RO134848A2

RO134848A2 - System for collecting solar energy

Info

Publication number: RO134848A2
Application number: RO201900592A
Authority: RO
Inventors: Virgiliu Brateanu; Radu Dumitru Badicescu
Original assignee: Termosolar Aktiv S.R.L.
Priority date: 2019-09-24
Filing date: 2019-09-24
Publication date: 2021-03-30

Abstract

The invention relates to a system for collecting solar energy in order to convert it into thermal energy while transferring the collected solar energy, with increased efficiency, to a fluid-based heating medium for storage or for direct utilization in a solar heating plant for industrial or domestic use. According to the invention, the system has a flat solar collector (1) comprising a framework (2), a first transparent panel (3) and a second transparent panel (3') which are parallel to each other and form together with the framework (2) a tight casing (1.1) wherein an absorbing element (5) is placed parallel to the panels (3 and 3') and spaced apart from them by at least two spacers (4 and 4'), the absorbing element (5) having a surface oriented towards the first transparent panel (3) and having fixed a black continuous flexible tube (6) in the shape of a coil wherethrough a heating medium may flow, the absorbing element (5) being a black flat metallic element having a plurality of orifices (7) partially permitting the incident solar rays to pass from the first panel (3) to the second panel (3'), where the panel (3') is provided on an internal surface oriented towards the absorbing element (5) with a low-e layer.

Description

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SISTEM PENTRU CAPTAREA ENERGIEI SOLARE ‘ , ·. 2 4 -09- 2019 ' Data depozit ........................SOLAR ENERGY CAPTURE SYSTEM ‘, ·. 2 4 -09- 2019 'Date of deposit ........................

DESCRIEREDESCRIPTION

[0001] Prezenta invenție se refera la un sistem pentru captarea energiei solare (colector solar), in vederea transformării acesteia in energie termica si transferul cu eficienta sporita, a energiei solare captate, către un agent termic, pe baza de fluid pentru a fi stocata sau utilizata direct intr-o instalație termica solara pentru uz domestic sau industrial, de exemplu pentru încălzirea apei calde menajere, a apei din piscine sau pentru încălzirea centrala avand rol dublu de captare a energiei solare si de ansamblu ce permite trecerea luminii intr-o incapere/incinta. In particular, prezenta invenție se refera la un colector solar plan si la un sistem ce include un astfel de colector solar plan.The present invention relates to a system for capturing solar energy (solar collector), in order to transform it into thermal energy and transfer with increased efficiency, the captured solar energy to a thermal agent, based on fluid to be stored. or used directly in a solar thermal installation for domestic or industrial use, for example for domestic hot water heating, pool water or for central heating having a dual role of capturing solar energy and overall that allows light to pass into a room / pregnant. In particular, the present invention relates to a planar solar collector and to a system including such a planar solar collector.

STADIUL TEHNICIISTATE OF THE ART

[0002] Un sistem pentru captarea energiei solare (denumit in mod uzual „colector solar”, „captator solar” sau “panou solar termic”) cuprinde, in general, o rama sau un cadru substanțial dreptunghiular in secțiune transversala. Prin „rama” sau „cadru”, in contextul prezentei invenții, se înțelege un schelet alcătuit din bare de lemn, de metal sau din alte materiale adecvate (de exemplu, materiale cu un coeficient liniar de conductivitate termica scăzut, cum ar fi materialele termoplastice), care se întrebuințează ca suport pentru diferite ansambluri, aparate sau produse. Colectorul solar mai cuprinde un panou exterior si un panou interior, din sticla transparenta care formează împreuna cu rama menționata o carcasa închisa ermetic in interiorul careia se afla montate celelalte elemente:A system for capturing solar energy (commonly referred to as a "solar collector", "solar collector" or "solar thermal panel") generally comprises a frame or a substantially rectangular frame in cross section. By "frame" or "frame", in the context of the present invention, is meant a frame made of wooden, metal or other suitable materials (for example, materials with a low linear coefficient of thermal conductivity, such as thermoplastics ), which is used as a support for various assemblies, devices or products. The solar collector also comprises an outer panel and an inner panel, made of transparent glass which together with the mentioned frame form a hermetically sealed housing inside which the other elements are mounted:

- o multitudine de tuburi sau țevi, susținute la capete de rama menționata si prin care circula agent termic (de exemplu: apa sau aer), atașate pe- a plurality of tubes or pipes, supported at the ends of said frame and through which thermal agent (for example: water or air) circulates, attached to

