[TRNSYS-users] Control of Type 927 Water-Water heat pump

[David BRADLEY]

Mattias,
   The tools you need are definitely there! first off, yes, there are 
two components that can store the value of an input and keep it for one 
or more time steps before "releasing" it. Utility: Input Value Recall: 
Type93 and Controllers Library (TESS): Delayed Inputs: Type661)

   Second, you may already have noted that some of the TESS HVAC Library 
heat pump components allow you to specify that there is more than one 
identical heat pump in parallel among the parameters and to control how 
many of them are currently on among the inputs. Type927 is one of these.

   I would recommend that you look at the components available in the 
TESS Controllers library; you may find a staged controller in that 
library that does what you want without having to write your own 
controller model.
kind regards,
  David


On 4/10/2015 9:02 AM, Mattias Ericsson wrote:
>
> Dear TRNSYS users!
>
> I am running a Type 927 water-water heat pump with a borehole field as 
> source. The heat pump heats a storage tank which in turn supplies 
> several secondary heating systems.
>
> Now I want to model 4 identical heat pumps and determine the number of 
> heat pumps on depending on the return temperature from the storage 
> tank to the heat pump. If the temperature is below a certain set point 
> I want to start another heat pump and if the temperature is too high I 
> want to switch one off.
>
> I tried to write a short code in the w-interpreter but my problem is 
> that the heat pump component can’t tell another component how many 
> heat pumps that are already running. Therefore the option “start one 
> more heat pump”  is not available. Is it possible to let another 
> component store the input variable to Type 927 so it can be available 
> in the next time step? Or do anyone have any idea on how to achieve 
> what I want to do?
>
> Best regards
>
> /Mattias Ericsson/
>
> //
>
>
>
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-- 
***************************
David BRADLEY
Principal
Thermal Energy Systems Specialists, LLC
22 North Carroll Street - suite 370
Madison, WI  53703 USA

P:+1.608.274.2577
F:+1.608.278.1475
d.bradley at tess-inc.com

http://www.tess-inc.com
http://www.trnsys.com

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