube and sheet integrated into a prototype and tested at the unit of applied research in renewable energy Ghardaïa in the south of Algeria. The advantages of this hybrid collector are better heat absorption and lower production cost compared to other configurations of hybrids collectors

  16. 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.

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

    DEFF Research Database (Denmark)

    Fan, Jianhua; Furbo, Simon

    2008-01-01

    Theoretical and experimental investigations of the flow and temperature distribution in a 12.53 m(2) solar collector panel with an absorber consisting of two vertical manifolds interconnected by 16 parallel horizontal fins have been carried out. The investigations are focused on overheating and...... the influence of the buoyancy effects are considered in the investigations. Further experimental investigations of the solar collector panel are carried out. The flow distribution through the absorber is evaluated by means of temperature measurements on the back of the absorber tubes. The measured...... temperatures are compared to the temperatures determined by the CFD model and there is a good agreement between the measured and calculated temperatures. Calculations with the CFD model elucidate the flow and temperature distribution in the collector The influences of collector fluid flow rate and inlet...

  18. Labile trace metal contribution of the runoff collector to a semi-urban river.

    Science.gov (United States)

    Villanueva, J D; Granger, D; Binet, G; Litrico, X; Huneau, F; Peyraube, N; Le Coustumer, P

    2016-06-01

    In this study, the distribution of labile trace metals (LTMs; Cd, Co, Cr, Cu, Ni, Pb, and Zn) in a semi-urban runoff collector was examined to assess its influence to a natural aqueous system (Jalle River, Bordeaux, France). This river is of high importance as it is part of a natural reserve dedicated to conserving aquatic flora and fauna. Two sampling campaigns with a differing precipitation condition (period 1, spring season; and period 2, summer season associated with storms) were considered. Precipitation and water flow were monitored. The collector is active as it is receptive to precipitation changes. It influences the river through discharging water, contributing LTMs, and channeling the mass fluxes. During period 2 where precipitation rate is higher, 25 % of the total water volume of the river was supplied by the collector. LTMs were detected at the collector. Measurements were done by using diffusive gradient in thin films (DGT) probes deployed during 1, 7, and 14 days in each period. The results showed that in an instantaneous period (day 1 or D1), most of these trace metals are above the environmental quality standards (Cd, Co, Cr, and Zn). The coefficient of determination (r (2) > 0.50) employed confirmed that the LTM concentrations in the downstream can be explained by the collector. While Co and Cr are from the upstream and the collector, Cd, Cu, and Zn are mostly provided by the collector. Ni, however, is mostly delivered by the upstream. Using the concentrations observed, the river can be affected by the collector in varying ways: (1) adding effect, resulting from the mix of the upstream and the collector (if upstream ˂ downstream); (2) diluted (if upstream ˃ downstream); and (3) conservative or unaffected (upstream ~ downstream). The range of LTM mass fluxes that the collector holds are as follows: (1) limited range or ˂10 g/day, Cd (0.04-1.75 g/day), Co (0.08-05.42 g/day), Ni (0.06-1.45 g/day), and Pb (0.08-9.89 g/day); (2) moderate

  19. 3X compound parabolic concentrating (CPC) solar energy collector. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Ballheim, R.W.

    1980-04-25

    Chamberlain engineers designed a 3X compound parabolic concentrating (CPC) collector for the subject contract. The collector is a completely housed, 105.75 x 44.75 x 10.23-inch, 240-pound unit with six each evacuated receiver assemblies, a center manifold and a one-piece glass cover. A truncated version of a CPC trough reflector system and the General Electric Company tubular evacuated receiver have been integrated with a mass producible collector design suitable for operation at 250 to 450/sup 0/F. The key criterion for optimization of the design was minimization of the cost per Btu collected annually at an operating temperature of 400/sup 0/F. The reflector is a 4.1X design truncated to a total height of 8.0 inches with a resulting actual concentration ratio of 2.6 to 1. The manifold is an insulated area housing the fluid lines which connect the six receivers in series with inlet and outlet tubes extending from one side of the collector at the center. The reflectors are polished, anodized aluminum which are shaped by the roll form process. The housing is painted, galvanized steel, and the cover glass is 3/16-inch thick tempered, low iron glass. The collector requires four slope adjustments per year for optimum effectiveness. Chamberlain produced ten 3X CPC collectors for the subject contract. Two collectors were used to evaluate assembly procedures, six were sent to the project officer in Albuquerque, New Mexico, one was sent to Argonne National Laboratory for performance testing and one remained with the Company. A manufacturing cost study was conducted to estimate limited mass production costs, explore cost reduction ideas and define tooling requirements. The final effort discussed shows the preliminary design for application of a 3X CPC solar collector system for use in the Iowa State Capitol complex.

  20. Scanning fiber-optic nonlinear endomicroscopy with miniature aspherical compound lens and multimode fiber collector

    OpenAIRE

    Wu, Yicong; Xi, Jiefeng; Cobb, Michael J.; Li, Xingde

    2009-01-01

    A flexible scanning fiber-optic endomicroscope using a miniature compound lens and a multimode-fiber (MMF) collector was developed for two-photon fluorescence (TPF) and second-harmonic generation (SHG) imaging. The compound lens consisted of a pair of aspherical lenses and exhibited reduced chromatic aberration compared with gradient-index lenses, thus increasing the TPF/SHG collection efficiency. The introduction of a short MMF collector at the distal end of the double-clad fiber of the endo...

  1. Benthic Collector and Grazer Communities Are Threatened by Hemlock Woolly Adelgid-Induced Eastern Hemlock Loss

    OpenAIRE

    Joshua K. Adkins; Lynne K. Rieske

    2015-01-01

    Eastern hemlock (Tsuga canadensis (L.) is a foundation species in eastern North America where it is under threat from the highly invasive, exotic hemlock woolly adelgid (Adelges tsugae). Eastern hemlock is especially important in riparian areas of Central and Southern Appalachia, so we compared the spatial and temporal composition of benthic collector-gatherers, collector-filterers, and grazers in headwater streams with hemlock-dominated riparian vegetation to those with deciduous tree-domi...

  2. Road MAP Towards the Demonstration of a Linear Fresnel Collector Using a Single Tube Receiver

    Energy Technology Data Exchange (ETDEWEB)

    Morin, G.; Platzer, W.; Eck, M.; Uhlig, R.; Haberle, A.; Berger, M.; Zarza, E.

    2006-07-01

    The new linear Fresnel collector technology shows the potential to reach significant market shares in the emerging global solar thermal power market. Our aim is to build and operate a full-size demonstration collector to gather experimental experience and test the theoretical expectations. In preparation for this, a series of analyses have been performed and component development is underway. We present here the recent progress within the project V Demo- Fresnel funded by the German Ministry of Environment, Nature Conservation and Nuclear Safety (BMU) under the number FKZ16UM0038. The point of reference for this project was a Fresnel collector prototype installed in Belgium by the company Solarmundo. In this paper we present the results of the geometrical collector optimisations and the tracking system of the primary mirrors, and show results of the experimental evaluation of the receiver, including the secondary mirror. Models for direct steam generation in horizontal tubes have been investigated for the Fresnel collector. According to the simulation results, unfavourable flows can be avoided, and direct steam generation seems feasible. Mechanical loads on the absorber pipe have been analysed with an FEM-program under static conditions. The maximum stress in the absorber tube which occurs in the superheating section still remains below critical values. The infrastructural planning for the integration of the Fresnel collector at Plataforma Solar de Almeria, Spain, has been carried out. The main purpose of the V Demo-Fresnel project was the theoretical investigation and adaptation of simulation tools to the special technology of the linear Fresnel collector, in order to support the decisions leading to the building of a future demonstration collector. (Author)

  3. Experimental and computational investigation of a new solar integrated collector storage system

    International Nuclear Information System (INIS)

    Highlights: ► ICS represents a viable solution for stand-alone remote applications. ► Stratification is soon recognisable in a discharging 22 l tank of an ICS system. ► LES gives an insight of the mixing mechanism of cold and hot water. ► Mixing is strongly affected by the inflow conditions that need to be controlled. -- Abstract: The paper discusses a combined experimental–numerical analysis of an innovative solar thermal device to be used as an Integrated Collector Storage (ICS) system providing domestic hot water. In this equipment the collector acts also as a storage unit, without requiring an external vessel. Due to its simple configuration, the ICS device was successfully used in several circumstances, especially in extreme situations such as in post-earthquake tent cities or to reach remote users in Africa. In order to assess the efficiency of this collector, the draw-off process was investigated measuring the value of the mean temperature of the water discharging from the tap as cold water filled the collector. In the present configuration the draw-off is not completely optimised and a detailed analysis was carried out in order to investigate the mixing of cold and hot water in the solar collector during the discharge phase. A series of thermocouples was placed in selected positions around the shield of the collector to investigate the evolution of the near wall temperature. Furthermore, a numerical analysis based on Large-Eddy Simulation (LES) of the mixing process inside the collector was carried out using an open source, in-house, finite-volume computational code. Even if some restrictive hypotheses were made on the thermal boundary conditions and the absence of stratification, the LES results gave interesting findings to improve the collector performance.

  4. Optimal yield value of a collector in a vacuum thermoemission energy converter

    Energy Technology Data Exchange (ETDEWEB)

    Bulyga, A.V.

    1977-01-01

    An analytical expression is formulated for determining the optimal height of a potential barrier which limits electron yield from a collector across the near-collector region of the inter-electrode interval of a vacuum thermoemission energy converter. The analysis is based on the concept that thermoemission properties of the emitter are independent of changes in load resistance in which case the resistance of the conducting wires was considered to be given.

  5. Relationships between deflector faults, collapse dolines and collector channel formation: some examples from Slovenia.

    OpenAIRE

    Sustersic France

    2006-01-01

    In some Slovenian caves collector channels gather sinking underground streams and redirect them for potentially long distances parallel to certain faults. The collector channels formed due to ongoing long-term collapse of cave roofs at the points where passages break through the faults, which function as a kind of screen and are termed deflector faults. The fault trends are marked by collapse within the caves, and by active collapse dolines at the surface.

  6. Model of a Solar Collector/Storage System for Industrial Thermal Applications

    OpenAIRE

    Duccio Tempesti; Giampaolo Manfrida; Baldini, A.

    2009-01-01

    A model for the thermodynamic analysis of a non-stationary solar thermal system is described. The main system components are a parabolic tube collector and a steam accumulator, which provides heat for industrial processes. The use of exergy analysis leads to the identification of potentials for performance improvements. The rate of exergy destruction is calculated over a daily operation cycle, showing that the largest exergy destruction takes place at collector level. The effect of v...

  7. Model of a Solar Collector/Storage System for Industrial Thermal Applications

    OpenAIRE

    Manfrida, Giampaolo; Baldini, A.; Tempesti, Duccio

    2009-01-01

    A model for the thermodynamic analysis of a non-stationary solar thermal system is described. The main system components are a parabolic tube collector and a steam accumulator, which provides heat for industrial processes. The use of exergy analysis leads to the identification of potentials for performance improvements. The rate of exergy destruction is calculated over a daily operation cycle, showing that the largest exergy destruction takes place at collector level. The effect of varying th...

  8. Building Space Heating with a Solar-Assisted Heat Pump Using Roof-Integrated Solar Collectors

    OpenAIRE

    Zhiyong Yang; Li Zhu; Yiping Wang

    2011-01-01

    A solar assisted heat pump (SAHP) system was designed by using a roof-integrated solar collector as the evaporator, and then it was demonstrated to provide space heating for a villa in Tianjin, China. A building energy simulation tool was used to predict the space heating load and a three dimensional theoretical model was established to analyze the heat collection performance of the solar roof collector. A floor radiant heating unit was used to decrease the energy demand. The measurement resu...

  9. Solar collector with an absorbent surface in the form of a venetian blind

    Science.gov (United States)

    Kotowski, A.; Derczynski, M.; Machizaud, F.; Flechon, J.

    1984-11-01

    In order to increase the efficiency of flat plate air collectors, we propose the use of absorbing areas in the form of a venetian blind and composed of two planes of discontinuous and parallel lamellae. The theoretical analysis confirmed by the experimental results reveals that the energy parameters resulting from this structure are better than those obtained in the case of collectors using a single plane continuous absorbing surface.

  10. Numerical simulation of heat transfer and fluid dynamics phenomena present in flat plate solar collectors

    OpenAIRE

    Karahasanoglu, Anil

    2013-01-01

    The objective of this work is to study the heat transfer and fluid dynamics phenomena which take place in flat plate solar collectors. The resolution of the steady and unsteady conduction in 1D and 2D domains including composite materials, Smith Hutton problem, Navier-Stokes equations and energy equation are carried out by means of numerical methods. The acquired knowledge in heat transfer and fluid flow is then applied to flat plate solar collectors. A numerical model is created to simulate ...

  11. Perancangan Coupling Antara Solar Collector-Serat Optik Untuk Sistem Pencahayaan Alami

    OpenAIRE

    Bantara Bayu Permana Putra; Sekartedjo Sekartedjo; Agus M. Hatta

    2013-01-01

    Abstrak—Solar lighting merupakan salah satu energi alternatif yang memanfaatkan matahari sebagai sumber cahaya untuk penerangan ruangan.Solar lighting dapat diaplikasikan dengan berbagai macam metode, salah satunya adalah dengan menggunakan serat optik. Sistem solar lighting berbasis serat optik terdiri dari dua komponen utama, yaitu solar collector dan serat optik. Solar collector merupakan alat yang digunakan untuk memantulkan dan mengumpulkan sinar matahari pada satu titik, sedangkan serat...

