WorldWideScience

Sample records for model solar hot

  1. Analysis, Modeling and Optimum Design of Solar Domestic Hot Water Systems

    DEFF Research Database (Denmark)

    Qin, Lin

    1999-01-01

    This study focus on the analysis, modeling and simulation of solar domestic hot water(DHW) systems. Problems related to the system operation such as input weather data and hot water load conditions are also investigated.In order to investigate the heat loss as part of the total heat load, dynamic...... model of distribution network is developed and simulations are carried out for typical designed circulation type of distribution networks. For dynamic simulation of thermosyphon and drain-back solar DHW systems, thermosyphon loop model and drain-back tank model are put forward. Based on the simulations...

  2. Solar 'hot spots' are still hot

    Science.gov (United States)

    Bai, Taeil

    1990-01-01

    Longitude distributions of solar flares are not random but show evidence for active zones (or hot spots) where flares are concentrated. According to a previous study, two hot spots in the northern hemisphere, which rotate with a synodic period of about 26.72 days, produced the majority of major flares, during solar cycles 20 and 21. The more prominent of these two hot spots is found to be still active during the rising part of cycle 22, producing the majority of northern hemisphere major flares. The synodic rotation period of this hot spot is 26.727 + or - 0.007 days. There is also evidence for hot spots in the southern hemisphere. Two hot spots separated by 180 deg are found to rotate with a period of 29.407 days, with one of them having persisted in the same locations during cycles 19-22 and the other, during cycles 20-22.

  3. Solar hot spots are still hot

    International Nuclear Information System (INIS)

    Bai, T.

    1990-01-01

    Longitude distributions of solar flares are not random but show evidence for active zones (or hot spots) where flares are concentrated. According to a previous study, two hot spots in the northern hemisphere, which rotate with a synodic period of about 26.72 days, produced the majority of major flares, during solar cycles 20 and 21. The more prominent of these two hot spots is found to be still active during the rising part of cycle 22, producing the majority of northern hemisphere major flares. The synodic rotation period of this hot spot is 26.727 + or - 0.007 days. There is also evidence for hot spots in the southern hemisphere. Two hot spots separated by 180 deg are found to rotate with a period of 29.407 days, with one of them having persisted in the same locations during cycles 19-22 and the other, during cycles 20-22. 14 refs

  4. Analysis, modeling and optimum design of solar domestic hot water systems

    Energy Technology Data Exchange (ETDEWEB)

    Lin Qin

    1998-12-31

    The object of this study was dynamic modeling, simulation and optimum design of solar DHW (domestic hot water) systems, with respect to different whether conditions, and accurate dynamic behaviour of the heat load. Special attention was paid to systems with thermosyphon and drain-back design. The solar radiation in Beijing (China) and in Denmark are analyzed both by theoretical calculations and the analysis of long-term measurements. Based on the weather data from the Beijing Meteorological Station during the period of 1981-1993, a Beijing Test Reference Year has been formulated by means of statistical analysis. A brief introduction about the Danish Test Reference Year and the Design Reference Year is also presented. In order to investigate the heat loss as a part of the total heat load, dynamic models for distribution networks have been developed, and simulations have been carried out for typically designed distribution networks of the circulation type. The influence of operation parameters such as the tank outlet temperature, the hot-water load and the load pattern, on the heat loss from the distribution networks in presented. It was found that the tank outlet temperature has a significant influence on the heat loss from a circulation type of distribution network, while the hot-water load and the load pattern have no obvious effect. Dynamic models of drain-back tanks, both as a separated tank and combined with a mantle tank, have been developed and presented. Models of the other basic components commonly used in solar DHW systems, such as flat-plate collectors, connection pipes, storage tanks with a heat exchanger spiral, and controllers, are also described. (LN) 66 refs.

  5. Simulation programs for ph.D. study of analysis, modeling and optimum design of solar domestic hot water systems

    Energy Technology Data Exchange (ETDEWEB)

    Lin Qin

    1998-12-31

    The design of solar domestic hot water (DHW) systems is a complex process, due to characteristics inherent in the solar heating technology. Recently, computer simulation has become a widely used technique to improve the understanding of the thermal processes in such systems. One of the main objects of the Ph.D. study of `Analysis, Modelling and optimum Design of Solar Domestic Hot Water Systems` is to develop and verify programs for carrying out the simulation and evaluation of the dynamic performance of solar DHW systems. During this study, simulation programs for hot water distribution networks and for certain types of solar DHW systems were developed. (au)

  6. Solar Hot Water Heater

    Science.gov (United States)

    1978-01-01

    The solar panels pictured below, mounted on a Moscow, Idaho home, are part of a domestic hot water heating system capable of providing up to 100 percent of home or small business hot water needs. Produced by Lennox Industries Inc., Marshalltown, Iowa, the panels are commercial versions of a collector co-developed by NASA. In an effort to conserve energy, NASA has installed solar collectors at a number of its own facilities and is conducting research to develop the most efficient systems. Lewis Research Center teamed with Honeywell Inc., Minneapolis, Minnesota to develop the flat plate collector shown. Key to the collector's efficiency is black chrome coating on the plate developed for use on spacecraft solar cells, the coating prevents sun heat from "reradiating," or escaping outward. The design proved the most effective heat absorber among 23 different types of collectors evaluated in a Lewis test program. The Lennox solar domestic hot water heating system has three main components: the array of collectors, a "solar module" (blue unit pictured) and a conventional water heater. A fluid-ethylene glycol and water-is circulated through the collectors to absorb solar heat. The fluid is then piped to a double-walled jacket around a water tank within the solar module.

  7. Solar action: solar hot water in The Netherlands

    International Nuclear Information System (INIS)

    Van de Water, Adrie

    2001-01-01

    This paper focuses on the use of solar hot water systems in the Netherlands, and reports on the Dutch Solar Domestic Hot Water System agreement signed in 1999 and set up to enhance the development of the market for solar domestic hot water (SDHW) systems and their application as a sustainable energy source. The Dutch Thermal Solar Energy Programme's objectives and goals, the subsidy schemes for thermal solar energy administered by Senter - an agency of the Ministry of Economic Affairs (MEA), and the project-based and individual approaches to boosting the sales of SDHW systems are examined. Large system sales, the targeting of consumers via a national campaign, and national publicity using the slogan 'Sustainable energy. Goes without saying' commissioned by the MEA are discussed along with the support shown by the Dutch power distribution companies for SDHW systems, marketing aspects, and the outlook for sales of SDHW systems

  8. Simulation Programs for Ph.D. Study of Analysis, Modeling and Optimum Design of Solar Domestic Hot Water Systems

    DEFF Research Database (Denmark)

    Qin, Lin

    1999-01-01

    The design of solar domestic hot water system is a complex process, due to characteristics inherent in solar heating technology. Recently, computer simulation has become a widely used technique to improve the understanding of the thermal processes in such systems. This report presents the detaile...... programs or units that were developed in the Ph.D study of " Analysis, Modeling and Optimum Design of Solar Domestic Hot Water Systems"....

  9. Solar Technician Program Blows Hot

    Science.gov (United States)

    Ziegler, Peg Moran

    1977-01-01

    A training program for solar heating technicians was initiated at Sonoma State College's School of Environmental Studies for CETA applicants. Among the projects designed and built were a solar alternative energy center, a solar hot water system, and a solar greenhouse. (MF)

  10. Basics of Solar Heating & Hot Water Systems.

    Science.gov (United States)

    American Inst. of Architects, Washington, DC.

    In presenting the basics of solar heating and hot water systems, this publication is organized from the general to the specific. It begins by presenting functional and operational descriptions of solar heating and domestic hot water systems, outlining the basic concepts and terminology. This is followed by a description of solar energy utilization…

  11. OUT Success Stories: Solar Hot Water Technology

    International Nuclear Information System (INIS)

    Clyne, R.

    2000-01-01

    Solar hot water technology was made great strides in the past two decades. Every home, commercial building, and industrial facility requires hot water. DOE has helped to develop reliable and durable solar hot water systems. For industrial applications, the growth potential lies in large-scale systems, using flat-plate and trough-type collectors. Flat-plate collectors are commonly used in residential hot water systems and can be integrated into the architectural design of the building

  12. OUT Success Stories: Solar Hot Water Technology

    Science.gov (United States)

    Clyne, R.

    2000-08-01

    Solar hot water technology was made great strides in the past two decades. Every home, commercial building, and industrial facility requires hot water. DOE has helped to develop reliable and durable solar hot water systems. For industrial applications, the growth potential lies in large-scale systems, using flat-plate and trough-type collectors. Flat-plate collectors are commonly used in residential hot water systems and can be integrated into the architectural design of the building.

  13. BC SEA Solar Hot Water Acceleration project

    Energy Technology Data Exchange (ETDEWEB)

    Harris, N.C. [BC Sustainable Energy Association, Victoria, BC (Canada)

    2005-07-01

    Although solar hot water heating is an environmentally responsible technology that reduces fossil fuel consumption and helps mitigate global climate change, there are many barriers to its widespread use. Each year, domestic water heating contributes nearly 6 million tonnes of carbon dioxide towards Canada's greenhouse gas emissions. The installation of solar water heaters can eliminate up to 2 tonnes of carbon dioxide emissions per household. The BC SEA Solar Hot Water Acceleration project was launched in an effort to demonstrate that the technology has the potential to be widely used in homes and businesses across British Columbia. One of the main barriers to the widespread use of solar hot water heating is the initial cost of the system. Lack of public awareness and understanding of the technology are other barriers. However, other jurisdictions around the world have demonstrated that the use of renewables are the product of conscious policy decisions, including low-cost financing and other subsidies that have created demand for these technologies. To this end, the BC SEA Solar Hot Water Acceleration project will test the potential for the rapid acceleration of solar water heating in pilot communities where barriers are removed. The objective of the project is to install 100 solar water systems in homes and 25 in businesses and institutions in communities in British Columbia by July 2007. The project will explore the financial barriers to the installation of solar hot water systems and produce an action plan to reduce these barriers. In addition to leading by example, the project will help the solar energy marketplace, mitigate climate change and improve energy efficiency.

  14. Analytical modeling of the temporal evolution of hot spot temperatures in silicon solar cells

    Science.gov (United States)

    Wasmer, Sven; Rajsrima, Narong; Geisemeyer, Ino; Fertig, Fabian; Greulich, Johannes Michael; Rein, Stefan

    2018-03-01

    We present an approach to predict the equilibrium temperature of hot spots in crystalline silicon solar cells based on the analysis of their temporal evolution right after turning on a reverse bias. For this end, we derive an analytical expression for the time-dependent heat diffusion of a breakdown channel that is assumed to be cylindrical. We validate this by means of thermography imaging of hot spots right after turning on a reverse bias. The expression allows to be used to extract hot spot powers and radii from short-term measurements, targeting application in inline solar cell characterization. The extracted hot spot powers are validated at the hands of long-term dark lock-in thermography imaging. Using a look-up table of expected equilibrium temperatures determined by numerical and analytical simulations, we utilize the determined hot spot properties to predict the equilibrium temperatures of about 100 industrial aluminum back-surface field solar cells and achieve a high correlation coefficient of 0.86 and a mean absolute error of only 3.3 K.

  15. Solar wind flows associated with hot heavy ions

    International Nuclear Information System (INIS)

    Fenimore, E.E.

    1980-05-01

    Solar wind heavy ion spectra measured with the Vela instrumentation have been studied with the goal of determining the solar origins of various solar wind structures which contain anomalously high ionization states. Since the ionization states freeze-in close to the sun they are good indicators of the plasma conditions in the low and intermediate corona. Heavy ion spectra from three different periods throughout the solar cycle have been analyzed. These data are consistent with freezing-in temperatures ranging from approx. 1.5 x 10 6 K to higher than 9 x 10 6 . The spectra indicating hot coronal conditions occur in roughly 1/7 of all measurements and almost exclusively in postshock flows (PSFs), nonshock related helium abundance enhancements (HAEs), or noncompressive density enhancements (NCDEs). The PSFs and HAEs are both probably interplanetary manifestations of solar flares. The observation of several flare-related HAEs which were not preceded by an interplanetary shock suggests that the flare-heated plasma can evolve into the solar wind without producing a noticeable shock at 1 AU. The NCDEs with hot heavy ions differ from the PSF-HAEs in several ways implying that they evolve from events or places with lower temperatures and less energy than those associated with the flares, but with higher temperatures and densities than the quiet corona. Active regions, coronal mass ejections, and equatorial streamers are possible sources for the NCDEs with spectra indicating hot coronal conditions. These events owe their enhanced densities to coronal processes as opposed to interplanetary dynamical processes. Models of the solar wind expansion demonstrate how some NCDEs can have extreme, nonequilibrium ionization distributions

  16. Solar Energy for Space Heating & Hot Water.

    Science.gov (United States)

    Energy Research and Development Administration, Washington, DC. Div. of Solar Energy.

    This pamphlet reviews the direct transfer of solar energy into heat, particularly for the purpose of providing space and hot water heating needs. Owners of buildings and homes are provided with a basic understanding of solar heating and hot water systems: what they are, how they perform, the energy savings possible, and the cost factors involved.…

  17. Reversible electron–hole separation in a hot carrier solar cell

    International Nuclear Information System (INIS)

    Limpert, S; Bremner, S; Linke, H

    2015-01-01

    Hot-carrier solar cells are envisioned to utilize energy filtering to extract power from photogenerated electron–hole pairs before they thermalize with the lattice, and thus potentially offer higher power conversion efficiency compared to conventional, single absorber solar cells. The efficiency of hot-carrier solar cells can be expected to strongly depend on the details of the energy filtering process, a relationship which to date has not been satisfactorily explored. Here, we establish the conditions under which electron–hole separation in hot-carrier solar cells can occur reversibly, that is, at maximum energy conversion efficiency. We thus focus our analysis on the internal operation of the hot-carrier solar cell itself, and in this work do not consider the photon-mediated coupling to the Sun. After deriving an expression for the voltage of a hot-carrier solar cell valid under conditions of both reversible and irreversible electrical operation, we identify separate contributions to the voltage from the thermoelectric effect and the photovoltaic effect. We find that, under specific conditions, the energy conversion efficiency of a hot-carrier solar cell can exceed the Carnot limit set by the intra-device temperature gradient alone, due to the additional contribution of the quasi-Fermi level splitting in the absorber. We also establish that the open-circuit voltage of a hot-carrier solar cell is not limited by the band gap of the absorber, due to the additional thermoelectric contribution to the voltage. Additionally, we find that a hot-carrier solar cell can be operated in reverse as a thermally driven solid-state light emitter. Our results help explore the fundamental limitations of hot-carrier solar cells, and provide a first step towards providing experimentalists with a guide to the optimal configuration of devices. (paper)

  18. Residential solar hot water

    Energy Technology Data Exchange (ETDEWEB)

    1982-06-01

    This report examines the feasibility of using solar energy to preheat domestic water coming from the city supply at a temperature of approximately 4{degree}C. Four solar collectors totalling 7 m{sup 2} were installed on a support structure facing south at an angle of 60{degree} from the horizontal. The system worked most efficiently in the spring and early summer when the combination of long hours of sunshine, clean air and clear skies allowed for maximum availability of solar radiation. Performance dropped in late summer and fall mainly due to cloudier weather conditions. The average temperature in the storage tank over the 10 months of operation was 42{degree}C, ranging from a high of 83{degree}C in July to a low of 6{degree}C in November. The system provided a total of 7.1 GJ, which is approximately one-third the annual requirement for domestic hot water heating. At the present time domestic use of solar energy to heat water does not appear to be economically viable. High capital costs are the main problem. As a solar system with present day technology can only be expected to meet half to two-thirds of the hot water energy demand the savings are not sufficient for the system to pay for itself within a few years. 5 figs.

  19. Solar heating and hot water system installed at office building, One Solar Place, Dallas, Texas

    Science.gov (United States)

    1980-01-01

    A solar heating on cooling system is described which is designed to provide 87 percent of the space heating needs, 100 percent of the potable hot water needs and is sized for future absorption cooling. The collection subsystem consists of 28 solargenics, series 76, flat plate collectors with a total area of 1,596 square feet. The solar loop circulates an ethylene glyco water solution through the collectors into a hot water system exchanger. The water storage subsystem consists of a heat exchanger, two 2,300 gallon concrete hot water storage tanks with built in heat exchangers and a back-up electric boiler. The domestic hot water subsystem sends hot water to the 10,200 square feet floor area office building hot water water fixtures. The building cold water system provides make up to the solar loop, the heating loop, and the hot water concrete storage tanks. The design, construction, cost analysis, operation and maintenance of the solar system are described.

  20. Solar heating and hot water system installed at office building, One Solar Place, Dallas, Texas. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1980-06-01

    This document is the Final Report of the Solar Energy System Installed at the First Solar Heated Office Building, One Solar Place, Dallas, Texas. The Solar System was designed to provide 87 percent of the space heating needs, 100 percent of the potable hot water needs and is sized for future absorption cooling. The collection subsystem consists of 28 Solargenics, series 76, flat plate collectors with a total area of 1596 square feet. The solar loop circulates an ethylene glycol-water solution through the collectors into a hot water system heat exchanger. The hot water storage subsystem consists of a heat exchanger, two 2300 gallon concrete hot water storage tanks with built in heat exchangers and a back-up electric boiler. The domestic hot water subsystem sends hot water to the 10,200 square feet floor area office building hot water fixtures. The building cold water system provides make-up to the solar loop, the heating loop, and the hot water concrete storage tanks. The design, construction, cost analysis, operation and maintenance of the solar system are described. The system became operational July 11, 1979.

  1. Retrofitting Conventional Electric Domestic Hot Water Heaters to Solar Water Heating Systems in Single-Family Houses—Model Validation and Optimization

    Directory of Open Access Journals (Sweden)

    Luis R. Bernardo

    2013-02-01

    Full Text Available System cost reductions and development of standardised plug-and-function systems are some of the most important goals for solar heating technology development. Retrofitting hot water boilers in single-family houses when installing solar collectors has the potential to significantly reduce both material and installation costs. In this study, the TRNSYS simulation models of the retrofitting solar thermal system were validated against measurements. Results show that the validated models are in good agreement with measurements. On an annual basis a deviation of 2.5% out of 1099 kWh was obtained between the auxiliary energy from results and from the simulation model for a complete system. Using the validated model a system optimization was carried out with respect to control strategies for auxiliary heating, heat losses and volume of auxiliary storage. A sensitivity analysis was carried out regarding different volumes of retrofitted hot water boiler, DHW profiles and climates. It was estimated that, with adequate improvements, extended annual solar fractions of 60%, 78% and 81% can be achieved for Lund (Sweden, Lisbon (Portugal and Lusaka (Zambia, respectively. The correspondent collector area was 6, 4 and 3 m2, respectively. The studied retrofitted system achieves a comparable performance with conventional solar thermal systems with the potential to reduce the investment cost.

  2. Economics of residential solar hot water heating systems in Malaysia

    International Nuclear Information System (INIS)

    Abdulmula, Ahmed Mohamed Omer; Sopian, Kamaruzzaman; Haj Othman, Mohd Yosof

    2006-01-01

    Malaysia has favorable climatic conditions for the development of solar energy due to the abundant sunshine and is considered good for harnessing energy from the sun. This is because solar hot water can represent the large energy consumer in Malaysian households but, because of the high initial cost of Solar Water Heating Systems (SWHSs) and easily to install and relatively inexpensive to purchase electric water heaters, many Malyaysian families are still using Electric Water Heaters to hot their water needs. This paper is presented the comparing of techno-economic feasibility of some models of SWHS from Malaysian's market with the Electric Water Heaters )EWH) by study the annual cost of operation for both systems. The result shows that the annual cost of the electrical water heater becomes greater than than the annual cost of the SWHS for all models in long-team run so it is advantageous for the family to use the solar water heater, at least after 4 years. In addition with installation SWHS the families can get long-term economical benefits, environment friendly and also can doing its part to reduce this country's dependence on foreign oil that is price increase day after day.(Author)

  3. Numerical Simulation of a Solar Domestic Hot Water System

    International Nuclear Information System (INIS)

    Mongibello, L; Graditi, G; Bianco, N; Di Somma, M; Naso, V

    2014-01-01

    An innovative transient numerical model is presented for the simulation of a solar Domestic Hot Water (DHW) system. The solar collectors have been simulated by using a zerodimensional analytical model. The temperature distributions in the heat transfer fluid and in the water inside the tank have been evaluated by one-dimensional models. The reversion elimination algorithm has been used to include the effects of natural convection among the water layers at different heights in the tank on the thermal stratification. A finite difference implicit scheme has been implemented to solve the energy conservation equation in the coil heat exchanger, and the energy conservation equation in the tank has been solved by using the finite difference Euler implicit scheme. Energy conservation equations for the solar DHW components models have been coupled by means of a home-made implicit algorithm. Results of the simulation performed using as input data the experimental values of the ambient temperature and the solar irradiance in a summer day are presented and discussed

  4. Numerical Simulation of a Solar Domestic Hot Water System

    Science.gov (United States)

    Mongibello, L.; Bianco, N.; Di Somma, M.; Graditi, G.; Naso, V.

    2014-11-01

    An innovative transient numerical model is presented for the simulation of a solar Domestic Hot Water (DHW) system. The solar collectors have been simulated by using a zerodimensional analytical model. The temperature distributions in the heat transfer fluid and in the water inside the tank have been evaluated by one-dimensional models. The reversion elimination algorithm has been used to include the effects of natural convection among the water layers at different heights in the tank on the thermal stratification. A finite difference implicit scheme has been implemented to solve the energy conservation equation in the coil heat exchanger, and the energy conservation equation in the tank has been solved by using the finite difference Euler implicit scheme. Energy conservation equations for the solar DHW components models have been coupled by means of a home-made implicit algorithm. Results of the simulation performed using as input data the experimental values of the ambient temperature and the solar irradiance in a summer day are presented and discussed.

  5. Domestic hot water and solar energy in Ireland

    Energy Technology Data Exchange (ETDEWEB)

    Hand, F; Asare, B; Haslett, J

    1977-01-01

    Two systems are discussed which involve the use of solar energy to supply domestic hot-water requirements and their usefulness in Ireland is examined. The systems are evaluated for thermal performance and cost-effectiveness by the use of a computer simulation model of a system involving a typical commercially available solar panel. It is shown that such systems may be economically justified when compared with electricity, but only if the water supply is directly heated by solar panels and only if the installed cost of such panels is low. Further, it appears that the system performance is relatively insensitive to the panel orientation and consequently that retro-fit installations on existing houses are unlikely to cause difficulties.

  6. Installation package for a solar heating and hot water system

    Science.gov (United States)

    1978-01-01

    Development and installation of two commercial solar heating and hot water systems are reported. The systems consist of the following subsystems: collector, storage, transport, hot water, auxiliary energy and controls. General guidelines are provided which may be utilized in development of detailed installation plans and specifications. In addition, operation, maintenance and repair of a solar heating and hot water system instructions are included.

  7. Energy efficiency of a solar domestic hot water system

    Science.gov (United States)

    Zukowski, Miroslaw

    2017-11-01

    The solar domestic hot water (SDHW) system located on the campus of Bialystok University of Technology is the object of the research described in the current paper. The solar thermal system is composed of 35 flat plate collectors, 21 evacuated tube collectors and eight hot water tanks with the capacity of 1 m3 of each. Solar facility is equipped with hardware for automatic data collection. Additionally, the weather station located on the roof of the building provides measurements of basic parameters of ambient air and solar radiation. The main objective of Regional Operational Program was the assessment of the effectiveness of this solar energy technology in the climatic conditions of the north-eastern Poland. Energy efficiency of SDHW system was defined in this research as the ratio between the useful heat energy supplied to the domestic hot water system and solar energy incident on the surface of solar panels. Heat loss from water storage tanks, and from the pipe network to the surrounding air, as well as the electrical energy consumed by the pumps have been included in the calculations. The paper presents the detailed results and conclusions obtained from this energy analysis.

  8. Prototype solar heating and hot water system

    Science.gov (United States)

    1977-01-01

    Progress is reported in the development of a solar heating and hot water system which uses a pyramidal optics solar concentrator for heating, and consists of the following subsystems: collector, control, transport, and site data acquisition. Improvements made in the components and subsystems are discussed.

  9. Solar system for domestic hot water and space heating

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, W. [Arbeitsgemeinschaf Erneubare Energie, Gleisdorf (Austria)

    1997-12-31

    The solar thermal markets, different types of solar systems for hot water and space heating, the dimensioning and the components of solar heating systems, the properties of the systems are reviewed in this presentation

  10. Solar system for domestic hot water and space heating

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, W [Arbeitsgemeinschaf Erneubare Energie, Gleisdorf (Austria)

    1998-12-31

    The solar thermal markets, different types of solar systems for hot water and space heating, the dimensioning and the components of solar heating systems, the properties of the systems are reviewed in this presentation

  11. Solar-powered hot-air system

    Science.gov (United States)

    1979-01-01

    Solar-powered air heater supplies part or all of space heating requirements of residential or commercial buildings and is interfaced with air to water heat exchanger to heat domestic hot water. System has potential application in drying agricultural products such as cotton, lumber, corn, grains, and peanuts.

  12. Preliminary design package for solar heating and hot water system

    Science.gov (United States)

    1976-01-01

    Two prototype solar heating and hot water systems for use in single-family dwellings or commercial buildings were designed. Subsystems included are: collector, storage, transport, hot water, auxiliary energy, and government-furnished site data acquisition. The systems are designed for Yosemite, California, and Pueblo, Colorado. The necessary information to evaluate the preliminary design for these solar heating and hot water systems is presented. Included are a proposed instrumentation plan, a training program, hazard analysis, preliminary design drawings, and other information about the design of the system.

  13. Solar Hot Water System Matter in Turkey (Mersin Case

    Directory of Open Access Journals (Sweden)

    Müjgan ŞEREFHANOĞLU SÖZEN

    2010-01-01

    Full Text Available When the effects of sustainability on the construction sector have been taken into consideration, solar active systems on buildings emerge as an important design issue in the context of renewal energy usage. Solar hot water systems such as those widely used in Turkey are inefficient and have a negative effect on a building’s aesthetic and the urban view in general because of the poor quality of installation. Natural circulated open loop systems are commonly used, particularly in the south of Turkey, as they are highly economical and require no regulation to install. Solar hot water systems tend to be clustered together on the roofs, causing visual pollution, and this situation arises largely because are not considered part of the architectural design. It is therefore important to consider the negative effects of such systems in the form of treatment studies. This study aims to determine the positive effects that will be gained by the renovation of solar hot water systems in Mersin, a city in the southern region of Turkey.

  14. Experimental study of multipurpose solar hot box at Freiburg, Germany

    Energy Technology Data Exchange (ETDEWEB)

    Nandwani, S.S. [Iowa State University, Ames (United States). International Inst. of Theoretical and Applied Physics; Steinhart, J.; Henning, H.M.; Rommel, M.; Wittwer, V. [Fraunhofer-Institut fuer Solare Energiesysteme (ISE), Freiburg im Breisgau (Germany)

    1997-12-31

    With the aim to test an compare some properties of materials and common geometries that are used for designing solar cookers, water heaters, etc. we have made a solar hot box with two similar compartments. In the present study this hot box has been used for, (a) comparing the behavior of a metallic slab filled with a phase change material for short term heat storage, with a conventional absorbing sheet, (b) the use of a selectively coated, as compared to a normal black painted, cooking pot, and (c) for finding the overall heat loss coefficient and thermal capacity of the box. Experiments with the solar hot box will yield valuable information on solar systems that are to be constructed. Besides its use for research this multi-purpose device has been used both to pasteurize up to 14-16 l of water and for cooking. (author)

  15. Collective solar hot water: best practices

    International Nuclear Information System (INIS)

    Beutin, Philippe; Grouzard, Patrice; Coroller, Francoise

    2005-10-01

    This brochure, edited by ADEME, the French office for energy management and sustainable development, gives a collection of good practices concerning the selection and installation of collective solar water heating systems in France. A first note presents the Garantie de Resultats solaires (GRS - Guarantee of Solar Results), a kind of certification that gives a long term guarantee of the annual solar energy produced quantity as a function of the hot water consumption. An overview of the collective solar market is given, followed by informations on the financial incentives for feasibility studies and installations, the technical design and optimization of a collective solar project, its economic assessment, etc. Numerous examples of collective of solar heating operations in collective buildings are presented, in various regions of France, in the east (Alsace), the center (Auvergne, Ile de France (Paris region)), and the south (Languedoc-Roussillon, Midi-Pyrennes, PACA), giving technical data, financing, partnerships, etc

  16. Center-to-Limb Variability of Hot Coronal EUV Emissions During Solar Flares

    Science.gov (United States)

    Thiemann, E. M. B.; Chamberlin, P. C.; Eparvier, F. G.; Epp, L.

    2018-02-01

    It is generally accepted that densities of quiet-Sun and active region plasma are sufficiently low to justify the optically thin approximation, and this is commonly used in the analysis of line emissions from plasma in the solar corona. However, the densities of solar flare loops are substantially higher, compromising the optically thin approximation. This study begins with a radiative transfer model that uses typical solar flare densities and geometries to show that hot coronal emission lines are not generally optically thin. Furthermore, the model demonstrates that the observed line intensity should exhibit center-to-limb variability (CTLV), with flares observed near the limb being dimmer than those occurring near disk center. The model predictions are validated with an analysis of over 200 flares observed by the EUV Variability Experiment (EVE) on the Solar Dynamics Observatory (SDO), which uses six lines, with peak formation temperatures between 8.9 and 15.8 MK, to show that limb flares are systematically dimmer than disk-center flares. The data are then used to show that the electron column density along the line of sight typically increases by 1.76 × 10^{19} cm^{-2} for limb flares over the disk-center flare value. It is shown that the CTLV of hot coronal emissions reduces the amount of ionizing radiation propagating into the solar system, and it changes the relative intensities of lines and bands commonly used for spectral analysis.

  17. A novel solar hot plate for cooking

    Energy Technology Data Exchange (ETDEWEB)

    Rincon Mejia, Eduardo A; Osorio Jaramillo, Fidel A [Facultad de Ingenieria, UAEMex, Toluca, Edo. (Mexico)

    2000-07-01

    In Mexico and other developing countries, the use of firewood as combustible for cooking has contributed to deforestation and desertification of large zones. This is due to the lack of alternative combustibles for the poor inhabitants of the countryside and remote areas. In this paper, a new solar hot plate, intended for contributing to solve this problem, is presented. It can be used for cooking not only a great variety of prehispanic and traditional meals, like tortillas, fried meat and vegetables, but also hot cakes, bacon, eggs, steaks and fries. The hot plate solar cooker, called Tolocatzin, consists of a horizontal metallic plate, which is heated from both of its top and bottom surfaces by concentrated sun light from multicompound concentrator based on nonimaging optics, and built with nine ordinary plane glass-silvered, and two curved aluminum mirrors, so it can be manufactured easily in a small factory or at home. For an acceptance angle of 15 Celsius degrees, which allows the concentration of sun light without sun-tracking for about one hour, it can reach temperatures up to 240 Celsius degrees in a few minutes. This temperature is high enough for cooking almost all fried or grilled meals. The design was optimized using ray-trace procedures. The operational experience with early prototypes has shown that the Tolocatzin solar hot plate does an excellent cooking job and could really be massively used in sunny countries. [Spanish] En Mexico y otros paises en desarrollo, el uso de la madera como combustible para cocinar ha contribuido a la deforestacion y desertificacion de grandes zonas. Esto es debido a la falta de combustibles alternativos por parte de los habitantes pobres del campo y de areas remotas. En este articulo se presenta una nueva placa solar que tiene el proposito de contribuir a resolver este problema. Puede ser usada para cocinar no solamente una gran variedad de comidas prehispanicas y tradicionales, como tortillas, carne frita y verduras sino

  18. Design data brochure: Solar hot air heater

    Science.gov (United States)

    1978-01-01

    The design, installation, performance, and application of a solar hot air heater for residential, commercial and industrial use is reported. The system has been installed at the Concho Indian School in El Reno, Oklahoma.

  19. Single-nanowire, low-bandgap hot carrier solar cells with tunable open-circuit voltage

    Science.gov (United States)

    Limpert, Steven; Burke, Adam; Chen, I.-Ju; Anttu, Nicklas; Lehmann, Sebastian; Fahlvik, Sofia; Bremner, Stephen; Conibeer, Gavin; Thelander, Claes; Pistol, Mats-Erik; Linke, Heiner

    2017-10-01

    Compared to traditional pn-junction photovoltaics, hot carrier solar cells offer potentially higher efficiency by extracting work from the kinetic energy of photogenerated ‘hot carriers’ before they cool to the lattice temperature. Hot carrier solar cells have been demonstrated in high-bandgap ferroelectric insulators and GaAs/AlGaAs heterostructures, but so far not in low-bandgap materials, where the potential efficiency gain is highest. Recently, a high open-circuit voltage was demonstrated in an illuminated wurtzite InAs nanowire with a low bandgap of 0.39 eV, and was interpreted in terms of a photothermoelectric effect. Here, we point out that this device is a hot carrier solar cell and discuss its performance in those terms. In the demonstrated devices, InP heterostructures are used as energy filters in order to thermoelectrically harvest the energy of hot electrons photogenerated in InAs absorber segments. The obtained photovoltage depends on the heterostructure design of the energy filter and is therefore tunable. By using a high-resistance, thermionic barrier, an open-circuit voltage is obtained that is in excess of the Shockley-Queisser limit. These results provide generalizable insight into how to realize high voltage hot carrier solar cells in low-bandgap materials, and therefore are a step towards the demonstration of higher efficiency hot carrier solar cells.

  20. Identification and assessment of environmental benefits from solar hot water production

    International Nuclear Information System (INIS)

    Haralambopoulos, D.; Spilanis, I.

    1997-01-01

    The environmental benefits associated with the utilization of solar energy for hot water production are estimated in this work. The case of a particular country, Greece, and its electricity production system is employed to show the direct consequences of substituting electricity with solar energy for hot water production. The amount of conventional fuel saved, i.e. lignite and oil, is estimated, and the reduction in air pollution is calculated. This allows the calculation of reduction emission factors for solar hot water production to be undertaken. Data, with respect to the materials and the amount of energy necessary for the construction of the solar heaters, are also presented. These can serve as inputs to an energy-environment policy framework in order to lead to reduction of air pollutants like SO 2 , NO X and particulates, and the release of the greenhouse gas CO 2 into the atmosphere. (Author)

  1. Design data brochure: Solar hot water system

    Science.gov (United States)

    1978-01-01

    A design calculation is detailed for a single-family residence housing a family of four in a nonspecific geographical area. The solar water heater system is designed to provide 80 gallons of 140 F hot water per day.

  2. Study on Thermal Performance Assessment of Solar Hot Water Systems in Malaysia

    Directory of Open Access Journals (Sweden)

    Sulaiman Shaharin Anwar

    2014-07-01

    Full Text Available Solar Hot Water Systems (SHWS are gaining popularity in Malaysia due to increasing cost of electricity and also awareness of environmental issues related to the use of fossil fuels. The introduction of solar hot water systems in Malaysia is an indication that it has potential market. However, there is a need for a proper methodology for rating the energy performance of these systems. The main objective of this study is to assess the thermal performance of several SHWS subject to four different locations in Malaysia using combined direct measurement and computer modelling using the TRNSYS simulation program. The results showed distinct differences in performance of the systems as a result of locations and manufacturers. The findings could be used further in developing an acceptable rating system for SHWS in Malaysia.

  3. Solar hot water systems application to the solar building test facility and the Tech House

    Science.gov (United States)

    Goble, R. L.; Jensen, R. N.; Basford, R. C.

    1976-01-01

    Projects which relate to the current national thrust toward demonstrating applied solar energy are discussed. The first project has as its primary objective the application of a system comprised of a flat plate collector field, an absorption air conditioning system, and a hot water heating system to satisfy most of the annual cooling and heating requirements of a large commercial office building. The other project addresses the application of solar collector technology to the heating and hot water requirements of a domestic residence. In this case, however, the solar system represents only one of several important technology items, the primary objective for the project being the application of space technology to the American home.

  4. Prototype solar heating and cooling systems including potable hot water

    Science.gov (United States)

    1978-01-01

    Progress is reviewed in the development, delivery, and support of two prototype solar heating and cooling systems including potable hot water. The system consisted of the following subsystems: collector, auxiliary heating, potable hot water, storage, control, transport, and government-furnished site data acquisition.

  5. Installation package for a domestic solar heating and hot water system

    Science.gov (United States)

    1978-01-01

    The installation of two prototype solar heating and hot water systems is described. The systems consists of the following subsystems: solar collector, storage, control, transport, and auxiliary energy.

  6. Thermal analysis and performance optimization of a solar hot water plant with economic evaluation

    KAUST Repository

    Kim, Youngdeuk

    2012-05-01

    The main objective of this study is to optimize the long-term performance of an existing active-indirect solar hot water plant (SHWP), which supplies hot water at 65 °C for use in a flight kitchen, using a micro genetic algorithm in conjunction with a relatively detailed model of each component in the plant and solar radiation model based on the measured data. The performance of SHWP at Changi International Airport Services (CIASs), Singapore, is studied for better payback period using the monthly average hourly diffuse and beam radiations and ambient temperature data. The data input for solar radiation model is obtained from the Singapore Meteorological Service (SMS), and these data have been compared with long-term average data of NASA (surface meteorology and solar energy or SSE). The comparison shows a good agreement between the predicted and measured hourly-averaged, horizontal global radiation. The SHWP at CIAS, which comprises 1200m 2 of evacuated-tube collectors, 50m 3 water storage tanks and a gas-fired auxiliary boiler, is first analyzed using a baseline configuration, i.e., (i) the local solar insolation input, (ii) a coolant flow rate through the headers of collector based on ASHRAE standards, (iii) a thermal load demand pattern amounting to 100m 3/day, and (iv) the augmentation of water temperature by auxiliary when the supply temperature from solar tank drops below the set point. A comparison between the baseline configuration and the measured performance of CIAS plant gives reasonably good validation of the simulation code. Optimization is further carried out for the following parameters, namely; (i) total collector area of the plant, (ii) storage volume, and (iii) three daily thermal demands. These studies are performed for both the CIAS plant and a slightly modified plant where the hot water supply to the load is adjusted constant at times when the water temperature from tank may exceed the set temperature. It is found that the latter

  7. Thermal analysis and performance optimization of a solar hot water plant with economic evaluation

    KAUST Repository

    Kim, Youngdeuk; Thu, Kyaw; Bhatia, Hitasha Kaur; Bhatia, Charanjit Singh; Ng, K. C.

    2012-01-01

    The main objective of this study is to optimize the long-term performance of an existing active-indirect solar hot water plant (SHWP), which supplies hot water at 65 °C for use in a flight kitchen, using a micro genetic algorithm in conjunction with a relatively detailed model of each component in the plant and solar radiation model based on the measured data. The performance of SHWP at Changi International Airport Services (CIASs), Singapore, is studied for better payback period using the monthly average hourly diffuse and beam radiations and ambient temperature data. The data input for solar radiation model is obtained from the Singapore Meteorological Service (SMS), and these data have been compared with long-term average data of NASA (surface meteorology and solar energy or SSE). The comparison shows a good agreement between the predicted and measured hourly-averaged, horizontal global radiation. The SHWP at CIAS, which comprises 1200m 2 of evacuated-tube collectors, 50m 3 water storage tanks and a gas-fired auxiliary boiler, is first analyzed using a baseline configuration, i.e., (i) the local solar insolation input, (ii) a coolant flow rate through the headers of collector based on ASHRAE standards, (iii) a thermal load demand pattern amounting to 100m 3/day, and (iv) the augmentation of water temperature by auxiliary when the supply temperature from solar tank drops below the set point. A comparison between the baseline configuration and the measured performance of CIAS plant gives reasonably good validation of the simulation code. Optimization is further carried out for the following parameters, namely; (i) total collector area of the plant, (ii) storage volume, and (iii) three daily thermal demands. These studies are performed for both the CIAS plant and a slightly modified plant where the hot water supply to the load is adjusted constant at times when the water temperature from tank may exceed the set temperature. It is found that the latter

  8. Preliminary design package for solar hot water system

    Energy Technology Data Exchange (ETDEWEB)

    Fogle, Val; Aspinwall, David B.

    1977-12-01

    The information necessary to evaluate the preliminary design of the Solar Engineering and Manufacturing Company's (SEMCO) solar hot water system is presented. This package includes technical information, schematics, drawings and brochures. This system, being developed by SEMCO, consists of the following subsystems: collector, storage, transport, control, auxiliary energy, and Government-furnished site data acquisition. The two units being manufactured will be installed at Loxahatchee, Florida, and Macon, Georgia.

  9. Solar hot water system installed at Las Vegas, Nevada. Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-01-01

    The solar hot water system installed at LaQuinta Motor Inn Inc., at Las Vegas, Nevada is described. The Inn is a three-story building with a flat roof for installation of the solar panels. The system consists of 1200 square feet of liquid flat plate collectors, a 2500 gallon insulated vertical steel storage tank, two heat exchangers and pumps and controls. The system was designed to supply approximately 74 percent of the total hot water load.

  10. Solar heating and domestic hot water system installed at Kansas City, Fire Stations, Kansas City, Missouri

    Science.gov (United States)

    1980-01-01

    The solar system was designed to provide 47 percent of the space heating, 8,800 square feet area and 75 percent of the domestic hot water (DHW) load. The solar system consists of 2,808 square feet of Solaron, model 2001, air, flat plate collector subsystem, a concrete box storage subsystem which contains 1,428 cubic feet of 0.5 inch diameter pebbles weighing 71.5 tons, a DHW preheat tank, blowers, pumps, heat exchangers, air ducting, controls and associated plumbing. Two 120 gallon electric DHW heaters supply domestic hot water which is preheated by the solar system. Auxiliary space heating is provided by three electric heat pumps with electric resistance heaters and four 30 kilowatt electric unit heaters. There are six modes of system operation.

  11. Solar heating and domestic hot water system installed at Kansas City, Fire Stations, Kansas City, Missouri

    Science.gov (United States)

    1980-07-01

    The solar system was designed to provide 47 percent of the space heating, 8,800 square feet area and 75 percent of the domestic hot water (DHW) load. The solar system consists of 2,808 square feet of Solaron, model 2001, air, flat plate collector subsystem, a concrete box storage subsystem which contains 1,428 cubic feet of 0.5 inch diameter pebbles weighing 71.5 tons, a DHW preheat tank, blowers, pumps, heat exchangers, air ducting, controls and associated plumbing. Two 120 gallon electric DHW heaters supply domestic hot water which is preheated by the solar system. Auxiliary space heating is provided by three electric heat pumps with electric resistance heaters and four 30 kilowatt electric unit heaters. There are six modes of system operation.

  12. Solar Energy for Domestic Hot Water: Case Studies in Sisimiut 1999-2005

    DEFF Research Database (Denmark)

    Reimann, Gregers Peter

    2005-01-01

    Two pioneer solar domestic hot water systems were installed at Bygge- og Anlægsskolen in Sisimiut in 1999 and 2000. Detailed measurements of energy flows and solar radiation incl. snow reflectance has been undertaken for both plants. Since August 2004 data logging of the measurements was made...... available online on the website www.arcticsolar.com. Measurements show that solar plant 1 and 2 cover 22% and 23%, respectively, of the energy spent for domestic hot water heating. This paper summarises the findings from the past 5 years....

  13. Drying hot red pepper using solar tunnel drier

    International Nuclear Information System (INIS)

    Hossain, M.A; Bala, B.K.

    2006-01-01

    A solar tunnel drier was used to dry red hot pepper under the tropical weather conditions of Bangladesh in order to investigate its performance and the quality of the drier product. The drier comprises a plastic sheet-covered flat plate collector and a drying tunnel. The drier is arranged to supply hot air to the drying tunnel using two small fans powered by a 40 watt PV module. Fresh red pepper was water blanched before drying. In each drying batch in the solar tunnel drier, 20 kg of dried red pepper with 4 to 6% moisture content (wb) was obtained from 80 kg of fresh red pepper with initial moisture content of 73 to 75% (wb) in 20 to 22 hours of drying while it took 32 to 34 hours to bring down the moisture content of similar sample to 8 to 10% (wb) in sun drying methods. The pepper dried in the solar tunnel drier was completely protected from dust, dirt, rain, insects, birds, rodents and microorganisms and it was a quality-dried product in term of colour and pungency. The solar tunnel drier is recommended for drying of pepper as well as vegetables and fruits in developing countries especially in Bangladesh

  14. Application of solar energy to the supply of hot water for textile dyeing. Final report, CDRL/PA 10

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-09-01

    The design plan for a solar process hot water system for a textile dye beck at Riegel Textile Corporation's LaFrance, South Carolina, facilities is presented. The solar system consists of 396 GE model TC 100 evacuated tube collector modules arranged in a ground mounted array with a total collector area of 6680 square feet. The system includes an 8000-gallon hot water storage tank. Systems analyses, specification sheets, performance data, and an economic evaluation of the proposed system are presented. (WHK)

  15. Solar heating and hot water system installed at Saint Louis, Missouri

    Science.gov (United States)

    1980-01-01

    The solar heating and hot water system installed at the William Tao & Associates, Inc., office building in St. Louis, Missouri is described, including maintenance and construction problems, final drawings, system requirements, and manufacturer's component data. The solar system was designed to provide 50 percent of the hot water requirements and 45 percent of the space heating needs for a 900 sq ft office space and drafting room. The solar facility has 252 sq ft of glass tube concentrator collectors and a 1000 gallon steel storage tank buried below a concrete slab floor. Freeze protection is provided by a propylene glycol/water mixture in the collector loop. The collectors are roof mounted on a variable tilt array which is adjusted seasonally and is connected to the solar thermal storage tank by a tube-in-shell heat exchanger. Incoming city water is preheated through the solar energy thermal storage tank.

  16. Solar hot water system installed at Quality Inn, Key West, Florida

    Science.gov (United States)

    1980-04-01

    The solar energy hot water system installed in the Quality Inn, Key West, Florida, which consists of four buildings is described. Three buildings are low-rise, two-story buildings containing 100 rooms. The fourth is a four-story building with 48 rooms. The solar system was designed to provide approximately 50 percent of the energy required for the domestic hot water system. The solar system consists of approximately 1400 square feet of flat plate collector, two 500 gallon storage tanks, a circulating pump, and a controller. Operation of the system was begun in April 1978, and has continued to date with only three minor interruptions for pump repair. In the first year of operation, it was determined that the use of the solar facility resulted in forty percent fuel savings.

  17. Analysis of systems for hot water supply with solar energy utilization

    International Nuclear Information System (INIS)

    Zlateva, M.

    2001-01-01

    The results from the analysis of the hot water consumption of a group of hotels in the Black See resort Albena are presented. Structural schemes of hot water solar systems with flat plate collectors have been synthesized. By the synthesis have been analyzed the type of the consumers, the operating period, the existing heating plants, the auxiliary energy source - electricity. The change of the solar fraction by different performance of the system have been investigated. A comparative analysis of the alternative solutions has been fulfilled. The most advantageous solution has been chosen on the basis of the evaluation of the pay-back period, the life cycle savings and the benefit-cost ratio. The effect of the changing economic characteristics on the economic efficiency have been investigated. The risk for the investments has been examined. It had been proved that for the conditions in Bulgarian Black See region the use of solar energy for hot water producing is economic reasonable. (author)

  18. Optimum hot water temperature for absorption solar cooling

    Energy Technology Data Exchange (ETDEWEB)

    Lecuona, A.; Ventas, R.; Venegas, M.; Salgado, R. [Dpto. Ingenieria Termica y de Fluidos, Universidad Carlos III de Madrid, Avda. Universidad 30, 28911 Leganes, Madrid (Spain); Zacarias, A. [ESIME UPA, IPN, Av. de las Granjas 682, Col. Santa Catarina, 02550, D.F. Mexico (Mexico)

    2009-10-15

    The hot water temperature that maximizes the overall instantaneous efficiency of a solar cooling facility is determined. A modified characteristic equation model is used and applied to single-effect lithium bromide-water absorption chillers. This model is based on the characteristic temperature difference and serves to empirically calculate the performance of real chillers. This paper provides an explicit equation for the optimum temperature of vapor generation, in terms of only the external temperatures of the chiller. The additional data required are the four performance parameters of the chiller and essentially a modified stagnation temperature from the detailed model of the thermal collector operation. This paper presents and discusses the results for small capacity machines for air conditioning of homes and small buildings. The discussion highlights the influence of the relevant parameters. (author)

  19. Ayres' bifurcated solar model

    International Nuclear Information System (INIS)

    Kalkofen, W.

    1985-01-01

    The assumptions of Ayres' model of the upper solar atmosphere are examined. It is found that the bistable character of his model is postulated - through the assumptions concerning the opacity sources and the effect of mechanical waves, which are allowed to destroy the CO molecules but not to heat the gas. The neglect of cooling by metal lines is based on their reduced local cooling rate, but it ignores the increased depth over which this cooling occurs. Thus, the bifurcated model of the upper solar atmosphere consists of two models, one cold at the temperature minimum, with a kinetic temperature of 2900 K, and the other hot, with a temperature of 4900 K. 8 references

  20. Motel solar-hot-water system with nonpressurized storage--Jacksonville, Florida

    Science.gov (United States)

    1981-01-01

    Modular roof-mounted copper-plated arrays collect solar energy; heated water drains from them into 1,000 gallon nonpressurized storage tank which supplies energy to existing pressurized motel hot water lines. System provides 65 percent of hot water demand. Report described systems parts and operation, maintenance, and performance and provides warranty information.

  1. Usage of solar aggregate stockpiles in the production of hot mix asphalt

    International Nuclear Information System (INIS)

    Androjić, Ivica; Kaluđer, Gordana

    2016-01-01

    Highlights: • Low energy storage mineral mixtures. • The impact of models thermal insulation on the temperature of aggregate. • Effect of periods with no solar radiation on the aggregate accumulated heat. • Low energy storage saves energy for preheating mineral mixtures. - Abstract: The production process of hot mix asphalt (HMA) requires a considerable demand for thermal energy which is fed into the process of drying and heating of mineral mixture. An overview of solar aggregate stockpiles designed in order to reduce energy consumption is given. Solar stockpiles were designed with the primary goal of achieving as much accumulation of thermal energy obtained from solar radiation as possible during the exposure period. Models of solar stockpiles were made with a constant volume capacity, variable thermal insulation thickness in the range of 2, 5 and 10 cm, and a glass ceiling surface to allow the realisation of high solar transmission into the interior of a stockpile. Temperature measurement of the mineral mixture deposited in the solar models and of those exposed to external environmental conditions was conducted during the period from May to November, 2015. The results achieved indicate to the facts that there comes to the constant growth in warmth of mineral mixtures in insulated stockpiles for the duration of their exposure to solar radiation, that an increase in thermal insulation thickness leads to the quadratic functional dependence between the referred thickness and mixture temperature and, ultimately, that there comes to the exponential loss of an accumulated thermal energy in insulated models in the period with no effect of solar radiation.

  2. Using Solar Hot Water to Address Piping Heat Losses in Multifamily Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Springer, David [Alliance for Residential Building Innovation, Davis, CA (United States); Seitzler, Matt [Alliance for Residential Building Innovation, Davis, CA (United States); Backman, Christine [Alliance for Residential Building Innovation, Davis, CA (United States); Weitzel, Elizabeth [Alliance for Residential Building Innovation, Davis, CA (United States)

    2015-10-01

    Solar thermal water heating is most cost effective when applied to multifamily buildings and some states offer incentives or other inducements to install them. However, typical solar water heating designs do not allow the solar generated heat to be applied to recirculation losses, only to reduce the amount of gas or electric energy needed for hot water that is delivered to the fixtures. For good reasons, hot water that is recirculated through the building is returned to the water heater, not to the solar storage tank. The project described in this report investigated the effectiveness of using automatic valves to divert water that is normally returned through the recirculation piping to the gas or electric water heater instead to the solar storage tank. The valves can be controlled so that the flow is only diverted when the returning water is cooler than the water in the solar storage tank.

  3. Imitation experiment for water-treatment by heat of solar collector and hot pump

    International Nuclear Information System (INIS)

    Liao Yuanzong; Liu Shuqing; Pang Heding; Zhao Zhongxin; Zhang Biguang; Wang Xiping; Huo Guangqing

    1997-01-01

    The author presents an imitation experiment in which solar collector and hot pump are jointed for supplying heat to evaporate cleaned water and diffuse it into air. The effects of the temperature and the quantity of supplying air, and circumstance conditions on evaporation quantity are studied. The ratio of evaporating quantity to consuming energy, the efficiency of evaporation, average efficiency of solar collector and supplying heat coefficient of heat pump are measured. The experiment shows that this supplying heat model is practicable, economic and efficient for treating cleaned water

  4. Quantitative experimental assessment of hot carrier-enhanced solar cells at room temperature

    Science.gov (United States)

    Nguyen, Dac-Trung; Lombez, Laurent; Gibelli, François; Boyer-Richard, Soline; Le Corre, Alain; Durand, Olivier; Guillemoles, Jean-François

    2018-03-01

    In common photovoltaic devices, the part of the incident energy above the absorption threshold quickly ends up as heat, which limits their maximum achievable efficiency to far below the thermodynamic limit for solar energy conversion. Conversely, the conversion of the excess kinetic energy of the photogenerated carriers into additional free energy would be sufficient to approach the thermodynamic limit. This is the principle of hot carrier devices. Unfortunately, such device operation in conditions relevant for utilization has never been evidenced. Here, we show that the quantitative thermodynamic study of the hot carrier population, with luminance measurements, allows us to discuss the hot carrier contribution to the solar cell performance. We demonstrate that the voltage and current can be enhanced in a semiconductor heterostructure due to the presence of the hot carrier population in a single InGaAsP quantum well at room temperature. These experimental results substantiate the potential of increasing photovoltaic performances in the hot carrier regime.

  5. Air-cooled LiBr-water absorption chillers for solar air conditioning in extremely hot weathers

    International Nuclear Information System (INIS)

    Kim, D.S.; Infante Ferreira, C.A.

    2009-01-01

    A low temperature-driven absorption cycle is theoretically investigated for the development of an air-cooled LiBr-water absorption chiller to be combined with low-cost flat solar collectors for solar air conditioning in hot and dry regions. The cycle works with dilute LiBr-water solutions so that risk of LiBr crystallization is less than for commercially available water-cooled LiBr-water absorption chillers even in extremely hot ambient conditions. Two-phase heat exchangers in the system were modelled taking account of the heat and mass transfer resistances in falling film flows by applying the film theory in thermal and concentration boundary layers. Both directly and indirectly air-cooled chillers were modelled by properly combining component models and boundary conditions in a matrix system and solved with an algebraic equation solver. Simulation results predict that the chillers would deliver chilled water around 7.0 deg. C with a COP of 0.37 from 90 deg. C hot water under 35 deg. C ambient condition. At 50 deg. C ambient temperature, the chillers retained about 36% of their cooling power at 35 deg. C ambient. Compared with the directly air-cooled chiller, the indirectly air-cooled chiller presented a cooling power performance reduction of about 30%

  6. Solar heating and hot water system installed at Shoney's Restaurant, North Little Rock, Arkansas

    Science.gov (United States)

    1980-01-01

    A solar heating system designed to supply a major portion of the space and water heating requirements for a restaurant is described. The restaurant has a floor space of approximately 4,650 square feet and requires approximate 1500 gallons of hot water daily. The solar energy system consists of 1,428 square feet of Chamberlain flat plate liquid collector subsystem, and a 1500 gallon storage subsystem circulating hot water producing 321 x 10 to the 6th power Btu/Yr (specified) building heating and hot water heating.

  7. Establishment and verification of solar radiation calculation model of glass daylighting roof in hot summer and warm winter zone in China

    OpenAIRE

    Zheng, Caidan; Wu, Peihao; Costanzo, Vincenzo; Wang, Yuchen; Yang, Xiaokun

    2017-01-01

    In this paper, solar heat gain through glass daylighting roof is deeply studied by theoretical calculation method, taking Guangzhou in the Hot Summer and Warm Winter (HSWW) zone as an example. The direct solar radiation is calculated by Bouguer formula whereas the diffuse solar radiation is calculated by Berlage formula, representing the basis for the calculation method of the solar radiation intensity through the glass daylighting roof. Through the establishment of solar radiation calculatio...

  8. Solar heating and hot water system installed at Arlington Raquetball Club, Arlington, Virginia

    Science.gov (United States)

    1981-01-01

    A solar space and water heating system is described. The solar energy system consists of 2,520 sq. ft. of flat plate solar collectors and a 4,000 gallon solar storage tank. The transfer medium in the forced closed loop is a nontoxic antifreeze solution (50 percent water, 50 percent propylene glycol). The service hot water system consists of a preheat coil (60 ft. of 1 1/4 in copper tubing) located in the upper third of the solar storage tank and a recirculation loop between the preheat coil and the existing electric water heaters. The space heating system consists of two separate water to air heat exchangers located in the ducts of the existing space heating/cooling systems. The heating water is supplied from the solar storage tank. Extracts from site files, specification references for solar modifications to existing building heating and hot water systems, and installation, operation and maintenance instructions are included.

  9. Advantages using inlet stratification devices in solar domestic hot water storage tanks

    DEFF Research Database (Denmark)

    Dragsted, Janne; Furbo, Simon; Bava, Federico

    2017-01-01

    performances of two solar domestic hot water systems are presented. One system is a traditional high flow system with a heat exchanger spiral in the tank. The other system is a low flow system with an external heat exchanger and a newly developed inlet stratifier from EyeCular Technologies ApS installed......The thermal performance of a domestic hot water system is strongly affected by whether the storage tank is stratified or not. Thermal stratification can be built up in a solar storage tank if the heated water from the solar collectors enters the tank through an inlet stratifier.Measured thermal...... with the stratification device has a higher thermal performance compared to the system with the heat exchanger spiral inside the tank.The relative performance (defined as the ratio between the net utilized solar energy of the low flow system and the net utilized solar energy of the high flow system), is a function...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-11-01

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

  11. Anomalous energy transport in hot plasmas: solar corona and Tokamak

    International Nuclear Information System (INIS)

    Beaufume, P.

    1992-04-01

    Anomalous energy transport is studied in two hot plasmas and appears to be associated with a heating of the solar corona and with a plasma deconfining process in tokamaks. The magnetic structure is shown to play a fundamental role in this phenomenon through small scale instabilities which are modelized by means of a nonlinear dynamical system: the Beasts' Model. Four behavior classes are found for this system, which are automatically classified in the parameter space thanks to a neural network. We use a compilation of experimental results relative to the solar corona to discuss current-based heating processes. We find that a simple Joule effect cannot provide the required heating rates, and therefore propose a dimensional model involving a resistive reconnective instability which leads to an efficient and discontinuous heating mechanism. Results are in good agreement with the observations. We give an analytical expression for a diffusion coefficient in tokamaks when magnetic turbulence is perturbing the topology, which we validate thanks to the standard mapping. A realistic version of the Beasts' Model allows to test a candidate to anomalous transport: the thermal filamentation instability

  12. X-ray emitting hot plasma in solar active regions observed by the SphinX spectrometer

    Science.gov (United States)

    Miceli, M.; Reale, F.; Gburek, S.; Terzo, S.; Barbera, M.; Collura, A.; Sylwester, J.; Kowalinski, M.; Podgorski, P.; Gryciuk, M.

