A two-stage CPC collector with spiral vacuum tubes

Abstract

This patent discloses a two-stage CPC collector with a spiral vacuum tube, including a spiral CPC vacuum heat collection tube, an outer CPC reflector, and an adjustable support frame; the spiral CPC vacuum heat collection tube is in the groove of the outer CPC reflector, and the two ends of the spiral CPC vacuum heat collection tube and the outer CPC reflector are connected to the adjustable support frame and supported by the adjustable support frame, and the relative positions among the CPC vacuum heat collection tube, the outer CPC reflector, and the adjustable support frame can be changed by adjusting the adjustable support frame. The CPC collector device adopts the design of outer CPC focusing + inner 360-degree CPC focusing, with high heat collection temperature and heat collection efficiency, and good adjustable performance, which is convenient for stepless adjustment of the position, height, CPC direction and shape of the CPC heat collection tube and the reflector, ensuring the high solar energy utilization rate and environmental adaptability of the CPC collector, and at the same time, the structure is simple, easy to assemble and disassemble, reusable, low cost, beautiful style, and has good promotion potential.

Description

Technical Field

[0001] The invention relates to a solar energy heat collecting device, in particular to a two-stage CPC heat collecting device which is adjustable in multiple directions, and belongs to the technical field of solar energy utilization. Background Art

[0002] As a clean, pollution-free renewable energy, the development and utilization of solar energy is considered an important part of the world's energy strategy. Solar water heaters have been successfully commercialized, and how to more effectively utilize solar energy has become a topic of research for scientists from all over the world.

[0003] Compound parabolic concentrator (CPC) is a non-imaging concentrator designed based on the principle of edge optics. In theory, the incident light within the receiving angle range will eventually reach the receiver directly or after reflection. For a given receiving angle range, it can achieve the maximum concentration ratio, so it is used in solar thermal and photovoltaic systems, non-tracking and tracking (secondary reflector) systems. CPC collectors have the smallest heat dissipation area, do not require tracking devices, and reduce costs, and can meet the needs of medium and high temperature heat collection.

[0004] At present, CPC solar medium and low temperature collectors have been promoted and applied to a certain extent. Compared with ordinary solar low temperature collectors, they can improve the collection temperature and collection efficiency within a certain range. However, due to the limitation of optical characteristics, the current CPC collectors are designed with low concentration ratios, and cannot achieve a higher collection temperature or the solar collection efficiency is very low when operating at a higher collection temperature. If a higher concentration ratio is designed, the sunlight receiving angle of the collector will be very small, and tracking is required to ensure the reception of sunlight, which loses the value and significance of the CPC collector, and requires a larger reflector. This situation has led to no obvious advantages of CPC collectors in performance and cost compared to non-concentrators, limiting the promotion and popularization of CPC collectors. The current built-in CPC collector tube uses a one-dimensional linear CPC reflector, which can only collect sunlight within a certain opening angle and is not suitable as a secondary reflector. The current CPC bracket has poor adjustability, is difficult to adjust the position of the collector tube and the reflector, and has poor versatility, or has a complex structure and high cost. These factors affect the further promotion and application of CPC solar collectors and the optimal use of solar energy. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects of the above-mentioned existing related CPC solar collectors, and to provide a CPC solar collector with two-stage focusing, high solar collection temperature and efficiency, good adjustable performance, suitable for fixing different types of CPC solar collectors, and convenient for stepless adjustment of the position, height, direction and shape of the solar collector tube and the CPC reflector.

[0006] In order to solve the above technical problems, the technical solution provided by this patent is: a two-stage CPC collector with a spiral vacuum tube is adopted, including a spiral CPC vacuum collector tube, an external CPC reflector, and an adjustable support frame; the spiral CPC vacuum collector tube is in the groove of the external CPC reflector and is located at the focusing point of the external CPC reflector; the two ends of the spiral CPC vacuum collector tube and the external CPC reflector are connected to the adjustable support frame and supported by the adjustable support frame; the spiral CPC vacuum collector tube and the external CPC reflector can be rotated on the adjustable support frame, and the relative positions among the CPC vacuum collector tube, the external CPC reflector and the adjustable support frame can be changed by adjusting the adjustable support frame.

