En systemlösning för en framtida fjärrvärmeutbyggnad i Täby : ur Fortum Värmes perspektiv

Sammanfattning: At the moment in central Täby there are small district heating network operated by Fortum Heat. The distribution network has an annual heat demand of about 70 GWh, which is supported by the network's two plants, Galten and Farmen. Täby as a region is rapidly growing and there are grand plans to develop the area. Estimated market potential for a future district heating expansion in Täby is very high and as early as in 2007 Täby decided to invest in a large-scale expansion. In autumn 2009 Täby did a procurement process, known as the ‘Täby initiative’, to find a partner that could implement those expansion plans. To secure a cheap basic production the partner also need to build a power plant at Hagby recycling center. Despite high interest during initial state of the process, only one procurement offer were received and Täby suspended the contract in March the following year. In autumn 2010 Täby started a new procurement process to once again try to find an appropriate partner for this task. To investigate Fortum’s opportunities in such a partnership the company conducted during spring 2011 a detailed feasibility study where this master thesis is included as a part of the result. The sole purpose of this study is to develop a system solution for the future development of district heating in Täby, as seen from Fortum's perspective. The results of this thesis show that parts of the existing network needs to be sized up in order to not be a limitation in the network when it is fully constructed. To minimize production costs while facilitating a gradual expansion of the network, it is recommended to construct a smaller intermediate load facility locally in Täby. The load facility should be based on wood powder and have a production capacity of 20 MW. Based on the development, it is most favorable if the load facility was placed between the existing Täby-network and Arninge. To ensure high reliability of heat supply the pump station alone should be able to supply the entire Täby area. The pump station should preferably be symmetrical, and placed prior to the first customer in Enhagen. The pipeline between the Northwest network and Täby should be of size DN500. To ensure that the local load facility will be capable of supplying the central network during the expansion stage, the pipeline between the existing network and the load facility needs to be of size DN300.