CN114156359B - A gap film used for photovoltaic cell assembly and photovoltaic cell assembly - Google Patents

Abstract

The present invention discloses a gap film and a photovoltaic cell assembly applied to a photovoltaic cell assembly. The gap film of the present invention comprises a substrate, a backing layer and a microstructured reflective layer which are stacked in sequence; the upper surface of the microstructured reflective layer has a plurality of strip-shaped triangular prism-like structures, and a transition ridge structure located between two adjacent triangular prism-like structures; the two side surfaces of the triangular prism-like structures are arc-shaped side surfaces which are concave inward. By arranging a triangular prism-like structure with arc-shaped side surfaces on the microstructured reflective layer, incident light is concentrated and reflected, so that the light can be better concentrated and efficiently reused; the transition ridge structure maintains a sufficient distance between two adjacent triangular prism-like structures, while ensuring that light energy is not wasted. Thereby, the photoelectric efficiency of the solar photovoltaic assembly is effectively improved. The photovoltaic cell assembly of the present invention adopts the gap film, which can effectively reduce the waste of light energy and has high photovoltaic power generation efficiency.

Description

A gap film used for photovoltaic cell assembly and photovoltaic cell assembly

Technical Field

The invention relates to the technical field of photovoltaic power generation, and in particular to a gap film applied to a photovoltaic cell assembly and a photovoltaic cell assembly.

Background Art

Solar cells, also known as photovoltaic cells, are photovoltaic modules that use light energy to generate electricity. In a solar photovoltaic module, there are multiple photovoltaic module cells, which use sunlight to generate photovoltaic power. Among them, there are inevitably gaps between multiple photovoltaic module cells. Sunlight shining on the gaps cannot generate photovoltaic power, so the effective area of the solar photovoltaic module is reduced and the photoelectric efficiency is reduced. Moreover, when sunlight directly hits the gap surface, the substrate surface at the gap will directly reflect the sunlight away. This part of the sunlight cannot be used by the photovoltaic module cells, which directly causes a waste of light energy and further reduces the photoelectric efficiency.

In order to reduce the waste of light energy caused by direct reflection of light and increase the effective area of solar photovoltaic modules, it is necessary to utilize the light energy incident on the gaps between photovoltaic module cells to improve the efficiency of light energy utilization. At present, the main existing solution is to directly attach reflective film to the gaps between photovoltaic module cells. The reflective film has a reflective surface that is relatively inclined to the vertical surface. When sunlight is incident on the reflective surface of the reflective film, it can change the propagation direction and be obliquely incident on the photovoltaic glass, and then be indirectly reflected by the photovoltaic glass to the photovoltaic module cells for utilization.

However, the reflective surfaces of existing reflective films are all planes, such as a photovoltaic module reflective film disclosed in patent CN2016112018221, whose reflective structure is a triangular prism, with the straight side of the triangular prism as the reflective surface, and the parallel light entering the reflective film will still be reflected as parallel light. The flat reflective surface easily causes part of the light to be directly reflected out, and the reflected parallel light has low intensity and energy compared to the direct light directly irradiated on the photovoltaic power generation area, and the utilization efficiency of photovoltaic power generation is low. In addition, the reflective plane of the reflective film is a closely arranged array of parallel planes, and it is easy for them to block the light path from each other, which will further weaken the light energy.

Summary of the invention

The purpose of the present invention is to solve the problem that the existence of gaps between photovoltaic module cells in the prior art leads to low photoelectric efficiency of solar photovoltaic modules, and the reflective surface of the existing reflective film is a plane, and the reflected light is parallel light. The light incident on the gaps between photovoltaic module cells cannot be better concentrated and efficiently reused, and the photoelectric efficiency of solar photovoltaic modules cannot be effectively improved. In order to solve the above defects or deficiencies, the present invention provides a gap film applied to photovoltaic cell modules.

The present invention also aims to provide a photovoltaic cell assembly, which uses the gap film.

The purpose of the present invention is achieved through the following technical solutions.

