[esp-r] Re: Mixing plant and ideal zone controls

[Jon Hand]

The normal response would be that it is not possible to associate a zone control and
a plant control with the same zone because the two could fight each other during the
solution process.  We normally assume that the plant is doing it all rather than
sharing the task.

A work around would for smaller models might be to create an extra zone
to deliver the plant ventilation to and then use a flow network to push/exchange that
air into the real zone which has a zone control set to 20C.

The other approach would be to not use explicit plant components and implement
a rough equivalent of the plant components as zone controls in the extra zone and
then use an air flow network to get the result of the abstract components via-a-zone
into your real zone.

Whether you can abstractly represent the system depends on what kind of heat
recovery is being used in the building, but it is often possible to use a combination
of flow components to capture the essential characteristics of ventilation and
heat recovery.

-Jon Hand
________________________________________
From: esp-r-bounces at lists.strath.ac.uk [esp-r-bounces at lists.strath.ac.uk] On Behalf Of Christian Anker Hviid [cah at byg.dtu.dk]
Sent: 26 October 2009 22:15
To: esp-r at lists.strath.ac.uk
Subject: [esp-r]  Mixing plant and ideal zone controls

A question about plant and ideal zone control that I hope someone has a solution for.

I have one zone ventilated by a plant with and without heat recovery. I think I need to link the plant to the zone before the effect of the heat recovery shows in the energy delivered.
But I also need to specify a zone control that keeps the zone temperature at 20degC. I know I can put in a heating coil into the plant and control it to approximately 20degC, but for the sake of simplicity (in larger scale models) I just want to control my room temperature ideally. How do I link a plant and an ideal zone control to the same zone?
I think the same problem arises if I want to link an air based and a water based plant to the same zone?







Best regards

Christian Anker Hviid
Industrial PhD candidate

DTU Byg
Technical University of Denmark
Brovej, building 118
DK-2800 Lyngby
Phone DTU: +45 4525 1886
Phone Alectia: +45 8819 1365
Mail: cah at byg.dtu.dk

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