Glass-metal heat sealing material and method of heat-pipe evacuated solar collector tube

Abstract

The invention discloses glass-metal heat sealing material and method of a heat-pipe evacuated solar collector tube. One end of a glass tube is sintered into a glass flange; the end face of the flange and the surface of a Fe-Ni expansion alloy end cover are respectively cleaned and deoiled; an annular welding wire prepared from the glass-metal heat sealing material is clamped in the middle, wherein the sealing temperature is 0.6-0.9 times of the melting point of the welding wire, the exerted impact pressure is 70-500kg / cm<2>, and the time is 0.5 seconds to 2 minutes; the glass-metal heat sealing material is selected from any one of metal substances or metal alloy of Mg, Be, V, Co and Ni,the metal alloy contains nickel and silicon, the mass fraction of the nickel in the metal alloy is 1-30%, the mass fraction of the silicon is 1-30%, and base metal is selected from any one of Mg, Be, V and Co. The corrosion resistance, the welding temperature, the fatigue strength and the malleability of the welding line disclosed by the invention are improved; the welding wire is more tightly combined with glass and metal; the air leak rate is reduced; and the service life is prolonged.

Description

Technical field: [0001] The invention relates to the technical field of glass-metal thermocompression sealing, in particular to a glass-metal thermocompression sealing material and method for a heat pipe type vacuum heat collecting tube. Background technique: [0002] Solar water heater is the most typical technology in the field of low temperature application of solar energy. By the end of 2010, the number of water heaters in the world reached 187.5 million m 2 , of which China has 150 million m 2 , accounting for 80% of the world, is the country that utilizes the most solar thermal energy in the world, and its annual output reached 31 million m in 2008 and 2009 respectively 2 and 42 million m 2 , an increase of 32.5% and 35.5% respectively over the previous year. [0003] All-glass vacuum tube water heaters are the mainstream of solar water heaters in my country, accounting for more than 90% of the market share. With the development of the global trend of building int...

AI Technical Summary

Problems solved by technology

Since the main component of the sealed iron-nickel expansion alloy end cap is Fe, the outer electrons of Fe atoms are 4S 2 Orbital electrons, and the outer electron structures of these metals used in solders are not well matched with Fe atoms. For example, the outer electrons of Pb atoms are 6P 2 Orbital electrons and outer shell electrons of Al atoms are 3P 1 The orbital electrons and the outer shell electrons of Cu atoms are 4S 1 Orbital electrons, this mismatch makes it difficult for the solder metal to form a tight atomic-level seal with the iron-nickel expansion alloy end cap

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