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1

Radiant energy collector  

Science.gov (United States)

A cylindrical radiant energy collector is provided which includes a reflector spaced apart from an energy absorber. The reflector is of a particular shape which ideally eliminates gap losses. The reflector includes a plurality of adjacent facets of V shaped segments sloped so as to reflect all energy entering between said absorber and said reflector onto said absorber. The outer arms of each facet are sloped to reflect one type of extremal ray in a line substantially tangent to the lowermost extremity of the energy absorber. The inner arms of the facets are sloped to reflect onto the absorber all rays either falling directly thereon or as a result of reflection from an outer arm.

McIntire, William R. (Downers Grove, IL)

1983-01-01

2

Nonimaging radiant energy device  

Science.gov (United States)

A nonimaging radiant energy device may include a hyperbolically shaped reflective element with a radiant energy inlet and a radiant energy outlet. A convex lens is provided at the radiant energy inlet and a concave lens is provided at the radiant energy outlet. Due to the provision of the lenses and the shape of the walls of the reflective element, the radiant energy incident at the radiant energy inlet within a predetermined angle of acceptance is emitted from the radiant energy outlet exclusively within an acute exit angle. In another embodiment, the radiant energy device may include two interconnected hyperbolically shaped reflective elements with a respective convex lens being provided at each aperture of the device.

Winston, Roland (Chicago, IL); Ning, Xiaohui (North Providence, RI)

1996-01-01

3

Multiscale computational modeling of a radiantly driven solar thermal collector  

Science.gov (United States)

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 components of the device. We have used state-of-the-art computational fluid dynamics (CFD) software, Flow3D (www.flow3d.com) to model the effects of multiple coupled physical processes including buoyancy driven flow from local temperature differences within the plenums, fluid-solid momentum and heat transfer, and coupled radiation exchange between the aerogel, top glazing and environment. In addition, the CFD models include both convection and radiation exchange between the top glazing and the environment. Transient and steady-state thermal models have been constructed using COMSOL Multiphysics. The third level consists of a lumped-element system model, which enables rapid parametric analysis and helps to develop an understanding of the system behavior; the mathematical models developed and multiple CFD simulations studies focus on simultaneous solution of heat, momentum, mass and gas volume fraction balances and succeed in accurate state variable distributions confirmed by experimental measurements.

Ponnuru, Koushik

4

Radiant energy to electric energy converter  

Science.gov (United States)

Radiant energy is converted into electric energy by irradiating a capacitor including an ionic dielectric. The dielectric is a sintered crystal superionic conductor, e.g., lanthanum trifluoride, lanthanum trichloride, or silver bromide, so that a multiplicity of crystallites exist between electrodes of the capacitor. The radiant energy cyclically irradiates the dielectric so that the dielectric exhibits a cyclic photocapacitive like effect. Adjacent crystallites have abutting surfaces that enable the crystallites to effectively form a multiplicity of series capacitor elements between the electrodes. Each of the capacitor elements has a dipole layer only on or near its surface. The capacitor is initially charged to a voltage just below the dielectric breakdown voltage by connecting it across a DC source causing a current to flow through a charging resistor to the dielectric. The device can be utilized as a radiant energy detector or as a solar energy cell.

Sher, Arden (Inventor)

1980-01-01

5

Memory device for two-dimensional radiant energy array computers  

Science.gov (United States)

A memory device for two dimensional radiant energy array computers was developed, in which the memory device stores digital information in an input array of radiant energy digital signals that are characterized by ordered rows and columns. The memory device contains a radiant energy logic storing device having a pair of input surface locations for receiving a pair of separate radiant energy digital signal arrays and an output surface location adapted to transmit a radiant energy digital signal array. A regenerative feedback device that couples one of the input surface locations to the output surface location in a manner for causing regenerative feedback is also included

Schaefer, D. H.; Strong, J. P., III (inventors)

1977-01-01

6

Nonimaging radiant energy direction device  

Science.gov (United States)

A raidant energy nonimaging light direction device is provided. The device includes an energy transducer and a reflective wall whose contour is particularly determined with respect to the geometrical vector flux of a field associated with the transducer.

Winston, Roland (Chicago, IL)

1980-01-01

7

Radiant energy attenuation in electron beam therapy  

International Nuclear Information System (INIS)

The decelerator and bolus, which reduce radiant energy in electron beam radiotherapy, were investigated with respect to the interrelation between their quality of material, thickness and position, and the mean energy and depth-dose rate curve pattern. The date obtained indicated that an acryl decelerator fitted to the tube aperture had the disadvantage of entailing bremsstrahlung x-ray intervention as well as increased depth dose. An elastomeric bolus placed on the phantom surface, however, resulted in an increased surface dose and minimal x-ray intervention. When radiation was performed with the phantom surface held apart from the bolus, a build-up phenomenon occurred on the phantom surface with a consequent diminution of surface dose. It was concluded that a bolus is more effective than a decelerator fitted to the tube aperture for attenuation of radiant energy. It is more advantageous to irradiate with the bolus in contact with the skin in cases in which the target is localized in the superficial layer of the skin, and with the bolus apart from the skin in cases in which the target is situated deeper below the skin. (author)

8

Technical evaluation of a solar heating system having conventional hydronic solar collectors and a radiant panel slab. Final report  

Energy Technology Data Exchange (ETDEWEB)

A simple innovative solar heating design (Solar Option One) using conventional hydronic solar collectors and a radiant panel slab was constructed. An objective of hybrid solar design is to combine the relative advantages of active and passive design approaches while minimizing their respective disadvantages. A test house using the Solar Option One heating system was experimentally monitored to determine its energy based performance during the 1982-83 heating season. The test residence is located in Lyndonville, Vermont, an area which has a characteristically cold and cloudy climate. The two story residence has a floor area of about 1400 square feet and is constructed on a 720 square foot 5.5 inch thick floor slab. A 24 inch packed gravel bed is located beneath the slab and the slab-gravel bed is insulated by two inches of polystyrene insulation. The test building is of frame construction and uses insulation levels which have become commonplace throughout the country. The structure would not fall into the superinsulated category but was tightly constructed so as to have a low infiltration level. The building is sun-tempered in that windows were concentrated somewhat on the South side and all but avoided on the North. A solar greenhouse on the South side of the building was closed off from the structure permanently throughout the testing so as to better observe the solar heating invention without confounding variables. The monitoring equipment generated an internal gain of about 17,000 BTUs per day, roughly the equivalent of occupancy by two persons. A full description of the experimental testing program is given. System efficiency and performance are reported.

Starr, R.J.

1984-04-01

9

Direct conversion of infrared radiant energy for space power applications  

Science.gov (United States)

A proposed technology to convert the earth radiant energy (infrared albedo) for spacecraft power is presented. The resultant system would eliminate energy storage requirements and simplify the spacecraft design. The design and performance of a infrared rectenna is discussed.

Finke, R. C.

1982-01-01

10

Clouds and the Earth's Radiant Energy System  

Science.gov (United States)

The Clouds and the Earth's Radiant Energy System (CERES) is a key component of the Earth Observing System (EOS) program. The CERES instrument provides radiometric measurements of the Earth's atmosphere from three broadband channels. The CERES missions are a follow-on to the successful Earth Radiation Budget Experiment (ERBE) mission. The first CERES instrument (PFM) was launched on November 27, 1997, as part of the Tropical Rainfall Measuring Mission (TRMM). Two CERES instruments (FM1 and FM2) were launched into polar orbit on board the EOS flagship Terra on December 18, 1999, and two additional CERES instruments (FM3 and FM4) were launched on board EOS Aqua on May 4,2002. [Mission Objectives] The scientific justification for the CERES measurements can be summarized by three assertions: (1) changes in the radiative energy balance of the Earth-atmosphere system can cause long-term climate changes (e.g., carbon dioxide inducing global warming); (2) besides the systematic diurnal and seasonal cycles of incoming solar energy, changes in cloud properties (amount, height, optical thickness) cause the largest changes of the Earth's radiative energy balance; and (3) cloud physics is one of the weakest components of current climate models used to predict potential global climate change. CERES has four main objectives: 1) For climate change analysis, provide a continuation of the ERBE record of radiative fluxes at the top of the atmosphere (TOA), analyzed using the same algorithms that produced the ERBE data. 2) Double the accuracy of estimates of radiative fluxes at TOA and the Earth's surface. 3) Provide the first long-term global estimates of the radiative fluxes within the Earth's atmosphere. 4) Provide cloud property estimates that are consistent with the radiative fluxes from surface to TOA. [Temporal_Coverage: Start_Date=1997-12-27; Stop_Date=] [Spatial_Coverage: Southernmost_Latitude=-90; Northernmost_Latitude=90; Westernmost_Longitude=-180; Easternmost_Longitude=180].

Wielicki, Bruce A. (Principal Investigator); Barkstrom, Bruce R. (Principal Investigator)

11

Radiant Barriers Save Energy in Buildings  

Science.gov (United States)

Langley Research Center needed to coat the Echo 1 satellite with a fine mist of vaporized metal, and collaborated with industry to create "radiant barrier technology." In 2010, Ryan Garrett learned about a new version of the technology resistant to oxidation and founded RadiaSource in Ogden, Utah, to provide the NASA-derived technology for applications in homes, warehouses, gymnasiums, and agricultural settings.

2014-01-01

12

Radiant transfer in gas filled enclosures by radiant energy absorption distribution method  

International Nuclear Information System (INIS)

A radiant heat ray method is employed to determine the radiant energy absorption distribution in a nonisothermal enclosure filled with nonisothermal gas. This method eliminates the complexity of the zoning method in calculating the surface-surface, gas-gas and gas-surface direct exchange areas. It can also deal with the nonuniformity of the gas absorption coefficient and wall emissivity. A study on radiation in a cylindrical enclosure reveals that the radiant heat ray method requires less computation time and yields more accurate results than the Monte Carlo method in determining the absorption distribution. A combined method is developed which utilizes the absorption distribution as the data base for predicting the distributions of temperature and heat flux within an enclosure. The applications of this method are demonstrated by two systems: a continuous heating furnace and a marine boiler furnace. Theory is in good agreement with the field tests. The ultimate goal of the absorption method is to diagnose the enclosure radiation characteristics to find a means for homogenizing the surface heat transfer

13

Upper limits on the total radiant energy of solar flares  

Science.gov (United States)

Limits on the total radiant energy of solar flares during the period February-November 1980 are established using data collected by the solar-constant monitor (ACRIM) on the Solar Maximum Mission satellite. Results show typical limits of 6 x 10 to the 29th erg/sec for a 32-second integration time, with 5-sigma statistical significance, for an impulsive emission. For a gradual component, about 4 x 10 to the 32nd ergs total radiant energy is found. The limits are determined to lie about an order of magnitude higher than the total radiant energy estimated from the various known emission components, which indicates the presence of a heretofore unknown dominant component of flare radiation.

Hudson, H. S.; Willson, R. C.

1983-01-01

14

Enhancement of natural ventilation rate and attic heat gain reduction of roof solar collector using radiant barrier  

Energy Technology Data Exchange (ETDEWEB)

Presented in this paper are the experimental results on natural ventilation flow rate enhancement and attic heat gain reduction of a roof solar collector equipped with a radiant barrier (RB). Investigation was conducted using an open ended inclined rectangular channel with an RB. The RB was used on the lower plate while the upper plate was heated with constant heat flux intensity. The channel dimensions are 1.5 x 0.70 x 0.19 m. The slope of the channel was fixed at 30 from horizontal plane. Four heat flux (190.5, 285.7, 380.9 and 476.2 W m{sup -2}) and five air gap space (3, 5, 7, 9 and 11 cm) were considered. Data analysis was made to determine the free convection heat transfer coefficient and induced airflow rate using two dimensionless parameters, viz., Nusselt number (Nu) and Reynolds number (Re). The Nu and Re were correlated as a function of Ra sin30 and channel aspect ratio defined as the ratio of air gap space to the channel length. The relations obtained were as follows: Nu=0.371(Ra sin 30){sup 0.2223}(S/L){sup -0.0469} and Re=191.68(Ra sin30){sup 0.1213}(S/L){sup -0.085}. When compared to a conventional roof solar configuration with gypsum board on the lower part, it was observed that the use of RB increased convective heat transfer and airflow rate by about 40-50%, thereby increasing heat transfer reduction through the lower plate by about 50%. The developed correlations are useful for the design of such open-ended channels like the roof solar collector for passive ventilation of houses. (author)

Puangsombut, W.; Hirunlabh, J. [Building Scientific Research Center, King Mongkut' s University of Technology Thonburi, Bangmod, Thungkru, Bangkok 10140 (Thailand); Khedari, J.; Win, M.M. [South-East Asia University, 19/1 Petkasem Rd., Nongkhaem, Bangkok 10160 (Thailand); Zeghmati, B. [Centre d' Etudes Fondamentales-Groupe de Mechanique Acoustique et Instrumentation, Universite de Perpignan, 66870, Perpignan (France)

2007-06-15

15

CERES: Clouds and the Earth's Radiant Energy System  

Science.gov (United States)

This brochure gives a brief description of the science research that is being done with data from the Clouds and Earth's Radiant Energy System (CERES) instrument flying onboard NASA's Terra satellite. It also contains information about some of the data products and technical specifications.

1999-04-01

16

Design of energy efficient building with radiant slab cooling  

Science.gov (United States)

Air-conditioning comprises a substantial fraction of commercial building energy use because of compressor-driven refrigeration and fan-driven air circulation. Core regions of large buildings require year-round cooling due to heat gains from people, lights and equipment. Negative environmental impacts include CO2 emissions from electric generation and leakage of ozone-depleting refrigerants. Some argue that radiant cooling simultaneously improves building efficiency and occupant thermal comfort, and that current thermal comfort models fail to reflect occupant experience with radiant thermal control systems. There is little field evidence to test these claims. The University of Calgary's Information and Communications Technology (ICT) Building, is a pioneering radiant slab cooling installation in North America. Thermal comfort and energy performance were evaluated. Measurements included: (1) heating and cooling energy use, (2) electrical energy use for lighting and equipment, and (3) indoor temperatures. Accuracy of a whole building energy simulation model was evaluated with these data. Simulation was then used to compare the radiant slab design with a conventional (variable air volume) system. The radiant system energy performance was found to be poorer mainly due to: (1) simultaneous cooling by the slab and heating by other systems, (2) omission of low-exergy (e.g., groundwater) cooling possible with the high cooling water temperatures possible with radiant slabs and (3) excessive solar gain and conductive heat loss due to the wall and fenestration design. Occupant thermal comfort was evaluated through questionnaires and concurrent measurement of workstation comfort parameters. Analysis of 116 sets of data from 82 occupants showed that occupant assessment was consistent with estimates based on current thermal comfort models. The main thermal comfort improvements were reductions in (1) local discomfort from draft and (2) vertical air temperature stratification. The analysis showed that integrated architectural and mechanical design is required to achieve the potential benefits of radiant slab cooling, including: (1) reduction of peak solar gain via windows through (a) avoiding large window-to-wall ratios and/or (b) exterior shading of windows, (2) use of low-quality cooling sources such as cooling towers and ground water, especially in cold, dry climates, and (3) coordination of system control to avoid simultaneous heating and cooling.

Tian, Zhen

2007-12-01

17

The Effect of Radiant Energy from Climate Elements on Architecture  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Since radiant energy is one of the important resource of clean energy, it can scientifically been obtained from the sun. In research, areas and scientific development and managing the optimized consumption of fossil fuels and their high costs some measures can be taken to be evidences towards obtaining the integrated management of optimized consumption of energy. Geographical location of different areas are in close relationship with architectural directions of buildings such as establishment...

Fardin Nazafati Namin

2012-01-01

18

Analog to digital converter for two-dimensional radiant energy array computers  

Science.gov (United States)

The analog to digital converter stage derives a bit array of digital radiant energy signals representative of the amplitudes of an input radiant energy analog signal array and derives an output radiant energy analog signal array to serve as an input to succeeding stages. The converter stage includes a digital radiant energy array device which contains radiant energy array positions so that the analog array is less than a predetermined threshold level. A scaling device amplifies the radiant signal levels of the input array and the digital array so that the radiant energy signal level carried by the digital array corresponds to the threshold level. An adder device adds the signals of the scaled input and digital arrays at corresponding array positions to form the output analog array.

Shaefer, D. H.; Strong, J. P., III (inventors)

1977-01-01

19

Two-dimensional radiant energy array computers and computing devices  

Science.gov (United States)

Two dimensional digital computers and computer devices operate in parallel on rectangular arrays of digital radiant energy optical signal elements which are arranged in ordered rows and columns. Logic gate devices receive two input arrays and provide an output array having digital states dependent only on the digital states of the signal elements of the two input arrays at corresponding row and column positions. The logic devices include an array of photoconductors responsive to at least one of the input arrays for either selectively accelerating electrons to a phosphor output surface, applying potentials to an electroluminescent output layer, exciting an array of discrete radiant energy sources, or exciting a liquid crystal to influence crystal transparency or reflectivity.

Schaefer, D. H.; Strong, J. P., III (inventors)

1976-01-01

20

''Super-radiant'' states in intermediate energy nuclear physics  

International Nuclear Information System (INIS)

A ''super-radiant'' state emerges when, under certain conditions, one or a few ''internal'' states acquire a large collective decay width due to the coupling to one or a few ''external'' decay channels. The rest of the internal states are ''stripped'' of their decay width and become long lived quasistationary states. The essentials of such mechanism and its possible role in intermediate energy nuclear physics are discussed in this work

 
 
 
 
21

Radiant energy collection and conversion apparatus and method  

Science.gov (United States)

The apparatus for collecting radiant energy and converting same to alternate energy form includes a housing having an interior space and a radiation transparent window allowing, for example, solar radiation to be received in the interior space of the housing. Means are provided for passing a stream of fluid past said window and for injecting radiation absorbent particles in said fluid stream. The particles absorb the radiation and because of their very large surface area, quickly release the heat to the surrounding fluid stream. The fluid stream particle mixture is heated until the particles vaporize. The fluid stream is then allowed to expand in, for example, a gas turbine to produce mechanical energy. In an aspect of the present invention properly sized particles need not be vaporized prior to the entrance of the fluid stream into the turbine, as the particles will not damage the turbine blades. In yet another aspect of the invention, conventional fuel injectors are provided to inject fuel into the fluid stream to maintain the proper temperature and pressure of the fluid stream should the source of radiant energy be interrupted. In yet another aspect of the invention, an apparatus is provided which includes means for providing a hot fluid stream having hot particles disbursed therein which can radiate energy, means for providing a cooler fluid stream having cooler particles disbursed therein, which particles can absorb radiant energy and means for passing the hot fluid stream adjacent the cooler fluid stream to warm the cooler fluid and cooler particles by the radiation from the hot fluid and hot particles.

Hunt, Arlon J. (Oakland, CA)

1982-01-01

22

The Effect of Radiant Energy from Climate Elements on Architecture  

Directory of Open Access Journals (Sweden)

Full Text Available Since radiant energy is one of the important resource of clean energy, it can scientifically been obtained from the sun. In research, areas and scientific development and managing the optimized consumption of fossil fuels and their high costs some measures can be taken to be evidences towards obtaining the integrated management of optimized consumption of energy. Geographical location of different areas are in close relationship with architectural directions of buildings such as establishment of the buildings and their heights, direction of passage, size of furniture capable of being opened and other cases. The purpose of this paper is only human comfort and the base of comfort is using scientific findings in related topics.

Fardin Nazafati Namin

2012-06-01

23

Radiant energy during infrared neural stimulation at the target structure.  

Science.gov (United States)

Infrared neural stimulation (INS) describes a method, by which an infrared laser is used to stimulate neurons. The major benefit of INS over stimulating neurons with electrical current is its spatial selectivity. To translate the technique into a clinical application it is important to know the energy required to stimulate the neural structure. With this study we provide measurements of the radiant exposure, at the target structure that is required to stimulate the auditory neurons. Flat polished fibers were inserted into scala tympani so that the spiral ganglion was in front of the optical fiber. Angle polished fibers were inserted along scala tympani, and rotating the beveled surface of the fiber allowed the radiation beam to be directed perpendicular to the spiral ganglion. The radiant exposure for stimulation at the modiolus for flat and angle polished fibers averaged 6.78±2.15 mJ/cm(2). With the angle polished fibers, a 90° change in the orientation of the optical beam from an orientation that resulted in an INS-evoked maximum response, resulted in a 50% drop in the response amplitude. When the orientation of the beam was changed by 180°, such that it was directed opposite to the orientation with the maxima, minimum response amplitude was observed. PMID:25075261

Richter, Claus-Peter; Rajguru, Suhrud; Stafford, Ryan; Stock, Stuart R

2013-03-01

24

Clouds and the Earth's Radiant Energy System (CERES) experiment  

Science.gov (United States)

The Clouds and the Earth's Radiant Energy System (CERES) experiment will play a major role in NASA's planned multi-instrument multi-satellite Earth Observing System (EOS) program to observe and study the total Earth System on a global scale. The CERES experiment will provide EOS with a consistent data base of accurately known fields of radiation and of clouds; and will investigate the important question of the impact of clouds upon the radiative energy flow through the earth-atmosphere system. The CERES instruments will be an improved version of the Earth Radiation Budget Experiment (ERBE) broadband scanning radiometer instruments flown by NASA in the 1980s. This paper describes the CERES experiment approach and the current CERES instrument design status.

Cooper, John E.; Barkstrom, Bruce R.; Kopia, Leonard P.

1992-01-01

25

Clouds and the Earth's Radiant Energy System (CERES)  

Science.gov (United States)

The CERES (Clouds and the Earth's Radiant Energy System) experiment will play a major role in NASA's multi-platform Earth Observing System (EOS) program to observe and study the global climate. The CERES instruments will provide EOS scientists with a consistent data base of accurately known fields of radiation and of clouds. CERES will investigate the important question of cloud forcing and its influence on the radiative energy flow through the Earth's atmosphere. The CERES instrument is an improved version of the ERBE (Earth Radiation Budget Experiment) broadband scanning radiometer flown by NASA from 1984 through 1989. This paper describes the science of CERES, presents an overview of the instrument preliminary design, and outlines the issues related to spacecraft pointing and attitude control.

Carman, Stephen L.; Cooper, John E.; Miller, James; Harrison, Edwin F.; Barkstrom, Bruce R.

1992-01-01

26

Radiant energy receiver having improved coolant flow control means  

Science.gov (United States)

An improved coolant flow control for use in radiant energy receivers of the type having parallel flow paths is disclosed. A coolant performs as a temperature dependent valve means, increasing flow in the warmer flow paths of the receiver, and impeding flow in the cooler paths of the receiver. The coolant has a negative temperature coefficient of viscosity which is high enough such that only an insignificant flow through the receiver is experienced at the minimum operating temperature of the receiver, and such that a maximum flow is experienced at the maximum operating temperature of the receiver. The valving is accomplished by changes in viscosity of the coolant in response to the coolant being heated and cooled. No remotely operated valves, comparators or the like are needed.

Hinterberger, H.

1980-10-29

27

INFLUENCE OF RADIANT ENERGY ON THE WORK OF THE ELECTRO-OZONIZER MADE FOR STERILIZING SUBSTRATES  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The thermal balance of an electro-ozonizer is presented in this article. As the share of radiant energy having impact on heating of the generator of ozone is defined and the way of decrease in this influence is offered

Shevchenko A. A.; Denisenko E. A.; Mumro A. A.

2014-01-01

28

Wide-angle sensor measures radiant heat energy in corrosive atmospheres  

Science.gov (United States)

Ellipsoidal cavity device measures radiant heat energy over wide incident angles in corrosive atmospheres. The instrument consists of a cavity in copper heat sink sealed with sapphire window to protect thermocouple.

1965-01-01

29

Study of the possibility of using solar radiant energy for welding and brazing metals  

Science.gov (United States)

The solar spectrum at the surface of the earth is analyzed. A facility for creating concentrated solar radiant energy flux is described, and data on its energetic capabilities are presented. The technology of solar welding by the fusion technique and joining by high-temperature brazing is examined. The use of concentrated solar radiant energy for welding and brazing metals and alloys is shown. The results of mechanical tests and microscopic and macroscopic studies are presented.

Dvernyakov, V. S.; Frantsevich, I. N.; Pasichnyy, V. V.; Shiganov, N. A.; Korunov, Y. I.; Kasich-Pilipenko, I. Y.

1974-01-01

30

Energy transport in metal nanoparticle chains via sub-radiant plasmon modes.  

Science.gov (United States)

We investigate the propagation of surface plasmon polaritons through coupling of light to sub-radiant dipole modes in finite chains of Ag nanoparticles. End excitation of collections of closely spaced particles reveals a band of sub-radiant modes whereby the decay of surface plasmon polaritons due to radiative losses is minimized. We show that excitation of any of these sub-radiant modes results in the most efficient energy transfer throughout the optical spectrum, with smaller interparticle separations resulting in the longest propagation. PMID:21451673

Willingham, Britain; Link, Stephan

2011-03-28

31

Evaluation of the interaction with radiant energy of substances traversed by a bore hole  

International Nuclear Information System (INIS)

Disclosed is a well logging method and apparatus for obtaining impulse response of a formation traversed by a bore hole by means of correlation techniques. Use is made of a source of radiant energy and of a control element for said source to produce a substantially random or pseudorandom sequence of discrete bursts of radiant energy from the source to cause interactions of these bursts with the formation whereby characteristic radiations of interactions are produced. A detector is provided which is responsive to these radiations to produce corresponding signals. In one embodiment of my invention the impulse response, expressed by a function h(T), is obtained by crosscorrelating signals produced by the detector with signals representing the bursts of radiant energy from the source. In another embodiment the impulse response h(T) of the formation is obtained by autocorrelating signals produced by the detector. In another embodiment of my invention the outputs of two detectors, differently spaced from a source of radiant energy, are crosscorrelated. Using the function h(T), valuable information regarding physical properties of the formation may be obtained. The source of radiant energy may be a source of energetic neutrons, particularly of the deuteriumtritium type, or a source of gamma radiation or of microwaves, or a source of any other form of radiant energy

32

Energy, cost, and CO 2 emission comparison between radiant wall panel systems and radiator systems  

CERN Document Server

The main goal of this paper is to evaluate the possibility of application or replacement of radiators with low-temperature radiant panels. This paper shows the comparison results of operations of 4 space heating systems: the low-temperature radiant panel system without any additional thermal insulation of external walls (PH-WOI), the low-temperature radiant panel system with additional thermal insulation of external walls (PH-WI), the radiator system without any additional thermal insulation of external walls (the classical heating system) (RH-WOI), and the radiator system with additional thermal insulation of external walls (RH-WI). The operation of each system is simulated by software EnergyPlus. The investigation shows that the PH-WI gives the best results. The RH-WOI has the largest energy consumption, and the largest pollutant emission. However, the PH-WI requires the highest investment.

Boji?, Milorad; Mileti?, Marko; Maleševi?, Jovan; Boyer, Harry

2012-01-01

33

A variable goemetry retardation collector for low energy sputtering experiments  

International Nuclear Information System (INIS)

Low energy sputtering experiments with an isotope separator beam require a retardation collector system. As the irradiation energy is varied (from 50 eV up to 10 keV in our experiments) the beam waist shifts along the beam; however, a defined angle of incidence of the ions on the target surface is vital for the experiments. Consequently, the geometry of the immersion lens of the retardation system has to be adjusted according to the respective retardation potential. In this paper, a collector system with a cylindrical (two dimensional) immersion lens is presented where this necessary energy dependent geometry variation can be performed without breaking the vacuum. (orig.)

34

16 CFR 1209.6 - Test procedures for critical radiant flux.  

Science.gov (United States)

...attic floor insulation using a radiant heat energy source. (a) Apparatus and...The radiant panel generates a radiant energy flux distribution ranging along...opposite end of the chamber from the radiant energy source. The radiant...

2010-01-01

35

ENHANCING THE STABILITY OF THE BIRDS TO PULLOROZU INFLUENCE OF RADIANT ENERGY ????????? ???????????? ????? ? ????????? ???????????? ???????? ???????  

Directory of Open Access Journals (Sweden)

Full Text Available The article presents the research materials of viability of broiler chickens in bad conditions with pullorosis when exposed embryos and day-old chicks to radiant energy, the results of the content and lysozyme activity, bactericidal activity of serum lysozyme in relation to the test culture, the overall viability and survival of the birds in pullorosis in bad conditions

Tokhtiev T. A.

2013-09-01

36

Atmospheric radiative flux divergence from Clouds and Earth Radiant Energy System (CERES)  

Science.gov (United States)

A major objective of the Clouds and Earth Radiant Energy System (CERES) is the computation of vertical profiles through the atmosphere of the divergence of radiation flux, with global coverage. This paper discusses the need for radiation divergence and presents some options for its inference from CERES measurements and other data from the Earth Observating System.

Smith, Louis G.; Charlock, Thomas P.; Crommelynk, D.; Rutan, David; Gupta, Shashi

1990-01-01

37

INFLUENCE OF RADIANT ENERGY ON THE WORK OF THE ELECTRO-OZONIZER MADE FOR STERILIZING SUBSTRATES  

Directory of Open Access Journals (Sweden)

Full Text Available The thermal balance of an electro-ozonizer is presented in this article. As the share of radiant energy having impact on heating of the generator of ozone is defined and the way of decrease in this influence is offered

Shevchenko A. A.

2014-06-01

38

ENHANCING THE STABILITY OF THE BIRDS TO PULLOROZU INFLUENCE OF RADIANT ENERGY ????????? ???????????? ????? ? ????????? ???????????? ???????? ???????  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The article presents the research materials of viability of broiler chickens in bad conditions with pullorosis when exposed embryos and day-old chicks to radiant energy, the results of the content and lysozyme activity, bactericidal activity of serum lysozyme in relation to the test culture, the overall viability and survival of the birds in pullorosis in bad conditions

Tokhtiev T. A.; Mamukaev M. N.; Arsagov V. A.; Mashentseva D. V.

2013-01-01

39

Numerical modelling the unsteady process of closed rectangular area radiant heating in conjugate formulation with accounting energy distribution along horizontal and vertical enclosure structures  

Science.gov (United States)

Mathematical modelling of unsteady convective-conductive heat exchange in premises, heated by infrared radiant heater is passed. Heat flux density from infrared radiant heater was calculated accounting energy distribution along horizontal and vertical building envelope. Comparison between zonal method and Lambert's law radiant energy distribution was done.

Nee, A. E.

2014-08-01

40

Molecules, Water, and Radiant Energy: New Clues for the Origin of Life  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We here examine the putative first step in the origin of life: the coalescence of dispersed molecules into a more condensed, organized state. Fresh evidence implies that the driving energy for this coalescence may come in a manner more direct than previously thought. The sun’s radiant energy separates charge in water, and this free charge demonstrably induces condensation. This condensation mechanism puts water as a central protagonist in life rather than as an incidental participant, and t...

Qing Zhao; Pollack, Gerald H.; Xavier Figueroa

2009-01-01

 
 
 
 
41

Energy performance, comfort and ventilation effectiveness of radiant systems coupled with mechanical ventilation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This work presents the results of different numerical and experimental studies about energy performance, thermal comfort and ventilation effectiveness of radiant systems combined with different types of mechanical ventilation. Experimental studies have been carried out in Italy, in a test room in the laboratories of the company RHOSS S.p.A in Codroipo (Udine) and in Denmark, in a test room in the laboratories of the International Centre for Indoor Environment and Energy (ICIEE), at DTU (Danis...

Tomasi, Roberta

2012-01-01

42

The Clouds and the Earth's Radiant Energy System Elevation Bearing Assembly Life Test  

Science.gov (United States)

The Clouds and the Earth's Radiant Energy System (CERES) elevation scan bearings lubricated with Pennzane SHF X2000 and 2% lead naphthenate (PbNp) were life tested for a seven-year equivalent Low Earth Orbit (LEO) operation. The bearing life assembly was tested continuously at an accelerated and normal rate using the scanning patterns developed for the CERES Earth Observing System AM-1 mission. A post-life-test analysis was performed on the collected data, bearing wear, and lubricant behavior.

Brown, Phillip L.; Miller, James B.; Jones, William R., Jr.; Rasmussen, Kent; Wheeler, Donald R.; Rana, Mauro; Peri, Frank

1999-01-01

43

Radiant energy absorption studies for laser propulsion. [gas dynamics  

Science.gov (United States)

A study of the energy absorption mechanisms and fluid dynamic considerations for efficient conversion of high power laser radiation into a high velocity flow is presented. The objectives of the study are: (1) to determine the most effective absorption mechanisms for converting laser radiation into translational energy, and (2) to examine the requirements for transfer of the absorbed energy into a steady flow which is stable to disturbances in the absorption zone. A review of inverse Bremsstrahlung, molecular and particulate absorption mechanisms is considered and the steady flow and stability considerations for conversion of the laser power to a high velocity flow in a nozzle configuration is calculated. A quasi-one-dimensional flow through a nozzle was formulated under the assumptions of perfect gas.

Caledonia, G. E.; Wu, P. K. S.; Pirri, A. N.

1975-01-01

44

Heat collector  

Science.gov (United States)

A heat collector and method suitable for efficiently and cheaply collecting solar and other thermal energy are provided. The collector employs a heat pipe in a gravity-assist mode and is not evacuated. The collector has many advantages, some of which include ease of assembly, reduced structural stresses on the heat pipe enclosure, and a low total materials cost requirement. Natural convective forces drive the collector, which after startup operates entirely passively due in part to differences in molecular weights of gaseous components within the collector.

Merrigan, Michael A. (Santa Cruz, NM)

1984-01-01

45

Molecules, Water, and Radiant Energy: New Clues for the Origin of Life  

Directory of Open Access Journals (Sweden)

Full Text Available We here examine the putative first step in the origin of life: the coalescence of dispersed molecules into a more condensed, organized state. Fresh evidence implies that the driving energy for this coalescence may come in a manner more direct than previously thought. The sun’s radiant energy separates charge in water, and this free charge demonstrably induces condensation. This condensation mechanism puts water as a central protagonist in life rather than as an incidental participant, and thereby helps explain why life requires water.

Qing Zhao

2009-03-01

46

Solar Collectors  

Science.gov (United States)

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

1980-01-01

47

Proof of concept modeling of energy transfer mechanisms for radiant conditioning panels  

International Nuclear Information System (INIS)

Energy transfer by radiation decouples the heat transfer mechanisms from the ventilation function of the building air without sacrificing the thermal comfort of the occupants. The decoupling is responsible for the higher energy efficiency achieved when radiant cooling and heating systems are utilized. While empirical relations and experimental testing have been introduced by the literature, an analytical methodology that includes the necessary parameters needed for studying the energy transfer mechanisms is desirable. The objective of this study is to present a proof-of-concept formulation and procedure for modeling the heat transfer mechanisms of radiant conditioning panels with considerations for the occupant in a thermal zone. A literature review is conducted to identify the key parameters that affect the performance of the conditioning panels, and then, a proof of concept model is developed so that the performance of the conditioning panels can be analyzed. Using parameters with typical values, for a conventional size room as a thermal zone containing a window and an occupant, the thermal performance of a ceiling mounted conditioning panel is evaluated. Results from the model show that for a ceiling panel at 288.6 K in a 3 m x 3 m x 3 m thermal zone with an ambient temperature of 296.9 K, a 3 m x 2.5 m window and an occupant modeled as a sphere, the total energy flux for the panel is approximately 93.5 W/m2, which is 1.7% higher than that predicted by ach is 1.7% higher than that predicted by an existing empirical relation. It is concluded that the proposed analytical approach is effective as the findings from the model are in agreement with data available from the literature. The model could be used to examine other conditions for the radiant panel

48

Clouds and the Earth's Radiant Energy System (CERES) Visualization Single Satellite Footprint (SSF) Plot Generator  

Science.gov (United States)

The first Clouds and the Earth's Radiant Energy System (CERES) instrument will be launched in 1997 to collect data on the Earth's radiation budget. The data retrieved from the satellite will be processed through twelve subsystems. The Single Satellite Footprint (SSF) plot generator software was written to assist scientists in the early stages of CERES data analysis, producing two-dimensional plots of the footprint radiation and cloud data generated by one of the subsystems. Until the satellite is launched, however, software developers need verification tools to check their code. This plot generator will aid programmers by geolocating algorithm result on a global map.

Barsi, Julia A.

1995-01-01

49

Bi-radiant oven: a low-energy oven system. Volume I. Development and assessment  

Energy Technology Data Exchange (ETDEWEB)

The Bi-Radiant Oven system has three important features which provide improved performance. First, the cavity walls are highly reflective rather than absorptive thereby allowing these surfaces to operate at cooler temperatures. Second, the heating elements, similar in construction to those in a conventional oven, but operating at much lower temperatures, provide a prescribed, balanced radiant flux to the top and bottom surfaces of the food product. And third, the baking and roasting utensil has a highly absorptive finish. Instrumentation and methods of measurements have been developed for obtaining the important oven and food parameters during baking: wall, oven air, food and element temperatures; food mass loss rate; irradiance distribution; and convection heat flux. Observations on an experimental oven are presented and discussed. Thermal models relating the irradiance distribution to oven parameters have been compared with measurements using a new heat flux gage developed for the project. Using the DOE recommended test procedures, oven efficiencies of 20 to 23% have been measured. The heating requirements have been determined for seven food types: biscuits, meat loaf, baked foods, apple crisp, cornbread, macaroni and cheese casserole, and cheese souffle. Comparison of energy use with a conventional electric oven shows that energy savings greater than 50% can be realized. Detailed energy balances have been performed on two foods - beef roasts and yellow cake. Consideration of consumer acceptability of this new oven concept have been addressed.

DeWitt, D.P.; Peart, M.V.

1980-04-01

50

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

51

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Zhiyong Yang; Li Zhu; Yiping Wang

2011-01-01

52

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

53

Analysis of energy transfer in industrial gas -fired radiant tube furnaces  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A thermal system mathematical model has been developed to predict heat transfer from the products of combustion in the radiant tubes to the ultimate load in the furnace. The three-dimensional thermal model for the furnace involved the integration of various submodels for the radiant tube and the furnace enclosure.^ For the radiant tube, mathematical models were developed to describe turbulent interdiffusion of fuel and air, combustion, flame radiation and NO$\\sb{x}$ emissions from the syst...

Hariharan, Ramamurthy

1993-01-01

54

Energy, cost, and CO 2 emission comparison between radiant wall panel systems and radiator systems  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The main goal of this paper is to evaluate the possibility of application or replacement of radiators with low-temperature radiant panels. This paper shows the comparison results of operations of 4 space heating systems: the low-temperature radiant panel system without any additional thermal insulation of external walls (PH-WOI), the low-temperature radiant panel system with additional thermal insulation of external walls (PH-WI), the radiator system without any additional t...

Bojic?, Milorad; Cvetkovic?, Dragan; Miletic?, Marko; Males?evic?, Jovan; Boyer, Harry

2012-01-01

55

A hot wire radiant energy source for mapping the field of view of a radiometer  

Science.gov (United States)

The design and performance of a calibration device that allows the measurement of a radiometer's field of view are described. The heart of the device is a heated 0.0254-mm (0.001-inch) diameter filament that provides a variable, isothermal line source of radiant energy against a cold background. By moving this discrete line source across the field of view of a radiometer, the radiometer's spatial response can be completely mapped. The use of a platinum filament provides a durable radiation source whose temperature is stable and repeatable to 10 K over the range of 600 to 1200 K. By varying the energy emitted by the filament, the field of view of radiometers with different sensitivities (or multiple channel radiometers) can be totally mapped.

Edwards, S. F.; Stewart, W. F.; Vann, D. S.

1977-01-01

56

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.

57

Clouds and the Earth's Radiant Energy System (CERES) - An Earth Observing System experiment  

Science.gov (United States)

An overview is presented of the CERES experiment that is designed not only to monitor changes in the earth's radiant energy system and cloud systems but to provide these data with enough accuracy and simultaneity to examine the critical climate/cloud feedback mechanisms which may play a major role in determining future changes in the climate system. CERES will estimate not only the flow of radiation at the top of the atmosphere, but also more complete cloud properties that will permit determination of radiative fluxes within the atmosphere and at the surface. The CERES radiation budget data is also planned for utilization in a wide range of other Earth Observing System interdisciplinary science investigations, including studies of land, biological, ocean and atmospheric processes.

