Solar Thermal Electric Power Systems Research Articles

Analytical modeling of parabolic linear collectors for solar power plant

An analytical model for the parabolic trough collector (PTC) having its absorber tubes fitted with serrated twisted tape inserts using therminol VP-1 as working fluid for high temperature applications in solar thermal electric power system was developed taking radiative terms into account. The model takes radiative terms into account, for the development of the mathematical expressions for collector efficiency factor, collector heat removal factor, outlet fluid temperature and thermal efficiency. A computer program in C++ language, based on mathematical models was developed, to estimate the temperature rise of fluid for evaluation of the performance of PTC under specified conditions. For numerical simulations, three different twist ratios, x = 1,2.5,4 and mass flow rates ranging from 0.06 kg/s to 0.16 kg/s (3000 ≤ Re ≤ 9000) and dimensionless insolation, Ψ(t) = 0.2 to 1.0 are used. This study demonstrates that twisted tape insert shows great promise for enhancing the performance of the PTC. The maximum value of outlet fluid temperature, useful heat gain and thermal efficiency are 452.52 K, 17711 W and 79.22 %, respectively for x = 1, Ψ(t) = 1.0 and mass flow rate of 0.16 kg/s.

International R & D collaboration in developing solar thermal technologies for electric power and solar chemistry : The solarPACES program of the International Energy Agency (IEA)

The SolarPACES program of the International Energy Agency, formed in 1977, now has members from 12 countries. Its R & D teams cooperate on three Tasks in a Strategic Plan: Solar Thermal Electric Power Systems, Solar Chemistry, and Solar Technology and Application. Electricity from solar thermal power plants has proven to be the most economical form of solar electricity (between half or one third of the price of that from photovoltaics). Examples of R & D activities in three solar thermal power technologies: parabolic troughs, power towers, dish/engine systems are given. Cooperation with industry, public uilities and international financing organizations is also outlined. Solar Chemistry, a rather young discipline, utilizes concentrating solar thermal technologies for R & D in solar production of energy carriers; solar processing of chemical commodities; solar detoxification and recycling of waste materials.

Optical performance and durability of solar reflectors protected by an alumina coating

Solar thermal electric power systems use large solar reflectors to concentrate sunlight to generate electricity. The economic viability of these systems depends on developing a durable, low-cost reflector. The goals for such a reflector are specular reflectance above 90% for at least 10 years under outdoor service conditions and a large-volume manufacturing cost of less than US$10.8/m 2 (US$1.00/ft 2). Currently, the best candidate materials for solar reflectors are silver-coated, low-iron glass and silvered polymer films. Polymer reflectors are lighter in weight, offer greater system design flexibility, and have the potential for lower cost than glass reflectors. A promising low-cost reflector consists of a silvered polymer protected by an optically transparent alumina coating. The coating is deposited by an ion-beam-assisted physical vapor deposition (IBAD) technique. Samples of this reflector have maintained high optical performance in accelerated testing for more than 3000 h. Solar reflectors produced using this technique may represent an opportunity to bring solar power generation to reality.

太陽熱エネルギー利用技術

The use of solar energy will be important among various energy sources if we consider the possible shortage of fossil fuels. Solar energy is abundant in quantity, free from pollution and safety. At present, it is considered that solar systems are inferior to other energy systems such as conventional fossil fuel and nuclear plants and have disadvantages in respect to the density of energy flux and energy cost.Solar energy mainly has been used in two fields which are solar thermal applications and photovoltaic power systems. The progress in solar thermal applications, such as solar heating and cooling systems for building, advanced heat process systems, solar thermal electric power systems, and hybrid photovoltaic/thermal systems in Japan is described.

Temperature Control of Line-Focus Solar Collectors

Solar thermal electric power and industrial process heat systems may require a constant outlet temperature from the collector. This temperature may be efficiently maintained by adjusting the circulating fluid flow rate. Using frequency response techniques, simple relations are developed which relate controller tuning constants to collector construction and field layout. Successful controller tuning is shown to be a compromise between good response at high flow rates and stability at low flow rates. The rules of thumb are then tested by performing dynamic numerical simulations of a collector row with flow rate control.

Analytical Dynamic Modeling of Line-Focus Solar Collectors

Solar thermal electric power and industrial process heat systems may require a constant outlet temperature from the collector field. This constant temperature is most efficiently maintained by adjusting the circulating fluid flow rate. Successful tuning of analog or digital controllers requires a knowledge of system dynamics. Models relating deviations in outlet temperature to changes in inlet temperature, insolation, and fluid flow rate illustrate the basic responses and the distributed-parameter nature of line-focus collectors. When plotted in dimensionless form, the frequency response of a given collector is essentially independent of the operating conditions, suggesting that feedback controller settings are directly related to such easily determined quantities as collector gain and fluid residence time.