[0007] As an improvement of the present invention, the spiral CPC vacuum heat collecting tube comprises a spiral heat collecting tube, a spiral CPC reflector, a spiral CPC reflector fixing rod, a heat collecting tube end cover, an expansion joint, a transition metal ring, and a glass tube; the spiral heat collecting tube is a spiral tubular structure, the spiral CPC reflector is a structure formed by a CPC curve along the spiral heat collecting tube, and the spiral heat collecting tube is located at the focusing point of the spiral CPC reflector; both ends of the glass tube are connected to the transition metal ring, the other end of the transition metal ring is connected to the expansion joint, and the other end of the expansion joint is connected to the heat collecting tube end cover, the closed space formed by the heat collecting tube end cover, the expansion joint, the transition metal ring, and the glass tube is a vacuum layer, and the spiral heat collecting tube and the spiral CPC reflector are located in the vacuum layer; both ends of the spiral CPC reflector are fixedly connected to the heat collecting tube end cover through the spiral CPC reflector fixing rod, and both ends of the spiral heat collecting tube pass through the heat collecting tube end cover.

[0008] As an improvement of the present invention, the adjustable support frame includes a Y-shaped support frame, a triangular support frame, an external CPC reflector support rod, a spiral heat collecting tube fixing buckle, and a rotating fixing rod; the Y-shaped support frame is a Y-shaped support frame formed by three support rods, the three support rods are provided with adjustment strip holes, and the center of the Y-shaped support frame is provided with a rotating shaft; the triangular support frame is a triangular support frame composed of three straight rods, the upper end of the triangular support frame is provided with a circular rotating shaft hole, and the lower part of the rotating shaft hole is provided with an adjustment fan-shaped hole; the external CPC reflector support rod is a straight rod with threaded rods at both ends, the spiral heat collecting tube fixing buckle is a U-shaped buckle with a threaded rod on the side, the rotating fixing rod is a threaded rod with an anti-slip ring on the end, the threaded rods on the external CPC reflector support rod and the spiral heat collecting tube fixing buckle pass through the adjustment strip holes and are fastened by nuts, and the rotating fixing rod passes through the adjustment fan-shaped hole and the adjustment strip hole and are fastened by nuts.

[0009] As an improvement of the present invention, the spiral heat collecting tube is covered with a solar selective absorption coating, the surface of the spiral CPC reflector is covered with a reflective layer, and the material of the transition metal ring is Kovar alloy.

[0010] Compared with the prior art, the advantages of the present invention are as follows: 1) The device is designed with a spiral CPC vacuum collector tube, which can collect sunlight from 360 degrees in a circular CPC focusing manner; the two-stage focusing is adopted to further concentrate the sunlight concentrated by the external reflector, which can improve the concentration ratio to achieve a higher collection temperature and collection efficiency; the thin spiral tube design adopted can reduce the heat dissipation area and improve the collection efficiency under the same light collection amount compared to the thick straight tube; the vacuum structure, expansion joint and transition metal ring are adopted to ensure that the collector tube can operate efficiently and stably under high temperature conditions.

[0011] 2) The adjustable support frame design adopted can simply and conveniently adjust the position of the spiral CPC vacuum collector tube and the external CPC reflector. It can adapt to CPC vacuum collector tubes and CPC reflectors of different models and sizes, and can adjust the relative position of the CPC vacuum collector tube and the external CPC reflector to achieve the best focusing effect. This design can achieve stepless continuous adjustment.

[0012] 3) The adjustable support frame design can easily and conveniently adjust the angle of the spiral CPC vacuum collector tube and the external CPC reflector. The best collector orientation can be selected according to time and season to improve the collection efficiency. Without the need for electric devices, it can better cooperate with the spiral CPC vacuum collector tube to achieve the ideal focusing effect.

[0013] 4) The device adopts the design of external CPC focusing + internal 360-degree CPC focusing, with high collection temperature and efficiency, and good adjustable performance. It is convenient to make stepless adjustments to the position, height, CPC orientation and shape of CPC collector tubes and reflectors, ensuring high solar energy utilization and environmental adaptability of CPC collectors. At the same time, it has a simple structure, is easy to assemble and disassemble, is reusable, has low cost, and is beautiful in style, with good promotion potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the structure of a two-stage CPC collector with spiral vacuum tubes;

[0015] Figure 2 It is a schematic diagram of the structure of the spiral CPC vacuum collector tube;

[0016] Figure 3 It is a cross-sectional view of the spiral CPC vacuum collector tube;

[0017] Figure 4 is a schematic diagram of the structure of an adjustable support frame;

[0018] Among them: 1 is a spiral CPC vacuum collector tube, 2 is an outer CPC reflector, 3 is an adjustable support frame, 4 is a spiral collector tube, 5 is a spiral CPC reflector, 6 is a spiral CPC reflector fixing rod, 7 is a collector tube end cap, 8 is an expansion joint, 9 is a transition metal ring, 10 is a glass tube, 11 is a vacuum layer, 12 is a Y-shaped support frame, 13 is a strip hole for adjustment, 14 is a rotating shaft, 15 is a triangular support frame, 16 is a rotating shaft hole, 17 is a fan-shaped hole for adjustment, 18 is an outer CPC reflector support rod, 19 is a spiral collector tube fixing buckle, 20 is a rotating fixing rod, and 21 is a nut. DETAILED DESCRIPTION

[0019] In order to enhance the understanding and recognition of the present invention, the present invention is further described and illustrated below in conjunction with the accompanying drawings and specific implementation methods.

