Re: [TRNSYS-users] Heat Storage: Type 340

Hi Hassan,

Usually, type 340 is used as a water storage tank, so whenever the storage temperature goes below 0 Â°C, it's Ice, and you get a warning from type 340. You can also read the type source code; I am attaching the screenshot showing the error. This is also correct when we have only water in the tank.

However, in your simulations, you use this tank with antifreeze on the heat pump source side. Therefore it's expected that temperatures are going below 0 Â°C.

To solve this problem, you have two solutions:

Changing the source code of Type 340 (removing this warning message below 0 Â°C) and recompiling the type with a different name (maybe Type 339), only use this new complied type 339 as a source side tank.

Or you can increase the limit of the before error value in the Control card (Before ERROR value: "This value is used in the LIMITS statement to set a limit on the number of warnings before the simulation is terminated and an ERROR message is printed"), with this change, your simulations will not stop. However, I don't recommend this because if you have a warning message from any other types, the simulation will still run, and you might generate unrealistic results. But you can check in the lst file after simulations, if any other type is not giving you warnings, then this is a straightforward solution.

Best regards

Bharat

From: TRNSYS-users <> On Behalf Of Mahach, Hassan via TRNSYS-users
Sent: Dienstag, 28. Juni 2022 16:31
To: trnsys-users@lists.onebuilding.org
Cc: Mahach, Hassan <mahach@izes.de>; Rauber, Karsten <Rauber@izes.de>
Subject: [TRNSYS-users] Heat Storage: Type 340

Hi everyone,

I’m Simulating a Heat pump (TYPE 401) connected to a heat exchanger which is immersed in a heat storage (please see picture enclosed). After some time, the simulation stop because of the following error :

“water in the store is ice at I: 56 J:2 T:-0.2…”

And this could be because of the outlet temperature of the evaporator (the input to the HX immersed in the Heat storage) which may be lower than 0

I’m simulation the heat storage with Type 340, and I change the thermal properties of the fluid in the storage so I can assume that I have water mixed with antifreeze but also the same error.

My question is : is Type 340 just for water or we can we use any kind of fluid?

Have anyone an answer for this question or an idea to solve this problem?

Thank for your cooperation

Hassan

Dr. Hassan Mahach

wissenschaftlicher Mitarbeiter

Arbeitsfeld Technische Innovationen

+49 681 844 972 23

mahach@izes.de

www.izes.de

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