Wielicki, Bruce A.; Barkstrom, Bruce R.

1991-01-01

58

The influence of radiant energy on heat losses in small pressurizers, calculated with MODPRESS  

International Nuclear Information System (INIS)

In a previous work, a model for heat transfer coefficient (HTC) calculations was inserted in MODPRESS transient code for PWR pressurizer analysis, so the heat transfer to the surrounding air could be determined. The new routines were verified for Neptunus experimental test number U47, yielding a thermal power loss of 11.4 kW while experimental determinations point to 17.0 kW out. Several HTC correlations were extensively tested for the natural convection between wall and ambient air, but none was capable of justifying such discrepancy. Bearing in mind that, radiation heat loss may account for an important reaction of the global heat loss, in the present work, a HTC relative to the radiant energy was added to the natural convection HTC, resulting in a thermal loss of 16.8 kW. Now, this result compares very well to the experimental measurements, when using for the surface the emissivity of carbon steel. (author)

59

Determination of Unfiltered Radiances from the Clouds and the Earth's Radiant Energy System (CERES) Instrument  

Science.gov (United States)

A new method for determining unfiltered shortwave (SW), longwave (LW) and window (W) radiances from filtered radiances measured by the Clouds and the Earth's Radiant Energy System (CERES) satellite instrument is presented. The method uses theoretically derived regression coefficients between filtered and unfiltered radiances that are a function of viewing geometry, geotype and whether or not cloud is present. Relative errors in insta.ntaneous unfiltered radiances from this method are generally well below 1% for SW radiances (approx. 0.4% 1(sigma) or approx.l W/sq m equivalent flux), < 0.2% for LW radiances (approx. 0.1% 1(sigma) or approx.0.3 W/sq m equivalent flux) and < 0.2% (approx. 0.1% 1(sigma) for window channel radiances.

Loeb, N. G.; Priestley, K. J.; Kratz, D. P.; Geier, E. B.; Green, R. N.; Wielicki, B. A.; Hinton, P. OR.; Nolan, S. K.

2001-01-01

60

Modeling the spatial distribution of the volumic radiant energy and absorbed dose of radiation in the DNA structure under accelerated heavy ions  

International Nuclear Information System (INIS)

Model approaches are developed to the description of the mechanism of the formation of different types of atomic-level DNA lesions under accelerated heavy ions. The radial distribution of volumic radiant energy and the absorbed dose are calculated in accelerated heavy ions. The radial distribution of volumic radiant energy and the absorbed dose are calculated in accelerated 4He, 12C, and 40Ar ion tracks in the energy range of 3-20 MeV/nucleon. The spatial location of the atoms of an adenine-thymine nucleotide pair is compared with the calculated radial dose and volumic radiant energy distribution

 
 
 
 
61

Spatial sampling considerations of the CERES (Clouds and Earth Radiant Energy System) instrument  

Science.gov (United States)

The CERES (Clouds and Earth Radiant Energy System) instrument is a scanning radiometer with three channels for measuring Earth radiation budget. At present CERES models are operating aboard the Terra, Aqua and Suomi/NPP spacecraft and flights of CERES instruments are planned for the JPSS-1 spacecraft and its successors. CERES scans from one limb of the Earth to the other and back. The footprint size grows with distance from nadir simply due to geometry so that the size of the smallest features which can be resolved from the data increases and spatial sampling errors increase with nadir angle. This paper presents an analysis of the effect of nadir angle on spatial sampling errors of the CERES instrument. The analysis performed in the Fourier domain. Spatial sampling errors are created by smoothing of features which are the size of the footprint and smaller, or blurring, and inadequate sampling, that causes aliasing errors. These spatial sampling errors are computed in terms of the system transfer function, which is the Fourier transform of the point response function, the spacing of data points and the spatial spectrum of the radiance field.

Smith, G. L.; Manalo-Smith, Natividdad; Priestley, Kory

2014-10-01

62

Clouds and the Earth's Radiant Energy System (CERES): An Earth Observing System Experiment  

Science.gov (United States)

Clouds and the Earth's Radiant Energy System (CERES) is an investigation to examine the role of cloud/radiation feedback in the Earth's climate system. The CERES broadband scanning radiometers are an improved version of the Earth Radiation Budget Experiment (ERBE) radiometers. The CERES instruments will fly on several National Aeronautics and Space Administration Earth Observing System (EOS) satellites starting in 1998 and extending over at least 15 years. The CERES science investigations will provide data to extend the ERBE climate record of top-of-atmosphere shortwave (SW) and longwave (LW) radiative fluxes CERES will also combine simultaneous cloud property data derived using EOS narrowband imagers to provide a consistent set of cloud/radiation data, including SW and LW radiative fluxes at the surface and at several selected levels within the atmosphere. CERES data are expected to provide top-of-atmosphere radiative fluxes with a factor of 2 to 3 less error than the ERBE data Estimates of radiative fluxes at the surface and especially within the atmosphere will be a much greater challenge but should also show significant improvements over current capabilities.

Wielicki, Bruce A.; Barkstrom, Bruce R.; Harrison, Edwin F.; Lee, Robert B., III; Smith, G. Louis; Cooper, John E.

1996-01-01

63

The Clouds and the Earth's Radiant Energy System (CERES) Sensors and Preflight Calibration Plans  

Science.gov (United States)

The Clouds and the Earth's Radiant Energy System (CERES) spacecraft sensors are designed to measure broadband earth-reflected solar shortwave (0.3-5 microns) and earth-emitted longwave (5- > 100 microns) radiances at the top of the atmosphere as part of the Mission to Planet Earth program. The scanning thermistor bolometer sensors respond to radiances in the broadband shortwave (0.3-5 microns) and total-wave (0.3- > 100 microns) spectral regions, as well as to radiances in the narrowband water vapor window (8-12 microns) region. 'ne sensors are designed to operate for a minimum of 5 years aboard the NASA Tropical Rainfall Measuring Mission and Earth Observing System AM-1 spacecraft platforms that are scheduled for launches in 1997 and 1998, respectively. The flight sensors and the in-flight calibration systems will be calibrated in a vacuum ground facility using reference radiance sources, tied to the international temperature scale of 1990. The calibrations will be used to derive sensor gains, offsets, spectral responses, and point spread functions within and outside of the field of view. The shortwave, total-wave, and window ground calibration accuracy requirements (1 sigma) are +/-0.8, +/-0.6, and +/-0.3 W /sq m/sr, respectively, while the corresponding measurement precisions are +/-O.5% and +/-1.0% for the broadband longwave and shortwave radiances, respectively. The CERES sensors, in-flight calibration systems, and ground calibration instrumentation are described along with outlines of the preflight and in-flight calibration approaches.

Lee, Robert B., III; Barkstrom, Bruce R.; Smith, G. Louis; Cooper, John E.; Kopia, Leonard P.; Lawrence, R. Wes; Thomas, Susan; Pandey, Dhirendra K.; Crommelynck, Dominique A. H.

1996-01-01

64

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

65

16 CFR 1209.6 - Test procedures for critical radiant flux.  

Science.gov (United States)

...fueled radiant heat energy panel or equivalent panel inclined at 30° above...horizontally-mounted attic floor insulation specimen. The radiant panel generates a radiant energy...used to standardize the thermal output of the panel....

2010-01-01

66

Clouds and Earth Radiant Energy System (CERES), a Review: Past, Present and Future  

Science.gov (United States)

The Clouds and Earth Radiant Energy System (CERES) project s objectives are to measure the reflected solar radiance (shortwave) and Earth-emitted (longwave) radiances and from these measurements to compute the shortwave and longwave radiation fluxes at the top of the atmosphere (TOA) and the surface and radiation divergence within the atmosphere. The fluxes at TOA are to be retrieved to an accuracy of 2%. Improved bidirectional reflectance distribution functions (BRDFs) have been developed to compute the fluxes at TOA from the measured radiances with errors reduced from ERBE by a factor of two or more. Instruments aboard the Terra and Aqua spacecraft provide sampling at four local times. In order to further reduce temporal sampling errors, data are used from the geostationary meteorological satellites to account for changes of scenes between observations by the CERES radiometers. A validation protocol including in-flight calibrations and comparisons of measurements has reduced the instrument errors to less than 1%. The data are processed through three editions. The first edition provides a timely flow of data to investigators and the third edition provides data products as accurate as possible with resources available. A suite of cloud properties retrieved from the MODerate-resolution Imaging Spectroradiometer (MODIS) by the CERES team is used to identify the cloud properties for each pixel in order to select the BRDF for each pixel so as to compute radiation fluxes from radiances. Also, the cloud information is used to compute radiation at the surface and through the atmosphere and to facilitate study of the relationship between clouds and the radiation budget. The data products from CERES include, in addition to the reflected solar radiation and Earth emitted radiation fluxes at TOA, the upward and downward shortwave and longwave radiation fluxes at the surface and at various levels in the atmosphere. Also at the surface the photosynthetically active radiation and ultraviolet radiation (total, UVA and UVB) are computed. The CERES instruments aboard the Terra and Aqua spacecraft have served well past their design life times. A CERES instrument has been integrated onto the NPP platform and is ready for launch in 2011. Another CERES instrument is being built for launch in 2014, and plans are being made for a series of follow-on missions.

Smith, G. L.; Priestley, K. J.; Loeb, N. G.; Wielicki, B. A.; Charlock, T. P.; Minnis, P.; Doelling, D. R.; Rutan, D. A.

2011-01-01

67

Cloud Effects on Meridional Atmospheric Energy Budget Estimated from Clouds and the Earth's Radiant Energy System (CERES) Data  

Science.gov (United States)

The zonal mean atmospheric cloud radiative effect, defined as the difference of the top-of-atmosphere (TOA) and surface cloud radiative effects, is estimated from three years of Clouds and the Earth's Radiant Energy System (CERES) data. The zonal mean shortwave effect is small, though it tends to be positive (warming). This indicates that clouds increase shortwave absorption in the atmosphere, especially in midlatitudes. The zonal mean atmospheric cloud radiative effect is, however, dominated by the longwave effect. The zonal mean longwave effect is positive in the tropics and decreases with latitude to negative values (cooling) in polar regions. The meridional gradient of cloud effect between midlatitude and polar regions exists even when uncertainties in the cloud effect on the surface enthalpy flux and in the modeled irradiances are taken into account. This indicates that clouds increase the rate of generation of mean zonal available potential energy. Because the atmospheric cooling effect in polar regions is predominately caused by low level clouds, which tend to be stationary, we postulate that the meridional and vertical gradients of cloud effect increase the rate of meridional energy transport by dynamics in the atmosphere from midlatitude to polar region, especially in fall and winter. Clouds then warm the surface in polar regions except in the Arctic in summer. Clouds, therefore, contribute in increasing the rate of meridional energy transport from midlatitude to polar regions through the atmosphere.

Kato, Seiji; Rose, Fred G.; Rutan, David A.; Charlock, Thomas P.

2008-01-01

68

A theoretical study on area compensation for non-directly-south-facing solar collectors  

International Nuclear Information System (INIS)

Solar energy integrated with the building is an important approach for the synchronous development of solar energy and architecture. The energy gain of the solar collector integrated with the pitched roof has been greatly influenced by the roof azimuth and tilted angle. Investment cost of the collectors is mainly decided by the size of the collector area. Accordingly, it is significant for solar building design to economically determinate the area compensation of the solar collector at different azimuth and tilted angles. Take Kunming and Beijing as examples, area compensation for the flat-plate tube-fin solar collector used in southern regions and the evacuated tube collector with cylindrical absorbers used in northern regions in China have been theoretically calculated. The results to some extent show that the daily horizontal solar radiation, ambient temperature, the azimuth and tilted angle of the collector integrated into the roof have an influence on the area compensation. The azimuth angle and tilted angle of the roof are the main factors that influence the A/A , which is defined as the collector area ratio of the non-south-facing collectors to the south-facing ones with the optimal tilted angle. Comparative studies found that the range of A/A for the evacuated tube collector used in the northern regions is close to that for the flat-plate tube-fin solar collector used in the southern regions. When the pitched roof tilted angle ? element of [25 deg., 45 deg.] ed angle ? element of [25 deg., 45 deg.] and the azimuth angle vertical bar ? vertical bar ? 30 deg., the collectors can intercept a lot of solar radiant-energy. Considering the economic situations of the ordinary consumers in China, the optimal area compensation A/A ? 1.30 is recommended in this paper

69

A System for Determining Parameters of a Particle by Radiant Energy Scattering Techniques, Patent Application.  

Science.gov (United States)

The system for determining parameters of a particle described in this document is a government-owned invention that is available for licensing. The background of the invention is outlined, and drawings of the system together with a detailed description of its function are provided. A collector contains a hole and annular apertures for transmitting…

National Bureau of Standards (DOC), Washington, DC.

70

Some effects of 8-12 micron radiant energy transfer on the mass and heat budgets of cloud droplets  

Science.gov (United States)

In standard treatments of the mass and energy budget of cloud droplets, radiant energy transfer is neglected on the grounds that the temperature difference between the droplet and its surroundings is small. This paper includes the effect of radiant heating and cooling of droplets by using the Eddington approximation for the solution of the radiative transfer equation. Although the calculation assumes that the cloud is isothermal and has a constant size spectrum with altitude, the heating or cooling of droplets by radiation changes the growth rate of the droplets very significantly. At the top of a cloud with a base at 2500 m and a top at 3000 m, a droplet will grow from 9.5 to 10.5 microns in about 4 min, assuming a supersaturation ratio of 1.0013. Such a growth rate is more than 20 times the growth rate for condensation alone, and may be expected to have a significant impact on estimates of precipitation formation as well as on droplet spectrum calculations.

Barkstrom, B. R.

1978-01-01

71

Climate Model Evaluation using New Datasets from the Clouds and the Earth's Radiant Energy System (CERES)  

Science.gov (United States)

There are some in the science community who believe that the response of the climate system to anthropogenic radiative forcing is unpredictable and we should therefore call off the quest . The key limitation in climate predictability is associated with cloud feedback. Narrowing the uncertainty in cloud feedback (and therefore climate sensitivity) requires optimal use of the best available observations to evaluate and improve climate model processes and constrain climate model simulations over longer time scales. The Clouds and the Earth s Radiant Energy System (CERES) is a satellite-based program that provides global cloud, aerosol and radiative flux observations for improving our understanding of cloud-aerosol-radiation feedbacks in the Earth s climate system. CERES is the successor to the Earth Radiation Budget Experiment (ERBE), which has widely been used to evaluate climate models both at short time scales (e.g., process studies) and at decadal time scales. A CERES instrument flew on the TRMM satellite and captured the dramatic 1998 El Nino, and four other CERES instruments are currently flying aboard the Terra and Aqua platforms. Plans are underway to fly the remaining copy of CERES on the upcoming NPP spacecraft (mid-2010 launch date). Every aspect of CERES represents a significant improvement over ERBE. While both CERES and ERBE measure broadband radiation, CERES calibration is a factor of 2 better than ERBE. In order to improve the characterization of clouds and aerosols within a CERES footprint, we use coincident higher-resolution imager observations (VIRS, MODIS or VIIRS) to provide a consistent cloud-aerosol-radiation dataset at climate accuracy. Improved radiative fluxes are obtained by using new CERES-derived Angular Distribution Models (ADMs) for converting measured radiances to fluxes. CERES radiative fluxes are a factor of 2 more accurate than ERBE overall, but the improvement by cloud type and at high latitudes can be as high as a factor of 5. Diurnal cycles are explicitly resolved by merging geostationary satellite observations with CERES and MODIS. Atmospheric state data are provided from a frozen version of the Global Modeling and Assimilation Office- Data Assimilation System at the NASA Goddard Space Flight Center. In addition to improving the accuracy of top-of-atmosphere (TOA) radiative fluxes, CERES also produces radiative fluxes at the surface and at several levels in the atmosphere using radiative transfer modeling, constrained at the TOA by CERES (ERBE was limited to the TOA). In all, CERES uses 11 instruments on 7 spacecraft all integrated to obtain climate accuracy in TOA to surface fluxes. This presentation will provide an overview of several new CERES datasets of interest to the climate community (including a new adjusted TOA flux dataset constrained by estimates of heat storage in the Earth system), show direct comparisons between CERES ad ERBE, and provide a detailed error analysis of CERES fluxes at various time and space scales. We discuss how observations can be used to reduce uncertainties in cloud feedback and climate sensitivity and strongly argue why we should NOT "call off the quest".

Loeb, Norman G.; Wielicki, Bruce A.; Doelling, David R.

2008-01-01

72

Energy and exergy analysis of a latent heat storage system with phase change material for a solar collector  

Energy Technology Data Exchange (ETDEWEB)

Analysis of energy and exergy has been performed for a latent heat storage system with phase change material (PCM) for a flat-plate solar collector. CaCl{sub 2}.6H{sub 2}O was used as PCM in thermal energy storage (TES) system. The designed collector combines in single unit solar energy collection and storage. PCMs are stored in a storage tank, which is located under the collector. A special heat transfer fluid was used to transfer heat from collector to PCM. Exergy analysis, which is based on the second law of thermodynamics, and energy analysis, which is based on the first law, were applied for evaluation of the system efficiency for charging period. The analyses were performed on 3 days in October. It was observed that the average net energy and exergy efficiencies are 45% and 2.2%, respectively. (author)

Koca, Ahmet; Varol, Yasin [Department of Mechanical Education, Firat University, 23119 Elazig (Turkey); Oztop, Hakan F. [Department of Mechanical Engineering, Firat University, 23119 Elazig (Turkey); Koyun, Tansel [Department of Mechanical Engineering, Suleyman Demirel University, Isparta (Turkey)

2008-04-15

73

Radiant Energy Measurements from a Scaled Jet Engine Axisymmetric Exhaust Nozzle for a Baseline Code Validation Case  

Science.gov (United States)

A non-flowing, electrically heated test rig was developed to verify computer codes that calculate radiant energy propagation from nozzle geometries that represent aircraft propulsion nozzle systems. Since there are a variety of analysis tools used to evaluate thermal radiation propagation from partially enclosed nozzle surfaces, an experimental benchmark test case was developed for code comparison. This paper briefly describes the nozzle test rig and the developed analytical nozzle geometry used to compare the experimental and predicted thermal radiation results. A major objective of this effort was to make available the experimental results and the analytical model in a format to facilitate conversion to existing computer code formats. For code validation purposes this nozzle geometry represents one validation case for one set of analysis conditions. Since each computer code has advantages and disadvantages based on scope, requirements, and desired accuracy, the usefulness of this single nozzle baseline validation case can be limited for some code comparisons.

Baumeister, Joseph F.

1994-01-01

74

Energy and exergy analysis of photovoltaic-thermal collector with and without glass cover  

International Nuclear Information System (INIS)

In photovoltaic-thermal (PV/T) technology, the use of glass cover on the flat-plate hybrid solar collector is favorable to the photothermic process but not to the photovoltaic process. Because of the difference in the usefulness of electricity and thermal energy, there is often no straight forward answer on whether a glazed or unglazed collector system is more suitable for a specific application. This glazing issue was tackled in this paper from the viewpoint of thermodynamics. Based on experimental data and validated numerical models, a study of the appropriateness of glass cover on a thermosyphon-based water-heating PV/T system was carried out. The influences of six selected operating parameters were evaluated. From the first law point of view, a glazed PV/T system is found always suitable if we are to maximize the quantity of either the thermal or the overall energy output. From the exergy analysis point of view however, the increase of PV cell efficiency, packing factor, water mass to collector area ratio, and wind velocity are found favorable to go for an unglazed system, whereas the increase of on-site solar radiation and ambient temperature are favorable for a glazed system

75

Experimental evaluation of a stationary spherical reflector tracking absorber solar energy collector  

Science.gov (United States)

This article presents experimental data for the thermal performance of a stationary, spherical-reflector, tracking-absorber solar energy collector (SRTA). The principle of operation and details of thermal performance of such an SRTA have previously been described. These experimental results were compared with the predictions of a thermal analysis previously published. Experimental results were compared with the prediction of Kreider's computer model. Within the range of the temperature of the experiments, the predicted performance of the unit agreed well with experimental data collected under clear sky conditions. In addition, the extrapolation of the efficiency to higher temperature is shown so that the potential of an SRTA solar collector as a means of providing high temperature steam to operate an electric power facility or for process heat can be evaluated. As a result of the tests conducted by NASA, and an economic analysis not yet publicly available, it appears that the SRTA solar collector concept will be economically viable in competition with any other existing solar system in providing electrical energy.

Steward, W. G.; Kreider, J. F.; Caruso, P. S., Jr.; Kreith, F.

1976-01-01

76

High temperature air combustion. Evaluation of energy saving and NO{sub x} reduction in heat treatment furnaces equipped with radiant tube HiTAC burners. Final report  

Energy Technology Data Exchange (ETDEWEB)

The report presents results of experiments carried out between December 2002 and March 2003 in KTH, Energy and Furnace Technology Division, Stockholm. 30 tests were performed in order to compare the thermal performance of two different burning systems: recuperative and regenerative and their influence on the Radiant-tube at different operating conditions. Measurement results reveal that the temperature profile along the tube was more uniform when the regenerative system was used. Although, the preheated air temperature used for combustion was much higher in the case of regenerative system, the NO{sub x} emission was noticed to be almost the same in both cases. However, the pressure drop across the system was 10 times higher using regenerative system. In order to predict the benefits of the use of the regenerative system, calculations were being carried out. The results of these calculations show that the efficiency of the regenerative system can be up to 30 % higher than that of the recuperative system. The predicted annual saving can be more than 85,000 SEK per year assuming 8,760 operating hours if the burner operates at high thermal capacity and process temperature. Moreover, this theoretical analysis shows also that the maximum temperature of the Radiant-tube can be lower in the case of regenerative system of up to 75 deg C for the same thermal loading. Replacement of electrical resistant elements by radiant tubes that is change from electrical heating to gas fired radiant tubes in the same furnace can save 40% of primary fuel what is equivalent to 40% reduction in CO{sub 2} emission. Work performed was disseminated to industry by means of technical presentations and publications listed in reference list. Some interest was also generated in car manufacturing industry where the HiTAC and radiant tubes burners can be also widely applied.

Blasiak, Wlodzimierz; Szewczyk, Dariusz; Rafidi, Nabil; Jewartowski, Marcin; Goraj, Rafal [Royal Inst. of Technology, Stockholm (Sweden). Dept. of Materials Science and Engineering

2004-05-01

77

Novel concept for producing energy integrating a solar collector with a man made mountain hollow  

Energy Technology Data Exchange (ETDEWEB)

The concept of the solar chimney thermal power technology was proven with the successful operation of the Manzanares prototype built in the 1980s. However, all previous attempts at producing energy from a commercial solar chimney thermal power plant on a large scale have failed because of bad engineering and safety. A novel concept for producing energy by integrating a solar collector with a mountain hollow is presented and described. Solar energy is collected in the collector and heats the ground, which is used to store heat energy and heat the indoor air. Then, the hot air is forced by the pressure difference between it and the ambient air to move along the tilted segment and up the vertical segment of the 'chimney', driving the turbine generators to generate electricity. The mountain hollow, formed by excavation in a large-elevation mountain, can avoid the safety issues of erecting a gigantic concrete chimney, which is needed for commercial solar chimney thermal power plants. Furthermore, it can also save a great amount of construction materials for constructing a robust chimney structure and reduce the energy cost to a level less than that of a clean coal power plant, providing a good solution to the reclamation and utilization of undeveloped mountains, especially in mountainous countries.

Zhou Xinping [School of Civil Engineering and Mechanics, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei 430074 (China)], E-mail: zhxpmark@hotmail.com; Yang Jiakuan; Wang Jinbo; Xiao Bo [School of Environmental Science and Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road Wuhan, Hubei 430074 (China)

2009-03-15

78

Novel concept for producing energy integrating a solar collector with a man made mountain hollow  

Energy Technology Data Exchange (ETDEWEB)

The concept of the solar chimney thermal power technology was proven with the successful operation of the Manzanares prototype built in the 1980s. However, all previous attempts at producing energy from a commercial solar chimney thermal power plant on a large scale have failed because of bad engineering and safety. A novel concept for producing energy by integrating a solar collector with a mountain hollow is presented and described. Solar energy is collected in the collector and heats the ground, which is used to store heat energy and heat the indoor air. Then, the hot air is forced by the pressure difference between it and the ambient air to move along the tilted segment and up the vertical segment of the 'chimney', driving the turbine generators to generate electricity. The mountain hollow, formed by excavation in a large-elevation mountain, can avoid the safety issues of erecting a gigantic concrete chimney, which is needed for commercial solar chimney thermal power plants. Furthermore, it can also save a great amount of construction materials for constructing a robust chimney structure and reduce the energy cost to a level less than that of a clean coal power plant, providing a good solution to the reclamation and utilization of undeveloped mountains, especially in mountainous countries. (author)

Zhou, Xinping [School of Civil Engineering and Mechanics, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei 430074 (China); Yang, Jiakuan; Wang, Jinbo; Xiao, Bo [School of Environmental Science and Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road Wuhan, Hubei 430074 (China)

2009-03-15

79

Evaluation of the clouds and the Earth's radiant energy system (CERES) scanner pointing accuracy using a coastline detection system  

Science.gov (United States)

Clouds and the Earth's Radiant Energy System (CERES) is a NASA investigation to examine the role of clouds in the radiative energy flow through the Earth-atmosphere system. The first CERES scanning radiometer was launched on November 27, 1997 into a 35 degree inclination, 350 km altitude orbit, on the Tropical Rainfall Measuring Mission (TRMM) spacecraft. The CERES instrument consists of a three channel scanning broadband radiometer. The spectral bands measure shortwave, window and total radiation reflected or emitted from the Earth-atmosphere system. Each Earth viewing measurement is geolocated to the Earth fixed coordinate system using satellite ephemeris, Earth rotation and geoid, and instrument pointing data. The interactive CERES coastline detection system is used to assess the accuracy of the CERES geolocation process. By analyzing radiative flux gradients at the boundaries of ocean and land masses, the accuracy of the scanner measurement locations may be derived for the CERES/TRMM instrument/satellite system. The resulting CERES measurement location errors are within 10 percent of the nadir footprint size. Precise pointing knowledge of the Visible and IR scanner is required for convolution of cloud properties onto the CERES footprint; initial VIRS coastline results are included.

Currey, Jon C.; Smith, G. Louis; Neely, Bob

1998-10-01

80

Relationship Between the Clouds and the Earth's Radiant Energy System (CERES) Measurements and Surface Temperatures of Selected Ocean Regions  

Science.gov (United States)

Clear sky longwave radiances and fluxes are compared with the sea surface temperatures for three oceanic regions: Atlantic, Indian, and Pacific. The Clouds and the Earth's Radiant Energy System (CERES) measurements were obtained by the three thermistor bolometers: total channel which measures the radiation arising from the earth-atmosphere system between 0.3 - greater than 100 micrometers; the window channel which measures the radiation from 8-12 micrometers; and the shortwave channel which measures the reflected energy from 0.3 - less than 5.0 micrometers. These instruments have demonstrated measurement precisions of approximately 0.3% on the International Temperature Scale of 1990 (ITS-90) between ground and on-orbit sensor calibrations. In this work we have used eight months of clear sky earth-nadir-view radiance data starting from January 1998 through August 1998. We have found a very strong correlation of 0.97 between the CERES window channel's weekly averaged unfiltered spectral radiance values at satellite altitude (350 km) and the corresponding weekly averaged sea surface temperature (SST) data covering all the oceanic regions. Such correlation can be used in predicting the sea surface temperatures using the present CERES Terra's window channel radiances at satellite altitude very easily.

Pandey, Dhirendra, K.; Lee, Robert B., III; Brown, Shannon B.; Paden, Jack; Spence, Peter L.; Thomas, Susan; Wilson, Robert S.; Al-Hajjah, Aiman

2001-01-01

 
 
 
 
81

Evaluation of Clouds and the Earth's Radiant Energy System (CERES) Scanner Pointing Accuracy using a Coastline Detection System  

Science.gov (United States)

Clouds and the Earth's Radiant Energy System (CERES) is a National Aeronautics and Space Administration (NASA) investigation to examine the role of clouds in the radiative energy flow through the Earth-atmosphere system. The first CERES scanning radiometer was launched on November 27, 1997 into a 35 inclination, 350 km altitude orbit, on the Tropical Rainfall Measuring Mission (TRMM) spacecraft. The CERES instrument consists of a three channel scanning broadband radiometer. The spectral bands measure shortwave (0.3 - 5 microns), window (8 - 12 microns), and total (0.3 - 100 microns) radiation reflected or emitted from the Earth-atmosphere system. Each Earth viewing measurement is geolocated to the Earth fixed coordinate system using satellite ephemeris, Earth rotation and geoid, and instrument pointing data. The interactive CERES coastline detection system is used to assess the accuracy of the CERES geolocation process. By analyzing radiative flux gradients at the boundaries of ocean and land masses, the accuracy of the scanner measurement locations may be derived for the CERES/TRMM instrument/satellite system. The resulting CERES measurement location errors are within 10% of the nadir footprint size. Precise pointing knowledge of the Visible and Infrared Scanner (VIRS) is required for convolution of cloud properties onto the CERES footprint; initial VIRS coastline results are included.

Currey, Chris; Smith, Lou; Neely, Bob

1998-01-01

82

Apparatus for the collection of solar heat energy and a solar collector  

Energy Technology Data Exchange (ETDEWEB)

An apparatus for the collection of solar heat energy and a solar collector for use therewith in which a fluid media is conducted to flow in heat exchange relation with a heat absorber that can be selectively activated and deactivated for use without disassembly of the apparatus and in which the heat absorber is enclosed within a heat exchanger having a plurality of chambers at least one of which is in the path of the direct rays of the sun, but which permits an exchange and equalization of temperatures in all of the chambers while the whole is enclosed in an outer housing.

Sgroi, C. M.; Hubner, K. M.

1985-05-07

83

Mathematical modelling, variational formulation and numerical simulation of the energy transfer process in a gray plate in the presence of a thermal radiant source  

International Nuclear Information System (INIS)

The energy transfer process in a gray, opaque and rigid plate, heated by an external thermal radiant source, is considered. The source is regarded as a spherical black body, with radius a (a ? 0) and uniform heat generation, placed above the plate. A mathematical model is constructed, assuming that the heat transfer from/to the plate takes place by thermal radiation. The obtained mathematical model is nonlinear. Is presented a suitable variational principle which is employed for simulating some particular cases. (author)

84

Plant Production in Solar Collector Greenhouses - Influence on Yield, Energy Use Efficiency and Reduction in CO2 Emissions  

Directory of Open Access Journals (Sweden)

Full Text Available A semi-closed solar collector greenhouse was tested to evaluate the yield and the energy saving potential compared with a commercial greenhouse. As such, new algorithm for ventilation, carbon dioxide (CO2 enrichment, as well as for cooling and heating purposes initiated by a heat pump, cooling fins under the roof and a low temperature storage tank were developed. This cooling system showed that the collector greenhouse can be kept longer in the closed operation mode than a commercial one resulting in high levels of CO2 concentrations, relative humidity and temperatures. Based on these conditions, the photosynthesis and associated CO2 fixations within the plant population were promoted during the experiment, resulting in a yield increase by 32%. These results were realized, although the mean light interception by energy screens and finned tube heat exchangers was increased by 11% compared to the reference greenhouse. The energy use efficiency was improved by 103% when the collector greenhouse was considered as energy production facility. In this context, the energy saving per kilogram produced tomatoes in the collector greenhouse is equivalent to the combustion of high amounts of different fossil fuels, where the reduced CO2 emissions ranged between 2.32 kg and 4.18 kg CO2 per kg produced tomatoes. The generated total heat was composed of approximately one-third of the latent heat and over two-thirds of the sensible heat, where a maximum collector efficiency factor of 0.7 was achieved.

Dennis Dannehl

2013-09-01

85

Assessment of the Clouds and the Earth's Radiant Energy System (CERES) Flight Model 5 (FM5) instrument performance and stability  

Science.gov (United States)

The Clouds and the Earth's Radiant Energy System (CERES) scanning radiometer is designed to measure the solar radiation reflected by the Earth and thermal radiation emitted by the Earth. Four CERES instruments are supporting the EOS missions; two aboard the Terra spacecraft, launched in 1999 and two aboard the Aqua spacecraft, launched in 2002. A fifth instrument, Flight Model 5 (FM5), launched in October 2011 aboard the S-NPP satellite, began taking radiance measurements on January 27th, 2012. The CERES FM5 instrument uses three scanning thermistor bolometers to make broadband radiance measurements in the shortwave (0.3 - 5.0 micrometers), total (0.3 - CERES instrument package consisting of an anodized aluminum blackbody source for calibrating the total and window sensors, and a shortwave internal calibration source (SWICS) for the shortwave sensor. The ICM sources, along with a solar diffusor called the Mirror Attenuator Mosaic (MAM), are used to define shifts or drifts in the sensor response over the life of the mission. In addition, validation studies are conducted to assess the pointing accuracy of the instrument and understand any spectral changes that may occur with the sensors allowing for corrections to be made to the radiance calculations in later CERES data products. This paper summarizes the on-orbit behavior of the CERES FM5 instrument by outlining trends in the internal calibration data and discussing the various validation studies used to assess the performance and stability of the instrument.

Smith, Nathaniel P.; Thomas, Susan; Shankar, Mohan; Szewczyk, Z. P.; Wilson, Robert S.; Walikainen, Dale R.; Daniels, Janet L.; Hess, Phillip C.; Priestley, Kory J.

2014-09-01

86

Ground Calibrations of the Clouds and the Earth's Radiant Energy System (CERES) Tropical Rainfall Measuring Mission Spacecraft Thermistor Bolometers  

Science.gov (United States)

The Clouds and the Earth's Radiant Energy System (CERES) spacecraft scanning thermistor bolometers will measure earth-reflected solar and earth-emmitted,longwave radiances, at the top-of-the-atmosphere. The measurements are performed in the broadband shortwave (0.3-5.0 micron) and longwave (5.0 - >100 micron) spectral regions as well as in the 8 -12 micron water vapor window over geographical footprints as small as 10 kilometers at the nadir. The CERES measurements are designed to improve our knowledge of the earth's natural climate processes, in particular those related to clouds, and man's impact upon climate as indicated by atmospheric temperature. November 1997, the first set of CERES bolometers is scheduled for launch on the Tropical Rainfall Measuring Mission (TRMM) Spacecraft. The CERES bolometers were calibrated radiometrically in a vacuum ground facility using absolute reference sources, tied to the International Temperature Scale of 1990. Accurate bolometer calibrations are dependent upon the derivations of the radiances from the spectral properties [reflectance, transmittance, emittance, etc.] of both the sources and bolometers. In this paper, the overall calibration approaches are discussed for the longwave and shortwave calibrations. The spectral responses for the TRMM bolometer units are presented and applied to the bolometer ground calibrations in order to determine pre-launch calibration gains.

Lee, Robert B., III; Smith, G. Lou; Barkstrom, Bruce R.; Priestley, Kory J.; Thomas, Susan; Paden, Jack; Pandey, Direndra K.; Thornhill, K. Lee; Bolden, William C.; Wilson, Robert S.

1997-01-01

87

Global, Multi-Year Analysis of Clouds and Earth's Radiant Energy System Terra Observations and Radiative Transfer Calculations  

Science.gov (United States)

An extended record of the Terra Surface and Atmosphere Radiation Budget (SARB) computed by CERES (Clouds and Earth s Radiant Energy System) is produced in gridded form, facilitating an investigation of global scale direct aerosol forcing. The new gridded version (dubbed FSW) has a spacing of 1 at the Equator. A companion document (Rutan et al. 2005) focuses on advances to (and validation of) the ungridded, footprint scale calculations (dubbed CRS), primarily in clear-sky conditions. While mainly intended to provide observations of fluxes at the top of atmosphere (TOA), CERES (Wielicki et al. 1996) includes a program to also compute the fluxes at TOA, within the atmosphere and at the surface, and also to validate the results with independent ground based measurements (Charlock and Alberta 1996). ARM surface data has been a focus for this component of CERES. To permit the user to infer cloud forcing and direct aerosol forcing with the computed SARB, CERES includes surface and TOA fluxes that have been computed for cloud-free (clear) and aerosol free (pristine) footprints; this accounts for aerosol effects (SW scattering and absorption, and LW scattering, absorption and emission) to both clear and cloudy skies.

Charlock, T. P.; Rose, F. G.; Rutan, D. A.; Coleman, L. H.; Caldwell, T.; Zentz, S.

2005-01-01

88

Clouds and the Earth's Radiant Energy System (CERES) algorithm theoretical basis document. Volume 1; Overviews (subsystem 0)  

Science.gov (United States)

The theoretical bases for the Release 1 algorithms that will be used to process satellite data for investigation of the Clouds and the Earth's Radiant Energy System (CERES) are described. The architecture for software implementation of the methodologies is outlined. Volume 1 provides both summarized and detailed overviews of the CERES Release 1 data analysis system. CERES will produce global top-of-the-atmosphere shortwave and longwave radiative fluxes at the top of the atmosphere, at the surface, and within the atmosphere by using the combination of a large variety of measurements and models. The CERES processing system includes radiance observations from CERES scanning radiometers, cloud properties derived from coincident satellite imaging radiometers, temperature and humidity fields from meteorological analysis models, and high-temporal-resolution geostationary satellite radiances to account for unobserved times. CERES will provide a continuation of the ERBE record and the lowest error climatology of consistent cloud properties and radiation fields. CERES will also substantially improve our knowledge of the Earth's surface radiation budget.

Wielicki, Bruce A. (Principal Investigator); Barkstrom, Bruce R. (Principal Investigator); Baum, Bryan A.; Cess, Robert D.; Charlock, Thomas P.; Coakley, James A.; Green, Richard N.; Lee, Robert B., III; Minnis, Patrick; Smith, G. Louis

1995-01-01

89

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

90

Spectral Characterizations of the Clouds and the Earth's Radiant Energy System (CERES) Thermistor Bolometers using Fourier Transform Spectrometer (FTS) Techniques  

Science.gov (United States)

Fourier Transform Spectrometer (FTS) techniques are being used to characterize the relative spectral response, or sensitivity, of scanning thermistor bolometers in the infrared (IR) region (2 - >= 100-micrometers). The bolometers are being used in the Clouds and the Earth's Radiant Energy System (CERES) program. The CERES measurements are designed to provide precise, long term monitoring of the Earth's atmospheric radiation energy budget. The CERES instrument houses three bolometric radiometers, a total wavelength (0.3- >= 150-micrometers) sensor, a shortwave (0.3-5-micrometers) sensor, and an atmospheric window (8-12-micrometers) sensor. Accurate spectral characterization is necessary for determining filtered radiances for longwave radiometric calibrations. The CERES bolometers spectral response's are measured in the TRW FTS Vacuum Chamber Facility (FTS - VCF), which uses a FTS as the source and a cavity pyroelectric trap detector as the reference. The CERES bolometers and the cavity detector are contained in a vacuum chamber, while the FTS source is housed in a GN2 purged chamber. Due to the thermal time constant of the CERES bolometers, the FTS must be operated in a step mode. Data are acquired in 6 IR spectral bands covering the entire longwave IR region. In this paper, the TRW spectral calibration facility design and data measurement techniques are described. Two approaches are presented which convert the total channel FTS data into the final CERES spectral characterizations, producing the same calibration coefficients (within 0.1 percent). The resulting spectral response curves are shown, along with error sources in the two procedures. Finally, the impact of each spectral response curve on CERES data validation will be examined through analysis of filtered radiance values from various typical scene types.

Thornhill, K. Lee; Bitting, Herbert; Lee, Robert B., III; Paden, Jack; Pandey, Dhirendra K.; Priestley, Kory J.; Thomas, Susan; Wilson, Robert S.

1998-01-01

91

Potential Use of Radiant Walls to Transfer Energy Between two Building Zones  

DEFF Research Database (Denmark)

Due to a reduced energy demand in low energy buildings, low temperature heating and high temperature cooling can be used to control thermal comfort. Nevertheless, highly varying heat loads due to solar radiation can create sometimes an imbalanced energy demand inside the building. Instead of being considered as a disturbance, this asymmetry can be used as a heat source for another zone of the building. By means of computer simulations, the possibility of shifting the energy demand between two office rooms with different thermal loads has been studied. Due to the small temperature difference between the two zones, capillary tubes embedded in the surface of walls are used to exchange heat from a south-facing room to a north-facing room. In addition to having a better indoor climate, the total heating and cooling consumption decreases when running the system. A comparison has also been performed with a system exchanging room air directly.

