Showing papers in "Journal of Solar Energy Engineering-transactions of The Asme in 1981"
TL;DR: In this paper, the authors present a solar energy handbook, where the authors discuss solar energy and its application in the field of renewable energy generation and renewable energy technologies, including the following:
Abstract: Solar energy handbook , Solar energy handbook , کتابخانه دیجیتالی دانشگاه علوم پزشکی و خدمات درمانی شهید بهشتی
255 citations
TL;DR: In this paper, the authors present techniques and theories covering the design and management of thermal energy storage systems in the areas of heat recovery and in circumstances where energy availability does not coincide chronologically with demand are presented.
Abstract: The newest techniques and theories covering the design and management of thermal energy storage systems in the areas of heat recovery and in circumstances where energy availability does not coincide chronologically with demand are presented. Techniques that predict the performance of sensible heat storage units in a broad range of operating conditions and methods for designing energy storage units for a variety of applications are covered comprehensively. The single blow problem of gas passing through heat-storing packing continuously in one direction is discussed. Solutions to this problem facilitate the control of the drying or cooling of beds of grain, other food stuffs, and industrial granular or powder products. These same solutions are applicable to the crucial issues of heat storage capabilities of particular construction in buildings and thermal stores built into solar collectors. Detailed information is included about counterflow regenerators including finite conductivity and nonlinear models. New concepts in computational methodology, parallel flow regenerators, heat storage exchangers, and packed beds are also covered. The optimization of prediction of heat storage systems and useful engineering correlations for thermal and hydraulic aspects of storage unit design are presented and explained in detail.
214 citations
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126 citations
TL;DR: In this article, two separate one-dimensional analyses have been developed for the prediction of the thermal and electrical performance of both liquid and air flat-plate photovoltaic/thermal (PV/T) collectors.
Abstract: Two separate one-dimensional analyses have been developed for the prediction of the thermal and electrical performance of both liquid and air flat-plate photovoltaic/thermal (PV/T) collectors. The analyses account for the temperature difference between the primary insolation absorber (the photovoltaic cells) and the secondary absorber (a thermal absorber flat plate). The results of the analyses are compared with test measurements, and therefrom, design recommendations are made to maximize the total energy extracted from the collectors.
120 citations
TL;DR: In this article, the effect of the choice of shape and dimensions of the air flow passages in plate-type, air-heating solar collectors is assessed, and their effect on the overall heat transfer coefficient between the air stream and the plate is discussed.
Abstract: The effect of the choice of shape and dimensions of the air flow passages in plate-type, air-heating solar collectors is assessed. Particular examination is made of their effect on the overall heat transfer coefficient between the air stream and the plate, which has an important effect on collector efficiency. It is emphasized in this study that in comparing various designs of flow passage, they should be compared for the same pressure drop suffered by the air in passing through the collector, and for the same mass flow rate m per unit of collector area. 11 refs.
114 citations
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30 citations
TL;DR: In this paper, an account is given of the construction and 1.5 years of operation of the Miamisburg, Ohio salt-gradient solar pond which, with 2020 sq m, is the largest solar collector in the U.S. The 18% sodium chloride solution pond has reached storage temperatures of 64 C in July and 28 C in February.
Abstract: An account is given of the construction and 1.5 years of operation of the Miamisburg, Ohio salt-gradient solar pond which, with 2020 sq m, is the largest solar collector in the U.S. The 18% sodium chloride solution pond has reached storage temperatures of 64 C in July and 28 C in February. Under steady-state conditions, conservative heat-yield estimates on the order of 962 million Btu have been made. The heat is used to warm-up a summer outdoor swimming pool and in winter a recreational building. Installation costs were only $35/sq m, and heat costs based on a 15-year depreciation of installation costs is below that of fuel oil heating, at $9.45 per million Btu. Further study is recommended for maintenance of water clarity, metallic component corrosion and assurance of pond water containment.