A gap film applied to a photovoltaic cell assembly comprises a substrate, a backing layer and a microstructured reflective layer; the backing layer and the microstructured reflective layer are sequentially stacked on the substrate;

The upper surface of the microstructure reflective layer is composed of a reflective convex microstructure; the reflective convex microstructure includes a plurality of strip-shaped triangular prism-like structures and a transition ridge structure located between two adjacent triangular prism-like structures; the two side surfaces of the triangular prism-like structures are inwardly concave arc-shaped side surfaces.

In a preferred embodiment, the triangular prism-like structures are arranged in an array, and the transition ridge structure is integrally disposed between two adjacent triangular prism-like structures; and the length direction of the transition ridge structure is consistent with the length direction of the triangular prism-like structures, and both side surfaces of the triangular prism-like structures face the transition ridge structure.

Both side surfaces of the triangular prism-like structure are arranged as inwardly concave arc-shaped side surfaces. In the process of reflecting the incident light, the arc-shaped side surfaces can collect and reflect the reflected light to the photovoltaic power generation area, so that the light can be better concentrated and efficiently reused, effectively improving the photoelectric efficiency of the solar photovoltaic module.

In a preferred embodiment, the height of the triangular prism-like structure is 13 to 16 μm. Within this range, the height of the triangular prism-like structure is not too large to affect the structure of the overall gap membrane, and is not easily deformed by pressure, effectively maintaining the stability of the structure, and being able to reasonably provide the required position of its curved side.

In a preferred embodiment, the curvature of the curved side surface of the triangular prism-like structure is 0.6-1.0 rad.

When the height and curvature of the quasi-triangular prism structure are determined, the radius of the arc can be uniquely determined, and the corresponding arc length can also be determined. Within this curvature range, the radius of the arc is not too large to cause excessive inward depression, thereby affecting the light-gathering efficiency and reflection efficiency of the arc side, nor is it too small to make the arc surface tend to be flat, failing to achieve the effect of light collection, so that the light can be better concentrated and reflected for utilization, thereby improving the efficiency of light energy utilization.

The setting of the transition ridge structure enables a sufficient distance to be maintained between two adjacent triangular prism-like structures, thereby avoiding the phenomenon that the two adjacent triangular prism-like structures block the light path from each other.

In a preferred embodiment, the transition ridge structure has a height of 2 to 5 μm, and a surface that is a raised arc-shaped surface with a radian of 1.8 to 2.2 rad.

The height of the transition ridge structure is selected within this range, and combined with the corresponding surface curvature range, the width of the transition ridge structure can be determined to ensure that there is sufficient spacing between two adjacent triangular prism-like structures.

In addition, since the surface of the transition ridge structure is an arc-shaped surface, most of the light irradiated on the surface will be reflected on the arc-shaped side of the triangular prism-like structure, and then concentrated and reflected to the photovoltaic power generation area, and a small part of the light will be directly reflected to the photovoltaic power generation area through its surface. This not only ensures the spacing between the triangular prism-like structures, guarantees the light-collecting and reflection efficiency of the triangular prism-like structures, and effectively improves the power generation efficiency of solar photovoltaic modules, but also ensures that the light energy irradiated between two adjacent triangular prism-like structures will not be wasted, but can be effectively concentrated and reused.

In a preferred embodiment, the microstructure reflective layer includes a microstructure layer and a reflective layer; the microstructure layer is arranged on the adhesive layer, the upper surface of the microstructure layer has the reflective protruding microstructure, and the reflective layer covers the upper surface of the microstructure layer.

In a more preferred embodiment, the substrate is a PET (polyethylene terephthalate) film; the substrate is made of PET film, so that the overall gap membrane has better basic support stability, and the thickness of the PET film is thin, which will not have a significant impact on the thickness of the overall gap membrane, which is conducive to the thinner thickness design of the overall gap membrane.

And/or, the back adhesive layer is an EVA hot melt adhesive layer; EVA hot melt adhesive has good thermosetting stability, fast curing, good hardness, is convenient for the preparation and molding of the gap membrane, and has good supporting stability for the overall gap membrane.

