TECHNICAL FIELD

The present invention relates to a solar energy collector .

BACKGROUND

Solar energy is the most abundant energy resource on the earth and may be defined as radiant energy (heat or light) emitted from the sun to the earth. Recently it has been drawing attention in production of electric energy using such solar energy.

There are two well known methods of harvesting solar energy into the energy we need. One is photovoltaic and the other is Concentrated Solar Power (CSP) .

However, the photovoltaic system has low power generation efficiency and therefore has a disadvantage that light collecting plates should be installed in a wide range in order to cover the required power amount. Furthermore, the photovoltaic system cannot generate electricity when the sun is diming due to the cloud. Therefore, the photovoltaic system has a drawback that a very-expensive large-capacity battery for storing energy needs to be used in order to supply electricity when the solar light is weak. For this reason., there is a limit to using the photovoltaic system for commercial power generation. On the other hand, the current CSP systems require a massive initial investment due to its large infrastructural needs, and the current efficiency of the system is not justifiable to its high levelized cost of electricity.

As a result, it is required to improve the photovoltaic collection efficiency and the stable electricity generation of the CSP system and to decrease the energy production cost of the CSP system and the cost of installing the CSP system.

[Prior Art document]

(Patent Document 1) : Korean Patent Publication No. 10- 1052120 (published on July 20, 2011) SUMMARY

Embodiments of the present invention provide a solar energy collector capable of effectively collecting solar energy .

In accordance with an aspect of the present invention, there is provided a solar energy collector, including: a solar energy collection pipe having an absorption medium flow path for allowing an energy absorption medium to flow therethrough; and at least one lens configured to concentrate solar energy on the solar energy collection pipe Further, the solar energy collection pipe includes: a solar energy collection body portion including a solar energy collection portion through which the solar energy concentrated by the lens is transmitted into the solar energy collection pipe; and an insulating portion configured to cover at least a part of a remaining portion of the solar energy collection body portion other than the solar energy collection portion.

Further, the insulating portion may be disposed to make contact with the solar energy collection body portion, and the insulating portion may be removable from the solar energy collection body portion.

Further, the solar energy collection pipe may include: a solar energy collection support portion configured to provide the absorption medium flow path; an insulating portion configured to cover the solar energy collection support portion; and a solar energy collection window portion connected to the solar energy collection support portion so that the solar energy passes through the solar energy collection window portion, wherein the solar energy collection window portion has an arc-shaped cross section whose radius of curvature is the same as a radius of curvature of the solar energy collection support portion.

Further, the solar energy collection pipe may further include a heat reflector portion disposed on an inner surface of the solar energy collection support portion, and the heat reflector portion may have an arc- shaped cross section and is concentrically disposed with respect to the solar energy collection support portion.

Further, the solar energy collector may further include: a collector pipe spaced apart by a predetermined distance from the solar energy collection pipe and configured to cover the solar energy collection pipe, wherein the collector pipe may include a collector body portion and a collector window portion including a focusing portion configured to transmit the solar energy concentrated by the lens into the collector pipe.

Further, the lens may be configured to concentrate the solar energy toward the center of the solar energy collection pipe, the lens extending along a longitudinal direction of the solar energy collection pipe, the lens having a thickness that grows larger toward the center in a- width direction or a thickness that grows larger from one end toward the other end in the width direction.

Further, the solar energy collection window portion may include a one-way window configured to suppress transfer of radiant solar energy in a direction opposite to an incidence direction of the solar energy.

Further, the collector pipe may further include a reflector portion provided on an inner surface of the collector body portion.

Further, the collector body portion may further include an absorption portion coated with an absorption material for absorbing the solar energy. Further, the collector window portion may include a one-way window configured to suppress transfer of radiant solar energy in a direction opposite to an incidence direction of the solar energy.

Further, the solar energy collector may further include: a detection sensor configured to measure an incidence angle of the solar energy; an actuator configured to rotate the solar energy collection pipe, the collector pipe and the lens; and a controller configured to control an operation of the actuator based on the incidence angle measured by the detection sensor, wherein the solar energy collection pipe, the collector pipe and the lens are rotated under the control of the controller so that a solar energy collection window portion, the collector window portion and the lens are arranged in an incidence direction of the solar energy .

Further, the lens may include a Fresnel lens disposed so that a focal line passes through an edge of the lens.