Le Dreau, Jerome; Heiselberg, Per

2011-01-01

92

Optimal process of solar to thermal energy conversion and design of irreversible flat-plate solar collectors  

International Nuclear Information System (INIS)

Thermodynamic optimization based on the first and the second law is developed to determine the optimal performance parameters and to design a solar to thermal energy conversion system. An exergy analysis is presented to determine the optimum outlet temperature of the working fluid and the optimum path flow length of solar collectors with various configurations. The collectors used to heat the air flow during solar-to-thermal energy conversion, are internally arranged in different ways with respect to the absorber plates and heat transfer elements. The exergy balance and the dimensionless exergy relationships are derived by taking into account the irreversibilities produced by the pressure drop in the flow of the working fluid through the collector. Design formulas for different air duct and absorber plate arrangements are obtained

93

On-orbit solar calibration methods using the Clouds and Earth's Radiant Energy System (CERES) in-flight calibration system  

Science.gov (United States)

The Clouds and Earth's Radiant Energy System (CERES) scanning thermistor bolometers measure earth-reflected solar and earth-emitted longwaveradiances, at the top- of-the-atmosphere. The bolometers measure the earthradiances in the broadband shortwave solar (0.3-5.0 microns) and total (0.3-count conversion coefficients that are used to convert the bolometer output voltages into filtered earth radiances. The mirror attenuator mosaic (MAM), a solar diffuser plate, was built into the CERES instrument package calibration system in order to define in-orbit shifts or drifts in the sensor responses. The shortwave and shortwave part of the total sensors are calibrated using the solar radiances reflected from the MAM's. Each MAM consists of baffle-solar diffuser plate systems, which guide incoming solar radiances into the instrument fields of view of the shortwave and total wave sensor units. The MAM diffuser reflecting type surface consists of an array of spherical aluminum mirror segments, which are separated by a Merck Black A absorbing surface, overcoated with SIOx (SIO2 for PFM). Thermistors are located in each MAM plate and the total channel baffle. The CERES MAM is designed to yield calibration precisions approaching .5 percent for the total and shortwave detectors. In this presentation, the MAM solar calibration contrasting procedures will be presented along with on-orbit measurements for the eleven years the CERES instruments have been on-orbit. A switch to an azimuth rotation raster scan of the Sun rather than a fixed azimuth rotating elevation scan will be discussed. Comparisons are also made between the Terra, Aqua, and Suomi NPP CERES instruments during their MAM solar calibrations and total solar irradiance experimental results to determine how precise the CERES solar calibration facilities are at tracking the sun's irradiance.

Wilson, Robert S.; Priestley, Kory J.; Thomas, Susan; Hess, Phillip

2012-09-01

94

On-orbit solar calibrations using the Aqua Clouds and Earth's Radiant Energy System (CERES) in-flight calibration system  

Science.gov (United States)

The Clouds and the Earth's Radiant Energy System (CERES) spacecraft scanning thermistor bolometers were used to measure earth-reflected solar and earth-emitted longwave radiances, at satellite altitude. The bolometers measured the earth radiances in the broadband shortwave solar (0.3 - 5.0 micrometers) and total (0.3->100 micrometers) spectral bands as well as in the (8 - 12 micrometers) water vapor window spectral band over geographical footprints as small as 10 kilometers at nadir. In May 2002, the fourth and fifth sets of CERES bolometers were launched aboard the Aqua spacecraft. Ground vacuum calibrations defined the initial count conversion coefficients that were used to convert the bolometer output voltages into filtered earth radiances. The mirror attenuator mosaic (MAM), a solar diffuser plate, was built into the CERES instrument package calibration system in order to define in-orbit shifts or drifts in the sensor responses. The shortwave and total sensors are calibrated using the solar radiances reflected from the MAM's. Each MAM consists of baffle-solar diffuser plate systems, which guide incoming solar radiances into the instrument fields-of-view of the shortwave and total wave sensor units. The MAM diffuser reflecting type surface consists of an array of spherical aluminum mirror segments, which are separated by a Merck Black A absorbing surface, overcoated with silicon dioxide. Temperature sensors are located in each MAM plate and baffle. The CERES MAM wass designed to yield calibration precisions approaching .5 percent for the total and shortwave detectors. In this paper, the MAM solar calibration procedures are presented along with on-orbit results. Comparisons are also made between the Aqua,Terra and the Tropical Rainfall Measurement Mission (TRMM) CERES MAM solar calibrations.

Wilson, Robert S.; Priestley, Kory J.; Thomas, Susan; Hess, Phillip

2009-08-01

95

Earth Radiation Budget Experiment (ERBE) reprocessing using Clouds and the Earth's Radiant Energy System (CERES) angular distribution models  

Science.gov (United States)

NASA's Earth Radiation Budget Experiment (ERBE) scanning broadband radiometers flew on board the NOAA 9 (Feb 1985 to Jan 1987) and NOAA 10 (Jan 1987 to May 1989) and measured broadband shortwave (˜0.2 ?m to 5 ?m), longwave (5 ?m to 50 ?m) and total radiances. While the observations provided solid evidence of the cooling effect on the Earth system by clouds, the uncertainty of cloud radiative effects by region or by cloud type is large compared to those derived more recently from NASA's Clouds and the Earth Radiant Energy System (CERES) observations. In ERBE, top-of-atmosphere (TOA) irradiances were derived by applying 12 scene-type dependent angular distribution models (ADMs). Scene type viewed by ERBE scanners was estimated from broadband radiances using a maximum likelihood estimate method [1]. In this study, we use data taken by Advanced Very High Resolution Radiometer (AVHRR) on board the NOAA-9 satellite to derive cloud properties similar to those produced by the CERES cloud algorithm that utilizes Moderate Resolution Imaging Spectrometer (MODIS) data collocated with CERES footprints. This allows direct application of newer CERES ADMs to ERBE scanner radiances, which in turn reduces the uncertainty in the TOA irradiances. We describe the process of applying CERES ADMs and a comparison of the reprocessed data with original ERBE data. The reprocessing of 4 months of NOAA-9 measurements indicated increase in the global monthly mean shortwave TOA irradiance by ˜4%, while longwave TOA irradiance decreased by ˜0.5%, compared to irradiances derived from ERBE ADMs. These differences are largely caused by the pixel sizes of AVHRR and MODIS that yield different cloud type probability distributions.

Shrestha, A. K.; Kato, S.; Bedka, K. M.; Miller, W. F.; Wong, T.; Rutan, D. A.; Smith, G. L.; Fernandez, J. R.; Loeb, N.; Minnis, P.; Doelling, D. R.

2013-05-01

96

Performance evaluation and collector sizing for solar energy operated/assisted absorption machines under local climatic conditions  

International Nuclear Information System (INIS)

This paper presents the theoretical performance of solar energy operated/assisted continuous absorption air conditioning machines while operating under local climatic conditions. The two most commonly used pairs of working fluids i.e. LiBr-H/sub 2/O and NH/sub 3/ -H /sub 2/O have been employed in the study the thermodynamic analysis of the two absorption machines has been reported while operating in air conditioning mode and deriving input heat for the vapor generator from a flat plate solar collector. The COP, the relative solution circulation ratio and the energy transfer at various points in the system are also reported for both LiBr-H/sub 2/O and NH/sub 3/-H/sub 2/O absorption machines. The monthly average daily solar energy collected to drive the absorption machines and utilizability of solar energy while operating the hot water solar collector at the temperature of generation have been discussed. The collector aperture area required per TR (ton of refrigeration has been estimated for both the absorption machines. Monthly average daily collector efficiencies are also reported for the three summer months. Finally, the operating cost of VCS, gas operated VAS and solar energy operated VAS have been reported and conclusions have been made. (author)

97

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

Directory of Open Access Journals (Sweden)

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

Giovanni Angrisani

2014-10-01

98

Clouds and the earth's radiant energy system (CERES) - Instrument design and development  

Science.gov (United States)

Measurements of the earth's reflected shortwave and emitted longwave energy and of the effect of clouds on these quantities are planned using a refined version of the Earth Radiation Budget Experiment (ERBE) scanning instrument. The CERES instruments are being designed to accumulate earth radiance measurements with a repeatability of better than 0.5 percent over their five year life. Beginning in 1996, flights are planned on both polar and low earth orbit satellites to obtain the required temporal and spatial coverage. The design and development of CERES are discussed.

Kopia, Leonard P.

1991-01-01

99

Solar absorption characteristics of several coatings and surface finishes. [for solar energy collectors  

Science.gov (United States)

Solar absorption characteristics are established for several films potentially favorable for use as receiving surfaces in solar energy collectors. Included in the investigation were chemically produced black films, black electrodeposits, and anodized coatings. It was found that black nickel exhibited the best combination of selective optical properties of any of the coatings studied. A serious drawback to black nickel was its high susceptibility to degradation in the presence of high moisture environments. Electroplated black chrome generally exhibited high solar absorptivities, but the emissivity varied considerably and was also relatively high under some conditions. The black chrome had the greatest moisture resistance of any of the coatings tested. Black oxide coatings on copper and steel substrates showed the best combination of selective optical properties of any of the chemical conversion films studied.

Lowery, J. R.

1977-01-01

100

Apparatus and method for determining the position of a radiant energy source  

Science.gov (United States)

The position of a terrestrial RF source is determined from a geostationary, synchronous satellite by scanning the beam of a narrow beam width antenna in first and second orthogonal directions over a region including the source. The peak level of energy transduced by the antenna in each of the scanning directions is detected and correlated with the scanning position of the beam by feeding the output of a detector responsive to the transduced signal to an indicator of an X-Y recorder. The X and Y axes of the recorder are scanned in synchronism with the beam being respectively scanned in the first and second directions to form X and Y traces on which are indicated the detected peak position in each of the scanning directions. The source position is determined from an intersection of lines drawn parallel to the X and Y axes and including the detected peak position of each trace.

Schaefer, G. J. (inventor)

1981-01-01

 
 
 
 
101

Sandia invention to make parabolic trough solar collector systems more energy efficient  

Science.gov (United States)

This news release, from Sandia National Laboratories, announces the development of a system to align the long parabolic trough mirrors in a solar collector, thereby making it much more efficient. The article contains a description of how such trough solar collector systems and the new mirror alignment devices operate. Images are provided along with an outline of the group's anticipated progress.

2007-09-25

102

Satellite Collectors of Solar Energy for Earth and Colonized Planet Habitats  

Science.gov (United States)

Summary An array of 55,000 40-foot antennas can generate from the rays of the Sun enough electrical power to replace 50 The economic potential is huge. There are new industries that will only grow and there are different ways to collect solar energy, including wind power. The energy sources we rely on for the most part are finite - fossil fuels, coal, oil and natural gas are all limited in supply. The cost will only continue to rise as demand increases. The time of global economic crossover between the EU, Asia Pacific and North America is coming within less than five years. The biggest opportunity for solar energy entrepreneurs would seem to be in municipal contracting where 1500 40-foot stacking antennas can be hooked into a grid to power an entire city. The antenna can generate 45 kilowatts of energy, enough to satisfy the electrical needs 7x24 of ten to twenty homes. It is possible to design and build 35-by-80-foot pedestals that track the sun from morning until night to provide full efficiency. A normal solar cell looks in the sky for only four or five hours of direct sunlight. Fabrication of these pedestals would sell for USD 50, 000-70,000 each. The solar heat collected by the antennas can be bounced into a Stirling engine, creating electricity at a focal point. Water can be heated by running through that focal point. In addition, salt water passing through the focal point can be desalinated, and since the antenna can generate up to 2,000 degrees of heat at the focal point. The salt water passing through the focal point turns to steam, which separates the salt and allows the steam to be turned into fresh drinking water. Collector energy can be retained in betavoltaics which uses semiconductors to capture energy from radioactive materials and turn it into usable electricity for automobiles. In a new battery, the silicon wafers in the battery are etched with a network of deep pores. These pores vastly increase the exposure surface area of the silicon, allowing it to absorb more energy and making the antenna collector 20 times more efficient than planar designs. A tracking pedestal powered by betavoltaics can follow the sun. With a 500-sun photovoltaic cell underneath a Fresnal lens magnifies and distributes the sun's energy at 500 times. Primary results and the main conclusions This idea is revolutionary and utilizes satellite tracking abilities to follow the sun, maintaining a constant energy source that can reach 700 to 800 degrees. This technology will have many applications, from instant fresh water in the form of steam to the use of fiber optics to filter natural light through a building. With the direction of the oil and energy costs continuing to spiral upward, there has been recent emphasis on alternative energy that is transmitted from space. Satellite antenna manufacturers can move quickly to production and create a revolution in sustainable energy that was never thought of before. The efforts of the United States, Russia, China, and India to colonize the Moon and Mars would be greatly enhanced by use of satellite solar collectors and betavoltaics electrical energy technologies for the colonies' habitats. Introduction This study was undertaken for the Global environment is in a crisis. The rich oil producing countries of Russia, Saudi Arabia, Venezuela, and Africa, have been at war to gain monopoly power and to restrict the space based explorations of the solar system. The physics of solar energy transmission to electrical mechanical energy is unique in improving the economies of the entire community of Nations. It is easy to produce satellite antennas, thus, satellite antennas can now be used as solar panels which can generate free power from the sun by converting sunlight to electricity. Solar Panels require no moving parts; have zero emissions, and no maintenance. These antennas will revolutionize the use of solar rays from the sun to benefit a global grid. These "collectors of free energy" are able to harness solar energy for thermal heating, desalination, lighting, and electricity. Further,

Kusiolek, Richard

103

Analysis of potential energy, economic and environmental savings in residential buildings: Solar collectors combined with microturbines  

International Nuclear Information System (INIS)

Highlights: ? Centralization of energy systems for a group of buildings improves profitability. ? Thermal solar systems are economically interesting even in low radiation locations. ? Regulations currently in force determine the feasibility of high efficiency energy systems. - Abstract: This paper presents an analysis of a combined solar-cogeneration installation for providing energy services in a set of four residential buildings. Different configurations as regards the number of collectors and their orientation, the number of buildings grouped together, the type of microturbines used in the cogeneration system and their daily and annual operating period are studied from the legal, economic and environmental perspectives. The installation that fulfils the minimum requirements of the solar system coverage and the cogeneration system efficiency currently in force, and simultaneously leads to the highest energy, economic and environmental savings is the one that integrates both technologies and centralises the installation for the four buildings together. A payback period lower than 8 years is obtained that makes this investment recommendable, but it is also concluded that maintaining the existing subsidies for these technologies and lowering the costs of the equipment, are essential factors to ensure the feasibility of this type of installations

104

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

Energy Technology Data Exchange (ETDEWEB)

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.

Ballheim, R.W.

1980-04-25

105

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 results during the winter test period show that the system can provide a comfortable living space in winter, when the room temperature averaged 18.9 °C. The average COP of the heat pump system is 2.97 and with a maximum around 4.16.

Zhiyong Yang

2011-03-01

106

On-orbit solar calibrations using the Clouds and Earth's Radiant Energy System (CERES) in-flight calibration system  

Science.gov (United States)

The Clouds and Earth's Radiant Energy System (CERES) scanning thermistor bolometers measure earth-reflected solar and earth-emitted longwaveradiances, at the top- of-the-atmosphere. The bolometers measure the earthradiances in the broadband shortwave solar (0.3-5.0 microns) and total (0.3->100 microns) spectral bands as well as in the 8->12 microns water vapor window spectral band over geographical footprints as small as 10 kilometers at nadir. December 1999, the second and third set of CERES bolometers was launchedon the Earth Observing Mission Terra Spacecraft. May 2003, the fourth and fifth set of bolometers was launched on the Earth Observing Mission Aqua Spacecraft. Ground vacuum calibrations define the initial count conversion coefficients that are used to convert the bolometer output voltages into filtered earth radiances. The mirror attenuator mosaic (MAM), a solar diffuser plate, was built into the CERES instrument package calibration system in order to define in-orbit shifts or drifts in the sensor responses. The shortwave and shortwave part of total sensors are calibrated using the solar radiances reflected from the MAM's. Each MAM consists of baffle-solar diffuser plate systems, which guide incoming solar radiances into the instrument fields of view of the shortwave and total wave sensor units. The MAM diffuser reflecting type surface consists of an array of spherical aluminum mirror segments, which are separated by a Merck Black A absorbing surface, overcoated with SIOx. Thermistors are located in each MAM plate and the total channel baffle. The CERES MAM is designed to yield calibration precisions approaching .5 percent for the total and shortwave detectors. However, in their first year of operation the Terra and Aqua MAMs showed shifts in their calibrations larger than expected. Shifts of this nature have been seen in other Solar viewing instruments in the past. A possible explanation has attributed the changes to pre-orbit or on-orbit contamination combined with solar ultraviolet/atomic oxygen induced chemical changes to the contaminant during solar exposure. In the subsequent year of operation all instruments begin to stabilize within the .5 percent precision range. In this presentation, the MAM solar calibration procedures will be presented along with on-orbit measurements for the nine years the CERES instruments have been on-orbit. A switch to an azimuth rotation raster scan of the Sun rather than an elevation scan will be discussed. The implementation of a thermal correction to the shortwave channel will also be discussed. Comparisons are also made between the Terra CERES instruments and the Aqua instruments during their MAM solar calibrations and total solar irradiance experimental results to determine how precise the CERES solar calibration facilities are at tracking the sun's irradiance.

Wilson, Robert S.; Priestley, Kory J.; Thomas, Susan; Hess, Phillip

2010-09-01

107

The Oklahoma Field Test: Air-conditioning electricity savings from standard energy conservation measures, radiant barriers, and high-efficiency window air conditioners  

Energy Technology Data Exchange (ETDEWEB)

A field test Involving 104 houses was performed in Tulsa, Oklahoma, to measure the air-conditioning electricity consumption of low-income houses equipped with window air conditioners, the reduction in this electricity consumption attributed to the installation of energy conservation measures (ECMS) as typically installed under the Oklahoma Weatherization Assistance Program (WAP), and the reduction achieved by the replacement of low-efficiency window air conditioners with high-efficiency units and the installation of attic radiant barriers. Air-conditioning electricity consumption and indoor temperature were monitored weekly during the pre-weatherization period (June to September 1988) and post-weatherization period (May to September 1989). House energy consumption models and regression analyses were used to normalize the air-conditioning electricity savings to average outdoor temperature conditions and the pre-weatherization indoor temperature of each house. The following conclusions were drawn from the study: (1) programs directed at reducing air-conditioning electricity consumption should be targeted at clients with high consumption to improve cost effectiveness; (2) replacing low-efficiency air conditioners with high-efficiency units should be considered an option in a weatherization program directed at reducing air-conditioning electricity consumption; (3) ECMs currently being installed under the Oklahoma WAP (chosen based on effectiveness at reducing space-heating energy consumption) should continue to be justified based on their space-heating energy savings potential only; and (4) attic radiant barriers should not be included in the Oklahoma WAP if alternatives with verified savings are available or until further testing demonstrates energy savings or other benefits in this typo of housing.

Ternes, M.P.; Levins, W.P.

1992-08-01

108

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1996-10-27

109

Depressed collector for electron beams  

Science.gov (United States)

A depressed collector for recovery of spent beam energy from electromagnetic sources emitting sheet or large aspect ration annular electron beams operating aver a broad range of beam voltages and currents. The collector incorporates a trap for capturing and preventing the return of reflected and secondary electrons.

Ives, R. Lawrence (Inventor)

2005-01-01

110

Shenandoah parabolic dish solar collector  

Energy Technology Data Exchange (ETDEWEB)

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.

Kinoshita, G.S.

1985-01-01

111

Performance analysis for collector-side reflector systems  

Science.gov (United States)

The F-Chart method of solar collector performance evaluation is extended to a flat-plate collector system augmented with planar side reflectors. The modified F-Chart evaluations show that the augmentation of the collector has approximately the effect of increasing the collector area by 60%, and the energy supplied by the collector better matches the load. The installed reflector cost of about 10% of the collector cost is shown to be well justified.

Espy, P. N.

1979-01-01

112

Solar collector  

Energy Technology Data Exchange (ETDEWEB)

The invention concerns a solar collector with a case, in which an absorber in the form of a pipework system with a flow medium flowing through it is situated and which is provided on at least one wall with a transparent covering. The purpose of the invention is to create a solar collector of this type, where with different angles of incidence of radiation, the absorption capcity compared with well known collectors is increased, and particularly with diffuse radiation (a cloudy sky), a large amount of the short wave radiation is converted into heat. In order to solve the problem, the invention provides a pipework system which has at least one pipe of circular crossection. With a circular pipe there are more favourable angles of incidence for solar radiation than for a flate pipe because of the sun's movement during a long period of the day. A further advantage of the invention is that the pipework system has a reflector underneath it. The pipework system preferably consists of copper whose good thermal conductivity is well-known.

Roeser, H.P.

1980-02-28

113

Alternative energy sources IV; Proceedings of the Fourth Miami International Conference, Miami Beach, FL, December 14-16, 1981. Volume 1 - Solar Collectors Storage  

Science.gov (United States)

Aspects of solar measurements, solar collectors, selective coatings, thermal storage, phase change storage, and heat exchangers are discussed. The analysis and testing of flat-plate solar collectors are addressed. The development and uses of plastic collectors, a solar water heating system, solar energy collecting oil barrels, a glass collector panel, and a two-phase thermosyphon system are considered. Studies of stratification in thermal storage, of packed bed and fluidized bed systems, and of thermal storage in solar towers, in wall passive systems, and in reversible chemical reactions are reported. Phase change storage by direct contact processes and in residential solar space heating and cooling is examined, as are new materials and surface characteristics for solar heat storage. The use of R-11 and Freon-113 in heat exchange is discussed. No individual items are abstracted in this volume

Veziroglu, T. N.

1982-10-01

114

Chaotic dynamics of a classical radiant cavity  

CERN Document Server

The statistical properties of a classical electromagnetic field in interaction with matter are numerically investigated on a one-dimensional model of a radiant cavity, conservative and with finite total energy. Our results suggest a trend towards equipartition of energy, with the relaxation times of the normal modes of the cavity increasing with the mode frequency according to a law, the form of which depends on the shape of the charge distribution.

Benenti, G; Guarneri, I; Benenti, Giuliano; Casati, Giulio; Guarneri, Italo

1999-01-01

115

Magnetic droplet radiator collectors  

International Nuclear Information System (INIS)

Radiating heat via a droplet sheet offers a light weight, easily deployable means of rejecting energy from a spacecraft. Uncertainties in the trajectory of the droplets and splashing in the droplet collector can lead to unacceptable coolant mass losses. A study conducted at Brookhaven National Laboratory has investigated using ferrofluids with magnetic collectors to reduce these potential losses. Streams of ferrofluid droplets have been produced through 100 and 150 ?m orifices. These droplets have been accelerated in excess of five ''g's'' using permanent magnets and have been observed to behave stably and remain intact. Preliminary testing with thirty-seven parallel streams indicates that, except for collector splashing, multiple streams behave, from a fluid's viewpoint, like single streams. Single drops impacting under conditions known to produce satellite drops following impact were observed for varying magnetic conditions. At roughly one kilogauss, all incoming material would be captured under weightless conditions. Rebounding material tends to flow along lines of magnetic flux. Trade studies indicate that a range of conditions exists over which magnetic collections offer a weight advantage over a heat pipe radiator or droplet radiator with a large collector. 11 figs

116

Multipass air solar collectors  

Science.gov (United States)

Instantaneous thermal efficiencies are calculated for flat-plate solar collectors of various configurations which use air exposed to solar radiation or the solar absorber one or many times as the heat transport medium. The efficiencies of 18 potential models are obtained from numerical calculations of air flow and thermal loss distribution in the collector channels, incident solar radiation, solar radiation absorption, and the energy balance and air temperature increase following each pass through the collector. Plots of the instantaneous thermal efficiency as a function of inlet air temperature under standard operating conditions reveal that, if nonselective materials are used for the collector, models utilizing one or two covers with air flow only behind the solar absorber are most suitable, with only a few models with one cover and one selective surface having higher performance than the most efficient two-cover model with nonselective materials. For relatively high air inlet temperatures, a model with two covers and one selective surface having air flow only behind the absorber is also found to be superior. In the case of models with two selective covers, highest performance was obtained for models with parallel air flow in front of and behind the absorber, and flow only behind the absorber. It is noted that the use of two selective surfaces is, however, not justified at low inlet temperatures.

Granier, P.; Daguenet, M.

1981-06-01

117

Coloration Determination of Spectral Darkening Occurring on a Broadband Earth Observing Radiometer: Application to Clouds and the Earth's Radiant Energy System (CERES)  

Science.gov (United States)

It is estimated that in order to best detect real changes in the Earth s climate system, space based instrumentation measuring the Earth Radiation Budget (ERB) must remain calibrated with a stability of 0.3% per decade. Such stability is beyond the specified accuracy of existing ERB programs such as the Clouds and the Earth s Radiant Energy System (CERES, using three broadband radiometric scanning channels: the shortwave 0.3 - 5microns, total 0.3. > 100microns, and window 8 - 12microns). It has been shown that when in low earth orbit, optical response to blue/UV radiance can be reduced significantly due to UV hardened contaminants deposited on the surface of the optics. Since typical onboard calibration lamps do not emit sufficient energy in the blue/UV region, this darkening is not directly measurable using standard internal calibration techniques. This paper describes a study using a model of contaminant deposition and darkening, in conjunction with in-flight vicarious calibration techniques, to derive the spectral shape of darkening to which a broadband instrument is subjected. Ultimately the model uses the reflectivity of Deep Convective Clouds as a stability metric. The results of the model when applied to the CERES instruments on board the EOS Terra satellite are shown. Given comprehensive validation of the model, these results will allow the CERES spectral responses to be updated accordingly prior to any forthcoming data release in an attempt to reach the optimum stability target that the climate community requires.

Matthews, Grant; Priestley, Kory; Loeb, Norman G.; Loukachine, Konstantin; Thomas, Susan; Walikainen, Dale; Wielicki, Bruce A.

2006-01-01

118

Use of compound parabolic concentrator for solar energy collection  

Energy Technology Data Exchange (ETDEWEB)

The joint team of Argonne National Laboratory (ANL) and the University of Chicago is reporting their midyear results of a proof-of-concept investigation of the Compound Parabolic Concentrator (CPC) for solar-energy collection. The CPC is a non-imaging, optical-design concept for maximally concentrating radiant energy onto a receiver. This maximum concentration corresponds to a relative aperture (f/number) of 0.5, which is well beyond the limit for imaging collectors. We have constructed an X3 concentrating flat-plate collector 16 ft/sup 2/ in area. This collector has been tested in a trailer laboratory facility built at ANL. The optical and thermal performance of this collector was in good agreement with theory. We have constructed an X10 collector (8 ft/sup 2/) and started testing. A detailed theoretical study of the optical and thermal characteristics of the CPC design has been performed.

Rabi, A.; Sevcik, V.J.; Giugler, R.M.; Winston, R.

1974-01-01

119

On-orbit stability and performance of the Clouds and Earth's Radiant Energy System (CERES) instrument sensors onboard the Aqua and Terra Spacecraft  

Science.gov (United States)

The Clouds and Earth's Radiant Energy System (CERES) instruments onboard the Terra and Aqua spacecraft are part of the NASA Earth Observing System (EOS) constellation to make long-term observations of the earth. CERES measures the earth-reflected shortwave energy as well as the earth-emitted thermal energy, which are two components of the earth's radiation energy budget. These measurements are made by five instruments- Flight Models (FM) 1 and 2 onboard Terra, FMs 3 and 4 onboard Aqua and FM5 onboard Suomi NPP. Each instrument comprises three sensors that measure the radiances in different wavelength bands- a shortwave sensor that measures in the 0.3 to 5 micron band, a total sensor that measures all the incident energy (0.3-200 microns) and a window sensor that measures the water-vapor window region of 8 to 12 microns. The stability of the sensors is monitored through on-orbit calibration and validation activities. On-orbit calibration is carried out using the Internal Calibration Module (ICM) that consists of a tungsten lamp, blackbodies, and a solar diffuser known as the Mirror Attenuator Mosaic (MAM). The ICM calibration provides information about the stability of the sensors' broadband radiometric gains on-orbit. Several validation studies are conducted in order to monitor the behavior of the instruments in various spectral bands. The CERES Edition-4 data products for FM1-FM4 incorporate the latest corrections to the sensor responses using the calibration techniques. In this paper, we present the on-orbit performance stability as well as some validation studies used in deriving the CERES Edition-4 data products from all four instruments.

Shankar, Mohan; Priestley, Kory; Smith, Nitchie; Thomas, Susan; Walikainen, Dale

2014-09-01

120

Estimate of Top-of-Atmosphere Albedo for a Molecular Atmosphere over Ocean using Clouds and the Earth's Radiant Energy System (CERES) Measurements  

Science.gov (United States)

The shortwave broadband albedo at the top of a molecular atmosphere over ocean between 40deg N and 40deg S is estimated using radiance measurements from the Clouds and the Earth's Radiant Energy System (CERES) instrument and the Visible Infrared Scanner (VIRS) aboard the Tropical Rainfall Measuring Mission (TRMM) satellite. The albedo monotonically increases from 0.059 at a solar zenith angle of 10deg to 0.107 at a solar zenith angle of 60deg. The estimated uncertainty in the albedo is 3.5 x 10(exp -3) caused by the uncertainty in CERES-derived irradiances, uncertainty in VIRS-derived aerosol optical thicknesses, variations in ozone and water vapor, and variations in surface wind speed. The estimated uncertainty is similar in magnitude to the standard deviation of 0.003 that is derived from 72 areas divided by 20deg latitude by 20deg longitude grid boxes. The empirically estimated albedo is compared with the modeled albedo using a radiative transfer model combined with an ocean surface bidirectional reflectivity model. The modeled albedo with standard tropical atmosphere is 0.061 and 0.111 at the solar zenith angles of 10deg and 60deg, respectively. This empirically estimated albedo can be used to estimate the direct radiative effect of aerosols at the top of the atmosphere over oceans.

Kato, S.; Loeb, N. G.; Rutledge, C. K.

2002-01-01

 
 
 
 
121

Clouds and the Earth's Radiant Energy System (CERES) algorithm theoretical basis document. volume 2; Geolocation, calibration, and ERBE-like analyses (subsystems 1-3)  

Science.gov (United States)

The theoretical bases for the Release 1 algorithms that will be used to process satellite data for investigation of the Clouds and Earth's Radiant Energy System (CERES) are described. The architecture for software implementation of the methodologies is outlined. Volume 2 details the techniques used to geolocate and calibrate the CERES scanning radiometer measurements of shortwave and longwave radiance to invert the radiances to top-of-the-atmosphere (TOA) and surface fluxes following the Earth Radiation Budget Experiment (ERBE) approach, and to average the fluxes over various time and spatial scales to produce an ERBE-like product. Spacecraft ephemeris and sensor telemetry are used with calibration coefficients to produce a chronologically ordered data product called bidirectional scan (BDS) radiances. A spatially organized instrument Earth scan product is developed for the cloud-processing subsystem. The ERBE-like inversion subsystem converts BDS radiances to unfiltered instantaneous TOA and surface fluxes. The TOA fluxes are determined by using established ERBE techniques. Hourly TOA fluxes are computed from the instantaneous values by using ERBE methods. Hourly surface fluxes are estimated from TOA fluxes by using simple parameterizations based on recent research. The averaging process produces daily, monthly-hourly, and monthly means of TOA and surface fluxes at various scales. This product provides a continuation of the ERBE record.

Wielicki, B. A. (Principal Investigator); Barkstrom, B. R. (Principal Investigator); Charlock, T. P.; Baum, B. A.; Green, R. N.; Minnis, P.; Smith, G. L.; Coakley, J. A.; Randall, D. R.; Lee, R. B., III

1995-01-01

122

Clouds and the Earth's Radiant Energy System (CERES) Algorithm Theoretical Basis Document. Volume 3; Cloud Analyses and Determination of Improved Top of Atmosphere Fluxes (Subsystem 4)  

Science.gov (United States)

The theoretical bases for the Release 1 algorithms that will be used to process satellite data for investigation of the Clouds and Earth's Radiant Energy System (CERES) are described. The architecture for software implementation of the methodologies is outlined. Volume 3 details the advanced CERES methods for performing scene identification and inverting each CERES scanner radiance to a top-of-the-atmosphere (TOA) flux. CERES determines cloud fraction, height, phase, effective particle size, layering, and thickness from high-resolution, multispectral imager data. CERES derives cloud properties for each pixel of the Tropical Rainfall Measuring Mission (TRMM) visible and infrared scanner and the Earth Observing System (EOS) moderate-resolution imaging spectroradiometer. Cloud properties for each imager pixel are convolved with the CERES footprint point spread function to produce average cloud properties for each CERES scanner radiance. The mean cloud properties are used to determine an angular distribution model (ADM) to convert each CERES radiance to a TOA flux. The TOA fluxes are used in simple parameterization to derive surface radiative fluxes. This state-of-the-art cloud-radiation product will be used to substantially improve our understanding of the complex relationship between clouds and the radiation budget of the Earth-atmosphere system.

1995-01-01

123

Angular Distribution Models for Top-of-Atmosphere Radiative Flux Estimation from the Clouds and the Earth's Radiant Energy System Instrument on the Terra Satellite. Part 1; Methodology  

Science.gov (United States)

The Clouds and Earth's Radiant Energy System (CERES) provides coincident global cloud and aerosol properties together with reflected solar, emitted terrestrial longwave and infrared window radiative fluxes. These data are needed to improve our understanding and modeling of the interaction between clouds, aerosols and radiation at the top of the atmosphere, surface, and within the atmosphere. This paper describes the approach used to estimate top-of-atmosphere (TOA) radiative fluxes from instantaneous CERES radiance measurements on the Terra satellite. A key component involves the development of empirical angular distribution models (ADMs) that account for the angular dependence of Earth's radiation field at the TOA. The CERES Terra ADMs are developed using 24 months of CERES radiances, coincident cloud and aerosol retrievals from the Moderate Resolution Imaging Spectroradiometer (MODIS), and meteorological parameters from the Global Modeling and Assimilation Office (GMA0) s Goddard Earth Observing System DAS (GEOS-DAS V4.0.3) product. Scene information for the ADMs is from MODIS retrievals and GEOS-DAS V4.0.3 properties over ocean, land, desert and snow, for both clear and cloudy conditions. Because the CERES Terra ADMs are global, and far more CERES data is available on Terra than was available from CERES on the Tropical Rainfall Measuring Mission (TRMM), the methodology used to define CERES Terra ADMs is different in many respects from that used to develop CERES TRMM ADMs, particularly over snow/sea-ice, under cloudy conditions, and for clear scenes over land and desert.

Loeb, N. G.; Kato, S.; Loukachine, K.; Smith, N. M.

2004-01-01

124

A search for space energy alternatives  

Science.gov (United States)

This paper takes a look at a number of schemes for converting radiant energy in space to useful energy for man. These schemes are possible alternatives to the currently most studied solar power satellite concept. Possible primary collection and conversion devices discussed include the space particle flux devices, solar windmills, photovoltaic devices, photochemical cells, photoemissive converters, heat engines, dielectric energy conversion, electrostatic generators, plasma solar collectors, and thermionic schemes. Transmission devices reviewed include lasers and masers.

Gilbreath, W. P.; Billman, K. W.

1978-01-01

125

Solar collector manufacturing activity, 1992  

Energy Technology Data Exchange (ETDEWEB)

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

1993-11-09

126

Thermal model of attic systems with radiant barriers  

Energy Technology Data Exchange (ETDEWEB)

This report summarizes the first phase of a project to model the thermal performance of radiant barriers. The objective of this phase of the project was to develop a refined model for the thermal performance of residential house attics, with and without radiant barriers, and to verify the model by comparing its predictions against selected existing experimental thermal performance data. Models for the thermal performance of attics with and without radiant barriers have been developed and implemented on an IBM PC/AT computer. The validity of the models has been tested by comparing their predictions with ceiling heat fluxes measured in a number of laboratory and field experiments on attics with and without radiant barriers. Cumulative heat flows predicted by the models were usually within about 5 to 10 percent of measured values. In future phases of the project, the models for attic/radiant barrier performance will be coupled with a whole-house model and further comparisons with experimental data will be made. Following this, the models will be utilized to provide an initial assessment of the energy savings potential of radiant barriers in various configurations and under various climatic conditions. 38 refs., 14 figs., 22 tabs.

Wilkes, K.E.

1991-07-01

127

New Angular Distribution Models for Shortwave and Longwave Top-of-Atmosphere Radiative Flux Estimation From the Clouds and the Earth's Radiant Energy System Instrument  

Science.gov (United States)

The Clouds and the Earth's Radiant Energy System (CERES) provides highly accurate top-of-atmosphere (TOA) shortwave (SW), longwave (LW) and window (WN) radiance measurements and radiative flux estimates together with coincident cloud and aerosol properties inferred from the Moderate Resolution Imaging Spectrometer (MODIS). These data are needed to investigate the critical role that clouds and aerosols play in modulating the radiative energy flow within the Earth-atmosphere system. To estimate TOA fluxes from measured CERES radiances, one must account for the angular dependence in the radiance field, which is a strong function of the physical and optical characteristics of the scene (e.g. surface type, cloud fraction, cloud/aerosol optical depth, cloud phase), as well as the illumination angle. Because the CERES instrument can rotate in azimuth as it scans in elevation, it is acquires data over a wide range of angles. Consequently, one can construct angular distribution models (ADMs) for radiance-to-flux conversion from the CERES measurements. Furthermore, since CERES and MODIS are on the same spacecraft, the ADMs can be derived as a function of MODIS-based scene type parameters that have a strong influence on radiance anisotropy. This presentation provides a brief overview of the methodology and validation results for a new set of global CERES ADMs developed from two years of CERES measurements on the Terra spacecraft. The uncertainty in regional monthly mean SW and LW TOA fluxes from the new ADMs is less than 0.5 W m-2 based on comparisons with TOA fluxes evaluated by direct integration of the measured radiances. From multiangle CERES radiance measurements, instantaneous TOA flux errors are estimated to be CERES ADMs are a factor of 2-5 smaller than those based on ADMs developed during the Earth Radiation Budget Experiment (ERBE). The improved accuracy in the Terra radiative fluxes is essential in studies that examine radiative forcing by cloud type and studies that combine TOA fluxes with surface measurements from specific locations.

Loeb, N. G.; Kato, S.; Loukachine, K.; Manalo-Smith, N.

2003-12-01

128

40 CFR Appendix A to Subpart F of... - List of Qualified Energy Conservation Measures, Qualified Renewable Generation, and Measures...  

Science.gov (United States)

...core door replacement • Radiant barriers • Window vent...Multiple chiller control • Radiant heating • Evaporative...Manual fan switches • Energy saving exhaust hood • Night flushing • Spot radiant heating • Terminal...

2010-07-01

129

BigHorn Home Improvement Center Energy Performance: Preprint  

Energy Technology Data Exchange (ETDEWEB)

This is one of the nation's first commercial building projects to integrate extensive high-performance design into a retail space. The extensive use of natural light, combined with energy-efficient electrical lighting design, provides good illumination and excellent energy savings. The reduced lighting loads, management of solar gains, and cool climate allow natural ventilation to meet the cooling loads. A hydronic radiant floor system, gas-fired radiant heaters, and a transpired solar collector deliver heat. An 8.9-kW roof-integrated photovoltaic (PV) system offsets a portion of the electricity.

Deru, M.; Pless, S.; Torcellini, P.

