The discussion revolves around the modeling of a heat exchanger in Simulink using UA curves, specifically questioning whether such a model can be considered dynamic in nature. The scope includes theoretical modeling and practical application within a larger system, such as a rotary air compressor.
There is disagreement among participants regarding whether the UA curve-based model can be considered dynamic. Some participants assert it cannot, while others suggest it might be a reasonable approximation under certain conditions. The discussion remains unresolved regarding the model's dynamic nature.
The discussion highlights the limitations of using UA curves, particularly the dependence on steady-state data and the potential implications for dynamic modeling. There is also an emphasis on the need for more specific application details from the OP.
Do you think, is it because the test data gives the details of only at steady state ?BvU said:Nope.
I agree. I think we need to hear more details. But it might be a decent approximation if UA where used in a dynamic case based on the instantaneous conditions. It depends.BvU said:I do. UA is an instantaneous value, a curve makes it a function of something.
On the other hand, dynamics of heat exchangers aren't often a focus (except perhaps in textbooks): I've always seen them treated as instantaneously reacting devices because the heat content of vessels, columns and reactors and such was so much greater. Do you have a particular application in mind ?
@Chestermiller : any experience ? -- and shouldn't we let the OP add some more context ?
My end objective is to make complete simulink model for rotory air compressor. So this heat exchanger will become one of the subsystem in my model. Can you tell me, if I am using a heat exchanger modeled with this approach can mimic the actual system functionality?BvU said:I do. UA is an instantaneous value, a curve makes it a function of something.
On the other hand, dynamics of heat exchangers aren't often a focus (except perhaps in textbooks): I've always seen them treated as instantaneously reacting devices because the heat content of vessels, columns and reactors and such was so much greater. Do you have a particular application in mind ?
@Chestermiller : any experience ? -- and shouldn't we let the OP add some more context ?
Like in this picture by Brian S. Elliott - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=66663474 ?Nikhil N said:complete simulink model for rotory air compressor