District heating storage

from Wikipedia, the free encyclopedia
District heating storage for heating 1,600 residential units in London; erected around 1960.

District heating storage systems are mostly pressureless, water-filled containers that are intended to compensate for fluctuations in the heat demand of the district heating network with the same generation capacity of the district heating plants. Similarly, this type of heat storage can also be used in district cooling networks to store cold water.

Application and use

District heating storage with 100 m³ content of a biomass heating plant , around 4 MWh storage capacity per charging process in Maria Gugging

District heating networks provide customers with the necessary heat for heating purposes , hot water preparation and as process heat . The heat demand during the day (e.g. from 7 a.m. to 8 p.m.) is much higher than at night and, in particular, the peak daytime consumption between 7 a.m. and 9 a.m. is sometimes almost three times as high as the power output at night (see night reduction ). These power peaks have to be provided by heat generation systems, which requires the provision of capacities for the peak load, which are only operated for a short time - sometimes only a few minutes a day. In order to better utilize the heat generation, there is the possibility of loading heat into the storage tank at night and withdrawing it again during the day, especially at the peak of the morning.

Another application is the optimization and flexibility of the energy industry ("functional power storage") of CHP systems. When the price on the electricity exchange is low, thermal power stations shut down and heat customers are supplied from the heat storage system. The end customers get electricity from the grid. Conversely, thermal power stations can start up at high prices and feed electricity into the higher-level grid beyond the needs of local electricity customers, even if the heat demand is low, because the useful heat can be buffered in the district heating storage system. With storage on the thermal side, system operation can be made more flexible, which supports the system integration of renewable energies . The district heating storage system works in conjunction with the CHP system like an electrical energy storage system (EES): if the price is low, electrical energy is taken from the network, if the price is high, it is fed into the network.

Construction and operation of district heating storage facilities

District heating storage of the Theiss power plant with a capacity of 50,000 m³, which feeds the Krems district heating network. Storage capacity 2 GWh per charging process

District heating accumulators can basically be classified according to their construction and operation.

Classification according to construction

When classifying according to construction method, one differentiates between

  • pressureless district heating storage, i.e. operable up to a maximum of 100 ° C, and
  • Pressure accumulators that can be operated at over 100 ° C and possibly up to approx. 150 ° C.

In the case of a pressureless storage tank, the district heating storage tank itself absorbs the change in volume that occurs as a result of the heating. The water in the storage tank is not under excess pressure and can therefore only be heated up to 98 ° C. In winter, this makes reheating to the required flow temperature in the heating network necessary. An example of this type of construction is the district heating storage facility at the Theiss power plant (see photo). A pressureless accumulator can also be used as a pressure holding device; The prerequisite for this is that the water level of the storage tank is above the hydrostatic zero point of the district heating network. This means that the heat storage tank also maintains the pressure for the district heating network, as was the case with the Salzburg district heating storage tank that went into operation in 2011. If a pressureless storage tank cannot be built high enough to compensate for the hydrostatic pressure of the heating network, the return of the heating water must be let into the storage tank via a throttle when heat is withdrawn in the case of pressureless storage tanks and, on the other hand, the hot water from the top by means of a pump the pressure of the district heating network.

District heating storage in Chemnitz

This energy expenditure to increase the pressure can be dispensed with in the pressure accumulators; they also enable higher storage temperatures above the boiling point of water, which reduces the need for reheating. The change in volume due to the thermal expansion of the water is absorbed or removed by maintaining the pressure . The disadvantage of pressure accumulators is that only limited diameters are possible because otherwise the tensile forces in the accumulator wall would be too great. Therefore, larger volumes can only be represented in a modular design, which is relatively expensive (wall material) compared to large pressureless storage tanks. One example of this is the district heating storage facility in Chemnitz (see photo).

Classification according to operating mode

Buffer (heating technology) , i.e. pure use by only one consumer, a greenhouse

District heating stores can also be functionally classified according to the mode of operation and thus the number of charging cycles or the storage time constant T = energy / power. With this approach, the following types can be distinguished:

  • Minimum boiler load storage,
  • Morning peak storage,
  • Day memory,
  • Weekend storage and
  • Seasonal storage .

Cold storage

Storage tanks for cold are basically structured in a similar way to district heating storage tanks. Due to the mostly small temperature difference between the flow and return, however, these are usually particularly large in relation to their storage work.

Ice storage

(For heat storage using ice storage, see ice storage heat pump )

In the case of cold storage, there is also the special feature of the ice storage , which was previously used as ice water storage in dairies and breweries . The refrigerant (mostly ammonia in the past , now often the HFC refrigerant 134a ) is evaporated directly inside steel pipes located in a water basin. Layers of ice form on the outside. This ice stores the cold perfectly, so that sufficient cold can be provided in the event of sudden cooling water withdrawal from the water basin.

