Solar heating cooling. Preparation of possible participation in IEA, Solar Heating Cooling Task 25

International Nuclear Information System (INIS)

2001-03-01

For the Danish solar heating industries it is interesting to discuss the domestic market possibilities and the export possibilities for solar heating cooling systems. The Danish solar heating sector also wants to participate in the international collaboration within IEA Solar Heating and Cooling Task 25 'Solar Assisted Air Conditioning of Buildings'. The Danish Energy Agency therefore has granted means for this project to discuss: The price of cooling for 3 different solar cooling methods (absorption cooling, desiccant cooling and ejector cooling); Market possibilities in Denmark and abroad; The advantages by Danish participation in IEA Task 25. The task has been solved through literature studies to establish status for the 3 technologies. It turned out that ejector cooling by low temperatures (85 deg. C from the solar collector) exists as pilot plants in relation to district heating, but is still not commercial accessible. Desiccant cooling, where the supplied heat has temperatures down to 55 deg. C is a well-developed technology. However only a handful of pilot plants with solar heating exists, and thus optimization relating to operation strategy and economy is on the experimental stage. Absorption cooling plants driven by solar heating are found in a large number in Japan and are also demonstrated in several other countries. The combination of absorption heating pump and solar heating is considered to be commercial accessible. Solar heating is interesting as heat source of to the extent that it can replace other sources of heat without the economy being depreciated. This can be the case in South Europe if: 1) oil or natural gas is used for heating; 2) a solar heating system already exists, e.g. for domestic water supply, and is installed so that the marginal costs by solar heating supply of the ventilation plant is reduced. All in all the above conditions mean that the market for solar heating for cooling is very limited in Europe, where almost everybody are

Solar heat storages in district heating networks

Energy Technology Data Exchange (ETDEWEB)

Ellehauge, K. (Ellehauge og Kildemoes, AArhus (DK)); Engberg Pedersen, T. (COWI A/S, Kgs. Lyngby (DK))

2007-07-15

This report gives information on the work carried out and the results obtained in Denmark on storages for large solar heating plants in district heating networks. Especially in Denmark the share of district heating has increased to a large percentage. In 1981 around 33% of all dwellings in DK were connected to a district heating network, while the percentage in 2006 was about 60% (in total 1.5 mio. dwellings). In the report storage types for short term storage and long term storages are described. Short term storages are done as steel tanks and is well established technology widely used in district heating networks. Long term storages are experimental and used in connection with solar heating. A number of solar heating plants have been established with either short term or long term storages showing economy competitive with normal energy sources. Since, in the majority of the Danish district heating networks the heat is produced in co-generation plants, i.e. plants producing both electricity and heat for the network, special attention has been put on the use of solar energy in combination with co-generation. Part of this report describes that in the liberalized electricity market central solar heating plants can also be advantageous in combination with co-generation plants. (au)

Morphology and mechanical properties of multi-stranded amyloid fibrils probed by atomistic and coarse-grained simulations

International Nuclear Information System (INIS)

Yoon, Gwonchan; Lee, Myeongsang; Kim, Kyungwoo; In Kim, Jae; Joon Chang, Hyun; Baek, Inchul; Na, Sungsoo; Eom, Kilho

2015-01-01

Amyloid fibrils are responsible for pathogenesis of various diseases and exhibit the structural feature of an ordered, hierarchical structure such as multi-stranded helical structure. As the multi-strandedness of amyloid fibrils has recently been found to be highly correlated with their toxicity and infectivity, it is necessary to study how the hierarchical (i.e. multi-stranded) structure of amyloid fibril is formed. Moreover, although it has recently been reported that the nanomechanics of amyloid proteins plays a key role on the amyloid-induced pathogenesis, a critical role that the multi-stranded helical structure of the fibrils plays in their nanomechanical properties has not fully characterized. In this work, we characterize the morphology and mechanical properties of multi-stranded amyloid fibrils by using equilibrium molecular dynamics simulation and elastic network model. It is shown that the helical pitch of multi-stranded amyloid fibril is linearly proportional to the number of filaments comprising the amyloid fibril, and that multi-strandedness gives rise to improving the bending rigidity of the fibril. Moreover, we have also studied the morphology and mechanical properties of a single protofilament (filament) in order to understand the effect of cross-β structure and mutation on the structures and mechanical properties of amyloid fibrils. Our study sheds light on the underlying design principles showing how the multi-stranded amyloid fibril is formed and how the structure of amyloid fibrils governs their nanomechanical properties. (paper)

Solar Process Heat Basics | NREL

Science.gov (United States)

Process Heat Basics Solar Process Heat Basics Commercial and industrial buildings may use the same solar technologies-photovoltaics, passive heating, daylighting, and water heating-that are used for residential buildings. These nonresidential buildings can also use solar energy technologies that would be

Estimation of Prestress Force Distribution in Multi-Strand System of Prestressed Concrete Structures Using Field Data Measured by Electromagnetic Sensor.

Science.gov (United States)

Cho, Keunhee; Cho, Jeong-Rae; Kim, Sung Tae; Park, Sung Yong; Kim, Young-Jin; Park, Young-Hwan

2016-08-18

The recently developed smart strand can be used to measure the prestress force in the prestressed concrete (PSC) structure from the construction stage to the in-service stage. The higher cost of the smart strand compared to the conventional strand renders it unaffordable to replace all the strands by smart strands, and results in the application of only a limited number of smart strands in the PSC structure. However, the prestress forces developed in the strands of the multi-strand system frequently adopted in PSC structures differ from each other, which means that the prestress force in the multi-strand system cannot be obtained by simple proportional scaling using the measurement of the smart strand. Therefore, this study examines the prestress force distribution in the multi-strand system to find the correlation between the prestress force measured by the smart strand and the prestress force distribution in the multi-strand system. To that goal, the prestress force distribution was measured using electromagnetic sensors for various factors of the multi-strand system adopted on site in the fabrication of actual PSC girders. The results verified the possibility to assume normal distribution for the prestress force distribution per anchor head, and a method computing the mean and standard deviation defining the normal distribution is proposed. This paper presents a meaningful finding by proposing an estimation method of the prestress force based upon field-measured data of the prestress force distribution in the multi-strand system of actual PSC structures.

Large-scale solar heat

Energy Technology Data Exchange (ETDEWEB)

Tolonen, J.; Konttinen, P.; Lund, P. [Helsinki Univ. of Technology, Otaniemi (Finland). Dept. of Engineering Physics and Mathematics

1998-12-31

In this project a large domestic solar heating system was built and a solar district heating system was modelled and simulated. Objectives were to improve the performance and reduce costs of a large-scale solar heating system. As a result of the project the benefit/cost ratio can be increased by 40 % through dimensioning and optimising the system at the designing stage. (orig.)

Optimal Scheduling of Biogas-Solar-Wind Renewable Portfolio for Multi-Carrier Energy Supplies

DEFF Research Database (Denmark)

Zhou, Bin; Xu, Da; Li, Canbing

2018-01-01

the mitigation of renewable intermittency and the efficient utilization of batteries, and a multi-carrier generation scheduling scheme is further presented to dynamically optimize dispatch factors in the coupling matrix for energy-efficient con-version and storage, while different energy demands of end......This paper proposes a multi-source multi-product framework for coupled multi-carrier energy supplies with a biogas-solar-wind hybrid renewable system. In this framework, the biogas-solar-wind complementarities are fully exploited based on digesting thermodynamic effects for the synergetic...... interactions of electricity, gas and heating energy flows, and a coupling matrix is formulated for the modeling of production, conversion, storage, and consumption of different energy carriers. The multi-energy complementarity of biogas-solar-wind renewable portfolio can be utilized to facilitate...

Heat transfer and friction characteristics of rotor-assembled strand heat exchanger studied by uniform design experiment

Directory of Open Access Journals (Sweden)

Yan Wei

2015-10-01

Full Text Available The uniform distribution and experimental design is employed to study the thermo-hydraulic characteristics of a heat exchanger, which consists of the rotor-assembled strands mounted in circular smooth tubes. The uniform distribution and experimental design parameters include multiple rotor parameters such as rotor diameters, rotor lead, and height of blade, with the aim of studying their influence on the PEC, that is, ( ( Nu z / Nu g / ( f g / f z 1 / 3 , which stands for the heat transfer and friction characteristics. The best matching schemes of rotor-assembled strand, which significantly improves PEC to 2.01, are given by the regression analysis of uniform distribution and experimental design table. The single-factor experiments are performed to compare a tube installed with different kinds of rotor-assembled strands with a smooth tube without any strands when the Reynolds number changes between 20,000 and 60,000. The experimental result is in good agreement with the result obtained by the regression analysis of uniform distribution and experimental design. It is shown that the rotor diameters play important role in the heat transfer, and the optimal PEC value is obtained under the case that the rotor diameter is 21 mm. The rotor lead also contributes to the improvement of heat transfer and its optimal value is 700 mm in this study. The Nusselt number, friction factor and PEC increase with the increase in blade height. It shows that the uniform distribution and experimental design is an efficient method to find out the optimal parameters.

Passive solar heating

Energy Technology Data Exchange (ETDEWEB)

Wiberg, K

1981-11-10

The present work treats the possibilities for heating according to the passive solar heating method. Problems of 'spatial organization in an energy-saving society' are distinguished from among other social problems. The final delimination of the actual problems under investigation consists of the use of passive solar heating and especially the 'consequences of such solar heating exploitation upon the form and structures' of planning and construction. In the concluding chapter an applied example shows how this method can be used in designing an urban area and what are its limitations. The results indicate the possibilities and difficulties in attempting to transfer this ideal and general method into models and directives for form and structure from which examples of the actual possibilities in practical planning can be given.

An analysis of solar assisted ground source heat pumps in cold climates

International Nuclear Information System (INIS)

Emmi, Giuseppe; Zarrella, Angelo; De Carli, Michele; Galgaro, Antonio

2015-01-01

Highlights: • The work focuses on solar assisted ground source heat pump in cold climates. • Multi-year simulations of SAGSHP, are carried out in six cold locations. • GSHP and SAGSHP are compared. • The effect of total borehole length on the heat pump energy efficiency is studied. • A dedicated control strategy is used to manage both solar and ground loops. - Abstract: Exploiting renewable energy sources for air-conditioning has been extensively investigated over recent years, and many countries have been working to promote the use of renewable energy to decrease energy consumption and CO_2 emissions. Electrical heat pumps currently represent the most promising technology to reduce fossil fuel usage. While ground source heat pumps, which use free heat sources, have been taking significant steps forward and despite the fact that their energy performance is better than that of air source heat pumps, their development has been limited by their high initial investment cost. An alternative solution is one that uses solar thermal collectors coupled with a ground source heat pump in a so-called solar assisted ground source heat pump. A ground source heat pump system, used to heat environments located in a cold climate, was investigated in this study. The solar assisted ground source heat pump extracted heat from the ground by means of borehole heat exchangers and it injected excess solar thermal energy into the ground. Building load profiles are usually heating dominated in cold climates, but when common ground source heat pump systems are used only for heating, their performance decreases due to an unbalanced ground load. Solar thermal collectors can help to ensure that systems installed in cold zones perform more efficiently. Computer simulations using a Transient System Simulation (TRNSYS) tool were carried out in six cold locations in order to investigate solar assisted ground source heat pumps. The effect of the borehole length on the energy efficiency of

Mathematical model for solar-hydrogen heated desalination plant using humidification-dehumidification process

International Nuclear Information System (INIS)

Yassin, Jamal S.; Eljrushi, Gibril S.

2006-01-01

This paper presents a mathematical model for thermal desalination plant operating with solar energy and hydrogen. This plant is composed of two main systems, the heating system and the distillation system. The distillation system is composed of multi-cells; each cell is using the humidification-dehumidification (H-D) process in the distillation unit and getting the required amount of heat from feed seawater heater. The feed seawater heater is a heat exchanger used to raise the temperature of the preheated seawater coming from the condensation chamber (Dehumidifier) of each cell to about 85 degree centigrade. The heating amount in the heat exchangers is obtained from the thermal storage tank, which gets its energy from solar thermal system and is coupled with a hydrogen-fired backup system to guaranty necessary operating conditions and permit 24 hours solar H-D desalination plant to enhance the performance of this system. The mathematical model studies the performance of the proposed desalination system using thermal solar energy and hydrogen as fuel. Other pertinent variable in the heating and distillation system are also studied. The outcomes of this study are analyzed to enhance the used solar desalination process and make commercial.(Author)

Solar heating and cooling.

Science.gov (United States)

Duffie, J A

1976-01-01

Solar energy is discussed as an energy resource that can be converted into useful energy forms to meet a variety of energy needs. The review briefly explains the nature of this energy resource, the kinds of applications that can be made useful, and the status of several systems to which it has been applied. More specifically, information on solar collectors, solar water heating, solar heating of buildings, solar cooling plus other applications, are included.

Solar heating cooling. Preparation of possible participation in IEA, Solar Heating Cooling Task 25; Solvarmedrevet koeling. Forberedelse af evt. deltagelse i IEA, Solar Heating Cooling Task 25

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

For the Danish solar heating industries it is interesting to discuss the domestic market possibilities and the export possibilities for solar heating cooling systems. The Danish solar heating sector also wants to participate in the international collaboration within IEA Solar Heating and Cooling Task 25 'Solar Assisted Air Conditioning of Buildings'. The Danish Energy Agency therefore has granted means for this project to discuss: The price of cooling for 3 different solar cooling methods (absorption cooling, desiccant cooling and ejector cooling); Market possibilities in Denmark and abroad; The advantages by Danish participation in IEA Task 25. The task has been solved through literature studies to establish status for the 3 technologies. It turned out that ejector cooling by low temperatures (85 deg. C from the solar collector) exists as pilot plants in relation to district heating, but is still not commercial accessible. Desiccant cooling, where the supplied heat has temperatures down to 55 deg. C is a well-developed technology. However only a handful of pilot plants with solar heating exists, and thus optimization relating to operation strategy and economy is on the experimental stage. Absorption cooling plants driven by solar heating are found in a large number in Japan and are also demonstrated in several other countries. The combination of absorption heating pump and solar heating is considered to be commercial accessible. Solar heating is interesting as heat source of to the exent that it can replace other sources of heat without the economy being depreciated. This can be the case in South Europe if: 1) oil or natural gas is used for heating; 2) a solar heating system already exists, e.g. for domestic water supply, and is installed so that the marginal costs by solar heating supply of the ventilation plant is reduced. All in all the above conditions mean that the market for solar heating for cooling is very limited in Europe, where almost

German central solar heating plants with seasonal heat storage

Energy Technology Data Exchange (ETDEWEB)

Bauer, D.; Marx, R.; Nussbicker-Lux, J.; Ochs, F.; Heidemann, W. [Institute of Thermodynamics and Thermal Engineering (ITW), University of Stuttgart, Pfaffenwaldring 6, D-70550 Stuttgart (Germany); Mueller-Steinhagen, H. [Institute of Thermodynamics and Thermal Engineering (ITW), University of Stuttgart, Pfaffenwaldring 6, D-70550 Stuttgart (Germany); Institute of Technical Thermodynamics (ITT), German Aerospace Centre (DLR), Stuttgart (Germany)

2010-04-15

Central solar heating plants contribute to the reduction of CO{sub 2}-emissions and global warming. The combination of central solar heating plants with seasonal heat storage enables high solar fractions of 50% and more. Several pilot central solar heating plants with seasonal heat storage (CSHPSS) built in Germany since 1996 have proven the appropriate operation of these systems and confirmed the high solar fractions. Four different types of seasonal thermal energy stores have been developed, tested and monitored under realistic operation conditions: Hot-water thermal energy store (e.g. in Friedrichshafen), gravel-water thermal energy store (e.g. in Steinfurt-Borghorst), borehole thermal energy store (in Neckarsulm) and aquifer thermal energy store (in Rostock). In this paper, measured heat balances of several German CSHPSS are presented. The different types of thermal energy stores and the affiliated central solar heating plants and district heating systems are described. Their operational characteristics are compared using measured data gained from an extensive monitoring program. Thus long-term operational experiences such as the influence of net return temperatures are shown. (author)

Investigation on Solar Heating System with Building-Integrated Heat Storage

DEFF Research Database (Denmark)

Heller, Alfred

1996-01-01

Traditional solar heating systems cover between 5 and 10% of the heat demand fordomestic hot water and comfort heating. By applying storage capacity this share can beincreased much. The Danish producer of solar heating systems, Aidt-Miljø, markets such a system including storage of dry sand heated...... by PP-pipe heat exchanger. Heat demand is reduced due to direct solar heating and due to storage. The storage affects the heat demand passively due to higher temperatures. Hence heat loss is reduced and passive heating is optioned. In theory, by running the system flow backwards, active heating can...... solar collector area of the system, was achieved. Active heating from the sand storage was not observed. The pay-back time for the system can be estimated to be similar to solar heated domestic hot water systems in general. A number of minor improvements on the system could be pointed out....

MUSE: the Multi-Slit Solar Explorer

Science.gov (United States)

Tarbell, Theodore D.; De Pontieu, Bart

2017-08-01

The Multi-Slit Solar Explorer is a proposed Small Explorer mission for studying the dynamics of the corona and transition region using both conventional and novel spectral imaging techniques. The physical processes that heat the multi-million degree solar corona, accelerate the solar wind and drive solar activity (CMEs and flares) remain poorly known. A breakthrough in these areas can only come from radically innovative instrumentation and state-of-the-art numerical modeling and will lead to better understanding of space weather origins. MUSE’s multi-slit coronal spectroscopy will use a 100x improvement in spectral raster cadence to fill a crucial gap in our knowledge of Sun-Earth connections; it will reveal temperatures, velocities and non-thermal processes over a wide temperature range to diagnose physical processes that remain invisible to current or planned instruments. MUSE will contain two instruments: an EUV spectrograph (SG) and EUV context imager (CI). Both have similar spatial resolution and leverage extensive heritage from previous high-resolution instruments such as IRIS and the HiC rocket payload. The MUSE investigation will build on the success of IRIS by combining numerical modeling with a uniquely capable observatory: MUSE will obtain EUV spectra and images with the highest resolution in space (1/3 arcsec) and time (1-4 s) ever achieved for the transition region and corona, along 35 slits and a large context FOV simultaneously. The MUSE consortium includes LMSAL, SAO, Stanford, ARC, HAO, GSFC, MSFC, MSU, ITA Oslo and other institutions.

Compact seasonal PCM heat storage for solar heating systems

DEFF Research Database (Denmark)

Dannemand, Mark

Space heating of buildings and preparation of domestic hot water accounts for a large part of the society’s energy consumption. Solar radiation is an abundant and renewable energy source which can be harvested by solar collectors and used to cover heating demands in the built environment....... The seasonal availability of solar energy does however not match with the heating demands in buildings which typically are large in winter periods when limited solar energy is available. Heat can be stored over a few days in water stores but continuous heat losses limits the storage periods. The possibility...... of storing heat from summer where solar energy is widely available to winter periods where the heating demands are large, allows for implementing more renewable energy in our energy system. The phase change material (PCM) sodium acetate trihydrate (SAT) melts at 58 °C. The melting process requires...

SCALING LAWS AND TEMPERATURE PROFILES FOR SOLAR AND STELLAR CORONAL LOOPS WITH NON-UNIFORM HEATING

International Nuclear Information System (INIS)

Martens, P. C. H.

2010-01-01

The bulk of solar coronal radiative loss consists of soft X-ray emission from quasi-static loops at the cores of active regions. In order to develop diagnostics for determining the heating mechanism of these loops from observations by coronal imaging instruments, I have developed analytical solutions for the temperature structure and scaling laws of loop strands for a set of temperature- and pressure-dependent heating functions that encompass heating concentrated at the footpoints, uniform heating, and heating concentrated at the loop apex. Key results are that the temperature profile depends only weakly on the heating distribution-not sufficiently to be of significant diagnostic value-and that the scaling laws survive for this wide range of heating distributions, but with the constant of proportionality in the Rosner-Tucker-Vaiana scaling law (P 0 L ∼ T 3 max ) depending on the specific heating function. Furthermore, quasi-static solutions do not exist for an excessive concentration of heating near the loop footpoints, a result in agreement with recent numerical simulations. It is demonstrated that a generalization of the results to a set of solutions for strands with a functionally prescribed variable diameter leads to only relatively small correction factors in the scaling laws and temperature profiles for constant diameter loop strands. A quintet of leading theoretical coronal heating mechanisms is shown to be captured by the formalism of this paper, and the differences in thermal structure between them may be verified through observations. Preliminary results from full numerical simulations demonstrate that, despite the simplifying assumptions, the analytical solutions from this paper are accurate and stable.

Solar heating and cooling of buildings

Science.gov (United States)

Bourke, R. D.; Davis, E. S.

1975-01-01

Solar energy has been used for space heating and water heating for many years. A less common application, although technically feasible, is solar cooling. This paper describes the techniques employed in the heating and cooling of buildings, and in water heating. The potential for solar energy to displace conventional energy sources is discussed. Water heating for new apartments appears to have some features which could make it a place to begin the resurgence of solar energy applications in the United States. A project to investigate apartment solar water heating, currently in the pilot plant construction phase, is described.

Harnessing solar heat

CERN Document Server

Norton, Brian

2013-01-01

Systems engineered by man to harness solar heat in a controlled manner now include a diverse range of technologies each serving distinctive needs in particular climate contexts. This text covers the breadth of solar energy technologies for the conversion of solar energy to provide heat, either as the directly-used output or as an intermediary to other uses such as power generation or cooling. It is a wholly updated, extended and revised version of “Solar Energy Thermal Technology” first published in 1992. The text draws on the own author’s research and that of numerous colleagues and

Absorption technology for solar and waste heat utilization

International Nuclear Information System (INIS)

Grossman, G.

1993-01-01

Absorption heat pumps, first developed in the 19th century, have received renewed and growing attention in the past two decades. With the increasing cost of oil and electricity, the particular features of this heat-powered cycle have made it attractive for both residential and industrial applications. Solar-powered air conditioning, gas-fired domestic cooling and waste-heat-powered temperature boosters are some of the applications on which intensive research and development has been conducted. This paper describes the operation of absorption systems and discusses several practical applications. It surveys recent advances in absorption technology, including the selection of working fluids, cycle improvements and multi-staging, and fundamentals of the combined heat and mass transfer in absorption processes. (author)

Research programme 'Active Solar Energy Use - Solar Heating and Heat Storage'. Activities and projects 2003

International Nuclear Information System (INIS)

Hadorn, J.-C.; Renaud, P.

2003-01-01

In this report by the research, development and demonstration (RD+D) programme coordinators the objectives, activities and main results in the area of solar heating and heat storage in Switzerland are presented for 2003. In a stagnating market environment the strategy of the Swiss Federal Office of Energy mainly consists in improving the quality and durability of solar collectors and materials, optimizing combisystems for space heating and domestic hot water preparation, searching for storage systems with a higher energy storage density than in the case of sensible heat storage in water, developing coloured solar collectors for more architectonic freedom, and finalizing a seasonal heat storage project for 100 dwellings to demonstrate the feasibility of solar fractions larger than 50% in apartment houses. Support was granted to the Swiss Testing Facility SPF in Rapperswil as in previous years; SPF was the first European testing institute to perform solar collector labeling according to the new rules of the 'Solar Keymark', introduced in cooperation with the European Committee for Standardization CEN. Several 2003 projects were conducted within the framework of the Solar Heating and Cooling Programme of the International Energy Agency IEA. Computerized simulation tools were improved. With the aim of jointly producing high-temperature heat and electric power a solar installation including a concentrating collector and a thermodynamic machine based on a Rankine cycle is still being developed. Seasonal underground heat storage was studied in detail by means of a validated computer simulation programme. Design guidelines were obtained for such a storage used in the summer time for cooling and in the winter time for space heating via a heat pump: depending on the ratio 'summer cooling / winter heating', cooling requires a cooling machine, or direct cooling without such a machine is possible. The report ends up with the list of all supported RD+D projects

Analysis of Solar Energy Use for Multi-Flat Buildings Renovation

Directory of Open Access Journals (Sweden)

Kęstutis Valančius

2016-10-01

Full Text Available The paper analyses the energy and financial possibilities to install renewable energy sources (solar energy generating systems when renovating multi-flat buildings. The aim is to analyse solar energy system possibilities for modernization of multi-flat buildings (5-storey, 9-storey and 16-storey, providing detailed conclusions about the appropriateness of the energy systems and financial aspects. It is also intended to determine the optimal technological combinations and solutions to reach the maximum energy benefits. For the research computer simulation tools “EnergyPRO” and “PV*SOL Premium” are chosen. Also actual collected heat and electricity consumption data is used for the analysis.

EUV FLICKERING OF SOLAR CORONAL LOOPS: A NEW DIAGNOSTIC OF CORONAL HEATING

Energy Technology Data Exchange (ETDEWEB)

Tajfirouze, E.; Reale, F.; Peres, G. [Dipartimento di Fisica e Chimica, Università di Palermo, Piazza del Parlamento 1, I-90134 (Italy); Testa, P., E-mail: reale@astropa.unipa.it [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2016-02-01

A previous work of ours found the best agreement between EUV light curves observed in an active region core (with evidence of super-hot plasma) and those predicted from a model with a random combination of many pulse-heated strands with a power-law energy distribution. We extend that work by including spatially resolved strand modeling and by studying the evolution of emission along the loops in the EUV 94 Å and 335 Å channels of the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory. Using the best parameters of the previous work as the input of the present one, we find that the amplitude of the random fluctuations driven by the random heat pulses increases from the bottom to the top of the loop in the 94 Å channel and from the top to the bottom in the 335 Å channel. This prediction is confirmed by the observation of a set of aligned neighboring pixels along a bright arc of an active region core. Maps of pixel fluctuations may therefore provide easy diagnostics of nanoflaring regions.

Preliminary design package for solar heating and hot water system

Science.gov (United States)

1977-01-01

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

Experimental results of 2-propanol dehydrogenation with a falling-liquid film reactor for solar chemical heat pump; Solar chemical heat pump ni okeru ryuka ekimakushiki 2-propanol bunkai hanno jikken

Energy Technology Data Exchange (ETDEWEB)

Doi, T; Tanaka, T; Ando, Y; Takashima, T [Electrotechnical Laboratory, Tsukuba (Japan); Koike, M; Kamoshida, J [Shibaura Institute of Technology, Tokyo (Japan)

1997-11-25

A solar chemical heat pump is intended to attempt multi-purposed effective utilization of solar energy by raising low temperature solar heat of about 100 degC to 150 to 200 degC by utilizing chemical reactions. The chemical heat pump under the present study uses a 2-propanol (IPA)/acetone/hydrogen system which can utilize low-temperature solar heat and has large temperature rising degree. It was found from the result of experiments and analyses that IPA dehydrogenation reaction can improve more largely the heat utilization rate in using a falling-liquid film reactor than using a liquid phase suspended system. As an attempt to improve further the heat utilization rate, this paper reports the result of experimental discussions on inclination angles of a reaction vessel and feed liquid flow rate which would affect the fluid condition of the liquid film. As a result of the experiments, the initial deterioration in the catalyst has settled in about 15 hours, and its activity has decreased to about 60% of the initial activity. It was made clear that the influence of the inclination angle of the reaction vessel on the reaction is small. 5 refs., 7 figs.

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

Directory of Open Access Journals (Sweden)

Zhiyong Yang

2011-03-01

Full Text Available A solar assisted heat pump (SAHP system was designed by using a roof-integrated solar collector as the evaporator, and then it was demonstrated to provide space heating for a villa in Tianjin, China. A building energy simulation tool was used to predict the space heating load and a three dimensional theoretical model was established to analyze the heat collection performance of the solar roof collector. A floor radiant heating unit was used to decrease the energy demand. The measurement results during the winter test period show that the system can provide a comfortable living space in winter, when the room temperature averaged 18.9 °C. The average COP of the heat pump system is 2.97 and with a maximum around 4.16.

Fundamentals of Solar Heating. Correspondence Course.

Science.gov (United States)

Sheet Metal and Air Conditioning Contractors National Association, Vienna, VA.

This course is designed for the use of employees of the air conditioning industry, and offers supervised correspondence instruction about solar technology. The following aspects of applied solar technology are covered: solar heating and cooling, solar radiation, solar collectors, heat storage control devices and specialty items, sizing solar…

Solar-powered Rankine heat pump for heating and cooling

Science.gov (United States)

Rousseau, J.

1978-01-01

The design, operation and performance of a familyy of solar heating and cooling systems are discussed. The systems feature a reversible heat pump operating with R-11 as the working fluid and using a motor-driven centrifugal compressor. In the cooling mode, solar energy provides the heat source for a Rankine power loop. The system is operational with heat source temperatures ranging from 155 to 220 F; the estimated coefficient of performance is 0.7. In the heating mode, the vapor-cycle heat pump processes solar energy collected at low temperatures (40 to 80 F). The speed of the compressor can be adjusted so that the heat pump capacity matches the load, allowing a seasonal coefficient of performance of about 8 to be attained.

Design optimization of a multi-temperature solar thermal heating system for an industrial process

International Nuclear Information System (INIS)

Allouhi, A.; Agrouaz, Y.; Benzakour Amine, Mohammed; Rehman, S.; Buker, M.S.; Kousksou, T.; Jamil, A.; Benbassou, A.

2017-01-01

Highlights: •Integration of solar thermal energy into an industrial activity is presented. •Hot water is required at four temperatures and load profiles. •Design optimization based on the LCC method is introduced. •Annual performance of centralized system is discussed. •Sensitivity analysis based on economic variables is investigated. -- Abstract: Presently, great challenges are being faced by the industrial sector in terms of energy management and environmental protection. Utilization of solar energy to meet a portion of heat demand in various industries constitutes tremendous economic opportunities for developing countries such as Morocco. Therefore, this paper introduces an optimization procedure and simulation of a centralized solar heating system providing hot water to four processes with different temperature levels and load profiles. As a case study, a Casablanca based Moroccan milk processing company is evaluated and the life cycle cost method is practiced to select the optimal size of the main design parameters for decision-making. It was found that 400 m 2 of evacuated tube collectors tilted at an angle of 30° and connected to a 2000 l storage tank can lead to a maximum life cycle saving cost of 179 kUSD for a total annual heat demand of 528.23 MWh. In this optimal configuration, the overall annual solar fraction is found to be 41% and the payback period of 12.27 years attained. The system has the potential to reduce around 77.23 tons of CO 2 equivalents of greenhouse gas emissions annually. The economic competitiveness of the solar thermal heating plant can be considerably improved with higher inflation rates and lower initial investments.

Emerging large-scale solar heating applications

International Nuclear Information System (INIS)

Wong, W.P.; McClung, J.L.

2009-01-01

Currently the market for solar heating applications in Canada is dominated by outdoor swimming pool heating, make-up air pre-heating and domestic water heating in homes, commercial and institutional buildings. All of these involve relatively small systems, except for a few air pre-heating systems on very large buildings. Together these applications make up well over 90% of the solar thermal collectors installed in Canada during 2007. These three applications, along with the recent re-emergence of large-scale concentrated solar thermal for generating electricity, also dominate the world markets. This paper examines some emerging markets for large scale solar heating applications, with a focus on the Canadian climate and market. (author)

Emerging large-scale solar heating applications

Energy Technology Data Exchange (ETDEWEB)

Wong, W.P.; McClung, J.L. [Science Applications International Corporation (SAIC Canada), Ottawa, Ontario (Canada)

2009-07-01

Currently the market for solar heating applications in Canada is dominated by outdoor swimming pool heating, make-up air pre-heating and domestic water heating in homes, commercial and institutional buildings. All of these involve relatively small systems, except for a few air pre-heating systems on very large buildings. Together these applications make up well over 90% of the solar thermal collectors installed in Canada during 2007. These three applications, along with the recent re-emergence of large-scale concentrated solar thermal for generating electricity, also dominate the world markets. This paper examines some emerging markets for large scale solar heating applications, with a focus on the Canadian climate and market. (author)

Modeling active region transient brightenings observed with X-ray telescope as multi-stranded loops

Energy Technology Data Exchange (ETDEWEB)

Kobelski, Adam R.; McKenzie, David E. [Department of Physics, P.O. Box 173840, Montana State University, Bozeman, MT 59717-3840 (United States); Donachie, Martin, E-mail: kobelski@solar.physics.montana.edu [University of Glasgow, Glasgow, G128QQ, Scotland (United Kingdom)

2014-05-10

Strong evidence exists that coronal loops as observed in extreme ultraviolet and soft X-rays may not be monolithic isotropic structures, but can often be more accurately modeled as bundles of independent strands. Modeling the observed active region transient brightenings (ARTBs) within this framework allows for the exploration of the energetic ramifications and characteristics of these stratified structures. Here we present a simple method of detecting and modeling ARTBs observed with the Hinode X-Ray Telescope (XRT) as groups of zero-dimensional strands, which allows us to probe parameter space to better understand the spatial and temporal dependence of strand heating in impulsively heated loops. This partially automated method can be used to analyze a large number of observations to gain a statistical insight into the parameters of coronal structures, including the number of heating events required in a given model to fit the observations. In this article, we present the methodology and demonstrate its use in detecting and modeling ARTBs in a sample data set from Hinode/XRT. These initial results show that, in general, multiple heating events are necessary to reproduce observed ARTBs, but the spatial dependence of these heating events cannot yet be established.

Modeling active region transient brightenings observed with X-ray telescope as multi-stranded loops

International Nuclear Information System (INIS)

Kobelski, Adam R.; McKenzie, David E.; Donachie, Martin

2014-01-01

Strong evidence exists that coronal loops as observed in extreme ultraviolet and soft X-rays may not be monolithic isotropic structures, but can often be more accurately modeled as bundles of independent strands. Modeling the observed active region transient brightenings (ARTBs) within this framework allows for the exploration of the energetic ramifications and characteristics of these stratified structures. Here we present a simple method of detecting and modeling ARTBs observed with the Hinode X-Ray Telescope (XRT) as groups of zero-dimensional strands, which allows us to probe parameter space to better understand the spatial and temporal dependence of strand heating in impulsively heated loops. This partially automated method can be used to analyze a large number of observations to gain a statistical insight into the parameters of coronal structures, including the number of heating events required in a given model to fit the observations. In this article, we present the methodology and demonstrate its use in detecting and modeling ARTBs in a sample data set from Hinode/XRT. These initial results show that, in general, multiple heating events are necessary to reproduce observed ARTBs, but the spatial dependence of these heating events cannot yet be established.

Large Scale Solar Heating

DEFF Research Database (Denmark)

Heller, Alfred

2001-01-01

The main objective of the research was to evaluate large-scale solar heating connected to district heating (CSDHP), to build up a simulation tool and to demonstrate the application of the simulation tool for design studies and on a local energy planning case. The evaluation was mainly carried out...... model is designed and validated on the Marstal case. Applying the Danish Reference Year, a design tool is presented. The simulation tool is used for proposals for application of alternative designs, including high-performance solar collector types (trough solar collectors, vaccum pipe collectors......). Simulation programs are proposed as control supporting tool for daily operation and performance prediction of central solar heating plants. Finaly the CSHP technolgy is put into persepctive with respect to alternatives and a short discussion on the barries and breakthrough of the technology are given....

Solar heating - a major source of renewable energy

International Nuclear Information System (INIS)

Bosselaar, L.