  12. The Effect of Collector Doping on InP-Based Double Heterojunction Bipolar Transistors

    OpenAIRE

    Topaloğlu, Serkan; DRIESEN, Jörn; PROST, Werner

    2006-01-01

    High current effects on double heterojunction bipolar transistor (DHBT) performance were investigated. Three DHBTs with different collector doping densities were grown and processed. DC and RF measurements were performed to evaluate the influence of collector doping and the related Kirk effect on HBT performance. In addition to these samples, the Kirk effect was proven on SHBTs and the delay of this effect on submicron HBTs was investigated.

  13. REVIEW OF THE EXPERIMENTAL SETTING OF POLYETHYLENE BAGS - COLLECTORS FOR COLLECTING THE SHELLFISH LARVAE

    OpenAIRE

    Peharda, M; Onofri, V.

    2000-01-01

    This work describes and analyses former researches regarding the experi mental setting of polyethylene bags as collectors for collecting the shellfish fry. Basic shellfish cultivation technologies are being briefly described and the literature data regarding the place, season and way of setting the experimental collectors are being detailed. The results of the former researches can be used as references while for the development of the commercial shellfish cultivation on each new location the...

  14. Examination of processes of heat exchange in collector thermosyphons of switching boards high degree of integration.

    OpenAIRE

    Nikolaenko Yu. Е.; Tsyganskiy А. А.

    2007-01-01

    The article presents the research of heat exchange and hydrodynamics of the heat transfer medium in the channels of the collector thermosyphon built into the heat load switching board. The most rational geometry of evaporation channels is chosen. Experimentally obtained dependences of the temperature of switching boards surface on the power of supplied heat flow are given. It is shown that the insertion of collector thermosiphons based on slot channels into the switching board can halve the...

  15. Evaluation of Flotation Collectors in Developing Zero Waste Technology for Processing Iron Ore Tailings

    OpenAIRE

    R. Suhasini1; Ashish Kumar Mallick1; Vasumathi, N.; T.V.Vijaya Kumar1; S. Subba Rao; Prabhakar, S; G.Bhaskar Raju; S.Shiva Kumar2

    2015-01-01

    Reverse cationic column flotation technology is gaining traction in iron ore processing industry for recovering iron values from iron ore slimes/tailings. Development and selection of appropriate collector suitable to the material to be processed plays vital role in the development of the process/technology. Three cationic collectors which are vegetable oil based, biodegradable and environmental friendly were tested for their efficacy in reducing alumina and silica and...

  16. Nanofluid optical property characterization: towards efficient direct absorption solar collectors

    Directory of Open Access Journals (Sweden)

    Otanicar Todd

    2011-01-01

    Full Text Available Abstract Suspensions of nanoparticles (i.e., particles with diameters < 100 nm in liquids, termed nanofluids, show remarkable thermal and optical property changes from the base liquid at low particle loadings. Recent studies also indicate that selected nanofluids may improve the efficiency of direct absorption solar thermal collectors. To determine the effectiveness of nanofluids in solar applications, their ability to convert light energy to thermal energy must be known. That is, their absorption of the solar spectrum must be established. Accordingly, this study compares model predictions to spectroscopic measurements of extinction coefficients over wavelengths that are important for solar energy (0.25 to 2.5 μm. A simple addition of the base fluid and nanoparticle extinction coefficients is applied as an approximation of the effective nanofluid extinction coefficient. Comparisons with measured extinction coefficients reveal that the approximation works well with water-based nanofluids containing graphite nanoparticles but less well with metallic nanoparticles and/or oil-based fluids. For the materials used in this study, over 95% of incoming sunlight can be absorbed (in a nanofluid thickness ≥10 cm with extremely low nanoparticle volume fractions - less than 1 × 10-5, or 10 parts per million. Thus, nanofluids could be used to absorb sunlight with a negligible amount of viscosity and/or density (read: pumping power increase.

  17. A high absorbance material for solar collectors' applications

    International Nuclear Information System (INIS)

    In this work, we proposed a low cost material to be used as an excellent absorber for solar collectors, to increase its thermal efficiency by the high capacity to absorb solar radiation. The material, known as 'smoke black' (soot) can be obtained by the incomplete combustion of organic materials, such as the oxygen-acetylene, paraffin, or candles. A comparative analysis between the optical properties (reflectance, absorbance, and emissivity) measured on three covered copper surfaces (without paint, with a commercial matte black paint, and with smoke black) shows amazing optical results for the smoke black. Reflectance values of the smoke black applied over copper surfaces improves 56 times the values obtained from commercial black paints. High values of emissivity (E=0.9988) were measured on the surface covered with smoke black by spectrophotometry in the UV-VIS range, which represents about 7% of increment as compared with the value obtained for commercial black paints (E=0.938). The proposed high absorbance material can be easily applied on any kind of surfaces at low cost.

  18. Grid collector an event catalog with automated file management

    CERN Document Server

    Ke Sheng Wu; Sim, A; Jun Min Gu; Shoshani, A

    2004-01-01

    High Energy Nuclear Physics (HENP) experiments such as STAR at BNL and ATLAS at CERN produce large amounts of data that are stored as files on mass storage systems in computer centers. In these files, the basic unit of data is an event. Analysis is typically performed on a selected set of events. The files containing these events have to be located, copied from mass storage systems to disks before analysis, and removed when no longer needed. These file management tasks are tedious and time consuming. Typically, all events contained in the files are read into memory before a selection is made. Since the time to read the events dominate the overall execution time, reading the unwanted event needlessly increases the analysis time. The Grid Collector is a set of software modules that works together to address these two issues. It automates the file management tasks and provides "direct" access to the selected events for analyses. It is currently integrated with the STAR analysis framework. The users can select ev...

  19. The UPM high temperature solar collector current status

    International Nuclear Information System (INIS)

    The high temperature solar energy research at Universiti Putra Malaysia (UPM) is an attempt to study the merits of the fixed aperture optics collector for the equatorial region using the concept of the fixed mirror distributed focus (FMDF). The general objective is to look for an alternative source of clean energy and a practical method of converting this energy to usable form for the projected industrialisation program of the country. The FMDF uses a stationary hemisphere bowl to capture the solar irradiance. The UPM bowl has a rim angle of 120 0 with radius of curvature of 27.9 m. This corresponds to an aperture diameter of 48 m and submerges 5.1 m in the ground. The bowl will later be tiled with 2446 square meters of mirror to form a spherical shape. And therefore will be able to collect about 1 MW of solar irradiance at the conical focus formed along the direction of the radius (high concentrated region) which then can be harnessed by different means. In this paper, we will report the current status and future works of the project, under construction at the site. We anticipate that the project will be completed and operated by the year 2000. (Author)

  20. Low-cost evacuated-tube solar collector. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Beecher, D. T.

    1981-02-10

    A prototype design for an evacuated tube air cooled solar collector module has been completed. A product cost study, based on the production of 60,000 of the prototype modules per year (approx. 1,000,000 square feet annually), estimates that the module as shipped would have a cost at inventory of $7.09 to $7.40 per square foot of aperture. Computer programs were developed to predict the optical and thermal performance of the module. Antireflective coatings (porous aluminum oxide) which could be formed by spraying or dipping were demonstrated but degraded more rapidly when exposed to a high humidity ambient than acid etched films. A selective black chromium oxide multi-layered graded film was vapor deposited which had an absorptivity of about 0.9 and an emissivity of 0.03. When the film was heated to temperatures of 400/sup 0/C in a gettered vacuum for as little as 24 hours, however, irreversible changes took place both between and within coating layers which resulted in ..cap alpha.. decreasing to about 0.73 and epsilon increasing to 0.14. The product cost studies indicate that module design changes are warranted to reduce product cost prior to tooling for production.

  1. Temperature dependent capacity contribution of thermally treated anode current collectors in lithium ion batteries

    International Nuclear Information System (INIS)

    Highlights: ► We studied the influence of the thermal treatment of current collectors on the energy capacity. ► Different current collectors show different thermal treatment effect on performance. ► The non-negligible capacity contribution is closely related to the treatment temperatures. ► Our results could be beneficial to designing battery architectures. - Abstract: Metal current collectors, offering a good connection between the active materials and the external circuit, is an important component in a rechargeable lithium ion battery. Some necessary thermal treatment in the battery fabrication and assembly procedure results in current collectors with some non-negligible reversible energy capacities; however, these energy capacities were negligible in the previous references. In this research, for the first time, we investigated the influence of the thermal treatment of current collectors (such as copper foil and stainless steel disk) on energy capacities. Our results indicate that different current collector materials have different thermal treatment effects on their electrochemical performance. The non-negligible capacity contribution is closely related to the treatment temperature.

  2. 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.

  3. Design of a solar-assisted drying system using the double-pass solar collector

    International Nuclear Information System (INIS)

    A solar-assisted drying system that uses the double-pass solar collector with porous media in the second channel has been designed and constructed at the Solar Energy Research Park, Universiti Kebangsaan Malaysia. The drying system has a total of six double-pass solar collectors. Each collector has a length of 240 cm and a width of 120 cm. The upper channel depth is 3.5 cm and the lower channel depth is 10.5 cm. The lower channel is filled up with steel wool as the porous media. The solar collectors are arranged as 2 banks of 3 collectors each in series. Internal manifold are used to connect the collectors. An auxiliary heater source is installed to supply heat under unfavourable solar radiation conditions. An on/off controller is used to control the startup and shutdown of the auxiliary heater. An outlet temperature of 80-90 0C can be achieved at a solar radiation range of 800-900 W/m3, ambient temperature of 29 degree C and flow rate of O.20 kg/s. (Author)

  4. Effect of collector size on forest litter-fall collection and analysis

    Energy Technology Data Exchange (ETDEWEB)

    McShane, M.C.; Carlile, D.W.; Hinds, W.T.

    1983-01-01

    Litter fall is commonly collected for a variety of ecological studies. This study was designed to test the effect of collector size on the precision of forest litter-fall estimates and on the time involved in laboratory sample sorting. Collectors varied in size from 0.010 to 0.933 m/sup 2/ and were physically nested, the smaller units with in larger units. Ten of these collector combinations were randomly placed on a 1-ha plot in a Douglas-fir/western hemlock (Pseudotsuga menziesii (Mirb.) Franco/Tsuga heterophylla (Raf.) Sarg.) stand in H.J. Andrews Experimental Forest. Collections were made monthly and records were kept of the time required to sort the litter into needles, epiphytes, and miscellaneous categories. Based on a definition of precision as +/- 10% of the mean, 90% of the time, results indicate (i) that the cost of obtaining precise estimates of needle fall decreases with decreasing collector size to 0.010 m/sup 2/, (ii) that collectors of any size can be used to obtain estimates of total litter fall if the number of collectors required to obtain precise results is determined, and (iii) that precise estimates of epiphyte biomass require large numbers of samplers and are not cost effective.

  5. Genesis Solar Wind Science Canister Components Curated as Potential Solar Wind Collectors and Reference Contamination Sources

    Science.gov (United States)

    Allton, J. H.; Gonzalez, C. P.; Allums, K. K.

    2016-01-01

    The Genesis mission collected solar wind for 27 months at Earth-Sun L1 on both passive and active collectors carried inside of a Science Canister, which was cleaned and assembled in an ISO Class 4 cleanroom prior to launch. The primary passive collectors, 271 individual hexagons and 30 half-hexagons of semiconductor materials, are described in. Since the hard landing reduced the 301 passive collectors to many thousand smaller fragments, characterization and posting in the online catalog remains a work in progress, with about 19% of the total area characterized to date. Other passive collectors, surfaces of opportunity, have been added to the online catalog. For species needing to be concentrated for precise measurement (e.g. oxygen and nitrogen isotopes) an energy-independent parabolic ion mirror focused ions onto a 6.2 cm diameter target. The target materials, as recovered after landing, are described in. The online catalog of these solar wind collectors, a work in progress, can be found at: http://curator.jsc.nasa.gov/gencatalog/index.cfm This paper describes the next step, the cataloging of pieces of the Science Canister, which were surfaces exposed to the solar wind or component materials adjacent to solar wind collectors which may have contributed contamination.

  6. [Flotation mechanism on Mycobacterium phlei and adsorption of Pb2+ by collectors].

