SUSTAINABLE E NERGY PRODUCTION
District cooling for Aalborg University Hospital Client Aalborg Forsyning Photo Aalborg Portland
A cooling resource that is d rawn up from the depths of a lake When the new Aalborg University Hospital is completed, it will be cooled with water from the chalk lake at Aalborg Portland. This is a solution that results in massive savings economically and in the carbon balance.
The cement manufacturer Aalborg Portland uses massive quantities of chalk in its production process. Many excavations have over time formed a chalk lake at the company's facilities, and this will now provide district cooling for the new Aalborg University Hospital. The water near the bottom of the more than 30 metre deep lake has a temperature ranging between 4 and 14 degrees throughout the year. This is a resource that in the future will provide electricity savings of approximately 80 % compared with an ordinary cooling system. The 170,000 m² hospital at Gistrup will make use of the cooling for patient rooms, personnel and clinical facilities and medical equipment. Moreover, a total of 500 to 700 tonnes of carbon dioxide will be saved per year by using a climate-friendly solution.
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How cold water travels MOE is the consultant to the client Aalborg Supply for the lake water heat exchanger building and the cooling distribution centre, each of which plays an important role in the comprehensive system. The cold water from the bottom of the lake is pumped up into the lake water heat exchanger building first. The heat exchanger uses the cold from the lake to cool the water in the piping that runs to and from the cooling distribution centre at the hospital. The systems are thus separate, and the water in the piping contains corrosion protection and is softened, so that the pipes do not corrode or become blocked by lime deposits etc.
The water is transported approximately 3.5 km to the hospital's 800 m² cooling distribution centre. The water is delivered at a temperature of 12 degrees, and is returned in the direction of the lake water heat exchanger station at a temperature of 18 degrees. The cycle is completed when the heat is diverted by the heat exchanger into the surface water of the chalk lake. The plant is expected to become operational in mid-2021.
