Optical radiations in the systems of sun power engineering
The Sun intones, in ancient tourney
With brother-spheres, a rival song,
Fulfilling its predestined journey,
With march of thunder moves along.
Faust by J. W. von Goethe
Generals. Systems of sun energy are the most promising type of renewable technologies, which will allow in the future getting the enormous amount of clean and sustainable energy. Ancient philosophers put the Sun onto first place in accordance with the role that it plays in the origin and supporting of life on Earth. The poets of all times devoted to the luminary the best poems, charmed to it grandeur. But today, without regard to unlimited possibilities of the use of sun radiation, the systems of the solar power engineering produce only insignificant part of energy in total balance of consumable electric and thermal energy. The main reason of such slow penetration of sun technologies onto the market – high cost of energy that is retained during many years and breaks the hearts of «power vegetarians», admirers and users of renewable energy in world. These negative factors stimulate the search of new revolutionary methods and technologies able to overcome the given obstacles.
The researchers of Nizhyn laboratories of scanning devices work on the development of new structures of sun power elements and systems which incarnate in one construction of possibility of optical concentrator and photo-electric sun module. These elements are based on resonance properties of active optical environments, more precisely, on resonance properties of atoms, molecules and other nanoparticles to take in and radiate quanta, as it is observed in optical quantum laser amplifiers. In the future an introduction of these laser elements will give possibility to create energy effective, concentrating and photosensitive elements, and also the powerful solar plants based on the use of new sun elements.
Today we execute calculations and do the analysis of kinetics of oscillating processes accompanying the resonance interaction of radiation of laser structures with atoms and molecules, using the active optical radiation control. Results demonstrate the possibility and efficiency of pumping of active optical environments by sun energy, in other words, excitation of their atoms, molecules and artificial nanostructures.
The results of researches are presented in the series of the articles by Vasil Sidorov from Nizhyn laboratories of scanning devices.
The first paper Optical radiations in the systems of sun power engineering is concerned with the radiations of bodies. The radiations of bodies have electromagnetic nature, posses by quantum and wave properties and are a form of electromagnetic energy. Natural and artificial sources radiate in continuous, bright-line and band spectrums. The basic parameters of the Sun as a radiant are his angular sizes, power and spectral parameters, and also the degree of their change on a surface.
The second paper Physical properties of solar and optical radiations in the descriptions of physical optics is devoted to the basic physical parameters and characteristics of optical radiations, in particular, time and spacious coherence, monochromaticity and polarization. The wave character of optical radiations shows up in the phenomena of diffraction and interference.
The third paper Propagation of optical radiations in the descriptions of geometrical optics concerns with the laws of propagation of optical radiations in natural and artificial environments in accordance with the principles of geometrical optics. The theory of geometrical optics is based on the laws of rectilinear propagation, independence of propagation and reversibility of motion of rays, reflection and refraction of radiation on the boundary of two environments.
The forth paper Interaction of optical radiations with the matter in the descriptions of quantum mechanics covers the corpuscular (quantum)) nature of light. The corpuscular properties of light show up in the quantum character of radiation and absorption of light, in particular, in the photo-electric effect,
The 5th and 6th papers are covering the themes Laser radiations in the systems of sun power engineering and Laser radiation control in the systems of sun e power engineering. The methods of radiation control and manipulation by such parameters as phase, intensity, polarization, modes of radiations are determined. The analysis of physics of transformation of energy of radiations into other types of energy at their interaction with the matter is conducted.
New concepts and useful methods are considered in the descriptions of physical optics, geometrical optics and quantum mechanics. The articles include a lot of pictures and formula, explaining the themes.
Information is useful for the developers and users of the systems of sun power engineering, and also for investors, working in industry of renewable energy sources.
Radiations of bodies. The radiations of bodies have electromagnetic nature and possess by quantum and wave properties. It is a form of electromagnetic energy. The quantum nature of radiations shows up at the radiations and absorptions of light, and also in the phenomenon of photoeffect, at which the acts of interaction of radiations and matter occur – of quanta and elementary particles. The wave nature shows up in the phenomena of diffraction, interference and polarization. The radiations are accompanied by transference of energy that is called energy of radiation. This energy is described by power parameters and characteristics.
Radiants can have continuous spectrum of radiation, bright-line spectrum of radiation and band spectrum of radiation. A continuous spectrum contains an unbroken sequence of frequencies. It is characteristic for thermal or temperature sources and is emitted by incandescent solids, liquids and compressed gases.
Line spectra are discontinuous lines produced by excited atoms and ions at transitions to a lower energy level.
The band spectrums are caused by rotatory and oscillating motions of molecules. The spectrums of this type are formed by superposition of a plenty of the close located spectral lines into the bars of a different width. Band spectra (closely grouped bands of lines) are characteristic for molecular gases or chemical compounds.
