The main function of the expansion joint of the heat exchanger is to compensate for the thermal expansion and contraction effects caused by the temperature change, thus reducing or eliminating the thermal stress caused thereby. The following is a detailed explanation of the action of the expansion joint of the heat exchanger:
Compensate for thermal expansion and contraction：
When the heat exchanger is working, the tube bundle and shell of the heat exchanger will expand and contract due to the temperature change of the heat transfer medium.
The expansion joint absorbs the dimensional changes caused by thermal expansion and contraction through the effective expansion and contraction deformation of its bellows.
Reduce axial load：
Temperature changes cause different thermal expansions between the tube and the shell, which in turn generate axial loads.
Expansion joints can reduce these axial loads and alleviate temperature differential stresses on tubes, tube sheets, and shells.
Reduce temperature differential stress：
Temperature changes can cause a temperature difference between the tube and the housing, which creates temperature differential stresses.
Through the compensation action of the expansion joint, these temperature difference stresses can be reduced, and the strength damage, instability damage and tube pull-off damage can be avoided.
Avoid destruction：
The expansion joint can avoid the tensile damage of the shell and the heat exchange tube, the instability of the heat exchange tube and the pulling off of the heat exchange tube from the tube sheet.
By reducing axial loads and temperature differential stresses, the expansion joint helps protect the heat exchanger from damage.
Improve tube sheet design：
By reducing the stress of the tube sheet caused by the difference in thermal expansion, the expansion joint allows the tube sheet to be appropriately thinned, thereby saving material and reducing cost.
Noise and vibration reduction：
In some cases, expansion joints can also be used to reduce vibration and noise in the plumbing system.
Improve service life：
By reducing thermal and mechanical stresses, the expansion joint helps to extend the life of the heat exchanger.
Adaptive displacement：
The expansion joint can compensate not only for axial displacement, but also for lateral and angular displacement, providing all-round compensation functions.
Protect Devices：
The expansion joint can ensure that the heat exchanger can operate safely when the temperature changes, and avoid the equipment damage caused by excessive stress caused by the temperature change.
Summary
The heat exchanger expansion joint is an important component, which absorbs the displacement caused by temperature change through its characteristic flexible structure, thus reducing the stress and load caused by thermal expansion and contraction. This helps to protect the safety and stability of the heat exchanger and other related equipment, ensuring that the system can operate reliably for a long time.