Process engineering components for district heating networks

    • National and international standards

      Plate heat exchangers for district heating networks

District heating (term)

District heating is a surplus of heat generated in various different industries, e.g. in power generation via cogeneration in combined heat and power plants or in steel production or processing, that is subsequently used in building services to supply heating and hot water. However, a variety of suppliers could be considered a „source“ of waste heat, such as geothermal power plants, seasonal large-scale heat storage, and the like.

Examples of suppliers of district heating networks:

  • Combined heat and power (CHP) plants
  • Biomass power plants
  • Geothermal power plants
  • Solar thermal power plants
  • Large-scale seasonal thermal energy storage (STES) (Wind/solar power)
  • Industrial enterprises (steel production and processing,…)

Due to the energy losses occurring when transporting heat via an isolated pipeline system with hot water, the efficiency of the respective district heating network decreases the bigger the radius of residing recipients. For this reason, the consumers of a district heating network are usually located within a radius of less than 20 kilometers from the supplier.

Significance for the carbon footprint

Currently, roughly 84% of the entire thermal energy in district heating networks is obtained through cogeneration. The principle of the twofold use of fuel — for power generation and waste heat in the district heating network — is proving to be extremely efficient.

Nonetheless, the combustion of pellets or other fossil fuels produces considerable CO2 emissions, so that a conversion from district heating networks based primarily on cogeneration to new, innovative networks with solar thermal systems, large-scale STES, as well as geothermal energy and waste heat from various industries is appreciated.

District heating (principle)

District heating is mostly produced in CHP plants. The heat transfer medium in the district heating network is usually water heated by means of a condenser (superheated steam from power plant), which is then transported to the consumer via an insulated pipeline system and a district heating transfer unit. There it provides thermal energy for heating purposes as well as service water for private, public or commercial households and proceeds to flow back to the supplier (e.g. CHP plant).

Plate heat exchangers from XELSION heat transfer solutions

Within the framework of various cooperations and the use of synergies in our ZILONIS corporate group, we have specialized in the technical design, construction, manufacture and supply of plate heat exchangers, also for district heating networks. Thus, our customers benefit from an efficient interaction of high-quality components in a finished product manufactured according to national and international standards.

With XELSION heat transfer solutions, you have a reliable partner that offers custom solutions. Depending on your requirements, you can choose from a variety of models with specific connector types, a number of heating circuits based on your needs, and the right choice for domestic water heating.

Our focus:

  • Reliable provision of ready-to-use hot water in the consumer circuit.
  • Precise measurements of the amount of heat in the consumed hot water.
  • Accurate control of the differential pressure on the primary side.
  • Limitation of the flow rate of the district heating water based on agreed upon contractual performance.
  • Hydraulic separation of the domestic system from the district heating network in the heat exchanger.
  • Limitation of the secondary return temperature by means of a temperature sensor placed in the consumer circuit.
  • Reduction of the flow temperature in hot water networks with the aid of a safety temperature controller.

Product range for district heating networks:

  • Sealed plate heat exchangers
  • Brazed plate heat exchangers
  • Complete district heating transfer stations

Single-family homes
5 to 50kW

Apartment buildings
70 to 150kW

Offices/Shops
70 to 150 kW

Administration/industry
100 to 5,000kW

Agriculture
100 to 5,000kW

Hospitals
1,000 to 20,000kW

Performance

The dimensions of your district heating transfer unit majorly depend on how high the heat demand of the premises to be supplied is. Additionally, the temperature and pressure of the primary energy supply affect whether your transfer unit is operated directly or indirectly.

We speak of an indirect district heating transfer station when the heating water of the domestic system is decoupled from the local heating network by a heat exchanger. In contrast, when the heating water from the local heating network flows through the domestic system, we speak of a direct transfer station.

The design of your consumer-driven district heating transfer unit primarily depends on the heat demand for the service water to be used and only secondarily on the primary demand for heating. This is due to the fact that the temperature of the hot water system must be kept at at least 60° Celsius to prevent contamination of the water by, for instance, legionella.

  • Sealed Plate Heat Exchangers

    Our XP series includes a broad spectrum of sealed plate heat exchangers for various different application possibilities in almost every branch.

    We always find the best solution for your individual requirements through flexible construction and a wide range of plate and connection sizes.

    • done_all High energy efficiency

    • done_all Low operating costs

    • done_all Flexible construction

    • done_all Diverse application possibilities

    • done_all Low maintenance

    • done_all Individual connection widths from NPS 25 to NPS 650

    • done_all Wide range of materials (e.g. 1.4031, 1.4404, titan, 254 SMO, alloy C-276)

    • done_all Wide range of sealing materials (e.g.. nitrile, EPDM, viton, mixed sealing)

  • Brazed Plate Heat Exchangers

    The brazed plate heat exchangers in our XPB series consist of a package of embossed stainless steel plates which are soldered together in a special procedure. Depending on the specific requirements, we utilize different materials such as copper, nickel or stainless steel. Thanks to the specifically embossed plates that generate a highly turbulent flow, a brazed plate heat exchanger is able to realize even the smallest differences in temperature, and that with next to no maintenance. Moreover, these devices are perfectly suitable for high pressures (up to 50 bars) and temperatures (up to 200°C) due to their compact and brazed design.

    • done_all Extremely compact design

    • done_all Withstands high pressures (up to 50 bars)

    • done_all High energy efficiency

    • done_all Low operating costs

    • done_all Low maintenance

    • done_all Diverse application possibilities

    • done_all Wide range of materials (copper, nickel, stainless steel)

    • done_all Individual connection widths (from 1/4" to NPS 150)

Your request

Thank you for your interest in heat exchangers for district heating networks from XELSION heat transfer solutions. We would be pleased to inform and advise you in advance about the most suitable application for you. Please do not hesitate to contact us.

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