HeatX issue in Aspen (resolved)
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This post was last edited by burtgood on 2010-3-8 21:07. I want to simulate the air-water vapor heat transfer experiment using Aspen, by employing the HeatX module; however, it was found that the calculated exit temperature of the air is always higher than the value obtained from experiments. The resistance to heat transfer is mainly on the inner surface, while when performing simulations, the heat transfer area is calculated based on the outer surface area. Does this have an impact? Also, is the U correction factor in HeatX/block/Setup/U methods used to correct the heat transfer area? That is, under what conditions should this factor be used, and how to use it? Helped, but it wasn’t detailed enough. I hope someone knows; thank you so much!
The calculated air outlet temperature is always slightly higher than the experimental value, which indicates that the overall heat transfer coefficient used in the calculations is higher than the actual value. If the goal is simply to make the simulation values more accurate compared to experimental results, it is possible to use a constant U value by reducing the default value accordingly. The U correction factor is applicable in calculation and simulation scenarios, and it can be used only when membrane coefficients or the mechanical structure of the heat exchanger are specified.
This post was last edited by burtgood on 2010-3-8 21:06. Why can only one point be added? Thank you. With your explanation, I understand a bit better; if it’s just to get closer, then that’s fine. But when it comes to explaining the reasoning, that’s not possible. Also, once I select the \"Exchanger geometry\" option in the U methods, do I not need to change the U correction factor anymore? (On the condition that one can articulate the reasoning)