CN104567029A - Two-shaft fixed-point tracking device of disc type solar thermal collector - Google Patents

Abstract

The invention relates to a solar tracking device, in particular to an active two-axis fixed-point tracking device for a dish solar heat collector. The device includes: 1-mirror; 2-circular guide rail; 3-first tracking axis; 4-support. The first tracking axis (3) is parallel to the earth axis, and the circular guide rail (2) rotates around the first tracking axis together with the reflector (1) to track the change of light direction caused by the rotation of the earth. The reflector (1) slides on the circular guide rail (2) to adjust the pitch angle, that is, it rotates around the second tracking axis, and tracks the change of light direction caused by the revolution of the earth. The two tracking axes are perpendicular and intersect at a point where the focal point of the mirror coincides. During the tracking process, the spatial position of this point is always fixed, which realizes the fixed-point focusing function of the collector. The two tracking axes correspond to tracking the rotation and revolution of the earth respectively, and are independent of each other, which can facilitate active tracking control.

Description

A two-axis fixed-point tracking device for dish solar collectors

technical field

The invention relates to a tracking device for solar heat collectors, in particular to an active two-axis fixed-point tracking device for dish solar heat collectors. According to the International Patent Classification (IPC), it belongs to the "Mechanical Engineering; Lighting; Heating; Weapons; Explosives" department, the "Lighting; "Heat generation and utilization" subcategory, "Solar collectors with heater supports" group technical field (F24J2/02-38, G06T15/06). the

Background technique

According to the characteristics of the reflector, solar collectors can be divided into trough type, Fresnel type, dish type and tower type. At present, trough, Fresnel and tower solar thermal power generation technologies are relatively mature and have entered the commercial demonstration stage of large-scale construction. Dish-type solar collectors use butterfly-shaped rotating parabolic reflectors to focus sunlight into one point, which is the collection method with the highest heat collection ratio. However, due to immature technologies such as tracking systems, the cost of large-scale construction is too high at present, and further research and development is needed . the

The existing tracking devices of dish solar collectors basically use the radar tracking principle: one rotating shaft is perpendicular to the ground to adjust the direction, and the other rotating shaft adjusts the pitch angle between the reflector and the ground. Although this tracking mechanism can achieve precise tracking of the sun's rays, the spatial position of the focus point is not fixed, which makes the receiver must move together with the reflector. Secondly, this tracking system does not achieve a reasonable decomposition of the tracking vector, and both rotation axes need to be adjusted in real time during the tracking process. In addition, if this kind of tracking system is active, the control program is more complicated, so basically passive tracking is used, and sensors are used to determine the direction of the sun's rays. The above characteristics increase the manufacturing and operating costs of the mechanism, hindering its large-scale application. the

Contents of the invention

Aiming at the deficiencies in the existing tracking system of the dish solar collector, the invention provides an active two-axis fixed-point tracking device for the dish solar collector. First of all, this tracking device makes the spatial position of the focal point of the mirror fixed during operation. This can facilitate the design and installation of the collector, reduce operating costs, and create conditions for large-scale construction. Secondly, the two tracking axes of the tracking system respectively track the light direction changes caused by the earth's rotation and revolution, which greatly reduces the difficulty of active tracking and can realize two-axis independent tracking control. the

In order to solve the above technical problems, the technical solution adopted by the patent of the present invention is: the system uses two vertically intersecting rotating shafts to trace the sun's rays, the first rotating shaft is parallel to the earth's axis, and the tracking speed is equal to and opposite to the rotation of the earth. Tracks changes in light caused by the Earth's rotation. The second rotating shaft is fixed on the first rotating shaft, and its rotation is used to adjust the pitch angle of the reflector and track the change of the sun's light caused by the revolution of the earth. The two rotating shafts intersect at one point, and the focus of the reflector is designed on this point. During the tracking process, the position of the intersection of the two axes is always fixed, and the spatial position of the focal point of the mirror will not change. Because the two tracking axes track the rotation and revolution of the earth respectively, they can be controlled independently and realize active tracking conveniently. the

Aiming at the problem that the wind load is more destructive to large dish solar collectors, the design idea of parallel mechanism is used for reference in the specific structure, and a large-diameter ring gear is used to drive the mechanism to run. the