- un element absorbant (de exemplu: o placa metalica cu efect de absorbție a razelor solare). Elementul absorbant este un element ce capteaza si ulterior cedeaza energia calorica absorbita către agentul termic care circula prin tuburile menționate. Agentul termic inmagazineaza si apoi transporta energia calorica la utilizator sau la un recipient de stocare. Elementul absorbant este in general, poziționat perpendicular pe rama, intr-o poziție centrala in interiorul carcasei si paralel cu panourile din sticla transparenta. Intre elementul absorbant si panourile din sticla se formează spatii izolatoare termic (de exemplu, aer) prin intermediul unor distantiere. [0003] Cea mai raspandita si cunoscuta versiune a colectoarelor solare sunt colectoarele solare plane. Structura colectoarelor solare plane este in general compusa dintr-o carcasa ermetica in care cadrul este fabricat, in general, din aliajaluminiu. Panoul exterior este alcătuit dintr-o sticla speciala, de exemplu de 3.2 mm grosime, securizata, de înalta transparenta (cu conținut de fier scăzut). Sub panoul exterior din sticla este un element absorbant, de exemplu, o tabla albastra de absorbent din aluminiu cu înveliș selectiv. Elementul absorbant trebuie să capteze cat mai bine radiația solara, atat cea directa cat si cea difuza, si sa o transforme in căldură. In același timp, căldură cedata de elementul absorbant sub forma de radiație, sa fie pe cat posibil intr-o cantitate cat mai mica. In termeni tehnici aceasta inseamna ca trebuie sa se comporte selectiv fata de lungimile de unda corespunzătoare celor doua procese termice. Pe tabla de absorbent este fixata o serpentina din țeava de cupru sau aluminiu.- an absorbent element (for example: a metal plate with the effect of absorbing sunlight). The absorbent element is an element that captures and subsequently transfers the absorbed caloric energy to the thermal agent circulating through the mentioned tubes. The heating agent stores and then transports the heat energy to the user or to a storage container. The absorbent element is generally positioned perpendicular to the frame, in a central position inside the housing and parallel to the transparent glass panels. Thermally insulating spaces (eg air) are formed between the absorbent element and the glass panels by means of spacers. The most widespread and well-known version of solar collectors are flat solar collectors. The structure of flat solar collectors is generally composed of an airtight housing in which the frame is generally made of aluminum alloy. The outer panel is made of a special glass, for example 3.2 mm thick, secure, high transparency (low iron content). Under the outer glass panel is an absorbent element, for example, a blue aluminum absorbent sheet with selective coating. The absorbent element must capture as much as possible the solar radiation, both direct and diffuse, and turn it into heat. At the same time, the heat given off by the absorbent element in the form of radiation, to be as small as possible. In technical terms this means that it must behave selectively with respect to the wavelengths corresponding to the two thermal processes. A coil of copper or aluminum pipe is fixed on the absorbent sheet.

[0004] Funcționarea colectoarelor solare plane este destul de simpla: razele soarelui pătrund prin sticla securizata de înalta transparenta, ating elementul absorbant cu înveliș selectiv si se transforma in căldură. Energia termica rezultata nu se pierde, colectorul fiind izolat termic datorita carcasei ermetice. Aceasta energie termica este absorbita in interiorul colectorului, conducând la o temperatura mai înalta decât in situația fara panou exterior din sticla. Acest efect este cunoscut sub numele de “efect de sera”. La colectoarele solare moderne se utilizează sticla speciala, cu un conținut cat mai mic posibil de fier pentru a limita pierderile de căldură prin convectie si radiație. Elementul absorbant cedeaza apoi căldură agentului termic ce curge prin țeava de cupru sau aluminiu amplasata in dreptul sau pe suprafața acestuia. Agentul termic transporta energia termica la utilizator sau la un recipient de stocare.The operation of flat solar collectors is quite simple: the sun's rays penetrate through the highly transparent safety glass, touch the absorbent element with selective coating and turn into heat. The resulting thermal energy is not lost, the collector being thermally insulated due to the hermetic housing. This thermal energy is absorbed inside the collector, leading to a higher temperature than in the situation without a glass outer panel. This effect is known as the "greenhouse effect". Modern solar collectors use special glass, with the lowest possible iron content to limit heat loss through convection and radiation. The absorbent element then gives off heat to the thermal agent flowing through the copper or aluminum pipe located in front of or on its surface. The heating agent transports the thermal energy to the user or to a storage container.

[0005] Intr-adevar, se cunoaște faptul ca acea cantitate de căldură rezultata din conversie si cea captata de către suprafața de absorbție prin convectie are drept efect ridicarea temperaturii acesteia peste temperatura mediului ambiant. Datorita acestei diferente de temperatura apar pierderile termice si numeroase cercetări sunt dedicate reducerii acestora.Indeed, it is known that that amount of heat resulting from the conversion and that captured by the convection absorption surface has the effect of raising its temperature above ambient temperature. Due to this temperature difference, thermal losses occur and numerous researches are dedicated to reducing them.

[0006] Alte dezavantaje ale unor astfel de colectoare solare cunoscute sunt: complexitatea construcției, designul voluminos ce nu poate fi încadrat intr-o rama standardizata de fereastra sau usa a unei clădiri si costul mare de fabricare datorita materialelor speciale folosite.Other disadvantages of such known solar collectors are: the complexity of the construction, the bulky design that cannot be framed in a standardized frame of the window or door of a building and the high cost of manufacture due to the special materials used.

