Tube-in-tube heat exchanger

In the industrial production process, shell and tube heat exchangers are widely used heat exchange equipment. Compared to other types of heat exchangers with a wall, they offer a much larger heat transfer area per unit volume, and also exhibit better heat transfer efficiency. During operation, attention should be paid to the following points:
1. Initially, operate at a slow pace, allowing for preheating, and gradually increase the temperature.
2. Ensure proper preheating of the pressure relief valve and adjustments post-commissioning.
3. When starting the unit, the cold side valve should be opened first, followed by the hot side valve after stabilization; when shutting down, the hot side valve should be closed first, then the cold side valve.
4. After normal operation, close the bypass valve of the steam-water heat exchanger drain separator, and the separator will start working normally. If the separator temperature is too low, such as below 50℃, the bypass valve can be opened for operation. If the separator temperature is too high, such as above 90℃ and the condensate system is running at no pressure, close the bypass valve to prevent steam from passing through, avoiding steam-water shock.
5. Operation Adjustment: The operation adjustment primarily adjusts water supply temperature and flow based on weather changes. Operators mainly control the steam flow into the heat exchanger of the heat recovery unit to achieve the purpose of controlling the outlet water temperature. When the outdoor temperature is high, temperature control is achieved by adjusting the number of operating units and steam flow. However, attention should be given to minimizing the frequency of heat exchanger operation to avoid leakage due to frequent start-ups and shutdowns. When the heating load decreases, pay attention to steam pipeline draining to prevent water hammer inside the heat exchanger. The operation adjustment should be coordinated across the entire system with unified allocation.
 

Shell-and-tube heat exchanger main technical parameters