WorldWideScience

Sample records for hybrid photovoltaic-solar thermal

  1. Photovoltaic solar panel for a hybrid PV/thermal system

    Energy Technology Data Exchange (ETDEWEB)

    Zakharchenko, R.; Licea-Jimenez, L.; Perez-Garcia, S.A.; Perez-Robles, J.F.; Gonzalez-Hernandez, J.; Vorobiev, Y. [CINVESTAV-Queretaro, (Mexico); Vorobiev, P. [Universidad Autonoma de Queretaro, (Mexico). Facultad de Ingenieria; Dehesa-Carrasco, U. [Instituto Tec. Del Istmo, Oaxaco (Mexico). Dep. de Ingenieria Electromecanica

    2004-05-01

    The hybrid PV-thermal system was studied, with the photovoltaic panel (PVP) area much smaller than that of the solar collector. Performance of the different panels in the system was investigated, in particular, those made of crystalline (c-) Si, {alpha}-Si and CuInSe{sub 2} as well as different materials and constructions for the thermal contact between the panel and the collector. Our conclusion is that the PVP for application in a hybrid system needs a special design providing efficient heat extraction from it. PVP was designed and made. Its study has shown that this design provides the high electrical and thermal efficiency of the hybrid system. (author)

  2. Photovoltaic. Solar thermal. Solar thermal electricity

    International Nuclear Information System (INIS)

    2009-01-01

    The year 2008 was excellent for solar energy in the European Union. The growth of the installed capacity for photovoltaic was +159% (it means +4747.018 MW) to reach 9689.952 MW and that for solar thermal was +51.5% (it means +3172.5 MW) to reach 19982.7 MW. Worldwide concentrated solar thermal capacity stood at 679 MW in 2009, while this figure may seem low, the sector has a promising future ahead of it. (A.C.)

  3. Thermal photovoltaic solar integrated system analysis using neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Ashhab, S. [Hashemite Univ., Zarqa (Jordan). Dept. of Mechanical Engineering

    2007-07-01

    The energy demand in Jordan is primarily met by petroleum products. As such, the development of renewable energy systems is quite attractive. In particular, solar energy is a promising renewable energy source in Jordan and has been used for food canning, paper production, air-conditioning and sterilization. Artificial neural networks (ANNs) have received significant attention due to their capabilities in forecasting, modelling of complex nonlinear systems and control. ANNs have been used for forecasting solar energy. This paper presented a study that examined a thermal photovoltaic solar integrated system that was built in Jordan. Historical input-output system data that was collected experimentally was used to train an ANN that predicted the collector, PV module, pump and total efficiencies. The model predicted the efficiencies well and can therefore be utilized to find the operating conditions of the system that will produce the maximum system efficiencies. The paper provided a description of the photovoltaic solar system including equations for PV module efficiency; pump efficiency; and total efficiency. The paper also presented data relevant to the system performance and neural networks. The results of a neural net model were also presented based on the thermal PV solar integrated system data that was collected. It was concluded that the neural net model of the thermal photovoltaic solar integrated system set the background for achieving the best system performance. 10 refs., 6 figs.

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

    International Nuclear Information System (INIS)

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

    2017-01-01

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

  5. Simulation of Hybrid Photovoltaic Solar Assisted Loop Heat Pipe/Heat Pump System

    Directory of Open Access Journals (Sweden)

    Nannan Dai

    2017-02-01

    Full Text Available A hybrid photovoltaic solar assisted loop heat pipe/heat pump (PV-SALHP/HP water heater system has been developed and numerically studied. The system is the combination of loop heat pipe (LHP mode and heat pump (HP mode, and the two modes can be run separately or compositely according to the weather conditions. The performances of independent heat pump (HP mode and hybrid loop heat pipe/heat pump (LHP/HP mode were simulated and compared. Simulation results showed that on typical sunny days in spring or autumn, using LHP/HP mode could save 40.6% power consumption than HP mode. In addition, the optimal switchover from LHP mode to HP mode was analyzed in different weather conditions for energy saving and the all-year round operating performances of the system were also simulated. The simulation results showed that hybrid LHP/HP mode should be utilized to save electricity on sunny days from March to November and the system can rely on LHP mode alone without any power consumption in July and August. When solar radiation and ambient temperature are low in winter, HP mode should be used

  6. A Hybrid Multiple-Criteria Decision-Making Approach for Photovoltaic Solar Plant Location Selection

    Directory of Open Access Journals (Sweden)

    Amy H. I. Lee

    2017-01-01

    Full Text Available Due to decaying fossil resource and increasing environmental consciousness, the demand of renewable energy resources is escalating these days. Photovoltaic solar energy is one of the most popular renewable energy resources in places where sunlight is abundant. The selection of a desirable location for constructing a photovoltaic solar plant is the first and one of the most important stages in the plant construction to provide a long-term energy production. In this paper, a comprehensive multiple-criteria decision-making model, which incorporates the interpretive structural modeling (ISM, fuzzy analytic network process (FANP and VIKOR (VlseKriterijumska OptimizacijaI Kompromisno Resenje in Serbian,meaning multi-criteria optimization and compromise solution, is proposed to select the most suitable photovoltaic solar plant location. The ISM is applied first to determine the interrelationships among the criteria and among the sub-criteria,andtheresults are used to construct a decision-making network. The FANP is applied next to solve the network and to calculate the importance weights of the sub-criteria. Finally, the VIKOR is adopted to determine the ranking of the photovoltaic solar plant locations. The proposed model is applied in a case study in evaluating photovoltaic solar plant locations in Taiwan. By applying the proposed model, decision makers can have a better thinking process and make more appropriate decisions justifiably.

  7. Photovoltaic solar concentrator

    Science.gov (United States)

    Nielson, Gregory N.; Cruz-Campa, Jose Luis; Okandan, Murat; Resnick, Paul J.; Sanchez, Carlos Anthony; Clews, Peggy J.; Gupta, Vipin P.

    2015-09-08

    A process including forming a photovoltaic solar cell on a substrate, the photovoltaic solar cell comprising an anchor positioned between the photovoltaic solar cell and the substrate to suspend the photovoltaic solar cell from the substrate. A surface of the photovoltaic solar cell opposite the substrate is attached to a receiving substrate. The receiving substrate may be bonded to the photovoltaic solar cell using an adhesive force or a metal connecting member. The photovoltaic solar cell is then detached from the substrate by lifting the receiving substrate having the photovoltaic solar cell attached thereto and severing the anchor connecting the photovoltaic solar cell to the substrate. Depending upon the type of receiving substrate used, the photovoltaic solar cell may be removed from the receiving substrate or remain on the receiving substrate for use in the final product.

  8. Thermal and photovoltaic solar system in Urban hotel; Sistema solar termico y fotovoltaico en hotel urbano

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, J.; Perpinan, O.; Ramirez, F.; Eyras, R.; Vega, J.

    2004-07-01

    The article describes the Solar Energy installations that are being carried out in the Hotel Monte Malaga promoted by the Gabriel Rojas Group. We can consider this project to be pioneer in Spain since it uses Photovoltaic Solar Panels as parasols in facades in order to reduce its frozen load and with the intention of producing electric energy that will be injected to the grid. In addition, solar collectors over roof are being used distributed in a totally integrated way with the building for the preheating of the sanitary hot water producing a saving of around 90% of the natural gas consume. This entire project is carried out in an ultramodern design using different bioclimatic techniques that turns this building into a singular one. (Author)

  9. Photovoltaic. Solar thermal. Solar thermal electricity;Le Photovoltaique. Le solaire thermique. L'heliothermodynamique

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    The year 2008 was excellent for solar energy in the European Union. The growth of the installed capacity for photovoltaic was +159% (it means +4747.018 MW) to reach 9689.952 MW and that for solar thermal was +51.5% (it means +3172.5 MW) to reach 19982.7 MW. Worldwide concentrated solar thermal capacity stood at 679 MW in 2009, while this figure may seem low, the sector has a promising future ahead of it. (A.C.)

  10. MoO3 Thickness, Thermal Annealing and Solvent Annealing Effects on Inverted and Direct Polymer Photovoltaic Solar Cells

    Directory of Open Access Journals (Sweden)

    Guillaume Wantz

    2012-11-01

    Full Text Available Several parameters of the fabrication process of inverted polymer bulk heterojunction solar cells based on titanium oxide as an electron selective layer and molybdenum oxide as a hole selective layer were tested in order to achieve efficient organic photovoltaic solar cells. Thermal annealing treatment is a common process to achieve optimum morphology, but it proved to be damageable for the performance of this kind of inverted solar cells. We demonstrate using Auger analysis combined with argon etching that diffusion of species occurs from the MoO3/Ag top layers into the active layer upon thermal annealing. In order to achieve efficient devices, the morphology of the bulk heterojunction was then manipulated using the solvent annealing technique as an alternative to thermal annealing. The influence of the MoO3 thickness was studied on inverted, as well as direct, structure. It appeared that only 1 nm-thick MoO3 is enough to exhibit highly efficient devices (PCE = 3.8% and that increasing the thickness up to 15 nm does not change the device performance. 

  11. Photovoltaic solar cell

    Science.gov (United States)

    Nielson, Gregory N; Okandan, Murat; Cruz-Campa, Jose Luis; Resnick, Paul J

    2013-11-26

    A photovoltaic solar cell for generating electricity from sunlight is disclosed. The photovoltaic solar cell comprises a plurality of spaced-apart point contact junctions formed in a semiconductor body to receive the sunlight and generate the electicity therefrom, the plurality of spaced-apart point contact junctions having a first plurality of regions having a first doping type and a second plurality of regions having a second doping type. In addition, the photovoltaic solar cell comprises a first electrical contact electrically connected to each of the first plurality of regions and a second electrical contact electrically connected to each of the second plurality of regions, as well as a passivation layer covering major surfaces and sidewalls of the photovoltaic solar cell.

  12. Predicting the performance of amorphous and crystalline silicon based photovoltaic solar thermal collectors

    International Nuclear Information System (INIS)

    Daghigh, Ronak; Ibrahim, Adnan; Jin, Goh Li; Ruslan, Mohd Hafidz; Sopian, Kamaruzzaman

    2011-01-01

    BIPVT is an application where solar PV/T modules are integrated into the building structure. System design parameters such as thermal conductivity and fin efficiency, type of cells, type of coolant and operating conditions are factors which influence the performance of BIPVT. Attempts have been made to improve the efficiency of building-integrated photovoltaic thermal (BIPVT). A new design concept of water-based PVT collector for building-integrated applications has been designed and evaluated. The results of simulation study of amorphous silicon (a-Si) PV/T and crystalline silicon (c-Si) module types are based on the metrological condition of Malaysia for a typical day in March. At a flow rate of 0.02 kg/s, solar radiation level between 700 and 900 W/m 2 and ambient temperature between 22 and 32 o C, the electrical, thermal and combined photovoltaic thermal efficiencies for the PV/T (a-Si) were 4.9%, 72% and 77%, respectively. Moreover, the electrical, thermal and combined photovoltaic thermal efficiencies of the PV/T (c-Si) were 11.6%, 51% and 63%.

  13. Graphene-enhanced thermal interface materials for heat removal from photovoltaic solar cells

    Science.gov (United States)

    Saadah, M.; Gamalath, D.; Hernandez, E.; Balandin, A. A.

    2016-09-01

    The increase in the temperature of photovoltaic (PV) solar cells affects negatively their power conversion efficiency and decreases their lifetime. The negative effects are particularly pronounced in concentrator solar cells. Therefore, it is crucial to limit the PV cell temperature by effectively removing the excess heat. Conventional thermal phase change materials (PCMs) and thermal interface materials (TIMs) do not possess the thermal conductivity values sufficient for thermal management of the next generation of PV cells. In this paper, we report the results of investigation of the increased efficiency of PV cells with the use of graphene-enhanced TIMs. Graphene reveals the highest values of the intrinsic thermal conductivity. It was also shown that the thermal conductivity of composites can be increased via utilization of graphene fillers. We prepared TIMs with up to 6% of graphene designed specifically for PV cell application. The solar cells were tested using the solar simulation module. It was found that the drop in the output voltage of the solar panel under two-sun concentrated illumination can be reduced from 19% to 6% when grapheneenhanced TIMs are used. The proposed method can recover up to 75% of the power loss in solar cells.

  14. Evaluation of thermal and photovoltaic solar systems in agricultural production units, Northern Huetar Region, Costa Rica

    Directory of Open Access Journals (Sweden)

    Tomás de Jesús Guzmán Hernández

    2017-09-01

    Full Text Available The dependence on fossil fuels urges society to seek for clean energy alternatives, in order to mitigate the effects of climate change. The objective of this study was to determine the potential of solar energy used for water heating and electricity generation. The study was conducted at the dairy of the Technology Institute of Costa Rica, San Carlos Headquarter, from May 15 to April 2016. The data related to the amount of the electricity produced and the temperature reached by water was obtained from the installed photovoltaic and thermal systems, the data was recorded by a computerized register. The obtained information about electricity production allowed researchers to calculate the amount of carbon dioxide equivalent that was not emitted into the atmosphere, and also the acquired economic saving on consumption. The use of these systems allowed the production unit have a self- sufficient source of electrical energy percentage, actually around 30 to 40% of the total electrical consumption. According to the energy production, the solar thermal system was capable to increase water temperature between 20 to 37 °C, temperature that represents more than 70% of the energy needed in order to reach the required water temperature (70 °C for cleaning and sanitizing the milking equipment, and also an economical saving around $90 per month was achieved. The results showed that these systems allow to improve the economical and productive efficiency of agricultural production units in the Northern Huetar Region of Costa Rica.

  15. Photovoltaic solar energy conversion

    CERN Document Server

    Bauer, Gottfried H

    2015-01-01

    This concise primer on photovoltaic solar energy conversion invites readers to reflect on the conversion of solar light into energy at the most fundamental level and encourages newcomers to the field to help find meaningful answers on how photovoltaic solar energy conversion can work (better), eventually contributing to its ongoing advancement. The book is based on lectures given to graduate students in the Physics Department at the University of Oldenburg over the last two decades, yet also provides an easy-to-follow introduction for doctoral and postdoctoral students from related disciplines such as the materials sciences and electrical engineering. Inspired by classic textbooks in the field, it reflects the author’s own ideas on how to understand, visualize and eventually teach the microscopic physical mechanisms and effects, while keeping the text as concise as possible so as to introduce interested readers to the field and balancing essential knowledge with open questions.

  16. Photovoltaic Solar Energy

    International Nuclear Information System (INIS)

    Gonzalez N, J.C.; Leal C, H.

    1998-01-01

    A short historical review of the technological advances; the current state and the perspectives of the materials for photovoltaic applications is made. Thereinafter, the general aspects of the physical principles and fundamental parameters that govern the operation of the solar cells are described. To way of the example, a methodology for the design and facilities size of a photovoltaic system is applied. Finally, the perspectives of photovoltaic solar energy in relationship to the market and political of development are mentioned

  17. Photovoltaic solar cell

    Science.gov (United States)

    Nielson, Gregory N.; Gupta, Vipin P.; Okandan, Murat; Watts, Michael R.

    2015-09-08

    A photovoltaic solar concentrator is disclosed with one or more transverse-junction solar cells (also termed point contact solar cells) and a lens located above each solar cell to concentrate sunlight onto the solar cell to generate electricity. Piezoelectric actuators tilt or translate each lens to track the sun using a feedback-control circuit which senses the electricity generated by one or more of the solar cells. The piezoelectric actuators can be coupled through a displacement-multiplier linkage to provide an increased range of movement of each lens. Each lens in the solar concentrator can be supported on a frame (also termed a tilt plate) having three legs, with the movement of the legs being controlled by the piezoelectric actuators.

  18. Photovoltaic solar concentrator

    Science.gov (United States)

    Nielson, Gregory N.; Gupta, Vipin P.; Okandan, Murat; Watts, Michael R.

    2016-03-15

    A photovoltaic solar concentrator is disclosed with one or more transverse-junction solar cells (also termed point contact solar cells) and a lens located above each solar cell to concentrate sunlight onto the solar cell to generate electricity. Piezoelectric actuators tilt or translate each lens to track the sun using a feedback-control circuit which senses the electricity generated by one or more of the solar cells. The piezoelectric actuators can be coupled through a displacement-multiplier linkage to provide an increased range of movement of each lens. Each lens in the solar concentrator can be supported on a frame (also termed a tilt plate) having three legs, with the movement of the legs being controlled by the piezoelectric actuators.

  19. Economical and environmental analysis of thermal and photovoltaic solar energy as source of heat for industrial processes

    Science.gov (United States)

    Pérez-Aparicio, Elena; Lillo-Bravo, Isidoro; Moreno-Tejera, Sara; Silva-Pérez, Manuel

    2017-06-01

    Thermal energy for industrial processes can be generated using thermal (ST) or photovoltaic (PV) solar energy. ST energy has traditionally been the most favorable option due to its cost and efficiency. Current costs and efficiencies values make the PV solar energy become an alternative to ST energy as supplier of industrial process heat. The aim of this study is to provide a useful tool to decide in each case which option is economically and environmentally the most suitable alternative. The methodology used to compare ST and PV systems is based on the calculation of the levelized cost of energy (LCOE) and greenhouse gas emissions (GHG) avoided by using renewable technologies instead of conventional sources of energy. In both cases, these calculations depend on costs and efficiencies associated with ST or PV systems and the conversion factor from thermal or electrical energy to GHG. To make these calculations, a series of hypotheses are assumed related to consumer and energy prices, operation, maintenance and replacement costs, lifetime of the system or working temperature of the industrial process. This study applies the methodology at five different sites which have been selected taking into account their radiometric and meteorological characteristics. In the case of ST energy three technologies are taken into account, compound parabolic concentrator (CPC), linear Fresnel collector (LFC) and parabolic trough collector (PTC). The PV option includes two ways of use of generated electricity, an electrical resistance or a combination of an electrical resistance and a heat pump (HP). Current values of costs and efficiencies make ST system remains as the most favorable option. These parameters may vary significantly over time. The evolution of these parameters may convert PV systems into the most favorable option for particular applications.

  20. Performance Evaluation of Photovoltaic Solar Air Conditioning

    Directory of Open Access Journals (Sweden)

    Snegirjovs A.

    2016-12-01

    Full Text Available Information on the electrical-driven solar air conditioning (SAC is rather scanty. A considerable body of technical data mostly concerns large-scale photo-voltaic solar air conditioning (PV-SAC systems. Reliable information about the energy output has arisen only in recent years; however, it is still not easily accessible, and sometimes its sources are closed. Despite these facts, solar energy researchers, observers and designers devote special attention to this type of SAC systems. In this study, performance evaluation is performed for the PV-SAC technology, in which low-power (up to 15 kWp of cooling power on average systems are used. Such a system contains a PV electric-driven compression chiller with cold and heat sensible thermal storage capacities, and a rejected energy unit used for preheating domestic hot water (DHW. In a non-cooling season, it is possible to partly employ the system in the reverse mode for DHW production. In this mode, the ambient air serves as a heat source. Besides, free cooling is integrated in the PV-SAC concept.

  1. Performance Evaluation of Photovoltaic Solar Air Conditioning

    Science.gov (United States)

    Snegirjovs, A.; Shipkovs, P.; Lebedeva, K.; Kashkarova, G.; Migla, L.; Gantenbein, P.; Omlin, L.

    2016-12-01

    Information on the electrical-driven solar air conditioning (SAC) is rather scanty. A considerable body of technical data mostly concerns large-scale photo-voltaic solar air conditioning (PV-SAC) systems. Reliable information about the energy output has arisen only in recent years; however, it is still not easily accessible, and sometimes its sources are closed. Despite these facts, solar energy researchers, observers and designers devote special attention to this type of SAC systems. In this study, performance evaluation is performed for the PV-SAC technology, in which low-power (up to 15 kWp of cooling power on average) systems are used. Such a system contains a PV electric-driven compression chiller with cold and heat sensible thermal storage capacities, and a rejected energy unit used for preheating domestic hot water (DHW). In a non-cooling season, it is possible to partly employ the system in the reverse mode for DHW production. In this mode, the ambient air serves as a heat source. Besides, free cooling is integrated in the PV-SAC concept.

  2. Photovoltaic Solar Energy : From Fundamentals to Applications

    NARCIS (Netherlands)

    Reinders, Angelina H.M.E.; Verlinden, P.J.; van Sark, W.G.J.H.M.; Freundlich, A.

    2016-01-01

    Solar PV is now the third most important renewable energy source, after hydro and wind power, in terms of global installed capacity. Bringing together the expertise of international PV specialists Photovoltaic Solar Energy: From Fundamentals to Applications provides a comprehensive and up-to-date

  3. Photovoltaic solar energy; Photovoltaische Solarenergie

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    for a renewable power supply? (G. Bopp); (17) Electrochemical energy storage for a stationary intermediate storage - Concepts and perspectives (M. Wohlfahrt-Mehrens); (18) Decentral photovoltaics: Autonomy, own consumption and grid relief by means of local power and heat storage systems (J. Binder); (19) Maximization of the lifetime of electric batteries in PV systems by means of battery hybrid storage systems (V. Spaeth); (20) Possibilities for grid integration of a high amount of photovoltaic power plants in the area of low performance (G. Wirth); (21) Change of load of grid components at the implementation of photovoltaic power into the power distribution system (G. Herold); (22) Feeding management and limitation of the supply of the active power to 70 % according to the new EEG 2012 (A. Umland); (23) Power quality and dynamic grid support: Do the medium voltage regulations correspond to the properties of PV inverters? (G. Doetter); (24) Perspectives of wafer based solar modules, technology and costs (R. Brendel); (25) Why is solar power not climate neutral but still environmentally friendly? Actual ecobalances to photovoltaics (M. Stucki); (26) Are photovoltaic power plants ''highly dangerous''? (H. Laukamp); (27) Power-to-Gas - Storage of renewable energies in the natural gas distribution system (M. Specht); (28) Utilization of own photovoltaic power - Fluctuation of radiation and load (B. Wille-Haussmann); (29) Arc detection in photovoltaic power plants - A system comparison between USA and Europe (A. Haeing); (30) 20 years 1,000 roofs program - Long-term experiences from Saxonia (M. Reiner); (31) Quality assurance of PV inverters - 20 years of field experiences with photovoltaic power plants in grid interconnection (J. Laschinski); (32) Experiences with the installation and operation of photovoltaic storage systems: Field tests of Sol-ion systems in southern Germany, Guadeloupe, Martinique and at research institutes (H.-D. Mohring); (33) Do

  4. Experimental study of a photovoltaic solar-assisted heat-pump/heat-pipe system

    International Nuclear Information System (INIS)

    Fu, H.D.; Pei, G.; Ji, J.; Long, H.; Zhang, T.; Chow, T.T.

    2012-01-01

    A practical design for a heat pump with heat-pipe photovoltaic/thermal (PV/T) collectors is presented. The hybrid system is called the photovoltaic solar-assisted heat-pump/heat-pipe (PV-SAHP/HP) system. To focus on both actual demand and energy savings, the PV-SAHP/HP system was designed to be capable of operating in three different modes, namely, the heat-pipe, solar-assisted heat pump, and air-source heat-pump modes. Based on solar radiation, the system operates in an optimal mode. A series of experiments were conducted in Hong Kong to study the performance of the system when operating in the heat-pipe and the solar-assisted heat-pump modes. Moreover, energy and exergy analyses were used to investigate the total PV/T performance of the system. - Highlights: ► A novel PV-SAHP/HP system with three different operating modes was proposed. ► Performance of the PV-SAHP/HP system was studied experimentally. ► A optimal operating mode of the PV-SAHP/HP system was suggested in this paper.

  5. Flexible thermal cycle test equipment for concentrator solar cells

    Science.gov (United States)

    Hebert, Peter H [Glendale, CA; Brandt, Randolph J [Palmdale, CA

    2012-06-19

    A system and method for performing thermal stress testing of photovoltaic solar cells is presented. The system and method allows rapid testing of photovoltaic solar cells under controllable thermal conditions. The system and method presents a means of rapidly applying thermal stresses to one or more photovoltaic solar cells in a consistent and repeatable manner.

  6. Photovoltaic solar energy. Proceedings; Photovoltaische Solarenergie. Tagungsband

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    Within the 21st symposium 'Photovoltaic Solar Energy' of the Ostbayerisches Technologie-Transfer-Institut e.V. (Regensburg, Federal Republic of Germany) at Banz Monastery (Bad Staffelstein, Federal Republic of Germany) between 8th and 10th March, 2006, the following lessons were held: (1) Basic conditions for a market support programme in the European context (EEG) (Winfried Hoffmann); (2) Actual developments in the German market of photovoltaics (Gerhard Stryi-Hipp); (3) Become a part of the global economic survey of Task 2 ''PV cost over time'' (Thomas Nordmann); (4) The market of photovoltaic will be a European market in the future (Murray Cameron); (5) Development and state of the art of the photovoltaic industry in the Peoples Republic of China (Frank Haugwitz); (6) Silicon for the photovoltaic industry (Karl Hesse); (7) Cell technology: Impulses for a cost effective photovoltaic with valuable silicon (Rolf Brendel); (8) Thin-film solar modules for the photovoltaic - state of the art and industrial perspectives (Michael Powalla); (9) Modules - bottleneck and flood of orders: How to act an installer? (Helmut Godard); (10) Photovoltaic open-field systems - Actual experiences and conflict lines (Ole Langniss); (11) Comparison of actual and future trends of Balance-of-System costs for large scale ground based PV systems with crystalline and thin-film modules (Manfred Baechler); (12) Financing PX projects from a Bank perspective (Joachim Treder); (13) Criteria of quality for solar fonds - Criteria of evaluation for capital investors and self-commitment for emission houses (Ulla Meixner); (14) Analysis of the distribution pathways for photovoltaic plants from the manufacturer to the final customer considering the decreasing demand and increasing prices (Michael Forst); (15) Solar power 2005 - Evaluation of real operational data of 1,000 plants in Germany (Gerd Heilscher); (16) Improvement of PV-inverter efficiency - targets, pathways

  7. Modeling and simulation of photovoltaic solar panel

    International Nuclear Information System (INIS)

    Belarbi, M.; Haddouche, K.; Midoun, A.

    2006-01-01

    In this article, we present a new approach for estimating the model parameters of a photovoltaic solar panel according to the irradiance and temperature. The parameters of the one diode model are given from the knowledge of three operating points: short-circuit, open circuit, and maximum power. In the first step, the adopted approach concerns the resolution of the system of equations constituting the three operating points to write all the model parameters according to series resistance. Secondly, we make an iterative resolution at the optimal operating point by using the Newton-Raphson method to calculate the series resistance value as well as the model parameters. Once the panel model is identified, we consider other equations for taking into account the irradiance and temperature effect. The simulation results show the convergence speed of the model parameters and the possibility of visualizing the electrical behaviour of the panel according to the irradiance and temperature. Let us note that a sensitivity of the algorithm at the optimal operating point was observed owing to the fact that a small variation of the optimal voltage value leads to a very great variation of the identified parameters values. With the identified model, we can develop algorithms of maximum power point tracking, and make simulations of a solar water pumping system.(Author)

  8. APSA - A new generation of photovoltaic solar arrays

    Science.gov (United States)

    Stella, P. M.; Kurland, R. M.

    1989-01-01

    This paper provides details on the Advanced Photovoltaic Solar Array (APSA) wing design, fabrication, and testing. The impact of array size change on performance and mechanical characteristics is discussed. Projections for future performance enhancements that may be expected through the use of advanced solar cells presently under development are examined.

  9. Printing Processes Used to Manufacture Photovoltaic Solar Cells

    Science.gov (United States)

    Rardin, Tina E.; Xu, Renmei

    2011-01-01

    There is a growing need for renewable energy sources, and solar power is a good option in many instances. Photovoltaic solar panels are now being manufactured via various methods, and different printing processes are being incorporated into the manufacturing process. Screen printing has been used most prevalently in the printing process to make…

  10. Exergy analysis of photovoltaic solar collector

    International Nuclear Information System (INIS)

    Sopian, K.; Othman, M.Y.Hj.

    1998-01-01

    The exergy analysis (availability or second law analysis) is applied to the photovoltaic thermal solar collector. Photovoltaic thermal collector is a special type of solar collector where electricity and heat are produced simultaneously. The electricity produced from the photovoltaic thermal collector is all converted into useful work. The available quantity of the heat collected can readily be determined by taking into account both the quantity (heat quantity) and quality ( a function of temperature) of the thermal energy. Therefore, using the concept of exergy allows heat produced from the thermal collector and the electricity generated from the photovoltaic cells to be compared or to be evaluated on the basis of a common measure such as the effectiveness on solar energy collection or the total amount of available energy. In this paper, the effectiveness of solar energy collection is called combined photovoltaic thermal exergy efficiency. An experimental setup of a double pas photovoltaic thermal solar collector has been deigned, fabricated and tested. (author)

  11. Photovoltaic solar energy: which realities for 2020? Summarized synthesis

    International Nuclear Information System (INIS)

    2011-01-01

    This report first describes the situation of the photovoltaic as situated at a crossroad with strong development possibilities for the French photovoltaic sector. It presents the photovoltaic energy as a competitive, regulatory and ecologic one, and therefore inescapable. It outlines stakes and obstacles of the French situation regarding the development of this sector. It highlights the economic and social benefit investing in this sector. Some propositions are stated for the promotion of the photovoltaic solar sector. Challenges are identified

  12. Mechanical and thermal design of hybrid blankets

    International Nuclear Information System (INIS)

    Schultz, K.R.

    1978-01-01

    The thermal and mechanical aspects of hybrid reactor blanket design considerations are discussed. This paper is intended as a companion to that of J. D. Lee of Lawrence Livermore Laboratory on the nuclear aspects of hybrid reactor blanket design. The major design characteristics of hybrid reactor blankets are discussed with emphasis on the areas of difference between hybrid reactors and standard fusion or fission reactors. Specific examples are used to illustrate the design tradeoffs and choices that must be made in hybrid reactor design. These examples are drawn from the work on the Mirror Hybrid Reactor

  13. Constructal Optimization of Top Contact Metallization of a Photovoltaic Solar Cell

    OpenAIRE

    Bhakta, Aditya; Bandyopadhyay, Santanu

    2010-01-01

    A top contact metallization of a photovoltaic solar cell collects the current generated by incident solar radiation. Several power-loss mechanisms are associated with the current flow through the front contact grid. The design of the top metal contact grid is one of the most important areas of efficient photovoltaic solar cell design. In this paper, an approach based on the constructal theory is proposed to design the grid pattern in a photovoltaic solar cell, minimizing total resistive losse...

  14. Energy Efficiency Analysis of Solar Photovoltaic Solar-Thermal Components lntegrating with Double Source Heat Pump System%太阳能光伏光热组件与双源热泵一体化系统节能性分析

    Institute of Scientific and Technical Information of China (English)

    李新锐; 陈剑波; 王成武

    2018-01-01

    The integration of distributed solar photovoltaic solar -thermal components and double source heat pump system is a system combined with a variety of energy - saving technology, so it is necessary to study its energy saving property. Based on the comparison with the solar heat pump and air-source heat pump, through opening the double source mode and separately opening the water source mode,or running air source mode,the water-heating time of heating water tank and the input power of the heat pump are compared,it is concluded that the double heat source heat pump unit has higher energy efficiency than the single air source heat pump and the conventional solar heat pump unit.%考虑到分布式太阳能光伏光热组件与双源热泵一体化系统是一种结合多种节能技术的系统,有必要对其节能性进行研究.在对该系统与常规太阳能热泵、空气源热泵比较的基础上,选取冬天开启双源模式和单独开启水源模式、空气源模式时的3种工况,通过比较供热水箱完成制热水的时间和热泵输入功率,分析得出双热源热泵机组比单一的空气源热泵、常规太阳能热泵机组具有较高的节能性.

  15. Thermal stability of PMMA–clay hybrids

    Indian Academy of Sciences (India)

    Administrator

    Thermal stability of PMMA–clay hybrids. TANUSHREE CHOUDHURY* and NIRENDRA M MISRA. Department of Applied Chemistry, Indian School of Mines University, Dhanbad 826 004, India. MS received 9 December 2008. Abstract. Materials with small particle size are being extensively used in composites and hybrid ...

  16. Automatic data acquisition system for a photovoltaic solar plant

    Energy Technology Data Exchange (ETDEWEB)

    Santos, A.; Barrio, C.L.; Guerra, A.G.

    1986-01-01

    An autonomous monitoring system for photovoltaic solar plants is described. The system is able to collect data about the plant's physical and electrical characteristics and also about the environmental conditions. It may present the results on a display, if requested, but its main function is measuring periodically a set of parameters, including several points in the panel I-V characteristics, in an unattended mode. The data are stored on a magnetic tape for later processing on a computer. The system hardware and software are described, as well as their main functions.

  17. Concrete Embedded Dye-Synthesized Photovoltaic Solar Cell

    OpenAIRE

    Hosseini, T.; Flores-Vivian, I.; Sobolev, K.; Kouklin, N.

    2013-01-01

    This work presents the concept of a monolithic concrete-integrated dye-synthesized photovoltaic solar cell for optical-to-electrical energy conversion and on-site power generation. The transport measurements carried out in the dark revealed the presence of VOC of ~190?mV and ISC of ~9??A, induced by the electrochemical conversion of concrete-supplied ionic impurities at the electrodes. The current-voltage measurements performed under illumination at incident optical powers of ~46?mW confirmed...

  18. Comparative Study of Two New Configurations of Solar Photovoltaic Thermal Collectors

    OpenAIRE

    K. Touafek; A. Khelifa; E. H. Khettaf; A. Embarek

    2013-01-01

    Hybrid photovoltaic thermal (PV/T) solar system comprises a solar collector which is disposed on photovoltaic solar cells. The disadvantage of a conventional photovoltaic cell is that its performance decreases as the temperature increases. Indeed, part of the solar radiation is converted into electricity and is dissipated as heat, increasing the temperature of the photovoltaic cell with respect to the ambient temperature. The objective of this work is to study experimentally and implement a h...

  19. Integration of photovoltaic and concentrated solar thermal technologies for H2 production by the hybrid sulfur cycle

    Science.gov (United States)

    Liberatore, Raffaele; Ferrara, Mariarosaria; Lanchi, Michela; Turchetti, Luca

    2017-06-01

    It is widely agreed that hydrogen used as energy carrier and/or storage media may significantly contribute in the reduction of emissions, especially if produced by renewable energy sources. The Hybrid Sulfur (HyS) cycle is considered as one of the most promising processes to produce hydrogen through the water-splitting process. The FP7 project SOL2HY2 (Solar to Hydrogen Hybrid Cycles) investigates innovative material and process solutions for the use of solar heat and power in the HyS process. A significant part of the SOL2HY2 project is devoted to the analysis and optimization of the integration of the solar and chemical (hydrogen production) plants. In this context, this work investigates the possibility to integrate different solar technologies, namely photovoltaic, solar central receiver and solar troughs, to optimize their use in the HyS cycle for a green hydrogen production, both in the open and closed process configurations. The analysis carried out accounts for different combinations of geographical location and plant sizing criteria. The use of a sulfur burner, which can serve both as thermal backup and SO2 source for the open cycle, is also considered.

  20. New Prototype of Photovoltaic Solar Tracker Based on Arduino

    Directory of Open Access Journals (Sweden)

    Carlos Morón

    2017-08-01

    Full Text Available The global increase in energy demand and exponential exhaustion of fossil recourses has favored the development of new systems of electricity production. Photovoltaic solar energy is undoubtedly one that has the highest application in housings, due to its simplicity and easy implementation. In this work, a new prototype of photovoltaic solar tracker with Arduino platform was developed. Feedback control system that allows carrying out solar tracking with two axes using a stepper motor and linear actuator was established through an electronic circuit based on photodiodes. Moreover, real construction of the prototype was carried out, where the effectiveness of the design and its capacity to draw a maximum benefit of an incident radiation can be observed, placing the panel perpendicularly to the received energy and improving its performance for its application in future installations in housings. Results obtained from the comparison between the developed prototype and a static panel oriented according to the latitude of the area, show about 18% energy gain.

  1. 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.

  2. Simulated hail impact testing of photovoltaic solar panels

    Science.gov (United States)

    Moore, D.; Wilson, A.; Ross, R.

    1978-01-01

    Techniques used to simulate and study the effect of hail on photovoltaic solar panels are described. Simulated hail stones (frozen ice spheres projected at terminal velocity) or steel balls were applied by air guns, gravity drop, or static loading. Tests with simulated hail and steel balls yielded different results. The impact strength of 10 commercially available flat-plate photovoltaic modules was tested. It was found that none of the six panel designs incorporating clear potting silicone material as the outermost layer remained undamaged by 1-in. simulated hailstones, while a photovoltaic module equipped with a 0.188-in.-thick acrylic cover sheet would be able to withstand the impact of a 2-in.-diameter hailstone.

  3. Concrete embedded dye-synthesized photovoltaic solar cell.

    Science.gov (United States)

    Hosseini, T; Flores-Vivian, I; Sobolev, K; Kouklin, N

    2013-09-25

    This work presents the concept of a monolithic concrete-integrated dye-synthesized photovoltaic solar cell for optical-to-electrical energy conversion and on-site power generation. The transport measurements carried out in the dark revealed the presence of VOC of ~190 mV and ISC of ~9 μA, induced by the electrochemical conversion of concrete-supplied ionic impurities at the electrodes. The current-voltage measurements performed under illumination at incident optical powers of ~46 mW confirmed the generation of electrical power of ~0.64 μW with almost half generated via battery effect. This work presents a first step towards realizing the additional pathways to low-cost electrical power production in urban environments based on a combined use of organic dyes, nanotitania and concrete technology.

  4. Observatory of photovoltaic solar energy in France - 20. edition

    International Nuclear Information System (INIS)

    2016-12-01

    After an overview of important events in the World regarding the development of photovoltaic solar energy in 2016, and predictions regarding new connected installations in 2016, this document present graphs and figures which illustrate the evolution of the photovoltaic fleet in the World, the comparison of production costs of new electric power generation capacities, the evolution of the French photovoltaic power production since 2009, the evolution of the distribution of the French fleet in terms of installation power (from large projects to residential), of connections to the grid, of number of connections and purchase tariffs for the different types of installations (residential, medium roofs, large roofs, very large roofs, very large ground-based or roof-based projects) and for queuing projects, in terms of evolution of purchase tariffs since 2011, and of evolution of impact on the CSPE financing system

  5. Key technical and non-technical challenges for mass deployment of photovoltaic solar energy (PV)

    International Nuclear Information System (INIS)

    Sinke, W.C.

    2001-12-01

    Photovoltaic solar energy (PV) is used for direct conversion of sunlight into electricity. It is not to be confused with low-temperature thermal solar energy (e.g. solar domestic hot water systems) and with solar electricity production using a conventional high-temperature steam cycle (using parabolic troughs or 'power towers'). Important features of PV are: inherently renewable; sustainable if well designed, manufactured, used, and disposed; no moving parts, quiet; reliable if well designed and engineered; modular (from milliwatts to multi-megawatts); suitable for a wide variety of applications (stand-alone and grid-connected); large potential (regionally and globally); intermittent; capacity factor (ratio of average system power to installed (=peak) power) =0.08-0.24. PV is among the major renewable energy technologies in all well known energy scenarios, although a substantial role in % of the total energy production can only be achieved on the long term (typically 40-60 years years). Fortunately, long before that the PV market may be a rapidly growing, multi-billion euro business, providing enormous economic opportunities and many jobs

  6. EH AND S ANALYSIS OF DYE-SENSITIZED PHOTOVOLTAIC SOLAR CELL PRODUCTION

    International Nuclear Information System (INIS)

    BOWERMAN, B.; FTHENAKIS, V.

    2001-01-01

    Photovoltaic solar cells based on a dye-sensitized nanocrystalline titanium dioxide photoelectrode have been researched and reported since the early 1990's. Commercial production of dye-sensitized photovoltaic solar cells has recently been reported in Australia. In this report, current manufacturing methods are described, and estimates are made of annual chemical use and emissions during production. Environmental, health and safety considerations for handling these materials are discussed. This preliminary EH and S evaluation of dye-sensitized titanium dioxide solar cells indicates that some precautions will be necessary to mitigate hazards that could result in worker exposure. Additional information required for a more complete assessment is identified

  7. Assessment of low-cost manufacturing process sequences. [photovoltaic solar arrays

    Science.gov (United States)

    Chamberlain, R. G.

    1979-01-01

    An extensive research and development activity to reduce the cost of manufacturing photovoltaic solar arrays by a factor of approximately one hundred is discussed. Proposed and actual manufacturing process descriptions were compared to manufacturing costs. An overview of this methodology is presented.

  8. A strategic research agenda for photovoltaic solar energy technology : report of the EU PV technology platform

    NARCIS (Netherlands)

    Sinke, W.C.; Zolingen, van R.J.C.; Ballif, C.; Bett, A.; Dimmler, B.; Dimova-Malinovska, D.; Fath, P.; Ferrazza, F.; Gabler, H.-J.; Hall, M.; Marti, A.; Mason, N.; Mellikov, E.; Milner, A.; Mogensen, P.; Panhuber, C.; Pearsall, N.; Poortmans, J.; Protogeropoulos, C.; Sarre, G.; Sarti, D.; Strauss, P.; Topic, M.; Zdanowicz, T.

    2007-01-01

    The EU PV Technology Platform [1] aims at joining forces on a European level to contribute to the further development of photovoltaic solar energy into a competitive technology that can be applied on a large scale and to the strengthening of the position of the European PV industry on the global

  9. On the Effectiveness of Feed-in Tariffs in the Development of Photovoltaic Solar

    NARCIS (Netherlands)

    E. Dijkgraaf (Elbert); T. van Dorp (Tom); E. Maasland (Emiel)

    2014-01-01

    markdownabstract__Abstract__ Growing concern for climate change and rising scarcity of fossil fuels prompted governments to stimulate the development of renewables. This paper empirically tests whether feed-in tariff (FIT) policies have been effective in the development of photovoltaic solar

  10. Chip Integrated, Hybrid EHD/Capillary Driven Thermal Management System

    Data.gov (United States)

    National Aeronautics and Space Administration — Chip-Integrated, Hybrid EHD/Capillary-Driven Thermal Management System is a two year that will leverage independently attained yet related prototype hardware...

  11. Intelligent system for a remote diagnosis of a photovoltaic solar power plant

    International Nuclear Information System (INIS)

    Sanz-Bobi, M A; San Roque, A Muñoz; Marcos, A de; Bada, M

    2012-01-01

    Usually small and mid-sized photovoltaic solar power plants are located in rural areas and typically they operate unattended. Some technicians are in charge of the supervision of these plants and, if an alarm is automatically issued, they try to investigate the problem and correct it. Sometimes these anomalies are detected some hours or days after they begin. Also the analysis of the causes once the anomaly is detected can take some additional time. All these factors motivated the development of a methodology able to perform continuous and automatic monitoring of the basic parameters of a photovoltaic solar power plant in order to detect anomalies as soon as possible, to diagnose their causes, and to immediately inform the personnel in charge of the plant. The methodology proposed starts from the study of the most significant failure modes of a photovoltaic plant through a FMEA and using this information, its typical performance is characterized by the creation of its normal behaviour models. They are used to detect the presence of a failure in an incipient or current form. Once an anomaly is detected, an automatic and intelligent diagnosis process is started in order to investigate the possible causes. The paper will describe the main features of a software tool able to detect anomalies and to diagnose them in a photovoltaic solar power plant.

  12. Low cost silicon-on-ceramic photovoltaic solar cells

    Science.gov (United States)

    Koepke, B. G.; Heaps, J. D.; Grung, B. L.; Zook, J. D.; Sibold, J. D.; Leipold, M. H.

    1980-01-01

    A technique has been developed for coating low-cost mullite-based refractory substrates with thin layers of solar cell quality silicon. The technique involves first carbonizing one surface of the ceramic and then contacting it with molten silicon. The silicon wets the carbonized surface and, under the proper thermal conditions, solidifies as a large-grained sheet. Solar cells produced from this composite silicon-on-ceramic material have exhibited total area conversion efficiencies of ten percent.

  13. Photovoltaic solar panels of crystalline silicon: characterization and separation

    International Nuclear Information System (INIS)

    Diasa, P.R.; Benevita, M.G.; Veita, H.M.

    2014-01-01

    The search for alternative power generation sources has been intensified in recent years. One of these alternatives is solar energy, since it is a virtually inexhaustible source and generates relatively small environmental impact compared to other traditional generation sources. The collection of solar energy and its conversion into thermal or electrical energy is only possible through the use of photovoltaic panels. These panels have a limited lifespan and will eventually be replaced by new ones. Thus, in the near future, large amounts of solar modules can be discarded as waste electronics. In order to retrieve important raw materials, reducing production costs and environmental impacts, recycling such materials is important. In this paper, photovoltaic module components were characterized through visual inspection, FRX, EDS and AAS. The glass was identified as ordinary glass (soda-lime glass), which allows reuse without any previous treatment and the metallic filaments were identified as tin- lead coated copper. (author)

  14. Space satellite power system. [conversion of solar energy by photovoltaic solar cell arrays

    Science.gov (United States)

    Glaser, P. E.

    1974-01-01

    The concept of a satellite solar power station was studied. It is shown that it offers the potential to meet a significant portion of future energy needs, is pollution free, and is sparing of irreplaceable earth resources. Solar energy is converted by photovoltaic solar cell arrays to dc energy which in turn is converted into microwave energy in a large active phased array. The microwave energy is beamed to earth with little attenuation and is converted back to dc energy on the earth. Economic factors are considered.

  15. Thermal simulation of a cooling system of hybrid commercial vehicles; Thermalsimulation eine Hybrid-LKW-Kuehlsystems

    Energy Technology Data Exchange (ETDEWEB)

    Stroh, Christoph; Schnoerch, Stefan; Rathberger, Christian [Magna Powertrain Engineering Center Steyr GmbH und Co. KG, St. Valentin (Austria)

    2012-11-01

    In the past few years hybrid vehicles have been in the center of automotive engineering efforts, in particular in the field of passenger cars. But hybrid powertrains will also be important for commercial trucks. This focus on hybrid vehicles leads to high demands on thermal management since the additional components in a hybrid vehicle need appropriate cooling or even heating. In the given paper the simulation of a complete cooling system of a hybrid commercial vehicle will be explained. For this virtual examination the commercial 1D thermal management software KULI will be used, a co-simulation with several programs will not be done deliberately. Yet all aspects which are relevant for a global assessment of the thermal management are considered. The main focus is put on the investigation of appropriate concepts for the fluid circuits, including low and high temperature circuits, electric water pumps, etc. Moreover, also a refrigerant circuit with a chiller for active battery cooling will be used, the appropriate control strategy is implemented as well. For simulating transient profiles a simple driving simulation model is included, using road profile, ambient conditions, and various vehicle parameters as input. In addition an engine model is included which enables the investigation of fuel consumption potentials. This simulation model shows how the thermal management of a hybrid vehicle can be investigated with a single program and with reasonable effort. (orig.)

  16. Optimization of concentrator photovoltaic solar cell performance through photonic engineering

    Energy Technology Data Exchange (ETDEWEB)

    Harris, James [Stanford Univ., CA (United States)

    2018-04-04

    The goal of this program was to incorporate two new and innovative design concepts into the design and production of CPV cells that have near zero added cost, yet significantly increase the operational efficiency of CPV modules. The program focused developing luminescent coupling effects and radiative cooling layers to increase efficiency and suppress CPV module power losses due to spectral variations and heating. The major results of the program were: 1) The optics of three commercial refractive (Fresnel) concentrators were characterized and prevent application of radiative cooling concepts due to strong mid-IR absorption (4-12µm) required to effectively radiate blackbody radiation from the cells and provide cooling. Investigation of alternative materials for the concentrator lenses produced only undesirable options—materials with reasonable mid-IR transmission for cooling only had about 30-40 visible transmission, thus reducing incident sunlight by >50%. While our investigation was somewhat limited, our work suggests that the only viable concentrator system that can incorporate radiative cooling utilizes reflective optics. 2) With limited ability to test high concentration CPV cells (requires outdoor testing), we acquired both semi-crystalline and crystalline Si cells and tested them in our outdoor facility and demonstrated 4°C cooling using a simple silica layer coating on the cells. 3) Characterizing Si cells in the IR associated with radiative cooling, we observed very significant near-IR absorption that increases the cell operating temperature by a similar amount, 4-5°C. By appropriate surface layer design, one can produce a layer that is highly reflective in the near-IR (1.5-4µm) and highly emissive in the mid-IR (5-15µm), thus reducing cell operational temperature by 10°C and increasing efficiency by ~1% absolute. The radiative cooling effect in c-Si solar cells might be further improved by providing a higher thermal conductive elastomer for

  17. Hybrid photovoltaic–thermal solar collectors dynamic modeling

    International Nuclear Information System (INIS)

    Amrizal, N.; Chemisana, D.; Rosell, J.I.

    2013-01-01

    Highlights: ► A hybrid photovoltaic/thermal dynamic model is presented. ► The model, once calibrated, can predict the power output for any set of climate data. ► The physical electrical model includes explicitly thermal and irradiance dependences. ► The results agree with those obtained through steady-state characterization. ► The model approaches the junction cell temperature through the system energy balance. -- Abstract: A hybrid photovoltaic/thermal transient model has been developed and validated experimentally. The methodology extends the quasi-dynamic thermal model stated in the EN 12975 in order to involve the electrical performance and consider the dynamic behavior minimizing constraints when characterizing the collector. A backward moving average filtering procedure has been applied to improve the model response for variable working conditions. Concerning the electrical part, the model includes the thermal and radiation dependences in its variables. The results revealed that the characteristic parameters included in the model agree reasonably well with the experimental values obtained from the standard steady-state and IV characteristic curve measurements. After a calibration process, the model is a suitable tool to predict the thermal and electrical performance of a hybrid solar collector, for a specific weather data set.

  18. Thermal Properties of Hybrid Carbon Nanotube/Carbon Fiber Polymer

    Science.gov (United States)

    Kang, Jin Ho; Cano, Roberto J.; Luong, Hoa; Ratcliffe, James G.; Grimsley, Brian W.; Siochi, Emilie J.

    2016-01-01

    Carbon fiber reinforced polymer (CFRP) composites possess many advantages for aircraft structures over conventional aluminum alloys: light weight, higher strength- and stiffness-to-weight ratio, and low life-cycle maintenance costs. However, the relatively low thermal and electrical conductivities of CFRP composites are deficient in providing structural safety under certain operational conditions such as lightning strikes. One possible solution to these issues is to interleave carbon nanotube (CNT) sheets between conventional carbon fiber (CF) composite layers. However, the thermal and electrical properties of the orthotropic hybrid CNT/CF composites have not been fully understood. In this study, hybrid CNT/CF polymer composites were fabricated by interleaving layers of CNT sheets with Hexcel (Registered Trademark) IM7/8852 prepreg. The CNT sheets were infused with a 5% solution of a compatible epoxy resin prior to composite fabrication. Orthotropic thermal and electrical conductivities of the hybrid polymer composites were evaluated. The interleaved CNT sheets improved the in-plane thermal conductivity of the hybrid composite laminates by about 400% and the electrical conductivity by about 3 orders of magnitude.

  19. Performance analysis of a hybrid photovoltaic thermal solar air heater

    International Nuclear Information System (INIS)

    Othman, Mohd Yusof; Yatim, Baharudin; Abu Bakar, Mohd Nazari; Sopian, Kamaruzzaman

    2006-01-01

    A photovoltaic (PV/T) air heater is a collector that combines thermal and photovoltaic systems in one single hybrid generating unit. It generators both thermal and electrical energies simultaneously. A new design of a double-pass photovoltaic-thermal solar air collector with CPC and fins was successfully developed and fabricated at Universiti Kebangsaam Malaysia. This collector tested under actual environmental conditions to study its performance over a range of operating conditions. The test set-up, instrumentation and measurement are described further. It was found that the performance of the collector was in agreement with the theoretical prediction. Results of the outdoors test are presented and discussed(Author)

  20. The electrodeposition of multilayers on a polymeric substrate in flexible organic photovoltaic solar cells

    Science.gov (United States)

    Guedes, Andre F. S.; Guedes, Vilmar P.; Souza, Monica L.; Tartari, Simone; Cunha, Idaulo J.

    2015-09-01

    Flexible organic photovoltaic solar cells have drawn intense attention due to their advantages over competing solar cell technologies. The method utilized to deposit as well as to integrate solutions and processed materials, manufacturing organic solar cells by the Electrodeposition System, has been presented in this research. In addition, we have demonstrated a successful integration of a process for manufacturing the flexible organic solar cell prototype and we have discussed on the factors that make this process possible. The maximum process temperature was 120°C, which corresponds to the baking of the active polymeric layer. Moreover, the new process of the Electrodeposition of complementary active layer is based on the application of voltage versus time in order to obtain a homogeneous layer with thin film. This thin film was not only obtained by the electrodeposition of PANI-X1 on P3HT/PCBM Blend, but also prepared in perchloric acid solution. Furthermore, these flexible organic photovoltaic solar cells presented power conversion efficiency of 12% and the inclusion of the PANI-X1 layer reduced the effects of degradation on these organic photovoltaic panels induced by solar irradiation. Thus, in the Scanning Electron Microscopy (SEM), these studies have revealed that the surface of PANI-X1 layers is strongly conditioned by the dielectric surface morphology.

  1. Proceedings of the international photovoltaic solar energy conference held in Glasgow 1-5 May 2000

    International Nuclear Information System (INIS)

    Anon.

    2001-02-01

    The European Photovoltaic Solar Energy Conferences are dedicated to accelerating the impetus towards sustainable development of global PV markets. The 16th in the series, held in Glasgow UK, brought together more than 1500 delegates from 72 countries, and provided an important and vital forum for information exchange in the field. The Conference Proceedings place on record a new phase of market development and scientific endeavour in the PV industry, representing current and innovative thinking in all aspects of the science, technology, markets and business of photovoltaics. In three volumes, the Proceedings present some 790 papers selected for presentation by the scientific review committee of the 16th European Photovoltaic Solar Energy Conference. The Comprehensive range of topics covered comprises: Fundamentals, Novel Devices and New Materials. Thin Film Cells and Technologies. Space Cells and Systems. Crystalline Silicon Solar Cells and Technologies. PV Integration in Buildings. PV Modules and Components of PV Systems. Implementation, Strategies, National Programs and Financing Schemes. Market Deployment in Developing Countries. (author)

  2. Detecting photovoltaic solar panels using hyperspectral imagery and estimating solar power production

    Science.gov (United States)

    Czirjak, Daniel

    2017-04-01

    Remote sensing platforms have consistently demonstrated the ability to detect, and in some cases identify, specific targets of interest, and photovoltaic solar panels are shown to have a unique spectral signature that is consistent across multiple manufacturers and construction methods. Solar panels are proven to be detectable in hyperspectral imagery using common statistical target detection methods such as the adaptive cosine estimator, and false alarms can be mitigated through the use of a spectral verification process that eliminates pixels that do not have the key spectral features of photovoltaic solar panel reflectance spectrum. The normalized solar panel index is described and is a key component in the false-alarm mitigation process. After spectral verification, these solar panel arrays are confirmed on openly available literal imagery and can be measured using numerous open-source algorithms and tools. The measurements allow for the assessment of overall solar power generation capacity using an equation that accounts for solar insolation, the area of solar panels, and the efficiency of the solar panels conversion of solar energy to power. Using a known location with readily available information, the methods outlined in this paper estimate the power generation capabilities within 6% of the rated power.

  3. Optimization and modeling of a photovoltaic solar integrated system by neural networks

    International Nuclear Information System (INIS)

    Ashhab, Moh'd Sami S.

    2008-01-01

    A photovoltaic solar integrated system is modeled with artificial neural networks (ANN's). Data relevant to the system performance was collected on April, 4th 1993 and every 15 min during the day. This input-output data is used to train the ANN. The ANN approximates the data well and therefore can be relied on in predicting the system performance, namely, system efficiencies. The solar system consists of a solar trainer which contains a photovoltaic panel, a DC centrifugal pump, flat plate collectors, storage tank, a flowmeter for measuring the water mass flow rate, pipes, pyranometer for measuring the solar intensity, thermocouples for measuring various system temperatures and wind speed meter. The complex method constrained optimization is applied to the solar system ANN model to find the operating conditions of the system that will produce the maximum system efficiencies. This information will be very hard to obtain by just looking at the available historical input-output data

  4. Optimization and modeling of a photovoltaic solar integrated system by neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Ashhab, Moh' d Sami S. [Department of Mechanical Engineering, The Hashemite University, Zarqa 13115 (Jordan)

    2008-11-15

    A photovoltaic solar integrated system is modeled with artificial neural networks (ANN's). Data relevant to the system performance was collected on April, 4th 1993 and every 15 min during the day. This input-output data is used to train the ANN. The ANN approximates the data well and therefore can be relied on in predicting the system performance, namely, system efficiencies. The solar system consists of a solar trainer which contains a photovoltaic panel, a DC centrifugal pump, flat plate collectors, storage tank, a flowmeter for measuring the water mass flow rate, pipes, pyranometer for measuring the solar intensity, thermocouples for measuring various system temperatures and wind speed meter. The complex method constrained optimization is applied to the solar system ANN model to find the operating conditions of the system that will produce the maximum system efficiencies. This information will be very hard to obtain by just looking at the available historical input-output data. (author)

  5. Development of low-cost silicon crystal growth techniques for terrestrial photovoltaic solar energy conversion

    Science.gov (United States)

    Zoutendyk, J. A.

    1976-01-01

    Because of the growing need for new sources of electrical energy, photovoltaic solar energy conversion is being developed. Photovoltaic devices are now being produced mainly from silicon wafers obtained from the slicing and polishing of cylindrically shaped single crystal ingots. Inherently high-cost processes now being used must either be eliminated or modified to provide low-cost crystalline silicon. Basic to this pursuit is the development of new or modified methods of crystal growth and, if necessary, crystal cutting. If silicon could be grown in a form requiring no cutting, a significant cost saving would potentially be realized. Therefore, several techniques for growth in the form of ribbons or sheets are being explored. In addition, novel techniques for low-cost ingot growth and cutting are under investigation.

  6. A new and inexpensive temperature-measuring system. Application to photovoltaic solar facilities

    Energy Technology Data Exchange (ETDEWEB)

    Bohorquez, Miguel Angel Martinez; Enrique Gomez, Juan Manuel; Andujar Marquez, Jose Manuel [Departamento de Ingenieria Electronica, de Sistemas Informaticos y Automatica, Universidad de Huelva, Carretera Huelva - Palos de la, Frontera S/N, 21819 Huelva (Spain)

    2009-06-15

    This article presents the design, construction and testing of a new and inexpensive digital sensor-based temperature-measuring system, whose principal characteristics are: precision, ease of connection, immunity to noise, remote operation and easy scaling, and all this at a very low cost. This new digital sensor-based measuring system overcomes the traditional problems of digital measuring sensors, offering characteristics similar to Pt100-based measuring systems, and therefore can be used in any installation where reliable temperature measurement is necessary. It is especially suitable for installations where cost is a deciding factor in the choice of measuring system. It presents a practical application of the developed instrumentation system for use in photovoltaic solar facilities. This new temperature-measuring system has been registered in the Spanish Patent and Trademark Office with the number P200803364. (author)

  7. Chapter 1: Reliably Measuring the Performance of Emerging Photovoltaic Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Rumbles, Garry [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Reese, Matthew O [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Marshall, Ashley [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-11-08

    Determining the power conversion efficiency of photovoltaic solar cells, especially those from new, emerging areas of technology, is important if advances in performance are to be made. However, although precise measurements are important, it is the accuracy of these types of measurements that can cause issues. Accurate measurements not only promote the development of new technology platforms, but they also enable comparisons with established technologies and allow assessments of advancements within the same field. This chapter provides insights into how measurements can be made with reasonable accuracy using both the components of the measuring system and a good protocol to acquire good data. The chapter discusses how to measure a calibrated lamp spectrum, determine a spectral mismatch factor, identify the correct reference cell and filter, define the illuminated active area, measure J-V curves to avoid any hysteresis effects, take note of sample degradation issues and avoid the temptation to artificially enhance efficiency data.

  8. Rectification of electronic heat current by a hybrid thermal diode.

    Science.gov (United States)

    Martínez-Pérez, Maria José; Fornieri, Antonio; Giazotto, Francesco

    2015-04-01

    Thermal diodes--devices that allow heat to flow preferentially in one direction--are one of the key tools for the implementation of solid-state thermal circuits. These would find application in many fields of nanoscience, including cooling, energy harvesting, thermal isolation, radiation detection and quantum information, or in emerging fields such as phononics and coherent caloritronics. However, both in terms of phononic and electronic heat conduction (the latter being the focus of this work), their experimental realization remains very challenging. A highly efficient thermal diode should provide a difference of at least one order of magnitude between the heat current transmitted in the forward temperature (T) bias configuration (Jfw) and that generated with T-bias reversal (Jrev), leading to ℛ = Jfw/Jrev ≫ 1 or ≪ 1. So far, ℛ ≈ 1.07-1.4 has been reported in phononic devices, and ℛ ≈ 1.1 has been obtained with a quantum-dot electronic thermal rectifier at cryogenic temperatures. Here, we show that unprecedentedly high ratios of ℛ ≈ 140 can be achieved in a hybrid device combining normal metals tunnel-coupled to superconductors. Our approach provides a high-performance realization of a thermal diode for electronic heat current that could be successfully implemented in true low-temperature solid-state thermal circuits.

  9. Hybrid Solar: A Review on Photovoltaic and Thermal Power Integration

    Directory of Open Access Journals (Sweden)

    T. T. Chow

    2012-01-01

    Full Text Available The market of solar thermal and photovoltaic electricity generation is growing rapidly. New ideas on hybrid solar technology evolve for a wide range of applications, such as in buildings, processing plants, and agriculture. In the building sector in particular, the limited building space for the accommodation of solar devices has driven a demand on the use of hybrid solar technology for the multigeneration of active power and/or passive solar devices. The importance is escalating with the worldwide trend on the development of low-carbon/zero-energy buildings. Hybrid photovoltaic/thermal (PVT collector systems had been studied theoretically, numerically, and experimentally in depth in the past decades. Together with alternative means, a range of innovative products and systems has been put forward. The final success of the integrative technologies relies on the coexistence of robust product design/construction and reliable system operation/maintenance in the long run to satisfy the user needs. This paper gives a broad review on the published academic works, with an emphasis placed on the research and development activities in the last decade.

  10. Smooth hybrid inflation and non-thermal Type II leptogenesis

    International Nuclear Information System (INIS)

    Sil, Arunansu

    2013-01-01

    We consider a smooth hybrid inflation scenario based on a supersymmetricSU(2) L ⊗ SU(2) R ⊗ U(1) B-L model. The Higgs triplets involved in the model play a key role in inflation as well as in explaining the observed baryon asymmetry of the universe. We show that the baryon asymmetry can originate via non-thermal triplet leptogenesis from the decay of SU(2) B-L triplets, whose tiny vacuum expectation values also provide masses for the light neutrinos. (author)

  11. Photovoltaic solar energy: which realities for 2020? Summarized synthesis; Solaire photovoltaique: quelles realites pour 2020?. Synthese resumee

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    This report first describes the situation of the photovoltaic as situated at a crossroad with strong development possibilities for the French photovoltaic sector. It presents the photovoltaic energy as a competitive, regulatory and ecologic one, and therefore inescapable. It outlines stakes and obstacles of the French situation regarding the development of this sector. It highlights the economic and social benefit investing in this sector. Some propositions are stated for the promotion of the photovoltaic solar sector. Challenges are identified

  12. Hybrid intelligent monironing systems for thermal power plant trips

    Science.gov (United States)

    Barsoum, Nader; Ismail, Firas Basim

    2012-11-01

    Steam boiler is one of the main equipment in thermal power plants. If the steam boiler trips it may lead to entire shutdown of the plant, which is economically burdensome. Early boiler trips monitoring is crucial to maintain normal and safe operational conditions. In the present work two artificial intelligent monitoring systems specialized in boiler trips have been proposed and coded within the MATLAB environment. The training and validation of the two systems has been performed using real operational data captured from the plant control system of selected power plant. An integrated plant data preparation framework for seven boiler trips with related operational variables has been proposed for IMSs data analysis. The first IMS represents the use of pure Artificial Neural Network system for boiler trip detection. All seven boiler trips under consideration have been detected by IMSs before or at the same time of the plant control system. The second IMS represents the use of Genetic Algorithms and Artificial Neural Networks as a hybrid intelligent system. A slightly lower root mean square error was observed in the second system which reveals that the hybrid intelligent system performed better than the pure neural network system. Also, the optimal selection of the most influencing variables performed successfully by the hybrid intelligent system.

  13. Thermal stability of DNA quadruplex-duplex hybrids.

    Science.gov (United States)

    Lim, Kah Wai; Khong, Zi Jian; Phan, Anh Tuân

    2014-01-14

    DNA has the capacity to adopt several distinct structural forms, such as duplex and quadruplex helices, which have been implicated in cellular processes and shown to exhibit important functional properties. Quadruplex-duplex hybrids, generated from the juxtaposition of these two structural elements, could find applications in therapeutics and nanotechnology. Here we used NMR and CD spectroscopy to investigate the thermal stability of two classes of quadruplex-duplex hybrids comprising fundamentally distinct modes of duplex and quadruplex connectivity: Construct I involves the coaxial orientation of the duplex and quadruplex helices with continual base stacking across the two components; Construct II involves the orthogonal orientation of the duplex and quadruplex helices with no base stacking between the two components. We have found that for both constructs, the stability of the quadruplex generally increases with the length of the stem-loop incorporated, with respect to quadruplexes comprising nonstructured loops of the same length, which showed a continuous drop in stability with increasing loop length. The stability of these complexes, particularly Construct I, can be substantially influenced by the base-pair steps proximal to the quadruplex-duplex junction. Bulges at the junction are largely detrimental to the adoption of the desired G-quadruplex topology for Construct I but not for Construct II. These findings should facilitate future design and prediction of quadruplex-duplex hybrids.

  14. Experimental Comparison of Two Configurations of Hybrid Photovoltaic Thermal Collectors

    International Nuclear Information System (INIS)

    Khaled Toufeka; Mourad Haddadib; Ali Mkc

    2011-01-01

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

  15. Subcell Debye behavior analysis of order–disorder effects in triple-junction InGaP-based photovoltaic solar cells

    International Nuclear Information System (INIS)

    Hsiao, Jui-Ju; Chen, Hung-Ing; Huang, Yi-Jen; Wang, Jen-Cheng; Lu, Bing-Yuh; Wu, Ya-Fen; Nee, Tzer-En

    2015-01-01

    Analysis was made of the Subcell Debye behavior of the order–disorder effects in triple-junction InGaP-based photovoltaic solar cells fabricated by a metal organic vapor phase epitaxy (MOVPE) system with careful adjustment of the growth conditions. The order–disorder configurations of the InGaP subcells were investigated after post-annealing treatment at various temperatures in a nitrogen atmosphere. Temperature-dependent photoluminescence (PL) measurements over a broad temperature range provided insight into the roles of the thermophysical phenomena connected with the ordering and disordering in the InGaP alloys. The thermally-related spectroscopic observations associated with the ordering effects on the photon–phonon interactions were confirmed by the McCumber–Sturge theory. The variations of both the full width at half-maximum (FWHM) and shift in the peak of PL with temperature were analyzed. According to the width-related PL observations the effective photon–phonon coupling coefficient and the Debye temperature were 0.53 meV and 424 K, respectively; according to shift-related PL observations of the as-grown sample they were 0.3247 eV and 430 K, respectively, for the width-related PL observation they were 0.29 meV and 421 K; and from the shift-related PL observations for the as-grown ordered samples they were 0.3142 eV and 425 K, respectively, implying that the spontaneously disordered InGaP heterostructures met the demand for improvement of photovoltaic devices. Both the effective photon–phonon coupling coefficient and the Debye temperatures were characterized as functions of the annealing temperature. The Debye temperatures obtained for the disordered and ordered top subcells were consistent with the universal Gruneisen–Bloch relation. - Highlights: • Analysis was made of the Subcell Debye behavior in photovoltaic solar cells. • The order–disorder configurations of the InGaP subcells were investigated. • The Debye temperatures were

  16. Subcell Debye behavior analysis of order–disorder effects in triple-junction InGaP-based photovoltaic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Hsiao, Jui-Ju; Chen, Hung-Ing; Huang, Yi-Jen; Wang, Jen-Cheng [Graduate Institute of Electro-Optical Engineering and Department of Electronic Engineering, Chang Gung University, 259 Wen-Hwa 1st Road, Kwei-Shan, Tao-Yuan, Taiwan ROC (China); Lu, Bing-Yuh [Department of Electronic Engineering, Tungnan University, No.152, Sec. 3, Beishen Road, Shenkeng District, New Taipei City, Taiwan ROC (China); Wu, Ya-Fen [Department of Electronic Engineering, Ming Chi University of Technology, 84 Gungjuan Road, Taishan District, New Taipei City, Taiwan ROC (China); Nee, Tzer-En, E-mail: neete@mail.cgu.edu.tw [Graduate Institute of Electro-Optical Engineering and Department of Electronic Engineering, Chang Gung University, 259 Wen-Hwa 1st Road, Kwei-Shan, Tao-Yuan, Taiwan ROC (China)

    2015-12-15

    Analysis was made of the Subcell Debye behavior of the order–disorder effects in triple-junction InGaP-based photovoltaic solar cells fabricated by a metal organic vapor phase epitaxy (MOVPE) system with careful adjustment of the growth conditions. The order–disorder configurations of the InGaP subcells were investigated after post-annealing treatment at various temperatures in a nitrogen atmosphere. Temperature-dependent photoluminescence (PL) measurements over a broad temperature range provided insight into the roles of the thermophysical phenomena connected with the ordering and disordering in the InGaP alloys. The thermally-related spectroscopic observations associated with the ordering effects on the photon–phonon interactions were confirmed by the McCumber–Sturge theory. The variations of both the full width at half-maximum (FWHM) and shift in the peak of PL with temperature were analyzed. According to the width-related PL observations the effective photon–phonon coupling coefficient and the Debye temperature were 0.53 meV and 424 K, respectively; according to shift-related PL observations of the as-grown sample they were 0.3247 eV and 430 K, respectively, for the width-related PL observation they were 0.29 meV and 421 K; and from the shift-related PL observations for the as-grown ordered samples they were 0.3142 eV and 425 K, respectively, implying that the spontaneously disordered InGaP heterostructures met the demand for improvement of photovoltaic devices. Both the effective photon–phonon coupling coefficient and the Debye temperatures were characterized as functions of the annealing temperature. The Debye temperatures obtained for the disordered and ordered top subcells were consistent with the universal Gruneisen–Bloch relation. - Highlights: • Analysis was made of the Subcell Debye behavior in photovoltaic solar cells. • The order–disorder configurations of the InGaP subcells were investigated. • The Debye temperatures were

  17. Implementation of a submicrometer patterning technique in azopolymer films towards optimization of photovoltaic solar cells efficiency

    International Nuclear Information System (INIS)

    Cocoyer, C.; Rocha, L.; Fiorini-Debuisschert, C.; Sicot, L.; Vaufrey, D.; Sentein, C.; Geffroy, B.; Raimond, P.