2006-04-01

130

Analyses of On-orbit Determinations of the Clouds and the Earth Radiant Energy System (CERES) Thermistor Bolometer Sensor Zero-radiance Effects  

Science.gov (United States)

The Clouds and Earth's Radiant Energy System (CERES) missions were designed to measure broadband earth-reflected shortwave solar (0.3 micrometers to less than 5.0 micrometers) and earth-emitted longwave (5.0 micrometers to greater than 100 micrometers) radiances as well as earth-emitted narrow-band radiances in the water vapor window region between 8 micrometers and 12 micrometers. However, the CERES scanning thermistor bolometer sensor zero-radiance offsets were found to vary as much as 1.0 Wm (exp -2) sr (exp -1) with the scan angle measurement geometry due to gravitational forces and systematic electronic noise. To minimize the gravitational effects, the Tropical Rainfall Measuring Mission (TRMM) Spacecraft CERES sensors' offsets were derived on-orbit as functions of scan elevation and azimuth angles from the January 7-8, 1998 radiometric observations of deep cold space, representative of a 3 K blackbody. In this paper, the TRMM/CERES six orbit data base of on-orbit derived offsets is presented and analyzed to define the sampling requirements for the CERES sensors located on the Earth Science Enterprise (ESE) Terra Spacecraft and on the Earth Observing System (EOS) Afternoon (PM-1) Spacecraft, scheduled for launches in 1999 and 2000, respectively. Analyses of the TRMM/CERES shortwave sensor earth radiance measurements indicate that offsets can be determined on-orbit at the plus or minus 0.02 Wm (exp -2) sr (exp -1) precision level. Offset measuring techniques and sampling requirements are discussed for the TRMM and ESE missions. Ground, pre-launch Terra CERES cross-track scan offsets are presented and described which were measured as a function of scan angle.

Lee, Robert B., III; Thomas, Susan; Priestley, Kory J.; Barkstrom, Bruce R.; Paden, Jack; Pandey, Dhirendra K.; Smith, G. Louis; Al-hajjah, Aiman; Wilson, Robert S.

1999-01-01

131

Sensor performance of Clouds and the Earth's Radiant Energy System (CERES) instruments aboard EOS Terra and Aqua spacecraft based on post-launch calibration studies  

Science.gov (United States)

Clouds and the Earth's Radiant Energy System (CERES) instruments were designed to measure the reflected shortwave and emitted longwave radiances of the Earth's radiation budget and to investigate the cloud interactions with global radiances for the long-term monitoring of Earth's climate. The three scanning thermistor bolometers measure the broadband radiances in the shortwave (0.3 to 5.0 micrometer), total (0.3 to >100 micrometer) and 8 - 12 micrometer water vapor window regions. Four CERES instruments (Flight Models1 through 4) are flying aboard EOS Terra and Aqua platforms with two instruments aboard each spacecraft. The post launch calibration of CERES sensors are carried out using the internal calibration module (ICM) comprising of blackbody sources and quartz-halogen tungsten lamp, and a solar diffuser plate known as the Mirror Attenuator Mosaic (MAM). The ICM calibration results are instrumental in understanding the shift in CERES sensors' gains after launch from the pre-launch determined values. Several validation studies are also conducted with the CERES measurements to monitor the behavior of the sensors in various spectral regions. In addition to the broadband response changes derived from the on-board blackbody and the tungsten lamp, the shortwave and the total sensors show further drop in responsivity in the UV spectral region that were brought to light through validation studies. Further analyses were performed to correct for these response changes at all spectral regions. This paper reports the sensor response changes that were determined with the on-board calibration sources and the investigation of the additional factors that influence the performance of the CERES sensors in orbit.

Thomas, Susan; Priestley, K. J.; Hess, P. C.; Wilson, R. S.; Avery, M. A.; Walikainen, D. R.; Szewczyk, Z. P.; Cooper, D. L.; Shankar, M.

2009-08-01

132

Top-of-Atmosphere Direct Radiative Effect of Aerosols over the Tropical Oceans from the Clouds and the Earth's Radiant Energy System (CERES) Satellite Instrument.  

Science.gov (United States)

Nine months of the Clouds and the Earth's Radiant Energy System (CERES)/Tropical Rainfall Measuring Mission (TRMM) broadband fluxes combined with the TRMM visible infrared scanner (VIRS) high-resolution imager measurements are used to estimate the daily average direct radiative effect of aerosols for clear-sky conditions over the tropical oceans. On average, aerosols have a cooling effect over the Tropics of 4.6 ± 1 W m-2. The magnitude is 2 W m-2 smaller over the southern tropical oceans than it is over northern tropical oceans. The direct effect derived from CERES is highly correlated with coincident aerosol optical depth () retrievals inferred from 0.63-m VIRS radiances (correlation coefficient of 0.96). The slope of the regression line is 32 W m-2 -1 over the equatorial Pacific Ocean, but changes both regionally and seasonally, depending on the aerosol characteristics. Near sources of biomass burning and desert dust, the aerosol direct effect reaches 25 to 30 W m-2. The direct effect from CERES also shows a dependence on wind speed. The reason for this dependence is unclear-it may be due to increased aerosol (e.g., sea-salt or aerosol transport) or increased surface reflection (e.g., due to whitecaps). The uncertainty in the tropical average direct effect from CERES is 1 W m-2 (20%) due mainly to cloud contamination, the radiance-to-flux conversion, and instrument calibration. By comparison, uncertainties in the direct effect from the Earth Radiation Budget Experiment (ERBE) and CERES `ERBE-like' products are a factor of 3-5 times larger.

Loeb, Norman G.; Kato, Seiji

2002-06-01

133

Influence of radiant energy exchange on the determination of convective heat transfer rates to Orbiter leeside surfaces during entry  

Science.gov (United States)

Temperatures measured at the aerodynamic surface of the Orbiter's thermal protection system (TPS), and calorimeter measurements, are used to determine heating rates to the TPS surface during atmospheric entry. On the Orbiter leeside, where convective heating rates are low, it is possible that a significant portion of the total energy input may result from solar radiation, and for the wing, cross radiation from the hot (relatively) Orbiter fuselage. In order to account for the potential impact of these sources, values of solar- and cross-radiation heat transfer are computed, based upon vehicle trajectory and attitude information and measured surface temperatures. Leeside heat-transfer data from the STS-2 mission are presented, and the significance of solar radiation and fuselage-to-wing cross-radiation contributions to total energy input to Orbiter leeside surfaces is assessed.

Throckmorton, D. A.

1982-01-01

134

Energy collectors, solar energy collectors in particular  

Energy Technology Data Exchange (ETDEWEB)

A wave profile is placed between the inner insulating wall and an outer radiation transmitting part. Thus ducts are formed which are open to indoor or outdoor air respectively. The construction can also function as heat exchanger.

Onnela, H.

1985-08-12

135

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.)

136

Ground calibrations of the Clouds and the Earth's Radiant Energy System (CERES) instrument for the tropical rainfall measuring mission (TRMM)  

Science.gov (United States)

Clouds and the Earth's radiation energy system (CERES), a key experiment in the Earth observing system (EOS), is designed to measure the reflected shortwave and the emitted longwave radiances from Earth and its atmosphere. The CERES instrument consists of a scanning thermistor bolometer package with built in flight calibration systems. The first CERES instrument is scheduled for launch in 1997 aboard the joint National Aeronautics and Space Administration (NASA) and Japanese National Space Development Agency (NASDA) tropical rainfall measuring mission (TRMM) spacecraft. The laboratory calibrations of the instrument were conducted in the TRW vacuum facilities which are equipped with blackbodies, a cryogenically cooled transfer active-cavity radiometer, shortwave reference source, solar simulator and a constant radiance reference source. This paper describes the calibration facility and the calibration procedures for the CERES instrument.

Thomas, Susan; Lee, Robert B., III; Pandey, Dhirendra K.; Wilson, Robert S.; Bush, Kathryn A.; Paden, Jack; Lee, K. P.; Bolden, William C.

1996-11-01

137

Optical Sensors for Planetary Radiant Energy (OSPREy): Calibration and Validation of Current and Next-Generation NASA Missions  

Science.gov (United States)

A principal objective of the Optical Sensors for Planetary Radiance Energy (OSPREy) activity is to establish an above-water radiometer system as a lower-cost alternative to existing in-water systems for the collection of ground-truth observations. The goal is to be able to make high-quality measurements satisfying the accuracy requirements for the vicarious calibration and algorithm validation of next-generation satellites that make ocean color and atmospheric measurements. This means the measurements will have a documented uncertainty satisfying the established performance metrics for producing climate-quality data records. The OSPREy approach is based on enhancing commercial-off-the-shelf fixed-wavelength and hyperspectral sensors to create hybridspectral instruments with an improved accuracy and spectral resolution, as well as a dynamic range permitting sea, Sun, sky, and Moon observations. Greater spectral diversity in the ultraviolet (UV) will be exploited to separate the living and nonliving components of marine ecosystems; UV bands will also be used to flag and improve atmospheric correction algorithms in the presence of absorbing aerosols. The short-wave infrared (SWIR) is expected to improve atmospheric correction, because the ocean is radiometrically blacker at these wavelengths. This report describes the development of the sensors, including unique capabilities like three-axis polarimetry; the documented uncertainty will be presented in a subsequent report.

Hooker, Stanford B.; Bernhard, Germar; Morrow, John H.; Booth, Charles R.; Comer, Thomas; Lind, Randall N.; Quang, Vi

2012-01-01

138

Comparison of Thermal Comfort by Radiant Heating and Convective Heating  

Directory of Open Access Journals (Sweden)

Full Text Available Currently, convective heating with a heat-pump system, which has high energy efficiency, is popular for room heating. However, it is possible that energy savings using convective heating can be further improved using heat pumps that service both occupied and unoccupied spaces. Moreover, convective heating increases vertical temperature gradients in a room; thus, it is hard to say whether occupants are being provided with sufficient thermal comfort. The purpose of this study is to compare the thermal comfort provided by both radiant and convective heating systems. In this study, a small office room was modeled, and then temperature and airflow distributions in the room were calculated by Computational Fluid Dynamics (CFD simulations using ESP-r (Environmental research simulation software. Furthermore, distributions of Standard Effective Temperatures (SET* were calculated using the air temperature distributions obtained from the CFD simulations, which allows us to compare the thermal comfort provided by convective heating with that provided by radiant heating. The results show that radiant heating can provide satisfactory thermal comfort, even when the room air temperature is low. However, thermal comfort also depends on the temperature of blowing air, and blowing air must reach occupied regions; thus, only radiant heating cannot circulate sufficient air. In contrast, convective heating increases vertical temperature gradients in a room. Therefore, rather than using only radiant or convective heating, it may be more effective to combine them efficiently.

Shigeru Imai

2015-01-01

139

Energy flow and thermal comfort in buildings : Comparison of radiant and air-based heating & cooling systems  

DEFF Research Database (Denmark)

Varme- og køleanlæg kan inddeles i to hovedkategorier: konvektive systemer (fx. aircondition, aktiv kølebaffel, fan-coils) og stråle køling/varme systemer. De to systemer har forskellige former for varmeoverførsel; den første er hovedsageligt baseret på konvektion, mens den anden er baseret på både stråling og konvektion. Strålevarmesystemer har den fordel at kunne gøre brug af lav kilder (dvs. opvarmning ved lave temperature og køling ved høje temperaturer) og dermed reducere bygningers primære energiforbrug. Der er imidlertid en mangel på viden om varmeoverførsel fra terminalen mod rummet og på de parametre, der påvirker anlæggenes ydelse. Derfor er der foretaget en sammenligning af komfortbetingelserne og energiforbruget for fire typer anlæg (aktiv kølebaflen, strålende gulv, væg og loft) for et typisk kontorlokale, både numerisk og eksperimentelt. Fra den stationære numerisk analyse og fuldskalaforsøgene er det observeret, at forskellen mellem de to typer anlæg primært skyldes ændringer ventilationstab. Ved lave ventilationstilskud (under 0,5 ACH), har stråle- og luftbaserede systemer samme energibehov. Ved højere ventilationstilskud er strålevarmesystemers energiforbrug lavere end de luftbaserede systemers på grund af den højere lufttemperatur. Ved 2 ACH kan en strålevægs energibesparelser vurderes til ca. 10 % sammenlignet med den aktive kølebaflen (med hensyn til leveret energi). Asymmetrien mellem luft og strålingstemperatur, lufttemperaturgradienten og den mulige kortslutning mellem indløb og udløb spiller en lige så vigtig rolle ved reduceringen af strålevæggens kølebehov sammenlignet med den aktive kølebaflen. Jo højere et luftskifte og jo højere, jo større er de opnåede besparelser med en strålekølesystem. Derfor har strålekølesystemet et stort potentiale for energibesparelser i bygninger med et højt ventilationskifte (fx butikker, togstation, industriel opbevaring ). Blandt strålesystemer er der kun observeret små forskelle i den påtænkte geometri. Kun hvis beboerne antages at sidde ned, kan den store vinkelforhold med gulvet føre til en reduktion af energibehovet for gulvkølesystemer. Disse konklusioner gælder for fler-etagers eller højisolerede bygninger (R > 5 m2.K/W). Når det drejer sig om en enetagers bygning med et lavt isoleringsniveau, er strålesystemers effektivitet lavere på grund af de større klimaskærmstab, og et luftbaseret system kan være mere energieffektivt end et stråleanlæg (med hensyn til leveret energi). Et tilsvarende globalt komfort niveau er blevet observeret for stråle- og luftbaserede systemer i både numeriske og eksperimentelle undersøgelser, men de forskellige anlæg opnåede ikke den samme ensartethed i rummet. Den aktive kølebaflen opnår teoretisk de mest ensartede komfortbetingelser (når der ses bort fra risikoen for træk) efterfulgt af kølelofter. De mindst ensartede betingelser blev opnået med det afkølede gulv, på grund af store forskelle mellem siddende og stående stilling. Lokale komfortbetingelser (strålingstemperaturasymetrien, lufttemperaturgradient, risiko for træk) er også blevet evalueret både teoretisk og numerisk, og der er ikke observeret ubehag ved normal kølekapacitet. Udover denne sammenlignende undersøgelse af forskellige anlæg, er sammenhængen mellem kølesystemer og interne konvektionsstrømme også blevet undersøgt eksperimentelt. Sammenligningen med eksisterende modeller påpegede specificiteten af eksisterende sammenhænge og begrænsningen i deres anvendelsesområder. På grund af forskelle i indblæsning stråle, har eksisterende korrelationer en tendens til at overvurdere konvektionsstrømningen, især ved loftet. To fremgangsmåder er således blevet testet for bedre at kunne forklare strømingsformer i definitionen af konvektion koefficienter. Ved den første fremgangsmåde blev lokale værdier af lufthastigheden anvendt til at evaluere konvektion ved loftet. En alternativ fremgangsmåde består i at inkludere et modificeret Archimedes tal i definitionen af ko

Le Dreau, Jerome

2014-01-01

140

Ultracapacitor current collector  

Science.gov (United States)

An ultracapacitor having two solid, nonporous current collectors, two porous electrodes separating the collectors, a porous separator between the electrodes and an electrolyte occupying the pores in the electrodes and separator. At least one of the current collectors comprises a conductive metal substrate coated with a metal nitride, carbide or boride coating.

Jerabek, Elihu Calfin (Glenmont, NY); Mikkor, Mati (Ann Arbor, MI)

2001-10-16

 
 
 
 
141

Enabling Continuity in Earth Radiation Budget Observations by application of a Rigorous Calibration and Validation Protocol to the Observations of the Clouds and the Earth’s Radiant Energy System (CERES) Instruments  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The goal of the Clouds and the Earth’s Radiant Energy System (CERES) program is to produce a long-term record of radiation budget at the top-of-atmosphere (TOA), within the atmosphere, and at the surface with consistent cloud and aerosol properties at climate accuracy. CERES consists of an integrated instrument-algorithm-validation science team that provides development of higher-level products (Levels 1-3) and investigations. It involves a high level of data fusion, merging inputs from 25 ...

Priestley, Kory; Thomas, Susan; Bullock, Audra; Smith, G. Louis

2013-01-01

142

Connectable solar air collectors  

Energy Technology Data Exchange (ETDEWEB)

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

Oestergaard Jensen, S.; Bosanac, M.

2002-02-01

143

A low-cost efficient and durable low-temperature solar collector  

Science.gov (United States)

The considered collector utilizes a material made of ethylene-propylene-diene-monomer (EPDM). This material has been used in solar systems to heat domestic water, pools, spas, and homes by radiant energy. EPDM or ethylene propylene rubber compounds are synthetic elastomers. EPDM elastomers combine superior ozone, good heat and oxygen resistance, and very good low temperature properties to produce a compound with excellent overall age resistance. The material is extruded into 4.4 inch wide mats. Each mat has six small tubes alternating with thin webbing. The absorber mat will adhere to any clean building surface with the use of thermosetting construction-grade mastic adhesive. Carbon black contained in the mat material acts to increase the solar absorptivity. Their low cost makes the elastomers commercially very attractive. The efficiency and durability of the material are discussed.

Odonnell, T. P.

144

Finding radiant-energy sources  

Science.gov (United States)

Antenna is scanned in orthogonal directions to pinpoint interfering sources. Satellite system locates ground-based microwave transmitter to accuracy of about 100 miles. When data on misalinement of satellite antenna boresight are used to correct antenna pointing, accuracy is improved to better than 70 miles.

Schaffer, G. J.

1978-01-01

145

Solar collectors for cooling applications  

Energy Technology Data Exchange (ETDEWEB)

Collector research projects funded by the R and D Branch for Heating and Cooling, Department of Energy, which have direct applicability as cooling machine prime movers, are described. Performance curves are given where they are available along with the development status and the market availability. (MHR)

Collier, R.K.

1978-01-01

146

Study of a biogas digester feed in energy by a solar-water heating collector  

International Nuclear Information System (INIS)

The socio-economic development which occurred to the XIXE and XXE centuries would have been impossible without energy. Indeed coal, oil, the nature gas and various other sources of energy were the world engine of the economy. Currently, energy is available in great quantity and remains relatively cheap. It makes it possible to many populations to enjoy very high levels of comfort, productivity and mobility. The access to these great quantities of energy and their exploitation is however unequally distributed between the areas and the countries. In Algeria in spite of the high contents in hydrocarbons, the supply fossil fuels (oil, natural gas) remains one of the major problems of the wedged areas and more particularly the mountainous areas and those of the south, which generated a consumption increased out of wood, a thorough degradation of the forests, an erosion of the grounds and a deterioration of the climate and environment. To meet the requirements in energy for our country, in order to ensure its perennity, to appreciably reduce local pollution and the effect of greenhouse, for the safeguarding of the environment, the prospecting and the development of new sources of energy were in particular undertaken the energy of the biomass and more precisely that provided by biogas. This largely available renewable energy, inexpensive and non-polluting in used to supplement non-renewable fossil energy. Energy production starting from the organic matt production starting from the organic matter of various origins: animal manure, under products of the food industry, mud of the stations of purification, household refuse..., by means of processes of anaerobic digestion in suitable digesters (for bio-methane production), will allow a better management of waste. a safeguarding of the environment and a development as well as a diversification of the energy resources (alternative energies). In addition, this organic matter, at the local level, will make it possible to produce energy at lower cost for cooking. the heating, the lighting and manure with high fertilising potential (stabilised mud) like amendments for the arable lands. The production of biogas could be regarded as an economic solution, decentralised and ecological with these problems through energy autonomy and a durable agricultural development of the rural zones. The bio-methane remains an energy ignored in Algeria, that in spite of several attempts at use which were undertaken since the Forties and even if it does not form part of our sociological cultural and economic traditions, it must represent the best solution to the already mentioned problems. Our study propose to produce bio-methane starting from the animal manure (dung of cows). For that an experimental device was designed and carried out. It consists of digester of 800 litters, of a gas meter bell of 600 litters, of a device of heating applied with a solar-fired heater which ensures a mesophile temperature to him and of a system of agitation of the substrate. The experimental study made it possible to optimize the process of production, for a domestic application and also to develop a system temperature control required at the entry of digester ranging between 25 and 40 degree centigrade. The model is quasi-autonomous. The achievement of this objective of research will make it possible, as we hope for it, to lay down a policy of digester installation of on a national scale.(Author)

147

A collector testbench for electron coolers  

International Nuclear Information System (INIS)

A new collector design for electron coolers was elaborated in the Karlsruhe electron cooling group at LEAR (CERN). For testing the performance of the collector a linear set-up was built with an electron beam of energies up to 20 keV and currents up to 1.25 A. In the present stage maximum collector perveance of 37 ?AV-3/2 can be obtained. Loss rates are well in the 10-5 region for collector perveances of ?25 ?AV-3/2. The collector was investigated in detail and a new type of computerized control and monitor system was tested based on a Macintosh Plus personal computer with a special interface for CAMAC and VME. (orig.)

148

Direct expansion solar collector and heat pump  

Science.gov (United States)

A hybrid heat pump/solar collector combination in which solar collectors replace the outside air heat exchanger found in conventional air-to-air heat pump systems is discussed. The solar panels ordinarily operate at or below ambient temperature, eliminating the need to install the collector panels in a glazed and insulated enclosure. The collectors simply consist of a flat plate with a centrally located tube running longitudinally. Solar energy absorbed by exposed panels directly vaporizes the refrigerant fluid. The resulting vapor is compressed to higher temperature and pressure; then, it is condensed to release the heat absorbed during the vaporization process. Control and monitoring of the demonstration system are addressed, and the tests conducted with the demonstration system are described. The entire heat pump system is modelled, including predicted performance and costs, and economic comparisons are made with conventional flat-plate collector systems.

1982-05-01

149

Controlled Production of Sub-Radiant States of a Diatomic Molecule in an Optical Lattice  

CERN Document Server

We report successful production of sub-radiant states of a two-atom system in a three-dimensional optical lattice starting from doubly occupied sites in a Mott insulator phase of a quantum gas of atomic ytterbium. We can selectively produce either sub-radiant 1g state or super-radiant 0u state by choosing the excitation laser frequency. The inherent weak excitation rate for the sub-radiant 1g state is overcome by the increased atomic density due to the tight-confinement in a three-dimensional optical lattice. Our experimental measurements of binding energies, linewidth, and Zeeman shift confirm observation of sub-radiant levels of the 1g state of the Yb_2 molecule.

Takasu, Yosuke; Takahashi, Yoshiro; Borkowski, Mateusz; Ciury?o, Roman; Julienne, Paul S

2012-01-01

150

On-orbit solar calibration methods using the Clouds and Earth's Radiant Energy System (CERES) in-flight calibration system: lessons learned  

Science.gov (United States)

The Clouds and Earth's Radiant Energy System (CERES) scanning thermistor bolometers measure earth-reflected solar and earth-emitted long-wave radiances, at the top- of-the-atmosphere. The bolometers measure the earth radiances in the broadband shortwave solar (0.3-5.0 microns) and total (0.3->100 microns) spectral bands as well as in the 8->12 microns water vapor window spectral band over geographical footprints as small as 10 kilometers at nadir. December 1999, the second and third set of CERES bolometers was launched on the Earth Observing Mission Terra Spacecraft. May 2003, the fourth and fifth set of bolometers was launched on the Earth Observing Mission Aqua Spacecraft. Recently, (October 2011) the sixth instrument was launched on the National Polar-orbiting Operational Environmental Satellite System Preparatory Project (Suomi NPP) Spacecraft. Ground vacuum calibrations define the initial count conversion coefficients that are used to convert the bolometer output voltages into filtered earth radiances. The mirror attenuator mosaic (MAM), a solar diffuser plate, was built into the CERES instrument package calibration system in order to define on-orbit shifts or drifts in the sensor responses. It followed a similar design as the Earth Radiation Budget Experiment (ERBE) scanners with improvements from lessons learned. The shortwave and shortwave part of the total-wave sensors are calibrated using the solar radiances reflected from the MAM's. Each MAM consists of baffle-solar diffuser plate systems, which guide incoming solar radiances into the instrument fields of view of the shortwave and total wave sensor units. The MAM diffuser reflecting type surface consists of an array of spherical aluminum mirror segments, which are separated by a Merck Black A absorbing surface, over-coated with SIOx (SIO2 for PFM). Thermistors are located within each MAM plate and the total channel baffle. The CERES MAM is designed to yield calibration precisions approaching .5 percent for the total and shortwave detectors. The Terra FM1 and FM2 shortwave channels and the FM1 and FM2 total channels MAM calibration systems showed shifts in their solar calibrations of 1.5, 2.5, 1.5 and 6 percent, respectively within the first year. The Aqua FM3, and FM4 shortwave channels and the FM3 and FM4 total channels MAM calibration systems showed shifts in their solar calibrations of 1.0, 1.2, 2.1 and .8 percent, respectively within the first year. A possible explanation has attributed the MAM reflectance change to on-orbit solar ultraviolet/atomic oxygen/out-gassing induced chemical changes to the SIOx coated MAM assembly during ram and solar exposure. There is also changes to the sensor telescope shortwave filters as well as the Total channel mirrors and/or sensors. The Soumi NPP FM5 is still after 2.5 years displaying a stability of less than .5 percent. In this presentation, lessons learned from the ERBE MAM and application of knowledge of how the space environment affected the CERES FM1-4 solar calibrations will be presented along with on-orbit measurements for the thirteen years the CERES instruments have been on-orbit.

Wilson, Robert S.; Priestley, Kory J.; Thomas, Susan; Hess, Phillip; Shankar, Mohan; Smith, Nathaniel; Szewczyk, Peter

2013-09-01

151

Transpired Solar Collector at NREL's Waste Handling Facility Uses Solar Energy to Heat Ventilation Air (Fact Sheet)  

Energy Technology Data Exchange (ETDEWEB)

The transpired solar collector was installed on NREL's Waste handling Facility (WHF) in 1990 to preheat ventilation air. The electrically heated WHF was an ideal candidate for the this technology - requiring a ventilation rate of 3,000 cubic feet per meter to maintain safe indoor conditions.

2010-09-01

152

Correlation analysis of infrared radiant intensity between hyperplastic breast tissue and tongue surface in patients with hyperplasia of mammary glands  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Objective: To establish a supplementary diagnostic indicator (infrared radiant intensity) in tongue diagnosis of traditional Chinese medicine (TCM) in patients with hyperplasia of mammary glands through correlation analysis of infrared radiant intensity between hyperplastic breast tissue and tongue surface.Methods: Infrared radiant intensity of the hyperplastic breast tissue and different points on tongue surface in 20 cases of hyperplasia of mammary glands with liver-energy stagnation and ph...

Zhang, Zhi-feng

2007-01-01

153

Short-Term Solar Collector Power Forecasting  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper describes a new approach to online forecasting of power output from solar thermal collectors. The method is suited for online forecasting in many applications and in this paper it is applied to predict hourly values of power from a standard single glazed large area flat plate collector. The method is applied for horizons of up to 42 hours. Solar heating systems naturally come with a hot water tank, which can be utilized for energy storage also for other energy source...

Bacher, Peder; Madsen, Henrik; Perers, Bengt

2011-01-01

154

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2011-04-15

155

Comparison thermal properties of flate plate and heat pipe solar collectors  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This specialist work deals with different types of solar water heat collectors. I have compared and analysed Flat plate solar collectors and Heat pipe solar collectors. Measurements were made on Heat pipe solar collectors system and are presented in the specialist work. The goal of this specialist work is to prove the economy of solar system with regard to the heating energy costs.

Kopac?, Klemen

2013-01-01

156

Combination photovoltaic/thermal solar collectors for residential applications  

Science.gov (United States)

The design, development and fabrication of combination photovoltaic/thermal (PV/T) solar collectors for residential applications is reported. Liquid and air cooled, flat-plate collectors were designed in which close packed silicon solar cells absorbed the bulk of the solar radiation to provide both thermal and electrical energy. Air cooled collector cells had front and back open grid metallization to allow infrared radiation to pass through to a separate highly absorbing surface. Liquid cooled collector cells had solid back metallization optimized for infrared absorption. Details of the optical, electrical, thermal and mechanical characteristics of these collectors are presented.

Younger, P. R.; Kreisman, W. S.; Nowlan, M. J.; Solomon, S. J.; Strong, S. J.

157

An Inexpensive Fraction Collector.  

Science.gov (United States)

Describes the construction of a low-cost (about $70.00) alternative to the commercial fraction collector. Outlines the separate parts of the collector and provides a schematic of electronic circuitry of the instrument. Lists special items required for the development of this project. (TW)

Fisher, Tom Lyons; McGinnis, James S.

1986-01-01

158

Evaluación energética de un colector solar de placa plana de doble cubierta / Energy assessment of a double cover flat-plate solar collector  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish En este artículo se establece la incidencia de la relación de aspecto (razón entre la longitud y ancho de un colector de área constante) sobre la eficiencia térmica de un colector solar de placa plana que utiliza doble cubierta transparente para el calentamiento de aire. Este estudio se realiza desd [...] e dos enfoques: el primero utiliza un modelo físico-matemático a partir de los balances de energía del colector, y el segundo utiliza un prototipo con su respectiva instrumentación para calcular su rendimiento de manera experimental. El colector está compuesto por una estructura en madera, una doble cubierta de vidrio transparente, una placa absorbedora de radiación solar y un ventilador para extraer el aire calentado. Para calcular el rendimiento se registraron de manera automática datos de temperatura, radiación solar y flujo másico de aire; durante aproximadamente 6 horas por varios días y bajo distintas condiciones climáticas de la ciudad de Montería, Córdoba (Colombia). En general se encontró, para un área constante del colector, que la eficiencia térmica de este aumenta cuando la relación de aspecto aumenta y que el modelo teórico se ajusta de manera aceptable con los resultados experimentales. Abstract in english This study establishes the effect of the aspect ratio (ratio between length and width of a constant collector area) on the thermal efficiency of a flat-plate solar collector that uses a double cover for air heating. The analysis has two approaches: first, using a physical-mathematical model that dev [...] elop a steady state analysis from a collector energy balance and the second, using an instrumented prototype to calculate its performance in experimental way. The collector configuration consists in a wood structure, a double glass cover, an absorber plate of solar radiation and blower to extract the heated air. To calculate the performance temperature data, solar radiation and mass flow of air were automatically recorded for about 6 hours for several days and under different weather conditions in the city of Montería, Cordoba. In general it was found, for a constant collector area, where the thermal efficiency increases when the aspect ratio increases and that the theoretical model fits in an acceptable way with the experimental results.

Adrián Enrique, Ávila Gómez; Jorge Mario, Mendoza Fandiño; Julio Fernando, Beltrán Sarmiento.

2010-06-01

159

Mass flow, pressure drop, and leakage dependent modeling and characterization of solar air collectors  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In comparison to liquid collectors, the thermal efficiency of air collectors strongly depends on the mass flow, and often air collectors can be leaky. Further, for efficient system operation, the air collector’s mass flow will be chosen regarding the auxiliary power demand of the fan caused by the pressure drop of the system. In this work the interdependency between thermal and hydraulic behavior and the resulting primary energy demand will be explained. Moreover, suitable mass flow depende...

Welz, C.; Maurer, C.; Lauro, P. Di; Stryi-hipp, G.; Hermann, M.

2014-01-01

160

Advanced radiant combustion system. Final report, September 1989--September 1996  

Energy Technology Data Exchange (ETDEWEB)

Results of the Advanced Radiant Combustion System (ARCS) project are presented in this report. This work was performed by Alzeta Corporation as prime contractor under a contract to the U.S. Department of Energy Office of Industrial Technologies as part of a larger DOE program entitled Research Program for Advanced Combustion Systems. The goals of the Alzeta ARCS project were to (a) Improve the high temperature performance characteristics of porous surface ceramic fiber burners, (b) Develop an Advanced Radiant Combustion System (ARCS) that combines combustion controls with an advanced radiant burner, and (c) Demonstrate the advanced burner and controls in an industrial application. Prior to the start of this project, Alzeta had developed and commercialized a porous surface radiant burner, the Pyrocore{trademark} burner. The product had been commercially available for approximately 5 years and had achieved commercial success in a number of applications ranging from small burners for commercial cooking equipment to large burners for low temperature industrial fluid heating applications. The burner was not recommended for use in applications with process temperatures above 1000{degrees}F, which prevented the burner from being used in intermediate to high temperature processes in the chemical and petroleum refining industries. The interest in increasing the maximum use temperature of the burner was motivated in part by a desire to expand the number of applications that could use the Pyrocore product, but also because many of the fluid sensitive heating applications of interest would benefit from the distributed flux characteristic of porous surface burners. Background information on porous surface radiant burners, and a discussion of advantages that would be provided by an improved product, are presented in Section 2.

Sullivan, J.D.; Carswell, M.G.; Long, F.S.

1996-09-01

 
 
 
 
161

Internal absorber solar collector  

Science.gov (United States)

Thin solar collecting panels are described made from arrays of small rod collectors consisting of a refracting dielectric rod lens with an absorber imbedded within it and a reflecting mirror coated on the back side of the dielectric rod. Non-tracking collector panels on vertical walls or roof tops receive approximately 90% of solar radiation within an acceptance zone 60.degree. in elevation angle by 120.degree. or more in the azimuth sectors with a collector concentration ratio of approximately 3.0. Miniaturized construction of the circular dielectric rods with internal absorbers reduces the weight per area of glass, plastic and metal used in the collector panels. No external parts or insulation are needed as heat losses are low due to partial vacuum or low conductivity gas surrounding heated portions of the collector. The miniature internal absorbers are generally made of solid copper with black selective surface and the collected solar heat is extracted at the collector ends by thermal conductivity along the absorber rods. Heat is removed from end fittings by use of liquid circulants. Several alternate constructions are provided for simplifying collector panel fabrication and for preventing the thermal expansion and contraction of the heated absorber or circulant tubes from damaging vacuum seals. In a modified version of the internal absorber collector, oil with temperature dependent viscosity is pumped through a segmented absorber which is now composed of closely spaced insulated metal tubes. In this way the circulant is automatically diverted through heated portions of the absorber giving higher collector concentration ratios than theoretically possible for an unsegmented absorber.

Sletten, Carlyle J. (106 Nagog Hill Rd., Acton, MA 01720); Herskovitz, Sheldon B. (88 Hammond St., Acton, MA 01720); Holt, F. S. (46 Emerson Rd., Winchester, MA 01890); Sletten, E. J. (Chestnut Hill Rd. R.F.D. Rte. #4, Amherst, NH 03031)

1981-01-01

162

SOLAR NANTENNA ELECTROMAGNETIC COLLECTORS  

Energy Technology Data Exchange (ETDEWEB)

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.

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

2008-08-01

163

City sewer collectors biocorrosion  

Science.gov (United States)

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

Ksia¸?ek, Mariusz

2014-12-01

164

A dynamic advanced radiation exchange module for use in simulation of spaces with radiant systems  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The surface temperature of radiant systems can be significantly different than the temperature of other room surfaces. Therefore, radiation heat exchange often becomes the dominant mode of heat transfer. To accurately predict the surface temperature of radiant systems, it becomes necessary to model radiative heat fluxes in detail, in order to evaluate the thermal environment in terms of energy and comfort. In this study, a detailed thermal simulation module was developed for prediction of tra...

Rohan, Devin Matthew

2011-01-01

165

Radiant Heat Transfer in Reusable Surface Insulation  

Science.gov (United States)

During radiant testing of mullite panels, temperatures in the insulation and support structure exceeded those predicted on the basis of guarded hot plate thermal conductivity tests. Similar results were obtained during arc tunnel tests of mullite specimens. The differences between effective conductivity and guarded hot plate values suggested that radiant transfer through the mullite was occurring. To study the radiant transport, measurements were made of the infrared transmission through various insulating materials and fibers of interest to the shuttle program, using black body sources over the range of 780 to 2000 K. Experimental data were analyzed and scattering coefficients were derived for a variety of materials, fiber diameters, and source temperature.

Hughes, T. A.; Linford, R. M. F.; Chmitt, R. J.; Christensen, H. E.

1973-01-01

166

ADVANCED HYBRID PARTICULATE COLLECTOR  

Energy Technology Data Exchange (ETDEWEB)

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.

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

2000-12-01

167

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.

168

Exergy metrication of radiant panel heating and cooling with heat pumps  

International Nuclear Information System (INIS)

Highlights: ? Rational Exergy Management Model analytically relates heat pumps and radiant panels. ? Heat pumps driven by wind energy perform better with radiantpanels. ? Better CO2 mitigation is possible with wind turbine, heat pump, radiant panel combination. ? Energy savings and thermo-mechanical performance are directly linked to CO2 emissions. - Abstract: Radiant panels are known to be energy efficient sensible heating and cooling systems and a suitable fit for low-exergy buildings. This paper points out the little known fact that this may not necessarily be true unless their low-exergy demand is matched with low-exergy waste and alternative energy resources. In order to further investigate and metricate this condition and shed more light on this issue for different types of energy resources and energy conversion systems coupled to radiant panels, a new engineering metric was developed. Using this metric, which is based on the Rational Exergy Management Model, true potential and benefits of radiant panels coupled to ground-source heat pumps were analyzed. Results provide a new perspective in identifying the actual benefits of heat pump technology in curbing CO2 emissions and also refer to IEA Annex 49 findings for low-exergy buildings. Case studies regarding different scenarios are compared with a base case, which comprises a radiant panel system connected to a natural gas-fired condensing boiler in heating and a grid powe boiler in heating and a grid power-driven chiller in cooling. Results show that there is a substantial CO2 emission reduction potential if radiant panels are optimally operated with ground-source heat pumps driven by renewable energy sources, or optimally matched with combined heat and power systems, preferably running on alternative fuels.

169

Radiant cooling in US office buildings: Towards eliminating the perception of climate-imposed barriers  

Energy Technology Data Exchange (ETDEWEB)

Much attention is being given to improving the efficiency of air-conditioning systems through the promotion of more efficient cooling technologies. One such alternative, radiant cooling, is the subject of this thesis. Performance information from Western European buildings equipped with radiant cooling systems indicates that these systems not only reduce the building energy consumption but also provide additional economic and comfort-related benefits. Their potential in other markets such as the US has been largely overlooked due to lack of practical demonstration, and to the absence of simulation tools capable of predicting system performance in different climates. This thesis describes the development of RADCOOL, a simulation tool that models thermal and moisture-related effects in spaces equipped with radiant cooling systems. The thesis then conducts the first in-depth investigation of the climate-related aspects of the performance of radiant cooling systems in office buildings. The results of the investigation show that a building equipped with a radiant cooling system can be operated in any US climate with small risk of condensation. For the office space examined in the thesis, employing a radiant cooling system instead of a traditional all-air system can save on average 30% of the energy consumption and 27% of the peak power demand due to space conditioning. The savings potential is climate-dependent, and is larger in retrofitted buildings than in new construction. This thesis demonstrates the high performance potential of radiant cooling systems across a broad range of US climates. It further discusses the economics governing the US air-conditioning market and identifies the type of policy interventions and other measures that could encourage the adoption of radiant cooling in this market.

Stetiu, C.

1998-01-01

170

Quality control of radiant heaters  

Science.gov (United States)

Based on infrared thermography, a non-destructive testing and evaluation (NDT&E) procedure is proposed for defects assessment on radiant heaters. Under a short electrical excitation, an infrared camera captures the cooling process of the heaters. Breaking the thermographic images down not only makes easiest the location of defects but it also allows their classification. Several kinds of defects have been taken into account: lack of supporting brackets; defects originated by a deficiency in the heating material; those from an excess of heating material; and those parts of the heating elements which are in wrong contact (non-contact or semi-buried) with the substrate. Each kind of analyzed defect has a different thermal history after the electrical excitation because of its nature. By means of computer vision techniques, the defects can be spatially located. The "chain code" was employed to follow the pattern of the heating element and so concentrate the analysis in points belonging to the pattern. A good agreement with analysis made under human's criteria is achieved. However, using infrared cameras and processing the data with computer vision algorithms allows controlling in-site the quality of the product without any subjectivity. So, the heaters manufacturing industry could come along with the implementation of this automatic detection procedure. Experimental results that validate the proposed method will be presented and discussed in this paper.

González, Daniel A.; Madruga, Francisco J.; Quintela, María Á.; López-Higuera, José M.