    Science.gov (United States)

    Zhou, Dong-qin; Wei, De-zhou

    2006-02-01

    The possibility of removal of heavy metals from waste water by adsorption flotation using Mycobacterium phlei as adsorbent was investigated, and the collection mechanism of collectors on adsorbent was analyzed. From the single flotation tests, it shows that cationic collectors have a stronger collecting ability for Mycobacterium phlei than anionic collectors. The adsorptive flotation experiment shows that floatability process occurred within 10 minutes, the recovery of Mycobacterium phlei and the removing rate of Pb2+ are high by using cationic collectors during pH value from 4 to 7. At 45mmol/L of Di-buty lamine as collector, and 4.75 of pH, the recovery of Mycobacterium phlei and the removing rate of Pb2+ are 92 % and 98%. The isoelectric point of Mycobacterium phlei is 3.09 at pH of the solution, which increased when Pb2+ or Di-buty lamine is adsorption by Mycobacterium phlei. The good floatability of Mycobacterium phlei with cationic collectors results from the intense zeta potential on the surface of cell, Adsorptive flotation may have practical applications for the removal of hazardous metals from contaminated water supplies. PMID:16686201

  7. Parametric sensitivity studies on the performance of a flat plate solar collector in transient behavior

    International Nuclear Information System (INIS)

    Highlights: • Parametric studies of a flat plate solar collector is developed. • The model predicts the temperature profile of all the components of the collector and of the working fluid. • A simulation program was constructed to study the effect parameters. • The optimal performance and design of solar collector system was carried out. - Abstract: In this paper, a numerical investigation of flat plate solar collectors is developed to determine the optimal performance and design parameters of these solar to thermal energy conversion systems. The collector is used to supply hot water. It consists of three main components, namely a transparent cover, an absorber and a transfer fluid. A transient simulation method has been developed to characterize the dynamic behavior. The model was established regarding the energy balance analysis. A set of equations representing the model was simultaneously solved. The results are used to investigate the effect of various parameters on the performance of the collector such as outlet water temperature and overall heat loss coefficient. The overall methodology has been developed on environmental data which are characteristic of the city of Gabes in Tunisia

  8. Study of an improved integrated collector-storage solar water heater combined with the photovoltaic cells

    International Nuclear Information System (INIS)

    Highlights: • Simulation of an enhanced ICSSWH system combined with PV panel was conducted. • The present model dose not uses any photovoltaic driven water pump. • High packing factor and tank water mass are caused to high PVT system efficiency. • Larger area of the collector is resulted to lower total PVT system efficiency. - Abstract: A photovoltaic–thermal (PVT) module is a combination of a photovoltaic (PV) panel and a thermal collector for co-generation of heat and electricity. An integrated collector-storage solar water heater (ICSSWH) system, due to its simple and compact structure, offers a promising approach for the solar water heating in the varied climates. The combination of the ICSSWH system with a PV solar system has not been reported. In this paper, simulation of an enhanced ICSSWH system combined with the PV panel has been conducted. The proposed design acts passive. Therefore, it does not use any photovoltaic driven water pump to maintain a flow of water inside the collector. The effects of the solar cell packing factor, the tank water mass and the collector area on the performance of the present PVT system have been investigated. The simulation results showed that the high solar cell packing factor and the tank water mass are caused to the high total PVT system efficiency. Also, larger area of the collector is resulted to lower total PVT system efficiency

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

    Directory of Open Access Journals (Sweden)

    Guoying Xu

    2015-12-01

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

  10. Flotation and adsorption of quaternary ammonium salts collectors on kaolinite of different particle size

    Institute of Scientific and Technical Information of China (English)

    Jiang Hao; Liu Guorong; Hu Yuehua; Xu Longhua; Yu Yawen; Xie Zhen; Chen Haochuan

    2013-01-01

    The flotation behaviors of decyltrimethylammonium (103C),dodecyltrimethylammonium chloride (DTAC),tetradecyltrimethylammonium chloride (TTAC) and cetyltrimethylammonium chloride (CTAC) on kaolinite of different particle size fraction were studied.The adsorbed amount and adsorption isotherms of collectors on kaolinite were determined for painstaking investigation into the adsorption of quaternary amines at kaolinite-water interface by ultraviolet spectrophotometer methods.The flotation results show that the flotation recovery of kaolinite of different particle fraction increases with an increase in pH when 103C,DTAC,TrAC and CTAC are used as collectors.As the concentration of collectors increases,the flotation recovery increases.Particle size of kaolinite has a strong effect on flotation.The flotation recovery of fine kaolinite decreases with the carbon chain of quaternary ammonium salts collectors increasing,while coarse kaolinite is on the contrary.The adsorbed amount tests and adsorption isotherms show that adsorbed amount increases when the particle size of kaolinite increases or when the carbon chain length of quaternary ammonium salts increases.Within the range of flotation collector concentration,the longer the hydrocarbon chain,the more probable to be absolutely adsorbed by fine kaolinite particles and then the lower the collector concentration in the bulk,which leds to lower flotation recovery.

  11. 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.

  12. Charging/Discharging Nanomorphology Asymmetry and Rate-Dependent Capacity Degradation in Li-Oxygen Battery.

    Science.gov (United States)

    Kushima, Akihiro; Koido, Tetsuya; Fujiwara, Yoshiya; Kuriyama, Nariaki; Kusumi, Nobuhiro; Li, Ju

    2015-12-01

    Liquid-cell in situ transmission electron microscopy (TEM) observations of the charge/discharge reactions of nonaqueous Li-oxygen battery cathode were performed with ∼5 nm spatial resolution. The discharging reaction occurred at the interface between the electrolyte and the reaction product, whereas in charging, the reactant was decomposed at the contact with the gold current collector, indicating that the lithium ion diffusivity/electronic conductivity is the limiting factor in discharging/charging, respectively, which is a root cause for the asymmetry in discharging/charging overpotential. Detachments of lithium oxide particles from the current collector into the liquid electrolyte are frequently seen when the cell was discharged at high overpotentials, with loss of active materials into liquid electrolyte ("flotsam") under minute liquid flow agitation, as the lithium peroxide dendritic trees are shown to be fragile mechanically and electrically. Our result implies that enhancing the binding force between the reaction products and the current collector to maintain robust electronic conduction is a key for improving the battery performance. This work demonstrated for the first time the in situ TEM observation of a three-phase-reaction involving gold electrode, lithium oxides, DMSO electrolyte and lithium salt, and O2 gas. The technique described in this work is not limited to Li-oxygen battery but also can be potentially used in other applications involving gas/liquid/solid electrochemical reactions. PMID:26535921

  13. CHARGE Association

    Directory of Open Access Journals (Sweden)

    Semanti Chakraborty

    2012-01-01

    Full Text Available We present here a case of 17-year-old boy from Kolkata presenting with obesity, bilateral gynecomastia, mental retardation, and hypogonadotrophic hypogonadism. The patient weighed 70 kg and was of 153 cm height. Facial asymmetry (unilateral facial palsy, gynecomastia, decreased pubic and axillary hair, small penis, decreased right testicular volume, non-palpable left testis, and right-sided congenital inguinal hernia was present. The patient also had disc coloboma, convergent squint, microcornea, microphthalmia, pseudohypertelorism, low set ears, short neck, and choanalatresia. He had h/o VSD repaired with patch. Laboratory examination revealed haemoglobin 9.9 mg/dl, urea 24 mg/dl, creatinine 0.68 mg/dl. IGF1 77.80 ng/ml (decreased for age, GH <0.05 ng/ml, testosterone 0.25 ng/ml, FSH-0.95 ΅IU/ml, LH 0.60 ΅IU/ml. ACTH, 8:00 A.M cortisol, FT3, FT4, TSH, estradiol, DHEA-S, lipid profile, and LFT was within normal limits. Prolactin was elevated at 38.50 ng/ml. The patient′s karyotype was 46XY. Echocardiography revealed ventricularseptal defect closed with patch, grade 1 aortic regurgitation, and ejection fraction 67%. Ultrasound testis showed small right testis within scrotal sac and undescended left testis within left inguinal canal. CT scan paranasal sinuses revealed choanalatresia and deviation of nasal septum to the right. Sonomammography revealed bilateral proliferation of fibroglandular elements predominantly in subareoalar region of breasts. MRI of brain and pituitary region revealed markedly atrophic pituitary gland parenchyma with preserved infundibulum and hypothalamus and widened suprasellar cistern. The CHARGE association is an increasingly recognized non-random pattern of congenital anomalies comprising of coloboma, heart defect, choanal atresia, retarded growth and development, genital hypoplasia, ear abnormalities, and/or deafness. [1] These anomalies have a higher probability of occurring together. In this report, we have

  14. 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

  15. Longevity characteristics of flat solar water-heating collectors in hot-water-supply systems. Part 1. Procedure for calculating collector thermal output

    International Nuclear Information System (INIS)

    A procedure for calculating longevity indices (daily and monthly variations and, hence, annual thermal output) of flat solar water-heating collectors, amount of conditional fuel saved per year by using solar energy, and cost of solar fuel and thermal energy generated in hot-water-supply systems is described. (authors)

  16. MERCURY CONTROL WITH THE ADVANCED HYBRID PARTICULATE COLLECTOR

    International Nuclear Information System (INIS)

    Since 1995, DOE has supported development of a new concept in particulate control, called the advanced hybrid particulate collector (AHPC). The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emission with conventional ESPs, and it solves the problem of reentrainment and re-collection of dust in conventional baghouses. The AHPC appears to have unique advantages for mercury control over baghouses or ESPs as an excellent gas-solid contactor. The objective of the three-task project is to demonstrate 90% total mercury control in the AHPC at a lower cost than current mercury control estimates. The approach includes bench-scale batch testing that ties the new work to previous results and links results with larger-scale pilot testing with real flue gas on a coal-fired combustion system, pilot-scale testing on a coal-fired combustion system with both a pulse-jet baghouse and an AHPC to prove or disprove the research hypotheses, and field demonstration pilot-scale testing at a utility power plant to prove scaleup and demonstrate longer-term mercury control. This project, if successful, will demonstrate at the pilot-scale level a technology that would provide a cost-effective technique to accomplish control of mercury emissions and, at the same time, greatly enhance fine particulate collection efficiency. The technology can be used to retrofit systems currently employing inefficient ESP technology as well as for new construction, thereby providing a solution to a large segment of the U.S. utility industry as well as other industries requiring mercury control

  17. MERCURY CONTROL WITH THE ADVANCED HYBRID PARTICULATE COLLECTOR

    Energy Technology Data Exchange (ETDEWEB)

    Ye Zhuang; Stanley J. Miller; Grant E. Dunham; Michelle R. Olderbak

    2002-02-01

    Since 1995, DOE has supported development of a new concept in particulate control, called the advanced hybrid particulate collector (AHPC). The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emission with conventional ESPs, and it solves the problem of reentrainment and re-collection of dust in conventional baghouses. The AHPC appears to have unique advantages for mercury control over baghouses or ESPs as an excellent gas-solid contactor. The objective of the three-task project is to demonstrate 90% total mercury control in the AHPC at a lower cost than current mercury control estimates. The approach includes bench-scale batch testing that ties the new work to previous results and links results with larger-scale pilot testing with real flue gas on a coal-fired combustion system, pilot-scale testing on a coal-fired combustion system with both a pulse-jet baghouse and an AHPC to prove or disprove the research hypotheses, and field demonstration pilot-scale testing at a utility power plant to prove scaleup and demonstrate longer-term mercury control. This project, if successful, will demonstrate at the pilot-scale level a technology that would provide a cost-effective technique to accomplish control of mercury emissions and, at the same time, greatly enhance fine particulate collection efficiency. The technology can be used to retrofit systems currently employing inefficient ESP technology as well as for new construction, thereby providing a solution to a large segment of the U.S. utility industry as well as other industries requiring mercury control.

  18. Progress of nanofluid application in solar collectors: A review

    International Nuclear Information System (INIS)

    Highlights: • Nanoparticles are more suited and adapt to enhance the performance of solar systems. • Extinction coefficient and refractive index of nanofluids are found higher. • Optimum range of volume fraction for which enhancement in heat transfer coefficient is maximum. • Overall response of specific heat capacity of nanofluids is highly anomalous. - Abstract: In recent times solar energy has attracted the attention of scientists to a great deal. On the surface, there are two reasons for it: primarily, the scientists are interested in it with the intent to innovating new devices and secondly, developing new methods to harness it. Miniaturization of devices and energy efficiency are the major focal domains around which new materials are being worked on. The design of solar system may get some basic changes, if the new materials get applied successfully. Albeit, the nanofluids are a comparatively recent innovation which exhibit enhanced heat absorbing and heat transport ability. This paper intends to reinforce the working of nanofluids applied on solar system in the light of works done earlier; it further also explores the variable performance of the solar-system with and without application of nano-fluids. This work has been segmented into two parts: the first part focuses on presenting the experimental and numerical results for the thermal conductivity, viscosity, specific heat and the heat transfer coefficient reported by several authors. The second part deals with the application of nanofluids on different types of solar systems: solar collectors, photovoltaic systems, and solar thermoelectric and energy storage system. A study of the works earlier done seems to be suggesting that the nanofluids have great potential to enhance the functioning of various thermal systems. The recent results of the application of nanofluids in PV/T systems too have been consolidating. It can be safely assumed further that it might enhance the overall performance of the

  19. Thermal performance of flat plate solar collector using various arrangements of compound honeycomb

    International Nuclear Information System (INIS)