[0007] Se mai cunoaște un colector solar plan conform documentului CN101008306A, care este alcătuit dintr-un strat exterior din sticla, aflat in legătură cu un al doilea strat interior de sticla acoperit cu o placa de absorbție, cele doua straturi de sticla fiind fixate intr-o rama de fereastra, intre acestea fiind prevăzut un tub drept, pentru admisia apei reci si evacuarea apei calde la unul dintre capetele laterale ale ramei si mai multe tuburi pentru colectarea energiei solare, fixate pe al doilea strat exterior de sticla acoperit cu placa de absorbție si conectate la unul dintre capete la tubul drept. Colectorul solar mai cuprinde un material izolator aplicat pe tubul drept si un strat de aer intre stratul de sticla interior si cel exterior.There is also known a flat solar collector according to document CN101008306A, which consists of an outer layer of glass, connected to a second inner layer of glass covered with an absorption plate, the two layers of glass being fixed in a window frame, between them being provided a straight tube, for the admission of cold water and the evacuation of hot water at one of the lateral ends of the frame and several tubes for collecting solar energy, fixed on the second outer layer of glass covered with plate suction and connected at one end to the right tube. The solar collector also comprises an insulating material applied on the straight tube and an air layer between the inner and outer glass layer.

[0008] Avantajul acestui colector solar este ca poate fi ușor integrat in arhitectura unei clădiri fara a necesita spațiu suplimentar.The advantage of this solar collector is that it can be easily integrated into the architecture of a building without requiring additional space.

[0009] Totuși, exista cateva dezavantaje importante ale acestui colector solar si anume:However, there are some important disadvantages of this solar collector, namely:

- exista mai multe procese de transfer de căldură, fiecare cu un randament propriu, ceea ce reduce semnificativ raportul dintre energia termica utila înglobata in apa calda menajera si radiația solara incidența;- there are several heat transfer processes, each with its own efficiency, which significantly reduces the ratio between the useful thermal energy embedded in domestic hot water and the incidence of solar radiation;

- suprafața de schimb de căldură intre tuburile pentru colectarea energiei solare si tubul prin care circula agentul termic este relativ mica, reducandu-se proporțional si cantitatea de căldură transferata.- the heat exchange surface between the tubes for collecting solar energy and the tube through which the thermal agent circulates is relatively small, reducing proportionally the amount of heat transferred.

[0010] Un alt colector solar plan, conform documentului RO129671B1, cuprinde un perete exterior din sticla, care se afla in contact cu o placa de policarbonat celular transparent prin intermediul unui strat izolator termic, de preferat aer, aceasta placa fiind prevăzută cu niște canale longitudinale, cel puțin o parte dintre acestea fiind traversate de un tub flexibil continuu, de culoare neagra, sub forma unei serpentine prin care circula agentul termic. La partea opusa se afla un al doilea perete, interior, transparent, din sticla aflat in legătură cu un distantier.Another flat solar collector, according to document RO129671B1, comprises an outer wall of glass, which is in contact with a transparent cellular polycarbonate plate by means of a thermal insulating layer, preferably air, this plate being provided with some channels. longitudinal, at least part of which is crossed by a continuous flexible tube, black in the form of a coil through which the thermal agent flows. On the opposite side is a second wall, interior, transparent, made of glass connected to a spacer.

[0011] Avantajele principale ale acestui colector solar sunt:The main advantages of this solar collector are:

- mai puține procese de schimb de căldură, ceea ce creste semnificativ raportul dintre energia termica înglobata in apa calda produsa si radiația solara incidența;- fewer heat exchange processes, which significantly increases the ratio between the thermal energy embedded in the hot water produced and the incidence of solar radiation;

- suprafața de schimb de căldură, respectiv suprafața de contact dintre suprafața interioara a tubului negru si apa calda este mult mai mare decât la celelalte tipuri de colectoare solare, permițând astfel transferul unei cantitati mai mari de căldură.- the heat exchange surface, respectively the contact surface between the inner surface of the black tube and the hot water is much larger than the other types of solar collectors, thus allowing the transfer of a larger amount of heat.

[0012] Dezavantajele acestui colector solar sunt:The disadvantages of this solar collector are:

- radiația solara incidența traversează pe langa peretele exterior din sticla si peretele plăcii de policarbonat celular, ceea ce conduce la pierderi prin reflexie si refracție (pentru policarbonatul celular transmisia luminoasa este de aprox. 80% si indicele de refracție de aprox. 1,585%), reducandu-se raportul intre radiația incidența si energia termica utila înglobata in apa calda menajera, cu atat mai mult cu cat policarbonatul se opacizează in timp.- the incidence of solar radiation passes next to the outer glass wall and the wall of the cellular polycarbonate plate, which leads to losses by reflection and refraction (for cellular polycarbonate the light transmission is about 80% and the refractive index is about 1.585%), reducing the ratio between the incidence radiation and the useful thermal energy embedded in the domestic hot water, all the more so as the polycarbonate becomes opaque over time.

PREZENTAREA PROBLEMEI TEHNICEPRESENTATION OF THE TECHNICAL PROBLEM

[0013] Prin urmare, obiectivul prezentei invenții este furnizarea unui colector solar plan capabil sa asigure creșterea randamentului de conversie a energiei solare in energie termica avand in același timp, rol de colector solar si ansamblu ce permite trecerea luminii intr-o incapere/incinta.Therefore, the object of the present invention is to provide a planar solar collector capable of ensuring the increase of the conversion efficiency of solar energy into thermal energy having at the same time the role of solar collector and assembly that allows the passage of light in a room / enclosure.

[0014] Un alt obiectiv al prezentei invenții este furnizarea unui colector solar plan avand o construcție simplificata ce permite montajul in ramele de fereastra/usa standardizate.Another object of the present invention is to provide a planar solar collector having a simplified construction that allows mounting in standardized window / door frames.