2005-09-01

171

High-performance vacuum tubes for more energy efficiency. Building-integrated CPC vacuum tube collectors unite several functions.; Hochleistungs-Vakuumroehren fuer mehr Energieeffizienz. Gebaeudeintegrierte CPC-Vakuumroehren-Kollektoren vereinen mehrere Funktionen  

Energy Technology Data Exchange (ETDEWEB)

The performance of solar collectors primarily contributes to increased efficiency and reduced operating costs of solar thermal systems. With the use of building-integrated CPC vacuum tube collectors an extremely high energy yield is achieved on a smaller collector gross area. As a building-integrated system solution the CPC facade provide panels in addition to its use as spandrel panels within the glazed buildings not only an architectural design element, but unite as a multifunctional component for several functions. [German] Die Leistungsfaehigkeit der Solarkollektoren traegt primaer zur Effizienzsteigerung und Reduzierung der Betriebskosten einer Solarthermieanlagen bei. Mit dem Einsatz gebaeudeintegrierter CPC-Vakuumroehrenkollektoren wird auf einer kleineren Kollektorbruttoflaeche ein extrem hoher Energieertrag erreicht. Als gebaeudeintegrierte Systemloesung bieten die CPC-Fassadenkollektoren neben dem Einsatz als Bruestungselemente auch innerhalb der verglasten Gebaeuden nicht nur ein architektonisches Gestaltungselement, sondern vereinen als multifunktionaler Bestandteil noch mehrere Funktionen.

Theiss, Eric

2013-10-15

172

Materials in solar thermal collectors - International cooperation within the framework of the Solar Heating and Cooling Programme of the International Energy Agency; Material i plana termiska solfaangare - Internationellt samarbete inom ramen foer IEAs solvaermeprogram under 1998  

Energy Technology Data Exchange (ETDEWEB)

Efforts made during 1998 by the Swedish National Testing and Research Institute within the framework of the international working group `Materials in Solar Thermal Collectors` of the Solar Heating and Cooling Programme of the International Energy Agency are briefly reviewed. Research work deals with a) durability and life-time assessment of solar absorber coatings, b) methods for characterization of micro climate for materials in flat plate solar collectors, and c) antireflecting coatings and transparent polymeric materials for solar thermal applications. Results of the work include a) recommended methods for assessment of durability of solar absorber surfaces, b) methods for characterization of climate inside of solar collectors for the purpose of durability testing, and c) methods for testing the mechanical properties and weatherability of antireflecting coatings and transparent polymeric cover plate materials 15 figs, 5 tabs

Carlsson, Bo; Moeller, Kenneth; Andersson, B.L.; Andersson, Ingemar

1998-12-31

173

Biological sample collector  

Science.gov (United States)

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.

Murphy, Gloria A. (French Camp, CA)

2010-09-07

174

Effects of different collector’s area on the coupling of a thermosiphon collector and a single zone  

International Nuclear Information System (INIS)

Graphical abstract: - Highlights: • We simulate a thermosiphon collector associated to a single zone using TRNSYS. • We examine the temperature of water in collector, in tank and in single zone. • We study the temporal evolution of the temperature and the energy for 11 h operation in January and 2880 h operation in winter. • The system gives good results in all operating states. • The use of solar energy in the residential building is interesting. - Abstract: The novelty of this paper is the coupling between a thermosiphon collector and a single zone with the following details; a thermosiphon system (TYPE 45) which uses the solar energy as an unlimited renewable energy to produce the heat by using an internal coupling of a flat plate collector and a storage tank in a closed loop realized in TRNSYS. Consequently, the user simply utilizes TYPE 45 as thermosiphon ready to be run, and a single zone (TYPE 19) is a complex type which is designed for residential buildings that can be specified by the user in order to obtain an acceptable heating within a house. The user specified the characteristics of the internal space, external weather conditions, walls, windows, and doors. To facilitate this description, the parameters and inputs for this component are organized in separate table according to a logical structure. According to us, the choice of this model of thermosiphon coupled with a single zone can have multiple interesting engineering applications, in particular ameliorating the mode of the heating in residential buildings. Two flat plate collectors of aperture area of 6 and 8 m2 are modeled. The solar fraction of the entire system is used as the optimization parameter. The temperature of the water in the storage tank, the collector’s temperature, the temperature inside and outside the house, the solar fraction for different collector areas and the total energy were also measured in 11 h operation in January and 2880 h operation in winter. The average solar fraction obtained was 85% and the system could cover all the hot water needs of a house of six people. The maximum auxiliary energy was needed during 11 h operation in January and 4 months in winter. The results show that by utilizing solar energy, the designed system could provide 40–70% of the hot water demands in winter

175

Angular Distribution Models for Top-of-Atmosphere Radiative Flux Estimation from the Clouds and the Earth's Radiant Energy System Instrument on the Tropical Rainfall Measuring Mission Satellite. Part 1; Methodology  

Science.gov (United States)

Clouds and the Earth s Radiant Energy System (CERES) investigates the critical role that clouds and aerosols play in modulating the radiative energy flow within the Earth-atmosphere system. CERES builds upon the foundation laid by previous missions, such as the Earth Radiation Budget Experiment, to provide highly accurate top-of-atmosphere (TOA) radiative fluxes together with coincident cloud and aerosol properties inferred from high-resolution imager measurements. This paper describes the method used to construct empirical angular distribution models (ADMs) for estimating shortwave, longwave, and window TOA radiative fluxes from CERES radiance measurements on board the Tropical Rainfall Measuring Mission satellite. To construct the ADMs, multiangle CERES measurements are combined with coincident high-resolution Visible Infrared Scanner measurements and meteorological parameters from the European Centre for Medium-Range Weather Forecasts data assimilation product. The ADMs are stratified by scene types defined by parameters that have a strong influence on the angular dependence of Earth's radiation field at the TOA. Examples of how the new CERES ADMs depend upon the imager-based parameters are provided together with comparisons with existing models.

Loeb, N. G.; Smith, N. M.; Kato, S.; Miller, W. F.; Gupta, S. K.; Minnis, P.; Wielicki, B. A.

2003-01-01

176

Liquid solar collector  

Science.gov (United States)

Report documents evaluation test on commercial flat-plate solar collector that uses water as working fluid. Performance was measured before and after 34-day exposure to natural environment. Tables in metric and English units present data on air and water temperatures, waterflow, insolation, efficiency, and windspeed and direction.

1980-01-01

177

Structurally integrated steel solar collector  

Energy Technology Data Exchange (ETDEWEB)

Herein is disclosed a flate plate solar heat collector unit. The solar collector is integrated as a structural unit so that the collector also functions as the building roof. The functions of efficient heat collection, liquid coolant flow passages, roof structural support, and building insulation are combined into one unit.

Moore, S.W.

1975-06-03

178

Optimum solar collector fluid flow rates  

DEFF Research Database (Denmark)

Experiments showed that by means of a standard electronically controlled pump, type UPE 2000 from Grundfos it is possible to control the flow rate in a solar collector loop in such a way that the flow rate is strongly influenced by the temperature of the solar collector fluid passing the pump. The flow rate is increasing for increasing temperature.The flow rate at the high temperature level is typically 70 % greater than the flow rate at the low temperature level.Further, the energy consumption for the electronically controlled pump in a solar heating system will be somewhat smaller than the energy consumption of a normal ciculation pump in the solar heating system.Calculations showed that the highest thermal performances for small SDHW systems based on mantle tanks with constant volume flow rates in the solar collector loops are achieved if the flow rate is situated in the interval from 0.2 to 0.3 l/min. per m^2 solar collector for combi tank systems and in the interval from 0.3 to 0.4 l/min. per m^2 solar collector for preheating systems. Further, calculations showed that by means of an advanced control strategy for the flow rate - for instance if the flow rate is directly proportional to the temperature difference between the solar collector and the bottom of the mantle - an increase of about 1% of the thermal performance is possible.Finally, calculations showed that the highest thermal performance for large SDHW systems with constant volume flow rates in the solar collector loops are achieved if the flow rates in the solar collector loops are between 0.15 and 0.2 l/min. per m^2 solar collector. Also for large systems an increase of about 1% is possible by means of an advanced control strategy for the flow rate.Most likely, better control strategies than the investigated control strategies can be found. However, it is unlikely that significant thermal increases can be achieved by means of advanced control strategies.

Furbo, Simon; Shah, Louise Jivan

1996-01-01

179

Heat Pumps With Direct Expansion Solar Collectors  

Science.gov (United States)

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.

Ito, Sadasuke

180

Correlation analysis of infrared radiant intensity between hyperplastic breast tissue and tongue surface in patients with hyperplasia of mammary glands  

Directory of Open Access Journals (Sweden)

Full Text Available Objective: To establish a supplementary diagnostic indicator (infrared radiant intensity in tongue diagnosis of traditional Chinese medicine (TCM in patients with hyperplasia of mammary glands through correlation analysis of infrared radiant intensity between hyperplastic breast tissue and tongue surface.Methods: Infrared radiant intensity of the hyperplastic breast tissue and different points on tongue surface in 20 cases of hyperplasia of mammary glands with liver-energy stagnation and phlegm retention syndrome and 16 cases of hyperplasia of mammary glands with irregular thoroughfare and conception vessels syndrome were measured with external infrared spectrometer PHE-201 made by Shanghai Institute of Technical Physics. Correlation of infrared radiant intensity between the hyperplastic breast tissue and the different points on tongue surface was assessed by using bivariate correlation analysis.Results: The results showed that the numbers of positive correlated wave bands of infrared radiant intensity between the hyperplastic breast tissue and different detected points on tongue surface in the patients with liver-energy stagnation and phlegm retention syndrome and irregular thoroughfare and conception vessels syndrome were 127 (83.55% and 71 (46.71%, respectively. Infrared radiant intensity between the hyperplastic breast tissue and the tongue surface had a positive correlation.Conclusion: Infrared radiant intensity can be used as one of supplementary diagnostic indicators in TCM tongue diagnosis of hyperplasia of mammary glands.

Zhi-feng ZHANG

2007-11-01

 
 
 
 
181

Domestic Heat Pump System With Solar Thermal Collectors as Heat Source and Annual Ice Storage  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Aim of this paper is a theoretical and experimental investigation of a domestic heating system with heat pump using solar thermal collectors as the only heat source. In the system described, the heat pump uses an ice-water tank as annual storage system taking advantage of the phase change at 0°C. Energy is supplied to the storage system using low temperature solar thermal collectors. Low temperatures inside the solar collector lead to an increased annual yield. The thermal collectors can als...

Gschwend, Andreas; Bertsch, Stefan S.

2012-01-01

182

Optical, Energetic and Exergetic Analyses of Parabolic Trough Collectors  

Science.gov (United States)

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.

Murat, Öztürk; Nalan Çiçek, Bezir; Nuri, Özek

2007-07-01

183

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 ? mm mrad to 25 ? 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.)

184

The weighted words collector  

CERN Document Server

Motivated by applications in bioinformatics, we consider the word collector problem, i.e. the expected number of calls to a random weighted generator of words of length $n$ before the full collection is obtained. The originality of this instance of the non-uniform coupon collector lies in the, potentially large, multiplicity of the words/coupons of a given probability/composition. We obtain a general theorem that gives an asymptotic equivalent for the expected waiting time of a general version of the Coupon Collector. This theorem is especially well-suited for classes of coupons featuring high multiplicities. Its application to a given language essentially necessitates some knowledge on the number of words of a given composition/probability. We illustrate the application of our theorem, in a step-by-step fashion, on three exemplary languages, revealing asymptotic regimes in $\\Theta(\\mu(n)\\cdot n)$ and $\\Theta(\\mu(n)\\cdot \\log n)$, where $\\mu(n)$ is the sum of weights over words of length $n$.

Boisberranger, Jérémie Du; Ponty, Yann

2012-01-01

185

Prelaunch Calibrations of the Clouds and the Earth's Radiant Energy System (CERES) Tropical Rainfall Measuring Mission and Earth Observing System Morning (EOS-AM1) Spacecraft Thermistor Bolometer Sensors  

Science.gov (United States)

The Clouds and the Earth's Radiant Energy System (CERES) spacecraft scanning thermistor bolometer sensors measure earth radiances in the broadband shortwave solar (O.3 - 5.0 micron and total (0.3 to 100 microns) spectral bands as well as in the 8-12 microns water vapor window spectral band. On November 27, 1997, the launch of the Tropical Rainfall Measuring Mission (TRMM) spacecraft placed the first set of CERES sensors into orbit, and 30 days later, the sensors initiated operational measurements of the earth radiance fields. In 1998, the Earth Observing System morning (EOS-AM1) spacecraft will place the second and third sensor sets into orbit. The prelaunch CERES sensors' count conversion coefficients (gains and zero-radiance offsets) were determined in vacuum ground facilities. The gains were tied radiometrically to the International Temperature Scale of 1990 (ITS-90). The gain determinations included the spectral properties (reflectance, transmittance, emittance, etc.) of both the sources and sensors as well as the in-field-of-view (FOV) and out-of-FOV sensor responses. The resulting prelaunch coefficients for the TRMM and EOS-AM1 sensors are presented. Inflight calibration systems and on-orbit calibration approaches are described, which are being used to determine the temporal stabilities of the sensors' gains and offsets from prelaunch calibrations through on-orbit measurements. Analyses of the TRMM prelaunch and on-orbit calibration results indicate that the sensors have retained their ties to ITS-90 at accuracy levels better than /- 0.3% between the 1995 prelaunch and 1997 on-orbit calibrations.

Lee, Robert B., III; Barkstrom, Bruce R.; Bitting, Herbert C.; Crommelynck, Dominique A. H.; Paden, Jack; Pandey, Dhirendra K.; Priestley, Kory J.; Smith, G. Louis; Thomas, Susan; Thornhill, K. Lee; Wilson, Robert S.

1998-01-01

186

Evacuated tubular or classical flat plate solar collectors?  

Directory of Open Access Journals (Sweden)

Full Text Available Evacuated tubular solar collectors are increasingly used all over the world due to their low coefficients of heat losses to the environment. They are presented as a device collecting much larger quantities of solar energy than is usually possible to obtain from typical flat collector. They have, however, unfavorable radiation transmissivity characteristics of transparent shield of absorber. It causes that the profits of energy gain at the operating conditions of typical solar system in our country only slightly dependent on the nature of the solar collectors applied. This article is an attempt to explain this phenomenon through theoretical considerations.

Zbyslaw Pluta

2011-01-01

187

Optimal tilt-angles of all-glass evacuated tube solar collectors  

International Nuclear Information System (INIS)

In this paper, a detailed mathematical procedure is developed to estimate daily collectible radiation on single tube of all-glass evacuated tube solar collectors based on solar geometry, knowledge of two-dimensional radiation transfer. Results shows that the annual collectible radiation on a tube is affected by many factors such as collector type, central distance between tubes, size of solar tubes, tilt and azimuth angles, use of diffuse flat reflector (DFR, in short); For collectors with identical parameters, T-type collectors (collectors with solar tubes tilt-arranged) annually collect slightly more radiation than H-type collectors (those with solar tubes horizontally arranged) do. The use of DFR can significantly improve the energy collection of collectors. Unlike the flat-plate collectors, all-glass evacuated tube solar collectors should be generally mounted with a tilt-angle less than the site latitude in order to maximize the annual energy collection. For most areas with the site latitude larger than 30o in China, T-type collectors should be installed with a tilt-angle about 10o less than the site latitude, whereas for H-type collectors without DFR, the reasonable tilt-angle should be about 20o less than the site latitude. Effects of some parameters on the annual collectible radiation on the collectors are also presented.

188

“ANALYSIS ON PERFORMANCE OF RADIANT HEAT EXCHANGER OF THERMIC FLUID HEATER BY CHANGING THE SUITABLE GRADE OF MATERIAL”  

Digital Repository Infrastructure Vision for European Research (DRIVER)

To make the radiant heat exchanger of higher performance and efficiency at low manufacturing and maintenance cost in which maximum utilization of heat energy of flue gases is possible and also which is less expensive and easily accommodate by any process industries for their usual operation. Also to improve working condition and decrease the operating cost by changing the grade of material of tubes for required mechanical and thermal property for which the radiant heat exchanger is to be desi...

Patel Ronak I.; Tandel Shyamal N.; Patel Miteshkumar H.; Patel Jaykumar S.; MominInayat Husain M.

2014-01-01

189

“ANALYSIS ON PERFORMANCE OF RADIANT HEAT EXCHANGER OF THERMIC FLUID HEATER BY CHANGING THE SUITABLE GRADE OF MATERIAL”  

Directory of Open Access Journals (Sweden)

Full Text Available To make the radiant heat exchanger of higher performance and efficiency at low manufacturing and maintenance cost in which maximum utilization of heat energy of flue gases is possible and also which is less expensive and easily accommodate by any process industries for their usual operation. Also to improve working condition and decrease the operating cost by changing the grade of material of tubes for required mechanical and thermal property for which the radiant heat exchanger is to be designed.

Patel Ronak I.

2014-09-01

190

Design and optimization of an inovating thermal solar collector adapted to the energy restoration thanks to the storage integration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The primary energy consumption of domestic hot water (DHW) in low energy house becomes proportionately large when compared to other energy consumptions. In new buildings, the integration of DHW systems do not present any di?culty. However, the thermal renovation market is poorly operated, with the storage's placement as the main constraint. When the storage must be placed outside the building, nowadays the solutions are not satisfactory, or by a thermal point of view (high losses), or an ae...

Vidigal Duarte Souza, Jeronimo

2012-01-01

191

Solar heat collector  

Energy Technology Data Exchange (ETDEWEB)

A solar heat collector unit comprising: a heat conductive back plate, a plurality of heat conductive partitions protruding away from one face of said back plate, said partitions being of cup-shaped configuration with the longitudinal axes of the cups extending perpendicularly to the back plate, and a transparent sheet sealed in spaced relationship from said back plate through which solar heat can pass to be absorbed by the plate and partitions, said transparent sheet and back plate defining a passage therebetween through which fluid may pass and absorb heat from the back plate and partitions.

Keyes, J.H.; Strickland, C.I.; Strickland, R.G.

1974-10-16

192

A solar collector design procedure for crop drying  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A design procedure was proposed for sizing solar-assisted crop-drying systems and assessing the combination of solar collector area and auxiliary energy needs that meets the requirements of the load. Two empirical correlations were compared for use with high thermal inertia solar collectors that are cheap and appropriate for rural areas. A case study as performed in the city of Campinas in southeastern Brazil. Grain drying with partial air heating by solar energy can provide an annual savings...

Santos, B. M.; Queiroz, M. R.; Borges, T. P. F.

2005-01-01

193

Subjective evaluation of different ventilation concepts combined with radiant heating and cooling  

DEFF Research Database (Denmark)

Sixteen subjects evaluated the indoor environment in four experiments with different combinations of ventilation and radiant heating/cooling systems. Two test setups simulated a room in a low energy building with a single occupant during winter. The room was equipped either by a ventilation system supplying warm air space heating or by a combination of radiant floor heating and mixing ventilation system. Next two test setups simulated an office room with two occupants during summer, ventilated and cooled by a single displacement ventilation system or by a radiant floor cooling combined with displacement ventilation. Vertical air temperature distribution was more uniform for floor heating than for warm air heating, but there was no significant difference in thermal perception between the two mixing ventilation systems. For the summer conditions the subjects voted warmer than predicted by the PMV and about one third preferred more air movement. No significant difference in thermal perception between the two displacement ventilation systems was found.

Krajcik, Michal; Tomasi, Roberta

2012-01-01

194

ADVANCED HYBRID PARTICULATE COLLECTOR  

Energy Technology Data Exchange (ETDEWEB)

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

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

2001-12-01

195

A high performance porous flat-plate solar collector  

Science.gov (United States)

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

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

1979-01-01

196

The effects of unbalanced flow on the thermal performance of collector arrays  

Science.gov (United States)

This paper details a mathematical model and a computer program that were developed to examine the effects of a flow imbalance on the total solar energy gain of a collector array. The model allows for variation in collector geometry, array geometry, collector flow rate, and collector inlet temperature, as well as fluctuations in ambient temperature and incident solar radiation. The program calculates the collector plate temperature, the heat removal factor, the collector heat loss coefficient, and the solar energy collected. The program is written in the BASIC language. It is iterative and uses the collector plate temperature as its test for convergence. The significance of a flow imbalance is explored by a systematic variation of the above parameters. Results indicate a relatively minor penalty for an unbalanced system, provided none of the rows in the array stagnate.

Culham, R.; Sauer, P.

1984-05-01

197

State-of-the-art review of low-cost collector technologies  

Science.gov (United States)

This report provides a brief but concise review of low-cost solar collector technologies and their potential for application within the military. The report covers low-cost, light-weight concepts for flat-plate collectors, parabolic trough collectors, heliostats and parabolic dish collectors. In addition, several criteria were evaluated with respect to low-cost collector technologies. These included reliability, maintainability, survivability, mobility/erectibility, environmental impact and economics. Research and development requirements and ongoing activities were also summarized. This report documents one of several ongoing state-of-the-art reviews of solar technologies performed by an Air Force liaison office with the Department of Energy.

Tolbert, W. A.

1981-06-01

198

Overheating protection for solar thermal collectors; Ueberhitzungsschutzmassnahmen fuer solarthermische Kollektoren  

Energy Technology Data Exchange (ETDEWEB)

The manufacturers of solar thermal systems continuously are endeavoured to reduce the production costs of solar collector. In this regard, the research project, 'Plastics in solar collectors: requirements definition, concept development and feasibility assessment' is performed at the competence field of renewable energies of the Ingolstadt University (Ingolstadt, Federal Republic of Germany). This research project pursues the target to capture measures of overheating protection for solar thermal collectors and to systematize these measures regarding to their mechanism of action. Subsequently, these measures will be classified regarding their own safety. The potential of utilization of these measures is evaluated.

Reiter, Christoph; Trinkl, Christoph; Zoerner, Wilfried [Hochschule Ingolstadt (Germany). Kompetenzfeld Erneuerbare Energien; Hanby, Vic [De Montfort Univ. Leicester (United Kingdom). Inst. of Energy and Sustainable Development

2010-07-01

199

Improved radiant burner material. Final report  

Energy Technology Data Exchange (ETDEWEB)

Under DOE/ERIP funds were made available to Superkinetic, Inc. for the development of an improved radiant burner material. Three single crystal ceramic fibers were produced and two fiber materials were made into felt for testing as radiant burner screens. The materials were alpha alumina and alpha silicon nitride. These fibers were bonded with a high temperature ceramic and made into a structurally sound trusswork like screen composed of million psi fiber members. These screens were about 5% solid for 95 porosity as needed to permit the flow of combustable natural gas and air mixture. Combustion test proved that they performed very satisfactory and better than the current state of art screen and showed no visable degrade after testing. It is recommended that more time and money be put into expanding this technology and test these new materials for their maximum temperature and durability for production applications that require better burner material.

Milewski, J.V.; Shoultz, R.A.; Bourque, M.M.; Milewski, E.B. [and others

1998-01-01

200

Skin diseases in tea collectors  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The tea collection is a difficult and laborious task, but few studies have analyzed risks by work activities or the work environment. To investigate the effects of work activities and work environment on tea collectors by looking from dermatological perspective, detailed dermatological examination was performed on tea collectors and clinical backgrounds of the participants were question...

Nursel Dilek; Aziz Ramazan Dilek; Yunus Saral; Ahmet Metin

2014-01-01

 
 
 
 
201

Absolute radiant power measurement of the X-ray free-electron laser at SACLA  

International Nuclear Information System (INIS)

The Japanese hard X-ray free-electron laser (XFEL), SACLA (SPring-8 Angstrom Compact free-electron LAser), reached laser amplification at 10 keV photon energy in June 2011. SACLA can provide XFELs with its wavelength of shorter than 0.1 nm. Since the radiant power is a fundamental parameter of the XFEL beam which strongly influences nonlinear effects, its measurement in absolute terms is of significant importance. In the present study, the absolute radiant power of the XFEL was measured using a cryogenic radiometer at the BL3 in SACLA. The radiant power as a function of a silicon attenuator thickness was also measured to estimate the contribution of the higher harmonics. The radiant power in the range between 8 ?W and 1005 ?W was measured in the photon energies of 4.4 keV, 5.8 keV, 9.6 keV, 13.6 keV and 16.8 keV. The contribution of the higher harmonics is negligible except for the photon energy of 4.4 keV. The third harmonics component in the photon energy of 4.4 keV is about 1 %.

202

Pyrocore - radiant burner with a bright future  

Energy Technology Data Exchange (ETDEWEB)

A new type of radiant burner developed by Alzeta Corporation offers improved performance to gas equipment for all market sectors. Soon to be introduced to the industrial market in York-Shipley, Inc.'s line of industrial firetube boilers, the Pyrocore burner has a high heat flux, uniform heat distribution, high efficiency, and low emissions. The practical value of these features will vary with the application.

Schaedel, S.V.

203

Partially -premixed combustion in porous radiant burners  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Inert porous radiant burners are commonly employed in materials processing and manufacturing (drying, cooking, etc.). In spite of this extensive use, little knowledge was available concerning the operating characteristics and flame structure of such burners until recently. The advent of a new generation of natural gas-fired burners that include an active matrix introduces further challenges and opens new areas of research. The first catalytic heaters were diffusion-type; recent attempts to im...

Leonardi, Sergio Adrian

2000-01-01

204

Measurement of radiant properties of ceramic foam  

International Nuclear Information System (INIS)

An experimental facility is described for the measurement of the normal spectral and total emissivity and transmissivity of semi-transparent materials in the temperature range of 600 C to 1200 C. The set-up was used for the measurement of radiation properties of highly porous ceramic foam which is used in low NOx radiant burners. Emissivity and transmissivity data were measured and are presented for coated and uncoated ceramic foam of different thicknesses. (orig.)

205

Optimization of operational and design parameters of plane reflector-tilted flat plate solar collector systems  

Energy Technology Data Exchange (ETDEWEB)

Due to the increased interest in the utilization of solar energy, it is essential to enhance the energy collection of solar energy devices. In this paper, a theoretical analysis of the instantaneous, daily, and yearly enhancement in solar energy collection of a tilted flat-plate solar collector augmented by a plane reflector is developed. The shadow effect due to the reflector on the collector is considered in the analysis. A FORTRAN computer program has been constructed based on the analysis in order to study the effect of different operational and design parameters of plane reflector-tilted flat-plate solar collector system on the collector solar energy collection. These parameters include collector-reflector system orientation and tilt angles, collector elongation ratio, and reflector overhang ratio. (author)

Hussein, H.M.S.; Ahmad, G.E.; Mohamad, M.A. [National Research Centre, Giza (Egypt). Solar Energy Dept.

2000-06-01

206

Colored solar collectors - Annual report 2006  

Energy Technology Data Exchange (ETDEWEB)

The architectural integration of thermal solar collectors into buildings is often limited by their black color, and the visibility of tubes and corrugations of the absorber sheets. A certain freedom in color choice would be desirable, but the colored appearance should not cause an excessive degradation of the collector efficiency. Multilayered thin film interference filters on the collector glazing can produce a colored reflection, hiding the corrugated metal sheet, while transmitting the non-reflected radiation entirely to the absorber. These interference filters are designed and optimized by numerical simulation, and are manufactured by sol-gel dip-coating or magnetron sputtering. The novel colored glazed solar collectors will be ideally suited for architectural integration into buildings, e.g. as solar active glass facades. Due to the tunability of the refractive index, nanostructured materials such as SiO{sub 2}:TiO{sub 2} composites and porous SiO{sub 2} are very useful for application in multilayer interference stacks. Novel quaternary Mg-F-Si-O films exhibit a surprisingly low refractive index and are therefore promising candidates for highly transparent coatings on solar collector glazing. The nanostructure of these thin films is studied by transmission electron microscopy, while the optical constants are measured precisely by ellipsometry. For a convincing demonstration, sufficiently large samples of high quality are imperatively needed. The fabrication of nanocomposite SiO{sub 2}:TiO{sub 2} films has been demonstrated by sol-gel dip-coating of A4-sized glass panes. The produced coatings exhibit a colored reflection in combination with a high solar transmittance, a homogenous appearance, and are free of visible defects. Film hardening by UV exposure will result in speeding up the sol-gel process and saving energy, thereby reducing costs significantly. The infrastructure for UV-curing has been established. A UV C radiation source can now be attached to the dip-coater, which is placed in a UV-screened laminar flow chapel. An industrial partner for the prototype fabrication of colored collector glazing has been found. For a first attempt of industrial scale production, adapted multilayer designs have been proposed. First tests on the industrial magnetron sputtering equipment have shown encouraging results, but some adaptations are still needed. Possible ways of implementation of the novel colored solar collectors/solar facades are investigated and discussed with facade manufacturers and architects. (authors)

Schueler, A.; Chambrier, E. De; Roecker, Ch.; Scartezzini, J.-L.

2007-12-15

207

Radiant ephemeris of the Taurid meteor complex  

Science.gov (United States)

The radiant ephemeris of the Taurid complex meteor showers derived from IMO video observations from 1995-2004 is presented. Detailed radiant ephemerides of the Northern (NPI) and Southern Piscids (SPI) and the Northern (NTA) and Southern Taurids (STA) are derived. Tentative radiant motions of the Northern and Southern chi-Orionids (ORN and ORS) are presented. The Taurids (NTA and STA) are active from the beginning of September to the end of November; the Southern Taurids disappear earlier around November 20. While the Northern Taurids appear to be slower until about October 20 than in the second part of their activity period, the Southern Taurids do not exhibit sub-components. The Southern Piscids (SPI) are active only in September and their activity is much lower than the activity of the Taurids at that time. The Northern Piscids are a little more prominent than the Southern Piscids and are detectable from the beginning of September to October 18, with a probable maximum period from September 20 to October 2.

Triglav-?ekada, M.; Arlt, R.

2005-04-01

208

Quality control on radiant heaters manufacture  

Science.gov (United States)

An inspection process of radiant heaters is presented in this paper. The proposed non destructive testing and evaluation (NDT and E) technique for defect assessment of radiant heaters is based on infrared thermography images properly acquired and processed. The technique can be used in on-line fabrication quality control radiant heaters manufacturing processes. By exciting the heater with a very short electrical pulse, a sequence of thermographic images is captured by an infrared camera and then analyzed. Regardless of the electrical excitation applied to the heating element of the heater, the electrical power supplied will dissipate at the resistor. Provided enough spatial resolution, the heaters could be tested with an infrared camera capturing the radiated heat. The analysis of the heating wire during the heating flank shows differences among pixels corresponding to defective points and pixels belonging to non-defective areas of the wire. The automation is provided by the development of an algorithm that looks for the slope of the heating evolution of each pixel. A Radon Transform based algorithm is here proposed to reduce human intervention providing just one image where an operator could quickly locate possible defects.

González, Daniel A.; Madruga, Francisco J.; Ibarra-Castanedo, Clemente; Conde, Olga; López-Higuera, Jose M.

2006-04-01

209

Radiant heat and thermal comfort in vehicles.  

Science.gov (United States)

Infrared-reflective (IRR) treatment of automotive glass has been shown to reduce air temperature in vehicle cabins, thereby increasing fuel economy and occupant comfort. Its effect on radiant heat, however, may augment these benefits. In this study, the hypothesis that radiant heat affects subjective comfort ratings in a vehicle was tested. IRR films were systematically applied to the driver-side window of an outdoor stationary vehicle. In Phase 1, cabin air temperature was controlled while participants rated their thermal comfort. In Phase 2, air temperature was adjusted according to participants' responses. Results in Phase 1 showed that the IRR treatment improved thermal comfort on the left forearm, which was exposed to direct solar irradiance, but not whole-body thermal comfort. In Phase 2, participants indicated that they were comfortable at a higher air temperature (mean of 2.5 degrees F [1.4 degrees C]) with the IRR treatment than in the untreated condition. The results indicate that reducing radiant heat via IRR treatment affects subjective assessments of thermal comfort and allows occupants to maintain the same level of comfort in a warmer vehicle cabin. Applications of this research include future implementations of IRR treatment on automotive glass that may lead to greater fuel economy savings and occupant comfort than have previously been estimated. PMID:16553069

Devonshire, Joel M; Sayer, James R

2005-01-01

210

A Self-Biasing Pulsed Depressed Collector  

International Nuclear Information System (INIS)

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)

211

A Self-Biasing Pulsed Depressed Collector  

Energy Technology Data Exchange (ETDEWEB)

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)

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

2014-05-29

212

A detailed thermal model of a parabolic trough collector receiver  

International Nuclear Information System (INIS)

Parabolic trough collectors are made by bending a sheet of reflective material into a parabolic shape. A metal black pipe, covered with a glass tube to reduce heat losses, is placed along the focal line of the collector. The concentrated radiation reaching the receiver tube heats the fluid that circulates through it, thus transforming the solar radiation into useful heat. It is sufficient to use a single axis tracking of the sun and thus long collector modules are produced. In this paper a detailed thermal model of a parabolic trough collector is presented. The thermal analysis of the collector receiver takes into consideration all modes of heat transfer; convection into the receiver pipe, in the annulus between the receiver and the glass cover, and from the glass cover to ambient air; conduction through the metal receiver pipe and glass cover walls; and radiation from the metal receiver pipe and glass cover surfaces to the glass cover and the sky respectively. The model is written in the Engineering Equation Solver (EES) and is validated with known performance of existing collectors and subsequently is used to perform an analysis of the collector we are going to install at Archimedes Solar Energy Laboratory at the Cyprus University of Technology.

213

Angular Distribution Models for Top-of-Atmosphere Radiative Flux Estimation from the Clouds and the Earth's Radiant Energy System Instrument on the Tropical Rainfall Measuring Mission Satellite. Part II; Validation  

Science.gov (United States)

Top-of-atmosphere (TOA) radiative fluxes from the Clouds and the Earth s Radiant Energy System (CERES) are estimated from empirical angular distribution models (ADMs) that convert instantaneous radiance measurements to TOA fluxes. This paper evaluates the accuracy of CERES TOA fluxes obtained from a new set of ADMs developed for the CERES instrument onboard the Tropical Rainfall Measuring Mission (TRMM). The uncertainty in regional monthly mean reflected shortwave (SW) and emitted longwave (LW) TOA fluxes is less than 0.5 W/sq m, based on comparisons with TOA fluxes evaluated by direct integration of the measured radiances. When stratified by viewing geometry, TOA fluxes from different angles are consistent to within 2% in the SW and 0.7% (or 2 W/sq m) in the LW. In contrast, TOA fluxes based on ADMs from the Earth Radiation Budget Experiment (ERBE) applied to the same CERES radiance measurements show a 10% relative increase with viewing zenith angle in the SW and a 3.5% (9 W/sq m) decrease with viewing zenith angle in the LW. Based on multiangle CERES radiance measurements, 18 regional instantaneous TOA flux errors from the new CERES ADMs are estimated to be 10 W/sq m in the SW and, 3.5 W/sq m in the LW. The errors show little or no dependence on cloud phase, cloud optical depth, and cloud infrared emissivity. An analysis of cloud radiative forcing (CRF) sensitivity to differences between ERBE and CERES TRMM ADMs, scene identification, and directional models of albedo as a function of solar zenith angle shows that ADM and clear-sky scene identification differences can lead to an 8 W/sq m root-mean-square (rms) difference in 18 daily mean SW CRF and a 4 W/sq m rms difference in LW CRF. In contrast, monthly mean SW and LW CRF differences reach 3 W/sq m. CRF is found to be relatively insensitive to differences between the ERBE and CERES TRMM directional models.

Loeb, N. G.; Loukachine, K.; Wielicki, B. A.; Young, D. F.

2003-01-01

214

LHCb Tag Collector  

Science.gov (United States)

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

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

2011-12-01

215

Biobriefcase aerosol collector  

Science.gov (United States)

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.

Bell, Perry M. (Tracy, CA); Christian, Allen T. (Madison, WI); Bailey, Christopher G. (Pleasanton, CA); Willis, Ladona (Manteca, CA); Masquelier, Donald A. (Tracy, CA); Nasarabadi, Shanavaz L. (Livermore, CA)

2009-09-22

216

HOME ENERGY SUPPLY-DEMAND ANALYSIS FOR COMBINED SYSTEM OF SOLAR HEAT COLLECTOR AND HEAT PUMP WATER HEATER  

Science.gov (United States)

In order to evaluate effectiveness of a combined system of solar heat collecctor (SHC) and heat pump water heater (HPWH), optimum operation scheduling moldel of domestic electric appliances using the mixed integer linear programming was enhanced. Applying this model with one house data in Tokyo, it was found that the combined system of the SHC and the HPWH has the enough energy-saving and CO2 emission reduction potential under the existing electricity late and the operation method of the HPWH. Furthermore, the calculation results under the future system show that the combined system of the SHC and the HPWH has also the reduction effect of reverse power flow from residential photovoltaic system.

Ikegami, Takashi; Kataoka, Kazuto; Iwafune, Yumiko; Ogimoto, Kazuhiko

217

Thermal Evaluation of a Solarus PV-T collector  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

Haddi, Jihad

2013-01-01

218

Design Support System for Parabolic Trough Solar Collector  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Parabolic Trough Collector (PTC) is special kind of heat exchanger that is able to transfer solar radiation energy to fluid medium that flow through it. Designing a PTC for a specific working condition requires determination of several parameters and referring to a number of design standards and handbooks. Hence, a design support system is required to determine the necessary parameters and simulate different working conditions. Although, a number of design support systems for solar collectors...

Woldeyohannes, Abraham D.; Cheng, Hoe K.; Woldemichael, Dereje E.; Lim Chye Ing

2012-01-01

219

TELBE - the super-radiant THz facility at ELBE  

International Nuclear Information System (INIS)

It has been shown recently that relativistic electron bunches can be utilized for the generation of super-radiant coherent THz radiation by one single pass through an undulator, bending magnet, or CDR/CTR screens. However, the high THz fields have all been achieved at large accelerators that allow for high electron beam energies. A crucially important research topic for the next years at the HZDR is therefore to investigate whether an equally fine control over highly charged electron bunch form can be routinely achieved in a low electron beam energy accelerator like ELBE. If successful this development would allow the generation of high field THz fields by linear accelerators at considerably reduced cost. Given stable operation can be provided, TELBE, could also become a world-wide unique research facility for high field THz science. The current status and an outlook on future developments are presented.

220

TELBE - the super-radiant THz facility at ELBE  

Energy Technology Data Exchange (ETDEWEB)

It has been shown recently that relativistic electron bunches can be utilized for the generation of super-radiant coherent THz radiation by one single pass through an undulator, bending magnet, or CDR/CTR screens. However, the high THz fields have all been achieved at large accelerators that allow for high electron beam energies. A crucially important research topic for the next years at the HZDR is therefore to investigate whether an equally fine control over highly charged electron bunch form can be routinely achieved in a low electron beam energy accelerator like ELBE. If successful this development would allow the generation of high field THz fields by linear accelerators at considerably reduced cost. Given stable operation can be provided, TELBE, could also become a world-wide unique research facility for high field THz science. The current status and an outlook on future developments are presented.

Green, Bertram; Kovalev, Sergei; Hauser, Jens; Kuntzsch, Michael; Schneider, Harald; Winnerl, Stephan; Seidel, Wolfgang; Zvyagin, Sergei; Lehnert, Ulf; Helm, Manfred; Michel, Peter; Gensch, Michael [Helmholtz-Zentrum Dresden-Rossendorf (Germany); Al-Shemmary, Alaa; Radu, Ilie; Stojanovic, Nikola; Cavalleri, Andrea [Deutsches Elektronen-Synchrotron (Germany); Wall, Simon [FHI Berlin (Germany); Eng, Lukas M. [Technische Universitaet Dresden (Germany); Heberle, Joachim [FU Berlin (Germany)

2013-07-01

 
 
 
 
221

Thermal Efficiency of Double Pass Solar Collector with Longitudinal Fins Absorbers  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Problem statement: One of the most important components of a solar energy system is the solar collector. The performances of double-pass solar collector with longitudinal fins absorbers are analyzed. Approach: The study involves a theoretical study to investigate the effect of mass flow rate, number and height of fins on efficiency, which involves steady-state energy balance equations on the longitudinal fins absorber of solar collectors. The theoretical solu...

Ahmad Fudholi; Kamaruzzaman Sopian; Ruslan, Mohd H.; Othman, Mohd Y.; Muhammad Yahya

2011-01-01

222

AEROSOL PARTICLE COLLECTOR DESIGN STUDY  

Energy Technology Data Exchange (ETDEWEB)

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.

