[esp-r] Re: zone control laws

[Jon Hand]

It sounds like you should be using a master/slave type of controller. This
is designed for the case where the thermostat is in a corridor and other
zones are slaved to the logic that the passage way demands.  There is
an example model for master slave in the exemplars area.

-Jon Hand
________________________________________
From: esp-r-bounces at lists.strath.ac.uk [esp-r-bounces at lists.strath.ac.uk] On Behalf Of Lukas Swan (Dal) [lswan at dal.ca]
Sent: 28 January 2009 16:46
To: esp-r at strath.ac.uk
Subject: [esp-r]  zone control laws

Hello
I am having difficulty understanding the idealized zone control law response of a ‘Fixed heat injection’ and ‘Multi-stage control with hysteresis’ when applied to my model.


1)      They appear to frequently use ½ the defined fixed capacity and only under certain circumstances use the full capacity

2)      The temperature differential is not set in the ‘fixed’ version, but appears to apply full capacity or half capacity depending on temperature difference above setpoint, but also exhibits some PID response.

3)      ‘Multi’ also exhibits some interesting things.

In addition, if the sensor is in one zone (e.g. main) and the actuator is air point of two zones (e.g. main and bsmt) there is very odd response of which gets heat injection, including the potential to be 150% of specified capacity.

My building time step is 10/hr. I am simply trying to model a typical deadband thermostat in the main zone that controls a idealized plant that has fixed ON capacity and injects heat to the main and basement zones (preferably 60%/40% heat rate distribution to the zone of the fixed capacity).

Thoughts?

Lukas Swan
Dalhousie Univ.
Canada