Yep, we have a big distric heating system here in Brno, Czech Republic - in operation since 1930, with 110 000 housholds & most big public and commercial buildings connected. It started as coal fired, but the modern system combines natural gas cogeneration (gas turbine -> steam turbine -> district heat) and waste incineration (that also includes a steam turbine to make some electricity). In the summer the waste incinerator provides all the necessary heat for the system alone. :)
Eventually the city would like to make the system stop using natural gas, so there is a wood waste burning plant comming online at the end of this year & hot water pipeline is being built from the nearby Dukovany power plant. This two together should make the system natural gas indepedent in the future. :)
While it started as steam based system & powered most of then very important textile industry, steam also has issues. Old pipes loose quite a bit of heat on the way (there used to be evergreen meadows even in winter in places above the old steam pipes), the pipes flex quite a bit when heating up/cooling, so they need to be placed on rollers in underground channels with U shaped sections to account for the pipe stretching/contracting. The steam also condenses & you need to get rid of that condensate on the way. And while unlikely, it is possible for a steam pipe to burst/explode, which is very dangerous for any bystanders.
For these reasons & because the textile industry being much less important, the Brno district heating system is being converted to hot water distribution, which is quite a bit more effcient apparently. Reportedly, with modern insulated pipes, the heat loss on the way is negligeable, the pipes can be placed directly in the ground & they form a closed loop - no more mucking with rollers, condensante or explosions.
So in a few years, the often seen steam ventilation pipes (from the various steam related texhnical spaces) around the city will be a thing of the past. :)
Eventually the city would like to make the system stop using natural gas, so there is a wood waste burning plant comming online at the end of this year & hot water pipeline is being built from the nearby Dukovany power plant. This two together should make the system natural gas indepedent in the future. :)
While it started as steam based system & powered most of then very important textile industry, steam also has issues. Old pipes loose quite a bit of heat on the way (there used to be evergreen meadows even in winter in places above the old steam pipes), the pipes flex quite a bit when heating up/cooling, so they need to be placed on rollers in underground channels with U shaped sections to account for the pipe stretching/contracting. The steam also condenses & you need to get rid of that condensate on the way. And while unlikely, it is possible for a steam pipe to burst/explode, which is very dangerous for any bystanders.
For these reasons & because the textile industry being much less important, the Brno district heating system is being converted to hot water distribution, which is quite a bit more effcient apparently. Reportedly, with modern insulated pipes, the heat loss on the way is negligeable, the pipes can be placed directly in the ground & they form a closed loop - no more mucking with rollers, condensante or explosions.
So in a few years, the often seen steam ventilation pipes (from the various steam related texhnical spaces) around the city will be a thing of the past. :)