Application example : Warm milk used to be delivered to the milk collection point in the morning and / or in the evening , which had to be cooled in a short time, which periodically required high cooling energies for short periods. The ice water storage system is still ideal for this application today, as the ice required for cooling can be produced overnight or at least over a longer period and with a less powerful cooling machine than with direct cooling. For example, if 6,000 liters of milk have to be rapidly cooled from 30 ° C to 4 ° C, an ice mass of approx. 2,000 kg is required.

In newer systems, the cold from the refrigeration machine is transferred directly to a water- glycol mixture at sub-zero temperatures, which flows in plastic pipes in several rows of pipes through the cooling water basin. Ice now forms again on the coiled pipes, which can store considerably more cold than water thanks to the high melting enthalpy .

The cost savings achieved with ice storage systems are based on the fact that the compression refrigeration machine intended to cover peak loads does not run during the high tariff period and the necessary cooling is provided by the ice storage system. During the night (low tariff period) it is recharged by the refrigeration machine and new ice is provided for the day. In addition to this cost advantage through lower electricity rates, there is also a thermodynamic advantage : that is due to the lower outside temperature At night, COP of the refrigerator better, which is why the necessary for gelato lower temperature can be generated at a slightly better performance factor.

Calculation of the storage density

The storage density (kWh / m³) indicates how much energy ( kWh ) can be buffered in one cubic meter of storage. It is calculated - in the case of no phase change - by:

in which:

the temperature difference between the inflowing and outflowing medium of the storage tank in Kelvin,
the density in kg m −3 and
the isobaric heat capacity is kJ kg −1 K −1 .

In the case of a phase transition, the storage density is additionally increased. The energy stored in the phase change is calculated as follows:

in which:

the density in kg m −3
is the enthalpy of fusion kJ kg −1

Typical storage densities

  • Cold storage on the basis of one water filling: 7 kWh / m³ or 1.16 kWh / m³K per degree of temperature difference
  • Cold storage with phase conversion of water (solid-liquid): 60 to 80 kWh / m³
  • Pressureless district heating storage tank based on one water filling: 30 - 40 kWh / m³ (more in multi-zone systems)
  • District heating pressure storage: 90 kWh / m³