Lee, S; Richard Dimenna, R

2007-09-27

223

Performance evaluation of radiant baseboards (skirtings) for room heating – An analytical and experimental approach  

International Nuclear Information System (INIS)

The aim of this study was to investigate the thermal performance of the hydronic radiant baseboards currently used for space heating in built environments. The presently available equations for determination of heat outputs from these room heaters are valid for a certain height at a specific temperature range. This limitation needed to be addressed as radiant baseboards may be both energy and cost efficient option for space heating in the future. The main goal of this study was therefore to design an equation valid for all baseboard heights (100–200 mm) and excess temperatures (9–60 °C) usually used in built environments. The proposed equation was created by curve fitting using the standard method of least squares together with data from previous laboratory measurements. It was shown that the predictions by the proposed equation were in close agreement with reported experimental data. Besides, it was also revealed that the mean heat transfer coefficient of the investigated radiant baseboards was about 50% higher than the mean heat transfer coefficient of five conventional panel radiators of different types. The proposed equation can easily be used or programed in energy simulation codes. Hopefully this will help engineers to quantify more accurately the energy consumption for space heating in buildings served by radiant baseboards. -- Highlights: • Thermal performance of radiant baseboards (RBs) used for space heating was analyzed. • The proposed heat output equation can be used with confidence for RBs heaters. • The heat transfer ability of RBs was 50% higher than that of panel radiators. • The heat emission from RBs increased by roughly 2.1% per centimeter of height. • The RBs of maximum height should be used for water supply temperatures below 45 °C

224

Design package for concentrating solar collector panels  

Energy Technology Data Exchange (ETDEWEB)

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.

1978-08-01

225

New concepts for solar collectors in 2030  

Energy Technology Data Exchange (ETDEWEB)

In 2030, solar energy is expected to cover the full energy demand of newly built houses. In addition, increasing standards for quality of living require that newly built houses offer increased comfort, while still being affordable. Current collector technology will not be able to meet all these requirements; hence, new collector concepts are required. This paper develops new concepts for the capture, conversion, and storage of solar energy with a focus on future integration in newly built houses. Industrial design engineering was used in the concept development, including an analysis of the field as well as a series of workshops. Out of several concepts, two were selected and elaborated. The first concept (aimed at 2015) is based on a passive house, and is able to fully provide the domestic energy use of both the user and the building itself. The second concept (aimed at 2030) integrates energy production, energy storage, building insulation, and an indoor climate system in durable, modular construction elements; the total energy production of this concept exceeds the total domestic energy use. This paper illustrates the concept development process and its results.

Bakker, M.; Van Helden, W. [ECN Efficiency and Infrastructure, Petten (Netherlands); Nijs, J.; Reinders, A. [University of Twente, Faculty of CTW, Department of Design, Production and Management, Enschede (Netherlands)

2009-01-15

226

A RADIANT AIR-CONDITIONING SYSTEM USING SOLAR-DRIVEN  

Directory of Open Access Journals (Sweden)

Full Text Available Every air-conditioning system needs some fresh air to provide adequate ventilation air required to remove moisture, gases like ammonia and hydrogen sulphide, disease organisms, and heat from occupied spaces. However, natural ventilation is difficult to control because urban areas outside air is often polluted and cannot be supplied to inner spaces before being filtered. Besides the high electrical demand of refrigerant compression units used by most air-conditioning systems, and fans used to transport the cool air through the thermal distribution system draw a significant amount of electrical energy in comparison with electrical energy used by the building thermal conditioning systems. Part of this electricity heats the cooled air; thereby add to the internal thermal cooling peak load. In addition, refrigerant compression has both direct and indirect negative effects on the environment on both local and global scales. In seeking for innovative air-conditioning systems that maintain and improve indoor air quality under potentially more demanding performance criteria without increasing environmental impact, this paper presents radiant air-conditioning system which uses a solar-driven liquid desiccant evaporative cooler. The paper describes the proposed solar-driven liquid desiccant evaporative cooling system and the method used for investigating its performance in providing cold water for a radiant air-conditioning system in Khartoum (Central Sudan. The results of the investigation show that the system can operate in humid as well as dry climates and that employing such a system reduces air-conditioning peak electrical demands as compared to vapour compression systems.

S. A. ABDALLA

2006-12-01

227

Numerical Modelling of Non-similar Mixed Convection Heat and Species Transfer along an Inclined Solar Energy Collector Surface with Cross Diffusion Effects  

Digital Repository Infrastructure Vision for European Research (DRIVER)

An analysis is performed to study thermo-diffusion and diffusion-thermo effects on mixed convection heat and mass transfer boundary layer flow along an inclined (solar collector) plate. The resulting governing equations are transformed and then solved numerically using the local nonsimilarity method and Runge-Kutta shooting quadrature. A parametric study illustrating the influence of thermal buoyancy parameter (ζ), Prandtl number (Pr), Schmidt...

Osman Anwar Bég; Ahmed Bakier; Ramachandra Prasad; Swapan Kumar Ghosh

2011-01-01

228

Improved Collectors for High Power Gyrotrons  

Energy Technology Data Exchange (ETDEWEB)

High power gyrotrons are used for electron cyclotron heating, current drive and parasitic mode suppression in tokamaks for fusion energy research. These devices are crucial for successful operation of many research programs around the world, including the ITER program currently being constructed in France. Recent gyrotron failures resulted from cyclic fatigue of the copper material used to fabricated the collectors. The techniques used to collect the spent beam power is common in many gyrotrons produced around the world. There is serious concern that these tubes may also be at risk from cyclic fatigue. This program addresses the cause of the collector failure. The Phase I program successfully demonstrated feasibility of a mode of operation that eliminates the cyclic operation that caused the failure. It also demonstrated that new material can provide increased lifetime under cyclic operation that could increase the lifetime by more than on order of magnitude. The Phase II program will complete that research and develop a collector that eliminates the fatigue failures. Such a design would find application around the world.

R. Lawrence Ives, Amarjit Singh, Michael Read, Philipp Borchard, Jeff Neilson

2009-05-20

229

Improved Collectors for High Power Gyrotrons  

International Nuclear Information System (INIS)

High power gyrotrons are used for electron cyclotron heating, current drive and parasitic mode suppression in tokamaks for fusion energy research. These devices are crucial for successful operation of many research programs around the world, including the ITER program currently being constructed in France. Recent gyrotron failures resulted from cyclic fatigue of the copper material used to fabricated the collectors. The techniques used to collect the spent beam power is common in many gyrotrons produced around the world. There is serious concern that these tubes may also be at risk from cyclic fatigue. This program addresses the cause of the collector failure. The Phase I program successfully demonstrated feasibility of a mode of operation that eliminates the cyclic operation that caused the failure. It also demonstrated that new material can provide increased lifetime under cyclic operation that could increase the lifetime by more than on order of magnitude. The Phase II program will complete that research and develop a collector that eliminates the fatigue failures. Such a design would find application around the world.

230

The False Radiants - a Simulation of the Meteor Sky  

Science.gov (United States)

We have made a simple simulation of July meteor observations. This artificial database includes the sporadic meteors and also events from known meteor showers: the Perseids, the Aquarids complex, the alpha-Capricornids, the July Pegasids and the Sagittarids. We found out that meteors from known radiants could not produce a false radiant in Delphinus constellation.

Wi?niewski, M.; Puzio, A.

231

Shape Control of Solar Collectors Using Shape Memory Alloy Actuators  

Science.gov (United States)

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.

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

1996-01-01

232

Combined solar collector and storage systems  

International Nuclear Information System (INIS)

The article discusses reasons why fossil-fuelled water heating systems are included in new houses but solar systems are not. The technology and market potential for evacuated tube systems and integral collector storage systems (ICSS) are explained. The challenge for the designers of ICSSWH has been how to reduce heat loss without compromising solar energy collection. A new concept for enhanced energy storage is described in detail and input/output data are given for two versions of ICSSWH units. A table compares the costs of ICSSWH in houses compared with other (i.e. fossil fuel) water heating systems

233

Convective-radiative interaction in a parallel plate channel - Application to air-operated solar collectors  

Science.gov (United States)

An analysis is made for simultaneously developing laminar velocity and temperature fields in a parallel plate channel in which convective and radiative heat transfer interact. One wall of the channel is externally heated and the other is externally insulated; air is the heat transfer fluid. These conditions are similar to those in an air-operated flat-plate solar collector. The results show that the radiant interchange causes the task of convective heating of the fluid to be shared between the two walls, with as much as 40% of the convective transfer taking place at the externally adiabatic wall. This can give rise to a significant reduction of the temperature of the directly heated wall which, for a solar collector, tends to improve its efficiency. The Nusselt numbers in the presence of radiation are higher than those for pure forced convection.

Liu, C. H.; Sparrow, E. M.

1980-08-01

234

Theoretical analysis to investigate thermal performance of co-axial heat pipe solar collector  

Energy Technology Data Exchange (ETDEWEB)

The thermal performance of co-axial heat pipe solar collector which consist of a collector 15 co-axial heat pipes surrounded by a transparent envelope and which heat a fluid flowing through the condenser tubes have been predicted using heat transfer analytical methods. The analysis considers conductive and convective losses and energy transferred to a fluid flowing through the collector condenser tubes. The thermal performances of co-axial heat pipe solar collector is developed and are used to determine the collector efficiency, which is defined as the ratio of heat taken from the water flowing in the condenser tube and the solar radiation striking the collector absorber. The theoretical water outlet temperature and efficiency are compared with experimental results and it shows good agreement between them. The main advantage of this collector is that inclination of collector does not have influence on performance of co-axial heat pipe solar collector therefore it can be positioned at any angle from horizontal to vertical. In high building where the roof area is not enough the co-axial heat pipe solar collectors can be installed on the roof as well as wall of the building. The other advantage is each heat pipe can be topologically disconnected from the manifold. (orig.)

Azad, E. [Iranian Research Organization for Science and Technology (IROST), Advanced Materials and Renewable Energy Department, Tehran (Iran, Islamic Republic of)

2011-12-15

235

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 ? =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

236

CREATING AND USING A SOLAR COLLECTOR FOR TEACHING IN PRIMARY SCHOOL  

Digital Repository Infrastructure Vision for European Research (DRIVER)

these collectors are used for heating the sanitary water. In solar hot air collectors the heating medium is air. They are used for co-heating of closed areas to reduce the consumption of other heating resources. Solar hot air collectors are simpler than water collectors and can be constructed in small workshops, including the ones in primary schools. In the thesis we begin by introducing the most commonly used renewable and non-renewable energy sources. In the main part of the thesis we gi...

Brglez, Peter

2012-01-01

237

Alzeta porous radiant burner. CRADA final report  

Energy Technology Data Exchange (ETDEWEB)

An Alzeta Pyrocore porous radiant burner was tested for the first time at elevated pressures and mass flows. Mapping of the burner`s stability limits (flashback, blowoff, and lean extinction limits) in an outward fired configuration and hot wall environment was carried out at pressures up to 18 atm, firing rates up to 180 kW, and excess air rates up to 100%. A central composite experimental design for parametric testing within the stability limits produced statistically sound correlations of dimensionless burner temperature and NO{sub x} emissions as functions of equivalence ratio, dimensionless firing rate, and reciprocal Reynolds number. The NO{sub x} emissions were below 4 ppmvd at 15% O{sub 2} for all conditions tested, and the CO and unburned hydrocarbon levels were simultaneously low. As a direct result of this cooperative research effort between METC and Alzeta, Solar Turbines has already expressed a strong interest in this novel technology.

NONE

1995-12-01

238

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2011-01-15

239

Reactivities of some thiol collectors and their interactions with Ag (+1) ion by molecular modeling  

International Nuclear Information System (INIS)

The most commonly used collectors for sulfide minerals in the mining industry are the thiol collectors for the recovery of these minerals from their associated gangues by froth flotation. For this reason, a great deal of attention has been paid to understand the attachment mechanism of thiol collectors to metal sulfide surfaces. The density functional theory (DFT) calculations at the B3LYP/3-21G* and B3LYP/6-31++G** levels were employed to propose the flotation responses of these thiol collectors, namely, diethyl dithiocarbamate, ethyl dithiocarbamate, ethyl dithiocarbonate, ethyl trithiocarbonate and ethyl dithiophosphate ions, and to study the interaction energies of these collectors with Ag (+1) ion in connection to acanthite (Ag2S) mineral. The calculated interaction energies, ?E, were interpreted in terms of the highest occupied molecular orbital (HOMO) energies of the isolated collector ions. The results show that the HOMOs are strongly localized to the sulfur atoms and the HOMO energies can be used as a reactivity descriptor for the flotation ability of the thiol collectors. Using the HOMO and ?E energies, the reactivity order of the collectors is found to be (C2H5)2NCS2- > C2H5NHCS2- > C2H5OCS2- > C2H5SCS2- > (C2H5O)(OH)PS2-5O)(OH)PS2-. The theoretically obtained results are in good agreement with the experimental data reported

240

Process heat generation in industrial buildings using solar concentration collectors  

International Nuclear Information System (INIS)

One of the most promising and important applications of solar energy is in the area of process heat generation for industry. While the greater part of the effort in solar research has traditionally been spent on developing devices for domestic use, it has long been recognized that the industrial user has a far greater potential. Apart from the quantities of energy involved, the industrial user is a convenient one and particularly geared for solar energy utilization. The main limitation of the industrial user with regard to solar energy utilization is his need for steam - rather than hot water at temperatures below 100 degrees C. The common flat-plate collectors are inadequate for generating steam and other types of collectors, usually more expensive, have to be employed. This paper describes a study aimed at incorporating a solar collector of a particular design in the roof structure of an industrial building, thereby bringing down the cost. The particular feature of the collector, based on the SRTA Stationary Reflector/Tracking Absorber concept, is a stationary spherical mirror which focuses the solar rays on a small, cylinder-shaped tracking absorber. Industrial roofs are usually constructed of modular elements, mounted on a support structure. It has been suggested to combine the spherical mirror of the collector in the modular roof element, thus obtaining a roof which can serve at the same time as a solar collector. The advantages to doing this are many: The added antages to doing this are many: The added cost of the solar system is reduced since the roof itself provides the structure of its mirrors; the mirrors reduce the insulation requirements of the roof; optimum utilization of the roof area for solar energy collection can be achieved; the mirror surface can be renewed and refurbished in-situ, and there is no need to replace the entire mirror when its reflectivity decreases in time. (author)

 
 
 
 
241

NOx emission characteristics of gas -fired radiant tube flames: The role of partial premixing  

Digital Repository Infrastructure Vision for European Research (DRIVER)

An experimental study of a laboratory natural gas-fired radiant heating tube with quartz walls and a practical burner geometry reveals that confinement of a jet flame in a tube affects its behavior dramatically. Qualitative observations, colors, and visible flame heights demonstrate that the flame burns either as a long, luminous, orange flame or as a very short, blue flame. Wall temperature profiles, global radiation measurements, and an overall energy balance delineate differences in the ra...

Blevins, Linda G.

1996-01-01

242

The radiant of the Leonids meteor storm in 2001  

CERN Document Server

We have measured the radiant of the Leonids meteor storm in November 2001 by using new observational and analysis techniques. The radiant was measured as the intersections of lines which were detected and extrapolated from images obtained at a single observing site (Akeno Observatory, Japan). The images were obtained by two sets of telephoto lenses equipped with cooled CCD cameras. The measured radiant, (R.A., Dec.)=(154$^\\circ$.35, 21$^\\circ$.55) (J2000), is found to be in reasonable agreement with the theoretical prediction by McNaught and Asher (2001), which verifies their dust trail theory.

Torii, K; Yanagisawa, T; Ohnishi, K; Torii, Ken'ichi; Kohama, Mitsuhiro; Yanagisawa, Toshifumi; Ohnishi, Kouji

2002-01-01

243

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

244

Solar collectors with coloured glazing; Sonnenkollektoren mit farbigem Deckglas  

Energy Technology Data Exchange (ETDEWEB)

This article reviews developments at the Laboratory for Solar Energy and Building Technology at the Swiss Federal Institute of Technology (EPFL) in Lausanne, Switzerland, concerning research and development into various coatings for the glazing of solar collectors. Such colouring is quoted as being useful for the better integration of solar collectors in roofs and facades. The aims of the project, which address both the aesthetics and energy-efficiency areas, are discussed. The surface coatings developed and their optical characteristics are examined, as are the choice of materials and the optimisation of such solar heating systems. The use of nano-structured coatings is discussed. A test and simulation installation at the institute is described, and further work, including aspects of coating the collector absorber plates themselves, is discussed.

Wellstein, J.

2007-07-01

245

Experimental parabolic trough collector performance characterization  

Science.gov (United States)

Experimental data from the Collector Module Test Facility at Sandia National Laboratories, Albuquerque, are used to develop a collector performance model and characterize three parabolic trough solar collectors. The independent variables used in the model are selected and fitted to the experimental data using a multiple linear regression technique. The collector model developed accounts for optical performance, including incident angle effects and thermal losses, both linear and nonlinear.

Lukens, L. L.

1981-05-01

246

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

247

Determination of the optimum tilt angle of solar collectors for building applications  

Energy Technology Data Exchange (ETDEWEB)

Solar energy technologies offer a clean, renewable and domestic energy source, and are essential components of a sustainable energy future. This paper deals with the determination of the optimum tilt angle of solar collectors for building applications. The optimum angle is calculated by searching for the values for which the total radiation on the collector surface is a maximum for a particular day or a specific period. An application of the model is done using the experimental data measured for Izmir in Turkey. The best orientation for solar collectors in Izmir is due south. For increasing the utilization efficiency of solar collectors, it is recommended that, if it is possible, the solar collector should be mounted at the monthly average tilt angle and the slope adjusted once a month. (author)

Gunerhan, Huseyin; Hepbasli, Arif [Faculty of Engineering, Department of Mechanical Engineering, Ege University, 35100 Bornova, Izmir (Turkey)

2007-02-15

248

Multiple discharge cylindrical pump collector  

International Nuclear Information System (INIS)

This patent describes an improvement in a method for circulating fluid coolant through a reactor core of a pool-type nuclear reactor having a sealed containment vessel containing a reactor core submersed in a body of liquid coolant. The method for circulating coolant including utilization of a rotary pump including an impeller for producing a highly circumferential flow of cooling fluid and a method for collecting and discharging coolant fluid, the improvement to the method of collecting and discharging coolant fluid including the steps of: producing a substantially uniform circumferential flow of the fluid by directing the flow through a plurality of diffuser vanes and into an annular collector located radially outboard from the impeller. The annular collector having an entirely closed outer periphery; and turning the flow of cooling fluid into a substantially axially direction while maintaining a substantially constant average flow velocity by directing the coolant flow from the annular collector into a plurality of individual passageways located in an axial position relative to the annular collector

249

Solar Buildings: Transpired Air Collectors  

Energy Technology Data Exchange (ETDEWEB)

Transpired air collectors preheat building ventilation air by using the building's ventilation fan to draw fresh air through the system. The intake air is heated as it passes through the perforated absorber plate and up the plenum between the absorber and the south wall of the building. Reduced heating costs will pay for the systems in 3--12 years.

NONE

1998-11-24

250

Simulations of geometry effects and loss mechanisms affecting the photon collection in photovoltaic fluorescent collectors  

Directory of Open Access Journals (Sweden)

Full Text Available Monte-Carlo simulations analyze the photon collection in photovoltaic systems with fluorescent collectors. We compare two collector geometries: the classical setup with solar cells mounted at each collector side and solar cells covering the collector back surface. For small ratios of collector length and thickness, the collection probability of photons is equally high in systems with solar cells mounted on the sides or at the bottom of the collector. We apply a photonic band stop filter acting as an energy selective filter which prevents photons emitted by the dye from leaving the collector. We find that the application of such a filter allows covering only 1% of the collector side or bottom area with solar cells. Furthermore, we compare ideal systems in their radiative limits to systems with included loss mechanisms in the dye, at the mirror, or the photonic filter. Examining loss mechanisms in photovoltaic systems with fluorescent collectors enables us to estimate quality limitations of the used materials and components.

Rau U.

2012-06-01

251

Fresnel concentrating collector  

Science.gov (United States)

An advanced point focusing solar technology demonstrated potential for near term commercialization as a renewable energy technology. The design features combine to produce a highly efficient, low cost, safe, adaptable, durable system which is simple to manufacture, install and maintain.

Rogers, W.; Borton, D.; Rice, M.; Rogers, R.

1981-01-01

252

Semen quality in welders exposed to radiant heat.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Several studies suggest that welding is detrimental to the male reproductive system. Welding fume and radiant heat are of interest as possible causal factors. This study investigates semen quality and sex hormone concentrations among 17 manual metal arc alloyed steel welders with a moderate exposure to radiant heat (globe temperature ranging from 31.1 degrees to 44.8 degrees C), but without substantial exposure to welding fume toxicants. During exposure to heat the skin temperature in the gro...

Raymond, L. W.

1993-01-01

253

Error analysis of thermocouple measurements in the Radiant Heat Facility  

International Nuclear Information System (INIS)

The measurement most frequently made in the Radiant Heat Facility is temperature, and the transducer which is used almost exclusively is the thermocouple. Other methods, such as resistance thermometers and thermistors, are used but very rarely. Since a majority of the information gathered at Radiant Heat is from thermocouples, a reasonable measure of the quality of the measurements made at the facility is the accuracy of the thermocouple temperature data

254

Design Support System for Parabolic Trough Solar Collector  

Directory of Open Access Journals (Sweden)

Full Text Available Parabolic Trough Collector (PTC is special kind of heat exchanger that is able to transfer solar radiation energy to fluid medium that flow through it. Designing a PTC for a specific working condition requires determination of several parameters and referring to a number of design standards and handbooks. Hence, a design support system is required to determine the necessary parameters and simulate different working conditions. Although, a number of design support systems for solar collectors are available in the market, they are either expensive or limited to certain types of solar collectors. This study presents an in-house design simulation software for parabolic trough collector. The simulation software was coded in Microsoft Visual Studio.Net 2010. Through its Graphical User Interface (GUI, the software allows the user to give input parameters, explore built in standards and review outputs. The output parameters include geometric design parameters, heat losses coefficient and efficiencies. The output parameters are important in the initial stage of designing parabolic trough collectors to reduce design time and effort. The results of the simulation software are validated with published experimental and analytical results.

Abraham D. Woldeyohannes

2012-01-01

255

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

256

Radiant heat testing of the H1224A shipping/storage container  

Energy Technology Data Exchange (ETDEWEB)

H1224A weapons containers have been used for years by the Departments of Energy and Defense to transport and store W78 warhead midsections. Although designed to protect the midsections only from low-energy impacts, a recent transportation risk assessment effort has identified a need to evaluate the container`s ability to protect weapons in more severe accident environments. Four radiant heat tests were performed: two each on an H1224A container (with a Mk12a Mod 6c mass mock-up midsection inside) and two on a low-cost simulated H1224A container (with a hollow Mk12 aeroshell midsections inside). For each unit tested, temperatures were recorded at numerous points throughout the container and midsection during a 4-hour 121{degrees}C (250{degrees}F) and 30-minute 1010{degrees}C (1850{degrees}F) radiant environment. Measured peak temperatures experienced by the inner walls of the midsections as a result of exposure to the high-temperature radiant environment ranged from 650{degrees} C to 980{degrees} C (1200{degrees} F to 1800{degrees}F) for the H1224A container and 770 {degrees} to 990 {degrees}C (1420{degrees} F to 1810{degrees}F) for the simulated container. The majority of both containers were completely destroyed during the high-temperature test. Temperature profiles will be used to benchmark analytical models and predict warhead midsection temperatures over a wide range of the thermal accident conditions.

Harding, D.C.; Bobbe, J.G.; Stenberg, D.R.; Arviso, M.

1994-05-01

257

IEA/SPS 500 kW distributed collector system  

Science.gov (United States)

Engineering studies for an International Energy Agency project for the design and construction of a 500 kW solar thermal electric power generation system of the distributed collector system (DCS) type are reviewed. The DCS system design consists of a mixed field of parabolic trough type solar collectors which are used to heat a thermal heat transfer oil. Heated oil is delivered to a thermocline storage tank from which heat is extracted and delivered to a boiler by a second heat transfer loop using the same heat transfer oil. Steam is generated in the boiler, expanded through a steam turbine, and recirculated through a condenser system cooled by a wet cooling tower.

Neumann, T. W.; Hartman, C. D.

1980-05-01

258

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

The objectives of this research were to study the characteristics of mango chips drying using a double plated solar collector. The materials used were sliced mangoes with the thickness of 3, 6, and 8 mm. The equipments used for this research were double plated solar collector, thermocouple, digital balance, thermometer, vacuum oven, and desiccators. The research parameters included the rate of heat energy absorbed by the double plated solar collector, the heat energy losses, the efficiency of...

Safrani; Cahyawan; Ansar

2012-01-01

259

The Collector of a Megawatt Gyrotron with a Static Nonadiabatic Magnetic Field  

Science.gov (United States)

We have developed the concept and design of a collector with a static nonadiabatic magnetic field, which allow one to exclude the influence of pulsed thermal loads and accumulation of nonelastic deformations in the collector body, as well as achieve the nearly uniform distribution of the heat release power density over its surface for an energy load of about 500 W/cm2. Such a collector is characterized by moderate criticality with respect to variations in the electron energy distribution and the effect of an external scattering magnetic field. The decrease in criticality is achieved by choosing the cylindrical shape of the collector and using two pairs of counter-wound low-power solenoids in the collector system.

Denisov, G. G.; Manuilov, V. N.

2013-11-01

260

Super-radiant scattering of dispersive fields  

International Nuclear Information System (INIS)

Motivated by analogue models of classical and quantum field theory in curved spacetimes and their recent experimental realizations, we consider wave scattering processes of dispersive fields exhibiting two extra scattering channels. In particular, we investigate how standard super-radiant scattering processes are affected by subluminal or superluminal modifications of the dispersion relation. We analyse simple (1+1)-dimensional toy models based on fourth-order corrections to the standard second-order wave equation and show that low-frequency waves impinging on generic scattering potentials can be amplified during the process. In specific cases, by assuming a simple step potential, we determine quantitatively the deviations in the amplification spectrum that arise due to dispersion, and demonstrate that the amplification can be further enhanced due to the presence of extra scattering channels. We also consider dispersive scattering processes in which the medium where the scattering takes place is moving with respect to the observer and show that super-radiance can also be manifest in such situations. (paper)

 
 
 
 
261

Radiant-Heat Spray Calcination Studies  

International Nuclear Information System (INIS)

The radiant-heat spray calcination process for conversion of liquid wastes to solids is described and the design of a one-gallon-per-hour spray calcination unit coupled with a small melt pot, capable of being run separately as a pot calciner, is discussed. The units were designed to test the feasibility of the calcination process with actual Purex plant waste in terms of the process as a unit operation, off-gas treatment, fission-product behaviour, condensate and calcined waste characteristics. The entire system was made to fit into an available 7-1/2 ft x 15 ft x 15 ft tall, manipulator-equipped, shielded cell which is also described. Included in the design discussion are: the resistance heating of the spray calciner column, thermal insulation of the column, spray nozzle, method of nozzle replacement, induction heating of the melt pot, radioactivity scanner for the pot, off-gas processing system including condenser, scrubber and filters, off-gas sampling device, liquid sampling device, wash-down system, feed system, instrumentation and control methods. The experience gained in operating the calciners and associated equipment is discussed. Experimental results presented show the effectiveness of off-gas decontamination and behaviour of gross chemical constituents and some specific fission products. (author)

262

Sensitivity analysis of the thermal performance of radiant and convective terminals for cooling buildings  

DEFF Research Database (Denmark)

Heating and cooling terminals can be classified in two main categories: convective terminals (e.g. active chilled beam, air conditioning) and radiant terminals. The mode of heat transfer of the two emitters is different: the first one is mainly based on convection, whereas the second one is based on both radiation and convection. In order to characterise the advantages and drawbacks of the different terminals, steady-state simulations of a typical office room have been performed using four types of terminals (active chilled beam, radiant floor, wall and ceiling). A sensitivity analysis has been conducted to determine the parameters influencing their thermal performance the most. The air change rate, the outdoor temperature and the air temperature stratification have the largest effect on the cooling need (maintaining a constant operative temperature). For air change rates higher than 0.5 ACH, differences between terminals can be observed. Due to their higher dependency on the air change rate and outdoor temperature, convective terminals are generally less energy effective than radiant terminals. The global comfort level achieved by the different systems is always within the recommended range, but differences have been observed in the uniformity of comfort.

Le Dreau, Jerome; Heiselberg, Per

2014-01-01

263

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

Directory of Open Access Journals (Sweden)

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

Lal Kundan

2013-04-01

264

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

DEFF Research Database (Denmark)

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

Chen, Ziqian; Perers, Bengt

2013-01-01

265

Radiant{trademark} Liquid Radioisotope Intravascular Radiation Therapy System  

Energy Technology Data Exchange (ETDEWEB)

RADIANT{trademark} is manufactured by United States Surgical Corporation, Vascular Therapies Division, (formerly Progressive Angioplasty Systems). The system comprises a liquid {beta}-radiation source, a shielded isolation/transfer device (ISAT), modified over-the-wire or rapid exchange delivery balloons, and accessory kits. The liquid {beta}-source is Rhenium-188 in the form of sodium perrhenate (NaReO{sub 4}), Rhenium-188 is primarily a {beta}-emitter with a physical half-life of 17.0 hours. The maximum energy of the {beta}-particles is 2.1 MeV. The source is produced daily in the nuclear pharmacy hot lab by eluting a Tungsten-188/Rhenium-188 generator manufactured by Oak Ridge National Laboratory (ORNL). Using anion exchange columns and Millipore filters the effluent is concentrated to approximately 100 mCi/ml, calibrated, and loaded into the (ISAT) which is subsequently transported to the cardiac catheterization laboratory. The delivery catheters are modified Champion{trademark} over-the-wire, and TNT{trademark} rapid exchange stent delivery balloons. These balloons have thickened polyethylene walls to augment puncture resistance; dual radio-opaque markers and specially configured connectors.

Eigler, N.; Whiting, J.; Chernomorsky, A.; Jackson, J.; Knapp, F.F., Jr.; Litvack, F.

1998-01-16

266

Validation of the uncertainty budget for soft X-ray radiant power measurement using a cryogenic radiometer  

CERN Document Server

The cryogenic radiometer SYRES, a thermal detector based on the electrical substitution principle, has been used as the primary detector standard for radiant power measurement in the ultraviolet, vacuum ultraviolet and soft X-ray spectral ranges. In order to investigate the possibility of radiant energy being deposited in its absorber cavity without being transformed into heat when detecting soft X-rays, SYRES has been directly compared with the electron storage ring BESSY 1, a primary radiometric source standard of calculable spectral radiant power. To this end, the integral radiant power emitted by the storage ring,into a solid angle defined by a high-precision aperture was measured with SYRES. The experiments were conducted at two nominal energies of the circulating electrons, 800 MeV and 340 MeV, to study the influence of the different spectral distributions of the synchrotron radiation. For the original graphite-coated cavity absorber, significant discrepancies were found which could be traced back to th...

Rabus, H; Scholze, F; Thornagel, R; Ulm, G

2002-01-01

267

Analysis and Experimental Tests of a High-Performance Evacuated Tubular Collector  

Science.gov (United States)

A high-performance collector based on the use of all-glass, evacuated tubular collector elements is described and analyzed, and supporting experimental data presented. The collector operated with excellent efficiency at temperatures high enough to drive existing air conditioning units, and showed good performance under diffuse light and low insolation conditions. Collector efficiency was insensitive to operating temperature, ambient temperature, and wind speed. In addition, air, as well as liquid, can be used as the heat transfer fluid, with no significant performance penalty. While the equations governing the useful energy produced can be cast in a form similar to that for flat plate collectors, several important parameters were unique in a number of respects. The loss coefficient was unusually low, while the flow factor and effective insolation were unusually high.

Beekley, D. C.; Mather, G. R., Jr.

1978-01-01

268

77 FR 76959 - Energy Conservation Program: Request for Exclusion of 100 Watt R20 Short Incandescent Reflector...  

Science.gov (United States)

...DEPARTMENT OF ENERGY 10 CFR Part 430 [Docket Number...heat shields are used to reflect radiant energy away from the lamp base. DOE...Heat Shield: A shield reflecting radiant energy from lamp base; Beam...

2012-12-31

269

Use of local convective and radiant cooling at warm environment  

DEFF Research Database (Denmark)

The effect of four local cooling devices (convective, radiant and combined) on SBS symptoms reported by 24 subjects at 28 ?C and 50% RH was studied. The devices studied were: (1) desk cooling fan, (2) personalized ventilation providing clean air, (3) two radiant panels and (4) two radiant panels with one panel equipped with small fans. A reference condition without cooling was tested as well. The response of the subjects to the exposed conditions was collected by computerized questionnaires. The cooling devices significantly (p<0,05) improved subjects’ thermal comfort compared to without cooling. The acceptability of the thermal environment was similar for all cooling devices. The acceptability of air movement and PAQ increased when the local cooling methods were used. The best results were achieved with personalized ventilation and cooling fan. The minimal improvement in PAQ was reported when the radiant panel was used alone. The use of the local cooling devices led to increase of eye irritation. The reported SBS symptoms increased during the exposure time in all studied conditions, i.e. with and without cooling devices. The lowest prevalence of symptoms was with personalized ventilation and with radiant panel with attached fans, which also helped people to feel less fatigue. The SBS symptoms increased the most when the cooling fan, generating movement of polluted room air, was used.

Melikov, Arsen Krikor; Krejcirikova, Barbora

2012-01-01

270

Formal Derivation of Concurrent Garbage Collectors  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Concurrent garbage collectors are notoriously difficult to implement correctly. Previous approaches to the issue of producing correct collectors have mainly been based on posit-and-prove verification or on the application of domain-specific templates and transformations. We show how to derive the upper reaches of a family of concurrent garbage collectors by refinement from a formal specification, emphasizing the application of domain-independent design theories and transform...

Pavlovic, Dusko; Pepper, Peter; Smith, Douglas R.

2010-01-01

271

Depressed collectors for millimeter wave gyrotrons  

International Nuclear Information System (INIS)

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

272

Convective and radiative heat transfer in MHD radiant boilers  

International Nuclear Information System (INIS)

A combined convection-gas radiation, two-zone flow model is formulated for study of the heat transfer characteristics of MHD radiant boilers. The radiative contributions of carbon dioxide, water vapor, potassium atoms, and slag particles are included in the formulation, and are determined by solving the radiation transport equation using the P1 approximation. The scattering and absorption cross section of slag particles are calculated from Mie theory. The model is used to analyze the scale-up of heat transfer in radiant boilers with refractory thickness, wall emissivity, and boiler size, under conditions of a gas composition and slag particle spectrum typical of coal-fired MHD combustion. A design procedure is suggested for sizing radiant boilers so as to achieve required heat extraction rate and to provide a flow residence time that is adequate for decomposition of NO/sub x/ to acceptable levels

273

Multi-stage depressed collector for small orbit gyrotrons  

Science.gov (United States)

A multi-stage depressed collector for receiving energy from a small orbit gyrating electron beam employs a plurality of electrodes at different potentials for sorting the individual electrons on the basis of their total energy level. Magnetic field generating coils, for producing magnetic fields and magnetic iron for magnetic field shaping produce adiabatic and controlled non-adiabatic transitions of the incident electron beam to further facilitate the sorting.

Singh, Amarjit (Greenbelt, MD); Ives, R. Lawrence (Saratoga, CA); Schumacher, Richard V. (Campbell, CA); Mizuhara, Yosuke M. (Palo Alto, CA)

1998-01-01

274

Electrochemically Stable Cathode Current Collectors for Rechargeable Magnesium Batteries  

Energy Technology Data Exchange (ETDEWEB)

Rechargeable Mg batteries are attractive energy storage systems and could bring cost-effective energy solutions. Currently, however, no practical cathode current collectors that can withstand high voltages in Mg2+ electrolytes has been identified and therefore cathode research is greatly hindered. Here we identified that two metals, Mo and W, are electrochemically stable through formation of surface passive layers. The presented results could have significant impacts on the developments of high voltage Mg batteries.

Cheng, Yingwen; Liu, Tianbiao L.; Shao, Yuyan; Engelhard, Mark H.; Liu, Jun; Li, Guosheng

2014-01-01

275

77 FR 28805 - Energy Conservation Program: Test Procedures for Microwave Ovens  

Science.gov (United States)

...heating food by means of microwave energy, DOE concluded in the November...single compartment that uses both radiant heat and microwave energy for cooking would be covered...4\\ (including those with radiant heating elements)...

2012-05-16

276

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 causes an increase in energy efficiency. On the other hand, the exergy efficiency has been obtained, which the fluctuation of exergy efficiency was based on the Nusselt number, collector length and solar intensity level

277

Design, Fabrication and Experimental Testing of Solar Parabolic Trough Collectors with Automated Tracking Mechanism  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper was concerned with an experimental study of parabolic trough collector’s with its sun tracking system designed and manufactured. To facilitate rapid diffusion and widespread use of solar energy, the systems should also be easy to install, operate and maintain. In order to improve the performance of solar concentrator, different geometries and different types of reflectors were evaluated with respect to their optical and energy conversion efficiency. To assure good performance and...

Venkatesh Reddy; Srinath T; Pradeep Kumar K V

2013-01-01

278

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

279

The radiant ephemerides of kappa-Cygnids from the IMO video database  

Science.gov (United States)

The analysis of single-station IMO video network data of the July and August period with 36 576 meteors in search of kappa-Cygnid, alpha-Lyrid and zeta-Draconid meteor showers was made using the program Radiant. These showers will be named kappa-Cygnid meteor complex radiants. The detailed analysis of the whole August period from 1993-2004 included the behavior of radiants in different magnitude ranges and different years from 2000 on. Detailed radiant calculations for different velocities for 5g and 10g solar longitude intervals were also done. In 10g solar longitude intervals also the calculations for different magnitude ranges were conducted. The activity of the kappa-Cygnid radiant and the alpha-Lyrid radiant was proven, unlike the zeta-Draconid radiant, where no activity could be confirmed. For the whole August period also the behavior of radiants in separate years 2000-2004, when day-to-day meteor coverage is available, was made. From that it can be hinted on alternating bigger activity of the kappa-Cygnid and alpha-Lyrid radiants. In the years 2000 and 2001 the alpha-Lyrid radiant is more active, when on the contrary in 2002, 2003 and 2004 the kappa-Cygnid radiant is more active. The year 2003 is interesting from another aspect, as three radiants can be seen. If the third radiant is the zeta-Draconid radiant, a few years more video observations will have to be gathered and the radiant calculations repeated. For the day of the kappa-Cygnid meteor complex maximum, on August 18, the mean radiant positions were deduced: the more active kappa-Cygnid radiant lies at alpha=280 deg and delta=+58 deg with an area of the maximum probability of 10 deg x 15 deg, and the less active alpha-Lyrid radiant is placed at alpha=292 deg and delta=+52 deg with a radius of maximum probability of 2 deg. The radiant drift was not possible to obtain as in the 5 deg and 10 deg solar longitude interval calculations the positions of both radiants apparently oscillate. As no change can be seen in the position of the radiants and their appearance when changing the velocity, it can be concluded that they present subbranches of the kappa-Cygnid meteor complex radiant.

Triglav-Cekada, Mihaela

2006-08-01

280

Energy conservation and solar energy utilization for greenhouses  

Energy Technology Data Exchange (ETDEWEB)

Several studies were undertaken to evaluate the effectiveness of different greenhouse glazing materials, thermal blankets, radiant heat and solar energy in reducing the fossil fuel heat requirements of conventional glasshouses. Double layer glazings reduced heat requirements 25 to 50 percent depending on the material. Thermal blankets were also effective in reducing heat losses. A combined double layer glazing-thermal blanket system reduced the heat requirement of a single layer lapped-glass structure by 70%. Radiant heating reduced energy requirements significantly. Excess solar heat collection within greenhouse structures was shown to be ineffective in northern climates, due to low net radiation flux densities. Flat plate solar collectors provided significant portions of the total heat requirement of double glazed greenhouses during the spring and fall portions of the heating season. Fresh weight, stem length and total flower production was altered significantly when double layer glazings were used in place of glass. Dry weight accumulations of chrysanthemums were observed to be functions of solar radiation and temperature. Highest dry weight accumulations were observed when single layer lapped-glass was the greenhouse glazing.

Sherry, W.J.; White, J.W.; Schmidt, F.W.; Sanders, G.A.

