Dear Héloïse,
If you want to use the
ideal heating and cooling option of type56, you can change the set point at
wich you want to heat or cool.
e.g. if you want to start
heating at T_op=T_set=20°C, determine an input to type56 being T_corrected =
2*Tset-Tmsurf, with Tset = 20 and Tmsurf the mean surface temp which type56
gives as an output.
It comes from T_operative
= (T_air+T_mean_surf)/2, or with the symbols of above T_set =
(T_corrected+Tmsurf)/2.
So, instead of supplying
the required operative temperature T_set as input, you supply the equivalent
air temperature, so with T_corrected as air temp and Tmsurf as surface temp you
end up with an operative temp = T_set.
Works fine, with no
numerical issues, only a small oscillation around T_set, but with a small
enough time step, this is neglectable.
Good luck,
Maarten
--
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
From: David BRADLEY
[mailto:d.bradley@tess-inc.com]
Sent: maandag 8 november 2010
20:48
To: Heloise PELEN
Cc: trnsys-users@engr.wisc.edu
Subject: Re: [TRNSYS-users] Top
control in the Type 56
Heloise,
If you are using the automatic heating and cooling types that are built
into Type56/TRNBuild then these only pay attention to the zone air temperature
in order to compute the sensible load on the space. The control of those
components is assumed to be instantaneous and ideal. If you are simulating a
building and an actual HVAC system then you can set up the HVAC system to pay
attention to whatever Type56 output variables that you want (including
operative temperature). PID control is possible using Type22 but in my
experience a lot of portions of the HVAC system are based on ON/OFF control
(Type108). When implementing controls of any kind you need to make sure that
your timesteps are small (1 to 5 minutes); recall that TRNSYS can make one
control decision per timestep and then it must stick with that decision until
the next timestep.
Regards,
David
On 11/8/2010 10:25, Heloise PELEN wrote:
Dear TRNSYS users,
The Type 56 uses a control on the
air temperature « TAIR » to compute the sensible heat demand of each
thermal zones.
This temperature does not include
the surface temperature and doesn’t fully describe the temperature
actually felt by the human, body.
Is there a way to control the
operative temperature, rather than on the air temperature, in type 56 ?
I thought about using Type 22 but the
simulation seems rather unstable with more than on Type 22, and I would like to
be able to control the operative temperature in each thermal zones.
Thanks for your help !
Best regards,
Héloïse Pelen
ETAMINE
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Visitez notre site web : www.etamine.coop !
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-- ***************************David BRADLEYPrincipalThermal Energy Systems Specialists, LLC22 North Carroll Street - suite 370Madison, WI 53703 USA P:+1.608.274.2577F:+1.608.278.1475d.bradley@tess-inc.com http://www.tess-inc.comhttp://www.trnsys.com