Sealing connection method of metal and glass of novel medium-high temperature solar energy heat collection pipe

Abstract

The invention discloses a sealing connection method of metal and glass of a novel medium-high temperature solar energy heat collection pipe, which relates to a method for matched sealing connection of two materials: the metal of kovar alloy and the glass of neutral borosilicate glass with the similar thermal expansion coefficients. The invention provides a novel method for manufacturing the metal glass medium-high temperature solar energy heat collection pipe. In the method, the difference of the thermal expansion coefficient of the kovar alloy and the thermal expansion coefficient of the neutral borosilicate glass is in a range between 5 percent and 10 percent, the difference of the thermal expansion coefficient of the transition section glass and the thermal expansion coefficient of the neutral borosilicate glass is in a range between 5 and 10 percent, the sealing connection temperature of the neutral borosilicate glass and the transition section glass is between 600 and 1000 DEG C, the heating temperature of the sealing connection region of the kovar alloy and the transition section glass is between 600 and 1200 DEG C, the length of the sealing connection opening is between 3 and 8 mm, and the whole sealing connection section of the neutral borosilicate glass, the transition section glass and the kovar alloy after the sealing connection carries out the annealing processing at the annealing temperature between 450 and 600 DEG C for 10 to 60 minutes.

Description

technical field [0001] The invention belongs to the field of solar energy applications, and in particular relates to a method for sealing metal and glass in a novel medium-high temperature solar vacuum heat collection tube. Background technique [0002] At present, in the manufacture of high-temperature solar vacuum heat collector tubes in metallic glass, due to the commonly used Kovar alloy and the commonly used solar high borosilicate glass (3.2×10 -6 -3.6×10 -6 / °C) has a certain difference in thermal expansion coefficient, so it is difficult to directly seal metal and glass. If you want to achieve matching sealing, there are two ways: [0003] 1. It is necessary to add multiple transition sections. The increase of the transition section increases the possibility of air leakage, which reduces the airtightness of the entire device; the transition section is too long to increase the proportion of the transition device to the entire heat collecting tube, reducing the collec...

AI Technical Summary

Problems solved by technology

[0003] 1. It is necessary to add multiple transition sections. The increase of the transition section increases the possibility of air leakage, which reduces the airtightness of the entire device; the transition section is too long to increase the proportion of the transition device to the entire heat collecting tube, reducing the collection efficiency. The heat collection efficiency of the heat pipe; while the domestic output of the transition glass in the middle is small and the price is high, which increases the production cost of the heat collection pipe; the process is complicated and not suitable for large-scale production

[0004] 2. It is necessary to change the thermal expansion coefficient of glass or metal. The thermal expansion coefficient of the commonly used Kovar alloy is 4.7×10 -6 -5.2×10 -6 / °C, the process of changing its expansion coefficient is very complicated, and mass production cannot guarantee the stability of its thermal expansion coefficient. Therefore, it is more convenient and feasible to choose to change the thermal expansion coefficient of glass. Since the neutral borosilicate glass has been mass-produced at present Conditions, many medical pharmacy bottles use this kind of neutral borosilicate glass

[0005] And other non-matching sealing technologies are not yet mature, the glass tube is easy to burst, and it is difficult to meet the requirements of high temperature work

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