Type
LTDH
Short description
LTDH utilizing seawater/sewage for heating
Location
Helsinki
Country
Finland
End users
Covers 4% of the network's total heat load
Heat source
Sea water/Excess heat
Description
Five 16.8 MW HPs connected to both heating and cooling network; In winter: heat is being recovered from sewer to preheat district heating return flow from 50 °C to 62 °C , the water goes to HP, sea water is used for cooling (free cooling); Summer: heat extracted from cooling network used to raise temperature of heating network (in summer 88 °C ), surplus heat is rejected to sea water; Source temperature from 10 °C (winter) to 22 °C (summer)
Cooling
Yes
Heat source-network connection
HP (sea water and sewer); DHN and DCN connected with HP
Booster HP or no for SH
No
Booster HP, IHEU or DHSU for DHW
IHEU? (Missing info)
TES
Aquifer
Centralized/ Decentralized TES
Centralized
Category
1.8.1.1.1.
Tsource [°C]
10 (winter-sewage); 22 (summer-seawater)
Tsupply,min [°C] (network)
62 (winter)
Tsupply,max [°C] (network)
88 (summer)
Treturn [°C] (network)
45 (summer) to 50 (winter)
SCOP=(reference annual heating demand)/(seasonal electricity consumption for heating) [-]
2.96 (summer); 3.51 (winter)
Installed capacity [MW]
90.6 (summer); 83.9 (winter)
Reference 1
https://www.gshp.org.uk/pdf/DECC_Heat_Pumps_in_District_Heating_Case_studies.pdf