1981-01-01

 
 
 
 
281

Effects of low reflection on the collector and source sheaths of a finite ion temperature plasma  

International Nuclear Information System (INIS)

The region between a Maxwellian plasma source and an absorbing surface which reflects a fraction of the incident ions is modeled numerically with dynamic, electrostatic particle simulation and theoretically with a static, kinetic plasma-sheath model. The fraction /zeta/ of ions reflected is varied from 0 to 0.6 which generally increases both the potential drop from the source to the collector and the energy transported to the collector surface. Results from both models agree well when the fraction reflected is less than 0.4 for full energy transfer to reflected ions. With larger fractions and with slightly less than full reflected energy, simulations show an ion-ion two-streaming interaction which slightly reduces the collector potential drop and decreases the ion energy deposited on the collector surface relative to predictions from the static theory. According to theory, for a deuterium-tritium plasma, a collector material causing the reflected ion fraction to be /zeta/ = 0.2 with full reflected energy increases the magnitude of collector potential by 12% and the ion energy deposited by 6% over those predicted when /zeta/ = 0

282

Incidental solar radiation according to the solar collector slope : horizontal measurements conversion on an inclined panel laws  

Energy Technology Data Exchange (ETDEWEB)

Solar water heaters are in need of improvement, as they are known to be overheated in the summer and are unsatisfactory in the winter. The purpose of this paper was to determine the incidental solar energy on a collector for various slopes and with various orientations, which could be generalized with the solar water, photovoltaic panel and air collectors, and with the walls of a building. The paper presented the computational model and subsequent results and discussion. This included the ideal tilt angle of the solar collectors according to the date; flux received by the collector according to the slope and of the period of usage; received solar flux by the collector according to the date and various inclinations; energy received according to the date for various inclinations of the solar collector; received energy according to the inclination of the collector and the period of use; and influence of albedo on received energy. The paper also addressed the conversion, on an inclined collector, of the horizontal measurements provided by the weather stations. It was concluded that the measurement of solar incident energy is necessary for the optical performance of photovoltaic or thermal solar installations. 25 refs., 8 figs., 1 appendix.

Slama, R.B. [ISSAT Gabes, Gabes (Tunisia). Dept. of Electromecanique

2009-07-01

283

Characterization of a pulsed electron beam with a planar charge collector  

Energy Technology Data Exchange (ETDEWEB)

Pulsed electron beams produced by a photocathode source in the 1-10 keV energy range have been experimentally characterized by means of an electrostatic diagnostic system. A Malmberg-Penning trap in an open configuration, equipped with a planar charge collector has been used for the experiments. The relevant physical properties of the beams and their dependence on the injection conditions have been inferred through the numerical analysis of the electric signal measured across the overall load impedance of the charge collector. The indirect measurement technique presented here gives a general method to overcome the resolution limits of capacitive charge collectors.

Paroli, B; Bettega, G; Cavaliere, F; De Luca, F; Maero, G; Pozzoli, R; Rome, M [INFN Sezione di Milano and Dipartimento di Fisica, Universita degli Studi di Milano, Via Celoria 16, 20133 Milano (Italy); Cavenago, M [INFN Laboratori Nazionali di Legnaro, Viale dell' Universita 2, 35020 Legnaro (Italy); Svelto, C [Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia and Dipartimento di Elettronica e Informazione, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)

2009-09-07

284

Solar Technology: Evacuated Tube Solar Collector  

Science.gov (United States)

This is a brief flash animation that provides an overview of the components in an Evacuated Tube Solar Collector. It also explains how these components maximize effectiveness of this type of solar collector as well as some advantages and disadvantages to this design. Note: this video may be slow to load when viewing for the first time.

2012-10-16

285

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

286

Weathering of a liquid solar collector  

Science.gov (United States)

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

1980-01-01

287

Prevailing hydrophobic nature of petroleum bed collectors  

Energy Technology Data Exchange (ETDEWEB)

The nature of wettability of collectors (primarily terrigenous) oil beds and the shape of the occurrence of residual water in pores are studied. Evidence is presented for the fact that the collectors being examined are actually hydrophobic, their grains are coated with a highly viscous petroleum film, and the remaining water is mobile.

Ashirov, K.B.; Ashirova, G.K.; Fedosova, O.I.; Panilova, N.I.; Tsivinskoya, L.V.

1982-01-01

288

Quantum Phase Transition in Ultracold 87Rb Atom Gas with Radiant Field  

CERN Document Server

A second-order quantum phase transition in two-species Bose-Einstein condensates of 87Rb atoms coupled by a quantized radiant field is revealed explicitly in terms of the energy spectrum which is obtained in the thermodynamic limit and is controllable by the coupling parameter between the atom and field. The scaling behavior of the collective excitation modes at the critical transition point is seen to be in the same universality class as that of the Dicke model. It is also demonstrated that the quantum phase transition is realizable below the critical temperature of BEC and can be detected experimentally by measuring the abrupt change of atom population imbalance.

Chen, G; Liu, W M; Chen, Gang

2006-01-01

289

Evaluation of Test Method for Solar Collector Efficiency  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

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

2012-01-01

290

Comparative Study on Solar Collector’s Configuration for an Ejector-Refrigeration Cycle  

Directory of Open Access Journals (Sweden)

Full Text Available Solar collector’s configuration plays important role on solar-powered refrigeration systems to work as heat source for generator. Three types of solar collector consisting of flat plate, evacuated tube, and compound parabolic solar collectors are compared to investigate their performances. The performances consist of the behavior of heat which can be absorbed by the collectors, heat loss from the collectors and outlet temperature of working fluid at several slopes of the solar collectors. The new accurate analysis method of heat transfer is conducted to predict the performance of the solar collectors. The analysis is based on several assumptions, i.e. sky condition at Bandung is clear and not raining from 08.00 until 17.00 and thermal resistance at cover and absorber plate is negligible. The numerical calculation results confirm that performance of the evacuated tubes solar collector at the same operating conditions is higher than the others. For the case of an evacuated-tubes solar collector system with aperture area of 3.5 m2, the maximum heat which can be absorbed is 3992 W for the highest solar intensity of 970 W/m2 at 12.00 and horizontal position of the solar collector. At this condition, the highest outlet temperature of water is 347.15 K with mass flow rate 0.02 kg/s and inlet temperature 298 K.

Raffles Senjaya

2008-05-01

291

Development and evaluation of a fallout collector  

Energy Technology Data Exchange (ETDEWEB)

The objective of Project 2.13 was to develop and evaluate a new fallout collector. This project participated in Operation Sunbeam, Shot Small Boy. Fallout collectors were installed adjacent to Project 2.9 manned instrument stations at 7,200, 15,600, and 28,000 feet in the expected downwind direction from ground zero. The principal areas for which data were obtained were (1) design, procurement, and fabrication of fallout collectors; (2) field operational performance of the instruments; and (3) analysis of fallout samples. A discussion of the data obtained is presented. From a mechanical and operational analysis, it was concluded that the fallout collector evaluated was satisfactory for use on future fallout projects at Nevada Test Site (NTS). However, sample analysis data obtained were insufficient for final evaluation of collector sampling efficiency.

Schumchyk, M.J.; Crisco, C.

1963-10-18

292

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

Energy Technology Data Exchange (ETDEWEB)

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. (author)

Sarhaddi, F.; Farahat, S.; Ajam, H.; Behzadmehr, A.; Mahdavi Adeli, M. [Department of Mechanical Engineering, Shahid Nikbakht Faculty of Engineering, University of Sistan and Baluchestan, Zahedan 98164-161 (Iran)

2010-07-15

293

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 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.

294

76 FR 12825 - Energy Conservation Program for Consumer Products: Test Procedure for Microwave Ovens  

Science.gov (United States)

...product that utilizes radiant as well as microwave energy would be a covered...which primarily uses radiant heat for cooking...supplemented by microwave energy would be covered...mode (i.e., radiant heating or microwave energy) is primary....

2011-03-09

295

76 FR 72332 - Energy Conservation Program: Test Procedure for Microwave Ovens  

Science.gov (United States)

...primary (i.e., radiant heating or microwave energy) and that all ovens...product that uses radiant heat for cooking, but also uses microwave energy as a secondary cooking...compartment that uses both radiant heat and microwave energy for cooking...

2011-11-23

296

Clouds and the Earth's Radiant Energy System (CERES) algorithm theoretical basis document. volume 4; Determination of surface and atmosphere fluxes and temporally and spatially averaged products (subsystems 5-12); Determination of surface and atmosphere fluxes and temporally and spatially averaged products  

Science.gov (United States)

The theoretical bases for the Release 1 algorithms that will be used to process satellite data for investigation of the Clouds and the Earth's Radiant Energy System (CERES) are described. The architecture for software implementation of the methodologies is outlined. Volume 4 details the advanced CERES techniques for computing surface and atmospheric radiative fluxes (using the coincident CERES cloud property and top-of-the-atmosphere (TOA) flux products) and for averaging the cloud properties and TOA, atmospheric, and surface radiative fluxes over various temporal and spatial scales. CERES attempts to match the observed TOA fluxes with radiative transfer calculations that use as input the CERES cloud products and NOAA National Meteorological Center analyses of temperature and humidity. Slight adjustments in the cloud products are made to obtain agreement of the calculated and observed TOA fluxes. The computed products include shortwave and longwave fluxes from the surface to the TOA. The CERES instantaneous products are averaged on a 1.25-deg latitude-longitude grid, then interpolated to produce global, synoptic maps to TOA fluxes and cloud properties by using 3-hourly, normalized radiances from geostationary meteorological satellites. Surface and atmospheric fluxes are computed by using these interpolated quantities. Clear-sky and total fluxes and cloud properties are then averaged over various scales.

Wielicki, Bruce A. (Principal Investigator); Barkstrom, Bruce R. (Principal Investigator); Baum, Bryan A.; Charlock, Thomas P.; Green, Richard N.; Lee, Robert B., III; Minnis, Patrick; Smith, G. Louis; Coakley, J. A.; Randall, David R.

1995-01-01

297

Owens--Illinois liquid solar collector materials assessment  

Energy Technology Data Exchange (ETDEWEB)

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.

Nichols, R. L.

1978-03-01

298

Solar Thermal Systems Performances versus Flat Plate Solar Collectors Connected in Series  

Directory of Open Access Journals (Sweden)

Full Text Available This paper shows the modeling of a solar collective heating system in order to predict the system performances. Two systems are proposed: 1 the first, Solar Direct Hot Water, which is composed of flat plate collectors and thermal storage tank, 2 the second, a Solar Indirect Hot Water in which we added an external heat exchanger of constant effectiveness to the first system. The mass flow rate by a collector is fixed to 0.04 Kg?s–1 and the total number of collectors is adjusted to 60. For the first system, the maximum average water temperature within the tank in a typical day in summer and annual performances are calculated by varying the number of collectors connected in series. For the second, this paper shows the detailed analysis of water temperature within the storage and annual performances by varying the mass flow rate on the cold side of the heat exchanger and the number of collectors in series on the hot side. It is shown that the stratification within the storage is strongly influenced by mass flow rate and the connections between collectors. It is also demonstrated that the number of collectors that can be connected in series is limited. The optimization of the mass flow rate on cold side of the heat exchanger is seen to be an important factor for the energy saving.

Khaled Zelzouli

2012-12-01

299

Performance of solar collectors under low temperature conditions : Measurements and simulations results  

DEFF Research Database (Denmark)

The performance of four solar thermal collectors (flat plate, evacuated tube, unglazed with rear insulation and unglazed without rear insulation) was experimentally measured and simulated for temperatures below ambient. The influence of several parameters (e.g. collector inlet temperature, air temperature, condensation) is investigated under different operating conditions (day and night). Under some conditions condensation might occur and heat gains could represent up to 55% of the total unglazed collector energy by night. Two TRNSYS collector models including condensation heat gains are also evaluated and results compared to experimental measurements. A mathematical model is also under development to include, in addition to the condensation phenomena, the frost, the rain and the long-wave radiation gains/losses on the rear of the solar collector. While the potential gain from rain was estimated to be around 2%, frost heat gains were measured to be up to 40% per day, under specific conditions. Overall, results have shown that unglazed collectors are more efficient than flat plate or evacuated tube collectors at low operation temperatures or for night conditions, making them more suitable for heat pump applications.

Bunea, Mircea; Eicher, Sara

300

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%.

 
 
 
 
301

Shape control of solar collectors using torsional shape memory alloy actuators  

Energy Technology Data Exchange (ETDEWEB)

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 will be 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 small 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. In order to accommodate the large, nonlinear deformations required in the solar collector plate to obtain desired focal lengths, a torsional shape memory alloy actuator was developed that produces a stroke of 0.5 inches. 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.

Lobitz, D.W.; Rice, T.M.; Grossman, J.W. [and others

1996-03-01

302

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2012-07-01

303

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

Directory of Open Access Journals (Sweden)

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

Madhukeshwara. N, E. S. Prakash

2012-01-01

304

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

Energy Technology Data Exchange (ETDEWEB)

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 showing thermochromic switching behaviour have been produced at EPFL. These coatings switch from a semiconducting to a metallic state at critical temperatures around 65 {sup o}C, as indicated by a resistivity change of typically three orders of magnitude. (author)

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

2008-01-15

305

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.

306

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 are supplied with inspections of the collectors inclusive investigations of possible corrosion of the copper pipes of the absorbers of the collectors. It is shown that from 2002 to 2007 the thermal performance of solar collector has been increased by 29%, 39%, 55% and 80% for a mean solar collector fluid temperature of 40?C, 60°C, 80°C and 100°C respectively due to improvement of the collector design. The test of the two collectors shows that due to aging the Ottrupgård collector has a yearly thermal performance which is 4% lower than for the collector tested in 1991 for a solar collector fluid temperature of 45°C, while the Marstal collector has a yearly thermal performance which is 1% lower than the collector tested in 1991. With an increase of the solar collector fluid temperature to 60°C, the yearly thermal performance of the Ottrupgård collector and the Marstal collector is respectively 11% and 10% lower than the collector tested in 1991. Keywords: Flat plate solar collector, Collector efficiency, Efficiency test, Lifetime, Solar heating plants.

Fan, Jianhua; Chen, Ziqian

2009-01-01

307

Mobile Collector for Field Trips  

Directory of Open Access Journals (Sweden)

Full Text Available Current e-Learning is based on learning management systems that provide certain standard services - course authoring and delivery, tutoring, administration and collaboration facilities. Rapid development of mobile technologies opens a new area of m-Learning to enhance the current educational opportunities. Field trips are a relevant part of the curriculum, but for various reasons it is often difficult to organize them. The aim of the RAFT project is development of a system that would enable virtual field trips. One mobile learning application prototype created in this project, called Mobile Collector, enables data gathering and annotation in the field, together with real time collaboration. The application supports learner-centred education in real world context.

Lucia Terrenghi

2004-04-01

308

A finite-volume model of a parabolic trough photovoltaic/thermal collector: Energetic and exergetic analyses  

International Nuclear Information System (INIS)

This paper presents a detailed finite-volume model of a concentrating photovoltaic/thermal (PVT) solar collector. The PVT solar collector consists in a parabolic trough concentrator and a linear triangular receiver. The bottom surfaces of the triangular receiver are equipped with triple-junction cells whereas the top surface is covered by an absorbing surface. The cooling fluid (water) flows inside a channel along the longitudinal direction of the PVT collector. The system was discretized along its axis and, for each slice of the discretized computational domain, mass and energy balances were considered. The model allows one to evaluate both thermodynamic and electrical parameters along the axis of the PVT collector. Then, for each slice of the computational domain, exergy balances were also considered in order to evaluate the corresponding exergy destruction rate and exergetic efficiency. Therefore, the model also calculates the magnitude of the irreversibilities inside the collector and it allows one to detect where these irreversibilities occur. A sensitivity analysis is also performed with the scope to evaluate the effect of the variation of the main design/environmental parameters on the energetic and exergetic performance of the PVT collector. -- Highlights: ? The paper investigates an innovative concentrating photovoltaic thermal solar collector. ? The collector is equipped with triple-junction photovoltaic layers. ? A local exergetic analysis is performed in order to detect sources of irreversibilities. ? Irreversibilities are mainly due to the heat transfer between sun and PVT collector.

309

Performances of Low Temperature Radiant Heating Systems  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Low temperature heating panel systems offer distinctive advantages in terms of thermal comfort and energy consumption, allowing work with low exergy sources. The purpose of this paper is to compare floor, wall, ceiling, and floor-ceiling panel heating systems in terms of energy, exergy and CO2 emissions. Simulation results for each of the analyzed panel system are given by its energy (the consumption of gas for heating, electricity for pumps and primary energy) and exergy co...

Bojic?, Milorad; Cvetkovic, Dragan; Skerlic?, Jasmina; Nikolic?, Danijela; Boyer, Harry

2013-01-01

310

Numerical modelling of a parabolic trough solar collector  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Concentrated Solar Power (CSP) technologies are gaining increasing interest in electricity generation due to the good potential for scaling up renewable energy at the utility level. Parabolic trough solar collector (PTC) is economically the most proven and advanced of the various CSP technologies. The modelling of these devices is a key aspect in the improvement of their design and performances which can represent a considerable increase of the overall efficiency of solar power plants. In the...

Hachicha, Ahmed Amine

2013-01-01

311

Field evaluation of performance of radiant heating/cooling ceiling panel system  

DEFF Research Database (Denmark)

As in many other countries in the world, Japan has witnessed an increased focus on low-energy buildings.For testing different engineering solutions for energy-efficient buildings, a low-energy building was builtat the University of Tokyo as an experimental pilot project. In this building, a radiant heating/coolingceiling panel system is used. However, no standard exists for the in situ performance evaluation of radiantheating/cooling ceiling systems; furthermore, no published database is available for comparison. Thus,this study aims to not only clarify the system performance but also to share our experience and our resultsfor them to serve as a reference for other similar projects. Here, the system performance in relation toits heating/cooling capacity and thermal comfort has been evaluated. The heat transfer coefficient fromwater to room was 3.7 W/(m2K) and 4.8 W/(m2K) for heating and cooling cases, respectively. The upwardheat flux from the panels was found to be as large as 30–40% of the water heating/cooling capacity; thiswould translate into heat loss in certain operating modes. Several proposals for reducing the upwardheat flux were discussed. The measurements also showed that a category B thermal environment wasobtained using the radiant ceiling heating/cooling system.© 2014 Elsevier B.V. All rights reserved.

Li, Rongling; Yoshidomi, Togo

2015-01-01

312

Radiant burner technology base B burner research and development. Final report, February 1986-January 1989. Appendix M. Arizona State University final report: Emission measurements of porous radiant burners  

Energy Technology Data Exchange (ETDEWEB)

Radiant burners offer many advantages to industrial users and there are numerous applications that would benefit from the technology. Industrial operations, however, place severe restrictions on the use of radiant burners. These limits are related to high furnace temperatures, varied production schedules, and dirty work environments. The work has identified operational and materials limits of present day radiant burner technologies and has projected what their capabilities may be. The results of the report recommend techniques to improve the state-of-the-art in radiant burners and increasing the number of industrial applications for the gas-fired burner.

1989-03-01

313

Theoretical and experimental study of solar thermal collector systems and components  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Flat-plate and evacuated tube collectors are the most widely used device to convert solar radiation into heat. In conventional applications they can provide energy for domestic hot water or space heating in combination with low water temperature systems. Testing of thermal efficiency and optimisation of these solar thermal collectors are addressed and discussed in the present work. A new set of experimental data has been used to evaluate the performance of flat-plate and evacuated colle...

Zambolin, Enrico

2011-01-01

314

Modeling Spatio-Temporal Dynamics of Optimum Tilt Angles for Solar Collectors in Turkey  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Quantifying spatial and temporal variations in optimal tilt angle of a solar collector relative to a horizontal position assists in maximizing its performance for energy collection depending on changes in time and space. In this study, optimal tilt angles were quantified for solar collectors based on the monthly global and diffuse solar radiation on a horizontal surface across Turkey. The dataset of monthly average daily global solar radiation was obtained from 158 places, and monthly diffuse...

Recep Kulcu; Fatih Evrendilek; Can Ertekin

2008-01-01

315

Experimental Comparison of Two Configurations of Hybrid Photovoltaic Thermal Collectors  

International Nuclear Information System (INIS)

The combination of a thermal collector and a photovoltaic module in a single system allows for increased efficiency of the total conversion of solar energy. A synergistic effect can be obtained in a structure combining these two devices in a judicious manner to those of thermal and photovoltaic system installed separately. Production of total energy from hybrid collector depends on the input (that is to say, the. energy of solar radiation, air temperature and wind speed) and output which is the electric production and the temperature of the system. Thin production also depends on the mode of heal extraction. In this paper, an experimental Study of two configurations of hybrid collectors is described. The configuration that the absorber is made by galvanized steel and in the second, the absorber is a copper serpentine. The advantages of the first configuration are mainly due to low cost and simplicity but the second configuration has the advantage of promoting the heat transfer between cells and fluid. (authors)

316

Single-stage depressed collectors for gyrotrons  

International Nuclear Information System (INIS)

Two 140 GHz gyrotrons with a single-step depressed collector have been operated. The different position of the isolating collector gap in the stray magnetic field causes the electron motion in the retarding region to be in one case adiabatic and in the other case nonadiabatic. The kind of motion within the retarding field influences strongly the behavior of the gyrotron with a depressed collector. In the case of nonadiabatic motion a significant amount of transverse momentum is given to the electrons reflected at the collector potential. This causes the reflected electrons to be trapped between the magnetic mirror and the collector. The electrons escape from the trap by diffusion across the magnetic field to the body of the tube thus contributing to the body current. Despite the high body current there is no observable influence of the collector voltage on the RF output power. In the case of adiabatic motion the reflected electrons do not gain a sufficient amount of transverse momentum to be trapped by the magnetic mirror. They pass the cavity toward the gun and they are trapped between the negative gun potential and the collector. The interaction with the RF field by electrons traveling through the cavity enhances the diffusion in the velocity space thus enabling the trapped electrons to overcome the potential barrier and escape toward the collector. Therefore the body current stays at low values since in this case the reflected electrons do not contribute to it. Howted electrons do not contribute to it. However, at higher collector voltages a reduction of RF power occurred and some noise in the electron beam was observed. The main motivation for the development of gyrotrons in the frequency range above 100 GHz with power levels in excess of several hundreds kW per tube, is the application in magnetic fusion devices for plasma heating and for electron current drive

317

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

International Nuclear Information System (INIS)

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

318

Formal Derivation of Concurrent Garbage Collectors  

CERN Document Server

Concurrent garbage collectors are notoriously difficult to implement correctly. Previous approaches to the issue of producing correct collectors have mainly been based on posit-and-prove verification or on the application of domain-specific templates and transformations. We show how to derive the upper reaches of a family of concurrent garbage collectors by refinement from a formal specification, emphasizing the application of domain-independent design theories and transformations. A key contribution is an extension to the classical lattice-theoretic fixpoint theorems to account for the dynamics of concurrent mutation and collection.

Pavlovic, Dusko; Smith, Douglas R

2010-01-01

319

75 FR 25228 - Energy Conservation Program for Consumer Products: Decision and Order Denying a Waiver to PB Heat...  

Science.gov (United States)

...unrepresentative of its true energy consumption characteristics...baseboard convector or radiant floor heating systems...unrepresentative of their true energy consumption characteristics...boiler is used with radiant floor heating systems...installed with either radiant floor heating systems...efficiency and reduced energy use, during...

2010-05-07

320

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 alteand', '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

 
 
 
 
321

Experimentation of a Plane Solar Integrated Collector Storage Water Heater  

Directory of Open Access Journals (Sweden)

Full Text Available In order to popularize the use of the solar-water heaters, especially in the residential and tertiary sectors with the third world, it appears to be necessary to reduce their cost while improving their performances. It is the object of this integrated storage collector thus created and tested in the south of Tunisia. It is simply made up of a tank playing the double part of solar absorber and storage tank of warm water, of a glazing to profit from the greenhouse effect and of an insulating case. Its measured energy performances, by the method of input-output proves its effectiveness to produce hot water, in spite of its simplicity of manufacture, usage and maintenance. Indeed a temperature of water exceeding 70?C is reached towards the afternoon True Solar Time, and for an efficiency of 7%. Thus, this type of collector with integrated storage is entirely satisfactory and could be available to larger mass.

Romdhane Ben Slama

2012-03-01

322

Thermal performance predictions of flat-plate solar collector air heaters  

Science.gov (United States)

A computer program was written that models heat exchanges occurring within flat plate solar air collectors and which computes the incoming solar flux and heat losses to the environment. Internal collector temperatures and thermal efficiencies are predicted for either steady state or transient cases from finite difference solutions to a set of energy balance equations. These relations are written for thermal modes that are generated and linked together by the internal deck logic. The program was utilized in a study of three types of air collectors. The first two configurations employed crossflow impingement along the backside of their absorbers to augment heat transfer coefficients developed at those surfaces, while the third used a rock matrix absorber to expand its surface area for heat transfer. In addition, the first collector replaced the conventional stationary plate absorber of the second design by a traveling belt.

Oneill, T. C.

1980-03-01

323

Asymmetric Laser Radiant Cooling in Storage Rings  

CERN Document Server

Laser pulses with small spatial and temporal dimensions can interact with a fraction of the electron bunches circulating in Compton storage rings. We studied synchrotron dynamics of such bunches when laser photons scatter off from the electrons with energy higher than the synchronous energy. In this case of ‘asymmetric cooling', as shown theoretically, the stationary energy spread is much smaller than under conditions of regular scattering; the oscillations are damped faster. Coherent oscillations of large amplitude may be damped in one synchrotron period, which makes this method feasible for injection the bunches into a ring in the longitudinal phase space. The theoretical results are validated with simulations.

Bulyak, E V; Zimmermann, F

2011-01-01

324

Grid Collector: Facilitating Efficient Selective Access from DataGrids  

Energy Technology Data Exchange (ETDEWEB)

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.

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

2005-05-17

325

Maximization od solar energy per square meter by means of PVT (Photovoltaic thermal hybrid solar collectors). Sustainable heating system for Rijksgebouwendienst Zoetermeer, Netherlands; Maximalisering zonne-energie per vierkante meter met PVT. Duurzaam verwarmingssysteem Rijksgebouwendienst Zoetermeer  

Energy Technology Data Exchange (ETDEWEB)

An office building of the Dutch Government Buildings Agency (RGD) in Zoetermeer, Netherlands, is monitored to determine the feasibility of PVT (Photovoltaic thermal hybrid solar collectors) panels. The PVT system is connected to the hot tap water system. The aim is to be able to calculate reliable yields and to test the applicability for the Netherlands [Dutch] Een kantoorgebouw van de Rijksgebouwendienst in Zoetermeer is gemonitord om de haalbaarheid van PVT-panelen (fotovoltaische thermische hybride zonnecollectoren) te bepalen. Het PVT-systeem is aangesloten op het warmtapwaterysteem. Het doel is betrouwbare opbrengsten te kunnen berekenen en de toepasbaarheid voor Nederland te testen.

Van Helden, W. [Renewable Heat, Schagen (Netherlands); Roossien, B. [EnergyGO, Den Helder (Netherlands); Mimpen, J. [Rijksgebouwendienst, Zoetermeer (Netherlands)

2013-02-15

326

Exergetic performance assessment of a solar photovoltaic thermal (PV/T) air collector  

Energy Technology Data Exchange (ETDEWEB)

In this paper, an attempt is made to evaluate the exergetic performance of a solar photovoltaic thermal (PV/T) air collector. A detailed energy and exergy analysis is carried out to calculate the thermal and electrical parameters, exergy components and exergy efficiency of a typical PV/T air collector. Some corrections are done on related heat loss coefficients. An improved electrical model is used to estimate the electrical parameters of a PV/T air collector. Further, a modified equation for the exergy efficiency of a PV/T air collector is derived in terms of design and climatic parameters. A computer simulation program is also developed 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. It is observed that the modified exergy efficiency obtained in this paper is in good agreement with the one given by the previous literature. It is also found that the thermal efficiency, electrical efficiency, overall energy efficiency and exergy efficiency of PV/T air collector is about 17.18%, 10.01%, 45% and 10.75% respectively for a sample climatic, operating and design parameters. (author)

Sarhaddi, F.; Farahat, S.; Ajam, H.; Behzadmehr, A. [Department of Mechanical Engineering, Shahid Nikbakht Faculty of Engineering, University of Sistan and Baluchestan, Zahedan 98164-161 (Iran, Islamic Republic of)

2010-11-15

327

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

328

Technical and economical assessment of integrated collector storage solar water heaters  

International Nuclear Information System (INIS)

Solar water heating implementation has as effect greenhouse gas emission reduction. Romanian solar collector market and solar technologies implementation are not yet developed because the market is dominated by high cost equipment. Due to this, the author deduces that the use of simpler technologies, with lower technical performances, but inferior capital cost, will induce higher solar energy penetration into the market. One of the cheapest solutions for solar water heating is Integrated Collector Storage Solar Water Heaters technology. The author purpose an analytical method for technical and economical solar collector's performance assessment. Technical performances of the solar collectors will be compared for different types of ICSSWH's. Systems calculation will be done analytically. The starting point of the estimation is the heat balance on solar collector's boundary. Using heat transfer equation, energy fluxes and equipment efficiencies during collection and store time can be calculated. Technical performances for market existing solar collectors will be reminded. The paper conclusions are valuable for solar hot water design. (author)

329

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

Science.gov (United States)

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

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

2012-06-01

330

Energy savings in dust collector plants of bag house filter type. Phase 1 - Literature study; Energieffektivisering av anlaeggningar foer stoftrening med slangfilter. Etapp 1-Litteraturstudie  

Energy Technology Data Exchange (ETDEWEB)

The largest energy demands in connection with the operation of bag house filters are the electric energy consumption for the fans, securing the flow of flue gas through the filter, and the electric energy consumption when producing the pressurized air (compressors or high pressure fans). Considering the significantly increased fan work when having a non-optimised cleaning of the filters, it seems justified to investigate the possibilities to minimise the unnecessary pressure drop. There is also a saving potential in the filter cleaning process, which otherwise may cost an unacceptable amount of pressurized air or other energy. The main purpose of this work is to develop methods to optimize the operation of bag house filters, which is started up with this report containing a follow-up of what has been done in Denmark and a confirmation of the technology status. In the next step, a case study where two-three plants are examined more in detail is suggested followed by a potential study to estimate the total energy saving potential in Sweden. Dust precipitation with bag house filters is basically a rather simple technique, which has existed in flue gas cleaning for about 50 years. From the literature study it can be established that there has been no revolutionary development in the field, but there are some work being done mainly to introduce new filter material but also to optimise the use of bag house filters with new computer based control systems. The largest potential of energy saving prevails if the filter from the beginning is overloaded, which usually is the case. The reason for overload may be a too large volume flow in relation to the filter area, that the dust has penetrated and blocked the filter, a defective filter cleaning process or that wrong filter material has been chosen. In Denmark a study has been made with the purpose to investigate the possibilities to optimise the energy consumption for bag house filters. For the three plants studied, an average energy saving of 50% was noted by exchange of filter material and improvement of the cleaning process. Other plants in Denmark have been rebuilt during the latest years but for these plants no reports have been found concerning how efficient the measures have been regarding energy demand for the filters. Today the suppliers of bag house filters have refined the control systems for the on-line cleaning of the filters. The systems differs in advance but are usually based on minimising the pressure drop on the flue gas side by keeping the dust layer thickness on the filter constant on the smallest possible level considering the flue gas dust emission. Very often this is combined with minimising the energy consumption of the cleaning process. Also the consumption of chemicals (for example limestone, active coal) are minimised by these control systems, which mainly in larger plants may be prior to minimising the electric energy consumption.

Eriksson, Lars; Wikman, Karin; Berg, Magnus [AaF-Energi and Miljoe AB, Stockholm (Sweden)

2004-01-01

331

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)

332

Collector/Receiver Characterization (Fact Sheet)  

Energy Technology Data Exchange (ETDEWEB)

Fact sheet describing NREL CSP Program capabilities for collector/receiver characterization: determining optical efficiency, measuring heat loss, developing and testing concentrators, concentrating the sun's power, and optically characterizing CSP plants.

2010-08-01

333

49 CFR 229.77 - Current collectors.  

Science.gov (United States)

...77 Current collectors. (a) Pantographs shall be so arranged that they can...engineer's normal position in the cab. Pantographs that automatically rise when released...in the down position. (b) Each pantograph operating on an overhead...

2010-10-01

334

Performance of a solar-thermal collector  

Science.gov (United States)

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

Higa, W. H.

1975-01-01

335

Subsystem design package for solar II collector  

Energy Technology Data Exchange (ETDEWEB)

The necessary information is given to evaluate the design of the Solar II Air Flat Plate Collector, Model SC4X8. The document consists of the Design Data Brochure, Subsystem Performance Specification, and Detailed Design Drawings.

1978-01-01

336

Certification of the concentrating solar collector  

Science.gov (United States)

Report describes procedures and results of extensive testing of concentrating solar collector performed for certification of systems compliance with government performance standards. Test includes operational, electrical, mechanical, and thermal checks, as well as structural integrity.

1980-01-01

337

Solar thermal collector augmented by flat plate booster reflector: Optimum inclination of collector and reflector  

International Nuclear Information System (INIS)

In this report we present a theoretical analysis of a solar thermal collector with a flat plate top reflector. The top reflector extends from the upper edge of the collector, and can be inclined forwards or backwards from vertical according to the seasons. We theoretically predicted the daily solar radiation absorbed on an absorbing plate of the collector throughout the year, which varies considerably with the inclination of both the collector and reflector, and is slightly affected by the ratio of the reflector and collector length. We found the optimum inclination of the collector and reflector for each month at 30oN latitude. An increase in the daily solar radiation absorbed on the absorbing plate over a conventional solar thermal collector would average about 19%, 26% and 33% throughout the year by using the flat plate reflector when the ratio of reflector and collector length is 0.5, 1.0 and 2.0 and both the collector and reflector are adjusted to the proper inclination.

338

Incidence angle modifiers in cylindrical solar collector design. Final report, June 1996--May 1997  

Energy Technology Data Exchange (ETDEWEB)

This thesis presents an analysis of the thermal performance of cylindrical solar collectors. A major contributor to performance is optics, the principle focus of this work. A tool used to compute the incidence angle modifiers (IAM`s) for cylindrical solar collectors is presented. The Monte Carlo Method is employed in a Fortran 90 computer code to compute the hemispheric IAM`s of cylindrical solar collectors. Using concentric cylinders, the tubes are modeled with and without back plane reflectors of varying size. The computed IAM`s are verified both analytically and experimentally. Outdoor experiments on an array of cylindrical tubes with various back planes and two different tube spacings are described. Agreement with TRNSYS runs in daily energy gain is excellent. Over the 38 data sets, taken on different days, a maximum error of 11.2% is observed, with an average error of 3%. Heat loss tests, used to calculate an overall heat loss coefficient for the collector, are also described. A parametric variation study is used to illustrate the effect of varying many of the collector parameters. This study provides insight into the significant design parameters for cylindrical solar collectors. This insight is used to analyze the effect of these design parameters on the annual energy delivered by the collector. In addition, a simple cost analysis illustrates the benefits of varying the design parameters. The use of this new program and a detailed Life Cycle Cost analysis are the tools needed for optimizing the design of a cylindrical solar collector. 27 figs., 9 tabs.

Ryan, J.P.

1997-05-01

339

Comparative Study: Garbage Collector in OODBMS  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper addresses the use of garbage collectors for efficient garbage collection in a large object-oriented database. The OODB is partitioned and grouped independently by using information about inter-partition references. This maintains the information on disk so that it can be recovered after any kind of crash like disk failure. We have discussed the part of garbage collector responsibility for maintaining information about inter-partition references and how they work dur...

Abhay Kumar 1; Jitendra Singh Yadav 2

2014-01-01

340

Foldable Frame Supporting Electromagnetic Radiation Collectors  

DEFF Research Database (Denmark)

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 flexible frame into a stressed configuration. Once released from the stressed configuration the flexible frame restores its initial configuration without any external intervention.

Kristensen, Anders Schmidt VBN,

 
 
 
 
341

Radiant smiles everywhere - before the Chernobyl accident  

International Nuclear Information System (INIS)

The business reports presented by the Federal German electric utilities for 1985 are almost all simply brillant. Electricity consumption has been going up, some of the utilities even can boast about rates kept constant over the year. But before the printed business reports could be presented to the meetings of shareholders, a nasty cloud threw a dark shadow over all the brilliant results. The Chernobyl accident made some of the hymns over the nuclear electricity increases and nuclear power in general sound rather queer. Could we do without this energy source. Substituting nuclear power would yearly require: 28 million t of oil, or 41 million t of hard coal, or 142 million t of browncoal, or 38 thousand million cubic metres of natural gas. Extrapolating current conditions and assuming best achievements, renewable energy sources might be able to meet 6 p.c. of the primary energy demands by the year 2000. (orig./HP)

342

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; ? = 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; ? = 0.43 × ? + 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)

343

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

344

Optimized concentrating/passive tracking solar collector. Final report  

Energy Technology Data Exchange (ETDEWEB)

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

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

1979-01-01

345

A Series of Supramolecular Complexes for Solar Energy Conversion via Water Reduction to Produce Hydrogen: An Excited State Kinetic Analysis of Ru(II,Rh(III,Ru(II Photoinitiated Electron Collectors  

Directory of Open Access Journals (Sweden)

Full Text Available Mixed-metal supramolecular complexes have been designed that photochemically absorb solar light, undergo photoinitiated electron collection and reduce water to produce hydrogen fuel using low energy visible light. This manuscript describes these systems with an analysis of the photophysics of a series of six supramolecular complexes, [{(TL2Ru(dpp}2RhX2](PF65 with TL = bpy, phen or Ph2phen with X = Cl or Br. The process of light conversion to a fuel requires a system to perform a number of complicated steps including the absorption of light, the generation of charge separation on a molecular level, the reduction by one and then two electrons and the interaction with the water substrate to produce hydrogen. The manuscript explores the rate of intramolecular electron transfer, rate of quenching of the supramolecules by the DMA electron donor, rate of reduction of the complex by DMA from the 3MLCT excited state, as well as overall rate of reduction of the complex via visible light excitation. Probing a series of complexes in detail exploring the variation of rates of important reactions as a function of sub-unit modification provides insight into the role of each process in the overall efficiency of water reduction to produce hydrogen. The kinetic analysis shows that the complexes display different rates of excited state reactions that vary with TL and halide. The role of the MLCT excited state is elucidated by this kinetic study which shows that the 3MLCT state and not the 3MMCT is likely that key contributor to the photoreduction of these complexes. The kinetic analysis of the excited state dynamics and reactions of the complexes are important as this class of supramolecules behaves as photoinitiated electron collectors and photocatalysts for the reduction of water to hydrogen.

Shamindri M. Arachchige

2011-12-01

346

Study on the Effect of the Curvature of Solar Collector on Wind Loading Coefficients and Dynamic Response of Solar Collector  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In the current research, the work concentrated on studying the effect of curvature of solar parabolic trough solar collector on wind loading coefficients and dynamic response of solar collector. The response of collector to the aerodynamic loading was estimated numerically and experimentally. The curvature of most public parabolic trough solar collectors was investigated and compared. The dynamic response of solar collector due to wind loading was investigated by using numerical solution of f...

