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Solar energy collector design
solids should not be abandoned as devices for capturing solar energy in a form capable of transfer to some chemical system. ( authors' abstract)
Threlkeld, J. L. & Jordan, R. C. "Solar radiation during cloudless days." Heat. Pip. Air CorM. 2 7 ( 2 ) : 117-22. February 1955. This paper presents the results of research on the incidence of solar and sky radiation during cloudless days on horizontal, south-facing vertical and south-facing tilted surfaces. Calculated curves based upon an assumed standard summer atmosphere and an assumed standard winter atmosphere are presented. Comparisons of the calculated curves with recorded clear day radiation measurements are made for Lincoln, Neb.; Madison, Wis.; Columbia, Mo.; Rapid City, S.D.; Nashville, Tenn.; and Blue Hill, Mass. (authors' abstract)
Symposium on High Temperature D a Tool for the Future, Berkeley, California, June 1956. Proceedings o[ the Symposium. Sponsored by Stanford Research Institute; University of California. Menlo Park, Calif., Stanfor Research Institute, ~.1956. 218 pp. These proceedings, covering three aspects of high temperature m methods for reaching high temperatures, materials for containing high temperatures, and processes occurring at high temperatures - - include, in addition to much valuable information of a general nature, two papers dealing in part with solar furnaces. In the paper "Images of very high temperature sources", Joseph Farber deals in passing with the sun and solar concentrators as a guide to the use of earthly sources. In "Some considerations for the selection of materials for containing high temperatures", Tibor Laszlo points out the advantages of the solar furnace in eliminating difficulties due to the container and environment materials. Illustrated.
Trombe, F~lix. "Composite mirrors of large area in particular for c o n c e n t r a t i n g solar energy." U.S. Patent 2,707,903. May 10, 1955. This patent deals with the construction of a large area, composite curved mirror, of the type used in large solar furnaces. Each of the elementary mirrors consists of an elastically deformable plate which is given, by mechanical deforming means, the shape of the corresponding portion of the theoretical surface of the large mirror. In this particular case, the theoretical surface is a paraboloid of revolution. The elementary mirrors, trapezoidal in shape, are mounted on a framework, as described in the patent, to form substantially the theoretical surface of the large mirror. Illustrated.
Tabor, H. "Selective radiation. I. Wavelength discrimination. II. Wavefront discrimination." Bull. Research Council o/Israel 5A(2): 119-34. January 1956. (Paper presented at the Tucson Conference on Solar Energy - - the Scientific Basis, October-November, 1955. ) I. Initial experiments have shown that it is possible to produce surfaces which appear black but which have low emissivities at temperatures of a few hundred degrees C. Such selective surfaces should make possible the construction of solar energy devices of high efficiency with little or no optical concentration being required. II. Because of the difference in form between direct solar radiation and thermal radiation from a heated body, it is possible, using optical principles, to construct a "solartrap" which will permit solar radiation to enter an enclosure while preventing thermal radiation from leaving it. Used as the cover of a flat plate solar'energy collector, it provides a low effective emissivity and hence permits higher collection temperatures. Used as a "window" for a sun-heated house, it provides a transparent wall of low overall heat transfer coefficient. (author's abstracts)
~"Self-regulating automatic heliostat reflecting mirror device." U.S. Patent 2,712,772. July 12, 1955. This invention is a device for maintaining a beam of rays, and in particular sun rays, in a fixed direction, giving a continuous and progressive adjustment without oscillation. A flat mirror (hellostar) is used to reflect the rays in a fixed direction; the power elements which give the heliostat the desired position in relation to the sun are operated by liquid under pressure. The feed of this liquid is controlled by a valve which is itself operated in response to currents supplied by photoelectric cells under the effect of the sun's rays. The flow rate of the liquid under pressure therefore depends on the intensity of the current supplied by the light-sensitive ceils. Illustrated. Trombe, Fdlix and Foex, Marc. "Prdparation de zircone pure par fusion alcaline du zircon au four solaire." Compt. Rend. 240( 11): 1225-27. March 14, 1955. (Preparation of pure zirconia by alkaline melting of zircon in the solar furnace.) Describes the extraction of zirconia (ZrO.o) from zircon (SiO,Zr) in the solar furnace of Montlouis, which permits temperatures high enough for alkaline melting without contamination of the product being treated.
