WorldWideScience

Sample records for thermal energy carrier

  1. The energy carrier hydrogen

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    The potential of hydrogen to be used as a clean fuel for the production of heat and power, as well as for the propulsion of aeroplanes and vehicles, is described, in particular for Germany. First, attention is paid to the application of hydrogen as a basic material for the (petro)chemical industry, as an indirect energy source for (petro)chemical processes, and as a direct energy source for several purposes. Than the importance of hydrogen as an energy carrier in a large-scale application of renewable energy sources is discussed. Next an overview is given of new and old hydrogen production techniques from fossil fuels, biomass, or the electrolysis of water. Energetic applications of hydrogen in the transportation sector and the production of electric power and heat are mentioned. Brief descriptions are given of techniques to store hydrogen safely. Finally attention is paid to hydrogen research in Germany. Two hydrogen projects, in which Germany participates, are briefly dealt with: the Euro-Quebec project (production of hydrogen by means of hydropower), and the HYSOLAR project (hydrogen production by means of solar energy). 18 figs., 1 tab., 7 refs

  2. The energy-carriers

    International Nuclear Information System (INIS)

    Van Rensburg, W.C.J.

    1975-01-01

    Mining, processing and transport of minerals use the major proportion of South Africas total energy in various forms. With the Republic committed to expand these activities very substantially, will the necessary energy in the right forms be available

  3. Seasonal thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Allen, R.D.; Kannberg, L.D.; Raymond, J.R.

    1984-05-01

    This report describes the following: (1) the US Department of Energy Seasonal Thermal Energy Storage Program, (2) aquifer thermal energy storage technology, (3) alternative STES technology, (4) foreign studies in seasonal thermal energy storage, and (5) economic assessment.

  4. Wuestite - a solar energy carrier

    Energy Technology Data Exchange (ETDEWEB)

    Weidenkaff, A.; Nueesch, P.; Wokaun, A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Reller, A. [Hamburg Univ., Hamburg (Germany)

    1997-06-01

    Hydrogen is produced when Wuestite (Fe{sub 1-y}O) is oxidised by water. This reaction is part of a two-step thermochemical metal oxide cycle for the storage of solar energy in the form of chemical energy carriers, characterised by a high chemical potential. The reaction was studied in a tubular furnace with on-line gas analysis and further characterised in detail by DTA und high-temperature X-ray powder diffraction. The influence of non-stoichiometry, morphology and temperature on the mechanism and kinetics of the water-splitting reaction was determined. (author) 3 figs., tabs., 3 refs.

  5. Hydrogen: the future energy carrier.

    Science.gov (United States)

    Züttel, Andreas; Remhof, Arndt; Borgschulte, Andreas; Friedrichs, Oliver

    2010-07-28

    Since the beginning of the twenty-first century the limitations of the fossil age with regard to the continuing growth of energy demand, the peaking mining rate of oil, the growing impact of CO2 emissions on the environment and the dependency of the economy in the industrialized world on the availability of fossil fuels became very obvious. A major change in the energy economy from fossil energy carriers to renewable energy fluxes is necessary. The main challenge is to efficiently convert renewable energy into electricity and the storage of electricity or the production of a synthetic fuel. Hydrogen is produced from water by electricity through an electrolyser. The storage of hydrogen in its molecular or atomic form is a materials challenge. Some hydrides are known to exhibit a hydrogen density comparable to oil; however, these hydrides require a sophisticated storage system. The system energy density is significantly smaller than the energy density of fossil fuels. An interesting alternative to the direct storage of hydrogen are synthetic hydrocarbons produced from hydrogen and CO2 extracted from the atmosphere. They are CO2 neutral and stored like fossil fuels. Conventional combustion engines and turbines can be used in order to convert the stored energy into work and heat.

  6. Methanol as an energy carrier

    Energy Technology Data Exchange (ETDEWEB)

    Biedermann, P.; Grube, T.; Hoehlein, B. (eds.)

    2006-07-01

    For the future, a strongly growing energy demand is expected in the transport sector worldwide. Economically efficient oil production will run through a maximum in the next decade. Higher fuel prices and an environmentally desirable reduction of emissions will increase the pressure for reducing fuel consumption and emissions in road traffic. These criteria show the urgent necessity of structural changes in the fuel market. Due to its advantages concerning industrial-scale production, storage and global availability, methanol has the short- to medium-term potential for gaining increased significance as a substitution product in the energy market. Methanol can be produced both from fossil energy sources and from biomass or waste materials through the process steps of synthesis gas generation with subsequent methanol synthesis. Methanol has the potential to be used in an environmentally friendly manner in gasoline/methanol mixtures for flexible fuel vehicles with internal combustion engines and in diesel engines with pure methanol. Furthermore, it can be used in fuel cell vehicles with on-board hydrogen production in direct methanol fuel cell drives, and in stationary systems for electricity and heat generation as well as for hydrogen production. Finally, in portable applications it serves as an energy carrier for electric power generation. In this book, the processes for the production and use of methanol are presented and evaluated, markets and future options are discussed and issues of safety and environmental impacts are addressed by a team of well-known authors. (orig.)

  7. Photo-generated carriers lose energy during extraction from polymer-fullerene solar cells

    KAUST Repository

    Melianas, Armantas

    2015-11-05

    In photovoltaic devices, the photo-generated charge carriers are typically assumed to be in thermal equilibrium with the lattice. In conventional materials, this assumption is experimentally justified as carrier thermalization completes before any significant carrier transport has occurred. Here, we demonstrate by unifying time-resolved optical and electrical experiments and Monte Carlo simulations over an exceptionally wide dynamic range that in the case of organic photovoltaic devices, this assumption is invalid. As the photo-generated carriers are transported to the electrodes, a substantial amount of their energy is lost by continuous thermalization in the disorder broadened density of states. Since thermalization occurs downward in energy, carrier motion is boosted by this process, leading to a time-dependent carrier mobility as confirmed by direct experiments. We identify the time and distance scales relevant for carrier extraction and show that the photo-generated carriers are extracted from the operating device before reaching thermal equilibrium.

  8. Solar Thermal Energy Technology

    Energy Technology Data Exchange (ETDEWEB)

    Cason, D.L.; Pitsenbarger, J. [eds.

    1996-02-01

    Solar Thermal Energy Technology (PST) announces on a bimonthly basis the current worldwide research and development information that would expand the technology base required for the advancement of solar thermal systems as a significant energy resource.

  9. Efficient optical extraction of hot-carrier energy

    NARCIS (Netherlands)

    Saeed, S.; de Jong, E.M.L.D.; Dohnalova, K.; Gregorkiewicz, T.

    2014-01-01

    Light-induced generation of free charge carriers in semiconductors constitutes the physical basis of photodetection and photovoltaics. To maximize its efficiency, the energy of the photons must be entirely used for this purpose. This is highly challenging owing to the ultrafast thermalization of

  10. Thermal energy storage

    Science.gov (United States)

    Grodzka, P. G.; Picklesimer, E. A.

    1978-01-01

    The general scope of study on thermal energy storage development includes: (1) survey and review possible concepts for storing thermal energy; (2) evaluate the potentials of the surveyed concepts for practical applications in the low and high temperature ranges for thermal control and storage, with particular emphasis on the low temperature range, and designate the most promising concepts; and (3) determine the nature of further studies required to expeditiously convert the most promising concept(s) to practical applications. Cryogenic temperature control by means of energy storage materials was also included.

  11. Ocean Thermal Energy.

    Science.gov (United States)

    Berkovsky, Boris

    1987-01-01

    Describes Ocean Thermal Energy Conservation (OTEC) as a method for exploiting the temperature difference between warm surface waters of the sea and its cold depths. Argues for full-scale demonstrations of the technique for producing energy for coastal regions. (TW)

  12. Competitive position of energy carriers in trade

    Energy Technology Data Exchange (ETDEWEB)

    Suding, P.H.; Forsbach, H.H.

    Industrial consumers and public institutions, which are classed with the group of minor consumers, differ in their behaviour in energy consumption greatly from the structure of the whole group. Also the willingness to convert from fuel oil to natural gas in these trade groups is relatively high. Within the framework of 5 model enterprises, the profitability of energy carriers and economizing technology in trade is analysed. The model enterprises are a bakery, a meat purveyor, a restaurant, a laundry and a hospital. The basic data are compared with the data from 1985. The comparison shows that the competitive positions of energy carriers in business and public in the process heat sector here not changed dramatically. The competitiveness of natural gas has improved since 1985 through the changes in price. However, in the sectors in which it belongs to the group of economical alternatives (e.g. in the bakeries), electricity has not lost much ground. (BR)

  13. Hydrogen, an energy carrier with a future

    International Nuclear Information System (INIS)

    Zimmer, K.H.

    1975-01-01

    The inefficient use, associated with pollutants, of the fossil energy carriers coal, crude oil and natural gas, will deplete resources, if the energy demand increases exponentially, in the not-too-distant future. That is the reason why the hydrogen-energy concept gains in importance. This requires drastic changes in structure in a lot of technological fields. This task is only to be mastered if there is cooperation between all special fields, in order to facilitate the economical production, distribution and utilization of hydrogen. (orig.) [de

  14. Pathways to hydrogen as an energy carrier.

    Science.gov (United States)

    Sigfusson, Thorsteinn I

    2007-04-15

    When hydrogen is used as an alternative energy carrier, it is very important to understand the pathway from the primary energy source to the final use of the carrier. This involves, for example, the understanding of greenhouse gas emissions associated with the production of hydrogen and throughout the lifecycle of a given utilization pathway as well as various energy or exergy efficiencies and aspects involved. This paper which is based on a talk given at the Royal Society in London assesses and reviews the various production pathways for hydrogen with emphasis on emissions, energy use and energy efficiency. The paper also views some aspects of the breaking of the water molecule and examines some new emerging physical evidence which could pave the way to a new and more feasible pathway. A special attention will be given to the use of the renewable energy pathway. As an example of a hydrogen society that could be based on renewable primary energy, the paper describes the hydrogen society experiments in Iceland as well as unconventional hydrogen obtained from geothermal gases. In the light of our experience, attempts will be made to shed light upon drivers as well as obstacles in the development of a hydrogen society.

  15. Formic Acid as a Hydrogen Energy Carrier

    KAUST Repository

    Eppinger, Jorg

    2016-12-15

    The high volumetric capacity (S3 g H-2/L) and its low toxicity and flammability under ambient conditions make formic acid a promising hydrogen energy carrier. Particularly, in the past decade, significant advancements have been achieved in catalyst development for selective hydrogen generation from formic acid. This Perspective highlights the advantages of this approach with discussions focused on potential applications in the transportation sector together with analysis of technical requirements, limitations, and costs.

  16. Thermal energy storage material

    Science.gov (United States)

    Leifer, Leslie

    1976-01-01

    A thermal energy storage material which is stable at atmospheric temperature and pressure and has a melting point higher than 32.degree.F. is prepared by dissolving a specific class of clathrate forming compounds, such as tetra n-propyl or tetra n-butyl ammonium fluoride, in water to form a substantially solid clathrate. The resultant thermal energy storage material is capable of absorbing heat from or releasing heat to a given region as it transforms between solid and liquid states in response to temperature changes in the region above and below its melting point.

  17. Thermal energy storage

    Science.gov (United States)

    Tomlinson, J. J.

    1992-03-01

    The Department of Energy (DOE) is supporting development of thermal energy storage (TES) as a means of efficiently coupling energy supplies to variable heating or cooling demands. Uses of TES include electrical demand-side management in buildings and industry, extending the utilization of renewable energy resources such as solar, and recovery of waste heat from periodic industrial processes. Technical progress to develop TES for specific diurnal and industrial applications under Oak Ridge National Laboratory's TES program from April 1990 to March 1992 is reported and covers research in the areas of low temperature sorption, direct contact ice making, latent heat storage plasterboard and latent/sensible heat regenerator technology development.

  18. Solar thermal energy receiver

    Science.gov (United States)

    Baker, Karl W. (Inventor); Dustin, Miles O. (Inventor)

    1992-01-01

    A plurality of heat pipes in a shell receive concentrated solar energy and transfer the energy to a heat activated system. To provide for even distribution of the energy despite uneven impingement of solar energy on the heat pipes, absence of solar energy at times, or failure of one or more of the heat pipes, energy storage means are disposed on the heat pipes which extend through a heat pipe thermal coupling means into the heat activated device. To enhance energy transfer to the heat activated device, the heat pipe coupling cavity means may be provided with extensions into the device. For use with a Stirling engine having passages for working gas, heat transfer members may be positioned to contact the gas and the heat pipes. The shell may be divided into sections by transverse walls. To prevent cavity working fluid from collecting in the extensions, a porous body is positioned in the cavity.

  19. Thermal detection of trapped charge carriers in organic transport materials

    Science.gov (United States)

    von Malm, Norwin; Steiger, Juergen; Finnberg, Torsten; Schmechel, Roland; von Seggern, Heinz

    2003-03-01

    The effect of trap states on the transport and luminescence properties of organic light emitting diodes (OLEDs) is studied. For trap level detection energy resolved thermally stimulated current (TSC) measurements known as fractional glow are utilized to determine the density of occupied states (DOOS) in various organic semiconductors such as the small molecule systems Alq3 [aluminum tris(8-hydroxyquinoline)], 1-NaphDATA {4,4',4"-tris-[N-(1-naphtyl)-N-phenylamino]-triphenylamine} and α-NPD [N,N'-di-(1-naphthyl)-N,N'-diphenylbenzidine] and the polymeric semiconductor MDMO-PPV {poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylenevinylene]}. Characteristic differences in the trap spectra are obtained and interpreted in terms of possible structural and compositional origins of the investigated materials. In order to judge the formation process of traps and their practical consequences on the charge carrier transport I-V and L-V characteristics of 1-NaphDATA doped α-NPD devices and α-NPD doped 1-NaphDATA devices were compared to respective non-doped samples. A clearly reduced current and luminescence was found only in the former case. It was possible to conclude that the detected electronic trap states either act as hole traps or as scattering centers. Furthermore, pulsed transport studies on ITO/α-NPD/Alq3/Al devices show thte critical influence of traps on the dynamical performance of the charge transport. In a two-pulse experiment the carrier injection and trap depletion can be separated.

  20. Article for thermal energy storage

    Science.gov (United States)

    Salyer, Ival O.

    2000-06-27

    A thermal energy storage composition is provided which is in the form of a gel. The composition includes a phase change material and silica particles, where the phase change material may comprise a linear alkyl hydrocarbon, water/urea, or water. The thermal energy storage composition has a high thermal conductivity, high thermal energy storage, and may be used in a variety of applications such as in thermal shipping containers and gel packs.

  1. Thermal Energy Conversion Branch

    Science.gov (United States)

    Bielozer, Matthew C.; Schreiber, Jeffrey, G.; Wilson, Scott D.

    2004-01-01

    The Thermal Energy Conversion Branch (5490) leads the way in designing, conducting, and implementing research for the newest thermal systems used in space applications at the NASA Glenn Research Center. Specifically some of the most advanced technologies developed in this branch can be broken down into four main areas: Dynamic Power Systems, Primary Solar Concentrators, Secondary Solar Concentrators, and Thermal Management. Work was performed in the Dynamic Power Systems area, specifically the Stirling Engine subdivision. Today, the main focus of the 5490 branch is free-piston Stirling cycle converters, Brayton cycle nuclear reactors, and heat rejection systems for long duration mission spacecraft. All space exploring devices need electricity to operate. In most space applications, heat energy from radioisotopes is converted to electrical power. The Radioisotope Thermoelectric Generator (RTG) already supplies electricity for missions such as the Cassini Spacecraft. The focus of today's Stirling research at GRC is aimed at creating an engine that can replace the RTG. The primary appeal of the Stirling engine is its high system efficiency. Because it is so efficient, the Stirling engine will significantly reduce the plutonium fuel mission requirements compared to the RTG. Stirling is also being considered for missions such as the lunar/Mars bases and rovers. This project has focused largely on Stirling Engines of all types, particularly the fluidyne liquid piston engine. The fluidyne was developed by Colin D. West. This engine uses the same concepts found in any type of Stirling engine, with the exception of missing mechanical components. All the working components are fluid. One goal was to develop and demonstrate a working Stirling Fluidyne Engine at the 2nd Annual International Energy Conversion Engineering Conference in Providence, Rhode Island.

  2. Waste energy harvesting mechanical and thermal energies

    CERN Document Server

    Ling Bing, Kong; Hng, Huey Hoon; Boey, Freddy; Zhang, Tianshu

    2014-01-01

    Waste Energy Harvesting overviews the latest progress in waste energy harvesting technologies, with specific focusing on waste thermal mechanical energies. Thermal energy harvesting technologies include thermoelectric effect, storage through phase change materials and pyroelectric effect. Waste mechanical energy harvesting technologies include piezoelectric (ferroelectric) effect with ferroelectric materials and nanogenerators. The book aims to strengthen the syllabus in energy, materials and physics and is well suitable for students and professionals in the fields.

  3. Increased Thermal Conductivity in Metal-Organic Heat Carrier Nanofluids.

    Science.gov (United States)

    Nandasiri, Manjula I; Liu, Jian; McGrail, B Peter; Jenks, Jeromy; Schaef, Herbert T; Shutthanandan, Vaithiyalingam; Nie, Zimin; Martin, Paul F; Nune, Satish K

    2016-06-15

    Metal-organic heat carriers (MOHCs) are recently developed nanofluids containing metal-organic framework (MOF) nanoparticles dispersed in various base fluids including refrigerants (R245Fa) and methanol. Here, we report the synthesis and characterization of MOHCs containing nanoMIL-101(Cr) and graphene oxide (GO) in an effort to improve the thermo-physical properties of various base fluids. MOHC/GO nanocomposites showed enhanced surface area, porosity, and nitrogen adsorption compared with the intrinsic nanoMIL-101(Cr) and the properties depended on the amount of GO added. MIL-101(Cr)/GO in methanol exhibited a significant increase in the thermal conductivity (by approximately 50%) relative to that of the intrinsic nanoMIL-101(Cr) in methanol. The thermal conductivity of the base fluid (methanol) was increased by about 20%. The increase in the thermal conductivity of nanoMIL-101(Cr) MOHCs due to GO functionalization is explained using a classical Maxwell model.

  4. Thermal energy test apparatus

    Science.gov (United States)

    Audet, N. F.

    1991-10-01

    The Navy Clothing and Textile Research Facility (NCTRF) designed and fabricated a thermal energy test apparatus to permit evaluation of the heat protection provided by crash crew firefighter's proximity clothing materials against radiant and convective heat loads, similar to those found outside the flame zone of aircraft fuel fires. The apparatus employs electrically operated quartz lamp radiant heaters and a hot air convective heater assembly to produce the heat load conditions the materials to be subjected to, and is equipped with heat flux sensors of different sensitivities to measure the incident heat flux on the sample material as well as the heat flux transmitted by the sample. Tests of the apparatus have shown that it can produce radiant heat flux levels equivalent to those estimated to be possible in close proximity to large aircraft fuel fires, and can produce convective heat fluxes equivalent to those measured in close proximity to aircraft fuel fires at upwind and sidewind locations. Work was performed in 1974.

  5. Decarbonized fossil energy carriers and their energy technology competitors

    International Nuclear Information System (INIS)

    Williams, R.H.

    2003-01-01

    Stabilizing atmospheric CO2 in the range 450-550 ppmv requires deep reductions in CO2 emissions for both electricity generation and markets that use fuels directly. Fossil fuel decarbonization/ CO2 storage is an important option for reducing emissions from the power sector, but there are alternative non-carbon-based electricity options that will be strong competitors in terms of cost. Because of land-use constraints, use of carbon-neutral biofuels alone will be inadequate to solve the climate problem in markets that use fuels directly, so that it will probably also be necessary to introduce H2 as an energy carrier. Costs for H2 from fossil fuels with storage of the separated CO2 are likely to be far less than costs of making H2 from water using carbon-free (renewable or nuclear) electricity or heat sources. Although CO2 capture and storage associated with making H2 via gasification of coal and other carbonaceous feedstocks offers one of the least-costly approaches to a climate-friendly energy future, H2 will not be widely used as an energy carrier for at least two decades. Nevertheless, thus making H2 to serve industrial markets can provide low-cost CO2 for CO2 storage demonstration projects, thereby playing an important near-term role in understanding better the prospects for coping with climate change via decarbonizing fossil fuels and CO2 storage

  6. Characterization of thermal, optical and carrier transport properties of porous silicon using the photoacoustic technique

    International Nuclear Information System (INIS)

    Sheng, Chan Kok; Mahmood Mat Yunus, W.; Yunus, Wan Md. Zin Wan; Abidin Talib, Zainal; Kassim, Anuar

    2008-01-01

    In this work, the porous silicon layer was prepared by the electrochemical anodization etching process on n-type and p-type silicon wafers. The formation of the porous layer has been identified by photoluminescence and SEM measurements. The optical absorption, energy gap, carrier transport and thermal properties of n-type and p-type porous silicon layers were investigated by analyzing the experimental data from photoacoustic measurements. The values of thermal diffusivity, energy gap and carrier transport properties have been found to be porosity-dependent. The energy band gap of n-type and p-type porous silicon layers was higher than the energy band gap obtained for silicon substrate (1.11 eV). In the range of porosity (50-76%) of the studies, our results found that the optical band-gap energy of p-type porous silicon (1.80-2.00 eV) was higher than that of the n-type porous silicon layer (1.70-1.86 eV). The thermal diffusivity value of the n-type porous layer was found to be higher than that of the p-type and both were observed to increase linearly with increasing layer porosity

  7. Hydrogen as an energy carrier. 2. rev. and enlarged ed.

    International Nuclear Information System (INIS)

    Winter, C.J.; Nitsch, J.

    1991-01-01

    This book deals with the possibilities of an energetic utilisation of hydrogen. This energy carrier can be produced from the unlimited energy sources - solar energy, wind energy and hydropower - and from nuclear energy. It is also capable of one day supplementing or superseding the fossil energy carriers oil, coal and gas. What is special about the book is that it goes beyond a mere physical/technical description to discuss the economic and political aspects and ecological effects and requirements that are an essential part of sound energy planning today. Thus, the authors and editors outline the step-by-step development of a hydrogen economy, mainly based on solar energy, providing a solution to both the pollution problems caused by the use of fossil energy carriers and the energy requirements of the third world. (orig.) With 197 figs., 71 tabs

  8. Heat to electricity conversion by cold carrier emissive energy harvesters

    Energy Technology Data Exchange (ETDEWEB)

    Strandberg, Rune [Department of Engineering Sciences, University of Agder, Jon Lilletuns vei 9, 4879 Grimstad (Norway)

    2015-12-07

    This paper suggests a method to convert heat to electricity by the use of devices called cold carrier emissive energy harvesters (cold carrier EEHs). The working principle of such converters is explained and theoretical power densities and efficiencies are calculated for ideal devices. Cold carrier EEHs are based on the same device structure as hot carrier solar cells, but works in an opposite way. Whereas a hot carrier solar cell receives net radiation from the sun and converts some of this radiative heat flow into electricity, a cold carrier EEH sustains a net outflux of radiation to the surroundings while converting some of the energy supplied to it into electricity. It is shown that the most basic type of cold carrier EEHs have the same theoretical efficiency as the ideal emissive energy harvesters described earlier by Byrnes et al. In the present work, it is also shown that if the emission from the cold carrier EEH originates from electron transitions across an energy gap where a difference in the chemical potential of the electrons above and below the energy gap is sustained, power densities slightly higher than those given by Byrnes et al. can be achieved.

  9. Ocean thermal plantships for production of ammonia as the hydrogen carrier.

    Energy Technology Data Exchange (ETDEWEB)

    Panchal, C.B.; Pandolfini, P. P.; Kumm, W. H.; Energy Systems; Johns Hopkins Univ.; Arctic Energies, Ltd.

    2009-12-02

    Conventional petroleum, natural gas, and coal are the primary sources of energy that have underpinned modern civilization. Their continued availability in the projected quantities required and the impacts of emission of greenhouse gases (GHGs) on the environment are issues at the forefront of world concerns. New primary sources of energy are being sought that would significantly reduce the emissions of GHGs. One such primary source that can help supply energy, water, and fertilizer without GHG emissions is available in the heretofore unexploited thermal gradients of the tropical oceans. The world's oceans are the largest natural collector and reservoir of solar energy. The potential of ocean energy is limitless for producing base-load electric power or ammonia as the hydrogen carrier and fresh water from seawater. However, until now, ocean energy has been virtually untapped. The general perception is that ocean thermal energy is limited to tropical countries. Therefore, the full potential of at-sea production of (1) ammonia as a hydrogen carrier and (2) desalinated water has not been adequately evaluated. Using ocean thermal plantships for the at-sea co-production of ammonia as a hydrogen carrier and desalinated water offer potential energy, environmental, and economic benefits that support the development of the technology. The introduction of a new widespread solution to our projected energy supply requires lead times of a decade or more. Although continuation of the ocean thermal program from the 1970s would likely have put us in a mitigating position in the early 2000s, we still have a window of opportunity to dedicate some of our conventional energy sources to the development of this renewable energy by the time new sources would be critically needed. The primary objective of this project is to evaluate the technical and economic viability of ocean thermal plantships for the production of ammonia as the hydrogen carrier. This objective is achieved by

  10. Increased Thermal Conductivity in Metal-Organic Heat Carrier Nanofluids

    Energy Technology Data Exchange (ETDEWEB)

    Nandasiri, Manjula I.; Liu, Jian; McGrail, B. Peter; Jenks, Jeromy WJ; Schaef, Herbert T.; Shutthanandan, V.; Nie, Zimin; Martin, Paul F.; Nune, Satish K.

    2016-06-15

    Metal organic heat carriers (MOHCs) are recently developed nanofluids containing metal organic framework (MOF) nanoparticles dispersed in various base fluids including refrigerants (R245Fa) and methanol. MOHCs utilize the MOF properties to improve the thermo-physical properties of base fluids. Here, we report the synthesis and characterization of MOHCs containing nanoMIL-101(Cr) and graphene oxide (GO) in an effort to improve the thermo-physical properties of various base fluids. MOHC containing MIL-101(Cr)/GO nanocomposites showed enhanced surface area, porosity, and nitrogen adsorption compared with the intrinsic nano MIL-101(Cr) and the properties depend on the amount of GO added. Powder X-ray diffraction (PXRD) confirmed the preserved crystallinity of MIL-101(Cr) in all nanocomposites with the absence of any unreacted GO. Scanning electron microscopy images confirmed the presence of near spherical MIL-101(Cr) nanoparticles in the range of 40-80 nm in diameter. MOHC nanofluids containing MIL-101(Cr)/GO in methanol exhibited significant enhancement in the thermal conductivity (by approxi-mately 50%) relative to that of the intrinsic nano MIL-101(Cr) in methanol. The thermal conductivity of base fluid (methanol) was enhanced by about 20 %. The enhancement in the thermal conductivity of nanoMIL-101(Cr) MOHCs due to graphene oxide functionalization is explained using a classical Maxwell model.

  11. Ocean Thermal Extractable Energy Visualization

    Energy Technology Data Exchange (ETDEWEB)

    Ascari, Matthew [Lockheed Martin Corporation, Bethesda, MD (United States)

    2012-10-28

    The Ocean Thermal Extractable Energy Visualization (OTEEV) project focuses on assessing the Maximum Practicably Extractable Energy (MPEE) from the world’s ocean thermal resources. MPEE is defined as being sustainable and technically feasible, given today’s state-of-the-art ocean energy technology. Under this project the OTEEV team developed a comprehensive Geospatial Information System (GIS) dataset and software tool, and used the tool to provide a meaningful assessment of MPEE from the global and domestic U.S. ocean thermal resources.

  12. Lih thermal energy storage device

    Science.gov (United States)

    Olszewski, Mitchell; Morris, David G.

    1994-01-01

    A thermal energy storage device for use in a pulsed power supply to store waste heat produced in a high-power burst operation utilizes lithium hydride as the phase change thermal energy storage material. The device includes an outer container encapsulating the lithium hydride and an inner container supporting a hydrogen sorbing sponge material such as activated carbon. The inner container is in communication with the interior of the outer container to receive hydrogen dissociated from the lithium hydride at elevated temperatures.

  13. Seasonal Thermal Energy Storage Program

    Science.gov (United States)

    Minor, J. E.

    1980-01-01

    The Seasonal Thermal Energy Storage (STES) Program designed to demonstrate the storage and retrieval of energy on a seasonal basis using heat or cold available from waste or other sources during a surplus period is described. Factors considered include reduction of peak period demand and electric utility load problems and establishment of favorable economics for district heating and cooling systems for commercialization of the technology. The initial thrust of the STES Program toward utilization of ground water systems (aquifers) for thermal energy storage is emphasized.

  14. Thermal Energy Storage: Fourth Annual Review Meeting

    Science.gov (United States)

    1980-01-01

    The development of low cost thermal energy storage technologies is discussed in terms of near term oil savings, solar energy applications, and dispersed energy systems for energy conservation policies. Program definition and assessment and research and technology development are considered along with industrial storage, solar thermal power storage, building heating and cooling, and seasonal thermal storage. A bibliography on seasonal thermal energy storage emphasizing aquifer thermal energy is included.

  15. Thermal energy storage and transport

    Science.gov (United States)

    Hausz, W.

    1980-01-01

    The extraction of thermal energy from large LWR and coal fired plants for long distance transport to industrial and residential/commercial users is analyzed. Transport of thermal energy as high temperature water is shown to be considerably cheaper than transport as steam, hot oil, or molten salt over a wide temperature range. The delivered heat is competitive with user-generated heat from oil, coal, or electrode boilers at distances well over 50 km when the pipeline operates at high capacity factor. Results indicate that thermal energy storage makes meeting of even very low capacity factor heat demands economic and feasible and gives the utility flexibility to meet coincident electricity and heat demands effectively.

  16. Hydrogen: The Ultimate Fuel and Energy Carrier.

    Science.gov (United States)

    Dinga, Gustav P.

    1988-01-01

    Lists 24 frequently asked questions concerning hydrogen as a fuel with several responses given to each question. Emphasized are hydrogen production, storage, transmission, and application to various energy-consuming sectors. Summarizes current findings and research on hydrogen. An extensive bibliography is included. (ML)

  17. The Thermal Measurement of Energy

    Science.gov (United States)

    Griffiths, E. H.

    2014-08-01

    1. Introductory remarks; 2. Relation between potential and kinetic energy; 3. Table of values obtained by different observers; 4. Distinction between capacity for heat and specific heat of water; Appendix I. The thermal unit; Appendix II. Approximate methods of determining the mechanical equivalent; Appendix III. Copy of resolutions passed by the Electrical Standards Committee of the British Association in 1896.

  18. Biomass-based energy carriers in the transportation sector

    International Nuclear Information System (INIS)

    Johansson, Bengt.

    1995-03-01

    The purpose of this report is to study the technical and economic prerequisites to attain reduced carbon dioxide emissions through the use of biomass-based energy carriers in the transportation sector, and to study other environmental impacts resulting from an increased use of biomass-based energy carriers. CO 2 emission reduction per unit arable and forest land used for biomass production (kg CO 2 /ha,year) and costs for CO 2 emission reduction (SEK/kg CO 2 ) are estimated for the substitution of gasoline and diesel with rape methyl ester, biogas from lucerne, ethanol from wheat and ethanol, methanol, hydrogen and electricity from Salix and logging residues. Of the studied energy carriers, those based on Salix provide the largest CO 2 emission reduction. In a medium long perspective, the costs for CO 2 emission reduction seem to be lowest for methanol from Salix and logging residues. The use of fuel cell vehicles, using methanol or hydrogen as energy carriers, can in a longer perspective provide more energy efficient utilization of biomass for transportation than the use of internal combustion engine vehicles. 136 refs, 12 figs, 25 tabs

  19. Aquifer Thermal Energy Storage for Seasonal Thermal Energy Balance

    Science.gov (United States)

    Rostampour, Vahab; Bloemendal, Martin; Keviczky, Tamas

    2017-04-01

    Aquifer Thermal Energy Storage (ATES) systems allow storing large quantities of thermal energy in subsurface aquifers enabling significant energy savings and greenhouse gas reductions. This is achieved by injection and extraction of water into and from saturated underground aquifers, simultaneously. An ATES system consists of two wells and operates in a seasonal mode. One well is used for the storage of cold water, the other one for the storage of heat. In warm seasons, cold water is extracted from the cold well to provide cooling to a building. The temperature of the extracted cold water increases as it passes through the building climate control systems and then gets simultaneously, injected back into the warm well. This procedure is reversed during cold seasons where the flow direction is reversed such that the warmer water is extracted from the warm well to provide heating to a building. From the perspective of building climate comfort systems, an ATES system is considered as a seasonal storage system that can be a heat source or sink, or as a storage for thermal energy. This leads to an interesting and challenging optimal control problem of the building climate comfort system that can be used to develop a seasonal-based energy management strategy. In [1] we develop a control-oriented model to predict thermal energy balance in a building climate control system integrated with ATES. Such a model however cannot cope with off-nominal but realistic situations such as when the wells are completely depleted, or the start-up phase of newly installed wells, etc., leading to direct usage of aquifer ambient temperature. Building upon our previous work in [1], we here extend the mathematical model for ATES system to handle the above mentioned more realistic situations. Using our improved models, one can more precisely predict system behavior and apply optimal control strategies to manage the building climate comfort along with energy savings and greenhouse gas reductions

  20. Thermal energy storage devices, systems, and thermal energy storage device monitoring methods

    Science.gov (United States)

    Tugurlan, Maria; Tuffner, Francis K; Chassin, David P.

    2016-09-13

    Thermal energy storage devices, systems, and thermal energy storage device monitoring methods are described. According to one aspect, a thermal energy storage device includes a reservoir configured to hold a thermal energy storage medium, a temperature control system configured to adjust a temperature of the thermal energy storage medium, and a state observation system configured to provide information regarding an energy state of the thermal energy storage device at a plurality of different moments in time.

  1. Hot carrier metamaterial detectors and energy converters

    Science.gov (United States)

    Krayer, Lisa; Munday, Jeremy N.

    Metamaterials can be used to manipulate the flow of light in ways not typically available with traditional materials. Beyond their optical properties, metamaterials can be used as the basis for optoelectronic devices through the incorporation of a metal-semiconductor interface. The absorbed radiation in the metal can excite surface plasmons, which nonradiatively decay into hot electrons or holes that can be injected into the base semiconductor and contribute to photocurrent generation. In this talk, we will present our latest work on metamaterial photo-detectors and solar energy converters.

  2. Ground State Energy of Current Carriers in Graphene

    OpenAIRE

    Ratnikov, P. V.; Silin, A. P.

    2008-01-01

    The ground state energy of current carriers in graphene considered as a zero-gap semiconductor was calculated in the two-band approximation. The condition of the electronic (hole) system stability in graphene was obtained. The possibility of the zero-gap semiconductor-semimetal transition was discussed.

  3. Ohm's Law for a Bipolar Semiconductor: The Role of Carrier Concentration and Energy Nonequilibria

    Science.gov (United States)

    Lashkevych, Igor; Titov, Oleg Yu.; Gurevich, Yuri G.

    2017-01-01

    The effective linear electrical conductivity of a nondegenerate bipolar semiconductor, sandwiched between two metals, is investigated taking into account both its nonequilibrium charge carriers (both electrons and holes) and nonequilibrium temperature. We stress that even in the linear perturbative approximation both carrier concentration and energy nonequilbria arise automatically when an electrical current flows. The expression for the effective electrical conductivity is obtained and shown to depend on the electron and hole electrical conductivity, the thermal conductivity, the bandgap, charge carriers lifetimes, and both bulk and surface recombination rates. The effective electrical conductivity is equal to the classical result, i.e., the sum of the electron and hole electrical conductivities, only if the surface recombination rate at the interface is sufficiently strong or the charge carrier lifetime is sufficiently small. In this article, partial cases are considered, specifically, semiconductors with small and large thermal conductivities, semiconductors with monopolar electron and monopolar holes, strong and weak surface recombination rates, and small and large charge carrier lifetimes. Expressions for the effective electrical conductivity are obtained in all partial cases.

  4. Microwavable thermal energy storage material

    Science.gov (United States)

    Salyer, Ival O.

    1998-09-08

    A microwavable thermal energy storage material is provided which includes a mixture of a phase change material and silica, and a carbon black additive in the form of a conformable dry powder of phase change material/silica/carbon black, or solid pellets, films, fibers, moldings or strands of phase change material/high density polyethylene/ethylene-vinyl acetate/silica/carbon black which allows the phase change material to be rapidly heated in a microwave oven. The carbon black additive, which is preferably an electrically conductive carbon black, may be added in low concentrations of from 0.5 to 15% by weight, and may be used to tailor the heating times of the phase change material as desired. The microwavable thermal energy storage material can be used in food serving applications such as tableware items or pizza warmers, and in medical wraps and garments.

  5. Local Thermal Insulating Materials For Thermal Energy Storage ...

    African Journals Online (AJOL)

    Thermal insulation is one of the most important components of a thermal energy storage system. In this paper the thermal properties of selected potential local materials which can be used for high temperature insulation are presented. Thermal properties of seven different samples were measured. Samples consisted of: ...

  6. Thermal energy storage flight experiments

    Science.gov (United States)

    Namkoong, D.

    1989-01-01

    Consideration is given to the development of an experimental program to study heat transfer, energy storage, fluid movement, and void location under microgravity. Plans for experimental flight packages containing Thermal Energy Storage (TES) material applicable for advanced solar heat receivers are discussed. Candidate materials for TES include fluoride salts, salt eutectics, silicides, and metals. The development of a three-dimensional computer program to describe TES material behavior undergoing melting and freezing under microgravity is also discussed. The TES experiment concept and plans for ground and flight tests are outlined.

  7. More Efficient Solar Thermal-Energy Receiver

    Science.gov (United States)

    Dustin, M. O.

    1987-01-01

    Thermal stresses and reradiation reduced. Improved design for solar thermal-energy receiver overcomes three major deficiencies of solar dynamic receivers described in literature. Concentrator and receiver part of solar-thermal-energy system. Receiver divided into radiation section and storage section. Concentrated solar radiation falls on boiling ends of heat pipes, which transmit heat to thermal-energy-storage medium. Receiver used in number of applications to produce thermal energy directly for use or to store thermal energy for subsequent use in heat engine.

  8. Seasonal sensible thermal energy storage solutions

    Directory of Open Access Journals (Sweden)

    Lavinia Gabriela SOCACIU

    2012-08-01

    Full Text Available The thermal energy storage can be defined as the temporary storage of thermal energy at high or low temperatures. Thermal energy storage is an advances technology for storing thermal energy that can mitigate environmental impacts and facilitate more efficient and clean energy systems. Seasonal thermal energy storage has a longer thermal storage period, generally three or more months. This can contribute significantly to meeting society`s need for heating and cooling. The objectives of thermal energy storage systems are to store solar heat collected in summer for space heating in winter. This concept is not new; it is been used and developed for centuries because is playing an important role in energy conservation and contribute significantly to improving the energy efficiency and reducing the gas emissions to the atmosphere.

  9. Thermal performance and heat transport in aquifer thermal energy storage

    NARCIS (Netherlands)

    Sommer, W.T.; Doornenbal, P.J.; Drijver, B.C.; Gaans, van P.F.M.; Leusbrock, I.; Grotenhuis, J.T.C.; Rijnaarts, H.H.M.

    2014-01-01

    Aquifer thermal energy storage (ATES) is used for seasonal storage of large quantities of thermal energy. Due to the increasing demand for sustainable energy, the number of ATES systems has increased rapidly, which has raised questions on the effect of ATES systems on their surroundings as well as

  10. Hydrogen as energy carrier. Energy and discharge accounting for selected energy chains

    International Nuclear Information System (INIS)

    Jordanger, Einar; Moeller-Holst, Steffen; Maurstad, Ola; Brevik, Dag A.

    2002-10-01

    Hydrogen is viewed by many as a central energy carrier in the future energy system. Hydrogen does not give any discharges for the end user. Hydrogen may be obtained from different sources and may be used for various purposes both stationary and within communication. Central groups may have different opinions on the energy efficiency and the environmental profits of hydrogen use. This disagreement may be due to that not all the sections of the energy chain are clarified. There are also difference in opinions on when to introduce hydrogen in the energy system. The aim of this study was to make an energy and discharge account for hydrogen in some selected energy chains and compare them to alternative chains. The results of the study may contribute to helping the authorities in the work of making sensible measure employments regarding introduction of hydrogen into the Norwegian energy system. Even if the energy efficiency and discharges are two of the main factors which has to be evaluated when various energy chains are compared. It has to be emphasised that other important aspects such as costs, other environmental consequences, availability of energy sources and personal safety have not been considered. The results show that the energy efficiency and discharges vary considerably for different energy chains depending of which energy source is chosen. The energy efficiency and discharges are influenced by where in the enrage chain the conversion occurs as well. Central versus local conversion of hydrogen decides primarily how realistic the CO2 handling is (costs) and how much of the disused heat may be utilised. For stationary consumption it is shown that the energy chains with hydrogen give lower energy efficiency compared to the relevant reference chains (same energy source). For the discharges it is more determining which energy source and conversion technology is chosen than whether hydrogen is the source. For communication hydrogen has the advantage as energy

  11. A hydrogen energy carrier. Volume 2: Systems analysis

    Science.gov (United States)

    Savage, R. L. (Editor); Blank, L. (Editor); Cady, T. (Editor); Cox, K. (Editor); Murray, R. (Editor); Williams, R. D. (Editor)

    1973-01-01

    A systems analysis of hydrogen as an energy carrier in the United States indicated that it is feasible to use hydrogen in all energy use areas, except some types of transportation. These use areas are industrial, residential and commercial, and electric power generation. Saturation concept and conservation concept forecasts of future total energy demands were made. Projected costs of producing hydrogen from coal or from nuclear heat combined with thermochemical decomposition of water are in the range $1.00 to $1.50 per million Btu of hydrogen produced. Other methods are estimated to be more costly. The use of hydrogen as a fuel will require the development of large-scale transmission and storage systems. A pipeline system similar to the existing natural gas pipeline system appears practical, if design factors are included to avoid hydrogen environment embrittlement of pipeline metals. Conclusions from the examination of the safety, legal, environmental, economic, political and societal aspects of hydrogen fuel are that a hydrogen energy carrier system would be compatible with American values and the existing energy system.

  12. Increased Thermal Conductivity in Metal-Organic Heat Carrier Nanofluids

    OpenAIRE

    Manjula I. Nandasiri; Jian Liu; B. Peter McGrail; Jeromy Jenks; Herbert T. Schaef; Vaithiyalingam Shutthanandan; Zimin Nie; Paul F. Martin; Satish K. Nune

    2016-01-01

    Metal-organic heat carriers (MOHCs) are recently developed nanofluids containing metal-organic framework (MOF) nanoparticles dispersed in various base fluids including refrigerants (R245Fa) and methanol. Here, we report the synthesis and characterization of MOHCs containing nanoMIL-101(Cr) and graphene oxide (GO) in an effort to improve the thermo-physical properties of various base fluids. MOHC/GO nanocomposites showed enhanced surface area, porosity, and nitrogen adsorption compared with th...

  13. Solar energy thermally powered electrical generating system

    Science.gov (United States)

    Owens, William R. (Inventor)

    1989-01-01

    A thermally powered electrical generating system for use in a space vehicle is disclosed. The rate of storage in a thermal energy storage medium is controlled by varying the rate of generation and dissipation of electrical energy in a thermally powered electrical generating system which is powered from heat stored in the thermal energy storage medium without exceeding a maximum quantity of heat. A control system (10) varies the rate at which electrical energy is generated by the electrical generating system and the rate at which electrical energy is consumed by a variable parasitic electrical load to cause storage of an amount of thermal energy in the thermal energy storage system at the end of a period of insolation which is sufficient to satisfy the scheduled demand for electrical power to be generated during the next period of eclipse. The control system is based upon Kalman filter theory.

  14. The water footprint of energy consumption: an assessment of water requirements of primary energy carriers

    NARCIS (Netherlands)

    Gerbens-Leenes, P.W.; Hoekstra, A.Y.; Van der Meer, T.H.

    2007-01-01

    Gerbens-Leenes, P.W., Hoekstra, A.Y., Van der Meer, T.H., 2007. The water footprint of energy consumption: an assessment of water requirements of primary energy carriers. In: proceedings ‘First World Water Sustainability-Renewable Energy Congress and Exhibition’. 25-28 November 2007, Maastricht, the

  15. Thermal energy management process experiment

    Science.gov (United States)

    Ollendorf, S.

    1984-01-01

    The thermal energy management processes experiment (TEMP) will demonstrate that through the use of two-phase flow technology, thermal systems can be significantly enhanced by increasing heat transport capabilities at reduced power consumption while operating within narrow temperature limits. It has been noted that such phenomena as excess fluid puddling, priming, stratification, and surface tension effects all tend to mask the performance of two-phase flow systems in a 1-g field. The flight experiment approach would be to attack the experiment to an appropriate mounting surface with a 15 to 20 meter effective length and provide a heat input and output station in the form of heaters and a radiator. Using environmental data, the size, location, and orientation of the experiment can be optimized. The approach would be to provide a self-contained panel and mount it to the STEP through a frame. A small electronics package would be developed to interface with the STEP avionics for command and data handling. During the flight, heaters on the evaporator will be exercised to determine performance. Flight data will be evaluated against the ground tests to determine any anomalous behavior.

  16. Solar energy thermalization and storage device

    Science.gov (United States)

    McClelland, J.F.

    A passive solar thermalization and thermal energy storage assembly which is visually transparent is described. The assembly consists of two substantial parallel, transparent wall members mounted in a rectangular support frame to form a liquid-tight chamber. A semitransparent thermalization plate is located in the chamber, substantially paralled to and about equidistant from the transparent wall members to thermalize solar radiation which is stored in a transparent thermal energy storage liquid which fills the chamber. A number of the devices, as modules, can be stacked together to construct a visually transparent, thermal storage wall for passive solar-heated buildings.

  17. Thermal energy storage for cogeneration applications

    Energy Technology Data Exchange (ETDEWEB)

    Drost, M.K.; Antoniak, Z.I.

    1992-04-01

    Cogeneration is playing an increasingly important role in providing energy efficient power generation and thermal energy for space heating and industrial process heat applications. However, the range of applications for cogeneration could be further increased if the generation of electricity could be coupled from the generation of process heat. Thermal energy storage (TES) can decouple power generation from the production of process heat, allowing the production of dispatchable power while fully utilizing the thermal energy available from the prime mover. The Pacific Northwest Laboratory (PNL) leads the US Department of Energy`s Thermal Energy Storage Program. The program focuses on developing TES for daily cycling (diurnal storage), annual cycling (seasonal storage), and utility applications (utility thermal energy storage (UTES)). Several of these technologies can be used in a cogeneration facility. This paper discusses TES concepts relevant to cogeneration and describes the current status of these TES systems.

  18. The prospects for hydrogen as an energy carrier: an overview of hydrogen energy and hydrogen energy systems

    International Nuclear Information System (INIS)

    Rosen, Marc A.; Koohi-Fayegh, Seama

    2016-01-01

    Hydrogen is expected to play a key role as an energy carrier in future energy systems of the world. As fossil-fuel supplies become scarcer and environmental concerns increase, hydrogen is likely to become an increasingly important chemical energy carrier and eventually may become the principal chemical energy carrier. When most of the world's energy sources become non-fossil based, hydrogen and electricity are expected to be the two dominant energy carriers for the provision of end-use services. In such a ''hydrogen economy,'' the two complementary energy carriers, hydrogen and electricity, are used to satisfy most of the requirements of energy consumers. A transition era will bridge the gap between today's fossil-fuel economy and a hydrogen economy, in which non-fossil-derived hydrogen will be used to extend the lifetime of the world's fossil fuels - by upgrading heavy oils, for instance - and the infrastructure needed to support a hydrogen economy is gradually developed. In this paper, the role of hydrogen as an energy carrier and hydrogen energy systems' technologies and their economics are described. Also, the social and political implications of hydrogen energy are examined, and the questions of when and where hydrogen is likely to become important are addressed. Examples are provided to illustrate key points. (orig.)

  19. Carrier-carrier relaxation kinetics in quantum well semiconductor structures with nonparabolic energy bands

    DEFF Research Database (Denmark)

    Dery, H.; Tromborg, Bjarne; Eisenstein, G.

    2003-01-01

    We describe carrier-carrier scattering dynamics in an inverted quantum well structure including the nonparabolic nature of the valance band. A solution of the semiconductor Bloch equations yields strong evidence to a large change in the temporal evolution of the carrier distributions compared...

  20. Thermal energy storage for cogeneration applications

    Energy Technology Data Exchange (ETDEWEB)

    Drost, M.K.; Antoniak, Z.I.

    1992-04-01

    Cogeneration is playing an increasingly important role in providing energy efficient power generation and thermal energy for space heating and industrial process heat applications. However, the range of applications for cogeneration could be further increased if the generation of electricity could be coupled from the generation of process heat. Thermal energy storage (TES) can decouple power generation from the production of process heat, allowing the production of dispatchable power while fully utilizing the thermal energy available from the prime mover. The Pacific Northwest Laboratory (PNL) leads the US Department of Energy's Thermal Energy Storage Program. The program focuses on developing TES for daily cycling (diurnal storage), annual cycling (seasonal storage), and utility applications (utility thermal energy storage (UTES)). Several of these technologies can be used in a cogeneration facility. This paper discusses TES concepts relevant to cogeneration and describes the current status of these TES systems.

  1. Thermal energy storage apparatus, controllers and thermal energy storage control methods

    Science.gov (United States)

    Hammerstrom, Donald J.

    2016-05-03

    Thermal energy storage apparatus, controllers and thermal energy storage control methods are described. According to one aspect, a thermal energy storage apparatus controller includes processing circuitry configured to access first information which is indicative of surpluses and deficiencies of electrical energy upon an electrical power system at a plurality of moments in time, access second information which is indicative of temperature of a thermal energy storage medium at a plurality of moments in time, and use the first and second information to control an amount of electrical energy which is utilized by a heating element to heat the thermal energy storage medium at a plurality of moments in time.

  2. Thermal modeling and optimization of a thermally matched energy harvester

    Science.gov (United States)

    Boughaleb, J.; Arnaud, A.; Cottinet, P. J.; Monfray, S.; Gelenne, P.; Kermel, P.; Quenard, S.; Boeuf, F.; Guyomar, D.; Skotnicki, T.

    2015-08-01

    The interest in energy harvesting devices has grown with the development of wireless sensors requiring small amounts of energy to function. The present article addresses the thermal investigation of a coupled piezoelectric and bimetal-based heat engine. The thermal energy harvester in question converts low-grade heat flows into electrical charges by achieving a two-step conversion mechanism for which the key point is the ability to maintain a significant thermal gradient without any heat sink. Many studies have previously focused on the electrical properties of this innovative device for energy harvesting but until now, no thermal modeling has been able to describe the device specificities or improve its thermal performances. The research reported in this paper focuses on the modeling of the harvester using an equivalent electrical circuit approach. It is shown that the knowledge of the thermal properties inside the device and a good comprehension of its heat exchange with the surrounding play a key role in the optimization procedure. To validate the thermal modeling, finite element analyses as well as experimental measurements on a hot plate were carried out and the techniques were compared. The proposed model provided a practical guideline for improving the generator design to obtain a thermally matched energy harvester that can function over a wide range of hot source temperatures for the same bimetal. A direct application of this study has been implemented on scaled structures to maintain an important temperature difference between the cold surface and the hot reservoir. Using the equations of the thermal model, predictions of the thermal properties were evaluated depending on the scaling factor and solutions for future thermal improvements are presented.

  3. 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

  4. Thermal Energy Conversion in Nanofluids

    Science.gov (United States)

    Taylor, Robert

    2011-12-01

    A relatively simple subset of nanotechnology---nanofluids---can be obtained by adding nanoparticles to conventional base fluids. The promise of these fluids stems from the fact that relatively low particle loadings (typically surface-based absorption. Depending on the particle material, size, shape, and volume fraction, a fluid can be changed from being mostly transparent to sunlight (in the case of water, alcohols, oils, and glycols) to being a very efficient volumetric absorber of sunlight. This research also visualizes, under high levels of irradiation, how nanofluids undergo interesting, localized phase change phenomena. For this, images were taken of bubble formation and boiling in aqueous nanofluids heated by a hot wire and by a laser. Infrared thermography was also used to quantify this phenomenon. Overall, though, this research reveals the possibility for novel solar collectors in which the working fluid directly absorbs light energy and undergoes phase change in a single step. Modeling results indicate that these improvements can increase a solar thermal receiver's efficiency by up to 10%.

  5. Thermal energy systems design and analysis

    CERN Document Server

    Penoncello, Steven G

    2015-01-01

    IntroductionThermal Energy Systems Design and AnalysisSoftwareThermal Energy System TopicsUnits and Unit SystemsThermophysical PropertiesEngineering DesignEngineering EconomicsIntroductionCommon Engineering Economics NomenclatureEconomic Analysis Tool: The Cash Flow DiagramTime Value of MoneyTime Value of Money ExamplesUsing Software to Calculate Interest FactorsEconomic Decision MakingDepreciation and TaxesProblemsAnalysis of Thermal Energy SystemsIntroductionNomenclatureThermophysical Properties of SubstancesSuggested Thermal Energy Systems Analysis ProcedureConserved and Balanced QuantitiesConservation of MassConservation of Energy (The First Law of Thermodynamics)Entropy Balance (The Second Law of Thermodynamics)Exergy Balance: The Combined LawEnergy and Exergy Analysis of Thermal Energy CyclesDetailed Analysis of Thermal Energy CyclesProblemsFluid Transport in Thermal Energy SystemsIntroductionPiping and Tubing StandardsFluid Flow FundamentalsValves and FittingsDesign and Analysis of Pipe NetworksEconomi...

  6. Utilisation of biomass for the supply of energy carriers

    Energy Technology Data Exchange (ETDEWEB)

    Claassen, P.A.M.; Lopez Contreras, A.M.; Sijtsma, L.; Weusthuis, R.A. [Institute of Agrotechnological Research (ATO-DLO), Wageningen (NL). Industrial (Agro) biotechnology Subdiv.; Lier, J.B. van [Wageningen Agricultural Univ. (WAU) (Netherlands). Environmental Technology Subdept.; Niel, E.W.J. van; Stams, A.J.M. [Wageningen Agricultural Univ. (WAU) (Netherlands). Environmental Technology Subdiv.; Vries, S.S. de [Development of Bioethanol from Agricultural Resources (OBL), The Hague (Netherlands)

    1999-07-01

    Because biomass is a widely available, renewable resource, its utilisation for the production of energy has great potential for reducing CO{sub 2} emissions and thereby preventing global warming. In this mini-review the 'state of the art' of several fermentation processes is discussed, starting with the most advanced process of ethanol production. This is followed by methane production, an established process for waste water purification which is gaining more attention because of the inherent energy production. Subsequently ABE fermentation is discussed and finally the biological production of hydrogen. The last section proposes a new way to assess and compare the different processes by relating their merit to 'work content' values and 'lost work' instead of the combustion values of their products. It is argued that, especially when dealing with energy from biomass, the application of this methodology will provide a uniform valuation for different processes and products. The described fermentation processes enable the supply of pure energy carriers, either gaseous or liquid, from biomass, yet the introduction of these processes is hampered by two major problems. The first is related to technological shortcomings in the mobilisation of fermentable components from the biomass. The second, having a much greater impact, is linked with socio-economics: until full externality costs are attributed to fossil fuels, accounting for their role in pollution and global warming, the competitiveness of the processes described here will hardly stand a chance. (orig.)

  7. A hybrid solar and chemical looping combustion system for solar thermal energy storage

    International Nuclear Information System (INIS)

    Jafarian, Mehdi; Arjomandi, Maziar; Nathan, Graham J.

    2013-01-01

    Highlights: ► A novel solar–CLC hybrid system is proposed which integrates a CLC with solar thermal energy. ► The oxygen carrier particles are used as storage medium for thermal energy storage. ► A solar cavity reactor is proposed for fuel reactor. ► The absorbed solar energy is stored in the particles to produce a base heat load. -- Abstract: A novel hybrid of a solar thermal energy and a chemical looping combustion (CLC) system is proposed here, which employs the oxygen carrier particles in a CLC system to provide diurnal thermal energy storage for concentrated solar thermal energy. In taking advantage of the chemical and sensible energy storage systems that are an inherent part of a CLC system, this hybrid offers potential to achieve cost effective, base load power generation for solar energy. In the proposed system, three reservoirs have been added to a conventional CLC system to allow storage of the oxygen carrier particles, while a cavity solar receiver has been chosen for the fuel reactor. The performance of the system is evaluated using ASPEN PLUS software, with the model being validated using independent simulation result reported previously. Operating temperature, solar efficiency, solar fraction, exergy efficiency and the fraction of the solar thermal energy stored for a based load power generation application are reported.

  8. Ultrahigh energy gamma rays: carriers of cosmological information

    International Nuclear Information System (INIS)

    Aharonian, F.A.; Atoyan, A.M.

    1985-01-01

    Observational data being the basis of contemporary cosmological models are not numerous: Hubble law of redshift for galaxies, element abundances, and observation of cosmic microwave background radiation (MBR). The significance of MBR discovery predicted in the Big-Band model is particularly stressed. Radio astronomical measurements give an information on MBR only near the Earth. Experimental confirmation of evolution of MBR, i.e., its probing in remote epochs, might obviously present a direct verification of the hypothesis of hot expanding Universe. The carriers of similar cosmological information should be particles which, firstly, effectively interact with MBR, and secondly, make it possible to identify unambiguously the epoch of interaction. A possibility to verify a number of cosmological hypotheses by searching the cutoffs in spectra of ultrahigh energy gamma-rays (UHEGR) from extragalactic sources is discussed

  9. Thermal energy accumulators. A bibliographical study

    International Nuclear Information System (INIS)

    Charlety, Paul

    1971-01-01

    Energy storage is a challenge, notably for spacecraft, submarines and non-polluting automotive vehicles. After a comparison of mass energies of different principles of energy accumulation (magnetic, electrostatic, solid elasticity, kinetic energy, gaseous elasticity, electro-chemistry, sensitive heat, freezing heat, fuels, radioactivity, nuclear fission or fusion, mass energy), the author discusses the choice of thermal storage, presents the main bodies used for thermal energy accumulation (molten salts such as lithium hydride or lithium salt eutectics, or other compounds such as alumina, paraffins), and gives an overview of the main theoretical problems [fr

  10. Comparative study of hydrogen and methanol as energy carriers

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, Anna

    1998-06-01

    This report has been written with the purpose to compare hydrogen and methanol, with gasoline, as energy carriers for new energy systems in the future. This energy system must satisfy the demands for sustainable development. The report focuses on motor vehicle applications. A few different criteria has been developed to help form the characterisation method. The criteria proposed in this thesis are developed for an environmental comparison mainly based on emissions from combustion. The criteria concerns the following areas: Renewable resources, The ozone layer, The greenhouse effect, The acidification, and Toxic substances. In many ways, hydrogen may seem as a very good alternative compared with gasoline and diesel oil. Combustion of hydrogen in air results in water and small amounts of oxides of nitrogen. In this report, hydrogen produced from renewable resources is investigated. This is necessary to fulfill the demands for sustainable development. Today, however, steam reforming of fossil fuels represent 99% of the hydrogen production market. Problem areas connected with hydrogen use are for instance storage and distribution. Methanol has many advantages, while comparing methanol and gasoline, like lower emissions of nitrogen oxides and hydrocarbons, limited emissions of carbon dioxide and no sulphur content. Methanol can be produced from many different resources, for example natural gas, naphtha, oil, coal or peat, and biomass. To meet demands for sustainable production, methanol has to be produced from biomass Examination paper. 32 refs, 20 figs, 13 tabs

  11. Hybrid energy harvesting using active thermal backplane

    Science.gov (United States)

    Kim, Hyun-Wook; Lee, Dong-Gun

    2016-04-01

    In this study, we demonstrate the concept of a new hybrid energy harvesting system by combing solar cells with magneto-thermoelectric generator (MTG, i.e., thermal energy harvesting). The silicon solar cell can easily reach high temperature under normal operating conditions. Thus the heated solar cell becomes rapidly less efficient as the temperature of solar cell rises. To increase the efficiency of the solar cell, air or water-based cooling system is used. To surpass conventional cooling devices requiring additional power as well as large working space for air/water collectors, we develop a new technology of pairing an active thermal backplane (ATB) to solar cell. The ATB design is based on MTG technology utilizing the physics of the 2nd order phase transition of active ferromagnetic materials. The MTG is cost-effective conversion of thermal energy to electrical energy and is fundamentally different from Seebeck TEG devices. The ATB (MTG) is in addition to being an energy conversion system, a very good conveyor of heat through both conduction and convection. Therefore, the ATB can provide dual-mode for the proposed hybrid energy harvesting. One is active convective and conductive cooling for heated solar cell. Another is active thermal energy harvesting from heat of solar cell. These novel hybrid energy harvesting device have potentially simultaneous energy conversion capability of solar and thermal energy into electricity. The results presented can be used for better understanding of hybrid energy harvesting system that can be integrated into commercial applications.