List of large district heating and cold storage facilities

Realized memory

Companies Location Volume in m³ Energy in MWh Type Other notes
Marstal district heating Marstal (DK) 75,000 4,350 warmth Basin heat storage for local heating network with 2,200 inhabitants, operating period since 2012
EVN AG Gedersdorf , power station Theiss / Lower Austria 50,000 2,200 warmth Height 25 m, diameter 50 m, heat supply for Krems and Gedersdorf by EVN Wärme GmbH also around 15 km to Grunddorf
Grosskraftwerk Mannheim AG (GKM) Mannheim 45,000 1,500 warmth Height 36 m, diameter 40 m, max. Water temperature 98 ° C. Supports district heating network in Mannheim, Heidelberg, Speyer. Heat flux density <12 W / m 2
Stadtwerke Potsdam HKW Potsdam South 41,224 1,200 warmth Height 48 m, diameter 45 m, commissioning January 2016; approx. 11.6 million project costs
Linz AG Linz , district heating power plant Linz-Mitte 34,500 1,350 warmth Height 65 m, diameter 27 m; Storage temperature between 55 and a maximum of 97 ° C
N-ERGIE AG Nuremberg , Sandreuth cogeneration plant 33,000 1,500 warmth Height 70 m, diameter 26 m; Pressureless two-zone storage tank with temperatures up to 113 ° C, investment volume 12 M €, commissioning Jan 2015
Dong Energy Denmark, Studstrup power plant 30,000 1,200 ∗ warmth
Stadtwerke Flensburg Flensburg 29,300 1,100 warmth Commissioning in January 2013 with a 30 MW electric boiler
Salzburg AG Salzburg 29,000 1,100 warmth Height 44 meters, diameter 29 m, put into operation in December 2011
Fernwärme Verbund Saar GmbH Dillingen / Saar , ZKS site 22,800 912 ∗ warmth Height 60 m, diameter 22 m, photo
Timelkam power station Timelkam , Austria 20,000 800 ∗ warmth Max. Water temperature 98 ° C, commissioning end of 2009
E.ON Thüringer Energie AG Jena 13,000 520 ∗ warmth Height 43 meters, diameter 21 meters; Construction period 2010–2011.
Hrvatska Elektroprivreda Osijek, Croatia 11,400 warmth Height 50 meters, diameter 17.8 meters, operating pressure 16 bar.
Wien Energie Vienna 11,000 850 warmth Two tanks, each: height 45 meters, diameter 14 meters; Pressure accumulator 6 bar (head pressure); Commissioning at the end of 2013
Engie Kraftwerk Zolling GmbH & Co. KGaA Zolling 10,000 400 warmth Height 23 m, diameter 24 m, pressureless storage tank with a maximum water temperature of 95 ° C, in operation since 1988
District heating plant Neukölln AG Berlin , Weigandufer heating plant 10,000 300 warmth Height 22 meters, diameter 26 meters; converted heating oil tank, 2.8 M €, commissioning March 2015, 4 * 2.5 MW electric heater
Stadtwerke Augsburg Energie GmbH Augsburg , Augsburg Ost thermal power station 8,000 320 ∗ warmth
Stadtwerke Chemnitz Chemnitz , Georgstrasse 8,000 warmth 36 pressure accumulators ( 50 ° 50 ′ 32.49 ″  N , 12 ° 55 ′ 14.44 ″  O )
Stadtwerke Münster Muenster 8,000 warmth Four storage facilities á 2000 m³, to the combined cycle power plant Münster Hafen ; installed in the old coal bunker at the port
Offenbach energy supply Offenbach , Goethering 8,000 250 warmth Investment of 2.36 M € for storage and control systems
EVH GmbH Halle (Saale) , HKW Dieselstrasse 6,800 280 warmth Height 22 m, diameter 22 m; Commissioning in 2006
Østkraft Rønne 6,700 268 ∗ warmth Wood as an energy source: Table 19 with a description of the system
Boehringer Ingelheim Biberach 6,500 45 ∗ cold Height 27 m
Stadtwerke Munich Munich 5,700 330 warmth Operating period since 2007
Vestkraft amba Måbjerg near Holstebro 5,000 200 ∗ warmth Wood as an energy carrier: Figure 25, process flow diagram of the plant
Assens Fjernvarme Assens 5,000 200 ∗ warmth Two storage tanks of 2,500 m³ each; Reconstruction of old oil tanks
E.ON Hanse Wärme GmbH Hamburg 4,150 240 warmth "Hamburg II", operating period since 2010
Elektrizitätswerk Wels AG catfish 4,000 160 ∗ warmth
Stadtwerke Chemnitz Chemnitz , Georgstrasse 3,500 32 cold Height 19 m, diameter 17 m; Short-term large cold storage
Stadtwerke Leipzig Leipzig, Arno-Nitzsch-Strasse 3,000 225 warmth 9 storage tanks each 29 m high, 4 m diameter, pressure storage tank; 3.5 million euros.
Großkrotzenburg municipal works Großkrotzenburg 2,800 100 warmth Height 25 m, diameter 12 m, flat bottom tank, Hedbäck system (floating nozzle), can be used to maintain pressure.
Pimlico District Heating Undertaking London 2,500 100 ∗ warmth Height 41 meters, commissioned in 1950, originally powered by Battersea Power Station
District heating Ulm GmbH Ulm , MHKW Danube Valley 2,500 140 warmth Height 29 meters, diameter 11.5 meters; Operating pressure 5.7 bar; Commissioning in 2014, project costs approx. 2.8 million euros
Solar complex Emmingen-Liptingen , Emmingen bioenergy village 1,000 46 warmth Height 6.4 m, diameter 16 m; Temperature range 55 ° C to 95 ° C; 1000 W maximum power; above-ground tank storage
Stadtwerke Rosenheim Rosenheim , Färberstrasse 500 20th warmth Height 20 meters, diameter 4 meters, 2 pieces, photo
Bioenergy Steyr Behamberg, Ramingdorf 5 250 17.5 ∗ warmth Height 20 meters, diameter 4.2 meters, operating pressure 16 bar, storage temperature 160 ° C; Commissioning October 2012
Stadtwerke Zehdenick Zehdenick , Friedhofstrasse 150 10.5 ∗ warmth 3 storage tanks each 11 meters high, 2.5 meters in diameter, operating pressure 16 bar, storage tank temperature 85 ° C; Commissioning January 2004
medl GmbH Mülheim an der Ruhr, Duisburger Strasse 50 900 57.6 warmth 4 tanks of 225,000 l each, 2 tanks IB 1998, expansion by two tanks in 2015

Operation with water, 115/60 ° C, 8 bar

∗Calculated with the information on the volume and the values ​​of the typical storage densities .

