As the main component of the heat exchanger, the working performance and sealing of the heat exchanger tube have a vital impact on the operation effect of the entire heat exchanger. Heat exchanger tube expansion can effectively ensure the sealing and stability of the heat exchanger tube, improve the heat exchange efficiency, and is an important means of heat exchanger maintenance and optimization. So, under what circumstances is it necessary to use the heat exchanger tube expansion technology?
The basic concept and working principle
of expansion:
Expansion is a common name for mild
expansion. By performing mild plastic deformation between the heat exchanger
tube and the tube sheet, the gap between the two is eliminated to prevent the
shell-side medium from entering the gap and causing gap corrosion. During
expansion, the expansion force of the tube expander on the tube is small, and
the radial deformation of the tube is also small. Therefore, it cannot
withstand a large pull-off force and only plays a sealing role.
The situations in which heat exchanger
tubes need to be expanded mainly include the following:
1. The tube temperature is too high: When
the temperature of the heat exchanger tube is too high, it is easy to cause the
tube to deform or break. At this time, expansion treatment is required to
enhance the stability and high temperature resistance of the tube.
2. Water leakage: If water leakage is detected in the heat exchanger, it may be due
to loose connection or corrosion damage between the tube and the tube sheet.
The expansion can re-fix the tube, solve the leakage problem, and increase the
service life of the heat exchanger.
3. Replace other pipelines: When replacing other
pipelines or tubes of the heat exchanger, if the expansion treatment is not
performed, the connection between the tube and the tube sheet may fail,
affecting the working efficiency of the heat exchanger. Therefore, expansion
treatment is required when replacing the pipeline to ensure the tight
connection between the tube and the tube sheet.
Advantages and disadvantages of
expansion:
1. Advantages: The expansion structure is simple and the tube is easy to repair;
it can increase the heat transfer area, improve the heat transfer efficiency,
increase the stability and reliability of the heat exchanger tube, and improve
the corrosion resistance and mechanical strength.
2. Disadvantages: Since the expansion force is small during expansion, it cannot
withstand a large pull-off force, and the reliability of the connection is low.
Summary
In short, the expansion technology of heat
exchanger tubes is of great significance in ensuring the sealing, stability and
heat exchange efficiency of heat exchangers. Heat exchanger expansion is widely
used in various industrial applications, such as papermaking, metallurgy,
petroleum, chemical industry and other industrial fields, as well as boilers,
water heaters, air conditioners and other fields. In actual operation,
engineers should choose the appropriate expansion time and method according to
the specific situation to ensure the normal operation and long-term stability
of the heat exchanger.