And/or, the microstructure layer is a UV curing glue layer; the UV curing glue can be cured under ultraviolet light, has fast curing speed, low energy consumption, and no solvent pollution, and is convenient for forming microstructures thereon.

And/or, the reflective layer is an electroplated aluminum alloy layer. The reflective layer is an aluminum alloy coating coated on the upper surface of the microstructure layer by electroplating, and the surface of the aluminum alloy coating is smooth and has an excellent reflective effect on light.

A photovoltaic cell assembly, comprising photovoltaic glass, a front packaging material layer, a photovoltaic cell layer, a rear packaging material layer, a gap film and a back plate arranged in sequence from top to bottom; the gap film is any of the gap films described above;

The photovoltaic cell layer includes a plurality of photovoltaic module cells; the gap film is arranged on the back plate and corresponds to and fully covers the gaps between the plurality of photovoltaic module cells of the photovoltaic cell layer.

In a preferred embodiment, according to the distribution of the plurality of photovoltaic module cells in the photovoltaic cell layer, the gap films are arranged longitudinally and transversely on the backplane corresponding to the gaps between the plurality of photovoltaic module cells, and are glued and fixed to the backplane.

Compared with the prior art, the present invention has the following advantages and beneficial effects:

In the gap membrane of the present invention, the microstructure reflective layer is provided with a microstructure of a triangular prism-like structure for light reflection, and both side surfaces of the triangular prism-like structure are inwardly concave arc-shaped side surfaces, which can focus and reflect the incident light, so that the light can be better concentrated and efficiently reused, effectively improving the photoelectric efficiency of the solar photovoltaic module.

In addition, a transition ridge structure is provided between two adjacent triangular prism-like structures to maintain a sufficient spacing between the two adjacent triangular prism-like structures, to avoid the phenomenon of mutual blocking of the light path between the two adjacent triangular prism-like structures, to ensure the light-collecting and reflection efficiency of the triangular prism-like structures, and to effectively improve the power generation efficiency of solar photovoltaic modules. At the same time, the surface of the transition ridge structure is a raised arc surface. When light is incident on its surface, most of it will be reflected on the arc side of the triangular prism-like structure, and then concentrated and reflected to the photovoltaic power generation area. A small part of the light will be directly reflected to the photovoltaic power generation area through its surface. While ensuring the spacing between the two adjacent triangular prism-like structures, it ensures that the light energy irradiated between the two adjacent triangular prism-like structures will not be wasted, and can be effectively concentrated and reused.

The photovoltaic cell assembly of the present invention adopts the above-mentioned gap membrane, which concentrates and reflects the sunlight irradiated on the gaps between the photovoltaic module cells to the photovoltaic power generation area, thereby making efficient use of the sunlight irradiated thereon, reducing the waste of light energy and achieving high photovoltaic power generation efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic structural diagram of a gap film applied to a photovoltaic cell assembly according to a specific embodiment of the present invention;

FIG2 is a schematic diagram of the cross-sectional structure of a gap film applied to a photovoltaic cell assembly according to a specific embodiment of the present invention;

FIG3 is a schematic diagram of the working principle of light reflection by the gap film applied to a photovoltaic cell assembly of the present invention in a specific embodiment;

FIG4 is a schematic diagram of the structure of a photovoltaic cell assembly of the present invention in a specific embodiment;

Figure markings: 1-substrate, 2-back adhesive layer, 3-microstructure reflective layer, 31-microstructure layer, 32-reflective layer, 310-reflective protrusion microstructure, 3101-triangular prism-like structure, 3102-transition ridge structure, 100-photovoltaic glass, 200-front packaging material layer, 300-photovoltaic cell layer, 300a-photovoltaic module cell, 400-rear packaging material layer, 500-gap film, 600-back panel.