    This paper presents the results of an experimental investigation of the performance of a solar collector outfitted with honeycomb of different arrangements. A complete collector test facility equipped with data acquisition system has been assembled and tested for this purpose. A flat plate solar collector, of 2 m2 area and 60 mm air gap, has been designed and constructed. The adapted honeycomb unit is structured from polycarbonate sheet of 16 mm thickness containing two rows of honeycomb cells with longitudinal aspect ratio of 0.4. The effect of gap thickness above, below or between the honeycomb units is examined using single or double units of honeycomb. Six arrangements of the single honeycomb unit (SHU), with bottom gaps of 0, 3, 8, 14, 22 and 36 mm, are tested. Six other arrangements of double honeycomb units with different top, middle and bottom gaps are investigated. The experimental data along with correlations obtained by linear regression are presented. The effect of gap thickness for the collector fitted with SHU indicates that the bottom gap is crucial with respect to the heat loss coefficient. The arrangement of single honeycomb with bottom gap of 3 mm is the optimum, as it offers the highest efficiency between all the arrangements and the lowest heat loss coefficient among the other honeycomb arrangements. The results for the collector equipped with two honeycomb units reveal less sensitivity of the heat loss coefficients to variations of the top or middle gaps. Comparing the results obtained for single and double honeycomb units revealed that a compound honeycomb solar collector with air gaps of the right thickness above and below the SHU enhances the collector performance considerably. Also, it affords substantial conservation of honeycomb material because its thickness is about 25% of the total air gap

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

    International Nuclear Information System (INIS)

    Highlights: ► A new low temperature desalination process using solar collectors was investigated. ► A thermal energy storage tank (TES) was included for continuous process operation. ► Solar collector area and TES volumes were optimized by theoretical simulations. ► Economic analysis for the entire process was compared with and without TES tank. ► Energy and emission payback periods for the solar collector system were reported. -- Abstract: A low temperature desalination process capable of producing 100 L/d freshwater was designed to utilize solar energy harvested from flat plate solar collectors. Since solar insolation is intermittent, a thermal energy storage system was incorporated to run the desalination process round the clock. The requirements for solar collector area as well as thermal energy storage volume were estimated based on the variations in solar insolation. Results from this theoretical study confirm that thermal energy storage is a useful component of the system for conserving thermal energy to meet the energy demand when direct solar energy resource is not available. Thermodynamic advantages of the low temperature desalination using thermal energy storage, as well as energy and environmental emissions payback period of the system powered by flat plate solar collectors are presented. It has been determined that a solar collector area of 18 m2 with a thermal energy storage volume of 3 m3 is adequate to produce 100 L/d of freshwater round the clock considering fluctuations in the weather conditions. An economic analysis on the desalination system with thermal energy storage is also presented.

  1. Growth of juvenile blue mussels (Mytilus edulis) on suspended collectors in the Dutch Wadden Sea

    Science.gov (United States)

    Jacobs, P.; Beauchemin, C.; Riegman, R.

    2014-01-01

    In The Netherlands, fishing for juvenile blue mussels (Mytilus edulis) on wild beds is gradually replaced by harvesting of seeds from suspended collectors. Both the relaxation of fishing as well as the up-scaling of the number of seed collectors are expected to result in an increase in the number of mussels in the Wadden Sea. Consequently, an enhanced mussel population will cause an additional filtration impact on the system. The question is raised to what extent collectors can be used without negatively affecting the carrying capacity of an ecosystem. Therefore, a monitoring programme was initiated to study the growth of juvenile mussels on suspended collectors. This growth was related to food availability, measured as chlorophyll-a, and temperature both before and after settlement. Findings will serve as input for mathematical models predicting the carrying capacity for mussel seed collectors in this area. The results for 2010 and 2011 are presented. In 2011 settled mussels achieved a higher growth rate, while phytoplankton concentrations after settlement were lower. This contradicts the general agreement that higher phytoplankton concentrations result in higher growth rates. A positive relation between chlorophyll-a concentrations during the larval period and the growth rate of settled mussels was found. The number of settled larvae was higher in 2011. Results from existing studies on settlement and recruitment on tidal flats combined with estimated settlement date in the current study led to the hypothesis that the number of settled mussels on rope collectors is inversely related to the duration of the larval period (determined by water temperature). Our results indicated that in the Wadden Sea, the intra-annual differences in chlorophyll-a and temperature did not have an impact on the juvenile growth rate, while the interannual differences did. This is an indication that the larval stage is strongly discriminative in terms of juvenile growth rates. Modelling

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

    OpenAIRE

    Chii-Dong Ho; Ho-Ming Yeh

    2012-01-01

    The collector efficiency in a downward-type double-pass external-recycle solar air heater with fins attached on the absorbing plate has been investigated theoretically. Considerable improvement in collector efficiency is obtainable if the collector is equipped with fins and the operation is carried out with an external recycle. Due to the recycling, the desirable effect of increasing the heat transfer coefficient compensates for the undesirable effect of decreasing the driving force (temperat...

  3. 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

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

    OpenAIRE

    Denysova A.E.; Mazurenko A.S.; Denysova A.S.

    2015-01-01

    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 ...

  5. Modified mathematical model for evaluating the performance of water-in-glass evacuated tube solar collector considering tube shading effect

    International Nuclear Information System (INIS)

    The aim of this paper is to introduce a procedure for simulating the absorbed solar radiation and heat transfer process in water-in-glass evacuated tube solar collectors. The procedure is developed to calculate the daily utilized solar energy and outlet collector temperature for different tilt angles, collector azimuth angles and geometric parameters without requirement for any experimental factor determination. Total absorbed solar radiation is evaluated by integrating the flat-plate solar collector performance equations over the tube circumference taking into account the shading of the adjacent tubes and variance of transmissivity–absorptivity product with the incidence angle of radiation. The heat transfer into the collector fluid is evaluated by subtracting the heat loss from the total absorbed solar radiation. Comparison between calculated and measured tank temperature shows a good agreement between them under different heating loads. Performance of solar collector at different tilt angles, collector Azimuth angles, tubes spacing and collector mass flow rate is investigated theoretically. In Egypt (30° Latitude angle), the results show that 10°, 30° and 45° are the optimum solar collector tilt angles during the summer, vernal and autumnal equinox and winter operation respectively. Also, the utilized solar energy increases about 2.8% when the mass flow rate increases 100%, and the solar collector with south-facing has the best performance except for vertical tube solar collector. The simulation results also show that solar collector with wide tube spacing reduce the shading effect and hence increase the absorbed radiation. The final tank temperature as a function of collector's mass flow rate for three different days; 21 March, 21 June and 21 December is also investigated. The total incidence radiation, absorbed solar radiation and utilized heat per tube are presented for the three optimum tilt angles 10°, 30° and 45°. Efficiency curve of water

  6. Numerical and experimental analysis of a point focus solar collector using high concentration imaging PMMA Fresnel lens

    International Nuclear Information System (INIS)

    Research highlights: → We studied a point focus Fresnel solar collector using different cavity receivers. → The collector heat removal factors are derived to find the optimal cavity shape. → Numerical and experimental analysis shows that the conical cavity is optimum. -- Abstract: A high concentration imaging Fresnel solar collector provided with different cavity receivers was developed and its behavior was investigated. Round copper pipes winded into different spring shapes were used as receiver by placing in the cylindrical cavity to absorb concentrated solar energy and transfer it to a heat transfer fluid (HTF). The collector efficiency factor and collector heat removal factor were derived for the cavity receivers to find out heat transfer mechanism and to propose an effective way for evaluating the performance of Fresnel solar collector and determining the optimal cavity structure. The problem of Fresnel solar collector with synthetic heat transfer oil flow was simulated and analyzed to investigate heat loss from different cavity receivers. Solar irradiation as well as convection and heat transfer in the circulating fluid and between the internal surfaces of the cavity and the environment are considered in the model. The temperature distribution over its area as well as the collector thermal efficiency at nominal flow rate was used in order to validate the simulation results. It was found that the simulated temperature distribution during operation and the average collector efficiency are in good agreement with the experimental data. Finally, the optimal shape of solar cavity receiver, as well as its thermal performance, are deeply analyzed and discussed.

  7. The optimization of a solar collector of the Fiat-Thin box type with a fixed reflector

    OpenAIRE

    Trung, Ha Dang; Quan, Nguyen

    2015-01-01

    A new design of solar collector has been investigated which uses a reflector of the fixed type. Both collector and mirror are of the non-tracking type, so the absorbed solar energy depends on the incident angle of the solar beam and the collector-mirror arrangement. A high water temperature and a maximum in the absorbed radiation can be reached by selecting an optimal dimension ratio for the collector and reflector. The research has shown that reasonable dimension ratio of 1.7 to 3 can result...

  8. Validation of a dynamic model for unglazed collectors including condensation. Application for standardized testing and simulation in TRNSYS and IDA

    DEFF Research Database (Denmark)

    Perers, Bengt; Kovacs, Peter; Pettersson, Ulrik;

    2011-01-01

    An improved unglazed collector model has been validated for use in TRNSYS and IDA and also for future extension of the EN12975 collector test standard. The basic model is the same as used in the EN12975 test standard in the quasi dynamic performance test method (QDT). In this case with the addition...... collector testing and system simulation by using the same dynamic model and parameters during testing and simulation. The model together with the parameters will be validated in each test in this way. This work describes the method applied to an unglazed collector operating partly below the dew point under...

  9. Workplace Charging. Charging Up University Campuses

    Energy Technology Data Exchange (ETDEWEB)

    Giles, Carrie [ICF International, Fairfax, VA (United States); Ryder, Carrie [ICF International, Fairfax, VA (United States); Lommele, Stephen [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-03-01

    This case study features the experiences of university partners in the U.S. Department of Energy's (DOE) Workplace Charging Challenge with the installation and management of plug-in electric vehicle (PEV) charging stations.

  10. An Optical Characterization Technique for Parabolic Trough Solar Collectors Using Images of the Absorber Reflection

    Science.gov (United States)

    Owkes, Jeanmarie Kathleen

    As the concentrating solar power industry competes to develop a less-expensive parabolic trough collector, assurance is needed that new parabolic trough collectors maintain accurate optical alignment. Previous optical characterization techniques are either too slow, ill-suited for field testing, or do not allow the collector to be tested in realistic orientations. The Observer method presented here enables the rapid optical characterization of parabolic trough collectors in any orientation in the field. The Observer method directly measures the combined optical angular errors in the reflector surface shape and the absorber position, which can be separated into its two components: reflector surface slope and absorber misalignment. The data acquisition requires the placement of photogrammetry targets on and around the collector. Multiple photographs of the absorber and its reflection are taken with a digital camera from different angles with respect to the collector. The images are processed to determine the camera location of each image using photogrammetry bundle analysis. The absorber and its reflection are found in the photographs using image-processing techniques. A Monte Carlo uncertainty model was developed to determine the uncertainty in the Observer measurements. The uncertainty was estimated for a wide array of measurement test scenarios to demonstrate the user's control over the measurement uncertainty. To validate the Observer method, the absorber alignment technique was compared to traditional photogrammetry; the absorber position measured with the two methods compared with a root-mean-square difference of 1.5 mm in the transverse direction and 0.86 mm along the optical axis. The reflector surface slope error measurement was compared to both VSHOT and SOFAST, two well-established optical characterization tools, by measuring a single reflector panel in the laboratory. The VSHOT and SOFAST measurements agreed with the Observer with a root

  11. Laser Post-Ionization Mass Spectrometry Analysis of Genesis Solar Wind Collectors

    Science.gov (United States)

    Veryovkin, I. V.; Tripa, C. E.; Zinovev, A. V.; Hiller, J. M.; Pellin, M. J.; Burnett, D. S.

    2008-12-01

    The samples returned to Earth by the NASA's Genesis Mission contain a record of the elemental and isotopic abundances of the Solar Wind (SW). This record is formed by the SW ions implanted in the near-surface regions of the Genesis sample collectors, so that the SW material can be distinguished from a terrestrial contamination, which occurred due to the crash landing of the spacecraft Sample Return Capsule. At Argonne National Laboratory, we are conducting analyzes of the Genesis SW collectors using a specially developed Laser Post-Ionization Secondary Neutral Mass Spectrometer (LPI SNMS), SARISA. This approach, based on ion sputtering of a SW collector surface and laser post-ionization of the neutral atoms sputtered from it, has proved to be sensitive, accurate and well suited for the quantitative analysis of the Genesis samples. We will report in this work the abundances of SW Mg and Ca measured with SARISA in two types of SW collector materials, silicon and diamond-like carbon (DLC). These LPI SNMS measurements were conducted in Resonance-Enhanced Multi-Photon Ionization (REMPI) regime using a sputter depth profiling method. In order to make our analyzes quantitative, we used specially prepared standards, made from exactly the same materials as the flown Genesis SW collectors and implanted with known fluencies of Mg and Ca ions. The REMPI analyzes of these standards allowed us to characterize the actual efficiency and detection limits of the SARISA instrument: for Mg, its useful yield peaked at about 20% and detection limits corresponded to SNMS measurements, we conducted a special series of experiments with sputter depth profiling of Genesis SW collectors from their backside (i.e. opposite to the one exposed to the SW). By these measurements, we have demonstrated that (1) the implanted solar wind can be identified by backside sputter depth profiling, (2) the apparent widening of depth profiles into the bulk of SW collectors is mostly due to ion mixing effects

  12. Experimental investigation and analysis on a concentrating solar collector using linear Fresnel lens

    International Nuclear Information System (INIS)

    A concentrating solar collector based on linear Fresnel lens is investigated experimentally in this paper. This solar collector is expected to acquire a higher thermal efficiency at a relatively high temperature level than the commonly used flat-plate or evacuated tube solar collectors. Experimental results show that the thermal efficiency is about 50% when the conversion temperature (water) is 90 deg. C. The test shows that the indication of lost energy is 0.578 W/m2 K, which is much smaller than that of commonly used evacuated tube solar collector without concentrating. In order to make analysis, a mathematical model for evacuated tube absorber heated by linear Fresnel lens has been built. The validation shows that the model agrees with the experimental data well. The analysis indicates that Fresnel lens collector with evacuated tube absorber has good efficiency (50%) in clear day even when the conversion temperature approaches 200 deg. C. The influence of ambient conditions and the percent of different types of energy loss, etc., are also analyzed.

