1. T.W.Scholten, C. de Persis, P. Tesi
Modeling and Control of Heat Networks with Storage: the Single-Producer Multiple-Consumer Case
T.W.Scholten, C. de Persis, P. Tesi

2. Outline District heating Problem description Setup Control goal Flows
Introduction
District heating
Problem description
Model
Setup
Control goal
Control
Flows
Heat injection
Case study
Conclusion
Conclusions
Future work

3. Introduction Model Control conclusion
District heating
Introduction Model Control conclusion

4. Introduction Model Control conclusion
Examples
Waste incinerators
Geothermal energy
Industrial users
Storage tank
Domestic users
Greenhouses
Introduction Model Control conclusion

5. Introduction Model Control conclusion
Problem description
Balance demand and supply
Options:
Control production
Include storage
Control demand
Dynamic pricing
Do optimization over time horizon:
Design a controller such that the stored energy converges to the desired setpoints
Introduction Model Control conclusion

6. Introduction Model Control conclusion
Setup
Heat exchangers
Stratified storage
Introduction Model Control conclusion

7. Introduction Model Control conclusion
Volume dynamics
Hot storage:
Cold storage:
Constraints both layers:
where
Introduction Model Control conclusion

8. Introduction Model Control conclusion
Temperature dynamics
Introduction Model Control conclusion

9. Introduction Model Control conclusion
Input and disturbance
Let:
where
Introduction Model Control conclusion

10. Introduction Model Control conclusion
Control goal
Find controllers and
such that:
under disturbance
Introduction Model Control conclusion

11. Introduction Model Control conclusion
Overall Model
Introduction Model Control conclusion

12. Introduction Model Control conclusion
Overall Model
Linear if and
are constant and
exists.
Introduction Model Control conclusion

13. Introduction Model Control conclusion
Controller design
1. Design flow controller
such that:
2. Design controller for the heat injection
assuming
3. Proof boundedness and stability
without assuming
Introduction Model Control conclusion

14. Introduction Model Control conclusion
1. Flow controller
Flow controller:
Volume dynamics:
exists
Recall
where
Introduction Model Control conclusion

15. Introduction Model Control conclusion
2. Heat injection
Let
Controller design
(Internal model)
Always exist!
Introduction Model Control conclusion

16. Introduction Model Control conclusion
3. Main result
The solutions of system
in closed loop with controllers
and
are bounded and
Introduction Model Control conclusion

17. Introduction Model Control conclusion
Remark
Where
No!
Need to know and a priori?
IM is robust against parameter uncertainties
Introduction Model Control conclusion

18. Case study: time varying demand
Store to 900m³
Drain to 100m³
Saturation applied
Setpoint 85°C
Extra injection
Low injection rate
Not in the analysis
Introduction Model Control conclusion

19. Case study: time varying demand
Introduction Model Control conclusion

20. Case study: time varying demand; heat exchanger
Introduction Model Control conclusion

21. Introduction Model Control conclusion
Conclusions
Model derived and control problem defined
Able to reject time varying disturbances
Global asymptotic stability proven
Some remarks:
Flow of the consumer is set constant
Simple model: easy to use, but wat about accuracy?
What about the time delays?
Introduction Model Control conclusion

22. Introduction Model Control conclusion
Future work
Extend to multiple consumers and multiple storages
Consider optimal production
Investigate possibilities of cascading
Delays
Dissipation
Include dynamic pricing
Introduction Model Control conclusion

23. Introduction Model Control conclusion
Thank you for your attention!
Questions?
Introduction Model Control conclusion