CN114608207A - Disc type solar tracking device based on 3-RPS parallel mechanism - Google Patents

Abstract

The invention relates to a disc type solar tracking device based on a 3-RPS parallel mechanism, and belongs to the technical field of new energy. The tracking device comprises a receiver, a support frame, a rotating paraboloid reflector, a 3-RPS parallel mechanism, a rack and a foundation. The rotating paraboloid reflector is divided into an inner layer and an outer layer, and each layer of the mirror surface is composed of a plurality of identical mirror surfaces. The single lens is arranged on a moving platform of the independent 3-RPS parallel mechanism, the fixed platform is fixed at the upper end of the frame, and the frame is fixedly arranged at a specific position of a foundation through a positioning mechanism and a fastener or in a welding mode. Three stepping motors drive linear expansion devices respectively driving 3 branched chains, and all 3-RPS parallel mechanisms complete cooperative tracking through a tracking control system on the premise of keeping the integral shape of the mirror surface unchanged. The device has compact structure, flexible installation, strong stability and low construction cost, and is suitable for large-scale solar power stations with automation and self-adaptive control.

Description

A Dish Solar Tracking Device Based on 3-RPS Parallel Mechanism

technical field

The invention relates to the technical field of new energy, in particular to a dish solar tracking device based on a 3-RPS parallel mechanism.

Background technique

With the advent of the revolutionary wave of new energy development, solar energy, as a renewable new energy source, has become an alternative energy source that human beings urgently need to develop due to its advantages such as unlimited storage, universality and economy. Solar thermal power generation technology and photovoltaic power generation technology are the two most common ways to rationally utilize solar energy. Compared with photovoltaic power generation, the solar thermal power generation system has the advantages of high efficiency, low cost and mature technology. In terms of thermal energy storage, the system adopts a simple method and costs less. In the absence of light, the power station can still be sent to the power station. Continuous power supply. The power output is stable, and it is easy to form a hybrid power generation with fossil fuels, which has become a main research direction of the current solar energy development and utilization.

The dish solar thermal power generation system is the solar thermal power generation system with the highest thermal efficiency and optical efficiency today. It consists of a dish concentrator and a solar tracking mechanism. The concentrator is installed on the sun tracking mechanism to reflect sunlight to the receiver installed on the focal point. The use of the sun tracking mechanism can make the condenser continuously adjust its attitude to achieve the whole day. For the purpose of aligning the sun's rays to improve the efficiency of solar power generation, the sun tracking mechanism is an important part of the dish solar thermal power generation system.

Based on the mechanical characteristics of the tracking mechanism, solar tracking mechanisms can be divided into single-axis tracking and dual-axis tracking. The single-axis tracking mechanism has a simple structure, but it can only track the position of the sun in one direction, and cannot always make the axis of the concentrator parallel to the sun's rays. The dual-axis tracking mechanism can achieve 2-direction tracking, so that the concentrator is always parallel to the sun's rays at any time in any season, so the dual-axis tracking mechanism has been widely used in solar power generation systems. However, the dual-axis tracking mechanism is usually designed based on the tandem mechanism. Generally, the tandem dual-axis tracking mechanism consists of a vertical rotating shaft and a horizontal rotating shaft. The vertical rotating shaft is fixed on the ground to support the load of the entire tracking mechanism and drive the tracking mechanism to complete the sun azimuth. For angle tracking, the horizontal shaft is vertically installed on the top of the vertical shaft to achieve the tracking of the sun's altitude angle. Although this tracking mechanism is simple in principle, its stiffness is low. In addition, due to the large size and weight of the large-scale solar concentrator mechanism, and the influence of external loads such as wind and sand during field work, the normal line of the condensing mirror often shifts. If the traditional altitude and azimuth tracking are used, it cannot be automatically compensated. The tracking error caused by the normal offset, so that the tracking accuracy cannot meet the design requirements.

SUMMARY OF THE INVENTION

In order to solve the above technical problems, the purpose of the present invention is to propose a dish solar tracking device based on 3-RPS parallel mechanism with high rigidity and good stability. The belt drive controls the rotation of the ball screw, thereby controlling the length of the branch chain, further improving the tracking accuracy.