[0015] Pentru a realiza aceste obiective, prezenta invenție are ca obiect un colector solar plan, conform revendicării 1, care cuprinde:In order to achieve these objectives, the present invention relates to a flat solar collector according to claim 1, comprising:

un cadru substanțial dreptunghiular in secțiune transversala;a substantially rectangular frame in cross section;

un prim panou transparent si un al doilea panou transparent, dispuse paralel unul fata de celalalt si care formează împreuna cu cadrul menționat, o carcasa ermetica cu o grosime, in interiorul careia se afla dispus, paralel cu panourile menționate si distantat fata de acestea, prin intermediul a cel puțin doua distantiere:a first transparent panel and a second transparent panel, arranged parallel to each other and forming together with said frame, an airtight housing with a thickness, inside which is arranged, parallel to said panels and spaced from them, by by means of at least two spacers:

o un element absorbant avand o suprafața orientata către primul panou transparent si pe care este fixat un tub flexibil, continuu, de culoare neagra, sub forma unei serpentine, prin care poate circula un agent termic;o an absorbent element having a surface oriented towards the first transparent panel and on which is fixed a flexible, continuous, black tube, in the form of a coil, through which a thermal agent can circulate;

o tubul menționat este prevăzut cu conexiuni de alimentare/evacuare a agentului termic la cate un capat al tubului, conectat la cadrul menționat, caracterizat prin aceea ca elementul absorbant este un element metalic plan, de culoare neagra, prevăzut cu o multitudine de orificii ce permit trecerea parțiala a razelor solare incidente dinspre primul panou transparent menționat către al doilea panou transparent menționat si prin aceea ca, al doilea panou transparent menționat are prevăzut, pe o suprafața interioara a acestuia, orientata către elementul absorbant menționat, un strat cu emisivitate scăzută (low-e).o said tube is provided with supply / discharge connections of the thermal agent at one end of the tube, connected to said frame, characterized in that the absorbent element is a flat, black metal element provided with a plurality of holes that allow the partial passage of the incident sunlight from said first transparent panel to said second transparent panel and in that the second said transparent panel has provided, on an inner surface thereof, oriented towards said absorbent element, a layer with low emissivity (low -e).

[0016] Colectorul solar plan conform prezentei invenții, prezintă următoarele avantaje in raport cu soluțiile tehnice existente in stadiul tehnicii:The flat solar collector according to the present invention has the following advantages in relation to the technical solutions existing in the prior art:

- creșterea randamentului de conversie al energiei solare in energie termica prin nivelul mărit de absorbție al radiației solare incidente, datorat utilizării unei suprafețe absorbante in combinație cu un strat cu emisivitate scăzută (low-e);- increasing the efficiency of conversion of solar energy into thermal energy through the increased level of absorption of incident solar radiation, due to the use of an absorbent surface in combination with a layer with low emissivity (low-e);

- reducerea pierderilor de căldură prin convectie si creșterea izolației termice a ansamblului ce permite trecerea luminii intr-o incapere/incinta, prin etansarea incintei colectorului solar plan conform invenției;- reducing the heat losses by convection and increasing the thermal insulation of the assembly that allows the passage of light in a room / enclosure, by sealing the enclosure of the flat solar collector according to the invention;

- combina rolul de colector solar si ansamblu ce permite trecerea luminii intr-o incapere/incinta;- combines the role of solar collector and assembly that allows the passage of light in a room / enclosure;

- are o construcție simplificata ce permite montajul in ramele standardizate de fereastra/usa, de exemplu termopan cu grosimea de 24 mm.- has a simplified construction that allows installation in standardized window / door frames, for example double glazing with a thickness of 24 mm.

DESCRIEREA PE SCURT A DESENELORBRIEF DESCRIPTION OF THE DRAWINGS

[0017] Alte obiective, avantaje si caracteristici ale invenției vor aparea in următoarea descriere a unui exemplu de realizare, care nu limitează obiectul si întinderea prezentei cereri de brevet, insotita de desene in care:Other objects, advantages and features of the invention will appear in the following description of an embodiment, which does not limit the object and scope of the present patent application, accompanied by drawings in which:

- figura 1 este o vedere in secțiune longitudinala A-A a colectorului solar plan conform unui prim exemplu de realizare conform invenției;- figure 1 is a view in longitudinal section A-A of the planar solar collector according to a first embodiment according to the invention;

- figura 2 este o vedere in secțiune transversala B-B a colectorului solar plan conform unui prim exemplu de realizare conform invenției.- figure 2 is a cross-sectional view B-B of the planar solar collector according to a first embodiment according to the invention.