    2012-08-01

    Aims: The detection of very hot plasma in the quiescent corona is important for diagnosing heating mechanisms. The presence and the amount of such hot plasma is currently debated. The SphinX instrument on-board the CORONAS-PHOTON mission is sensitive to X-ray emission of energies well above 1 keV and provides the opportunity to detect the hot plasma component. Methods: We analysed the X-ray spectra of the solar corona collected by the SphinX spectrometer in May 2009 (when two active regions were present). We modelled the spectrum extracted from the whole Sun over a time window of 17 days in the 1.34-7 keV energy band by adopting the latest release of the APED database. Results: The SphinX broadband spectrum cannot be modelled by a single isothermal component of optically thin plasma and two components are necessary. In particular, the high statistical significance of the count rates and the accurate calibration of the spectrometer allowed us to detect a very hot component at ~7 million K with an emission measure of ~2.7 × 1044 cm-3. The X-ray emission from the hot plasma dominates the solar X-ray spectrum above 4 keV. We checked that this hot component is invariably present in both the high and low emission regimes, i.e. even excluding resolvable microflares. We also present and discuss the possibility of a non-thermal origin (which would be compatible with a weak contribution from thick-target bremsstrahlung) for this hard emission component. Conclusions: Our results support the nanoflare scenario and might confirm that a minor flaring activity is ever-present in the quiescent corona, as also inferred for the coronae of other stars.

  13. System design package for SIMS prototype system 3, solar heating and domestic hot water

    Energy Technology Data Exchange (ETDEWEB)

    1978-11-01

    This report is a collation of documents and drawings that describe a prototype solar heating and hot water system using liquid flat plat collectors and a gas or electric furnace energy subsystem. The system was designed for installation into a single-family dwelling. The description, performance specification, subsystem drawings, verification plan/procedure, and hazard analysis of the system are packaged for evaluation of the system with information sufficient to assemble a similar system. The SIMS Prototype Heating and Hot Water System, Model Number 3 has been installed in a residence at Glendo State Park, Glendo, Wyoming.

  14. Improved model for solar heating of buildings

    OpenAIRE

    Lie, Bernt

    2015-01-01

    A considerable future increase in the global energy use is expected, and the effects of energy conversion on the climate are already observed. Future energy conversion should thus be based on resources that have negligible climate effects; solar energy is perhaps the most important of such resources. The presented work builds on a previous complete model for solar heating of a house; here the aim to introduce ventilation heat recovery and improve on the hot water storage model. Ventilation he...

  15. Building America Case Study: Addressing Multifamily Piping Losses with Solar Hot Water, Davis, California

    Energy Technology Data Exchange (ETDEWEB)

    2016-12-01

    Solar thermal water heating is most cost effective when applied to multifamily buildings and some states offer incentives or other inducements to install them. However, typical solar water heating designs do not allow the solar generated heat to be applied to recirculation losses, only to reduce the amount of gas or electric energy needed for hot water that is delivered to the fixtures. For good reasons, hot water that is recirculated through the building is returned to the water heater, not to the solar storage tank. The project described in this report investigated the effectiveness of using automatic valves to divert water that is normally returned through the recirculation piping to the gas or electric water heater instead to the solar storage tank. The valves can be controlled so that the flow is only diverted when the returning water is cooler than the water in the solar storage tank.

  16. Long term performance of a solar floor and hot water heating house; Taiyonetsu yukadanbo kyuto jutaku no choki seino

    Energy Technology Data Exchange (ETDEWEB)

    Udagawa, M [Kogakuin University, Tokyo (Japan)

    1997-11-25

    Outlined herein are measured energy consumption followed for 12 years for a totally electrified solar house with a floor-heating and hot-water heating system. In the solar system, hot water generated by the solar collector is sent, via a surge tank, to a living room, dining room and study to heat their concrete floors, and recycled back to the collector after heating the heat-storage tank for hot water supply. The collector is of plate type, consisting of 6 units, each with a white glass sheet as the heat-collecting membrane for selectively absorbing heat. Its total heat-collecting area is 11.4m{sup 2}. Long-term performance of the solar system installed for floor and hot-water heating in a totally electrified solar house, is analyzed by the measured results collected for 12 years. The house consumes secondary energy of 11.7MWh/year on the average, which is approximately 20% lower that that required for a house of the equivalent size. The solar system has been operated smoothly, to supply 46 and 35% of the required heat for hot-water and floor heating. It is however estimated that annual heat loss reaches 34% in the hot-water heating system, including that in the electric hot-water generator, and prevention of heat loss is one of the major themes for the future system designs. 4 refs., 5 figs.

  17. Methods of accounting the hot water consumption modes at the solar installations design

    Directory of Open Access Journals (Sweden)

    Vyacheslav O. Dubkovsky

    2015-06-01

    Full Text Available Peculiarities of the high-powered solar systems for hot water heating are considered. The purpose of work consists in development of methods for accounting the 24-hourly hot water consumption mode, determining the solar systems dynamic descriptions. The basic solar system schemes are analyzed with their shortages from the user satisfaction view point due to sun energy. For the dynamic parameters improvement the use of operative expense tank is examined such receptacle bearing built-in worm-pipe, through which all heat carrier from solar collectors passes before entering the fast heat exchanger which heats a tank-accumulator. The scientific novelty refers to the proof that this tank principal parameter is a not the volume, but the built-in exchanger capacity, determined by the solar collectors field total thermal power. As an ecological constituent of operating costs it is suggested to take into account cost paid for the emission of combustion products. As this method practical application example considered is the solar collectors capacity optimization for a communal enterprise.

  18. Simulation of the interaction of a solar domestic hot water tank system with a compact plate heat exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Nizami, D.J.; Lightstone, M.F. [McMaster Univ., Hamilton, ON (Canada). Dept. of Mechanical Engineering; Harrison, S.; Cruickshank, C. [Queen' s Univ., Kingston, ON (Canada). Dept. of Mechanical and Materials Engineering

    2008-08-15

    An external natural convection heat exchanger (NCHE) was used as an alternative to forced convection for transferring energy from solar collector loops to a hot water storage tank. A computational fluid dynamics (CFD) program was used to predict interactions between the natural convection-driven side-arm heat exchanger and a hot water storage tank. A solar domestic hot water tank with a vertical compact plate natural convection heat exchanger was modelled. In addition, the heat exchanger was modelled as a section of pipe with high flow resistance and a volumetric energy source. Transient analyses were conducted and the CFD model was then compared with data obtained from laboratory experiments. Simulations were conducted on the fluid domain in order to investigate the influence of the flow on the thermal stratification in the tank, the heat transfer inside the tank, and the natural convection in the tank loop. Buoyancy for an incompressible fluid with constant fluid properties was modelled using a Boussinesq approximation. Temperature distributions were measured as a function of time. Results of the study indicated that assuming a constant thermal expansion coefficient in evaluation buoyancy forces for a wide range of operating temperatures did not result in accurate predictions. Future studies will model natural convection with a full buoyancy model. 11 refs., 2 tabs., 5 figs.

  19. Solar heating, cooling and domestic hot water system installed at Columbia Gas System Service Corporation, Columbus, Ohio

    Science.gov (United States)

    1980-01-01

    The solar energy system installed in the building has 2,978 sq ft of single axis tracking, concentrating collectors and provides solar energy for space heating, space cooling and domestic hot water. A 1,200,000 Btu/hour water tube gas boiler provides hot water for space heating. Space cooling is provided by a 100 ton hot water fired absorption chiller. Domestic hot water heating is provided by a 50 gallon natural gas domestic storage water heater. Extracts from the site files, specification references, drawings, installation, operation and maintenance instructions are included.

  20. Thermal performance assessment and improvement of a solar domestic hot water tank with PCM in the mantle

    DEFF Research Database (Denmark)

    Deng, Jie; Furbo, Simon; Kong, Weiqiang

    2018-01-01

    To develop an appropriate solar DHW (Domestic Hot Water) tank for residential dwellings and put it into the European solar thermal market for promotion, thermal performance tests of PCM (Phase Change Material) hot water storage tanks of both a prototype and an improved version with a water volume...

  1. Modeling and characterization of double resonant tunneling diodes for application as energy selective contacts in hot carrier solar cells

    Science.gov (United States)

    Jehl, Zacharie; Suchet, Daniel; Julian, Anatole; Bernard, Cyril; Miyashita, Naoya; Gibelli, Francois; Okada, Yoshitaka; Guillemolles, Jean-Francois

    2017-02-01

    Double resonant tunneling barriers are considered for an application as energy selective contacts in hot carrier solar cells. Experimental symmetric and asymmetric double resonant tunneling barriers are realized by molecular beam epitaxy and characterized by temperature dependent current-voltage measurements. The negative differential resistance signal is enhanced for asymmetric heterostructures, and remains unchanged between low- and room-temperatures. Within Tsu-Esaki description of the tunnel current, this observation can be explained by the voltage dependence of the tunnel transmission amplitude, which presents a resonance under finite bias for asymmetric structures. This effect is notably discussed with respect to series resistance. Different parameters related to the electronic transmission of the structure and the influence of these parameters on the current voltage characteristic are investigated, bringing insights on critical processes to optimize in double resonant tunneling barriers applied to hot carrier solar cells.

  2. High performance in low-flow solar domestic hot water systems

    Energy Technology Data Exchange (ETDEWEB)

    Dayan, M.

    1997-12-31

    Low-flow solar hot water heating systems employ flow rates on the order of 1/5 to 1/10 of the conventional flow. Low-flow systems are of interest because the reduced flow rate allows smaller diameter tubing, which is less costly to install. Further, low-flow systems result in increased tank stratification. Lower collector inlet temperatures are achieved through stratification and the useful energy produced by the collector is increased. The disadvantage of low-flow systems is the collector heat removal factor decreases with decreasing flow rate. Many solar domestic hot water systems require an auxiliary electric source to operate a pump in order to circulate fluid through the solar collector. A photovoltaic driven pump can be used to replace the standard electrical pump. PV driven pumps provide an ideal means of controlling the flow rate, as pumps will only circulate fluid when there is sufficient radiation. Peak performance was always found to occur when the heat exchanger tank-side flow rate was approximately equal to the average load flow rate. For low collector-side flow rates, a small deviation from the optimum flow rate will dramatically effect system performance.

  3. Solar hot-water generation and heating - Kombi-Kompakt+

    International Nuclear Information System (INIS)

    Haller, M.; Vogelsanger, P.

    2005-01-01

    This final report for the Swiss Federal Office of Energy (SFOE) describes new testing facilities at the Institute for Solar Technology in Rapperswil, Switzerland, that allow the testing of solar systems the whole year through. The systems tested feature the combined generation of heat for hot water storage vessels and heat for space heating. The test method used, the Concise Cycle Test (CCT) is described. The results of tests made on a large number of systems demonstrate that it is especially important to have a test system that allows the solar market to be protected from unsatisfactory systems. Good co-operation with manufactures is noted. As the test method includes tests with secondary energy sources such as oil or gas, certain problems in this area were discovered and corrected. Further tests are to be made with systems using biomass as a secondary source of heat

  4. Prototype Solar Domestic Hot Water Systems (A collation of Quarterly Reports)

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-02-01

    This report is a collection of quarterly reports from Solar Engineering and Manufacturing Company (SEMCO) covering the period from November 1976 through September 1977. SEMCO, under NASA/MSFC Contract NAS8-32248, is developing two prototype solar domestic hot water systems consisting of the following subsystems: collector, storage, control, transport, and auxiliary energy. These two systems are being installed at sites in Loxahatchee, Florida (OTS-27) and Macon, Georgia (OTS-28).

  5. Experimental Validation of a Domestic Stratified Hot Water Tank Model in Modelica for Annual Performance Assessment

    DEFF Research Database (Denmark)

    Carmo, Carolina; Dumont, Olivier; Nielsen, Mads Pagh

    2015-01-01

    The use of stratified hot water tanks in solar energy systems - including ORC systems - as well as heat pump systems is paramount for a better performance of these systems. However, the availability of effective and reliable models to predict the annual performance of stratified hot water tanks...

  6. Retrofitted Solar Domestic Hot Water Systems for Swedish Single-Family Houses—Evaluation of a Prototype and Life-Cycle Cost Analysis

    Directory of Open Access Journals (Sweden)

    Luis Ricardo Bernardo

    2016-11-01

    Full Text Available According to recent technology road maps, system cost reductions and development of standardised plug-and-function systems are some of the most important goals for solar heating technology development. Retrofitting hot water boilers in single-family houses when installing solar collectors has the potential to significantly reduce both material and installation costs. Previous studies have investigated such retrofitting, using theoretical simulations and laboratory tests, but no actual installations were made and tested in practice. This article describes the installation, measured performance and cost effectiveness of a retrofitting solution that converts existing domestic hot water heaters to a solar domestic hot water system. The measured performance is characterised by the monthly and annual solar fractions. The cost effectiveness is evaluated by a life-cycle cost analysis, comparing the retrofitted system to a conventional solar domestic hot water system and the case without any solar heating system. Measurements showed that approximately 50% of the 5000 kWh/year of domestic hot water consumption was saved by the retrofitted system in south Sweden. Such savings are in agreement with previous estimations and are comparable to the energy savings when using a conventional solar domestic hot water system. The life-cycle cost analysis showed that, according to the assumptions and given climate, the return on investment of the retrofitted system is approximately 17 years, while a conventional system does not reach profitability during its lifetime of 25 years.

  7. An assessment of solar hot water heating in the Washington, D.C. area - Implications for local utilities

    Science.gov (United States)

    Stuart, M. W.

    1980-04-01

    A survey of residential solar hot water heating in the Washington, D.C. area is presented with estimates of the total solar energy contribution per year. These estimates are examined in relation to a local utility's peak-load curves to determine the impact of a substantial increase in solar domestic hot water use over the next 20 yr in the area of utility management. The results indicate that a 10% market penetration of solar water heaters would have no detrimental effect on the utility's peak-load profile and could save several million dollars in new plant construction costs.

  8. Preliminary design package for solar heating and hot water system

    Science.gov (United States)

    1977-01-01

    The preliminary design review on the development of a multi-family solar heating and domestic hot water prototype system is presented. The report contains the necessary information to evaluate the system. The system consists of the following subsystems: collector, storage, transport, control and Government-furnished site data acquisition.

  9. Design and modeling of low temperature solar thermal power station

    International Nuclear Information System (INIS)

    Shankar Ganesh, N.; Srinivas, T.

    2012-01-01

    Highlights: ► The optimum conditions are different for efficiency and power conditions. ► The current model works up to a maximum separator temperature of 150 °C. ► The turbine concentration influences the high pressure. ► High solar beam radiation and optimized cycle conditions give low collector cost. -- Abstract: During the heat recovery in a Kalina cycle, a binary aqua–ammonia mixture changes its state from liquid to vapor, the more volatile ammonia vaporizes first and then the water starts vaporization to match temperature profile of the hot fluid. In the present work, a low temperature Kalina cycle has been investigated to optimize the heat recovery from solar thermal collectors. Hot fluid coming from solar parabolic trough collector with vacuum tubes is used to generate ammonia rich vapor in a boiler for power generation. The turbine inlet conditions are optimized to match the variable hot fluid temperature with the intermittent nature of the solar radiation. The key parameters discussed in this study are strong solution concentration, separator temperature which affects the hot fluid inlet temperature and turbine ammonia concentration. Solar parabolic collector system with vacuum tubes has been designed at the optimized power plant conditions. This work can be used in the selection of boiler, separator and turbine conditions to maximize the power output as well as efficiency of power generation system. The current model results a maximum limit temperature for separator as 150 °C at the Indian climatic conditions. A maximum specific power of 105 kW per kg/s of working fluid can be obtained at 80% of strong solution concentration with 140 °C separator temperature. The corresponding plant and cycle efficiencies are 5.25% and 13% respectively. But the maximum efficiencies of 6% and 15% can be obtained respectively for plant and Kalina cycle at 150 °C of separator temperature.

  10. Solar heating and hot water system installed at Listerhill, Alabama

    Science.gov (United States)

    1978-01-01

    The Solar system was installed into a new building and was designed to provide 79% of the estimated annual space heating load and 59% of the estimated annual potable hot water requirement. The collectors are flat plate, liquid manufactured by Reynolds Metals Company and cover a total area of 2344 square feet. The storage medium is water inhibited with NALCO 2755 and the container is an underground, unpressurized steel tank with a capacity of 5000 gallons. This report describes in considerable detail the solar heating facility and contains detailed drawings of the completed system.

  11. Solar heating and hot water system installed at Cherry Hill, New Jersey

    Science.gov (United States)

    1979-01-01

    The solar heating and hot water system installed in existing buildings at the Cherry Hill Inn in Cherry Hill, New Jersey is described in detail. The system is expected to furnish 31.5% of the overall heating load and 29.8% of the hot water load. The collectors are liquid evacuated tube type. The storage system is an above ground insulated steel water tank with a capacity of 7,500 gallons.

  12. Technology Solutions for New and Existing Homes Case Study: Addressing Multifamily Piping Losses with Solar Hot Water

    Energy Technology Data Exchange (ETDEWEB)

    D. Springer, M. Seitzler, and C. Backman

    2016-12-01

    Sun Light & Power, a San Francisco Bay Area solar design-build contractor, teamed with the U.S. Department of Energy’s Building America partner the Alliance for Residential Building Innovation (ARBI) to study this heat-loss issue. The team added three-way valves to the solar water heating systems for two 40-unit multifamily buildings. In these systems, when the stored solar hot water is warmer than the recirculated hot water returning from the buildings, the valves divert the returning water to the solar storage tank instead of the water heater. This strategy allows solar-generated heat to be applied to recirculation heat loss in addition to heating water that is consumed by fixtures and appliances.

  13. Development of domestic hot water systems in Costa Rica from solar energy

    International Nuclear Information System (INIS)

    Lizana-Moreno, Fernando

    2015-01-01

    A software tool is developed to implement the solar domestic hot water systems (DHW) in Costa Rica and to replace the electric water heating equipment. A database with information from the solar radiation is elaborated for different locations in Costa Rica. A manual of design DHW solar systems is realized for the country. An DHW solar system is designed for the type of average building the of country. A software is implemented to calculate the parameters and dimensions necessary for the solar installation of DHW, using the F-Chart method; in addition, the information of the mentioned database is included. A financial analysis is elaborated of the DHW solar systems in Costa Rica. The strategies are proposed for the implementation of DHW solar systems in Costa Rica [es

  14. Development of a direct expansion solar assisted heat pump for hot water supply

    International Nuclear Information System (INIS)

    Abdesselam Hamloui; Ong, K.S.; Than Cheok Fah; Masjuki Hassan

    2000-01-01

    Experimental investigations were conducted on the direct expansion solar assisted Heat Pump (DESAHP). Refrigerant R-22 was expanded in the solar collector which also acted as the evaporator in a conventional vapor compression refrigerating machine. The experiments were conducted under conditions of high and low solar radiation, with evaporator completely shaded from the sun, and at night. System thermal performance was determined by measuring refrigerant flow rate, temperature and pressure at numerous points in the system. The results showed that 227-l of water could be heated from 3O degree to 55 degree C in about 105 minutes. Higher water temperatures were obtained during hot sunny days. The coefficient of performance of heating, COP h , ranged from 11 to 4.7, depending upon operating conditions. The total saving of electric energy during hot sunny days was about 460 %. It means that for 1 kWh of electrical input to the system, we achieve 4.6 kWh. This percentage decreases as the evaporator temperature decreases and is a function of solar energy input. (Author)

  15. Solar electricity: An effective asset to supply urban loads in hot climates

    Science.gov (United States)

    Robert, Fabien Chidanand; Gopalan, Sundararaman

    2018-04-01

    While human population has been multiplied by four in the last hundred years, the world energy consumption was multiplied by ten. The common method of using fossil fuels to provide energy and electricity has dangerously disturbed nature's and climate's balance. It has become urgent and crucial to find sustainable and eco-friendly alternatives to preserve a livable environment with unpolluted air and water. Renewable energy is the unique eco-friendly opportunity known today. The main challenge of using renewable energy is to ensure the constant balance of electricity demand and generation on the electrical grid. This paper investigates whether the solar electricity generation is correlated with the urban electricity consumption in hot climates. The solar generation and total consumption have been compared for three cities in Florida. The hourly solar generation has been found to be highly correlated with the consumption that occurs 6 h later, while the monthly solar generation is correlated with the monthly energy consumption. Producing 30% of the electricity using solar energy has been found to compensate partly for the monthly variation in the urban electricity demand. In addition, if 30% of the world electricity is produced using solar, global CO2 emissions would be reduced by 11.7% (14.6% for India). Thus, generating 30% solar electricity represents a valuable asset for urban areas situated in hot climates, reducing the need for electrical operating reserve, providing local supply with minimal transmission losses, but above all reducing the need for fossil fuel electricity and reducing global CO2 emission.

  16. Retrofitting Domestic Hot Water Heaters for Solar Water Heating Systems in Single-Family Houses in a Cold Climate: A Theoretical Analysis

    Directory of Open Access Journals (Sweden)

    Björn Karlsson

    2012-10-01

    Full Text Available One of the biggest obstacles to economic profitability of solar water heating systems is the investment cost. Retrofitting existing domestic hot water heaters when a new solar hot water system is installed can reduce both the installation and material costs. In this study, retrofitting existing water heaters for solar water heating systems in Swedish single-family houses was theoretically investigated using the TRNSYS software. Four simulation models using forced circulation flow with different system configurations and control strategies were simulated and analysed in the study. A comparison with a standard solar thermal system was also presented based on the annual solar fraction. The simulation results indicate that the retrofitting configuration achieving the highest annual performance consists of a system where the existing tank is used as storage for the solar heat and a smaller tank with a heater is added in series to make sure that the required outlet temperature can be met. An external heat exchanger is used between the collector circuit and the existing tank. For this retrofitted system an annual solar fraction of 50.5% was achieved. A conventional solar thermal system using a standard solar tank achieves a comparable performance for the same total storage volume, collector area and reference conditions.

  17. Combined Active and Passive Solar Space Heating and Solar Hot Water Systems for an Elementary School in Boise, Idaho.

    Science.gov (United States)

    Smull, Neil A.; Armstrong, Gerald L.

    1979-01-01

    Amity Elementary School in Boise, Idaho, features a solar space heating and domestic hot water system along with an earth covering to accommodate the passive aspects of energy conservation. (Author/MLF)

  18. Solar heating and domestic hot water system installed at North Dallas High School

    Science.gov (United States)

    1980-01-01

    The solar energy system located at the North Dallas High School, Dallas, Texas is discussed. The system is designed as a retrofit in a three story with basement, concrete frame high school building. Extracts from the site files, specification references for solar modification to existing building heating and domestic hot water systems, drawings, installation, operation and maintenance instructions are included.

  19. Verification test report on a solar heating and hot water system

    Science.gov (United States)

    1978-01-01

    Information is provided on the development, qualification and acceptance verification of commercial solar heating and hot water systems and components. The verification includes the performances, the efficiences and the various methods used, such as similarity, analysis, inspection, test, etc., that are applicable to satisfying the verification requirements.

  20. Investigation af a solar heating system for space heating and domestic hot water supply with a high degree of coverage

    DEFF Research Database (Denmark)

    Vejen, Niels Kristian

    1999-01-01

    A solar storage tank for space heating and domestic hot water supply was designed and testet in af laboratory test facility.......A solar storage tank for space heating and domestic hot water supply was designed and testet in af laboratory test facility....

  1. Assessing the economic aspects of solar hot water production in Greece

    International Nuclear Information System (INIS)

    Haralambopoulos, D.; Kovras, H.

    1997-01-01

    The long-term performance of various systems was determined and the economic aspects of solar hot water production were investigated in this work. The effect of the collector inclination angle, collector area and storage volume was examined for all systems, and various climatic conditions and their payback period was calculated. It was found that the collector inclination angle does not have a significant effect on system performance. Large collector areas have a diminishing effect on the system's overall efficiency. The increase in storage volume has a detrimental effect for small daily load volumes, but a beneficial one when there is a large daily consumption. Solar energy was found to be truly competitive when the conventional fuel being substituted is electricity, and it should not replace diesel oil on pure economic grounds. Large daily load volumes and large collector areas are in general associated with shorter payback periods. Overall, the systems are oversized and are economically suitable for large daily hot water load volumes. (Author)

  2. Theoretical model and experimental validation of a direct-expansion solar assisted heat pump for domestic hot water applications

    International Nuclear Information System (INIS)

    Moreno-Rodríguez, A.; González-Gil, A.; Izquierdo, M.; Garcia-Hernando, N.

    2012-01-01

    This paper has shown the development of a theoretical model to determine the operating parameters and consumption of a domestic hot water (DHW) installation, which uses a direct-expansion solar assisted heat pump (DXSAHP) with refrigerant R-134a, a compressor with a rated capacity of 1.1 kW and collectors with a total area of 5.6 m 2 . The model results have been compared and validated the experimental results obtained with the equipment installed at the University Carlos III, South of Madrid. The analysis was conducted over the course of a year, and the results have been represented depending on the meteorological and process variables of several representative days. Taking into account the thermal losses of the installation and the dependency on the operating conditions, the acquired experimental coefficient of performance is between 1.7 and 2.9, while the DHW tank temperature over the course of the study is 51 °C. -- Highlights: ► The study aims to present a new theoretical model and an experimental validation. ► The experimental COP vary between 1.7 and 2.9 (max. condensation temperature 57 °C). ► The operating parameters respond to the solar radiation. The COP may increase up to 50%. ► The useful surface area varies between 50% and 85% of the total surface. ► The system stops if conditions exceed the maximum value of the absorbed heat.

  3. An experimental investigation with artificial sunlight of a solar hot-water heater

    Science.gov (United States)

    Simon, F. F.

    1976-01-01

    Thermal performance measurements were made of a commercial solar hot water heater in a solar simulator to determine basic performance characteristics of a traditional type of flat plate collector, with and without side reflectors (to increase the solar flux). Information on each of the following was obtained; (1) the effect of flow and incidence angle on the efficiency of a flat plate collector (but only without side reflectors); (2) transient performance under flow and nonflow conditions; (3) the effectiveness of reflectors to increase collector efficiency for a zero radiation angle at fluid temperatures required for solar air conditioning; and (4) the limits of applicability of a collector efficiency correlation based on the Hottel Whillier equation.

  4. Hot-carrier solar cells using low-dimensional quantum structures

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Daiki; Kasamatsu, Naofumi; Harada, Yukihiro; Kita, Takashi [Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501 (Japan)

    2014-10-27

    We propose a high-conversion-efficiency solar cell (SC) utilizing the hot carrier (HC) population in an intermediate-band (IB) of a quantum dot superlattice (QDSL) structure. The bandgap of the host semiconductor in this device plays an important role as an energy-selective barrier for HCs in the QDSLs. According to theoretical calculation using the detailed balance model with an air mass 1.5 spectrum, the optimum IB energy is determined by a trade-off relation between the number of HCs with energy exceeding the conduction-band edge and the number of photons absorbed by the valence band−IB transition. Utilizing experimental data of HC temperature in InAs/GaAs QDSLs, the maximum conversion efficiency under maximum concentration (45 900 suns) has been demonstrated to increase by 12.6% as compared with that for a single-junction GaAs SC.

  5. Detailed Physical Trough Model for NREL's Solar Advisor Model: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, M. J.; Blair, N.; Dobos, A.

    2010-10-01

    Solar Advisor Model (SAM) is a free software package made available by the National Renewable Energy Laboratory (NREL), Sandia National Laboratory, and the US Department of Energy. SAM contains hourly system performance and economic models for concentrating solar power (CSP) systems, photovoltaic, solar hot-water, and generic fuel-use technologies. Versions of SAM prior to 2010 included only the parabolic trough model based on Excelergy. This model uses top-level empirical performance curves to characterize plant behavior, and thus is limited in predictive capability for new technologies or component configurations. To address this and other functionality challenges, a new trough model; derived from physical first principles was commissioned to supplement the Excelergy-based empirical model. This new 'physical model' approaches the task of characterizing the performance of the whole parabolic trough plant by replacing empirical curve-fit relationships with more detailed calculations where practical. The resulting model matches the annual performance of the SAM empirical model (which has been previously verified with plant data) while maintaining run-times compatible with parametric analysis, adding additional flexibility in modeled system configurations, and providing more detailed performance calculations in the solar field, power block, piping, and storage subsystems.

  6. Hot kinetic model as a guide to improve organic photovoltaic materials.

    Science.gov (United States)

    Sosorev, Andrey Yu; Godovsky, Dmitry Yu; Paraschuk, Dmitry Yu

    2018-01-31

    The modeling of organic solar cells (OSCs) can provide a roadmap for their further improvement. Many OSC models have been proposed in recent years; however, the impact of the key intermediates from photons to electricity-hot charge-transfer (CT) states-on the OSC efficiency is highly ambiguous. In this study, we suggest an analytical kinetic model for OSC that considers a two-step charge generation via hot CT states. This hot kinetic model allowed us to evaluate the impact of different material parameters on the OSC performance: the driving force for charge separation, optical bandgap, charge mobility, geminate recombination rate, thermalization rate, average electron-hole separation distance in the CT state, dielectric permittivity, reorganization energy and charge delocalization. In contrast to a widespread trend of lowering the material bandgap, the model predicts that this approach is only efficient along with improvement of the other material properties. The most promising ways to increase the OSC performance are decreasing the reorganization energy, i.e., an energy change accompanying CT from the donor molecule to the acceptor, increasing the dielectric permittivity and charge delocalization. The model suggests that there are no fundamental limitations that can prevent achieving the OSC efficiency above 20%.

  7. Simulation of the solar hot water systems diffusion: the case of Greece

    International Nuclear Information System (INIS)

    Sidiras, D.; Koukios, E.

    2004-01-01

    The main object of this paper is the documentation and study of the main factors behind the spectacular diffusion of solar energy use for domestic hot water production in Greece. The time pattern of the diffusion of flat-plate solar collectors since its 'out of the blue' first appearance in 1974, shows that the diffusion rate grew exponentially at first, with the annual sales figure reaching 91,000 m 2 by 1980. A rate slow down in the early 1980s was followed by a brief period of explosive growth, with the annual sales figure reaching its peak value of more than 185,000 m 2 in mid-1980s. A rapid decline of the growth rate down to the present annual sales level followed. The installed solar collectors pattern has the characteristic form of an S-shape curve, representing the overall penetration of the flat-plate solar collector use for domestic hot water production in the Greek economy and society. This evolution has gone through an inflection point around 1987, i.e. at a time when about 1,000,000 m 2 of collectors had already been installed. By the year 2000, about 2,070,000 m 2 of collectors had been installed, with a tendency to level off by 2010, unless some the present conditions determining this phenomenon change. (author)

  8. The impact of the hot tap water load pattern in the industrial hall on the energy yield from solar collectors

    Science.gov (United States)

    Fidorów-Kaprawyl, Natalia; Dudkiewicz, Edyta

    2017-11-01

    The systems using solar energy, popular in Poland, can be used to supply hot water for the installation used by employees of industrial halls. In manufacturing plants, employing a large number of people, the demand for hot water is practically constant throughout the year and is characterized by periodic use at the end of each work shift. Dynamics of the hot water consumption depends on the number of shifts as well as working days and holidays. Additionally the maximum hot tap water demand occurs in the whole period of installation operation. In polish climatic conditions the solar collectors' systems have the largest capacity in the summer, while in winter they need to be assisted. Beside that the supply of renewable energy is uneven and depends on weather conditions. In the paper the one-hour step analysis concerning the dependence of the load pattern of the hot tap water preparation system on the energy yield from solar collectors had been performed.

  9. A model for the origin of solar wind stream interfaces

    International Nuclear Information System (INIS)

    Hundhausen, A.J.; Burlaga, L.F.

    1975-01-01

    The basic variations in solar wind properties that have been observed at 'stream interfaces' near 1 AU are explained by a gas dynamic model in which a radially propagating stream, produced by a temperature variation in the solar envelope, steepens nonlinearly while moving through interplanetary space. The region thus identified with the stream interface separates the ambient solar wind from the fresh hot material originally in the stream. However, the interface regions given by the present model are thicker than most stream interfaces observed in the solar wind, a fact suggesting that some additional physical process may be important in determining that thickness. Variations in the density, speed, or Alfven pressure alone appear not to produce streams with such an interface

  10. Design package for a complete residential solar space heating and hot water system

    Science.gov (United States)

    1978-01-01

    Information necessary to evaluate the design of a solar space heating and hot water system is reported. System performance specifications, the design data brochure, the system description, and other information pertaining to the design are included.

  11. American Recovery and Reinvestment Act (ARRA) Federal Energy Management Program Technical Assistance Project 281 Solar Hot Water Application Assessment for U.S. Army IMCOM-Southeast Region

    Energy Technology Data Exchange (ETDEWEB)

    Russo, Bryan J.; Chvala, William D.

    2010-09-30

    The Energy Independence and Security Act of 2007 requires installations (EISA) to install solar systems of sufficient capacity to provide 30% of service hot water in new construction and renovations where cost-effective. However, installations are struggling with how to implement solar hot water, and while several installations are installing solar hot water on a limited basis, paybacks remain long. Pacific Northwest National Laboratory (PNNL) was tasked to address this issue to help determine how best to implement solar hot water projects. This documents discusses the results of that project.

  12. HOT PLASMA FROM SOLAR ACTIVE-REGION CORES: CONSTRAINTS FROM THE HINODE X-RAY TELESCOPE

    Energy Technology Data Exchange (ETDEWEB)

    Schmelz, J. T. [USRA, 7178 Columbia Gateway Drive, Columbia, MD 21046 (United States); Christian, G. M.; Matheny, P. O., E-mail: jschmelz@usra.edu [Physics Department, University of Memphis, Memphis, TN 38152 (United States)

    2016-12-20

    Mechanisms invoked to heat the solar corona to millions of degrees kelvin involve either magnetic waves or magnetic reconnections. Turbulence in the convection zone produces MHD waves, which travel upward and dissipate. Photospheric motions continuously build up magnetic energy, which is released through magnetic reconnection. In this paper, we concentrate on hot non-flaring plasma with temperatures of 5 MK <  T  < 10 MK because it is one of the few observables for which wave and reconnection models make different predictions. Wave models predict no (or little) hot plasma, whereas reconnection models predict it, although in amounts that are challenging to detect with current instrumentation. We used data from the X-ray Telescope (XRT) and the Atmospheric Imaging Assembly (AIA). We requested a special XRT observing sequence, which cycled through the thickest XRT filter several times per hour so we could average these images and improve the signal-to-noise. We did differential emission measure (DEM) analysis using the time-averaged thick-filter data as well as all available channels from both the XRT and AIA for regions observed on 2014 December 11. Whereas our earlier work was only able to determine that plasma with a temperature greater than 5 MK was present , we are now able to find a well-constrained DEM distribution. We have therefore added a strong observational constraint that must be explained by any viable coronal heating model. Comparing state-of-the-art wave and reconnection model predictions, we can conclude that reconnection is heating the hot plasma in these active regions.

  13. Hot wire deposited hydrogenated amorphous silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Mahan, A.H.; Iwaniczko, E.; Nelson, B.P.; Reedy, R.C. Jr.; Crandall, R.S. [National Renewable Energy Lab., Golden, CO (United States)

    1996-05-01

    This paper details the results of a study in which low H content, high deposition rate hot wire (HW) deposited amorphous silicon (a-Si:H) has been incorporated into a substrate solar cell. The authors find that the treatment of the top surface of the HW i layer while it is being cooled from its high deposition temperature is crucial to device performance. They present data concerning these surface treatments, and correlate these treatments with Schottky device performance. The authors also present first generation HW n-i-p solar cell efficiency data, where a glow discharge (GD) {mu}c-Si(p) layer was added to complete the partial devices. No light trapping layer was used to increase the device Jsc. Their preliminary investigations have yielded efficiencies of up to 6.8% for a cell with a 4000 {Angstrom} thick HW i-layer, which degrade less than 10% after a 900 hour light soak. The authors suggest avenues for further improvement of their devices.

  14. Modelling Hot Air Balloons.

    Science.gov (United States)

    Brimicombe, M. W.

    1991-01-01

    A macroscopic way of modeling hot air balloons using a Newtonian approach is presented. Misleading examples using a car tire and the concept of hot air rising are discussed. Pressure gradient changes in the atmosphere are used to explain how hot air balloons work. (KR)

  15. Design of nanophotonic, hot-electron solar-blind ultraviolet detectors with a metal-oxide-semiconductor structure

    International Nuclear Information System (INIS)

    Wang, Zhiyuan; Wang, Xiaoxin; Liu, Jifeng

    2014-01-01

    Solar-blind ultraviolet (UV) detection refers to photon detection specifically in the wavelength range of 200 nm–320 nm. Without background noises from solar radiation, it has broad applications from homeland security to environmental monitoring. The most commonly used solid state devices for this application are wide band gap (WBG) semiconductor photodetectors (Eg > 3.5 eV). However, WBG semiconductors are difficult to grow and integrate with Si readout integrated circuits (ROICs). In this paper, we design a nanophotonic metal-oxide-semiconductor structure on Si for solar-blind UV detectors. Instead of using semiconductors as the active absorber, we use Sn nano-grating structures to absorb UV photons and generate hot electrons for internal photoemission across the Sn/SiO 2 interfacial barrier, thereby generating photocurrent between the metal and the n-type Si region upon UV excitation. Moreover, the transported hot electron has an excess kinetic energy >3 eV, large enough to induce impact ionization and generate another free electron in the conduction band of n-Si. This process doubles the quantum efficiency. On the other hand, the large metal/oxide interfacial energy barrier (>3.5 eV) also enables solar-blind UV detection by blocking the less energetic electrons excited by visible photons. With optimized design, ∼75% UV absorption and hot electron excitation can be achieved within the mean free path of ∼20 nm from the metal/oxide interface. This feature greatly enhances hot electron transport across the interfacial barrier to generate photocurrent. The simple geometry of the Sn nano-gratings and the MOS structure make it easy to fabricate and integrate with Si ROICs compared to existing solar-blind UV detection schemes. The presented device structure also breaks through the conventional notion that photon absorption by metal is always a loss in solid-state photodetectors, and it can potentially be extended to other active metal photonic devices. (paper)

  16. Solar heating and hot water system installed at Cherry Hill, New Jersey. [Hotels

    Energy Technology Data Exchange (ETDEWEB)

    1979-05-16

    The solar heating and hot water system installed in existing buildings at the Cherry Hill Inn in Cherry Hill, New Jersey is described in detail. The system went into operation November 8, 1978 and is expected to furnish 31.5% of the overall heating load and 29.8% of the hot water load. The collectors are General Electric Company liquid evacuated tube type. The storage system is an above ground insulated steel water tank with a capacity of 7,500 gallons.

  17. Solar heating and hot water system installed at Southeast of Saline, Unified School District 306, Mentor, Kansas

    Science.gov (United States)

    1979-01-01

    The solar system, installed in a new building, was designed to provide 52 percent of the estimated annual space heating load and 84 percent of the estimated annual potable hot water requirement. The liquid flat plate collectors are ground-mounted and cover a total area of 5125 square feet. The system will provide supplemental heat for the school's closed-loop water-to-air heat pump system and domestic hot water. The storage medium is water inside steel tanks with a capacity of 11,828 gallons for space heating and 1,600 gallons for domestic hot water. The solar heating facility is described and drawings are presented of the completed system which was declared operational in September 1978, and has functioned successfully since.

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

    Science.gov (United States)

    Jaworske, Donald A.; Allen, Bradley J.

    2001-01-01

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

  19. Application of solar energy to the supply of industrial process hot water. Aerotherm final report, 77-235. [Can washing in Campbell Soup plant

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-01-01

    The objectives of the Solar Industrial Process Hot Water Program are to design, test, and evaluate the application of solar energy to the generation and supply of industrial process hot water, and to provide an assessment of the economic and resource benefits to be gained. Other objectives are to stimulate and give impetus to the use of solar energy for supplying significant amounts of industrial process heat requirements. The plant selected for the design of a solar industrial process hot water system was the Campbell Soup facility in Sacramento, California. The total hot water demand for this plant varies between 500 and 800 gpm during regular production shifts, and hits a peak of over 1,000 gpm for approximately one hour during the cleanup shift. Most of the hot water is heated in the boiler room by a combination of waste heat recovery and low pressure (5 psi) steam-water heat exchangers. The hot water emerges from the boiler room at a temperature between 160/sup 0/F and 180/sup 0/F and is transported to the various process areas. Booster heaters in the process areas then use low pressure (5 psi) or medium pressure (20 psi) steam to raise the temperature of the water to the level required for each process. Hot water is used in several processes at the Campbell Soup plant, but the can washing process was selected to demonstrate the feasibility of a solar hot water system. A detailed design and economic analysis of the system is given. (WHK)

  20. Solar heating and hot water system installed at James Hurst Elementary School, Portsmouth, Virginia

    Science.gov (United States)

    1981-01-01

    Solar heating and a hot water system installed in an elementary school in Portsmouth, Virginia are examined. The building is zoned into four heating/cooling areas. Each area is equipped with an air handling unit that is monitored and controlled by central control and monitoring system. The solar system for the building uses a collector area of 3,630 sq. ft. of flat plate liquid collectors, and a 6,000 gallon storage tank. System descriptions, maintenance reports, detailed component specifications, and design drawings to evaluate this solar system are reported.

  1. Solar heating, cooling, and domestic hot water system installed at Kaw Valley State Bank and Trust Company, Topeka, Kansas

    Science.gov (United States)

    1980-01-01

    The building has approximately 5600 square feet of conditioned space. Solar energy was used for space heating, space cooling, and preheating domestic hot water (DHW). The solar energy system had an array of evacuated tube-type collectors with an area of 1068 square feet. A 50/50 solution of ethylene glycol and water was the transfer medium that delivered solar energy to a tube-in-shell heat exchanger that in turn delivered solar heated water to a 1100 gallon pressurized hot water storage tank. When solar energy was insufficient to satisfy the space heating and/or cooling demand, a natural gas-fired boiler provided auxiliary energy to the fan coil loops and/or the absorption chillers. Extracts from the site files, specification references, drawings, and installation, operation and maintenance instructions are presented.

  2. System design package for SIMS Prototype System 4, solar heating and domestic hot water

    Energy Technology Data Exchange (ETDEWEB)

    1978-11-01

    This report is a collation of documents and drawings that describe a prototype solar heating and hot water system using air type solar energy collection techniques. The system consists of a modular designed prepackaged solar unit containing solar collctors, a rock storage container, blowers, dampers, ducting, air-to-water heat exchanger, DHW preheat tank, piping and system controls. The system was designed to be installed adjacent to a small single family dwelling. The description, performance specification, subsystem drawings, verification plan/procedure, and hazard analysis of the system are packaged for evaluation of the system with inforation sufficient to assemble a similar system. The prepackage solar unit has been installed at the Mississippi Power and Light Company, Training Facilities, Clinton, Mississippi.

  3. The Use of Solar Energy for Preparing Domestic Hot Water in a Multi-Storey Building

    Directory of Open Access Journals (Sweden)

    Giedrius Šiupšinskas

    2012-12-01

    Full Text Available The article analyses the possibilities of solar collectors used for a domestic hot water system and installed on the roofs of modernized multi-storey buildings under the existing climate conditions. A number of combinations of flat plate and vacuum solar collectors with accumulation tank systems of various sizes have been examined. Heat from the district heating system is used as an additional heat source for preparing domestic hot water. The paper compares calculation results of energy and economy regarding the combinations of flat plate and vacuum solar collectors and the size of the accumulation tank. The influence of variations in the main indicators on the final economic results has also been evaluated. Research has been supported applying EC FP7 CONCERTO program (‘‘Sustainable Zero Carbon ECO-Town Developments Improving Quality of Life across EU - ECO-Life’’ (ECO-Life Project Contract No. TREN/FP7EN/239497/”ECOLIFE”.Article in Lithuanian

  4. Effects of solar radiation on endurance exercise capacity in a hot environment.

    Science.gov (United States)

    Otani, Hidenori; Kaya, Mitsuharu; Tamaki, Akira; Watson, Phillip; Maughan, Ronald J

    2016-04-01

    The present study investigated the effects of variations in solar radiation on endurance exercise capacity and thermoregulatory responses in a hot environment. Eight male volunteers performed four cycle exercise trials at 70 % maximum oxygen uptake until exhaustion in an environmental chamber maintained at 30 °C and 50 % relative humidity. Volunteers were tested under four solar radiation conditions: 800, 500, 250 and 0 W/m(2). Exercise time to exhaustion was less on the 800 W/m(2) trial (23 ± 4 min) than on all the other trials (500 W/m(2) 30 ± 7 min; P 0.05). Mean skin temperature was higher on the 800 W/m(2) trial than the 250 and 0 W/m(2) trials (P solar radiation increases.

  5. Performance analysis of solar cogeneration system with different integration strategies for potable water and domestic hot water production

    International Nuclear Information System (INIS)

    Uday Kumar, N.T.; Mohan, Gowtham; Martin, Andrew

    2016-01-01

    Highlights: • Solar driven cogeneration system integrating membrane distillation technology is developed. • System utilizes solar thermal energy for the operations without auxiliary heaters. • Three different system integrations are experimentally investigated in UAE. • Economical benefits of solar cogeneration system is also reported. - Abstract: A novel solar thermal cogeneration system featuring the provision of potable water with membrane distillation in combination with domestic hot water supply has been developed and experimentally analyzed. The system integrates evacuated tube collectors, thermal storage, membrane distillation unit, and heat exchangers with the overall goals of maximizing the two outputs while minimizing costs for the given design conditions. Experiments were conducted during one month’s operation at AURAK’s facility in UAE, with average peak global irradiation levels of 650 W/m"2. System performance was determined for three integration strategies, all utilizing brackish water (typical conductivity of 20,000 μs/cm) as a feedstock: Thermal store integration (TSI), which resembles a conventional indirect solar domestic hot water system; Direct solar integration (DSI) connecting collectors directly to the membrane distillation unit without thermal storage; and Direct solar with thermal store integration (DSTSI), a combination of these two approaches. The DSTSI strategy offered the best performance given its operational flexibility. Here the maximum distillate productivity was 43 L/day for a total gross solar collector area of 96 m"2. In terms of simultaneous hot water production, 277 kWh/day was achieved with this configuration. An economic analysis shows that the DSTSI strategy has a payback period of 3.9 years with net cumulative savings of $325,000 during the 20 year system lifetime.

  6. Investigation of a low flow solar heating system for space heating and domestic hot water supply for Aidt Miljø A/S

    DEFF Research Database (Denmark)

    Vejen, Niels Kristian

    1997-01-01

    A low flow solar heating system for space heating and domestic hot water supply from Aidt Miljø A/Swas tested in a laboratory test facility.......A low flow solar heating system for space heating and domestic hot water supply from Aidt Miljø A/Swas tested in a laboratory test facility....

  7. Potential application of solar thermal systems for hot water production in Hong Kong

    International Nuclear Information System (INIS)

    Li Hong; Yang Hongxing

    2009-01-01

    This paper presents the evaluation results of conventional solar water heater (SWH) systems and solar assisted heat pump (SAHP) systems for hot water production in Hong Kong. An economic comparison and global warming impact analysis are conducted among the two kinds of solar thermal systems and traditional water heating systems (i.e. electric water heaters and towngas water heaters). The economic comparison results show that solar thermal systems have greater economic benefits than traditional water heating systems. In addition, conventional SWH systems are comparable with the SAHP systems when solar fractions are above 50%. Besides, analysis on the sensitivity of the total equivalent warming impact (TEWI) indicates that the towngas boosted SWH system has the greatest potential in greenhouse gas emission reduction with various solar collector areas and the electricity boosted SWH system has the comparative TEWI with the SAHP systems if its solar fraction is above 50%. As for SAHP systems, the solar assisted air source heat pump (SA-ASHP) system has the least global warming impact. Based on all investigation results, suggestions are given on the selection of solar thermal systems for applications in Hong Kong

  8. Investigation of a solar heating system for space heating and domestic hot water supply for Sol&Træ A.m.b.a

    DEFF Research Database (Denmark)

    Vejen, Niels Kristian

    1999-01-01

    A solar heating system for space heating and domestic hot water supply from "Sol&Træ A.m.b.a." was tested in a laboratory test facility.......A solar heating system for space heating and domestic hot water supply from "Sol&Træ A.m.b.a." was tested in a laboratory test facility....

  9. Surface-Plasmon-Driven Hot Electron Photochemistry.

    Science.gov (United States)

    Zhang, Yuchao; He, Shuai; Guo, Wenxiao; Hu, Yue; Huang, Jiawei; Mulcahy, Justin R; Wei, Wei David

    2017-11-30

    Visible-light-driven photochemistry has continued to attract heightened interest due to its capacity to efficiently harvest solar energy and its potential to solve the global energy crisis. Plasmonic nanostructures boast broadly tunable optical properties coupled with catalytically active surfaces that offer a unique opportunity for solar photochemistry. Resonant optical excitation of surface plasmons produces energetic hot electrons that can be collected to facilitate chemical reactions. This review sums up recent theoretical and experimental approaches for understanding the underlying photophysical processes in hot electron generation and discusses various electron-transfer models on both plasmonic metal nanostructures and plasmonic metal/semiconductor heterostructures. Following that are highlights of recent examples of plasmon-driven hot electron photochemical reactions within the context of both cases. The review concludes with a discussion about the remaining challenges in the field and future opportunities for addressing the low reaction efficiencies in hot-electron-induced photochemistry.

  10. Primary energy consumption of the dwelling with solar hot water system and biomass boiler

    International Nuclear Information System (INIS)

    Berković-Šubić, Mihaela; Rauch, Martina; Dović, Damir; Andrassy, Mladen

    2014-01-01

    Highlights: • Methodology for determing delivered and primary energy is developed. • Conventional and solar hot water system are analyzed. • Influence of system components, heat losses and energy consumption is explored. • Savings when using solar system in delivered energy is 30% and in primary 75%. • Dwelling with higher Q H,nd has 60% shorter payback period. - Abstract: This paper presents a new methodology, based on the energy performance of buildings Directive related European norms. It is developed to overcome ambiguities and incompleteness of these standards in determining the delivered and primary energy. The available procedures from the present “Algorithm for determining the energy demands and efficiency of technical systems in buildings”, normally used for energy performance certification of buildings, also allow detailed analyzes of the influence of particular system components on the overall system energy efficiency. The calculation example is given for a Croatian reference dwelling, equipped with a solar hot water system, backed up with a biomass boiler for space heating and domestic hot water purposes as a part of the dwelling energy performance certification. Calculations were performed for two cases corresponding to different levels of the dwelling thermal insulation with an appropriate heating system capacity, in order to investigate the influence of the building heat losses on the system design and energy consumption. The results are compared against those obtained for the conventional system with a gas boiler in terms of the primary energy consumption as well as of investment and operating costs. These results indicate great reduction in both delivered and primary energy consumption when a solar system with biomass boiler is used instead of the conventional one. Higher savings are obtained in the case of the dwelling with higher energy need for space heating. Such dwellings also have a shorter payback period than the ones with

  11. Performance analysis of high-concentrated multi-junction solar cells in hot climate

    Science.gov (United States)

    Ghoneim, Adel A.; Kandil, Kandil M.; Alzanki, Talal H.; Alenezi, Mohammad R.

    2018-03-01

    Multi-junction concentrator solar cells are a promising technology as they can fulfill the increasing energy demand with renewable sources. Focusing sunlight upon the aperture of multi-junction photovoltaic (PV) cells can generate much greater power densities than conventional PV cells. So, concentrated PV multi-junction solar cells offer a promising way towards achieving minimum cost per kilowatt-hour. However, these cells have many aspects that must be fixed to be feasible for large-scale energy generation. In this work, a model is developed to analyze the impact of various atmospheric factors on concentrator PV performance. A single-diode equivalent circuit model is developed to examine multi-junction cells performance in hot weather conditions, considering the impacts of both temperature and concentration ratio. The impacts of spectral variations of irradiance on annual performance of various high-concentrated photovoltaic (HCPV) panels are examined, adapting spectra simulations using the SMARTS model. Also, the diode shunt resistance neglected in the existing models is considered in the present model. The present results are efficiently validated against measurements from published data to within 2% accuracy. Present predictions show that the single-diode model considering the shunt resistance gives accurate and reliable results. Also, aerosol optical depth (AOD) and air mass are most important atmospheric parameters having a significant impact on HCPV cell performance. In addition, the electrical efficiency (η) is noticed to increase with concentration to a certain concentration degree after which it decreases. Finally, based on the model predictions, let us conclude that the present model could be adapted properly to examine HCPV cells' performance over a broad range of operating conditions.

  12. Theoretical model of an evacuated tube heat pipe solar collector integrated with phase change material

    International Nuclear Information System (INIS)

    Naghavi, M.S.; Ong, K.S.; Badruddin, I.A.; Mehrali, M.; Silakhori, M.; Metselaar, H.S.C.

    2015-01-01

    The purpose of this paper is to model theoretically a solar hot water system consisting of an array of ETHPSC (evacuated tube heat pipe solar collectors) connected to a common manifold filled with phase change material and acting as a LHTES (latent heat thermal energy storage) tank. Solar energy incident on the ETHPSC is collected and stored in the LHTES tank. The stored heat is then transferred to the domestic hot water supply via a finned heat exchanger pipe placed inside the tank. A combination of mathematical algorithms is used to model a complete process of the heat absorption, storage and release modes of the proposed system. The results show that for a large range of flow rates, the thermal performance of the ETHPSC-LHTES system is higher than that of a similar system without latent heat storage. Furthermore, the analysis shows that the efficiency of the introduced system is less sensitive to the draw off water flowrate than a conventional system. Analysis indicates that this system could be applicable as a complementary part to conventional ETHPSC systems to be able to produce hot water at night time or at times with weak radiation. - Highlights: • The ETHPSC is integrated with PCM at manifold side for night hot water demands. • The thermal performance of the ETHPSC-PCM is often higher than the baseline model. • The efficiency of the proposed model is stable for different flow rates. • Using PCM as thermal storage increases reliability on the performance of the system.

  13. Study of emission process in hot, optically thin plasma: application to solar active regions

    International Nuclear Information System (INIS)

    Steenman-Clark, Lois.

    1983-06-01

    Analysis of soft X-ray got in hot and weak density plasmas, such as those in TOKAMAKS and in solar flares, needs a detailed knowledge of emission processes. In this work are presented spectroscopic diagnostics which can be deduced from such spectra analysis and results are applied to magnesium solar spectrum analysis. An important improvement is brought to collisional calculation corresponding to forbidden line populating. For this line, The relative importance of autoionizing states effect, called also resonance effect is studied [fr

  14. Polycarbonate as an Elasto-Plastic Material Model for Simulation of the Microstructure Hot Imprint Process

    Directory of Open Access Journals (Sweden)

    Rokas Šakalys

    2013-08-01

    Full Text Available The thermal imprint process of polymer micro-patterning is widely applied in areas such as manufacturing of optical parts, solar energy, bio-mechanical devices and chemical chips. Polycarbonate (PC, as an amorphous polymer, is often used in thermoforming processes because of its good replication characteristics. In order to obtain replicas of the best quality, the imprint parameters (e.g., pressure, temperature, time, etc. must be determined. Therefore finite element model of the hot imprint process of lamellar periodical microstructure into PC has been created using COMSOL Multiphysics. The mathematical model of the hot imprint process includes three steps: heating, imprinting and demolding. The material properties of amorphous PC strongly depend on the imprint temperature and loading pressure. Polycarbonate was modelled as an elasto-plastic material, since it was analyzed below the glass transition temperature. The hot imprint model was solved using the heat transfer and the solid stress-strain application modes with thermal contact problem between the mold and polycarbonate. It was used for the evaluation of temperature and stress distributions in the polycarbonate during the hot imprint process. The quality of the replica, by means of lands filling ratio, was determined as well.

  15. Solar heating, cooling, and domestic hot water system installed at Kaw Valley State Bank and Trust Company, Topeka, Kansas. Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-11-01

    The building has approximately 5600 square feet of conditioned space. Solar energy is used for space heating, space cooling, and preheating domestic hot water (DHW). The solar energy system has an array of evacuated tube-type collectors with an area of 1068 square feet. A 50/50 solution of ethylene glycol and water is the transfer medium that delivers solar energy to a tube-in-shell heat exchanger that in turn delivers solar-heated water to a 1100 gallon pressurized hot water storage tank. When solar energy is insufficient to satisfy the space heating and/or cooling demand, a natural gas-fired boiler provides auxiliary energy to the fan coil loops and/or the absorption chillers. Extracts from the site files, specification references, drawings, and installation, operation and maintenance instructions are included.

  16. Solar heating and hot water system installed at Alderson Broaddus College, Philippi, West Virginia

    Science.gov (United States)

    1981-01-01

    Data needed necessary to evaluate the design and operation of a solar energy heating and hot water system installed in a commercial application are presented. The information includes system descriptions, acceptance test data, schematics, as built drawing, problems encountered, all solutions and photographs of the system at various stages of completion.

  17. A Library of ATMO Forward Model Transmission Spectra for Hot Jupiter Exoplanets

    Science.gov (United States)

    Goyal, Jayesh M.; Mayne, Nathan; Sing, David K.; Drummond, Benjamin; Tremblin, Pascal; Amundsen, David S.; Evans, Thomas; Carter, Aarynn L.; Spake, Jessica; Baraffe, Isabelle; hide

    2017-01-01

    We present a grid of forward model transmission spectra, adopting an isothermal temperature-pressure profile, alongside corresponding equilibrium chemical abundances for 117 observationally significant hot exoplanets (equilibrium temperatures of 547-2710 K). This model grid has been developed using a 1D radiative-convective-chemical equilibrium model termed ATMO, with up-to-date high-temperature opacities. We present an interpretation of observations of 10 exoplanets, including best-fitting parameters and X(exp 2) maps. In agreement with previous works, we find a continuum from clear to hazy/cloudy atmospheres for this sample of hot Jupiters. The data for all the 10 planets are consistent with subsolar to solar C/O ratio, 0.005 to 10 times solar metallicity and water rather than methane-dominated infrared spectra. We then explore the range of simulated atmospheric spectra for different exoplanets, based on characteristics such as temperature, metallicity, C/O ratio, haziness and cloudiness. We find a transition value for the metallicity between 10 and 50 times solar, which leads to substantial changes in the transmission spectra. We also find a transition value of C/O ratio, from water to carbon species dominated infrared spectra, as found by previous works, revealing a temperature dependence of this transition point ranging from approximately 0.56 to approximately 1-1.3 for equilibrium temperatures from approximately 900 to approximately 2600 K. We highlight the potential of the spectral features of HCN and C2H2 to constrain the metallicities and C/O ratios of planets, using James Webb Space Telescope (JWST) observations. Finally, our entire grid (approximately 460 000 simulations) is publicly available and can be used directly with the JWST simulator PandExo for planning observations.

