1. District heating system modeling
Marta Rós Karlsdóttir
Reykjavík
Faculty of Engineering - University of Iceland

2. Faculty of Engineering - University of Iceland
The case study
127 m2 appartment in a double family housing
Located in Reykjavík at new suburb in the eastern part of town (Norðlingaholt)
New concrete building, well insulated
Heat capacity 86.4 MJ/°C
Time constant hours
Heat load factor kW/°C
Base temperature Tb -3.8 °C
Maximum mass flow kg/s
Cost 5,363 IKR/month average
Temperature data
Reykjavík1949 – 1990
Minimum temperature °C
Degree days below 0°C and Tb
Faculty of Engineering - University of Iceland

3. Distinctiveness of the district heating systems in Iceland
The water is used directly from low temperature areas
Hot water production by heating up fresh water in CHP
Chemical composition of water
For house heating and as hot tap water
Mainly “Once through” systems

4. Space heating in Iceland by sources0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
1970
1975
1980
1985
1990
1995
2000
Fossil fuels
Electricity
Geothermal 9%
<1%
Fossil fuels is used in icolated places

5. Use of Geothermal Energy
District heating services
Power plants
Industry
Greenhouses
Swimming pools
Fish farming

6. Steady state modelling
Faculty of Engineering - University of Iceland

7. Steady state modelling
Faculty of Engineering - University of Iceland

8. Dynamic modelling Challanges in project work
Faculty of Engineering - University of Iceland

9. Faculty of Engineering - University of Iceland
Dynamic modelling
Longest cold spell
System design
Faculty of Engineering - University of Iceland

10. Faculty of Engineering - University of Iceland
Conclusions
Well insulated houses reduce the heat load on the system
Transmission network
Mass flow has positive effect
Outdoor temperatures have negative effect
Not immediate response between indoor and outdoor temperature due to building heat capacity
Faculty of Engineering - University of Iceland

11. Faculty of Engineering - University of Iceland