  12. TES (Thermal Energy Storage) Video News Release

    Science.gov (United States)

    1994-01-01

    TES is an in-space technology experiment that flew on STS-62. Its intent is to investigate the behavior of two different thermal energy storage materials as they undergo repeated melting and freezing in the microgravity environment.

  13. Advances in solar thermal energy in Uruguay

    International Nuclear Information System (INIS)

    Franco Noceto, P.

    2012-01-01

    This article is about the law 18585 which declared de solar thermal energy as national interest. This law establishes the obligation to incorporate solar heating systems in health care centers, hotels and sports clubs.

  14. Energy efficient thermal management of data centers

    CERN Document Server

    Kumar, Pramod

    2012-01-01

    Energy Efficient Thermal Management of Data Centers examines energy flow in today's data centers. Particular focus is given to the state-of-the-art thermal management and thermal design approaches now being implemented across the multiple length scales involved. The impact of future trends in information technology hardware, and emerging software paradigms such as cloud computing and virtualization, on thermal management are also addressed. The book explores computational and experimental characterization approaches for determining temperature and air flow patterns within data centers. Thermodynamic analyses using the second law to improve energy efficiency are introduced and used in proposing improvements in cooling methodologies. Reduced-order modeling and robust multi-objective design of next generation data centers are discussed. This book also: Provides in-depth treatment of energy efficiency ideas based on  fundamental heat transfer, fluid mechanics, thermodynamics, controls, and computer science Focus...

  15. COSTS OF THERMAL ENERGY STORAGE TECHNOLOGIES

    OpenAIRE

    Bravo Hidalgo. Debrayan

    2017-01-01

    Thermal accumulation facilities allow energy to be available in the absence of sunlight. This fact reduces the difficulty of the intermittence in the incidence of the king star in our planet. Thermal accumulation technology also contributes to smooth the fluctuations in energy demand during different times of the day. This contribution identifies the nations with the most favorable research results in this area; as well as the main research lines that are being developed today. A compendium o...

  16. Integration of thermal energy and seawater desalination

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Runya; Lin, Hu [Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100080 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Xie, Lixin; Liu, Jie [School of Chemical Engineering and technology, Tianjin University, Tianjin 300072 (China); Han, Wei [Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100080 (China)

    2010-11-15

    Energy and freshwater shortage are the bottlenecks restricting China's economic development. The integration of energy utilization system and seawater desalination is considered as an innovative technology enabling efficient simultaneous use of middle or low temperature thermal energy and supply freshwater. Three feasible approaches to integrate seawater desalination with energy utilization system are presented in this paper, including combinations of the desalination process with a Combined Cooling Heating and Power system (CCHP), a power plant, or a solar thermal utilization system. In addition, the feasibility and advantages of a seawater desalination system combined with a power plant are described. The findings indicate that combining seawater desalination with industrial processes is a feasible and promising way to solve the problems of the lack of freshwater and low efficient use of low temperature thermal energy in coastland areas. (author)

  17. COSTS OF THERMAL ENERGY STORAGE TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    Debrayan Bravo Hidalgo

    2017-10-01

    Full Text Available Thermal accumulation facilities allow energy to be available in the absence of sunlight. This fact reduces the difficulty of the intermittence in the incidence of the king star in our planet. Thermal accumulation technology also contributes to smooth the fluctuations in energy demand during different times of the day. This contribution identifies the nations with the most favorable research results in this area; as well as the main research lines that are being developed today. A compendium of various thermal energy storage materials, their current costs per unit mass, and their physical properties are presented. Techniques for implementing thermal accumulation technologies can be classified as areas of high, medium and low temperature. In the high temperature area, inorganic materials such as nitrate salts are the most widely used thermal energy storage materials, while in the medium and lower temperature areas; organic materials such as commercial paraffin are more common. Currently, one of the research trends in this area are the projects aimed at optimizing the chemical and physical characteristics of thermal storage materials, because the success of any thermos-energetic storage technology has a strong dependence on the cost of the materials selected for thermal storage.

  18. Graphene Thermal Properties: Applications in Thermal Management and Energy Storage

    Directory of Open Access Journals (Sweden)

    Jackie D. Renteria

    2014-11-01

    Full Text Available We review the thermal properties of graphene, few-layer graphene and graphene nanoribbons, and discuss practical applications of graphene in thermal management and energy storage. The first part of the review describes the state-of-the-art in the graphene thermal field focusing on recently reported experimental and theoretical data for heat conduction in graphene and graphene nanoribbons. The effects of the sample size, shape, quality, strain distribution, isotope composition, and point-defect concentration are included in the summary. The second part of the review outlines thermal properties of graphene-enhanced phase change materials used in energy storage. It is shown that the use of liquid-phase-exfoliated graphene as filler material in phase change materials is promising for thermal management of high-power-density battery parks. The reported experimental and modeling results indicate that graphene has the potential to outperform metal nanoparticles, carbon nanotubes, and other carbon allotropes as filler in thermal management materials.

  19. Thermal generation and mobility of charge carriers in collective proton transport in hydrogen-bonded chains

    Energy Technology Data Exchange (ETDEWEB)

    Peyrard, M.; Boesch, R.; Kourakis, I. (Dijon Univ., 21 (France). Faculte des Sciences)

    1991-01-01

    The transport of protons in hydrogen-bonded systems is a long standing problem which has not yet obtained a satisfactorily theoretical description. Although this problem was examined first for ice, it is relevant in many systems and in particular in biology for the transport along proteins or for proton conductance across membranes, an essential process in cell life. The broad relevance makes the study of proton conduction very appealing. Since the original work of Bernal and Fowler on ice, the idea that the transport occurs through chains of hydrogen bonds has been well accepted. Such proton wires'' were invoked by Nagle and Morowitz for proton transport across membranes proteins and more recently across lipid bilayers. In this report, we assume the existence of such an hydrogen-bonded chain and discuss its consequences on the dynamics of the charge carriers. We show that this assumption leads naturally to the idea of soliton transport and we put a special emphasis on the role of the coupling between the protons and heavy ions motions. The model is presented. We show how the coupling affects strongly the dynamics of the charge carriers and we discuss the role it plays in the thermal generation of carriers. The work presented has been performed in 1986 and 87 with St. Pnevmatikos and N. Flyzanis and was then completed in collaboration with D. Hochstrasser and H. Buettner. Therefore the results presented in this part are not new but we think that they are appropriate in the context of this multidisciplinary workshop because they provide a rather complete example of the soliton picture for proton conduction. This paper discusses the thermal generation of the charge carriers when the coupling between the protons and heavy ions dynamics is taken into account. The results presented in this part are very recent and will deserve further analysis but they already show that the coupling can assist for the formation of the charge carriers.

  20. Thermal Energy Storage Flight Experiment in Microgravity

    Science.gov (United States)

    Namkoong, David

    1992-01-01

    The Thermal Energy Storage Flight Experiment was designed to characterize void shape and location in LiF-based phase change materials in different energy storage configurations representative of advanced solar dynamic systems. Experiment goals and payload design are described in outline and graphic form.

  1. Romania needs a strategy for thermal energy

    Directory of Open Access Journals (Sweden)

    Leca Aureliu

    2015-06-01

    Full Text Available The energy sector in Romania consists of three sub-sectors: electricity, natural gas and heat. Among these, the sub-sector of thermal energy is in the most precarious situation because it has been neglected for a long time. This sub-sector is particularly important both due to the amount of final heat consumption (of over 50% of final energy consumption, and to the fact that it has a direct negative effect on the population, industry and services. This paper presents the main directions for developing a modern strategy of the thermal energy sub-sector, which would fit into Romania’s Energy Strategy that is still in preparation This is based on the author’s 50 years of experience in this field that includes knowledge about the processes and the equipment of thermal energy, expertise in the management and restructuring of energy companies and also knowledge of the specific legislation. It is therefore recommended, following the European regulations and practices, the promotion and upgrading of district heating systems using efficient cogeneration, using trigeneration in Romania, modernizing buildings in terms of energy use, using of renewable energy sources for heating, especially biomass, and modernizing the energy consumption of rural settlements.

  2. Thermal power plant efficiency enhancement with Ocean Thermal Energy Conversion

    International Nuclear Information System (INIS)

    Soto, Rodrigo; Vergara, Julio

    2014-01-01

    In addition to greenhouse gas emissions, coastal thermal power plants would gain further opposition due to their heat rejection distressing the local ecosystem. Therefore, these plants need to enhance their thermal efficiency while reducing their environmental offense. In this study, a hybrid plant based on the principle of Ocean Thermal Energy Conversion was coupled to a 740 MW coal-fired power plant project located at latitude 28°S where the surface to deepwater temperature difference would not suffice for regular OTEC plants. This paper presents the thermodynamical model to assess the overall efficiency gained by adopting an ammonia Rankine cycle plus a desalinating unit, heated by the power plant condenser discharge and refrigerated by cold deep seawater. The simulation allowed us to optimize a system that would finally enhance the plant power output by 25–37 MW, depending on the season, without added emissions while reducing dramatically the water temperature at discharge and also desalinating up to 5.8 million tons per year. The supplemental equipment was sized and the specific emissions reduction was estimated. We believe that this approach would improve the acceptability of thermal and nuclear power plant projects regardless of the plant location. -- Highlights: • An Ocean Thermal Energy Conversion hybrid plant was designed. • The waste heat of a power plant was delivered as an OTEC heat source. • The effect of size and operating conditions on plant efficiency were studied. • The OTEC implementation in a Chilean thermal power plant was evaluated. • The net efficiency of the thermal power plant was increased by 1.3%

  3. Phase-Change Thermal Energy Storage

    Science.gov (United States)

    1989-11-01

    The goal of this program is to advance the engineering and scientific understanding of solar thermal technology and to establish the technology base from which private industry can develop solar thermal power production options for introduction into the competitive energy market. Solar thermal technology concentrates the solar flux using tracking mirrors or lenses onto a receiver where the solar energy is absorbed as heat and converted into electricity or incorporated into products as process heat. The two primary solar thermal technologies, central receivers and distributed receivers, employ various point and line-focus optics to concentrate sunlight. Current central receiver systems use fields of heliostats (two-axes tracking mirrors) to focus the sun's radiant energy onto a single, tower-mounted receiver. Point focus concentrators up to 17 meters in diameter track the sun in two axes and use parabolic dish mirrors or Fresnel lenses to focus radiant energy onto a receiver. Troughs and bowls are line-focus tracking reflectors that concentrate sunlight onto receiver tubes along their focal lines. Concentrating collector modules can be used alone or in a multimodule system. The concentrated radiant energy absorbed by the solar thermal receiver is transported to the conversion process by a circulating working fluid. Receiver temperatures range from 100 C in low-temperature troughs to over 1500 C in dish and central receiver systems.

  4. Improvement of Aspergillus flavus saponin hydrolase thermal stability and productivity via immobilization on a novel carrier based on sugarcane bagasse

    Directory of Open Access Journals (Sweden)

    Hala A. Amin

    2018-03-01

    Full Text Available Soyasapogenol B (SB is known to have many biological activities such as hepatoprotective, anti-inflammatory, anti-mutagenic, antiviral and anticancer activities. Enzymatic conversion of soyasaponins to SB was carried out using saponin hydrolase (SH extracted from Aspergillus flavus. The partially purified enzyme was immobilized on different carriers by physical adsorption, covalent binding or entrapment. Among the investigated carriers, Eupergit C and sugarcane bagasse (SCB activated by DIC and NHS were the most suitable two carriers for immobilization (the immobilized forms recovered 46.5 and 37.1% of the loaded enzyme activity, respectively. Under optimized immobilization conditions, immobilized SH on Eupergit C and on activated SBC recovered 87.7 and 83.3% of its original activity, respectively. Compared to free SH, immobilized SH on Eupergit C and on activated SCB showed higher optimum pH, activation energy, half-lives and lower deactivation constant rate. Also, their SB productivities were improved by 2.3- and 2.2-folds compared to free SH (87.7 and 83.3 vs. 37.5%, respectively. Hence, being SCB more sustainable and an inexpensive material, it can be considered a good alternative to Eupergit C as a support for SH immobilization. SH immobilization on industrially applicable and inexpensive carrier is necessary to improve SB yield and reduce its production cost. The chemical structure of SCB and the resulting cellulose derivatives were studied by ATR-IR spectroscopy. The thermal analysis technique was used to study the chemical treatment of SCB and coupling with the enzyme. This technique confirmed the removal of lignin and hemicellulose by chemical treatment of SCB.

  5. 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.

  6. Spatial distribution of thermal energy in equilibrium.

    Science.gov (United States)

    Bar-Sinai, Yohai; Bouchbinder, Eran

    2015-06-01

    The equipartition theorem states that in equilibrium, thermal energy is equally distributed among uncoupled degrees of freedom that appear quadratically in the system's Hamiltonian. However, for spatially coupled degrees of freedom, such as interacting particles, one may speculate that the spatial distribution of thermal energy may differ from the value predicted by equipartition, possibly quite substantially in strongly inhomogeneous or disordered systems. Here we show that for systems undergoing simple Gaussian fluctuations around an equilibrium state, the spatial distribution is universally bounded from above by 1/2k(B)T. We further show that in one-dimensional systems with short-range interactions, the thermal energy is equally partitioned even for coupled degrees of freedom in the thermodynamic limit and that in higher dimensions nontrivial spatial distributions emerge. Some implications are discussed.

  7. Modeling energy flexibility of low energy buildings utilizing thermal mass

    DEFF Research Database (Denmark)

    Foteinaki, Kyriaki; Heller, Alfred; Rode, Carsten

    2016-01-01

    to match the production patterns, shifting demand from on-peak hours to off-peak hours. Buildings could act as flexibility suppliers to the energy system, through load shifting potential, provided that the large thermal mass of the building stock could be utilized for energy storage. In the present study......In the future energy system a considerable increase in the penetration of renewable energy is expected, challenging the stability of the system, as both production and consumption will have fluctuating patterns. Hence, the concept of energy flexibility will be necessary in order for the consumption...... the load shifting potential of an apartment of a low energy building in Copenhagen is assessed, utilizing the heat storage capacity of the thermal mass when the heating system is switched off for relieving the energy system. It is shown that when using a 4-hour preheating period before switching off...

  8. Thermal energy recycling fuel cell arrangement

    Science.gov (United States)

    Hanrahan, Paul R.

    2017-04-11

    An example fuel cell arrangement includes a fuel cell stack configured to receive a supply fluid and to provide an exhaust fluid that has more thermal energy than the supply fluid. The arrangement also includes an ejector and a heat exchanger. The ejector is configured to direct at least some of the exhaust fluid into the supply fluid. The heat exchanger is configured to increase thermal energy in the supply fluid using at least some of the exhaust fluid that was not directed into the supply fluid.

  9. Aquifer thermal energy (heat and chill) storage

    Energy Technology Data Exchange (ETDEWEB)

    Jenne, E.A. (ed.)

    1992-11-01

    As part of the 1992 Intersociety Conversion Engineering Conference, held in San Diego, California, August 3--7, 1992, the Seasonal Thermal Energy Storage Program coordinated five sessions dealing specifically with aquifer thermal energy storage technologies (ATES). Researchers from Sweden, The Netherlands, Germany, Switzerland, Denmark, Canada, and the United States presented papers on a variety of ATES related topics. With special permission from the Society of Automotive Engineers, host society for the 1992 IECEC, these papers are being republished here as a standalone summary of ATES technology status. Individual papers are indexed separately.

  10. LiH thermal energy storage device

    Science.gov (United States)

    Olszewski, M.; Morris, D.G.

    1994-06-28

    A thermal energy storage device for use in a pulsed power supply to store waste heat produced in a high-power burst operation utilizes lithium hydride as the phase change thermal energy storage material. The device includes an outer container encapsulating the lithium hydride and an inner container supporting a hydrogen sorbing sponge material such as activated carbon. The inner container is in communication with the interior of the outer container to receive hydrogen dissociated from the lithium hydride at elevated temperatures. 5 figures.

  11. Red-shifted carrier multiplication energy threshold and exciton recycling mechanisms in strongly interacting silicon nanocrystals.

    Science.gov (United States)

    Marri, Ivan; Govoni, Marco; Ossicini, Stefano

    2014-09-24

    We present density functional theory calculations of carrier multiplication properties in a system of strongly coupled silicon nanocrystals. Our results suggest that nanocrystal-nanocrystal interaction can lead to a reduction of the carrier multiplication energy threshold without altering the carrier multiplication efficiency at high energies, in agreement with experiments. The time evolution of the number of electron-hole pairs generated in a system of strongly interacting nanocrystals upon absorption of high-energy photons is analyzed by solving a system of coupled rate equations, where exciton recycling mechanisms are implemented. We reconsider the role played by Auger recombination which is here accounted also as an active, nondetrimental process.

  12. Aquifer thermal energy storage. International symposium: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-05-01

    Aquifers have been used to store large quantities of thermal energy to supply process cooling, space cooling, space heating, and ventilation air preheating, and can be used with or without heat pumps. Aquifers are used as energy sinks and sources when supply and demand for energy do not coincide. Aquifer thermal energy storage may be used on a short-term or long-term basis; as the sole source of energy or as a partial storage; at a temperature useful for direct application or needing upgrade. The sources of energy used for aquifer storage are ambient air, usually cold winter air; waste or by-product energy; and renewable energy such as solar. The present technical, financial and environmental status of ATES is promising. Numerous projects are operating and under development in several countries. These projects are listed and results from Canada and elsewhere are used to illustrate the present status of ATES. Technical obstacles have been addressed and have largely been overcome. Cold storage in aquifers can be seen as a standard design option in the near future as it presently is in some countries. The cost-effectiveness of aquifer thermal energy storage is based on the capital cost avoidance of conventional chilling equipment and energy savings. ATES is one of many developments in energy efficient building technology and its success depends on relating it to important building market and environmental trends. This paper attempts to provide guidance for the future implementation of ATES. Individual projects have been processed separately for entry onto the Department of Energy databases.

  13. Density Functional Theory Calculations of Activation Energies for Carrier Capture by Defects in Semiconductors

    Science.gov (United States)

    Modine, N. A.; Wright, A. F.; Lee, S. R.

    The rate of defect-induced carrier recombination is determined by both defect levels and carrier capture cross-sections. Density functional theory (DFT) has been widely and successfully used to predict defect levels, but only recently has work begun to focus on using DFT to determine carrier capture cross-sections. Lang and Henry developed the theory of carrier-capture by multiphonon emission in the 1970s and showed that carrier-capture cross-sections differ between defects primarily due to differences in their carrier capture activation energies. We present an approach to using DFT to calculate carrier capture activation energies that does not depend on an assumed configuration coordinate and that fully accounts for anharmonic effects, which can substantially modify carrier activation energies. We demonstrate our approach for intrinisic defects in GaAs and GaN and discuss how our results depend on the choice of exchange-correlation functional and the treatment of spin polarization. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000.

  14. Carrier multiplication in semiconductor nanocrystals detected by energy transfer to organic dye molecules.

    Science.gov (United States)

    Xiao, Jun; Wang, Ying; Hua, Zheng; Wang, Xiaoyong; Zhang, Chunfeng; Xiao, Min

    2012-01-01

    Carrier multiplication describes an interesting optical phenomenon in semiconductors whereby more than one electron-hole pair, or exciton, can be simultaneously generated upon absorption of a single high-energy photon. So far, it has been highly debated whether the carrier multiplication efficiency is enhanced in semiconductor nanocrystals as compared with their bulk counterpart. The controversy arises from the fact that the ultrafast optical methods currently used need to correctly account for the false contribution of charged excitons to the carrier multiplication signals. Here we show that this charged exciton issue can be resolved in an energy transfer system, where biexcitons generated in the donor nanocrystals are transferred to the acceptor dyes, leading to an enhanced fluorescence from the latter. With the biexciton Auger and energy transfer lifetime measurements, an average carrier multiplication efficiency of ~17.1% can be roughly estimated in CdSe nanocrystals when the excitation photon energy is ~2.46 times of their energy gap.

  15. Ocean Thermal Energy Conversion: An overview

    Energy Technology Data Exchange (ETDEWEB)

    1989-11-01

    Ocean thermal energy conversion, or OTEC is a technology that extracts power from the ocean's natural thermal gradient. This technology is being pursued by researchers from many nations; in the United States, OTEC research is funded by the US Department of Energy's Ocean Energy Technology program. The program's goal is to develop the technology so that industry can make a competent assessment of its potential -- either as an alternative or as a supplement to conventional energy sources. Federally funded research in components and systems will help OTEC to the threshold of commercialization. This publication provides an overview of the OTEC technology. 47 refs., 25 figs.

  16. Thermal Insulation Strips Conserve Energy

    Science.gov (United States)

    2009-01-01

    Launching the space shuttle involves an interesting paradox: While the temperatures inside the shuttle s main engines climb higher than 6,000 F hot enough to boil iron for fuel, the engines use liquid hydrogen, the second coldest liquid on Earth after liquid helium. Maintained below 20 K (-423 F), the liquid hydrogen is contained in the shuttle s rust-colored external tank. The external tank also contains liquid oxygen (kept below a somewhat less chilly 90 K or -297 F) that combines with the hydrogen to create an explosive mixture that along with the shuttle s two, powdered aluminum-fueled solid rocket boosters allows the shuttle to escape Earth s gravity. The cryogenic temperatures of the main engines liquid fuel can cause ice, frost, or liquefied air to build up on the external tank and other parts of the numerous launch fueling systems, posing a possible debris risk when the ice breaks off during launch and causing difficulties in the transfer and control of these cryogenic liquid propellants. Keeping the fuel at the necessary ultra-cold temperatures while minimizing ice buildup and other safety hazards, as well as reducing the operational maintenance costs, has required NASA to explore innovative ways for providing superior thermal insulation systems. To address the challenge, the Agency turned to an insulating technology so effective that, even though it is mostly air, a thin sheet can prevent a blowtorch from igniting a match. Aerogels were invented in 1931 and demonstrate properties that make them the most extraordinary insulating materials known; a 1-inch-thick piece of aerogel provides the same insulation as layering 15 panes of glass with air pockets in between. Derived from silica, aluminum oxide, or carbon gels using a supercritical drying process - resulting in a composition of almost 99-percent air - aerogels are the world s lightest solid (among 15 other titles they hold in the Guinness World Records), can float indefinitely on water if treated to be

  17. A Comprehensive Review of Thermal Energy Storage

    Directory of Open Access Journals (Sweden)

    Ioan Sarbu

    2018-01-01

    Full Text Available Thermal energy storage (TES is a technology that stocks thermal energy by heating or cooling a storage medium so that the stored energy can be used at a later time for heating and cooling applications and power generation. TES systems are used particularly in buildings and in industrial processes. This paper is focused on TES technologies that provide a way of valorizing solar heat and reducing the energy demand of buildings. The principles of several energy storage methods and calculation of storage capacities are described. Sensible heat storage technologies, including water tank, underground, and packed-bed storage methods, are briefly reviewed. Additionally, latent-heat storage systems associated with phase-change materials for use in solar heating/cooling of buildings, solar water heating, heat-pump systems, and concentrating solar power plants as well as thermo-chemical storage are discussed. Finally, cool thermal energy storage is also briefly reviewed and outstanding information on the performance and costs of TES systems are included.

  18. Phase change thermal energy storage material

    Science.gov (United States)

    Benson, David K.; Burrows, Richard W.

    1987-01-01

    A thermal energy storge composition is disclosed. The composition comprises a non-chloride hydrate having a phase change transition temperature in the range of 70.degree.-95.degree. F. and a latent heat of transformation of at least about 35 calories/gram.

  19. Thermal energy storage for smart grid applications

    Science.gov (United States)

    Al-Hallaj, Said; Khateeb, Siddique; Aljehani, Ahmed; Pintar, Mike

    2018-01-01

    Energy consumption for commercial building cooling accounts for 15% of all commercial building's electricity usage [1]. Electric utility companies charge their customers time of use consumption charges (/kWh) and additionally demand usage charges (/kW) to limit peak energy consumption and offset their high operating costs. Thus, there is an economic incentive to reduce both the electricity consumption charges and demand charges by developing new energy efficient technologies. Thermal energy storage (TES) systems using a phase change material (PCM) is one such technology that can reduce demand charges and shift the demand from on-peak to off-peak rates. Ice and chilled water have been used in thermal storage systems for many decades, but they have certain limitations, which include a phase change temperature of 0 degrees Celsius and relatively low thermal conductivity in comparison to other materials, which limit their applications as a storage medium. To overcome these limitations, a novel phase change composite (PCC) TES material was developed that has much higher thermal conductivity that significantly improves the charge / discharge rate and a customizable phase change temperature to allow for better integration with HVAC systems. Compared to ice storage, the PCC TES system is capable of very high heat transfer rate and has lower system and operational costs. Economic analysis was performed to compare the PCC TES system with ice system and favorable economics was proven. A 4.5 kWh PCC TES prototype system was also designed for testing and validation purpose.

  20. Plasma thermal energy transport: theory and experiments

    International Nuclear Information System (INIS)

    Coppi, B.

    Experiments on the transport across the magnetic field of electron thermal energy are reviewed (Alcator, Frascati Torus). In order to explain the experimental results, a transport model is described that reconfirmed the need to have an expression for the local diffusion coefficient with a negative exponent of the electron temperature

  1. Biogeochemical aspects of aquifer thermal energy storage

    NARCIS (Netherlands)

    Brons, H.J.

    1992-01-01

    During the process of aquifer thermal energy storage the in situ temperature of the groundwater- sediment system may fluctuate significantly. As a result the groundwater characteristics can be considerably affected by a variety of chemical, biogeochemical and microbiological

  2. Making `Internal Thermal Energy' Visible

    Science.gov (United States)

    Zou, Xueli

    2004-09-01

    In a 1992 paper published in this journal, Uri Ganiel described a pair of model carts used to demonstrate elastic and inelastic collisions. The wooden carts had low-friction wheels and a steel-strip bumper on one end. On one of the carts, a number of brass washers were rigidly mounted in vertical stacks to a wooden framework. The other cart was similar except that the washers were tied to rubber bands that were stretched horizontally and diagonally across the framework. When the first cart was rolled into a wall it bounced off with only a small reduction in speed ("elastic" collision). The second cart, on the other hand, was found to come nearly to a complete stop upon colliding with the wall ("inelastic" collision). Following the instructions given in Ganiel's paper, I built a pair of carts and demonstrated them to introductory-level physics students at a large public university. It was interesting to find that many students were distracted by the different-looking structures of the two model carts.2 They thought the different distributions of washers between the carts resulted in the rubber-band cart bouncing back a significantly shorter distance than the rigid-rod one after they both collided with a wall at the same initial speed. Apparently, the students had difficulties in understanding the collisions and used surface features to reason about them. To avoid this superficial distraction and to help students visualize easily "where the kinetic energy goes in an inelastic collision," I modified the rigid-rod cart to have washers fixed on hollow aluminum rods mounted at four different levels horizontally and diagonally (see Fig. 1). The new pair of the model carts look very similar to each other: They have the same bumpers, same wheels, same distributions of washers, and same masses.

  3. Carrier Compensation Induced by Thermal Annealing in Al-Doped ZnO Films

    Directory of Open Access Journals (Sweden)

    Takashi Koida

    2017-02-01

    Full Text Available This study investigated carrier compensation induced by thermal annealing in sputtered ZnO:Al (Al2O3: 0.25, 0.5, 1.0, and 2.0 wt % films. The films were post-annealed in a N2 atmosphere at low (1 × 10−23 atm and high (1 × 10−4 atm oxygen partial pressures (PO2. In ZnO:Al films with low Al contents (i.e., 0.25 wt %, the carrier density (n began to decrease at annealing temperatures (Ta of 600 °C at low PO2. At higher PO2 and/or Al contents, n values began to decrease significantly at lower Ta (ca. 400 °C. In addition, Zn became desorbed from the films during heating in a high vacuum (i.e., <1 × 10−7 Pa. These results suggest the following: (i Zn interstitials and Zn vacancies are created in the ZnO lattice during post-annealing treatments, thereby leading to carrier compensation by acceptor-type Zn vacancies; (ii The compensation behavior is significantly enhanced for ZnO:Al films with high Al contents.

  4. ENERGY EFFICIENCY, ENERGY SAVING POTENTIAL AND ENVIRONMENTAL IMPACT RESEARCH OF LPG CARRIER REFRIGERATION SYSTEM

    Directory of Open Access Journals (Sweden)

    V. О. Bedrosov

    2016-12-01

    Full Text Available Nowadays energy efficiency improvement and global warming are issues of current interest because of the natural resources depletion and extreme climate change. Thus, the problem of formation of strict regulations regarding emissions into the air arises. This paper presents the study of cascade refrigeration system for re-condensing of associated petroleum gas during sea transportation for LPG carrier. The structural optimization has been performed. LPG gas carriers with 266 000 m3 ethane capacity require 15 MW cascade refrigeration system for re-condensing if the temperature in the coastal LPG storage is -70°C, and the temperature for transported Ethan is maintained at  -75°C. For current storage conditions the required system cooling capacity is only 1,078 MW intended for the heat gain rejection from the environment during Ethane transportation. The replacement of ozone-depleting refrigerant R22 to alternative agents: R407C, R404A, R402A, R717, R290, R1270 was estimated. The results of analysis have shown that the proposed improvements can be used to optimize the LPG carrier cascade refrigeration system

  5. Thermal Energy Storage with Phase Change Material

    Directory of Open Access Journals (Sweden)

    Lavinia Gabriela SOCACIU

    2012-08-01

    Full Text Available Thermal energy storage (TES systems provide several alternatives for efficient energy use and conservation. Phase change materials (PCMs for TES are materials supplying thermal regulation at particular phase change temperatures by absorbing and emitting the heat of the medium. TES in general and PCMs in particular, have been a main topic in research for the last 30 years, but although the information is quantitatively enormous, it is also spread widely in the literature, and difficult to find. PCMs absorb energy during the heating process as phase change takes place and release energy to the environment in the phase change range during a reverse cooling process. PCMs possesses the ability of latent thermal energy change their state with a certain temperature. PCMs for TES are generally solid-liquid phase change materials and therefore they need encapsulation. TES systems using PCMs as a storage medium offers advantages such as high TES capacity, small unit size and isothermal behaviour during charging and discharging when compared to the sensible TES.

  6. Aquifer thermal energy stores in Germany

    International Nuclear Information System (INIS)

    Kabus, F.; Seibt, P.; Poppei, J.

    2000-01-01

    This paper describes the state of essential demonstration projects of heat and cold storage in aquifers in Germany. Into the energy supply system of the buildings of the German Parliament in Berlin, there are integrated both a deep brine-bearing aquifer for the seasonal storage of waste heat from power and heat cogeneration and a shallow-freshwater bearing aquifer for cold storage. In Neubrandenburg, a geothermal heating plant which uses a 1.200 m deep aquifer is being retrofitted into an aquifer heat storage system which can be charged with the waste heat from a gas and steam cogeneration plant. The first centralised solar heating plant including an aquifer thermal energy store in Germany was constructed in Rostock. Solar collectors with a total area of 1000m 2 serve for the heating of a complex of buildings with 108 flats. A shallow freshwater-bearing aquifer is used for thermal energy storage. (Authors)

  7. Carrier thermalization under stimulated emission in In{sub 0.17}Ga{sub 0.83}N epilayer at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Shang, Z. J.; Yang, C.; Chen, Y., E-mail: xinhezheng@ustb.edu.cn, E-mail: ychen@ee.ecnu.edu.cn; Li, B.; Sun, L.; Tang, Z. [Key Laboratory of Polar Materials and Devices, East China Normal University, Shanghai 200241 (China); Zheng, X. H., E-mail: xinhezheng@ustb.edu.cn, E-mail: ychen@ee.ecnu.edu.cn [Department of Physics, Beijing University of Science and Technology, Beijing 100083, People' s Republic of China and Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO), Chinese Academy of Science, Suzhou 215123 (China); Zhao, D. G. [Institute of Semiconductors, Chinese Academy of Science, Beijing 100083 (China)

    2014-12-08

    We elucidate a strong room temperature stimulated emission (SE) of In{sub 0.17}Ga{sub 0.83}N epilayer grown by molecular beam epitaxy under the subpicosecond pulse excitation. The SE peak at 428 nm emerges on the higher energy side of the spontaneous emission in photoluminescence spectra when the excitation density exceeds the threshold of ∼3.68 mJ/cm{sup 2}. Nondegenerate transient differential reflectivity measurements show that a multi-stage carrier thermalization from excited states to localized edge states and stimulated emission dominate the decay processes of photogenerated carriers under various excitation densities. Our results indicate that the existence of phonon bottleneck effect could result in a slow thermalization process in the InGaN material even under the condition of stimulated emission.

  8. Impact of energy filtering and carrier localization on the thermoelectric properties of granular semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Narducci, Dario, E-mail: dario.narducci@unimib.it [Department of Materials Science, University of Milano Bicocca, via Cozzi 53, 20125 Milano (Italy); Consorzio DeltaTi Research (Italy); Selezneva, Ekaterina [Department of Materials Science, University of Milano Bicocca, via Cozzi 53, 20125 Milano (Italy); Cerofolini, Gianfranco [Department of Materials Science, University of Milano Bicocca, via Cozzi 53, 20125 Milano (Italy); Consorzio DeltaTi Research (Italy); Frabboni, Stefano; Ottaviani, Giampiero [Department of Physics, University of Modena and Reggio Emilia, via Campi 213, 41100 Modena (Italy)

    2012-09-15

    Energy filtering has been widely considered as a suitable tool to increase the thermoelectric performances of several classes of materials. In its essence, energy filtering provides a way to increase the Seebeck coefficient by introducing a strongly energy-dependent scattering mechanism. Under certain conditions, however, potential barriers may lead to carrier localization, that may also affect the thermoelectric properties of a material. A model is proposed, actually showing that randomly distributed potential barriers (as those found, e.g., in polycrystalline films) may lead to the simultaneous occurrence of energy filtering and carrier localization. Localization is shown to cause a decrease of the actual carrier density that, along with the quantum tunneling of carriers, may result in an unexpected increase of the power factor with the doping level. The model is corroborated toward experimental data gathered by several authors on degenerate polycrystalline silicon and lead telluride. - Graphical abstract: In heavily doped semiconductors potential barriers may lead to both carrier energy filtering and localization. This may lead to an enhancement of the thermoelectric properties of the material, resulting in an unexpected increase of the power factor with the doping level. Highlights: Black-Right-Pointing-Pointer Potential barriers are shown to lead to carrier localization in thermoelectric materials. Black-Right-Pointing-Pointer Evidence is put forward of the formation of a mobility edge. Black-Right-Pointing-Pointer Energy filtering and localization may explain the enhancement of power factor in degenerate semiconductors.

  9. Thermal Profiling of Residential Energy Use

    Energy Technology Data Exchange (ETDEWEB)

    Albert, A; Rajagopal, R

    2015-03-01

    This work describes a methodology for informing targeted demand-response (DR) and marketing programs that focus on the temperature-sensitive part of residential electricity demand. Our methodology uses data that is becoming readily available at utility companies-hourly energy consumption readings collected from "smart" electricity meters, as well as hourly temperature readings. To decompose individual consumption into a thermal-sensitive part and a base load (non-thermally-sensitive), we propose a model of temperature response that is based on thermal regimes, i.e., unobserved decisions of consumers to use their heating or cooling appliances. We use this model to extract useful benchmarks that compose thermal profiles of individual users, i.e., terse characterizations of the statistics of these users' temperature-sensitive consumption. We present example profiles generated using our model on real consumers, and show its performance on a large sample of residential users. This knowledge may, in turn, inform the DR program by allowing scarce operational and marketing budgets to be spent on the right users-those whose influencing will yield highest energy reductions-at the right time. We show that such segmentation and targeting of users may offer savings exceeding 100% of a random strategy.

  10. Operational Experience from Solar Thermal Energy Projects

    Science.gov (United States)

    Cameron, C. P.

    1984-01-01

    Over the past few years, Sandia National Laboratories were involved in the design, construction, and operation of a number of DOE-sponsored solar thermal energy systems. Among the systems currently in operation are several industrial process heat projects and the Modular Industrial Solar Retrofit qualification test systems, all of which use parabolic troughs, and the Shenandoah Total Energy Project, which uses parabolic dishes. Operational experience has provided insight to both desirable and undesirable features of the designs of these systems. Features of these systems which are also relevant to the design of parabolic concentrator thermal electric systems are discussed. Other design features discussed are system control functions which were found to be especially convenient or effective, such as local concentrator controls, rainwash controls, and system response to changing isolation. Drive systems are also discussed with particular emphasis of the need for reliability and the usefulness of a manual drive capability.

  11. Energy, Power and Thermal Research Overview

    Science.gov (United States)

    2010-09-01

    Watt power generation • Magnetic materials • Thermoelectric power generation • Mega-Watt power generation ‒ Superconducting and conventional...FeCo) • Multilayered structures for thermoelectric power generation ‒ Oxide materials ‒ Promote phonon scattering to inhibit thermal flow and increase...and space force. 4 AFRL’s Core Areas of Expertise Space Vehicles Materials Directed Energy Munitions Propulsion Human Effectiveness Information

  12. Special conference on thermal energy 'Yugoslavia 1986'

    International Nuclear Information System (INIS)

    1986-01-01

    This volume contains various papers held at the conference 'Thermoenergetica 1986'. The papers cover subjects ranging from the development of thermal energy in Yugoslavia via fluidized-bed combustion and experience gained with the construction and operation of coal-fuelled plants to the grinding and combustion of coals rich in inerts, pollution problems, fouling and slag formation, service life, stress-induced crack corrosions, and to the planning, construction and operation of nuclear power plants. (HAG) [de

  13. Analysis of lunar regolith thermal energy storage

    Science.gov (United States)

    Colozza, Anthony J.

    1991-01-01

    The concept of using lunar regolith as a thermal energy storage medium was evaluated. The concept was examined by mathematically modeling the absorption and transfer of heat by the lunar regolith. Regolith thermal and physical properties were established through various sources as functions of temperature. Two cases were considered: a semi-infinite, constant temperature, cylindrical heat source embedded in a continuum of lunar regolith and a spherically shaped molten zone of lunar regolith set with an initial temperature profile. The cylindrical analysis was performed in order to examine the amount of energy which can be stored in the regolith during the day. At night, the cylinder acted as a perfect insulator. This cycling was performed until a steady state situation was reached in the surrounding regolith. It was determined that a cycling steady state occurs after approximately 15 day/night cycles. Results were obtained for cylinders of various diameters. The spherical molten zone analysis was performed to establish the amount of thermal energy, within the regolith, necessary to maintain some molten material throughout a nighttime period. This surrounding temperature profile was modeled after the cycling steady state temperature profile established by the cylindrical analysis. It was determined that a molten sphere diameter of 4.76 m is needed to maintain a core temperature near the low end of the melting temperature range throughout one nighttime period.

  14. Revisit ocean thermal energy conversion system

    International Nuclear Information System (INIS)

    Huang, J.C.; Krock, H.J.; Oney, S.K.

    2003-01-01

    The earth, covered more than 70.8% by the ocean, receives most of its energy from the sun. Solar energy is transmitted through the atmosphere and efficiently collected and stored in the surface layer of the ocean, largely in the tropical zone. Some of the energy is re-emitted to the atmosphere to drive the hydrologic cycle and wind. The wind field returns some of the energy to the ocean in the form of waves and currents. The majority of the absorbed solar energy is stored in vertical thermal gradients near the surface layer of the ocean, most of which is in the tropical region. This thermal energy replenished each day by the sun in the tropical ocean represents a tremendous pollution-free energy resource for human civilization. Ocean Thermal Energy Conversion (OTEC) technology refers to a mechanical system that utilizes the natural temperature gradient that exists in the tropical ocean between the warm surface water and the deep cold water, to generate electricity and produce other economically valuable by-products. The science and engineering behind OTEC have been studied in the US since the mid-seventies, supported early by the U.S. Government and later by State and private industries. There are two general types of OTEC designs: closed-cycle plants utilize the evaporation of a working fluid, such as ammonia or propylene, to drive the turbine-generator, and open-cycle plants use steam from evaporated sea water to run the turbine. Another commonly known design, hybrid plants, is a combination of the two. OTEC requires relatively low operation and maintenance costs and no fossil fuel consumption. OTEC system possesses a formidable potential capacity for renewable energy and offers a significant elimination of greenhouse gases in producing power. In addition to electricity and drinking water, an OTEC system can produce many valuable by-products and side-utilizations, such as: hydrogen, air-conditioning, ice, aquaculture, and agriculture, etc. The potential of these

  15. Carrier density distribution in silicon nanowires investigated by scanning thermal microscopy and Kelvin probe force microscopy.

    Science.gov (United States)

    Wielgoszewski, Grzegorz; Pałetko, Piotr; Tomaszewski, Daniel; Zaborowski, Michał; Jóźwiak, Grzegorz; Kopiec, Daniel; Gotszalk, Teodor; Grabiec, Piotr

    2015-12-01

    The use of scanning thermal microscopy (SThM) and Kelvin probe force microscopy (KPFM) to investigate silicon nanowires (SiNWs) is presented. SThM allows imaging of temperature distribution at the nanoscale, while KPFM images the potential distribution with AFM-related ultra-high spatial resolution. Both techniques are therefore suitable for imaging the resistance distribution. We show results of experimental examination of dual channel n-type SiNWs with channel width of 100 nm, while the channel was open and current was flowing through the SiNW. To investigate the carrier distribution in the SiNWs we performed SThM and KPFM scans. The SThM results showed non-symmetrical temperature distribution along the SiNWs with temperature maximum shifted towards the contact of higher potential. These results corresponded to those expressed by the distribution of potential gradient along the SiNWs, obtained using the KPFM method. Consequently, non-uniform distribution of resistance was shown, being a result of non-uniform carrier density distribution in the structure and showing the pinch-off effect. Last but not least, the results were also compared with results of finite-element method modeling. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Electrical Conductivity of Rocks and Dominant Charge Carriers. Part 1; Thermally Activated Positive Holes

    Science.gov (United States)

    Freund, Friedemann T.; Freund, Minoru M.

    2012-01-01

    The prevailing view in the geophysics community is that the electrical conductivity structure of the Earth's continental crust over the 5-35 km depth range can best be understood by assuming the presence of intergranular fluids and/or of intragranular carbon films. Based on single crystal studies of melt-grown MgO, magma-derived sanidine and anorthosite feldspars and upper mantle olivine, we present evidence for the presence of electronic charge carriers, which derive from peroxy defects that are introduced during cooling, under non-equilibrium conditions, through a redox conversion of pairs of solute hydroxyl arising from dissolution of H2O.The peroxy defects become thermally activated in a 2-step process, leading to the release of defect electrons in the oxygen anion sublattice. Known as positive holes and symbolized by h(dot), these electronic charge carriers are highly mobile. Chemically equivalent to O(-) in a matrix of O(2-) they are highly oxidizing. Being metastable they can exist in the matrix of minerals, which crystallized in highly reduced environments. The h(dot) are highly mobile. They appear to control the electrical conductivity of crustal rocks in much of the 5-35 km depth range.

  17. Building climate energy management in smart thermal grids via aquifer thermal energy storage systems

    NARCIS (Netherlands)

    Rostampour Samarin, V.; Jaxa-Rozen, M.; Bloemendal, J.M.; Keviczky, T.; Ask, M; Bruckman, V; Juhlin, C; Kempka, Th; Kühn, M

    2016-01-01

    This paper proposes a building energy management framework, described by mixed logical dynamical systems due to operating constraints and logic rules, together with an aquifer thermal energy storage (ATES) model. We develop a deterministic model predictive control strategy to meet building

  18. Some aspects of hydrogen as a long-term energy carrier

    International Nuclear Information System (INIS)

    Quakernaat, J.; De Jong, K.P.; Van Wechem, H.M.H.; Okken, P.A.; Lako, P.; Ybema, J.R.

    1994-11-01

    Hydrogen as a secondary energy carrier received extensive and worldwide attention some ten to fifteen years ago. The developments in the energy market since then have reduced the interest in hydrogen. However, the increased concern for the environment and new technical options have brought hydrogen to the centre of attention once again. These considerations led to the organization of the National Hydrogen Seminar, held on 19 November 1993 at ECN, Petten, Netherlands. Eight experts in the field of hydrogen illustrated the possibilities and prospects of the production, storage and use of hydrogen as an energy carrier. In this report three of these contributions are presented, for which separate abstracts have been prepared. The first paper is on hydrogen in a global long-term perspective, in the second paper carbon is considered as a hydrogen carrier or as a disappearing skeleton, and in the third paper attention is paid to the cost effective integration of hydrogen in energy systems with CO 2 constraints

  19. A comparative study of ammonia energy systems as a future energy carrier, with particular reference to vehicle use in Japan

    International Nuclear Information System (INIS)

    Miura, Daisuke; Tezuka, Tetsuo

    2014-01-01

    The choice of secondary energy carriers, such as electricity, hydrogen and ammonia, influences not only economic and environmental performances but also the reliability of an entire energy system. This article focuses on ammonia because of its excellent property in energy storage, and assesses the relative advantages of several ammonia energy systems for vehicle use in Japan by estimating energy efficiency, CO 2 emissions, and the supply cost of several ammonia energy paths, which are then compared with alternative paths using different energy carriers including hydrogen and electricity. The article also discusses inherent merits and challenges of ammonia energy systems and identifies directions for future research and development. Using ammonia as an energy carrier was demonstrated to be competitive in terms of efficiency, CO 2 emissions and supply cost for energy systems requiring fairly large numbers of storage days. This assessment shows that the use of ammonia in an energy system can improve the continuity of the energy supply in a country or region with insecurity of supply. On the other hand, we argue that further technical improvements and cost reduction associated with both conventional and unconventional ammonia production is imperative for using ammonia in a normal energy system. - Highlights: • We assess merits of energy supply systems using ammonia as an energy carrier. • Comparison with hydrogen or electricity-based energy systems was carried out. • We find ammonia is competitive when requiring large numbers of storage days. • The use of ammonia in energy systems can improve the continuity of energy supply. • Technical improvements are needed to make ammonia attractive in normal systems

  20. Coupling Geothermal Heat Pumps with Underground Seasonal Thermal Energy Storage

    Science.gov (United States)

    2017-03-21

    EW-201135) Coupling Geothermal Heat Pumps with Underground Seasonal Thermal Energy Storage March 2017 This document has been cleared for...09/2011-03/2017 4. TITLE AND SUBTITLE Coupling Geothermal Heat Pumps with Underground Seasonal Thermal Energy Storage 5a...v ACRONYMS AND ABBREVIATIONS AGWT American Ground Water Trust AHU Air Handling Unit ATES Aquifer Thermal Energy Storage BTES Borehole

  1. Attenuation of Scattered Thermal Energy Atomic Oxygen

    Science.gov (United States)

    Banks, Bruce A.; Seroka, Katelyn T.; McPhate, Jason B.; Miller, Sharon K.

    2011-01-01

    The attenuation of scattered thermal energy atomic oxygen is relevant to the potential damage that can occur within a spacecraft which sweeps through atomic oxygen in low Earth orbit (LEO). Although there can be significant oxidation and resulting degradation of polymers and some metals on the external surfaces of spacecraft, there are often openings on a spacecraft such as telescope apertures, vents, and microwave cavities that can allow atomic oxygen to enter and scatter internally to the spacecraft. Atomic oxygen that enters a spacecraft can thermally accommodate and scatter to ultimately react or recombine on surfaces. The atomic oxygen that does enter a spacecraft can be scavenged by use of high erosion yield polymers to reduce its reaction on critical surfaces and materials. Polyoxymethylene and polyethylene can be used as effective atomic oxygen scavenging polymers.

  2. Energy analysis of thermal energy storages with grid configurations

    International Nuclear Information System (INIS)

    Rezaie, Behnaz; Reddy, Bale V.; Rosen, Marc A.

    2014-01-01

    Highlights: • Grid configurations of TESs are developed and assessed. • Characteristics of various configurations of TESs are developed as functions of properties. • Functions for the discharge temperature and the discharge energy of the TES are developed. - Abstract: In some thermal networks like district energy systems, there can exist conditions, depending on space availability, economics, project requirements, insulation, storing media type and other issues, for which it may be advantageous to utilize several thermal energy storages (TESs) instead of one. Here, various configurations for multiple TESs are proposed and investigated. Significant parameters for a TES, or a set of TESs, include discharging temperature and recovered energy. First, one TES is modeled to determine the final temperature, energy recovery, and energy efficiency. Next, characteristics for various grid configurations of multiple TESs are developed as functions of TES characteristics (e.g., charging and discharging temperatures and energy quantities). Series, parallel and comprehensive grid TES configurations are considered. In the parallel configuration, the TESs behave independently. This suggests that the TES can consist of different storage media types and sizes, and that there is no restriction on initial temperature of the TES. In the series configuration, the situation is different because the TESs are connected directly or indirectly through a heat exchanger. If there is no heat exchanger between the TESs, the TES storage media should be the same, because the outlet of one TES in the series is the inlet to the next. The initial temperature of the second TES must be smaller than the discharge temperature of the first. There is no restriction on the TES size for series configurations. The general grid configuration is observed to exhibit characteristics of both series and parallel configurations

  3. More Wind Power Integration with Adjusted Energy Carriers for Space Heating in Northern China

    Directory of Open Access Journals (Sweden)

    Jianjun He

    2012-08-01

    Full Text Available In Northern China, due to the high penetration of coal-fired cogeneration facilities, which are generally equipped with extraction-condensing steam turbines, lots of wind power resources may be wasted during the heating season. In contrast, considerable coal is consumed in the power generation sector. In this article, firstly it is revealed that there exists a serious divergence in the ratio of electrical to thermal energy between end users’ demand and the cogenerations’ production during off-peak load at night, which may negate active power-balancing of the electric power grid. Secondly, with respect to this divergence only occurring during off-peak load at night, a temporary proposal is given so as to enable the integration of more wind power. The authors suggest that if the energy carrier for part of the end users’ space heating is switched from heating water to electricity (e.g., electric heat pumps (EHPs can provide space heating in the domestic sector, the ratio of electricity to heating water load should be adjusted to optimize the power dispatch between cogeneration units and wind turbines, resulting in fuel conservation. With this proposal, existing infrastructures are made full use of, and no additional ones are required. Finally a numerical simulation is performed in order to illustrate both the technical and economic feasibility of the aforementioned proposal, under ongoing infrastructures as well as electricity and space heating tariff conditions without changing participants’ benefits. The authors aim to persuade Chinese policy makers to enable EHPs to provide space heating to enable the integration of more wind power.

  4. The thermal solar energy - September 2010

    International Nuclear Information System (INIS)

    Acket, C.

    2010-01-01

    The author first notices that the use of solar heat to produce electricity is much lesser known than the production of electricity by photovoltaic effect. He also notices that few efforts have been made in France to develop this technology (thermal solar energy, also called helio-thermodynamics). He evokes the Themis project and also some initiatives in Spain and in California. He recalls some data about solar heat, presents the solar concentration technique which either uses a parabolic configuration (point focus concentration) or a cylindrical and parabolic configuration (line concentration system). He briefly presents the different techniques used to transform solar heat into electricity and to store the electricity. He briefly presents different solutions which have been tested over the past years in France, Germany, Spain, California and Israel (tower and air, gas and Stirling cycle, tower and direct vapour production, cylindrical-parabolic collector). He discusses the effect of intermittency and the French context, and questions and discusses the choice between thermal and photovoltaic solar energy (advantages and drawbacks)

  5. Commercialization of aquifer thermal energy storage technology

    Energy Technology Data Exchange (ETDEWEB)

    Hattrup, M.P.; Weijo, R.O.

    1989-09-01

    Pacific Northwest Laboratory (PNL) conducted this study for the US Department of Energy's (DOE) Office of Energy Storage and Distribution. The purpose of the study was to develop and screen a list of potential entry market applications for aquifer thermal energy storage (ATES). Several initial screening criteria were used to identify promising ATES applications. These include the existence of an energy availability/usage mismatch, the existence of many similar applications or commercial sites, the ability to utilize proven technology, the type of location, market characteristics, the size of and access to capital investment, and the number of decision makers involved. The in-depth analysis identified several additional screening criteria to consider in the selection of an entry market application. This analysis revealed that the best initial applications for ATES are those where reliability is acceptable, and relatively high temperatures are allowable. Although chill storage was the primary focus of this study, applications that are good candidates for heat ATES were also of special interest. 11 refs., 3 tabs.

  6. Thermal and mechanical behaviour of oxygen carrier materials for chemical looping combustion in a packed bed reactor

    International Nuclear Information System (INIS)

    Jacobs, M.; Van Noyen, J.; Larring, Y.; Mccann, M.; Pishahang, M.; Amini, S.; Ortiz, M.; Galluci, F.; Sint-Annaland, M.V.; Tournigant, D.; Louradour, E.; Snijkers, F.

    2015-01-01

    Highlights: • Ilmenite-based oxygen carriers were developed for packed-bed chemical looping. • Addition of Mn 2 O 3 increased mechanical strength and microstructure of the carriers. • Oxygen carriers were able to withstand creep and thermal cycling up to 1200 °C. • Ilmenite-based granules are a promising shape for packed-bed reactor conditions. - Abstract: Chemical looping combustion (CLC) is a promising carbon capture technology where cyclic reduction and oxidation of a metallic oxide, which acts as a solid oxygen carrier, takes place. With this system, direct contact between air and fuel can be avoided, and so, a concentrated CO 2 stream is generated after condensation of the water in the exit gas stream. An interesting reactor system for CLC is a packed bed reactor as it can have a higher efficiency compared to a fluidized bed concept, but it requires other types of oxygen carrier particles. The particles must be larger to avoid a large pressure drop in the reactor and they must be mechanically strong to withstand the severe reactor conditions. Therefore, oxygen carriers in the shape of granules and based on the mineral ilmenite were subjected to thermal cycling and creep tests. The mechanical strength of the granules before and after testing was investigated by crush tests. In addition, the microstructure of these oxygen particles was studied to understand the relationship between the physical properties and the mechanical performance. It was found that the granules are a promising shape for a packed bed reactor as no severe degradation in strength was noticed upon thermal cycling and creep testing. Especially, the addition of Mn 2 O 3 to the ilmenite, which leads to the formation of an iron–manganese oxide, seems to results in stronger granules than the other ilmenite-based granules.

  7. Economics of compressed air energy storage employing thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Schulte, S.C.; Reilly, R.W.

    1979-11-01

    The approach taken in this study is to adopt system design and capital cost estimates from three independent CAES studies (eight total designs) and, by supplying a common set of fuel/energy costs and economic assumptions in conjunction with a common methodology, to arrive at a series of levelized energy costs over the system's lifetime. In addition, some analyses are provided to gauge the sensitivity of these levelized energy costs to fuel and compression energy costs and to system capacity factors. The systems chosen for comparison are of four generic types: conventional CAES, hybrid CAES, adiabatic CAES, and an advanced-design gas turbine (GT). In conventional CAES systems the heat of compression generated during the storage operation is rejected to the environment, and later, during the energy-generation phase, turbine fuel must be burned to reheat the compressed air. In the hybrid systems some of the heat of compression is stored and reapplied later during the generation phase, thereby reducing turbine fuel requirements. The adiabatic systems store adequate thermal energy to eliminate the need for turbine fuel entirely. The gas turbine is included within the report for comparison purposes; it is an advanced-design turbine, one that is expected to be available by 1985.

  8. District Energy Corporation SW 40th Street Thermal Energy Plant

    Energy Technology Data Exchange (ETDEWEB)

    Davlin, Thomas [District Energy Corporation, Lincoln, NE (United States)

    2014-06-06

    The overall deliverable from the project is the design, construction and commissioning of a detention facility heating and cooling system that minimizes ownership costs and maximizes efficiency (and therefore minimizes environmental impact). The primary deliverables were the proof of concept for the application of geothermal systems for an institutional facility and the ongoing, quarterly system operating data downloads to the Department of Energy . The primary advantage of geothermal based heat pump systems is the higher efficiency of the system compared to a conventional chiller, boiler, cooling tower based system. The higher efficiency results in a smaller environmental foot print and lower energy costs for the detention facility owner, Lancaster County. The higher efficiency for building cooling is primarily due to a more constant compressor condensing temperature with the geothermal well field acting as a thermal “sink” (in place of the conventional system’s cooling tower). In the heating mode, Ground Couple Heat Pump (GCHP) systems benefits from the advantage of a heat pump Coefficient of Performance (COP) of approximately 3.6, significantly better than a conventional gas boiler. The geothermal well field acting as a thermal “source” allows the heat pumps to operate efficiently in the heating mode regardless of ambient temperatures. The well field is partially located in a wetland with a high water table so, over time, the project will be able to identify the thermal loading characteristics of a well field located in a high water table location. The project demonstrated how a large geothermal well field can be installed in a wetland area in an economical and environmentally sound manner. Finally, the SW 40th Street Thermal Energy Plant project demonstrates the benefits of providing domestic hot water energy, as well as space heating, to help balance well filed thermal loading in a cooling dominated application. During the period of August 2012 thru

  9. Proceedings of the General Committee for solar thermal energy 2015

    International Nuclear Information System (INIS)

    Gibert, Francois; Loyen, Richard; Khebchache, Bouzid; Cholin, Xavier; Leicher, David; Mozas, Kevin; Leclercq, Martine; Laugier, Patrick; Dias, Pedro; Kuczer, Eric; Benabdelkarim, Mohamed; Brottier, Laetitia; Soussana, Max; Cheze, David; Mugnier, Daniel; Laplagne, Valerie; Mykieta, Frederic; Ducloux, Antoine; Egret, Dominique; Noisette, Nadege; Peneau, Yvan; Seguis, Anne-Sophie; Gerard, Roland

    2017-10-01

    After an introducing contribution which discussed the difficult evolution of the solar thermal energy sector in 2015, contributions addressed development plans for SOCOL (a plan for collective solar thermal and solar heat) which aims at reviving the market and at opening new markets. A next set of contributions discussed how solar thermal energy can be at the service of energy transition. Following sessions addressed issues like innovation at the service of solar thermal energy, energetic display of solar systems and application of the Ecodesign and Labelling directives, and the reduction of carbon footprint and the energy dependence of territories

  10. Standardization of the water heat carrier quality at Russian thermal power plants

    Science.gov (United States)

    Larin, B. M.; Larin, A. B.; Suslov, S. Yu.; Kirilina, A. V.

    2017-04-01

    The necessity of developing a new industry-specific standard of the heat carrier quality for the operating, newly commissioned, and prospective power-generating units of the thermal power plants is substantiated. The need of extending the scope of the automatic chemical monitoring and the possibility of indirect measurements of some basic standardized and diagnostic indices of the water chemistry using the specific conductance are shown. Investigations proved the possibility of automatic chemical monitoring of the phosphating of the drum boilers and quantitative control of potentially acidic impurities in the feed water in oncethrough boilers. The normative STO NP INVEL document developed at OAO VTI in 2009 is proposed as the basis for alterations and amendments. A new index, the total organic carbon, is introduced into this document. The standardized value of this index in the drum boiler feed water and steam is 100 μg/dm3. According to the above normative document, the scope of the chemical monitoring should be extended by measurements of the specific conductance of the direct and H-cation samples of both the feed and the boiler water. The content of chlorides should also be standardized. For the first time, normative restrictions are suggested on amine-containing water chemistry of the power-generating units with the combined cycle gas turbines. Flowcharts are proposed for pretreatment of the make-up water on the basis of low-mineralized natural waters with high organic substance contents, which reduces the oxidizability by 70-80%.