25 citations
TL;DR: The Central Receiver Test Facility (CRTF) operated for the Department of Energy by Sandia Laboratories in Albuquerque, NM was constructed for the purpose of evaluating solar central receiver design concepts.
Abstract: The Central Receiver Test Facility (CRTF) operated for the Department of Energy by Sandia Laboratories in Albuquerque, NM was constructed for the purpose of evaluating solar central receiver design concepts. At this facility working experience with the CRTF heliostat field has been gained and an extensive heliostat evaluation capability has evolved. Valuable information has been gained at the CRTF that will help in the future design and specification of heliostats. This paper summarizes the work that led to the current state of heliostat evaluation capability and includes a description of the CRTF heliostat, measurements of environmental degradation of mirror reflectance, heliostat beam measurements with an instrumented sweeping bar, beam quality and tracking accuracy data obtained with the newly developed Beam Characterization System (BCS) and comparisons of measured beam data with the heliostat computer model HELIOS.
TL;DR: In this article, a double-diffusive, thermohaline system has been studied under laboratory conditions involving uniform heating from below, and shadowgraph visualization has been used with temperature and salt concentration measurements to investigate mixing layer development and the onset of diffusion layer instabilities.
Abstract: A double-diffusive, thermohaline system has been studied under laboratory conditions involving uniform heating from below. Shadowgraph visualization has been used with temperature and salt concentration measurements to investigate mixing layer development and the onset of diffusion layer instabilities. Such instabilities were observed to occur in two of the experiments and were approximately predicted by an existing stability criterion. 17 refs.
TL;DR: In this paper, the authors compare a simple, one-dimensional model to the measured temperature stratification in a horizontal storage tank and find that axial temperature gradients were negligible compared to vertical temperature gradient.
Abstract: The thermal behavior of a horizontal storage tank has been investigated numerically and experimentally. The purpose of this paper is to compare a simple, one-dimensional model to the measured temperature stratification in this horizontal tank. For the test conditions used in these experiments, axial temperature gradients were found to be negligible compared to vertical temperature gradients. 7 refs.
TL;DR: In this paper, the flat plate collector fluid flow rate is determined for several combinations of objective functions and system models, and the method of implementing the control strategy for one of the problems considered, that which maximizes the integral of the difference between the collected solar power and fluid moving power, is described.
Abstract: The optimal flat plate collector fluid flow rate is determined for several combinations of objective functions and system models. The method of implementing the control strategy for one of the problems considered, that which maximizes the integral of the difference between the collected solar power and fluid moving power, is described. The performance of the solar energy collection system in Solar House II at Colorado State University using this optimal controller is discussed and compared with the same system using bang-bang control. In addition, the dependence of the collector efficiency factor on flow rate is considered and its effect on the optimal control is determined.
TL;DR: In this article, a two-equation turbulence model is used to predict numerically the flow within the tower of a tornado-type wind energy system, and the results for a closed-bottom tower and simulated turbine flow with a variety of turbine-to-tower diameter ratios and turbine flow rates are considered.
Abstract: A two-equation turbulence model is used to predict numerically the flow within the tower of a tornado-type wind energy system. Calculations are carried out for a tower in a uniform flow. Both cases of closed-bottom tower and simulated turbine flow with a variety of turbine-to-tower diameter ratios and turbine flow rates are considered. Calculated values of pressure for closed-bottom tower are compared with experimental values. 11 refs.
Abstract: A hybrid double-absorption system using LiCl-H/sub 2/O solution as a working fluid is proposed in this paper. This system can operate at low source temperature (55-80/degree/C), requires lower blower power than a desiccant system, and has a higher system C.O.P. A modification of this system, a double absorption-evaporation system that provides even higher C.O.P. is also proposed. 16 refs.
TL;DR: In this paper, thermal performance measurements of eight types of liquid-heating flat-plate solar collectors were conducted with two to four collectors of each type at four outdoor test sites in accordance with the procedure prescribed by ASHRAE Standard 93-77.