DESCRIEREA DETALIATADETAILED DESCRIPTION

[0018] Referitor la figurile 1 și 2, este reprezentat un colector solar plan (1), prevăzut cu un cadru (2) substanțial dreptunghiular in secțiune transversala. Cadrul (2) poate fi confecționat din bare de lemn, de metal sau din alte materiale adecvate (de exemplu, materiale cu un coeficient liniar de conductivitate termica scăzut). Un exemplu preferat de realizare pentru acest cadru (2) este prin tehnologia “warm edge” (“margine calda” sau “bagheta termica”). Prin aceasta tehnologie se pastreaza calda marginea unitatii sigilate, in cazul prezentei invenții, a colectorului solar plan (1), reducând astfel cantitatea de căldură pierduta prin unitatea sigilata, de unde si denumirea de „margine calda”.Referring to Figures 1 and 2, there is shown a planar solar collector (1), provided with a frame (2) substantially rectangular in cross section. The frame (2) may be made of wooden, metal or other suitable materials (for example, materials with a low coefficient of thermal conductivity). A preferred embodiment for this frame (2) is by the “warm edge” technology (“hot edge” or “thermal rod”). By this technology, the edge of the sealed unit, in the case of the present invention, of the planar solar collector (1) is kept warm, thus reducing the amount of heat lost by the sealed unit, hence the name "hot edge".

[0019] In prezent, aceasta tehnologie se folosește cu precădere in procesul de fabricație a geamurilor termopan pentru a reduce fenomenul de conductie, astfel scazand cantitatea de căldură care se pierde prin marginile geamului termopan si pentru prevenirea formarii condensului pe marginile geamului, in sezonul rece. Barele de distanțare „margine calda”, folosite pentru fabricarea cadrului (2), conform invenției sunt confecționate dintr-un material compozit (de exemplu: termoplastic sau pe baza de silicon cu sita moleculara incorporata, policarbonati si polipropilena combinati cu adaosuri scăzute de metal), de preferința de 16 mm, bun izolant termic si fonic in comparație cu barele din metal, cum ar fi aluminiul. Prin folosirea acestei tehnologii de fabricare a cadrului (2) se obține o scădere a costului de fabricare cu aproximativ 30% decât daca s-ar fi folosit bare de metal sau lemn.Currently, this technology is mainly used in the manufacturing process of double-glazed windows to reduce the conduction phenomenon, thus reducing the amount of heat lost through the edges of double-glazed windows and to prevent the formation of condensation on the edges of the glass in the cold season. . The "hot edge" spacer bars used for the manufacture of the frame (2) according to the invention are made of a composite material (for example: thermoplastic or silicone-based with built-in molecular sieve, polycarbonate and polypropylene combined with low metal additives) , preferably 16 mm, good thermal and sound insulation compared to metal bars, such as aluminum. The use of this frame manufacturing technology (2) reduces the manufacturing cost by approximately 30% unless metal or wood bars were used.

[0020] Colectorul solar plan (1) mai cuprinde un prim panou (3) transparent si un al doilea panou (3’) transparent, dispuse paralel unul fata de celalalt si care formează împreuna cu cadrul (2), o carcasa ermetica (1.1) cu o grosime (w). Grosimea (w) este masurata intr-un plan transversal, perpendicular pe laturile înguste ale cadrului (2) si pe cele doua panouri (3, 3’), ca suma a grosimii celor doua panouri (3, 3’) si a distantei măsurate perpendicular intre acestea doua (3, 3’) in interiorul carcasei ermetice (1.1). De preferința, grosimea (w) carcasei ermetice (1.1) este intre 24 mm si 32 mm, mai preferabil 24 mm. Aceasta grosime (w) de 24 mm permite instalarea colectorului solar plan (1) in ramele standardizate de fereastra/usa, de exemplu termopan cu grosimea de 24 mm.The planar solar collector (1) further comprises a first transparent panel (3) and a second transparent panel (3 '), arranged parallel to each other and forming together with the frame (2), an airtight housing (1.1). ) with a thickness (w). The thickness (w) is measured in a transverse plane, perpendicular to the narrow sides of the frame (2) and the two panels (3, 3 '), as the sum of the thickness of the two panels (3, 3') and the measured distance perpendicular between these two (3, 3 ') inside the hermetic housing (1.1). Preferably, the thickness (w) of the hermetic housing (1.1) is between 24 mm and 32 mm, more preferably 24 mm. This thickness (w) of 24 mm allows the installation of the flat solar collector (1) in the standardized window / door frames, for example double glazing with a thickness of 24 mm.

[0021] Primul panou (3) transparent prezintă o suprafața exterioara si o suprafața interioara. Aceasta din urma se afla in interiorul carcasei ermetice (1.1). Suprafața exterioara a primului panou (3) transparent permite ca aproximativ 75-80% din radiația solara incidența (directa si difuza) sa fie parțial reflectata si parțial absorbita in incinta carcasei ermetice (1.1), după ce traversează, cu pierderi de aproximativ 20% din radiația solara incidența, primul panou (3) transparent. De preferința, cele doua panouri (3, 3’) transparente sunt fabricate din sticla, deoarece prezintă un grad ridicat de absortie a radiației solare si izolare termica si fonica ridicata.The first transparent panel (3) has an outer surface and an inner surface. The latter is inside the airtight housing (1.1). The outer surface of the first transparent panel (3) allows approximately 75-80% of the incidence solar radiation (direct and diffuse) to be partially reflected and partially absorbed inside the hermetic housing (1.1), after crossing, with losses of approximately 20% from the incidence of solar radiation, the first panel (3) transparent. Preferably, the two transparent panels (3, 3 ') are made of glass, because they have a high degree of absorption of solar radiation and high thermal and sound insulation.

