CN108613413B - A Fresnel dish condenser and its attitude setting method - Google Patents

Abstract

The invention discloses a kind of Fresnel dish-style condensers, sub- mirror including being located at the circular homophony focal axis of center homophony focal axis and a circle or more, homophony focal axis is externally provided with more than one focusing ring, each circle mirror connects a focusing ring, the reflective surface of sub- mirror is in the initial state in the same plane, sub- mirror surrounds more than two concentric turns, the annular array arrangement being centrosymmetric.The invention also discloses a kind of posture setting methods of Fresnel dish-style condenser, and sub- mirror is adjusted in approximately the same plane, posture setting is carried out in bulk to same circle mirror using focusing lever, unloads focusing lever after being provided with.The present invention can greatly reduce the production cost of production high-precision dish-style paraboloidal mirror, realize the adjusting of uniform condensing and focusing ratio and collection area, debugging difficulty and working hour is effectively reduced, and bring industrialized production, installation.

Description

A Fresnel dish condenser and its attitude setting method

technical field

The invention relates to the technical field of solar energy utilization, in particular to a Fresnel dish condenser and a method for setting its attitude.

Background technique

Solar energy utilization technology is in a period of rapid development. In the solar concentrating system, according to the different concentrating methods, it is mainly divided into trough type, tower type and dish type. Compared with the other two methods, the dish type system has a small scale, a large concentration ratio, and high power generation efficiency. The system The structure is simple, the distribution is flexible, the site adaptability is good, it can be modularized to form a hybrid power generation system, no water source is required, and the development potential is large. It is a promising solar thermal utilization device.

The traditional dish concentrating system uses a rotating parabolic concentrator to reflect the concentrated sunlight to the Stirling engine located at the focus of the parabola, heat the medium at the receiver, and drive the Stirling generator to generate electricity. There are generally two production processes for the mirror surface of the rotating parabolic concentrator: the large-curvature reflector is made by the integral method, and the hot bending method is generally used. First, the flat glass is softened at high temperature, and then placed on the processed mold for molding. Then do annealing treatment to make parabolic glass with required radian, and finally bond the glass with silver to form a parabolic reflective surface. However, there are some problems with this method at present. Since glass is an amorphous material, it is difficult to control its forming accuracy when heated. Even if it is placed on a mold after heating at the beginning, springback deformation will occur during the annealing stage. This not only requires high mold precision, but also requires professional hot bending skills. Another method is to use resin to make a high-precision base mold when making a parabolic reflective surface, and then paste a high-reflection film on the surface of the mold to make a parabolic reflective surface. This method is expensive to manufacture, and the weather resistance of the reflective film is poor. It is easy to age after soaking in rain and rotten candles. Both of the above two production processes require special manufacturing equipment, the processing is difficult and the cost is high, and it brings great difficulties to industrialized production, transportation and installation. In addition, the rotating parabolic concentrator used in the traditional dish concentrator is a typical point focusing system, which makes the energy distribution on the focal plane too concentrated, causing the solar heat absorber to withstand high temperature thermal shock for a long time, and the heat absorber Susceptible to high thermal stress and cause heat sink deformation, failure.

Contents of the invention

Purpose of the invention: The technical problem to be solved by the present invention is to provide a Fresnel dish condenser for the deficiencies of the prior art.

The present invention also provides a method for setting the posture of the above-mentioned condenser.

In order to solve the problems of the technologies described above, the technical scheme adopted in the present invention is as follows:

The invention discloses a Fresnel dish condenser, which comprises a main focusing axis located in the center and more than one circle of sub-mirrors surrounding the main focusing axis; more than one focusing ring is arranged outside the main focusing axis; each A circle of sub-mirrors is connected with a focusing ring; in the initial state, the reflective surfaces of the sub-mirrors are all in the same plane, and the sub-mirrors are surrounded by more than two concentric circles, arranged in a centrally symmetrical annular array; the sub-mirrors are plane mirrors.

In the present invention, the sub-mirror is movably connected to the sub-mirror bracket. Each sub-mirror bracket can be connected as a whole, or can be set independently.

In the present invention, the specifications of the sub-mirrors are unified, the shape and size are arbitrary, and can be any one of rectangle, regular hexagon, trapezoid or sector, and the adjustment of the light-gathering ratio and the light-gathering area can be realized by changing the number and size of the sub-mirrors .