Further, the lens may include a Fresnel lens disposed so that a focal line passes through between a center and an edge of the lens .

Further, the lens may include two or more lenses.

According to the embodiments of the present invention, it is possible to effectively collect solar energy through a solar energy collection pipe. This makes it possible to stably supply heat required for CSP power generation. BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a perspective view showing a solar energy collector according to a first embodiment of the present invention.

Fig. 2 is a sectional view taken along line II-II in Fig. 1.

Figs. 3A to 3C are views showing lenses for a solar energy collector according to modifications of the first embodiment.

Fig. 4 is a view showing a lens for a solar energy collector according to another modification of the first embodiment .

Fig. 5 is a perspective view showing a solar energy collector according to a second embodiment of the present invention.

Fig. 6 is a sectional view taken along line VI-VI in Fig. 5.

Fig. 7 is a perspective view showing a solar energy collector according to a third embodiment of the present invention.

Fig. 8 is a sectional view taken along line VIII-VIII in Fig. 7.

Fig. 9 is a perspective view showing a solar energy collector according to a fourth embodiment of the present invention . Fig. 10 is a sectional view taken along line X-X in Fig. 9.

Fig. 11 is a perspective view showing a solar energy collector according to a fifth embodiment of the present invention.

Fig. 12 is a sectional view taken along line XII-XII in Fig. 11.

Fig. 13 is a perspective view showing a solar energy collector according to a modification of the fifth embodiment.

Fig. 14 is a sectional view taken along line XIV-XIV in Fig. 13.

Fig. 15 is a diagram showing a solar energy collector according to a sixth embodiment of the present invention.

DETAILED DESCRIPTION

Hereinafter, configurations and operations of embodiments will be described in detail with reference to the accompanying drawings. The following description is one of various patentable aspects of the invention and may form a part of the detailed description of the invention.

However, in describing the invention, detailed descriptions of known configurations or functions that make the invention obscure may be omitted.

The invention may be variously modified and may include various embodiments. Specific embodiments will be exemplarily illustrated in the drawings and described in the detailed description of the embodiments. However, it should be understood that they are not intended to limit the invention to specific embodiments but rather to cover all modifications, similarities, and alternatives which are included in the spirit and scope of the invention.

The terms used herein, including ordinal numbers such as "first" and "second" may be used to describe, and not to limit, various components. The terms simply distinguish the components from one another. When it is said that a component is "connected" "coupled" or "linked" to another component, it should be understood that the former component may be directly connected or linked to the latter component or a third component may be interposed between the two components. Specific terms used in the present application are used simply to describe specific embodiments without limiting the invention. An expression used in the singular encompasses the expression of the plural, unless it has a clearly different meaning in the context .

Fig- 1 is a perspective view showing a solar energy collector according to a first embodiment of the present invention. Fig. 2 is a sectional view taken along line II- II in Fig. 1.

As shown in Figs. 1 and 2, the solar energy collector according to a first embodiment of the present invention may include a solar energy collection pipe 100 having a hollow tubular shape and a lens 200 for concentrating solar energy on the solar energy collection pipe 100.

The solar energy collection pipe 100 may have a tubular shape extending in one direction. An absorption medium flow path through which an energy absorption medium can flow may be provided inside the solar energy collection pipe 100. The absorption medium flow path W may be formed to extend in the longitudinal direction (one direction) of the solar energy collection pipe 100. The energy absorption medium may flow along the longitudinal direction in the absorption medium flow path W. Furthermore, the energy absorption medium may be heated by the solar energy incident on the solar energy collection pipe 100 through the lens 200 while the energy absorption medium flows through the absorption medium flow path W. In this regard, the energy absorption medium may include all kinds of fluid capable of absorbing solar energy (solar radiant heat) and movable along the absorption medium flow path W. For example, the energy absorption medium may be air, a volatile fluid (methanol, acetone, mercury, etc.), water (including water vapor), oil, an ethylene glycol mixture, and the like. The energy absorption medium heated in the absorption medium flow path W may be moved toward a thermal energy utilizing apparatus (not shown) such as a generator or the like. The energy absorption medium moved to the generator may be used as a heat source of the generator for the generation of electricity.

