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Seawater Heat Pump

Aalborg Forsyning is establishing a seawater heat pump with a capacity of 177 MW thermal output, set to become the world's largest naturally cooled seawater heat pump. The complete system will consist of four heat pump units, each with a capacity of 44 MW thermal output. It is expected to account for nearly a third of the heating production.

Operations of the Seawater Heat Pump

The system operates by extracting heat from seawater. This is achieved by passing the seawater alongside one chamber of the heat pump, which contains a liquid coolant. This coolant has a low boiling point and evaporates when exchanging heat with water from the fjord adjacent to Norbis Park.

Following this, the vapor is compressed in a compressor, which raises its temperature. The heated vapor is then directed into the heat pump's second chamber, where it transfers its heats to the cold district heating water returning from consumers. As a result, the district heating water is heated to 90 degrees Celsius, making it ready for distribution to consumers.

Afterwards, the vapor cools down and passes through a turbine. Here, its pressure drops enough for it to condense into a cold liquid again.

The process then repeats, with both the district heating water and the coolant circulating in their separate closed loops, while the now-cooled seawater is discharged back into the fjord, completing the cycle.