[0020] Example 1

[0021] See also Figure 1, a two-stage CPC collector with a spiral vacuum tube is adopted, including a spiral CPC vacuum collector tube 1, an outer CPC reflector 2, and an adjustable support frame 3; the spiral CPC vacuum collector tube 1 is in the groove of the outer CPC reflector 2 and is located at the focusing point of the outer CPC reflector 2; the two ends of the spiral CPC vacuum collector tube 1 and the outer CPC reflector 2 are connected to the adjustable support frame 3 and supported by the adjustable support frame 3; the spiral CPC vacuum collector tube 1 and the outer CPC reflector 2 can rotate on the adjustable support frame 3, and the relative positions among the CPC vacuum collector tube 1, the outer CPC reflector 2 and the adjustable support frame 3 can be changed by adjusting the adjustable support frame 3.

[0022] Example 2

[0023] See also Figure 2 , Figure 3 As an improvement of the present invention, the spiral CPC vacuum heat collecting tube 1 comprises a spiral heat collecting tube 4, a spiral CPC reflector 5, a spiral CPC reflector fixing rod 6, a heat collecting tube end cap 7, an expansion joint 8, a transition metal ring 9, and a glass tube 10; the spiral heat collecting tube 4 is a spiral tubular structure, the spiral CPC reflector 5 is a structure formed by a CPC curve spiraling along the spiral heat collecting tube 4, and the spiral heat collecting tube 4 is located at the focusing point of the spiral CPC reflector 5; both sides of the glass tube 10 The end of the transition metal ring 9 is connected to the transition metal ring 9, the other end of the transition metal ring 9 is connected to the expansion joint 8, the other end of the expansion joint 8 is connected to the heat collecting tube end cover 7, the closed space formed by the heat collecting tube end cover 7, the expansion joint 8, the transition metal ring 9, and the glass tube 10 is a vacuum layer 11, and the spiral heat collecting tube 4 and the spiral CPC reflector 5 are located in the vacuum layer 11; the two ends of the spiral CPC reflector 5 are fixedly connected to the heat collecting tube end cover 7 through the spiral CPC reflector fixing rods 6, and the two ends of the spiral heat collecting tube 4 pass through the heat collecting tube end cover 7.

[0024] Example 3

[0025] See also Figure 4As an improvement of the invention, the adjustable support frame 3 includes a Y-shaped support frame 12, a triangular support frame 15, an outer CPC reflector support rod 18, a spiral collector tube fixing buckle 19, and a rotating fixing rod 20; the Y-shaped support frame 12 is a Y-shaped support formed by three support rods, and the three support rods are provided with adjustment strip holes 13, and the center of the Y-shaped support frame 12 is provided with a rotating shaft 14; the triangular support frame 15 is a triangular support composed of three straight rods, and the upper end of the triangular support frame 15 is provided with a circular rotating shaft hole 16 , a fan-shaped hole 17 for adjustment is provided below the rotating shaft hole 16; the outer CPC reflector support rod 18 is a straight rod with threaded rods at both ends, the spiral heat collecting tube fixing buckle 19 is a U-shaped buckle with a threaded rod on the side, and the rotating fixing rod 20 is a threaded rod with an anti-slip ring at the end. The threaded rods on the outer CPC reflector support rod 18 and the spiral heat collecting tube fixing buckle 19 pass through the adjusting strip hole 13 and are fastened by the nut 21, and the rotating fixing rod 20 passes through the adjusting fan-shaped hole 17 and the adjusting strip hole 13 and is fastened by the nut 21.

[0026] Example 4

[0027] See also Figure 3 As an improvement of the present invention, the spiral collector tube 4 is covered with a solar selective absorption coating, the surface of the spiral CPC reflector 5 is covered with a reflective layer, and the material of the transition metal ring 9 is Kovar alloy.

