Questions regarding Programmable Controller, Thermal Chiller integration and Energy flow diagram

The forum for all questions and discussions about Polysun Simulation Software (Designer / Standard)
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akhileshisthere
Beiträge: 1
Registriert: Mo Aug 02, 2021 9:05 pm

Di Aug 03, 2021 10:47 am

Questions:
1. How can we set the programmable controller in such a way that the CHP/Cogenerator turns ON and OFF based on electricity consumption?
2. Can we set two different controllers for one device i.e. CHP? We want to regulate the CHP based on heat demand in winter months by using Auxiliary heating controller and in summer months we want the CHP to turn ON and OFF based on electricity consumption through programmable controller? (Just selecting required months in controller setting is enough?)
3. Can we regulate the CHP working in Polysun in such a way that sometime the CHP works on its 70% capacity (for example) and when required it works on its maximum capacity?
4. How can we upload a cooling energy demand on Polysun?
5. When we set number of Fan coil as 1000 then do we need to put an input and output multiplier in the pipe which is providing the heat demand/cooling demand to the fan coil?
6. We have set the space heat demand at 3.8GWh (we did that in building settings), the CHP produces 30GWh then why the excess heat in energy flow diagram doesn’t show 26.2GWh as lost energy?
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Senkey diagram thermal.PNG
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Michael Hönes
Beiträge: 57
Registriert: Mi Jan 06, 2021 3:42 pm

Do Okt 14, 2021 12:02 pm

Thank you very much for your questions. Please find below our answers:

1)
You can find all the information in our user manual (key F1) on page 180. Here is a short summary:
You have different control modes in the programmable controller, in your case it would be mode 2. This mode must be defined in the programmable controller as output. If you need further advice how the programmable controller works you can find a detailed description on page 226 and further on.

2)
I would recommend you to use just one controller for both scenarios. You can define as many as 16 operating status. When you’re defining the different operating status, have a look at page 231. It is also recommended to use auxiliary variables which are described on the following page (232).
In the following figure 2 is an example, which you can find in the templates under “Standard templates” -> “Cogeneration/Fuel cell systems” -> “80e: Space heating (modulating power-driven cogenerator)”


3)
Yes, you can but not all CHP are modulating. The modulating CHP are marked in the catalog in the fourth column as “based on demand”. If the CHG you choose is not capable of modulating, it is necessary to define matching minimum and maximum values of the power range (I recommend you to use an already modulating CHG, which is more accurate.). Depending on the selected modulation, the model performs its calculations based on the fixed power data or interpolates between the two reference points as needed.

4)
Use the component “Hot water demand” and “Cold water demand”, but instead of using them for heating (for which these components are made) you can use them for cooling if the connections are switched. This means you can deposit an cooling energy demand profile in the component “Hot water demand”. The reason why it works is Polysuns method of operation: “Hot water demand” works as an output and “Cold water demand” as an input.
This profile must be a .csv-file which has specially delimiters ( “.” for delimiter of thousand and “,” for delimiter of decimal). For further information on importing external profiles I recommend you this video: https://www.youtube.com/watch?v=s1N-ZSSzquM

5)
No, you can simulate it with just one Fan coil, just don’t forget to adjust the heat demand/cooling demand.

6)
In your case the energy consumption of the building appears to be 30 GWh instead of the desired 3.8 GWh. Possibly the heat demand is not set correctly - please check for possible problems. The number could be entered in the wrong unit or be off by a certain factor. When using the quasi-dynamic model please make sure the energy losses are higher than the energy demand, e.g. by a factor 2.5 for a modern building (see tooltip). When you correct these settings the energy consumption should be near 3.8 GWh. Please also use the system results to verify this number.

Best regards,
Michael Hönes

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