Raw material glass tubetube is composed of inner glass tube with solar selective absorption coating and coaxial cover glass tube. One end of the inner glass tube is a closed dome shape and is supported by the support with getter in the end of the cover glass tube sealing off. The closed section is a condensing section between the cover glass tube, the inner glass tube or the diameter of the cover glass tube and the inner glass tube, and the heat pipe is located in the closed space. Working fluid.
tube consists of two concentric circular glass tubes inside and outside. The selective absorption wax with high absorptivity and low emissivity is deposited on the outer surface of the inner tube to form a heat absorber. High vacuum is pumped between the inner and outer tube interlayers. The shape of the solar vacuum tube is like a slender warm water bottle gallbladder, as shown in the figure below. It uses a single-ended opening to melt the inner and outer nozzles into a ring; the other end is a closed hemisphere with a round head, supported by a spring card, which can be freely expanded to cushion the stress caused by the thermal expansion and cold contraction of the inner and outer pipes. The spring card is equipped with an antigassing agent. When it evaporates, it can absorb the gas generated during the vacuum operation and maintain the vacuum in the tube.