The beneficial effect of the present invention has three points:

1) It can ensure that the spatial position of the focal point of the dish solar collector remains unchanged, so as to facilitate the design and installation of the receiver and related components. the

2) Two-axis independent tracking control can be realized to reduce the difficulty of control. the

3) The rotation around the tracking axis is driven by the ring gear whose center coincides with the axis. the

Advantages 1 and 2 can reduce the manufacturing and operating costs of the collector, and advantage 3 can increase the strength of the structure, enhance the ability to resist wind load, and increase the service life. the

Description of drawings

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

Figure 1 is a schematic diagram of the two-axis fixed-point tracking system. the

Among them: 1-reflector; 2-circular guide rail; 3-first tracking axis; 4-support. the

The first tracking axis (3) is parallel to the earth's axis, and the inclination angle to the ground is equal to the local latitude. The circular orbit (2) rotates around the first tracking axis together with the reflector to track the change of light direction caused by the rotation of the earth. The reflector (1) slides on a circular track, and the center of the circular track corresponds to the second tracking axis (perpendicular to the viewing plane). The sliding of the reflector on the track is equivalent to rotating around the second tracking axis, which can be adjusted The pitch angle of the mirror, which tracks changes in the direction of light rays caused by the Earth's revolution. The two tracking axes intersect perpendicularly at a point, and the position of this point remains unchanged during the tracking process. If the shape of the mirror is reasonable so that its focal point coincides with this point, the spatial position of the focal point of the mirror will also remain unchanged. the

Figure 2 is a front view of the specific structure, and Figure 3 is an axonometric view of the specific structure. the

Among them: 1-mirror; 2-mirror support; 3-circular guide rail; 4-ring gear for pitch angle adjustment; 5-drive gear for pitch angle adjustment; 6-drive motor A; 7- Drive gear for direction adjustment; 8-drive motor B; 9-ring gear for direction adjustment; 10-rear support; 11-front support. the

Detailed ways

As shown in Figures 2 and 3, the reflector (1) is fixed on a reflector support (2), and the reflector support is mounted on a circular guide rail (3). The reflector support is fixed together with the pitch angle adjustment ring gear (4). The ring gear (4) meshes with the drive gear (5) and slides on the circular guide rail under the push of the drive motor A (6) to adjust the pitch angle of the mirror. the

The circular guide rail is mounted on the front and rear supports (10, 11) by the shafts at both ends, and the direction of the shaft and the inclination angle of the ground are equal to the local latitude and parallel to the axis of rotation of the earth. The circular guide rail is fixed together with the ring gear (9) used for direction adjustment, the ring gear (9) meshes with the drive gear (7), and is driven by the drive motor B (8) to rotate around the axis, tracking due to the rotation of the earth Changes in the direction of the sun's rays. the

Drive motor A (6) is fixed together with circular guide rail (3). the

Drive motor B (8) is contained on the back support (10). the

The track axis of the circular guide rail (3) intersects with the rotation axis of the guide rail at one point, and the focus of the reflector (1) is also designed at this point, so as to ensure that the spatial position of the focus remains unchanged during the tracking process. the

Claims (4)

1. the diaxon fixed point tracking device for disc type solar energy heat collector, by two rotating shafts intersected vertically, sunray is followed the trail of, two rotating shafts meet at a bit, and by the multifocal design of speculum in this, realize the locus of reflector focal point in tracing process constant.

2. diaxon fixed point tracking device according to claim 1, first shaft parallel in the earth's axis, for following the trail of the light change caused because of earth rotation.Second rotating shaft is fixed in first rotating shaft, and it rotates the angle of pitch for adjusting speculum.Follow the trail of rotation and the revolution that axle follows the trail of the earth respectively, independently can carry out active tracking control for two.

3., according to claim 1 and disc type solar energy heat collector diaxon fixed point tracking device according to claim 2, slide to adjust the angle of pitch on circuit orbit by speculum, complete the tracking task of second axis.

4., according to claim 1 and disc type solar energy heat collector diaxon fixed point tracking device according to claim 2, promote around the two tracking centers that rotate through of axle and the gear ring of dead in line, to increase the intensity of structure.