For description of spectral composition of radiation of source with a continuous spectrum the notion of spectral density of flux of radiations is used, and as a unit is accepted W/m.
From the point of view of reasons that cause the radiation, all sources can be divided onto the primaries, secondary and mixed. The radiation of primary sources is a result of transformation of some type of energy into energy of radiations. The radiations of the secondary sources show up at action of radiations of other sources. Most sources are mixed. They posses both own and secondary radiations.
According to the type of emitted radiations the sources are classified onto the thermal, in which the radiations are a consistence of their heating; luminescent, at which some type of energy, except for thermal, is transformed into the radiations, and mixed, for which is characteristic a presence simultaneously of thermal and luminescent radiations.
The radiations of thermal sources are causing by thermal motion of elementary particles (molecules, atoms and electrons) and larger well-organized spatial macrostructures (domains, gratings and molecular chainlets), composed from elementary particles that are linked between itself. These macrostructures are characterized by certain chemical composition and state of matter (solid, amorphous, liquid, gaseous and plasma). They are also found in a state of motion and definitely affects onto the composition and nature of eventual thermal radiations. Addition of oscillating, rotatory and forward moving motions of macroparticles and microparticles in thermal radiants causes complicated and chaotic spatial and spectral distribution of radiations. This distribution is described only by probabilistic or statistical characteristics. Emitted energy is taken in by other bodies, which are heated and also began to radiate, in other words, every body takes in and radiates energy. The nature of thermal radiations of bodies is described by the Plank’s laws (in a general case) and Vin`s law (in special cases).
The sun as a radiant. The basic parameters of the Sun as an emitter are: angular sizes, power and spectral parameters and characteristics, and also the degree of their change on a surface.
The visible angular diameter of the Sun in the average is equal about 32' or 1/107 radian. The diameter of the Sun is equal approximately
Structurally the all Sun can be divided into 4 parts: central part or kernel lies from center on a distance of approximately 1/3 radius of the Sun; radiative zone (distance from 1/3 to 2/3 radius); convective zone - from overhead part of radiative zone till about the most visible border of the Sun; atmosphere that begins at once after a convective zone and extends far outside the visible disk of the Sun.
A sun atmosphere also is divided into a few layers: photosphere (the deepest layer of atmosphere by a thickness of 200 -
The middle density of sun matter is equal near 1400 kg/m3, in the kernel of the Sun the density of gas is equal about 1,5·105 kg/m3, the pressure - about 2·1018 Pa, and temperature - about 15000000 K0. At such temperature of kernel the atoms of hydrogen have high speeds and can collide one with other, causing the nuclear reactions – formation of helium from hydrogen with the formation of a plenty of heat. The stream of energy from center spreads into external layers.
In a radiative zone the energy is passed outside from one layer to another as a result of successive absorptions and radiations of quanta of electromagnetic energy.
In a convective zone a temperature is diminished with approaching to the visible border of luminary, as a result, the concentration of neutral atoms is multiplied, the radiative transfer slows down, and a heat is passed due to convection.
In a photosphere a temperature goes down with the removal from center, changing approximately from 8000 to 4000 C0. In the highest layers of photosphere a temperature is equal about
In a chromosphere a temperature grows again to tens and hundreds of thousands of Kelvin’s. Hydrogen, helium and other elements are consistently ionized.
A corona has the temperature of sun gases about 106 -
Solar radiation – the energy, formed as a result of thermonuclear reactions that flow in the body of the Sun. during those reactions the one types of particles grow into others. Complete energy of the Sun is equal ~2х1030 kg. Every second in the Sun near 6х1011 kg of hydrogen grow into helium. The defect of mass here is about
The distribution of intensity of sun radiation outside an earthly atmosphere is approximated by distribution of intensity of radiation of absolute black body (ABB) at a temperature of 5800 0К.
A sun constant is the amount of sun electromagnetic radiations on unit of the area, measured on the external surface of earthly atmosphere, perpendicularly to the rays. A sun constant includes at itself all types of radiations, not only visible light. She is measured by means of satellite and is equal approximately 1,366 W on a square meter (W/m2), although this value is changing within of 6,9% for a year (from 1,412 W/m2 at the beginning of January to 1,321 W/m2 at the beginning of July) in accordance with different remoteness of Earth from the Sun.
On the Earth the sun radiations fall as direct radiations without the change of direction of propagation and as diffuse radiations after the change of direction of propagation as a result of reflections and dispersions in an atmosphere. In the atmosphere of Earth there are two optical windows transparent for the radiations of 0,3…5,0 μm and 0,01…0,001 m.
Written by Vasil Sidorov on August 01,
Technopark QUELTA,
Nizhyn Laboratories of Scanning Devices
References
1. Rebrin Y.K., Sidorov V.I. //Optical Deflectors.
2. Rebrin Y.K., Sidorov V.I. Optical mechanical and holographic deflectors // Results in science and technology. Radio engineering. Vol. 45. -
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