Hi Amin,
I have never worked with the Buildings library, but I made a look to your question. I understand that you are speaking about the fluid ports port_a and port_b, that are connected to the bottom and top of the stratified storage. My first question is, Why do you want to duplicate those ports?. You can connect more than one pipe directly to them. In plus it seems possible to enter or withdrawn liquid from any of the stratified zone trough the fluPorVol port.

Regards

Carlos

Dear Carlos,

Thanks for your reply.
In our lab, we've got a hot water storage that has two inlets and two outlets. Based on your advice, (if I understood properly) we can have two water sources from one port, let's say port_a; similarly, two water sinks connected to port_b. Now, the question is that: is it possible to have these sources with different mass flowrate and temperature?
My second question is relevant to your second part of your answer (str: stratified zone). Have you given this explanation to show that the first part of your answer (procedure) would be compatible with the second part OR you just mentioned it to propose the second solution?

Appreciate your consideration.

Regards,

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Amir

What I see is that port_b, at bottom, is the expected inlet, and port_a at top is the expected outlet. You can connect to those ports as many pipes as you want. The connections to port_b should supply flow, that can be of course at different rate and temperature. The connections to port_a should take flow that can be at different rate but, of course, the flow that are taking are at the enthalpy (so also temperature) of port_a. If you need liquid at different temperature you can't take it from the top of the tank, you need to take from an intermediate level, and this seems the rol of fluPortVol port. I would think that it should be interesting for you to read some documentation regarding the use of connectors, that you can find here  and here

Regards

Carlos

Hi Carlos,

The goal of my study is to reduce numerical dissipation within the heat storage. Therefore, I have to Enhanced Stratified model which does not have FluPorVol ( please see: Buildings.Fluid.Storage.UsersGuide for detailed information) as you indicated in your last reply. Therefore, I went through the 'str model (ThirdOrderStratifier) and I noticed that there is (or theoretically should be) one inlet and one outlet for this model to have the diffusion reduced.   

Hi Amir,

As I already told you I am not used to this soft. It seems that the EnhancedStratified model introduces a better calculation of the segments temperature using a ThirdOrderStratifier submodel that contains ports. These ports are connected to the already existing ports of the main model, as you can see in the equation section of the EnhancedStratified model. They have erased the fluPorVol ports that gave access to the different segments, I supose that because of a good reason. So It seems that you have to choose between a simpler model, with the possibilitys of geting  liquid from different segments or a more sofisticated model but without this possibility. Perhaps you can try to extend the EnhancedStratified model and add the fluPorVol ports with the corresponding connections, if you are lucky it could work.

Regards

Dear Carlos,

Thanks for getting back to me!
Before reading your new reply, I was trying to build a new ThirdOrderStratifier ('str') considering two fluid streams. However, I'll try to instantiate a model from StratifiedEnhanced with FluPorVol. I hope it will be locally balanced with equal number of equations and unknowns.

Kind regards,

--
Amir