Examensarbeten för masterexamen // Master Theses
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Browsar Examensarbeten för masterexamen // Master Theses efter Program "Innovative and sustainable chemical engineering (MPISC), MSc"
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- PostAnalysis of a Recirculating Aquaculture System - n analysis at Lantfisk(2018) Andersson, Amanda; Gerdtsson, Måns; Chalmers tekniska högskola / Institutionen för arkitektur och samhällsbyggnadsteknik; Chalmers University of Technology / Department of Architecture and Civil Engineering
- PostDetecting State of Charge in PCMs - Experimental investigation of changes in chemical and physical properties during phase transitions(2016) Paberit, Robert; Öjerborn, Johan; Chalmers tekniska högskola / Institutionen för bygg- och miljöteknik; Chalmers University of Technology / Department of Civil and Environmental EngineeringThe energy use in the residential sector has steadily increased during the last decades as a consequence of an increased demand for heating and cooling in buildings. One of the main problems when it comes to indoor climate control is that the energy is not used efficiently. For instance, energy is used to heat the building during cold nights and additional energy is used to cool the building during hot days. Ideally the excess energy generated during the day could be stored and then released into the building during the night, thus reducing the energy use and energy losses. This effect could be realized utilizing the potential of phase change materials (PCMs). A PCM is a material that is able to store and release large amounts of energy with respect to its volume through solid-liquid phase transitions. By introducing PCMs in building envelopes it is possible to reduce the energy demands for indoor climate control in the building up to 25 %. To facilitate implementation of PCM solutions in buildings it is important to be able to visualize that the material is active. This can be done by measuring the proportions of the material that is either in liquid or solid state, also called the state of charge (SOC) at any given time. The main purpose of this master’s thesis is to investigate non-destructive and quantitative methods to measure the SOC in order to support implementation of technical PCM solutions in the future. It is also important that the methods can be commercially suitable when it comes to economic, environmental and technical aspects. This has been done utilizing the fact that the physical, chemical and thermal properties of a material changes during phase transitions and could possibly be correlated to the SOC. Based on the results presented in this study, changes of certain properties correlate better to the SOC than others depending on the investigated PCM type (polymers, sugar alcohols and salt hydrates). The change in light transmittance as a PCM undergoes phase transition has seen to correlate well to the SOC for all of the investigated PCM types, additionally this method shows good commercial and technical implementation potential.
- PostInfluence of excessive water on wastewater treatment performance - An analysis using key performance indicators(2015) Molander, Camilla; Chalmers tekniska högskola / Institutionen för bygg- och miljöteknik; Chalmers University of Technology / Department of Civil and Environmental Engineering
- PostSeasonal Low Temperature Borehole Thermal Energy Storage - Utilizing excess heat for district heating in Gothenburg.(2015) Siiskonen, Maria; Chalmers tekniska högskola / Institutionen för bygg- och miljöteknik; Chalmers University of Technology / Department of Civil and Environmental EngineeringOccasionally during summer the heat load in the district heating (DH) network of the Gothenburg region exceeds the heat demand of the customer, i.e. there is an excess of heat in the DH-network. Nowadays, this excess heat is cooled against a river or in a cooling tower at a waste incineration plant. The aim of this study is to store this excess heat in the ground instead of cooling it against a river and use this excess heat during occasions when the heating demand is higher, during winter. This excess heat will be stored in a borehole thermal energy storage (BTES). The studied BTES will be connected to existing heat pumps at Ryaverket owned by Göteborg Energi AB. The conditions, regarding temperature and volumetric ow rate, of the heat source of the heat pumps, treated sewage water, will be improved with the aid of a BTES. When these previously mentioned conditions of the sewage water are improved more heat can be generated by the heat pumps. An increased heat generation by the heat pumps will replace heat generated by other, more expensive, heat generation units. To evaluate the economic profitability of such a system the net present value has been calculated. Designs for BTES, storing 50GWh and 25GWh of waste heat, are found with the aid of a software named GLHEpro and the investment cost for these designs are calculated. To reach economic profitability for this project the savings made by this new system,when heat generated by the heat pumps is increased, should meet the extent of the investment cost. To be able to calculate the savings, a software named Martes is used. The investment cost of a BTES is ten times larger than the savings ever will be in the most probable scenario regarding the investment cost of a BTES. Economic profitability is only reached if the investment cost of the BTES is in the minimum price range, if subsidies to cover 40% of the investment cost from Horizon2020 is gained, if an interest rate of 5% is used for economic calculations and when the availability of the heat pumps is increased by 15%. Economic profitability can also be gained for a scenario when the prices for the investment cost are in the minimum price range and an interest rate of 0% is used for economic calculations. It seems rather unlikely to gain all these privileges for this case study to become economically profitable.
- PostSeasonal Storage of Distant Industrial Excess Heat for District Heating(2015) Friberg, Ida; Chalmers tekniska högskola / Institutionen för bygg- och miljöteknik; Chalmers University of Technology / Department of Civil and Environmental EngineeringLarge parts of district heating used in Gothenburg originates from excess heat generated from industries near the city. There is potential to utilise more excess heat in Gothenburg from distant industries. This will however require a connecting pipeline of considerable length with high investment cost. This thesis investigates whether the economical benefits of such a pipeline can be increased by installing an additional borehole thermal energy storage (BTES) and an electricity driven heat pump. Investigations have been made for two locations, western Gothenburg and Kung alv. The behaviour of the BTES has been analysed with the Duct Storage Model using the software PILESIM 2. The district heating system has been simulated with the software Martes. Simulation data including prices of fuels, taxes and political instruments used for this study are based on the forecasts of the local district heating company, G oteborg Energi AB. The investment cost of the BTES is based on previously performed master thesis project at Göteborg Energi AB. The results indicate that the potential to make profits from the proposed BTES and the heat pump system under the prescribed project restrictions is rather poor, especially for Kungälv. Western Gothenburg qualifies as an better location from an economical point of view. The COP of the heat pump and electricity price have large impact on the economical results. The choice of interest rate also has a large in uence on the economical feasibility of the project.