ASPEN tower calculation type
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In the tower settings of ASPEN, there is a Calculation type option, with two choices available. What does “Rate-based” mean? How do I set it to rate-based? I have version 2006, and when I try to do this, I get the message \"Cannot change to rate-based unless rateset is enabled.\" I’m not sure what’s going on Please give me some advice!
1. Rate-based: In general vapor-liquid equilibria, the effect of diffusion at the vapor-liquid interface is ignored. Some tower calculations (absorption, accurate calculation of minor components) use THERMODYNAMICS DATA and the MAXWELL‑STEPHEN equation to calculate the local diffusion and MASS TRANSFER rate of each component. 2. Rate-based seems to require a separate LICENSE purchase.
It shouldn’t be necessary; just make the settings and that’s it!
The rate-based approach is primarily used to verify the performance of towers; it allows for the input of the structural dimensions of an existing tower, so as to evaluate it and determine the vapor-liquid load on each plate as well as other parameters.
When designing distillation columns, they can be divided into equilibrium type and rate type (2006). The former relies on the principles of vapor-liquid equilibrium for calculations, allowing for an approximate estimation of the column’s dimensions; it can thus be considered a theoretical model； The latter involves using the data from the former to conduct simulations, in order to verify once again whether the design is reasonable. However, the rate type did not exist before version 12.1; in other words, the distillation column design before version 12.1 followed the path Short cut => Equilibrium, whereas after version 2006 it follows the path Short cut => Equilibrium => Rate, with an additional verification function. I wonder if any of the seniors have any other opinions
What the people ahead said is mostly correct. As I mentioned in a previous post, there are equilibrium models and non-equilibrium models. The so-called rate-based model is a rate-control model, specifically a diffusion-rate control model; it belongs to the category of kinetic models, whereas those we used before were thermodynamic equilibrium models. This is one of the differences. Another aspect relates to the application of these differences: after performing equilibrium calculations using the equilibrium model, one can use the rate-based model for verification. This allows for calculations related to aspects such as whether flooding occurs, which involves scale-related validations. Another important point: since everyone has access to AspenONE 2006 or newer versions, I believe few of them actually purchased licenses, so everyone can also use the rate-based option. To use it, follow these steps: Tools/Options/Startup/Ratesep – just check the box in that location and it will be ready to use. As for how to use it, once you check that box and can utilize the rate-based functions, you’ll understand most of it. If you still have questions, feel free to ask here. I’ve said so much; I’m exhausted. Besides, it’s probably time for my 6 posts per hour limit today. I hope those who read this post will give me more points, so that all my efforts won’t go to waste. I have to go to work now; byebye
Thank you, up above! I understand what you mean. I’m sorry, I can’t give you extra points. I don’t have that permission. Thank you very much; wish you success in your work
I’ve learned it~,~~ When using the new version of Aspen One, I’m not sure what this option means~:P