  11. Modelling and monitoring of Aquifer Thermal Energy Storage : impacts of soil heterogeneity, thermal interference and bioremediation

    NARCIS (Netherlands)

    Sommer, W.T.

    2015-01-01

    Modelling and monitoring of Aquifer Thermal Energy Storage Impacts of heterogeneity, thermal interference and bioremediation Wijbrand Sommer
    PhD thesis, Wageningen University, Wageningen, NL (2015)
    ISBN 978-94-6257-294-2 Abstract Aquifer thermal energy storage (ATES) is

  12. National economic aspects of non-electric secondary energy carriers produced by nuclear plants

    International Nuclear Information System (INIS)

    Barnert, H.; Bohn, T.

    1976-01-01

    The potential for nuclear process heat is being disclosed on the basis of energy requirements and, in particular, with a view to heat demand. Secondary energy carriers, which can be produced with the aid of nuclear process heat, are gaining particular significance in a time where shortages in oil and natural gas are to be expected. Competing with electric power, they will acquire a noticeable share in the supply of final energy for reasons of an increased security of supply as well as for economical reasons. The various technical possibilities for the production of line-dependent secondary energy carriers are being demonstrated. Following this, it will be pointed out that the long lead times required for these technologies necessitate an expeditious and energetic pursuance of adequate developments even today. Finally it will be shown at what rates an implementation of the different technologies is possible. (orig.) [de

  13. MEMS based pyroelectric thermal energy harvester

    Science.gov (United States)

    Hunter, Scott R; Datskos, Panagiotis G

    2013-08-27

    A pyroelectric thermal energy harvesting apparatus for generating an electric current includes a cantilevered layered pyroelectric capacitor extending between a first surface and a second surface, where the first surface includes a temperature difference from the second surface. The layered pyroelectric capacitor includes a conductive, bimetal top electrode layer, an intermediate pyroelectric dielectric layer and a conductive bottom electrode layer. In addition, a pair of proof masses is affixed at a distal end of the layered pyroelectric capacitor to face the first surface and the second surface, wherein the proof masses oscillate between the first surface and the second surface such that a pyroelectric current is generated in the pyroelectric capacitor due to temperature cycling when the proof masses alternately contact the first surface and the second surface.

  14. Anaerobic biotechnological approaches for production of liquid energy carriers from biomass

    DEFF Research Database (Denmark)

    Karakashev, Dimitar Borisov; Thomsen, Anne Belinda; Angelidaki, Irini

    2007-01-01

    In recent years, increasing attention has been paid to the use of renewable biomass for energy production. Anaerobic biotechnological approaches for production of liquid energy carriers (ethanol and a mixture of acetone, butanol and ethanol) from biomass can be employed to decrease environmental...... is determined by substrates and microbial communities available as well as the operating conditions applied. In this review, we evaluate the recent biotechnological approaches employed in ethanol and ABE fermentation. Practical applicability of different technologies is discussed taking into account...

  15. THERMAL INSULATION EFFECTS ON ENERGY EFFICIENCY OF BUILDING STRUCTURES

    Directory of Open Access Journals (Sweden)

    M. Cvetkovska

    2012-05-01

    Full Text Available This paper presents the use of Finite Element Method for heat transfer analysis. Connections wall-beam-floor structures with different positions of the thermal insulation have been analyzed and conclusions about energy efficiency and energy loss are made. Keywords: heat transfer, numerical analysis, finite elements, thermal insulation, energy efficiency.

  16. LTE UE Energy Saving by Applying Carrier Aggregation in a HetNet Scenario

    DEFF Research Database (Denmark)

    Lauridsen, Mads; Wang, Hua; Mogensen, Preben

    2013-01-01

    In this work it is examined if downlink Carrier Aggregation (CA) can be used to save UE energy. A dual-receiver LTE release 10 UE is compared with a single-receiver LTE release 8 UE. The models are based on scaling of an existing LTE release 8 UE power model. The energy consumption of the UEs...... is examined in a Heterogeneous Network scenario consisting of macro and small cells. The unexpected conclusion is that CA UEs can save energy, compared to LTE release 8 UEs, if they, depending on cell load, experience a throughput gain of 20%. However if the UE throughput is unaltered the energy consumption...

  17. Solar Thermal energy strategic road-map

    International Nuclear Information System (INIS)

    Hafner, Bernd; Godin, Olivier; Villier, Dominique; Petit, J.F.; Demangeon, Elsa; Laplagne, Valerie; Loyen, Richard; Mugnier, Daniel; Filloux, Alain; Frichet, Jean-Claude; Aubert, Elisabeth; Cherepanova, Margarita; Guilmin, Audrey; Dicostanzo, Catherine; Papillon, Philippe; Caccavelli, Dominique; Cholin, Xavier; Leger, Emmanuel; Gevaudan, Alain; Coulaud, Celine; Morlot, Rodolphe; Khebchache, Bouzid; Parrouffe, Jean-Michel; Clement, Daniel; Tonnet, Nicolas

    2012-11-01

    The French Environment and Energy Management Agency (ADEME) manages a fund dedicated to new energy technologies. Since 2008 this fund has funded 'research demonstrators' to implement testing of technologies that are in an experimental stage, between research and industrial deployment. ADEME coordinates a group of experts who are charged with drawing up a strategic road-map prior to each Call for Expressions of Interest. The aims of the solar thermal road-map are: - to highlight the industrial, technological, environmental and societal issues at stake; - to elaborate coherent, consistent and shared visions of the technologies and/or socio-technical systems outlined in the road-map; - to underscore the technological, organisational and socioeconomic barriers and bottlenecks to be overcome in order to achieve these visions; - to link priority research topics to a timetable of goals for technology availability and deployment that is consistent with the stated objectives; - to give priority to research needs and research demonstrators that will serve as the basis for: 1 - calls for expression of interest issued by the Research Demonstrators Fund, 2 - the research programming process at ADEME and more broadly at the Agence nationale de la recherche (ANR) and the Comite strategique national sur la recherche sur l'energie. Research priorities and needs for demonstrators are determined by the intersection of visions and bottlenecks. They also take into account industrial and research capacity in France. The road-maps may also refer to exemplary research demonstrators abroad that are in the forefront of technological progress, and make recommendations regarding industrial policy. These road-maps are the result of collective work by a group of experts appointed by the Steering Committee (Comite de pilotage, COPIL) of the Research Demonstrators Fund for new energy technologies. The members of this group are actors in research, drawn from industry, research bodies and research

  18. Subsurface Thermal Energy Storage for Improved Air Conditioning Efficiency

    Science.gov (United States)

    2016-11-01

    EW-201013) Subsurface Thermal Energy Storage for Improved Air Conditioning Efficiency November 2016 This document has been cleared for public...December 2016 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER 10-C-0027-A Cost and Performance Report. Subsurface Thermal Energy Storage for Improved...distribution is unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT This project involved a field demonstration of subsurface thermal energy storage for

  19. Ocean Thermal Energy Conversion Life Cycle Cost Assessment, Final Technical Report, 30 May 2012

    Energy Technology Data Exchange (ETDEWEB)

    Martel, Laura [Lockheed Martin, Manassas, VA (United States); Smith, Paul [John Halkyard and Associates: Glosten Associates, Houston, TX (United States); Rizea, Steven [Makai Ocean Engineering, Waimanalo, HI (United States); Van Ryzin, Joe [Makai Ocean Engineering, Waimanalo, HI (United States); Morgan, Charles [Planning Solutions, Inc., Vancouver, WA (United States); Noland, Gary [G. Noland and Associates, Inc., Pleasanton, CA (United States); Pavlosky, Rick [Lockheed Martin, Manassas, VA (United States); Thomas, Michael [Lockheed Martin, Manassas, VA (United States); Halkyard, John [John Halkyard and Associates: Glosten Associates, Houston, TX (United States)

    2012-05-30

    The Ocean Thermal Energy Conversion (OTEC) Life Cycle Cost Assessment (OLCCA) is a study performed by members of the Lockheed Martin (LM) OTEC Team under funding from the Department of Energy (DOE), Award No. DE-EE0002663, dated 01/01/2010. OLCCA objectives are to estimate procurement, operations and maintenance, and overhaul costs for two types of OTEC plants: -Plants moored to the sea floor where the electricity produced by the OTEC plant is directly connected to the grid ashore via a marine power cable (Grid Connected OTEC plants) -Open-ocean grazing OTEC plant-ships producing an energy carrier that is transported to designated ports (Energy Carrier OTEC plants) Costs are developed using the concept of levelized cost of energy established by DOE for use in comparing electricity costs from various generating systems. One area of system costs that had not been developed in detail prior to this analysis was the operations and sustainment (O&S) cost for both types of OTEC plants. Procurement costs, generally referred to as capital expense and O&S costs (operations and maintenance (O&M) costs plus overhaul and replacement costs), are assessed over the 30 year operational life of the plants and an annual annuity calculated to achieve a levelized cost (constant across entire plant life). Dividing this levelized cost by the average annual energy production results in a levelized cost of electricity, or LCOE, for the OTEC plants. Technical and production efficiency enhancements that could result in a lower value of the OTEC LCOE were also explored. The thermal OTEC resource for Oahu, Hawaii and projected build out plan were developed. The estimate of the OTEC resource and LCOE values for the planned OTEC systems enable this information to be displayed as energy supplied versus levelized cost of the supplied energy; this curve is referred to as an Energy Supply Curve. The Oahu Energy Supply Curve represents initial OTEC deployment starting in 2018 and demonstrates the

  20. From Molecular Electronics to Solar Thermal Energy Storage

    DEFF Research Database (Denmark)

    Olsen, Stine Tetzschner

    for the utilization of solar energy. An eective technology for storing the solar energy is required. This thesis focuses on solar thermal energy storage in molecules, since it oers a very compact and eective storage method. The rst chapter after the introduction of the thesis, chapter two, introduces the fundamental...... of storing solar thermal energy. A theoretical model describing both the macroscopic and the microscopic parameters of a hybrid solar thermal system consisting of a solar water heating system and a molecular solar thermal system (MOST) for energy storage is presented. The model elucidates how much stored...... energy dierent types of molecular classes can be expected to produce in a realistic system setup. The photochromic system of dihydroazulene (DHA)/ vinylheptafulvene (VHF) is of particular interest. The DHA/VHF system is found to be a very promising molecular system for solar thermal energy storage...

  1. Ultra-high thermal effusivity materials for resonant ambient thermal energy harvesting.

    Science.gov (United States)

    Cottrill, Anton L; Liu, Albert Tianxiang; Kunai, Yuichiro; Koman, Volodymyr B; Kaplan, Amir; Mahajan, Sayalee G; Liu, Pingwei; Toland, Aubrey R; Strano, Michael S

    2018-02-14

    Materials science has made progress in maximizing or minimizing the thermal conductivity of materials; however, the thermal effusivity-related to the product of conductivity and capacity-has received limited attention, despite its importance in the coupling of thermal energy to the environment. Herein, we design materials that maximize the thermal effusivity by impregnating copper and nickel foams with conformal, chemical-vapor-deposited graphene and octadecane as a phase change material. These materials are ideal for ambient energy harvesting in the form of what we call thermal resonators to generate persistent electrical power from thermal fluctuations over large ranges of frequencies. Theory and experiment demonstrate that the harvestable power for these devices is proportional to the thermal effusivity of the dominant thermal mass. To illustrate, we measure persistent energy harvesting from diurnal frequencies, extracting as high as 350 mV and 1.3 mW from approximately 10 °C diurnal temperature differences.

  2. Material Behavior of Window 7 Carrier Panel Tiles and Thermal Pane Fragments Recovered from the Space Shuttle Columbia

    Science.gov (United States)

    Arellano, Brenda R.

    Since the end of the space shuttle program, a new generation spacecraft has been developed to transport humans back into space. NASA's Orion will carry a crew beyond low-earth orbit and the exploration of Mars may be possible in the future. Space safety becomes significant with human spaceflight and the risks are high. However, aerospace materials may provide opportunities to prevent future disasters. When the space shuttle Columbia disintegrated during re-entry in 2001, thousands of debris were collected for analysis. In contrast, when the Challenger space shuttle broke apart in 1986, all shuttle debris were buried. These tragic disasters are reminders of the importance of proper material selection and the concern of their performance in service. This research focused on investigating the effects of the debris recovered from the Columbia space shuttle after re-entry and break-up. Many of the components encountered unforeseen extreme temperatures, vibrations, and high stresses. The Columbia debris contained unique characteristics that have yet to be examined and the components for this study are the thermal protection system (TPS) carrier panel tiles and the thermal pane glass from the starboard orbiter Window 7. The alterations endured by the debris was studied through forensic materials characterization to investigate material interactions, material degradation, and thermal consequences. These materials played an essential role in the operation of the orbiter as they protected the underlying structural materials of the shuttle and underwent extreme temperatures. The methods and procedures for analyzing the debris included non-destructive and destructive evaluations. Non-destructive evaluations involved visual inspection, photographic documentation, 3D modeling, and surface elemental composition. The destructive analysis consisted of sectioning, scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy

  3. Composite materials for thermal energy storage: enhancing performance through microstructures.

    Science.gov (United States)

    Ge, Zhiwei; Ye, Feng; Ding, Yulong

    2014-05-01

    Chemical incompatibility and low thermal conductivity issues of molten-salt-based thermal energy storage materials can be addressed by using microstructured composites. Using a eutectic mixture of lithium and sodium carbonates as molten salt, magnesium oxide as supporting material, and graphite as thermal conductivity enhancer, the microstructural development, chemical compatibility, thermal stability, thermal conductivity, and thermal energy storage performance of composite materials are investigated. The ceramic supporting material is essential for preventing salt leakage and hence provides a solution to the chemical incompatibility issue. The use of graphite gives a significant enhancement on the thermal conductivity of the composite. Analyses suggest that the experimentally observed microstructural development of the composite is associated with the wettability of the salt on the ceramic substrate and that on the thermal conduction enhancer. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Composite Materials for Thermal Energy Storage: Enhancing Performance through Microstructures

    Science.gov (United States)

    Ge, Zhiwei; Ye, Feng; Ding, Yulong

    2014-01-01

    Chemical incompatibility and low thermal conductivity issues of molten-salt-based thermal energy storage materials can be addressed by using microstructured composites. Using a eutectic mixture of lithium and sodium carbonates as molten salt, magnesium oxide as supporting material, and graphite as thermal conductivity enhancer, the microstructural development, chemical compatibility, thermal stability, thermal conductivity, and thermal energy storage performance of composite materials are investigated. The ceramic supporting material is essential for preventing salt leakage and hence provides a solution to the chemical incompatibility issue. The use of graphite gives a significant enhancement on the thermal conductivity of the composite. Analyses suggest that the experimentally observed microstructural development of the composite is associated with the wettability of the salt on the ceramic substrate and that on the thermal conduction enhancer. PMID:24591286

  5. Anisotropy Enhancement of Thermal Energy Transport in Supported Black Phosphorene.

    Science.gov (United States)

    Chen, Jige; Chen, Shunda; Gao, Yi

    2016-07-07

    Thermal anisotropy along the basal plane of materials possesses both theoretical importance and application value in thermal transport and thermoelectricity. Though common two-dimensional materials may exhibit in-plane thermal anisotropy when suspended, thermal anisotropy would often disappear when supported on a substrate. In this Letter, we find a strong anisotropy enhancement of thermal energy transport in supported black phosphorene. The chiral preference of energy transport in the zigzag rather than the armchair direction is greatly enhanced by coupling to the substrate, up to a factor of approximately 2-fold compared to the suspended one. The enhancement originates from its puckered lattice structure, where the nonplanar armchair energy transport relies on the out-of-plane corrugation and thus would be hindered by the flexural suppression due to the substrate, while the planar zigzag energy transport is not. As a result, thermal conductivity of supported black phosphorene shows a consistent anisotropy enhancement under different temperatures and substrate coupling strengths.

  6. Flight experiment of thermal energy storage

    Science.gov (United States)

    Namkoong, David

    1989-01-01

    Thermal energy storage (TES) enables a solar dynamic system to deliver constant electric power through periods of sun and shade. Brayton and Stirling power systems under current considerations for missions in the near future require working fluid temperatures in the 1100 to 1300+ K range. TES materials that meet these requirements fall into the fluoride family of salts. These salts store energy as a heat of fusion, thereby transferring heat to the fluid at constant temperature during shade. The principal feature of fluorides that must be taken into account is the change in volume that occurs with melting and freezing. Salts shrink as they solidify, a change reaching 30 percent for some salts. The location of voids that form as result of the shrinkage is critical when the solar dynamic system reemerges into the sun. Hot spots can develop in the TES container or the container can become distorted if the melting salt cannot expand elsewhere. Analysis of the transient, two-phase phenomenon is being incorporated into a three-dimensional computer code. The code is capable of analysis under microgravity as well as 1 g. The objective of the flight program is to verify the predictions of the code, particularly of the void location and its effect on containment temperature. The four experimental packages comprising the program will be the first tests of melting and freezing conducted under microgravity. Each test package will be installed in a Getaway Special container to be carried by the shuttle. The package will be self-contained and independent of shuttle operations other than the initial opening of the container lid and the final closing of the lid. Upon the return of the test package from flight, the TES container will be radiographed and finally partitioned to examine the exact location and shape of the void. Visual inspection of the void and the temperature data during flight will constitute the bases for code verification.

  7. Composite materials for thermal energy storage

    Science.gov (United States)

    Benson, D.K.; Burrows, R.W.; Shinton, Y.D.

    1985-01-04

    A composite material for thermal energy storage based upon polyhydric alcohols, such as pentaerythritol, trimethylol ethane (also known as pentaglycerine), neopentyl glycol and related compounds including trimethylol propane, monoaminopentaerythritol, diamino-pentaerythritol and tris(hydroxymethyl)acetic acid, separately or in combinations, which provide reversible heat storage through crystalline phase transformations. These PCM's do not become liquid during use and are in contact with at least one material selected from the group consisting of metals, carbon, siliceous, plastic, cellulosic, natural fiber, artificial fiber, concrete, gypsum, porous rock, and mixtures thereof. Particulate additions such as aluminum or graphite powders, as well as metal and carbon fibers can also be incorporated therein. Particulate and/or fibrous additions can be introduced into molten phase change materials which can then be cast into various shapes. After the phase change materials have solidified, the additions will remain dispersed throughout the matrix of the cast solid. The polyol is in contact with at least one material selected from the group consisting of metals, carbon, siliceous, plastic, cellulosic, natural fiber, artificial fiber, concrete, gypsum, and mixtures thereof.

  8. The role of Solar thermal in Future Energy Systems

    DEFF Research Database (Denmark)

    Mathiesen, Brian Vad; Hansen, Kenneth

    This report deals with solar thermal technologies and investigates possible roles for solar thermal in future energy systems for four national energy systems; Germany, Austria, Italy and Denmark. The project period started in January 2014 and finished by October 2017. This report is based...

  9. Investigation of Solar and Solar-Gas Thermal Energy Sources

    OpenAIRE

    Ivan Herec; Jan Zupa

    2003-01-01

    The article deals with the investigation of solar thermal sources of electrical and heat energy as well as the investigation of hybrid solar-gas thermal sources of electrical and heat energy (so called photothermal sources). Photothermal sources presented here utilize computer-controlled injection of the conversion fluid into special capillary porous substance that is adjusted to direct temperature treatment by the concentrated thermal radiation absorption.

  10. Microscale solid-state thermal diodes enabling ambient temperature thermal circuits for energy applications.

    Science.gov (United States)

    Wang, Song; Cottrill, Anton L; Kunai, Yuichiro; Toland, Aubrey R; Liu, Pingwei; Wang, Wen-Jun; Strano, Michael S

    2017-05-24

    Thermal diodes, or devices that transport thermal energy asymmetrically, analogous to electrical diodes, hold promise for thermal energy harvesting and conservation, as well as for phononics or information processing. The junction of a phase change material and phase invariant material can form a thermal diode; however, there are limited constituent materials available for a given target temperature, particularly near ambient. In this work, we demonstrate that a micro and nanoporous polystyrene foam can house a paraffin-based phase change material, fused to PMMA, to produce mechanically robust, solid-state thermal diodes capable of ambient operation with Young's moduli larger than 11.5 MPa and 55.2 MPa above and below the melting transition point, respectively. Moreover, the composites show significant changes in thermal conductivity above and below the melting point of the constituent paraffin and rectification that is well-described by our previous theory and the Maxwell-Eucken model. Maximum thermal rectifications range from 1.18 to 1.34. We show that such devices perform reliably enough to operate in thermal diode bridges, dynamic thermal circuits capable of transforming oscillating temperature inputs into single polarity temperature differences - analogous to an electrical diode bridge with widespread implications for transient thermal energy harvesting and conservation. Overall, our approach yields mechanically robust, solid-state thermal diodes capable of engineering design from a mathematical model of phase change and thermal transport, with implications for energy harvesting.

  11. Microscale solid-state thermal diodes enabling ambient temperature thermal circuits for energy applications

    KAUST Repository

    Wang, Song

    2017-05-10

    Thermal diodes, or devices that transport thermal energy asymmetrically, analogous to electrical diodes, hold promise for thermal energy harvesting and conservation, as well as for phononics or information processing. The junction of a phase change material and phase invariant material can form a thermal diode; however, there are limited constituent materials available for a given target temperature, particularly near ambient. In this work, we demonstrate that a micro and nanoporous polystyrene foam can house a paraffin-based phase change material, fused to PMMA, to produce mechanically robust, solid-state thermal diodes capable of ambient operation with Young\\'s moduli larger than 11.5 MPa and 55.2 MPa above and below the melting transition point, respectively. Moreover, the composites show significant changes in thermal conductivity above and below the melting point of the constituent paraffin and rectification that is well-described by our previous theory and the Maxwell–Eucken model. Maximum thermal rectifications range from 1.18 to 1.34. We show that such devices perform reliably enough to operate in thermal diode bridges, dynamic thermal circuits capable of transforming oscillating temperature inputs into single polarity temperature differences – analogous to an electrical diode bridge with widespread implications for transient thermal energy harvesting and conservation. Overall, our approach yields mechanically robust, solid-state thermal diodes capable of engineering design from a mathematical model of phase change and thermal transport, with implications for energy harvesting.

  12. A thermal engine for underwater glider driven by ocean thermal energy

    International Nuclear Information System (INIS)

    Yang, Yanan; Wang, Yanhui; Ma, Zhesong; Wang, Shuxin

    2016-01-01

    Highlights: • Thermal engine with a double-tube structure is developed for underwater glider. • Isostatic pressing technology is effective to increase volumetric change rate. • Actual volumetric change rate reaches 89.2% of the theoretical value. • Long term sailing of 677 km and 27 days is achieved by thermal underwater glider. - Graphical Abstract: - Abstract: Underwater glider is one of the most popular platforms for long term ocean observation. Underwater glider driven by ocean thermal energy extends the duration and range of underwater glider powered by battery. Thermal engine is the core device of underwater glider to harvest ocean thermal energy. In this paper, (1) model of thermal engine was raised by thermodynamics method and the performance of thermal engine was investigated, (2) thermal engine with a double-tube structure was developed and isostatic pressing technology was applied to improve the performance for buoyancy driven, referencing powder pressing theory, (3) wall thickness of thermal engine was optimized to reduce the overall weight of thermal engine, (4) material selection and dimension determination were discussed for a faster heat transfer design, by thermal resistance analysis, (5) laboratory test and long term sea trail were carried out to test the performance of thermal engine. The study shows that volumetric change rate is the most important indicator to evaluating buoyancy-driven performance of a thermal engine, isostatic pressing technology is effective to improve volumetric change rate, actual volumetric change rate can reach 89.2% of the theoretical value and the average power is about 124 W in a typical diving profile. Thermal engine developed by Tianjin University is a superior thermal energy conversion device for underwater glider. Additionally, application of thermal engine provides a new solution for miniaturization of ocean thermal energy conversion.

  13. Method and apparatus for thermal energy storage. [Patent application

    Science.gov (United States)

    Gruen, D.M.

    1975-08-19

    A method and apparatus for storing energy by converting thermal energy to potential chemically bound energy in which a first metal hydride is heated to dissociation temperature, liberating hydrogen gas which is compressed and reacted with a second metal to form a second metal hydride while releasing thermal energy. Cooling the first metal while warming the second metal hydride to dissociation temperature will reverse the flow of hydrogen gas back to the first metal, releasing additional thermal energy. The method and apparatus are particularly useful for the storage and conversion of thermal energy from solar heat sources and for the utilization of this energy for space heating purposes, such as for homes or offices.

  14. Temperature Distribution and Thermal Performance of an Aquifer Thermal Energy Storage System

    Science.gov (United States)

    Ganguly, Sayantan

    2017-04-01

    Energy conservation and storage has become very crucial to make use of excess energy during times of future demand. Excess thermal energy can be captured and stored in aquifers and this technique is termed as Aquifer Thermal Energy Storage (ATES). Storing seasonal thermal energy in water by injecting it into subsurface and extracting in time of demand is the principle of an ATES system. Using ATES systems leads to energy savings, reduces the dependency on fossil fuels and thus leads to reduction in greenhouse gas emission. This study numerically models an ATES system to store seasonal thermal energy and evaluates the performance of it. A 3D thermo-hydrogeological numerical model for a confined ATES system is presented in this study. The model includes heat transport processes of advection, conduction and heat loss to confining rock media. The model also takes into account regional groundwater flow in the aquifer, geothermal gradient and anisotropy in the aquifer. Results show that thermal injection into the aquifer results in the generation of a thermal-front which grows in size with time. Premature thermal-breakthrough causes thermal interference in the system when the thermal-front reaches the production well and consequences in the fall of system performance and hence should be avoided. This study models the transient temperature distribution in the aquifer for different flow and geological conditions. This may be effectively used in designing an efficient ATES project by ensuring safety from thermal-breakthrough while catering to the energy demand. Based on the model results a safe well spacing is proposed. The thermal energy discharged by the system is determined and strategy to avoid the premature thermal-breakthrough in critical cases is discussed. The present numerical model is applied to simulate an experimental field study which is found to approximate the field results quite well.

  15. Hydrogen as an energy carrier and its production by nuclear power

    International Nuclear Information System (INIS)

    1999-05-01

    The impact of power generation on environment is becoming an ever increasing concern in decision making when considering the energy options and power systems required by a country in order to sustain its economic growth and development. Hydrogen is a strong emerging candidate with a significant role as a clean, environmentally benign and safe to handle major energy carrier in the future. Its enhanced utilization in distributed power generation as well as in propulsion systems for mobile applications will help to significantly mitigate the strong negative effects on the environment. It ia also the nuclear power that will be of utmost importance in the energy supply of many countries over the next decades. The development of new, innovative reactor concepts utilizing passive safety features for process heat and electricity generation are considered by many to play a substantial role in the world's energy future in helping to reduce greenhouse gas emissions. This report produced by IAEA documents past and current activities in Member States in the development of hydrogen production as an energy carrier and its corresponding production through the use of nuclear power. It provides an introduction to nuclear technology as a means of producing hydrogen or other upgraded fuels and to the energy carries hydrogen and its main fields of application. Emphasis is placed on high-temperature reactor technology which can achieve the simultaneous generation of electricity and the production of high-temperature process heat

  16. Thermal Energy Storage in Phase Change Material.

    Science.gov (United States)

    1982-03-01

    Graphs of the exnerimental results follow: tney are groupea in the tree categories: tube cross flow, ricked bed, and tube parallel flow. A. Tube Cross... Riordan , Michael, "Thermal Storage: A Rtsic Guile to the Ptate of the Art", Solar Age, Aril, 1978, P. 10. 5. Telkes, Maria, "Thermal Lner y Storage in

  17. Photoswitchable Molecular Rings for Solar-Thermal Energy Storage.

    Science.gov (United States)

    Durgun, E; Grossman, Jeffrey C

    2013-03-21

    Solar-thermal fuels reversibly store solar energy in the chemical bonds of molecules by photoconversion, and can release this stored energy in the form of heat upon activation. Many conventional photoswichable molecules could be considered as solar thermal fuels, although they suffer from low energy density or short lifetime in the photoinduced high-energy metastable state, rendering their practical use unfeasible. We present a new approach to the design of chemistries for solar thermal fuel applications, wherein well-known photoswitchable molecules are connected by different linker agents to form molecular rings. This approach allows for a significant increase in both the amount of stored energy per molecule and the stability of the fuels. Our results suggest a range of possibilities for tuning the energy density and thermal stability as a function of the type of the photoswitchable molecule, the ring size, or the type of linkers.

  18. Solar-thermal conversion and thermal energy storage of graphene foam-based composites.

    Science.gov (United States)

    Zhang, Lianbin; Li, Renyuan; Tang, Bo; Wang, Peng

    2016-08-14

    Among various utilizations of solar energy, solar-thermal conversion has recently gained renewed research interest due to its extremely high energy efficiency. However, one limiting factor common to all solar-based energy conversion technologies is the intermittent nature of solar irradiation, which makes them unable to stand-alone to satisfy the continuous energy need. Herein, we report a three-dimensional (3D) graphene foam and phase change material (PCM) composite for the seamlessly combined solar-thermal conversion and thermal storage for sustained energy release. The composite is obtained by infiltrating the 3D graphene foam with a commonly used PCM, paraffin wax. The high macroporosity and low density of the graphene foam allow for high weight fraction of the PCM to be incorporated, which enhances the heat storage capacity of the composite. The interconnected graphene sheets in the composite provide (1) the solar-thermal conversion capability, (2) high thermal conductivity and (3) form stability of the composite. Under light irradiation, the composite effectively collects and converts the light energy into thermal energy, and the converted thermal energy is stored in the PCM and released in an elongated period of time for sustained utilization. This study provides a promising route for sustainable utilization of solar energy.

  19. Solar-thermal conversion and thermal energy storage of graphene foam-based composite

    KAUST Repository

    Zhang, Lianbin

    2016-07-11

    Among various utilizations of solar energy, solar-thermal conversion has recently gained renewed research interest due to its extremely high energy efficiency. However, one limiting factor common to all solar-based energy conversion technologies is the intermittent nature of solar irradiation, which makes them unable to stand-alone to satisfy continuous energy need. Herein, we report a three-dimensional (3D) graphene foam and phase change material (PCM) composite for the seamlessly combined solar-thermal conversion and thermal storage for sustained energy release. The composite is obtained by infiltrating the 3D graphene foam with a commonly used PCM, paraffin wax. The high macroporosity and low density of the graphene foam allow for high weight fraction of the PCM to be incorporated, which enhances heat storage capacity of the composite. The interconnected graphene sheets in the composite provide (1) the solar-thermal conversion capability, (2) high thermal conductivity and (3) form stability of the composite. Under light irradiation, the composite effectively collects and converts the light energy into thermal energy, and the converted thermal energy is stored in the PCM and released in an elongated period of time for sustained utilization. This study provides a promising route for sustainable utilization of solar energy.

  20. Building heating and cooling applications thermal energy storage program overview

    Science.gov (United States)

    Eissenberg, D. M.

    1980-01-01

    Thermal energy storage technology and development of building heating and cooling applications in the residential and commercial sectors is outlined. Three elements are identified to undergo an applications assessment, technology development, and demonstration. Emphasis is given to utility load management thermal energy system application where the stress is on the 'customer side of the meter'. Thermal storage subsystems for space conditioning and conservation means of increased thermal mass within the building envelope and by means of low-grade waste heat recovery are covered.

  1. Current and future competitiveness of renewable energy carriers - Conceptions about competitiveness

    International Nuclear Information System (INIS)

    Lundgren, K.

    1998-01-01

    The dissertation draws attention to the fact that in the world today 80% of the resources that are used are limited - non renewable energy carriers - and because of the long time between planning and doing (carrying out) within the energy sector, it is worthwhile from the long-term perspective to steer early on towards more sustainable solutions, such as renewable energy carriers. The State and the market have begun to adjust to concepts such as 'competitiveness', which can be viewed as containing both feasibility and legitimacy aspects - the state through different regulations and environmental taxes and environmental fees, and actors on the market that marginally produce/choose renewable energy carriers. The overlying methodology in the dissertation is an actor's viewpoint. This viewpoint brings forth, in turn, two different views, the analytical and the interpretative. The dissertation presents different stances within the energy sector: commercial production logic, commercial sustainability logic, and the socio-economic sustainability logic. By drawing one's attention to how one has the possibility to create (enact) his own reality, it is possible to highlight how organisations can increase their competitiveness by being conscious of their own view and others, logic, which in turn forms their views about competitiveness, which in turn determines which projects will materialize. Enterprises and individuals create a description of reality together through a dialectic process, i.e. by developing an environmental management system that contains elements of environmental auditing, environmental performance indicators, and environmental labelling, which 'reveal' the production conditions that lie behind the actualization of the final product. An example is the product, 'green' electricity, which, in spite of the fact that the final product - electricity - is identical irrespective of the production method, just at the moment can be sold at different prices according

  2. Thermal energy dissipation and xanthophyll cycles beyond the Arabidopsis model.

    Science.gov (United States)

    García-Plazaola, José Ignacio; Esteban, Raquel; Fernández-Marín, Beatriz; Kranner, Ilse; Porcar-Castell, Albert

    2012-09-01

    Thermal dissipation of excitation energy is a fundamental photoprotection mechanism in plants. Thermal energy dissipation is frequently estimated using the quenching of the chlorophyll fluorescence signal, termed non-photochemical quenching. Over the last two decades, great progress has been made in the understanding of the mechanism of thermal energy dissipation through the use of a few model plants, mainly Arabidopsis. Nonetheless, an emerging number of studies suggest that this model represents only one strategy among several different solutions for the environmental adjustment of thermal energy dissipation that have evolved among photosynthetic organisms in the course of evolution. In this review, a detailed analysis of three examples highlights the need to use models other than Arabidopsis: first, overwintering evergreens that develop a sustained form of thermal energy dissipation; second, desiccation tolerant plants that induce rapid thermal energy dissipation; and third, understorey plants in which a complementary lutein epoxide cycle modulates thermal energy dissipation. The three examples have in common a shift from a photosynthetically efficient state to a dissipative conformation, a strategy widely distributed among stress-tolerant evergreen perennials. Likewise, they show a distinct operation of the xanthophyll cycle. Expanding the list of model species beyond Arabidopsis will enhance our knowledge of these mechanisms and increase the synergy of the current studies now dispersed over a wide number of species.

  3. Determination of the polarity of carrier traps in γ-irradiated polyethylene by temperature gradient thermally stimulated current

    International Nuclear Information System (INIS)

    Kato, Keizo; Iwamoto, Mitsumasa; Hino, Taro

    1986-01-01

    Theoretical analysis is made to show that the polarity of carrier traps produced by radiation can be determined based on measurements of temperature gradient thremally stimulated current. Observations are also made on γ-irradiated polyethylene to examine the polarity of carrier traps. Another investigation is conducted to determine whether a space-charge field is generated in the γ-irradiated polyethylene. In the apparatus used, a collecting voltage is applied to a γ-irradiated specimen to heat it under a temperature gradient while the current generated in an enternal circuit is measured. Theoretical examination, conducted concerning this temperature gradient thermally stimulated current, shows that polarity determination is possible under some conditions. Then, observation is actually carried out using γ-irradiated low-density polyethylene films with deposited gold electrodes. Characteristics of initial rise in thermally stimulated current and effects of the collecting voltage are examined. The polyethylene investigated shows a maximum in thermally stimulated current at about 80 deg C, which is found to have relations with electron traps. It is also revealed that space-charge field is not generated in the sample examined. (Nogami, K.)

  4. Alternative biomass sources for thermal energy generation

    Science.gov (United States)

    Steensen, Torge; Müller, Sönke; Dresen, Boris; Büscher, Olaf

    2015-04-01

    of Bottrop-Kirchhellen in the state of North Rhine-Westphalia. This region consists of nature reserves, forests, farmland and a few villages. To present a qualitative comparison between simulated and true biomass volume, we conducted field work by mapping the spatial extent of the desired biomass occurrences in the area. First results indicate a qualitative match of about 75%. Our research highlights the small-scale biomass features that have not been incorporated in previous biomass estimates. With the regular trimming and the accompanied raw material that becomes available, a new sector of thermal energy generation can be outlined. An automated quantification using satellite and GIS data will allow a regular monitoring of the vegetation growth and an assessment of the transport routes and costs as well as the location of the prospective power plants. In the endeavour of creating a sustainable energy supply, these biomass units should not be neglected, especially since the usage of the traditional units is limited due to competing interests in food production and nature conservation.

  5. Substitute Energy Carriers from Refinement of Coal using HTR-Module

    International Nuclear Information System (INIS)

    Barnert, Heiko; Kugeler, Kurt; Will, Michael

    2014-01-01

    There is a revival of coal refinement in the world: a recent press article in Germany titled “The Renaissance of Coal Refinement”. It reports about a large number of conventional plans and plants for coal refinement in many countries in the world, and in particular in China. Nuclear energy can be of assistance, in particular the High Temperature Reactor-Module, because it offers all needed process energies. The status of the research, development, and demonstration, RDD, of technology is summarized, in particular of the former programs in Germany: The primary energy carriers were hard coal and lignite. The envisaged products were: Substitute Natural Gas, SNG, for the gas market, Hydrogen, H2, for a future H2-market, e.g. for airplane traffic, Liquid Fuels, as Substitute Gasoline, or as Energy Alcohol, e.g. Methanol CH3OH, in mixture with higher alcohols, for the car traffic and for home heating. (author)

  6. Thermal activated carrier transfer between InAs quantum dots in very low density samples

    Energy Technology Data Exchange (ETDEWEB)

    MartInez-Pastor, J P; Munoz-Matutano, G; Canet-Ferrer, J; Fuster, D [Instituto de Ciencias de los Materiales, Universitat de Valencia, POBox 22085, 46071 Valencia (Spain); Alen, B [Instituto de Microelectronica de Madrid (IMM-CNM-CSIC), Isaac Newton 8, E-28760, Tres Cantos Madrid (Spain); Trevisi, G; Seravalli, L; Frigeri, P; Franchi, S, E-mail: Juan.Mtnez.Pastor@uv.e [CNR-IMEM Institute, Parco delle Scienze 37a, I-43100 Parma (Italy)

    2010-02-01

    In this work we develop a detailed experimental study of the exciton recombination dynamics as a function of temperature on QD-ensembles and single QDs in two low density samples having 16.5 and 25 dots/{mu}m{sup 2}. We corroborate at the single QD level the limitation of the exciton recombination time in the smallest QDs of the distribution by thermionic emission (electron emission in transient conditions). A portion of these emitted carriers is retrapped again in other (larger) QDs, but not very distant from those emitting the carriers, because the process is limited by the diffusion length at the considered temperature.

  7. Hot Thermal Storage in a Variable Power, Renewable Energy System

    Science.gov (United States)

    2014-06-01

    This thesis outlines the design of a renewable energy heat generation system with thermal storage for DOD facilities. The DOD is seeking to implement...an increased percentage of renewable energy systems at its facilities in order to improve energy security and reduce energy costs. The intermittent...nature of renewable energy generation, however, presents a major challenge to full implementation. This shortfall can be overcome by targeted facility

  8. Passive Collecting of Solar Radiation Energy using Transparent Thermal Insulators, Energetic Efficiency of Transparent Thermal Insulators

    Directory of Open Access Journals (Sweden)

    Smajo Sulejmanovic

    2014-11-01

    Full Text Available This paper explains passive collection of solar radiation energy using transparent thermal insulators. Transparent thermal insulators are transparent for sunlight, at the same time those are very good thermal insulators. Transparent thermal insulators can be placed instead of standard conventional thermal insulators and additionally transparent insulators can capture solar radiation, transform it into heat and save heat just as standard insulators. Using transparent insulators would lead to reduce in usage of fossil fuels and would help protection of an environment and reduce effects of global warming, etc.

  9. Buffer thermal energy storage for an air Brayton solar engine

    Science.gov (United States)

    Strumpf, H. J.; Barr, K. P.

    1981-01-01

    The application of latent-heat buffer thermal energy storage to a point-focusing solar receiver equipped with an air Brayton engine was studied. To demonstrate the effect of buffer thermal energy storage on engine operation, a computer program was written which models the recuperator, receiver, and thermal storage device as finite-element thermal masses. Actual operating or predicted performance data are used for all components, including the rotating equipment. Based on insolation input and a specified control scheme, the program predicts the Brayton engine operation, including flows, temperatures, and pressures for the various components, along with the engine output power. An economic parametric study indicates that the economic viability of buffer thermal energy storage is largely a function of the achievable engine life.

  10. Analysis on energy consumption index system of thermal power plant

    Science.gov (United States)

    Qian, J. B.; Zhang, N.; Li, H. F.

    2017-05-01

    Currently, the increasingly tense situation in the context of resources, energy conservation is a realistic choice to ease the energy constraint contradictions, reduce energy consumption thermal power plants has become an inevitable development direction. And combined with computer network technology to build thermal power “small index” to monitor and optimize the management system, the power plant is the application of information technology and to meet the power requirements of the product market competition. This paper, first described the research status of thermal power saving theory, then attempted to establish the small index system and build “small index” monitoring and optimization management system in thermal power plant. Finally elaborated key issues in the field of small thermal power plant technical and economic indicators to be further studied and resolved.

  11. Thermoelectric cooling in combination with photovoltaics and thermal energy storage

    Directory of Open Access Journals (Sweden)

    Skovajsa Jan

    2017-01-01

    Full Text Available The article deals with the use of modern technologies that can improve the thermal comfort in buildings. The article describes the usage of thermal energy storage device based on the phase change material (PCM. The technology improves the thermal capacity of the building and it is possible to use it for active heating and cooling. It is designed as a “green technology” so it is able to use renewable energy sources, e.g., photovoltaic panels, solar thermal collectors, and heat pump. Moreover, an interesting possibility is the ability to use thermal energy storage in combination with a photovoltaic system and thermoelectric coolers. In the research, there were made measurements of the different operating modes and the results are presented in the text.

  12. Study of thermally coupled distillation systems for energy-efficient ...

    Indian Academy of Sciences (India)

    ponent mixtures. Int. J. Chem. Eng. 5(3): 555–561. [5] Fidkowski Z and Krolikowski L 1987 Minimum energy requirements for thermally coupled distillation systems. AIChE J. 33(4): 643–653. [6] Amminudin K A, Smith R, Thong D Y C and Towler G. P 2001 Design and optimization of fully thermally coupled distillation columns ...

  13. Thermogravimetry as a Research Method in the Transformation Processes of Waste Rubber and Plastic Products for Energy Carriers (WtE and WtL Processes

    Directory of Open Access Journals (Sweden)

    Ewa Rostek

    2013-06-01

    Full Text Available The paper describes the basic problems regarding the possibility of using waste plastics and tire rubber waste as raw materials for the preparation of liquid energy carriers for transport (WtL processes or directly to energy use in a WtE. Simultaneous measurements were performed at Thermal Analyzer STA 449 F3 Jupiter's (Netzsch. The study was conducted for waste samples of different density polyethylene, polyethylene terephthalate and rubber from waste tires. Gasification process of subjecting the sample was recorded TG and DSC curve, observing changes in mass, temperature and enthalpy. These studies were carried out in order to pre-determine the kinetics of thermal decomposition. The study, conducted in an atmosphere of argon/nitrogen (non-oxidizing atmosphere, both in terms of the changes of enthalpy and mass are summarized in the respective charts.

  14. Making Heat Visible: Promoting Energy Conservation Behaviors Through Thermal Imaging.

    Science.gov (United States)

    Goodhew, Julie; Pahl, Sabine; Auburn, Tim; Goodhew, Steve

    2015-12-01

    Householders play a role in energy conservation through the decisions they make about purchases and installations such as insulation, and through their habitual behavior. The present U.K. study investigated the effect of thermal imaging technology on energy conservation, by measuring the behavioral effect after householders viewed images of heat escaping from or cold air entering their homes. In Study 1 ( n = 43), householders who received a thermal image reduced their energy use at a 1-year follow-up, whereas householders who received a carbon footprint audit and a non-intervention control demonstrated no change. In Study 2 ( n = 87), householders were nearly 5 times more likely to install draught proofing measures after seeing a thermal image. The effect was especially pronounced for actions that addressed an issue visible in the images. Findings indicate that using thermal imaging to make heat loss visible can promote energy conservation.

  15. Concrete thermal energy storage for steam generation: A numerical investigation

    DEFF Research Database (Denmark)

    Singh, Shobhana; Sørensen, Kim

    2017-01-01

    the heat exchanger tubes embedded in a cylindrical shape concrete configuration. Three-dimensional multiphysics model of the storage system is developed to investigate transient conjugate heat transfer between the two mediums, the heat transfer fluid, and the concrete. The model comprehends the dynamics...... of storing thermal energy in the storage at the temperature range of 350??390 C. To evaluate the performance of the storage system using finned heat exchanger tubes, thermal characteristics such as charging/discharging time, energy, and exergy efficiency are predicted. The developed model satisfactorily......Establishing enhancement methods to develop cost-effective thermal energy storage technology requires a detailed analysis. In this paper, a numerical investigation of the concrete based thermal energy storage system is carried out. The storage system consists of a heat transfer fluid flowing inside...

  16. Solar thermal energy utilization: A bibliography with abstracts

    Science.gov (United States)

    1976-01-01

    Bibliographic series, which is periodically updated, cites documents published since 1957 relating to practical thermal utilization of solar energy. Bibliography is indexed by author, corporate source, title, and keywords.

  17. Potential energy savings and thermal comfort

    DEFF Research Database (Denmark)

    Jensen, Karsten Ingerslev; Rudbeck, Claus Christian; Schultz, Jørgen Munthe

    1996-01-01

    Results of simulations carried out on four different buildings with common windows, commercial low-energy windows and xerogel windows are presented. The results are the annual energy consumption for space heating and the indoor air temperature level.......Results of simulations carried out on four different buildings with common windows, commercial low-energy windows and xerogel windows are presented. The results are the annual energy consumption for space heating and the indoor air temperature level....

  18. Energy consumption in buildings and female thermal demand

    Science.gov (United States)

    Kingma, Boris; van Marken Lichtenbelt, Wouter

    2015-12-01

    Energy consumption of residential buildings and offices adds up to about 30% of total carbon dioxide emissions; and occupant behaviour contributes to 80% of the variation in energy consumption. Indoor climate regulations are based on an empirical thermal comfort model that was developed in the 1960s (ref. ). Standard values for one of its primary variables--metabolic rate--are based on an average male, and may overestimate female metabolic rate by up to 35% (ref. ). This may cause buildings to be intrinsically non-energy-efficient in providing comfort to females. Therefore, we make a case to use actual metabolic rates. Moreover, with a biophysical analysis we illustrate the effect of miscalculating metabolic rate on female thermal demand. The approach is fundamentally different from current empirical thermal comfort models and builds up predictions from the physical and physiological constraints, rather than statistical association to thermal comfort. It provides a substantiation of the thermal comfort standard on the population level and adds flexibility to predict thermal demand of subpopulations and individuals. Ultimately, an accurate representation of thermal demand of all occupants leads to actual energy consumption predictions and real energy savings of buildings that are designed and operated by the buildings services community.

  19. Laser energy tuning of carrier effective mass and thermopower in epitaxial oxide thin films

    KAUST Repository

    Abutaha, Anas I.

    2012-04-18

    The effect of the laser fluence on high temperature thermoelectric properties of the La doped SrTiO3 (SLTO) thin films epitaxially grown on LaAlO3 〈100〉 substrates by pulsed laser deposition is clarified. It is shown that oxygen vacancies that influence the effective mass of carriers in SLTO films can be tuned by varying the laser energy. The highest power factor of 0.433 W K−1 m−1 has been achieved at 636 K for a filmdeposited using the highest laser fluence of 7 J cm−2 pulse−1.

  20. Pulse thermal energy transport/storage system

    Science.gov (United States)

    Weislogel, Mark M.

    1992-07-07

    A pulse-thermal pump having a novel fluid flow wherein heat admitted to a closed system raises the pressure in a closed evaporator chamber while another interconnected evaporator chamber remains open. This creates a large pressure differential, and at a predetermined pressure the closed evaporator is opened and the opened evaporator is closed. This difference in pressure initiates fluid flow in the system.

  1. Aquifer thermal energy storage reference manual: seasonal thermal energy storage program

    Energy Technology Data Exchange (ETDEWEB)

    Prater, L.S.

    1980-01-01

    This is the reference manual of the Seasonal Thermal Energy Storage (STES) Program, and is the primary document for the transfer of technical information of the STES Program. It has been issued in preliminary form and will be updated periodically to include more technical data and results of research. As the program progresses and new technical data become available, sections of the manual will be revised to incorporate these data. This primary document contains summaries of: the TRW, incorporated demonstration project at Behtel, Alaska, Dames and Moore demonstration project at Stony Brook, New York, and the University of Minnesota demonstration project at Minneapolis-St. Paul, Minnesota; the technical support programs including legal/institutional assessment; economic assessment; environmental assessment; field test facilities; a compendia of existing information; numerical simulation; and non-aquifer STES concepts. (LCL)

  2. Smart Building: Decision Making Architecture for Thermal Energy Management.

    Science.gov (United States)

    Uribe, Oscar Hernández; Martin, Juan Pablo San; Garcia-Alegre, María C; Santos, Matilde; Guinea, Domingo

    2015-10-30

    Smart applications of the Internet of Things are improving the performance of buildings, reducing energy demand. Local and smart networks, soft computing methodologies, machine intelligence algorithms and pervasive sensors are some of the basics of energy optimization strategies developed for the benefit of environmental sustainability and user comfort. This work presents a distributed sensor-processor-communication decision-making architecture to improve the acquisition, storage and transfer of thermal energy in buildings. The developed system is implemented in a near Zero-Energy Building (nZEB) prototype equipped with a built-in thermal solar collector, where optical properties are analysed; a low enthalpy geothermal accumulation system, segmented in different temperature zones; and an envelope that includes a dynamic thermal barrier. An intelligent control of this dynamic thermal barrier is applied to reduce the thermal energy demand (heating and cooling) caused by daily and seasonal weather variations. Simulations and experimental results are presented to highlight the nZEB thermal energy reduction.

  3. On the Non-Thermal Energy Content of Cosmic Structures

    Directory of Open Access Journals (Sweden)

    Franco Vazza

    2016-11-01

    Full Text Available (1 Background: the budget of non-thermal energy in galaxy clusters is not well constrained, owing to the observational and theoretical difficulties in studying these diluted plasmas on large scales; (2 Method: we use recent cosmological simulations with complex physics in order to connect the emergence of non-thermal energy to the underlying evolution of gas and dark matter; (3 Results: the impact of non-thermal energy (e.g., cosmic rays, magnetic fields and turbulent motions is found to increase in the outer region of galaxy clusters. Within numerical and theoretical uncertainties, turbulent motions dominate the budget of non-thermal energy in most of the cosmic volume; (4 Conclusion: assessing the distribution non-thermal energy in galaxy clusters is crucial to perform high-precision cosmology in the future. Constraining the level of non-thermal energy in cluster outskirts will improve our understanding of the acceleration of relativistic particles and of the origin of extragalactic magnetic fields.

  4. Carrier-envelope phase dependent photoelectron energy spectra in low intensity regime.

    Science.gov (United States)

    Li, Yang; Li, Min; Zhou, Yueming; Ma, Xiaomeng; Xie, Hui; Lan, Pengfei; Lu, Peixiang

    2017-05-15

    We study the carrier-envelope phase (CEP) dependent photoelectron energy spectra from above-threshold ionization by numerically solving the time-dependent Schrödinger equation of hydrogen atom in a few-cycle laser field at intensities in the range of (2-10) × 10 13 W/cm 2 . Depending on the electron energy and the laser intensity, the yield of the photoelectron reveals clear oscillations with respect to the CEP. At high laser intensities (larger than ~3 × 10 13 W/cm 2 ), the yield of the high-energy photoelectrons (larger than 2U p , with U p being the ponderomotive potential) shows two kinds of oscillations with the CEP for different electron energies. There is a clear phase jump for those two kinds of oscillations. In contrast, at low laser intensities (smaller than ~3 × 10 13 W/cm 2 ), the phase of the oscillation for the high-energy photoelectron yield with the CEP is nearly independent on the electron energy, which will reduce the sensitivity of the retrieval of single-shot CEP using the method reported by T. Wittmann et al. [Nat. Phys. 5, 357 (2009)] at low laser intensities. We further show that the low-energy photoelectrons display distinct CEP-dependent intercycle interference fringes, providing an alternative approach to retrieve the CEP with high sensitivity in a few-cycle laser field with low intensity.

  5. Thermodynamic limits of energy harvesting from outgoing thermal radiation.

    Science.gov (United States)

    Buddhiraju, Siddharth; Santhanam, Parthiban; Fan, Shanhui

    2018-04-17

    We derive the thermodynamic limits of harvesting power from the outgoing thermal radiation from the ambient to the cold outer space. The derivations are based on a duality relation between thermal engines that harvest solar radiation and those that harvest outgoing thermal radiation. In particular, we derive the ultimate limit for harvesting outgoing thermal radiation, which is analogous to the Landsberg limit for solar energy harvesting, and show that the ultimate limit far exceeds what was previously thought to be possible. As an extension of our work, we also derive the ultimate limit of efficiency of thermophotovoltaic systems.

  6. Modelling and monitoring of Aquifer Thermal Energy Storage : impacts of soil heterogeneity, thermal interference and bioremediation

    NARCIS (Netherlands)

    Sommer, W.T.

    2015-01-01

    Modelling and monitoring of Aquifer Thermal Energy Storage

    Impacts of heterogeneity, thermal interference and bioremediation

    Wijbrand Sommer
    PhD thesis, Wageningen University, Wageningen, NL (2015)
    ISBN 978-94-6257-294-2

    Abstract

    Aquifer

  7. Guide to Setting Thermal Comfort Criteria and Minimizing Energy Use in Delivering Thermal Comfort

    Energy Technology Data Exchange (ETDEWEB)

    Regnier, Cindy [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-08-01

    Historically thermal comfort in buildings has been controlled by simple dry bulb temperature settings. As we move into more sophisticated low energy building systems that make use of alternate systems such as natural ventilation, mixed mode system and radiant thermal conditioning strategies, a more complete understanding of human comfort is needed for both design and control. This guide will support building designers, owners, operators and other stakeholders in defining quantifiable thermal comfort parameters?these can be used to support design, energy analysis and the evaluation of the thermal comfort benefits of design strategies. This guide also contains information that building owners and operators will find helpful for understanding the core concepts of thermal comfort. Whether for one building, or for a portfolio of buildings, this guide will also assist owners and designers in how to identify the mechanisms of thermal comfort and space conditioning strategies most important for their building and climate, and provide guidance towards low energy design options and operations that can successfully address thermal comfort. An example of low energy design options for thermal comfort is presented in some detail for cooling, while the fundamentals to follow a similar approach for heating are presented.

  8. High Density Thermal Energy Storage with Supercritical Fluids

    Science.gov (United States)

    Ganapathi, Gani B.; Wirz, Richard

    2012-01-01

    A novel approach to storing thermal energy with supercritical fluids is being investigated, which if successful, promises to transform the way thermal energy is captured and utilized. The use of supercritical fluids allows cost-affordable high-density storage with a combination of latent heat and sensible heat in the two-phase as well as the supercritical state. This technology will enhance penetration of several thermal power generation applications and high temperature water for commercial use if the overall cost of the technology can be demonstrated to be lower than the current state-of-the-art molten salt using sodium nitrate and potassium nitrate eutectic mixtures.

  9. 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)

  10. CALORSTOCK'94. Thermal energy storage. Better economy, environment, technology

    International Nuclear Information System (INIS)

    Kangas, M.T.; Lund, P.D.

    1994-01-01

    This publication is the first volume of the proceedings of CALORSTOCK'94, the sixth international conference on thermal energy storage held in Espoo, Finland on August 22-25, 1994. This volume contains 58 presentations from the following six sessions: Aquifer storage, integration into energy systems, Simulation models and design tools, IEA energy conservation through energy storage programme workshop, Earth coupled storage, District heating and utilities

  11. Technology data for energy plants. Generation of electricity and district heating, energy storage and energy carrier generation and conversion

    Energy Technology Data Exchange (ETDEWEB)

    2012-05-15

    The Danish Energy Agency and Energinet.dk, the Danish electricity transmission and system operator, have at regular intervals published a catalogue of energy producing technologies. The previous edition was published in June 2010. This report presents the results of the most recent update. The primary objective of publishing a technology catalogue is to establish a uniform, commonly accepted and up-to-date basis for energy planning activities, such as future outlooks, evaluations of security of supply and environmental impacts, climate change evaluations, and technical and economic analyses, e.g. on the framework conditions for the development and deployment of certain classes of technologies. With this scope in mind, it has not been the intention to establish a comprehensive catalogue, including all main gasification technologies or all types of electric batteries. Only selected, representative, technologies are included, to enable generic comparisons of e.g. thermal gasification versus combustion of biomass and electricity storage in batteries versus hydro-pumped storage. It has finally been the intention to offer the catalogue for the international audience, as a contribution to similar initiatives aiming at forming a public and concerted knowledge base for international analyses and negotiations. A guiding principle for developing the catalogue has been to rely primarily on well-documented and public information, secondarily on invited expert advice. Since many experts are reluctant in estimating future quantitative performance data, the data tables are not complete, in the sense that most data tables show several blank spaces. This approach has been chosen in order to achieve data, which to some extent are equivalently reliable, rather than to risk a largely incoherent data set including unfounded guesstimates. The current update has been developed with an unbalanced focus, i.e. most attention to technologies which are most essential for current and short

  12. Thermal desorption of toluene from Vanadium-containing catalysts coated onto various carriers

    Directory of Open Access Journals (Sweden)

    Z. Zheksenbaeva

    2012-12-01

    Full Text Available The method temperature-programmed desorption has been studied the state of toluene on the surface-modified vanadium catalysts on different carriers. Among the investigated carriers the most active in the reaction of partial oxidation of toluene is anatase structural titanium dioxide. For the partial oxidation of toluene on modified vanadium-containing catalysts deposited on TiO2 was tested. It was found that on the catalyst 20%V2O5-5%MoO3-2%Sb2O3/TiO2 at a temperature of 673K, volume rate of 15 thousand hours-1 oxidation of toluene is 80% c yield of benzoic acid with a selectivity of  70% of 87.5%.

  13. Geothermal energy enhancement by thermal fracture. [REX (Rock Energy Extraction)

    Energy Technology Data Exchange (ETDEWEB)

    Demuth, R.B.; Harlow, F.H.

    1980-12-01

    A large, vertical, circular fracture created deep within hot rock is connected to the surface through two holes. The inlet provides a source of cold water and the outlet extracts heated water. Cooling of the rock produces thermal stresses that fracture the rock adjacent to the primary crack, thereby enhancing the heat extraction rate by means of convective transport. The properties of the thermal fracture network vary with position and time. The REX code for high-speed computer was written and used to study the coupled processes of primary-crack flow and lateral thermal fracture heat transport. Calculations for elapsed times of 100 y show that thermal fracture enhancement can double the heat extraction rate over the results from conduction alone. Long-term enhancement predictions depend on data from rock-mechanics studies, which the REX code is prepared to accept as they become available.