Abstract: Thermal performance measurements of eight types of liquid-heating flat-plate solar collectors were conducted with two to four collectors of each type at four outdoor test sites. Tests were performed in accordance with the procedure prescribed by ASHRAE Standard 93-77. Statistical analysis of data sets for each collector type within test sites and between test sites was done using ASTM recommended methods to evaluate test method measurement uncertainty.
TL;DR: In this paper, various aspects of glass encapsulation are treated that are important for the designer of photovoltaic systems, including the types of glass, sources, prices, physical properties and glass modifications, such as antireflection coatings.
Abstract: In photovoltaic systems, the encapsulant material that protects the solar cells should be highly transparent and very durable. Glass satisfies these two criteria and is considered a primary candidate for low-cost, photovoltaic encapsulation systems. In this paper, various aspects of glass encapsulation are treated that are important for the designer of photovoltaic systems. Candidate glasses and available information defining the state of the art of glass encapsulation materials and processes for automated, high volume production of terrestrial photovoltaic devices and related applications are presented. The desired characteristics of glass encapsulation are (1) low degradation rates, (2) high transmittance, (3) high reliability, (4) low-cost, and (5) high annual production capacity. The glass design areas treated herein include the types of glass, sources, prices, physical properties and glass modifications, such as antireflection coatings.
TL;DR: In this article, the performance and cost of four 10-MWe solar thermal electric power plants sited in various regions of the continental United States were analyzed and a range for the forecast cost of conventional electricity by region and nationally over the next several decades was presented.
Abstract: This paper presents the performance and cost of four 10-MWe advanced solar thermal electric power plants sited in various regions of the continental United States. Each region has different insolation characteristics which result in varying collector field areas, plant performance, capital costs, and energy costs. The paraboloidal dish, central receiver, cylindrical parabolic trough, and compound parabolic concentrator (CPC) comprise the advanced concepts studied. This paper contains a discussion of the regional insolation data base, a description of the solar systems' performances and costs, and a presentation of a range for the forecast cost of conventional electricity by region and nationally over the next several decades.
TL;DR: In this article, an experimental method is described for simulating the useful energy supplied by collector arrays during tests of solar water heating systems using an electric heat source to simulate the absorbed solar energy in series with non-irradiated collectors.
Abstract: An experimental method is described for simulating the useful energy supplied by collector arrays during tests of solar water heating systems. The method uses an electric heat source to simulate the absorbed solar energy in series with nonirradiated collectors to simulate the concurrent heat losses. Expressions are developed for programming the heat source for collector arrays connected in parallel and series combinations with the heat source located either upstream or downstream from the nonirradiated array. The results of experiments to verify the performance of a nonirradiated array with a downstream electric heat source are presented. Day-long tests of a domestic solar hot water system with irradiated collectors were repeated using a nonirradiated array with a downstream heat source. 12 refs.
TL;DR: Theoretical calculations and experimental data on an evacuated tube solar collector with an air heat transfer medium are presented in this paper, where an air collector using uncoated evacuated tubes and a screen absorber are used to infer the effectiveness of the heat transfer between the absorber screen and the air flow.
Abstract: Theoretical calculations and experimental data on an evacuated tube solar collector with an air heat transfer medium are presented. The collector is a conventional flat plate design except that the front cover, instead of being made up of one or two sheets of flat glass, consists of a raft-like arrangement of evacuated glass tubes. The calculations indicate that an evacuated tube cover, together with a high heat transfer absorber, could give a solar collector with superior thermal performance. Experimental measurements are given for an air collector using uncoated evacuated tubes and a screen absorber. Results on internal temperatures are used to infer the effectiveness of the heat transfer between the absorber screen and the air flow. When account is taken of the measured absorber properties, the performance of the evacuated tube cover is in reasonable accord with the theory.