  18. A library of ATMO forward model transmission spectra for hot Jupiter exoplanets

    Science.gov (United States)

    Goyal, Jayesh M.; Mayne, Nathan; Sing, David K.; Drummond, Benjamin; Tremblin, Pascal; Amundsen, David S.; Evans, Thomas; Carter, Aarynn L.; Spake, Jessica; Baraffe, Isabelle; Nikolov, Nikolay; Manners, James; Chabrier, Gilles; Hebrard, Eric

    2018-03-01

    We present a grid of forward model transmission spectra, adopting an isothermal temperature-pressure profile, alongside corresponding equilibrium chemical abundances for 117 observationally significant hot exoplanets (equilibrium temperatures of 547-2710 K). This model grid has been developed using a 1D radiative-convective-chemical equilibrium model termed ATMO, with up-to-date high-temperature opacities. We present an interpretation of observations of 10 exoplanets, including best-fitting parameters and χ2 maps. In agreement with previous works, we find a continuum from clear to hazy/cloudy atmospheres for this sample of hot Jupiters. The data for all the 10 planets are consistent with subsolar to solar C/O ratio, 0.005 to 10 times solar metallicity and water rather than methane-dominated infrared spectra. We then explore the range of simulated atmospheric spectra for different exoplanets, based on characteristics such as temperature, metallicity, C/O ratio, haziness and cloudiness. We find a transition value for the metallicity between 10 and 50 times solar, which leads to substantial changes in the transmission spectra. We also find a transition value of C/O ratio, from water to carbon species dominated infrared spectra, as found by previous works, revealing a temperature dependence of this transition point ranging from ˜0.56 to ˜1-1.3 for equilibrium temperatures from ˜900 to ˜2600 K. We highlight the potential of the spectral features of HCN and C2H2 to constrain the metallicities and C/O ratios of planets, using James Webb Space Telescope (JWST) observations. Finally, our entire grid (˜460 000 simulations) is publicly available and can be used directly with the JWST simulator PandExo for planning observations.

  19. 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)

    Avezova, N.R.; Ruziev, O. S.; Suleimanov, Sh. I.; Avezov, R. R.; Vakhidov, A.

    2013-01-01

    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)

  20. Enhancement of stack ventilation in hot and humid climate using a combination of roof solar collector and vertical stack

    Energy Technology Data Exchange (ETDEWEB)

    Yusoff, Wardah Fatimah Mohammad; Salleh, Elias [Department of Architecture, Faculty of Design and Architecture, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Adam, Nor Mariah [Department of Mechanical and Manufacturing Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Sapian, Abdul Razak [Department of Architecture, Kulliyyah of Architecture and Environmental Design, International Islamic University Malaysia, P.O. Box 10, 50728 Kuala Lumpur (Malaysia); Yusof Sulaiman, Mohamad [Solar Energy Research Institute, 3rd Floor, Tun Sri Lanang Library Building, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2010-10-15

    In the hot and humid climate, stack ventilation is inefficient due to small temperature difference between the inside and outside of naturally ventilated buildings. Hence, solar induced ventilation is a feasible alternative in enhancing the stack ventilation. This paper aims to investigate the effectiveness of a proposed solar induced ventilation strategy, which combines a roof solar collector and a vertical stack, in enhancing the stack ventilation performance in the hot and humid climate. The methodology selected for the investigation is physical experimental modelling which was carried out in the actual environment. The results are presented and discussed in terms of two performance variables: air temperature and air velocity. The findings indicate that the proposed strategy is able to enhance the stack ventilation, both in semi-clear sky and overcast sky conditions. The highest air temperature difference between the air inside the stack and the ambient air (T{sub i}-T{sub o}) is achieved in the semi-clear sky condition, which is about 9.9 C (45.8 C-35.9 C). Meanwhile, in the overcast sky condition, the highest air temperature difference (T{sub i}-T{sub o}) is 6.2 C (39.3 C-33.1 C). The experimental results also indicate good agreement with the theoretical results for the glass temperature, the air temperature in the roof solar collector's channel and the absorber temperature. The findings also show that wind has significant effect to the induced air velocity by the proposed strategy. (author)

  1. Search for Solar Axions by the CERN Axion Solar Telescope with 3 He Buffer Gas: Closing the Hot Dark Matter Gap

    CERN Document Server

    Arik, M.; Barth, K.; Belov, A.; Borghi, S.; Bräuninger, H.; Cantatore, G.; Carmona, J.M.; Cetin, S.A.; Collar, J.I.; Da Riva, E.; Dafni, T.; Davenport, M.; Eleftheriadis, C.; Elias, N.; Fanourakis, G.; Ferrer-Ribas, E.; Friedrich, P.; Galán, J.; García, J.A.; Gardikiotis, A.; Garza, J.G.; Gazis, E.N.; Geralis, T.; Georgiopoulou, E.; Giomataris, I.; Gninenko, S.; Gómez, H.; Gómez Marzoa, M.; Gruber, E.; Guthörl, T.; Hartmann, R.; Hauf, S.; Haug, F.; Hasinoff, M.D.; Hoffmann, D.H.H.; Iguaz, F.J.; Irastorza, I.G.; Jacoby, J.; Jakovčić, K.; Karuza, M.; Königsmann, K.; Kotthaus, R.; Krčmar, M.; Kuster, M.; Lakić, B.; Lang, P.M.; Laurent, J.M.; Liolios, A.; Ljubičić, A.; Lozza, V.; Luzón, G.; Neff, S.; Niinikoski, T.; Nordt, A.; Papaevangelou, T.; Pivovaroff, M.J.; Raffelt, G.; Riege, H.; Rodríguez, A.; Rosu, M.; Ruz, J.; Savvidis, I.; Shilon, I.; Silva, P.S.; Solanki, S.K.; Stewart, L.; Tomás, A.; Tsagri, M.; van Bibber, K.; Vafeiadis, T.; Villar, J.; Vogel, J.K.; Yildiz, S.C.; Zioutas, K.

    2014-01-01

    The CERN Axion Solar Telescope (CAST) has finished its search for solar axions with 3^He buffer gas, covering the search range 0.64 eV < m_a <1.17 eV. This closes the gap to the cosmological hot dark matter limit and actually overlaps with it. From the absence of excess X-rays when the magnet was pointing to the Sun we set a typical upper limit on the axion-photon coupling of g_ag < 3.3 x 10^{-10} GeV^{-1} at 95% CL, with the exact value depending on the pressure setting. Future direct solar axion searches will focus on increasing the sensitivity to smaller values of g_a, for example by the currently discussed next generation helioscope IAXO.

  2. Search for Solar Axions by the CERN Axion Solar Telescope with He3 Buffer Gas: Closing the Hot Dark Matter Gap

    Science.gov (United States)

    Arik, M.; Aune, S.; Barth, K.; Belov, A.; Borghi, S.; Bräuninger, H.; Cantatore, G.; Carmona, J. M.; Cetin, S. A.; Collar, J. I.; Da Riva, E.; Dafni, T.; Davenport, M.; Eleftheriadis, C.; Elias, N.; Fanourakis, G.; Ferrer-Ribas, E.; Friedrich, P.; Galán, J.; García, J. A.; Gardikiotis, A.; Garza, J. G.; Gazis, E. N.; Geralis, T.; Georgiopoulou, E.; Giomataris, I.; Gninenko, S.; Gómez, H.; Gómez Marzoa, M.; Gruber, E.; Guthörl, T.; Hartmann, R.; Hauf, S.; Haug, F.; Hasinoff, M. D.; Hoffmann, D. H. H.; Iguaz, F. J.; Irastorza, I. G.; Jacoby, J.; Jakovčić, K.; Karuza, M.; Königsmann, K.; Kotthaus, R.; Krčmar, M.; Kuster, M.; Lakić, B.; Lang, P. M.; Laurent, J. M.; Liolios, A.; Ljubičić, A.; Luzón, G.; Neff, S.; Niinikoski, T.; Nordt, A.; Papaevangelou, T.; Pivovaroff, M. J.; Raffelt, G.; Riege, H.; Rodríguez, A.; Rosu, M.; Ruz, J.; Savvidis, I.; Shilon, I.; Silva, P. S.; Solanki, S. K.; Stewart, L.; Tomás, A.; Tsagri, M.; van Bibber, K.; Vafeiadis, T.; Villar, J.; Vogel, J. K.; Yildiz, S. C.; Zioutas, K.; CAST Collaboration

    2014-03-01

    The CERN Axion Solar Telescope has finished its search for solar axions with He3 buffer gas, covering the search range 0.64 eV≲ma≲1.17 eV. This closes the gap to the cosmological hot dark matter limit and actually overlaps with it. From the absence of excess x rays when the magnet was pointing to the Sun we set a typical upper limit on the axion-photon coupling of gaγ≲3.3×10-10 GeV-1 at 95% C.L., with the exact value depending on the pressure setting. Future direct solar axion searches will focus on increasing the sensitivity to smaller values of gaγ, for example by the currently discussed next generation helioscope International AXion Observatory.

  3. An experimental study of solar desalination using free jets and an auxiliary hot air stream

    Science.gov (United States)

    Eid, Eldesouki I.; Khalaf-Allah, Reda A.; Dahab, Mohamed A.

    2018-04-01

    An experimental study for a solar desalination system based on jet-humidification with an auxiliary perpendicular hot air stream was carried out at Suez city, Egypt 29.9668°N, 32.5498°E. The tests were done from May to October 2016. The effects of nozzles situations and nozzle diameter with and without hot air stream on fresh water productivity were monitored. The results show that; the lateral and downward jets from narrow nozzles have more productivities than other situations. The hot air stream has to be adapted at a certain flow rate to get high values of productivity. The system productivity is (5.6 L/m 2 ), the estimated cost is (0.030063 / L) and the efficiency is 32.8%.

  4. Solar heating and hot water system installed at Municipal Building complex, Abbeville, South Carolina

    Science.gov (United States)

    1979-01-01

    Information on the solar energy system installed at the new municipal building for the City of Abbeville, SC is presented, including a description of solar energy system and buildings, lessons learned, and recommendations. The solar space heating system is a direct air heating system. The flat roof collector panel was sized to provide 75% of the heating requirement based on an average day in January. The collectors used are job-built with two layers of filon corrugated fiberglass FRP panels cross lapped make up the cover. The storage consists of a pit filled with washed 3/4 in - 1 1/2 in diameter crushed granite stone. The air handler includes the air handling mechanism, motorized dampers, air circulating blower, sensors, control relays and mode control unit. Solar heating of water is provided only those times when the hot air in the collector is exhausted to the outside.

  5. Search for solar axions by the CERN axion solar telescope with 3He buffer gas: closing the hot dark matter gap.

    Science.gov (United States)

    Arik, M; Aune, S; Barth, K; Belov, A; Borghi, S; Bräuninger, H; Cantatore, G; Carmona, J M; Cetin, S A; Collar, J I; Da Riva, E; Dafni, T; Davenport, M; Eleftheriadis, C; Elias, N; Fanourakis, G; Ferrer-Ribas, E; Friedrich, P; Galán, J; García, J A; Gardikiotis, A; Garza, J G; Gazis, E N; Geralis, T; Georgiopoulou, E; Giomataris, I; Gninenko, S; Gómez, H; Gómez Marzoa, M; Gruber, E; Guthörl, T; Hartmann, R; Hauf, S; Haug, F; Hasinoff, M D; Hoffmann, D H H; Iguaz, F J; Irastorza, I G; Jacoby, J; Jakovčić, K; Karuza, M; Königsmann, K; Kotthaus, R; Krčmar, M; Kuster, M; Lakić, B; Lang, P M; Laurent, J M; Liolios, A; Ljubičić, A; Luzón, G; Neff, S; Niinikoski, T; Nordt, A; Papaevangelou, T; Pivovaroff, M J; Raffelt, G; Riege, H; Rodríguez, A; Rosu, M; Ruz, J; Savvidis, I; Shilon, I; Silva, P S; Solanki, S K; Stewart, L; Tomás, A; Tsagri, M; van Bibber, K; Vafeiadis, T; Villar, J; Vogel, J K; Yildiz, S C; Zioutas, K

    2014-03-07

    The CERN Axion Solar Telescope has finished its search for solar axions with (3)He buffer gas, covering the search range 0.64 eV ≲ ma ≲ 1.17 eV. This closes the gap to the cosmological hot dark matter limit and actually overlaps with it. From the absence of excess x rays when the magnet was pointing to the Sun we set a typical upper limit on the axion-photon coupling of gaγ ≲ 3.3 × 10(-10)  GeV(-1) at 95% C.L., with the exact value depending on the pressure setting. Future direct solar axion searches will focus on increasing the sensitivity to smaller values of gaγ, for example by the currently discussed next generation helioscope International AXion Observatory.

  6. Solar Hot Air Balloons: A Low Cost, Multi-hour Flight System for Lightweight Scientific Instrumentation Packages

    Science.gov (United States)

    Bowman, D. C.; Albert, S.; Dexheimer, D.; Murphy, S.; Mullen, M.

    2017-12-01

    Existing scientific ballooning solutions for multi hour flights in the upper troposphere/lower stratosphere are expensive and/or technically challenging. In contrast, solar hot air balloons are inexpensive and simple to construct. These balloons, which rely solely on sunlight striking a darkened envelope, can deliver payloads to 22 km altitude and maintain level flight until sunset. We describe an experimental campaign in which five solar hot air balloons launched in 45 minutes created a free flying infrasound (low frequency sound) microphone network that remained in the air for over 12 hours. We discuss the balloons' trajectory, maximum altitude, and stability as well as present results from the infrasound observations. We assess the performance and limitations of this design for lightweight atmospheric instrumentation deployments that require multi-hour flight times. Finally, we address the possibilities of multi day flights during the polar summer and on other planets.

  7. Computational Fluid Dynamics Model for Solar Thermal Storage Tanks with Helical Jacket Heater and Upper Spiral Coil Heater

    Energy Technology Data Exchange (ETDEWEB)

    Baek, Seung Man [Seoul Nat' l Univ., Seoul (Korea, Republic of); Zhong, Yiming; Nam, Jin Hyun [Daegu Univ., Daegu (Korea, Republic of); Chung, Jae Dong [Sejong Univ., Seoul (Korea, Republic of); Hong, Hiki [Kyung Hee Univ., Seoul (Korea, Republic of)

    2013-04-15

    In a solar domestic hot water (Shadow) system, solar energy is collected using collector panels, transferred to a circulating heat transfer fluid (brine), and eventually stored in a thermal storage tank (Test) as hot water. In this study, a computational fluid dynamics (CAD) model was developed to predict the solar thermal energy storage in a hybrid type Test equipped with a helical jacket heater (mantle heat exchanger) and an immersed spiral coil heater. The helical jacket heater, which is the brine flow path attached to the side wall of a Test, has advantages including simple system design, low brine flow rate, and enhanced thermal stratification. In addition, the spiral coil heater further enhances the thermal performance and thermal stratification of the Test. The developed model was validated by the good agreement between the CAD results and the experimental results performed with the hybrid-type Test in Shadow settings.

  8. Computational Fluid Dynamics Model for Solar Thermal Storage Tanks with Helical Jacket Heater and Upper Spiral Coil Heater

    International Nuclear Information System (INIS)

    Baek, Seung Man; Zhong, Yiming; Nam, Jin Hyun; Chung, Jae Dong; Hong, Hiki

    2013-01-01

    In a solar domestic hot water (Shadow) system, solar energy is collected using collector panels, transferred to a circulating heat transfer fluid (brine), and eventually stored in a thermal storage tank (Test) as hot water. In this study, a computational fluid dynamics (CAD) model was developed to predict the solar thermal energy storage in a hybrid type Test equipped with a helical jacket heater (mantle heat exchanger) and an immersed spiral coil heater. The helical jacket heater, which is the brine flow path attached to the side wall of a Test, has advantages including simple system design, low brine flow rate, and enhanced thermal stratification. In addition, the spiral coil heater further enhances the thermal performance and thermal stratification of the Test. The developed model was validated by the good agreement between the CAD results and the experimental results performed with the hybrid-type Test in Shadow settings

  9. Solar Drying in Hot and Dry Climate of Jaipur

    OpenAIRE

    Parikh, Darshit; Agrawal, G. D.

    2016-01-01

    Objective of the present study was to design, develop and to carry out detail experimentation and then analyze solar cabinet dryer. For these various types of solar dryer, their principles and design methods, modeling, drying temperature, efficiency, utilization of dryer and payback period were reviewed. In the present study, solar cabinet dryer is constructed at Mechanical Engineering Department, M.N.I.T, Jaipur, latitude (26.01° N). The measurement of solar intensity, temperatures, relative...

  10. Energetical and ecological assessment of solar- and heat pump technologies for hot water preparation and space heating in Austria

    International Nuclear Information System (INIS)

    Faninger, G.

    1991-11-01

    Solar and heat pump systems have been proved in many applications on the market. To achieve an efficient energy output it is necessary to consider the special conditions of these technologies. The energetical and ecological criteria of solar and heat pump systems for hot water preparation and space heating are analysed on the basis of experimental data. (author)

  11. Solar Technology Curriculum, 1980.

    Science.gov (United States)

    Seward County Community Coll., Liberal, KS.

    This curriculum guide contains lecture outlines and handouts for training solar technicians in the installation, maintenance, and repair of solar energy hot water and space heating systems. The curriculum consists of four modular units developed to provide a model through which community colleges and area vocational/technical schools can respond…

  12. System design package for IBM system one: solar heating and domestic hot water

    Science.gov (United States)

    1977-01-01

    This report is a collation of documents and drawings that describe a prototype solar heating and hot water system using air as the collector fluid and a pebble bed for heat storage. The system was designed for installation into a single family dwelling. The description, performance specification, subsystem drawings, verification plan/procedure, and hazard analysis of the system was packaged for evaluation of the system with information sufficient to assemble a similar system.

  13. The effect of side-chain substitution and hot processing on diketopyrrolopyrrole-based polymers for organic solar cells

    NARCIS (Netherlands)

    Heintges, G.H.L.; Leenaers, P.J.; Janssen, R.A.J.

    2017-01-01

    The effects of cold and hot processing on the performance of polymer-fullerene solar cells are investigated for diketopyrrolopyrrole (DPP) based polymers that were specifically designed and synthesized to exhibit a strong temperature-dependent aggregation in solution. The polymers, consisting of

  14. Solar Power Potential of Tanzania: Identifying CSP and PV Hot Spots through a GIS Multicriteria Decision Making Analysis

    DEFF Research Database (Denmark)

    Aly, Ahmed; Jensen, Steen Solvang; Pedersen, Anders Branth

    2017-01-01

    More than one billion people are still living without access to electricity today. More than half of them are living in Sub-Saharan Africa. There is a noticeable shortage of energy related information in Africa, especially for renewable energies. Due to lacking studies and researches on integrating...... renewable energy technologies, the Tanzanian official generation expansion plan till 2035 showed high dependency on fossil fuel and a negligible role of renewables other than large hydropower. This study investigates the spatial suitability for large-scale solar power installations in Tanzania through using...... technology-specific suitability map categorizes all the non-excluded areas into most suitable, suitable, moderately suitable, and least suitable areas. The study also suggests four hot spots (i.e. specific recommended locations) for Concentrated Solar Power (CSP) installations and four hot spots...

  15. Looking beyond installation: Why households struggle to make the most of solar hot water systems

    International Nuclear Information System (INIS)

    Gill, Nicholas; Osman, Peter; Head, Lesley; Voyer, Michelle; Harada, Theresa; Waitt, Gordon; Gibson, Chris

    2015-01-01

    This paper examines household responses to sustainability issues and adoption of energy saving technologies. Our example of solar hot water systems highlights the complexity and variability of responses to low-carbon technologies. While SHW systems have the potential to provide the majority of household hot water and to lower carbon emissions, little research has been done to investigate how SHW systems are integrated into everyday life. We draw on cultural understandings of the household to identify passive and active users of SHW systems and utilize a model that illustrates how technology use is dependent on inter-relations between cultural norms, systems of provision, the material elements of homes, and practice. A key finding is that households can be ill-prepared to make the most of their SHW systems and lack post-installation support to do so. Thus, informed and efficient use of SHW systems is hit and miss. Current policy is largely aimed at subsidizing purchase and installation on the assumption that this is sufficient for emission reduction goals. Our analysis provides evidence to the contrary. Areas we highlight for policy and practice improvement are independent pre-purchase advice, installation quality, and practical guidance on system operation and interaction with patterns of hot water use. - Highlights: • We interview Australian households about their experience with SHW systems. • We identify active and passive users of SHW. Active users tend to be dissatisfied with their system. • Passive users tend to be satisfied but have relatively inefficient systems. • Householders struggle to integrate hot water use and system operation, compromising efficiency. • Policy should encompass pre and post-installation support as much as incentives to install.

  16. THE ATMOSPHERIC CIRCULATION OF THE HOT JUPITER WASP-43b: COMPARING THREE-DIMENSIONAL MODELS TO SPECTROPHOTOMETRIC DATA

    Energy Technology Data Exchange (ETDEWEB)

    Kataria, Tiffany; Showman, Adam P. [Department of Planetary Sciences and Lunar and Planetary Laboratory, The University of Arizona, Tucson, AZ 85721 (United States); Fortney, Jonathan J.; Line, Michael R. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Stevenson, Kevin B.; Kreidberg, Laura; Bean, Jacob L. [Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States); Désert, Jean-Michel, E-mail: tkataria@astro.ex.ac.uk [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80309 (United States)

    2015-03-10

    The hot Jupiter WASP-43b (2 M{sub J}, 1 R{sub J}, T {sub orb} = 19.5 hr) has now joined the ranks of transiting hot Jupiters HD 189733b and HD 209458b as an exoplanet with a large array of observational constraints. Because WASP-43b receives a similar stellar flux as HD 209458b but has a rotation rate four times faster and a higher gravity, studying WASP-43b probes the effect of rotation rate and gravity on the circulation when stellar irradiation is held approximately constant. Here we present three-dimensional (3D) atmospheric circulation models of WASP-43b, exploring the effects of composition, metallicity, and frictional drag. We find that the circulation regime of WASP-43b is not unlike other hot Jupiters, with equatorial superrotation that yields an eastward-shifted hotspot and large day-night temperature variations (∼600 K at photospheric pressures). We then compare our model results to Hubble Space Telescope (HST)/WFC3 spectrophotometric phase curve measurements of WASP-43b from 1.12 to 1.65 μm. Our results show the 5× solar model light curve provides a good match to the data, with a peak flux phase offset and planet/star flux ratio that is similar to observations; however, the model nightside appears to be brighter. Nevertheless, our 5× solar model provides an excellent match to the WFC3 dayside emission spectrum. This is a major success, as the result is a natural outcome of the 3D dynamics with no model tuning. These results demonstrate that 3D circulation models can help interpret exoplanet atmospheric observations, even at high resolution, and highlight the potential for future observations with HST, James Webb Space Telescope, and other next-generation telescopes.

  17. Hot-compress: A new postdeposition treatment for ZnO-based flexible dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Haque Choudhury, Mohammad Shamimul, E-mail: shamimul129@gmail.com [Department of Frontier Material, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, Aichi 466-8555 (Japan); Department of Electrical and Electronic Engineering, International Islamic University Chittagong, b154/a, College Road, Chittagong 4203 (Bangladesh); Kishi, Naoki; Soga, Tetsuo [Department of Frontier Material, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, Aichi 466-8555 (Japan)

    2016-08-15

    Highlights: • A new postdeposition treatment named hot-compress is introduced. • Hot-compression gives homogeneous compact layer ZnO photoanode. • I-V and EIS analysis data confirms the efficacy of this method. • Charge transport resistance was reduced by the application of hot-compression. - Abstract: This article introduces a new postdeposition treatment named hot-compress for flexible zinc oxide–base dye-sensitized solar cells. This postdeposition treatment includes the application of compression pressure at an elevated temperature. The optimum compression pressure of 130 Ma at an optimum compression temperature of 70 °C heating gives better photovoltaic performance compared to the conventional cells. The aptness of this method was confirmed by investigating scanning electron microscopy image, X-ray diffraction, current-voltage and electrochemical impedance spectroscopy analysis of the prepared cells. Proper heating during compression lowers the charge transport resistance, longer the electron lifetime of the device. As a result, the overall power conversion efficiency of the device was improved about 45% compared to the conventional room temperature compressed cell.

  18. Temperature distribution of a hot water storage tank in a simulated solar heating and cooling system

    Science.gov (United States)

    Namkoong, D.

    1976-01-01

    A 2,300-liter hot water storage tank was studied under conditions simulating a solar heating and cooling system. The initial condition of the tank, ranging from 37 C at the bottom to 94 C at the top, represented a condition midway through the start-up period of the system. During the five-day test period, the water in the tank gradually rose in temperature but in a manner that diminished its temperature stratification. Stratification was found not to be an important factor in the operation of the particular solar system studied.

  19. Slow hot carrier cooling in cesium lead iodide perovskites

    Science.gov (United States)

    Shen, Qing; Ripolles, Teresa S.; Even, Jacky; Ogomi, Yuhei; Nishinaka, Koji; Izuishi, Takuya; Nakazawa, Naoki; Zhang, Yaohong; Ding, Chao; Liu, Feng; Toyoda, Taro; Yoshino, Kenji; Minemoto, Takashi; Katayama, Kenji; Hayase, Shuzi

    2017-10-01

    Lead halide perovskites are attracting a great deal of interest for optoelectronic applications such as solar cells, LEDs, and lasers because of their unique properties. In solar cells, heat dissipation by hot carriers results in a major energy loss channel responsible for the Shockley-Queisser efficiency limit. Hot carrier solar cells offer the possibility to overcome this limit and achieve energy conversion efficiency as high as 66% by extracting hot carriers. Therefore, fundamental studies on hot carrier relaxation dynamics in lead halide perovskites are important. Here, we elucidated the hot carrier cooling dynamics in all-inorganic cesium lead iodide (CsPbI3) perovskite using transient absorption spectroscopy. We observe that the hot carrier cooling rate in CsPbI3 decreases as the fluence of the pump light increases and the cooling is as slow as a few 10 ps when the photoexcited carrier density is 7 × 1018 cm-3, which is attributed to phonon bottleneck for high photoexcited carrier densities. Our findings suggest that CsPbI3 has a potential for hot carrier solar cell applications.

  20. Energy Savings for Solar Heating Systems

    DEFF Research Database (Denmark)

    Thür, Alexander; Furbo, Simon; Shah, Louise Jivan

    2006-01-01

    showed a good degree of similarity. With the boiler model, various simulations of solar domestic hot water heating systems were done for different hot water demands and collector sizes. The result shows that the potential of fuel reduction can be much higher than the solar gain of the solar thermal...... system. For some conditions the fuel reduction can be up to the double of the solar gain due to a strong increase of the system efficiency. As the monitored boilers were not older than 3 years, it can be assumed that the saving potential with older boilers could be even higher than calculated......In this paper the realistic behaviour and efficiency of heating systems were analysed, based on long term monitoring projects. Based on the measurements a boiler model used to calculate the boiler efficiency on a monthly basis was evaluated. Comparisons of measured and calculated fuel consumptions...

  1. Thermal performance of small solar domestic hot water systems in theory, in the laboratory and in practice

    DEFF Research Database (Denmark)

    Andersen, Elsa

    1998-01-01

    for poor thermal performances of systems tested in practice are given. Based on theoretical calculations the negative impact on the thermal performance, due to a large number of different parameter variations are given. Recommendations for future developments of small solar domestic hot water systems...

  2. A solar neutrino loophole: standard solar models

    Energy Technology Data Exchange (ETDEWEB)

    Rouse, C A [General Atomic Co., San Diego, Calif. (USA)

    1975-11-01

    The salient aspects of the existence theorem for a unique solution to a system of linear of nonlinear first-order, ordinary differential equations are given and applied to the equilibrium stellar structure equations. It is shown that values of pressure, temperature, mass and luminosity are needed at one point - and for the sun, the logical point is the solar radius. It is concluded that since standard solar model calculations use split boundary conditions, a solar neutrino loophole still remains: solar model calculations that seek to satisfy the necessary condition for a unique solution to the solar structure equations suggest a solar interior quite different from that deduced in standard models. This, in turn, suggests a theory of formation and solar evolution significantly different from the standard theory.

  3. Lead Acetate Based Hybrid Perovskite Through Hot Casting for Planar Heterojunction Solar Cells

    Science.gov (United States)

    Shin, Gwang Su; Choi, Won-Gyu; Na, Sungjae; Gökdemir, Fatma Pinar; Moon, Taeho

    2018-03-01

    Flawless coverage of a perovskite layer is essential in order to achieve realistic high-performance planar heterojunction solar cells. We present that high-quality perovskite layers can be efficiently formed by a novel hot casting route combined with MAI (CH3NH3I) and non-halide lead acetate (PbAc2) precursors under ambient atmosphere. Casting temperature is controlled to produce various perovskite microstructures and the resulted crystalline layers are found to be comprised of closely packed islands with a smooth surface structure. Lead acetate employed perovskite solar cells are fabricated using PEDOT:PSS and PCBM charge transporting layers, in p- i- n type planar architecture. Especially, the outstanding open-circuit voltage demonstrates the high crystallinity and dense coverage of the produced perovskite layers by this facile route.

  4. Prediction and experimental validation of stagnation temperature attained by a solar cooker of hot box type

    Energy Technology Data Exchange (ETDEWEB)

    Narasimha Rao, A. V; Srikrishna, D. V. N [Warangal (India)

    2000-07-01

    A hot box type solar cooker, having double glass covers and a plane mirror reflector, is tested for stagnation temperature. A computer code is developed based on the analytical model proposed by Vaishya et. al. The global and beam components of solar radiation measured at Warangal are made use to predict the stagnation temperature of the cooker. The observed values of stagnation temperature at Warangal are compared with those of predicted values. A good agreement of the measured and observed values of the stagnation temperature is observed during the afternoon period. The lag in the observed values during the forenoon may be due to thermal inertia of the cooker. [Spanish] Se probo una estufa solar de tipo caja caliente con cubiertas dobles de vidrio y un espejo reflector plano para medir la temperatura de estancamiento. Se desarrollo un codigo de computacion basado en el modelo analitico propuesto por Vaishya et. al. Los componentes de la radiacion solar globales y de rayo medidos en Warangal se usan para predecir la temperatura de estancamiento de la estufa. Los valores observados de la temperatura de estancamiento en Warangal se comparan con los valores predichos. Se aprecia una buena concidencia de los valores medidos y observados de la temperatura de estancamiento durante el periodo de la tarde. El retraso de los valores observados durante la manana puede ser debido a la inercia termica de la estufa.

  5. ON THE RELATIONSHIP BETWEEN A HOT-CHANNEL-LIKE SOLAR MAGNETIC FLUX ROPE AND ITS EMBEDDED PROMINENCE

    International Nuclear Information System (INIS)

    Cheng, X.; Ding, M. D.; Zhang, J.; Guo, Y.; Chen, P. F.; Sun, J. Q.; Srivastava, A. K.

    2014-01-01

    A magnetic flux rope (MFR) is a coherent and helical magnetic field structure that has recently been found likely to appear as an elongated hot channel prior to a solar eruption. In this Letter, we investigate the relationship between the hot channel and the associated prominence through analysis of a limb event on 2011 September 12. In the early rise phase, the hot channel was initially cospatial with the prominence. It then quickly expanded, resulting in a separation of the top of the hot channel from that of the prominence. Meanwhile, they both experienced an instantaneous morphology transformation from a Λ shape to a reversed-Y shape and the top of these two structures showed an exponential increase in height. These features are a good indication of the occurrence of kink instability. Moreover, the onset of kink instability is found to coincide in time with the impulsive enhancement of flare emission underneath the hot channel, suggesting that ideal kink instability likely also plays an important role in triggering fast flare reconnection besides initiating the impulsive acceleration of the hot channel and distorting its morphology. We conclude that the hot channel is most likely the MFR system and the prominence only corresponds to the cool materials that are collected in the bottom of the helical field lines of the MFR against gravity

  6. The impact of silicon solar cell architecture and cell interconnection on energy yield in hot & sunny climates

    KAUST Repository

    Haschke, Jan

    2017-03-23

    Extensive knowledge of the dependence of solar cell and module performance on temperature and irradiance is essential for their optimal application in the field. Here we study such dependencies in the most common high-efficiency silicon solar cell architectures, including so-called Aluminum back-surface-field (BSF), passivated emitter and rear cell (PERC), passivated emitter rear totally diffused (PERT), and silicon heterojunction (SHJ) solar cells. We compare measured temperature coefficients (TC) of the different electrical parameters with values collected from commercial module data sheets. While similar TC values of the open-circuit voltage and the short circuit current density are obtained for cells and modules of a given technology, we systematically find that the TC under maximum power-point (MPP) conditions is lower in the modules. We attribute this discrepancy to additional series resistance in the modules from solar cell interconnections. This detrimental effect can be reduced by using a cell design that exhibits a high characteristic load resistance (defined by its voltage-over-current ratio at MPP), such as the SHJ architecture. We calculate the energy yield for moderate and hot climate conditions for each cell architecture, taking into account ohmic cell-to-module losses caused by cell interconnections. Our calculations allow us to conclude that maximizing energy production in hot and sunny environments requires not only a high open-circuit voltage, but also a minimal series-to-load-resistance ratio.

  7. System Design Package for SIMS Prototype System 3, Solar Heating and Domestic Hot Water

    Science.gov (United States)

    1978-01-01

    A collation of documents and drawings are presented that describe a prototype solar heating and hot water system using liquid flat plate collectors and a gas or electric furnace energy subsystem. The system was designed for installation into a single-family dwelling. The description, performance specification, subsystem drawings, verification plan/procedure, and hazard analysis of the system are packaged for evaluation of the system with information sufficient to assemble a similar system.

  8. Collective plasma effects associated with the continuous injection model of solar flare particle streams

    International Nuclear Information System (INIS)

    Vlahos, L.; Paradopoulos, K.

    1979-01-01

    A modified continous injection model for impulsive solar flares that includes self-consistently plasma nonlinearities based on the concept of marginal stability is presented. A quasi-stationary state is established, composed of a hot truncated electron Maxwellian distribution confined by acoustic turbulence on the top of the loop and energetic electron beams precipitating in the chromosphere. It is shown that the radiation properties of the models are in accordance with observations

  9. Collective plasma effects associated with the continuous injection model of solar flare particle streams

    Science.gov (United States)

    Vlahos, L.; Papadopoulos, K.

    1979-01-01

    A modified continuous injection model for impulsive solar flares that includes self-consistent plasma nonlinearities based on the concept of marginal stability is presented. A quasi-stationary state is established, composed of a hot truncated electron Maxwellian distribution confined by acoustic turbulence on the top of the loop and energetic electron beams precipitating in the chromosphere. It is shown that the radiation properties of the model are in accordance with observations.

  10. Comparison between a new TRNSYS model and experimental data of phase change materials in a solar combisystem

    Energy Technology Data Exchange (ETDEWEB)

    Bony, J.; Citherlet, S.

    2007-07-01

    In the framework of the IEA Task 32 (Solar Heating and Cooling Programme), we developed a numeric model to simulate heat transfer in phase change materials (PCM), and experimental data. The analyzed system is bulk PCM plunged in a water tank storage of a solar combisystem (heating and domestic hot water production). The numerical model, based on the enthalpy approach, takes into account hysteresis and subcooling characteristic and also the conduction and the convection in the PCM. This model has been implemented in an existing TRNSYS type of water tank storage. The simulations has been compared with experimental data obtained with a solar installation using water tank storage of about 900 litres, already studied during the IEA Task 26 (Weiss 2003). (author)

  11. Smart solar domestic hot water systems. Development and test; Intelligente solvarmeanlaeg. Udvikling og afproevning

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, E.; Knudsen, S.; Furbo, S.; Vejen, N.K.

    2001-07-01

    The purpose of the project described in this report is to develop and test smart solar domestic hot water systems (SDHW systems) where the energy supply from the auxiliary energy supply system is controlled in a flexible way fitted to the hot water consumption in such a way, that the SDHW systems are suitable for large as well as small hot water demands. In a smart SDHW system the auxiliary energy supply system is controlled in a smart way. The auxiliary energy supply system heats up the water in the hot water tank from the top and only the hot water volume needed by the consumers is heated. Further the water is heated immediately before tapping. The control system includes a number of temperature sensors which cover the temperatures in the auxiliary heated volume. Based on these temperatures the energy content in the hot water tank is calculated. Only water heated to a temperature above 50 deg. C contributes to the total energy content in the hot water tank. Furhter the control system includes a timer that only allows the auxiliary energy supply system to be active in certain time periods and only if the energy content in the hot water tank is lower than wanted. In this way the water in the tank is heated immediately before the expected time of tapping and only the hot water volume needed is heated. The report is divided into five main sections. The sections deals with: Developing and testing storage tanks, laboratory test of SDHW systems based on some of the developed storage tanks, validation of simulation programs for smart solar heating systems, optimisation of system design and control strategy and measurements on two smart SDHW systems installed in single family houses. In all the developed hot water tanks, attempt is made to heat the water in the tank from the top of the tank and not as in traditional tanks where the water is heated from the lowest level of the auxiliary energy supply system, normally a helix or a electrical heating element placed in the

  12. Utilizing hot electrons

    Energy Technology Data Exchange (ETDEWEB)

    Nozik, Arthur J.

    2018-03-01

    In current solar cells, any photon energy exceeding the semiconductor bandgap is lost before being collected, limiting the cell performance. Hot carrier solar cells could avoid these losses. Now, a detailed experimental study and analysis shows that this strategy could lead to an improvement of the photoconversion efficiency in practice.

  13. Golden Rays - July 2017 | Solar Research | Solar Research | NREL

    Science.gov (United States)

    , subscribe to the Solar Newsletter. SUBSCRIBE Hot Topics Two solar installers secure solar panels on the roof that has the potential to improve the efficiency of solar panels while leveraging existing

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

    Science.gov (United States)

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

    2013-07-01

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

  15. Modeling and optimization of a concentrated solar supercritical CO2 power plant

    Science.gov (United States)

    Osorio, Julian D.

    Renewable energy sources are fundamental alternatives to supply the rising energy demand in the world and to reduce or replace fossil fuel technologies. In order to make renewable-based technologies suitable for commercial and industrial applications, two main challenges need to be solved: the design and manufacture of highly efficient devices and reliable systems to operate under intermittent energy supply conditions. In particular, power generation technologies based on solar energy are one of the most promising alternatives to supply the world energy demand and reduce the dependence on fossil fuel technologies. In this dissertation, the dynamic behavior of a Concentrated Solar Power (CSP) supercritical CO2 cycle is studied under different seasonal conditions. The system analyzed is composed of a central receiver, hot and cold thermal energy storage units, a heat exchanger, a recuperator, and multi-stage compression-expansion subsystems with intercoolers and reheaters between compressors and turbines respectively. The effects of operating and design parameters on the system performance are analyzed. Some of these parameters are the mass flow rate, intermediate pressures, number of compression-expansion stages, heat exchangers' effectiveness, multi-tank thermal energy storage, overall heat transfer coefficient between the solar receiver and the environment and the effective area of the recuperator. Energy and exergy models for each component of the system are developed to optimize operating parameters in order to lead to maximum efficiency. From the exergy analysis, the components with high contribution to exergy destruction were identified. These components, which represent an important potential of improvement, are the recuperator, the hot thermal energy storage tank and the solar receiver. Two complementary alternatives to improve the efficiency of concentrated solar thermal systems are proposed in this dissertation: the optimization of the system's operating

  16. Final report : testing and evaluation for solar hot water reliability.

    Energy Technology Data Exchange (ETDEWEB)

    Caudell, Thomas P. (University of New Mexico, Albuquerque, NM); He, Hongbo (University of New Mexico, Albuquerque, NM); Menicucci, David F. (Building Specialists, Inc., Albuquerque, NM); Mammoli, Andrea A. (University of New Mexico, Albuquerque, NM); Burch, Jay (National Renewable Energy Laboratory, Golden CO)

    2011-07-01

    Solar hot water (SHW) systems are being installed by the thousands. Tax credits and utility rebate programs are spurring this burgeoning market. However, the reliability of these systems is virtually unknown. Recent work by Sandia National Laboratories (SNL) has shown that few data exist to quantify the mean time to failure of these systems. However, there is keen interest in developing new techniques to measure SHW reliability, particularly among utilities that use ratepayer money to pay the rebates. This document reports on an effort to develop and test new, simplified techniques to directly measure the state of health of fielded SHW systems. One approach was developed by the National Renewable Energy Laboratory (NREL) and is based on the idea that the performance of the solar storage tank can reliably indicate the operational status of the SHW systems. Another approach, developed by the University of New Mexico (UNM), uses adaptive resonance theory, a type of neural network, to detect and predict failures. This method uses the same sensors that are normally used to control the SHW system. The NREL method uses two additional temperature sensors on the solar tank. The theories, development, application, and testing of both methods are described in the report. Testing was performed on the SHW Reliability Testbed at UNM, a highly instrumented SHW system developed jointly by SNL and UNM. The two methods were tested against a number of simulated failures. The results show that both methods show promise for inclusion in conventional SHW controllers, giving them advanced capability in detecting and predicting component failures.

  17. NO THERMAL INVERSION AND A SOLAR WATER ABUNDANCE FOR THE HOT JUPITER HD 209458B FROM HST /WFC3 SPECTROSCOPY

    Energy Technology Data Exchange (ETDEWEB)

    Line, Michael R. [NASA Ames Research Center, Moffet Field, CA 94035 (United States); Stevenson, Kevin B.; Bean, Jacob; Kreidberg, Laura [Department of Astronomy and Astrophysics, University of Chicago, 5640 S Ellis Avenue, Chicago, IL 60637 (United States); Desert, Jean-Michel [University of Amsterdam (Netherlands); Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States); Madhusudhan, Nikku [Institute of Astronomy, University of Cambridge, Cambridge CB3 0HA (United Kingdom); Showman, Adam P. [Department of Planetary Sciences and Lunar and Planetary Laboratory, University of Arizona, 1629 E. University Blvd., Tucson, AZ 85721 (United States); Diamond-Lowe, Hannah [Department of Astronomy, Harvard Smithsonian Center for Astrophysics, 60 Garden Street, MS-10, Cambridge, MA 02138 (United States)

    2016-12-01

    The nature of the thermal structure of hot Jupiter atmospheres is one of the key questions raised by the characterization of transiting exoplanets over the past decade. There have been claims that many hot Jupiters exhibit atmospheric thermal inversions. However, these claims have been based on broadband photometry rather than the unambiguous identification of emission features with spectroscopy, and the chemical species that could cause the thermal inversions by absorbing stellar irradiation at high altitudes have not been identified despite extensive theoretical and observational effort. Here we present high-precision Hubble Space Telescope WFC3 observations of the dayside thermal emission spectrum of the hot Jupiter HD 209458b, which was the first exoplanet suggested to have a thermal inversion. In contrast to previous results for this planet, our observations detect water in absorption at 6.2 σ confidence. When combined with Spitzer photometry, the data are indicative of a monotonically decreasing temperature with pressure over the range of 1–0.001 bars at 7.7 σ confidence. We test the robustness of our results by exploring a variety of model assumptions, including the temperature profile parameterization, presence of a cloud, and choice of Spitzer data reduction. We also introduce a new analysis method to determine the elemental abundances from the spectrally retrieved mixing ratios with thermochemical self-consistency and find plausible abundances consistent with solar metallicity (0.06–10 × solar) and carbon-to-oxygen ratios less than unity. This work suggests that high-precision spectrophotometric results are required to robustly infer thermal structures and compositions of extrasolar planet atmospheres and to perform comparative exoplanetology.

  18. The Potential of Heat Collection from Solar Radiation in Asphalt Solar Collectors in Malaysia

    Science.gov (United States)

    Beddu, Salmia; Talib, Siti Hidayah Abdul; Itam, Zarina

    2016-03-01

    The implementation of asphalt solar collectors as a means of an energy source is being widely studied in recent years. Asphalt pavements are exposed to daily solar radiation, and are capable of reaching up to 70°C in temperature. The potential of harvesting energy from solar pavements as an alternative energy source in replace of non-renewable energy sources prone to depletion such as fuel is promising. In Malaysia, the sun intensity is quite high and for this reason, absorbing the heat from sun radiation, and then utilizing it in many other applications such as generating electricity could definitely be impressive. Previous researches on the different methods of studying the effect of heat absorption caused by solar radiation prove to be quite old and inaffective. More recent findings, on the otherhand, prove to be more informative. This paper focuses on determining the potential of heat collection from solar radiation in asphalt solar collectors using steel piping. The asphalt solar collector model constructed for this research was prepared in the civil engineering laboratory. The hot mixed asphalt (HMA) contains 10% bitumen mixed with 90% aggregates of the total size of asphalt. Three stainless steel pipes were embedded into the interior region of the model according to the design criteria, and then put to test. Results show that harvesting energy from asphalt solar collectors proves highly potential in Malaysia due its the hot climate.

  19. Life cycle assessment of domestic heat pump hot water systems in Australia

    Directory of Open Access Journals (Sweden)

    Moore Andrew D.

    2017-01-01

    Full Text Available Water heating accounts for 23% of residential energy consumption in Australia, and, as over half is provided by electric water heaters, is a significant source of greenhouse gas emissions. Due to inclusion in rebate schemes heat pump water heating systems are becoming increasingly popular, but do they result in lower greenhouse gas emissions? This study follows on from a previous life cycle assessment study of domestic hot water systems to include heat pump systems. The streamlined life cycle assessment approach used focused on the use phase of the life cycle, which was found in the previous study to be where the majority of global warming potential (GWP impacts occurred. Data was collected from an Australian heat pump manufacturer and was modelled assuming installation within Australian climate zone 3 (AS/NZS 4234:2011. Several scenarios were investigated for the heat pumps including different sources of electricity (grid, photovoltaic solar modules, and batteries and the use of solar thermal panels. It was found that due to their higher efficiency heat pump hot water systems can result in significantly lower GWP than electric storage hot water systems. Further, solar thermal heat pump systems can have lower GWP than solar electric hot water systems that use conventional electric boosting. Additionally, the contributions of HFC refrigerants to GWP can be significant so the use of alternative refrigerants is recommended. Heat pumps combined with PV and battery technology can achieve the lowest GWP of all domestic hot water systems.

  20. Material cycling solar system modeled ecosystem; Seitaikei wo model to shita busshitsu junkangata solar system

    Energy Technology Data Exchange (ETDEWEB)

    Sato, M [Hachinohe Institute of Technology, Aomori (Japan)

    1996-10-27

    It is proposed to establish an integrated system close to a natural ecosystem for an industrial complex, taking that in Hachinohe City, Aomori Pref. as the conceptual site. It is a system in which materials are recycled by solar energy and industrial waste heat for a complex food industry. The conceptual site, although blessed with various marine products, are sometimes attacked by cold weather. Waste heat from a 250,000kW power plant, if transported by EHD heat pipes to the site, could provide roughly 400 times the heat required for production of agricultural and marine products, such as cabbages and fish meat. The waste heat, coupled with solar energy, should solve the problems resulting from hot waste water, if they could be utilized for the industrial purposes. The food industrial site that produces agricultural and marine products is considered to be suited as the center of the solar industrial complex incorporating farms. 5 refs., 3 figs.

  1. Performance of commercially available solar and heat pump water heaters

    International Nuclear Information System (INIS)

    Lloyd, C.R.; Kerr, A.S.D.

    2008-01-01

    Many countries are using policy incentives to encourage the adoption of energy-efficient hot water heating as a means of reducing greenhouse gas emissions. Such policies rely heavily on assumed performance factors for such systems. In-situ performance data for solar and heat pump hot water systems, however, are not copious in the literature. Otago University has been testing some systems available in New Zealand for a number of years. The results obtained are compared to international studies of in-situ performance of solar hot water systems and heat pump hot water systems, by converting the results from the international studies into a single index suitable for both solar and heat pump systems (COP). Variability in the international data is investigated as well as comparisons to model results. The conclusions suggest that there is not too much difference in performance between solar systems that have a permanently connected electric boost backup and heat pump systems over a wide range of environmental temperatures. The energy payback time was also calculated for electric boost solar flat plate systems as a function of both COP and hot water usage for a given value of embodied energy. The calculations generally bode well for solar systems but ensuring adequate system performance is paramount. In addition, such systems generally favour high usage rates to obtain good energy payback times

  2. Modeling patterns of hot water use in households

    Energy Technology Data Exchange (ETDEWEB)

    Lutz, James D.; Liu, Xiaomin; McMahon, James E.; Dunham, Camilla; Shown, Leslie J.; McCure, Quandra T.

    1996-01-01

    This report presents a detailed model of hot water use patterns in individual households. The model improves upon an existing model by including the effects of four conditions that were previously unaccounted for: the absence of a clothes washer; the absence of a dishwasher; a household consisting of seniors only; and a household that does not pay for its own hot water use. Although these four conditions can significantly affect residential hot water use, and have been noted in other studies, this is the first time that they have been incorporated into a detailed model. This model allows detailed evaluation of the impact of potential efficiency standards for water heaters and other market transformation policies.

  3. Seeded hot dark matter models with inflation

    Science.gov (United States)

    Gratsias, John; Scherrer, Robert J.; Steigman, Gary; Villumsen, Jens V.

    1993-01-01

    We examine massive neutrino (hot dark matter) models for large-scale structure in which the density perturbations are produced by randomly distributed relic seeds and by inflation. Power spectra, streaming velocities, and the Sachs-Wolfe quadrupole fluctuation are derived for this model. We find that the pure seeded hot dark matter model without inflation produces Sachs-Wolfe fluctuations far smaller than those seen by COBE. With the addition of inflationary perturbations, fluctuations consistent with COBE can be produced. The COBE results set the normalization of the inflationary component, which determines the large-scale (about 50/h Mpc) streaming velocities. The normalization of the seed power spectrum is a free parameter, which can be adjusted to obtain the desired fluctuations on small scales. The power spectra produced are very similar to those seen in mixed hot and cold dark matter models.

  4. Solar Storage Tank Insulation Influence on the Solar Systems Efficiency

    Directory of Open Access Journals (Sweden)

    Negoitescu Arina

    2012-09-01

    Full Text Available For the storage tank of a solar system for domestic hot water production was analyzed the insulation thickness and material influence. To this end, it was considered a private house, occupied by 3 persons, located in zone I of thermal radiation, for which has been simulated the domestic hot water production process. The tank outlet hot water temperature was considered of 45°C. For simulation purposes, as insulation materials for the storage tank were taking into account glass wool and polyurethane with various thicknesses. Finally, was carried out the comparative analysis of two types of tanks, in terms of the insulation thickness influence on the solar fraction, annual solar contribution and solar annual productivity. It resulted that polyurethane is the most advantageous from all points of view.

  5. To built a solar hot water heater to work the sustainability problem

    Directory of Open Access Journals (Sweden)

    Carretero Gómez, María Begoña

    2012-01-01

    Full Text Available We are commemorating the Education Decade for Sustainable Development. If we want to create positive towards our environment and its sustainable development we have to begin working at school. It is necessary to show our students what problems of the environment are and which solutions can be adopted. That is the reason we have planned this activity in our secondary school. We do think that by doing daily activities we have a good opportunity to fulfil this goal. An example of such experiences is the fabrication of a solar hot water heater to make them and their families more environment conscience.

  6. Modeling patterns of hot water use in households

    Energy Technology Data Exchange (ETDEWEB)

    Lutz, J.D.; Liu, Xiaomin; McMahon, J.E. [and others

    1996-11-01

    This report presents a detailed model of hot water use patterns in individual household. The model improves upon an existing model by including the effects of four conditions that were previously unaccounted for: the absence of a clothes washer; the absence of a dishwasher; a household consisting of seniors only; and a household that does not pay for its own hot water use. Although these four conditions can significantly affect residential hot water use, and have been noted in other studies, this is the first time that they have been incorporated into a detailed model. This model allows detailed evaluation of the impact of potential efficiency standards for water heaters and other market transformation policies. 21 refs., 3 figs., 10 tabs.

  7. Smart solar tanks for small solar domestic hot water systems

    DEFF Research Database (Denmark)

    Furbo, Simon; Andersen, Elsa; Knudsen, Søren

    2005-01-01

    Investigation of small SDHW systems based on smart solar tanks are presented. The domestic water in a smart solar tank can be heated both by solar collectors and by means of an auxiliary energy supply system. The auxiliary energy supply system – in this study electric heating elements – heats up...... systems, based on differently designed smart solar tanks and a traditional SDHW system were investigated by means of laboratory experiments and theoretical calculations. The investigations showed that the yearly thermal performance of SDHW systems with smart solar tanks is 5-35% higher than the thermal...... performance of traditional SDHW systems. Estimates indicate that the performance/cost ratio can be improved by up to 25% by using a smart solar tank instead of a traditional tank when the backup energy system is electric heating elements. Further, smart solar tanks are suitable for unknown, variable, large...

  8. Measurement and modelling of a multifunctional solar plus heatpump system from Nilan

    DEFF Research Database (Denmark)

    Perers, Bengt; Andersen, Elsa; Furbo, Simon

    A multifunctional solar and heat pump unit from Nilan has been installed in the Performance Test Facility (PTF) at DTU Byg Denmark. It is part of the IEA Task 44 cooperation. Multifunctional means in this case: Hot water, Air heating, Ventilation, Air heat recovery, Air filtering and Floor heating....... Nilan units, with additional air cooling and CO2 control, are also available. The unit has been in operation for more than one year. The aim has been to stress the system operation to different conditions in the lab, to learn more about the performance, but also to find possible improvements especially...... concerning advanced control. The operation into extreme states of high hot water demand and low air ventilation rates, has also been done to develop and validate a TRNSYS system model. The model was developed and validated for the first period of operation mainly winter and early spring conditions. Now...

  9. Preliminary design package for solar collector and solar pump

    Science.gov (United States)

    1978-01-01

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

  10. Evaluation of the ENVI-Met Vegetation Model of Four Common Tree Species in a Subtropical Hot-Humid Area

    Directory of Open Access Journals (Sweden)

    Zhixin Liu

    2018-05-01

    Full Text Available Urban trees can significantly improve the outdoor thermal environment, especially in subtropical zones. However, due to the lack of fundamental evaluations of numerical simulation models, design and modification strategies for optimizing the thermal environment in subtropical hot-humid climate zones cannot be proposed accurately. To resolve this issue, this study investigated the physiological parameters (leaf surface temperature and vapor flux and thermal effects (solar radiation, air temperature, and humidity of four common tree species (Michelia alba, Mangifera indica, Ficus microcarpa, and Bauhinia blakeana in both spring and summer in Guangzhou, China. A comprehensive comparison of the observed and modeled data from ENVI-met (v4.2 Science, a three-dimensional microclimate model was performed. The results show that the most fundamental weakness of ENVI-met is the limitation of input solar radiation, which cannot be input hourly in the current version and may impact the thermal environment in simulation. For the tree model, the discrepancy between modeled and observed microclimate parameters was acceptable. However, for the physiological parameters, ENVI-met tended to overestimate the leaf surface temperature and underestimate the vapor flux, especially at midday in summer. The simplified calculation of the tree model may be one of the main reasons. Furthermore, the thermal effect of trees, meaning the differences between nearby treeless sites and shaded areas, were all underestimated in ENVI-met for each microclimate variable. This study shows that the tree model is suitable in subtropical hot-humid climates, but also needs some improvement.

  11. Steady state model for the thermal regimes of shells of airships and hot air balloons

    Science.gov (United States)

    Luchev, Oleg A.

    1992-10-01

    A steady state model of the temperature regime of airships and hot air balloons shells is developed. The model includes three governing equations: the equation of the temperature field of airships or balloons shell, the integral equation for the radiative fluxes on the internal surface of the shell, and the integral equation for the natural convective heat exchange between the shell and the internal gas. In the model the following radiative fluxes on the shell external surface are considered: the direct and the earth reflected solar radiation, the diffuse solar radiation, the infrared radiation of the earth surface and that of the atmosphere. For the calculations of the infrared external radiation the model of the plane layer of the atmosphere is used. The convective heat transfer on the external surface of the shell is considered for the cases of the forced and the natural convection. To solve the mentioned set of the equations the numerical iterative procedure is developed. The model and the numerical procedure are used for the simulation study of the temperature fields of an airship shell under the forced and the natural convective heat transfer.

  12. Thermal performance behavior of a domestic hot water solar storage tank during consumption operation

    International Nuclear Information System (INIS)

    Dehghan, A.A.; Barzegar, A.

    2011-01-01

    Transient thermal performance behavior of a vertical storage tank of a domestic solar water heating system with a mantle heat exchanger has been investigated numerically in the discharge/consumption mode. It is assumed that the tank is initially stratified during its previous heat storing/charging operation. During the discharging period, the city cold water is fed at the bottom of the tank and hot water is extracted from its top outlet port for consumption. Meanwhile, the collector loop is assumed to be active. The conservation equations in the axis-symmetric cylindrical co-ordinate have been used and discretised by employing the finite volume method. The low Reynolds number (LRN) k - ω model is utilized for treating turbulence in the fluid. The influence of the tank Grashof number, the incoming cold fluid Reynolds number and the size of the inlet port of the heat storage tank on the transient thermal characteristics of the tank is investigated and discussed. It is found that for higher values of Grashof number, the pre-established thermal stratification is well preserved during the discharging operation mode. It is also noticed that in order to have a tank with a proper thermal performance and or have least mixing inside the tank during the consumption period, the tank inflow Reynolds number and or its inflow port diameter should be kept below certain values. In these cases, the storage tank is enabling to provide proper amount of hot water with a proper temperature for consumption purposes.