  14. Implosive Thermal Plasma Source for Energy Conversion

    Czech Academy of Sciences Publication Activity Database

    Šonský, Jiří; Tesař, Václav; Gruber, Jan; Mašláni, Alan

    2017-01-01

    Roč. 4, č. 1 (2017), s. 87-90 ISSN 2336-2626 Institutional support: RVO:61388998 ; RVO:61389021 Keywords : implosion * thermal plasma * detonation wave Subject RIV: BL - Plasma and Gas Discharge Physics; BL - Plasma and Gas Discharge Physics (UFP-V) OBOR OECD: Fluids and plasma physics (including surface physics); Fluids and plasma physics (including surface physics) (UFP-V) https://ppt.fel.cvut.cz/ppt2017.html#number1

  15. Rapid charging of thermal energy storage materials through plasmonic heating.

    Science.gov (United States)

    Wang, Zhongyong; Tao, Peng; Liu, Yang; Xu, Hao; Ye, Qinxian; Hu, Hang; Song, Chengyi; Chen, Zhaoping; Shang, Wen; Deng, Tao

    2014-09-01

    Direct collection, conversion and storage of solar radiation as thermal energy are crucial to the efficient utilization of renewable solar energy and the reduction of global carbon footprint. This work reports a facile approach for rapid and efficient charging of thermal energy storage materials by the instant and intense photothermal effect of uniformly distributed plasmonic nanoparticles. Upon illumination with both green laser light and sunlight, the prepared plasmonic nanocomposites with volumetric ppm level of filler concentration demonstrated a faster heating rate, a higher heating temperature and a larger heating area than the conventional thermal diffusion based approach. With controlled dispersion, we further demonstrated that the light-to-heat conversion and thermal storage properties of the plasmonic nanocomposites can be fine-tuned by engineering the composition of the nanocomposites.

  16. Investigation of lithium sulphate for high temperature thermal energy storage

    Science.gov (United States)

    Bayon, Alicia; Liu, Ming; Bruno, Frank; Hinkley, Jim

    2017-06-01

    Lithium sulphate (Li2SO4) was evaluated as a solid-solid PCM material to be coupled with concentrated solar power (CSP) technologies. The energy is stored in a cubic crystalline phase that is formed at temperatures above 576°C and can potentially be discharged at temperatures as low as 150°C, providing both sensible and latent thermal energy storage in a hybrid sensible-latent system. These operational conditions are appropriate for current CSP technologies based on subcritical steam Rankine power cycles. Results from thermal cycling experiments in air showed no change in energy storage capacity after 15 cycles. There was up to a 5% reduction in latent thermal capacity and 0.95% in total thermal capacity after 150 cycles in air. In our paper, we evaluate a hybrid sensible-latent thermal energy storage system based on lithium sulphate from an economic and technical performance point of view, demonstrating its potential as a high temperature thermal energy storage material.

  17. Energy flow and thermal comfort in buildings

    DEFF Research Database (Denmark)

    Le Dreau, Jerome

    is based on both radiation and convection. Radiant terminals have the advantage of making use of low grade sources (i.e. low temperature heating and high temperature cooling), thus decreasing the primary energy consumption of buildings. But there is a lack of knowledge on the heat transfer from...... the terminal towards the space and on the parameters influencing the effectiveness of terminals. Therefore the comfort conditions and energy consumption of four types of terminals (active chilled beam, radiant floor, wall and ceiling) have been compared for a typical office room, both numerically......), radiant and air-based terminals have similar energy needs. For higher air change rate, the energy consumption of radiant terminals is lower than that of air-based terminals due to the higher air temperature. At 2 ACH, the energy savings of a radiant wall can be estimated to around 10 % compared...

  18. Preparation, thermal properties and thermal reliability of microencapsulated n-eicosane as novel phase change material for thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Alkan, Cemil; Sari, Ahmet; Karaipekli, Ali [Department of Chemistry, Gaziosmanpasa University, 60240 Tokat (Turkey)

    2011-01-15

    This study deals with preparation, characterization, thermal properties and thermal reliability of n-eicosane microcapsules as novel phase change material (PCM) for thermal energy storage. The microcapsulated PCMs were prepared by coating n-eicosane with polymethylmethacrylate (PMMA) shell. Fourier transform infrared (FT-IR), scanning electron microscope (SEM) and particle size distribution (PSD) analysis were used to characterize the PMMA/eicosane microcapsules as microcapsulated PCMs. The PSD analysis indicated that the average diameter of microcapsules was found to be 0.70 {mu}m under the stirring speed of 2000 rpm. Thermal properties and thermal reliability of the microcapsules were determined using differential scanning calorimetry (DSC) and thermo gravimetric analysis (TGA) methods. From DSC analysis, the melting and freezing temperatures and the latent heats of the microcapsules were measured as 35.2 C and 34.9 C, 84.2 and -87.5 J/g, respectively. TGA analysis indicated that PMMA/eicosane microcapsules degrade in three steps at considerably high temperatures. Accelerated thermal cycling tests have been also applied to show the thermal reliability of the microcapsules. All results showed that thermal properties make the PMMA/eicosane microcapsules potential PCM for thermal energy storage. (author)

  19. Energy Aspects of Thermal Molecular Switching: Molecular Thermal Hysteresis of Helicene Oligomers.

    Science.gov (United States)

    Shigeno, Masanori; Kushida, Yo; Yamaguchi, Masahiko

    2015-07-20

    Molecular switching is a phenomenon by which a molecule reversibly changes its structure and state in response to external stimuli or energy. Herein, molecular switching is discussed from thermodynamic and kinetic aspects in terms of energy supply with an emphasis on the thermal switching exhibited by helicene oligomers. It includes the inversion of relative thermodynamic stability induced by temperature changes and molecular thermal hysteresis in a closed system. The thermal phenomenon associated with the oligomers involves population/concentration changes between metastable states under nonequilibrium thermodynamic control. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Using Nanoparticles for Enhance Thermal Conductivity of Latent Heat Thermal Energy Storage

    Directory of Open Access Journals (Sweden)

    Baydaa Jaber Nabhan

    2015-06-01

    Full Text Available Phase change materials (PCMs such as paraffin wax can be used to store or release large amount of energy at certain temperature at which their solid-liquid phase changes occurs. Paraffin wax that used in latent heat thermal energy storage (LHTES has low thermal conductivity. In this study, the thermal conductivity of paraffin wax has been enhanced by adding different mass concentration (1wt.%, 3wt.%, 5wt.% of (TiO2 nano-particles with about (10nm diameter. It is found that the phase change temperature varies with adding (TiO2 nanoparticles in to the paraffin wax. The thermal conductivity of the composites is found to decrease with increasing temperature. The increase in thermal conductivity has been found to increase by about (10% at nanoparticles loading (5wt.% and 15oC.

  1. Life cycle analysis of underground thermal energy storage

    NARCIS (Netherlands)

    Tomasetta, Camilla; van Ree, Derk; Griffioen, Jasper

    2015-01-01

    Underground Thermal Energy Storage (UTES) systems are used to buffer the seasonal difference between heat and cold supply and demand and, therefore, represent an interesting option to conserve energy. Even though UTES are considered environmental friendly solutions they are not completely free of

  2. Combination of aquifer thermal energy storage and enhanced bioremediation

    NARCIS (Netherlands)

    Ni, Zhuobiao; Gaans, van Pauline; Rijnaarts, Huub; Grotenhuis, Tim

    2018-01-01

    Interest in the combination concept of aquifer thermal energy storage (ATES) and enhanced bioremediation has recently risen due to the demand for both renewable energy technology and sustainable groundwater management in urban areas. However, the impact of enhanced bioremediation on ATES is not

  3. Study of thermally coupled distillation systems for energy-efficient ...

    Indian Academy of Sciences (India)

    Distillation is one of the most widely used separation unit operations in process industries, although it is quite energy intensive. In many cases, the enormous energy requirements for distillation make it economically infeasible to carry out the separation. Thermally coupled distillation system (TCDS) is an advanced distillation ...

  4. Assessing the sustainable application of Aquifer Thermal Energy Storage

    NARCIS (Netherlands)

    Jaxa-Rozen, M.; Bloemendal, J.M.; Rostampour Samarin, V.; Kwakkel, J.H.

    2016-01-01

    Aquifer Thermal Energy Storage (ATES) can yield significant reductions in the energy use and greenhouse gas (GHG) emissions of larger buildings, and the use of these systems has been rapidly growing in Europe – especially in the Netherlands, where over 3000 systems are currently active in urban

  5. Survey of EPA facilities for solar thermal energy applications

    Science.gov (United States)

    Nelson, E. V.; Overly, P. T.; Bell, D. M.

    1980-01-01

    A study was done to assess the feasibility of applying solar thermal energy systems to EPA facilities. A survey was conducted to determine those EPA facilities where solar energy could best be used. These systems were optimized for each specific application and the system/facility combinations were ranked on the basis of greatest cost effectiveness.

  6. A method for storing energy in the thermal form

    International Nuclear Information System (INIS)

    Bonnin, Jacques.

    1973-01-01

    The thermal energy generated during slack hours by a main energy-generating unit A is partially used for heating a storage fluid flowing in a storage and recovery unit B, and that storage fluid which is preferably water, is stored under pressure in a tank. This can be applied to light water nuclear power stations [fr

  7. Iron Oxide Films Prepared by Rapid Thermal Processing for Solar Energy Conversion.

    Science.gov (United States)

    Wickman, B; Bastos Fanta, A; Burrows, A; Hellman, A; Wagner, J B; Iandolo, B

    2017-01-16

    Hematite is a promising and extensively investigated material for various photoelectrochemical (PEC) processes for energy conversion and storage, in particular for oxidation reactions. Thermal treatments during synthesis of hematite are found to affect the performance of hematite electrodes considerably. Herein, we present hematite thin films fabricated via one-step oxidation of Fe by rapid thermal processing (RTP). In particular, we investigate the effect of oxidation temperature on the PEC properties of hematite. Films prepared at 750 °C show the highest activity towards water oxidation. These films show the largest average grain size and the highest charge carrier density, as determined from electron microscopy and impedance spectroscopy analysis. We believe that the fast processing enabled by RTP makes this technique a preferred method for investigation of novel materials and architectures, potentially also on nanostructured electrodes, where retaining high surface area is crucial to maximize performance.

  8. Study of thermal energy storage using fluidized bed heat exchangers

    Science.gov (United States)

    Weast, T. E.; Shannon, L. J.; Ananth, K. P.

    1980-01-01

    The technical and economic feasibility of fluid bed heat exchangers (FBHX) for thermal energy storage (TES) in waste heat recovery applications is assessed by analysis of two selected conceptual systems, the rotary cement kiln and the electric arc furnace. It is shown that the inclusion of TES in the energy recovery system requires that the difference in off-peak and on-peak energy rates be large enough so that the value of the recovered energy exceeds the value of the stored energy by a wide enough margin to offset parasitic power and thermal losses. Escalation of on-peak energy rates due to fuel shortages could make the FBHX/TES applications economically attractive in the future.

  9. Determination of P3HT Trap Site Energies by Thermally Stimulated Current

    Science.gov (United States)

    Souza, J. F. P.; Serbena, J. P. M.; Kowalski, E. L.; Akcelrud, L. C.

    2018-02-01

    The thermal, electrical and morphological characterization of poly(3-hexylthiophene-2,5diyl) (P3HT) is presented and discussed. Thermal analyses revealed high glass transition, melting and degradation temperatures, indicating high stability of the polymer to annealings in the range 25-200°C. Electrical measurements were performed in spin-coated devices constructed using indium tin oxide (ITO) and poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) in the sandwich structure ITO/PEDOT:PSS/P3HT/Al. The devices were thermally treated at 25°C, 100°C, 150°C, and 200°C prior to the measurements. Characteristic curves of current density versus voltage showed that the injection of charge carriers is governed by tunneling at high electric fields. Hole mobility was estimated by impedance spectroscopy, showing a maximum value of 8.6 × 10-5 cm2/Vs for annealed films at 150°C. A thermally stimulated current technique was used to analyze the trap density in the P3HT and its respective energies for all devices, presenting the lowest trap density for annealed films at 150°C. Morphological features observed by atomic force microscopy showed that the 150°C thermally treated film presents the best interface condition of the four investigated annealing temperatures.

  10. Renewable Energy Essentials: Concentrating Solar Thermal Power

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    Concentrated solar thermal power (CSP) is a re-emerging market. The Luz Company built 354 MWe of commercial plants in California, still in operations today, during 1984-1991. Activity re-started with the construction of an 11-MW plant in Spain, and a 64-MW plant in Nevada, by 2006. There are currently hundreds of MW under construction, and thousands of MW under development worldwide. Spain and the United States together represent 90% of the market. Algeria, Egypt and Morocco are building integrated solar combined cycle plants, while Australia, China, India, Iran, Israel, Italy, Jordan, Mexico, South Africa and the United Arab Emirates are finalising or considering projects. While trough technology remains the dominant technology, several important innovations took place over 2007-2009: the first commercial solar towers, the first commercial plants with multi-hour capacities, the first Linear Fresnel Reflector plants went into line.

  11. DNA - A Thermal Energy System Simulator

    DEFF Research Database (Denmark)

    2008-01-01

    DNA is a general energy system simulator for both steady-state and dynamic simulation. The program includes a * component model library * thermodynamic state models for fluids and solid fuels and * standard numerical solvers for differential and algebraic equation systems and is free and portable...

  12. Preparation, characterization, and thermal properties of microencapsulated phase change material for thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Alkan, Cemil; Sari, Ahmet; Karaipekli, Ali [Department of Chemistry, Gaziosmanpasa University, 60240 Tokat (Turkey); Uzun, Orhan [Department of Physics, Gaziosmanpasa University, 60240 Tokat (Turkey)

    2009-01-15

    This study is focused on the preparation, characterization, and determination of thermal properties of microencapsulated docosane with polymethylmethacrylate (PMMA) as phase change material for thermal energy storage. Microencapsulation of docosane has been carried out by emulsion polymerization. The microencapsulated phase change material (MEPCM) was characterized using scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy. Thermal properties and thermal stability of MEPCM were measured by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). DSC analysis indicated that the docosane in the microcapsules melts at 41.0 C and crystallizes at 40.6 C. It has latent heats of 54.6 and -48.7 J/g for melting and crystallization, respectively. TGA showed that the MEPCM degraded in three distinguishable steps and had good chemical stability. Accelerated thermal cycling tests also indicated that the MEPCM had good thermal reliability. Based on all these results, it can be concluded that the microencapsulated docosane as MEPCMs have good potential for thermal energy storage purposes such as solar space heating applications. (author)

  13. Surface passivation and carrier selectivity of the thermal-atomic-layer-deposited TiO2 on crystalline silicon

    Science.gov (United States)

    Plakhotnyuk, Maksym M.; Schüler, Nadine; Shkodin, Evgeniy; Ammapet Vijayan, Ramachandran; Masilamani, Sangaravadivel; Varadharajaperumal, Muthubalan; Crovetto, Andrea; Hansen, Ole

    2017-08-01

    Here, we demonstrate the use of an ultrathin TiO2 film as a passivating carrier-selective contact for silicon photovoltaics. The effective lifetime, surface recombination velocity, and diode quality dependence on TiO2 deposition temperature with and without a thin tunneling oxide interlayer (SiO2 or Al2O3) on p-type crystalline silicon (c-Si) are reported. 5-, 10-, and 20-nm-thick TiO2 films were deposited by thermal atomic layer deposition (ALD) in the temperature range of 80-300 °C using titanium tetrachloride (TiCl4) and water. TiO2 thin-film passivation layers alone result in a lower effective carrier lifetime compared with that with an interlayer. However, SiO2 and Al2O3 interlayers enhance the TiO2 passivation of c-Si surfaces. Further annealing at 200 °C in N2 gas enhances the surface passivation quality of TiO2 tremendously. From these findings, design principles for TiO2-Si heterojunction with optimized photovoltage, interface quality, and electron extraction to maximize the photovoltage of TiO2-Si heterojunction photovoltaic cells are formulated. Diode behaviour was analysed with the help of experimental, analytical, and simulation methods. It is predicted that TiO2 with a high carrier concentration is a preferable candidate for high-performance solar cells. The possible reasons for performance degradation in those devices with and without interlayers are also discussed.

  14. Buffer thermal energy storage for a solar Brayton engine

    Science.gov (United States)

    Strumpf, H. J.; Barr, K. P.

    1981-01-01

    A study has been completed on the application of latent-heat buffer thermal energy storage to a point-focusing solar receiver equipped with an air Brayton engine. To aid in the study, a computer program was written for complete transient/stead-state Brayton cycle performance. The results indicated that thermal storage can afford a significant decrease in the number of engine shutdowns as compared to operating without thermal storage. However, the number of shutdowns does not continuously decrease as the storage material weight increases. In fact, there appears to be an optimum weight for minimizing the number of shutdowns.

  15. Thermal energy storage using phase change materials fundamentals and applications

    CERN Document Server

    Fleischer, Amy S

    2015-01-01

    This book presents a comprehensive introduction to the use of solid‐liquid phase change materials to store significant amounts of energy in the latent heat of fusion. The proper selection of materials for different applications is covered in detail, as is the use of high conductivity additives to enhance thermal diffusivity. Dr. Fleischer explores how applications of PCMS have expanded over the past 10 years to include the development of high efficiency building materials to reduce heating and cooling needs, smart material design for clothing, portable electronic systems thermal management, solar thermal power plant design and many others. Additional future research directions and challenges are also discussed.

  16. Thermal energy harvesting for application at MEMS scale

    CERN Document Server

    Percy, Steven; McGarry, Scott; Post, Alex; Moore, Tim; Cavanagh, Kate

    2014-01-01

    This book discusses the history of thermal heat generators and focuses on the potential for these processes using micro-electrical mechanical systems (MEMS) technology for this application. The main focus is on the capture of waste thermal energy for example from industrial processes, transport systems or the human body to generate useable electrical power.  A wide range of technologies is discussed, including external combustion heat cycles at MEMS ( Brayton, Stirling and Rankine), Thermoacoustic, Shape Memory Alloys (SMAs), Multiferroics, Thermionics, Pyroelectric, Seebeck, Alkali Metal Thermal, Hydride Heat Engine, Johnson Thermo Electrochemical Converters, and the Johnson Electric Heat Pipe.

  17. Optimal Scheduling of a Multi-Carrier Energy Hub Supplemented By Battery Energy Storage Systems

    DEFF Research Database (Denmark)

    Javadi, Mohammad Sadegh; Anvari-Moghaddam, Amjad; Guerrero, Josep M.

    2017-01-01

    systems (ESSs), and heating/cooling devices such as electrical heater, heat-pumps and absorption chillers. The optimal scheduling and management of the examined energy hub assets in line with electrical transactions with distribution network is modeled as a mixed-integer non-linear optimization problem...

  18. Rotational energy conversion and thermal evolution of neutron stars

    Science.gov (United States)

    Zhu, Cui; Zhou, Xia; Wang, Na

    2017-12-01

    Pulsars are rapidly spinning, strongly magnetized neutron stars. Their electromagnetic dipole radiation is usually assumed to be at the expense of the rotational energy. In this work, we consider a new channel through which rotational energy could be radiated away directly via neutrinos. With this new energy conversion channel, we can improve the chemical heating mechanism that originates in the deviation from β equilibrium due to spin-down compression. The improved chemical and thermal evolution equations with different magnetic field strengths are solved numerically. The results show that the new energy conversion channel could raise the surface temperature of neutron stars, especially for weak field stars at later stages of their evolution. Moreover, our results indicate that the new energy conversion channel induced by the non-equilibrium reaction processes should be taken into account in the study of thermal evolution. Supported by National Natural Science Foundation of China (11373006) and the West Light Foundation of Chinese Academy of Sciences (ZD201302)

  19. Thermal indoor environment and energy consumption in a plus-energy house: cooling season measurements

    DEFF Research Database (Denmark)

    Kazanci, Ongun Berk; Olesen, Bjarne W.

    2015-01-01

    the floor cooling system) and increasing the ventilation rate provided a better thermal indoor environment but with increased energy consumption. The thermal indoor environment and energy performance of the house can be improved with decreased glazing area, increased thermal mass, installation of solar......The present study is concerned with the thermal indoor environment and HVAC system energy consumption of a detached, one-story, single family, plus-energy house during a cooling season. The house was located in Denmark and it has been used as a full-scale experimental facility for one year....... The house was cooled by a floor cooling system and was ventilated with a mechanical ventilation system. Different operative temperature set-points and different ventilation rates were tested. Operative temperature at a representative location inside the occupied zone was used as an indicator of the thermal...

  20. Power-generating process of obtaining gas-energy carrier and reducer from coal

    International Nuclear Information System (INIS)

    Tleugabulov, S.; Duncheva, E.; Zubkevich, M.

    1999-01-01

    The manufacture of power-generating gas has the important economic value for Kazakhstan having large territory, raw and fuel resources especially power coal and clean coal wastes. The technology of reception of gas-energy carrier and reducer from power coal is developed. The basic product of technological process is heated reducing gas. Reducing potential of the gas is characterized by a volumetric share of components (CO+H 2 )-RC in relation to volume of whole mix of gases received with gasification of coal. The value of parameter RC is regulated by a degree of enrichment of air by oxygen r 0 , and the temperature - by the charge of a parity of endothermic reaction in the chamber of gas regeneration. The dependence of the gas structure and temperature on the degree of enrichment of air by oxygen is shown and the circuit of the gas generator is given. (author)

  1. Phase-change thermal energy storage: Final subcontract report

    Energy Technology Data Exchange (ETDEWEB)

    1989-11-01

    The research and development described in this document was conducted within the US Department of Energy's Solar Thermal Technology Program. The goal of this program is to advance the engineering and scientific understanding of solar thermal technology and to establish the technology base from which private industry can develop solar thermal power production options for introduction into the competitive energy market. Solar thermal technology concentrates the solar flux using tracking mirrors or lenses onto a receiver where the solar energy is absorbed as heat and converted into electricity or incorporated into products as process heat. The two primary solar thermal technologies, central receivers and distributed receivers, employ various point and line-focus optics to concentrate sunlight. Current central receiver systems use fields of heliostats (two-axes tracking mirrors) to focus the sun's radiant energy onto a single, tower-mounted receiver. Point focus concentrators up to 17 meters in diameter track the sun in two axes and use parabolic dish mirrors or Fresnel lenses to focus radiant energy onto a receiver. Troughs and bowls are line-focus tracking reflectors that concentrate sunlight onto receiver tubes along their focal lines. Concentrating collector modules can be used alone or in a multimodule system. The concentrated radiant energy absorbed by the solar thermal receiver is transported to the conversion process by a circulating working fluid. Receiver temperatures range from 100{degree}C in low-temperature troughs to over 1500{degree}C in dish and central receiver systems. 12 refs., 119 figs., 4 tabs.

  2. Descriptive analysis of aquifer thermal energy storage systems

    Energy Technology Data Exchange (ETDEWEB)

    Reilly, R.W.

    1980-06-01

    The technical and economic feasibility of large-scale aquifer thermal energy storage (ATES) was examined. A key to ATESs attractiveness is its simplicity of design and construction. The storage device consists of two ordinary water wells drilled into an aquifer, connected at the surface by piping and a heat exchanger. During the storage cycle water is pumped out of the aquifer, through the heat exchanger to absorb thermal energy, and then back down into the aquifer through the second well. The thermal storage remains in the aquifer storage bubble until required for use, when it is recovered by reversing the storage operation. For many applications the installation can probably be designed and constructed using existing site-specific information and modern well-drilling techniques. The potential for cost-effective implementation of ATES was investigated in the Twin Cities District Heating-Cogeneration Study in Minnesota. In the study, ATES demonstrated a net energy saving of 32% over the nonstorage scenario, with an annual energy cost saving of $31 million. Discounting these savings over the life of the project, the authors found that the break-even capital cost for ATES construction was $76/kW thermal, far above the estimated ATES development cost of $23 to 50/kW thermal. It appears tht ATES can be highly cost effective as well as achieve substantial fuel savings. ATES would be environmentally beneficial and could be used in many parts of the USA. The existing body of information on ATES indicates that it is a cost-effective, fuel-conserving technique for providing thermal energy for residential, commercial, and industrial users. The negative aspects are minor and highly site-specific, and do not seem to pose a threat to widespread commercialization. With a suitable institutional framework, ATES promises to supply a substantial portion of the nation's future energy needs. (LCL)

  3. Phonon Surface Scattering and Thermal Energy Distribution in Superlattices.

    Science.gov (United States)

    Kothari, Kartik; Maldovan, Martin

    2017-07-17

    Thermal transport at small length scales has attracted significant attention in recent years and various experimental and theoretical methods have been developed to establish the reduced thermal conductivity. The fundamental understanding of how phonons move and the physical mechanisms behind nanoscale thermal transport, however, remains poorly understood. Here we move beyond thermal conductivity calculations and provide a rigorous and comprehensive physical description of thermal phonon transport in superlattices by solving the Boltzmann transport equation and using the Beckman-Kirchhoff surface scattering theory with shadowing to precisely describe phonon-surface interactions. We show that thermal transport in superlattices can be divided in two different heat transport modes having different physical properties at small length scales: layer-restricted and extended heat modes. We study how interface conditions, periodicity, and composition can be used to manipulate the distribution of thermal energy flow among such layer-restricted and extended heat modes. From predicted frequency and mean free path spectra of superlattices, we also investigate the existence of wave effects. The results and insights in this paper advance the fundamental understanding of heat transport in superlattices and the prospects of rationally designing thermal systems with tailored phonon transport properties.

  4. Thermal Energy Optimization of Building Integrated Semi-Transparent Photovoltaic Thermal Systems

    Directory of Open Access Journals (Sweden)

    Ekoe A Akata Aloys Martial

    2015-07-01

    Full Text Available Building integrated photovoltaic (BIPV : The concept where the photovoltaic element assumes the function of power generation and the role of the covering component element has the potential to become one of the principal sources of renewable energy for domestic purpose. In this paper, a Building integrated semitransparent photovoltaic thermal system (BISPVT system having fins at the back sheet of the photovoltaic module has been simulated. It has been observed that this system produces higher thermal and electrical efficiencies. The increase of wind velocity by fan system and heat exchange surface accelerates the convective heat transfer between the finned surface and the fluid flowing in the duct. The system area of 36.45 m2 is capable of annually producing an amount of thermal energy of 76.66 kWh at an overall thermal efficiency of 56.07 %.

  5. Hydrogen as an energy carrier. Final report; Wasserstoff als Energietraeger. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Rebholz, H. [ed.

    1998-12-01

    This final report of the Special Field of Research 270 (SFB 270) documents the work and results of the four promotion phases from 1989 to 1998, presented in reports on 15 part-projects. From its inception, SFB 270, which bears the title ''Hydrogen as an Energy Carrier'', has been dedicated to two fields of work: in Project Area A to the production of hydrogen (7 part-projects) and in Project Area B to the transport and storage of hydrogen (8 part-projects). The scientific results of the part-projects have also been presented in detail in the progress reports and interim reports of 1991, 1994 and 1997. Some of them have also been presented at the colloquiums of SFB 270. Twelve part-projects have been abstracted individually for the ENERGY database. [German] Der vorliegende Abschlussbericht des Sonderforschungsbereichs 270 dokumentiert die Arbeiten und Ergebnisse der vier Foerderungsphasen von 1989 bis 1998. Sie sind in den Berichten von 15 Teilprojekten wiedergegeben. Der Sonderforschungsbereich 270 'Wasserstoff als Energietraeger' hat sich von Anfang an zwei Aufgabengebieten gewidmet: Im Projektbereich A der Herstellung von Wasserstoff (7 Teilprojekte) und im Projektbereich B dem Transport und der Speicherung von Wasserstoff (8 Teilprojekte). Wissenschaftliche Ergebnisse der Teilprojekte sind ausfuehrlich auch in den Arbeits- und Ergebnisberichten 1991, 1994 und 1997 wiedergegeben. Sie wurden auch, in Teilen, in entsprechenden Kolloquien des SFB 270 praesentiert. Fuer die Datenbank ENERGY wurden 12 Teilprojekte separat aufgenommen. (orig.)

  6. Metal hydride-based thermal energy storage systems

    Science.gov (United States)

    Vajo, John J.; Fang, Zhigang

    2017-10-03

    The invention provides a thermal energy storage system comprising a metal-containing first material with a thermal energy storage density of about 1300 kJ/kg to about 2200 kJ/kg based on hydrogenation; a metal-containing second material with a thermal energy storage density of about 200 kJ/kg to about 1000 kJ/kg based on hydrogenation; and a hydrogen conduit for reversibly transporting hydrogen between the first material and the second material. At a temperature of 20.degree. C. and in 1 hour, at least 90% of the metal is converted to the hydride. At a temperature of 0.degree. C. and in 1 hour, at least 90% of the metal hydride is converted to the metal and hydrogen. The disclosed metal hydride materials have a combination of thermodynamic energy storage densities and kinetic power capabilities that previously have not been demonstrated. This performance enables practical use of thermal energy storage systems for electric vehicle heating and cooling.

  7. Application of nanomaterials in solar thermal energy storage

    Science.gov (United States)

    Shamshirgaran, Seyed Reza; Khalaji Assadi, Morteza; Viswanatha Sharma, Korada

    2017-12-01

    Solar thermal conversion technology harvests the sun's energy, rather than fossil fuels, to generate low-cost, low/zero-emission energy in the form of heating, cooling or electrical form for residential, commercial, and industrial sectors. The advent of nanofluids and nanocomposites or phase change materials, is a new field of study which is adapted to enhance the efficiency of solar collectors. The concepts of thermal energy storage technologies are investigated and the role of nanomaterials in energy conversion is discussed. This review revealed that although the exploitation of nanomaterials will boost the performance of solar collectors almost in all cases, this would be accompanied by certain challenges such as production cost, instability, agglomeration and erosion. Earlier studies have dealt with the enhancement of thermal conductivity and heat capacity; however, less attention has been given to the facing challenges. Moreover, no exact criteria can be found for the selection of appropriate nanomaterials and their properties for a specific application. In most research studies, the nanoparticles' material and properties have not been selected based on estimated values so that all the aspects of desired application could be considered simultaneously. The wide spread use of nanomaterials can lead to cost effective solutions as well. Therefore, it seems there should be a sense of techno-economic optimization in exploiting nanomaterials for solar thermal energy storage applications. The optimization should cover the key parameters, particularly nanoparticle type, size, loading and shape which depends on the sort of application and also dispersion technology.

  8. Advanced phase change composite by thermally annealed defect-free graphene for thermal energy storage.

    Science.gov (United States)

    Xin, Guoqing; Sun, Hongtao; Scott, Spencer Michael; Yao, Tiankai; Lu, Fengyuan; Shao, Dali; Hu, Tao; Wang, Gongkai; Ran, Guang; Lian, Jie

    2014-09-10

    Organic phase change materials (PCMs) have been utilized as latent heat energy storage and release media for effective thermal management. A major challenge exists for organic PCMs in which their low thermal conductivity leads to a slow transient temperature response and reduced heat transfer efficiency. In this work, 2D thermally annealed defect-free graphene sheets (GSs) can be obtained upon high temperature annealing in removing defects and oxygen functional groups. As a result of greatly reduced phonon scattering centers for thermal transport, the incorporation of ultralight weight and defect free graphene applied as nanoscale additives into a phase change composite (PCC) drastically improve thermal conductivity and meanwhile minimize the reduction of heat of fusion. A high thermal conductivity of the defect-free graphene-PCC can be achieved up to 3.55 W/(m K) at a 10 wt % graphene loading. This represents an enhancement of over 600% as compared to pristine graphene-PCC without annealing at a comparable loading, and a 16-fold enhancement than the pure PCM (1-octadecanol). The defect-free graphene-PCC displays rapid temperature response and superior heat transfer capability as compared to the pristine graphene-PCC or pure PCM, enabling transformational thermal energy storage and management.

  9. Electrical Energy Harvesting from Thermal Energy with Converged Infrared Light

    Science.gov (United States)

    Goh, S. Y.; Kok, S. L.

    2017-06-01

    Photovoltaics (PV) cell is a common energy harvester that had been used to harvest solar energy and convert it into electrical energy. However, the vast energy from the spectrum of sunlight is not fully harvested. Therefore, thermoelectric (TE) module that harvest electrical energy from heat is being proposed in this paper. Generally, the part of the sunlight spectrum that induce heat is in the spectrum band of infrared (IR). For the experimental set-up in this paper, infrared (IR) light bulb was being used to simulate the IR spectrum band of the sunlight. In order to maximize the heat energy collection, a convex lens was being used to converge the IR light and therefore focused the heat on an aluminium sheet and heat sink which was placed on top of the hot side of the TE module. The distance between convex lens and IR light bulb is varying in between 10cm and 55cm and the reading was taken at an interval of 5cm. Firstly, the temperature of the IR light and converged IR light were recorded and plotted in graph. The graph showed that the temperature of the converged IR light bulb is higher than the IR light bulb. Lastly, the voltage and power output of the TE module with different heat source was compared. The output voltage and power of the TE module increased inverse proportional to the distance between IR light bulb and TE module.

  10. Thermal comfort and building energy consumption implications – A review

    International Nuclear Information System (INIS)

    Yang, Liu; Yan, Haiyan; Lam, Joseph C.

    2014-01-01

    Highlights: • We review studies of thermal comfort and discuss building energy use implications. • Adaptive comfort models tend to have a wider comfort temperature range. • Higher indoor temperatures would lead to fewer cooling systems and less energy use. • Socio-economic study and post-occupancy evaluation of built environment is desirable. • Important to consider future climate scenarios in heating, cooling and power schemes. - Abstract: Buildings account for about 40% of the global energy consumption and contribute over 30% of the CO 2 emissions. A large proportion of this energy is used for thermal comfort in buildings. This paper reviews thermal comfort research work and discusses the implications for building energy efficiency. Predicted mean vote works well in air-conditioned spaces but not naturally ventilated buildings, whereas adaptive models tend to have a broader comfort temperature ranges. Higher indoor temperatures in summertime conditions would lead to less prevalence of cooling systems as well as less cooling requirements. Raising summer set point temperature has good energy saving potential, in that it can be applied to both new and existing buildings. Further research and development work conducive to a better understanding of thermal comfort and energy conservation in buildings have been identified and discussed. These include (i) social-economic and cultural studies in general and post-occupancy evaluation of the built environment and the corresponding energy use in particular, and (ii) consideration of future climate scenarios in the analysis of co- and tri-generation schemes for HVAC applications, fuel mix and the associated energy planning/distribution systems in response to the expected changes in heating and cooling requirements due to climate change

  11. Carriers of Recessive WNK1/HSN2 Mutations for Hereditary Sensory and Autonomic Neuropathy Type 2 (HSAN2) Are More Sensitive to Thermal Stimuli

    Science.gov (United States)

    Loggia, Marco L.; Bushnell, M. Catherine; Tétreault, Martine; Thiffault, Isabelle; Bhérer, Claude; Mohammed, Nazma K.; Kuchinad, Anil A.; Laferrière, Audrey; Dicaire, Marie-Josée; Loisel, Lina; Mogil, Jeffrey S.; Brais, Bernard

    2009-01-01

    Hereditary sensory and autonomic neuropathy type 2 (HSAN2) is a rare recessive genetic disorder characterized by severe sensory loss affecting the tactile, thermal and nociceptive modalities. Although heterozygous carriers of nonsense mutations in the HSN2 gene, called with-no-lysine(K)-1 (WNK1), do not develop the disease, historical and experimental evidence suggests that these individuals might perceive somatosensory stimuli differently from others. Using the method-of-limits, we assessed the thresholds for warmth detection, cool detection, heat pain and cold pain in 25 mutation carriers and 35 controls. In group analyses, carriers displayed significantly lower warmth (p cool (p cool stimuli (p = 0.11). Furthermore, the differences between the warmth detection thresholds of the carriers and those of gender- and sex-matched wild types significantly increased with age (r = 0.76, p = 0.02), and in carriers cool detection thresholds did not increase with age (r = 0.27, p = 0.24) as expected and observed in controls (r = 0.34, p = 0.05). This study demonstrates that the carriers of a recessive mutation for HSAN2 display greater sensitivity to innocuous thermal stimuli, as well as for cold pain, suggesting a possible environmental adaptive advantage of the heterozygous state. PMID:19228968

  12. Coadunation of technologies: Cogeneration and thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Somasundaram, S.; Drost, M. K.; Brown, D. R.; Antoniak, Z. A.

    1993-09-01

    Cogeneration is playing an increasingly important role in providing an independent and on-site high-efficiency source of power generation and thermal energy for space heating and cooling, as well as industrial process heat applications. However, the range of applications of cogeneration technology could be further extended if the generation of electricity could be decoupled from the generation of thermal energy for process use or space conditioning. The technology of thermal energy storage (TES) provides just such a decoupling that allows for the production of dispatchable power while fully utilizing the thermal energy available from the prime mover of the cogeneration system. The thermal energy from the prime mover exhaust can be stored either as sensible heat or as latent heat and used during peak demand periods to produce electric power or process steam/hot water. However, the additional materials and equipment necessary for a TES system will add to the capital as well as maintenance costs. Therefore, the economic benefits of adding TES to a conventional cogeneration system would have to outweigh the increased costs of the combined system. This paper addresses some of the TES systems that are readily applicable to be combined with cogeneration systems, as well as provide an update on the current status of these TES systems. TES allows a cogeneration facility to (1) provide dispatchable electric power while providing a constant thermal load, and (2) increase peak capacity by providing economical cooling of the combustion turbine inlet air. The particular systems addressed are high-temperature diurnal TES, and TES for cooling the combustion turbine inlet air.

  13. High temperature latent heat thermal energy storage to augment solar thermal propulsion for microsatellites

    Science.gov (United States)

    Gilpin, Matthew R.

    Solar thermal propulsion (STP) offers an unique combination of thrust and efficiency, providing greater total DeltaV capability than chemical propulsion systems without the order of magnitude increase in total mission duration associated with electric propulsion. Despite an over 50 year development history, no STP spacecraft has flown to-date as both perceived and actual complexity have overshadowed the potential performance benefit in relation to conventional technologies. The trend in solar thermal research over the past two decades has been towards simplification and miniaturization to overcome this complexity barrier in an effort finally mount an in-flight test. A review of micro-propulsion technologies recently conducted by the Air Force Research Laboratory (AFRL) has identified solar thermal propulsion as a promising configuration for microsatellite missions requiring a substantial Delta V and recommended further study. A STP system provides performance which cannot be matched by conventional propulsion technologies in the context of the proposed microsatellite ''inspector" requiring rapid delivery of greater than 1500 m/s DeltaV. With this mission profile as the target, the development of an effective STP architecture goes beyond incremental improvements and enables a new class of microsatellite missions. Here, it is proposed that a bi-modal solar thermal propulsion system on a microsatellite platform can provide a greater than 50% increase in Delta V vs. chemical systems while maintaining delivery times measured in days. The realization of a microsatellite scale bi-modal STP system requires the integration of multiple new technologies, and with the exception of high performance thermal energy storage, the long history of STP development has provided "ready" solutions. For the target bi-modal STP microsatellite, sensible heat thermal energy storage is insufficient and the development of high temperature latent heat thermal energy storage is an enabling

  14. Heat Recovery from Exhaust Air as a Thermal Storage Energy Source for Geothermal Energy Piles

    OpenAIRE

    Fadejev, Jevgeni; Simson, Raimo; Kurnitski, Jarek; Kesti, Jyrki

    2016-01-01

    In pursuit of EU directive 2010/31/EU energy performance targets towards design of nearly zero-energy buildings consideration of renewable energy sources in the design is expected. Application of ground-source heat pump (GSHP) and energy piles in cold climate conditions for utilization of renewable geothermal energy may results in GSHP plant high seasonal coefficient of performance (SCOP) as long as source of thermal storage is considered in plant design. This numerical study investigates exh...

  15. Semi-transparent solar energy thermal storage device

    Science.gov (United States)

    McClelland, John F.

    1985-06-18

    A visually transmitting solar energy absorbing thermal storage module includes a thermal storage liquid containment chamber defined by an interior solar absorber panel, an exterior transparent panel having a heat mirror surface substantially covering the exterior surface thereof and associated top, bottom and side walls, Evaporation of the thermal storage liquid is controlled by a low vapor pressure liquid layer that floats on and seals the top surface of the liquid. Porous filter plugs are placed in filler holes of the module. An algicide and a chelating compound are added to the liquid to control biological and chemical activity while retaining visual clarity. A plurality of modules may be supported in stacked relation by a support frame to form a thermal storage wall structure.

  16. Thermal energy accumulation in stratified hot water stores

    OpenAIRE

    Cohen, R. R.

    1986-01-01

    Hot water thermal energy stores have the potential to improve and extend the performance of many kinds of energy system. Waperature stratification in the store is likely to affect the system's efficiency. A basic but accurate computer model of the hot water store under various inlet flow conditions is a requisite means of assesiing promising applications of hot water storage by system computer simulation techniques. A microprocessor-controlled test facility has been const...

  17. Imaging Spatial Variations in the Dissipation and Transport of Thermal Energy within Individual Silicon Nanowires Using Ultrafast Microscopy.

    Science.gov (United States)

    Cating, Emma E M; Pinion, Christopher W; Van Goethem, Erika M; Gabriel, Michelle M; Cahoon, James F; Papanikolas, John M

    2016-01-13

    Thermal management is an important consideration for most nanoelectronic devices, and an understanding of the thermal conductivity of individual device components is critical for the design of thermally efficient systems. However, it can be difficult to directly probe local changes in thermal conductivity within a nanoscale system. Here, we utilize the time-resolved and diffraction-limited imaging capabilities of ultrafast pump-probe microscopy to determine, in a contact-free configuration, the local thermal conductivity in individual Si nanowires (NWs). By suspending single NWs across microfabricated trenches in a quartz substrate, the properties of the same NW both on and off the substrate are directly compared. We find the substrate has no effect on the recombination lifetime or diffusion length of photogenerated charge carriers; however, it significantly impacts the thermal relaxation properties of the NW. In substrate-supported regions, thermal energy deposited into the lattice by the ultrafast laser pulse dissipates within ∼10 ns through thermal diffusion and coupling to the substrate. In suspended regions, the thermal energy persists for over 100 ns, and we directly image the time-resolved spatial motion of the thermal signal. Quantitative analysis of the transient images permits direct determination of the NW's local thermal conductivity, which we find to be a factor of ∼4 smaller than in bulk Si. Our results point to the strong potential of pump-probe microscopy to be used as an all-optical method to quantify the effects of localized environment and morphology on the thermal transport characteristics of individual nanostructured components.

  18. Regolith thermal energy storage for lunar nighttime power

    Science.gov (United States)

    Tillotson, Brian

    1992-01-01

    A scheme for providing nighttime electric power to a lunar base is described. This scheme stores thermal energy in a pile of regolith. Any such scheme must somehow improve on the poor thermal conductivity of lunar regolith in vacuum. Two previous schemes accomplish this by casting or melting the regolith. The scheme described here wraps the regolith in a gas-tight bag and introduces a light gas to enhance thermal conductivity. This allows the system to be assembled with less energy and equipment than schemes which require melting of regolith. A point design based on the new scheme is presented. Its mass from Earth compares favorably with the mass of a regenerative fuel cell of equal capacity.

  19. Solar Thermal Energy Storage in a Photochromic Macrocycle.

    Science.gov (United States)

    Vlasceanu, Alexandru; Broman, Søren L; Hansen, Anne S; Skov, Anders B; Cacciarini, Martina; Kadziola, Anders; Kjaergaard, Henrik G; Mikkelsen, Kurt V; Nielsen, Mogens Brøndsted

    2016-07-25

    The conversion and efficient storage of solar energy is recognized to hold significant potential with regard to future energy solutions. Molecular solar thermal batteries based on photochromic systems exemplify one possible technology able to harness and apply this potential. Herein is described the synthesis of a macrocycle based on a dimer of the dihydroazulene/vinylheptafulvene (DHA/VHF) photo/thermal couple. By taking advantage of conformational strain, this DHA-DHA macrocycle presents an improved ability to absorb and store incident light energy in chemical bonds (VHF-VHF). A stepwise energy release over two sequential ring-closing reactions (VHF→DHA) combines the advantages of an initially fast discharge, hypothetically addressing immediate energy consumption needs, followed by a slow process for consistent, long-term use. This exemplifies another step forward in the molecular engineering and design of functional organic materials towards solar thermal energy storage and release. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Local thermal energy as a structural indicator in glasses.

    Science.gov (United States)

    Zylberg, Jacques; Lerner, Edan; Bar-Sinai, Yohai; Bouchbinder, Eran

    2017-07-11

    Identifying heterogeneous structures in glasses-such as localized soft spots-and understanding structure-dynamics relations in these systems remain major scientific challenges. Here, we derive an exact expression for the local thermal energy of interacting particles (the mean local potential energy change caused by thermal fluctuations) in glassy systems by a systematic low-temperature expansion. We show that the local thermal energy can attain anomalously large values, inversely related to the degree of softness of localized structures in a glass, determined by a coupling between internal stresses-an intrinsic signature of glassy frustration-anharmonicity and low-frequency vibrational modes. These anomalously large values follow a fat-tailed distribution, with a universal exponent related to the recently observed universal [Formula: see text] density of states of quasilocalized low-frequency vibrational modes. When the spatial thermal energy field-a "softness field"-is considered, this power law tail manifests itself by highly localized spots, which are significantly softer than their surroundings. These soft spots are shown to be susceptible to plastic rearrangements under external driving forces, having predictive powers that surpass those of the normal modes-based approach. These results offer a general, system/model-independent, physical/observable-based approach to identify structural properties of quiescent glasses and relate them to glassy dynamics.

  1. Long term energy performance analysis of Egbin thermal power ...

    African Journals Online (AJOL)

    This study is aimed at providing an energy performance analysis of Egbin thermal power plant. The plant operates on Regenerative Rankine cycle with steam as its working fluid .The model equations were formulated based on some performance parameters used in power plant analysis. The considered criteria were plant ...

  2. Local thermal energy as a structural indicator in glasses

    Science.gov (United States)

    Zylberg, Jacques; Lerner, Edan; Bar-Sinai, Yohai; Bouchbinder, Eran

    2017-07-01

    Identifying heterogeneous structures in glasses—such as localized soft spots—and understanding structure-dynamics relations in these systems remain major scientific challenges. Here, we derive an exact expression for the local thermal energy of interacting particles (the mean local potential energy change caused by thermal fluctuations) in glassy systems by a systematic low-temperature expansion. We show that the local thermal energy can attain anomalously large values, inversely related to the degree of softness of localized structures in a glass, determined by a coupling between internal stresses—an intrinsic signature of glassy frustration—anharmonicity and low-frequency vibrational modes. These anomalously large values follow a fat-tailed distribution, with a universal exponent related to the recently observed universal ω4ω4 density of states of quasilocalized low-frequency vibrational modes. When the spatial thermal energy field—a “softness field”—is considered, this power law tail manifests itself by highly localized spots, which are significantly softer than their surroundings. These soft spots are shown to be susceptible to plastic rearrangements under external driving forces, having predictive powers that surpass those of the normal modes-based approach. These results offer a general, system/model-independent, physical/observable-based approach to identify structural properties of quiescent glasses and relate them to glassy dynamics.

  3. Thermal effects on parallel resonance energy of whistler mode wave

    Indian Academy of Sciences (India)

    February 2006 physics pp. 467–472. Thermal effects on parallel resonance energy of whistler mode wave. DEVENDRAA SIINGH1, SHUBHA SINGH2 and R P SINGH2. 1Indian Institute of Tropical Meteorology, Dr. Homi Bhabha Road, Pune 411 008, India. 2Department of Physics, Banaras Hindu University, Varanasi 221 ...

  4. Thermal energy storage subsystems. A collection of quarterly reports

    Science.gov (United States)

    1978-01-01

    The design, development, and progress toward the delivery of three subsystems is discussed. The subsystem used a salt hydrate mixture for thermal energy storage. The program schedules, technical data, and other program activities from October 1, 1976, through December 31, 1977 are presented.

  5. Solar Program Assessment: Environmental Factors - Ocean Thermal Energy Conversion.

    Science.gov (United States)

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

    This report presents the environmental problems which may arise with the further development of Ocean Thermal Energy Conversion, one of the eight Federally-funded solar technologies. To provide a background for this environmental analysis, the history and basic concepts of the technology are reviewed, as are its economic and resource requirements.…

  6. Fuels and chemicals from biomass using solar thermal energy

    Science.gov (United States)

    Giori, G.; Leitheiser, R.; Wayman, M.

    1981-01-01

    The significant nearer term opportunities for the application of solar thermal energy to the manufacture of fuels and chemicals from biomass are summarized, with some comments on resource availability, market potential and economics. Consideration is given to the production of furfural from agricultural residues, and the role of furfural and its derivatives as a replacement for petrochemicals in the plastics industry.

  7. Conversion of concentrated solar thermal energy into chemical energy.

    Science.gov (United States)

    Tamaura, Yutaka

    2012-01-01

    When a concentrated solar beam is irradiated to the ceramics such as Ni-ferrite, the high-energy flux in the range of 1500-2500 kW/m(2) is absorbed by an excess Frenkel defect formation. This non-equilibrium state defect is generated not by heating at a low heating-rate (30 K/min), but by irradiating high flux energy of concentrated solar beam rapidly at a high heating rate (200 K/min). The defect can be spontaneously converted to chemical energy of a cation-excess spinel structure (reduced-oxide form) at the temperature around 1773 K. Thus, the O(2) releasing reaction (α-O(2) releasing reaction) proceeds in two-steps; (1) high flux energy of concentrated solar beam absorption by formation of the non-equilibrium Frenkel defect and (2) the O(2) gas formation from the O(2-) in the Frenkel defect even in air atmosphere. The 2nd step proceeds without the solar radiation. We may say that the 1st step is light reaction, and 2nd step, dark reaction, just like in photosynthesis process.

  8. Enhancing low-grade thermal energy recovery in a thermally regenerative ammonia battery using elevated temperatures.

    Science.gov (United States)

    Zhang, Fang; LaBarge, Nicole; Yang, Wulin; Liu, Jia; Logan, Bruce E

    2015-03-01

    A thermally regenerative ammonia battery (TRAB) is a new approach for converting low-grade thermal energy into electricity by using an ammonia electrolyte and copper electrodes. TRAB operation at 72 °C produced a power density of 236 ± 8 Wm(-2), with a linear decrease in power to 95 ± 5 Wm(-2) at 23 °C. The improved power at higher temperatures was due to reduced electrode overpotentials and more favorable thermodynamics for the anode reaction (copper oxidation). The energy density varied with temperature and discharge rates, with a maximum of 650 Wh m(-3) at a discharge energy efficiency of 54% and a temperature of 37 °C. The energy efficiency calculated with chemical process simulation software indicated a Carnot-based efficiency of up to 13% and an overall thermal energy recovery of 0.5%. It should be possible to substantially improve these energy recoveries through optimization of electrolyte concentrations and by using improved ion-selective membranes and energy recovery systems such as heat exchangers. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Enhancing Low-Grade Thermal Energy Recovery in a Thermally Regenerative Ammonia Battery Using Elevated Temperatures

    KAUST Repository

    Zhang, Fang

    2015-02-13

    © 2015 WILEY-VCH Verlag GmbH & Co. KGaA. A thermally regenerative ammonia battery (TRAB) is a new approach for converting low-grade thermal energy into electricity by using an ammonia electrolyte and copper electrodes. TRAB operation at 72°C produced a power density of 236±8 Wm-2, with a linear decrease in power to 95±5 Wm-2 at 23°C. The improved power at higher temperatures was due to reduced electrode overpotentials and more favorable thermodynamics for the anode reaction (copper oxidation). The energy density varied with temperature and discharge rates, with a maximum of 650 Whm-3 at a discharge energy efficiency of 54% and a temperature of 37°C. The energy efficiency calculated with chemical process simulation software indicated a Carnot-based efficiency of up to 13% and an overall thermal energy recovery of 0.5%. It should be possible to substantially improve these energy recoveries through optimization of electrolyte concentrations and by using improved ion-selective membranes and energy recovery systems such as heat exchangers.

  10. Thermal energy storage - overview and specific insight into nitrate salts for sensible and latent heat storage.

    Science.gov (United States)

    Pfleger, Nicole; Bauer, Thomas; Martin, Claudia; Eck, Markus; Wörner, Antje

    2015-01-01

    Thermal energy storage (TES) is capable to reduce the demand of conventional energy sources for two reasons: First, they prevent the mismatch between the energy supply and the power demand when generating electricity from renewable energy sources. Second, utilization of waste heat in industrial processes by thermal energy storage reduces the final energy consumption. This review focuses mainly on material aspects of alkali nitrate salts. They include thermal properties, thermal decomposition processes as well as a new method to develop optimized salt systems.

  11. Thermal energy storage based on cementitious materials: A review

    Directory of Open Access Journals (Sweden)

    Khadim Ndiaye

    2018-01-01

    Full Text Available Renewable energy storage is now essential to enhance the energy performance of buildings and to reduce their environmental impact. Many heat storage materials can be used in the building sector in order to avoid the phase shift between solar radiation and thermal energy demand. However, the use of storage material in the building sector is hampered by problems of investment cost, space requirements, mechanical performance, material stability, and high storage temperature. Cementitious material is increasingly being used as a heat storage material thanks to its low price, mechanical performance and low storage temperature (generally lower than 100 °C. In addition, cementitious materials for heat storage have the prominent advantage of being easy to incorporate into the building landscape as self-supporting structures or even supporting structures (walls, floor, etc.. Concrete solutions for thermal energy storage are usually based on sensible heat transfer and thermal inertia. Phase Change Materials (PCM incorporated in concrete wall have been widely investigated in the aim of improving building energy performance. Cementitious material with high ettringite content stores heat by a combination of physical (adsorption and chemical (chemical reaction processes usable in both the short (daily, weekly and long (seasonal term. Ettringite materials have the advantage of high energy storage density at low temperature (around 60 °C. The encouraging experimental results in the literature on heat storage using cementitious materials suggest that they could be attractive in a number of applications. This paper summarizes the investigation and analysis of the available thermal energy storage systems using cementitious materials for use in various applications.

  12. Performance maps for the control of thermal energy storage

    DEFF Research Database (Denmark)

    Finck, Christian; Li, Rongling; Zeiler, Wim

    2017-01-01

    Predictive control in building energy systems requires the integration of the building, building system, and component dynamics. The prediction accuracy of these dynamics is crucial for practical applications. This paper introduces performance maps for the control of water tanks, phase change mat...... material tanks, and thermochemical material tanks. The results show that these performance maps can fully account for the dynamics of thermal energy storage tanks.......Predictive control in building energy systems requires the integration of the building, building system, and component dynamics. The prediction accuracy of these dynamics is crucial for practical applications. This paper introduces performance maps for the control of water tanks, phase change...

  13. 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

  14. Measuring energy expenditure in sports by thermal video analysis

    DEFF Research Database (Denmark)

    Gade, Rikke; Larsen, Ryan Godsk; Moeslund, Thomas B.

    2017-01-01

    Estimation of human energy expenditure in sports and exercise contributes to performance analyses and tracking of physical activity levels. The focus of this work is to develop a video-based method for estimation of energy expenditure in athletes. We propose a method using thermal video analysis...... of oxygen uptake. These initial experiments indicate a correlation between estimated step frequency and oxygen uptake. Based on the preliminary results we conclude that the proposed method has potential as a future non-invasive approach to estimate energy expenditure during sports....

  15. [Thermal energy utilization analysis and energy conservation measures of fluidized bed dryer].

    Science.gov (United States)

    Xing, Liming; Zhao, Zhengsheng

    2012-07-01

    To propose measures for enhancing thermal energy utilization by analyzing drying process and operation principle of fluidized bed dryers,in order to guide optimization and upgrade of fluidized bed drying equipment. Through a systematic analysis on drying process and operation principle of fluidized beds,the energy conservation law was adopted to calculate thermal energy of dryers. The thermal energy of fluidized bed dryers is mainly used to make up for thermal consumption of water evaporation (Qw), hot air from outlet equipment (Qe), thermal consumption for heating and drying wet materials (Qm) and heat dissipation to surroundings through hot air pipelines and cyclone separators. Effective measures and major approaches to enhance thermal energy utilization of fluidized bed dryers were to reduce exhaust gas out by the loss of heat Qe, recycle dryer export air quantity of heat, preserve heat for dry towers, hot air pipes and cyclone separators, dehumidify clean air in inlets and reasonably control drying time and air temperature. Such technical parameters such air supply rate, air inlet temperature and humidity, material temperature and outlet temperature and humidity are set and controlled to effectively save energy during the drying process and reduce the production cost.

  16. Numerical investigation of temperature distribution and thermal performance while charging-discharging thermal energy in aquifer

    NARCIS (Netherlands)

    Ganguly, S.; Mohan Kumar, M.S.; Date, Abhijit; Akbarzadeh, Aliakbar

    2017-01-01

    A three-dimensional (3D) coupled thermo-hydrogeological numerical model for a confined aquifer thermal energy storage (ATES) system underlain and overlain by rock media has been presented in this paper. The ATES system operates in cyclic mode. The model takes into account heat transport processes of

  17. Flexible hybrid energy cell for simultaneously harvesting thermal, mechanical, and solar energies.

    Science.gov (United States)

    Yang, Ya; Zhang, Hulin; Zhu, Guang; Lee, Sangmin; Lin, Zong-Hong; Wang, Zhong Lin

    2013-01-22

    We report the first flexible hybrid energy cell that is capable of simultaneously or individually harvesting thermal, mechanical, and solar energies to power some electronic devices. For having both the pyroelectric and piezoelectric properties, a polarized poly(vinylidene fluoride) (PVDF) film-based nanogenerator (NG) was used to harvest thermal and mechanical energies. Using aligned ZnO nanowire arrays grown on the flexible polyester (PET) substrate, a ZnO-poly(3-hexylthiophene) (P3HT) heterojunction solar cell was designed for harvesting solar energy. By integrating the NGs and the solar cells, a hybrid energy cell was fabricated to simultaneously harvest three different types of energies. With the use of a Li-ion battery as the energy storage, the harvested energy can drive four red light-emitting diodes (LEDs).

  18. Thermal energy storage for solar applications: an overview

    Energy Technology Data Exchange (ETDEWEB)

    Wyman, C.

    1979-03-01

    This report presents an overview of current technology and programs including some economic studies in low, intermediate, and high temperatre thermal energy storage for solar applications and an assessment of key problem areas. Previous studies of the economic role of storage for solar home heating and stand-alone electric plants are examined first and factors which affect the economics of storage are discussed. Next, the costs and storage capacities of representative sensible and latent heat storage materials are summarized. Various modes of operation are also presented for thermal storage by reversible chemical reactions, but this technology is at such an immature stage of development that its economic and technical potential are not clearly understood. Some new ideas in containers and heat exchangers are reviewed to illustrate possible innovative approaches to reducing storage costs. A more detailed examination is then made of reversible reaction storage, and gas-solid reactions are shown to have desirable attributes for solar energy storage. However, there are problems with heat transfer and heat exchanger for these systems that must be solved to make such systems more economically attractive. The DOE programs in thermal energy storage are reviewed in light of this review, and recommendations are made for future program directions which appear at this time to have the greatest potential impact on reducing technical and economic barriers to thermal storage utilization.

  19. Nanoparticles for heat transfer and thermal energy storage

    Science.gov (United States)

    Singh, Dileep; Cingarapu, Sreeram; Timofeeva, Elena V.; Moravek, Michael

    2015-07-14

    An article of manufacture and method of preparation thereof. The article of manufacture and method of making the article includes an eutectic salt solution suspensions and a plurality of nanocrystalline phase change material particles having a coating disposed thereon and the particles capable of undergoing the phase change which provides increase in thermal energy storage. In addition, other articles of manufacture can include a nanofluid additive comprised of nanometer-sized particles consisting of copper decorated graphene particles that provide advanced thermal conductivity to heat transfer fluids.

  20. Thermal energy storage for CSP (Concentrating Solar Power

    Directory of Open Access Journals (Sweden)

    Py Xavier

    2017-01-01

    Full Text Available The major advantage of concentrating solar power before photovoltaic is the possibility to store thermal energy at large scale allowing dispatchability. Then, only CSP solar power plants including thermal storage can be operated 24 h/day using exclusively the solar resource. Nevertheless, due to a too low availability in mined nitrate salts, the actual mature technology of the two tanks molten salts cannot be applied to achieve the expected international share in the power production for 2050. Then alternative storage materials are under studies such as natural rocks and recycled ceramics made from industrial wastes. The present paper is a review of those alternative approaches.