DETAILED DESCRIPTION

The technical solution of the present invention is further described in detail below in conjunction with specific embodiments and drawings, but the protection scope and implementation methods of the present invention are not limited thereto. In the description of specific embodiments, it should be noted that the orientation or positional relationship indicated by the terms "left", "right", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use. It is only used to distinguish the description, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the structure or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention, let alone an indication or implication of relative importance. In addition, the term "and/or" used herein includes any and all combinations of one or more related listed items.

Example 1

The gap film applied to the photovoltaic cell module of this embodiment, as shown in FIG1, comprises a substrate 1, a backing layer 2 and a microstructure reflective layer 3. The substrate 1 is a basic structural layer of the film material, the backing layer 2 and the microstructure reflective layer 3 are sequentially stacked on the substrate 1, and the surface of the microstructure layer 3 can reflect the incident light at a changed angle.

When in use, the side of the substrate 1 facing away from the adhesive layer 2 is attached to and covers the gap of the photovoltaic cell assembly, and the microstructure reflective layer 3 is located on the uppermost surface. When sunlight irradiates the gap of the photovoltaic cell assembly, the microstructure reflective layer 3 can reflect the sunlight to the photovoltaic power generation area, avoiding the waste of sunlight incident on the gap, effectively improving the utilization rate of light energy, and further improving the photoelectric efficiency of the photovoltaic cell assembly.

In this embodiment, the upper surface of the microstructure layer 31 is composed of a reflective protruding microstructure 310, which can reflect the incident light at a changed angle. Specifically, the reflective protruding microstructure 310 includes a plurality of strip-shaped triangular prism-like structures 3101, and a transition ridge structure 3102 located between two adjacent triangular prism-like structures 3101. As shown in FIG. 1 , in this embodiment, the triangular prism-like structures 3101 are arranged in an array, and the transition ridge structure 302 is integrally arranged between two adjacent triangular prism-like structures 3101.

As shown in FIG. 2 , in this embodiment, the microstructure reflective layer 3 includes a microstructure layer 31 and a reflective layer 32. The microstructure layer 31 is disposed on the adhesive layer 2, and the upper surface of the microstructure layer 31 has the outline of the reflective convex microstructure 310, that is, it has the basic outline of the triangular prism structure 3101 and the transition ridge structure 3102, and the reflective layer 32 covers the upper surface of the microstructure layer 31. In this way, the reflective layer 32 is formed according to the outline structure of the reflective convex microstructure 310 on the surface of the microstructure layer 31, and has a corresponding angle reflection feature according to the outline structure of the reflective convex microstructure 310 in the reflection effect on sunlight.

Alternatively, in the present embodiment, the substrate 1 is a PET film, the adhesive layer 2 is an EVA hot melt adhesive layer, the microstructure layer 31 is an ultraviolet curing adhesive layer, and the reflective layer 32 is an electroplated aluminum alloy layer. PET film is used as the basic supporting material of the overall gap membrane. It is thin and will not have a significant impact on the thickness of the overall gap membrane, which is conducive to the design of a thinner thickness of the overall gap membrane. During the preparation and molding process, EVA hot-melt adhesive is hot-melt coated on the PET film, which can be quickly cooled and solidified. After solidification, it has high hardness to form a back glue layer 2, which can continue to support the molding of the microstructure layer 31. During the preparation and molding process, ultraviolet curing glue is coated on the back glue layer 2, and then the basic contours of the triangular prism structure 3101 and the transition ridge structure 3102 are engraved on the upper surface. Ultraviolet light can quickly solidify and form a microstructure layer 31, and form a good bonding relationship with the back glue layer 2, with good stability and low energy consumption for structural layer molding. During the preparation and molding process, aluminum alloy is electroplated on the molded microstructure layer 31 to form an electroplated aluminum alloy layer. The surface of the aluminum alloy coating is smooth and has excellent reflective effect on light.