    2006-01-01

    The weak absorption of the photoactive layer appears as a one of the main factors limiting organic photovoltaic solar cells performances. In order to increase the interaction of the incident light with the photoactive materials, we investigate the effect of a periodic patterning of the solar cells surface with microstructures in the optical wavelength scale. In this aim, we present an original all optical patterning technique of polymer films. The method is based on a laser controlled mass transport in azopolymer films leading to efficient deformation of the film surface in conjunction with the incoming light interference pattern. The technique is used to pattern one-dimensional gratings on the surface of solar cells. In the work presented here, the cell photoactive material is based on the interpenetrated network of a conjugated donor polymer and a fullerene derivative. The cells investigated are illuminated in a reverse configuration through a semi-transparent top cathode. The effect of the periodic structures onto the incident light propagation has been investigated through optical characterizations. We demonstrate that a part of the incident light can be trapped inside the solar cell layers due to diffraction onto the periodic structures

  18. Chalcogenide glass-ceramic with self-organized heterojunctions: application to photovoltaic solar cells

    Science.gov (United States)

    Zhang, Xianghua; Korolkov, Ilia; Fan, Bo; Cathelinaud, Michel; Ma, Hongli; Adam, Jean-Luc; Merdrignac, Odile; Calvez, Laurent; Lhermite, Hervé; Brizoual, Laurent Le; Pasquinelli, Marcel; Simon, Jean-Jacques

    2018-03-01

    In this work, we present for the first time the concept of chalcogenide glass-ceramic for photovoltaic applications with the GeSe2-Sb2Se3-CuI system. It has been demonstrated that thin films, deposited with the sputtering technique, are amorphous and can be crystallized with appropriate heat treatment. The thin film glass-ceramic behaves as a p-type semiconductor, even if it contains p-type Cu2GeSe3 and n-type Sb2Se3. The conductivity of Sb2Se3 has been greatly improved by appropriate iodine doping. The first photovoltaic solar cells based on the association of iodine-doped Sb2Se3 and the glass-ceramic thin films give a short-circuit current density JSC of 10 mA/cm2 and an open-circuit voltage VOC of 255 mV, with a power conversion efficiency of about 0.9%.

  19. Grid parity. Holy Grail or hype? Photovoltaic solar electricity on its way to competitiveness

    International Nuclear Information System (INIS)

    Sinke, W.C.

    2009-05-01

    Solar energy has a huge global and European potential for sustainable generation of electricity, heat and fuels. Photovoltaic solar energy conversion (PV) and concentrating solar power (CSP) are the two options for electricity generation. In the longer term they may also be used to generate sustainable fuel, especially hydrogen, if that would turn out to be useful in the total energy mix. Because of the different nature of the PV and CSP conversion processes and the related distinctive features, they can be considered largely complementary Clearly, the combination of the two absolutely makes a winning team and may form (or even has to form) the basis of our future sustainable energy system. Grid parity is a rather simplified indicator of the competitiveness of PV. It is nevertheless very useful since it assumes the viewpoint of a potential investor in a PV system and has thus helped to define potential markets. Moreover the concept does roughly illustrate how long it takes PV to reach competitiveness in different segments of the electricity market. It may not be the Holy Grail but it is certainly no hype either. When used with care it is one key to the success of PV.

  20. Chalcogenide glass-ceramic with self-organized heterojunctions: application to photovoltaic solar cells

    Directory of Open Access Journals (Sweden)

    Zhang Xianghua

    2018-01-01

    Full Text Available In this work, we present for the first time the concept of chalcogenide glass-ceramic for photovoltaic applications with the GeSe2–Sb2Se3–CuI system. It has been demonstrated that thin films, deposited with the sputtering technique, are amorphous and can be crystallized with appropriate heat treatment. The thin film glass-ceramic behaves as a p-type semiconductor, even if it contains p-type Cu2GeSe3 and n-type Sb2Se3. The conductivity of Sb2Se3 has been greatly improved by appropriate iodine doping. The first photovoltaic solar cells based on the association of iodine-doped Sb2Se3 and the glass-ceramic thin films give a short-circuit current density JSC of 10 mA/cm2 and an open-circuit voltage VOC of 255 mV, with a power conversion efficiency of about 0.9%.

  1. Design and experimental investigation of a Multi-segment plate concentrated photovoltaic solar energy system

    International Nuclear Information System (INIS)

    Wang, Gang; Chen, Zeshao; Hu, Peng

    2017-01-01

    Highlights: • A multi-segment plate concentrated photovoltaic solar energy system was proposed. • A prototype of this new concentrator was developed for experimental investigation. • Experimental investigation results showed a good concentrating uniformity. - Abstract: Solar energy is one of the most promising renewable energies and meaningful for the sustainable development of energy source. A multi-segment plate concentrated photovoltaic (CPV) solar power system was proposed in this paper, the design principle of the multi-segment plate concentrator of this solar power system was given, which could provide uniform solar radiation flux density distribution on solar cells. A prototype of this multi-segment plate CPV solar power system was developed for the experimental study, aiming at the investigations of solar radiation flux density distribution and PV performances under this concentrator design. The experimental results showed that the solar radiation flux density distribution provided by the multi-segment plate concentrator had a good uniformity, and the number and temperature of solar cells both influence the photoelectric transformation efficiency of the CPV solar power system.

  2. On-line energy and battery thermal management for hybrid electric heavy-duty truck

    NARCIS (Netherlands)

    Pham, H.T.; Kessels, J.T.B.A.; Bosch, van den P.P.J.; Huisman, R.G.M.; Nevels, R.M.P.A.

    2013-01-01

    This paper discusses an integrated approach for energy and thermal management to minimize the fuel consumption of a hybrid electric heavy-duty truck. Conventional Energy Management Systems (EMS) operate separately from the Battery Thermal Management System (BTMS) in Hybrid Electric Vehicles (HEVs).

  3. Simultaneous thermal analysis and thermodilatometry of hybrid fiber reinforced UHPC

    Science.gov (United States)

    Scheinherrová, Lenka; Fořt, Jan; Pavlík, Zbyšek; Černý, Robert

    2017-07-01

    Development of concrete technology and the availability of variety of materials such as silica fume, mineral microfillers and high-range water-reducing admixtures make possible to produce Ultra-High Performance Concrete (UHPC) with compressive strength higher than 160 MPa. However, UHPC is prone to spall under high temperatures what limits its use for special applications only, such as offshore and marine structures, industrial floors, security barriers etc. The spalling is caused by the thermal stresses due to the temperature gradient during heating, and by the splitting force owing to the release of water vapour. Hybrid fibre reinforcement based on combination of steel and polymer fibres is generally accepted by concrete community as a functional solution preventing spalling. In this way, Ultra-High Performance Fibre Reinforced Concrete (UHPFRC) is produced possessing high mechanical strength, durability and resistance to water and salt ingress. Since UHPFRC find use in construction industry in tunnel linings, precast tunnel segments, and high-rise buildings, its behaviour during the high-temperature exposure and its residual parameters are of the particular importance. On this account, Simultaneous Thermal Analysis (STA) and Thermodilatometry Analysis (TDA) were done in the paper to identify the structural and chemical changes in UHPFRC during its high-temperature load. Based on the experimental results, several physical and chemical processes that studied material underwent at high-temperatures were recognized. The obtained data revealed changes in the composition of the studied material and allowed identification of critical temperatures for material damage.

  4. Exergetic evaluation on photovoltaic/thermal hybrid panel; Taiyoko netsu hybrid panel no exergy hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Iwaki, H; Morita, Y; Fujisawa, T; Tani, T [Science University of Tokyo, Tokyo (Japan)

    1996-10-27

    The photovoltaic/thermal hybrid panel (PV/T) is an energy converter that was designed for the composite use of electricity and heat. In this paper, the validity of PV/T designed for trial was evaluated based on an exergetic theory. As the result of an experiment, the electric exergetic value of PV/T and PV is each 65.8 kWh/m{sup 2} and 58.6 kWh/m{sup 2}. The former is higher than the latter by 11.2%. The total exergetic value of PV/T is also 1.2 and 8.2 times as high as those of a PV and solar collector (SC), respectively. The calculation result of the optimum temperature operation showed that the exergetic value of PV/T is 3.1 times as high as the electric exergetic value. Therefore, the operation must be performed with the electric and thermal exergetic values set in a ratio of 3.1 to 1. In this paper, the operating mode is handled in which importance was more attached to the electric exergy than the thermal exergy. The flow rate of a heating medium on PV/T is not thus the flow control that maximizes the PV/T exergy. In the future, studies including these points will be promoted. 7 refs., 7 figs., 3 tabs.

  5. Thermal management of hybrid vehicles. Challenges and solutions; Thermomanagement von Hybridfahrzeugen. Herausforderungen und Loesungen

    Energy Technology Data Exchange (ETDEWEB)

    Heckenberger, T. [Behr GmbH und Co. KG, Stuttgart (Germany)

    2007-10-15

    Higher thermal management demands are placed on hybrid vehicles than on conventional vehicles. The thermal comfort of the passengers must be assured when the combustion engine shuts down, i.e. during start-stop phases and during purely electric driving. Likewise, the particular hybrid modules and components must be cooled to temperature levels that are too low for conventional cooling circuits. Behr is presently developing cooling and climate control systems for all three types of hybrid vehicles: micro-, mild, and full hybrids. (orig.)

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

    International Nuclear Information System (INIS)

    Agrawal, Sanjay; Tiwari, G.N.

    2013-01-01

    Highlights: ► Comparative study of PVT air collectors. ► CO 2 analysis of all type of PVT air collectors. ► Study of thermal energy, exergy gain and exergy efficiency. ► Exergy efficiency of unglazed hybrid PVT tiles air collector is most efficient. - Abstract: In this paper, comparative analysis of different type of photovoltaic thermal (PVT) air collector namely: (i) unglazed hybrid PVT tiles, (ii) glazed hybrid PVT tiles and (iii) conventional hybrid PVT air collectors have been carried out for the composite climate of Srinagar (India). The comparative study has been carried out in terms of overall thermal energy and exergy gain, exergy efficiency and carbon credit earned by different type of hybrid PVT air collectors. It has been observed that overall annual thermal energy and exergy gain of unglazed hybrid PVT tiles air collector is higher by 27% and 29.3% respectively as compared to glazed hybrid PVT tiles air collector and by 61% and 59.8% respectively as compared to conventional hybrid PVT air collector. It has also been observed that overall annual exergy efficiency of unglazed and glazed hybrid PVT tiles air collector is higher by 9.6% and 53.8% respectively as compared to conventional hybrid PVT air collector. On the basis of comparative study, it has been concluded that CO 2 emission reduction per annum on the basis of overall thermal energy gain of unglazed and glazed hybrid PVT tiles air collector is higher by 62.3% and 27.7% respectively as compared to conventional hybrid PVT air collector and on the basis of overall exergy gain it is 59.7% and 22.7%.

  7. Analysis and optimization of hybrid electric vehicle thermal management systems

    Science.gov (United States)

    Hamut, H. S.; Dincer, I.; Naterer, G. F.

    2014-02-01

    In this study, the thermal management system of a hybrid electric vehicle is optimized using single and multi-objective evolutionary algorithms in order to maximize the exergy efficiency and minimize the cost and environmental impact of the system. The objective functions are defined and decision variables, along with their respective system constraints, are selected for the analysis. In the multi-objective optimization, a Pareto frontier is obtained and a single desirable optimal solution is selected based on LINMAP decision-making process. The corresponding solutions are compared against the exergetic, exergoeconomic and exergoenvironmental single objective optimization results. The results show that the exergy efficiency, total cost rate and environmental impact rate for the baseline system are determined to be 0.29, ¢28 h-1 and 77.3 mPts h-1 respectively. Moreover, based on the exergoeconomic optimization, 14% higher exergy efficiency and 5% lower cost can be achieved, compared to baseline parameters at an expense of a 14% increase in the environmental impact. Based on the exergoenvironmental optimization, a 13% higher exergy efficiency and 5% lower environmental impact can be achieved at the expense of a 27% increase in the total cost.

  8. Competitiveness Level of Photovoltaic Solar Systems in Ouagadougou (Burkina Faso: Study Based on the Domestic Electric Meters Calibration

    Directory of Open Access Journals (Sweden)

    Konan Lambert Amani

    2016-01-01

    Full Text Available The mean cost price of electricity in Burkina Faso at the end of the last quarter of 2012 was 158 FCFA/kWh for a country where more than 46% of the population lives below the national poverty threshold. To look for solution to that problem, the resort to photovoltaic solar energy is justified for that country. The purpose of this study is to promote the integration of both technical and economical surveys in solar energy preliminary projects in Ouagadougou. To reach that, investigations were carried out in some households and attention was paid from the calibration of the domestic electric meters. Energy demands collected within each household allow us to design a corresponding solar kit through optimization rules. An estimate was edited and financial viability study for each household was also carried out thereafter. In this study, only households using the national electricity network calibration meter on their disadvantage favorably answered to all financial indicators and appear as the only one that could profit from such project. This work is helpful to note that photovoltaic solar energy still stays at a primitive level of competitiveness compared to conventional energy resources for small systems in Ouagadougou.

  9. [The property and applications of the photovoltaic solar panel in the region of diagnostic X-ray].

    Science.gov (United States)

    Hirota, Jun'ichi; Tarusawa, Kohetsu; Kudo, Kohsei

    2010-10-20

    In this study, the sensitivity in the diagnostic X-ray region of the single crystalline Si photovoltaic solar panel, which is expected to grow further, was measured by using an X-ray tube. The output voltage of the solar panel was clearly proportional to the tube voltage and a good time response in the irradiation time setting of the tube was measured. The factor which converts measured voltage to irradiation dose was extracted experimentally using a correction filter to investigate the ability of the solar panel as a dose monitor. The obtained conversion factors were N(S) = 13 ± 1[µV/µSv/s] for the serial and N(P) = 58 ± 2[µV/µSv/s] for the parallel connected solar panels, both with the Al 1 mm + Cu 0.1 mm correction filter, respectively. Therefore, a good dose dependence of the conversion factor was confirmed by varying the distance between the X-ray tube and the solar panel with that filter. In conclusion, a simple extension of our results pointed out the potential of a new concept of measurements using, for example, the photovoltaic solar panel, the direct dose measurement from X-ray tube and real time estimation of the exposed dose in IVR.

  10. Optical and thermal response of single-walled carbon nanotube–copper sulfide nanoparticle hybrid nanomaterials

    International Nuclear Information System (INIS)

    Tseng, Yi-Hsuan; He Yuan; Que Long; Lakshmanan, Santana; Yang Chang; Chen Wei

    2012-01-01

    This paper reports the optical and thermal response of a single-walled carbon nanotube–copper sulfide nanoparticle (SWNT–CuS NP) hybrid nanomaterial and its application as a thermoelectric generator. The hybrid nanomaterial was synthesized using oleylamine molecules as the linker molecules between SWNTs and CuS NPs. Measurements found that the hybrid nanomaterial has significantly increased light absorption (up to 80%) compared to the pure SWNT. Measurements also found that the hybrid nanomaterial thin-film devices exhibit a clear optical and thermal switching effect, which can be further enhanced up to 10 × by asymmetric illumination of light and thermal radiation on the thin-film devices instead of symmetric illumination. A simple prototype thermoelectric generator enabled by the hybrid nanomaterials is demonstrated, indicating a new route for achieving thermoelectricity. (paper)

  11. Performance of a thermal imager employing a hybrid pyroelectric detector array with MOSFET readout

    International Nuclear Information System (INIS)

    Watton, R.; Mansi, M.V.

    1988-01-01

    A thermal imager employing a two-dimensional hybrid array of pyroelectric detectors with MOSFET readout has been built. The design and theoretical performance of the detector are discussed, and the results of performance measurements are presented. 8 references

  12. Chip Integrated, Hybrid EHD/Capillary Driven Thermal Management System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Chip-Integrated, Hybrid EHD/Capillary-Driven Thermal Management System is a two year that will leverage independently attained yet related prototype hardware...

  13. Analysis of Heat Transfer in Power Split Device for Hybrid Electric Vehicle Using Thermal Network Method

    Directory of Open Access Journals (Sweden)

    Jixin Wang

    2014-06-01

    Full Text Available This paper presents a rational prediction of temperature field on the differential hybrid system (DHS based on the thermal network method (TNM. The whole thermal network model is built by considering both the contact thermal resistance between gasket and planet gear and the temperature effect on the physical property parameters of lubricant. The contact thermal resistance is obtained by using the concept of contact branch thermal resistance and G-W elastic model. By building an elaborate thermal network model and computing models for power losses and thermal resistances between components, the whole temperature field of DHS under typical operating condition is predicted. Results show that thermal network method can be effectively used to predict the temperature distribution and the rule of temperature variation, the surface roughness significantly affects contact thermal conduction, and the decrease in the thermal resistance of the natural convection between air and DHS housing can effectively improve the thermal environment of DHS.

  14. An Approach for Designing Thermal Management Systems for Electric and Hybrid Vehicle Battery Packs

    International Nuclear Information System (INIS)

    Pesaran, Ahmad A.; Keyser, Matthew; Burch, Steve

    1999-01-01

    If battery packs for electric vehicles (EVs) and hybrid electric vehicles (HEVs) are to operate effectively in all climates, thermal management of the packs is essential. In this paper, we will review a systematic approach for designing and evaluating battery pack thermal management systems. A thermal management system using air as the heat transfer medium is less complicated than a system using liquid cooling/heating. Generally, for parallel HEVs, an air thermal management system is adequate, whereas for EVs and series HEVs, liquid-based systems may be required for optimum thermal performance. Further information on battery thermal management can be found on the Web site www.ctts.nrel.gov/BTM

  15. Thermal properties of oil palm nano filler/kenaf reinforced epoxy hybrid nanocomposites

    Science.gov (United States)

    Saba, N.; Paridah, M. T.; Abdan, K.; Ibrahim, N. A.

    2016-11-01

    The aim of this research study was to fabricate nano oil palm empty fruit bunch (OPEFB)/kenaf/epoxy hybrid nanocomposites and to make comparative study on the thermal properties of nano OPEFB/kenaf/epoxy hybrid nanocomposites with the montmorillonite (MMT)/kenaf/epoxy hybrid nanocomposites and organically modified MMT (OMMT)/kenaf/epoxy hybrid nanocomposites. Epoxy based kenaf hybrid nanocomposites was prepared by dispersing the nano filler (nano OPEFB filler, MMT, OMMT) at 3% loading through high speed mechanical stirrer followed by hand lay-up technique. Thermal properties of hybrid nanocomposites were analyzed through thermogravimetry analyzer (TGA), and differential scanning calorimetry (DSC). Obtained results specified that addition of nano OPEFB filler improves the thermal stability and char yield of kenaf/epoxy composites. Furthermore, the increase in decomposition temperature by the nano OPEFB filler was quite comparable to the MMT/kenaf/epoxy but relatively less than OMMT/kenaf/epoxy hybrid nanocomposites. We concluded from overall consequences that the nano OPEFB filler can be used as the promising and innovative alternative of existing expensive nano filler, with relatively lesser impact on the environment having marked pronounced impact on the construction, automotive, aerospace, electronics and semiconducting sectors as future industries based on bio-wastes with satisfactory light weight and thermal stability on other side.

  16. Fabrication and performance analysis of 4-sq cm indium tin oxide/InP photovoltaic solar cells

    Science.gov (United States)

    Gessert, T. A.; Li, X.; Phelps, P. W.; Coutts, T. J.; Tzafaras, N.

    1991-01-01

    Large-area photovoltaic solar cells based on direct current magnetron sputter deposition of indium tin oxide (ITO) into single-crystal p-InP substrates demonstrated both the radiation hardness and high performance necessary for extraterrestrial applications. A small-scale production project was initiated in which approximately 50 ITO/InP cells are being produced. The procedures used in this small-scale production of 4-sq cm ITO/InP cells are presented and discussed. The discussion includes analyses of performance range of all available production cells, and device performance data of the best cells thus far produced. Additionally, processing experience gained from the production of these cells is discussed, indicating other issues that may be encountered when large-scale productions are begun.

  17. Investigation on the effect of thermal resistances on a highly concentrated photovoltaic-thermoelectric hybrid system

    International Nuclear Information System (INIS)

    Zhang, Jin; Xuan, Yimin

    2016-01-01

    Highlights: • The highly concentrated PV-TE hybrid system is studied. • The performances of different cooling systems are analyzed and compared. • Sandwiching a copper plate between the PV and TE can improve the efficiency. • Four thermal design principles of the system are proposed. - Abstract: A thermal analysis of a highly concentrated photovoltaic-thermoelectric (PV-TE) hybrid system is carried out in this paper. Both the output power and the temperature distribution in the hybrid system are calculated by means of a three-dimensional numerical model. Three possible approaches for designing the highly concentrated PV-TE hybrid system are presented by analyzing the thermal resistance of the whole system. First, the sensitivity analysis shows that the thermal resistance between the TE module and the environment has a more great effect on the output power than the thermal resistance between the PV and the TE. The influence of the natural convection and the radiation can be ignored for the highly concentrated PV-TE hybrid system. Second, it is necessary to sandwich a copper plate between the PV and the TE for decreasing the thermal resistance between the PV and the TE. The role of the copper plate is to improve the temperature uniformity. Third, decreasing the area of PV cells can improve the efficiency of the highly concentrated PV-TE hybrid system. It should be pointed out that decreasing the area of PV cells also increases the total thermal resistance, but the raise of the efficiency is caused by the reduction of the heat transfer rate of the system. Therefore, the principle of minimizing the total thermal resistance may not be suitable for optimizing the area of PV cells.

  18. Thermal modeling of a hydraulic hybrid vehicle transmission based on thermodynamic analysis

    International Nuclear Information System (INIS)

    Kwon, Hyukjoon; Sprengel, Michael; Ivantysynova, Monika

    2016-01-01

    Hybrid vehicles have become a popular alternative to conventional powertrain architectures by offering improved fuel efficiency along with a range of environmental benefits. Hydraulic Hybrid Vehicles (HHV) offer one approach to hybridization with many benefits over competing technologies. Among these benefits are lower component costs, more environmentally friendly construction materials, and the ability to recover a greater quantity of energy during regenerative braking which make HHVs partially well suited to urban environments. In order to further the knowledge base regarding HHVs, this paper explores the thermodynamic characteristics of such a system. A system model is detailed for both the hydraulic and thermal components of a closed circuit hydraulic hybrid transmission following the FTP-72 driving cycle. Among the new techniques proposed in this paper is a novel method for capturing rapid thermal transients. This paper concludes by comparing the results of this model with experimental data gathered on a Hardware-in-the-Loop (HIL) transmission dynamometer possessing the same architecture, components, and driving cycle used within the simulation model. This approach can be used for several applications such as thermal stability analysis of HHVs, optimal thermal management, and analysis of the system's thermodynamic efficiency. - Highlights: • Thermal modeling for HHVs is introduced. • A model for the hydraulic and thermal system is developed for HHVs. • A novel method for capturing rapid thermal transients is proposed. • The thermodynamic system diagram of a series HHV is predicted.

  19. Enhanced Thermal Management System for Spent Nuclear Fuel Dry Storage Canister with Hybrid Heat Pipes

    International Nuclear Information System (INIS)

    Jeong, Yeong Shin; Bang, In Cheol

    2016-01-01

    Dry storage uses the gas or air as coolant within sealed canister with neutron shielding materials. Dry storage system for spent fuel is regarded as relatively safe and emits little radioactive waste for the storage, but it showed that the storage capacity and overall safety of dry cask needs to be enhanced for the dry storage cask for LWR in Korea. For safety enhancement of dry cask, previous studies of our group firstly suggested the passive cooling system with heat pipes for LWR spent fuel dry storage metal cask. As an extension, enhanced thermal management systems for the spent fuel dry storage cask for LWR was suggested with hybrid heat pipe concept, and their performances were analyzed in thermal-hydraulic viewpoint in this paper. In this paper, hybrid heat pipe concept for dry storage cask is suggested for thermal management to enhance safety margin. Although current design of dry cask satisfies the design criteria, it cannot be assured to have long term storage period and designed lifetime. Introducing hybrid heat pipe concept to dry storage cask designed without disrupting structural integrity, it can enhance the overall safety characteristics with adequate thermal management to reduce overall temperature as well as criticality control. To evaluate thermal performance of hybrid heat pipe according to its design, CFD simulation was conducted and previous and revised design of hybrid heat pipe was compared in terms of temperature inside canister

  20. Characterization of Alternative Hybrid Solar Thermal Electric Systems

    International Nuclear Information System (INIS)

    Williams, T.A.

    1999-01-01

    Hybrid power towers offer a number of advantages over solar-only power tower systems for early commercial deployment of the technology. These advantages include enhanced modularity, reduced financial and technical risks, and lower energy costs. With the changes in the domestic and world markets for bulk power, hybrid power towers are likely to have the best opportunities for power projects. This paper discusses issues that are likely to be important to the deployment of hybrid power towers in the near future. A large number of alternative designs are possible, and it is likely that there is no single approach that can be considered best or optimal for all project opportunities. The preferred design will depend on the application, as well as the unique objectives and perspectives of the person evaluating the design

  1. High thermal performance lithium-ion battery pack including hybrid active–passive thermal management system for using in hybrid/electric vehicles

    International Nuclear Information System (INIS)

    Fathabadi, Hassan

    2014-01-01

    In this study, a novel Li-ion battery pack design including hybrid active–passive thermal management system is presented. The battery pack is suitable for using in hybrid/electric vehicles. Active part of the hybrid thermal management system uses distributed thin ducts, air flow and natural convection as cooling media while the passive part utilizes phase change material/expanded graphite composite (PCM/EG) as cooling/heating component to optimize the thermal performance of the proposed battery pack. High melting enthalpy of PCM/EG composite together with melting of PCM/EG composite at the temperature of 58.9 °C remains the temperature distribution of the battery units in the desired temperature range (below 60 °C). The temperature and voltage distributions in the proposed battery pack design consisting of battery units, distributed thin ducts and PCM/EG composite are calculated by numerical solving of the related partial differential equations. Simulation results obtained by writing M-files code in Matlab environment and plotting the numerical data are presented to validate the theoretical results. A comparison between the thermal and physical characteristics of the proposed battery pack and other latest works is presented that explicitly proves the battery pack performance. - Highlights: • Novel Li-ion battery pack including active and passive thermal management systems. • The battery pack has high thermal performance for ambient temperatures until 55 °C. • Uniform temperature and voltage distributions. • The maximum observed temperature in each battery unit is less than other works. • The maximum temperature dispersion in each battery is less than other works

  2. Thermal resistance analysis and optimization of photovoltaic-thermoelectric hybrid system

    International Nuclear Information System (INIS)

    Yin, Ershuai; Li, Qiang; Xuan, Yimin

    2017-01-01

    Highlights: • A detailed thermal resistance analysis of the PV-TE hybrid system is proposed. • c-Si PV and p-Si PV cells are proved to be inapplicable for the PV-TE hybrid system. • Some criteria for selecting coupling devices and optimal design are obtained. • A detailed process of designing the practical PV-TE hybrid system is provided. - Abstract: The thermal resistance theory is introduced into the theoretical model of the photovoltaic-thermoelectric (PV-TE) hybrid system. A detailed thermal resistance analysis is proposed to optimize the design of the coupled system in terms of optimal total conversion efficiency. Systems using four types of photovoltaic cells are investigated, including monocrystalline silicon photovoltaic cell, polycrystalline silicon photovoltaic cell, amorphous silicon photovoltaic cell and polymer photovoltaic cell. Three cooling methods, including natural cooling, forced air cooling and water cooling, are compared, which demonstrates a significant superiority of water cooling for the concentrating photovoltaic-thermoelectric hybrid system. Influences of the optical concentrating ratio and velocity of water are studied together and the optimal values are revealed. The impacts of the thermal resistances of the contact surface, TE generator and the upper heat loss thermal resistance on the property of the coupled system are investigated, respectively. The results indicate that amorphous silicon PV cell and polymer PV cell are more appropriate for the concentrating hybrid system. Enlarging the thermal resistance of the thermoelectric generator can significantly increase the performance of the coupled system using amorphous silicon PV cell or polymer PV cell.

  3. Design and Research of the Movable Hybrid Photovoltaic-Thermal (PVT System

    Directory of Open Access Journals (Sweden)

    Lian Zhang

    2017-04-01

    Full Text Available In recent years, with the development of photovoltaic system and photo-thermal system technology, hybrid photovoltaic-thermal (PVT technology has been a breakthrough in many aspects. This paper describes the movable hybrid PVT system from the aspects of appearance structure, energy flow, and control circuit. The system is equipped with rolling wheels and the simulated light sources also can be removed so that the system can be used in the outdoor conditions. The movable system is also suitable for the PVT system and its related applications without any external power supply. This system combines two technologies: photovoltaic power generation and photo-thermal utilization. The first part of the power supply is for the systems own output power supply, and the second part is for generating thermal energy. The two separate parts can be controlled and monitored respectively through the control circuits and the touch screens. The experimental results show that the system can generate 691 kWh electric energy and 3047.8 kWh thermal energy each year under normal working conditions. The efficiency of the proposed movable hybrid PVT system is calculated to be approximately 42.82% using the revised equations that are proposed in this paper. Therefore, the movable hybrid PVT system can meet the daily demands of hot water and electricity power in remote areas or islands and other non-grid areas. It also can be used to conduct experiment tests for the PVT system.

  4. Influence of Hybrid Fillers on Thermal Conductivity of Nylon-6/Graphene Composites

    Directory of Open Access Journals (Sweden)

    SONG Na

    2018-03-01

    Full Text Available The thermal insulating properties of polymer greatly restrict the application of polymer as the thermal conductivity materials in industry. Multilayer graphene was chosen as a filler due to its unique thermal transfer property. The effect of alumina oxide (Al2O3 and silicon carbide (SiC with graphene as hybrid fillers on thermal conductivity of polymers was also explored. The thermal conductivity of the composites enhances 161% with 3%(mass fraction graphene content compared to pure nylon-6(PA6. The thermal conductivity of PA6 composites is within 0.653-4.307W·m-1·K-1 by adjusting hybrid fillers content and the ratio of graphene with Al2O3 and SiC. The best thermal conductivity is 20 times higher than the pure PA6. It is no doubt that the exploration can provide valuable experimental basis for extending the utilization of graphene as thermal conductivity filler and the application of PA6 thermal conductivity materials in industry.

  5. 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.

  6. Novel thermal management structures and their applications in new hybrid technologies and feed-through structures

    International Nuclear Information System (INIS)

    Carter, A.A.; Oliveira, R. de; Gandi, A.

    1999-01-01

    Novel techniques are described for fabricating a new thermal management structure (TMS), in the form of rigid low-mass structures with extremely high in-plane thermal conductivity. The core materials can be forms of thermally anisotropically conducting pyrolytic graphite that are directly encapsulated in a new thin-layering process. The structures can be used in a large variety of applications, including: (a) Efficient interfacing with ceramic materials and metals to provide new thermal management technologies. (b) Providing the source for a new hybrid technology where low-mass custom-designed multilayer thin-film circuits can be directly processed onto such structures. Alternatively, having been prefabricated on an independent substrate, hybrids can be efficiently interfaced to such thermal management structures. (c) Providing electrical connectivity between both sides of a TMS board through a new feedthrough technology that allows the fabrication of both single-sided and double-sided hybrids. These thermal management techniques and their applications are the subject of an international patent application number PCT/GB99/02180, filed in the names of the European Organization for Nuclear Research and Queen Mary and Westfield College, London. (orig.)

  7. Time series analysis of infrared satellite data for detecting thermal anomalies: a hybrid approach

    Science.gov (United States)

    Koeppen, W. C.; Pilger, E.; Wright, R.

    2011-07-01

    We developed and tested an automated algorithm that analyzes thermal infrared satellite time series data to detect and quantify the excess energy radiated from thermal anomalies such as active volcanoes. Our algorithm enhances the previously developed MODVOLC approach, a simple point operation, by adding a more complex time series component based on the methods of the Robust Satellite Techniques (RST) algorithm. Using test sites at Anatahan and Kīlauea volcanoes, the hybrid time series approach detected ~15% more thermal anomalies than MODVOLC with very few, if any, known false detections. We also tested gas flares in the Cantarell oil field in the Gulf of Mexico as an end-member scenario representing very persistent thermal anomalies. At Cantarell, the hybrid algorithm showed only a slight improvement, but it did identify flares that were undetected by MODVOLC. We estimate that at least 80 MODIS images for each calendar month are required to create good reference images necessary for the time series analysis of the hybrid algorithm. The improved performance of the new algorithm over MODVOLC will result in the detection of low temperature thermal anomalies that will be useful in improving our ability to document Earth's volcanic eruptions, as well as detecting low temperature thermal precursors to larger eruptions.

  8. Enhanced Thermal Conductivity of Polyimide Composites Filled with Modified h-BN and Nanodiamond Hybrid Filler.

    Science.gov (United States)

    Yang, Xi; Yu, Xiaoyan; Naito, Kimiyoshi; Ding, Huili; Qu, Xiongwei; Zhang, Qingxin

    2018-05-01

    A new thermally conductive and electrically insulative polyimide were prepared by filling different amounts of hexagonal boron nitride (h-BN) particles, and the thermal conductivity of Polyimide (PI) composites were improved with the increasing h-BN content. Based on this, two methods were applied to improve thermal conductivity furtherly at limited filler loading in this paper. One is modifying the h-BN to improve interface interaction, another is fabricating a nano-micro hybrid filler with 2-D h-BN and 0-D nano-scale nanodiamond (ND) to build more effective conductive network. Both surface modification and hybrid system have a positive effect on thermal conductivity. The composites introducing 40 wt% hybrid filler (the weight ratio of ND/modified BN was 1/10) showed the highest thermal conductivity, being up to 0.98 W/(m K) (5.2 times that of PI). In addition, the composites exhibits excellent electrical insulation, thermal stability properties etc.

  9. Magnetic properties and thermal stability of MnBi/NdFeB hybrid bonded magnets

    International Nuclear Information System (INIS)

    Cao, S.; Yue, M.; Yang, Y. X.; Zhang, D. T.; Liu, W. Q.; Zhang, J. X.; Guo, Z. H.; Li, W.

    2011-01-01

    Magnetic properties and thermal stability were investigated for the MnBi/NdFeB (MnBi = 0, 20, 40, 60, 80, and 100 wt.%) bonded hybrid magnets prepared by spark plasma sintering (SPS) technique. Effect of MnBi content on the magnetic properties of the hybrid magnets was studied. With increasing MnBi content, the coercivity of the MnBi/NdFeB hybrid magnets increases rapidly, while the remanence and maximum energy product drops simultaneously. Thermal stability measurement on MnBi magnet, NdFeB magnet, and the hybrid magnet with 20 wt.% MnBi indicates that both the NdFeB magnet and the MnBi/NdFeB hybrid magnet have a negative temperature coefficient of coercivity, while the MnBi magnet has a positive one. The (BH) max of the MnBi/NdFeB magnet (MnBi = 20 wt.%) is 5.71 MGOe at 423 K, which is much higher than 3.67 MGOe of the NdFeB magnet, indicating a remarkable improvement of thermal stability.

  10. Integrated energy and advanced thermal management system for hybrid electric vehicles

    NARCIS (Netherlands)

    Wei, C.

    2017-01-01

    Hybrid electric vehicles (HEVs) featuring a fuel source engine and an energy storage source battery play an important role in improving fuel efficiency compared with its conventional counterparts. In view of the drawbacks of the existing research neglecting the thermal aspects when it comes to

  11. A new hybrid thermal comfort guideline for the Netherlands : Background and development

    NARCIS (Netherlands)

    Boerstra, A.C.; Van Hoof, J.; Van Weele, A.M.

    2015-01-01

    In 2004, the first adaptive thermal comfort guideline was introduced in the Netherlands. Recently, a new, upgraded version of this ISSO 74 (ATG) guideline has been developed. The new requirements are hybrid in nature as the 2014 version of the guideline combines elements of traditional non-adaptive

  12. Coupled thermal model of photovoltaic-thermoelectric hybrid panel for sample cities in Europe

    DEFF Research Database (Denmark)

    Rezaniakolaei, Alireza; Sera, Dezso; Rosendahl, Lasse Aistrup

    2016-01-01

    of the hybrid system under different weather conditions. The model takes into account solar irradiation, wind speed and ambient temperature as well as convective and radiated heat losses from the front and rear surfaces of the panel. The model is developed for three sample cities in Europe with different......In general, modeling of photovoltaic-thermoelectric (PV/TEG) hybrid panels have been mostly simplified and disconnected from the actual ambient conditions and thermal losses from the panel. In this study, a thermally coupled model of PV/TEG panel is established to precisely predict performance...... weather conditions. The results show that radiated heat loss from the front surface and the convective heat loss due to the wind speed are the most critical parameters on performance of the hybrid panel performance. The results also indicate that, with existing thermoelectric materials, the power...

  13. Solar warming systems of water installed in Colombia. Photovoltaic solar systems installed in the Country

    International Nuclear Information System (INIS)

    Rodriguez P, F.

    1995-01-01

    Between the systems that operate as of solar energy, the solar collectors to heat water have had wide use and application in the Country. Basically, a solar collector is constituted by: Box, thermal insulator, ducts and transparent roof. Generally, the used materials are the following: As thermal insulator: Polyurethane or glass fiber; as absorbent plate: Copper or aluminum, painting in dull black or selective surfaces; for the ducts: Generally it is used copper pipeline; and for the cover: Common glass or temperate glass

  14. 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.

  15. 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.

  16. Rural electrification with photovoltaic solar technology using solar home system; Eletrificacao rural com tecnologia solar fotovoltaica utilizando sistemas isolados autonomos

    Energy Technology Data Exchange (ETDEWEB)

    Salviano, Carlos Jose Caldas

    1999-02-01

    The utilization of solar energy, inexhaustible on the earthly scale of time, as heat and light source, today is one of the energetics alternatives more to confront the challenges of the new millennium. Remarkable is the impulse that power generation photovoltaic has received in Brazil. In Pernambuco, state of Brazil, the CELPE - Electric Power Company of Pernambuco, already implanted more than 750 photovoltaic solar home system (95 kW installed) for power supply to rural communities far from the grid connection that come across in commercial operation since 1994. Eight configurations were studied with modifications in their components (panel, battery and charge) with the objective to evaluate the performance and the adequacy of the size these configurations. The parameters utilized for this evaluation were: solar energy diary incident on the panel plat, diary efficiency generator, output voltage on the generator and state of charge the batteries bank. A system of data acquisition automated was fined to measure in real conditions the function of each components, the following parameters: solar radiation incident and temperature on the photovoltaic generator, voltage and generator current, batteries bank and charge and ambient temperature. About the configurations studied, it follows that analysis the operational of characteristics capacity and battery capacity of the SHS utilized, simulating the rural electrification conditions. It was possible to certify the adequate configurations for the load profile will be supply. (author)

  17. Photovoltaic solar system connected to the electric power grid operating as active power generator and reactive power compensator

    Energy Technology Data Exchange (ETDEWEB)

    Albuquerque, F.L.; Moraes, A.J.; Guimaraes, G.C.; Sanhueza, S.M.R.; Vaz, A.R. [Federal University of Uberlandia (UFU), MG (Brazil)

    2009-07-01

    In the case of photovoltaic solar systems (PV) acting as a distributed generation (DG), the DC energy obtained is fed through the power-conditioning unit (inverter) to the grid. The majority of contemporary inverters used in DG systems are current source inverters (CSI) operating at unity power factor. If, however, we assume that voltage source inverters (VSI) can be utilized instead of CSI, we can generate reactive power commensurate with the remaining unused capacity at any given point in time. According to the theory of instantaneous power, the reactive and active power of inverter can be regulated by changing the amplitude and the phase of the output voltage of the inverter. Based on this theory, the active power output and the reactive power compensation (RPC) of the system are realized simultaneously. When the insolation is weak or the PV modules are inoperative at night, the RPC feature of PV system can still be used to improve the utilization factor of the inverter. The MATLAB simulation results validate the feasibility of the method. (author)

  18. Experimental analysis and modeling of the IV characteristics of photovoltaic solar cells under solar spectrum spot illumination

    Energy Technology Data Exchange (ETDEWEB)

    Munji, M.K., E-mail: mathew.munji@nmmu.ac.z [Department of Physics, Nelson Mandela Metropolitan University, PO Box 7700 Port Elizabeth 6031 (South Africa); Dyk, E.E. van; Vorster, F.J. [Department of Physics, Nelson Mandela Metropolitan University, PO Box 7700 Port Elizabeth 6031 (South Africa)

    2009-12-01

    In this paper, some models that have been put forward to explain the characteristics of a photovoltaic solar cell device under solar spot-illumination are investigated. In the experimental procedure, small areas of the cell were selected and illuminated at different solar intensities. The solar cell open circuit voltage (V{sub oc}) and short circuit current (I{sub sc}) obtained at different illumination intensities was used to determine the solar cell ideality factor. By varying the illuminated area on the solar cell, changes in the ideality factor were studied. The ideality factor obtained increases with decreasing illumination surface ratio. The photo-generated current at the illuminated part of the cell is assumed to act as a dc source that injects charge carriers into the p-n junction of the whole solar cell while the dark region of the solar cell operates in a low space charge recombination regime with small diffusion currents. From this analysis, a different model of a spot illuminated cell that uses the variation of ideality factor with the illuminated area is proposed.

  19. Experimental analysis and modeling of the IV characteristics of photovoltaic solar cells under solar spectrum spot illumination

    International Nuclear Information System (INIS)

    Munji, M.K.; Dyk, E.E. van; Vorster, F.J.

    2009-01-01

    In this paper, some models that have been put forward to explain the characteristics of a photovoltaic solar cell device under solar spot-illumination are investigated. In the experimental procedure, small areas of the cell were selected and illuminated at different solar intensities. The solar cell open circuit voltage (V oc ) and short circuit current (I sc ) obtained at different illumination intensities was used to determine the solar cell ideality factor. By varying the illuminated area on the solar cell, changes in the ideality factor were studied. The ideality factor obtained increases with decreasing illumination surface ratio. The photo-generated current at the illuminated part of the cell is assumed to act as a dc source that injects charge carriers into the p-n junction of the whole solar cell while the dark region of the solar cell operates in a low space charge recombination regime with small diffusion currents. From this analysis, a different model of a spot illuminated cell that uses the variation of ideality factor with the illuminated area is proposed.

  20. Socio- economic impact study of the electrification by the photovoltaic solar system in the AIJ/RPTES project area

    International Nuclear Information System (INIS)

    2000-04-01

    This report is a summary of the results of the study relating to the socio-economical impact of the electrification by photovoltaic solar system in the zones of the project AIJ/RPTES. The localities concerned with the study are the provinces of BALE and the MOUHOUN. The data analyzes relating to the electrification by solar system of the zones of the project AIJ/RPTES, revealed that solar electrical energy contributed to a significant degree to the socio-economic development, especially at the level of the structures having profited from the solar equipment. The principal conclusions drawn from these analyzes attested that: the solar system corresponds as well as possible for rural environment as well on the technological level as on the capacity plan of maintenance. The following reasons come to corroborate this fact: the weakness of the costs of management of the photovoltaic modules; the photovoltaic technic, in spite of a low incidental maximum power (1 kw/ m 2 ), satisfied the priority needs for the rural populations (lighting, access to information and education, conservation of the vaccines in the CSPS, etc). - be photovoltaic installations cause: an average financial profit by CSPS of 180 487.5 FCFA/an, and a financial economy in the parents of the new-born babies estimated at 36,600 FCFA/an in each CSPS; an average financial economy by household of 49,452 FCFA/an [fr

  1. Renewable Energy Systems: Development and Perspectives of a Hybrid Solar-Wind System

    OpenAIRE

    C. Shashidhar; K. Bhanupriya; P. Alluvada; Bandana; J. B. V. Subrahmanyam

    2012-01-01

    Considering the intermittent natural energy resources and the seasonal un-balance, a phtovoltaic-wind hybrid electrical power supply system was developed to accommodate remote locations where a conventional grid connection is inconvenient or expensive. However, the hybrid system can also be applied with grid connection and owners are allowed to sell excessive power back to the electric utility. The proposed set-up consists of a photo-voltaic solar-cell array, a mast mounted wind generator, le...

  2. Thermal behavior of novel hybrid inorganic-organic phosphazene polymers

    NARCIS (Netherlands)

    Bosscher, G; Wieringa, RH; Jekel, AP; vandeGrampel, JC

    The thermal behavior of the following systems have been investigated by TGA and XPS: the homopolymer of N3P3Cl4(CH3)(CH2C6H4CH=CH2) (1), copolymers of 1 with MMA and styrene, and copolymers of N3P3Cl4(i-C3H7) {C[OC(O)CH3]=CH2} (2) with MMA and styrene. Upon heating under TGA conditions the highest

  3. Thermal performances of vertical hybrid PV/T air collector

    Science.gov (United States)

    Tabet, I.; Touafek, K.; Bellel, N.; Khelifa, A.

    2016-11-01

    In this work, numerical analyses and the experimental validation of the thermal behavior of a vertical photovoltaic thermal air collector are investigated. The thermal model is developed using the energy balance equations of the PV/T air collector. Experimental tests are conducted to validate our mathematical model. The tests are performed in the southern Algerian region (Ghardaïa) under clear sky conditions. The prototype of the PV/T air collector is vertically erected and south oriented. The absorber upper plate temperature, glass cover temperature, air temperature in the inlet and outlet of the collector, ambient temperature, wind speed, and solar radiation are measured. The efficiency of the collector increases with increase in mass flow of air, but the increase in mass flow of air reduces the temperature of the system. The increase in efficiency of the PV/T air collector is due to the increase in the number of fins added. In the experiments, the air temperature difference between the inlet and the outlet of the PV/T air collector reaches 10 ° C on November 21, 2014, the interval time is between 10:00 and 14:00, and the temperature of the upper plate reaches 45 ° C at noon. The mathematical model describing the dynamic behavior of the typical PV/T air collector is evaluated by calculating the root mean square error and mean absolute percentage error. A good agreement between the experiment and the simulation results is obtained.

  4. Modelling and Investigation of a Hybrid Thermal Energy Harvester

    Directory of Open Access Journals (Sweden)

    Todorov Todor

    2018-01-01

    Full Text Available The presented paper deals with dynamical and experimental investigations of a hybrid energy harvester containing shape memory alloy (SMA wire and elastic cantilever with piezoelectric layer. The SMA wire periodically changes its temperature under the influence of a heated plate that approaches and moves away from the SMA wire. The change of SMA wire length causes rotation of the hot plate. The plate is heated by a heater with constant temperature. The repeated SMA wire extensions and contractions bend the piezoelectric cantilever which generates electric charges. The shape memory effect is presented as a temperature approximation of the Young’s modulus. A dynamical model of the energy harvester is created and some analytical investigations are presented. With the help of an experimental setup the acceleration, the force, the temperature, and the output voltage have been measured. The theoretical results are validated experimentally. Some conclusions are made about the best performance of the energy harvester.

  5. The performance and applicability study of a fixed photovoltaic-solar water disinfection system

    International Nuclear Information System (INIS)

    Jin, Yanchao; Wang, Yiping; Huang, Qunwu; Zhu, Li; Cui, Yong; Cui, Lingyun

    2016-01-01

    Highlights: • A fixed photovoltaic-SODIS (solar water disinfection) system was constructed. • The system could generate electricity and produce clean water simultaneously. • The daily solar generated electricity was much more than the system consumption. • The system can be used for about 90% of whole year in Lhasa and Chennai. • Temperature enhanced the SODIS process for about 60% days of whole year in Chennai. - Abstract: The objective of the study is to construct and evaluate a fixed PV (photovoltaic) cell integrated with SODIS (solar water disinfection) system to treat drinking water and generate electricity under different climate through experimental and simulation methods. The photovoltaic and disinfection performances of the hybrid system were studied by the disinfection of Escherichia coli. The applicability of the system in Lhasa and Chennai was evaluated by analyzing the daily radiation and predicting the daily water temperature and the system electricity output. The results confirm that the temperature would dramatically enhance the SODIS process and shorten the disinfection time, when the water temperature was above 45 °C. The PV cell in the hybrid system could work under low temperature because of the water layer and the generated electricity was much more than the system consumption. The simulation results show that the days with maximum water temperature above 45 °C were more than 60% of whole year in Chennai. The generated electricity of the hybrid system was 49682.3 W h and 45615.9 W h a year in Lhasa and Chennai respectively. It was sufficient to drive the system of whole year. The number of days which realized drinking water treatment was 324 days in Lhasa and 315 days in Chennai a year.

  6. An experimental study on energy generation with a photovoltaic (PV)-solar thermal hybrid system

    International Nuclear Information System (INIS)

    Erdil, Erzat; Ilkan, Mustafa; Egelioglu, Fuat

    2008-01-01

    A hybrid system, composed of a photovoltaic (PV) module and a solar thermal collector is constructed and tested for energy collection at a geographic location of Cyprus. Normally, it is required to install a PV system occupying an area of about 10 m 2 in order to produce electrical energy; 7 kWh/day, required by a typical household. In this experimental study, we used only two PV modules of area approximately 0.6 m 2 (i.e., 1.3x0.47 m 2 ) each. PV modules absorb a considerable amount of solar radiation that generate undesirable heat. This thermal energy, however, may be utilized in water pre-heating applications. The proposed hybrid system produces about 2.8 kWh thermal energy daily. Various attachments that are placed over the hybrid modules lead to a total of 11.5% loss in electrical energy generation. This loss, however, represents only 1% of the 7 kWh energy that is consumed by a typical household in northern Cyprus. The pay-back period for the modification is less than 2 years. The low investment cost and the relatively short pay-back period make this hybrid system economically attractive

  7. A review on photovoltaic/thermal hybrid solar technology

    International Nuclear Information System (INIS)

    Chow, T.T.

    2010-01-01

    A significant amount of research and development work on the photovoltaic/thermal (PVT) technology has been done since the 1970s. Many innovative systems and products have been put forward and their quality evaluated by academics and professionals. A range of theoretical models has been introduced and their appropriateness validated by experimental data. Important design parameters are identified. Collaborations have been underway amongst institutions or countries, helping to sort out the suitable products and systems with the best marketing potential. This article gives a review of the trend of development of the technology, in particular the advancements in recent years and the future work required. (author)

  8. Photo-thermal characteristics of hybrid nanofluids based on Therminol-55 oil for concentrating solar collectors

    Science.gov (United States)

    Gulzar, Ovais; Qayoum, Adnan; Gupta, Rajat

    2018-03-01

    Hybrid nanofluids are the new generation efficient heat transfer fluids allowing greater control over the properties of base fluid as compared to mono-nanofluids. In this study, attempt has been made for increasing the efficiency for photo-thermal conversion by heat transfer fluid for high temperature solar collectors. Therminol-55, a high temperature heat transfer fluid is doped with Al2O3 and TiO2 nanoparticles with an aim to improve the thermal and optical properties. Effects of concentration and type of nanoparticle on photo-thermal conversion properties and absorbance in Therminol-55 have been studied. Spectrophotometric analysis has been carried for all nanofluids, namely, Al2O3-Therminol-55, TiO2-Therminol-55 and hybrid (Al2O3-TiO2)-Therminol-55 nanofluids with varying concentrations of 0.05, 0.075, 0.1, 0.25, 0.5 wt%. It was found that TiO2 nanofluids possess the maximum absorbance with minimal effect of nanoparticle concentration above 0.1 wt% followed by hybrid (Al2O3-TiO2) nanofluid (HNF) with strong dependence of concentration. Al2O3-Therminol-55 nanofluids exhibited least absorbance. The peak values of absorbance are 0.47, 2.15 and 2.144 in the visible region for Al2O3-Therminol-55, TiO2-Therminol-55 and hybrid (Al2O3-TiO2)-Therminol-55 nanofluids, respectively. It was observed that hybrid nanofluids show both bathochromic and hyperchromic shifts. Further, performance testing has been carried out using artificial source of light and it has been observed that hybrid nanofluids provide efficient photo-thermal conversion as compared to TiO2 and Al2O3-Therminol-55 nanofluids. Maximum temperatures of 152.9, 149.6, 158.6 °C were observed for 0.5 wt% Al2O3-Therminol-55, 0.1 wt% TiO2-Therminol-55, and 0.5 wt% hybrid (Al2O3-TiO2) nanofluid, respectively, against 125.8 °C of Therminol-55. Hybrid nanofluids based on Therminol-55 could be a potential candidate for high temperature concentrating collectors based on the superior properties over mono-nanofluids and

  9. Optical and mechanical tolerances in hybrid concentrated thermal-PV solar trough.

    Science.gov (United States)

    Diaz, Liliana Ruiz; Cocilovo, Byron; Miles, Alexander; Pan, Wei; Blanche, Pierre-Alexandre; Norwood, Robert A

    2018-05-14

    Hybrid thermal-PV solar trough collectors combine concentrated photovoltaics and concentrated solar power technology to harvest and store solar energy. In this work, the optical and mechanical requirements for optimal efficiency are analyzed using non-sequential ray tracing techniques. The results are used to generate opto-mechanical tolerances that can be compared to those of traditional solar collectors. We also explore ideas on how to relieve tracking tolerances for single-axis solar collectors. The objective is to establish a basis for tolerances required for the fabrication and manufacturing of hybrid solar trough collectors.

  10. The electrical and thermal transport properties of hybrid zigzag graphene-BN nanoribbons

    Science.gov (United States)

    Gao, Song; Lu, Wei; Zheng, Guo-Hui; Jia, Yalei; Ke, San-Huang

    2017-06-01

    The electron and phonon transport in hybrid graphene-BN zigzag nanoribbons are investigated by the nonequilibrium Green’s function method combined with density functional theory calculations. A 100% spin-polarized electron transport in a large energy window around the Fermi level is found and this behavior is independent of the ribbon width as long as there contain 3 zigzag carbon chains. The phonon transport calculations show that the ratio of C-chain number to BN-chain number will modify the thermal conductance of the hybrid nanoribbon in a complicated manner.

  11. The electrical and thermal transport properties of hybrid zigzag graphene-BN nanoribbons

    International Nuclear Information System (INIS)

    Gao, Song; Lu, Wei; Zheng, Guo-Hui; Jia, Yalei; Ke, San-Huang

    2017-01-01

    The electron and phonon transport in hybrid graphene-BN zigzag nanoribbons are investigated by the nonequilibrium Green’s function method combined with density functional theory calculations. A 100% spin-polarized electron transport in a large energy window around the Fermi level is found and this behavior is independent of the ribbon width as long as there contain 3 zigzag carbon chains. The phonon transport calculations show that the ratio of C-chain number to BN-chain number will modify the thermal conductance of the hybrid nanoribbon in a complicated manner. (paper)

  12. Thermal analysis of hybrid single-phase, two-phase and heat pump thermal control system (TCS) for future spacecraft

    International Nuclear Information System (INIS)

    Lee, S.H.; Mudawar, I.; Hasan, Mohammad M.

    2016-01-01

    Highlights: • Hybrid Thermal Control System (H-TCS) is proposed for future spacecraft. • Thermodynamic performance of H-TCS is examined for different space missions. • Operational modes including single-phase, two-phase and heat pump are explored. • R134a is deemed most appropriate working fluid. - Abstract: An urgent need presently exists to develop a new class of versatile spacecraft capable of conducting different types of missions and enduring varying gravitational and temperature environments, including Lunar, Martian and Near Earth Object (NEOs). This study concerns the spacecraft's Thermal Control System (TCS), which tackles heat acquisition, especially from crew and avionics, heat transport, and ultimate heat rejection by radiation. The primary goal of the study is to explore the design and thermal performance of a Hybrid Thermal Control System (H-TCS) that would satisfy the diverse thermal requirements of the different space missions. The H-TCS must endure both ‘cold’ and ‘hot’ environments, reduce weight and size, and enhance thermodynamic performance. Four different operational modes are considered: single-phase, two-phase, basic heat pump and heat pump with liquid-side, suction-side heat exchanger. A thermodynamic trade study is conducted for six different working fluids to assess important performance parameters including mass flow rate of the working fluid, maximum pressure, radiator area, compressor/pump work, and coefficient of performance (COP). R134a is determined to be most suitable based on its ability to provide a balanced compromise between reducing flow rate and maintaining low system pressure, and a moderate coefficient of performance (COP); this fluid is also both nontoxic and nonflammable, and features zero ozone depletion potential (ODP) and low global warming potential (GWP). It is shown how specific mission stages dictate which mode of operation is most suitable, and this information is used to size the radiator for the

  13. Covalently Bonded Graphene-Carbon Nanotube Hybrid for High-Performance Thermal Interfaces

    DEFF Research Database (Denmark)

    Chen, Jie; Walther, Jens H.; Koumoutsakos, Petros

    2015-01-01

    The remarkable thermal properties of graphene and carbon nanotubes (CNTs) have been the subject of intensive investigations for the thermal management of integrated circuits. However, the small contact area of CNTs and the large anisotropic heat conduction of graphene have hindered...... their applications as effective thermal interface materials (TIMs). Here, a covalently bonded graphene–CNT (G-CNT) hybrid is presented that multiplies the axial heat transfer capability of individual CNTs through their parallel arrangement, while at the same time it provides a large contact area for efficient heat...... extraction. Through computer simulations, it is demonstrated that the G-CNT outperforms few-layer graphene by more than 2 orders of magnitude for the c-axis heat transfer, while its thermal resistance is 3 orders of magnitude lower than the state-of-the-art TIMs. We show that heat can be removed from the G...

  14. Hybrid transport and diffusion modeling using electron thermal transport Monte Carlo SNB in DRACO

    Science.gov (United States)

    Chenhall, Jeffrey; Moses, Gregory

    2017-10-01

    The iSNB (implicit Schurtz Nicolai Busquet) multigroup diffusion electron thermal transport method is adapted into an Electron Thermal Transport Monte Carlo (ETTMC) transport method to better model angular and long mean free path non-local effects. Previously, the ETTMC model had been implemented in the 2D DRACO multiphysics code and found to produce consistent results with the iSNB method. Current work is focused on a hybridization of the computationally slower but higher fidelity ETTMC transport method with the computationally faster iSNB diffusion method in order to maximize computational efficiency. Furthermore, effects on the energy distribution of the heat flux divergence are studied. Work to date on the hybrid method will be presented. This work was supported by Sandia National Laboratories and the Univ. of Rochester Laboratory for Laser Energetics.

  15. 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).

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

    Science.gov (United States)

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

    2013-07-01

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

  17. Hybrid heating systems optimization of residential environment to have thermal comfort conditions by numerical simulation.

    Science.gov (United States)

    Jahantigh, Nabi; Keshavarz, Ali; Mirzaei, Masoud

    2015-01-01

    The aim of this study is to determine optimum hybrid heating systems parameters, such as temperature, surface area of a radiant heater and vent area to have thermal comfort conditions. DOE, Factorial design method is used to determine the optimum values for input parameters. A 3D model of a virtual standing thermal manikin with real dimensions is considered in this study. Continuity, momentum, energy, species equations for turbulent flow and physiological equation for thermal comfort are numerically solved to study heat, moisture and flow field. K - ɛRNG Model is used for turbulence modeling and DO method is used for radiation effects. Numerical results have a good agreement with the experimental data reported in the literature. The effect of various combinations of inlet parameters on thermal comfort is considered. According to Pareto graph, some of these combinations that have significant effect on the thermal comfort require no more energy can be used as useful tools. A better symmetrical velocity distribution around the manikin is also presented in the hybrid system.

  18. Design, fabrication and performance of a hybrid photovoltaic/thermal (PV/T) active solar still

    International Nuclear Information System (INIS)

    Kumar, Shiv; Tiwari, Arvind

    2010-01-01

    Two solar stills (single slope passive and single slope photovoltaic/thermal (PV/T) active solar still) were fabricated and tested at solar energy park, IIT New Delhi (India) for composite climate. Photovoltaic operated DC water pump was used between solar still and photovoltaic (PV) integrated flat plate collector to re-circulate the water through the collectors and transfer it to the solar still. The newly designed hybrid (PV/T) active solar still is self-sustainable and can be used in remote areas, need to transport distilled water from a distance and not connected to grid, but blessed with ample solar energy. Experiments were performed for 0.05, 0.10, and 0.15 m water depth, round the year 2006-2007 for both the stills. It has been observed that maximum daily yield of 2.26 kg and 7.22 kg were obtained from passive and hybrid active solar still, respectively at 0.05 m water depth. The daily yield from hybrid active solar still is around 3.2 and 5.5 times higher than the passive solar still in summer and winter month, respectively. The study has shown that this design of the hybrid active solar still also provides higher electrical and overall thermal efficiency, which is about 20% higher than the passive solar still.

  19. The role of hybrid nanofluids in improving the thermal characteristics of screen mesh cylindrical heat pipes

    Directory of Open Access Journals (Sweden)

    Ramachandran Raghavan Nair

    2016-01-01

    Full Text Available Experiments were conducted to study the thermal performance of meshed wick heat pipe by varying the working fluid and heat input. In this work four screen mesh wicked heat pipes were fabricated and tested. All the heat pipes were tested for heat input from 50W to 250W each with an increment of 50W in each step. The heat input range selected in this study is commonly encountered in most of the electronic application devices. The thermal resistance of all the heat pipes charged with different working fluids such as DI water, Al2O3/DI water nanofluid of volume concentration 0.1 % and hybrid nanofluid volume concentration 0.1%( with two different combinations of (Al2O3 50%- CuO 50%/DI water and (Al2O3 25%- CuO 75%/DI waterwas determined. The maximum percentage reduction was found to be 58.87% for the hybrid nanofluid of (Al2O3 25%- CuO 75%/DI water compared to base fluid. An important observation from the study is that, use of hybrid nanofluid can raise the operating range of the heat pipe beyond 250W which makes hybrid nanofluid as a potential substitute for the conventional working fluid.

  20. Hybrid indirect/direct contactor for thermal management of counter-current processes

    Science.gov (United States)

    Hornbostel, Marc D.; Krishnan, Gopala N.; Sanjurjo, Angel

    2018-03-20

    The invention relates to contactors suitable for use, for example, in manufacturing and chemical refinement processes. In an aspect is a hybrid indirect/direct contactor for thermal management of counter-current processes, the contactor comprising a vertical reactor column, an array of interconnected heat transfer tubes within the reactor column, and a plurality of stream path diverters, wherein the tubes and diverters are configured to block all straight-line paths from the top to bottom ends of the reactor column.

  1. Thermal Analysis and Microhardness Mapping in Hybrid Laser Welds in a Structural Steel

    Science.gov (United States)

    2003-01-01

    conditions. Via the keyhole the laser beam brings about easier ignition of the arc, stabilization of the arc welding process, and penetration of the...with respect to the conventional GMAW or GTAW processes without the need for very close fit-up. This paper will compare an autogenous laser weld to a...UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADP017864 TITLE: Thermal Analysis and Microhardness Mapping in Hybrid Laser

  2. Can Integrated Micro-Optical Concentrator Technology Revolutionize Flat-Plate Photovoltaic Solar Energy Harvesting?

    Science.gov (United States)

    Haney, Michael W.

    2015-12-01

    The economies-of-scale and enhanced performance of integrated micro-technologies have repeatedly delivered disruptive market impact. Examples range from microelectronics to displays to lighting. However, integrated micro-scale technologies have yet to be applied in a transformational way to solar photovoltaic panels. The recently announced Micro-scale Optimized Solar-cell Arrays with Integrated Concentration (MOSAIC) program aims to create a new paradigm in solar photovoltaic panel technology based on the incorporation of micro-concentrating photo-voltaic (μ-CPV) cells. As depicted in Figure 1, MOSAIC will integrate arrays of micro-optical concentrating elements and micro-scale PV elements to achieve the same aggregated collection area and high conversion efficiency of a conventional (i.e., macro-scale) CPV approach, but with the low profile and mass, and hopefully cost, of a conventional non-concentrated PV panel. The reduced size and weight, and enhanced wiring complexity, of the MOSAIC approach provide the opportunity to access the high-performance/low-cost region between the conventional CPV and flat-plate (1-sun) PV domains shown in Figure 2. Accessing this portion of the graph in Figure 2 will expand the geographic and market reach of flat-plate PV. This talk reviews the motivation and goals for the MOSAIC program. The diversity of the technical approaches to micro-concentration, embedded solar tracking, and hybrid direct/diffuse solar resource collection found in the MOSAIC portfolio of projects will also be highlighted.

  3. Optimal control of a fuel cell/wind/PV/grid hybrid system with thermal heat pump load

    CSIR Research Space (South Africa)

    Sichilalu, S

    2016-10-01

    Full Text Available This paper presents an optimal energy management strategy for a grid-tied photovoltaic–wind-fuel cell hybrid power supply system. The hybrid system meets the load demand consisting of an electrical load and a heat pump water heater supplying thermal...

  4. Hybrid van der Waals SnO/MoS2 Heterojunctions for Thermal and Optical Sensing Applications

    KAUST Repository

    Wang, Zhenwei; He, Xin; Zhang, Xixiang; Alshareef, Husam N.

    2017-01-01

    /oxide hybrid vdWH based on n-type molybdenum disulfide (MoS2) and p-type tin monoxide (SnO) is presented, with promising rectification, thermal-sensing, and photosensing performance. Specifically, the hybrid SnO/MoS2 vdWH shows static rectification ratio of 2

  5. Energy integration on multi-periods and multi-usages for hybrid electric and thermal powertrains

    International Nuclear Information System (INIS)

    Dimitrova, Zlatina; Maréchal, François

    2015-01-01

    The improvement of the efficiency of vehicle energy systems promotes an active search to find innovative solutions during the design process. This requires more accurate modeling of complex systems, which offers new ways to improve the design efficiency of energy systems. The vehicle is a highly dynamic system. The size and the efficiency of the convertors are dependent on the dynamic driving profile. In order to increase the energy efficiency, using energy integration techniques, an adapted methodology is required to choose the best points for the integrated system design. The idea is to clusterize the dynamic profile on typical multi-periods of the vehicle use. The energy system design is then optimized for these typical multi-periods. In this article a new methodology is applied on hybrid electric vehicles, in order to define the energy integrated powertrain configuration of the vehicle. The energy recovery potential of a single stage Organic Rankine Cycle for a thermal engine in combination with a hybrid electric powertrain is assessed for different drive cycles profiles and comfort situations. After the energy integration, a multi-objective optimization is applied to define the optimal design of a hybrid electric vehicle with a waste heat recovery system. - Highlights: • K-means algorithm transforms the dynamic driving profile on static multi-periods. • The clusters represent the typical powertrain use and size the heat recovery utility. • The maximal heat recovery potential on thermal powertrains is 11% for urban driving. • The maximal heat recovery potential on hybrid electric powertrains is 5%. • Engine downsizing increases heat recovery potential on hybrid electric powertrains

  6. A new concept of hybrid photovoltaic thermal (PVT) collector with natural circulation

    Science.gov (United States)

    Lu, Longsheng; Wang, Xiaowu; Wang, Shuai; Liu, Xiaokang

    2017-07-01

    Hybrid photovoltaic thermal (PVT) technology refers to the integration of a photovoltaic module into a conventional solar thermal collector. Generally, the traditional design of a PVT collector has solar cells fixed on the top surface of an absorber in a flat-plate solar thermal collector. In this work, we presented a new concept of water-based PVT collector in which solar cells were directly placed on the bottom surface of its glass cover. A dynamic numerical model of this new PVT is developed and validated by experimental tests. With numerical analysis, it is found that at same covering factor, the electricity conversion efficiency of solar cells of the new PVT exceed that of the traditional PVT by nearly 10% while its thermal efficiency is approximately 30% lower than that of the traditional PVT. When the covering factor changes from 0.05 to 1, the thermal efficiency of the new PVT drops nearly 70%. The thermal efficiency of both the new PVT and the traditional PVT rise up as the water mass in tank increases. Meanwhile, the final water temperature in tank of the traditional PVT collector declines more than 17 °C, whereas that of the new PVT declines less than 6 °C, when the water mass increases from 100 to 300 kg.