  1. Thermal energy storage for CSP (Concentrating Solar Power)

    Science.gov (United States)

    Py, Xavier; Sadiki, Najim; Olives, Régis; Goetz, Vincent; Falcoz, Quentin

    2017-07-01

    The major advantage of concentrating solar power before photovoltaic is the possibility to store thermal energy at large scale allowing dispatchability. Then, only CSP solar power plants including thermal storage can be operated 24 h/day using exclusively the solar resource. Nevertheless, due to a too low availability in mined nitrate salts, the actual mature technology of the two tanks molten salts cannot be applied to achieve the expected international share in the power production for 2050. Then alternative storage materials are under studies such as natural rocks and recycled ceramics made from industrial wastes. The present paper is a review of those alternative approaches.

  2. Effects of thermal annealing on deep-level defects and minority-carrier electron diffusion length in Be-doped InGaAsN

    International Nuclear Information System (INIS)

    Xie, S.Y.; Yoon, S.F.; Wang, S.Z.

    2005-01-01

    We report the effects of ex situ thermal annealing on the deep-level defects and the minority-carrier electron diffusion length in Be-doped, p-type In 0.03 Ga 0.97 As 0.99 N 0.01 grown by solid source molecular-beam epitaxy. Deep-level transient spectroscopy measurements reveal two majority-carrier hole traps, HT1 (0.18 eV) and HT4 (0.59 eV), and two minority-carrier electron traps, ET1 (0.09 eV) and ET3 (0.41 eV), in the as-grown sample. For the sample with postgrowth thermal annealing, the overall deep-level defect-concentration is decreased. Two hole traps, HT2 (0.39 eV) and HT3 (0.41 eV), and one electron trap, ET2 (0.19 eV), are observed. We found that the minority-carrier electron diffusion length increases by ∼30% and the leakage current of the InGaAsN/GaAs p-n junction decreases by 2-3 orders after thermal annealing. An increase of the net acceptor concentration after annealing is also observed and can be explained by a recently proposed three-center-complex model

  3. Scenarios for solar thermal energy applications in Brazil

    International Nuclear Information System (INIS)

    Martins, F.R.; Abreu, S.L.; Pereira, E.B.

    2012-01-01

    The Solar and Wind Energy Resource Assessment (SWERA) database is used to prepare and discuss scenarios for solar thermal applications in Brazil. The paper discusses low temperature applications (small and large scale water heating) and solar power plants for electricity production (concentrated solar power plants and solar chimney plants) in Brazil. The results demonstrate the feasibility of large-scale application of solar energy for water heating and electricity generation in Brazil. Payback periods for water heating systems are typically below 4 years if they were used to replace residential electric showerheads in low-income families. Large-scale water heating systems also present high feasibility and many commercial companies are adopting this technology to reduce operational costs. The best sites to set up CSP plants are in the Brazilian semi-arid region where the annual energy achieves 2.2 MW h/m 2 and averages of daily solar irradiation are larger than 5.0 kW h/m 2 /day. The western area of Brazilian Northeastern region meets all technical requirements to exploit solar thermal energy for electricity generation based on solar chimney technology. Highlights: ► Scenarios for solar thermal applications are presented. ► Payback is typically below 4 years for small scale water heating systems. ► Large-scale water heating systems also present high feasibility. ► The Brazilian semi-arid region is the best sites for CSP and chimney tower plants.

  4. Hydrogen Peroxide as a Sustainable Energy Carrier: Electrocatalytic Production of Hydrogen Peroxide and the Fuel Cell

    Science.gov (United States)

    Fukuzumi, Shunichi; Yamada, Yusuke; Karlin, Kenneth D.

    2012-01-01

    This review describes homogeneous and heterogeneous catalytic reduction of dioxygen with metal complexes focusing on the catalytic two-electron reduction of dioxygen to produce hydrogen peroxide. Whether two-electron reduction of dioxygen to produce hydrogen peroxide or four-electron O2-reduction to produce water occurs depends on the types of metals and ligands that are utilized. Those factors controlling the two processes are discussed in terms of metal-oxygen intermediates involved in the catalysis. Metal complexes acting as catalysts for selective two-electron reduction of oxygen can be utilized as metal complex-modified electrodes in the electrocatalytic reduction to produce hydrogen peroxide. Hydrogen peroxide thus produced can be used as a fuel in a hydrogen peroxide fuel cell. A hydrogen peroxide fuel cell can be operated with a one-compartment structure without a membrane, which is certainly more promising for the development of low-cost fuel cells as compared with two compartment hydrogen fuel cells that require membranes. Hydrogen peroxide is regarded as an environmentally benign energy carrier because it can be produced by the electrocatalytic two-electron reduction of O2, which is abundant in air, using solar cells; the hydrogen peroxide thus produced could then be readily stored and then used as needed to generate electricity through the use of hydrogen peroxide fuel cells. PMID:23457415

  5. Survey of solar thermal energy storage subsystems for thermal/electric applications

    Energy Technology Data Exchange (ETDEWEB)

    Segaser, C. L.

    1978-08-01

    A survey of the current technology and estimated costs of subsystems for storing the thermal energy produced by solar collectors is presented. The systems considered were capable of producing both electricity and space conditioning for three types of loads: a single-family detached residence, an apartment complex of 100 units, and a city of 30,000 residents, containing both single-family residences and apartments. Collector temperatures will be in four ranges: (1) 100 to 250/sup 0/F (used for space heating and single-cycle air conditioners and organic Rankine low-temperature turbines); (2) 300 to 400/sup 0/F (used for dual-cycle air conditioners and low-temperature turbines); (3) 400 to 600/sup 0/F (using fluids from parabolic trough collectors to run Rankine turbines); (4) 800 to 1000/sup 0/F (using fluids from heliostats to run closed-cycle gas turbines and steam Rankine turbines). The solar thermal energy subsystems will require from 60 to 36 x 10/sup 5/ kWhr (2.05 x 10/sup 5/ to 1.23 x 10/sup 10/ Btu) of thermal storage capacity. In addition to sensible heat and latent heat storage materials, several other media were investigated as potential thermal energy storage materials, including the clathrate and semiclathrate hydrates, various metal hydrides, and heat storage based on inorganic chemical reactions.

  6. Thermal modeling with solid/liquid phase change of the thermal energy storage experiment

    Science.gov (United States)

    Skarda, J. Raymond Lee

    1991-01-01

    A thermal model which simulates combined conduction and phase change characteristics of thermal energy storage (TES) materials is presented. Both the model and results are presented for the purpose of benchmarking the conduction and phase change capabilities of recently developed and unvalidated microgravity TES computer programs. Specifically, operation of TES-1 is simulated. A two-dimensional SINDA85 model of the TES experiment in cylindrical coordinates was constructed. The phase change model accounts for latent heat stored in, or released from, a node undergoing melting and freezing.

  7. Thermal energy storage for sustainable energy consumption : fundamentals, case studies and design

    CERN Document Server

    Paksoy, Halime

    2007-01-01

    We all share a small planet. Our growing thirst for energy already threatens the future of our earth. Fossil fuels - energy resources of today - are not evenly distributed on the earth. 10 per cent of the world's population exploits 90 per cent of its resources. Today's energy systems rely heavily on fossil fuel resources which are diminishing ever faster. The world must prepare for a future without fossil fuels. Thermal energy storage provides us with a flexible heating and/or cooling tool to combat climate change through conserving energy and increasing energy while utilizing natural renewab

  8. Lauric Acid Hybridizing Fly Ash Composite for Thermal Energy Storage

    Directory of Open Access Journals (Sweden)

    Dawei Xu

    2018-04-01

    Full Text Available Fly ash includes different mineral phases. This paper reported on the preparation of a novel lauric acid (LA/fly ash (FA composite by vacuum impregnation as a form-stable phase change material (PCM for thermal energy, and especially investigated the effect of the hydrochloric acid-treated fly ash (FAh on the thermal energy storage performance of the composites. The morphology, crystalline structure, and porous textures of the samples were characterized by scanning electron microscopy (SEM, X-ray diffraction (XRD, Brunauer–Emmett–Teller (BET, X-ray fluorescence (XRF, and differential scanning calorimetry (DSC. The results indicated that hydrochloric acid treatment was beneficial to the increase of loading capacity and crystallinity of LA in the LA/FAh composite, which caused an enhanced thermal storage capacity with latent heats for melting and freezing of LA/FAh (80.94 and 77.39 J/g, higher than those of LA/FA (34.09 and 32.97 J/g, respectively. Furthermore, the mechanism of enhanced thermal storage properties was investigated in detail.

  9. Energy band structure tailoring of vertically aligned InAs/GaAsSb quantum dot structure for intermediate-band solar cell application by thermal annealing process.

    Science.gov (United States)

    Liu, Wei-Sheng; Chu, Ting-Fu; Huang, Tien-Hao

    2014-12-15

    This study presents an band-alignment tailoring of a vertically aligned InAs/GaAs(Sb) quantum dot (QD) structure and the extension of the carrier lifetime therein by rapid thermal annealing (RTA). Arrhenius analysis indicates a larger activation energy and thermal stability that results from the suppression of In-Ga intermixing and preservation of the QD heterostructure in an annealed vertically aligned InAs/GaAsSb QD structure. Power-dependent and time-resolved photoluminescence were utilized to demonstrate the extended carrier lifetime from 4.7 to 9.4 ns and elucidate the mechanisms of the antimony aggregation resulting in a band-alignment tailoring from straddling to staggered gap after the RTA process. The significant extension in the carrier lifetime of the columnar InAs/GaAsSb dot structure make the great potential in improving QD intermediate-band solar cell application.

  10. Energy Address Delivery Technologies and Thermal Transformations in Food Production

    Directory of Open Access Journals (Sweden)

    Burdo O.G.

    2016-08-01

    Full Text Available In this article, energetic and technical paradoxes in food nanotechnologies and traditional approaches to evaluation of energy recourses using are considered. Hypotheses of improvement of food production energy technologies are formulated. Classification of principles of address delivery of energy to food raw materials elements is given. We had substantiated the perspective objectives for heat-pumps installations and biphasic heat-transfer systems. The energy efficiency of new technolo-gies is compared on base of the number of energy impact. Principles of mass transfer modeling in ex-traction, dehydration and pasteurization combined processes are considered by food production exam-ple. The objectives of mathematical modeling of combined hydrodynamic and heat and mass transfer processes in modern energy technologies are set. The fuel energy conversion diagrams for drying, in-novative installations on the base of thermal siphons, heat pumps and electromagnetic energy genera-tors are represented. In this article, we illustrate how electromagnetic field, biphasic heat-transfer sys-tems and heat pumps can be effective tools for energy efficiency technologies.

  11. Ocean Thermal Energy Conversion (OTEC) program. FY 1977 program summary

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-01-01

    An overview is given of the ongoing research, development, and demonstration efforts. Each of the DOE's Ocean Thermal Energy Conversion projects funded during fiscal year 1977 (October 1, 1976 through September 30, 1977) is described and each project's status as of December 31, 1977 is reflected. These projects are grouped as follows: program support, definition planning, engineering development, engineering test and evaluation, and advanced research and technology. (MHR)

  12. Dish concentrators for solar thermal energy: Status and technology development

    Science.gov (United States)

    Jaffe, L. D.

    1982-01-01

    Point-focusing concentrators under consideration for solar thermal energy use are reviewed. These concentrators differ in such characteristics as optical configuration, optical materials, structure for support of the optical elements and of the receiver, mount, foundation, drive, controls and enclosure. Concentrator performance and cost are considered. Technology development is outlined, including wind loads and aerodynamics; precipitation, sand, and seismic considerations; and maintenance and cleaning.

  13. Use of natural gas, methanol, and ethanol fuel emulsions as environmentally friendly energy carriers for mobile heat power plants

    Science.gov (United States)

    Likhanov, V. A.; Lopatin, O. P.

    2017-12-01

    The need for using environmentally friendly energy carriers for mobile heat power plants (HPPs) is grounded. Ecologically friendly sources of energy, such as natural gas as well as renewable methyl and ethyl alcohols, are investigated. In order to develop, determine, and optimize the composition of environmentally friendly energy carriers for an HPP, the latter has been tested when working on diesel fuel (DF), compressed natural gas (CNG), and methanol and ethanol fuel emulsions (MFE, EFE). It has been experimentally established that, for the application of environmentally friendly energy carriers for a 4Ch 11.0/12.5 diesel engine of a mobile fuel and power plant, it is necessary to maintain the following ratio of components when working on CNG: 80% gas and 20% DF primer portion. When working on an alcohol mixture, emulsions of the following composition were used: 25% alcohol (methanol or ethanol), 0.5% detergent-dispersant additive succinimide C-5A, 7% water, and 67.5% DF. When this diesel passed from oil DF to environmentally friendly energy sources, it allowed for the reduction of the content of exhaust gases (EG) (1) when working on CNG with recirculation of exhaust gases (EGR) (recirculation was used to eliminate the increased amount of nitric oxides by using CNG): carbon black by 5.8 times, carbon dioxide by 45.9%, and carbon monoxide by 23.8%; (2) when working on MFE: carbon black by 6.4 times, nitrogen oxides by 29.6%, carbon dioxide by 10.1%, and carbon oxide by 47.6%; (3) when working on EFE: carbon black by 4.8 times; nitrogen oxides by 40.3%, carbon dioxide by 26.6%, and carbon monoxide by 28.6%. The prospects of use of environmentally friendly energy carriers in diesels of mobile HPPs, such as natural gas, ethanol, and methanol, has been determined.

  14. Thermal energy storage for industrial waste heat recovery

    Science.gov (United States)

    Hoffman, H. W.; Kedl, R. J.; Duscha, R. A.

    1978-01-01

    The potential is examined for waste heat recovery and reuse through thermal energy storage in five specific industrial categories: (1) primary aluminum, (2) cement, (3) food processing, (4) paper and pulp, and (5) iron and steel. Preliminary results from Phase 1 feasibility studies suggest energy savings through fossil fuel displacement approaching 0.1 quad/yr in the 1985 period. Early implementation of recovery technologies with minimal development appears likely in the food processing and paper and pulp industries; development of the other three categories, though equally desirable, will probably require a greater investment in time and dollars.

  15. Ocean thermal energy: concept and resources, history and perspectives

    International Nuclear Information System (INIS)

    Nihous, Gerard

    2015-10-01

    Two articles address the possibility of exploiting a higher than 20 degrees temperature difference between ocean surfaces and 1 km deep waters to produce electricity. The first article describes the operation principle in closed cycle and briefly presents the open cycle approach. The global energetic assessment is discussed. The author analyses available thermal resources in relationship with the main ocean streams. He outlines that the design of an ocean thermal energy project requires the acquisition and knowledge of a lot of data, modelling and simulations. In the second article, the author notices that past experiments highlighted the difficulties of implementation of the concept. He notably evokes works performed by Georges Claude during the 1920's, projects elaborated at the end of the 20. century, the realisation of a mini OTEC (Ocean Thermal Energy Conversion) station in Hawaii, the OTEC-1 project, a Japanese project in Nauru, the test of a suspended cold water duct, the net power producing experiment in the USA. Perspectives and costs are finally briefly discussed, and recent and promising projects briefly evoked (notably that by DCNS and Akuo Energy in Martinique)

  16. Proceedings of the General Committee for solar thermal energy 2017

    International Nuclear Information System (INIS)

    Loyen, Richard; Gibert, Francois; Porcheyre, Edwige; Laplagne, Valerie; Lambertucci, Stefano; Hauser, Eva; Delmas, Pierre; Mozas, Kevin; Servier, Gerard; Girard, Jean-Paul; Haim, Philippe; Gendron, Marc; Haas, Benjamin; Leclech, Rodrigue; Eberhardt, Mathieu; Bettwy, Fabrice; Berthomieu, Nadine; Barais, Claire; Mingant, Sylvie; Daniel, Charles; GODIN, Olivier; PELe, Charles; Benabdelkarim, Mohamed; Brottier, Laetitia; Cholin, Xavier; Mugnier, Daniel; Marchal, David; Khebchache, Bouzid

    2017-10-01

    The contributions of this conference first proposed an overview of the status and perspectives of the solar thermal energy sector with a presentation of the present situation and perspectives for the French market, and an overview of situations and initiatives in neighbouring European countries. A second session addressed the possible new economical and marketing models able to face challenges of solar thermal energy in 2018 with focuses on heat kWh purchase, on supply portage through a global operator contract (design-realisation-exploitation-maintenance contracts or CREM contracts, energy performance contracts or CPE), and on issues related to building renovation (solar-gas synergy) and to new buildings (regulatory evolution, E+C label). The third session proposed examples of local good practices: development of solar thermal networks in Auvergne-Rhone-Alpes with the development of these networks and a support to commissioners, ADEME's support with patrimony-rehabilitation contracts, and the solar policy implemented by the Brest metropole. A technological focus was then proposed. It addressed communications about the SOCOL approach, concentration-based solar technology (technology, applications, realisations), and solar heating (assets in new and renovated buildings). Before a synthesis, two interventions addressed the production of solar electron and calories, and works performed on the increase of the solar coverage rate

  17. A thermal storage capacity market for non dispatchable renewable energies

    Science.gov (United States)

    Bennouna, El Ghali; Mouaky, Ammar; Arrad, Mouad; Ghennioui, Abdellatif; Mimet, Abdelaziz

    2017-06-01

    Due to the increasingly high capacity of wind power and solar PV in Germany and some other European countries and the high share of variable renewable energy resources in comparison to fossil and nuclear capacity, a power reserve market structured by auction systems was created to facilitate the exchange of balance power capacities between systems and even grid operators. Morocco has a large potential for both wind and solar energy and is engaged in a program to deploy 2000MW of wind capacity by 2020 and 3000 MW of solar capacity by 2030. Although the competitiveness of wind energy is very strong, it appears clearly that the wind program could be even more ambitious than what it is, especially when compared to the large exploitable potential. On the other hand, heavy investments on concentrated solar power plants equipped with thermal energy storage have triggered a few years ago including the launching of the first part of the Nour Ouarzazate complex, the goal being to reach stable, dispatchable and affordable electricity especially during evening peak hours. This paper aims to demonstrate the potential of shared thermal storage capacity between dispatchable and non dispatchable renewable energies and particularly CSP and wind power. Thus highlighting the importance of a storage capacity market in parallel to the power reserve market and the and how it could enhance the development of both wind and CSP market penetration.

  18. Optical and thermal energy discharge from tritiated solid hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Magnotta, F.; Mapoles, E.R.; Collins, G.W.; Souers, P.C.

    1991-04-02

    The authors are investigating mechanisms of energy storage and release in tritiated solid hydrogens, by a variety of techniques including ESR, NMR and thermal and optical emission. The nuclear decay of a triton in solid hydrogen initiates the conversion of nuclear energy into stored chemical energy by producing unpaired hydrogen atoms which are trapped within the molecular lattice. The ability to store large quantities of atoms in this manner has been demonstrated and can serve as a basis for new forms of high energy density materials. This paper presents preliminary results of a study of the optical emission from solid hydrogen containing tritium over the visible and near infrared (NIR) spectral regions. Specifically, they have studied optical emission from DT and T{sub 2} using CCD, silicon diode and germanium diode arrays. 8 refs., 6 figs.

  19. Confinement of solar thermal energy by Nesa film; Nesa maku ni yoru taiyo netsu energy no fujikome

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, A.; Yano, K.; Kasuga, M.; Daigo, Y. [Yamanashi University, Yamanashi (Japan). Faculty of Engineering

    1997-11-25

    This paper reports a Nesa (SnO2) film as selective transmissive film for effective confinement of solar thermal energy. Solar light spectrum ranges from 0.3 to 2.0{mu}m, while thermal radiation from bodies at 100-200degC is infrared ray more than 2{mu}m. Consequently, a solar water heater using the film which can pass rays below 2.0{mu}m while reflect rays over 2.0{mu}m for windows is very efficient. The Nesa film reflects rays with wavelengths more than plasma wavelengths (controllable from 1 to several {mu}m) by plasma action of free electrons. The Nesa films with different carrier densities were fabricated by spraying deposition method at dopant rates (Sb/Sn) from 0 to 2mol%. The solar water heaters were prepared using normal glass and specific glass coated with the Nesa film as selective transmissive film. The heater using the glass coated with the Nesa film of 2{mu}m plasma wavelength for windows could efficiently confine solar heat. The Nesa film of 700nm plasma wavelength which can pass visible light while reflect infrared ray was effective to reduce cooling/heating losses. 3 refs., 6 figs.

  20. THERMAL-ENERGY STORAGE IN A DEEP SANDSTONE AQUIFER IN MINNESOTA: FIELD OBSERVATIONS AND THERMAL ENERGY-TRANSPORT MODELING.

    Science.gov (United States)

    Miller, R.T.

    1986-01-01

    A study of the feasibility of storing heated water in a deep sandstone aquifer in Minnesota is described. The aquifer consists of four hydraulic zones that are areally anisotropic and have average hydraulic conductivities that range from 0. 03 to 1. 2 meters per day. A preliminary axially symmetric, nonisothermal, isotropic, single-phase, radial-flow, thermal-energy-transport model was constructed to investigate the sensitivity of model simulation to various hydraulic and thermal properties of the aquifer. A three-dimensional flow and thermal-energy transport model was constructed to incorporate the areal anisotropy of the aquifer. Analytical solutions of equations describing areally anisotropic groundwater flow around a doublet-well system were used to specify model boundary conditions for simulation of heat injection. The entire heat-injection-testing period of approximately 400 days was simulated. Model-computed temperatures compared favorably with field-recorded temperatures, with differences of no more than plus or minus 8 degree C. For each test cycle, model-computed aquifer thermal efficiency, defined as total heat withdrawn divided by total heat injected, was within plus or minus 2% of the field-calculated values.

  1. The thermal impact of aquifer thermal energy storage (ATES) systems: a case study in the Netherlands, combining monitoring and modeling

    NARCIS (Netherlands)

    Visser, P.W.; Kooi, H.; Stuijfzand, P.J.

    2014-01-01

    Results are presented of a comprehensive thermal impact study on an aquifer thermal energy storage (ATES) system in Bilthoven, the Netherlands. The study involved monitoring of the thermal impact and modeling of the three-dimensional temperature evolution of the storage aquifer and over- and

  2. Thermal properties of a novel nanoencapsulated phase change material for thermal energy storage

    International Nuclear Information System (INIS)

    Fuensanta, Mónica; Paiphansiri, Umaporn; Romero-Sánchez, María Dolores; Guillem, Celia; López-Buendía, Ángel M.; Landfester, Katharina

    2013-01-01

    Highlights: • A paraffin wax RT80 was encapsulated in styrene–butyl acrylate copolymer as polymer shell using miniemulsion polymerization process to obtain a novel nanoencapsulated PCM with 80 °C melting temperature. • Nano-PCMs have high compact structure, spherical morphology and thermal stability. • The nano-PCMs have potential applications as thermal energy storage materials. - Abstract: A novel nanoencapsulation of a paraffine type phase change material, RT80, in a styrene–butyl acrylate copolymer shell using the miniemulsion polymerization process was carried out. General characteristics of the RT80 nanoparticles in terms of thermal properties, morphology, chemical composition and particle size distribution were characterized by Differential Scanning Calorimetry (DSC), Thermal Gravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FT-IR) and Dynamic Light Scattering (DLS). The influence of different monomers (styrene, butyl acrylate) and the surfactant/paraffin mass ratios on nanoparticles properties such as thermal capacity, particle size and morphology were systematically investigated. In all cases studied, encapsulation efficiency was close to 80 wt% with a particle size distribution between 52 and 112 nm and regular spherical shape and uniform structure. The amount of encapsulated paraffin achieved was comprised between 8 and 20%. Melting and crystallization heats were found to be approximately 5–25 J g −1 , mainly depending on surfactant/paraffin mass ratio. Melting temperature of RT80 nanoparticles slightly decreased (1–7 °C) respect to the raw RT80. In addition, the encapsulated RT80 nanoparticles show thermal stability even after 200 thermal (heat-cooling) cycles

  3. Numerical Modeling of a Shallow Borehole Thermal Energy Storage System

    Science.gov (United States)

    Catolico, N.; Ge, S.; Lu, N.; McCartney, J. S.

    2014-12-01

    Borehole thermal energy storage (BTES) combined with solar thermal energy harvesting is an economic technological system to garner and store energy as well as an environmentally-sustainable alternative for the heating of buildings. The first community-scale BTES system in North America was installed in 2007 in the Drake Landing Solar Community (DLSC), about 35 miles south of Calgary, Canada. The BTES system involves direct circulation of water heated from solar thermal panels in the summer into a storage tank, after which it is circulate within an array of 144 closed-loop geothermal heat exchangers having a depth of 35 m and a spacing of 2.5 m. In the winter the circulation direction is reversed to supply heat to houses. Data collection over a six year period indicates that this system can supply more than 90% of the winter heating energy needs for 52 houses in the community. One major challenge facing the BTES system technology is the relatively low annual efficiency, i.e., the ratio of energy input and output is in the range of 15% to 40% for the system in Drake Landing. To better understand the working principles of BTES and to improve BTES performance for future applications at larger scales, a three-dimensional transient coupled fluid and heat transfer model is established using TOUGH2. The time-dependent injection temperatures and circulation rate measured over the six years of monitoring are used as model input. The simulations are calibrated using soil temperature data measured at different locations over time. The time-dependent temperature distributions within the borehole region agree well with the measured temperatures for soil with an intrinsic permeability of 10e-19 m2, an apparent thermal conductivity of 2.03 W/m°C, and a volumetric heat capacity of 2.31 MJ/m-3°C. The calibrated model serves as the basis for a sensitivity analysis of soil and operational parameters on BTES system efficiency preformed with TOUGH2. Preliminary results suggest 1) BTES

  4. Testing of High Thermal Cycling Stability of Low Strength Concrete as a Thermal Energy Storage Material

    Directory of Open Access Journals (Sweden)

    Chao Wu

    2016-09-01

    Full Text Available Concrete has the potential to become a solution for thermal energy storage (TES integrated in concentrating solar power (CSP systems due to its good thermal and mechanical properties and low cost of material. In this study, a low strength concrete (C20 is tested at high temperatures up to 600 °C. Specimens are thermally cycled at temperatures in the range of 400–300 °C, 500–300 °C, and 600–300 °C, which TES can reach in operation. For comparison, specimens also cycled at temperature in the range of 400–25 °C (room temperature, 500–25 °C, and 600–25 °C. It is found from the test results that cracks are not observed on the surfaces of concrete specimens until the temperature is elevated up to 500 °C. There is mechanical deterioration of concrete after exposure to high temperature, especially to high thermal cycles. The residual compressive strength of concrete after 10 thermal cycles between 600 °C and 300 °C is about 58.3%, but the specimens remain stable without spalling, indicating possible use of low strength concrete as a TES material.

  5. Advances in Thermal Insulation. Vacuum Insulation Panels and Thermal Efficiency to Reduce Energy Usage in Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Thorsell, Thomas

    2012-07-01

    We are coming to realize that there is an urgent need to reduce energy usage in buildings and it has to be done in a sustainable way. This thesis focuses on the performance of the building envelope; more precisely thermal performance of walls and super insulation material in the form of vacuum insulation. However, the building envelope is just one part of the whole building system, and super insulators have one major flaw: they are easily adversely affected by other problems in the built environment. Vacuum Insulation Panels are one fresh addition to the arsenal of insulation materials available to the building industry. They are composite material with a core and an enclosure which, as a composite, can reach thermal conductivities as low as 0.004 W/(mK). However, the exceptional performance relies on the barrier material preventing gas permeation, maintaining a near vacuum into the core and a minimized thermal bridge effect from the wrapping of barrier material round the edge of a panel. A serpentine edge is proposed to decrease the heat loss at the edge. Modeling and testing shows a reduction of 60 % if a reasonable serpentine edge is used. A diffusion model of permeation through multilayered barrier films with metallization coatings was developed to predict ultimate service life. The model combines numerical calculations with analytical field theory allowing for more precise determination than current models. The results using the proposed model indicate that it is possible to manufacture panels with lifetimes exceeding 50 years with existing manufacturing. Switching from the component scale to the building scale; an approach of integrated testing and modeling is proposed. Four wall types have been tested in a large range of environments with the aim to assess the hydrothermal nature and significance of thermal bridges and air leakages. The test procedure was also examined as a means for a more representative performance indicator than R-value (in USA). The

  6. Preliminary investigations of the thermal energy grid concept

    Energy Technology Data Exchange (ETDEWEB)

    Olszewski, M.

    1977-10-01

    This study examines, in a preliminary manner, the feasibility of the thermal grid concept. This concept essentially envisions the supply of heat to a long-distance transmission line from a dual-purpose nuclear or coal-fired power plant. The transmission line delivers heat to a subregion distribution network which delivers it to the consumer. District chilled water supply is also considered, using heat from the grid to power steam-turbine-driven water chillers. Candidate technologies for generation, transmission, and distribution of thermal energy are identified and assessed. Potential applications, including both industrial use and residential space conditioning and hot water supply, are evaluated. Results indicate that high-temperature hot-water transmission lines are favored for longer distances, while steam lines may be acceptable for shorter distances. It is also evident that thermal grid heat is more economically competitive for new applications, as opposed to retrofit situations, in the residential-commercial sector. The two applications are about equally feasible in the industrial sector. The results further indicate that thermal grid heat is most competitive in areas of high-heat-load density and expensive fuel costs. It appears that the thermal grid service area should include the industrial sector as a base load. The multifamily residential-commercial sector space and water heating loads can be added to the service area to maximize utilization of the transmission line and maintain low transmission costs. Supply of chilled water to the multifamily residential-commercial sector can also be included for new applications to increase the transmission line use factor. The thermal grid concept appears to be economically and technically feasible, when compared to oil and electric systems in the multifamily residential-commercial sector and coal- or oil-fired systems in the industrial sector, and should be explored in greater detail.

  7. Thermal energy storage for coal-fired power generation

    Energy Technology Data Exchange (ETDEWEB)

    Drost, M.K.; Somasundaram, S.; Brown, D.R.; Antoniak, Z.I.

    1990-11-01

    This paper presents an engineering and economic evaluation of using thermal energy storage (TES) with coal-fired conventional and combined cycle power plants. In the first case, conventional pulverized coal combustion equipment was assumed to continuously operate to heat molten nitrate salt which was then stored in a tank. During intermediate-load demand periods, hot salt was withdrawn from storage and used to generate steam for a Rankine steam power cycle. This allowed the coal-fired salt heater to be approximately one-third the size of a coal-fired boiler in a conventional cycling plant. The use of nitrate salt TES also reduced the levelized cost of power by between 5% and 24% depends on the operating schedule. The second case evaluate the use of thermal energy storage with an integrated gasification combined cycle (IGCC) power plant. In this concept, the nitrate salt was heated by a combination of the gas turbine exhaust and the hot fuel gas. The IGCC plant also contained a low-temperature storage unit that uses a mixture of oil and rock as the thermal storage medium. Thermal energy stored in the low-temperature TES was used to preheat the feedwater after it leaves the condenser and to produce process steam for other applications in the IGCC plant. This concept study also predicted a 5% to 20% reduction in levelized cost of power compared to other coal-fired alternatives. If significant escalation rates in the price of fuel were assumed, the concept could be competitive with natural-gas-fired intermediate-load power generation. A sensitivity analysis of using a direct-contact heat exchanger instead of the conventional finned-tube design showed a significant reduction in the installed capital cost. 3 refs., 2 figs., 6 tabs.

  8. Thermal Energy Optimization of Building Integrated Semi-Transparent Photovoltaic Thermal Systems

    OpenAIRE

    Martial, Ekoe A Akata Aloys; Njomo, Donatien; Agrawal, Basant

    2015-01-01

    Building integrated photovoltaic (BIPV) : The concept where the photovoltaic element assumes the function of power generation and the role of the covering component element has the potential to become one of the principal sources of renewable energy for domestic purpose. In this paper, a Building integrated semitransparent photovoltaic thermal system (BISPVT) system having fins at the back sheet of the photovoltaic module has been simulated. It has been observed that this system produces high...

  9. Thermal transfer performance of a spherical encapsulated PEG 6000-based composite for thermal energy storage

    Czech Academy of Sciences Publication Activity Database

    Anghel, E.M.; Pavel, P.M.; Constantinescu, M.; Petrescu, S.; Atkinson, I.; Buixaderas, Elena

    2017-01-01

    Roč. 208, Sep (2017), s. 1222-1231 ISSN 0306-2619 Grant - others:AV ČR(CZ) AR-17-02 Program:Bilaterální spolupráce Institutional support: RVO:68378271 Keywords : phase change materials * thermal energy storage * modeling Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 7.182, year: 2016

  10. Using Paraffin with -10 deg C to 10 deg C Melting Point for Payload Thermal Energy Storage in SpaceX Dragon Trunk

    Science.gov (United States)

    Choi, Michael K.

    2013-01-01

    A concept of using paraffin wax phase change material (PCM) with a melting point between -10 deg C and 10 deg C for payload thermal energy storage in a Space Exploration Technologies (SpaceX) Dragon trunk is presented. It overcomes the problem of limited heater power available to a payload with significant radiators when the Dragon is berthed to the International Space Station (ISS). It stores adequate thermal energy to keep a payload warm without power for 6 hours during the transfer from the Dragon to an ExPRESS logistics carrier (ELC) on the ISS.

  11. Subsurface Thermal Energy Storage for Improved Heating and Air Conditioning Efficiency

    Science.gov (United States)

    2016-11-21

    FINAL REPORT Subsurface Thermal Energy Storage for Improved Heating and Air Conditioning Efficiency ESTCP Project EW-201013 NOVEMBER 2016 Ronald...TITLE AND SUBTITLE Final Report. Subsurface Thermal Energy Storage for Improved 5a. CONTRACT NUMBER 10-C-0027-A Air Conditioning...This project involved a field demonstration of subsurface thermal energy storage for improving the geothermal heat pump air conditioning efficiency

  12. Coupling Geothermal Heat Pumps with Underground Seasonal Thermal Energy Storage (EW-201135)

    Science.gov (United States)

    2017-03-01

    FINAL REPORT Coupling Geothermal Heat Pumps with Underground Seasonal Thermal Energy Storage ESTCP Project EW-201135 MARCH 2017...TITLE AND SUBTITLE Coupling Geothermal Heat Pumps with Underground Seasonal Thermal Energy Storage 5a. CONTRACT NUMBER 5b...LIST OF FIGURES Page Figure 2.1. Borehole Thermal Energy Storage (BTES) Overview ............................................................ 8

  13. Coupling Geothermal Heat Pumps (GHP) With Underground Seasonal Thermal Energy Storage (USTES)

    Science.gov (United States)

    2017-03-21

    TECHNICAL GUIDANCE Coupling Geothermal Heat Pumps (GHP) With Underground Seasonal Thermal Energy Storage (USTES) ESTCP Project EW-201135 MARCH...Geothermal Heat Pumps with Underground Seasonal Thermal Energy Storage 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...Geothermal Heat Pumps, thermal , energy storage Page Intentionally Left Blank i TECHNICAL & ENVIRONMENTAL

  14. Economic Evaluation of a Solar Charged Thermal Energy Store for Space Heating

    OpenAIRE

    Melo, Manuel

    2013-01-01

    A thermal energy store corrects the misalignment of heating demand in the winter relative to solar thermal energy gathered in the summer. This thesis reviews the viability of a solar charged hot water tank thermal energy store for a school at latitude 56.25N, longitude -120.85W

  15. Determination of hydrogen in zirconium and its alloys by melt extraction under carrier gas flow using thermal conductivity cell as detector

    International Nuclear Information System (INIS)

    Akhtar, J.; Ahmed, M.; Mohammad, B.; Jan, S.; Waqar, F.

    1987-06-01

    In the production of zirconium metal and its alloys the presence of hydrogen impurity affects mechanical and corrosion resistance properties of the product. Therefore, determination of hydrogen contents of the product is necessary. Conditions for its analysis by melt extraction under carrier gas stream using thermal conductivity cell as detector were studied and optimised. The method is capable of measuring hydrogen impurity in parts per million range. (author)

  16. Numerical modeling of Thermal Response Tests in Energy Piles

    Science.gov (United States)

    Franco, A.; Toledo, M.; Moffat, R.; Herrera, P. A.

    2013-05-01

    Nowadays, thermal response tests (TRT) are used as the main tools for the evaluation of low enthalpy geothermal systems such as heat exchangers. The results of TRT are used for estimating thermal conductivity and thermal resistance values of those systems. We present results of synthetic TRT simulations that model the behavior observed in an experimental energy pile system, which was installed at the new building of the Faculty of Engineering of Universidad de Chile. Moreover, we also present a parametric study to identify the most influent parameters in the performance of this type of tests. The modeling was developed using the finite element software COMSOL Multiphysics, which allows the incorporation of flow and heat transport processes. The modeled system consists on a concrete pile with 1 m diameter and 28 m deep, which contains a 28 mm diameter PEX pipe arranged in a closed circuit. Three configurations were analyzed: a U pipe, a triple U and a helicoid shape implemented at the experimental site. All simulations were run considering transient response in a three-dimensional domain. The simulation results provided the temperature distribution on the pile for a set of different geometry and physical properties of the materials. These results were compared with analytical solutions which are commonly used to interpret TRT data. This analysis demonstrated that there are several parameters that affect the system response in a synthetic TRT. For example, the diameter of the simulated pile affects the estimated effective thermal conductivity of the system. Moreover, the simulation results show that the estimated thermal conductivity for a 1 m diameter pile did not stabilize even after 100 hours since the beginning of the test, when it reached a value 30% below value used to set up the material properties in the simulation. Furthermore, we observed different behaviors depending on the thermal properties of concrete and soil. According to the simulations, the thermal

  17. Sodium-based hydrides for thermal energy applications

    Science.gov (United States)

    Sheppard, D. A.; Humphries, T. D.; Buckley, C. E.

    2016-04-01

    Concentrating solar-thermal power (CSP) with thermal energy storage (TES) represents an attractive alternative to conventional fossil fuels for base-load power generation. Sodium alanate (NaAlH4) is a well-known sodium-based complex metal hydride but, more recently, high-temperature sodium-based complex metal hydrides have been considered for TES. This review considers the current state of the art for NaH, NaMgH3- x F x , Na-based transition metal hydrides, NaBH4 and Na3AlH6 for TES and heat pumping applications. These metal hydrides have a number of advantages over other classes of heat storage materials such as high thermal energy storage capacity, low volume, relatively low cost and a wide range of operating temperatures (100 °C to more than 650 °C). Potential safety issues associated with the use of high-temperature sodium-based hydrides are also addressed.

  18. Energy Efficiency Enhancement of Photovoltaics by Phase Change Materials through Thermal Energy Recovery

    Directory of Open Access Journals (Sweden)

    Ahmad Hasan

    2016-09-01

    Full Text Available Photovoltaic (PV panels convert a certain amount of incident solar radiation into electricity, while the rest is converted to heat, leading to a temperature rise in the PV. This elevated temperature deteriorates the power output and induces structural degradation, resulting in reduced PV lifespan. One potential solution entails PV thermal management employing active and passive means. The traditional passive means are found to be largely ineffective, while active means are considered to be energy intensive. A passive thermal management system using phase change materials (PCMs can effectively limit PV temperature rises. The PCM-based approach however is cost inefficient unless the stored thermal energy is recovered effectively. The current article investigates a way to utilize the thermal energy stored in the PCM behind the PV for domestic water heating applications. The system is evaluated in the winter conditions of UAE to deliver heat during water heating demand periods. The proposed system achieved a ~1.3% increase in PV electrical conversion efficiency, along with the recovery of ~41% of the thermal energy compared to the incident solar radiation.

  19. Thermal energy storage. [by means of chemical reactions

    Science.gov (United States)

    Grodzka, P. G.

    1975-01-01

    The principles involved in thermal energy storage by sensible heat, chemical potential energy, and latent heat of fusion are examined for the purpose of evolving selection criteria for material candidates in the low ( 0 C) and high ( 100 C) temperature ranges. The examination identifies some unresolved theoretical considerations and permits a preliminary formulation of an energy storage theory. A number of candidates in the low and high temperature ranges are presented along with a rating of candidates or potential candidates. A few interesting candidates in the 0 to 100 C region are also included. It is concluded that storage by means of reactions whose reversibility can be controlled either by product removal or by catalytic means appear to offer appreciable advantages over storage with reactions whose reversability cannot be controlled. Among such advantages are listed higher heat storage capacities and more favorable options regarding temperatures of collection, storage, and delivery. Among the disadvantages are lower storage efficiencies.

  20. High Efficiency and Low Cost Thermal Energy Storage System

    Energy Technology Data Exchange (ETDEWEB)

    Sienicki, James J. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Lv, Qiuping [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Moisseytsev, Anton [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Bucknor, Matthew [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division

    2017-09-29

    BgtL, LLC (BgtL) is focused on developing and commercializing its proprietary compact technology for processes in the energy sector. One such application is a compact high efficiency Thermal Energy Storage (TES) system that utilizes the heat of fusion through phase change between solid and liquid to store and release energy at high temperatures and incorporate state-of-the-art insulation to minimize heat dissipation. BgtL’s TES system would greatly improve the economics of existing nuclear and coal-fired power plants by allowing the power plant to store energy when power prices are low and sell power into the grid when prices are high. Compared to existing battery storage technology, BgtL’s novel thermal energy storage solution can be significantly less costly to acquire and maintain, does not have any waste or environmental emissions, and does not deteriorate over time; it can keep constant efficiency and operates cleanly and safely. BgtL’s engineers are experienced in this field and are able to design and engineer such a system to a specific power plant’s requirements. BgtL also has a strong manufacturing partner to fabricate the system such that it qualifies for an ASME code stamp. BgtL’s vision is to be the leading provider of compact systems for various applications including energy storage. BgtL requests that all technical information about the TES designs be protected as proprietary information. To honor that request, only non-proprietay summaries are included in this report.

  1. Analyzing Control Challenges for Thermal Energy Storage in Foodstuffs

    DEFF Research Database (Denmark)

    Hovgaard, Tobias Gybel; Larsen, Lars F. S.; Skovrup, Morten Juel

    2012-01-01

    of refrigerated goods in a supermarket to shift the load of the system in time without deteriorating the quality of the foodstuffs. The analyses in this paper go before closing any control loops. In the first part, we introduce and validate a new model with which we can estimate the actual temperatures...... of refrigerated goods from available air temperature measurements. This is based on data obtained from a dedicated experiment. Since limits are specified for food temperatures, the estimate is essential for full exploitation of the thermal potential. Secondly, the thermal properties, shapes and sizes of different...... and for estimating maximum energy storage time. The results are shown for a large range of parameters, and with specific calculations for selected foodstuff items....

  2. Development of thermal energy storage materials for biomedical applications.

    Science.gov (United States)

    Shukla, A; Sharma, Atul; Shukla, Manjari; Chen, C R

    2015-01-01

    The phase change materials (PCMs) have been utilized widely for solar thermal energy storage (TES) devices. The quality of these materials to remain at a particular temperature during solid-liquid, liquid-solid phase transition can also be utilized for many biomedical applications as well and has been explored in recent past already. This study reports some novel PCMs developed by them, along with some existing PCMs, to be used for such biomedical applications. Interestingly, it was observed that the heating/cooling properties of these PCMs enhance the quality of a variety of biomedical applications with many advantages (non-electric, no risk of electric shock, easy to handle, easy to recharge thermally, long life, cheap and easily available, reusable) over existing applications. Results of the present study are quite interesting and exciting, opening a plethora of opportunities for more work on the subject, which require overlapping expertise of material scientists, biochemists and medical experts for broader social benefits.

  3. A survey of manufacturers of solar thermal energy systems

    Science.gov (United States)

    Levine, N.; Slonski, M. L.

    1982-01-01

    Sixty-seven firms that had received funding for development of solar thermal energy systems (STES) were surveyed. The effect of the solar thermal technology systems program in accelerating (STES) were assessed. The 54 firms still developing STES were grouped into a production typology comparing the three major technologies with three basic functions. It was discovered that large and small firms were developing primarily central receiver systems, but also typically worked on more than one technology. Most medium-sized firms worked only on distributed systems. Federal support of STES was perceived as necessary to allow producers to take otherwise unacceptable risks. Approximately half of the respondents would drop out of STES if support were terminated, including a disproportionate number of medium-sized firms. A differentiated view of the technology, taking into account differing firm sizes and the various stages of technology development, was suggested for policy and planning purposes.

  4. Thermal Energy Corporation Combined Heat and Power Project

    Energy Technology Data Exchange (ETDEWEB)

    Turner, E. Bruce [Thermal Energy Corporation, Houston, TX (United States); Brown, Tim [Thermal Energy Corporation, Houston, TX (United States); Mardiat, Ed [Burns and McDonnell Engineering Company, Inc., Kansas City, MI (United States)

    2011-12-31

    To meet the planned heating and cooling load growth at the Texas Medical Center (TMC), Thermal Energy Corporation (TECO) implemented Phase 1 of a Master Plan to install an additional 32,000 tons of chilled water capacity, a 75,000 ton-hour (8.8 million gallon) Thermal Energy Storage (TES) tank, and a 48 MW Combined Heat and Power (CHP) system. The Department of Energy selected TMC for a $10 million grant award as part of the Financial Assistance Funding Opportunity Announcement, U.S. Department of Energy National Energy Technology, Recovery Act: Deployment of Combined Heat and Power (CHP) Systems, District Energy Systems, Waste Energy Recovery Systems, and Efficiency Industrial Equipment Funding Opportunity Number: DE-FOA-0000044 to support the installation of a new 48 MW CHP system at the TMC located just outside downtown Houston. As the largest medical center in the world, TMC is home to many of the nation's best hospitals, physicians, researchers, educational institutions, and health care providers. TMC provides care to approximately six million patients each year, and medical instruction to over 71,000 students. A medical center the size of TMC has enormous electricity and thermal energy demands to help it carry out its mission. Reliable, high-quality steam and chilled water are of utmost importance to the operations of its many facilities. For example, advanced medical equipment, laboratories, laundry facilities, space heating and cooling all rely on the generation of heat and power. As result of this project TECO provides this mission critical heating and cooling to TMC utilizing a system that is both energy-efficient and reliable since it provides the capability to run on power independent of the already strained regional electric grid. This allows the medical center to focus on its primary mission providing top quality medical care and instruction without worrying about excessive energy costs or the loss of heating and cooling due to the risk of power

  5. Feasibility study of thermal energy harvesting using lead free pyroelectrics

    Science.gov (United States)

    Karim, Hasanul; Sarker, Md Rashedul H.; Shahriar, Shaimum; Arif Ishtiaque Shuvo, Mohammad; Delfin, Diego; Hodges, Deidra; (Bill Tseng, Tzu-Liang; Roberson, David; Love, Norman; Lin, Yirong

    2016-05-01

    Energy harvesting has significant potential for applications in energizing wireless sensors and charging energy storage devices. To date, one of the most widely investigated materials for mechanical and thermal energy harvesting is lead zirconate titanate (PZT). However, lead has detrimental effects on the environment and on health. Hence, alternative materials are required for this purpose. In this paper, a lead free material, lithium niobate (LNB) is investigated as a potential material for pyroelectric energy harvesting. Although its theoretical pyroelectric properties are lower compared to PZT, it has better properties than other lead free alternatives such as ZnO. In addition, LNB has a high Curie temperature of about 1142 °C, which makes it applicable for high temperature energy harvesting, where other pyroelectric ceramics are not suitable. Herein, an energy harvesting and storage system composed of a single crystal LNB and a porous carbon-based super-capacitor was investigated. It is found that with controlled heating and cooling, a single wafer of LNB (75 mm diameter and 0.5 mm thickness) could generate 437.72 nW cm-3 of power and it could be used to charge a super-capacitor with a charging rate of 2.63 mV (h cm3)-1.

  6. Thermal dynamic simulation of wall for building energy efficiency under varied climate environment

    Science.gov (United States)

    Wang, Xuejin; Zhang, Yujin; Hong, Jing

    2017-08-01

    Aiming at different kind of walls in five cities of different zoning for thermal design, using thermal instantaneous response factors method, the author develops software to calculation air conditioning cooling load temperature, thermal response factors, and periodic response factors. On the basis of the data, the author gives the net work analysis about the influence of dynamic thermal of wall on air-conditioning load and thermal environment in building of different zoning for thermal design regional, and put forward the strategy how to design thermal insulation and heat preservation wall base on dynamic thermal characteristic of wall under different zoning for thermal design regional. And then provide the theory basis and the technical references for the further study on the heat preservation with the insulation are in the service of energy saving wall design. All-year thermal dynamic load simulating and energy consumption analysis for new energy-saving building is very important in building environment. This software will provide the referable scientific foundation for all-year new thermal dynamic load simulation, energy consumption analysis, building environment systems control, carrying through farther research on thermal particularity and general particularity evaluation for new energy -saving walls building. Based on which, we will not only expediently design system of building energy, but also analyze building energy consumption and carry through scientific energy management. The study will provide the referable scientific foundation for carrying through farther research on thermal particularity and general particularity evaluation for new energy saving walls building.

  7. U.S. Department of Energy thermal energy storage research activities review: 1989 Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, H.W. [ed.] [PAI Corp., Oak Ridge, TN (United States); Tomlinson, J.J. [ed.] [Oak Ridge National Lab., TN (United States)

    1989-03-01

    Thermal Energy Storage (TES) offers the opportunity for the recovery and re-use of heat currently rejected to the ambient environment. Further, through the ability of TES to match an energy supply with a thermal energy demand, TES increases efficiencies of energy systems and improves capacity factors of power plants. The US Department of Energy has been the leader in TES research, development, and demonstration since recognition in 1976 of the need for fostering energy conservation as a component of the national energy budget. The federal program on TES R and D is the responsibility of the Office of Energy Storage and Distribution within the US Department of Energy (DOE). The overall program is organized into three program areas: diurnal--relating primarily to lower temperature heat for use in residential and commercial buildings on a daily cycle; industrial--relating primarily to higher temperature heat for use in industrial and utility processes on an hourly to daily cycle; seasonal--relating primarily to lower temperature heat or chill for use in residential complexes (central supply as for apartments or housing developments), commercial (light manufacturing, processing, or retail), and industrial (space conditioning) on a seasonal to annual cycle. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  8. Significant thermal energy reduction in lactic acid production process

    International Nuclear Information System (INIS)

    Mujtaba, Iqbal M.; Edreder, Elmahboub A.; Emtir, Mansour

    2012-01-01

    Lactic acid is widely used as a raw material for the production of biodegradable polymers and in food, chemical and pharmaceutical industries. The global market for lactic acid is expected to reach 259 thousand metric tons by the year 2012. For batch production of lactic acid, the traditional process includes the following steps: (i) esterification of impure lactic acid with methanol in a batch reactor to obtain methyl lactate (ester), (ii) separation of the ester in a batch distillation, (iii) hydrolysis of the ester with water in a batch reactor to produce lactic acid and (iv) separation of lactic acid (in high purity) in a batch distillation. Batch reactive distillation combines the benefit of both batch reactor and batch distillation and enhances conversion and productivity (Taylor and Krishna, 2000 ; Mujtaba and Macchietto, 1997 ). Therefore, the first and the last two steps of the lactic acid production process can be combined together in batch reactive distillation () processes. However, distillation (batch or continuous) is an energy intensive process and consumes large amount of thermal energy (via steam). This paper highlights how significant (over 50%) reduction in thermal energy consumption can be achieved for lactic acid production process by carefully controlling the reflux ratio but without compromising the product specification. In this paper, only the simultaneous hydrolysis of methyl lactate ester and the separation of lactic acid using batch reactive distillation is considered.

  9. ANALYSIS OF THERMAL-CHEMICAL CHARACTERISTICS OF BIOMASS ENERGY PELLETS

    Directory of Open Access Journals (Sweden)

    Zorica Gluvakov

    2014-09-01

    Full Text Available In modern life conditions, when emphasis is on environmental protection and sustainable development, fuels produced from biomass are increasingly gaining in importance, and it is necessary to consider the quality of end products obtained from biomass. Based on the existing European standards, collected literature and existing laboratory methods, this paper presents results of testing individual thermal - chemical properties of biomass energy pellets after extrusion and cooling the compressed material. Analysing samples based on standard methods, data were obtained on the basis of which individual thermal-chemical properties of pellets were estimated. Comparing the obtained results with the standards and literature sources, it can be said that moisture content, ash content and calorific values are the most important parameters for quality analysis which decide on applicability and use-value of biomass energy pellets, as biofuel. This paper also shows the impact of biofuels on the quality of environmental protection. The conclusion provides a clear statement of quality of biomass energy pellets.

  10. Thermal Impact of Medium Deep Borehole Thermal Energy Storage on the Shallow Subsurface

    Science.gov (United States)

    Welsch, Bastian; Schulte, Daniel O.; Rühaak, Wolfram; Bär, Kristian; Sass, Ingo

    2017-04-01

    Borehole heat exchanger arrays are a well-suited and already widely applied method for exploiting the shallow subsurface as seasonal heat storage. However, in most of the populated regions the shallow subsurface also comprises an important aquifer system used for drinking water production. Thus, the operation of shallow geothermal heat storage systems leads to a significant increase in groundwater temperatures in the proximity of the borehole heat exchanger array. The magnitude of the impact on groundwater quality and microbiology associated with this temperature rise is controversially discussed. Nevertheless, the protection of shallow groundwater resources has priority. Accordingly, water authorities often follow restrictive permission policies for building such storage systems. An alternative approach to avoid this issue is the application of medium deep borehole heat exchanger arrays instead of shallow ones. The thermal impact on shallow aquifers can be significantly reduced as heat is stored at larger depth. Moreover, it can be further diminished by the installation of a thermally insulating materials in the upper section of the borehole heat exchangers. Based on a numerical simulation study, the advantageous effects of medium deep borehole thermal energy storage are demonstrated and quantified. A finite element software is used to model the heat transport in the subsurface in 3D, while the heat transport in the borehole heat exchangers is solved analytically in 1D. For this purpose, an extended analytical solution is implemented, which also allows for the consideration of a thermally insulating borehole section.

  11. Heat exchange studies on coconut oil cells as thermal energy storage for room thermal conditioning

    Science.gov (United States)

    Sutjahja, I. M.; Putri, Widya A.; Fahmi, Z.; Wonorahardjo, S.; Kurnia, D.

    2017-07-01

    As reported by many thermal environment experts, room air conditioning might be controlled by thermal mass system. In this paper we discuss the performance of coconut oil cells as room thermal energy storage. The heat exchange mechanism of coconut oil (CO) which is one of potential organic Phase Change Material (PCM) is studied based on the results of temperature measurements in the perimeter and core parts of cells. We found that the heat exchange performance, i.e. heat absorption and heat release processes of CO cells are dominated by heat conduction in the sensible solid from the higher temperature perimeter part to the lower temperature core part and heat convection during the solid-liquid phase transition and sensible liquid phase. The capability of heat absorption as measured by the reduction of air temperature is not influenced by CO cell size. Besides that, the application of CO as the thermal mass has to be accompanied by air circulation to get the cool sensation of the room’s occupants.

  12. Azobenzene-functionalized carbon nanotubes as high-energy density solar thermal fuels.

    Science.gov (United States)

    Kolpak, Alexie M; Grossman, Jeffrey C

    2011-08-10

    Solar thermal fuels, which reversibly store solar energy in molecular bonds, are a tantalizing prospect for clean, renewable, and transportable energy conversion/storage. However, large-scale adoption requires enhanced energy storage capacity and thermal stability. Here we present a novel solar thermal fuel, composed of azobenzene-functionalized carbon nanotubes, with the volumetric energy density of Li-ion batteries. Our work also demonstrates that the inclusion of nanoscale templates is an effective strategy for design of highly cyclable, thermally stable, and energy-dense solar thermal fuels.

  13. Evaluation of diurnal thermal energy storage combined with cogeneration systems

    Energy Technology Data Exchange (ETDEWEB)

    Somasundaram, S.; Brown, D.R.; Drost, M.K.

    1992-11-01

    This report describes the results of an evaluation of thermal energy storage (TES) integrated with simple gas turbine cogeneration systems. The TES system captures and stores thermal energy from the gas turbine exhaust for immediate or future generation of process heat. Integrating thermal energy storage with conventional cogeneration equipment increases the initial cost of the combined system; but, by decoupling electric power and process heat production, the system offers the following two significant advantages: (1) Electric power can be generated on demand, irrespective of the process heat load profile, thus increasing the value of the power produced; (2) Although supplementary firing could be used to serve independently varying electric and process heat loads, this approach is inefficient. Integrating TES with cogeneration can serve the two independent loads while firing all fuel in the gas turbine. The study evaluated the cost of power produced by cogeneration and cogeneration/TES systems designed to serve a fixed process steam load. The value of the process steam was set at the levelized cost estimated for the steam from a conventional stand-alone boiler. Power costs for combustion turbine and combined-cycle power plants were also calculated for comparison. The results indicated that peak power production costs for the cogeneration/TES systems were between 25% and 40% lower than peak power costs estimated for a combustion turbine and between 15% and 35% lower than peak power costs estimated for a combined-cycle plant. The ranges reflect differences in the daily power production schedule and process steam pressure/temperature assumptions for the cases evaluated. Further cost reductions may result from optimization of current cogeneration/TES system designs and improvement in TES technology through future research and development.

  14. Evaluation of diurnal thermal energy storage combined with cogeneration systems

    Science.gov (United States)

    Somasundaram, S.; Brown, D. R.; Drost, M. K.

    1992-11-01

    This report describes the results of an evaluation of thermal energy storage (TES) integrated with simple gas turbine cogeneration systems. The TES system captures and stores thermal energy from the gas turbine exhaust for immediate or future generation of process heat. Integrating thermal energy storage with conventional cogeneration equipment increases the initial cost of the combined system; but, by decoupling electric power and process heat production, the system offers the following significant advantages: (1) electric power can be generated on demand, irrespective of the process heat load profile, thus increasing the value of the power produced; (2) although supplementary firing could be used to serve independently varying electric and process heat loads, this approach is inefficient. Integrating TES with cogeneration can serve the two independent loads while firing all fuel in the gas turbine. The study evaluated the cost of power produced by cogeneration and cogeneration/TES systems designed to serve a fixed process steam load. The value of the process steam was set at the levelized cost estimated for the steam from a conventional stand-alone boiler. Power costs for combustion turbine and combined-cycle power plants were also calculated for comparison. The results indicated that peak power production costs for the cogeneration/TES systems were between 25 and 40 percent lower than peak power costs estimated for a combustion turbine and between 15 and 35 percent lower than peak power costs estimated for a combined-cycle plant. The ranges reflect differences in the daily power production schedule and process steam pressure/temperature assumptions for the cases evaluated. Further cost reductions may result from optimization of current cogeneration/TES system designs and improvement in TES technology through future research and development.

  15. Technical and economic feasibility of thermal energy storage. Thermal energy storage application to the brick/ceramic industry. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Glenn, D.R.

    1976-10-01

    An initial project to study the technical and economic feasibility of thermal energy storage (TES) in the three major consumer markets, namely, the residential, commercial and industrial sectors is described. A major objective of the study was to identify viable TES applications from which a more concise study could be launched, leading to a conceptual design and in-depth validation of the TES energy impacts. This report documents one such program. The brick/ceramic industries commonly use periodic kilns which by their operating cycle require time-variant energy supply and consequently variable heat rejection. This application was one of the numerous TES opportunities that emerged from the first study, now available from the ERDA Technical Information Center, Oak Ridge, Tennessee, identified as Report No. COO-2558-1.