Storage in planning and construction

Shell construction of the Kiel district heating storage facility, June 2016
Companies Location Volume in m³ Energy in MWh Type Other notes
Vattenfall Europe Wärme AG Berlin , Reuter West thermal power station 60,000 2,500 warmth Diameter 44 m, height 45 m; Investment volume approx. 20 M €, commissioning planned for 2016
Stadtwerke Kiel Kiel 42,000 warmth Height 60 m, commissioning planned for the end of 2016
Stadtwerke Düsseldorf Düsseldorf , on the Lausward 35,000 1,480 warmth Height 57 m, diameter 30 m; Commissioning planned for the end of 2016
Agro Energie Schwyz AG Ibach, near Schwyz 28,000 1,300 warmth Height 50 m, diameter 30 m, pressureless, flow 95 ° C, return 50 ° C, commissioning 2020
Stadtwerke Neubrandenburg Neubrandenburg 23,000 700 warmth Height 36 m, diameter 30 m, commissioning 2020
Vattenfall Hamburg , Tiefstack thermal power station 20,000 900 warmth planned commissioning 2014
Stadtwerke Heidelberg Heidelberg 20,000 warmth Height 55 m, gross volume 20,000, net 12,800, two-zone up to 115 ° C, until the end of 2019

See also

Web links

  • Feasibility study (PDF; 16.3 MB) to strengthen the combined heat and power generation through the use of cold storage in large supply systems, Chemnitz
  • Saisonalspeicher.de The knowledge portal for seasonal heat storage