  13. 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.

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

    CERN Document Server

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

    2001-01-01

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

  15. Energy analysis and improvement potential of finned double-pass solar collector

    International Nuclear Information System (INIS)

    Highlights: • The developed steady state model predicting the thermal performance of double-pass solar collectors is presented. • The main objective of this paper is to analyze the energy and exergy of finned double-pass solar collector. • A new mathematical model, solution procedure, and test results are presented. • The thermal performances and improvement potential of the double-pass solar collectors are discussed. - Abstract: Steady state energy balance equations for the finned double-pass solar collector have been developed. These equations were solved using the matrix inversion method. The predicted results were in agreement with the results obtained from the experiments. The predictions and experiments were observed at the mass flow rate ranging between 0.03 kg/s and 0.1 kg/s, and solar radiation ranging between 400 W/m2 and 800 W/m2. The effects of mass flow rates and solar radiation levels on energy efficiency, exergy efficiency and the improvement potential have been observed. The optimum energy efficiency is approximately 77%, which was observed at the mass flow rate of 0.09 kg/s. The optical efficiency of the finned double-pass solar collector is approximately 70–80%. The exergy efficiency is approximately 15–28% and improvement potential of 740–1070 W for a solar radiation of 425–790 W/m2

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

    International Nuclear Information System (INIS)

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

  17. 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.

  18. Design improvements for a collector/generator/adsorber of a solid adsorption solar refrigerator

    Energy Technology Data Exchange (ETDEWEB)

    Ogueke, N.V.; Anyanwu, E.E. [Mechanical Engineering Department, Federal University of Technology, P.M.B. 1526, Owerri (Nigeria)

    2008-11-15

    A study of the effects of different collector design parameters on the performances of a solar powered solid adsorption refrigerator is presented. The refrigerator uses activated carbon/methanol as the adsorbent/refrigerant pair. The study was undertaken using a computer simulation program developed from a transient analysis of the system. The parameters tested are the collector plate emissivity/absorptivity combination, adsorbent packing density, tube spacing, outer tube outside diameter, adsorbent thermal conductivity, heat transfer coefficient at adsorbent/tube interface, and adsorbent tube/collector plate materials combination. Two performance indicators namely, condensate yield and coefficient of performance (COP) were used in the study as figures of merit. A multiple regression technique was used to correlate the performance indicators with the collector parameters through a quadratic relation. Consequently an objective function, suitable for selecting optimal values of the parameters is defined, subject to specified constraints. Selecting the COP as the preferred indicator parameter, optimization was then carried out. Improvements in the ranges of 29-38% for COP and 26-35% for condensate yield were obtained with optimal choices of tube spacing, adsorbent packing density and collector plate/adsorbent tube material combinations. (author)

  19. 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.

  20. Simulation of solar lithium bromide-water absorption cooling system with parabolic trough collector

    International Nuclear Information System (INIS)

    Ahwaz is one of the sweltering cities in Iran where an enormous amount of energy is being consumed to cool residential places in a year. The aim of this research is to simulate a solar single effect lithium bromide-water absorption cooling system in Ahwaz. The solar energy is absorbed by a horizontal N-S parabolic trough collector and stored in an insulated thermal storage tank. The system has been designed to supply the cooling load of a typical house where the cooling load peak is about 17.5 kW (5 tons of refrigeration), which occurs in July. A thermodynamic model has been used to simulate the absorption cycle. The working fluid is water, which is pumped directly to the collector. The results showed 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 57.6 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

  1. Adsorption of guanidinium collectors on aluminosilicate minerals - a density functional study.

    Science.gov (United States)

    Nulakani, Naga Venkateswara Rao; Baskar, Prathab; Patra, Abhay Shankar; Subramanian, Venkatesan

    2015-10-01

    In this density functional theory based investigation, we have modelled and studied the adsorption behaviour of guanidinium cations and substituted (phenyl, methoxy phenyl, nitro phenyl and di-nitro phenyl) guanidinium cationic collectors on the basal surfaces of kaolinite and goethite. The adsorption behaviour is assessed in three different media, such as gas, explicit water and pH medium, to understand the affinity of GC collectors to the SiO4 tetrahedral and AlO6 octahedral surfaces of kaolinite. The tetrahedral siloxane surface possesses a larger binding affinity to GC collectors than the octahedral sites due to the presence of surface exposed oxygen atoms that are active in the intermolecular interactions. Furthermore, the inductive electronic effects of substituted guanidinium cations also play a key role in the adsorption mechanism. Highly positive cations result in a stronger electrostatic interaction and preferential adsorption with the kaolinite surfaces than low positive cations. Computed interaction energies and electron densities at the bond critical points suggest that the adsorption of guanidinium cations on the surfaces of kaolinite and goethite is due to the formation of intra/inter hydrogen bonding networks. Also, the electrostatic interaction favours the high adsorption ability of GC collectors in the pH medium than gas phase and water medium. The structures and energies of GC collectors pave an intuitive view for future experimental studies on mineral flotation. PMID:26303845

  2. Effect of three typical sulfide mineral flotation collectors on soil microbial activity.

    Science.gov (United States)

    Guo, Zunwei; Yao, Jun; Wang, Fei; Yuan, Zhimin; Bararunyeretse, P; Zhao, Yue

    2016-04-01

    The sulfide mineral flotation collectors are wildly used in China, whereas their toxic effect on soil microbial activity remains largely unexplored. In this study, isothermal microcalorimetric technique and soil enzyme assay techniques were employed to investigate the toxic effect of typical sulfide mineral flotation collectors on soil microbial activity. Soil samples were treated with different concentrations (0-100 μg•g - 1 soil) of butyl xanthate, butyl dithiophosphate, and sodium diethyldithiocarbamate. Results showed a significant adverse effect of butyl xanthate (p flotation collectors concentration from 20.0 to 100.0 μg•g(-1). However, the adverse effects of these three floatation collectors showed significant difference. The IC 20 of the investigated flotation reagents followed such an order: IC 20 (butyl xanthate) > IC 20 (sodium diethyldithiocarbamate) > IC 20 (butyl dithiophosphate) with their respective inhibitory concentration as 47.03, 38.36, and 33.34 μg•g(-1). Besides, soil enzyme activities revealed that these three flotation collectors had an obvious effect on fluorescein diacetate hydrolysis (FDA) enzyme and catalase (CAT) enzyme. The proposed methods can provide meaningful toxicological information of flotation reagents to soil microbes in the view of metabolism and biochemistry, which are consistent and correlated to each other. PMID:26695417

  3. Development of a composite collector scheme for flotation of chalcopyrite ore

    International Nuclear Information System (INIS)

    Xanthate-type collectors reported for the upgradation of Chalcopyrite ore of North Waziristan area were studied and a new technique was developed, in which -two collectors were used (composite collectors) in the bulk-stage process of froth-flotation to achieve metallurgical grade with maximum recovery. The collectors studied were thiol-type surfactants, such as sodium ethyl xanthate (NaEX), sodium propyl xanthate (NaPX), sodium butyl xanthate (NaBX) and sodium Amyl xanthate (NaAX). Mixed collectors examined were in the varying dosage ratio of (0-100:100-0) through the combination of(i) sodium ethyl xanthate with sodium propyl xanthate, sodium ethyl xanthate with sodium butyl xanthate, sodium ethyl xanthate with sodium amyl xanthate, (ii) sodium propyl xanthate with sodium butyl xanthate, sodium propyl xanthate with sodium amyl xanthate and (iii) sodium butyl xanthate with sodium amyl xanthate. All the remaining flotation parameters were kept constant during the various flotation tests. The results were compared and the conclusions were drawn that the optimum grade in the concentrate was obtained with a mixture having a ratio of 4: 1 with sodium ethyl xanthate and sodium butyl xanthate. Recovery of copper content in the concentrate was achieved with ratio of 2:3 with sodium butyl xanthate and sodium amyl xanthate. (author)

  4. MERCURY CONTROL WITH THE ADVANCED HYBRID PARTICULATE COLLECTOR

    International Nuclear Information System (INIS)

    This project was awarded under U.S. Department of Energy (DOE) Program Solicitation DE-PS26-00NT40769 and specifically addresses Technical Topical Area 4-Testing Novel and Less Mature Control Technologies on Actual Flue Gas at the Pilot-Scale. The project team will include the Energy and Environmental Research Center (EERC) as the main contractor, W.L. Gore and Associates, Inc., as a technical and financial partner, and the Big Stone Power Plant operated by Otter Tail Power Company, which will host the field testing portion of the research. Since 1995, DOE has supported development of a new concept in particulate control, called the advanced hybrid particulate collector (AHPC). The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emission with conventional ESPs, and it solves the problem of reentrainment and re-collection of dust in conventional baghouses. The AHPC appears to have unique advantages for mercury control over baghouses or ESPs as an excellent gas-solid contactor. The objective of the three-task project is to demonstrate 90% total mercury control in the AHPC at a lower cost than current mercury control estimates. The approach includes bench-scale batch testing that ties the new work to previous results and links results with larger-scale pilot testing with real flue gas on a coal-fired combustion system, pilot-scale testing on a coal-fired combustion system with both a pulse-jet baghouse and an AHPC to prove or disprove the research hypotheses, and field demonstration pilot-scale testing at a utility power plant to prove scaleup and demonstrate longer-term mercury control. This project, if successful, will demonstrate at the pilot-scale level a

  5. MERCURY CONTROL WITH THE ADVANCED HYBRID PARTICULATE COLLECTOR

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-11-01

    This project was awarded under U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) Program Solicitation DE-PS26-00NT40769 and specifically addresses Technical Topical Area 4-Testing Novel and Less Mature Control Technologies on Actual Flue Gas at the Pilot Scale. The project team includes the Energy & Environmental Research Center (EERC) as the main contractor; W.L. Gore & Associates, Inc., as a technical and financial partner; and the Big Stone Power Plant operated by Otter Tail Power Company, host for the field-testing portion of the research. Since 1995, DOE has supported development of a new concept in particulate control called the advanced hybrid particulate collector (AHPC). The AHPC has been licensed to W.L. Gore & Associates, Inc., and is now marketed as the ADVANCED HYBRID{trademark} Filter by Gore. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and it solves the problem of reentrainment and re-collection of dust in conventional baghouses. The AHPC appears to have unique advantages for mercury control over baghouses or ESPs as an excellent gas-solid contactor. The objective of the three-task project is to demonstrate 90% total mercury control in the AHPC at a lower cost than current mercury control estimates. The approach includes bench-scale batch testing that ties the new work to previous results and links results with larger-scale pilot testing with real flue gas on a coal-fired combustion system, pilot-scale testing on a coal-fired combustion system with both a pulse-jet baghouse and an AHPC to prove or disprove the research hypotheses, and field demonstration pilot-scale testing at a

  6. MERCURY CONTROL WITH THE ADVANCED HYBRID PARTICULATE COLLECTOR

    Energy Technology Data Exchange (ETDEWEB)

    Ye Zhuang; Stanley J. Miller; Steven A. Benson; Michelle R. Olderbak

    2003-08-01

    This project was awarded under U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) Program Solicitation DE-PS26-00NT40769 and specifically addresses Technical Topical Area 4-Testing Novel and Less Mature Control Technologies on Actual Flue Gas at the Pilot Scale. The project team includes the Energy & Environmental Research Center (EERC) as the main contractor; W.L. Gore & Associates, Inc., as a technical and financial partner; and the Big Stone Plant operated by Otter Tail Power Company, host for the field-testing portion of the research. Since 1995, DOE has supported development of a new concept in particulate control called the advanced hybrid particulate collector (AHPC). The AHPC has been licensed to W.L. Gore & Associates, Inc., and is now marketed as the ''Advanced Hybrid''{trademark} filter by Gore. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The AHPC provides ultra-high collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and it solves the problem of reentrainment and re-collection of dust in conventional baghouses. The AHPC appears to have unique advantages for mercury control over baghouses or ESPs as an excellent gas-solid contactor. The objective of the three-task project is to demonstrate 90% total mercury control in the AHPC at a lower cost than current mercury control estimates. The approach includes bench-scale batch testing that ties the new work to previous results and links results with larger-scale pilot testing with real flue gas on a coal-fired combustion system, pilot-scale testing on a coal-fired combustion system with both a pulse-jet baghouse and an AHPC to prove or disprove the research hypotheses, and field demonstration pilot

  7. Verification of computer-aided designs of traveling-wave tubes utilizing novel dynamic refocusers and graphite electrodes for the multistage depressed collector

    Science.gov (United States)

    Ramins, P.; Kosmahl, H. G.; Force, D. A.; Palmer, R. W.; Dayton, J. A., Jr.

