District heating networks consist of collective heat distribution systems, the heat being supplied as steam or hot water by one or more production plants. The fluid is transported by pre-insulated pipes (distribution network) serving the buildings equipped with delivery stations (steam / water exchange stations or sub-stations). The steam or hot water gives up its heat to the building facilities.
A district heating network operates in closed circuit. It therefore always consists of at least two pipes:
- one to transport the heat transfer fluid to users,
- the other to return the fluid to the production plants.
The district heating network therefore requires three basic components:
- the heat sources to produce heat,
- the distribution network,
- the steam / water exchange stations or sub-stations in the buildings.
The distribution networks transport heat at different temperatures and pressures. They are classified into two categories:
- Primary networks (long distance transport)
- Secondary networks (distribution after exchange sub-station)
Depending on their category, they can transport water at:
- very low temperature,
- low temperature,
- high temperature,
- or as steam,
- or superheated water.
Inpal © 2011.