Individual evidence

  1. ↑ Video: Short film describing the construction and use of the district heating storage facility in a London housing estate on YouTube , from August 29, 2010.
  2. ↑ FfE: Functional Electricity Storage: Derivation and Definition .
  3. ↑ a b Environmental Declaration of Theiss Power Plant 2012 as of November 2012.
  4. ↑ a b c d e Andreas Oberhammer: District heating storage . ( Memento of the original from December 28, 2013 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. District heating days 2012 (PDF file). @1@ 2Template: Webachiv / IABot / www.gaswaerme.at
  5. ↑ a b c d Ernst-Rudolf Schramek: Pocket book for heating + air conditioning. 07/08. As of September 11, 2010 ( limited preview in Google Book Search)
  6. ↑ Eisspeicher Photos ( Memento of the original from October 25, 2009 in the Internet Archive ) 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. tu-dresden.de, as of September 11, 2010. @1@ 2Template: Webachiv / IABot / tu-dresden.de
  7. ↑ PlanEnergi: Summary technical description of the SUNSTORE 4 plant in Marstal. (PDF) (No longer available online.) December 12, 2013, archived from the original on January 3, 2016 ; accessed on January 3, 2016 . 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. @1@ 2Template: Webachiv / IABot / www.solarmarstal.dk
  8. ↑ Marstal | Saisonalspeicher.de. In: www.saisonalspeicher.de. Retrieved June 10, 2016 .
  9. ↑ MVV Energie: New district heating storage is integrated into the network. Press release. June 13, 2013, accessed June 17, 2016 .
  10. ↑ Grosskraftwerk Mannheim AG: With insulation towards the energy transition
  11. ^ Märkische Allgemeine Zeitung: Gigantic heat storage for Potsdam. January 14, 2016, accessed January 15, 2016 .
  12. ^ Linz AG: District heating power station Linz-Mitte. Retrieved January 15, 2016 .
  13. ↑ N-ERGIE: N-ERGIE heat storage: commissioning successful. Press release. January 9, 2015, accessed June 17, 2016 .
  14. ↑ N-ERGIE: Landmark of the energy transition - N-ERGIE's heat storage system. (PDF) June 2015, accessed June 17, 2016 .
  15. ↑ DONG Energy A / S (ed.): The Studstrupværket . CHP plans. S. 6 (English, online [accessed on September 13, 2013] brochure).
  16. ^ Stadtwerke Flensburg: Combined heat and power - Environmentally friendly generation. Retrieved June 17, 2016 .
  17. ^ "ZEK" trade journal, December 2011 edition
  18. ↑ Lebens.linien, news for customers of Salzburg AG. November 2011, accessed on June 13, 2016 (No. 50).
  19. ↑ Picture of the Dillinger Hafen and in the middle the district heating storage on the hut area behind , as of 2017-06-16.
  20. ↑ Description of the project on page 11 ( Memento of the original from February 18, 2014 in the Internet Archive ) 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. (PDF) As of October 20, 2010. @1@ 2Template: Webachiv / IABot / www.energieag.at
  21. ↑ a b c Heat storage - Bilfinger Bohr- und Rohrtechnik GmbH. In: www.bur.bilfinger.com. Retrieved June 15, 2016 .
  22. ↑ The world's first high-pressure heat accumulator. (No longer available online.) Vienna City Administration (energy planning), 2014, archived from the original on June 17, 2016 ; Retrieved June 17, 2016 . 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. @1@ 2Template: Webachiv / IABot / www.wien.gv.at
  23. ↑ Verbal inquiry with the operator.
  24. ↑ Investment in the heating transition: thermal storage and immersion heaters are the trend
  25. ↑ FHW Neukölln AG puts heat storage and power-to-heat system into operation , press release from March 5, 2015
  26. ↑ Manufacturer information from Kraftanlagen München ( Memento of October 21, 2004 in the Internet Archive ) as of December 31, 2008.
  27. ↑ CCGT system and district heating storage ( Memento of the original from August 16, 2014 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. on the website of Stadtwerke Münster @1@ 2Template: Webachiv / IABot / www.stadtwerke-muenster.de
  28. ↑ https://www.evo-ag.de/technik-und-umwelt/heizkraftwerk/
  29. ↑ Stadtwerke Offenbach: Annual Report 2013 , Group fixed assets as of 2013-12-31, acquisition and production costs, p. 26
  30. ↑ Press release from September 25, 2012
  31. ↑ a b c Scheme of the Måbjerg district heating system (PDF file; 180 kB) Status: December 31, 2008.
  32. ↑ R&D for large cold storage meets with a positive response . As of May 21, 2009.
  33. ↑ Responsible Care® report 2009: New refrigeration supply in Biberach ( Memento from February 5, 2007 in the Internet Archive ) (PDF file) page 21, as of May 21, 2009.
  34. ↑ Munich | Saisonalspeicher.de. In: www.saisonalspeicher.de. Retrieved June 10, 2016 .
  35. ↑ Photo of the district heating storage system as of July 25, 2010.
  36. ↑ Hamburg II | Saisonalspeicher.de. In: www.saisonalspeicher.de. Retrieved June 10, 2016 .
  37. ↑ District cooling. Retrieved May 11, 2017 .
  38. ↑ Description of the Chemnitz cold storage project as of December 31, 2008.
  39. ↑ Chemnitz large cold storage facility  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. (PDF file), as of September 12, 2010.@1@ 2Template: Dead Link / www.swc.de  
  40. ↑ Storage for the Leipzig district heating network
  41. ↑ Kai Imolauer: bulk buffer to secure the district heating network Grosskrotzenburg, Kursbuch public utilities, December 2013
  42. ↑ Archived copy ( Memento of the original dated June 11, 2015 in the Internet Archive ) 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. @1@ 2Template: Webachiv / IABot / www.cwh.org.uk
  43. ↑ Experience report on the FUG heat storage system ( Memento of the original from January 14, 2016 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. 5th April 2014 @1@ 2Template: Webachiv / IABot / www.ulm.de
  44. ↑ http://www.solarcomplex.de/energieanlagen/bioenergiedoerfer/emmingen.html
  45. ↑ Emmingen thermal storage facility. Retrieved May 12, 2017 .
  46. ↑ Power Bladl customer magazine of Stadtwerke Rosenheim (PDF file; 437 kB), title page and page 6, as of May 31, 2009.
  47. ^ Andreas Oberhammer: Biomass district heating for Steyr. ( Memento of the original from September 28, 2013 in the Internet Archive ) 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. District heating days 2013, (PDF file; 18.2 MB) @1@ 2Template: Webachiv / IABot / www.gaswaerme.at
  48. ↑ [1]
  49. ↑ Heat storage at the Reuter West location ( memento of the original from January 3, 2016 in the Internet Archive ) 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. , Leaflet March 2013 @1@ 2Template: Webachiv / IABot / www.berlin-klimaschutz.de
  50. ↑ Stadtwerke Kiel: 24 concrete mixers in use: Stadtwerke pour base plate for new heat storage. Press release. August 21, 2015, accessed June 17, 2016 .
  51. ↑ Stadtwerke Düsseldorf: A district heating storage system should make the new natural gas power plant on Lausward even more climate-friendly and flexible. Press release. April 8, 2015, accessed June 17, 2016 .
  52. ↑ Agro Energie Schwyz AG: Flyer heat storage, Agro Energie Schwyz AG. In: https://agroenergie-schwyz.ch/ . Agro Energie Schwyz AG, February 18, 2018, accessed on June 5, 2020 .
  53. ^ Stadtwerke Neubrandenburg build heat storage. Retrieved January 18, 2020 .
  54. ^ Vattenfall: First groundbreaking for heat storage by Mayor Scholz. Press release. August 8, 2013, accessed June 17, 2016 .