4DH partner DESMI has supplied energy efficient, in-line, vertical NSL centrifugal pumps for one of the world’s largest solar heating plants: The Dronninglund Solar Thermal (District Heating) Plant in the northern part of Denmark.

This particular solar district heating plant has a water thermal storage reservoir of 60,000 m³. 2,982 solar panels with a total surface area of 37,275 m2, which is equal to more than 5 football pitches.
DESMI pumps are used for circulation applications in primary as well as secondary areas, and shunt pumps are also supplied.

Typically, these types of pumps have energy efficiency levels well above 80%. With proper use and maintenance, it is not unusual that these pumps can perform over the entire lifespan of such a solar plant (25 years) and this obviously contributes to the sound economy of the project.

For low-temperature district heating applications DESMI has developed the so-called “Spacer Design”, which results in very easy maintenance since the design allows the motor to stay onto the pump during service - and the pump can remain installed in the pipework, while it is being serviced. This design can be supplied for both vertical and horizontal, in-line as well as end-suction executions, flow capacities up to 5,400 m³/h and with pressure ratings up to PN25.