2001-01-01

Actions that can be taken to increase the uptake of technology for solar water heaters and solar buildings are discussed. An overview of existing technology covers solar water heating, solar buildings, space heating, solar cooling, solar drying, solar desalination. Solar water heating, solar buildings and solar crop drying are discussed individually under the sub-headings of (a) the technology; (b) the market; (c) potential; (d) economics and (e) market acceleration strategies. Other subjects discussed are market acceleration, main opportunities, R and D needs and conclusions. The IEA solar heating and solar cooling programme is described

Experimental and numerical study on a new multi-effect solar still with enhanced condensation surface

International Nuclear Information System (INIS)

Xiong, Jianyin; Xie, Guo; Zheng, Hongfei

2013-01-01

Highlights: • A novel multi-effect solar still with enhanced condensation surface is designed. • The overall desalination efficiency and performance ratio can reach 0.91 and 1.86. • A numerical model characterizing the heat and mass transfer process is developed. - Abstract: A novel multi-effect solar desalination system with enhanced condensation surface is designed. Compared to traditional solar still, it has two main merits: (1) the application of corrugated shape stacked trays decreases the condensation resistance, thus improves the desalination performance and (2) the simultaneous heating both from the collector in the bottom and coating in the top efficiently uses the solar energy, which increases the freshwater yield. Field test is then carried out to study the temperature and freshwater yield characteristics. It is observed that the solar still can generate freshwater not only in the daytime but also in the night, with the latter taking up about 40% of the total freshwater yield. When the starting temperature is relatively high, the overall desalination efficiency and performance ratio of the equipment can reach 0.91 and 1.86, respectively. Furthermore, a numerical model characterizing the heat and mass transfer process in the solar still is developed. The good agreement between the model prediction and experimental data demonstrates the effectiveness of the proposed model. For the present solar still, a phenomenon of reverse temperature difference in the second stacked tray is emerged due to the special simultaneous heating pattern, which is also validated by the numerical model

Dimensioning of Solar Thermal Systems for Multi-Family Buildings in Lithuania: an Optimisation Study

OpenAIRE

Valančius, Rokas; Jurelionis, Andrius; Vaičiūnas, Juozas; Perednis, Eugenijus

2017-01-01

Small-scale solar thermal domestic hot water (DHW) systems in Lithuania can produce up to 523 kWh per year per one square meter of solar collector area. It is therefore one of the most common solar thermal applications in the country with the expected payback period of approximately 10 years. However, the number of solar water heating systems (SWH) installed in the renovated multi-family buildings is quite limited. On the other hand, the potential of integrating solar thermal systems in these...

Energy savings for solar heating systems; Solvarmeanlaegs energibesparelser

Energy Technology Data Exchange (ETDEWEB)

Furbo, S.; Fan, J.

2011-01-15

Energy savings for a number of new solar heating systems in one family houses have been determined by means of information on the energy consumption of the houses before and after installation of the solar heating systems. The investigated solar heating systems are marketed by Velux Danmark A/S, Sonnnenkraft Scandinavia A/S and Batec Solvarme A/S. Solar domestic hot water systems as well as solar combi systems are included in the investigations The houses have different auxiliary energy supply systems: Natural gas boilers, oil fired burners, electrical heating and district heating. Some of the houses have a second auxiliary energy supply system. The collector areas vary from 1.83 m{sup 2} to 9.28 m{sup 2}. Some of the solar heating systems are based on energy units with a new integrated natural gas boiler and a heat storage for the solar heating system. The existing energy systems in the houses are for most of the houses used as the auxiliary energy systems for the solar heating systems. The yearly energy savings for the houses where the only change is the installation of the solar heating system vary from 300 kWh per m{sup 2} solar collector to 1300 kWh per m{sup 2} solar collector. The average yearly energy savings is about 670 kWh per m{sup 2} solar collector for these solar heating systems. The energy savings per m{sup 2} solar collector are not influenced by the solar heating system type, the company marketing the system, the auxiliary energy supply system, the collector area, the collector tilt, the collector azimuth, the energy consumption of the house or the location of the house. The yearly energy savings for the houses with solar heating systems based on energy units including a new natural gas boiler vary from 790 kWh per m{sup 2} solar collector to 2090 kWh per m{sup 2} solar collector. The average yearly energy savings is about 1520 kWh per m{sup 2} solar collector for these solar heating systems. The energy savings per m{sup 2} solar collector for

Solar heating action plan; Solvarme handlingsplan

Energy Technology Data Exchange (ETDEWEB)

Nielsen, Jan Erik

2011-10-15

This solar action plan should be seen as a follow-up to the Danish Energy Agency's solar heating strategy from 2007, which showed great potential and opportunities for exploitation and use of solar heat in Denmark. In relation to the strategy from 2007, this action plan adjusted the distribution of solar heat from district heating plants and individual plants, but it is still the objective of this action plan to achieve the strategy's overall goal for 2030. With the implementation of the Action Plan in early 2012, it is estimated that in 2030 there will be about. 10 million m2 of solar collectors in operation, 8 million m2 for district heating and 2 million m2 for individual heating, equivalent to an installed capacity totaling 7 GW. The budget for actions in the Action Plan is about 80 million DKK annually over the next 5 years to initiate and ensure this development. (LN)

Technology Roadmaps: Solar Heating and Cooling

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-09-06

The solar heating and cooling (SHC) roadmap outlines a pathway for solar energy to supply almost one sixth (18 EJ) of the world's total energy use for both heating and cooling by 2050. This would save some 800 megatonnes of carbon dioxide (CO2) emissions per year; more than the total CO2 emissions in Germany in 2009. While solar heating and cooling today makes a modest contribution to world energy demand, the roadmap envisages that if concerted action is taken by governments and industry, solar energy could annually produce more than 16% of total final energy use for low temperature heat and nearly 17% for cooling. Given that global energy demand for heat represents almost half of the world's final energy use -- more than the combined global demand for electricity and transport -- solar heat can make a significant contribution in both tackling climate change and strengthening energy security.

Technology Roadmaps: Solar Heating and Cooling

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-07-01

The solar heating and cooling (SHC) roadmap outlines a pathway for solar energy to supply almost one sixth (18 EJ) of the world’s total energy use for both heating and cooling by 2050. This would save some 800 megatonnes of carbon dioxide (CO2) emissions per year; more than the total CO2 emissions in Germany in 2009. While solar heating and cooling today makes a modest contribution to world energy demand, the roadmap envisages that if concerted action is taken by governments and industry, solar energy could annually produce more than 16% of total final energy use for low temperature heat and nearly 17% for cooling. Given that global energy demand for heat represents almost half of the world’s final energy use – more than the combined global demand for electricity and transport – solar heat can make a significant contribution in both tackling climate change and strengthening energy security.

Chromospheric heating during flux emergence in the solar atmosphere

Science.gov (United States)

Leenaarts, Jorrit; de la Cruz Rodríguez, Jaime; Danilovic, Sanja; Scharmer, Göran; Carlsson, Mats

2018-04-01

Context. The radiative losses in the solar chromosphere vary from 4 kW m-2 in the quiet Sun, to 20 kW m-2 in active regions. The mechanisms that transport non-thermal energy to and deposit it in the chromosphere are still not understood. Aim. We aim to investigate the atmospheric structure and heating of the solar chromosphere in an emerging flux region. Methods: We have used observations taken with the CHROMIS and CRISP instruments on the Swedish 1-m Solar Telescope in the Ca II K , Ca II 854.2 nm, Hα, and Fe I 630.1 nm and 630.2 nm lines. We analysed the various line profiles and in addition perform multi-line, multi-species, non-local thermodynamic equilibrium (non-LTE) inversions to estimate the spatial and temporal variation of the chromospheric structure. Results: We investigate which spectral features of Ca II K contribute to the frequency-integrated Ca II K brightness, which we use as a tracer of chromospheric radiative losses. The majority of the radiative losses are not associated with localised high-Ca II K-brightness events, but instead with a more gentle, spatially extended, and persistent heating. The frequency-integrated Ca II K brightness correlates strongly with the total linear polarization in the Ca II 854.2 nm, while the Ca II K profile shapes indicate that the bulk of the radiative losses occur in the lower chromosphere. Non-LTE inversions indicate a transition from heating concentrated around photospheric magnetic elements below log τ500 = -3 to a more space-filling and time-persistent heating above log τ500 = -4. The inferred gas temperature at log τ500 = -3.8 correlates strongly with the total linear polarization in the Ca II 854.2 nm line, suggesting that that the heating rate correlates with the strength of the horizontal magnetic field in the low chromosphere. Movies attached to Figs. 1 and 4 are available at http://https://www.aanda.org/

TIME-RESOLVED EMISSION FROM BRIGHT HOT PIXELS OF AN ACTIVE REGION OBSERVED IN THE EUV BAND WITH SDO/AIA AND MULTI-STRANDED LOOP MODELING

Energy Technology Data Exchange (ETDEWEB)

Tajfirouze, E.; Reale, F.; Petralia, A. [Dipartimento di Fisica e Chimica, Università di Palermo, Piazza del Parlamento 1, I-90134 (Italy); Testa, P., E-mail: aastex-help@aas.org [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2016-01-01

Evidence of small amounts of very hot plasma has been found in active regions and might be an indication of impulsive heating released at spatial scales smaller than the cross-section of a single loop. We investigate the heating and substructure of coronal loops in the core of one such active region by analyzing the light curves in the smallest resolution elements of solar observations in two EUV channels (94 and 335 Å) from the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory. We model the evolution of a bundle of strands heated by a storm of nanoflares by means of a hydrodynamic 0D loop model (EBTEL). The light curves obtained from a random combination of those of single strands are compared to the observed light curves either in a single pixel or in a row of pixels, simultaneously in the two channels, and using two independent methods: an artificial intelligent system (Probabilistic Neural Network) and a simple cross-correlation technique. We explore the space of the parameters to constrain the distribution of the heat pulses, their duration, their spatial size, and, as a feedback on the data, their signatures on the light curves. From both methods the best agreement is obtained for a relatively large population of events (1000) with a short duration (less than 1 minute) and a relatively shallow distribution (power law with index 1.5) in a limited energy range (1.5 decades). The feedback on the data indicates that bumps in the light curves, especially in the 94 Å channel, are signatures of a heating excess that occurred a few minutes before.

MUSE, the Multi-Slit Solar Explorer

Science.gov (United States)

Lemen, J. R.; Tarbell, T. D.; De Pontieu, B.; Wuelser, J. P.

2017-12-01

The Multi-Slit Solar Explorer (MUSE) has been selected for a Phase A study for the NASA Heliophysics Small Explorer program. The science objective of MUSE is to make high spatial and temporal resolution imaging and spectral observations of the solar corona and transition region in order to probe the mechanisms responsible for energy release in the corona and understand the dynamics of the solar atmosphere. The physical processes are responsible for heating the corona, accelerating the solar wind, and the rapid release of energy in CMEs and flares. The observations will be tightly coupled to state-of-the-art numerical modeling to provide significantly improved estimates for understanding and anticipating space weather. MUSE contains two instruments: an EUV spectrograph and an EUV context imager. Both have similar spatial resolutions and leverage extensive heritage from previous high-resolution instruments such as IRIS and the HiC rocket payload. The MUSE spectrograph employs a novel multi-slit design that enables a 100x improvement in spectral scanning rates, which will reveal crucial information about the dynamics (e.g., temperature, velocities) of the physical processes that are not observable with current instruments. The MUSE investigation builds on the success of IRIS by combining numerical modeling with a uniquely capable observatory: MUSE will obtain EUV spectra and images with the highest resolution in space (1/3 arcsec) and time (1-4 s) ever achieved for the transition region and corona, along 35 slits and a large context FOV simultaneously. The MUSE consortium includes LMSAL, SAO, Stanford, ARC, HAO, GSFC, MSFC, MSU, and ITA Oslo.

Solar Air Heaters with Thermal Heat Storages

OpenAIRE

Saxena, Abhishek; Goel, Varun

2013-01-01

Solar energy can be converted into different forms of energy, either to thermal energy or to electrical energy. Solar energy is converted directly into electrical power by photovoltaic modules, while solar collector converts solar energy into thermal energy. Solar collector works by absorbing the direct solar radiation and converting it into thermal energy, which can be stored in the form of sensible heat or latent heat or a combination of sensible and latent heats. A theoretical study has be...

Solar heating pipe

Energy Technology Data Exchange (ETDEWEB)

Hinson-Rider, G.

1977-10-04

A fluid carrying pipe is described having an integral transparent portion formed into a longitudinally extending cylindrical lens that focuses solar heat rays to a focal axis within the volume of the pipe. The pipe on the side opposite the lens has a heat ray absorbent coating for absorbing heat from light rays that pass through the focal axis.

Effect of incentives on the financial attractiveness of solar industrial process heating in India★

Directory of Open Access Journals (Sweden)

Sharma Ashish K.

2017-01-01

Full Text Available India has a huge industrial demand for process heating at temperatures that can be provided with commercially available solar collectors. Government of India with support from multi-lateral agencies has initiated an ambitious programme for promoting large scale adoption of Solar Industrial Process Heating (SIPH in the industrial sector of the country. This paper presents the details of an attempt to study the effect of several existing and potential incentives on the financial attractiveness of SIPH systems in India. A case of solar process heating in dairy industry has been presented to demonstrate the relative efficacy of different incentives on the economics of SIPH systems in terms of their impact on levelized cost of useful thermal energy delivered. Finally, policy implications of the results obtained have been discussed.

The turbulent cascade and proton heating in the solar wind during solar minimum

International Nuclear Information System (INIS)

Coburn, Jesse T.; Smith, Charles W.; Vasquez, Bernard J.; Stawarz, Joshua E.; Forman, Miriam A.

2013-01-01

Solar wind measurements at 1 AU during the recent solar minimum and previous studies of solar maximum provide an opportunity to study the effects of the changing solar cycle on in situ heating. Our interest is to compare the levels of activity associated with turbulence and proton heating. Large-scale shears in the flow caused by transient activity are a source that drives turbulence that heats the solar wind, but as the solar cycle progresses the dynamics that drive the turbulence and heat the medium are likely to change. The application of third-moment theory to Advanced Composition Explorer (ACE) data gives the turbulent energy cascade rate which is not seen to vary with the solar cycle. Likewise, an empirical heating rate shows no significan changes in proton heating over the cycle.

Heat Treatment Optimization Studies on PIT Nb$_3$Sn Strand for the NED Project

CERN Document Server

Boutboul, T; den Ouden, A; Pedrini, D; Seeber, B; Volpini, G

2009-01-01

For the Next European Dipole (NED) program, a Powder-In-Tube (PIT) strand was successfully developed by SMI. This high-performance Nb$_{3}$Sn strand presents a non-copper critical current density of ~ 2500 A/mm2 at 12 T applied field and 4.2 K and a filament diameter around 50 µm. Extensive heat treatment optimization studies were performed in order to maximize both critical current and RRR, with a plateau temperature down to 625 oC and duration up to 400 hours. It appears that a critical current enhancement of ~ 10 % can be achieved for a reaction schedule of 320 hours at 625 oC with non-copper critical current density respectively exceeding 2700 and 1500 A/mm2 at 12 and 15 T (4.2 K). Thanks to this modified heat treatment, this strand completely fulfils the NED stringent specification.

Solar district heating and cooling: A review

DEFF Research Database (Denmark)

Perez-Mora, Nicolas; Bava, Federico; Andersen, Martin

2018-01-01

and decentralized solar district heating as well as block heating. For the different technologies, the paper describes commonly adopted control strategies, system configurations, types of installation, and integration. Real‐world examples are also given to provide a more detailed insight into how solar thermal...... technology can be integrated with district heating. Solar thermal technology combined with thermally driven chillers to provide cooling for cooling networks is also included in this paper. In order for a technology to spread successfully, not only technical but also economic issues need to be tackled. Hence......Both district heating and solar collector systems have been known and implemented for many years. However, the combination of the two, with solar collectors supplying heat to the district heating network, is relatively new, and no comprehensive review of scientific publications on this topic could...

Multi-annual planning of investments for heat production. 2009 - 2020 period

International Nuclear Information System (INIS)

2005-01-01

A new Multi-annual Planning of Investments (PPI) for heat production in France has been realized in order to meet the conclusions of the Grenelle Environnement Forum for a better energy efficiency and a larger use of renewable energies. Based on quantitative data (the increase in heat production will reach more than 10 Mtoe by 2020), potential objectives have been assessed for the various heat production sources and techniques: wood, biomass (for buildings, district heating, industry and processes, cogeneration), deep and intermediary geothermal energy, individual heat pumps, individual and collective heat solar systems, biogas, etc. These objectives are said to be ambitious but reachable if every sources and techniques are thoroughly exploited

Solar Heating Systems with Evacuated Tubular Solar Collector

DEFF Research Database (Denmark)

Qin, Lin; Furbo, Simon

1998-01-01

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

EFFICIENCY AND LIFETIME OF SOLAR COLLECTORS FOR SOLAR HEATING PLANTS

DEFF Research Database (Denmark)

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

EFFICIENCY AND LIFETIME OF SOLAR COLLECTORS FOR SOLAR HEATING PLANTS

DEFF Research Database (Denmark)

Fan, Jianhua; Chen, Ziqian; Furbo, Simon

2009-01-01

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

The study of the heat-engineering characteristics of a solar heat collector based on aluminum heat pipes

International Nuclear Information System (INIS)

Khairnasov, S.M.; Zaripov, V.K.; Passamakin, B.M. et al.

2013-01-01

This paper presents the results of studies into the heat-engineering characteristics of a flat heat solar collector based on aluminum heat pipes that is designed to be used in building facades. The principle of work and the structure of the solar collector are considered; the results of its comparison with a traditional flat solar collector are presented. The studies were performed at a heat carrier temperature range of +10 - +30 degree C and at a solar heat flow density of 400 - 1000 W/m 2 . The obtained experimental heat-engineering characteristics of the collector based on heat pipes show that they are at a level of traditional flow solar collectors; for example, its efficiency is 0.65 - 0.73. Meanwhile, the hydraulic resistance of the structure with heat pipes is by a factor of 2 - 2.4 smaller and ensures a high level of scalability, reliability, and maintainability, which is important when using it as an element of facade constructions of solar heat systems. (author)

Solar heat-pipe wick modeling

Energy Technology Data Exchange (ETDEWEB)

Andraka, C.E.

1999-07-01

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

MINERGIE modules: heat pump - heat pump/solar - wood - wood/solar; Minergie-Module Waermepumpe - Waermepumpe/Solar - Holz - Holz/Solar

Energy Technology Data Exchange (ETDEWEB)

Gallati, J. [Seecon GmbH, Lucerne (Switzerland); Portmann, M. [Buero Markus Portmann, Kriens (Switzerland); Zurfluh, B. [Zurfluh Lottenbach, Lucerne (Switzerland)

2005-07-01

This research report for the Swiss Federal Office of Energy (SFOE) presents the results of a project that examined the feasibility of setting up 'MINERGIE' low-energy-consumption module standards for the production of heat in small residential buildings. The aims of the standards and the basic idea behind the MINERGIE-modules are discussed. The concepts of the modules for heat pumps and wood-fired heating systems and their combination with solar installations are examined, as are their areas of application. The requirements placed on the modules are listed. System concepts, including simple schematics for typical installations, are presented for wood-log, wood-chippings and pellets-fired systems as well as for ground-loop and air-water heat pump systems as well as their solar-aided counterparts. The results of cost-benefit analyses are presented and questions regarding system guarantee and liability are examined.

Closed loop solar chemical heat pipe

International Nuclear Information System (INIS)

Levy, M.; Levitan, R.; Rosin, H.; Rubin, R.

1991-01-01

The system used for the closed loop operation of the solar chemical heat pipe comprises a reformer, heated by the solar furnace, a methanator and a storage assembly containing a compressor and storage cylinders. (authors). 7 figs

Solar-assisted heat pump system for cost-effective space heating and cooling

Energy Technology Data Exchange (ETDEWEB)

Andrews, J W; Kush, E A; Metz, P D

1978-03-01

The use of heat pumps for the utilization of solar energy is studied. Two requirements for a cost-effective system are identified: (1) a special heat pump whose coefficient of performance continues to rise with source temperature over the entire range appropriate for solar assist, and (2) a low-cost collection and storage subsystem able to supply solar energy to the heat pump efficiently at low temperatures. Programs leading to the development of these components are discussed. A solar assisted heat pump system using these components is simulated via a computer, and the results of the simulation are used as the basis for a cost comparison of the proposed system with other solar and conventional systems.

Solar heating and employment in Canada

Energy Technology Data Exchange (ETDEWEB)

Victor, P A

1978-01-01

If solar heating technology is to be introduced into sections of Canada as a way to alleviate unemployment problems and stimulate the manufacturing sector, realistic expectations must be grounded in better estimates of solar energy's potential than were made by early nuclear power enthusiasts. A study by Middleton Associates identified a number of factors affecting employment. These include implementation rates, choice of technologies, industry size, government involvement, location, and the share of solar heating relative to other heating sources. An employment simulation model using available technologies as inputs suggests that solar heating is feasible on the basis of both energy source and employment strategy. Model results are favorable for direct and indirect employment, while displacement effects on employment in conventional fuel industries are minor. Direct employment is affected more by implementation rates than by variations in the amount of imported equipment.

Thermal performance of solar district heating plants in Denmark

DEFF Research Database (Denmark)

Furbo, Simon; Perers, Bengt; Bava, Federico

2014-01-01

The market for solar heating plants connected to district heating systems is expanding rapidly in Denmark. It is expected that by the end of 2014 the 10 largest solar heating plants in Europe will be located in Denmark. Measurements from 23 Danish solar heating plants, all based on flat plate solar...... collectors mounted on the ground, shows measured yearly thermal performances of the solar heating plants placed in the interval from 313 kWh/m² collector to 493 kWh/m² collector with averages for all plants of 411 kWh/m² collector for 2012 and 450 kWh/m² collector for 2013. Theoretical calculations show...... of the cost/performance ratio for solar collector fields, both with flat plate collectors and with concentrating tracking solar collectors. It is recommended to continue monitoring and analysis of all large solar heating plants to document the reliability of the solar heating plants. It is also recommended...

Residential solar-heating system

Science.gov (United States)

1978-01-01

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

New Insight into Combined Model and Revised Model for RTD Curves in a Multi-strand Tundish

Science.gov (United States)

Lei, Hong

2015-12-01

The analysis for the residence time distribution (RTD) curve is one of the important experimental technologies to optimize the tundish design. But there are some issues about RTD analysis model. Firstly, the combined (or mixed) model and the revised model give different analysis results for the same RTD curve. Secondly, different upper limits of integral in the numerator for the mean residence time give different results for the same RTD curve. Thirdly, the negative dead volume fraction sometimes appears at the outer strand of the multi-strand tundish. In order to solve the above problems, it is necessary to have a deep insight into the RTD curve and to propose a reasonable method to analyze the RTD curve. The results show that (1) the revised model is not appropriate to treat with the RTD curve; (2) the conception of the visual single-strand tundish and the combined model with the dimensionless time at the cut-off point are applied to estimate the flow characteristics in the multi-strand tundish; and that (3) the mean residence time at each exit is the key parameter to estimate the similarity of fluid flow among strands.

Characterizing a Model of Coronal Heating and Solar Wind Acceleration Based on Wave Turbulence.

Science.gov (United States)

Downs, C.; Lionello, R.; Mikic, Z.; Linker, J.; Velli, M.

2014-12-01

Understanding the nature of coronal heating and solar wind acceleration is a key goal in solar and heliospheric research. While there have been many theoretical advances in both topics, including suggestions that they may be intimately related, the inherent scale coupling and complexity of these phenomena limits our ability to construct models that test them on a fundamental level for realistic solar conditions. At the same time, there is an ever increasing impetus to improve our spaceweather models, and incorporating treatments for these processes that capture their basic features while remaining tractable is an important goal. With this in mind, I will give an overview of our exploration of a wave-turbulence driven (WTD) model for coronal heating and solar wind acceleration based on low-frequency Alfvénic turbulence. Here we attempt to bridge the gap between theory and practical modeling by exploring this model in 1D HD and multi-dimensional MHD contexts. The key questions that we explore are: What properties must the model possess to be a viable model for coronal heating? What is the influence of the magnetic field topology (open, closed, rapidly expanding)? And can we simultaneously capture coronal heating and solar wind acceleration with such a quasi-steady formulation? Our initial results suggest that a WTD based formulation performs adequately for a variety of solar and heliospheric conditions, while significantly reducing the number of free parameters when compared to empirical heating and solar wind models. The challenges, applications, and future prospects of this type of approach will also be discussed.

Study of an active wall solar heating system

International Nuclear Information System (INIS)

Kassem, Talal

2006-01-01

An active wall solar heating system was built and tested. In the same time a compatible computer program has been according to set the recommended dimensions for the solar collectors where (F-Chart) method used to set the ratio of monthly solar sharing average for the examined heating system. Some parameters, such as collectors' areas, its tilt angle and near earth reflecting were experimentally investigated, affecting the executed active solar heating system performance. The study explain the ability of using this system which is simple, Low coast and high performance in heating residential and public buildings and heating water with ratio of yearly solar sharing achieves the needed saving of using this system.(Author)

Optimal Control of Solar Heating System

KAUST Repository

Huang, Bin-Juine

2017-02-21

Forced-circulation solar heating system has been widely used in process and domestic heating applications. Additional pumping power is required to circulate the water through the collectors to absorb the solar energy. The present study intends to develop a maximum-power point tracking control (MPPT) to obtain the minimum pumping power consumption at an optimal heat collection. The net heat energy gain Qnet (= Qs − Wp/ηe) was found to be the cost function for MPPT. The step-up-step-down controller was used in the feedback design of MPPT. The field test results show that the pumping power is 89 W at Qs = 13.7 kW and IT = 892 W/m2. A very high electrical COP of the solar heating system (Qs/Wp = 153.8) is obtained.

UNRAVELLING THE COMPONENTS OF A MULTI-THERMAL CORONAL LOOP USING MAGNETOHYDRODYNAMIC SEISMOLOGY

Energy Technology Data Exchange (ETDEWEB)

Prasad, S. Krishna; Jess, D. B. [Astrophysics Research Centre, School of Mathematics and Physics, Queen’s University Belfast, Belfast, BT7 1NN (United Kingdom); Klimchuk, J. A. [Heliophysics Division, NASA Goddard Space Flight Center, Greenbelt, MD, 20771 (United States); Banerjee, D., E-mail: krishna.prasad@qub.ac.uk [Indian Institute of Astrophysics, II Block Koramangala, Bengaluru 560034 (India)

2017-01-10

Coronal loops, constituting the basic building blocks of the active Sun, serve as primary targets to help understand the mechanisms responsible for maintaining multi-million Kelvin temperatures in the solar and stellar coronae. Despite significant advances in observations and theory, our knowledge on the fundamental properties of these structures is limited. Here, we present unprecedented observations of accelerating slow magnetoacoustic waves along a coronal loop that show differential propagation speeds in two distinct temperature channels, revealing the multi-stranded and multithermal nature of the loop. Utilizing the observed speeds and employing nonlinear force-free magnetic field extrapolations, we derive the actual temperature variation along the loop in both channels, and thus are able to resolve two individual components of the multithermal loop for the first time. The obtained positive temperature gradients indicate uniform heating along the loop, rather than isolated footpoint heating.

Experimental studies on a ground coupled heat pump with solar thermal collectors for space heating

International Nuclear Information System (INIS)

Xi, Chen; Hongxing, Yang; Lin, Lu; Jinggang, Wang; Wei, Liu

2011-01-01

This paper presents experimental studies on a solar-assisted ground coupled heat pump (SAGCHP) system for space heating. The system was installed at the Hebei Academy of Sciences in Shijiazhuang (lat. N38 o 03', long. E114 o 26'), China. Solar collectors are in series connection with the borehole array through plate heat exchangers. Four operation modes of the system were investigated throughout the coldest period in winter (Dec 5th to Dec 27th). The heat pump performance, borehole temperature distributions and solar colleting characteristics of the SAGCHP system are analyzed and compared when the system worked in continuous or intermittent modes with or without solar-assisted heating. The SAGCHP system is proved to perform space heating with high energy efficiency and satisfactory solar fraction, which is a promising substitute for the conventional heating systems. It is also recommended to use the collected solar thermal energy as an alternative source for the heat pump instead of recharging boreholes for heat storage because of the enormous heat capacity of the earth. -- Highlights: → We study four working modes of a solar-assisted ground coupled heat pump. → The heating performance is in direct relation with the borehole temperature. → Solar-assisted heating elevates borehole temperature and system performance. → The system shows higher efficiency over traditional heating systems in cold areas. → Solar heat is not suggested for high temperature seasonal storage.

Heat Pumps With Direct Expansion Solar Collectors

Science.gov (United States)

Ito, Sadasuke

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

Hybrid Model of Inhomogeneous Solar Wind Plasma Heating by Alfven Wave Spectrum: Parametric Studies

Science.gov (United States)

Ofman, L.

2010-01-01

Observations of the solar wind plasma at 0.3 AU and beyond show that a turbulent spectrum of magnetic fluctuations is present. Remote sensing observations of the corona indicate that heavy ions are hotter than protons and their temperature is anisotropic (T(sub perpindicular / T(sub parallel) >> 1). We study the heating and the acceleration of multi-ion plasma in the solar wind by a turbulent spectrum of Alfvenic fluctuations using a 2-D hybrid numerical model. In the hybrid model the protons and heavy ions are treated kinetically as particles, while the electrons are included as neutralizing background fluid. This is the first two-dimensional hybrid parametric study of the solar wind plasma that includes an input turbulent wave spectrum guided by observation with inhomogeneous background density. We also investigate the effects of He++ ion beams in the inhomogeneous background plasma density on the heating of the solar wind plasma. The 2-D hybrid model treats parallel and oblique waves, together with cross-field inhomogeneity, self-consistently. We investigate the parametric dependence of the perpendicular heating, and the temperature anisotropy in the H+-He++ solar wind plasma. It was found that the scaling of the magnetic fluctuations power spectrum steepens in the higher-density regions, and the heating is channeled to these regions from the surrounding lower-density plasma due to wave refraction. The model parameters are applicable to the expected solar wind conditions at about 10 solar radii.

Combined heat and power and solar energy; BHKW und solare Energie

Energy Technology Data Exchange (ETDEWEB)

Marchesi, M.; Schmidt, A.

2006-07-01

This illustrated article takes a look at a new apartment complex in Buelach, Switzerland, that meets the 'Minergie' low energy-consumption standard and also features solar-thermal heat generation. This solar installation provides heat for the provision of domestic hot water and, also, heat for the space-heating system of the building complex. The solar collectors cover an area of 153 m{sup 2}; their power is rated at 96 kW. Further elements of the building's technical services include a combined heat and power plant, a heat-pump and a gas-fired boiler. The article discusses ecological and social aspects of the design and construction of the building complex and briefly describes the installations, which also include a 'Minergie' fan-assisted balanced ventilation system.

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.

Simulation of embedded heat exchangers of solar aided ground source heat pump system

Institute of Scientific and Technical Information of China (English)

王芳; 郑茂余; 邵俊鹏; 李忠建

2008-01-01

Aimed at unbalance of soil temperature field of ground source heat pump system, solar aided energy storage system was established. In solar assisted ground-source heat pump (SAGSHP) system with soil storage, solar energy collected in three seasons was stored in the soil by vertical U type soil exchangers. The heat abstracted by the ground-source heat pump and collected by the solar collector was employed to heating. Some of the soil heat exchangers were used to store solar energy in the soil so as to be used in next winter after this heating period; and the others were used to extract cooling energy directly in the soil by circulation pump for air conditioning in summer. After that solar energy began to be stored in the soil and ended before heating period. Three dimensional dynamic numerical simulations were built for soil and soil heat exchanger through finite element method. Simulation was done in different strata month by month. Variation and restoration of soil temperature were studied. Economy and reliability of long term SAGSHP system were revealed. It can be seen that soil temperature is about 3 ℃ higher than the original one after one year’s running. It is beneficial for the system to operate for long period.

Competitive solar heating systems for residential buildings

DEFF Research Database (Denmark)

Furbo, Simon; Thür, Alexander; Fiedler, Frank

2005-01-01

The paper describes the ongoing research project “Competitive solar heating systems for residential buildings”. The aim of the project is to develop competitive solar combisystems which are attractive to buyers. The solar combisystems must be attractive compared to traditional energy systems, both....... In Denmark and Norway the focus is on solar heating/natural gas systems, and in Sweden and Latvia the focus is on solar heating/pellet systems. Additionally, Lund Institute of Technology and University of Oslo are studying solar collectors of various types being integrated into the roof and facade......, are the universities: Technical University of Denmark, Dalarna University, University of Oslo, Riga Technical University and Lund Institute of Technology, as well as the companies: Metro Therm A/S (Denmark), Velux A/S (Denmark), Solentek AB (Sweden) and SolarNor (Norway). The project consists of a number of Ph...

Assessment of solar-assisted gas-fired heat pump systems

Science.gov (United States)

Lansing, F. L.

1981-01-01

As a possible application for the Goldstone Energy Project, the performance of a 10 ton heat pump unit using a hybrid solar gas energy source was evaluated in an effort to optimize the solar collector size. The heat pump system is designed to provide all the cooling and/or heating requirements of a selected office building. The system performance is to be augmented in the heating mode by utilizing the waste heat from the power cycle. A simplified system analysis is described to assess and compute interrrelationships of the engine, heat pump, and solar and building performance parameters, and to optimize the solar concentrator/building area ratio for a minimum total system cost. In addition, four alternative heating cooling systems, commonly used for building comfort, are described; their costs are compared, and are found to be less competitive with the gas solar heat pump system at the projected solar equipment costs.

A heat pipe solar collector system for winter heating in Zhengzhou city, China

Directory of Open Access Journals (Sweden)

Zheng Hui-Fan

2017-01-01

Full Text Available A heat pipe solar collector system for winter heating is investigated both experimentally and theoretically. The hourly heat collecting capacity, water temperature and contribution rate of solar collector system based on Zhengzhou city typical sunshine are calculated. The study reveals that the heat collecting capacity and water temperature increases initially and then decreases, and the solar collector system can provide from 40% to 78% heating load for a 200 m2 villa with in Zhengzhou city from November to March.

High performance passive solar heating system with heat pipe energy transfer and latent heat storage

NARCIS (Netherlands)

Dijk, van H.A.L.; Galen, van E; Hensen, J.L.M.; Wit, de M.H.

1983-01-01

Preliminar results are reported from a current project on the development of a high performance passive solar heating system. Two special components are introduced: a. A heat pipe as a thermal diode tube for the efficient transfer of collected solar heat from the absorber plate to behind an

Basics of Solar Heating & Hot Water Systems.

Science.gov (United States)

American Inst. of Architects, Washington, DC.