  7. Experimental and numerical studies of hybrid PCM embedded in plastering mortar for enhanced thermal behaviour of buildings

    International Nuclear Information System (INIS)

    Kheradmand, Mohammad; Azenha, Miguel; Aguiar, José L.B. de; Castro-Gomes, João

    2016-01-01

    This paper proposes a methodology for improvement of energy efficiency in buildings through the innovative simultaneous incorporation of three distinct phase change materials (here termed as hybrid PCM) in plastering mortars for façade walls. The thermal performance of a hybrid PCM mortar was experimentally evaluated by comparing the behaviour of a prototype test cell (including hybrid PCM plastering mortar) subjected to realistic daily temperature profiles, with the behaviour of a similar prototype test cell, in which no PCM was added. A numerical simulation model was employed (using ANSYS-FLUENT) to validate the capacity of simulating temperature evolution within the prototype containing hybrid PCM, as well as to understand the contribution of hybrid PCM to energy efficiency. Incorporation of hybrid PCM into plastering mortars was found to have the potential to significantly reduce heating/cooling temperature demands for maintaining the interior temperature within comfort levels when compared to normal mortars (without PCM), or even mortars comprising a single type of PCM. - Highlights: • New concept of incorporation of more than 1 type of PCM in plastering mortars (hybrid PCM). • Assessment of thermal performance of hybrid PCM plastering mortar. • Thermo-physical properties of plastering mortars modified with PCMs incorporation. • Experimental and numerical simulations of thermal behaviour on laboratory scale prototype.

  8. Thermal, mechanical, and physical properties of seaweed/sugar palm fibre reinforced thermoplastic sugar palm Starch/Agar hybrid composites.

    Science.gov (United States)

    Jumaidin, Ridhwan; Sapuan, Salit M; Jawaid, Mohammad; Ishak, Mohamad R; Sahari, Japar

    2017-04-01

    The aim of this research is to investigate the effect of sugar palm fibre (SPF) on the mechanical, thermal and physical properties of seaweed/thermoplastic sugar palm starch agar (TPSA) composites. Hybridized seaweed/SPF filler at weight ratio of 25:75, 50:50 and 75:25 were prepared using TPSA as a matrix. Mechanical, thermal and physical properties of hybrid composites were carried out. Obtained results indicated that hybrid composites display improved tensile and flexural properties accompanied with lower impact resistance. The highest tensile (17.74MPa) and flexural strength (31.24MPa) was obtained from hybrid composite with 50:50 ratio of seaweed/SPF. Good fibre-matrix bonding was evident in the scanning electron microscopy (SEM) micrograph of the hybrid composites' tensile fracture. Fourier transform infrared spectroscopy (FT-IR) analysis showed increase in intermolecular hydrogen bonding following the addition of SPF. Thermal stability of hybrid composites was enhanced, indicated by a higher onset degradation temperature (259°C) for 25:75 seaweed/SPF composites than the individual seaweed composites (253°C). Water absorption, thickness swelling, water solubility, and soil burial tests showed higher water and biodegradation resistance of the hybrid composites. Overall, the hybridization of SPF with seaweed/TPSA composites enhances the properties of the biocomposites for short-life application; that is, disposable tray, plate, etc. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. A novel thermal and pH responsive drug delivery system based on ZnO@PNIPAM hybrid nanoparticles

    International Nuclear Information System (INIS)

    Tan, Licheng; Liu, Jian; Zhou, Weihua; Wei, Junchao; Peng, Zhiping

    2014-01-01

    A smart ZnO@PNIPAM hybrid was prepared by grafting thermal responsive poly(N-isopropylacrylamide) (PNIPAM) on zinc oxide (ZnO) nanoparticles via surface-initiated atom transfer radical polymerization (ATRP). The thermal gravimetric analysis (TGA) shows that the grafting amount of PNIPAM was about 38%, and the SEM images show that the PNIPAM chains can prevent the aggregation of ZnO nanoparticles. The responsive properties of ZnO@PNIPAM were measured by photoluminescence spectra, and the results demonstrate that the PNIPAM chains grafted on ZnO surfaces can realize reversible thermal responsive and photoluminescence properties. An anticancer drug, doxorubicin (Dox), was used as a model drug and loaded into the hybrid nanoparticles, and an in vitro drug release test implied that ZnO@PNIPAM could work as a thermal responsive drug delivery system. Furthermore, pH sensitive drug releases were carried out in acetate buffer at pH 5.0 and pH 6.0 and in water at pH 7.0, and the results showed evident pH dependency, showing its pH responsive properties. - Graphical abstract: In this manuscript, thermal responsive poly(N-isopropylacrylamide) (PNIPAM) was grafted on the surface of ZnO nanoparticles. The obtained ZnO@PNIPAM hybrid showed reversible thermal responsive photoluminescent properties, and can also work as a thermal and pH responsive drug delivery system. - Highlights: • The ZnO@PNIPAM hybrid was prepared via ATRP. • The ZnO@PNIPAM hybrid showed thermal responsive properties. • The ZnO@PNIPAM hybrid can work as a thermal and pH responsive drug delivery system

  10. Two orders of magnitude reduction in silicon membrane thermal conductivity by resonance hybridizations

    Science.gov (United States)

    Honarvar, Hossein; Hussein, Mahmoud I.

    2018-05-01

    The thermal conductivity of a freestanding single-crystal silicon membrane may be reduced significantly by attaching nanoscale pillars on one or both surfaces. Atomic resonances of the nanopillars form vibrons that intrinsically couple with the base membrane phonons causing mode hybridization and flattening at each coupling location in the phonon band structure. This in turn causes group velocity reductions of existing phonons, in addition to introducing new modes that get excited but are localized and do not transport energy. The nanopillars also reduce the phonon lifetimes at and around the hybridization zones. These three effects, which in principle may be tuned to take place across silicon's full spectrum, lead to a lowering of the in-plane thermal conductivity in the base membrane. Using equilibrium molecular dynamics simulations, and utilizing the concept of vibrons compensation, we report a staggering two orders of magnitude reduction in the thermal conductivity at room temperature by this mechanism. Specifically, a reduction of a factor of 130 is demonstrated for a roughly 10-nm-thick pillared membrane compared to a corresponding unpillared membrane. This amounts to a record reduction of a factor of 481 compared to bulk crystalline silicon and nearly a factor of 2 compared to bulk amorphous silicon. These results are obtained while providing a path for preserving performance with upscaling.

  11. Thermal analysis of a hybrid solar energy saving system inside a greenhouse

    International Nuclear Information System (INIS)

    Ntinas, G.K.; Fragos, V.P.; Nikita-Martzopoulou, Ch.

    2014-01-01

    Highlights: • A hybrid solar system consisted of water filled polyethylene sleeves was examined. • The thermal behaviour of the system was studied based on the sleeves energy balance. • Water temperature and heat exchanges of the sleeves were dynamically estimated. • Experimental data used to validate the predictions of the mathematical model. • The use of the system led to an energy saving of 23% inside a heated greenhouse. - Abstract: The intensive greenhouse energy requirements are a major operational and economical problem for producers around the world. Energy conservation techniques and innovative applications of solar energy for heating are being employed in greenhouse operation to reduce heating costs during cold periods. The present study investigated the development of a mathematical model to predict the thermal efficiency of a novel hybrid solar energy saving system inside a heated greenhouse. The solar system consisted of a transparent water-filled polyethylene sleeve and two perforated air-filled polyethylene tubes on the top peripheral sides of it. Above the sleeve and between the two tubes, rockwool substrates were placed for hydroponic cultivation of tomato crop. In order to validate this model, experiments were carried out in two identical parts of a polyethylene arched-type greenhouse to obtain data during winter. By comparing the measured and the predicted values, a correlation of 95% was found, indicating that the model can simulate the water temperature inside the hybrid solar sleeves. Moreover, the additional energy provided by the hybrid solar system reached approximately 23% during the examined period, depending on solar radiation levels

  12. The role of hybridization in improving the immune response and thermal tolerance of abalone.

    Science.gov (United States)

    Liang, Shuang; Luo, Xuan; You, Weiwei; Luo, Lianzhong; Ke, Caihuan

    2014-07-01

    Recently, frequent death of cultured abalone drew our attention to the stress tolerance of abalone. Hybridization is an effective way of genetic improvement in aquaculture, which can introduce improved traits to the hybrids. In this study, we challenged the hybrids between Haliotis discus hannai and Haliotis gigantea, and their parents with bacteria (vibrio harveyi, vibrio alginolyticus and vibrio parahemolyticus), then held them at 20 °C and 28 °C, survival rates of the parental populations and hybrid populations were recorded. Then we tested the immune responses and thermal-induced responses of the four populations at different temperatures. Total hemocyte count (THC), respiratory burst, superoxide dismutase activity (SOD), acid phosphatase activity (ACP), alkaline phosphatase activity (AKP), myeloperoxidase activity (MPO), and HSP70 expression were determined on day 1 and day 7 of the temperature exposure. Results showed higher survival rates of the hybrids than their parents against bacteria challenge. For immune parameters, THCs were evaluated at 28 °C, while increased THC was also observed in H. discus hannai ♀ × H. gigantea ♂ (DG) and H. discus hannai ♀ × H. discus hannai ♂ (DD) at 12 °C (day 7); at 28 °C, respiratory burst was activated (day 1 and 7), while SOD activity first rose then fell over 7-days exposure; AKP activity was elevated at 12 °C and 28 °C (day 1), most notably in DG, and an increased level of ACP was observed in DG at 28 °C (day 7); MPO activity was suppressed at 12 °C and 28 °C on day 1, but recovered on day 7. For HSP70, increased HSP70 levels were observed in all populations at 28 °C (day 1), and DD got the lowest HSP70 level after 7-days exposure at 28 °C. Overall, the results suggest that temperature changes could significantly affect the physiological status of abalone, and hybrids may be more resistant to disease and thermal stresses than their parents. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Energy efficient hybrid nanocomposite-based cool thermal storage air conditioning system for sustainable buildings

    International Nuclear Information System (INIS)

    Parameshwaran, R.; Kalaiselvam, S.

    2013-01-01

    The quest towards energy conservative building design is increasingly popular in recent years, which has triggered greater interests in developing energy efficient systems for space cooling in buildings. In this work, energy efficient silver–titania HiTES (hybrid nanocomposites-based cool thermal energy storage) system combined with building A/C (air conditioning) system was experimentally investigated for summer and winter design conditions. HiNPCM (hybrid nanocomposite particles embedded PCM) used as the heat storage material has exhibited 7.3–58.4% of improved thermal conductivity than at its purest state. The complete freezing time for HiNPCM was reduced by 15% which was attributed to its improved thermophysical characteristics. Experimental results suggest that the effective energy redistribution capability of HiTES system has contributed for reduction in the chiller nominal cooling capacity by 46.3% and 39.6% respectively, under part load and on-peak load operating conditions. The HiTES A/C system achieved 27.3% and 32.5% of on-peak energy savings potential in summer and winter respectively compared to the conventional A/C system. For the same operating conditions, this system yield 8.3%, 12.2% and 7.2% and 10.2% of per day average and yearly energy conservation respectively. This system can be applied for year-round space conditioning application without sacrificing energy efficiency in buildings. - Highlights: • Energy storage is acquired by HiTES (hybrid nanocomposites-thermal storage) system. • Thermal conductivity of HiNPCM (hybrid nanocomposites-PCM) was improved by 58.4%. • Freezing time of HiNPCM was reduced by 15% that enabled improved energy efficiency. • Chiller nominal capacity was reduced by 46.3% and 39.6% in on-peak and part load respectively. • HiTES A/C system achieved appreciable energy savings in the range of 8.3–12.2%

  14. Research on hybrid transmission mode for HVDC with optimal thermal power and renewable energy combination

    Science.gov (United States)

    Zhang, Jinfang; Yan, Xiaoqing; Wang, Hongfu

    2018-02-01

    With the rapid development of renewable energy in Northwest China, curtailment phenomena is becoming more and more serve owing to lack of adjustment ability and enough transmission capacity. Based on the existing HVDC projects, exploring the hybrid transmission mode associated with thermal power and renewable power will be necessary and important. This paper has proposed a method on optimal thermal power and renewable energy combination for HVDC lines, based on multi-scheme comparison. Having established the mathematic model for electric power balance in time series mode, ten different schemes have been picked for figuring out the suitable one by test simulation. By the proposed related discriminated principle, including generation device utilization hours, renewable energy electricity proportion and curtailment level, the recommendation scheme has been found. The result has also validated the efficiency of the method.

  15. A Hybrid Power Control Concept for PV Inverters with Reduced Thermal Loading

    DEFF Research Database (Denmark)

    Yang, Yongheng; Wang, Huai; Blaabjerg, Frede

    2014-01-01

    on a single-phase PV inverter under yearly operation is presented with analyses of the thermal loading, lifetime, and annual energy yield. It has revealed the trade-off factors to select the power limit and also verified the feasibility and the effectiveness of the proposed control concept.......This letter proposes a hybrid power control concept for grid-connected Photovoltaic (PV) inverters. The control strategy is based on either a Maximum Power Point Tracking (MPPT) control or a Constant Power Generation (CPG) control depending on the instantaneous available power from the PV panels....... The essence of the proposed concept lies in the selection of an appropriate power limit for the CPG control to achieve an improved thermal performance and an increased utilization factor of PV inverters,and thus to cater for a higher penetration level of PV systems with intermittent nature. A case study...

  16. Thermal stability of octadecylsilane hybrid silicas prepared by grafting and sol-gel methods

    International Nuclear Information System (INIS)

    Brambilla, Rodrigo; Santos, Joao H.Z. dos; Miranda, Marcia S.L.; Frost, Ray L.

    2008-01-01

    Hybrid silicas bearing octadecylsilane groups were prepared by grafting and sol-gel (SG) methods. The effect of the preparative route on the thermal stability was evaluated by means of thermal gravimetric analysis (TGA), infrared emission spectroscopy (IRES) and, complementary, by 13 C solid-state nuclear magnetic resonance ( 13 C NMR) and matrix assisted laser deionization time of flight mass spectroscopy (MALDI-TOF-MS). Silicas prepared by the grafting route seem to be slightly more stable than those produced by the sol-gel method. This behavior seems to be associated to the preparative route, since grafting affords a liquid-like conformation, while in the case of sol-gel a highly organized crystalline chain conformation was observed

  17. Photovoltaic solar; Solaire photovoltaique

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-01-01

    This study aims to observe, from european examples, the local governments policies in matter of the photovoltaic development. This approach is very different for each town. The first part evaluates the initiatives, the second part is devoted to the global situation in Europe and the third part brings recommendations. (A.L.B.)

  18. Concentrating photovoltaic solar panel

    Science.gov (United States)

    Cashion, Steven A; Bowser, Michael R; Farrelly, Mark B; Hines, Braden E; Holmes, Howard C; Johnson, Jr., Richard L; Russell, Richard J; Turk, Michael F

    2014-04-15

    The present invention relates to photovoltaic power systems, photovoltaic concentrator modules, and related methods. In particular, the present invention features concentrator modules having interior points of attachment for an articulating mechanism and/or an articulating mechanism that has a unique arrangement of chassis members so as to isolate bending, etc. from being transferred among the chassis members. The present invention also features adjustable solar panel mounting features and/or mounting features with two or more degrees of freedom. The present invention also features a mechanical fastener for secondary optics in a concentrator module.

  19. Photovoltaic Solar Energy Generation

    CERN Document Server

    Lotsch, H.K.V; U.Hoffmann, Volker; Rhodes, William T; Asakura, Toshimitsu; Brenner, Karl-Heinz; Hänsch, Theodor W; Kamiya, Takeshi; Krausz, Ferenc; Monemar, Bo; Venghaus, Herbert; Weber, Horst; Weinfurter, Harald

    2005-01-01

    This comprehensive description and discussion of photovoltaics (PV) is presented at a level that makes it accessible to the interested academic. Starting with an historical overview, the text outlines the relevance of photovoltaics today and in the future. Then follows an introduction to the physical background of solar cells and the most important materials and technologies, with particular emphasis placed on future developments and prospects. The book goes beyond technology by also describing the path from the cell to the module to the system, proceeding to important applications, such as grid-connected and stand-alone systems. The composition and development of the markets and the role of PV in future energy systems are also considered. Finally, the discussion turns to the future structure of energy supplies, expected to comprise more distributed generation, and addresses synergies and competition from other carbon-free energy sources.

  20. Photovoltaic solar energy

    International Nuclear Information System (INIS)

    Mouratoglou, P.; Therond, P.G.

    2009-01-01

    The most important assets of photovoltaic energy for sustainable development are its simplicity (no need for complicated thermodynamical cycles) and the universal availability of the sun which explains its great popularity. The main restraint to its full development is the high cost of the technologies used. The silicon technology is the historical technology, it has high conversion rates but is expensive because of high fabrication costs. This technology represents 80% of the market. On the other hand the thin film technology with CdTe, CIS or CIGS is promising in terms of costs but requires research works to increase its conversion rate. Japan and Germany are the leader countries in terms of photovoltaic for research, industrial fabrication or state support, they are followed by Spain, Usa, and China. (A.C.)

  1. Development of a syngas-fired catalytic combustion system for hybrid solar-thermal applications

    International Nuclear Information System (INIS)

    Gupta, Mayank; Pramanik, Santanu; Ravikrishna, R.V.

    2016-01-01

    Highlights: • Syngas-fired combustor concept as hybrid heat source for solar thermal application. • Experimental characterization of catalytic combustor under fuel-rich conditions. • Stable operation, quick startup, and high turn-down ratio demonstrated. • Reacting flow CFD simulations of single channel of catalytic monolith. - Abstract: This paper describes the development and operation of a catalytic combustion system for use with syngas as an important component of a hybrid heating source for solar-thermal power generation. The reactor consists of a cylindrical ceramic monolith with porous alumina washcoat in which platinum is distributed as the catalyst. Two fuel-rich equivalence ratios were studied over a range of flow rates. The fuel-rich conditions permit low temperature combustion without the problem of hotspots likely to occur under fuel-lean conditions with hydrogen-containing fuels. Experimental data of temperature and species concentration at the exit of the reactor have been reported for a maximum fuel thermal input of 34 kW. The system exhibited quick start-up with a light-off time of around 60 s and a steady-state time of around 200 s as determined from the transient temperature profiles. The experimental results have also been complemented with detailed two-dimensional numerical simulations for improved understanding of the combustion characteristics in the reactor. The simulations suggest that the combustion system can be operated at a turn-down ratios far in excess of 1.67, which is the maximum value that has been investigated in the present setup. Stable operation, quick startup, and high turn-down ratio are some of the key features that enable the proposed combustion system to accommodate the transients in solar-thermal applications.

  2. Preparation of thermally stable microcapsules with a chitosan-silica hybrid.

    Science.gov (United States)

    Kang, Hong-Yi; Chen, Hui-Huang

    2014-09-01

    Addition of microcapsules with a high dielectric constant and low specific heat capacity to a battered layer was designed to create a higher temperature in the crust than in the prefried fish nuggets to prevent the water vapor in the fish nuggets from migrating to the crust during microwave heating. Therefore, chitosan-silica hybrids and soybean oil were utilized to prepare the shell and core of the thermally stable microcapsules (MC(CS)), respectively. The MC(CS) were prepared by sol-gel coacervation from an oil-in-water emulsion. The sodium silicate was hydrolyzed and coacervated through polymerization for 24 h at pH 5. The zeta potential analysis indicated that chitosan with a positive charge and silica with a negative charge interacted through electrostatic attraction to form a hybrid shell. The volume mean particle size and encapsulation efficiency of the MC(CS) were 9.6 ± 0.2 μm and 75.6% ± 1.3%, respectively, when oil/chitosan = 0.2 and chitosan/silica = 0.5 (w/w). In addition to H-bonding and electrostatic attraction, Si-O-N bonds were formed between chitosan and silica. Dehydration of the bound water in the MC(CS) was observed in the range of 25 to 250 °C in the differential scanning calorimetry thermal analysis, with the lack of apparent thermal peaks indicating its high thermal stability. The decrease of force to cut the crust observed by texture analysis as well as the increase of hedonic score by consumer acceptance test revealed the addition of 1% MC(CS) significantly improved the crispness of the crust in the microwave-reheated nuggets. © 2014 Institute of Food Technologists®

  3. Graphene-enhanced hybrid phase change materials for thermal management of Li-ion batteries

    Science.gov (United States)

    Goli, Pradyumna; Legedza, Stanislav; Dhar, Aditya; Salgado, Ruben; Renteria, Jacqueline; Balandin, Alexander A.

    2014-02-01

    Li-ion batteries are crucial components for progress in mobile communications and transport technologies. However, Li-ion batteries suffer from strong self-heating, which limits their life-time and creates reliability and environmental problems. Here we show that thermal management and the reliability of Li-ion batteries can be drastically improved using hybrid phase change material with graphene fillers. Conventional thermal management of batteries relies on the latent heat stored in the phase change material as its phase changes over a small temperature range, thereby reducing the temperature rise inside the battery. Incorporation of graphene to the hydrocarbon-based phase change material allows one to increase its thermal conductivity by more than two orders of magnitude while preserving its latent heat storage ability. A combination of the sensible and latent heat storage together with the improved heat conduction outside of the battery pack leads to a significant decrease in the temperature rise inside a typical Li-ion battery pack. The described combined heat storage-heat conduction approach can lead to a transformative change in thermal management of Li-ion and other types of batteries.

  4. Thermal-hydraulics design comparisons for the tandem mirror hybrid reactor blanket

    International Nuclear Information System (INIS)

    Wong, C.P.C.; Yang, Y.S.; Schultz, K.R.

    1980-09-01

    The Tandem Mirror Hybrid Reactor (TMHR) is a cylindrical reactor, and the fertile materials and tritium breeding fuel elements can be arranged with radial or axial orientation in the blanket module. Thermal-hydraulics performance comparisons were made between plate, axial rod and radial rod fuel geometrices. The three configurations result in different coolant/void fractions and different clad/structure fractions. The higher void fraction in the two rod designs means that these blankets will have to be thicker than the plate design blanket in order to achieve the same level of nuclear interactions. Their higher structural fractions will degrade the uranium breeding ratio and energy multiplication factor of the design. One difficulty in the thermal-hydraulics analysis of the plate design was caused by the varying energy multiplication of the blanket during the lifetime of the plate which forced the use of designs that operated in the transition flow regime at some point during life. To account for this, an approach was adopted from Gas Cooled Fast Reactor (GCFR) experience for the pressure drop calculation and the corresponding heat transfer coefficient that was used for the film drop thermal calculation. Because of the superior nuclear performance, the acceptable thermal-hydraulic characteristics and the mechanical design feasibility, the plate geometry concept was chosen for the reference gas-cooled TMHR blanket design

  5. Thermal modeling of secondary lithium batteries for electric vehicle/hybrid electric vehicle applications

    Science.gov (United States)

    Al-Hallaj, Said; Selman, J. R.

    A major obstacle to the development of commercially successful electric vehicles (EV) or hybrid electric vehicles (HEV) is the lack of a suitably sized battery. Lithium ion batteries are viewed as the solution if only they could be "scaled-up safely", i.e. if thermal management problems could be overcome so the batteries could be designed and manufactured in much larger sizes than the commercially available near-2-Ah cells. Here, we review a novel thermal management system using phase-change material (PCM). A prototype of this PCM-based system is presently being manufactured. A PCM-based system has never been tested before with lithium-ion (Li-ion) batteries and battery packs, although its mode of operation is exceptionally well suited for the cell chemistry of the most common commercially available Li-ion batteries. The thermal management system described here is intended specifically for EV/HEV applications. It has a high potential for providing effective thermal management without introducing moving components. Thereby, the performance of EV/HEV batteries may be improved without complicating the system design and incurring major additional cost, as is the case with "active" cooling systems requiring air or liquid circulation.

  6. Thermal analysis of the cryocooled superconducting magnet for the liquid helium-free hybrid magnet

    International Nuclear Information System (INIS)

    Ishizuka, Masayuki; Hamajima, Takataro; Itou, Tomoyuki; Sakuraba, Junji; Nishijima, Gen; Awaji, Satoshi; Watanabe, Kazuo

    2010-01-01

    The liquid helium-free hybrid magnet, which consists of an outer large bore cryocooled superconducting magnet and an inner water-cooled resistive magnet, was developed for magneto-science in high fields. The characteristic features of the cryogen-free outsert superconducting magnet are described in detail in this paper. The superconducting magnet cooled by Gifford-McMahon cryocoolers, which has a 360 mm room temperature bore in diameter, was designed to generate high magnetic fields up to 10 T. The hybrid magnet has generated the magnetic field of 27.5 T by combining 8.5 T generation of the cryogen-free superconducting magnet with 19 T generation of the water-cooled resistive magnet. The superconducting magnet was composed of inner Nb 3 Sn coils and outer NbTi coils. In particular, inner Nb 3 Sn coils were wound using high-strength CuNi-NbTi/Nb 3 Sn wires in consideration of large hoop stress. Although the cryocooled outsert superconducting magnet achieved 9.5 T, we found that the outsert magnet has a thermal problem to generate the designed maximum field of 10 T in the hybrid magnet operation. This problem is associated with unexpected AC losses in Nb 3 Sn wires.

  7. Tunable thermal rectification in graphene/hexagonal boron nitride hybrid structures

    Science.gov (United States)

    Chen, Xue-Kun; Hu, Ji-Wen; Wu, Xi-Jun; Jia, Peng; Peng, Zhi-Hua; Chen, Ke-Qiu

    2018-02-01

    Using non-equilibrium molecular dynamics simulations, we investigate thermal rectification (TR) in graphene/hexagonal boron nitride (h-BN) hybrid structures. Two different structural models, partially substituting graphene into h-BN (CBN) and partially substituting h-BN into graphene (BNC), are considered. It is found that CBN has a significant TR effect while that of BNC is very weak. The observed TR phenomenon can be attributed to the resonance effect between out-of-plane phonons of graphene and h-BN domains in the low-frequency region under negative temperature bias. In addition, the influences of ambient temperature, system size, defect number and substrate interaction are also studied to obtain the optimum conditions for TR. More importantly, the TR ratio could be effectively tuned through chemical and structural diversity. A moderate C/BN ratio and parallel arrangement are found to enhance the TR ratio. Detailed phonon spectra analyses are conducted to understand the thermal transport behavior. This work extends hybrid engineering to 2D materials for achieving TR.

  8. Phonon properties and slow organic-to-inorganic sub-lattice thermalization in hybrid perovskites

    Science.gov (United States)

    Chan, Maria; Chang, Angela; Xia, Yi; Sadasivam, Sridhar; Guo, Peijun; Kinaci, Alper; Lin, Hao-Wu; Darancet, Pierre; Schaller, Richard

    Organic-inorganic hybrid perovskite halide compounds have been investigated extensively for photovoltaics (PVs) and related applications. The thermal transport properties of hybrid perovskites, including phonon-carrier and phonon-phonon interactions, are of significance for their PV and solar thermoelectric applications. The interlocking organic and inorganic sublattices can be thought of as an extreme form of nanostructuring. A result of this nanostructuring is the large gap in phonon frequencies between the organic and inorganic sublattices, which is expected to create bottlenecks in phonon equilibration. In this work, we use a combination of ultrafast spectroscopy including photoluminescence and transient absorption, as well as first principles density functional theory (DFT), ab initio molecular dynamics calculations, phonon lifetimes derived from DFT force constants, and non-equilibrium phonon dynamics accounting for phonon lifetimes, to determine the phonon and charge interaction processes. We find evidence that thermalization of carriers occur at an atypically slow 50-100 ps time scale owing to the complex interplay between electronic and phonon excitations.

  9. An efficient chaos embedded hybrid approach for hydro-thermal unit commitment problem

    International Nuclear Information System (INIS)

    Yuan, Xiaohui; Ji, Bin; Yuan, Yanbin; Ikram, Rana M.; Zhang, Xiaopan; Huang, Yuehua

    2015-01-01

    Highlights: • Thermal unit commitment is considered in hydrothermal generation scheduling (SHTGS). • Two newly proposed promising optimization algorithms are combined to solving SHTGS. • The proposed method is enhanced by integrating a chaotic local search strategy. • Heuristic search strategies are applied to handle the constraints of the SHTGS. • The results verify the proposed method is feasible and efficient for handling SHTGS. - Abstract: This paper establishes a model to deal with the short-term hydrothermal generation scheduling (SHTGS) problem. The problem is composed of three interconnected parts: short-term hydrothermal coordination, thermal unit commitment and economic load dispatch. An efficient hybrid method composed of chaotic backtracking search optimization algorithm and binary charged system search algorithm (CBSA–BCSS) is proposed to solve this problem. In order to analyze the effect of the chaotic map on the performance of the method, three different chaotic maps are adopted to integrate into the proposed method and the corresponding consequences are achieved. Furthermore, efficient heuristic search strategies are adopted to handle with the complicated constraints of the SHTGS system. Finally, a hydrothermal unit commitment system is utilized to verify the feasibility and effectiveness of the proposed method. The results demonstrate the efficiency of the hybrid optimization method and the appropriation of the constraint handling strategies. The comparison of the solutions achieved by different methods shows that the proposed method has higher efficiency in terms of solving SHTGS problem

  10. Experimental research on thermal characteristics of a hybrid thermocline heat storage system

    International Nuclear Information System (INIS)

    Yin, Huibin; Ding, Jing; Yang, Xiaoxi

    2014-01-01

    Considering the high-temperature thermal utilization of solar energy as the research background in this paper and focussing on the heat storage process, a kind of hybrid thermocline heat storage method in multi-scale structure and relevant experimental systems are designed by using the mixed molten nitrate salt as the heat storage medium and two representative porous materials, i.e. zirconium ball and silicon carbide (SiC) foam, as the heat storage fillers. The fluid flow and heat storage performance of molten salt in multi-scale structure are experimentally investigated. The results show that the theoretical heat storage efficiencies amongst the three experimental heat storage manners are less than 80% because of the existence of thermocline layers. Comparing to the single-phase molten salt heat storage, the two hybrid thermocline heat storage manners with porous fillers lead to a certain decrease in the effective heat storage capacity. The presence of porous fillers can also help to maintain the molten salt fluid as ideal gravity flow or piston flow and partially replace expensive molten salt. Therefore, it requires a combination of heat storage capacity and economical consideration for optimization design when similar spherical particles or foam ceramics are employed as the porous fillers. -- Highlights: • A hybrid thermocline heat storage method in multi-scale structure is developed. • The fluid flow and heat storage performance are experimentally investigated. • Stable thermocline can form in single tank for the experimental cases. • The hybrid thermocline heat storage with porous filler is promising

  11. Thermal properties of a large-bore cryocooled 10 T superconducting magnet for a hybrid magnet

    International Nuclear Information System (INIS)

    Ishizuka, M.; Hamajima, T.; Itou, T.; Sakuraba, J.; Nishijima, G.; Awaji, S.; Watanabe, K.

    2010-01-01

    A cryocooled 10 T superconducting magnet with a 360 mm room temperature bore has been developed for a hybrid magnet. The superconducting magnet cooled by four Gifford-McMahon cryocoolers has been designed to generate a magnetic field of 10 T. Since superconducting wires composed of coils were subjected to large hoop stress over 150 MPa and Nb 3 Sn superconducting wires particularly showed a low mechanical strength due to those brittle property, Nb 3 Sn wires strengthened by NbTi-filaments were developed for the cryocooled superconducting magnet. We have already reported that the hybrid magnet could generate the resultant magnetic field of 27.5 T by adding 8.5 T from the superconducting magnet and 19 T from a water-cooled Bitter resistive magnet, after the water-cooled resistive magnet was inserted into the 360 mm room temperature bore of the cryocooled superconducting magnet. When the hybrid magnet generated the field of 27.5 T, it achieved the high magnetic-force field (B x ∂Bz/∂z) of 4500 T 2 /m, which was useful for magneto-science in high fields such as materials levitation research. In this paper, we particularly focus on the cause that the cryocooled superconducting magnet was limited to generate the designed magnetic field of 10 T in the hybrid magnet operation. As a result, it was found that there existed mainly two causes as the limitation of the magnetic field generation. One was a decrease of thermal conductive passes due to exfoliation from the coil bobbin of the cooling flange. The other was large AC loss due to both a thick Nb 3 Sn layer and its large diameter formed on Nb-barrier component in Nb 3 Sn wires.

  12. A hybrid thermal video and FTIR spectrometer system for rapidly locating and characterizing gas leaks

    Science.gov (United States)

    Williams, David J.; Wadsworth, Winthrop; Salvaggio, Carl; Messinger, David W.

    2006-08-01

    Undiscovered gas leaks, known as fugitive emissions, in chemical plants and refinery operations can impact regional air quality and present a loss of product for industry. Surveying a facility for potential gas leaks can be a daunting task. Industrial leak detection and repair programs can be expensive to administer. An efficient, accurate and cost effective method for detecting and quantifying gas leaks would both save industries money by identifying production losses and improve regional air quality. Specialized thermal video systems have proven effective in rapidly locating gas leaks. These systems, however, do not have the spectral resolution for compound identification. Passive FTIR spectrometers can be used for gas compound identification, but using these systems for facility surveys is problematic due to their small field of view. A hybrid approach has been developed that utilizes the thermal video system to locate gas plumes using real time visualization of the leaks, coupled with the high spectral resolution FTIR spectrometer for compound identification and quantification. The prototype hybrid video/spectrometer system uses a sterling cooled thermal camera, operating in the MWIR (3-5 μm) with an additional notch filter set at around 3.4 μm, which allows for the visualization of gas compounds that absorb in this narrow spectral range, such as alkane hydrocarbons. This camera is positioned alongside of a portable, high speed passive FTIR spectrometer, which has a spectral range of 2 - 25 μm and operates at 4 cm -1 resolution. This system uses a 10 cm telescope foreoptic with an onboard blackbody for calibration. The two units are optically aligned using a turning mirror on the spectrometer's telescope with the video camera's output.

  13. A hybrid optimization model of biomass trigeneration system combined with pit thermal energy storage

    International Nuclear Information System (INIS)

    Dominković, D.F.; Ćosić, B.; Bačelić Medić, Z.; Duić, N.

    2015-01-01

    Highlights: • Hybrid optimization model of biomass trigeneration system with PTES is developed. • Influence of premium feed-in tariffs on trigeneration systems is assessed. • Influence of total system efficiency on biomass trigeneration system with PTES is assessed. • Influence of energy savings on project economy is assessed. - Abstract: This paper provides a solution for managing excess heat production in trigeneration and thus, increases the power plant yearly efficiency. An optimization model for combining biomass trigeneration energy system and pit thermal energy storage has been developed. Furthermore, double piping district heating and cooling network in the residential area without industry consumers was assumed, thus allowing simultaneous flow of the heating and cooling energy. As a consequence, the model is easy to adopt in different regions. Degree-hour method was used for calculation of hourly heating and cooling energy demand. The system covers all the yearly heating and cooling energy needs, while it is assumed that all the electricity can be transferred to the grid due to its renewable origin. The system was modeled in Matlab© on hourly basis and hybrid optimization model was used to maximize the net present value (NPV), which was the objective function of the optimization. Economic figures become favorable if the economy-of-scale of both power plant and pit thermal energy storage can be utilized. The results show that the pit thermal energy storage was an excellent option for storing energy and shaving peaks in energy demand. Finally, possible switch from feed-in tariffs to feed-in premiums was assessed and possible subsidy savings have been calculated. The savings are potentially large and can be used for supporting other renewable energy projects

  14. Influence of rf-magnetron Sputtered ITO and Al:ZnO on Photovoltaic Behaviour Related to CuInSe2-Based Photovoltaic Solar Cells

    International Nuclear Information System (INIS)

    Martinez, M.A.; Guillen, C; Dona, J. M.; Herrero, J; Gutierrez, M. T.

    2000-01-01

    This paper describes several investigations, made in the CIEMAT, on the capability of depositing transparent conducting oxides at room temperature by rf-magnetron sputtering, and their application in CuInSe 2 -based photovoltaic solar cells. ITO and Al:ZnO thin films having simultaneously high transmittance in the visible range and low resistivity, 10 3 -10 - 4 Ωcm, can be obtained only if oxygen mass-flow rate is constrained to a very narrow range (0.5 - 1 sccm). Cell efficiency enhance when transparent conducting oxides are made without intentional heating and, after, the total devices are annealed in air at 200 degree centigree. (Author) 40 refs

  15. The photovoltaic solar technology in a semi-arid Piaui region: case study; A tecnologia solar fotovoltaica no semi-arido piauiense: estudo de caso

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, Albemerc Moura de; Trigoso, Federico B. Morante [Universidade Federal do ABC (UFABC), Santo Andre, SP (Brazil). Centro de Engenharia, Modelagem e Ciencias Sociais Aplicadas. Programa de Pos Graduacao em Energia

    2008-07-01

    The following work has as objective to present some results of a research of field carried through in the Piaui semi-arid region that it aimed at to verify the use of the photovoltaic solar technology. For this six questionnaires in three rural communities of three municipal territories of the State in the valley of the river Caninde had been applied. It was verified that due to lack of maintenance of these systems good part of them left to still function in the first years of its installation. Although this almost all the interviewed ones had revealed signal of approval to the electric energy proceeding from these systems for the community use, however they had questioned the lack of maintenance of these and had revealed interested in possessing access in its residences of this so important good is useful, the electricity. (author)

  16. Continuous Carbon Nanotube-Ultrathin Graphite Hybrid Foams for Increased Thermal Conductivity and Suppressed Subcooling in Composite Phase Change Materials.

    Science.gov (United States)

    Kholmanov, Iskandar; Kim, Jaehyun; Ou, Eric; Ruoff, Rodney S; Shi, Li

    2015-12-22

    Continuous ultrathin graphite foams (UGFs) have been actively researched recently to obtain composite materials with increased thermal conductivities. However, the large pore size of these graphitic foams has resulted in large thermal resistance values for heat conduction from inside the pore to the high thermal conductivity graphitic struts. Here, we demonstrate that the effective thermal conductivity of these UGF composites can be increased further by growing long CNT networks directly from the graphite struts of UGFs into the pore space. When erythritol, a phase change material for thermal energy storage, is used to fill the pores of UGF-CNT hybrids, the thermal conductivity of the UGF-CNT/erythritol composite was found to increase by as much as a factor of 1.8 compared to that of a UGF/erythritol composite, whereas breaking the UGF-CNT bonding in the hybrid composite resulted in a drop in the effective room-temperature thermal conductivity from about 4.1 ± 0.3 W m(-1) K(-1) to about 2.9 ± 0.2 W m(-1) K(-1) for the same UGF and CNT loadings of about 1.8 and 0.8 wt %, respectively. Moreover, we discovered that the hybrid structure strongly suppresses subcooling of erythritol due to the heterogeneous nucleation of erythritol at interfaces with the graphitic structures.

  17. Microstructural, mechanical, and thermal characteristics of recycled cellulose fiber-halloysite-epoxy hybrid nanocomposites

    KAUST Repository

    Alamri, H.

    2012-02-26

    Epoxy hybrid-nanocomposites reinforced with recycled cellulose fibers (RCF) and halloysite nanotubes (HNTs) have been fabricated and investigated. The dispersion of HNTs was studied by synchrotron radiation diffraction (SRD) and transmission electron microscopy (TEM). The influences of RCF/HNTs dispersion on the mechanical properties and thermal properties of these composites have been characterized in terms of flexural strength, flexural modulus, fracture toughness, impact toughness, impact strength, and thermogravimetric analysis. The fracture surface morphology and toughness mechanisms were investigated by SEM. Results indicated that mechanical properties increased because of the addition of HNTs into the epoxy matrix. Flexural strength, flexural modulus, fracture toughness, and impact toughness increased by 20.8, 72.8, 56.5, and 25.0%, respectively, at 1 wt% HNTs load. The presence of RCF dramatically enhanced flexural strength, fracture toughness, impact strength, and impact toughness of the composites by 160%, 350%, 444%, and 263%, respectively. However, adding HNTs to RCF/epoxy showed only slight enhancements in flexural strength and fracture toughness. The inclusion of 5 wt% HNTs into RCF/epoxy ecocomposites increased the impact toughness by 27.6%. The presence of either HNTs or RCF accelerated the thermal degradation of neat epoxy. However, at high temperature, samples reinforced with RCF and HNTs displayed better thermal stability with increased char residue than neat resin. © 2012 Society of Plastics Engineers.

  18. Integration of plug-in hybrid electric vehicles in a regional wind-thermal power system

    International Nuclear Information System (INIS)

    Goeransson, Lisa; Karlsson, Sten; Johnsson, Filip

    2010-01-01

    This study investigates consequences of integrating plug-in hybrid electric vehicles (PHEVs) in a wind-thermal power system supplied by one quarter of wind power and three quarters of thermal generation. Four different PHEV integration strategies, with different impacts on the total electric load profile, have been investigated. The study shows that PHEVs can reduce the CO 2 -emissions from the power system if actively integrated, whereas a passive approach to PHEV integration (i.e. letting people charge the car at will) is likely to result in an increase in emissions compared to a power system without PHEV load. The reduction in emissions under active PHEV integration strategies is due to a reduction in emissions related to thermal plant start-ups and part load operation. Emissions of the power sector are reduced with up to 4.7% compared to a system without PHEVs, according to the simulations. Allocating this emission reduction to the PHEV electricity consumption only, and assuming that the vehicles in electric mode is about 3 times as energy efficient as standard gasoline operation, total emissions from PHEVs would be less than half the emissions of a standard car, when running in electric mode.

  19. Synthesis and electrical characterization of low-temperature thermal-cured epoxy resin/functionalized silica hybrid-thin films for application as gate dielectrics

    Energy Technology Data Exchange (ETDEWEB)

    Na, Moonkyong, E-mail: nmk@keri.re.kr [HVDC Research Division, Korea Electrotechnology Research Institute, Changwon, 642-120 (Korea, Republic of); System on Chip Chemical Process Research Center, Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 790-784 (Korea, Republic of); Kang, Young Taec [Creative and Fundamental Research Division, Korea Electrotechnology Research Institute, Changwon, 642-120 (Korea, Republic of); Department of Polymer Science and Engineering, Pusan National University, Busan, 609-735 (Korea, Republic of); Kim, Sang Cheol [HVDC Research Division, Korea Electrotechnology Research Institute, Changwon, 642-120 (Korea, Republic of); Kim, Eun Dong [Creative and Fundamental Research Division, Korea Electrotechnology Research Institute, Changwon, 642-120 (Korea, Republic of)

    2013-07-31

    Thermal-cured hybrid materials were synthesized from homogenous hybrid sols of epoxy resins and organoalkoxysilane-functionalized silica. The chemical structures of raw materials and obtained hybrid materials were characterized using Fourier transform infrared spectroscopy. The thermal resistance of the hybrids was enhanced by hybridization. The interaction between epoxy matrix and the silica particles, which caused hydrogen bonding and van der Waals force was strengthened by organoalkoxysilane. The degradation temperature of the hybrids was improved by approximately 30 °C over that of the parent epoxy material. The hybrid materials were formed into uniformly coated thin films of about 50 nm-thick using a spin coater. An optimum mixing ratio was used to form smooth-surfaced hybrid films. The electrical property of the hybrid film was characterized, and the leakage current was found to be well below 10{sup −6} A cm{sup −2}. - Highlights: • Preparation of thermal-curable hybrid materials using epoxy resin and silica. • The thermal stability was enhanced through hybridization. • The insulation property of hybrid film was investigated as gate dielectrics.

  20. Effect of hybrid UV-thermal energy stimuli on inactivation of S. epidermidis andB. subtilis bacterial bioaerosols

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Gi Byoung; Jung, Jae Hee; Jeong, Tae Gun; Lee, Byung Uk, E-mail: leebu@konkuk.ac.kr [Aerosol and Bioengineering Laboratory, Department of Mechanical Engineering, Konkuk University, 1 Hwayang-dong, Gwangjin-Gu, Seoul, 143-701(Korea, Republic of)

    2010-11-01

    Bioaerosols have become an increasingly important issue due to their harmful effects on human health. As the concern over airborne microorganisms grows, so does the need to develop and study efficient methods of controlling them. In this study, we designed a hybrid system involving ultraviolet (UV) irradiation and thermal energy and investigated its effects on bacterial bioaerosols, followed by a comparison with thermal energy alone and UV irradiation alone. The results show that the hybrid effect caused no variation in the shape of the normalized particle size distributions of S. epidermidis and B. subtilis bioaerosols. However, a physical transport loss of bacterial bioaerosols developed as the temperature inside the glass quartz tube increased. When bacterial bioaerosols were simultaneously exposed to UV irradiation and thermal energy for less than 1.05 s, more than 99% of S. epidermidis bioaerosols were inactivated at 120 {sup o}C with exposure to one UV lamp and at 80 {sup o}C with exposure to two UV lamps; and 93.5% and 98.5% of B. subtilis bioaerosols were inactivated at 280 {sup o}C with exposure to one and two UV lamps, respectively. Moreover, the hybrid UV-thermal stimuli significantly reduced the concentration of ozone, which is a secondary UV-induced pollutant. Our results show that to obtain the same inactivation efficiency, the hybrid UV-thermal stimuli were more efficient than thermal energy alone in terms of energy consumption and produced significantly less ozone than UV irradiation alone. The hybrid stimuli also had higher inactivation efficiency than UV alone. Therefore, these results provide valuable information for the development of new methods for controlling bioaerosols.

  1. Performance analysis of different ORC configurations for thermal energy and LNG cold energy hybrid power generation system

    Science.gov (United States)

    Sun, Zhixin; Wang, Feng; Wang, Shujia; Xu, Fuquan; Lin, Kui

    2017-01-01

    This paper presents a thermal energy and Liquefied natural gas (LNG) cold energy hybrid power generation system. Performances of four different Organic Rankine cycle (ORC) configurations (the basic, the regenerative, the reheat and the regenerative-reheat ORCs) are studied based on the first and the second law of thermodynamics. Dry organic fluid R245fa is selected as the typical working fluid. Parameter analysis is also conducted in this paper. The results show that regeneration could not increase the thermal efficiency of the thermal and cold energy hybrid power generation system. ORC with the reheat process could produce more specific net power output but it may also reduce the system thermal efficiency. The basic and the regenerative ORCs produce higher thermal efficiency while the regenerative-reheat ORC performs best in the exergy efficiency. A preheater is necessary for the thermal and cold energy hybrid power generation system. And due to the presence of the preheater, there will be a step change of the system performance as the turbine inlet pressure rises.

  2. Solution of wind integrated thermal generation system for environmental optimal power flow using hybrid algorithm

    Directory of Open Access Journals (Sweden)

    Ambarish Panda

    2016-09-01

    Full Text Available A new evolutionary hybrid algorithm (HA has been proposed in this work for environmental optimal power flow (EOPF problem. The EOPF problem has been formulated in a nonlinear constrained multi objective optimization framework. Considering the intermittency of available wind power a cost model of the wind and thermal generation system is developed. Suitably formed objective function considering the operational cost, cost of emission, real power loss and cost of installation of FACTS devices for maintaining a stable voltage in the system has been optimized with HA and compared with particle swarm optimization algorithm (PSOA to prove its effectiveness. All the simulations are carried out in MATLAB/SIMULINK environment taking IEEE30 bus as the test system.

  3. Day-Ahead Self-Scheduling of Thermal Generator in Competitive Electricity Market Using Hybrid PSO

    DEFF Research Database (Denmark)

    Pindoriya, N.M.; Singh, Sri Niwas; Østergaard, Jacob

    2009-01-01

    in day-ahead energy market subject to operational constraints and 2) at the same time, to minimize the risk due to uncertainty in price forecast. Therefore, it is a conflicting biobjective optimization problem which has both binary and continuous optimization variables considered as constrained mixed......This paper presents a hybrid particle swarm optimization algorithm (HPSO) to solve the day-ahead selfscheduling for thermal power producer in competitive electricity market. The objective functions considered to model the selfscheduling problem are: 1) to maximize the profit from selling energy...... integer nonlinear programming. To demonstrate the effectiveness of the proposed method for self-scheduling in a dayahead energy market, the locational margin price (LMP) forecast uncertainty in PJM electricity market is considered. An adaptive wavelet neural network (AWNN) is used to forecast the dayahead...

  4. Development of a field measurement methodology for studying the thermal indoor environment in hybrid GEOTABS buildings

    DEFF Research Database (Denmark)

    Kazanci, Ongun Berk; Khovalyg, Dolaana; Olesen, Bjarne W.

    2018-01-01

    buildings. The three demonstration buildings were an office building in Luxembourg, an elderly care home in Belgium, and an elementary school in Czech Republic. All of these buildings are equipped with hybrid GEOTABS systems; however, they vary in size and function, which requires a unique measurement...... methodology for studying them. These buildings already have advanced Building Management Systems (BMS); however, a more detailed measurement plan was needed for the purposes of the project to document the current performance of these systems regarding thermal indoor environment and energy performance......, and to be able to document the improvements after the implementation of the MPC. This study provides the details of the developed field measurement methodology for each of these buildings to study the indoor environmental quality (IEQ) in details. The developed measurement methodology can be applied to other...

  5. Reduced thermal sensitivity of hybrid air-core photonic band-gap fiber ring resonator

    Science.gov (United States)

    Feng, Li-shuang; Wang, Kai; Jiao, Hong-chen; Wang, Jun-jie; Liu, Dan-ni; Yang, Zhao-hua

    2018-01-01

    A novel hybrid air-core photonic band-gap fiber (PBF) ring resonator with twin 90° polarization-axis rotated splices is proposed and demonstrated. Frist, we measure the temperature dependent birefringence coefficient of air-core PBF and Panda fiber. Experimental results show that the relative temperature dependent birefringence coefficient of air-core PBF is 1.42×10-8/°C, which is typically 16 times less than that of Panda fiber. Then, we extract the geometry profile of air-core PBF from scanning electron microscope (SEM) images. Numerical modal is built to distinguish the fast axis and slow axis in the fiber. By precisely setting the length difference in air-core PBF and Panda fiber between two 90° polarization-axis rotated splicing points, the hybrid air-core PBF ring resonator is constructed, and the finesse of the resonator is 8.4. Environmental birefringence variation induced by temperature change can be well compensated, and experimental results show an 18-fold reduction in thermal sensitivity, compared with resonator with twin 0° polarization-axis rotated splices.

  6. Dynamic Mechanical and Thermal Properties of Bagasse/Glass Fiber/Polypropylene Hybrid Composites

    Directory of Open Access Journals (Sweden)

    Mehdi Roohani

    2016-06-01

    Full Text Available This work aims to evaluate the thermal and dynamic mechanical properties of bagasse/glass fiber/polypropylene hybrid composites. Composites were prepared by the melt compounding method and their properties were characterized by differential scanning calorimetry (DSC and dynamic mechanical analysis (DMA. DSC results found that with incorporation of bagasse and glass fiber the melting temperature (Tm and the crystallisation temperature (Tc shift to higher temperatures and the degree of crystallinity (Xc increase. These findings suggest that the fibers played the role of a nucleating agent in composites. Dynamic mechanical analysis indicated that by the incorporation of bagasse and glass fiber into polypropylene, the storage modulus ( and the loss modulus ( increase whereas the mechanical loss factor (tanδ decrease. To assess the effect of reinforcement with increasing temperature, the effectiveness coefficient C was calculated at different temperature ranges and revealed that, at the elevated temperatures, improvement of mechanical properties due to the presence of fibers was more noticeable. The fiber-matrix adhesion efficiency determined by calculating of adhesion factor A in terms of the relative damping of the composite (tan δc and the polymer (tan δpand volume fraction of the fibers (Фf. Calculated adhesion factor A values indicated that by adding glass fiber to bagasse/polypropylene system, the fiber-matrix adhesion improve. Hybrid composite containing 25% bagasse and 15% glass fiber showed better fiber-matrix adhesion.

  7. The energetic performance of a novel hybrid solar thermal and chemical looping combustion plant

    International Nuclear Information System (INIS)

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

    2014-01-01

    Highlights: • A hybrid solar chemical looping combustion power cycle is reported. • The cycle is studied for two configurations, with and without an after-burner. • The oxygen carrier particles are used as storage medium for solar thermal energy. • Total solar shares of 41.4% and 60% are achieved with and without the after-burner. • Efficiencies of 50% and 44.0% are achieved with and without the after-burner. - Abstract: The overall energetic performance of a gas turbine combined cycle powered by a hybrid cycle between a solar thermal and a chemical looping combustion (CLC) system firing methane is reported for two configurations. In one case, the outlet from the air reactor is fed directly to a gas turbine, while in the other an after-burner, also firing methane, is added to increase the gas turbine inlet temperature. The cycle is simulated using Aspen Plus software for the average diurnal profile of normal irradiance for Port Augusta, South Australia. The first law efficiency, total solar absorption efficiency, average and peak fractional power boosts, total solar share, net solar to electrical efficiency, fraction of pressurised CO 2 , incremental CO 2 avoidance and the exergy efficiency for both cycles are reported. The calculations predict a first law efficiency of 50.0% for the cycle employing an after-burner, compared with 44.0% for that without the after-burner. However, this is achieved at the cost of decreasing the solar share from 60.0%, without the after-burner, to 41.4% with it. Also reported is the sensitivity analysis of performance to variations in key operating parameters. The sensitivity analysis shows that further improvements to the performance of the cycle are possible

  8. Hybrid electric vehicle thermal management and study of the power electronics cooling; Gestion thermique du vehicule hybride et etude du refroidissement de l'electronique de puissance

    Energy Technology Data Exchange (ETDEWEB)

    Rouaud, C.

    2004-07-01

    For decreasing the engine's consumption and pollutant emissions, automobile makers are developing hybrid electric vehicles incorporating an electric motor and power electronics leading to new under-hood thermal constraints. This is why we first present the tests results of a new common cooling circuit for all the vehicle components. With the aim of developing new energy management strategies between the components, we have chosen the nodal method to simulate the thermal behaviour of the engine, the electric motor, the power electronics and the cooling circuit. The second part of this thesis deals with a thermal-hydraulic analysis of several power electronics cooling methods, which has led us to choose the multiple jet impingement cooling. Several tests have been made for characterising the performances of this technique and enabled us to establish an optimal configuration. The last part shows the thermal simulation results run with the help of an innovative reduction method of thermal models applied to the power electronics. This technique allowed us to have a low cost of time simulation and will permit, in the future, the real-time control of the hybrid electric vehicle components. (author)

  9. Analysis of the mechanical and thermal properties of jute and glass fiber as reinforcement epoxy hybrid composites.

    Science.gov (United States)

    Braga, R A; Magalhaes, P A A

    2015-11-01

    This work describes the study to investigate and compare the mechanical and thermal properties of raw jute and glass fiber reinforced epoxy hybrid composites. To improve the mechanical properties, jute fiber was hybridized with glass fiber. Epoxy resin, jute and glass fibers were laminated in three weight ratios (69/31/0, 68/25/7 and 64/18/19) respectively to form composites. The tensile, flexural, impact, density, thermal and water absorption tests were carried out using hybrid composite samples. This study shows that the addition of jute fiber and glass fiber in epoxy, increases the density, the impact energy, the tensile strength and the flexural strength, but decreases the loss mass in function of temperature and the water absorption. Morphological analysis was carried out to observe fracture behavior and fiber pull-out of the samples using scanning electron microscope. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Physical and JIT Model Based Hybrid Modeling Approach for Building Thermal Load Prediction

    Science.gov (United States)

    Iino, Yutaka; Murai, Masahiko; Murayama, Dai; Motoyama, Ichiro

    Energy conservation in building fields is one of the key issues in environmental point of view as well as that of industrial, transportation and residential fields. The half of the total energy consumption in a building is occupied by HVAC (Heating, Ventilating and Air Conditioning) systems. In order to realize energy conservation of HVAC system, a thermal load prediction model for building is required. This paper propose a hybrid modeling approach with physical and Just-in-Time (JIT) model for building thermal load prediction. The proposed method has features and benefits such as, (1) it is applicable to the case in which past operation data for load prediction model learning is poor, (2) it has a self checking function, which always supervises if the data driven load prediction and the physical based one are consistent or not, so it can find if something is wrong in load prediction procedure, (3) it has ability to adjust load prediction in real-time against sudden change of model parameters and environmental conditions. The proposed method is evaluated with real operation data of an existing building, and the improvement of load prediction performance is illustrated.

  11. Simulation of Thermal Flow Problems via a Hybrid Immersed Boundary-Lattice Boltzmann Method

    Directory of Open Access Journals (Sweden)

    J. Wu

    2012-01-01

    Full Text Available A hybrid immersed boundary-lattice Boltzmann method (IB-LBM is presented in this work to simulate the thermal flow problems. In current approach, the flow field is resolved by using our recently developed boundary condition-enforced IB-LBM (Wu and Shu, (2009. The nonslip boundary condition on the solid boundary is enforced in simulation. At the same time, to capture the temperature development, the conventional energy equation is resolved. To model the effect of immersed boundary on temperature field, the heat source term is introduced. Different from previous studies, the heat source term is set as unknown rather than predetermined. Inspired by the idea in (Wu and Shu, (2009, the unknown is calculated in such a way that the temperature at the boundary interpolated from the corrected temperature field accurately satisfies the thermal boundary condition. In addition, based on the resolved temperature correction, an efficient way to compute the local and average Nusselt numbers is also proposed in this work. As compared with traditional implementation, no approximation for temperature gradients is required. To validate the present method, the numerical simulations of forced convection are carried out. The obtained results show good agreement with data in the literature.

  12. Investigation of Solar Hybrid Electric/Thermal System with Radiation Concentrator and Thermoelectric Generator

    Directory of Open Access Journals (Sweden)

    Edgar Arturo Chávez Urbiola

    2013-01-01

    Full Text Available An experimental study of a solar-concentrating system based on thermoelectric generators (TEGs was performed. The system included an electrical generating unit with 6 serially connected TEGs using a traditional semiconductor material, Bi2Te3, which was illuminated by concentrated solar radiation on one side and cooled by running water on the other side. A sun-tracking concentrator with a mosaic set of mirrors was used; its orientation towards the sun was achieved with two pairs of radiation sensors, a differential amplifier, and two servomotors. The hot side of the TEGs at midday has a temperature of around 200°C, and the cold side is approximately 50°C. The thermosiphon cooling system was designed to absorb the heat passing through the TEGs and provide optimal working conditions. The system generates 20 W of electrical energy and 200 W of thermal energy stored in water with a temperature of around 50°C. The hybrid system studied can be considered as an alternative to photovoltaic/thermal systems, especially in countries with abundant solar radiation, such as Mexico, China, and India.

  13. Largely enhanced thermal and mechanical properties of polymer nanocomposites via incorporating C60@graphene nanocarbon hybrid

    International Nuclear Information System (INIS)

    Song, Ping’an; Liu, Lina; Yu, Youming; Huang, Guobo; Guo, Qipeng

    2013-01-01

    Although considerable progress has been achieved to create advanced polymer nanocomposites using nanocarbons including fullerene (C 60 ) and graphene, it remains a major challenge to effectively disperse them in a polymer matrix and to fully exert their extraordinary properties. Here we report a novel approach to fabricate the C 60 @graphene nanocarbon hybrid (C 60 : ∼47.9 wt%, graphene: ∼35.1%) via three-step reactions. The presence of C 60 on a graphene sheet surface can effectively prevent the aggregation of the latter which in turn helps the dispersion of the former in a polymer matrix during melt-processing. C 60 @graphene is found to be uniformly dispersed in a polypropylene (PP) matrix. Compared with pristine C 60 or graphene, C 60 @graphene further improves the thermal stability and mechanical properties of PP. The incorporation of 2.0 wt% C 60 @graphene (relative to PP) can remarkably increase the initial degradation temperature by around 59 ° C and simultaneously enhance the tensile strength and Young’s modulus by 67% and 76%, respectively, all of which are higher than those of corresponding PP/C 60 (graphene) nanocomposites. These significant performance improvements are mainly due to the free-radical-trapping effect of C 60 , and the thermal barrier and reinforcing effects of graphene nanosheets as well as the effective stress load transfer. This work provides a new methodology to design multifunctional nanohybrids for creating advanced materials. (paper)

  14. A review of concentrated photovoltaic-thermal (CPVT) hybrid solar systems with waste heat recovery (WHR)

    Institute of Scientific and Technical Information of China (English)

    Xing Ju; Chao Xu; Zhirong Liao; Xiaoze Du; Gaosheng Wei; Zhifeng Wang; Yongping Yang

    2017-01-01

    In conventional photovoltaic (PV) systems,a large portion of solar energy is dissipated as waste heat since the generating efficiency is usually less than 30%.As the dissipated heat can be recovered for various applications,the wasted heat recovery concentrator PV/thermal (WHR CPVT) hybrid systems have been developed.They can provide both electricity and usable heat by combining thermal systems with concentrator PV (CPV) module,which dramatically improves the overall conversion efficiency of solar energy.This paper systematically and comprehensively reviews the research and development ofWHR CPVT systems.WHR CPVT systems with innovative design configurations,different theoretical evaluation models and experimental test processes for several implementations are presented in an integrated manner.We aim to provide a global point of view on the research trends,market potential,technical obstacles,and the future work which is required in the development of WHR CPVT technology.Possibly,it will offer a generic guide to the investigators who are interested in the study of WHR CPVT systems.

  15. Design, modeling and performance analysis of dual channel semitransparent photovoltaic thermal hybrid module in the cold environment

    International Nuclear Information System (INIS)

    Singh, Sonveer; Agrawal, Sanjay; Avasthi, D.V.

    2016-01-01

    Highlights: • Thermal modeling of novel dual channel semitransparent PVT hybrid module. • Exergy and carbon credit analysis has been performed. • Annual performance has been evaluated for Srinagar (India). • There are improvements in results for case-I as compared to case-II. - Abstract: In this work, thermal modeling and performance analysis of the dual channel semitransparent photovoltaic thermal (DCSPVT) module has been carried out. For extracting heat associated with the lower and upper surface of the solar cell, two channels have been proposed; (i) one is above the solar cell called upper channel and (ii) second is below the solar cell called lower channel. Firstly, thermal modeling of DCSPVT module has been developed. After that, performance analysis of the above system has been carried out for Srinagar, Indian climatic condition. Performance in terms of electrical gain (EG), thermal gain (TG), overall exergy gain (OEG), overall thermal gain (OTG), electrical efficiency (EE) and overall exergy efficiency (OEE) of the DCSPVT module (case-I) have been compared with single channel semitransparent photovoltaic thermal (SCSPVT) hybrid module (case-II). The average improvement in EG, TG, OEG, OTG of the case-I have been observed by 71.51%, 34.57%, 5.78% and 35.41% respectively as compared to case-II.

  16. Numerical analysis of using hybrid photovoltaic-thermal solar water heater in Iran

    Directory of Open Access Journals (Sweden)

    M Mohammadi Sarduei

    2017-05-01

    Full Text Available Introduction Electrical performance of solar cells decreases with increasing cell temperature, basically because of growth of the internal charge carrier recombination rates, caused by increased carrier concentrations. Hybrid Photovoltaic/thermal (PVT systems produce electrical and thermal energy simultaneously. PVT solar collectors convert the heat generated in the solar cells to low temperature useful heat energy and so they provide a lower working temperature for solar cells which subsequently leads to a higher electrical efficiency. Recently, in Iran, the reforming government policy in subsidy and increasing fossil fuels price led to growing an interest in use of renewable energies for residual and industrial applications. In spite of this, the PV power generator investment is not economically feasible, so far. Hybrid PVT devices are well known as an alternative method to improve energy performance and therefore economic feasibility of the conventional PV systems. The aim of this study is to investigate the performance of a PVT solar water heater in four different cities of Iran using TRNSYS program. Materials and Methods The designed PVT solar water system consists of two separate water flow circuits namely closed cycle and open circuit. The closed cycle circuit was comprised of a solar PVT collector (with nominal power of 880 W and area of 5.6 m2, a heat exchanger in the tank (with volume of 300 L, a pump and connecting pipes. The water stream in the collector absorbs the heat accumulated in the solar cells and delivers it to the water in the tank though the heat exchanger. An on/off controller system was used to activate the pump when the collector outlet temperature was higher than that of the tank in the closed cycle circuit. The water in the open circuit, comes from city water at low temperature, enters in the lower part of the storage tank where the heat transfer occurs between the two separate circuits. An auxiliary heater, connected

  17. Nd-Fe-B/Sm-M/Nd-M (M = Fe, Co, Ti, Cu, Zr) hybrid magnets with improved thermal stability

    Science.gov (United States)

    Grigoras, M.; Lostun, M.; Urse, M.; Borza, F.; Chiriac, H.; Lupu, N.

    2018-02-01

    Hybrid magnets of Nd12Fe82B6(2:14:1-phase)/Nd9.4Fe59Co25.3Ti6.3(3:29-phase) and Nd12Fe82B6/Sm11.1Co65.8Fe8.9Cu10.7Zr3.5(2:17-phase) with different weight ratio have been prepared by spark plasma sintering pressing technique from ball-milled powders obtained from melt-spun ribbons. Influence of the ratio between the two phases on the magnetic properties and thermal stability of the hybrid magnets was studied. It has been found that the ratio has a remarkable influence, especially on the thermal stability of the bulk magnets. However, the magnetic properties of such type of hybrid magnets result not only from the type and ratio of components but also from the interaction between them. It was found that in NdFeB/3:29 hybrid magnets with 15% content of 3:29-phase, the temperature coefficients of remanence (α) and of coercivity (β) are improved from -0.095 to -0.082 (%/°C) and from -0.57 to -0.47 (%/°C), respectively, as compared to the Nd2Fe14B single-phase counterpart. While for the NdFeB/2:17 hybrid magnets the content of 2:17-phase is not significantly influencing the temperature coefficient of induction (α), the temperature coefficient of °C (β) increases up to -0.41 (%/°C) for 10% content of 2:17-phase. The increase in the reversible temperature coefficients of hybrid magnets indicate a remarkable improvement of their thermal stability.

  18. A detailed thermal-electrical model of three photovoltaic/thermal (PV/T) hybrid air collectors and photovoltaic (PV) module: Comparative study under Algiers climatic conditions

    International Nuclear Information System (INIS)

    Slimani, Mohamed El Amine; Amirat, Madjid; Kurucz, Ildikó; Bahria, Sofiane; Hamidat, Abderrahmane; Chaouch, Wafa Braham

    2017-01-01

    Highlights: • A detailed thermal and electrical model for PV and PV/T systems has been presented. • The developed numerical model was validated successfully with previously published experimental results. • A comparative study between four solar devices (PV and PV/T systems) was carried out. • The experimental weather conditions of Algiers site are used in the numerical model. • The glazed double-pass photovoltaic/thermal air collector shows the best overall energy efficiency. - Abstract: The thermal photovoltaic hybrid collector is a genuine cogeneration technology; it can produce electricity and heat simultaneously. In this paper, a comparative study is presented between four solar device configurations: photovoltaic module (PV-I), conventional hybrid solar air collector (PV/T-II), glazed hybrid solar air collector (PV/T-III) and glazed double-pass hybrid solar air collector (PV/T-IV). A numerical model is developed and validated through experimental results indicated in the previous literature. The numerical model takes the heat balance equations and different thermal and electrical parameters into account for each configuration included in this study, the energy performances are evaluated with a sample weather data of Algiers site. The numerical results show that the daily average of overall energy efficiency reaches: 29.63%, 51.02%, 69.47% and 74% for the first (PV-I), the second (PV/T-II), the third (PV/T-III) and the fourth (PV/T-IV) configurations respectively. These values are obtained with an air flow of 0.023 kg/s and introducing a sample of experimental weather data collected in Algiers site for a sunny day in summer.

  19. A Crewed Mission to Apophis Using a Hybrid Bimodal Nuclear Thermal Electric Propulsion (BNTEP) System

    Science.gov (United States)

    Mccurdy, David R.; Borowski, Stanley K.; Burke, Laura M.; Packard, Thomas W.