  16. Thermal energy storage using chloride salts and their eutectics

    International Nuclear Information System (INIS)

    Myers, Philip D.; Goswami, D. Yogi

    2016-01-01

    Achieving the goals of the U.S. Department of Energy (DOE) Sunshot initiative requires (1) higher operating temperatures for concentrating solar power (CSP) plants to increase theoretical efficiency, and (2) effective thermal energy storage (TES) strategies to ensure dispatchability. Current inorganic salt-based TES systems in large-scale CSP plants generally employ molten nitrate salts for energy storage, but nitrate salts are limited in application to lower temperatures—generally, below 600 °C. These materials are sufficient for parabolic trough power plants, but they are inadequate for use at higher temperatures. At the higher operating temperatures achievable in solar power tower-type CSP plants, chloride salts are promising candidates for application as TES materials, owing to their thermal stability and generally lower cost compared to nitrate salts. In light of this, a recent study was conducted, which included a preliminary survey of chloride salts and binary eutectic systems that show promise as high temperature TES media. This study provided some basic information about the salts, including phase equilibria data and estimates of latent heat of fusion for some of the eutectics. Cost estimates were obtained through a review of bulk pricing for the pure salts among various vendors. This review paper updates that prior study, adding data for additional salt eutectic systems obtained from the literature. Where possible, data are obtained from the thermodynamic database software, FactSage. Radiative properties are presented, as well, since at higher temperatures, thermal radiation becomes a significant mode of heat transfer. Material compatibility for inorganic salts is another important consideration (e.g., with regard to piping and/or containment), so a summary of corrosion studies with various materials is also presented. Lastly, cost data for these systems are presented, allowing for meaningful comparison among these systems and other materials for TES

  17. Promotion of solar thermal energy - guide and comparison of experience

    Energy Technology Data Exchange (ETDEWEB)

    Ballot, E. [ALTER Alsace (France)

    2004-01-01

    One of the objectives of the guide is to analyse the methods of the various partners of the project (Germany, Cyprus, Town of Barcelona and France) and to make a list with the most important ones, which could eventually be reproduced and adapted in other regions. Also, try to find out the problems that the various partners encounter (lack of information, technical and financial tools...), look for the best ways for developing the solar thermal energy and try to find out some answers from the stake holders of this domain and from our partners. (author)

  18. Bibliography of the seasonal thermal energy storage library

    Energy Technology Data Exchange (ETDEWEB)

    Prater, L.S.; Casper, G.; Kawin, R.A.

    1981-08-01

    The Main Listing is arranged alphabetically by the last name of the first author. Each citation includes the author's name, title, publisher, publication date, and where applicable, the National Technical Information Service (NTIS) number or other document number. The number preceding each citation is the identification number for that document in the Seasonal Thermal Energy Storage (STES) Library. Occasionally, one or two alphabetic characters are added to the identification number. These alphabetic characters indicate that the document is contained in a collection of papers, such as the proceedings of a conference. An Author Index and an Identification Number Index are included. (WHK)

  19. Solar-thermal-energy collection/storage-pond system

    Science.gov (United States)

    Blahnik, D.E.

    1982-03-25

    A solar thermal energy collection and storage system is disclosed. Water is contained, and the water surface is exposed directly to the sun. The central part of an impermeable membrane is positioned below the water's surface and above its bottom with a first side of the membrane pointing generally upward in its central portion. The perimeter part of the membrane is placed to create a watertight boundary separating the water into a first volume which is directly exposable to the sun and which touches the membranes first side, and a second volumn which touches the membranes second side. A salt is dissolved in the first water volume.

  20. Analysis of dynamic effects in solar thermal energy conversion systems

    Science.gov (United States)

    Hamilton, C. L.

    1978-01-01

    The paper examines a study the purpose of which is to assess the performance of solar thermal power systems insofar as it depends on the dynamic character of system components and the solar radiation which drives them. Using a dynamic model, the daily operation of two conceptual solar conversion systems was simulated under varying operating strategies and several different time-dependent radiation intensity functions. These curves ranged from smoothly varying input of several magnitudes to input of constant total energy whose intensity oscillated with periods from 1/4 hour to 6 hours.

  1. Electrochemical energy storage systems for solar thermal applications

    Science.gov (United States)

    Krauthamer, S.; Frank, H.

    1980-01-01

    Existing and advanced electrochemical storage and inversion/conversion systems that may be used with terrestrial solar-thermal power systems are evaluated. The status, cost and performance of existing storage systems are assessed, and the cost, performance, and availability of advanced systems are projected. A prime consideration is the cost of delivered energy from plants utilizing electrochemical storage. Results indicate that the five most attractive electrochemical storage systems are the: iron-chromium redox (NASA LeRC), zinc-bromine (Exxon), sodium-sulfur (Ford), sodium-sulfur (Dow), and zinc-chlorine (EDA).

  2. Pore structure modified diatomite-supported PEG composites for thermal energy storage.

    Science.gov (United States)

    Qian, Tingting; Li, Jinhong; Deng, Yong

    2016-09-01

    A series of novel composite phase change materials (PCMs) were tailored by blending PEG and five kinds of diatomite via a vacuum impregnation method. To enlarge its pore size and specific surface area, different modification approaches including calcination, acid treatment, alkali leaching and nano-silica decoration on the microstructure of diatomite were outlined. Among them, 8 min of 5 wt% NaOH dissolution at 70 °C has been proven to be the most effective and facile. While PEG melted during phase transformation, the maximum load of PEG could reach 70 wt.%, which was 46% higher than that of the raw diatomite. The apparent activation energy of PEG in the composite was 1031.85 kJ·mol(-1), which was twice higher than that of the pristine PEG. Moreover, using the nano-silica decorated diatomite as carrier, the maximum PEG load was 66 wt%. The composite PCM was stable in terms of thermal and chemical manners even after 200 cycles of melting and freezing. All results indicated that the obtained composite PCMs were promising candidate materials for building applications due to its large latent heat, suitable phase change temperature, excellent chemical compatibility, improved supercooling extent, high thermal stability and long-term reliability.

  3. Pore structure modified diatomite-supported PEG composites for thermal energy storage

    Science.gov (United States)

    Qian, Tingting; Li, Jinhong; Deng, Yong

    2016-09-01

    A series of novel composite phase change materials (PCMs) were tailored by blending PEG and five kinds of diatomite via a vacuum impregnation method. To enlarge its pore size and specific surface area, different modification approaches including calcination, acid treatment, alkali leaching and nano-silica decoration on the microstructure of diatomite were outlined. Among them, 8 min of 5 wt% NaOH dissolution at 70 °C has been proven to be the most effective and facile. While PEG melted during phase transformation, the maximum load of PEG could reach 70 wt.%, which was 46% higher than that of the raw diatomite. The apparent activation energy of PEG in the composite was 1031.85 kJ·mol-1, which was twice higher than that of the pristine PEG. Moreover, using the nano-silica decorated diatomite as carrier, the maximum PEG load was 66 wt%. The composite PCM was stable in terms of thermal and chemical manners even after 200 cycles of melting and freezing. All results indicated that the obtained composite PCMs were promising candidate materials for building applications due to its large latent heat, suitable phase change temperature, excellent chemical compatibility, improved supercooling extent, high thermal stability and long-term reliability.

  4. Mapping Thermal Energy Resource Potentials from Wastewater Treatment Plants

    Directory of Open Access Journals (Sweden)

    Georg Neugebauer

    2015-09-01

    Full Text Available Wastewater heat recovery via heat exchangers and heat pumps constitutes an environmentally friendly, approved and economically competitive, but often underestimated technology. By introducing the spatial dimension in feasibility studies, the results of calculations change considerably. This paper presents a methodology to estimate thermal energy resource potentials of wastewater treatment plants taking spatial contexts into account. In close proximity to settlement areas, wastewater energy can ideally be applied for heating in mixed-function areas, which very likely have a continuous heat demand and allow for an increased amount of full-load hours compared to most single-use areas. For the Austrian case, it is demonstrated that the proposed methodology leads to feasible results and that the suggested technology might reduce up to 17% of the Austrian global warming potential of room heating. The method is transferrable to other countries as the input data and calculation formula are made available. A broad application of wastewater energy with regard to spatial structures and spatial development potentials can lead to (1 increasing energy efficiency by using a maximum of waste heat and (2 a significant reduction of (fossil energy consumption which results in a considerable reduction of the global warming potential of the heat supply (GWP if electricity from renewables is used for the operation of heat pumps.

  5. A novel application of concentrated solar thermal energy in foundries.

    Science.gov (United States)

    Selvaraj, J; Harikesavan, V; Eshwanth, A

    2016-05-01

    Scrap preheating in foundries is a technology that saves melting energy, leading to economic and environmental benefits. The proposed method in this paper utilizes solar thermal energy for preheating scrap, effected through a parabolic trough concentrator that focuses sunlight onto a receiver which carries the metallic scrap. Scraps of various thicknesses were placed on the receiver to study the heat absorption by them. Experimental results revealed the pattern with which heat is gained by the scrap, the efficiency of the process and how it is affected as the scrap gains heat. The inferences from them gave practical guidelines on handling scraps for best possible energy savings. Based on the experiments conducted, preheat of up to 160 °C and a maximum efficiency of 70 % and a minimum efficiency of 40 % could be achieved across the time elapsed and heat gained by the scrap. Calculations show that this technology has the potential to save around 8 % of the energy consumption in foundries. Cumulative benefits are very encouraging: 180.45 million kWh of energy savings and 203,905 t of carbon emissions cut per year across the globe. This research reveals immense scope for this technology to be adopted by foundries throughout the world.

  6. Current and future competitiveness of renewable energy carriers - Conceptions about competitiveness; Foernyelsebara energibaerares nuvarande och framtida konkurrenskraft - foerestaellningar om konkurrenskraft

    Energy Technology Data Exchange (ETDEWEB)

    Lundgren, K.

    1998-05-01

    The dissertation draws attention to the fact that in the world today 80% of the resources that are used are limited - non renewable energy carriers - and because of the long time between planning and doing (carrying out) within the energy sector, it is worthwhile from the long-term perspective to steer early on towards more sustainable solutions, such as renewable energy carriers. The State and the market have begun to adjust to concepts such as `competitiveness`, which can be viewed as containing both feasibility and legitimacy aspects - the state through different regulations and environmental taxes and environmental fees, and actors on the market that marginally produce/choose renewable energy carriers. The overlying methodology in the dissertation is an actor`s viewpoint. This viewpoint brings forth, in turn, two different views, the analytical and the interpretative. The dissertation presents different stances within the energy sector: commercial production logic, commercial sustainability logic, and the socio-economic sustainability logic. By drawing one`s attention to how one has the possibility to create (enact) his own reality, it is possible to highlight how organisations can increase their competitiveness by being conscious of their own view and others, logic, which in turn forms their views about competitiveness, which in turn determines which projects will materialize. Enterprises and individuals create a description of reality together through a dialectic process, i.e. by developing an environmental management system that contains elements of environmental auditing, environmental performance indicators, and environmental labelling, which `reveal` the production conditions that lie behind the actualization of the final product. An example is the product, `green` electricity, which, in spite of the fact that the final product - electricity - is identical irrespective of the production method, just at the moment can be sold at different prices according

  7. High efficiency thermal energy storage system for utility applications

    International Nuclear Information System (INIS)

    Vrable, D.L.; Quade, R.N.

    1979-01-01

    A concept of coupling a high efficiency base loaded coal or nuclear power plant with a thermal energy storage scheme for efficient and low-cost intermediate and peaking power is presented. A portion of the power plant's thermal output is used directly to generate superheated steam for continuous operation of a conventional turbine-generator to product base-load power. The remaining thermal output is used on a continuous basis to heat a conventional heat transfer salt (such as the eutectic composition of KaNO 3 /NaNO 3 /NaNO 2 ), which is stored in a high-temperature reservoir [538 0 C (1000 0 F)]. During peak demand periods, the salt is circulated from the high-temperature reservoir to a low-temperature reservoir through steam generators in order to provide peaking power from a conventional steam cycle plant. The period of operation can vary, but may typically be the equivalent of about 4 to 8 full-power hours each day. The system can be tailored to meet the utilities' load demand by varying the base-load level and the period of operation of the peak-load system

  8. Thermal energy storage for cooling of commercial buildings

    Energy Technology Data Exchange (ETDEWEB)

    Akbari, H. (Lawrence Berkeley Lab., CA (USA)); Mertol, A. (Science Applications International Corp., Los Altos, CA (USA))

    1988-07-01

    The storage of coolness'' has been in use in limited applications for more than a half century. Recently, because of high electricity costs during utilities' peak power periods, thermal storage for cooling has become a prime target for load management strategies. Systems with cool storage shift all or part of the electricity requirement from peak to off-peak hours to take advantage of reduced demand charges and/or off-peak rates. Thermal storage technology applies equally to industrial, commercial, and residential sectors. In the industrial sector, because of the lack of economic incentives and the custom design required for each application, the penetration of this technology has been limited to a few industries. The penetration rate in the residential sector has been also very limited due to the absence of economic incentives, sizing problems, and the lack of compact packaged systems. To date, the most promising applications of these systems, therefore, appear to be for commercial cooling. In this report, the current and potential use of thermal energy storage systems for cooling commercial buildings is investigated. In addition, a general overview of the technology is presented and the applicability and cost-effectiveness of this technology for developed and developing countries are discussed. 28 refs., 12 figs., 1 tab.

  9. Emissions, energy return and economics from utilizing forest residues for thermal energy compared to onsite pile burning

    Science.gov (United States)

    Greg Jones; Dan Loeffler; Edward Butler; Woodam Chung; Susan Hummel

    2010-01-01

    The emissions from delivering and burning forest treatment residue biomass in a boiler for thermal energy were compared with onsite disposal by pile-burning and using fossil fuels for the equivalent energy. Using biomass for thermal energy reduced carbon dioxide emissions on average by 39 percent and particulate matter emissions by 89 percent for boilers with emission...

  10. Thermal energy storage for the Stirling engine powered automobile

    Science.gov (United States)

    Morgan, D. T. (Editor)

    1979-01-01

    A thermal energy storage (TES) system developed for use with the Stirling engine as an automotive power system has gravimetric and volumetric storage densities which are competitive with electric battery storage systems, meets all operational requirements for a practical vehicle, and can be packaged in compact sized automobiles with minimum impact on passenger and freight volume. The TES/Stirling system is the only storage approach for direct use of combustion heat from fuel sources not suitable for direct transport and use on the vehicle. The particular concept described is also useful for a dual mode TES/liquid fuel system in which the TES (recharged from an external energy source) is used for short duration trips (approximately 10 miles or less) and liquid fuel carried on board the vehicle used for long duration trips. The dual mode approach offers the potential of 50 percent savings in the consumption of premium liquid fuels for automotive propulsion in the United States.

  11. Dish concentrators for solar thermal energy - Status and technology development

    Science.gov (United States)

    Jaffe, L. D.

    1981-01-01

    Comparisons are presented of point-focusing, or 'dish' solar concentrator system features, development status, and performance levels demonstrated to date. In addition to the requirements of good optical efficiency and high geometric concentration ratios, the most important future consideration in solar thermal energy dish concentrator design will be the reduction of installed and lifetime costs, as well as the materials and labor costs of production. It is determined that technology development initiatives are needed in such areas as optical materials, design wind speeds and wind loads, structural configuration and materials resistance to prolonged exposure, and the maintenance of optical surfaces. The testing of complete concentrator systems, with energy-converting receivers and controls, is also necessary. Both reflector and Fresnel lens concentrator systems are considered.

  12. Thermal energy storage for a space solar dynamic power system

    Science.gov (United States)

    Faget, N. M.; Fraser, W. M., Jr.; Simon, W. E.

    1985-01-01

    In the past, NASA has employed solar photovoltaic devices for long-duration missions. Thus, the Skylab system has operated with a silicon photovoltaic array and a nickel-cadmium electrochemical system energy storage system. Difficulties regarding the employment of such a system for the larger power requirements of the Space Station are related to a low orbit system efficiency and the large weight of the battery. For this reason the employment of a solar dynamic power system (SDPS) has been considered. The primary components of an SDPS include a concentrating mirror, a heat receiver, a thermal energy storage (TES) system, a thermodynamic heat engine, an alternator, and a heat rejection system. The heat-engine types under consideration are a Brayton cycle engine, an organic Rankine cycle engine, and a free-piston/linear-alternator Stirling cycle engine. Attention is given to a system description, TES integration concepts, and a TES technology assessment.

  13. A THERMAL-HYDRAULIC SYSTEM FOR THE CONVERSION AND THE STORAGE OF ENERGY

    OpenAIRE

    MITRAN Tudor; CHIOREANU Nicolae; ABAITANCAI Horia; RUS Alexandru

    2016-01-01

    The paper proposes the concept design of a thermal-hydraulic system that converts the thermal energy (from the geothermal water, from the cooling water of power equipment, from exhaust gasses, and so.) in hydrostatic energy, that is stored in a hydraulic accumulator. The hydraulic energy can be converted into electrical energy when needed.

  14. A THERMAL-HYDRAULIC SYSTEM FOR THE CONVERSION AND THE STORAGE OF ENERGY

    Directory of Open Access Journals (Sweden)

    MITRAN Tudor

    2016-05-01

    Full Text Available The paper proposes the concept design of a thermal-hydraulic system that converts the thermal energy (from the geothermal water, from the cooling water of power equipment, from exhaust gasses, and so. in hydrostatic energy, that is stored in a hydraulic accumulator. The hydraulic energy can be converted into electrical energy when needed.

  15. 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.

  16. Efficient Solar-Thermal Energy Harvest Driven by Interfacial Plasmonic Heating-Assisted Evaporation.

    Science.gov (United States)

    Chang, Chao; Yang, Chao; Liu, Yanming; Tao, Peng; Song, Chengyi; Shang, Wen; Wu, Jianbo; Deng, Tao

    2016-09-07

    The plasmonic heating effect of noble nanoparticles has recently received tremendous attention for various important applications. Herein, we report the utilization of interfacial plasmonic heating-assisted evaporation for efficient and facile solar-thermal energy harvest. An airlaid paper-supported gold nanoparticle thin film was placed at the thermal energy conversion region within a sealed chamber to convert solar energy into thermal energy. The generated thermal energy instantly vaporizes the water underneath into hot vapors that quickly diffuse to the thermal energy release region of the chamber to condense into liquids and release the collected thermal energy. The condensed water automatically flows back to the thermal energy conversion region under the capillary force from the hydrophilic copper mesh. Such an approach simultaneously realizes efficient solar-to-thermal energy conversion and rapid transportation of converted thermal energy to target application terminals. Compared to conventional external photothermal conversion design, the solar-thermal harvesting device driven by the internal plasmonic heating effect has reduced the overall thermal resistance by more than 50% and has demonstrated more than 25% improvement of solar water heating efficiency.

  17. Molten salt thermal energy storage systems: salt selection

    Energy Technology Data Exchange (ETDEWEB)

    Maru, H.C.; Dullea, J.F.; Huang, V.S.

    1976-08-01

    A research program aimed at the development of a molten salt thermal energy storage system commenced in June 1976. This topical report describes Work performed under Task I: Salt Selection is described. A total of 31 inorganic salts and salt mixtures, including 9 alkali and alkaline earth carbonate mixtures, were evaluated for their suitability as heat-of-fusion thermal energy storage materials at temperatures of 850 to 1000/sup 0/F. Thermophysical properties, safety hazards, corrosion, and cost of these salts were compared on a common basis. We concluded that because alkali carbonate mixtures show high thermal conductivity, low volumetric expansion on melting, low corrosivity and good stability, they are attractive as heat-of-fusion storage materials in this temperature range. A 35 wt percent Li/sub 2/CO/sub 3/-65 wt percent K/sub 2/CO/sub 3/ (50 mole percent Li/sub 2/CO/sub 3/-50 mole percent K/sub 2/CO/sub 3/) mixture was selected as a model system for further experimental work. This is a eutectoid mixture having a heat of fusion of 148 Btu/lb (82 cal/g) that forms an equimolar compound, LiKCO/sub 3/. The Li/sub 2/CO/sub 3/-K/sub 2/CO/sub 3/ mixture is intended to serve as a model system to define heat transfer characteristics, potential problems, and to provide ''first-cut'' engineering data required for the prototype system. The cost of a thermal energy storage system containing this mixture cannot be predicted until system characteristics are better defined. However, our comparison of different salts indicated that alkali and alkaline earth chlorides may be more attractive from a salt cost point of view. The long-term corrosion characteristics and the effects of volume change on melting for the chlorides should be investigated to determine their overall suitability as a heat-of-fusion storage medium.

  18. Simulation of diurnal thermal energy storage systems: Preliminary results

    Science.gov (United States)

    Katipamula, S.; Somasundaram, S.; Williams, H. R.

    1994-12-01

    This report describes the results of a simulation of thermal energy storage (TES) integrated with a simple-cycle gas turbine cogeneration system. Integrating TES with cogeneration can serve the electrical and thermal loads independently while firing all fuel in the gas turbine. The detailed engineering and economic feasibility of diurnal TES systems integrated with cogeneration systems has been described in two previous PNL reports. The objective of this study was to lay the ground work for optimization of the TES system designs using a simulation tool called TRNSYS (TRaNsient SYstem Simulation). TRNSYS is a transient simulation program with a sequential-modular structure developed at the Solar Energy Laboratory, University of Wisconsin-Madison. The two TES systems selected for the base-case simulations were: (1) a one-tank storage model to represent the oil/rock TES system; and (2) a two-tank storage model to represent the molten nitrate salt TES system. Results of the study clearly indicate that an engineering optimization of the TES system using TRNSYS is possible. The one-tank stratified oil/rock storage model described here is a good starting point for parametric studies of a TES system. Further developments to the TRNSYS library of available models (economizer, evaporator, gas turbine, etc.) are recommended so that the phase-change processes is accurately treated.

  19. Utilizing Ocean Thermal Energy in a Submarine Robot

    Science.gov (United States)

    Jones, Jack; Chao, Yi

    2009-01-01

    A proposed system would exploit the ocean thermal gradient for recharging the batteries in a battery-powered unmanned underwater vehicle [UUV (essentially, a small exploratory submarine robot)] of a type that has been deployed in large numbers in research pertaining to global warming. A UUV of this type travels between the ocean surface and depths, measuring temperature and salinity. The proposed system is related to, but not the same as, previously reported ocean thermal energy conversion (OTEC) systems that exploit the ocean thermal gradient but consist of stationary apparatuses that span large depth ranges. The system would include a turbine driven by working fluid subjected to a thermodynamic cycle. CO2 has been provisionally chosen as the working fluid because it has the requisite physical properties for use in the range of temperatures expected to be encountered in operation, is not flammable, and is much less toxic than are many other commercially available refrigerant fluids. The system would be housed in a pressurized central compartment in a UUV equipped with a double hull (see figure). The thermodynamic cycle would begin when the UUV was at maximum depth, where some of the CO2 would condense and be stored, at relatively low temperature and pressure, in the annular volume between the inner and outer hulls. The cycle would resume once the UUV had ascended to near the surface, where the ocean temperature is typically greater than or equals 20 C. At this temperature, the CO2 previously stored at depth in the annular volume between the inner and outer hulls would be pressurized to approx. equals 57 bar (5.7 MPa). The pressurized gaseous CO2 would flow through a check valve into a bladder inside the pressurized compartment, thereby storing energy of the relatively warm, pressurized CO2 for subsequent use after the next descent to maximum depth.

  20. PHASE CHANGE MATERIALS IN FLOOR TILES FOR THERMAL ENERGY STORAGE

    Energy Technology Data Exchange (ETDEWEB)

    Douglas C. Hittle

    2002-10-01

    Passive solar systems integrated into residential structures significantly reduce heating energy consumption. Taking advantage of latent heat storage has further increased energy savings. This is accomplished by the incorporation of phase change materials into building materials used in passive applications. Trombe walls, ceilings and floors can all be enhanced with phase change materials. Increasing the thermal storage of floor tile by the addition of encapsulated paraffin wax is the proposed topic of research. Latent heat storage of a phase change material (PCM) is obtained during a change in phase. Typical materials use the latent heat released when the material changes from a liquid to a solid. Paraffin wax and salt hydrates are examples of such materials. Other PCMs that have been recently investigated undergo a phase transition from one solid form to another. During this process they will release heat. These are known as solid-state phase change materials. All have large latent heats, which makes them ideal for passive solar applications. Easy incorporation into various building materials is must for these materials. This proposal will address the advantages and disadvantages of using these materials in floor tile. Prototype tile will be made from a mixture of quartz, binder and phase change material. The thermal and structural properties of the prototype tiles will be tested fully. It is expected that with the addition of the phase change material the structural properties will be compromised to some extent. The ratio of phase change material in the tile will have to be varied to determine the best mixture to provide significant thermal storage, while maintaining structural properties that meet the industry standards for floor tile.

  1. Energy spectrum of carriers in Kaner-type semiconductors in magnetic field of constant direction with trigonometric depending variation perpendicular to the field

    International Nuclear Information System (INIS)

    Babanly, A.M.; Babanly, A.M.; Huner, V.

    2010-01-01

    It was presented compact analytical solutions for the energy spectrum and wave functions of carriers in two-dimensional Kaner-type semiconductors in a magnetic field of constant direction with trigonometric depending variation perpendicular to the field direction

  2. Technical and economic feasibility of thermal energy storage. Annual report

    Energy Technology Data Exchange (ETDEWEB)

    Glenn, D.R.

    1976-02-01

    This study provides a first-look at the system elements involved in: (1) creating a market; (2) understanding and deriving the requirements; (3) performing analytical effort; (4) specifying equipment; and (5) synthesizing applications for a thermal energy storage (TES) function. The work reviews implicated markets, energy consumption patterns, TES technologies, and applications. Further, several concepts are developed and evaluated in some detail. Key findings are: (1) there are numerous technical opportunities for TES in the residential and industrial market sectors; (2) apart from sensible heat storage and transfer, significant R and D is required to fully exploit the superior heat densities of latent heat-based TES systems, particularly at temperatures above 600/sup 0/F; (3) industrial energy conservation can be favorably impacted by TES where periodic or batch-operated unit functions characterize product manufacturing processes, i.e. bricks, steel, and ceramics; and (4) a severe data shortage exists for describing energy consumption rates in real time as related to plant process operations--a needed element in designing TES systems.

  3. Energy Consumption of Insulated Material Using Thermal Effect Analysis

    Directory of Open Access Journals (Sweden)

    Fadzil M. A.

    2017-01-01

    Full Text Available Wall is one of the structures elements that resist direct heat from the atmosphere. Modification on several structures is relevance to reduce filtrate thermal movement on wall. Insulation material seems to be suitable to be implemented since its purpose meets the heat resistance requirement. Insulation material applied as to generate positive impact in energy saving through reduction in total building energy consumption. Fiberglass is one of the insulation materials that can be used to insulate a space from heat and sound. Fiberglass is flammable insulation material with R Value rated of R-2.9 to R-3.8 which meets the requirement in minimizing heat transfer. Finite element software, ABAQUS v6.13 employed for analyze non insulated wall and other insulated wall with different wall thicknesses. The several calculations related to overall heat movement, total energy consumption per unit area of wall, life cycle cost analysis and determination of optimal insulation thickness is calculated due to show the potential of the implementation in minimize heat transfer and generate potential energy saving in building operation. It is hoped that the study can contribute to better understanding on the potential building wall retrofitting works in increasing building serviceability and creating potential benefits for building owner.

  4. Preparation and thermal energy storage properties of paraffin/calcined diatomite composites as form-stable phase change materials

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Zhiming [School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083 (China); Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane, Queensland 4001 (Australia); Zhang, Yuzhong [School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083 (China); Zheng, Shuilin, E-mail: shuilinzh@yahoo.com.cn [School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083 (China); Park, Yuri [Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane, Queensland 4001 (Australia); Frost, Ray L., E-mail: r.frost@qut.edu.au [Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane, Queensland 4001 (Australia)

    2013-04-20

    Highlights: ► Composite phase change material (PCM) was prepared by blending composite paraffin and calcined diatomite. ► The optimum mixed proportion was obtained through differential scanning calorimetry. ► Thermal energy storage properties of the composite PCMs were determined by DSC. ► Thermal cycling test showed that the prepared PCMs are thermally reliable and chemically stable. - Abstract: A composite paraffin-based phase change material (PCM) was prepared by blending composite paraffin and calcined diatomite through the fusion adsorption method. In this study, raw diatomite was purified by thermal treatment in order to improve the adsorption capacity of diatomite, which acted as a carrier material to prepare shape-stabilized PCMs. Two forms of paraffin (paraffin waxes and liquid paraffin) with different melting points were blended together by the fusion method, and the optimum mixed proportion with a suitable phase-transition temperature was obtained through differential scanning calorimetry (DSC) analysis. Then the prepared composite paraffin was adsorbed in calcined diatomite. The prepared paraffin/calcined diatomite composites were characterized by the scanning electron microscope (SEM) and Fourier transformation infrared (FT-IR) analysis techniques. Thermal energy storage properties of the composite PCMs were determined by DSC method. DSC results showed that there was an optimum adsorption ratio between composite paraffin and calcined diatomite and the phase-transition temperature and the latent heat of the composite PCMs were 33.04 °C and 89.54 J/g, respectively. Thermal cycling test of composite PCMs showed that the prepared material is thermally reliable and chemically stable. The obtained paraffin/calcined diatomite composites have proper latent heat and melting temperatures, and show practical significance and good potential application value.

  5. Preparation and thermal energy storage properties of paraffin/calcined diatomite composites as form-stable phase change materials

    International Nuclear Information System (INIS)

    Sun, Zhiming; Zhang, Yuzhong; Zheng, Shuilin; Park, Yuri; Frost, Ray L.

    2013-01-01

    Highlights: ► Composite phase change material (PCM) was prepared by blending composite paraffin and calcined diatomite. ► The optimum mixed proportion was obtained through differential scanning calorimetry. ► Thermal energy storage properties of the composite PCMs were determined by DSC. ► Thermal cycling test showed that the prepared PCMs are thermally reliable and chemically stable. - Abstract: A composite paraffin-based phase change material (PCM) was prepared by blending composite paraffin and calcined diatomite through the fusion adsorption method. In this study, raw diatomite was purified by thermal treatment in order to improve the adsorption capacity of diatomite, which acted as a carrier material to prepare shape-stabilized PCMs. Two forms of paraffin (paraffin waxes and liquid paraffin) with different melting points were blended together by the fusion method, and the optimum mixed proportion with a suitable phase-transition temperature was obtained through differential scanning calorimetry (DSC) analysis. Then the prepared composite paraffin was adsorbed in calcined diatomite. The prepared paraffin/calcined diatomite composites were characterized by the scanning electron microscope (SEM) and Fourier transformation infrared (FT-IR) analysis techniques. Thermal energy storage properties of the composite PCMs were determined by DSC method. DSC results showed that there was an optimum adsorption ratio between composite paraffin and calcined diatomite and the phase-transition temperature and the latent heat of the composite PCMs were 33.04 °C and 89.54 J/g, respectively. Thermal cycling test of composite PCMs showed that the prepared material is thermally reliable and chemically stable. The obtained paraffin/calcined diatomite composites have proper latent heat and melting temperatures, and show practical significance and good potential application value

  6. Review of simulation techniques for aquifer thermal energy storage (ATES)

    Energy Technology Data Exchange (ETDEWEB)

    Mercer, J.W.; Faust, C.R.; Miller, W.J.; Pearson, F.J. Jr.

    1981-03-01

    The storage of thermal energy in aquifers has recently received considerable attention as a means to conserve and more efficiently use energy supplies. The analysis of aquifer thermal energy storage (ATES) systems will rely on the results from mathematical and geochemical models. Therefore, the state-of-the-art models relevant to ATES was reviewed and evaluated. These models describe important processes active in ATES including ground-water flow, heat transport (heat flow), solute transport (movement of contaminants), and geochemical reactions. In general, available models of the saturated ground-water environment are adequate to address most concerns associated with ATES; that is, design, operation, and environmental assessment. In those cases where models are not adequate, development should be preceded by efforts to identify significant physical phenomena and relate model parameters to measurable quantities. Model development can then proceed with the expectation of an adequate data base existing for the model's eventual use. Review of model applications to ATES shows that the major emphasis has been on generic sensitivity analysis and site characterization. Assuming that models are applied appropriately, the primary limitation on model calculations is the data base used to construct the model. Numerical transport models are limited by the uncertainty of subsurface data and the lack of long-term historical data for calibration. Geochemical models are limited by the lack of thermodynamic data for the temperature ranges applicable to ATES. Model applications undertaken with data collection activities on ATES sites should provide the most important contributions to the understanding and utilization of ATES. Therefore, the primary conclusion of this review is that model application to field sites in conjunction with data collection activities is essential to the development of this technology.

  7. Technologies for power and thermal energy generation. Bring our energies together

    International Nuclear Information System (INIS)

    2014-05-01

    On behalf of ADEME, the DREAL and the Region of Brittany and produced by ENEA, consulting company in energy and sustainable development, this brochure presents main technologies for power and thermal energy generation in an effort to maintain objectivity (efficiency, intrinsic features of each technology and key figures as regards power and energy). If most of the technologies are operational or in development in Brittany, such as ocean energy, the scope has been extended to encompass all existing technologies in France in order to give useful references. The French Brittany is a peninsula, with regards to both its geographic situation and its energy context. The region has decided to investigate energy and climate issue through the Brittany Energy Conference and to commit for energy transition. Discussions which have taken place since 2010 at the regional level as well as the national debate on energy transition in 2013 have highlighted the need for educational tools for the main energy generation technologies. Thus, the purpose of this brochure is to share energy stakes with a broad audience

  8. Thermal Comfort Project: A Cool Solution to the Nation's Energy Security Challenges

    Energy Technology Data Exchange (ETDEWEB)

    2002-05-01

    This fact sheet describes how the CTTS thermal comfort project will increase energy security by reducing fuel consumed by auxiliary loads such as air conditioning. It also describes physiological and psychological computer models and thermal comfort manikin.

  9. Expected benefits of federally-funded thermal energy storage research

    Energy Technology Data Exchange (ETDEWEB)

    Spanner, G E; Daellenbach, K K; Hughes, K R; Brown, D R; Drost, M K

    1992-09-01

    Pacific Northwest Laboratory (PNL) conducted this study for the Office of Advanced Utility Concepts of the US Department of Energy (DOE). The objective of this study was to develop a series of graphs that depict the long-term benefits of continuing DOE's thermal energy storage (TES) research program in four sectors: building heating, building cooling, utility power production, and transportation. The study was conducted in three steps- The first step was to assess the maximum possible benefits technically achievable in each sector. In some sectors, the maximum benefit was determined by a supply side'' limitation, and in other sectors, the maximum benefit is determined by a demand side'' limitation. The second step was to apply economic cost and diffusion models to estimate the benefits that are likely to be achieved by TES under two scenarios: (1) with continuing DOE funding of TES research, and (2) without continued funding. The models all cover the 20-year period from 1990 to 2010. The third step was to prepare graphs that show the maximum technical benefits achievable, the estimated benefits with TES research funding, and the estimated benefits in the absence of TES research funding. The benefits of federally-funded TES research are largely in four areas: displacement of primary energy, displacement of oil and natural gas, reduction in peak electric loads, and emissions reductions.

  10. Expected benefits of federally-funded thermal energy storage research

    Energy Technology Data Exchange (ETDEWEB)

    Spanner, G.E.; Daellenbach, K.K.; Hughes, K.R.; Brown, D.R.; Drost, M.K.

    1992-09-01

    Pacific Northwest Laboratory (PNL) conducted this study for the Office of Advanced Utility Concepts of the US Department of Energy (DOE). The objective of this study was to develop a series of graphs that depict the long-term benefits of continuing DOE`s thermal energy storage (TES) research program in four sectors: building heating, building cooling, utility power production, and transportation. The study was conducted in three steps- The first step was to assess the maximum possible benefits technically achievable in each sector. In some sectors, the maximum benefit was determined by a ``supply side`` limitation, and in other sectors, the maximum benefit is determined by a ``demand side`` limitation. The second step was to apply economic cost and diffusion models to estimate the benefits that are likely to be achieved by TES under two scenarios: (1) with continuing DOE funding of TES research, and (2) without continued funding. The models all cover the 20-year period from 1990 to 2010. The third step was to prepare graphs that show the maximum technical benefits achievable, the estimated benefits with TES research funding, and the estimated benefits in the absence of TES research funding. The benefits of federally-funded TES research are largely in four areas: displacement of primary energy, displacement of oil and natural gas, reduction in peak electric loads, and emissions reductions.

  11. Characterizing the thermal effects of High Energy Arc Faults

    Energy Technology Data Exchange (ETDEWEB)

    Putorti, Anthony; Bareham, Scott; Praydis, Joseph Jr. [National Institute of Standards and Technology (NIST), Gaithersburg, MD (United States); Melly, Nicholas B. [U.S. Nuclear Regulatory Commission (NRC), Washington, DC (United States)

    2015-12-15

    International and domestic operating experience involving High Energy Arc Faults (HEAF) in Nuclear Power Plant (NPP) electrical power systems have demonstrated the potential to cause extensive damage to electrical components and distribution systems along with damage to adjacent equipment and cables. An international study by the Committee on the Safety of Nuclear Installations (CSNI) gOECD Fire Project. Topical Report No. 1: Analysis of High Energy Arcing Fault (HEAF) Fire Events h published June 25, 2013 [1], illustrates that HEAF events have the potential to be major risk contributors with significant safety consequences and substantial economic loss. In an effort to better understand and characterize the threats posed by HEAF related phenomena, an international project has been chartered; the Joint Analysis of Arc Faults (Joan of ARC) OECD International Testing Program for High Energy Arc Faults. One of the major challenges of this research is how to properly measure and characterize the risk and influence of these events. Methods are being developed to characterize relevant parameters such as; temperature, heat flux, and heat release rate of fires resulting from HEAF events. Full scale experiments are being performed at low (≤ 1000 V) and medium (≤ 35 kV) voltages in electrical components. This paper introduces the methods being developed to measure thermal effects and discusses preliminary results of full scale HEAF experiments.

  12. Thermal energy storage systems using fluidized bed heat exchangers

    Science.gov (United States)

    Weast, T.; Shannon, L.

    1980-06-01

    A rotary cement kiln and an electric arc furnace were chosen for evaluation to determine the applicability of a fluid bed heat exchanger (FBHX) for thermal energy storage (TES). Multistage shallow bed FBHX's operating with high temperature differences were identified as the most suitable for TES applications. Analysis of the two selected conceptual systems included establishing a plant process flow configuration, an operational scenario, a preliminary FBHX/TES design, and parametric analysis. A computer model was developed to determine the effects of the number of stages, gas temperatures, gas flows, bed materials, charge and discharge time, and parasitic power required for operation. The maximum national energy conservation potential of the cement plant application with TES is 15.4 million barrels of oil or 3.9 million tons of coal per year. For the electric arc furnance application the maximum national conservation potential with TES is 4.5 million barrels of oil or 1.1 million tons of coal per year. Present time of day utility rates are near the breakeven point required for the TES system. Escalation of on-peak energy due to critical fuel shortages could make the FBHX/TES applications economically attractive in the future.

  13. Thermal energy storage systems using fluidized bed heat exchangers

    Science.gov (United States)

    Weast, T.; Shannon, L.

    1980-01-01

    A rotary cement kiln and an electric arc furnace were chosen for evaluation to determine the applicability of a fluid bed heat exchanger (FBHX) for thermal energy storage (TES). Multistage shallow bed FBHX's operating with high temperature differences were identified as the most suitable for TES applications. Analysis of the two selected conceptual systems included establishing a plant process flow configuration, an operational scenario, a preliminary FBHX/TES design, and parametric analysis. A computer model was developed to determine the effects of the number of stages, gas temperatures, gas flows, bed materials, charge and discharge time, and parasitic power required for operation. The maximum national energy conservation potential of the cement plant application with TES is 15.4 million barrels of oil or 3.9 million tons of coal per year. For the electric arc furnance application the maximum national conservation potential with TES is 4.5 million barrels of oil or 1.1 million tons of coal per year. Present time of day utility rates are near the breakeven point required for the TES system. Escalation of on-peak energy due to critical fuel shortages could make the FBHX/TES applications economically attractive in the future.

  14. Aquifer thermal energy storage costs with a seasonal chill source

    Energy Technology Data Exchange (ETDEWEB)

    Brown, D.R.

    1983-01-01

    The cost of energy supplied by an aquifer thermal energy storage (ATES) system from a seasonal chill source was investigated. Costs were estimated for point demand and residential development ATES systems using the computer code AQUASTOR. AQUASTOR was developed at PNL specifically for the economic analysis of ATES systems. In this analysis the cost effect of varying a wide range of technical and economic parameters was examined. Those parameters exhibiting a substantial influence on the costs of ATES delivered chill were: system size; well flow rate; transmission distance; source temperature; well depth; and cost of capital. The effects of each parameter are discussed. Two primary constraints of ATES chill systems are the extremely low energy density of the storage fluid and the prohibitive costs of lengthy pipelines for delivering chill to residential users. This economic analysis concludes that ATES-delivered chill will not be competitive for residential cooling applications. The otherwise marginal attractiveness of ATES chill systems vanishes under the extremely low load factors characteristic of residential cooling systems. (LCL)

  15. Effect of carbon nanospheres on shape stabilization and thermal behavior of phase change materials for thermal energy storage

    International Nuclear Information System (INIS)

    Mehrali, Mohammad; Tahan Latibari, Sara; Mehrali, Mehdi; Mahlia, Teuku Meurah Indra; Cornelis Metselaar, Hendrik Simon

    2014-01-01

    Highlights: • Introducing novel form-stable PCM of stearic acid (SA)/carbon nanospheres (CNSs). • The highest stabilized SA content is 83 wt% in the SA/CNS composites. • Increasing thermal conductivity of composite phase change material with high amount of latent heat. - Abstract: Stearic acid (SA) is one of the main phase change materials (PCMs) for medium temperature thermal energy storage systems. In order to stabilize the shape and enhance the thermal conductivity of SA, the effects of adding carbon nanospheres (CNSs) as a carbon nanofiller were examined experimentally. The maximum mass fraction of SA retained in CNSs was found as 80 wt% without the leakage of SA in a melted state, even when it was heated over the melting point of SA. The dropping point test shows that there was clearly no liquid leakage through the phase change process at the operating temperature range of the composite PCMs. The thermal stability and thermal properties of composite PCMs were investigated with a thermogravimetric analyzer (TGA) and differential scanning calorimeter (DSC), respectively. The thermal conductivity of the SA/CNS composite was determined by the laser flash method. The thermal conductivity at 35 °C increased about 105% for the highest loading of CNS (50 wt%). The thermal cycling test proved that form-stable composite PCMs had good thermal reliability and chemical durability after 1000 cycles of melting and freezing, which is advantageous for latent heat thermal energy storage (LHTES)

  16. Exergy and energy analyses of two different types of PCM based thermal management systems for space air conditioning applications

    International Nuclear Information System (INIS)

    Tyagi, V.V.; Pandey, A.K.; Buddhi, D.; Tyagi, S.K.

    2013-01-01

    Highlights: ► Calcium chloride hexahydrate (CaCl 2 ⋅6H 2 O) as a PCM was used in this study. ► Two different capsulated system (HDPE based panel and balls) were designed. ► The results of CaCl 2 ⋅6H 2 O are very attractive for space air conditioning. ► Energy and exergy analyses for space cooling applications. - Abstract: This communication presents the experimental study of PCM based thermal management systems for space heating and cooling applications using energy and exergy analysis. Two different types of based thermal management system (TMS-I and TMS-II) using calcium chloride hexahydrate as the heat carrier has been designed, fabricated and studied for space heating and cooling applications at a typical climatic zone in India. In the first experimental arrangement the charging of PCM has been carried out with air conditioning system while discharging has been carried out using electric heater for both the thermal management systems. While in the second arrangement the charging of PCM has been carried out by solar energy and the discharging has been carried out by circulating the cooler ambient air during the night time. In the first experiment, TMS-I is found to be more effective than that of TMS-II while it was found to be reverse in the case of second experiment for both the charging and discharging processes not only for energetic but also for the exergetic performances

  17. Ocean Thermal Energy Conversion Using Double-Stage Rankine Cycle

    Directory of Open Access Journals (Sweden)

    Yasuyuki Ikegami

    2018-03-01

    Full Text Available Ocean Thermal Energy Conversion (OTEC using non-azeotropic mixtures such as ammonia/water as working fluid and the multistage cycle has been investigated in order to improve the thermal efficiency of the cycle because of small ocean temperature differences. The performance and effectiveness of the multistage cycle are barely understood. In addition, previous evaluation methods of heat exchange process cannot clearly indicate the influence of the thermophysical characteristics of the working fluid on the power output. Consequently, this study investigated the influence of reduction of the irreversible losses in the heat exchange process on the system performance in double-stage Rankine cycle using pure working fluid. Single Rankine, double-stage Rankine and Kalina cycles were analyzed to ascertain the system characteristics. The simple evaluation method of the temperature difference between the working fluid and the seawater is applied to this analysis. From the results of the parametric performance analysis it can be considered that double-stage Rankine cycle using pure working fluid can reduce the irreversible losses in the heat exchange process as with the Kalina cycle using an ammonia/water mixture. Considering the maximum power efficiency obtained in the study, double-stage Rankine and Kalina cycles can improve the power output by reducing the irreversible losses in the cycle.

  18. Strategies for commercializing customer thermal-energy storage. [64 references

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, S.H.

    1976-12-01

    This report presents strategies for commercializing customer thermal storage. Four storage techniques are evaluated: space heating, air conditioning, hot-water heating, and interruptible hot-water heating. The storage systems involved store off-peak electric energy for thermal applications during peak load hours. Analyses of both storage techniques and principal parties affected by storage indicate four barriers: the absence of (1) commercially available air conditioning storage devices, (2) appropriate rates, (3) information on both rates and devices, and (4) widespread utility support. Development of appropriate rates is the key to commercialization. The criteria used to evaluate rate types are: maximum combined utility and customer benefits, ease of commercialization, and practical feasibility. Four rate types--demand charges, time-of-use rates, and two forms of load management rates (a monthly credit and an off-peak discount)--plus the possibility of utility ownership are considered. The best rate types for each storage option are: for hot-water heating, a monthly credit for allowing utility interruptions or an off-peak price discount for storage; for space heating, an off-peak discount contingent upon meeting utility requirements; and for air conditioning, an off-peak discount plus monthly credit.

  19. Extended development of a sodium hydroxide thermal energy storage module

    Science.gov (United States)

    Rice, R. E.; Rowny, P. E.; Cohen, B. M.

    1980-09-01

    The post-test evaluation of a single heat exchanger sodium hydroxide thermal energy storage module for use in solar electric generation is reported. Chemical analyses of the storage medium used in the experimental model are presented. The experimental verification of the module performance using an alternate heat transfer fluid, Caloria HT-43, is described. Based on these results, a design analysis of a dual heat exchanger concept within the storage module is presented. A computer model and a reference design for the dual system (storage working fluid/power cycle working fluid) were completed. The dual system is estimated to have a capital cost of approximately one half that of the single heat exchanger concept.

  20. Thermal Properties of Cement-Based Composites for Geothermal Energy Applications.

    Science.gov (United States)

    Bao, Xiaohua; Memon, Shazim Ali; Yang, Haibin; Dong, Zhijun; Cui, Hongzhi

    2017-04-27

    Geothermal energy piles are a quite recent renewable energy technique where geothermal energy in the foundation of a building is used to transport and store geothermal energy. In this paper, a structural-functional integrated cement-based composite, which can be used for energy piles, was developed using expanded graphite and graphite nanoplatelet-based composite phase change materials (CPCMs). Its mechanical properties, thermal-regulatory performance, and heat of hydration were evaluated. Test results showed that the compressive strength of GNP-Paraffin cement-based composites at 28 days was more than 25 MPa. The flexural strength and density of thermal energy storage cement paste composite decreased with increases in the percentage of CPCM in the cement paste. The infrared thermal image analysis results showed superior thermal control capability of cement based materials with CPCMs. Hence, the carbon-based CPCMs are promising thermal energy storage materials and can be used to improve the durability of energy piles.

  1. Optimization and spatial pattern of large-scale aquifer thermal energy storage

    NARCIS (Netherlands)

    Sommer, W.T.; Valstar, J.; Leusbrock, I.; Grotenhuis, J.T.C.; Rijnaarts, H.H.M.

    2015-01-01

    Aquifer thermal energy storage (ATES) is a cost-effective technology that enables the reduction of energy use and CO2 emissions associated with the heating and cooling of buildings by storage and recovery of large quantities of thermal energy in the subsurface. Reducing the distance between wells in

  2. Full-energy-chain analysis of greenhouse gas emissions for solar thermal electric power generation systems

    International Nuclear Information System (INIS)

    Norton, B.; Lawson, W.R.

    1997-01-01

    Technical attributes and environmental impacts of solar thermal options for centralized electricity generation are discussed. In particular, the full-energy-chain, including embodied energy and energy production, is considered in relation to greenhouse gas emission arising from solar thermal electricity generation. Central receiver, parabolic dish, parabolic trough and solar pond systems are considered. (author)

  3. Evaluation of thermal energy storage materials for advanced compressed air energy storage systems

    Energy Technology Data Exchange (ETDEWEB)

    Zaloudek, F.R.; Wheeler, K.R.; Marksberry, L.

    1983-03-01

    Advanced Compressed-Air Energy Storage (ACAS) plants have the near-term potential to reduce the fuel consumption of compressed-air plants from 33 to 100%, depending upon their design. Fuel is saved by storing some or all of the heat of compression as sensible heat which is subsequently used to reheat the compressed air prior to expansion in the turbine generator. The thermal storage media required for this application must be low cost and durable. The objective of this project was to screen thermal store materials based on their thermal cycle durability, particulate formation and corrosion resistant characteristics. The materials investigated were iron oxide pellets, Denstone pebbles, cast-iron balls, and Dresser basalt rock. The study specifically addressed the problems of particle formation and thermal ratcheting of the materials during thermal cycling and the chemical attack on the materials by the high temperature and moist environment in an ACAS heat storage bed. The results indicate that from the durability standpoint Denstone, cast iron containing 27% or more chromium, and crushed Dresser basalt would possibly stand up to ACAS conditions. If costs are considered in addition to durability and performance, the crushed Dresser basalt would probably be the most desirable heat storage material for adiabatic and hybrid ACAS plants, and more in-depth longer term thermal cycling and materials testing of Dresser basalt is recommended. Also recommended is the redesign and costing analysis of both the hybrid and adiabatic ACAS facilities based upon the use of Dresser basalt as the thermal store material.

  4. Influence of nanomaterials on properties of latent heat solar thermal energy storage materials – A review

    International Nuclear Information System (INIS)

    Raam Dheep, G.; Sreekumar, A.

    2014-01-01

    Highlights: • Classification of phase change materials. • Studies on phase change properties of various phase change materials. • Influence of nanomaterials on properties of phase change materials. - Abstract: Thermal energy storage system plays a critical role in developing an efficient solar energy device. As far as solar thermal devices are concerned, there is always a mismatch between supply and demand due to intermittent and unpredictable nature of solar radiation. A well designed thermal energy storage system is capable to alleviate this demerit by providing a constant energy delivery to the load. Many research works is being carried out to determine the suitability of thermal energy storage system to integrate with solar thermal gadgets. This review paper summarizes the numerous investigations on latent heat thermal energy storage using phase change materials (PCM) and its classification, properties, selection criteria, potential research areas and studies involved to analyze the thermal–physical properties of PCM

  5. Thermal energy storage characteristics of bentonite-based composite PCMs with enhanced thermal conductivity as novel thermal storage building materials

    International Nuclear Information System (INIS)

    Sarı, Ahmet

    2016-01-01

    Graphical abstract: In this work, novel bentonite-based and form-stable composite phase change materials (Bb-FSPCMs) were produced for LHTES in buildings by impregnation of CA, PEG600, DD and HD with bentonite clay. The microstructures of the compatibility of the Bb-FSPCMs were by using SEM and FT-IR techniques. The DSC results indicated that the produced Bb-FSPCMs composites had suitable phase change temperature of 4–30 °C and good latent heat capacity between 38 and 74 J/g. The TG results demonstrated that all of the fabricated Bb-FSPCMs had good thermal resistance. The Bb-FSPCMs maintained their LHTES properties even after 1000 heating–cooling cycling. The total heating times of the prepared Bb-FSPCMs were reduced noticeably due to their enhanced thermal conductivity after EG (5 wt%) addition. - Highlights: • Bb-FSPCMs were produced by impregnation of CA, PEG600, DD and HD with bentonite. • DSC analysis indicated that Bb-FSPCMs had melting temperature in range of 4–30 °C. • DSC analysis also showed that Bb-FSPCMs had latent heat between 38 and 74 J/g. • The TG analysis demonstrated that Bb-FSPCMs had good thermal resistance. • Thermal conductivity of Bb-FSPCMs were enhanced noticeably with EG (5 wt%) addition. - Abstract: In this work, for latent heat thermal energy storage (LHTES) applications in buildings, bentonite-based form-stable composite phase change materials (Bb-FSPCMs) were produced by impregnation of capric acid (CA), polyethylene glycol (PEG600), dodecanol (DD) and heptadecane (HD) into bentonite clay. The morphological characterization results obtained by scanning electron microscopy (SEM) showed that the bentonite acted as good structural barrier for the organic PCMs homogenously dispersed onto its surface and interlayers. The chemical investigations made by using fourier transform infrared (FT-IR) technique revealed that the attractions between the components of the composites was physical in nature and thus the PCMs were hold

  6. Renewable energy distributed power system with photovoltaic/ thermal and bio gas power generators

    International Nuclear Information System (INIS)

    Haider, M.U.; Rehman, S.U.

    2011-01-01

    The energy shortage and environmental pollution is becoming an important problem in these days. Hence it is very much important to use renewable power technologies to get rid of these problems. The important renewable energy sources are Bio-Energy, Wind Energy, Hydrogen Energy, Tide Energy, Terrestrial Heat Energy, Solar Energy, Thermal Energy and so on. Pakistan is rich in all these aspects particularly in Solar and Thermal Energies. In major areas of Pakistan like in South Punjab, Sind and Baluchistan the weather condition are very friendly for these types of Renewable Energies. In these areas Solar Energy can be utilized by solar panels in conjunction with thermal panels. The Photovoltaic cells are used to convert Solar Energy directly to Electrical Energy and thermal panels can be uses to convert solar energy into heat energy and this heat energy will be used to drive some turbine to get Electrical Energy. The Solar Energy can be absorbed more efficiently by any given area of Solar Panel if these two technologies can be combined in such a way that they can work together. The first part of this paper shows that how these technologies can be combined. Furthermore it is known to all that photovoltaic/thermal panels depend entirely on weather conditions. So in order to maintain constant power a biogas generator is used in conjunction with these. (author)

  7. Assessing District Energy Systems Performance Integrated with Multiple Thermal Energy Storages

    Science.gov (United States)

    Rezaie, Behnaz

    The goal of this study is to examine various energy resources in district energy (DE) systems and then DE system performance development by means of multiple thermal energy storages (TES) application. This study sheds light on areas not yet investigated precisely in detail. Throughout the research, major components of the heat plant, energy suppliers of the DE systems, and TES characteristics are separately examined; integration of various configurations of the multiple TESs in the DE system is then analysed. In the first part of the study, various sources of energy are compared, in a consistent manner, financially and environmentally. The TES performance is then assessed from various aspects. Then, TES(s) and DE systems with several sources of energy are integrated, and are investigated as a heat process centre. The most efficient configurations of the multiple TESs integrated with the DE system are investigated. Some of the findings of this study are applied on an actual DE system. The outcomes of this study provide insight for researchers and engineers who work in this field, as well as policy makers and project managers who are decision-makers. The accomplishments of the study are original developments TESs and DE systems. As an original development the Enviro-Economic Function, to balance the economic and environmental aspects of energy resources technologies in DE systems, is developed; various configurations of multiple TESs, including series, parallel, and general grid, are developed. The developed related functions are discharge temperature and energy of the TES, and energy and exergy efficiencies of the TES. The TES charging and discharging behavior of TES instantaneously is also investigated to obtain the charging temperature, the maximum charging temperature, the charging energy flow, maximum heat flow capacity, the discharging temperature, the minimum charging temperature, the discharging energy flow, the maximum heat flow capacity, and performance

  8. Energy Supply In A Building Via A Photovoltaic-Thermal Power System

    Directory of Open Access Journals (Sweden)

    Saban Yilmaz

    2015-04-01

    Full Text Available Abstract The fact that a PV-thermal energy system can supply energy for hot water and heating in a building is of vital importance for the proliferation of renewable energy sources. Central heating boilers are used in case of insufficient solar energy. This study mainly focuses on the planning of a PV-thermal power system for optimal energy supply in a building and a simulated performance analysis.

  9. Determination of the transport of thermal energy by conduction in perfused tissue

    International Nuclear Information System (INIS)

    Waterman, F.M.; Tupchong, L.; Matthews, J.; Nerlinger, R.E.

    1987-01-01

    A limitation of the thermal clearance method for determination of the blood flow rate during local hyperthermia is its inability to distinguish between thermal energy transport by perfusion and thermal conduction. A method is described for determination of the thermal energy transport by conduction at the point where thermal clearance is measured. Three profiles of the tissue temperature are measured in mutually orthogonal directions about this point. The conduction term of the bioheat equation is evaluated from the temperature profiles by the method of finite differences. The ability to determine the rate of thermal energy transport by conduction from orthogonal temperature profiles is demonstrated in a static phantom where conduction is the only mode of thermal energy transport. The implementation of this method in the clinic is described

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  11. Worker health and safety in solar thermal power systems. III. Thermal energy storage subsystems

    Energy Technology Data Exchange (ETDEWEB)

    Ullman, A.Z.; Sokolow, B.B.; Daniels, J.; Hurt, P.

    1979-10-01

    The effects of the use of thermal energy storage (TES) subsystems in solar thermal power systems (STPS) on operating failures and on worker health and safety are examined. Revelant near- and medium-term designs for TES subsystems are reviewed. Generic failure events are considered by an event tree methodology. Three generic categories of initiating events are identified which can lead to release of storage fluids and other hazards. Three TES subsystem designs are selected for, and subjected to, analysis. A fluid release event tree for a sensible heat TES subsystem using mixed media organic oil/crushed rock and sand, designed for the Barstow, CA, 10 MWe pilot plant, is developed. Toxicology and flammability hazards are considered. The effect of component failures, including ullage and fluid maintenance units, on subsystem safety is considered. A latent heat subsystem using NaNO/sub 3//NaOH as the working medium is studied, and relevant failure events delineated. Mechanical equipment failures including the scraped wall heat exchangers, are examined. Lastly, a thermochemical TES subsystem using SO/sub 2//SO/sub 3/ interconversion is considered. Principle hazards identified include mechanical failures and storage fluid release. The integrity of the system is found to depend on catalyst and heat exchanger reliability. Dynamic response to off-normal system events is considered.

  12. Characteristics of large thermal energy storage systems in Poland

    Directory of Open Access Journals (Sweden)

    Zwierzchowski Ryszard

    2017-01-01

    Full Text Available In District Heating Systems (DHS there are significant fluctuations in demand for heat by consumers during both the heating and the summer seasons. These variations are considered primarily in the 24-hour time horizon. These problems are aggravated further if the DHS is supplied by a CHP plant, because fluctuations in heat demand adversely affect to a significant degree the stable production of electricity at high overall efficiency. Therefore, introducing Thermal Energy Storage (TES would be highly recommended on these grounds alone. The characteristics of Large (i.e. over 10 000 m3 TES in operation in Poland are presented. Information is given regarding new projects (currently in design or construction that apply TES technology in DHS in Poland. The paper looks at the methodology used in Poland to select the TES system for a particular DHS, i.e., procedure for calculating capacity of the TES tank and the system to prevent water stored in the tank from absorbing oxygen from atmospheric air. Implementation of TES in DHS is treated as a recommended technology in the Polish District Heating sector. This technology offers great opportunities to improve the operating conditions of DHS, cutting energy production costs and emissions of pollutants to the atmosphere.

  13. Characteristics of large thermal energy storage systems in Poland

    Science.gov (United States)

    Zwierzchowski, Ryszard

    2017-11-01

    In District Heating Systems (DHS) there are significant fluctuations in demand for heat by consumers during both the heating and the summer seasons. These variations are considered primarily in the 24-hour time horizon. These problems are aggravated further if the DHS is supplied by a CHP plant, because fluctuations in heat demand adversely affect to a significant degree the stable production of electricity at high overall efficiency. Therefore, introducing Thermal Energy Storage (TES) would be highly recommended on these grounds alone. The characteristics of Large (i.e. over 10 000 m3) TES in operation in Poland are presented. Information is given regarding new projects (currently in design or construction) that apply TES technology in DHS in Poland. The paper looks at the methodology used in Poland to select the TES system for a particular DHS, i.e., procedure for calculating capacity of the TES tank and the system to prevent water stored in the tank from absorbing oxygen from atmospheric air. Implementation of TES in DHS is treated as a recommended technology in the Polish District Heating sector. This technology offers great opportunities to improve the operating conditions of DHS, cutting energy production costs and emissions of pollutants to the atmosphere.