  13. Resonant tunneling diodes as energy-selective contacts used in hot-carrier solar cells

    International Nuclear Information System (INIS)

    Takeda, Yasuhiko; Sugimoto, Noriaki; Ichiki, Akihisa; Kusano, Yuya; Motohiro, Tomoyoshi

    2015-01-01

    Among the four features unique to hot-carrier solar cells (HC-SCs): (i) carrier thermalization time and (ii) carrier equilibration time in the absorber, (iii) energy-selection width and (iv) conductance of the energy-selective contacts (ESCs), requisites of (i)-(iii) for high conversion efficiency have been clarified. We have tackled the remaining issues related to (iv) in the present study. The detailed balance model of HC-SC operation has been improved to involve a finite value of the ESC conductance to find the required values, which in turn has been revealed to be feasible using resonant tunneling diodes (RTDs) consisting of semiconductor quantum dots (QDs) and quantum wells (QWs) by means of a formulation to calculate the conductance of the QD- and QW-RTDs derived using the rigorous solutions of the effective-mass Hamiltonians. Thus, all of the four requisites unique to HC-SCs to achieve high conversion efficiency have been elucidated, and the two requisites related to the ESCs can be fulfilled using the QD- and QW-RTDs

  14. Resonant tunneling diodes as energy-selective contacts used in hot-carrier solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Yasuhiko, E-mail: takeda@mosk.tytlabs.co.jp; Sugimoto, Noriaki [Toyota Central Research and Development Laboratories, Inc., 41-1, Yokomichi, Nagakute, Aichi 480-1192 (Japan); Ichiki, Akihisa [Green Mobility Collaborative Research Center, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601 (Japan); Kusano, Yuya [Green Mobility Collaborative Research Center, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601 (Japan); Toyota Motor Corp., 1200 Mishuku, Susono, Shizuoka 410-1193 (Japan); Motohiro, Tomoyoshi [Toyota Central Research and Development Laboratories, Inc., 41-1, Yokomichi, Nagakute, Aichi 480-1192 (Japan); Green Mobility Collaborative Research Center, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601 (Japan); Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601 (Japan)

    2015-09-28

    Among the four features unique to hot-carrier solar cells (HC-SCs): (i) carrier thermalization time and (ii) carrier equilibration time in the absorber, (iii) energy-selection width and (iv) conductance of the energy-selective contacts (ESCs), requisites of (i)-(iii) for high conversion efficiency have been clarified. We have tackled the remaining issues related to (iv) in the present study. The detailed balance model of HC-SC operation has been improved to involve a finite value of the ESC conductance to find the required values, which in turn has been revealed to be feasible using resonant tunneling diodes (RTDs) consisting of semiconductor quantum dots (QDs) and quantum wells (QWs) by means of a formulation to calculate the conductance of the QD- and QW-RTDs derived using the rigorous solutions of the effective-mass Hamiltonians. Thus, all of the four requisites unique to HC-SCs to achieve high conversion efficiency have been elucidated, and the two requisites related to the ESCs can be fulfilled using the QD- and QW-RTDs.

  15. Analysis of the validity of the F-chart method for the calculation of the solar contribution in comunitarian facilities of ACS; Analisis de la validez del metodo F-chart para el calculo de la contribucion solar en instalaciones comunitarias de ACS

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez Munoz, F.; Ruzafa Cueto, J.; Carrillo andres, A.; Cejudo Lopez, J. M.

    2008-07-01

    The FCHART method is extensively used in Spain as a tool for sizing solar hot water systems. However, when it comes to apply the method to installations with long runs of distribution and recirculation piping, we find the problem that FCHART does not explicitly address the effects of these pipes. In this paper, a centralized solar installation supplying hot water to a 28-apartment building is analyzed with FCHART and with detailed mathematical model. It is concluded that the hot water distribution network has a large impact on the solar fraction, whose magnitude is difficult to calculate other than by using the detailed mathematical model. (Author)

  16. Development of smart solar tanks

    DEFF Research Database (Denmark)

    Furbo, Simon; Andersen, Elsa

    1999-01-01

    The aim of the project is to develop smart solar tanks. A smart solar tank is a tank in which the domestic water can bee heated both by solar collectors and by an auxiliary energy supply system. The auxiliary energy supply system heats up the hot-water tank from the top and the water volume heated...... by the auxiliary energy supply system is fitted to the hot water consumption and consumption pattern. In periods with a large hot-water demand the volume is large, in periods with a small hot-water demand the volume is small. Based on measurements and calculations the advantage of smart SDHW systems is visualised....

  17. Hot water tank for use with a combination of solar energy and heat-pump desuperheating

    Science.gov (United States)

    Andrews, J.W.

    1980-06-25

    A water heater or system is described which includes a hot water tank having disposed therein a movable baffle to function as a barrier between the incoming volume of cold water entering the tank and the volume of heated water entering the tank which is heated by the circulation of the cold water through a solar collector and/or a desuperheater of a heat pump so as to optimize the manner in which heat is imparted to the water in accordance to the demand on the water heater or system. A supplemental heater is also provided and it is connected so as to supplement the heating of the water in the event that the solar collector and/or desuperheater cannot impart all of the desired heat input into the water.

  18. Hot water tank for use with a combination of solar energy and heat-pump desuperheating

    Science.gov (United States)

    Andrews, John W.

    1983-06-28

    A water heater or system which includes a hot water tank having disposed therein a movable baffle to function as a barrier between the incoming volume of cold water entering the tank and the volume of heated water entering the tank which is heated by the circulation of the cold water through a solar collector and/or a desuperheater of a heat pump so as to optimize the manner in which heat is imparted to the water in accordance to the demand on the water heater or system. A supplemental heater is also provided and it is connected so as to supplement the heating of the water in the event that the solar collector and/or desuperheater cannot impart all of the desired heat input into the water.

  19. Fiscal 1976 Sunshine Project result report. R and D on solar cooling/heating and hot water supply system; 1976 nendo taiyonetsu reidanbo kyuto system no kenkyu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1977-03-01

    This report describes the fiscal 1974-76 research result on solar cooling/heating and hot water supply systems. Research was made on survey and analysis of current R and D states, system analysis, energy impact analysis, installation sites of solar collectors, diffusion policy, profitability, and performance evaluation method. Main research results obtained are as follows. The effect of solar cooling/heating and hot water supply on the Japanese energy demand in 2000 is estimated to be 13% for residences and 5% for the other buildings. Environment pollution derived from solar cooling/heating is extremely less than that from conventional energy quantitatively. The facility cost is estimated to be probably 27,000yen/m{sup 2} in collector cost, and nearly 100,000yen/t in heat storage tank cost. As design data for solar cooling/heating systems, the estimation method of heat collection for every solar radiation rank, performance comparison of honeycomb type collectors, and various data for air heat collection systems are presented. (NEDO)

  20. Impact on a utility, utility customers and the environment of an ensemble of solar domestic hot water systems

    International Nuclear Information System (INIS)

    Cragan, K.E.; Klein, S.A.; Beckman, W.A.

    1995-01-01

    The benefits of the installation of a large number of solar domestic hot water (SDHW) systems are identified and quantified. The benefits of SDHW systems include reduced energy use, reduced electrical demand, and reduced pollution. The avoided emissions, capacity contribution, energy and demand savings were evaluated using the power generation schedules, emissions data and annual hourly load profiles from a Wisconsin utility. It is shown that each six square meter solar water heater system can save annually: 3,560 kWh of energy, 0.66 kW of peak demand, and over four tons of pollution

  1. Numerical modelling of multi-pass solar dryer filled with granite pebbles for thermal storage enhancement

    International Nuclear Information System (INIS)

    Kareem, M W; Habib, K; Ruslan, M H

    2015-01-01

    In this paper, a theoretical modelling of a cheap solar thermal dryer for small and medium scale farmers with multi-pass approach has been investigated. Comsol Multiphysics modelling tool was employed using numerical technique. The rock particles were used to enhance the thermal storage of the drying system. The local weather data were used during the simulation while parameters and coefficients were sourced from literature. An improvement on efficiency of up to 7% was recorded with error of 10 -5 when compared with the reported double pass solar collector. A fair distribution of hot air within the cabinets was also achieved. Though the modelling tool used was robust but the characterization of the system materials need to be done to improve the system accuracy and better prediction. (paper)

  2. The influence of weather on the thermal performance of solar heating systems

    DEFF Research Database (Denmark)

    Andersen, Elsa; Furbo, Simon; Shah, Louise Jivan

    2003-01-01

    . The investigation is based on calculations with validated models. Solar heating systems with different solar collector types, heat storage volumes and solar fractions are included in the investigation. The yearly solar radiation varies with approximately 20 % in the period from 1990 until 2002. The calculations......The influence of weather on the thermal performance of solar combi systems, solar domestic hot water systems and solar heating plants is investigated. The investigation is based on weather data from the Danish Design Reference Year, DRY and weather data measured for a period from 1990 until 2002...... show that the thermal performance of the investigated systems varies due to the weather variation. The variation of the yearly thermal performance of a solar heating plant is about 40 % while the variation of the yearly thermal performance of a solar domestic hot water system is about 30...

  3. Extracting hot carriers from photoexcited semiconductor nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Xiaoyang

    2014-12-10

    This research program addresses a fundamental question related to the use of nanomaterials in solar energy -- namely, whether semiconductor nanocrystals (NCs) can help surpass the efficiency limits, the so-called “Shockley-Queisser” limit, in conventional solar cells. In these cells, absorption of photons with energies above the semiconductor bandgap generates “hot” charge carriers that quickly “cool” to the band edges before they can be utilized to do work; this sets the solar cell efficiency at a limit of ~31%. If instead, all of the energy of the hot carriers could be captured, solar-to-electric power conversion efficiencies could be increased, theoretically, to as high as 66%. A potential route to capture this energy is to utilize semiconductor nanocrystals. In these materials, the quasi-continuous conduction and valence bands of the bulk semiconductor become discretized due to confinement of the charge carriers. Consequently, the energy spacing between the electronic levels can be much larger than the highest phonon frequency of the lattice, creating a “phonon bottleneck” wherein hot-carrier relaxation is possible via slower multiphonon emission. For example, hot-electron lifetimes as long as ~1 ns have been observed in NCs grown by molecular beam epitaxy. In colloidal NCs, long lifetimes have been demonstrated through careful design of the nanocrystal interfaces. Due to their ability to slow electronic relaxation, semiconductor NCs can in principle enable extraction of hot carriers before they cool to the band edges, leading to more efficient solar cells.

  4. Investigation of a heat storage for a solar heating system for combined space heating and domestic hot water supply for homeowner´s association "Bakken"

    DEFF Research Database (Denmark)

    Vejen, Niels Kristian

    1998-01-01

    A heat storage for a solar heating system for combined space heating and domestic hot water supply was tested in a laboratory test facility.The heat storage consist of a mantle tank with water for the heating system and of a hot water tank, which by means of thermosyphoning is heated by the water...

  5. Integrated solar water-heater and solar water cooler performance during winter time

    International Nuclear Information System (INIS)

    Shaikh, N.U.; Siddiqui, M.A

    2012-01-01

    Solar powered water heater and water cooler is an important contribution for the reduction of fossil fuel consumptions and harmful emissions to the environment. This study aims to harness the available solar potential of Pakistan and provide an option fulfilling the domestic hot and cold water demands during winter and summer seasons respectively. The system was designed for the tap-water temperature of 65 degree C (149 degree F) and the chilled drinking-water temperature of 14 degree C (57 degree F) that are the recommended temperatures by World Health Organization (WHO). The solar water heater serves one of the facilities of the Department of Mechanical Engineering at NED University of Engineering and Technology whereas, the solar water cooler will provide drinking water to approximately 50 people including both faculty and students. A pair of single glazed flat plate solar collector was installed to convert solar radiations to heat. Hot water storage and supply system was carefully designed and fabricated to obtain the designed tap-water temperature. Vapour-absorption refrigeration system was designed to chill drinking water. Intensity of solar radiations falling on the solar collector, water temperatures at the inlet and outlet of the solar collectors and the tap water temperature were measured and analyzed at different hours of the day and at different days of the month. The results show that the installed solar collector system has potential to feed hot water of temperatures ranging from 65 degree C (149 degree F) to 70 Degree C (158 degree F), that is the required hot water temperature to operate a vapour absorption chilled water production system. (author)

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

    DEFF Research Database (Denmark)

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

    2017-01-01

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

  7. PWR hot leg natural circulation modeling with MELCOR code

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jae Hong; Lee, Jong In [Korea Institute of Nuclear Safety, Taejon (Korea, Republic of)

    1998-12-31

    Previous MELCOR and SCDAP/RELAP5 nodalizations for simulating the counter-current, natural circulation behavior of vapor flow within the RCS hot legs and SG U-tubes when core damage progress can not be applied to the steady state and water-filled conditions during the initial period of accident progression because of the artificially high loss coefficients in the hot legs and SG U-tubes which were chosen from results of COMMIX calculation and the Westinghouse natural circulation experiments in a 1/7-scale facility for simulating steam natural circulation behavior in the vessel and circulation modeling which can be used both for the liquid flow condition at steady state and for the vapor flow condition at the later period of in-vessel core damage. For this, the drag forces resulting from the momentum exchange effects between the two vapor streams in the hot leg was modeled as a pressure drop by pump model. This hot leg natural circulation modeling of MELCOR was able to reproduce similar mass flow rates with those predicted by previous models. 6 refs., 2 figs. (Author)

  8. PWR hot leg natural circulation modeling with MELCOR code

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jae Hong; Lee, Jong In [Korea Institute of Nuclear Safety, Taejon (Korea, Republic of)

    1997-12-31

    Previous MELCOR and SCDAP/RELAP5 nodalizations for simulating the counter-current, natural circulation behavior of vapor flow within the RCS hot legs and SG U-tubes when core damage progress can not be applied to the steady state and water-filled conditions during the initial period of accident progression because of the artificially high loss coefficients in the hot legs and SG U-tubes which were chosen from results of COMMIX calculation and the Westinghouse natural circulation experiments in a 1/7-scale facility for simulating steam natural circulation behavior in the vessel and circulation modeling which can be used both for the liquid flow condition at steady state and for the vapor flow condition at the later period of in-vessel core damage. For this, the drag forces resulting from the momentum exchange effects between the two vapor streams in the hot leg was modeled as a pressure drop by pump model. This hot leg natural circulation modeling of MELCOR was able to reproduce similar mass flow rates with those predicted by previous models. 6 refs., 2 figs. (Author)

  9. Modelling solar-like oscillators

    Energy Technology Data Exchange (ETDEWEB)

    Eggenberger, P; Miglio, A [Institut d' Astrophysique et de Geophysique de l' Universite de Liege, 17 Allee du 6 Aout, B-4000 Liege (Belgium); Carrier, F [Institute of Astronomy, University of Leuven, Celestijnenlaan 200 D, B-3001 Leuven (Belgium); Mathis, S [CEA/DSM/DAPNIA/Service d' Astrophysique, CEA/Saclay, AIM-Unite Mixte de Recherche CEA-CNRS-Universite Paris VII, UMR 7158, 91191 Gif-sur-Yvette Cedex (France)], E-mail: eggenberger@Qastro.ulg.ac.be

    2008-10-15

    The computation of models of stars for which solar-like oscillations have been observed is discussed. After a brief intoduction on the observations of solar-like oscillations, the modelling of isolated stars and of stars belonging to a binary system is presented with specific examples of recent theoretical calibrations. Finally the input physics introduced in stellar evolution codes for the computation of solar-type stars is discussed with a peculiar emphasis on the modelling of rotation for these stars.

  10. Investigations of solar combi systems

    DEFF Research Database (Denmark)

    Andersen, Elsa

    2005-01-01

    ). However, it is still too early to draw conclusions on the design of solar combi systems. Among others, the following questions needs to be answered: Is an external domestic hot water preparation more desirable than an internal domestic hot water preparation? Is a stratification manifold always more......A large variety of solar combi systems are on the marked to day. The best performing systems are highly advanced energy systems with thermal stratification manifolds, an efficient boiler and only one control system, which controls both the boiler and the solar collector loop (Weiss et al., 2003...... desirable than a fixed inlet position? This paper presents experimental investigations of an advanced solar combi system with thermal stratification manifold inlets both in the solar collector loop and in the space heating system and with an external domestic hot water preparation. Theoretical...

  11. A dynamic model of an innovative high-temperature solar heating and cooling system

    Directory of Open Access Journals (Sweden)

    Buonomano Annamaria

    2016-01-01

    Full Text Available In this paper a new simulation model of a novel solar heating and cooling system based on innovative high temperature flat plate evacuated solar thermal collector is presented. The system configuration includes: flat-plate evacuated solar collectors, a double-stage LiBr-H2O absorption chiller, gas-fired auxiliary heater, a closed loop cooling tower, pumps, heat exchangers, storage tanks, valves, mixers and controllers. The novelty of this study lies in the utilization of flat-plate stationary solar collectors, manufactured by TVP Solar, rather than concentrating ones (typically adopted for driving double-stage absorption chillers. Such devices show ultra-high thermal efficiencies, even at very high (about 200°C operating temperatures, thanks to the high vacuum insulation. Aim of the paper is to analyse the energy and economic feasibility of such novel technology, by including it in a prototypal solar heating and cooling system. For this purpose, the solar heating and cooling system design and performance were analysed by means of a purposely developed dynamic simulation model, implemented in TRNSYS. A suitable case study is also presented. Here, the simulated plant is conceived for the space heating and cooling and the domestic hot water production of a small building, whose energy needs are fulfilled through a real installation (settled also for experimental purposes built up close to Naples (South Italy. Simulation results show that the investigated system is able to reach high thermal efficiencies and very good energy performance. Finally, the economic analysis shows results comparable to those achieved through similar renewable energy systems.

  12. Photovoltaic-thermal (PV/T) solar collectors: Features and performance modelling

    International Nuclear Information System (INIS)

    Atienza-Márquez, Antonio; Bruno, Joan Carles; Coronas, Alberto; Korolija, Ivan; Greenough, Richard; Wright, Andy

    2017-01-01

    Currently, the electrical efficiency of photovoltaic (PV) solar cells ranges between 5–25%. One of the most important parameters that affects the electrical efficiency of a PV collector is the temperature of its cells: the higher temperature, the lower is the efficiency. Photovoltaic/thermal (PV/T) technology is a potential solution to ensure an acceptable solar energy conversion. The PV/T technology produces both electrical and thermal energy simultaneously. It is suitable for low temperature applications (25–40 o C) and overall efficiency increases compared to individual collectors. This paper describes an installation in a single-family house where PV/T collectors are coupled with a ground heat exchanger and a heat pump for domestic hot water and space heating purposes. The aim of this work is twofold. First, the features of the PV/T technology are analyzed. Second, a model of a flat-plate PV/T water collector was developed in TRNSYS in order to analyze collectors performance. (author)

  13. Infrared investigation of the temperature structure of the solar atmosphere

    International Nuclear Information System (INIS)

    Allen, R.G.

    1978-01-01

    Narrow-band continuum limb darkening observations of the sun were taken with the Infrared Spectrometer and the West Auxiliary of the McMath Solar Telescope during the first half of 1974. The infrared limb darkening measures were used with a few absolute intensity and limb darkening measures of other investigators to develop a series of empirical solar models. The temperatures in most of the solar models were adjusted until the predictions of the model atmosphere program matched the observational measures as well as possible. Limb darkening residuals were calculated by subtracting the observational measures of the limb darkening from the limb darkening measures that were computed from the program. Experiments with several models indicated that a steep temperature gradient was needed to fit the observations at short wavelengths while a rather low temperature gradient was needed at long wavelengths. Non-LTE effects and errors in the H - opacity were ruled out as possible sources of this discrepancy. An excellent fit to the observations was ultimately achieved with a two-component LTE solar model. The hot component of this model represents the half of the solar surface that is above the median temperature at each depth; while the cool component represents the half of the solar surface that is below the median temperature. Most of the observations are fitted to within the expected errors by this model. Discrepancies below 4500 A are probably due to line blanketing. The splitting between the hot and cool components of the model is consistent with current estimates of the rms intensity fluctuations in the solar atmosphere. The model also resembles several theoretical two-component models that have recently appeared in the literature

  14. Equivalent circuit-level model of quantum cascade lasers with integrated hot-electron and hot-phonon effects

    Science.gov (United States)

    Yousefvand, H. R.

    2017-12-01

    We report a study of the effects of hot-electron and hot-phonon dynamics on the output characteristics of quantum cascade lasers (QCLs) using an equivalent circuit-level model. The model is developed from the energy balance equation to adopt the electron temperature in the active region levels, the heat transfer equation to include the lattice temperature, the nonequilibrium phonon rate to account for the hot phonon dynamics and simplified two-level rate equations to incorporate the carrier and photon dynamics in the active region. This technique simplifies the description of the electron-phonon interaction in QCLs far from the equilibrium condition. Using the presented model, the steady and transient responses of the QCLs for a wide range of sink temperatures (80 to 320 K) are investigated and analysed. The model enables us to explain the operating characteristics found in QCLs. This predictive model is expected to be applicable to all QCL material systems operating in pulsed and cw regimes.

  15. Solar thermal in France

    International Nuclear Information System (INIS)

    Letz, T.

    2006-01-01

    This article gives details of Plan Soleil established in 2000 by the French Agency for Environment and Energy Management and its identification of solar hot water systems and combined domestic solar hot water and space heating as promising sectors for development. The setting up of a support scheme for investment by Plan Soleil is discussed along with subsidies and grants, manufacturers and importers, the guarantee of solar results, and the quality of plants, components, and installers. The costs of thermal solar equipment, and results of the French assessment programme are considered. The need for quality standards is stressed

  16. Prospects for jointly using solar and wind energy for heat supply and hot water supply to private houses under the conditions of Baku

    International Nuclear Information System (INIS)

    Salamov, O. M.; Aliev, F. F.

    2013-01-01

    This paper analyzes the discovery of the potential for jointly using solar and wind energy for heat supply (HS) and hot water supply (HWS) to a one-family private house located in the Apsheron Peninsula. (authors)

  17. Models of hot stellar systems

    International Nuclear Information System (INIS)

    Van Albada, T.S.

    1986-01-01

    Elliptical galaxies consist almost entirely of stars. Sites of recent star formation are rare, and most stars are believed to be several billion years old, perhaps as old as the Universe itself (--10/sup 10/ yrs). Stellar motions in ellipticals show a modest amount of circulation about the center of the system, but most support against the force of gravity is provided by random motions; for this reason ellipticals are called 'hot' stellar systems. Spiral galaxies usually also contain an appreciable amount of gas (--10%, mainly atomic hydrogen) and new stars are continually being formed out of this gas, especially in the spiral arms. In contrast to ellipticals, support against gravity in spiral galaxies comes almost entirely from rotation; random motions of the stars with respect to rotation are small. Consequently, spiral galaxies are called 'cold' stellar systems. Other than in hot systems, in cold systems the collective response of stars to variations in the force field is an essential part of the dynamics. The present overview is limited to mathematical models of hot systems. Computational methods are also discussed

  18. Modelling and simulation of a hybrid solar heating system for greenhouse applications using Matlab/Simulink

    International Nuclear Information System (INIS)

    Kıyan, Metin; Bingöl, Ekin; Melikoğlu, Mehmet; Albostan, Ayhan

    2013-01-01

    Highlights: • Matlab/Simulink modelling of a solar hybrid greenhouse. • Estimation of greenhouse gas emission reductions. • Feasibility and cost analysis of the system. - Abstract: Solar energy is a major renewable energy source and hybrid solar systems are gaining increased academic and industrial attention due to the unique advantages they offer. In this paper, a mathematical model has been developed to investigate the thermal behavior of a greenhouse heated by a hybrid solar collector system. This hybrid system contains an evacuated tube solar heat collector unit, an auxiliary fossil fuel heating unit, a hot water storage unit, control and piping units. A Matlab/Simulink based model and software has been developed to predict the storage water temperature, greenhouse indoor temperature and the amount of auxiliary fuel, as a function of various design parameters of the greenhouse such as location, dimensions, and meteorological data of the region. As a case study, a greenhouse located in Şanlıurfa/Turkey has been simulated based on recent meteorological data and aforementioned hybrid system. The results of simulations performed on an annual basis indicate that revising the existing fossil fuel system with the proposed hybrid system, is economically feasible for most cases, however it requires a slightly longer payback period than expected. On the other hand, by reducing the greenhouse gas emissions significantly, it has a considerable positive environmental impact. The developed dynamic simulation method can be further used for designing heating systems for various solar greenhouses and optimizing the solar collector and thermal storage sizes

  19. Models and methods for hot spot safety work

    DEFF Research Database (Denmark)

    Vistisen, Dorte

    2002-01-01

    Despite the fact that millions DKK each year are spent on improving roadsafety in Denmark, funds for traffic safety are limited. It is therefore vital to spend the resources as effectively as possible. This thesis is concerned with the area of traffic safety denoted "hot spot safety work", which...... is the task of improving road safety through alterations of the geometrical and environmental characteristics of the existing road network. The presently applied models and methods in hot spot safety work on the Danish road network were developed about two decades ago, when data was more limited and software...... and statistical methods less developed. The purpose of this thesis is to contribute to improving "State of the art" in Denmark. Basis for the systematic hot spot safety work are the models describing the variation in accident counts on the road network. In the thesis hierarchical models disaggregated on time...

  20. Determining the energy performance of manually controlled solar shades: A stochastic model based co-simulation analysis

    International Nuclear Information System (INIS)

    Yao, Jian

    2014-01-01

    Highlights: • Driving factor for adjustment of manually controlled solar shades was determined. • A stochastic model for manual solar shades was constructed using Markov method. • Co-simulation with Energyplus was carried out in BCVTB. • External shading even manually controlled should be used prior to LOW-E windows. • Previous studies on manual solar shades may overestimate energy savings. - Abstract: Solar shading devices play a significant role in reducing building energy consumption and maintaining a comfortable indoor condition. In this paper, a typical office building with internal roller shades in hot summer and cold winter zone was selected to determine the driving factor of control behavior of manual solar shades. Solar radiation was determined as the major factor in driving solar shading adjustment based on field measurements and logit analysis and then a stochastic model for manually adjusted solar shades was constructed by using Markov method. This model was used in BCVTB for further co-simulation with Energyplus to determine the impact of the control behavior of solar shades on energy performance. The results show that manually adjusted solar shades, whatever located inside or outside, have a relatively high energy saving performance than clear-pane windows while only external shades perform better than regularly used LOW-E windows. Simulation also indicates that using an ideal assumption of solar shade adjustment as most studies do in building simulation may lead to an overestimation of energy saving by about 16–30%. There is a need to improve occupants’ actions on shades to more effectively respond to outdoor conditions in order to lower energy consumption, and this improvement can be easily achieved by using simple strategies as a guide to control manual solar shades

  1. Fiscal 1974 Sunshine Project result report. Research on solar cooling/heating and hot water supply system; 1974 nendo taiyonetsu reidanbo kyuto system no kenkyu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1975-03-01

    This report describes the fiscal 1974 research result on solar cooling/heating and hot water supply system. This 3- year project from fiscal 1974 to 1976 aims to predict the share of solar energy in future cooling/heating and hot water supply energy demand, and develop simulation technology. The project surveys and analyzes current domestic and overseas development states, and studies various systems to obtain characteristics of every system, pursuit an optimum implementation, and establish a diffusion plan. Future energy consumptions and prices are predicted in relation to energy saving, and the utilization impact of solar energy is analyzed. Study is also made on diffusion plan, profitability and performance evaluation method. Among these schedules, in fiscal 1974 based on the survey and analysis on previous domestic and overseas development states, features and problems were arranged every system and application. The basic study on system simulation, and rough feasibility study on solar heat systems by conventional technique were carried out. The basic data on performance evaluation standards were also prepared. (NEDO)

  2. Solar Deployment System (SolarDS) Model: Documentation and Sample Results

    Energy Technology Data Exchange (ETDEWEB)

    Denholm, P.; Drury, E.; Margolis, R.

    2009-09-01

    The Solar Deployment System (SolarDS) model is a bottom-up, market penetration model that simulates the potential adoption of photovoltaics (PV) on residential and commercial rooftops in the continental United States through 2030. NREL developed SolarDS to examine the market competitiveness of PV based on regional solar resources, capital costs, electricity prices, utility rate structures, and federal and local incentives. The model uses the projected financial performance of PV systems to simulate PV adoption for building types and regions then aggregates adoption to state and national levels. The main components of SolarDS include a PV performance simulator, a PV annual revenue calculator, a PV financial performance calculator, a PV market share calculator, and a regional aggregator. The model simulates a variety of installed PV capacity for a range of user-specified input parameters. PV market penetration levels from 15 to 193 GW by 2030 were simulated in preliminary model runs. SolarDS results are primarily driven by three model assumptions: (1) future PV cost reductions, (2) the maximum PV market share assumed for systems with given financial performance, and (3) PV financing parameters and policy-driven assumptions, such as the possible future cost of carbon emissions.

  3. Hot air balloon engine

    Energy Technology Data Exchange (ETDEWEB)

    Edmonds, Ian [Solartran Pty Ltd, 12 Lentara Street, Kenmore, Brisbane 4069 (Australia)

    2009-04-15

    This paper describes a solar powered reciprocating engine based on the use of a tethered hot air balloon fuelled by hot air from a glazed collector. The basic theory of the balloon engine is derived and used to predict the performance of engines in the 10 kW to 1 MW range. The engine can operate over several thousand metres altitude with thermal efficiencies higher than 5%. The engine thermal efficiency compares favorably with the efficiency of other engines, such as solar updraft towers, that also utilize the atmospheric temperature gradient but are limited by technical constraints to operate over a much lower altitude range. The increased efficiency allows the use of smaller area glazed collectors. Preliminary cost estimates suggest a lower $/W installation cost than equivalent power output tower engines. (author)

  4. Modeling Hot-Spot Contributions in Shocked High Explosives at the Mesoscale

    Energy Technology Data Exchange (ETDEWEB)

    Harrier, Danielle [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-08-12

    When looking at performance of high explosives, the defects within the explosive become very important. Plastic bonded explosives, or PBXs, contain voids of air and bonder between the particles of explosive material that aid in the ignition of the explosive. These voids collapse in high pressure shock conditions, which leads to the formation of hot spots. Hot spots are localized high temperature and high pressure regions that cause significant changes in the way the explosive material detonates. Previously hot spots have been overlooked with modeling, but now scientists are realizing their importance and new modeling systems that can accurately model hot spots are underway.

  5. Pre-cometary ice composition from hot core chemistry.

    Science.gov (United States)

    Tornow, Carmen; Kührt, Ekkehard; Motschmann, Uwe

    2005-10-01

    Pre-cometary ice located around star-forming regions contains molecules that are pre-biotic compounds or pre-biotic precursors. Molecular line surveys of hot cores provide information on the composition of the ice since it sublimates near these sites. We have combined a hydrostatic hot core model with a complex network of chemical reactions to calculate the time-dependent abundances of molecules, ions, and radicals. The model considers the interaction between the ice and gas phase. It is applied to the Orion hot core where high-mass star formation occurs, and to the solar-mass binary protostar system IRAS 16293-2422. Our calculations show that at the end of the hot core phase both star-forming sites produce the same prebiotic CN-bearing molecules. However, in the Orion hot core these molecules are formed in larger abundances. A comparison of the calculated values with the abundances derived from the observed line data requires a chemically unprocessed molecular cloud as the initial state of hot core evolution. Thus, it appears that these objects are formed at a much younger cloud stage than previously thought. This implies that the ice phase of the young clouds does not contain CN-bearing molecules in large abundances before the hot core has been formed. The pre-biotic molecules synthesized in hot cores cause a chemical enrichment in the gas phase and in the pre-cometary ice. This enrichment is thought to be an important extraterrestrial aspect of the formation of life on Earth and elsewhere.

  6. Model Solar Energy Training Program II. Final Report, July 1, 1981-June 30, 1982.

    Science.gov (United States)

    Talcott Mountain Science Center, Avon, CT.

    Trained personnel will be needed in the future to install solar energy heating and hot water systems, and public school vocational education teachers will be needed to train these technicians. A project to train high school vocational teachers so that they can teach their students about solar energy concepts, manufacturing techniques, testing, and…

  7. Consumer impacts on dividends from solar water heating

    Energy Technology Data Exchange (ETDEWEB)

    Hill, F.; Levermore, G. [University of Manchester, Manchester (United Kingdom); Lynch, H. [Centre for Alternative Technology, Machynlleth, University of East London, London (United Kingdom)

    2011-01-15

    Common domestic solar water heating system usage patterns were investigated by a survey of 55 installations. These usage patterns were modelled by simulation based on the actual occupants' use of boiler or other auxiliary heating control strategies. These strategies were not optimal, as often assumed. The effectiveness of the technology was found to be highly sensitive to the time settings used for auxiliary water heating, and the 65% of solar householders using their boilers in the mornings were found to be forgoing 75% of their potential savings. Additionally, 92% of consumers were found to be small households, whose potential savings were only 23% of those of larger households, which use more hot water. Overall the majority (at least 60%) of the systems surveyed were found to be achieving no more than 6% of their potential savings. Incorporating consideration of Legionella issues, results indicate that if solar thermal technology is to deliver its potential to CO2 reduction targets: solar householders must avoid any use of their auxiliary water heating systems before the end of the main warmth of the day, grants for solar technology should be focused on households with higher hot water demands, and particularly on those that are dependent on electricity for water heating, health and safety requirements for hot water storage must be reviewed and, if possible, required temperatures should be set at a lower level, so that carbon savings from solar water heating may be optimized.

  8. Development of a Greek solar map based on solar model estimations

    Science.gov (United States)

    Kambezidis, H. D.; Psiloglou, B. E.; Kavadias, K. A.; Paliatsos, A. G.; Bartzokas, A.

    2016-05-01

    The realization of Renewable Energy Sources (RES) for power generation as the only environmentally friendly solution, moved solar systems to the forefront of the energy market in the last decade. The capacity of the solar power doubles almost every two years in many European countries, including Greece. This rise has brought the need for reliable predictions of meteorological data that can easily be utilized for proper RES-site allocation. The absence of solar measurements has, therefore, raised the demand for deploying a suitable model in order to create a solar map. The generation of a solar map for Greece, could provide solid foundations on the prediction of the energy production of a solar power plant that is installed in the area, by providing an estimation of the solar energy acquired at each longitude and latitude of the map. In the present work, the well-known Meteorological Radiation Model (MRM), a broadband solar radiation model, is engaged. This model utilizes common meteorological data, such as air temperature, relative humidity, barometric pressure and sunshine duration, in order to calculate solar radiation through MRM for areas where such data are not available. Hourly values of the above meteorological parameters are acquired from 39 meteorological stations, evenly dispersed around Greece; hourly values of solar radiation are calculated from MRM. Then, by using an integrated spatial interpolation method, a Greek solar energy map is generated, providing annual solar energy values all over Greece.

  9. Optimal operation by dynamic programming in a solar/electric hot-water system; Taiyonetsu/denryoku kyuto system no doteki keikakuho ni yoru saiteki un`yo

    Energy Technology Data Exchange (ETDEWEB)

    Edo, S; Kenmoku, Y; Sakakibara, T [Toyohashi University of Technology, Aichi (Japan); Nakagawa, S [Maizuru College of Technology, Kyoto (Japan); Kawamoto, T [Shizuoka University, Shizuoka (Japan)

    1997-11-25

    With regard to utilization of a solar/electric hot-water system, a discussion was given by using a dynamic programming method on operation of a system which minimizes power charge. The discussed system is an installation in a welfare facility accommodating 100 persons, where solar heat is stored in a heat storage tank from a heat collector, and utilized for hot water supply. If the solar heat is insufficient for required hot water quantity, the water is heated by using an electric heater. The discussion compared the system operation using the dynamic programming method with the following two systems: the operation method 1, which does not utilize insolation forecast and the operation method 2, in which insolation forecast is utilized and late-night electric power is utilized for heating water in shortage. As a result of the calculation, the operation using the dynamic programming method conducts heat storage by utilizing the late-night power even if insolation is sufficient in winter in order to suppress heating by utilizing late-night power for days with less insolation. Thus, suppression is given on excessive utilization of day-time power and on rise in annual maximum power demand. It was found that the present system reduces power consumption by 37.7% when compared with the operation method 1, and 22.7% when compared even with the operation method 2. 3 refs., 5 figs., 3 tabs.

  10. Solar thermal heating and cooling. A bibliography with abstracts

    Science.gov (United States)

    Arenson, M.

    1979-01-01

    This bibliographic series cites and abstracts the literature and technical papers on the heating and cooling of buildings with solar thermal energy. Over 650 citations are arranged in the following categories: space heating and cooling systems; space heating and cooling models; building energy conservation; architectural considerations, thermal load computations; thermal load measurements, domestic hot water, solar and atmospheric radiation, swimming pools; and economics.

  11. Forced-circulation solar water heater using a solar battery; Taiyo denchi wo mochiita kyosei junkanshiki taiyonetsu onsuiki

    Energy Technology Data Exchange (ETDEWEB)

    Asai, S; Mizuno, T [Yazaki Resources Co. Ltd., Shizuoka (Japan)

    1996-10-27

    For the purpose of satisfying demands for qualitative improvement on tapwater temperature and pressure, an indirect-type solar water heater using solar cells, in which a closed type hot water storage tank connected directly to the water supply is integrated with a solar collector, was examined for its characteristics and performance. The heat collecting medium is a water solution of polypropylene glycol, which circulates through the solar collector pump, cistern, solar collector, and heat exchanger (hot water storage tank). The results of the test are summarized below. When comparison is made between the two solar collector pump control methods, the solar cells direct connection method and the differential thermo method utilizing temperature difference between the solar collector and the hot water storage tank, they are alike in collecting heat on clear days, but on cloudy days the latter collects 5% more than the former. In winter, when the heat exchanger heat transfer area is 0.4m{sup 2} large, a further increase in the area improves but a little the heat collecting efficiency. An increase in the medium flow rate and temperature, or in the Reynolds number, enhances the heat collecting efficiency. 13 figs., 6 tabs.

  12. Solar energy

    Science.gov (United States)

    Rapp, D.

    1981-01-01

    The book opens with a review of the patterns of energy use and resources in the United States, and an exploration of the potential of solar energy to supply some of this energy in the future. This is followed by background material on solar geometry, solar intensities, flat plate collectors, and economics. Detailed attention is then given to a variety of solar units and systems, including domestic hot water systems, space heating systems, solar-assisted heat pumps, intermediate temperature collectors, space heating/cooling systems, concentrating collectors for high temperatures, storage systems, and solar total energy systems. Finally, rights to solar access are discussed.

  13. Hot news recommendation system from heterogeneous websites based on bayesian model.

    Science.gov (United States)

    Xia, Zhengyou; Xu, Shengwu; Liu, Ningzhong; Zhao, Zhengkang

    2014-01-01

    The most current news recommendations are suitable for news which comes from a single news website, not for news from different heterogeneous news websites. Previous researches about news recommender systems based on different strategies have been proposed to provide news personalization services for online news readers. However, little research work has been reported on utilizing hundreds of heterogeneous news websites to provide top hot news services for group customers (e.g., government staffs). In this paper, we propose a hot news recommendation model based on Bayesian model, which is from hundreds of different news websites. In the model, we determine whether the news is hot news by calculating the joint probability of the news. We evaluate and compare our proposed recommendation model with the results of human experts on the real data sets. Experimental results demonstrate the reliability and effectiveness of our method. We also implement this model in hot news recommendation system of Hangzhou city government in year 2013, which achieves very good results.

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

    DEFF Research Database (Denmark)

    Tian, Zhiyong; Perers, Bengt; Furbo, Simon

    2018-01-01

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

  15. Thermal solar energy. Collective domestic hot water installations

    International Nuclear Information System (INIS)

    Garnier, Cedric; Chauvet, Chrystele; Fourrier, Pascal

    2016-01-01

    This brochure, edited by ADEME, the French office for energy management and sustainable development, gives a basic outlook on the way to complete the installation of a collective domestic water solar heating system. After some recall of what is solar energy, the thermal solar technology and the energy savings it may induce, this document presents the main hydraulic configurations of a solar heating system with water storage, the dimensioning of a solar water heating system and its cost estimation, the installation and the commissioning of the system, the monitoring and maintenance operations

  16. Energy Savings for Solar Heating Systems

    DEFF Research Database (Denmark)

    Thür, Alexander; Furbo, Simon; Shah, Louise Jivan

    2004-01-01

    , various simulations of solar heating systems were done for different hot water demands and collector sizes. The result shows that the potential of fuel reduction can be much higher than the solar gain of the solar thermal system. For some conditions the fuel reduction can be up to the double of the solar......In this paper the realistic behaviour and efficiency of heating systems were analysed, based on long term monitoring projects. Based on the measurements a boiler model was evaluated. Comparisons of measured and calculated fuel consumptions showed a good degree of similarity. With the boiler model...... gain due to a strong increase of the system efficiency. As the monitored boilers were not older than 3 years, it can be assumed that the saving potential with older boilers could be even higher than calculated in this paper....

  17. Validation of a Hot Water Distribution Model Using Laboratory and Field Data

    Energy Technology Data Exchange (ETDEWEB)

    Backman, C.; Hoeschele, M.

    2013-07-01

    Characterizing the performance of hot water distribution systems is a critical step in developing best practice guidelines for the design and installation of high performance hot water systems. Developing and validating simulation models is critical to this effort, as well as collecting accurate input data to drive the models. In this project, the ARBI team validated the newly developed TRNSYS Type 604 pipe model against both detailed laboratory and field distribution system performance data. Validation efforts indicate that the model performs very well in handling different pipe materials, insulation cases, and varying hot water load conditions. Limitations of the model include the complexity of setting up the input file and long simulation run times. In addition to completing validation activities, this project looked at recent field hot water studies to better understand use patterns and potential behavioral changes as homeowners convert from conventional storage water heaters to gas tankless units. Based on these datasets, we conclude that the current Energy Factor test procedure overestimates typical use and underestimates the number of hot water draws. This has implications for both equipment and distribution system performance. Gas tankless water heaters were found to impact how people use hot water, but the data does not necessarily suggest an increase in usage. Further study in hot water usage and patterns is needed to better define these characteristics in different climates and home vintages.

  18. Validation of a Hot Water Distribution Model Using Laboratory and Field Data

    Energy Technology Data Exchange (ETDEWEB)

    Backman, C. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Hoeschele, M. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

    2013-07-01

    Characterizing the performance of hot water distribution systems is a critical step in developing best practice guidelines for the design and installation of high performance hot water systems. Developing and validating simulation models is critical to this effort, as well as collecting accurate input data to drive the models. In this project, the Building America research team ARBI validated the newly developed TRNSYS Type 604 pipe model against both detailed laboratory and field distribution system performance data. Validation efforts indicate that the model performs very well in handling different pipe materials, insulation cases, and varying hot water load conditions. Limitations of the model include the complexity of setting up the input file and long simulation run times. This project also looked at recent field hot water studies to better understand use patterns and potential behavioral changes as homeowners convert from conventional storage water heaters to gas tankless units. The team concluded that the current Energy Factor test procedure overestimates typical use and underestimates the number of hot water draws, which has implications for both equipment and distribution system performance. Gas tankless water heaters were found to impact how people use hot water, but the data does not necessarily suggest an increase in usage. Further study in hot water usage and patterns is needed to better define these characteristics in different climates and home vintages.

  19. Sanitary hot water; Eau chaude sanitaire

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    Cegibat, the information-recommendation agency of Gaz de France for building engineering professionals, has organized this conference meeting on sanitary hot water to present the solutions proposed by Gaz de France to meet its clients requirements in terms of water quality, comfort, energy conservation and respect of the environment: quantitative aspects of the hot water needs, qualitative aspects, presentation of the Dolce Vita offer for residential buildings, gas water heaters and boilers, combined solar-thermal/natural gas solutions, key-specifications of hot water distribution systems, testimony: implementation of a gas hot water reservoir and two accumulation boilers in an apartment building for young workers. (J.S.)

  20. Monitoring of Danish marketed solar heating systems

    International Nuclear Information System (INIS)

    Ellehauge, K.

    1993-01-01

    The paper describes the monitoring of manufactured solar heating systems for domestic hot water combined with space heating and systems for domestic hot water only. Results from the monitoring of 5 marketed combined systems for domestic hot water and space heating are presented. The systems situated at one family houses at different sites in Denmark have been monitored from January/February 1992. For the detailed monitoring of manufactured systems only for domestic hot water a test facility for simultaneous monitoring of 5 solar heating systems has been established at the Thermal Insulation Laboratory. (au)

  1. Energy from solar balloons

    Energy Technology Data Exchange (ETDEWEB)

    Grena, Roberto [C. R. Casaccia, via Anguillarese 301, 00123 Roma (Italy)

    2010-04-15

    Solar balloons are hot air balloons in which the air is heated directly by the sun, by means of a black absorber. The lift force of a tethered solar balloon can be used to produce energy by activating a generator during the ascending motion of the balloon. The hot air is then discharged when the balloon reaches a predefined maximum height. A preliminary study is presented, along with an efficiency estimation and some considerations on possible realistic configurations. (author)

  2. Hot Flow Anomaly formation by magnetic deflection

    International Nuclear Information System (INIS)

    Onsager, T.G.; Thomsen, M.F.; Winske, D.

    1990-01-01

    Hot Flow Anomalies (HFAs) are localized plasma structures observed in the solar wind and magnetosheath near the Earth's quasi-parallel bow shock. The authors present 1-D hybrid computer simulations illustrating a formation mechanism for HFAs in which the single, hot, ion population results from a spatial separation of two counterstreaming ion beams. The higher-density, cooler regions are dominated by the background (solar wind) ions, and the lower-density, hotter, internal regions are dominated by the beam ions. The spatial separation of the beam and background is caused by the deflection of the ions in large amplitude magnetic fields which are generated by ion/ion streaming instabilities

  3. Flipped Heavy Neutrinos from the Solar Neutrino Problem to Baryogenesis

    CERN Document Server

    Ellis, Jonathan Richard; Olive, Keith A

    1993-01-01

    We discuss baryogenesis using the flipped $SU(5)$ model for lepton mass matrices. We show that the generalized see-saw mechanism in this model can not only provide MSW neutrino mixing suitable for solving the solar neutrino problem, and supply a hot dark matter candidate ($\

  4. Economic efficiency of solar hot water policy in New Zealand

    International Nuclear Information System (INIS)

    Gillingham, Kenneth

    2009-01-01

    New Zealand has recently followed the path of several other countries in promoting solar hot water (SHW) systems in the effort to reduce greenhouse gas emissions, yet the economic efficiency of large-scale policies to encourage SHW remains a pressing question for policymakers. This paper develops an economic framework to examine policies to promote SHW in New Zealand, including the current information, training, and subsidy policy. The economic framework points to environmental, energy security, and average-cost electricity retail pricing market failures as motivation for SHW policy, with the global climate change externality the most important of these. The results indicate that domestic SHW systems are close to being financially attractive from a consumer perspective, but a more substantial subsidy policy would be necessary for SHW to appeal to a wider audience. Such a policy is far more likely to have positive net benefits than a policy of mandating SHW on all homes or all new homes in New Zealand, and could be justified on economic efficiency grounds under reasonable assumptions. However, this result reverses under an economy-wide carbon trading system that internalizes the environmental externality.

  5. A feature-based approach to modeling protein-protein interaction hot spots.

    Science.gov (United States)

    Cho, Kyu-il; Kim, Dongsup; Lee, Doheon

    2009-05-01

    Identifying features that effectively represent the energetic contribution of an individual interface residue to the interactions between proteins remains problematic. Here, we present several new features and show that they are more effective than conventional features. By combining the proposed features with conventional features, we develop a predictive model for interaction hot spots. Initially, 54 multifaceted features, composed of different levels of information including structure, sequence and molecular interaction information, are quantified. Then, to identify the best subset of features for predicting hot spots, feature selection is performed using a decision tree. Based on the selected features, a predictive model for hot spots is created using support vector machine (SVM) and tested on an independent test set. Our model shows better overall predictive accuracy than previous methods such as the alanine scanning methods Robetta and FOLDEF, and the knowledge-based method KFC. Subsequent analysis yields several findings about hot spots. As expected, hot spots have a larger relative surface area burial and are more hydrophobic than other residues. Unexpectedly, however, residue conservation displays a rather complicated tendency depending on the types of protein complexes, indicating that this feature is not good for identifying hot spots. Of the selected features, the weighted atomic packing density, relative surface area burial and weighted hydrophobicity are the top 3, with the weighted atomic packing density proving to be the most effective feature for predicting hot spots. Notably, we find that hot spots are closely related to pi-related interactions, especially pi . . . pi interactions.

  6. A feature-based approach to modeling protein–protein interaction hot spots

    Science.gov (United States)

    Cho, Kyu-il; Kim, Dongsup; Lee, Doheon

    2009-01-01

    Identifying features that effectively represent the energetic contribution of an individual interface residue to the interactions between proteins remains problematic. Here, we present several new features and show that they are more effective than conventional features. By combining the proposed features with conventional features, we develop a predictive model for interaction hot spots. Initially, 54 multifaceted features, composed of different levels of information including structure, sequence and molecular interaction information, are quantified. Then, to identify the best subset of features for predicting hot spots, feature selection is performed using a decision tree. Based on the selected features, a predictive model for hot spots is created using support vector machine (SVM) and tested on an independent test set. Our model shows better overall predictive accuracy than previous methods such as the alanine scanning methods Robetta and FOLDEF, and the knowledge-based method KFC. Subsequent analysis yields several findings about hot spots. As expected, hot spots have a larger relative surface area burial and are more hydrophobic than other residues. Unexpectedly, however, residue conservation displays a rather complicated tendency depending on the types of protein complexes, indicating that this feature is not good for identifying hot spots. Of the selected features, the weighted atomic packing density, relative surface area burial and weighted hydrophobicity are the top 3, with the weighted atomic packing density proving to be the most effective feature for predicting hot spots. Notably, we find that hot spots are closely related to π–related interactions, especially π · · · π interactions. PMID:19273533

  7. About the standard solar model

    International Nuclear Information System (INIS)

    Cahen, S.

    1986-07-01

    A discussion of the still controversial solar helium content is presented, based on a comparison of recent standard solar models. Our last model yields an helium mass fraction ∼0.276, 6.4 SNU on 37 Cl and 126 SNU on 71 Ga

  8. Hot News Recommendation System from Heterogeneous Websites Based on Bayesian Model

    Directory of Open Access Journals (Sweden)

    Zhengyou Xia

    2014-01-01

    Full Text Available The most current news recommendations are suitable for news which comes from a single news website, not for news from different heterogeneous news websites. Previous researches about news recommender systems based on different strategies have been proposed to provide news personalization services for online news readers. However, little research work has been reported on utilizing hundreds of heterogeneous news websites to provide top hot news services for group customers (e.g., government staffs. In this paper, we propose a hot news recommendation model based on Bayesian model, which is from hundreds of different news websites. In the model, we determine whether the news is hot news by calculating the joint probability of the news. We evaluate and compare our proposed recommendation model with the results of human experts on the real data sets. Experimental results demonstrate the reliability and effectiveness of our method. We also implement this model in hot news recommendation system of Hangzhou city government in year 2013, which achieves very good results.

  9. Solar Measurement and Modeling | Grid Modernization | NREL

    Science.gov (United States)

    Measurement and Modeling Solar Measurement and Modeling NREL supports grid integration studies , industry, government, and academia by disseminating solar resource measurements, models, and best practices have continuously gathered basic solar radiation information, and they now gather high-resolution data

  10. DESIGN AND ANALYSIS OF THE SNS CCL HOT MODEL WATER COOLING SYSTEM USING THE SINDA/FLUINT NETWORK MODELING TOOL

    Energy Technology Data Exchange (ETDEWEB)

    C. AMMERMAN; J. BERNARDIN

    1999-11-01

    This report presents results for design and analysis of the hot model water cooling system for the Spallation Neutron Source (SNS) coupled-cavity linac (CCL). The hot model, when completed, will include segments for both the CCL and coupled-cavity drift-tube linac (CCDTL). The scope of this report encompasses the modeling effort for the CCL portion of the hot model. This modeling effort employed the SINDA/FLUINT network modeling tool. This report begins with an introduction of the SNS hot model and network modeling using SINDA/FLUINT. Next, the development and operation of the SINDA/FLUINT model are discussed. Finally, the results of the SINDA/FLUINT modeling effort are presented and discussed.

  11. Solar Systems

    Science.gov (United States)

    1979-01-01

    The solar collectors shown are elements of domestic solar hot water systems produced by Solar One Ltd., Virginia Beach, Virginia. Design of these systems benefited from technical expertise provided Solar One by NASA's Langley Research Center. The company obtained a NASA technical support package describing the d e sign and operation of solar heating equipment in NASA's Tech House, a demonstration project in which aerospace and commercial building technology are combined in an energy- efficient home. Solar One received further assistance through personal contact with Langley solar experts. The company reports that the technical information provided by NASA influenced Solar One's panel design, its selection of a long-life panel coating which increases solar collection efficiency, and the method adopted for protecting solar collectors from freezing conditions.

  12. Solar Radiation Model for Development and Control of Solar Energy Sources

    Directory of Open Access Journals (Sweden)

    Dominykas Vasarevičius

    2016-06-01

    Full Text Available The model of solar radiation, which takes into account direct, diffused and reflected components of solar energy, has been presented. Model is associated with geographical coordinates and local time of every day of the year. It is shown that using analytic equations for modelling the direct component, it is possible to adopt it for embedded systems with low computational power and use in solar tracking applications. Reflected and diffused components are especially useful in determining the performance of photovoltaic modules in certain location and surroundings. The statistical method for cloud layer simulation based on local meteorological data is offered. The presented method can’t be used for prediction of weather conditions but it provides patterns of solar radiation in time comparable to those measured with pyranometer. Cloud layer simulation together with total solar radiation model is a useful tool for development and analysis of maximum power point tracking controllers for PV modules.

  13. Homemade Solar Systems

    Science.gov (United States)

    1981-01-01

    Through the use of NASA Tech Briefs, Peter Kask, was able to build a solarized domestic hot water system. Also by applying NASA's solar energy design information, he was able to build a swimming pool heating system with minimal outlay for materials.

  14. Fiscal 1974 Sunshine Project result report. R and D on solar cooling/heating and hot water supply system (R and D on the system for new detached houses); 1994 nendo taiyo reidanbo oyobi kyuto system no kenkyu kaihatsu. Shinchiku kojin jutakuyo system no kenkyu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1975-05-30

    This report describes the fiscal 1974 result on the solar cooling/heating and hot water supply system. The report includes the system analysis result (collection of existing technical data, analysis of weather conditions, profitability assessment, concept design of the primary experimental house), and the research result on equipment and materials (view and evaluation of existing technologies, selective transparent and absorption materials, the primary prototype solar heat collector model, refrigerator). As the study result, the spheroidal experimental house was adopted. The solar heat utilization system is a central air-conditioning equipment composed of heating by hot water obtained from the solar heat collector, and cooling by absorption refrigerator. Heat collection efficiencies were measured for (1) stainless steel substrate collector, (2) copper substrate collector, and (3) glass pipe collector prepared as prototype collectors. (2) was higher in heat collection efficiency than (1). The efficiency of (3) hardly increased by rise in heat collection temperature due to vacuum structure and selective absorption membrane. Further measurement of such characteristics is necessary at higher temperatures. (NEDO)

  15. FY 1977 Annual report on Sunshine Project results. Research and development of solar energy systems for air conditioning and hot water supply (Research and development of solar systems for condominiums); 1977 nendo taiyo reidanbo oyobi kyuto system no kenkyu kaihatsu seika hokokusho. Shugo jutakuyo system no kenkyu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1978-06-01

    This project is aimed at technological development of economical solar energy systems for air conditioning and hot water supply for condominiums. The major items for the FY 1977 programs include (1) designs and fabrication of equipment for a test building, (2) development of the equipment materials, and (3) system analysis. The jobs for item (1) include management of the designs and construction, placing an order for the building, and fabrication of an air conditioner expander and heat pump; those for item (2) include simplification of a condensing type and plate type heat collector structures, weather-resistance of the plate type heat collector structure, and materials for selective absorbing membranes and reflectors; and those for item (3) include estimation of heat loads in a model building, first to third floors as the test building, and fourth to 14th floors as the conventional box-shaped building. The heat collector installation area is investigated for a multistory building, for which solar radiation intensity at the heat-receiving plane and the like are taken into account. It is found that the solar system can be installed, when an area of 50m{sup 2} can be allocated to the system in each story. There is a limit to story number for the solar system to economically work for air conditioning and hot water supply. Sufficient insulation of the system and reduction in pipe length by zoning are the necessary measures against heat losses. (NEDO)

  16. Coronal heating driven by a magnetic gradient pumping mechanism in solar plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Baolin, E-mail: bltan@nao.cas.cn [Key Laboratory of Solar Activity, National Astronomical Observatories of Chinese Academy of Sciences, Beijing 100012 (China)

    2014-11-10

    The heating of the solar corona is a longstanding mystery in astrophysics. Considering that the solar magnetic field is spatially inhomogeneous with a considerable magnetic gradient from the solar surface to the corona, this work proposes a magnetic gradient pumping (MGP) mechanism to try to explain the formation of hot plasma upflows, such as hot type II spicules and hot plasma ejections. In the MGP mechanism, the magnetic gradient may drive the energetic particles to move upward from the underlying solar atmosphere and form hot upflows. These upflow energetic particles are deposited in the corona, causing it to become very hot. Rough estimations indicate that the solar corona can be heated to above 1 million degrees, and the upflow velocity is about 40 km s{sup –1} in the chromosphere and about 130 km s{sup –1} in the corona. The solar magnetic flux tubes act as pumpers to extract energetic particles from the underlying thermal photosphere, convey them, and deposit them in the corona. The deposit of these energetic particles causes the corona to become hot, and the escape of such particles from the photosphere leaves it a bit cold. This mechanism can present a natural explanation to the mystery of solar coronal heating.

  17. Profile in solar

    International Nuclear Information System (INIS)

    Cohen, S.; Woods, A.

    1991-01-01

    This article reviews an innovative solar hot water heater and its inventor/entrepreneur. It includes the inventor's strategy for developing and marketing the product and his ideas on the state of the solar industry in general. There is a brief description of the solar water heater which has as prominent features its skylight-like appearance, resistance to freeze damage, simplicity and low cost

  18. Analysis of Medium-Scale Solar Thermal Systems and Their Potential in Lithuania

    Directory of Open Access Journals (Sweden)

    Rokas Valančius

    2015-06-01

    Full Text Available Medium-scale solar hot water systems with a total solar panel area varying from 60 to 166 m2 have been installed in Lithuania since 2002. However, the performance of these systems varies depending on the type of energy users, equipment and design of the systems, as well as their maintenance. The aim of this paper was to analyse operational SHW systems from the perspective of energy production and economic benefit as well as to outline the differences of their actual performance compared to the numerical simulation results. Three different medium-scale solar thermal systems in Lithuania were selected for the analysis varying in both equipment used (flat type solar collectors, evacuated tube collectors and type of energy user (swimming pool building, domestic hot water heating, district heating. The results of the analysis showed that in the analysed cases the gap between measured and modelled data of heat energy produced by SHW systems was approx. 11%. From the economical perspective, the system with flat type solar collectors used for domestic hot water production was proved to be most efficient. However, calculation of Internal Rate of Return showed that a grant of 35% is required for this project to be fully profitable.

