Implemented in Avedøre Landsby, Denmark, the project involves a new hybrid district heating system for a village district with 300 consumers. Key components include a temperature-flexible district heating interface unit, a Flex-Temperature District Heating grid, and a Flex-Energy Central with a cascade-coupled heat-pump system, a boiler modified for green fuels, and a PV array.
Advantages of low-temperature district heating (LTDH) and ultra-low-temperature district heating (u-LTDH) systems are highlighted, emphasizing lower heat losses, increased integration of renewable energy sources, and the use of plastic distribution pipes. However, challenges include retrofitting existing housing designed for higher temperatures.
The article introduces the Flex-Booster Heat Interface Unit (HIU), a cost-efficient solution for u-LTDH systems. It provides temperature flexibility, ensuring economic operation of the district heating grid and offering advantages such as increased COP (Coefficient of Performance) and reduced pipe dimensions. The Flex-Booster’s modular configurations accommodate various consumer needs, enabling flexibility for different-sized consumers and large-scale users.
The system’s testing and configurations demonstrate its viability, showcasing the ability to supply both space heating and domestic hot water (DHW) efficiently. The Flex-Booster’s performance, especially its COP and ability to sub-cool the return temperature, contributes to reduced energy consumption and optimal grid design.
The article concludes that the new concepts, including the Flex-Booster HIU and associated heat pumps, provide temperature flexibility in u-LTDH grids, eliminate the need for extensive system modifications in end-user installations, and offer improved performance with reduced costs. The system addresses diverse market needs, including natural gas conversions, district heating districts, and individual houses as co-producers. The approach represents a significant step towards achieving a sustainable and CO2-neutral energy system in Denmark.
Reto M. Hummelshøj, Denmark
This text has been shortened by the HPC team