  14. Design and installation manual for thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Cole, R L; Nield, K J; Rohde, R R; Wolosewicz, R M [eds.

    1979-02-01

    The purpose for this manual is to provide information on the design and installation of thermal energy storage in solar heating systems. It is intended for contractors, installers, solar system designers, engineers, architects, and manufacturers who intend to enter the solar energy business. The reader should have general knowledge of how solar heating systems operate and knowledge of construction methods and building codes. Knowledge of solar analysis methods such as f-chart, SOLCOST, DOE-1, or TRNSYS would be helpful. The information contained in the manual includes sizing storage, choosing a location for the storage device, and insulation requirements. Both air-based and liquid-based systems are covered with topics on designing rock beds, tank types, pump and fan selection, installation, costs, and operation and maintenance. Topics relevant to heating domestic water include safety, single- and dual-tank systems, domestic water heating with air- and liquid-based space heating system, and stand-alone domestic hot water systems. Several appendices present common problems with storage systems and their solutions, heat transfer fluid properties, heat exchanger sizing, and sample specifications for heat exchangers, wooden rock bins, steel tanks, concrete tanks, and fiberglass-reinforced plastic tanks.

  15. Design and installation manual for thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Cole, R L; Nield, K J; Rohde, R R; Wolosewicz, R M

    1980-01-01

    The purpose of this manual is to provide information on the design and installation of thermal energy storage in active solar systems. It is intended for contractors, installers, solar system designers, engineers, architects, and manufacturers who intend to enter the solar energy business. The reader should have general knowledge of how solar heating and cooling systems operate and knowledge of construction methods and building codes. Knowledge of solar analysis methods such as f-Chart, SOLCOST, DOE-1, or TRNSYS would be helpful. The information contained in the manual includes sizing storage, choosing a location for the storage device, and insulation requirements. Both air-based and liquid-based systems are covered with topics on designing rock beds, tank types, pump and fan selection, installation, costs, and operation and maintenance. Topics relevant to latent heat storage include properties of phase-change materials, sizing the storage unit, insulating the storage unit, available systems, and cost. Topics relevant to heating domestic water include safety, single- and dual-tank systems, domestic water heating with air- and liquid-based space heating systems, and stand alone domestics hot water systems. Several appendices present common problems with storage systems and their solutions, heat transfer fluid properties, economic insulation thickness, heat exchanger sizing, and sample specifications for heat exchangers, wooden rock bins, steel tanks, concrete tanks, and fiberglass-reinforced plastic tanks.

  16. Thermal stability and deactivation energy of free and immobilized invertase

    Directory of Open Access Journals (Sweden)

    F.J. Bassetti

    2000-12-01

    Full Text Available The thermal stability and the energy of deactivation of free invertase and the immobilized enzyme (IE was measured at temperatures in the range of 35 to 65°C for the hydrolysis of a 5% w/v sucrose solution. The free enzyme at pH 5.0 is stable up to 50°C for a period of 4 h. Invertase immobilized in controlled pore silica by the silane-glutaraldehyde covalent method is stable up to 55ºC, in pH 4.5 for the same period. For higher temperatures the enzyme deactivation follows the exponential decay model and half-lives are 0.53, 1.80, and 13.9 h for free invertase, at 65, 60, and 55ºC, respectively. For the IE half-lives are 0.48, 1.83, and 20.9 h, at 65, 60, and 55ºC, respectively. The IE is more stable than the free invertase; the energy of deactivation being 83.1 kcal/mol for the IE and 72.0 kcal/mol for the free enzyme.

  17. Intelligent trend analysis for a solar thermal energy collector field

    Science.gov (United States)

    Juuso, E. K.

    2018-03-01

    Solar thermal power plants collect available solar energy in a usable form at a temperature range which is adapted to the irradiation levels and seasonal variations. Solar energy can be collected only when the irradiation is high enough to produce the required temperatures. During the operation, a trade-off of the temperature and the flow is needed to achieve a good level for the collected power. The scaling approach brings temporal analysis to all measurements and features: trend indices are calculated by comparing the averages in the long and short time windows, a weighted sum of the trend index and its derivative detects the trend episodes and severity of the trend is estimated by including also the variable level in the sum. The trend index, trend episodes and especially, the deviation index reveal early evolving changes in the operating conditions, including cloudiness and load disturbances. The solution is highly compact: all variables, features and indices are transformed to the range [-2, 2] and represented in natural language which is important in integrating data-driven solutions with domain expertise. The special situations detected during the test campaigns are explained well.

  18. Improving Geothermal Heat Pump Air Conditioning Efficiency with Wintertime Cooling using Seasonal Thermal Energy Storage (STES). Application Manual

    Science.gov (United States)

    2016-11-01

    APPLICATION MANUAL Improving Geothermal Heat Pump Air Conditioning Efficiency with Wintertime Cooling using Seasonal Thermal Energy Storage...manual is to describe the use of the Seasonal Thermal Energy Storage (STES) technology, particularly through the employment of wintertime cooling...application projects to increase energy efficiency and occupant comfort. Seasonal Thermal Energy Storage (STES) technology, energy efficiency, geothermal heat

  19. How High Local Charge Carrier Mobility and an Energy Cascade in a Three-Phase Bulk Heterojunction Enable >90% Quantum Efficiency

    KAUST Repository

    Burke, Timothy M.

    2013-12-27

    Charge generation in champion organic solar cells is highly efficient in spite of low bulk charge-carrier mobilities and short geminate-pair lifetimes. In this work, kinetic Monte Carlo simulations are used to understand efficient charge generation in terms of experimentally measured high local charge-carrier mobilities and energy cascades due to molecular mixing. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Palmitic acid/polypyrrole composites as form-stable phase change materials for thermal energy storage

    International Nuclear Information System (INIS)

    Silakhori, Mahyar; Metselaar, Hendrik Simon Cornelis; Mahlia, Teuku Meurah Indra; Fauzi, Hadi; Baradaran, Saeid; Naghavi, Mohammad Sajad

    2014-01-01

    Highlights: • A novel phase change composite of palmitic acid–polypyrrole(PA–PPy) was fabricated. • Thermal properties of PA–PPy are characterized in different mass ratios of PA–PPy. • Thermal cycling test showed that form stable PCM had a favorable thermal reliability. - Abstract: In this study a novel palmitic acid (PA)/polypyrrole (PPy) form-stable PCMs were readily prepared by in situ polymerization method. PA was used as thermal energy storage material and PPy was operated as supporting material. Form-stable PCMs were investigated by SEM (scanning electron microscopy) and FTIR (Fourier transform infrared spectrometer) analysis that illustrated PA Particles were wrapped by PPy particles. XRD (X-ray diffractometer) was used for crystalline phase of PA/PPy composites. Thermogravimetry analysis (TGA) and differential scanning calorimetry (DSC) were used for investigating Thermal stability and thermal energy storage properties of prepared form-stable PCMs. According to the obtained results the form stable PCMs exhibited favorable thermal stability in terms of their phase change temperature. The form-stable PCMs (79.9 wt% loading of PA) were considered as the highest loading PCM with desirable latent heat storage of 166.3 J/g and good thermal stability. Accelerated thermal cycling tests also showed that form stable PCM had an acceptable thermal reliability. As a consequence of acceptable thermal properties, thermal stability and chemical stability, we can consider the new kind of form stable PCMs for low temperature solar thermal energy storage applications

  1. Energy demand and thermal comfort of HVAC systems with thermally activated building systems as a function of user profile

    Science.gov (United States)

    Pałaszyńska, Katarzyna; Bandurski, Karol; Porowski, Mieczysław

    2017-11-01

    Thermally Activated Building Systems (TABS) are a way to use building structure as a thermal energy storage. As a result, renewable energy sources may be used more efficiently. The paper presents numerical analysis of a HVAC system with TABS energy demand and indoor thermal comfort of a representative room in a non-residential building (governmental, commercial, educational). The purpose of analysis is to investigate the influence of a user profile on system performance. The time span of the analysis is one year - a typical meteorological year. The model was prepared using a generally accepted simulation tool - TRNSYS 17. The results help to better understand the interaction of a user profile with TABS. Therefore they are important for the development of optimal control algorithms for energy efficient buildings equipped with such systems.

  2. Chemically and Thermally Stable High Energy Density Silicone Composites, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Thermal energy storage systems with 300 -- 1000 kJ/kg energy density through either phase changes or chemical heat absorption are sought by NASA. This proposed...

  3. Thermal energy storage heat exchanger: Molten salt heat exchanger design for utility power plants

    Science.gov (United States)

    Ferarra, A.; Yenetchi, G.; Haslett, R.; Kosson, R.

    1977-01-01

    Sizing procedures are presented for latent heat thermal energy storage systems that can be used for electric utility off-peak energy storage, solar power plants and other preliminary design applications.

  4. What my dogs forced me to learn about thermal energy transfer

    Science.gov (United States)

    Bohren, Craig F.

    2015-05-01

    Some objects feel colder to the touch than others at the same (room) temperature. But explaining why by linear, single-factor reasoning is inadequate because the time-dependent thermal energy transfer at solid interfaces initially at different temperatures is determined by the thermal inertia √{ k ρ c } , a function of three thermophysical properties: thermal conductivity k, density ρ, and specific heat capacity per unit mass c. In time-dependent problems 1 / √{ k ρ c } plays the role of a resistance. As an example, although the thermal conductivity of aluminum is 16 times that of stainless steel, this does not translate into a 16-fold difference in interfacial thermal energy flux densities. Nor does it result in a markedly greater perceived coldness of aluminum; the difference is barely perceptible. Similarly, despite the 600-fold difference in the thermal conductivity of iron relative to that of wood, the ratio of thermal energy flux densities is only about 4.6.

  5. Enhancing Wind Power Integration through Optimal Use of Flexibility in Multi-Carrier Energy Systems from the Danish Perspective

    DEFF Research Database (Denmark)

    Zong, Yi; Awadelrahman, M. A. Ahmed; Wang, Jiawei

    2017-01-01

    heating systems are summarized in this paper. How to optimally use the cross-sectoral flexibility by intelligent control (model predictive control-based) of the key coupling components in an integrated heat and power system including electrical heat pumps in the demand side, and thermal storage......Denmark’ goal of being independent of fossil energy sources in 2050 puts forward great demands on all energy subsystems (electricity, heat, gas and transport, etc.) to be operated in a holistic manner. The Danish experience and challenges of wind power integration and the development of district...

  6. Dynamic tuning of optical absorbers for accelerated solar-thermal energy storage.

    Science.gov (United States)

    Wang, Zhongyong; Tong, Zhen; Ye, Qinxian; Hu, Hang; Nie, Xiao; Yan, Chen; Shang, Wen; Song, Chengyi; Wu, Jianbo; Wang, Jun; Bao, Hua; Tao, Peng; Deng, Tao

    2017-11-14

    Currently, solar-thermal energy storage within phase-change materials relies on adding high thermal-conductivity fillers to improve the thermal-diffusion-based charging rate, which often leads to limited enhancement of charging speed and sacrificed energy storage capacity. Here we report the exploration of a magnetically enhanced photon-transport-based charging approach, which enables the dynamic tuning of the distribution of optical absorbers dispersed within phase-change materials, to simultaneously achieve fast charging rates, large phase-change enthalpy, and high solar-thermal energy conversion efficiency. Compared with conventional thermal charging, the optical charging strategy improves the charging rate by more than 270% and triples the amount of overall stored thermal energy. This superior performance results from the distinct step-by-step photon-transport charging mechanism and the increased latent heat storage through magnetic manipulation of the dynamic distribution of optical absorbers.

  7. Reduction of thermal conductivity by low energy multi-Einstein optic modes

    Directory of Open Access Journals (Sweden)

    Huili Liu

    2016-06-01

    Full Text Available The lattice dynamics and thermal transport in Cu2-δSe compounds were investigated via theoretical calculations, neutron measurement, and characterization of thermal properties. The results show that binary ordered Cu2-δSe has an extremely low lattice thermal conductivity at low temperatures. The low energy multi-Einstein optic modes are the dominant approach obtaining such an extremely low lattice thermal conductivity. It is indicated that the damped vibrations of copper ions could contribute to the low energy multi-Einstein optic modes, especially for those low energy branches at 2–4 meV.

  8. Research and Development for Novel Thermal Energy Storage Systems (TES) for Concentrating Solar Power (CSP)

    Energy Technology Data Exchange (ETDEWEB)

    Faghri, Amir; Bergman, Theodore L; Pitchumani, Ranga

    2013-09-26

    The overall objective was to develop innovative heat transfer devices and methodologies for novel thermal energy storage systems for concentrating solar power generation involving phase change materials (PCMs). Specific objectives included embedding thermosyphons and/or heat pipes (TS/HPs) within appropriate phase change materials to significantly reduce thermal resistances within the thermal energy storage system of a large-scale concentrating solar power plant and, in turn, improve performance of the plant. Experimental, system level and detailed comprehensive modeling approaches were taken to investigate the effect of adding TS/HPs on the performance of latent heat thermal energy storage (LHTES) systems.

  9. Thermal to Electric Energy Conversion for Cyclic Heat Loads

    Science.gov (United States)

    Whitehead, Benjamin E.

    Today, we find cyclic heat loads almost everywhere. When we drive our cars, the engines heat up while we are driving and cool while parked. Processors heat while the computer is in use at the office and cool when idle at night. The sun heats the earth during the day and the earth radiates that heat into space at night. With modern technology, we have access to a number of methods to take that heat and convert it into electricity, but, before selecting one, we need to identify the parameters that inform decision making. The majority of the parameters for most systems include duty cycle, total cost, weight, size, thermal efficiency, and electrical efficiency. However, the importance of each of these will depend on the application. Size and weight take priority in a handheld device, while efficiency dominates in a power plant, and duty cycle is likely to dominate in highly demanding heat pump applications. Over the past decade, developments in semiconductor technology has led to the creation of the thermoelectric generator. With no moving parts and a nearly endlessly scalable nature, these generators present interesting opportunities for taking advantage of any source of waste heat. However, these generators are typically only capable of 5-8% efficiency from conversion of thermal to electric energy. [1]. Similarly, advancements in photovoltaic cells has led to the development of thermophotovoltaics. By heating an emitter to a temperature so it radiates light, a thermophotovoltaic cell then converts that light into electricity. By selecting materials that emit light in the optimal ranges of the appropriate photovoltaic cells, thermophotovoltaic systems can potentially exceed the current maximum of 10% efficiency. [2]. By pressurizing certain metal powders with hydrogen, hydrogen can be bound to the metal, creating a metal hydride, from which hydrogen can be later re-extracted under the correct pressure and temperature conditions. Since this hydriding reaction is

  10. Analysis of thermal energy storage for a pharmaceutical company

    Energy Technology Data Exchange (ETDEWEB)

    Henze, Gregor P. [Colorado Univ., Boulder, CO (US). Dept. of Civil, Environmental and Architectural Engineering (CEAE); Biffar, Bernd; Wienecke, Marcus [Boehringer Ingelheim Pharma GmbH und Co. KG, Biberach (Germany); Becker, Martin P. [Biberach Univ. of Applied Sciences (Germany). Dept. of Architectural and Energy Engineering

    2009-07-01

    A pharmaceutical facility located in Southern Germany is experiencing a trend of growing cooling loads to be met by the chilled water plant composed of ten chillers of greatly varying cost effectiveness. With a capacity shortfall inevitable, the question arises whether to install an additional chiller or improve the utilization of the existing chillers, in particular those with low operating costs per unit cooling, through the addition of a chilled water thermal energy storage (TES) system. To provide decision support in this matter, an optimization environment was developed and validated that adopts mixed integer programming as the approach to optimizing the chiller dispatch for any load condition, while an overarching dynamic programming based optimization approach optimizes the charge/discharge strategy of the TES system. In this fashion, the chilled water plant optimization is decoupled but embedded in the TES control optimization. The approach was selected to allow for arbitrary constraints and optimization horizons, while ensuring a global optimum to the problem. The results show that a relatively small TES tank provides significant economic and operational benefits. Yet, in order to facilitate long-term supply security, a larger TES tank capacity was decided on and the TES system was constructed in 2008. (orig.)

  11. Relationship of regional water quality to aquifer thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Allen, R.D.

    1983-11-01

    Ground-water quality and associated geologic characteristics may affect the feasibility of aquifer thermal energy storage (ATES) system development in any hydrologic region. This study sought to determine the relationship between ground-water quality parameters and the regional potential for ATES system development. Information was collected from available literature to identify chemical and physical mechanisms that could adversely affect an ATES system. Appropriate beneficiation techniques to counter these potential geochemical and lithologic problems were also identified through the literature search. Regional hydrology summaries and other sources were used in reviewing aquifers of 19 drainage regions in the US to determine generic geochemical characteristics for analysis. Numerical modeling techniques were used to perform geochemical analyses of water quality from 67 selected aquifers. Candidate water resources regions were then identified for exploration and development of ATES. This study identified six principal mechanisms by which ATES reservoir permeability may be impaired: (1) particulate plugging, (2) chemical precipitation, (3) liquid-solid reactions, (4) formation disaggregation, (5) oxidation reactions, and (6) biological activity. Specific proven countermeasures to reduce or eliminate these effects were found. Of the hydrologic regions reviewed, 10 were identified as having the characteristics necessary for ATES development: (1) Mid-Atlantic, (2) South-Atlantic Gulf, (3) Ohio, (4) Upper Mississippi, (5) Lower Mississippi, (6) Souris-Red-Rainy, (7) Missouri Basin, (8) Arkansas-White-Red, (9) Texas-Gulf, and (10) California.

  12. Ocean Thermal Energy Conversion (OTEC) Programmatic Environmental Analysis--Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Authors, Various

    1980-01-01

    The programmatic environmental analysis is an initial assessment of Ocean Thermal Energy Conversion (OTEC) technology considering development, demonstration and commercialization. It is concluded that the OTEC development program should continue because the development, demonstration, and commercialization on a single-plant deployment basis should not present significant environmental impacts. However, several areas within the OTEC program require further investigation in order to assess the potential for environmental impacts from OTEC operation, particularly in large-scale deployments and in defining alternatives to closed-cycle biofouling control: (1) Larger-scale deployments of OTEC clusters or parks require further investigations in order to assess optimal platform siting distances necessary to minimize adverse environmental impacts. (2) The deployment and operation of the preoperational platform (OTEC-1) and future demonstration platforms must be carefully monitored to refine environmental assessment predictions, and to provide design modifications which may mitigate or reduce environmental impacts for larger-scale operations. These platforms will provide a valuable opportunity to fully evaluate the intake and discharge configurations, biofouling control methods, and both short-term and long-term environmental effects associated with platform operations. (3) Successful development of OTEC technology to use the maximal resource capabilities and to minimize environmental effects will require a concerted environmental management program, encompassing many different disciplines and environmental specialties. This volume contains these appendices: Appendix A -- Deployment Scenario; Appendix B -- OTEC Regional Characterization; and Appendix C -- Impact and Related Calculations.

  13. Draft environmental assessment: Ocean Thermal Energy Conversion (OTEC) Pilot Plants

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, S.M.; Sands, M.D.; Donat, J.R.; Jepsen, P.; Smookler, M.; Villa, J.F.

    1981-02-01

    This Environmental Assessment (EA) has been prepared, in accordance with the National Environmental Policy Act of 1969, for the deployment and operation of a commercial 40-Megawatt (MW) Ocean Thermal Energy Conversion (OTEC) Pilot Plant (hereafter called the Pilot Plant). A description of the proposed action is presented, and a generic environment typical of the candidate Pilot Plant siting regions is described. An assessment of the potential environmental impacts associated with the proposed action is given, and the risk of credible accidents and mitigating measures to reduce these risks are considered. The Federal and State plans and policies the proposed action will encompass are described. Alternatives to the proposed action are presented. Appendix A presents the navigation and environmental information contained in the US Coast Pilot for each of the candidate sites; Appendix B provides a brief description of the methods and calculations used in the EA. It is concluded that environmental disturbances associated with Pilot Plant activities could potentially cause significant environmental impacts; however, the magnitude of these potential impacts cannot presently be assessed, due to insufficient engineering and environmental information. A site- and design-specific OTEC Pilot Plant Environmental Impact Statement (EIS) is required to resolve the potentially significant environmental effects associated with Pilot Plant deployment and operation. (WHK)

  14. Carrier Diagnosis

    Science.gov (United States)

    ... Inheritance of Hemophilia Definitions & Terminology Bleeding Symptoms Carrier Diagnosis When to Test for Carrier Status Family Planning and Pregnancy Conception Options Prenatal Diagnosis Fetal Sex ...

  15. Technical and economical studies on transport and storage of thermal energy as hot water

    International Nuclear Information System (INIS)

    Caizergues, R.

    1978-01-01

    The following are being studied: The conveyance of thermal energy as hot water (component parts of a distribution network, cost of thermie piped over long distances, optimization of ramified networks, ODYN Code) and the storage of thermal energy as hot water, (advantage of hot water storage systems, storage in porous environment, economics of storage system) [fr

  16. The effect of different transitional spaces on thermal comfort and energy consumption of residential buildings

    NARCIS (Netherlands)

    Taleghani, M.; Tenpierik, M.J.; Van den Dobbelsteen, A.A.J.F.

    2012-01-01

    Purpose- This paper focuses on the effect of courtyards, atria and sunspaces on indoor thermal comfort and energy consumption for heating and cooling. One of the most important purposes is to understand if certain transitional spaces can reduce the energy consumption of and improve thermal comfort

  17. IEA SHC Task 42 / ECES Annex 29 - Working Group B: Applications of Compact Thermal Energy Storage

    NARCIS (Netherlands)

    Helden, W. van; Yamaha, M.; Rathgeber, C.; Hauer, A.; Huaylla, F.; Le Pierrès, N.; Stutz, B.; Mette, B.; Dolado, P.; Lazaro, A.; Mazo, J.; Dannemand, M.; Furbo, S.; Campos-Celador, A.; Diarce, G.; Cuypers, R.; König-Haagen, A.; Höhlein, S.; Brüggemann, D.; Fumey, B.; Weber, R.; Köll, R.; Wagner, W.; Daguenet-Frick, X.; Gantenbein, P.; Kuznik, F.

    2016-01-01

    The IEA joint Task 42 / Annex 29 is aimed at developing compact thermal energy storage materials and systems. In Working Group B, experts are working on the development of compact thermal energy storage applications, in the areas cooling, domestic heating and hot water and industry. The majority of

  18. Sensitivity analysis of recovery efficiency in high-temperature aquifer thermal energy storage with single well

    DEFF Research Database (Denmark)

    Jeon, Jun-Seo; Lee, Seung-Rae; Pasquinelli, Lisa

    2015-01-01

    High-temperature aquifer thermal energy storage system usually shows higher performance than other borehole thermal energy storage systems. Although there is a limitation in the widespread use of the HT-ATES system because of several technical problems such as clogging, corrosion, etc., it is get...

  19. Thermoclines: a solar thermal energy resource for enhanced hydroelectric power production.

    Science.gov (United States)

    McNichols, J L; Ginell, W S; Cory, J S

    1979-01-12

    The solar thermal energy stored in hydroelectric reservoir thermoclines is very large and greatly exceeds the gravitational hydroenergy of the surface water, even after limitations arising from the second law of thermodynamics have been taken into account. Greatly enhanced power production can be obtained at present hydroelectric facilities if heat engines are adapted to exploit this large thermal energy resource.

  20. Preparation, thermal properties and thermal reliabilities of microencapsulated n-octadecane with acrylic-based polymer shells for thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Xiaolin [Advanced Materials Institute and Clearer Production Key Laboratory, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Key Laboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University, Haidian District, Beijing 100084 (China); Song, Guolin; Chu, Xiaodong; Li, Xuezhu [Advanced Materials Institute and Clearer Production Key Laboratory, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Tang, Guoyi, E-mail: tanggy@tsinghua.edu.cn [Advanced Materials Institute and Clearer Production Key Laboratory, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Key Laboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University, Haidian District, Beijing 100084 (China)

    2013-01-10

    Highlights: Black-Right-Pointing-Pointer n-Octadecane was encapsulated by p(butyl methacrylate) (PBMA) and p(butyl acrylate). Black-Right-Pointing-Pointer Microcapsules using divinylbenzene as crosslinking agent have better quality. Black-Right-Pointing-Pointer Microcapsule with butyl methacrylate-divinylbenzene has highest latent heat. Black-Right-Pointing-Pointer Microcapsule with butyl methacrylate-divinylbenzene has greatest thermal stability. Black-Right-Pointing-Pointer Phase change temperatures and enthalpies of the microcapsules varied little after thermal cycle. - Abstract: Microencapsulation of n-octadecane with crosslinked p(butyl methacrylate) (PBMA) and p(butyl acrylate) (PBA) as shells for thermal energy storage was carried out by a suspension-like polymerization. Divinylbenzene (DVB) and pentaerythritol triacrylate (PETA) were employed as crosslinking agents. The surface morphologies of the microencapsulated phase change materials (microPCMs) were studied by scanning electron microscopy (SEM). Thermal properties, thermal reliabilities and thermal stabilities of the as-prepared microPCMs were investigated by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The microPCMs prepared by using DVB exhibit greater heat capacities and higher thermal stabilities compared with those prepared by using PETA. The thermal resistant temperature of the microPCM with BMA-DVB polymer was up to 248 Degree-Sign C. The phase change temperatures and latent heats of all the as-prepared microcapsules varied little after 1000 thermal cycles.

  1. Preparation, thermal properties and thermal reliabilities of microencapsulated n-octadecane with acrylic-based polymer shells for thermal energy storage

    International Nuclear Information System (INIS)

    Qiu, Xiaolin; Song, Guolin; Chu, Xiaodong; Li, Xuezhu; Tang, Guoyi

    2013-01-01

    Highlights: ► n-Octadecane was encapsulated by p(butyl methacrylate) (PBMA) and p(butyl acrylate). ► Microcapsules using divinylbenzene as crosslinking agent have better quality. ► Microcapsule with butyl methacrylate–divinylbenzene has highest latent heat. ► Microcapsule with butyl methacrylate–divinylbenzene has greatest thermal stability. ► Phase change temperatures and enthalpies of the microcapsules varied little after thermal cycle. - Abstract: Microencapsulation of n-octadecane with crosslinked p(butyl methacrylate) (PBMA) and p(butyl acrylate) (PBA) as shells for thermal energy storage was carried out by a suspension-like polymerization. Divinylbenzene (DVB) and pentaerythritol triacrylate (PETA) were employed as crosslinking agents. The surface morphologies of the microencapsulated phase change materials (microPCMs) were studied by scanning electron microscopy (SEM). Thermal properties, thermal reliabilities and thermal stabilities of the as-prepared microPCMs were investigated by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The microPCMs prepared by using DVB exhibit greater heat capacities and higher thermal stabilities compared with those prepared by using PETA. The thermal resistant temperature of the microPCM with BMA–DVB polymer was up to 248 °C. The phase change temperatures and latent heats of all the as-prepared microcapsules varied little after 1000 thermal cycles.

  2. Indirect high-bandwidth stabilization of carrier-envelope phase of a high-energy, low-repetition-rate laser.

    Science.gov (United States)

    Fu, Yuxi; Takahashi, Eiji J; Midorikawa, Katsumi

    2016-06-13

    We demonstrate a method of stabilizing the carrier-envelope phase (CEP) of low-repetition-rate, high-energy femtosecond laser systems such as TW-PW class lasers. A relatively weak high-repetition-rate (~1 kHz) reference pulse copropagates with a low-repetition-rate (10 Hz) high-energy pulse, which are s- and p-polarized, respectively. Using a Brewster angle window, the reference pulse is separated after the power amplifier and used for feedback to stabilize its CEP. The single-shot CEP of the high-energy pulse is indirectly stabilized to 550 mrad RMS, which is the highest CEP stability ever reported for a low-repetition-rate (10-Hz) high-energy laser system. In this novel method, the feedback frequency of the reference pulse from the front-end preamplifier can be almost preserved. Thus, higher CEP stability can be realized than for lower frequencies. Of course, a reference pulse with an even higher repetition rate (e.g., 10 kHz) can be easily employed to sample and feed back CEP jitter over a broader frequency bandwidth.

  3. Thermal annealing effects on AlGaAsSb/GaSb laser structure: Bandgap energy blueshift and thermal conductivity enhancement

    Science.gov (United States)

    Ilahi, S.; Yacoubi, N.; Genty, F.

    2017-07-01

    In this paper, we have investigated the effects of thermal annealing on optical properties and thermal conductivity of AlGaAsSb/GaSb laser structure using photo-thermal deflection spectroscopy PDS. In fact, optical absorption spectrum and thermal conductivity have been determined by comparison between experimental and theoretical phase of PDS signal. We have found that band gap energy is blue shifted of 70 meV for the as grown to the sample annealed for 1 h. Indeed, the highest thermal conductivity is found around of 11 W/m.K for AlGaAsSb/GaSb annealed for 1 h, which presents a promising result for vertical-cavity surface-emitting lasers (VCSELs).

  4. The energy efficiency ratio of heat storage in one shell-and-one tube phase change thermal energy storage unit

    International Nuclear Information System (INIS)

    Wang, Wei-Wei; Wang, Liang-Bi; He, Ya-Ling

    2015-01-01

    Highlights: • A parameter to indicate the energy efficiency ratio of PCTES units is defined. • The characteristics of the energy efficiency ratio of PCTES units are reported. • A combined parameter of the physical properties of the working mediums is found. • Some implications of the energy efficiency ratio in design of PCTES units are analyzed. - Abstract: From aspect of energy consuming to pump heat transfer fluid, there is no sound basis on which to create an optimum design of a thermal energy storage unit. Thus, it is necessary to develop a parameter to indicate the energy efficiency of such unit. This paper firstly defines a parameter that indicates the ratio of heat storage of phase change thermal energy storage unit to energy consumed in pumping heat transfer fluid, which is called the energy efficiency ratio, then numerically investigates the characteristics of this parameter. The results show that the energy efficiency ratio can clearly indicate the energy efficiency of a phase change thermal energy storage unit. When the fluid flow of a heat transfer fluid is in a laminar state, the energy efficiency ratio is larger than in a turbulent state. The energy efficiency ratio of a shell-and-tube phase change thermal energy storage unit is more sensitive to the outer tube diameter. Under the same working conditions, within the heat transfer fluids studied, the heat storage property of the phase change thermal energy storage unit is best for water as heat transfer fluid. A combined parameter is found to indicate the effects of both the physical properties of phase change material and heat transfer fluid on the energy efficiency ratio

  5. Performance of modified greenhouse dryer with thermal energy storage

    Directory of Open Access Journals (Sweden)

    Om Prakash

    2016-11-01

    Full Text Available In this attempt, the main goal is to do annual performance, environomical analysis, energy analysis and exergy analysis of the modified greenhouse dryer (MGD operating under active mode (AM and passive mode (PM. Thermal storage is being applied on the ground of MGD. It is applied in three different ways namely barren floor, floor covered with black PVC sheet (PVC and Black Coated. Experimental study of dryers in no-load conditions reveals that floor covered with a black PVC sheet is more conducive for drying purpose than other floors. The MGD under AM is found to be more effective as compared to PM for tomato and capsicum, which are high moisture content crops. For medium moisture content crop (potato chips, both dryers show relatively similar drying performance. Crops dried inside the greenhouse dryer are found to be more nutrient than open sun dried crops. The payback period of the modified greenhouse dryer under passive mode is found to be 1.11 years. However, for the active mode of the modified greenhouse dryer is only 1.89 years. The embodied energy of the passive mode of the dryer is a 480.277 kWh and 628.73 kWh for the active mode of the dryer. The CO2 emissions per annum for passive and active mode greenhouse dryers are found to be 13.45 kg and 17.6 kg respectively. The energy payback time, carbon mitigation and carbon credit have been calculated based type of crop dried. The range of exergy efficiency is 29%–86% in MGD under PM and 30%–78% in the MGD under AM. The variation of Heat utilization factor (HUF for MGD under PM is 0.12–0.38 and 0.26–0.53 for MGD under AM. The range of co-efficient of performances (COP for MGD under PM is 0.55–0.87 and 0.58–0.73 for MGD under AM.

  6. Experimental investigation of the thermal and mechanical stability of rocks for high-temperature thermal-energy storage

    OpenAIRE

    Becattini, Viola; Motmans, Thomas; Zappone, Alba; Madonna, Claudio; Haselbacher, Andreas; Steinfeld, Aldo

    2017-01-01

    Six types of rocks of Alpine origin were investigated for their suitability for high-temperature packed-bed thermal-energy storage. The rocks were thermally cycled in laboratory furnaces between about 100 °C and 600°C with a heating rate of 2.6°C/min and assessed in terms of their specific heat capacity and porosity as well as the degree of cracking, fracturing, and disintegration. Thermal cycling was found to lead to decreases in the specific heat capacity and increases in the porosity of th...

  7. Recycled Thermal Energy from High Power Light Emitting Diode Light Source.

    Science.gov (United States)

    Ji, Jae-Hoon; Jo, GaeHun; Ha, Jae-Geun; Koo, Sang-Mo; Kamiko, Masao; Hong, JunHee; Koh, Jung-Hyuk

    2018-09-01

    In this research, the recycled electrical energy from wasted thermal energy in high power Light Emitting Diode (LED) system will be investigated. The luminous efficiency of lights has been improved in recent years by employing the high power LED system, therefore energy efficiency was improved compared with that of typical lighting sources. To increase energy efficiency of high power LED system further, wasted thermal energy should be re-considered. Therefore, wasted thermal energy was collected and re-used them as electrical energy. The increased electrical efficiency of high power LED devices was accomplished by considering the recycled heat energy, which is wasted thermal energy from the LED. In this work, increased electrical efficiency will be considered and investigated by employing the high power LED system, which has high thermal loss during the operating time. For this research, well designed thermoelement with heat radiation system was employed to enhance the collecting thermal energy from the LED system, and then convert it as recycled electrical energy.

  8. Integrated photovoltaic-thermal solar energy conversion systems

    Science.gov (United States)

    Samara, G. A.

    1975-01-01

    A combined photovoltaic/thermal collector has been built and is now being tested. Initial tests have concentrated on evaluating the thermal efficiency of the collector before and after the silicon cells are mounted. With likely improvements in bonding between cells and receiver and in the absorptivity of the cells, thermal efficiencies greater than 50% can be expected for the combined receiver operating at 100 C.

  9. A Wind Power Plant with Thermal Energy Storage for Improving the Utilization of Wind Energy

    Directory of Open Access Journals (Sweden)

    Chang Liu

    2017-12-01

    Full Text Available The development of the wind energy industry is seriously restricted by grid connection issues and wind energy generation rejections introduced by the intermittent nature of wind energy sources. As a solution of these problems, a wind power system integrating with a thermal energy storage (TES system for district heating (DH is designed to make best use of the wind power in the present work. The operation and control of the system are described in detail. A one-dimensional system model of the system is developed based on a generic model library using the object-oriented language Modelica for system modeling. Validations of the main components of the TES module are conducted against experimental results and indicate that the models can be used to simulate the operation of the system. The daily performance of the integrated system is analyzed based on a seven-day operation. And the influences of system configurations on the performance of the integrated system are analyzed. The numerical results show that the integrated system can effectively improve the utilization of total wind energy under great wind power rejection.

  10. Development of space heating and domestic hot water systems with compact thermal energy storage. Compact thermal energy storage: Material development for System Integration

    NARCIS (Netherlands)

    Davidson, J.H.; Quinnell, J.; Burch, J.; Zondag, H.A.; Boer, R. de; Finck, C.J.; Cuypers, R.; Cabeza, L.F.; Heinz, A.; Jahnig, D.; Furbo, S.; Bertsch, F.

    2013-01-01

    Long-term, compact thermal energy storage (TES) is essential to the development of cost-effective solar and passive building-integrated space heating systems and may enhance the annual technical and economic performance of solar domestic hot water (DHW) systems. Systems should provide high energy

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  12. Hydrogen as Future Energy Carrier: The ENEA Point of View on Technology and Application Prospects

    Directory of Open Access Journals (Sweden)

    Marina Ronchetti

    2009-03-01

    Full Text Available Hydrogen and fuel cells should reduce costs and increase reliability and durability to compete in the energy market. A considerable long term effort is necessary for research, development and demonstration of adequate solutions; important programs in this sense are carried out in the main industrialized countries, with the involvement of many industries, research structures and stakeholders. In such framework a relevant role is played in Italy by ENEA (Italian Agency for New Technologies, Energy and Environment. In the paper the main aspects related to the possible hydrogen role in the future society are addressed, according to ENEA perspectives.

  13. Investigating the potential of a novel low-energy house concept with hybrid adaptable thermal storage

    International Nuclear Information System (INIS)

    Hoes, P.; Trcka, M.; Hensen, J.L.M.; Hoekstra Bonnema, B.

    2011-01-01

    Research highlights: → In conventional buildings thermal mass is a permanent building characteristic. → Permanent thermal mass concepts are not optimal in all operational conditions. → We propose a concept that combines the benefits of low and high thermal mass. → Building simulation shows the concept is able to reduce the energy demand with 35%. → Furthermore, the concept increases the performance robustness of the building. -- Abstract: In conventional buildings thermal mass is a permanent building characteristic depending on the building design. However, none of the permanent thermal mass concepts are optimal in all operational conditions. We propose a concept that combines the benefits of buildings with low and high thermal mass by applying hybrid adaptable thermal storage (HATS) systems and materials to a lightweight building. The HATS concept increases building performance and the robustness to changing user behavior, seasonal variations and future climate changes. Building performance simulation is used to investigate the potential of the novel concept for reducing heating energy demand and increasing thermal comfort. Simulation results of a case study in the Netherlands show that the optimal quantity of the thermal mass is sensitive to the change of seasons. This implies that the building performance will benefit from implementing HATS. Furthermore, the potential of HATS is quantified using a simplified HATS model. Calculations show heating energy demand reductions of up to 35% and increased thermal comfort compared to conventional thermal mass concepts.

  14. A thermally self-sustained micro-power plant with integrated micro-solid oxide fuel cells, micro-reformer and functional micro-fluidic carrier

    NARCIS (Netherlands)

    Scherrer, B.; Evans, A.; Santis-Alvarez, A. J.; Jiang, B.; Martynczuk, J.; Galinski, H.; Nabavi, M.; Prestat, M.; Tölke, R.; Bieberle, A.; Poulikakos, D.; Muralt, P.; Niedermann, P.; Dommann, A.; Maeder, T.; Heeb, P.; Straessle, V.; Muller, C.; Gauckler, L. J.

    2014-01-01

    Low temperature micro-solid oxide fuel cell (micro-SOFC) systems are an attractive alternative power source for small-size portable electronic devices due to their high energy efficiency and density. Here, we report on a thermally self-sustainable reformer micro-SOFC assembly. The device consists of

  15. Study of thermally coupled distillation systems for energy-efficient ...

    Indian Academy of Sciences (India)

    but also helps reduce emissions associated with the use of the fossil fuels [2]. Thermally coupled distillation system. (TCDS) is one of such configurations. TCDS was first pro- posed by Wright [3] as a divided wall column and later the- oretical studies were performed by Petlyuk et al [4]. The fully thermally coupled distillation ...

  16. Energy transfer and thermal studies of Pr doped cerium oxalate ...

    Indian Academy of Sciences (India)

    Administrator

    transfer probabilities and thermal properties have been studied. Keywords. Optical materials; crystal growth; optical spectroscopy; thermal analysis. 1. Introduction. High quality, defect free crystals doped with trivalent lanthanides always attract attention of researchers because of their smart optical and spectroscopic proper-.

  17. Advanced Thermal Energy Conversion of Temperature under 300°C by Thermoelectric Conversion Method

    Science.gov (United States)

    Ueda, Tadashi; Uchida, Yoshiyuki; Shingu, Hiroyasu

    Many approaches have been developing for energy conversion throughout the world. However, it is difficult to achieve the global warming countermeasure based on “The Kyoto protocol”. Until now effective utilization of low temperature thermal energy (under 300°C) is not advancing one. For example, effective utilization method has not been established for waste heat energy which arise from industry machine tools, automobiles, internal combustion engines and thermal energy from natural environment, etc. In this paper, we reported the experiment for effective utilizing of low temperature (under 300°C) thermal energy conversion. The device used for the measurement is a copper thermo device. Thermo electromotive force of 150mW/cm2 was obtained at 200°C. The obtained thermo electromotive force is about 15 times higher in comparison with generally used alumal-chromal thermocouple. Our aim is that utilizes low temperature thermal energy effectively by converting into electricity.

  18. One-dimensional arrays of oscillators: Energy localization in thermal equilibrium

    International Nuclear Information System (INIS)

    Reigada, R.; Romero, A.H.; Sarmiento, A.; Lindenberg, K.

    1999-01-01

    All systems in thermal equilibrium exhibit a spatially variable energy landscape due to thermal fluctuations. Thus at any instant there is naturally a thermodynamically driven localization of energy in parts of the system relative to other parts of the system. The specific characteristics of the spatial landscape such as, for example, the energy variance, depend on the thermodynamic properties of the system and vary from one system to another. The temporal persistence of a given energy landscape, that is, the way in which energy fluctuations (high or low) decay toward the thermal mean, depends on the dynamical features of the system. We discuss the spatial and temporal characteristics of spontaneous energy localization in 1D anharmonic chains in thermal equilibrium. copyright 1999 American Institute of Physics

  19. Review of electrochemical energy conversion and storage for ocean thermal and wind energy systems

    Science.gov (United States)

    Landgrebe, A. R.; Donley, S. W.

    A literature review on electrochemical storage techniques related to ocean thermal (OTEC) and wind energy conversion systems (WECS) is presented. Battery use for WECS is foreseen because of siting size, variable capacity, quiet operation, and high efficiency; high cost and the necessity for further input voltage regulation is noted, as are prospects for technology transfer from existing programs for photovoltaic panel battery development. Fuel cells, which can run on hydrogen, ammonia, methanol, naphtha, etc., are encouraging because capacity increases are possible by simple addition of more fuel, and high thermal efficiency. Electrolytic use is seen as a cheap replacement source of electricity for metals refining and brine electrolysis. Systems of energy 'bridges' for OTEC plants, to transmit power to users, are reviewed as redox-flow, lithium-water-air, and aluminum batteries, fuel cells, electrolytic hydrogen, methane, and ammonia production, and the use of OTECs as power sources for floating factories. Directions of future research are indicated, noting that WECS will be in commercial production by 1985, while OTEC is far term, around 2025.

  20. Model-based predictive control applied to multi-carrier energy systems

    NARCIS (Netherlands)

    Arnold, M.; Negenborn, R.R.; Andersson, G.; De Schutter, B.

    2009-01-01

    The optimal operation of an integrated electricity and natural gas infrastructure is investigated. The couplings between the electricity system and the gas system are modeled by so-called energy hubs, which represent the interface between the loads on the one hand and the transmission

  1. Optimal Usage of Multiple Energy Carriers in Residential Systems : Unit Scheduling and Power Control

    NARCIS (Netherlands)

    Ramirez-Elizondo, L.M.

    2013-01-01

    The world’s increasing energy demand and growing environmental concerns have motivated scientists to develop new technologies and methods to make better use of the remaining resources of our planet. The main objective of this dissertation is to develop a scheduling and control tool at the district

  2. Wood as a raw commodity and energy carrier; Holz als Rohstoff und Energietraeger. Dynamisches Holzmarktmodell und Zukunftsszenarien - Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Pauli, B.; Buergi, P.; Bruehlhard, S. [Schweizerische Hochschule fuer Landwirtschaft, Zollikofen (Switzerland); Thees, O.; Lemm, R.; Rosset, Ch. [Eidg. Forschungsanstalt fuer Wald, Schnee und Landschaft, WSL, Birmensdorf (Switzerland)

    2010-05-15

    This comprehensive final report for the Swiss Federal Office of Energy (SFOE) takes a look at a dynamic wood-market model and the future prospects for the use of wood as a raw commodity and energy carrier. As an introduction, an overview of Swiss and international wood markets is provided. Various sorts of timber - from whole tree-trunks to waste wood for use as an energy source - are discussed. The international wood market is looked at and future developments are discussed. The report goes on to deal with four project stages which help provide an information basis in order to be able to review the current situation and the future developments in the Swiss wood industry. The first stage of the project involved the elaboration of a material-flow matrix for the year 2005. The sources of the data are discussed. Inconsistencies in the data are looked at and the Swiss wood market is analysed. This material-flow matrix provided the basis for a second step, the development of a product-oriented, dynamic wood market model. Here, all sources of wood from forests to waste wood are looked at and their use for building and as an energy resource is considered. Model development, variants and modelling factors are discussed. An expert-aided model is looked at. The market models developed were used for the third step, the development of scenarios for future development. Five scenarios were developed, including higher energy costs, a large, heavy storm event, increased per capita wood use, increasing global timber prices as well as the installation of a new, large-scale sawmill. In a final step, based on knowledge gained from the previous steps, suggestions for further action to be taken by politics were elaborated. Here, measures that would have an effect on supply and demand are suggested that could help decrease the costs for the harvesting of wood resources and support changes in the market behaviour of forest owners.

  3. Program definition and assessment overview. [for thermal energy storage project management

    Science.gov (United States)

    Gordon, L. H.

    1980-01-01

    The implementation of a program level assessment of thermal energy storage technology thrusts for the near and far term to assure overall coherent energy storage program is considered. The identification and definition of potential thermal energy storage applications, definition of technology requirements, and appropriate market sectors are discussed along with the necessary coordination, planning, and preparation associated with program reviews, workshops, multi-year plans and annual operating plans for the major laboratory tasks.

  4. Second national symposium `Thermal solar energy`; Zweites nationales Symposium Thermische Solarenergie

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-31

    The symposium on thermal solar energy utilization focussed on embracing aspects of thermal solar energy, standardization, testing, quality assurance, and the use of passive solar energy. Each of the 23 papers given at the meeting was abstracted for separate entry into the data base. (BWI). [Deutsch] Im Mittelpunkt des Symposiums zur thermischen Solarenergienutzung stehen uebergreifende Aspekte der thermischen Solarenergie, Normung, Test und Qualitaetssicherung sowie die Nutzung der passiven Solarenergie. Fuer alle 23 enthaltenen Fachbeitraege wurde eine gesonderte inhaltliche Erschliessung durchgefuehrt. (BWI).

  5. Thermodynamic analysis of siphon flash evaporation desalination system using ocean thermal energy

    International Nuclear Information System (INIS)

    Jin, Zhi-jiang; Ye, Hao; Wang, Hao; Li, Hao; Qian, Jin-yuan

    2017-01-01

    Highlights: • Siphon flash evaporation desalination system using ocean thermal energy. • Exergy efficiency under design conditions. • Parametric studies using ASPEN Plus. • Experimental studies on the performance of the system. - Abstract: Ocean thermal energy refers to the thermal potential energy produced by the temperature difference between the warm surface seawater and the cold deep seawater. In this paper, a siphon flash evaporation desalination system using ocean thermal energy is proposed. Because it can utilize the ocean thermal energy directly for desalination, siphon flash evaporation desalination system has relatively higher energy efficiency compared with converting ocean thermal energy into electric energy and then using electric energy for desalination. The working principle of this system is introduced firstly. Then, the exergy, exergy loss and exergy efficiency in the flash evaporation, condensation and the whole system are carried out quantitatively. The results show that the exergy efficiency of the system which directly utilizing ocean thermal energy for desalination reaches to 7.81% under design conditions; lower surface seawater temperature, higher deep seawater temperature and higher flash temperature can result in an increasing of system efficiency, while the whole energy consumption shall also be taken into consideration. Then the simulation model of the whole system is created in ASPEN PLUS in order to investigate the influence of some most important parameters, such as surface seawater temperatures, deep seawater temperatures and difference of inlet temperature between surface and deep seawater. Finally, an experimental platform is established based on the working principle and process to verify the validity of the working principle and the simulation model. The siphon flash evaporation desalination system provides a novel method of direct high efficient conversion and utilization of ocean thermal energy and this work can provide

  6. Waste-to-Energy Thermal Destruction Identification for Forward Operating Bases

    Science.gov (United States)

    2016-07-01

    Approved for public release; distribution is unlimited TECHNICAL REPORT TR-NAVFAC-EXWC-EV-1703 JULY 2016 WASTE -TO- ENERGY THERMAL DESTRUCTION...To) 2015-2016 4. TITLE AND SUBTITLE Waste -to- Energy Thermal Destruction Identification for Forward Operating Bases 5a. CONTRACT NUMBER 5b...successfully integrating the sub-processes together and meeting the expeditionary requirements of each service branch. 15. SUBJECT TERMS Waste to Energy

  7. PCM/wood composite to store thermal energy in passive building envelopes

    Science.gov (United States)

    Barreneche, C.; Vecstaudza, J.; Bajare, D.; Fernandez, A. I.

    2017-10-01

    The development of new materials to store thermal energy in a passive building system is a must to improve the thermal efficiency by thermal-regulating the indoor temperatures. This fact will deal with the reduction of the gap between energy supply and energy demand to achieve thermal comfort in building indoors. The aim of this work was to test properties of novel PCM/wood composite materials developed at Riga Technical University. Impregnation of PCM (phase change material) in wood increases its thermal mass and regulates temperature fluctuations during day and night. The PCM used are paraffin waxes (RT-21 and RT-27 from Rubitherm) and the wood used was black alder, the most common wood in Latvia. The PCM distribution inside wood sample has been studied as well as its thermophysical, mechanical and fire reaction properties. Developed composite materials are promising in the field of energy saving in buildings.

  8. The Significance of Temperature Based Approach Over the Energy Based Approaches in the Buildings Thermal Assessment

    Science.gov (United States)

    Albatayneh, Aiman; Alterman, Dariusz; Page, Adrian; Moghtaderi, Behdad

    2017-05-01

    The design of low energy buildings requires accurate thermal simulation software to assess the heating and cooling loads. Such designs should sustain thermal comfort for occupants and promote less energy usage over the life time of any building. One of the house energy rating used in Australia is AccuRate, star rating tool to assess and compare the thermal performance of various buildings where the heating and cooling loads are calculated based on fixed operational temperatures between 20 °C to 25 °C to sustain thermal comfort for the occupants. However, these fixed settings for the time and temperatures considerably increase the heating and cooling loads. On the other hand the adaptive thermal model applies a broader range of weather conditions, interacts with the occupants and promotes low energy solutions to maintain thermal comfort. This can be achieved by natural ventilation (opening window/doors), suitable clothes, shading and low energy heating/cooling solutions for the occupied spaces (rooms). These activities will save significant amount of operating energy what can to be taken into account to predict energy consumption for a building. Most of the buildings thermal assessment tools depend on energy-based approaches to predict the thermal performance of any building e.g. AccuRate in Australia. This approach encourages the use of energy to maintain thermal comfort. This paper describes the advantages of a temperature-based approach to assess the building's thermal performance (using an adaptive thermal comfort model) over energy based approach (AccuRate Software used in Australia). The temperature-based approach was validated and compared with the energy-based approach using four full scale housing test modules located in Newcastle, Australia (Cavity Brick (CB), Insulated Cavity Brick (InsCB), Insulated Brick Veneer (InsBV) and Insulated Reverse Brick Veneer (InsRBV)) subjected to a range of seasonal conditions in a moderate climate. The time required for

  9. A comparison of experimental thermal stratification parameters for an oil/pebble-bed thermal energy storage (TES) system during charging

    International Nuclear Information System (INIS)

    Mawire, Ashmore; Taole, Simeon H.

    2011-01-01

    Highlights: → Six experimental thermal stratification parameters are evaluated in a TES system. → Stratification number and temperature difference evaluate stratification adequately. → Exergy efficiency and Reynolds number evaluate stratification qualitatively. → Richardson number and energy efficiency not clearly related with stratification. -- Abstract: Six different experimental thermal stratification evaluation parameters during charging for an oil/pebble-bed TES system are presented. The six parameters are the temperature distribution along the height of the storage tank at different time intervals, the charging energy efficiency, the charging exergy efficiency, the stratification number, the Reynolds number and the Richardson number. These parameters are evaluated under six different experimental charging conditions. Temperature distribution along the height of the storage tank at different time intervals and the stratification number are parameters found to describe thermal stratification quantitatively adequately. On the other-hand, the charging exergy efficiency and the Reynolds number give important information about describing thermal stratification qualitatively and should be used with care. The charging energy efficiency and the Richardson number have no clear relationship with thermal stratification.

  10. Utilization of solar thermal energy in the mining industry: applied case solar thermal systems for hot water heating - Mining camps

    Energy Technology Data Exchange (ETDEWEB)

    Vasquez Mena, Horacio [Portal Sustentable and Enerficaz (Chile)

    2010-07-01

    The paper gives an overview of how solar thermal energy can be used in the mining industry. This is done through a case study of solar thermal systems (STS) for hot water heating in mining camps in Chile. Solar thermal energy has various applications, such as heating and air conditioning. Solar radiation between 600 to 800w/m2 only can be used for solar thermal systems. Solar collectors can be of two types, flat plate or vacuum tube. Various techniques can be used to model solar thermal systems: Transol, RET screen, T-sol, Static model and F-chart. Chile has the great advantage of being one of the countries with the highest levels of solar radiation. Technical data for the solar collector and the heat pump used for the study are given. The collector performance was evaluated throughout the year and the actual results achieved were compared with those projected. The paper concludes that STS are a good source of renewable energy. They are efficient, cheap, and they have a small carbon footprint.

  11. Preparation, characterization and thermal studies of polymer inclusion cellulose acetate membrane with calix[4]resorcinarenes as carriers

    Energy Technology Data Exchange (ETDEWEB)

    Benosmane, Nadjib [Laboratoire de Chimie Organique Appliquee (Groupe Heterocycles Associe CRAPC), Faculte de Chimie, Universite des Sciences et de la Technologie Houari Boumediene, BP 32, El-Alia, 16111 Bab-Ezzouar, Alger (Algeria); Guedioura, Bouzid [Division reacteur/Centre de Recherche Nucleaire de Draria, CRND, BP 43 Draria, Alger (Algeria); Hamdi, Safouane Mohammed [Laboratoire de Biochimie-Purpan, Institut Federatif de Biologie, CHU Toulouse 330, avenue de Grande-Bretagne - F-31059 Toulouse Cedex 9 (France); Hamdi, Maamar [Laboratoire de Chimie Organique Appliquee (Groupe Heterocycles Associe CRAPC), Faculte de Chimie, Universite des Sciences et de la Technologie Houari Boumediene, BP 32, El-Alia, 16111 Bab-Ezzouar, Alger (Algeria); Boutemeur, Baya, E-mail: bayakheddis@hotmail.com [Laboratoire de Chimie Organique Appliquee (Groupe Heterocycles Associe CRAPC), Faculte de Chimie, Universite des Sciences et de la Technologie Houari Boumediene, BP 32, El-Alia, 16111 Bab-Ezzouar, Alger (Algeria)

    2010-07-20

    A polymer inclusion membrane (PIM) system with cellulose acetate polymer as support and calix[4]resorcinarenes as carriers has been developed. Special attention was paid to PIM characterization using scanning electron microscopy, Fourier-transform infra-red study, X-ray scattering and thermogravimetric analyses. The efficiency of the membrane transport was optimized as a function of pH, stirring speed, aqueous phases and membrane composition. The results suggested that the transport mechanism is a counter-transport of protons, the mechanism was mainly controlled by the diffusion of the complex formed in the membrane core. Analysis of lead(II) transport through these PIMs was performed. It was found that calix[4]resorcinarenes containing membranes were flexible, resistant and heterogeneous without plasticizer addition.

  12. Characteristics Study of Photovoltaic Thermal System with Emphasis on Energy Efficiency

    Directory of Open Access Journals (Sweden)

    Yong Chuah Yee

    2018-01-01

    Full Text Available Solar energy is typically collected through photovoltaic (PV to generate electricity or through thermal collectors as heat energy, they are generally utilised separately. This project is done with the purpose of integrating the two systems to improve the energy efficiency. The idea of this photovoltaic-thermal (PVT setup design is to simultaneously cool the PV panel so it can operate at a lower temperature thus higher electrical efficiency and also store the thermal energy. The experimental data shows that the PVT setup increased the electrical efficiency of the standard PV setup from 1.64% to 2.15%. The integration of the thermal collector also allowed 37.25% of solar energy to be stored as thermal energy. The standard PV setup harnessed only 1.64% of the solar energy, whereas the PVT setup achieved 39.4%. Different flowrates were tested to determine its effects on the PVT setup’s electrical and thermal efficiency. The various flowrate does not significantly impact the electrical efficiency since it did not significantly impact the cooling of the panel. The various flowrates resulted in fluctuating thermal efficiencies, the relation between the two is inconclusive in this project.

  13. Joint energy demand and thermal comfort optimization in photovoltaic-equipped interconnected microgrids

    International Nuclear Information System (INIS)

    Baldi, Simone; Karagevrekis, Athanasios; Michailidis, Iakovos T.; Kosmatopoulos, Elias B.

    2015-01-01

    Highlights: • Energy efficient operation of photovoltaic-equipped interconnected microgrids. • Optimized energy demand for a block of heterogeneous buildings with different sizes. • Multiobjective optimization: matching demand and supply taking into account thermal comfort. • Intelligent control mechanism for heating, ventilating, and air conditioning units. • Optimization of energy consumption and thermal comfort at the aggregate microgrid level. - Abstract: Electrical smart microgrids equipped with small-scale renewable-energy generation systems are emerging progressively as an alternative or an enhancement to the central electrical grid: due to the intermittent nature of the renewable energy sources, appropriate algorithms are required to integrate these two typologies of grids and, in particular, to perform efficiently dynamic energy demand and distributed generation management, while guaranteeing satisfactory thermal comfort for the occupants. This paper presents a novel control algorithm for joint energy demand and thermal comfort optimization in photovoltaic-equipped interconnected microgrids. Energy demand shaping is achieved via an intelligent control mechanism for heating, ventilating, and air conditioning units. The intelligent control mechanism takes into account the available solar energy, the building dynamics and the thermal comfort of the buildings’ occupants. The control design is accomplished in a simulation-based fashion using an energy simulation model, developed in EnergyPlus, of an interconnected microgrid. Rather than focusing only on how each building behaves individually, the optimization algorithm employs a central controller that allows interaction among the buildings of the microgrid. The control objective is to optimize the aggregate microgrid performance. Simulation results demonstrate that the optimization algorithm efficiently integrates the microgrid with the photovoltaic system that provides free electric energy: in

  14. Product distributions for some thermal energy charge transfer reactions of rare gas ions

    Science.gov (United States)

    Anicich, V. G.; Laudenslager, J. B.; Huntress, W. T., Jr.; Futrell, J. H.

    1977-01-01

    Ion cyclotron resonance methods were used to measure the product distributions for thermal-energy charge-transfer reactions of He(+), Ne(+), and Ar(+) ions with N2, O2, CO, NO, CO2, and N2O. Except for the He(+)-N2 reaction, no molecular ions were formed by thermal-energy charge transfer from He(+) and Ne(+) with these target molecules. The propensity for dissociative ionization channels in these highly exothermic charge-transfer reactions at thermal energies contrasts with the propensity for formation of parent molecular ions observed in photoionization experiments and in high-energy charge-transfer processes. This difference is explained in terms of more stringent requirements for energy resonance and favorable Franck-Condon factors at thermal ion velocities.

  15. Advanced thermal energy management: A thermal test bed and heat pipe simulation

    Science.gov (United States)

    Barile, Ronald G.

    1986-01-01

    Work initiated on a common-module thermal test simulation was continued, and a second project on heat pipe simulation was begun. The test bed, constructed from surplus Skylab equipment, was modeled and solved for various thermal load and flow conditions. Low thermal load caused the radiator fluid, Coolanol 25, to thicken due to its temperature avoided by using a regenerator-heat-exchanger. Other possible solutions modeled include a radiator heater and shunting heat from the central thermal bus to the radiator. Also, module air temperature can become excessive with high avionics load. A second preoject concerning advanced heat pipe concepts was initiated. A program was written which calculates fluid physical properties, liquid and vapor pressure in the evaporator and condenser, fluid flow rates, and thermal flux. The program is directed to evaluating newer heat pipe wicks and geometries, especially water in an artery surrounded by six vapor channels. Effects of temperature, groove and slot dimensions, and wick properties are reported.

