An economic comparison between two district cooling systems in Halmstad
Independent thesis Advanced level (degree of Master (One Year)), 40 credits / 60 HE creditsStudent thesis
The supply of cooling has increased significantly in recent years, the trend shows that the increase will continue one reason is that the standard of living has increased, but EU has also set a requirement that energy consumption must be better at the same time. With “better” means more efficient and environmentally friendly. District cooling today uses either chillers or naturally available cold sources such as deep sea water, lake water or cold air. Cold air is, of course, only available when the seasons permit it and the cold air is not available when comfort cooling is needed for e.g. offices. The only alternative for areas that do not have a cold water source nearby is to use chillers. The most common chillers today are compressor chillers and absorption chillers.
The most interesting chiller for the energy and environmental company HEM in Halmstad, is the absorption chiller which is driven by heat. HEM has, during the summer, surplus heat produced in Kristinehed plant which they want to use, they also have an increased inventory of waste during the summer which they get from the municipality of Halland. This heat is, of course, qualified to be used in the making of cold. Absorption chillers is today, however, not as common as compressor chillers which are capable of dealing with most cooling capacities, from small to large, and simultaneously works more or less flawlessly. Most of today’s absorption chillers are of a few hundred kW and upwards while there are no absorption chillers for the smaller effects, they are also very expensive and can have problems with crystallization of the absorbent if the operation is handled incorrectly.
But it’s also expensive when it comes to piping of district cooling networks depending on where the pipes are desired, for example if it is the middle of town or over a grass field. A fictional project of the area Sannarp is used for a case study in this thesis where one investment alternative was to extend the existing district cooling pipes and another alternative was to invest in absorption chillers to meet the company's cooling demand. The results were obviously much affected by the area's layout and the distance to the first company starting from the existing pipe. The company's cooling demand also affected the results and the first alternatives investment cost could only be competitive with alternative 2 because the distance was just of the right length. If the distance to the company had been shorter, then the cooling demand for the same company has had to be less.
The conclusion of the project was still in the end that and expansion of the current district cooling network to the company was the most feasible and economically advantageous.
Place, publisher, year, edition, pages
2014. , 40 p.
economic comparison between two district cooling systems in Halmstad absorption chiller district heated cooling
ekonomisk jämförelse mellan två fjärrkyle system i halmstad fjärrvärme driven kyla absorptionskyla
IdentifiersURN: urn:nbn:se:hh:diva-25752OAI: oai:DiVA.org:hh-25752DiVA: diva2:726861
Subject / course
Gong, Mei, Universitetslektor Energiteknik
Hylander, Jonny, Professor i energiteknik