[0028] Working principle and process:

[0029] See also Figure 1-Figure 4 Part of the sunlight directly irradiates the spiral CPC vacuum collector tube 1, and part of it is reflected by the outer CPC reflector 2 and then irradiates the spiral CPC vacuum collector tube 1; part of the sunlight irradiating the spiral CPC vacuum collector tube 1 directly irradiates the spiral collector tube 4, and part of it is reflected by the spiral CPC reflector 5 and then irradiates the spiral collector tube 4; the sunlight irradiating the spiral collector tube 4 is absorbed by the solar selective absorption coating and converted into heat energy to heat the medium in the spiral collector tube 4.

[0030] The expansion joint 8 and the transition metal ring 9 are used to eliminate the stress generated by the high temperature in the spiral CPC vacuum collector tube 1 .

[0031] By changing the fixed position of the outer CPC reflector support rod 18 on the adjusting strip hole 13, the position of the outer CPC reflector 2 can be adjusted and adapted to outer CPC reflector 2 of different sizes and models; by changing the fixed position of the spiral heat collecting tube fixing buckle 19 on the adjusting strip hole 13, the position of the spiral CPC vacuum heat collecting tube 1 can be adjusted and adapted to spiral CPC vacuum heat collecting tube 1 of different sizes and models; by changing the fixed position of the rotating fixing rod 20 on the adjusting fan-shaped hole 17, the angle of the Y-shaped support frame 12 can be adjusted.

[0032] The present invention may also combine at least one of the technical features described in Examples 2, 3, and 4 with Example 1 to form a new implementation manner.

[0033] It should be noted that the above embodiments are merely preferred embodiments of the invention and are not intended to limit the protection scope of the invention. The protection scope of the invention shall be subject to the claims.

Claims

1. A two-stage CPC collector with spiral vacuum tubes, characterized in that The two-stage CPC collector with spiral vacuum tubes comprises a spiral CPC vacuum heat collection tube, an outer CPC reflector, and an adjustable support frame; the spiral CPC vacuum heat collection tube is in the groove of the outer CPC reflector and is located at the light focusing point of the outer CPC reflector; both ends of the spiral CPC vacuum heat collection tube and the outer CPC reflector are connected to the adjustable support frame and supported by the adjustable support frame; the spiral CPC vacuum heat collection tube and the outer CPC reflector can rotate on the adjustable support frame, and the relative positions among the CPC vacuum heat collection tube, the outer CPC reflector, and the adjustable support frame can be changed by adjusting the adjustable support frame; The spiral CPC vacuum heat collecting tube comprises a spiral heat collecting tube, a spiral CPC reflector, a spiral CPC reflector fixing rod, a heat collecting tube end cap, an expansion joint, a transition metal ring, and a glass tube; the spiral heat collecting tube is a spiral tubular structure, the spiral CPC reflector is a structure formed by a CPC curve spiraling along the spiral heat collecting tube, and the spiral heat collecting tube is located at the focusing point of the spiral CPC reflector; both ends of the glass tube are connected to the transition metal ring, the other end of the transition metal ring is connected to the expansion joint, and the other end of the expansion joint is connected to the heat collecting tube end cap, the closed space formed by the heat collecting tube end cap, the expansion joint, the transition metal ring, and the glass tube is a vacuum layer, and the spiral heat collecting tube and the spiral CPC reflector are located in the vacuum layer; both ends of the spiral CPC reflector are fixedly connected to the heat collecting tube end cap through the spiral CPC reflector fixing rod, and both ends of the spiral heat collecting tube pass through the heat collecting tube end cap; The adjustable support frame includes a Y-shaped support frame, a triangular support frame, an external CPC reflector support rod, a spiral heat collecting tube fixing buckle, and a rotating fixing rod; the Y-shaped support frame is a Y-shaped support frame formed by three support rods, the three support rods are provided with adjustment strip holes, and the center of the Y-shaped support frame is provided with a rotating shaft; the triangular support frame is a triangular support frame composed of three straight rods, the upper end of the triangular support frame is provided with a circular rotating shaft hole, and the lower part of the rotating shaft hole is provided with an adjustment fan-shaped hole; the external CPC reflector support rod is a straight rod with threaded rods at both ends, the spiral heat collecting tube fixing buckle is a U-shaped buckle with a threaded rod on the side, the rotating fixing rod is a threaded rod with an anti-slip ring on the end, the threaded rods on the external CPC reflector support rod and the spiral heat collecting tube fixing buckle pass through the adjustment strip holes and are fastened by nuts, and the rotating fixing rod passes through the adjustment fan-shaped hole and the adjustment strip hole and are fastened by nuts.

2. A two-stage CPC collector with spiral vacuum tubes according to claim 1, characterized in that The spiral heat collecting tube is covered with a solar selective absorption coating, the surface of the spiral CPC reflector is covered with a reflective layer, and the material of the transition metal ring is Kovar alloy.

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