The solar energy collection pipe 100 may be made of a material having high heat conductivity or a material capable of allowing solar energy to pass therethrough. As an example, the solar energy collection pipe 100 may be made of a material having high heat conductivity, such as aluminum, copper or an alloy thereof, or a material capable of effectively allowing solar energy to pass therethrough, such as glass, quartz, transparent plastic or the like.

The solar energy collection pipe 100 may be in the form of a tube having an annular cross section. Needless to say, the present invention is not limited thereto. The solar energy collection pipe 100 may have various cross- sectional shapes. For example, the solar energy collection pipe 100 may have an elliptical ring-shaped cross section or a polygonal ring-shaped cross section.

The lens 200 may refract solar energy so that the solar energy is concentrated on the solar energy collection pipe 100. The lens 200 may have a bar shape extending along the longitudinal direction of the solar energy collection pipe 100. In order to efficiently collect solar energy, the lens 200 may have a larger width (vertical dimension in Fig. 2) than the solar energy collection pipe 100.

Furthermore, the lens 200 may have a shape of a bar disposed parallel to a longitudinal axis O passing through the center of the solar energy collection pipe 100. The lens 200 may focus the solar energy incident on the lens 200 toward the longitudinal axis 0 and the internal center of the solar energy collection pipe 100. In other words, the lens 200 may have a convex shape when viewed in a cross section perpendicular to the longitudinal direction. That is to say, the transverse central portion of the lens 200 may have a larger thickness than the transverse end portions In the present embodiment, the lens 200 has a bar shape. However, the present invention is not limited thereto. The lens 200 may be a flat lens such as a Fresnel lens or the like.

Figs. 3A to 3C are views showing lenses for a solar energy collector according to modifications of the first embodiment. Fig. 4 is a view showing a lens for a solar energy collector according to another modification of the first embodiment.

According to the modifications, as shown in Fig. 3A, the lens 200 may include one Fresnel lens whose focal line passes through an edge thereof. The term "focal line" may be defined as a path of light passing through a focal point of the lens 200 without being refracted. That is to say, the focal line refers to a path passing through the focal point of the lens 200 in a direction perpendicular to the lens 200. As shown in Fig. 3B, the lens 200 may include two Fresnel lenses 201a and 201b whose focal lines pass through the edges thereof. The two Fresnel lenses 201a and 201b may be disposed so as to have the same focal line. In addition, the two Fresnel lenses 201a and 201b may be disposed in a syrometrical relationship with each other.

As shown in Fig. 3C, the lens 200 may include a Fresnel lens 201d whose focal line passes through between the center and the edge thereof. However, the present invention is not limited thereto.

According to another modification, as shown in Fig. 4, the lens 200 may include two or more Fresnel lenses 201a, 202a, 203a, 201b, 202b, 203b and so forth, and may be disposed so as to have the same focal line. The focal line may pass through the lens 200 (e.g., the Fresnel lenses 203a and 203b in Fig. 4) and may not pass through the lens 200 (e.g., the Fresnel lenses 201a, 201b, 202a and 202b in Fig. 4) .

In the present embodiment, the bar-shaped lens 200 having a convex central portion when viewed in a cross section perpendicular to the longitudinal direction is used to concentrate solar energy on the solar energy collection pipe 100. However, the present invention is not limited thereto. Various types of lenses or reflectors may be applied to the present embodiment as long as they can concentrate solar energy on the solar energy collection pipe 100. For example, a plurality of convex lenses may be disposed along the longitudinal direction of the solar energy collection pipe 100. It may also be possible to use a bar- shaped reflector having a concave central portion in the width direction.

Fig. 5 is a perspective view showing a solar energy- collector according to a second embodiment of the present invention. Fig. 6 is a sectional view taken along line VI- VI in Fig. 5.

As shown in Figs. 5 and 6, according to the second embodiment of the present invention, the solar energy collection pipe 100 of the solar energy collector may further include a solar energy collection body portion 110 and an insulating portion 120. Hereinafter, the second embodiment of the present invention will be described with an emphasis placed on the difference between the first embodiment and the second embodiment. The same portions as those of the first embodiment will be designated by the same reference numerals and will not be described again.

