RU2523616C2 - Energy-efficient solar collector - Google Patents

Abstract

FIELD: power industry.

SUBSTANCE: energy-efficient solar collector (ESC) refers to renewable energy sources, in particular to solar energy, and is designed to absorb solar radiation, convert it into thermal energy in order to supply hot water to residential and non-residential buildings of different purpose. The purpose of invention is to improve the efficiency of solar energy use, reduce the thickness, reduce the weight and prime cost of ESC.

EFFECT: use of ESC indirectly restricts the emission of greenhouse gases due to replacement of conventional energy sources of thermal power plants used for hot water supply.

10 cl, 3 dwg, 1 tbl

Description

Energy-efficient solar collector (ESC) refers to renewable energy sources, in particular the energy of the Sun, and is designed to absorb solar radiation, converting it into thermal energy for the purpose of hot water supply of residential and non-residential premises for various purposes.

Known solar collector [1], designed to work in the northern territories and containing a sealed enclosure with a transparent top panel. A heat-receiving device in the form of a tubular collector for passing the coolant is installed inside the sealed housing. In the upper part of the housing, along the entire perimeter, photocells are placed in the form of a strip in contact with a transparent conductive element on which a transparent panel is mounted. In addition, the collector contains an electrical circuit including a control unit with a switch, a battery and a snow cover pressure sensor. The presence in the collector of solar cells that convert solar energy into thermal and electrical energy, as well as an electrical circuit connected to the solar cells and a transparent conductive element and through the control unit, charge the battery in sunny weather to accumulate electrical energy and discharge the battery to a transparent conductive element when snow cover through the pressure sensor of the snow cover, and in cloudy and frosty weather - through the control unit switch to heat the her transparent panel ensures stable operation of the reservoir in a northern territories without additional energy sources. The disadvantages of this invention are the difficulties of using a snow pressure sensor, since even a small layer of snow on the solar collector already interferes with the operation of solar cells, and a pressure sensor configured to weigh snow of small thickness will be triggered by high-speed wind pressure, which determines difficulties in reliable operation of the invention .

Known invention [2], which contains a closed shell of a transparent single-layer or multilayer material of width L, consisting of a central cylindrical surface of radius R, mating with it on its extreme edges of two side cylindrical surfaces of radius r and a plane tangent to two side cylindrical surfaces, two end caps mounted on the ends of the shell, and a flat heat-receiving panel placed in the shell with a width of H and a thickness of t with a selective absorbing coating and with channels for the flow of liquid coolant, and the geometric dimensions of the shell and the heat-receiving panel are connected by the following ratios: 5H≥R≥3H; l, 5t≥r≤ (√2 / 2) t; 1.1H≥L≥1.05N. The invention allows to increase the efficiency of the solar collector by 10-15%, to increase its resistance to weathering. The disadvantages of this invention are: a large height of the solar collector, based on the above formulas; according to the drawing, it is not obvious (one channel is shown) an increase of 10% -12% in operating efficiency, since the distance between the channels for the coolant is not indicated, while it is known that heat removal from the absorbing panel is provided by the area of its contact with the channels.

A known solar energy collector for heating a liquid [3], having in its composition an absorber of solar energy, a lining, between the lining and an absorber - a cavity for liquid, a chute for draining heated liquid, inlet and outlet pipes. The disadvantage of this collector is that it cannot be supplied with liquid under pressure, for example, connected to a water supply, as this creates significant stresses in the collector designs that the collector cannot withstand without destruction.

The closest in technical essence to the claimed ESC is the invention [4], containing at least two similar interconnected fragments made with a profiled surface having corrugations, and interconnected with the possibility of pairing and tight tight connection to each other on the outside the perimeter and inside it, on the outside of one of which a selective absorbing coating is applied, an input and output collector with fittings. The profiled surface is formed as a result of plastic deformation under the action of internal pressure of initially flat sheet fragments, previously hermetically connected to each other, wide triangular, round or drop-shaped ends are formed at the ends of the rigid joints, intermittent joints of the rigid joint are located between them and the collectors, and the distance between the tips and the intermittent seam perpendicular to them are at least five hundredths and not more than one distance between Sedna corrugations. The technical result consists in reducing the cost, energy and material consumption, increasing the reliability and manufacturability of the manufacture of heat-receiving panels. The disadvantages of this invention are: the need for special technological equipment for the manufacture of a heat-receiving panel, a very high probability of loss of tightness during plastic deformation under the influence of internal pressure to form corrugations from sheets previously tightly interconnected, and the metal of the heat-receiving panel will practically not change compared to analogues [5].

An essential distinguishing feature of the proposed ESC is the presence of a plastic two-chamber housing with aluminum inserts for stiffening the plastic two-chamber duct, as well as wavy optically active transparent insulation made of impact-resistant glass, and the waves represent longitudinal biconvex lenses with straight sections between the waves. In general, the design of the ESC is maximally adapted to the production of plastic windows.