  19. A comparative study on three types of solar utilization technologies for buildings: Photovoltaic, solar thermal and hybrid photovoltaic/thermal systems

    International Nuclear Information System (INIS)

    Huide, Fu; Xuxin, Zhao; Lei, Ma; Tao, Zhang; Qixing, Wu; Hongyuan, Sun

    2017-01-01

    Highlights: • Models of Solar thermal, Photovoltaic and Photovoltaic/thermal systems are developed. • Experiments are performed to validate the simulation results. • Annual performances of the three solar systems used in china are predicted. • Energy comparison between the three solar systems is analyzed. - Abstract: Buildings need energy including heat and electricity, and both of them can be provided by the solar systems. Solar thermal and photovoltaic systems absorb the solar energy and can supply the heat and electricity for buildings, respectively. However, for the urban residential buildings, the limited available area makes installation of the solar thermal collectors and photovoltaic modules together impossible. A hybrid photovoltaic/thermal system can simultaneously generate heat and electricity, which is deemed to be quite suitable for the urban residential buildings application. And yet, for a rural house of China, the available area for installation of the solar collectors is large but daily domestic hot water demand of a rural family is generally not exceeded 300 L. If only the hybrid photovoltaic/thermal collectors are installed on the whole available area, this will lead to an overproduction of the thermal energy, especially in summer. Moreover, buildings requiring for the heat and electricity are different in different regions and different seasons. In this paper, simulation models of the solar thermal, photovoltaic and hybrid photovoltaic/thermal systems are presented, and experiments are also performed to validate the simulation results. Using the validated models, performances of the three solar systems for residential applications were predicted. And energy comparison between the three solar systems used in Hongkong, Lhasa, Shanghai and Beijing of China, respectively, were also studied. Results show that, for the urban residential building with limited available installation space, a hybrid photovoltaic/thermal system may have the

  20. Hybrid solar-PLG system for industrial scale steam and hot water generation; Sistema hibrido solar-GLP para geracao de vapor e agua quente em escala industrial

    Energy Technology Data Exchange (ETDEWEB)

    Saidel, Marco A.; Monteiro, Marcio D.; Gimenes, Andre L.V.; Fujii, Ricardo J. [Universidade de Sao Paulo (GEPEA/EPUSP), SP (Brazil). Dept. Engenharia Energia e Automacao Eletricas. Grupo de Energia], e-mail: saidel@pea.usp.br, e-mail: marcio.monteiro@poli.usp.br, e-mail: gimenes@gmail.com, e-mail: fujii@gmail.com

    2008-07-01

    This paper presents an initiative conceived for attending to objectives of the PUREFA (Program for Rational Use of Energy and Alternative Sources) of the Sao Paulo university, Brazil. The indicative consists of the implantation of a solar collector system for pre-heating of the water used in the production of the steam consumed at the university restaurant, with a production of 5800 meals per day. This system (auxiliary to the original steam boiler) pre-heats the water of the boiler minimizing the energy expenses for the production of steam and hot water.

  1. THERMAL STRATIFICATION IN SOLAR DOMESTIC STORAGE TANKS CAUSED BY DRAW-OFFS

    DEFF Research Database (Denmark)

    Jordan, Ulrike; Furbo, Simon

    2003-01-01

    As shown in many research studies in the past, the thermal stratification of the tank caused by draw-offs has a high impact on the performance of a Solar Domestic Hot Water (SDHW) system. Nevertheless, in most tank models for system simulations the influence of the draw-off pattern on the mixing...... with a component oriented simulation tool for solar thermal systems....

  2. Mathematical modeling of hot air/electrohydrodynamic (EHD) drying kinetics of mushroom slices

    International Nuclear Information System (INIS)

    Taghian Dinani, Somayeh; Hamdami, Nasser; Shahedi, Mohammad; Havet, Michel

    2014-01-01

    Highlights: • Hot air/EHD drying behavior of thin layer mushroom slices was evaluated. • A new empirical model was proposed for drying kinetics modeling of mushroom slices. • The new model presents excellent predictions for hot air/EHD drying of mushroom. - Abstract: Researches about mathematical modeling of electrohydrodynamic (EHD) drying are rare. In this study, hot air combined with electrohydrodynamic (EHD) drying behavior of thin layer mushroom slices was evaluated in a laboratory scale dryer at voltages of 17, 19, and 21 kV and electrode gaps of 5, 6, and 7 cm. The drying curves were fitted to ten different mathematical models (Newton, Page, Modified Page, Henderson and Pabis, Logarithmic, Two-term exponential, Midilli and Kucuk, Wang and Singh, Weibull and Parabolic models) and a proposed new empirical model to select a suitable drying equation for drying mushroom slices in a hot air combined with EHD dryer. Coefficients of the models were determined by non-linear regression analysis and the models were compared based on their coefficient of determination (R 2 ), sum of square errors (SSE) and root mean square error (RMSE) between experimental and predicted moisture ratios. According to the results, the proposed model that contains only three parameters provided the best fit with the experimental data. It was closely followed by the Midilli and Kucuk model that contains four parameters. Therefore, the proposed model can present comfortable usage and excellent predictions for the moisture content changes of mushroom slices in the hot air combined with EHD drying system

  3. Theoretical comparison between solar combisystems based on bikini tanks and tank-in-tank solar combisystems

    DEFF Research Database (Denmark)

    Yazdanshenas, Eshagh; Furbo, Simon; Bales, Chris

    2008-01-01

    Theoretical investigations have shown that solar combisystems based on bikini tanks for low energy houses perform better than solar domestic hot water systems based on mantle tanks. Tank-in-tank solar combisystems are also attractive from a thermal performance point of view. In this paper......, theoretical comparisons between solar combisystems based on bikini tanks and tank-in-tank solar combisystems are presented....

  4. Test and evaluation of Fern Engineering Company, Incorporated, solar heating and hot water system. [structural design criteria and system effectiveness

    Science.gov (United States)

    1979-01-01

    Tests, test results, examination and evaluation by Underwriters Laboratory, Inc., of a single family solar heating and hot water system consisting of collector, storage, control, transport, and data acquisition are presented. The structural characteristics of the solar flat plate collectors were evaluated according to snow and wind loads indicated in various building codes to determine their suitability for use both Michigan and Pennsylvania where prototype systems were installed. The flame spread classification of the thermal insulation is discussed and the fire tests conducted on components are described. The operation and dielectrics withstand tests of the energy transport module indicate the module is capable of rated air delivery. Tests of the control panel indicate the relay coil temperatures exceed the temperature limits allowed for the insulating materials involved.

  5. A method of exploration of the atmosphere of Titan. [hot air balloon heated by solar radiation or planetary thermal flux

    Science.gov (United States)

    Blamont, J.

    1978-01-01

    A hot-air balloon, with the air heated by natural sources, is described. Buoyancy is accomplished by either solar heating or by utilizing the IR thermal flux of the planet to heat the gas in the balloon. Altitude control is provided by a valve which is opened and closed by a barometer. The balloon is made of an organic material which has to absorb radiant energy and to emit as little as possible.

  6. estec2007 - 3rd European solar thermal energy conference. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-12-14

    The sessions of the 'estec2007 - 3{sup rd} European Solar Thermal Energy Conference held in Freiburg, Germany have the following titles: The solar thermal sector at a turning point; Cooling and Process Heat, Country reports Europe; Standards and Certification; Country reports outside Europe; Awareness raising and marketing; Domestic hot water and space heating; Domestic hot water and space heating; Quality Assurance and Solar Thermal Energy Service Companies; Collectors and other key technical issues; Policy - Financial incentives; Country Reports; Marketing and Awareness Raising; Quality Assurance Measures/Monistoring; Standards and Certification; Collectors; Domestic Hot Water and Space Heating; Industrial Process Heat; Storage; Solar Cooling. (AKF)

  7. estec2007 - 3rd European solar thermal energy conference. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-12-14

    The sessions of the 'estec2007 - 3{sup rd} European Solar Thermal Energy Conference held in Freiburg, Germany have the following titles: The solar thermal sector at a turning point; Cooling and Process Heat, Country reports Europe; Standards and Certification; Country reports outside Europe; Awareness raising and marketing; Domestic hot water and space heating; Domestic hot water and space heating; Quality Assurance and Solar Thermal Energy Service Companies; Collectors and other key technical issues; Policy - Financial incentives; Country Reports; Marketing and Awareness Raising; Quality Assurance Measures/Monistoring; Standards and Certification; Collectors; Domestic Hot Water and Space Heating; Industrial Process Heat; Storage; Solar Cooling. (AKF)

  8. The effect of payback time on solar hot water systems diffusion: the case of Greece

    International Nuclear Information System (INIS)

    Sidiras, Dimitrios K.; Koukios, Emmanuel G.

    2005-01-01

    The effect of the payback time on the spectacular diffusion of solar hot water systems (SHWS) in Greece was investigated in this work. The time pattern of the diffusion of flat plate solar collectors since its first appearance in 1974 shows that the diffusion rate grew exponentially at first, with the annual sales figure reaching 185,000 m 2 in the mid-80s. A rapid decline of the growth rate, down to the present annual sales level followed. By the year 2000, more than 2,000,000 m 2 of collectors had been installed. The economic behaviour of the main type of users (households and hotels) was found to have undergone two stages: in one of them, 1978-2002, the change of sales is in agreement with a change in economic feasibility, measured by payback time, while in the other, the early growth stage, 1974-1977, the demand grew despite a negative economic trend, obviously because of non-economic factors. The role of tax deduction, which is the most influential incentive, has been rather instrumental in the growth period 1978-1989, but lost its significance thereafter. This incentive has been withdrawn since the beginning of 1993

  9. The effect of payback time on solar hot water systems diffusion: the case of Greece

    International Nuclear Information System (INIS)

    Sidiras, D.K.; Koukios, E.G.

    2005-01-01

    The effect of the payback time on the spectacular diffusion of solar hot water systems (SHWS) in Greece was investigated in this work. The time pattern of the diffusion of flat plate solar collectors since its first appearance in 1974 shows that the diffusion rate grew exponentially at first, with the annual sales figure reaching 185,000 m 2 in the mid-80s. A rapid decline of the growth rate, down to the present annual sales level followed. By the year 2000, more than 2,000,000 m 2 of collectors had been installed. The economic behaviour of the main type of users (households and hotels) was found to have undergone two stages: in one of them, 1978-2002, the change of sales is in agreement with a change in economic feasibility, measured by payback time, while in the other, the early growth stage, 1974-1977, the demand grew despite a negative economic trend, obviously because of non-economic factors. The role of tax deduction, which is the most influential incentive, has been rather instrumental in the growth period 1978-1989, but lost its significance thereafter. This incentive has been withdrawn since the beginning of 1993. [Author

  10. Modelling and simulations in hot deformation of steels

    International Nuclear Information System (INIS)

    Cabrera, J.M.

    2002-01-01

    Traditionally, hot forming has been employed to provide shape to metals. Nowadays, however, hot working not only produces the desired geometry, but also the mechanical characteristics required. An understanding of the thermomechanical behaviour of metals, and particularly steels, is essential in the simulation and control of the hot forming operations. Moreover, a right prediction of the final properties needs from accurate descriptions of the microstructural features occurring during the shaping step. For this purpose, the determination of constitutive equations describing the stress σ - strain ε relationships at a given strain rate ε, temperature T and initial microstructure, is a useful task. In this sense, computer simulations of hot working processes proportionate a benchmark to engineers and researchers and allow decreasing the cost of developing products and processes. With regard to the prediction of the final microstructure, the simulation of the hot plastic deformation usually gives unsatisfactory results. This is due to the inadequate constitutive equations employed by the conventional and commercial software available to describe the hot flow behaviour. There are scarce models which couple the typical hot working variables (temperature, strain and strain rate) with microstructural characteristics such as grain size. In this review work is presented how the latter limitation can be overcome by using physical-based constitutive equations, some of which have been partially developed by the present authors, where account of the interaction between microstructure and processing variables is taken. Moreover, a practical derivation of the latter expressions on an AISI-304 steel is presented. To conclude, some examples of industrial applications of the latter approach are also presented. Copyright (2002) AD-TECH - International Foundation for the Advancement of Technology Ltd

  11. There is no bidirectional hot-spot in Sentinel-2 data

    Science.gov (United States)

    Li, Z.; Roy, D. P.; Zhang, H.

    2017-12-01

    The Sentinel-2 multi-spectral instrument (MSI) acquires reflective wavelength observations with directional effects due to surface reflectance anisotropy, often described by the bidirectional reflectance distribution function (BRDF). Recently, we quantified Sentinel-2A (S2A) BRDF effects for 20° × 10° of southern Africa sensed in January and in April 2016 and found maximum BRDF effects for the January data and at the western scan edge, i.e., in the back-scatter direction (Roy et al. 2017). The hot-spot is the term used to describe the increased directional reflectance that occurs over most surfaces when the solar and viewing directions coincide, and has been observed in wide-field of view data such as MODIS. Recently, we observed that Landsat data will not have a hot-spot because the global annual minimum solar zenith angle is more than twice the maximum view zenith angle (Zhang et al. 2016). This presentation examines if there is a S2A hot-spot which may be possible as it has a wider field of view (20.6°) and higher orbit (786 km) than Landsat. We examined a global year of S2A metadata extracted using the Committee on Earth Observation Satellite Visualization Environment (COVE) tool, computed the solar zenith angles in the acquisition corners, and ranked the acquisitions by the solar zenith angle in the back-scatter direction. The available image data for the 10 acquisitions with the smallest solar zenith angle over the year were ordered from the ESA and their geometries examined in detail. The acquisition closest to the hot-spot had a maximum scattering angle of 173.61° on its western edge (view zenith angle 11.91°, solar zenith angle 17.97°) and was acquired over 60.80°W 24.37°N on June 2nd 2016. Given that hot-spots are only apparent when the scattering angle is close to 180° we conclude from this global annual analysis that there is no hot-spot in Sentinel-2 data. Roy, D.P, Li, J., Zhang, H.K., Yan, L., Huang, H., Li, Z., 2017, Examination of

  12. Verification of high-speed solar wind stream forecasts using operational solar wind models

    DEFF Research Database (Denmark)

    Reiss, Martin A.; Temmer, Manuela; Veronig, Astrid M.

    2016-01-01

    and the background solar wind conditions. We found that both solar wind models are capable of predicting the large-scale features of the observed solar wind speed (root-mean-square error, RMSE ≈100 km/s) but tend to either overestimate (ESWF) or underestimate (WSA) the number of high-speed solar wind streams (threat......High-speed solar wind streams emanating from coronal holes are frequently impinging on the Earth's magnetosphere causing recurrent, medium-level geomagnetic storm activity. Modeling high-speed solar wind streams is thus an essential element of successful space weather forecasting. Here we evaluate...... high-speed stream forecasts made by the empirical solar wind forecast (ESWF) and the semiempirical Wang-Sheeley-Arge (WSA) model based on the in situ plasma measurements from the Advanced Composition Explorer (ACE) spacecraft for the years 2011 to 2014. While the ESWF makes use of an empirical relation...

  13. Ionospheric hot spot at high latitudes

    International Nuclear Information System (INIS)

    Schunk, R.W.; Sojka, J.J.

    1982-01-01

    A hot spot (or spots) can occur in the high-latitude ionosphere depending on the plasma convection pattern. The hot spot corresponds to a small magnetic local time-magnetic latitude region of elevated ion temperatures located near the dusk and/or dawn meridians. For asymmetric convection electric field patterns, with enhanced flow in either the dusk or dawn sector of the polar cap, a single hot spot should occur in association with the strong convection cell. However, on geomagnetically disturbed days, two strong convection cells can occur, and hence, two hot spots should exist. The hot spot should be detectable when the electric field in the strong convection cell exceeds about 40 mV m -1 . For electric fields of the order of 100 mV m -1 in the convection cell, the ion temperature in the hot spot is greatest at low altitudes, reaching 4000 0 K at 160 km, and decreases with altitude in the F-region. An ionospheric hot spot (or spots) can be expected at all seasons and for a wide range of solar cycle conditions

  14. Models of diffuse solar radiation

    Energy Technology Data Exchange (ETDEWEB)

    Boland, John; Ridley, Barbara [Centre for Industrial and Applied Mathematics, University of South Australia, Mawson Lakes Boulevard, Mawson Lakes, SA 5095 (Australia); Brown, Bruce [Department of Statistics and Applied Probability, National University of Singapore, Singapore 117546 (Singapore)

    2008-04-15

    For some locations both global and diffuse solar radiation are measured. However, for many locations, only global is measured, or inferred from satellite data. For modelling solar energy applications, the amount of radiation on a tilted surface is needed. Since only the direct component on a tilted surface can be calculated from trigonometry, we need to have diffuse on the horizontal available. There are regression relationships for estimating the diffuse on a tilted surface from diffuse on the horizontal. Models for estimating the diffuse radiation on the horizontal from horizontal global that have been developed in Europe or North America have proved to be inadequate for Australia [Spencer JW. A comparison of methods for estimating hourly diffuse solar radiation from global solar radiation. Sol Energy 1982; 29(1): 19-32]. Boland et al. [Modelling the diffuse fraction of global solar radiation on a horizontal surface. Environmetrics 2001; 12: 103-16] developed a validated model for Australian conditions. We detail our recent advances in developing the theoretical framework for the approach reported therein, particularly the use of the logistic function instead of piecewise linear or simple nonlinear functions. Additionally, we have also constructed a method, using quadratic programming, for identifying values that are likely to be erroneous. This allows us to eliminate outliers in diffuse radiation values, the data most prone to errors in measurement. (author)

  15. Hawaii Solar Integration Study: Solar Modeling Developments and Study Results; Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Orwig, K.; Corbus, D.; Piwko, R.; Schuerger, M.; Matsuura, M.; Roose, L.

    2012-12-01

    The Hawaii Solar Integration Study (HSIS) is a follow-up to the Oahu Wind Integration and Transmission Study completed in 2010. HSIS focuses on the impacts of higher penetrations of solar energy on the electrical grid and on other generation. HSIS goes beyond the island of Oahu and investigates Maui as well. The study examines reserve strategies, impacts on thermal unit commitment and dispatch, utilization of energy storage, renewable energy curtailment, and other aspects of grid reliability and operation. For the study, high-frequency (2-second) solar power profiles were generated using a new combined Numerical Weather Prediction model/ stochastic-kinematic cloud model approach, which represents the 'sharp-edge' effects of clouds passing over solar facilities. As part of the validation process, the solar data was evaluated using a variety of analysis techniques including wavelets, power spectral densities, ramp distributions, extreme values, and cross correlations. This paper provides an overview of the study objectives, results of the solar profile validation, and study results.

  16. Solar-energy heats a transportation test center--Pueblo, Colorado

    Science.gov (United States)

    1981-01-01

    Petroleum-base, thermal energy transport fluid circulating through 583 square feet of flat-plate solar collectors accumulates majority of energy for space heating and domestic hot-water of large Test Center. Report describes operation, maintenance, and performance of system which is suitable for warehouses and similar buildings. For test period from February 1979 to January 1980, solar-heating fraction was 31 percent, solar hot-water fraction 79 percent.

  17. Fluid circulating pump operated by same incident solar energy which heats energy collection fluid

    Science.gov (United States)

    Collins, E. R.

    1980-01-01

    The application of using a spacecraft solar powered pump terrestrially to reduce or eliminate the need for fossil fuel generated electricity for domestic solar hot water systems was investigated. A breadboard prototype model was constructed utilizing bimetals to convert thermal energy into mechanical motion by means of a toggle operated shutter mechanism. Although it did not meet expected thermal efficiency, the prototype model was sufficient to demonstrate the mechanical concept.

  18. Solar Water-Heater Design Package

    Science.gov (United States)

    1982-01-01

    Information on a solar domestic-hot water heater is contained in 146 page design package. System consists of solar collector, storage tanks, automatic control circuitry and auxiliary heater. Data-acquisition equipment at sites monitors day-by-day performance. Includes performance specifications, schematics, solar-collector drawings and drawings of control parts.

  19. SolarOil Project, Phase I preliminary design report. [Solar Thermal Enhanced Oil Recovery project

    Energy Technology Data Exchange (ETDEWEB)

    Baccaglini, G.; Bass, J.; Neill, J.; Nicolayeff, V.; Openshaw, F.

    1980-03-01

    The preliminary design of the Solar Thermal Enhanced Oil Recovery (SolarOil) Plant is described in this document. This plant is designed to demonstrate that using solar thermal energy is technically feasible and economically viable in enhanced oil recovery (EOR). The SolarOil Plant uses the fixed mirror solar concentrator (FMSC) to heat high thermal capacity oil (MCS-2046) to 322/sup 0/C (611/sup 0/F). The hot fluid is pumped from a hot oil storage tank (20 min capacity) through a once-through steam generator which produces 4.8 MPa (700 psi) steam at 80% quality. The plant net output, averaged over 24 hr/day for 365 days/yr, is equivalent to that of a 2.4 MW (8.33 x 10/sup 6/ Btu/hr) oil-fired steam generator having an 86% availability. The net plant efficiency is 57.3% at equinox noon, a 30%/yr average. The plant will be demonstrated at an oilfield site near Oildale, California.

  20. Liquid-Crystal Display (LCD) Screen Thermal Testing to Simulate Solar Gain

    Science.gov (United States)

    2015-12-01

    determined that shielding the screen from solar gains was the best way to avoid monitor failure. In order to accomplish this Hot Mirror glass from...side of the monitor in order to shield the monitor from the solar loading. 2.7 Test 7 – Bench Test with a 250 W Heat Lamp and Hot Mirror Glass , 1 Inch...method to shield the screen from solar loading. The Hot Mirror glass uses a glass substrate with a coating on 1 side that passes visible light, but

  1. PROBABILITY OF CME IMPACT ON EXOPLANETS ORBITING M DWARFS AND SOLAR-LIKE STARS

    Energy Technology Data Exchange (ETDEWEB)

    Kay, C. [Solar Physics Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Opher, M.; Kornbleuth, M., E-mail: ckay@bu.edu [Astronomy Department, Boston University, Boston, MA 02215 (United States)

    2016-08-01

    Solar coronal mass ejections (CMEs) produce adverse space weather effects at Earth. Planets in the close habitable zone of magnetically active M dwarfs may experience more extreme space weather than at Earth, including frequent CME impacts leading to atmospheric erosion and leaving the surface exposed to extreme flare activity. Similar erosion may occur for hot Jupiters with close orbits around solar-like stars. We have developed a model, Forecasting a CME's Altered Trajectory (ForeCAT), which predicts a CME's deflection. We adapt ForeCAT to simulate CME deflections for the mid-type M dwarf V374 Peg and hot Jupiters with solar-type hosts. V374 Peg's strong magnetic fields can trap CMEs at the M dwarfs's Astrospheric Current Sheet, that is, the location of the minimum in the background magnetic field. Solar-type CMEs behave similarly, but have much smaller deflections and do not become trapped at the Astrospheric Current Sheet. The probability of planetary impact decreases with increasing inclination of the planetary orbit with respect to the Astrospheric Current Sheet: 0.5–5 CME impacts per day for M dwarf exoplanets, 0.05–0.5 CME impacts per day for solar-type hot Jupiters. We determine the minimum planetary magnetic field necessary to shield a planet's atmosphere from CME impacts. M dwarf exoplanets require values between tens and hundreds of Gauss. Hot Jupiters around a solar-type star, however, require a more reasonable <30 G. These values exceed the magnitude required to shield a planet from the stellar wind, suggesting that CMEs may be the key driver of atmospheric losses.

  2. PROBABILITY OF CME IMPACT ON EXOPLANETS ORBITING M DWARFS AND SOLAR-LIKE STARS

    International Nuclear Information System (INIS)

    Kay, C.; Opher, M.; Kornbleuth, M.

    2016-01-01

    Solar coronal mass ejections (CMEs) produce adverse space weather effects at Earth. Planets in the close habitable zone of magnetically active M dwarfs may experience more extreme space weather than at Earth, including frequent CME impacts leading to atmospheric erosion and leaving the surface exposed to extreme flare activity. Similar erosion may occur for hot Jupiters with close orbits around solar-like stars. We have developed a model, Forecasting a CME's Altered Trajectory (ForeCAT), which predicts a CME's deflection. We adapt ForeCAT to simulate CME deflections for the mid-type M dwarf V374 Peg and hot Jupiters with solar-type hosts. V374 Peg's strong magnetic fields can trap CMEs at the M dwarfs's Astrospheric Current Sheet, that is, the location of the minimum in the background magnetic field. Solar-type CMEs behave similarly, but have much smaller deflections and do not become trapped at the Astrospheric Current Sheet. The probability of planetary impact decreases with increasing inclination of the planetary orbit with respect to the Astrospheric Current Sheet: 0.5–5 CME impacts per day for M dwarf exoplanets, 0.05–0.5 CME impacts per day for solar-type hot Jupiters. We determine the minimum planetary magnetic field necessary to shield a planet's atmosphere from CME impacts. M dwarf exoplanets require values between tens and hundreds of Gauss. Hot Jupiters around a solar-type star, however, require a more reasonable <30 G. These values exceed the magnitude required to shield a planet from the stellar wind, suggesting that CMEs may be the key driver of atmospheric losses.

  3. Performance optimization of evacuated tube collector for solar cooling of a house in hot climate

    Science.gov (United States)

    Ghoneim, Adel A.

    2018-02-01

    Evacuating the space connecting cover and absorber significantly improves evacuated tube collector (ETC) performance. So, ETCs are progressively utilised all over the world. The main goal of current study is to explore ETC thermal efficiency in hot and severe climate like Kuwait weather conditions. A collector test facility was installed to record ETC thermal performance for one-year period. An extensively developed model for ETCs is presented, employing complete optical and thermal assessment. This study analyses separately optics and heat transfer in the evacuated tubes, allowing the analysis to be extended to different configurations. The predictions obtained are in agreement with experimental. The optimum collector parameters (collector tube length and diameter, mass flow rate and collector tilt angle) are determined. The present results indicate that the optimum tube length is 1.5 m, as at this length a significant improvement is achieved in efficiency for different tube diameters studied. Finally, the heat generated from ETCs is used for solar cooling of a house. Results of the simulation of cooling system indicate that an ETC of area 54 m2, tilt angle of 25° and storage tank volume of 2.1 m3 provides 80% of air-conditioning demand in a house located in Kuwait.

  4. Hot-electron-based solar energy conversion with metal-semiconductor nanodiodes

    Science.gov (United States)

    Lee, Young Keun; Lee, Hyosun; Lee, Changhwan; Hwang, Euyheon; Park, Jeong Young

    2016-06-01

    Energy dissipation at metal surfaces or interfaces between a metal and a dielectric generally results from elementary excitations, including phonons and electronic excitation, once external energy is deposited to the surface/interface during exothermic chemical processes or an electromagnetic wave incident. In this paper, we outline recent research activities to develop energy conversion devices based on hot electrons. We found that photon energy can be directly converted to hot electrons and that hot electrons flow through the interface of metal-semiconductor nanodiodes where a Schottky barrier is formed and the energy barrier is much lower than the work function of the metal. The detection of hot electron flow can be successfully measured using the photocurrent; we measured the photoyield of photoemission with incident photons-to-current conversion efficiency (IPCE). We also show that surface plasmons (i.e. the collective oscillation of conduction band electrons induced by interaction with an electromagnetic field) are excited on a rough metal surface and subsequently decay into secondary electrons, which gives rise to enhancement of the IPCE. Furthermore, the unique optical behavior of surface plasmons can be coupled with dye molecules, suggesting the possibility for producing additional channels for hot electron generation.

  5. Qualification test and analysis report: solar collectors

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-01

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

  6. Climate classification and passive solar design implications in China

    Energy Technology Data Exchange (ETDEWEB)

    Lau, Chris C.S.; Lam, Joseph C. [Building Energy Research Group, Department of Building and Construction, City University of Hong Kong, Kowloon, Hong Kong (China); Yang, Liu [School of Architecture, Xi' an University of Architecture and Technology, Shaanxi 710055 (China)

    2007-07-15

    China's climate differs greatly in various regions, ranging from severe cold to hot and arid to humid. This has significant influences on energy efficient building design strategies and energy use. Solar radiation data from 123 measuring stations were used to propose a map indicating the solar radiation climates in China. A cluster analysis was adopted to identify the prevailing solar climates using the monthly average daily clearness index, K{sub t}, as climatic variable. Five major solar climates were identified with annual average K{sub t} ranging from 0.3 in the Sichuan Basin to 0.65 in the north and northwest regions. The solar climates were compared with the more widely used general (thermal) climates (severe cold, cold, hot summer and cold winter, mild and hot summer and warm winter) and the major topography (basin, plain and plateau), and implications for building designs were briefly discussed. (author)

  7. Climate classification and passive solar design implications in China

    International Nuclear Information System (INIS)

    Lau, Chris C.S.; Lam, Joseph C.; Yang, Liu

    2007-01-01

    China's climate differs greatly in various regions, ranging from severe cold to hot and arid to humid. This has significant influences on energy efficient building design strategies and energy use. Solar radiation data from 123 measuring stations were used to propose a map indicating the solar radiation climates in China. A cluster analysis was adopted to identify the prevailing solar climates using the monthly average daily clearness index, K t , as climatic variable. Five major solar climates were identified with annual average K t ranging from 0.3 in the Sichuan Basin to 0.65 in the north and northwest regions. The solar climates were compared with the more widely used general (thermal) climates (severe cold, cold, hot summer and cold winter, mild and hot summer and warm winter) and the major topography (basin, plain and plateau), and implications for building designs were briefly discussed

  8. Solar Advisor Model User Guide for Version 2.0

    Energy Technology Data Exchange (ETDEWEB)

    Gilman, P.; Blair, N.; Mehos, M.; Christensen, C.; Janzou, S.; Cameron, C.

    2008-08-01

    The Solar Advisor Model (SAM) provides a consistent framework for analyzing and comparing power system costs and performance across the range of solar technologies and markets, from photovoltaic systems for residential and commercial markets to concentrating solar power and large photovoltaic systems for utility markets. This manual describes Version 2.0 of the software, which can model photovoltaic and concentrating solar power technologies for electric applications for several markets. The current version of the Solar Advisor Model does not model solar heating and lighting technologies.

  9. Study of solar radiation prediction and modeling of relationships between solar radiation and meteorological variables

    International Nuclear Information System (INIS)

    Sun, Huaiwei; Zhao, Na; Zeng, Xiaofan; Yan, Dong

    2015-01-01

    Highlights: • We investigate relationships between solar radiation and meteorological variables. • A strong relationship exists between solar radiation and sunshine duration. • Daily global radiation can be estimated accurately with ARMAX–GARCH models. • MGARCH model was applied to investigate time-varying relationships. - Abstract: The traditional approaches that employ the correlations between solar radiation and other measured meteorological variables are commonly utilized in studies. It is important to investigate the time-varying relationships between meteorological variables and solar radiation to determine which variables have the strongest correlations with solar radiation. In this study, the nonlinear autoregressive moving average with exogenous variable–generalized autoregressive conditional heteroscedasticity (ARMAX–GARCH) and multivariate GARCH (MGARCH) time-series approaches were applied to investigate the associations between solar radiation and several meteorological variables. For these investigations, the long-term daily global solar radiation series measured at three stations from January 1, 2004 until December 31, 2007 were used in this study. Stronger relationships were observed to exist between global solar radiation and sunshine duration than between solar radiation and temperature difference. The results show that 82–88% of the temporal variations of the global solar radiation were captured by the sunshine-duration-based ARMAX–GARCH models and 55–68% of daily variations were captured by the temperature-difference-based ARMAX–GARCH models. The advantages of the ARMAX–GARCH models were also confirmed by comparison of Auto-Regressive and Moving Average (ARMA) and neutral network (ANN) models in the estimation of daily global solar radiation. The strong heteroscedastic persistency of the global solar radiation series was revealed by the AutoRegressive Conditional Heteroscedasticity (ARCH) and Generalized Auto

  10. Possibilities of utilizing solar systems for heating the hot service water in Košice build-up areas KVP and Ťahanovce

    Directory of Open Access Journals (Sweden)

    Peter Horbaj

    2005-12-01

    Full Text Available A production of „HSW“ in block of flats areas by solar collectors means a real alternative to the traditional way of heating by fossil fuels (coal, gas. With this method, it’s possible to save ca. 50 % of energy from the net of the central service of the heat, what can reduce the production of pollutants in the locality, or it can enable to increase the quantity of customers without claims for the restructuralization of the central source. Because Slovakia is the producer of quality solar collectors it’s suitable to use them just for this reason, which could be projected into the price reduction of relatively expensive present systems. On the other side, when using the flat roofs on the block of flats, other useful places are hot occupied and the heating source is nearby the place of it sconsumption. In this case, a collaboration of the solar system and the Central Service of Heat is especially suitable in time with a shortage of the solar radiation.

  11. Evaluation of global solar radiation models for Shanghai, China

    International Nuclear Information System (INIS)

    Yao, Wanxiang; Li, Zhengrong; Wang, Yuyan; Jiang, Fujian; Hu, Lingzhou

    2014-01-01

    Highlights: • 108 existing models are compared and analyzed by 42 years meteorological data. • Fitting models based on measured data are established according to 42 years data. • All models are compared by recently 10 years meteorological data. • The results show that polynomial models are the most accurate models. - Abstract: In this paper, 89 existing monthly average daily global solar radiation models and 19 existing daily global solar radiation models are compared and analyzed by 42 years meteorological data. The results show that for existing monthly average daily global solar radiation models, linear models and polynomial models have been able to estimate global solar radiation accurately, and complex equation types cannot obviously improve the precision. Considering direct parameters such as latitude, altitude, solar altitude and sunshine duration can help improve the accuracy of the models, but indirect parameters cannot. For existing daily global solar radiation models, multi-parameter models are more accurate than single-parameter models, polynomial models are more accurate than linear models. Then measured data fitting monthly average daily global solar radiation models (MADGSR models) and daily global solar radiation models (DGSR models) are established according to 42 years meteorological data. Finally, existing models and fitting models based on measured data are comparative analysis by recent 10 years meteorological data, and the results show that polynomial models (MADGSR model 2, DGSR model 2 and Maduekwe model 2) are the most accurate models

  12. Technology Learning Activities. Design Brief--Measuring Inaccessible Distances. Alternative Energy Sources: Designing a Wind Powered Generator. Alternative Energy Sources: Designing a Hot Dog Heater Using Solar Energy.

    Science.gov (United States)

    Technology Teacher, 1991

    1991-01-01

    These three learning activities are on measuring accessible distances, designing a wind powered generator, and designing a hot dog heater using solar energy. Each activity includes description of context, objectives, list of materials and equipment, challenge to students, and evaluation questions. (SK)

  13. Residential solar-heating system

    Science.gov (United States)

    1978-01-01

    Complete residential solar-heating and hot-water system, when installed in highly-insulated energy-saver home, can supply large percentage of total energy demand for space heating and domestic hot water. System which uses water-heating energy storage can be scaled to meet requirements of building in which it is installed.

  14. Measurements and modeling of total solar irradiance in X-class solar flares

    International Nuclear Information System (INIS)

    Moore, Christopher Samuel; Chamberlin, Phillip Clyde; Hock, Rachel

    2014-01-01

    The Total Irradiance Monitor (TIM) from NASA's SOlar Radiation and Climate Experiment can detect changes in the total solar irradiance (TSI) to a precision of 2 ppm, allowing observations of variations due to the largest X-class solar flares for the first time. Presented here is a robust algorithm for determining the radiative output in the TIM TSI measurements, in both the impulsive and gradual phases, for the four solar flares presented in Woods et al., as well as an additional flare measured on 2006 December 6. The radiative outputs for both phases of these five flares are then compared to the vacuum ultraviolet (VUV) irradiance output from the Flare Irradiance Spectral Model (FISM) in order to derive an empirical relationship between the FISM VUV model and the TIM TSI data output to estimate the TSI radiative output for eight other X-class flares. This model provides the basis for the bolometric energy estimates for the solar flares analyzed in the Emslie et al. study.

  15. Solar energy system performance evaluation: Seasonal report for IBM System 1B, Carlsbad, New Mexico

    Science.gov (United States)

    1980-01-01

    A hot solar heating and hot water system's operational performance from April 1979 through March 1980 is evaluated. The space heating and hot water loads were near expected values for the year. Solar energy provided 43 percent of the space heating and 53 percent of the hot water energy. The system did not meet the total system solar fraction design value of 69 percent because of a combination of higher estimated space heating load than was actually encountered and the apportioning of solar energy between the space heating and the domestic hot water loads. System losses and high building temperatures also contributed to this deviation. Total net savings were 23.072 million BTUs. Most of the energy savings came during the winter months, but hot water savings were sufficient to justify running the system during the summer months.

  16. Mars Solar Balloon Lander, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The Mars Solar Balloon Lander (MSBL) is a novel concept which utilizes the capability of solar-heated hot air balloons to perform soft landings of scientific...

  17. Tandem solar cells deposited using hot-wire chemical vapor deposition

    NARCIS (Netherlands)

    Veen, M.K. van

    2003-01-01

    In this thesis, the application of the hot-wire chemical vapor deposition (HWCVD) technique for the deposition of silicon thin films is described. The HWCVD technique is based on the dissociation of silicon-containing gasses at the catalytic surface of a hot filament. Advantages of this technique

  18. Validation of a simulation method for forced circulation type of solar domestic hot water heating systems; Kyosei junkangata taiyonetsu kyuto system simulation hoho no kensho

    Energy Technology Data Exchange (ETDEWEB)

    Sato, M; Udagawa, M [Kogakuin University, Tokyo (Japan); Matsumoto, T [Yazaki Corp., Tokyo (Japan)

    1996-10-27

    Simulation of solar hot water systems using element model was conducted, in which computation of the convergence of apparatus characteristic values was performed every hour. For each apparatus, the outlet temperature was made a function of the inlet temperature on the basis of the heat balance, from which a simultaneous equation was derived and then solved for the determination of the outlet temperature for the computation of the quantity of heat collected by each apparatus. The actually measured system comprises a planar solar collector, heat storage tank, and heat collector piping. The measurement involved a direct heat collecting system with the medium running from the heat storage tank bottom layer, through the solar collector, and then back to the heat storage tank third layer, and an indirect heat collector system with a heat exchanger provided at the heat storage tank bottom layer. There was no substantial difference between the direct type and the indirect type with respect to the solar collector inlet and outlet temperatures, quantity of heat collected, and the fluctuation in heat storage tank inside temperature distribution relative to time. Difference occurred between the two in tank water temperature distribution, however, when water was extracted in great volume at a time. The quantity of the heat collected by each of the two and the daily integration of the same differed but a little from computed values. 4 refs., 6 figs., 4 tabs.

  19. A model for solar constant secular changes

    Science.gov (United States)

    Schatten, Kenneth H.

    1988-01-01

    In this paper, contrast models for solar active region and global photospheric features are used to reproduce the observed Active Cavity Radiometer and Earth Radiation Budget secular trends in reasonably good fashion. A prediction for the next decade of solar constant variations is made using the model. Secular trends in the solar constant obtained from the present model support the view that the Maunder Minimum may be related to the Little Ice Age of the 17th century.

  20. Solar space and water heating system installed at Charlottesville, Virginia

    Science.gov (United States)

    1980-01-01

    The solar energy system located at David C. Wilson Neuropsychiatric Hospital, Charlottesville, Virginia, is described. The solar energy system consists of 88 single glazed, Sunworks 'Solector' copper base plate collector modules, hot water coils in the hot air ducts, a Domestic Hot Water (DHW) preheat tank, a 3,000 gallon concrete urethane insulated storage tank and other miscellaneous components. Extracts from the site files, specifications, drawings, installation, operation and maintenance instructions are included.

  1. Solar Water Heater Installation Package

    Science.gov (United States)

    1982-01-01

    A 48-page report describes water-heating system, installation (covering collector orientation, mounting, plumbing and wiring), operating instructions and maintenance procedures. Commercial solar-powered water heater system consists of a solar collector, solar-heated-water tank, electrically heated water tank and controls. Analysis of possible hazards from pressure, electricity, toxicity, flammability, gas, hot water and steam are also included.

  2. Finite-Time Thermoeconomic Optimization of a Solar-Driven Heat Engine Model

    Directory of Open Access Journals (Sweden)

    Fernando Angulo-Brown

    2011-01-01

    Full Text Available In the present paper, the thermoeconomic optimization of an irreversible solar-driven heat engine model has been carried out by using finite-time/finite-size thermodynamic theory. In our study we take into account losses due to heat transfer across finite time temperature differences, heat leakage between thermal reservoirs and internal irreversibilities in terms of a parameter which comes from the Clausius inequality. In the considered heat engine model, the heat transfer from the hot reservoir to the working fluid is assumed to be Dulong-Petit type and the heat transfer to the cold reservoir is assumed of the Newtonian type. In this work, the optimum performance and two design parameters have been investigated under two objective functions: the power output per unit total cost and the ecological function per unit total cost. The effects of the technical and economical parameters on the thermoeconomic performance have been also discussed under the aforementioned two criteria of performance.

  3. Validated TRNSYS Model for Solar Assisted Space Heating System

    International Nuclear Information System (INIS)

    Abdalla, Nedal

    2014-01-01

    The present study involves a validated TRNSYS model for solar assisted space heating system as applied to a residential building in Jordan using new detailed radiation models of the TRNSYS 17.1 and geometric building model Trnsys3d for the Google SketchUp 3D drawing program. The annual heating load for a building (Solar House) which is located at the Royal ScientiFIc Society (RS5) in Jordan is estimated under climatological conditions of Amman. The aim of this Paper is to compare measured thermal performance of the Solar House with that modeled using TRNSYS. The results showed that the annual measured space heating load for the building was 6,188 kWh while the heati.ng load for the modeled building was 6,391 kWh. Moreover, the measured solar fraction for the solar system was 50% while the modeled solar fraction was 55%. A comparison of modeled and measured data resulted in percentage mean absolute errors for solar energy for space heating, auxiliary heating and solar fraction of 13%, 7% and 10%, respectively. The validated model will be useful for long-term performance simulation under different weather and operating conditions.(author)

  4. A temperature dependent cyclic plasticity model for hot work tool steel including particle coarsening

    Science.gov (United States)

    Jilg, Andreas; Seifert, Thomas

    2018-05-01

    Hot work tools are subjected to complex thermal and mechanical loads during hot forming processes. Locally, the stresses can exceed the material's yield strength in highly loaded areas as e.g. in small radii in die cavities. To sustain the high loads, the hot forming tools are typically made of martensitic hot work steels. While temperatures for annealing of the tool steels usually lie in the range between 400 and 600 °C, the steels may experience even higher temperatures during hot forming, resulting in softening of the material due to coarsening of strengthening particles. In this paper, a temperature dependent cyclic plasticity model for the martensitic hot work tool steel 1.2367 (X38CrMoV5-3) is presented that includes softening due to particle coarsening and that can be applied in finite-element calculations to assess the effect of softening on the thermomechanical fatigue life of hot work tools. To this end, a kinetic model for the evolution of the mean size of secondary carbides based on Ostwald ripening is coupled with a cyclic plasticity model with kinematic hardening. Mechanism-based relations are developed to describe the dependency of the mechanical properties on carbide size and temperature. The material properties of the mechanical and kinetic model are determined on the basis of tempering hardness curves as well as monotonic and cyclic tests.

  5. Solar radiation modeling and measurements for renewable energy applications: data and model quality

    International Nuclear Information System (INIS)

    Myers, Daryl R.

    2005-01-01

    Measurement and modeling of broadband and spectral terrestrial solar radiation is important for the evaluation and deployment of solar renewable energy systems. We discuss recent developments in the calibration of broadband solar radiometric instrumentation and improving broadband solar radiation measurement accuracy. An improved diffuse sky reference and radiometer calibration and characterization software for outdoor pyranometer calibrations are outlined. Several broadband solar radiation model approaches, including some developed at the National Renewable Energy Laboratory, for estimating direct beam, total hemispherical and diffuse sky radiation are briefly reviewed. The latter include the Bird clear sky model for global, direct beam, and diffuse terrestrial solar radiation; the Direct Insolation Simulation Code (DISC) for estimating direct beam radiation from global measurements; and the METSTAT (Meteorological and Statistical) and Climatological Solar Radiation (CSR) models that estimate solar radiation from meteorological data. We conclude that currently the best model uncertainties are representative of the uncertainty in measured data

  6. Solar radiation modeling and measurements for renewable energy applications: data and model quality

    Energy Technology Data Exchange (ETDEWEB)

    Myers, D.R. [National Renewable Energy Laboratory, Golden, CO (United States)

    2005-07-01

    Measurement and modeling of broadband and spectral terrestrial solar radiation is important for the evaluation and deployment of solar renewable energy systems. We discuss recent developments in the calibration of broadband solar radiometric instrumentation and improving broadband solar radiation measurement accuracy. An improved diffuse sky reference and radiometer calibration and characterization software for outdoor pyranometer calibrations are outlined. Several broadband solar radiation model approaches, including some developed at the National Renewable Energy Laboratory, for estimating direct beam, total hemispherical and diffuse sky radiation are briefly reviewed. The latter include the Bird clear sky model for global, direct beam, and diffuse terrestrial solar radiation; the Direct Insolation Simulation Code (DISC) for estimating direct beam radiation from global measurements; and the METSTAT (Meteorological and Statistical) and Climatological Solar Radiation (CSR) models that estimate solar radiation from meteorological data. We conclude that currently the best model uncertainties are representative of the uncertainty in measured data. (author)

  7. Numerical Simulations of Multiphase Winds and Fountains from Star-forming Galactic Disks. I. Solar Neighborhood TIGRESS Model

    Science.gov (United States)

    Kim, Chang-Goo; Ostriker, Eve C.

    2018-02-01

    Gas blown away from galactic disks by supernova (SN) feedback plays a key role in galaxy evolution. We investigate outflows utilizing the solar neighborhood model of our high-resolution, local galactic disk simulation suite, TIGRESS. In our numerical implementation, star formation and SN feedback are self-consistently treated and well resolved in the multiphase, turbulent, magnetized interstellar medium. Bursts of star formation produce spatially and temporally correlated SNe that drive strong outflows, consisting of hot (T> 5× {10}5 {{K}}) winds and warm (5050 {{K}} 1 {kpc} from the midplane has mass and energy fluxes nearly constant with d. The hot flow escapes our local Cartesian box barely affected by gravity, and is expected to accelerate up to terminal velocity of {v}{wind}∼ 350{--}500 {km} {{{s}}}-1. The mean mass and energy loading factors of the hot wind are 0.1 and 0.02, respectively. For warm gas, the mean outward mass flux through d=1 {kpc} is comparable to the mean star formation rate, but only a small fraction of this gas is at velocity > 50 {km} {{{s}}}-1. Thus, the warm outflows eventually fall back as inflows. The warm fountain flows are created by expanding hot superbubbles at d< 1 {kpc}; at larger d neither ram pressure acceleration nor cooling transfers significant momentum or energy flux from the hot wind to the warm outflow. The velocity distribution at launching near d∼ 1 {kpc} is a better representation of warm outflows than a single mass loading factor, potentially enabling development of subgrid models for warm galactic winds in arbitrary large-scale galactic potentials.

  8. Solar-assisted gas-energy water-heating feasibility for apartments

    Science.gov (United States)

    Davis, E. S.

    1975-01-01

    Studies of residential energy use, solar-energy technology for buildings, and the requirements for implementing technology in the housing industry led to a project to develop a solar water heater for apartments. A design study for a specific apartment was used to establish a solar water-heater cost model which is based on plumbing contractor bids and manufacturer estimates. The cost model was used to size the system to minimize the annualized cost of hot water. The annualized cost of solar-assisted gas-energy water heating is found to be less expensive than electric water heating but more expensive than gas water heating. The feasibility of a natural gas utility supplying the auxiliary fuel is evaluated. It is estimated that gas-utilizing companies will find it profitable to offer solar water heating as part of a total energy service option or on a lease basis when the price of new base-load supplies of natural gas reaches $2.50-$3.00 per million Btu.

  9. A novel solar-assisted heat pump driven by photovoltaic/thermal collectors: Dynamic simulation and thermoeconomic optimization

    International Nuclear Information System (INIS)

    Calise, Francesco; Dentice d'Accadia, Massimo; Figaj, Rafal Damian; Vanoli, Laura

    2016-01-01

    This paper presents a dynamic simulation model and a thermo-economic analysis of a novel polygeneration system based on a solar-assisted heat pump and an adsorption chiller, both driven by PVT (photovoltaic/thermal) collectors. The aim of this work is to design and dynamically simulate a novel ultra-high efficient solar heating and cooling system. The overall plant layout is designed to supply electricity, space heating and cooling and domestic hot water for a small residential building. The system combines solar cooling, solar-assisted heat pump and photovoltaic/thermal collector technologies in a novel solar polygeneration system. In fact, the polygeneration system is based on a PVT solar field, coupled with a water-to-water electric heat pump or to an adsorption chiller. PVT collectors simultaneously produce electricity and thermal energy. During the winter, hot water produced by PVT collectors primarily supplies the evaporator of the heat pump, whereas in summer, solar energy supplies an adsorption chiller providing the required space cooling. All year long, solar thermal energy in excess is converted into DHW (domestic hot water). The system model was developed in TRNSYS environment. 1-year dynamic simulations are performed for different case studies in various weather conditions. The results are analysed on different time bases presenting energetic, environmental and economic performance data. Finally, a sensitivity analysis and a thermoeconomic optimization were performed, in order to determine the set of system design/control parameters that minimize the simple pay-back period. The results showed a total energy efficiency of the PVT of 49%, a heat pump yearly coefficient of performance for heating mode above 4 and a coefficient of performance of the adsorption chiller of 0.55. Finally, it is also concluded that system performance is highly sensitive to the PVT field area. The system is profitable when a capital investment subsidy of 50% is considered

  10. High-Fidelity Solar Power Income Modeling for Solar-Electric UAVs: Development and Flight Test Based Verification

    OpenAIRE

    Oettershagen, Philipp

    2017-01-01

    Solar power models are a crucial element of solar-powered UAV design and performance analysis. During the conceptual design phase, their accuracy directly relates to the accuracy of the predicted performance metrics and thus the final design characteristics of the solar-powered UAV. Likewise, during the operations phase of a solar-powered UAV accurate solar power income models are required to predict and assess the solar power system performance. However, the existing literature on solar-powe...

  11. Entrance Effects in Solar Hot Water Stores

    DEFF Research Database (Denmark)

    Shah, Louise Jivan; Furbo, Simon

    2003-01-01

    A theoretical and experimental analysis of water jets entering a solar storage tank is performed. CFD calculations of three inlet designs with different inlet flow rates were carried out to illustrate the varying behaviour of the thermal conditions in a solar store. The results showed the impact ...... in an analysis using the first and second law of thermodynamics. The results showed how the entropy changes and the exergy changes in the storage during the draw-offs influenced by the Richardson number, the volume draw-off and the initial tank conditions....

  12. Hot Deformation Behavior and a Two-Stage Constitutive Model of 20Mn5 Solid Steel Ingot during Hot Compression

    Directory of Open Access Journals (Sweden)

    Min Liu

    2018-03-01

    Full Text Available 20Mn5 steel is widely used in the manufacture of heavy hydro-generator shaft forging due to its strength, toughness, and wear resistance. However, the hot deformation and recrystallization behaviors of 20Mn5 steel compressed under a high temperature were not studied. For this article, hot compression experiments under temperatures of 850–1200 °C and strain rates of 0.01 s−1–1 s−1 were conducted using a Gleeble-1500D thermo-mechanical simulator. Flow stress-strain curves and microstructure after hot compression were obtained. Effects of temperature and strain rate on microstructure are analyzed. Based on the classical stress-dislocation relationship and the kinetics of dynamic recrystallization, a two-stage constitutive model is developed to predict the flow stress of 20Mn5 steel. Comparisons between experimental flow stress and predicted flow stress show that the predicted flow stress values are in good agreement with the experimental flow stress values, which indicates that the proposed constitutive model is reliable and can be used for numerical simulation of hot forging of 20Mn5 solid steel ingot.

  13. Study on reduction of consumption and peak demand of electric power used in residential houses with solar heating and PV systems; Solar house no fuka heijunka to energy sakugen koka ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Udagawa, M.; Endo, T. [Kogakuin University, Tokyo (Japan)

    1994-12-08

    A model house was simulated to reduce the consumption and peak demand for the photovoltaic power generation system, and solar heat air heating and hot water supply system in the solar house. As a type of construction, both wooden construction and reinforced concrete (RC) construction were selected with a total floor area of 125m{sup 2}. All the rooms were equipped with an air conditioner by heat pump from the air thermal source. A solar heat floor heater was simultaneously installed on the first floor. The hot water supply load was 4.8MWh per year. A commercial grid-connected on-site system was applied to the photovoltaic power generation with a 20m{sup 2} wide monocrystalline Si solar cell panel. As for the fluctuation in power load, the peak at the time of rising is more reduced in the RC house than in the wooden house, because the former is smaller in temperature fluctuation than the latter during the intermittence of air conditioning (as per the specified operational schedule). Therefore, the power is more leveled off in the former than in the latter. Between both, difference was hardly made in energy consumption per year. The ratio of dependency was 47% upon the photovoltaic power generation system, while it was 50% and 77%, under the air heating power load and hot water supply power load, respectively, upon the solar heat air heating and hot water supply system, so that both systems were considerably effective in saving the energy. 5 refs., 7 figs., 1 tab.

  14. Improvement of sweating model in 2-Node Model and its application to thermal safety for hot environments

    Energy Technology Data Exchange (ETDEWEB)

    Ooka, Ryozo [Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba Meguro-ku, Tokyo 153 8505 (Japan); Minami, Yuriko [Tokyo Electric Power Company, Tokyo (Japan); Sakoi, Tomonori [International Young Researchers Empowerment Center, Shinshu University, Nagano (Japan); Tsuzuki, Kazuyo [National Institute of Advanced Industrial Science and Technology, Tsukuba (Japan); Rijal, H.B. [Integrated Research System for Sustainability Science, The University of Tokyo, Tokyo (Japan)

    2010-07-15

    Recently, due to global warming and the heat-island effect, more and more people are exposed to the dangers of heat disorders. A hot thermal environment can be evaluated using various indices, such as new Standard Effective Temperature (SET{sup *}) using the 2-Node Model (2 NM), Wet Bulb Globe Temperature (WBGT), Predicted Heat Strain (PHS) model, and so on. The authors aim to develop a safety evaluation approach for hot environments. Subject experiments are performed in a laboratory to comprehend the physiological response of the human body. The results are compared with the computed values from the 2 NM and PHS models, and improved the sweating model in 2 NM in order to take into account the relationship with metabolic rate. A demonstration is provided of using the new sweating model for evaluating thermal safety in a hot environment. (author)

  15. H{sub 2}O ABUNDANCES IN THE ATMOSPHERES OF THREE HOT JUPITERS

    Energy Technology Data Exchange (ETDEWEB)

    Madhusudhan, Nikku; Hedges, Christina [Institute of Astronomy, University of Cambridge, Cambridge CB3 0HA (United Kingdom); Crouzet, Nicolas; McCullough, Peter R. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Deming, Drake, E-mail: nmadhu@ast.cam.ac.uk [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States)

    2014-08-10

    The core accretion theory for giant planet formation predicts enrichment of elemental abundances in planetary envelopes caused by runaway accretion of planetesimals, which is consistent with measured super-solar abundances of C, N, P, S, Xe, and Ar in Jupiter's atmosphere. However, the abundance of O, which is expected to be the most dominant constituent of planetesimals, is unknown for solar system giant planets, owing to the condensation of water in their ultra-cold atmospheres, thereby posing a key unknown in solar system formation. On the other hand, hundreds of extrasolar ''hot Jupiters'' are known with very high temperatures (≥1000 K), making them excellent targets to measure H{sub 2}O abundances and, hence, oxygen in their atmospheres. We constrain the atmospheric H{sub 2}O abundances in three hot Jupiters (HD 189733b, HD 209458b, and WASP-12b), spanning a wide temperature range (1200-2500 K), using their near-infrared transmission spectra obtained using the Wide Field Camera 3 instrument on board the Hubble Space Telescope. We report conclusive measurements of H{sub 2}O in HD 189733b and HD 209458b, while that in WASP-12b is not well constrained by present data. The data allow nearly solar as well as significantly sub-solar abundances in HD 189733b and WASP-12b. However, for HD 209458b, we report the most precise H{sub 2}O measurement in an exoplanet to date that suggests a ∼20-135 × sub-solar H{sub 2}O abundance. We discuss the implications of our results on the formation conditions of hot Jupiters and on the likelihood of clouds in their atmospheres. Our results highlight the critical importance of high-precision spectra of hot Jupiters for deriving their H{sub 2}O abundances.

  16. DEVELOPMENT OF A SMART SOLAR TANK

    DEFF Research Database (Denmark)

    Furbo, Simon; Andersen, Elsa

    1999-01-01

    Theoretical and experimental investigations of small SDHW systems based on so-called smart solar tanks are presented. A smart solar tank is a hot water tank in which the domestic water can both be heated by solar collectors and by an auxiliary energy supply system. The auxiliary energy supply sys...

  17. Secular chaos and its application to Mercury, hot Jupiters, and the organization of planetary systems.

    Science.gov (United States)

    Lithwick, Yoram; Wu, Yanqin

    2014-09-02

    In the inner solar system, the planets' orbits evolve chaotically, driven primarily by secular chaos. Mercury has a particularly chaotic orbit and is in danger of being lost within a few billion years. Just as secular chaos is reorganizing the solar system today, so it has likely helped organize it in the past. We suggest that extrasolar planetary systems are also organized to a large extent by secular chaos. A hot Jupiter could be the end state of a secularly chaotic planetary system reminiscent of the solar system. However, in the case of the hot Jupiter, the innermost planet was Jupiter (rather than Mercury) sized, and its chaotic evolution was terminated when it was tidally captured by its star. In this contribution, we review our recent work elucidating the physics of secular chaos and applying it to Mercury and to hot Jupiters. We also present results comparing the inclinations of hot Jupiters thus produced with observations.

  18. Secular chaos and its application to Mercury, hot Jupiters, and the organization of planetary systems

    Science.gov (United States)

    Lithwick, Yoram; Wu, Yanqin

    2014-01-01

    In the inner solar system, the planets’ orbits evolve chaotically, driven primarily by secular chaos. Mercury has a particularly chaotic orbit and is in danger of being lost within a few billion years. Just as secular chaos is reorganizing the solar system today, so it has likely helped organize it in the past. We suggest that extrasolar planetary systems are also organized to a large extent by secular chaos. A hot Jupiter could be the end state of a secularly chaotic planetary system reminiscent of the solar system. However, in the case of the hot Jupiter, the innermost planet was Jupiter (rather than Mercury) sized, and its chaotic evolution was terminated when it was tidally captured by its star. In this contribution, we review our recent work elucidating the physics of secular chaos and applying it to Mercury and to hot Jupiters. We also present results comparing the inclinations of hot Jupiters thus produced with observations. PMID:24367108

  19. Non-LTE line-blanketed model atmospheres of hot stars. 2: Hot, metal-rich white dwarfs

    Science.gov (United States)

    Lanz, T.; Hubeny, I.

