Model developed from performance curves are dynamic models?

[Nikhil N]

I am trying to model a real heat exchanger in simulink. I don't have the geometry data. But I have UA curve with me. If I have developed the model with UA curve, will it be dynamic in nature?

 

[BvU]

Nope.

 

[Nikhil N]

Nope.

Do you think, is it because the test data gives the details of only at steady state ?

 

[BvU]

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 ?

 

[Chestermiller]

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 ?

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.

 

[Nikhil N]

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]

complete simulink model for rotory air compressor

Like in this picture by Brian S. Elliott - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=66663474 ?

There is a cooler on the left and one on the right. Both ? In simulink ?