    2014-01-01

    A BNTEP system is a dual propellant, hybrid propulsion concept that utilizes Bimodal Nuclear Thermal Rocket (BNTR) propulsion during high thrust operations, providing 10's of kilo-Newtons of thrust per engine at a high specific impulse (Isp) of 900 s, and an Electric Propulsion (EP) system during low thrust operations at even higher Isp of around 3000 s. Electrical power for the EP system is provided by the BNTR engines in combination with a Brayton Power Conversion (BPC) closed loop system, which can provide electrical power on the order of 100's of kWe. High thrust BNTR operation uses liquid hydrogen (LH2) as reactor coolant propellant expelled out a nozzle, while low thrust EP uses high pressure xenon expelled by an electric grid. By utilizing an optimized combination of low and high thrust propulsion, significant mass savings over a conventional NTR vehicle can be realized. Low thrust mission events, such as midcourse corrections (MCC), tank settling burns, some reaction control system (RCS) burns, and even a small portion at the end of the departure burn can be performed with EP. Crewed and robotic deep space missions to a near Earth asteroid (NEA) are best suited for this hybrid propulsion approach. For these mission scenarios, the Earth return V is typically small enough that EP alone is sufficient. A crewed mission to the NEA Apophis in the year 2028 with an expendable BNTEP transfer vehicle is presented. Assembly operations, launch element masses, and other key characteristics of the vehicle are described. A comparison with a conventional NTR vehicle performing the same mission is also provided. Finally, reusability of the BNTEP transfer vehicle is explored.

  20. Life cycle energy metrics and CO 2 credit analysis of a hybrid photovoltaic/thermal greenhouse dryer

    OpenAIRE

    P. Barnwal; G. N. Tiwari

    2008-01-01

    In this paper, life cycle energy metrics, such as energy payback time (EPBT), energy production factor (EPF) and life cycle conversion efficiency (LCCE), and mitigation of CO 2 emissions for a hybrid photovoltaic/thermal (PV/T) greenhouse dryer have been analyzed. The hybrid PV/T greenhouse (roof type even span) dryer, designed and constructed at Solar Energy Park, Indian Institute of Technology, New Delhi (28°35′N, 77°12′E, 216 m above MSL), India, has a 2.50 m × 2.60 m floor area, 1.80 m ce...

  1. Effect of stacking sequence and surface treatment on the thermal conductivity of multilayered hybrid nano-composites

    Science.gov (United States)

    Papanicolaou, G. C.; Pappa, E. J.; Portan, D. V.; Kotrotsos, A.; Kollia, E.

    2018-02-01

    The aim of the present investigation was to study the effect of both the stacking sequence and surface treatment on the thermal conductivity of multilayered hybrid nano-composites. Four types of multilayered hybrid nanocomposites were manufactured and tested: Nitinol- CNTs (carbon nanotubes)- Acrylic resin; Nitinol- Acrylic resin- CNTs; Surface treated Nitinol- CNTs- Acrylic resin and Surface treated Nitinol- Acrylic resin- CNTs. Surface treatment of Nitinol plies was realized by means of the electrochemical anodization. Surface topography of the anodized nitinol sheets was investigated through Scanning Electron Microscopy (SEM). It was found that the overall thermal response of the manufactured multilayered nano-composites was greatly influenced by both the anodization and the stacking sequence. A theoretical model for the prediction of the overall thermal conductivity has been developed considering the nature of the different layers, their stacking sequence as well as the interfacial thermal resistance. Thermal conductivity and Differential Scanning Calorimetry (DSC) measurements were conducted, to verify the predicted by the model overall thermal conductivities. In all cases, a good agreement between theoretical predictions and experimental results was found.

  2. Improved thermal conductivity of TiO2-SiO2 hybrid nanofluid in ethylene glycol and water mixture

    Science.gov (United States)

    Hamid, K. A.; Azmi, W. H.; Nabil, M. F.; Mamat, R.

    2017-10-01

    The need to study hybrid nanofluid properties such as thermal conductivity has increased recently in order to provide better understanding on nanofluid thermal properties and behaviour. Due to its ability to improve heat transfer compared to conventional heat transfer fluids, nanofluids as a new coolant fluid are widely investigated. This paper presents the thermal conductivity of TiO2-SiO2 nanoparticles dispersed in ethylene glycol (EG)-water. The TiO2-SiO2 hybrid nanofluids is measured for its thermal conductivity using KD2 Pro Thermal Properties Analyzer for concentration ranging from 0.5% to 3.0% and temperature of 30, 50 and 70°C. The results show that the increasing in concentration and temperature lead to enhancement in thermal conductivity at range of concentration studied. The maximum enhancement is found to be 22.1% at concentration 3.0% and temperature 70°C. A new equation is proposed based on the experiment data and found to be in good agreement where the average deviation (AD), standard deviation (SD) and maximum deviation (MD) are 1.67%, 1.66% and 5.13%, respectively.

  3. Review of Polymer, Dye-Sensitized, and Hybrid Solar Cells

    Directory of Open Access Journals (Sweden)

    S. N. F. Mohd-Nasir

    2014-01-01

    Full Text Available The combination of inorganic nanoparticles semiconductor, conjugated polymer, and dye-sensitized in a layer of solar cell is now recognized as potential application in developing flexible, large area, and low cost photovoltaic devices. Several conjugated low bandgap polymers, dyes, and underlayer materials based on the previous studies are quoted in this paper, which can provide guidelines in designing low cost photovoltaic solar cells. All of these materials are designed to help harvest more sunlight in a wider range of the solar spectrum besides enhancing the rate of charge transfer in a device structure. This review focuses on developing solid-state dye-synthesized, polymer, and hybrid solar cells.

  4. Hybrids of Solar Sail, Solar Electric, and Solar Thermal Propulsion for Solar-System Exploration

    Science.gov (United States)

    Wilcox, Brian H.

    2012-01-01

    Solar sails have long been known to be an attractive method of propulsion in the inner solar system if the areal density of the overall spacecraft (S/C) could be reduced to approx.10 g/sq m. It has also long been recognized that the figure (precise shape) of useful solar sails needs to be reasonably good, so that the reflected light goes mostly in the desired direction. If one could make large reflective surfaces with reasonable figure at an areal density of approx.10 g/sq m, then several other attractive options emerge. One is to use such sails as solar concentrators for solar-electric propulsion. Current flight solar arrays have a specific output of approx. 100W/kg at 1 Astronomical Unit (AU) from the sun, and near-term advances promise to significantly increase this figure. A S/C with an areal density of 10 g/sq m could accelerate up to 29 km/s per year as a solar sail at 1 AU. Using the same sail as a concentrator at 30 AU, the same spacecraft could have up to approx. 45 W of electric power per kg of total S/C mass available for electric propulsion (EP). With an EP system that is 50% power-efficient, exhausting 10% of the initial S/C mass per year as propellant, the exhaust velocity is approx. 119 km/s and the acceleration is approx. 12 km/s per year. This hybrid thus opens attractive options for missions to the outer solar system, including sample-return missions. If solar-thermal propulsion were perfected, it would offer an attractive intermediate between solar sailing in the inner solar system and solar electric propulsion for the outer solar system. In the example above, both the solar sail and solar electric systems don't have a specific impulse that is near-optimal for the mission. Solar thermal propulsion, with an exhaust velocity of the order of 10 km/s, is better matched to many solar system exploration missions. This paper derives the basic relationships between these three propulsion options and gives examples of missions that might be enabled by

  5. Role of exact exchange in thermally-assisted-occupation density functional theory: A proposal of new hybrid schemes.

    Science.gov (United States)

    Chai, Jeng-Da

    2017-01-28

    We propose hybrid schemes incorporating exact exchange into thermally assisted-occupation-density functional theory (TAO-DFT) [J.-D. Chai, J. Chem. Phys. 136, 154104 (2012)] for an improved description of nonlocal exchange effects. With a few simple modifications, global and range-separated hybrid functionals in Kohn-Sham density functional theory (KS-DFT) can be combined seamlessly with TAO-DFT. In comparison with global hybrid functionals in KS-DFT, the resulting global hybrid functionals in TAO-DFT yield promising performance for systems with strong static correlation effects (e.g., the dissociation of H 2 and N 2 , twisted ethylene, and electronic properties of linear acenes), while maintaining similar performance for systems without strong static correlation effects. Besides, a reasonably accurate description of noncovalent interactions can be efficiently achieved through the inclusion of dispersion corrections in hybrid TAO-DFT. Relative to semilocal density functionals in TAO-DFT, global hybrid functionals in TAO-DFT are generally superior in performance for a wide range of applications, such as thermochemistry, kinetics, reaction energies, and optimized geometries.

  6. ZnO-based nanocrystalline powders with applications in hybrid photovoltaic cells

    Energy Technology Data Exchange (ETDEWEB)

    Damonte, L.C. [Dto. De Fisica, UNLP, IFLP-CCT-CONICET, C.C.67 (1900) La Plata (Argentina); Dto. De Fisica Aplicada, Universidad Politecnica de Valencia, Cami de Vera s/n (46071) Valencia (Spain); Donderis, V. [Dto. De Ingenieria Electrica, Universidad Politecnica de Valencia, Cami de Vera s/n (46071) Valencia (Spain); Ferrari, S.; Meyer, M. [Dto. De Fisica, UNLP, IFLP-CCT-CONICET, C.C.67 (1900) La Plata (Argentina); Orozco, J. [Dto. de Ingenieria Mecanica y Materiales, Universidad Politecnica de Valencia, Cami de Vera s/n (46071) Valencia (Spain); Hernandez-Fenollosa, M.A. [Dto. De Fisica Aplicada, Universidad Politecnica de Valencia, Cami de Vera s/n (46071) Valencia (Spain)

    2010-06-15

    In recent years there has been a growing interest in the development of hybrid photovoltaic cells consisting of new materials, such as devices based on the combination of a wide gap semiconductor and an organic dye (dye-sensitized solar cells, DSSC). In this paper we obtain nano-zinc oxide particles whose optical and electrical properties have been modified by the presence of small amounts of Al or In acting as dopants. The aim of this study is to improve the compatibility of each of the compounds present in the photovoltaic solar cell. The knowledge gained will provide input to guide the processes in the manufacture of hybrid solar cells. (author)

  7. Thermal conductivity prediction of nanoscale phononic crystal slabs using a hybrid lattice dynamics-continuum mechanics technique

    Directory of Open Access Journals (Sweden)

    Charles M. Reinke

    2011-12-01

    Full Text Available Recent work has demonstrated that nanostructuring of a semiconductor material to form a phononic crystal (PnC can significantly reduce its thermal conductivity. In this paper, we present a classical method that combines atomic-level information with the application of Bloch theory at the continuum level for the prediction of the thermal conductivity of finite-thickness PnCs with unit cells sized in the micron scale. Lattice dynamics calculations are done at the bulk material level, and the plane-wave expansion method is implemented at the macrosale PnC unit cell level. The combination of the lattice dynamics-based and continuum mechanics-based dispersion information is then used in the Callaway-Holland model to calculate the thermal transport properties of the PnC. We demonstrate that this hybrid approach provides both accurate and efficient predictions of the thermal conductivity.

  8. Thermal and Mechanical Behavior of Hybrid Polymer Nanocomposite Reinforced with Graphene Nanoplatelets

    Directory of Open Access Journals (Sweden)

    Minh-Tai Le

    2015-08-01

    Full Text Available In the present investigation, we successfully fabricate a hybrid polymer nanocomposite containing epoxy/polyester blend resin and graphene nanoplatelets (GNPs by a novel technique. A high intensity ultrasonicator is used to obtain a homogeneous mixture of epoxy/polyester resin and graphene nanoplatelets. This mixture is then mixed with a hardener using a high-speed mechanical stirrer. The trapped air and reaction volatiles are removed from the mixture using high vacuum. The hot press casting method is used to make the nanocomposite specimens. Tensile tests, dynamic mechanical analysis (DMA and thermogravimetric analysis (TGA are performed on neat, 0.2 wt %, 0.5 wt %, 1 wt %, 1.5 wt % and 2 wt % GNP-reinforced epoxy/polyester blend resin to investigate the reinforcement effect on the thermal and mechanical properties of the nanocomposites. The results of this research indicate that the tensile strength of the novel nanocomposite material increases to 86.8% with the addition of a ratio of graphene nanoplatelets as low as 0.2 wt %. DMA results indicate that the 1 wt % GNP-reinforced epoxy/polyester nanocomposite possesses the highest storage modulus and glass transition temperature (Tg, as compared to neat epoxy/polyester or the other nanocomposite specimens. In addition, TGA results verify thethermal stability of the experimental specimens, regardless of the weight percentage of GNPs.

  9. Thermal and Mechanical Behavior of Hybrid Polymer Nanocomposite Reinforced with Graphene Nanoplatelets

    Science.gov (United States)

    Le, Minh-Tai; Huang, Shyh-Chour

    2015-01-01

    In the present investigation, we successfully fabricate a hybrid polymer nanocomposite containing epoxy/polyester blend resin and graphene nanoplatelets (GNPs) by a novel technique. A high intensity ultrasonicator is used to obtain a homogeneous mixture of epoxy/polyester resin and graphene nanoplatelets. This mixture is then mixed with a hardener using a high-speed mechanical stirrer. The trapped air and reaction volatiles are removed from the mixture using high vacuum. The hot press casting method is used to make the nanocomposite specimens. Tensile tests, dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) are performed on neat, 0.2 wt %, 0.5 wt %, 1 wt %, 1.5 wt % and 2 wt % GNP-reinforced epoxy/polyester blend resin to investigate the reinforcement effect on the thermal and mechanical properties of the nanocomposites. The results of this research indicate that the tensile strength of the novel nanocomposite material increases to 86.8% with the addition of a ratio of graphene nanoplatelets as low as 0.2 wt %. DMA results indicate that the 1 wt % GNP-reinforced epoxy/polyester nanocomposite possesses the highest storage modulus and glass transition temperature (Tg), as compared to neat epoxy/polyester or the other nanocomposite specimens. In addition, TGA results verify thethermal stability of the experimental specimens, regardless of the weight percentage of GNPs. PMID:28793521

  10. Investigation of the Mechanical Properties of Hybrid Carbon-Hemp Laminated Composites Used as Thermal Insulation for Different Industrial Applications

    Directory of Open Access Journals (Sweden)

    M. L. Scutaru

    2014-04-01

    Full Text Available Carbon-hemp composite laminate provides good thermal properties. For this reason this type of material is presently being used for various applications like insulator for airplanes, spaceships, nuclear reactors, and so forth. Unfortunately their mechanical properties are less studied. These characteristics are very important since they should be guaranteed also for important mechanical stress in addition to the thermal one. The present paper presents a study regarding the impact testing of some hybrid composite laminate panels based on polyester resin reinforced with both carbon and hemp fabric. The effects of different impact speeds on the mechanical behavior of these panels have been analyzed. The paper lays stress on the characterization of this hybrid composite laminate regarding the impact behavior of these panels by dropping a weight with low velocity.

  11. Novel thermal management system using boiling cooling for high-powered lithium-ion battery packs for hybrid electric vehicles

    Science.gov (United States)

    Al-Zareer, Maan; Dincer, Ibrahim; Rosen, Marc A.

    2017-09-01

    A thermal management system is necessary to control the operating temperature of the lithium ion batteries in battery packs for electrical and hybrid electrical vehicles. This paper proposes a new battery thermal management system based on one type of phase change material for the battery packs in hybrid electrical vehicles and develops a three dimensional electrochemical thermal model. The temperature distributions of the batteries are investigated under various operating conditions for comparative evaluations. The proposed system boils liquid propane to remove the heat generated by the batteries, and the propane vapor is used to cool the part of the battery that is not covered with liquid propane. The effect on the thermal behavior of the battery pack of the height of the liquid propane inside the battery pack, relative to the height of the battery, is analyzed. The results show that the propane based thermal management system provides good cooling control of the temperature of the batteries under high and continuous charge and discharge cycles at 7.5C.

  12. Assessing the potential of hybrid fossil–solar thermal plants for energy policy making: Brayton cycles

    International Nuclear Information System (INIS)

    Bernardos, Eva; López, Ignacio; Rodríguez, Javier; Abánades, Alberto

    2013-01-01

    This paper proposes a first study in-depth of solar–fossil hybridization from a general perspective. It develops a set of useful parameters for analyzing and comparing hybrid plants, it studies the case of hybridizing Brayton cycles with current solar technologies and shows a tentative extrapolation of the results to integrated combined cycle systems (ISCSS). In particular, three points have been analyzed: the technical requirements for solar technologies to be hybridized with Brayton cycles, the temperatures and pressures at which hybridization would produce maximum power per unit of fossil fuel, and their mapping to current solar technologies and Brayton cycles. Major conclusions are that a hybrid plant works in optimum conditions which are not equal to those of the solar or power blocks considered independently, and that hybridizing at the Brayton cycle of a combined cycle could be energetically advantageous. -- Highlights: •We model a generic solar–fossil hybrid Brayton cycle. •We calculate the operating conditions for maximum ratio power/fuel consumption. •Best hybrid plant conditions are not the same as solar or power blocks separately. •We study potential for hybridization with current solar technologies. •Hybridization at the Brayton in a combined cycle may achieve high power/fuel ratio

  13. Optimizing Thermal-Elastic Properties of C/C–SiC Composites Using a Hybrid Approach and PSO Algorithm

    Science.gov (United States)

    Xu, Yingjie; Gao, Tian

    2016-01-01

    Carbon fiber-reinforced multi-layered pyrocarbon–silicon carbide matrix (C/C–SiC) composites are widely used in aerospace structures. The complicated spatial architecture and material heterogeneity of C/C–SiC composites constitute the challenge for tailoring their properties. Thus, discovering the intrinsic relations between the properties and the microstructures and sequentially optimizing the microstructures to obtain composites with the best performances becomes the key for practical applications. The objective of this work is to optimize the thermal-elastic properties of unidirectional C/C–SiC composites by controlling the multi-layered matrix thicknesses. A hybrid approach based on micromechanical modeling and back propagation (BP) neural network is proposed to predict the thermal-elastic properties of composites. Then, a particle swarm optimization (PSO) algorithm is interfaced with this hybrid model to achieve the optimal design for minimizing the coefficient of thermal expansion (CTE) of composites with the constraint of elastic modulus. Numerical examples demonstrate the effectiveness of the proposed hybrid model and optimization method. PMID:28773343

  14. On The Physico-Mechanics, Thermal and Microstructure Properties of Hybrid Composite Epoxy-Geopolymer for Geothermal Pipe Application

    Directory of Open Access Journals (Sweden)

    Firawati Ira

    2017-01-01

    Full Text Available The objective of this study is to determine the effect of epoxy resin on the physico-mechanics, thermal and microstructure properties of geopolymers hybrid composites for geothermal pipe application. Hybrid composite epoxy-geopolymers pipes were produced through alkali activation method of class-C fly ash and epoxy resin. The mass of epoxy-resin was varied relative to the mass of fly ash namely 0% (SPG01, 5% (SPG02, 10% (SPG03, 15% (SPG04, and 20% (SPG05. The resulting materials were stored in open air for 28 days before conducting any measurements. The densities of the product composites were measured before and after the samples immersed in boiling water for 3 hours. The mechanical strength of the resulting geothermal pipes was measured by using splitting tensile measurement. The thermal properties of the pipes were measured by means of thermal conductivity measurement, differential scanning calorimetry (DSC and fire resistance measurements. The chemical resistance was measured by immersing the samples into 1M H2SO4 solution for 4 days. The microstructure properties of the resulting materials were examined by using x-ray diffraction (XRD and Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS. The results of this study showed that hybrid composite epoxy-geopolymers SPG02 and SPG03 are suitable to be applied as geothermal pipes.

  15. Study of the defects related to oxygen in Czochralski silicon destined to photovoltaic solar cells - Influence of isovalent impurities

    International Nuclear Information System (INIS)

    Tanay, Florent

    2013-01-01

    This study aims at understanding the effects of two main defects related to oxygen, the boron-oxygen complexes (responsible for light-induced degradation of the carrier lifetime) and the thermal donors (among other things, responsible for variations of the conductivity), on the electric and photovoltaic properties of silicon. More precisely, the interactions of isovalent impurities, known for modifying the oxygen spatial distribution, with these defects were studied. Two experimental protocols were first developed to evaluate the light-induced degradation of the carrier lifetime in iron-rich silicon. Then, the introduction in silicon of germanium and tin in high quantity were shown not to significantly influence the conversion efficiency of the cells. However, contrary to recent studies from the literature, no reduction due to germanium co-doping or to tin co-doping of the light-induced degradation of the photovoltaic performances was observed. However carbon was shown to lead to a slowdown of the degradation due to boron-oxygen complexes. Moreover contrary to tin which has no influence on the thermal donor generation, germanium slows down their formation. An empirical expression has been proposed to take into account this effect for a large range of germanium concentrations. Eventually in highly doped and compensated silicon, the thermal donor generation is identical as in conventional silicon, which experimentally confirms that the thermal donor formation is limited by the electron density. (author) [fr

  16. Electrically and Thermally Conductive Low Density Polyethylene-Based Nanocomposites Reinforced by MWCNT or Hybrid MWCNT/Graphene Nanoplatelets with Improved Thermo-Oxidative Stability

    OpenAIRE

    Sandra Paszkiewicz; Anna Szymczyk; Daria Pawlikowska; Jan Subocz; Marek Zenker; Roman Masztak

    2018-01-01

    In this paper, the electrical and thermal conductivity and morphological behavior of low density polyethylene (LDPE)/multi-walled carbon nanotubes (MWCNTs) + graphene nanoplatelets (GNPs) hybrid nanocomposites (HNCs) have been studied. The distribution of MWCNTs and the hybrid of MWCNTs/GNPs within the polymer matrix has been investigated with scanning electron microscopy (SEM). The results showed that the thermal and electrical conductivity of the LDPE-based nanocomposites increased along wi...

  17. Hybrid model predictive control of a residential HVAC system with on-site thermal energy generation and storage

    International Nuclear Information System (INIS)

    Fiorentini, Massimo; Wall, Josh; Ma, Zhenjun; Braslavsky, Julio H.; Cooper, Paul

    2017-01-01

    Highlights: • A comprehensive approach to managing thermal energy in residential buildings. • Solar-assisted HVAC system with on-site energy generation and storage. • Mixed logic-dynamical building model identified using experimental data. • Design and implementation of a logic-dynamical model predictive control strategy. • MPC applied to the Net-Zero Energy house winner of the Solar Decathlon China 2013. - Abstract: This paper describes the development, implementation and experimental investigation of a Hybrid Model Predictive Control (HMPC) strategy to control solar-assisted heating, ventilation and air-conditioning (HVAC) systems with on-site thermal energy generation and storage. A comprehensive approach to the thermal energy management of a residential building is presented to optimise the scheduling of the available thermal energy resources to meet a comfort objective. The system has a hybrid nature with both continuous variables and discrete, logic-driven operating modes. The proposed control strategy is organized in two hierarchical levels. At the high-level, an HMPC controller with a 24-h prediction horizon and a 1-h control step is used to select the operating mode of the HVAC system. At the low-level, each operating mode is optimised using a 1-h rolling prediction horizon with a 5-min control step. The proposed control strategy has been practically implemented on the Building Management and Control System (BMCS) of a Net Zero-Energy Solar Decathlon house. This house features a sophisticated HVAC system comprising of an air-based photovoltaic thermal (PVT) collector and a phase change material (PCM) thermal storage integrated with the air-handling unit (AHU) of a ducted reverse-cycle heat pump system. The simulation and experimental results demonstrated the high performance achievable using an HMPC approach to optimising complex multimode HVAC systems in residential buildings, illustrating efficient selection of the appropriate operating modes

  18. Efficiency maximization and performance evaluation of hybrid dual channel semitransparent photovoltaic thermal module using fuzzyfied genetic algorithm

    International Nuclear Information System (INIS)

    Singh, Sonveer; Agrawal, Sanjay

    2016-01-01

    Highlights: • Thermal modeling of novel dual channel semitransparent photovoltaic thermal hybrid module. • Efficiency maximization and performance evaluation of dual channel photovoltaic thermal module. • Annual performance has been evaluated for Srinagar, Jodhpur, Bangalore and New Delhi (India). • There are improvements in results for optimized system as compared to un-optimized system. - Abstract: The work has been carried out in two steps; firstly the parameters of hybrid dual channel semitransparent photovoltaic thermal module has been optimized using a fuzzyfied genetic algorithm. During the course of optimization, overall exergy efficiency is considered as an objective function and different design parameters of the proposed module have been optimized. Fuzzy controller is used to improve the performance of genetic algorithms and the approach is called as a fuzzyfied genetic algorithm. In the second step, the performance of the module has been analyzed for four cities of India such as Srinagar, Bangalore, Jodhpur and New Delhi. The performance of the module has been evaluated for daytime 08:00 AM to 05:00 PM and annually from January to December. It is to be noted that, an average improvement occurs in electrical efficiency of the optimized module, simultaneously there is also a reduction in solar cell temperature as compared to un-optimized module.

  19. Proposed Framework of Hybrid Photovoltaic Thermal Systems to Ecotourism in Malaysia

    Directory of Open Access Journals (Sweden)

    Hajibeigy Mohammad Taghi

    2018-01-01

    Full Text Available Ecotourism is widely recognized for its positive impacts to the environment. Ecotourism is defined as nature-based tourist experiences, which visitors travel to regions for the purpose of appreciating their natural beauty, relaxation and being harmonious with Mother Nature. Ecotourism probably had its foundations in the ethics of conservation, which can help maintain what’s left of nature and fosters environmental education. Employing the sustainable energy, paying more attention to the natural resources and developing existing natural resources will have a direct impact to healthier sustainable environment for the inhabitant. If not all, most of the ecotourism sites are located in the remote area in which to utilize electrical energy from the normal grid is difficult or very costly. On the irony, utilizing the conventional non-renewable energy have negative effect and ruins the ecotourism sites. Therefore, utilizing Hybrid Photovoltaic Thermal (PVT systems is a fit alternative energy source to serve the limited energy demands of ecotourists sites. The amount of the energy production depends on the visitors’ capacity of the site. Since the rural area enjoys the cheap and large field, it is easier to plan and assemble the PVT systems to suffice the needed energy. In this research the sustainability of local environment along with the sustainable usage of energy were considered. This paper presents the sustainable energy usage of tourism in Malaysia and aims to address the impact of sustainable and non-sustainable on the rural area of ecotourism. This paper also addresses some of the emission, carbon reduction and climate change issues that the world is expected to meet soon.

  20. Thermally fabricated MoS{sub 2}-graphene hybrids as high performance anode in lithium ion battery

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, S.K., E-mail: sunil111954@yahoo.co.uk [Department of Chemistry, Indian Institute of Technology, Kharagpur, 721302 (India); Kartick, B. [Department of Chemistry, Indian Institute of Technology, Kharagpur, 721302 (India); Choudhury, S. [Department of Nanostructured Materials, Leibniz-Institut für Polymerforschung Dresden e.V. (IPF Dresden), Hohe Strasse 6, 01069, Dresden (Germany); Stamm, M. [Department of Nanostructured Materials, Leibniz-Institut für Polymerforschung Dresden e.V. (IPF Dresden), Hohe Strasse 6, 01069, Dresden (Germany); Technische Universität Dresden, Physical Chemistry of Polymer Materials, 01062, Dresden (Germany)

    2016-11-01

    MoS{sub 2}-reduced graphene oxide (MoS{sub 2}-rGO: where rGO = 0, 1, 3, 5, 7 and 10 wt%) hybrids have been fabricated using (NH{sub 4}){sub 2}MoS{sub 4} and graphite oxide as single source precursors of MoS{sub 2} and thermally exfoliated reduced graphene oxide respectively. These individual precursors were initially subjected to grinding for 30 min followed by heating at 1200 °C for 15 min and characterized. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM) confirmed co-dispersion of MoS{sub 2} on thermally exfoliated graphite oxide. Electrochemical studies of these hybrids as anode materials showed that MoS{sub 2}-rGO (7 wt%) exhibited superior reversible capacity, cycling stability, enhanced rate performance (780 mAhg{sup −1}) and rate capability (880 mAhg{sup −1}) over pristine MoS{sub 2} and other hybrids. - Highlights: • MoS{sub 2}-graphene hybrids are synthesized by high temperature from individual precursors. • These hybrids have been used as anode material in LIB. • MoS{sub 2}-graphene (7 wt%) exhibited superior reversible capacity and cycling stability. • It showed high rate performance (780 mA h g{sup −1}) and rate capability (880 mA h g{sup −1}). • Enhanced performance at lower graphene makes it most attractive anode material in LIB.

  1. A novel syngas-fired hybrid heating source for solar-thermal applications: Energy and exergy analysis

    International Nuclear Information System (INIS)

    Pramanik, Santanu; Ravikrishna, R.V.

    2016-01-01

    Highlights: • Biomass-derived syngas as a hybrid energy source for solar thermal power plants. • A novel combustor concept using rich-catalytic and MILD combustion technologies. • Hybrid energy source for a solar-driven supercritical CO 2 -based Brayton cycle. • Comprehensive energetic and exergetic analysis of the combined system. - Abstract: A hybrid heating source using biomass-derived syngas is proposed to enable continuous operation of standalone solar thermal power generation plants. A novel, two-stage, low temperature combustion system is proposed that has the potential to provide stable combustion of syngas with near-zero NO x emissions. The hybrid heating system consists of a downdraft gasifier, a two-stage combustion system, and other auxiliaries. When integrated with a solar cycle, the entire system can be referred to as the integrated gasification solar combined cycle (IGSCC). The supercritical CO 2 Brayton cycle (SCO 2 ) is selected for the solar cycle due to its high efficiency. The thermodynamic performance evaluation of the individual unit and the combined system has been conducted from both energy and exergy considerations. The effect of parameters such as gasification temperature, biomass moisture content, equivalence ratio, and pressure ratio is studied. The efficiency of the IGSCC exhibited a non-monotonic behavior. A maximum thermal efficiency of 36.5% was achieved at an overall equivalence ratio of 0.22 and pressure ratio of 2.75 when the gasifier was operating at T g = 1073 K with biomass containing 20% moisture. The efficiency increased to 40.8% when dry biomass was gasified at a temperature of 973 K. The exergy analysis revealed that the maximum exergy destruction occurred in the gasification system, followed by the combustion system, SCO 2 cycle, and regenerator. The exergy analysis also showed that 8.72% of the total exergy is lost in the exhaust; however, this can be utilized for drying of the biomass.

  2. Thermal Analysis of Hybrid Thermal Control System and Experimental Investigation of Flow Boiling in Micro-channel Heat Exchangers

    Science.gov (United States)

    Lee, Seunghyun

    Future manned space endeavors will require a new class of vehicles, capable of conducting different types of missions and enduring varying gravitational and temperature environments. Thermal management will play a vital role in these new vehicles, and is complicated by the need to tackle both low and high heat sink temperatures. The present study assesses the feasibility of hybrid thermal control system by thermodynamic analysis and investigates the heat transfer mechanisms in two large micro-channel heat exchangers in vapor compression mode and two-phase mode. Unlike prior published two-phase micro-channel studies that concern mostly miniature heat sinks, this study addresses transport characteristics of a heat sink containing large length-to-diameter ratio, up to 609.6 to 1,micro-channels. In the thermodynamic analysis, four different operational modes are considered: single-phase, two-phase, basic heat pump and heat pump with liquid-side, suction-side heat exchanger. A thermodynamic trade study is conducted for six different working fluids to assess important performance parameters including mass flow rate of the working fluid, maximum pressure, radiator area, compressor/pump work, and coefficient of performance (COP). R134a is determined to be most suitable based on its ability to provide a balanced compromise between reducing flow rate and maintaining low system pressure, and a moderate coefficient of performance (COP); this fluid is also both nontoxic and nonflammable, and features zero ozone depletion potential (ODP) and low global warming potential (GWP). It is shown how specific mission stages dictate which mode of operation is most suitable, and this information is used to size the radiator for the H-TCS. The experimental flow boiling investigation consists of exploring the steady-state and the transient two-phase heat transfer characteristics of two large micro-channel heat exchangers that serve as evaporators in the vapor compression loop using R134a as

  3. On the modelling of linear-assisted DC-DC voltage regulators for photovoltaic solar energy systems

    Science.gov (United States)

    Martínez-García, Herminio; García-Vílchez, Encarna

    2017-11-01

    This paper shows the modelling of linear-assisted or hybrid (linear & switching) DC/DC voltage regulators. In this kind of regulators, an auxiliary linear regulator is used, which objective is to cancel the ripple at the output voltage and provide fast responses for load variations. On the other hand, a switching DC/DC converter, connected in parallel with the linear regulator, allows to supply almost the whole output current demanded by the load. The objective of this topology is to take advantage of the suitable regulation characteristics that series linear voltage regulators have, but almost achieving the high efficiency that switching DC/DC converters provide. Linear-assisted DC/DC regulators are feedback systems with potential instability. Therefore, their modelling is mandatory in order to obtain design guidelines and assure stability of the implemented power supply system.

  4. High thermal efficiency and low emission performance of a methanol reformed gas fueled engine for hybrid electric vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Yamane, K.; Nakajima, Y.; Shudo, T.; Hiruma, M. [Musahi Inst. of Tech., Tokyo (Japan); Komatsu, H.; Takagi, Y. [Nissan Motor Co., Ltd., Yokosuka (Japan)

    2000-07-01

    An internal combustion engine (ICE) operation was carried out experimentally by using the mixture of air and fuel simulating the reformed gas as the fuel. It has been found that the engine can expectedly attain ultra-low emission and high thermal efficiency, namely 35% brake thermal efficiency in the basis of the low heat value of the theoretically reformed gas or 42% in the basis of the low heat value of methanol. By using the result for the estimation of the total thermal efficiency at the end of the motor output shaft of a hybrid electric vehicle, it has been found that the total thermal efficiency of the reformed gas engine system is 34% in case of a 120% energy increment and 33% in case of a 116% energy increment with a little higher NOx emission of 60 ppm while the counterpart of the fuel cell system is 34%. When the emission level for EZEV is required, the total thermal efficiency falls to 32% in case of a 120% energy increment and 31% in case of a 116% energy increment. From the points of the reliability proved by the long history, higher specific power and low cost, the internal combustion engine system with the thermal efficiency almost equal to that of the fuel cell (FC) system is further more practical when methanol is used as the fuel. (orig.)

  5. Analysis of the mechanical and thermal properties of jute and glass fiber as reinforcement epoxy hybrid composites

    Energy Technology Data Exchange (ETDEWEB)

    Braga, R.A., E-mail: roney.braga@fiat.com.br [FIAT Automóveis S.A., Teardown, CEP 32530-000 Betim, MG (Brazil); Magalhaes, P.A.A., E-mail: pamerico@pucminas.br [PUC—MINAS, Instituto Politécnico, CEP 30535-610 Belo Horizonte, MG (Brazil)

    2015-11-01

    This work describes the study to investigate and compare the mechanical and thermal properties of raw jute and glass fiber reinforced epoxy hybrid composites. To improve the mechanical properties, jute fiber was hybridized with glass fiber. Epoxy resin, jute and glass fibers were laminated in three weight ratios (69/31/0, 68/25/7 and 64/18/19) respectively to form composites. The tensile, flexural, impact, density, thermal and water absorption tests were carried out using hybrid composite samples. This study shows that the addition of jute fiber and glass fiber in epoxy, increases the density, the impact energy, the tensile strength and the flexural strength, but decreases the loss mass in function of temperature and the water absorption. Morphological analysis was carried out to observe fracture behavior and fiber pull-out of the samples using scanning electron microscope. - Highlights: • The work is the study of the mechanical of raw jute and glass fiber with epoxy resin. • The mechanical properties increased with more proportions of glass fibers. • The density of E69-J31-V0 was the lower. • The flexural strength did not have a significant increase. • The water absorption of E69-J31-V0 was the best.

  6. Thermodynamic analyses of solar thermal gasification of coal for hybrid solar-fossil power and fuel production

    International Nuclear Information System (INIS)

    Ng, Yi Cheng; Lipiński, Wojciech

    2012-01-01

    Thermodynamic analyses are performed for solar thermal steam and dry gasification of coal. The selected types of coal are anthracite, bituminous, lignite and peat. Two model conversion paths are considered for each combination of the gasifying agent and the coal type: production of the synthesis gas with its subsequent use in a combined cycle power plant to generate power, and production of the synthesis gas with its subsequent use to produce gasoline via the Fischer–Tropsch synthesis. Replacement of a coal-fired 35% efficient Rankine cycle power plant and a combustion-based integrated gasification combined cycle power plant by a solar-based integrated gasification combined cycle power plant leads to the reduction in specific carbon dioxide emissions by at least 47% and 27%, respectively. Replacement of a conventional gasoline production process via coal gasification and a subsequent Fischer–Tropsch synthesis with gasoline production via solar thermal coal gasification with a subsequent Fischer–Tropsch synthesis leads to the reduction in specific carbon dioxide emissions by at least 39%. -- Highlights: ► Thermodynamic analyses for steam and dry gasification of coal are presented. ► Hybrid solar-fossil paths to power and fuels are compared to those using only combustion. ► Hybrid power production can reduce specific CO 2 emissions by more than 27%. ► Hybrid fuel production can reduce specific CO 2 emissions by more than 39%.

  7. Hybrid van der Waals SnO/MoS2 Heterojunctions for Thermal and Optical Sensing Applications

    KAUST Repository

    Wang, Zhenwei

    2017-11-10

    Emerging van der Waals heterojunctions (vdWH) containing 2D materials have shown exciting functionalities that surpass those of traditional devices based on bulk materials. In this Communication, a report on the properties of a 2D sulfide/oxide hybrid vdWH based on n-type molybdenum disulfide (MoS2) and p-type tin monoxide (SnO) is presented, with promising rectification, thermal-sensing, and photosensing performance. Specifically, the hybrid SnO/MoS2 vdWH shows static rectification ratio of 2 × 102 with ideality factor of 2.3, and can operate at 100 Hz with good stability. The vdWH shows good temperature stability with reversible and reproducible current levels up to 110 °C, indicating its potential for thermal sensing applications. The sensitivity of current variation is calculated to be 0.0144 dec °C−1. Finally, maximum responsivity of 8.17 mA W−1 and external quantum efficiency of 2.14% have been achieved in photovoltaic measurements. The results suggest that MoS2–SnO hybrid vdWH are promising for various sensing applications.

  8. Characteristic on photovoltaic/thermal hybrid collector. Evaluation of excergetic theory; Taiyoko netsu hybrid collector no tokusei. Exergy ni yoru hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Iwawaki, H; Morita, Y; Fujisawa, T; Tani, T [Science University of Tokyo, Tokyo (Japan)

    1997-11-25

    Described herein are characteristics of photovoltaic (PV)/thermal hybrid collectors (PV/Ts), in which a PV module is combined with a plate-shape solar heat collector to simultaneously produce electric power and heat. Their efficiency is assessed by exergy. The test results indicate that the PV/T system gives a 1.07 times higher exergy than the PV system, 86.3 versus 80.7kWh. In terms of energy, the optimum values (OVs) are 5, 44 and 37% lower than the measuring values (MVs) for electrical energy, thermal energy and total exergy. In terms of exergy, on the other hand, OV is 5% lower than MV for electrical energy, but 893 times higher for thermal energy and 1.26 times higher for total exergy. As a result, the exergy level is 26% higher than that of a system which generates power as the main product and heat as the auxiliary product. 3 refs., 6 figs., 5 tabs.

  9. Facile and low energy consumption synthesis of microencapsulated phase change materials with hybrid shell for thermal energy storage

    Science.gov (United States)

    Wang, Hao; Zhao, Liang; Chen, Lijie; Song, Guolin; Tang, Guoyi

    2017-12-01

    We designed a photocurable pickering emulsion polymerization to create microencapsulated phase change materials (MicroPCM) with polymer-silica hybrid shell. The emulsion was stabilized by modified SiO2 particles without any surfactant or dispersant. The polymerization process can be carried out at ambient temperature only for 5 min ultraviolet radiation, which is a low-energy procedure. The resultant capsules were shown a good core-shell structure and uniform in size. The surface of the microcapsules was covered by SiO2 particles. According to the DSC and TGA examinations, the microcapsules has good thermal energy storage-release performance, enhanced thermal reliability and thermal stability. When ratio of MMA/n-octadecane was 1.5/1.5. The encapsulation efficiency of the microcapsules reached 62.55%, accompanied with 122.31 J/g melting enthalpy. The work is virtually applicable to the construction of a wide variety of organic-inorganic hybrid shell MicroPCM. Furthermore, with the application of this method, exciting opportunities may arise for realizing rapid, continuous and large-scale industrial preparation of MicroPCM.

  10. Photovoltaic solar panels of crystalline silicon: characterization and separation; Paineis solares fotovoltaicos de silicio cristalino: caracterizacao e separacao

    Energy Technology Data Exchange (ETDEWEB)

    Diasa, P.R.; Benevita, M.G.; Veita, H.M., E-mail: pablo.dias@ufrgs.br [Universidade Federal do Rio Grande do Sul (LACOR/UFRGS), Porto Alegre, RS (Brazil). Laboratorio de Corrosao, Protecao e Reciclagem de Materiais

    2014-07-01

    The search for alternative power generation sources has been intensified in recent years. One of these alternatives is solar energy, since it is a virtually inexhaustible source and generates relatively small environmental impact compared to other traditional generation sources. The collection of solar energy and its conversion into thermal or electrical energy is only possible through the use of photovoltaic panels. These panels have a limited lifespan and will eventually be replaced by new ones. Thus, in the near future, large amounts of solar modules can be discarded as waste electronics. In order to retrieve important raw materials, reducing production costs and environmental impacts, recycling such materials is important. In this paper, photovoltaic module components were characterized through visual inspection, FRX, EDS and AAS. The glass was identified as ordinary glass (soda-lime glass), which allows reuse without any previous treatment and the metallic filaments were identified as tin- lead coated copper. (author)

  11. Recent developments in thermally-driven seawater desalination: Energy efficiency improvement by hybridization of the MED and AD cycles

    KAUST Repository

    Ng, Kim Choon

    2015-01-01

    The energy, water and environment nexus is a crucial factor when considering the future development of desalination plants or industry in the water-stressed economies. New generation of desalination processes or plants has to meet the stringent environment discharge requirements and yet the industry remains highly energy efficient and sustainable when producing good potable water. Water sources, either brackish or seawater, have become more contaminated as feed while the demand for desalination capacities increase around the world. One immediate solution for energy efficiency improvement comes from the hybridization of the proven desalination processes to the newer processes of desalination: For example, the integration of the available thermally-driven to adsorption desalination (AD) cycles where significant thermodynamic synergy can be attained when cycles are combined. For these hybrid cycles, a quantum improvement in energy efficiency as well as in increase in water production can be expected. The advent of MED with AD cycles, or simply called the MEDAD cycles, is one such example where seawater desalination can be pursued and operated in cogeneration with the electricity production plants: The hybrid desalination cycles utilize only the low exergy bled-steam at low temperatures, complemented with waste exhaust or renewable solar thermal heat at temperatures between 60 and 80. °C. In this paper, the authors have reported their pioneered research on aspects of AD and related hybrid MEDAD cycles, both at theoretical models and experimental pilots. Using the cogeneration of electricity and desalination concept, the authors examined the cost apportionment of fuel cost by the quality or exergy of working steam for such cogeneration configurations.

  12. The combined hybrid system: A symbiotic thermal reactor/fast reactor system for power generation and radioactive waste toxicity reduction

    International Nuclear Information System (INIS)

    Hollaway, W.R.

    1991-08-01

    If there is to be a next generation of nuclear power in the United States, then the four fundamental obstacles confronting nuclear power technology must be overcome: safety, cost, waste management, and proliferation resistance. The Combined Hybrid System (CHS) is proposed as a possible solution to the problems preventing a vigorous resurgence of nuclear power. The CHS combines Thermal Reactors (for operability, safety, and cost) and Integral Fast Reactors (for waste treatment and actinide burning) in a symbiotic large scale system. The CHS addresses the safety and cost issues through the use of advanced reactor designs, the waste management issue through the use of actinide burning, and the proliferation resistance issue through the use of an integral fuel cycle with co-located components. There are nine major components in the Combined Hybrid System linked by nineteen nuclear material mass flow streams. A computer code, CHASM, is used to analyze the mass flow rates CHS, and the reactor support ratio (the ratio of thermal/fast reactors), IFR of the system. The primary advantages of the CHS are its essentially actinide-free high-level radioactive waste, plus improved reactor safety, uranium utilization, and widening of the option base. The primary disadvantages of the CHS are the large capacity of IFRs required (approximately one MW e IFR capacity for every three MW e Thermal Reactor) and the novel radioactive waste streams produced by the CHS. The capability of the IFR to burn pure transuranic fuel, a primary assumption of this study, has yet to be proven. The Combined Hybrid System represents an attractive option for future nuclear power development; that disposal of the essentially actinide-free radioactive waste produced by the CHS provides an excellent alternative to the disposal of intact actinide-bearing Light Water Reactor spent fuel (reducing the toxicity based lifetime of the waste from roughly 360,000 years to about 510 years)

  13. Investigating the potential of a novel low-energy house concept with hybrid adaptable thermal storage

    NARCIS (Netherlands)

    Hoes, P.; Trcka, M.; Hensen, J.L.M.; Hoekstra Bonnema, B.

    2010-01-01

    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

  14. Investigating the potential of a novel low-energy house concept with hybrid adaptable thermal storage

    NARCIS (Netherlands)

    Hoes, P.; Trcka, M.; Hensen, J.L.M.; Hoekstra Bonnema, B.

    2011-01-01

    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

  15. MODVOLC2: A Hybrid Time Series Analysis for Detecting Thermal Anomalies Applied to Thermal Infrared Satellite Data

    Science.gov (United States)

    Koeppen, W. C.; Wright, R.; Pilger, E.

    2009-12-01

    We developed and tested a new, automated algorithm, MODVOLC2, which analyzes thermal infrared satellite time series data to detect and quantify the excess energy radiated from thermal anomalies such as active volcanoes, fires, and gas flares. MODVOLC2 combines two previously developed algorithms, a simple point operation algorithm (MODVOLC) and a more complex time series analysis (Robust AVHRR Techniques, or RAT) to overcome the limitations of using each approach alone. MODVOLC2 has four main steps: (1) it uses the original MODVOLC algorithm to process the satellite data on a pixel-by-pixel basis and remove thermal outliers, (2) it uses the remaining data to calculate reference and variability images for each calendar month, (3) it compares the original satellite data and any newly acquired data to the reference images normalized by their variability, and it detects pixels that fall outside the envelope of normal thermal behavior, (4) it adds any pixels detected by MODVOLC to those detected in the time series analysis. Using test sites at Anatahan and Kilauea volcanoes, we show that MODVOLC2 was able to detect ~15% more thermal anomalies than using MODVOLC alone, with very few, if any, known false detections. Using gas flares from the Cantarell oil field in the Gulf of Mexico, we show that MODVOLC2 provided results that were unattainable using a time series-only approach. Some thermal anomalies (e.g., Cantarell oil field flares) are so persistent that an additional, semi-automated 12-µm correction must be applied in order to correctly estimate both the number of anomalies and the total excess radiance being emitted by them. Although all available data should be included to make the best possible reference and variability images necessary for the MODVOLC2, we estimate that at least 80 images per calendar month are required to generate relatively good statistics from which to run MODVOLC2, a condition now globally met by a decade of MODIS observations. We also found

  16. Kinetics of Waterborne Alkyd/Acrylic Hybrid Resin Free Radical Polymerization by Two Systems of Redox and Thermal Initiators

    OpenAIRE

    shirin Madadi; ali akbar Yousefi; elham Keshmirizadeh

    2012-01-01

    Kinetics of radical polymerizations of waterborne alkyd/acrylic hybrid resin via batch mini-emulsion technique was studied using redox initiators (TBHP/Fe2+/EDTA/AsAc  and  TBHP/Fe2+/EDTA/SFS) at relatively low temperatures and thermal initiators (BPO, KPS and AIBN) at higher temperatures to seek the most suitable initiator system. At the end of all reactions the unreacted monomer content was reduced using post-polymerization technique; consequently, leading to increased monomer conversion an...

  17. Microstructural, mechanical, and thermal characteristics of recycled cellulose fiber-halloysite-epoxy hybrid nanocomposites

    KAUST Repository

    Alamri, H.; Low, I. M.

    2012-01-01

    Epoxy hybrid-nanocomposites reinforced with recycled cellulose fibers (RCF) and halloysite nanotubes (HNTs) have been fabricated and investigated. The dispersion of HNTs was studied by synchrotron radiation diffraction (SRD) and transmission

  18. Thermal safety analysis for pebble bed blanket fusion-fission hybrid reactor

    International Nuclear Information System (INIS)

    Wei Renjie

    1998-01-01

    Pebble bed blanket hybrid reactor may have more advantages than slab element blanket hybrid reactor in nuclear fuel production and nuclear safety. The thermo-hydraulic calculations of the blanket in the Tokamak helium cooling pebble bed blanket fusion-fission hybrid reactor developed in China are carried out using the Code THERMIX and auxiliary code. In the calculations different fuel pebble material and steady state, depressurization and total loss of flow accident conditions are included. The results demonstrate that the conceptual design of the Tokamak helium cooling pebble bed blanket fusion-fission hybrid reactor with dump tank is feasible and safe enough only if the suitable fuel pebble material is selected and the suitable control system and protection system are established. Some recommendations for due conceptual design are also presented

  19. DESIGN AND THERMAL PERFORMANCE OF THE SOLAR BIOMASS HYBRID DRYER FOR CASHEW DRYING

    Directory of Open Access Journals (Sweden)

    Saravanan Dhanuskodi

    2014-12-01

    Full Text Available Drying of Cashew nut to remove testa is one of the most energy-intensive processes of cashew nut process industry. For this reason a hybrid dryer consisting of a solar flat plate collector, a biomass heater and a drying chamber is designed and fabricated. 40 kg of Cashew nut with initial moisture of 9 % is used in the experiment. The performance test of the dryer is carried out in two modes of operation: hybrid-forced convection and hybrid-natural convection. Drying time and drying efficiency during these two modes of operation are estimated and compared with the sun drying. The system is capable of attaining drying temperature between 50º and 70ºC. In the hybrid forced drying, the required moisture content of 3% is achieved within 7 hours and the average system efficiency is estimated as 5.08%. In the hybrid natural drying, the required moisture content is obtained in 9 hours and the average system efficiency is 3.17%. The fuel consumption during the drying process is 0.5 kg/hr and 0.75 kg/hr for forced mode and natural mode, respectively. The drying process in the hybrid forced mode of operation is twice faster than the sun drying. The dryer can be operated in any climatic conditions: as a solar dryer on normal sunny days, as a biomass dryer at night time and as a hybrid dryer on cloudy days. Based on the experimental study, it is concluded that the developed hybrid dryer is suitable for small scale cashew nut farmers in rural areas of developing countries.

  20. Study and modeling of energy performance of a hybrid photovoltaic/thermal solar collector: Configuration suitable for an indirect solar dryer

    International Nuclear Information System (INIS)

    Slimani, Mohamed El Amine; Amirat, Madjid; Bahria, Sofiane; Kurucz, Ildikó; Aouli, M’heni; Sellami, Rabah

    2016-01-01

    Highlights: • The simulation results are in compliance with the experimental measurements indicated in the previous literature. • The accuracy of the numerical model is due to the presented energy analysis and also to the well-adopted correlations. • A comparative study between two solar photovoltaic/thermal air collectors was carried out. • The thermal efficiency of the analyzed hybrid collector increased by 30.85% compared to the basic configuration. • The air temperature supplied by a double-pass photovoltaic/thermal collector is very suitable for solar drying. - Abstract: In this paper, a configuration of photovoltaic-thermal hybrid solar collector embeddable in an indirect solar dryer system is studied. In the present structure of the solar photovoltaic/thermal air collector, the air goes through a double pass below and above the photovoltaic module. A system of electrical and thermal balance equations is developed and analyzed governing various electric and heat transfer parameters in the solar hybrid air collector. The numerical model planned for this study gives a good precision of results, which are close to the experimental ones (of previous literature), and makes it possible to have a good assessment of energy performance regarding the studied configuration (temperature, electric and thermal powers, electrical and thermal efficiencies, etc.). The numerical results show the energy effectiveness of this hybrid collector configuration and particularly its interesting use in an indirect solar dryer system that provides a more suitable air temperature for drying agricultural products. The values of the electrical, thermal and overall energy efficiencies reaches 10.5%, 70% and 90% respectively, with a mass flow rate of 0.0155 kg/s and weather data sample for the month of June in the Algiers site. The results presented in this study also reveal how important the effect of certain parameters and operating conditions on the performance of the hybrid

  1. A new photovoltaic solar-assisted loop heat pipe/heat-pump system%新型光伏-太阳能环形热管/热泵复合系统

    Institute of Scientific and Technical Information of China (English)

    张龙灿; 裴刚; 张涛; 季杰

    2014-01-01

    The photovoltaic solar assisted loop heat pipe system/heat-pump (PV-SALHP/HP) is the combination of solar assisted loop heat pipe system (SALHP) and solar assisted heat pipe (SAHP). A photovoltaic/thermal (PVT) evaporator and condenser could be shared by two circling modes, and so is the working medium. The loop heat pipe mode will be utilized when solar radiation is strong and the temperature of working medium in PVT evaporator is higher than that in condenser. Correspondingly, the heat pump mode will be started when solar radiation is weak or the temperature difference of working medium in PVT evaporator and condenser cannot satisfy the condition of loop heat pipe mode. The loop heat pipe mode is passive and the heat pump mode is active, which means that the loop heat pipe mode does not consume work and the heat pump mode does. Therefore, the transformable mode of system could heavily reduce power consumption, raise the utilization ratio of solar energy, and promote energy saving. A PV-SAHP/LHP test rig is built. The instantaneous and daily performance of the loop heat pipe mode and heat pump mode is studied.%光伏-太阳能环形热管/热泵复合系统将太阳能环形热管循环模式和太阳能热泵循环模式有机结合,两者采用相同的工质,共用一个PVT蒸发器和冷凝器。当太阳辐照强度较强,工质在PVT蒸发器中的温度高于冷凝器中的温度时,可以利用环形热管模式制热;当太阳辐照强度较弱或工质在PVT蒸发器中与冷凝器中的温差无法满足环形热管模式运行时,可以利用热泵模式制热。两种模式既能够独立运行,又可以互相切换,确保热能的稳定供应,同时能够明显降低系统耗电量。搭建了光伏-太阳能环形热管/热泵复合系统实验平台,对复合系统在环形热管模式和热泵模式独立运行时的瞬时性能和全天性能进行了实验研究。

  2. Flexible polyimide films hybrid with functionalized boron nitride and graphene oxide simultaneously to improve thermal conduction and dimensional stability.

    Science.gov (United States)

    Tsai, Mei-Hui; Tseng, I-Hsiang; Chiang, Jen-Chi; Li, Jheng-Jia

    2014-06-11

    Coupling agent-functionalized boron nitride (f-BN) and glycidyl methacrylate-grafted graphene (g-TrG) are simultaneously blended with polyimide (PI) to fabricate a flexible, electrically insulating and thermally conductive PI composite film. The silk-like g-TrG successfully fills in the gap between PI and f-BN to complete the thermal conduction network. In addition, the strong interaction between surface functional groups on f-BN and g-TrG contributes to the effective phonon transfer in the PI matrix. The thermal conductivity (TC) of the PI/f-BN composite films containing additional 1 wt % of g-TrG is at least doubled to the value of PI/f-BN and as high as 16 times to that of the pure PI. The hybrid film PI/f-BN-50/g-TrG-1 exhibits excellent flexibility, sufficient insulating property, the highest TC of 2.11 W/mK, and ultralow coefficient of thermal expansion of 11 ppm/K, which are perfect conditions for future flexible substrate materials requiring efficient heat dissipation.

  3. Prediction of thermal behaviors of an air-cooled lithium-ion battery system for hybrid electric vehicles

    Science.gov (United States)

    Choi, Yong Seok; Kang, Dal Mo

    2014-12-01

    Thermal management has been one of the major issues in developing a lithium-ion (Li-ion) hybrid electric vehicle (HEV) battery system since the Li-ion battery is vulnerable to excessive heat load under abnormal or severe operational conditions. In this work, in order to design a suitable thermal management system, a simple modeling methodology describing thermal behavior of an air-cooled Li-ion battery system was proposed from vehicle components designer's point of view. A proposed mathematical model was constructed based on the battery's electrical and mechanical properties. Also, validation test results for the Li-ion battery system were presented. A pulse current duty and an adjusted US06 current cycle for a two-mode HEV system were used to validate the accuracy of the model prediction. Results showed that the present model can give good estimations for simulating convective heat transfer cooling during battery operation. The developed thermal model is useful in structuring the flow system and determining the appropriate cooling capacity for a specified design prerequisite of the battery system.

  4. Numerical Study on the Seismic Performance of a Steel–Concrete Hybrid Supporting Structure in Thermal Power Plants

    Directory of Open Access Journals (Sweden)

    Bo Wang

    2018-02-01

    Full Text Available This paper presents the numerical investigation on the seismic performance of a steel–concrete hybrid structure consisting of reinforced concrete (RC tubular columns and steel braced truss with A-shaped steel frames, which is a novel supporting structural system to house air-cooled condensers (ACC in large-capacity thermal power plants (TPPs. First, the finite element (FE modeling approach for this hybrid structure using the software ABAQUS was validated by a range of pseudo-dynamic tests (PDTs performed on a 1/8-scaled sub-structure. The failure process, lateral displacement responses, changing rules of dynamic characteristic parameters and lateral stiffness with increase of peak ground acceleration (PGA were presented here. Then, nonlinear time-history analysis of the prototype structure was carried out. The dynamic characteristics, base shear force, lateral deformation capacity, stiffness deterioration and damage characteristics were investigated. Despite the structural complexity and irregularity, both experimental and numerical results indicate that the overall seismic performance of this steel–concrete hybrid supporting structure meets the seismic design requirements with respect to the high-intensity earthquakes.

  5. Synthesis and Performances of Phase Change Microcapsules with a Polymer/Diatomite Hybrid Shell for Thermal Energy Storage

    Directory of Open Access Journals (Sweden)

    Yanli Sun

    2018-05-01

    Full Text Available The mechanical behavior of phase-change microcapsules (microPCMs is of vital significance for practical applications in thermal energy storage. Hence, a new type of microPCMs based on an n-octadecane (C18 core and a melamine-urea-formaldehyde (MUF/diatomite hybrid shell was developed through in situ polymerization. Based on SEM micrographs, most microPCMs exhibited a nearly spherical and smooth microstructure, with broadened particle size distributions. It was confirmed by Fourier transform infrared (FTIR that successful polymerization of diatomite into the microPCMs occurred, and that additional diatomite had no effect on the core coated by the shell. In addition, the results of the differential scanning calorimeter (DSC and Atomic Force Microscopy (AFM demonstrated that the mechanical properties of the microPCMs were remarkably improved by the addition of a moderate amount of diatomite, but that the heat enthalpy and encapsulated efficiency (η decreased slightly. The incorporation of 2 wt % diatomite resulted in the average Young’s modulus of microPCMs, which was 1.64 times greater than those of microPCMs without diatomite. Furthermore, the melting and crystallization enthalpies and the encapsulated efficiency of the microPCMs were as high as 237.6 J/g, 234.4 J/g and 77.90%, respectively. The microPCMs with a polymer/diatomite hybrid shell may become the potential materials in the application of thermal energy storage.

  6. An experimental study on the thermal-hydraulic phenomena in the Hybrid Safety Injection Tank using a separate effect test facility

    International Nuclear Information System (INIS)

    Ryu, Sung Uk; Ryu, Hyobong; Park, Hyun-Sik; Yi, Sung-Jae

    2016-01-01

    Highlights: • The experimental study on the pressure balancing between the Hybrid SIT and PZR. • The effects of different variables affecting the pressure balancing are investigated. • A sensitivity analysis on the pressure variations of the Hybrid SIT. - Abstract: This paper reports an experimental research for investigating thermal hydraulic phenomena of Hybrid Safety Injection Tank (Hybrid SIT) using a separate effect test facility in Korea Atomic Energy Research Institute (KAERI). The Hybrid SIT is a passive safety injection system that enables the safety injection water to be injected into the reactor pressure vessel throughout all operating pressures by connecting the top of the SIT and the pressurizer (PZR). The separate effect test (SET) facility of Hybrid SIT, which is designed based on the APR+ power plant, comprises a PZR, Hybrid SIT, pressure balancing line (PBL), injection line (IL), nitrogen gas line, and refueling water tank (RWT). Furthermore, the pressure loss range of the SET facility was analyzed and compared with that of the reference nuclear power plant. In this research, a condition for balancing the pressure between the Hybrid SIT and PZR is examined and the effects of different variables affecting the pressure balancing, which are flow rate, injection velocity of steam and initial water level, are also investigated. The condition for balancing the pressure between the Hybrid SIT and PZR was derived theoretically from a pressure network for the Hybrid SIT, pressurizer, and reactor pressure vessel. Additionally, a sensitivity analysis as a theoretical approach was conducted on the pressure variations in relation to the rate of steam condensation inside the Hybrid SIT. The results showed that pressure of the Hybrid SIT was predominantly determined by the rate of steam condensation. The results showed that if the rate of condensation increased or decreased by 10%, the Hybrid SIT pressure at the pressure balancing point decreased or

  7. Remanagement of Singlet and Triplet Excitons in Single-Emissive-Layer Hybrid White Organic Light-Emitting Devices Using Thermally Activated Delayed Fluorescent Blue Exciplex.

    Science.gov (United States)

    Liu, Xiao-Ke; Chen, Zhan; Qing, Jian; Zhang, Wen-Jun; Wu, Bo; Tam, Hoi Lam; Zhu, Furong; Zhang, Xiao-Hong; Lee, Chun-Sing

    2015-11-25

    A high-performance hybrid white organic light-emitting device (WOLED) is demonstrated based on an efficient novel thermally activated delayed fluorescence (TADF) blue exciplex system. This device shows a low turn-on voltage of 2.5 V and maximum forward-viewing external quantum efficiency of 25.5%, which opens a new avenue for achieving high-performance hybrid WOLEDs with simple structures. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Facile preparation of carbon nanotubes-graphene hybrids and the effect of aspect ratio of carbon nanotubes on electrical and thermal properties of silicone rubber based composites

    Science.gov (United States)

    Zhao, Shizhen; Bai, Lu; Zheng, Junping

    2018-01-01

    Thermal exfoliation, as an effective and easily scalable method, was widely used to produce graphene (GE). In order to prevent the severe stacking of GE sheets after thermal exfoliation process, a facile technique was used to solve this problem through the barrier effect of carbon nanotubes (CNTs). Two kinds of CNTs with different aspect ratios (AR) were taken to prepare CNTs-GE hybrids using this technique, and then the effect of AR of CNTs (namely CNTs-L for low AR and CNTs-H for high AR) in the hybrids on the performance of silicone rubber (SR) composites was investigated. The results indicate that the presence of CNTs can effectively impede the stacking of GE sheets and the hybrids are dispersed uniformly in the SR matrix. With the addition of CNTs-GE hybrids, the resulted SR composites exhibit greatly improved electrical and thermal properties, especially for the composites filled with CNTs-H-GE hybrid. At the hybrids content of 3.0 wt%, the volume resistivity of CNTs-H-GE/SR composite is 5 × 104 Ω cm (about 10 orders of magnitude decrease compared with pure SR). And the thermal conductivity increases by 78% compared to the pure SR. But as for the CNTs-L-GE/SR composite, the corresponding values are 3 × 106 Ω cm and 59%, respectively. In terms of thermal stability, the CNTs-H-GE/SR composite containing 1.0 wt% hybrid exhibits the maximum improvement of initial degradation temperature (419 °C) compared with the CNTs-L-GE/SR composite (393 °C) and pure SR (365 °C).

  9. Synthesis, structural, thermal and optical studies of inorganic-organic hybrid semiconductors, R-PbI4

    Science.gov (United States)

    Pradeesh, K.; Nageswara Rao, K.; Vijaya Prakash, G.

    2013-02-01

    Wide varieties of naturally self-assembled two-dimensional inorganic-organic (IO) hybrid semiconductors, (4-ClC6H4NH3)2PbI4, (C6H9C2H4NH3)2PbI4, (CnH2n+1NH3)2PbI4 (where n = 12, 16, 18), (CnH2n-1NH3)2PbI4 (where n = 3, 4, 5), (C6H5C2H4NH3)2PbI4, NH3(CH2)12NH3PbI4, and (C4H3SC2H4NH3)2PbI4, were fabricated by intercalating structurally diverse organic guest moieties into lead iodide perovskite structure. The crystal packing of all these fabricated IO-hybrids comprises of well-ordered organic and inorganic layers, stacked-up alternately along c-axis. Almost all these hybrids are thermally stable upto 200 °C and show strong room-temperature exciton absorption and photoluminescence features. These strongly confined optical excitons are highly influenced by structural deformation of PbI matrix due to the conformation of organic moiety. A systematic correlation of optical exciton behavior of IO-hybrids with the organic/inorganic layer thicknesses, intercalating organic moieties, and various structural disorders were discussed. This systematic study clearly suggests that the PbI layer crumpling is directly responsible for the tunability of optical exciton energy.

  10. Multi-objective hybrid PSO-APO algorithm based security constrained optimal power flow with wind and thermal generators

    Directory of Open Access Journals (Sweden)

    Kiran Teeparthi

    2017-04-01

    Full Text Available In this paper, a new low level with teamwork heterogeneous hybrid particle swarm optimization and artificial physics optimization (HPSO-APO algorithm is proposed to solve the multi-objective security constrained optimal power flow (MO-SCOPF problem. Being engaged with the environmental and total production cost concerns, wind energy is highly penetrating to the main grid. The total production cost, active power losses and security index are considered as the objective functions. These are simultaneously optimized using the proposed algorithm for base case and contingency cases. Though PSO algorithm exhibits good convergence characteristic, fails to give near optimal solution. On the other hand, the APO algorithm shows the capability of improving diversity in search space and also to reach a near global optimum point, whereas, APO is prone to premature convergence. The proposed hybrid HPSO-APO algorithm combines both individual algorithm strengths, to get balance between global and local search capability. The APO algorithm is improving diversity in the search space of the PSO algorithm. The hybrid optimization algorithm is employed to alleviate the line overloads by generator rescheduling during contingencies. The standard IEEE 30-bus and Indian 75-bus practical test systems are considered to evaluate the robustness of the proposed method. The simulation results reveal that the proposed HPSO-APO method is more efficient and robust than the standard PSO and APO methods in terms of getting diverse Pareto optimal solutions. Hence, the proposed hybrid method can be used for the large interconnected power system to solve MO-SCOPF problem with integration of wind and thermal generators.

  11. Critical thermal maxima of two geographic strains of channel and hybrid catfish

    Science.gov (United States)

    Critical thermal maxima have been used extensively to provide physiologically and ecologically valuable reference points that identify early signs of thermal stress. In catfish pond culture, daily temperature maxima up to 36'C and daily fluctuations of as much as 6'Care observed. These extreme condi...

  12. Oil sorption and retention capacities of thermally-bonded hybrid nonwovens prepared from cotton, kapok, milkweed and polypropylene fibers.

    Science.gov (United States)

    Thilagavathi, G; Praba Karan, C; Das, Dipayan

    2018-08-01

    This work reports on a series of thermally-bonded, hybrid and oil-sorbent nonwovens developed from binary and tertiary mixing of cotton, kapok, and three varieties of milkweed fibers (Asclepias Syriaca, Calotropis Procera and Calotropis Gigantea) and polypropylene fibers. The physical and chemical properties of the fibers were investigated to examine their oleophilic character. It was observed that all the fiber surfaces were covered with natural wax. Further, kapok and milkweed fibers were found to have less cell wall thickness and high void ratio. Oil sorption and retention characteristics of these fibers were studied in loose fibrous form as well as in structured assembly form (thermally-bonded nonwovens) using high density oil and diesel oil. The effects of fiber diameter, fiber cross-sectional shape, fiber surface area and porosity on the oil sorption behavior were discussed. An excellent and a selective oil sorption behavior of milkweed fibers (Calotropis Procera and Calotropis Gigantea) blended with cotton and polypropylene fibers were observed. The maximum oil sorption capacity of the developed thermal bonded nonwoven was 40.16 g/g for high density (HD) oil and 23.00 g/g for diesel oil. Further, a high porosity combined with high surface area played a major role in deciding the oil sorption and retention characteristics. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Evaluation of the Effect of Operating Parameters on Thermal Performance of an Integrated Starter Generator in Hybrid Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Moo-Yeon Lee

    2015-08-01

    Full Text Available The belt-driven-type integrated starter generator motor in a hybrid electric vehicle is vulnerable to thermal problems owing to its high output power and proximity to the engine. These problems may cause demagnetization and insulation breakdown, reducing the performance and durability of the motor. Hence, it is necessary to evaluate the thermal performance and enhance the cooling capacity of the belt-driven type Integrated Starter Generator. In this study, the internal temperature variations of the motor were investigated with respect to the operating parameters, particularly the rotation speed and environment temperature. At a maximum ambient temperature of 105 °C and rotation speed (motor design point of 4500 rpm, the coil of the motor was heated to approximately 189 °C in generating mode. The harsh conditions of the starting mode were analyzed by assuming that the motor operates during the start-up time at a maximum ambient temperature of 105 °C and rotation speed (motor design point of 800 rpm; the coil was heated to approximately 200 °C, which is close to the insulation temperature limit. The model for analyzing the thermal performance of the ISG was verified by comparing its results with those obtained through a generating-mode-based experiment

  14. Hybrid Heat Pipes for High Heat Flux Spacecraft Thermal Control, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Grooved aluminum/ammonia Constant Conductance Heat Pipes (CCHPs) are the standard for thermal control in zero-gravity. Unfortunately, they are limited in terms of...