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

Renewable-based heat supply of multi-apartment buildings with varied heat demands

International Nuclear Information System (INIS)

Truong, Nguyen Le; Dodoo, Ambrose; Gustavsson, Leif

2015-01-01

This study investigates the cost and primary energy use to heat an existing multi-apartment building in Sweden, before and after deep energy efficiency renovation, with different types of renewable-based systems. District heating systems of different scales as well as local heat production based on bioelectric boilers, ground-source bioelectric heat pumps and wood pellet boilers with or without solar heating are considered. The annual energy demand of the building, calculated hour by hour, with and without energy efficiency improvements, are matched against the renewable-based heat supply options by techno-economic modeling to minimize cost for each considered heat supply option. The results show that the availability of heating technologies at the building site and the scale of the building's heat demand influence the cost and the primary energy efficiency of the heating options. District heat from large-scale systems is cost efficient for the building without energy-efficiency improvement, whereas electric heat pumps and wood pellet boilers are more cost efficient when implementing energy-efficiency improvement. However, the cost difference is small between these alternatives and sensitive to the size of building. Large-scale district heating with cogeneration of power is most primary energy efficient while heat pumps and medium-scale district heating are nearly as efficient. - Highlights: • Heating technologies influence costs and primary energy use of a building. • Large-scale district heating with cogeneration of power is primary energy efficient. • Large-scale district heating is cost efficient for buildings with large heat demand. • Heat pumps and pellet boilers are cost competitive in energy-efficient buildings.

The Effect of the Heat Flux on the Self-Ignition of Oriented Strand Board

Science.gov (United States)

Hirle, Siegfried; Balog, Karol

2017-06-01

This article deals with the initiation phase of flaming and smouldering burning of oriented strand board. The influence of heat flux on thermal degradation of OSB boards, time to ignition, heat release rate and mass loss rate using thermal analysis and vertical electrical radiation panel methods were studied. Significant information on the influence of the heat flux density and the thickness of the material on time to ignition was obtained.

Numerical simulation of solar-assisted multi-effect distillation (SMED) desalination systems

KAUST Repository

Kim, Youngdeuk

2013-01-01

We present a simulation model for the transient behavior of solar-assisted seawater desalination plant that employs the evacuated-tube collectors in conjunction with a multieffect distillation plant of nominal water production capacity of 16m3/day. This configuration has been selected due to merits in terms of environment-friendliness and energy efficiency. The solar-assisted multi-effect distillation system comprises 849 m2 of evacuated-tube collectors, 280 m3 water storage tanks, auxiliary heater, and six effects and a condenser. The present analysis employs a baseline configuration, namely; (i) the local solar insolation input (Jeddah, Saudi Arabia), (ii) a coolant flow rate through the headers of collector based on ASHRAE standards, (iii) a heating water demand, and (iv) the augmentation of water temperature by auxiliary when the supply temperature from the solar tank drops below the set point. It is observed that the annual collector efficiency and solar fraction decrease from 57.3 to 54.8% and from 49.4 to 36.7%, respectively, with an increase in the heating water temperature from 80 to 90 °C. The overall water production rate and the performance ratio increase slightly from 0.18 to 0.21 kg/s and from 4.11 to 4.13, respectively. © 2013 Desalination Publications.

Optimal sizing of a multi-source energy plant for power heat and cooling generation

International Nuclear Information System (INIS)

Barbieri, E.S.; Dai, Y.J.; Morini, M.; Pinelli, M.; Spina, P.R.; Sun, P.; Wang, R.Z.

2014-01-01

Multi-source systems for the fulfilment of electric, thermal and cooling demand of a building can be based on different technologies (e.g. solar photovoltaic, solar heating, cogeneration, heat pump, absorption chiller) which use renewable, partially renewable and fossil energy sources. Therefore, one of the main issues of these kinds of multi-source systems is to find the appropriate size of each technology. Moreover, building energy demands depend on the climate in which the building is located and on the characteristics of the building envelope, which also influence the optimal sizing. This paper presents an analysis of the effect of different climatic scenarios on the multi-source energy plant sizing. For this purpose a model has been developed and has been implemented in the Matlab ® environment. The model takes into consideration the load profiles for electricity, heating and cooling for a whole year. The performance of the energy systems are modelled through a systemic approach. The optimal sizing of the different technologies composing the multi-source energy plant is investigated by using a genetic algorithm, with the goal of minimizing the primary energy consumption only, since the cost of technologies and, in particular, the actual tariff and incentive scenarios depend on the specific country. Moreover economic considerations may lead to inadequate solutions in terms of primary energy consumption. As a case study, the Sino-Italian Green Energy Laboratory of the Shanghai Jiao Tong University has been hypothetically located in five cities in different climatic zones. The load profiles are calculated by means of a TRNSYS ® model. Results show that the optimal load allocation and component sizing are strictly related to climatic data (e.g. external air temperature and solar radiation)

Performance of a Solar Heating System with Photovoltaic Thermal Hybrid Collectors and Heat Pump

DEFF Research Database (Denmark)

Dannemand, Mark; Furbo, Simon; Perers, Bengt

2017-01-01

. When the solar collectors are unable to supply the heat demand an auxiliary heat source is used. Heat pumps can generate this heat. Liquid/water heat pumps have better performance than air/water heat pumps in cold climates but requires installation of a tubing system for the cold side of the heat pump....... The tubes are typically placed in the ground, requires a significant land area and increase the installation cost. A new system design of a solar heating system with two storage tanks and a liquid/water heat pump is presented. The system consists of PVT collectors that generate both heat and electricity......The energy consumption in buildings accounts for a large part of the World’s CO2 emissions. Much energy is used for appliances, domestic hot water preparation and space heating. In solar heating systems, heat is captured by solar collectors when the sun is shining and used for heating purposes...

Novel and conventional working fluid mixtures for solar Rankine cycles: Performance assessment and multi-criteria selection

International Nuclear Information System (INIS)

Mavrou, Paschalia; Papadopoulos, Athanasios I.; Stijepovic, Mirko Z.; Seferlis, Panos; Linke, Patrick; Voutetakis, Spyros

2015-01-01

This work investigates the performance of working fluid mixtures for use in solar ORC (Organic Rankine Cycle systems) with heat storage employing FPC (Flat Plate Collectors). Several mixtures are considered including conventional choices often utilized in ORC as well as novel mixtures previously designed using advanced computer aided molecular design methods (Papadopoulos et al., 2013). The impact of heat source variability on the ORC performance is assessed for different working fluid mixtures. Solar radiation is represented in detail through actual, hourly averaged data for an entire year. A multi-criteria mixture selection methodology unveils important trade-offs among several important system operating parameters and efficiently highlights optimum operating ranges. Such parameters include the ORC thermal efficiency, the net generated power, the volume ratio across the turbine, the mass flow rate of the ORC working fluid, the evaporator temperature glide, the temperature drop in the storage tank, the ORC total yearly operating duration, the required collector aperture area to generate 1 kW of power and the irreversibility. A mixture of neopentane – 2-fluoromethoxy-2-methylpropane at 70% neopentane is found to be the most efficient in all the considered criteria simultaneously. - Highlights: • Investigation of novel and conventional working fluid mixtures for solar ORCs. • Systematic, multi-criteria assessment methodology for mixture selection. • Simultaneous consideration of multiple important mixture performance criteria. • Effects of year-round solar variability in a solar ORC with heat storage tank

Alterations in the nuclear matrix protein mass correlate with heat-induced inhibition of DNA single-strand-break repair

International Nuclear Information System (INIS)

Warters, R.L.; Brizgys, L.M.; Lyons, B.W.

1987-01-01

The total protein mass co-isolating with the nuclear matrix or nucleoid from Chinese hamster ovary (CHO) cells was observed to increase in heated cells as a function of increasing exposure temperature between 43 0 C and 45 0 C or of exposure time at any temperature. The sedimentation distance of the CHO cell nucleoid in sucrose gradients increased with increasing exposure time at 45 0 C. Both these nuclear alterations correlated in a log-linear manner with heat-induced inhibition of DNA strand break repair. A two-fold threshold increase in nuclear matrix protein mass preceded any substantial inhibition of repair of DNA single-strand breaks. When preheated cells were incubated at 37 0 C the nuclear matrix protein mass and nucleoid sedimentation recovered with a half-time of about 5 h, while DNA single-strand-break repair recovered with a half-time of about 2 h. When preheated cells were placed at 41 0 C a further increase was observed in the nuclear matrix protein mass and the half-time of DNA strand break repair, while nucleoid sedimentation recovered toward control values. These results implicate alterations in the protein mass of the nuclear matrix in heat-induced inhibition of repair of DNA single-strand breaks. (author)

Performance analysis on solar-water compound source heat pump for radiant floor heating system

Institute of Scientific and Technical Information of China (English)

曲世林; 马飞; 仇安兵

2009-01-01

A solar-water compound source heat pump for radiant floor heating (SWHP-RFH) experimental system was introduced and analyzed. The SWHP-RFH system mainly consists of 11.44 m2 vacuum tube solar collector,1 000 L water tank assisted 3 kW electrical heater,a water source heat pump,the radiant floor heating system with cross-linked polyethylene (PE-X) of diameter 20 mm,temperature controller and solar testing system. The SWHP-RFH system was tested from December to February during the heating season in Beijing,China under different operation situations. The test parameters include the outdoor air temperature,solar radiation intensity,indoor air temperature,radiation floor average surface temperature,average surface temperature of the building envelope,the inlet and outlet temperatures of solar collector,the temperature of water tank,the heat medium temperatures of heat pump condenser side and evaporator side,and the power consumption includes the water source heat pump system,the solar source heat pump system,the auxiliary heater and the radiant floor heating systems etc. The experimental results were used to calculate the collector efficiency,heat pump dynamic coefficient of performance (COP),total energy consumption and seasonal heating performance during the heating season. The results indicate that the performance of the compound source heat pump system is better than that of the air source heat pump system. Furthermore,some methods are suggested to improve the thermal performance of each component and the whole SWHP-RFH system.

Solar heating system

Science.gov (United States)

Schreyer, James M.; Dorsey, George F.

1982-01-01

An improved solar heating system in which the incident radiation of the sun is absorbed on collector panels, transferred to a storage unit and then distributed as heat for a building and the like. The improvement is obtained by utilizing a storage unit comprising separate compartments containing an array of materials having different melting points ranging from 75.degree. to 180.degree. F. The materials in the storage system are melted in accordance with the amount of heat absorbed from the sun and then transferred to the storage system. An efficient low volume storage system is provided by utilizing the latent heat of fusion of the materials as they change states in storing and releasing heat for distribution.

Thermal performance analysis of a solar heating plant

DEFF Research Database (Denmark)

Fan, Jianhua; Huang, Junpeng; Andersen, Ola Lie

was developed to calculate thermal performances of the plant. In the Trnsys model, three solar collector fields with a total solar collector area of 33,300 m2, a seasonal water pit heat storage of 75,000 m3, a simplified CO2 HP, a simplified ORC unit and a simplified wood chip boiler were included. The energy......Detailed measurements were carried out on a large scale solar heating plant located in southern Denmark in order to evaluate thermal performances of the plant. Based on the measurements, energy flows of the plant were evaluated. A modified Trnsys model of the Marstal solar heating plant...... consumption of the district heating net was modeled by volume flow rate and given forward and return temperatures of the district heating net. Weather data from a weather station at the site of the plant were used in the calculations. The Trnsys calculated yearly thermal performance of the solar heating plant...

Solar Energy: Heat Storage.

Science.gov (United States)

Knapp, Henry H., III

This module on heat storage is one of six in a series intended for use as supplements to currently available materials on solar energy and energy conservation. Together with the recommended texts and references (sources are identified), these modules provide an effective introduction to energy conservation and solar energy technologies. The module…

Energetic and financial evaluation of solar assisted heat pump space heating systems

International Nuclear Information System (INIS)

Bellos, Evangelos; Tzivanidis, Christos; Moschos, Konstantinos; Antonopoulos, Kimon A.

2016-01-01

Highlights: • Four solar heating systems are presented in this work. • Various combinations between solar collectors and heat pumps are presented. • The systems are compared energetically and financially. • The use of PV and an air source heat pump is the best choice financially. • The use of PVT with a water source heat pump is the best solution energetically. - Abstract: Using solar energy for space heating purposes consists an alternative way for substituting fossil fuel and grid electricity consumption. In this study, four solar assisted heat pump heating systems are designed, simulated and evaluated energetically and financially in order to determine the most attractive solution. The use of PV collectors with air source heat pump is compared to the use of FPC, PVT and FPC with PV coupled with a water source heat pump. A sensitivity analysis for the electricity cost is conducted because of the great variety of this parameter over the last years. The final results proved that for electricity cost up to 0.23 €/kW h the use of PV coupled with an air source heat pump is the most sustainable solution financially, while for higher electricity prices the coupling of PVT with an water source heat pump is the best choice. For the present electricity price of 0.2 €/kW h, 20 m"2 of PV is able to drive the air source heat pump with a yearly solar coverage of 67% leading to the most sustainable solution. Taking into account energetic aspects, the use of PVT leads to extremely low grid electricity consumption, fact that makes this technology the most environmental friendly.

The Effect of the Heat Flux on the Self-Ignition of Oriented Strand Board

Directory of Open Access Journals (Sweden)

Hirle Siegfried

2017-06-01

Full Text Available This article deals with the initiation phase of flaming and smouldering burning of oriented strand board. The influence of heat flux on thermal degradation of OSB boards, time to ignition, heat release rate and mass loss rate using thermal analysis and vertical electrical radiation panel methods were studied. Significant information on the influence of the heat flux density and the thickness of the material on time to ignition was obtained.

Efficiency improvement of a concentrated solar receiver for water heating system using porous medium

Science.gov (United States)

Prasartkaew, Boonrit

2018-01-01

This experimental study aims at investigating on the performance of a high temperature solar water heating system. To approach the high temperature, a porous-medium concentrated solar collector equipped with a focused solar heliostat were proposed. The proposed system comprised of two parts: a 0.7x0.7-m2 porous medium receiver, was installed on a 3-m tower, and a focused multi-flat-mirror solar heliostat with 25-m2 aperture area. The porous medium used in this study was the metal swarf or metal waste from lathing process. To know how the system efficiency could be improved by using such porous medium, the proposed system with- and without-porous medium were tested and the comparative study was performed. The experimental results show that, using porous medium for enhancing the heat transfer mechanism, the system thermal efficiency was increased about 25%. It can be concluded that the efficiency of the proposed system can be substantially improved by using the porous medium.

The market potential for solar heating plants in some European countries

Energy Technology Data Exchange (ETDEWEB)

Zinko, H; Bjaerklev, J.; Margen, P. [ZW Energiteknik AB, Nykoeping (Sweden)

1996-03-01

This study evaluates the market potential for solar collectors for residential heating in six European countries: Sweden, Denmark, Germany, Netherlands, Italy and Greece. The study is based on statistical information about the population, buildings, energy consumption and climatic conditions in the respective regions. The market potential was determined for systems supplying hot water and space heating in small houses and multi family houses, as well as for central block heating and district heating systems. Only systems with diurnal storage were taken into account. The technical potential was derived by analyzing the available roof areas, making allowance construction obstacles, unfavourable orientation, shadowing etc. Furthermore, commercial considerations, such as cost of competing energy sources, e.g. cogeneration and other low cost sources were considered. In accordance with our expectations, we assumed that the solar costs will decrease by 30 to 50% and that the market will increase by 30%/year during the next ten years, due to growing energy prices and by public financial support in an initial phase. It was found that there exists a commercial solar energy market in Greece for small systems and that the market could be nearly commercial in Italy. In the other countries the market must be stimulated by subsidies in order to take off. The total net potential for solar collectors in the six countries was found to about 100 Mm{sup 2} for small systems, and 60 Mm{sup 2} for large systems, corresponding to about 70 TWh/year. In a rough estimate we can say that the net solar collector market potential is about 1 m{sup 2}/inhabitant in north and central Europe, and 0.5m{sup 2} in south Europe. Although systems for seasonal storage were not included in our analysis, it is probable that these systems will increase the net market potential by a factor of 2-3. 9 refs

The market potential for solar heating plants in some European countries

International Nuclear Information System (INIS)

Zinko, H.; Bjaerklev, J.; Margen, P.

1996-03-01

This study evaluates the market potential for solar collectors for residential heating in six European countries: Sweden, Denmark, Germany, Netherlands, Italy and Greece. The study is based on statistical information about the population, buildings, energy consumption and climatic conditions in the respective regions. The market potential was determined for systems supplying hot water and space heating in small houses and multi family houses, as well as for central block heating and district heating systems. Only systems with diurnal storage were taken into account. The technical potential was derived by analyzing the available roof areas, making allowance construction obstacles, unfavourable orientation, shadowing etc. Furthermore, commercial considerations, such as cost of competing energy sources, e.g. cogeneration and other low cost sources were considered. In accordance with our expectations, we assumed that the solar costs will decrease by 30 to 50% and that the market will increase by 30%/year during the next ten years, due to growing energy prices and by public financial support in an initial phase. It was found that there exists a commercial solar energy market in Greece for small systems and that the market could be nearly commercial in Italy. In the other countries the market must be stimulated by subsidies in order to take off. The total net potential for solar collectors in the six countries was found to about 100 Mm 2 for small systems, and 60 Mm 2 for large systems, corresponding to about 70 TWh/year. In a rough estimate we can say that the net solar collector market potential is about 1 m 2 /inhabitant in north and central Europe, and 0.5m 2 in south Europe. Although systems for seasonal storage were not included in our analysis, it is probable that these systems will increase the net market potential by a factor of 2-3. 9 refs

Solar Energy for Space Heating & Hot Water.

Science.gov (United States)

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

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

Solar/electric heating systems for the future energy system

Energy Technology Data Exchange (ETDEWEB)

Furbo, S.; Dannemand, M.; Perers, B. [and others

2013-05-15

The aim of the project is to elucidate how individual heating units for single family houses are best designed in order to fit into the future energy system. The units are based on solar energy, electrical heating elements/heat pump, advanced heat storage tanks and advanced control systems. Heat is produced by solar collectors in sunny periods and by electrical heating elements/heat pump. The electrical heating elements/heat pump will be in operation in periods where the heat demand cannot be covered by solar energy. The aim is to use the auxiliary heating units when the electricity price is low, e.g. due to large electricity production by wind turbines. The unit is equipped with an advanced control system where the control of the auxiliary heating is based on forecasts of the electricity price, the heat demand and the solar energy production. Consequently, the control is based on weather forecasts. Three differently designed heating units are tested in a laboratory test facility. The systems are compared on the basis of: 1) energy consumption for the auxiliary heating; 2) energy cost for the auxiliary heating; 3) net utilized solar energy. Starting from a normal house a solar combi system (for hot water and house heating) can save 20-30% energy cost, alone, depending on sizing of collector area and storage volume. By replacing the heat storage with a smart tank based on electric heating elements and a smart control based on weather/load forecast and electricity price information 24 hours ahead, another 30-40% can be saved. That is: A solar heating system with a solar collector area of about 10 m{sup 2}, a smart tank based on electric heating element and a smart control system, can reduce the energy costs of the house by at least 50%. No increase of heat storage volume is needed to utilize the smart control. The savings in % are similar for different levels of building insulation. As expected a heat pump in the system can further reduce the auxiliary electricity

High performance passive solar heating system with heat pipe energy transfer

NARCIS (Netherlands)

Wit, de M.H.; Hensen, J.L.M.; Dijk, van H.A.L.; Brink, van den G.J.; Galen, van E; Ouden, den C.

1984-01-01

The aim of the project is to develop a passive solar heating system with a higher efficiency (regarding accumulation and transfer of solar heat into dwellings) than convential concrete thermal storage walls and with restricted extra costs for manufacturing the system. This is to be achieved by the

Solar heating systems

International Nuclear Information System (INIS)

1993-01-01

This report is based on a previous, related, one which was quantitative in character and relied on 500 telephone interviews with house-owners. The aim of this, following, report was to carry out a more deep-going, qualitative analysis focussed on persons who already own a solar heating system (purchased during 1992) or were/are considering having one installed. Aspects studied were the attitudes, behaviour and plans of these two groups with regard to solar heating systems. Some of the key questions asked concerned general attitudes to energy supply, advantages and disadvantages of using solar heating systems, related decision-making factors, installation problems, positive and negative expectations, evaluation of the information situation, suggestions related to information systems regarding themes etc., dissemination of information, sources of advice and information, economical considerations, satisfaction with the currently-owned system which would lead to the installation of another one in connection with the purchase of a new house. The results of this investigation directed at Danish house-owners are presented and discussed, and proposals for following activities within the marketing situation are given. It is concluded that the basic attitude in both groups strongly supports environmental protection, renewable energy sources and is influenced by considerations of prestige and independence. Constraint factors are confusion about environmental factors, insecurity in relation to the effect of established supplementary energy supply and suspicion with regard to the integrity of information received. (AB)

Direct measurements of inter-filament resistance in various multi-filamentary superconducting NbTi and Nb3Sn strands

NARCIS (Netherlands)

Zhou, Chao; Miyoshi, Y.; van Lanen, E.P.A.; Dhalle, Marc M.J.; Nijhuis, Arend

2012-01-01

For a proper characterization of multi-filamentary NbTi and Nb3Sn strands and a better understanding of their performance in short sample tests, as well as for increased understanding of inter-strand current redistribution in cabled conductors, a quantitative knowledge of the inter-filament

Heat exchanger for solar water heaters

Science.gov (United States)

Cash, M.; Krupnick, A. C.

1977-01-01

Proposed efficient double-walled heat exchanger prevents contamination of domestic water supply lines and indicates leakage automatically in solar as well as nonsolar heat sources using water as heat transfer medium.

Information campaign on solar heating for houses heated by electricity

International Nuclear Information System (INIS)

West, M.

1995-09-01

A number of NESA's (Danish electric power company) customers were offered the use of a solar water heating system for a short period of time. NESA was responsible for the marketing and consultancy service and worked in cooperation with local plumbers in connection with the delivery of the systems. The company contacted 450 households and its representatives visited 25 of these. 4 customers decided to purchase a solar heating system, fourteen decided to think about it, and four declared that they would not buy one. The company had reckoned with 25 purchases. It is concluded that the price of the solar heating systems was too high for prospective customers and the fact that they were not given a special offer had a negative effect. The economic aspect was absolutely the most important for them, especially the length of the payback period on the higher purchase system. Environmental protection aspects came second in their deliberations. NESA has a positive attitude to their customers' use of solar heating plants and recommends that households are offered very high quality consultancy services in connection with marketing. The project is described in detail. (AB)

Validated TRNSYS Model for Solar Assisted Space Heating System

International Nuclear Information System (INIS)

Abdalla, Nedal

2014-01-01

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

Solar district heating and seasonal heat storage - state of the art; Solare Nahwaerme und Saisonale Waermespeicherung - Stand der Technik

Energy Technology Data Exchange (ETDEWEB)

Pfeil, M.; Hahne, E. [Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung Baden-Wuerttemberg (ZSW), Stuttgart (Germany). Geschaeftsbereich Solarthermische Energietechnik; Lottner, V. [BEO Biologie, Energie Oekologie, Juelich (Germany); Schulz, M. [Stuttgart Univ. (Germany). Inst. fuer Thermodynamik und Waermetechnik

1998-02-01

Solar energy technology becomes more and more important for space and water heating of residential buildings. Compared to small systems for single-family houses, the specific investment cost of big solar plants is lower and a higher contribution of solar energy can be achieved. In central solar heating plants with seasonal storage (CSHPSS), more than 50% of the total heat demand of residential areas can be covered by solar energy. The first pilot plants for CSHPSS are operating in Germany since 1996. The first results of the accompanying monitoring program show good agreement between calculated and actual solar contribution. (orig.) [Deutsch] Die Nutzung solarer Niedertemperaturwaerme zur Brauchwassererwaermung und zur Beheizung von Wohngebaeuden erfaehrt in Deutschland ein immer groesseres Interesse. Solare Grossanlagen haben gegenueber solaren Kleinanlagen den Vorteil, dass mit geringeren Investitions- und Waermekosten groessere Anlagenertraege erzielt werden koennen. In Verbindung mit saisonaler Waermespeicherung erreichen solare Grossanlagen Deckungsanteile von 50% und darueber am Gesamtwaermebedarf von Wohnsiedlungen. Die ersten Pilotanlagen zur solaren Nahwaerme mit saisonalem Waermespeicher gingen 1996 in Betrieb und werden derzeit detailliert vermessen. Erste Ergebnisse zeigen, dass die vorausberechneten Werte fuer den Jahresenergieertrag erreicht werden koennen. (orig.)

Solar power from the supermarket. Water heating, space heating and air conditioning with solar collectors

Energy Technology Data Exchange (ETDEWEB)

1976-08-01

The different ways of utilizing solar energy are discussed. So far, top water heating is still the most practicable and most economical solution. Model houses with solar collectors, built by BBC and Philips, are dealt with in particular.

Two-Axis Solar Heat Collection Tracker System for Solar Thermal Applications

Directory of Open Access Journals (Sweden)

Tsung-Chieh Cheng

2013-01-01

Full Text Available An experimental study was performed to investigate the effect of using a continuous operation two-axes tracking on the solar heat energy collected. This heat-collection sun tracking which LDR (light dependent resistor sensors installed on the Fersnel lens was used to control the tracking path of the sun with programming method of control with a closed loop system. The control hardware was connected to a computer through Zigbee wireless module and it also can monitor the whole tracking process information on a computer screen. An experimental study was performed to investigate the effect of using two-axes tracking on the solar heat energy collected. The results indicate that sun tracking systems are being increasingly employed to enhance the efficiency of heat collection by polar-axis tracking of the sun. Besides, the heating power was also measured by designed power measurement module at the different focal length of Fresnel lens, and the design of shadow mask of LDR sensors is an important factor for solar photothermal applications. Moreover, the results also indicated that the best time to obtain the largest solar irradiation power is during 11:00 –13:00  in Taiwan.

Solar Water Heating System for Biodiesel Production

Directory of Open Access Journals (Sweden)

Syaifurrahman

2018-01-01

Full Text Available Nowadays, electricity become very expensive thing in some remote areas. Energy from solar panels give the solution as renewable energy that is environment friendly. West Borneo is located on the equator where the sun shines for almost 10-15 hours/day. Solar water heating system which is includes storage tank and solar collections becomes a cost-effective way to generate the energy. Solar panel heat water is delivered to water in storage tank. Hot water is used as hot fluid in biodiesel jacked reactor. The purposes of this research are to design Solar Water Heating System for Biodiesel Production and measure the rate of heat-transfer water in storage tank. This test has done for 6 days, every day from 8.30 am until 2.30 pm. Storage tank and collection are made from stainless steel and polystyrene a well-insulated. The results show that the heater can be reach at 50ºC for ±2.5 hours and the maximum temperature is 62ºC where the average of light intensity is 1280 lux.

Solar Water Heating System for Biodiesel Production

Science.gov (United States)

Syaifurrahman; Usman, A. Gani; Rinjani, Rakasiwi

2018-02-01

Nowadays, electricity become very expensive thing in some remote areas. Energy from solar panels give the solution as renewable energy that is environment friendly. West Borneo is located on the equator where the sun shines for almost 10-15 hours/day. Solar water heating system which is includes storage tank and solar collections becomes a cost-effective way to generate the energy. Solar panel heat water is delivered to water in storage tank. Hot water is used as hot fluid in biodiesel jacked reactor. The purposes of this research are to design Solar Water Heating System for Biodiesel Production and measure the rate of heat-transfer water in storage tank. This test has done for 6 days, every day from 8.30 am until 2.30 pm. Storage tank and collection are made from stainless steel and polystyrene a well-insulated. The results show that the heater can be reach at 50ºC for ±2.5 hours and the maximum temperature is 62ºC where the average of light intensity is 1280 lux.

Potential for solar space heating in Scotland

Energy Technology Data Exchange (ETDEWEB)

Macgregor, A W.K.

1980-07-01

This paper investigates the relative effectiveness of passive-type solar-assisted space heating systems at various latitudes within the British Isles. A comparison is made of the useful solar gain of the same system linked to the same house at four different locations. Month-by-month energy balances indicate that the annual useful solar contribution at the highest latitude (Lerwick, 60 deg N) is about 35% higher than at the lowest latitude (Kew, 53 deg N). The main reason for this difference is the higher heating loads in the north, particularly outside the winter months. The estimated available irradiation on south-facing vertical surfaces was almost the same at all four locations. Previous work in the UK indicates that, contrary to the conclusions in this paper, more southerly latitudes were the most favorable for solar space heating. The reasons for the disparity are discussed. It is recommended that research and development of passive solar-assisted space heating systems should be most vigorously pursued in the more northerly latitudes of the British Isles, where both the potential benefit and the need are greatest.

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

Directory of Open Access Journals (Sweden)

Giedrius Šiupšinskas

2012-12-01

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

Prototype solar heating and hot water system

Science.gov (United States)

1977-01-01

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

Solar heating of the produced water of petroleum; Aquecimento solar da agua produzida de petroleo

Energy Technology Data Exchange (ETDEWEB)

Santos, Rogerio Pitanga; Chiavone-Filho, Osvaldo; Bezerra, Magna A. Santos; Melo, Josette Lourdes Sousa de; Oliveira, Jackson Araujo de; Ramos, Rafael E. Moura [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Schuhli, Juliana Bregenski; Andrade, Vivian Tavares de [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

2008-07-01

In this work, experimental data of solar heating for common water and saline solution were measured. The solar heater is formed by a flat-plane collector and a thermal reservoir ('boiler'). The objective is to quantify the variation of fluids' temperature, and correlate it to environment variables, especially solar irradiation. Thereby, it is possible to estimate the solar heating of produced water of petroleum. The solar heater is part of a system of treatment of produced water, and its function is to pre-heat the fluid that enters into the solar distiller, increasing the productivity of distilled water. A saline solution that represents produced water was used in the experiments, using sodium chloride (1000 ppm). The experimental data demonstrates that the solar heater is capable to heat the fluid to temperatures close to 70 deg C, reaching temperatures close to 50 deg C even during cloudy days with low solar radiation. Furthermore, the solar collector energy system provides a higher rate of heating and trough of the thermal reservoir the temperature can remain longer. These are important aspects to the integration with solar distillation. (author)

Solar heating of the produced water of petroleum; Aquecimento solar da agua produzida de petroleo

Energy Technology Data Exchange (ETDEWEB)

Santos, Rogerio Pitanga; Chiavone-Filho, Osvaldo; Bezerra, Magna A. Santos; Melo, Josette Lourdes Sousa de; Oliveira, Jackson Araujo de; Ramos, Rafael E. Moura [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Schuhli, Juliana Bregenski; Andrade, Vivian Tavares de [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

2008-07-01

In this work, experimental data of solar heating for common water and saline solution were measured. The solar heater is formed by a flat-plane collector and a thermal reservoir ('boiler'). The objective is to quantify the variation of fluids' temperature, and correlate it to environment variables, especially solar irradiation. Thereby, it is possible to estimate the solar heating of produced water of petroleum. The solar heater is part of a system of treatment of produced water, and its function is to pre-heat the fluid that enters into the solar distiller, increasing the productivity of distilled water. A saline solution that represents produced water was used in the experiments, using sodium chloride (1000 ppm). The experimental data demonstrates that the solar heater is capable to heat the fluid to temperatures close to 70 deg C, reaching temperatures close to 50 deg C even during cloudy days with low solar radiation. Furthermore, the solar collector energy system provides a higher rate of heating and trough of the thermal reservoir the temperature can remain longer. These are important aspects to the integration with solar distillation. (author)

Solar Heating in Uppsala : A case study of the solar heating system in the neighbourhood Haubitsen in Uppsala

OpenAIRE

Blomqvist, Emelie; Häger, Klara; Wiborgh, Malin

2012-01-01

The housing corporation Uppsalahem has installed asolar heating system in the neighbourhood Haubitsen,which was renovated in 2011. This report examineshow much energy the solar heating system is expectedto generate and which factors could improve theefficiency. Simulations suggest that the solar heatingsystem can to cover about 22 per cent of the domestichot water demand in Haubitsen, which corresponds to50 MWh for a year. If some factors, such as the tilt ofthe solar collectors would have be...

Anchoring device enabling relaxation of a multi-strand prestressing cable

International Nuclear Information System (INIS)

1979-01-01

Anchoring device, in a concrete structure, for a multi-strand prestressing cable, enabling the cable to be stressed or relaxed, comprising: (a) an axisymmetrical block, fitted with channels to enable the cable strands to be stressed and anchored through this block, (b) a duct with its opening splayed to a diameter greater than that of the block over a length corresponding to the stretching of the cable when being stressed, (c) a round bearing plate on the concrete around the expanded hole of the duct and (d) at least one intermediate removable bearing piece coming between the edge of the block and the internal edge of the plate. The removable parts are crown sectors of which the opposite bearing faces of each are slanted with respect to the centre line of the block and orientated in the same direction so as to transmit the cable stress at an angle from the block to the edge of the bearing plate [fr

Heat recovery from ground below the solar pond

NARCIS (Netherlands)

Ganguly, S.; Date, Abhijit; Akbarzadeh, Aliakbar

2017-01-01

The method of heat recovery from the ground below solar ponds is investigated in the present brief note. Solar ponds lose considerable amount of heat from its bottom to the ground due to temperature gradient between them. This waste heat from ground, which is at different temperature at different

Optimization of Solar Water Heating System under Time and Spatial Partition Heating in Rural Dwellings

Directory of Open Access Journals (Sweden)

Yanfeng Liu

2017-10-01

Full Text Available This paper proposes the application of time and spatial partition heating to a solar water heating system. The heating effect and system performance were analyzed under the continuous and whole space heating and time and spatial partition heating using TRNSYS. The results were validated by comparing with the test results of the demonstration building. Compared to continuous and whole space heating, the use of time and spatial partition heating increases the solar fraction by 16.5%, reduces the auxiliary heating by 7390 MJ, and reduces the annual operation cost by 2010 RMB. Under time and spatial partition heating, optimization analyses were conducted for the two system capacity parameters of the solar collector area and tank volume and the one operation parameter of auxiliary heater setting outlet temperature. The results showed that a reasonable choice of the solar collector area can reduce the dynamic annual cost, the increased tank volume is advantageous to heat storage, and the auxiliary heater setting outlet temperature have greater influence on the indoor heating effect. The advanced opening of solar water heating system and the normal opening of passive air vents are recommended. Based on the comparison of the two modes, the time and spatial partition heating technology is a better choice for rural dwellings.

Solar system for domestic hot water and space heating

Energy Technology Data Exchange (ETDEWEB)

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

1997-12-31

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

Solar system for domestic hot water and space heating

Energy Technology Data Exchange (ETDEWEB)

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

1998-12-31

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

Experiments on novel solar heating and cooling system

International Nuclear Information System (INIS)

Wang Yiping; Cui Yong; Zhu Li; Han Lijun

2008-01-01

Solar heating and nocturnal radiant cooling techniques are united to produce a novel solar heating and cooling system. The radiant panel with both heating and cooling functions can be used as structural materials for the building envelope, which realizes true building integrated utilization of solar energy. Based on the natural circulation principle, the operation status can be changed automatically between the heating cycle and the cooling cycle. System performances under different climate conditions using different covers on the radiant panel are studied. The results show that the novel solar heating and cooling system has good performance of heating and cooling. For the no cover system, the daily average heat collecting efficiency is 52% with the maximum efficiency of 73%, while at night, the cooling capacity is about 47 W/m 2 on a sunny day. On a cloudy day, the daily average heat collecting efficiency is 47% with the maximum of 84%, while the cooling capacity is about 33 W/m 2 . As a polycarbonate (PC) panel or polyethylene film are used as covers, the maximum heat collecting efficiencies are 75% and 72% and the daily average heat collecting efficiencies are 61% and 58%, while the cooling capacities are 50 W/m 2 and 36 W/m 2 , respectively

Kinetic Physics of the Solar Corona and Solar Wind

Directory of Open Access Journals (Sweden)

Marsch Eckart

2006-07-01

Full Text Available Kinetic plasma physics of the solar corona and solar wind are reviewed with emphasis on the theoretical understanding of the in situ measurements of solar wind particles and waves, as well as on the remote-sensing observations of the solar corona made by means of ultraviolet spectroscopy and imaging. In order to explain coronal and interplanetary heating, the microphysics of the dissipation of various forms of mechanical, electric and magnetic energy at small scales (e.g., contained in plasma waves, turbulences or non-uniform flows must be addressed. We therefore scrutinise the basic assumptions underlying the classical transport theory and the related collisional heating rates, and also describe alternatives associated with wave-particle interactions. We elucidate the kinetic aspects of heating the solar corona and interplanetary plasma through Landau- and cyclotron-resonant damping of plasma waves, and analyse in detail wave absorption and micro instabilities. Important aspects (virtues and limitations of fluid models, either single- and multi-species or magnetohydrodynamic and multi-moment models, for coronal heating and solar wind acceleration are critically discussed. Also, kinetic model results which were recently obtained by numerically solving the Vlasov–Boltzmann equation in a coronal funnel and hole are presented. Promising areas and perspectives for future research are outlined finally.