The solar energy collection body portion 110 may be divided into a solar energy collection portion F that allows solar energy incident on the lens 200 to enter the solar energy collection pipe 100, and a remaining portion other than the solar energy collection portion F. The insulating portion 120 for minimizing leakage of heat may be provided in the remaining portion other than the solar energy collection portion F. The insulating portion 120 may not surround the entirety of the remaining portion but may partially surround the remaining portion. For example, the solar energy collection pipe 100 may receive the solar energy incident on the lens 200 through the solar energy collection portion F and the insulating portion 120 may prevent the solar energy in the solar energy collection pipe 100 from being leaked to the outside of the solar energy collection pipe 100. In other words, the insulating portion 120 is capable of minimizing a heat loss in the solar energy collection pipe 100.

The solar energy collection body portion 110 may be made of a material having high conductivity. For example, the solar energy collection pipe 100 may be made of aluminum, copper or an alloy thereof which is high in heat conductivity. The material of the solar energy collection body portion 110 may be selected in consideration of the strength at the expected highest temperature in the solar energy collection pipe 100, the insulating property, the corrosion resistance, the cost and the like. The cross section of the solar energy collection body portion 110 may be an arc shape or a circular shape having a predetermined radius of curvature.

The insulating portion 120 may be disposed to surround the remaining portion of the solar energy collection body portion 110 in order to insulate the remaining portion of the solar energy collection body portion 110 other than the solar energy collection portion F. The insulating portion 120 may be a member such as a film or the like removably disposed close to the solar energy collection body portion 110 or a coating layer integrally formed with the surface of the solar energy collection body portion 110 by vapor deposition. As one example, the solar energy collection body portion 110 may be an insulating material such as an urethane insulating material, a spring metal insulating material, a vinyl insulating material, a foamed rubber insulating material, polystyrene insulating material (foamed spongy), an insulating film or the like. In addition, various types of materials for insulating the solar energy collection pipe 100 may be used as the material of the insulating portion 120.

Fig. 7 is a perspective view showing a solar energy collector according to a third embodiment of the present invention. Fig. 8 is a sectional view taken along line VIII-VIII in Fig. 7.

As shown in Figs. 7 and 8, according to the third embodiment of the present invention, the solar energy collection pipe 100 of the solar energy collector may include a solar energy collection support portion 110', an insulating portion 120 and a solar energy collection window portion 130.

The solar energy collection support portion 110' may have a shape corresponding to a part of a cylinder. The solar energy collection support portion 110' may have an arc-shaped cross section. The solar energy collection window portion 130 may have a shape corresponding to the other part of the cylinder. The solar energy collection window portion 130 may have an arc-shaped cross section. The combination of the solar energy collection support portion 110' and the solar energy collection window portion 130 may have a shape (i.e., a cylindrical shape) corresponding to the solar energy collection body portion 110 described above. The solar energy collection window portion 130 may be connected to the solar energy collection support portion 110' and the insulating portion 120. Hereinafter, the third embodiment of the present invention will be described with an emphasis placed on the difference between the aforementioned embodiments and the third embodiment. The same portions as those of the aforementioned embodiments will be designated by the same reference numerals and will not be described again.

The solar energy collection window portion 130 may be disposed in a solar energy collection portion F on which solar energy is intensively irradiated, and may be formed so as to allow solar energy to pass therethrough. For example, the solar energy collection window portion 130 may be a oneway window that permits transfer of radiant solar energy only in one direction in which solar energy is incident and prevents transfer of radiant solar energy in the other direction opposite to one direction. The cross section of the solar energy collection window portion 130 may have an arc shape having substantially the same radius of curvature as the radius of curvature of the solar energy collection support portion 110'. However, the present invention is not limited thereto. The solar energy collection window portion 130 may be configured to have a flat shape.

In the present embodiment, the solar energy collection window portion 130 may be formed of, for example, a polarizing glass capable of transmitting solar energy. Alternatively, the solar energy collection window portion 130 may be formed of a polarizing film or a polarizing plastic that permits transfer of radiant solar energy only in one direction in which solar energy is incident.

Fig. 9 is a perspective view showing a solar energy collector according to a fourth embodiment of the present invention. Fig. 10 is a sectional view taken along line X-X in Fig. 9.

