Re: [TRNSYS-users] building model for a cold load simulation

[瞳瞳 <ilyt2000@gmail.com>]

Dear Jochen,

Danke für Deine Antwort. 

I have tried to do  what you told me, and i got the right pictures . But i found something very strange.
1.  The simulation of the whole July is not the same like just the 23. July ,  and there is  a very big difference. Still i don't know why.  
2.  I have tried to caculate the cold load with vdi 2078 in excel, there is also a very big difference . I think maybe it's because of the gains in TRNBUILD. i want 2 persons, 2 computers and a light with 100W.  So i made the gains just like what the picture shows. 

Can anyone help me?

Thanks and best regards,

Leona

2011/8/8 Jochen Doell <jochen.doell@ise.fraunhofer.de>

Dear Leona,

you can do just one thing at a time: Simulate the free floating room temperatures when no heat/cold is supplied OR simulate the cold/heat demand when the room is kept at certain temperature.

What you did is a simulation without a heating/cooling system, so you got the temperature profile.

You need to turn on the aux cooling system in TRNBUILD (assuming you use type 56) and give the building a desired maximum temperature (constant value, input or schedule). When the room temperature reaches the maximum temperature, you cooling system will start to operate, keeping the room below the temperature. Q_sens is the (negative) cooling demand.

Best regards,
Jochen

Am 20:59, schrieb ͫͫ:

Dear all,

i want to make a building model for the simulation of cold load.It is just
one room with one external wall and 2 unair-conditioned next rooms(one is
the lobby the other is the upper room).

Questions are
1. I tried to run the simulation, but the cold load is always 0, like the
picture in the mail.
2. i think the temp. is also not correct ,but i don't know why.  ps. i just
want to simulate the temp.and the cold load in 23. July in the zone.

Can anyone help me?

Thanks and best regards,

Leona

--
_________________________________________________

Dipl.-Ing. (FH) Jochen Döll
Division Thermal Systems and Buildings

Fraunhofer-Institut für Solare Energiesysteme ISE
Heidenhofstrasse 2, 79110 Freiburg, Germany

Phone: +49 (761) 4588-5468 Fax: +49 (761) 4588-9000
jochen.doell@ise.fraunhofer.de
www.ise.fraunhofer.de
_________________________________________________

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