Solar heating and cooling demonstration project at the Florida Solar Energy Center

Energy Technology Data Exchange (ETDEWEB)

Hankins, J.D.

1980-02-01

The retrofitted solar heating and cooling system installed at the Florida Solar Energy Center is described. Information is provided on the system's test, operation, controls, hardware and installation, including detailed drawings. The Center's office building, approximately 5000 square feet of space, with solar air conditioning and heating as a demonstration of the technical feasibility is located just north of Port Canaveral, Florida. The system was designed to supply approximately 70% of the annual cooling and 100% of the heating load. The project provides unique high-temperature, non-imaging, non-tracking, evacuated-tube collectors. The design of the system was kept simple and employs five hydronic loops. They are energy collection, chilled water production, space cooling, space heating and energy rejection.

Testing, development and demonstration of large scale solar district heating systems

DEFF Research Database (Denmark)

Furbo, Simon; Fan, Jianhua; Perers, Bengt

2015-01-01

In 2013-2014 the project “Testing, development and demonstration of large scale solar district heating systems” was carried out within the Sino-Danish Renewable Energy Development Programme, the so called RED programme jointly developed by the Chinese and Danish governments. In the project Danish...... know how on solar heating plants and solar heating test technology have been transferred from Denmark to China, large solar heating systems have been promoted in China, test capabilities on solar collectors and large scale solar heating systems have been improved in China and Danish-Chinese cooperation...

Hydrophobic Light-to-Heat Conversion Membranes with Self-Healing Ability for Interfacial Solar Heating

KAUST Repository

Zhang, Lianbin

2015-07-01

Self-healing hydrophobic light-to-heat conversion membranes for interfacial solar heating are fabricated by deposition of light-to-heat conversion material of polypyrrole onto porous stainless steel mesh, followed by hydrophobic fluoroalkylsilane modification. The mesh-based membranes spontaneously stay at the water–air interface, collect and convert solar light into heat, and locally heat only the water surface for an enhanced evaporation.

Hydrophobic Light-to-Heat Conversion Membranes with Self-Healing Ability for Interfacial Solar Heating

KAUST Repository

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

2015-01-01

Self-healing hydrophobic light-to-heat conversion membranes for interfacial solar heating are fabricated by deposition of light-to-heat conversion material of polypyrrole onto porous stainless steel mesh, followed by hydrophobic fluoroalkylsilane modification. The mesh-based membranes spontaneously stay at the water–air interface, collect and convert solar light into heat, and locally heat only the water surface for an enhanced evaporation.

Dynamic performance of a novel solar photovoltaic/loop-heat-pipe heat pump system

International Nuclear Information System (INIS)

Zhang, Xingxing; Zhao, Xudong; Shen, Jingchun; Xu, Jihuan; Yu, Xiaotong

2014-01-01

Highlights: • A transient model was developed to predict dynamic performance of new PV/LHP system. • The model accuracy was validated by experiment giving less than 9% in error. • The new system had basic and advanced performance coefficients of 5.51 and 8.71. • The new system had a COP 1.5–4 times that for conventional heat pump systems. • The new system had higher exergetic efficiency than PV and solar collector systems. - Abstract: Objective of the paper is to present an investigation into the dynamic performance of a novel solar photovoltaic/loop-heat-pipe (PV/LHP) heat pump system for potential use in space heating or hot water generation. The methods used include theoretical computer simulation, experimental verification, analysis and comparison. The fundamental equations governing the transient processes of solar transmission, heat transfer, fluid flow and photovoltaic (PV) power generation were appropriately integrated to address the energy balances occurring in different parts of the system, e.g., glazing cover, PV cells, fin sheet, loop heat pipe, heat pump cycle and water tank. A dedicated computer model was developed to resolve the above grouping equations and consequently predict the system’s dynamic performance. An experimental rig was constructed and operated under the real weather conditions for over one week in Shanghai to evaluate the system living performance, which was undertaken by measurement of various operational parameters, e.g., solar radiation, photovoltaic power generation, temperatures and heat pump compressor consumption. On the basis of the first- (energetic) and second- (exergetic) thermodynamic laws, an overall evaluation approach was proposed and applied to conduct both quantitative and qualitative analysis of the PV/LHP module’s efficiency, which involved use of the basic thermal performance coefficient (COP th ) and the advanced performance coefficient (COP PV/T ) of such a system. Moreover, a simple comparison

Three story residence with solar heat--Manchester, New Hampshire

Science.gov (United States)

1981-01-01

When heat lost through ducts is counted for accurate performance assessment, solar energy supplied 56 percent of building's space heating load. Average outdoor temperature was 53 degrees F; average indoor temperature was 69 degrees F. System operating modes included heating from solar collectors, storing heat, heating from storage, auxiliary heating with oil fired furnace, summer venting, and hot water preheating.

Monitoring of Danish marketed solar heating systems

International Nuclear Information System (INIS)

Ellehauge, K.

1993-01-01

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

Building integration of concentrating solar systems for heating applications

International Nuclear Information System (INIS)

Tsoutsou, Sapfo; Infante Ferreira, Carlos; Krieg, Jan; Ezzahiri, Mohamed

2014-01-01

A new solar collection system integrated on the façade of a building is investigated for Dutch climate conditions. The solar collection system includes a solar façade, a receiver tube and 10 Fresnel lenses. The Fresnel lenses Fresnel lenses considered were linear, non-imaging, line – focused with a system tracking the position of the sun that ensures vertical incidence of the direct solar radiation on the lenses. For the heating system a double-effect absorption heat pump, which requires high temperature of the heating fluid, was used, working with water and lithium-bromide as refrigerant and solution respectively. The Fresnel lens system is connected with the absorption heat pump through a thermal energy storage tank which accumulates the heat from the Fresnel lens system to provide it to the high pressure generator of the absorption heat pump. - Highlights: • The integration of Fresnel lenses in solar thermal building façades is investigated. • Using building integrated Fresnel lenses, 43% heating energy can be saved. • Energy savings in Mediterranean countries are significantly larger. • The absorption heat pump could make great contribution to energy savings for Dutch climate conditions

A heat receiver design for solar dynamic space power systems

Science.gov (United States)

Baker, Karl W.; Dustin, Miles O.; Crane, Roger

1990-01-01

An advanced heat pipe receiver designed for a solar dynamic space power system is described. The power system consists of a solar concentrator, solar heat receiver, Stirling heat engine, linear alternator and waste heat radiator. The solar concentrator focuses the sun's energy into a heat receiver. The engine and alternator convert a portion of this energy to electric power and the remaining heat is rejected by a waste heat radiator. Primary liquid metal heat pipes transport heat energy to the Stirling engine. Thermal energy storage allows this power system to operate during the shade portion of an orbit. Lithium fluoride/calcium fluoride eutectic is the thermal energy storage material. Thermal energy storage canisters are attached to the midsection of each heat pipe. The primary heat pipes pass through a secondary vapor cavity heat pipe near the engine and receiver interface. The secondary vapor cavity heat pipe serves three important functions. First, it smooths out hot spots in the solar cavity and provides even distribution of heat to the engine. Second, the event of a heat pipe failure, the secondary heat pipe cavity can efficiently transfer heat from other operating primary heat pipes to the engine heat exchanger of the defunct heat pipe. Third, the secondary heat pipe vapor cavity reduces temperature drops caused by heat flow into the engine. This unique design provides a high level of reliability and performance.

Optimization of the heat treatment schedule for next european dipole (NED) powder in tube $Nb_{3}Sn$ strand

CERN Document Server

Boutboul, T; den Ouden, A; Pedrini, D; Volpini, G

2009-01-01

A Nb3Sn strand was successfully developed by the company SMI for Next European Dipole (NED) activity and on the basis of Powder-In-Tube (PIT) method. This strand, after the standard reaction recommended by the firm (84 h @ 675 oC), presents attractive performances as a critical current density in the non-copper part of ~ 2500 A/mm2 for 4.2 K and 12 T applied field, an effective filament diameter of ~ 50 μm and limited flux jumps at low magnetic fields. Heat treatment optimization studies are currently performed at CERN to try to optimize the strand electric abilities. For this purpose, various heat treatment schedules were already investigated with a plateau temperature as low as 625 oC. The preliminary results of these studies are summarized here.

Heat of Fusion Storage with High Solar Fraction for Solar Low Energy Buildings

DEFF Research Database (Denmark)

Schultz, Jørgen Munthe; Furbo, Simon

The paper presents the results of a theoretical investigation of use of phase change materials (PCM’s) with active use of super cooling as a measure for obtaining partly heat loss free seasonal storages for solar combi-systems with 100% coverage of the energy demand of both space heating and dome......The paper presents the results of a theoretical investigation of use of phase change materials (PCM’s) with active use of super cooling as a measure for obtaining partly heat loss free seasonal storages for solar combi-systems with 100% coverage of the energy demand of both space heating...... and domestic hot water. The work is part of the IEA Solar Heating & Cooling Programme Task 32 “Advanced Storage Concepts for Solar Buildings”. The investigations are based on a newly developed TRNSYS type for simulation of a PCM-storage with controlled super-cooling. The super-cooling makes it possible to let...... storage parts already melted to cool down to surrounding temperature without solidification in which state that part of the storage will be heat loss free but still will hold the latent heat in form of the heat of fusion. At the time of energy demand the solidification of the super-cooled storage part...

Experimental investigation and feasibility analysis on a capillary radiant heating system based on solar and air source heat pump dual heat source

International Nuclear Information System (INIS)

Zhao, M.; Gu, Z.L.; Kang, W.B.; Liu, X.; Zhang, L.Y.; Jin, L.W.; Zhang, Q.L.

2017-01-01

Graphical abstract: (a) Vertical temperature gradient in Case 3, (b) PMV and PPD of the test room in Case 3, (c) operating time of SPCTS and ASHP systems in Case 3 and (d) the proportion of SPCTS operating time. - Highlights: • A capillary heating system based on solar and air source heat pump was developed. • Influence of supply water temperature on solar energy saving rate was investigated. • Heating performance and thermal comfort of capillary heating system were analyzed. • Low temperature heating with capillary is suitable for solar heating system. - Abstract: Due to sustainable development, solar energy has drawn much attention and been widely applied in buildings. However, the application of solar energy is limited because of its instability, intermittency and low energy density in winter. In order to use low density and instable solar energy source for heating and improve the utilization efficiency of solar energy, a solar phase change thermal storage (SPCTS) heating system using a radiant-capillary-terminal (RCT) to effectively match the low temperature hot water, a phase change thermal storage (PCTS) to store and continuously utilize the solar energy, and an air source heat pump (ASHP) as an alternate energy, was proposed and set up in this research. Series of experiments were conducted to obtain the relation between the solar radiation utilization rate and the heating supply temperatures, and to evaluate the performance of the RCT module and the indoor thermal environment of the system for its practical application in a residential building in the north-western City of Xi’an, China. The results show that energy saving of the solar heating system can be significantly improved by reducing the supplied water temperature, and the supplied water temperature of the RCT would be no more than 35 °C. The capillary radiation heating can adopt a lower water temperature and create a good thermal comfort environment as well. These results may lead to the

Consumer impacts on dividends from solar water heating

Energy Technology Data Exchange (ETDEWEB)

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

2011-01-15

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

Observations and Numerical Models of Solar Coronal Heating Associated with Spicules

Energy Technology Data Exchange (ETDEWEB)

Pontieu, B. De; Martinez-Sykora, J. [Lockheed Martin Solar and Astrophysics Laboratory, 3251 Hanover Street, Org. A021S, Building 252, Palo Alto, CA 94304 (United States); Moortel, I. De [School of Mathematics and Statistics, University of St Andrews, St Andrews, Fife KY16 9SS (United Kingdom); McIntosh, S. W. [High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307 (United States)

2017-08-20

Spicules have been proposed as significant contributors to the mass and energy balance of the corona. While previous observations have provided a glimpse of short-lived transient brightenings in the corona that are associated with spicules, these observations have been contested and are the subject of a vigorous debate both on the modeling and the observational side. Therefore, it remains unclear whether plasma is heated to coronal temperatures in association with spicules. We use high-resolution observations of the chromosphere and transition region (TR) with the Interface Region Imaging Spectrograph and of the corona with the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory to show evidence of the formation of coronal structures associated with spicular mass ejections and heating of plasma to TR and coronal temperatures. Our observations suggest that a significant fraction of the highly dynamic loop fan environment associated with plage regions may be the result of the formation of such new coronal strands, a process that previously had been interpreted as the propagation of transient propagating coronal disturbances. Our observations are supported by 2.5D radiative MHD simulations that show heating to coronal temperatures in association with spicules. Our results suggest that heating and strong flows play an important role in maintaining the substructure of loop fans, in addition to the waves that permeate this low coronal environment.

The heat recovery with heat transfer methods from solar photovoltaic systems

International Nuclear Information System (INIS)

Özakın, A. N.; Karsli, S.; Kaya, F.; Güllüce, H.

2016-01-01

Although there are many fluctuations in energy prices, they seems like rising day by day. Thus energy recovery systems have increasingly trend. Photovoltaic systems converts solar radiation directly into electrical energy thanks to semiconductors. But due to the nature of semiconductors, whole of solar energy cannot turn into electrical energy and the remaining energy turns into waste heat. The aim of this research is evaluate this waste heat energy by air cooling system. So, the energy efficiency of the system will be increased using appropriate heat transfer technologies such as fin, turbulator etc. (paper)

Proceedings of the General Assembly 2016 on solar heat

International Nuclear Information System (INIS)

Gibert, Francois; Porcheyre, Edwige; Mouvet, Celine; Humbert, Adrien; SEGUIS, Anne-Sophie; Manteau, Olivier; Roland, Joel; LAPLAGNE, Valerie; Chavagnac, Jean-Francois; Godin, Olivier; Long, Guy; Tamri, Laila; Parrens, Gael; Neveux, Guillaume; Fourmessol, Thomas; Cholin, Xavier; Mugnier, Daniel; Berthomieu, Nadine; Loyen, Richard; Benabdelkarim, Mohamed; Daclin, Julien; Dejonghe, Joseph; Bealu, Christophe; Alsafar, Thaer; Crozier, Benoit; Ramonet, Corinne; Meriau, Jean-Paul

2016-10-01

After an opening speech, a first set of contributions addressed the impact of the evolutions of building energetic regulations on the solar heat market for new buildings: towards positive energy and low carbon buildings with the Energy-Carbon experimentation; results of the RT2012 study on technical and economic solutions of solar hot water; opportunities and constraints of the integration of solar energy into projects. The second set addressed new opportunities in terms of technical innovations and services for connected thermal solar: a harmonised framework proposed by industries for individual equipment; returns on experience from industrials; impact of connected solar on the operator's profession. The third session discussed perspectives for the French sector: synthesis of a prospective study on the economic and social potential of the solar sector in France; a new MOOC on energy labelling of solar heating and water heaters. The fourth session presented some recent advances dealing with SOCOL for a collective, performing and sustainable production of solar heat: new SOCOL tools; a new design and sizing software; integration of the SOCOL quality approach in the 2017 Heat Fund. The fifth set of contributions addressed the issue of self-consumption and its possible dynamic impact on the production of solar electrons and calories: approach to burden management and reduction of CO_2 emissions; innovation at the service of photovoltaic performance by using phase-change materials; the example of the future House of the Ile-de-France in Paris. The last session addressed local dynamics noticed in relationship with the use of solar heat: the SOLTHERM plan in Wallonia; local initiatives in the farming sector; a large project by Lyon Habitat within the frame of an ADEME program (large installations). A closing speech proposes a synthesis on how to find growth again and reach the national ambitious objective for solar heat by 2023

Multi-crystalline II-VI based multijunction solar cells and modules

Science.gov (United States)

Hardin, Brian E.; Connor, Stephen T.; Groves, James R.; Peters, Craig H.

2015-06-30

Multi-crystalline group II-VI solar cells and methods for fabrication of same are disclosed herein. A multi-crystalline group II-VI solar cell includes a first photovoltaic sub-cell comprising silicon, a tunnel junction, and a multi-crystalline second photovoltaic sub-cell. A plurality of the multi-crystalline group II-VI solar cells can be interconnected to form low cost, high throughput flat panel, low light concentration, and/or medium light concentration photovoltaic modules or devices.

Energy Savings for Solar Heating Systems

DEFF Research Database (Denmark)

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

2004-01-01

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

Theoretical models of Kapton heating in solar array geometries

Science.gov (United States)

Morton, Thomas L.

1992-01-01

In an effort to understand pyrolysis of Kapton in solar arrays, a computational heat transfer program was developed. This model allows for the different materials and widely divergent length scales of the problem. The present status of the calculation indicates that thin copper traces surrounded by Kapton and carrying large currents can show large temperature increases, but the other configurations seen on solar arrays have adequate heat sinks to prevent substantial heating of the Kapton. Electron currents from the ambient plasma can also contribute to heating of thin traces. Since Kapton is stable at temperatures as high as 600 C, this indicates that it should be suitable for solar array applications. There are indications that the adhesive sued in solar arrays may be a strong contributor to the pyrolysis problem seen in solar array vacuum chamber tests.

Solar process heat is becoming sexy

Energy Technology Data Exchange (ETDEWEB)

Morhart, Alexander

2011-07-01

Linear concentrating solar collectors for solar medium-temperature process heat: an exotic niche market has turned into a wide range of offers for commercial and private customers - and there is no end in sight to the technical developments. (orig.)

Wave heating of the solar atmosphere

Science.gov (United States)

Arregui, Iñigo

2015-04-01

Magnetic waves are a relevant component in the dynamics of the solar atmosphere. Their significance has increased because of their potential as a remote diagnostic tool and their presumed contribution to plasma heating processes. We discuss our current understanding of coronal heating by magnetic waves, based on recent observational evidence and theoretical advances. The discussion starts with a selection of observational discoveries that have brought magnetic waves to the forefront of the coronal heating discussion. Then, our theoretical understanding of the nature and properties of the observed waves and the physical processes that have been proposed to explain observations are described. Particular attention is given to the sequence of processes that link observed wave characteristics with concealed energy transport, dissipation and heat conversion. We conclude with a commentary on how the combination of theory and observations should help us to understand and quantify magnetic wave heating of the solar atmosphere.

Study of non-domestic applications for active solar heating

Energy Technology Data Exchange (ETDEWEB)

Stammers, J.R.

1997-11-01

The UK Department of Trade and Industry (through ETSU) commissioned this study as part of its active solar programme. It was carried out from October 1996 to June 1997. The objective was to assess the potential for the use of active solar heating in non-domestic applications. The study was carried out by searching the literature, carrying out case studies and interviewing members of the solar industry and experts in other fields. There are currently about 45-50 active solar non-domestic schemes in operation in the UK, mostly for heating tap water in buildings of different types. The biggest potential for future non-domestic sales also lies in solar water heating for buildings. Most of the opportunities seem to be in the following building types: ablutions blocks in caravan and holiday camps, sheltered flats and hostels, nursing homes, office buildings, hotels and guest houses, and schools occupied during the summer. There are some other building types which might present niche markets for solar water heating. The market for active solar systems in space heating and cooling appears to be negligible. There is one other market for active solar heating in the non-domestic building sector. This is for warming water used to maintain stand-by generators at a temperature which allows them to kick in without delay in the event of a mains power failure. The main market is in buildings housing computers which control the provision of vital services, e.g. electricity, water and gas. (author)

Solar/electric heating systems for the future energy system

DEFF Research Database (Denmark)

Furbo, Simon; Dannemand, Mark; Perers, Bengt

elements/heat pump, advanced heat storage tanks and advanced control systems. Heat is produced by solar collectors in sunny periods and by electrical heating elements/heat pump. The electrical heating elements/heat pump will be in operation in periods where the heat demand cannot be covered by solar energy....... The aim is to use the auxiliary heating units when the electricity price is low, e.g. due to large electricity production by wind turbines. The unit is equipped with an advanced control system where the control of the auxiliary heating is based on forecasts of the electricity price, the heat demand...

Improved solar heating systems

Science.gov (United States)

Schreyer, J.M.; Dorsey, G.F.

1980-05-16

An improved solar heating system is described in which the incident radiation of the sun is absorbed on collector panels, transferred to a storage unit and then distributed as heat for a building and the like. The improvement is obtained by utilizing a storage unit comprising separate compartments containing an array of materials having different melting points ranging from 75 to 180/sup 0/F. The materials in the storage system are melted in accordance with the amount of heat absorbed from the sun and then transferred to the storage system. An efficient low volume storage system is provided by utilizing the latent heat of fusion of the materials as they change states in storing ad releasing heat for distribution.

CISBAT 2007 - Solar collectors (heat and electricity)

International Nuclear Information System (INIS)

2007-01-01

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

Performance analysis of a solar-assisted swimming pool heating system

Energy Technology Data Exchange (ETDEWEB)

Alkhamis, A I; Sherif, S A [Miami Univ., Coral Gables, FL (United States). Dept. of Mechanical Engineering

1991-12-31

This paper discusses feasibility studies for a solar-assisted heating system using a computer simulation program. The solar heating is accomplished by employing hot water generated by heat exchange with the solar collector working fluid. The performance of the system is analysed from both thermodynamic and economic standpoints and general conclusions are reached. 17 refs., 7 figs.

Energy Savings for Solar Heating Systems

DEFF Research Database (Denmark)

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

2006-01-01

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

Heat losses and thermal performance of commercial combined solar and pellet heating systems

OpenAIRE

Fiedler, Frank; Persson, Tomas; Bales, Chris; Nordlander, Svante

2004-01-01

Various pellet heating systems are marketed in Sweden, some of them in combination with a solar heating system. Several types of pellet heating units are available and can be used for a combined system. This article compares four typical combined solar and pellet heating systems: System 1 and 2 two with a pellet stove, system 3 with a store integrated pellet burner and system 4 with a pellet boiler. The lower efficiency of pellet heaters compared to oil or gas heaters increases the primary en...

Investigations of Intelligent Solar Heating Systems for Single Family House

DEFF Research Database (Denmark)

Andersen, Elsa; Chen, Ziqian; Fan, Jianhua

2014-01-01

Three differently designed intelligent solar heating systems are investigated experimentally in a test facility. The systems provide all the needed yearly heating demand in single family houses. The systems are based on highly stratified tanks with variable auxiliary heated volumes. The tank is a......, the control strategy of intelligent solar heating systems is investigated and the yearly auxiliary energy use of the systems and the electricity price for supplying the consumers with domestic hot water and space heating are calculated....... systems.The system will be equipped with an intelligent control system where the control of the electrical heating element(s)/heat pump is based on forecasts of the variable electricity price, the heating demand and the solar energy production.By means of numerical models of the systems made in Trnsys......Three differently designed intelligent solar heating systems are investigated experimentally in a test facility. The systems provide all the needed yearly heating demand in single family houses. The systems are based on highly stratified tanks with variable auxiliary heated volumes. The tank...

Theoretical energy and exergy analyses of solar assisted heat pump space heating system

Directory of Open Access Journals (Sweden)

Atmaca Ibrahim

2014-01-01

Full Text Available Due to use of alternative energy sources and energy efficient operation, heat pumps come into prominence in recent years. Especially in solar-assisted heat pumps, sizing the required system is difficult and arduous task in order to provide optimum working conditions. Therefore, in this study solar assisted indirect expanded heat pump space heating system is simulated and the results of the simulation are compared with available experimental data in the literature in order to present reliability of the model. Solar radiation values in the selected region are estimated with the simulation. The case study is applied and simulation results are given for Antalya, Turkey. Collector type and storage tank capacity effects on the consumed power of the compressor, COP of the heat pump and the overall system are estimated with the simulation, depending on the radiation data, collector surface area and the heating capacity of the space. Exergy analysis is also performed with the simulation and irreversibility, improvement potentials and exergy efficiencies of the heat pump and system components are estimated.

Measuring solar reflectance - Part I: Defining a metric that accurately predicts solar heat gain

Energy Technology Data Exchange (ETDEWEB)

Levinson, Ronnen; Akbari, Hashem; Berdahl, Paul [Heat Island Group, Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States)

2010-09-15

Solar reflectance can vary with the spectral and angular distributions of incident sunlight, which in turn depend on surface orientation, solar position and atmospheric conditions. A widely used solar reflectance metric based on the ASTM Standard E891 beam-normal solar spectral irradiance underestimates the solar heat gain of a spectrally selective ''cool colored'' surface because this irradiance contains a greater fraction of near-infrared light than typically found in ordinary (unconcentrated) global sunlight. At mainland US latitudes, this metric R{sub E891BN} can underestimate the annual peak solar heat gain of a typical roof or pavement (slope {<=} 5:12 [23 ]) by as much as 89 W m{sup -2}, and underestimate its peak surface temperature by up to 5 K. Using R{sub E891BN} to characterize roofs in a building energy simulation can exaggerate the economic value N of annual cool roof net energy savings by as much as 23%. We define clear sky air mass one global horizontal (''AM1GH'') solar reflectance R{sub g,0}, a simple and easily measured property that more accurately predicts solar heat gain. R{sub g,0} predicts the annual peak solar heat gain of a roof or pavement to within 2 W m{sup -2}, and overestimates N by no more than 3%. R{sub g,0} is well suited to rating the solar reflectances of roofs, pavements and walls. We show in Part II that R{sub g,0} can be easily and accurately measured with a pyranometer, a solar spectrophotometer or version 6 of the Solar Spectrum Reflectometer. (author)

Measuring solar reflectance Part I: Defining a metric that accurately predicts solar heat gain

Energy Technology Data Exchange (ETDEWEB)

Levinson, Ronnen; Akbari, Hashem; Berdahl, Paul

2010-05-14

Solar reflectance can vary with the spectral and angular distributions of incident sunlight, which in turn depend on surface orientation, solar position and atmospheric conditions. A widely used solar reflectance metric based on the ASTM Standard E891 beam-normal solar spectral irradiance underestimates the solar heat gain of a spectrally selective 'cool colored' surface because this irradiance contains a greater fraction of near-infrared light than typically found in ordinary (unconcentrated) global sunlight. At mainland U.S. latitudes, this metric RE891BN can underestimate the annual peak solar heat gain of a typical roof or pavement (slope {le} 5:12 [23{sup o}]) by as much as 89 W m{sup -2}, and underestimate its peak surface temperature by up to 5 K. Using R{sub E891BN} to characterize roofs in a building energy simulation can exaggerate the economic value N of annual cool-roof net energy savings by as much as 23%. We define clear-sky air mass one global horizontal ('AM1GH') solar reflectance R{sub g,0}, a simple and easily measured property that more accurately predicts solar heat gain. R{sub g,0} predicts the annual peak solar heat gain of a roof or pavement to within 2 W m{sup -2}, and overestimates N by no more than 3%. R{sub g,0} is well suited to rating the solar reflectances of roofs, pavements and walls. We show in Part II that R{sub g,0} can be easily and accurately measured with a pyranometer, a solar spectrophotometer or version 6 of the Solar Spectrum Reflectometer.

Active solar heating industry development study

International Nuclear Information System (INIS)

1995-01-01

Despite the fact that solar water heating systems are technologically viable and commercially available, this Energy Technology Support Unit report shows that there is no established market in the United Kingdom. The Solar Trade Association (STA) has undertaken an Active Solar Heating Industry Development Study which is reported here. The data is derived from a questionnaire survey completed by companies, organizations and individuals operating within the industry. Information was also gathered from utility companies, and STAs elsewhere in Europe. Barriers which need to be overcome include lack of public awareness, especially in the construction industry, lack of capital investment and other financial disincentives, little or no government support, and lack of organization and quality monitoring and assurance within the industry itself. (UK)

Solar heating as a major source of energy for Australia

Energy Technology Data Exchange (ETDEWEB)

Morse, R. N.

1977-07-01

Solar energy can make its most effective contribution to Australian primary energy in the form of heat for industrial applications. About 50% of all end use energy is required as heat and it is estimated that 40% of this amounting to 1 EJ/a by 2000 could be supplied by solar heat generating systems. This would be 12% of estimated primary energy requirements by that time, and could help reduce the country's increasing dependence on imported oil. Energy self-sufficiency for Australia is possible, based on coal, solar energy and natural gas as primary energy sources. The reason for the present orientation towards residential solar water heaters is that there are many places where electric power for water heating costs between 2 and 4 cents per kWh which makes a solar water heater an attractive proposition. There is also a growing interest in the solar heating of swimming pools, mostly for private homes but also in larger installations for public and institutional pools. Industrial applications, on the other hand, are inhibited by the current low energy prices in Australia, which in some cases are around 0.13 cents/MJ (.47 cents/kWh). Industry, however, uses 40% of Australian primary energy, and represents by far the greatest potential for solar heat generating systems. Demonstration plants are being planned to obtain data on capital and running costs, and at the same time build up professional design and constructional skills in this area. The first demonstration solar industrial process heating system was commissioned in December 1976 and supplies portion of the heat requirements of a soft drink plant in conjunction with the existing oil fired boiler. Integrated solar/oil fired systems of this sort ensure continuous operation of the plant and over a year can result in significant oil savings.

Solar heating as a major source of energy for Australia

Energy Technology Data Exchange (ETDEWEB)

Morse, R.N.

1977-07-01

Solar energy can make its most effective contribution to Australian primary energy in the form of heat for industrial applications. About 50% of all end use energy is required as heat and it is estimated that 40% of this amounting to 1 EJ/a by 2000 could be supplied by solar heat generating systems. This would be 12% of estimated primary energy requirements by that time, and could help reduce the country's increasing dependence on imported oil. Energy self-sufficiency for Australia is possible, based on coal, solar energy and natural gas as primary energy sources. The reason for the present orientation towards residential solar water heaters is that there are many places where electric power for water heating costs between 2 and 4 cents per kWh which makes a solar water heater an attractive proposition. There is also a growing interest in the solar heating of swimming pools, mostly for private homes but also in larger installations for public and institutional pools. Industrial applications, on the other hand, are inhibited by the current low energy prices in Australia, which in some cases are around 0.13 cents/MJ (.47 cents/kWh). Industry, however, uses 40% of Australian primary energy, and represents by far the greatest potential for solar heat generating systems. Demonstration plants are being planned to obtain data on capital and running costs, and at the same time build up professional design and constructional skills in this area. The first demonstration solar industrial process heating system was commissioned in December 1976 and supplies portion of the heat requirements of a soft drink plant in conjunction with the existing oil fired boiler. Integrated solar/oil fired systems of this sort ensure continuous operation of the plant and over a year can result in significant oil savings.

Solar heating at the P. E. I. Ark

Energy Technology Data Exchange (ETDEWEB)

MacKay, K.T.

1979-01-01

Both active and passive solar heating systems are employed at the P.E.I. Ark. An active drain-down system, which stores heat in water located in 70,000 litre concrete tanks, supplies heat to the living area. Domestic hot water is heated by a thermosiphon drain-down solar system coupled to a wood cookstove. Environmental design of the Ark allows for maximum use of passive solar energy. The passive system supplies the majority of the heating load on sunny days, while wood stoves supply the back-up heat. The performance of the active system has required high maintenance because of problems in the mechanical and electrical systems. This, coupled with the high initial cost, has not made the system cost effective. The 178m/sup 2/ commercial greenhouse uses a hybrid system with both active and passive systems. The active system employs a fan to draw air through rock storage. The passive system employs the high thermal mass of the deep soil beds, a concrete slab, and most importantly, 53,200 litres of water in translucent tanks. These tanks are then used for fish rearing and are the basis for a solar hatchery. The greenhouse has performed very well, producing crops year round since 1976.

Thermo-economic design optimization of parabolic trough solar plants for industrial process heat applications with memetic algorithms

International Nuclear Information System (INIS)

Silva, R.; Berenguel, M.; Pérez, M.; Fernández-Garcia, A.

2014-01-01

Highlights: • A thermo-economic optimization of a parabolic-trough solar plant for industrial process heat applications is developed. • An analysis of the influence of economic cost functions on optimal design point location is presented. • A multi-objective optimization approach to the design routine is proposed. • A sensitivity analysis of the optimal point location to economic, operational, and ambient conditions is developed. • Design optimization of a parabolic trough plant for a reference industrial application is developed. - Abstract: A thermo-economic design optimization of a parabolic trough solar plant for industrial processes with memetic algorithms is developed. The design domain variables considered in the optimization routine are the number of collectors in series, number of collector rows, row spacing, and storage volume. Life cycle savings, levelized cost of energy, and payback time objective functions are compared to study the influence on optimal design point location. Furthermore a multi-objective optimization approach is proposed to analyze the design problem from a multi-economic criteria point of view. An extensive set of optimization cases are performed to estimate the influence of fuel price trend, plant location, demand profile, operation conditions, solar field orientation, and radiation uncertainty on optimal design. The results allow quantifying as thermo-economic design optimization based on short term criteria as the payback time leads to smaller plants with higher solar field efficiencies and smaller solar fractions, while the consideration of optimization criteria based on long term performance of the plants, as life cycle savings based optimization, leads to the reverse conclusion. The role of plant location and future evolution of gas prices in the thermo-economic performance of the solar plant has been also analyzed. Thermo-economic optimization of a parabolic trough solar plant design for the reference industrial

Solar heating and cooling demonstration project at the Florida solar energy center

Science.gov (United States)

1980-01-01

The retrofitted solar heating and cooling system installed at the Florida Solar Energy Center is described. The system was designed to supply approximately 70 percent of the annual cooling and 100 percent of the heating load. The project provides unique high temperature, nonimaging, nontracking, evacuated tube collectors. The design of the system was kept simple and employs five hydronic loops. They are energy collection, chilled water production, space cooling, space heating and energy rejection. Information is provided on the system's acceptance test results operation, controls, hardware and installation, including detailed drawings.

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

Science.gov (United States)

Davis, E. S.

1975-01-01

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

Flat plate solar air heater with latent heat storage

Science.gov (United States)

Touati, B.; Kerroumi, N.; Virgone, J.