In the reflective protrusion microstructure 310, the left and right sides of the triangular prism-like structure 3101 are light reflecting surfaces, and both are surfaces with an inclined angle to the vertical plane. When light is incident on the two sides of the triangular prism-like structure 3101, it will be reflected by the two sides at a changed angle. Furthermore, in the present embodiment, both sides of the triangular prism-like structure 3101 are arc-shaped sides that are concave inward. As shown in FIG3, both sides of the triangular prism-like structure 301 are configured as arc-shaped sides that are concave inward. In the process of reflecting the incident light, the arc-shaped sides can gather and reflect the incident light, and the reflected light can be gathered and reflected to the photovoltaic power generation area, so that the light can be better concentrated and efficiently reused, effectively improving the photoelectric efficiency of the solar photovoltaic module.

In a preferred embodiment, the height of the triangular prism-like structure 3101 is 13 to 16 μm. The curvature of the arc-shaped side of the triangular prism-like structure 3101 is 0.6 to 1.0 rad. When the height and curvature of the triangular prism-like structure 3101 are determined, the radius of the arc can be uniquely determined, and the corresponding arc length can also be determined. Within this curvature range, the radius of the arc is not too large to cause excessive inward depression, which affects the light-gathering efficiency and reflection efficiency of the arc-shaped side, nor is it too small to make the arc surface tend to be flat, and the effect of light convergence cannot be achieved, so that the light can be better concentrated and reflected for utilization, thereby improving the efficiency of light energy utilization. In this embodiment, the height of the triangular prism-like structure 3101 is 15 μm, and the curvature of the arc-shaped side of the triangular prism-like structure 3101 is 0.8 rad, and the arc-shaped side of the triangular prism-like structure 3101 has a better light-gathering and reflection effect.

In addition, since the triangular prism-like structures 3101 are arranged in an array, when the spacing between them is too close, it is easy to block the light path from each other, reduce the light reflection efficiency of the triangular prism-like structures 3101, and make part of the light reflected multiple times and then reflected back along the incident light path. The transition ridge structure 3102 can maintain the spacing between the triangular prism-like structures 3101, avoid blocking the light path between two adjacent triangular prism-like structures 3101, or reflect light multiple times, and ensure the focusing reflection efficiency of the triangular prism-like structures 3101. At the same time, referring to FIG. 3, based on the surface of the transition ridge structure 3102 being an arc surface, most of the light directly irradiated on the surface of the transition ridge structure 3102 will be reflected on the arc side of the triangular prism-like structure 3101, and then concentrated and reflected to the photovoltaic power generation area, and a small part of the light will be directly reflected to the photovoltaic power generation area through its surface, thereby ensuring that the light energy irradiated between two adjacent triangular prism-like structures 3101 will not be wasted.

In a preferred embodiment, the height of the transition ridge structure 3102 is 2 to 5 μm, and the surface is a raised arc-shaped surface with a radian of 1.8 to 2.2 rad. The height of the transition ridge structure 3102 is selected within this range, and combined with the corresponding surface radian range, the width of the transition ridge structure 3102 can be determined to ensure that there is sufficient spacing between two adjacent triangular prism-like structures 3101, while reducing the waste of light energy and making the utilization efficiency of light energy higher. In this embodiment, the height of the transition ridge structure 3102 is 4 μm, and the surface is a raised arc-shaped surface with a radian of 2.rad. The spacing effect and focusing reflection effect of the transition ridge structure 3102 are better.

Example 2

The photovoltaic cell assembly of this embodiment includes photovoltaic glass 100, front encapsulation material layer 200, photovoltaic cell layer 300, rear encapsulation material layer 400, gap film 500 and back plate 600 arranged in order from top to bottom. The front encapsulation material layer 200 and the rear encapsulation material 400 are both transparent layers that allow sunlight to penetrate; the photovoltaic cell layer 300 includes a plurality of photovoltaic module cells 300a, and the photovoltaic module cells 300a can convert light energy into electrical energy through the photoelectric effect; the gap film 500 is the gap film described in Example 1.

The gap film 500 is disposed on the back plate 600, and corresponds to and fully covers the gaps between the multiple photovoltaic module cells 300a of the photovoltaic cell layer 300. In addition, according to the distribution of the multiple photovoltaic module cells 300a in the photovoltaic cell layer 300, the gap film 500 is arranged longitudinally and transversely on the back plate 600 corresponding to the gaps between the multiple photovoltaic module cells 300a, and is adhered and fixed to the back plate 600.