In the present invention, detachable focus levers that are connected to the same focus ring are respectively provided on the backs of the sub-mirrors in the same circle.

In the present invention, the relative position between the focus lever and the sub-mirror is fixed and there is no relative translation and rotation displacement. One end of the focus lever of all the sub-mirrors in the same circle is connected to the back of the sub-mirror, and the other end is connected to the main adjuster. Focus ring for the focal axis.

In the present invention, the focus lever and the focus ring are flexibly connected, the focus lever can rotate relative to the radial direction of the focus ring, the focus ring and the main focus axis are flexibly connected, and the focus ring can rotate along the main focus axis. The focus axis moves up and down; when the focus ring moves up and down along the main focus axis, the angle between the focus lever and the main focus axis can be changed accordingly, driving the inclination angle of the circle mirror along the radial direction to change, realizing the alignment of the same circle mirror The batch pose setting for .

In the present invention, a connecting joint is provided between the focusing lever and the sub-mirror.

In the present invention, after the posture setting process is finished, only the connecting joints between the focusing ring and the main focusing axis, the sub-mirror and the sub-mirror bracket are locked, and the focusing rod can be removed to reduce the complexity of the mechanism.

The invention also discloses a method for setting the attitude of a Fresnel dish condenser, which includes the following steps:

Step (a), leveling all the sub-mirrors of the condenser to the initial state, that is, all the sub-mirrors are in the same plane;

Step (b), gradually set the attitude of the sub-mirror from the outer circle to the inner circle, set the attitude of the outermost circle mirror, and move the focusing ring corresponding to the outermost circle mirror downward along the main focusing axis to drive the outermost The circle mirror is inclined radially inward. At this time, the circle mirror is a circular or hollow ring-shaped light spot on the heat-absorbing surface. Keep moving the focus ring downward, and the reflected light spot of the circle mirror will gradually shrink and continue to move downward. Adjust the focus ring until the radius of the reflected light spot of the circle mirror reaches the minimum; adjust the focus ring corresponding to each circle mirror from outside to inside, so that the size and position of the light spot reflected by the circle mirror is the same as that of the outermost circle mirror;

Step (c), determine the position of the focus ring of each circle mirror, after the optical device is checked and correct, lock the connection joints between the focus ring and the main focus axis, the sub-mirror and the sub-mirror bracket one by one, so that each circle mirror The inward inclination angle is fixed, the posture setting action is completed, and the focus levers of each circle mirror are removed.

The present invention also discloses a Fresnel dish condenser, which includes a group of sub-mirrors, the group of sub-mirrors is distributed in an annular shape symmetrical to the center of more than two circles, and each circle has more than three sub-mirrors, the sub-mirrors are plane mirrors, and All sub-mirrors focus to one position.

Beneficial effect:

1. It is composed of low-cost commercial small plane mirrors, which solves the problem of manufacturing high-precision parabolic mirrors for traditional parabolic dish condensers, and greatly reduces the manufacturing cost of condensers.

2. By changing the number and size of the sub-mirrors, it is easier to adjust the light-gathering ratio and the light-gathering area.

3. During the installation process of the condenser, it is only necessary to precisely adjust all the sub-mirrors on the same plane at the beginning, and the attitude of the same circle mirror can be set in batches, which reduces the difficulty of installation and debugging, saves the man-hours of installation and debugging, and significantly reduces the installation of the condenser Commissioning costs.

4. Through the structural design of the present invention, the energy distribution on the focal plane of the condenser is more uniform, and it is easy to achieve uniform light concentration, which prolongs the service life of the receiver.

Description of drawings

The advantages of the above and/or other aspects of the present invention will become clearer as the present invention will be further described in detail in conjunction with the accompanying drawings and specific embodiments.

Fig. 1 is embodiment 1 concentrating mirror mirror arrangement scheme figure;

Fig. 2 is the structural diagram of embodiment 1 condenser mirror-circle mirror;

Fig. 3 is the schematic diagram of the focal spot on the heat absorbing surface after the attitude setting of the condenser in embodiment 1;

Fig. 4 is a radial distribution diagram of energy flux density on the focal plane of the condenser lens in embodiment 1.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings.