2017-02-01

Our work contains two parts, first is an experimental study of the solar air heater with a simple flow and forced convection, we can use thatlaste oneit in many engineering's sectors as solardrying, space heating in particular. The second part is a numerical study with ansys fluent 15 of the storage of part of this solar thermal energy produced,using latent heat by using phase change materials (PCM). In the experimental parts, we realize and tested our solar air heater in URER.MS ADRAR, locate in southwest Algeria. Where we measured the solarradiation, ambient temperature, air flow, thetemperature of the absorber, glasses and the outlet temperature of the solar air heater from the Sunrise to the sunset. In the second part, we added a PCM at outlet part of the solar air heater. This PCM store a part of the energy produced in the day to be used in peak period at evening by using the latent heat where the PCMs present a grateful storagesystem.A numerical study of the fusion or also named the charging of the PCM using ANSYS Fluent 15, this code use the method of enthalpies to solve the fusion and solidification formulations. Furthermore, to improve the conjugate heat transfer between the heat transfer fluid (Air heated in solar plate air heater) and the PCM, we simulate the effect of adding fins to our geometry. Also, four user define are write in C code to describe the thermophysicalpropriety of the PCM, and the inlet temperature of our geometry which is the temperature at the outflow of the solar heater.

Heat Transfer Phenomena in Concentrating Solar Power Systems.

Energy Technology Data Exchange (ETDEWEB)

Armijo, Kenneth Miguel; Shinde, Subhash L.

2016-11-01

Concentrating solar power (CSP) utilizes solar thermal energy to drive a thermal power cycle for the generation of electricity. CSP systems are facilitated as large, centralized power plants , such as power towers and trough systems, to take advantage of ec onomies of scale through dispatchable thermal energy storage, which is a principle advantage over other energy generation systems . Additionally, the combination of large solar concentration ratios with high solar conversion efficiencies provides a strong o pportunity of employment of specific power cycles such as the Brayton gas cycle that utilizes super critical fluids such as supercritical carbon dioxide (s CO 2 ) , compared to other sola r - fossil hybrid power plants. A comprehensive thermal - fluids examination is provided by this work of various heat transfer phenomena evident in CSP technologies. These include sub - systems and heat transfer fundamental phenomena evident within CSP systems , which include s receivers, heat transfer fluids (HTFs), thermal storage me dia and system designs , thermodynamic power block systems/components, as well as high - temperature materials. This work provides literature reviews, trade studies, and phenomenological comparisons of heat transfer media (HTM) and components and systems, all for promotion of high performance and efficient CSP systems. In addition, f urther investigations are also conducted that provide advanced heat transfer modeling approaches for gas - particle receiver systems , as well as performance/efficiency enhancement re commendations, particularly for solarized supercritical power systems .

Solar collectors and heat pump: Market review and preliminary simulation results

International Nuclear Information System (INIS)

Tepe, Rainer; Roennelid, Mats

2002-01-01

Heating systems that combine solar collectors and a heat pump available on the market in Sweden have been studied. A majority of the systems found combine the solar collectors with a ground source heat pump. The technology for combining the collectors and the heat pump does however vary considerably. In the most simple systems, the collectors heat the return water from the heat pump, i.e. the collectors are used for raising the temperature in the boreholes for the heat pump. In the advanced systems, the solar heat is used for tap water, space heating and for raising the temperature of the heat pump's evaporator. There exist only very few comparative evaluations of the contributions from solar collectors in heat pump systems, and there is a need for finding the potential for this technique. In the present study, results are reported from preliminary simulations of solar collectors and ground source heat pumps installed in one-family houses. Simulations are made for two heating loads: 8,650 and 16,500 kWh/year resp., and a hot water load of 3,000 kWh/year. The study shows that: the temperature of the borehole decreases when solar collectors are not used (about 1.2 deg C in three years): 8 m 2 glazed solar collectors used for hot water production can reduce the electricity consumption with up to 13%, with best results in the house with low heating load: 50 m 2 unglazed solar collectors coupled to the evaporator or the borehole can give reductions of up to 14%, largest reduction in the house with high heating load, where the heat extraction from the borehole is large: the unglazed collectors have the highest economic potential, and can be cost effective for houses with high heating load: the simulations do not include a thorough system optimization, better results can be expected from continued optimization work

Solar heat gain through vertical cylindrical glass

Energy Technology Data Exchange (ETDEWEB)

Kassem, M.A.; Kaseb, S.; El-Refaie, M.F. [Cairo Univ., Mechanical Power Engineering Dept., Cairo (Egypt)

1999-10-01

Spaces with nonplanar glazed envelopes are frequently encountered in contemporary buildings. Such spaces represent a problem when calculating the solar heat gain in the course of estimating the cooling or heating load; and hence, sizing of cooling or heating systems. The calculation, using the information currently available in the literature, is tedious and/or approximate. In the present work, the computational procedure for evaluating the solar heat gain to a space having a vertical cylindrical glass envelope is established, and, a computer program is coded to carry out the necessary computations and yield the results in a detailed usable form. The program is versatile and allows for the arbitrary variation of all pertinent parameters. (Author)

Solar heat gain through vertical cylindrical glass

International Nuclear Information System (INIS)

Kassem, M.A.; Kaseb, S.; El-Refaie, M.F.

1999-01-01

Spaces with nonplanar glazed envelopes are frequently encountered in contemporary buildings. Such spaces represent a problem when calculating the solar heat gain in the course of estimating the cooling or heating load; and hence, sizing of cooling or heating systems. The calculation, using the information currently available in the literature, is tedious and/or approximate. In the present work, the computational procedure for evaluating the solar heat gain to a space having a vertical cylindrical glass envelope is established, and, a computer program is coded to carry out the necessary computations and yield the results in a detailed usable form. The program is versatile and allows for the arbitrary variation of all pertinent parameters. (Author)

Solar heat gain through vertical cylindrical glass

Energy Technology Data Exchange (ETDEWEB)

Kassem, M.A.; Kaseb, S.; El-Refaie, M.F. [Cairo Univ., Mechanical Power Engineering Dept., Cairo (Egypt)

1999-07-01

Spaces with nonplanar glazed envelopes are frequently encountered in contemporary buildings. Such spaces represent a problem when calculating the solar heat gain in the course of estimating the cooling or heating load; and hence, sizing of cooling or heating systems. The calculation, using the information currently available in the literature, is tedious and/or approximate. In the present work, the computational procedure for evaluating the solar heat gain to a space having a vertical cylindrical glass envelope is established, and, a computer program is coded to carry out the necessary computations and yield the results in a detailed usable form. The program is versatile and allows for the arbitrary variation of all pertinent parameters. (Author)

Combined system of solar heating and cooling using heat pump

International Nuclear Information System (INIS)

Zakhidov, R.A.; Anarbaev, A.I.

2014-01-01

The heating and cooling systems of apartment buildings based on combined solar heat-pump equipment has been considered and the procedure of calculating its parameters has been worked out. A technical-economic analysis has been performed and compared with the boiler-setting version. (author)

Central solar heating plants with seasonal storage

Energy Technology Data Exchange (ETDEWEB)

Chuard, D; Hadorn, J C; Van Gilst, J; Aranovitch, E; Hardacre, A G; Ofverholm, E [eds.

1982-09-14

On May 9, 1979, the Federal Department for Buildings released instructions concerning the use of alternative energies. The federal energy policy is to be as much as possible independent on oil imports. The canton Fribourg decided to equip the new maintenance and service center for the national high-road N12, with alternative energy, resources, and to apply new concepts with respect to passive and active solar energy. The project uses active solar energy with an earth-storage and heat pump. A conventional oil-heating system provides energy for peak-loads and can be operated in stand-by. A delay in the construction of the earth storage sub system was requested because it was intended to optimize the system with respect to the solar sub system, and heat pump sub system. The design work was done by SORANE which also is the coordinator for Switzerland in the I.E.A. Task VII. However, the preplanning of the project started in 1978 before the I.E.A. Task VII started. As a consequence, many design parameters were determined before 1980. The optimization of the solar collector, heat-pump etc. sub system was performed by a simulation approach developed by SORANE. The Vaulruz service center has been commissioned during the winter 1981/82.

Antireflection coating design for series interconnected multi-junction solar cells

International Nuclear Information System (INIS)

Aiken, Daniel J.

1999-01-01

AR coating design for multi-junction solar cells can be more challenging than in the single junction case. Reasons for this are discussed. Analytical expressions used to optimize AR coatings for single junction solar cells are extended for use in monolithic, series interconnected multi-junction solar cell AR coating design. The result is an analytical expression which relates the solar cell performance (through J(sub SC)) directly to the AR coating design through the device reflectance. It is also illustrated how AR coating design can be used to provide an additional degree of freedom for current matching multi-junction devices

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

Energy Technology Data Exchange (ETDEWEB)

1980-06-01

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

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

DEFF Research Database (Denmark)

Tian, Zhiyong; Perers, Bengt; Furbo, Simon

2017-01-01

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

Compact solar heating systems - back on the way up

International Nuclear Information System (INIS)

Lainsecq, M. de

2001-01-01

This article discusses the upward trend being noted in the installation of compact solar heating systems in Switzerland. The contribution of these complete, easy-to-install systems to the increasing number of solar heating units on the market is discussed and the role played by the Solar Collector and Systems Testing Facility at the Institute of Solar Technology in Rapperswil, Switzerland, is emphasised. One of this institute's important publications is a list of certified compact solar heating systems. The high technical standards of the systems and the current price situation are discussed. The article is rounded off by an interview with a four-person family on their motivation to install such a hot-water system and their experience with its operation. Finally, future trends in the area are discussed

The UK solar water heating industry: a period of development and growth

International Nuclear Information System (INIS)

Blower, John

2001-01-01

This 2001 edition of the guide to UK renewable energy companies examines the solar water heating sector in the UK and presents an illustration of the layout of a typical solar water heating system. The rising demand for solar water heating and growth in sales especially in the export market are noted. Developments within the UK solar water heating manufacturing industry are considered, and details are given of design and development in innovative policy infrastructure, and the SHINE 21 project supported by the EU's ADAPT programme and the UK Department of Trade and Industry involving collaboration between the solar water heating and plumbing industries. Developments in the new build sectors including in-roof solar collector products and the increasing number of solar water heating systems installed in UK houses are discussed along with the promising future for the market

Maximum-power-point tracking control of solar heating system

KAUST Repository

Huang, Bin-Juine

2012-11-01

The present study developed a maximum-power point tracking control (MPPT) technology for solar heating system to minimize the pumping power consumption at an optimal heat collection. The net solar energy gain Q net (=Q s-W p/η e) was experimentally found to be the cost function for MPPT with maximum point. The feedback tracking control system was developed to track the optimal Q net (denoted Q max). A tracking filter which was derived from the thermal analytical model of the solar heating system was used to determine the instantaneous tracking target Q max(t). The system transfer-function model of solar heating system was also derived experimentally using a step response test and used in the design of tracking feedback control system. The PI controller was designed for a tracking target Q max(t) with a quadratic time function. The MPPT control system was implemented using a microprocessor-based controller and the test results show good tracking performance with small tracking errors. It is seen that the average mass flow rate for the specific test periods in five different days is between 18.1 and 22.9kg/min with average pumping power between 77 and 140W, which is greatly reduced as compared to the standard flow rate at 31kg/min and pumping power 450W which is based on the flow rate 0.02kg/sm 2 defined in the ANSI/ASHRAE 93-1986 Standard and the total collector area 25.9m 2. The average net solar heat collected Q net is between 8.62 and 14.1kW depending on weather condition. The MPPT control of solar heating system has been verified to be able to minimize the pumping energy consumption with optimal solar heat collection. © 2012 Elsevier Ltd.

Solar Water Heating with Low-Cost Plastic Systems (Brochure)

Energy Technology Data Exchange (ETDEWEB)

2012-01-01

Newly developed solar water heating technology can help Federal agencies cost effectively meet the EISA requirements for solar water heating in new construction and major renovations. This document provides design considerations, application, economics, and maintenance information and resources.

Bacterial growth in solar heating prepared and traditional tanks

International Nuclear Information System (INIS)

Bagh, L.K.

2000-01-01

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

Near-term viability of solar heat applications for the federal sector

Science.gov (United States)

Williams, T. A.

1991-12-01

Solar thermal technologies are capable of providing heat across a wide range of temperatures, making them potentially attractive for meeting energy requirements for industrial process heat applications and institutional heating. The energy savings that could be realized by solar thermal heat are quite large, potentially several quads annually. Although technologies for delivering heat at temperatures above 100 C currently exist within industry, only a fairly small number of commercial systems have been installed to date. The objective of this paper is to investigate and discuss the prospects for near term solar heat sales to federal facilities as a mechanism for providing an early market niche to the aid the widespread development and implementation of the technology. The specific technical focus is on mid-temperature (100 to 350 C) heat demands that could be met with parabolic trough systems. Federal facilities have several features relative to private industry that may make them attractive for solar heat applications relative to other sectors. Key features are specific policy mandates for conserving energy, a long term planning horizon with well defined decision criteria, and prescribed economic return criteria for conservation and solar investments that are generally less stringent than the investment criteria used by private industry. Federal facilities also have specific difficulties in the sale of solar heat technologies that are different from those of other sectors, and strategies to mitigate these difficulties will be important. For the baseline scenario developed in this paper, the solar heat application was economically competitive with heat provided by natural gas. The system levelized energy cost was $5.9/MBtu for the solar heat case, compared to $6.8/MBtu for the life cycle fuel cost of a natural gas case. A third-party ownership would also be attractive to federal users, since it would guarantee energy savings and would not need initial federal funds.

Federal technology alert. Parabolic-trough solar water heating

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-04-01

Parabolic-trough solar water heating is a well-proven renewable energy technology with considerable potential for application at Federal facilities. For the US, parabolic-trough water-heating systems are most cost effective in the Southwest where direct solar radiation is high. Jails, hospitals, barracks, and other facilities that consistently use large volumes of hot water are particularly good candidates, as are facilities with central plants for district heating. As with any renewable energy or energy efficiency technology requiring significant initial capital investment, the primary condition that will make a parabolic-trough system economically viable is if it is replacing expensive conventional water heating. In combination with absorption cooling systems, parabolic-trough collectors can also be used for air-conditioning. Industrial Solar Technology (IST) of Golden, Colorado, is the sole current manufacturer of parabolic-trough solar water heating systems. IST has an Indefinite Delivery/Indefinite Quantity (IDIQ) contract with the Federal Energy Management Program (FEMP) of the US Department of Energy (DOE) to finance and install parabolic-trough solar water heating on an Energy Savings Performance Contract (ESPC) basis for any Federal facility that requests it and for which it proves viable. For an ESPC project, the facility does not pay for design, capital equipment, or installation. Instead, it pays only for guaranteed energy savings. Preparing and implementing delivery or task orders against the IDIQ is much simpler than the standard procurement process. This Federal Technology Alert (FTA) of the New Technology Demonstration Program is one of a series of guides to renewable energy and new energy-efficient technologies.

Solar and seasonal dependence of ion frictional heating

Directory of Open Access Journals (Sweden)

J. A. Davies

1999-05-01

Full Text Available Ion frictional heating constitutes one of the principal mechanisms whereby energy, originating in the solar wind, is deposited into the Earth's ionosphere and ultimately the neutral atmosphere. Common programme observations by the EISCAT UHF radar system, spanning the years 1984 to 1995, provide the basis for a comprehensive statistical study of ion frictional heating, results of which are documented in this and a previous paper by the authors. In the present work, the authors demonstrate the solar and seasonal dependence of the universal time distribution of frictional heating, and explain these results with reference to corresponding dependences of the ion velocity. Although EISCAT observes a significant increase in the occurrence of enhanced ion velocities associated with increased solar activity, the latter characterised according to the prevailing 10.7 cm solar flux, this is not reflected to such an extent in the occurrence of frictional heating. It is suggested that this is a consequence of the decreased neutral atmosphere response times associated with active solar conditions, resulting from the higher ionospheric plasma densities present. Seasonal effects on the diurnal distribution of ion frictional heating are well explained by corresponding variations in ionospheric convection, the latter principally a result of geometrical factors. It is noted that, over the entire dataset, the variations in the unperturbed F-region ion temperature, required to implement the identification criterion for ion heating, are highly correlated with model values of thermospheric temperature.Keywords. Ionosphere (auroral ionosphere; ionosphere-atmosphere interactions; plasma temperature and density

Performance study of heat-pipe solar photovoltaic/thermal heat pump system

International Nuclear Information System (INIS)

Chen, Hongbing; Zhang, Lei; Jie, Pengfei; Xiong, Yaxuan; Xu, Peng; Zhai, Huixing

2017-01-01

Highlights: • The testing device of HPS PV/T heat pump system was established by a finished product of PV panel. • A detailed mathematical model of heat pump was established to investigate the performance of each component. • The dynamic and static method was combined to solve the mathematical model of HPS PV/T heat pump system. • The HPS PV/T heat pump system was optimized by the mathematical model. • The influence of six factors on the performance of HPS PV/T heat pump system was analyzed. - Abstract: A heat-pipe solar (HPS) photovoltaic/thermal (PV/T) heat pump system, combining HPS PV/T collector with heat pump, is proposed in this paper. The HPS PV/T collector integrates heat pipes with PV panel, which can simultaneously generate electricity and thermal energy. The extracted heat from HPS PV/T collector can be used by heat pump, and then the photoelectric conversion efficiency is substantially improved because of the low temperature of PV cells. A mathematical model of the system is established in this paper. The model consists of a dynamic distributed parameter model of the HPS PV/T collection system and a quasi-steady state distributed parameter model of the heat pump. The mathematical model is validated by testing data, and the dynamic performance of the HPS PV/T heat pump system is discussed based on the validated model. Using the mathematical model, a reasonable accuracy in predicting the system’s dynamic performance with a relative error within ±15.0% can be obtained. The capacity of heat pump and the number of HPS collectors are optimized to improve the system performance based on the mathematical model. Six working modes are proposed and discussed to investigate the effect of solar radiation, ambient temperature, supply water temperature in condenser, PV packing factor, heat pipe pitch and PV backboard absorptivity on system performance by the validated model. It is found that the increase of solar radiation, ambient temperature and PV

Experimental study of a solar-assisted ground-coupled heat pump system with solar seasonal thermal storage in severe cold areas

Energy Technology Data Exchange (ETDEWEB)

Wang, Xiao; Zheng, Maoyu; Zhang, Wenyong; Zhang, Shu; Yang, Tao [School of Municipal and Environmental Engineering, Harbin Institute of Technology, NO 202 Haihe Road, Harbin, Hei Longjiang 150090 (China)

2010-11-15

This paper presents the experimental study of a solar-assisted ground-coupled heat pump system (SAGCHPS) with solar seasonal thermal storage installed in a detached house in Harbin. The solar seasonal thermal storage was conducted throughout the non-heating seasons. In summer, the soil was used as the heat sink to cool the building directly. In winter, the solar energy was used as a priority, and the building was heated by a ground-coupled heat pump (GCHP) and solar collectors alternately. The results show that the system can meet the heating-cooling energy needs of the building. In the heating mode, the heat directly supplied by solar collectors accounted for 49.7% of the total heating output, and the average coefficient of performance (COP) of the heat pump and the system were 4.29 and 6.55, respectively. In the cooling mode, the COP of the system reached 21.35, as the heat pump was not necessary to be started. After a year of operation, the heat extracted from the soil by the heat pump accounted for 75.5% of the heat stored by solar seasonal thermal storage. The excess heat raised the soil temperature to a higher level, which was favorable for increasing the COP of the heat pump. (author)

Available online Efficiency potential of indirectly heated solar reforming with different types of solar air receivers

International Nuclear Information System (INIS)

Storch, Henrik von; Roeb, Martin; Stadler, Hannes; Sattler, Christian; Hoffschmidt, Bernhard

2016-01-01

Highlights: • A process for indirectly heated solar reforming of natural gas with air as heat transfer fluid is proposed. • Different solar receivers are modeled and implemented into the reforming process. • The overall efficiency of the process with different solar receivers is determined. • Optimum solar receiver characteristics for application in a solar reforming process are determined. - Abstract: In solar reforming, the heating value of natural gas is increased by utilization of concentrated solar radiation. Hence, it is a process for storing solar energy in a stable and transportable form that also permits further conversion into liquid fuels like methanol. This process has the potential to significantly decrease the natural gas consumption and the associated CO_2-emissions of methanol production with only few open questions to be addressed prior to commercialization. In the medium and long term, it has the potential to generate methanol as an environmentally friendly fuel for both transport as well as flexible electricity production in combined cycle gas turbines, when biogas is used as reactant. In a previous study the high potential of indirectly heated solar reforming with solar air receivers was shown; however, the efficiency is limited when using state of the art open volumetric receivers. Therefore, different types of air receivers are implemented into an indirectly heated solar reforming process and the overall efficiency potential is assessed in the present study. The implemented receivers are an open volumetric cavity receiver, a closed volumetric cavity receiver and a tubular cavity receiver. The open volumetric cavity receiver and tubular cavity receiver achieve the best results due to their capability of operating efficiently at temperatures well above 700 °C. For these receivers peak efficiencies up to 29% and 27% respectively are predicted. As the utilization of an open volumetric cavity receiver constitutes an open heat transfer

NUMERICAL ANALYSIS OF HEAT STORAGE OF SOLAR HEAT IN FLOOR CONSTRUCTION

DEFF Research Database (Denmark)

Weitzmann, Peter; Holck, Ole; Svendsen, Svend

2003-01-01

with the highest energy con-sumption. The reduction depends on the solar collector area, distribution of the insulation thickness, heat-ing demand and control strategy, but not on pipe spacing and layer thickness and material. Finally, it is shown that the system can also be used for comfort heating of tiled...

Air and liquid solar heating system with heatpump, VP-SOL

DEFF Research Database (Denmark)

Kristiansen, Finn Harken; Jensen, Søren Østergaard

1998-01-01

For more than a year, measurements have been made on an air/fluid solar heating system with heat pump. The annual thermal performance of the system has been found and compared with simulations carried out by means of the simulation program KVIKSOL.The heat loss of the hot water tank is calculated...... be changed in such a way that the air is drawn through the solar collectors when the air temperature of the solar collectors is e.g. 5 K higher than the open air temperature.It has turned out that under the given conditions the system (compared to the simulations) performs as expected.If the heat pump...... is changed in such a way that it only heats the tank to max. 55ºC the net utilized solar energy of the system can be increased by approximately 30%.All things considered, it is estimated that the net utilized solar energy of the system can be increased by about 40% on condition that the proposed changes...

Initial operation of a solar heating and cooling system in a full-scale solar building test facility

Science.gov (United States)

Knoll, R. H.; Miao, D.; Hamlet, I. L.; Jensen, R. N.

1976-01-01

The Solar Building Test Facility (SBTF) located at Hampton, Virginia became operational in early summer of 1976. This facility is a joint effort by NASA-Lewis and NASA-Langley to advance the technology for heating and cooling of office buildings with solar energy. Its purposes are to (1) test system components which include high-performing collectors, (2) test performance of complete solar heating and cooling system, (3) investigate component interactions and (4) investigate durability, maintenance and reliability of components. The SBTF consists of a 50,000 square foot office building modified to accept solar heated water for operation of an absorption air conditioner and for the baseboard heating system. A 12,666 square foot solar collector field with a 30,000 gallon storage tank provides the solar heated water. A description of the system and the collectors selected is given here, along with the objectives, test approach, expected system performance and some preliminary results.

Heat of Fusion Storage with High Solar Fraction for Solar Low Energy Buildings

DEFF Research Database (Denmark)

Schultz, Jørgen Munthe; Furbo, Simon

2006-01-01

to achieve 100% coverage of space heating and domestic hot water in a low energy house in a Danish climate with a solar heating system with 36 m² flat plate solar collector and approximately 10 m³ storage with sodium acetate. A traditional water storage solution aiming at 100% coverage will require a storage...... of the storage to cool down below the melting point without solidification preserving the heat of fusion energy. If the supercooled storage reaches the surrounding temperature no heat loss will take place until the supercooled salt is activated. The investigation shows that this concept makes it possible...

Combined use of solar heat and cogeneration - a perspective for district heating?; Kombinierter Einsatz von solarer Waerme und Kraft-Waerme-Kopplung - eine Perspektive fuer die Nahwaerme?

Energy Technology Data Exchange (ETDEWEB)

Entress, J. [Deutsches Zentrum fuer Luft- und Raumfahrt (DLR), Stuttgart (Germany). Abt. Systemanalyse und Technikbewertung; Steinborn, F. [Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung Baden-Wuerttemberg (ZSW), Stuttgart (Germany). Fachgebiet Systemanalyse

1998-02-01

With Cogeneration of Heat and Power (CHP), climate-endangering CO{sub 2}-emissions can be reduced singificantly. The heat produced can be delivered at prices comparable to those of conventionally produced heat. With solar district heating, yet higher CO{sub 2}-savings are possible but at higher cost. Promising is a combination of CHP and solar district heating: The heat storage of the solar system can be used to level out heat demand, leading to smooth CHP operation, while heat generated by CHP can be used to substitute for low irradiation during the winter period. However, calculations together with simulation and optimization indicate that combining CHP and solar district heating is not the optimal solution in all cases. (orig.) [Deutsch] Der Einsatz von Blockheizkraftwerken (BHKW) kann zu einer deutlichen Reduzierung der klimagefaehrdenden CO{sub 2}-Emissionen beitragen. Dabei kann die ausgekoppelte Waerme etwa zum gleichen Preis wie konventionell erzeugte Waerme abgegeben werden. Hoehere CO{sub 2}-Einsparungen lassen sich hingegen mit solarer Nahwaerme erzielen, allerdings zu hoeheren Kosten. Eine Kombination dieser beiden Waermetechniken verspricht Vorteile: Einerseits kann der Waermespeicher des Solarsystems auch zum Ausgleich von Lastspitzen beim Betrieb des BHKW`s genutzt werden. Andererseits kann die waehrend der einstrahlungsarmen Wintermonate fehlende solare Waerme durch das BHKW erzeugt werden. Detaillierte Simulations- und Optimierungsrechnungen zeigen jedoch, dass eine Kombination dieser Waermetechniken nicht immer empfehlenswert ist. (orig.)

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

Science.gov (United States)

1980-01-01

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

Performance analysis of a solar still coupled with evacuated heat pipes

Science.gov (United States)

Pramod, B. V. N.; Prudhvi Raj, J.; Krishnan, S. S. Hari; Kotebavi, Vinod

2018-02-01

In developing countries the need for better quality drinking water is increasing steadily. We can overcome this need by using solar energy for desalination purpose. This process includes fabrication and analysis of a pyramid type solar still coupled with evacuated heat pipes. This experiment using evacuated heat pipes are carried in mainly three modes namely 1) Still alone 2) Using heat pipe with evacuated tubes 3)Using evacuated heat pipe. For this work single basin pyramid type solar still with 1m2 basin area is fabricated. Black stones and Black paint are utilised in solar still to increase evaporation rate of water in basin. The heat pipe’s evaporator section is placed inside evacuated tube and the heat pipe’s condenser section is connected directly to the pyramid type solar still’s lower portion. The output of distillate water from still with evacuated heat pipe is found to be 40% more than the still using only evacuated tubes.

Interactive Multi-Instrument Database of Solar Flares

Science.gov (United States)

Ranjan, Shubha S.; Spaulding, Ryan; Deardorff, Donald G.

2018-01-01

The fundamental motivation of the project is that the scientific output of solar research can be greatly enhanced by better exploitation of the existing solar/heliosphere space-data products jointly with ground-based observations. Our primary focus is on developing a specific innovative methodology based on recent advances in "big data" intelligent databases applied to the growing amount of high-spatial and multi-wavelength resolution, high-cadence data from NASA's missions and supporting ground-based observatories. Our flare database is not simply a manually searchable time-based catalog of events or list of web links pointing to data. It is a preprocessed metadata repository enabling fast search and automatic identification of all recorded flares sharing a specifiable set of characteristics, features, and parameters. The result is a new and unique database of solar flares and data search and classification tools for the Heliophysics community, enabling multi-instrument/multi-wavelength investigations of flare physics and supporting further development of flare-prediction methodologies.

Test bench HEATREC for heat loss measurement on solar receiver tubes

Science.gov (United States)

Márquez, José M.; López-Martín, Rafael; Valenzuela, Loreto; Zarza, Eduardo

2016-05-01

In Solar Thermal Electricity (STE) plants the thermal energy of solar radiation is absorbed by solar receiver tubes (HCEs) and it is transferred to a heat transfer fluid. Therefore, heat losses of receiver tubes have a direct influence on STE plants efficiency. A new test bench called HEATREC has been developed by Plataforma Solar de Almería (PSA) in order to determinate the heat losses of receiver tubes under laboratory conditions. The innovation of this test bench consists in the possibility to determine heat losses under controlled vacuum.

Solar thermal heating and cooling. A bibliography with abstracts

Science.gov (United States)

Arenson, M.

1979-01-01

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

Multi-spacecraft observations of solar hard X-ray bursts

International Nuclear Information System (INIS)

Kane, S.R.

1981-01-01

The role of multi-spacecraft observations in solar flare research is examined from the point of view of solar hard X-ray bursts and their implications with respect to models of the impulsive phase. Multi-spacecraft measurements provide a stereoscopic view of the flare region, and hence represent the only direct method of measuring directivity of X-rays. In absence of hard X-ray imaging instruments with high spatial and temporal resolution, multi-spacecraft measurements provide the only means of determining the radial (vertical) structure of the hard X-ray source. This potential of the multi-spacecraft observations is illustrated with an analysis of the presently available observations of solar hard X-ray bursts made simultaneously by two or more of the following spacecraft: International Sun Earth Explorer-3 (ISEE-3), Pioneer Venus Orbiter (PVO), Helios-B and High Energy Astrophysical Observatory-A (HEAO-A). In particular, some conclusions have been drawn about the spatial structure and directivity of 50-100 keV X-rays from impulsive flares. Desirable features of future multi-spacecraft missions are briefly discussed followed by a short description of the hard X-ray experiment on the International Solar Polar Mission which has been planned specifically for multi-spacecraft observations of the Sun. (orig.)

Interaction of regulation and innovation: Solar air heating collectors

OpenAIRE

Kramer, K.

2012-01-01

Solar Air Heating Collectors have still a very small share of 0.8% of the nominal installed capacity in the solar heating and cooling market (151.7 GWth) [1]. Although constituting a niche market, the potential of those kind of collectors to provide heat for industrial processes, processing food, room heating, air preheating, drying processes or air conditioning could be significant. However, the technical potentials of the various technological solutions are not easy to compare. Such a compa...

A model to predict solar heat gains to outside wine tanks

Energy Technology Data Exchange (ETDEWEB)

Delves, T.; Weedon, M.; Louis, J. [Charles Sturt Univ., Wagga Wagga, NSW (Australia). National Wine and Grape Industry Centre

2006-07-01

Although there are many software and simulation tools for calculating solar heat gains to residential and commercial buildings, little information is available to predict the heating effect of products stored in outdoor facilities. In older wineries where wine is stored outdoors in stainless steel tanks, solar heat gains can result in unwanted warming of the wine. This not only ruins the wine quality, but places an additional load on the winery refrigeration system. In this study, experiments were performed to determine the effect of solar radiation and ambient conditions on the heating of wine stored in outside tanks. Trials were conducted on a 25 kL outdoor stainless steel tank at Rutherglen, Australia. In order to incorporate the effect of shading from adjacent tanks, trials were also conducted at Wagga Wagga, Australia, on a group of tanks where mutual shading was present. Each tank was fitted with sensors to study the effect of morning, afternoon and mid-day shading. A mathematical model was developed to predict the amount of solar heat load received by the tank. The model considered the effect of seasonal variations in radiation intensity, day length and sun angle. The model incorporated the size, spacing and orientation of the tanks as well as solar considerations such as time of year and latitude. This paper also presented background information on the solar radiation received by the earth. Solar radiation comprises direct radiation and diffuse radiation. Direct radiation refers to direct sunlight, travelling in parallel rays from the sun, while diffuse radiation refers to radiation which has been scattered by the atmosphere. In most cases, direct radiation is dominant, but both radiations are considered when calculating solar energy gains. The solar heating of the 25 kL tank of wine was calculated by isolating the solar heating from other heat flows. Fermentation was complete and no refrigeration was applied to the tank during the 5 days of the trial. Only

A review of large-scale solar heating systems in Europe

International Nuclear Information System (INIS)

Fisch, M.N.; Guigas, M.; Dalenback, J.O.

1998-01-01

Large-scale solar applications benefit from the effect of scale. Compared to small solar domestic hot water (DHW) systems for single-family houses, the solar heat cost can be cut at least in third. The most interesting projects for replacing fossil fuels and the reduction of CO 2 -emissions are solar systems with seasonal storage in combination with gas or biomass boilers. In the framework of the EU-APAS project Large-scale Solar Heating Systems, thirteen existing plants in six European countries have been evaluated. lie yearly solar gains of the systems are between 300 and 550 kWh per m 2 collector area. The investment cost of solar plants with short-term storage varies from 300 up to 600 ECU per m 2 . Systems with seasonal storage show investment costs twice as high. Results of studies concerning the market potential for solar heating plants, taking new collector concepts and industrial production into account, are presented. Site specific studies and predesign of large-scale solar heating plants in six European countries for housing developments show a 50% cost reduction compared to existing projects. The cost-benefit-ratio for the planned systems with long-term storage is between 0.7 and 1.5 ECU per kWh per year. (author)

Integrating Solar Heating into an Air Handling Unit to Minimize Energy Consumption

OpenAIRE

Wilson, Scott A

2010-01-01

The purpose of this project was to test a method of integrating solar heating with a small commercial air handling unit (AHU). In order to accomplish this a heat exchanger was placed in the reheat position of the AHU and piped to the solar heating system. This heat exchanger is used to supplement or replace the existing electric reheat. This method was chosen for its ability to utilize solar energy on a more year round basis when compared to a traditional heating system. It allows solar h...

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

Science.gov (United States)

1980-01-01

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

Numerical characterisation of one-step and three-step solar air heating collectors used for cocoa bean solar drying.

Science.gov (United States)

Orbegoso, Elder Mendoza; Saavedra, Rafael; Marcelo, Daniel; La Madrid, Raúl

2017-12-01

In the northern coastal and jungle areas of Peru, cocoa beans are dried using artisan methods, such as direct exposure to sunlight. This traditional process is time intensive, leading to a reduction in productivity and, therefore, delays in delivery times. The present study was intended to numerically characterise the thermal behaviour of three configurations of solar air heating collectors in order to determine which demonstrated the best thermal performance under several controlled operating conditions. For this purpose, a computational fluid dynamics model was developed to describe the simultaneous convective and radiative heat transfer phenomena under several operation conditions. The constructed computational fluid dynamics model was firstly validated through comparison with the data measurements of a one-step solar air heating collector. We then simulated two further three-step solar air heating collectors in order to identify which demonstrated the best thermal performance in terms of outlet air temperature and thermal efficiency. The numerical results show that under the same solar irradiation area of exposition and operating conditions, the three-step solar air heating collector with the collector plate mounted between the second and third channels was 67% more thermally efficient compared to the one-step solar air heating collector. This is because the air exposition with the surface of the collector plate for the three-step solar air heating collector former device was twice than the one-step solar air heating collector. Copyright © 2017 Elsevier Ltd. All rights reserved.

Numerical simulation of a heat pump assisted regenerative solar still with PCM heat storage for cold climates of Kazakhstan

Directory of Open Access Journals (Sweden)

Shakir Yessen

2017-01-01

Full Text Available A numerical model has been proposed in this work for predicting the energy performances of the heat pump assisted regenerative solar still with phase changing material heat storage under Kazakhstan climates. The numerical model is based on energy and mass balance. A new regenerative heat pump configuration with phase changing material heat storage is proposed to improve the performance. A comparison of results has been made between the conventional solar still and heat pump assisted regenerative solar still with phase changing material. The numerical simulation was performed for wide range of ambient temperatures between -30 and 30°C with wide range of solar intensities between 100 and 900 W/m2. The numerical simulation results showed that heat pump assisted regenerative solar still is more energy efficient and produce better yield when compared to the conventional simple solar still. The influences of solar intensity, ambient temperature, different phase changing materials, heat pump operating temperatures are discussed. The predicted values were found to be in good agreement with experimental results reported in literature.

