Regulation of Energy Entering Into and Emitting out of Plastic Greenhouse
Regulacija ulazne i emitovane energije iz plastenika
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Author
Boroja, Mitar
Urosevic, Mirko
Zivkovic, Milovan
Komnenic, Vaso
Keywords
light polarizationpolaroids
liquid crystals
high-voltage cascades
polarizacija svetlosti
polaroidi
tečni kristali
visokonaponske kaskade
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Show full item recordAbstract
In both controlled spaces and plastic greenhouses it is essential to maintain the
optimum conditions for undisturbed development of growing plants. Energy of the sun
radiation reaching plastic greenhouses changes considerably in the course of the day.
This energy is basically smaller than potential radiation energy because of: ionization
and apsorption of gas in atmosphere, appearance of clouds and atmosphere pollution,
changes in air density caused by atmosphere pressure, changes in angle of lightrays fall
on transparent part of plastic greenhouse and so on. All these changes bring about
substantial variations on climate conditions in plastic greenhouses and cause negative
conditions for plants development. Thereby it is very important to regulate automatically
the energy entering into and emitting out of plastic greenhouses. One way of automatic
or manual regulation of both entering and emitting energy is the transmission through
polaroid foils.
Here are considered two possibilities of entering solar energy regulation into plastic
greenhouse as well as prevention of energy emission out of plastic greenhouses. The first
possibility is by polaroid foils, and the second one is by liquid crystals.
The quantity of transmitted energy into plastic greenhouse depend on polaroid foils
position in the first case, and on potential (voltage) discrepancy in the second case. U kontrolisanim prostorima kao i u plastenicima je veoma bitno održavati
optimalne uslove za nesmetani razvoj gajenih biljaka. Energija zračenja Sunca koja
dopire do plastenika znatno se menja u toku dana. Ona je znatno manja od potencijalne
energije zračenja zbog jonizacije i apsorpcije gasova u atmosferi, te pojave oblaka i
zagađenosti u atmosferi, zatim promene gustine vazduha zbog delovanja atmosferskog
pritiska, promene ugla padanja svetlosnih zraka na prozirni deo plastenika i td. Sve ove
promene uslovljavaju znatna variranja klimatskih uslove u plastenicima čime se stvarju
nepovoljni uslov za razvoj biljke. Zbog toga je veoma važno da se ulazna i emitovana
energija iz plastenika automatski reguliše. Jedan od načina automatske ili ručne
regulacije kako dozračne, tako i emitovane energije je transmisija energije kroz
polaroidne folije.
Razmatrane su dve mogućnosti regulacije ulazne solarne energije u plastenik, kao i
sprečavanje isijavanja energije iz plastenika. Prvi način je pomoću polaroidnih folija, a
drugi način je pomoću tečnih kristala.
Količina transmitovane energije u plastenik kao i količina isijane energije iz
plastenika zavisila bi od položaja polaroid folija u prvom slučaju, a od razlike potencijala
(napona) u drugom slučaju.