Example 1:

As shown in Fig. 1, the present embodiment discloses a Fresnel dish condenser, comprising a group of sub-mirrors 1, the group of sub-mirrors 1 is seven centrally symmetrical annular distribution circles, and each circle of mirrors is more than three, The sub-mirrors are plane mirrors, and all sub-mirrors focus to one position. The specifications of the sub-mirrors are uniform, using 204 square sub-mirrors with a side length of 150mm, of which, there are 10 sub-mirrors in the first circle with a radius of 320mm, 16 sub-mirrors in the second circle with a radius of 490mm, and 23 sub-mirrors in the third circle There are 29 sub-mirrors in the fourth circle with a radius of 830mm, 36 sub-mirrors in the fifth circle with a radius of 1000mm, 42 sub-mirrors in the sixth circle with a radius of 1170mm, and 48 sub-mirrors in the seventh circle. The radius is 1340mm.

Example 2

This embodiment is made up of a plurality of planar sub-mirrors 1, and the reflective surfaces of all sub-mirrors are all in the same plane in the initial state, and the sub-mirrors are surrounded by a plurality of concentric circles, arranged in a centrally symmetrical ring array, and the condenser mirror is composed of 7 circles of sub-mirrors. Composition, sub-mirror specifications are uniform, using 204 square sub-mirrors with a side length of 150mm, of which, the first circle has 10 sub-mirrors with a radius of 320mm, the second circle has 16 sub-mirrors with a radius of 490mm, and the third circle has a total of 23 sub-mirrors with a radius of 660mm, the fourth circle has 29 sub-mirrors with a radius of 830mm, the fifth circle has 36 sub-mirrors with a radius of 1000mm, the sixth circle has 42 sub-mirrors with a radius of 1170mm, and the seventh circle has 48 sub-mirrors mirror with a radius of 1340mm.

As in Fig. 2, the structural diagram of a circle mirror of the present embodiment condenser, in the same circle mirror, each mirror 1 is fixedly connected with a focusing rod 2 at the back, and the mirror is movably connected to the mirror bracket 5. When the condenser is in the normal state of chasing the sun, the condenser can reflect the direct solar radiation to the heat-absorbing surface, and the coincidence degree of the center of the light spot and the center of the heat-absorbing surface meets the accuracy requirements. When the condenser is in the initial state, all the sub-mirrors are in the same plane accurately enough, and when the posture is set, the focus ring 4 of a circle is moved downward along the main focus axis 3, thereby driving the mirror surface of the circle radially inward Tilt, at this time, the condenser mirror is a larger circular or hollow ring-shaped spot on the heat-absorbing surface. Keep moving the focus ring 4 downwards, and the reflected light spot of the circle mirror will gradually shrink. Focus ring 4, until the radius of the reflected light spot of the circle mirror reaches the requirement, at this time the light spot of the circle mirror becomes a much smaller circle spot, and the attitude setting process of the circle mirror ends. When setting the attitude, first adjust the outermost circle mirror to make the reflection spot radius of the outermost circle mirror reach the minimum, and then set the attitude of the other circle mirrors from outside to inside. When the inner circle mirror is in attitude setting, the focus ring moves It is sufficient to make the reflected light spot of the circle mirror the same size as the light spot of the outermost circle mirror.

FIG. 3 is a schematic diagram of the focal spot on the heat absorbing surface after the attitude setting of the condenser in this embodiment is completed. It can be seen that the focal spot on the heat absorbing surface is approximately a circular spot with a radius of 122 mm after the attitude setting is completed.

As shown in Fig. 4 , the distribution diagram of the energy flux density along the radial direction on the focal plane of the condenser of the present embodiment, the horizontal axis is the radial length, and the vertical axis is the energy flux density value. It can be seen that the energy flux density distribution on the focal plane is relatively uniform and the distribution area is large, and most of the energy is distributed within the radius of 112mm. Compared with the traditional point-focused parabolic dish condenser, the life of the heat sink is prolonged.

During the actual operation of the condenser, the reflected light spots of multiple small plane mirrors overlap together, so it is difficult to judge whether a certain circle mirror has completed the focus adjustment through the shape of the light spot. The radial rotation angle of the focus ring, according to the angle and the length of the focus rod, can calculate the distance that the focus ring corresponding to the circle mirror moves up and down on the main focus axis, so that the focusing process of the condenser is more accurate.

Example 3

In this embodiment, the shape of the sub-mirror 1 is fan-shaped, and each circle of sub-mirrors is also arranged in a centrally symmetrical annular array. unanimous.

