Page 40 - European Energy Innovation - Winter 2014
P. 40
Winter 2014 European Energy Innovation


District Heating in Finland

By Kari Sipilä, Principal Scientist, VTT, Finland

DISTRICT HEATING IN THE EU Nowadays approximately half of with operational units and all
District heating started in Europe the building stock is connected necessary components and
at the beginning of the 19th to district heating. In the largest functions. Boiler plants are gas,
century. Consumption in the EU27 cities the proportion is more than oil or biomass fuel fired. Burnable
countries together with the three 90 %. More than 75 % of district community waste is also used.
accession countries is about 1.7 heating is produced by combined The maximum temperature
EJ/a (472 TWh/a), which is about heat and power (CHP) plants. can be selected between
10 % of the total heating demand. 90 - 120 °C. Three-pass shell
More than 100 million people live DISTRICT HEATING SYSTEM boilers are the most used boiler
in district heated houses in the CHP production units are configuration. This reliable and
EU. The world’s district heating connected through a heat popular technology achieves a
load is about 10 times that of exchanger to the DH-network. thermal efficiency of 90 % without
Europe, and so is about the same Heat only boilers are connected economisers.Water treatment
as the total heating demand for directly to the network while and high quality control ensure
the whole of the EU. The total consumers are linked to network boiler plant reliability and a long
length of the district heating substations . In this way the service life for the pipelines and
pipeline is 155 000 km in EU and oxygen content of the district auxiliaries.
more than 400 000 km in the heating water as well as the
world or about 10 times round pressure variation can be kept A DH-pipeline is a closed
the globe. under control. For buildings the 2-pipeline system in which has
hot tap water is heated in a heat the water flow is regulated by
DISTRICT HEATING IN FINLAND exchanger. pumps. The network is mostly
District heating started in located underground, while in
the Helsinki city region at Boiler plants are delivered some cases, for special reasons,
the beginning of the 1950s. to the network complete an above ground site is required.
Water is the medium, because
it is cheap, easy to handle and
not corrosive or toxic. Supply
temperature of outgoing water
varies between 75 – 120 °C and is
cooled down to 40 – 70 °C by the
consumers. The representative
planning pressure is 1.0 – 1.6
Mpa in the pipeline. Regional low
heating networks can work in the
temperatures of 60 – 70 °C.

The pipes can be separated or
insulated in the same lining.
Industrially produced pipe
elements, made of steel or plastic,
are insulated in rigid foam and
plastic lining. The necessary
water flow in the district heating
network is created by pressure
generated by circulation pumps
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