As shown in Figs. 9 and 10, according to the fourth embodiment of the present invention, the solar energy collection pipe 100 of the solar energy collector may further include a heat reflector portion 140. Hereinafter, the fourth embodiment of the present invention will be described with an emphasis placed on the difference between the aforementioned embodiments and the fourth embodiment. The same portions as those of the aforementioned embodiments will be designated by the same reference numerals and will not be described again. The heat reflector portion 140 is capable of reflecting solar energy incident in the solar energy collection pipe 100. The heat reflector portion 140 may be provided on the inner surface of the solar energy collection support portion 110' . The heat reflector portion 140 may be a member such as a film or the like disposed on the inner surface of the solar energy collection support portion 110' or may be a coating layer integrally formed with the inner surface of the solar energy collection support portion 110' by vapor deposition. The cross section of the heat reflector portion 140 may be concentric with that of the solar energy collection support portion 110' and may be configured to have an arc shape or a circular shape.

Fig. 11 is a perspective view showing a solar energy collector according to a fifth embodiment of the present invention. Fig. 12 is a sectional view taken along line XII-XII in Fig. 11.

As shown in Figs. 11 and 12, according to the fifth embodiment of the present invention, the solar energy collector may further include a collector pipe 300. Hereinafter, the fifth embodiment of the present invention will be described with an emphasis placed on the difference between the aforementioned embodiments and the fifth embodiment. The same portions as those of the aforementioned embodiments will be designated by the same reference numerals and will not be described again. The collector pipe 300 may be concentrically disposed with respect to the solar energy collection pipe 100 so as to surround the solar energy collection pipe 100 and may have a tubular shape extending in one direction. The collector pipe 300 may transfer the solar energy incident on the collector pipe 300 to the solar energy collection pipe 100. To this end, the collector pipe 300 may be made of a material having high heat conductivity. For example, the collector pipe 300 may be made of aluminum, copper or an alloy thereof, which is high in heat conductivity.

The solar energy collection pipe 100 may be disposed inside the collector pipe 300. A void V may be formed between the inner surface of the collector pipe 300 and the outer surface of the solar energy collection pipe 100. The void V may be an empty space which is not subjected to an insulating treatment such as filling of an insulating material or the like. The void V is capable of effectively transferring the solar energy incident inward of the collector pipe 300 to the solar energy collection pipe 100 with no loss of heat.

The collector pipe 300 may include a tubular collector body portion 310 spaced apart by a predetermined distance from the outer surface of the solar energy collection pipe 100, and a collector window portion 330 formed in a focusing portion of the collector pipe 300. The focusing portion may refer to the portion of the collector pipe 300 through which the solar energy focused by the lens 200 passes. The separation distance between the inner surface of the collector body portion 310 and the outer surface of the solar energy collection pipe 100 may be kept constant along the circumference of the outer surface of the solar energy collection pipe 100 and may be kept constant along the longitudinal direction of the solar energy collection pipe 100.

The collector window portion 330 may be a one-way window (e.g., a polarizing glass) that permits transfer of radiant solar energy only in one direction in which solar energy is incident.

In the present embodiment, the collector pipe 300 may have a tubular shape with a circular ring-shaped cross section. However, the present invention is not limited thereto. The collector pipe 300 may be in the form of a tube having various cross sections. For example, the collector pipe 300 may have an elliptical ring-shaped cross section or a polygonal ring-shaped cross section.

Fig. 13 is a perspective view showing a solar energy collector according to a modification of the fifth embodiment. Fig. 14 is a sectional view taken along line XIV-XIV in Fig. 13.

Hereinafter, the modification of the fifth embodiment of the present invention will be described with an emphasis placed on the difference between the aforementioned embodiments and the modification of the fifth embodiment. The same portions as those of the aforementioned embodiments will be designated by the same reference numerals and will not be described again.

As shown in Figs. 13 to 14, the collector body portion

310 may further include an absorption portion 311 coated with an absorption material for effective absorption of solar energy. The collector pipe 300 may further include a reflector portion 340. In this regard, the absorption material may include Al ₂ 0 ₃ , Al ₂ 0 ₃ +Mo+Al ₂ 0 ₃ , TiNO _x , Solkote and other like materials. For example, in the present embodiment, TiNO _x (a product of Almeco Solar, Inc.) or Solkote (a product of Solec Solar Energy Corp.) may be used as the absorption material.

