[esp-r] Re: Control of air volume

[Jon Hand]

Look in the exemplar models which implement mass flow control.  The
ON/OFF control will test a condition and decide whether flow is applicable
at that timestep.  It then multiplies the nominal capacity of the component by
the fraction-of-capacity applicable at that timestep to get the flow rate to use.

Thus - a fraction capacity of zero should result in zero flow for ON as well as OFF
state.  I would expect you to use a fraction-of-capacity of 1.0 if you want the
ON condition to result in the nominal flow rate.  If the fraction-of-capacity was
0.5 then an ON state should result in half the nominal flow rate of the component.

This is what is used with constant volume flow components. It should also
apply to constant mass flow components.

-Jon Hand
________________________________________
From: esp-r-bounces at lists.strath.ac.uk [esp-r-bounces at lists.strath.ac.uk] On Behalf Of wakana-m at ec.hokudai.ac.jp [wakana-m at ec.hokudai.ac.jp]
Sent: 31 October 2012 05:17
To: esp-r at lists.strath.ac.uk
Subject: [esp-r] Re: Control of air volume

Dear Jon and everyone,

 Thank you for your prompt response.
 Now I use constant mass flow component in air flow network.
 And I also use ON/OFF control of air flow and input the fraction of
capacity in air flow control.
 However the air volume value of results isn't changed.

 For example, If I input that constant mass flow is 0.5 kg/s component
and use ON/OFF control (fraction of capacity is 0), the flow keeps 0.5kg
/s, not changed.
 In this case, I think that the mass will be half when the flow is ON.

 Would it impossible to use both of constant mass flow component and
fraction of capacity in ON/OFF control?

 Best regards,

 Wakana Matsumoto

----- Original Message -----
>
> You can apply control to a volume flow component or a mass flow
> component.  This is especially useful in early design assessments
> where a volume flow component is being used to represent a
> future detailed fan component.  There are a number of examples
> of controlling volume flow rates in the training folders.  This is
> also discussed in the ESP-r Cookbook (recently updated in the
> ESRU web site).
>
> -Jon Hand
> ________________________________________
> From: esp-r-bounces at lists.strath.ac.uk [esp-r-bounces at lists.strath.ac.
uk] On Behalf Of wakana-m at ec.hokudai.ac.jp [wakana-m at ec.hokudai.ac.jp]
> Sent: 29 October 2012 23:24
> To: esp-r at lists.strath.ac.uk
> Subject: [esp-r] Re: Control of air volume
>
> Dear Achim and everyone,
>
>  Thank you for your response.
>
>  As you said, I'm using an air flow network and an air flow network
> control.
>  I chose on/off control method in my model.
>  In on/off control, we should input a setpoint, action and fraction.
>  I think fraction means effective opening areas.
>  Is it possible to control air flow based on air volume instead of
> effective opening areas?
>
>  Best regards,
>
>  Wakana Matsumoto
>
> ----- Original Message -----
> > Dear Wakana Matsumoto
> >
> > could you please elaborate on what you mean with "air flow module"?
> Did you add a flow network? If yes, and if the ventilation is to be "
> natural", then you will likely want to control an opening? E.g. open
or
> close a window? There are several possible approaches to this. If you
> really do want to have "hourly" changes (when using an air flow
network,
> time steps of an hour may lead to problems), the best approach may be
> using a TDF file. The alternative is to set up a standard "air flow
> network control" via ProjectManager. This is a very similar procedure
to
> setting up (thermal) zone control.
> >
> > Best
> > Achim
> >
> >
> > On Oct 22, 2012, at 9:02 AM, wakana-m at ec.hokudai.ac.jp wrote:
> >
> > > Dear all,
> > >
> > > Hello.
> > > I'm using ESP-r system now.
> > > The air flow module for natural ventilation is included in my
model .
> > > Now I would like to change the fluid flow volume on an hourly
basis.
> > > So, when the air moves from a node to another node can I control
its
> > > flow volume ?
> > >
> > > Best regards,
> > >
> > > Wakana Matsumoto
> > >
> > >
> > >
> > >
> > > _______________________________________________
> > > esp-r mailing list
> > > esp-r at lists.strath.ac.uk
> > > http://lists.strath.ac.uk/mailman/listinfo/esp-r
> > >
> >
> > achim.geissler at intergga.ch
> >
> >
> >
> >
> >
> > _______________________________________________
> > esp-r mailing list
> > esp-r at lists.strath.ac.uk
> > http://lists.strath.ac.uk/mailman/listinfo/esp-r
> >
>
>
>
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