    1995-01-01

    We present several model atmospheres for a typical hot metal-rich DA white dwarf, T(sub eff) = 60,000 K, log g = 7.5. We consider pure hydrogen models, as well as models with various abundances of two typical 'trace' elements-carbon and iron. We calculte a number of Local Thermodynamic Equilibrium (LTE) and non-LTE models, taking into account the effect of numerous lines of these elements on the atmospheric structure. We demostrate that while the non-LTE effects are notvery significant for pure hydrogen models, except for describing correctly the central emission in H-alpha they are essential for predicting correctly the ionization balance of metals, such as carbon and iron. Previously reported discrepancies in LTE abundances determinations using C III and C IV lines are easily explained by non-LTE effects. We show that if the iron abundance is larger than 10(exp -5), the iron line opacity has to be considered not only for the spectrum synthesis, but also in the model construction itself. For such metal abundances, non-LTE metal line-blanketed models are needed for detailed abundance studies of hot, metal-rich white dwarfs. We also discuss the predicted Extreme Ultraviolet (EUV) spectrum and show that it is very sensitive to metal abundances, as well as to non-LTE effects.

  20. Investigation of the simulation for the solar DHW system by TRNSYS; TRNSYS ni yoru kaihogata tank wo mochiita solar kyuto system no simulation chosa

    Energy Technology Data Exchange (ETDEWEB)

    Oishi, M; Noguchi, T [Japan Quality Assurance Organization, Tokyo (Japan); Okumiya, M [Nagoya University, Nagoya (Japan)

    1997-11-25

    With an objective of establishing a method for evaluating performance of a photovoltaic hot water supply system, a discussion was given on utilization of the simulation program, TRANSYS. The discussion was addressed on a photovoltaic hot water supply system of forcible circulation type using commercially available open-type heat storage tanks. An experiment was performed as an indoor test using an artificial solar light source. The TRANSYS makes available a type 04 which handles each node as a complete mixture by fixing and dividing the heat storage tank, and a type 38 which expresses heat transfer between temperature layers by means of piston flow as a heat transfer coefficient. Both types were subjected to calculation. The result of the discussion may be summarized as follows: both types provided values close to the experimental values of quantity of heat derived by utilizing solar heat; however, with the type 04, heat transfer cannot be modeled if the system is left still with temperature difference in the heat storage tank being large; and with the type 38, modeling is possible when the system is left still with temperature difference in the heat storage tank being large, but temperature gradient is difficult to be modeled during heat collection and when hot water is supplied. 1 ref., 7 figs., 5 tabs.

  1. FIRST NEW SOLAR MODELS WITH OPAS OPACITY TABLES

    Energy Technology Data Exchange (ETDEWEB)

    Le Pennec, M.; Turck-Chièze, S.; Salmon, S. [CEA/IRFU/Service d’Astrophysique, CE Saclay, F-91191 Gif sur Yvette (France); Blancard, C.; Cossé, P.; Faussurier, G.; Mondet, G. [CEA, DAM, DIF, F-91297 Arpajon (France)

    2015-11-10

    Stellar seismology appears more and more as a powerful tool for a better determination of the fundamental properties of solar-type stars. However, the particular case of the Sun is still challenging. For about a decade now, the helioseismic sound-speed determination has continued to disagree with the standard solar model (SSM) prediction, questioning the reliability of this model. One of the sources of uncertainty could be in the treatment of the transport of radiation from the solar core to the surface. In this Letter, we use the new OPAS opacity tables, recently available for solar modeling, to address this issue. We discuss first the peculiarities of these tables, then we quantify their impact on the solar sound-speed and density profiles using the reduced OPAS tables taken on the grids of the OPAL ones. We use the two evolution codes, Modules for Experiments in Stellar Astrophysics and Code Liégeois d’Evolution Stellaire, that led to similar conclusions in the solar radiative zone. In comparison to commonly used OPAL opacity tables, the new solar models are computed for the most recent photospheric composition with OPAS tables and present improvements to the location of the base of the convective zone and to the description of the solar radiative zone in comparison to the helioseismic observations, even if the differences in the Rosseland mean opacity do not exceed 6%. We finally carry out a comparison to a solar model computed with the OP opacity tables.

  2. An economic and performance design study of solar preheaters for domestic hot water heaters in North Carolina

    Science.gov (United States)

    Jones, C. B.; Smetana, F. O.

    1977-01-01

    The performance and estimated material costs for several solar preheaters for domestic hot water heaters using isolation levels present in North Carolina are presented. The effects of monthly variations in isolation and the direction of incident radiation are included. Demand is assumed at 13 gallons (49.2 liters) per day per person. The study shows that a closed circulation system with 82 gallons (310 liters) of preheated storage and 53.4 cu ft (4.94 cu m) of collector surface with single cover can be expected to cost about $800 and to repay it capital cost and interest (at 8%) in 5.2 years, assuming present electric rates increase at 5% per year.

  3. Solar campaign 'Solar - na klar.' (solar - of course). Final report; Solarkampagne 'Solar - na klar.'. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Gege, M.; Kleinsteuber, A.; Krabbe, P.; Kroeger, P.; Maschke, K.; Niedert, S.; Schindelmann, F.; Thunert, A.; Weinberg, H.

    2002-03-18

    The German market for technically matured solar-thermal systems for generating hot water is growing by 20 per cent per year, with some deviations due to incentive policies. This growth can be and is planned to be increased systematically, with following goals: A practical contribution to the Federal Government's efforts to achieve the goals regarding the protection of climate; creating future-oriented jobs; supporting ecologically sustainable ways of life and models of consumption by convincing the consumers and other target groups of the fact that it makes sense already today to start utilizing solar energy and to invest also on private basis. These targets are expected to be set up with the help of a three-year mass campaign (1999 until 2001), i.e. the campaign called ''Solar - na klar.'' (solar - of course). [German] Der deutsche Markt fuer die technisch ausgereiften solarthermischen Anlagen zur Warmwassererzeugung waechst mit ca. 20% p.a., mit foerderpolitisch bedingten Schwankungen. Dieses Wachstum kann und soll systematisch gesteigert werden, mit folgenden Zielsetzungen: Praktischer Beitrag zur Erreichung der Klimaschutzziele der Bundesregierung; Schaffung zukunftsorientierter Arbeitsplaetze; Befoerderung oekologisch nachhaltiger Lebensstile und Konsummuster durch die Ueberzeugung der Verbraucher und weiterer Zielgruppen, dass es heute bereits sinnvoll ist, in die Nutzung der Solarenergie konkret einzusteigen und auch privat zu investieren. Diese Ziele sollen mithilfe einer auf drei Jahre angelegten Breitenkampagne (1999 bis 2001), d.h. der Kampagne 'Solar - na klar.' erfolgen. (orig.)

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

    International Nuclear Information System (INIS)

    Saleh, A.; Mosa, M.

    2014-01-01

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

  5. Solar Heating Systems with Evacuated Tubular Solar Collector

    DEFF Research Database (Denmark)

    Qin, Lin; Furbo, Simon

    1998-01-01

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

  6. Stellar atmosphere modeling of extremely hot, compact stars

    Science.gov (United States)

    Rauch, Thomas; Ringat, Ellen; Werner, Klaus

    Present X-ray missions like Chandra and XMM-Newton provide excellent spectra of extremely hot white dwarfs, e.g. burst spectra of novae. Their analysis requires adequate NLTE model atmospheres. The Tuebingen Non-LTE Model-Atmosphere Package (TMAP) can calculate such model at-mospheres and spectral energy distributions at a high level of sophistication. We present a new grid of models that is calculated in the parameter range of novae and supersoft X-ray sources and show examples of their application.

  7. Solar energy system performance evaluation report for IBM System 4 at Clinton, Mississippi

    Science.gov (United States)

    1980-07-01

    The IBM System 4 Solar Energy System is described and evaluated. The system was designed to provide 35 percent of the space heating and 63 percent of the domestic hot water preheating for a single family residence located within the United States. The system consists of 259 square feet of flat plate air collectors, a rock thermal storage containing 5 1/2 ton of rock, heat exchangers, blowers, a 52 gallon preheat tank, controls, and associated plumbing. In general, the performance of the system did not meet design expectations, since the overall design solar fraction was 48 percent and the measured value was 32 percent. Although the measured space heating solar fraction at 32 percent did agree favorably with the design space heating solar fraction at 35 percent, the hot water measured solar fraction at 33 percent did not agree favorably with the design hot water solar fraction of 63 percent. In particular collector array air leakage, dust covered collectors, abnormal hot water demand, and the preheat tank by pass valve problem are main reasons for the lower performance.

  8. Theoretcial studies of solar-pumped lasers

    Science.gov (United States)

    Harries, W. L.; Fong, Z. S.

    1984-01-01

    A method of pumping a COhZ laser by a hot cavity was demonstrated. The cavity, heated by solar radiation, should increase the efficiency of solar pumped lasers used for energy conversion. Kinetic modeling is used to examine the behavior of such a COhZ laser. The kinetic equations are solved numerically vs. time and, in addition, steady state solutions are obtained analytically. The effect of gas heating filling the lower laser level is included. The output power and laser efficiency are obtained as functions of black body temperature and gas ratios (COhZ-He-Ar) and pressures. The values are compared with experimental results.

  9. AISI/DOE Advanced Process Control Program Vol. 3 of 6: MICROSTRUCTURAL ENGINEERING IN HOT-STRIP MILLS Part 2 of 2: Constitutive Behavior Modeling of Steels Under Hot-Rolling Conditions; FINAL

    International Nuclear Information System (INIS)

    Yi-Wen Cheng; Patrick Purtscher

    1999-01-01

    This report describes the development of models for predicting (1) constitutive behaviors and (2) mechanical properties of hot-rolled steels as functions of chemical composition, microstructural features, and processing variables. The study includes the following eight steels: A36, DQSK, HSLA-V, HSLA-Nb, HSLA-50/Ti-Nb, and two interstitial-free (IF) grades. These developed models have been integrated into the Hot-Strip Mill Model (HSMM), which simulates the hot strip rolling mills and predicts the mechanical properties of hot-rolled products. The HSMM model has been developed by the University of British Columbia-Canada as a part of project on the microstructural engineering in hot-strip mills

  10. The technical use of solar energy

    International Nuclear Information System (INIS)

    Hahne, E.

    1993-01-01

    For all considerations on energy, information on energy-quantity and energy-value is necessary. Such information is presented for Germany as an example for an industrialized country. The application of solar heat for an Institute building is presented for a pilot project at the University Stuttgart. With unglazed solar collectors, a flooded pebble-bed store and a heat pump, about 60% of the Institute's heat demand can be supplied by solar energy. With the experience gained from this project, large district heating systems are designed for two different locations in Germany under differing conditions. For solar assisted house heating and domestic hot water, heat costs are obtained which are about twice the present heat cost in Germany. If solar energy assists domestic hot water production and house heating, costs can be achieved which are below present conventional heat cost. In addition, it will also reduce air pollution. (author). 9 figs., 6 tabs

  11. Solar heat-pipe wick modeling

    Energy Technology Data Exchange (ETDEWEB)

    Andraka, C.E.

    1999-07-01

    Stirling-cycle engines have been identified as a promising technology for the conversion of concentrated solar energy into usable electrical power. In previous experimental work, the author has demonstrated that a heat pipe receiver can significantly improve system performance over a directly-illuminated heater head. The design and operating conditions of a heat pipe receiver differ significantly from typical laboratory heat pipes. New wick structures have been developed to exploit the characteristics of the solar generation system. Typically, these wick structures allow vapor generation within the wick. Conventional heat pipe models do not handle this enhancement, yet it can more than double the performance of the wick. In this study, the author developed a steady-state model of a boiling-enhanced wick for a solar heat pipe receiver. The model is used for design-point calculations and is written in FORTRAN90. Some limited comparisons have been made with actual test data.

  12. FINANCIAL ANALYSIS OF SOLAR ENERGY APPLICATIONS WITH ENDOGENOUS SYSTEM SIZING

    OpenAIRE

    Gunter, Lewell F.; Smathers, Webb M., Jr.

    1984-01-01

    This paper is concerned with analysis of economic feasibility of solar energy systems. Methodology for estimating energy output from different sized systems is briefly presented, and this is used to determine technical coefficients for a mixed integer model which optimizes the size of the solar heating unit for a particular use. An empirical example of hot water heating on a Georgia dairy is presented. Cost curves are provided for the dairy example to illustrate the effect of sizing on the ec...

  13. Toward Improved Modeling of Spectral Solar Irradiance for Solar Energy Applications: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Yu [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sengupta, Manajit [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-10-19

    This study introduces the National Renewable Energy Laboratory's (NREL's) recent efforts to extend the capability of the Fast All-sky Radiation Model for Solar applications (FARMS) by computing spectral solar irradiances over both horizontal and inclined surfaces. A new model is developed by computing the optical thickness of the atmosphere using a spectral irradiance model for clear-sky conditions, SMARTS2. A comprehensive lookup table (LUT) of cloud bidirectional transmittance distribution functions (BTDFs) is precomputed for 2002 wavelength bands using an atmospheric radiative transfer model, libRadtran. The solar radiation transmitted through the atmosphere is given by considering all possible paths of photon transmission and the relevent scattering and absorption attenuation. Our results indicate that this new model has an accuracy that is similar to that of state-of-the-art radiative transfer models, but it is significantly more efficient.

  14. Stochastic modelling of the thermal characteristics of a hot-water storage tank on the basis of Markov chains; Zur stochastischen Modellierung des thermischen Verhaltens eines Warmwasserspeichers mittels Markov`scher Ketten

    Energy Technology Data Exchange (ETDEWEB)

    Werner, U.J. [Bauhaus-Universitaet Weimar (Germany). Fakultaet Bauingenieurwesen

    1998-09-01

    In an earlier contribution, a stochastic model was presented for a hot water storage tank supplied by a solar collector. The model was characterized in that the storage tank was assumed to be an ideal stratified storage tank, and its volume was subdivided into discrete identical storage compartments, so-called states, on the basis of the energy withdrawn from the tank. This simple model is now extended by assuming a stochastic variable for energy withdrawal and by taking account of energy loss at the surface of the hot water storage tank and inside it. [Deutsch] In einem frueheren Beitrag war fuer einen thermischen Speicher, der von einem Sonnenkollektor gespeist wird, ein stochastisches mathematisches Modell derart aufgestellt worden, dass ein als idealer Schichtenspeicher konzipierter Warmwasserspeicher bezueglich seines Volumens in diskrete, an der Energieentnahme orientierte, gleiche Speichereinheiten, sogenannte Zustaende, unterteilt wurde. Das einfache Modell wird nunmehr erweitert, indem die Entnahme als eine stochastische Groesse angenommen wird und die Energieverluste am und im Warmwasserspeicher Beruecksichtigung finden. (orig.)

  15. New Temperature-based Models for Predicting Global Solar Radiation

    International Nuclear Information System (INIS)

    Hassan, Gasser E.; Youssef, M. Elsayed; Mohamed, Zahraa E.; Ali, Mohamed A.; Hanafy, Ahmed A.

    2016-01-01

    Highlights: • New temperature-based models for estimating solar radiation are investigated. • The models are validated against 20-years measured data of global solar radiation. • The new temperature-based model shows the best performance for coastal sites. • The new temperature-based model is more accurate than the sunshine-based models. • The new model is highly applicable with weather temperature forecast techniques. - Abstract: This study presents new ambient-temperature-based models for estimating global solar radiation as alternatives to the widely used sunshine-based models owing to the unavailability of sunshine data at all locations around the world. Seventeen new temperature-based models are established, validated and compared with other three models proposed in the literature (the Annandale, Allen and Goodin models) to estimate the monthly average daily global solar radiation on a horizontal surface. These models are developed using a 20-year measured dataset of global solar radiation for the case study location (Lat. 30°51′N and long. 29°34′E), and then, the general formulae of the newly suggested models are examined for ten different locations around Egypt. Moreover, the local formulae for the models are established and validated for two coastal locations where the general formulae give inaccurate predictions. Mostly common statistical errors are utilized to evaluate the performance of these models and identify the most accurate model. The obtained results show that the local formula for the most accurate new model provides good predictions for global solar radiation at different locations, especially at coastal sites. Moreover, the local and general formulas of the most accurate temperature-based model also perform better than the two most accurate sunshine-based models from the literature. The quick and accurate estimations of the global solar radiation using this approach can be employed in the design and evaluation of performance for

  16. Research and development of utilization technology of solar thermal system for industrial and other use. Research and development of solar system (research for solar/energy-conservation technology retrofitted to existing buildings); Sangyoyo nado solar system jitsuyoka gijutsu kaihatsu. Solar system no chosa kenkyu (solar toshi muke gijutsu ni kansuru chosa)

    Energy Technology Data Exchange (ETDEWEB)

    Takita, M [New Energy and Industrial Technology Development Organization, Tokyo (Japan)

    1994-12-01

    Described herein are the results of the FY1994 research program for solar/energy-conversion technologies retrofitted to existing buildings. The estimated effects and economic viability of retrofitting technologies show that they bring very high energy-saving effects when applied to heating and hot water supply, which consume a large portion of energy, but relatively low energy-saving effects when applied to cooling, solar walls, glazed balconies and transparent insulators. The study on applicability of these technologies in Japan indicates that the technologies which can recover cost within an average life time are those applied to windows, solar collector systems for hot water supply and heating, and transparent insulators. Although these technologies are low in applicability to cooling viewed from the angle of cost recovery, retrofitted radiation type cooling systems improve not only cooling and energy-saving effects but also comfortableness.

  17. Solar assisted conditioning of residences with floor heating and ceiling cooling: review and simulation results

    OpenAIRE

    Egrican, Nilufer; Korkmaz, Adnan

    2015-01-01

    Solar or solar assisted heating and cooling systems are becoming widespread to reduce CO2 emissions. Efficient radiant space heating and cooling systems can be used to decrease the energy bills and improve occupant thermal comfort in buildings. This study uses the TRNSYS program, for the modeling and simulation of solar assisted radiant heating and cooling of a building with the domestic hot water supply, to examine the effects of various parameters on energy consumption. Calculations are per...

  18. Detection of nanoflare-heated plasma in the solar corona by the FOXSI-2 sounding rocket

    Science.gov (United States)

    Ishikawa, Shin-nosuke; Glesener, Lindsay; Krucker, Säm; Christe, Steven; Buitrago-Casas, Juan Camilo; Narukage, Noriyuki; Vievering, Juliana

    2017-11-01

    The processes that heat the solar and stellar coronae to several million kelvins, compared with the much cooler photosphere (5,800 K for the Sun), are still not well known1. One proposed mechanism is heating via a large number of small, unresolved, impulsive heating events called nanoflares2. Each event would heat and cool quickly, and the average effect would be a broad range of temperatures including a small amount of extremely hot plasma. However, detecting these faint, hot traces in the presence of brighter, cooler emission is observationally challenging. Here we present hard X-ray data from the second flight of the Focusing Optics X-ray Solar Imager (FOXSI-2), which detected emission above 7 keV from an active region of the Sun with no obvious individual X-ray flare emission. Through differential emission measure computations, we ascribe this emission to plasma heated above 10 MK, providing evidence for the existence of solar nanoflares. The quantitative evaluation of the hot plasma strongly constrains the coronal heating models.

  19. Solar energy market penetration models - Science or number mysticism

    Science.gov (United States)

    Warren, E. H., Jr.

    1980-01-01

    The forecast market potential of a solar technology is an important factor determining its R&D funding. Since solar energy market penetration models are the method used to forecast market potential, they have a pivotal role in a solar technology's development. This paper critiques the applicability of the most common solar energy market penetration models. It is argued that the assumptions underlying the foundations of rigorously developed models, or the absence of a reasonable foundation for the remaining models, restrict their applicability.

  20. Empirical investigation on modeling solar radiation series with ARMA–GARCH models

    International Nuclear Information System (INIS)

    Sun, Huaiwei; Yan, Dong; Zhao, Na; Zhou, Jianzhong

    2015-01-01

    Highlights: • Apply 6 ARMA–GARCH(-M) models to model and forecast solar radiation. • The ARMA–GARCH(-M) models produce more accurate radiation forecasting than conventional methods. • Show that ARMA–GARCH-M models are more effective for forecasting solar radiation mean and volatility. • The ARMA–EGARCH-M is robust and the ARMA–sGARCH-M is very competitive. - Abstract: Simulation of radiation is one of the most important issues in solar utilization. Time series models are useful tools in the estimation and forecasting of solar radiation series and their changes. In this paper, the effectiveness of autoregressive moving average (ARMA) models with various generalized autoregressive conditional heteroskedasticity (GARCH) processes, namely ARMA–GARCH models are evaluated for their effectiveness in radiation series. Six different GARCH approaches, which contain three different ARMA–GARCH models and corresponded GARCH in mean (ARMA–GARCH-M) models, are applied in radiation data sets from two representative climate stations in China. Multiple evaluation metrics of modeling sufficiency are used for evaluating the performances of models. The results show that the ARMA–GARCH(-M) models are effective in radiation series estimation. Both in fitting and prediction of radiation series, the ARMA–GARCH(-M) models show better modeling sufficiency than traditional models, while ARMA–EGARCH-M models are robustness in two sites and the ARMA–sGARCH-M models appear very competitive. Comparisons of statistical diagnostics and model performance clearly show that the ARMA–GARCH-M models make the mean radiation equations become more sufficient. It is recommended the ARMA–GARCH(-M) models to be the preferred method to use in the modeling of solar radiation series

  1. Solar water heater design package

    Science.gov (United States)

    1981-01-01

    Package describes commercial domestic-hot-water heater with roof or rack mounted solar collectors. System is adjustable to pre-existing gas or electric hot-water house units. Design package includes drawings, description of automatic control logic, evaluation measurements, possible design variations, list of materials and installation tools, and trouble-shooting guide and manual.

  2. ANALYSIS OF MEASURED AND MODELED SOLAR RADIATION AT THE TARS SOLAR HEATING PLANT IN DENMARK

    DEFF Research Database (Denmark)

    Tian, Zhiyong; Perers, Bengt; Furbo, Simon

    2017-01-01

    , such as solar radiation, inlet and outlet temperature for the solar collector field, flow rate and pressure, ambient temperature, Wind speed and wind direction were measured. Global horizontal radiation, direct normal irradiation (DNI) and total radiation on the tilted collector plane of the flat plate...... collector field have been measured in Tars solar heating plant. To determine the accuracy of modeled and measured solar radiation in Tars solar heating plant, monthly comparisons of measured and calculated radiation using 6 empirical models have been carried out. Comparisons of measured and modeled total......A novel combined solar heating plant with tracking parabolic trough collectors (PTC) and flat plate collectors (FPC) has been constructed and put into operation in Tars, 30 km north of Aalborg, Denmark in August 2015. To assess the operation performance of the plant, detailed parameters...

  3. Solar heating for a restaurant--North Little Rock, Arkansas

    Science.gov (United States)

    1981-01-01

    Hot water consumption of large building affects solar-energy system design. Continual demand for hot water at restaurant makes storage less important than at other sites. Storage capacity of system installed in December 1979 equals estimated daily hot-water requirement. Report describes equipment specifications and modifications to existing building heating and hot water systems.

  4. Students To Compete in Model Solar Car Race

    Science.gov (United States)

    cars in the 1998 Junior Solar Sprint. The race will be held at the U.S. Department of Energy's (DOE Compete in Model Solar Car Race For more information contact: e:mail: Public Affairs Golden, Colo ., May 8, 1998 — Middle school students from across Colorado will design, build and race model solar

  5. Solar Pump

    Science.gov (United States)

    Pique, Charles

    1987-01-01

    Proposed pump moves liquid by action of bubbles formed by heat of sun. Tube of liquid having boiling point of 100 to 200 degrees F placed at focal axis of cylindrical reflector. Concentrated sunlight boils liquid at focus, and bubbles of vapor rise in tube, carrying liquid along with them. Pressure difference in hot tube sufficient to produce flow in large loop. Used with conventional flat solar heating panel in completely solar-powered heat-storage system.

  6. Solar models: An historical overview

    International Nuclear Information System (INIS)

    Bahcall, John N.

    2003-01-01

    I will summarize in four slides the 40 years of development of the standard solar model that is used to predict solar neutrino fluxes and then describe the current uncertainties in the predictions. I will dispel the misconception that the p-p neutrino flux is determined by the solar luminosity and present a related formula that gives, in terms of the p-p and 7 Be neutrino fluxes, the ratio of the rates of the two primary ways of terminating the p-p fusion chain. I will also attempt to explain why it took so long, about three and a half decades, to reach a consensus view that new physics is being learned from solar neutrino experiments. Finally, I close with a personal confession

  7. Heat losses through pipe connections in hot water stores

    DEFF Research Database (Denmark)

    Andersen, Elsa; Fan, Jianhua; Furbo, Simon

    2007-01-01

    The heat loss from pipe connections at the top of hot water storage tanks with and without a heat trap is investigated theoretically and compared to similar experimental investigations. Computational Fluid Dynamics (CFD) is used for the theoretical analysis. The investigations show that the heat...... loss from an ideally insulated pipe connected to the top of a hot water tank is mainly due to a natural convection flow in the pipe, that the heat loss coefficient of pipes connected to the top of a hot water tank is high, and that a heat trap can reduce the heat loss coefficient significantly. Further......, calculations show that the yearly thermal performance of solar domestic hot water systems is strongly reduced if the hot water tank has a thermal bridge located at the top of the tank....

  8. Residence time modeling of hot melt extrusion processes.

    Science.gov (United States)

    Reitz, Elena; Podhaisky, Helmut; Ely, David; Thommes, Markus

    2013-11-01

    The hot melt extrusion process is a widespread technique to mix viscous melts. The residence time of material in the process frequently determines the product properties. An experimental setup and a corresponding mathematical model were developed to evaluate residence time and residence time distribution in twin screw extrusion processes. The extrusion process was modeled as the convolution of a mass transport process described by a Gaussian probability function, and a mixing process represented by an exponential function. The residence time of the extrusion process was determined by introducing a tracer at the extruder inlet and measuring the tracer concentration at the die. These concentrations were fitted to the residence time model, and an adequate correlation was found. Different parameters were derived to characterize the extrusion process including the dead time, the apparent mixing volume, and a transport related axial mixing. A 2(3) design of experiments was performed to evaluate the effect of powder feed rate, screw speed, and melt viscosity of the material on the residence time. All three parameters affect the residence time of material in the extruder. In conclusion, a residence time model was developed to interpret experimental data and to get insights into the hot melt extrusion process. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. The 1995 total solar eclipse: an overview.

    Science.gov (United States)

    Singh, J.

    A number of experiments were conducted during the total solar eclipse of October 24, 1995. First time efforts were made to photograph the solar corona using IAF jet aircrafts and transport planes ad hot air balloons.

  10. Solar systems and heat pumps in operation in Carinthia: results 1994 - 1997

    International Nuclear Information System (INIS)

    Faninger, G.

    1998-04-01

    Solar systems and heat pumps in operation in Carinthia: results 1994 - 1997. Test results from solar systems for swimming pool heating, hot water preparation and space heating as well as heat pumps for hot water preparation, space heating and heat recovery will be reported and assessed collectively. (author)

  11. Solar-Heated and Cooled Office Building--Columbus, Ohio

    Science.gov (United States)

    1982-01-01

    Final report documents solar-energy system installed in office building to provide space heating, space cooling and domestic hot water. Collectors mounted on roof track Sun and concentrate rays on fluid-circulating tubes. Collected energy is distributed to hot-water-fired absorption chiller and space-heating and domestic-hot-water preheating systems.

  12. Thermal Performance of a Large Low Flow Solar Heating System with a Highly Thermally Stratified Tank

    DEFF Research Database (Denmark)

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

    2005-01-01

    are facing west. The collector tilt is 15° from horizontal for all collectors. Both the east-facing and the west-facing collectors have their own solar collector loop, circulation pump, external heat exchanger and control system. The external heat exchangers are used to transfer the heat from the solar......In year 2000 a 336 m² solar domestic hot water system was built in Sundparken, Elsinore, Denmark. The solar heating system is a low flow system with a 10000 l hot-water tank. Due to the orientation of the buildings half of the solar collectors are facing east, half of the solar collectors...... collector fluid to the domestic water. The domestic water is pumped from the bottom of the hot-water tank to the heat exchanger and back to the hot-water tank through stratification inlet pipes. The return flow from the DHW circulation pipe also enters the tank through stratification inlet pipes. The tank...

  13. Solar project description for Moulder Corporation single family residence, Greenwood, Indiana

    Science.gov (United States)

    1980-07-01

    The system is designed to provide solar energy for space heating and domestic hot water heating. Solar energy is used for space heating the home and preheating domestic hot water (DHW). The solar energy system has an array of flat plate collectors with a gross area of 704 square feet. The array faces 5.5 degrees west of south at an angle of 45 degrees to the horizontal. Air is the transfer medium that delivers solar energy from the collector array to storage, space heating and hot water loads. Solar energy is stored underground in 945 cubic foot bin containing 81,000 pounds of crushed rock. The bin has 8 inch concrete block walls and the insulation on the exterior is sprayed urethane. Preheated city water is stored in an 80 gallon preheat tank, which is inside the storage bin and is supplied, on demand, to a conventional 52 gallon DHW tank. When solar energy is insufficient to satisfy the space heating load, a conventional electric furnace provides the auxiliary energy for space heating.

  14. Performance evaluation of a solar adsorption chiller under different climatic conditions

    International Nuclear Information System (INIS)

    Alahmer, Ali; Wang, Xiaolin; Al-Rbaihat, Raed; Amanul Alam, K.C.; Saha, B.B.

    2016-01-01

    Highlights: • A solar adsorption cooling system was studied at different climatic conditions. • Effect of hot water temperature and flow rate on system performance was evaluated. • Solar collector area and tilting angle largely affected the system performance. • Economics of the solar adsorption cooling was analysed at real weather conditions. • Adsorption cooling could be potentially applied in cities with good solar radiation. - Abstract: Performance of an adsorption cooling system driven by solar thermal energy was studied under different climatic conditions. The effects of solar collector area, collector slope, hot water temperature and flow rate on the system performance were investigated using the real-time weather data of two cities: Perth, Australia (a representative city in the southern hemisphere) and Amman, Jordan (a representative city in the northern hemisphere). The simulation results showed that the two cities had similar solar radiation during the summer period and that the solar adsorption chiller could reliably provide cooling at a reasonably high system COP. For residential cooling with a total CPC (Compound Parabolic Collector) solar collector area of 36.22 m"2, the average system COP was 0.491 for Perth weather conditions and 0.467 for Amman weather conditions, respectively while the cooling capacity was 10.3 kW for Perth and 8.46 kW for Amman, respectively at peak times. Optimum performance occurred when the system run with the CPC collector slope of around 30°, the solar water storage tank volume of 1.4 m"3, inlet hot water temperature of 80 °C, and a hot water flow rate of 0.33 kg/s. An economic analysis was further investigated and the results showed that the solar driven adsorption cooling system could reduce the electricity consumption for Perth and Amman cities by 34% and 28%, respectively in comparison to a conventional vapour compression cooling system.

  15. Numerical modelling of CIGS/CdS solar cell

    Science.gov (United States)

    Devi, Nisha; Aziz, Anver; Datta, Shouvik

    2018-05-01

    In this work, we design and analyze the Cu(In,Ga)Se2 (CIGS) solar cell using simulation software "Solar Cell Capacitance Simulator in One Dimension (SCAPS-1D)". The conventional CIGS solar cell uses various layers, like intrinsic ZnO/Aluminium doped ZnO as transparent oxide, antireflection layer MgF2, and electron back reflection (EBR) layer at CIGS/Mo interface for good power conversion efficiency. We replace this conventional model by a simple model which is easy to fabricate and also reduces the cost of this cell because of use of lesser materials. The new designed model of CIGS solar cell is ITO/CIGS/OVC/CdS/Metal contact, where OVC is ordered vacancy compound. From this simple structure, even at very low illumination we are getting good results. We simulate this CIGS solar cell model by varying various physical parameters of CIGS like thickness, carrier density, band gap and temperature.

  16. Solar chimney integrated with passive evaporative cooler applied on glazing surfaces

    International Nuclear Information System (INIS)

    Al Touma, Albert; Ghali, Kamel; Ghaddar, Nesreen; Ismail, Nagham

    2016-01-01

    This study investigates the performance of a hybrid system applied on glazing surfaces for reducing the space cooling load and radiation asymmetry. The proposed system combines the principles of passive evaporative cooling with the natural buoyant flow in solar chimneys to entrain outdoor air and attenuate the window surface temperature. A predictive heat and mass transport model combining the evaporative cooler, glazing section, solar chimney and an office space is developed to study the system performance in harshly hot climates. The developed model was validated through experiments conducted in a twin climatic chamber for given ambient temperature, humidity, and solar radiation conditions. Good agreement was found between the measured and the predicted window temperatures and space loads at maximum discrepancy lower than 4.3%. The proposed system is applied to a typical office space to analyze its effectiveness in reducing the window temperature, the space load and radiation asymmetry, while maintaining the indoor comfort conditions. Results have shown that the system is reduced the space load by −19.8% and attenuated the radiation asymmetry significantly for office spaces having window-to-wall ratio of 40% in climate of Riyadh, KSA. The system performance diminished when applied in locations suffering from humid weather climates. - Highlights: • A passive evaporative-cooled solar chimney system is introduced to decrease window temperature. • A mathematical model is developed of the system to predict induce air flow and window surface temperature. • The model is validated with experiments in twin room climatic chamber and using artificial solar lamps. • The system reduces window maximum temperature by 5 °C in the hot dry climate of Riyadh, KSA. • It reduced the space load by 19.4% for office spaces at window-to-wall ratio of 40% in Riyadh, KSA.

  17. A solar cooling system for greenhouse food production in hot climates

    Energy Technology Data Exchange (ETDEWEB)

    Davies, P.A. [School of Engineering, University of Warwick, Coventry CV4 7AL (United Kingdom)

    2005-12-01

    This study is motivated by the difficulty of cultivating crops in very hot countries and by the tendency for some such countries to become dependent on imported food. Liquid desiccation with solar regeneration is considered as maintained at or above room temperature, and this was confirgreenhouses. Previous studies demonstrated the technical feasibility of the desiccation-evaporation process, but mainly in the context of human dwellings. In the proposed cycle, the air is dried prior to entering the evaporative cooler. This lowers the wet-bulb temperature of the air. The cooling is assisted by using the regenerator to partially shade the greenhouse. The heat of desiccation is transferred and rejected at the outlet of the greenhouse. The cycle is analysed and results given for the climate of the The Gulf, based on weather data from Abu Dhabi. Taking examples of a temperate crop (lettuce), a tropical crop (tomato) and a tropical crop resistant to high temperatures (cucumber) we estimate the extension in growing seasons relative to (i) a greenhouse with simple fan ventilation (ii) a greenhouse with conventional evaporative cooling. Compared to option (ii), the proposed system lowers summers maximum temperatures by 5{sup o}C. This will extend the optimum season for lettuce cultivation from 3 to 6 months of the year and, for tomato and cucumber, from 7 months to the whole year. (author)

  18. Dynamic modeling of human thermal comfort after the transition from an indoor to an outdoor hot environment.

    Science.gov (United States)

    Katavoutas, George; Flocas, Helena A; Matzarakis, Andreas

    2015-02-01

    Thermal comfort under non-steady-state conditions primarily deals with rapid environmental transients and significant alterations of the meteorological conditions, activity, or clothing pattern within the time scale of some minutes. In such cases, thermal history plays an important role in respect to time, and thus, a dynamic approach is appropriate. The present study aims to investigate the dynamic thermal adaptation process of a human individual, after his transition from a typical indoor climate to an outdoor hot environment. Three scenarios of thermal transients have been considered for a range of hot outdoor environmental conditions, employing the dynamic two-node IMEM model. The differences among them concern the radiation field, the activity level, and the body position. The temporal pattern of body temperatures as well as the range of skin wettedness and of water loss have been investigated and compared among the scenarios and the environmental conditions considered. The structure and the temporal course of human energy fluxes as well as the identification of the contribution of body temperatures to energy fluxes have also been studied and compared. In general, the simulation results indicate that the response of a person, coming from the same neutral indoor climate, varies depending on the scenario followed by the individual while being outdoors. The combination of radiation field (shade or not) with the kind of activity (sitting or walking) and the outdoor conditions differentiates significantly the thermal state of the human body. Therefore, 75% of the skin wettedness values do not exceed the thermal comfort limit at rest for a sitting individual under the shade. This percentage decreases dramatically, less than 25%, under direct solar radiation and exceeds 75% for a walking person under direct solar radiation.

  19. SRADLIB: A C Library for Solar Radiation Modelling

    Energy Technology Data Exchange (ETDEWEB)

    Balenzategui, J. L. [Ciemat. Madrid (Spain)

    2000-07-01

    This document shows the result of an exhaustive study about the theoretical and numerical models available in the literature about solar radiation modelling. The purpose of this study is to develop or adapt mathematical models describing the solar radiation specifically for Spain locations as well as to create computer tools able to support the labour of researchers or engineers needing solar radiation data to solve or improve the technical or energetic performance of solar systems. As results of this study and revision, a C library (SRADLIB) is presented as a key for the compilation of the mathematical models from different authors, for the comparison among the different approaches and for its application in computer programs. Different topics related to solar radiation and its modelling are first discussed, including the assumptions and conventions adopted and describing the most accepted and used current state-of-the-art models. some typical problems in the numerical calculation of radiation values are also posed with the proposed solution. The document includes next a complete reference of the developed functions, with many examples of application and calculus. (Author) 24 refs.

  20. SRADLIB: A C Library for Solar Radiation Modelling

    International Nuclear Information System (INIS)

    Balenzategui, J. L.

    1999-01-01

    This document shows the result of an exhaustive study about the theoretical and numerical models available in the literature about solar radiation modelling. The purpose of this study is to develop or adapt mathematical models describing the solar radiation specifically for Spain locations as well as to create computer tools able to support the labour of researchers or engineers needing solar radiation data to solve or improve the technical or energetic performance of solar systems. As result of this study and revision, a C library (SRADLIB) is presented as a key tool for the compilation of the mathematical models from different authors, for the comparison among the different approaches and for its application in computer programs. Different topics related to solar radiation and its modelling are first discussed, including the assumptions and conventions adopted and describing the most accepted and used current state-of-the-art models. Some typical problems in the numerical calculation of radiation values are also posed with the proposed solution. The document includes next a complete reference of the developed functions, with many examples of application and calculus. (Author) 24 refs

  1. Improving the Ni I atomic model for solar and stellar atmospheric models

    International Nuclear Information System (INIS)

    Vieytes, M. C.; Fontenla, J. M.

    2013-01-01

    Neutral nickel (Ni I) is abundant in the solar atmosphere and is one of the important elements that contribute to the emission and absorption of radiation in the spectral range between 1900 and 3900 Å. Previously, the Solar Radiation Physical Modeling (SRPM) models of the solar atmosphere only considered a few levels of this species. Here, we improve the Ni I atomic model by taking into account 61 levels and 490 spectral lines. We compute the populations of these levels in full NLTE using the SRPM code and compare the resulting emerging spectrum with observations. The present atomic model significantly improves the calculation of the solar spectral irradiance at near-UV wavelengths, which is important for Earth atmospheric studies, and particularly for ozone chemistry.

  2. Improving the Ni I atomic model for solar and stellar atmospheric models

    Energy Technology Data Exchange (ETDEWEB)

    Vieytes, M. C. [Instituto de de Astronomía y Física del Espacio, CONICET and UNTREF, Buenos Aires (Argentina); Fontenla, J. M., E-mail: mariela@iafe.uba.ar, E-mail: johnf@digidyna.com [North West Research Associates, 3380 Mitchell Lane, Boulder, CO 80301 (United States)

    2013-06-01

    Neutral nickel (Ni I) is abundant in the solar atmosphere and is one of the important elements that contribute to the emission and absorption of radiation in the spectral range between 1900 and 3900 Å. Previously, the Solar Radiation Physical Modeling (SRPM) models of the solar atmosphere only considered a few levels of this species. Here, we improve the Ni I atomic model by taking into account 61 levels and 490 spectral lines. We compute the populations of these levels in full NLTE using the SRPM code and compare the resulting emerging spectrum with observations. The present atomic model significantly improves the calculation of the solar spectral irradiance at near-UV wavelengths, which is important for Earth atmospheric studies, and particularly for ozone chemistry.

  3. Solar Heater in a West Virginia College

    Science.gov (United States)

    1982-01-01

    Solar space-heating and hot water system installed at Alderson-Broaddus College, Philippi, West Virginia, is described in 87-page document. Report contains description of building and its solar-energy system; specifications for solar-energy system, including collectors, coolant, storage tanks, circulation equipment, piping, controls, and insulation; acceptance test data; and discussion of problems with installation, their solution, and recommendations for dealing with excess solar energy.

  4. Building integrated multi PV/T/A solar system

    International Nuclear Information System (INIS)

    Ami Elazari

    2000-01-01

    Previous development in solar energy for residential applications proved that there is merit in further development and improvement of combined electricity and hot water and hot air collectors. The justification stems from the fact that waste heat is generated when PV cells are producing electricity but it decrease its efficiency dramatically, and any effective way to cool the cells can improve their efficiency and long while the heat that generated from this cooling process could be stored and used as standard solar hot water/air system. The core unit comprises of integrated PV cells mounted on a flat-plate collector for water and air, hot water storage tank hot air inlet pips to the house electric battery bank, inverter, connecting cables and controller. Double-glazing serving as solar trap to triple the amount of sun ray reaching the PV cells and other technical innovation make the system more cost effective and cost benefit for stand alone and grid connected domestic application. Two way interconnection with the electric grid like in all the roof top program may bring it to economic viability by selling excess electricity during the costly peak hours while buying low cost electricity during the night off-peak hours, and free electricity from the sun plus free hot water and hot air for domestic use as by-product. A basic domestic two-collector system may deliver up to 4 kWh of electricity and 12000 kcal of hot water and air daily. Some 22 systems are currently operating at various locations in Israel, some for 8 years with very good results. (Author)

  5. Modelling of solar energy potential in Nigeria using an artificial neural network model

    International Nuclear Information System (INIS)

    Fadare, D.A.

    2009-01-01

    In this study, an artificial neural network (ANN) based model for prediction of solar energy potential in Nigeria (lat. 4-14 o N, log. 2-15 o E) was developed. Standard multilayered, feed-forward, back-propagation neural networks with different architecture were designed using neural toolbox for MATLAB. Geographical and meteorological data of 195 cities in Nigeria for period of 10 years (1983-1993) from the NASA geo-satellite database were used for the training and testing the network. Meteorological and geographical data (latitude, longitude, altitude, month, mean sunshine duration, mean temperature, and relative humidity) were used as inputs to the network, while the solar radiation intensity was used as the output of the network. The results show that the correlation coefficients between the ANN predictions and actual mean monthly global solar radiation intensities for training and testing datasets were higher than 90%, thus suggesting a high reliability of the model for evaluation of solar radiation in locations where solar radiation data are not available. The predicted solar radiation values from the model were given in form of monthly maps. The monthly mean solar radiation potential in northern and southern regions ranged from 7.01-5.62 to 5.43-3.54 kW h/m 2 day, respectively. A graphical user interface (GUI) was developed for the application of the model. The model can be used easily for estimation of solar radiation for preliminary design of solar applications.

  6. Production of solar radiation bankable datasets from high-resolution solar irradiance derived with dynamical downscaling Numerical Weather prediction model

    Directory of Open Access Journals (Sweden)

    Yassine Charabi

    2016-11-01

    Full Text Available A bankable solar radiation database is required for the financial viability of solar energy project. Accurate estimation of solar energy resources in a country is very important for proper siting, sizing and life cycle cost analysis of solar energy systems. During the last decade an important progress has been made to develop multiple solar irradiance database (Global Horizontal Irradiance (GHI and Direct Normal Irradiance (DNI, using satellite of different resolution and sophisticated models. This paper assesses the performance of High-resolution solar irradiance derived with dynamical downscaling Numerical Weather Prediction model with, GIS topographical solar radiation model, satellite data and ground measurements, for the production of bankable solar radiation datasets. For this investigation, NWP model namely Consortium for Small-scale Modeling (COSMO is used for the dynamical downscaling of solar radiation. The obtained results increase confidence in solar radiation data base obtained from dynamical downscaled NWP model. The mean bias of dynamical downscaled NWP model is small, on the order of a few percents for GHI, and it could be ranked as a bankable datasets. Fortunately, these data are usually archived in the meteorological department and gives a good idea of the hourly, monthly, and annual incident energy. Such short time-interval data are valuable in designing and operating the solar energy facility. The advantage of the NWP model is that it can be used for solar radiation forecast since it can estimate the weather condition within the next 72–120 hours. This gives a reasonable estimation of the solar radiation that in turns can be used to forecast the electric power generation by the solar power plant.

  7. Low-cost personal cooling in hot humid offices

    DEFF Research Database (Denmark)

    Gunnarsen, Lars Bo; Santos, A.

    This report presents a low cost solution to avoid heat stress in a hot and humid environment based on a solar powered drying of supply air. The air drying facilities and a validation of the benefits through comprehensive human exposure studies are described. The study represents an example...... of applied participative research performed in a developing country. The report may be used as a background for the improvement of the indoor climate in poor, hot and humid regions without increased use of electricity....

  8. Solar water lifter

    Energy Technology Data Exchange (ETDEWEB)

    Bazarov, B A; Gonchar, V I; Maymerdangulyyev, G; Orekhova, N P; Ryabikov, S V; Strevkov, D S; Tereshin, V D; Yurin, Ye M

    1982-01-01

    A water lifter is described which contains a pump, whose piston is kinematically connected to the drive element made of material with thermal-mechanical memory of the shape in the hot state, and a solar heater.

  9. Simple characterisation of solar DHW tanks

    DEFF Research Database (Denmark)

    Andersen, Elsa; Furbo, Simon

    1998-01-01

    The aim of the project is to compare different methods used for testing small solar domestic hot water tanks. A small hot water tank is tested at three different European laboratories by means of the test methods normally used at the laboratories. The tank is marketed in Denmark.The test carried ...

  10. Bacterial growth in solar heating prepared and traditional tanks

    International Nuclear Information System (INIS)

    Bagh, L.K.

    2000-01-01

    In Denmark it has been put forward that the introduction of solar heating prepared tanks into the building regulation can cause increased nuisance with respect to bacterial growth in hot water for domestic use. The reason is that solar heating prepared tanks have a larger volume and another form of operation than traditional tanks. In this investigation the difference between bacterial growth in solar heating prepared and traditional tanks was measured by heterotrophic plate counts as a general parameter for microbiological growth. There was no significant difference between the bacterial number in the solar heating prepared tanks and in the traditional tanks, either for bacteria determined at 37 deg. C, 44 deg. C, 55 deg. C or at 65 deg. C. The hot water for domestic use from the solar heating prepared tanks and the traditional tanks had in most cases a bacterial number below 1.000 CFU/ml, and all tests had a bacterial number below 10.000 CFU/ml. The number of bacteria must be considered low seen in relation to the other measurements of bacteria in hot water for domestic use, particularly in larger block of flats. (au)

  11. Simulation Analysis of the Four Configurations of Solar Desiccant Cooling System Using Evaporative Cooling in Tropical Weather in Malaysia

    Directory of Open Access Journals (Sweden)

    M. M. S. Dezfouli

    2014-01-01

    Full Text Available A high demand for air conditioning systems exists in hot and humid regions because of the warm climate during the year. The high energy consumption of conventional air conditioning system is the reason for our investigation of the solar desiccant cooling system as an energy-efficient cooling system. Four model configurations were considered to determine the best configuration of a solar desiccant cooling system: one-stage ventilation, one-stage recirculation, two-stage ventilation, and two-stage recirculation. These models were stimulated for 8,760 hr of operation under hot and humid weather in Malaysia. Several parameters (i.e., coefficient of performance or COP, room temperature and humidity ratio, and the solar fraction of each system were evaluated by detecting the temperature and humidity ratio of the different points of each configuration by TRNSYS simulation. The latent and sensible loads of the test room were 0.875 kW and 2.625 kW, respectively. By investigating the simulation results of the four systems, the ventilation modes were found to be higher than the recirculation modes in the one- and two-stage solar desiccant cooling systems. The isothermal dehumidification COP of the two-stage ventilation was higher than that of the two-stage recirculation. Hence, the two-stage ventilation mode desiccant cooling system in a hot and humid area has higher efficiency than the other configurations.

  12. The Department of Energy`s Solar Industrial Program: 1995 review

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-04-01

    During 1995, the Department of Energy`s Solar Industrial (SI) Program worked to bring the benefits of solar energy to America`s industrial sector. Scientists and engineers within the program continued the basic research, applied engineering, and economic analyses that have been at the heart of the Program`s success since its inception in 1989. In 1995, all three of the SI Program`s primary areas of research and development--solar detoxification, advanced solar processes, and solar process heat--succeeded in increasing the contribution made by renewable and energy-efficient technologies to American industry`s sustainable energy future. The Solar Detoxification Program develops solar-based pollution control technologies for destroying hazardous environmental contaminants. The Advanced Solar Processes Program investigates industrial uses of highly concentrated solar energy. The Solar Process Heat Program conducts the investigations and analyses that help energy planners determine when solar heating technologies--like those that produce industrial-scale quantities of hot water, hot air, and steam--can be applied cost effectively. The remainder of this report highlights the research and development conducted within in each of these subprograms during 1995.

  13. NEW MODEL FOR SOLAR RADIATION ESTIMATION FROM ...

    African Journals Online (AJOL)

    NEW MODEL FOR SOLAR RADIATION ESTIMATION FROM MEASURED AIR TEMPERATURE AND ... Nigerian Journal of Technology ... Solar radiation measurement is not sufficient in Nigeria for various reasons such as maintenance and ...

  14. Solar space heating for the Visitors Center, Stephens College, Columbia, Missouri

    Science.gov (United States)

    1980-01-01

    The solar energy system located at the Visitors' Center on the Stephens College Campus, Columbia, Missouri is discussed. The system is installed in a four-story, 15,000 square foot building. The solar energy system is an integral design of the building and utilizes 176 hydronic flat plate collectors which use a 50 percent water ethylene blycol solution and water-to-water heat exchanger. Solar heated water is stored in a 5,000 gallon water storage tank located in the basement equipment room. A natural gas fired hot water boiler supplies hot water when the solar energy heat supply fails to meet the demand. The designed solar contribution is 71 percent of the heating load.

  15. THEMIS satellite observations of hot flow anomalies at Earth's bow shock

    Directory of Open Access Journals (Sweden)

    C. Chu

    2017-03-01

    Full Text Available Hot flow anomalies (HFAs at Earth's bow shock were identified in Time History of Events and Macroscale Interactions During Substorms (THEMIS satellite data from 2007 to 2009. The events were classified as young or mature and also as regular or spontaneous hot flow anomalies (SHFAs. The dataset has 17 young SHFAs, 49 mature SHFAs, 15 young HFAs, and 55 mature HFAs. They span a wide range of magnetic local times (MLTs from approximately 7 to 16.5 MLT. The largest ratio of solar wind to HFA core density occurred near dusk and at larger distances from the bow shock. In this study, HFAs and SHFAs were observed up to 6.3 RE and 6.1 RE (Earth radii, respectively, upstream from the model bow shock. HFA–SHFA occurrence decreases with distance upstream from the bow shock. HFAs of the highest event core ion temperatures were not seen at the flanks. The ratio of HFA ion temperature increase to HFA electron temperature increase is highest around 12 MLT and slightly duskward. For SHFAs, (Tihfa∕Tisw/(Tehfa∕Tesw generally increased with distance from the bow shock. Both mature and young HFAs are more prevalent when there is an approximately radial interplanetary magnetic field. HFAs occur most preferentially for solar wind speeds from 550 to 600 km s−1. The correlation coefficient between the HFA increase in thermal energy density from solar wind values and the decrease in kinetic energy density from solar wind values is 0.62. SHFAs and HFAs do not show major differences in this study.

  16. Solar Thermal Energy; Energia Solar Termica

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Martinez, M; Cuesta-Santianes, M J; Cabrera Jimenez, J A

    2008-07-01

    Approximately, 50 % of worldwide primary energy consumption is done in the form of heat in applications with a temperature lower than 250 degree centigree (low-medium temperature heat). These data clearly demonstrate the great potential of solar thermal energy to substitute conventional fossil fuels, which are becoming more expensive and are responsible for global warming. Low-medium temperature solar thermal energy is mainly used to obtain domestic hot water and provide space heating. Active solar thermal systems are those related to the use of solar thermal collectors. This study is dealing with low temperature solar thermal applications, mainly focusing on active solar thermal systems. This kind of systems has been extensively growing worldwide during the last years. At the end of 2006, the collector capacity in operation worldwide equalled 127.8 GWth. The technology is considered to be already developed and actions should be aimed at favouring a greater market penetration: diffusion, financial support, regulations establishment, etc. China and USA are the leading countries with a technology based on evacuated tube collectors and unglazed collectors, respectively. The rest of the world markets are dominated by the flat glazed collectors technology. (Author) 15 refs.

  17. On unique parameters and unified formal form of hot-wire anemometric sensor model

    International Nuclear Information System (INIS)

    LigePza, P.

    2005-01-01

    This note reviews the extensively adopted equations used as models of hot-wire anemometric sensors. An unified formal form of the mathematical model of a hot-wire anemometric sensor with otherwise defined parameters is proposed. Those parameters, static and dynamic, have simple physical interpretation and can be easily determined. They show directly the range of sensor application. They determine the metrological properties of the given sensor in the actual medium. Hence, the parameters' values might be ascribed to each sensor in the given medium and be quoted in manufacturers' catalogues, supplementing the sensor specifications. Because of their simple physical interpretation, those parameters allow the direct comparison of the fundamental metrological properties of various sensors and selection of the optimal sensor for the given research measurement application. The parameters are also useful in modeling complex hot-wire systems

  18. The problem of multicollinearity in horizontal solar radiation estimation models and a new model for Turkey

    International Nuclear Information System (INIS)

    Demirhan, Haydar

    2014-01-01

    Highlights: • Impacts of multicollinearity on solar radiation estimation models are discussed. • Accuracy of existing empirical models for Turkey is evaluated. • A new non-linear model for the estimation of average daily horizontal global solar radiation is proposed. • Estimation and prediction performance of the proposed and existing models are compared. - Abstract: Due to the considerable decrease in energy resources and increasing energy demand, solar energy is an appealing field of investment and research. There are various modelling strategies and particular models for the estimation of the amount of solar radiation reaching at a particular point over the Earth. In this article, global solar radiation estimation models are taken into account. To emphasize severity of multicollinearity problem in solar radiation estimation models, some of the models developed for Turkey are revisited. It is observed that these models have been identified as accurate under certain multicollinearity structures, and when the multicollinearity is eliminated, the accuracy of these models is controversial. Thus, a reliable model that does not suffer from multicollinearity and gives precise estimates of global solar radiation for the whole region of Turkey is necessary. A new nonlinear model for the estimation of average daily horizontal solar radiation is proposed making use of the genetic programming technique. There is no multicollinearity problem in the new model, and its estimation accuracy is better than the revisited models in terms of numerous statistical performance measures. According to the proposed model, temperature, precipitation, altitude, longitude, and monthly average daily extraterrestrial horizontal solar radiation have significant effect on the average daily global horizontal solar radiation. Relative humidity and soil temperature are not included in the model due to their high correlation with precipitation and temperature, respectively. While altitude has

  19. Multi-wavelength imaging of solar plasma. High-beta disruption model of solar flares

    International Nuclear Information System (INIS)

    Shibasaki, Kiyoto

    2007-01-01

    Solar atmosphere is filled with plasma and magnetic field. Activities in the atmosphere are due to plasma instabilities in the magnetic field. To understand the physical mechanisms of activities / instabilities, it is necessary to know the physical conditions of magnetized plasma, such as temperature, density, magnetic field, and their spatial structures and temporal developments. Multi-wavelength imaging is essential for this purpose. Imaging observations of the Sun at microwave, X-ray, EUV and optical ranges are routinely going on. Due to free exchange of original data among solar physics and related field communities, we can easily combine images covering wide range of spectrum. Even under such circumstances, we still do not understand the cause of activities in the solar atmosphere well. The current standard model of solar activities is based on magnetic reconnection: release of stored magnetic energy by reconnection is the cause of solar activities on the Sun such as solar flares. However, recent X-ray, EUV and microwave observations with high spatial and temporal resolution show that dense plasma is involved in activities from the beginning. Based on these observations, I propose a high-beta model of solar activities, which is very similar to high-beta disruptions in magnetically confined fusion experiments. (author)

  20. Electric solar wind sail mass budget model

    Directory of Open Access Journals (Sweden)

    P. Janhunen

    2013-02-01

    Full Text Available The electric solar wind sail (E-sail is a new type of propellantless propulsion system for Solar System transportation, which uses the natural solar wind to produce spacecraft propulsion. The E-sail consists of thin centrifugally stretched tethers that are kept charged by an onboard electron gun and, as such, experience Coulomb drag through the high-speed solar wind plasma stream. This paper discusses a mass breakdown and a performance model for an E-sail spacecraft that hosts a mission-specific payload of prescribed mass. In particular, the model is able to estimate the total spacecraft mass and its propulsive acceleration as a function of various design parameters such as the number of tethers and their length. A number of subsystem masses are calculated assuming existing or near-term E-sail technology. In light of the obtained performance estimates, an E-sail represents a promising propulsion system for a variety of transportation needs in the Solar System.

  1. Estimation of solar collector area for water heating in buildings of Malaysia

    Science.gov (United States)

    Manoj Kumar, Nallapaneni; Sudhakar, K.; Samykano, M.

    2018-04-01

    Solar thermal energy (STE) utilization for water heating at various sectorial levels became popular and still growing especially for buildings in the residential area. This paper aims to study and identify the solar collector area needed based on the user requirements in an efficient manner. A step by step mathematical approach is followed to estimate the area in Sq. m. Four different cases each having different hot water temperatures (45°, 50°C, 55°C, and 60°C) delivered by the solar water heating system (SWHS) for typical residential application at Kuala Lumpur City, Malaysia is analysed for the share of hot and cold water mix. As the hot water temperature levels increased the share of cold water mix is increased to satisfy the user requirement temperature, i.e. 40°C. It is also observed that as the share of hot water mix is reduced, the collector area can also be reduced. Following this methodology at the installation stage would help both the user and installers in the effective use of the solar resource.