The reflector portion 340 may provide a reflection surface for reflecting solar energy incident inward of the collector pipe 300 to the inner surface of the collector body portion 310. In the reflector portion 340, a reflection material may be coated on the inner surface of the reflector portion 340 or may be integrally formed with the inner surface of the collector body portion 310.

In the present embodiment, the configuration of the solar energy collection pipe 100 is the same as the configuration of the solar energy collection pipe 100 of the first embodiment described above. However, depending on the installation environment of the solar energy collector of the present invention, the configuration of the solar energy collection pipe 100 according to the present embodiment may be changed to the configuration of the solar energy collection pipe 100 of the second embodiment, the third embodiment or the fourth embodiment described above .

Fig. 15 is a diagram showing a solar energy collector according to a sixth embodiment of the present invention.

As shown in Fig. 15, the solar energy collector according to the sixth embodiment of the present invention may further include a detection sensor 400, an actuator 500 and a controller 600. Hereinafter, the sixth embodiment of the present invention will be described with an emphasis placed on the difference between the aforementioned embodiments and the sixth embodiment. The same portions as those of the aforementioned embodiments will be designated by the same reference numerals and will not be described again .

The detection sensor 400 may measure the incident angle of solar energy in real time. For example, the detection sensor 400 may measure the incident angle of solar energy at predetermined time intervals and may apply the measured incident angle information to the controller 600.

The actuator 500 may rotate the solar energy collection pipe 100, the collector pipe 300 and the lens 200 by a predetermined angle. The actuator 500 may be installed in an actuation frame (not shown) and may provide a rotational force to the actuation frame.

Therefore, when an actuation signal is applied from the controller 600 to the actuator 500, the actuation frame holding the solar energy collection pipe 100, the collector pipe 300 and the lens 200 may be rotated by the actuator 500. By the rotation of the actuation frame, the solar energy collection window portion 130, the collector window portion 330 and the lens 200 may be kept parallel to the solar energy irradiation direction.

Upon receiving the angle information on the incidence angle of solar energy from the detection sensor 400, the controller 600 may rotate the solar energy collection window portion 130, the collector window portion 330 and the lens 200 in conformity with the angle information on the incidence angle applied from the detection sensor 400. For example, the controller 600 may rotate the solar energy collection pipe 100 and the collector pipe 300 so that the solar energy collection window portion 130 and the collector window portion 330 can face the incidence direction of solar energy, and may rotate the lens 200 so that the solar energy can be on average incident in a direction substantially perpendicular to the longitudinal direction and the width direction of the lens 200. The controller 600 may be realized by an operation device including a microprocessor. The method of realizing the controller 600 is apparent to those having an ordinary knowledge in the art and, therefore, will not be described in detail.

For example, when the detection sensor 400 applies the angle information on the incidence angle of solar energy to the controller 600, the controller 600 may apply an actuation signal for rotating the solar energy collection pipe 100, the collector pipe 300 and the lens 200 based on the angle information of the detection sensor 400 to the actuator 500. The actuator 500 controlled by the controller 600 may rotate the solar energy collection window portion 130, the collector window portion 330 and the lens 200 to be arranged parallel to the irradiation direction of solar energy. This makes it possible to enhance the collection efficiency of solar energy.

As described above, the solar energy collector of the present invention is capable of effectively collect solar energy through the use of the solar energy collection pipe. This makes it possible to stably supply a heat source required for photovoltaic generation. By adjusting the light collection direction of the solar energy collector in conformity with the irradiation direction of solar energy, it is possible to enhance the light collection efficiency.

Although exemplary embodiments of the present invention are described above with reference to the accompanying drawings, those skilled in the art will understand that the present invention may be implemented in various ways without changing the necessary features or the spirit of the present invention. For example, those skilled in the art may change material, size, or the like of the each component depending on an application field, or may combine or substitute the embodiments in a form that is not explicitly disclosed in the embodiments of the present invention, which is not departed from the scope of the present invention. Therefore, it should be understood that the exemplary embodiments described above are not limiting, but only exemplary in all respects, and various modifications should be included the scope and spirit disclosed in claims of the present invention.

Explanation of symbols

100: solar energy collection pipe

110: solar energy collection body portion

120: insulating portion

130: solar energy collection window portion

140: heat reflector portion

200: lens 300: collector pipe

310: collector body portion

330: collector window portion

340: reflector portion

400: detection sensor 500: actuator

600: controller