The present invention provides a kind of train of thought and method of Fresnel dish condenser and attitude setting thereof, and there are many methods and ways to realize this technical scheme specifically, the above-mentioned is only the preferred embodiment of the present invention, it should be pointed out that for this technology Those of ordinary skill in the art can make some improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention. All components that are not specified in this embodiment can be realized by existing technologies.

Claims (8)

1. a kind of attitude setting method of Fresnel dish condenser, it is characterized in that, The Fresnel dish condenser includes a main focusing axis (3) located in the center and a sub-mirror (1) surrounding the main focusing axis (3) for more than one circle; the main focusing axis (3) is provided with a The above focus ring (4); each circle mirror (1) is connected to a focus ring (4); in the initial state, the reflective surfaces of the sub-mirror (1) are all in the same plane; the sub-mirror (1) Surrounded by more than two concentric circles, arranged in a centrally symmetrical annular array; the sub-mirror (1) is a plane mirror; The attitude setting method of the Fresnel dish condenser comprises the steps: Step (a), leveling all sub-mirrors (1) of the condenser to the initial state, that is, all sub-mirrors (1) are in the same plane; Step (b), gradually set the attitude of the sub-mirror from the outer circle to the inner circle; the attitude setting includes adjusting the outermost circle mirror, and adjusting the focus ring corresponding to the outermost circle mirror along the main focusing axis (3 ) moves downward, driving the mirror surface of the circle mirror to incline radially inward. At this time, the circle mirror is a circular or hollow ring-shaped spot on the heat-absorbing surface. Keep moving the focus ring downward, and the reflection of the circle mirror The light spot gradually shrinks, and continue to move the focus ring downward until the radius of the reflected light spot of the circle mirror reaches the minimum; adjust the focus ring corresponding to each circle mirror from outside to inside, so that the reflection spot of the circle mirror is the same as the outermost circle mirror. The spot size and position are the same, and the attitude setting process is over; Step (c), determine the position of the focusing ring of each circle mirror, and after checking, lock the focusing ring (4) and the main focusing axis (3), the sub-mirror (1) and the sub-mirror bracket (5) one by one. ) to fix the inward inclination angle of each circle mirror. After the attitude setting action is completed, remove the focus lever (2) of each circle mirror. 2 . The attitude setting method of a Fresnel dish condenser according to claim 1 , wherein the sub-mirror ( 1 ) is movably connected to the sub-mirror bracket ( 5 ). 3 . The attitude setting method of a Fresnel dish condenser according to claim 1 , wherein the sub-mirror ( 1 ) is any one of a rectangle, a regular hexagon, a trapezoid or a sector. 4 . 4. The attitude setting method of a kind of Fresnel dish condenser according to claim 2, characterized in that, the backs of the sub-mirrors (1) in the same circle are respectively provided with joints connected to the same focus ring ( 4) The detachable focus lever (2). 5. The attitude setting method of a Fresnel dish condenser according to claim 4, characterized in that the relative position between the focusing lever (2) and the sub-mirror (1) is fixed and no relative translation occurs and rotation displacement, one end of the focusing lever (2) of all the sub-mirrors in the same circle is connected to the back of the sub-mirror (1), and the other end is connected to the focusing ring (4) of the main focusing axis (3). 6. The attitude setting method of a Fresnel dish condenser according to claim 5, characterized in that the focus lever (2) and the focus ring (4) are flexibly connected, and the focus lever ( 2) It can rotate relative to the radial direction of the focus ring (4), the focus ring (4) is connected to the main focus axis (3), and the focus ring (4) can move along the main focus axis (3) Moving up and down; When the focus ring (4) moves up and down along the main focus axis (3), the focus lever (2) can change the angle with the main focus axis (3), driving the circle mirror to move radially The inclination angle is changed to achieve batch attitude setting for mirrors in the same circle. 7 . The attitude setting method of a Fresnel dish condenser according to claim 6 , wherein a connection joint is provided between the focusing rod ( 2 ) and the sub-mirror ( 1 ). 8. The attitude setting method of a Fresnel dish condenser according to claim 7, characterized in that the focus lever (2) is used to lock the focus ring (4) and the main focus axis (3) Disassemble the connecting joint between the sub-mirror (1) and the sub-mirror bracket (5).