Multi-shelf domestic solar dryer

International Nuclear Information System (INIS)

Singh, Parm Pal; Singh, Sukhmeet; Dhaliwal, S.S.

2006-01-01

The solar dryer described in this paper can be used for drying various products at home under hygienic conditions with the self guarantee of adulteration free product. This solar dryer is of multi-shelf design, consisting of three perforated trays arranged one above the other. The drying air flows through the product by natural circulation. One of its novel features is variable inclination to capture more solar energy in different seasons. Another novel feature is the option to dry product under shade or without shade as per requirement. The rate of drying is uniform in all the trays due to heating of the air by solar energy in between the trays. The maximum stagnation temperature of this solar dryer was found to be 100 deg. C in the month of November at Ludhiana (31 o N). The moisture evaporation on the 1st, 2nd and 3rd drying day for drying fenugreek leaves was 0.23, 0.18 and 0.038 kg/m 2 h. To overcome the problem of reduction in efficiency on the second and third drying day, a semi-continuous mode of loading has been investigated, in which the efficiency remains almost the same on all drying days. The drying rate in the dryer was more than double that in open shade drying. Moreover, the final moisture content of the product was low enough (7.3% wb) for grinding it to a powder form and for good shelf life (1 year). An uncertainty analysis was performed, and the uncertainty in the efficiency was found to be 1.35%. An economic analysis was performed by three methods. The cost of drying fenugreek leaves in the domestic solar dryer turned out to be about 60% of that in an electric dryer. The cumulative present worth of the savings are much higher (18,316 Rupees) than the capital cost of the dryer (1600 Rupees). The payback period is also very low (<2 years) as compared to the life of the dryer (20 years), so the dryer will dry product free of cost during almost its entire life period. The quality and shelf life of the dried products are comparable to those of

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

International Nuclear Information System (INIS)

Haller, M.; Vogelsanger, P.

2005-01-01

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

Natural working fluids for solar-boosted heat pumps

Energy Technology Data Exchange (ETDEWEB)

Chaichana, C.; Lu Aye [University of Melbourne, Victoria (Australia). International Technologies Centre, Department of Civil and Environmental Engineering; Charters, W.W.S. [University of Melbourne, Victoria (Australia). Department of Mechanical and Manufacturing Engineering

2003-09-01

The option of using natural working fluids as a substitute of R-22 for solar-boosted heat pumps depends not only upon thermal performance and hazardous rating but also on potential impacts on the environment. This paper presents the comparative assessment of natural working fluids with R-22 in terms of their characteristics and thermophysical properties, and thermal performance. Some justification is given for using natural working fluids in a solar boosted heat pump water heater. The results show that R-744 is not suitable for solar-boosted heat pumps because of its low critical temperature and high operational pressures. On the other hand, R-717 seems to be a more appropriate substitute in terms of operational parameters and overall performance. However, major changes in the heat pumps are required. R-290 and R-1270 are identified as candidates for direct drop-in substitutes for R-22. (author)

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

Science.gov (United States)

1981-01-01

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

The Heating of the Solar Atmosphere: from the Bottom Up?

Science.gov (United States)

Winebarger, Amy

2014-01-01

The heating of the solar atmosphere remains a mystery. Over the past several decades, scientists have examined the observational properties of structures in the solar atmosphere, notably their temperature, density, lifetime, and geometry, to determine the location, frequency, and duration of heating. In this talk, I will review these observational results, focusing on the wealth of information stored in the light curve of structures in different spectral lines or channels available in the Solar Dynamic Observatory's Atmospheric Imaging Assembly, Hinode's X-ray Telescope and Extreme-ultraviolet Imaging Spectrometer, and the Interface Region Imaging Spectrograph. I will discuss some recent results from combined data sets that support the heating of the solar atmosphere may be dominated by low, near-constant heating events.

Solar chemical heat pipe

International Nuclear Information System (INIS)

Levy, M.; Levitan, R.; Rosin, H.; Rubin, R.

1991-08-01

The performance of a solar chemical heat pipe was studied using CO 2 reforming of methane as a vehicle for storage and transport of solar energy. The endothermic reforming reaction was carried out in an Inconel reactor, packed with a Rh catalyst. The reactor was suspended in an insulated box receiver which was placed in the focal plane of the Schaeffer Solar Furnace of the Weizman Institute of Science. The exothermic methanation reaction was run in a 6-stage adiabatic reactor filled with the same Rh catalyst. Conversions of over 80% were achieved for both reactions. In the closed loop mode the products from the reformer and from the metanator were compressed into separate storage tanks. The two reactions were run either separately or 'on-line'. The complete process was repeated for over 60 cycles. The overall performance of the closed loop was quite satisfactory and scale-up work is in progress in the Solar Tower. (authors). 35 refs., 2 figs

Daytime Solar Heating of Photovoltaic Arrays in Low Density Plasmas

Science.gov (United States)

Galofaro, J.; Vayner, B.; Ferguson, D.

2003-01-01

The purpose of the current work is to determine the out-gassing rate of H2O molecules for a solar array placed under daytime solar heating (full sunlight) conditions typically encountered in a Low Earth Orbital (LEO) environment. Arc rates are established for individual arrays held at 14 C and are used as a baseline for future comparisons. Radiated thermal solar flux incident to the array is simulated by mounting a stainless steel panel equipped with resistive heating elements several centimeters behind the array. A thermal plot of the heater plate temperature and the array temperature as a function of heating time is then obtained. A mass spectrometer is used to record the levels of partial pressure of water vapor in the test chamber after each of the 5 heating/cooling cycles. Each of the heating cycles was set to time duration of 40 minutes to simulate the daytime solar heat flux to the array over a single orbit. Finally the array is cooled back to ambient temperature after 5 complete cycles and the arc rates of the solar arrays is retested. A comparison of the various data is presented with rather some unexpected results.

Flat plate solar collector for water pre-heating using concentrated solar power (CSP)

Science.gov (United States)

Peris, Leonard Sunny; Shekh, Md. Al Amin; Sarker, Imran

2017-12-01

Numerous attempt and experimental conduction on different methods to harness energy from renewable sources are being conducted. This study is a contribution to the purpose of harnessing solar energy as a renewable source by using flat plate solar collector medium to preheat water. Basic theory of solar radiation and heat convection in water (working fluid) has been combined with heat conduction process by using copper tubes and aluminum absorber plate in a closed conduit, covered with a glazed through glass medium. By this experimental conduction, a temperature elevation of 35°C in 10 minutes duration which is of 61.58% efficiency range (maximum) has been achieved. The obtained data and experimental findings are validated with the theoretical formulation and an experimental demonstration model. A cost effective and simple form of heat energy extraction method for space heating/power generation has been thoroughly discussed with possible industrial implementation possibilities. Under-developed and developing countries can take this work as an illustration for renewable energy utilization for sustainable energy prospect. Also a full structure based data to derive concentrated solar energy in any geographical location of Bangladesh has been outlined in this study. These research findings can contribute to a large extent for setting up any solar based power plant in Bangladesh irrespective of its installation type.

Experimental Investigation of a Solar Greenhouse Heating System Equipped with a Parabolic Trough Solar Concentrator and a Double-Purpose Flat Plate Solar Collector

Directory of Open Access Journals (Sweden)

M Jafari

2017-10-01

Full Text Available Introduction Greenhouses provide a suitable environment in which all the parameters required for growing the plants can be controlled throughout the year. Greenhouse heating is one of the most important issues in productivity of a greenhouse. In many countries, heating costs in the greenhouses are very high, having almost 60-80% of the total production costs. In recent years, several studies have attempted to reduce the heating costs of the greenhouses by applying more energy efficient equipment and using the renewable energy sources as alternatives or supplementary to the fossil fuels. In the present study a novel solar greenhouse heating system equipped with a parabolic trough solar concentrator (PTC and a flat-plate solar collector has been developed. Therefore, the aim of this paper is to investigate the performance of the proposed heating system at different working conditions. Materials and Methods The presented solar greenhouse heating system was comprised of a parabolic trough solar concentrator (PTC, a heat storage tank, a pump and a flat plate solar collector. The PTC was constructed from a polished stainless steel sheet (as the reflector and a vacuum tube receiver. The PTC was connected to the tank by using insulated tubes and a water pump was utilized to circulate the working fluid trough the PTC and the heat exchanger installed between walls of the tank. The uncovered solar collector was located inside the greenhouse. During the sunshine time, a fraction of the total solar radiation received inside the greenhouse is absorbed by the solar collector. This rises the temperature of the working fluid inside the collector which led to density reduction and natural flow of the fluid. In other words, the collector works as a natural flow flat plate solar collector during the sunshine time. At night, when the greenhouse temperature is lower than tank temperature, the fluid flows in a reverse direction through the solar collector and the

Improved model for solar heating of buildings

OpenAIRE

Lie, Bernt

2015-01-01

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

Design of a Heat Pump Assisted Solar Thermal System

OpenAIRE

Krockenberger, Kyle G.; DeGrove, John M.; Hutzel, William J.; Foreman, J. Christopher

2014-01-01

This paper outlines the design of an active solar thermal loop system that will be integrated with an air source heat pump hot water heater to provide highly efficient heating of a water/propylene glycol mixture. This system design uses solar energy when available, but reverts to the heat pump at night or during cloudy weather. This new design will be used for hydronic heating in the Applied Energy Laboratory, a teaching laboratory at Purdue University, but it is more generally applicable for...

Solar energy and global heat balance of a city

Energy Technology Data Exchange (ETDEWEB)

Roulet, Claude-Alain [Ecole Polytechnique Federale, Lab. d' Energie Solaire et de Physique du Batiment, Lausanne (Switzerland)

2001-07-01

The global energy balance of a city involves numerous energy flows and is rather complex. It includes, among others, the absorbed solar radiation and the energy fuels on one hand, and the heat loss to the environment --- by radiation, convection and evaporation --- on the other hand. This balance generally results in a temperature in the town that is slightly higher than in the surrounding country. Using solar energy saves imported fuels on one hand, but increases the absorption of solar radiation on the other hand. Simple, steady state models are used to assess the change of heat released to the environment when replacing the use of classical fuels by solar powered plants, on both the global and city scale. The conclusion is that, in most cases, this will reduce the heat released to the environment. The exception is cooling, for which a good solar alternative does not exist today. (Author)

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

DEFF Research Database (Denmark)

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

2003-01-01

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

Performance of a solar augmented heat pump

Science.gov (United States)

Bedinger, A. F. G.; Tomlinson, J. J.; Reid, R. L.; Chaffin, D. J.

Performance of a residential size solar augmented heat pump is reported for the 1979-1980 heating season. The facility located in Knoxville, Tennessee, has a measured heat load coefficient of 339.5 watt/C (644 BTU/hr- F). The solar augmented heat pump system consists of 7.4 cu m of one inch diameter crushed limestone. The heat pump is a nominal 8.8 KW (2 1/2 ton) high efficiency unit. The system includes electric resistance heaters to give the option of adding thermal energy to the pebble bed storage during utility off-peak periods, thus offering considerable load management capability. A 15 KW electric resistance duct heater is used to add thermal energy to the pebble bin as required during off-peak periods. Hourly thermal performance and on site weather data was taken for the period November 1, 1979, to April 13, 1980. Thermal performance data consists of heat flow summations for all modes of the system, pebble bed temperatures, and space temperature. Weather data consists of dry bulb temperature, dew point temperature, total global insolation (in the plane of the collector), and wind speed and direction. An error analysis was performed and the least accurate of the measurements was determined to be the heat flow at 5%. Solar system thermal performance factor was measured to be 8.77. The heat pump thermal performance factor was 1.64. Total system seasonal performance factor was measured to be 1.66. Using a modified version of TRNSYS, the thermal performance of this system was simulated. When simulation results were compared with data collected onsite, the predicted heat flow and power consumption generally were within experimental accuracy.

On the addition of heat to solar pond from external sources

NARCIS (Netherlands)

Ganguly, S.; Jain, Ravi; Date, Abhijit; Akbarzadeh, Aliakbar

2017-01-01

This brief note addresses the method of adding heat to a solar pond from an external source which is used to enhance the performance of a solar pond. Heat energy collected by Evacuated Tube Solar Collectors (ETSC) is transferred by circulating fluid from the Lower Convective Zone (LCZ) of a solar

MULTI-HEAT SOURCE SOLAR HEAT PUMP HEAT SUPPLY SYSTEM AND PERFORMANCE SIMULATION%复合热源太阳能热泵供热系统及其性能模拟

Institute of Scientific and Technical Information of China (English)

杨磊; 张小松

2011-01-01

提出了一种复合热源太阳能热泵供热系统,通过阀门切换,可根据不同的天气状况改变运行模式,以空气和太阳辐射作为热源制取供暖用水.针对所设计的lOkw供热系统,建立了系统的数学模型,对热泵串联集热器(SC+HP)及集热器串联热泵(HP+SC)两种运行模式下的循环性能进行了计算机模拟分析,并计算了系统的全年运行状况.从模拟结果可以看出,在模拟进水温度区间内,HP+SC模式下热泵COP较高,最高比SC+HP模式高2.58%;而SC+HP模式集热器热性能较好,总热效率更高,最高比HP+SC模式高2.62%.%A compound solar heat pump heat supply system was presented. The system can make heating water from air source and solar radiation by valve switching, based on different weather conditions. A numerical model for a l0kW heating utilizing was established. The circulation performances of solar collector with heat pump( SC + HP) and heat pump with solar collector( Hp + SC) operation modes were simulated. The all year round operation status was also caculated.The results have shown that the COP of HP + SC mode is at most 2.58 ％ higher than SC + HP mode in simulation water temperature range. But the latter has a better collector thermal performance and overall thermal efficiency is at most 2.62 ％ higher than the former.

Efficiency analysis of solar facilities for building heating and household water heating under conditions in the Czech Republic

OpenAIRE

Pivko, Michal; Jursová, Simona; Turjak, Juraj

2012-01-01

The paper studies the efficiency of solar facilities applied for the heating of buildings and household water heating in the Czech Republic. The Czech Republic is situated in the temperate zone characterized by changeable weather. It is respected in the assessment of a solar facility installation. The efficiency of solar facilities is evaluated according to energy and economic balances. It is analyzed for solar facilities heating both household water and buildings. The main problems relating ...

Financial barriers to the use of solar-industrial-process heat

Energy Technology Data Exchange (ETDEWEB)

1981-03-01

Industry concerns about solar process heat, attitudes toward investment in solar process heat, and decision processes and factors are reported. Four cases were selected from among 30 potential solar process heat installations that had been carried through the design stage, and case was analyzed using discounted cash flow to determine what internal rate of return would be earned under current tax laws over 10 years. No case showed any significant rate of return from capital invested in the solar installation. Several possible changes in the cost of solar equipment, its tax treatment or methods of financing were tested through computer simulation. A heavy load of extra tax incentives can improve the return on an investment, but such action is not recommended because they are not found to induce adoption of solar process heat, and if they were effective, capital may be drawn away from applications such as conservation were the potential to improve the nation's energy dilemma is greater. Tax shelter financing through limited partnership may be available. (LEW)

Theoretical and experimental investigation of wickless heat pipes flat plate solar collector with cross flow heat exchanger

International Nuclear Information System (INIS)

Hussein, H.M.S.

2007-01-01

In this work, a wickless heat pipes flat plate solar collector with a cross flow heat exchanger was investigated theoretically and experimentally under the meteorological conditions of Cairo, Egypt. The author's earlier simulation program of wickless heat pipes flat plate solar water heaters was modified to be valid for the present type of wickless heat pipes solar collector by including the solution of the dimensionless governing equations of the present analysis. For verifying the modified simulation program, a wickless heat pipes flat plate solar collector with a cross flow heat exchanger was designed, constructed, and tested at different meteorological conditions and operating parameters. These parameters include different cooling water mass flow rates and different inlet cooling water temperatures. The comparison between the experimental results and their corresponding simulated ones showed considerable agreement. Under different climatic conditions, the experimental and theoretical results showed that the optimal mass flow rate is very close to the ASHRAE standard mass flow rate for testing conventional flat plate solar collectors. Also, the experimental and theoretical results indicated that the number of wickless heat pipes has a significant effect on the collector efficiency

The Utilisation of Solar System in Combined Heating System of Water

Directory of Open Access Journals (Sweden)

Ján Jobbágy

2017-01-01

Full Text Available The paper assessed the topicality and returns of solar system utilization to heating of water. Practical measurements were conducted after reconstruction of the family house. (in Nesvady, Slovak republic, on which the solar system were assembled. The system consists of the gas heater, solar panels, distributions and circulation pump. The solar system was assembled due to decreasing of operation costs and connected with conventional already used gas heating system by boiler Quantum (V = 115 L. The conventional system was used for 21 days to gather basic values for evaluation. At this point it was observed that 11.93 m3 of gas is needed to heat up 1 m3 of water. Used water in this case was heated from initial 16.14 °C to 52.04 °C of output temperature. Stand by regime of boiler was characterized by 0.012 m3.h-1 consumption of gas. The rest of the measurements represent the annual (from 03/2013 to 02/2014 operation process of boiler Tatramat VTS 200L (trivalent with 200 litres of volume (as a part of Thermosolar solar system. The solar collectors TS 300 are also part of the solar system. An input and output temperatures of heating water we observed along with water and gas consumption, intensity of solar radiation and actual weather conditions. The amount of heat produced by solar system was then calculated. Total investment on solar system were 2,187.7 € (1,475.7 € with subsidy. Therefore, return on investment for the construction of the solar system was set at 23 years even with subsidy.

Thermal analysis of a multi-layer microchannel heat sink for cooling concentrator photovoltaic (CPV) cells

Science.gov (United States)

Siyabi, Idris Al; Shanks, Katie; Mallick, Tapas; Sundaram, Senthilarasu

2017-09-01

Concentrator Photovoltaic (CPV) technology is increasingly being considered as an alternative option for solar electricity generation. However, increasing the light concentration ratio could decrease the system output power due to the increase in the temperature of the cells. The performance of a multi-layer microchannel heat sink configuration was evaluated using numerical analysis. In this analysis, three dimensional incompressible laminar steady flow model was solved numerically. An electrical and thermal solar cell model was coupled for solar cell temperature and efficiency calculations. Thermal resistance, solar cell temperature and pumping power were used for the system efficiency evaluation. An increase in the number of microchannel layers exhibited the best overall performance in terms of the thermal resistance, solar cell temperature uniformity and pressure drop. The channel height and width has no effect on the solar cell maximum temperature. However, increasing channel height leads to a reduction in the pressure drop and hence less fluid pumping power.

Modelling and Control of Collecting Solar Energy for Heating Houses in Norway

Directory of Open Access Journals (Sweden)

Mehran Dehghan

2017-09-01

Full Text Available In this research, a new model was developed and modified with a combined solar heating system which works with solar radiation and electricity. In order to model the system, the outdoor temperature of the location and solar irradiance has been considered. The case study of this research has been done in Porsgrunn City in the south of Norway. The building which was modelled in this research is a passive solar building which is able to store heat by using phase change materials, which are mounted on the floor and release the heat when the temperature of the house decreases. The model of the house was designed based on some assumptions about ambient temperature, solar collector size, transmitting lines length and some specific properties like air density and specific heat. The results of this research show that a solar heating system which is working with electricity can provide a sufficient temperature for the house in winter time. With using the phase change materials in order to have a passive solar building design, an improvement in the temperature inside the house was seen. Based on the simulation results which were achieved, a solar heating system which works with electricity can be an efficient system to heat the house, especially in the winter times.

A Numerical Study on the Heat Transfer Characteristics of a Solar Thermal Receiver with High-temperature Heat Pipes

International Nuclear Information System (INIS)

Park, Young Hark; Jung, Eui Guk; Boo, Joon Hong

2007-01-01

A numerical analysis was conducted to predict the heat transfer characteristics of a solar receiver which is subject to very high heat fluxes and temperatures for solar thermal applications. The concentration ratio of the solar receiver ranges from 200 to 1000 and the concentrated heat is required to be transported to a certain distance for specific applications. The study deals with a solar receiver incorporating high-temperature sodium heat pipe as well as typical one that employs a molten-salt circulation loop. The isothermal characteristics in the receiver section is of major concern. The diameter of the solar thermal receiver was 120 mm and the length was 400 mm. For the molten-salt circulation type receiver, 48 axial channels of the same dimensions were attached to the outer wall of the receiver with even spacing in the circumferential direction. The molten salt fed through the channels by forced convection using a special pump. For the heat pipe receiver, the channels are changed to high-temperature sodium heat pipes. Commercial softwares were employed to deal with the radiative heat transfer inside the receiver cavity and the convection heat transfer along the channels. The numerical results are compared and analyzed from the view point of high-temperature solar receiver

Solar thermoelectricity via advanced latent heat storage

Science.gov (United States)

Olsen, M. L.; Rea, J.; Glatzmaier, G. C.; Hardin, C.; Oshman, C.; Vaughn, J.; Roark, T.; Raade, J. W.; Bradshaw, R. W.; Sharp, J.; Avery, A. D.; Bobela, D.; Bonner, R.; Weigand, R.; Campo, D.; Parilla, P. A.; Siegel, N. P.; Toberer, E. S.; Ginley, D. S.

2016-05-01

We report on a new modular, dispatchable, and cost-effective solar electricity-generating technology. Solar ThermoElectricity via Advanced Latent heat Storage (STEALS) integrates several state-of-the-art technologies to provide electricity on demand. In the envisioned STEALS system, concentrated sunlight is converted to heat at a solar absorber. The heat is then delivered to either a thermoelectric (TE) module for direct electricity generation, or to charge a phase change material for thermal energy storage, enabling subsequent generation during off-sun hours, or both for simultaneous electricity production and energy storage. The key to making STEALS a dispatchable technology lies in the development of a "thermal valve," which controls when heat is allowed to flow through the TE module, thus controlling when electricity is generated. The current project addresses each of the three major subcomponents, (i) the TE module, (ii) the thermal energy storage system, and (iii) the thermal valve. The project also includes system-level and techno- economic modeling of the envisioned integrated system and will culminate in the demonstration of a laboratory-scale STEALS prototype capable of generating 3kWe.

Solar air heating system for combined DHW and space heating

Energy Technology Data Exchange (ETDEWEB)

Oestergaard Jensen, S.; Bosanac, M.

2002-12-01

The project deals with the development and testing of a simple system for utilization of the summer excess heat from small solar air heating systems for preheating of fresh air. The principle of the system is to lead the heated air down around a domestic hot water tank letting the surface of the tank act as heat exchanger between the air and the water. In order to increase the heat transfer, coefficient fins into the air stream were mounted on the tank. A complete system with 3 m{sup 2} solar air collector, ductworks and a 85 litre storage were set up and extensively monitored. The air stream through the system was created by a fan connected directly to one or two PV-panels leading to a solar radiation dependent flow rate without the use of any other control. Based on monitoring results the system was characterized and a TRNSYS model of the system was developed and calibrated/validated. The monitoring and the simulations with the TRNSYS model revealed several interesting things about the system. The monitoring revealed that the system is capable of bringing the temperature of the water in the storage above 60 deg. C at warm days with clear sky conditions. The storage is very stratified, which is beneficial as usable hot water temperatures rather quickly are obtained. The performance was highly dependent on the airflow rate through the system. It can be concluded that the investigated system will have a performance in the order of 500 kWh during the winter, spring and autumn months and around 250 kWh during the four summer months - or in total a yearly performance of 750 kWh/m{sup 2}. A small traditional solar heating system for preheating of domestic hot water would have a higher performance during the four summer months, but no performance during the rest of the year if the system is installed in a summer house, which only is occupied during the summer. The parametric analysis further indicates that it is possible to further optimise the system when the thermal

Solar heating for an electronics manufacturing plant--Blue Earth, Minnesota

Science.gov (United States)

1981-01-01

Partial space heating for 97,000 square foot plant is supplied by 360 flat plate solar collectors; energy is sorted as heat in indoor 20,000 gallon water tank. System includes all necessary control electronics for year round operation. During December 1978, solar energy supplied 24.4 percent of building's space heating load.

Optimal study of a solar air heating system with pebble bed energy storage

International Nuclear Information System (INIS)

Zhao, D.L.; Li, Y.; Dai, Y.J.; Wang, R.Z.

2011-01-01

Highlights: → Use two kinds of circulation media in the solar collector. → Air heating and pebble bed heat storage are applied with different operating modes. → Design parameters of the system are optimized by simulation program. → It is found that the system can meet 32.8% of the thermal energy demand in heating season. → Annual solar fraction aims to be 53.04%. -- Abstract: The application of solar air collectors for space heating has attracted extensive attention due to its unique advantages. In this study, a solar air heating system was modeled through TRNSYS for a 3319 m 2 building area. This air heating system, which has the potential to be applied for space heating in the heating season (from November to March) and hot water supply all year around in North China, uses pebble bed and water storage tank as heat storage. Five different working modes were designed based on different working conditions: (1) heat storage mode, (2) heating by solar collector, (3) heating by storage bed, (4) heating at night and (5) heating by an auxiliary source. These modes can be operated through the on/off control of fan and auxiliary heater, and through the operation of air dampers manually. The design, optimization and modification of this system are described in this paper. The solar fraction of the system was used as the optimization parameter. Design parameters of the system were optimized by using the TRNSYS program, which include the solar collector area, installation angle of solar collector, mass flow rate through the system, volume of pebble bed, heat transfer coefficient of the insulation layer of the pebble bed and water storage tank, height and volume of the water storage tank. The TRNSYS model has been verified by data from the literature. Results showed that the designed solar system can meet 32.8% of the thermal energy demand in the heating season and 84.6% of the energy consumption in non-heating season, with a yearly average solar fraction of 53.04%.

Thermal analyses of solar swimming pool heating in Pakistan

International Nuclear Information System (INIS)

Ahmad, I.

2011-01-01

Hotels and swimming clubs in Pakistan pay huge gas bills for heating Swimming pools in winter. Winter days in most parts of Pakistan remain sunny and unglazed low cost solar collectors may be used to extend the swimming season. Installing the pool in a wind-protected area, which receives unobstructed solar radiation, may further reduce the size of the solar collectors required to heat the swimming pools. The pools should be covered with plastic sheet to eliminate evaporative heat losses and to prevent dust and tree leaves falling in the pool. The results of the thermal analysis show that in some parts of the country, a solar exposed pool can maintain comfortable temperature simply by using a plastic sheet on the pool surface. On the other hand, there are cities where solar collector array equal to twice the surface area of the pool is required to keep desired temperature in winter. (author)

Experimental analysis of a direct expansion solar assisted heat pump with integral storage tank for domestic water heating under zero solar radiation conditions

International Nuclear Information System (INIS)

Fernández-Seara, José; Piñeiro, Carolina; Alberto Dopazo, J.; Fernandes, F.; Sousa, Paulo X.B.

2012-01-01

Highlights: ► We analyze a direct expansion solar assisted heat pump under zero solar radiation. ► We determine the COP and equivalent seasonal performance factors (SPFe). ► We determine the main components’ performance under transient operating conditions. ► The Huang and Lee performance evaluation method provides a characteristic COP of 3.23. - Abstract: This paper deals with the experimental evaluation of the performance of a direct expansion solar assisted heat pump water heating (DX-SAHPWH) system working under zero solar radiation conditions at static heating operation mode of the storage tank. The DX-SAHPWH system includes two bare solar collectors as evaporator, a R134a rotary-type hermetic compressor, a thermostatic expansion valve and a helical coil condenser immersed in a 300 L water storage tank. The zero solar radiation and stable ambient air temperature working conditions were established by placing the solar collectors into a climate chamber. The analysis is based on experimental data taken from the DX-SAHPWH provided by the manufacturer and equipped with an appropriate data acquisition system. In the paper, the experimental facility, the data acquisition system and the experimental methodology are described. Performance parameters to evaluate the energy efficiency, such as COP and equivalent seasonal performance factors (SPFe) for the heating period, and the water thermal stratification in the storage tank are defined and obtained from the experimental data. Results from the experimental analysis under transient operating working conditions of the DX-SAHPWH system and its main components are shown and discussed. Lastly, the Huang and Lee DX-SAHPWH performance evaluation method was applied resulting in a characteristic COP of 3.23 for the DX-SAHPWH system evaluated under zero solar radiation condition.

Frosting characteristics and heating performance of a direct-expansion solar-assisted heat pump for space heating under frosting conditions

International Nuclear Information System (INIS)

Huang, Wenzhu; Ji, Jie; Xu, Ning; Li, Guiqiang

2016-01-01

Highlights: • Frosting and heating performance of DX-SAHP under frosting conditions is investigated. • The conditions when DX-SAHP frosts are studied. • The frosting process is observed during 360 min of operating. • The effect of ambient temperature, relative humidity and solar irradiation is analyzed. - Abstract: Direct expansion solar-assisted heat pump system (DX-SAHP) is promising in energy saving applications, but the performance of DX-SAHP under frosting conditions is rarely reported in the published literatures. In this paper, a DX-SAHP system with bare solar collectors for space heating is designed and experimentally investigated in the enthalpy difference lab with a solar simulator. The system is tested under a range of frosting conditions, with the ambient temperatures from 7 °C to −3 °C, the relative humidities of 50%, 70% and 90% and the solar irradiances of 0 W/m"2, 100 W/m"2, 200 W/m"2 and 300 W/m"2. The conditions when the DX-SAHP system frosts are studied. Results show that solar irradiance as low as 100 W/m"2 can totally prevent frosting when the ambient temperature is above −3 °C and the relative humidity is 70%. Besides, the frosting process is observed to be slower than that of fin-and-tube heat exchangers. The evaporator is not seriously frosted and the system performance is not significantly influenced after 360 min of continuous operating. Moreover the effects of ambient parameters, including the ambient temperature and the relative humidity, especially solar irradiation, on the system performance are studied and analyzed. Solar irradiation can effectively prevent or retard frosting, and also improve the heating performance of the DX-SAHP system. The DX-SAHP system is proved to be applicable under frosting conditions.

Solar-heated municipal swimming pools, a case study: Dade County, Florida

Science.gov (United States)

Levin, M.

1981-09-01

The installation of a solar energy system to heat the water in the swimming pool in one of Dade County, Florida's major parks is described. The mechanics of solar heated swimming pools are explained. The solar heating system consists of 216 unglazed polypropylene tube collectors, a differential thermostat, and the distribution system. The systems performance and economics as well as future plants are discussed.

Characterization of a solar photovoltaic/loop-heat-pipe heat pump water heating system

International Nuclear Information System (INIS)

Zhang, Xingxing; Zhao, Xudong; Xu, Jihuan; Yu, Xiaotong

2013-01-01

Highlights: ► Describing concept and operating principle of the PV/LHP heat pump water heating system. ► Developing a numerical model to evaluate the performance of the system. ► Experimental testing of the prototype system. ► Characterizing the system performance using parallel comparison between the modelling and experimental results. ► Investigating the impact of the operating conditions to the system’s performance. -- Abstract: This paper introduced the concept, potential application and benefits relating to a novel solar photovoltaic/loop-heat-pipe (PV/LHP) heat pump system for hot water generation. On this basis, the paper reported the process and results of characterizing the performance of such a system, which was undertaken through dedicated thermo-fluid and energy balance analyses, computer model development and operation, and experimental verification and modification. The fundamental heat transfer, fluid flow and photovoltaic governing equations were applied to characterize the energy conversion and transfer processes occurring in each part and whole system layout; while the energy balance approach was utilized to enable inter-connection and resolution of the grouped equations. As a result, a dedicated computer model was developed and used to calculate the operational parameters, optimise the geometrical configurations and sizes, and recommend the appropriate operational condition relating to the system. Further, an experimental rig was constructed and utilized to acquire the relevant measurement data that thus enabled the parallel comparison between the simulation and experiment. It is concluded that the testing and modelling results are in good agreement, indicating that the model has the reasonable accuracy in predicting the system’s performance. Under the given experimental conditions, the electrical, thermal and overall efficiency of the PV/LHP module were around 10%, 40% and 50% respectively; whilst the system’s overall performance

Optimization of flat-plate solar energy heat pipe collector parameters

Energy Technology Data Exchange (ETDEWEB)

Vasiliev, L L; Garakovich, L P; Khrustalev, D K

1984-01-01

Performance characteristics of flat solar energy collectors with heat pipes have been analysed with regard to various parameters. Their advantages are discussed. The use of heat pipes in solar energy collectors is proved to be efficient.

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

International Nuclear Information System (INIS)

Faninger, G.

1998-04-01

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

Solar heat and heat pump. What benefits?; Solarthermie und Waermepumpe. Was bringt's?

Energy Technology Data Exchange (ETDEWEB)

Droescher, Angela; Heinz, Andreas [Technische Univ. Graz (Austria). Inst. fuer Waermetechnik; Gerardts, Bernhard [Solid GmbH, Graz (Austria)

2013-11-08

If solar heating and heat pumps work together, then usually in a single-family house. The fact that there is another way, shows a large solar heating system in Graz. Investigations show what potential there is in this type of system and where special attention is needed. [German] Wenn Solarwaerme und Waermepumpen zusammenarbeiten, dann meist im Einfamilienhaus. Dass es auch anders geht, zeigt eine Grossanlage bei Graz. Untersuchungen zeigen, welche Potenziale es bei Systemen dieser Art gibt und worauf besonders zu achten ist.

Packaged solar water heating technology: twenty years of progress

International Nuclear Information System (INIS)

Morrison, Graham; Wood, Byard

2000-01-01

The world market for packaged solar water heaters is reviewed, and descriptions are given of the different types of solar domestic water heaters (SDWH), design concepts for packaged SDWH, thermosyphon SDWH, evacuated insulation and excavated tube collectors, seasonally biased solar collectors, heat pump water heaters, and photovoltaic water heaters. The consumer market value for SDWHs is explained, and the results of a survey of solar water heating are summarised covering advantages, perceived disadvantages, the relative importance of purchase decision factors, experience with system components, and the most frequent maintenance problems. The durability, reliability, and performance of SDWHs are discussed

Electron heat flux instabilities in the solar wind

International Nuclear Information System (INIS)

Gary, S.P.; Feldman, W.C.; Forslund, D.W.; Montgomery, M.D.

1975-01-01

There are at least three plasma instabilities associated with the electron heat flux in the solar wind. This letter reports the study of the unstable fast magnetosonic, Alfven and whistler modes via a computer code which solves the full electromagnetic, linear, Vlasov dispersion relation. Linear theory demonstrates that both the magnetosonic and Alfven instabilities are candidates for turbulent limitation of the heat flux in the solar wind at 1 A.U

Solar-Heated Office Building -- Dallas, Texas

Science.gov (United States)

1982-01-01

Solar heating system designed to supply 87 percent of space heating and 100 percent of potable hot-water needs of large office building in Dallas, Texas. Unique feature of array serves as roofing over office lobby and gives building attractive triangular appearance. Report includes basic system drawings, test data, operating procedures, and maintenance instructions.

A New Approach to Observing Coronal Dynamics: MUSE, the Multi-Slit Solar Explorer

Science.gov (United States)

Tarbell, T. D.