  16. Reactive Transport Modeling of Thermal Column Experiments to Investigate the Impacts of Aquifer Thermal Energy Storage on Groundwater Quality

    NARCIS (Netherlands)

    Bonte, M.; Stuijfzand, P.J.; van Breukelen, B.M.

    2014-01-01

    Aquifer thermal energy storage (ATES) systems are increasingly being used to acclimatize buildings and are often constructed in aquifers used for drinking water supply. This raises the question of potential groundwater quality impact. Here, we use laboratory column experiments to develop and

  17. Preparation, characterization, and thermal properties of starch microencapsulated fatty acids as phase change materials thermal energy storage applications

    Science.gov (United States)

    Stable starch-oil composites can be prepared from renewable resources by excess steam jet-cooking aqueous slurries of starch and vegetable oils or other hydrophobic materials. Fatty acids such as stearic acid are promising phase change materials (PCMs) for latent heat thermal energy storage applica...

  18. The very early thermal state of Terra Cimmeria: Implications for magnetic carriers in the crust of Mars

    OpenAIRE

    Ruiz Pérez, Javier

    2009-01-01

    Large areas of strongly magnetized crust are located in Terra Cimmeria and Terra Sirenum, in the southern highlands of Mars, the older terrains on the planet. The typical depth to the base of the magnetized layer, deduced from the magnetic spectrum of Mars and modeling of isolated magnetic anomalies, would 40–60 km. In this paper the thermal state of Terra Cimmeria is revisited by calculating heat flows and crustal geotherms consistent with a previous estimation of the effective e...

  19. Wind Energy to Thermal and Cold Storage – A Systems Approach

    DEFF Research Database (Denmark)

    Xydis, George

    2013-01-01

    In this paper wind energy to thermal and cold storage scenarios were examined to enable high wind integration through converting renewable electricity excess into thermal or cooling energy, saving part of the energy used in an area and eliminating the need to possibly build a new coal fired plant....... Case studies in Crete Island (not interconnected to the power grid of Greek mainland) with onshore wind power installed were investigated. The aim of this work was to review the options for greater integration of renewables into the grid and the main idea was to analyze the wind to thermal and to cold...... storage according to the needs of two small municipalities....

  20. Urbach's rule derived from thermal fluctuations in the band-gap energy

    DEFF Research Database (Denmark)

    Skettrup, Torben

    1978-01-01

    The exponential absorption edge (known as Urbach's rule) observed in most materials is interpreted in terms of thermal fluctuations in the band-gap energy. The main contribution to the temperature shift of the band-gap energy is due to the temperature-dependent self-energies of the electrons...... and holes interacting with the phonons. Since the phonon number is fluctuating in thermal equilibrium, the band-gap energy is also fluctuating resulting in an exponential absorption tail below the average band-gap energy. These simple considerations are applied to derive Urbach's rule at high temperatures...

  1. Developing a cost effective rock bed thermal energy storage system: Design and modelling

    Science.gov (United States)

    Laubscher, Hendrik Frederik; von Backström, Theodor Willem; Dinter, Frank

    2017-06-01

    Thermal energy storage is an integral part of the drive for low cost of concentrated solar power (CSP). Storage of thermal energy enables CSP plants to provide base load power. Alternative, cheaper concepts for storing thermal energy have been conceptually proposed in previous studies. Using rocks as a storage medium and air as a heat transfer fluid, the proposed concept offers the potential of lower cost storage because of the abundance and affordability of rocks. A packed rock bed thermal energy storage (TES) concept is investigated and a design for an experimental rig is done. This paper describes the design and modelling of an experimental test facility for a cost effective packed rock bed thermal energy storage system. Cost effective, simplified designs for the different subsystems of an experimental setup are developed based on the availability of materials and equipment. Modelling of this design to predict the thermal performance of the TES system is covered in this study. If the concept under consideration proves to be successful, a design that is scalable and commercially viable can be proposed for further development of an industrial thermal energy storage system.

  2. Enhanced thermal conductivity of form-stable phase change composite with single-walled carbon nanotubes for thermal energy storage.

    Science.gov (United States)

    Qian, Tingting; Li, Jinhong; Feng, Wuwei; Nian, Hong'en

    2017-03-16

    A striking contrast in the thermal conductivities of polyethylene glycol (PEG)/diatomite form-stable phase change composite (fs-PCC) with single-walled carbon nanotubes (SWCNs) as nano-additive has been reported in our present study. Compared to the pure PEG, the thermal conductivity of the prepared fs-PCC has increased from 0.24 W/mK to 0.87 W/Mk with a small SWCNs loading of 2 wt%. SWCNs are decorated on the inner surface of diatomite pores whilst retaining its porous structure. Compared to PEG/diatomite fs-PCC, the melting and solidification time of the PEG/diatomite/SWCNs fs-PCC are respectively decreased by 54.7% and 51.1%, and its thermal conductivity is 2.8 times higher. The composite can contain PEG as high as 60 wt% and maintain its original shape perfectly without any PEG leakage after subjected to 200 melt-freeze cycles. DSC results indicates that the melting point of the PEG/diatomite/SWCNs fs-PCC shifts to a lower temperature while the solidification point shifts to a higher temperature due to the presence of SWCNs. Importantly, the use of SWCNs is found to have clear beneficial effects for enhancing the thermal conductivity and thermal storage/release rates, without affecting thermal properties, chemical compatibility and thermal stability. The prepared PEG/diatomite/SWCNs fs-PCC exhibits excellent chemical and thermal durability and has potential application in solar thermal energy storage and solar heating.

  3. Numerical investigation of a joint approach to thermal energy storage and compressed air storage in aquifers

    OpenAIRE

    Guo, Chaobin.; Zhanga, Keni.; Pan, Lehua.; Cai, Zuansi.; Lid, Cai.; Lie, Yi.

    2017-01-01

    Different from conventional compressed air energy storage (CAES) systems, the advanced adiabatic compressed air energy storage (AA-CAES) system can store the compression heat which can be used to reheat air during the electricity generation stage. Thus, AA-CAES system can achieve a higher energy storage efficiency. Similar to the AA-CAES system, a compressed air energy storage in aquifers (CAESA) system, which is integrated with an aquifer thermal energy storage (ATES) could possibly achieve ...

  4. Coral mucus functions as an energy carrier and particle trap in the reef ecosystem

    DEFF Research Database (Denmark)

    Wild, C.; Huettel, M.; Klueter, A.

    2004-01-01

    Zooxanthellae, endosymbiotic algae of reef-building corals, substantially contribute to the high gross primary production of coral reefs(1), but corals exude up to half of the carbon assimilated by their zooxanthellae as mucus(2,3). Here we show that released coral mucus efficiently traps organic...... matter from the water column and rapidly carries energy and nutrients to the reef lagoon sediment, which acts as a biocatalytic mineralizing filter. In the Great Barrier Reef, the dominant genus of hard corals, Acropora, exudes up to 4.8 litres of mucus per square metre of reef area per day. Between 56......% and 80% of this mucus dissolves in the reef water, which is filtered through the lagoon sands. Here, coral mucus is degraded at a turnover rate of at least 7% per hour. Detached undissolved mucus traps suspended particles, increasing its initial organic carbon and nitrogen content by three orders...

  5. Thermal solar energy in Spain. State of the art and objectives; Energie solaire thermique en Espagne. Etat actuel et objectifs

    Energy Technology Data Exchange (ETDEWEB)

    Glenn, Jaouen

    2006-07-01

    According the Kyoto protocol, Spain has to reduce its CO{sub 2} emissions at 330 millions of tons (a decrease of 18 % from the level of 2003). From the european commission policy, the energy resources will be of 12 % of renewable energies. In this context, Spain developed an energy policy in favor of the solar energy. This document provides information on: the energy market in Spain, the thermal solar energy operating, the CO{sub 2} emissions, the state of the art in the domain in spain, the 2010 objectives, the programs and the assistance, some data on the solar market in comparison with the Europe. (A.L.B.)

  6. Production of thermal and electrical energy in the small and middle cogeneration gas electrical plants, v. 16(61)

    International Nuclear Information System (INIS)

    Vasilevski, Gotse; Krstevski, Gjorgje

    2008-01-01

    Production of thermal and electrical energy leads to numerous problems which need to be solved in the large energy systems. Some problems as consumption of predefined energy (electrical energy or thermal energy as hot water or steam) in time and space domain can be solved through the usage of cogeneration units with high efficiency parameters. (Author)

  7. Thermal and Optical Modulation of the Carrier Mobility in OTFTs Based on an Azo-anthracene Liquid Crystal Organic Semiconductor.

    Science.gov (United States)

    Chen, Yantong; Li, Chao; Xu, Xiuru; Liu, Ming; He, Yaowu; Murtaza, Imran; Zhang, Dongwei; Yao, Chao; Wang, Yongfeng; Meng, Hong

    2017-03-01

    One of the most striking features of organic semiconductors compared with their corresponding inorganic counterparts is their molecular diversity. The major challenge in organic semiconductor material technology is creating molecular structural motifs to develop multifunctional materials in order to achieve the desired functionalities yet to optimize the specific device performance. Azo-compounds, because of their special photoresponsive property, have attracted extensive interest in photonic and optoelectronic applications; if incorporated wisely in the organic semiconductor groups, they can be innovatively utilized in advanced smart electronic applications, where thermal and photo modulation is applied to tune the electronic properties. On the basis of this aspiration, a novel azo-functionalized liquid crystal semiconductor material, (E)-1-(4-(anthracen-2-yl)phenyl)-2-(4-(decyloxy)phenyl)diazene (APDPD), is designed and synthesized for application in organic thin-film transistors (OTFTs). The UV-vis spectra of APDPD exhibit reversible photoisomerizaton upon photoexcitation, and the thin films of APDPD show a long-range orientational order based on its liquid crystal phase. The performance of OTFTs based on this material as well as the effects of thermal treatment and UV-irradiation on mobility are investigated. The molecular structure, stability of the material, and morphology of the thin films are characterized by thermal gravimetric analysis (TGA), polarizing optical microscopy (POM), (differential scanning calorimetry (DSC), UV-vis spectroscopy, atomic force microscopy (AFM), and scanning tunneling microscopy (STM). This study reveals that our new material has the potential to be applied in optical sensors, memories, logic circuits, and functional switches.

  8. Thermal Performance Benchmarking; NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Gilbert

    2015-06-09

    This project proposes to seek out the SOA power electronics and motor technologies to thermally benchmark their performance. The benchmarking will focus on the thermal aspects of the system. System metrics including the junction-to-coolant thermal resistance and the parasitic power consumption (i.e., coolant flow rates and pressure drop performance) of the heat exchanger will be measured. The type of heat exchanger (i.e., channel flow, brazed, folded-fin) and any enhancement features (i.e., enhanced surfaces) will be identified and evaluated to understand their effect on performance. Additionally, the thermal resistance/conductivity of the power module’s passive stack and motor’s laminations and copper winding bundles will also be measured. The research conducted will allow insight into the various cooling strategies to understand which heat exchangers are most effective in terms of thermal performance and efficiency. Modeling analysis and fluid-flow visualization may also be carried out to better understand the heat transfer and fluid dynamics of the systems.

  9. Transition Region Emission and the Energy Input to Thermal Plasma in Solar Flares

    Science.gov (United States)

    Holman, Gordon D.; Holman, Gordon D.; Dennis, Brian R.; Haga, Leah; Raymond, John C.; Panasyuk, Alexander

    2005-01-01

    Understanding the energetics of solar flares depends on obtaining reliable determinations of the energy input to flare plasma. X-ray observations of the thermal bremsstrahlung from hot flare plasma provide temperatures and emission measures which, along with estimates of the plasma volume, allow the energy content of this hot plasma to be computed. However, if thermal energy losses are significant or if significant energy goes directly into cooler plasma, this is only a lower limit on the total energy injected into thermal plasma during the flare. We use SOHO UVCS observations of O VI flare emission scattered by coronal O VI ions to deduce the flare emission at transition region temperatures between 100,000 K and 1 MK for the 2002 July 23 and other flares. We find that the radiated energy at these temperatures significantly increases the deduced energy input to the thermal plasma, but by an amount that is less than the uncertainty in the computed energies. Comparisons of computed thermal and nonthermal electron energies deduced from RHESSI, GOES, and UVCS are shown.

  10. Solar thermal energy for supplemental heat to process tea in Sri Lanka

    Energy Technology Data Exchange (ETDEWEB)

    Ariyaratne, A.R.

    1987-01-01

    In tea processing, the subprocesses of withering and drying require thermal energy for dehydration of tea leaves. At present, the Sri Lankan tea industry depends mostly on imported fossil fuels for its thermal energy needs. The economic pressure has forced the industry to investigate energy alternatives. In this study solar thermal energy, heat recovery from fluidized-bed dryers, and a combination of solar system with heat recovery were analyzed. The /phi/, f-chart general design method was used to design solar systems to match thermal energy needs in tea processing. The analysis was extended to the f-chart economic analysis to select economically optimum systems. On the basis of highest life-cycle savings, flat-plate solar-collector area and storage tank were sized. Results showed that solar thermal systems require a high investment,but can provide 42, 52, and 63% of the energy needs for high, mid and low tea growing regions, respectively. Combination of solar thermal systems with heat recovery from a fluidized-bed dryer decreases the amount of energy required by another 7 to 12% yet requires only a small increase in investment.

  11. Experimental Validation of Source Temperature Modulation Via a Thermal Switch in Thermal Energy Harvesting (Preprint)

    National Research Council Canada - National Science Library

    McCarty, R; Monaghan, D; Hallinan, K. P; Sanders, B

    2007-01-01

    This paper provides a description of research seeking to experimentally verify the effectiveness of a thermal switch used in series with TE devices for waste heat recovery for constant and variable...

  12. An improved method for upscaling borehole thermal energy storage using inverse finite element modelling

    DEFF Research Database (Denmark)

    Tordrup, Karl Woldum; Poulsen, Søren Erbs; Bjørn, Henrik

    2017-01-01

    Dimensioning of large-scale borehole thermal energy storage (BTES) is inherently uncertain due to the natural variability of thermal conductivity and heat capacity in the storage volume. We present an improved method for upscaling a pilot BTES to full scale and apply the method to an operational...

  13. A Simplified Tool for Predicting the Thermal Behavior and the Energy Saving Potential of Ventilated Windows

    DEFF Research Database (Denmark)

    Zhang, Chen; Heiselberg, Per Kvols; Larsen, Olena Kalyanova

    2016-01-01

    Currently, the studies of ventilated windows mainly rely on complex fluid and thermal simulation software, which require extensive information, data and are very time consuming. The aim of this paper is to develop a simplified tool to assess the thermal behavior and energy performance of ventilat...

  14. Thermal Comfort and Ventilation Criteria for low Energy Residential Buildings in Building Codes

    DEFF Research Database (Denmark)

    Cao, Guangyu; Kurnitski, Jarek; Awbi, Hazim

    2012-01-01

    of the indoor air quality in such buildings. Currently, there are no global guidelines for specifying the indoor thermal environment in such low-energy buildings. The objective of this paper is to analyse the classification of indoor thermal comfort levels and recommended ventilation rates for different low...

  15. Performance results of a solar greenhouse combining electrical and thermal energy production

    NARCIS (Netherlands)

    Sonneveld, P.J.; Swinkels, G.L.A.M.; Campen, J.B.; Tuijl, van B.A.J.; Janssen, H.J.J.; Bot, G.P.A.

    2010-01-01

    Performance results are given of a new type of greenhouse, which combines reflection of near infrared radiation (NIR) with electrical power generation using hybrid photovoltaic cell/thermal collector modules. Besides the generation of electrical and thermal energy, the reflection of the NIR will

  16. Accelerated Thermal Cycling Test of Microencapsulated Paraffin Wax/Polyaniline Made by Simple Preparation Method for Solar Thermal Energy Storage.

    Science.gov (United States)

    Silakhori, Mahyar; Naghavi, Mohammad Sajad; Metselaar, Hendrik Simon Cornelis; Mahlia, Teuku Meurah Indra; Fauzi, Hadi; Mehrali, Mohammad

    2013-04-29

    Microencapsulated paraffin wax/polyaniline was prepared using a simple in situ polymerization technique, and its performance characteristics were investigated. Weight losses of samples were determined by Thermal Gravimetry Analysis (TGA). The microencapsulated samples with 23% and 49% paraffin showed less decomposition after 330 °C than with higher percentage of paraffin. These samples were then subjected to a thermal cycling test. Thermal properties of microencapsulated paraffin wax were evaluated by Differential Scanning Calorimeter (DSC). Structure stability and compatibility of core and coating materials were also tested by Fourier transform infrared spectrophotometer (FTIR), and the surface morphology of the samples are shown by Field Emission Scanning Electron Microscopy (FESEM). It has been found that the microencapsulated paraffin waxes show little change in the latent heat of fusion and melting temperature after one thousand thermal recycles. Besides, the chemical characteristics and structural profile remained constant after one thousand thermal cycling tests. Therefore, microencapsulated paraffin wax/polyaniline is a stable material that can be used for thermal energy storage systems.

  17. Energy thresholds of discrete breathers in thermal equilibrium and relaxation processes.

    Science.gov (United States)

    Ming, Yi; Ling, Dong-Bo; Li, Hui-Min; Ding, Ze-Jun

    2017-06-01

    So far, only the energy thresholds of single discrete breathers in nonlinear Hamiltonian systems have been analytically obtained. In this work, the energy thresholds of discrete breathers in thermal equilibrium and the energy thresholds of long-lived discrete breathers which can remain after a long time relaxation are analytically estimated for nonlinear chains. These energy thresholds are size dependent. The energy thresholds of discrete breathers in thermal equilibrium are the same as the previous analytical results for single discrete breathers. The energy thresholds of long-lived discrete breathers in relaxation processes are different from the previous results for single discrete breathers but agree well with the published numerical results known to us. Because real systems are either in thermal equilibrium or in relaxation processes, the obtained results could be important for experimental detection of discrete breathers.

  18. Collection and dissemination of thermal energy storage system information for the pulp and paper industry

    Science.gov (United States)

    Edde, H.

    1981-01-01

    The collection and dissemination of thermal energy storage (TES) system technology for the pulp and paper industry with the intent of reducing fossil fuel usage is discussed. The study plan is described and a description presented of example TES systems.

  19. Application of thermal energy storage to process heat recovery in the aluminum industry

    Science.gov (United States)

    Mccabe, J.

    1980-01-01

    The economic viability and the institutional compatibility of a district heating system in the city of Bellingham, Washington are assessed and the technical and economic advantages of using thermal energy storage methods are determined.

  20. On-Board Thermal Management of Waste Heat from a High-Energy Device

    National Research Council Canada - National Science Library

    Klatt, Nathan D

    2008-01-01

    The use of on-board high-energy devices such as megawatt lasers and microwave emitters requires aircraft system integration of thermal devices to either get rid of waste heat or utilize it in other areas of the aircraft...

  1. Candidate thermal energy storage technologies for solar industrial process heat applications

    Science.gov (United States)

    Furman, E. R.

    1979-01-01

    A number of candidate thermal energy storage system elements were identified as having the potential for the successful application of solar industrial process heat. These elements which include storage media, containment and heat exchange are shown.

  2. Low-temperature thermal energy storage program annual operating plan

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, H. W.; Eissenberg, D. M.

    1979-01-01

    The LTTES program operating plans for FY 1978 are described in terms of general program objectives and the technical activities being implemented to achieve these objectives. The program structure provides emphasis on several principal thrusts; namely, seasonal thermal storage, daily/short-term thermal storage, and waste heat recovery and reuse. A work breakdown structure (WBS) organizes the efforts being carried out in-house or through subcontract within each thrust area. Fiscal data are summarized in respect to thrust area, individual efforts, and funding source.

  3. Heat transfer efficient thermal energy storage for steam generation

    International Nuclear Information System (INIS)

    Adinberg, R.; Zvegilsky, D.; Epstein, M.

    2010-01-01

    A novel reflux heat transfer storage (RHTS) concept for producing high-temperature superheated steam in the temperature range 350-400 deg. C was developed and tested. The thermal storage medium is a metallic substance, Zinc-Tin alloy, which serves as the phase change material (PCM). A high-temperature heat transfer fluid (HTF) is added to the storage medium in order to enhance heat exchange within the storage system, which comprises PCM units and the associated heat exchangers serving for charging and discharging the storage. The applied heat transfer mechanism is based on the HTF reflux created by a combined evaporation-condensation process. It was shown that a PCM with a fraction of 70 wt.% Zn in the alloy (Zn70Sn30) is optimal to attain a storage temperature of 370 deg. C, provided the heat source such as solar-produced steam or solar-heated synthetic oil has a temperature of about 400 deg. C (typical for the parabolic troughs technology). This PCM melts gradually between temperatures 200 and 370 deg. C preserving the latent heat of fusion, mainly of the Zn-component, that later, at the stage of heat discharge, will be available for producing steam. The thermal storage concept was experimentally studied using a lab scale apparatus that enabled investigating of storage materials (the PCM-HTF system) simultaneously with carrying out thermal performance measurements and observing heat transfer effects occurring in the system. The tests produced satisfactory results in terms of thermal stability and compatibility of the utilized storage materials, alloy Zn70Sn30 and the eutectic mixture of biphenyl and diphenyl oxide, up to a working temperature of 400 deg. C. Optional schemes for integrating the developed thermal storage into a solar thermal electric plant are discussed and evaluated considering a pilot scale solar plant with thermal power output of 12 MW. The storage should enable uninterrupted operation of solar thermal electric systems during additional hours

  4. Energy indicators impact in multi-criteria sustainability analyse of thermal power plant unit

    OpenAIRE

    Škobalj Predrag D.; Kijevčanin Mirjana Lj.; Jovanović Marina P.; Afgan Naim H.; Erić Milić D.

    2017-01-01

    This paper presents method for sustainability assessment of thermal power plant unit using multi-criteria analysis with aim to create base for business decision. Seven options of possible status of thermal power plant „Kolubara A” unit No. 2 with energy indicators of sustainable development were shown. Energy indicators of sustainable development consists of sets of resource preservation, economic, environmental, and social indicators. Sustainability assessment often fails to account for soci...

  5. Thermal emissions and climate change: Cooler options for future energy technology

    OpenAIRE

    Cowern, Nick E. B.; Ahn, Chihak

    2008-01-01

    Global warming arises from 'temperature forcing', a net imbalance between energy fluxes entering and leaving the climate system and arising within it. Humanity introduces temperature forcing through greenhouse gas emissions, agriculture, and thermal emissions from fuel burning. Up to now climate projections, neglecting thermal emissions, typically foresee maximum forcing around the year 2050, followed by a decline. In this paper we show that, if humanity's energy use grows at 1%/year, slower ...

  6. Applications of thermal energy storage to waste heat recovery in the food processing industry

    Science.gov (United States)

    Wojnar, F.; Lunberg, W. L.

    1980-01-01

    A study to assess the potential for waste heat recovery in the food industry and to evaluate prospective waste heat recovery system concepts employing thermal energy storage was conducted. The study found that the recovery of waste heat in canning facilities can be performed in significant quantities using systems involving thermal energy storage that are both practical and economical. A demonstration project is proposed to determine actual waste heat recovery costs and benefits and to encourage system implementation by the food industry.

  7. Comparative Study of Electric Energy Storages and Thermal Energy Auxiliaries for Improving Wind Power Integration in the Cogeneration System

    Directory of Open Access Journals (Sweden)

    Yanjuan Yu

    2018-01-01

    Full Text Available In regards to the cogeneration system in Northern China, mainly supported by combined heat and power (CHP plants, it usually offers limited operation flexibility due to the joint production of electric and thermal power. For that large-scale wind farms included in the cogeneration system, a large amount of wind energy may have to be wasted. To solve this issue, the utilization of the electric energy storages and the thermal energy auxiliaries are recommended, including pumped hydro storage (PHS, compressed air energy storage (CAES, hydrogen-based energy storage (HES, heat storage (HS, electric boilers (EB, and heat pumps (HP. This paper proposes a general evaluation method to compare the performance of these six different approaches for promoting wind power integration. In consideration of saving coal consumption, reducing CO2 emissions, and increasing investment cost, the comprehensive benefit is defined as the evaluation index. Specifically, a wind-thermal conflicting expression (WTCE is put forward to simplify the formulation of the comprehensive benefit. Further, according to the cogeneration system of the West Inner Mongolia (WIM power grid, a test system is modelled to perform the comparison of the six different approaches. The results show that introducing the electric energy storages and the thermal energy auxiliaries can both contribute to facilitating wind power integration, and the HP can provide the best comprehensive benefit.

  8. Myo-inositol based nano-PCM for solar thermal energy storage

    International Nuclear Information System (INIS)

    Singh, D.K.; Suresh, S.; Singh, H.; Rose, B.A.J.; Tassou, S.; Anantharaman, N.

    2017-01-01

    Highlights: • Properties of Myo-Inositol laden with Al 2 O 3 and CuO nanoparticles was studied. • The melting point was found to increase for MI-A and decrease for MI-C. • MI interacted only physically on addition of NPs. • Mass changes were <3% after thermal cycling of MI-A and MI-C. • MI-A is more suited for thermal energy storage than MI-C. - Abstract: The thermo-physical behavior of Myo-Inositol (MI), (a sugar alcohol), was investigated as a potential material for developing more compact solar thermal energy storage systems than those currently available. This latent heat storage medium could be utilized for commercial and industrial applications using solar thermal energy storage in the temperature range of 160–260 °C, if its thermal performance was modified. The objective of this investigation was to determine via experimentation, if Al 2 O 3 and CuO nanoparticles dispersed in pure MI for mixtures of 1, 2 and 3% (by weight) improved the thermal performance of MI for solar thermal energy systems. Nanoparticles only physically interacted with MI, and not chemically, even after 50 thermal cycles. The distribution of CuO nanoparticles in the nano-PCM was found to be more uniform than alumina nanoparticles. After cycling, nano-MIs studied here suffered a lower decrease in heat of fusion than pure MI, which makes nano-MIs more suitable for solar thermal storage applications at 160–260 °C. Between CuO and Al 2 O 3 nanoparticles, latter was found to be more suitable for compact solar thermal energy storage owing to an increase in melting point observed.

  9. Thermal Properties of Cement-Based Composites for Geothermal Energy Applications

    Directory of Open Access Journals (Sweden)

    Xiaohua Bao

    2017-04-01

    Full Text Available Geothermal energy piles are a quite recent renewable energy technique where geothermal energy in the foundation of a building is used to transport and store geothermal energy. In this paper, a structural–functional integrated cement-based composite, which can be used for energy piles, was developed using expanded graphite and graphite nanoplatelet-based composite phase change materials (CPCMs. Its mechanical properties, thermal-regulatory performance, and heat of hydration were evaluated. Test results showed that the compressive strength of GNP-Paraffin cement-based composites at 28 days was more than 25 MPa. The flexural strength and density of thermal energy storage cement paste composite decreased with increases in the percentage of CPCM in the cement paste. The infrared thermal image analysis results showed superior thermal control capability of cement based materials with CPCMs. Hence, the carbon-based CPCMs are promising thermal energy storage materials and can be used to improve the durability of energy piles.

  10. Comparison of carrier multiplication yields in PbS and PbSe nanocrystals: the role of competing energy-loss processes.

    Science.gov (United States)

    Stewart, John T; Padilha, Lazaro A; Qazilbash, M Mumtaz; Pietryga, Jeffrey M; Midgett, Aaron G; Luther, Joseph M; Beard, Matthew C; Nozik, Arthur J; Klimov, Victor I

    2012-02-08

    Infrared band gap semiconductor nanocrystals are promising materials for exploring generation III photovoltaic concepts that rely on carrier multiplication or multiple exciton generation, the process in which a single high-energy photon generates more than one electron-hole pair. In this work, we present measurements of carrier multiplication yields and biexciton lifetimes for a large selection of PbS nanocrystals and compare these results to the well-studied PbSe nanocrystals. The similar bulk properties of PbS and PbSe make this an important comparison for discerning the pertinent properties that determine efficient carrier multiplication. We observe that PbS and PbSe have very similar biexciton lifetimes as a function of confinement energy. Together with the similar bulk properties, this suggests that the rates of multiexciton generation, which is the inverse of Auger recombination, are also similar. The carrier multiplication yields in PbS nanocrystals, however, are strikingly lower than those observed for PbSe nanocrystals. We suggest that this implies the rate of competing processes, such as phonon emission, is higher in PbS nanocrystals than in PbSe nanocrystals. Indeed, our estimations for phonon emission mediated by the polar Fröhlich-type interaction indicate that the corresponding energy-loss rate is approximately twice as large in PbS than in PbSe. © 2011 American Chemical Society

  11. Forced transport of thermal energy in magmatic and phreatomagmatic large volume ignimbrites: Paleomagnetic evidence from the Colli Albani volcano, Italy

    Science.gov (United States)

    Trolese, Matteo; Giordano, Guido; Cifelli, Francesca; Winkler, Aldo; Mattei, Massimo

    2017-11-01

    Few studies have detailed the thermal architecture of large-volume pyroclastic density current deposits, although such work has a clear importance for understanding the dynamics of eruptions of this magnitude. Here we examine the temperature of emplacement of large-volume caldera-forming ignimbrites related to magmatic and phreatomagmatic eruptions at the Colli Albani volcano, Italy, by using thermal remanent magnetization analysis on both lithic and juvenile clasts. Results show that all the magmatic ignimbrites were deposited at high temperature, between the maximum blocking temperature of the magnetic carrier (600-630 °C) and the glass transition temperature (about 710 °C). Temperature estimations for the phreatomagmatic ignimbrite range between 200 and 400 °C, with most of the clasts emplaced between 200 and 320 °C. Because all the investigated ignimbrites, magmatic and phreatomagmatic, share similar magma composition, volume and mobility, we attribute the temperature difference to magma-water interaction, highlighting its pronounced impact on thermal dissipation, even in large-volume eruptions. The homogeneity of the deposit temperature of each ignimbrite across its areal extent, which is maintained across topographic barriers, suggests that these systems are thermodynamically isolated from the external environment for several tens of kilometers. Based on these findings, we propose that these large-volume ignimbrites are dominated by the mass flux, which forces the lateral transport of mass, momentum, and thermal energy for distances up to tens of kilometers away from the vent. We conclude that spatial variation of the emplacement temperature can be used as a proxy for determining the degree of forced-convection flow.

  12. A coupled nuclear reactor thermal energy storage system for enhanced load following operation

    International Nuclear Information System (INIS)

    Alameri, Saeed A.; King, Jeffrey C.

    2013-01-01

    Nuclear power plants operate most economically at a constant power level, providing base load electric power. In an energy grid containing a high fraction of renewable power sources, nuclear reactors may be subject to significantly variable power demands. These variable power demands can negatively impact the effective capacity factor of the reactor and result in severe economic penalties. Coupling a nuclear reactor to a large thermal energy storage block will allow the reactor to better respond to variable power demands. In the system described in this paper, a Prismatic core Advanced High Temperature Reactor supplies constant power to a lithium chloride molten salt thermal energy storage block that provides thermal power as needed to a closed Brayton cycle energy conversion system. During normal operation, the thermal energy storage block stores thermal energy during the night for use in the times of peak demand during the day. In this case, the nuclear reactor stays at a constant thermal power level. After a loss of forced circulation, the reactor reaches a shut down state in less than half an hour and the average fuel, graphite and coolant temperatures remain well within the design limits over the duration of the transient, demonstrating the inherent safety of the coupled system. (author)

  13. Thermal Analysis of a Thermal Energy Storage Unit to Enhance a Workshop Heating System Driven by Industrial Residual Water

    Directory of Open Access Journals (Sweden)

    Wenqiang Sun

    2017-02-01

    Full Text Available Various energy sources can be used for room heating, among which waste heat utilization has significantly improved in recent years. However, the majority of applicable waste heat resources are high-grade or stable thermal energy, while the low-grade or unstable waste heat resources, especially low-temperature industrial residual water (IRW, are insufficiently used. A thermal energy storage (TES unit with paraffin wax as a phase change material (PCM is designed to solve this problem in a pharmaceutical plant. The mathematical models are developed to simulate the heat storage and release processes of the TES unit. The crucial parameters in the recurrence formulae are determined: the phase change temperature range of the paraffin wax used is 47 to 56 °C, and the latent heat is 171.4 kJ/kg. Several thermal behaviors, such as the changes of melting radius, solidification radius, and fluid temperature, are simulated. In addition, the amount of heat transferred, the heat transfer rate, and the heat storage efficiency are discussed. It is presented that the medicine production unit could save 10.25% of energy consumption in the investigated application.

  14. Detailed partial load investigation of a thermal energy storage concept for solar thermal power plants with direct steam generation

    Science.gov (United States)

    Seitz, M.; Hübner, S.; Johnson, M.

    2016-05-01

    Direct steam generation enables the implementation of a higher steam temperature for parabolic trough concentrated solar power plants. This leads to much better cycle efficiencies and lower electricity generating costs. For a flexible and more economic operation of such a power plant, it is necessary to develop thermal energy storage systems for the extension of the production time of the power plant. In the case of steam as the heat transfer fluid, it is important to use a storage material that uses latent heat for the storage process. This leads to a minimum of exergy losses during the storage process. In the case of a concentrating solar power plant, superheated steam is needed during the discharging process. This steam cannot be superheated by the latent heat storage system. Therefore, a sensible molten salt storage system is used for this task. In contrast to the state-of-the-art thermal energy storages within the concentrating solar power area of application, a storage system for a direct steam generation plant consists of a latent and a sensible storage part. Thus far, no partial load behaviors of sensible and latent heat storage systems have been analyzed in detail. In this work, an optimized fin structure was developed in order to minimize the costs of the latent heat storage. A complete system simulation of the power plant process, including the solar field, power block and sensible and latent heat energy storage calculates the interaction between the solar field, the power block and the thermal energy storage system.

  15. Synthesis, performance and regeneration of carbon membranes for biogas upgrading - a future energy carrier

    Energy Technology Data Exchange (ETDEWEB)

    Lie, Jon Arvid

    2005-07-01

    was also seen on the surface of Ag-nitrate containing carbon. However, the Ag- and Cu-containing membranes showed a high H2 permeability. Adding metal oxides makes the carbon membranes retard the transport of easily condensable gases (e.g. CO2). This can be exploited for enhanced H2/CO{sub 2} separation efficiency. A simple, energy effective and rapid regeneration method for membranes that are conductors or semi-conductors has been developed: When a low voltage, direct current was applied on an iron-doped carbon, sorption of gases in the carbon decreased, while diffusivity increased to a larger degree, resulting in enhanced permeation rates. Electrothermal regeneration may also be applied online, and is especially suitable for separation in non-oxidizing atmospheres, like CO{sub 2}/CH{sub 4} separation. The method can be used for a continuous process, and not only for batchwise regeneration (e.g. activated carbon). The CO{sub 2} permeability increased with about 60%, while the CH{sub 4} permeability was unchanged (single gas tests). Mixed gas tests on the same type of iron-doped carbon (without current applied) resulted in a reduction of both the CO2 permeability and the selectivity, compared to single gas tests. High performance carbon membranes were also formed from the commercial polymer XP (cover name). The CO{sub 2}/CH{sub 4} selectivity was typically larger than 100, with a CO2 permeability of about 200 Barrer (single gas tests). The applied precursor film thickness was in the range 50-70 micron, and was found to be crucial for the carbonization process. Films of 100 microns or more resulted in cracks during carbonization, probably because of low gas drainage, and were rendered useless. Carbon membranes from XP possess two important advantages: 1) The films produced at 500 C have some degree of flexibility, hence easy to handle and process. Masking and testing these carbons were not challenging, when a proper precursor film thickness was used. 2) Aging seems not

  16. Non-Maxwellian characteristics of the energy distribution of ionosphere thermal electrons

    International Nuclear Information System (INIS)

    Amemiya, Hiroshi; Oyama, Koichiro; Hirao, Kunio.

    1985-01-01

    Observation of the energy distributions of thermal electrons are made in a lower mid-latitude ionosphere between 90 km and 220 km at dusk by an S-310-14 rocket on 18 h 16 m, Sept. 16, 1983. Measurements were based on the Druyvesteyn method using Langmuir probes. Between 108 and 160 km, bumps appeared on the high energy tail. The densities of such non-thermal electrons were of the order of 10 -2 of those of thermal electrons and the energy gap between the peaks of the non-thermal and thermal electrons was about 0.3 eV. On the other hand, above 170 km (F-layer), distributions had no bumps on the tail but deviated slightly from Maxwellian. The temperature of thermal electrons showed a gradual increase with height and became about 900 0 K in the F-laye. Mechanism of the appearance of the non-thermal electrons is considered to be due to super-elastic collisions between N 2 (v>0) and thermal electrons. (author)

  17. Grey-Box Based Optimal Control for Thermal Systems in Buildings - Unlocking Energy Efficiency and Flexibility

    OpenAIRE

    De Coninck, Roel

    2015-01-01

    Improving the energy efficiency of building energy systems is a key challenge for the mitigation of climate change. In particular, bad controlnbsp;operation often causes large energy efficiency losses, both in new and old buildings.nbsp;implementation of model predictive control (MPC) in buildings could enable an improved thermal comfort, lower operational costs and lower CO2 emissions. Moreover, such a controller can offer services to the energy market by using the flexibility of the buildin...

  18. Ground Thermal Inertia for Energy Efficient Building Design: A Case Study on Food Industry

    OpenAIRE

    Mazarrón, Fernando R.; Cid-Falceto, Jaime; Cañas, Ignacio

    2012-01-01

    The search for energy efficient construction solutions is still pending in the agro-food industry, in which a large amount of energy is often consumed unnecessarily when storing products. The main objective of this research is to promote high energy efficiency built environments, which aim to reduce energy consumption in this sector. We analyze the suitability of using the thermal inertia of the ground to provide an adequate environment for the storage and conservation of agro-food products. ...

  19. Carbon: Hydrogen Carrier or Disappearing Skeleton?

    NARCIS (Netherlands)

    Jong, K.P. de; Wechem, H.M.H. van

    1994-01-01

    The use of liquid hydrocarbons as energy carriers implies the use of carbon as a carrier for hydrogen to facilitate hydrogen transport and storage. The current trend for liquid energy carriers used in the transport sector is to maximize the load of hydrogen on the carbon carrier. The recently

  20. Design of a Protection Thermal Energy Storage Using Phase Change Material Coupled to a Solar Receiver

    Science.gov (United States)

    Verdier, D.; Falcoz, Q.; Ferrière, A.

    2014-12-01

    Thermal Energy Storage (TES) is the key for a stable electricity production in future Concentrated Solar Power (CSP) plants. This work presents a study on the thermal protection of the central receiver of CSP plant using a tower which is subject to considerable thermal stresses in case of cloudy events. The very high temperatures, 800 °C at design point, impose the use of special materials which are able to resist at high temperature and high mechanical constraints and high level of concentrated solar flux. In this paper we investigate a TES coupling a metallic matrix drilled with tubes of Phase Change Material (PCM) in order to store a large amount of thermal energy and release it in a short time. A numerical model is developed to optimize the arrangement of tubes into the TES. Then a methodology is given, based from the need in terms of thermal capacity, in order to help the choice of the geometry.

  1. Identifying possible non-thermal effects of radio frequency energy on inactivating food microorganisms.

    Science.gov (United States)

    Kou, Xiaoxi; Li, Rui; Hou, Lixia; Zhang, Lihui; Wang, Shaojin

    2018-03-23

    Radio frequency (RF) heating has been successfully used for inactivating microorganisms in agricultural and food products. Athermal (non-thermal) effects of RF energy on microorganisms have been frequently proposed in the literature, resulting in difficulties for developing effective thermal treatment protocols. The purpose of this study was to identify if the athermal inactivation of microorganisms existed during RF treatments. Escherichia coli and Staphylococcus aureus in apple juice and mashed potato were exposed to both RF and conventional thermal energies to compare their inactivation populations. A thermal death time (TDT) heating block system was used as conventional thermal energy source to simulate the same heating treatment conditions, involving heating temperature, heating rate and uniformity, of a RF treatment at a frequency of 27.12 MHz. Results showed that a similar and uniform temperature distribution in tested samples was achieved in both heating systems, so that the central sample temperature could be used as representative one for evaluating thermal inactivation of microorganisms. The survival patterns of two target microorganisms in two food samples were similar both for RF and heating block treatments since their absolute difference of survival populations was  0.05) in inactivating bacteria between the RF and the heating block treatments at each set of temperatures. The solid temperature and microbial inactivation data demonstrated that only thermal effect of RF energy at 27.12 MHz was observed on inactivating microorganisms in foods. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Analysis and sizing of thermal energy storage in combined heating, cooling and power plants for buildings

    International Nuclear Information System (INIS)

    Martínez-Lera, S.; Ballester, J.; Martínez-Lera, J.

    2013-01-01

    Highlights: ► Novel method to estimate the contribution of thermal energy storage in CHCP plants. ► Simple and accurate analysis of contributions of thermal storage. ► Application to the assessment and optimal sizing of thermal storage in CHCP plants. ► Thermal storage increases efficiency, coverage and economic benefit. ► Thermal storage allows increasing efficient operation of the plant. - Abstract: Thermal energy storage (TES) can lead to significant energy savings and economic benefits in combined heating, cooling and power plants (CHCPs) for buildings in the tertiary sector. However, their complex interactions with the rest of the CHCP system make their adequate sizing difficult without using extensive and detailed simulations. The authors have developed a new method to evaluate the thermal contribution of TES based on simple procedures. Comparisons with detailed simulations for a range of situations confirm the ability of this method to predict the effect of TES on CHCP systems with good approximation, as well as to find the optimal size in a relatively simple manner and with few required data. The case studies show a strong dependence of the TES contribution on the demands profile and the operation strategy. However, adequately sized TES are proven to bring relevant energy savings as well as economic profit to CHCP plants. In this paper, sizing procedures are provided to find the optimal volume both in terms of thermodynamic efficiency and of economic profit

  3. Contribution of thermal metrology to energy mastery; Apport de la metrologie thermique a la maitrise de l'energie

    Energy Technology Data Exchange (ETDEWEB)

    Degiovanni, A.; Remy, B. [Institut National Polytechnique de Lorraine, LEMTA - ENSEM, 54 - Vandoeuvre les Nancy (France)

    2005-07-01

    This paper defines, first, the field of thermal metrology, its history and recent advances (measurement of temperatures, of heat fluxes, of thermophysical data, at interfaces) and then uses several examples to show how thermal metrology can contribute to the conservation of energy: metrology of thermal diffusivities and conductivities of nuclear fuels, follow up of continuous steel casting, control of glass melters, combustion control in internal combustion engines, mass and heat transfers in fuel cells, forming of metal sheets, monitoring of heat flux in forest fires, characterization of insulating materials. (J.S.)

  4. Solar thermal power and photovoltaic energy are both developing

    International Nuclear Information System (INIS)

    Le Jannic, N.; Houot, G.

    2010-01-01

    Thermodynamic solar energy and photovoltaic energy are expected to reach together a quarter of the world electricity production by 2050. In France the development of thermodynamic solar plants is hampered by the high cost of land in the sunny regions. As for photovoltaic energy, France has the potentiality to become an important producer. Since 2006, the French government has supported photovoltaic energy by proposing incentive electricity purchase prices guaranteed for 20 years. In 2006, the Ines research institute was founded, one of its research fields is the development of high yield silicon cells. (A.C.)

  5. Preparation and characterization of nano-sized phase change emulsions as thermal energy storage and transport media

    International Nuclear Information System (INIS)

    Chen, J.; Zhang, P.

    2017-01-01

    Highlights: • The nano-sized phase change emulsions are prepared by using D-phase method. • The thermo-physical and transport properties are experimentally investigated. • The influence of surfactant on the melting temperature and latent heat of water is clarified. • The phase change emulsion can be used as the heat transfer fluid in a thermal energy storage system. - Abstract: Phase change emulsion (PCE) is a kind of two-phase heat transfer fluid with phase change material (PCM) dispersed in carrier fluid. It has received intensive attractions in recent years due to the fact that it can be used as both the thermal energy storage material and transport medium simultaneously in a thermal energy storage system. In the present study, nano-sized PCEs are prepared by the D-phase method with n-hexadecane and n-octadecane as PCMs. The thermo-physical and transport properties are characterized to facilitate the applications. The droplet size distribution of the PCE is measured by a Photon Correlation Spectroscopy, and the results show that the droplet size distributions are similar at different mass fractions. The rheological behavior and viscosity of the PCE are measured by a rheometer, which shows that the PCEs at mass fractions below 30.0 wt% are Newtonian fluids, and the viscosities are dependent on both the mass fraction and temperature. The differential scanning calorimetry (DSC) is employed to analyze the phase change characteristics of the PCE, and the results indicate large supercooling degree of water and PCM in the PCE. The melting temperature and latent heat of water in the PCE are much smaller than those of pure water. The thermal conductivities of the PCE with different mass fractions at different temperatures are measured by the transient hot-wire method. Furthermore, the energy transport characteristics of the PCEs are evaluated on the basis of the measured thermo-physical and transport properties. The results suggest that the PCEs show a drastic

  6. Economic and Environmental Considerations for Zero-emission Transport and Thermal Energy Generation on an Energy Autonomous Island

    Directory of Open Access Journals (Sweden)

    Fontina Petrakopoulou

    2018-01-01

    Full Text Available The high cost and environmental impact of fossil-fuel energy generation in remote regions can make renewable energy applications more competitive than business-as-usual scenarios. Furthermore, energy and transport are two of the main sectors that significantly contribute to global greenhouse gas emissions. This paper focuses on the generation of thermal energy and the transport sector of a fossil fuel-based energy independent island in Greece. We evaluate (1 technologies for fully renewable thermal energy generation using building-specific solar thermal systems and (2 the replacement of the vehicle fleet of the island with electric and hydrogen-fueled vehicles. The analysis, based on economic and environmental criteria, shows that although solar thermal decreases greenhouse gases by 83%, when compared to the current diesel-based situation, it only becomes economically attractive with subsidy scenarios equal to or higher than 50%. However, in the transport sector, the sum of fuel and maintenance costs of fuel-cell and electric vehicles is found to be 45% lower than that of the current fleet, due to their approximately seven times lower fuel cost. Lastly, it will take approximately six years of use of the new vehicles to balance out the emissions of their manufacturing phase.

  7. Feasibility study of a self-remediation system for mine drainage using its thermal energy

    Science.gov (United States)

    Oh, Chamteut; Cheong, Youngwook; Yim, Giljae; Ji, Sangwoo

    2016-04-01

    Mine drainage is defined as the water which is discharged to the ground surface through shafts and/or cracks formed by mining activities. Typically, mine drainage features high concentration of acidity and metals since it passes through the underground. Therefore, for the purpose of protecting the surrounding natural environment, mine drainage should be remediated before being discharged to nature. Mine drainage, due to its nature of being retained underground, shows constant temperature which is independent from the temperature of the atmosphere above ground. This condition allows mine drainage to become a promising renewable energy source since energy can be recovered from water with constant temperature. In this research, a self-remediation system is proposed which remediates the mine drainage through electrochemical reactions powered by the thermal energy of mine drainage. High energy efficiency is able to be achieved by shortening the distance between the energy source and consumption, and therefore, this system has a strong advantage to be actualized. A feasibility study for the system was conducted in this research where the thermal energy of mine drainage over time and depth was calculated as energy supply and the required electrical energy for remediating the mine drainage was measured as energy consumption. While the technology of converting thermal energy directly into electrical energy is yet to be developed, energy balance analysis results showed that the proposed self-remediation system is theoretically possible.

  8. Energy dashboard for real-time evaluation of a heat pump assisted solar thermal system

    Science.gov (United States)

    Lotz, David Allen

    The emergence of net-zero energy buildings, buildings that generate at least as much energy as they consume, has lead to greater use of renewable energy sources such as solar thermal energy. One example is a heat pump assisted solar thermal system, which uses solar thermal collectors with an electrical heat pump backup to supply space heating and domestic hot water. The complexity of such a system can be somewhat problematic for monitoring and maintaining a high level of performance. Therefore, an energy dashboard was developed to provide comprehensive and user friendly performance metrics for a solar heat pump system. Once developed, the energy dashboard was tested over a two-week period in order to determine the functionality of the dashboard program as well as the performance of the heating system itself. The results showed the importance of a user friendly display and how each metric could be used to better maintain and evaluate an energy system. In particular, Energy Factor (EF), which is the ratio of output energy (collected energy) to input energy (consumed energy), was a key metric for summarizing the performance of the heating system. Furthermore, the average EF of the solar heat pump system was 2.29, indicating an efficiency significantly higher than traditional electrical heating systems.

  9. Transient thermal behaviour of crumb rubber-modified concrete and implications for thermal response and energy efficiency in buildings

    International Nuclear Information System (INIS)

    Hall, Matthew R.; Najim, Khalid B.; Hopfe, Christina J.

    2012-01-01

    Experimental data is presented for the dry and saturated steady state thermo-physical properties, and also the dynamic thermal properties, of 180, 120 and 65 mm target slump mix designs for Plain Rubberised Concrete (PRC) with varying %wt rubber substitution and aggregate replacement types (fine, coarse, and mixed). The composites had significantly lower density and thermal conductivity than plain concrete, and there was an inverse relationship between thermal admittance and (a) mix design target slump, and (b) %wt crumb rubber substitution. The thermal decrement remained almost constant, and yet the associated time lag can be increased significantly. Parametric analysis of the effects of crumb rubber substitution for a heavyweight PassivHaus standard dwelling (in non-mechanical ventilation mode) was conducted using building performance simulation. For a London (warmer) or Glasgow (cooler) climate, PRC can be used at up to 30%wt addition and all replacement types as a substitute for plain concrete without causing any significant difference in Dry Resultant Temperature (DRT) fluctuation, if used in conjunction with passive ventilation for night time cooling. However, for the same material there was a general tendency to increase the number of overheating hours in this construction type due to its greater ability to retain any stored heat energy. - Highlights: ► PRC has significantly lower density and thermal conductivity than plain concrete. ► Inverse relationship between thermal admittance and %wt crumb rubber substitution. ► Thermal decrement almost constant but associated time lag increased significantly. ► Up to 30%wt rubber used without significant difference in DRT fluctuation.

  10. Thermal mass impact on energy performance of a low, medium and heavy mass building in Belgrade

    Directory of Open Access Journals (Sweden)

    Anđelković Bojan V.

    2012-01-01

    Full Text Available Heavy mass materials used in building structures and architecture can significantly affect building energy performance and occupant comfort. The purpose of this study was to investigate if thermal mass can improve the internal environment of a building, resulting in lower energy requirements from the mechanical systems. The study was focused on passive building energy performance and compared annual space heating and cooling energy requirements for an office building in Belgrade with several different applications of thermal mass. A three-dimensional building model was generated to represent a typical office building. Building shape, orientation, glazing to wall ratio, envelope insulation thickness, and indoor design conditions were held constant while location and thickness of building mass (concrete was varied between cases in a series of energy simulations. The results were compared and discussed in terms of the building space heating and cooling energy and demand affected by thermal mass. The simulation results indicated that with addition of thermal mass to the building envelope and structure: 100% of all simulated cases experienced reduced annual space heating energy requirements, 67% of all simulated cases experienced reduced annual space cooling energy requirements, 83% of all simulated cases experienced reduced peak space heating demand and 50% of all simulated cases experienced reduced peak space cooling demand. The study demonstrated that there exists a potential for reducing space heating and cooling energy requirements with heavy mass construction in the analyzed climate region (Belgrade, Serbia.

  11. Thermal modelling of borehole heat exchangers and borehole thermal energy stores; Zur thermischen Modellierung von Erdwaermesonden und Erdsonden-Waermespeichern

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Dan

    2011-07-15

    The thermal use of the underground for heating and cooling applications can be done with borehole heat exchangers. This work deals with the further development of the modelling of thermal transport processes inside and outside the borehole as well as with the application of the further developed models. The combination of high accuracy and short computation time is achieved by the development of three-dimensional thermal resistance and capacity models for borehole heat exchangers. Short transient transport processes can be calculated by the developed model with a considerable higher dynamic and accuracy than with known models from literature. The model is used to evaluate measurement data of a thermal response test by parameter estimation technique with a transient three-dimensional model for the first time. Clear advantages like shortening of the test duration are shown. The developed borehole heat exchanger model is combined with a three-dimensional description of the underground in the Finite-Element-Program FEFLOW. The influence of moving groundwater on borehole heat exchangers and borehole thermal energy stores is then quantified.

  12. Thermal Characteristics of New Building Materials and their Effect upon the Energy Efficiency

    Science.gov (United States)

    Ekmanis, J.; Zebergs, V.; Zeltins, N.; Vrublevski, V.

    2008-09-01

    The paper formulates the role of thermal inertia of the building materials in the energy supply of buildings and in solution of the energy efficiency problems. The evolution of construction entails the application of new building materials as well as of glazed surfaces in the envelopes of buildings. An analysis is made of the influence of the thermal resistance of building materials and their heat capacity on the thermal inertia indicators of buildings. An inertia scale of buildings has been developed for the choice of the heat supply capacities of buildings at low outdoor temperatures under extreme conditions of the Latvian climate. The ratio of the ventilation capacities has been analysed in the total heating balance at a low thermal inertia of buildings. The significance of innovative ventilation technologies for raising the energy efficiency has been considered.

  13. Energy improvement of a conventional dwelling in Argentina through thermal simulation

    Energy Technology Data Exchange (ETDEWEB)

    Filippin, C. [CONICET-CC302, Santa Rosa 6300, La Pampa (Argentina); Flores Larsen, S. [INENCO-Instituto de Investigaciones en Energias No Convencionales, Universidad Nacional de Salta, CONICET, Avda. Bolivia 5150, CP 4400 Salta Capital (Argentina); Lopez Gay, E.

    2008-10-15

    This paper analyses the design, technology, thermal behaviour, and energy consumption of both a conventional and a refurbished dwelling located in a region with a temperate-cold climate in central Argentina. The thermal behaviour and the energy consumption of the conventional building were monitored during winter. The experimental data were analysed and included in a simulation of the transient thermal behaviour of the house. Measurements and simulation were in agreement, showing a mean deviation below 0.5{sup o}C. To reduce the heating and cooling loads, the dwelling was refurbished and its thermal behaviour was studied through a computer simulation, for the critical seasons (winter and summer) and for two occupancy schedules (with and without inhabitants). The refurbishment included passive solar heating, shading, and an insulated envelope. These successful changes allowed energy savings of 66% and 52% for winter and summer, respectively. (author)

  14. Investigation of the thermal hazardous effect of protective clothing caused by stored energy discharge.

    Science.gov (United States)

    He, Jiazhen; Lu, Yehu; Chen, Yan; Li, Jun

    2017-09-15

    In addition to direct thermal energy from a heating source, a large amount of thermal energy stored in clothing will continuously discharge to skin after exposure. Investigating the thermal hazardous effect of clothing caused by stored energy discharge is crucial for the reliability of thermal protective clothing. In this study several indices were proposed and applied to evaluate the impact of thermal energy discharge on human skin. The heat discharge from different layers of fabric systems was investigated, and the influences of air gaps and applied compression were examined. Heat fluxes at the boundaries of fabric layers and the distribution of heat discharge were determined. Additionally, the correlation between heat storage during exposure and heat discharge after exposure was identified. The results demonstrated that heat discharge to the skin could be correlated with heat storage within the fabric, however, it highly depended on the air gap under clothing, the applied compression, and the insulation provided by the fabric layers. Results from this study could contribute to thoroughly understanding the thermal hazardous effect of clothing and enhance the technical basis for developing new fabric combinations to minimize energy discharge after exposure. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Community biomass handbook. Volume I: thermal wood energy

    Science.gov (United States)

    D. Becker; E. Lowell; D. Bihn; R. Anderson; S. Taff

    2014-01-01

    This handbook and financial app is a guide to help communities quickly determine if biomass energy projects might work for them so that this option is not overlooked. Its purpose is as a screening tool designed to save significant time, resources, and investment by weeding out those wood energy projects that may never come to fruition from those that have a chance of...

  16. Peak-load pricing and thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    1979-01-01

    Twenty papers were presented at the meeting. A separate abstract was prepared for each of 19 papers. One paper was processed previously for the Energy Data Base (EDB). Fifteen of the papers were processed for inclusion in Energy Abstracts for Policy Analysis (EAPA). (LCL)

  17. A thermally regenerative ammonia-based battery for efficient harvesting of low-grade thermal energy as electrical power

    KAUST Repository

    Zhang, Fang

    2015-01-01

    © 2015 The Royal Society of Chemistry. Thermal energy was shown to be efficiently converted into electrical power in a thermally regenerative ammonia-based battery (TRAB) using copper-based redox couples [Cu(NH3)4 2+/Cu and Cu(ii)/Cu]. Ammonia addition to the anolyte (2 M ammonia in a copper-nitrate electrolyte) of a single TRAB cell produced a maximum power density of 115 ± 1 W m-2 (based on projected area of a single copper mesh electrode), with an energy density of 453 W h m-3 (normalized to the total electrolyte volume, under maximum power production conditions). Adding a second cell doubled both the voltage and maximum power. Increasing the anolyte ammonia concentration to 3 M further improved the maximum power density to 136 ± 3 W m-2. Volatilization of ammonia from the spent anolyte by heating (simulating distillation), and re-addition of this ammonia to the spent catholyte chamber with subsequent operation of this chamber as the anode (to regenerate copper on the other electrode), produced a maximum power density of 60 ± 3 W m-2, with an average discharge energy efficiency of ∼29% (electrical energy captured versus chemical energy in the starting solutions). Power was restored to 126 ± 5 W m-2 through acid addition to the regenerated catholyte to decrease pH and dissolve Cu(OH)2 precipitates, suggesting that an inexpensive acid or a waste acid could be used to improve performance. These results demonstrated that TRABs using ammonia-based electrolytes and inexpensive copper electrodes can provide a practical method for efficient conversion of low-grade thermal energy into electricity.

  18. Economic Dispatch for Power System Included Wind and Solar Thermal Energy

    Directory of Open Access Journals (Sweden)

    Saoussen BRINI

    2009-07-01

    Full Text Available With the fast development of technologies of alternative energy, the electric power network can be composed of several renewable energy resources. The energy resources have various characteristics in terms of operational costs and reliability. In this study, the problem is the Economic Environmental Dispatching (EED of hybrid power system including wind and solar thermal energies. Renewable energy resources depend on the data of the climate such as the wind speed for wind energy, solar radiation and the temperature for solar thermal energy. In this article it proposes a methodology to solve this problem. The resolution takes account of the fuel costs and reducing of the emissions of the polluting gases. The resolution is done by the Strength Pareto Evolutionary Algorithm (SPEA method and the simulations have been made on an IEEE network test (30 nodes, 8 machines and 41 lines.

  19. Thermal energy storage – overview and specific insight into nitrate salts for sensible and latent heat storage

    Directory of Open Access Journals (Sweden)

    Nicole Pfleger

    2015-07-01

    Full Text Available Thermal energy storage (TES is capable to reduce the demand of conventional energy sources for two reasons: First, they prevent the mismatch between the energy supply and the power demand when generating electricity from renewable energy sources. Second, utilization of waste heat in industrial processes by thermal energy storage reduces the final energy consumption. This review focuses mainly on material aspects of alkali nitrate salts. They include thermal properties, thermal decomposition processes as well as a new method to develop optimized salt systems.

  20. Thermal energy storage – overview and specific insight into nitrate salts for sensible and latent heat storage

    Science.gov (United States)

    Bauer, Thomas; Martin, Claudia; Eck, Markus; Wörner, Antje

    2015-01-01

    Summary Thermal energy storage (TES) is capable to reduce the demand of conventional energy sources for two reasons: First, they prevent the mismatch between the energy supply and the power demand when generating electricity from renewable energy sources. Second, utilization of waste heat in industrial processes by thermal energy storage reduces the final energy consumption. This review focuses mainly on material aspects of alkali nitrate salts. They include thermal properties, thermal decomposition processes as well as a new method to develop optimized salt systems. PMID:26199853