Delft University of Technology Partners with Danfoss for Sustainable Heating System

Introduction

Delft University of Technology (TU Delft) aims to achieve a carbon neutral, circular and climate adaptive campus by 2030. A key initiative is the university's geothermal project, designed to provide sustainable heating to the campus and approximately 6,000 households in Delft. This project is linked to scientific research on geothermal energy use in urban environments. TU Delft partnered with Danfoss to upgrade the campus' infrastructure for this transition by installing new, efficient heat substations.

[Image: Aerial view of TU Delft campus buildings, one prominently featuring the 'TU Delft' logo, with a Danfoss logo visible in the corner.]

Challenge: Transition to Geothermal Energy

TU Delft currently uses a combined heat and power plant (CHP) to heat approximately 430,000 m² of buildings, with temperatures ranging from 80 to 130°C. Many buildings are designed for a 90/70°C supply/return temperature. To optimally utilize geothermal energy, this range needs to be lowered to 78/53°C.

To achieve this, TU Delft decided to replace existing tube heat exchangers with more efficient plate exchangers in new heat substations. These facilitate a smaller temperature difference and lower the required supply temperature from the distribution network. The university selected Danfoss for the design and delivery of these substations.

[Image: Panoramic view of the TU Delft campus, showing multiple buildings and green spaces.]

[Image: Close-up view of industrial heating equipment, showing pipes, valves, and gauges within a substation.]

[Image: Another close-up view of industrial heating equipment, showing a complex network of pipes and valves in a plant room.]

Solution: Customised Substations

TU Delft has installed 48 Danfoss substations with capacities from 100kW to 2.5 MW. Additionally, four extra substations were installed to replace indoor gas boilers in buildings connecting to the new heat network and geothermal source.

The Danfoss district heating specialists designed and built these substations, adapting a standard solution to meet TU Delft's specific requirements:

• Heat exchangers must guarantee optimal output at both 100°C and 80°C supply temperatures to accommodate the shift to geothermal energy.
• The station design needed flexibility for the wide range of campus buildings.
• Station frames (skids) were designed to be modular for transport through elevators and narrow passages.
• Substations required delivery within a short timeframe.

Installers used 3D scans to ensure substation design compatibility. Danfoss produced the stations and components in-house, adhering to the European Pressure Directive PED 97/23/EC. The AFQM 2 pressure-compensated control valve was a key factor in TU Delft's selection, ensuring precise power regulation and system protection against pressure spikes, fluctuations, cavitation, and noise.

[Image: Interior view of a substation room showing a network of insulated pipes, valves, and control panels. A yellow temperature gauge with markings from 0 to 120°C is visible.]

[Image: Another view of industrial heating equipment within a substation, featuring various pipes, valves, and a blue component.]

[Image: Close-up of a Danfoss branded component within a substation, showing electrical connections and a logo.]

Results: On the Way to Carbon Neutral

The geothermal source is expected to save 85% of TU Delft's annual gas consumption, equating to almost 4 million m³ of gas per year, a significant step towards a CO₂-neutral campus. The combination of the AFQM 2 valve, Danfoss heat plate exchangers, and building automation ensures optimal heat transfer without energy waste.

"Danfoss' prefabricated heat substations gave us a high-quality standardized solution, while still allowing us to customize specific aspects of the installation. Their professional implementation ensured that we could complete the installation process within the specified timeframe."

— Lennart Burg, Senior Project Manager, TU Delft/ Campus Real Estate & Facility Management

[Image: Interior view of a substation room with extensive pipework, insulation, and valves, similar to other substation images.]

Further Information

Further information is available on Danfoss' website: danfoss.com