As shown in FIG. 4 , when working, sunlight penetrates the photovoltaic glass 100 and the front encapsulation material layer 200 and enters the photovoltaic cell layer 300. The photovoltaic module cell 300a on the photovoltaic cell layer 300 performs a photoelectric effect to convert light energy into electrical energy; and the sunlight incident from the gaps between the photovoltaic module cells 300a cannot be directly incident on the photovoltaic module cells 300a for direct use. In order to avoid the waste of light energy, the gap film 500 is set so that after the sunlight penetrates the gaps between the photovoltaic module cells 300a and reaches the surface of the gap film 500, the reflective protrusion microstructure 310 on the surface of the gap film 500 changes the angle of the reflection of the sunlight. The reflected light is obliquely incident on the photovoltaic glass 100, and then further reflected on the photovoltaic module cell 300a for photoelectric conversion. In this way, the sunlight irradiated on the photovoltaic cell assembly can be efficiently utilized, reducing the waste of light energy and improving the efficiency of photovoltaic power generation.

The above embodiments are only preferred embodiments of the present invention and are only intended to further describe the technical solutions of the present invention in detail. However, the protection scope and implementation methods of the present invention are not limited thereto. Any changes, combinations, deletions, replacements or modifications that do not deviate from the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims (6)

1. The gap film applied to the photovoltaic cell assembly is characterized by comprising a base material, a back adhesive layer and a microstructure reflecting layer; the back adhesive layer and the microstructure reflecting layer are sequentially laminated on the base material;

The upper surface of the microstructure reflecting layer is formed by reflecting convex microstructures; the reflecting convex microstructure comprises a plurality of strip-shaped triangular prism-like structures and transition ridge structures positioned between two adjacent triangular prism-like structures; the two side surfaces of the triangular prism-like structure are arc-shaped side surfaces which are concave inwards;

the height of the triangular prism-like structure is 13-16 mu m;

The radian of the arc-shaped side surface of the triangular prism-like structure is 0.6-1.0 rad;

The height of the transition ridge structure is 2-5 mu m, and the surface is a raised arc-shaped surface with the radian of 1.8-2.2 rad.

2. The gap film for a photovoltaic cell assembly according to claim 1, wherein the triangular prism-like structures are arranged in an array, and the transitional ridge structures are integrally arranged between two adjacent triangular prism-like structures.

3. The gap film for a photovoltaic cell assembly according to any one of claims 1-2, wherein the microstructured reflective layer comprises a microstructured layer and a reflective layer; the micro-structure layer is arranged on the gum layer, the upper surface of the micro-structure layer is provided with a profile of the reflective convex micro-structure, and the reflective layer covers the upper surface of the micro-structure layer.

4. A spacer film for use in a photovoltaic cell assembly according to claim 3, wherein the substrate is a PET film;

And/or, the back adhesive layer is an EVA hot-melt adhesive layer;

and/or the microstructure layer is an ultraviolet solid glue layer;

and/or the light reflecting layer is an electroplated aluminum alloy layer.

5. A photovoltaic cell assembly comprises photovoltaic glass, a front packaging material layer, a photovoltaic cell layer, a rear packaging material layer, a gap film and a back plate which are sequentially arranged from top to bottom; the gap film is the gap film according to any one of claims 1 to 4;

the photovoltaic cell layer comprises a plurality of photovoltaic module cells; the gap film is arranged on the back plate and corresponds to and fully covers gaps among a plurality of photovoltaic module cells of the photovoltaic cell layer.

6. The photovoltaic cell assembly according to claim 5, wherein the gap film is arranged longitudinally and transversely on the back plate corresponding to gaps among the plurality of photovoltaic module cells according to the distribution mode of the plurality of photovoltaic module cells in the photovoltaic cell layer, and is adhered and fixed on the back plate.