A significant advantage is the presence in the design of ESCs: an absorbing panel made of tandem tubes representing an assembly of aluminum and copper tubes, the thick-walled aluminum pipe mounted on a thin-walled copper pipe; aluminum mesh; aluminum heat accumulating chips; rectangular collectors for cold and hot coolant (water, ethylene glycol, etc.); aluminum bushings for connecting tandem tubes with rectangular collectors; heat-resistant plastic inserts with a mirrored inner surface mounted on the inner side walls of the plastic two-chamber housing between the transparent insulation and the rear wall; branch pipes for cold and hot heat carrier; back wall made of heat-resistant plastic and having a mirror inner surface.

The purpose of the invention is to increase the efficiency of use of solar energy, reducing thickness, reducing the weight and cost of ESCs, as well as improving the manufacturability of the design of the collector. The use of ESCs indirectly limits the emission of greenhouse gases by replacing traditional energy sources of thermal power plants used for hot water supply.

The device and components of the ESC are shown in the drawings: in Fig.1 is a General view in cross section; figure 2 is a General view in longitudinal section; figure 3 is a General view of a removable cover.

The ESC consists of the following components: a plastic two-chamber case 1 with aluminum inserts 2 for stiffening the plastic two-chamber box; wavy optically active transparent insulation 3 made of impact resistant glass, and the waves are longitudinal biconvex lenses 4 with straight sections between the waves 5; rubber U-shaped seal 6 for sealing the connection of optically active transparent insulation 3 with the housing 1; an absorbing (heat-absorbing) panel 7, consisting of tandem tubes 8, which represent an assembly of thick-walled aluminum 9 and thin-walled copper 10 tubes, the thick-walled aluminum pipe 9 being mounted on a thin-walled copper pipe 10 using heat-resistant adhesive sealant; aluminum mesh 11; tandem tubes 8, having conical bores on both sides at an angle of 45 ° (not marked), providing free flow of cold heat transfer fluid (coolant) from the rectangular manifold 13 into the tandem tubes 8 and then the heated coolant into the rectangular collector 14; heat-accumulating aluminum chips 12 in the space between the grid and the rear wall of the housing; rectangular collectors 13, 14 for cold and hot coolant, respectively; flanges 15 of rectangular collectors 13, 14 for a coolant with holes for fixing bolts 16; removable covers 17, 18 of rectangular collectors (rectangular collectors) 13, 14 with holes 25 matching the holes of the beads 15 for the fixing bolts 16; aluminum bushings 19 for connecting the tandem tubes 8 with rectangular collectors 13, 14; heat-resistant plastic inserts with a mirrored inner surface 20 located on small opposite sides of the inner surface of the housing 1; nozzles for cold and hot heat carrier 21, 22, respectively, which are attached to the side walls of the housing 1 and rectangular collectors 13, 14 using heat-resistant glue; the back wall 23 made of heat-resistant plastic and having a mirror inner surface 24, for example, made of foil, which is glued to the outer surface of the back wall, previously coated on both sides with at least two layers of heat-insulating paint.

ESC works as follows. Solar radiation penetrates through biconvex lenses 4 and rectilinear sections 5 of wavy optically active transparent insulation 3, heats the absorbing panel 7, consisting of tandem tubes 8, the outer surface of which has a highly selective coating. Moreover, the longitudinal biconvex lenses 4 concentrate the sun's rays on the tandem tubes 8 of the absorbing panel 7, the aluminum mesh 11 and the aluminum heat-accumulating shavings 12. In addition, the sun's rays, reflected from the mirror surface of the plastic inserts 25, participate in the thermal heating of the tandem tubes 8. Thermal heating of the tandem tubes tubes 8 also comes from the reflected heat rays by the mirror surface 24 of the rear wall 23. Heat transfer of the heat-transfer fluid by the tandem tubes 8 is as follows. Cold heat transfer fluid is supplied through a pipe 21 to a rectangular collector 13 for cold coolant, from where it enters the tandem tubes 8. Aluminum thick-walled tubes 9 heated by solar radiation accumulate and transfer heat to thin-walled copper tubes 10, which, having high thermal conductivity (table), into their in turn, the coolant is quickly heated, which enters the rectangular collector 14 for hot coolant and then through the pipe 22 to consumers. The heat transfer efficiency of the tandem tubes 8 is ensured by the different thermophysical properties of the aluminum thick-walled tubes 9 and copper thin-walled tubes 10 (table).

