How can the theoretical version numbers calculated by AspenPlus be applied in practice?
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There are very few theoretical plate numbers calculated by AspenPlus, but practical experience in the field shows that many more plates are required to separate the two substances. What’s the reason for this? What practical significance do the theoretical plate numbers calculated by AspenPlus have? I’ve been learning AspenPlus in a practical setting for a while now, and I’m a bit confused.
The calculations performed by any simulation software are merely a tool; the accuracy of these calculations depends on the simulator’s engineering experience, basic chemical engineering knowledge, as well as consideration of experimental data and the actual operating conditions of the equipment. Additionally, it is crucial that the thermodynamic approach be related to the reliability of the binary interaction parameters, and process optimization is also inseparable from this. As for the calculated number of theoretical plates being low and untrustworthy, that is normal, as there are many factors involved...
In my opinion, the greatest value of Aspen lies in its material property database and its capability for performing material balance calculations. As for the process calculations related to equipment such as towers and heat exchangers, these still require practical analysis based on specific projects, as process calculations for such equipment involve many structural aspects
It’s just a simulation; it’s not reality. Moreover, you mentioned theoretical plate numbers, but in practice it’s necessary to take into account plate efficiency as well as the specific characteristics of the material – such as whether it tends to get clogged, whether there are any other trace substances that can have an impact, whether it’s heat-sensitive, whether there is an azeotrope, and whether the design of the tower plates is appropriate
In many cases, the number of theoretical plates calculated by Aspen can serve as a guide for practical applications. As for the large differences you mentioned, it’s either due to problems with Aspen’s property data or issues related to the fluid dynamics of the actual tower