Heat treatment of the shell side of the heat exchanger
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There is one existing heat exchanger; the fluid flowing in the shell side is highly hazardous, while the fluid in the tube side is circulating water. The material used is Q245R. The design requirements specify that stress-relief heat treatment be carried out after welding in the shell side. I would like to ask whether this heat treatment will have any impact on the heat exchange tubes? How is heat treatment time calculated?
What type of heat exchanger are you referring to? Is it a fixed-tube-sheet type? The heat treatment of the shell side of floating heads and U-tubes has nothing to do with the tube bundle
The shell side is heat-treated first before the tube side is installed; it has nothing to do with the heat exchange tubes. The heat treatment time and temperature can be found in NB/T47015
It is possible to treat only the welds, without the need for treatment of the entire area.
In the case of a fixed-tube-sheet heat exchanger, the tube sheet can be welded to the shell; after passing non-destructive testing, stress-relief heat treatment can be carried out, followed by the installation of the heat exchange tubes. After welding is complete, local heat treatment can be applied to the tube joints. If the shell is heat-treated together with the heat exchange tubes, it is necessary to consider the impact of the different expansion rates between the heat exchange tubes and the shell on the tubes and the tube fittings.
Determine the heat treatment methods based on the type of heat exchanger!
Don’t the shell side contain heat exchange tubes? It is a fixed-tube-sheet heat exchanger
It is best to leave one end of the heat exchange tube unwelded and weld it after heat treatment.