  15. Electrically and Thermally Conductive Low Density Polyethylene-Based Nanocomposites Reinforced by MWCNT or Hybrid MWCNT/Graphene Nanoplatelets with Improved Thermo-Oxidative Stability

    Directory of Open Access Journals (Sweden)

    Sandra Paszkiewicz

    2018-04-01

    Full Text Available In this paper, the electrical and thermal conductivity and morphological behavior of low density polyethylene (LDPE/multi-walled carbon nanotubes (MWCNTs + graphene nanoplatelets (GNPs hybrid nanocomposites (HNCs have been studied. The distribution of MWCNTs and the hybrid of MWCNTs/GNPs within the polymer matrix has been investigated with scanning electron microscopy (SEM. The results showed that the thermal and electrical conductivity of the LDPE-based nanocomposites increased along with the increasing content of carbon nanofillers. However, one could observe greater improvement in the thermal and electrical conductivity when only MWCNTs have been incorporated. Moreover, the improvement in tensile properties and thermal stability has been observed when carbon nanofillers have been mixed with LDPE. At the same time, the increasing content of MWCNTs and MWCNTs/GNPs caused an increase in the melt viscosity with only little effect on phase transition temperatures.

  16. Electrically and Thermally Conductive Low Density Polyethylene-Based Nanocomposites Reinforced by MWCNT or Hybrid MWCNT/Graphene Nanoplatelets with Improved Thermo-Oxidative Stability.

    Science.gov (United States)

    Paszkiewicz, Sandra; Szymczyk, Anna; Pawlikowska, Daria; Subocz, Jan; Zenker, Marek; Masztak, Roman

    2018-04-22

    In this paper, the electrical and thermal conductivity and morphological behavior of low density polyethylene (LDPE)/multi-walled carbon nanotubes (MWCNTs) + graphene nanoplatelets (GNPs) hybrid nanocomposites (HNCs) have been studied. The distribution of MWCNTs and the hybrid of MWCNTs/GNPs within the polymer matrix has been investigated with scanning electron microscopy (SEM). The results showed that the thermal and electrical conductivity of the LDPE-based nanocomposites increased along with the increasing content of carbon nanofillers. However, one could observe greater improvement in the thermal and electrical conductivity when only MWCNTs have been incorporated. Moreover, the improvement in tensile properties and thermal stability has been observed when carbon nanofillers have been mixed with LDPE. At the same time, the increasing content of MWCNTs and MWCNTs/GNPs caused an increase in the melt viscosity with only little effect on phase transition temperatures.

  17. Thermal and Mechanical Properties of Novolac-Silica Hybrid Aerogels Prepared by Sol-Gel Polymerization in Solvent-Saturated Vapor Atmosphere

    Directory of Open Access Journals (Sweden)

    Mohamad Mehdi Seraji1, Seraji

    2015-05-01

    Full Text Available Nowadays organic–inorganic hybrid aerogel materials have attracted increasing interests due to improved thermal and mechanical properties. In the present research, initially, novolac type phenolic resin-silica hybrid gels with different solid concentrations were synthesized using sol-gel polymerization in solvent-saturatedvapor atmosphere. The hybrid gels were dried at air atmosphere through ambient drying process. This method removed the need for costly and risky supercritical drying process. The yields of the obtained hybrid aerogels increased with less shrinkage in comparison with conventional sol-gel process. The precursor of silica phase in this study was tetraethoxysilane and inexpensive novolac resin was used as a reinforcing phase. The results of FTIR analysis confirmed the simultaneous formation of silica and novolac gels in the hybrid systems. The resultant hybrid aerogels showed a nanostructure hybrid network with high porosity (above 80% and low density (below 0.25 g/cm3. Nonetheless, higher content of silica resulted in more shrinkage in the hybrid aerogel structure due to the tendency of the silica network to shrink more during gelation and drying process. The SEM images of samples exhibited a continuous network of interconnected colloidal particles formed during sol-gel polymerization with mean particle size of less than 100 nanometers. Si mapping analysis showed good distribution of silica phase throughout the hybrid structure. The results demonstrated improvements in insulation properties and thermal stability of novolac-silica aerogel with increasing the silica content. The results of compressive strength showed that the mechanical properties of samples declined with increasing the silica content.

  18. PEG/SiO2–Al2O3 hybrid form-stable phase change materials with enhanced thermal conductivity

    International Nuclear Information System (INIS)

    Tang, Bingtao; Wu, Cheng; Qiu, Meige; Zhang, Xiwen; Zhang, Shufen

    2014-01-01

    The thermal conductivity of form-stable PEG/SiO 2 phase change material (PCM) was enhanced by in situ doping of Al 2 O 3 using an ultrasound-assisted sol–gel method. Fourier transform infrared spectroscopy (FT-IR) was used to characterize the structure, and the crystal performance was characterized by the X-ray diffraction (XRD). Differential scanning calorimetry (DSC) and thermogravimetric analyzer (TGA) were used to determine the thermal properties. The phase change enthalpy of PEG/SiO 2 –Al 2 O 3 reached 124 J g −1 , and thermal conductivity improved by 12.8% for 3.3 wt% Al 2 O 3 in the PCM compared with PEG/SiO 2 . The hybrid PCM has excellent thermal stability and form-stable effects. - Highlights: • The PEG/SiO 2 –Al 2 O 3 hybrid form-stable phase change material (PCM) was obtained through the sol–gel method. • The inexpensive aluminum nitrate and tetraethyl orthosilicate were used as sol precursors. • This organic–inorganic hybrid process can effectively enhance the thermal conductivity of PCMs. • The PCM exhibited high thermal stability and excellent form-stable effects

  19. PEG/SiO{sub 2}–Al{sub 2}O{sub 3} hybrid form-stable phase change materials with enhanced thermal conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Bingtao, E-mail: tangbt@dlut.edu.cn; Wu, Cheng; Qiu, Meige; Zhang, Xiwen; Zhang, Shufen

    2014-03-01

    The thermal conductivity of form-stable PEG/SiO{sub 2} phase change material (PCM) was enhanced by in situ doping of Al{sub 2}O{sub 3} using an ultrasound-assisted sol–gel method. Fourier transform infrared spectroscopy (FT-IR) was used to characterize the structure, and the crystal performance was characterized by the X-ray diffraction (XRD). Differential scanning calorimetry (DSC) and thermogravimetric analyzer (TGA) were used to determine the thermal properties. The phase change enthalpy of PEG/SiO{sub 2}–Al{sub 2}O{sub 3} reached 124 J g{sup −1}, and thermal conductivity improved by 12.8% for 3.3 wt% Al{sub 2}O{sub 3} in the PCM compared with PEG/SiO{sub 2}. The hybrid PCM has excellent thermal stability and form-stable effects. - Highlights: • The PEG/SiO{sub 2}–Al{sub 2}O{sub 3} hybrid form-stable phase change material (PCM) was obtained through the sol–gel method. • The inexpensive aluminum nitrate and tetraethyl orthosilicate were used as sol precursors. • This organic–inorganic hybrid process can effectively enhance the thermal conductivity of PCMs. • The PCM exhibited high thermal stability and excellent form-stable effects.

  20. Character of photovoltaic/thermal hybrid collector. Character analysis by numerical calculation; Taiyoko netsu hybrid collector no tokusei. Suchi keisan ni yoru tokusei kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Morita, Y; Iwawaki, T; Fujisawa, T; Tani, T [Science University of Tokyo, Tokyo (Japan)

    1997-11-25

    In order to investigate characteristics of photovoltaic (PV)/thermal hybrid collectors (PV/T{sub s}) operating under varying conditions, energy equilibrium equations have been developed for numerical calculation, and the calculated results were compared with the observed ones. The calculated characteristics are close to the observed ones, both for photoelectric conversion and heat collecting characteristics, demonstrating validity of these energy equations. It is found, by comparing characteristics of PV/T{sub A} (covered with glass) with those of PV/T{sub B} (not covered with glass), that these characteristics are greatly affected by glass cover. Maximum overall excergy levels attained are 13.29% with PV/T{sub A} and 11.48% with PV/T{sub B} under the conditions of solar radiation intensity H: 800W/m{sup 2}, ambient temperature: 20degC and wind velocity: 0.5m/s, where flow rates of heat medium are 2.0times10{sup -3} and 4.0times10{sup -3}kg/s, respectively. Thus, the PV/T{sub A} system has a higher maximum excergy efficiency than the PV/T{sub B} system. The PV/T{sub A} gives water of higher temperature, demonstrating that covering the system with glass increases maximum excergy efficiency and optimum temperature. 6 refs., 5 figs., 2 tabs.

  1. Hybrid Particle Swarm Optimization based Day-Ahead Self-Scheduling for Thermal Generator in Competitive Electricity Market

    DEFF Research Database (Denmark)

    Pindoriya, Naran M.; Singh, S.N.; Østergaard, Jacob

    2009-01-01

    in day-ahead energy market subject to operational constraints and 2) at the same time, to minimize the risk due to uncertainty in price forecast. Therefore, it is a conflicting bi-objective optimization problem which has both binary and continuous optimization variables considered as constrained mixed......This paper presents a hybrid particle swarm optimization algorithm (HPSO) to solve the day-ahead self-scheduling for thermal power producer in competitive electricity market. The objective functions considered to model the self-scheduling problem are 1) to maximize the profit from selling energy...... integer nonlinear programming. To demonstrate the effectiveness of the proposed method for self-scheduling in a day-ahead energy market, the locational margin price (LMP) forecast uncertainty in PJM electricity market is considered. An adaptive wavelet neural network (AWNN) is used to forecast the day...

  2. HDPE/clay hybrids: the effect of clay modified with poly(diphenyl siloxanes) on thermal and rheological properties

    Energy Technology Data Exchange (ETDEWEB)

    Monasterio, Fernanda E.; Carrera, Maria C.; Erdmann, Eleonora; Destefanis, Hugo A., E-mail: ferelenakq@gmail.co [Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Buenos Aires (Argentina). Inst. de Investigaciones para la Industria Quimica; Pita, Victor J.R.R.; Dias, Marcos L. [Universidade Federal do Rio de Janeiro (IMA/UFRJ), RJ (Brazil). Inst. de Macromoleculas Profa. Eloisa Mano

    2009-07-01

    Poly(diphenyl siloxanes) (PDPhS) were synthesized in presence of organophilic clay in order to modify its nano structure. Two silane monomers were used: dimethoxydiphenylsilane and dichlorodiphenylsilane. The following characterizations were performed for all clays: XRD, FTIR and TGA/DTG. These siloxane-modified clays were more hydrophobic and had enhanced thermal stability. Solvent extraction was carried out in the siloxane-modified clays and the PDPhS soluble fraction analyzed according the molecular weight via GPC. The presence of free and grafted oligomers on clay surface was identified. The modified clays were added to HDPE by melt processing to obtain HDPE/clay hybrids which exhibited marked differences in the rheological behavior when compared with neat HDPE. (author)

  3. HDPE/clay hybrids: the effect of clay modified with poly(diphenyl siloxanes) on thermal and rheological properties

    International Nuclear Information System (INIS)

    Monasterio, Fernanda E.; Carrera, Maria C.; Erdmann, Eleonora; Destefanis, Hugo A.; Pita, Victor J.R.R.; Dias, Marcos L.

    2009-01-01

    Poly(diphenyl siloxanes) (PDPhS) were synthesized in presence of organophilic clay in order to modify its nano structure. Two silane monomers were used: dimethoxydiphenylsilane and dichlorodiphenylsilane. The following characterizations were performed for all clays: XRD, FTIR and TGA/DTG. These siloxane-modified clays were more hydrophobic and had enhanced thermal stability. Solvent extraction was carried out in the siloxane-modified clays and the PDPhS soluble fraction analyzed according the molecular weight via GPC. The presence of free and grafted oligomers on clay surface was identified. The modified clays were added to HDPE by melt processing to obtain HDPE/clay hybrids which exhibited marked differences in the rheological behavior when compared with neat HDPE. (author)

  4. Exergy analysis and optimization of a thermal management system with phase change material for hybrid electric vehicles

    International Nuclear Information System (INIS)

    Javani, N.; Dincer, I.; Naterer, G.F.; Yilbas, B.S.

    2014-01-01

    In the present study, energy and exergy analyses are conducted to investigate a new cooling system of hybrid electric vehicles (HEVs). A latent heat thermal energy storage system is integrated with an active refrigeration cycle where octadecane is selected as the phase change material (PCM). The liquid cooling system flows through the chiller following a conventional vapor compression cooling cycle. The latent heat shell and the tube heat exchanger operate in parallel with the chiller and a fraction of coolant enters the heat exchanger and, therefore, decreases the heat load of the chiller, leading to a lower work required by the compressor. The exergy destruction rate and the exergy efficiency of each component in a hybrid thermal management system (TMS) are calculated. In addition, the effects of parameters such as the fraction of coolant entering the heat storage system (PCM mass fraction), evaporator temperature, and compressor pressure ratio on the system performance are investigated. The findings of the exergy analysis reveal that the overall exergy efficiency of the system with PCM presence is 31%, having the largest exergy destruction rate of 0.4 kW and the heat exchangers have lower exergy efficiency as compared to other components. In addition, the results of the parametric study show that an increase in PCM mass fraction results in an increase in exergy efficiency of the system. An environmental impact assessment is also conducted and the results show that an increase in exergy efficiency of the cooling system reduces greenhouse gasses and also increases the sustainability of the system. Moreover, a multi-objective optimization using the genetic algorithm is performed by incorporating two objective functions, namely exergy efficiency to be maximized and total cost rate of the system to be minimized. A Pareto frontier is obtained and a single desirable optimal solution is selected based on LINMAP decision-making process. The results show that the maximum

  5. 相变储能光伏太阳能热泵干燥系统的研究%Research on Phase Change Energy Storage Photovoltaic Solar Heat Pump Drying System

    Institute of Scientific and Technical Information of China (English)

    胡静; 蒋绿林; 侯亚祥; 王昌领; 张亮

    2017-01-01

    The experimental platform of phase change energy storage photovoltaic solar heat pump drying system is estab-lished in this paper ,it is introduced the way of the system and the matching of photovoltaic solar heating evaporator and dc compressor is calculated and finally the experiment data is analyzed in detail .It is concluded that when the solar radiation amount is 800 W/m2 and photovoltaic solar heating evaporator area is 12 m2 ,heat capacity is 10 kW and solar photovoltaic power generation is 6 .2 kW·h ,in which the photovoltaic power consumption is greater than the compressor ,meeting the op-eration requirements without additional power .The COP of system is 3 .25 .The phase change energy storage can solve run-ning problem of the system ,which is caused by the amount of solar irradiance fluctuation ,and so it has significant energy saving and environmental protection .%建立了相变储能光伏太阳能热泵干燥系统实验平台,介绍了系统的运行方式以及太阳能光伏集热蒸发器与直流压缩机的匹配计算,最后对实验数据进行了分析。结果表明,太阳能辐照量为800 W/m2、光伏集热蒸发器面积为12m2的条件下,系统制热功率为10kW,太阳能光伏集热蒸发器发电量为6.2kW·h,大于直流压缩机的耗电量,满足供电要求;实验所得系统COP为3.25。相变储能可以解决太阳辐照波动导致的系统运行不稳定问题,具有显著的节能性和环保性。

  6. Elevated [CO2] magnifies isoprene emissions under heat and improves thermal resistance in hybrid aspen

    OpenAIRE

    Sun, Zhihong; H?ve, Katja; Vislap, Vivian; Niinemets, ?lo

    2013-01-01

    Isoprene emissions importantly protect plants from heat stress, but the emissions become inhibited by instantaneous increase of [CO2], and it is currently unclear how isoprene-emitting plants cope with future more frequent and severe heat episodes under high [CO2]. Hybrid aspen (Populus tremula x Populus tremuloides) saplings grown under ambient [CO2] of 380 ?mol mol?1 and elevated [CO2] of 780 ?mol mol?1 were used to test the hypothesis that acclimation to elevated [CO2] reduces the inhibito...

  7. Effect of Tank Size on the Temperature Distributions for Hybrid Photovoltaic/Thermal Water Heaters

    OpenAIRE

    Al-Masri, Ahmad

    2016-01-01

    In the present study an investigation was conducted on the temperature distribution effect for several tank capacities (100 L, 120 L, 150 L and 200 L) having two different aspect ratios (H/D) for each capacity. Hot water is supplied to these tanks by a Hybrid PV/T collector of 4 m² illuminating area. The circulation of water within PV cells cools its surface area to solve the problem occurred in PV cells, where each 1°C increase in the surface module 0.45% of the electrical efficiency decreas...

  8. Development of plasma properties along thermal plasma jet generated by hybrid water-argon torch

    Czech Academy of Sciences Publication Activity Database

    Kavka, Tetyana; Hrabovský, Milan

    2002-01-01

    Roč. 52, supplement D (2002), s. 637-642 ISSN 0011-4626. [Symposium on Plasma Physics and Technology/20th./. Prague, 10.06.2002-13.06.2002] Institutional research plan: CEZ:AV0Z2043910 Keywords : thermal plasma, plasma jet, enthalpy probe Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.311, year: 2002

  9. Model Predictive Control of Hybrid Thermal Energy Systems in Transport Refrigeration

    DEFF Research Database (Denmark)

    Shafiei, Seyed Ehsan; Alleyne, Andrew

    2015-01-01

    A predictive control scheme is designed to control a transport refrigeration system, such as a delivery truck, that includes a vapor compression cycle configured in parallel with a thermal energy storage (TES) unit. A novel approach to TES utilization is introduced and is based on the current...

  10. Thermoelectrics as elements of hybrid-electric vehicle thermal energy systems

    Science.gov (United States)

    Headings, Leon; Washington, Gregory; Jaworski, Christopher M.

    2008-03-01

    Despite vast technological improvements, the traditional internal combustion powered vehicle still achieves only 25- 30% efficiency, with the remainder lost primarily as heat. While the load leveling offered by hybrid-electric vehicle technology helps to improve this overall efficiency, part of the efficiency gains are achieved by making new systems such as regenerative braking viable. In a similar fashion, thermoelectric (TE) energy recovery has long been considered for traditional vehicles with mixed results, but little has been done to consider thermoelectrics in the framework of the unique energy systems of hybrid vehicles. Systems that may not have been viable or even possible with traditional vehicles may offer improvements to system efficiency as well as emissions, vehicle durability, passenger comfort, and cost. This research describes a simulation developed for evaluating and optimizing thermoelectric energy recovery systems and results for four different system configurations. Two novel system configurations are presented which offer the potential for additional benefits such as emissions reduction that will soon be quantified. In addition, a test setup is presented which was constructed for the testing and validation of various thermoelectric recovery systems. Actual test performance was near the expected theoretical performance and supported the conclusions reached from the computer simulations.

  11. Thermal Performance of Motor and Inverter in an Integrated Starter Generator System for a Hybrid Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Sung Chul Kim

    2013-11-01

    Full Text Available If the integrated starter generator (ISG motor and inverter operate under continuously high loading conditions, the system’s performance and durability will decrease and the heat dissipation requirements will increase. Therefore, in this study, we developed two cooling designs for the ISG motor and inverter, and then carried out both a model analysis and an experiment on the fluid flow and thermal characteristics of the system under various operating conditions. As the outdoor temperature increased from 25 °C to 95 °C, the coil temperature of the air-cooled motor increased by about 82 °C. Under the harsh-air condition of 95 °C, the coil of the air-cooled motor increased to a maximum temperature of about 158.5 °C. We also determined that the temperature of the metal-oxide-semiconductor field-effect transistor (MOSFET chip in the liquid-cooled inverter increased to a maximum temperature of about 96.8 °C under a coolant flow rate of 4 L/min and a coolant temperature of 65 °C. The observed thermal performance of the ISG motor and inverter using the proposed cooling structures was found to be sufficient for heat loads under various real driving conditions for a hybrid electric vehicle (HEV.

  12. Kinetics of Waterborne Alkyd/Acrylic Hybrid Resin Free Radical Polymerization by Two Systems of Redox and Thermal Initiators

    Directory of Open Access Journals (Sweden)

    shirin Madadi

    2012-12-01

    Full Text Available Kinetics of radical polymerizations of waterborne alkyd/acrylic hybrid resin via batch mini-emulsion technique was studied using redox initiators (TBHP/Fe2+/EDTA/AsAc  and  TBHP/Fe2+/EDTA/SFS at relatively low temperatures and thermal initiators (BPO, KPS and AIBN at higher temperatures to seek the most suitable initiator system. At the end of all reactions the unreacted monomer content was reduced using post-polymerization technique; consequently, leading to increased monomer conversion and flm formation with improved properties. The kinetics of mini-emulsion polymerization showed that in all redox initiator systems (Fe2+ catalyst + EDTA chelating agent, the radials are produced at relatively low temperature with more effcient control of the reactor temperature. It was found that at 45°C TBHP/Fe2+/EDTA/SFS redox initiator system leads to 98% monomer conversion, a much higher rate than that of systems involved thermal initiators.

  13. Analysis of environmental effect of hybrid solar-assisted desalination cycle in Sirdarya Thermal Power Plant, Uzbekistan

    International Nuclear Information System (INIS)

    Alikulov, Khusniddin; Xuan, Tran Dang; Higashi, Osamu; Nakagoshi, Nobukazu; Aminov, Zarif

    2017-01-01

    Highlights: • A hybrid solar-assisted desalination cycle was designed and stimulated. • Maximum of 21,064.00 kW effective solar heat can be achieved. • The use of parabolic-trough collectors in the Multi Effect Distillation is potential. • The cycle can be applied in other regions with high Direct Normal Irradiation. - Abstract: This study was to investigate possible reduction of fossil fuel consumption and carbon dioxide emission in one of energy sectors of Sirdarya Thermal Power Plant (TPP), Uzbekistan. A hybrid solar-assisted desalination cycle has been designed and simulated for partially supplying saturated steam with 200 °C, 8 bar, and 32 t/h parameters to a Multi Effect Distillation (MED) process in the Sirdarya Thermal Power Plant. The outcome of the parental design model stated that maximum, 21,064.00 kW effective solar heat can be achieved, which is equivalent to 31.76 t/h of saturated steam with 200 °C and 8 bar parameters. Total saved fossil fuel in each month proved that it is possible to reduce fossil fuel (heavy oil and natural gas) consumption with 59.64, 95.24, 389.96, and 298.26 tons during available Direct Normal Irradiation (DNI) by using parabolic-trough collectors. Moreover, the above-mentioned fossil fuel savings accounted for CO_2 reduction with amounts of 182.50, 255.46, 1045.87 & 799.96 tons per each consistent month. Findings proved that integration of parabolic-trough collectors into the MED process is feasible in terms of high DNI availability and demand for retrofitting old existing heat-consuming facilities in Sirdarya Thermal Power Plant. Besides, the cycle also can be applied in other regions of Uzbekistan with high DNI for generating solar heat. Therefore, conducted study is eligible to be applied on the research site by taking into account of sufficient meteorological data and required steam parameters.

  14. Evaluation of thermal conductivity of MgO-MWCNTs/EG hybrid nanofluids based on experimental data by selecting optimal artificial neural networks

    Science.gov (United States)

    Vafaei, Masoud; Afrand, Masoud; Sina, Nima; Kalbasi, Rasool; Sourani, Forough; Teimouri, Hamid

    2017-01-01

    In this paper, the thermal conductivity ratio of MgO-MWCNTs/EG hybrid nanofluids has been predicted by an optimal artificial neural network at solid volume fractions of 0.05%, 0.1%, 0.15%, 0.2%, 0.4% and 0.6% in the temperature range of 25-50 °C. In this way, at the first, thirty six experimental data was presented to determine the thermal conductivity ratio of the hybrid nanofluid. Then, four optimal artificial neural networks with 6, 8, 10 and 12 neurons in hidden layer were designed to predict the thermal conductivity ratio of the nanofluid. The comparison between four optimal ANN results and experimental showed that the ANN with 12 neurons in hidden layer was the best model. Moreover, the results obtained from the best ANN indicated the maximum deviation margin of 0.8%.

  15. Evaluating the Thermal Damage Resistance of Reduced Graphene Oxide/Carbon Nanotube Hybrid Coatings

    Science.gov (United States)

    David, Lamuel; Feldman, Ari; Mansfield, Elisabeth; Lehman, John; Singh, Gurpreet; National Institute of Standards and Technology Collaboration

    2014-03-01

    Carbon nanotubes and graphene are known to exhibit some exceptional thermal (K ~ 2000 to 4400 W.m-1K-1 at 300K) and optical properties. Here, we demonstrate preparation and testing of multiwalled carbon nanotubes and chemically modified graphene-composite spray coatings for use on thermal detectors for high-power lasers. The synthesized nanocomposite material was tested by preparing spray coatings on aluminum test coupons used as a representation of the thermal detector's surface. These coatings were then exposed to increasing laser powers and extended exposure times to quantify their damage threshold and optical absorbance. The graphene/carbon nanotube (prepared at varying mass% of graphene in CNTs) coatings demonstrated significantly higher damage threshold values at 2.5 kW laser power (10.6 μm wavelength) than carbon paint or MWCNTs alone. Electron microscopy and Raman spectroscopy of irradiated specimens showed that the composite coating endured high laser-power densities (up to 2 kW.cm-2) without significant visual damage. This research is based on work supported by the National Science Foundation (Chemical, Bioengineering, Environmental, and Transport Systems Division), under grant no. 1335862 to G. Singh.

  16. The Economic Potential of Three Nuclear-Renewable Hybrid Energy Systems Providing Thermal Energy to Industry

    Energy Technology Data Exchange (ETDEWEB)

    Ruth, Mark [National Renewable Energy Lab. (NREL), Golden, CO (United States); Cutler, Dylan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Flores-Espino, Francisco [National Renewable Energy Lab. (NREL), Golden, CO (United States); Stark, Greg [National Renewable Energy Lab. (NREL), Golden, CO (United States); Jenkin, Thomas [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-12-01

    This report is one of a series of reports that Idaho National Laboratory and National Renewable Energy Laboratory are producing to investigate the technical and economic aspects of nuclear-renewable hybrid energy systems (N-R HESs). Previous reports provided results of an analysis of two N-R HES scenarios. This report builds that analysis with a Texas-synthetic gasoline scenario providing the basis in which the N-R HES sells heat directly to an industrial customer. Subsystems were included that convert electricity to heat, thus allowing the renewable energy subsystem to generate heat and benefit from that revenue stream. Nuclear and renewable energy sources are important to consider in the energy sector's evolution because both are considered to be clean and non-carbon-emitting energy sources.

  17. The Economic Potential of Three Nuclear-Renewable Hybrid Energy Systems Providing Thermal Energy to Industry

    International Nuclear Information System (INIS)

    Ruth, Mark; Cutler, Dylan; Flores-Espino, Francisco; Stark, Greg; Jenkin, Thomas

    2016-01-01

    This report is one of a series of reports that Idaho National Laboratory and National Renewable Energy Laboratory are producing to investigate the technical and economic aspects of nuclear-renewable hybrid energy systems (N-R HESs). Previous reports provided results of an analysis of two N-R HES scenarios. This report builds that analysis with a Texas-synthetic gasoline scenario providing the basis in which the N-R HES sells heat directly to an industrial customer. Subsystems were included that convert electricity to heat, thus allowing the renewable energy subsystem to generate heat and benefit from that revenue stream. Nuclear and renewable energy sources are important to consider in the energy sector's evolution because both are considered to be clean and non-carbon-emitting energy sources.

  18. On the Fracture Toughness and Crack Growth Resistance of Bio-Inspired Thermal Spray Hybrid Composites

    Science.gov (United States)

    Resnick, Michael Murray

    Surface exploration of the Moon and Asteroids can provide important information to scientists regarding the origins of the solar-system and life . Small robots and sensor modules can enable low-cost surface exploration. In the near future, they are the main machines providing these answers. Advanced in electronics, sensors and actuators enable ever smaller platforms, with compromising functionality. However similar advances haven't taken place for power supplies and thermal control system. The lunar south pole has temperatures in the range of -100 to -150 °C. Similarly, asteroid surfaces can encounter temperatures of -150 °C. Most electronics and batteries do not work below -40 °C. An effective thermal control system is critical towards making small robots and sensors module for extreme environments feasible. In this work, the feasibility of using thermochemical storage materials as a possible thermal control solution is analyzed for small robots and sensor modules for lunar and asteroid surface environments. The presented technology will focus on using resources that is readily generated as waste product aboard a spacecraft or is available off-world through In-Situ Resource Utilization (ISRU). In this work, a sensor module for extreme environment has been designed and prototyped. Our intention is to have a network of tens or hundreds of sensor modules that can communicate and interact with each other while also gathering science data. The design contains environmental sensors like temperature sensors and IMU (containing accelerometer, gyro and magnetometer) to gather data. The sensor module would nominally contain an electrical heater and insulation. The thermal heating effect provided by this active heater is compared with the proposed technology that utilizes thermochemical storage chemicals. Our results show that a thermochemical storage-based thermal control system is feasible for use in extreme temperatures. A performance increase of 80% is predicted for

  19. Optimal stochastic short-term thermal and electrical operation of fuel cell/photovoltaic/battery/grid hybrid energy system in the presence of demand response program

    International Nuclear Information System (INIS)

    Majidi, Majid; Nojavan, Sayyad; Zare, Kazem

    2017-01-01

    Highlights: • On-grid photovoltaic/battery/fuel cell system is considered as hybrid system. • Thermal and electrical operation of hybrid energy system is studied. • Hybrid energy system is used to reduce dependency on upstream grid for load serving. • Demand response program is proposed to manage the electrical load. • Demand response program is proposed to reduce hybrid energy system’s operation cost. - Abstract: In this paper, cost-efficient operation problem of photovoltaic/battery/fuel cell hybrid energy system has been evaluated in the presence of demand response program. Each load curve has off-peak, mid and peak time periods in which the energy prices are different. Demand response program transfers some amount of load from peak periods to other periods to flatten the load curve and minimize total cost. So, the main goal is to meet the energy demand and propose a cost-efficient approach to minimize system’s total cost including system’s electrical cost and thermal cost and the revenue from exporting power to the upstream grid. A battery has been utilized as an electrical energy storage system and a heat storage tank is used as a thermal energy storage system to save energy in off-peak and mid-peak hours and then supply load in peak hours which leads to reduction of cost. The proposed cost-efficient operation problem of photovoltaic/battery/fuel cell hybrid energy system is modeled by a mixed-integer linear program and solved by General algebraic modeling system optimization software under CPLEX solver. Two case studies are investigated to show the effects of demand response program on reduction of total cost.

  20. A hybrid radial basis function-pseudospectral method for thermal convection in a 3-D spherical shell

    KAUST Repository

    Wright, G. B.

    2010-07-01

    A novel hybrid spectral method that combines radial basis function (RBF) and Chebyshev pseudospectral methods in a "2 + 1" approach is presented for numerically simulating thermal convection in a 3-D spherical shell. This is the first study to apply RBFs to a full 3-D physical model in spherical geometry. In addition to being spectrally accurate, RBFs are not defined in terms of any surface-based coordinate system such as spherical coordinates. As a result, when used in the lateral directions, as in this study, they completely circumvent the pole issue with the further advantage that nodes can be "scattered" over the surface of a sphere. In the radial direction, Chebyshev polynomials are used, which are also spectrally accurate and provide the necessary clustering near the boundaries to resolve boundary layers. Applications of this new hybrid methodology are given to the problem of convection in the Earth\\'s mantle, which is modeled by a Boussinesq fluid at infinite Prandtl number. To see whether this numerical technique warrants further investigation, the study limits itself to an isoviscous mantle. Benchmark comparisons are presented with other currently used mantle convection codes for Rayleigh number (Ra) 7 × 103 and 105. Results from a Ra = 106 simulation are also given. The algorithmic simplicity of the code (mostly due to RBFs) allows it to be written in less than 400 lines of MATLAB and run on a single workstation. We find that our method is very competitive with those currently used in the literature. Copyright 2010 by the American Geophysical Union.

  1. High Density Polyethylene Composites Reinforced with Hybrid Inorganic Fillers: Morphology, Mechanical and Thermal Expansion Performance

    Directory of Open Access Journals (Sweden)

    Birm-June Kim

    2013-09-01

    Full Text Available The effect of individual and combined talc and glass fibers (GFs on mechanical and thermal expansion performance of the filled high density polyethylene (HDPE composites was studied. Several published models were adapted to fit the measured tensile modulus and strength of various composite systems. It was shown that the use of silane-modified GFs had a much larger effect in improving mechanical properties and in reducing linear coefficient of thermal expansion (LCTE values of filled composites, compared with the use of un-modified talc particles due to enhanced bonding to the matrix, larger aspect ratio, and fiber alignment for GFs. Mechanical properties and LCTE values of composites with combined talc and GF fillers varied with talc and GF ratio at a given total filler loading level. The use of a larger portion of GFs in the mix can lead to better composite performance, while the use of talc can help lower the composite costs and increase its recyclability. The use of 30 wt % combined filler seems necessary to control LCTE values of filled HDPE in the data value range generally reported for commercial wood plastic composites. Tensile modulus for talc-filled composite can be predicted with rule of mixture, while a PPA-based model can be used to predict the modulus and strength of GF-filled composites.

  2. High Density Polyethylene Composites Reinforced with Hybrid Inorganic Fillers: Morphology, Mechanical and Thermal Expansion Performance.

    Science.gov (United States)

    Huang, Runzhou; Xu, Xinwu; Lee, Sunyoung; Zhang, Yang; Kim, Birm-June; Wu, Qinglin

    2013-09-17

    The effect of individual and combined talc and glass fibers (GFs) on mechanical and thermal expansion performance of the filled high density polyethylene (HDPE) composites was studied. Several published models were adapted to fit the measured tensile modulus and strength of various composite systems. It was shown that the use of silane-modified GFs had a much larger effect in improving mechanical properties and in reducing linear coefficient of thermal expansion (LCTE) values of filled composites, compared with the use of un-modified talc particles due to enhanced bonding to the matrix, larger aspect ratio, and fiber alignment for GFs. Mechanical properties and LCTE values of composites with combined talc and GF fillers varied with talc and GF ratio at a given total filler loading level. The use of a larger portion of GFs in the mix can lead to better composite performance, while the use of talc can help lower the composite costs and increase its recyclability. The use of 30 wt % combined filler seems necessary to control LCTE values of filled HDPE in the data value range generally reported for commercial wood plastic composites. Tensile modulus for talc-filled composite can be predicted with rule of mixture, while a PPA-based model can be used to predict the modulus and strength of GF-filled composites.

  3. Mechatronics design and experimental verification of an electric-vehicle-based hybrid thermal management system

    Directory of Open Access Journals (Sweden)

    Yi-Hsuan Hung

    2016-02-01

    Full Text Available In this study, an electric-vehicle-based thermal management system was designed for dual energy sources. An experimental platform developed in a previous study was modified. Regarding the mechanical components, a heat exchanger with a radiator, proportional valve, coolant pipes, and coolant pump was appropriately integrated. Regarding the electric components, two heaters emulating waste heat were controlled using two programmable power supply machines. A rapid-prototyping controller with two temperature inputs and three outputs was designed. Rule-based control strategies were coded to maintain optimal temperatures for the emulated proton exchange membrane fuel cells and lithium batteries. To evaluate the heat power of dual energy sources, driving cycles, energy management control, and efficiency maps of energy sources were considered for deriving time-variant values. The main results are as follows: (a an advanced mechatronics platform was constructed; (b a driving cycle simulation was successfully conducted; and (c coolant temperatures reached their optimal operating ranges when the proportional valve, radiator, and coolant pump were sequentially controlled. The benefits of this novel electric-vehicle-based thermal management system are (a high-efficiency operation of energy sources, (b low occupied volume integrated with energy sources, and (c higher electric vehicle traveling mileage. This system will be integrated with real energy sources and a real electric vehicle in the future.

  4. Thermal and electrical performance of a hybrid design of a solar-thermoelectric system

    International Nuclear Information System (INIS)

    Ong, K.S.; Naghavi, M.S.; Lim, Christopher

    2017-01-01

    Highlights: • Hybrid solar-thermoelectric system studied under outdoor conditions. • Electrical output voltage and hot water temperatures peaked around 15.30. • Total electrical efficiency was very low, about 0.16% at around 15.30 h. - Abstract: An evacuated tube heat pipe solar collector was fitted with four thermoelectric modules and four water cooling jackets on the condenser side to produce electricity and hot water simultaneously. Each cooling jacket had six mini water-flow channels inside it. Solar heat was absorbed and collected by the evaporator section. Experiments were conducted under outdoor environment with various water coolant flow rates. Once-through coolant water flow was adopted as a first step. Further investigations would be conducted to incorporate an insulated hot water storage tank to evaluate the system economic viability as a power producer and hot water generator. Temperatures were recorded along the evaporator and condenser sections of the heat pipe, thermoelectric junction temperatures and inlet/outlet water channels. This paper presents the experimental results obtained. Typical daily experimental results showed that electrical output voltage and hot water temperatures peaked around 15.30 before decreasing towards the evening. Total electrical efficiency was very low, about 0.16% at around 15.30 h.

  5. Excitation of upper-hybrid waves by a thermal parametric instability

    International Nuclear Information System (INIS)

    Lee, M.C.; Kuo, S.P.

    1983-01-01

    A purely growing instability characterized by a four-wave interaction is analysed in a uniform, magnetized plasma. Up-shifted and down-shifted upper-hybrid waves and a non-oscillatory mode can be excited by a pump wave of ordinary rather than extraordinary polarization in the case of ionospheric heating. The differential Ohmic heating force dominates over the ponderomotive force as the wave-wave coupling mechanism. The beating current at zero frequency produces a significant stabilizing effect on the excitation of short-scale modes by counterbalancing the destabilizing effect of the differential Ohmic heating. The effect of ionospheric inhomogeneity is estimated, showing a tendency to raise the thresholds of the instability. When applied to ionospheric heating experiments, the present theory can explain the excitation of field-aligned plasma lines and ionospheric irregularities with a continuous spectrum ranging from metre-scale to hundreds of metre-scale. Further, the proposed mechanism may become a competitive process to the parametric decay instability and be responsible for the overshoot phenomena of the plasma line enhancement at Arecibo. (author)

  6. Integration of thermal photovoltaic hybrid sensors to the building. Final report july 2004. Integrated research project 6.2; Integration de capteurs hybrides photovoltaiques thermiques au bati. Rapport final juillet 2004. Projet de recherche integre 6.2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    The electricity and the heat are two complementary energies necessary for the accommodation. A thermal solar installation needs the electric power for the coolant fluid flow. This research project concerns the optimization of integrated solutions to the building, providing simultaneously these two energies. This document presents the proposed researches programs: analysis of the socio-economic aspects, the physical phenomena knowledge, simulation of the behavior, experimentation, hybrid components integration, simulation of the photovoltaic modules operating and thermal simulation of an electric converter. (A.L.B.)

  7. Rapid thermal cycling of new technology solar array blanket coupons

    Science.gov (United States)

    Scheiman, David A.; Smith, Bryan K.; Kurland, Richard M.; Mesch, Hans G.

    1990-01-01

    NASA Lewis Research Center is conducting thermal cycle testing of a new solar array blanket technologies. These technologies include test coupons for Space Station Freedom (SSF) and the advanced photovoltaic solar array (APSA). The objective of this testing is to demonstrate the durability or operational lifetime of the solar array interconnect design and blanket technology within a low earth orbit (LEO) or geosynchronous earth orbit (GEO) thermal cycling environment. Both the SSF and the APSA array survived all rapid thermal cycling with little or no degradation in peak performance. This testing includes an equivalent of 15 years in LEO for SSF test coupons and 30 years of GEO plus ten years of LEO for the APSA test coupon. It is concluded that both the parallel gap welding of the SSF interconnects and the soldering of the APSA interconnects are adequately designed to handle the thermal stresses of space environment temperature extremes.

  8. Ultrapure hydrogen thermal compressor based on metal hydrides for fuel cells and hybrid vehicles

    International Nuclear Information System (INIS)

    Almasan, V.; Biris, A.; Coldea, I.; Lupu, D.; Misan, I.; Popeneciu, G.; Ardelean, O.

    2007-01-01

    Full text: In hydrogen economy, efficient compressors are indispensable elements in the storage, transport and distribution of the produced hydrogen. Energetic efficient technologies can contribute to H 2 pipelines transport to the point of use and to distribute H 2 by refuelling stations. Characteristic for metal hydrides systems is the wide area of possibilities to absorb hydrogen at low pressure from any source of hydrogen, to store and deliver it hydrogen at high pressure (compression ratio more than 30). On the basis of innovative concepts and advanced materials for H 2 storage/compression (and fast thermal transfer), a fast mass (H 2 ) and heat transfer unit will be developed suitable to be integrated in a 3 stage thermal compressor. Metal hydrides used for a three stage hydrogen compression system must have different equilibrium pressures, namely: for stage 1, low pressure H 2 absorption and resistant to poisoning with impurities of hydrogen, for stage 2, medium pressure H 2 absorption and for stage 3, high pressure hydrogen delivery (120 bar). In the case of compression device based on metallic hydrides the most important properties are the hydrogen absorption/desorption rate, a smaller process enthalpy and a great structural stability on long term hydrogen absorption/desorption cycling. These properties require metal hydrides with large differences between the hydrogen absorption and desorption pressures at equilibrium, within a rather small temperature range. The main goal of this work is to search and develop metal hydride integrated systems for hydrogen purification, storage and compression. After a careful screening three hydrogen absorbing alloys will be selected. After selection, the work up of the alloys composition on the bases of detailed solid state studies, new multi-component alloys will be developed, with suitable thermodynamic and kinetic properties for a hydrogen compressor. The results of the study are the following: new types of hydrogen

  9. Reactivity changes in hybrid thermal-fast reactor systems during fast core flooding

    International Nuclear Information System (INIS)

    Pesic, M.

    1994-09-01

    A new space-dependent kinetic model in adiabatic approximation with local feedback reactivity parameters for reactivity determination in the coupled systems is proposed in this thesis. It is applied in the accident calculation of the 'HERBE' fast-thermal reactor system and compared to usual point kinetics model with core-averaged parameters. Advantages of the new model - more realistic picture of the reactor kinetics and dynamics during local large reactivity perturbation, under the same heat transfer conditions, are underlined. Calculated reactivity parameters of the new model are verified in the experiments performed at the 'HERBE' coupled core. The model has shown that the 'HERBE' safety system can shutdown reactor safely and fast even in the case of highly set power trip and even under conditions of big partial failure of the reactor safety system (author)

  10. Characteristics and thermal behavior analysis of lithium-ion batteries for application in hybrid locomotives

    Science.gov (United States)

    Chatterjee, Krishnashis

    The locomotive industry accounts for 2.5 % of the total fuel consumption in the US. Thus the necessity for reducing fuel consumption and emissions led to the development of the concept of hybrid locomotive which is dual powered by the diesel engine and electric motors. But the energy dissipated in braking such a locomotive in a year is enough to power over 9100 average US households over the same period of time. Recovering this energy using regenerative braking system and storing it in a electric battery is of great interest among researchers for improving overall efficiency and reducing consumption of fuels. In the present study, LiFePO4 batteries, a type of the state-of-art lithium-ion batteries, have been tested under different environmental and load conditions. Environmental temperatures were varied to analyze their effects on the charging and discharging patterns of the battery by using the CADEX battery analyzer in order to find the temperature range for optimum battery performance. The fluctuations of temperature of the battery surface were monitored along the length of the tests, using Infra-Red imaging and thermocouple probes at different points on the battery surface. Both battery performance characteristics and the variation of the battery surface temperature were also recorded for different load cycles in order to get a comprehensive picture of the heat generation and its effect on the behavior of the battery under different load conditions. Lastly a practical Load Cycle analysis of the battery has been performed which gave a picture of the heat generated by the battery and also the performance characteristics as it is subjected to a practical Load Cycle.

  11. Development of a hybrid MSGC detector for thermal neutron imaging with a MHz data acquisition and histogramming system

    CERN Document Server

    Gebauer, B; Richter, G; Levchanovsky, F V; Nikiforov, A

    2001-01-01

    For thermal neutron imaging at the next generation of high-flux pulsed neutron sources a large area and fourfold segmented, hybrid, low-pressure, two-dimensional position sensitive, microstrip gas chamber detector, fabricated in a multilayer technology on glass substrates, is presently being developed, which utilizes a thin composite sup 1 sup 5 sup 7 Gd/CsI neutron converter. The present article focusses on the readout scheme and the data acquisition (DAQ) system. For position encoding, interpolating and fast multihit delay line based electronics is applied with up to eightfold sub-segmentation per geometrical detector segment. All signals, i.e. position, time-of-flight and pulse-height signals, are fed into deadtime-less 8-channel multihit TDC chips with 120 ps LSB via constant fraction and time-over-threshold discriminators, respectively. The multihit capability is utilized to raise the count rate limit in combination with a sum check algorithm for disentangling pulses from different events. The first vers...

  12. Room temperature synthesis of an optically and thermally responsive hybrid PNIPAM-gold nanoparticle

    International Nuclear Information System (INIS)

    Morones, J. Ruben; Frey, Wolfgang

    2010-01-01

    Composites of metal nanoparticles and environmentally sensitive polymers are useful as nanoactuators that can be triggered externally using light of a particular wavelength. We demonstrate a synthesis route that is easier than grafting techniques and allows for the in situ formation of individual gold nanoparticles encapsulated by an environmentally sensitive polymer, while also providing a strong interaction between the polymer and the metal particle. We present a one-pot, room-temperature synthesis route for gold metal nanoparticles that uses poly-N-isopropyl acrylamide as the capping and stabilizing agent and ascorbic acid as the reducing agent and achieves size control similar to the most common citric acid synthesis. We show that the composite can be precipitated reversibly by temperature or light using the non-radiative decay and conversion to heat of the surface plasmon resonance of the metal nanoparticle. The precipitation is induced by the collapse of the polymer cocoon surrounding each gold nanoparticle, as can be seen by surface plasmon spectroscopy. The experiments agree with theoretical models for the heat generation in a colloidal suspension that support fast switching with low laser power densities. The synthesized composite is a simple nanosized opto-thermal switch.

  13. Efficient electrocatalytic performance of thermally exfoliated reduced graphene oxide-Pt hybrid

    Energy Technology Data Exchange (ETDEWEB)

    Antony, Rajini P., E-mail: raji.anna@gmail.com; Preethi, L.K.; Gupta, Bhavana; Mathews, Tom, E-mail: tom@igcar.gov.in; Dash, S.; Tyagi, A.K.

    2015-10-15

    Highlights: • Synthesis of Pt–RGO nanohybrids of very high electrochemically active surface area. • Electrocatalytic activity-cum-stability: ∼10 times that of commercial Pt-C catalyst. • TEM confirms narrow size distribution and excellent dispersion of Pt nanoparticles. • SAED and XRD indicate (1 1 1) orientation of Pt nanoparticles. • Methanol oxidation EIS reveal decrease in charge transfer resistance with potential - Abstract: High quality thermally exfoliated reduced graphene oxide (RGO) nanosheets decorated with platinum nanocrystals have been synthesized using a simple environmentally benign process. The electrocatalytic behaviour of the Pt–RGO nanohybrid for methanol oxidation was studied using cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. High resolution transmission electron microscopy shows uniform dispersion of Pt nanoparticles of ∼2–4 nm size. X-ray diffraction and selected area diffraction studies reveal (1 1 1) orientation of the platinum nanoparticles. The cyclic voltammetry and chronoamperometry results indicate higher catalytic activity and stability for Pt–RGO compared to commercial Pt-C. The electrochemical active surface area of Pt–RGO (52.16 m{sup 2}/g) is found to be 1.5 times that of commercial Pt-C. Impedance spectroscopy shows different impedance behaviour at different potential regions, indicating change in methanol oxidation reaction mechanism with potential. The reversal of impedance pattern to the second quadrant, at potentials higher than ∼0.40 V, indicates change in the rate determining reaction.

  14. Evaluating the thermal damage resistance of graphene/carbon nanotube hybrid composite coatings

    Science.gov (United States)

    David, L.; Feldman, A.; Mansfield, E.; Lehman, J.; Singh, G.

    2014-03-01

    We study laser irradiation behavior of multiwalled carbon nanotubes (MWCNT) and chemically modified graphene (rGO)-composite spray coatings for use as a thermal absorber material for high-power laser calorimeters. Spray coatings on aluminum test coupon were exposed to increasing laser irradiance for extended exposure times to quantify their damage threshold and optical absorbance. The coatings, prepared at varying mass % of MWCNTs in rGO, demonstrated significantly higher damage threshold values at 2.5 kW laser power at 10.6 μm wavelength than carbon paint or MWCNTs alone. Electron microscopy and Raman spectroscopy of irradiated specimens show that the coating prepared at 50% CNT loading endure at least 2 kW.cm-2 for 10 seconds without significant damage. The improved damage resistance is attributed to the unique structure of the composite in which the MWCNTs act as an efficient absorber of laser light while the much larger rGO sheets surrounding them, dissipate the heat over a wider area.

  15. Optimum Dispatch of Hybrid Solar Thermal (HSTP Electric Power Plant Using Non-Smooth Cost Function and Emission Function for IEEE-30 Bus System

    Directory of Open Access Journals (Sweden)

    Saroj Kumar Dash

    2016-07-01

    Full Text Available The basic objective of economic load dispatch (ELD is to optimize the total fuel cost of hybrid solar thermal electric power plant (HSTP. In ELD problems the cost function for each generator has been approximated by a single quadratic cost equation. As cost of coal increases, it becomes even more important have a good model for the production cost of each generator for the solar thermal hybrid system. A more accurate formulation is obtained for the ELD problem by expressing the generation cost function as a piece wise quadratic cost function. However, the solution methods for ELD problem with piece wise quadratic cost function requires much complicated algorithms such as the hierarchical structure approach along with evolutionary computations (ECs. A test system comprising of 10 units with 29 different fuel [7] cost equations is considered in this paper. The applied genetic algorithm method will provide optimal solution for the given load demand.

  16. A IR-Femtosecond Laser Hybrid Sensor to Measure the Thermal Expansion and Thermo-Optical Coefficient of Silica-Based FBG at High Temperatures.

    Science.gov (United States)

    Li, Litong; Lv, Dajuan; Yang, Minghong; Xiong, Liangming; Luo, Jie

    2018-01-26

    In this paper, a hybrid sensor was fabricated using a IR-femtosecond laser to measure the thermal expansion and thermo-optical coefficient of silica-based fiber Bragg gratings (FBGs). The hybrid sensor was composed of an inline fiber Fabry-Perot interferometer (FFPI) cavity and a type-II FBG. Experiment results showed that the type-II FBG had three high reflectivity resonances in the wavelength ranging from 1100 to 1600 nm, showing the peaks in 1.1, 1.3 and 1.5 μm, respectively. The thermal expansion and thermo-optical coefficient (1.3 μm, 1.5 μm) of silica-based FBG, under temperatures ranging from 30 to 1100 °C, had been simultaneously calculated by measuring the wavelength of the type-II FBG and FFPI cavity length.

  17. Study of the heat transfers spectral radiation - conduction - natural convection in hybrid photovoltaic systems for buildings

    International Nuclear Information System (INIS)

    Muresan, C.

    2005-01-01

    The present work is supported by the CSTB and the ADEME and is a part of an Integrated Research Project - Energy Program of CNRS - (http://www.imp.cnrs.fr/energie/) coordinated by the CETHIL: 'Integration of hybrid Thermal - Photovoltaic solar collector in buildings'. In this context, this thesis represents upstream studies led in the I.R.P., pursuing the study itself of these hybrid components in stage of integration to the framework of buildings (thermal/electric management in response to the needs). Its objective falls under an action to identify and look further into knowledge of the limiting factors of the efficiency of these hybrid components (the operating temperature of the photosensitive cells), to identify the enduring scientific bolts persisting and to contribute to removing them. To reach this aim, predictive numerical tools are developed in order to guide and follow the future evolutions of these active wall elements. The problems related to the Photovoltaic components of Mono or Poly crystalline type, namely the risk of heating of the modules included within the built framework that can lead to a degradation of their energy efficiency. The developed model aims at obtaining the evaluation of the internal field of temperature. The modeling of the radiative behavior of multi-layer components of not scattering semi-transparent media is carried out. Propagation of a collimated flux corresponds to the direct solar radiation, and a diffuse flux represents the solar radiation diffused and that resulting from the other external sources (environment). Both are treated in a separate way. The incidental radiation power and radiative net flux are thus evaluated by a superposition of the values obtained at the time of the separate studies of the two components. The collimated component of incidental flux is treated according to an approach of 'ray tracing' type. The Discrete Ordinates Method (DOM) associated to the method of finite volumes, is employed for the

  18. A study of photovoltaic/thermal (PVT)-ground source heat pump hybrid system by using fuzzy logic control

    International Nuclear Information System (INIS)

    Andrew Putrayudha, S.; Kang, Eun Chul; Evgueniy, E.; Libing, Y.; Lee, Euy Joon

    2015-01-01

    Renewable Heat Obligation (RHO) implementation in every country becomes an important issue to utilize more renewable energy sources while reducing the usage of fossil fuel. In 2014, South Korea has a target that every commercial building construction that exceeding 10,000 m 2 has to have on-site new & renewable power generation such as combined heat in the beginning of 2016. Photovoltaic/Thermal (PVT) and Geothermal hybrid systems have been introduced in previous research (E.J. Lee et al.) and it showed a great result from its efficiency and also its power consumption for single and multi-building cases. In this paper, Fuzzy Logic control has been applied to optimize the energy consumption of the system. By comparing it with conventional on–off control, fuzzy logic control system shows a better result in reducing primary energy consumption for both heating and cooling systems annually. Two cases were introduced in this paper, GSHP system and PVT–GSHP system with both on–off and fuzzy logic applied respectively. As a result, it shows that fuzzy logic control consumed 13.3% less energy compared with on–off controller for GSHP system annually and 18.3% less energy compared to on–off controller for PVT–GSHP system annually. - Highlights: • Two renewable systems were designed to produce heating, cooling and electricity. • System optimization by applying Fuzzy Logic in terms of energy saving. • Conventional on–off control system vs advance fuzzy logic control system. • Assumption used based on previous research experience, guidelines.

  19. Simple synthesis of Al{sub 2}O{sub 3} sphere composite from hybrid process with improved thermal stability for catalytic applications

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Regina C.R., E-mail: reginaclaudiasantos@yahoo.com.br [Department of Analytical Chemistry and Physical Chemistry, Federal University of Ceará, Campus of Pici, Fortaleza, CE, CEP: 60440-554 (Brazil); Pinheiro, Antônio N.; Leite, Edson R. [Department of Chemistry, Federal University of São Carlos, São Carlos, SP, CEP: 13560-905 (Brazil); Freire, Valder N. [Department of Physics, Federal University of Ceará, Campus of Pici, Fortaleza, CE, CEP: 60440-554 (Brazil); Longhinotti, Elisane; Valentini, Antoninho [Department of Analytical Chemistry and Physical Chemistry, Federal University of Ceará, Campus of Pici, Fortaleza, CE, CEP: 60440-554 (Brazil)

    2015-06-15

    Aluminium oxide spheres were synthesized by the hybrid process applying the biopolymer chitosan. After the calcination process the porous spheres were characterized by Chemical elemental analysis (XRF), X-ray diffraction (XRD), Scanning electron microscopy and Energy Dispersive X-ray Spectroscopy (SEM-EDS), N{sub 2} adsorption–desorption isotherms, infrared spectroscopy (IR), and CO{sub 2} temperature programmed desorption (CO{sub 2}-TPD). The effect of thermal treatment on surface properties of the oxide spheres was also evaluated by the catalytic ethanol dehydration reaction. The hybrid method produced interesting results related to the thermal stability against sintering process and consequently low decreases of surface area. The hybrid spheres calcination at 900 and 1200 °C produced a metastable phases of alumina with a high surface area, and nanometric crystallites. Additionally, the spheres of mixed silica-alumina synthesized by this method reveal the formation of porous spheres with highly acidic OH groups, which was suggested by the catalytic performance. - Highlights: • Al and Si/Al oxide spheres with promising properties are synthesized by hybrid method. • Al{sub 2}O{sub 3} spheres show high thermal stability and resistance the loss surface area. • The SiO{sub 2} addition plays an important role in the structure and porosity of the spheres. • Al{sub 2}O{sub 3} and SiO{sub 2}/Al{sub 2}O{sub 3} spheres presented a good activity to conversion ethanol. • The activity is related to the surface area and density of OH groups on surface.

  20. X-ray scattering study of thermal nanopore templating in hybrid films of organosilicate precursor and reactive four-armed porogen

    International Nuclear Information System (INIS)

    Yoon, Jinhwan; Heo, Kyuyoung; Oh, Weontae; Jin, Kyeong Sik; Jin, Sangwoo; Kim, Jehan; Kim, Kwang-Woo; Chang, Taihyun; Ree, Moonhor

    2006-01-01

    The miscibility and the mechanism for thermal nanopore templating in films prepared from spin-coating and subsequent drying of homogenous solutions of curable polymethylsilsesquioxane dielectric precursor and thermally labile, reactive triethoxysilyl-terminated four-armed poly(ε-caprolactone) porogen were investigated in detail by in situ two-dimensional grazing incidence small-angle x-ray scattering analysis. The dielectric precursor and porogen components in the film were fully miscible. On heating, limited aggregations of the porogen, however, took place in only a small temperature range of 100-140 deg. C as a result of phase separation induced by the competition of the curing and hybridization reactions of the dielectric precursor and porogen; higher porogen loading resulted in relatively large porogen aggregates and a greater size distribution. The developed porogen aggregates underwent thermal firing above 300 deg. C without further growth and movement, and ultimately left their individual footprints in the film as spherical nanopores

  1. Novel double-stage high-concentrated solar hybrid photovoltaic/thermal (PV/T) collector with nonimaging optics and GaAs solar cells reflector

    International Nuclear Information System (INIS)

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

    2016-01-01

    Highlights: • A novel hybrid concentrating photovoltaic thermal (PV/T) collector is developed. • Thermal component achieves 60× concentration using nonimaging optics. • GaAs solar cells used as spectrally selective mirrors for low energy photons. • Thermal efficiencies of 37% at 365 °C and electrical efficiencies of 8% achieved. • Combined electric efficiency reaches 25% of DNI for system cost of $283.10/m"2". - Abstract: A novel double stage high-concentration hybrid solar photovoltaic thermal (PV/T) collector using nonimaging optics and world record thin film single-junction gallium arsenide (GaAs) solar cells has been developed. We present a detailed design and simulation of the system, experimental setup, prototype, system performance, and economic analysis. The system uses a parabolic trough (primary concentrator) to focus sunlight towards a secondary nonimaging compound parabolic concentrator (CPC) to simultaneously generate electricity from single junction GaAs solar cells, as well as high temperature dispatchable heat. This study is novel in that (a) the solar cells inside the vacuum tube act as spectrally selective mirrors for lower energy photons to maximize the system exergy, and (b) secondary concentrator allows the thermal component to reach a concentration ratio ∼60×, which is significantly higher than conventional PV/T concentration ratios. The maximum outlet temperature reached was 365 °C, and on average the thermal efficiency of the experiment was around 37%. The maximum electrical efficiency was around 8%. The total system electricity generation is around 25% of incoming DNI, by assuming the high temperature stream is used to power a steam turbine. The installed system cost per unit of parabolic trough aperture area is $283.10 per m"2.

  2. Characterization of thermal destruction behavior of hybrid composites based on polyoxymethylene, ethylene-octene copolymer impact modifier and ZnO nanofiller

    Energy Technology Data Exchange (ETDEWEB)

    Meri, Remo Merijs; Zicans, Janis; Abele, Agnese; Ivanova, Tatjana; Kalnins, Martins [Riga Technical University, Faculty of Materials Science and Applied Chemistry, Institute of Polymer Materials, Paula Valdena street 3/7, Riga, LV-1048 (Latvia)

    2016-05-18

    Hybrid polymer nanocomposites, composed of polyoxymethylene (POM), ethylene octene copolymer (EOC) and plasma synthesized tetrapod shaped zinc oxide (ZnO), were prepared by using melt compounding. The content of EOC in the POM based composites was varied between 10 and 50 mass %, while the content of ZnO was constant (2 mass %). Thermal behaviour of POM based systems was studied by using thermogravimetric analysis coupled with Fourier transform infrared spectroscopy. The influence of the elastomer content and/or ZnO addition on the thermal stability of POM based systems was evaluated. The influence of the α-octene content in the elastomer on the thermal decomposition behaviour of POM and its nanocomposites with ZnO was also evaluated. Results of thermogravimetric analysis showed that, by rising either the elastomer or ZnO content, thermal stability of the investigated POM composites was increased. The modifying effect of EOC17 in respect of thermal resistance was somewhat larger than that of EOC38 because of the smaller amount of tertiary carbon atoms in the macromolecular structure of the former elastomer. Improved thermal resistance of ZnO containing POM based composites was because of impermeable structure the inorganic nanofiller allowing decrease gas exchange rate and facilitating non-combustible gases, such as CO{sub 2}, stay in the zone of burning. Addition of ZnO have a potential to influence structure of the polymer blend matrix itself by improving its barrier characteristics.

  3. Thermal conductivity and viscosity of hybrid nanfluids prepared with magnetic nanodiamond-cobalt oxide (ND-Co3O4 nanocomposite

    Directory of Open Access Journals (Sweden)

    L. Syam Sundar

    2016-03-01

    Full Text Available Synthesis of magnetic nanodiamond-cobalt oxide (ND-Co3O4 nanocomposite material; preparation of nanofluids and estimation of thermal properties such as thermal conductivity and viscosity has been explained experimentally in this paper. The nanocomposite material has been synthesized by using in-situ growth technique and chemical coprecipitation between cobalt chloride and sodium borohydrate. The various techniques such as XRD, TEM, XPS and VSM have been used to confirm the ND and Co3O4 phase of synthesized nanocomposite. The hybrid nanofluids have been prepared by dispersing synthesized ND-Co3O4 nanocomposite in water, ethylene glycol/water mixtures. The thermal properties such as thermal conductivity and viscosity have been measured experimentally at different weight concentrations and temperatures. The results reveal that the thermal conductivity enhancements are about 16%, 9%, 14%, 11% and 10% for water, EG, 20:80%, 40:60%, and 60:40% EG/W based nanofluids at 0.15 wt% concentrations and at 60 °C respectively. Similarly the viscosity enhancements are about 1.45-times, 1.46-times, 1.15-times, 1.19-times, and 1.51-times for water, EG, 20:80%, 40:60%, and 60:40% EG/W based nanofluids at 0.15 wt% concentrations and at 60 °C respectively. Based on the experimental data new correlations for thermal conductivity and viscosity have been developed.

  4. Effect of heat-insulating wall on input energy of a photovoltaic/solar/air-heat system for a residence; Jutaku no kodannetsuka ni yoru taiyoko netsu/taiki netsu system no donyu energy sakugen koka

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-10-27

    A proposal was made to introduce a photovoltaic/solar/air-heat system which positively utilizes natural energy in order to curtail consumption of fossil energy, corroborating that the system has greatly reduced energy input in the primary energy level in a house. This paper examines the effect of curtailment of energy input in the case of reducing the load of air conditioning through the high heat insulation of a house. The energy input was evaluated by calculating additional equipment energy needed newly for the high heat insulation. The system performance and the energy load varied greatly depending on weather conditions. The subject system consisted of solar cells, inverter, heat concentrator, heat storage tank, heat pump and gas hot-water supply device. The thickening of the insulation sharply reduced heating load in the house, thereby decreasing fuel energy substantially. An insulation material of 100mm thick was capable of reducing energy input by 16-23% compared with that of 50mm thick. 5 refs., 5 figs, 3 tabs.

  5. Simulation of the thermal performance of a hybrid solar-assisted ground-source heat pump system in a school building

    Science.gov (United States)

    Androulakis, N. D.; Armen, K. G.; Bozis, D. A.; Papakostas, K. T.

    2018-04-01

    A hybrid solar-assisted ground-source heat pump (SAGSHP) system was designed, in the frame of an energy upgrade study, to serve as a heating system in a school building in Greece. The main scope of this study was to examine techniques to reduce the capacity of the heating equipment and to keep the primary energy consumption low. Simulations of the thermal performance of both the building and of five different heating system configurations were performed by using the TRNSYS software. The results are presented in this work and show that the hybrid SAGSHP system displays the lower primary energy consumption among the systems examined. A conventional ground-source heat pump system has the same primary energy consumption, while the heat pump's capacity is double and the ground heat exchanger 2.5 times longer. This work also highlights the contribution of simulation tools to the design of complex heating systems with renewable energy sources.

  6. Effect of Hybrid Talc-Basalt Fillers in the Shell Layer on Thermal and Mechanical Performance of Co-Extruded Wood Plastic Composites.

    Science.gov (United States)

    Huang, Runzhou; Mei, Changtong; Xu, Xinwu; Kärki, Timo; Lee, Sunyoung; Wu, Qinglin

    2015-12-08

    Hybrid basalt fiber (BF) and Talc filled high density polyethylene (HDPE) and co-extruded wood-plastic composites (WPCs) with different BF/Talc/HDPE composition levels in the shell were prepared and their mechanical, morphological and thermal properties were characterized. Incorporating BFs into the HDPE-Talc composite substantially enhanced the thermal expansion property, flexural, tensile and dynamic modulus without causing a significant decrease in the tensile and impact strength of the composites. Strain energy estimation suggested positive and better interfacial interactions of HDPE with BFs than that with talc. The co-extruded structure design improved the mechanical properties of WPC due to the protective shell layer. The composite flexural and impact strength properties increased, and the thermal expansion decreased as BF content increased in the hybrid BF/Talc filled shells. The cone calorimetry data demonstrated that flame resistance of co-extruded WPCs was improved with the use of combined fillers in the shell layer, especially with increased loading of BFs. The combined shell filler system with BFs and Talc could offer a balance between cost and performance for co-extruded WPCs.

  7. Plug-in hybrid electric vehicle LiFePO4 battery life implications of thermal management, driving conditions, and regional climate

    Science.gov (United States)

    Yuksel, Tugce; Litster, Shawn; Viswanathan, Venkatasubramanian; Michalek, Jeremy J.

    2017-01-01

    Battery degradation strongly depends on temperature, and many plug-in electric vehicle applications employ thermal management strategies to extend battery life. The effectiveness of thermal management depends on the design of the thermal management system as well as the battery chemistry, cell and pack design, vehicle system characteristics, and operating conditions. We model a plug-in hybrid electric vehicle with an air-cooled battery pack composed of cylindrical LiFePO4/graphite cells and simulate the effect of thermal management, driving conditions, regional climate, and vehicle system design on battery life. We estimate that in the absence of thermal management, aggressive driving can cut battery life by two thirds; a blended gas/electric-operation control strategy can quadruple battery life relative to an all-electric control strategy; larger battery packs can extend life by an order of magnitude relative to small packs used for all-electric operation; and batteries last 73-94% longer in mild-weather San Francisco than in hot Phoenix. Air cooling can increase battery life by a factor of 1.5-6, depending on regional climate and driving patterns. End of life criteria has a substantial effect on battery life estimates.

  8. Recent developments in thermally-driven seawater desalination: Energy efficiency improvement by hybridization of the MED and AD cycles

    KAUST Repository

    Ng, Kim Choon; Thu, Kyaw; Oh, Seungjin; Ang, Li; Shahzad, Muhammad Wakil; Ismail, Azhar Bin

    2015-01-01

    -driven to adsorption desalination (AD) cycles where significant thermodynamic synergy can be attained when cycles are combined. For these hybrid cycles, a quantum improvement in energy efficiency as well as in increase in water production can be expected. The advent

  9. Review on the Recent Developments of Photovoltaic Thermal (PV/T and Proton Exchange Membrane Fuel Cell (PEMFC Based Hybrid System

    Directory of Open Access Journals (Sweden)

    Zulkepli Afzam

    2016-01-01

    Full Text Available Photovoltaic Thermal (PV/T system emerged as one of the convenient type of renewable energy system acquire the ability to generate power and thermal energy in the absence of moving parts. However, the power output of PV/T is intermittent due to dependency on solar irradiation condition. Furthermore, its efficiency decreases because of cells instability at high temperature. On the other hand, fuel cell co-generation system (CGS is another technology that can generate power and heat simultaneously. Integration of PV/T and fuel cell CGS could enhance the reliability and sustainability of both systems as well as increasing the overall system performance. Hence, this paper intended to present the parameters that affect performance of PV/T and Proton Exchange Membrane Fuel Cell (PEMFC CGS. Moreover, recent developments on PV/T-fuel cell hybrid system are also presented. Based on literates, mass flow rate of moving fluid in PV/T was found to affect the system efficiency. For the PEMFC, when the heat is utilized, the system performance can be increased where the heat efficiency is similar to electrical efficiency which is about 50%. Recent developments of hybrid PV/T and fuel cell show that most of the studies only focus on the power generation of the system. There are less study on the both power and heat utilization which is indeed necessary in future development in term of operation strategy, optimization of size, and operation algorithm.

