In Hope Deepblue lithium bromide absorption chiller, the heat exchangers in the unit are generally of two types: plate heat exchangers and shell-and-tube heat exchangers. The expansion joint is a flexible compensation component installed on the shell of the shell-and-tube heat exchanger, protecting the heat exchange tubes and the entire equipment from damage.

I. Function of the Expansion Joint

During unit operation, the temperature differs between the tube side and the shell side inside the heat exchanger, leading to different amounts of thermal expansion between the shell and the internal tube bundle. This difference generates significant thermal stress, which can potentially pull apart pipes or cause leaks in severe cases. The expansion joint compensates for this differential expansion between the shell and the tube bundle through its own flexibility, thereby eliminating stress and protecting the equipment. The most common location for the expansion joint is in the middle of the shell, which is mechanically optimal for effectively compensating for displacement from both ends.

II. When is an Expansion Joint Required?

Not all heat exchangers require expansion joints, but they are crucial under the following conditions:

  1. Large Temperature Difference: An expansion joint is typically necessary when the temperature difference between the shell side and the tube side consistently exceeds a certain limit.

  2. Long Equipment Length: The longer the heat exchanger shell, the greater the cumulative thermal expansion, increasing the need for compensation.

  3. High Pressure: Higher shell side pressure can intensify the destructive potential of thermal stress.

Therefore, in the design of Hope Deepblue lithium bromide absorption units and heat exchanger, the decision to use an expansion joint is a careful one based on precise calculations. This ensures the long-term stability and high efficiency of the unit under various operating conditions.