The technical scheme adopted in the present invention is: a dish solar tracking device based on a 3-RPS parallel mechanism, comprising a receiver, a support frame, a rotating parabolic mirror, a 3-RPS parallel mechanism, a rack and a foundation. The rotating parabolic reflector is divided into inner and outer layers, and each layer is composed of the same multiple mirrors. The 3-RPS parallel tracking mechanism is divided into an inner 3-RPS parallel mechanism and an outer 3-RPS parallel mechanism, including a moving platform, a fixed platform, and three identical RPS branch chains (R-rotating pair, P moving pair, S -Ball pair), a single mirror is fixed on the moving platform of a separate 3-RPS parallel mechanism, each RPS branch chain consists of a ball pair S connecting the moving platform and the linear expansion device, the expansion device P pair, and the linear expansion device. It is composed of the rotating pair R of the fixed platform. The RPS branch chain structure of the inner layer and the outer layer is the same, but the extension stroke of the RPS branch chain of the outer layer is longer than that of the inner layer. The inner moving platform and the inner fixed platform of the 3-RPS parallel mechanism of the inner layer are respectively For similar equilateral triangles, the position of the subcenter of rotation forms an equilateral triangle Δabc. The external moving platform and the external fixed platform of the outer layer 3-RPS parallel mechanism are similar isosceles triangles, and the rotation subcenter at the position of the external fixed platform forms an isosceles triangle ΔABC similar in shape to the external moving platform.

In the above-mentioned dish solar tracking device based on a 3-RPS parallel mechanism, the rotating parabolic reflector is divided into two layers: the inner and outer layers, the paraboloid equations of the inner and outer mirrors are the same equation, and the structure and size of the mirrors on the same layer are exactly the same. The block mirrors are fixed on the moving platform of a separate 3-RPS parallel mechanism to form a complete rotating parabolic mirror.

In the above-mentioned dish solar tracking device based on the 3-RPS parallel mechanism, the inner moving platform and the inner fixed platform of the inner 3-RPS parallel mechanism are both equilateral triangles, and the RPS branch chain is connected to the vertices of the equilateral triangle through the rotating pair, The rotation axis is coplanar, not only parallel to the opposite side of the installed vertex, but also parallel to the plane of the inner fixed platform; the outer moving platform and the outer fixed platform of the outer 3-RPS parallel mechanism are isosceles triangles, and the two isosceles triangles are similar , the RPS branch is connected to the vertex of the isosceles triangle through the rotation pair, and the axis of the rotation pair is coplanar, which is not only perpendicular to the line connecting the center and the vertex of the circumcircle of the isosceles triangle ΔABC, but also parallel to the outer fixed platform plane.

In the above-mentioned dish solar tracking device based on 3-RPS parallel mechanism, the linear telescopic device driving device is composed of a driving stepper motor, a synchronous pulley, a screw nut pair, a sliding rod, and a sliding piston, and the output shaft of the driving stepper motor is synchronously driven. The belt drive is connected with the lead screw.

In the above-mentioned 3-RPS parallel mechanism-based dish solar tracking device, the fixed platform is fixedly connected to the frame, and the bracket is fixedly installed at a specific position of the foundation by means of a positioning mechanism and fasteners or welding.

Compared with the prior art, the beneficial effects of the present invention are:

1. From the structural point of view, the present invention has the advantages of compact structure and flexible installation of the traditional single-axis tracking mechanism, and is almost not limited by the construction site, and the construction cost is relatively low; The RPS branch chains are jointly borne, each branch chain is independent of each other, and there is an appropriate gap between the single mirror surfaces to reduce the influence of wind load, so it has the advantages of high rigidity, strong stability, and few transmission parts. It is improved from the traditional dish condenser, and the existing rotating parabolic reflector can be used, and it is suitable for both the hyperboloid reflector and the elliptical reflector, reducing the design, manufacture, installation and debugging of the mirror surface. cost.

2. From the control point of view, the branch chain of the present invention is provided with a synchronous belt, and the output shaft of the driving stepper motor is connected to the lead screw through the synchronous belt, which can precisely control the rotation angle of the lead screw, which is suitable for program control; a single mirror has a separate The controller can automatically compensate the tracking error if the normal deviation occurs, so as to achieve the purpose of adaptive control.

Description of drawings

FIG. 1 is a structural diagram of the present invention.

FIG. 2 is a structural diagram of the inner layer single tracking device of the present invention.

FIG. 3 is a structural diagram of a single disc tracking device after the inner layer of the present invention has been removed from the mirror.

FIG. 4 is a structural diagram of the outer layer single tracking device of the present invention.

FIG. 5 is a structural diagram of a single tracking device after the outer layer of the present invention is removed from the mirror.

FIG. 6 is a top view of the installation of the internal fixed platform and the pin seat of the present invention.

FIG. 7 is a top view of the installation of the external fixed platform and the pin seat of the present invention.

Figure 8 is a structural diagram of the RPS branch of the present invention.

Figure 9 is a diagram of the internal structure of the RPS branch of the present invention.