Research and Development on Solar Thermal Electric Power System

Research and Development on Solar Thermal Electric Power System

Solar thermal electric power systems: Comparison of line-focus collectors

Three types of line-focusing collectors: parabolic though, fixed slats with movable absorber and movable slats with fixed absorber, are evaluated to find those systems that are capable of producing the lowest costs of electrical energy. Minimum costs per kW-hr are found using sequential optimization techniques that consider variations in rim angle, reflectance, aperture width, length, orientation, tracking, contour error, slat width, slat curvature, tangent slat angle, slope, installation methods, materials, fabrication methods, absorptance, emittance, cover transmittance, field shape, layout, pipe sizes, insulation thicknesses and turbine-generator-cooling lower efficiencies and designs. This approach provides a uniform treatment of both cost and performance for a solar thermal electric power system. This uniform treatment of solar thermal electric power systems for all collector types insures that valid comparisons are made.

Solar thermal electric power systems: Manufacturing cost estimation and systems optimization

Since the spring of 1973, the faculty of the School of Engineering at Colorado State University has hasn engaged in studies to estimate minimum cost systems for generating electric power by solar thermal means. These studies have been financed by the National Science Foundation and the Energy Research and Development Administration. The effort has consisted primarily of estimating the costs of large-volume manufacture of components of candidate systems and developing procedures whereby these complex, inter-related components are synthesized into minimum cost systems. This paper describes the approaches used in estimating the manufacturing costs of the system components, describes the procedure developed to find systems optima, illustrates key results and presents the minimum cost designs, makes cost comparisons with present and future methods of electric power generation, and points out what can be done to help make solar electric power generation a more viable alternative.

Study of solar thermal electric power system (effect of selective thin barrier on radiative heat transfer)

Electrical Engineering in JapanVolume 97, Issue 2 p. 57-63 Article Study of solar thermal electric power system (effect of selective thin barrier on radiative heat transfer) Tadayoshi Tanaka, Tadayoshi Tanaka Electrotechnical LaboratorySearch for more papers by this authorTakashi Horigome, Takashi Horigome Electrotechnical LaboratorySearch for more papers by this authorTatuo Tani, Tatuo Tani Electrotechnical LaboratorySearch for more papers by this authorShinji Sawada, Shinji Sawada Electrotechnical LaboratorySearch for more papers by this authorKoichi Sakuta, Koichi Sakuta Electrotechnical LaboratorySearch for more papers by this author Tadayoshi Tanaka, Tadayoshi Tanaka Electrotechnical LaboratorySearch for more papers by this authorTakashi Horigome, Takashi Horigome Electrotechnical LaboratorySearch for more papers by this authorTatuo Tani, Tatuo Tani Electrotechnical LaboratorySearch for more papers by this authorShinji Sawada, Shinji Sawada Electrotechnical LaboratorySearch for more papers by this authorKoichi Sakuta, Koichi Sakuta Electrotechnical LaboratorySearch for more papers by this author First published: 1977 https://doi.org/10.1002/eej.4390970208AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Volume97, Issue21977Pages 57-63 RelatedInformation

太陽熱発電システムの研究(コレクタにおける選択透過膜と伝熱面材の役割の評価)

太陽熱発電システムの研究(コレクタにおける選択透過膜と伝熱面材の役割の評価)

A terrestrial solar thermal electric power system—Development of basic model system

A model system of a distributed collector power system was constructed at the Electrotechnical Laboratory, Tanashi, Tokyo, Japan in the summer of 1975. This model system consisted of a cylindrical parabolic concentrator, heat transfer loop and storage-type heat exchanger and has been used for evaluating the system performance and the dynamic characteristics of each subsystem and the whole system. This paper presents the performance of each subsystem used in the model system and summarizes results obtained from tests made on the whole system.

MINIMUM COST SOLAR THERMAL ELECTRIC POWER SYSTEMS: A DYNAMIC PROGRAMMING BASED APPROACH

A dynamic programming methodology is presented for finding minimum cost solar thermal electric power systems ’(STEPS). The objective of the study for which this technique was developed was to identify designs of STEPS concepts that were most promising in terms of projected cost per kilowatt hour of electricity generated.