    1985-01-01

    A computational procedure for the design of TWT-refocuser-MDC systems was used to design a short dynamic refocusing system and highly efficient four-stage depressed collector for a 200-W, 8- to 18-GHz, TWT. The computations were carried out with advanced, multidimensional computer programs which model the electron beam as a series of disks of charge and follow their trajectories from the RF input of the TWT, through the slow-wave structure and refocusing section, to their points of impact in the depressed collector. Secondary emission losses in the MDC were treated semi-quantitatively by injecting a representative beam of secondary electrons into the MDC analysis at the point of impact of each primary beam. A comparison of computed and measured TWT and MDC performance showed very good agreement. The electrodes of the MDC were fabricated from a particular form of isotropic graphite that was selected for its low secondary electron yield, ease of machinability, and vacuum properties. This MDC was tested (at CW) for more than 1000 hr with negligible degradation in TWT and MDC performances.

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

    International Nuclear Information System (INIS)

    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.

  9. Thin Flexible Lithium Ion Battery Featuring Graphite Paper Based Current Collectors with Enhanced Conductivity

    CERN Document Server

    Qu, Hang; Tang, Yufeng; Semenikihin, Oleg; Skorobogatiy, Maksim

    2015-01-01

    A flexible, light weight and high conductivity current collector is the key element that enables fabrication of high performance flexible lithium ion battery. Here we report a thin, light weight and flexible lithium ion battery that uses graphite paper enhanced with a nano-sized metallic layers as the current collector, LiFePO4 and Li4Ti5O12 as the cathode and anode materials, and PE membrane soaked in LiPF6 as a separator. Using thin and flexible graphite paper as a substrate for the current collector instead of a rigid and heavy metal foil enables us to demonstrate a very thin Lithium-Ion Battery into ultra-thin (total thickness including encapsulation layers of less than 250 {\\mu}m) that is also light weight and highly flexible.

  10. 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.

  11. 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.

  12. Effects of nanometric hydrophobic layer on performances of solar photovoltaic collectors

    Directory of Open Access Journals (Sweden)

    Andrei BUTUZA

    2014-11-01

    Full Text Available The study refers to the experimental investigation of solar photovoltaic collectors' behaviour when the glazed surface is treated with a nanometric layer of hydrophobic solution. The experiment was carried out on two photovoltaic collectors, of which one was considered as reference and the other one was coated with a commercial hydrophobic solution. It was studied the evolution of the following electrical parameters: current, voltage, power, efficiency and daily energy production. The voltage was almost unaffected, but for all the others parameters, important drop were recorded. The preliminary conclusion of the study is that the use of hydrophobic solutions, for the treatment of glazed surfaces of solar collectors is not recommended. This hypothesis needs supplementary investigations and measurements in the context of reduced available information concerning the optical properties of hydrophobic solutions.

  13. Performance study of unglazed cylindrical solar collector for adsorption refrigeration system

    Science.gov (United States)

    Mahesh, A.; Kaushik, S. C.; Kumaraguru, A. K.

    2013-12-01

    In the present communication, the unglazed cylindrical solar adsorber module is suggested for refrigeration and theoretical models for the heat and mass transfer in the cylindrical adsorber with heat balance equations in the collector components have been developed. It has been found that, both the SCP and COPsolar raises with increasing the evaporation temperature and drop off with the increase of the condensation temperature. The COPsolar increased from 0.15 to 0.52 with the increase of the total solar energy absorbed by the collector while the COPcycle varied in the range of 0.57-0.73. The efficiency of unglazed solar collector varied from 36 to 44 %. The cost of current unglazed adsorption refrigeration system is compared with the glazed system, and it is 33 to 50 % less than the cost of glazed system.

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

    International Nuclear Information System (INIS)

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

  15. Large area focusing collector for the observation of cosmic X rays.

    Science.gov (United States)

    Gorenstein, P.; Decaprio, A.; Chase, R.; Harris, B.

    1973-01-01

    A large area focusing X-ray collector constructed for a sounding rocket is described. The instrument consists of nested reflecting plates that are curved slightly in one dimension to form a set of parabolas with a common focus. An array of plates such as the one in the sounding rocket focuses a parallel beam of X-rays to a line. The reflecting surfaces are commercial float glass with an evaporated metallic coating such as gold or nickel. With a gold coating, the effective area of the rocket collector is about 250 sq cm for 0.3 keV X rays and about 150 sq cm at 1.2 keV. Its angular resolution is a few arc minutes and field of view is about plus or minus .75 deg (full width at half maximum). The collector performed successfully during a sounding rocket flight.

  16. Model of a Solar Collector/Storage System for Industrial Thermal Applications

    Directory of Open Access Journals (Sweden)

    Duccio Tempesti

    2009-06-01

    Full Text Available

    A model for the thermodynamic analysis of a non-stationary solar thermal system is described. The main system components are a parabolic tube collector and a steam accumulator, which provides heat for industrial processes. The use of exergy analysis leads to the identification of potentials for performance improvements. The rate of exergy destruction is calculated over a daily operation cycle, showing that the largest exergy destruction takes place at collector level. The effect of varying the volumetric flow rate per unit collector surface area is also discussed.

    • This paper is an updated version of a paper published in the ECOS'08 proceedings. 

  17. Experiences and lessons learned from 30 years of dynamic collector testing, modelling and simulation

    DEFF Research Database (Denmark)

    Perers, Bengt; Kovacs, Peter; Pettersson, Ulrik

    2011-01-01

    Dynamic testing and modeling (in contrast to Steady State line of action) of solar collectors is to prefer in most climates, except for the most extreme locations with clear skies every day. A very important part of dynamic testing and modeling is not only the thermal capacitance correction...... concerning solar radiation measurements for beam and diffuse including alignment of sensors and test object, that are often not considered, which will be discussed and lessons learned will be given. A misalignment of just a few degrees of the collector test stand or the solar sensors will immediately show up...... in a dynamic test evaluation, especially when analyzing the incidence angle modifier behavior and thermal capacitance of a collector. To achieve good results in dynamic testing it is essential to understand the basic concepts of the method and to use this understanding when designing a test rig and collecting...

  18. Performance simulation of serpentine type metallic and non-metallic solar collector

    International Nuclear Information System (INIS)

    This paper presents a theoretical investigation of metallic and non-metalic solar water collector models for evaluating its performane parameters. The determined parameters include heat removal factor , overall heat loss coefficients, heat gain, daily and hourly efficiencies. The present study reports that, under forced circulation lest, the non-metallic collector has an inferior performance parameters when compared to that of the metallic one. It was also revealed that the overall heat loss coefficients of both collectors show weak dependence on the flow rate variations. It was also noticed that the heat removal factor forboth models is more sensitive to the flow rate variations. Also noticed that the heat removal factor for both models is more sensitive to the flow rate variations. Also, a comparision of performance parameters of the theoretical and experimental studies showed good agreements for most hours of the day, except the results obtained at the early morning and late after noon hours.(Author)

  19. Concrete and abstract thinking styles and art preferences in a sample of serious art collectors.

    Science.gov (United States)

    Gridley, Mark C

    2006-06-01

    59 art collectors (30 men, 29 women) were given the Gregorc Style Delineator to classify them by thinking styles and a questionnaire regarding their art preferences. Their ages ranged from 33 to 99 years (M=59.5 yr.). Abstract art was preferred by 34% of the sample. Representational art, such as Dutch Masters and Impressionism, was preferred by 66% of the sample. Of the collectors who preferred nonobjective abstract paintings, such as works by color field artists like Mark Rothko, and Abstract Expressionist paintings, such as works by Jackson Pollock, 62% had scores on the Gregorc Style Delineator by which they were classified as showing abstract thinking styles. Of the collectors who preferred representational painting, 86% were classified as showing concrete thinking styles. PMID:16933684

  20. Method of evaluation of solar collector cost under fuel price change

    International Nuclear Information System (INIS)

    When we take into account the problems of large-scale use of solar energy, the matters of economic perspectives of solar plants in the future become vital. We present the method on whose basis evaluation of the cost of solar collectors is performed taking into account the change in the fuel prices. The method is based on the approach to evaluation of the cost of energy generated by the solar plants offered previously by the authors. Assuming that the components of expenditures for production are not changed, we obtained that the cost of solar collectors will grow, at approximately the same ratio as the growth of the prices for fuel (energy). Thus, the problem of creation of the economically effective solar collectors should be solved already today, at the existing prices for materials and fuel. At present, it is assumed that competitiveness of the solar plants will increase with the growth of the fuel prices. (authors)

  1. Ion flotation of uranium contained in industrial phosphoric acid with collector recycling

    International Nuclear Information System (INIS)

    Uranium has been recovered from wet-process phosphoric acid (30% P2O5) by ion flotation with an anionic organophosphorous collector. Recoveries greater than 90% were obtained even at temperatures of about 60 C, the uranium concentrate, which was collected in the froth as a precipitate, containing 7 to 10% U. Collector consumption without recycling of the surface-active reagent was about 12 kg/kg U. Much of the reagent, however, can be recovered for recycling by attack with sodium hydroxide on the floated phase after filtration. This enables a precipitate containing about 30% U to be produced and decreases collector consumption to about 3 kg/kg U. The results were obtained in laboratory-scale experiments on industrial wet-process acid. (author)

  2. A study of collector filter for radioactive gas and dust in high altitude air

    International Nuclear Information System (INIS)

    The collector filter for radioactive gas (gaseous radioiodine) and dust in high altitude air was manufactured on trial and its fundamental performances were studied. The newly designed filter is composed of the electret filter to collect air suspended dust and the fibrous activated carbon filter to collect gaseous iodine. By the tests of the collector filter, it was shown that gaseous iodine was effectively collected, even though there are some restrictions for using this filter system in high altitude air. Also the collection performance of the collector filter for air suspended dust was almost the same as that of current filter paper, thus data for air suspended dust obtained by this system are comparable to those obtained by the current filter paper system. (author)

  3. 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.

  4. 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.

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

  6. Thermodynamic model to study a solar collector for its application to Stirling engines

    International Nuclear Information System (INIS)

    Highlights: • A thermodynamic model is presented to study a solar collector for its application to Stirling engines. • The parabolic collector is analyzed based on optical and thermal. • Effects of changing some conditions and parameters are studied. - Abstract: Energy production through clean and green sources has been paid attention over the last decades owing to high energy consumption and environmental emission. Solar energy is one of the most useful energy sources. Due to high investment cost of centralized generation of electricity and considerable loss in the network, it is necessary to look forward to decentralized electricity generation technologies. Stirling engines have high efficiency and are able to be coupled with solar energy which cannot be applied in internal combustion engines. Solar Stirling engines can be commercialized and used to generate decentralized electricity in small to medium levels. One of the most important steps to set up an efficient solar Stirling engine is choosing and designing the collector. In this study, a solar parabolic collector with 3500 W of power for its application to Stirling engines was designed and analyzed (It is the thermal inlet power for a Stirling engine). We studied the parabolic collector based on optical and thermal analysis. In this case, solar energy is focused by a concentrating mirror and transferred to a pipe containing fluid. MATLAB software was used for obtaining the parameters of the collector, with respect to the geographic, temporal, and environmental conditions, fluid inlet temperature and some other considerations. After obtaining the results of the design, we studied the effects of changing some conditions and parameters such as annular space pressure, type of the gas, wind velocity, environment temperature and absorber pipe coating

  7. Clean Assembly of Genesis Collector Canister for Flight: Lessons for Planetary Sample Return

    Science.gov (United States)

    Allton, J. H.; Stansbery, E. K.; Allen, C. C.; Warren, J. L.; Schwartz, C. M.

    2007-01-01

    Measurement of solar composition in the Genesis collectors requires not only high sensitivity but very low blanks; thus, very strict collector contamination minimization was required beginning with mission planning and continuing through hardware design, fabrication, assembly and testing. Genesis started with clean collectors and kept them clean inside of a canister. The mounting hardware and container for the clean collectors were designed to be cleanable, with access to all surfaces for cleaning. Major structural components were made of aluminum and cleaned with megasonically energized ultrapure water (UPW). The UPW purity was >18 M resistivity. Although aluminum is relatively difficult to clean, the Genesis protocol achieved level 25 and level 50 cleanliness on large structural parts; however, the experience suggests that surface treatments may be helpful on future missions. All cleaning was performed in an ISO Class 4 (Class 10) cleanroom immediately adjacent to an ISO Class 4 assembly room; thus, no plastic packaging was required for transport. Persons assembling the canister were totally enclosed in cleanroom suits with face shield and HEPA filter exhaust from suit. Interior canister materials, including fasteners, were installed, untouched by gloves, using tweezers and other stainless steel tools. Sealants/lubricants were not exposed inside the canister, but vented to the exterior and applied in extremely small amounts using special tools. The canister was closed in ISO Class 4, not to be opened until on station at Earth-Sun L1. Throughout the cleaning and assembly, coupons of reference materials that were cleaned at the same time as the flight hardware were archived for future reference and blanks. Likewise reference collectors were archived. Post-mission analysis of collectors has made use of these archived reference materials.