"Solar energy collector design." lhid, 5C( 1 ): 527. December 1955. The possibility of making solar energy collectors of high efficiency by use of selective black surfaces has prompted a re-statement of the problem of collector design. By means of two parameters, the overall transmission efficiency and the cut-off intensity, it is possible to determine the performance of a collector under various conditions of use. The concept of retention efficiency permits the construction of generalized yearly average efficiency curves from which the influence of a change in some design parameter is quickly seen. Computations show that it should be possible to produce log pressure steam without optical concentration, and high pressure steam with a small degree of concentration. (author;s abstract) 4
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"Sur un nouveau procddd de traitement des mdtaux ~ l'aide de l'dnergie solaire." Compt. Rend. 240 ( 2 ) : 196-98. January 10, 1955. ( A new process for the treatment of metals by means of solar energy.) The authors describe the composition and construction of the refractory lining of a centrifugal furnace using solar energy to produce homogenous metal ingots. Illustrated.
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"Solar energy machines: e n g i n e e r i n g and economic aspects of the principle of selective radiation." Paper presented at the 5th W o r l d Power Conference, V i e n n a , 1 9 5 6 . 1 4 pp. The absorption of solar energy and its conversion to power by means of a heat engine have not been economically viable due to the low collection efficiency unless expensive optical concentration is employed. By use of the principles of selective radiation which permit the production of black surfaces of low effective emissivity --the efficiencyof collection can be improved, resulting in an overall improvement factor of about three, thus bringing the solar power station - - with superheating by fuel - - close to economic viability. Reference is made to the methods of computing collector efficiencies, in particular the yearly average. (author's abstract)
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Ward, G. T. "Performance of a flat-plate solar heat collector." Chart. Mech. Engr. (London) 2: 293-95. 1955. An orthodox flat-plate solar heat collector has been constructed which is capable of being manufactured cheaply on a large scale. A simple relation has been established between the efficiency of the collector, the plate temperature and the rate of insolation for constant rates of flow of circulating water. Performance charts have been constructed enabling an assessment m be made of the practicability of using solar energy in the tropics for the production of heat and power. (author's abstract)
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Threlkeld, J. L. & Jordan, R. C. "Solar radiation during cloudless days." Heat. Pip. Air CorM. 2 7 ( 2 ) : 117-22. February 1955. This paper presents the results of research on the incidence of solar and sky radiation during cloudless days on horizontal, south-facing vertical and south-facing tilted surfaces. Calculated curves based upon an assumed standard summer atmosphere and an assumed standard winter atmosphere are presented. Comparisons of the calculated curves with recorded clear day radiation measurements are made for Lincoln, Neb.; Madison, Wis.; Columbia, Mo.; Rapid City, S.D.; Nashville, Tenn.; and Blue Hill, Mass. (authors' abstract)
Symposium on High Temperature D a Tool for the Future, Berkeley, California, June 1956. Proceedings o[ the Symposium. Sponsored by Stanford Research Institute; University of California. Menlo Park, Calif., Stanfor Research Institute, ~.1956. 218 pp. These proceedings, covering three aspects of high temperature m methods for reaching high temperatures, materials for containing high temperatures, and processes occurring at high temperatures - - include, in addition to much valuable information of a general nature, two papers dealing in part with solar furnaces. In the paper "Images of very high temperature sources", Joseph Farber deals in passing with the sun and solar concentrators as a guide to the use of earthly sources. In "Some considerations for the selection of materials for containing high temperatures", Tibor Laszlo points out the advantages of the solar furnace in eliminating difficulties due to the container and environment materials. Illustrated.
Trombe, F~lix. "Composite mirrors of large area in particular for c o n c e n t r a t i n g solar energy." U.S. Patent 2,707,903. May 10, 1955. This patent deals with the construction of a large area, composite curved mirror, of the type used in large solar furnaces. Each of the elementary mirrors consists of an elastically deformable plate which is given, by mechanical deforming means, the shape of the corresponding portion of the theoretical surface of the large mirror. In this particular case, the theoretical surface is a paraboloid of revolution. The elementary mirrors, trapezoidal in shape, are mounted on a framework, as described in the patent, to form substantially the theoretical surface of the large mirror. Illustrated.
