| Summary: | This degree project investigates the technical and economic possibility of a heat recovery system on Hovdestalund crematorium. The crematorium will have a solution that allows the facility to become both a producer and consumer to the district heating network. This work became relevant because the Swedish church is going to expand Hovdestalund with additional ovens and therefore energy efficiency is in their sight. With the help of Mälarenergi, a business model to be connected to the district heating network is created for Hovdestalund. The project will go through how to handle the flue gases, either by connecting the crematorium to the district heating network, or to cool down the gases with a cooling tower. When using the flue gases for district heating, two cases of different heat recovery potential are investigated. The first case is taken from an already made investigation by Kadesjös on Hovdestalund where they assume a potential of 400kWh/cremation. The second case is taken from literature study where the potential is 242,5kWh/cremation. A technical solution that can separate when heat is supplied to the network versus withdrawn is chosen to help with billing and general surveillance across the system. Connecting Hovdestalund to the network will not affect Mälarenergi’s operation negatively, the temperature can reach around 95 degrees Celsius and thus considered as high-grade heat. Having a lower temperature supplied to the network at a higher amount could lead to some problems in lowering the networks overall temperature. Using a cooling tower would not be as optimal as it would only cool down the flue gases, there would be no self-consumption nor heat sold to the network. Most of the investment cost will come from laying down a new pipeline for the district heating. The pipeline will have a length of roughly 140m which results in a cost of ~1MSEK. Along with the district heating unit, the total investment cost becomes 1 138 000 SEK. To investigate the economic possibility, the net present value is used. The systems profit comes from selling excess heat or the value of self-consuming heat rather than buying it from Mälarenergi. Between the two recovery potential cases, bought heat, self-consumed heat, and heat demand will be the same as the only difference will be the amount of sold heat. These will be the same because during operation time of the ovens, the recovered heat will cover the hourly demand entirely. In case 1, the amount of sold heat will result in ~90tSEK annually which will lead to a payback time of 6-7 years. Case 2 will sell heat for ~45tSEK annually, this will lead to a payback time of 8-9 years. Compared to Kadesjös result which received a final cost of 10MSEK after 20 years, this report shows a final cost of 7,4MSEK and 6,49MSEK based on recovery potential.
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