  10. Integration of photovoltaic solar panels in residential buildings and its contribution in a power feeder of a mixed urban region; Integracao de paineis solares fotovoltaicos em edificacoes residenciais e sua contribuicao em um alimentador de energia de zona urbana mista

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Isis Portolan dos

    2009-02-15

    Energy generation is one of the main pollution sources in the world. Photovoltaic solar energy is a way to guarantee the electric energy generation using a clean and renewable source, the sun. With the photovoltaic modules integration in buildings, it is possible to generate energy in urban areas, using areas already constructed and also minimizing the energy loss with transmission and distribution. Direct connection of a photovoltaic system to the electric grid avoids the necessity of a storage system, and allows the generated energy to be used by any consumer connected to the grid. This thesis proposes the creation and propagation of predefined kits including photovoltaic modules and other equipment, in order to complete installation and connection of photovoltaic generator, resulting in solar roofs in urban houses. The kits could be installed on roofs of existent residences or in new ones, making the installation easier and minimizing the necessity and the costs of a specific project for each case. With the definition of standard components, like the modules, inverters, and others equipment, there would be an industrial production scale, minimizing costs. In addition, the kits also make the training of the installers easier. The simulation of this concept in a residential area in Florianopolis, demonstrates that there is enough area in the roofs to locate one kit in all residences, and that this generation is able to contribute to the energy demand of the area. So all energy generated by the kits will be immediately consumed inside the area, relieving the concessionaire load. His argue that kits can be an interesting way of bringing this energy generation technology to mainstream. (author)

  11. Hybrid Optical Devices: The Case of the Unification of the Electrochromic Device and the Organic Solar Cell

    Directory of Open Access Journals (Sweden)

    Andre F. S. Guedes

    2016-06-01

    Full Text Available The development of Hybrid Optical Devices, using some flexible optically transparent substrate material and organic semiconductor materials, has been widely utilized by the organic electronic industry, when manufacturing new technological products. The Hybrid Optical Device is constituted by the union of the electrochromic device and the organic solar cell. The flexible organic photovoltaic solar cells, in this hybrid optical device, have been the Poly base (3-hexyl thiophene, P3HT, Phenyl-C61-butyric acid methyl ester, PCBM and Polyaniline, PANI, all being deposited in Indium Tin Oxide, ITO. In addition, the thin film, obtained by the deposition of PANI, and prepared in perchloric acid solution, has been identified through PANI-X1. In the flexible electrochromic device, the Poly base (3,4-ethylenedioxythiophene, PEDOT, has been prepared in Propylene Carbonate, PC, being deposited in Indium Tin Oxide, ITO. Also, both devices have been united by an electrolyte solution prepared with Vanadium Pentoxide, V2O5, Lithium Perchlorate, LiClO4, and Polymethylmethacrylate, PMMA. This device has been characterized through Electrical Measurements, such as UV-Vis Spectroscopy and Scanning Electron Microscopy (SEM. Thus, the result obtained through electrical measurements has demonstrated that the flexible organic photovoltaic solar cell presented the characteristic curve of standard solar cell after spin-coating and electrodeposition. Accordingly, the results obtained with optical and electrical characterization have revealed that the electrochromic device demonstrated some change in optical absorption, when subjected to some voltage difference. Moreover, the inclusion of the V2O5/PANI-X1 layer reduced the effects of degradation that this hybrid organic device caused, that is, solar irradiation. Studies on Scanning Electron Microscopy (SEM have found out that the surface of V2O5/PANI-X1 layers can be strongly conditioned by the surface morphology of the

  12. Design and energetical feasibility study of a refrigerated trailer with photovoltaic solar energy; Diseno y estudio de viabilidad energetica de un trailer refrigerado mediante energia solar fotovoltaica

    Energy Technology Data Exchange (ETDEWEB)

    Callen, S.; Ibanez, M.; Cabeza, L. F.

    2004-07-01

    In this study we have tried to show the energetic viability and the design of a refrigerated trailer, in which it has changed the traditional oil generator from the refrigeration system to a photovoltaic generator. Due to restrictions of design limited by trailer dimensions and the horizontal positions of modules, as one of the first conclusion has been necessary to reduce the refrigeration charge, to obtain the necessary energy savings to have technical viability of the project. The propositions to get the energy savings are to improve the thermal insulation of the trailer and to limit the kind and amount of products to transport. Finally, to apply the technology of solar refrigeration in the cooling unit of the trailer to optimise its performance. (Author)

  13. A novel integrated thermal-/membrane-based solar energy-driven hybrid desalination system: Concept description and simulation results

    KAUST Repository

    Kim, Youngdeuk; Thu, Kyaw; Ng, Kim Choon; Amy, Gary L.; Ghaffour, NorEddine

    2016-01-01

    water production and water recovery ratio of a solar-assisted 24-stage VMD-AD hybrid system are found to be about 21% and 23% higher, respectively, as compared to the VMD-only system. For the solar-assisted 24-stage VMD-AD desalination system having 150

  14. Thermal, Mechanical and UV-Shielding Properties of Poly(Methyl Methacrylate/Cerium Dioxide Hybrid Systems Obtained by Melt Compounding

    Directory of Open Access Journals (Sweden)

    María A. Reyes-Acosta

    2015-09-01

    Full Text Available Thick and homogeneous hybrid film systems based on poly(methyl methacrylate (PMMA and CeO2 nanoparticles were synthesized using the melt compounding method to improve thermal stability, mechanical and UV-shielding properties, as well as to propose them for use in the multifunctional materials industry. The effect of the inorganic phase on these properties was assessed by using two different weight percentages of synthesized CeO2 nanoparticles (0.5 and 1.0 wt % with the sol–gel method and thermal treatment at different temperatures (120, 235, 400, 600 and 800 °C. Thereafter, the nanoceria powders were added to the polymer matrix by single screw extrusion. The absorption in the UV region was increased with the crystallite size of the CeO2 nanoparticles and the PMMA/CeO2 weight ratio. Due to the crystallinity of CeO2 nanoparticles, the thermal, mechanical and UV-shielding properties of the PMMA matrix were improved. The presence of CeO2 nanostructures exerts an influence on the mobility of PMMA chain segments, leading to a different glass transition temperature.

  15. A new hybrid ocean thermal energy conversion–Offshore solar pond (OTEC–OSP) design: a cost optimization approach

    NARCIS (Netherlands)

    Straatman, P.J.T.; van Sark, W.G.J.H.M.

    2008-01-01

    Solar thermal electricity (STE) generation offers an excellent opportunity to supply electricity with a non-CO2 emitting technology. However, present costs hamper widespread deployment and therefore research and development efforts are concentrated on accelerated cost reductions and efficiency

  16. Hybrid PV and solar-thermal systems for domestic heat and power provision in the UK: Techno-economic considerations

    International Nuclear Information System (INIS)

    Herrando, María; Markides, Christos N.

    2016-01-01

    Highlights: • Renewable heat and power generation in UK homes with PVT systems studied. • PVT/w generation: 2.3 MW_e h/yr (51% of demand) and 1.0 MW_t_h h/yr (36% hot water). • Optimised PVT/w system has 9–11 year payback periods (PV-only: 6.8 years). • Same system allows 16.0-t CO_2 reduction and 14-t primary fossil-fuel saving. • With a ∼2:1 support (£/W_e h:£/W_t_h h), PVT and PV have similar payback periods. - Abstract: A techno-economic analysis is undertaken to assess hybrid PV/solar-thermal (PVT) systems for distributed electricity and hot-water provision in a typical house in London, UK. In earlier work (Herrando et al., 2014), a system model based on a PVT collector with water as the cooling medium (PVT/w) was used to estimate average year-long system performance. The results showed that for low solar irradiance levels and low ambient temperatures, such as those associated with the UK climate, a higher coverage of total household energy demands and higher CO_2 emission savings can be achieved by the complete coverage of the solar collector with PV and a relatively low collector cooling flow-rate. Such a PVT/w system demonstrated an annual electricity generation of 2.3 MW h, or a 51% coverage of the household’s electrical demand (compared to an equivalent PV-only value of 49%), plus a significant annual water heating potential of to 1.0 MW h, or a 36% coverage of the hot-water demand. In addition, this system allowed for a reduction in CO_2 emissions amounting to 16.0 tonnes over a life-time of 20 years due to the reduction in electrical power drawn from the grid and gas taken from the mains for water heating, and a 14-tonne corresponding displacement of primary fossil-fuel consumption. Both the emissions and fossil-fuel consumption reductions are significantly larger (by 36% and 18%, respectively) than those achieved by an equivalent PV-only system with the same peak rating/installed capacity. The present paper proceeds further, by

  17. A novel integrated thermal-/membrane-based solar energy-driven hybrid desalination system: Concept description and simulation results.

    Science.gov (United States)

    Kim, Young-Deuk; Thu, Kyaw; Ng, Kim Choon; Amy, Gary L; Ghaffour, Noreddine

    2016-09-01

    In this paper, a hybrid desalination system consisting of vacuum membrane distillation (VMD) and adsorption desalination (AD) units, designated as VMD-AD cycle, is proposed. The synergetic integration of the VMD and AD is demonstrated where a useful effect of the AD cycle is channelled to boost the operation of the VMD process, namely the low vacuum environment to maintain the high pressure gradient across the microporous hydrophobic membrane. A solar-assisted multi-stage VMD-AD hybrid desalination system with temperature modulating unit is first designed, and its performance is then examined with a mathematical model of each component in the system and compared with the VMD-only system with temperature modulating and heat recovery units. The total water production and water recovery ratio of a solar-assisted 24-stage VMD-AD hybrid system are found to be about 21% and 23% higher, respectively, as compared to the VMD-only system. For the solar-assisted 24-stage VMD-AD desalination system having 150 m(2) of evacuated-tube collectors and 10 m(3) seawater storage tanks, both annual collector efficiency and solar fraction are close to 60%. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. A novel integrated thermal-/membrane-based solar energy-driven hybrid desalination system: Concept description and simulation results

    KAUST Repository

    Kim, Youngdeuk

    2016-05-03

    In this paper, a hybrid desalination system consisting of vacuum membrane distillation (VMD) and adsorption desalination (AD) units, designated as VMD-AD cycle, is proposed. The synergetic integration of the VMD and AD is demonstrated where a useful effect of the AD cycle is channelled to boost the operation of the VMD process, namely the low vacuum environment to maintain the high pressure gradient across the microporous hydrophobic membrane. A solar-assisted multi-stage VMD-AD hybrid desalination system with temperature modulating unit is first designed, and its performance is then examined with a mathematical model of each component in the system and compared with the VMD-only system with temperature modulating and heat recovery units. The total water production and water recovery ratio of a solar-assisted 24-stage VMD-AD hybrid system are found to be about 21% and 23% higher, respectively, as compared to the VMD-only system. For the solar-assisted 24-stage VMD-AD desalination system having 150 m2 of evacuated-tube collectors and 10 m3 seawater storage tanks, both annual collector efficiency and solar fraction are close to 60%.

  19. The Radiological and Thermal Characteristics of Fission Waste from a Deep-Burn Fusion-Fission Hybrid (LIFE) and Implications for Repository Performance

    International Nuclear Information System (INIS)

    Shaw, H.F.; Blink, J.; Farmer, J.; Latkowski, J.; Kramer, K.

    2009-01-01

    We are studying the use of a Laser Inertial-confinement Fusion Engine (LIFE) to drive a hybrid fusion-fission system that can generate electrical power and/or burn nuclear waste. The system uses the neutrons from laser driven ICF to produce tritium and to drive nuclear reactions in a subcritical fission blanket. The fusion neutron source obviates the need for a self-sustaining chain reaction in the fission blanket. Either fissile or fertile could be used as fission fuel, thus eliminating the need for isotopic enrichment. The 'driven' system potentially allows very high levels of burnup to be reached, extracting a large fraction of the available energy in the fission fuel without the need for reprocessing. In this note, we discuss the radionuclide inventory of a depleted uranium (DU) fuel burned to greater than 95% FIMA (Fissions per Initial heavy Metal Atom), the implications for thermal management of the resulting waste, and the implications of this waste for meeting the dose standards for releases from a geological repository for high-level waste. The fission waste discussed here would be that produced by a LIFE hybrid with a 500-MW fusion source. The fusion neutrons are multiplied and moderated by a sequence of concentric shells of materials before encountering the fission fuel, and fission in this region is largely due to thermal neutrons. The fission blanket consists of 40 metric tons (MT) of DU, assumed to be in the form of TRISO-like UOC fuel particles embedded in 2-cm-diameter graphite pebbles. (It is recognized that TRISO-based fuel may not reach the high burnup of the fertile fuel considered here, and other fuel options are being investigated. We postulate the existence of a fuel that can reach >95% FIMA so that the waste disposal implications of high burnup can be assessed.) The engine and plant design considered here would receive one load of fission fuel and produce ∼2 GWt of power (fusion + fission) over its 50- to 70-year lifetime. Neutron and

  20. Effects of thermal treatment on the structure and luminescent properties of Eu3+ doped SiO2–PMMA hybrid nanocomposites prepared by a sol–gel process

    International Nuclear Information System (INIS)

    Jesus, Filipe Augusto de; Tarse Sobrinho Santos, Simei; Caiut, José Maurício Almeida; Sarmento, Victor Hugo Vitorino

    2016-01-01

    Hybrid nanocomposites are multifunctional materials and their properties are the consequence of molecular interaction between inorganic and organic phases. These materials are interesting hosts for lanthanide ions, such as Eu 3+ . The purpose of this research was to synthesize Eu 3+ doped SiO 2 –PMMA hybrid nanocomposites by a sol–gel process and to study the effects of thermal treatment on the structure and luminescent properties of the material. Structural characterization was carried out using the FTIR, TG and 29 Si NMR techniques, however, the luminescence studies were more sensitive to detect the slight structural changes resulting from the thermal treatment. The Eu 3+ ions inserted into the matrix behaved as a structural probe and make it possible to notice the symmetry change from Eu 3+ site, the decrease in the number of hydroxyl coordinated groups and the improvement in quantum efficiency as a result of the thermal treatment. In addition, the Judd–Ofelt intensity parameters were obtained and supported the interaction between the rare earth and hybrid material. The hybrid was obtained as a stable material until 200 °C and the high sensitivity of the Eu 3+ ions in the system may be used in future applications as thermal sensors, for example. - Highlights: • Eu 3+ -doped SiO 2 –PMMA hybrid nanocomposites were synthesized through a sol–gel process. • FTIR, NMR and TG techniques were used to structural characterization of the material. • Luminescence analysis showed changes in Eu 3+ coordination sphere caused by thermal treatments. • Thermal treatments increase the interaction between the lanthanide ions and the host. • There was a huge improvement in the quantum efficiency of Eu 3+ in heat treated sample.

  1. Effects of thermal treatment on the structure and luminescent properties of Eu{sup 3+} doped SiO{sub 2}–PMMA hybrid nanocomposites prepared by a sol–gel process

    Energy Technology Data Exchange (ETDEWEB)

    Jesus, Filipe Augusto de; Tarse Sobrinho Santos, Simei [Departamento de Química, Universidade Federal de Sergipe, Av. Vereador Olímpio Grande s/n, Centro, Itabaiana, SE (Brazil); Caiut, José Maurício Almeida [Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-901 Ribeirão Preto, SP (Brazil); Sarmento, Victor Hugo Vitorino, E-mail: vhsarmento@ufs.br [Departamento de Química, Universidade Federal de Sergipe, Av. Vereador Olímpio Grande s/n, Centro, Itabaiana, SE (Brazil)

    2016-02-15

    Hybrid nanocomposites are multifunctional materials and their properties are the consequence of molecular interaction between inorganic and organic phases. These materials are interesting hosts for lanthanide ions, such as Eu{sup 3+}. The purpose of this research was to synthesize Eu{sup 3+} doped SiO{sub 2}–PMMA hybrid nanocomposites by a sol–gel process and to study the effects of thermal treatment on the structure and luminescent properties of the material. Structural characterization was carried out using the FTIR, TG and {sup 29}Si NMR techniques, however, the luminescence studies were more sensitive to detect the slight structural changes resulting from the thermal treatment. The Eu{sup 3+} ions inserted into the matrix behaved as a structural probe and make it possible to notice the symmetry change from Eu{sup 3+} site, the decrease in the number of hydroxyl coordinated groups and the improvement in quantum efficiency as a result of the thermal treatment. In addition, the Judd–Ofelt intensity parameters were obtained and supported the interaction between the rare earth and hybrid material. The hybrid was obtained as a stable material until 200 °C and the high sensitivity of the Eu{sup 3+} ions in the system may be used in future applications as thermal sensors, for example. - Highlights: • Eu{sup 3+}-doped SiO{sub 2}–PMMA hybrid nanocomposites were synthesized through a sol–gel process. • FTIR, NMR and TG techniques were used to structural characterization of the material. • Luminescence analysis showed changes in Eu{sup 3+} coordination sphere caused by thermal treatments. • Thermal treatments increase the interaction between the lanthanide ions and the host. • There was a huge improvement in the quantum efficiency of Eu{sup 3+} in heat treated sample.

  2. Performance Characterisation of a Hybrid Flat-Plate Vacuum Insulated Photovoltaic/Thermal Solar Power Module in Subtropical Climate

    Directory of Open Access Journals (Sweden)

    Andrew Y. A. Oyieke

    2016-01-01

    Full Text Available A flat-plate Vacuum Insulated Photovoltaic and Thermal (VIPV/T system has been thermodynamically simulated and experimentally evaluated to assess the thermal and electrical performance as well as energy conversion efficiencies under a subtropical climate. A simulation model made of specified components is developed in Transient Systems (TRNSYS environment into which numerical energy balance equations are implemented. The influence of vacuum insulation on the system’s electrical and thermal yields has been evaluated using temperatures, current, voltage, and power flows over daily and annual cycles under local meteorological conditions. The results from an experiment conducted under steady-state conditions in Durban, South Africa, are compared with the simulation based on the actual daily weather data. The VIPV/T has shown improved overall and thermal efficiencies of 9.5% and 16.8%, respectively, while electrical efficiency marginally reduced by 0.02% compared to the conventional PV/T. The simulated annual overall efficiency of 29% (i.e., 18% thermal and 11% electrical has been realised, in addition to the solar fraction, overall exergy, and primary energy saving efficiencies of 39%, 29%, and 27%, respectively.

  3. Charging and discharging tests for obtaining an accurate dynamic electro-thermal model of high power lithium-ion pack system for hybrid and EV applications

    DEFF Research Database (Denmark)

    Mihet-Popa, Lucian; Camacho, Oscar Mauricio Forero; Nørgård, Per Bromand

    2013-01-01

    This paper presents a battery test platform including two Li-ion battery designed for hybrid and EV applications, and charging/discharging tests under different operating conditions carried out for developing an accurate dynamic electro-thermal model of a high power Li-ion battery pack system....... The aim of the tests has been to study the impact of the battery degradation and to find out the dynamic characteristics of the cells including nonlinear open circuit voltage, series resistance and parallel transient circuit at different charge/discharge currents and cell temperature. An equivalent...... circuit model, based on the runtime battery model and the Thevenin circuit model, with parameters obtained from the tests and depending on SOC, current and temperature has been implemented in MATLAB/Simulink and Power Factory. A good alignment between simulations and measurements has been found....

  4. Electrochemical modeling and performance evaluation of a new ammonia-based battery thermal management system for electric and hybrid electric vehicles

    International Nuclear Information System (INIS)

    Al-Zareer, Maan; Dincer, Ibrahim; Rosen, Marc A.

    2017-01-01

    The operating temperatures of lithium ion battery packs in electrical vehicles and hybrid electrical vehicles need to be maintained in an optimum range for better performance and longer battery life. This paper proposes a new battery pack cooling system that utilizes the low saturation temperature of the fuel in ammonia based future hybrid electric vehicles. In the proposed cooling system, the batteries are partially submerged in to the liquid ammonia, and the liquid ammonia cools the battery by absorbing the heat and evaporating and the ammonia vapor cools the part of the battery not covered by liquid ammonia. The relationships between the performance of the battery cooling system and the maximum temperature (and the temperature distribution) in the battery are investigated for practical applications. The effect of the length of the battery that is submerged in to the liquid ammonia on the thermal performance of battery is studied and evaluated. The present results show that the proposed ammonia based cooling system offers a unique opportunity to maintain the operating temperature of the battery in an optimum range for consecutive charging and discharging phases at a high rate of 7.5C.

  5. A hybrid method of incorporating extended priority list into equal incremental principle for energy-saving generation dispatch of thermal power systems

    International Nuclear Information System (INIS)

    Cheng, Chuntian; Li, Shushan; Li, Gang

    2014-01-01

    The energy-saving generation dispatch (ESGD) policy released by Chinese Government in 2007 is a new code for optimally dispatching electric power generation portfolio in the country with the dual objectives of improving energy efficiency and reducing environmental pollution. The ESGD is substantially different from the competitive market in the developed economies, the traditional economic dispatching or the rational dispatching principle implemented in China prior to the new policy. This paper develops a hybrid method that integrates the extended priority list (EPL), the equal incremental principle (EIP) and a heuristic method to optimize daily generation schedules under ESGD. The EPL is presented to search desirable units set that satisfies the complicated duration period requirements based on thermal unit generation priority list. The EIP is developed to allocate load among the committed units within the combined set. A heuristic method is proposed to deal with inequality constraints, which usually result in difficulty for power allocation, and used to improve these results. The algorithm has been embedded into a newly developed decision support system that is currently being used by operators of the Guizhou Province Power Grid to make day-ahead quarter-hourly generation schedules. - Highlights: • Electric power industry is one of key and important fields for energy conservation and emission reduction in China. • The energy-saving generation dispatch policy was released by Chinese government in 2007. • A Hybrid algorithm for energy-saving generation dispatch scheduling of thermal power system is presented. • The algorithm has been embedded into a newly developed decision support system

  6. Experimental investigations of hybrid PV/Spiral flow thermal collector system performance using Al2O3/water nanofluid

    Science.gov (United States)

    Gangadevi, R.; Vinayagam, B. K.; Senthilraja, S.

    2017-05-01

    In this paper, the PV/T (Photovoltaic thermal unit) system is investigated experimentally to examine the thermal, electrical and overall efficiency by circulating Al2O3/water nanofluid of 1wt% and 2wt% with an optimum flow rate of 40L/H. The overall efficiency of PVT system is largely influenced by various factors such as heat due to photovoltaic action; energy radiated at the infrared wavelength of the solar spectrum, solar irradiance, mounting structure, tilt angle, wind speed direction, Ambient temperature and panel material composition. However, the major factor is considered in this study to extract the heat generated in the PV panel by using nanofluid as a coolant to increase the overall system efficiency. Therefore, the result shows that by using 2 wt% Al2O3/water nanofluid the electrical efficiency, thermal efficiency and overall efficiency of the PVT system enhanced by 13%, 45%, and 58% respectively compared with water.

  7. Heat transfer efficiency of Al2O3-MWCNT/thermal oil hybrid nanofluid as a cooling fluid in thermal and energy management applications: An experimental and theoretical investigation

    DEFF Research Database (Denmark)

    Asadi, Amin; Asadi, Meisam; Rezaniakolaei, Alireza

    2018-01-01

    efficiency of the nanofluid has been evaluated based on different figures of merit. It is revealed that using this nanofluid instead of the base fluid can be beneficial in all the studied solid concentrations and temperatures for both the internal laminar and turbulent flow regimes except the solid...... concentrations of 1 and 1.5% in internal turbulent flow regimes. The effect of adding nanoparticles on pumping power and convective heat transfer coefficient has also been theoretically investigated.......The main objective of the present study is to assess the heat transfer efficiency of Al2O3-MWCNT/thermal oil hybrid nanofluid over different temperatures (25–50 °C) and solid concentrations (0.125%–1.5%). To this end, first of all, the stability of the nano-oil has been studied through the Zeta...

  8. Fabrication and Characteristics of ZnO/OAD-InN/PbPc Hybrid Solar Cells Prepared by Oblique-Angle Deposition

    Directory of Open Access Journals (Sweden)

    Lung-Chien Chen

    2012-08-01

    Full Text Available In this work, lead phthalocyanine (PbPc and ZnO/InN inorganic semiconductor films prepared by oblique-angle deposition (OAD were layered to form heterojunction organic/inorganic hybrid photovoltaic solar cells. Among the available organic materials, phthalocyanines, particularly the non-planar ones such as PbPc, are notable for their absorption in the visible and near infrared regions. The organic/inorganic hybrid solar cells fabricated on ZnO/OAD-InN/PbPc showed short-circuit current density (JSC, open-circuit voltage (VOC, and power conversion efficiencies (η of 1.2 mA/cm2, 0.6 V and 0.144%, respectively.

  9. System for electric power generation with photovoltaic solar modules for charging the batteries of an electric wheelchair; Sistema de geracao de energia eletrica com modulos solares fotovoltaicos para o carregamento de baterias de uma cadeira de rodas eletrica

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita, Rafael Pimenta; Souza, Teofilo Miguel de [Universidade Estadual Paulista (UNESP), Guaratinguta, SP (Brazil). Fac. de Engenharia. Dept. de Engenharia Eletrica], Emails: pimentamesquita@gmail.com, teofilo@feg.unesp.br

    2006-07-01

    Renewable energy is all kind of energy produced from a natural source that not diminish because its utilization is 'renewable'. More and more renewable energy resources are used, because they offer multiple advantages such as the energy output facility in small scale and because they are entirely compatible with the environment. The renewable energy used in this project is the photovoltaic solar energy, obtained by the direct conversion of the solar energy in electric energy through the use of solar cells, that can be of several kinds, being the most common of silicon. The main advantage of photovoltaic system is the generation of clean electric energy, or either, generates energy without emitting pollutant and without destroying the environment, moreover is an inexhaustible source of energy. The main disadvantage is, nowadays, the high cost and its low efficiency, so to continue developing it is necessary establish capable mechanisms to make it possible. The search of these mechanisms of incentive becomes-itself a lot important, because the renewable energy and not conventional do not produce a financial return to the investor properly said, but brings lots of benefits to the community, the society and to the environment. This project has the purpose of create an electric energy generation system through solar photovoltaic modules to carry batteries of a motorized wheelchair. An electric wheelchair is moved by electric motors of direct current that are feed by batteries, permitting a medium autonomy of 10 km by load. The batteries are recharged by a battery supplier. This operation should be carried out daily in a space of 6 to 8 hours. According to the Demographic Census realized in 2000 carried out by the IBGE, Brazil has around 1.416.060 physical deficient, which 861.196 are men and 554.864 are women. From a request of a user of electric wheelchair the idea of this project was shown up. The user complained that he stayed a long time carrying his seat

  10. High-energy, stable and recycled molecular solar thermal storage materials using AZO/graphene hybrids by optimizing hydrogen bonds.

    Science.gov (United States)

    Luo, Wen; Feng, Yiyu; Qin, Chengqun; Li, Man; Li, Shipei; Cao, Chen; Long, Peng; Liu, Enzuo; Hu, Wenping; Yoshino, Katsumi; Feng, Wei

    2015-10-21

    An important method for establishing a high-energy, stable and recycled molecular solar heat system is by designing and preparing novel photo-isomerizable molecules with a high enthalpy and a long thermal life by controlling molecular interactions. A meta- and ortho-bis-substituted azobenzene chromophore (AZO) is covalently grafted onto reduced graphene oxide (RGO) for solar thermal storage materials. High grafting degree and close-packed molecules enable intermolecular hydrogen bonds (H-bonds) for both trans-(E) and cis-(Z) isomers of AZO on the surface of nanosheets, resulting in a dramatic increase in enthalpy and lifetime. The metastable Z-form of AZO on RGO is thermally stabilized with a half-life of 52 days by steric hindrance and intermolecular H-bonds calculated using density functional theory (DFT). The AZO-RGO fuel shows a high storage capacity of 138 Wh kg(-1) by optimizing intermolecular H-bonds with a good cycling stability for 50 cycles induced by visible light at 520 nm. Our work opens up a new method for making advanced molecular solar thermal storage materials by tuning molecular interactions on a nano-template.

  11. Novel hybrid drilling protocol: evaluation for the implant healing--thermal changes, crestal bone loss, and bone-to-implant contact.

    Science.gov (United States)

    Calvo-Guirado, José Luis; Delgado-Peña, Jorge; Maté-Sánchez, Jose E; Mareque Bueno, Javier; Delgado-Ruiz, Rafael Arcesio; Romanos, Georgios E

    2015-07-01

    To evaluate a new hybrid drilling protocol, by the analysis of thermal changes in vitro, and their effects in the crestal bone loss and bone-to-implant contact in vivo. Temperature changes during simulated osteotomies with a hybrid drilling technique (biologic plus simplified) (test) versus an incremental drilling technique (control) were investigated. One hundred and twenty random osteotomies were performed (60 by group) in pig ribs up to 3.75-mm-diameter drill to a depth of 10 mm. Thermal changes and time were recorded by paired thermocouples. In a parallel experiment, bilateral mandibular premolars P2, P3, P4, and first molar M1 were extracted from six dogs. After 2-month healing, implant sites were randomly prepared using either of the drilling techniques. Forty eight implants of 3.75 mm diameter and 10 mm length were inserted. The dogs were euthanized at 30 and 90 days, and crestal bone loss (CBL) and bone-to-implant contact (BIC) were evaluated. The control group showed maximum temperatures of 35.3 °C ± 1.8 °C, ΔT of 10.4 °C, and a mean time of 100 s/procedure; meanwhile, the test group showed maximum temperatures of 36.7 °C ± 1.2 °C, ΔT of 8.1 °C, and a mean time of 240 s/procedure. After 30 days, CBL values for both groups (test: 1.168 ± 0.194 mm; control: 1.181 ± 0.113 mm) and BIC values (test: 43 ± 2.8%; control: 45 ± 1.3%) were similar, without significant differences (P > 0.05). After 90 days, CBL (test: 1.173 ± 0.187 mm; control: 1.205 ± 0.122 mm) and BIC (test: 64 ± 3.3%; control: 64 ± 2.4%) values were similar, without significant differences (P > 0.05). The BIC values were increased at 90 days in both groups compared with the 30-day period (P drilling procedure in vitro. Crestal bone loss and bone-to-implant contact in the hybrid drilling protocol are comparable with the conventional drilling protocol and do not affect the osseointegration process in vivo. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Mechanical design of a free-wheel clutch for the thermal engine of a parallel hybrid vehicle with thermal and electrical power-train; Conception mecanique d'un accouplement a roue libre pour le moteur thermique d'un vehicule hybride parallele thermique et electrique

    Energy Technology Data Exchange (ETDEWEB)

    Santin, J.J.

    2001-07-01

    This thesis deals with the design of a free-wheel clutch. This unit is intended to replace the automated dry single-plate clutch of a parallel hybrid car with thermal and electric power-train. Furthermore, the car is a single shaft zero emission vehicle fitted with a controlled gearbox. Chapter one focuses on the type of hybrid vehicle studied. It shows the need to isolate the engine from the rest of the drive train, depending on the driving conditions. Chapter two presents and compares the two alternatives: automated clutch and free-wheel. In order to develop the free-wheel option, the torsional vibrations in the automotive drive line had to be closely studied. It required the design of a specific modular tool, as presented in chapter three, with the help of MATLAB SIMULINK. Lastly, chapter four shows how this tool was used during the design stage and specifies the way to build it. The free-wheel is then to be fitted to a prototype hybrid vehicle, constructed by both the LAMIH and PSA. (author)

  13. Thermal Performance of Motor and Inverter in an Integrated Starter Generator System for a Hybrid Electric Vehicle

    OpenAIRE

    Sung Chul Kim

    2013-01-01

    If the integrated starter generator (ISG) motor and inverter operate under continuously high loading conditions, the system’s performance and durability will decrease and the heat dissipation requirements will increase. Therefore, in this study, we developed two cooling designs for the ISG motor and inverter, and then carried out both a model analysis and an experiment on the fluid flow and thermal characteristics of the system under various operating conditions. As the outdoor temperature in...

  14. Three-Dimensional Modeling of the Thermal Behavior of a Lithium-Ion Battery Module for Hybrid Electric Vehicle Applications

    Directory of Open Access Journals (Sweden)

    Jaeshin Yi

    2014-11-01

    Full Text Available This paper reports a modeling methodology to predict the effects of operating conditions on the thermal behavior of a lithium-ion battery (LIB module. The potential and current density distributions on the electrodes of an LIB cell are predicted as a function of discharge time based on the principle of charge conservation. By using the modeling results of the potential and current density distributions of the LIB cell, the non-uniform distribution of the heat generation rate in a single LIB cell within the module is calculated. Based on the heat generation rate in the single LIB cell determined as a function of the position on the electrode and time, a three-dimensional thermal modeling of an LIB module is performed to calculate the three-dimensional velocity, pressure, and temperature distributions within the LIB module as a function of time at various operating conditions. Thermal modeling of an LIB module is validated by the comparison between the experimental measurements and the modeling results. The effect of the cooling condition of the LIB module on the temperature rise of the LIB cells within the module and the uniformity of the distribution of the cell temperatures are analyzed quantitatively based on the modeling results.

  15. Thermally Stable Siloxane Hybrid Matrix with Low Dielectric Loss for Copper-Clad Laminates for High-Frequency Applications.

    Science.gov (United States)

    Kim, Yong Ho; Lim, Young-Woo; Kim, Yun Hyeok; Bae, Byeong-Soo

    2016-04-06

    We report vinyl-phenyl siloxane hybrid material (VPH) that can be used as a matrix for copper-clad laminates (CCLs) for high-frequency applications. The CCLs, with a VPH matrix fabricated via radical polymerization of resin blend consisting of sol-gel-derived linear vinyl oligosiloxane and bulky siloxane monomer, phenyltris(trimethylsiloxy)silane, achieve low dielectric constant (Dk) and dissipation factor (Df). The CCLs with the VPH matrix exhibit excellent dielectric performance (Dk = 2.75, Df = 0.0015 at 1 GHz) with stability in wide frequency range (1 MHz to 10 GHz) and at high temperature (up to 275 °C). Also, the VPH shows good flame resistance without any additives. These results suggest the potential of the VPH for use in high-speed IC boards.

  16. Fissile fuel production and usage of thermal reactor waste fueled with UO2 by means of hybrid reactor system

    International Nuclear Information System (INIS)

    Ipek, O.

    1997-01-01

    The use of Fast Breeder Reactors to produce fissile fuel from nuclear waste and the operation of these reactors with a new neutron source are becoming today' topic. In the thermonuclear reactors, it is possible to use 2.45-14.1 MeV - neutrons which can be obtained by D-T, D-D Semicatalyzed (D-D) and other fusion reactions. To be able to do these, Hybrid Reactor System, which still has experimental and theoretical studies, have to be taken into consideration.In this study, neutronic analysis of hybrid blanket with grafit reflector, is performed. D-T driven fusion reaction is surrounded by UO 2 fuel layer and the production of ''2''3''9Pu fissile fuel from waste ''2''3''8U is analyzed. It is also compared to the other possible fusion reactions. The results show that 815.8 kg/year ''2''3''8Pu with D-T reaction and 1431.6 kg/year ''2''3''8Pu with semicatalyzed (D-D) reaction can be produced for 1000 MW fusion power. This means production of 2.8/ year and 4.94/ year LWR respectively. In addition, 1000 MW fusion flower is is multiplicated to 3415 MW and 4274 MW for D-T and semicatalyzed (D-D) reactions respectively. The system works subcritical and these values are 0.4115 and 0.312 in order. The calculations, ANISN-ORNL code, S 16 -P 3 approach and DLC36 data library are used

  17. Design and dynamic simulation of a novel solar trigeneration system based on hybrid photovoltaic/thermal collectors (PVT)

    International Nuclear Information System (INIS)

    Calise, Francesco; D’Accadia, Massimo Dentice; Vanoli, Laura

    2012-01-01

    Highlights: ► Sheet and tube photovoltaic/thermal (PVT) solar collector are investigated. ► PVT is integrated in a novel solar trigeneration system. ► The trigeneration system is dynamically investigated for a mediterranean climate. ► PVT performance is excellent during the summer. ► During the winter PVT thermal energy significantly decreases. - Abstract: In this paper, a Solar Heating and Cooling (SHC) system including photovoltaic/thermal (PVT) collectors is considered, implementing a novel polygeneration system producing electricity, space heating and cooling and domestic hot water. In particular, PVT collectors operating up to 80 °C are considered. A case study for a university building located in Naples (Italy) is developed and discussed. The system is mainly composed by: PVT collectors, a single-stage LiBr–H 2 O absorption chiller, storage tanks and auxiliary heaters. The system also includes additional balance-of-plant devices: heat exchangers, pumps, controllers, cooling tower, etc. The PVT produces electricity which is utilized in part by the building lights and equipments and in part by the system parasitic loads; the rest is eventually sold to the grid. Simultaneously, the PVT system provides the heat required to drive the absorption chiller. The system performance is analyzed from both energetic and economic points of view by means of a zero-dimensional transient simulation model, developed with TRNSYS. The economic results show that the system under investigation can be profitable, provided that an appropriate funding policy is available. In addition, the overall energetic and economic results are comparable to those reported in literature for similar systems.

  18. Organic Photovoltaic Solar Cells | Photovoltaic Research | NREL

    Science.gov (United States)

    fundamentals of device operation, including charge-separation processes, charge-transport mechanisms, device . Our Expertise NCPV scientists use this coating system in developing OPV films in the lab. We have system that allows us to measure the lifetime of thin-film devices under light, at different substrate

  19. Better chances for photovoltaic solar energy

    International Nuclear Information System (INIS)

    Sinke, W.C.

    1992-01-01

    There is a growing interest in the use of solar energy based on the policy to reduce the emission of carbon dioxide and acidifying pollutants, and the desire to save energy, in particular with regard to the increase of energy consumption, which can be expected to occur in the near future in developing countries. After a brief introduction on the efficiencies of monocrystalline silicon (m-Si), polycrystalline silicon (p-Si) and amorphous silicon (a-Si) solar cells realized sofar, attention is paid to two remarkable developments in solar cell research. One is at Texas Instruments where silicon balls in aluminium foil are fabricated, for which the average energy efficiency realized sofar is 10% for small surfaces (10 cm 2 ). The cell is called the spheral solar cell. A second development is at the Federal Institute for Technology in Lausanne, Switzerland, where the researchers O'Regan and Graetzel reported on the development of a photo-electrochemical solar cell with a high efficiency and good stability. Their cell is dye sensitized, which means that the light absorption function of the cell is separated from the load transport function. Finally brief attention is paid to the introduction and use of solar home systems in Indonesia. 5 figs

  20. Silicon nanowires for photovoltaic solar energy conversion.

    Science.gov (United States)

    Peng, Kui-Qing; Lee, Shuit-Tong

    2011-01-11

    Semiconductor nanowires are attracting intense interest as a promising material for solar energy conversion for the new-generation photovoltaic (PV) technology. In particular, silicon nanowires (SiNWs) are under active investigation for PV applications because they offer novel approaches for solar-to-electric energy conversion leading to high-efficiency devices via simple manufacturing. This article reviews the recent developments in the utilization of SiNWs for PV applications, the relationship between SiNW-based PV device structure and performance, and the challenges to obtaining high-performance cost-effective solar cells.

  1. Aerodynamical study of a photovoltaic solar tracker

    OpenAIRE

    Gutiérrez Castillo, José Leonardo

    2016-01-01

    Investigate the aerodynamic features of ground-mounted solar trackers under atmospheric boundary layer flows. Study and identify the aerodynamical interactions of solar trackers when they are displayed as an array. State of the art. Literature review about CFD applied to solar panels. Analytic approach of the problem. Application of CFD analysis. Validation of the results. Discussion of the results. Improvements proposal.

  2. Cost reductions in photovoltaics - Solar selection

    International Nuclear Information System (INIS)

    Rentzing, S.

    2009-01-01

    This article discusses the effect of the economic recession on the solar industry. Whilst certain companies fight to survive, margins are sinking and badly-positioned companies and expensive technologies are being pushed out of the market. The author goes on to take a look at business figures and the throttling back of production, even in China. Sinking module prices and sufficient supplies of silicon are commented on. Top companies that provide good value for money are noted and markets such as that in the USA will, according to the author, develop further, thanks to government funding

  3. Photovoltaic solar energy: State of the art

    International Nuclear Information System (INIS)

    Van Sark, W.G.J.H.M.; Sinke, W.C.

    1993-03-01

    Attention is paid to developments in the Netherlands of all aspects of photovoltaic (PV) energy: solar cells, components, PV-systems and all kinds of applications. Efficiencies of the present solar cell types still increase, varying from more than 10% for organic/TiO 2 solar cells to 33% for GaAs/GaSb concentrator tandem solar cells. 3 figs., 2 ills., 1 tab

  4. The Italian programme in photovoltaic solar energy

    Science.gov (United States)

    Farinelli, U.

    Italian programs and goals for developing a photovoltaic (PV) industry and market are outlined. It is suggested that only a few megawatts of PVs will be produced for domestic consumption in the next few years, while the largest market is for developing nations where costly diesel-fueled generators are used. The installation of PV systems in developing areas will permit testing and scaling up of production capacities from several MW to several hundred MW and then to GW annual production. Approximately 55,000,000 was devoted to government research in PV in 1982 and a PV research laboratory is being built near Naples.

  5. Mathematical models for photovoltaic solar panel simulation

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Jose Airton A. dos; Gnoatto, Estor; Fischborn, Marcos; Kavanagh, Edward [Universidade Tecnologica Federal do Parana (UTFPR), Medianeira, PR (Brazil)], Emails: airton@utfpr.edu.br, gnoatto@utfpr.edu.br, fisch@utfpr.edu.br, kavanagh@utfpr.edu.br

    2008-07-01

    A photovoltaic generator is subject to several variations of solar intensity, ambient temperature or load, that change your point of operation. This way, your behavior should be analyzed by such alterations, to optimize your operation. The present work sought to simulate a photovoltaic generator, of polycrystalline silicon, by characteristics supplied by the manufacturer, and to compare the results of two mathematical models with obtained values of field, in the city of Cascavel, for a period of one year. (author)

  6. Electrical conductivity of the thermal dusty plasma under the conditions of a hybrid plasma environment simulation facility

    Science.gov (United States)

    Zhukhovitskii, Dmitry I.; Petrov, Oleg F.; Hyde, Truell W.; Herdrich, Georg; Laufer, Rene; Dropmann, Michael; Matthews, Lorin S.

    2015-05-01

    We discuss the inductively heated plasma generator (IPG) facility in application to the generation of the thermal dusty plasma formed by the positively charged dust particles and the electrons emitted by them. We develop a theoretical model for the calculation of plasma electrical conductivity under typical conditions of the IPG. We show that the electrical conductivity of dusty plasma is defined by collisions with the neutral gas molecules and by the electron number density. The latter is calculated in the approximations of an ideal and strongly coupled particle system and in the regime of weak and strong screening of the particle charge. The maximum attainable electron number density and corresponding maximum plasma electrical conductivity prove to be independent of the particle emissivity. Analysis of available experiments is performed, in particular, of our recent experiment with plasma formed by the combustion products of a propane-air mixture and the CeO2 particles injected into it. A good correlation between the theory and experimental data points to the adequacy of our approach. Our main conclusion is that a level of the electrical conductivity due to the thermal ionization of the dust particles is sufficiently high to compete with that of the potassium-doped plasmas.

  7. Photochromic and thermal properties of poly(vinyl alcohol)/H6P2W18O62 hybrid membranes

    International Nuclear Information System (INIS)

    Gong Jian; Li Xiangdan; Shao Changlu; Ding Bin; Lee, Douk-Rae; Kim, Hak-Yong

    2003-01-01

    Poly(vinyl alcohol) (PVA) films, which contained different content of heteropolyacid (HPA) with Dawson-Wells structure, were prepared. The photochromic behavior was investigated by using ultraviolet-visible (UV-Vis) absorption spectroscopy. The result indicated that the film was reduced photochemically to yield a blue species under UV irradiation, and the color of the film changed to deep blue with increasing irradiation time and HPA content. The photochromic sensibility of different UV wavelength was investigated. In the UV-Vis spectra of the irradiated films, an isobestic point was observed at about 352 nm. The reduction mechanism of the heteropolyanion (W 6+ →W 5+ ) was suggested. The thermal property and the conductivity of the film were also studied. The thermal degradation step and the melting point of the film were influenced by different content of the HPA. Notably, the conductivity of 8.33x10 -6 S cm -1 was observed when the HPA content was 80 wt.%

  8. Tuning of the Seebeck Coefficient and the Electrical and Thermal Conductivity of Hybrid Materials Based on Polypyrrole and Bismuth Nanowires.

    Science.gov (United States)

    Hnida, Katarzyna E; Pilarczyk, Kacper; Knutelski, Marcin; Marzec, Mateusz; Gajewska, Marta; Kosonowski, Artur; Chlebda, Damian; Lis, Bartłomiej; Przybylski, Marek

    2018-04-06

    The growing demand for clean energy catalyzes the development of new devices capable of generating electricity from renewable energy resources. One of the possible approaches focuses on the use of thermoelectric materials (TE), which may utilize waste heat, water, and solar thermal energy to generate electrical power. An improvement of the performance of such devices may be achieved through the development of composites made of an organic matrix filled with nanostructured thermoelectric materials working in a synergetic way. The first step towards such designs requires a better understanding of the fundamental interactions between available materials. In this paper, this matter is investigated and the questions regarding the change of electrical and thermal properties of nanocomposites based on low-conductive polypyrrole enriched with bismuth nanowires of well-defined geometry and morphology is answered. It is clearly demonstrated that the electrical conductivity and the Seebeck coefficient may be tuned either simultaneously or separately within particular Bi NWs content ranges, and that both parameters may be increased at the same time. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Analysis of a Hybrid PV/Thermal Solar-Assisted Heat Pump System for Sports Center Water Heating Application

    Directory of Open Access Journals (Sweden)

    Y. Bai

    2012-01-01

    Full Text Available The application of solar energy provides an alternative way to replace the primary source of energy, especially for large-scale installations. Heat pump technology is also an effective means to reduce the consumption of fossil fuels. This paper presents a practical case study of combined hybrid PV/T solar assisted heat pump (SAHP system for sports center hot water production. The initial design procedure was first presented. The entire system was then modeled with the TRNSYS 16 computation environment and the energy performance was evaluated based on year round simulation results. The results show that the system COP can reach 4.1 under the subtropical climate of Hong Kong, and as compared to the conventional heating system, a high fractional factor of energy saving at 67% can be obtained. The energy performances of the same system under different climatic conditions, that include three other cities in France, were analyzed and compared. Economic implications were also considered in this study.

  10. Renewable Energy Systems: Development and Perspectives of a Hybrid Solar-Wind System

    Directory of Open Access Journals (Sweden)

    C. Shashidhar

    2012-02-01

    Full Text Available Considering the intermittent natural energy resources and the seasonal un-balance, a phtovoltaic-wind hybrid electrical power supply system was developed to accommodate remote locations where a conventional grid connection is inconvenient or expensive. However, the hybrid system can also be applied with grid connection and owners are allowed to sell excessive power back to the electric utility. The proposed set-up consists of a photo-voltaic solar-cell array, a mast mounted wind generator, lead-acid storage batteries, an inverter unit to convert DC to AC, electrical lighting loads, electrical heating loads, several fuse and junction boxes and associated wiring, and test instruments for measuring voltages, currents, power factors, and harmonic contamination data throughout the system. The proposed hybrid solar-wind power generating system can be extensively used to illustrate electrical concepts in hands-on laboratories and also for demonstrations in the Industrial Technology curriculum. This paper describes an analysis of local PV-wind hybrid systems for supplying electricity to a private house, farmhouse or small company with electrical power depending on the site needs. The major system components, work principle and specific working condition are presented.

  11. Device design of GaSb/CdS thin film thermal photovoltaic solar cells%基于GaSb/CdS薄膜热光伏电池的器件设计∗

    Institute of Scientific and Technical Information of China (English)

    吴限量; 张德贤; 蔡宏琨; 周严; 倪牮; 张建军

    2015-01-01

    基于GaSb薄膜热光伏器件是降低热光伏系统成本的有效途径之一,本文主要针对GaSb/CdS薄膜热光伏器件结构进行理论分析.采用AFORS-HET软件进行模拟仿真,分析GaSb和CdS两种材料各自的缺陷态密度、界面态对电池性能的影响.根据软件模拟可以得知,吸收层GaSb的缺陷态密度以及GaSb与CdS之间的界面态密度是影响电池性能的重要因素.当GaSb缺陷态增加时,主要影响电池的填充因子,电池效率明显下降.而作为窗口层的CdS缺陷态密度对电池性能影响不明显,当CdS缺陷态密度上升4个数量级时,电池效率仅下降0.11%.%Enthusiasm in the research of thermo-photovoltaic (TPV) cells has been aroused because the low bandwidth semi-conductors of III-V family are coming into use. GaSb, as a member of III-V family, has many merits such as high absorption coeffcient, and low band gap of 0.725 eV at 300 K etc.. At present thermo-photovoltaic cells are usually based on GaSb wafer, and it can be manufactured by the vertical Bridgeman method. Thermo-photovoltaic cell based on GaSb films is one of the effective ways to reduce the cost of the thermo-photovoltaic system. GaSb polycrystalline films can be grown by physical vapor deposition (PVD) which has advantages in using fewer materials and energy, and also in doing little harm to the environment. Because of residual acceptor defects VGaGaSb, GaSb thin film is usually of p-type semiconductor. So we should find n-type semiconductor material to form pn junction. We choose CdS as the emission layer of a cell structure. CdS belongs to n-type semiconductor with a narrow band gap of 2.4 eV and high light transmissivity. CdS thin film grown by chemical bath deposition (CBD) has passivation properties for GaSb. CdS layers can remove native oxides from GaSb surface and reduce the surface recombination velocity of GaSb. This paper focuses on theoretical analysis of GaSb/CdS thin film photovoltaic structure. By way of AFORS-HET simulation, we analyze the defect state density and interface density in GaSb and CdS, and their effects on cell performance. According to the simulation, the defect density in GaSb absorption layer is the very important factors that affect cell performance. When GaSb defect increases, the major factor to affect the cell is the fill factor that leads to low effciency. On condition that there exists high GaSb defect density, the thickness of GaSb should be kept at 1000 nm. GaSb with a thickness above 1000 nm can bring about a high recombination rate, which reduces the effciency of the cell. As an emission layer, the defect density in CdS should not affect the cell performance obviously. When the increase of CdS defect density is of four orders of magnitude, the cell effciency is only decreased by 0.11%. In order to demonstrate the interface between GaSb and CdS, we use an inversion layer n-GaSb according to the passivation properties of CdS thin film grown on GaSb. When the defect density of inversion layer increases, the effciency of the cell will decrease rapidly. And the GaSb/CdS structure will act as a resistance when the defect density in the inversion layer reaches 1020 cm−3. So the defect density in GaSb layer and the interface is the very factor to affect thermo-photovoltaic performance.

  12. 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)

  13. Hybrid white organic light-emitting devices consisting of a non-doped thermally activated delayed fluorescent emitter and an ultrathin phosphorescent emitter

    International Nuclear Information System (INIS)

    Zhao, Juan; Wang, Zijun; Wang, Run; Chi, Zhenguo; Yu, Junsheng

    2017-01-01

    Hybrid white organic light-emitting devices (OLEDs) are fabricated by employing non-doped emitting layers (EMLs), which are consisted of a blue thermally activated delayed fluorescent (TADF) emitter 9,9-dimethyl-9,10-dihydroacridine-diphenylsulfone (DMAC-DPS) and an ultrathin yellow iridium complex bis[2-(4-tertbutylphenyl)benzothiazolato-N,C 2′ ] iridium (acetylacetonate) [(tbt) 2 Ir(acac)]. With thickness optimization of DMAC-DPS, a white OLED achieves maximum current efficiency, power efficiency and external quantum efficiency of 34.9 cd/A, 29.2 lm/W and 11.4%, respectively, as well as warm white emission with relatively stable electroluminescence spectra. The results suggest that, bipolar charge carrier transport property and concentration independent property of DMAC-DPS, charge carrier trapping effect of the ultrathin (tbt) 2 Ir(acac), and balanced self-emission process and energy transfer process between DMAC-DPS and (tbt) 2 Ir(acac), contribute to high device performance.

  14. Hybrid white organic light-emitting devices consisting of a non-doped thermally activated delayed fluorescent emitter and an ultrathin phosphorescent emitter

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Juan [State Key Laboratory of Electronic Thin Film and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China, Chengdu 610054 (China); School of Chemistry, Sun Yat-sen University, Guangzhou 510275 (China); Wang, Zijun; Wang, Run [State Key Laboratory of Electronic Thin Film and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China, Chengdu 610054 (China); Chi, Zhenguo, E-mail: chizhg@mail.sysu.edu.cn [School of Chemistry, Sun Yat-sen University, Guangzhou 510275 (China); Yu, Junsheng, E-mail: jsyu@uestc.edu.cn [State Key Laboratory of Electronic Thin Film and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China, Chengdu 610054 (China)

    2017-04-15

    Hybrid white organic light-emitting devices (OLEDs) are fabricated by employing non-doped emitting layers (EMLs), which are consisted of a blue thermally activated delayed fluorescent (TADF) emitter 9,9-dimethyl-9,10-dihydroacridine-diphenylsulfone (DMAC-DPS) and an ultrathin yellow iridium complex bis[2-(4-tertbutylphenyl)benzothiazolato-N,C{sup 2′}] iridium (acetylacetonate) [(tbt){sub 2}Ir(acac)]. With thickness optimization of DMAC-DPS, a white OLED achieves maximum current efficiency, power efficiency and external quantum efficiency of 34.9 cd/A, 29.2 lm/W and 11.4%, respectively, as well as warm white emission with relatively stable electroluminescence spectra. The results suggest that, bipolar charge carrier transport property and concentration independent property of DMAC-DPS, charge carrier trapping effect of the ultrathin (tbt){sub 2}Ir(acac), and balanced self-emission process and energy transfer process between DMAC-DPS and (tbt){sub 2}Ir(acac), contribute to high device performance.

  15. Photovoltaic: state of the arts in France and in the world

    International Nuclear Information System (INIS)

    Jurczak, Ch.; Leclerq, M.

    2005-01-01

    The author analyzes the photovoltaic world solar market. He discusses the photovoltaic solar electricity production cost and more particularly the photovoltaic solar industry in France and the thermal solar. (A.L.B.)

  16. Influence of rf-magnetron Sputtered ITO and Al:ZnO on Photovoltaic Behaviour Related to CuInSe{sub 2}-Based Photovoltaic Solar Cells; Influencia del ITO y Al:ZnO, Fabricados mediante Pulverizacion Cataodica, sobre el Comportamiento Fotovoltaico de Dispositivos Basados en el CuInSe{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, M. A.; Guillen, C.; Dona, J. M.; Herrero, J.; Gutierrez, M. T. [Ciemat.Madrid (Spain)

    2000-07-01

    This paper describes several investigations, made in the CIEMAT, on the capability of depositing transparent conducting oxides at room temperature by rf-magnetron sputtering, and their application inCuInSe{sub 2}-based photovoltaic solar cells. ITO and Al:ZnO thin films having simultaneously high transmittance in the visible range and low resistivity, 10''3-10''4{omega}cm, can be obtained only if oxygen mass-flow rate is constrained to a very narrow range (0.5-1 sccm). Cell efficiency enhance when transparent conducting oxides are made without intentional heating and, after, the total devices are annealed in air at 200 degree centigree. (Author) 40 refs.

  17. Thermal performance of a buried nuclear waste storage container storing a hybrid mix of PWR and BWR spent fuel rods

    International Nuclear Information System (INIS)

    Johnson, G.L.

    1991-11-01

    Lawrence Livermore National Laboratory will design, model, and test nuclear waste packages for use at the Nevada Nuclear Waste Storage Repository at Yucca Mountain, Nevada. On such package would store tightly packed spent fuel rods from both pressurized and boiling water reactors. The storage container provides the primary containment of the nuclear waste and the spent fuel rod cladding provides secondary containment. A series of transient conduction and radiation heat transfer analyses was run to determine for the first 1000 yr of storage if the temperature of the tuff at the borehole wall ever falls below 97 degrees C and whether the cladding of the stored spent fuel ever exceeds 350 degrees C. Limiting the borehole to temperatures of 97 degrees C or greater helps minimize corrosion by assuring that no condensed water collects on the container. The 350 degrees C cladding limit minimizes the possibility of creep- related failure in the spent fuel rod cladding. For a series of packages stored in a 8 x 30 m borehole grid where each package contains 10-yr-old spent fuel rods generating 4.74 kW or more, the borehole wall stays above 97 degrees C for the full 10000-yr analysis period. For the 4.74-kW load, the peak cladding temperature rises to just below the 350 degrees C limit about 4 years after emplacement. If the packages are stored using the spacing specified in the Site Characterization Plan (15 ft x 126 ft), a maximum of 4.1 kW per container may be stored. If the 0.05-m-thick void between the container and the borehole wall is filled with loosely packed bentonite, the peak cladding temperature rises more than 40 degrees C above the allowed cladding limit. In all cases the dominant heat transfer mode between container components is thermal radiation

  18. Thermally robust and biomolecule-friendly room-temperature bonding for the fabrication of elastomer-plastic hybrid microdevices.

    Science.gov (United States)

    Nguyen, T P O; Tran, B M; Lee, N Y

    2016-08-16

    Here, we introduce a simple and fast method for bonding a poly(dimethylsiloxane) (PDMS) silicone elastomer to different plastics. In this technique, surface modification and subsequent bonding processes are performed at room temperature. Furthermore, only one chemical is needed, and no surface oxidation step is necessary prior to bonding. This bonding method is particularly suitable for encapsulating biomolecules that are sensitive to external stimuli, such as heat or plasma treatment, and for embedding fracturable materials prior to the bonding step. Microchannel-fabricated PDMS was first oxidized by plasma treatment and reacted with aminosilane by forming strong siloxane bonds (Si-O-Si) at room temperature. Without the surface oxidation of the amine-terminated PDMS and plastic, the two heterogeneous substrates were brought into intimate physical contact and left at room temperature. Subsequently, aminolysis occurred, leading to the generation of a permanent seal via the formation of robust urethane bonds after only 5 min of assembling. Using this method, large-area (10 × 10 cm) bonding was successfully realized. The surface was characterized by contact angle measurements and X-ray photoelectron spectroscopy (XPS) analyses, and the bonding strength was analyzed by performing peel, delamination, leak, and burst tests. The bond strength of the PDMS-polycarbonate (PC) assembly was approximately 409 ± 6.6 kPa, and the assembly withstood the injection of a tremendous amount of liquid with the per-minute injection volume exceeding 2000 times its total internal volume. The thermal stability of the bonded microdevice was confirmed by performing a chamber-type multiplex polymerase chain reaction (PCR) of two major foodborne pathogens - Escherichia coli O157:H7 and Salmonella typhimurium - and assessing the possibility for on-site direct detection of PCR amplicons. This bonding method demonstrated high potential for the stable construction of closed microfluidic systems

  19. A Five-Level H-Bridge STATCOM for an Off-Grid PV Solar Farm under Two Controllers PI and PIλ-MPC Hybrid

    Directory of Open Access Journals (Sweden)

    Onur Ozdal Mengi

    2018-01-01

    Full Text Available Investigations were presented in order to eliminate the reactive power on microgrid loads fed by an off-grid and mid-power photovoltaic solar energy system (PVSES with a static synchronous compensator (STATCOM device. The electric network is specifically characterized by P-Q loads, ambient temperature, and widely variable solar radiation levels. Two main innovations are developed. Firstly, the STATCOM apparatus is a 5-level H-bridge inverter with capacitances as load and must totally compensates the reactive power in the network load. Secondly, this compensation is controlled by a set of fractional PI (PIλ and model predictive control (MPC hybrid. The efficiencies of these controllers were compared with classical PI controllers. Large simulations, without and with reactive power compensation, in steady and transient states, are carried out to underline the merits of the presented works, by performing in the MATLAB-Simulink environment.

  20. Hybrid photovoltaic-diesel-battery systems for remote energy supply

    Energy Technology Data Exchange (ETDEWEB)

    Bopp, G.; Gabler, H.; Kiefer, K.; Preiser, K.; Wiemken, E. [Fraunhofer Institute for Solar Energy Systems ISE, Freiburg (Germany)

    1997-12-31

    Photovoltaic solar generators combined with diesel engines and battery energy storage are powering isolated mountain lodges, information centres in nature parks, isolated farms or dwellings all over Europe. A total of 300000 buildings in Europe are estimated to be not connected to the public grid. This represents a major market potential for photovoltaics, as often photovoltaic power generation is less expensive than a connection to the electric utility. The Fraunhofer Institute for Solar Energy Systems ISE has planned, realized and monitored about 30 hybrid remote energy supply systems with PV generators typically around 5 kW for loads typically around 20 kWh per day. More than one hundred years of operational experience accumulated so far, are a sound foundation on which to draw an interim balance over problems solved and technical questions still under development. Room for further technical development is seen in the domain of system reliability and the reduction of operating costs as well as in the optimization of the utilisation of the electric energy produced by the PV generator. (orig.) 8 refs.

  1. Fusion-fission hybrid reactors

    International Nuclear Information System (INIS)

    Greenspan, E.

    1984-01-01

    This chapter discusses the range of characteristics attainable from hybrid reactor blankets; blanket design considerations; hybrid reactor designs; alternative fuel hybrid reactors; multi-purpose hybrid reactors; and hybrid reactors and the energy economy. Hybrid reactors are driven by a fusion neutron source and include fertile and/or fissile material. The fusion component provides a copious source of fusion neutrons which interact with a subcritical fission component located adjacent to the plasma or pellet chamber. Fissile fuel and/or energy are the main products of hybrid reactors. Topics include high F/M blankets, the fissile (and tritium) breeding ratio, effects of composition on blanket properties, geometrical considerations, power density and first wall loading, variations of blanket properties with irradiation, thermal-hydraulic and mechanical design considerations, safety considerations, tokamak hybrid reactors, tandem-mirror hybrid reactors, inertial confinement hybrid reactors, fusion neutron sources, fissile-fuel and energy production ability, simultaneous production of combustible and fissile fuels, fusion reactors for waste transmutation and fissile breeding, nuclear pumped laser hybrid reactors, Hybrid Fuel Factories (HFFs), and scenarios for hybrid contribution. The appendix offers hybrid reactor fundamentals. Numerous references are provided

  2. Thermally evaporated thin films of SnS for application in solar cell devices

    International Nuclear Information System (INIS)

    Miles, Robert W.; Ogah, Ogah E.; Zoppi, Guillaume; Forbes, Ian

    2009-01-01

    SnS (tin sulphide) is of interest for use as an absorber layer and the wider energy bandgap phases e.g. SnS 2 , Sn 2 S 3 and Sn/S/O alloys of interest as Cd-free buffer layers for use in thin film solar cells. In this work thin films of tin sulphide have been thermally evaporated onto glass and SnO 2 :coated glass substrates with the aim of optimising the properties of the material for use in photovoltaic solar cell device structures. In particular the effects of source temperature, substrate temperature, deposition rate and film thickness on the chemical and physical properties of the layers were investigated. Energy dispersive X-ray analysis was used to determine the film composition, X-ray diffraction to determine the phases present and structure of each phase, transmittance and reflectance versus wavelength measurements to determine the energy bandgap and scanning electron microscopy to observe the surface topology and topography and the properties correlated to the deposition parameters. Using the optimised conditions it is possible to produce thin films of tin sulphide that are pinhole free, conformal to the substrate and that consist of densely packed columnar grains. The composition, phases present and the optical properties of the layers deposited were found to be highly sensitive to the deposition conditions. Energy bandgaps in the range 1.55 eV-1.7 eV were obtained for a film thickness of 0.8 μm, and increasing the film thickness to > 1 μm resulted in a reduction of the energy bandgap to less than 1.55 eV. The applicability of using these films in photovoltaic solar cell device structures is also discussed.

  3. Effect of Cross-Linking on the Mechanical and Thermal Properties of Poly(amidoamine Dendrimer/Poly(vinyl alcohol Hybrid Membranes for CO2 Separation

    Directory of Open Access Journals (Sweden)

    Shuhong Duan

    2014-04-01

    Full Text Available Poly(amidoamine (PAMAM dendrimers were incorporated into cross-linked poly(vinyl alcohol (PVA matrix to improve carbon dioxide (CO2 separation performance at elevated pressures. In our previous studies, PAMAM/PVA hybrid membranes showed high CO2 separation properties from CO2/H2 mixed gases. In this study, three types of organic Ti metal compounds were selected as PVA cross-linkers that were used to prepare PAMAM/cross-linked PVA hybrid membranes. Characterization of the PAMAM/cross-linked PVA hybrid membranes was conducted using nanoindentation and thermogravimetric analyses. The effects of the cross-linker and CO2 partial pressure in the feed gas on CO2 separation performance were discussed. H2O and CO2 sorption of the PAMAM/PVA hybrid membranes were investigated to explain the obtained CO2 separation efficiencies.

  4. Effect of Cross-Linking on the Mechanical and Thermal Properties of Poly(amidoamine) Dendrimer/Poly(vinyl alcohol) Hybrid Membranes for CO2 Separation.

    Science.gov (United States)

    Duan, Shuhong; Kai, Teruhiko; Saito, Takashi; Yamazaki, Kota; Ikeda, Kenichi

    2014-04-08

    Poly(amidoamine) (PAMAM) dendrimers were incorporated into cross-linked poly(vinyl alcohol) (PVA) matrix to improve carbon dioxide (CO2) separation performance at elevated pressures. In our previous studies, PAMAM/PVA hybrid membranes showed high CO2 separation properties from CO2/H2 mixed gases. In this study, three types of organic Ti metal compounds were selected as PVA cross-linkers that were used to prepare PAMAM/cross-linked PVA hybrid membranes. Characterization of the PAMAM/cross-linked PVA hybrid membranes was conducted using nanoindentation and thermogravimetric analyses. The effects of the cross-linker and CO2 partial pressure in the feed gas on CO2 separation performance were discussed. H2O and CO2 sorption of the PAMAM/PVA hybrid membranes were investigated to explain the obtained CO2 separation efficiencies.

  5. Tailoring the magnetic properties and thermal stability of FeSiAl-Al{sub 2}O{sub 3} thin films fabricated by hybrid oblique gradient-composition sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Xiaoxi, E-mail: xiaoxi.zhong@gmail.com [Sichuan Province Key Laboratory of Information Materials and Devices Application, Chengdu University of Information Technology, Chengdu 610225 (China); Phuoc, Nguyen N. [Temasek Laboratories, National University of Singapore, 5A Engineering Drive 2, 117411 Singapore (Singapore); Soh, Wee Tee [Center for Superconducting and Magnetic Materials, Department of Physics, National University of Singapore, 2 Science Drive3, 117542 Singapore (Singapore); Ong, C.K. [Temasek Laboratories, National University of Singapore, 5A Engineering Drive 2, 117411 Singapore (Singapore); Center for Superconducting and Magnetic Materials, Department of Physics, National University of Singapore, 2 Science Drive3, 117542 Singapore (Singapore); Peng, Long; Li, Lezhong [Sichuan Province Key Laboratory of Information Materials and Devices Application, Chengdu University of Information Technology, Chengdu 610225 (China)

    2017-05-01

    In this study, we systematically investigate the dynamic magnetic properties of FeSiAl-Al{sub 2}O{sub 3} thin films fabricated by hybrid oblique gradient-composition sputtering technique with respect to temperature ranging from 300 K to 420 K. The magnetic anisotropy field H{sub K} and ferromagnetic resonance frequency f{sub FMR} can be tuned from 14.06 to 110.18 Oe and 1.05–3.05 GHz respectively, by changing the oblique angle, which can be interpreted in terms of the contribution of stress-induced anisotropy and shape anisotropy. In addition, the thermal stability of FeSiAl-Al{sub 2}O{sub 3} films in terms of magnetic anisotropy H{sub K} and ferromagnetic resonance frequency f{sub FMR} are enhanced with the increase of oblique angle up to 35° while the thermal stability of effective Gilbert damping factor α{sub eff} and the maximum imaginary permeability μ’’{sub max} are improved with the increase of oblique angle up to 45°. - Highlights: • We prepared FeSiAl-based thin films using hybrid oblique gradient-composition deposition technique. • The microwave properties of FeSiAl-based thin films were systematically studied. • The thermal stability of microwave properties of FeSiAl-based films was studied. • The permeabilities were got using shorted micro-strip transmission-line perturbation. • The thermal stability of properties we studied is relatively good.