2017-12-01

The Multi-Slit Solar Explorer is a Small Explorer mission recently selected for a Phase A study, which could lead to a launch in 2022. It will provide unprecendented observations of the dynamics of the corona and transition region using both conventional and novel spectral imaging techniques. The physical processes that heat the multi-million degree solar corona, accelerate the solar wind and drive solar activity (CMEs and flares) remain poorly known. A breakthrough in these areas can only come from radically innovative instrumentation and state-of-the-art numerical modeling and will lead to better understanding of space weather origins. MUSE's multi-slit coronal spectroscopy will exploit a 100x improvement in spectral raster cadence to fill a crucial gap in our knowledge of Sun-Earth connections; it will reveal temperatures, velocities and non-thermal processes over a wide temperature range to diagnose physical processes that remain invisible to current or planned instruments. MUSE will contain two instruments: an EUV spectrograph (SG) and EUV context imager (CI). Both have similar spatial resolution and leverage extensive heritage from previous high-resolution instruments such as IRIS and the HiC rocket payload. The MUSE investigation will build on the success of IRIS by combining numerical modeling with a uniquely capable observatory: MUSE will obtain EUV spectra and images with the highest resolution in space (1/3 arcsec) and time (1-4 s) ever achieved for the transition region and corona, along 35 slits and a large context FOV simultaneously. The MUSE consortium includes LMSAL, SAO, Stanford, ARC, HAO, GSFC, MSFC, MSU, ITA Oslo and other institutions.

Solar heating still in the early stages. Changes for hot water production - VDI meeting 'Efficient heating systems'

Energy Technology Data Exchange (ETDEWEB)

Goehringer, P

1976-10-01

More and more realism replaces the initial euphoria concerning the discussion on solar heating. Not only the possibilities are considered these days, but also the limits of this still controversial way of heating. This impression was deepened by a meeting of the VDI-Gesellschaft Technische Gebaeudeausruestung (Society for the technical equipment of buildings) held in Bonn. The heating of water with solar energy during the summer is viewed optimistically by the experts - as far as space heating is concerned, the sun collector is conceded only a very modest position in Central Europe within integrated heating systems. It is true that solar technology in the USA is already very sophisticated and economically feasible in many cases; however, techniques cannot be adopted unconditionally for Europe, as the average values of global solar radiation are much lower here. Thus, different technologies will be required.

Prototype solar heating and combined heating and cooling systems. Quarterly report No. 6

Energy Technology Data Exchange (ETDEWEB)

1978-01-06

The General Electric Company is developing eight prototype solar heating and combined heating and cooling systems. This effort includes development, manufacture, test, installation, maintenance, problem resolution, and performance evaluation.

Thermal performance of evacuated tube heat pipe solar collector

Science.gov (United States)

Putra, Nandy; Kristian, M. R.; David, R.; Haliansyah, K.; Ariantara, Bambang

2016-06-01

The high fossil energy consumption not only causes the scarcity of energy but also raises problems of global warming. Increasing needs of fossil fuel could be reduced through the utilization of solar energy by using solar collectors. Indonesia has the abundant potential for solar energy, but non-renewable energy sources still dominate energy consumption. With heat pipe as passive heat transfer device, evacuated tube solar collector is expected to heat up water for industrial and home usage without external power supply needed to circulate water inside the solar collector. This research was conducted to determine the performance of heat pipe-based evacuated tube solar collector as solar water heater experimentally. The experiments were carried out using stainless steel screen mesh as a wick material, and water and Al2O3-water 0.1% nanofluid as working fluid, and applying inclination angles of 0°, 15°, 30°, and 45°. To analyze the heat absorbed and transferred by the prototype, water at 30°C was circulated through the condenser. A 150 Watt halogen lamp was used as sun simulator, and the prototype was covered by an insulation box to obtain a steady state condition with a minimum affection of ambient changes. Experimental results show that the usage of Al2O3-water 0.1% nanofluid at 30° inclination angle provides the highest thermal performance, which gives efficiency as high as 0.196 and thermal resistance as low as 5.32 °C/W. The use of nanofluid as working fluid enhances thermal performance due to high thermal conductivity of the working fluid. The increase of the inclination angle plays a role in the drainage of the condensate to the evaporator that leads to higher thermal performance until the optimal inclination angle is reached.

Effects of Solar Photovoltaic Panels on Roof Heat Transfer

Science.gov (United States)

Dominguez, A.; Klessl, J.; Samady, M.; Luvall, J. C.

2010-01-01

Building Heating, Ventilation and Air Conditioning (HVAC) is a major contributor to urban energy use. In single story buildings with large surface area such as warehouses most of the heat enters through the roof. A rooftop modification that has not been examined experimentally is solar photovoltaic (PV) arrays. In California alone, several GW in residential and commercial rooftop PV are approved or in the planning stages. With the PV solar conversion efficiency ranging from 5-20% and a typical installed PV solar reflectance of 16-27%, 53-79% of the solar energy heats the panel. Most of this heat is then either transferred to the atmosphere or the building underneath. Consequently solar PV has indirect effects on roof heat transfer. The effect of rooftop PV systems on the building roof and indoor energy balance as well as their economic impacts on building HVAC costs have not been investigated. Roof calculator models currently do not account for rooftop modifications such as PV arrays. In this study, we report extensive measurements of a building containing a flush mount and a tilted solar PV array as well as exposed reference roof. Exterior air and surface temperature, wind speed, and solar radiation were measured and thermal infrared (TIR) images of the interior ceiling were taken. We found that in daytime the ceiling surface temperature under the PV arrays was significantly cooler than under the exposed roof. The maximum difference of 2.5 C was observed at around 1800h, close to typical time of peak energy demand. Conversely at night, the ceiling temperature under the PV arrays was warmer, especially for the array mounted flat onto the roof. A one dimensional conductive heat flux model was used to calculate the temperature profile through the roof. The heat flux into the bottom layer was used as an estimate of the heat flux into the building. The mean daytime heat flux (1200-2000 PST) under the exposed roof in the model was 14.0 Watts per square meter larger than

Large scale solar district heating. Evaluation, modelling and designing

Energy Technology Data Exchange (ETDEWEB)

Heller, A.

2000-07-01

The main objective of the research was to evaluate large-scale solar heating connected to district heating (CSDHP), to build up a simulation tool and to demonstrate the application of the tool for design studies and on a local energy planning case. The evaluation of the central solar heating technology is based on measurements on the case plant in Marstal, Denmark, and on published and unpublished data for other, mainly Danish, CSDHP plants. Evaluations on the thermal, economical and environmental performances are reported, based on the experiences from the last decade. The measurements from the Marstal case are analysed, experiences extracted and minor improvements to the plant design proposed. For the detailed designing and energy planning of CSDHPs, a computer simulation model is developed and validated on the measurements from the Marstal case. The final model is then generalised to a 'generic' model for CSDHPs in general. The meteorological reference data, Danish Reference Year, is applied to find the mean performance for the plant designs. To find the expectable variety of the thermal performance of such plants, a method is proposed where data from a year with poor solar irradiation and a year with strong solar irradiation are applied. Equipped with a simulation tool design studies are carried out spreading from parameter analysis over energy planning for a new settlement to a proposal for the combination of plane solar collectors with high performance solar collectors, exemplified by a trough solar collector. The methodology of utilising computer simulation proved to be a cheap and relevant tool in the design of future solar heating plants. The thesis also exposed the demand for developing computer models for the more advanced solar collector designs and especially for the control operation of CSHPs. In the final chapter the CSHP technology is put into perspective with respect to other possible technologies to find the relevance of the application

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

Science.gov (United States)

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

2016-03-01

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

Performance of commercially available solar and heat pump water heaters

International Nuclear Information System (INIS)

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

2008-01-01

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

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

Science.gov (United States)

1981-01-01

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

The relation of collector and storage tank size in solar heating systems

International Nuclear Information System (INIS)

Çomaklı, Kemal; Çakır, Uğur; Kaya, Mehmet; Bakirci, Kadir

2012-01-01

Highlights: ► A storage tank is used in many solar water heating systems for the storage of hot water. ► Using larger storage tanks decrease the efficiency and increases the cost of the system. ► The optimum tank size for the collector area is very important for economic solar heating systems. ► The optimum sizes of the collectors and the storage tank are determined. - Abstract: The most popular method to benefit from the solar energy is to use solar water heating systems since it is one of the cheapest way to benefit from the solar energy. The investment cost of a solar water heating system is very low, and the maintenance costs are nearly zero. Using the solar energy for solar water heating (SWH) technology has been greatly improved during the past century. A storage tank is used in many solar water heating systems for the conservation of heat energy or hot water for use when some need it. In addition, domestic hot water consumption is strongly variable in many buildings. It depends on the geographical situation, also on the country customs, and of course on the type of building usage. Above all, it depends on the inhabitants’ specific lifestyle. For that reason, to provide the hot water for consumption at the desirable temperature whenever inhabitants require it, there must be a good relevance between the collectors and storage tank. In this paper, the optimum sizes of the collectors and the storage tank are determined to design more economic and efficient solar water heating systems. A program has been developed and validated with the experimental study and environmental data. The environmental data were obtained through a whole year of operation for Erzurum, Turkey.

Heat engine development for solar thermal power systems

Science.gov (United States)

Pham, H. Q.; Jaffe, L. D.

The parabolic dish solar collector systems for converting sunlight to electrical power through a heat engine will, require a small heat engine of high performance long lifetime to be competitive with conventional power systems. The most promising engine candidates are Stirling, high temperature Brayton, and combined cycle. Engines available in the current market today do not meet these requirements. The development of Stirling and high temperature Brayton for automotive applications was studied which utilizes much of the technology developed in this automotive program for solar power engines. The technical status of the engine candidates is reviewed and the components that may additional development to meet solar thermal system requirements are identified.

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.

Optimum performance characteristics of a solar-driven Stirling heat engine system

International Nuclear Information System (INIS)

Liao, Tianjun; Lin, Jian

2015-01-01

Graphical abstract: T–S diagram of the SHE cycle. - Highlights: • Based on Lagrange multiplier method, the optimal performance are investigated. • The energy balance between the absorber and the hot side of Stirling heat engine is considered. • The effects of major parameters on the optimal performance are investigated. - Abstract: A solar-driven Stirling heat engine system composed of a Stirling heat engine, a solar collector, and a heat sink is presented, in which the radiation and convection heat losses of the solar collector, the heat-leak between the thermal absorber and heat sink, the regenerative losses of the Stirling heat engine, and the energy balance between the thermal absorber and the high isothermal process of the Stirling heat engine are taken into consideration. Based on the irreversible thermodynamics and Lagrange multiplier method, the maximum power output and the corresponding optimal efficiency of the system are determined and the absorber temperature that maximizes the optimal system efficiency is calculated numerically. The influences of some system parameters such as the concentrating ratio, the volume ratio during the regenerative processes and irreversibilities of heat exchange processes on the optimal efficiency are analyzed in details. The results obtained here may provide a new idea to design practical solar-driven Stirling heat engine system

Solar heating, cooling, and hot water systems installed at Richland, Washington

Science.gov (United States)

1979-01-01

The project described is part of the U. S. Department of Energy's solar demonstration program, and became operational in April 1978. The solar system uses 6,000 square feet of flat-plate liquid collectors in a closed loop to deliver solar energy through a liquid-liquid heat exchanger to the building heat-pump duct work or 9,000-gallon thermal energy storage tank. A 25-ton Arkla solar-driven absorption chiller provides the cooling, in conjunction with a 2,000 gallon chilled water storage tank and reflective ponds on three sides of the building surplus heat. A near-by building is essentially identical except for having conventional heat-pump heating and cooling, and can serve as an experimental control. An on-going public relations program was provided from the beginning of the program, and resulted in numerous visitors and tour groups.

Flexibility of Large-Scale Solar Heating Plant with Heat Pump and Thermal Energy Storage

DEFF Research Database (Denmark)

Luc, Katarzyna Marta; Heller, Alfred; Rode, Carsten

2017-01-01

to decrease biomass use in a district heating system. The paper focuses on the renewable energy-based district heating system in Marstal, Denmark, with heat produced in central solar heating plant, wood pellet boiler, heat pump and bio-oil boiler. The plant has been the object of research and developments...

Tracking heat flux sensors for concentrating solar applications

Science.gov (United States)

Andraka, Charles E; Diver, Jr., Richard B

2013-06-11

Innovative tracking heat flux sensors located at or near the solar collector's focus for centering the concentrated image on a receiver assembly. With flux sensors mounted near a receiver's aperture, the flux gradient near the focus of a dish or trough collector can be used to precisely position the focused solar flux on the receiver. The heat flux sensors comprise two closely-coupled thermocouple junctions with opposing electrical polarity that are separated by a thermal resistor. This arrangement creates an electrical signal proportional to heat flux intensity, and largely independent of temperature. The sensors are thermally grounded to allow a temperature difference to develop across the thermal resistor, and are cooled by a heat sink to maintain an acceptable operating temperature.

Detection of bacteriophage phi 6 minus-strand RNA and novel mRNA isoconformers synthesized in vivo and in vitro, by strand-separating agarose gels

International Nuclear Information System (INIS)

Pagratis, N.; Revel, H.R.

1990-01-01

Two urea-free agarose gel protocols that resolve the six individual strands of bacteriophage phi 6 dsRNA were developed and used to analyze phage RNA synthesis in vivo and in vitro. Citrate gels separate strands of the large and medium chromosomes while Tris-borate-EDTA (TBE) gels resolve the medium and small dsRNA segments. Minus strands migrate faster than plus strands on citrate gels but are retarded on TBE gels. A study of electrophoretic conditions showed that pH affects strand resolution on citrate gels, and that voltage gradient, agarose concentration, and ethidium bromide significantly alter strand migration on TBE gels. Analysis of native phi 6 RNA synthesized in vivo and in vitro showed that the large and medium message RNAs comigrate with the corresponding plus strands of denatured virion dsRNA. The small messenger RNA is exceptional. Native small mRNA was detected as three isoconformers in vivo and in vitro. The isoconformers were converted by heat denaturation to a single RNA species that comigrates with the virion s+ strand. Minus strands labeled in vivo were detected only after heat denaturation. Minus strand synthesis was detected also in heat-denatured samples from in vitro phi 6 nucleocapsid RNA polymerase reactions at pH values suboptimal for transcription

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

The development of a solar residential heating and cooling system

Science.gov (United States)

1975-01-01

The MSFC solar heating and cooling facility was assembled to demonstrate the engineering feasibility of utilizing solar energy for heating and cooling buildings, to provide an engineering evaluation of the total system and the key subsystems, and to investigate areas of possible improvement in design and efficiency. The basic solar heating and cooling system utilizes a flat plate solar energy collector, a large water tank for thermal energy storage, heat exchangers for space heating, and an absorption cycle air conditioner for space cooling. A complete description of all systems is given. Development activities for this test system included assembly, checkout, operation, modification, and data analysis, all of which are discussed. Selected data analyses for the first 15 weeks of testing are included, findings associated with energy storage and the energy storage system are outlined, and conclusions resulting from test findings are provided. An evaluation of the data for summer operation indicates that the current system is capable of supplying an average of 50 percent of the thermal energy required to drive the air conditioner. Preliminary evaluation of data collected for operation in the heating mode during the winter indicates that nearly 100 percent of the thermal energy required for heating can be supplied by the system.

Potential for solar water heating in Zimbabwe

NARCIS (Netherlands)

Batidzirai, B.; Lysen, E.H.; van Egmond, S.; van Sark, W.G.J.H.M.

2009-01-01

This paper discusses the economic, social and environmental benefits from using solar water heating (SWH) in Zimbabwe. By comparing different water heating technology usage in three sectors over a 25-year period, the potential of SWH is demonstrated in alleviating energy and economic problems that

Solar heating system at Quitman County Bank, Marks, Mississippi. Final report

Energy Technology Data Exchange (ETDEWEB)

None

1980-06-01

Information is provided on the solar heating system installed in a single story wood frame, cedar exterior, sloped roof building, the Quitman County Bank, a branch of the First National Bank of Clarksdale, Mississippi. It is the first solar system in the geographical area and has promoted much interest. The system has on-site temperature and power measurements readouts. The 468 square feet of Solaron air flat plate collectors provide for 2000 square feet of space heating, an estimated 60% of the heating load. Solar heated air is distributed to the 235 cubic foot rock storage box or to the load (space heating) by a 960 cubic feet per minute air handler unit. A 7.5 ton Carrier air-to-air heat pump with 15 kilowatts of electric booster strips serve as a back-up (auxiliary) to the solar system. Motorized dampers control the direction of airflow and back draft dampers prevent thermal siphoning of conditioned air. The system was turned on in September 1979, and acceptance testing completed in February 1980. This is a Pon Cycle 3 Project with the Government sharing $13,445.00 of the $24,921 Solar Energy System installation cost.

Solar-heated swimming school--Wilmington, Delaware

Science.gov (United States)

1981-01-01

Report describes operation, installation, and performance of solar-energy system which provides alternative to natural gas pool heating. System is comprised of 2,500 square feet of liquid flat-plate collectors connected to 3,600 galloon; gallongalloon storage tank, with microcomputer-based controls. Extension of building incorporates vertical-wall, passive collection system which provides quarter of heated fresh air for office.

Proceedings of the solar industrial process heat symposium

Energy Technology Data Exchange (ETDEWEB)

None

1978-06-01

The purpose of the symposium was to review the progress of various solar energy systems currently under design for supplying industrial process heat. Formal presentations consisted of a review of solar energy applications in industrial process heat as well as several on-going project reviews. An Open Forum was held to solicit the comments of the participants. The recommendations of this Open Forum are included in these proceedings. Eighteen papers were included. Separate abstracts were prepared for each paper.

Design of annual storage solar space heating systems

Energy Technology Data Exchange (ETDEWEB)

Hooper, F C; Cook, J D

1979-11-01

Design considerations for annual storage solar space heating systems are discussed. A simulation model for the performance of suh systems is described, and a method of classifying system configurations is proposed. It is shown that annual systems sized for unconstrained performance, with no unused collector or storage capacity, and no rejected heat, minimize solar acquisition costs. The optimal performance corresponds to the condition where the marginal storage-to-collector sizing ratio is equal to the corresponding marginal cost ratio.

Simulation and experimental study of solar-absorption heat transformer integrating with two-stage high temperature vapor compression heat pump

Directory of Open Access Journals (Sweden)

Nattaporn Chaiyat

2014-11-01

Full Text Available In this study, simulation and experiment studies of a 10 kW solar H2O–LiBr absorption heat transformer (AHT integrating with a two-stage vapor compression heat pump (VCHP were carried out. The whole system was named as compression/absorption heat transformer (CAHT. The VCHP was used to recover rejected heat at the AHT condenser which was transferred back to the AHT evaporator at a higher temperature. The AHT unit took solar heat from a set of flat-plate solar collectors in parallel connection. R-134a and R-123 were refrigerants in the VCHP cycle. From the simulation, the total cycle coefficient (COP of the solar-CAHT was 0.71 compared with 0.49 of the normal solar-AHT. From the experiment, the total cycle COPs of the solar-CAHT and the solar-AHT were 0.62 and 0.39, respectively. The experimental results were lower than those of the simulated models due to the oversize of the experimental compressor. The annual expense of the solar-CAHT was found to be 5113 USD which was lower than 5418 USD of the solar-AHT. So it could be concluded that the modified unit was beneficial than the normal unit in terms of energy efficiency and economic expense.

Evaluation of inductive heating energy of sub-size improved DPC-C conductor by calorimetric method

International Nuclear Information System (INIS)

Ito, Toshinobu; Koizumi, Norikiyo; Wakabayashi, Hiroshi; Miura, Yuushi; Fujisaki, Hiroshi; Matsui, Kunihiro; Takahashi, Yoshikazu; Tsuji, Hiroshi

1996-08-01

The improved DPC-U conductor consisting of 648 chrome plated NbTi strands was fabricated and its stability has been investigated using 1/24 sub-size conductor. In the stability experiment, the inductive heating method was applied to originate initial normal zone. Since it is difficult to calculate the inductive heating energy deposited on the conductor because of complicate geometry of the twisted multi-strand cable, inductive heating energy had to be experimentally evaluated using calorimetric method. The heating energy is in proportion to integration of square of an applied sinusoidal wave pulsed current over the heating period. The experimental result shows the proportional constants for the conductor and conduit are 2.062 x 10 -3 [J/A 2 s] and 0.771 x 10 -3 [J/A 2 s], respectively. The coupling between the eddy currents in the strands and conduit might take effect on the heating energy put in the strands. It was shown this effect was however small in this experiment. Consequently, the inductive heating energy applied in the strands was estimated to be the proportional constant of 1.291 x 10 -3 [J/A 2 s] from the difference of the heat energies in the conductor and conduit. (author)

Electro-mechanical behaviors of composite superconducting strand with filament breakage

International Nuclear Information System (INIS)

Wang, Xu; Gao, Yuanwen; Zhou, Youhe

2016-01-01

Highlights: • The electromechanical behaviors of the superconducting (SC) strand are investigated. • A 3D FEM model for bending behaviors and electric properties of strand is developed. • The influence of breakage of filaments on the critical current of SC strand is calculated. • The impact of current transfer length on the electric properties of SC strand is discussed. - Abstract: The bending behaviors of superconducting strand with typical multi-filament twist configuration are investigated based on a three-dimensional finite element method (FEM) model, named as the Multi-filament twist model, of the strand. In this 3D FEM model, the impacts of initial thermal residual stress, filament-breakage and its evaluation are taken into accounts. The mechanical responses of the strand under bending load are studied with the factors taken into consideration one by one. The distribution of the damage of the filaments and its evolution and the movement of the neutral axis caused by it are studied and displayed in detail. Besides, taking the advantages of the Multi-filament twist model, the normalized critical current of the strand under bending load is also calculated based on the invariant temperature and field strain functions. In addition, the non-negligible influences of the pitch length of the filaments on both the mechanical behaviors and the normalized critical current are discussed. The stress-strain characteristics of the strand under tensile load and the normalized critical current of it under axial and bending loads resulting from the Multi-filament twist model show good agreement with the experimental data.

Electro-mechanical behaviors of composite superconducting strand with filament breakage

Energy Technology Data Exchange (ETDEWEB)

Wang, Xu [Key Laboratory of Mechanics on Environment and Disaster in Western China, The Ministry of Education of China, Lanzhou, Gansu 730000 (China); Department of Mechanics and Engineering Science, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou, Gansu 730000 (China); Gao, Yuanwen, E-mail: ywgao@lzu.edu.cn [Key Laboratory of Mechanics on Environment and Disaster in Western China, The Ministry of Education of China, Lanzhou, Gansu 730000 (China); Department of Mechanics and Engineering Science, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou, Gansu 730000 (China); Zhou, Youhe [Key Laboratory of Mechanics on Environment and Disaster in Western China, The Ministry of Education of China, Lanzhou, Gansu 730000 (China); Department of Mechanics and Engineering Science, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou, Gansu 730000 (China)

2016-10-15

Highlights: • The electromechanical behaviors of the superconducting (SC) strand are investigated. • A 3D FEM model for bending behaviors and electric properties of strand is developed. • The influence of breakage of filaments on the critical current of SC strand is calculated. • The impact of current transfer length on the electric properties of SC strand is discussed. - Abstract: The bending behaviors of superconducting strand with typical multi-filament twist configuration are investigated based on a three-dimensional finite element method (FEM) model, named as the Multi-filament twist model, of the strand. In this 3D FEM model, the impacts of initial thermal residual stress, filament-breakage and its evaluation are taken into accounts. The mechanical responses of the strand under bending load are studied with the factors taken into consideration one by one. The distribution of the damage of the filaments and its evolution and the movement of the neutral axis caused by it are studied and displayed in detail. Besides, taking the advantages of the Multi-filament twist model, the normalized critical current of the strand under bending load is also calculated based on the invariant temperature and field strain functions. In addition, the non-negligible influences of the pitch length of the filaments on both the mechanical behaviors and the normalized critical current are discussed. The stress-strain characteristics of the strand under tensile load and the normalized critical current of it under axial and bending loads resulting from the Multi-filament twist model show good agreement with the experimental data.

Innovative architecture design for high performance organic and hybrid multi-junction solar cells

Science.gov (United States)

Li, Ning; Spyropoulos, George D.; Brabec, Christoph J.

2017-08-01

The multi-junction concept is especially attractive for the photovoltaic (PV) research community owing to its potential to overcome the Schockley-Queisser limit of single-junction solar cells. Tremendous research interests are now focused on the development of high-performance absorbers and novel device architectures for emerging PV technologies, such as organic and perovskite PVs. It has been predicted that the multi-junction concept is able to boost the organic and perovskite PV technologies approaching the 20% and 30% benchmarks, respectively, showing a bright future of commercialization of the emerging PV technologies. In this contribution, we will demonstrate innovative architecture design for solution-processed, highly functional organic and hybrid multi-junction solar cells. A simple but elegant approach to fabricating organic and hybrid multi-junction solar cells will be introduced. By laminating single organic/hybrid solar cells together through an intermediate layer, the manufacturing cost and complexity of large-scale multi-junction solar cells can be significantly reduced. This smart approach to balancing the photocurrents as well as open circuit voltages in multi-junction solar cells will be demonstrated and discussed in detail.

Installation guidelines for Solar Heating System, single-family residence at New Castle, Pennsylvania

Energy Technology Data Exchange (ETDEWEB)

1980-01-01

The Solar Heating System installer guidelines are provided for each subsystem and includes testing and filling the system. This single-family residential heating system is a solar-assisted, hydronic-to-warm-air system with solar-assisted domestic water heating. It is composed of the following major components: liquid cooled flat plate collectors; water storage tank; passive solar-fired domestic water preheater; electric hot water heater; heat pump with electric backup; solar hot water coil unit; tube-and-shell heat exchanger, three pumps, and associated pipes and valving in an energy transport module; control system; and air-cooled heat purge unit. Information is also provided on the operating procedures, controls, caution requirements, and routine and schedule maintenance. Information consists of written procedures, schematics, detail drawings, pictures and manufacturer's component data.

The annual number of days that solar heated water satisfies a specified demand temperature

Energy Technology Data Exchange (ETDEWEB)

Yohanis, Y.G. [Thermal Systems Engineering Group, Faculty of Engineering, University of Ulster, BT37 0QB Northern Ireland (United Kingdom); Popel, O.; Frid, S.E. [Non-traditional Renewable Energy Sources, Institute for High Temperatures, Russian Academy of Sciences, 13/19 Izhorskaya str., IVTAN, Moscow 127412 (Russian Federation); Norton, B. [Dublin Institute of Technology, Aungier Street, Dublin 2 (Ireland)

2006-08-15

An analysis of solar water heating systems determines the number of days in each month when solar heated water wholly meets demand above a set temperature. The approach has been used to investigate the potential contribution to water heating loads of solar water heating in two UK locations. Correlations between the approach developed and the use of solar fractions are discussed. (author)

The entropy problem of the decentralized solar and nuclear heat generation

International Nuclear Information System (INIS)

Seifritz, W.

1984-01-01

Parallel to the energy fluxes the entropy fluxes of decentralized hot-water systems based on solar collectors coupled with an electrical auxiliary heating installation are also deduced. As an important result the fact emerges that this kind of solar energy has to remain very restricted, not only for quantitative-energetic reasons, but also for entropy ones, and that a solar hot-water system will always have to rely on an energy system of low entropy. In contrast to this, the provision of heat for space heating sector with the help of the 'nuclear short-distance concept', which practically does not need any external energy, is not subject to these restrictions. This concept is introduced briefly, as well as the heat prices which presumably can be achieved by it. Concluding comments summarize the reasons once again that speak against the installation of a decentralized solar heat supply system. (orig.) [de

Designing a solar powered Stirling heat engine based on multiple criteria: Maximized thermal efficiency and power

International Nuclear Information System (INIS)

Ahmadi, Mohammad Hossein; Sayyaadi, Hoseyn; Dehghani, Saeed; Hosseinzade, Hadi

2013-01-01

Highlights: • Thermodynamic model of a solar-dish Stirling engine was presented. • Thermal efficiency and output power of the engine were simultaneously maximized. • A final optimal solution was selected using several decision-making methods. • An optimal solution with least deviation from the ideal design was obtained. • Optimal solutions showed high sensitivity against variation of system parameters. - Abstract: A solar-powered high temperature differential Stirling engine was considered for optimization using multiple criteria. A thermal model was developed so that the output power and thermal efficiency of the solar Stirling system with finite rate of heat transfer, regenerative heat loss, conductive thermal bridging loss, finite regeneration process time and imperfect performance of the dish collector could be obtained. The output power and overall thermal efficiency were considered for simultaneous maximization. Multi-objective evolutionary algorithms (MOEAs) based on the NSGA-II algorithm were employed while the solar absorber temperature and the highest and lowest temperatures of the working fluid were considered the decision variables. The Pareto optimal frontier was obtained and a final optimal solution was also selected using various decision-making methods including the fuzzy Bellman–Zadeh, LINMAP and TOPSIS. It was found that multi-objective optimization could yield results with a relatively low deviation from the ideal solution in comparison to the conventional single objective approach. Furthermore, it was shown that, if the weight of thermal efficiency as one of the objective functions is considered to be greater than weight of the power objective, lower absorber temperature and low temperature ratio should be considered in the design of the Stirling engine

Solar water heating for aquaculture : optimizing design for sustainability

Energy Technology Data Exchange (ETDEWEB)

McDonald, M.; Thwaites, J. [Taylor Munro Energy Systems Inc., Delta, BC (Canada)

2003-08-01

This paper presents the results of a solar water heating project at Redfish Ranch, the first Tilapia tropical fish farm in British Columbia. The fish are raised in land-based tanks, eliminating the risk of contamination of local ecosystems. As a tropical species, they requires warm water. Natural gas or propane boilers are typically used to maintain tank temperatures at 26 to 28 degrees C. Redfish Ranch uses solar energy to add heat to the fish tanks, thereby reducing fossil-fuel combustion and greenhouse gas emissions. This unique building-integrated solar system is improving the environmental status of of this progressive industrial operation by offsetting fossil-fuel consumption. The system was relatively low cost, although substantial changes had to be made to the roof of the main building. The building-integrated design of the solar water heating system has reduced operating costs, generated local employment, and shows promise of future activity. As such, it satisfies the main criteria for sustainability. 7 refs.

The market penetration of solar and heat pump systems in Austria 1991

International Nuclear Information System (INIS)

Faninger, G.

1992-02-01

The market penetration of solar and heat pump systems in Austria in 1991 shows a high interest for solar systems as well as for swimming-pool heating as for domestic hot-water preparation and also an increase in the field of heat pumps especially for space heating. (author)

Thermo-economic Optimization of Solar Assisted Heating and Cooling (SAHC System

Directory of Open Access Journals (Sweden)

A. Ghafoor

2014-12-01

Full Text Available The energy demand for cooling is continuously increasing due to growing thermal loads, changing architectural modes of building, and especially due to occupants indoor comfort requirements resulting higher electricity demand notably during peak load hours. This increasing electricity demand is resulting higher primary energy consumption and emission of green house gases (GHG due to electricity generation from fossil fuels. An exciting alternative to reduce the peak electricity consumption is the possible utilization of solar heat to run thermally driven cooling machines instead of vapor compression machines utilizing high amount of electricity. In order to widen the use of solar collectors, they should also be used to contribute for sanitary hot water production and space heating. Pakistan lying on solar belt has a huge potential to utilize solar thermal heat for heating and cooling requirement because cooling is dominant throughout the year and the enormous amount of radiation availability provides an opportunity to use it for solar thermal driven cooling systems. The sensitivity analysis of solar assisted heating and cooling system has been carried out under climatic conditions of Faisalabad (Pakistan and its economic feasibility has been calculated using maximization of NPV. Both storage size and collector area has been optimized using different economic boundary conditions. Results show that optimum area of collector lies between 0.26m2 to 0.36m2 of collector area per m2 of conditioned area for ieff values of 4.5% to 0.5%. The optimum area of collector increases by decreasing effective interest rate resulting higher solar fraction. The NPV was found to be negative for all ieff values which shows that some incentives/subsidies are needed to be provided to make the system cost beneficial. Results also show that solar fraction space heating varies between 87 and 100% during heating season and solar fraction cooling between 55 and 100% during

Design concepts for solar heating in a Mediterranean climate

Energy Technology Data Exchange (ETDEWEB)

Schneider, M; Berger, X; Bourdeau, L; Jaffrin, A; Sylvain, J D

1977-01-01

Solar heating is often designed in a similar way to classical central heating. The consequence is a very high cost which can only be reduced by using a calorific fluid at a lower temperature than is customary, improved architectural design and a further research into new passive heating methods. The collection area and storage volume necessary to obtain good solar efficiency were computed in a Mediterranean climate. Emphasis is put on large thermal inertia which is best achieved by using the latent heat of materials. The result of an experiment performed with salt hydrates is most promising but many problems of time instability have still to be solved.

Review on advanced of solar assisted chemical heat pump dryer for agriculture produce

International Nuclear Information System (INIS)

Fadhel, M.I.; Sopian, K.; Daud, W.R.W.; Alghoul, M.A.

2011-01-01

Over the past three decades there has been nearly exponential growth in drying R and D on a global scale. Improving of the drying operation to save energy, improve product quality as well as reduce environmental effect remained as the main objectives of any development of drying system. A solar assisted chemical heat pump dryer is a new solar drying system, which have contributed to better cost-effectiveness and better quality dried products as well as saving energy. A solar collector is adapted to provide thermal energy in a reactor so a chemical reaction can take place. This reduces the dependency of the drying technology on fossil energy for heating. In this paper a review on advanced of solar assisted chemical heat pump dryer is presented (the system model and the results from experimental studies on the system performance are discussed). The review of heat pump dryers and solar assisted heat pump dryer is presented. Description of chemical heat pump types and the overview of chemical heat pump dryer are discussed. The combination of chemical heat pump and solar technology gives extra efficiency in utilizing energy. (author)

Performance of cylindrical plastic solar collectors for air heating

International Nuclear Information System (INIS)

Abdullah, A.S.; Bassiouny, M.K.

2014-01-01

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

Solar heating systems for heating and hot water

Energy Technology Data Exchange (ETDEWEB)

Schnaith, G; Dittrich, K

1980-07-01

Deutsche Bundesbahn has shown an interest in solar heating systems, too. The items discussed include the useful radiation energy, design features of collectors, heat carrier media, safeguards and profitability studies. The system installed by Deutsche Bundesbahn in the social services building of the Munich-Laim railway workshop is described. In conclusion, the test results of the first few months of service are given. In order to obtain unambiguous results, it appears indispensable to arrange for an additional total trial period of not less than two years and to conduct tests also on further systems presently under construction.

Modelling radiative heat transfer inside a basin type solar still

International Nuclear Information System (INIS)

Madhlopa, A.