Khalid Hameed Hussein; Aladine Abdulkader Kazem

2013-01-01

347

Low and medium temperature solar thermal collector based in innovative materials and improved heat exchange performance  

International Nuclear Information System (INIS)

Highlights: • We designed, built and tested 2 different prototypes of thermal collector. • We included polymeric materials and suppressed pipes for freeform optimization. • Efficiency of the collector achieved values as high as commercial ones. • We provided a low cost and high volume production product. - Abstract: A low and medium temperature solar thermal collector for economical supply of heat between 40 and 90 °C has been developed. It is based on solar concentrating systems, heat transfer optimization and substitution of metallic materials by plastic ones. The basic concept is the integration of a flat absorber strip inside semicircular reflector channels in contact with heated water without pressurization. This collector is intended to be more efficient and cheaper than what actual commercial collectors usually are so that the access to a clean and renewable energy would be more quickly redeemable and its use more effective during its life cycle, expanding its common application range. The substitution of traditional materials by surface treated Aluminum with TiNOx for the absorber and chromed thermoformed ABS for the reflector simplifies the production and assembly process. The definitive prototype has an aperture area of 0.225 m2. It was tested in Zaragoza (Spain) and the accumulated efficiency was between 41% and 57%, and the instantaneous efficiency reached 98% depending on the weather conditions. As all trials were made in parallel with a commercial collector, in several cases the performance was over the commercial one

348

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)

349

High-performance carbon-based supercapacitors using Al current-collector with conformal carbon coating  

International Nuclear Information System (INIS)

Al current-collector with porous surface is coated with a conformal carbon (C) layer via a chemical vapor deposition process in CH4 at 600 deg. C. X-ray photoelectron spectroscopy analysis indicates that the coating process leads to the replacement of native aluminum oxide with a composite coating consisting of an Al4C3 interfacial layer and a C top layer. Activated C-based supercapacitors employing the resulting C-coated Al current-collectors have exhibited remarkably enhanced high-rate performance, and the enhancement can be attributed to two accounts. Firstly, the current-collector/active-layer interface resistance is reduced due to removal of the insulating oxide layer and improved adhesion of the active-layer on the current-collector. Secondly, the presence of the conducting C layer shortens the effective current conduction distance from the solid-electrolyte interface to the current-collector, leading to reduced charge-transfer resistance within the active-layer. Combining the C-coated Al current-collector with a C fiber active-layer that contains a large mesoporous pore volume (0.4 cm3 g-1) has resulted in high-performance supercapacitors that exhibit, for instance, a cell specific energy of 18 Wh Kg-1 at 25 deg. C or 7 Wh Kg-1 at -10 deg. C under a cell specific power of 25 KW Kg-1.

350

Practical behaviour of vacuum tube and flat-plate collectors concerning domestic hot water preparation and room heating; Das praktische Verhalten von Vakuumroehren- und Flachkollektoren im Hinblick auf Brauchwasserbereitung und Heizungsunterstuetzung  

Energy Technology Data Exchange (ETDEWEB)

The Centre of Excellence for Solar Engineering at Ingolstadt University of Applied Sciences investigates a solar-assisted heating system in a two-family-house. The major targets of this project are the demonstration of solar energy utilisation in redeveloped family-houses as well as its potential of CO{sub 2}-emission reduction. Furthermore, the behaviour of modern vacuum tube and flat-plate collectors regarding hot water preparation and room heating is examined. The building is equipped with flat-plate collectors (6,42 m{sup 2}), vacuum tube collectors (15,6 m{sup 2}), a stratification tank (800 I) and an oil furnace (22 kW). The investigation shows that both collector types are capable of solar room heating systems. In autumn 2004 a considerable solar fraction could be achieved. Both collector types worked very satisfying regarding their energy yield and the temperature levels delivered. Unexpectedly, the flat-plate collectors showed a more favourable performance within this system than the vacuum tube collectors during winter times. This seems to be due to the vacuum tube collectors being frosted comparably long. Apart from that, snow obviously covers the vacuum tube collectors longer than the flat-plate collectors. The snow slips off the flat-plate collectors' glass cover but sticks between the tubes of the vacuum tube collectors. This project is financially supported by the Bavarian State Ministry for Environmental Affairs, Health and Consumer Protection. (orig.)

Trinkl, C.; Zoerner, W.; Alt, C.; Stadler, C. [Kompetenzzentrum Solartechnik an der Fachhochschule Ingolstadt (Germany)

2005-07-01

351

Using solar roofs twice over. Rooftop hybrid collectors supply electricity and heat; Solardaecher doppelt nutzen. Hybrid-Kollektoren auf dem Dach liefern Strom und Waerme  

Energy Technology Data Exchange (ETDEWEB)

Instead of screwing various module and collector types for solar power and solar heat on the roof, an obvious idea would be to use a hybrid collector that can do both and which creates a uniform appearance. In addition to generating photovoltaic electricity, which only utilises 15-20 % of the incident solar radiation, a so-called PVT collector can use the remaining radiation energy for generating heat. Researchers are working on optimising the output and production of these systems. (orig.)

Hirn, Gerhard

2012-11-01

352

Two new designs of parabolic solar collectors  

Directory of Open Access Journals (Sweden)

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.

Karimi Sadaghiyani Omid

2014-01-01

353

Efficiencies of flat plate solar collectors at different flow rates  

DEFF Research Database (Denmark)

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

Chen, Ziqian; Furbo, Simon

2012-01-01

354

Integrated main rail, feed rail, and current collector  

Science.gov (United States)

A separator plate is described for a fuel cell comprising an anode current collector, a cathode current collector and a main plate, the main plate disposed between the anode current collector and the cathode current collector. The anode current collector forms a flattened peripheral wet seal structure and manifold wet seal structure on the anode side of the separator plate and the cathode current collector forms a flattened peripheral wet seal structure and manifold wet seal structure on the cathode side of the separator plate. In this manner, the number of components required to manufacture and assemble a fuel cell stack is reduced. 9 figs.

Petri, R.J.; Meek, J.; Bachta, R.P.; Marianowski, L.G.

1994-11-08

355

CISBAT 2007 - Solar collectors (heat and electricity)  

Energy Technology Data Exchange (ETDEWEB)

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.

NONE

2007-07-01

356

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

International Nuclear Information System (INIS)

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

357

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

358

Designing, Construction and Analysis of Speed Control System of the Fan with PV Feeding Source in an Air Solar Collector  

Directory of Open Access Journals (Sweden)

Full Text Available Solar energy is one of the renewable energy sources which can be received more by designing more accurate systems. In this article a flat solar collector with the area of 2×1m2 and thickness of 0.5mm, made of steel iron in the form of venetian blinds (in order to increase exposure to air has been used. The surface of absorber plate was black and for insulation of the body of the collector glass wool has been used with 5 cm thickness. One of the essential problems of air solar collectors is that the temperature of the exiting air temperature from the collector is variable during the day and their efficiency is low in the last hours of the day and also when the weather suddenly gets cloudy .In this study, to keep constant the exiting air from the collector consistent in the desired limits, a control system is designed and constructed by applying photovoltaic cells, a microcontroller (AVR and temperature sensors (LM35. Three temperature sensors were installed in the exit of the collector .The experiment results showed that by automatic change of the fan's speed in the designed system, the exiting temperature of the collector was obtained in the desired limits which is an outstanding advantage for various applications.

Amir Hematian

2011-12-01

359

Depressed collectors for high-power gyrotrons  

International Nuclear Information System (INIS)

An analytic and numerical study of the feasibility of depressed collectors for gyrotrons for accelerator applications was performed and a specific design for a 10-GHz 30-MW gyroklystron was realized. The conclusion of the study is that depressed collectors are feasible for gyrotrons of interest for accelerator applications (i.e., P ? 100 MW, 10 GHz < line-integral < 35 GHz), and that their use would reduce capital costs for the RF system for a typical large accelerator by roughly 40%. In addition, scaling studies indicate that depressed collector are feasible for fusion-related gyrotron oscillators, such as the 1-MW, 280-GHz devices being developed for use on the Compact Ignition Tokamak (CIT)

360

Comparative Study: Garbage Collector in OODBMS  

Directory of Open Access Journals (Sweden)

Full Text Available This paper addresses the use of garbage collectors for efficient garbage collection in a large object-oriented database. The OODB is partitioned and grouped independently by using information about inter-partition references. This maintains the information on disk so that it can be recovered after any kind of crash like disk failure. We have discussed the part of garbage collector responsibility for maintaining information about inter-partition references and how they work during the transaction call. This paper also contains the comparison between the garbage collector to identify the problem in maintaining the transaction call for large dataset and a proposed solution so that uninterrupted process can be made.

Abhay Kumar 1

2014-06-01

 
 
 
 
361

Destruction of halogenated VOCs using premixed radiant burner  

Energy Technology Data Exchange (ETDEWEB)

The paper describes the destruction of halogenated volatile organic compounds (VOCs) using a premixed radiant burner. Alzeta Corporation has developed a natural-gas-fired thermal oxidizer to provide emission control for industrial exhaust streams where stringent emisson limits of VOCs are required. Measurements, made with assistance of the U.S. EPA at Research Triangle Park, NC, show destruction efficiencies (DEs) between 99.9766 and 99.999% for eight common halogenated compounds. A brief discussion of pertinent regulations and emissions of concern is presented. The EPA test program is presented with results. Three similarly designed commercial thermal oxidizers are described, including emission test results.

Bartz, D.F.; Marshall, B.N.; Bruce, K.; Lombardo, A.; Lee, C.W.

1996-06-01

362

Radiant coolers - Theory, flight histories, design comparisons and future applications  

Science.gov (United States)

Radiant coolers have been developed for application to the cooling of infrared detectors aboard NASA earth observation systems and as part of the Defense Meteorological Satellite Program. The prime design constraints for these coolers are the location of the cooler aboard the satellite and the satellite orbit. Flight data from several coolers indicates that, in general, design temperatures are achieved. However, potential problems relative to the contamination of cold surfaces are also revealed by the data. A comparison among the various cooler designs and flight performances indicates design improvements that can minimize the contamination problem in the future.

Donohoe, M. J.; Sherman, A.; Hickman, D. E.

1975-01-01

363

Radiant science, dark politics: a memoir of the nuclear age  

International Nuclear Information System (INIS)

The reviewer describes Radiant Science, Dark Politics: A Memoir of the Nuclear Age in contrast to a memoir by James R. Killian, Jr., a contemporary of Kamen. Kamen, co-discoverer of carbon-14 and a valued member of the Berkeley Radiation Laboratory, was fired in 1944 and blackballed as a security risk. Rehabilitated by the end of the war, his continued fight against political injustice through the McCarthy era colors the book and, for the reviewer, makes it self-serving. Kamen's later scientific work reflected his desire to work alone rather than in collaboration

364

Qualification test and analysis report: solar collectors  

Energy Technology Data Exchange (ETDEWEB)

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

1978-12-01

365

Lightweight, low-cost solar energy collector  

Science.gov (United States)

A lightweight solar concentrator of the reflecting parabolic or trough type is realized via a thin reflecting film, an inflatable structural housing and tensioned fibers. The reflector element itself is a thin, flexible, specularly-reflecting sheet or film. The film is maintained in the parabolic trough shape by means of a plurality of identical tensioned fibers arranged to be parallel to the longitudinal axis of the parabola. Fiber ends are terminated in two identical spaced anchorplates, each containing a plurality of holes which lie on the desired parabolic contour. In a preferred embodiment, these fibers are arrayed in pairs with one fiber contacting the front side of the reflecting film and the other contacting the back side of the reflecting film. The reflective surface is thereby slidably captured between arrays of fibers which control the shape and position of the reflective film. Gas pressure in the inflatable housing generates fiber tension to achieve a truer parabolic shape.

Hochberg, Eric B. (Inventor); Costen, Michael K. (Inventor)

2006-01-01

366

Domestic oven heated by a concentrating solar collector  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A project to power a domestic oven by solar energy was developed. The focal axis of a cylindrical parabolic reflector usually reaches temperatures of up to 250ºC. A heat transfer fluid carries this heat to the heat exchanger in the oven. Current domestic ovens are generally electric and can reach 250ºC with a power of 2-3 kW. The installation is composed of pumps, valves, thermally insulated pipes, exchanger, etc. These elements transfer the heat collected by the solar collector to the o...

Lloveras Macia?, Joaqui?n

2014-01-01

367

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.

368

Indoor thermal performance evaluation of Daystar solar collector  

Science.gov (United States)

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

Shih, K., Sr.

1977-01-01

369

Theoretical Meteor Radiants for Macroscopic Taurid Complex Objects  

Science.gov (United States)

The calculation of theoretical meteor radiants is discussed for comets and asteroids whose orbits pass within, but at present do not necessarily intersect, that of the Earth, in particular from the perspective of developing a suitable method for application to Taurid Complex orbits. The main question addressed here is how to allow for dynamical evolution between epochs when an orbit isnot Earth-intersecting (as at present in most cases for macroscopic bodies) and those when itis (i.e., when meteors can actually be observed). This should be understood in terms of evolution in the past, such that meteoroids released some time ago have evolved differentially from the putative parents, allowing meteors to be detected now. Theoretical radiants for macroscopic Taurid objects are then presented and compared with observations of the nighttime and daytime Taurid meteor showers. These are found to be broadly similar in form, given the sparsity of some of the data, adding weight to the hypothesis that this sub-jovian complex contains kilometre-plus asteroids. A similar conclusion results for the group of objects in similar orbits to (2212) Hephaistos.

Asher, D. J.; Steel, D. I.

1995-01-01

370

Density function of radiant flux about perimeters of rectangular cross sections of channels in power plants  

International Nuclear Information System (INIS)

This article examines the density function of radiant flux on the sides of rectangular cross sections of channels in power plants filled with gaseous, hot, selectively radiating and absorbing combustion products of organic fueld. Relations are proposed for evaluating the radiant flux density function under these conditions

371

DT results of TFTR`s alpha collector  

Energy Technology Data Exchange (ETDEWEB)

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 {approximately}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.

Herrmann, H.W.; Zweben, S.J.; Darrow, D.S.; Timberlake, J.R. [Princeton Univ., NJ (United States). Princeton Plasma Physics Lab.; Chong, G.P.; Haasz, A.A. [Univ. of Toronto, Downsview, Ontario (Canada). Inst. for Aerospace Studies; Pitcher, C.S. [Max-Planck-Inst. fuer Plasmaphysik, Garching (Germany); Macaulay-Newcombe, R.G. [McMaster Univ., Hamilton, Ontario (Canada). Dept. of Engineering Physics

1996-11-01

372

Thermionic converter performance with oxide collectors  

Science.gov (United States)

Thermionic converters using a variety of metal oxide collector surfaces have been fabricated and tested. Both work function and power output data are presented and evaluated. Oxides of barium, strontium, zinc, tungsten and titanium have been incorporated into a variable spacing converter. Tungsten oxide was found to give the highest converter performance and to furnish oxygen for the emitter at the same time. Oxygenated emitters operate at reduced cesium pressure with an increase in electrode spacing. Electron spectroscopy for chemical analysis (ESCA) performed on several tungsten oxide collectors showed cesium penetration of the oxide layer, possibly forming a cesium tungstate bronze. Titanium oxide showed high performance but did not furnish oxygen for the emitter; strontium oxide, in the form of a sprayed layer, appeared to dissociate in the presence of cesium. Sprayed coatings of barium and zinc oxides produced collector work functions of about 1.3 eV, but had excessive series resistance. Lanthanum hexaboride, in combination with oxygen introduced through a silver tube, and cesium produced a low work function collector and better than average performance.

Lieb, D.; Goodale, D.; Briere, T.; Balestra, C.

1977-01-01

373

A closed parabolic trough solar collector  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this document, we study a design of closed-box parabolic trough concentrated solar collector. By accepting an optical loss of a few percentages due to reflections by the cover, this design offers several advantages over the current open model, in particular a potential of significant cost reduction.

Xiao, Gang

2007-01-01

374

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

Directory of Open Access Journals (Sweden)

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

Safrani

2012-12-01

375

MERCURY CONTROL WITH ADVANCED HYBRID PARTICULATE COLLECTOR  

Energy Technology Data Exchange (ETDEWEB)

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. An additional task was included in this project to evaluate mercury oxidation upstream of a dry scrubber by using mercury oxidants. This project demonstrated at the pilot-scale level a technology that provides a cost-effective technique to control mercury and, at the same time, greatly enhances 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 for improved fine particulate control combined with effective mercury control for a large segment of the U.S. utility industry as well as other industries.

Ye Zhuang; Stanley J. Miller

2005-05-01

376

Basic research on radiant burners. Final report, February 1987-February 1992  

Energy Technology Data Exchange (ETDEWEB)

A computer model was modified and used to predict the operating characteristics of natural gas fired porous surface radiant burners. Performance parameters studied during this contract included radiant flux from the burner surface, burner surface temperature, NOx emissions, and flame attachment and flashback stability limits. Each year, computational work was performed to predict radiant burner performance. Concurrently, experimental work was performed to compare to these computational results. Validation of the code against experimental data allows the code to be used as a design tool in the further development of radiant burner combustion systems. Thermal performance, limits of stable operation, and NOx emissions have been correlated to experimental data in the report. In addition, catalytic radiant burners were fabricated and tested during the first and fourth years of the contract.

Kendall, R.M.; DesJardin, S.T.; Sullivan, J.D.

1992-04-01

377

Basic research on radiant burners. Annual report, February 1987-January 1988  

Energy Technology Data Exchange (ETDEWEB)

During the first year of the project, significant progress was made in flame attachment and radiant-output studies of radiant surface burners. Predictions of surface radiation and flame liftoff were made with a surface-modified flame-chemistry computer model. These predictions agree remarkably well with experimentally measured radiation and flame liftoff for a ceramic fiber burner under a wide range of operating conditions. Experimental data for two other types of radiant burners were also compared with the computer-model predictions. A doubling of radiant output at low excess-air levels with similar flame-liftoff stability limits was demonstrated on a platinum-coated ceramic-fiber burner compared with a conventional ceramic-fiber burner. Flashback will be studied computationally and experimentally in the second year of the project. Radiant output will be the focus of the third year.

Kendall, R.M.; DesJardin, S.T.

1988-04-01

378

Testing and thermal modeling of radiant panels systems as commissioning tool  

International Nuclear Information System (INIS)

This paper presents the results of a study performed to develop a thermal modeling of radiant panels systems to be used in situ, as diagnosis tool in commissioning processes to determine the main operating conditions of the system in cooling or heating mode. The model considers the radiant panels as a finned heat exchanger in dry regime. By using as inputs the ceiling and room dimensions, the radiant ceiling material properties and the measurements of air and water mass flow rates and temperatures, the model is able to calculate the radiant ceiling capacity, ceiling surface average temperature, water exhaust temperature and resultant temperature as a comfort indicator. The modeling proposed considers combined convection, perforation effect and a detailed radiative heat exchange method for radiant ceiling systems. An example of each system considered in this study is shown, illustrating the validation of the model. A sensitive analysis of the model is performed.

379

Thermodynamic limits for efficiency of radiant energy conversion  

International Nuclear Information System (INIS)

Thermodynamic limits determining possible values of equilibrium radiation conversion to work in radiation exchange of a converter with a high-temperature source with low-temperature one and also in the absence of converter heat exchange with medium are considered. In the last case, maximal efficiency is determined by a relation of radiation exchange aperture, but not only by a relation of temperatures of power sources

380

Radiant energy absorption enhancement in optical imaging systems  

Science.gov (United States)

Reimaging system efficiently uses incident light and overcomes previous imaging detector problems. Optical system collects reflected and focal plane transmitted light and redirects it so it again impinges on focal plane in register with original image. Reimaging unabsorbed light increases light absorption and detector use probability.

Brown, R. M.; Gunter, W. D., Jr.

1971-01-01

 
 
 
 
381

Effect of Radiant Energy on Near-Surface Water  

Digital Repository Infrastructure Vision for European Research (DRIVER)

While recent research on interfacial water has focused mainly on the few interfacial layers adjacent to the solid boundary, century-old studies have extensively shown that macroscopic domains of liquids near interfaces acquire features different from the bulk. Interest in these long-range effects has been rekindled by recent observations showing that colloidal and molecular solutes are excluded from extensive regions next to many hydrophilic surfaces [Zheng and Pollack Phys. Rev. E 2003, 68, ...

Chai, Binghua; Yoo, Hyok; Pollack, Gerald H.

2009-01-01

382

Non-destructive component separation using infrared radiant energy  

Science.gov (United States)

A method for separating a first component and a second component from one another at an adhesive bond interface between the first component and second component. Typically the method involves irradiating the first component with infrared radiation from a source that radiates substantially only short wavelengths until the adhesive bond is destabilized, and then separating the first component and the second component from one another. In some embodiments an assembly of components to be debonded is placed inside an enclosure and the assembly is illuminated from an IR source that is external to the enclosure. In some embodiments an assembly of components to be debonded is simultaneously irradiated by a multi-planar array of IR sources. Often the IR radiation is unidirectional. In some embodiments the IR radiation is narrow-band short wavelength infrared radiation.

Simandl, Ronald F. (Knoxville, TN); Russell, Steven W. (Knoxville, TN); Holt, Jerrid S. (Knoxville, TN); Brown, John D. (Harriman, TN)

2011-03-01

383

Camera system with array of radiant energy detectors  

International Nuclear Information System (INIS)

A gamma camera has an array of photodetectors arranged to produce a current pulse in response to a flash light produced by a scintillator in response to an incident gamma ray photon. Said current pulse is passed to an integrator which produces a voltage which rises from an initial reference level, to a peak level, said peak level being representative of the charge in the current pulse. The output of the integrator is reset by a circuit to the initial reference level a predetermined time after the production of the current pulse, thereby enabling each integrator to respond to the next current pulse produced by succeeding gamma ray photons. (author)

384

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

DEFF Research Database (Denmark)

The thermal performances of solar collectors and solar combi systems with different solar fractions are studied under the influence of the Danish Design Reference Year, DRY data file, and measured weather data from a solar radiation measurement station situated at the Technical University of Denmark in Kgs. Lyngby. The data from DRY data file are used for any location in Denmark. The thermal performances of the solar heating systems are calculated by means of validated computer models. The measured yearly solar radiation varies by approximately 23% in the period from 1990 until 2002, and the investigations show that it is not possible to predict the yearly solar radiation on a tilted surface based on the yearly global radiation. The annual thermal performance of solar combi systems cannot with reasonable approximation be fitted to a linear function of the annual total radiation on the solar collector or the annual global radiation. Solar combi systems with high efficient solar collectors are more influenced by weather variations from one year to another than systems with low efficient solar collectors. The annual thermal performance of solar collectors cannot be predicted from the global radiation, but both the annual thermal performance and the annual utilized solar energy can with a reasonable approximation be fitted to a linear function of the yearly solar radiation on the collector for both flat plate and evacuated tubular solar collectors. Also evacuated tubular solar collectors utilize less sunny years with large parts of diffuse radiation relatively better than flat plate collectors.

Andersen, Elsa; Furbo, Simon

2009-01-01

385

Development of a low-temperature, low-cost, black liquid solar collector. Final report, September 12, 1977-October 31, 1978  

Energy Technology Data Exchange (ETDEWEB)

Battelle's Columbus Laboratories (BCL) has developed an efficient, low-cost, low-temperature, nonconcentrating, liquid-heating solar collector suitable for use as a thermal energy source for heat pumps or other heating applications. The collector incorporates a black liquid heat transfer medium permitting solar radiation to be absorbed directly by the liquid. Based on detailed measurements of the spectral absorption properties on many black liquids, and on the results of computer analysis of collector performance, it has been shown that the black liquid collector concept has the potential of significantly improved performance compared with an unglazed (i.e., swimming pool type) black-absorber collector of comparable cost.On the other hand, it has the potential of significant cost savings compared with the single-glazed collector of comparable performance. Experimental data obtained on two black liquid collectors constructed during this project closely match the predicted curves obtained from a theoretical computer analysis. Results of the systems analysis studies have shown that the black liquid collector, when used as a heat source for a solar-assisted heat pump, has comparable performance to that of a single-glazed conventional collector but at considerably lower cost. Another important result is that currently available heat pump systems are not ideally matched or compatible with a solar-assisted system. A solar-assisted system will require design of heat pumps which can take advantage of the higher system coefficient of performance (COP) possible with a heat source at elevated temperatures.

Landstrom, D K; Talbert, S G; Stickford, Jr, G H; Fischer, R D; Hess, R E

1978-10-01

386

Energy detection method and apparatus  

International Nuclear Information System (INIS)

A method is described of detecting neutrinos comprising the steps of irradiating a material with the neutrinos to cause coherent stimulated emission of radiant energy fields in the material in response to the material being irradiated by the neutrinos, and detecting the coherent radiant energy fields

387

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

International Nuclear Information System (INIS)

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

388

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

DEFF Research Database (Denmark)

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

Taherian, H.; Kolaei, Alireza Rezania

2011-01-01

389

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

CERN Document Server

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...

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

2001-01-01

390

Development of solar collector to integration in buildings; Udvikling af solfanger til integrering i bygninger  

Energy Technology Data Exchange (ETDEWEB)

A solar collector has been developed in the project. The development of the collector is based on knowledge from previous projects and the idea of combining existing exterior insulation systems with a solar collector part for renovation purpose. This solar collector especially focuses on the market, which is dedicated to concrete buildings. South heading gable/facade walls in concrete buildings have a potential for utilization of solar energy. With regards to commercial utilization of the results the project has building parts manufacturers and solar collector manufacturers in mind. Besides the housing stock the industry sector is an area where gable solar collectors can be used. To get the right link between the manufactured part and the building, an existing building is referred to in the project. A prefabricated insulation system from Paroc and a liquid heating absorber from Batec have been chosen as the basis of the project. 50 mm wide aluminium profiles from H.S. Hansen have been used, accomplishing a sliding joint to the adjacent building systems. A range of flashing, is available on the market, fits to the 50 mm profile. Based on these choices the concept of utilizing solar energy can be transferred without difficulties to be valid for other exterior insulation systems, absorber types and consumer systems. Technical details concerning profiles and assembling of solar collectors have been analysed in the project and can be seen from the technical drawings. The mounting of the solar collector will be done by crane so that the work can be done fast and efficiently. This is particularly important in narrow streets, as here is no need to establish building sites for a long period. Crane assembling is suitable when the walls have big areas without needs for many cuttings and projections. If there are windows in the gable a vertical assembling of the elements can be the solution as the windows are often placed in a straight line above each other. In the project calculations have been made of stagnation temperatures of solar collector elements and of the performance of a vertically placed collector with coated glass (AR-glass) as cover. There has been made an economic analysis of the system connected in a block of flats where the consumer system is heating of domestic hot water. The project leads to a prototype of a gable solar collector, which can be seen on IBE's outdoor facility areas. The gable solar collector including ribbon panel has an area of 7 m x 3 m and consists of 2 elements where the upper element is mounted with AR-coated glass and the lower one is mounted with ordinary iron free glass. A test for rain tightness has been performed with this gable solar collector and the heat loss coefficient has been measured. (au)

Holck, O.; Svendsen, S.

2000-07-01

391

Parabolic Trough Photovoltaic/Thermal Collectors: Design and Simulation Model  

Directory of Open Access Journals (Sweden)

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

Laura Vanoli

2012-10-01

392

A prototype photovoltaic/thermal system integrated with transpired collector  

Energy Technology Data Exchange (ETDEWEB)

Building-integrated photovoltaic/thermal (BIPV/T) systems may be utilized to produce useful heat while simultaneously generating electricity from the same building envelope surface. A well known highly efficient collector is the open-loop unglazed transpired collector (UTC) which consists of dark porous cladding through which outdoor air is drawn and heated by absorbed solar radiation. Commercially available photovoltaic systems typically produce electricity with efficiencies up to about 18%. Thus, it is beneficial to obtain much of the normally wasted heat from the systems, possibly by combining UTC with photovoltaics. Combination of BIPV/T and UTC systems for building facades is considered in this paper - specifically, the design of a prototype facade-integrated photovoltaic/thermal system with transpired collector (BIPV/T). A full scale prototype is constructed with 70% of UTC area covered with PV modules specially designed to enhance heat recovery and compared to a UTC of the same area under outdoor sunny conditions with low wind. The orientation of the corrugations in the UTC is horizontal and the black-framed modules are attached so as to facilitate flow into the UTC plenum. While the overall combined thermal efficiency of the UTC is higher than that of the BIPV/T system, the value of the generated energy - assuming that electricity is at least four times more valuable than heat - is between 7% and 17% higher. Also, the electricity is always useful while the heat is usually utilized only in the heating season. The BIPV/T concept is applied to a full scale office building demonstration project in Montreal, Canada. The ratio of photovoltaic area coverage of the UTC may be selected based on the fresh air heating needs of the building, the value of the electricity generated and the available building surfaces. (author)

Athienitis, Andreas K.; Bambara, James; O' Neill, Brendan; Faille, Jonathan [Dept. of Building, Civil and Environmental Engineering, Concordia University, 1455 Maisonneuve W., Montreal, Quebec (Canada)

2011-01-15

393

Grid collector: An event catalog with automated file management  

International Nuclear Information System (INIS)

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 events based on tags, such as, ''production date between March 10 and 20, and the number of charged tracks > 100.'' The Grid Collector locates the files containing relevant events, transfers the files across the Grid if necessary, and delivers the events to the analysis code through the familiar iterators. There has been some research efforts to address the file management issues, the Grid Collector is unique in that it addresses the event access issue together with the file management issues. This makes it more useful to a large variety of users

394

Grid collector: An event catalog with automated file management  

Energy Technology Data Exchange (ETDEWEB)

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 events based on tags, such as, ''production date between March 10 and 20, and the number of charged tracks > 100.'' The Grid Collector locates the files containing relevant events, transfers the files across the Grid if necessary, and delivers the events to the analysis code through the familiar iterators. There has been some research efforts to address the file management issues, the Grid Collector is unique in that it addresses the event access issue together with the file management issues. This makes it more useful to a large variety of users.

Wu, Kesheng; Zhang, Wei-Ming; Sim, Alexander; Gu, Junmin; Shoshani, Arie

2003-10-17

395

Modeling and experimental validation of the solar loop for absorption solar cooling system using double-glazed collectors  

International Nuclear Information System (INIS)

Solar cooling applied to buildings is without a doubt an interesting alternative for reducing energy consumption in traditional mechanical steam compression air conditioning systems. The study of these systems should have a closely purely fundamental approach including the development of numerical models in order to predict the overall installation performance. The final objective is to estimate cooling capacity, power consumption, and overall installation performance with relation to outside factors (solar irradiation, outside temperature...). The first stage in this work consists of estimating the primary energy produced by the solar collector field. The estimation of this primary energy is crucial to ensure the evaluation of the cooling capacity and therefore the cooling distribution and thermal comfort in the building. Indeed, the absorption chiller performance is directly related to its heat source. This study presents dynamic models for double glazing solar collectors and compares the results of the simulation with experimental results taken from our test bench (two collectors). In the second part, we present an extensive collector field model (36 collectors) from our solar cooling installation at The University Institute of Technology in St Pierre, Reunion Island as well as our stratified tank storage model. A comparison of the simulation results with real scale solar experimental data taken from our installation enables validation of the double glazing solar cs validation of the double glazing solar collector and stratified tank dynamic models.

396

Theoretical study on a solar collector loop during stagnation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A mathematical model simulating the stagnation behavior of a pressurized solar collector loop with solar collectors with a good emptying behavior is developed. Based on the pre-pressure of the expansion vessel, the system filling pressure of the solar collector loop and the design of the solar 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 c...

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

2010-01-01

397

Effect of beam limiting aperture and collector potential on multi-element focused ion beams  

Energy Technology Data Exchange (ETDEWEB)

A compact microwave driven plasma based multi-element focused ion beam system has been developed. In the present work, the effect of reduced beam limiter (BL) aperture on the focused ion beam parameters, such as current and spot size, and a method of controlling beam energy independently by introducing a biased collector at focal point (FP) are investigated. It is found that the location of FP does not change due to the reduction of BL aperture. The location of FP and beam size are found to be weakly dependent on the collector potential in the range from -8 kV to -18 kV.

Paul, Samit; Chowdhury, Abhishek; Bhattacharjee, Sudeep [Department of Physics, Indian Institute of Technology, Kanpur, Uttar Pradesh (India)

2012-02-15

398

Experimental and theoretical development of a thermal design tool for radiant domestic stoves. Paper no. IGEC-1-003  

International Nuclear Information System (INIS)

A steady-state space radiant heat model and a stove combustion model are developed to simulate the heat exchanges between various surfaces in the room and the stove and stack surfaces, assuming stiochiometric combustion inside the stove and the exhaust gases flow out through the stack by natural convection. The space heat model calculates the fuel consumption, the stove, stack temperatures, and the mass flow rate of exhaust gases, and provides an opportunity to study energy efficiency of stove, while satisfying the constraints of thermal comfort. Fanger (1982) model and a radiation exchange model between various surfaces of the space, the thermal building energy balance, and stove combustion process is applied to determine the mean radiant temperature (MRT) and the extent of thermal comfort as determined by predicted mean vote (PMV). The overall model is validated by performing experiments in a room placed inside controlled outdoor environment. The room is heated using a common domestic stove for rural areas of Lebanon. The measured MRT, the average room temperature, the wall surfaces temperatures agreed within ±7% of values predicted by the numerical model. A parametric study using the developed models reveals that the values of MRT and PMV depend strongly on the position of the radiant stove heater and stack with respect to the cold window and the occupant location. It is shown that it is possible to save up to 15% in fuel consumption of the stove by changing the sonsumption of the stove by changing the stove position in the room with respect to the window and to the person, while maintaining the same level of comfort. (author)

399

Development of solar air collectors for drying applications  

International Nuclear Information System (INIS)

In the present work, an experimental study of three types of solar air collectors, namely flat plate, finned and v-corrugated, has been performed towards achieving an efficient design of air collector suitable for a solar dryer. A series of experiments were conducted, based on the ASHRAE standard, under Singapore climatic conditions. The performance of all three collectors is examined over a wide range of operating and design conditions. The v-corrugated collector is found to be the most efficient collector and the flat plate collector the least efficient. The collectors are also studied in double pass mode to investigate the extent of improvement in efficiency that can be achieved without increasing the collector size or cost. Double pass operation of the collector leads to further improvement of the efficiency compared to the single pass of operation. The improvement in efficiency for the double pass mode is most significant in the flat plate collector and least in the v-groove collector

400

Integrated Design of Undepressed Collector for Low Power Gyrotron  

Science.gov (United States)

A 42 GHz, 200 kW continuous wave (CW) gyrotron, operating at TE03 mode is under development for the electron cyclotron resonance plasma heating of the Indian TOKAMAK system. The gyrotron is made up of an undepressed collector. The undepressed collector is simple to design and cost effective. In this paper, a detailed design study of the undepressed collector for the 42 GHz gyrotron is presented. The EGUN code is used to analyze the spent electron beam trajectory for the maximum spread to reduce the power loading on the collector surface. To achieve wall loading ?1 kW/cm2, a collector with a length of 800 mm and a radius of 42.5 mm is designed. The design also includes the three magnet systems around the collector for maximum and uniform beam spread. The thermal and the structural analyses are done using the ANSYS code to optimize the collector structure and dimensions with tolerance.

Kumar, Anil; Goswami, Uttam K.; Poonia, Sunita; Singh, Udaybir; Kumar, Nitin; Alaria, M. K.; Bera, A.; Khatun, Hasina; Sinha, A. K.

2011-06-01

 
 
 
 
401

Hot-air flat-plate solar collector-design package  

Science.gov (United States)

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

1979-01-01

402

Entangled States and Super-radiant Phase Transition  

CERN Document Server

The Dicke spin-boson model is composed by a single bosonic mode and an ensemble of $N$ identical two-level atoms. Assuming thermal equilibrium with a reservoir at temperature $\\beta^{-1}$, we consider the situation where the coupling between the bosonic mode and the atoms generates resonant and non-resonant processes. The thermodynamic of the model is investigated. Next we introduce dipole-dipole interaction between the atoms. We investigate the transition from fluorescent to super-radiant phase and the quantum phase transition in a situation where the dipole-dipole interaction between the atoms generates entangled states in the atomic system. We proved that, the critical behavior is not modified by the introduction of the dipole-dipole interaction.

Alcalde, M Aparicio; Svaiter, N F; Bezerra, V B

2009-01-01

403

Destruction of halogenated VOCs using premixed radiant burner  

Energy Technology Data Exchange (ETDEWEB)

Alzeta Corporation has developed a natural-gas-fired thermal oxidizer to provide emission control for industrial exhaust streams where stringent emission limits of volatile organic compounds (VOCs) are required. Measurements made with assistance from the US Environmental Protection Agency (EPA) at Research Triangle Park, North Carolina, show destruction efficiencies (DEs) between 99.9766 and 99.9999 percent for eight common halogenated compounds. This thermal oxidizer technology utilizes an inward-fired premixed radiant burner that operates at high levels of excess air (typically 80 to 100 percent) to achieve nitrogen oxide (NO{sub x}) and carbon monoxide (CO) emissions below 10 ppm{sub v}, corrected to 3 percent oxygen (O{sub 2}). A brief discussion of pertinent regulations and emissions of concern is presented. The EPA test program is presented with results. A description of three similarly designed commercial thermal oxidizers is presented including emission test results. 12 refs., 5 figs., 7 tabs.

Bartz, D.F.; Marshall, B.N. [Alzeta Corp., Santa Clara, CA (United States); Bruce, K. [Acurex Environmental Corp., Research Triangle Park, NC (United States)] [and others

1996-12-31

404

BigHorn Home Improvement Center Energy Performance  

Energy Technology Data Exchange (ETDEWEB)

The BigHorn Development Project, located in Silverthorne, Colorado, is one of the nation's first commercial building projects to integrate extensive high-performance design into a retail space. The BigHorn Home Improvement Center, completed in the spring of 2000, is a 42,366-ft2 (3,936 m2) hardware store, warehouse, and lumberyard. The authors were brought in at the design stage of the project to provide research-level guidance to apply an integrated design process and perform a postoccupancy evaluation. An aggressive energy design goal of 60% energy cost saving was set early in the process, which focused the efforts of the design team and provided a goal for measuring the success of the project. The extensive use of natural light, combined with energy-efficient electrical lighting design, provides good illumination and excellent energy savings. The reduced lighting loads, management of solar gains, and cool climate allow natural ventilation to meet the cooling loads. A hydronic radiant floor system, gas-fired radiant heaters, and a transpired solar collector deliver heat. An 8.9-kW roof-integrated photovoltaic (PV) system offsets a portion of the electricity. After construction, the authors installed monitoring equipment to collect energy performance data and analyzed the building's energy performance for two and one-half years. The authors also helped program the building controls and provided recommendations for improving operating efficiency. The building shows an estimated 53% energy cost saving and a 54% source energy saving. These savings were determined with whole-building energy simulations that were calibrated with measured data. This paper discusses lessons learned related to the design process, the daylighting performance, the PV system, and the heating, ventilating, and air-conditioning system.

Deru, M.; Pless, S. D.; Torcellini, P. A.

2006-01-01

405

Evaluation of Test Method for Solar Collector Efficiency  

DEFF Research Database (Denmark)

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. 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 on these efficiencies, an efficiency equation is determined by regression analysis. In the test method, there are no requirements on the ambient air temperature and the sky temperature. The paper will present an evaluation of the test method for a 12.5 m² flat plate solar collector panel from Arcon Solvarme A/S. The solar collector panel investigated has 16 parallel connected horizontal absorber fins. CFD (Computational Fluid Dynamics) simulations, calculations with a solar collector simulation program SOLEFF (Rasmussen and Svendsen, 1996) and thermal experiments are carried out in the investigation. The investigations elucidate: • How the mean solar collector fluid temperature Tm is underestimated by the approximated equation in the test standard and how the collector efficiency equation is influenced by the underestimation of Tm. The dependence of the volume flow rate is shown; • How the use of the approximated specific heat of the solar collector fluid is influencing the collector efficiency expression; • How the temperature levels used is influencing the collector efficiency expression; • How the measured collector efficiency is influenced by the weather conditions such as the ambient air temperature and the sky temperature. Based on the investigations, recommendations for change of the test methods and test conditions are considered. The investigations are carried out within the NEGST (New Generation of Solar Thermal Systems) project financed by EU.

Fan, Jianhua; Shah, Louise Jivan

406

Low cost thermal solar collector  

International Nuclear Information System (INIS)

Solar energy is a good alternative in the economy of the electric energy mainly for the water heating. However, the solar heaters used demand a high initial investment, becoming the warm water from solar energy inaccessible to a large part of the society. Thus, a low cost solar heater was developed, constructed and tested in the chemical engineering department of West Parana State University-Unioeste. This equipment consists of 300 cans, divided in 30 columns of 10 cans each, all painted in black to enhance the obsorption of the solar radiation. The columns are connected to a pipe of pvc of 8 liters with 0.085m of external diameter. The equipment is capable to heat 120 liters of water in temperatures around 60 degree centigrade. The heater is insolated in its inferior part with cardboard and aluminum, covered with a transparent plastic in its superior. The system still counts with a insulated thermal reservoir, which can conserve the water in temperatures adjusted for the night non-solar days domestic use. The advantage of the constructed is it low cost material. The results are given an graphical tabular from showing acceptable efficiencies.(Autho

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