The market is a single opening or more than double openingsWhich is more expensive?Double opening to find you
Now there are only two kinds of vacuum tubes used in solar energy. There seems to be nothing else. You can go to the white paper on the solar water heater. Now the vacuum tube is the best, you can freeze water. The double vacuum tube is used in large projects, even more than the box, because the double real air duct heat collection effect than ordinary vacuum tube.
Another kind of glass metal sealing straight pipe, the use of internal metal pipes, external use glass to keep the vacuum, the metal part of the bellows to offset expansion. The safety factor of the vacuum tube is greatly improved, the key is that the fusion state of the glass and the metal is not easy to form, and the utility model is generally used for two kinds of sealing and sealing of the glass metal. More reliable is the closure of the closure, such a vacuum tube in the slot type thermal power generation is more, the price is very high.
Because the glass tube to absorb sunlight, heat, swelling; the outer tube due to the existence of vacuum, low temperature, no expansion, so that the vacuum tube of their stress form, easy to break. The general market solutions into two kinds, one is bamboo, a spiral. However, these two basic are not very reliable, glass products, easy to break.