  8. Measurements of 222Rn and220Rn with a large size collector of radon progeny

    International Nuclear Information System (INIS)

    People have paid more attention to radon since 1980s. Radon concentrations in high background radiation areas in the south are higher than others in China, especially 220 Rn concentration is significantly high. Therefore, measurement of 222 Rn and 220 Rn concentration should be carried out there. I will introduce a large size collector of radon progeny and its applications in this paper. The collector is a sheet of polyvinyl chloride fibre with electrostatics of -500V ∼ -700V. Its size (60mm in diameter) is larger than others (26mm in diameter) that work as the same principle. The collector is more effective to adsorb radon progeny than most of others. The equipment of ZnS(Ag) Scintillation Counting System is available for large size collectors to detect radon progeny. Therefore its sensitivity of measurement is high than others. According to the different half life of radon progeny and based on both theory and experiment, a formula for discrimination and calculation of 222 Rn and 220 Rn concentrations was deduced. The 222 Rn and 220 Rn concentrations were surveyed with electrostatic collectors of radon progeny on the campus of commercial school and some other areas in Hainan, southern China. Neither 222 Rn nor 220 Rn concentrations were found significant high. However several faults underground were delineated. The collector is also used to study radon transportation. Results indicate that radon changes regularly with date when it has transported for a certain distance. Velocities of radon migration in the four media are quite different. Radon migrates more quickly in vertical tube than in the horizontal tube

  9. Measurements of 222Rn and 220Rn with a Large Size Collector of Radon Progeny

    Institute of Scientific and Technical Information of China (English)

    Wu Qifan; Jia Wenyi; Fang Fang; Wang Jun; Cheng Jianping; Liu Guilin; Zhu Li

    2003-01-01

    Radon concentrations in high background radiation areas in the south are higher than those of others in China, especially 220Rn concentration is significantly high. Therefore, measurements of 222Rn and 220 Rn concentrations should be carried out there. This paper introduces a large size collector of radon progeny and its applications. The collector is a sheet of polyvinyl chloride fiber with electrostatics of (-500 V) - ( -700 V). Its size (60 mm in diameter) is larger than those of others (26 mm in diameter) that work with the same principle. The collector is more effective to adsorb radon progeny than most of others. The equipment of ZnS(Ag) Scintillation Counting System is available for large size collectors to detect radon progeny. Therefore, its sensitivity of measurement is higher than that of others.According to the different half lives of radon progeny, and based on both theory and experiments, a formula for discrimination and calculation of 222 Rn and 220Rn concentrations is deduced. The 222Rn and 220Rn concentrations were surveyed with electrostatic collectors of radon progeny on the campus of com-mercial school and some other areas in Hainan, southern China. Neither 222Rn nor 220Rn concentration was found significantly high. However, several faults underground were delineated. The collector is also used to study radon transportation. Results indicate that radon changes regularly with date when it has transported for a certain distance. Velocities of radon migration in the four media are quite different.Radon migrates more quickly in vertical tube than in the horizontal tube.

  10. Optical losses due to tracking error estimation for a low concentrating solar collector

    International Nuclear Information System (INIS)

    Highlights: • A solar thermal collector with low concentration and one-axis tracking was tested. • A quasi-dynamic testing procedure for IAM was defined for tracking collector. • The adequation between the concentrator optics and the tracking was checked. • The maximum and long-term optical losses due to tracking error were calculated. - Abstract: The determination of the accuracy of a solar tracker used in domestic hot water solar collectors is not yet standardized. However, while using optical concentration devices, it is important to use a solar tracker with adequate precision with regard to the specific optical concentration factor. Otherwise, the concentrator would sustain high optical losses due to the inadequate focusing of the solar radiation onto its receiver, despite having a good quality. This study is focused on the estimation of long-term optical losses due to the tracking error of a low-temperature collector using low-concentration optics. For this purpose, a testing procedure for the incidence angle modifier on the tracking plane is proposed to determinate the acceptance angle of its concentrator even with different longitudinal incidence angles along the focal line plane. Then, the impact of maximum tracking error angle upon the optical efficiency has been determined. Finally, the calculation of the long-term optical error due to the tracking errors, using the design angular tracking error declared by the manufacturer, is carried out. The maximum tracking error calculated for this collector imply an optical loss of about 8.5%, which is high, but the average long-term optical loss calculated for one year was about 1%, which is reasonable for such collectors used for domestic hot water

  11. Tracking local control of a parabolic trough collector; Control local de seguimiento cilindro parabolico ACE20

    Energy Technology Data Exchange (ETDEWEB)

    Ajona, J.I.; Alberdi, J.; Gamero, E.; Blanco, J.

    1992-07-01

    In the local control, the sun position related to the trough collector is measured by two photo-resistors. The provided electronic signal is then compared with reference levels in order to get a set of B logical signals which form a byte. This byte and the commands issued by a programmable controller are connected to the inputs of o P.R.O.M. memory which is programmed with the logical equations of the control system. The memory output lines give the control command of the parabolic trough collector motor. (Author)

  12. A numerical study of a vertical solar air collector with obstacle

    Science.gov (United States)

    Moumeni, A.; Bouchekima, B.; Lati, M.

    2016-07-01

    Because of the lack of heat exchange obtained by a solar air between the fluid and the absorber, the introduction of obstacles arranged in rows overlapping in the ducts of these systems improves heat transfer. In this work, a numerical study using the finite volume methods is made to model the dynamic and thermal behavior of air flow in a vertical solar collector with baffles destined for integration in building. We search essentially to compare between three air collectors models with different inclined obstacles angle. The first kind with 90° shows a good performance energetic and turbulent.

  13. Performance optimization of a subsonic Diffuser-Collector subsystem using interchangeable geometries

    OpenAIRE

    Boehm, Brian Patrick

    2013-01-01

    A subsonic wind tunnel facility was designed and built to test and optimize various diffuser-collector box geometries at the one-twelfth scale.  The facility was designed to run continuously at an inlet Mach number of 0.42 and an inlet hydraulic diameter Reynolds number of 340,000. Different combinations of diffusers, hubs, and exhaust collector boxes were designed and evaluated for overall optimum performance. Both 3-hole and 5-hole probes were traversed into the flow to generate multiple di...

  14. On mechanism of flotation of heavy metal ions with fatty acid collectors

    International Nuclear Information System (INIS)

    Kinetics investigation of flotation separation of heavy metal ions (scandium, yttrium, lanthanum, praseodymium, neodymium) from their chloride solutions is conducted. 1.2% aqueous solution of potassium caprinate is taken as collector, which is introduced in rare earth chloride solutions in amount stoichiometrically necessary for formation of compounds of the Me[CH3(CH2)8COO]3 type. It is shown that the order od kinetic equation, characterizing flotation process of rare earth ions, collected with an aid of fatty acid collectors, is determined by the nature and concentration of the ions separated

  15. A method for reducing the surface output work of the collector of a thermoemission converter

    Energy Technology Data Exchange (ETDEWEB)

    Gverdtsiteli, I.G.; Kakulnya, G.L.; Kalandarshvili, A.G.; Sirigul, Ye.V.

    1983-01-01

    The method for reducing the surface output work of a collector for a thermal emission converter (TEP), which includes the formation of a semiconductor (PP) film on the operational surface by direct introduction of vapors of a gallium and cesium alloy into the interelectrode clearance of the converter, is distinguished by the fact that in order to increase the output specific power of the converter with a collector chiefly made of niobium, an alloy with a molar portion ratio of cesium to gallium of 2 to 1 is used.

  16. On the design of base-collector junction of InGaAs/InP DHBT

    Institute of Scientific and Technical Information of China (English)

    JIN Zhi; LIU XinYu

    2009-01-01

    The effects of the composite-collector structure and the ,doping density in InGaAs/InP DHBT on the Kirk current have been studied. The effective grade layer in the discretely graded layer goes into the InGaAs setback layer. The formulas of the maximum doping density, the maximum Kirk current, and the corresponding 6-doping density are derived under different Kirk-effect conditions. Both the maximum collector doping density and the maximum Kirk current are dependent on the 8-doping layer. By opti-mizing the delta doping, the Kirk current density can be greatly increased.

  17. Metal glass vacuum tube solar collectors are approaching lower-medium temperature heat application.

    Science.gov (United States)

    Jiang, Xinian

    2010-04-26

    Solar thermal collectors are widely used worldwide mainly for hot water preparation at a low temperature (less than 80 degrees C). Applications including many industrial processes and central air conditioning with absorption chillers, instead require lower-medium temperature heat (between 90 degrees C and 150 degrees C) to be driven when using solar thermal energy. The metal absorber glass vacuum tube collectors (MGVT) are developed for this type of applications. Current state-of-art and possible future technology development of MGVT are presented. PMID:20607893

  18. Thin Flexible Lithium Ion Battery Featuring Graphite Paper Based Current Collectors with Enhanced Conductivity

    OpenAIRE

    Qu, Hang; Hou, Jingshan; Tang, Yufeng; Semenikihin, Oleg; Skorobogatiy, Maksim

    2015-01-01

    A flexible, light weight and high conductivity current collector is the key element that enables fabrication of high performance flexible lithium ion battery. Here we report a thin, light weight and flexible lithium ion battery that uses graphite paper enhanced with a nano-sized metallic layers as the current collector, LiFePO4 and Li4Ti5O12 as the cathode and anode materials, and PE membrane soaked in LiPF6 as a separator. Using thin and flexible graphite paper as a substrate for the current...

  19. A note on critical flow section in collector channels

    Indian Academy of Sciences (India)

    Subhasish Dey

    2001-10-01

    Generalized solution for the location of critical flow section in collector channels is presented. Based on the concept of the singularity, the dynamic equation of spatially varied flow (SVF) is solved using the flow resistance equations of von Karman (for rough regime) and Jain (for transitional and smooth regimes). The advantage of using Jain’s equations is that they provide the explicit forms of the Colebrook-White and Nikuradse equations. Computational steps for the determination of critical flow section in a collector channel, being dependent on channel geometry, roughness, longitudinal bed slope and inflow discharge, are given for different channel shapes.

  20. State of the art of performance evaluation methods for concentrating solar collectors

    Science.gov (United States)

    Hofer, Annie; Valenzuela, Loreto; Janotte, Nicole; Burgaleta, Juan Ignacio; Arraiza, Jaime; Montecchi, Marco; Sallaberry, Fabienne; Osório, Tiago; Carvalho, Maria João; Alberti, Fabrizio; Kramer, Korbinian; Heimsath, Anna; Platzer, Werner; Scholl, Stephan

    2016-05-01

    For the development and establishment of concentrating solar thermal collectors a reliable and comparable performance testing and evaluation is of great importance. To ensure a consistent performance testing in the area of low- temperature collectors a widely accepted and commonly used international testing standard (ISO 9806:2013) is already available. In contrast to this, the standard ISO 9806:2013 has not completely penetrated the testing sector of concentrating collectors yet. On that account a detailed literature review has been performed on published testing procedures and evaluation methodologies as well as existing testing standards. The review summarizes characteristics of the different steady-state, quasi-dynamic and fully dynamic testing methods and presents current advancements, assets and drawbacks as well as limitations of the evaluation procedures. Little research is published in the area of (quasi-) dynamic testing of large solar collectors and fields. As a complementary a survey has been conducted focusing on currently implemented evaluation procedures in this particular field. Among the ten participants of the survey were project partners of relevant industry and research institutions within the European project STAGE-STE (Work package 11 - Linear focusing STE technologies). The survey addressed general aspects of the systems under test, as well as required process conditions and detailed characteristics of the evaluation procedures. In congruence with the literature review, the survey shows a similar tendency: the quasi-dynamic testing method according ISO 9806:2013 presents the most common and advanced evaluation procedure mainly used in the context of tracking concentrating collectors for the performance assessment of parabolic trough collectors operating with thermal oil or pressurized water. These common solar systems can be evaluated with minor adaptions to the testing standard. Evaluation procedures focused on in-situ measurements in solar

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

    International Nuclear Information System (INIS)

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

  2. Computer Aided Design of Depressed Collectors for High Power Electron Tubes

    Science.gov (United States)

    Singh, A.; Valfells, A.; Kolander, M.; Granatstein, V. L.

    2003-12-01

    We present an overview of techniques and computer codes developed by us for systematic design of depressed collectors with special reference to devices that use gyrating electron beams. These techniques facilitate achievement of high power levels in electron tubes. ProfilEM is an aid to controlling the trajectories of primary electrons. BSCAT provides for tracing the trajectories of backscattered electrons. Multiple generations of backscatter can be obtained, while keeping the number of rays to be tracked within manageable limits. We describe examples of applying these codes to the case of two-stage depressed collectors for a 1.5 MW 110 GHz gyrotron.

