[TRNSYS-users] estimating the temperature of a sensible heat storage by using the temperature of the previous timestep

[Johannes Schütz <jojo85.schuetz@googlemail.com>]

Hello Trnsys-users,

first of all I have to admit, that I'm quite new to Trnsys Studio. So the question might be really easy to answer. I would
be really glad, if you can help me. 

My problem is the following: 

I have linked a solar air collector to an equation, which is supposed to simulate the sensible storage in a very simplified way. 
I assume, that the temperature of the hot air from the collector is constant, also the volume flow and further I assume, that the 
heat transfer between the hot air and the heat storage is ideal. That means, that the air is released from the storage at storage 
temperature. Last not least I assume that there are no heat lossses to the ambience. 

Taking all the assumptions above, an estimation of the storage temperature for each timestep shouldn't be difficult.
I would propose the following formula:

The only problem I face, how to command Trnsys to use the Storage tempearture Tst from the 
previous timestep. Hopefully you can help me solving my problem. 

Thanks for your help in advance.

Take care 

Jojo