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[TRNSYS-users] the total heating demand calculation by TRNSYS and by hand



Dear all,
 
 I assumed that the initial indoor temperature is 20°C and maintains the
same value during 24 hours, the outdoor temperature is 0°C and stable
also  during 24 hours. It exists no cracks and infiltration and
ventilation.

   Conditions of the big test room: Volume of the big room: 100 m3, Density of
the air at 20°C: 1.205 kg/m3, Indoor air temperature of the big room:
20°C, Outdoor temperature: 0°C, Specific heat capacity of air at 20°C:
1.004 kJ/kg*k.

   Do you mean let me calculate the total heating demand. I think it
includes two parts: first one is the heating which maintains 20°C,
second is the heating which compensate the heat loss resulted from the
heat transfer. The heat loss includes the heat transfer through the
walls and floor and roof. (In other words, only one part: the second
one) I think the main type of heat transfer is the heat conduction.

   I used the software output "QHEAT" and "INTEGRATOR" to calculate the
total heating demand one day, the heating is radiator, the max. power
is 1.1 kW(the big room's actual heating power), the result is 34314.2
kJ, and I asked the technical support, he said QHEAT is the total
heating demand. But I calculated by hand, only the heat loss through
the walls and roof and floor is 80000 kJ.

  After thinking and analysis, I think the problem maybe is that I assumed
the initial indoor temperature as 20°C, it means the walls and roof and
floor can store lots of thermal energy. So the result of software:
34314.2 kJ is smaller than 80000 kJ. Because the thermal energy the
walls and roof and floor can store should be bigger than 80000 kJ or
next to it. How to calculate the heat loss through the wall and roof and floor using TRNSYS?

  Another problem is that I used the software's air-conditioning to
calculate the total heating energy, the result is 12707.7 kJ which is
smaller than the raditor. So I think the technical support and manual
said the total heating energy only is the energy which heats the indoor
air, not calculating or considering the storing thermal energy of the
walls etc. Am I right or not? Please explain the reasons!

  These days I will make sure the software is how to calculate the heat
loss through the walls etc. and how much thermal energy the walls store.
And I think the TRNSYS should be not wrong or not?
 
  PLEASE tell me why the heating energy's difference by TRNSYS and by hand is so big- about 50000 kJ?
 
  Many thanks!
 
  Br.
 
wang
 
 
 

2011/1/14 <trnsys-users-request@cae.wisc.edu>
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Today's Topics:

  1. Equation tool (Rambod Rayegan)
  2. TRNSYS Manual (Rambod Rayegan)
  3. Re: Equation tool (Mehdi Shahrestani)
  4. Re: TRNSYS Manual (Matt Duffy)
  5. Re: TRNSYS Manual (Mehdi Shahrestani)


---------- 已转发邮件 ----------
From: Rambod Rayegan <rraye001@fiu.edu>
To: trnsys-users@cae.wisc.edu
Date: Fri, 14 Jan 2011 14:19:11 -0500
Subject: [TRNSYS-users] Equation tool
Dear TRNSYS users,
 
I don't know  how can I find the function of each botton (like GT, LT, LE, AE, NE, STEP,  ...) in the equation tool of the TRNSYS.
Is there any file or section in the TRNSYS documentation files that explain equation tool functions?
 
Thank you,
 
Rambod



---------- 已转发邮件 ----------
From: Rambod Rayegan <rraye001@fiu.edu>
To: trnsys-users@cae.wisc.edu
Date: Fri, 14 Jan 2011 14:24:18 -0500
Subject: [TRNSYS-users] TRNSYS Manual

Dear TRNSYS users,
 
Is ther any file named" TRNSYS Manual " in your documents after installing the software.?
It seems sometime in some documents the author refers to TRNSYS Manual. I have not such a document in my documenation folder.
 
Thank you,
 
Rambod


---------- 已转发邮件 ----------
From: "Mehdi Shahrestani" <mahdishahrestani@yahoo.com>
To: "'Rambod Rayegan'" <rraye001@fiu.edu>
Date: Fri, 14 Jan 2011 19:30:58 -0000
Subject: Re: [TRNSYS-users] Equation tool

Dear Rambod

 

Just go to Trnsys manual volume 6 page 25.

You can find all of them in that page. Moreover, you can find them as a FORTRAN functions in each FORTRAN book.

Anyway, if you do not have that page let me know I am online tonight.

 

Nice to hearing you

Mehdi

 


From: trnsys-users-bounces@cae.wisc.edu [mailto:trnsys-users-bounces@cae.wisc.edu] On Behalf Of Rambod Rayegan
Sent: 14 January 2011 19:19
To: trnsys-users@cae.wisc.edu
Subject: [TRNSYS-users] Equation tool

 

Dear TRNSYS users,

 

I don't know  how can I find the function of each botton (like GT, LT, LE, AE, NE, STEP,  ...) in the equation tool of the TRNSYS.

Is there any file or section in the TRNSYS documentation files that explain equation tool functions?

 

Thank you,

 

Rambod



---------- 已转发邮件 ----------
From: "Matt Duffy" <duffy@tess-inc.com>
To: "Rambod Rayegan" <rraye001@fiu.edu>, trnsys-users@cae.wisc.edu
Date: Fri, 14 Jan 2011 13:38:12 -0600 (CST)
Subject: Re: [TRNSYS-users] TRNSYS Manual

Rambod,

Simply hit the "F1" button to open the documentation main menu, or you can click on the "?" icon in the Studio. You can manually go to the documentaiton folder as well, ".\Documentation".

The section about the logical functions is in the TRNEdit manual - Volume 6 - section 6.3.9.1.

Best regards,

Mat Duffy

----- Original Message -----
From: "Rambod Rayegan" <rraye001@fiu.edu>
Sent: Fri, January 14, 2011 13:24
Subject: [TRNSYS-users] TRNSYS Manual


Dear TRNSYS users,
 
Is ther any file named" TRNSYS Manual &qu! ot; in your documents after installing the software.?
It seems sometime in some documents the author refers to TRNSYS Manual. I have not such a document in my documenation folder.
 
Thank you,
 
Rambod
 

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---------- 已转发邮件 ----------
From: "Mehdi Shahrestani" <mahdishahrestani@yahoo.com>
To: "'Rambod Rayegan'" <rraye001@fiu.edu>
Date: Fri, 14 Jan 2011 19:40:09 -0000
Subject: Re: [TRNSYS-users] TRNSYS Manual

Rambod

 

At the top of your TRNSYS screen after “windows” there is a icon with this sign “?” .

If you go through that, manuals are there.

 

Hope it helps

Mehdi

 


From: trnsys-users-bounces@cae.wisc.edu [mailto:trnsys-users-bounces@cae.wisc.edu] On Behalf Of Rambod Rayegan
Sent: 14 January 2011 19:24
To: trnsys-users@cae.wisc.edu
Subject: [TRNSYS-users] TRNSYS Manual

 


Dear TRNSYS users,

 

Is ther any file named" TRNSYS Manual " in your documents after installing the software.?

It seems sometime in some documents the author refers to TRNSYS Manual. I have not such a document in my documenation folder.

 

Thank you,

 

Rambod


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