  3. Survey of active solar thermal collectors, industry and markets in Canada : final report

    International Nuclear Information System (INIS)

    A survey of the solar thermal industry in Canada was presented. The aim of the survey was to determine the size of the Canadian solar thermal industry and market. Data were used to derive thermal energy output as well as avoided greenhouse gas (GHG) emissions from solar thermal systems. The questionnaire was distributed to 268 representatives. Results revealed annual sales of 24.2, 26.4 and 37.5 MWTH in 2002, 2003, and 2004 respectively, which represented over 50 per cent growth in the operating base during the 3 year survey period. Sales of all collector types grew substantially during the 3 year period, and survey respondents anticipated 20 per cent growth in both 2005 and 2006. Approximately 10 per cent of all sales were exported during 2002-2004. Unglazed liquid collectors constituted the majority of collector types sold in Canada, almost all of which were sold into the residential sector for swimming pool heating. The majority of air collectors were sold into the industrial/commercial and institutional (I/CI) sectors for use in space heating. Sales of liquid glazed and evacuated tube collectors were split between the residential and I/CI sectors. Residential sales were primarily for domestic water heating. In 2004, 23 per cent of sales in the residential sector were for combination domestic hot water and space heating applications, an indication of strong growth. Results of the survey indicated that the solar thermal market in Quebec differed from other regions, with more than double the annual per capita revenue of any other region as a result of greater market penetration of unglazed air collectors. Calculations of the GHG emissions avoided due to active solar thermal systems were made based on historical estimates of solar thermal installations. A model was developed to calculate an operating base by collector type from 1979 to the present. The model showed that many of the systems installed during the 1980s were decommissioned during the 1990s, and that

  4. 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.

  5. Examination of processes of heat exchange in collector thermosyphons of switching boards high degree of integration.

    Directory of Open Access Journals (Sweden)

    Nikolaenko Yu. Е.

    2007-12-01

    Full Text Available The article presents the research of heat exchange and hydrodynamics of the heat transfer medium in the channels of the collector thermosyphon built into the heat load switching board. The most rational geometry of evaporation channels is chosen. Experimentally obtained dependences of the temperature of switching boards surface on the power of supplied heat flow are given. It is shown that the insertion of collector thermosiphons based on slot channels into the switching board can halve the temperature of the heat-supply zone.

  6. Discovery of Non-random Spatial Distribution of Impacts in the Stardust Cometary Collector

    Science.gov (United States)

    Horz, Friedrich; Westphal, Andrew J.; Gainsforth, Zack; Borg, Janet; Djouadi, Zahia; Bridges, John; Franchi, Ian; Brownlee, Donald E.; Cheng. Andrew F.; Clark, Benton C.; Floss, Christine

    2007-01-01

    We report the discovery that impacts in the Stardust cometary collector are not distributed randomly in the collecting media, but appear to be clustered on scales smaller than 10 cm. We also report the discovery of at least two populations of oblique tracks. We evaluated several hypotheses that could explain the observations. No hypothesis was consistent with all the observations, but the preponderance of evidence points toward at least one impact on the central Whipple shield of the spacecraft as the origin of both clustering and low-angle oblique tracks. High-angle oblique tracks unambiguously originate from a non-cometary impact on the spacecraft bus just forward of the collector.

  7. ADVANCED HYBRID PARTICULATE COLLECTOR - PILOT-SCALE TESTING; TOPICAL

    International Nuclear Information System (INIS)

    A new concept in particulate control, called an advanced hybrid particulate collector (AHPC), is being developed at the Energy and Environmental Research Center (EERC) with U.S. Department of Energy (DOE) funding. In addition to DOE and the EERC, the project team includes W.L. Gore and Associates, Inc., Allied Environmental Technologies, Inc., and the Big Stone power station. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique approach to develop a compact but highly efficient system. Filtration and electrostatics are employed in the same housing, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and solves the problem of reentrainment and re-collection of dust in conventional baghouses. The objective of the AHPC is to provide and gt;99.99% particulate collection efficiency for particle sizes from 0.01 to 50(micro)m and be applicable for use with all U.S. coals at a lower cost than existing technologies. In previous field tests with the AHPC, some minor bag damage was observed that appeared to be caused by electrical effects. Extensive studies were then carried out to determine the reason for the bag damage and to find possible solutions without compromising AHPC performance. The best solution to prevent the bag damage was found to be perforated plates installed between the electrodes and the bags, which can block the electric field from the bag surface and intercept current to the bags. The perforated plates not only solve the bag damage problem, but also offer many other advantages such as operation at higher A/C (air-to-cloth) ratios, lower pressure drop, and an even more compact geometric arrangement. For this project, AHPC pilot-scale tests were carried out to understand the effect of

  8. Efficiency of simultaneous application of oxygen-containing materials of emitter and collector in thermoemission energy converters

    International Nuclear Information System (INIS)

    One studied characteristics of experimental cylindrical module of thermoemission converters with oxygen-containing single-crystalline tungsten emitter and oxygen-containing niobium collector. Both materials were obtained by means of gas phase process. One compared the obtained results with the previously obtained results for similar modules with collector made of different materials

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

    International Nuclear Information System (INIS)

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

  10. 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)

  11. OFFSET - RAY TRACING OPTICAL ANALYSIS OF OFFSET SOLAR COLLECTOR FOR SPACE STATION SOLAR DYNAMIC POWER SYSTEM

    Science.gov (United States)

    Jefferies, K.

    1994-01-01

    OFFSET is a ray tracing computer code for optical analysis of a solar collector. The code models the flux distributions within the receiver cavity produced by reflections from the solar collector. It was developed to model the offset solar collector of the solar dynamic electric power system being developed for Space Station Freedom. OFFSET has been used to improve the understanding of the collector-receiver interface and to guide the efforts of NASA contractors also researching the optical components of the power system. The collector for Space Station Freedom consists of 19 hexagonal panels each containing 24 triangular, reflective facets. Current research is geared toward optimizing flux distribution inside the receiver via changes in collector design and receiver orientation. OFFSET offers many options for experimenting with the design of the system. The offset parabolic collector model configuration is determined by an input file of facet corner coordinates. The user may choose other configurations by changing this file, but to simulate collectors that have other than 19 groups of 24 triangular facets would require modification of the FORTRAN code. Each of the roughly 500 facets in the assembled collector may be independently aimed to smooth out, or tailor, the flux distribution on the receiver's wall. OFFSET simulates the effects of design changes such as in receiver aperture location, tilt angle, and collector facet contour. Unique features of OFFSET include: 1) equations developed to pseudo-randomly select ray originating sources on the Sun which appear evenly distributed and include solar limb darkening; 2) Cone-optics technique used to add surface specular error to the ray originating sources to determine the apparent ray sources of the reflected sun; 3) choice of facet reflective surface contour -- spherical, ideal parabolic, or toroidal; 4) Gaussian distributions of radial and tangential components of surface slope error added to the surface normals at

  12. Collector attachment to lead-activated sphalerite - Experiments and DFT study on pH and solvent effects

    Science.gov (United States)

    Sarvaramini, A.; Larachi, F.; Hart, B.

    2016-03-01

    The interactions of diisobutyl dithiophosphinate with bare (un-activated) and lead-activated sphalerite were studied both experimentally and through DFT simulations. Sphalerite activated by lead in acidic and alkaline conditions showed considerably greater affinity for diisobutyl dithiophosphinate adsorption than bare sphalerite. Experimental observations supported by DFT simulations concur in that attachment of the solvated collector to the activated sphalerite surface is through adsorbed lead cations or lead hydroxides where as for the bare sphalerite, the collector was most stable in its solvated state and not as an adsorbed specie. Accounting for solvation effects by including a swarm of water molecules in DFT simulations was necessary to infer plausible surface interactions between collector, solvent, and bare or lead-activated sphalerite. The experimental data and DFT simulations indicate, affinity of the collector toward surface-adsorbed lead species was predicted to form stable covalent bonds between collector sulfur atoms and lead.

  13. Resource indexes of flat solar water-heating collectors in hot-water-supply systems: Part 3. Source data for calculations that depend on the weight, size, and heat engineering characteristics of the collector and the optic properties of the translucent collector coating

    International Nuclear Information System (INIS)

    Source data are given for calculating resource indexes of flat solar water-heating collectors (FSWHCs) in hot-water-supply systems (HWSSs) that depend on the weight, size, and heat engineering characteristics of the collectors of the type considered and on the optic properties of their translucent coating. (authors)

  14. The effects of volumetric flow rate and inclination angle on the performance of a solar thermal collector

    International Nuclear Information System (INIS)

    Highlights: • The efficiency of the ET200 solar collector is a linear function of mass flow rate. • When the volumetric flow rate increases the efficiency increases also. • The efficiency of the solar collector is a linear function of the inclination angle. • The collector efficiency increases when the inclination angle increases (0° to 60°). • It is important to operate at higher mass flow rates. - Abstract: A solar collector is a device that converts solar energy into heat. This paper presents an experimental study on the influences of volumetric flow rate and inclination angle on the performance of a solar collector. The tests were conducted on a solar energy demonstration system (ET200), which consists of a solar collector, a storage tank, a control and command cabinet and a high power lamp simulating solar energy. For radiation intensity of 1.033 kW/m2 and inclination angle of 0°, the results showed that the efficiency of the collector followed a linear relationship versus the flow rate; η = 0.68 × Qv + 49.79 and presented a coefficient of correlation (R2) of 0.9898. Similarly, the increase of the inclination angle from 0° to 60° increased the effectiveness of the collector. A linear relationship; η = 0.43 × α + 53.07 with a high coefficient of determination (R2 = 0.967) relates the collector efficiency to the inclination angle. It is important to operate at higher mass flow rates and take the collector angle at 0° in order to reach its meaning full efficiency (heating water)

  15. Thermal performance of direct-flow coaxial evacuated-tube solar collectors with and without a heat shield

    International Nuclear Information System (INIS)

    Graphical abstract: Collection efficiency plots and linear characterization of evacuated tube solar collector with a heat shield (ETC-HS) and evacuated tube solar collector without a heat shield (ETC-NHS). - Highlights: • Evacuated solar collector (ETC) with a heat shield had better thermal performance. • Efficiency of ETC with a heat shield is 54.70% at inlet temperature 123.9 °C. • 31.49% higher than efficiency of ETC without a heat shield at this temperature. • Heat loss coefficients of ETC with a heat shield was 1.86 W/(m2 K). • A 50.80% improvement in heat loss reduced compared to ETC without a heat shield. - Abstract: Experimental performance evaluation and comparative analyses based on heat extraction of direct-flow coaxial evacuated-tube solar collectors with and without heat shields are presented in this paper. A test system to evaluate the thermal performance of medium-temperature solar collectors was developed. The experimental analysis shows the evacuated-tube solar collector performed better with a heat shield, especially at higher working temperatures. The collection efficiency of the solar collector with a heat shield was 54.70% at the highest inlet temperature of 123.9 °C during the test period, which is 31.49% higher than for the solar collector without a heat shield. The calculated heat-loss coefficient for the evacuated-tube solar collector with a heat shield was 1.86 W/(m2 K), which is an improvement of 50.80% compared with that of the collector without a heat shield

  16. Safety provisions for steam generator in Mochovce nuclear power plant. BO CI 04 Integrity of primary collectors of VVER 440 steam generators

    International Nuclear Information System (INIS)

    This paper dealt with the identification of possible damaging mechanism of the collector of the WWER 440 steam generator, cracking of primary collectors, corrosion damage of the protective coat of the primary collector circumferential weld, cracking of breathing space in the region of blinding effect by corrosion and strain, leaking of disassembling joint of the primary collector lid and with the integrity of heat exchanging tubes

  17. Electron yield per ion charge-state correction for an ion collector with unsupressed secondary electron enission

    Czech Academy of Sciences Publication Activity Database

    Krása, Josef; Láska, Leoš; Stöckli, M. P.; Fry, D.

    2000-01-01

    Roč. 50, č. 7 (2000), s. 797-892. ISSN 0011-4626 R&D Projects: GA AV ČR IAA1010819 Institutional research plan: CEZ:AV0Z1010921 Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.298, year: 2000

  18. A correction for emittance-measurement errors caused by finite slit and collector widths

    International Nuclear Information System (INIS)

    One method of measuring the transverse phase-space distribution of a particle beam is to intercept the beam with a slit and measure the angular distribution of the beam passing through the slit using a parallel-strip collector. Together the finite widths of the slit and each collector strip form an acceptance window in phase space whose size and orientation are determined by the slit width, the strip width, and the slit-collector distance. If a beam is measured using a detector with a finite-size phase-space window, the measured distribution is different from the true distribution. The calculated emittance is larger than the true emittance, and the error depends both on the dimensions of the detector and on the Courant-Snyder parameters of the beam. Specifically, the error gets larger as the beam drifts farther from a waist. This can be important for measurements made on high-brightness beams, since power density considerations require that the beam be intercepted far from a waist. In this paper we calculate the measurement error and we show how the calculated emittance and Courant-Snyder parameters can be corrected for the effects of finite sizes of slit and collector. (Author) 5 figs., 3 refs

  19. 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.

  20. Simple collectors for cathodoluminescence in the SEM made from aluminium foil.

    Science.gov (United States)

    Boyde, A; Reid, S A

    1983-11-01

    Inexpensive cathodoluminescence collectors for scanning electron microscopes can easily be made from aluminium foil fashioned as tubes which abut against the window of the photomultiplier at one end and shroud the specimen at the other. Their use in the study of fluorescent labelled mineralized tissues is illustrated. PMID:6644803