CN107178915A - The paraboloid of revolution type solar collecting device of point focusing twice - Google Patents

Abstract

The invention relates to a rotating paraboloid solar collector with double point focusing, comprising: a heat collector, a secondary concentrator and a bracket, the heat collector includes a primary concentrator and a heat collecting tube, and the primary concentrator is a rotating paraboloid reflector; the secondary concentrator is a rotating parabolic reflector or a circular Fresnel reflector; the heat collecting tube is located between the primary concentrator and the secondary At the focusing point of the secondary concentrator; the bracket is used to support the primary concentrator, secondary concentrator and heat collecting tube. The point-focused solar collection device provided by the present invention adds a secondary concentrator whose lower surface is provided with a rotating parabolic reflector, and the heat collector is located between the secondary concentrator and the primary concentrator, and is located between the secondary concentrator and the primary concentrator. At the focus point of the optical device, the sunlight passing through the heat collector can be reflected to the rotating parabolic reflector again, and then gathered to the heat collector again, with less light loss and high heat collection efficiency.

Description

Rotating Parabolic Solar Collector with Twice Point Focusing

technical field

The invention relates to a rotating parabolic solar energy collection device with double point focusing, in particular to a solar energy collection device with high light-to-heat conversion efficiency.

Background technique

The heat collector is a device that controls the optical path of radiated parallel rays through the reflective surface, increases the heating power of the object, and thereby increases the temperature of the object. From the perspective of optical path control and focusing, there are two types of focusing and non-focusing; among them, the heating power of the focusing collector is greater than that of the non-focusing collector, which can achieve a higher heating temperature. For focusing collectors, there are two main types: line focusing and point focusing. Line focusing means that parallel light rays are focused into a line shape; point focus means that parallel light rays are focused into a point shape.

Condensation ratio is an important technical index of the light-concentrating reflective surface. Different concentration ratios will affect the heating power of the heated object and the temperature range that can be reached. The focusing ratio mainly depends on the form of the focusing reflective surface. According to whether the optical path penetrates the reflective surface, there are reflective and transmissive. Reflective focusing reflectors currently mainly include parabolic and Fresnel types; according to the difference between line focus and point focus, there are paraboloid and line focus Fresnel reflectors; rotating paraboloids and circular Fresnel reflectors. As a result, two technical routes of trough-type concentrating and dish-type concentrating have been produced in engineering, and related technical routes, products and applications have been produced.

There are direct type and indirect type for the absorption of radiation energy by the heated object in the collector; the direct type is to use the medium to directly absorb radiation energy and convert it into an increase in its own temperature; the indirect type is to use the coating to absorb radiation energy, and the coating temperature rises. After high, the heat is transferred to the heated medium, thereby increasing the temperature of the medium.

The technical improvement scheme of the direct absorption type is mainly implemented to increase the concentration ratio of the incident light path, and the concentration ratio of different types of concentrators is very different: the range of concentration ratio of the rotating parabolic concentrator is very high , about 500 to 3000; the concentration ratio of the parabolic cylindrical collector is about 20 to 80; the concentration ratio of the linear Fresnel lens collector is about 6 to 30; the circular Fresnel lens The light concentration ratio range of the concentrating heat collector is relatively high, about 100 to 1000; the light concentration ratio range of the linear Fresnel reflector light concentrating heat collector is about 15 to 50. Therefore, with different concentrators or combinations of concentrators, the light collection efficiency of the device also has a large difference. This patent is mainly aimed at collecting and utilizing this part of the light, thereby improving the optical/photothermal efficiency of the device.

Contents of the invention

The technical problem to be solved by the present invention is: in order to solve the problem of high unit cost and low heat collection efficiency of existing medium-temperature solar collectors, the present invention provides a rotating parabolic solar collector with double point focusing. On the basis of the existing technology, a secondary concentrator is added. The secondary concentrator is a rotating parabolic reflector or a circular Fresnel reflector. The heat collecting tube is located between the secondary concentrator and the primary concentrator. At the same time, it is at the focal point of the secondary concentrator and the primary concentrator, which can reflect the sunlight passing through the heat collecting tube to the primary concentrator again, and gather it to the heat collector again, so that the light loss is small and the collection High thermal efficiency.

The technical solution adopted by the present invention to solve the technical problem is: a rotating parabolic solar collector with two points of focus, comprising: a heat collector, a secondary concentrator and a bracket,

The heat collector includes a primary concentrator and a heat collecting tube, the primary concentrator is a rotating parabolic mirror, and the rotating parabolic mirror has a focal point;

The secondary light concentrator is a rotating parabolic reflector or a circular Fresnel reflector, and the secondary light concentrator has a focal point;

The heat collection tube is located between the primary concentrator and the secondary concentrator, and the heat collection tube is at the focal point of the primary concentrator and the secondary concentrator at the same time, and the heat collection tube carries an energy-absorbing medium

The bracket is used to support the primary concentrator, the secondary concentrator and the heat collecting tube.

