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Re: [TRNSYS-users] Simplified heating and cooling based onoperativetemperature



Title: [TRNSYS-users] Simplified heating and cooling based on operativetemperature

I once proposed to define an equation  :

 

(using the definition from Wikipedia)

 

tr         mean wall temperature; 

ta         mean air temperature 

ts         mean skin temperature

 

and link it to the building as in the attached picture.

  1. In TRNBuild, add all ‘wall temperatures’ as outputs (yields tri, for i 1 to n walls)
  2. Add an equation to compute , then T0
    Estimate  v (wind speed) and ts (skin temperature) 

 

  1. Connect the result to a controller which pilots the heating in type 56 in mode « temperature level control »

 

But I agree it would be much nicer to have a switch in type 56 allowing computing based on operative temperature.

 

I’m not at all an expert in this domain, but my expert colleagues never contested the approach J

(except for the hint that the mean surface temperatures should also be scaled depending on the surface area to be precise…).

 

Werner

 

 

De : Sabine Jansen - BK [mailto:S.C.Jansen@tudelft.nl]
Envoyé : jeudi 18 février 2010 14:51
À : Maarten Sourbron; trnsys-users@cae.wisc.edu
Objet : Re: [TRNSYS-users] Simplified heating and cooling based onoperativetemperature

 

Dear all,

 

I am also interensted in that question.

 

The only way I know now how to solve this is by using a type (controller, type 2 or thermostat, type 8) outside type 56. The the operative zone temperature must be connected to this type (e.g. 2b and creating a schedule elsewhere, in an equation solver), and the heating must be defined as a limited power connected to an input, which is then the output of the control type (type 2 or type 8).

 

One problem with this approach is that I cannot use a very large heating power anymore, since that causes the controller to switch on and off. Thus the heating power must be determined using the ideal heating, based on air temperature, first.

 

If there is an easier way, I am also very happy.

 

 

Kind regards,

 

Sabine Jansen

 


Van: Maarten Sourbron [mailto:Maarten.Sourbron@mech.kuleuven.be]
Verzonden: do 18-2-2010 13:53
Aan: trnsys-users@cae.wisc.edu
Onderwerp: [TRNSYS-users] Simplified heating and cooling based on operativetemperature

Dear all,

The simplified heating and cooling in Trnbuild is now comparing the zone
AIR temperature with the given set points.  Is there a way to change
this (or another controller model) to have the zone OPERATIVE
temperature compared with the set points?

Kind regards,

Maarten Sourbron

--
Departement Werktuigkunde-Department of Mechanical Engineering
Katholieke Universiteit Leuven
Celestijnenlaan 300A bus 2421
3001 Heverlee (Leuven)
T : 0032 (0)16 32 28 73
F : 0032 (0)16 32 29 85
E : Maarten.Sourbron@mech.kuleuven.be

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