  2. Reports on 1979 result of Sunshine Project. R and D on solar cooling/heating and hot-water supply system (R and D on system for multiple dwelling); 1979 nendo taiyo reidanbo oyobi kyuto system no kenkyu kaihatsu seika hokokusho. Shugo jutakuyo system no kenkyu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1980-03-01

    This R and D was intended to develop the following technologies for the purpose of putting into practice an innovative system that performs cooling/heating and hot-water supply for a multiple dwelling economically by solar energy: development of equipment constituting solar cooling/heating and hot-water supply system, and development of a system which uses such equipment and which is inexpensive and safe as well as easy for inspection and maintenance. In fiscal 1979, a study was implemented in which emphasis was placed on the experiment of a test housing with a solar cooling/heating and hot-water supply system incorporated for the purpose of proving the results of the research since fiscal 1974. In the overall flow of this project, the following research contents were partially performed or being performed successively during the period of seven years. (1) Examination of various methods, (2) Development of thermally driven freezer, (3) High performance heat collecter, (4) Heat storage device, (5) Types of multiple dwelling suitable for solar energy utilization, (6) Construction of experimental multiple dwelling, (7) Experiment in houses actually in use by people, (8) Confirmation of system improvements and results on the basis of experimental measurements, and (9) Evaluation as a solar system for multiple dwelling. (NEDO)

  3. Solar Water Heater

    Science.gov (United States)

    1993-01-01

    As a Jet Propulsion Laboratory (JPL) scientist Dr. Eldon Haines studied the solar energy source and solar water heating. He concluded he could build a superior solar water heating system using the geyser pumping principle. He resigned from JPL to develop his system and later form Sage Advance Corporation to market the technology. Haines' Copper Cricket residential system has no moving parts, is immune to freeze damage, needs no roof-mounted tanks, and features low maintenance. It provides 50-90 percent of average hot water requirements. A larger system, the Copper Dragon, has been developed for commercial installations.

  4. Self-Consistent Atmosphere Models of the Most Extreme Hot Jupiters

    Science.gov (United States)

    Lothringer, Joshua; Barman, Travis

    2018-01-01

    We present a detailed look at self-consistent PHOENIX atmosphere models of the most highly irradiated hot Jupiters known to exist. These hot Jupiters typically have equilibrium temperatures approaching and sometimes exceeding 3000 K, orbiting A, F, and early-G type stars on orbits less than 0.03 AU (10x closer than Mercury is to the Sun). The most extreme example, KELT-9b, is the hottest known hot Jupiter with a measured dayside temperature of 4600 K. Many of the planets we model have recently attracted attention with high profile discoveries, including temperature inversions in WASP-33b and WASP-121, changing phase curve offsets possibly caused by magnetohydrodymanic effects in HAT-P-7b, and TiO in WASP-19b. Our modeling provides a look at the a priori expectations for these planets and helps us understand these recent discoveries. We show that, in the hottest cases, all molecules are dissociated down to relatively high pressures. These planets may have detectable temperature inversions, more akin to thermospheres than stratospheres in that an optical absorber like TiO or VO is not needed. Instead, the inversions are created by a lack of cooling in the IR combined with heating from atoms and ions at UV and blue optical wavelengths. We also reevaluate some of the assumptions that have been made in retrieval analyses of these planets.

  5. Saphenous Venous Ablation with Hot Contrast in a Canine Model

    International Nuclear Information System (INIS)

    Prasad, Amit; Qian Zhong; Kirsch, David; Eissa, Marna; Narra, Pavan; Lopera, Jorge; Espinoza, Carmen G.; Castaneda, Wifrido

    2008-01-01

    Purpose. To determine the feasibility, efficacy, and safety of thermal ablation of the saphenous vein with hot contrast medium. Methods. Twelve saphenous veins of 6 dogs were percutaneously ablated with hot contrast medium. In all animals, ablation was performed in the vein of one leg, followed by ablation in the contralateral side 1 month later. An occlusion balloon catheter was placed in the infragenicular segment of the saphenous vein via a jugular access to prevent unwanted thermal effects on the non-target segment of the saphenous vein. After inflation of the balloon, 10 ml of hot contrast medium was injected under fluoroscopic control through a sheath placed in the saphenous vein above the ankle. A second 10 ml injection of hot contrast medium was made after 5 min in each vessel. Venographic follow-up of the ablated veins was performed at 1 month (n = 12) and 2 months (n = 6). Results. Follow-up venograms showed that all ablated venous segments were occluded at 1 month. In 6 veins which were followed up to 2 months, 4 (66%) remained occluded, 1 (16%) was partially patent, and the remaining vein (16%) was completely patent. In these latter 2 cases, an inadequate amount of hot contrast was delivered to the lumen due to a closed balloon catheter downstream which did not allow contrast to displace blood within the vessel. Discussion. Hot contrast medium thermal ablation of the saphenous vein appears feasible, safe, and effective in the canine model, provided an adequate amount of embolization agent is used

  6. Model for prediction of strip temperature in hot strip steel mill

    International Nuclear Information System (INIS)

    Panjkovic, Vladimir

    2007-01-01

    Proper functioning of set-up models in a hot strip steel mill requires reliable prediction of strip temperature. Temperature prediction is particularly important for accurate calculation of rolling force because of strong dependence of yield stress and strip microstructure on temperature. A comprehensive model was developed to replace an obsolete model in the Western Port hot strip mill of BlueScope Steel. The new model predicts the strip temperature evolution from the roughing mill exit to the finishing mill exit. It takes into account the radiative and convective heat losses, forced flow boiling and film boiling of water at strip surface, deformation heat in the roll gap, frictional sliding heat, heat of scale formation and the heat transfer between strip and work rolls through an oxide layer. The significance of phase transformation was also investigated. Model was tested with plant measurements and benchmarked against other models in the literature, and its performance was very good

  7. Model for prediction of strip temperature in hot strip steel mill

    Energy Technology Data Exchange (ETDEWEB)

    Panjkovic, Vladimir [BlueScope Steel, TEOB, 1 Bayview Road, Hastings Vic. 3915 (Australia)]. E-mail: Vladimir.Panjkovic@BlueScopeSteel.com

    2007-10-15

    Proper functioning of set-up models in a hot strip steel mill requires reliable prediction of strip temperature. Temperature prediction is particularly important for accurate calculation of rolling force because of strong dependence of yield stress and strip microstructure on temperature. A comprehensive model was developed to replace an obsolete model in the Western Port hot strip mill of BlueScope Steel. The new model predicts the strip temperature evolution from the roughing mill exit to the finishing mill exit. It takes into account the radiative and convective heat losses, forced flow boiling and film boiling of water at strip surface, deformation heat in the roll gap, frictional sliding heat, heat of scale formation and the heat transfer between strip and work rolls through an oxide layer. The significance of phase transformation was also investigated. Model was tested with plant measurements and benchmarked against other models in the literature, and its performance was very good.

  8. Investigations on stratification devices for hot water stores

    DEFF Research Database (Denmark)

    Andersen, Elsa; Furbo, Simon; Hampel, Matthias

    2008-01-01

    The significance of the thermal stratification for the energy efficiency of small solar-thermal hot water heat stores is pointed out. Exemplary the thermal stratification build-up with devices already marketed as well as with devices still in development has been investigated experimentally...

  9. Solar-Cooled Hotel in the Virgin Islands

    Science.gov (United States)

    Harber, H.

    1982-01-01

    Performance of solar cooling system is described in 21-page report. System provides cooling for public areas including ball rooms, restaurant, lounge, lobby and shops. Chilled water from solar-cooling system is also used to cool hot water from hotel's desalinization plant.

  10. Modelling radiative heat transfer inside a basin type solar still

    International Nuclear Information System (INIS)

    Madhlopa, A.

    2014-01-01

    Radiative heat transfer inside a basin type solar still has been investigated using two models with (model 1) and without (model 2) taking into account optical view factors. The coefficient of radiative heat exchange (h r,w-gc ) between the water and cover surfaces of a practical solar still was computed using the two models. Simulation results show that model 1 yields lower values of h r,w-gc and the root mean square error than model 2. It is therefore concluded that the accuracy of modelling the performance of a basin-type solar still can be improved by incorporating view factors. - Highlights: • Radiative heat transfer in a basin type solar still has been investigated. • Two models with and without view factors were used. • The model with view factors exhibits a lower magnitude of root mean square error. • View factors affect the accuracy of modelling the performance of the solar still

  11. Development of Solar Drying Model for Selected Cambodian Fish Species

    Science.gov (United States)

    Hubackova, Anna; Kucerova, Iva; Chrun, Rithy; Chaloupkova, Petra; Banout, Jan

    2014-01-01

    A solar drying was investigated as one of perspective techniques for fish processing in Cambodia. The solar drying was compared to conventional drying in electric oven. Five typical Cambodian fish species were selected for this study. Mean solar drying temperature and drying air relative humidity were 55.6°C and 19.9%, respectively. The overall solar dryer efficiency was 12.37%, which is typical for natural convection solar dryers. An average evaporative capacity of solar dryer was 0.049 kg·h−1. Based on coefficient of determination (R 2), chi-square (χ 2) test, and root-mean-square error (RMSE), the most suitable models describing natural convection solar drying kinetics were Logarithmic model, Diffusion approximate model, and Two-term model for climbing perch and Nile tilapia, swamp eel and walking catfish and Channa fish, respectively. In case of electric oven drying, the Modified Page 1 model shows the best results for all investigated fish species except Channa fish where the two-term model is the best one. Sensory evaluation shows that most preferable fish is climbing perch, followed by Nile tilapia and walking catfish. This study brings new knowledge about drying kinetics of fresh water fish species in Cambodia and confirms the solar drying as acceptable technology for fish processing. PMID:25250381

  12. [The interaction of soil micromycetes with "hot" particles in a model system].

    Science.gov (United States)

    Zhdanova, N N; Lashko, T N; Redchits, T I; Vasilevskaia, A I; Borisiuk, L G; Siniavskaia, O I; Gavriliuk, V I; Muzalev, P N

    1991-01-01

    A model system which permits observing for a long time and fixing interaction of fungi with a radiation source has been created on the basis of an isolated "hot" particle, deficient mineral medium (saccharose content 60 mg/l) and suspension of fungal conidia. Five species (six strains) of micromycetes isolated from radionuclide-contaminated soils and fifteen "hot" particles have been tested. It has been found out for the first time that Cladosporium cladosporioides and Penicillium roseo-purpureum are able actively overgrow "hot" particles whose radioactivity did not exceed 3.1-1.0(-7) Ci by gamma-spectrum and to destroy them 50-150 days later. Certain changes in morphology of fungi-destructors of "hot" particles are revealed. A problem on ecological significance of the found phenomenon is discussed.

  13. Solar combi systems

    DEFF Research Database (Denmark)

    Andersen, Elsa

    2007-01-01

    The focus in the present Ph.D. thesis is on the active use of solar energy for domestic hot water and space heating in so-called solar combi systems. Most efforts have been put into detailed investigations on the design of solar combi systems and on devices used for building up thermal...... the thermal behaviour of different components, and the theoretical investigations are used to study the influence of the thermal behaviour on the yearly thermal performance of solar combi systems. The experimental investigations imply detailed temperature measurements and flow visualization with the Particle...... Image Velocimetry measurement method. The theoretical investigations are based on the transient simulation program TrnSys and Computational Fluid Dynamics. The Ph.D. thesis demonstrates the influence on the thermal performance of solar combi systems of a number of different parameters...

  14. SAHA-S thermodynamic model of solar plasma

    International Nuclear Information System (INIS)

    Gryaznov, V.K.; Iosilevskiy, I.L.; Fortov, V.E.; Starostin, A.N.; Roerich, V.K.; Baturin, V.A.; Ayukov, S.V.

    2013-01-01

    The model SAHA-S based on the chemical picture for the equation of state of the solar plasma is presented. The effects of Coulomb interaction, exchange and diffraction effects, free electron degeneracy, relativistic corrections, radiation pressure contributions are taken into account. The solar model based on SAHA-S taking into account extended element composition and variation of heavy element abundance is represented and discussed. The comparison of the SAHA-S equation of state data for a hydrogen plasma with the results of other models applicable to the description of the solar plasma equation of state and the results obtained with the first principle methods are demonstrated and discussed. (copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. Single and multijunction silicon based thin film solar cells on a flexible substrate with absorber layers made by hot-wire CVD

    Science.gov (United States)

    Li, Hongbo

    2007-09-01

    With the worldwide growing concern about reliable energy supply and the environmental problems of fossil and nuclear energy production, the need for clean and sustainable energy sources is evident. Solar energy conversion, such as in photovoltaic systems, can play a major role in the urgently needed energy transition in electricity production. Solar cells based on thin film silicon and its alloys are a promising candidate that is capable of fulfilling the fast increasing demand of a reliable solar cell supply. The conventional method to deposit silicon thin films is based on plasma enhanced chemical vapour deposition (PECVD) techniques, which have the disadvantage of increasing film inhomogeneity at a high deposition rate when scaling up for the industrial production. In this thesis, we study the possibility of making high efficiency single and multijunction thin film silicon solar cells with the so-called hot-wire CVD technique, in which no strong electromagnetic field is involved in the deposition. Therefore, the up-scaling for industrial production is straightforward. We report and discuss our findings on the correlation of substrate surface rms roughness and the main output parameter of a solar cell, the open circuit voltage Voc of c-Si:H n i p cells. By considering all the possible reasons that could influence the Voc of such cells, we conclude that the near linear correlation of Voc and substrate surface rms roughness is the result the two most probable reasons: the unintentional doping through the cracks originated near the valleys of the substrate surface due to the in-diffusion of impurities, and the high density electrical defects formed by the collision of columnar silicon structures. Both of them relate to the morphology of substrate surface. Therefore, to have the best cell performance on a rough substrate surface, a good control on the substrate surface morphology is necessary. Another issue influencing the performance of c-Si:H solar cells is the

  16. Prototype solar house. Study of the scientific evaluation and feasibility of a research and development project

    Science.gov (United States)

    Bundschuh, V.; Grueter, J. W.; Kleemann, M.; Melis, M.; Stein, H. J.; Wagner, H. J.; Dittrich, A.; Pohlmann, D.

    1982-08-01

    A preliminary study was undertaken before a large scale project for construction and survey of about a hundred solar houses was launched. The notion of solar house was defined and the use of solar energy (hot water preparation, heating of rooms, heating of swimming pool, or a combination of these possibilities) were examined. A coherent measuring program was set up. Advantages and inconveniences of the large scale project were reviewed. Production of hot water, evaluation of different concepts and different fabrications of solar systems, coverage of the different systems, conservation of energy, failure frequency and failures statistics, durability of the installation, investment maintenance and energy costs were retained as study parameters. Different solar hot water production systems and the heat counter used for measurements are described.

  17. Cold-Climate Solar Domestic Hot Water Systems Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Burch, J.; Salasovich, J.; Hillman, T.

    2005-11-01

    The Solar Heating and Lighting Sub-program has set the key goal to reduce the cost of saved energy [Csav, defined as (total cost, $)/(total discounted savings, kWh_thermal)] for solar domestic water heaters (SDWH) by at least 50%. To determine if this goal is attainable and prioritize R&D for cold-climate SDWH, life-cycle analyses were done with hypothetical lower-cost components in glycol, drainback, and thermosiphon systems. Balance-of-system (BOS, everything but the collector) measures included replacing metal components with polymeric versions and system simplification. With all BOS measures in place, Csav could be reduced more than 50% with a low-cost, selectively-coated, glazed polymeric collector, and slightly less than 50% with either a conventional selective metal-glass or a non-selective glazed polymer collector. The largest percent reduction in Csav comes from replacing conventional pressurized solar storage tanks and metal heat exchangers with un-pressurized polymer tanks with immersed polymer heat exchangers, which could be developed with relatively low-risk R&D.

  18. Modeling of solar polygeneration plant

    Science.gov (United States)

    Leiva, Roberto; Escobar, Rodrigo; Cardemil, José

    2017-06-01

    In this work, a exergoeconomic analysis of the joint production of electricity, fresh water, cooling and process heat for a simulated concentrated solar power (CSP) based on parabolic trough collector (PTC) with thermal energy storage (TES) and backup energy system (BS), a multi-effect distillation (MED) module, a refrigeration absorption module, and process heat module is carried out. Polygeneration plant is simulated in northern Chile in Crucero with a yearly total DNI of 3,389 kWh/m2/year. The methodology includes designing and modeling a polygeneration plant and applying exergoeconomic evaluations and calculating levelized cost. Solar polygeneration plant is simulated hourly, in a typical meteorological year, for different solar multiple and hour of storage. This study reveals that the total exergy cost rate of products (sum of exergy cost rate of electricity, water, cooling and heat process) is an alternative method to optimize a solar polygeneration plant.

  19. Thermal performance parameters estimation of hot box type solar cooker by using artificial neural network

    Energy Technology Data Exchange (ETDEWEB)

    Kurt, Hueseyin; Atik, Kemal; Oezkaymak, Mehmet; Recebli, Ziyaddin [Zonguldak Karaelmas University, Karabuk Technical Education Faculty, 78200 Karabuk (Turkey)

    2008-02-15

    Work to date has shown that Artificial Neural Network (ANN) has not been used for predicting thermal performance parameters of a solar cooker. The objective of this study is to predict thermal performance parameters such as absorber plate, enclosure air and pot water temperatures of the experimentally investigated box type solar cooker by using the ANN. Data set is obtained from the box type solar cooker which was tested under various experimental conditions. A feed-forward neural network based on back propagation algorithm was developed to predict the thermal performance of solar cooker with and without reflector. Mathematical formulations derived from the ANN model are presented for each predicting temperatures. The experimental data set consists of 126 values. These were divided into two groups, of which the 96 values were used for training/learning of the network and the rest of the data (30 values) for testing/validation of the network performance. The performance of the ANN predictions was evaluated by comparing the prediction results with the experimental results. The results showed a good regression analysis with the correlation coefficients in the range of 0.9950-0.9987 and mean relative errors (MREs) in the range of 3.925-7.040% for the test data set. The regression coefficients indicated that the ANN model can successfully be used for the prediction of the thermal performance parameters of a box type solar cooker with a high degree of accuracy. (author)

  20. A thermo-electro-mechanical simulation model for hot wire cutting of EPS foam

    DEFF Research Database (Denmark)

    Petkov, Kiril; Hattel, Jesper Henri

    2016-01-01

    A one-dimensional thermo-electro-mechanical mathematical model describing the effects taking place within a Ni-Cr20% wire used in a hot-wire cutting process for free forming and rapid prototyping of expanded polystyrene (EPS) is investigated and simulated. The model implements and solves three semi...... cutting of EPS in contact with a cutting tool made of an electrically heated metal wire attached to a robot device. The finite difference method is used to solve the coupled equations in the two environments (domains) in which the hot-wire operates, namely air and EPS. The model is calibrated against...... experimentally obtained data. Novel findings are a transient temperature-dependent kerfwidth prediction and a relation between kerfwidth and the cutting angle as measured from the horizontal direction. These are important relations in the aim for higher geometrical accuracy of the hot-wire cutting process. (C...

  1. Investigating the impact of different thermal comfort models for zero energy buildings in hot climates

    NARCIS (Netherlands)

    Attia, S.G.; Hensen, J.L.M.

    2014-01-01

    The selection of a thermal comfort model has a major impact on energy consumption of Net Zero Energy Buildings (NZEBs) in hot climates. The objective of this paper is to compare the influence of using different comfort models for zero energy buildings in hot climates. The paper compares the impact

  2. The relation of collector and storage tank size in solar heating systems

    International Nuclear Information System (INIS)

    Çomaklı, Kemal; Çakır, Uğur; Kaya, Mehmet; Bakirci, Kadir

    2012-01-01

    Highlights: ► A storage tank is used in many solar water heating systems for the storage of hot water. ► Using larger storage tanks decrease the efficiency and increases the cost of the system. ► The optimum tank size for the collector area is very important for economic solar heating systems. ► The optimum sizes of the collectors and the storage tank are determined. - Abstract: The most popular method to benefit from the solar energy is to use solar water heating systems since it is one of the cheapest way to benefit from the solar energy. The investment cost of a solar water heating system is very low, and the maintenance costs are nearly zero. Using the solar energy for solar water heating (SWH) technology has been greatly improved during the past century. A storage tank is used in many solar water heating systems for the conservation of heat energy or hot water for use when some need it. In addition, domestic hot water consumption is strongly variable in many buildings. It depends on the geographical situation, also on the country customs, and of course on the type of building usage. Above all, it depends on the inhabitants’ specific lifestyle. For that reason, to provide the hot water for consumption at the desirable temperature whenever inhabitants require it, there must be a good relevance between the collectors and storage tank. In this paper, the optimum sizes of the collectors and the storage tank are determined to design more economic and efficient solar water heating systems. A program has been developed and validated with the experimental study and environmental data. The environmental data were obtained through a whole year of operation for Erzurum, Turkey.

  3. The virtual enhancements - solar proton event radiation (VESPER) model

    Science.gov (United States)

    Aminalragia-Giamini, Sigiava; Sandberg, Ingmar; Papadimitriou, Constantinos; Daglis, Ioannis A.; Jiggens, Piers

    2018-02-01

    A new probabilistic model introducing a novel paradigm for the modelling of the solar proton environment at 1 AU is presented. The virtual enhancements - solar proton event radiation model (VESPER) uses the European space agency's solar energetic particle environment modelling (SEPEM) Reference Dataset and produces virtual time-series of proton differential fluxes. In this regard it fundamentally diverges from the approach of existing SPE models that are based on probabilistic descriptions of SPE macroscopic characteristics such as peak flux and cumulative fluence. It is shown that VESPER reproduces well the dataset characteristics it uses, and further comparisons with existing models are made with respect to their results. The production of time-series as the main output of the model opens a straightforward way for the calculation of solar proton radiation effects in terms of time-series and the pairing with effects caused by trapped radiation and galactic cosmic rays.

  4. Analytical models for the rewetting of hot surfaces

    International Nuclear Information System (INIS)

    Olek, S.

    1988-10-01

    Some aspects concerning analytical models for the rewetting of hot surface are discussed. These include the problems with applying various forms of boundary conditions, compatibility of boundary conditions with the physics of the rewetting problems, recent analytical models, the use of the separation of variables method versus the Wiener-Hopf technique, and the use of transformations. The report includes an updated list of rewetting models as well as benchmark solutions in tabular form for several models. It should be emphasized that this report is not meant to cover the topic of rewetting models. It merely discusses some points which are less commonly referred to in the literature. 93 refs., 3 figs., 22 tabs

  5. Co-Production Performance Evaluation of a Novel Solar Combi System for Simultaneous Pure Water and Hot Water Supply in Urban Households of UAE

    Directory of Open Access Journals (Sweden)

    Nutakki Tirumala Uday Kumar

    2017-04-01

    Full Text Available Water is the most desirable and sparse resource in Gulf cooperation council (GCC region. Utilization of point-of-use (POU water treatment devices has been gaining huge market recently due to increase in knowledge of urban population on health related issues over contaminants in decentralized water distribution networks. However, there is no foolproof way of knowing whether the treated water is free of contaminants harmful for drinking and hence reliance on certified bottled water has increased worldwide. The bottling process right from treatment to delivery is highly unsustainable due to huge energy demand along the supply chain. As a step towards sustainability, we investigated various ways of coupling of membrane distillation (MD process with solar domestic heaters for co-production of domestic heat and pure water. Performance dynamics of various integration techniques have been evaluated and appropriate configuration has been identified for real scale application. A solar combi MD (SCMD system is experimentally tested for single household application for production 20 L/day of pure water and 250 L/day of hot water simultaneously without any auxiliary heating device. The efficiency of co-production system is compared with individual operation of solar heaters and solar membrane distillation.

  6. Huge opportunity for solar cooling

    International Nuclear Information System (INIS)

    Rowe, Daniel

    2014-01-01

    In Europe more than 400 solar cooling systems have been installed. By contrast, only a small number of solar cooling installations exist in Australia - primarily adsorption and absorption systems for commercial and hospitals - although these systems are growing. As with other renewable energy technologies, cost is a challenge. However solar cooling is currently competitive with other technologies, with some suggesting that system costs have been decreasing by about 20% per annum in recent times. Australia is also leading efforts in the development of residential solar desiccant technology, currently commercialising Australian-developed technology. Commercial and industrial enterprises are increasingly aware of the impact of demand charges, the potential to install technology as a hedge against future energy price rises and opportunities associated with increased on-site generation and reduced reliance on the grid, often necessitating on-site demand reduction and management. They are also driven by environmental and corporate social responsibility objectives as well as the opportunity for energy independence and uninterruptible operation. Interestingly, many of these interests are mirrdred at residential level, inspiring CSIRO's commercialisation of a domestic scale solar air conditioner with Australian manufacturer Brevis Climate Systems. Australia and other countries are increasingly aware of solar cooling as technology which can reduce or replace grid-powered cooling, particularly in applications where large building thermal energy requirements exist. In these applications, heating, cooling and hot water are generated and used in large amounts and the relative amounts of each can be varied dynamically, depending on building requirements. Recent demonstrations of solar cooling technology in Australia include Hunter TAFE's Solar Desiccant Cooling System - which provides heating, cooling and hot water to commercial training kitchens and classrooms - GPT

  7. Diffuse solar radiation estimation models for Turkey's big cities

    International Nuclear Information System (INIS)

    Ulgen, Koray; Hepbasli, Arif

    2009-01-01

    A reasonably accurate knowledge of the availability of the solar resource at any place is required by solar engineers, architects, agriculturists, and hydrologists in many applications of solar energy such as solar furnaces, concentrating collectors, and interior illumination of buildings. For this purpose, in the past, various empirical models (or correlations) have been developed in order to estimate the solar radiation around the world. This study deals with diffuse solar radiation estimation models along with statistical test methods used to statistically evaluate their performance. Models used to predict monthly average daily values of diffuse solar radiation are classified in four groups as follows: (i) From the diffuse fraction or cloudness index, function of the clearness index, (ii) From the diffuse fraction or cloudness index, function of the relative sunshine duration or sunshine fraction, (iii) From the diffuse coefficient, function of the clearness index, and (iv) From the diffuse coefficient, function of the relative sunshine duration or sunshine fraction. Empirical correlations are also developed to establish a relationship between the monthly average daily diffuse fraction or cloudness index (K d ) and monthly average daily diffuse coefficient (K dd ) with the monthly average daily clearness index (K T ) and monthly average daily sunshine fraction (S/S o ) for the three big cities by population in Turkey (Istanbul, Ankara and Izmir). Although the global solar radiation on a horizontal surface and sunshine duration has been measured by the Turkish State Meteorological Service (STMS) over all country since 1964, the diffuse solar radiation has not been measured. The eight new models for estimating the monthly average daily diffuse solar radiation on a horizontal surface in three big cites are validated, and thus, the most accurate model is selected for guiding future projects. The new models are then compared with the 32 models available in the

  8. Energy behavior of solar hot water systems under different conditions

    International Nuclear Information System (INIS)

    Fuentes Lombá, Osmanys; Torres Ten, Alonso; Arzuaga Machado, Yusnel; Hernández, Massipe J. Raúl; Cueva Gonzales, Wagner

    2017-01-01

    By means of numerical simulations in TRNSYS v14 the influence of the solar absorption area of a system for heating water with solar energy, composed by a flat solar collector and a tank thermo-accumulator, on its energy efficiency. For the study, the solar collectors EDWARDS, ISOFOTÓN 1, ISOFOTÓN 2, MADE, ROLDAN and IBERSOLAR of absorption area 2, 1,9, 1,88, 2, 1,9 and 2,3 m2 respectively were chosen. For each collector, the energy performance was simulated for one year, setting 200 L for the accumulation volume and 50 °C for the intake temperature. Despite the different characteristics of each collector, their behavior is quite similar showing a very mature technology. (author)

  9. A Model for Hourly Solar Radiation Data Generation from Daily Solar Radiation Data Using a Generalized Regression Artificial Neural Network

    OpenAIRE

    Khatib, Tamer; Elmenreich, Wilfried

    2015-01-01

    This paper presents a model for predicting hourly solar radiation data using daily solar radiation averages. The proposed model is a generalized regression artificial neural network. This model has three inputs, namely, mean daily solar radiation, hour angle, and sunset hour angle. The output layer has one node which is mean hourly solar radiation. The training and development of the proposed model are done using MATLAB and 43800 records of hourly global solar radiation. The results show that...

  10. Steam generator design for solar towers using solar salt as heat transfer fluid

    Science.gov (United States)

    González-Gómez, Pedro Ángel; Petrakopoulou, Fontina; Briongos, Javier Villa; Santana, Domingo

    2017-06-01

    Since the operation of a concentrating solar power plant depends on the intermittent character of solar energy, the steam generator is subject to daily start-ups, stops and load variations. Faster start-up and load changes increase the plant flexibility and the daily energy production. However, it involves high thermal stresses on thick-walled components. Continuous operational conditions may eventually lead to a material failure. For these reasons, it is important to evaluate the transient behavior of the proposed designs in order to assure the reliability. The aim of this work is to analyze different steam generator designs for solar power tower plants using molten salt as heat transfer fluid. A conceptual steam generator design is proposed and associated heat transfer areas and steam drum size are calculated. Then, dynamic models for the main parts of the steam generator are developed to represent its transient performance. A temperature change rate that ensures safe hot start-up conditions is studied for the molten salt. The thermal stress evolution on the steam drum is calculated as key component of the steam generator.

  11. Development of Solar Drying Model for Selected Cambodian Fish Species

    Directory of Open Access Journals (Sweden)

    Anna Hubackova

    2014-01-01

    Full Text Available A solar drying was investigated as one of perspective techniques for fish processing in Cambodia. The solar drying was compared to conventional drying in electric oven. Five typical Cambodian fish species were selected for this study. Mean solar drying temperature and drying air relative humidity were 55.6°C and 19.9%, respectively. The overall solar dryer efficiency was 12.37%, which is typical for natural convection solar dryers. An average evaporative capacity of solar dryer was 0.049 kg·h−1. Based on coefficient of determination (R2, chi-square (χ2 test, and root-mean-square error (RMSE, the most suitable models describing natural convection solar drying kinetics were Logarithmic model, Diffusion approximate model, and Two-term model for climbing perch and Nile tilapia, swamp eel and walking catfish and Channa fish, respectively. In case of electric oven drying, the Modified Page 1 model shows the best results for all investigated fish species except Channa fish where the two-term model is the best one. Sensory evaluation shows that most preferable fish is climbing perch, followed by Nile tilapia and walking catfish. This study brings new knowledge about drying kinetics of fresh water fish species in Cambodia and confirms the solar drying as acceptable technology for fish processing.

  12. Solar Water Heating System for Biodiesel Production

    Directory of Open Access Journals (Sweden)

    Syaifurrahman

    2018-01-01

    Full Text Available Nowadays, electricity become very expensive thing in some remote areas. Energy from solar panels give the solution as renewable energy that is environment friendly. West Borneo is located on the equator where the sun shines for almost 10-15 hours/day. Solar water heating system which is includes storage tank and solar collections becomes a cost-effective way to generate the energy. Solar panel heat water is delivered to water in storage tank. Hot water is used as hot fluid in biodiesel jacked reactor. The purposes of this research are to design Solar Water Heating System for Biodiesel Production and measure the rate of heat-transfer water in storage tank. This test has done for 6 days, every day from 8.30 am until 2.30 pm. Storage tank and collection are made from stainless steel and polystyrene a well-insulated. The results show that the heater can be reach at 50ºC for ±2.5 hours and the maximum temperature is 62ºC where the average of light intensity is 1280 lux.

  13. Solar Water Heating System for Biodiesel Production

    Science.gov (United States)

    Syaifurrahman; Usman, A. Gani; Rinjani, Rakasiwi

    2018-02-01

    Nowadays, electricity become very expensive thing in some remote areas. Energy from solar panels give the solution as renewable energy that is environment friendly. West Borneo is located on the equator where the sun shines for almost 10-15 hours/day. Solar water heating system which is includes storage tank and solar collections becomes a cost-effective way to generate the energy. Solar panel heat water is delivered to water in storage tank. Hot water is used as hot fluid in biodiesel jacked reactor. The purposes of this research are to design Solar Water Heating System for Biodiesel Production and measure the rate of heat-transfer water in storage tank. This test has done for 6 days, every day from 8.30 am until 2.30 pm. Storage tank and collection are made from stainless steel and polystyrene a well-insulated. The results show that the heater can be reach at 50ºC for ±2.5 hours and the maximum temperature is 62ºC where the average of light intensity is 1280 lux.

  14. THERMAL RESPONSE OF A SOLAR-LIKE ATMOSPHERE TO AN ELECTRON BEAM FROM A HOT JUPITER: A NUMERICAL EXPERIMENT

    International Nuclear Information System (INIS)

    Gu, P.-G.; Suzuki, Takeru K.

    2009-01-01

    We investigate the thermal response of the atmosphere of a solar-type star to an electron beam injected from a hot Jupiter by performing a one-dimensional MHD numerical experiment with nonlinear wave dissipation, radiative cooling, and thermal conduction. In our experiment, the stellar atmosphere is non-rotating and is modeled as a one-dimensional open flux tube expanding super-radially from the stellar photosphere to the planet. An electron beam is assumed to be generated from the reconnection site of the planet's magnetosphere. The effects of the electron beam are then implemented in our simulation as dissipation of the beam momentum and energy at the base of the corona where the Coulomb collisions become effective. When the sufficient energy is supplied by the electron beam, a warm region forms in the chromosphere. This warm region greatly enhances the radiative fluxes corresponding to the temperature of the chromosphere and transition region. The warm region can also intermittently contribute to the radiative flux associated with the coronal temperature due to the thermal instability. However, owing to the small area of the heating spot, the total luminosity of the beam-induced chromospheric radiation is several orders of magnitude smaller than the observed Ca II emissions from HD 179949.

  15. Co-existence of two plasma phases in solar and AGN coronas

    Directory of Open Access Journals (Sweden)

    Kubičela A.

    1998-01-01

    Full Text Available Here we have juxtaposed two distant cosmic locations of the Sun and AGN where neutral hydrogen appears in a close connection with hot coronas. Besides the solar photosphere, chromosphere and prominences where the presence of neutral hydrogen is well established, its emission quite high in hot solar corona is still puzzling. Some of earlier observations where Hα emission in solar corona was detected in eclipse and in daily coronagraphic observations are reviewed. A proper theoretical explanation of this cold chromospheric-type emission in the hot corona does not exist yet. On the other side, a similar emission of hydrogen lines is present in Active Galactic Nuclei (AGNs. Much research work is currently being done in this field. We outline some of the concepts of the AGN structure prevailing in the astrophysics today.

  16. Developing a new solar radiation estimation model based on Buckingham theorem

    Science.gov (United States)

    Ekici, Can; Teke, Ismail

    2018-06-01

    While the value of solar radiation can be expressed physically in the days without clouds, this expression becomes difficult in cloudy and complicated weather conditions. In addition, solar radiation measurements are often not taken in developing countries. In such cases, solar radiation estimation models are used. Solar radiation prediction models estimate solar radiation using other measured meteorological parameters those are available in the stations. In this study, a solar radiation estimation model was obtained using Buckingham theorem. This theory has been shown to be useful in predicting solar radiation. In this study, Buckingham theorem is used to express the solar radiation by derivation of dimensionless pi parameters. This derived model is compared with temperature based models in the literature. MPE, RMSE, MBE and NSE error analysis methods are used in this comparison. Allen, Hargreaves, Chen and Bristow-Campbell models in the literature are used for comparison. North Dakota's meteorological data were used to compare the models. Error analysis were applied through the comparisons between the models in the literature and the model that is derived in the study. These comparisons were made using data obtained from North Dakota's agricultural climate network. In these applications, the model obtained within the scope of the study gives better results. Especially, in terms of short-term performance, it has been found that the obtained model gives satisfactory results. It has been seen that this model gives better accuracy in comparison with other models. It is possible in RMSE analysis results. Buckingham theorem was found useful in estimating solar radiation. In terms of long term performances and percentage errors, the model has given good results.

  17. Particle-in-cell studies of laser-driven hot spots and a statistical model for mesoscopic properties of Raman backscatter

    International Nuclear Information System (INIS)

    Albright, B.J.; Yin, L.; Bowers, K.J.; Kline, J.L.; Montgomery, D.S.; Fernandez, J.C.; Daughton, W.

    2006-01-01

    The authors use explicit particle-in-cell simulations to model stimulated scattering processes in media with both solitary and multiple laser hot spots. These simulations indicate coupling among hot spots, whereby scattered light, plasma waves, and hot electrons generated in one laser hot spot may propagate to neighboring hot spots, which can be destabilized to enhanced backscatter. A nonlinear statistical model of a stochastic beam exhibiting this coupled behavior is described here. Calibration of the model using particle-in-cell simulations is performed, and a threshold is derived for 'detonation' of the beam to high reflectivity. (authors)

  18. The Pore Collapse “Hot-Spots” Model Coupled with Brittle Damage for Solid Explosives

    Directory of Open Access Journals (Sweden)

    L. R. Cheng

    2014-01-01

    Full Text Available This paper is devoted to the building of a numerical pore collapse model with “hot-spots” formation for the impacted damage explosives. According to damage mechanical evolution of brittle material, the one-dimensional elastic-viscoplastic collapse model was improved to incorporate the impact damage during the dynamic collapse of pores. The damage of explosives was studied using the statistical crack mechanics (SCRAM. The effects of the heat conduction and the chemical reaction were taken into account in the formation of “hot-spots.” To verify the improved model, numerical simulations were carried out for different pressure states and used to model a multiple-impact experiment. The results show that repeated weak impacts can lead to the collapse of pores and the “hot-spots” may occur due to the accumulation of internal defects accompanied by the softening of explosives.

  19. DETAILED MODELLING OF CHARGING BEHAVIOUR OF SMART SOLAR TANKS

    DEFF Research Database (Denmark)

    Fan, Jianhua; Andersen, Elsa; Furbo, Simon

    2010-01-01

    The charging behaviour of smart solar tanks for solar combisystems for one-family houses is investigated with detailed Computational Fluid Dynamics (CFD) modelling and Particle Image Velocimetry (PIV) measurements. The smart solar tank can be charged with a variable auxiliary volume fitted...... or by an electric heating element in a side-arm mounted on the side of the tank. Detailed CFD models of the smart tanks are built with different mesh densities in the tank and in the side-arm. The thermal conditions of the tank during charging are calculated with the CFD models. The fluid flow and temperature...... by the mesh densities, the distribution of computational cells, the physical model and time steps used in the simulations. The findings of the investigations will be used as guidance for creation of CFD models for optimal design of smart solar tanks....

  20. Ensemble downscaling in coupled solar wind-magnetosphere modeling for space weather forecasting.

    Science.gov (United States)

    Owens, M J; Horbury, T S; Wicks, R T; McGregor, S L; Savani, N P; Xiong, M

    2014-06-01

    Advanced forecasting of space weather requires simulation of the whole Sun-to-Earth system, which necessitates driving magnetospheric models with the outputs from solar wind models. This presents a fundamental difficulty, as the magnetosphere is sensitive to both large-scale solar wind structures, which can be captured by solar wind models, and small-scale solar wind "noise," which is far below typical solar wind model resolution and results primarily from stochastic processes. Following similar approaches in terrestrial climate modeling, we propose statistical "downscaling" of solar wind model results prior to their use as input to a magnetospheric model. As magnetospheric response can be highly nonlinear, this is preferable to downscaling the results of magnetospheric modeling. To demonstrate the benefit of this approach, we first approximate solar wind model output by smoothing solar wind observations with an 8 h filter, then add small-scale structure back in through the addition of random noise with the observed spectral characteristics. Here we use a very simple parameterization of noise based upon the observed probability distribution functions of solar wind parameters, but more sophisticated methods will be developed in the future. An ensemble of results from the simple downscaling scheme are tested using a model-independent method and shown to add value to the magnetospheric forecast, both improving the best estimate and quantifying the uncertainty. We suggest a number of features desirable in an operational solar wind downscaling scheme. Solar wind models must be downscaled in order to drive magnetospheric models Ensemble downscaling is more effective than deterministic downscaling The magnetosphere responds nonlinearly to small-scale solar wind fluctuations.

  1. Dynamic Modeling of the Solar Field in Parabolic Trough Solar Power Plants

    Directory of Open Access Journals (Sweden)

    Lourdes A. Barcia

    2015-11-01

    Full Text Available Parabolic trough solar power plants use a thermal fluid to transfer thermal energy from solar radiation to a water-steam Rankine cycle in order to drive a turbine that, coupled to an electrical generator, produces electricity. These plants have a heat transfer fluid (HTF system with the necessary elements to transform solar radiation into heat and to transfer that thermal energy to the water-steam exchangers. In order to get the best possible performance in the Rankine cycle and, hence, in the thermal plant, it is necessary that the thermal fluid reach its maximum temperature when leaving the solar field (SF. Also, it is mandatory that the thermal fluid does not exceed the maximum operating temperature of the HTF, above which it degrades. It must be noted that the optimal temperature of the thermal fluid is difficult to obtain, since solar radiation can change abruptly from one moment to another. The aim of this document is to provide a model of an HTF system that can be used to optimize the control of the temperature of the fluid without interfering with the normal operation of the plant. The results obtained with this model will be contrasted with those obtained in a real plant.

  2. Investigation of solar photovoltaic module power output by various models

    International Nuclear Information System (INIS)

    Jakhrani, A.Q.; Othman, A.K.; Rigit, A.R.H.; Baini, R.

    2012-01-01

    This paper aims to investigate the power output of a solar photovoltaic module by various models and to formulate a suitable model for predicting the performance of solar photovoltaic modules. The model was used to correct the configurations of solar photovoltaic systems for sustainable power supply. Different types of models namely the efficiency, power, fill factor and current-voltage characteristic curve models have been reviewed. It was found that the examined models predicted a 40% yield of the rated power in cloudy weather conditions and up to 80% in clear skies. The models performed well in terms of electrical efficiency in cloudy days if the influence of low irradiance were incorporated. Both analytical and numerical methods were employed in the formulation of improved model which gave +- 2% error when compared with the rated power output of solar photovoltaic module. The proposed model is more practical in terms of number of variables used and acceptable performance in humid atmospheres. Therefore, it could be useful for the estimation of power output of the solar photovoltaic systems in Sarawak region. (author)

  3. Ignition conditions relaxation for central hot-spot ignition with an ion-electron non-equilibrium model

    Science.gov (United States)

    Fan, Zhengfeng; Liu, Jie

    2016-10-01

    We present an ion-electron non-equilibrium model, in which the hot-spot ion temperature is higher than its electron temperature so that the hot-spot nuclear reactions are enhanced while energy leaks are considerably reduced. Theoretical analysis shows that the ignition region would be significantly enlarged in the hot-spot rhoR-T space as compared with the commonly used equilibrium model. Simulations show that shocks could be utilized to create and maintain non-equilibrium conditions within the hot spot, and the hot-spot rhoR requirement is remarkably reduced for achieving self-heating. In NIF high-foot implosions, it is observed that the x-ray enhancement factors are less than unity, which is not self-consistent and is caused by assuming Te =Ti. And from this non-consistency, we could infer that ion-electron non-equilibrium exists in the high-foot implosions and the ion temperature could be 9% larger than the equilibrium temperature.

  4. Modeling deflagration waves out of hot spots

    Science.gov (United States)

    Partom, Yehuda

    2017-01-01

    It is widely accepted that shock initiation and detonation of heterogeneous explosives comes about by a two-step process known as ignition and growth. In the first step a shock sweeping through an explosive cell (control volume) creates hot spots that become ignition sites. In the second step, deflagration waves (or burn waves) propagate out of those hot spots and transform the reactant in the cell into reaction products. The macroscopic (or average) reaction rate of the reactant in the cell depends on the speed of those deflagration waves and on the average distance between neighboring hot spots. Here we simulate the propagation of deflagration waves out of hot spots on the mesoscale in axial symmetry using a 2D hydrocode, to which we add heat conduction and bulk reaction. The propagation speed of the deflagration waves may depend on both pressure and temperature. It depends on pressure for quasistatic loading near ambient temperature, and on temperature at high temperatures resulting from shock loading. From the simulation we obtain deflagration fronts emanating out of the hot spots. For 8 to 13 GPa shocks, the emanating fronts propagate as deflagration waves to consume the explosive between hot spots. For higher shock levels deflagration waves may interact with the sweeping shock to become detonation waves on the mesoscale. From the simulation results we extract average deflagration wave speeds.

  5. Solar Flux Deposition And Heating Rates In Jupiter's Atmosphere

    Science.gov (United States)

    Perez-Hoyos, Santiago; Sánchez-Lavega, A.

    2009-09-01

    We discuss here the solar downward net flux in the 0.25 - 2.5 µm range in the atmosphere of Jupiter and the associated heating rates under a number of vertical cloud structure scenarios focusing in the effect of clouds and hazes. Our numerical model is based in the doubling-adding technique to solve the radiative transfer equation and it includes gas absorption by CH4, NH3 and H2, in addition to Rayleigh scattering by a mixture of H2 plus He. Four paradigmatic Jovian regions have been considered (hot-spots, belts, zones and Polar Regions). The hot-spots are the most transparent regions with downward net fluxes of 2.5±0.5 Wm-2 at the 6 bar level. The maximum solar heating is 0.04±0.01 K/day and occurs above 1 bar. Belts and zones characterization result in a maximum net downward flux of 0.5 Wm-2 at 2 bar and 0.015 Wm-2 at 6 bar. Heating is concentrated in the stratospheric and tropospheric hazes. Finally, Polar Regions are also explored and the results point to a considerable stratospheric heating of 0.04±0.02 K/day. In all, these calculations suggest that the role of the direct solar forcing in the Jovian atmospheric dynamics is limited to the upper 1 - 2 bar of the atmosphere except in the hot-spot areas. Acknowledgments: This work has been funded by Spanish MEC AYA2006-07735 with FEDER support and Grupos Gobierno Vasco IT-464-07.

  6. Application of cooling with solid dissecants in solar heating and heating water systems; Aplicacion de la refrigeracion con desecantes solidos en sistemas solares de calefaccion y agua caliente sanitaria

    Energy Technology Data Exchange (ETDEWEB)

    Carrillo Andres, A.; Cejudo Lopez, J. M.; Dominguez Munoz, F.; Serrano Casares, F.

    2004-07-01

    Solar thermal systems designed for domestic hot water and space heating, must be dimensioned on a larger scale than for purely domestic hot water. In summer, when there are many days when no heating is required, the oversized collector area leads to frequent stagnancy situations. In order to use the excess of collector area in summer, a solar desiccant cooling system can be integrated in the solar thermal system. This paper study such combination, using computer simulations with the program TRNSYS, Klein(2000). (Author)

  7. Solar Energy Demonstrations

    Science.gov (United States)

    1979-01-01

    Solar energy furnishes all of the heating and hot water needs, plus 80 percent of the air conditioning, for the two-story Reedy Creek building. A unique feature of this installation is that the 16 semi-cylindrical solar collectors (center photo on opposite page with closeup of a single collector below it) are not mounted atop the roof as is customary, they actually are the roof. This arrangement eliminates the usual trusses, corrugated decking and insulating concrete in roof construction; that, in turn, reduces overall building costs and makes the solar installation more attractive economically. The Reedy Creek collectors were designed and manufactured by AAI Corporation of Baltimore, Maryland.

  8. Solar Convective Furnace for Metals Processing

    Science.gov (United States)

    Patidar, Deepesh; Tiwari, Sheetanshu; Sharma, Piyush; Pardeshi, Ravindra; Chandra, Laltu; Shekhar, Rajiv

    2015-11-01

    Metals processing operations, primarily soaking, heat treatment, and melting of metals are energy-intensive processes using fossil fuels, either directly or indirectly as electricity, to operate furnaces at high temperatures. Use of concentrated solar energy as a source of heat could be a viable "green" option for industrial heat treatment furnaces. This paper introduces the concept of a solar convective furnace which utilizes hot air generated by an open volumetric air receiver (OVAR)-based solar tower technology. The potential for heating air above 1000°C exists. Air temperatures of 700°C have already been achieved in a 1.5-MWe volumetric air receiver demonstration plant. Efforts to retrofit an industrial aluminium soaking furnace for integration with a solar tower system are briefly described. The design and performance of an OVAR has been discussed. A strategy for designing a 1/15th-scale model of an industrial aluminium soaking furnace has been presented. Preliminary flow and thermal simulation results suggest the presence of recirculating flow in existing furnaces that could possibly result in non-uniform heating of the slabs. The multifarious uses of concentrated solar energy, for example in smelting, metals processing, and even fuel production, should enable it to overcome its cost disadvantage with respect to solar photovoltaics.

  9. Modelling of mid-infrared interferometric signature of hot exozodiacal dust emission

    Science.gov (United States)

    Kirchschlager, Florian; Wolf, Sebastian; Brunngräber, Robert; Matter, Alexis; Krivov, Alexander V.; Labdon, Aaron

    2018-01-01

    Hot exozodiacal dust emission was detected in recent surveys around two dozen main-sequence stars at distances of less than 1 au using the H- and K-band interferometry. Due to the high contrast as well as the small angular distance between the circumstellar dust and the star, direct observation of this dust component is challenging. An alternative way to explore the hot exozodiacal dust is provided by mid-infrared interferometry. We analyse the L, M and N bands interferometric signature of this emission in order to find stronger constraints for the properties and the origin of the hot exozodiacal dust. Considering the parameters of nine debris disc systems derived previously, we model the discs in each of these bands. We find that the M band possesses the best conditions to detect hot dust emission, closely followed by L and N bands. The hot dust in three systems - HD 22484 (10 Tau), HD 102647 (β Leo) and HD 177724 (ζ Aql) - shows a strong signal in the visibility functions, which may even allow one to constrain the dust location. In particular, observations in the mid-infrared could help to determine whether the dust piles up at the sublimation radius or is located at radii up to 1 au. In addition, we explore observations of the hot exozodiacal dust with the upcoming mid-infrared interferometer Multi AperTure mid-Infrared SpectroScopic Experiment (MATISSE) at the Very Large Telescope Interferometer.

  10. Modeling and numerical simulation of a novel solar-powered absorption air conditioning system driven by a bubble pump with energy storage

    Institute of Scientific and Technical Information of China (English)

    QIU Jia; LIANG Jian; CHEN GuangMing; DU RuXu

    2009-01-01

    This paper presents a novel solar-powered absorption air conditioning system driven by a bubble pump with energy storage. It solves the problem of unreliable solar energy supply by storing the working fluids and hence, functions 24 h per day. First, the working principles are described and the dynamic models for the primary energy storage components are developed. Then, the system is evaluated based on a numerical simulation. Based on the meteorological data of a typical day in a subtropical area, with the area of a solar collector being set at 19.15 m2, whilst the initial charging mass, mass fraction and temperature of the solution are respectively set at 379.5 kg, 54.16% and 34.5 ℃, it is found that the respective coefficients of performance (COP) of the air conditioning system and the en-tire system (including the solar panel) are 0.7771 and 0.4372. In particular, the energy storage density of the system is 206.69 MJ/m3 which is much greater than those of chilled water or hot water storage systems under comparable conditions. This makes the new system much more compact and efficient. Finally, an automatic control strategy is given to achieve the highest COP when solar energy fluctuates.

  11. Low-cost personal cooling in hot humid offices. Feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Gunnarsen, L [Danish Building Research Inst., (Denmark); Santos, A [Univ. of the Philippines, Diliman (Philippines)

    1997-05-01

    A solution, based on low-cost solar-powered air drying, to heat stress in buildings located in developing countries with a hot and humid climate is presented. The air-drying facilities are described and a validation of the ensuing benefits through comprehensive human exposure studies is given. A prototype of a solar powered supply system for dried air was constructed and supply air was led to six personal units for ventilation and cooling placed in cubicles simulating office workplaces. 123 heat-acclimatized people were exposed for one hour in each of the cubicles. It is concluded that drying indoor air reduces heat stress among heat-adapted people in hot and humid offices and that the low-cost solar powered air drying system functioned satisfactorily , although some improvements are recommended. The drying power of the sun can be stored in recovered silica gel beads and used for other purposes. It is suggested that further research could explore the possibility of desiccant drying of agricultural products during the rainy season. (ARW) 30 refs.

  12. A HOT GAP AROUND JUPITER'S ORBIT IN THE SOLAR NEBULA

    Energy Technology Data Exchange (ETDEWEB)

    Turner, N. J.; Choukroun, M.; Castillo-Rogez, J.; Bryden, G., E-mail: neal.turner@jpl.nasa.gov [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

    2012-04-01

    The Sun was an order of magnitude more luminous during the first few hundred thousand years of its existence, due in part to the gravitational energy released by material accreting from the solar nebula. If Jupiter was already near its present mass, the planet's tides opened an optically thin gap in the nebula. Using Monte Carlo radiative transfer calculations, we show that sunlight absorbed by the nebula and re-radiated into the gap raised temperatures well above the sublimation threshold for water ice, with potentially drastic consequences for the icy bodies in Jupiter's feeding zone. Bodies up to a meter in size were vaporized within a single orbit if the planet was near its present location during this early epoch. Dust particles lost their ice mantles, and planetesimals were partially to fully devolatilized, depending on their size. Scenarios in which Jupiter formed promptly, such as those involving a gravitational instability of the massive early nebula, must cope with the high temperatures. Enriching Jupiter in the noble gases through delivery trapped in clathrate hydrates will be more difficult, but might be achieved by either forming the planet much farther from the star or capturing planetesimals at later epochs. The hot gap resulting from an early origin for Jupiter also would affect the surface compositions of any primordial Trojan asteroids.

  13. Evolution of hot galactic flows

    International Nuclear Information System (INIS)

    Loewenstein, M.; Mathews, W.G.

    1987-01-01

    The time-dependent equations describing galactic flows, including detailed models for the evolving source terms, are integrated over a Hubble time for two elliptical galaxies with total masses of 3.1 x 10 to the 12th and 8.3 x 10 to the 12th solar masses, 90 percent of which resides in extended, nonluminous halos. The standard supernova rate of Tammann and a rate 4 times smaller are considered for each galaxy model. The combination of the extended gravitational potential of the dark halo and the time-dependent source terms generally lead to the development of massive, quasi-hydrostatic, nearly isothermal distributions of gas at about 10 to the 7th K with cooling inflows inside their galactic cores. For the less massive galaxy with the higher supernova rate, however, a low-luminosity supersonic galactic wind develops. The effects of a lowered metal abundance, thermal conduction, and the absence of a massive halo are explored separately for one of the present models. The X-ray luminosities of the hot gas in the models with dark halos and the lower supernova rate are in good agreement with Einstein observations of early-type galaxies. 42 references

  14. Raster-Based Approach to Solar Pressure Modeling

    Science.gov (United States)

    Wright, Theodore W. II

    2013-01-01

    An algorithm has been developed to take advantage of the graphics processing hardware in modern computers to efficiently compute high-fidelity solar pressure forces and torques on spacecraft, taking into account the possibility of self-shading due to the articulation of spacecraft components such as solar arrays. The process is easily extended to compute other results that depend on three-dimensional attitude analysis, such as solar array power generation or free molecular flow drag. The impact of photons upon a spacecraft introduces small forces and moments. The magnitude and direction of the forces depend on the material properties of the spacecraft components being illuminated. The parts of the components being lit depends on the orientation of the craft with respect to the Sun, as well as the gimbal angles for any significant moving external parts (solar arrays, typically). Some components may shield others from the Sun. The purpose of this innovation is to enable high-fidelity computation of solar pressure and power generation effects of illuminated portions of spacecraft, taking self-shading from spacecraft attitude and movable components into account. The key idea in this innovation is to compute results dependent upon complicated geometry by using an image to break the problem into thousands or millions of sub-problems with simple geometry, and then the results from the simpler problems are combined to give high-fidelity results for the full geometry. This process is performed by constructing a 3D model of a spacecraft using an appropriate computer language (OpenGL), and running that model on a modern computer's 3D accelerated video processor. This quickly and accurately generates a view of the model (as shown on a computer screen) that takes rotation and articulation of spacecraft components into account. When this view is interpreted as the spacecraft as seen by the Sun, then only the portions of the craft visible in the view are illuminated. The view as

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

    International Nuclear Information System (INIS)

    Marc, Olivier; Praene, Jean-Philippe; Bastide, Alain; Lucas, Franck

    2011-01-01

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

  16. Solar Flash Sub-Millimeter Wave Range Spectrum Part Radiation Modeling

    Directory of Open Access Journals (Sweden)

    V. Yu. Shustikov

    2015-01-01

    Full Text Available Currently, solar flares are under observation on the RT-7.5 radio telescope of BMSTU. This telescope operates in a little-studied range of the spectrum, at wavelengths of 3.2 and 2.2 mm (93 and 140 GHz, thereby providing unique information about parameters of the chromosphere plasma and zone of the temperature minimum. Observations on various instruments provided relatively small amount of data on the radio emission flare at frequencies close to 93 GHz, and at frequency of 140 GHz such observations were not carried out. For these reasons, data collected from the RT-7.5 radio telescope are of high value (Shustikov et al., 2012.This work describes modeling and gives interpretation of the reason for raising flux density spectrum of sub-millimeter radio frequency emission using as an example the GOES flare of class M 5.3 occurred on 04.07.2012 in the active region 11515. This flare was observed on the RT-7.5 radio telescope of BMSTU and was described by Shustikov et al. (2012 and by Smirnova et al. (2013, where it has been suggested that the reason for raising radio frequency emission is a bremsstrahlung of the thermal electrons in the hot plasma of the solar chromosphere. Rough estimates of the plasma temperature at the flare source were obtained.This paper proposes model calculations of the flux density spectrum of the sub-millimeter radio emission based on the gyrosynchrotron Fleischman-Kuznetsov code (Fleishman & Kuznetsov, 2010. Section 1 briefly describes observational data, tools and processing methods used in the work. Section 2 shows results of modeling the flare radio emission. Section 3 discusses results and conclusions.Numerical modeling the sub-millimeter part of the spectrum of the radio flux density for the GOES flare of class M5.3 has been carried out. This flare occurred in the active region 11515 on 04.07.2012. Modeling was based on the observations on the BMSTU’s RT-7.5 radio telescope.The paper draws conclusion based on the

  17. Development of Inorganic Solar Cells by Nanotechnology

    Institute of Scientific and Technical Information of China (English)

    Yafei Zhang; Huijuan Geng; Zhihua Zhou; Jiang Wu; Zhiming Wang; Yaozhong Zhang; Zhongli Li; Liying Zhang; Zhi Yang; Huey Liang Hwang

    2012-01-01

    Inorganic solar cells, as durable photovoltaic devices for harvesting electric energy from sun light,have received tremendous attention due to the fear of exhausting the earth’s energy resources and damaging the living environment due to greenhouse gases. Some recent developments in nanotechnology have opened up new avenues for more relevant inorganic solar cells produced by new photovoltaic conversion concepts and effective solar energy harvesting nanostructures. In this review, the multiple exciton generation effect solar cells, hot carrier solar cells, one dimensional material constructed asymmetrical schottky barrier arrays, noble nanoparticle induced plasmonic enhancement, and light trapping nanostructured semiconductor solar cells are highlighted.

  18. Mathematical modelling and simulation of the thermal performance of a solar heated indoor swimming pool

    Directory of Open Access Journals (Sweden)

    Mančić Marko V.