Specifically, the above-mentioned heat collecting tube is ellipsoidal, spherical or square.

Specifically, the above-mentioned heat collecting tube is a vacuum tube, including an outer tube and an inner tube, the interlayer between the outer tube and the inner tube is a vacuum, and the inner tube carries an energy-absorbing medium.

Specifically, the above-mentioned outer tube and inner tube are light-transmitting tubes.

Specifically, the above-mentioned outer tube is made of glass, PMMA or PC.

Specifically, the inner tube is made of glass, PMMA or PC.

Specifically, a solar tracking device is also included.

The beneficial effects of the present invention are:

(1) The present invention provides a rotating parabolic solar collector with two points of focus. On the basis of the prior art, a secondary concentrator is added. The secondary concentrator is a rotating parabolic reflector or a circular The Fresnel reflector, the heat collecting tube is located between the secondary concentrator and the primary concentrator, and is at the focal point of the secondary concentrator, which can pass the sunlight through the heat collecting tube through secondary concentrating The light from the collector is reflected to the primary concentrator again, and then collected to the heat collecting tube again, with less light loss and high heat collection efficiency.

(2) the present invention provides a kind of rotating parabolic solar energy collection device of twice point focusing, and outer tube and inner layer tube are all light-transmitting tubes, can make the light after the focusing of rotating parabolic reflector be absorbed by heat collecting tube, The unabsorbed light will pass through the heat collecting tube to the secondary concentrator, convert it into parallel light, and be refocused by the primary concentrator to be absorbed in the heat collecting tube, further improving the heat collection efficiency of the solar energy collection device.

(3) the present invention provides a kind of rotating parabolic surface solar energy collection device of twice point focusing, on the basis of prior art, has set up secondary concentrator, can effectively prevent wind and sand, rain and snow etc. The service life of the heat collecting tube is effectively extended, and the service life of the solar energy collecting device is extended.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Fig. 1 is a schematic view of the optical path of a rotating parabolic mirror enhanced rotating parabolic mirror point-focused solar collector of the present invention;

Fig. 2 is a structural representation of a rotating parabolic reflector enhanced rotating parabolic reflector point-focused solar collection device of the present invention;

Fig. 3 is a kind of circular Fresnel reflector of the present invention strengthens the optical path schematic diagram of rotating parabolic reflector point-focused solar collector;

Fig. 4 is a kind of circular Fresnel reflector of the present invention strengthens the structural representation of rotating parabolic reflector point-focused solar collector;

Fig. 5 is a preferred local structure schematic diagram of a rotating parabolic solar energy collecting device heat collecting tube of a kind of twice point focusing of the present invention;

In the figure: 1. heat collector, 11. primary concentrator, 12. heat collecting tube, 2. bracket, 3. secondary concentrator, 121. outer tube, 122. inner tube, 4. solar tracking device .

detailed description

The present invention is described in further detail now in conjunction with accompanying drawing. These drawings are all simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, so they only show the configurations related to the present invention.

Example 1

As shown in Figure 2, a rotating parabolic mirror enhanced rotating parabolic mirror point-focused solar collection device, including: a heat collector 1, a secondary concentrator 3 and a bracket 2

The heat collector 1 includes a primary concentrator 11 and a heat collecting tube 12, the primary concentrator 11 is a rotating parabolic mirror, and the rotating parabolic mirror has a focal point;

The secondary concentrator 3 is a rotating parabolic reflector, and the secondary concentrator 3 has a focal point;

The heat collection tube 12 is located between the primary concentrator 11 and the secondary concentrator 3, and the heat collection tube 12 is at the focal point of the primary concentrator 11 and the secondary concentrator 3 at the same time, and the heat collection tube 12 is loaded with energy absorption medium;

The bracket 2 is used to support the primary concentrator 11 , the secondary concentrator 3 and the heat collecting tube 12 .

A rotating parabolic reflector of the present invention enhances the point-focusing solar collection device of the rotating parabolic reflector. The focus of the rotating parabolic reflector of the optical device 11 is gathered in the heat collecting tube 12, and the light transmitted through the heat collecting tube 12 reaches the secondary concentrator 3, and the secondary concentrator 3 converts the received light into parallel light, which is directly incident on the The rotating parabolic mirror of the primary concentrator 11 performs refocusing until the light is completely absorbed.

