Questions about heat exchanger temperature
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The design temperature of the tube bank is 220°C; it is a material return heat exchanger and is used intermittently. However, at a temperature of around 200°C (in the process fluid side), with circulating water used for cooling (on the shell side), could the temperature of the circulating water exceed the designed value of 60°C? Could vaporization occur in such a situation?
Since it is a return material heat exchanger, the return material flow rate can be controlled. If the return temperature of the cooling water is too high, simply reduce the material withdrawal flow rate. If the heat exchanger has been calculated for the heat load, such a thing should not happen. When the return water temperature is excessively high, possible causes include fouling of the heat exchanger leading to poor heat transfer efficiency, insufficient circulation water flow (insufficient pressure difference or blocked pipes), or an excessive flow rate or temperature of the material.
For this, you control the flow rates in the shell side and tube side based on remote temperature measurement in order to regulate the temperature; of course, pressure also needs to be taken into account. Pressure, temperature, and flow meters or valves are three interrelated parameters
What is the basis for a design pressure of 0.9 in the shell side, and a pressure test pressure of 1.92? If it is the steam pressure corresponding to 220°C, then 0.9 is not appropriate ； As for whether vaporization will occur, it depends on the specific operating conditions. As long as the process data you provide are normal, there should be no problem. For example, if the flow rate of the circulating water deviates too much, that is, if it is too low, then vaporization is entirely possible, which can lead to water hammer effects, cause resonance in the cooler, and damage the equipment.
For this priority issue, I think you should consult the manufacturer of the equipment itself. If you are able to perform heat load calculations, you can estimate an initial figure; you need to take into account the current efficiency of the equipment, its heat exchange rate, as well as parameters such as the flow rates and temperatures of the inlet and outlet water. Unnecessary losses and vaporization can be reduced through appropriate adjustments.
What is being produced under these operating conditions of yours?
The pressure in the pipe is very high; if the flow velocity inside the pipe reaches a turbulent state, the water inside the pipe will not vaporize.