  6. Interfacial scanning tunneling spectroscopy (STS) of chalcogenide/metal hybrid nanostructure

    Energy Technology Data Exchange (ETDEWEB)

    Saad, Mahmoud M.; Abdallah, Tamer [Physics Department, Faculty of Science, Ain Shams University, Abbassia, Cairo (Egypt); Easawi, Khalid; Negm, Sohair [Department of Physics and Mathematics, Faculty of Engineering (Shoubra), Benha University (Egypt); Talaat, Hassan, E-mail: hassantalaat@hotmail.com [Physics Department, Faculty of Science, Ain Shams University, Abbassia, Cairo (Egypt)

    2015-05-15

    Graphical abstract: - Highlights: • Comparing band gaps values obtained optically with STS. • Comparing direct imaging with calculated dimensions. • STS determination of the interfacial band bending of metal/chalcogenide. - Abstract: The electronic structure at the interface of chalcogenide/metal hybrid nanostructure (CdSe–Au tipped) had been studied by UHV scanning tunneling spectroscopy (STS) technique at room temperature. This nanostructure was synthesized by a phase transfer chemical method. The optical absorption of this hybrid nanostructure was recorded, and the application of the effective mass approximation (EMA) model gave dimensions that were confirmed by the direct measurements using the scanning tunneling microscopy (STM) as well as the high-resolution transmission electron microscope (HRTEM). The energy band gap obtained by STS agrees with the values obtained from the optical absorption. Moreover, the STS at the interface of CdSe–Au tipped hybrid nanostructure between CdSe of size about 4.1 ± 0.19 nm and Au tip of size about 3.5 ± 0.29 nm shows a band bending about 0.18 ± 0.03 eV in CdSe down in the direction of the interface. Such a result gives a direct observation of the electron accumulation at the interface of CdSe–Au tipped hybrid nanostructure, consistent with its energy band diagram. The presence of the electron accumulation at the interface of chalcogenides with metals has an important implication for hybrid nanoelectronic devices and the newly developed plasmon/chalcogenide photovoltaic solar energy conversion.

  7. Simulation of the performance and economical study of a hybrid thermal desalination (solar and natural gas); Simulacao do desempenho e estudo economico de um dessalinizador hibrido (solar e gas natural)

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Maria E.V. da; Coutinho, Lecimara D.E.; Soares, Bruno de L. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil); Schwarzer, Klemens [Universidade de Ciencias Aplicadas de Aachen (Germany); Campos, Michel F. [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2004-07-01

    This article presents a simulation of the performance and the results of an economic study of a hybrid thermal desalination equipment to produce drinkable water using solar energy and natural gas at its energy sources. The components of the desalination equipment are two solar flat plate collectors with reflectors, a natural gas burner, and a desalination tower. A piping circuit connects the tower to the collectors and the burner. In this circuit, a fluid transports heat from the thermal sources (collectors or burner) to the salty water in the first stage of the tower. When the salty water receives heat, it warms up and evaporates. The vapor produced flows up the bottom walls of the next stage, where it condenses, as it transfers the phase change heat to the water in this upper stage. The condensate flows in lateral channels to be collected outside the tower. Experimental measurements results obtained for a desalination unit with 4m{sup 2} of collector area and a seven stage tower, and the natural gas properties were used in the calculation. In the economic study, fabrication, installation, and maintenance costs were included. The results also show the water daily production for solar and hybrid. (author)

  8. Guidelines for safety system in the plant for photovoltaic solar cells applications feeded poisonous H{sub 2}Se; Linee guida per la realizzazione di un sistema di sicurezza per un impianto di selenizzazione impiegante gas tossico H{sub 2}Se

    Energy Technology Data Exchange (ETDEWEB)

    Pellegrino, M; Agati, A [ENEA, Centro Ricerche Casaccia, Portici. Naples (Italy). Dip. Energia

    1996-12-01

    The report aims at the description of safety system which has been realized and provided at the ENEA (Italian Agency for New Technologies, Energy and the Environment)`s Research Center, located in Portici, to the plant for the formation of the dyselenide and/or dysulphide of copper and indium CuIn (Se,S){sub 2} for photovoltaic solar cells applications. The plant is a diffusion furnace that has to be feeded with gases such as poisonous H{sub 2}S or the very toxic H{sub 2}Se, whose Threshold Level Values are respectively of 10-p.p.m. (parts per millions) and 50 p.p.b. (parts per billions), as well as the flammable and explodible H{sub 2}; the TLV is the maximum concentration value of a gas to which a worker can be exposed during its working shift, i.e., eight hours a day for five days a week for thirty five years, without any any adverse effects on his health. The description of the scientific results obtained on the field of the research with the use of that facility is beyond the scope of the report, as well as it has been intended as an handbook for the safe toxic gas handling, some example of which may be found on the specialized literature, but only to provide some guidelines for the realization of such a system.

  9. Preparation and optical and electrical evaluation of bulk SiO2 sonogel hybrid composites and vacuum thermal evaporated thin films prepared from molecular materials derived from (Fe, Co) metallic phthalocyanines and 1,8 dihydroxiantraquinone compounds

    International Nuclear Information System (INIS)

    Sanchez Vergara, Maria Elena; Morales-Saavedra, Omar G.; Ontiveros-Barrera, Fernando G.; Torres-Zuniga, Vicente; Ortega-Martinez, Roberto; Ortiz Rebollo, Armando

    2009-01-01

    Semiconducting molecular material of PcFe(CN)L1 and PcCo(CN)L1 (L1 = 1,8 dihydroxianthraquinone), PcFe(CN)L2 and PcCo(CN)L2 (L2 = double potassium salt of 1,8 dihydroxianthraquinone) have been successfully used to prepare thin film and bulk sol-gel hybrid optical materials. These samples were developed according to the vacuum thermal evaporation technique and the catalyst-free sonogel route, respectively. Thin films samples were deposited on Corning glass substrates and crystalline silicon wafers and were characterized by infrared (FTIR), Raman and ultraviolet-visible (UV-vis) spectroscopies. IR-spectroscopy and Raman studies unambiguously confirmed that the molecular material thin films exhibit the same intra-molecular bonds, which suggests that the thermal evaporation process does not alter these bonds significantly. These results show that it is possible to deposit molecular materials of PcFe(CN)L2 and PcCo(CN)L2 on Corning glass substrates and silicon wafers. From the UV-vis studies the optical band gap (E g ) was evaluated. The effect of temperature on conductivity was also evaluated in these samples. Finally, the studied molecular systems dissolved at different concentrations in tetrahydrofuran (THF) were successfully embedded into a highly pure SiO 2 sonogel network generated via sonochemical reactions to form several solid state, optically active sol-gel hybrid glasses. By this method, homogeneous and stable hybrid monoliths suitable for optical characterization can be produced. The linear optical properties of these amorphous bulk structures were determined by the Brewster angle method and by absorption-, Raman- and photoluminescent (PL)-spectroscopies, respectively

  10. Preparation and optical and electrical evaluation of bulk SiO{sub 2} sonogel hybrid composites and vacuum thermal evaporated thin films prepared from molecular materials derived from (Fe, Co) metallic phthalocyanines and 1,8 dihydroxiantraquinone compounds

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Vergara, Maria Elena [Coordinacion de Ingenieria Mecatronica, Facultad de Ingenieria, Universidad Anahuac Mexico Norte. Avenida Universidad Anahuac 46, Col. Lomas Anahuac, 52786 Huixquilucan, Estado de Mexico (Mexico); Morales-Saavedra, Omar G. [Universidad Nacional Autonoma de Mexico, Centro de Ciencias Aplicadas y Desarrollo Tecnologico, CCADET-UNAM, A.P. 70-186, Coyoacan, 04510 Mexico, D.F. (Mexico)], E-mail: omar.morales@ccadet.unam.mx; Ontiveros-Barrera, Fernando G.; Torres-Zuniga, Vicente; Ortega-Martinez, Roberto [Universidad Nacional Autonoma de Mexico, Centro de Ciencias Aplicadas y Desarrollo Tecnologico, CCADET-UNAM, A.P. 70-186, Coyoacan, 04510 Mexico, D.F. (Mexico); Ortiz Rebollo, Armando [Universidad Nacional Autonoma de Mexico, Instituto de Investigaciones en Materiales, IIM-UNAM, A.P. 70-360, Coyoacan, 04510 Mexico, D.F. (Mexico)

    2009-02-25

    Semiconducting molecular material of PcFe(CN)L1 and PcCo(CN)L1 (L1 = 1,8 dihydroxianthraquinone), PcFe(CN)L2 and PcCo(CN)L2 (L2 = double potassium salt of 1,8 dihydroxianthraquinone) have been successfully used to prepare thin film and bulk sol-gel hybrid optical materials. These samples were developed according to the vacuum thermal evaporation technique and the catalyst-free sonogel route, respectively. Thin films samples were deposited on Corning glass substrates and crystalline silicon wafers and were characterized by infrared (FTIR), Raman and ultraviolet-visible (UV-vis) spectroscopies. IR-spectroscopy and Raman studies unambiguously confirmed that the molecular material thin films exhibit the same intra-molecular bonds, which suggests that the thermal evaporation process does not alter these bonds significantly. These results show that it is possible to deposit molecular materials of PcFe(CN)L2 and PcCo(CN)L2 on Corning glass substrates and silicon wafers. From the UV-vis studies the optical band gap (E{sub g}) was evaluated. The effect of temperature on conductivity was also evaluated in these samples. Finally, the studied molecular systems dissolved at different concentrations in tetrahydrofuran (THF) were successfully embedded into a highly pure SiO{sub 2} sonogel network generated via sonochemical reactions to form several solid state, optically active sol-gel hybrid glasses. By this method, homogeneous and stable hybrid monoliths suitable for optical characterization can be produced. The linear optical properties of these amorphous bulk structures were determined by the Brewster angle method and by absorption-, Raman- and photoluminescent (PL)-spectroscopies, respectively.

  11. Volumetric solar thermal receiver principles and technological approach

    International Nuclear Information System (INIS)

    Sagie, D.; Gruntman, S.; Taragan, E.; Danino, M.; Weiss, S.; Mimon, Y.

    1996-01-01

    Solar energy has received much interest in recent years, being a clean free of pollution or other environmental dotage), and inexhaustible energy source. It is also considered safer than some other non conventional energy sources (like nuclear energy). The interest in solar energy is motivated mainly by the growing awareness of the environmental problems associated with the use of . conventional keels. However, solar energy may become a serious alternative only if it can be used efficiently in major energy consuming industries (like the chemical industry), or be used for electricity generation. Those facilities are nowadays solely depend on fossil fuels as the prime source of energy . The solar energy, reaches file Earth as radiation, can be utilized either by direct quantum conversion using photo-voltaic solar cells, or by converting the radiation into thermal energy, to be used directly for heating, or to feed a thermal to electric converting cycle. Alter three decades of huge spending on the development of photo-voltaic systems those devices are commercially competitive only on very small energy scale, while solar thermal commercial applications are evident. The prominent examples are the domestic heating water receivers (direct thermal), and LUZ International electricity generation plants which are currently operated on a commercial basis, supplying 80 MWe per plant. Direct thermal exploitation of solar energy is naturally more efficient than converting to electricity but is limited to specific applications and locations especially since thermal storage at high temperature is not commercially viable. Efficient electricity production at competitive price is clearly the biggest opportunity for solar energy. (authors)

  12. The development of a volumetric solar thermal receiver: an overview

    International Nuclear Information System (INIS)

    Sagie, D.

    1996-01-01

    Solar energy has received much interest in recent years, being a clean (free of pollution or other environmental damage) and inexhaustible energy source. It is also considered safer than some other non conventional energy sources (like nuclear energy). The interest in solar energy is motivated mainly by the growing awareness of the environmental problems associated with the use of conventional fuels. However, solar energy may become a serious alternative only if it can be used efficiently in major energy consuming industries (like the chemical industry), or be used for electricity generation. Those facilities are nowadays solely dependent on fossil fuels as the prime source of energy. The solar energy, reaching the earth in the form of radiation, can be utilized either by direct quantum conversion using photo-voltaic solar cells, or by converting the radiation into thermal energy, to be used directly for heating, or to feed a thermal to electric converting cycle. After three decades of huge spending on the development of photo-voltaic systems those devices are commercially competitive only on a very small energy scale, while solar thermal commercial applications are more attractive. Prominent examples are the domestic heating water receivers (direct thermal), and LUZ International electricity generation plants which are currently operated on a commercial basis, supplying 80 MWe per plant. Direct thermal exploitation of solar energy is naturally more efficient than converting to electricity, but is limited to specific applications and locations especially since thermal storage at high temperature is not commercially viable. Efficient electricity production at a competitive price is clearly the biggest opportunity for solar energy . (author)

  13. Annual measured and simulated thermal performance analysis of a hybrid solar district heating plant with flat plate collectors and parabolic trough collectors in series

    DEFF Research Database (Denmark)

    Tian, Zhiyong; Perers, Bengt; Furbo, Simon

    2017-01-01

    Flat plate collectors have relatively low efficiency at the typical supply temperatures of district heating networks (70–95 °C). Parabolic trough collectors retain their high efficiency at these temperatures. To maximize the advantages of flat plate collectors and parabolic trough collectors in l...... for this type of hybrid solar district heating plants with flat plate collectors and parabolic trough collectors in the Nordic region, but also introduce a novel design concept of solar district heating plants to other high solar radiation areas....... in large solar heating plants for a district heating network, a hybrid solar collector field with 5960 m2 flat plate collectors and 4039 m2 parabolic trough collectors in series was constructed in Taars, Denmark. The design principle is that the flat plate collectors preheat the return water from...

  14. Doubts about hybrids

    International Nuclear Information System (INIS)

    Anon.

    1982-01-01

    The natural draught wet cooling tower with a height of 160 m is considerably taller than the 80 m high hybrid cooling tower, but the latter has a considerably larger diameter. Spray losses for both types are about 4.5 kg/sec for a thermal output of 2500 MW. Apart from the pump load, the natural cooling tower requires no power. Apart from higher pump loads, the hybrid cooling tower requires power for the fans. The energy demand for this purpose is 1.5 to 3% of the nett powerstation output. For the Isar 2 nuclear powerstation this would mean a reduction in puput of about 35 MW. (orig.) [de

  15. Study of hybrid laser / MAG welding process: characterization of the geometry and the hydrodynamics of the melt pool and development of a 3D thermal model

    International Nuclear Information System (INIS)

    Le Guen, E.

    2010-11-01

    Hybrid laser/MIG-MAG welding shows high advantages compared to laser welding or GMAW arc welding used separately. Thanks to this process, higher productivity can be gained through higher welding speed, higher squeeze tolerance moreover possible improvement of the metallurgical properties of the weld seam can be obtained. However, many operating parameters have to be set up in order to achieve optimal process. The complex physical phenomena, which govern welding process, have to be understood in order to use efficiently this technique in mass production. Understanding of these phenomena is also necessary to program numerical simulations which fit to this process. In the first step, experimental studies have been carried out with GMAW, laser and hybrid welding on samples of S355 steel. Influence of operating parameters has been analyzed through films performed with speed camera and macro-graphies of weld seam cross section. Surface deformations of the melt pool, induced by the arc pressure, weld pool length, droplet detachment and welding speed, have been analyzed precisely from images of the surface melt pool. In a second step, a numerical model was developed using the COMSOL Multiphysics software for MAG, laser and hybrid laser/MAG welding processes. A 3D quasi-stationary model has been calculated from the temperature field within the metal. The originality of the MAG and hybrid model lies in the prediction of the melt pool surface profile used to determine the 3D geometry, by taking into account the material input. The influence of different parameters such as arc power and speed welding on the efficiency as well as the distribution radius of the arc power and the arc pressure are analyzed through validations with different experimental results and different calculation configurations. (author)

  16. Filamentation instability of lower hybrid waves in a plasma

    International Nuclear Information System (INIS)

    Kaw, P.K.

    1976-02-01

    It is shown that a strong lower hybrid wave is modulationally unstable to perturbations propagating along its own wave vector. The instability relies critically on the finite thermal corrections to the lower hybrid dispersion relation

  17. Hybrid spacecraft attitude control system

    Directory of Open Access Journals (Sweden)

    Renuganth Varatharajoo

    2016-02-01

    Full Text Available The hybrid subsystem design could be an attractive approach for futurespacecraft to cope with their demands. The idea of combining theconventional Attitude Control System and the Electrical Power System ispresented in this article. The Combined Energy and Attitude ControlSystem (CEACS consisting of a double counter rotating flywheel assemblyis investigated for small satellites in this article. Another hybrid systemincorporating the conventional Attitude Control System into the ThermalControl System forming the Combined Attitude and Thermal ControlSystem (CATCS consisting of a "fluid wheel" and permanent magnets isalso investigated for small satellites herein. The governing equationsdescribing both these novel hybrid subsystems are presented and theironboard architectures are numerically tested. Both the investigated novelhybrid spacecraft subsystems comply with the reference missionrequirements.The hybrid subsystem design could be an attractive approach for futurespacecraft to cope with their demands. The idea of combining theconventional Attitude Control System and the Electrical Power System ispresented in this article. The Combined Energy and Attitude ControlSystem (CEACS consisting of a double counter rotating flywheel assemblyis investigated for small satellites in this article. Another hybrid systemincorporating the conventional Attitude Control System into the ThermalControl System forming the Combined Attitude and Thermal ControlSystem (CATCS consisting of a "fluid wheel" and permanent magnets isalso investigated for small satellites herein. The governing equationsdescribing both these novel hybrid subsystems are presented and theironboard architectures are numerically tested. Both the investigated novelhybrid spacecraft subsystems comply with the reference missionrequirements.

  18. Systems for hybrid cars

    Science.gov (United States)

    Bitsche, Otmar; Gutmann, Guenter

    Not only sharp competition but also legislation are pushing development of hybrid drive trains. Based on conventional internal combustion engine (ICE) vehicles, these drive trains offer a wide range of benefits from reduced fuel consumption and emission to multifaceted performance improvements. Hybrid electric drive trains may also facilitate the introduction of fuel cells (FC). The battery is the key component for all hybrid drive trains, as it dominates cost and performance issues. The selection of the right battery technology for the specific automotive application is an important task with an impact on costs of development and use. Safety, power, and high cycle life are a must for all hybrid applications. The greatest pressure to reduce cost is in soft hybrids, where lead-acid embedded in a considerate management presents the cheapest solution, with a considerable improvement in performance needed. From mild to full hybridization, an improvement in specific power makes higher costs more acceptable, provided that the battery's service life is equivalent to the vehicle's lifetime. Today, this is proven for the nickel-metal hydride system. Lithium ion batteries, which make use of a multiple safety concept, and with some development anticipated, provide even better prospects in terms of performance and costs. Also, their scalability permits their application in battery electric vehicles—the basis for better performance and enhanced user acceptance. Development targets for the batteries are discussed with a focus on system aspects such as electrical and thermal management and safety.

  19. In-situ hybrid study of thermal behaviour of Znsbnd Ni and Znsbnd Nisbnd Al2O3 nanocrystallite thin films induced TEA/MEA by electrocodeposition

    Science.gov (United States)

    Abdulwahab, M.; Fayomi, O. S. I.; Popoola, A. P. I.; Dodo, M. R.

    Our present investigation focuses on the thermal stability of already developed electroforms of Znsbnd Ni and Znsbnd Nisbnd Al2O3 thin films induced with triethylamine (TEA) and monoethylamine (MEA) as surfactant by electrocodeposition on mild steel substrate with the aim to re-examine its micro-hardness and degradation behaviour in static sodium chloride solution. In the event, the samples were thermally treated at 200 °C and air cooled. The results obtained showed that the developed composites are thermally stable with hardness value of the Znsbnd Nisbnd Al2O3 coated; 185 Hv increased to 190.5 Hv indicating a 2.89% improvement. Noticeably, in the Znsbnd Ni coatings, a decrease in the hardness with 26.67% was observed. The oxidation resistance was however favored for both composites.

  20. Matching indices taking the dynamic hybrid electrical and thermal grids information into account for the decision-making of nZEB on-site renewable energy systems

    International Nuclear Information System (INIS)

    Cao, Sunliang; Sirén, Kai

    2015-01-01

    Highlights: • Use dynamic hourly-based grid information (PEF/CEF/tariffs) in nZEB control. • Hourly dynamic primary energy factor, CO 2 factor and tariffs for hybrid grids. • Methodology which links the on-site matching with dynamic grid information. • Multi-objective control indicators reflects both matching and grid information. • The influence of the dynamic grid information on the energy/environment/cost. - Abstract: Future nearly-zero energy buildings (nZEBs) will be involved with the twofold problem of on-site matching and hybrid–grid interactions. Theoretically, the hybrid grids’ information is dynamic, such as primary energy factors, equivalent CO 2 emission factors, and grid tariffs. Regarding primary energy consumption, equivalent CO 2 emissions or the grid cost of the nZEB, the significance of specific aspects of the matching capability, such as on-site energy faction (OEF) and on-site energy matching (OEM), will also become dynamic and variable with respect to the evolution of the grid information. Therefore, the primary goal is to develop a methodology as a multi-objective control criterion for the nZEB energy system, which can reflect both the on-site matching capability and dynamic grid information of environmental or economic impacts. The developed methodology is to quantitatively link the dynamic grid information with the weighting factors of the weighted matching index (WMI), following the monotone relationships between the extended matching indices and grid information. The methodology is implemented in this study to control an nZEB energy system with hybrid grid connections. The results show that the developed methodology can seek an optimised balance between the objectives of maximising the matching capability and minimising the environmental/economic load

  1. A hydrogen production experiment by the thermo-chemical and electrolytic hybrid hydrogen production in lower temperature range. System viability and preliminary thermal efficiency estimation

    International Nuclear Information System (INIS)

    Takai, Toshihide; Nakagiri, Toshio; Inagaki, Yoshiyuki

    2008-10-01

    A new experimental apparatus by the thermo-chemical and electrolytic Hybrid-Hydrogen production in Lower Temperature range (HHLT) was developed and hydrogen production experiment was performed to confirm the system operability. Hydrogen production efficiency was estimated and technical problems were clarified through the experimental results. Stable operation of the SO 3 electrolysis cell and the sulfur dioxide solution electrolysis cell were confirmed during experimental operation and any damage which would be affected solid operation was not detected under post operation inspection. To improve hydrogen production efficiency, it was found that the reduction of sulfuric acid circulation and the decrease in the cell voltage were key issues. (author)

  2. Influence of ZrO2 nanoparticles and thermal treatment on the properties of PMMA/ZrO2 hybrid coatings

    International Nuclear Information System (INIS)

    Reyes-Acosta, M.A.; Torres-Huerta, A.M.; Domínguez-Crespo, M.A.; Flores-Vela, A.I.; Dorantes-Rosales, H.J.; Ramírez-Meneses, E.

    2015-01-01

    Highlights: • PMMA/ZrO 2 nanocomposites were prepared by melt blending in a single screw extruder. • The nanoparticles of m-, t-ZrO 2 were successfully synthesized using sol–gel technique. • The prepared PMMA/ZrO 2 nanocomposites have better UV protection than pure PMMA. • The thermal stability of the PMMA increases with low amount of ZrO 2 nanoparticles. • PMMA/ZrO 2 nanocomposites show superior values of elastic modulus and hardness. - Abstract: In this work, ZrO 2 nanoparticles were synthesized by the sol–gel method, treated thermally at different temperatures (400, 600 and 800 °C), and added to a polymer matrix in two different weight percentages (0.5 and 1) by single screw extrusion in order to determine the influence of these parameters on the thermal stability and UV radiation resistance of PMMA/ZrO 2 composites. Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), X-ray diffraction (XRD), transmission electron microscopy (TEM), confocal laser scanning microscopy (CLSM), ultraviolet–visible spectroscopy (UV–Vis), thermogravimetric analysis (TGA) and nanoindentation techniques were used to evaluate the structural, morphological, optical, thermal and mechanical properties of as-prepared composites. The average crystallite sizes for ZrO 2 sintered at 600 and 800 °C were about 17 and 26 nm, respectively. It was found that the incorporation of a low percentage of ZrO 2 nanoparticles increased the thermal properties of PMMA as well as its hardness and elastic modulus. The degradation temperature at 10 wt.% loss of the PMMA/ZrO 2 (0.5 wt.%, 400 °C) nanocomposite was approximately 48 °C higher than that of pure PMMA. The absorption in the UV region was increased according to the ZrO 2 heat treatment temperature and amount added to the polymer matrix

  3. Hybrid Dark Matter

    OpenAIRE

    Chao, Wei

    2018-01-01

    Dark matter can be produced in the early universe via the freeze-in or freeze-out mechanisms. Both scenarios were investigated in references, but the production of dark matters via the combination of these two mechanisms are not addressed. In this paper we propose a hybrid dark matter model where dark matters have two components with one component produced thermally and the other one produced non-thermally. We present for the first time the analytical calculation for the relic abundance of th...

  4. Hybrid spacecraft attitude control system

    OpenAIRE

    Renuganth Varatharajoo; Ramly Ajir; Tamizi Ahmad

    2016-01-01

    The hybrid subsystem design could be an attractive approach for futurespacecraft to cope with their demands. The idea of combining theconventional Attitude Control System and the Electrical Power System ispresented in this article. The Combined Energy and Attitude ControlSystem (CEACS) consisting of a double counter rotating flywheel assemblyis investigated for small satellites in this article. Another hybrid systemincorporating the conventional Attitude Control System into the ThermalControl...

  5. Performance Analysis of a Photovoltaic-Thermal Integrated System

    International Nuclear Information System (INIS)

    Radziemska, E.

    2009-01-01

    The present commercial photovoltaic solar cells (PV) converts solar energy into electricity with a relatively low efficiency, less than 20%. More than 80% of the absorbed solar energy is dumped to the surroundings again after photovoltaic conversion. Hybrid PV/T systems consist of PV modules coupled with the heat extraction devices. The PV/T collectors generate electric power and heat simultaneously. Stabilizing temperature of photovoltaic modules at low level is highly desirable to obtain efficiency increase. The total efficiency of 60-80% can be achieved with the whole PV/T system provided that the T system is operated near ambient temperature. The value of the low-T heat energy is typically much smaller than the value of the PV electricity. The PV/T systems can exist in many designs, but the most common models are with the use of water or air as a working fuid. Efficiency is the most valuable parameter for the economic analysis. It has substantial meaning in the case of installations with great nominal power, as air-cooled Building Integrated Photovoltaic Systems (BIPV). In this paper the performance analysis of a hybrid PV/T system is presented: an energetic analysis as well as an exergetic analysis. Exergy is always destroyed when a process involves a temperature change. This destruction is proportional to the entropy increase of the system together with its surroundings the destroyed exergy has been called energy. Exergy analysis identifies the location, the magnitude, and the sources of thermodynamic inefficiencies in a system. This information, which cannot be provided by other means (e.g., an energy analysis), is very useful for the improvement and cost-effectiveness of the system. Calculations were carried out for the tested water-cooled ASE-100-DGL-SM Solar watt module.

  6. Performance Analysis of a Photovoltaic-Thermal Integrated System

    Directory of Open Access Journals (Sweden)

    Ewa Radziemska

    2009-01-01

    Full Text Available The present commercial photovoltaic solar cells (PV converts solar energy into electricity with a relatively low efficiency, less than 20%. More than 80% of the absorbed solar energy is dumped to the surroundings again after photovoltaic conversion. Hybrid PV/T systems consist of PV modules coupled with the heat extraction devices. The PV/T collectors generate electric power and heat simultaneously. Stabilizing temperature of photovoltaic modules at low level is higly desirable to obtain efficiency increase. The total efficiency of 60–80% can be achieved with the whole PV/T system provided that the T system is operated near ambient temperature. The value of the low-T heat energy is typically much smaller than the value of the PV electricity. The PV/T systems can exist in many designs, but the most common models are with the use of water or air as a working fuid. Efficiency is the most valuable parameter for the economic analysis. It has substantial meaning in the case of installations with great nominal power, as air-cooled Building Integrated Photovoltaic Systems (BIPV. In this paper the performance analysis of a hybrid PV/T system is presented: an energetic analysis as well as an exergetic analysis. Exergy is always destroyed when a process involves a temperature change. This destruction is proportional to the entropy increase of the system together with its surroundings—the destroyed exergy has been called anergy. Exergy analysis identifies the location, the magnitude, and the sources of thermodynamic inefficiences in a system. This information, which cannot be provided by other means (e.g., an energy analysis, is very useful for the improvement and cost-effictiveness of the system. Calculations were carried out for the tested water-cooled ASE-100-DGL-SM Solarwatt module.

  7. The challenge of hybridization

    CERN Document Server

    Caccia, Massimo

    2000-01-01

    Hybridization of pixel detector systems has to satisfy tight requirements: high yield, long term reliability, mechanical stability, thermal compliance and robustness have to go together with low passive mass added to the system, radiation hardness, flexibility in the technology end eventually low cost. The current technologies for the interconnection of the front-end chips and the sensor are reviewed and compared, together with the solutions for the interface to the far-end electronics.

  8. Laser driven fusion fission hybrids

    International Nuclear Information System (INIS)

    Hansen, L.F.; Maniscalco, J.A.

    1977-11-01

    The role of the fusion-fission hybrid reactor (FFHR) as a fissile fuel and/or power producer is discussed. As long range options to supply the world energy needs, hybrid-fueled thermal-burner reactors are compared to liquid metal fast breeder reactors (LMFBR). A discussion of different fuel cycles (thorium, depleted uranium, and spent fuel) is presented in order to compare the energy multiplication, the production of fissile fuel, the laser efficiency and pellet gain requirements of the hybrid reactor. Lawrence Livermore Laboratory (LLL) has collaborated with Bechtel Corporation and with Westinghouse in two engineering design studies of laser fusion driven hybrid power plants. The hybrid designs which have resulted from these two studies are briefly described and analyzed by considering operational parameters, such as energy multiplication, power density, burn-up and plutonium production as a function time

  9. Effect of Thermal and Structural Disorder on the Electronic Structure of Hybrid Perovskite Semiconductor CH3NH3PbI3.

    Science.gov (United States)

    Singh, Shivam; Li, Cheng; Panzer, Fabian; Narasimhan, K L; Graeser, Anna; Gujar, Tanaji P; Köhler, Anna; Thelakkat, Mukundan; Huettner, Sven; Kabra, Dinesh

    2016-08-04

    In this Letter, we investigate the temperature dependence of the optical properties of methylammonium lead iodide (MAPbI3 = CH3NH3PbI3) from room temperature to 6 K. In both the tetragonal (T > 163 K) and the orthorhombic (T photoluminescence (PL) measurements) decreases with decrease in temperature, in contrast to what is normally seen for many inorganic semiconductors, such as Si, GaAs, GaN, etc. We show that in the perovskites reported here, the temperature coefficient of thermal expansion is large and accounts for the positive temperature coefficient of the band gap. A detailed analysis of the exciton line width allows us to distinguish between static and dynamic disorder. The low-energy tail of the exciton absorption is reminiscent of Urbach absorption. The Urbach energy is a measure of the disorder, which is modeled using thermal and static disorder for both the phases separately. The static disorder component, manifested in the exciton line width at low temperature, is small. Above 60 K, thermal disorder increases the line width. Both these features are a measure of the high crystal quality and low disorder of the perovskite films even though they are produced from solution.

  10. Influence of ZrO{sub 2} nanoparticles and thermal treatment on the properties of PMMA/ZrO{sub 2} hybrid coatings

    Energy Technology Data Exchange (ETDEWEB)

    Reyes-Acosta, M.A. [Instituto Politécnico Nacional, CICATA-Altamira, CIAMS (Mexico); Instituto Politécnico Nacional, CICATA-Altamira, Km 14.5 Carretera Tampico-Puerto Industrial Altamira, C.P. 89600 Altamira, Tamps. (Mexico); Torres-Huerta, A.M., E-mail: atorresh@ipn.mx [Instituto Politécnico Nacional, CICATA-Altamira, Km 14.5 Carretera Tampico-Puerto Industrial Altamira, C.P. 89600 Altamira, Tamps. (Mexico); Domínguez-Crespo, M.A. [Instituto Politécnico Nacional, CICATA-Altamira, Km 14.5 Carretera Tampico-Puerto Industrial Altamira, C.P. 89600 Altamira, Tamps. (Mexico); Flores-Vela, A.I. [Instituto Politécnico Nacional, CMP+L, Av. Acueducto s/n, Barrio La Laguna, Col. Ticomán, C.P. 07340 México D.F. (Mexico); Dorantes-Rosales, H.J. [Instituto Politécnico Nacional, SEPI-ESIQIE, Departamento de Metalurgia, C.P. 07738 México D.F. (Mexico); Ramírez-Meneses, E. [Departamento de Ingeniería y Ciencias Químicas, Universidad Iberoamericana, Prolongación Paseo de la Reforma 880, Lomas de Santa Fe, Distrito Federal C.P. 01219 (Mexico)

    2015-09-15

    Highlights: • PMMA/ZrO{sub 2} nanocomposites were prepared by melt blending in a single screw extruder. • The nanoparticles of m-, t-ZrO{sub 2} were successfully synthesized using sol–gel technique. • The prepared PMMA/ZrO{sub 2} nanocomposites have better UV protection than pure PMMA. • The thermal stability of the PMMA increases with low amount of ZrO{sub 2} nanoparticles. • PMMA/ZrO{sub 2} nanocomposites show superior values of elastic modulus and hardness. - Abstract: In this work, ZrO{sub 2} nanoparticles were synthesized by the sol–gel method, treated thermally at different temperatures (400, 600 and 800 °C), and added to a polymer matrix in two different weight percentages (0.5 and 1) by single screw extrusion in order to determine the influence of these parameters on the thermal stability and UV radiation resistance of PMMA/ZrO{sub 2} composites. Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), X-ray diffraction (XRD), transmission electron microscopy (TEM), confocal laser scanning microscopy (CLSM), ultraviolet–visible spectroscopy (UV–Vis), thermogravimetric analysis (TGA) and nanoindentation techniques were used to evaluate the structural, morphological, optical, thermal and mechanical properties of as-prepared composites. The average crystallite sizes for ZrO{sub 2} sintered at 600 and 800 °C were about 17 and 26 nm, respectively. It was found that the incorporation of a low percentage of ZrO{sub 2} nanoparticles increased the thermal properties of PMMA as well as its hardness and elastic modulus. The degradation temperature at 10 wt.% loss of the PMMA/ZrO{sub 2} (0.5 wt.%, 400 °C) nanocomposite was approximately 48 °C higher than that of pure PMMA. The absorption in the UV region was increased according to the ZrO{sub 2} heat treatment temperature and amount added to the polymer matrix.

  11. On the Optimal Thermal Management of Hybrid-Electric Vehicles with Heat Recovery Systems Sur le thermo-management optimal d’un véhicule électrique hybride avec un système de récupération de chaleur

    Directory of Open Access Journals (Sweden)

    Merz F.

    2012-09-01

    Full Text Available A general framework to combine optimal energy management (powertrain supervisory control and thermal management in Hybrid Electric Vehicles (HEV is presented. A HEV system with engine exhaust aftertreatment and exhaust heat recovery system is simulated under various scenarios, including warm and cold start. Optimal strategies are derived from Pontryagin Minimum Principle (PMP. The concept of fuel equivalent of thermal energy variations – similar to the equivalence factors for battery energy of standard Equivalent Consumption Minimization Strategy (ECMS – is introduced. The PMP-based strategies are compared with a heuristic, rule-based strategy. The benefits in fuel economy and reduction of pollutant emissions that are obtained for several scenarios are very promising. Une approche généralisée pour combiner la gestion de l’énergie (supervision du groupe motopropulseur et le thermo-management dans les véhicules hybrides électriques est proposée. Un système hybride incluant le post-traitement des polluants et un système de récupération de la chaleur à l’échappement du moteur thermique est simulé pour plusieurs scénarii, y compris le cas de départ à froid. Des stratégies de gestion de l’énergie optimales sont dérivées à partir du Principe de Minimum de Pontriaguine (PMP. Inspirée par les facteurs d’équivalence pour la consommation électrique que l’on retrouve dans la stratégie ECMS, la notion d’équivalent en carburant des flux d’énergie thermique est introduite. Les stratégies dérivées du PMP sont comparées avec une stratégie heuristique basée sur des règles. Les bénéfices en termes d’économies de carburant et réduction des émissions polluantes que l’on trouve pour différents scénarii sont encourageantes.

  12. A hybrid strain and thermal energy harvester based on an infra-red sensitive Er3+ modified poly(vinylidene fluoride) ferroelectret structure.

    Science.gov (United States)

    Ghosh, Sujoy Kumar; Xie, Mengying; Bowen, Christopher Rhys; Davies, Philip R; Morgan, David J; Mandal, Dipankar

    2017-12-01

    In this paper, a novel infra-red (IR) sensitive Er 3+ modified poly(vinylidene fluoride) (PVDF) (Er-PVDF) film is developed for converting both mechanical and thermal energies into useful electrical power. The addition of Er 3+ to PVDF is shown to improve piezoelectric properties due to the formation of a self-polarized ferroelectric β-phase and the creation of an electret-like porous structure. In addition, we demonstrate that Er 3+ acts to enhance heat transfer into the Er-PVDF film due to its excellent infrared absorbance, which, leads to rapid and large temperature fluctuations and improved pyroelectric energy transformation. We demonstrate the potential of this novel material for mechanical energy harvesting by creating a durable ferroelectret energy harvester/nanogenerator (FTNG). The high thermal stability of the β-phase enables the FTNG to harvest large temperature fluctuations (ΔT ~ 24 K). Moreover, the superior mechanosensitivity, S M  ~ 3.4 VPa -1 of the FTNG enables the design of a wearable self-powered health-care monitoring system by human-machine integration. The combination of rare-earth ion, Er 3+ with the ferroelectricity of PVDF provides a new and robust approach for delivering smart materials and structures for self-powered wireless technologies, sensors and Internet of Things (IoT) devices.

  13. Prediction of temperature and HAZ in thermal-based processes with Gaussian heat source by a hybrid GA-ANN model

    Science.gov (United States)

    Fazli Shahri, Hamid Reza; Mahdavinejad, Ramezanali

    2018-02-01

    Thermal-based processes with Gaussian heat source often produce excessive temperature which can impose thermally-affected layers in specimens. Therefore, the temperature distribution and Heat Affected Zone (HAZ) of materials are two critical factors which are influenced by different process parameters. Measurement of the HAZ thickness and temperature distribution within the processes are not only difficult but also expensive. This research aims at finding a valuable knowledge on these factors by prediction of the process through a novel combinatory model. In this study, an integrated Artificial Neural Network (ANN) and genetic algorithm (GA) was used to predict the HAZ and temperature distribution of the specimens. To end this, a series of full factorial design of experiments were conducted by applying a Gaussian heat flux on Ti-6Al-4 V at first, then the temperature of the specimen was measured by Infrared thermography. The HAZ width of each sample was investigated through measuring the microhardness. Secondly, the experimental data was used to create a GA-ANN model. The efficiency of GA in design and optimization of the architecture of ANN was investigated. The GA was used to determine the optimal number of neurons in hidden layer, learning rate and momentum coefficient of both output and hidden layers of ANN. Finally, the reliability of models was assessed according to the experimental results and statistical indicators. The results demonstrated that the combinatory model predicted the HAZ and temperature more effective than a trial-and-error ANN model.

  14. Biomimetic synthesis and characterization of semiconducting hybrid

    Indian Academy of Sciences (India)

    Triple hybrid materials based on polyaniline-polyethylene glycol and cadmium sulphide have been prepared by the duffusion–limited biomimetic route and characterized by a number of spectroscopic, XRD, SEM, thermal and electrical measurements. These hybrid materials have been prepared by controlled precipitation of ...

  15. Hybrid reactors

    International Nuclear Information System (INIS)

    Moir, R.W.

    1980-01-01

    The rationale for hybrid fusion-fission reactors is the production of fissile fuel for fission reactors. A new class of reactor, the fission-suppressed hybrid promises unusually good safety features as well as the ability to support 25 light-water reactors of the same nuclear power rating, or even more high-conversion-ratio reactors such as the heavy-water type. One 4000-MW nuclear hybrid can produce 7200 kg of 233 U per year. To obtain good economics, injector efficiency times plasma gain (eta/sub i/Q) should be greater than 2, the wall load should be greater than 1 MW.m -2 , and the hybrid should cost less than 6 times the cost of a light-water reactor. Introduction rates for the fission-suppressed hybrid are usually rapid

  16. Dimensioning of a photovoltaic-wind hybrid system in UFRJ campus of the Ilha do Fundao; Dimensionamento de um sistema hibrido eolico-fotovoltaico na UFRJ Campus Ilha do Fundao

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Silvio Carlos Anibal de [Universidade Federal do Rio de Janeiro (DEM/UFRJ), RJ (Brazil). Dept. de Engenharia Mecanica], e-mail: silvioa@gmail.com; Santos, Rodrigo Zimmer de Abreu; Argolo, Felipe Henrique Bohm; Danziger, Fernando Artur Ragoni; Sollero, Luiz Paulo Vervloet; Castro, Marcial Pereira Saboya de [Universidade Federal do Rio de Janeiro (DEM/UFRJ), RJ (Brazil). Dept. de Engenharia Industrial], e-mail: rodzimmer@gmail.com, e-mail: felipeargolo@yahoo.com.br, e-mail: ragonziger@gmail.com, e-mail: lpsollero@gmail.com, e-mail: marcial.saboya@gmail.com

    2008-07-01

    A techno-economic analysis of a grid connected photovoltaic-wind hybrid energy system is done in the present paper. The set-up consists of photovoltaic solar-cell arrays, wind generators, a lead acid storage batteries and an inverter unit to convert DC power to AC power. The study has been performed with the simulation tool HOMER (Hybrid Optimization Model for Electric Renewable) developed by the National Renewable Energy Laboratory (NREL) for techno-economical feasibility studies of hybrid systems. The system is connected to the electrical grid in order to supply all the electrical energy demand of the Technological Centre of the Federal University of Rio de Janeiro. Many systems configurations have been considered and it was possible to simulate the hourly operation of each system and to calculate technical, economic and environmental performance parameters. The best configuration is a Fuhrlander 30 wind generator, associated to a photovoltaic system to reach the generation of 96% of the energy demand by means of renewable sources. (author)

  17. Nuclear hybrid energy infrastructure

    Energy Technology Data Exchange (ETDEWEB)

    Agarwal, Vivek; Tawfik, Magdy S.

    2015-02-01

    The nuclear hybrid energy concept is becoming a reality for the US energy infrastructure where combinations of the various potential energy sources (nuclear, wind, solar, biomass, and so on) are integrated in a hybrid energy system. This paper focuses on challenges facing a hybrid system with a Small Modular Reactor at its core. The core of the paper will discuss efforts required to develop supervisory control center that collects data, supports decision-making, and serves as an information hub for supervisory control center. Such a center will also be a model for integrating future technologies and controls. In addition, advanced operations research, thermal cycle analysis, energy conversion analysis, control engineering, and human factors engineering will be part of the supervisory control center. Nuclear hybrid energy infrastructure would allow operators to optimize the cost of energy production by providing appropriate means of integrating different energy sources. The data needs to be stored, processed, analyzed, trended, and projected at right time to right operator to integrate different energy sources.

  18. Enhancement Performance of Hybrid Membrane Zeolite/PES for Produced Water Treatment With Membrane Modification Using Combination of Ulta Violet Irradiation, Composition of Zeolite and Thermal Annealing

    Directory of Open Access Journals (Sweden)

    Djoko Kusworo Tutuk

    2018-01-01

    Full Text Available Produced water is a wastewater from oil production that must be treated well. Membrane is one alternative of water treatments technology based on filtration method. However, in the use of membrane, there’s no exact optimal variable that influences membrane performance.This underlying research to assess factors that influences membrane performance to obtain optimal condition. Therefore, the objectives of this study are determining the effect of variable process in membrane fabrication and several modification techniques on membrane performance. The membranes were fabricated via dry-wet phase inversion method. The process variables of this experiment are varying the Zeolite concentration by low level 1% weight and 3% weight, UV irradiation time low level 2 minutes and high level 6 minutes, thermal annealing temperature low level 160°C and high level 180°C. The experiment runs were designed using central composite design. From the research that has been perfromed, PES/Zeolit membrane has a higher permeability after being irradiated by UV light and denser pore after heating and the longer of annealing time.

  19. Synthesis, Structural Characterization, and Thermal Properties of the Poly(methylmethacrylate/δ-FeOOH Hybrid Material: An Experimental and Theoretical Study

    Directory of Open Access Journals (Sweden)

    Silviana Corrêa

    2016-01-01

    Full Text Available The δ-FeOOH/PMMA nanocomposites with 0.5 and 2.5 wt.% of δ-FeOOH were prepared by grafting 3-(trimethoxysilylpropyl methacrylate on the surface of the iron oxyhydroxide particles. The FTIR spectra of the δ-FeOOH/PMMA nanocomposites showed that the silane monomers were covalently attached to the δ-FeOOH particles. Because of the strong interaction between the PMMA and δ-FeOOH nanoparticles, the thermal stability of the δ-FeOOH/PMMA nanocomposites was improved compared to the pure PMMA. The SEM analysis conferred the size agglomerate of particles regarding the morphology of samples. The theoretical study enabled a better understanding of the interaction of the polymer with the iron oxyhydroxide. The DFT-based calculations reinforce the radical trapping mechanism of stabilization of nanocomposites; that is, Fe3+ species might be able to accept electrons coming from the organic phase that decomposes via radical unzipping. The radical scavenge effect delays the weight loss of polymer.

  20. Hybrid composites

    CSIR Research Space (South Africa)

    Jacob John, Maya

    2009-04-01

    Full Text Available mixed short sisal/glass hybrid fibre reinforced low density polyethylene composites was investigated by Kalaprasad et al [25].Chemical surface modifications such as alkali, acetic anhydride, stearic acid, permanganate, maleic anhydride, silane...

  1. Sneutrino Hybrid Inflation

    International Nuclear Information System (INIS)

    Antusch, Stefan

    2006-01-01

    We review the scenario of sneutrino hybrid inflation, where one of the singlet sneutrinos, the superpartners of the right-handed neutrinos, plays the role of the inflaton. In a minimal model of sneutrino hybrid inflation, the spectral index is given by ns ≅ 1 + 2γ. With γ = 0.025 ± 0.01 constrained by WMAP, a running spectral index vertical bar dns/dlnk vertical bar << vertical barγvertical bar and a tensor-to-scalar ratio r << γ2 are predicted. Small neutrino masses arise from the seesaw mechanism, with heavy masses for the singlet (s)neutrinos generated by the vacuum expectation value of the waterfall field after inflation. The baryon asymmetry of the universe can be explained by non-thermal leptogenesis via sneutrino inflaton decay, with low reheat temperature TRH ≅ 106 GeV

  2. Hybrid intermediaries

    OpenAIRE

    Cetorelli, Nicola

    2014-01-01

    I introduce the concept of hybrid intermediaries: financial conglomerates that control a multiplicity of entity types active in the "assembly line" process of modern financial intermediation, a system that has become known as shadow banking. The complex bank holding companies of today are the best example of hybrid intermediaries, but I argue that financial firms from the "nonbank" space can just as easily evolve into conglomerates with similar organizational structure, thus acquiring the cap...

  3. Gas storage carbon with enhanced thermal conductivity

    Science.gov (United States)

    Burchell, Timothy D.; Rogers, Michael Ray; Judkins, Roddie R.

    2000-01-01

    A carbon fiber carbon matrix hybrid adsorbent monolith with enhanced thermal conductivity for storing and releasing gas through adsorption and desorption is disclosed. The heat of adsorption of the gas species being adsorbed is sufficiently large to cause hybrid monolith heating during adsorption and hybrid monolith cooling during desorption which significantly reduces the storage capacity of the hybrid monolith, or efficiency and economics of a gas separation process. The extent of this phenomenon depends, to a large extent, on the thermal conductivity of the adsorbent hybrid monolith. This invention is a hybrid version of a carbon fiber monolith, which offers significant enhancements to thermal conductivity and potential for improved gas separation and storage systems.

  4. Thermal management of a multiple mini-channel heat sink by the integration of a thermal responsive shape memory material

    International Nuclear Information System (INIS)

    Di Maio, E.; Mastrullo, R.; Mauro, A.W.; Toto, D.

    2014-01-01

    In this paper, a novel application of a thermo-responsive shape memory polymer (SMP) is proposed to smart-control the forced flow of water in a multi mini-channel heat sink. In particular, it is reported that millimeter-sized cylinders made of SMP could be used to smartly obstruct the fluid flow by adapting the flow cross section to the heat load to be removed. By integrating the sensing, the control and the actuation functions within a unique, millimeter-sized device, these micro-valves, unlike the traditional actuators normally used for flow control, could be easily embedded into small heat sinks, with significant space and energy saving, useful, in particular, in systems where several miniaturized components have to be cooled concurrently, such as the modern mainframes or the concentrated photovoltaic solar cells. Two possible configurations for the SMP were considered in this study: an “open” configuration, without any obstruction of the water flow free and an “obstructed” configuration, with the millimeter-sized cylinder partially occupying the mini-channel. A numerical, steady state analysis was carried out with water in single-phase forced convection, to determine the effect of these two states on the internal fluid flow characteristics under different conditions of heat flux and pressure drop and to evaluate the overall thermal behavior of the smart-controlled multiple mini-channel heat sink in terms of ability to control the temperature of the system and to reduce the energy consumption. -- Highlights: • A novel application of a SMP material is investigated for the thermal management of a heat sink. • Numerical simulations to find the matching of the heat sink and material system after regulation were carried out. • The investigated system is able to control the heat sink temperature. • Further analysis for system stability are required

  5. Sol-gel encapsulation of pullulanase in the presence of hybrid magnetic (Fe3O4-chitosan) nanoparticles improves thermal and operational stability.

    Science.gov (United States)

    Long, Jie; Li, Xingfei; Zhan, Xiaobei; Xu, Xueming; Tian, Yaoqi; Xie, Zhengjun; Jin, Zhengyu

    2017-06-01

    Pullulanase was sol-gel encapsulated in the presence of magnetic chitosan/Fe 3 O 4 nanoparticles. The resulting immobilized pullulanase was characterized by scanning electron microscopy, vibrating sample magnetometry, Fourier transform infrared spectroscopy and thermogravimetric analysis. The results showed that the addition of pullulanase created a more regular surface on the sol-gel matrix and an enhanced magnetic response to an applied magnetic field. The maximal activity retention (83.9%) and specific activity (291.7 U/mg) of the immobilized pullulanase were observed under optimized conditions including an octyltriethoxysilane:tetraethoxysilane (OTES:TEOS) ratio of 1:2 and enzyme concentration of 0.484 mg/mL sol. The immobilized enzyme exhibited good thermal stability. When the temperature was above 60 °C, the immobilized pullulanase showed significantly higher activity than the free enzyme (p sol-gel encapsulation and co-immobilized by crosslinking-encapsulation retained 52 and 69% of their initial activity after 5 h at 62 °C, respectively, compared to 11% for the free enzyme. Moreover, the stability of the pullulanase was improved by crosslinking-encapsulation, as the enzyme retained more than 85 and 81% of its original activity after 5 and 6 consecutive reuses, respectively, compared to 80 and 72% of its original activity for simple sol-gel encapsulated enzymes. This indicated the leakage of enzyme molecules through the pores of the gel was substantially abated by cross-linking. Such immobilized pullulanase provides high stability and ease of enzyme recovery, characteristics that are advantageous for applications in the food industry that involve continuous starch processing.

  6. Model of thermal conductivity of anisotropic nanodiamond

    International Nuclear Information System (INIS)

    Dudnik, S.F.; Kalinichenko, A.I.; Strel'nitskij, V.E.

    2014-01-01

    Dependence of thermal conductivity of nanocrystalline diamond on grain size and shape is theoretically investigated. Nanodiamond is considered as two-phase material composed of diamond grains characterizing by three main dimensions and segregated by thin graphite layers with electron, phonon or hybrid thermal conductivity. Influence of type of thermal conductance and thickness of boundary layer on thermal conductivity of nanodiamond is analyzed. Derived dependences of thermal conductivity on grain dimensions are compared with experimental data

  7. Photovoltaics - solar power stations. Prospects of a cutting edge technology

    International Nuclear Information System (INIS)

    Heidenreich, M.

    2002-01-01

    Photovoltaics is the sector of the future in this millennium. The process of human urbanization has led to a high demand for electricity; at the same time high-density urban settlement offers an enormous surface area that could be used for photovoltaic equipment. Such surfaces include rooftops, building facades, parking lots for automobiles, train stations and solar soundproofing walls. According to conservative estimates, Austria has sufficient surface area for a peak solar output of 4,000 MW. This would be sufficient to supply some 1.6 million households with electricity from unlimited solar energy. However, a tremendous marketing effort will be required in order to achieve generation on such a scale. (author)

  8. The German Market for photovoltaic (solar-produced electricity)

    International Nuclear Information System (INIS)

    1999-06-01

    In preparation for reducing the CO2 emission and in so living up to the Kyoto-protocol with the succeeding changes, renewable energy has - including photovoltaic - got an increasing importance in the world over - especially in Germany. If the technical potentials in Germany are utilized optimally, then 75% of the total German electricity production with photovoltaic are covered. At the moment it is only about 1 per thousand. There is a political will to promote photovoltaic in Germany, which results in high account prices and different plant supporting programmes. In the coming 6 years the official aim is that a minimum of 100.000 photovoltaic power plants are installed with an average capacitate for 3 kWp. The competition for the market is hard. There are many national and international suppliers, so the co-operations between the large German producers seem to be obvious. (EHS)

  9. Silicon nanostructures for third generation photovoltaic solar cells

    International Nuclear Information System (INIS)

    Conibeer, Gavin; Green, Martin; Corkish, Richard; Cho, Young; Cho, Eun-Chel; Jiang, Chu-Wei; Fangsuwannarak, Thipwan; Pink, Edwin; Huang, Yidan; Puzzer, Tom; Trupke, Thorsten; Richards, Bryce; Shalav, Avi; Lin, Kuo-lung

    2006-01-01

    The concept of third generation photovoltaics is to significantly increase device efficiencies whilst still using thin film processes and abundant non-toxic materials. This can be achieved by circumventing the Shockley-Queisser limit for single band gap devices, using multiple energy threshold approaches. At University of NSW, as part of our work on Third Generation devices, we are using the energy confinement of silicon based quantum dot nanostructures to engineer wide band gap materials to be used as upper cell elements in Si based tandem cells. HRTEM data shows Si nanocrystal formation in oxide and nitride matrixes with a controlled nanocrystal size, grown by layered reactive sputtering and layered PECVD. Photoluminescence evidence for quantum confinement in the Si quantum dots in oxide agrees with the calculated increase in PL energy with reduction in dot size. Resistivity measurements with temperature give tentative proof of conduction and we are investigating junction formation in these materials. We are also using similar Si quantum dot structures in double barrier resonant tunneling structures for use in hot carrier solar cell contacts. These must collect carriers over a limited energy range. Negative differential resistance has been observed in room temperature I-V on these samples, a necessary proof of concept for selective energy filter contacts

  10. Interactive Visual Analysis for Organic Photovoltaic Solar Cells

    KAUST Repository

    Abouelhassan, Amal A.

    2017-01-01

    Organic Photovoltaic (OPV) solar cells provide a promising alternative for harnessing solar energy. However, the efficient design of OPV materials that achieve better performance requires support by better-tailored visualization tools than

  11. Trend chart: photovoltaic solar energy. Forth quarter 2016

    International Nuclear Information System (INIS)

    Coltier, Yves

    2017-02-01

    This publication presents a quarterly review of power generation from photovoltaic power plants connected to the French grid (continental France, Corsica and overseas territories): total connected load, quarterly distribution of new connections, progress of connected power during the last years, power generated since the beginning of the year and comparison with previous years, projects in progress, detailed regional results, methodology used

  12. Trend chart: photovoltaic solar energy. Second quarter 2016

    International Nuclear Information System (INIS)

    Reynaud, Didier

    2016-08-01

    This newsletter presents a quarterly review of the French photovoltaic park situation: evolution of the connected power, new connected facilities, production by power range, ongoing projects and regional statistics (number of facilities, power, distribution, evolution)

  13. Trend chart: photovoltaic solar energy. Third quarter 2016

    International Nuclear Information System (INIS)

    Coltier, Yves

    2016-11-01

    This publication presents a quarterly review of power generation from photovoltaic power plants connected to the French grid (continental France, Corsica and overseas territories): total connected load, quarterly distribution of new connections, progress of connected power during the last years, power generated since the beginning of the year and comparison with previous years, projects in progress, detailed regional results, methodology used

  14. Trend chart: photovoltaic solar energy. First quarter 2016

    International Nuclear Information System (INIS)

    Reynaud, Didier

    2016-05-01

    This newsletter presents a quarterly review of the French photovoltaic park situation: evolution of the connected power, new connected facilities, production by power range, ongoing projects and regional statistics (number of facilities, power, distribution, evolution)

  15. Trend chart: photovoltaic solar energy. Forth quarter 2015

    International Nuclear Information System (INIS)

    Reynaud, Didier

    2016-02-01

    This publication presents a quarterly review of power generation from photovoltaic power plants connected to the French grid (continental France, Corsica and overseas territories): total connected load, quarterly distribution of new connections, progress of connected power during the last years, power generated since the beginning of the year and comparison with previous years, projects in progress, detailed regional results, methodology used

  16. Trend chart: photovoltaic solar energy. First quarter 2017

    International Nuclear Information System (INIS)

    2017-05-01

    This publication presents a quarterly review of power generation from photovoltaic power plants connected to the French grid (continental France, Corsica and overseas territories): total connected load, quarterly distribution of new connections, progress of connected power during the last years, power generated since the beginning of the year and comparison with previous years, projects in progress, detailed regional results, methodology used

  17. Tracking strategy for photovoltaic solar systems in high latitudes

    International Nuclear Information System (INIS)

    Quesada, Guillermo; Guillon, Laura; Rousse, Daniel R.; Mehrtash, Mostafa; Dutil, Yvan; Paradis, Pierre-Luc

    2015-01-01

    Highlights: • In cloudy conditions tracking the sun is ineffective. • A methodology to estimate a theoretical threshold for solar tracking was developed. • A tracking strategy to maximize electricity production was proposed. - Abstract: Several studies show that from about 20% to 50% more solar energy can be recovered by using photovoltaic systems that track the sun rather than systems set at a fixed angle. For overcast or cloudy days, recent studies propose the use of a set position in which each photovoltaic panel faces toward the zenith (horizontal position). Compared to a panel that follows the sun’s path, this approach claims that a horizontal panel increases the amount of solar radiation captured and subsequently the quantity of electricity produced. The present work assesses a solar tracking photovoltaic panel hourly and seasonally in high latitudes. A theoretical method based on an isotropic sky model was formulated, implemented, and used in a case study analysis of a grid-connected photovoltaic system in Montreal, Canada. The results obtained, based on the definition of a critical hourly global solar radiation, were validated numerically and experimentally. The study confirmed that a zenith-set sun tracking strategy for overcast or mostly cloudy days in summer is not advantageous

  18. Standard Terminology Relating to Photovoltaic Solar Energy Conversion

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2005-01-01

    1.1 This terminology pertains to photovoltaic (radiant-to-electrical energy conversion) device performance measurements and is not a comprehensive list of terminology for photovoltaics in general. 1.2 Additional terms used in this terminology and of interest to solar energy may be found in Terminology E 772.

  19. Photovoltaic solar energy;L'energie solaire photovoltaique

    Energy Technology Data Exchange (ETDEWEB)

    Mouratoglou, P. [EDF Energies Nouvelles, 75 - Paris (France); Therond, P.G. [EDF Dir. Nouvelles Technologies, 75 - Paris (France)

    2009-11-15

    The most important assets of photovoltaic energy for sustainable development are its simplicity (no need for complicated thermodynamical cycles) and the universal availability of the sun which explains its great popularity. The main restraint to its full development is the high cost of the technologies used. The silicon technology is the historical technology, it has high conversion rates but is expensive because of high fabrication costs. This technology represents 80% of the market. On the other hand the thin film technology with CdTe, CIS or CIGS is promising in terms of costs but requires research works to increase its conversion rate. Japan and Germany are the leader countries in terms of photovoltaic for research, industrial fabrication or state support, they are followed by Spain, Usa, and China. (A.C.)

  20. Photovoltaic. Solar electricity, a sustainable source of energy

    International Nuclear Information System (INIS)

    Stryi-Hipp, Gerhard; Loyen, Richard; Knaack, Jan; Chrometzka, Thomas

    2008-06-01

    This German publication outlines that solar energy is now essential to any sustainable energy mix, and describes the operation principle of solar photovoltaic energy production. It describes how it can be applied for the production of electricity in isolated areas, and for individual housing as well as commercial buildings, and presents the concept of ground-based solar plants. The next part discusses the development of the photovoltaic market (its huge potential, its world size) and indicates the different associated arrangements of financial support or subsidy. It also discusses how photovoltaic markets can be developed, and proposes an overview of the German model

  1. Physical aspects of ferroelectric semiconductors for photovoltaic solar energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Varo, Pilar [Departamento de Electrónica y Tecnología de Computadores, CITIC-UGR, Universidad de Granada, 18071 Granada (Spain); Bertoluzzi, Luca [Institute of Advanced Materials (INAM), Universitat Jaume I, 12006 Castelló (Spain); Bisquert, Juan, E-mail: bisquert@uji.es [Institute of Advanced Materials (INAM), Universitat Jaume I, 12006 Castelló (Spain); Department of Chemistry, Faculty of Science, King Abdulaziz University, Jeddah (Saudi Arabia); Alexe, Marin [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Coll, Mariona [Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus UAB, 08193, Bellaterra, Catalonia (Spain); Huang, Jinsong [Department of Mechanical and Materials Engineering and Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Lincoln, NE 68588-0656 (United States); Jimenez-Tejada, Juan Antonio [Departamento de Electrónica y Tecnología de Computadores, CITIC-UGR, Universidad de Granada, 18071 Granada (Spain); Kirchartz, Thomas [IEK5-Photovoltaik, Forschungszentrum Jülich, 52425 Jülich (Germany); Faculty of Engineering and CENIDE, University of Duisburg–Essen, Carl-Benz-Str. 199, 47057 Duisburg (Germany); Nechache, Riad; Rosei, Federico [INRS—Center Énergie, Matériaux et Télécommunications, Boulevard Lionel-Boulet, Varennes, Québec, J3X 1S2 (Canada); Yuan, Yongbo [Department of Mechanical and Materials Engineering and Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Lincoln, NE 68588-0656 (United States)

    2016-10-07

    Solar energy conversion using semiconductors to fabricate photovoltaic devices relies on efficient light absorption, charge separation of electron–hole pair carriers or excitons, and fast transport and charge extraction to counter recombination processes. Ferroelectric materials are able to host a permanent electrical polarization which provides control over electrical field distribution in bulk and interfacial regions. In this review, we provide a critical overview of the physical principles and mechanisms of solar energy conversion using ferroelectric semiconductors and contact layers, as well as the main achievements reported so far. In a ferroelectric semiconductor film with ideal contacts, the polarization charge would be totally screened by the metal layers and no charge collection field would exist. However, real materials show a depolarization field, smooth termination of polarization, and interfacial energy barriers that do provide the control of interface and bulk electric field by switchable spontaneous polarization. We explore different phenomena as the polarization-modulated Schottky-like barriers at metal/ferroelectric interfaces, depolarization fields, vacancy migration, and the switchable rectifying behavior of ferroelectric thin films. Using a basic physical model of a solar cell, our analysis provides a general picture of the influence of ferroelectric effects on the actual power conversion efficiency of the solar cell device, and we are able to assess whether these effects or their combinations are beneficial or counterproductive. We describe in detail the bulk photovoltaic effect and the contact layers that modify the built-in field and the charge injection and separation in bulk heterojunction organic cells as well as in photocatalytic and water splitting devices. We also review the dominant families of ferroelectric materials that have been most extensively investigated and have provided the best photovoltaic performance.

  2. Current challenges in organic photovoltaic solar energy conversion.

    Science.gov (United States)

    Schlenker, Cody W; Thompson, Mark E

    2012-01-01

    Over the last 10 years, significant interest in utilizing conjugated organic molecules for solid-state solar to electric conversion has produced rapid improvement in device efficiencies. Organic photovoltaic (OPV) devices are attractive for their compatibility with low-cost processing techniques and thin-film applicability to flexible and conformal applications. However, many of the processes that lead to power losses in these systems still remain poorly understood, posing a significant challenge for the future efficiency improvements required to make these devices an attractive solar technology. While semiconductor band models have been employed to describe OPV operation, a more appropriate molecular picture of the pertinent processes is beginning to emerge. This chapter presents mechanisms of OPV device operation, based on the bound molecular nature of the involved transient species. With the intention to underscore the importance of considering both thermodynamic and kinetic factors, recent progress in elucidating molecular characteristics that dictate photovoltage losses in heterojunction organic photovoltaics is also discussed.

  3. Semiconductor Grade, Solar Silicon Purification Project. [photovoltaic solar energy conversion

    Science.gov (United States)

    Ingle, W. M.; Rosler, R. S.; Thompson, S. W.; Chaney, R. E.

    1979-01-01

    A low cost by-product, SiF4, is reacted with mg silicon to form SiF2 gas which is polymerized. The (SiF2)x polymer is heated forming volatile SixFy homologues which disproportionate on a silicon particle bed forming silicon and SiF4. The silicon analysis procedure relied heavily on mass spectroscopic and emission spectroscopic analysis. These analyses demonstrated that major purification had occured and some samples were indistinguishable from semiconductor grade silicon (except possibly for phosphorus). However, electrical analysis via crystal growth reveal that the product contains compensated phosphorus and boron.

  4. Modular assembly of a photovoltaic solar energy receiver

    Science.gov (United States)

    Graven, Robert M.; Gorski, Anthony J.; Schertz, William W.; Graae, Johan E. A.

    1978-01-01

    There is provided a modular assembly of a solar energy concentrator having a photovoltaic energy receiver with passive cooling. Solar cell means are fixedly coupled to a radiant energy concentrator. Tension means bias a large area heat sink against the cell thereby allowing the cell to expand or contract with respect to the heat sink due to differential heat expansion.

  5. Physical aspects of ferroelectric semiconductors for photovoltaic solar energy conversion

    International Nuclear Information System (INIS)

    Lopez-Varo, Pilar; Bertoluzzi, Luca; Bisquert, Juan; Alexe, Marin; Coll, Mariona; Huang, Jinsong; Jimenez-Tejada, Juan Antonio; Kirchartz, Thomas; Nechache, Riad; Rosei, Federico; Yuan, Yongbo

    2016-01-01

    Solar energy conversion using semiconductors to fabricate photovoltaic devices relies on efficient light absorption, charge separation of electron–hole pair carriers or excitons, and fast transport and charge extraction to counter recombination processes. Ferroelectric materials are able to host a permanent electrical polarization which provides control over electrical field distribution in bulk and interfacial regions. In this review, we provide a critical overview of the physical principles and mechanisms of solar energy conversion using ferroelectric semiconductors and contact layers, as well as the main achievements reported so far. In a ferroelectric semiconductor film with ideal contacts, the polarization charge would be totally screened by the metal layers and no charge collection field would exist. However, real materials show a depolarization field, smooth termination of polarization, and interfacial energy barriers that do provide the control of interface and bulk electric field by switchable spontaneous polarization. We explore different phenomena as the polarization-modulated Schottky-like barriers at metal/ferroelectric interfaces, depolarization fields, vacancy migration, and the switchable rectifying behavior of ferroelectric thin films. Using a basic physical model of a solar cell, our analysis provides a general picture of the influence of ferroelectric effects on the actual power conversion efficiency of the solar cell device, and we are able to assess whether these effects or their combinations are beneficial or counterproductive. We describe in detail the bulk photovoltaic effect and the contact layers that modify the built-in field and the charge injection and separation in bulk heterojunction organic cells as well as in photocatalytic and water splitting devices. We also review the dominant families of ferroelectric materials that have been most extensively investigated and have provided the best photovoltaic performance.

  6. EU Directives, national regulations and incentives for photovoltaic solar energy

    International Nuclear Information System (INIS)

    Jager-Waldau, A.; Ossenbrink, H.; Scholz, H.; Bloem, H.; Werring, L.

    2004-01-01

    The European Union long-term strategy for security of energy supply and its commitment to curb climate change led to the adoption of a series of Strategy Papers and EU Directives. In all these, it is clearly stated that climate change is a long-term challenge for the international community and that the commitments made in the Kyoto Protocol can only be a first step. The promotion of renewable energies is a most important element of this process. It regards industry, jobs and foreign trade balance as well, generating benefit to social sustainability. Photovoltaic is a key technology with the potential not only to serve the needs in energy supply of tomorrow in a sustainable way, but already today, it can improve security and stability of electricity services at peak times, due to its decentralized nature. This paper gives an update on the EU and National legislation in place to promote the implementation of photovoltaic. (authors)

  7. a new analytical modeling method for photovoltaic solar cells based

    African Journals Online (AJOL)

    Zieba Falama R, Dadjé A, Djongyang N and Doka S.Y

    CELLS BASED ON DERIVATIVE POWER FUNCTION ... Received: 25 Jaunary 2016 / Accepted: 25 April 2016 / Published online: 01 May 2016 ..... For the simulation, two electric PV modules for different technologies were used; these.

  8. Wireless transmission of metering data from a photovoltaic solar ...

    African Journals Online (AJOL)

    The data from direct cable connection was highly reliable because data ... aggregated solar home systems instead of establishing grid connected solar farms. ... Key words: PV solar home system, DC power meter, GSM, data adaptor software ...

  9. Tandem photovoltaic solar cells and increased solar energy conversion efficiency

    Science.gov (United States)

    Loferski, J. J.

