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In-situ research of a district heating system to assess its capability to operate at reduced flow temperatures

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  • Sekret, Robert
  • Kotowicz, Janusz

Abstract

This paper presents the process of developing an innovative method and its experimental verification, as well as a calculation algorithm for determining the reduced nominal supply and return temperatures of a district heating system. The aim of creating this new methodology is to enhance the energy efficiency of district heating systems. This was achieved by using the heat flow surplus of the district heating system and the reduction in heat demand of buildings resulting from their thermal modernisation. The 10-year research project studied a district heating system with a thermal power of 327 MW. The paper also describes how to apply the new operating temperatures to the district heating system. The system successfully reduced the supply temperature from 150 °C to 118 °C and the return temperature from 80 °C to 60 °C. This reduction in temperature allowed for an improvement of 19.18 % in the heat transfer and delivery efficiency of the district heating system, without exceeding the nominal heat transfer fluid flow in the district heating network. This increase in energy efficiency was achieved without any significant investment costs, with CO2 emissions reduced by 5.230 kg per GJ transported by the district heating system. The research also found that reducing operating temperatures resulted in up to 88 % fewer faults and failures, thereby increasing the availability and lifespan of the entire system.

Suggested Citation

  • Sekret, Robert & Kotowicz, Janusz, 2025. "In-situ research of a district heating system to assess its capability to operate at reduced flow temperatures," Energy, Elsevier, vol. 337(C).
    • Handle: RePEc:eee:energy:v:337:y:2025:i:c:s0360544225042732
    DOI: 10.1016/j.energy.2025.138631
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    References listed on IDEAS

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