Tabor, H. "Selective radiation. I. Wavelength discrimination. II. Wavefront discrimination." Bull. Research Council o/Israel 5A(2): 119-34. January 1956. (Paper presented at the Tucson Conference on Solar Energy - - the Scientific Basis, October-November, 1955. ) I. Initial experiments have shown that it is possible to produce surfaces which appear black but which have low emissivities at temperatures of a few hundred degrees C. Such selective surfaces should make possible the construction of solar energy devices of high efficiency with little or no optical concentration being required. II. Because of the difference in form between direct solar radiation and thermal radiation from a heated body, it is possible, using optical principles, to construct a "solartrap" which will permit solar radiation to enter an enclosure while preventing thermal radiation from leaving it. Used as the cover of a flat plate solar'energy collector, it provides a low effective emissivity and hence permits higher collection temperatures. Used as a "window" for a sun-heated house, it provides a transparent wall of low overall heat transfer coefficient. (author's abstracts)
~"Self-regulating automatic heliostat reflecting mirror device." U.S. Patent 2,712,772. July 12, 1955. This invention is a device for maintaining a beam of rays, and in particular sun rays, in a fixed direction, giving a continuous and progressive adjustment without oscillation. A flat mirror (hellostar) is used to reflect the rays in a fixed direction; the power elements which give the heliostat the desired position in relation to the sun are operated by liquid under pressure. The feed of this liquid is controlled by a valve which is itself operated in response to currents supplied by photoelectric cells under the effect of the sun's rays. The flow rate of the liquid under pressure therefore depends on the intensity of the current supplied by the light-sensitive ceils. Illustrated. Trombe, Fdlix and Foex, Marc. "Prdparation de zircone pure par fusion alcaline du zircon au four solaire." Compt. Rend. 240( 11): 1225-27. March 14, 1955. (Preparation of pure zirconia by alkaline melting of zircon in the solar furnace.) Describes the extraction of zirconia (ZrO.o) from zircon (SiO,Zr) in the solar furnace of Montlouis, which permits temperatures high enough for alkaline melting without contamination of the product being treated.
"Solar energy collector design." lhid, 5C( 1 ): 527. December 1955. The possibility of making solar energy collectors of high efficiency by use of selective black surfaces has prompted a re-statement of the problem of collector design. By means of two parameters, the overall transmission efficiency and the cut-off intensity, it is possible to determine the performance of a collector under various conditions of use. The concept of retention efficiency permits the construction of generalized yearly average efficiency curves from which the influence of a change in some design parameter is quickly seen. Computations show that it should be possible to produce log pressure steam without optical concentration, and high pressure steam with a small degree of concentration. (author;s abstract) 4
#
4,
4*
"Sur un nouveau procddd de traitement des mdtaux ~ l'aide de l'dnergie solaire." Compt. Rend. 240 ( 2 ) : 196-98. January 10, 1955. ( A new process for the treatment of metals by means of solar energy.) The authors describe the composition and construction of the refractory lining of a centrifugal furnace using solar energy to produce homogenous metal ingots. Illustrated.
4
"Solar energy machines: e n g i n e e r i n g and economic aspects of the principle of selective radiation." Paper presented at the 5th W o r l d Power Conference, V i e n n a , 1 9 5 6 . 1 4 pp. The absorption of solar energy and its conversion to power by means of a heat engine have not been economically viable due to the low collection efficiency unless expensive optical concentration is employed. By use of the principles of selective radiation which permit the production of black surfaces of low effective emissivity --the efficiencyof collection can be improved, resulting in an overall improvement factor of about three, thus bringing the solar power station - - with superheating by fuel - - close to economic viability. Reference is made to the methods of computing collector efficiencies, in particular the yearly average. (author's abstract)
4
4
Ward, G. T. "Performance of a flat-plate solar heat collector." Chart. Mech. Engr. (London) 2: 293-95. 1955. An orthodox flat-plate solar heat collector has been constructed which is capable of being manufactured cheaply on a large scale. A simple relation has been established between the efficiency of the collector, the plate temperature and the rate of insolation for constant rates of flow of circulating water. Performance charts have been constructed enabling an assessment m be made of the practicability of using solar energy in the tropics for the production of heat and power. (author's abstract)
63