1-receiver, 2-support frame, 3-rotating parabolic mirror, 4-first hinge, 5-3-RPS parallel mechanism, 6-frame, 7-foundation, 8-inner mirror, 9-internal movement Platform, 10—Inner RPS branch chain, 11—Internal fixed platform, 12—Ball hinge, 13—Inner linear expansion device, 14—Rotation pair, 15—Outer mirror surface, 16—External moving platform, 17—Outer RPS Branch chain, 18-external fixed platform, 19-outer layer linear expansion device, 20-ball socket, 21-double ear bracket, 22-movable cover plate, 23-rail box, 24-drive stepping motor, 25-coupling Gear box, 26 - pulley transmission box, 27 - rotating auxiliary hinge ear, 28 - sliding rod, 29 - sliding piston, 30 - ball nut, 31 - ball screw, 32 - angular contact bearing, 33 - synchronous belt drive.

Detailed ways

The dish solar tracking device based on the 3-RPS parallel mechanism proposed by the present invention is described as follows in conjunction with the accompanying drawings:

As shown in FIG. 1 , the present invention includes a receiver 1 , a support frame 2 , a rotating parabolic mirror 3 , a 3-RPS parallel tracking mechanism 4 , a frame 5 , and a foundation 6 . The four outer mirror surfaces 15 of the rotating parabolic reflector 3 are provided with the hinge seat of the first hinge 4, the axis of the pin hole of the hinge seat is parallel to the ground, and the receiver 1 is provided at the position corresponding to the hinge seat of the rotating parabolic reflector. The hinge ear, the support frame fixes the receiver on the focus of the rotating parabolic mirror 3 through the first hinge 4; the shape and size of the upper platform of the frame 6 is completely consistent with the fixed platform of the 3-RPS parallel tracking mechanism 5 that is fixedly connected , fix the 3-RPS parallel tracking mechanism 5 on the upper platform of the frame 6 by welding or bolts; the shape of the lower platform of the frame 6 is similar to the shape of the upper platform, the size is larger than that of the lower platform, and the lower platform is tightened by the positioning mechanism Firmware or welding is fixedly installed at a specific position of the foundation 7 .

As shown in Figures 1, 2, and 4, the rotating parabolic reflector 3 is divided into an inner mirror surface 8 and an outer mirror surface 15, each mirror surface is composed of the same multiple mirror surfaces, and the paraboloid equations of the inner and outer mirror surfaces are the same Equation, the mirrors of the same layer have the same structural form and size, and together form a complete rotating parabolic mirror 3, the single mirror is fixed on the moving platforms 9 and 18 of the separate 3-RPS parallel tracking mechanism, and the moving platforms 9 and 18. 18 produces the same movement.

As shown in Figures 3, 5, 6, and 7, the 3-RPS parallel tracking mechanism includes an inner 3-RPS parallel mechanism, an outer 3-RPS parallel mechanism, and the inner 3-RPS parallel mechanism consists of an inner moving platform 9 , Three sets of identical inner layer RPS branch chain 10 and internal fixed platform 11 are composed, of which the internal moving platform 9 and the internal fixed platform 11 are equilateral triangles, and the hinge seat of the rotating pair 14 is fixed on the internal fixed platform by bolts, and its center is fixed on the internal fixed platform. The position of the platform forms an equilateral triangle, and the axes of the pin holes of the second hinge 29 are coplanar, not only parallel to the opposite side of the installed vertex, but also parallel to the plane of the inner fixed platform 9; because the size of the outer mirror surface is different from the inner mirror surface, Therefore, the inner and outer 3-RPS parallel mechanisms are parallel mechanisms with different configurations, the outer moving platform 16 and the outer fixed platform 18 are similar isosceles triangles, and the center of the rotating pair 14 is at the position of the outer fixed platform to form an isosceles triangle ΔABC , the outer RPS branch 17 is connected to the vertex of the isosceles triangle ΔABC through the rotation pair 14, and the rotation pair axis is coplanar, which is not only perpendicular to the line connecting the center and vertex of the circumcircle of the isosceles triangle ΔABC, but also parallel to the outer Platform 16 flat.

As can be seen in Figure 8, the inner RPS branch 9 and the outer RPS branch 17 are composed of a ball hinge 12, linear telescopic devices 13 and 19, a driving stepper motor 24, and a rotating auxiliary hinge lug 27. The ball hinge 12 passes through the double lugs. The bracket 21 is installed on the movable cover plate 22 of the linear telescopic device, and the center of the ball head is collinear with the center of the pin holes at both ends of the double-ear bracket 21; Based on the theory of rigid body kinematics, in order to keep the entire mirror surface as a paraboloid and the gap between the mirror surfaces does not change during the tracking process of the rotating parabolic reflector 3, the expansion and contraction distance of the outer RPS branch 17 is larger than that of the inner RPS branch 10 That is, the stroke of the inner layer linear expansion and contraction device 13 is longer than that of the outer layer linear expansion and contraction device 19 . The motor control system controls the driving stepper motor 24 to drive the RPS branch chain according to the tracking requirements program, thereby changing the length of the linear telescopic devices 13 and 19 to drive the normal line of the rotating parabolic reflector 3 to be parallel to the sun's rays, so that the sun's rays are focused on the receiving device 1.

