[esp-r] Re: Plant component ideal control

[Achim Geissler]

Dear Dimitrios,

what you describe should be possible with plant controllers, if I understood correctly. The following

* Control loops   12
# senses dry bulb temperature in sf_bed2.
   15    0    0    0    0  # sensor 
# plant component  74:pu_sf_bed2 @ node no.  1
   -1   74    1    0  # actuator 
    1  # all daytypes
    1  365  # valid Tue-01-Jan - Tue-31-Dec
     5  # No. of periods in day: weekdays    
   14    0   0.000  # ctl type, law (period off), start @
      0.  # No. of data items
    0    8  11.000  # ctl type, law (On-Off control.), start @
      7.  # No. of data items
  1.00000 25.50000 26.50000 0.00800 0.00000 4.00000 0.50000
   14    0  14.000  # ctl type, law (period off), start @
      0.  # No. of data items
    0    8  16.000  # ctl type, law (On-Off control.), start @
      7.  # No. of data items
  1.00000 25.50000 26.50000 0.00800 0.00000 4.00000 0.50000
   14    0  20.000  # ctl type, law (period off), start @
      0.  # No. of data items

takes a zone temperature and activates a plant pump (zone 15, plant component number 74, in this case). And this

* Control loops   13
# senses var in compt.  1:theTank @ node no.  1
   -1    1    1    0    0  # sensor 
# plant component   2:theBoiler @ node no.  1
   -1    2    1    0  # actuator 
    1  # all daytypes
    1  365  # valid Tue-01-Jan - Tue-31-Dec
     1  # No. of periods in day: weekdays    
    0    8   0.000  # ctl type, law (On-Off control.), start @
      7.  # No. of data items
  1.00000 38.00000 40.00000 8900.00000 0.00000 0.00000 0.00000

senses a temperature in a plant component (tank) and activates a boiler with 8.9 kW heating capacity (and tries to keep node 1 of the tank between 38 and 40 degC). To get closer to "ideal", you can give the boiler "limitless" power. The controllers are, of course, "on-off", so not really ideal.

I don't know the names of these controllers in the prj menus, though. Maybe the above can help to get some ideas, nonetheless.

Best
Achim


On Dec 3, 2013, at 6:43 PM, Dimitrios Sfakianakis <dimitrios.sfakianakis at strath.ac.uk> wrote:

> Dear List,
> 
> I am currently modelling an HVAC system with air re-circulation using explicit plant component modelling. The system is comprised by the basic components: mixing box, cooler, heater, fan and ducts. At a first stage I am not concerned with modelling the actual control system for the heater and cooler (a PID controller) and want to use an ideal controller much like the BLC01 ideal controller in  /esrubld/bcfunc.F in order to calculate the power demand of the components.
> 
> After going through the available control methodologies for plant components I did not find any controls types that resemble the BLC01. I have tried representing the heater with a thermal zone with an ideal control, connected to the plant network however I notice that if 2 controls are imposed in the same zone, only the second one works.
> 
> Is there a plant component controller that can keep the temperature of a component at a certain set point by sensing temperature, activating flux and utilising the required amount of energy? If not what would be the best way to model this in Esp-r?
> 
> Thank you for your time.
> 
> Kind regards,
> 
> Dimitrios Sfakianakis MEng
> Research Assistant, Dept. Naval Architecture and Marine Engineering, University of Strathclyde
> Kelvin Hydrodynamics Laboratory, Acre Road, Glasgow, G20 0TL
> T: +44 (0) 141 330 2648 (Ext 2648)
> M: +44 07514271592
> E: dimitrios.sfakianakis at strath.ac.uk
> The University of Strathclyde is a charitable body, registered in Scotland, with registration number SC015263.
> 
> 
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achim.geissler at intergga.ch