Inner-expanded-type solar vacuum heat-collecting pipe

Abstract

The invention relates to an internal expansion groove type solar vacuum heat collection tube, which belongs to the technical field of solar heat collection facilities. The vacuum heat collecting tube includes an outer glass tube, the glass tube is set on the metal tube in the middle, and the metal tube is coated with a heat-absorbing coating. The middle of the metal tube is broken and connected by a wave expansion joint. The alloy transition pieces are respectively sealed with the extended ends of the two sections of metal tubes, the glass tube, the metal tube and the corrugated expansion joint are vacuumed to form a vacuum layer, and the middle part of the metal tube and the glass tube are respectively equipped with self-centering supports . The invention internally digests the expansion of the metal tube larger than the glass tube, simplifies the installation and connection structure; at the same time, it has sufficient strength and rigidity, and is convenient for system installation and integration, and is especially suitable for high-temperature and high-power solar thermal power generation and other occasions.

Description

technical field [0001] The invention relates to a vacuum heat collection tube, in particular to a structural improvement of the vacuum heat collection tube used in a solar heat utilization system, and belongs to the technical field of solar heat collection facilities. Background technique [0002] The vacuum heat collector is the core device in the solar heat utilization system. The typical structure of the existing vacuum heat collecting tube is as described in Chinese Patent Application No. 95117947. The outer glass tube is set on the metal tube in the middle, and the two ends are sealed and connected. To prevent heat loss, the metal pipe is coated with a heat-absorbing coating to absorb the heat of the sun. The problem in the use of this type of heat collecting tube is: because the expansion coefficient of the metal tube is much larger than that of the glass tube, when the temperature is high, the expansion of the metal tube cannot be digested in the heat collecting tube...

AI Technical Summary

Problems solved by technology

However, practice has proved that this kind of vacuum heat collecting tube with bellows as the inner tube is concentrated on the glass tube, obviously insufficient in strength and rigidity, limited in length, and has a large flow resistance, which cannot meet the needs of high-power heat collection.

In addition, its structure relying on the metal bowl as a transition piece is not only complicated in process, but also unreliable in connection with the glass tube, difficult to withstand high temperature, and prone to leakage

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