Problems with heat exchange in heat exchangers
Thread Content
There are two heat exchangers on site; the shell side contains the liquid from the distillation pre-column bottom (methanol with a water content of around 3%), while the tube side is filled with circulating water. At the initial operation stage of the heat exchanger, the temperature difference in the upper return water was around 8–12°, while the temperature drop on the process side was about 30°. After approximately 24 hours of operation, the temperature difference in the circulating water was 2–3°, and the temperature drop on the process side was around 15°. No blockages in the tube side were detected during inspections. How to understand it? One is a double-pass heat exchanger with a heat exchange area of 326㎡, and the other is of the fixed-tube-sheet type with a heat exchange area of 106㎡. Please ask the experienced members of the forum for guidance!
If it’s blocked, check the pressure； If it’s not blocked, check if there’s a short circuit.
The temperature difference on both sides has decreased, which indicates that the heat transfer amount is lower. Could it be that the flow rate on one side is lower?
The changes after 24 hours of operation indicate a reduction in the overall heat load; the main reason for this is likely changes in operating parameters (such as an increase in the circulating water flow rate or a decrease in the inlet temperature of the process fluid), and it is probably not due to equipment failure
It is recommended that a flowchart for such issues would be helpful for facilitating discussion. Should we check the coolant flow rate? Is there any air in the cooler, which could reduce the heat exchange area? Is the fluid flow distributed unevenly between the two coolers??? Additionally, if there are problems that arise during the initial operation of newly installed equipment, it is still necessary to contact the design team for an explanation. For reference.