    1976-01-01

    Tandem photovoltaic cells, as proposed by Jackson (1955) to increase the efficiency of solar energy conversion, involve the construction of a system of stacked p/n homojunction photovoltaic cells composed of different semiconductors. It had been pointed out by critics, however, that the total power which could be extracted from the cells in the stack placed side by side was substantially greater than the power obtained from the stacked cells. A reexamination of the tandem cell concept in view of the development of the past few years is conducted. It is concluded that the use of tandem cell systems in flat plate collectors, as originally envisioned by Jackson, may yet become feasible as a result of the development of economically acceptable solar cells for large scale terrestrial power generation.

  10. Interactive Visual Analysis for Organic Photovoltaic Solar Cells

    KAUST Repository

    Abouelhassan, Amal A.

    2017-12-05

    Organic Photovoltaic (OPV) solar cells provide a promising alternative for harnessing solar energy. However, the efficient design of OPV materials that achieve better performance requires support by better-tailored visualization tools than are currently available, which is the goal of this thesis. One promising approach in the OPV field is to control the effective material of the OPV device, which is known as the Bulk-Heterojunction (BHJ) morphology. The BHJ morphology has a complex composition. Current BHJ exploration techniques deal with the morphologies as black boxes with no perception of the photoelectric current in the BHJ morphology. Therefore, this method depends on a trial-and-error approach and does not efficiently characterize complex BHJ morphologies. On the other hand, current state-of-the-art methods for assessing the performance of BHJ morphologies are based on the global quantification of morphological features. Accordingly, scientists in OPV research are still lacking a sufficient understanding of the best material design. To remove these limitations, we propose a new approach for knowledge-assisted visual exploration and analysis in the OPV domain. We develop new techniques for enabling efficient OPV charge transport path analysis. We employ, adapt, and develop techniques from scientific visualization, geometric modeling, clustering, and visual interaction to obtain new designs of visualization tools that are specifically tailored for the needs of OPV scientists. At the molecular scale, the user can use semantic rules to define clusters of atoms with certain geometric properties. At the nanoscale, we propose a novel framework for visual characterization and exploration of local structure-performance correlations. We also propose a new approach for correlating structural features to performance bottlenecks. We employ a visual feedback strategy that allows scientists to make intuitive choices about fabrication parameters. We furthermore propose a visual analysis framework to help answer domain science questions through parameter space exploration for local morphology features. This framework is built on the shape-based clustering of local regions (patches), which for the first time enables local analysis of BHJ morphologies. Using our proposed system, domain experts can interactively create and visualize new BHJ structures of interest at both the molecular and nanoscale levels in a relatively short time.

  11. Photovoltaic solar panels of crystalline silicon: Characterization and separation.

    Science.gov (United States)

    Dias, Pablo Ribeiro; Benevit, Mariana Gonçalves; Veit, Hugo Marcelo

    2016-03-01

    Photovoltaic panels have a limited lifespan and estimates show large amounts of solar modules will be discarded as electronic waste in a near future. In order to retrieve important raw materials, reduce production costs and environmental impacts, recycling such devices is important. Initially, this article investigates which silicon photovoltaic module's components are recyclable through their characterization using X-ray fluorescence, X-ray diffraction, energy dispersion spectroscopy and atomic absorption spectroscopy. Next, different separation methods are tested to favour further recycling processes. The glass was identified as soda-lime glass, the metallic filaments were identified as tin-lead coated copper, the panel cells were made of silicon and had silver filaments attached to it and the modules' frames were identified as aluminium, all of which are recyclable. Moreover, three different components segregation methods have been studied. Mechanical milling followed by sieving was able to separate silver from copper while chemical separation using sulphuric acid was able to detach the semiconductor material. A thermo gravimetric analysis was performed to evaluate the use of a pyrolysis step prior to the component's removal. The analysis showed all polymeric fractions present degrade at 500 °C. © The Author(s) 2016.

  12. 新型PV/T太阳能利用复合系统的实验研究%Experimental Study on A Novel Hybrid Photovoltaic/Thermal Solar System

    Institute of Scientific and Technical Information of China (English)

    李光明; 刘祖明; 李景天; 廖华; 朱勋梦; 张卫东

    2013-01-01

    A novel hybrid photovoltaic /thermal solar system,which combining flat stainless steel box as solar heat collectors with aluminum alloy backplane monocrystalline silicon PV components,and using the thermally conductive silica-gel for adhesion,was designed to improve the energy efficiency and to supply hot water and electricity.The system performed good adhesion,insulation and heat conduction between the collector and PV module.The electrical and thermal efficiency of the system are tested through experiments conducted in Kunming area with different water mass and under different conditions.The results show that the total efficiency and general energy efficiency of novel PV/T system is higher in 75kg water mass sunny weather.Its electrical efficiency,thermal efficiency,total efficiency and general energy efficiency are 14%,37%,51%,and 70.72%,respectively.Compared with in 50kg water mass sunny or 75kg water mass cloudy weather,the general efficiency has been enhanced by 11.86% or 2.09%.Compared with pure PV system or the nature circulation of the solar water collector,The novel PV/T systems has several advantages,including smaller occupied area,higher utilization of solar energy and lower expenditure.%为提高PV/T系统太阳能利用率,同时获得可利用的热水和电力,将铝合金背板型单晶硅光伏组件和自行设计制作的不锈钢扁盒式集热板相结合,用导热硅胶加以粘接制成新型光伏光热一体化(PV/T)复合系统,该系统实现了光伏组件与集热板之间良好的粘接性、绝缘性和热传导,并在昆明地区对系统进行测试,分析了系统在不同水箱水容量及不同天气工况下运行的光电光热性能.结果表明,系统在75kg水箱水容量(m)晴天工况下运行效率更高,系统的平均电效率、热效率、综合效率及综合性能效率分别在14%、37%、51%、70.72%左右,与系统在50kg水箱水容量晴天或75kg水箱水容量多云工况下运行相比,

  13. Crystal structures, Hirshfeld surface analysis, thermal behavior and dielectric properties of a new organic-inorganic hybrid [C6H10(NH3)2]Cu2Cl8

    Science.gov (United States)

    Salah, Najet; Hamdi, Besma; Bouzidia, Nabaa; Salah, Abdelhamid Ben

    2017-12-01

    A novel organic-inorganic hybrid sample [C6H10(NH3)2]Cu2Cl8 has been prepared under mild hydrothermal conditions and characterized by single crystal X-ray diffraction, Hirshfeld surface analysis, FT-IR,NMR and UV-Vis spectroscopies, differential scanning calorimetric and dielectric measurement. It is crystallized in the monoclinic system with P21/c space group. The cohesion and stabilization of the structure are provided by the hydrogen bond interactions, (Nsbnd H⋯Cl and Csbnd H⋯Cl), between [C6H10(NH3)2]2+ cation and [Cu2Cl8]2- anion. The Hirschfeld surface analysis has been performed to explore the behavior of these weak interactions. The presence of different functional groups and the nature of their vibrations were identified by FT-IR and Solid state NMR. The thermal study revealed that this compound undergoes two structural phase transitions around 353 and 376 K. Electrical measurements of our compounds have been investigated using complex impedance spectroscopy (CIS) in the frequency and temperature range 331-399 K and 200 Hz-5 MHz, respectively. The AC conductivity is explained using the correlated barrier hopping model (CBH) conduction mechanism. The nature of DC conductivity variation suggests Arrhenius type of electrical conductivity. A relationship between crystal structure and ionic conductivity was established and discussed. Finally, the real and imaginary parts of the permittivity constant are analyzed with the Cole-Cole formalism and the optical spectra indicate that the compound has a direct band gap (3.14 eV) due to direct transition. The wide band gap is due to low defect concentration in the grown crystal, which is more useful for the laser/optical applications.

  14. Hybrid stars

    Indian Academy of Sciences (India)

    Hybrid stars. AsHOK GOYAL. Department of Physics and Astrophysics, University of Delhi, Delhi 110 007, India. Abstract. Recently there have been important developments in the determination of neutron ... number and the electric charge. ... available to the system to rearrange concentration of charges for a given fraction of.

  15. Hybrid density functional theory study of Cu(In1−xGaxSe2 band structure for solar cell application

    Directory of Open Access Journals (Sweden)

    Xu-Dong Chen

    2014-08-01

    Full Text Available Cu(In1−xGaxSe2 (CIGS alloy based thin film photovoltaic solar cells have attracted more and more attention due to its large optical absorption coefficient, long term stability, low cost and high efficiency. However, the previous theoretical investigation of this material with first principle calculation cannot fulfill the requirement of experimental development, especially the accurate description of band structure and density of states. In this work, we use first principle calculation based on hybrid density functional theory to investigate the feature of CIGS, with B3LYP applied in the CuIn1−xGaxSe2 stimulation of the band structure and density of states. We report the simulation of the lattice parameter, band gap and chemical composition. The band gaps of CuGaSe2, CuIn0.25Ga0.75Se2, CuIn0.5Ga0.5Se2, CuIn0.75Ga0.25Se2 and CuInSe2 are obtained as 1.568 eV, 1.445 eV, 1.416 eV, 1.275 eV and 1.205 eV according to our calculation, which agree well with the available experimental values. The band structure of CIGS is also in accordance with the current theory.

  16. Improving long-term operation of power sources in off-grid hybrid systems based on renewable energy, hydrogen and battery

    Science.gov (United States)

    García, Pablo; Torreglosa, Juan P.; Fernández, Luis M.; Jurado, Francisco

    2014-11-01

    This paper presents two novel hourly energy supervisory controls (ESC) for improving long-term operation of off-grid hybrid systems (HS) integrating renewable energy sources (wind turbine and photovoltaic solar panels), hydrogen system (fuel cell, hydrogen tank and electrolyzer) and battery. The first ESC tries to improve the power supplied by the HS and the power stored in the battery and/or in the hydrogen tank, whereas the second one tries to minimize the number of needed elements (batteries, fuel cells and electrolyzers) throughout the expected life of the HS (25 years). Moreover, in both ESC, the battery state-of-charge (SOC) and the hydrogen tank level are controlled and maintained between optimum operating margins. Finally, a comparative study between the controls is carried out by models of the commercially available components used in the HS under study in this work. These ESC are also compared with a third ESC, already published by the authors, and based on reducing the utilization costs of the energy storage devices. The comparative study proves the right performance of the ESC and their differences.

  17. Overview of PV Wind hybrid system activities in Germany

    Energy Technology Data Exchange (ETDEWEB)

    Bopp, G.; Gabler, H.; Kiefer, K.; Preiser, K.; Wiemken, E. [Fraunhofer Institute for Solar Energy Systems ISE, Freiburg (Germany)

    1997-12-31

    Photovoltaic solar generators combined with diesel engines, in some cases additionally with wind energy converters, and battery energy storage are powering isolated mountain lodges, information centers in nature parks, isolated farms or dwellings all over Europe. A total of 300,000 buildings in Europe are estimated to be not connected to the public grid. This represents a major market potential for photovoltaic, as often photovoltaic power generation is less expensive than a connection to the electric utility. The Fraunhofer Institute for Solar Energy Systems ISE has planned, realized and monitored about 30 hybrid remote energy supply systems with PV generators typically around 5 kW for loads typically around 20 kWh per day. More than one hundred years of operational experience accumulated so far, are a sound foundation on which to draw an interim balance over problems solved and technical questions still under development. Room for further technical development is seen in the domain of system reliability and the reduction of operating costs as well as in the optimization of the utilization of the electric energy produced by the PV generator. [Espanol] Para la electrificacion en toda Europa de casas de campo en la montana, centros de informacion, parques naturales, granjas aisladas o conjuntos habitacionales, se estan usando generadores fotovoltaicos combinados con maquinas diesel, en algunos casos adicionalmente con convertidores de energia del viento y baterias para el almacenamiento de energia. Se estima que en Europa un total de 300,000 edificios no estan conectados a la red publica. Esto representa un gran mercado potencial para los sistemas fotovoltaicos, ya que a menudo la generacion fotovoltaica es menos costosa que una conexion a la empresa electrica. El Instituto Fraunhofer para Sistemas de Energia Solar ISE ha planeado, llevado a cabo y monitoreado alrededor de 30 sistemas hibridos remotos de suministro de energia con generadores fotovoltaicos

  18. Overview of PV Wind hybrid system activities in Germany

    Energy Technology Data Exchange (ETDEWEB)

    Bopp, G; Gabler, H; Kiefer, K; Preiser, K; Wiemken, E [Fraunhofer Institute for Solar Energy Systems ISE, Freiburg (Germany)

    1998-12-31

    Photovoltaic solar generators combined with diesel engines, in some cases additionally with wind energy converters, and battery energy storage are powering isolated mountain lodges, information centers in nature parks, isolated farms or dwellings all over Europe. A total of 300,000 buildings in Europe are estimated to be not connected to the public grid. This represents a major market potential for photovoltaic, as often photovoltaic power generation is less expensive than a connection to the electric utility. The Fraunhofer Institute for Solar Energy Systems ISE has planned, realized and monitored about 30 hybrid remote energy supply systems with PV generators typically around 5 kW for loads typically around 20 kWh per day. More than one hundred years of operational experience accumulated so far, are a sound foundation on which to draw an interim balance over problems solved and technical questions still under development. Room for further technical development is seen in the domain of system reliability and the reduction of operating costs as well as in the optimization of the utilization of the electric energy produced by the PV generator. [Espanol] Para la electrificacion en toda Europa de casas de campo en la montana, centros de informacion, parques naturales, granjas aisladas o conjuntos habitacionales, se estan usando generadores fotovoltaicos combinados con maquinas diesel, en algunos casos adicionalmente con convertidores de energia del viento y baterias para el almacenamiento de energia. Se estima que en Europa un total de 300,000 edificios no estan conectados a la red publica. Esto representa un gran mercado potencial para los sistemas fotovoltaicos, ya que a menudo la generacion fotovoltaica es menos costosa que una conexion a la empresa electrica. El Instituto Fraunhofer para Sistemas de Energia Solar ISE ha planeado, llevado a cabo y monitoreado alrededor de 30 sistemas hibridos remotos de suministro de energia con generadores fotovoltaicos

  19. Ultrafast Thermal Cycling of Solar Panels

    National Research Council Canada - National Science Library

    Wall, T

    1998-01-01

    Two new cyclers that utilize a novel hybrid approach to perform fast thermal cycling of solar panels have been built and are now operational in the Mechanics and Materials Technology Center at The Aerospace Corporation...

  20. Multifunctional hybrids for electromagnetic absorption

    International Nuclear Information System (INIS)

    Huynen, I.; Quievy, N.; Bailly, C.; Bollen, P.; Detrembleur, C.; Eggermont, S.; Molenberg, I.; Thomassin, J.M.; Urbanczyk, L.

    2011-01-01

    Highlights: → EM absorption requires low dielectric constant and ∼1 S/m electrical conductivity. → New hybrids were processed with CNT-filled polymer foam inserted in Al honeycomb. → The EM absorption in the GHz range is superior to any known material. → A closed form model is used to guide the design of the hybrid. → The architectured material is light with potential for thermal management. - Abstract: Electromagnetic (EM) interferences are ubiquitous in modern technologies and impact on the reliability of electronic devices and on living cells. Shielding by EM absorption, which is preferable over reflection in certain instances, requires combining a low dielectric constant with high electrical conductivity, which are antagonist properties in the world of materials. A novel class of hybrid materials for EM absorption in the gigahertz range has been developed based on a hierarchical architecture involving a metallic honeycomb filled with a carbon nanotube-reinforced polymer foam. The waveguide characteristics of the honeycomb combined with the performance of the foam lead to unexpectedly large EM power absorption over a wide frequency range, superior to any known material. The peak absorption frequency can be tuned by varying the shape of the honeycomb unit cell. A closed form model of the EM reflection and absorption provides a tool for the optimization of the hybrid. This designed material sets the stage for a new class of sandwich panels combining high EM absorption with mass efficiency, stiffness and thermal management.

  1. Hybrid Ceramic Matrix Fibrous Composites: an Overview

    Science.gov (United States)

    Naslain, R.

    2011-10-01

    Ceramic-Matrix Composites (CMCs) consist of a ceramic fiber architecture in a ceramic matrix, bonded together through a thin interphase. The present contribution is limited to non-oxide CMCs. Their constituents being oxidation-prone, they are protected by external coatings. We state here that CMCs display a hybrid feature, when at least one of their components is not homogeneous from a chemical or microstructural standpoint. Hybrid fiber architectures are used to tailor the mechanical or thermal CMC-properties whereas hybrid interphases, matrices and coatings to improve CMC resistance to aggressive environments.

  2. Hybrid Ceramic Matrix Fibrous Composites: an Overview

    International Nuclear Information System (INIS)

    Naslain, R

    2011-01-01

    Ceramic-Matrix Composites (CMCs) consist of a ceramic fiber architecture in a ceramic matrix, bonded together through a thin interphase. The present contribution is limited to non-oxide CMCs. Their constituents being oxidation-prone, they are protected by external coatings. We state here that CMCs display a hybrid feature, when at least one of their components is not homogeneous from a chemical or microstructural standpoint. Hybrid fiber architectures are used to tailor the mechanical or thermal CMC-properties whereas hybrid interphases, matrices and coatings to improve CMC resistance to aggressive environments.

  3. On the isolation of elemental carbon (EC) for micro-molar 14C accelerator mass spectrometry: development of a hybrid reference material for 14C-EC accuracy assurance, and a critical evaluation of the thermal optical kinetic (TOK) EC isolation procedure

    Science.gov (United States)

    Currie, L. A.; Kessler, J. D.

    2005-10-01

    The primary objective of the research reported here has been the development of a hybrid reference material (RM) to serve as a test of accuracy for elemental carbon (EC) isotopic (14C) speciation measurements. Such measurements are vital for the quantitative apportionment of fossil and biomass sources of "soot" (EC), the tracer of fire that has profound effects on health, atmospheric visibility, and climate. Previous studies of 14C-EC measurement quality, carried out with NIST SRM 1649a (Urban Dust), showed a range of results, but since the "truth" was not known for this natural matrix RM, one had to rely on isotopic-chemical consistency evidence (14C in PAH, EC) of measurement validity (Currie et al., 2002). Components of the new Hybrid RM (DiesApple), however, have known 14C and EC composition, and they are nearly orthogonal (isotopically and chemically). NIST SRM 2975 (Forklift Diesel Soot) has little or no 14C, and its major compositional component is EC; SRM 1515 (Apple Leaves) has the 14C content of biomass-C, and it has little or no EC. Thus, the Hybrid RM can serve as an absolute isotopic test for the absence of EC-mimicking pyrolysis-C (char) from SRM 1515 in the EC isolate of the Hybrid RM, as well as a test for conservation of its dominant soot fraction throughout the isolation procedure. The secondary objective was to employ the Hybrid RM for the comparative evaluation of the thermal optical kinetic (TOK) and thermal optical transmission (TOT) methods for the isolation of EC for micro-molar carbon accelerator mass spectrometry (AMS). As part of this process, the relatively new TOK method was subjected to a critical evaluation and significant development. Key findings of our study are: (1) both methods exhibited biomass-C "leakage"; for TOT, the EC fraction isolated for AMS contained about 8% of the original biomass-C; for TOK, the refractory carbon (RC) isolated contained about 3% of the original biomass-C.; (2) the initial isothermal oxidation stage of

  4. On the isolation of elemental carbon (EC for micro-molar 14C accelerator mass spectrometry: development of a hybrid reference material for 14C-EC accuracy assurance, and a critical evaluation of the thermal optical kinetic (TOK EC isolation procedure

    Directory of Open Access Journals (Sweden)

    L. A. Currie

    2005-01-01

    Full Text Available The primary objective of the research reported here has been the development of a hybrid reference material (RM to serve as a test of accuracy for elemental carbon (EC isotopic (14C speciation measurements. Such measurements are vital for the quantitative apportionment of fossil and biomass sources of 'soot' (EC, the tracer of fire that has profound effects on health, atmospheric visibility, and climate. Previous studies of 14C-EC measurement quality, carried out with NIST SRM 1649a (Urban Dust, showed a range of results, but since the 'truth' was not known for this natural matrix RM, one had to rely on isotopic-chemical consistency evidence (14C in PAH, EC of measurement validity (Currie et al., 2002. Components of the new Hybrid RM (DiesApple, however, have known 14C and EC composition, and they are nearly orthogonal (isotopically and chemically. NIST SRM 2975 (Forklift Diesel Soot has little or no 14C, and its major compositional component is EC; SRM 1515 (Apple Leaves has the 14C content of biomass-C, and it has little or no EC. Thus, the Hybrid RM can serve as an absolute isotopic test for the absence of EC-mimicking pyrolysis-C (char from SRM 1515 in the EC isolate of the Hybrid RM, as well as a test for conservation of its dominant soot fraction throughout the isolation procedure. The secondary objective was to employ the Hybrid RM for the comparative evaluation of the thermal optical kinetic (TOK and thermal optical transmission (TOT methods for the isolation of EC for micro-molar carbon accelerator mass spectrometry (AMS. As part of this process, the relatively new TOK method was subjected to a critical evaluation and significant development. Key findings of our study are: (1 both methods exhibited biomass-C 'leakage'; for TOT, the EC fraction isolated for AMS contained about 8% of the original biomass-C; for TOK, the refractory carbon (RC isolated contained about 3% of the original biomass-C.; (2 the initial isothermal oxidation stage

  5. Sustainability assessment of a hybrid energy system

    International Nuclear Information System (INIS)

    Afgan, Nain H.; Carvalho, Maria G.

    2008-01-01

    A hybrid energy system in the form of the Object structure is the pattern for the structure of options in the evaluation of a hybrid system. The Object structure is defined as: Hybrid Energy System {[production (solar, wind, biomass, natural gas)] [utilization(electricity, heat, hydrogen)]}. In the evaluation of hybrid energy systems only several options are selected to demonstrate the sustainability assessment method application in the promotion of the specific quality of the hybrid energy system. In this analysis the following options are taken into a consideration: 1.Solar photo-voltaic power plant (PV PP), wind turbine power plant (WTPP) biomass thermal power plant (ThSTPP) for electricity, heat and hydrogen production. 2.Solar PV PP and wind power plant (WPP) for electricity and hydrogen production. 3.Biomass thermal steam turbine power plant (BThSTPP) and WPP for heat and hydrogen production. 4.Combined cycle gas turbine power plant for electricity and hydrogen production. 5.Cogeneration of electricity and water by the hybrid system. The sustainability assessment method is used for the evaluation of quality of the selected hybrid systems. In this evaluation the following indicators are used: economic indicator, environment indicator and social indicator

  6. Hybrid Qualifications

    DEFF Research Database (Denmark)

    Against the background of increasing qualification needs there is a growing awareness of the challenge to widen participation in processes of skill formation and competence development. At the same time, the issue of permeability between vocational education and training (VET) and general education...... has turned out as a major focus of European education and training policies and certainly is a crucial principle underlying the European Qualifications Framework (EQF). In this context, «hybrid qualifications» (HQ) may be seen as an interesting approach to tackle these challenges as they serve «two...

  7. Hybrid Gear

    Science.gov (United States)

    Handschuh, Robert F. (Inventor); Roberts, Gary D. (Inventor)

    2016-01-01

    A hybrid gear consisting of metallic outer rim with gear teeth and metallic hub in combination with a composite lay up between the shaft interface (hub) and gear tooth rim is described. The composite lay-up lightens the gear member while having similar torque carrying capability and it attenuates the impact loading driven noise/vibration that is typical in gear systems. The gear has the same operational capability with respect to shaft speed, torque, and temperature as an all-metallic gear as used in aerospace gear design.

  8. Intuitionistic hybrid logic

    DEFF Research Database (Denmark)

    Braüner, Torben

    2011-01-01

    Intuitionistic hybrid logic is hybrid modal logic over an intuitionistic logic basis instead of a classical logical basis. In this short paper we introduce intuitionistic hybrid logic and we give a survey of work in the area.......Intuitionistic hybrid logic is hybrid modal logic over an intuitionistic logic basis instead of a classical logical basis. In this short paper we introduce intuitionistic hybrid logic and we give a survey of work in the area....

  9. Hybrid coils having an improved heat transfer capability

    NARCIS (Netherlands)

    2008-01-01

    A hybrid coil ( 11 ) employs a wire layer ( 22 ), a wire layer ( 23 ) adjacent the wire layer ( 22 ), and a wire layer ( 24 ) adjacent the wire layer ( 23 ). The hybrid coil ( 11 ) further employs a thermal conductive insulator ( 42 ) physically disposed within a space between the wire layer ( 22 )

  10. Thermal Depth Profiling Reconstruction by Multilayer Thermal Quadrupole Modeling and Particle Swarm Optimization

    International Nuclear Information System (INIS)

    Zhao-Jiang, Chen; Shu-Yi, Zhang

    2010-01-01

    A new hybrid inversion method for depth profiling reconstruction of thermal conductivities of inhomogeneous solids is proposed based on multilayer quadrupole formalism of thermal waves, particle swarm optimization and sequential quadratic programming. The reconstruction simulations for several thermal conductivity profiles are performed to evaluate the applicability of the method. The numerical simulations demonstrate that the precision and insensitivity to noise of the inversion method are very satisfactory. (condensed matter: structure, mechanical and thermal properties)

  11. Experimental Performance Investigation of Photovoltaic/Thermal (PV–T System

    Directory of Open Access Journals (Sweden)

    Bakir C.

    2013-04-01

    Full Text Available Photovoltaic solar cells convert light energy from the sun into electricity. Photovoltaic cells are produced by semi-conducting materials to convert the energy into electricity and during this process heat is absorbed by the solar radiation. This heat causes a loss of electricity generation efficiencies.In this study, an experimental setup was designed and established to test two separate photovoltaic panel systems with alone PV and with water cooling system PV/T to examine the heat effect on PV systems. The absorbed heat energy behind the photovoltaic cell's surface in insulated ambient was removed by means of a water cooling system and the tests for both systems were simultaneously performed along the July 2011. It is found that without active water cooling, the temperature of the PV module was higher during day time and solar cells could only achieve around 8% conversion efficiency. On the other hand, when the PV module was operated with active water cooling condition, the temperature dropped significantly, leading to an increase in the efficiency of solarcells as much as 13.6%. Gained from absorbed solar heat and maximum thermal conversion efficiencies of the system are determined as 49% and 51% for two different mass flow rates. It is observed that water flow rate is effective on the increasing the conversion efficiency as well as absorption and transitionrates of cover glass in PV/T (PV–Thermal collector, the insulation material and cell efficiency. As a conclusion, the conversion efficiency of the PV system with water cooling might be improved on average about 10%. Therefore, it is recommended that PV system should be designed with most efficient type cooling system to enhance the efficiency and to decrease the payback period.

  12. Principle, function, experiences, hybrid chilled ceilings; Prinzip, Funktion, Erfahrungen. Hybrid-Kuehldecken

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, Uwe W. [Hochschule Luzern (Switzerland). Technik und Architektur

    2010-12-15

    Hybrid chilled ceilings combine a radiation chilled ceiling with thermal activations of a concrete ceiling. The activation permits the utilization of alternative and/or small cold generators for the efficient night cooling. The traditional chilled ceiling grants a speedy reaction to load variations as well as a reduction of the reverberation periods. In addition, the combination supplies a draught-free insertion of air. Beside established solutions, MWH Barcol-Air (Staefa, Switzerland) also offers project-specific hybrid chilled ceilings.

  13. Hybridized Tetraquarks

    CERN Document Server

    Esposito, A.; Polosa, A.D.

    2016-01-01

    We propose a new interpretation of the neutral and charged X, Z exotic hadron resonances. Hybridized-tetraquarks are neither purely compact tetraquark states nor bound or loosely bound molecules. The latter would require a negative or zero binding energy whose counterpart in h-tetraquarks is a positive quantity. The formation mechanism of this new class of hadrons is inspired by that of Feshbach metastable states in atomic physics. The recent claim of an exotic resonance in the Bs pi+- channel by the D0 collaboration and the negative result presented subsequently by the LHCb collaboration are understood in this scheme, together with a considerable portion of available data on X, Z particles. Considerations on a state with the same quantum numbers as the X(5568) are also made.

  14. Thermal Management and Thermal Protection Systems

    Science.gov (United States)

    Hasnain, Aqib

    2016-01-01

    During my internship in the Thermal Design Branch (ES3), I contributed to two main projects: i) novel passive thermal management system for future human exploration, ii) AVCOAT undercut thermal analysis. i) As NASA prepares to further expand human and robotic presence in space, it is well known that spacecraft architectures will be challenged with unprecedented thermal environments. Future exploration activities will have the need of thermal management systems that can provide higher reliability, mass and power reduction and increased performance. In an effort to start addressing the current technical gaps the NASA Johnson Space Center Passive Thermal Discipline has engaged in technology development activities. One of these activities was done through an in-house Passive Thermal Management System (PTMS) design for a lunar lander. The proposed PTMS, functional in both microgravity and gravity environments, consists of three main components: a heat spreader, a novel hybrid wick Variable Conductance Heat Pipe (VCHP), and a radiator. The aim of this PTMS is to keep electronics on a vehicle within their temperature limits (0 and 50 C for the current design) during all mission phases including multiple lunar day/night cycles. The VCHP was tested to verify its thermal performance. I created a thermal math model using Thermal Desktop (TD) and analyzed it to predict the PTMS performance. After testing, the test data provided a means to correlate the thermal math model. This correlation took into account conduction and convection heat transfer, representing the actual benchtop test. Since this PTMS is proposed for space missions, a vacuum test will be taking place to provide confidence that the system is functional in space environments. Therefore, the model was modified to include a vacuum chamber with a liquid nitrogen shroud while taking into account conduction and radiation heat transfer. Infrared Lamps were modelled and introduced into the model to simulate the sun

  15. Ionic-Liquid-Tethered Nanoparticles: Hybrid Electrolytes

    KAUST Repository

    Moganty, Surya S.

    2010-10-22

    A new class of solventless electrolytes was created by tethering ionic liquids to hard inorganic ZrO2 nanostructures (see picture; NIM=nanoscale ionic material). These hybrid fluids exhibit exceptional redox stability windows, excellent thermal stability, good lithium transference numbers, long-term interfacial stability in the presence of a lithium anode and, when doped with lithium salt, reasonable ionic conductivities.

  16. Continuity controlled Hybrid Automata

    NARCIS (Netherlands)

    Bergstra, J.A.; Middelburg, C.A.

    We investigate the connections between the process algebra for hybrid systems of Bergstra and Middelburg and the formalism of hybrid automata of Henzinger et al. We give interpretations of hybrid automata in the process algebra for hybrid systems and compare them with the standard interpretation

  17. Continuity Controlled Hybrid Automata

    NARCIS (Netherlands)

    Bergstra, J.A.; Middelburg, C.A.

    2004-01-01

    We investigate the connections between the process algebra for hybrid systems of Bergstra and Middelburg and the formalism of hybrid automata of Henzinger et al. We give interpretations of hybrid automata in the process algebra for hybrid systems and compare them with the standard interpretation of

  18. Continuity controlled hybrid automata

    NARCIS (Netherlands)

    Bergstra, J.A.; Middelburg, C.A.

    2004-01-01

    We investigate the connections between the process algebra for hybrid systems of Bergstra and Middelburg and the formalism of hybrid automata of Henzinger et al. We give interpretations of hybrid automata in the process algebra for hybrid systems and compare them with the standard interpretation of

  19. Continuity controlled hybrid automata

    NARCIS (Netherlands)

    Bergstra, J.A.; Middelburg, C.A.

    2006-01-01

    We investigate the connections between the process algebra for hybrid systems of Bergstra and Middelburg and the formalism of hybrid automata of Henzinger et al. We give interpretations of hybrid automata in the process algebra for hybrid systems and compare them with the standard interpretation of

  20. Hybrid fuel cells technologies for electrical microgrids

    Energy Technology Data Exchange (ETDEWEB)

    San Martin, Jose Ignacio; Zamora, Inmaculada; San Martin, Jose Javier; Aperribay, Victor; Eguia, Pablo [Department of Electrical Engineering, University of the Basque Country, Alda. de Urquijo, s/n, 48013 Bilbao (Spain)

    2010-09-15

    Hybrid systems are characterized by containing two or more electrical generation technologies, in order to optimize the global efficiency of the processes involved. These systems can present different operating modes. Besides, they take into account aspects that not only concern the electrical and thermal efficiencies, but also the reduction of pollutant emissions. There is a wide range of possible configurations to form hybrid systems, including hydrogen, renewable energies, gas cycles, vapour cycles or both. Nowadays, these technologies are mainly used for energy production in electrical microgrids. Some examples of these technologies are: hybridization processes of fuel cells with wind turbines and photovoltaic plants, cogeneration and trigeneration processes that can be configured with fuel cell technologies, etc. This paper reviews and analyses the main characteristics of electrical microgrids and the systems based on fuel cells for polygeneration and hybridization processes. (author)

  1. Thermo-economic optimization of the impact of renewable generators on poly-generation smart-grids including hot thermal storage

    International Nuclear Information System (INIS)

    Rivarolo, M.; Greco, A.; Massardo, A.F.

    2013-01-01

    Highlights: ► We model a poly-generation grid including thermal storage and renewable generators. ► We analyze the impact of random renewable generators on the grid performance. ► We carry out the grid optimization using a time-dependent thermo-economic approach. ► We present the importance of the storage system to optimize the RES impact. - Abstract: In this paper, the impact of not controllable renewable energy generators (wind turbines and solar photovoltaic panels) on the thermo-economic optimum performance of poly-generation smart grids is investigated using an original time dependent hierarchical approach. The grid used for the analysis is the one installed at the University of Genoa for research activities. It is based on different prime movers: (i) 100 kWe micro gas turbine, (ii) 20 kWe internal combustion engine powered by gases to produce both electrical and thermal (hot water) energy and (iii) a 100 kWth adsorption chiller to produce cooling (cold water) energy. The grid includes thermal storage tanks to manage the thermal demand load during the year. The plant under analysis is also equipped with two renewable non-controllable generators: a small size wind turbine and photovoltaic solar panels. The size and the management of the system studied in this work have been optimized, in order to minimize both capital and variable costs. A time-dependent thermo-economic hierarchical approach developed by the authors has been used, considering the time-dependent electrical, thermal and cooling load demands during the year as problem constraints. The results are presented and discussed in depth and show the strong interaction between fossil and renewable resources, and the importance of an appropriate storage system to optimize the RES impact taking into account the multiproduct character of the grid under investigation.

  2. Corporate Hybrid Bonds

    OpenAIRE

    Ahlberg, Johan; Jansson, Anton

    2016-01-01

    Hybrid securities do not constitute a new phenomenon in the Swedish capital markets. Most commonly, hybrids issued by Swedish real estate companies in recent years are preference shares. Corporate hybrid bonds on the other hand may be considered as somewhat of a new-born child in the family of hybrid instruments. These do, as all other hybrid securities, share some equity-like and some debt-like characteristics. Nevertheless, since 2013 the interest for the instrument has grown rapidly and ha...

  3. A hybrid air conditioner driven by a hybrid solar collector

    Science.gov (United States)

    Al-Alili, Ali

    The objective of this thesis is to search for an efficient way of utilizing solar energy in air conditioning applications. The current solar Air Conditioners (A/C)s suffer from low Coefficient of Performance (COP) and performance degradation in hot and humid climates. By investigating the possible ways of utilizing solar energy in air conditioning applications, the bottlenecks in these approaches were identified. That resulted in proposing a novel system whose subsystem synergy led to a COP higher than unity. The proposed system was found to maintain indoor comfort at a higher COP compared to the most common solar A/Cs, especially under very hot and humid climate conditions. The novelty of the proposed A/C is to use a concentrating photovoltaic/thermal collector, which outputs thermal and electrical energy simultaneously, to drive a hybrid A/C. The performance of the hybrid A/C, which consists of a desiccant wheel, an enthalpy wheel, and a vapor compression cycle (VCC), was investigated experimentally. This work also explored the use of a new type of desiccant material, which can be regenerated with a low temperature heat source. The experimental results showed that the hybrid A/C is more effective than the standalone VCC in maintaining the indoor conditions within the comfort zone. Using the experimental data, the COP of the hybrid A/C driven by a hybrid solar collector was found to be at least double that of the current solar A/Cs. The innovative integration of its subsystems allows each subsystem to do what it can do best. That leads to lower energy consumption which helps reduce the peak electrical loads on electric utilities and reduces the consumer operating cost since less energy is purchased during the on peak periods and less solar collector area is needed. In order for the proposed A/C to become a real alternative to conventional systems, its performance and total cost were optimized using the experimentally validated model. The results showed that for an

  4. Hybrid XRF

    International Nuclear Information System (INIS)

    Heckel, J.

    2002-01-01

    Full text: In the last 10 years significant innovations of EDXRF, e.g. total reflection XRF or polarized beam XRF, were utilized in different industrial applications. The decrease of background within the spectra was the goal of these developments. Excellent detection limits and sensitivities demonstrate the success of these new techniques. Nevertheless, further improvements are possible by using Si drift detectors. These detectors allow the processing of input count rates up to 10 6 cps in comparison to 10 5 of Si(Li) detectors. New excitation optics are necessary to produce such count rates. One possibility is the use of doubly curved crystals between tube and sample. These crystals enable the reflection of the primary beam within the given solid angle (0.4π) of an end window tube to the sample. Using such brightness optics excellent sensitivities mainly for light elements are achievable. The combination of a BRAGG crystal as a wavelength dispersive component and a solid state detector as an energy dispersive component creates a new technique: hybrid XRF. Copyright (2002) Australian X-ray Analytical Association Inc. Copyright (2002) Australian X-ray Analytical Association Inc

  5. Hydrogen hybrid vehicle engine development: Experimental program

    Energy Technology Data Exchange (ETDEWEB)

    Van Blarigan, P. [Sandia National Lab., Livermore, CA (United States)

    1995-09-01

    A hydrogen fueled engine is being developed specifically for the auxiliary power unit (APU) in a series type hybrid vehicle. Hydrogen is different from other internal combustion (IC) engine fuels, and hybrid vehicle IC engine requirements are different from those of other IC vehicle engines. Together these differences will allow a new engine design based on first principles that will maximize thermal efficiency while minimizing principal emissions. The experimental program is proceeding in four steps: (1) Demonstration of the emissions and the indicated thermal efficiency capability of a standard CLR research engine modified for higher compression ratios and hydrogen fueled operation. (2) Design and test a new combustion chamber geometry for an existing single cylinder research engine, in an attempt to improve on the baseline indicated thermal efficiency of the CLR engine. (3) Design and build, in conjunction with an industrial collaborator, a new full scale research engine designed to maximize brake thermal efficiency. Include a full complement of combustion diagnostics. (4) Incorporate all of the knowledge thus obtained in the design and fabrication, by an industrial collaborator, of the hydrogen fueled engine for the hybrid vehicle power train illustrator. Results of the CLR baseline engine testing are presented, as well as preliminary data from the new combustion chamber engine. The CLR data confirm the low NOx produced by lean operation. The preliminary indicated thermal efficiency data from the new combustion chamber design engine show an improvement relative to the CLR engine. Comparison with previous high compression engine results shows reasonable agreement.

  6. Hybrid mimics and hybrid vigor in Arabidopsis

    Science.gov (United States)

    Wang, Li; Greaves, Ian K.; Groszmann, Michael; Wu, Li Min; Dennis, Elizabeth S.; Peacock, W. James

    2015-01-01

    F1 hybrids can outperform their parents in yield and vegetative biomass, features of hybrid vigor that form the basis of the hybrid seed industry. The yield advantage of the F1 is lost in the F2 and subsequent generations. In Arabidopsis, from F2 plants that have a F1-like phenotype, we have by recurrent selection produced pure breeding F5/F6 lines, hybrid mimics, in which the characteristics of the F1 hybrid are stabilized. These hybrid mimic lines, like the F1 hybrid, have larger leaves than the parent plant, and the leaves have increased photosynthetic cell numbers, and in some lines, increased size of cells, suggesting an increased supply of photosynthate. A comparison of the differentially expressed genes in the F1 hybrid with those of eight hybrid mimic lines identified metabolic pathways altered in both; these pathways include down-regulation of defense response pathways and altered abiotic response pathways. F6 hybrid mimic lines are mostly homozygous at each locus in the genome and yet retain the large F1-like phenotype. Many alleles in the F6 plants, when they are homozygous, have expression levels different to the level in the parent. We consider this altered expression to be a consequence of transregulation of genes from one parent by genes from the other parent. Transregulation could also arise from epigenetic modifications in the F1. The pure breeding hybrid mimics have been valuable in probing the mechanisms of hybrid vigor and may also prove to be useful hybrid vigor equivalents in agriculture. PMID:26283378

  7. Development of Scaling Algorithms and Economic Evaluation for Non-Thermal Plasma Reactors - Adsorbant/Catalyzer Hybrid System for Control of NOx Released During Army and Related U.S. Department of Defense (DOD) Operations

    National Research Council Canada - National Science Library

    Urashima, K

    1998-01-01

    Computer code (SUENTP-J) to predict scale-up and economic evaluation of several eligible non-thermal plasma processes for air pollution control - electron beam process, pulsed corona process, and corona radical shower...

  8. Non-electrical uses of thermal energy generated in the production of fissile fuel in fusion--fission reactors: a comparative economic parametric analysis for a hybrid with or without synthetic fuel production

    International Nuclear Information System (INIS)

    Tai, A.S.; Krakowski, R.A.

    1979-01-01

    A parametric analysis has been carried out for testing the sensitivity of the synfuel production cost in relation to crucial economic and technologic quantities (investment costs of hybrid and synfuel plant, energy multiplication of the fission blanket, recirculating power fraction of the fusion driver, etc.). In addition, a minimum synfuel selling price has been evaluated, from which the fission--fusion--synfuel complex brings about a higher economic benefit than does the fusion--fission hybrid entirely devoted to fissile-fuel and electricity generation. Assuming an electricity cost of 2.7 cents/kWh, an annual investment cost per power unit of 4.2 to 6 $/GJ (132 to 189 k$/MWty) for the fission--fusion complex and 1.5 to 3 $/GJ (47 to 95 k$/MWty) for the synfuel plant, the synfuel production net cost (i.e., revenue = cost) varies between 6.5 and 8.6 $/GJ. These costs can compete with those obtained by other processes (natural gas reforming, resid partial oxidation, coal gasification, nuclear fission, solar electrolysis, etc.). This study points out a potential use of the fusion--fission hybrid other than fissile-fuel and electricity generation

  9. Performance investigation of a wind turbine–solar photovoltaic panels–fuel cell hybrid system installed at İncek region – Ankara, Turkey

    International Nuclear Information System (INIS)

    Devrim, Yılser; Bilir, Levent

    2016-01-01

    Highlights: • A hybrid system with a wind turbine, photovoltaic panels and a fuel cell was studied. • 3 kW wind turbine, 17.97 m 2 photovoltaics, 1.2 kW fuel cell and 4.7 kW electrolyzer was used. • The system can meet the entire demand of a residential house in Ankara, Turkey. • Only exception is in November, when the energy lack can be compensated from the grid. - Abstract: Renewable energy use in the world increases year by year. However, in many cases it is not possible to cover the electrical energy need of even a single house using only one renewable energy resource due to its intermittent nature. At this point, hybrid systems are applied to overcome this problem. This study focuses on the combination of photovoltaic solar panels, a small scale wind turbine, an electrolyzer and a proton exchange membrane fuel cell hybrid system for electrical power generation for an average house of 150 m 2 located at İncek region of Ankara, Turkey. Solar and wind energies were used as primary sources and a proton exchange membrane fuel cell is used as the backup power. The hybrid system was modeled and the results indicate that the use of the selected wind turbine with a 3 kW capacity along with photovoltaic panels with 17.97 m 2 area is sufficient to provide the required 5 h operation of the electrolyzer, which in turn provides the necessary hydrogen and oxygen to the fuel cell. Since the daily energy needed by the investigated house was taken as 5 kW h, the fuel cell with a net power output of 1 kW supplies all electrical demand with its 5 h operation. The outcomes show that the hybrid system is capable to provide all electrical need of the house all year round, except November. The electrical energy production of the proposed system is considerably higher than the demand in many months and this surplus electricity can be used in order to support the cooling and heating system of the considered house.

  10. Thermal comfort

    CSIR Research Space (South Africa)

    Osburn, L

    2010-01-01

    Full Text Available Thermal comfort is influenced by environmental parameters as well as other influences including asymmetric heating and cooling conditions. Additionally, some aspects of thermal comfort may be exploited so as to enable a building to operate within a...

  11. Thermal effects in supercapacitors

    CERN Document Server

    Xiong, Guoping; Fisher, Timothy S

    2015-01-01

    This Brief reviews contemporary research conducted in university and industry laboratories on thermal management in electrochemical energy storage systems (capacitors and batteries) that have been widely used as power sources in many practical applications, such as automobiles, hybrid transport, renewable energy installations, power backup and electronic devices. Placing a particular emphasis on supercapacitors, the authors discuss how supercapacitors, or ultra capacitors, are complementing and  replacing, batteries because of their faster power delivery, longer life cycle and higher coulombic efficiency, while providing higher energy density than conventional electrolytic capacitors. Recent advances in both macro- and micro capacitor technologies are covered. The work facilitates systematic understanding of thermal transport in such devices that can help develop better power management systems.

  12. Graphene hybridization for energy storage applications.

    Science.gov (United States)

    Li, Xianglong; Zhi, Linjie

    2018-05-08

    Graphene has attracted considerable attention due to its unique two-dimensional structure, high electronic mobility, exceptional thermal conductivity, excellent optical transmittance, good mechanical strength, and ultrahigh surface area. To meet the ever increasing demand for portable electronic products, electric vehicles, smart grids, and renewable energy integrations, hybridizing graphene with various functions and components has been demonstrated to be a versatile and powerful strategy to significantly enhance the performance of various energy storage systems such as lithium-ion batteries, supercapacitors and beyond, because such hybridization can result in synergistic effects that combine the best merits of involved components and confer new functions and properties, thereby improving the charge/discharge efficiencies and capabilities, energy/power densities, and cycle life of these energy storage systems. This review will focus on diverse graphene hybridization principles and strategies for energy storage applications, and the proposed outline is as follows. First, graphene and its fundamental properties, followed by graphene hybrids and related hybridization motivation, are introduced. Second, the developed hybridization formulas of using graphene for lithium-ion batteries are systematically categorized from the viewpoint of material structure design, bulk electrode construction, and material/electrode collaborative engineering; the latest representative progress on anodes and cathodes of lithium-ion batteries will be reviewed following such classifications. Third, similar hybridization formulas for graphene-based supercapacitor electrodes will be summarized and discussed as well. Fourth, the recently emerging hybridization formulas for other graphene-based energy storage devices will be briefed in combination with typical examples. Finally, future prospects and directions on the exploration of graphene hybridization toward the design and construction of

  13. Hybrid solar central receiver for combined cycle power plant

    Science.gov (United States)

    Bharathan, Desikan; Bohn, Mark S.; Williams, Thomas A.

    1995-01-01

    A hybrid combined cycle power plant including a solar central receiver for receiving solar radiation and converting it to thermal energy. The power plant includes a molten salt heat transfer medium for transferring the thermal energy to an air heater. The air heater uses the thermal energy to preheat the air from the compressor of the gas cycle. The exhaust gases from the gas cycle are directed to a steam turbine for additional energy production.

  14. Experimental Study on Productivity Performance of Household Combined Thermal Power and Biogas System in Northwest China

    Directory of Open Access Journals (Sweden)

    Jian Kang

    2018-01-01

    Full Text Available Ample quantities of solar and local biomass energy are available in the rural regions of northwest China to satisfy the energy needs of farmers. In this work, low-temperature solar thermal collectors, photovoltaic solar power generators, and solar-powered thermostatic biogas digesters were combined to create a heat, electricity, and biogas cogeneration system and were experimentally studied through two buildings in a farming village in northwestern China. The results indicated that the floor heater had the best heating effect. And the fraction of the energy produced by the solar elements of the system was 60.3%. The photovoltaic power-generation system achieved photovoltaic (PV conversion efficiencies of 8.3% and 8.1% during the first and second season, respectively. The intrinsic power consumption of the system was 143.4 kW·h, and 115.7 kW·h of electrical power was generated by the system in each season. The average volume of biogas produced daily was approximately 1.0 m3. Even though the ambient temperature reached −25°C, the temperature of the biogas digester was maintained at 27°C ± 2 for thermostatic fermentation. After optimization, the energy-saving rate improved from 66.2% to 85.5%. The installation reduced CO2 emissions by approximately 27.03 t, and the static payback period was 3.1 yr. Therefore, the system is highly economical, energy efficient, and beneficial for the environment.

  15. Experimental Study on Productivity Performance of Household Combined Thermal Power and Biogas System in Northwest China

    Science.gov (United States)

    Zhen, Xiaofei; Osman, Yassir Idris Abdalla; Feng, Rong; Si, Zetian

    2018-01-01

    Ample quantities of solar and local biomass energy are available in the rural regions of northwest China to satisfy the energy needs of farmers. In this work, low-temperature solar thermal collectors, photovoltaic solar power generators, and solar-powered thermostatic biogas digesters were combined to create a heat, electricity, and biogas cogeneration system and were experimentally studied through two buildings in a farming village in northwestern China. The results indicated that the floor heater had the best heating effect. And the fraction of the energy produced by the solar elements of the system was 60.3%. The photovoltaic power-generation system achieved photovoltaic (PV) conversion efficiencies of 8.3% and 8.1% during the first and second season, respectively. The intrinsic power consumption of the system was 143.4 kW·h, and 115.7 kW·h of electrical power was generated by the system in each season. The average volume of biogas produced daily was approximately 1.0 m3. Even though the ambient temperature reached −25°C, the temperature of the biogas digester was maintained at 27°C ± 2 for thermostatic fermentation. After optimization, the energy-saving rate improved from 66.2% to 85.5%. The installation reduced CO2 emissions by approximately 27.03 t, and the static payback period was 3.1 yr. Therefore, the system is highly economical, energy efficient, and beneficial for the environment. PMID:29862289

  16. Hybrid dry cooling. Enhanced energy efficiency in steam turbines. Hybride Trockenkuehlung. Bessere Energienutzung bei Dampfturbinen

    Energy Technology Data Exchange (ETDEWEB)

    Stucki, R. (Colenco Power Consulting AG, Baden (Switzerland)); Mueller, W. (Jaeggi AG, Bern (Switzerland)); Haltiner, E.W.

    1992-09-11

    Condensation turbo groups facilitate the utilization of thermal energy from vapor production plants, for example from garbage incineration. Through an optimum design of the cooling system, the profitable electric energy can be increased through the maximum spreading of the condensation temperature and the live steam temperature. The hybrid dry cooling guarantees unsurpassable operating conditions. (orig.).

  17. Hybrid Management in Hospitals

    DEFF Research Database (Denmark)

    Byrkjeflot, Haldor; Jespersen, Peter Kragh

    2010-01-01

    Artiklen indeholder et litteraturbaseret studium af ledelsesformer i sygehuse, hvor sundhedsfaglig ledelse og generel ledelse mikses til hybride ledelsesformer......Artiklen indeholder et litteraturbaseret studium af ledelsesformer i sygehuse, hvor sundhedsfaglig ledelse og generel ledelse mikses til hybride ledelsesformer...

  18. Hydraulic Hybrid Vehicles

    Science.gov (United States)

    EPA and the United Parcel Service (UPS) have developed a hydraulic hybrid delivery vehicle to explore and demonstrate the environmental benefits of the hydraulic hybrid for urban pick-up and delivery fleets.

  19. Flame-resistant pure and hybrid woven fabrics from basalt

    Science.gov (United States)

    Jamshaid, H.; Mishra, R.; Militky, J.

    2017-10-01

    This work has been formulated to investigate the burning behavior of different type of fabrics. The main concentration is to see how long the fabric resists after it catches the fire and the propagation of fire can be reduced by using flame resistant fiber i.e basalt. Basalt fiber is an environmental friendly material with low input, high output, low energy consumption and less emission. The goal of present investigations is to show the dependence of fabric flammability on its structure parameters i.e weave type, blend type etc. Fabric weaves have strong effect on flammability properties. Plain weave has the lowest burning rate as the density of the plain weave fabric is more and the structure is tight which gives less chances of flame passing through the fabric. Thermal stability is evaluated with TGA of all hybrid and nonhybrid fabrics and compared. The thermal stability of the basalt fiber is excellent. When comparing thermal analysis curves for hybrid samples it demonstrates that thermal stability of the samples containing basalt is much higher than the non- hybrid samples. Percentage weight loss is less in hybrid samples as compared to non-hybrid samples. The effectiveness of hybridization on samples may be indicated by substantial lowering of the decomposition mass. Correlation was made between flammability with the infrared radiations (IR)

  20. Mesoscale hybrid calibration artifact

    Science.gov (United States)

    Tran, Hy D.; Claudet, Andre A.; Oliver, Andrew D.

    2010-09-07

    A mesoscale calibration artifact, also called a hybrid artifact, suitable for hybrid dimensional measurement and the method for make the artifact. The hybrid artifact has structural characteristics that make it suitable for dimensional measurement in both vision-based systems and touch-probe-based systems. The hybrid artifact employs the intersection of bulk-micromachined planes to fabricate edges that are sharp to the nanometer level and intersecting planes with crystal-lattice-defined angles.

  1. Solar thermal power plants

    International Nuclear Information System (INIS)

    Schnatbaum, L.

    2009-01-01

    The solar thermal power plant technology, the opportunities it presents and the developments in the market are outlined. The focus is on the technology of parabolic trough power plants, a proven technology for solar power generation on a large scale. In a parabolic trough power plant, trough-shaped mirrors concentrate the solar irradiation onto a pipe in the focal line of the collector. The thermal energy thus generated is used for electricity generation in a steam turbine. Parabolic trough plants can be combined with thermal storage and fossil or biomass fired heat exchangers to generate electricity even when the sun is not shining. Solar Millennium AG in Erlangen has developed the first power plant of this kind in Europe. After two years of construction the plant started operation in Southern Spain in 2008. This one and its sister projects are important steps leading the way for the whole market. The paper also covers the technological challenges, the key components used and the research and development activities concerning this technology. Solar thermal power plants are ideal for covering peak and medium loads in power grids. In hybrid operation they can also cover base-load. The Solar Chimney power plant, another striking technology for the conversion of solar into electric energy, is described briefly. The paper concludes with a look at the future - the import of solar energy from the deserts of North Africa to central Europe. (author)

  2. Hybrid quantum information processing

    Energy Technology Data Exchange (ETDEWEB)

    Furusawa, Akira [Department of Applied Physics, School of Engineering, The University of Tokyo (Japan)

    2014-12-04

    I will briefly explain the definition and advantage of hybrid quantum information processing, which is hybridization of qubit and continuous-variable technologies. The final goal would be realization of universal gate sets both for qubit and continuous-variable quantum information processing with the hybrid technologies. For that purpose, qubit teleportation with a continuousvariable teleporter is one of the most important ingredients.

  3. Thermal Strain-Induced Temperature Compensation of Diode Lasers

    National Research Council Canada - National Science Library

    Coldren, L

    2000-01-01

    .... The hybrid approach that we will describe makes use of a submount of dimensions comparable to those used on standard laser manufacturing, but made from a material chosen for a specific thermal...

  4. Thermal Strain Induced Temperature Compensation of Diode Lasers

    National Research Council Canada - National Science Library

    Coldren, L

    2000-01-01

    .... The hybrid approach that we will describe makes use of a submount of laser manufacturing, but made from a material chosen for a specific thermal expansion coefficient, either high or low compared...

  5. Hybrid window layer for photovoltaic cells

    Science.gov (United States)

    Deng, Xunming

    2010-02-23

    A novel photovoltaic solar cell and method of making the same are disclosed. The solar cell includes: at least one absorber layer which could either be a lightly doped layer or an undoped layer, and at least a doped window-layers which comprise at least two sub-window-layers. The first sub-window-layer, which is next to the absorber-layer, is deposited to form desirable junction with the absorber-layer. The second sub-window-layer, which is next to the first sub-window-layer, but not in direct contact with the absorber-layer, is deposited in order to have transmission higher than the first-sub-window-layer.

  6. Development of Thermally Actuated, High Temperature Composite Morphing Concepts

    Science.gov (United States)

    2016-03-31

    set of applications exists in gas turbine engines, which stand to benefit greatly from aerodynamic control in their combustors, turbines, and nozzles...Modelling Development 27 3.1 Mechanics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 3.1.1 Achieving Snap-Through Behaviour ...Fabrication of Hybrid Laminate Shell and Strip Specimens . . . . . . 35 3.3.2 Measurement of Thermal Curvatures and Snap-Through Behaviour of Hybrid

  7. Development of Thermally Actuated, High-Temperature Composite Morphing Concepts

    Science.gov (United States)

    2016-05-11

    set of applications exists in gas turbine engines, which stand to benefit greatly from aerodynamic control in their combustors, turbines, and nozzles...Modelling Development 27 3.1 Mechanics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 3.1.1 Achieving Snap-Through Behaviour ...Fabrication of Hybrid Laminate Shell and Strip Specimens . . . . . . 35 3.3.2 Measurement of Thermal Curvatures and Snap-Through Behaviour of Hybrid

  8. Thermal insulation

    International Nuclear Information System (INIS)

    Aspden, G.J.; Howard, R.S.

    1988-01-01

    The patent concerns high temperature thermal insulation of large vessels, such as the primary vessel of a liquid metal cooled nuclear reactor. The thermal insulation consists of multilayered thermal insulation modules, and each module comprises a number of metal sheet layers sandwiched between a back and front plate. The layers are linked together by straps and clips to control the thickness of the module. (U.K.)

  9. Study of electrical and thermal characteristics of inverters for grid-connected photovoltaic systems; Estudo de caracteristicas eletricas e termicas de inversores para sistemas fotovoltaicos conectados a rede

    Energy Technology Data Exchange (ETDEWEB)

    Rampinelli, Giuliano Arns

    2010-12-15

    Grid-connected photovoltaic systems directly convert solar energy into electrical energy delivering to the distribution grid a clean and renewable energy. These systems are basically formed by an array of photovoltaic modules and inverters. The inverters are responsible for converting direct current to alternating current. A study of electrical and thermal characteristics of inverters used in grid-connected photovoltaic systems from a theoretical and experimental analysis. The inverters tests were carried out in two stages: the first stage was performed at Solar Energy Lab. of the Federal University of Rio Grande do Sul (UFRGS), Brazil, where it was used a 4,8 kW{sub p} grid-connected photovoltaic system and ten inverters of different manufacturers. The inverters electrical characteristics measured and analyzed were: direct current to alternating current conversion efficiency, maximum power point tracker efficiency, power factor and harmonic distortion in current and voltage. Inverters thermal testing was also conducted and its results are presented ana analyzed. The second stage of the experimental tests was performed at Photovoltaic Solar Energy Lab. at CIEMAT in Spain. It was used 3 kW{sub p} photovoltaic system and seven inverters of different manufacturers. The inverters are single-phase, up to 5 kW and different topologies (high frequency transformer, low frequency transformer and transformerless). The influence of DC voltage input in the behavior of DC to AC conversion efficiency and power factor was analyzed. The results of the tests allowed the development of mathematical models that describe the electrical and thermal behavior of the inverters. The proposed mathematical models were inserted into computer simulation software developed at UFRGS named FVConect. The evolution of the simulation results compared to the experimental results validates the proposed models. The analysis of the behavior of the inverters improves the understanding of the operating os

  10. Anticorrosive organic/inorganic hybrid coatings

    Science.gov (United States)

    Gao, Tongzhai

    Organic/inorganic hybrid coating system was developed for anticorrosion applications using polyurea, polyurethane or epoxide as the organic phase and polysiloxane, formed by sol-gel process, as the inorganic phase. Polyurea/polysiloxane hybrid coatings were formulated and moisture cured using HDI isocyanurate, alkoxysilane-functionalized HDI isocyanurate, and tetraethyl orthosilicate (TEOS) oligomers. Two urethanes were prepared using the same components as abovementioned in addition to the oligoesters derived from either cyclohexane diacids (CHDA) and 2-butyl-2-ethyl-1,3-propanediol (BEPD) or adipic acid (AA), isophthalic acid (IPA), 1,6-hexanediol (HD), and trimethylol propane (TMP). Accelerated weathering and outdoor exposure were performed to study the weatherability of the polyurethane/polysiloxane hybrid coating system. FTIR and solid-state 13C NMR revealed that the degradation of the hybrid coatings occurred at the urethane and ester functionalities of the organic phase. DMA and DSC analyses showed the glass transition temperature increased and broadened after weathering. SEM was employed to observe the change of morphology of the hybrid coatings and correlated with the gloss variation after weathering. Rutile TiO2 was formulated into polyurethane/polysiloxane hybrid coatings in order to investigate the effect of pigmentation on the coating properties and the sol-gel precursor. Chemical interaction between the TiO2 and the sol-gel precursor was investigated using solid-state 29Si NMR and XPS. The morphology, mechanical, viscoelastic, thermal properties of the pigmented coatings were evaluated as a function of pigmentation volume concentration (PVC). Using AFM and SEM, the pigment were observed to be well dispersed in the polymer matrix. The thermal stability, the tensile modulus and strength of the coatings were enhanced with increasing PVC, whereas the pull-off adhesion and flexibility were reduced with increasing PVC. Finally, the pigmented coatings were

  11. Marine Fish Hybridization

    KAUST Repository

    He, Song

    2017-04-01

    Natural hybridization is reproduction (without artificial influence) between two or more species/populations which are distinguishable from each other by heritable characters. Natural hybridizations among marine fishes were highly underappreciated due to limited research effort; it seems that this phenomenon occurs more often than is commonly recognized. As hybridization plays an important role in biodiversity processes in the marine environment, detecting hybridization events and investigating hybridization is important to understand and protect biodiversity. The first chapter sets the framework for this disseration study. The Cohesion Species Concept was selected as the working definition of a species for this study as it can handle marine fish hybridization events. The concept does not require restrictive species boundaries. A general history and background of natural hybridization in marine fishes is reviewed during in chapter as well. Four marine fish hybridization cases were examed and documented in Chapters 2 to 5. In each case study, at least one diagnostic nuclear marker, screened from among ~14 candidate markers, was found to discriminate the putative hybridizing parent species. To further investigate genetic evidence to support the hybrid status for each hybrid offspring in each case, haploweb analysis on diagnostic markers (nuclear and/or mitochondrial) and the DAPC/PCA analysis on microsatellite data were used. By combining the genetic evidences, morphological traits, and ecological observations together, the potential reasons that triggered each hybridization events and the potential genetic/ecology effects could be discussed. In the last chapter, sequences from 82 pairs of hybridizing parents species (for which COI barcoding sequences were available either on GenBank or in our lab) were collected. By comparing the COI fragment p-distance between each hybridizing parent species, some general questions about marine fish hybridization were discussed: Is

  12. 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%

  13. Nuclear Hybrid Energy System Model Stability Testing

    Energy Technology Data Exchange (ETDEWEB)

    Greenwood, Michael Scott [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Cetiner, Sacit M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Fugate, David W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-04-01

    A Nuclear Hybrid Energy System (NHES) uses a nuclear reactor as the basic power generation unit, and the power generated is used by multiple customers as combinations of thermal power or electrical power. The definition and architecture of a particular NHES can be adapted based on the needs and opportunities of different localities and markets. For example, locations in need of potable water may be best served by coupling a desalination plant to the NHES. Similarly, a location near oil refineries may have a need for emission-free hydrogen production. Using the flexible, multi-domain capabilities of Modelica, Argonne National Laboratory, Idaho National Laboratory, and Oak Ridge National Laboratory are investigating the dynamics (e.g., thermal hydraulics and electrical generation/consumption) and cost of a hybrid system. This paper examines the NHES work underway, emphasizing the control system developed for individual subsystems and the overall supervisory control system.

  14. Natural uranium fueled light water moderated breeding hybrid power reactors

    International Nuclear Information System (INIS)

    Greenspan, E.; Schneider, A.; Misolovin, A.; Gilai, D.; Levin, P.

    The feasibility of fission-fusion hybrid reactors based on breeding light water thermal fission systems is investigated. The emphasis is on fuel-self-sufficient (FSS) hybrid power reactors that are fueled with natural uranium. Other LWHRs considered include FSS-LWHRs that are fueled with spent fuel from LWRs, and LWHRs which are to supplement LWRs to provide a tandem LWR-LWHR power economy that is fuel-self-sufficient

  15. Probabilistic Analysis Methods for Hybrid Ventilation

    DEFF Research Database (Denmark)

    Brohus, Henrik; Frier, Christian; Heiselberg, Per

    This paper discusses a general approach for the application of probabilistic analysis methods in the design of ventilation systems. The aims and scope of probabilistic versus deterministic methods are addressed with special emphasis on hybrid ventilation systems. A preliminary application...... of stochastic differential equations is presented comprising a general heat balance for an arbitrary number of loads and zones in a building to determine the thermal behaviour under random conditions....

  16. Thermal insulation

    International Nuclear Information System (INIS)

    Pinsky, G.P.

    1977-01-01

    Thermal insulation for vessels and piping within the reactor containment area of nuclear power plants is disclosed. The thermal insulation of this invention can be readily removed and replaced from the vessels and piping for inservice inspection, can withstand repeated wettings and dryings, and can resist high temperatures for long periods of time. 4 claims, 3 figures

  17. Carboxylated nitrile butadiene rubber/hybrid filler composites

    Directory of Open Access Journals (Sweden)

    Ahmad Mousa

    2012-08-01

    Full Text Available The surface properties of the OSW and NLS are measured with the dynamic contact-angle technique. The x-ray photoelectron spectroscopy (XPS of the OSW reveals that the OSW possesses various reactive functional groups namely hydroxyl groups (OH. Hybrid filler from NLS and OSW were incorporated into carboxylated nitrile rubber (XNBR to produce XNBR hybrid composites. The reaction of OH groups from the OSW with COOH of the XNBR is checked by attenuated total reflectance spectra (ATR-IR of the composites. The degree of curing ΔM (maximum torque-minimum torque as a function of hybrid filler as derived from moving die rheometer (MDR is reported. The stress-strain behavior of the hybrid composites as well as the dynamic mechanical thermal analysis (DMTA is studied. Bonding quality and dispersion of the hybrid filler with and in XNBR are examined using scanning-transmission electron microscopy (STEM in SEM.

  18. Radiation sterilization of enzyme hybrids with biodegradable polymers

    International Nuclear Information System (INIS)

    Furuta, Masakazu; Oka, Masahito; Hayashi, Toshio

    2002-01-01

    Ionizing radiations, which have already been utilized for the sterilization of medical supplies as well as gas fumigation, should be the final candidate to decontaminate 'hybrid' biomaterials containing bio-active materials including enzymes because irradiation induces neither heat nor substances affecting the quality of the materials and our health. In order to check the feasibility of 60 Co-gamma rays on these materials, we selected commercial proteases including papain and bromelain hybridized with commercial activated chitosan beads and demonstrated that these enzyme-hybrids suspended in water showed the significant radiation durability of more than twice as much as free enzyme solution at 25-kGy irradiation. Enhanced thermal and storage stability of the enzyme hybrids were not affected by the same dose level of irradiation, either, indicating that commercial irradiation sterilization method is applicable to enzyme hybrids without modification

  19. Study of flax hybrid preforms reinforced epoxy composites

    International Nuclear Information System (INIS)

    Muralidhar, B. A

    2013-01-01

    Highlights: • We examine the thermal, viscoelastic and mechanical behaviour of flax preform hybrid composites. • The thermal stability of the matrix decrease with increasing volume fraction of flax preforms. • The effect of number of preform layers and the lay-up architecture were studied.. • Morphological study on the fractured surface of the composite laminate is carried out. - Abstracts: This study investigates the thermal, mechanical and thermomechanical properties of flax hybrid preform reinforced epoxy composites. Flax plain weave fabric and 1 × 1 weft rib knitted structures were together used as reinforcements and the composites were produced using hand lay-up technique. Specimen preparation and testing were carried out as per ASTM standards. Thermogravimetric analysis (TGA) indicates a decrease in thermal stability of the matrix polymer with the incorporation of flax hybrid preform. The dynamic mechanical analysis revealed a shift in the T g with the addition of flax hybrid preforms. Mechanical data obtained showed that tensile strength and stiffness is a product of the fibre/matrix synergy, whereas the compressive strength and stiffness are contributed by the reinforcing matrix. Additionally, investigation show that laminate with knitted preform as skin layer exhibits superior mechanical properties. However, improved tensile properties at lower fibre volume fraction, reinforces the opinion that hybrid preform composites can offer significant benefits in terms of performance, weight and overall cost. The failure mechanism was analysed, by scanning electron microscope (SEM)

  20. Henkin and Hybrid Logic

    DEFF Research Database (Denmark)

    Blackburn, Patrick Rowan; Huertas, Antonia; Manzano, Maria

    2014-01-01

    Leon Henkin was not a modal logician, but there is a branch of modal logic that has been deeply influenced by his work. That branch is hybrid logic, a family of logics that extend orthodox modal logic with special proposition symbols (called nominals) that name worlds. This paper explains why...... Henkin’s techniques are so important in hybrid logic. We do so by proving a completeness result for a hybrid type theory called HTT, probably the strongest hybrid logic that has yet been explored. Our completeness result builds on earlier work with a system called BHTT, or basic hybrid type theory...... is due to the first-order perspective, which lies at the heart of Henin’s best known work and hybrid logic....