[0022] Al doilea panou (3’) transparent prezintă deasemenea o suprafața exterioara si o suprafața interioara. Aceasta din urma este orientata spre suprafața interioara a primului panou (3) transparent si are prevăzut un strat cu emisivitate scăzută (denumit in mod uzual, strat „low-e” sau „reflexiv”). Acest strat cu emisivitate scăzută (low-e) include un strat metalic subțire sau de oxizi metalici (de regula oxizi de argint) depus, printr-un proces industrial special. Stratul cu emisivitate scăzută (lowe) are rolul de a reflecta o mare parte din radiația solara, astfel incat menține căldură in interiorul carcasei (1.1). Astfel, se limitează practic pierderile de căldură.The second transparent panel (3 ') also has an outer surface and an inner surface. The latter is oriented towards the inner surface of the first transparent panel (3) and has a low emissivity layer (usually called "low-e" or "reflective" layer). This low-e layer includes a thin layer of metal or metal oxides (usually silver oxides) deposited through a special industrial process. The low emissivity layer (lowe) has the role of reflecting a large part of the solar radiation, so that it maintains heat inside the housing (1.1). Thus, heat losses are practically limited.

[0023] In interiorul carcasei ermetice (1.1) se afla dispus, paralel cu panourile menționate (3, 3’) si distantat fata de acestea, prin intermediul a cel puțin doua distantiere (4, 4’), un element absorbant (5) avand una dintre cele doua suprafețe ale 5 sale orientata către primul panou (3) transparent si pe care este fixat un tub flexibil (6), continuu, de culoare neagra, sub forma unei serpentine, prin care poate circula un agent termic. Tubul (6) este prevăzut cu conexiuni de alimentare/evacuare a agentului termic la cate un capat al tubului (6), conectat la cadru (2). De preferința, tubul (6) flexibil, de culoare neagra este realizat dintr-un polimer. Tubul (6) flexibil are de preferința un diametru interior cuprins intre 8 mm si 12 mm cu o grosime de 1 mm constanta pe toata lungimea tubului (6). Grosimea tubului (6) se masoara ca diferența dintre diametru exterior al tubului (6) si diametrul interior al acestuia. S-a observat experimental ca avand aceste dimensiuni, tubul (6) asigura încălzirea uniforma in toata masa agentului termic. Agentul termic este de preferința apa, etilenglicol sau propilenglicol. Deasemenea, diametrul interior relativ mic al tubului (6) flexibil, de culoare neagra si circulația fortata a agentului termic prin acest tub (6), împiedica formarea unui strat superficial la contactul dintre fluid si peretele cald al tubului (6), strat care ar reduce transferul termic.Inside the hermetic housing (1.1) is arranged, parallel to said panels (3, 3 ') and spaced from them, by means of at least two spacers (4, 4'), an absorbent element (5) having one of its two surfaces 5 oriented towards the first transparent panel (3) and on which is fixed a flexible tube (6), continuous, black, in the form of a coil, through which a thermal agent can circulate. The tube (6) is provided with heat supply / discharge connections at one end of the tube (6), connected to the frame (2). Preferably, the flexible, black tube (6) is made of a polymer. The flexible tube (6) preferably has an inner diameter between 8 mm and 12 mm with a constant thickness of 1 mm along the entire length of the tube (6). The thickness of the tube (6) is measured as the difference between the outer diameter of the tube (6) and its inner diameter. It has been experimentally observed that having these dimensions, the tube (6) ensures uniform heating in the whole mass of the thermal agent. The thermal agent is preferably water, ethylene glycol or propylene glycol. Also, the relatively small inner diameter of the flexible, black tube (6) and the forced circulation of the thermal agent through this tube (6), prevent the formation of a superficial layer at the contact between the fluid and the warm wall of the tube (6). reduces heat transfer.

[0024] Elementul absorbant (5) este un element metalic plan, de culoare neagra, prevăzut cu o multitudine de orificii (7) ce permit trecerea parțiala a razelor solare incidente dinspre primul panou (3) transparent către al doilea panou (3’) transparent. De preferința, elementul absorbant (5) este confecționat din tabla metalica perforata, de exemplu din otel, aluminiu sau cupru si avand o grosime cuprinsa, de preferința intre 0,5 si 0,8 mm. Avantajele utilizării tablei perforate, in contextul prezentei invenții sunt: încălzirea rapida prin absorbția radiației solare incidente si transferul căldurii prin convectie către tubul (6) flexibil, ventilare optima, greutate redusa, durabilitate. Tabla perforata permite trecerea parțiala a razelor solare, incidente pe o suprafața libera a acestuia, de preferința de cel puțin 50% din suprafața sa totala. Prin suprafața libera se înțelege suprafața calculata ca suma a suprafețelor orificiilor (7).The absorbent element (5) is a flat, black metal element provided with a plurality of holes (7) which allow the partial passage of incident sunlight from the first transparent panel (3) to the second panel (3 '). transparent. Preferably, the absorbent element (5) is made of perforated sheet metal, for example steel, aluminum or copper and having a thickness of preferably between 0.5 and 0.8 mm. The advantages of using perforated sheet in the context of the present invention are: rapid heating by absorption of incident solar radiation and heat transfer by convection to the flexible tube (6), optimal ventilation, low weight, durability. The perforated sheet allows the partial passage of the sun's rays, incident on a free surface of it, preferably at least 50% of its total surface. Free surface means the area calculated as the sum of the areas of the holes (7).