9 is the internal mechanism diagram of the linear telescopic device, the drive stepping motor 24 and the ball screw 31 transmit motion through the synchronous belt drive 33, the ball nut 30 is built into the sliding piston 29, and the ball nut 30 and the ball screw With the cooperation of 31, using the advantages of accurate transmission ratio and high transmission precision of the synchronous belt drive 33, the rotary motion of the motor 24 is converted into the linear motion of the sliding piston 29 in the guide rail box 23, and then the length of the branch chain is changed; because the sliding piston 29 The moving range of the ball screw 31 is large, and the length of the ball screw 31 is long. One end of the screw is fixed on the pulley transmission box 26, and the other end is supported by the ball nut 30, the sliding piston 29, the sliding rod 28, and the movable cover 22. The way to make up the sliding part is installed. In the actual tracking process, the ball screw 31 needs to bear axial force and radial force at the same time, so a pair of angular contact ball bearings 32 are installed at both ends of the ball screw 31; It is fixedly connected with the sliding rod 28 by screws; because the sliding rod 28 is responsible for supporting the 3-RPS parallel movable platform and the sliding piston 29, and bears the large weight of the mirror and the movable platform, the force mainly acts in the radial direction, so three sliding rods are used. Rod load to increase the stiffness of the RPS branch.

Claims (5)

1. a dish type solar energy tracking device based on 3-RPS parallel mechanism, it is characterized in that this tracking device comprises receiver, support frame, rotating parabolic mirror, 3-RPS parallel mechanism, rack, foundation; Described rotating parabolic reflection The mirror is divided into inner and outer layers, each layer is composed of the same multiple lenses; the 3-RPS parallel tracking mechanism is divided into an inner layer 3-RPS parallel mechanism and an outer layer 3-RPS parallel mechanism, including a moving platform, a fixed platform, Three identical RPS branch chains (R-rotating pair, P-moving pair, S-ball pair), a single mirror is fixed on the moving platform of a separate 3-RPS parallel mechanism, each RPS branch is connected by connecting the moving platform and The ball pair S of the linear expansion device, the expansion device P pair, and the rotating pair R connecting the linear expansion device and the fixed platform are composed. The RPS branch chain structure of the inner layer and the outer layer is the same, but the expansion stroke of the outer layer RPS branch chain is longer than that of the inner layer. , the inner moving platform and the inner fixed platform of the inner 3-RPS parallel mechanism are similar equilateral triangles, respectively, and the position of the inner fixed platform of the rotation sub-center forms an equilateral triangle Δabc; the outer moving platform of the outer 3-RPS parallel mechanism The platform and the external fixed platform are similar isosceles triangles, and the position of the rotation sub-center at the external fixed platform forms an isosceles triangle ΔABC similar to the external moving platform. 2. The dish solar tracking device based on a 3-RPS parallel mechanism according to claim 1, wherein the rotating parabolic reflector is divided into inner and outer layers, and the paraboloid equations of the inner and outer two layers of mirrors are the same equation, and the same The structure and size of the layer mirror are exactly the same, and the single mirror is fixed on the moving platform of a separate 3-RPS parallel mechanism to form a complete rotating parabolic mirror. 3. dish type solar tracking device based on 3-RPS parallel mechanism according to claim 1, is characterized in that: the inner moving platform and the inner fixed platform of described inner layer 3-RPS parallel mechanism are equilateral triangle, RPS branch chain It is connected to the vertex of the equilateral triangle through the rotating pair, and the axis of the rotating pair is coplanar, which is parallel to the opposite side of the installed vertex and parallel to the plane of the inner fixed platform; The fixed platforms are all isosceles triangles, the two isosceles triangles are similar, the RPS branch is connected to the vertex of the isosceles triangle through the rotation pair, and the axis of the rotation pair is coplanar, which is perpendicular to the center and vertex of the circumcircle of the isosceles triangle ΔABC. The connecting line is parallel to the outer fixed platform plane. 4. The RPS branch chain according to claim 3, characterized in that: the linear telescopic device driving device is composed of a driving stepping motor, a synchronous pulley, a screw nut pair, a sliding rod, a sliding piston, and a pulley box , the output shaft of the drive stepping motor is connected with the lead screw through the synchronous belt drive. 5. The dish type solar tracking device based on a 3-RPS parallel mechanism according to claim 1, wherein the fixed platform is fixedly connected to the frame, and the bracket is fixedly installed on the foundation through the positioning mechanism plus fasteners or welding. specific location.

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