Graphite-filled vacuum glass tube closed-loop capillary pipe solar thermal-collecting tube

Abstract

The invention discloses a graphite filled vacuum glass tube closed loop capillary solar heat collection tube, which belongs to the field of solar heat collector. The solar heat collection tube is characterized in that the device comprises a finned header tube, capillary metal tubes, an external glass tube, an internal glass tube, graphite packing, a thermal insulated seal head, an elastic support and a thermal insulated liner tube; according to the vacuum glass tube, the external surface of the internal glass tube is coated with solar energy selective absorption paint, and space between the internal and external glass tubes is vacuumed; the graphite packing is compactly packed among the internal glass tube, the capillary metal tubes and the thermal insulated liner tube; and the inner diameter of each capillary metal tube is between 2 and 5 millimeters, and the capillary metal tubes are connected with the finned header tube to form a closed pipeline system. The capillary metal tubes are filled with water, Freon or other heat transfer mediums so as to complete the process of solar heat collection and conveying. The graphite filled vacuum glass tube closed loop capillary solar heat collection tube has the advantages that a plurality of U-shaped capillary tubes increase the heat exchange area of the working media within the limited space of the glass tubes, and improve the heat transfer performance of the heat collection tube; and simultaneously the graphite packing facilitates the improvement of the heat collection efficiency of the heat collection tube.

Description

technical field [0001] The invention belongs to the field of solar heat collectors, and relates to a solar heat collecting element with high pressure bearing capacity, high heat collection efficiency and good heat exchange performance realized by using a plurality of U-shaped metal capillaries. Background technique [0002] Solar collectors are the key equipment of various solar energy utilization systems, and solar collector tubes are the core of solar collectors. At present, there are two types of solar collectors: flat plate collectors and vacuum tube collectors, and the latter is the most widely used and most likely to realize high-temperature collectors in China. The existing vacuum glass tube heat collector uses a single U-shaped tube, and the U-shaped tube is installed on the aluminum wing sheath with ribs. For this type of U-shaped tube vacuum glass tube heat collector, due to consideration of installation and thermal expansion There is a large contact thermal resis...

AI Technical Summary

Problems solved by technology

The existing vacuum glass tube heat collector uses a single U-shaped tube, and the U-shaped tube is installed on the aluminum wing sheath with fins. For this type of U-shaped tube vacuum glass tube heat collector, due to consideration of installation and thermal expansion There is a large contact thermal resistance between the aluminum wing sheath and the glass tube, and between the U-shaped tube and the fins, which affects the transfer efficiency of solar energy from the outside to the inside of the U-shaped tube.

For ordinary vacuum glass tube collectors without U-shaped tubes, there are problems that the tubes use water as the medium, and the glass tubes are easy to freeze and crack in winter. Thermal system pressure requirements and other issues

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