[0025] O parte din razele solare incidente ce trec prin multitudinea de orificii (7) a elementului absorbant (5), dinspre primul panou (3) transparent către al doilea panou (3’) transparent, sunt captate de suprafața interioara cu strat cu emisivitate scăzută (low-e) a celui de-al doilea panou (3’) transparent si prin procesul de reflexie, acestea sunt absorbite de către suprafața elementului absorbant (5) pe care nu este fixat tubul flexibil (6), generând o creștere a temperaturii elementului absorbant (5). Totodată, datorita multitudinii de orificii (7), este posibila iluminarea parțiala a spațiului unei incinte, dintr-o clădire, unde este montat colectorul solar plan (1) conform prezentei invenții.Part of the incident sunlight passing through the plurality of holes (7) of the absorbent element (5), from the first transparent panel (3) to the second transparent panel (3 '), are captured by the inner surface with a layer of low emissivity (low-e) of the second transparent panel (3 ') and by the reflection process, they are absorbed by the surface of the absorbent element (5) on which the flexible tube (6) is not fixed, generating an increase of the temperature of the absorbent element (5). At the same time, due to the multitude of holes (7), it is possible to partially illuminate the space of an enclosure, in a building, where the planar solar collector (1) according to the present invention is mounted.

[0026] Intr-un alt exemplu preferat de realizare al prezentei invenții, colectorul solar plan (1) mai cuprinde un strat izolator termic (8), preferabil de aer ce separa primul panou (3) transparent de elementul absorbant (5) si un al doilea strat izolator termic (8’), de aer ce separa suprafața elementului absorbant (5) pe care nu este fixat tubul flexibil (6), de stratul cu emisivitate scăzută (low-e) al celui de-al doilea panou transparent (3’)· Astfel, creste performanta termica si gradul de izolare termica si fonica a colectorului solar plan (1).In another preferred embodiment of the present invention, the planar solar collector (1) further comprises a thermal insulating layer (8), preferably of air separating the first transparent panel (3) from the absorbent element (5) and a the second thermal insulating layer (8 '), of air separating the surface of the absorbent element (5) on which the flexible tube (6) is not fixed, from the low emissivity layer (low-e) of the second transparent panel ( 3 ') · Thus, the thermal performance and the degree of thermal and sound insulation of the planar solar collector (1) increase.

[0027] Pe distantierul (4’) aflat intre elementul absorbant (5) si al doilea panou (3’) transparent, se pot monta elemente ce fac legătură, la interiorul carcasei ermetice 6 (1.1) cu cele doua capete ale tubului (6) flexibil si la exteriorul carcasei (1.1) cu conexiunile de alimentare/evacuare a agentului termic pentru racordarea, de exemplu la o instalație de încălzire sau de producere a apei calde menajere.On the spacer (4 ') between the absorbent element (5) and the second transparent panel (3'), connecting elements can be mounted inside the hermetic housing 6 (1.1) with the two ends of the tube (6). ) flexible and on the outside of the housing (1.1) with the supply / outlet connections of the heating medium for connection, for example to a heating or domestic hot water production installation.

[0028] Funcționarea colectorului solar plan (1) conform invenției se realizează in 3 etape in care:The operation of the planar solar collector (1) according to the invention is carried out in 3 steps in which:

I. Aproximativ 30% din radiația solara incidența ce traversează primul panou (3) transparent este absorbita direct de suprafața exterioara a tubului (6) flexibil, de culoare neagra. Aici are loc un transfer de căldură prin conductie de la suprafața exterioara la cea interioara a tubului (6) si apoi un transfer de căldură prin convectie de la suprafața interioara a tubului (6) la agentul termic aflat in circulație in interiorul tubului (6);I. Approximately 30% of the solar radiation the incidence passing through the first transparent panel (3) is absorbed directly by the outer surface of the flexible, black tube (6). Here a heat transfer by conduction takes place from the outer to the inner surface of the tube (6) and then a heat transfer by convection from the inner surface of the tube (6) to the thermal agent circulating inside the tube (6) ;

II. Aproximativ 30%-35% din radiația solara incidența este absorbita de suprafața elementului absorbant (5) orientata către primul panou (3) transparent si pe care este fixat tubul (6) flexibil. Aceasta suprafața a elementului absorbant (5) se încălzește si transfera energia calorica prin conductie către suprafața exterioara a tubului (6) flexibil. In continuare, procesul de transfer de căldură se realizează conform etapei I;II. Approximately 30% -35% of the incidence solar radiation is absorbed by the surface of the absorbent element (5) oriented towards the first transparent panel (3) and on which the flexible tube (6) is fixed. This surface of the absorbent element (5) heats up and transfers the heat energy through the pipe to the outer surface of the flexible tube (6). Next, the heat transfer process is performed according to step I;

III. Aproximativ 30%-35% din radiația solara incidența traversează multitudinea de orificii (7) a elementului absorbant (5) si sunt captate de suprafața interioara cu strat cu emisivitate scăzută (low-e) a celui de-al doilea panou (3’) transparent. Prin procesul de reflexie, acestea sunt absorbite apoi de către suprafața elementului absorbant (5), pe care nu este fixat tubul flexibil (6), generând o creștere a temperaturii elementului absorbant (5). Procesul de transfer de căldură se realizează apoi conform etapei II.III. Approximately 30% -35% of the incidence solar radiation passes through the multitude of holes (7) of the absorbent element (5) and are captured by the inner surface with low emissivity layer (low-e) of the second panel (3 ') transparent. Through the reflection process, they are then absorbed by the surface of the absorbent element (5), on which the flexible tube (6) is not fixed, generating an increase in the temperature of the absorbent element (5). The heat transfer process is then performed according to step II.