2014-01-01

Radiative heat transfer inside a basin type solar still has been investigated using two models with (model 1) and without (model 2) taking into account optical view factors. The coefficient of radiative heat exchange (h r,w-gc ) between the water and cover surfaces of a practical solar still was computed using the two models. Simulation results show that model 1 yields lower values of h r,w-gc and the root mean square error than model 2. It is therefore concluded that the accuracy of modelling the performance of a basin-type solar still can be improved by incorporating view factors. - Highlights: • Radiative heat transfer in a basin type solar still has been investigated. • Two models with and without view factors were used. • The model with view factors exhibits a lower magnitude of root mean square error. • View factors affect the accuracy of modelling the performance of the solar still

Annual DOE active solar heating and cooling contractors' review meeting. Premeeting proceedings and project summaries

Energy Technology Data Exchange (ETDEWEB)

None,

1981-09-01

Ninety-three project summaries are presented which discuss the following aspects of active solar heating and cooling: Rankine solar cooling systems; absorption solar cooling systems; desiccant solar cooling systems; solar heat pump systems; solar hot water systems; special projects (such as the National Solar Data Network, hybrid solar thermal/photovoltaic applications, and heat transfer and water migration in soils); administrative/management support; and solar collector, storage, controls, analysis, and materials technology. (LEW)

Theoretical investigation of the performance of a novel loop heat pipe solar water heating system for use in Beijing, China

International Nuclear Information System (INIS)

Zhao Xudong; Wang Zhangyuan; Tang Qi

2010-01-01

A novel loop heat pipe (LHP) solar water heating system for typical apartment buildings in Beijing was designed to enable effective collection of solar heat, distance transport, and efficient conversion of solar heat into hot water. Taking consideration of the heat balances occurring in various parts of the loop, such as the solar absorber, heat pipe loop, heat exchanger and storage tank, a computer model was developed to investigate the thermal performance of the system. With the specified system structure, the efficiency of the solar system was found to be a function of its operational characteristics - working temperature of the loop heat pipe, water flow rate across the heat exchanger, and external parameters, including ambient temperature, temperature of water across the exchanger and solar radiation. The relationship between the efficiency of the system and these parameters was established, analysed and discussed in detail. The study suggested that the loop heat pipe should be operated at around 72 deg. C and the water across the heat exchanger should be maintained at 5.1 l/min. Any variation in system structure, i.e., glazing cover and height difference between the absorber and heat exchanger, would lead to different system performance. The glazing covers could be made using either borosilicate or polycarbonate, but borosilicate is to be preferred as it performs better and achieves higher efficiency at higher temperature operation. The height difference between the absorber and heat exchanger in the design was 1.9 m which is an adequate distance causing no constraint to heat pipe heat transfer. These simulation results were validated with the primary testing results.

Comparison of performance between a parallel and a series solar-heat pump system; Solar heat pump system ni okeru heiretsu setsuzoku no seino hikaku

Energy Technology Data Exchange (ETDEWEB)

Kanayama, K; Zhao, J; Baba, H; Endo, N [Kitami Institute of Technology, Hokkaido (Japan)

1997-11-25

In a solar heat pump system, a single-tank system was fabricated, in which a heat pump is installed in series between a heat collecting tank and a heat storage tank. At the same time, a double-tank system was also fabricated, in which two tanks are assembled into one to which a solar system and a heat pump are connected in parallel. Performance of both systems was analyzed by using measured values and estimated values. Heat collecting efficiency in the double-tank system is higher by about 13 points than in the single-tank system. Nevertheless, the coefficient of performance for the single-tank system is 1.03 to 1.51 times greater than that of the double-tank system. Dependency of the single-tank system on natural energy is higher by 0.3 to 3 points than the double-tank system. Putting the above facts together, it may be said that the single-tank system connecting the solar system and the heat pump in parallel is superior in performance to the double-tank system of the series connection. 3 refs., 5 figs., 2 tabs.

SOLAR HEAT TRANSFER THROUGH HDPC AND COPPER PIPE USING DIFFERENT FLUIDS

OpenAIRE

Muzamil Wani*, Karan Negi, Prince Mehandiratta

2016-01-01

Nowadays climate of growing energy needs and increasing environmental concern, alternatives to the use of non -renewable and polluting fossil fuels have to be investigated. One such alternative is solar energy; solar water heating is the prime application of solar energy. The problem faced by the existing solar water heating system is periodic inspections, maintenance, time to time component may need repair or replacement and also sufficient quantity of hot water is not available during clou...

Mathematical modelling and simulation of the thermal performance of a solar heated indoor swimming pool

Directory of Open Access Journals (Sweden)

Mančić Marko V.

2014-01-01

Full Text Available Buildings with indoor swimming pools have a large energy footprint. The source of major energy loss is the swimming pool hall where air humidity is increased by evaporation from the pool water surface. This increases energy consumption for heating and ventilation of the pool hall, fresh water supply loss and heat demand for pool water heating. In this paper, a mathematical model of the swimming pool was made to assess energy demands of an indoor swimming pool building. The mathematical model of the swimming pool is used with the created multi-zone building model in TRNSYS software to determine pool hall energy demand and pool losses. Energy loss for pool water and pool hall heating and ventilation are analyzed for different target pool water and air temperatures. The simulation showed that pool water heating accounts for around 22%, whereas heating and ventilation of the pool hall for around 60% of the total pool hall heat demand. With a change of preset controller air and water temperatures in simulations, evaporation loss was in the range 46-54% of the total pool losses. A solar thermal sanitary hot water system was modelled and simulated to analyze it's potential for energy savings of the presented demand side model. The simulation showed that up to 87% of water heating demands could be met by the solar thermal system, while avoiding stagnation. [Projekat Ministarstva nauke Republike Srbije, br. III 42006: Research and development of energy and environmentally highly effective polygeneration systems based on using renewable energy sources

HYBRID INDIRECT SOLAR COOKER WITH LATENT HEAT STORAGE

OpenAIRE

Benazeer Hassan K. Ibrahim *, Victor Jose

2016-01-01

Solar cooking is the simplest, safest, most convenient way to cook food without consuming fuels or heating up the kitchen. All the conventional solar cooker designs have the disadvantage of inability to cook during off-shine and night hours.This disadvantage can be eliminated if the solar cooker is designed with thermal storage arrangement. In this paper, a hybrid solar cooker with evacuated tube collector and latent thermal storage unit and alternate electric heatingsource is simulated. The...

SOLAR ENERGY APPLICATION IN HOUSES HEATING SYSTEMS IN RUSSIA

Directory of Open Access Journals (Sweden)

Zhanna Mingaleva

2017-06-01

Full Text Available The solar energy is widely used around the world for electricity generation and heating systems in municipal services. But its use is complicated in the number of territories with uneven receipts of solar radiation on the earth’s surface and large number of cloudy days during a year. A hypothesis on the possibility of application of individual solar collectors for heating of houses in the number of cities of Russia has been tested. The existing designs of solar collectors and checking the possibility of their application in northern territories of Russia are investigated. The analysis was carried out taking into account features of relief and other climatic conditions of the Perm and Sverdlovsk regions. As the result of research, the basic recommended conditions for application of solar batteries in houses of the northern Russian cities have been resumed.

Solar water heating system for a lunar base

Science.gov (United States)

Somers, Richard E.; Haynes, R. Daniel

1992-01-01

An investigation of the feasibility of using a solar water heater for a lunar base is described. During the investigation, computer codes were developed to model the lunar base configuration, lunar orbit, and heating systems. Numerous collector geometries, orientation variations, and system options were identified and analyzed. The results indicate that the recommended solar water heater could provide 88 percent of the design load and would not require changes in the overall lunar base design. The system would give a 'safe-haven' water heating capability and use only 7 percent to 10 percent as much electricity as an electric heating system. As a result, a fixed position photovoltaic array can be reduced by 21 sq m.

Economic analyses of central solar heating systems with seasonal storage

Energy Technology Data Exchange (ETDEWEB)

Lund, P D; Keinonen, R.S.

1986-10-01

Economic optimization of large active community solar heating systems with annual thermal storage is discussed. The economic evaluation is based on a thermal performance simulation model employing one hour time steps and on detailed up-date data. Different system configurations and sub-system sizes have been considered. For Northern European weather conditions (60/sup 0/N) and with at least 400-500 residential units, the life-cycle cost of delivered solar heat was 6.5-7.5 c/kWh for 50% fraction of non-purchased energy. For a solar fraction of 70%, the solar energy price would be 8 c/kWh.

Method and equipment to utilize solar heat. [paraffin used as heat storage material

Energy Technology Data Exchange (ETDEWEB)

Poellein, H

1976-09-16

In this process, solar radiation is converted into heat by means of absorbers. The heat transferred to a liquid is led in forced circulation, first into a heat storage device and then into a water heater. The cooled-down liquid is rercirculated. The storage material used here is paraffin. A measuring and control device is provided to switch from periods with solar radiation to periods where only stored energy is consumed. This device consists of a photocell measuring the incoming sunlight and a temperarure sensor. The control system is put into operation by a combination of the two measured values. The heat accumulator consists of several elements connected in parallel. A control device makes sure that only one accumulator element at a time is part of the circuit. The absorbers, as usual, consists of the absorber plate proper and a cover plate.

Experimental Study of the Performance of Air Source Heat Pump Systems Assisted by Low-Temperature Solar-Heated Water

Directory of Open Access Journals (Sweden)

Jinshun Wu

2013-01-01

Full Text Available Due to the low temperatures, the heating efficiency of air source heat pump systems during the winter is very low. To address this problem, a low-temperature solar hot water system was added to a basic air source heat pump system. Several parameters were tested and analyzed. The heat collection efficiency of the solar collector was analyzed under low-temperature conditions. The factors that affect the performance of the heat pumps, such as the fluid temperature, pressure, and energy savings, were analyzed for cases where the solar energy auxiliary heat pump and the air source heat pump are used independently. The optimal heating temperature and the changes in the fluid temperature were determined. The influence of the compression ratio and the coefficient of performance (COP were investigated theoretically. The results revealed the parameters that are important to the performance of the system. Several measures for improving the COP of the heat pump units are provided for other applications and future research.

Optimal design of solar water heating systems | Alemu | Zede Journal

African Journals Online (AJOL)

Solar water heating systems are usually designed using simplified equation of annual efficiency of the heating system from solar radiation incident on the collector during the year and empirical values of annual efficiency. The pe1formance of the preliminary design is predicted by using either/chart method or by translate it ...

Status and prospect of solar heat for industrial processes in China

DEFF Research Database (Denmark)

jia, Teng; Huang, Junpeng; Li, Rui

2018-01-01

In the past decades, solar heat for industrial processes (SHIP) have been rapidly developed and applied, and also getting more attention in the world. China is still the largest energy consumer with industry accounting for almost 70% of total energy consumption. Low- and medium-temperature heat...... takes up 45% of process heat, holding 50%-70% of industrial energy consumption, which provides a favorable condition for solar application. China has built some demonstration projects to make industrial processes well integrated with solar heating systems. This paper briefly presents the status of China......'s energy consumption, integration of SHIP, as well as available solar technologies. 10 typical industrial sectors are selected to specifically describe their potential of SHIP. Moreover, 26 SHIP cases covering the 10 sectors in China are presented by field researches, with their capacity of energy saving...

Status and prospect of solar heat for industrial processes in China

DEFF Research Database (Denmark)

jia, Teng; Huang, Junpeng; Li, Rui

2017-01-01

In the past decades, solar heat for industrial processes (SHIP) have been rapidly developed and applied, and also getting more attention in the world. China is still the largest energy consumer with industry accounting for almost 70% of total energy consumption. Low- and medium-temperature heat...... takes up 45% of process heat, holding 50%-70% of industrial energy consumption, which provides a favorable condition for solar application. China has built some demonstration projects to make industrial processes well integrated with solar heating systems. This paper briefly presents the status of China......'s energy consumption, integration of SHIP, as well as available solar technologies. 10 typical industrial sectors are selected to specifically describe their potential of SHIP. Moreover, 26 SHIP cases covering the 10 sectors in China are presented by field researches, with their capacity of energy saving...

Solar pond for heating anaerobic digesters

International Nuclear Information System (INIS)

Song Kehui; Li Shensheng

1991-10-01

A theoretical analysis and numerical results calculated for solar pond heating anaerobic digesters in Beijing area in China are presented. The effect of temperature rise is evident and rather steady. 3 refs, 1 fig., 1 tab

THE USE OF PASSIVE SOLAR HEATING SYSTEMS AS PART OF THE PASSIVE HOUSE

Directory of Open Access Journals (Sweden)

Bryzgalin Vladislav Viktorovich

2018-05-01

Full Text Available Subject: systems of passive solar heating, which can, without the use of engineering equipment, capture and accumulate the solar heat used for heating buildings. Research objectives: study of the possibility to reach the passive house standard (buildings with near zero energy consumption for heating in climatic conditions of Russia using the systems of passive solar heating in combination with other solutions for reduction of energy costs of building developed in the past. Materials and methods: search and analysis of literature, containing descriptions of various passive solar heating systems, examples of their use in different climatic conditions and the resulting effect obtained from their use; analysis of thermophysical processes occurring in these systems. Results: we revealed the potential of using the solar heating systems in the climatic conditions of parts of the territories of the Russian Federation, identified the possibility of cheaper construction by the passive house standard with the use of these systems. Conclusions: more detailed analysis of thermophysical and other processes that take place in passive solar heating systems is required for creation of their computational models, which will allow us to more accurately predict their effectiveness and seek the most cost-effective design solutions, and include them in the list of means for achieving the passive house standard.

A solar air collector with integrated latent heat thermal storage

Directory of Open Access Journals (Sweden)

Klimes Lubomir

2012-04-01

Full Text Available Simulations of the behaviour of a solar air collector with integrated latent heat thermal storage were performed. The model of the collector was created with the use of coupling between TRNSYS 17 and MATLAB. Latent heat storage (Phase Change Material - PCM was integrated with the solar absorber. The model of the latent heat storage absorber was created in MATLAB and the model of the solar air collector itself was created in TRNSYS with the use of TYPE 56. The model of the latent heat storage absorber allows specification of the PCM properties as well as other parameters. The simulated air collector was the front and back pass collector with the absorber in the middle of the air cavity. Two variants were considered for comparison; the light-weight absorber made of sheet metal and the heat-storage absorber with the PCM. Simulations were performed for the climatic conditions of the Czech Republic (using TMY weather data.

Experimental investigations on solar heating/heat pump systems for single family houses

DEFF Research Database (Denmark)

Andersen, Elsa; Perers, Bengt

In the period 2013-2017 the project “Experimental investigations on solar heat pump systems for single family houses” is carried out at Department of Civil Engineering, Technical University of Denmark. The aim of this project is to increase the knowledge of the heat and mass transfer in the combi...

SOLTECH 92 proceedings: Solar Process Heat Program

Energy Technology Data Exchange (ETDEWEB)

1992-03-01

This document is a limited Proceedings, documenting the presentations given at the symposia conducted by the US Department of Energy's (DOE) Solar Industrial Program and Solar Thermal Electrical Program at SOLTECH92. The SOLTECH92 national solar energy conference was held in Albuquerque, New Mexico during the period February 17--20, 1992. The National Renewable Energy Laboratory manages the Solar Industrial Program; Sandia National Laboratories (Albuquerque) manages the Solar Thermal Electric Program. The symposia sessions were as follows: (1) Solar Industrial Program and Solar Thermal Electric Program Overviews, (2) Solar Process Heat Applications, (3) Solar Decontamination of Water and Soil; (4) Solar Building Technologies, (5) Solar Thermal Electric Systems, (6) PV Applications and Technologies. For each presentation given in these symposia, these Proceedings provide a one- to two-page abstract and copies of the viewgraphs and/or 35mm slides utilized by the speaker. Some speakers provided additional materials in the interest of completeness. The materials presented in this document were not subjected to a peer review process.

Technical Analysis of Combined Solar Water Heating Systems for Cold Climate Regions

OpenAIRE

Hossein Lotfizadeh; André McDonald; Amit Kumar

2016-01-01

Renewable energy resources, which can supplement space and water heating for residential buildings, can have a noticeable impact on natural gas consumption and air pollution. This study considers a technical analysis of a combined solar water heating system with evacuated tube solar collectors for different solar coverage, ranging from 20% to 100% of the total roof area of a typical residential building located in Edmonton, Alberta, Canada. The alternative heating systems were conventional (n...

Development of 12.5 m² Solar Collector Panel for Solar Heating Plants

DEFF Research Database (Denmark)

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

2004-01-01

and large solar heating systems. Based on the theoretical findings a prototype of an improved HT solar collector was built and tested side-by-side with the original HT solar collector. The improved HT collector makes use of a changed insulation material, an absorber with improved absorptance and emittance......Theoretical and experimental investigations have elucidated how different changes in the design of the 12.5 m(2) HT flat-plate solar collector from the Danish company ARCON Solvarme A/S influence the solar collector efficiency and the yearly thermal performance. The collector is designed for medium...

Some characteristics of heat production by stationary parabolic, cylindrical solar concentrator

Energy Technology Data Exchange (ETDEWEB)

Bojic, M.; Marjanovic, N.; Miletic, I.; Mitic, A. [Kragujevac Univ., Kragujevac (Serbia). Faculty of Mechanical Engineering; Stefanovic, V. [Nis Univ., Nis (Serbia). Faculty of Mechanical Engineering

2009-07-01

The use of solar energy for heating, cooling and electricity production was discussed with particular reference to the use of a stationary, asymmetric solar concentrator for conversion of solar energy to heat using a reflector and absorber. The infinite length CP-0A type stationary parabolic, cylindrical solar concentrator for heat production consists of the absorber (with water pipes) and parabolic, cylindrical reflector (with a metal surface). It has a geometrical concentration ratio of up to 4. This paper reported on a study that used the CATIA computer software to investigate how direct solar radiation approaches the concentrator aperture and the concentrator reflector. The propagation of light rays inside the concentrator to reach the absorber surface was examined. The study showed that the solar ray either hits the absorber directly or it bounces one or several time from the concentrator reflector. The efficiency of light rays was also calculated as a function of angles of incident of solar rays and type of reflector surface. 5 refs., 8 figs.

System performance and economic analysis of solar-assisted cooling/heating system

KAUST Repository

Huang, B.J.; Wu, J.H.; Yen, R.H.; Wang, J.H.; Hsu, H.Y.; Hsia, C.J.; Yen, C.W.; Chang, J.M.

2011-01-01

The long-term system simulation and economic analysis of solar-assisted cooling/heating system (SACH-2) was carried out in order to find an economical design. The solar heat driven ejector cooling system (ECS) is used to provide part of the cooling

Application of porous medium for efficiency improvement of a concentrated solar air heating system

Science.gov (United States)

Prasartkaew, Boonrit

2018-01-01

The objective of this study is to evaluate the thermal efficiency of a concentrated solar collector for a high temperature air heating system. The proposed system consists of a 25-m2 focused multi-flat-mirror solar heliostat equipped with a porous medium solar collector/receiver which was installed on the top of a 3-m tower, called ‘tower receiver’. To know how the system efficiency cloud be improved by using porous medium, the proposed system with and without porous medium were tested and the comparative study was performed. The experimental results reveal that, for the proposed system, application of porous medium is promising, the efficiency can be increased about 2 times compared to the conventional one. In addition, due to the porous medium used in this study was the waste material with very low cost. It can be summarized that the substantial efficiency improvement with very low investment cost of the proposed system seem to be a vital measures for addressing the energy issues.

Solar heating system installed at Jackson, Tennessee. Final report

Energy Technology Data Exchange (ETDEWEB)

None

1980-10-01

The solar energy heating system installed at the Coca-Cola Bottling Works in Jackson, Tennessee is described. The system consists of 9480 square feet of Owens-Illinois evacuated tubular solar collectors with attached specular cylindrical reflectors and will provide space heating for the 70,000 square foot production building in the winter, and hot water for the bottle washing equipment the remainder of the year. Component specifications and engineering drawings are included. (WHK)

Water heating solar system for popular houses; Sistema solar de aquecimento de agua para residencias populares

Energy Technology Data Exchange (ETDEWEB)

Mogawer, Tamer; Souza, Teofilo Miguel de [Universidade Estadual Paulista (UNESP), Guaratingueta, SP (Brazil). Centro de Energias Renovaveis], e-mail: teofilo@feg.unesp.br

2004-07-01

In this paper we present a case study for the design of a low cost solar heating system for a popular residence in an isolated rural community in the state of Rio Grande do Norte. This scaling can be extended to several rural communities that are in the same situation in Brazil as well as the wider use of solar power between the low-income people who do not have the benefits of electricity in their homes or want to have a lower cost of electricity. In this context, there are very interesting alternatives, among which is the replacement of electric heating bath water by heating by solar energy. According to several sources the electric shower, as it is now simple and extremely cheap, is the villain of the national electrical system. It is used in peak hours of consumption, something like 10% of electric generating capacity installed in Brazil, forcing many industries to switch off the machines because of the high cost of electricity during this period. Using the heating by solar energy, we can reduce consumption of electric shower and also increase the use of clean energy in popular homes and in isolated rural communities. This paper will address the use of solar energy with the basic purpose of heating water for bathing in popular residences and in isolated rural areas, using low cost systems, built with easily materials that is found in any area of the country. (author)

Development of an integrated heat pipe-thermal storage system for a solar receiver

Science.gov (United States)

Keddy, E. S.; Sena, J. T.; Merrigan, M. A.; Heidenreich, G.; Johnson, S.

1987-01-01

The Organic Rankine Cycle (ORC) Solar Dynamic Power System (SDPS) is one of the candidates for Space Station prime power application. In the low Earth orbit of the Space Station approximately 34 minutes of the 94-minute orbital period is spent in eclipse with no solar energy input to the power system. For this period the SDPS will use thermal energy storage (TES) material to provide a constant power output. An integrated heat-pipe thermal storage receiver system is being developed as part of the ORC-SDPS solar receiver. This system incorporates potassium heat pipe elements to absorb and transfer the solar energy within the receiver cavity. The heat pipes contain the TES canisters within the potassium vapor space with the toluene heater tube used as the condenser region of the heat pipe. During the insolation period of the Earth orbit, solar energy is delivered to the heat pipe in the ORC-SDPS receiver cavity. The heat pipe transforms the non-uniform solar flux incident in the heat pipe surface within the receiver cavity to an essentially uniform flux at the potassium vapor condensation interface in the heat pipe. During solar insolation, part of the thermal energy is delivered to the heater tube and the balance is stored in the TES units. During the eclipse period of the orbit, the balance stored in the TES units is transferred by the potassium vapor to the toluene heater tube.

Development of an integrated heat pipe-thermal storage system for a solar receiver

Science.gov (United States)

Keddy, E. S.; Sena, J. T.; Merrigan, M. A.; Heidenreich, G.; Johnson, S.

1987-07-01

The Organic Rankine Cycle (ORC) Solar Dynamic Power System (SDPS) is one of the candidates for Space Station prime power application. In the low Earth orbit of the Space Station approximately 34 minutes of the 94-minute orbital period is spent in eclipse with no solar energy input to the power system. For this period the SDPS will use thermal energy storage (TES) material to provide a constant power output. An integrated heat-pipe thermal storage receiver system is being developed as part of the ORC-SDPS solar receiver. This system incorporates potassium heat pipe elements to absorb and transfer the solar energy within the receiver cavity. The heat pipes contain the TES canisters within the potassium vapor space with the toluene heater tube used as the condenser region of the heat pipe. During the insolation period of the Earth orbit, solar energy is delivered to the heat pipe in the ORC-SDPS receiver cavity. The heat pipe transforms the non-uniform solar flux incident in the heat pipe surface within the receiver cavity to an essentially uniform flux at the potassium vapor condensation interface in the heat pipe. During solar insolation, part of the thermal energy is delivered to the heater tube and the balance is stored in the TES units. During the eclipse period of the orbit, the balance stored in the TES units is transferred by the potassium vapor to the toluene heater tube.

Basic principles of solar water heating

CSIR Research Space (South Africa)

Page-Shipp, RJ

1980-09-10

Full Text Available This article correctly reflects the principles of Solar Water Heating as they pertain to South African conditions. However, it was written in 1980 and the global energy situation has changed considerably. Furthermore, modern commercial units...

Distributed Nonstationary Heat Model of Two-Channel Solar Air Heater

International Nuclear Information System (INIS)

Klychev, Sh. I.; Bakhramov, S. A.; Ismanzhanov, A. I.; Tashiev, N.N.

2011-01-01

An algorithm for a distributed nonstationary heat model of a solar air heater (SAH) with two operating channels is presented. The model makes it possible to determine how the coolant temperature changes with time along the solar air heater channel by considering its main thermal and ambient parameters, as well as variations in efficiency. Examples of calculations are presented. It is shown that the time within which the mean-day efficiency of the solar air heater becomes stable is significantly higher than the time within which the coolant temperature reaches stable values. The model can be used for investigation of the performances of solar water-heating collectors. (authors)

FFT analysis of sensible-heat solar-dynamic receivers

Science.gov (United States)

Lund, Kurt O.

The use of solar dynamic receivers with sensible energy storage in single-phase materials is considered. The feasibility of single-phase designs with weight and thermal performance comparable to existing two-phase designs is addressed. Linearized heat transfer equations are formulated for the receiver heat storage, representing the periodic input solar flux as the sum of steady and oscillating distributions. The steady component is solved analytically to produce the desired receiver steady outlet gas temperature, and the FFT algorithm is applied to the oscillating components to obtain the amplitudes and mode shapes of the oscillating solid and gas temperatures. The results indicate that sensible-heat receiver designs with performance comparable to state-of-the-art two-phase receivers are available.

Design and functionality of a segmented heat-storage prototype utilizing stable supercooling of sodium acetate trihydrate in a solar heating system

DEFF Research Database (Denmark)

Englmair, Gerald; Moser, Christoph; Furbo, Simon

2018-01-01

acetate trihydrate composites to conserve the latent heat of fusion for long-term heat storage. A control strategy directed heat from a solar collector array to either the PCM storage or a water buffer storage. Several PCM units had to be charged in parallel when the solar collector output peaked at 16 k......A solar heating system with 22.4m2 of solar collectors, a heat storage prototype consisting of four 200 kg phase-change material (PCM) storage units, and a 735 L water tank was designed to improve solar heat supply in single-family houses. The PCM storage utilized stable supercooling of sodium......W. A single unit was charged with 27.4 kWh of heat within four hours on a sunny day, and the PCM temperature increased from 20 °C to 80 °C. The sensible heat from a single PCM unit was transferred to the water tank starting with about 32 kW of thermal power after it had fully melted at 80 °C. A mechanical...

Multi-kW solar arrays for Earth orbit applications

Science.gov (United States)

1985-01-01

The multi-kW solar array program is concerned with developing the technology required to enable the design of solar arrays required to power the missions of the 1990's. The present effort required the design of a modular solar array panel consisting of superstrate modules interconnected to provide the structural support for the solar cells. The effort was divided into two tasks: (1) superstrate solar array panel design, and (2) superstrate solar array panel-to-panel design. The primary objective was to systematically investigate critical areas of the transparent superstrate solar array and evaluate the flight capabilities of this low cost approach.

Solar-Radiation Heating as a Possible Heat Source for Dehydration of Hydrous Carbonaceous Chondrites

Science.gov (United States)

Nakamura, T.; Golabek, G.; Ohtsuka, K.; Matsuoka, M.

2017-07-01

We have calculated time-dependent temperature profiles of near surface layers of primitive Near Sun Asteroid (3200) Phaethon and found that solar radiation heating is a possible heat source for dehydration of carbonaceous chondrites.

Solar heating and cooling system installed at Leavenworth, Kansas

Science.gov (United States)

1980-01-01

A solar heating and cooling is described which is designed to furnish 90 percent of the overall heating load, 70 percent of the cooling load and 100 percent of the domestic hot water load. The building has two floors with a total of 12,000 square feet gross area. The system has 120 flat-plate liquid solar panels with a net area of 2,200 square feet. Five 3 ton Arkla solar assisted absorption units provide the cooling, in conjunction with a 3,000 gallon chilled water storage tank. Two 3,000 gallon storage tanks are provided with one designated for summer use, whereas both tanks are utilized during winter.

A simplified heat pump model for use in solar plus heat pump system simulation studies

DEFF Research Database (Denmark)

Perers, Bengt; Andersen, Elsa; Nordman, Roger

2012-01-01

Solar plus heat pump systems are often very complex in design, with sometimes special heat pump arrangements and control. Therefore detailed heat pump models can give very slow system simulations and still not so accurate results compared to real heat pump performance in a system. The idea here...

Multi-fluid Approach to High-frequency Waves in Plasmas. III. Nonlinear Regime and Plasma Heating

Science.gov (United States)

Martínez-Gómez, David; Soler, Roberto; Terradas, Jaume

2018-03-01

The multi-fluid modeling of high-frequency waves in partially ionized plasmas has shown that the behavior of magnetohydrodynamic waves in the linear regime is heavily influenced by the collisional interaction between the different species that form the plasma. Here, we go beyond linear theory and study large-amplitude waves in partially ionized plasmas using a nonlinear multi-fluid code. It is known that in fully ionized plasmas, nonlinear Alfvén waves generate density and pressure perturbations. Those nonlinear effects are more pronounced for standing oscillations than for propagating waves. By means of numerical simulations and analytical approximations, we examine how the collisional interaction between ions and neutrals affects the nonlinear evolution. The friction due to collisions dissipates a fraction of the wave energy, which is transformed into heat and consequently raises the temperature of the plasma. As an application, we investigate frictional heating in a plasma with physical conditions akin to those in a quiescent solar prominence.

Synergistic effect of solar radiation and solar heating to disinfect drinking water sources.

Science.gov (United States)

Rijal, G K; Fujioka, R S

2001-01-01

Waterborne diseases are still common in developing countries as drinking water sources are contaminated and feasible means to reliably treat and disinfect these waters are not available. Many of these developing countries are in the tropical regions of the world where sunlight is plentiful. The objective of this study was to evaluate the effectiveness of combining solar radiation and solar heating to disinfect contaminated water using a modified Family Sol*Saver System (FSP). The non-UV transmittable cover sheet of the former FSP system was replaced with an UV transmittable plastic cover sheet to enable more wavelengths of sunlight to treat the water. Disinfection efficiency of both systems was evaluated based on reduction of the natural populations of faecal coliform, E. coli, enterococci, C. perfringens, total heterotrophic bacteria, hydrogen sulphide producing bacteria and FRNA virus. The results showed that under sunny and partly sunny conditions, water was heated to critical temperature (60 degrees C) in both the FSP systems inactivating more than 3 log (99.9%) of the concentrations of faecal coliform and E. coli to undetectable levels of heat worked synergistically to enhance the inactivation of faecal indicator bacteria. The relative log removal of indicator microorganism in the FSP treated water was total heterotrophic bacteria heat and radiation effects of sunlight were important in disinfecting water by solar units. The data indicated that direct radiation of sunlight worked synergistically with solar heating of the water to disinfect the water. Thus, effective disinfection was observed even when the water temperature did not reach 60 degrees C. Finally, the hydrogen sulphide test is a simple and reliable test that householders can use to determine whether their water had been sufficiently disinfected.

Feasibility Study on Solar District Heating in China

DEFF Research Database (Denmark)

Huang, Junpeng; Fan, Jianhua; Furbo, Simon

This paper analyzes the feasibility of developing solar district heating (SDH) in China from the perspective of incentive policy, selections of technical route, regional adaptability and economic feasibility for clean heating. Based on the analyzation, this proposes a road map for the development...

Heat-rejection design for large concentrating solar arrays

Science.gov (United States)

French, E. P.

1980-01-01

This paper considers the effect of heat rejection devices (radiators) on the performance and cost of large concentrating solar arrays for space application. Overall array characteristics are derived from the weight, cost, and performance of four major components; namely primary structure, optics/secondary structure, radiator, and solar panel. An ideal concentrator analysis is used to establish general cost and performance trends independent of specific array design. Both passive and heat-pipe radiation are evaluated, with an incremental cost-of-power approach used in the evaluation. Passive radiators are found to be more cost effective with silicon than with gallium arsenide (GaAs) arrays. Representative concentrating arrays have been evaluated for both near-term and advanced solar cell technology. Minimum cost of power is achieved at geometric concentration ratios in the range 2 to 6.

Research programme 'Active Solar Energy Use - Solar Heating and Heat Storage'. Activities and projects 2003; Programme 'Solaire actif - Chaleur et Stockage de chaleur'. Activites et projets en 2003

Energy Technology Data Exchange (ETDEWEB)

Hadorn, J.-C. [Base Consultants, Geneva (Switzerland); Renaud, P. [Planair SA, La Sagne (Switzerland)

2003-07-01

In this report by the research, development and demonstration (RD+D) programme coordinators the objectives, activities and main results in the area of solar heating and heat storage in Switzerland are presented for 2003. In a stagnating market environment the strategy of the Swiss Federal Office of Energy mainly consists in improving the quality and durability of solar collectors and materials, optimizing combisystems for space heating and domestic hot water preparation, searching for storage systems with a higher energy storage density than in the case of sensible heat storage in water, developing coloured solar collectors for more architectonic freedom, and finalizing a seasonal heat storage project for 100 dwellings to demonstrate the feasibility of solar fractions larger than 50% in apartment houses. Support was granted to the Swiss Testing Facility SPF in Rapperswil as in previous years; SPF was the first European testing institute to perform solar collector labeling according to the new rules of the 'Solar Keymark', introduced in cooperation with the European Committee for Standardization CEN. Several 2003 projects were conducted within the framework of the Solar Heating and Cooling Programme of the International Energy Agency IEA. Computerized simulation tools were improved. With the aim of jointly producing high-temperature heat and electric power a solar installation including a concentrating collector and a thermodynamic machine based on a Rankine cycle is still being developed. Seasonal underground heat storage was studied in detail by means of a validated computer simulation programme. Design guidelines were obtained for such a storage used in the summer time for cooling and in the winter time for space heating via a heat pump: depending on the ratio 'summer cooling / winter heating', cooling requires a cooling machine, or direct cooling without such a machine is possible. The report ends up with the list of all supported RD

Low-Cost Solar Water Heating Research and Development Roadmap

Energy Technology Data Exchange (ETDEWEB)

Hudon, K.; Merrigan, T.; Burch, J.; Maguire, J.

2012-08-01

The market environment for solar water heating technology has changed substantially with the successful introduction of heat pump water heaters (HPWHs). The addition of this energy-efficient technology to the market increases direct competition with solar water heaters (SWHs) for available energy savings. It is therefore essential to understand which segment of the market is best suited for HPWHs and focus the development of innovative, low-cost SWHs in the market segment where the largest opportunities exist. To evaluate cost and performance tradeoffs between high performance hot water heating systems, annual energy simulations were run using the program, TRNSYS, and analysis was performed to compare the energy savings associated with HPWH and SWH technologies to conventional methods of water heating.

Solar heating and cooling of residential buildings: design of systems, 1980 edition

Energy Technology Data Exchange (ETDEWEB)

None

1980-09-01

This manual was prepared primarily for use in conducting a practical training course on the design of solar heating and cooling systems for residential and small office buildings, but may also be useful as a general reference text. The content level is appropriate for persons with different and varied backgrounds, although it is assumed that readers possess a basic understanding of heating, ventilating, and air-conditioning systems of conventional (non-solar) types. This edition is a revision of the manual with the same title, first printed and distributed by the US Government Printing Office in October 1977. The manual has been reorganized, new material has been added, and outdated information has been deleted. Only active solar systems are described. Liquid and air-heating solar systems for combined space and service water heating or service water heating are included. Furthermore, only systems with proven experience are discussed to any extent.

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

Science.gov (United States)

1980-01-01

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

Installation package for a solar heating and hot water system

Science.gov (United States)

1978-01-01

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

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

Science.gov (United States)

Azad, E.

2011-12-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2011-12-15

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

The NASA-Lewis/ERDA Solar Heating and Cooling Technology Program