Example 2

As shown in Figure 4, a circular Fresnel reflector enhanced rotating parabolic reflector point-focused solar collection device, including: heat collector 1, secondary concentrator 3 and support 2

The heat collector 1 includes a primary concentrator 11 and a heat collecting tube 12, the primary concentrator 11 is a rotating parabolic mirror, and the rotating parabolic mirror has a focal point;

The secondary concentrator 3 is a circular Fresnel reflector, and the secondary concentrator 3 has a focal point;

The heat collection tube 12 is located between the primary concentrator 11 and the secondary concentrator 3, and the heat collection tube 12 is at the focal point of the primary concentrator 11 and the secondary concentrator 3 at the same time, and the heat collection tube 12 is loaded with energy absorption medium;

The bracket 2 is used to support the primary concentrator 11 , the secondary concentrator 3 and the heat collecting tube 12 .

A kind of circular Fresnel reflector of the present invention strengthens the rotating parabolic reflector point-focusing solar collection device, and its light path is shown in Figure 3, and parallel light rays are first irradiated on the rotating parabolic reflector of primary concentrator 11, and the light After being focused by the rotating parabolic reflector of the primary concentrator 11, it is gathered in the heat collecting tube 12, and the light transmitted through the heat collecting tube 12 reaches the secondary concentrator 3, and the secondary concentrator 3 converts the received light into parallel light, It is directly incident on the rotating parabolic mirror of the primary concentrator 11 for refocusing until the light is completely absorbed.

In a specific embodiment, the heat collecting tube 12 is ellipsoidal, spherical or square. In this specific embodiment, the section of the heat collecting tube 12 is spherical, and has a pipeline for carrying the energy absorbing medium, including a feed pipe 123 and a discharge pipe 124. The pipeline is used to carry the energy absorbing medium on the one hand, and the other On the one hand, it is used to support the heat collecting tube 12 so that it is at the focal point of the primary concentrator 11 and the secondary concentrator 3 .

In a specific embodiment, the solar energy collection device further includes a solar tracking device 4 . It is mainly used to track sunlight, so that the solar energy collection device is always in the best light-to-heat conversion state. Its specific form can be any existing solar tracking device, as long as it can meet the requirements of tracking sunlight.

In a specific embodiment, as shown in Figure 5, the heat collecting tube 12 is a vacuum tube, including an outer tube 121 and an inner tube 122, the interlayer between the outer tube 121 and the inner tube 122 is a vacuum, and the inner tube 122 carries an energy absorbing medium. The feed pipe 123 and the discharge pipe 124 pass through the outer pipe 121 and the inner pipe 122 in turn respectively, and reach the inside of the inner pipe 122 . Wherein the angle between the feed pipe 123 and the discharge pipe 124 is 0°-180°, which is 0° in this embodiment. Of course, the angle between the feed pipe 123 and the discharge pipe 124 can be selected from 30°, 45°, 60°, 90°, 120°, 135° and 150° according to the actual situation.

Specifically, both the outer tube 121 and the inner tube 122 are light-transmitting tubes.

Preferably, the outer tube 121 is made of glass, PMMA or PC.

Preferably, the inner tube 122 is made of glass, PMMA or PC.

Inspired by the above-mentioned ideal embodiment according to the present invention, through the above-mentioned description content, relevant workers can make various changes and modifications within the scope of not departing from the technical idea of the present invention. The technical scope of the present invention is not limited to the content in the specification, but must be determined according to the scope of the claims.

Claims (7)

1. A rotating parabolic solar collector with two points of focus is characterized in that it comprises: a heat collector, a secondary concentrator and a support, The heat collector includes a primary concentrator and a heat collecting tube, the primary concentrator is a rotating parabolic mirror, and the rotating parabolic mirror has a focal point; The secondary light concentrator is a rotating parabolic reflector or a circular Fresnel reflector, and the secondary light concentrator has a focal point; The heat collecting tube is located between the primary concentrator and the secondary concentrator, and the heat collecting tube is at the focal point of the primary concentrator and the secondary concentrator at the same time, and the heat collecting tube carries an energy absorbing medium; The bracket is used to support the primary concentrator, the secondary concentrator and the heat collecting tube. 2. A double-point-focusing rotating parabolic solar energy collection device as claimed in claim 1, characterized in that: the heat collecting tube is in the shape of an ellipsoid, a sphere or a square. 3. A kind of rotating parabolic solar collector with double point focusing as claimed in claim 1 or 2, characterized in that: the heat collecting tube is a vacuum tube, comprising an outer tube and an inner tube, an outer tube and an inner tube The interlayer between the tubes is a vacuum, and the inner tube carries the energy-absorbing medium. 4. A double-point-focusing rotating parabolic solar collector as claimed in claim 3, characterized in that: both the outer tube and the inner tube are light-transmitting tubes. 5 . The double-point focusing rotating parabolic solar collector as claimed in claim 4 , wherein the material of the outer tube is glass, PMMA or PC. 6 . 6 . A double-point focusing rotating parabolic solar collector as claimed in claim 4 or 5 , wherein the material of the inner tube is glass, PMMA or PC. 7. A double-point-focusing rotating parabolic solar collector as claimed in claim 1, characterized in that it further comprises a solar tracking device.