Heating network

from Wikipedia, the free encyclopedia

A heating network is a device for the line-based supply of thermal energy in which a heat transfer medium transports the heat from a heat source to a heat sink. The medium can give off sensible heat - as in hot water networks - or latent heat through a phase transition - as in steam networks - and then absorb it again.

A cooling network is a special form of heating network with the opposite direction of energy flow: heat flows from many points to a central point where a cooling machine is installed. As a rule, water that is colder than the ambient temperature is used to extract heat locally for air conditioning and cooling purposes.

Heating networks can extend over several kilometers or only cover a few neighboring properties. Within buildings, too, heating networks are used to distribute the heat from the heating system to heated rooms. Heating networks are characterized by the maximum permissible temperature and the maximum pressure. The efficiency of heating networks is not only determined by the mass flow of the carrier medium, but also by the temperature difference between the flow and return.

Technically, the heat pipes differ according to their installation effort and structure:

  1. In the early days of district heating, hooded ducts were often installed in which steel pipes were wrapped with insulation on site.
  2. Plastic casing pipes are prefabricated steel pipes with insulation made of PUR foam and an outer skin made of plastic, which can be laid directly in the ground.
  3. Plastic pipes are characterized by lower costs, but due to the aging processes (see plasticizers ) they are dependent on comparatively low flow temperatures.

The laying of heat pipes is less influenced by the purchase costs for the pipes, but mainly by the costs of civil engineering work, which can be very expensive, especially in inner-city areas.

The demarcation between district and local heating networks is fluid. In district heating networks there are transport routes with partly increased pressure and temperature values ​​and a hydraulic separation to downstream distribution network levels. Local heating networks, on the other hand, can be designed for low temperatures, as you are dealing with a manageable number of heat consumers whose flow can be optimized for low temperatures and high cooling. The specific costs and also the heat losses (around 11–14%) differ little in local and district heating networks, as they are distributed to the end customer, i.e. H. It is in the " capillaries " and not on the "main arteries " of the transport routes that the major investments are necessary and the predominant network losses occur.

See also

Individual evidence

  1. ↑ KWKG 2016, §2 Definitions, No. 32
  2. ↑ Line system and house station. STEAG Fernwärme GmbH, accessed on February 25, 2018 .
  3. ↑ Feed-in sources and supply areas. Fernwärme-Verbund Saar GmbH, accessed on February 25, 2018 .
  4. ↑ Rolf Besier, Manfred Klöpsch, Alexander Wagner: Economic insulation from KMR: Is standard insulation still sufficient for plastic jacket pipes today? (No longer available online.) AGFW, November 27, 2009, archived from the original on February 26, 2018 ; accessed on February 24, 2018 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. picture 2 @1@ 2Template: Webachiv / IABot / www.agfw.de
  5. ↑ Schmitz et al .: AGFW main report 2016. AGFW, August 2017, accessed on July 22, 2018 . , P. 13