Are the pressures at the top and bottom of the tower as well as those at the heat exchanger, which are usually entered in Aspen, absolute pressures or gauge pressures?
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Are the pressures at the top and bottom of the tower as well as those at the heat exchanger, which are usually entered in Aspen, absolute pressures or gauge pressures? Is the pressure in the top condenser the pressure at the top of the distillation column? (Similarly, is the pressure in the reboiler the pressure at the bottom of the column?) What does the pressure of a heat exchanger refer to? For example, in the case of a shell-and-tube heat exchanger, does it refer to the pressure on the tube side or the shell side?
Are the pressures at the top and bottom of the tower as well as those at the heat exchanger, which are usually entered in Aspen, absolute pressures or gauge pressures? Gauge pressure is generally used for calculations. Is the pressure in the top condenser the pressure at the top of the distillation column? (Similarly, is the pressure in the reboiler the pressure at the bottom of the column?) Strictly speaking, no – there is a section of pipe from the top of the column to the condenser, and there is a certain pressure drop along that path. The condenser pressure will be slightly lower than the tower top pressure. What pressure does the pressure of a heat exchanger refer to? For example, in the case of a shell-and-tube heat exchanger, does it refer to the pressure on the tube side or the shell side? The pressure tube side and shell side of the heat exchanger are separate from each other.
You can set the unit yourself to determine whether it should be absolute pressure or gauge pressure; generally, factories and design institutes use gauge pressure. Just make sure it matches the actual value
Okay, thank you. . . . . . . . . . . . . . .
Got it, thanks. . . . . . . . . . . . . . . . . . . . . .
I’m also at a loss as to how to approach this issue – how exactly should one \"set up the unit\"? ? Or where should the settings be made?
When setting the unit, calculations are performed using absolute pressure. Then, when outputting the result, it should be changed to gauge pressure; this approach is intended to make it easier for production staff to read the value and avoid errors. :lol
It is usually absolute pressure; if you’re not sure, you can enter it with a ‘a’ (absolute pressure) or a ‘g’ (gauge pressure) at the end. It depends on whether the issue is of a design nature or an operational one; absolute pressure is usually used in design ； The on-site readings are generally gauge pressure, which can be entered into software for operational calculations and diagnostics.