    2014-01-01

    Full Text Available Buildings with indoor swimming pools have a large energy footprint. The source of major energy loss is the swimming pool hall where air humidity is increased by evaporation from the pool water surface. This increases energy consumption for heating and ventilation of the pool hall, fresh water supply loss and heat demand for pool water heating. In this paper, a mathematical model of the swimming pool was made to assess energy demands of an indoor swimming pool building. The mathematical model of the swimming pool is used with the created multi-zone building model in TRNSYS software to determine pool hall energy demand and pool losses. Energy loss for pool water and pool hall heating and ventilation are analyzed for different target pool water and air temperatures. The simulation showed that pool water heating accounts for around 22%, whereas heating and ventilation of the pool hall for around 60% of the total pool hall heat demand. With a change of preset controller air and water temperatures in simulations, evaporation loss was in the range 46-54% of the total pool losses. A solar thermal sanitary hot water system was modelled and simulated to analyze it's potential for energy savings of the presented demand side model. The simulation showed that up to 87% of water heating demands could be met by the solar thermal system, while avoiding stagnation. [Projekat Ministarstva nauke Republike Srbije, br. III 42006: Research and development of energy and environmentally highly effective polygeneration systems based on using renewable energy sources

  19. Solar Hot Water Heating by Natural Convection.

    Science.gov (United States)

    Noble, Richard D.

    1983-01-01

    Presents an undergraduate laboratory experiment in which a solar collector is used to heat water for domestic use. The working fluid is moved by natural convection so no pumps are required. Experimental apparatus is simple in design and operation so that data can be collected quickly and easily. (Author/JN)

  20. Elementary Students' Mental Models of the Solar System

    Science.gov (United States)

    Calderon-Canales, Elena; Flores-Camacho, Fernando; Gallegos-Cazares, Leticia

    2013-01-01

    This research project aimed to identify and analyze Mexican primary school students' ideas about the components of the solar system. In particular, this study focused on conceptions of the solar system and representations of the dynamics of the solar system based on the functional and structural models that students make in school. Using a…

  1. Probability model for worst case solar proton event fluences

    International Nuclear Information System (INIS)

    Xapsos, M.A.; Summers, G.P.; Barth, J.L.; Stassinopoulos, E.G.; Burke, E.A.

    1999-01-01

    The effects that solar proton events have on microelectronics and solar arrays are important considerations for spacecraft in geostationary orbits, polar orbits and on interplanetary missions. A predictive model of worst case solar proton event fluences is presented. It allows the expected worst case event fluence to be calculated for a given confidence level and for periods of time corresponding to space missions. The proton energy range is from >1 to >300 MeV, so that the model is useful for a variety of radiation effects applications. For each proton energy threshold, the maximum entropy principle is used to select the initial distribution of solar proton event fluences. This turns out to be a truncated power law, i.e., a power law for smaller event fluences that smoothly approaches zero at a maximum fluence. The strong agreement of the distribution with satellite data for the last three solar cycles indicates this description captures the essential features of a solar proton event fluence distribution. Extreme value theory is then applied to the initial distribution of events to obtain the model of worst case fluences

  2. Long-term energy storage tanks for dwellings and solar house architecture. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1980-12-01

    The design and installation of hot water storage tanks as accumulators of solar energy is presented. Solar house architecture which maximizes roof, solar collector energy absorption potential is then considered. Proposals for residential areas which include solar houses are made.

  3. Hot Gas Halos in Galaxies

    Science.gov (United States)

    Mulchaey, John

    Most galaxy formation models predict that massive low-redshift disk galaxies are embedded in extended hot halos of externally accreted gas. Such gas appears necessary to maintain ongoing star formation in isolated spirals like the Milky Way. To explain the large population of red galaxies in rich groups and clusters, most galaxy evolution models assume that these hot gas halos are stripped completely when a galaxy enters a denser environment. This simple model has been remarkably successful at reproducing many observed properties of galaxies. Although theoretical arguments suggest hot gas halos are an important component in galaxies, we know very little about this gas from an observational standpoint. In fact, previous observations have failed to detect soft X-ray emission from such halos in disk galaxies. Furthermore, the assumption that hot gas halos are stripped completely when a galaxy enters a group or cluster has not been verified. We propose to combine proprietary and archival XMM-Newton observations of galaxies in the field, groups and clusters to study how hot gas halos are impacted by environment. Our proposed program has three components: 1) The deepest search to date for a hot gas halo in a quiescent spiral galaxy. A detection will confirm a basic tenet of disk galaxy formation models, whereas a non-detection will seriously challenge these models and impose new constraints on the growth mode and feedback history of disk galaxies. 2) A detailed study of the hot gas halos properties of field early-type galaxies. As environmental processes such as stripping are not expected to be important in the field, a study of hot gas halos in this environment will allow us to better understand how feedback and other internal processes impact hot gas halos. 3) A study of hot gas halos in the outskirts of groups and clusters. By comparing observations with our suite of simulations we can begin to understand what role the stripping of hot gas halos plays in galaxy

  4. Modeling of Possible Conditions for Origin of First Organic Forms in hot Mineral Water

    OpenAIRE

    Ignat Ignatov; Oleg Mosin

    2014-01-01

    The composition of water, its temperature and pH value was analyzed in experiments with modelling of primary hydrosphere and possible conditions for origin of first organic forms in hot mineral water. For this aim the authors performed experiments with hot mineral and seawater from Bulgaria by IR-spectrometry (DNES-method). As model systems were used cactus juice of Echinopsis pachanoi and Mediterranean jellyfish Cotylorhiza tuberculata. It was considered the reactions of condensation and deh...

  5. Heat Transfer Model for Hot Air Balloons

    OpenAIRE

    Lladó Gambín, Adriana

    2016-01-01

    A heat transfer model and analysis for hot air balloons is presented in this work, backed with a flow simulation using SolidWorks. The objective is to understand the major heat losses in the balloon and to identify the parameters that affect most its flight performance. Results show that more than 70% of the heat losses are due to the emitted radiation from the balloon envelope and that convection losses represent around 20% of the total. A simulated heating source is also included in the mod...

  6. Prediction of hourly solar radiation with multi-model framework

    International Nuclear Information System (INIS)

    Wu, Ji; Chan, Chee Keong

    2013-01-01

    Highlights: • A novel approach to predict solar radiation through the use of clustering paradigms. • Development of prediction models based on the intrinsic pattern observed in each cluster. • Prediction based on proper clustering and selection of model on current time provides better results than other methods. • Experiments were conducted on actual solar radiation data obtained from a weather station in Singapore. - Abstract: In this paper, a novel multi-model prediction framework for prediction of solar radiation is proposed. The framework started with the assumption that there are several patterns embedded in the solar radiation series. To extract the underlying pattern, the solar radiation series is first segmented into smaller subsequences, and the subsequences are further grouped into different clusters. For each cluster, an appropriate prediction model is trained. Hence a procedure for pattern identification is developed to identify the proper pattern that fits the current period. Based on this pattern, the corresponding prediction model is applied to obtain the prediction value. The prediction result of the proposed framework is then compared to other techniques. It is shown that the proposed framework provides superior performance as compared to others

  7. Forecast Method of Solar Irradiance with Just-In-Time Modeling

    Science.gov (United States)

    Suzuki, Takanobu; Goto, Yusuke; Terazono, Takahiro; Wakao, Shinji; Oozeki, Takashi

    PV power output mainly depends on the solar irradiance which is affected by various meteorological factors. So, it is required to predict solar irradiance in the future for the efficient operation of PV systems. In this paper, we develop a novel approach for solar irradiance forecast, in which we introduce to combine the black-box model (JIT Modeling) with the physical model (GPV data). We investigate the predictive accuracy of solar irradiance over wide controlled-area of each electric power company by utilizing the measured data on the 44 observation points throughout Japan offered by JMA and the 64 points around Kanto by NEDO. Finally, we propose the application forecast method of solar irradiance to the point which is difficulty in compiling the database. And we consider the influence of different GPV default time on solar irradiance prediction.

  8. Thermal performance analysis of a direct-expansion solar-assisted heat pump water heater

    International Nuclear Information System (INIS)

    Kong, X.Q.; Zhang, D.; Li, Y.; Yang, Q.M.

    2011-01-01

    A direct-expansion solar-assisted heat pump water heater (DX-SAHPWH) is described, which can supply hot water for domestic use during the whole year. The system mainly employs a bare flat-plate collector/evaporator with a surface area of 4.2 m 2 , an electrical rotary-type hermetic compressor, a hot water tank with the volume of 150 L and a thermostatic expansion valve. R-22 is used as working fluid in the system. A simulation model based on lumped and distributed parameter approach is developed to predict the thermal performance of the system. Given the structure parameters, meteorological parameters, time step and final water temperature, the numerical model can output operational parameters, such as heat capacity, system COP and collector efficiency. Comparisons between the simulation results and the experimental measurements show that the model is able to give satisfactory predictions. The effect of various parameters, including solar radiation, ambient temperature, wind speed and compressor speed, has been analyzed on the thermal performance of the system. -- Highlights: ► A direct-expansion solar-assisted heat pump water heater (DX-SAHPWH) is described. ► A simulation model based on lumped and distributed parameter approach is developed to predict the thermal performance of the system. ► The numerical model can output operational parameters, such as heat capacity, system COP and collector efficiency. ► Comparisons between the simulation results and the experimental measurements show that the model is able to give satisfactory predictions. ► The effect of various parameters has been analyzed on the thermal performance of the system.

  9. Performance test for a solar water heater

    Science.gov (United States)

    1979-01-01

    Two reports describe procedures and results of performance tests on domestic solar powered hot water system. Performance tests determine amount of energy collected by system, amount of energy delivered to solar source, power required to operate system and maintain proper tank temperature, overall system efficiency, and temperature distribution in tank.

  10. Prediction of Proper Temperatures for the Hot Stamping Process Based on the Kinetics Models

    Science.gov (United States)

    Samadian, P.; Parsa, M. H.; Mirzadeh, H.

    2015-02-01

    Nowadays, the application of kinetics models for predicting microstructures of steels subjected to thermo-mechanical treatments has increased to minimize direct experimentation, which is costly and time consuming. In the current work, the final microstructures of AISI 4140 steel sheets after the hot stamping process were predicted using the Kirkaldy and Li kinetics models combined with new thermodynamically based models in order for the determination of the appropriate process temperatures. In this way, the effect of deformation during hot stamping on the Ae3, Acm, and Ae1 temperatures was considered, and then the equilibrium volume fractions of phases at different temperatures were calculated. Moreover, the ferrite transformation rate equations of the Kirkaldy and Li models were modified by a term proposed by Åkerström to consider the influence of plastic deformation. Results showed that the modified Kirkaldy model is satisfactory for the determination of appropriate austenitization temperatures for the hot stamping process of AISI 4140 steel sheets because of agreeable microstructure predictions in comparison with the experimental observations.

  11. Solar energy conversion

    CERN Document Server

    Likhtenshtein, Gertz I

    2012-01-01

    Finally filling a gap in the literature for a text that also adopts the chemist?s view of this hot topic, Prof Likhtenshtein, an experienced author and internationally renowned scientist, considers different physical and engineering aspects in solar energy conversion. From theory to real-life systems, he shows exactly which chemical reactions take place when converting light energy, providing an overview of the chemical perspective from fundamentals to molecular harvesting systems and solar cells. This essential guide will thus help researchers in academia and industry better understa

  12. FARIMA MODELING OF SOLAR FLARE ACTIVITY FROM EMPIRICAL TIME SERIES OF SOFT X-RAY SOLAR EMISSION

    International Nuclear Information System (INIS)

    Stanislavsky, A. A.; Burnecki, K.; Magdziarz, M.; Weron, A.; Weron, K.

    2009-01-01

    A time series of soft X-ray emission observed by the Geostationary Operational Environment Satellites from 1974 to 2007 is analyzed. We show that in the solar-maximum periods the energy distribution of soft X-ray solar flares for C, M, and X classes is well described by a fractional autoregressive integrated moving average model with Pareto noise. The model incorporates two effects detected in our empirical studies. One effect is a long-term dependence (long-term memory), and another corresponds to heavy-tailed distributions. The parameters of the model: self-similarity exponent H, tail index α, and memory parameter d are statistically stable enough during the periods 1977-1981, 1988-1992, 1999-2003. However, when the solar activity tends to minimum, the parameters vary. We discuss the possible causes of this evolution and suggest a statistically justified model for predicting the solar flare activity.

  13. How Hot Precursor Modify Island Nucleation: A Rate-Equation Model

    Science.gov (United States)

    Morales-Cifuentes, Josue; Einstein, T. L.; Pimpinelli, Alberto

    2015-03-01

    We describe the analysis, based on rate equations, of the hot precursor model mentioned in the previous talk. Two key parameters are the competing times of ballistic monomers decaying into thermalized monomers vs. being captured by an island, which naturally define a ``thermalization'' scale for the system. We interpret the energies and dimmensionless parameters used in the model, and provide both an implicit analytic solution and a convenient asymptotic approximation. Further analysis reveals novel scaling regimes and nonmonotonic crossovers between them. To test our model, we applied it to experiments on parahexaphenyl (6P) on sputtered mica. With the resulting parameters, the curves derived from our analytic treatment account very well for the data at the 4 different temperatures. The fit shows that the high-flux regime corresponds not to ALA (attachment-limited aggregation) or HMA (hot monomer aggregation) but rather to an intermediate scaling regime related to DLA (diffusion-limited aggregation). We hope this work stimulates further experimental investigations. Work at UMD supported by NSF CHE 13-05892.

  14. Alternative for Summer Use of Solar Air Heaters in Existing Buildings

    Directory of Open Access Journals (Sweden)

    Sergio L. González-González

    2017-07-01

    Full Text Available Among solar thermal technologies for indoor heating, solar air heaters (SAH are appealing for implementation on existing buildings due to their simplicity, fewer risks related to the working fluid, and possible independence from the building structure. However, existing research work mainly focuses on winter use and still fails in providing effective solutions for yearly operation, which would enhance their interest. With the aim of analysing an alternative summer use, this work firstly characterises a double channel-single pass solar air collector through experimentation. From the obtained results, modelling and simulation tasks have been conducted to evaluate the possibilities of using hot air, provided by the SAH, while operating under summer conditions within a closed loop, to feed an air-to-water heat exchanger for domestic hot water (DHW production. The system is studied through simulation under two different configurations for a case study in Valladolid (Spain, during the period from May to September for different airflows in the closed loop. Results show that daily savings can vary from 27% to 85% among the different operating conditions; a configuration where make-up water is fed to the heat exchanger being preferable, with a dedicated water tank for the solar heated water storage of the minimum possible volume. The more favourable results for the harshest months highlight the interest of extending the use of the solar air heaters to the summer period.

  15. Solar buildings program contract summary, calendar year 1999

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-06-07

    The mission of the US Department of Energy's Solar Buildings Program is to advance the development and widespread deployment of competitive solar thermal technologies for use in buildings. The long-term goal of the Program is to combine solar energy technologies with energy-efficient construction techniques and create cost-effective buildings that have a zero net need for fossil fuel energy on an annual basis. The Solar Buildings Program conducts research and development on solar technologies that can deliver heat, light, and hot water to residential and commercial buildings. By working closely with manufacturers in both the buildings and solar energy industries and by supporting research at universities and national laboratories, the Solar Buildings Program brings together the diverse players developing reliable and affordable solar technologies for building applications. The National Renewable Energy Laboratory (NREL) in Golden, Colorado, and Sandia National Laboratories (SNL) in Albuquerque, New Mexico, jointly participate in the Solar Buildings Program. These two national laboratories work closely with industry researching new concepts, developing technology improvements, reducing manufacturing costs, monitoring system performance, promoting quality assurance, and identifying potential new markets. In calendar year 1999, the Solar Buildings Program focused primarily on solar hot water system research and development (R and D), US industry manufacturing assistance, and US market assistance. The Program also completed a number of other projects that were begun in earlier years. This Contract Summary describes the Program's contracted activities that were active during 1999.

  16. Hot spots and heavily dislocated regions in multicrystalling silicon cells

    International Nuclear Information System (INIS)

    Simo, A.; Martinuzzi, S.

    1990-01-01

    The formation mechanism and the electrical consequences of hot spots have been investigated in multicrystalline solar cells. The hot spots were revealed by means of an infrared camera when the cells are reverse biassed in the dark. The minority carrier diffusion length (L n ), the photovoltage (V oc ) and the photocurrent (J sc ) were measured in the hot spot area and far from this zone thanks to mesa diodes. Dark forward I-V curves lead to values of ideality factor (M) and reverse saturation current (J o ). It is found that J o and M are higher in the hot spot area, while J sc , V oc and at a less extent L n are smaller. Large densities of dislocations and lineages structures are revealed in the abnormally heated regions

  17. Synoptic, Global Mhd Model For The Solar Corona

    Science.gov (United States)

    Cohen, Ofer; Sokolov, I. V.; Roussev, I. I.; Gombosi, T. I.

    2007-05-01

    The common techniques for mimic the solar corona heating and the solar wind acceleration in global MHD models are as follow. 1) Additional terms in the momentum and energy equations derived from the WKB approximation for the Alfv’en wave turbulence; 2) some empirical heat source in the energy equation; 3) a non-uniform distribution of the polytropic index, γ, used in the energy equation. In our model, we choose the latter approach. However, in order to get a more realistic distribution of γ, we use the empirical Wang-Sheeley-Arge (WSA) model to constrain the MHD solution. The WSA model provides the distribution of the asymptotic solar wind speed from the potential field approximation; therefore it also provides the distribution of the kinetic energy. Assuming that far from the Sun the total energy is dominated by the energy of the bulk motion and assuming the conservation of the Bernoulli integral, we can trace the total energy along a magnetic field line to the solar surface. On the surface the gravity is known and the kinetic energy is negligible. Therefore, we can get the surface distribution of γ as a function of the final speed originating from this point. By interpolation γ to spherically uniform value on the source surface, we use this spatial distribution of γ in the energy equation to obtain a self-consistent, steady state MHD solution for the solar corona. We present the model result for different Carrington Rotations.

  18. Investigation on Solar Heating System with Building-Integrated Heat Storage

    DEFF Research Database (Denmark)

    Heller, Alfred

    1996-01-01

    Traditional solar heating systems cover between 5 and 10% of the heat demand fordomestic hot water and comfort heating. By applying storage capacity this share can beincreased much. The Danish producer of solar heating systems, Aidt-Miljø, markets such a system including storage of dry sand heated...... by PP-pipe heat exchanger. Heat demand is reduced due to direct solar heating and due to storage. The storage affects the heat demand passively due to higher temperatures. Hence heat loss is reduced and passive heating is optioned. In theory, by running the system flow backwards, active heating can...... solar collector area of the system, was achieved. Active heating from the sand storage was not observed. The pay-back time for the system can be estimated to be similar to solar heated domestic hot water systems in general. A number of minor improvements on the system could be pointed out....

  19. Instrumentation at the Decade 80 solar house in Tucson, Arizona

    Science.gov (United States)

    1978-01-01

    Modifications, problems and solutions for the instrumentation system that occurred during the period from May through September, 1978, are described. The solar house was built to show the use of copper in home building and to demonstrate the use of solar energy to provide space heating and cooling and domestic hot water. The auxiliary energy sources are electrical resistance heating for the domestic hot water and a gas-fired boiler for space heating and operation of the adsorption air conditioning units.

  20. Solar Space and Water Heating for Hospital --Charlottesville, Virginia

    Science.gov (United States)

    1982-01-01

    Solar heating system described in an 86-page report consists of 88 single-glazed selectively-coated baseplate collector modules, hot-water coils in air ducts, domestic-hot-water preheat tank, 3,000 Gallon (11,350-1) concrete urethane-insulated storage tank and other components.

  1. Double plasma resonance instability as a source of solar zebra emission

    Science.gov (United States)

    Benáček, J.; Karlický, M.

    2018-03-01

    Context. The double plasma resonance (DPR) instability plays a basic role in the generation of solar radio zebras. In the plasma, consisting of the loss-cone type distribution of hot electrons and much denser and colder background plasma, this instability generates the upper-hybrid waves, which are then transformed into the electromagnetic waves and observed as radio zebras. Aims: In the present paper we numerically study the double plasma resonance instability from the point of view of the zebra interpretation. Methods: We use a 3-dimensional electromagnetic particle-in-cell (3D PIC) relativistic model. We use this model in two versions: (a) a spatially extended "multi-mode" model and (b) a spatially limited "specific-mode" model. While the multi-mode model is used for detailed computations and verifications of the results obtained by the "specific-mode" model, the specific-mode model is used for computations in a broad range of model parameters, which considerably save computational time. For an analysis of the computational results, we developed software tools in Python. Results: First using the multi-mode model, we study details of the double plasma resonance instability. We show how the distribution function of hot electrons changes during this instability. Then we show that there is a very good agreement between results obtained by the multi-mode and specific-mode models, which is caused by a dominance of the wave with the maximal growth rate. Therefore, for computations in a broad range of model parameters, we use the specific-mode model. We compute the maximal growth rates of the double plasma resonance instability with a dependence on the ratio between the upper-hybrid ωUH and electron-cyclotron ωce frequency. We vary temperatures of both the hot and background plasma components and study their effects on the resulting growth rates. The results are compared with the analytical ones. We find a very good agreement between numerical and analytical growth

  2. The choice between cooled tubular reactor models: analysis of the hot spot

    NARCIS (Netherlands)

    Westerink, E.J.; Koster, N.; Westerterp, K.R.

    1990-01-01

    The applicability of the one-dimensional pseudo-homogeneous model of the cooled tubular reactor is studied. Using the two-dimensional model as the more accurate one we compared both models by studying the influence of the design and operating variables on the conditions in the hot spot of the

  3. Solar water heaters in Taiwan

    International Nuclear Information System (INIS)

    Chang, K.; Lee, T.; Chung, K.

    2006-01-01

    Solar water heater has been commercialized during the last two decades in Taiwan. The government initiated the incentive programs during 1986-1991 and 2000-2004. This created an economic incentive for the end-users. The total area of solar collectors installed was more than one million square meters. The data also show that most of the solar water heaters are mainly used by the domestic sector for hot water production (about 97%). The regional popularization analysis indicates limited installation of solar water heaters in the northern district. In the eastern district and remote islands, the problems of climatic conditions and availability of localized installers/dealers are addressed. (author)

  4. Effect of insolation forecasting error on reduction of electricity charges for solar hot water system; Taiyonetsu kyuto system no denki ryokin sakugen koka ni oyobosu nissharyo yosoku gosa no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, S [Maizuru National College of Technology, Kyoto (Japan); Kenmoku, Y; Sakakibara, T [Toyohashi University of Technology, Aichi (Japan); Kawamoto, T [Shizuoka University, Shizuoka (Japan)

    1996-10-27

    A solar hot water system can be economically operated if inexpensive midnight power is purchased to cover the shortage of solar energy predicted for the following day. Investigations were conducted because error in insolation prediction affects the system operation and electric charge reduction effect. The target temperature of the heat accumulation tank at every predetermined time point is calculated on the previous evening in consideration of predicted insolation so that the water will be as hot as prescribed at the feeding time on the following day. Midnight power is used for uniform heating to attain the target temperature for 7 o`clock on the following morning. The uniform heating continues from 8 o`clock to the feeding time, this time using solar energy and daytime power to attain the target temperature. Accordingly, the division between the midnight power and daytime power is determined in view of the target temperature for 7 o`clock on the following morning, which target temperature is so set that the charge will be the minimum by optimizing the allocation of the above-said two. When the insolation prediction error rate is beyond 30%, the electric charge grows higher as the rate rises. But, when the rate is not higher than 30%, the charge is little affected by a rise in the rate. 5 refs., 10 figs., 1 tab.

  5. Solar energy system performance evaluation. Seasonal report for Wormser, Columbia, South Carolina

    Science.gov (United States)

    1980-01-01

    The Wormser Solar Energy System's operational performance from April 1979 through March 1980 was evaluated. The space heating subsystem met 42 percent of the measured space heating load and the hot water subsystem met 23 percent of the measured hot water demand. Net electrical energy savings were 4.36 million Btu's or 1277 kwh. Fossil energy savings will increase considerably if the uncontrolled solar energy input to the building is considered.

  6. Modelling of diffuse solar fraction with multiple predictors

    Energy Technology Data Exchange (ETDEWEB)

    Ridley, Barbara; Boland, John [Centre for Industrial and Applied Mathematics, University of South Australia, Mawson Lakes Boulevard, Mawson Lakes, SA 5095 (Australia); Lauret, Philippe [Laboratoire de Physique du Batiment et des Systemes, University of La Reunion, Reunion (France)

    2010-02-15

    For some locations both global and diffuse solar radiation are measured. However, for many locations, only global radiation is measured, or inferred from satellite data. For modelling solar energy applications, the amount of radiation on a tilted surface is needed. Since only the direct component on a tilted surface can be calculated from direct on some other plane using trigonometry, we need to have diffuse radiation on the horizontal plane available. There are regression relationships for estimating the diffuse on a tilted surface from diffuse on the horizontal. Models for estimating the diffuse on the horizontal from horizontal global that have been developed in Europe or North America have proved to be inadequate for Australia. Boland et al. developed a validated model for Australian conditions. Boland et al. detailed our recent advances in developing the theoretical framework for the use of the logistic function instead of piecewise linear or simple nonlinear functions and was the first step in identifying the means for developing a generic model for estimating diffuse from global and other predictors. We have developed a multiple predictor model, which is much simpler than previous models, and uses hourly clearness index, daily clearness index, solar altitude, apparent solar time and a measure of persistence of global radiation level as predictors. This model performs marginally better than currently used models for locations in the Northern Hemisphere and substantially better for Southern Hemisphere locations. We suggest it can be used as a universal model. (author)

  7. Solar-wind predictions for the Parker Solar Probe orbit. Near-Sun extrapolations derived from an empirical solar-wind model based on Helios and OMNI observations

    Science.gov (United States)

    Venzmer, M. S.; Bothmer, V.

    2018-03-01

    Context. The Parker Solar Probe (PSP; formerly Solar Probe Plus) mission will be humanitys first in situ exploration of the solar corona with closest perihelia at 9.86 solar radii (R⊙) distance to the Sun. It will help answer hitherto unresolved questions on the heating of the solar corona and the source and acceleration of the solar wind and solar energetic particles. The scope of this study is to model the solar-wind environment for PSPs unprecedented distances in its prime mission phase during the years 2018 to 2025. The study is performed within the Coronagraphic German And US SolarProbePlus Survey (CGAUSS) which is the German contribution to the PSP mission as part of the Wide-field Imager for Solar PRobe. Aim. We present an empirical solar-wind model for the inner heliosphere which is derived from OMNI and Helios data. The German-US space probes Helios 1 and Helios 2 flew in the 1970s and observed solar wind in the ecliptic within heliocentric distances of 0.29 au to 0.98 au. The OMNI database consists of multi-spacecraft intercalibrated in situ data obtained near 1 au over more than five solar cycles. The international sunspot number (SSN) and its predictions are used to derive dependencies of the major solar-wind parameters on solar activity and to forecast their properties for the PSP mission. Methods: The frequency distributions for the solar-wind key parameters, magnetic field strength, proton velocity, density, and temperature, are represented by lognormal functions. In addition, we consider the velocity distributions bi-componental shape, consisting of a slower and a faster part. Functional relations to solar activity are compiled with use of the OMNI data by correlating and fitting the frequency distributions with the SSN. Further, based on the combined data set from both Helios probes, the parameters frequency distributions are fitted with respect to solar distance to obtain power law dependencies. Thus an empirical solar-wind model for the inner

  8. Revising the Local Bubble Model due to Solar Wind Charge Exchange X-ray Emission

    Science.gov (United States)

    Shelton, Robin L.

    2009-03-01

    The hot Local Bubble surrounding the solar neighborhood has been primarily studied through observations of its soft X-ray emission. The measurements were obtained by attributing all of the observed local soft X-rays to the bubble. However, mounting evidence shows that the heliosphere also produces diffuse X-rays. The source is solar wind ions that have received an electron from another atom. The presence of this alternate explanation for locally produced diffuse X-rays calls into question the existence and character of the Local Bubble. This article addresses these questions. It reviews the literature on solar wind charge exchange (SWCX) X-ray production, finding that SWCX accounts for roughly half of the observed local 1/4 keV X-rays found at low latitudes. This article also makes predictions for the heliospheric O VI column density and intensity, finding them to be smaller than the observational error bars. Evidence for the continued belief that the Local Bubble contains hot gas includes the remaining local 1/4 keV intensity, the observed local O VI column density, and the need to fill the local region with some sort of plasma. If the true Local Bubble is half as bright as previously thought, then its electron density and thermal pressure are 1/sqrt{2} as great as previously thought, and its energy requirements and emission measure are 1/2 as great as previously thought. These adjustments can be accommodated easily, and, in fact, bring the Local Bubble’s pressure more in line with that of the adjacent material. Suggestions for future work are made.

  9. Interplanetary Radiation and Internal Charging Environment Models for Solar Sails

    Science.gov (United States)

    Minow, Joseph I.; Altstatt, Richard L.; NeegaardParker, Linda

    2005-01-01

    A Solar Sail Radiation Environment (SSRE) model has been developed for defining charged particle environments over an energy range from 0.01 keV to 1 MeV for hydrogen ions, helium ions, and electrons. The SSRE model provides the free field charged particle environment required for characterizing energy deposition per unit mass, charge deposition, and dose rate dependent conductivity processes required to evaluate radiation dose and internal (bulk) charging processes in the solar sail membrane in interplanetary space. Solar wind and energetic particle measurements from instruments aboard the Ulysses spacecraft in a solar, near-polar orbit provide the particle data over a range of heliospheric latitudes used to derive the environment that can be used for radiation and charging environments for both high inclination 0.5 AU Solar Polar Imager mission and the 1.0 AU L1 solar missions. This paper describes the techniques used to model comprehensive electron, proton, and helium spectra over the range of particle energies of significance to energy and charge deposition in thin (less than 25 micrometers) solar sail materials.

  10. Modelling solar cells with thermal phenomena taken into account

    International Nuclear Information System (INIS)

    Górecki, K; Górecki, P; Paduch, K

    2014-01-01

    The paper is devoted to modelling properties of solar cells. The authors' electrothermal model of such cells is described. This model takes into account the influence of temperature on its characteristics. Some results of calculations and measurements of selected solar cells are presented and discussed. The good agreement between the results of calculations and measurements was obtained, which proves the correctness of the elaborated model.

  11. Simulation study on single family house with solar floor and domestic hot water heating system by EESLISM; EESLISM ni yoru taiyonetsu danbo kyuto jutaku no simulation

    Energy Technology Data Exchange (ETDEWEB)

    Roh, H; Udagawa, M [Kogakuin University, Tokyo (Japan)

    1997-11-25

    Indoor thermal conditions and energy performance were simulated, by the aid of EESLISM as a common simulation program for indoor thermal conditions and energy systems, for an actual two-storied single family house equipped with solar-heated floors and a domestic hot water (DHW) heating system, in order to investigate applicability of the simulation program. The house, built in Shibuya Ward in Tokyo, has a total floor area of 164m{sup 2}, with a living room, dining room and study heated by the solar system for a total floor area of 35m{sup 2}. A heat-storage tank is provided, dedicated to the DHW system. The solar collector is of flat type, with selectively light-absorbing planes, having a total collector area of 11.46m{sup 2}. The operating conditions of the floor-heating and DHW systems are almost reproduced. It is necessary to take surrounding conditions into consideration; solar radiation in daytime will be overestimated if adjacent buildings are neglected to give higher temperature in the space and on the wall on the south than the observed level. 6 refs., 5 figs., 1 tab.

  12. Comparison of solar panel models for grid integration studies

    NARCIS (Netherlands)

    Brito, E.M.S.; Cupertino, A.F.; Carlette, L.P; Filho, D.O.; Oliveira, D.; Pereira, H.A; Ribeiro, P.F.

    2012-01-01

    Photovoltaic systems are highly dependent on climatic conditions in which they are submitted. The incident solar irradiance and temperature are the main factors impacting on the power generated by a solar panel. This paper presents three different models of a solar panel and compare, through

  13. Bridging the Radiative Transfer Models for Meteorology and Solar Energy Applications

    Science.gov (United States)

    Xie, Y.; Sengupta, M.

    2017-12-01

    Radiative transfer models are used to compute solar radiation reaching the earth surface and play an important role in both meteorology and solar energy studies. Therefore, they are designed to meet the needs of specialized applications. For instance, radiative transfer models for meteorology seek to provide more accurate cloudy-sky radiation compared to models used in solar energy that are geared towards accuracy in clear-sky conditions associated with the maximum solar resource. However, models for solar energy applications are often computationally faster, as the complex solution of the radiative transfer equation is parameterized by atmospheric properties that can be acquired from surface- or satellite-based observations. This study introduces the National Renewable Energy Laboratory's (NREL's) recent efforts to combine the advantages of radiative transfer models designed for meteorology and solar energy applictions. A fast all-sky radiation model, FARMS-NIT, was developed to efficiently compute narrowband all-sky irradiances over inclined photovoltaic (PV) panels. This new model utilizes the optical preperties from a solar energy model, SMARTS, to computes surface radiation by considering all possible paths of photon transmission and the relevent scattering and absorption attenuation. For cloudy-sky conditions, cloud bidirectional transmittance functions (BTDFs) are provided by a precomputed lookup table (LUT) by LibRadtran. Our initial results indicate that FARMS-NIT has an accuracy that is similar to LibRadtran, a highly accurate multi-stream model, but is significantly more efficient. The development and validation of this model will be presented.

  14. A Raster Based Approach To Solar Pressure Modeling

    Science.gov (United States)

    Wright, Theodore

    2014-01-01

    The impact of photons upon a spacecraft introduces small forces and moments. The magnitude and direction of the forces depend on the material properties of the spacecraft components being illuminated. Which components are being lit depends on the orientation of the craft with respect to the Sun as well as the gimbal angles for any significant moving external parts (solar arrays, typically). Some components may shield others from the Sun.To determine solar pressure in the presence overlapping components, a 3D model can be used to determine which components are illuminated. A view (image) of the model as seen from the Sun shows the only contributors to solar pressure. This image can be decomposed into pixels, each of which can be treated as a non-overlapping flat plate as far as solar pressure calculations are concerned. The sums of the pressures and moments on these plates approximate the solar pressure and moments on the entire vehicle.The image rasterization technique can also be used to compute other spacecraft attributes that are dependent on attitude and geometry, including solar array power generation capability and free molecular flow drag.

  15. Investigations of medium sized solar combi systems

    DEFF Research Database (Denmark)

    Andersen, Elsa; Furbo, Simon

    2006-01-01

    A large variety of solar combi systems are on the market, but it is still too early to draw conclusions on optimum design of solar combi systems. Among others, the following questions need to be answered: Is an external domestic hot water preparation more desirable than an internal? What...... is the advantage by using inlet stratifiers? To answer the questions, theoretical investigations are carried out for differently designed solar combi systems. The work is carried out within the Solar Heating and Cooling Programme of the International Energy Agency (IEA SHC), Task 32 Advanced storage concepts...... for solar houses and low energy buildings....

  16. Economical analysis of a solar desalination system

    DEFF Research Database (Denmark)

    Chen, Ziqian; Wang, Tie-Zhu; He, Xiao-Rong

    2012-01-01

    Based on the calculation of the single-factor impact values of the parameters of a triple stage tower-type of solar desalination unit by utilizing a single-factor analyzing method, the influences of the cost of solar heating system, the cost of hot water tank, the costs of desalination unit...... and yearly electrical power, the life time of solar desalination unit and the yearly yield of fresh water, on the cost of the fresh water production of the solar desalination unit are studied. It is helpful to do the further investigation on solar desalination systems for reducing the cost of fresh water...

  17. Distributed Nonstationary Heat Model of Two-Channel Solar Air Heater

    International Nuclear Information System (INIS)

    Klychev, Sh. I.; Bakhramov, S. A.; Ismanzhanov, A. I.; Tashiev, N.N.

    2011-01-01

    An algorithm for a distributed nonstationary heat model of a solar air heater (SAH) with two operating channels is presented. The model makes it possible to determine how the coolant temperature changes with time along the solar air heater channel by considering its main thermal and ambient parameters, as well as variations in efficiency. Examples of calculations are presented. It is shown that the time within which the mean-day efficiency of the solar air heater becomes stable is significantly higher than the time within which the coolant temperature reaches stable values. The model can be used for investigation of the performances of solar water-heating collectors. (authors)

  18. Solar hot water for household and institutional use in Bujumbura, Burundi

    International Nuclear Information System (INIS)

    Katihabwa, J.

    1990-01-01

    This paper reports on solar energy which is clean and renewable. It is the primary source for a wide range of energy resources such as biomass, hydraulics, coal, peat and petroleum. Until recently, the sun was the major source of energy used by man to satisfy his needs. The extraction and use of fossil fuels became important with the technological and industrial development that took place in the nineteenth century. For countries without fossil fuels (such as petroleum and coal), solar energy is an important asset. The oil crisis of 1973 clearly showed the limits of fossil fuel consumption. The crisis slowed down and, in some cases, severely hampered economic growth in many developing countries. To this day, fossil fuels remain expensive for many developing countries which have to part with a significant share of their meagre convertible currency resources to import fossil fuels. It is thus imperative that developing countries should investigate the possibility of developing solar energy systems that can reduce their dependence on fossil fuels. In the short term, high investment costs and shortage of qualified manpower are major constraints on the development of solar energy systems. In the long run, however, the benefits of solar energy systems are expected to overcome these constraints. The benefits include low operation costs and non-generation of pollutants. The decentralized nature of solar energy is an asset in the isolated rural areas of Africa. It is possible to build small solar units and this provide energy security and autonomy at the level of a community and even at the level of an individual. Solar energy has, however, one major disadvantage - its energy density is low (1.0 kw per square metre on the earth surface, after taking absorption losses into account)

  19. The multiwavelength spectrum of NGC 3115: hot accretion flow properties

    Science.gov (United States)

    Almeida, Ivan; Nemmen, Rodrigo; Wong, Ka-Wah; Wu, Qingwen; Irwin, Jimmy A.

    2018-04-01

    NGC 3115 is the nearest galaxy hosting a billion solar mass black hole and is also a low-luminosity active galactic nucleus (LLAGN). X-ray observations of this LLAGN are able to spatially resolve the hot gas within the sphere of gravitational influence of the supermassive black hole. These observations make NGC 3115 an important test bed for black hole accretion theory in galactic nuclei since they constrain the outer boundary conditions of the hot accretion flow. We present a compilation of the multiwavelength spectral energy distribution (SED) of the nucleus of NGC 3115 from radio to X-rays. We report the results from modelling the observed SED with radiatively inefficient accretion flow (RIAF) models. The radio emission can be well-explained by synchrotron emission from the RIAF without the need for contribution from a relativistic jet. We obtain a tight constraint on the RIAF density profile, ρ (r) ∝ r^{-0.73 _{-0.02} ^{+0.01}}, implying that mass-loss through subrelativistic outflows from the RIAF is significant. The lower frequency radio observation requires the synchrotron emission from a non-thermal electron population in the RIAF, similarly to Sgr A*.

  20. Experimental analysis and modeling of the IV characteristics of photovoltaic solar cells under solar spectrum spot illumination

    Energy Technology Data Exchange (ETDEWEB)

    Munji, M.K., E-mail: mathew.munji@nmmu.ac.z [Department of Physics, Nelson Mandela Metropolitan University, PO Box 7700 Port Elizabeth 6031 (South Africa); Dyk, E.E. van; Vorster, F.J. [Department of Physics, Nelson Mandela Metropolitan University, PO Box 7700 Port Elizabeth 6031 (South Africa)

    2009-12-01

    In this paper, some models that have been put forward to explain the characteristics of a photovoltaic solar cell device under solar spot-illumination are investigated. In the experimental procedure, small areas of the cell were selected and illuminated at different solar intensities. The solar cell open circuit voltage (V{sub oc}) and short circuit current (I{sub sc}) obtained at different illumination intensities was used to determine the solar cell ideality factor. By varying the illuminated area on the solar cell, changes in the ideality factor were studied. The ideality factor obtained increases with decreasing illumination surface ratio. The photo-generated current at the illuminated part of the cell is assumed to act as a dc source that injects charge carriers into the p-n junction of the whole solar cell while the dark region of the solar cell operates in a low space charge recombination regime with small diffusion currents. From this analysis, a different model of a spot illuminated cell that uses the variation of ideality factor with the illuminated area is proposed.

  1. Experimental analysis and modeling of the IV characteristics of photovoltaic solar cells under solar spectrum spot illumination

    International Nuclear Information System (INIS)

    Munji, M.K.; Dyk, E.E. van; Vorster, F.J.

    2009-01-01

    In this paper, some models that have been put forward to explain the characteristics of a photovoltaic solar cell device under solar spot-illumination are investigated. In the experimental procedure, small areas of the cell were selected and illuminated at different solar intensities. The solar cell open circuit voltage (V oc ) and short circuit current (I sc ) obtained at different illumination intensities was used to determine the solar cell ideality factor. By varying the illuminated area on the solar cell, changes in the ideality factor were studied. The ideality factor obtained increases with decreasing illumination surface ratio. The photo-generated current at the illuminated part of the cell is assumed to act as a dc source that injects charge carriers into the p-n junction of the whole solar cell while the dark region of the solar cell operates in a low space charge recombination regime with small diffusion currents. From this analysis, a different model of a spot illuminated cell that uses the variation of ideality factor with the illuminated area is proposed.

  2. Microstructural modelling and lubrication study during zirconium alloy hot extrusion

    International Nuclear Information System (INIS)

    Gaudout, B.

    2009-01-01

    Using torsion tests (with strain rate jumps) and an experimental hot mini-extrusion apparatus, several samples zirconium alloy have been deformed: Zircaloy-4 (high α range) and Zr-1Nb (α + β domain). The fragmentation of the microstructure and post-dynamic grain growth have been examined. The main difference between these two alloys is that Zr-1Nb does not show grain growth during a heat treatment within the α + β domain after hot deformation. The recrystallization volume fraction has been measured on extruded samples with or without heat treatment. These rheological and microstructural data have been used to determine the parameters of a microstructural model including: a work-hardening model (Laaasraoui/Jonas), a continuous dynamic recrystallization model (Gourdet/Montheillet) and a grain growth model. This model leads to a good prediction of recrystallization volume fraction for Zircaloy-4 extrusion. However, the Zr-1Nb model cannot be validated because of the difficulty to observe deformed microstructures. Extrusion process is lubricated with a solid film. Trapping tests show that this lubricant is thermoviscoplastic. Friction along the container and several observations show the lubrication is not realized by a continuous film. Indeed, the heterogeneousness of deformation of these alloys causes a rupture of the lubricant film. Experiments and numerical simulations show that the radial gradient of axial displacement is affected by friction but also by stress softening of the alloys. (author)

  3. Mathematical and computational modeling simulation of solar drying Systems

    Science.gov (United States)

    Mathematical modeling of solar drying systems has the primary aim of predicting the required drying time for a given commodity, dryer type, and environment. Both fundamental (Fickian diffusion) and semi-empirical drying models have been applied to the solar drying of a variety of agricultural commo...

  4. Numerical analysis of the turbulent natural convection in a solar chimney; Analise numerica da conveccao natural turbulenta em uma chamine solar

    Energy Technology Data Exchange (ETDEWEB)

    Brasil, Cristiana S.; Valle, Ramon M.; Cortez, Marcio F.B.; Ferreira, Andre G. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Engenharia Mecanica]. E-mail: tite@demec.ufmg.br; ramon@demec.ufmg.br; fonteboa@demec.ufmg.br; ferreira@demec.ufmg.br

    2000-07-01

    This paper presents a theoretical analysis of the turbulent natural convection in a solar chimney operating in steady flow, with prescribed conditions of temperature in the ground. The solar radiation heats the air under the cover, which flows to the tower without artificial pumping. The hot air produced may be used to dry several agricultural products. The numerical analysis of the natural convection in this kind of dryer has fundamental importance on the design and building of this device. The mathematical model includes the conservation laws for mass, momentum and thermal energy and the transport equations for the turbulence model variables (k and e ). The k- e model of turbulence with wall functions was used. A computational code using the Finite Volume Method in Generalized Coordinates was developed to solve the system of equations that describes thermal and hydro dynamically the flow. The velocity and temperature fields are shown to the flow in the solar chimney. With geometrical alterations on the device, one can obtain a detailed description of the flow, which allow the guideline for a suitable configuration to build an experimental prototype. (author)

  5. Silk cocoon drying in forced convection type solar dryer

    International Nuclear Information System (INIS)

    Singh, Panna Lal

    2011-01-01

    The thin layer silk cocoon drying was studied in a forced convection type solar dryer. The drying chamber was provided with several trays on which the cocoons loaded in thin layer. The hot air generated in the solar air heater was forced into drying chamber to avoid the direct exposure of sunlight and UV radiation on cocoons. The drying air temperature varied from 50 to 75 o C. The cocoon was dried from the initial moisture content of about 60-12% (wb). The drying data was fitted to thin layer drying models. Drying behaviour of the silk cocoon was best fitted with the Wang and Singh drying model. Good agreement was obtained between predicted and experimental values. Quality of the cocoons dried in the solar dryer was at par with the cocoons dried in the conventional electrical oven dryer in term of the silk yield and strength of the silk. Saving of electrical energy was about 0.75 kWh/kg cocoons dried. Economic analysis indicated that the NPV of the solar dryer was higher and more stable (against escalation rate of electricity) as compare to the same for electrical oven dryer. Due to simplicity in design and construction and significant saving of operational electrical energy, solar cocoon dryer seems to be a viable option.

  6. 'Solurban' project - Solar utilisation potential of urban sites

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, D.; Scartezzini, J.-L.; Montavon, M. [Swiss Federal Institute of Technology (EPFL), Laboratoire d' Energie Solaire et de Physique du Batiment (LESO-PB), Lausanne (Switzerland); Compagnon, R. [Ecole d' ingenieurs et d' architectes de Fribourg (EIAF), University of Applied Sciences of Western Switzerland (HES-SO), Fribourg (Switzerland)

    2005-07-01

    This report for the Swiss Federal Office of Energy (SFOE) presents the results of a project that examined three urban locations in Switzerland with respect to their potentials for using solar energy and daylight to reduce energy demands in the lighting, heating and hot-water generation areas. The three urban areas examined included the Matthaeus district in Basle with its older residential apartment buildings, the Bellevaux residential district of Lausanne and the Meyrin district in Geneva - a nineteen-sixties satellite town. The calculation methodology and the three-dimensional digital models used are discussed. The results, including radiation availability and sky-access are discussed. Appropriate active and passive solar technologies are reviewed.

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

    Directory of Open Access Journals (Sweden)

    Lívia Bodonská

    2006-09-01

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

  8. Mathematical Modeling of Dual Intake Transparent Transpired Solar Collector

    Directory of Open Access Journals (Sweden)

    Thomas Semenou

    2015-01-01

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

  9. Solar Schematic

    Science.gov (United States)

    1979-01-01

    The home shown at right is specially designed to accommodate solar heating units; it has roof planes in four directions, allowing placement of solar collectors for best exposure to the sun. Plans (bottom) and complete working blueprints for the solar-heated house are being marketed by Home Building Plan Service, Portland, Oregon. The company also offers an inexpensive schematic (center) showing how a homeowner only moderately skilled in the use of tools can build his own solar energy system, applicable to new or existing structures. The schematic is based upon the design of a low-cost solar home heating system built and tested by NASA's Langley Research Center; used to supplement a warm-air heating system, it can save the homeowner about 40 percent of his annual heating bill for a modest investment in materials and components. Home Building Plan Service saved considerable research time by obtaining a NASA technical report which details the Langley work. The resulting schematic includes construction plans and simplified explanations of solar heat collection, collectors and other components, passive heat factors, domestic hot water supply and how to work with local heating engineers.

  10. Solar PV Manufacturing Cost Model Group: Installed Solar PV System Prices (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Goodrich, A. C.; Woodhouse, M.; James, T.

    2011-02-01

    EERE's Solar Energy Technologies Program is charged with leading the Secretary's SunShot Initiative to reduce the cost of electricity from solar by 75% to be cost competitive with conventional energy sources without subsidy by the end of the decade. As part of this Initiative, the program has funded the National Renewable Energy Laboratory (NREL) to develop module manufacturing and solar PV system installation cost models to ensure that the program's cost reduction targets are carefully aligned with current and near term industry costs. The NREL cost analysis team has leveraged the laboratories' extensive experience in the areas of project finance and deployment, as well as industry partnerships, to develop cost models that mirror the project cost analysis tools used by project managers at leading U.S. installers. The cost models are constructed through a "bottoms-up" assessment of each major cost element, beginning with the system's bill of materials, labor requirements (type and hours) by component, site-specific charges, and soft costs. In addition to the relevant engineering, procurement, and construction costs, the models also consider all relevant costs to an installer, including labor burdens and overhead rates, supply chain costs, and overhead and materials inventory costs, and assume market-specific profits.

  11. Fiscal 1976 Sunshine Project result report. R and D on solar cooling/heating and hot water supply system (R and D on the system for apartment houses); 1976 nendo taiyo reidanbo oyobi kyuto system no kenkyu kaihatsu seika hokokusho. Shugo jutakuyo system no kenkyu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1977-03-01

    This report describes the fiscal 1976 research result on solar cooling/heating and hot water supply system for apartment houses. In the system research, comparative study was made on facility costs and operation costs per heat load between previous and solar cooling/heating and hot water supply systems for apartment houses. In the working design for apartment houses, various calculation necessary for start of work, and preparation of detail drawings and specifications were made. In development of solar collector, the test loop and collector were prepared using full-scale collector elements for medium-scale performance tests. In development of heat accumulator, inorganic hydrate was selected as heat storage material using latent heat for the confirmation test of basic physical properties. In development of solar cooling/heating equipment, the confirmation test of Rankine engine's performance, controllability and durability was made under real load. In addition, the refrigerator of nearly 20 tons of refrigeration driven by Rankine engine was fabricated, (NEDO)

  12. Models for prediction of global solar radiation on horizontal surface ...

    African Journals Online (AJOL)

    The estimation of global solar radiation continues to play a fundamental role in solar engineering systems and applications. This paper compares various models for estimating the average monthly global solar radiation on horizontal surface for Akure, Nigeria, using solar radiation and sunshine duration data covering years ...

  13. A pilot solar water disinfecting system: performance analysis and testing

    Energy Technology Data Exchange (ETDEWEB)

    Saitoh, T.S.; El-Ghetany, H.H. [Tohoku University, Sendai (Japan). Dept. of Aeronautics and Space Engineering

    2002-07-01

    In most countries, contaminated water is the major cause of most water-borne diseases. Disinfection of water may be accomplished by a number of different physical-chemical treatments including direct application of thermal energy, chemical and filtration techniques. Solar energy also can be used effectively in this field because inactivation of microorganisms is done either by heating water to a disinfecting temperature or by exposing it to ultraviolet solar radiation. A pilot solar system for disinfecting contaminated water is designed, constructed and tested. Investigations are carried out to evaluate the performance of a wooden hot box solar facility as a solar disinfectant. Experimental data show that solar energy is viable for the disinfection process. A solar radiation model is presented and compared with the experimental data. A mathematical model of the solar disinfectant is also presented. The governing equations are solved numerically via the fourth-order Runge-Kutta method. The effects of environmental conditions (ambient temperature, wind speed, solar radiation, etc.) on the performance of the solar disinfectant are examined. Results showed that the system is affected by ambient temperature, wind speed, ultraviolet solar radiation intensity, the turbidity of the water, the quantity of water exposed, the contact area between the transparent water container in the solar disinfectant and the absorber plate as well as the geometrical parameters of the system. It is pointed out that for partially cloudy conditions with a low ambient temperature and high wind speeds, the thermal efficiency of the solar disinfectant is at a minimum. The use of solar energy for the disinfection process will increase the productivity of the system while completely eliminating the coliform group bacteria at the same time. (author)

  14. Development of Inorganic Solar Cells by Nano-technology

    Institute of Scientific and Technical Information of China (English)

    Yafei Zhang; HueyLiang Hwang; Huijuan Geng; Zhihua Zhou; Jiang Wu; Zhiming Wang; Yaozhong Zhang; Zhongli Li; Liying Zhang; Zhi Yang

    2012-01-01

    Inorganic solar cells, as durable photovoltaic devices for harvesting electric energy from sun light, have received tremendous attention due to the fear of exhausting the earth’s energy resources and damaging the living environment due to greenhouse gases. Some recent developments in nanotechnology have opened up new avenues for more relevant inorganic solar cells produced by new photovoltaic conversion concepts and effective solar energy harvesting nanostructures. In this review, the multiple exciton generation effect solar cells, hot carrier solar cells, one dimensional material constructed asymmetrical schottky barrier arrays, noble nanoparticle induced plasmonic enhancement, and light trapping nanostructured semiconductor solar cells are highlighted.

  15. The influence of the solar radiation model on the calcutated solar radiation from a horizontal surface to a tilted surface

    DEFF Research Database (Denmark)

    Andersen, Elsa; Lund, Hans; Furbo, Simon

    2004-01-01

    Measured solar radiation data are most commonly available as total solar radiation on a horizontal surface. When using solar radiation measured on horizontal to calculate the solar radiation on tilted surfaces and thereby the thermal performance of different applications such as buildings and solar...... heating systems, different solar radiation models can be used. The calculation of beam radiation from a horizontal surface to a tilted surface can be done exactly whereas different solar radiation models can calculate the sky diffuse radiation. The sky diffuse radiation can either be assumed evenly...... in the calculation. The weather data are measured at the solar radiation measurement station, SMS at the Department of Civil Engineering at the Technical University of Denmark. In this study the weather data are combined with solar collector calculations based on solar collector test carried out at Solar Energy...

  16. Modelling the solar wind interaction with Mercury by a quasi-neutral hybrid model

    Directory of Open Access Journals (Sweden)

    E. Kallio

    2003-11-01

    Full Text Available Quasi-neutral hybrid model is a self-consistent modelling approach that includes positively charged particles and an electron fluid. The approach has received an increasing interest in space plasma physics research because it makes it possible to study several plasma physical processes that are difficult or impossible to model by self-consistent fluid models, such as the effects associated with the ions’ finite gyroradius, the velocity difference between different ion species, or the non-Maxwellian velocity distribution function. By now quasi-neutral hybrid models have been used to study the solar wind interaction with the non-magnetised Solar System bodies of Mars, Venus, Titan and comets. Localized, two-dimensional hybrid model runs have also been made to study terrestrial dayside magnetosheath. However, the Hermean plasma environment has not yet been analysed by a global quasi-neutral hybrid model. In this paper we present a new quasi-neutral hybrid model developed to study various processes associated with the Mercury-solar wind interaction. Emphasis is placed on addressing advantages and disadvantages of the approach to study different plasma physical processes near the planet. The basic assumptions of the approach and the algorithms used in the new model are thoroughly presented. Finally, some of the first three-dimensional hybrid model runs made for Mercury are presented. The resulting macroscopic plasma parameters and the morphology of the magnetic field demonstrate the applicability of the new approach to study the Mercury-solar wind interaction globally. In addition, the real advantage of the kinetic hybrid model approach is to study the property of individual ions, and the study clearly demonstrates the large potential of the approach to address these more detailed issues by a quasi-neutral hybrid model in the future.Key words. Magnetospheric physics (planetary magnetospheres; solar wind-magnetosphere interactions – Space plasma

  17. Prediction of hot spots in protein interfaces using a random forest model with hybrid features.

    Science.gov (United States)

    Wang, Lin; Liu, Zhi-Ping; Zhang, Xiang-Sun; Chen, Luonan

    2012-03-01

    Prediction of hot spots in protein interfaces provides crucial information for the research on protein-protein interaction and drug design. Existing machine learning methods generally judge whether a given residue is likely to be a hot spot by extracting features only from the target residue. However, hot spots usually form a small cluster of residues which are tightly packed together at the center of protein interface. With this in mind, we present a novel method to extract hybrid features which incorporate a wide range of information of the target residue and its spatially neighboring residues, i.e. the nearest contact residue in the other face (mirror-contact residue) and the nearest contact residue in the same face (intra-contact residue). We provide a novel random forest (RF) model to effectively integrate these hybrid features for predicting hot spots in protein interfaces. Our method can achieve accuracy (ACC) of 82.4% and Matthew's correlation coefficient (MCC) of 0.482 in Alanine Scanning Energetics Database, and ACC of 77.6% and MCC of 0.429 in Binding Interface Database. In a comparison study, performance of our RF model exceeds other existing methods, such as Robetta, FOLDEF, KFC, KFC2, MINERVA and HotPoint. Of our hybrid features, three physicochemical features of target residues (mass, polarizability and isoelectric point), the relative side-chain accessible surface area and the average depth index of mirror-contact residues are found to be the main discriminative features in hot spots prediction. We also confirm that hot spots tend to form large contact surface areas between two interacting proteins. Source data and code are available at: http://www.aporc.org/doc/wiki/HotSpot.

  18. On the model of symbiotic stars

    International Nuclear Information System (INIS)

    Tutukov, A.V.; Yungelson, L.R.

    1982-01-01

    The authors discuss conditions necessary for appearance and discovery of the symbiotic star phenomenon within the model of a binary consisting of a red (super)giant 3 solar masses not filling the Roche lobe and of an accreting hot degenerate CO-dwarf 0.8 solar masses. Within this model ''classical'' symbiotic stars may exist only within a narrow region of mass accretion rates and separations of components: 10 -7 approximately -7 solar masses/y and 3x10 13 approximately 14 cm. The evolutionary status of symbiotic stars and related objects and the mechanisms of their variability are discussed. (Auth.)

  19. Evaluation of Applicability of Global Solar Radiation Prediction Models for Kocaeli

    Directory of Open Access Journals (Sweden)

    Nurullah ARSLANOĞLU

    2016-04-01

    Full Text Available Design and analyses of solar energy systems needs value of global solar radiation falling on the surface of the earth. In this study,  thirty relative sunshine duration based regression models in the literature for determining the monthly average daily global solar radiation on a horizontal surface for Kocaeli were investigated. To indicate the performance of the models, the following statistical test methods are used: mean absolute bias error (MABE, mean bias error (MBE, mean absolute percent error (MAPE, mean percent error (MPE, root mean square error (RMSE. According to the statistical performance, Lewis model (Model 23, Model-18 (Jin et al. and Model 8 (Bahel et al. showed the best estimation of the global solar radiation on a horizontal surface for Kocaeli.

  20. Electrical equivalent model of intermediate band solar cell using ...

    Indian Academy of Sciences (India)

    presents a structure of IBSC based on ZnTe:O. The proposed model uses irradiance and temperature as ... of solar cells. They are based on different processes and properties such as photon recycling, ... The MATLAB interface was used .... ioral model of an arbitrary solar cell to amend the PSPICE simulation performance.