Table Comparative characteristics of the thermal properties of copper and aluminum Metal Temperature,
° C Specific heat, J / kg · ° C Temperature ° C Thermal conductivity, kW / m · ° C Copper 97.5-sv. 1100 0.40-0.55 twenty 0.386 Aluminum
niy 0-100 to 660 0.87-1.27 twenty 0.210

The table shows that the heat capacity of aluminum is more than 2 times greater than that of copper, and the thermal conductivity of copper is 1.84 times greater than that of aluminum. Thus, the thick-walled aluminum pipe 9, having a large volume and heat capacity, accumulates solar radiation directly from the wavy optically active transparent insulation 3, aluminum heat-accumulating shavings 12, partly from the aluminum mesh 11, and also accumulates reflected heat and sunlight from the mirror internal surface of heat-resistant plastic inserts 19; while a copper thin-walled pipe 9, having greater thermal conductivity, intensively removes heat from an aluminum thick-walled pipe 8. In the case of temporary shading of the sun by clouds or after sunset, the aluminum accumulated thick-walled pipe 8, aluminum heat-accumulating shavings 12 and aluminum mesh 11 heat is completely removed by copper thin-walled pipe 9 and is transferred to the coolant.

The efficiency of ESCs is enhanced by the use of tandem tubes 7, wavy optically active transparent insulation 3, aluminum mesh 10, aluminum heat-accumulating chips 11, heat-resistant plastic inserts 19 with a mirror inner surface, a back wall 22 made of heat-resistant plastic and having a mirror inner surface 23, the outer surface of which is covered by at least two layers of thermally insulating paint.

ESC can be installed at an angle to the horizon from 0 ° to 90 °, which ensures its operation on terrain of any latitude or on the vertical walls of buildings. The use of aluminum sleeves 18 for connecting tandem tubes 8 with rectangular collectors 13, 14 using heat-resistant adhesive sealant simplifies the assembly of tandem tubes 8. The presence of rectangular collectors 13, 14 for cold and hot coolant, respectively, and beads 15 of collectors of rectangular section 13, 14 with holes for fixing bolts 15, removable covers 16, 17 of rectangular collectors 13, 14 with holes matching holes of beads 15 for fixing bolts 16, makes ESK maintainable. Rubber U-shaped seal 6 is used to seal the connection of optically active transparent insulation 3 and the back cover 23 with the housing 1. The advantages of ESCs are also: maximum adaptation to window frame assembly technology, the absence of aluminum and copper welding due to the use of heat-resistant adhesive sealant, small the thickness of the structure, which is achieved through the use of heat-insulating paint.

Given the above, the cost of ESCs is 30-35% less than that of existing analogues.

List of references

1. Solar collector, patent RU No. 2428637 from 09/10/2011.

2. Solar collector, patent RU No. 2393390 C1 of 06/27/2010.

3. Solar collector for heating fluid. Sonnenkollektor zur Erwarmimq eines Fluides. Application Germany No. 4104638, M. cl. F24J 2/48, cost Kurlfried. No. 4104638.2, declared 02/15/1991, publ. 08/20/1992.

4. The heat-receiving panel, patent RU No. 2450217 C2 from 11/27/2011.

5. Kharchenko N.V. Individual solar installations. M .: Energoatomizdat, 1991 .-- 208 p.

Claims (10)

1. Energy-efficient solar collector (ESC), comprising a housing, a transparent insulator, a heat-receiving panel, an input and output nozzles, characterized in that it has a plastic two-chamber housing with aluminum inserts, a wavy optically active transparent insulation, the waves of which are longitudinal biconvex lenses with rectilinear sections between waves, heat-receiving panel made of tandem tubes, aluminum mesh, aluminum chips in the space between the mesh and the rear wall of the housing, rectangular ollektory for solar liquid. 2. ESC according to claim 1, characterized in that the tandem tubes represent an assembly of aluminum thick-walled and copper thin-walled tubes, and the aluminum thick-walled pipe is mounted on a thin-walled copper pipe using heat-resistant adhesive sealant. 3. ESC according to claim 1, characterized in that the rear wall is made of heat-resistant plastic and has a mirror inner surface made of foil, which is glued to the outer surface of the rear wall. 4. ESC according to claim 3, characterized in that the back wall is coated on both sides with thermally insulating paint. 5. ESC according to claim 1, characterized in that the heat-resistant plastic inserts with a mirrored inner surface are located on small opposite sides of the inner surface of the housing. 6. ESC according to claim 1, characterized in that the nozzles for cold and hot heat-transfer fluid are attached to the side walls of the housing and rectangular collectors using heat-resistant adhesive. 7. ESC according to claim 1, characterized in that the tandem tubes have conical bores on both sides at an angle of 45 °, providing free flow of heat-transfer fluid. 8. ESC according to claim 1, characterized in that the rectangular collectors have flanges with holes for the fixing bolts. 9. ESC according to claim 1, characterized in that the removable covers of the rectangular collectors have holes matching the holes of the flanges for the fixing bolts. 10. ESC according to claim 1, characterized in that the ESC assembly technology is maximally adapted to the window frame assembly technology; there is no welding of aluminum and copper due to the use of heat-resistant adhesive sealant.

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