[0029] Aceasta funcționare conduce la un numărul redus de procese de schimb de căldură, recuperarea radiațiilor solare incidente prin folosirea elementului absorbant (5) in combinație cu o suprafața interioara cu strat cu emisivitate scăzută (low-e) a celui de-al doilea panou (3’) transparent, orientata către elementul absorbant (5), conform invenției si creșterea cantitatii de căldură transferata agentului termic. Pierderile termice sunt limitate substanțial si astfel se realizează creșterea randamentului de conversie a energiei solare in energie termica.This operation leads to a reduced number of heat exchange processes, the recovery of incident solar radiation by using the absorbent element (5) in combination with an inner surface with low emissivity layer (low-e) of the second transparent panel (3 '), oriented towards the absorbent element (5), according to the invention and increasing the amount of heat transferred to the thermal agent. Thermal losses are substantially limited and thus increase the efficiency of conversion of solar energy into thermal energy.

[0030] Sfera prezentei invenții nu se limitează la exemplele de realizare specifice descrise aici. In plus, din descriere si figurile însoțitoare, pentru specialistul in domeniu rezulta diferite alte modificări ale prezentei invenții, suplimentar fata de exemplele prezentate aici, care se incadreaza, de asemenea, in domeniul de protecție al revendicărilor. Suplimentar, in descriere sunt citate diferite documente din stadiul tehnicii cunoscut, al căror conținut este prezentat in integralitatea acestora prin referința.The scope of the present invention is not limited to the specific embodiments described herein. In addition, various other modifications of the present invention result from the description and accompanying figures to the person skilled in the art, in addition to the examples set forth herein, which also fall within the scope of the claims. Additionally, the description cites various documents of the known state of the art, the content of which is presented in their entirety by reference.

Claims

demand

A planar solar collector (1) comprising:

a substantially rectangular frame (2) in cross section;

a first transparent panel (3) and a second transparent panel (3 '), arranged parallel to each other and forming together with said frame (2), an airtight housing (1.1) with a thickness (w), inside which is arranged, parallel to the said panels (3, 3 ') and spaced from them, by means of at least two spacers (4, 4'):

o an absorbent element (5) having a surface oriented towards the first transparent panel (3) and on which is fixed a flexible tube (6), continuous, black, in the form of a coil, through which a thermal agent can circulate;

o said tube (6) is provided with supply / discharge connections of the thermal agent at one end of the tube (6), connected to said frame (2), characterized in that the absorbent element (5) is a flat metal element, black, provided with a plurality of holes (7) which allow the partial passage of incident sunlight from the first transparent panel (3) mentioned to the second transparent panel (3 ') and thereby the second panel (3' ) said transparent layer has a low emissivity (low-e) on its inner surface, facing the said absorbent element (5).

Flat solar collector (1) according to claim 1, characterized in that the absorbent element (5) allows the partial passage of incident sunlight on a free surface thereof of at least 50% of its total surface.

Flat solar collector (1) according to claim 1 or 2, characterized in that the thickness (w) of the hermetic housing (1.1) is preferably between 24 mm and 32 mm, more preferably 24 mm.

Flat solar collector (1) according to any one of the preceding claims, characterized in that the absorbent element (5) is made of perforated metal sheet, preferably of steel, aluminum or copper and having a thickness of preferably between 0.5 and 0.8 mm.

Flat solar collector (1) according to any one of the preceding claims, characterized in that the flexible tube (6) preferably has an inner diameter of between 8 mm and 12 mm with a constant thickness of 1 mm along the entire length of the tube (6) .

Flat solar collector (1) according to any one of the preceding claims, characterized in that the flexible tube (6) is made of a polymer.

Flat solar collector (1) according to any one of the preceding claims, characterized in that said transparent panels (3, 3 ') are preferably made of glass.

Flat solar collector (1) according to any one of the preceding claims, characterized in that said frame (2) is preferably made of at least one 'hot edge' spacer.

Flat solar collector (1) according to any one of the preceding claims, further comprising:

- a thermal insulating layer (8), of air separating the first transparent panel (3) from the absorbent element (5) and

- a second thermal insulating layer (8 '), of air separating the surface of the absorbent element (5) on which the flexible tube (6) is not fixed, from the low emissivity layer (low-e) of the second panel transparent (3 ') ·

Flat solar collector (1) according to any one of the preceding claims, characterized in that the thermal agent is preferably water, ethylene glycol or propylene glycol.

System consisting of a planar solar collector (1) according to any one of the preceding claims and a window or door frame.