CN2566193Y - Double-through glass-metal vacuum solar heat collecting pipe with direct compensation internal pipe - Google Patents

Abstract

The invention relates to a double-pass glass-metal vacuum solar heat collecting tube with a direct compensating inner tube, relating to the structural design of a double-pass glass-metal vacuum solar heat collecting tube. The utility model is mainly composed of a glass outer tube, a metal inner tube coated with a selective absorption coating on the surface, an exhaust tube, an outer tube connected to both ends of the inner tube, and a metal cap sealed with both ends of the inner and outer tubes. , There is a vacuum interlayer between the outer tube and the inner tube, and the metal inner tube is all or partially corrugated metal tube. Since the metal inner tube is directly processed into a corrugated tube, one end of the inner tube does not need to be sealed with a length compensator (bellows), not only the structure of the inner tube is simple, but also the welding seam is reduced, the probability of air leakage is reduced, and the yield is improved. The compression resistance of the whole tube is increased; the inner tube and the corrugated tube are combined into one, which simplifies the process and reduces the cost; it is also possible to process corrugated tubes of different lengths on the inner tube according to the working conditions of the whole tube, which greatly expands the solar The scope of application of vacuum heat collecting tubes.

Description

Double-pass glass-metal vacuum solar collector with direct compensating inner tube

Technical field

The utility model relates to a vacuum solar heat collecting tube, in particular to a structural design of a double-pass glass-metal vacuum solar heat collecting tube.

Background technique

The glass-metal vacuum solar collector tube is composed of a transparent glass outer tube and a metal inner tube coated with a selective absorption coating. A double-pass heat collecting tube is formed, and the interlayer between the inner and outer tubes is evacuated.

Patent No. 99107429 relates to a glass spiral all-glass double-pass vacuum solar heat collector with a solar spectrum absorbing coating. The applicant tried to use the structural form of the spiral tube to adjust the length change of the inner tube due to cold and heat, but because glass is a brittle material without elastic deformation, the above-mentioned purpose cannot be achieved, and the heat collecting tube will inevitably burst.

Patent Nos. 87210032 and 99241883.6 are glass-metal structure vacuum solar collector tubes with single-ended openings, that is, only one end is sealed with a metal inner tube and a glass outer tube to form an opening, which is called an open end; the metal inner tube at the other end is free. state, called the free end. The outer surface of the inner tube is coated with a selective absorbing coating. It is subject to changes in cold and heat, resulting in a change in length. It is adjusted by the free end to avoid the stress of the glass outer tube and cause bursting. This collector tube is only suitable for parallel connection, which limits its range of use.

Patent No. ZL01224848.7 and Publication No. CN1321865A relate to a straight-through type (both ends open) glass-metal structure vacuum solar collector tube, that is, the inner tube has no free end. In order to eliminate the length change of the inner pipe due to the change of cold and heat, a length compensator (bellows) is sealed at one end of the inner pipe, and then connected with the outer pipe. Its disadvantage is that the inner tube must be hermetically sealed with the bellows, and Ar arc welding, plasma welding, or other brazing methods are used for sealing. There are corresponding molds or fixtures, or even accessories during welding, which not only increases the cost and difficulty of pipe making, but also increases the process will inevitably affect the yield of the whole pipe. The structure is shown in Figure 1.

Utility model content

The purpose of this utility model is to address the deficiencies and defects of the prior art, and propose a new type of double-pass glass-metal vacuum solar collector tube that combines the inner tube and the bellows into one, so as to further simplify the product structure and improve the quality of the finished product. rate, the purpose of reducing production costs.

The purpose of this utility model is achieved through the following technical solutions: a double-pass glass-metal vacuum solar collector tube with a direct compensation inner tube, mainly composed of a glass outer tube and a metal inner tube coated with a selective absorbing coating on the surface , an exhaust pipe, an outer pipe connected to both ends of the inner pipe and a metal cap sealed to both ends of the inner and outer pipes, the outer pipe and the inner pipe are vacuum sandwiched, and its technical feature is that the metal The inner tube is all or partly corrugated metal tube.

Compared with the prior art, the present invention does not need to seal a length compensator (bellows) at one end of the inner tube because the metal inner tube is directly processed into a corrugated tube in whole or in part, which not only has a simple structure of the inner tube but also reduces welding Seams reduce the chance of air leakage, improve the yield, and increase the pressure resistance of the whole tube; the inner tube and the bellows are combined into one, which can simplify the process and reduce the cost; the inner tube can be installed according to the working conditions of the whole tube Processing corrugated tubes of different lengths greatly broadens the application range of solar vacuum heat collectors.

Description of drawings

Fig. 1 is the schematic composition diagram of the structure of the existing double-pass vacuum solar heat collecting tube.

Fig. 2 is the overall structure diagram of the utility model embodiment.

In the figure: 1-metal cap; 2-glass outer tube; 3, 4-outer tube; 1, 5, 6, 8, 10-metal cap; 7-corrugated tube; 9-metal inner tube; 11-exhaust Tube; 12-getter; 13-selective absorption coating; 14-vacuum interlayer; 16-support ring; 16-metal mesh.

Detailed ways

Below in conjunction with accompanying drawing, further illustrate the concrete structure of the present utility model and best embodiment mode:

Fig. 2 is the overall structural diagram of the utility model embodiment, and it comprises glass outer tube 2, the outer tube 3,4 that links to each other with inner tube two ends respectively, the metal inner tube 9 that surface is plated with selective absorbing coating 13, Exhaust pipe 11, vacuum interlayer 14, metal caps 1, 5, 6, 8 and 10 and getter 12. The corrugated tube is canceled in the figure, and the inner tube is directly processed into a corrugated tube. The heat collecting tube includes a glass outer tube 2 which is highly transparent to sunlight and a metal inner tube 9 which has a high effect of absorbing sunlight. The glass tube 2 and the metal cap 1 are welded and sealed to form an outer tube to keep airtight; the metal cap 6 is sealed to the exhaust pipe 11 to keep airtight; the outer tube 3 is sealed to the metal caps 5 and 8 respectively to keep airtight; The outer pipe 4 is sealed with the metal caps 6 and 10 respectively to keep it airtight; the airtight welded pipe is made of a metal strip, and the corrugated inner pipe 9 is processed into a corrugated inner pipe 9 by a bulging process, and then annealed at high temperature; after cooling, vacuum Plating selective absorbing coating; spot welding non-evaporable getter 12 at least one end of the inner tube. The two ends of the inner tube are respectively sealed with metal caps 8 and 10 to keep airtight; the metal caps 1 and 5, and metal caps 1 and 6 are sealed to keep airtight. The gap between the inner and outer pipes is evacuated to form a vacuum interlayer 14 .

The utility model can work in high, medium and low temperature range conditions of the heat collecting tube, that is, the range of its length needs to be adjusted, all or part of it can be processed into a corrugated shape by an expansion process, and annealed at a high temperature, and then directly in the The outer wall of the entire inner tube is coated with a selective absorbing coating to form a high-absorbing metal inner tube that itself has the function of compensating for its length change.

Claims (1)

1. A double-pass glass-metal vacuum solar heat collector with a direct compensation type inner tube, mainly composed of a glass outer tube, a metal inner tube coated with a selective absorption coating on the surface, an exhaust pipe, and connected to both ends of the inner tube The outer tube and the metal cap sealed with both ends of the inner and outer tubes, the outer tube and the inner tube is a vacuum interlayer, characterized in that: the metal inner tube is made of corrugated metal in whole or in part. Tube.

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